38 research outputs found

    Subcellular discharge of a serine protease mediates release of invasive malaria parasites from host erythrocytes.

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    The most virulent form of malaria is caused by waves of replication of blood stages of the protozoan pathogen Plasmodium falciparum. The parasite divides within an intraerythrocytic parasitophorous vacuole until rupture of the vacuole and host-cell membranes releases merozoites that invade fresh erythrocytes to repeat the cycle. Despite the importance of merozoite egress for disease progression, none of the molecular factors involved are known. We report that, just prior to egress, an essential serine protease called PfSUB1 is discharged from previously unrecognized parasite organelles (termed exonemes) into the parasitophorous vacuole space. There, PfSUB1 mediates the proteolytic maturation of at least two essential members of another enzyme family called SERA. Pharmacological blockade of PfSUB1 inhibits egress and ablates the invasive capacity of released merozoites. Our findings reveal the presence in the malarial parasitophorous vacuole of a regulated, PfSUB1-mediated proteolytic processing event required for release of viable parasites from the host erythrocyte

    The purple line as a measure of labour progress: a longitudinal study

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    Background: Vaginal examination (VE) and assessment of the cervix is currently considered to be the gold standard for assessment of labour progress. It is however inherently imprecise with studies indicating an overall accuracy for determining the diameter of the cervix at between 48-56%. Furthermore, VEs can be unpleasant, intrusive and embarrassing for women, and are associated with the risk of introducing infection. In light of increasing concern world wide about the use of routine interventions in labour it may be time to consider alternative, less intrusive means of assessing progress in labour. The presence of a purple line during labour, seen to rise from the anal margin and extend between the buttocks as labour progresses has been reported. The study described in this paper aimed to assess in what percentage of women in labour a purple line was present, clear and measurable and to determine if any relationship existed between the length of the purple line and cervical dilatation and/or station of the fetal head. Methods: This longitudinal study observed 144 women either in spontaneous labour (n=112) or for induction of labour (n=32) from admission through to final VE. Women were examined in the lateral position and midwives recorded the presence or absence of the line throughout labour immediately before each VE. Where present, the length of the line was measured using a disposable tape measure. Within subjects correlation, chi-squared test for independence, and independent samples t-test were used to analyse the data. Results: The purple line was seen at some point in labour for 109 women (76%). There was a medium positive correlation between length of the purple line and cervical dilatation (r=+0.36, n=66, P=0.0001) and station of the fetal head (r=+0.42, n=56, P<0.0001). Conclusions: The purple line does exist and there is a medium positive correlation between its length and both cervical dilatation and station of the fetal head. Where the line is present, it may provide a useful guide for clinicians of labour progress along side other measures. Further research is required to assess whether measurement of the line is acceptable to women in labour and also clinicians

    Prioritization of knowledge-needs to achieve best practices for bottom trawling in relation to seabed habitats

