9,724 research outputs found

    Chlorination and oxidation of heparin and hyaluronan by hypochlorous acid and hypochlorite anions: effect of sulfate groups on reaction pathways and kinetics.

    Get PDF
    Hypochlorous acid (HOCl), produced in inflammatory conditions by the enzyme myeloperoxidase, and its anion hypochlorite (OCl(-)) exist in vivo at almost equal concentrations. Their reactions with hyaluronan and heparin (as a model for sulfated glycosaminoglycans in the extracellular matrix) have been studied as a function of pH. The major product in these reactions is the chloramide derivative of the glycosaminoglycans. Spectral, chloramide yield, and kinetic measurements show sharply contrasting behavior of heparin and hyaluronan and the data allow the calculation of second-order rate constants for the reactions of both HOCl and OCl(-) for all reaction pathways leading to the formation of chloramides and also oxidation products. By comparison with hyaluronan, it can be demonstrated that both N-sulfate and O-sulfate groups in heparin influence the proportions of these pathways in this glycosaminoglycan. Evidence is also given for further oxidation pathways involving a reaction of HOCl with the chloramide product of hyaluronan but not with heparin. The significance of these results for the mechanisms of inflammation, particularly for fragmentation of extracellular matrix glycosaminoglycans, is discussed

    “Don’t confuse me with facts”—how right wing populism affects trust in agencies advocating anthropogenic climate change as a reality

    Get PDF
    Everyday public denial of anthropogenically caused climate change (ACC) has complex antecedents and exists on both individual and institutional levels. Earlier research has linked ACC denial to opposition to formal science and elites, perceived threats to the industrialist capitalist order and existing system properties. Research also suggest that trust in public organizations is a key factor in determining support or opposition to climate change policies. In this paper, we explore the possibility that right wing populism and anti-elitist attitudes fuel both ACC denial and low trust in environmental institutions. We surveyed a representative sample of Norwegians (N = 3032) to measure ACC denial, how denial is linked to socio-demographic characteristics, trust in environmental institutions, attitudes toward elites and immigration, as well as environmental attitude orientations. Results show that lack of trust in environmental institutions is strongly associated with ACC denial, and furthermore that the degree of trust—or lack thereof—is partly a function of anti-elitist attitudes, opposition to migration and views of nature

    Enabling the Twin Transitions: Digital Technologies Support Environmental Sustainability through Lean Principles

    Get PDF
    Manufacturing companies seek innovative approaches to achieve successful Green and Digital transitions, where adopting lean production is one alternative. However, further investigation is required to formulate the approach with empirical inputs and identify what digital technologies could be applied with which lean principles for environmental benefits. Therefore, this study first conducted a case study in three companies to collect empirical data. A complementary literature review was then carried out, investigating the existing frameworks, and complementing practices of digitalized lean implementations and the resulting environmental impact. Consequently, the Internet of Things and related connection-level technologies were identified as the key facilitators in lean implementations, specifically in visualization, communication, and poka-yoke, leading to environmental benefits. Furthermore, a framework of DIgitalization Supports Environmental sustainability through Lean principles (DISEL) was proposed to help manufacturing companies identify the opportunities of digitalizing lean principles for Environmental sustainability, thus enabling the twin transitions and being resilient

    Selective expansion of viral variants following experimental transmission of a reconstituted feline immunodeficiency virus quasispecies

    Get PDF
    Following long-term infection with virus derived from the pathogenic GL8 molecular clone of feline immunodeficiency virus (FIV), a range of viral variants emerged with distinct modes of interaction with the viral receptors CD134 and CXCR4, and sensitivities to neutralizing antibodies. In order to assess whether this viral diversity would be maintained following subsequent transmission, a synthetic quasispecies was reconstituted comprising molecular clones bearing envs from six viral variants and its replicative capacity compared in vivo with a clonal preparation of the parent virus. Infection with either clonal (Group 1) or diverse (Group 2) challenge viruses, resulted in a reduction in CD4+ lymphocytes and an increase in CD8+ lymphocytes. Proviral loads were similar in both study groups, peaking by 10 weeks post-infection, a higher plateau (set-point) being achieved and maintained in study Group 1. Marked differences in the ability of individual viral variants to replicate were noted in Group 2; those most similar to GL8 achieved higher viral loads while variants such as the chimaeras bearing the B14 and B28 Envs grew less well. The defective replication of these variants was not due to suppression by the humoral immune response as virus neutralising antibodies were not elicited within the study period. Similarly, although potent cellular immune responses were detected against determinants in Env, no qualitative differences were revealed between animals infected with either the clonal or the diverse inocula. However, in vitro studies indicated that the reduced replicative capacity of variants B14 and B28 in vivo was associated with altered interactions between the viruses and the viral receptor and co-receptor. The data suggest that viral variants with GL8-like characteristics have an early, replicative advantage and should provide the focus for future vaccine development

    Modulation of the virus-receptor interaction by mutations in the V5 loop of feline immunodeficiency virus (FIV) following in vivo escape from neutralising antibody

