Genetic basis and variable phenotypic expression of Kallmann syndrome: towards a unifying theory.

Idiopathic hypogonadotropic hypogonadism (IHH) is defined by absent or incomplete puberty and characterised biochemically by low levels of sex steroids, with low or inappropriately normal gonadotropin hormones. IHH is frequently accompanied by non-reproductive abnormalities, most commonly anosmia, which is present in 50-60% of cases and defines Kallmann syndrome. The understanding of IHH has undergone rapid evolution, both in respect of genetics and breadth of phenotype. Once considered in monogenic Mendelian terms, it is now more coherently understood as a complex genetic condition. Oligogenic and complex genetic-environmental interactions have now been identified, with physiological and environmental factors interacting in genetically susceptible individuals to alter the clinical course and phenotype. These potentially link IHH to ancient evolutionary pressures on the ancestral human genome.

Performance anxiety : cardiorespiratory activity in high- and low-anxious professional music students in a performance situation

Questionnaire studies indicate that high-anxious musicians may suffer from hyperventilation symptoms before and/or during performance. Reported symptoms include amongst others shortness of breath, fast or deep breathing, dizziness and thumping heart. A self-report study by Widmer, Conway, Cohen and Davies (1997) shows that up to seventy percent of the tested highly anxious musicians are hyperventilators during performance. However, no study has yet tested if these self-reported symptoms reflect actual cardiorespiratory changes just before and during performance. Disturbances in breathing patterns and hyperventilation may negatively affect the performance quality in stressful performance situations. The main goal of this study is to determine if music performance anxiety is manifest physiologically in specific correlates of cardiorespiratory activity. We studied 74 professional music students of Swiss Music Universities divided into two groups (high- and lowanxious) based on their self-reported performance anxiety (State-Trait Anxiety Inventory by Spielberger). The students were tested in three distinct situations: baseline, performance without audience, performance with audience. We measured a) breathing patterns, end-tidal carbon dioxide, which is a good non-invasive estimator for hyperventilation, and cardiac activation and b) self-perceived emotions and self-perceived physiological activation. Analyses of heart rate, respiratory rate, self-perceived palpitations, self-perceived shortness of breath and self-perceived anxiety for the 15 most and the 15 least anxious musicians show that high-anxious and low-anxious music students have a comparable physiological activation during the different measurement periods. However, highanxious music students feel significantly more anxious and perceive significantly stronger palpitations and significantly stronger shortness of breath just before and during a public performance. The results indicate that low- and high-anxious music students a) do not differ in the considered physiological responses and b) differ in the considered self-perceived physiological symptoms and the selfreported anxiety before and/or during a public performance.

Conditional manipulation of sex ratios by ant workers: A test of kin selection theory

Variable queen mating frequencies provide a unique opportunity to study the resolution of worker-queen conflict over sex ratio in social Hymenoptera, because the conflict is maximal in colonies headed by a singly mated queen and is weak or nonexistent in colonies headed by a multiply mated queen. In the wood ant Formica exsecta, workers in colonies with a singly mated queen, but not those in colonies with a multiply mated queen, altered the sex ratio of queen-laid eggs by eliminating males to preferentially raise queens. By this conditional response to queen mating frequency, workers enhance their inclusive fitness.

Instrumental leadership: An extension of the Full-Range Leadership Theory

From a theoretical perspective, an extension to the Full Range leadership Theory (FRLT) seems needed. In this paper, we explain why instrumental leadership--a class of leadership includes leader behaviors focusing on task and strategic aspects that are neither values nor exchange oriented--can fulfill this extension. Instrument leadership is composed of four factors: environmental monitoring, strategy formulation and implementation, path-goal facilitation and outcome monitoring; these aspects of leadership are currently not included in any of the FRLT's nine leadership scales (as measured by the MLQ--Multifactor Leadership Questionnaire). We present results from two empirical studies using very large samples from a wide array of countries (N > 3,000) to examine the factorial, discriminant and criterion-related validity of the instrumental leadership scales. We find support for a four-factor instrumental leadership model, which explains incremental variance in leader outcomes in over and above transactional and transformational leadership.

P value and the theory of hypothesis testing: an explanation for new researchers.

