151 research outputs found

    Cloning, characterisation and comparative analysis of a starch synthase IV gene in wheat: functional and evolutionary implications

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    <p>Abstract</p> <p>Background</p> <p>Starch is of great importance to humans as a food and biomaterial, and the amount and structure of starch made in plants is determined in part by starch synthase (SS) activity. Five SS isoforms, SSI, II, III, IV and Granule Bound SSI, have been identified, each with a unique catalytic role in starch synthesis. The basic mode of action of SSs is known; however our knowledge of several aspects of SS enzymology at the structural and mechanistic level is incomplete. To gain a better understanding of the differences in SS sequences that underscore their specificity, the previously uncharacterised <it>SSIVb </it>from wheat was cloned and extensive bioinformatics analyses of this and other SSs sequences were done.</p> <p>Results</p> <p>The wheat SSIV cDNA is most similar to rice <it>SSIVb </it>with which it shows synteny and shares a similar exon-intron arrangement. The wheat <it>SSIVb </it>gene was preferentially expressed in leaf and was not regulated by a circadian clock. Phylogenetic analysis showed that in plants, SSIV is closely related to SSIII, while SSI, SSII and Granule Bound SSI clustered together and distinctions between the two groups can be made at the genetic level and included chromosomal location and intron conservation. Further, identified differences at the amino acid level in their glycosyltransferase domains, predicted secondary structures, global conformations and conserved residues might be indicative of intragroup functional associations.</p> <p>Conclusion</p> <p>Based on bioinformatics analysis of the catalytic region of 36 SSs and 3 glycogen synthases (GSs), it is suggested that the valine residue in the highly conserved K-X-G-G-L motif in SSIII and SSIV may be a determining feature of primer specificity of these SSs as compared to GBSSI, SSI and SSII. In GBSSI, the Ile485 residue may partially explain that enzyme's unique catalytic features. The flexible 380s Loop in the starch catalytic domain may be important in defining the specificity of action for each different SS and the G-X-G in motif VI could define SSIV and SSIII action particularly.</p

    Transnational social capital: the socio‐spatialities of civil society

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    Civil society remains a contested concept, but one that is widely embedded in global development processes. Transnationalism within civil society scholarship is often described dichotomously, either through hierarchical dependency relations or as a more amorphous networked global civil society. These two contrasting spatial imaginaries produce very particular ideas about how transnational relations contribute to civil society. Drawing on empirical material from research with civil society organizations in Barbados and Grenada, in this article I contend that civil society groups use forms of transnational social capital in their work. This does not, however, resonate with the horizontal relations associated with grassroots globalization or vertical chains of dependence. These social relations are imbued with power and agency and are entangled in situated historical, geographical and personal contexts. I conclude that the diverse transnational social relations that are part of civil society activity offer hope and possibilities for continued civil society action in these unexpected spatial arrangements

    Wider sampling reveals a non-sister relationship for geographically contiguous lineages of a marine mussel

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    The accuracy of phylogenetic inference can be significantly improved by the addition of more taxa and by increasing the spatial coverage of sampling. In previous studies, the brown mussel Perna perna showed a sister-lineage relationship between eastern and western individuals contiguously distributed along the South African coastline. We used mitochondrial (COI) and nuclear (ITS) sequence data to further analyze phylogeographic patterns within P.perna. Significant expansion of the geographical coverage revealed an unexpected pattern. The western South African lineage shared the most recent common ancestor (MRCA) with specimens from Angola, Venezuela, and Namibia, whereas eastern South African specimens and Mozambique grouped together, indicating a non-sister relationship for the two South African lineages. Two plausible biogeographic scenarios to explain their origin were both supported by the hypotheses-testing analysis. One includes an Indo-Pacific origin for P.perna, dispersal into the Mediterranean and Atlantic through the Tethys seaway, followed by recent secondary contact after southward expansion of the western and eastern South African lineages. The other scenario (Out of South Africa) suggests an ancient vicariant divergence of the two lineages followed by their northward expansion. Nevertheless, the Out of South Africa hypothesis would require a more ancient divergence between the two lineages. Instead, our estimates indicated that they diverged very recently (310 kyr), providing a better support for an Indo-Pacific origin of the two South African lineages. The arrival of the MRCA of P.perna in Brazil was estimated at 10 [0-40] kyr. Thus, the hypothesis of a recent introduction in Brazil through hull fouling in wooden vessels involved in the transatlantic itineraries of the slave trade did not receive strong support, but given the range for this estimate, it could not be discarded. Wider geographic sampling of marine organisms shows that lineages with contiguous distributions need not share a common ancestry.Portuguese National Science Foundation (FCT) [EXPL/BIA-BIC/1471/2012]; South Africa Research Chairs Initiative (SARChI) of the Department of Science and Technologyinfo:eu-repo/semantics/publishedVersio