    Get PDF
    <b>BACKGROUND:</b> In the acute phase of infection with feline immunodeficiency virus (FIV), the virus targets activated CD4+ T cells by utilising CD134 (OX40) as a primary attachment receptor and CXCR4 as a co-receptor. The nature of the virus-receptor interaction varies between isolates; strains such as GL8 and CPGammer recognise a "complex" determinant on CD134 formed by cysteine-rich domains (CRDs) 1 and 2 of the molecule while strains such as PPR and B2542 require a more "simple" determinant comprising CRD1 only for infection. These differences in receptor recognition manifest as variations in sensitivity to receptor antagonists. In this study, we ask whether the nature of the virus-receptor interaction evolves in vivo.<p></p> <b>RESULTS:</b> Following infection with a homogeneous viral population derived from a pathogenic molecular clone, a quasispecies emerged comprising variants with distinct sensitivities to neutralising antibody and displaying evidence of conversion from a "complex" to a "simple" interaction with CD134. Escape from neutralising antibody was mediated primarily by length and sequence polymorphisms in the V5 region of Env, and these alterations in V5 modulated the virus-receptor interaction as indicated by altered sensitivities to antagonism by both anti-CD134 antibody and soluble CD134.<p></p> <b>CONCLUSIONS:</b> The FIV-receptor interaction evolves under the selective pressure of the host humoral immune response, and the V5 loop contributes to the virus-receptor interaction. Our data are consistent with a model whereby viruses with distinct biological properties are present in early versus late infection and with a shift from a "complex" to a "simple" interaction with CD134 with time post-infection.<p></p&gt

    Age-related differences in adaptation during childhood: The influences of muscular power production and segmental energy flow caused by muscles

    Get PDF
    Acquisition of skillfulness is not only characterized by a task-appropriate application of muscular forces but also by the ability to adapt performance to changing task demands. Previous research suggests that there is a different developmental schedule for adaptation at the kinematic compared to the neuro-muscular level. The purpose of this study was to determine how age-related differences in neuro-muscular organization affect the mechanical construction of pedaling at different levels of the task. By quantifying the flow of segmental energy caused by muscles, we determined the muscular synergies that construct the movement outcome across movement speeds. Younger children (5-7 years; n = 11), older children (8-10 years; n = 8), and adults (22-31 years; n = 8) rode a stationary ergometer at five discrete cadences (60, 75, 90, 105, and 120 rpm) at 10% of their individually predicted peak power output. Using a forward dynamics simulation, we determined the muscular contributions to crank power, as well as muscular power delivered to the crank directly and indirectly (through energy absorption and transfer) during the downstroke and the upstroke of the crank cycle. We found significant age × cadence interactions for (1) peak muscular power at the hip joint [Wilks' Lambda = 0.441, F(8,42) = 2.65, p = 0.019] indicating that at high movement speeds children produced less peak power at the hip than adults, (2) muscular power delivered to the crank during the downstroke and the upstroke of the crank cycle [Wilks' Lambda = 0.399, F(8,42) = 3.07, p = 0.009] indicating that children delivered a greater proportion of the power to the crank during the upstroke when compared to adults, (3) hip power contribution to limb power [Wilks' Lambda = 0.454, F(8,42) = 2.54, p = 0.023] indicating a cadence-dependence of age-related differences in the muscular synergy between hip extensors and plantarflexors. The results demonstrate that in spite of a successful performance, children construct the task of pedaling differently when compared to adults, especially when they are pushed to their performance limits. The weaker synergy between hip extensors and plantarflexors suggests that a lack of inter-muscular coordination, rather than muscular power production per se, is a factor that limits children's performance ranges

    Making AUVs Truly Autonomous

    Get PDF

    Failure of a non-authorized copy product to maintain response achieved with imatinib in a patient with chronic phase chronic myeloid leukemia: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Due to high rates of response and durable remissions, imatinib (Glivec<sup>®</sup>, or Gleevec<sup>®</sup> in the USA; Novartis Pharma AG) is the standard of care in patients with chronic myeloid leukemia. Recently, a non-authorized product which claims comparability to imatinib has become available.</p> <p>Case presentation</p> <p>This report describes the loss of response in a 36-year-old male patient with chronic-phase chronic myeloid leukemia who had previously been in full hematologic and cytogenetic remission and partial molecular remission for three years, under treatment with brand-name imatinib of 400 mg per day. Before the initiation of treatment with a copy product, imatib (CIPLA-India), the patient had negative BCR-ABL status. Within three months of initiation of treatment with the copy product, the patient's BCR-ABL status became positive, with substantial decreases noted in white blood cell counts, red blood cell counts and platelet counts. Conversion of the BCR-ABL status to negative and improvements in hematologic parameters were achieved when the brand medication, imatinib, was resumed at a dose of 600 mg per day.</p> <p>Conclusion</p> <p>In our patient, the substitution of a copy product for imatinib resulted in the rapid loss of a previously stable response, with the risk of progression to life-threatening accelerated phase or blast crisis phase of the disease. Without supportive clinical evidence of efficacy and safety of imatib (or any other copy product) caution should be used when substituting imatinib in the treatment of any patient with chronic myeloid leukemia.</p

    Field-study science classrooms as positive and enjoyable learning environments

    Get PDF
    We investigated differences between field-study classrooms and traditional science classrooms in terms of the learning environment and students’ attitudes to science, as well as the differential effectiveness of field-study classrooms for students differing in sex and English proficiency. A modified version of selected scales from the What Is Happening In this Class? questionnaire was used to assess the learning environment, whereas students’ attitudes were assessed with a shortened version of a scale from the Test of Science Related Attitudes. A sample of 765 grade 5 students from 17 schools responded to the learning environment and attitude scales in terms of both their traditional science classrooms and classrooms at a field-study centre in Florida. Large effect sizes supported the effectiveness of the field-studies classroom in terms of both the learning environment and student attitudes. Relative to the home school science class, the field-study class was considerably more effective for students with limited English proficiency than for native English speakers
    corecore