213 research outputs found

    A 'resource allocator' for transcription based on a highly fragmented T7 RNA polymerase

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    Synthetic genetic systems share resources with the host, including machinery for transcription and translation. Phage RNA polymerases (RNAPs) decouple transcription from the host and generate high expression. However, they can exhibit toxicity and lack accessory proteins (σ factors and activators) that enable switching between different promoters and modulation of activity. Here, we show that T7 RNAP (883 amino acids) can be divided into four fragments that have to be co‐expressed to function. The DNA‐binding loop is encoded in a C‐terminal 285‐aa ‘σ fragment’, and fragments with different specificity can direct the remaining 601‐aa ‘core fragment’ to different promoters. Using these parts, we have built a resource allocator that sets the core fragment concentration, which is then shared by multiple σ fragments. Adjusting the concentration of the core fragment sets the maximum transcriptional capacity available to a synthetic system. Further, positive and negative regulation is implemented using a 67‐aa N‐terminal ‘α fragment’ and a null (inactivated) σ fragment, respectively. The α fragment can be fused to recombinant proteins to make promoters responsive to their levels. These parts provide a toolbox to allocate transcriptional resources via different schemes, which we demonstrate by building a system which adjusts promoter activity to compensate for the difference in copy number of two plasmids.United States. Office of Naval Research (N00014‐13‐1‐0074)National Institutes of Health (U.S.) (5R01GM095765)National Science Foundation (U.S.) (Synthetic Biology Engineering Research Center (SA5284‐11210))United States. Dept. of Defense (National Defense Science and Engineering Graduate Fellowship (NDSEG) Program))Hertz Foundation (Fellowship

    Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity

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    Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria

    Relaxin, a pleiotropic vasodilator for the treatment of heart failure

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    Relaxin is a naturally occurring peptide hormone that plays a central role in the hemodynamic and renovascular adaptive changes that occur during pregnancy. Triggering similar changes could potentially be beneficial in the treatment of patients with heart failure. The effects of relaxin include the production of nitric oxide, inhibition of endothelin, inhibition of angiotensin II, production of VEGF, and production of matrix metalloproteinases. These effects lead to systemic and renal vasodilation, increased arterial compliance, and other vascular changes. The recognition of this has led to the study of relaxin for the treatment of heart failure. An initial pilot study has shown favorable hemodynamic effects in patients with heart failure, including reduction in ventricular filling pressures and increased cardiac output. The ongoing RELAX-AHF clinical program is designed to evaluate the effects of relaxin on the symptoms and outcomes in a large group of patients admitted to hospital for acute heart failure. This review will summarize both the biology of relaxin and the data supporting its potential efficacy in human heart failure

    Moth biomass increases and decreases over 50 years in Britain

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    Steep insect biomass declines ('insectageddon') have been widely reported, despite a lack of continuously collected biomass data from replicated long-term monitoring sites. Such severe declines are not supported by the world’s longest running insect population database: annual moth biomass estimates from British fixed monitoring sites revealed increasing biomass between 1967 and 1982, followed by gradual decline from 1982 to 2017, with a 2.2-fold net gain in mean biomass between the first (1967–1976) and last decades (2008–2017) of monitoring. High between-year variability and multi-year periodicity in biomass emphasize the need for long-term data to detect trends and identify their causes robustly

    Sarcopenia Exacerbates Obesity-Associated Insulin Resistance and Dysglycemia: Findings from the National Health and Nutrition Examination Survey III

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    Sarcopenia often co-exists with obesity, and may have additive effects on insulin resistance. Sarcopenic obese individuals could be at increased risk for type 2 diabetes. We performed a study to determine whether sarcopenia is associated with impairment in insulin sensitivity and glucose homeostasis in obese and non-obese individuals.We performed a cross-sectional analysis of National Health and Nutrition Examination Survey III data utilizing subjects of 20 years or older, non-pregnant (N = 14,528). Sarcopenia was identified from bioelectrical impedance measurement of muscle mass. Obesity was identified from body mass index. Outcomes were homeostasis model assessment of insulin resistance (HOMA IR), glycosylated hemoglobin level (HbA1C), and prevalence of pre-diabetes (6.0≀ HbA1C<6.5 and not on medication) and type 2 diabetes. Covariates in multiple regression were age, educational level, ethnicity and sex.Sarcopenia was associated with insulin resistance in non-obese (HOMA IR ratio 1.39, 95% confidence interval (CI) 1.26 to 1.52) and obese individuals (HOMA-IR ratio 1.16, 95% CI 1.12 to 1.18). Sarcopenia was associated with dysglycemia in obese individuals (HbA1C ratio 1.021, 95% CI 1.011 to 1.043) but not in non-obese individuals. Associations were stronger in those under 60 years of age. We acknowledge that the cross-sectional study design limits our ability to draw causal inferences.Sarcopenia, independent of obesity, is associated with adverse glucose metabolism, and the association is strongest in individuals under 60 years of age, which suggests that low muscle mass may be an early predictor of diabetes susceptibility. Given the increasing prevalence of obesity, further research is urgently needed to develop interventions to prevent sarcopenic obesity and its metabolic consequences