    Educational Disparities in Rates of Smoking Among Diabetic Adults: The Translating Research Into Action for Diabetes Study

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    Objectives. We assessed educational disparities in smoking rates among adults with diabetes in managed care settings. Methods. We used a cross-sectional, survey-based (2002–2003) observational study among 6538 diabetic patients older than 25 years across multiple managed care health plans and states. For smoking at each level of self-reported educational attainment, predicted probabilities were estimated by means of hierarchical logistic regression models with random intercepts for health plan, adjusted for potential confounders. Results. Overall, 15% the participants reported current smoking. An educational gradient in smoking was observed that varied significantly (P<.003) across age groups, with the educational gradient being strong in those aged 25 to 44 years, modest in those aged 45 to 64 years, and nonexistent in those aged 65 years or older. Of particular note, the prevalence of smoking observed in adults aged 25–44 years with less than a high school education was 50% (95% confidence interval: 36% to 63%). Conclusions. Approximately half of poorly educated young adults with diabetes smoke, magnifying the health risk associated with early-onset diabetes. Targeted public health interventions for smoking prevention and cessation among young, poorly educated people with diabetes are needed

    Physical activity and optimal self-rated health of adults with and without diabetes

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    <p>Abstract</p> <p>Background</p> <p>Regular physical activity can improve people's overall health and contribute to both primary and secondary prevention of many chronic diseases and conditions including diabetes. The aim of this study was to examine the association between levels of physical activity and optimal self-rated health (SRH) of U.S. adults with and without diabetes in all 50 states and territories of the Unites States.</p> <p>Methods</p> <p>We estimated the prevalence of optimal SRH by diabetes status of 430,912 adults aged 18 years and older who participated in the 2007 state-based survey of the Behavioral Risk Factor Surveillance System (BRFSS). Prevalence ratios were produced with multivariate Cox regression models using levels of physical activity as a predictor and status of optimal SRH as an outcome variable while controlling for sociodemographic and behavioral health risk factors.</p> <p>Results</p> <p>The prevalence of reporting optimal SRH was 53.3%, 52.2%, and 86.2% for adults with type 1 diabetes, type 2 diabetes, and without diabetes, respectively. Also in the aforementioned order, adults who reported being active had an increased likelihood of 81%, 32%, and 18% for reporting optimal SRH, when compared with adults who reported being inactive.</p> <p>Conclusions</p> <p>Regular physical activity of adults, particularly adults with diabetes, is associated with optimal SRH. The findings of this study underscore the importance of advising and motivating adults with diabetes so that physical activity can be integrated into their lifestyle for diabetes care. Additionally, a population-based effort to promote physical activity in communities may benefit adults in general by improving their overall health and well-being.</p

    The lung cancer exercise training study: a randomized trial of aerobic training, resistance training, or both in postsurgical lung cancer patients: rationale and design

