Investor sentiment and bidder annoucement abnormal returns

Investor sentiment and bidder announcement abnormal returns

Jo Danbolt a ,Antonios Siganos b ,Evangelos Vagenas-Nanos b,?

a University of Edinburgh,29Buccleuch Place,Edinburgh EH89JS,UK b

University of Glasgow,University Avenue,Glasgow G128QQ,UK

a r t i c l e i n f o a

b s t r a

c t

Article history:

Received 18December 2013

Received in revised form 15June 2015Accepted 18June 2015

Available online 25June 2015We introduce the signi ?cance of a direct sentiment proxy as an explanatory variable of bidder announcement returns.We argue that sentiment subconsciously in ?uences investor perception of potential merger synergies and risks,and therefore relates to bidder abnormal returns.We proxy daily sentiment based on Facebook status updates across seventeen international markets and show that there is a positive relation between sentiment and bidder announcement returns.In line with behavioral literature stating that sentiment more heavily in ?uences uninformed traders,this relation is more pronounced in acquisitions with a low percentage of blockholder ownership,acquisitions of US public targets,and acquisitions of large targets relative to the size of the bidders.Our study goes beyond the conventional sentiment and stock market returns liter-ature,uncovering a signi ?cant relation between sentiment and ?rm-speci ?c abnormal returns to acquiring companies.

?2015Elsevier B.V.All rights reserved.

JEL classi ?cation:G1G34

Keywords:Mergers

Bidder announcement returns Behavioral ?nance Investor sentiment

1.Introduction

There is extensive literature (e.g.,Eckbo,2009)discussing the relation of acquirer-and deal-speci ?c characteristics with acquirers'announcement returns.If investors are rational,in line with the expectations of the ef ?cient markets hypothesis (Fama,1970),the share price reaction of the acquiring ?rm on the announcement date of an acquisition should re ?ect the expected net present value of the acquisition (i.e.,the discounted target ?rm value plus the value of potential synergies minus the amount paid to the target company's shareholders).This paper relaxes the assumption of strict investor rationality and argues that a behavioral aspect is related with bidders'short-term wealth effects.Investor sentiment is expected to in ?uence investor perception of potential synergies and risks involved in the acquisition,leading to an irrational component of the share price reaction.Such misvaluations are expected to be of a short-term nature and to be arbitraged away over the days following the bid announcement (Of ?cer,2007).

A number of psychological studies have shown that sentiment has an impact on judgment.Mitchell and Phillips (2007)report that even small changes in sentiment may have an impact on neural activation and cognition,such as on participants'ability to plan,mem-orize,and think creatively.Investors who are in a good mood tend to make more optimistic decisions (Bless et al.,1996;Wright and Bower,1992).A number of studies in the ?eld of ?nance have indeed empirically validated the positive relation of sentiment with stock market returns.For example,Edmans et al.(2007)?nd that sports results are related with contemporaneous stock market in-dexes,in that a country's win/loss in sports is related with a positive/negative corresponding stock market reaction.Palomino et al.(2009)report that share prices of winning British soccer clubs overreact to information.Hirshleifer and Shumway (2003)show that abnormal weather conditions are positively related with contemporaneous stock market returns.Kaplanski and Levy (2010)

Journal of Corporate Finance 33(2015)164–179

?Corresponding author at:Adam Smith Business School,Accounting and Finance Division,University of Glasgow,West Quadrangle,Main Building,University Av-enue,Glasgow G128QQ,Scotland,UK.Tel.:+441413307677;fax:+441413304442.

E-mail addresses:Jo.Danbolt@https://www.sodocs.net/doc/9515517876.html, (J.Danbolt),antonios.siganos@https://www.sodocs.net/doc/9515517876.html, (A.Siganos),evangelos.vagenas-nanos@https://www.sodocs.net/doc/9515517876.html, (E.

Vagenas-Nanos).

https://www.sodocs.net/doc/9515517876.html,/10.1016/j.jcorp ?n.2015.06.0030929-1199/?2015Elsevier B.V.All rights

reserved.

Contents lists available at ScienceDirect

Journal of Corporate Finance

j o ur n a l h o m e p a g e :w ww.e l s e v i e r.c om /l o c a t e /j c o r p f i n

report that aviation disasters negatively in ?uence people's sentiment,and negative stock market returns are experienced shortly after,even for companies not affected by the event.The positive relation between sentiment and stock returns has also been support-ed by a number of studies (e.g.,Lemmon and Portniaguina,2006)that use direct monthly sentiment proxies through surveys,such as the University of Michigan Consumer Sentiment Index.According to Johnson and Tversky (1983)and Loewenstein et al.(2001),sen-timent in ?uences not only the judgment of favorable future prospects,but also the assessment of risk.Kaplanski et al.(forthcoming)survey investors and ?nd that happy investors not only are positive on expected stock returns,but also believe that the risks involved are relatively low.

We hypothesize that for mergers announced on days with optimistic market sentiment,investors are subconsciously more likely to overestimate potential synergies and underestimate the risks associated with the merger.On counterpart merger announcement days with low investor sentiment,investors would subconsciously be pessimistic regarding expected synergy bene ?ts and perceive the potential risks of the acquisition to be high.We therefore hypothesize that sentiment is positively related to bidder announcement returns.We believe this study is the ?rst to explore the relation of a direct sentiment proxy with bidder announcement abnormal returns.Note that while prior studies ?nd the overall stock market index to be positively correlated with market sentiment,we explore the relation between market sentiment and the market's reaction to ?rm-speci ?c bid announcements.This study thus goes beyond the conventional relation between sentiment and stock returns,and we explore bidder abnormal stock returns,in excess of the corresponding stock market returns.Uncovering a signi ?cant relation between sentiment and the stock market reaction to acqui-sition announcements,this study provides new insights into the relation between sentiment and share returns.Our ?ndings suggest behavioral aspects are related to investors'perceptions of risk and synergies of mergers and acquisitions.

It may be argued that the shares of merging ?rms are heavily traded by professional investors,and therefore that any irrational component to the share price reaction upon bid announcement is unlikely.However,there is evidence to suggest professional inves-tors may also be liable to be in ?uenced by sentiment,with e.g.,Kaplanski and Levy (2013)reporting that US analyst recommendations are in ?uenced by sentiment,and Kling and Gao (2008)showing that stock returns and contemporaneous Chinese institutional inves-tor sentiment are positively related.1Professional investors are,though,in ?uenced by sentiment to a lesser extent than uninformed traders (e.g.,Lemmon and Portniaguina,2006).We therefore expect any relation between sentiment and bidder abnormal returns to be short-lived,and for there to be signs of a reversal of any effect of sentiment on share returns over the days following the bid an-nouncement,as any pricing anomaly is exploited by merger arbitrageurs.

In the main analysis,we use the Gross National Happiness Index (GNH)from Facebook to capture sentiment on the days around merger announcements.The GNH index offers signi ?cant advantages over conventional sentiment indexes.23First,Facebook data is available with a daily frequency,which enables us to explore sentiment during merger announcements,while conventional sentiment indexes are available on a monthly basis.4Second,the GNH index is available for seventeen international markets,including the US market,giving an international dimension to the validity of our results.Third,while traditional sentiment surveys tend to be based on relatively small samples of hundreds or,at most,a few thousand respondents,the Facebook GNH index is based on several million daily status updates.By 2014,there were almost 1.3billion active Facebook users worldwide (Kuchler,2014).The index can thus be argued to capture the overall sentiment of a large proportion of a country's population.

We acknowledge that there may be certain limitations of the Facebook GNH index for our research purposes.Facebook users may have been young when Facebook was ?rst introduced in 2004,and few are likely to have been investors.However,in later years there has been a signi ?cant increase in the age pro ?le of users.Kramer and Chung (2011)use a sample period between September 2007and February 2010and ?nd that over a quarter of Facebook users are older than 45,and less than ten percent are teenagers.Recent research (Kramer et al.,2014,p.8788),also using Facebook data,?nds “…emotional states can be transferred to others via emotional contagion,leading people to experience the same emotions without their aware-ness ”.Thus,even if a relatively small proportion of Facebook users are investors,it is possible that investors'sentiment is in-?uenced by that of people around them,which arguably may be captured by Facebook,given its very widespread use.Indeed,Karabulut (2013)and Siganos et al.(2014)validate the relevance of the Facebook sentiment index to capital markets by show-ing that it is positively related with contemporaneous stock market returns.Their ?ndings are consistent with evidence from conventional monthly sentiment proxies.There is,thus,prior evidence of sentiment,as proxied by Facebook's GNH index,in ?uencing share prices.

Our study is the ?rst to use Facebook's sentiment data within the mergers and acquisitions ?eld,looking at the relation between sentiment and bidder abnormal returns.However,as a robustness test,we also use the Gallup Economic Con ?dence Index as a proxy of market sentiment.While also available on a daily basis,the Gallup Index is,however,only available for the US and for a slightly shorter time period than the GNH Index.Analysis of the US sub-sample using the Gallup Index produces similar results to those obtained using Facebook's GNH,suggesting our results are not driven by the choice of sentiment proxy.However,given the larger sample of countries and the longer period of data availability,we base our main analysis on the Facebook GNH index data.

1

There is evidence even beyond the ?nance ?eld that professionals are in ?uenced by non-rational factors.For example,Glejser and Heyndels (2001)report that ex-pert judges in the Queen Elisabeth International Music Competition tend to award higher marks to musicians that perform later in the competition.2

See Siganos et al.(2014)for further details on the merit of GNH as a market sentiment index.3

Other commonly used sentiment indexes include the University of Michigan Consumer Sentiment Index and the Consumer Con ?dence Index.4

Note that the Gallup Economic Con ?dence Index offers daily US sentiment data.However,Gallup's coverage is shorter in length than that of the GNH,and its cov-erage is limited to the US market.For robustness,we explore US results with Gallup later in the study.

165

J.Danbolt et al./Journal of Corporate Finance 33(2015)164–179

166J.Danbolt et al./Journal of Corporate Finance33(2015)164–179

We use GNH data between September2007and March2012and empirically support that GNH is related with bidder announce-ment returns.5The average cumulative abnormal returns within a four-day period from the merger announcement day to three days after(0,+3)are2.06(0.92)percent in the highest(lowest)GNH quartile.The difference in returns between the high and low GNH portfolios is economically large and statistically signi?cant at the one percent level.Results hold when controlling for a number of variables that have previously been found to be related with bidder returns.We estimate bidder abnormal stock returns,and therefore our results indicate a relation that goes beyond the typical sentiment and stock market returns(e.g.,Lemmon and Portniaguina,2006). In a further robustness test,we?nd that the relation between sentiment and bidder stock returns is more pronounced during the merger announcement period than during a random period prior to the merger announcement(such as over the period from day ?12to?10relative to the day of the bid announcement),offering further credence to the suggestion that market sentiment seems to in?uence the stock market reaction to merger announcements.

In line with our hypothesis,sentiment seems to in?uence investor perception of potential synergies and/or the risk involved in the deal.On days with positive sentiment,investors would appear to be more likely to overestimate potential synergies and underesti-mate the risks associated with the merger,with the reverse being likely on days with negative sentiment.We further?nd evidence of the positive relation between GNH and bidder announcement abnormal returns to at least partially reverse over the days following the merger announcements,giving further support to the argument that the reaction to the announcement was likely an irrational short-term overreaction to information.

We further explore sub-samples for which sentiment is expected to have a more or less pronounced effect on bidder returns based on prior literature?nding that sentiment more heavily in?uences less informed investors(e.g.,Lemmon and Portniaguina,2006).Po-tential validation would offer further credence to the argument that sentiment is the driver behind the key relation reported in the study.We explore the relation between bidder returns and GNH in acquisitions by bidders with different levels of blockholder own-ership,in acquisitions of public versus private target?rms,and in acquisitions with different levels of relative target size.In particular, we hypothesize that the relation between GNH and bidder returns is more pronounced within?rms with low levels of blockholder ownership,since small investors have been found to be more heavily in?uenced by sentiment(e.g.,DeLong et al.,1990).We also hy-pothesize that the relation is more pronounced within acquisitions of public rather than private target?rms.Public acquisitions are typically larger transactions and tend to attract more media attention(e.g.,Fang and Peress,2009),and small investors are heavily in?uenced by media coverage when selecting?rms in which to invest(Barber and Odean,2008).Finally,we hypothesize that the re-lation is stronger if the size of the target is large relative to the size of the bidder.Not only are acquisitions of large targets likely to attract more media attention,but any behavioral biases in valuing targets can be expected to have a larger impact on bidder returns where the target is relatively large.We empirically support the above hypotheses.

This study contributes to the literature in several ways.We?rst contribute to the behavioral?nance literature.While behavioral?nance studies(e.g.,Edmans et al.,2007;Hirshleifer and Shumway,2003;Siganos et al.,2014)tend to show that sentiment is positively related with aggregate stock market performance,we study the relation between sentiment and individual?rms'returns,?nding sentiment to have a signi?cant relation with bidder abnormal returns during their merger an-nouncements.Our results highlight a relation beyond the typical sentiment and stock market returns relation reported in pre-vious studies,indicating the in?uence of sentiment on investors'perception of synergies and risks associated with mergers and acquisitions.We also develop predictions,based on behavioral literature,as to which takeover transactions are likely to be more affected by sentiment than others,and empirically test these predictions.Focusing on the merger context,we show for the?rst time that sentiment has a stronger relation with bidder returns for bidders with a low percentage of blockholder own-ership,in acquisitions of large targets relative to the size of the bidders,and,for the US sub-sample,in acquisitions of public targets.We further contribute to the merger literature by empirically validating for the?rst time the relation of a direct inves-tor sentiment proxy on bidder announcement abnormal returns.

Our study is most closely related with Rosen(2006),who reports that US bidder announcement returns are more likely to increase in‘hot’merger markets,as de?ned by recent mergers with good announcement performance and periods with good overall stock market performance.Both Rosen's study and ours?nd that behavioral aspects are related with bidder announce-ment returns.Rosen's(2006)explanation is that there is momentum in investor perception of potential synergies from mergers,implying that the level of optimism in a market is related with bidder announcement performance.He?nds a short-run overreaction for deals announced during hot merger periods,and a long-run price correction,and attributes this to investor sentiment.Our study instead uses a direct daily proxy of sentiment across international markets to highlight the importance of sentiment during merger announcements on contemporaneous bidder announcement abnormal returns.The study is also related to extensions of the neoclassical theory,according to which behavioral aspects impact?rm managers'de-cisions on the timing of mergers and the selected method of payment(e.g.,Bouwman et al.,2009;Rhodes-Kropf and Viswanathan,2004;Rhodes-Kropf et al.,2005;Shleifer and Vishny,2003).We highlight the signi?cance of investor,rather than manager,sentiment on merger share price reactions.

The remainder of the paper is structured as follows:Section2describes our data.Section3discusses the empirical results on the relation between sentiment and the short-term wealth effect of bidders upon their merger announcements.Section4 concludes.

