897 research outputs found

    Interactions Between 'Trichostrongylus colubriformis' and 'Trichostrongylus vitrinus'

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    'Trichostrongylus colubriformis' and 'T. vitrinus' are nematodes infecting the small intestine of ruminants, mainly sheep and goats. These species are closely related and can occur simultaneously in the same host. Despite such similarities anecdotal evidence suggests proportions of these two species tend to vary greatly between regions, between paddocks in the same region and between sheep in the same paddock. Of the two species, 'T. vitrinus' is known to be more pathogenic making it desirable to know what influences differences in species proportion to possibly manipulate the environment and, therefore, species proportion, or to more accurately predict abundance of 'T. vitrinus'. Factors considered were; anthelmintic treatment, host nutrition, host resistance status, interspecific competition and temperature. In order to study factors affecting species proportion a reliable method of species identification was necessary to distinguish between the eggs, larvae and females of the two species. A variety of possible techniques were reviewed before a DNA based species identification technique, using the second internal transcribed spacer of ribosomal DNA, was chosen. To investigate effects of anthelmintic treatment on species proportion, experiments were conducted on nematode populations from two properties. This work showed that after exposure to a range of anthelmintics, 'T. colubriformis' and 'T. vitrinus' can develop different levels of resistance to these anthelmintics. Results also confirmed that species proportion varied significantly between regions and between sheep in the same paddock

    The Radon Signed Cumulative Distribution Transform and its applications in classification of Signed Images

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    Here we describe a new image representation technique based on the mathematics of transport and optimal transport. The method relies on the combination of the well-known Radon transform for images and a recent signal representation method called the Signed Cumulative Distribution Transform. The newly proposed method generalizes previous transport-related image representation methods to arbitrary functions (images), and thus can be used in more applications. We describe the new transform, and some of its mathematical properties and demonstrate its ability to partition image classes with real and simulated data. In comparison to existing transport transform methods, as well as deep learning-based classification methods, the new transform more accurately represents the information content of signed images, and thus can be used to obtain higher classification accuracies. The implementation of the proposed method in Python language is integrated as a part of the software package PyTransKit, available on Github

    Deliberative Democracy in the EU. Countering Populism with Participation and Debate. CEPS Paperback

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    Elections are the preferred way to freely transfer power from one term to the next and from one political party or coalition to another. They are an essential element of democracy. But if the process of power transfer is corrupted, democracy risks collapse. Reliance on voters, civil society organisations and neutral observers to fully exercise their freedoms as laid down in international human rights conventions is an integral part of holding democratic elections. Without free, fair and regular elections, liberal democracy is inconceivable. Elections are no guarantee that democracy will take root and hold, however. If the history of political participation in Europe over the past 800 years is anything to go by, successful attempts at gaining voice have been patchy, while leaders’ attempts to silence these voices and consolidate their own power have been almost constant (Blockmans, 2020). Recent developments in certain EU member states have again shown us that democratically elected leaders will try and use majoritarian rule to curb freedoms, overstep the constitutional limits of their powers, protect the interests of their cronies and recycle themselves through seemingly free and fair elections. In their recent book How Democracies Die, two Harvard professors of politics write: “Since the end of the Cold War, most democratic breakdowns have been caused not by generals and soldiers but by elected governments themselves” (Levitsky and Ziblatt, 2018)

    Relevance of human metapneumovirus in exacerbations of COPD

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    BACKGROUND AND METHODS: Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR. RESULTS: We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 Ă— 10(5 )viral copies/ml in nasal lavage and 1.88 Ă— 10(5 )viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD. CONCLUSION: HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely

    Limitations in the use of PSMÎł, agr , RNAIII, and biofilm formation as biomarkers to define invasive Staphylococcus epidermidis from chronic biomedical device-associated infections

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    Staphylococcus epidermidis is a common cause of biomedical device-associated infections. Agr is the major quorum sensing system in staphylococci and regulates virulence factors. Four agr-specificity groups exist in S. epidermidis, and chronic S. epidermidis infections are hypothesised to select for agr-negative phenotypes. Therefore, we investigated S. epidermidis strains from prosthetic joint- and catheter-associated infections to establish i) whether an infection selects for an agr-negative phenotype; ii) the importance of PSMÎł and iii) if the agr-specificity group is infection dependent. S. epidermidis nasal isolates from healthy volunteers were used as controls. The distribution of agr-specificity groups was significantly different between infection and control episodes, but did not distinguish between the infection types. PSMÎł secretion was used to determine agr-activity and HPLC analysis showed that 44% of prosthetic and 32% of catheter-associated episodes produced no PSMÎł in comparison to 8% of the control strains. However, PSMÎł expression did not always correlate with RNAIII up-regulation, indicating that PSMÎł synthesis is likely influenced by additional post-transcriptional control. The data suggests chronic S. epidermidis infections favour agr-specificity group 1 but the results suggest that they do not select for an agr-negative phenotype. Further studies are required to explore the mechanisms underlying the selection and survival of these S. epidermidis phenotypes isolated from biomedical device-associated infections

