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Univariate Tests (univariate + test)

Distribution by Scientific Domains

Business, Economics, Finance and Accounting	50%

Selected Abstracts

Ecological niche specialization inferred from morphological variation and otolith strontium of Arctic charr Salvelinus alpinus L. found within open lake systems of southern Baffin Island, Nunavut, Canada

JOURNAL OF FISH BIOLOGY, Issue 6 2009
T. N. Loewen
The presence of two morphotypes of Arctic charr Salvelinus alpinus was confirmed via morphological variation and otolith strontium (Sr) within three open-lake systems of southern Baffin Island, Nunavut, Canada: Qinngu (LH001), Iqalugaarjuit Lake (PG082) and Qasigiat (PG015). Analysis of otolith Sr indicates that a component of each S. alpinus population within lakes LH001 and PG082 is migratory (large,maturing S. alpinus), whereas another component is lake-resident (small,maturing S. alpinus). Alternatively, small and large maturing S. alpinus may both inhabit tidal habitats during their lifetime in lake PG015. Three morphological characters were identified by principal factor analysis (PFA) as characters that were different between maturity groups for all lakes studied: eye diameter, pectoral fin length and pelvic fin length. As well, upper jaw length (LH001 and PG082) and fork depth (PG015) were identified in PFA as traits that differed between morphs. Univariate tests of morphological characters identified by PFA demonstrated maturity group differences with the exception of eye diameter in Lake PG015 and upper jaw length and pelvic fin length in lake LH001. No difference was found in the MANOVA test of upper and lower gill raker number between small,maturing and undeveloped fish within all lakes studied. Clear morphological variation observed between small,maturing and undeveloped fish in all three lakes of the study suggests ecological niche separation between morphotypes. This is the first documented case of lake-resident S. alpinus use of the tidal habitat in the presence of a migratory large,maturing morphotype. [source]

Convergence in West German Regional Unemployment Rates

GERMAN ECONOMIC REVIEW, Issue 4 2007
Christian Bayer
Stochastic convergence; unemployment; structural break; unit root Abstract. Differences in regional unemployment rates are often used to describe regional economic inequality. This paper asks whether changes in regional unemployment differences in West Germany are persistent over time. Understanding the persistency of regional unemployment differences helps us to assess how effective regional policy can be. While univariate tests suggest that changes in regional unemployment differences are persistent in West Germany, more powerful panel tests lend some support to the hypothesis that regional unemployment rates converge. However, these tests reveal a moderate speed of convergence at best. Because there is a structural break following the second oil crisis, we also use tests that allow for such a break. This provides evidence for both convergence and quick adjustment to an equilibrium distribution of regional unemployment rates that is, however, subject to a structural break. [source]

On the Performance of Airlines and Airplane Manufacturers Following Aviation Disasters

CANADIAN JOURNAL OF ADMINISTRATIVE SCIENCES, Issue 1 2005
Thomas John Walker
Our study examines the impact of aviation disasters on the short- and long-term performance of airlines and airplane manufacturers. We employ a sample of 138 aviation disasters involving airplanes operated by publicly traded U.S. carriers between July 1962 and December 2003. We use event study methodology to measure the abnormal performance of airlines and airplane manufacturers to these disasters. In addition, we employ a series of univariate tests and regression analysis to determine the factors that drive the abnormal returns for the firms in our sample. We observe that airlines experience an average stock price drop of 2.8% within one trading day after the corresponding news announcement, while airplane manufacturers experience a stock price drop of only 0.8% during that time period. The magnitude of the initial price decline appears to be driven by various characteristics of both the firm and the accident itself. We observe that airlines' abnormal performance is negatively related to firm size and the number of fatalities resulting from the accident. In addition, we observe that disasters that occurred in the U.S. and disasters caused by criminal activity (in particular the 9/11 terrorist attacks) cause significantly larger stock price drops in the days following the event. Similar dependencies can be observed for airplane manufacturers. Résumé La présente étude examine l'incidence des catastrophes aériennes sur la performance à court et à long terme des compagnies aériennes et des constructeurs d'avions. Elle se sert d'un échantillon de 138 catastrophes aériennes survenues entre juillet 1962 et décembre 2003, impliquant des appareils exploités par des transporteurs aériens des États-Unis, cotés en bourse. La méthodologie de l'étude de cas est utilisée pour mesurer la performance anormale des lignes aériennes et des constructeurs d'avions, à la suite de catastrophes aériennes. L'étude essaie de déterminer les facteurs qui régissent la performance anormale des entreprises à partir d'une série de tests à une variable et de l'analyse de régression. Elle montre que le cours des actions des lignes aériennes fléchit en moyenne de 2,8% en une journée de bourse après l'annonce d'une catastrophe, tandis que le cours des actions des constructeurs d'avions n'enregistre qu'une baisse de 0,8% durant la même période. L'ampleur du déclin initial des cours semble être déterminée par diverses caractéristiques de l'entreprise ainsi que par l'accident même. La performance anormale des lignes aériennes est en relation négative avec la taille de l'entreprise et le nombre de décès résultant de l'accident. En outre, les catastrophes survenues aux États-Unis (ou dans son espace aérien) et les catastrophes résultant d'actes criminels (en particulier les attaques terroristes du 11 septembre) ont provoqué des chutes des cours beaucoup plus marquées dans les jours suivant l'événement. Les interdépendances relevées touchent également les constructeurs d'avions. [source]

Coping strategies used by hypersexual patients to defend against the painful effects of shame

CLINICAL PSYCHOLOGY AND PSYCHOTHERAPY (AN INTERNATIONAL JOURNAL OF THEORY & PRACTICE), Issue 2 2009
Rory C. Reid
This article reports the findings of a study investigating coping strategies used by hypersexual patients (n = 71), compared with a control group (n = 73), in their attempts to defend against shame. Coping strategies were measured using the Compass of Shame Scale (CoSS) and hypersexual behaviour was measured by the Hypersexual Behavior Inventory (HBI). A multivariate analysis of variance of between-group differences was significant, and examination of post hoc univariate tests revealed that the sample of hypersexual patients defended against shame with higher levels of withdrawal and higher tendencies to attack self and others when compared with the control group. The effect sizes of these differences were moderate to large. A categorical analysis of the patient group indicated that the greatest percentages of elevated shame scores were clustered on the Withdrawal and Attack Self subscales of the CoSS. Between-group differences on the Avoidance subscale of the CoSS were not significant. The results of this study are discussed as they pertain to clinical practice, and future recommendations for research are offered.,Copyright © 2009 John Wiley & Sons, Ltd. [source]