874 research outputs found

    Latest climate models confirm need for urgent mitigation

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    Many recently updated climate models show greater future warming than previously. Separate lines of evidence suggest that their warming rates may be unrealistically high, but the risk of such eventualities only emphasizes the need for rapid and deep reductions in emissions

    Stringent mitigation substantially reduces risk of unprecedented near-term warming rates

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    Following the Paris Agreement, many countries are enacting targets to achieve net-zero GHG emissions. Stringent mitigation will have clear societal benefits in the second half of this century by limiting peak warming and stabilizing climate. However, the near-term benefits of mitigation are generally thought to be less clear because forced surface temperature trends can be masked by internal variability. Here we use observationally constrained projections from the latest comprehensive climate models and a simple climate model emulator to show that pursuing stringent mitigation consistent with holding long-term warming below 1.5 °C reduces the risk of unprecedented warming rates in the next 20 years by a factor of 13 compared with a no mitigation scenario, even after accounting for internal variability. Therefore, in addition to long-term benefits, stringent mitigation offers substantial near-term benefits by offering societies and ecosystems a greater chance to adapt to and avoid the worst climate change impacts

    Motivators for uptake and maintenance of exercise: perceptions of long-term stroke survivors and implications for design of exercise programmes.

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    PURPOSE: Exercise-after-stroke programmes are increasingly being provided to encourage more physical exercise among stroke survivors, but little is known about what motivates people with stroke to participate in them. This research aimed to identify factors that motivate long-term stroke survivors to exercise, and the implications for programme design. METHODS: In two separate studies, focus groups and individual interviews were used to investigate the views of long-term stroke survivors on exercise and participating in exercise programmes. Their data were analysed thematically, and the findings of the studies were synthesised. RESULTS: Eleven stroke survivors and two partners took part in two focus groups; six other stroke survivors (one with a partner) were interviewed individually. Factors reported to influence motivation were the psychological benefits of exercise, a desire to move away from a medicalised approach to exercise, beliefs about stroke recovery, and on-going support to sustain commitment. A number of potential implications of these themes for exercise programme design were identified. CONCLUSIONS: A range of personal beliefs and attitudes and external factors may affect the motivation to exercise, and these vary between individuals. Addressing these factors in the design of exercise programmes for long-term stroke survivors may enhance their appeal and so encourage greater engagement in exercise. IMPLICATIONS FOR REHABILITATION: Exercise programmes may be more attractive to long-term stroke survivors if the psychological well-being benefits of participation are emphasised in their promotion. Some participants will be more attracted by programmes that are de-medicalised, for example, by being located away from clinical settings, and led by or involving suitably-trained non-clinicians. Programmes offered in different formats may attract stroke survivors with different beliefs about the value of exercise in stroke recovery. Programmes should provide explicit support strategies for on-going engagement in exercise.This paper presents independent research funded by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC) for the South West Peninsula. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health in England. The authors report no other declarations of interest

    A genetic contribution from the Far East into Ashkenazi Jews via the ancient Silk Road

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    Contemporary Jews retain a genetic imprint from their Near Eastern ancestry, but obtained substantial genetic components from their neighboring populations during their history. Whether they received any genetic contribution from the Far East remains unknown, but frequent communication with the Chinese has been observed since the Silk Road period. To address this issue, mitochondrial DNA (mtDNA) variation from 55,595 Eurasians are analyzed. The existence of some eastern Eurasian haplotypes in eastern Ashkenazi Jews supports an East Asian genetic contribution, likely from Chinese. Further evidence indicates that this connection can be attributed to a gene flow event that occurred less than 1.4 kilo-years ago (kya), which falls within the time frame of the Silk Road scenario and fits well with historical records and archaeological discoveries. This observed genetic contribution from Chinese to Ashkenazi Jews demonstrates that the historical exchange between Ashkenazim and the Far East was not confined to the cultural sphere but also extended to an exchange of genes

    ICRPfinder: a fast pattern design algorithm for coding sequences and its application in finding potential restriction enzyme recognition sites

