Use of the Likelihood Ratio Test on the Inverse Gaussian Distribution

In the following article, the likelihood ratio test is determined for four tests of hypotheses involving the inverse Gaussian distribution. For three of the hypotheses, the test produces the same statistic as the uniformly most powerful unbiased test.     

Interaction between adoptive mothers’ and fathers’ depressive symptoms in risk for children’s emerging problem behavior

The effect of parental depression on children's adjustment has been well documented, with exposure during early childhood particularly detrimental. Most studies that examine links between parental depression and child behavior are confounded methodologically because they focus on parents raising children who are genetically related to them. Another limitation of most prior research is a tendency to focus only on the effects of maternal depression while ignoring the influence of fathers’ depression. The purpose of this study was to examine whether infants’ exposure to both parents’ depressive symptoms, and inherited risk from birth mother internalizing symptoms, was related to school age children's externalizing and internalizing problems. Study data come from a longitudinal adoption study of 561 adoptive parents, biological mothers, and adopted children. Adoptive fathers’ depressive symptoms during infancy contributed independent variance to the prediction of children's internalizing symptoms and also moderated associations between adoptive mothers’ depressive symptoms and child externalizing symptoms.     

Dose‐Response Model of Coxiella burnetii (Q Fever)

Q fever is a zoonotic disease caused by the intracellular gram‐negative bacterium Coxiella burnetii (C. burnetii), which only multiplies within the phagolysosomal vacuoles. Q fever may manifest as acute or chronic disease. The acute form is generally not fatal and manifestes as self‐controlled febrile illness. Chronic Q fever is usually characterized by endocarditis. Many animal models, including humans, have been studied for Q fever infection through various exposure routes. The studies considered different endpoints including death for animal models and clinical signs for human infection. In this article, animal experimental data available in the open literature were fit to suitable dose‐response models using maximum likelihood estimation. Research results for tests of severe combined immunodeficient mice inoculated intraperitoneally (i.p.) with C. burnetii were best estimated with the Beta‐Poisson dose‐response model. Similar inoculation (i.p.) trial outcomes conducted on C57BL/6J mice were best fit by an exponential model, whereas those tests run on C57BL/10ScN mice were optimally represented by a Beta‐Poisson dose‐response model.     

Theory‐of‐mind during childhood: Investigating syntactic and executive contributions

Both syntax and Executive Functions (EF) are involved in Theory‐of‐Mind (ToM) but their contributory roles have mainly been studied separately. Moreover, researchers have mostly administered False Belief (FB) tasks while they may not be representative of all ToM abilities. Studies of adults give valuable information regarding whether syntax and EF are useful for ToM reasoning (i.e., Reasoning account), however, only the study of children brings direct evidence in favor of ToM emergence (i.e., Emergence account). Also, because the ToM tasks used often entail verbal and executive demands, the links observed could mostly result from such confounds (i.e., Expression account). We evaluated ToM, syntactic and EF abilities in 126 children (3‐11 y.o.) using a set of ToM tasks with minimal verbal and executive demands. Our goals were to assess (1) the hierarchical contribution of syntax and EF to ToM, (2) whether results previously obtained for FB tasks are representative of ToM in general, (3) whether the ToM‐syntax and ToM‐EF links are constant (i.e., Reasoning account) or decrease during development (i.e., Emergence accounts). Results of stepwise regression analyses showed a predominant role of syntax over EF to predict ToM abilities. The comparison of results for ToM and FB tasks showed that FB is not always representative of ToM. Finally, there was no moderating effect of age on the syntax‐ToM or EF‐ToM relations, thus suggestive of the Reasoning account rather than the Emergence account.     

Globally intensity-reweighted estimators for K- and pair correlation functions

We introduce new estimators of the inhomogeneous K-function and the pair correlation function of a spatial point process as well as the cross K-function and the cross pair correlation function of a bivariate spatial point process under the assumption of second-order intensity-reweighted stationarity. These estimators rely on a ‘global’ normalisation factor which depends on an aggregation of the intensity function, while the existing estimators depend ‘locally’ on the intensity function at the individual observed points. The advantages of our new global estimators over the existing local estimators are demonstrated by theoretical considerations and a simulation study.     

How feedback about leadership potential impacts ambition,organizational commitment,and performance

In the present research we report results from two experimental studies that examine how feedback about leadership potential impacts leadership ambition, organizational commitment, and performance. Study 1 used an experimental vignette methodology that controls for prior performance. Results show that individuals who receive feedback that they have low potential to be a future leader have lower ambition and organizational commitment relative to those who receive feedback that they have high potential to be a future leader. Study 2 provides evidence of the causal behavioral effects of feedback about leadership potential using a real task effort environment. Results show that participants informed to be unlikely future leaders display lower performance in a subsequent task than participants informed to be likely future leaders. The findings from the two studies demonstrate that information about leadership potential affects subsequent ambition to become leaders as well as performance. We discuss the implications of these findings for the importance of followership, talent management, and leadership succession.     

A general definition of influence between stochastic processes

We extend the study of weak local conditional independence (WCLI) based on a measurability condition made by (Commenges and Gégout-Petit J R Stat Soc B 71:1–18) to a larger class of processes that we call D￠{\bf {\mathcal{D}'}}. We also give a definition related to the same concept based on certain likelihood processes, using the Girsanov theorem. Under certain conditions, the two definitions coincide on D￠{\bf {\mathcal{D}'}}. These results may be used in causal models in that we define what may be the largest class of processes in which influences of one component of a stochastic process on another can be described without ambiguity. From WCLI we can construct a concept of strong local conditional independence (SCLI). When WCLI does not hold, there is a direct influence while when SCLI does not hold there is direct or indirect influence. We investigate whether WCLI and SCLI can be defined via conventional independence conditions and find that this is the case for the latter but not for the former. Finally we recall that causal interpretation does not follow from mere mathematical definitions, but requires working with a good system and with the true probability.