5In untabulated results,we empirically?nd that there is no relation between sentiment and target announcement returns.Targets experience little,if any,uncer-tainty relating to their announcement returns,since the majority experience signi?cant gains(e.g.,King,2009)and the uncertainty regarding the value of the invest-ment falls largely on the bidder.

2.Data description

We use daily GNH data from Facebook for seventeen international markets between September 2007and March 2012as our main proxy of market sentiment.The countries included are Argentina,Australia,Austria,Belgium,Canada,Germany,India,Ireland,Italy,Mexico,the Netherlands,New Zealand,Singapore,South Africa,Spain,the UK and the US.6The coverage available from Facebook de-termines the countries selected and the sample period of the study.GNH is estimated by Facebook's Data Team based on the status updates of millions of Facebook users,and the construction of the index is explained in detail in Kramer (2010).GNH is a standardized index estimated by Facebook's Data Team by measuring the percentage of ‘positive ’and ‘negative ’terms used in Facebook users'status https://www.sodocs.net/doc/9515517876.html,ing Text Analysis and Word Count (TAWC)programs to identify positive and negative words from the Linguistic Inquiry and Word Count (LIWC)dictionary,GNH is estimated as follows:

GNH i ;j ?

x p ;i ?x p ;all σp ;all ?

x n ;i ?x n ;all

σn ;all

e1T

where GNH i ,j is the sentiment index of country j at day i ,x p ,i and x n ,i are the average positive (p )and negative (n )words used respec-tively on day i in the country,and x p ,all ,x n ,all ,σp ,all ,and σn ,all are the average (x )positive and negative words used over the duration of

the index and the standard deviation (σ)of those variables.The extreme high and low 10%of the days are excluded by Facebook when estimating x p ,all ,x n ,all σp ,all ,and σn ,all to minimize the impact of extreme values.In line with Siganos et al.(2014),we exclude observa-tions above the 99th percentile,since these normally relate to messages like “Happy Mother's Day ”,which do not necessarily re ?ect sentiment.

We also download from Thomson OneBanker information on acquisitions by bidding ?rms in corresponding countries within the available data periods.For a deal to be included in the sample,the bidder needs to be listed and to acquire at least 50%of the target's shares.We also require the target company size (deal value)to be at least 1%of the market value of the bidder.These data restrictions are commonly used to identify signi ?cant acquisitions in the merger literature (e.g.,Moeller et al.,2004).Eligible ?rms also have avail-able Datastream codes and available returns from Datastream for the interval period from the merger announcement to three days after the day of their bid announcements.At least one of those daily stock returns should be non-zero for a bidding ?rm to be included in the sample.We use the returns index (RI)datatype from Datastream to incorporate dividend payments to calculate log returns,and we proxy market returns for each of the seventeen countries by Datastream's total market indexes (TOTMK).

Following prior literature,such as Fuller et al.(2002)and Rosen (2006),we calculate abnormal returns as the difference between the return for the bidder and the relevant country index return.To measure the short-term wealth effect,we estimate the cumulative abnormal returns over a four-day period (0,+3).Since small investors are likely more prone to be in ?uenced by sentiment,and it is unlikely that small investors are aware of potential leaks prior to merger announcements,our sentiment and stock returns measures commence at the day of the merger announcement (day 0).We use a three-day lead to fully capture the share price reaction by in-vestors,since small investors may be slow to react to information,and to allow for Facebook users updating their status at any time during the day,even after the closure of the stock markets.7In untabulated results,we ?nd that results are similar and the con-clusions consistent when using alternative periods,such as in the shorter three-day event window (0,+2).

While our focus is on the relation between sentiment and bidder abnormal returns,prior research ?nds that ?rm and deal char-acteristics have a signi ?cant relation with bidder abnormal returns.Based on the literature,8we therefore also incorporate a number of control variables in the analysis.Prior research suggests that the listing status of targets may affect bidder abnormal returns,and,following Fuller et al.(2002)and Rosen (2006),we classify deals into acquisitions of Public,Private,and Subsidiary ?rms.Public is a dummy equal to one for public target deals and Private a dummy equal to one for private deals (with Subsidiaries captured by the intercept in the regression analysis).Stock is a dummy equal to one for deals with full payment in stock and Cash a dummy equal to one for deals with full cash offers (with Mixed Pay offers captured by the intercept).Larger transactions are likely to have a larger impact on the bidder,and we therefore control for the relative size of the target to the bidder.We incorporate a Relative Size dummy which is equal to one for deals belonging to the top quartile of relative size between bidder and target ?rms,and zero otherwise.

Other bid characteristics controlled for are the size of the bidder (as captured by the natural logarithm of the market value of eq-uity,LnMV);the bidder's book-to-market-ratio (BTMV);domestic versus cross-border acquisitions (with Domestic a dummy variable taking the value of one for domestic deals);whether the acquisition is focused or diversifying (with diversifying being a dummy var-iable equal to one where targets and bidders do not share the same ?rst two-digit SIC code);whether the transaction is competitive or whether there is a single bidder for the target (with Competitive being a dummy equal to one for multiple bidders according to SDC);and for tender offers versus mergers (with Tender being a dummy equal to one for tender offers).Following e.g.,Faccio and Masulis (2005)and Karampatsas et al.(2014),we use the pre-bid run-up in the bidder's market-adjusted returns to capture possible market overvaluation of the bidder.CARs ?252,?20is the cumulative abnormal returns over the period from ?252to ?20days prior to each merger announcement.As ?nancial strength and capital structure may affect the method of payment used (Karampatsas et al.,2014),

6

Note that Facebook offers sentiment data for twenty markets.Chile,Colombia and Venezuela are excluded since no mergers are available within the requested data restrictions.7

Vitrue (2010)reports that Facebook activity peaks at 3pm,and is present after the closure of stock markets.8

Studies include those by Asquith et al.(1983),Travlos (1987),Rau and Vermaelen (1998),Sudarsanam and Mahate (2003),Faccio and Masulis (2005),Titman et al.(2004),Draper and Paudyal,(2006),and Danbolt and MacIver (2012).

167

J.Danbolt et al./Journal of Corporate Finance 33(2015)164–179

168J.Danbolt et al./Journal of Corporate Finance33(2015)164–179

Table1

Descriptive statistics.

This table shows the descriptive statistics of the number of mergers,the sentiment level(GNH),and the percentage cumulative abnormal returns(CARs)per country in the sample.Sentiment and cumulative returns are estimated over the four-day period from the merger announcement day to three days after(0,+3).N indicates the number of merger transactions analyzed.*,**,and***indicate signi?cance at the10,5,and1%levels,respectively.

CARs(0,+3)CARs(0,+3)Public Private

GNH(0,+3)N p-Value Average p-Value Median CARs(0,+3)N p-Value CARs(0,+3)N p-Value

All?0.013***75290.0000.017***0.0000.007?0.007**10590.0290.020***38520.000 Argentina?0.007140.4320.0110.6140.027?0.00430.970?0.00460.890 Australia?0.009***7330.0000.033***0.0000.0130.0001020.9710.042***3970.000 Austria?0.014***310.0000.0050.585?0.0020.00430.9350.002140.813 Belgium?0.005*700.0550.015***0.0060.0100.01160.7410.016**340.032 Canada?0.012***12990.0000.023***0.0000.005?0.0102830.1490.033***6060.000 Germany?0.003*1190.0880.0090.1180.012?0.007200.5770.004480.705 India?0.058***230.0000.0200.2110.0130.03420.5520.016140.487 Ireland-Rep?0.025***620.0000.0150.2310.019?0.04120.5780.010330.493 Italy0.014***1270.0000.0030.4510.002?0.029**110.0280.003530.725 Mexico?0.006160.2570.0170.2380.0160.01850.571?0.00250.899 Netherlands?0.016***910.0000.0020.783?0.003?0.026190.1570.001360.892 New Zealand?0.013***280.0000.0220.2660.000?0.02730.5560.048130.139 Singapore?0.009***1200.0000.0120.1690.0030.03260.3950.023480.136 South Africa?0.016***490.0000.028***0.0080.0060.071*50.0840.029240.100 Spain?0.008*680.050?0.0040.455?0.004?0.026100.110?0.009250.424

UK?0.014***11520.0000.016***0.0000.010?0.0031010.7530.016***6950.000

US?0.016***35250.0000.013***0.0000.007?0.008*4770.0910.014***18010.000 we incorporate DebtTA,which is long-term debt plus current liabilities to total assets,and CashFlow,which is measured as operating income before depreciation,interest expenses,taxes,and dividends to total assets.

Table1shows summary descriptive statistics of sentiment and the share price reaction of bidders around their merger announce-ments.We?nd that close to half of the acquisitions took place in the US(3,525out of a total of7,529acquisitions in our sample).Due to the small number of acquisitions available in some countries,we present empirical results for all countries combined and,in a later section,for US and non-US acquisitions separately.In line with prior literature(e.g.,Chang,1998;Draper and Paudyal,2006;Travlos, 1987),we?nd that the short-term wealth effect tends to be positive for bidders in acquisitions of private?rms and negative in acqui-sitions of publicly listed targets.For example,the four-day cumulative abnormal returns are?0.7and2.0%for the sample as a whole for public and private target acquisitions,respectively.We also estimate the mean GNH for the equivalent interval period from the merger announcement day to three days after.With the exclusion of extreme positive days(such as“Happy Mother's Day”),mean GNH tends to be negative,although there are some national variations,with India experiencing the lowest average GNH(?0.058) and Italy the highest(0.014)around the time of the acquisition announcements.9Our descriptive statistics for GNH are similar to those reported by Siganos et al.(2014).In the cross-sectional regressions,standard errors are clustered by country(Petersen, 2009),and?xed effects by country are also included to control for such variations.

Table2offers Pearson correlations of the variables used in the study.The correlation coef?cient between the GNH variable and ab-normal returns is positive and statistically signi?cant at the5%level,offering the?rst indication of sentiment having a signi?cant re-lation with bidder abnormal returns.In line with the literature(e.g.,Sudarsanam and Mahate,2003),abnormal returns are also related with the control variables used,and some of the control variables are correlated.There is,however,no issue of collinearity(as the highest correlation coef?cient is less than0.48),and the signi?cant correlations among the control variables are acceptable for the purpose of the study,since we are not focusing on the relation of each control variable with abnormal returns,but rather on whether GNH is related to bidder announcement returns after controlling for potential variables that are related with companies'stock returns. The following section explores whether GNH is related with bidder announcement returns.

3.Empirical results

3.1.Sentiment and bidder announcement returns:univariate results

We?rst undertake univariate analysis to explore the relation between GNH and bidder announcement returns.Note that GNH and returns are measured over the same interval period between day0and+3after each merger announcement day.We?rst rank mergers based on the level of GNH over the event window and then split the sample of acquisitions into quartiles.Quartiles,rather than e.g.deciles,are used to ensure that portfolio returns do not arrive from a small number of observations.

Table3shows the cumulative abnormal portfolio returns around the merger announcements across different levels of GNH port-folios.We?nd that GNH is signi?cantly related to bidder stock returns.For example,bidder abnormal returns are2.06and0.92%for

9It should be noted that the GNH is on average similar on bid and on non-bid dates,and in probit analysis of the relation between bid announcement and either cur-rent or past levels of GNH,we?nd no indication of the timing of bid announcements being related to the level of GNH.Given the time and effort involved in planning and executing takeover bids,it is unlikely that managers would time the announcements based on small variations in market sentiment.

170J.Danbolt et al./Journal of Corporate Finance33(2015)164–179

Table3

GNH and CARs—univariate results.

This table shows the univariate results regarding the relation of

sentiment(GNH)with cumulative returns of bidders estimated

over the four-day period from the merger announcement date to

three days after(0,+3).We?rst rank mergers on sentiment level

and then generate quartile portfolios.High(low)sentiment is the

top(bottom)quartile.N indicates the number of mergers available.

p-Values are shown in parentheses.Results shown are for the full

sample of seventeen countries.**and***indicate signi?cance at

the5and1%levels,respectively.

CARs(0,+3)

High GNH(0,+3) 2.06***

(0.000)

N1882

2GNH(0,+3) 1.78***

(0.000)

N1880

3GNH(0,+3) 2.01***

(0.000)

N1879

Low GNH(0,+3)0.92***

(0.000)

N1882

High–low 1.15***

(0.001)

high and low GNH portfolios,respectively,when analyzing the full sample of countries.The difference is economically large and statistically signi?cant at the1%level.Moving from high to lower GNH portfolios,mean returns for bidders for the overall sample of all countries are as follows:2.06%,1.78%,2.01%,and0.92%.These results offer initial support for our main hypothesis that sentiment is related with bidder returns,with acquisitions undertaken on days with high market sentiment associated with higher announce-ment abnormal returns.

3.2.Sentiment and bidder announcement returns:multivariate results

Prior research on mergers and acquisitions highlights the impact of bid and?rm characteristics on bidder returns,and we therefore undertake multivariate analysis to test whether the relation between sentiment and bidder CAR holds once we control for variables that may impact on bidder abnormal returns.We estimate OLS regressions with robust standard errors clustered by country,and country-?xed effects are included.The dependent variable is the four-day cumulative abnormal returns per?rm(0,+3).The key in-dependent variable is GNH in the contemporaneous period with that used for abnormal returns,and the following control variables are also employed:the logarithmic market cap of the bidder,public and private acquisition dummy variables(with subsidiaries cap-tured by the intercept),stock and cash payment dummies(with mixed payment captured by the intercept),a relative size dummy for deals in the top quartile,book-to-market ratio,a domestic acquisition dummy,a diversi?ed dummy based on whether the bidder and target?rms do not share the same two-digit SIC code industries,a competitive bid dummy if there are multiple bidders,a tender offer dummy,the cumulative run-up returns prior to merger announcements(CARs?252,?20),the ratio of debt to total assets,and cash?ows.We include eight one-day lags(for days?8to?1)of GNH to ensure that prior sentiment levels could not be used to pre-dict the next period's sentiment,and,similarly,eight-day lags of each country's stock market returns to control for potential reverse causality,with prior gains/losses in stock markets in?uencing investors'happiness.Eight lags are selected,since in untabulated results we?nd that there is statistically signi?cant daily autocorrelation for GNH up to a maximum of eight lags,and the same selection of lags are used for prior stock market returns,for consistency.10The parameter coef?cients of country dummies,and those on lags of GNH and on lags of stock market returns,are not reported for space considerations.