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    Management and technical approaches that achieve a sustainable level of fish production while at the same time minimizing or limiting the wider ecological effects caused through fishing gear contact with the seabed might be considered to be ‘best practice’. To identify future knowledge-needs that would help to support a transition towards the adoption of best practices for trawling, a prioritization exercise was undertaken with a group of 39 practitioners from the seafood industry and management, and 13 research scientists who have an active research interest in bottom-trawl and dredge fisheries. A list of 108 knowledge-needs related to trawl and dredge fisheries was developed in conjunction with an ‘expert task force’. The long list was further refined through a three stage process of voting and scoring, including discussions of each knowledge-need. The top 25 knowledge-needs are presented, as scored separately by practitioners and scientists. There was considerable consistency in the priorities identified by these two groups. The top priority knowledge-need to improve current understanding on the distribution and extent of different habitat types also reinforced the concomitant need for the provision and access to data on the spatial and temporal distribution of all forms of towed bottom-fishing activities. Many of the other top 25 knowledge-needs concerned the evaluation of different management approaches or implementation of different fishing practices, particularly those that explore trade-offs between effects of bottom trawling on biodiversity and ecosystem services and the benefits of fish production as food.Fil: Kaiser, Michel J.. Bangor University; Reino UnidoFil: Hilborn, Ray. University of Washington; Estados UnidosFil: Jennings, Simon. Fisheries and Aquaculture Science; Reino UnidoFil: Amaroso, Ricky. University of Washington; Estados UnidosFil: Andersen, Michael. Danish Fishermen; DinamarcaFil: Balliet, Kris. Sustainable Fisheries Partnership; Estados UnidosFil: Barratt, Eric. Sanford Limited; Nueva ZelandaFil: Bergstad, Odd A. Institute of Marine Research; NoruegaFil: Bishop, Stephen. Independent Fisheries Ltd; Nueva ZelandaFil: Bostrom, Jodi L. Marine Stewardship Council; Reino UnidoFil: Boyd, Catherine. Clearwater Seafoods; CanadáFil: Bruce, Eduardo A. Friosur S.A.; ChileFil: Burden, Merrick. Marine Conservation Alliance; Estados UnidosFil: Carey, Chris. Independent Fisheries Ltd.; Estados UnidosFil: Clermont, Jason. New England Aquarium; Estados UnidosFil: Collie, Jeremy S. University of Rhode Island,; Estados UnidosFil: Delahunty, Antony. National Federation of Fishermen; Reino UnidoFil: Dixon, Jacqui. Pacific Andes International Holdings Limited; ChinaFil: Eayrs, Steve. Gulf of Maine Research Institute; Estados UnidosFil: Edwards, Nigel. Seachill Ltd.; Reino UnidoFil: Fujita, Rod. Environmental Defense Fund; Reino UnidoFil: Gauvin, John. Alaska Seafood Cooperative; Estados UnidosFil: Gleason, Mary. The Nature Conservancy; Estados UnidosFil: Harris, Brad. Alaska Pacific University; Estados UnidosFil: He, Pingguo. University of Massachusetts Dartmouth; Estados UnidosFil: Hiddink, Jan G. Bangor University; Reino UnidoFil: Hughes, Kathryn M. Bangor University; Reino UnidoFil: Inostroza, Mario. EMDEPES; ChileFil: Kenny, Andrew. Fisheries and Aquaculture Science; Reino UnidoFil: Kritzer, Jake. Environmental Defense Fund; Estados UnidosFil: Kuntzsch, Volker. Sanford Limited; Estados UnidosFil: Lasta, Mario. Diag. Montegrande N° 7078. Mar del Plata; ArgentinaFil: Lopez, Ivan. Confederacion Española de Pesca; EspañaFil: Loveridge, Craig. South Pacific Regional Fisheries Management Organisation; Nueva ZelandaFil: Lynch, Don. Gorton; Estados UnidosFil: Masters, Jim. Marine Conservation Society; Reino UnidoFil: Mazor, Tessa. CSIRO Marine and Atmospheric Research; AustraliaFil: McConnaughey, Robert A. US National Marine Fisheries Service; Estados UnidosFil: Moenne, Marcel. Pacificblu; ChileFil: Francis. Marine Scotland Science; Reino UnidoFil: Nimick, Aileen M. Alaska Pacific University; Estados UnidosFil: Olsen, Alex. A. Espersen; DinamarcaFil: Parker, David. Young; Reino UnidoFil: Parma, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Penney, Christine. Clearwater Seafoods; CanadáFil: Pierce, David. Massachusetts Division of Marine Fisheries; Estados UnidosFil: Pitcher, Roland. CSIRO Marine and Atmospheric Research; AustraliaFil: Pol, Michael. Massachusetts Division of Marine Fisheries; Estados UnidosFil: Richardson, Ed. Pollock Conservation Cooperative; Estados UnidosFil: Rijnsdorp, Adriaan D. Wageningen IMARES; Países BajosFil: Rilatt, Simon. A. Espersen; DinamarcaFil: Rodmell, Dale P. National Federation of Fishermen's Organisations; Reino UnidoFil: Rose, Craig. FishNext Research; Estados UnidosFil: Sethi, Suresh A. Alaska Pacific University; Estados UnidosFil: Short, Katherine. F.L.O.W. Collaborative; Nueva ZelandaFil: Suuronen, Petri. Fisheries and Aquaculture Department; ItaliaFil: Taylor, Erin. New England Aquarium; Estados UnidosFil: Wallace, Scott. The David Suzuki Foundation; CanadáFil: Webb, Lisa. Gorton's Inc.; Estados UnidosFil: Wickham, Eric. Unit four –1957 McNicoll Avenue; CanadáFil: Wilding, Sam R. Monterey Bay Aquarium; Estados UnidosFil: Wilson, Ashley. Department for Environment; Reino UnidoFil: Winger, Paul. Memorial University Of Newfoundland; CanadáFil: Sutherland, William J. University of Cambridge; Reino Unid

