Urban hazards: spatial ecology and survivorship of a turtle in an expanding suburban environment

Urban Ecosystems - Urbanization poses a threat to long-lived vertebrates, particularly from road mortalities that can threaten population persistence. We studied movements, behavior and...     

Auswirkungen von Macht auf das ��berleben in Extremsituationen: Ein Vergleich der Titanic und Lusitania Schiffskatastrophen

Comparing the Titanic and Lusitania disaster the impact of financial and physical power as well as the emergence of social norms on survival during life-and-death situations is analyzed. Despite the fact that some maritime disasters have become famous, a quantitative understanding of survival in life-and-death situations is still lacking. In a quasi-natural experiment multivariate probit estimations are conducted based on publicly available data. The paper suggests that in life-and-death situations differences in time restrictions are crucial. When time is scarce individual self-interested fight-or-flight behavior will predominate and result in a stronger competition for survival. In contrast, altruism and adherence to social norms emerge when there is sufficient time to reflect on the event and circumstances: Social norms require time to evolve, and they loose against physical strength in a shorter window of opportunity.     

Abstracts

Objective: To ascertain if two commonly used health status measures could be successfully self-administered to a group of older men recruited from the community to volunteer for a clinical research project and to correlate responses to the health status questionnaire to testosterone levels. Methods: In a cross-sectional survey 93 men, age 70 or greater, responded to a random mailing to a suburban community. Sixty-eight men were eligible and 47 participated in the study. Two health status questionnaires, the Sickness Impact Profile (SIP) and the Short-form 36 (SF-36), were mailed to participants with instructions to complete the surveys on the same day and return them by mail. Blood samples were obtained for bioavailable and total testosterone measurements. Pearson correlation coefficient analysis was used to compare the responses to the SF-36 and SIP and testosterone levels. Results: Of the eligible volunteers 69% participated and were able to self-administer the SIP and the SF-36. Summation scores for the surveys were above those reported in similar age populations. Perfect scores were reported frequently in all subsets of the SIP; perfect scores were reported in 43-92% of men on various subscales. The responses to the SF-36 were also frequently perfect although perfect scores ranged from 2 to 82% on various subsets. There was moderate correlation between the results from the two surveys. There was no correlation between age, SIP or SF-36 and testosterone level. Conclusions: Healthy older men volunteering for clinical research were able to self-administer both the SIP and SF3-6. Responses to both surveys were skewed toward perfect scores; the SIP failed to reveal many men with functional deficits. Bioavailable testosterone levels did not predict perceived health in this group of men.     

Bayesian adaptive dose‐escalation designs for simultaneously estimating the optimal and maximum safe dose based on safety and efficacy

The main purpose of dose‐escalation trials is to identify the dose(s) that is/are safe and efficacious for further investigations in later studies. In this paper, we introduce dose‐escalation designs that incorporate both the dose‐limiting events and dose‐limiting toxicities (DLTs) and indicative responses of efficacy into the procedure. A flexible nonparametric model is used for modelling the continuous efficacy responses while a logistic model is used for the binary DLTs. Escalation decisions are based on the combination of the probabilities of DLTs and expected efficacy through a gain function. On the basis of this setup, we then introduce 2 types of Bayesian adaptive dose‐escalation strategies. The first type of procedures, called “single objective,” aims to identify and recommend a single dose, either the maximum tolerated dose, the highest dose that is considered as safe, or the optimal dose, a safe dose that gives optimum benefit risk. The second type, called “dual objective,” aims to jointly estimate both the maximum tolerated dose and the optimal dose accurately. The recommended doses obtained under these dose‐escalation procedures provide information about the safety and efficacy profile of the novel drug to facilitate later studies. We evaluate different strategies via simulations based on an example constructed from a real trial on patients with type 2 diabetes, and the use of stopping rules is assessed. We find that the nonparametric model estimates the efficacy responses well for different underlying true shapes. The dual‐objective designs give better results in terms of identifying the 2 real target doses compared to the single‐objective designs.     

Compact labelings for efficient first-order model-checking

We consider graph properties that can be checked from labels, i.e., bit sequences, of logarithmic length attached to vertices. We prove that there exists such a labeling for checking a first-order formula with free set variables in the graphs of every class that is nicely locally clique-width-decomposable. This notion generalizes that of a nicely locally tree-decomposable class. The graphs of such classes can be covered by graphs of bounded clique-width with limited overlaps. We also consider such labelings for bounded first-order formulas on graph classes of bounded expansion. Some of these results are extended to counting queries.     

A note on new confidence intervals for the difference between two proportions based on an Edgeworth expansion

Zhou and Qin [2004. New intervals for the difference between two independent binomial proportions. J. Statist. Plann. Inference 123, 97–115; 2005. A new confidence interval for the difference between two binomial proportions of paired data. J. Statist. Plann. Inference 128, 527–542] “new confidence intervals” for the difference between two treatment proportions exhibit a severe lack of invariance property that is a compelling reason not to use them.     

Tests of serial independence based on Kendall's process

The authors propose new rank statistics for testing the white noise hypothesis in a time series. These statistics are Cramér‐von Mises and Kolmogorov‐Smirnov functionals of an empirical distribution function whose mean is related to a serial version of Kendall's tau through a linear transform. The authors determine the asymptotic behaviour of the underlying serial process and the large‐sample distribution of the proposed statistics under the null hypothesis of white noise. They also present simulation results showing the power of their tests.     

Microaggressions,perceptions of campus climate,mental health,and alcohol use among first-year college students of color

Depressive and anxiety symptoms are increasingly common, and problematic alcohol use remains prevalent in college. To expand on prior research on mostly white samples, we surveyed first-year students of color from our predominately white university (Southeastern US) to identify risk factors for mental health symptoms and potentially co-occurring problematic alcohol use. Results showed significant associations between microaggressions and poor campus climate (hypothetical predictors) with depressive, anxiety, somatic symptoms (hypothetical outcomes) that were indirectly linked through perceived stress, poor sleep, and academic burnout (hypothetical mediators). Poor campus climate, academic burnout, and using alcohol to cope were the most relevant to alcohol use disorder symptoms. Results support efforts to address and reduce racial microaggressions and promote a positive campus climate for all.