Table4shows the results of the multivariate analysis.We?nd that sentiment remains positively related with bidder returns.Col-umn(1)shows that the parameter coef?cient on GNH is0.120,with a p-value equal to0.003,indicating that after controlling for other factors,a one percentage point increase in GNH is associated with a0.120percentage point increase in bidder cumulative abnormal returns.Note that bidder stock returns are in excess of the contemporaneous stock market returns,indicating that the relation report-ed in this study is beyond the stock market returns and sentiment relation previously reported in the literature.In untabulated results, we?nd that the parameter coef?cient for GNH is0.147and0.267when regressing GNH with stock market returns and bidder returns, 10In untabulated results,we also use?ve-day lags for both GNH and stock market returns to capture potential weekly cycles.Results remain very similar in alternative lag selections.

respectively (both signi ?cant at the 1%level).Note that the difference between 0.267and 0.147is the bidder stock returns in excess of stock market returns reported earlier (0.120).The relation between bidder stock returns and sentiment is therefore much more prom-inent at the time of their bid announcement than the general relation between sentiment and stock returns reported in conventional behavioral studies.Our results are consistent with what we would expect if investors'subconscious reaction to potential synergies and risks involved with mergers is associated with sentiment,with happy investors tending to overestimate potential synergies and/or underestimate the risks involved with the mergers.

As a further test of whether the relation between sentiment and stock returns is particularly strong during acquisitions,when the value of bidders is arguably more uncertain than usual,we use the same model to test the relation between sentiment and share returns in a period prior to the bid announcement,when the forthcoming bid is still not known to investors.Column (2)of Table 4shows the parameter coef ?cients when regressing bidder abnormal stock returns during the interval period between ?12and ?10days prior to each merger announcement on contemporaneous GNH and the same control variables.We ?nd that the parameter coef ?cient for GNH for the ?12and ?10interval period is insigni ?cant,highlighting the existence of the relation only during the merger announcement period.A Chow test (Chow,1960)that compares the parameter coef ?cient for GNH between the pre-bid

Table 4

GNH and CARs —multivariate results.

Column (1)of this table explores whether the relation between sentiment and bidder returns holds after adjusting for a number of control variables,and column (2)shows the extent to which the relation is present prior to the merger announcement period.The dependent variable in column (1)is the percentage cumulative abnormal returns estimated from the merger announcement day to three days after (0,+3),while in column (2)it is from ?12days to ?10prior to the merger announcement.The main independent variable under consideration is sentiment (GNH),which is estimated in the interval period between 0and +3days after merger announcements in column (1),and ?12and ?10days prior to merger announcements in column (2).Column (3)shows the Chow test result on the statistically signi ?cant difference between columns (1)and (2).Explanatory variables are as de ?ned in Table 2.Standard errors are clustered by country.Country dummies,and eight lags on sentiment and on stock market returns,are included.p-Values are shown in parentheses.N indicates the number of observations.Results shown are for the full sample of seventeen countries.*,**,and ***indicate signi ?cance at the 10,5,and 1%levels,respectively.

(1)

(2)

(3)CARs (0,+3)

CARs (?12,?10)

Diff

GNH (0,+3)0.120***(0.003)

GNH (?12,?10)0.027(0.200)

Difference GNH 0.093***(0.008)

LnMV ?0.015***0.001(0.000)(0.793)Public ?0.034***0.004*(0.000)(0.068)Private ?0.010***0.001(0.000)(0.650)Stock 0.008*0.010**(0.083)(0.024)Cash 0.0020.000(0.375)(0.887)RelSize 0.002*?0.002(0.092)(0.212)BTMV 0.0010.001**(0.526)(0.041)Domestic ?0.0090.001(0.124)(0.799)Diversi ?ed ?0.001?0.003**(0.559)(0.047)Competitive 0.025*?0.003(0.074)(0.359)Tender 0.013**?0.002(0.022)(0.542)CARs ?252,?20?0.005**?0.001(0.040)(0.874)DebtTA 0.002***?0.004***(0.000)(0.000)CashFlow 0.001***?0.001***(0.000)(0.001)Constant

0.079***?0.013***(0.000)(0.006)Country dummies Yes Yes Lagged sentiment

Yes Yes Lagged market returns Yes Yes N

64936378Adj.R-sq

0.070

0.029

171

J.Danbolt et al./Journal of Corporate Finance 33(2015)164–179

172J.Danbolt et al./Journal of Corporate Finance33(2015)164–179

Table5

The relation of sentiment with lead bidder announce-

ment returns.

This table explores within a multivariate analysis the re-

lation of sentiment with bidder cumulative abnormal

returns after merger announcements(0,+3)as well as

from day+4to day+12after merger announcements.

The dependent variable is the percentage cumulative

returns(CARs).We also incorporate the control vari-

ables,in line with the prior multivariate table(Table4),

but due to space considerations only the parameter

coef?cient of sentiment(GNH)is reported.Country

dummies,and eight lags on sentiment and on stock

market returns,are included.p-Values are shown in

parentheses.Results shown are for the full sample of

seventeen countries.*and***indicate signi?cance at

the10and1%levels,respectively.

Days CARs(0,+3)

(0,+3)0.120***

(0.003)

+4?0.072***

(0.000)

+5?0.000

(0.990)

+6?0.002

(0.917)

+70.035

(0.267)

+8?0.012

(0.520)

+90.009

(0.560)

+100.027

(0.215)

+110.018

(0.193)

+12?0.032*

(0.062)

and merger announcement periods,reported in Column(3)of Table4,shows that the coef?cient for GNH is signi?cantly higher at the 1%level in the merger period.

Note that the signs of the parameter coef?cients for control variables are generally in line with prior literature(e.g.,Draper and Paudyal,2006;Travlos,1987).We?nd bidder abnormal returns to be higher in acquisitions of subsidiaries than in acquisitions of pri-vate targets,with bidder abnormal returns particularly low in acquisitions of publicly listed targets.With the mix of public and private targets in the sample,it is not unexpected that we?nd bidder abnormal returns on average slightly higher in share than in cash?-nanced acquisitions.Consistent with prior literature,we?nd bidder returns to be higher in tender offers than in mergers,but,contrary to expectations,also higher in competitive bidding contests.11We?nd some evidence of reversal,with bidder abnormal returns being signi?cantly lower where there has been a substantial run-up in the bidder's share price prior to the bid.Bidder returns are also in-?uenced by gearing levels and cash?ow balances.

3.3.Is the relation between sentiment and bidder returns irrational?

We next explore whether the relation between sentiment and bidder returns is the result of a short-term market overreaction.To test this,we explore the relation between sentiment and bidder announcement abnormal returns over the days following a merger announcement.If the relation between sentiment and bidder announcement returns is driven by an irrational reaction,the relation is expected to reverse as traders less susceptible to sentiment(such as merger arbitrageurs)take advantage of the market mispricing.

Table5shows the parameter coef?cients of GNH when we estimate the relation between GNH,as estimated previously in the in-terval period between0and+3days,and its relation with bidder returns over the following+4to+12days after each merger an-nouncement.Due to space considerations,we only report the parameter coef?cients for GNH on each day,although all control variables used earlier are included in the regressions.We?nd that the relation of sentiment with bidder announcement returns is

11Draper and Paudyal(2006)?nd that bidder returns depend on both the listing status of the target and the method of payment;they?nd returns to acquirers of publicly listed targets to be worse in share than in cash?nanced acquisitions,but that bidders earn higher abnormal returns when paying in stock than with cash in acquisitions of private targets.

signi ?cantly negative on day +4(?0.072and signi ?cant at the 1%level),which is to an extent comparable,although slightly smaller than the initial over-reaction (0.120).The relation then remains mostly insigni ?cant for the remaining lead days.Merger arbitrageurs trade heavily around merger announcements,and therefore the response to misevaluations due to sentiment is expected to be imme-diate.However,since professional investors are still prone to behavioral biases (Glejser and Heyndels,2001;Kaplanski and Levy,2013;Kling and Gao,2008),albeit to a lesser extent than other market participants,a full recovery to the initial stock prices may not be expected to show up empirically.

3.4.What drives the relation between sentiment and bidder returns?

This section explores characteristics that drive the relation between sentiment and bidder returns.First,we hypothesize that the relation is more prominent in ?rms with a low percentage of shares owned by large blockholders,since smaller investors are likely to be more heavily in ?uenced by sentiment (e.g.,DeLong et al.,1990).12Second,we hypothesize that the relation between sentiment and bidder returns is stronger within public deals,since there is a higher likelihood for the merger announcement to attract more at-tention in public deals.Third,we test whether the ?rst two factors interact.If sentiment affects predominately private investors and deals with signi ?cant publicity,we expect the relation between sentiment and bidder returns to be particularly high in acquisitions of public targets by bidders with low levels of blockholder ownership.Fourth,we explore the in ?uence of relative size on the magnitude of the sentiment and return https://www.sodocs.net/doc/9515517876.html,rger deals can be expected to have a larger impact on the bidder,and therefore the sentiment and return relation should be more pronounced within large-size deals.

Panel A of Table 6shows the univariate results in sub-groups where a more/less pronounced relation with sentiment is ex-pected.Blockholder captures the total percentage of shares held by strategic investors who each hold a large stake.13To ex-plore whether GNH has a stronger relation with abnormal returns for companies with higher proportions of smaller investors,who may be more susceptible to behavioral biases than larger and more sophisticated investors,we use a Low Blockholder dummy variable that takes the value of one if blockholder ownership is less than 5%,and zero otherwise.14We

12

Note that we control for the size of the acquirer in multivariate analysis to ensure that our results are not driven by blockholder ownership being negatively cor-related with ?rm size.13

Regulations vary slightly between countries as to what stakes have to be reported to the stock exchange.For example,in the US stakes above 5%have to be reported,while in the UK the threshold is 3%.Given the different reporting requirements in different countries,we use a 5%cut-off to identify blockholder ownership.14

In untabulated results,we ?nd that alternative blockholder ownership de ?nitions,such as using a dummy variable that equals one for ownership of less than 10%,15%,and 20%,offers similar empirical results.

Table 6

Sub-group analysis:univariate results.

This table shows the univariate results regarding the relation of sentiment (GNH)with cumulative abnormal returns of bidders for a number of subgroups.In Panel A we explore the percentage of blockholder ownership in a ?rm,the target status ,and the relative size between bidder and target ?rms,while in Panel B we report results for the method of payment and the market capitalization (size )of bidders.Blockholder ownership indicates the percentage of shares held by strategic shareholders owning 5%or more.Targets may be private or public ?rms.We ?rst identify the top and bottom quartile per country for each characteristic and then rank them based on the level of sentiment.GNH and returns are estimated over the four-day period from the merger announcement to three days after (0,+3).N indicates the number of mergers available.p-Values are shown in parentheses.Results shown are for the full sample of seventeen countries.*,**,and ***indicate signi ?cance at the 10,5,and 1%levels,respectively.

Panel A:blockholder ownership,target status,and relative size

Blockholder Target status Low blockholder RelSize Low

High Public Private Public Private High Low High GNH (0,+3) 1.22*** 1.59***?0.17 2.23***?0.590.95** 4.80***0.66***(0.000)(0.000)(0.775)(0.000)(0.302)(0.045)(0.000)(0.003)N

5681092

264

963

106

256469

469Low GNH (0,+3)?0.23 1.21***?2.98*** 1.48***?3.82***?0.32 1.71**0.10(0.590)(0.000)(0.000)(0.000)(0.000)(0.642)(0.025)(0.730)N

567

1093

264

962106

256469

468High –low

1.45***0.39

2.81***0.75

3.23*** 1.27 3.08***0.56(0.007)

(0.334)

(0.002)

(0.127)

(0.006)

(0.130)

(0.002)

(0.136)

Panel B:method of payment and bidder size expectation

Method of payment Size Cash

Stock Mixed Large Small High GNH (0,+3) 1.34*** 4.73*** 1.93***0.84*** 5.07***(0.000)(0.000)(0.000)(0.000)(0.000)N

5642091108

469469

Low GNH (0,+3)0.45 2.07 1.05***?0.50 2.63***(0.163)(0.107)(0.001)(0.108)(0.001)N

564

2091107

469

468

High –low

0.88** 2.660.88** 1.34*** 2.44**(0.041)

(0.119)

(0.030)

(0.001)

(0.019)

173

J.Danbolt et al./Journal of Corporate Finance 33(2015)164–179

174J.Danbolt et al./Journal of Corporate Finance33(2015)164–179

also split the sample into high and low relative size groups based on quartiles.We?rst identify the top and bottom portfolio for each characteristic and then rank them based on GNH.

Results support the developed hypotheses.In particular,we?nd that the relation between GNH and bidder returns is more pro-nounced in companies with low rather than high blockholder ownership.The difference in returns between high and low GNH by bid-ders with low levels of blockholder ownership is1.45percentage points and signi?cant at the1%level,compared to an insigni?cant

Table7

Sub-group analysis:multivariate results.

This table explores within a multivariate analysis the relation of sentiment with bidder cumulative abnormal returns within alternative subgroups:low levels of strategic blockholder ownership,public targets,and high relative size of target to bidder mergers.The dependent variable is the percentage cumulative returns(CARs) estimated over the four-day period from the merger announcement to three days after(0,+3).Other explanatory variables are as de?ned in Table2.Standard errors are clustered by country.Country dummies,and eight lags on sentiment and on stock market returns,are included.p-Values are shown in parentheses.N indicates the number of observations.Results shown are for the full sample of seventeen countries.*,**,and***indicate signi?cance at the10,5,and1%levels,respectively.

(1)(2)(3)(4)

CARs(0,+3)CARs(0,+3)CARs(0,+3)CARs(0,+3)

GNH(0,+3)?0.0280.081**0.0110.021

(0.576)(0.012)(0.846)(0.663) LowBlock0.002?0.001

(0.172)(0.876)

LowBlock?GNH(0,+3)0.281***

(0.003)

Public?GNH(0,+3)0.276***

(0.002)

LowBlock?Public0.007

(0.422)

LowBlock?Private?0.002

(0.851)

LowBlock?Public?GNH(0,+3)0.477*

(0.065)

LowBlock?Private?GNH(0,+3)0.130

(0.521)

RelSizeHigh0.021***

(0.000) RelSizeHigh?GNH(0,+3)0.462***

(0.004)

LnMV?0.012***?0.015***?0.012***?0.012***

(0.000)(0.000)(0.000)(0.000) Public?0.033***?0.030***?0.034***?0.036***

(0.000)(0.000)(0.000)(0.000) Private?0.010***?0.010***?0.009**?0.008***

(0.000)(0.000)(0.032)(0.000)

Stock0.0050.008*0.0050.007

(0.491)(0.085)(0.487)(0.116)

Cash0.0030.0020.0030.003

(0.182)(0.386)(0.183)(0.245) RelSize0.006**0.002*0.006**0.001

(0.013)(0.092)(0.013)(0.201) BTMV0.0010.0010.0010.001

(0.782)(0.525)(0.775)(0.567) Domestic?0.006?0.009?0.006?0.009

(0.176)(0.127)(0.162)(0.113) Diversi?ed?0.002?0.001?0.002?0.001

(0.552)(0.542)(0.545)(0.768) Competitive0.018*0.024*0.017*0.025*

(0.058)(0.088)(0.065)(0.071) Tender0.014***0.013**0.014***0.014**

(0.001)(0.025)(0.001)(0.010) CARs?252,?20?0.002?0.005**?0.002?0.004**

(0.314)(0.041)(0.322)(0.048) DebtTA?0.004***0.002***?0.004***0.002***

(0.000)(0.000)(0.000)(0.000) CashFlow?0.003***0.001***?0.003***0.001***

(0.000)(0.000)(0.000)(0.000) Constant0.066***0.078***0.066***0.064***

(0.000)(0.000)(0.000)(0.000) Country dummies Yes Yes Yes Yes

Lagged sentiment Yes Yes Yes Yes

Lagged market returns Yes Yes Yes Yes

N5928649359286493

Adj.R-sq0.0680.0700.0670.074

0.39percentage points in acquisitions by bidders with counterpart high levels of blockholder ownership.15The difference in returns between high and low GNH deals is also 2.81%and signi ?cant at the 1%signi ?cance level for public deals,and 0.75%and insigni ?cant for private deals.The difference between high and low GNH for public targets of low blockholder ownership deals is a signi ?cant 3.23percentage points,while we ?nd no relation between GNH and bidder returns in acquisitions of private targets.Finally,the high minus low GNH difference in returns is 3.08%for high relative size transactions,and signi ?cant at the 1%level,and an insigni ?cant 0.56%for low relative size transactions.

