Connecting in a Disconnected World: Tools for Health Professionals to Assess and Expand Adolescent Patients' Connectedness and Webs of Support.

Most health care professionals can help clients connect with others and expand their support networks, and this is within their professional role. For many professionals, we suggest that being able to size up the available sources of support in patients' lives is critical to their overall well-being and creating post-treatment conditions that achieve the greatest health outcomes. This may be especially true for adolescents who often turn to peers and adults outside the home for support.

Finding high posterior density phylogenies by systematically extending a directed acyclic graph.

Bayesian phylogenetics typically estimates a posterior distribution, or aspects thereof, using Markov chain Monte Carlo methods. These methods integrate over tree space by applying local rearrangements to move a tree through its space as a random walk. Previous work explored the possibility of replacing this random walk with a systematic search, but was quickly overwhelmed by the large number of probable trees in the posterior distribution.

Finding high posterior density phylogenies by systematically extending a directed acyclic graph.

Bayesian phylogenetics typically estimates a posterior distribution, or aspects thereof, using Markov chain Monte Carlo methods. These methods integrate over tree space by applying local rearrangements to move a tree through its space as a random walk. Previous work explored the possibility of replacing this random walk with a systematic search, but was quickly overwhelmed by the large number of probable trees in the posterior distribution.

Variational Supertrees for Bayesian Phylogenetics.

Bayesian phylogenetic inference is powerful but computationally intensive. Researchers may find themselves with two phylogenetic posteriors on overlapping data sets and may wish to approximate a combined result without having to re-run potentially expensive Markov chains on the combined data set. This raises the question: given overlapping subsets of a set of taxa (e.

How Trustworthy Is Your Tree? Bayesian Phylogenetic Effective Sample Size Through the Lens of Monte Carlo Error.

Bayesian inference is a popular and widely-used approach to infer phylogenies (evolutionary trees). However, despite decades of widespread application, it remains difficult to judge how well a given Bayesian Markov chain Monte Carlo (MCMC) run explores the space of phylogenetic trees. In this paper, we investigate the Monte Carlo error of phylogenies, focusing on high-dimensional summaries of the posterior distribution, including variability in estimated edge/branch (known in phylogenetics as "split") probabilities and tree probabilities, and variability in the estimated summary tree.

Pathways by which case managers' match support influences youth mentoring outcomes: Testing the systemic model of youth mentoring.

Keller's systemic model of youth mentoring posits there are multiple pathways through which all stakeholders in the youth mentoring process, including the program staff who support the match (or case managers), influence youth outcomes. This study examines case managers' direct and indirect contributions to match outcomes and tests how transitive interactions facilitate a theorized sequence of mentoring interactions to effect greater closeness and length, specifically in nontargeted mentoring programs. A structural equations model of case manager contributions to match outcomes was tested using data from 758 mentor-mentee matches, supported by 73 case managers across seven mentoring agencies.

Shine a light: Under-ice light and its ecological implications in a changing Arctic Ocean.

The Arctic marine ecosystem is shaped by the seasonality of the solar cycle, spanning from 24-h light at the sea surface in summer to 24-h darkness in winter. The amount of light available for under-ice ecosystems is the result of different physical and biological processes that affect its path through atmosphere, snow, sea ice and water. In this article, we review the present state of knowledge of the abiotic (clouds, sea ice, snow, suspended matter) and biotic (sea ice algae and phytoplankton) controls on the underwater light field.

Estimating effective population size changes from preferentially sampled genetic sequences.

Coalescent theory combined with statistical modeling allows us to estimate effective population size fluctuations from molecular sequences of individuals sampled from a population of interest. When sequences are sampled serially through time and the distribution of the sampling times depends on the effective population size, explicit statistical modeling of sampling times improves population size estimation. Previous work assumed that the genealogy relating sampled sequences is known and modeled sampling times as an inhomogeneous Poisson process with log-intensity equal to a linear function of the log-transformed effective population size.

Arctic Climate Change, Economy and Society (ACCESS): Integrated perspectives.

This introduction to the special issue presents an overview of the wide range of results produced during the European Union project Arctic Climate Change, Economy and Society (ACCESS). This project assessed the main impacts of climate change on Arctic Ocean's geophysical variables and how these impending changes could be expected to impact directly and indirectly on socio-economic activities like transportation, marine sea food production and resource exploitation. Related governance issues were examined.

Arctic pathways of Pacific Water: Arctic Ocean Model Intercomparison experiments.

Pacific Water (PW) enters the Arctic Ocean through Bering Strait and brings in heat, fresh water, and nutrients from the northern Bering Sea. The circulation of PW in the central Arctic Ocean is only partially understood due to the lack of observations. In this paper, pathways of PW are investigated using simulations with six state-of-the art regional and global Ocean General Circulation Models (OGCMs).

phylodyn: an R package for phylodynamic simulation and inference.

We introduce phylodyn, an r package for phylodynamic analysis based on gene genealogies. The package's main functionality is Bayesian nonparametric estimation of effective population size fluctuations over time. Our implementation includes several Markov chain Monte Carlo-based methods and an integrated nested Laplace approximation-based approach for phylodynamic inference that have been developed in recent years.

Quantifying and Mitigating the Effect of Preferential Sampling on Phylodynamic Inference.

