298 research outputs found

    Vegetation characterization through the use of precipitation-affected SAR signals

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    Current space-based SAR offers unique opportunities to classify vegetation types and to monitor vegetation growth due to its frequent acquisitions and its sensitivity to vegetation geometry. However, SAR signals also experience frequent temporal fluctuations caused by precipitation events, complicating the mapping and monitoring of vegetation. In this paper, we show that the influence of a priori known precipitation events on the signals can be used advantageously for the classification of vegetation conditions. For this, we exploit the change in Sentinel-1 backscatter response between consecutive acquisitions under varying wetness conditions, which we show is dependent on the state of vegetation. The performance further improves when a priori information on the soil type is taken into account.1010FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2013/50943-

    Hypertrophic obstructive cardiomyopathy in liver transplant patients

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    The optimal treatment strategy for patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM) and end-stage liver disease (ESLD) is not well defined. Although medical management is the accepted first line treatment, patients who are unresponsive to medication require further interventions. Since ESLD patients have a high operative risk for surgical myomectomy, alcohol septal ablation (ASA) emerges as a good alternative in these cases. The timing of ASA in relation to liver transplantation is still unclear. We report here on the first case of an orthotopic liver transplant-recipient undergoing ASA and the second of a cirrhotic patient requiring ASA as a bridge to liver transplantation. Both patients had a good clinical outcome and we argue that ASA in HOCM patients should be driven by symptom onset, and that in the asymptomatic patient it can be safely deferred until after liver transplantation. (Cardiol J 2008; 15: 74-79

    Mercury levels in Southern Ocean squid : variability over the last decade

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    Authors acknowledge the Portuguese Foundation for the Science and Technology (FCT) through a PhD grant to José Seco (SRFH/PD/BD/113487). Acknowledgments are due also to the Integrated Program of SR&TD ‘Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate’ (reference Centro-01-0145-FEDER-000018), co-funded by Centro (2020) program, Portugal 2020, European Union, through the European Regional Development Fund, for personal funding to J.P.Coelho. The IUF (Institut Universitaire de France) is acknowledged for its support to P. Bustamante as a Senior Member. This research was also within José Xavier strategic program of MARE (MARE - UID/MAR/04292/2013). GAT, GS and SF were supported by the Ecosystems programme at the British Antarctic Survey.The concentrations of total and proportions of organic mercury were measured in tissues of 355 individuals of 8 species of Southern Ocean squid (Alluroteuthis antarcticus, Bathyteuthis abyssicola, Filippovia knipovitchi, Galiteuthis glacialis, Gonatus antarcticus, Kondakovia longimana, Psychroteuthis glacialis and Slosarczykovia circumantarctica). Squid were caught around South Georgia (Scotia Sea) during 5 cruises, between the austral summers of 2006/07 to 2016/17 to evaluate temporal changes in bioaccumulation and tissue partitioning. Total mercury concentrations varied between 4 ng g−1 and 804 ng g−1 among all tissues. Net accumulation of mercury in muscle with size was observed in A. antarcticus, B. abyssicola and P. glacialis, but no relationship was found for S. circumantarctica and lower concentrations were observed in larger individuals of G. glacialis. Muscle tissues had the highest mercury concentrations in the majority of species, except for F. knipovitchi for which the digestive gland contained highest concentrations. In terms of the percentage of organic mercury in the tissues, muscle always contained the highest values (67%–97%), followed by the digestive gland (22%–38%). Lowest organic mercury percentages were found consistently in the gills (9%–19%), suggesting only low levels of incorporation through the dissolved pathway and/or a limited redistribution of dietary organic mercury towards this tissue. Overall, results are indicative of a decreasing trend of mercury concentrations in the majority of analysed species over the last decade. As cephalopods are an important Southern Ocean trophic link between primary consumers and top predators, these changes suggest decreasing mercury levels in lower trophic levels and an alleviation of the mercury burden on higher predators that consume squid.PostprintPeer reviewe

    Concomitant prednisone may alleviate methotrexate side-effects in rheumatoid arthritis patients