For completeness,and to ensure that sentiment is related with stock returns,we also explore whether the relation between GNH and bidder abnormal returns also varies with the method of payment and the size of the bidder.Univariate results in relation to high and low GNH levels on the following subgroups:cash,stock and mixed methods of payment,and large and small size of bidding ?rms,are report-ed in Panel B of Table 6.We have no expectation as to whether the relation between investor sentiment and bidder abnormal returns will vary with the method of payment or ?rm size.We ?nd that the relation between GNH and stock returns overall holds across the alter-native subgroups.The difference in abnormal returns between high and low GNH states is,however,not quite statistically signi ?cant in stock ?nanced deals (p-value equal to 0.119),although the coef ?cient is economically signi ?cant at 2.66%.The lack of signi ?cance may be attributable to the relatively small number of stock ?nanced deals available.

Table 7shows the multivariate results,focusing on blockholder,target status,and the relative size of the acquisitions that we ear-lier developed hypotheses for.We construct dummy variables for each group of interest and interact them with GNH.We ?nd that our univariate results hold within multivariate analysis.In regression 1,we ?nd the absence of a blockholder to have a small and insignif-icant relation with bidder abnormal returns.However,more importantly,the large positive parameter coef ?cient (0.281)for the in-teractive variable LowBlock ?GNH (signi ?cant at the 1%level)indicates that the relation between GNH and bidder abnormal returns is more pronounced for the group of bidders where blockholders own a smaller fraction of shares.This is consistent with our prediction that smaller and arguably less sophisticated investors may be more susceptible to the in ?uence of sentiment.

The positive parameter coef ?cient (0.276)for the interactive variable Public*GNH (also signi ?cant at the 1%level)in the second regression supports the argument that the in ?uence of GNH on bidder returns is more pronounced for acquisitions of public target ?rms.In the third regression we look at the interaction between these two effects.As predicted,we ?nd the relation of sentiment to be particularly large (coef ?cient of 0.477and signi ?cant at the 10%level)in acquisitions of public targets by bidders with low

15

In untabulated results,we also test the trading volume around the announcement of the deals and ?nd that ?rms with both high and low blockholder ownership experience positive and signi ?cant abnormal trading activity around merger announcements.The difference in the relation between GNH and bidder announcement returns between the two groups is therefore unlikely to be driven by thin trading.

Table 8

GNH and CAR:US results.

This table explores within a multivariate framework whether the relation of sentiment with bidder returns holds within the sample of US mergers.The regression is estimated for the whole US sample as well as for subgroups based on strategic blockholder ownership,target status,the interaction between low ownership and the target status,and the relative size between targets and bidders.The dependent variable is the percentage cumulative abnormal returns (CARs)estimated over the four-day period from the merger announcement day to three days after (0,+3).Explanatory variables are the same as in Table 7.p-Values are shown in parentheses.N indicates the number of observations.*,**,and ***indicate signi ?cance at the 10,5,and 1%levels,respectively.

(1)

(2)

(3)

(4)

(5)

CARs (0,+3)

CARs (0,+3)CARs (0,+3)CARs (0,+3)CARs (0,+3)US-GNH (0,+3)0.115?0.0030.0520.045?0.013(0.198)

(0.973)(0.584)

(0.641)(0.897)

LowBlock

0.004?0.008(0.306)(0.122)

LowBlock*US-GNH (0,+3)0.490***(0.003)

Public*US-GNH (0,+3)0.415**(0.044)

LowBlock*Public 0.024**(0.018)LowBlock ?Private

0.011(0.133)LowBlock ?Public ?US-GNH (0,+3)0.736**(0.015)LowBlock ?Private ?US-GNH (0,+3)0.401*(0.094)

RelSizeHigh

0.020***(0.000)RelSizeHigh ?US-GNH (0,+3)0.570***(0.001)Firm characteristics Yes Yes Yes Yes Yes Merger characteristics Yes Yes Yes Yes Yes Lagged sentiment

Yes Yes Yes Yes Yes Lagged market returns Yes Yes Yes Yes Yes N

30633031306330313063Adj.R-sq

0.114

0.122

0.115

0.121

0.118

175

J.Danbolt et al./Journal of Corporate Finance 33(2015)164–179

176J.Danbolt et al./Journal of Corporate Finance33(2015)164–179

Table9

US results with the use of the Gallup Economic Con?dence Index.

This table explores within a multivariate framework the relation of sentiment,as proxied by the Gallup US Economic Con?dence Index,with bidder returns within the sample of US mergers.The dependent variable is the percentage cumulative abnormal returns(CARs)estimated over the four-day period from the merger announcement to three days after(0,+3).Explanatory variables are the same as in Table7.p-Values are shown in parentheses.N indicates the number of observations.Gallup's data commence on January2008.*,**,and***indicate signi?cance at the10,5,and1%levels,respectively.

(1)(2)(3)(4)(5)

CARs(0,+3)CARs(0,+3)CARs(0,+3)CARs(0,+3)CARs(0,+3)

US-Gallup(0,+3)0.055***0.035*0.030*0.043**0.036**

(0.001)(0.082)(0.087)(0.018)(0.045) LowBlock0.017*?0.007

(0.099)(0.214)

LowBlock?US-Gallup(0,+3)0.056**

(0.039)

Public?US-Gallup(0,+3)0.168***

(0.000)

LowBlock?Public0.063***

(0.003)

LowBlock?Private0.011

(0.426)

LowBlock?Public?US-Gallup(0,+3)0.147***

(0.008)

LowBlock?Private?US-Gallup(0,+3)0.023

(0.507)

RelSizeHigh0.043***

(0.000) RelSizeHigh?US-Gallup(0,+3)0.082***

(0.010)

Firm characteristics Yes Yes Yes Yes Yes

Merger characteristics Yes Yes Yes Yes Yes

Lagged sentiment Yes Yes Yes Yes Yes

Lagged market returns Yes Yes Yes Yes Yes

N27862763278627632786

Adj.R-sq0.1270.1300.1320.1310.131 blockholder ownership.Note that when we interact LowBlock?Private?GNH and LowBlock?Private,both parameter coef?cients are insigni?cant,highlighting the signi?cance of the public dummy on the magnitude of the relation between sentiment and bidder stock returns.

In the?nal regression,we study the relation between relative size and bidder stock returns.Not only do we?nd bidder abnormal returns to be higher where the acquisition is large relative to the size of the target(regression coef?cient of0.021and signi?cant at the 1%level),but the relation between sentiment and bidder stock returns(as captured by the interactive variable RelSizeHigh?GNH)is also signi?cantly higher in acquisitions of relatively large targets.The regression coef?cient of0.462is again signi?cant at the1%level. This is consistent with our expectations of a multiplier effect,with any error in target valuation by investors(overestimation of synergies or underestimation of risks)associated with sentiment biases having a stronger relation with bidder returns the larger the relative size of the target.

3.5.Results for US and non-US mergers

Results above are estimated for the pooled sample of all seventeen countries.Due to the importance of the US market in global M&A activity and the availability of an alternative daily proxy of sentiment for this market,we re-estimate prior multivariate results for the sub-sample of US acquisitions,and the remaining sub-sample of non-US acquisitions.16However,there are also reasons to ex-pect the relation between sentiment and bidder returns to vary between markets,particularly with regard to public deals,where we would expect different results in US versus non-US mergers.17We hypothesize above that mergers with public targets experience a more pronounced relation with sentiment due to media coverage that particularly in?uences the investment decisions of small inves-tors.However,the depth of media coverage of a topic may vary signi?cantly from one country to another.Wu(2000)compares news coverage of the same international news within38countries,and?nds that US coverage captures news by far the most https://www.sodocs.net/doc/9515517876.html, media is found to capture18%of the media space,with France,in second place,having merely9%.Therefore,we hypothesize that the relation between sentiment and bidder stock returns is more pronounced in acquisitions of US public targets than in acqui-sitions of public?rms in other markets.Note that the control variables used in this section are the same as those used in the multivar-iate analysis above,but we only report the parameter coef?cients of interest for space considerations.

16In untabulated results,we?nd that US univariate results show the same trends in line with reported multivariate results.

17The limited number of mergers in several countries also restricts the extent to which detailed cross-country comparisons can be undertaken.

Table 8shows the results for the relation between US-GNH and bidder announcement returns as well as the results for character-istics found earlier to be related with the strength of the relation between key variables under study.We ?nd that US results are rel-atively similar to those found for the full https://www.sodocs.net/doc/9515517876.html,-GNH is positively related with returns (0.115),although not quite statistically signi ?cant at conventional levels,as shown in regression 1.The relation between US-GNH and returns is more prominent within ?rms with a low percentage of blockholder ownership (regression 2),in acquisitions of public targets (regression 3),when the two characteristics are interacted (regression 4),and in high relative size acquisitions (regression 5).

An alternative daily sentiment index is available for the US —the Gallup Economic Con ?dence index.We use this to explore whether our results hold when using an alternative daily sentiment index.Note that the sample period is shorter than in the main analysis,as Gallup's Index data commence in January 2008(while GNH goes back to September 2007).In short,the Gallup Index is calculated based on phone interviews with 1500Americans aged 18or over,during which interviewees are asked to rate their expec-tations for the future.In untabulated results,we ?nd that the Pearson correlation between US-Gallup and US-GNH is 0.390and signif-icant at the 1%level,giving the ?rst indication that similar results may be obtained for both indexes.Table 9shows multivariate results when using US-Gallup.We ?nd that with the use of US-Gallup,we arrive at qualitatively similar conclusions to those obtained using US-GNH,showing that our previous results are not driven by the use of the GNH proxy.In particular,we ?nd that there is a positive relation between US-Gallup and bidder announcement returns.The parameter coef ?cient on US-Gallup is 0.055,which is signi ?cant at the 1%level.The relation between US-Gallup and bidder returns is also more prominent for bidders with low blockholder owner-ship,in acquisitions of public targets,in the interaction of low ownership and acquisition of public target ?rms,and in high relative target size deals.

We further explore non-US results in Table 10.In line with results for the US and the full sample of countries,NonUS-GNH is pos-itively related with returns (0.110)and signi ?cant at the 5%level.Also,the relation between NonUS-GNH and returns is more prom-inent within ?rms with a low percentage of blockholder ownership,and in high relative size acquisitions.However,the parameter coef ?cients regarding acquisitions of public targets are insigni ?cant,possibly due to the lower level of media coverage of ?nancial news in less developed countries in relation to the US market (Wu,2000).In untabulated results,we support that sentiment is related with bidder abnormal announcement returns more prominently in public targets of other highly developed countries (in addition to the US market),such as within a number of European countries.These results offer an international dimension of the signi ?cance of media coverage in public acquisitions.

Table 10

GNH and CAR:non-US results.

This table explores within a multivariate framework whether the relation of sentiment with bidder returns holds within the remaining countries when excluding US mergers (NonUS).The regression is estimated for the NonUS sample as well as for subgroups based on strategic blockholder ownership,target status,the interaction between low ownership and the target status,and the relative size between targets and bidders.The dependent variable is the percentage cumulative abnormal returns (CARs)estimated over the four-day period from the merger announcement to three days after (0,+3).Explanatory variables are the same as in Table 7.p-Values are shown in parentheses.N indicates the number of observations.Results shown are for the sample of sixteen countries.*,**,and ***indicate signi ?cance at the 10,5,and 1%levels,respectively.

(1)

(2)

(3)

(4)

(5)

CARs (0,+3)

CARs (0,+3)CARs (0,+3)CARs (0,+3)CARs (0,+3)NonUS-GNH (0,+3)0.110**?0.1070.085*?0.0530.037(0.046)

(0.212)(0.062)

(0.569)(0.576)

LowBlock

0.0010.006(0.564)(0.220)

LowBlock ?NonUS-GNH (0,+3)0.211*(0.072)

Public ?NonUS-GNH (0,+3)0.193(0.243)

LowBlock ?Public ?0.005(0.549)LowBlock ?Private

?0.013(0.175)LowBlock ?Public ?NonUS-GNH(0,+3)0.418(0.361)LowBlock ?Private ?NonUS-GNH (0,+3)?0.029(0.855)

RelSizeHigh

0.015***(0.005)RelSizeHigh ?NonUS-GNH (0,+3)0.335*(0.055)Firm characteristics Yes Yes Yes Yes Yes Merger characteristics Yes Yes Yes Yes Yes Country dummies Yes Yes Yes Yes Yes Lagged sentiment

Yes Yes Yes Yes Yes Lagged market returns Yes Yes Yes Yes Yes N

34302897343028973430Adj.R-sq

0.061

0.050

0.061

0.050

0.063

177

J.Danbolt et al./Journal of Corporate Finance 33(2015)164–179

178J.Danbolt et al./Journal of Corporate Finance33(2015)164–179

4.Conclusion

While a number of factors have been previously put forward to explain bidder returns,little empirical investigation has been undertaken on the signi?cance of behavioral aspects.We use a direct measure of daily sentiment data available from Facebook across seventeen international markets to capture sentiment on the days surrounding mergers and explore its relation with bidder announcement abnormal returns.We argue that investors are subconsciously in?uenced by their sentiment,which may bias their es-timation of expected synergies and risks from mergers;therefore,sentiment is expected to be related with bidder announcement returns.