Phylodynamics seeks to estimate effective population size fluctuations from molecular sequences of individuals sampled from a population of interest. One way to accomplish this task formulates an observed sequence data likelihood exploiting a coalescent model for the sampled individuals' genealogy and then integrating over all possible genealogies via Monte Carlo or, less efficiently, by conditioning on one genealogy estimated from the sequence data. However, when analyzing sequences sampled serially through time, current methods implicitly assume either that sampling times are fixed deterministically by the data collection protocol or that their distribution does not depend on the size of the population.

An efficient Bayesian inference framework for coalescent-based nonparametric phylodynamics.

Motivation: The field of phylodynamics focuses on the problem of reconstructing population size dynamics over time using current genetic samples taken from the population of interest. This technique has been extensively used in many areas of biology but is particularly useful for studying the spread of quickly evolving infectious diseases agents, e.g.

A multicultural assessment of adolescent connectedness: testing measurement invariance across gender and ethnicity.

Counselors, psychologists, and evaluators of intervention programs for youth increasingly view the promotion of connectedness as an important intervention outcome. When evaluating these programs, researchers frequently test whether the treatment effects differ across gender and ethnic or racial groups. Doing so necessitates the availability of culturally and gender-invariant measures.

"I dunno, what do you wanna do?": testing a framework to guide mentor training and activity selection.

Whether relational or goal-directed interactions are most useful in youth mentoring has been frequently debated, but until recently, little work had been done to understand how such interactions manifest to create viable relationship styles. The authors' findings in the first study they explore in this article support Karcher and Nakkula's assertion that relational and goal-directed interactions are distinct. The authors found that both made significant contributions to relationship quality, but for children and preadolescents, relational interactions appeared to be more strongly associated with the quality of the mentoring relationship than did goal-oriented interactions.

Youth mentoring with a balanced focus, shared purpose, and collaborative interactions.

This opening article defines the ways in which three mentoring interaction elements--focus, purpose, and authorship--distinguish between effective and ineffective mentoring relationship styles. The framework described can help mentors better understand the difference between prescriptive and instrumental styles and differentiate laissez-faire from developmental mentoring. It also reveals unique ways for program staff to develop training materials and for researchers to better study mentoring activities.

On the potential for climate change impacts on marine anthropogenic radioactivity in the Arctic regions.

Current predictions as to the impacts of climate change in general and Arctic climate change in particular are such that a wide range of processes relevant to Arctic contaminants are potentially vulnerable. Of these, radioactive contaminants and the processes that govern their transport and fate may be particularly susceptible to the effects of a changing Arctic climate. This paper explores the potential changes in the physical system of the Arctic climate system as they are deducible from present day knowledge and model projections.

The study of mentoring in the learning environment (SMILE): a randomized evaluation of the effectiveness of school-based mentoring.

The effect of providing youth school-based mentoring (SBM), in addition to other school-based support services, was examined with a sample of 516 predominately Latino students across 19 schools. Participants in a multi-component, school-based intervention program run by a youth development agency were randomly assigned to one of two conditions: (1) supportive services alone or (2) supportive services plus SBM. Compared to community-based mentoring, the duration of the SBM was brief (averaging eight meetings), partly because the agency experienced barriers to retaining mentors.

Developmental mentoring match characteristics: correspondence between mentors' and mentees' assessments of relationship quality.

Understanding the factors that contribute to high-quality mentoring relationships is critical to developing and sustaining effective mentoring programs. In study 1, sixty-three adolescent mentors, from two high schools, were surveyed four to six weeks after being matched with elementary-age mentees. Hierarchical regression models revealed that mentees' academic and behavioral risk status, parental involvement, and program quality all explained variance in mentor-perceived relationship quality, but none remained significant predictors after mentors' self-efficacy, motivations for self-enhancement, and assessments of their mentees' support seeking behaviors were accounted for.

How connectedness contributes to experimental smoking among rural youth: developmental and ecological analyses.

The influences of peer, sibling, and parents' smoking on adolescents' initiation of tobacco use have been explained as a function of peer pressure, genetics, and social learning processes, but rarely in combination or with assessments of the quality of these relationships. This study examined the additional contributions of connectedness to friends, siblings, parents, and teachers beyond the effects of friend, sibling, and parental smoking using logistic regression analyses with a cross-sectional middle and high school sample of 303 rural adolescents. Friends' and siblings' smoking, and connectedness to friends, were the strongest predictors of experimental smoking.

Optimisation of sampling for the temporal monitoring of technetium-99 in the Arctic marine environment.

Monitoring of the marine environment for radioactivity, for both radiological protection and oceanographic purposes, remains an expensive and labour intensive activity due to the large sample volumes needed and the complex and lengthy analytical procedures required to measure low levels of contamination. Because of this, some consideration must be given to the design of sampling plans to ensure effective and efficient sampling that can be defended on the basis of scientific rationale. This article tests the hypothesis that geostatistical techniques may prove of use in the optimisation and design of sampling regimes for the monitoring of temporal fluctuations in the levels of technetium at a location in the Norwegian Arctic marine environment.

The dispersion of 99Tc in the Nordic Seas and the Arctic Ocean: a comparison of model results and observations.

The radionuclide (99)Tc had been discharged from the nuclear reprocessing facility in Sellafield (UK) into the Irish Sea in increased amounts in the 1990s. We compare the simulated dispersion of (99)Tc in surface water as calculated by a hydrodynamic model and an assessment box model with field-observations from 1996 to 1999 to study concentrations, pathways and travel times. The model results are consistent with the observations and show the typical pathway of dissolved radionuclides from the Irish Sea via the North Sea along the Norwegian Coast.