1,955 research outputs found

    Microplastics in the Antarctic marine system: An emerging area of research

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    It was thought that the Southern Ocean was relatively free of microplastic contamination; however, recent studies and citizen science projects in the Southern Ocean have reported microplastics in deep-sea sediments and surface waters. Here we reviewed available information on microplastics (including macroplastics as a source of microplastics) in the Southern Ocean. We estimated primary microplastic concentrations from personal care products and laundry, and identified potential sources and routes of transmission into the region. Estimates showed the levels of microplastic pollution released into the region from ships and scientific research stations were likely to be negligible at the scale of the Southern Ocean, but may be significant on a local scale. This was demonstrated by the detection of the first microplastics in shallow benthic sediments close to a number of research stations on King George Island. Furthermore, our predictions of primary microplastic concentrations from local sources were five orders of magnitude lower than levels reported in published sampling surveys (assuming an even dispersal at the ocean surface). Sea surface transfer from lower latitudes may contribute, at an as yet unknown level, to Southern Ocean plastic concentrations. Acknowledging the lack of data describing microplastic origins, concentrations, distribution and impacts in the Southern Ocean, we highlight the urgent need for research, and call for routine, standardised monitoring in the Antarctic marine system

    Palaeobiogeographical perspectives on pinus pinea, a controversial and enigmatic mediterranean pine

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    The origins of some species of economic importance occurring over the Mediterranean Basin have been a traditional matter of debate that has important implications for land management. The case of Pinus pinea L. (Stone pine) is probably one of the most controversial, due to its documented long-term interaction with humans and its presence as a symbolic tree in certain areas of the Mediterranean (e.g., southwestern Iberia and Tuscany). Among the rest of the Mediterranean pines, several features make this pine unique (it has a characteristic crown shape, an edible kernel, cones that require three years to mature, and a very depauperate genetic diversity across its range). In addition, its palaeoecological information is rather limited, as the taxonomic precision attained by pollen analysts is insufficient for this tree and macroremains (such as kernels or anatomically well preserved wood) are needed to unequivocally detect the species in the fossil record. Recent findings of macrofossils of Pinus pinea in inland Iberia (Duero Basin) extend the late- Holocene range of the species, but the palaeobiogeographical information and the exhaustive genetic data available still suggest a very limited natural area (but still not sufficiently well defined) and a long and intense history of linkage to humans

    CTP promotes efficient ParB-dependent DNA condensation by facilitating one-dimensional diffusion from parS

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    Faithful segregation of bacterial chromosomes relies on the ParABS partitioning system and the SMC complex. In this work, we used single-molecule techniques to investigate the role of cytidine triphosphate (CTP) binding and hydrolysis in the critical interaction between centromere-like parS DNA sequences and the ParB CTPase. Using a combined optical tweezers confocal microscope, we observe the specific interaction of ParB with parS directly. Binding around parS is enhanced by the presence of CTP or the non-hydrolysable analogue CTPγS. However, ParB proteins are also detected at a lower density in distal non-specific DNA. This requires the presence of a parS loading site and is prevented by protein roadblocks, consistent with one-dimensional diffusion by a sliding clamp. ParB diffusion on non-specific DNA is corroborated by direct visualization and quantification of movement of individual quantum dot labelled ParB. Magnetic tweezers experiments show that the spreading activity, which has an absolute requirement for CTP binding but not hydrolysis, results in the condensation of parS-containing DNA molecules at low nanomolar protein concentrations

    Monitoring of the Fall Armyworm (Spodoptera frugiperda Walker) Moth for the Determination of Efficient Chemical Control in Zea mays L.

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    Objective: To determine the population dynamics of the fall armyworm (FAW), identify the critical period of highest infestation and to determine the number of agrochemicals applications for its control. Design/methodology/approach: A monitoring and capture of male FAW moths was conducted using plastic traps with sexual attraction pheromones. A daily count of captured moths was performed during the crop season, the data were plotted to determine the period of highest infestation and the optimal timing for chemical control. Additionally, the number of insecticide applications for FAW control was evaluated, with treatments including none (T0), one (T1), two (T2), three (T3), and four (T4) applications. A randomized complete block design with nine repetitions was used. Before each application, the number of plants with visible damage and its intensity were counted using the Davis visual scale. Statistical analysis of the measured variables was conducted. Results: The results showed that moths were evenly distributed across the planted surface, and two periods of higher infestation were identified: between 32 to 35 and 70 to 76 days after planting, respectively. The biological cycle of the FAW was between 38 to 41 days. The analysis of variance showed statistical differences (p ≤ 0.001) among the treatments. Findings/conclusions: Using plastic traps with sexual attraction pheromones is an efficient method for capturing, monitoring, reducing the population, estimate the length of the biological cycle, and identifying the highest infestation period of the FAW. Moreover, two insecticide applications during the periods of highest infestation resulted in optimal control of FAW