    Evaluating Promotional Approaches for Citizen Science Biological Recording: Bumblebees as a Group Versus Harmonia axyridis as a Flagship for Ladybirds

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    Over the past decade, the number of biological records submitted by members of the public have increased dramatically. However, this may result in reduced record quality, depending on how species are promoted in the media. Here we examined the two main promotional approaches for citizen science recording schemes: flagship-species, using one charismatic species as an umbrella for the entire group (here, Harmonia axyridis (Pallas) for Coleoptera: Coccinellidae), and general-group, where the group is promoted as a whole and no particular prominence is given to any one species (here, bumblebees, genus Bombus (Hymenoptera: Apidae)). Of the two approaches, the general-group approach produced data that was not biased towards any one species, but far fewer records per year overall. In contrast, the flagship-species approach generated a much larger annual dataset, but heavily biased towards the flagship itself. Therefore, we recommend that the approach for species promotion is fitted to the result desired

    Physiological Correlates of Endurance Time Variability during Constant-Workrate Cycling Exercise in Patients with COPD

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    RATIONALE: The endurance time (T(end)) during constant-workrate cycling exercise (CET) is highly variable in COPD. We investigated pulmonary and physiological variables that may contribute to these variations in T(end). METHODS: Ninety-two patients with COPD completed a CET performed at 80% of peak workrate capacity (W(peak)). Patients were divided into tertiles of T(end) [Group 1: <4 min; Group 2: 4-6 min; Group 3: >6 min]. Disease severity (FEV(1)), aerobic fitness (W(peak), peak oxygen consumption [VO2(peak)], ventilatory threshold [VO2(VT)]), quadriceps strength (MVC), symptom scores at the end of CET and exercise intensity during CET (heart rate at the end of CET to heart rate at peak incremental exercise ratio [HR(CET)/HR(peak)]) were analyzed as potential variables influencing T(end). RESULTS: W(peak), VO2(peak), VO2(VT), MVC, leg fatigue at end of CET, and HR(CET)/HR(peak) were lower in group 1 than in group 2 or 3 (p≀0.05). VO2(VT) and leg fatigue at end of CET independently predicted T(end) in multiple regression analysis (r = 0.50, p = 0.001). CONCLUSION: T(end) was independently related to the aerobic fitness and to tolerance to leg fatigue at the end of exercise. A large fraction of the variability in T(end) was not explained by the physiological parameters assessed in the present study. Individualization of exercise intensity during CET should help in reducing variations in T(end) among patients with COPD

    Parental education and perception of outdoor playing time for preschoolers

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    Abstract Aim: The objective of this study was to analyze whether or not socioeconomic positions influence outdoor playtime during the week (WK) and on the weekends (WEND). Methods: The sample consisted of 485 (girls; n=223) healthy preschoolers, aged from 3 to 6 years, enrolled in kindergartens from the metropolitan area of Porto, Portugal. Physical Activity (PA) was assessed for 7 consecutive days with an accelerometer. The time playing outdoors during the WK or the WEND was reported by parents. Anthropometric data (weight and height) was collected following standardized protocols. Socioeconomic position was assessed by Parental Education (PE), according to the Portuguese education system. Results: We found differences in time spent playing outdoors either for the WK or WEND, but not for Total PA (TPA), in both sexes. However, regression analysis showed that after age adjustment, BMI and TPA for both sexes, we only found significant associations between low PE (LPE) and high PE (HPE) groups on WK or WEND. However, we found no statistically significant association for boys on the WK (p=0.06). Conclusion: Our findings suggest that socioeconomic position can influence the children’s time spent in outdoor activities, especially on the weekends. This may have implications for future interventions with this age group

    More than 75 percent decline over 27 years in total flying insect biomass in protected areas

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    Global declines in insects have sparked wide interest among scientists, politicians, and the general public. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxonomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape

    Aplastic anemia associated with interferon alpha 2a in a patient with chronic hepatitis C virus infection: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hepatitis-associated aplastic anemia is a common syndrome in patients with bone marrow failure. However, hepatitis-associated aplastic anemia is an immune-mediated disease that does not appear to be caused by any of the known hepatitis viruses including hepatitis C virus. In addition, to the best of our knowledge there are no reported cases of patients with chronic hepatitis C virus infection developing aplastic anemia associated with pegylated interferon alpha 2a treatment.</p> <p>Case presentation</p> <p>We report the case of a 46-year-old Greek man who developed severe aplastic anemia during treatment with pegylated interferon alpha 2a for chronic hepatitis C virus infection. He presented with generalized purpura and bruising, as well as pallor of the skin and mucous membranes. His blood tests showed pancytopenia. He underwent allogeneic bone marrow transplantation after completing two courses of immunosuppressive therapy with antithymocyte globulin and cyclosporin A.</p> <p>Conclusions</p> <p>The combination of a specific environmental precipitant represented by the hepatitis C virus infection, an altered metabolic detoxification pathway due to treatment with pegylated interferon alpha 2a and a facilitating genetic background such as polymorphism in metabolic detoxification pathways and specific human leukocyte antigen genes possibly conspired synergistically in the development of aplastic anemia in this patient. Our case clearly shows that the causative role of pegylated interferon alpha 2a in the development of aplastic anemia must not be ignored.</p
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