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    <p>Abstract</p> <p>Background</p> <p>The Lung Cancer Exercise Training Study (LUNGEVITY) is a randomized trial to investigate the efficacy of different types of exercise training on cardiorespiratory fitness (VO<sub>2peak</sub>), patient-reported outcomes, and the organ components that govern VO<sub>2peak </sub>in post-operative non-small cell lung cancer (NSCLC) patients.</p> <p>Methods/Design</p> <p>Using a single-center, randomized design, 160 subjects (40 patients/study arm) with histologically confirmed stage I-IIIA NSCLC following curative-intent complete surgical resection at Duke University Medical Center (DUMC) will be potentially eligible for this trial. Following baseline assessments, eligible participants will be randomly assigned to one of four conditions: (1) aerobic training alone, (2) resistance training alone, (3) the combination of aerobic and resistance training, or (4) attention-control (progressive stretching). The ultimate goal for all exercise training groups will be 3 supervised exercise sessions per week an intensity above 70% of the individually determined VO<sub>2peak </sub>for aerobic training and an intensity between 60 and 80% of one-repetition maximum for resistance training, for 30-45 minutes/session. Progressive stretching will be matched to the exercise groups in terms of program length (i.e., 16 weeks), social interaction (participants will receive one-on-one instruction), and duration (30-45 mins/session). The primary study endpoint is VO<sub>2peak</sub>. Secondary endpoints include: patient-reported outcomes (PROs) (e.g., quality of life, fatigue, depression, etc.) and organ components of the oxygen cascade (i.e., pulmonary function, cardiac function, skeletal muscle function). All endpoints will be assessed at baseline and postintervention (16 weeks). Substudies will include genetic studies regarding individual responses to an exercise stimulus, theoretical determinants of exercise adherence, examination of the psychological mediators of the exercise - PRO relationship, and exercise-induced changes in gene expression.</p> <p>Discussion</p> <p>VO<sub>2peak </sub>is becoming increasingly recognized as an outcome of major importance in NSCLC. LUNGEVITY will identify the optimal form of exercise training for NSCLC survivors as well as provide insight into the physiological mechanisms underlying this effect. Overall, this study will contribute to the establishment of clinical exercise therapy rehabilitation guidelines for patients across the entire NSCLC continuum.</p> <p>Trial Registration</p> <p>NCT00018255</p

    Educational disparities in health behaviors among patients with diabetes: the Translating Research Into Action for Diabetes (TRIAD) Study

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    <p>Abstract</p> <p>Background</p> <p>Our understanding of social disparities in diabetes-related health behaviors is incomplete. The purpose of this study was to determine if having less education is associated with poorer diabetes-related health behaviors.</p> <p>Methods</p> <p>This observational study was based on a cohort of 8,763 survey respondents drawn from ~180,000 patients with diabetes receiving care from 68 provider groups in ten managed care health plans across the United States. Self-reported survey data included individual educational attainment ("education") and five diabetes self-care behaviors among individuals for whom the behavior would clearly be indicated: foot exams (among those with symptoms of peripheral neuropathy or a history of foot ulcers); self-monitoring of blood glucose (SMBG; among insulin users only); smoking; exercise; and certain diabetes-related health seeking behaviors (use of diabetes health education, website, or support group in last 12 months). Predicted probabilities were modeled at each level of self-reported educational attainment using hierarchical logistic regression models with random effects for clustering within health plans.</p> <p>Results</p> <p>Patients with less education had significantly lower predicted probabilities of being a non-smoker and engaging in regular exercise and health-seeking behaviors, while SMBG and foot self-examination did not vary by education. Extensive adjustment for patient factors revealed no discernable confounding effect on the estimates or their significance, and most education-behavior relationships were similar across sex, race and other patient characteristics. The relationship between education and smoking varied significantly across age, with a strong inverse relationship in those aged 25–44, modest for those ages 45–64, but non-evident for those over 65. Intensity of disease management by the health plan and provider communication did not alter the examined education-behavior relationships. Other measures of socioeconomic position yielded similar findings.</p> <p>Conclusion</p> <p>The relationship between educational attainment and health behaviors was modest in strength for most behaviors. Over the life course, the cumulative effect of reduced practice of multiple self-care behaviors among less educated patients may play an important part in shaping the social health gradient.</p
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