    The Reliability of Global and Hemispheric Surface Temperature Records

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    The purpose of this review article is to discuss the development and associated estimation of uncertainties in the global and hemispheric surface temperature records. The review begins by detailing the groups that produce surface temperature datasets. After discussing the reasons for similarities and differences between the various products, the main issues that must be addressed when deriving accurate estimates, particularly for hemispheric and global averages, are then considered. These issues are discussed in the order of their importance for temperature records at these spatial scales: biases in SST data, particularly before the 1940s; the exposure of land-based thermometers before the development of louvred screens in the late 19th century; and urbanization effects in some regions in recent decades. The homogeneity of land-based records is also discussed; however, at these large scales it is relatively unimportant. The article concludes by illustrating hemispheric and global temperature records from the four groups that produce series in near-real time

    The structure of mercantile communities in the Roman world : how open were Roman trade networks?

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    PIP5KIβ Selectively Modulates Apical Endocytosis in Polarized Renal Epithelial Cells

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    Localized synthesis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at clathrin coated pits (CCPs) is crucial for the recruitment of adaptors and other components of the internalization machinery, as well as for regulating actin dynamics during endocytosis. PtdIns(4,5)P2 is synthesized from phosphatidylinositol 4-phosphate by any of three phosphatidylinositol 5-kinase type I (PIP5KI) isoforms (α, β or γ). PIP5KIβ localizes almost exclusively to the apical surface in polarized mouse cortical collecting duct cells, whereas the other isoforms have a less polarized membrane distribution. We therefore investigated the role of PIP5KI isoforms in endocytosis at the apical and basolateral domains. Endocytosis at the apical surface is known to occur more slowly than at the basolateral surface. Apical endocytosis was selectively stimulated by overexpression of PIP5KIβ whereas the other isoforms had no effect on either apical or basolateral internalization. We found no difference in the affinity for PtdIns(4,5)P2-containing liposomes of the PtdIns(4,5)P2 binding domains of epsin and Dab2, consistent with a generic effect of elevated PtdIns(4,5)P2 on apical endocytosis. Additionally, using apical total internal reflection fluorescence imaging and electron microscopy we found that cells overexpressing PIP5KIβ have fewer apical CCPs but more internalized coated structures than control cells, consistent with enhanced maturation of apical CCPs. Together, our results suggest that synthesis of PtdIns(4,5)P2 mediated by PIP5KIβ is rate limiting for apical but not basolateral endocytosis in polarized kidney cells. PtdIns(4,5)P2 may be required to overcome specific structural constraints that limit the efficiency of apical endocytosis. © 2013 Szalinski et al

    Serum homocysteine is weakly associated with von Willebrand factor and soluble vascular cell adhesion molecule 1, but not with C-reactive protein in type 2 diabetic and nondiabetic subjects: the Hoorn Study.

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    Background: Hyperhomocysteinaemia may constitute an independent risk factor for cardiovascular disease, but it is still unclear by which pathophysiological mechanisms homocysteine (tHcy) may promote atherothrombosis. The aim of this study was firstly to examine whether tHcy is associated with endothelial dysfunction, increased adherence of leukocytes, and/or chronic low-grade inflammation, as estimated from plasma levels of von Willebrand factor (vWf), soluble vascular cell adhesion molecule 1 (sVCAM-1) and C-reactive protein (CRP), respectively. Secondly we investigated whether the presence of type 2 diabetes modifies these associations. Materials and Methods: Six hundred and ten subjects of a general population of middle-aged and elderly subjects, 170 of whom had type 2 diabetes, participated in this cross-sectional study. Linear regression analyses were used to study whether tHcy was associated with vWf, sVCAM-1 and CRP, and whether the presence of diabetes modified these associations. Results: After adjustment for confounders, tHcy was significantly but weakly associated with vWf (β=0·15, P=0·05) and sVCAM-1 (β=0·082, P=0·04). tHcy was not significantly associated with CRP (β=0·02, P=0·91). The presence of diabetes did not significantly modify these associations. Conclusions: This study provides evidence that tHcy is, at most, weakly associated with endothelial dysfunction as estimated from plasma vWf, and with leukocyte adhesion as estimated from plasma sVCAM-1. tHcy was not significantly associated with chronic low-grade inflammation as estimated from plasma CRP. Our data thus suggest that the link between tHcy and atherothrombosis cannot be explained by associations of tHcy with vWf, sVCAM-1 or CRP
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