A comparative study of life history and gene flow in darters (Pisces: Percidae)

Gene flow, or the exchange of genes between populations, is important because it determines the evolutionary trajectory of a species, including the relative influences of genetic drift and natural selection in the process of population differentiation. Gene flow differs among species because of variation in dispersal capability and abundances across taxa, and historical forces related to geological or lineage history. Both history and ecology influence gene flow in potentially complicated ways, and accounting for their effects remains an important problem in evolutionary biology. This research is a comparative study of gene flow and life-history in a monophyletic group of stream fishes, the darters. As a first step in disentangling historical and ecological effects, I reconstructed the phylogenetic relationships of the study species from nucleotide sequences in the mtDNA control region. I then used this phylogeny and regional glaciation history to infer historical effects on life-history evolution and gene flow in 15 species of darters. Gene flow was estimated indirectly, using information from 20 resolvable and polymorphic allozyme loci. When I accounted for historical effects, comparisons across taxa revealed that gene flow rates were closely associated with differences in clutch sizes and reproductive investment patterns. I hypothesized that differences in larval dispersal among taxa explained this relationship. Results from a field study of larval drift were consistent with this hypothesis. Finally, I asked whether there was an interaction between species' ecology and genetic differentiation across biogeographically distinct regions. Information from allozymes and mtDNA sequences revealed that life history plays an important role in the magnitude of species divergence across biogeographic boundaries. These results suggested an important association between life histories and rates of speciation following an allopatric isolation event. This research, along with other studies from the literature, further illustrates the enormous potential of North American freshwater fishes as a system for studying speciation processes. ^

Life pathways of Haitian-American young adults in South Florida

This research examines the life pathways of 1.5 and second generation Haitian immigrants in South Florida. The purpose of the research is to better understand how integration occurs for the children of Haitian immigrants as they transition from adolescence to adulthood. Building upon a prior study of second-generation immigrant adolescents between 1995 and 2000, a sub-set of the original participants was located to participate in this follow-up research. Qualitative interviews were conducted as well as in-depth ethnographic research, including participant observation. Survey instruments used with other second-generation populations were also administered, enabling comparisons with the Children of Immigrants Longitudinal Study (CILS). The results indicate that educational and occupational achievements were markedly below the participants’ original expectations as adolescents. Gender figures prominently in participants’ familial roles and relationships, with men and women distinctly incorporating both Haitian and American cultural practices within their households. Contrary to previous research, these results on the identification of participants suggest that these young adults claim attachment to both Haiti and to the United States. The unique longitudinal and ethnographic nature of this study contributes to the ongoing discussion of the integration of the children of immigrants by demonstrating significant variation from the prior integration trends observed with Haitian adolescents. The results cast doubt on existing theory on the children of immigrants for explaining the trajectory of Haitian-American integration patterns. Specifically, this research indicates that Haitians are not downwardly mobile and integrating as African Americans. They have higher education and economic standing than their parents and are continuing their education well into their thirties. The respondents have multiple identities in which they increasingly express identification with Haiti, but in some contexts are also developing racialized identifications with African Americans and others of the African diaspora.

Depression screening and referral in cardiac wards: A 12-month patient trajectory

Background: Depression is common among patients with coronary heart disease (CHD) and has a major impact on their quality of life, morbidity and mortality. Aim: The aim of this study was to map the 12-month psychosocial outcomes of patients with CHD who were screened positive for depression in an acute cardiac ward.

Methods: A prospective cohort study was conducted of the psychosocial trajectory (depression, anxiety, wellbeing, social support, mental health service access) of 212 patients with CHD who were screened for depression after being admitted to acute cardiac wards of a major metropolitan hospital. Outcomes were assessed before hospital discharge and at one, three, six and 12 months post-discharge.

Results: Linear mixed models identified that those patients screened at ‘moderate to high’ risk of depression at baseline had higher levels of depression (F(1,173)=53.93, p<0.0001) and anxiety (F(1,180)=67.01, p<0.001), and lower levels of wellbeing (F(1,186)=42.47, p<0.001) and social support (F(1,177)=25.40, p<0.0001), compared to those at ‘no to low’ risk of depression. Levels of depression and wellbeing remained fairly constant over the 12-month trajectory. Surgical and medical treatment groups were of similar psychological composition over the 12-month period.