Prior literature(e.g.,Siganos et al.,2014)has found a positive relation between sentiment and the general stock market index,and we similarly?nd such a relation.However,our study goes beyond the conventional relation between sentiment and stock returns by focusing on the relation between sentiment and bidders'abnormal returns at the time of the bid announcement.By controlling for the ‘normal’relation between sentiment and share returns,we thus capture the extent to which the relation between sentiment and share returns is different during acquisition periods compared to other times.Given that acquisitions are generally large investments, any behavioral biases in investors'assessment of synergies or risks may be expected to have a signi?cant impact on?rm value.We?nd empirical evidence of sentiment being positively related with bidder announcement abnormal returns.The relation analyzed in this study goes beyond the conventional relation between sentiment and stock market returns reported by earlier behavioral studies, since bidder stock returns are market-adjusted.The relation is only present during the merger period,while the relation is insigni?-cant when testing within a period prior to merger announcements.We also?nd that the relation between sentiment and bidder returns is higher for bidders with low levels of blockholder ownership,consistent with predictions that smaller investors and less in-formed traders are more susceptible to behavioral biases,especially in acquisitions which are more likely to attract signi?cant media attention.The effect is also larger in acquisitions of public targets within US markets with signi?cant media coverage,and in acquisi-tions of relatively large targets.Our evidence suggests that the relation between sentiment and bidder abnormal returns is the out-come of irrational behavior.Sentiment appears to in?uence investors'assessment of expected synergies and risks involved in an acquisition.We conclude that sentiment is an important factor to control for when exploring bidder announcement abnormal returns. Acknowledgments

We are grateful to an anonymous referee,Jeffry Netter(the editor),Ilanit Gavious,Marc Goergen,Alan Goodacre,Dimitris Petmezas,Bill Rees,Lucia Spotorno,Yannis Tsalavoutas,Patrick Verwijmeren,Betty Wu,participants at the BAFA(London)2014, EFMA(Rome)2014,and WFC(Venice)2014conferences,and seminar participants at the Universities of Edinburgh,Glasgow,and Stirling for helpful comments on previous versions of this paper.Jo Danbolt holds the Baillie Gifford Chair in Financial Markets,and his research is partially funded by a Baillie Gifford endowment held by the University of Edinburgh Business School.Baillie Gifford has no role in or in?uence over the research conducted.

References

Asquith,P.,Bruner,F.,Mullins,D.,1983.The gains to bidding firms from merger.J.Financ.Econ.11,121–139.

Barber,M.,Odean,T.,2008.All that glitters:the effect of attention and news on the buying behavior of individual and institutional investors.Rev.Financ.Stud.21, 786–818.

Bless,H.,Gerald,L.,Clore,N.,Schwarz,V.,Rabe,C.,Wolk,M.,1996.Mood and the use of scripts:does being in a happy mood really lead to mindlessness?J.Pers.Soc.

Psychol.71,665–679.

Bouwman,C.H.S.,Fuller,K.,Naoin,A.,2009.Market valuation and acquisition quality:empirical evidence.Rev.Financ.Stud.22,633–679.

Chang,S.,1998.Takeovers of privately held targets,methods of payment,and bidder returns.J.Financ.53,773–784.

Chow,G.,1960.Tests of equality between sets of coefficients in two linear regressions.Econ.28,591–605.

Danbolt,J.,MacIver,G.,2012.Cross-border versus domestic acquisitions and the impact on shareholder wealth.J.Bus.Fin.Acc.39,1028–1067.

DeLong,B.,Shleifer,A.,Summers,L.,Waldmann,R.,1990.Noise trader risk in financial markets.J.Polit.Econ.98,703–738.

Draper,P.,Paudyal,K.,2006.Acquisitions:private versus public.Eur.Financ.Manag.12,57–80.

Eckbo,N.E.,2009.Bidding strategies and takeover premiums:a review.J.Corp.Fin.16,149–178.

Edmans,A.,Garcia,D.,Norli,O.,2007.Sport sentiment and stock returns.J.Financ.4,1967–1998.

Faccio,M.,Masulis,R.,2005.The choice of payment method in European mergers and acquisitions.J.Financ.60,1345–1388.

Fama,E.F.,1970.Efficient capital markets:a review of theory and empirical work.J.Financ.25,383–417.

Fang,L.,Peress,J.,2009.Media coverage and the cross-section of stock returns.J.Financ.64,2023–2052.

Fuller,K.,Netter,J.,Stegemoller,M.,2002.What do returns to acquiring firms tell us?Evidence from firms that make many acquisitions.J.Financ.57,1763–1793. Glejser,H.,Heyndels,B.,2001.Efficiency and inefficiency in the ranking in competitions:the case of the Queen Elisabeth music contest.J.Cult.Econ.25,109–129. Hirshleifer,D.,Shumway,T.,2003.Good day sunshine:stock returns and the weather.J.Financ.58,1909–1932.

Johnson,E.,Tversky,A.,1983.Affect,generalization,and the perception of risk.J.Pers.Soc.Psych.45,20–31.

Kaplanski,G.,Levy,H.,2010.Sentiment and stock prices:the case of aviation disasters.J.Financ.Econ.95,174–201.

Kaplanski,G.,Levy,H.,2013.Analysts and Sentiment:A Causality Study.Working paper.

Kaplanski,G.,Levy,H.,Veld,C.,Veld-Merkoulova,Y.,2015.Do happy people make optimistic investors?J.Financ.Quant.Anal.50,145–168.

Karabulut,Y.,2013.Can Facebook Predict Stock Market Activity?Working paper

Karampatsas,N.,Petmezas,D.,Travlos,N.,2014.Credit ratings and the choice of payment method in mergers and acquisitions.J.Corp.Fin.25,474–493.

King,M.,2009.Prebid run-ups ahead of Canadian takeovers:how big is the problem?Financ.Manag.699–726.

Kling,G.,Gao,L.,2008.Chinese institutional investors'sentiment.Int.Financ.Mark.Inst.Money18,374–387.

Kramer,A.,2010.An unobtrusive behavioral model of Gross National Happiness.Proceedings CHI.ACM Press,pp.287–290.

Kramer,A.,Chung,K.,2011.Dimensions of self-expression in Facebook status updates.Proceedings of the5th International AAAI Conference on Weblogs and Social Media.

Kramer,A.D.I.,Guillory,J.E.,Hancock,J.T.,2014.Experimental evidence of massive-scale emotional contagion through social networks.Psych.Cogn.Sci.111, 8788–8790.

Kuchler,H.,2014.Facebook clicks on the ‘buy ’button.Financial Times 19/20July,14.

Lemmon,M.,Portniaguina,E.,2006.Consumer confidence and asset prices:some empirical evidence.Rev.Financ.Stud.19,1499–1529.Loewenstein,G.,Elke,F.,Weber,U.,Hsee,C.,Welch,N.,2001.Risk as feelings.Psych.Bull.127,267–286.

Mitchell,R.,Phillips,L.,2007.The psychological,neurochemical and functional neuroanatomical mediators of the effects of positive and negative mood on executive

functions.Neuropsychologia 45,617–629.

Moeller,S.,Schlingemann,F.,Stulz,R.,2004.Firm size and the gains from acquisitions.J.Financ.Econ.73,201–228.

Officer,M.S.,2007.Are performance based arbitrage effects detectable?Evidence from merger arbitrage.J.Corp.Fin.13,793–812.

Palomino,F.,Renneboog,L.,Zhang,C.,https://www.sodocs.net/doc/9515517876.html,rmation salience,investor sentiment,and stock returns:the case of British soccer betting.J.Corp.Fin.15,368–387.Petersen,M.A.,2009.Estimating standard errors in finance panel data set:comparing approaches.Rev.Financ.Stud.22,435–480.Rau,P.,Vermaelen,T.,1998.Glamour,value and the post-acquisition performance of acquiring firms.J.Financ.Econ.49,223–253.Rhodes-Kropf,M.,Viswanathan,S.,2004.Market valuation and merger waves.J.Financ.59,2685–2718.

Rhodes-Kropf,M.,Robinson,D.T.,Viswanathan,S.,2005.Valuation waves and merger activity:the empirical evidence.J.Financ.Econ.77,561–603.Rosen,R.J.,2006.Merger momentum and investor sentiment:the stock market reaction to merger announcements.J.Bus.79,987–1017.Shleifer,A.,Vishny,R.,2003.Stock market driven acquisitions.J.Financ.Econ.70,295–311.

Siganos,A.,Vagenas-Nanos,E.,Verwijmeren,P.,2014.Facebook's daily sentiment and international stock https://www.sodocs.net/doc/9515517876.html,an.107,730–743.

Sudarsanam,S.,Mahate,A.,2003.Glamour acquirers,method of payment and post-acquisition performance:the U.K.evidence.J.Bus.Fin.Acc.30,299–341.Titman,S.,Wei,K.,Xie,F.,2004.Capital investments and stock returns.J.Financ.Quant.Anal.39,677–700.

Travlos,N.,1987.Corporate takeover bids,methods of payment,and bidding firms stock returns.J.Financ.42,943–963.

Vitrue,2010.Managing Your Facebook Community:Findings on Conversation Volume by Day of Week,Hour and Minute.White paper.Wright,W.,Bower,G.,1992.Mood effects on subjective probability https://www.sodocs.net/doc/9515517876.html,an.Behav.Hum.Decis.Process.52,276–291.Wu,H.,2000.Systemic determinants of international news coverage:a comparison of https://www.sodocs.net/doc/9515517876.html,mun.50,110–130.

179

J.Danbolt et al./Journal of Corporate Finance 33(2015)164–179

脐带干细胞综述

脐带间充质干细胞的研究进展 间充质干细胞（mesenchymal stem cells,MSC S ）是来源于发育早期中胚层 的一类多能干细胞[1-5]，MSC S 由于它的自我更新和多项分化潜能，而具有巨大的 治疗价值 ,日益受到关注。MSC S 有以下特点：(1)多向分化潜能，在适当的诱导条件下可分化为肌细胞[2]、成骨细胞[3、4]、脂肪细胞、神经细胞[9]、肝细胞[6]、心肌细胞[10]和表皮细胞[11, 12]；(2)通过分泌可溶性因子和转分化促进创面愈合；(3) 免疫调控功能，骨髓源（bone marrow ）MSC S 表达MHC-I类分子，不表达MHC-II 类分子，不表达CD80、CD86、CD40等协同刺激分子，体外抑制混合淋巴细胞反应，体内诱导免疫耐受[11, 15]，在预防和治疗移植物抗宿主病、诱导器官移植免疫耐受等领域有较好的应用前景；(4)连续传代培养和冷冻保存后仍具有多向分化潜能，可作为理想的种子细胞用于组织工程和细胞替代治疗。1974年Friedenstein [16] 首先证明了骨髓中存在MSC S ，以后的研究证明MSC S 不仅存在于骨髓中，也存在 于其他一些组织与器官的间质中：如外周血[17]，脐血[5]，松质骨[1, 18]，脂肪组织[1]，滑膜[18]和脐带。在所有这些来源中，脐血(umbilical cord blood)和脐带(umbilical cord)是MSC S 最理想的来源，因为它们可以通过非侵入性手段容易获 得，并且病毒污染的风险低，还可冷冻保存后行自体移植。然而，脐血MSC的培养成功率不高[19, 23-24]，Shetty 的研究认为只有6%，而脐带MSC的培养成功率可 达100%[25]。另外从脐血中分离MSC S ，就浪费了其中的造血干/祖细胞(hematopoietic stem cells/hematopoietic progenitor cells,HSCs/HPCs) [26, 27]，因此，脐带MSC S (umbilical cord mesenchymal stem cells, UC-MSC S )就成 为重要来源。 一．概述 人脐带约40 g, 它的长度约60–65 cm, 足月脐带的平均直径约1.5 cm[28, 29]。脐带被覆着鳞状上皮，叫脐带上皮，是单层或复层结构，这层上皮由羊膜延续过来[30, 31]。脐带的内部是两根动脉和一根静脉，血管之间是粘液样的结缔组织，叫做沃顿胶质，充当血管外膜的功能。脐带中无毛细血管和淋巴系统。沃顿胶质的网状系统是糖蛋白微纤维和胶原纤维。沃顿胶质中最多的葡萄糖胺聚糖是透明质酸，它是包绕在成纤维样细胞和胶原纤维周围的并维持脐带形状的水合凝胶，使脐带免受挤压。沃顿胶质的基质细胞是成纤维样细胞[32]，这种中间丝蛋白表达于间充质来源的细胞如成纤维细胞的，而不表达于平滑肌细胞。共表达波形蛋白和索蛋白提示这些细胞本质上肌纤维母细胞。 脐带基质细胞也是一种具有多能干细胞特点的细胞，具有多项分化潜能，其 形态和生物学特点与骨髓源性MSC S 相似[5, 20, 21, 38, 46]，但脐带MSC S 更原始，是介 于成体干细胞和胚胎干细胞之间的一种干细胞，表达Oct-4, Sox-2和Nanog等多

二、分析天平的基本操作

模块二滴定分析基本操作任务一分析天平的基本操作 一、分析天平的分类 分析天平是定量分析中最常用的准确称量物质的仪器。分析天平分类：等臂（双盘）分析天平、不等臂（单盘）分析天平、电子天平。 二、电子天平的介绍 1、工作原理：电磁平衡原理，秤盘通过支架连杆支架作用于线圈上，重力方向向下。线圈内有电流通过时，根据电磁基本理论，通电的导线在磁场中将产生一个向上作用的电磁力，与秤盘重力方向相反大小相同，与之相平衡，而通过导线的电流与被称物体的质量成正比。 2、性能特点：a.使用寿命长，性能稳定，灵敏度高，体积小，操作方便 b.称 量速度快、精度高 c.具有自动校准、累计称量、超载显示、自动去皮等功能 3、称量的一般程序 水平调节——打扫——预热——开启显示器——校准——称量——结束工作 ①水平调节检查水平仪，调节水平调节脚，使水泡位于水平仪中心。 ②打扫打扫天平秤盘 ③预热通电预热30min以上 ④开启显示器按ON键，显示器亮，显示屏出现0.0000g ⑤校准按“校准”键 ⑥称量被称物置于秤盘中间进行称量 ⑦称量结束工作取下被称物，核对零点，关闭天平，进行使用登记 4、基本称量方法 ①直接称量法将称量物直接放在天平盘上直接称量物体的质量。例如，称量 小烧杯的质量，容量器皿校正中称量某容量瓶的质量，重量分析实验中称量某坩埚的质量等，都使用这种称量法。 ②固定质量称量法

