1,346 research outputs found

    Evaluating several satellite precipitation estimates and global ground-based dataset on Sicily (Italy)

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    The developing of satellite-based precipitation retrieval systems, presents great potentialities for several applications ranging from weather and meteorological applications to hydrological modelling. Evaluating performances for these estimates is essential in order to understand their real capabilities and suitability related to each application. In this study an evaluation analysis of satellite precipitation retrieval systems has been carried out for the area of Sicily (Italy). Sicily is an island in the Mediterranean sea with a particular climatology and morphology, which is considered as an interesting test site for satellite precipitation products on the European mid-latitude area. A high density rain-gauges network has been used to evaluate selected satellite precipitation products. Sicily has an area of 26,000 km2 and the gauge density of the network considered in this study is about 250 km2/gauge. Four satellite products (CMORPH, PERSIANN, TMPA-RT, PERSIANN-CCS) along with two adjusted products (TMPA and PERSIANN Adjusted) have been selected for the evaluation. Evaluation and comparisons among selected products is performed with reference to the data provided by the gauge network of Sicily and using statistical and visualization tools. Results show that bias is relevant for all satellite products and climatic considerations are reported to address this issue. Moreover bias errors are observed for the adjusted products even though they are reduced respect to only-satellite products. In order to analyze this result, the ground-based precipitation dataset used by adjusted products (GPCC dataset), has been examined and weaknesses arising from spatial sampling of precipitation process have been identified for the study area. Therefore possible issues deriving from using global ground-based datasets for local scales are pointed out from this application. © 2012 SPIE

    Corporate Philanthropy, Research Networks, and Collaborative Innovation

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    Using a unique dataset of corporate philanthropy, we find that direct giving activities are positively associated with higher levels and more influential, collaborative, and original innovation. In contrast, our results do not hold for corporate foundations’ contributions. Our results suggest that much of what is ostensibly promoted as philanthropy actually reflects research-related networking activities. The effect of direct giving on innovation is more pronounced in more opaque firms and more innovative and competitive industries. These findings provide evidence of the distinct motives by which firms choose between direct giving and foundation giving. Our study suggests that firms can use direct philanthropy to expand firm-boundaries by developing innovation with research partners.postprin

    Elevated hemostasis markers after pneumonia increases one-year risk of all-cause and cardiovascular deaths

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    Background: Acceleration of chronic diseases, particularly cardiovascular disease, may increase long-term mortality after community-acquired pneumonia (CAP), but underlying mechanisms are unknown. Persistence of the prothrombotic state that occurs during an acute infection may increase risk of subsequent atherothrombosis in patients with pre-existing cardiovascular disease and increase subsequent risk of death. We hypothesized that circulating hemostasis markers activated during CAP persist at hospital discharge, when patients appear to have recovered clinically, and are associated with higher mortality, particularly due to cardiovascular causes. Methods: In a cohort of survivors of CAP hospitalization from 28 US sites, we measured D-Dimer, thrombin-antithrombin complexes [TAT], Factor IX, antithrombin, and plasminogen activator inhibitor-1 at hospital discharge, and determined 1-year all-cause and cardiovascular mortality. Results: Of 893 subjects, most did not have severe pneumonia (70.6% never developed severe sepsis) and only 13.4% required intensive care unit admission. At discharge, 88.4% of subjects had normal vital signs and appeared to have clinically recovered. D-dimer and TAT levels were elevated at discharge in 78.8% and 30.1% of all subjects, and in 51.3% and 25.3% of those without severe sepsis. Higher D-dimer and TAT levels were associated with higher risk of all-cause mortality (range of hazard ratios were 1.66-1.17, p = 0.0001 and 1.46-1.04, p = 0.001 after adjusting for demographics and comorbid illnesses) and cardiovascular mortality (p = 0.009 and 0.003 in competing risk analyses). Conclusions: Elevations of TAT and D-dimer levels are common at hospital discharge in patients who appeared to have recovered clinically from pneumonia and are associated with higher risk of subsequent deaths, particularly due to cardiovascular disease. © 2011 Yende et al

    Robust Matrix Completion

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    This paper considers the problem of recovery of a low-rank matrix in the situation when most of its entries are not observed and a fraction of observed entries are corrupted. The observations are noisy realizations of the sum of a low rank matrix, which we wish to recover, with a second matrix having a complementary sparse structure such as element-wise or column-wise sparsity. We analyze a class of estimators obtained by solving a constrained convex optimization problem that combines the nuclear norm and a convex relaxation for a sparse constraint. Our results are obtained for the simultaneous presence of random and deterministic patterns in the sampling scheme. We provide guarantees for recovery of low-rank and sparse components from partial and corrupted observations in the presence of noise and show that the obtained rates of convergence are minimax optimal

