2,046 research outputs found

    Krill (Euphausia superba) distribution contracts southward during rapid regional warming

    Get PDF
    High-latitude ecosystems are among the fastest warming on the planet1. Polar species may be sensitive to warming and ice loss, but data are scarce and evidence is conflicting2,3,4. Here, we show that, within their main population centre in the southwest Atlantic sector, the distribution of Euphausia superba (hereafter, ‘krill’) has contracted southward over the past 90 years. Near their northern limit, numerical densities have declined sharply and the population has become more concentrated towards the Antarctic shelves. A concomitant increase in mean body length reflects reduced recruitment of juvenile krill. We found evidence for environmental controls on recruitment, including a reduced density of juveniles following positive anomalies of the Southern Annular Mode. Such anomalies are associated with warm, windy and cloudy weather and reduced sea ice, all of which may hinder egg production and the survival of larval krill5. However, the total post-larval density has declined less steeply than the density of recruits, suggesting that survival rates of older krill have increased. The changing distribution is already perturbing the krill-centred food web6 and may affect biogeochemical cycling7,8. Rapid climate change, with associated nonlinear adjustments in the roles of keystone species, poses challenges for the management of valuable polar ecosystems3

    Prescribing practices of primary-care veterinary practitioners in dogs diagnosed with bacterial pyoderma

    Get PDF
    Concern has been raised regarding the potential contributions of veterinary antimicrobial use to increasing levels of resistance in bacteria critically important to human health. Canine pyoderma is a frequent, often recurrent diagnosis in pet dogs, usually attributable to secondary bacterial infection of the skin. Lesions can range in severity based on the location, total area and depth of tissue affected and antimicrobial therapy is recommended for resolution. This study aimed to describe patient signalment, disease characteristics and treatment prescribed in a large number of UK, primary-care canine pyoderma cases and to estimate pyoderma prevalence in the UK vet-visiting canine population

    Ensemble-Based Computational Approach Discriminates Functional Activity of p53 Cancer and Rescue Mutants

    Get PDF
    The tumor suppressor protein p53 can lose its function upon single-point missense mutations in the core DNA-binding domain (“cancer mutants”). Activity can be restored by second-site suppressor mutations (“rescue mutants”). This paper relates the functional activity of p53 cancer and rescue mutants to their overall molecular dynamics (MD), without focusing on local structural details. A novel global measure of protein flexibility for the p53 core DNA-binding domain, the number of clusters at a certain RMSD cutoff, was computed by clustering over 0.7 µs of explicitly solvated all-atom MD simulations. For wild-type p53 and a sample of p53 cancer or rescue mutants, the number of clusters was a good predictor of in vivo p53 functional activity in cell-based assays. This number-of-clusters (NOC) metric was strongly correlated (r2 = 0.77) with reported values of experimentally measured ΔΔG protein thermodynamic stability. Interpreting the number of clusters as a measure of protein flexibility: (i) p53 cancer mutants were more flexible than wild-type protein, (ii) second-site rescue mutations decreased the flexibility of cancer mutants, and (iii) negative controls of non-rescue second-site mutants did not. This new method reflects the overall stability of the p53 core domain and can discriminate which second-site mutations restore activity to p53 cancer mutants

    Symphysiotomy in Zimbabwe; Postoperative Outcome, Width of the Symphysis Joint, and Knowledge, Attitudes and Practice among Doctors and Midwives

    Get PDF
    BACKGROUND: Obstructed labour remains one of the leading causes of maternal and foetal death and morbidity in poorly resourced areas of the world, where the 24 hours availability of a caesarean section (CS) cannot be guaranteed, and the CS related mortality rate is still high. In these settings, reinstatement of symphysiotomy has been advocated. The objectives were, in1994; to study perioperative and long-term complications of symphysiotomy and compare them to those related to CS for similar indications, in 1996; to measure the symphyseal width after symphysiotomy and compare it to that after normal vaginal delivery, and, in 1998; to assess knowledge, attitudes and practice related to symphysiotomy among doctors and midwives in Zimbabwe. METHODS AND FINDINGS: Thirty-four women who had undergone symphysiotomy and 29 women who had undergone a CS for obstructed labour were interviewed. The symphyseal widths of 19 women with a previous symphysiotomy were compared to that of 92 women with previous normal vaginal deliveries, using ultrasound technique. Forty-one doctors and 39 midwives, in three central hospitals and seven district hospitals in Zimbabwe, were interviewed about symphysiotomy. None of the 34 women reported serious soft tissue injuries or infections post symphysiotomy. Long-term complications after symphysiotomy do not differ notably from those after CS for similar indications. The intra-articular width of the symphysis pubis is increased after a symphysiotomy. Seventy-nine of the 80 interviewed health care workers knew about symphysiotomy. One obstetrician had performed symphysiotomies. Two-thirds of the participants considered symphysiotomy an obsolete and second-class operation, but lifesaving and appropriate in remote areas of Zimbabwe. Ten of 13 midwives in remote areas wanted to carry out symphysiotomies themselves. CONCLUSIONS: No severe complications due to symphysiotomy were revealed in this study. The results suggest that a modest permanent enlargement of the pelvis post symphysiotomy (together with the absence of a scarred uterus) may facilitate subsequent vaginal delivery. Doctors and midwives working in district hospitals have a more positive attitude to symphysiotomies than the colleagues in central hospitals. Obstetricians (who would have to do the teaching), working in the large urban hospitals almost exclude symphysiotomy as an alternative management in Zimbabwe

    Intestine-Specific, Oral Delivery of Captopril/Montmorillonite: Formulation and Release Kinetics

    Get PDF
    The intercalation of captopril (CP) into the interlayers of montmorillonite (MMT) affords an intestine-selective drug delivery system that has a captopril-loading capacity of up to ca. 14 %w/w and which exhibits near-zero-order release kinetics

    Behavior and Impact of Zirconium in the Soil–Plant System: Plant Uptake and Phytotoxicity

    Get PDF
    Because of the large number of sites they pollute, toxic metals that contaminate terrestrial ecosystems are increasingly of environmental and sanitary concern (Uzu et al. 2010, 2011; Shahid et al. 2011a, b, 2012a). Among such metals is zirconium (Zr), which has the atomic number 40 and is a transition metal that resembles titanium in physical and chemical properties (Zaccone et al. 2008). Zr is widely used in many chemical industry processes and in nuclear reactors (Sandoval et al. 2011; Kamal et al. 2011), owing to its useful properties like hardness, corrosion-resistance and permeable to neutrons (Mushtaq 2012). Hence, the recent increased use of Zr by industry, and the occurrence of the Chernobyl and Fukashima catastrophe have enhanced environmental levels in soil and waters (Yirchenko and Agapkina 1993; Mosulishvili et al. 1994 ; Kruglov et al. 1996)
    corecore