用于称量某一固定质量的试剂(如基准物质)或试样。适于称量不易吸潮、在空气中能稳定存在的粉末状或小颗粒样品。 A、去皮将干燥的容器置于秤盘上，待显示平衡后按“去皮”键扣除皮重并显示零点 B、加样打开天平门，用药匙将试样抖入容器内，使之达到所需质量。 固定质量称量法注意：若不慎加入试剂超过指定质量，用牛角匙取出多余试剂，直至试剂质量符合指定要求为止。严格要求时，取出的多余试剂应弃去，不要放回原试剂瓶中。操作时不能将试剂散落于天平盘等容器以外的地方，称好的试剂必须定量地由表面皿等容器直接转入接受容器，此即所谓“定量转移”。 ③递减称量法（减量法） 用于称量一定质量范围的样品或试剂。样品易吸水、易氧化或易与二氧化碳等反应时，可选择此法。。 称量步骤：试样的保存——取出盛试样的称量瓶——称出称量瓶质量——敲样——再称出其质量——样品质量——连续称样——称量工作结束 A、试样保存待称样品放于洁净的干燥容器（称量瓶）中，置于干燥器中保存 B、取出称量瓶左手戴手套取出称量瓶或者用折叠成约1cm的纸取出 C、称出称量瓶质量称出称量瓶质量，记录数据 D、敲样将称量瓶取出，在接收容器的上方倾斜瓶身，用称量瓶盖轻敲瓶口上部使试样慢慢落入容器中，瓶盖始终不要离开接受器上方。当倾出的试样接近所需量时，一边继续用瓶盖轻敲瓶口，一边逐渐将瓶身竖直，使粘附在瓶口上的试样落回称量瓶，然后盖好瓶盖，准确称其质量。两次质量之差，即为试样的质量。按上述方法连续递减，可称量多份试样。

外阴白色病变考试试题

外阴白色病变考试试题 一、A1型题（本大题11小题．每题1.0分，共11.0分。每一道考试题下面有A、 B、C、D、E五个备选答案。请从中选择一个最佳答案，并在答题卡上将相应题号的相应字母所属的方框涂黑。） 第1题 外阴硬化性苔癣的早期病理改变是 A 表层细胞过度角化 B 表层细胞增生 C 真皮乳头层水肿 D 毛囊角质栓塞 E 底层细胞增生 【正确答案】：C 【本题分数】：1.0分 第2题 女，50岁。因外阴瘙痒而就医，组织病理为增生型，营养不良，下列治疗中哪项是正确的 A 因有恶变趋向，应及早手术治疗 B 全身治疗 C 补充多量维生素 D 活检有非典型增生时手术治疗 E 全身+局部治疗 【正确答案】：D 【本题分数】：1.0分 第3题 关于外阴瘙痒下列哪项是正确的 A 外阴瘙痒是外阴癌的早期表现 B 外阴瘙痒最常见的原因是蛲虫病

C 外阴瘙痒严重时用肥皂液清洗会有所好转 D 外阴瘙痒经治疗无效应作单纯性外阴切除术 E 外阴瘙痒不是一种疾病而是多种疾病可引起的一种症状 【正确答案】：E 【本题分数】：1.0分 第4题 女，37岁。外阴奇痒，分泌物不多。妇检：两侧小阴唇增厚，外阴粘膜不红，阴道畅，皱襞正常，无异常分泌物，宫颈柱状，光滑，I°肥大，子宫前位，常大，双附件(-)，为确诊应选用 A 外阴活检 B 阴道分泌物涂片 C 宫颈涂片(CG D 阴道镜 E 盆腔B超 【正确答案】：A 【本题分数】：1.0分 第5题 属于癌前病变的外阴白色病变是 A 增生型营养不良 B 硬化苔癣型营养不良 C 混合型营养不良 D 营养不良伴有上皮不典型增生 E 白癜风 【正确答案】：D 【本题分数】：1.0分 第6题

精神分裂症的病因及发病机理

精神分裂症的病因及发病机理 精神分裂症病因：尚未明，近百年来的研究结果也仅发现一些可能的致病因素。（一）生物学因素1．遗传遗传因素是精神分裂症最可能的一种素质因素。国内家系调查资料表明：精神分裂症患者亲属中的患病率比一般居民高6.2倍，血缘关系愈近，患病率也愈高。双生子研究表明：遗传信息几乎相同的单卵双生子的同病率远较遗传信息不完全相同 的双卵双生子为高，综合近年来11项研究资料：单卵双生子同病率（56.7%），是双卵双生子同病率（12.7%）的4.5倍，是一般人口患难与共病率的35-60倍。说明遗传因素在本病发生中具有重要作用，寄养子研究也证明遗传因素是本症发病的主要因素，而环境因素的重要性较小。以往的研究证明疾病并不按类型进行遗传，目前认为多基因遗传方式的可能性最大，也有人认为是常染色体单基因遗传或多源性遗传。Shields发现病情愈轻，病因愈复杂，愈属多源性遗传。高发家系的前瞻性研究与分子遗传的研究相结合，可能阐明一些问题。国内有报道用人类原癌基因Ha-ras-1为探针，对精神病患者基因组进行限止性片段长度多态性的分析，结果提示11号染色体上可能存在着精神分裂症与双相情感性精神病有关的DNA序列。2．性格特征：约40%患者的病前性格具有孤僻、冷淡、敏感、多疑、富于幻想等特征，即内向

型性格。3．其它：精神分裂症发病与年龄有一定关系，多发生于青壮年，约1/2患者于20～30岁发病。发病年龄与临床类型有关，偏执型发病较晚，有资料提示偏执型平均发病年龄为35岁，其它型为23岁。80年代国内12地区调查资料：女性总患病率（7.07%。）与时点患病率（5.91%。）明显高于男性（4.33%。与3.68%。）。Kretschmer在描述性格与精神分裂症关系时指出：61%患者为瘦长型和运动家型，12.8%为肥胖型，11.3%发育不良型。在躯体疾病或分娩之后发生精神分裂症是很常见的现象，可能是心理性生理性应激的非特异性影响。部分患者在脑外伤后或感染性疾病后发病；有报告在精神分裂症患者的脑脊液中发现病毒性物质；月经期内病情加重等躯体因素都可能是诱发因素，但在精神分裂症发病机理中的价值有待进一步证实。（二）心理社会因素1．环境因素①家庭中父母的性格，言行、举止和教育方式（如放纵、溺爱、过严）等都会影响子女的心身健康或导致个性偏离常态。②家庭成员间的关系及其精神交流的紊乱。③生活不安定、居住拥挤、职业不固定、人际关系不良、噪音干扰、环境污染等均对发病有一定作用。农村精神分裂症发病率明显低于城市。2．心理因素一般认为生活事件可发诱发精神分裂症。诸如失学、失恋、学习紧张、家庭纠纷、夫妻不和、意处事故等均对发病有一定影响，但这些事件的性质均无特殊性。因此，心理因素也仅属诱发因

外阴疾病

外阴疾病 外阴：阴道口外边的外露部分肛门、阴道口及尿道邻近，经常受阴道分泌物及尿液的浸渍，容易发炎。 常见病症：外因瘙痒、外阴炎、外阴白色病变、外因溃疡、外阴癌 外阴疾病 外阴：阴道口外边的外露部分肛门、阴道口及尿道邻近，经常受阴道分泌物及尿液的浸渍，容易发炎。 常见病症：外因瘙痒、外阴炎、外阴白色病变、外因溃疡、外阴癌 外因瘙痒 外阴瘙痒是妇科疾病中很常见的一种症状，外阴是特别敏感的部位，妇科多种病变及外来刺激均可引起瘙痒，使人寝食难安、坐卧不宁。外阴瘙痒多发生于阴蒂、小阴唇，也可波及大阴唇、会阴和肛周 病因：1.慢性局部刺激，外阴、阴道、宫颈炎症的异常分泌物的刺激； 2.外阴不清洁及紧身化纤内裤、卫生巾等致通透不良； 3.外阴寄生虫病，如阴虱、蛲虫、疥疮等； 4.各种外阴皮肤病和外阴肿瘤等； 5.全身性疾病的外阴局部症状，如糖尿病、尿毒症、维生素缺乏等。 症状：外因皮肤瘙痒、烧灼感和疼痛瘙痒部位多生与阴帝、小阴唇、也可波及大阴、会阴、甚至肛周围 危害：(1)性外阴部瘙痒严重时，不但使人坐卧不宁，影响工作、学习、生活和睡眠。 (2)由于女性外阴瘙痒，会影响夫妻生活，所以极有导致夫妻感情不和，严重的 甚至造成感情破裂，婚姻走向终点。 (3)诱发生殖器感染，盆腔炎、肾周炎、性交痛等，日久不愈还可导致多种疾病 同时发生，疾病的危害严重的会危害女性健康，甚至还会造成女性不孕等严重后果。 (4)女性外阴瘙痒严重时，不易根治，易反复，引发早产、胎儿感染畸形等，造 成终身遗憾。 治疗1.外阴涂药

使用有止痒作用的洗剂、膏霜等，如炉甘石洗剂、苯海拉明软膏、皮质醇类软膏等。 2.局部封闭或穴位注药 如皮质醇激素、维生素B12、非那根等。 3.针对病因治疗。 4.预防1. 注意经期卫生，勤清洗。 2.不要冲洗阴道，因为阴道有自清的功能，如果刻意冲洗反而不利 3.忌乱用、烂用药物，忌抓搔及局部摩擦。 4.忌酒及辛辣食物，不吃海鲜等及易引起过敏的药物 6 .久治不愈者应作血糖检查。少吃糖类可避免常常感染霉菌，如少吃淀粉类、糖类以及刺激性的食物(例如酒、辛辣物、油炸类)，多吃蔬菜水果类，水份要充足。 5、不穿紧身兜裆裤，内裤更须宽松、透气，并以棉制品为宜。 6.就医检查是否有霉菌或滴虫，如有应及时治疗，而不要自己应用“止痒水”治疗。 8.保持外阴清洁干燥，尤其在经期、孕期、产褥期，每天用女性护理液清洗外阴更换内裤。 9.不穿化纤内裤、紧身裤，着棉织内衣裤。局部坐浴时注意溶液浓度、温度及时间、注意事项。 10.外阴瘙痒者应勤剪指甲、勤洗手，不要搔抓皮肤，以防破溃感染从而继发细菌性感染。 11.上完厕所请记得由前往后擦，因为肛门可能会带来不少细菌，所以如厕后请不要由肛门擦到阴部，才能减少感染的机会。 12.内裤要和其他的衣物分开洗，最好暴晒，可以减少细菌的滋生。如果患有霉菌性阴道炎的话，最好内裤都有热水煮 外阴溃疡外阴溃疡是发生于外阴部的皮肤黏膜发炎、溃烂、缺损。病灶多发生于小阴唇和大阴唇内侧，其次为前庭黏膜及阴道口周围。病程有急性及慢性。 大小阴唇、阴道口周围、阴蒂等处（外阴疾病发展中出现的一个过程，不是一个独立的疾病，有急性和慢性）急性外阴溃疡：非特异性外阴炎病情较轻，多在搔抓之后出现一般比较表浅，但疼痛比较厉害 慢性外阴溃疡：持续时间较长，或者反复发作 癌症引起的溃疡，与结核性溃疡很难鉴别，需做确诊

脐带血造血干细胞库管理办法(试行)

脐带血造血干细胞库管理办法（试行） 第一章总则 第一条为合理利用我国脐带血造血干细胞资源，促进脐带血造血干细胞移植高新技术的发展，确保脐带血 造血干细胞应用的安全性和有效性，特制定本管理办法。 第二条脐带血造血干细胞库是指以人体造血干细胞移植为目的，具有采集、处理、保存和提供造血干细胞 的能力，并具有相当研究实力的特殊血站。 任何单位和个人不得以营利为目的进行脐带血采供活动。 第三条本办法所指脐带血为与孕妇和新生儿血容量和血循环无关的，由新生儿脐带扎断后的远端所采集的 胎盘血。 第四条对脐带血造血干细胞库实行全国统一规划，统一布局，统一标准，统一规范和统一管理制度。 第二章设置审批 第五条国务院卫生行政部门根据我国人口分布、卫生资源、临床造血干细胞移植需要等实际情况，制订我 国脐带血造血干细胞库设置的总体布局和发展规划。 第六条脐带血造血干细胞库的设置必须经国务院卫生行政部门批准。 第七条国务院卫生行政部门成立由有关方面专家组成的脐带血造血干细胞库专家委员会（以下简称专家委

员会），负责对脐带血造血干细胞库设置的申请、验收和考评提出论证意见。专家委员会负责制订脐带血 造血干细胞库建设、操作、运行等技术标准。 第八条脐带血造血干细胞库设置的申请者除符合国家规划和布局要求，具备设置一般血站基本条件之外， 还需具备下列条件： （一）具有基本的血液学研究基础和造血干细胞研究能力； （二）具有符合储存不低于1 万份脐带血的高清洁度的空间和冷冻设备的设计规划； （三）具有血细胞生物学、HLA 配型、相关病原体检测、遗传学和冷冻生物学、专供脐带血处理等符合GMP、 GLP 标准的实验室、资料保存室； （四）具有流式细胞仪、程控冷冻仪、PCR 仪和细胞冷冻及相关检测及计算机网络管理等仪器设备； （五）具有独立开展实验血液学、免疫学、造血细胞培养、检测、HLA 配型、病原体检测、冷冻生物学、 管理、质量控制和监测、仪器操作、资料保管和共享等方面的技术、管理和服务人员； （六）具有安全可靠的脐带血来源保证； （七）具备多渠道筹集建设资金运转经费的能力。 第九条设置脐带血造血干细胞库应向所在地省级卫生行政部门提交设置可行性研究报告，内容包括：

电子天平使用说明书.