    White matter hyperintensities and normal-appearing white matter integrity in the aging brain

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    AbstractWhite matter hyperintensities (WMH) of presumed vascular origin are a common finding in brain magnetic resonance imaging of older individuals and contribute to cognitive and functional decline. It is unknown how WMH form, although white matter degeneration is characterized pathologically by demyelination, axonal loss, and rarefaction, often attributed to ischemia. Changes within normal-appearing white matter (NAWM) in subjects with WMH have also been reported but have not yet been fully characterized. Here, we describe the in vivo imaging signatures of both NAWM and WMH in a large group of community-dwelling older people of similar age using biomarkers derived from magnetic resonance imaging that collectively reflect white matter integrity, myelination, and brain water content. Fractional anisotropy (FA) and magnetization transfer ratio (MTR) were significantly lower, whereas mean diffusivity (MD) and longitudinal relaxation time (T1) were significantly higher, in WMH than NAWM (p < 0.0001), with MD providing the largest difference between NAWM and WMH. Receiver operating characteristic analysis on each biomarker showed that MD differentiated best between NAWM and WMH, identifying 94.6% of the lesions using a threshold of 0.747 × 10−9 m2s−1 (area under curve, 0.982; 95% CI, 0.975–0.989). Furthermore, the level of deterioration of NAWM was strongly associated with the severity of WMH, with MD and T1 increasing and FA and MTR decreasing in NAWM with increasing WMH score, a relationship that was sustained regardless of distance from the WMH. These multimodal imaging data indicate that WMH have reduced structural integrity compared with surrounding NAWM, and MD provides the best discriminator between the 2 tissue classes even within the mild range of WMH severity, whereas FA, MTR, and T1 only start reflecting significant changes in tissue microstructure as WMH become more severe

    Qualitative Behavioural Assessment as a Method to Identify Potential Stressors during Commercial Sheep Transport

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    Land transport is an unavoidable experience for most livestock, yet there is limited research comparing animal welfare under different conditions. We video recorded sheep responses during short (2 h) commercial road transport journeys. Using Qualitative Behavioural Assessment, observers (blinded to the treatments) scored the behavioural expression of sheep and reached significant consensus in their scoring patterns (p &lt; 0.001). There were also significant effects of vehicle crate design (sheep transported in a &#8216;standard&#8217; crate were more calm/relaxed than those transported in a &#8216;convertible&#8217; crate), deck position (sheep on upper decks were more curious/alert than those on lower decks), and sheep breed (fat-tail sheep were more agitated/distressed than merino sheep) on observer scores. We only found marginal differences for sheep originating from feedlot or saleyard. Significant effects of vehicle driver (included as a random factor in all but one of our analyses) suggest driving patterns contributed to demeanour of the sheep. Finally, the fourteen drivers who participated in the study were asked their opinions on livestock transport; none of the factors we tested were identified by drivers as important for sheep welfare during transport. This study supports the use of qualitative measures in transport and revealed differences that could inform truck design

    Qualitative Behavioural Assessment as a Method to Identify Potential Stressors during Commercial Sheep Transport

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    Land transport is an unavoidable experience for most livestock, yet there is limited research comparing animal welfare under different conditions. We video recorded sheep responses during short (2 h) commercial road transport journeys. Using Qualitative Behavioural Assessment, observers (blinded to the treatments) scored the behavioural expression of sheep and reached significant consensus in their scoring patterns (p &lt; 0.001). There were also significant effects of vehicle crate design (sheep transported in a &#8216;standard&#8217; crate were more calm/relaxed than those transported in a &#8216;convertible&#8217; crate), deck position (sheep on upper decks were more curious/alert than those on lower decks), and sheep breed (fat-tail sheep were more agitated/distressed than merino sheep) on observer scores. We only found marginal differences for sheep originating from feedlot or saleyard. Significant effects of vehicle driver (included as a random factor in all but one of our analyses) suggest driving patterns contributed to demeanour of the sheep. Finally, the fourteen drivers who participated in the study were asked their opinions on livestock transport; none of the factors we tested were identified by drivers as important for sheep welfare during transport. This study supports the use of qualitative measures in transport and revealed differences that could inform truck design
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