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    Objectives: To evaluate whether addition of low-moderate dose prednisone to methotrexate (MTX) treatment can alleviate common MTX side-effects in rheumatoid arthritis (RA) patients. Methods: We performed a post-hoc analysis of the CAMERA-II trial which randomized (1:1) 236 early DMARD and prednisone naive RA patients to treatment with MTX + prednisone 10 mg daily, or MTX monotherapy during two years. MTX dose was increased using a treat-to-target approach. We used Generalized Estimating Equations to model the occurrence of common MTX side-effects and of any adverse event over time, controlling for disease activity and MTX dose over time and other possible predictors of adverse events. To assess whether a possible effect was prednisone-specific, we performed the same analysis in the U-ACT-EARLY trial, in which the addition of tocilizumab (TCZ) to MTX was compared to MTX monotherapy in a comparable setting. Results: MTX side-effects were reported at 5.9% of visits in the prednisone-MTX group, compared to 11.2% in the MTX monotherapy group. After controlling for MTX dose and disease activity over time, treatment duration, age, sex, and baseline transaminase levels, addition of prednisone significantly decreased the occurrence of MTX side-effects (OR: 0.54, CI: 0.38–0.77, p = 0.001). Specifically, the occurrence of nausea (OR 0.46, CI: 0.26–0.83, p = 0.009)) and elevated ALT/AST (OR 0.29, CI: 0.17–0.49, p < 0.001) was decreased. There was a trend towards fewer overall adverse events in the prednisone-MTX arm (OR: 0.89, CI: 0.72–1.11, p = 0.30). No difference in MTX side-effects was found between TCZ-MTX and MTX monotherapy in U-ACT-EARLY (OR 1.05, CI: 0.61–1.80, p = 0.87). Conclusion: Addition of 10 mg prednisone daily to MTX treatment in RA patients may ameliorate MTX side-effects, specifically nausea and elevated ALT/AST

    Sustainable Development Policies as Indicators and Pre-Conditions for Sustainability Efforts at Universities: fact or fiction?

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    Purpose - There is a widely held belief that Sustainable Development (SD) policies are essential for universities to successfully engage in matters related to sustainability, and are an indicator of the extent to which they are active in this field. This paper examines the evidence which currently exists to support this assumption. It surveys a sample of universities in Brazil, Germany, Greece, Portugal, South Africa, United Kingdom (UK) and United States of America (USA) to ascertain the extent to which universities that are active in the field of sustainable development have formal policies on sustainable development, and whether such policies are a pre-condition for successful sustainability efforts. Design/methodology/approach –The study involved 35 universities in these seven countries (five universities respectively). A mixed-methods approach has been used, ranging from document analysis, website analysis, questionnaires and interviewing. Findings – Although only 60% of the sampled universities had a policy that specifically addressed SD, this cannot be regarded as an indicator that the remaining 40% are not engaged with substantial actions that address SD. Indeed, all of the universities in the sample, regardless of the existence of a SD formal policy, demonstrated engagement with environmental sustainability policies or procedures in some form or another. This research has been limited by the availability and ability to procure information from the sampled universities. Despite this, it is one of the largest research efforts of this kind ever performed. Originality/value – Our findings provide some valuable insights about the connections between SD policies on the one hand, and the practice of SD in higher education institutions on the other

    Oxidative stress, metabolic activity and mercury concentrations in Antarctic krill Euphausia superba and myctophid fish of the Southern Ocean

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    Authors acknowledge the financial support of the Portuguese Foundation for the Science and Technology (FCT) through PhD grants to José Seco (SRFH/PD/BD/113487), Francesca Coppola (SFRH/BD/118582/2016) and Ângela Almeida (SFRH/BD/110218/2015), and the Portuguese Polar Program PROPOLAR. This study also benefited from the strategic program of MARE (Marine and Environmental Sciences Centre) financed by FCT (UIDB/04292/2020). João Pedro Coelho was funded by the Integrated Program of SR&TD ‘Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate’ (Centro-01-0145-FEDER-000018), co-funded by Centro 2020 program, Portugal 2020 and the European Regional Development Fund. Thanks are due for the financial support to CESAM (UIDB/50017/2020+UIDP/50017/2020) and REQUIMTE (UIDB/50006/2020). The Institut Universitaire de France (IUF) is acknowledged for its support to P. Bustamante as a Senior Member. RAS, SF, GS and GT were supported by the British Antarctic Surveys Ecosystem Programme, which is part of NERC and UKRI.Indicators of oxidative stress and metabolic capacity are key factors in understanding the fitness of wild populations. In the present study, these factors were evaluated in the pelagic Southern Ocean taxa Antarctic krill (Euphausia superba) and myctophid fish (Electrona antarctica, Gymnoscopelus braueri and G. nicholsi) to establish a baseline record for future studies. Mercury (Hg) concentrations were also analysed to evaluate its potential impacts on species biochemical performance. E. superba had higher metabolic activity than most of the myctophid species, which may explain the comparatively lower energy reserves found in the former. The activity of antioxidant enzymes showed, generally, a lower level in E. superba than in the myctophid species. The lack of any relationship between Hg concentrations and organisms' antioxidant and biotransformation defence mechanisms indicate that levels of Hg accumulated in the studied species were not high enough to affect their biochemical processes adversely.PostprintPeer reviewe