电子天平使用说明书 使用方法 ◎准备 1、将天平安放在稳定及水平的工作台上,避免振动、气流、阳光直射和剧烈的温度波动; 2、安装称盘; 3、接通电源前请确认当地交流电压是否与天平所附的电源适配器所需电压一致; 4、为获得准确的称量结果,在进行称量前天平应接通电源预热30分钟。 ◎电源 1. 天平随机附配交流电源适配器,输入220+22-33V ~ 50Hz 输出9V 300mA 2. 天平选用电池供电时可打开天平底部的电池盖按极性指示装入电池即可,建议使用9伏碱性电池,可连续工作约12小时。 当天平电池供电时,显示屏左上角电量指示框显示段数表明电池的状态(显示3段:电池充足,显示0段:电池耗尽,当电池电量将耗尽时,最后一个显示段闪烁。 ◎开机 在称盘空载情况下按<开/关>键,天平依次进入自检显示(显示屏所有字段短时点亮、型号显示和零状态显示,当天平显示零状态时即可进行称量; 当遇到相关功能键设置有误无法恢复时,按<开/关>键重新开机即可恢复初始设置状态。

◎校准 为获得准确的称量结果,必须对天平进行校准以适应当地的重力加速度。校准应在天平预热结束后进行,遇到以下情况必须使用外部校准砝码对天平进行校准。 1. 首次使用天平称量之前; 2. 天平改变安放位置后。 校准方法与步骤: 1.准备好校准用的标准砝码并确保称盘空载; 2.按<去皮>键:天平显示零状态; 3.按<校准>键:天平显示闪烁的CAL—XXX,(XXX一般为100、200或其它数字,提醒使用相对应的100g、200g或其它规格的标准砝码 4.将标准砝码放到称盘中心位置,天平显示CAL-XXX,等待几秒钟后,显示标准砝码的量值。此时移去砝码,天平显示零状态,则表示校准结束,可以进行称量。如天平不零状态,应重复进行一次校准工作。 ◎称量 天平经校准后即可进行称量,称量时必须等显示器左下角的“○”标志熄灭后才可读数,称量过程中被称物必须轻拿轻放,并确保不使天平超载,以免损坏天平的传感器。 ◎清零或去皮 清零:当天平空载时,如显示不在零状态,可按<去皮>键,使天平显示零状态。此时才可进行正常称量。

分析天平使用说明书

TG-328分析天平使用说明书 一、分析天平结构及作用原理： 1.该分析天平，是属于双盘等臂式，横梁采用铜镍合金制成，上面装有玛瑙刀三把，中间为固定的支点刀，两边可调整的承重刀。 好仪器，好资料，尽在沧州建仪（https://www.sodocs.net/doc/9515517876.html,）。欢迎查询。 打造中国建仪销售第一品牌，树立沧州产品全新形象 2.支点刀位于支点刀垫上，支点刀垫固定在天平立柱上端。 3.横梁停动装置为双层折翼式，在天平开启时，横梁上的承重刀必须比支点刀先接角触，为了避免刀锋损坏和保证横梁位置的再现性，开启天平求轻稳，避免冲击，摇晃。 4.横梁的左右两端悬挂承重挂钩，左承重挂钩上装有砝码承重架，该二零碎件分别挂在小刀刃上，另有秤盘各一件分别挂在承重挂钩上。 5.整个天平固定在大理石的基座板上，底板前下部装有二只可供调整水平位置的螺旋脚，后面装有一只固定脚，天平木框前面有一扇可供启闭及随意停止在上下位置的玻璃门，右侧有一扇玻璃移门。 6.秤盘上节中间的阻尼装置，是用铝合金板制成，固定在中柱上。是利用空气阻力来减少横梁的摆动时间，达到静止迅速，从而提高工作效率。

7.光学报影装置，固定在底板上前方，可直接读出0.1-10毫克以内的重量值。 8.天平外框左侧装有机械加码装置，通过三档增减砝码的指示旋钮来变换自10毫克-199.99克砝码以内所需重量值。 二、分析天平主要技术指标： 规格型号技术参数：秤盘尺寸 TG328A200g/0.1mg80mm TG328B200g/0.1mg80mm1 TG628A200g/1mg80mm 三、分析天平性能特点： 1.TG系列双盘机械天平，采用空气阻尼，光电读数，具有称量准确，读数简便，价格实惠。 2.专供实验室，学校，工矿等作精密称量分析用。 四、天平的安装方法： a．安装前的准备工作安装前的准备工作安装前的准备工作安装前的准备工作 1.安装选择：天平必须放在牢固的台上，不准有震动，气流存在，室内气温要求干燥明亮，温度最好保持在20℃±2℃左右，避免阳光晒射单面受热和气温潮湿，反之影响天平的灵敏度和正确性。

外阴白色病变的症状表现有哪些

外阴白色病变的症状表现有哪些 外阴白色病变是慢性外阴的营养不良。属于营养不良的一种。而这也有分为好几个类型，混合型、增生型和硬化苔藓型等等都是外阴白色病变的类型。 外阴奇痒为主要症状，搔痒时间从发病到治疗有2～3月之内，也有达20 年之久，搔痒剧烈程度不分季节与昼夜，如伴有滴虫性或霉菌性阴道炎，分泌物会更多，局部烧灼感，刺痛与搔痒所致的皮肤粘膜破损或感染有关，局部有不同程度的皮肤粘膜色素减退，常有水肿，皲裂及散在的表浅溃疡。 一、增生型营养不良 一般发生在30～60岁的妇女，主要症状为外阴奇痒难忍，抓伤后疼痛加剧，病变范围不一，主要波及大阴唇，阴唇间沟，阴蒂包皮和后联合处，多呈对称性，病变皮肤增厚似皮革，隆起有皱襞，或有鳞屑，湿疹样改变，表面颜色多暗红或粉红，夹杂有界限清晰的白色斑块，一般无萎缩或粘连。 二、硬化苔藓型营养不良 可见于任何年龄，多见于40岁左右妇女，主要症状为病变区发痒，但一般远较增生型病变为轻，晚期出现性交困难，病变累及外阴皮肤，粘膜和肛周围皮肤，除皮肤或粘膜变白，变薄，干燥易皲裂外，并失去弹性，阴蒂多萎缩，且与包皮粘连，小阴唇平坦消失，晚期皮肤菲薄皱缩似卷烟纸，阴道口挛缩狭窄，仅容指尖。 幼女患此病多在小便或大便后感外阴及肛周不适，外阴及肛周区出现锁孔状珠黄色花斑样或白色病损，一般至青春期时，病变多自行消失。 三、混合型营养不良 主要表现为菲薄的外阴发白区的邻近部位，或在其范围内伴有局灶性皮肤增厚或隆起。 四、增生型或混合型伴上皮非典型增生 一般认为在增生型及混合型病变中，仅5、10例可出现非典型增生，且此非典型增生仅限于增生的上皮细胞部分。非典型增生多无特殊临床表现，局部组织活体组织检查为唯一的诊断方法。但如外阴局部出现溃疡。或界限清楚的白色隆起时，在该处活检发现非典型增生，其癌变的可能性较大。

精神分裂症的发病原因是什么

精神分裂症的发病原因是什么 精神分裂症是一种精神病，对于我们的影响是很大的，如果不幸患上就要及时做好治疗，不然后果会很严重，无法进行正常的工作和生活，是一件很尴尬的事情。因此为了避免患上这样的疾病，我们就要做好预防，今天我们就请广州协佳的专家张可斌来介绍一下精神分裂症的发病原因。 精神分裂症是严重影响人们身体健康的一种疾病，这种疾病会让我们整体看起来不正常，会出现胡言乱语的情况，甚至还会出现幻想幻听，可见精神分裂症这种病的危害程度。 (1)精神刺激：人的心理与社会因素密切相关，个人与社会环境不相适应，就产生了精神刺激，精神刺激导致大脑功能紊乱，出现精神障碍。不管是令人愉快的良性刺激，还是使人痛苦的恶性刺激，超过一定的限度都会对人的心理造成影响。 (2)遗传因素：精神病中如精神分裂症、情感性精神障碍，家族中精神病的患病率明显高于一般普通人群，而且血缘关系愈近，发病机会愈高。此外，精神发育迟滞、癫痫性精神障碍的遗传性在发病因素中也占相当的比重。这也是精神病的病因之一。 (3)自身：在同样的环境中，承受同样的精神刺激，那些心理素质差、对精神刺激耐受力低的人易发病。通常情况下，性格内向、心胸狭窄、过分自尊的人，不与人交往、孤僻懒散的人受挫折后容易出现精神异常。 (4)躯体因素：感染、中毒、颅脑外伤、肿瘤、内分泌、代谢及营养障碍等均可导致精神障碍，。但应注意，精神障碍伴有的躯体因素，并不完全与精神症状直接相关，有些是由躯体因素直接引起的，有些则是以躯体因素只作为一种诱因而存在。 孕期感染。如果在怀孕期间，孕妇感染了某种病毒，病毒也传染给了胎儿的话，那么，胎儿出生长大后患上精神分裂症的可能性是极其的大。所以怀孕中的女性朋友要注意卫生，尽量不要接触病毒源。 上述就是关于精神分裂症的发病原因，想必大家都已经知道了吧。患上精神分裂症之后，大家也不必过于伤心，现在我国的医疗水平是足以让大家快速恢复过来的，所以说一定要保持良好的情绪。

电子精密天平秤的使用方法及注意事项(正式版)

电子精密天平秤的使用方法及注意事项 刘维彬电子精密天平秤是定量分析工作中不可缺少的重要仪器，充分了解仪器性能及熟练掌握其使用方法，是获得可靠分析结果的保证。精密天平的种类很多，有普通精密天平、半自动/全自动加码电光投影阻尼精密天平及电子精密天平等。下面就电子精密天平的使用方法及注意事项做一介绍。 操作方法: 1．检查并调整天平至水平位置。 2．事先检查电源电压是否匹配（必要时配置稳压器），按仪器要求通电预热至所需时间。 3．预热足够时间后打开天平开关，天平则自动进行灵敏度及零点调节。待稳定标志显示后，可进行正式称量。 4．称量时将洁净称量瓶或称量纸置于称盘上，关上侧门，轻按一下去皮键，天平将自动校对零点，然后逐渐加入待称物质，直到所需重量为止。 5．称量结束应及时除去称量瓶（纸），关上侧门，切断电源，并做好使用情况登记。 注意事项: 1.天平应放置在牢固平稳水泥台或木台上，室内要求清洁、干燥及较恒定的温度，同时应避免光线直接照射到天平上。 2.称量时应从侧门取放物质，读数时应关闭箱门以免空气流动引起天平摆动。前门仅在检修或清除残留物质时使用。 3.电子精密天平若长时间不使用，则应定时通电预热，每周一次，每次预热

2h，以确保仪器始终处于良好使用状态。 4.天平箱内应放置吸潮剂(如硅胶)，当吸潮剂吸水变色，应立即高温烘烤更换，以确保吸湿性能。 5.挥发性、腐蚀性、强酸强碱类物质应盛于带盖称量瓶内称量，防止腐蚀天平。 6.称量重量不得过天平的最大载荷。 7.经常对电子天平进行自校或定期外校，保证其处于最佳状态。 8.天平发生故障，不得擅自修理，应立即报告测试中心质量负责人。 9.天平放妥后不宜经常搬动。必须搬动时，移动天平位置后，应由市计量部门校正计量合格后，方可使用。

外阴白色病变的检查诊断方法是什么

外阴白色病变的检查诊断方法是什么 外阴奇痒是外阴白色病变的主要症状，搔痒时间从发病到治疗有2～3月之内，也有达20年之久，搔痒剧烈程度不分季节与昼夜。专家提示，一旦发现自己有类似于外阴白色病变的这种，应立即到医院进行确诊。早期的诊断及治疗对我们早日恢复健康并且尤为重要。 外阴白色病变的检查： 多点活检送病理检查，确定病变性质，排除早期癌变，活检应在有皲裂，溃疡，隆起，硬结或粗糙处进行，为做到取材适当，可先用1%甲苯胺蓝(toluidine blue)涂病变区，待白干后，再用1%醋酸液擦洗脱色，凡不脱色区表示该处有裸核存在，提示在该处活检，发现非典型增生或甚至癌变的可能性较大，如局部破损区太广，应先治疗数日，待皮损大部愈合后，再选择活检部位以提高诊断准确率。 外阴白色病变的诊断： 1、症状判断：外阴白斑一般根据症状就可以判断，比如，外阴局部粘 膜发白，瘙痒、粗糙、脱屑等现象的出现，都会诊断为外阴白斑，当然，外阴白斑有很多的类型，如果外阴白斑属于增生型，也就是说局部的皮肤粘膜增厚了，弹性变差了，而且也出现了相应的溃疡等不适症状。这是主要的外阴白斑的诊断方法。 2、细胞活检：有时外阴白斑的诊断需要进一步的做细胞活检，观察有 没有癌细胞，以便于确诊。活检病理检查确定病变性质，排除早期癌变。活检应在有皲裂溃疡、隆起、硬结或粗糙处进行为做到取材适当，外阴白斑的诊断方法可先用1%甲苯胺蓝涂病变区，待白干后再用1%醋酸液擦洗脱色。凡不脱色区表示该处有裸核存在，提示在该处活检发现非典型增生或甚至癌变的可能性较大。如局部破损区太广，应先治疗数日待皮损大部愈合后，再选择活检部位以提高诊断准确率。 3、病理诊断依据：除了解疾病的主要临床症状外，还应对疾病的发病 机理有一定的认识，因为导致外阴白斑皮肤瘙痒及色素的减退或脱色的疾病有很多种，不只是外阴白斑一种，它们的表现虽有些不同，但用肉眼不易区别开来，所以当遇到外阴有病损不典型或慢性皲裂、局限性增厚、溃破等症状的患者时，必须依靠活组织病理检查确诊。

精神分裂症的病因是什么

精神分裂症的病因是什么 精神分裂症是一种精神方面的疾病，青壮年发生的概率高，一般 在16～40岁间，没有正常器官的疾病出现，为一种功能性精神病。 精神分裂症大部分的患者是由于在日常的生活和工作当中受到的压力 过大，而患者没有一个良好的疏导的方式所导致。患者在出现该情况 不仅影响本人的正常社会生活，且对家庭和社会也造成很严重的影响。 精神分裂症常见的致病因素： 1、环境因素：工作环境比如经济水平低低收入人群、无职业的人群中，精神分裂症的患病率明显高于经济水平高的职业人群的患病率。还有实际的生活环境生活中的不如意不开心也会诱发该病。 2、心理因素：生活工作中的不开心不满意，导致情绪上的失控，心里长期受到压抑没有办法和没有正确的途径去发泄，如恋爱失败， 婚姻破裂，学习、工作中不愉快都会成为本病的原因。 3、遗传因素：家族中长辈或者亲属中曾经有过这样的病人，后代会出现精神分裂症的机会比正常人要高。 4、精神影响：人的心里与社会要各个方面都有着不可缺少的联系，对社会环境不适应，自己无法融入到社会中去，自己与社会环境不相

适应，精神和心情就会受到一定的影响，大脑控制着人的精神世界， 有可能促发精神分裂症。 5、身体方面：细菌感染、出现中毒情况、大脑外伤、肿瘤、身体的代谢及营养不良等均可能导致使精神分裂症，身体受到外界环境的 影响受到一定程度的伤害，心里受到打击，无法承受伤害造成的痛苦，可能会出现精神的问题。 对于精神分裂症一定要配合治疗，接受全面正确的治疗，最好的 疗法就是中医疗法加心理疗法。早发现并及时治疗并且科学合理的治疗，不要相信迷信，要去正规的医院接受合理的治疗，接受正确的治 疗按照医生的要求对症下药，配合医生和家人，给病人创造一个良好 的治疗环境，对于该病的康复和痊愈会起到意想不到的效果。

卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规范(试行)

卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规 范(试行)》的通知 【法规类别】采供血机构和血液管理 【发文字号】卫办医政发[2009]189号 【失效依据】国家卫生计生委办公厅关于印发造血干细胞移植技术管理规范(2017年版)等15个“限制临床应用”医疗技术管理规范和质量控制指标的通知 【发布部门】卫生部(已撤销) 【发布日期】2009.11.13 【实施日期】2009.11.13 【时效性】失效 【效力级别】部门规范性文件 卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规范（试行）》的通知 （卫办医政发〔2009〕189号） 各省、自治区、直辖市卫生厅局，新疆生产建设兵团卫生局： 为贯彻落实《医疗技术临床应用管理办法》，做好脐带血造血干细胞治疗技术审核和临床应用管理，保障医疗质量和医疗安全，我部组织制定了《脐带血造血干细胞治疗技术管理规范（试行）》。现印发给你们，请遵照执行。 二〇〇九年十一月十三日

