Tests for Structural Changes in Time Series of Counts

We propose methods for detecting structural changes in time series with discrete‐valued observations. The detector statistics come in familiar L2‐type formulations incorporating the empirical probability generating function. Special emphasis is given to the popular models of integer autoregression and Poisson autoregression. For both models, we study mainly structural changes due to a change in distribution, but we also comment for the classical problem of parameter change. The asymptotic properties of the proposed test statistics are studied under the null hypothesis as well as under alternatives. A Monte Carlo power study on bootstrap versions of the new methods is also included along with a real data example.     

Prediction of posttraumatic stress disorder symptomatology after childbirth – A Croatian longitudinal study

Background

Following childbirth, a vast number of women experience some degree of mood swings, while some experience symptoms of postpartum posttraumatic stress disorder.

Psychophysiological Reactivity in Child Sexual Abuse

Sexual abuse has physiological and emotional implications. The purpose of this study is to evaluate the neurobiological sequels of childhood sexual trauma by monitoring physiological variables among sexually abused girls and women compared to controls. We assessed posttrauma and traumatic life events of 35 females sexually abused in their childhood (age range 7–51 years) and 25 control females (age range 7–54 years). Electroencephalography, frontalis electromyography, electrodermal activity, and heart rate parameters were recorded while watching sets of pictures representing neutral and trauma-suggestive stimuli. A minority of participants met the Diagnostic and Statistical Manual of Mental Disorders criteria for post-traumatic stress disorder. Abused females displayed significant elevations in heart rate, electromyography, and electroencephalography while viewing allusive stimuli and elevated heart rate while viewing neutral stimuli. The dysfunctional regulation of the physiological stress system associated with child sexual abuse may endanger the victims with various stress and anxiety disorders.     

Threatened plant species in the river ports of Central Europe: a potential for nature conservation

Industrialized areas represent a special group of urbanized areas, but sufficient attention has not been given to them concerning plant species richness and its importance for biodiversity conservation. These sites are considered the main drivers of biological invasions and biotic homogenization on a global scale, but the question of how and to what degree they contribute to biodiversity has yet to be raised. Data for 62 river ports (16 German, 26 Czech, 7 Hungarian, 4 Slovak, and 9 Austrian) on two important Central European waterways (the Elbe-Vltava and Danube waterways) were gathered for 40 years. In total, 1 240 plant species were found. Of these, 371 were classified as threatened and protected, nearly one third of the total number of species found in all of the studied Elbe, Vltava, and Danube ports. Significant differences in the proportion of threatened species in ports and cities were not found. More threatened species were found in the Danube ports than in the other ports, but their numbers fluctuated depending on the size of the port and the region (country). The results showed that the ports must be regarded as special types of species-rich industrial areas; thus, they should not be considered to be only sources of spreading invasive alien species. When planning port development, uniformity and vegetation management that is too intensive should be avoided. Extensively managed open areas and habitat diversity should be maintained.

     

Arenas of comfort and conflict: peer relationship events and young people's educational attainment

Previous research suggests that developments in young people's peer relationships may either compound or alleviate the adverse impacts of other major life changes during adolescence. We explored this proposition with respect to young people's educational attainment upon leaving high school, using longitudinal data from a large cohort of Australian secondary school students (n?=?1612) who have taken part in the Our Lives research study between the ages of 12/13 and 19/20 years. Our analysis focused on the role of peer relationship events such bullying, friendship problems, falling in love, and breaking up with someone. Bullying and romantic involvement were associated with lower odds of receiving a competitive tertiary entrance rank at the end of high school. However, close, resilient friendships – in which status and identity conflicts may be more easily tolerated and resolved – may help to offset the role of these other events. As well as reviewing the consequences of our findings for young people's educational and occupational trajectories in the longer-term, we highlight their implications for future research and policy in this area.     

How Can Low‐income Countries Gain from a Framework Agreement on Climate Change? An Analysis with Integrated Assessment Modelling

By using the integrated assessment model RICE this article carries out a scenario analysis with different assumptions about international negotiations on climate change, in particular hypothesising about reduction in targets for greenhouse gas emissions, technology transfers and financial transfer programmes. It finds that, in terms of growth, developing countries and in particular sub‐Saharan Africa will benefit from agreements that reduce the level of pollution and promote technological diffusion. Moreover, when developed countries are subject to emissions limits and poor regions have no such commitments, financial transfers from rich to developing countries for adaptation and mitigation enhance pro‐poor growth and help the effectiveness of poor countries in reducing emissions.     

Stochastic Bounds with a Low Rank Decomposition

We investigate how we can bound a discrete time Markov chain (DTMC) by a stochastic matrix with a low rank decomposition. In the first part of the article, we show the links with previous results for matrices with a decomposition of size 1 or 2. Then we show how the complexity of the analysis for steady-state and transient distributions can be simplified when we take into account the decomposition. Finally, we show how we can obtain a monotone stochastic upper bound with a low rank decomposition.     

当面试官问你会拒绝总裁安排的任务吗？

这道问题曾难倒不下百位候选人,回答“任务应该逐级分派,我会拒绝他的要求”和“我会按领导吩咐执行”都不是令人满意的回答。还是重复了千万次提到的观点——答案其实不重要。很多时候没有完全正确的答案,重要的是展示我们的思路和我们解决问题的方法与智慧。只需做到“具体分析、区别对待”,不难回答棘手的问题。     

Contrasting the Gini and Zenga indices of economic inequality

The current financial turbulence in Europe inspires and perhaps requires researchers to rethink how to measure incomes, wealth, and other parameters of interest to policy-makers and others. The noticeable increase in disparities between less and more fortunate individuals suggests that measures based upon comparing the incomes of less fortunate with the mean of the entire population may not be adequate. The classical Gini and related indices of economic inequality, however, are based exactly on such comparisons. It is because of this reason that in this paper we explore and contrast the classical Gini index with a new Zenga index, the latter being based on comparisons of the means of less and more fortunate sub-populations, irrespectively of the threshold that might be used to delineate the two sub-populations. The empirical part of the paper is based on the 2001 wave of the European Community Household Panel data set provided by EuroStat. Even though sample sizes appear to be large, we supplement the estimated Gini and Zenga indices with measures of variability in the form of normal, t-bootstrap, and bootstrap bias-corrected and accelerated confidence intervals.