36 research outputs found

    Climate Change and invasibility of the Antarctic benthos

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    Benthic communities living in shallow-shelf habitats in Antarctica (<100-m depth) are archaic in their structure and function. Modern predators, including fast-moving, durophagous (skeleton-crushing) bony fish, sharks, and crabs, are rare or absent; slow-moving invertebrates are the top predators; and epifaunal suspension feeders dominate many soft substratum communities. Cooling temperatures beginning in the late Eocene excluded durophagous predators, ultimately resulting in the endemic living fauna and its unique food-web structure. Although the Southern Ocean is oceanographically isolated, the barriers to biological invasion are primarily physiological rather than geographic. Cold temperatures impose limits to performance that exclude modern predators. Global warming is now removing those physiological barriers, and crabs are reinvading Antarctica. As sea temperatures continue to rise, the invasion of durophagous predators will modernize the shelf benthos and erode the indigenous character of marine life in Antarctica

    The association of academic tracking to depressive symptoms among adolescents in three Caribbean countries

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    <p>Abstract</p> <p>Background</p> <p>Students who are tracked into low performing schools or classrooms that limit their life chances may report increased depressive symptoms. Limited research has been conducted on academic tracking and its association with depressive symptoms among high school students in the Caribbean. This project examines levels of depressive symptoms among tenth grade students tracked within and between high schools in Jamaica, St. Vincent and St. Kitts and Nevis.</p> <p>Methods</p> <p>Students enrolled in grade ten of the 2006/2007 academic year in Jamaica, St. Kitts and Nevis and St. Vincent were administered the Beck Depression Inventory II (BDI-II). In Jamaica and St. Vincent, academic tracking was operationalized using data provided by the local Ministries of Education. These Ministries ranked ordered schools according to students' performance on Caribbean school leaving examinations. In St. Kitts and Nevis tracking was operationalized by classroom assignments within schools whereby students were grouped into classrooms according to their levels of academic achievement. Multiple regression analyses were conducted to examine the relationships between academic tracking and BDI-II depression scores.</p> <p>Results</p> <p>A wide cross-section of 4<sup>th </sup>form students in each nation was sampled (n = 1738; 278 from Jamaica, 737 St. Kitts and Nevis, 716 from St. Vincent; 52% females, 46.2% males and 1.8% no gender reported; age 12 to 19 years, mean = 15.4 yrs, sd = .9 yr). Roughly half (53%) of the students reported some symptoms of depression with 19.2% reporting moderate and 10.7% reporting severe symptoms of depression. Students in Jamaica reported significantly higher depression scores than those in either St. Kitts and Nevis or St. Vincent (p < .01). Students assigned to a higher academic track reported significantly lower BDI-II scores than students who were assigned to the lower academic track (p < .01).</p> <p>Conclusions</p> <p>There appears to be an association between academic tracking and depressive symptoms that is differentially manifested across the islands of Jamaica, St. Kitts and Nevis and St. Vincent.</p

    Depression and loneliness in Jamaicans with sickle cell disease

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    <p>Abstract</p> <p>Background</p> <p>Sickle cell disease (SCD) is the commonest genetic disorder in Jamaica, and has life-long implications for those afflicted with it. It is well known that depression and loneliness may exist in those with chronic diseases, but the coexistence of depression and loneliness in people with sickle cell disease is not clear. The aim of this study is to determine the prevalence of and factors associated with depression and loneliness in the Jamaica Sickle Cell Cohort Study and its age and sex matched controls.</p> <p>Methods</p> <p>277 patients with SCD and 65 controls were administered a questionnaire that studied demographics, disease severity, depression, and loneliness. Regression analyses were done to examine relationships between outcomes and associated variables.</p> <p>Results</p> <p>Depression was found in 21.6% of patients and 9.4% in controls. Loneliness scores were also significantly higher in patients (16.9 ± 5.1) than in controls (14.95 ± 4.69). Depression was significantly associated with unemployment [OR = 2.9, p-value: < 0.001], whereas unemployment (p-value: 0.002), and lower educational attainment were significantly associated with loneliness.</p> <p>In patients with SCD, depression was significantly associated with being unemployed (OR 2.4, 95% CI 1.2,4.6, p-value:0.01), presence of a leg ulcer (OR = 3.8, 95% CI: 1.7, 8.4, p-value: 0.001), frequent visits (OR = 3.3, 95% CI: 1.2, 8.9, p-value: 0.019), and frequent painful crises (OR = 2.5, 95% CI: 1.1, 5.8, p-value: 0.035). Not being employed (Coef.: 2.0; p-value: 0.004) and higher educational attainment (tertiary vs. primary education, Coef.: -5.5; p-value: < 0.001) were significant associations with loneliness after adjusting for genotype.</p> <p>Conclusions</p> <p>Health workers need to actively look for and manage these problems to optimize their patients' total biopsychosocial care.</p

    Repriming DNA synthesis: an intrinsic restart pathway that maintains efficient genome replication