脐带血造血干细胞 治疗技术管理规范（试行） 为规范脐带血造血干细胞治疗技术的临床应用，保证医疗质量和医疗安全，制定本规范。本规范为技术审核机构对医疗机构申请临床应用脐带血造血干细胞治疗技术进行技术审核的依据，是医疗机构及其医师开展脐带血造血干细胞治疗技术的最低要求。 本治疗技术管理规范适用于脐带血造血干细胞移植技术。 一、医疗机构基本要求 （一）开展脐带血造血干细胞治疗技术的医疗机构应当与其功能、任务相适应，有合法脐带血造血干细胞来源。 （二）三级综合医院、血液病医院或儿童医院，具有卫生行政部门核准登记的血液内科或儿科专业诊疗科目。 1.三级综合医院血液内科开展成人脐带血造血干细胞治疗技术的，还应当具备以下条件： （1）近3年内独立开展脐带血造血干细胞和（或）同种异基因造血干细胞移植15例以上。 （2）有4张床位以上的百级层流病房，配备病人呼叫系统、心电监护仪、电动吸引器、供氧设施。 （3）开展儿童脐带血造血干细胞治疗技术的，还应至少有1名具有副主任医师以上专业技术职务任职资格的儿科医师。 2.三级综合医院儿科开展儿童脐带血造血干细胞治疗技术的，还应当具备以下条件：

妇科良方_第二章 外阴白色病变及外阴瘙痒症方

外阴白色病变方 外阴白色病变包括由于各种因素影响所致之外阴部皮肤及粘膜的不同程度变白及（或）粗糙、萎缩的状态。1975年国际外阴病研究会改称“外阴白斑”为“慢性外阴营养不良”，并根据其组织病理变化的不同而分为增生型营养不良（包括无非典型增生、非典型增生两类）、硬化苔藓型营养不良、混合型营养不良（亦包括无非典型增生、非典型增生两类）三种类型。 外阴瘙痒为本病主要症状，搔抓可造成局部破溃与感染而出现烧灼感、疼痛、流液。增生型皮肤增厚似皮革，粗糙，或有鳞屑、湿疹样改变，表面颜色多暗红或粉红，夹杂有界限清晰的白色斑块；硬化苔藓型皮肤或粘膜变白变薄，甚至裂开，阴道口萎缩者可致性交痛；混合型是在外阴萎缩的基础上又有增厚的斑块或疣状增生灶。各型均以病检为主要诊断依据。 西医治疗可内服维生素A、B2、B6、鱼甘油等；局部用药以止痒、消炎、润肤和改善局部营养为目的，用药应依据病理类型。如增生型可用肤轻松、氢化可的松等软膏涂擦；硬化苔藓型给予1～2%丙酸睾丸酮鱼甘油软膏；混合型则用丙酸睾素软膏与可的松软膏合用或先后使用。氦氖激光照射对外阴硬萎有一定疗效。 本病一般属中医“阴痒”、“阴蚀”等病证范畴。其发病机理，常因肝肾阴血不足，不能滋养阴器，血虚生风化燥，而致阴部奇痒难忍；或因脾气亏虚，一则气虚血少，不能滋养阴部，脾虚又可生湿，流注于下，形成气血不足而湿浊停滞的虚实夹杂局面；或因湿热内盛，热蕴阴部肌肤而致阴痒阴肿；久病入络，气血运行不畅而成瘀滞，与湿浊相互胶结，而见苔癣、奇痒、干裂诸候，且经久难愈。治疗当结合病因病机，或滋养肝肾，养血熄风止痒；或清热利湿，祛风止痒；或活血化瘀软坚；或健脾祛湿杀虫等。 本节选介消斑膏丸方、蛇桑坐浴方等治疗外阴白色病变验方共13首。 1.消斑膏丸方 【药物组成】①外用消斑膏：A、消斑膏1号：补骨脂、仙灵脾各9g，生狼毒、白藓皮各6g，蛇床子、徐长卿各15g，薄荷1g。用其酒精渗出液，回收浓缩后，制成霜剂；B、消斑膏2号：即1号去薄荷，加0.1%强的松粉拌匀而成（制法同上）；C、消斑膏3号：即1号去狼毒、薄荷，加白花蛇舌草、一枝黄花各30g（制法同上）；D、消斑膏4号：即1号去薄荷加丙酸睾丸酮做成0.2%的霜剂（制法同上）。 ②内服消斑丸：黄芪、丹参、当归、菟丝子、仙灵脾、白蒺藜各3g，白藓皮4g，木香 0.2g。共研细末，做成蜜丸或煎成汤剂（以上为1日量）。 【治疗方法】①外用消斑膏：1号适用于外阴无破溃或皲裂者；2号适用于对1号有过敏反应但无癌变可能者；3号适用于局部有感染、破溃或皲裂，或有霉菌，滴虫感染者；4号适用于外阴萎缩或有粘连者。 以上软膏均每日外涂阴部1～2次。 ②内服消斑丸：每日2次，每次10g。所有病例均服此丸。 膏剂外用和丸剂内服，均以3个月为1疗程。一般用药1～3个疗程。

精神分裂症应该怎么治疗

精神分裂症应该怎么治疗 1、坚持服药治疗 服药治疗是最有效的预防复发措施临床大量统计资料表明，大多数精神分裂症的复发与自行停药有关。坚持维持量服药的病人复发率为40%。而没坚持维持量服药者复发率高达80%。因此，病人和家属要高度重视维持治疗。 2、及时发现复发的先兆，及时处理 精神分裂症的复发是有先兆的，只要及时发现，及时调整药物和剂量，一般都能防止复发，常见的复发先兆为：病人无原因出现睡眠不好、懒散、不愿起床、发呆发愣、情绪不稳、无故发脾气、烦躁易怒、胡思乱想、说话离谱，或病中的想法又露头等。这时就应该及时就医，调整治疗病情波动时的及时处理可免于疾病的复发。 3、坚持定期门诊复查 一定要坚持定期到门诊复查，使医生连续地、动态地了解病情，使病人经常处于精神科医生的医疗监护之下，及时根据病情变化调整药量。通过复查也可使端正人及时得到咨询和心理治疗解除病人在生活、工作和药物治疗中的各种困惑，这对预防精神分裂症的复发也起着重要作用。 4、减少诱发因素 家属及周围人要充分认识到精神分裂症病人病后精神状态的薄弱性，帮助安排好日常的生活、工作、学习。经常与病人谈心，帮助病人正确对待疾病，正确对待现实生活，帮助病人提高心理承受能力，学会对待应激事件的方法，鼓励病人增强信心，指导病人充实生活，使病人在没有心理压力和精神困扰的环境中生活。 首先是性格上的改变，塬本活泼开朗爱玩的人，突然变得沉默寡言，独自发呆，不与人交往，爱干净的人也变的不注意卫生、生活

懒散、纪律松弛、做事注意力不集中，总是和患病之前的性格完全 相悖。 再者就是语言表达异常，在谈话中说一些无关的谈话内容，使人无法理解。连最简单的话语都无法准确称述，与之谈话完全感觉不 到重心。 第三个就是行为的异常，行为怪异让人无法理解，喜欢独处、不适意的追逐异性，不知廉耻，自语自笑、生活懒散、时常发呆、蒙 头大睡、四处乱跑，夜不归宿等。 还有情感上的变化，失去了以往的热情，开始变的冷淡、对亲人不关心、和友人疏远，对周围事情不感兴趣，一点消失都可大动干戈。 最后就是敏感多疑，对任何事情比较敏感，精神分裂症患者，总认为有人针对自己。甚至有时认为有人要害自己，从而不吃不喝。 但是也有的会出现难以入眠、容易被惊醒或睡眠不深，整晚做恶梦或者长睡不醒的现象。这些都有可能是患上了精神分裂症。 1.加强心理护理 心理护理是家庭护理中的重要方面，由于社会上普遍存在对精神病人的歧视和偏见，给病人造成很大的精神压力，常表现为自卑、 抑郁、绝望等，有的病人会因无法承受压力而自杀。家属应多给予 些爱心和理解，满足其心理需求，尽力消除病人的悲观情绪。病人 生活在家庭中，与亲人朝夕相处，接触密切，家属便于对病人的情感、行为进行细致的观察，病人的思想活动也易于向家属暴露。家 属应掌握适当的心理护理方法，随时对病人进行启发与帮助，启发 病人对病态的认识，帮助他们树立自信，以积极的心态好地回归社会。 2.重视服药的依从性 精神分裂症病人家庭护理的关键就在于要让病人按时按量吃药维持治疗。如果不按时服药，精神病尤其是精神分裂症的复发率很高。精神病人在医院经过一系统的治疗痊愈后，一般需要维持2~3年的

卫生部关于印发《脐带血造血干细胞库设置管理规范(试行)》的通知

卫生部关于印发《脐带血造血干细胞库设置管理规范(试行)》的通知 发文机关：卫生部(已撤销) 发布日期： 2001.01.09 生效日期： 2001.02.01 时效性：现行有效 文号：卫医发(2001)10号 各省、自治区、直辖市卫生厅局： 为贯彻实施《脐带血造血干细胞库管理办法（试行）》，保证脐带血临床使用的安全、有效，我部制定了《脐带血造血干细胞库设计管理规范（试行）》。现印发给你们，请遵照执行。 附件：《脐带血造血干细胞库设置管理规范（试行）》 二○○一年一月九日 附件： 脐带血造血干细胞库设置管理规范（试行） 脐带血造血干细胞库的设置管理必须符合本规范的规定。 一、机构设置 （一）脐带血造血干细胞库（以下简称脐带血库）实行主任负责制。 （二）部门设置 脐带血库设置业务科室至少应涵盖以下功能：脐带血采运、处理、细胞培养、组织配型、微生物、深低温冻存及融化、脐带血档案资料及独立的质量管理部分。 二、人员要求

（一）脐带血库主任应具有医学高级职称。脐带血库可设副主任，应具有临床医学或生物学中、高级职称。 （二）各部门负责人员要求 1．负责脐带血采运的人员应具有医学中专以上学历，2年以上医护工作经验，经专业培训并考核合格者。 2．负责细胞培养、组织配型、微生物、深低温冻存及融化、质量保证的人员应具有医学或相关学科本科以上学历，4年以上专业工作经历，并具有丰富的相关专业技术经验和较高的业务指导水平。 3．负责档案资料的人员应具相关专业中专以上学历，具有计算机基础知识和一定的医学知识，熟悉脐带血库的生产全过程。 4．负责其它业务工作的人员应具有相关专业大学以上学历，熟悉相关业务，具有2年以上相关专业工作经验。 （三）各部门工作人员任职条件 1．脐带血采集人员为经过严格专业培训的护士或助产士职称以上卫生专业技术人员并经考核合格者。 2．脐带血处理技术人员为医学、生物学专业大专以上学历，经培训并考核合格者。 3．脐带血冻存技术人员为大专以上学历、经培训并考核合格者。 4．脐带血库实验室技术人员为相关专业大专以上学历，经培训并考核合格者。 三、建筑和设施 （一）脐带血库建筑选址应保证周围无污染源。 （二）脐带血库建筑设施应符合国家有关规定，总体结构与装修要符合抗震、消防、安全、合理、坚固的要求。 （三）脐带血库要布局合理，建筑面积应达到至少能够储存一万份脐带血的空间；并具有脐带血处理洁净室、深低温冻存室、组织配型室、细菌检测室、病毒检测室、造血干/祖细胞检测室、流式细胞仪室、档案资料室、收/发血室、消毒室等专业房。 （四）业务工作区域应与行政区域分开。

精神分裂症患者在怎样的情况下会自杀

精神分裂症患者在怎样的情况下会自杀 精神分裂症是最常见的一种精神病。早期主要表现为性格改变，如不理采亲人、不讲卫生、对镜子独笑等。病情进一步发展，即表现为思维紊乱，病人的思考过程缺乏逻辑性和连贯性，言语零乱、词不达意。精神分裂症患者随时有可能出现危险行为，这主要是指伤人毁物、自伤自杀和忽然出走。这些危险行为是受特定的精神症状支配的.那么精神分裂症患者在什么情况下会自杀呢？ 被害妄想：这是所有精神病人最常见的症状之一，多数病人采取忍耐、逃避的态度，少数病人也会“先下手为强”，对他的“假想敌”主动攻击。对此，最重要的是弄清病人的妄想对象，即：病人以为是谁要害他。假如病人的妄想对象是某个家里人，则应尽量让这位家属阔别病人，至少不要让他与病人单独在一起。 抑郁情绪：精神分裂症病人在疾病的不同时期，可能出现情绪低落，甚至悲观厌世。特别需要留意的是，有相当一部分自杀成功的病人，是在疾病的恢复期实施自杀行为的。病人在精神病症状消除以后，因自己的病背上了沉重的思想包袱，不能正确对待升学、就业、婚姻等现实问题，感到走投无路，因此选择了轻生。对此，家属一定要防患于未然，要尽早发现病人的心理困扰，及时疏导。 对已经明确表示出自杀观念的病人，家属既不要惊慌失措，也不要躲躲闪闪，要主动与病人讨论自杀的利弊，帮助病人全面、客观地评估现实中碰到的各种困难，找出切实可行的解决办法。 另外，这种病人在自杀之前，是经过周密考虑，并且做了充分预备的，例如写遗书、收拾旧物、向家人离别、选择自杀时间、预备自杀工具等。这类病人的自杀方式也是比较温顺的，多数是服药自杀。因此，他需要一定的时间来积攒足足数目的药物，这时就能看出由家属保管药品的重要性了。只要家属密切观察病人的情绪变化，是不难早期发现病人的自杀企图的。 药源性焦虑：抗精神病药的副作用之一是可能引起病人莫名的焦躁不安、手足无措，并伴有心慌、出汗、恐惧等。这些表现多是发作性的，多数发生在下午到傍晚时分，也有的病人在打长效针以后的2?3天内出现上述表现。这种时间上的规律性，有助于家属判定病人的焦虑情绪是否由于药物所致。病人急于摆脱这种强烈的痛苦，会出现冲动伤人或自伤，这些行为只是为了发泄和解脱，并不以死为终极目的。家属可以在病人发作时，给他服用小剂量的安定类药物，或者在医生的指导下，调整抗精神病药的剂量或品种，这样就可以有效地控制病人的焦虑发作。 极度兴奋：病人的精神症状表现为严重的思维紊乱、言语杂乱无章、行为缺乏目的性，这类病人也可能出现自伤或伤人毁物。由于病人的兴奋躁动是持续性的，家属有充分的思想预备，一般比较轻易防范。家属要保管好家里的刀、剪、火、煤气等危险物品，但最根本的办法，是使用大剂量的、具有强烈镇静作用的药物来控制病人的兴奋。假如在家里护理病人确有困难，则可以强制病人住院治