In the 1920s, Ronald Fisher developed the theory behind the p value and Jerzy Neyman and Egon Pearson developed the theory of hypothesis testing. These distinct theories have provided researchers important quantitative tools to confirm or refute their hypotheses. The p value is the probability to obtain an effect equal to or more extreme than the one observed presuming the null hypothesis of no effect is true; it gives researchers a measure of the strength of evidence against the null hypothesis. As commonly used, investigators will select a threshold p value below which they will reject the null hypothesis. The theory of hypothesis testing allows researchers to reject a null hypothesis in favor of an alternative hypothesis of some effect. As commonly used, investigators choose Type I error (rejecting the null hypothesis when it is true) and Type II error (accepting the null hypothesis when it is false) levels and determine some critical region. If the test statistic falls into that critical region, the null hypothesis is rejected in favor of the alternative hypothesis. Despite similarities between the two, the p value and the theory of hypothesis testing are different theories that often are misunderstood and confused, leading researchers to improper conclusions. Perhaps the most common misconception is to consider the p value as the probability that the null hypothesis is true rather than the probability of obtaining the difference observed, or one that is more extreme, considering the null is true. Another concern is the risk that an important proportion of statistically significant results are falsely significant. Researchers should have a minimum understanding of these two theories so that they are better able to plan, conduct, interpret, and report scientific experiments.

Reception of Walras' theory of exchange and theory of production in Russia

This paper evaluates the reception of Léon Walras' ideas in Russia before 1920. Despite an unfavourable institutional context, Walras was read by Russian economists. On the one hand, Bortkiewicz and Winiarski, who lived outside Russia and had the opportunity to meet and correspond with Walras, were first class readers and very good ambassadors for Walras' ideas, while on the other, the economists living in Russia were more selective in their readings. They restricted themselves to Walras' Elements of Pure Economics, in particular, its theory of exchange, while ignoring its theory of production. We introduce a cultural argument to explain their selective reading. JEL classification numbers: B 13, B 19.

Aufftrittsangst : kardiorespiratorische Aktivität bei ängstlichen und nichtängstlichen Musikstudenten in einer Auftrittssituation = Performance anxiety : cardiorespiratory activity in high- and low-anxious professional music students in a performance situation

Fragebogenstudien haben gezeigt, dass ängstliche Musiker vor und/oder während eines Auftritts möglicherweise unter Hyperventilationssymptomen leiden. Berichtete Symptome beinhalten Kurzatmigkeit, schnelles oder tiefes Einatmen, Schwindelgefühl und Herzklopfen. Bisher hat jedoch noch keine Studie getestet, ob diese selbstberichteten Symptome tatsächlich kardiorespiratorische Veränderungen widerspiegeln. Das Hauptziel dieser Studie ist es, zu bestimmen, ob sich Auftrittsangst bei Musikern physiologisch über kardiorespiratorische Muster äußert. Wir haben insgesamt 74 Musikstudenten von Schweizer Musikhochschulen getestet. Diese Studenten wurden aufgrund ihrer selbstberichteten Auftrittsangst (STAI-S) in zwei Gruppen unterteilt: ängstliche Musiker und nichtängstliche Musiker. Die Studenten wurden in drei unterschiedlichen Situationen getestet: Ausgangszustand, Auftritt ohne Publikum, Auftritt mit Publikum. Wir haben folgende Parameter gemessen: a) kardiorespiratorische Muster und endexpiratorisches CO2, welches eine gute nichtinvasive Schätzung des Hyperventilationsgrades liefert und b) subjektiv wahrgenommene Emotionen und subjektiv wahrgenommene physiologische Aktivität. Das Poster zeigt die ersten Resultate der 15 ängstlichsten und der 15 am wenigsten ängstlichen Musiker. Das Hauptinteresse gilt den folgenden Punkten: Herz- und Atemfrequenz, subjektiv wahrgenommenes Herzklopfen, subjektiv wahrgenommene Kurzatmigkeit und subjektiv wahrgenommenes Angstgefühl. Die Resultate dieser Studie zeigen erstens, dass ängstliche und nichtängstliche Musikstudenten zu den verschiedenen Messzeitpunkten eine vergleichbare physiologische Aktivität aufweisen und zweitens, dass ängstliche Musikstudenten ein signifikant höheres Angstgefühl haben und signifikant mehr Herzklopfen und Kurzatmigkeit wahrnehmen vor und/oder während eines Auftritts mit Publikum. Dies deutet darauf hin, dass sich ängstliche und nichtängstliche Musikstudenten a) bezüglich der subjektiv wahrgenommenen physiologischen Symptome und des selbst berichteten Angstgefühls vor und/oder während eines öffentlichen Auftritts unterscheiden und sich b) bezüglich der untersuchten physiologischen Reaktionen nicht unterscheiden.