3,849 research outputs found
Examining Depressive Symptoms Over Time in Women with Coronary Heart Disease
Coronary heart disease (CHD) is the number one killer of women in the US. Women also experience roughly twice as much depression as men, and depression in CHD is associated with increased morbidity and mortality. Despite these facts, women continue to be under-represented in CHD research, and results by gender are not routinely reported.
Screening for depression in this population is problematic due to inconsistent inclusion of somatic symptoms on screening instruments and disagreement about appropriate cutoff scores.
This body of work clarifies the concept of depression in women with CHD, presents a systematic review of the longitudinal literature on depressive symptoms in women with CHD examined by instrument, and presents results of a 3-month feasibility study examining women’s depressive symptoms. The purpose of the study was to evaluate participant enrollment, data collection, preliminary quantitative trends, and qualitative surveys for qualitative data collection.
Participant recruitment by individuals other than the P.I. was generally poor and attrition was problematic (16.7 – 28%). Prevalence of mean depression screening scores ≥ cutoff values averaged 30% at baseline, 26% at month 2, and 25% at month 3. Trends in symptom severity over the course of the study reflected trends in somatic symptoms and distress but not cognitive symptoms. Current depression was strongly correlated with fatigue and sleep as well as younger age, comorbid diabetes, a history of anxiety, and acute coronary syndrome symptoms. It was less strongly correlated with a history of depression and cardiac rehabilitation attendance. No correlation was found between current depression and employment status. Qualitative survey uptake was poor and the original survey was too restrictive, requiring modification.
This dissertation clarifies our understanding of the concept of depression in women with CHD and summarizes the longitudinal descriptive literature on depression in women with CHD. The dissertation study enhances our understanding of depressive symptoms experienced in this population, gives some important preliminary data on use of the PROMIS Depression 8b instrument in this population, highlights the importance of screening for depressive symptoms in this population, and emphasizes the ongoing need for CHD studies which examine and report data by gender
Role of CaMKII in Pancreatic Alpha Cells
Calcium/calmodulin-dependent protein kinase II (CaMKII) has been identified as an important modulator in controlling electrical activity in neurons and the heart; however, a role for CaMKII in pancreatic alpha cell signaling has not been previously reported. Upon activation by calcium/calmodulin, CaMKII phosphorylates proteins involved in intracellular calcium homeostasis by inducing downstream effects such as an increase in AMPA-receptor single channel conductance, potentiation of L-type voltage dependent calcium channels, and enhanced surface expression of inhibitory GABAA-receptors. In the pancreas, an increase in intracellular calcium drives secretion of glucagon from alpha cells within the Islets of Langerhans. α-cells contain many of the known targets of CaMKII described in neurons, including AMPA/GluR1 receptors, L-type VGCC and GABAA-receptors. CaMKII may also regulate other aspects of glucagon secretion, aside from calcium homeostasis, such as vesicle trafficking, exocytosis, and cytoskeleton dynamics. Based on the expression of CaMKII targets and the requirement of calcium influx for hormone secretion, we explored which CaMKII genes, if any, are found in α-cells, and are involved in the regulation of α-cell signaling and glucagon release
Abundant variation in microsatellites of the parasitic nematode Trichostrongylus tenuis and linkage to a tandem repeat
An understanding of how genes move between and within populations of parasitic nematodes is important in combating the evolution and spread of anthelmintic resistance. Much has been learned by studying mitochondrial DNA markers, but autosomal markers such as microsatellites have been applied to only a few nematode species, despite their many advantages for studying gene flow in eukaryotes. Here, we describe the isolation of 307 microsatellites from Trichostrongylus tenuis, an intestinal nematode of red grouse. High levels of variation were revealed at sixteen microsatellite loci (including three sex-lined loci) in 111 male T. tenuis nematodes collected from four hosts at a single grouse estate in Scotland (average He = 0.708; mean number of alleles = 12.2). A population genetic analysis detected no deviation from panmixia either between (F(ST) = 0.00) or within hosts (F(IS) = 0.015). We discuss the feasibility of developing microsatellites in parasitic nematodes and the problem of null alleles. We also describe a novel 146-bp repeat element, TteREP1, which is linked to two-thirds of the microsatellites sequenced and is associated with marker development failure. The sequence of TteREP1 is related to the TcREP-class of repeats found in several other trichostrongyloid species including Trichostrongylus colubriformis and Haemonchus contortus
Chronic exposure to neonicotinoids increases neuronal vulnerability to mitochondrial dysfunction in the bumblebee (Bombus terrestris)