    Good practice regarding smoking cessation management in Spain: Challenges and opportunities for primary care physicians and nurses

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    INTRODUCTION We analyze the activities carried out by primary care (PC) physicians and nurses with respect to smoking cessation and evaluate their self-reported training, knowledge, and behavior. METHODS A cross-sectional study was conducted including 1514 PC physicians and nurses from June 2016 to March 2017, in Spain. The main variable was Good Practice (GP) in attention to smokers. To identify associated factors, a multilevel logistic regression model was used adjusted for sex, age, type of center, contract, years of employment, tobacco consumption, and self-reported training/knowledge. RESULTS Of the 792 physicians and 722 nurses, 48.6% referred to GP in smoking cessation management. The finding related to: being a non-smoker (OR=1.8; 95% CI: 1.2-2.5) or ex-smoker (OR= 1.4; 95% CI: 1.02-2.1), having a good level of knowledge (OR=1.8; 95% CI: 1.3-2.4) and training (OR=2.4; 95% CI: 1.8-3.2), and, to a lesser extent, being female (OR=1.3; 95% CI: 1.03-1.7), and work experience >10 years (OR=1.4; 95% CI: 1.03-1.9). The main GP barriers were: lack of time (45.5%), organizational problems (48.4%), and 35.4% lack of training. CONCLUSIONS The GP of PC physicians and nurses regarding smoking cessation management is related to being non-smokers or ex-smokers, and having sufficient training and knowledge. Lack of time and organizational problems were considered to be the main barriers. The promotion of training activities in the Spanish National Health Service with the support of scientific societies is required

    Efficient Excitation of Channel Plasmons in Tailored, UV-Lithography-Defined V-Grooves

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    [Image: see text] We demonstrate the highly efficient (>50%) conversion of freely propagating light to channel plasmon-polaritons (CPPs) in gold V-groove waveguides using compact 1.6 μm long waveguide-termination coupling mirrors. Our straightforward fabrication process, involving UV-lithography and crystallographic silicon etching, forms the coupling mirrors innately and ensures exceptional-quality, wafer-scale device production. We tailor the V-shaped profiles by thermal silicon oxidation in order to shift initially wedge-located modes downward into the V-grooves, resulting in well-confined CPPs suitable for nanophotonic applications

    Lack of validation of genetic variants associated with anti-tumor necrosis factor therapy response in rheumatoid arthritis: a genome-wide association study replication and meta-analysis

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    Introduction: In this study, our aim was to elucidate the role of four polymorphisms identified in a prior large genome-wide association study (GWAS) in which the investigators analyzed the responses of patients with rheumatoid arthritis (RA) to treatment with tumor necrosis factor inhibitors (TNFi). The authors of that study reported that the four genetic variants were significantly associated. However, none of the associations reached GWAS significance, and two subsequent studies failed to replicate these associations. Methods: The four polymorphisms (rs12081765, rs1532269, rs17301249 and rs7305646) were genotyped in a total of 634 TNFi-treated RA patients of Spanish Caucasian origin. Four outcomes were evaluated: changes in the Disease Activity Score in 28 joints (DAS28) after 6 and 12 months of treatment and classification according to the European League Against Rheumatism (EULAR) response criteria at the same time points. Association with DAS28 changes was assessed by linear regression using an additive genetic model. Contingency tables of genotype and allele frequencies between EULAR responder and nonresponder patients were compared. In addition, we combined our data with those of previously reported studies in a meta-analysis including 2,998 RA patients. Results: None of the four genetic variants showed an association with response to TNFi in any of the four outcomes analyzed in our Spanish patients. In addition, only rs1532269 yielded a suggestive association (P = 0.0033) with the response to TNFi when available data from previous studies were combined in the meta-analysis. Conclusion: Our data suggest that the rs12081765, rs1532269, rs17301249 and rs7305646 genetic variants do not have a role as genetic predictors of TNFi treatment outcomes
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