Dependencia de la densidad en los ánades norteamericanos

The existence or otherwise of density dependence within a population can have important implications for the management of that population. Here, we use estimates of abundance obtained from annual aerial counts on the major breeding grounds of a variety of North American duck species and use a state space model to separate the observation and ecological system processes. This state space approach allows us to impose a density dependence structure upon the true underlying population rather than on the estimates and we emonstrate the improved robustness of this procedure for detecting density dependence in the population. We adopt a Bayesian approach to model fitting, using Markov chain Monte Carlo (MCMC) methods and use a reversible jump MCMC scheme to calculate posterior model probabilities which assign probabilities to the presence of density dependence within the population, for example. We show how these probabilities can be used either to discriminate between models or to provide model–averaged predictions which fully account for both parameter and model uncertainty.La existencia o ausencia de efectos dependientes de la densidad en una población puede acarrear importantes repercusiones para la gestión de la misma. En este artículo empleamos estimaciones de abundancia obtenidas a partir de recuentos aéreos anuales de las principales áreas de reproducción de diversas especies de ánades norteamericanos, utilizando un modelo de estados espaciales para separar los procesos de observación y los procesos del sistema ecológico. Este enfoque basado en estados espaciales nos permite imponer una estructura que depende de la densidad de la población subyacente real, más que de las estimaciones, además de demostrar la robustez mejorada de este procedimiento para detectar la dependencia de la densidad en la población. Para el ajuste de modelos adoptamos un planteamiento bayesiano, utilizando los métodos de Monte Carlo basados en cadenas de Markov (MCMC), así como un programa MCMC de salto reversible para calcular, por ejemplo, las probabilidades posteriores de los modelos que asignan probabilidades a la presencia de una dependencia de la densidad en la población. También demostramos cómo pueden emplearse estas probabilidades para discriminar entre modelos o para proporcionar predicciones promediadas entre modelos que tengan totalmente en cuenta tanto la incertidumbre referente a parámetros como a modelos

Understanding the Role of Relationship Maintenance in Enduring Couple Partnerships in Later Adulthood

Intimate relationships in later adulthood are understudied despite their positive association with health and well-being. This cross-sectional mixed methods study sought to redress this gap by investigating relationship maintenance in later adulthood. Our international sub-sample comprised 1,565 participants aged 55 + and in an ongoing relationship. Results from hierarchical multiple regression indicated that overall happiness with the relationship had the largest effect size on relationship maintenance, with 53% of the variance explained. Content analyses of open-ended questions identified companionship and laughter as some of the “best liked” aspects of the relationship. Housework/cooking and saying “I love you” were among the behaviors that made participants feel appreciated. Results illustrated the types of maintenance behaviors adults in later adulthood who are in enduring partnerships employ

Fractal-like Distributions over the Rational Numbers in High-throughput Biological and Clinical Data

Recent developments in extracting and processing biological and clinical data are allowing quantitative approaches to studying living systems. High-throughput sequencing, expression profiles, proteomics, and electronic health records are some examples of such technologies. Extracting meaningful information from those technologies requires careful analysis of the large volumes of data they produce. In this note, we present a set of distributions that commonly appear in the analysis of such data. These distributions present some interesting features: they are discontinuous in the rational numbers, but continuous in the irrational numbers, and possess a certain self-similar (fractal-like) structure. The first set of examples which we present here are drawn from a high-throughput sequencing experiment. Here, the self-similar distributions appear as part of the evaluation of the error rate of the sequencing technology and the identification of tumorogenic genomic alterations. The other examples are obtained from risk factor evaluation and analysis of relative disease prevalence and co-mordbidity as these appear in electronic clinical data. The distributions are also relevant to identification of subclonal populations in tumors and the study of the evolution of infectious diseases, and more precisely the study of quasi-species and intrahost diversity of viral populations

A systematic review of post-release programs for women exiting prison with substance-use disorders: assessing current programs and weighing the evidence.

BACKGROUND: The rising rates of women in prison is a serious public health issue. Unlike men, women in prison are characterised by significant histories of trauma, poor mental health, and high rates of substance use disorders (SUDs). Recidivism rates of women have also increased exponentially in the last decade, with substance related offences being the most imprisoned offence worldwide. There is a lack of evidence of the effectiveness of post-release programs for women. The aim of this systematic review is to synthesise and evaluate the evidence on post-release programs for women exiting prison with SUDs. METHODS: We searched eight scientific databases for empirical original research published in English with no date limitation. Studies with an objective to reduce recidivism for adult women (⩾18 years) with a SUD were included. Study quality was assessed using the revised Cochrane Risk of Bias tool for randomized trials (RoB2) and the Risk of Bias in Non-randomized Studies - of Interventions (ROBINS-I) tools. RESULTS: Of the 1493 articles, twelve (n = 3799 women) met the inclusion criteria. Recidivism was significantly reduced in five (42%) programs and substance-use was significantly reduced in one (8.3%) program. Common attributes among programs that reduced recidivism were: transitional, gender-responsive programs; provision of individualised support; providing substance-related therapy, mental health and trauma treatment services. Methodological and reporting biases were common, which impacted our ability to synthesize results further. Recidivism was inconsistently measured across studies further impacting the ability to compare results across studies. CONCLUSIONS: Recidivism is a problematic measure of program efficacy because it is inconsistently measured and deficit-focused, unrecognising of women's gains in the post-release period despite lack of tailored programs and significant health and social disadvantages. The current evidence suggests that women benefit from continuity of care from prison to the community, which incorporated gender-responsive programming and individualised case management that targeted co-morbid mental health and SUDs. Future program design should incorporate these attributes of successful programs identified in this review to better address the unique challenges that women with SUDs face when they transition back into the community

Controlled single electron transfer between Si:P dots

We demonstrate electrical control of Si:P double dots in which the potential is defined by nanoscale phosphorus doped regions. Each dot contains approximately 600 phosphorus atoms and has a diameter close to 30 nm. On application of a differential bias across the dots, electron transfer is observed, using single electron transistors in both dc- and rf-mode as charge detectors. With the possibility to scale the dots down to few and even single atoms these results open the way to a new class of precision-doped quantum dots in silicon.Comment: 3 figures, 3 page

Self-aligned fabrication process for silicon quantum computer devices

We describe a fabrication process for devices with few quantum bits (qubits), which are suitable for proof-of-principle demonstrations of silicon-based quantum computation. The devices follow the Kane proposal to use the nuclear spins of 31P donors in 28Si as qubits, controlled by metal surface gates and measured using single electron transistors (SETs). The accurate registration of 31P donors to control gates and read-out SETs is achieved through the use of a self-aligned process which incorporates electron beam patterning, ion implantation and triple-angle shadow-mask metal evaporation