This work was funded jointly by the Biotechnology and Biological Sciences Research Council, the Department for Environment, Food and Rural Affairs, the Natural Environment Research Council, the Scottish Government, and The Wellcome Trust, under the Insect Pollinators Initiative (United Kingdom) Grant BB/ 1000313/1 (to C.N.C.).The global decline in the abundance and diversity of insect pollinators could result from habitat loss, disease, and pesticide exposure. The contribution of the neonicotinoid insecticides (e.g., clothianidin and imidacloprid) to this decline is controversial, and key to understanding their risk is whether the astonishingly low levels found in the nectar and pollen of plants is sufficient to deliver neuroactive levels to their site of action: the bee brain. Here we show that bumblebees (Bombusterrestris audax) fed field levels [10 nM, 2.1 ppb (w/w)] of neonicotinoid accumulate between 4 and 10 nM in their brains within 3 days. Acute (minutes) exposure of cultured neurons to 10 nM clothianidin, but not imidacloprid, causes a nicotinic acetylcholine receptor-dependent rapid mitochondrial depolarization. However, a chronic (2 days) exposure to 1 nM imidacloprid leads to a receptor-dependent increased sensitivity to a normally innocuous level of acetylcholine, which now also causes rapid mitochondrial depolarization in neurons. Finally, colonies exposed to this level of imidacloprid show deficits in colony growth and nest condition compared with untreated colonies. These findings provide a mechanistic explanation for the poor navigation and foraging observed in neonicotinoid treated bumblebee colonies.Publisher PDFPeer reviewe
Goodness-of-fit measures of evenness: a new tool for exploring changes in community structure
Growing concern about the fate of biodiversity, highlighted by the Convention on Biological Diversity's 2010 and 2020 targets for stemming biodiversity loss, has intensified interest in methods of assessing change in ecological communities through time. Biodiversity is a multivariate concept, which cannot be well‐represented by a single measure. However, diversity profiles summarize the multivariate nature of multi‐species datasets, and allow a more nuanced interpretation of biodiversity trends than unitary metrics. Here we introduce a new approach to diversity profiling. Our method is based on the knowledge that an ecological community is never completely even and uses this departure from perfect evenness as a novel and insightful way of measuring diversity. We plot our measure of departure as a function of a free parameter, to generate “evenness profiles”. These profiles allow us to separate changes due to dominant species from those due to rare species, and relate these patterns to shifts in overall diversity. This separation of the influence of dominance and rarity on overall diversity enables the user to uncover changes in diversity that would be masked in other methods. We discuss profiling techniques based on this parametric family, and explore its connections with existing diversity indices. Next, we evaluate our approach in terms of predicted community structure (following Tokeshi's niche models) and present an example assessing temporal trends in diversity of British farmland birds. We conclude that this method is an informative and tractable parametric approach for quantifying evenness. It provides novel insights into community structure, revealing the contributions of both rare and common species to biodiversity trends
Optoacoustic solitons in Bragg gratings
Optical gap solitons, which exist due to a balance of nonlinearity and
dispersion due to a Bragg grating, can couple to acoustic waves through
electrostriction. This gives rise to a new species of ``gap-acoustic'' solitons
(GASs), for which we find exact analytic solutions. The GAS consists of an
optical pulse similar to the optical gap soliton, dressed by an accompanying
phonon pulse. Close to the speed of sound, the phonon component is large. In
subsonic (supersonic) solitons, the phonon pulse is a positive (negative)
density variation. Coupling to the acoustic field damps the solitons'
oscillatory instability, and gives rise to a distinct instability for
supersonic solitons, which may make the GAS decelerate and change direction,
ultimately making the soliton subsonic.Comment: 5 pages, 3 figure
Prioritisation of companion dog welfare issues using expert consensus
Resources for tackling animal welfare issues are often limited. Obtaining a consensus of expert opinion on the most pressing issues to address is a valuable approach to try to ensure that resources are wisely spent. In this study, seven independent experts in a range of disciplines (including veterinary medicine, animal behaviour and welfare science and ethics) were consulted on the relative prioritisation of welfare issues impacting companion dogs in Great Britain. Experts first anonymously ranked the priority of 37 welfare issues, pre-defined from a literature review and an earlier published survey. In a subsequent two-day panel workshop, experts refined these issues into 25 composite groups and used specific criteria to agree their relative priorities as a Welfare Problem (WP; incorporating numbers of dogs affected, severity, duration and counter-balancing benefits) and a Strategic Priority (SP; a combination of WP and tractability). Other criteria — anthropogenicity, ethical significance and confidence in the issue-relevant evidence — were also discussed by the panel. Issues that scored highly for both WP and SP were: inappropriate husbandry, lack of owner knowledge, undesirable behaviours, inherited disease, inappropriate socialisation and habituation and conformation-related disorders. Other welfare issues, such as obese and overweight dogs, were judged as being important for welfare (WP) but not strategic priorities (SP), due to the expert-perceived difficulties in their management and resolution. This information can inform decisions on where future resources can most cost-effectively be targeted, to bring about the greatest improvement in companion dog welfare in Great Britain
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