Conclusions: These findings attest to the effectiveness and predictive validity of a simple nurse-administered screening tool designed to identify depression in hospital patients with CHD and also indicate that a screening and referral tool alone is not sufficient to achieve optimal disease management. A collaborative care model involving family members and integrated pathways to primary care is recommended.

A visual-numeric approach to clustering and anomaly detection for trajectory data

This paper proposes a novel application of Visual Assessment of Tendency (VAT)-based hierarchical clustering algorithms (VAT, iVAT, and clusiVAT) for trajectory analysis. We introduce a new clustering based anomaly detection framework named iVAT+ and clusiVAT+ and use it for trajectory anomaly detection. This approach is based on partitioning the VAT-generated Minimum Spanning Tree based on an efficient thresholding scheme. The trajectories are classified as normal or anomalous based on the number of paths in the clusters. On synthetic datasets with fixed and variable numbers of clusters and anomalies, we achieve 98 % classification accuracy. Our two-stage clusiVAT method is applied to 26,039 trajectories of vehicles and pedestrians from a parking lot scene from the real life MIT trajectories dataset. The first stage clusters the trajectories ignoring directionality. The second stage divides the clusters obtained from the first stage by considering trajectory direction. We show that our novel two-stage clusiVAT approach can produce natural and informative trajectory clusters on this real life dataset while finding representative anomalies.

Caring for people with diabetes at the end of life

End-of-life care planning is assuming global significance. While general end-of-life care guidelines apply to diabetes, there are some diabetes-specific issues that need to be considered. These include the usual long trajectory to end-of-life care that enables clinicians and people with diabetes to proactively discuss when to change the focus of care from preventing diabetes complications (tight control) to a palliative approach. Palliative care aims to promote comfort and quality of life and reduce the unnecessary burden of care on individuals and their families. The aim of this paper is to discuss common disease trajectories and their relationship to diabetes care, outline strategies for proactively discussing these issues and suggest indications that palliative care is warranted.

The Scored Patient-Generated Subjective Global Assessment (PG-SGA) and its Association with Quality of Life in Ambulatory Patients Receiving Radiotherapy

OBJECTIVE: To evaluate the scored Patient-generated Subjective Global Assessment (PG-SGA) tool as an outcome measure in clinical nutrition practice and determine its association with quality of life (QoL). DESIGN: A prospective 4 week study assessing the nutritional status and QoL of ambulatory patients receiving radiation therapy to the head, neck, rectal or abdominal area. SETTING: Australian radiation oncology facilities. SUBJECTS: Sixty cancer patients aged 24-85 y. INTERVENTION: Scored PG-SGA questionnaire, subjective global assessment (SGA), QoL (EORTC QLQ-C30 version 3). RESULTS: According to SGA, 65.0% (39) of subjects were well-nourished, 28.3% (17) moderately or suspected of being malnourished and 6.7% (4) severely malnourished. PG-SGA score and global QoL were correlated (r=-0.66, P<0.001) at baseline. There was a decrease in nutritional status according to PG-SGA score (P<0.001) and SGA (P<0.001); and a decrease in global QoL (P<0.001) after 4 weeks of radiotherapy. There was a linear trend for change in PG-SGA score (P<0.001) and change in global QoL (P=0.003) between those patients who improved (5%) maintained (56.7%) or deteriorated (33.3%) in nutritional status according to SGA. There was a correlation between change in PG-SGA score and change in QoL after 4 weeks of radiotherapy (r=-0.55, P<0.001). Regression analysis determined that 26% of the variation of change in QoL was explained by change in PG-SGA (P=0.001). CONCLUSION: The scored PG-SGA is a nutrition assessment tool that identifies malnutrition in ambulatory oncology patients receiving radiotherapy and can be used to predict the magnitude of change in QoL.

Integrating health and sustainability in life cycle assessment

Until now health impact assessment and environmental impact assessment are two different issues, often not addressed together. Both issues have to be dealt with for sustainable building. The aim of this paper is to link healthy and sustainable housing in life cycle assessment. Two strategies are studied: clean air as a functional unity and health as a quality indicator. The strategies are illustrated with an example on the basis of Eco-Quantum, which is a Dutch whole-building assessment tool. It turns out that both strategies do not conflict with the LCA methodology. The LCA methodology has to be refined for this purpose.