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    To bypass a diverse range of fork stalling impediments encountered during genome replication, cells possess a variety of DNA damage tolerance (DDT) mechanisms including translesion synthesis, template switching, and fork reversal. These pathways function to bypass obstacles and allow efficient DNA synthesis to be maintained. In addition, lagging strand obstacles can also be circumvented by downstream priming during Okazaki fragment generation, leaving gaps to be filled post-replication. Whether repriming occurs on the leading strand has been intensely debated over the past half-century. Early studies indicated that both DNA strands were synthesised discontinuously. Although later studies suggested that leading strand synthesis was continuous, leading to the preferred semi-discontinuous replication model. However, more recently it has been established that replicative primases can perform leading strand repriming in prokaryotes. An analogous fork restart mechanism has also been identified in most eukaryotes, which possess a specialist primase called PrimPol that conducts repriming downstream of stalling lesions and structures. PrimPol also plays a more general role in maintaining efficient fork progression. Here, we review and discuss the historical evidence and recent discoveries that substantiate repriming as an intrinsic replication restart pathway for maintaining efficient genome duplication across all domains of life

    The Impact of DSM-IV Mental Disorders on Adherence to Combination Antiretroviral Therapy Among Adult Persons Living with HIV/AIDS: A Systematic Review

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    Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

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    BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

    Subjective Well-being of Adults with Homozygous Sickle Cell Disease in Jamaica

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    Objectives: This study compared the subjective well-being of adults with homozygous sickle cell (SS) disease to a matched group of healthy adult peers. The differential influence of sociodemographic factors on the subjective well-being of Sickle Cell patients was also examined. Methods: The Ferran and Powers Quality of Life Index and the Positive and Negative Affect Schedule were used to assess subjective well-being. Seventy-five homozygous sickle cell (SS) disease patients and sixty-seven matched controls (adults with normal haemoglobin: AA) from the Sickle Cell Disease Cohort Study in Jamaica were interviewed. Analysis of variance (ANOVA) was used to examine differences between the groups. Result: Patients with Sickle cell (SS) disease were less satisfied than matched controls with their lives overall, their health and functioning, social and economic situation and psychological functioning. Sickle cell disease patients reported lower levels of positive affect but similar levels of negative affect as controls. Unemployed sickle cell disease patients were less satisfied than all other adults with their lives overall, health and functioning, psychological functioning and social and economic situation. Sickle cell disease patients with lower occupational status were less satisfied with their family life than all other adults. Conclusions: These findings suggest that subjective well-being is compromised in patients with homozygous sickle cell disease. These patients may benefit from interventions designed to improve their subjective well-being. Keywords: Adults, Jamaica, negative affect, positive affect, subjective well-being, sickle cell disease, quality of life. "Bienestar subjetivo de los adultos con la enfermedad de células falciformes homocigóticas en Jamaica" RESUMEN Objetivos: Este estudio comparó el bienestar subjetivo de los adultos con enfermedad de células falciformes homocigóticas (SS) con el de un grupo pareado de adultos saludables. También se analizó la influencia diferencial de factores sociodemográficos sobre el bienestar subjetivo de los pacientes con la enfermedad de células falciformes. Métodos: El Índice de Calidad de Vida de Ferrans and Powers, y las Escalas de Afecto Positivo y Afecto Negativo (PANAS) fueron usados para evaluar el bienestar subjetivo. Setenta y cinco pacientes con enfermedad de células falciformes homocigóticas (SS), y sesenta y siete controles pareados (adultos con hemoglobina normal: AA) del Estudio de Cohorte de la Enfermedad de Células Falciformes en Jamaica fueron entrevistados. El análisis de varianza (ANOVA) fue utilizado para estudiar las diferencias entre los grupos. Resultado: Los pacientes con enfermedad de células falciformes (SS) mostraron en general un menor grado de satisfacción con sus vidas, su salud y funcionamiento, situación social y económica y funcionamiento psicológico. Los pacientes con la enfermedad de células falciformes reportaron niveles más bajos de afecto positivo, pero mostraron en cambio niveles similares de afecto negativo en relación con los controles. Los pacientes con la enfermedad de células falciformes desempleados estuvieron menos satisfechos con sus vidas en general, su salud y funcionamiento, su funcionamiento psicológico, y su situación económica y social, que todos los otros adultos. Los pacientes con la enfermedad de células falciformes de un nivel ocupacional más bajo, estuvieron menos satisfechos con su vida familiar que todos los otros adultos. Conclusiones: Estos hallazgos sugieren que el bienestar subjetivo está comprometido en pacientes con la enfermedad de células falciformes homocigóticas. Estos pacientes pueden beneficiarse de las intervenciones destinadas a mejorar su bienestar subjetivo. Palabras claves: Adultos, Jamaica, afecto negativo, afecto positivo, calidad de vida, enfermedad de células falciformes, bienestar subjetiv
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