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    <p>Abstract</p> <p>Background</p> <p>Restriction enzymes can produce easily definable segments from DNA sequences by using a variety of cut patterns. There are, however, no software tools that can aid in gene building -- that is, modifying wild-type DNA sequences to express the same wild-type amino acid sequences but with enhanced codons, specific cut sites, unique post-translational modifications, and other engineered-in components for recombinant applications. A fast DNA pattern design algorithm, ICRPfinder, is provided in this paper and applied to find or create potential recognition sites in target coding sequences.</p> <p>Results</p> <p>ICRPfinder is applied to find or create restriction enzyme recognition sites by introducing silent mutations. The algorithm is shown capable of mapping existing cut-sites but importantly it also can generate specified new unique cut-sites within a specified region that are guaranteed not to be present elsewhere in the DNA sequence.</p> <p>Conclusion</p> <p>ICRPfinder is a powerful tool for finding or creating specific DNA patterns in a given target coding sequence. ICRPfinder finds or creates patterns, which can include restriction enzyme recognition sites, without changing the translated protein sequence. ICRPfinder is a browser-based JavaScript application and it can run on any platform, in on-line or off-line mode.</p

    Night-time measurements of HOx during the RONOCO project and analysis of the sources of HO2

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    Measurements of the radical species OH and HO2 were made using the fluorescence assay by gas expansion (FAGE) technique during a series of night-time and daytime flights over the UK in summer 2010 and winter 2011. OH was not detected above the instrument's 1σ limit of detection during any of the night-time flights or during the winter daytime flights, placing upper limits on [OH] of 1.8 × 106 molecule cm−3 and 6.4 × 105 molecule cm−3 for the summer and winter flights, respectively. HO2 reached a maximum concentration of 3.2 × 108 molecule cm−3 (13.6 pptv) during a night-time flight on 20 July 2010, when the highest concentrations of NO3 and O3 were also recorded. An analysis of the rates of reaction of OH, O3, and the NO3 radical with measured alkenes indicates that the summer night-time troposphere can be as important for the processing of volatile organic compounds (VOCs) as the winter daytime troposphere. An analysis of the instantaneous rate of production of HO2 from the reactions of O3 and NO3 with alkenes has shown that, on average, reactions of NO3 dominated the night-time production of HO2 during summer and reactions of O3 dominated the night-time HO2 production during winter

    Mitochondrial echoes of first settlement and genetic continuity in El Salvador

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    Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador. Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas. Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade

    Inhibition of Expression in Escherichia coli of a Virulence Regulator MglB of Francisella tularensis Using External Guide Sequence Technology

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    External guide sequences (EGSs) have successfully been used to inhibit expression of target genes at the post-transcriptional level in both prokaryotes and eukaryotes. We previously reported that EGS accessible and cleavable sites in the target RNAs can rapidly be identified by screening random EGS (rEGS) libraries. Here the method of screening rEGS libraries and a partial RNase T1 digestion assay were used to identify sites accessible to EGSs in the mRNA of a global virulence regulator MglB from Francisella tularensis, a Gram-negative pathogenic bacterium. Specific EGSs were subsequently designed and their activities in terms of the cleavage of mglB mRNA by RNase P were tested in vitro and in vivo. EGS73, EGS148, and EGS155 in both stem and M1 EGS constructs induced mglB mRNA cleavage in vitro. Expression of stem EGS73 and EGS155 in Escherichia coli resulted in significant reduction of the mglB mRNA level coded for the F. tularensis mglB gene inserted in those cells

    A Modular Cloning System for Standardized Assembly of Multigene Constructs

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    The field of synthetic biology promises to revolutionize biotechnology through the design of organisms with novel phenotypes useful for medicine, agriculture and industry. However, a limiting factor is the ability of current methods to assemble complex DNA molecules encoding multiple genetic elements in various predefined arrangements. We present here a hierarchical modular cloning system that allows the creation at will and with high efficiency of any eukaryotic multigene construct, starting from libraries of defined and validated basic modules containing regulatory and coding sequences. This system is based on the ability of type IIS restriction enzymes to assemble multiple DNA fragments in a defined linear order. We constructed a 33 kb DNA molecule containing 11 transcription units made from 44 individual basic modules in only three successive cloning steps. This modular cloning (MoClo) system can be readily automated and will be extremely useful for applications such as gene stacking and metabolic engineering
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