    Formin is associated with left-right asymmetry in the pond snail and the frog

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    While components of the pathway that establishes left-right asymmetry have been identified in diverse animals, from vertebrates to flies, it is striking that the genes involved in the first symmetry-breaking step remain wholly unknown in the most obviously chiral animals, the gastropod snails. Previously, research on snails was used to show that left-right signalling of Nodal, downstream of symmetry-breaking, may be an ancestral feature of the Bilateria. Here we report that a disabling mutation in one copy of a tandemly duplicated, diaphanous-related formin is perfectly associated with symmetry-breaking in the pond snail. This is supported by the observation that an anti-formin drug treatment converts dextral snail embryos to a sinistral phenocopy, and in frogs, drug inhibition or over-expression by microinjection of formin has a chirality-randomizing effect in early (pre-cilia) embryos. Contrary to expectations based on existing models, we discovered asymmetric gene expression in 2 and 4 cell snail embryos, preceding morphological asymmetry. As the formin-actin filament has been shown to be part of an asymmetry-breaking switch in vitro, together these results are consistent with the view that animals with diverse bodyplans may derive their asymmetries from the same intracellular chiral elements

    Formin is associated with left-right asymmetry in the pond snail and the frog

    Get PDF
    While components of the pathway that establishes left-right asymmetry have been identified in diverse animals, from vertebrates to flies, it is striking that the genes involved in the first symmetry-breaking step remain wholly unknown in the most obviously chiral animals, the gastropod snails. Previously, research on snails was used to show that left-right signalling of Nodal, downstream of symmetry-breaking, may be an ancestral feature of the Bilateria. Here we report that a disabling mutation in one copy of a tandemly duplicated, diaphanous-related formin is perfectly associated with symmetry-breaking in the pond snail. This is supported by the observation that an anti-formin drug treatment converts dextral snail embryos to a sinistral phenocopy, and in frogs, drug inhibition or over-expression by microinjection of formin has a chirality-randomizing effect in early (pre-cilia) embryos. Contrary to expectations based on existing models, we discovered asymmetric gene expression in 2 and 4 cell snail embryos, preceding morphological asymmetry. As the formin-actin filament has been shown to be part of an asymmetry-breaking switch in vitro, together these results are consistent with the view that animals with diverse bodyplans may derive their asymmetries from the same intracellular chiral elements

    Differential down-modulation of HLA class I and II molecule expression on human tumor cell lines upon in vivo transfer

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    Previous evidence from our laboratory showed that Epstein–Barr virus–immortalized lymphoblastoid B cells undergo a prominent down-modulation of HLA-II molecule expression when injected intraperitoneally in SCID mice, while HLA-I remains almost unaffected. Since this phenomenon can alter the experimental outcome of therapeutic protocols of adoptive cell therapy, we decided to evaluate the behavior of MHC antigens in a panel of cell lines belonging to the B- and T-cell lineages, as well as in epithelial tumor cell lines. Cells were administered in mice either intraperitoneally or subcutaneously and recovered 4 days later for HLA molecule expression analysis. Collected data showed a highly heterogeneous in vivo behavior of the various cell lines, which could alternatively down-modulate, completely abrogate or maintain unchanged the expression of either MHC-I or MHC-II molecules. Moreover, the site of injection impacted differentially on these aspects. Although such phenomena still lack a comprehensive clarification, epigenetic mechanisms are likely to be involved as epigenetic drugs could partially counteract MHC down-modulation in vivo. Nonetheless, it has to be pointed out that careful attention must be paid to the assessment of therapeutic efficacy of translational protocols of adoptive immunotherapy, as modulation of MHC molecules on human target cells when transferred in a mouse environment could readily interfere with the desired and expected therapeutic effects

    Transcriptomic profiling of TK2 deficient human skeletal muscle suggests a role for the p53 signalling pathway and identifies growth and differentiation factor-15 as a potential novel biomarker for mitochondrial myopathies

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    Background Mutations in the gene encoding thymidine kinase 2 (TK2) result in the myopathic form of mitochondrial DNA depletion syndrome which is a mitochondrial encephalomyopathy presenting in children. In order to unveil some of the mechanisms involved in this pathology and to identify potential biomarkers and therapeutic targets we have investigated the gene expression profile of human skeletal muscle deficient for TK2 using cDNA microarrays. Results We have analysed the whole transcriptome of skeletal muscle from patients with TK2 mutations and compared it to normal muscle and to muscle from patients with other mitochondrial myopathies. We have identified a set of over 700 genes which are differentially expressed in TK2 deficient muscle. Bioinformatics analysis reveals important changes in muscle metabolism, in particular, in glucose and glycogen utilisation, and activation of the starvation response which affects aminoacid and lipid metabolism. We have identified those transcriptional regulators which are likely to be responsible for the observed changes in gene expression. Conclusion Our data point towards the tumor suppressor p53 as the regulator at the centre of a network of genes which are responsible for a coordinated response to TK2 mutations which involves inflammation, activation of muscle cell death by apoptosis and induction of growth and differentiation factor 15 (GDF-15) in muscle and serum. We propose that GDF-15 may represent a potential novel biomarker for mitochondrial dysfunction although further studies are required
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