    The bone marrow compartment is modified in the absence of galectin-3

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    Galectin-3 (gal-3) is a β-galactoside binding protein present in multivalent complexes with an extracellular matrix and with cell surface glycoconjugates. In this context, it can deliver a variety of intracellular signals to modulate cell activation, differentiation and survival. In the hematopoietic system, it was demonstrated that gal-3 is expressed in myeloid cells and surrounding stromal cells. Furthermore, exogenous and surface gal-3 drive the proliferation of myeloblasts in a granulocyte–macrophage colony-stimulating factor (GM-CSF)-dependent manner. Here, we investigated whether gal-3 regulates the formation of myeloid bone marrow compartments by studying galectin-3−/− mice (gal-3−/−) in the C57BL/6 background. The bone marrow histology of gal-3−/− mice was significantly modified and the myeloid compartments drastically disturbed, in comparison with wild-type (WT) animals. In the absence of gal-3, we found reduced cell density and diaphyseal disorders containing increased trabecular projections into the marrow cavity. Moreover, myeloid cells presented limited capacity to differentiate into mature myeloid cell populations in gal-3−/− mice and the number of hematopoietic multipotent progenitors was increased relative to WT animals. In addition, bone marrow stromal cells of these mice had reduced levels of GM-CSF gene expression. Taken together, our data suggest that gal-3 interferes with hematopoiesis, controlling both precursors and stromal cells and favors terminal differentiation of myeloid progenitors rather than proliferation

    Towards personalised allele-specific CRISPR gene editing to treat autosomal dominant disorders

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    Abstract CRISPR/Cas9 holds immense potential to treat a range of genetic disorders. Allele-specific gene disruption induced by non-homologous end-joining (NHEJ) DNA repair offers a potential treatment option for autosomal dominant disease. Here, we successfully delivered a plasmid encoding S. pyogenes Cas9 and sgRNA to the corneal epithelium by intrastromal injection and acheived long-term knockdown of a corneal epithelial reporter gene, demonstrating gene disruption via NHEJ in vivo. In addition, we used TGFBI corneal dystrophies as a model of autosomal dominant disease to assess the use of CRISPR/Cas9 in two allele-specific systems, comparing cleavage using a SNP-derived PAM to a guide specific approach. In vitro, cleavage via a SNP-derived PAM was found to confer stringent allele-specific cleavage, while a guide-specific approach lacked the ability to distinguish between the wild-type and mutant alleles. The failings of the guide-specific approach highlights the necessity for meticulous guide design and assessment, as various degrees of allele-specificity are achieved depending on the guide sequence employed. A major concern for the use of CRISPR/Cas9 is its tendency to cleave DNA non-specifically at “off-target” sites. Confirmation that S. pyogenes Cas9 lacks the specificity to discriminate between alleles differing by a single base-pair regardless of the position in the guide is demonstrated

    Composition of human islet cell preparations for transplantation

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    To study the cellular composition of human islet cell isolates for transplantation, formalin-fixed and paraffin-embedded cell pellets were stained by the immunoperoxidase method with a panel of antibodies characterising endocrine, epithelial, soft tissue and haematolymphoid components. Immediately after separation, the isolates contained 30-80% islet cells, differing mainly in the content of islet and acinar cells, whereas the soft tissue, ductal/ductular and haematolymphoid elements comprised a relatively constant 10-20%. After 1 week in culture the islet cell content of less highly purified isolates (30-40% islets) dropped dramatically to 5%. The highly purified isolates (70-80% islets) showed only a minimal change in cellular composition; however, approximately two-thirds of islet cells were degranulated and did not stain for insulin. Haematolymphoid components were still present in all cultured isolates. We conclude that primarily mechanical purification methods and short-term culture are not sufficient to eliminate highly immunogenic cells. In addition, short-term culture is deleterious to the isolate if a significant number of acinar cells is still present after enrichment. © 1992 Springer-Verlag

    Quality of life: international and domestic students studying medicine in New Zealand

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    International students form a significant proportion of students studying within universities in Western countries. The quality of life perceptions of international medical students in comparison with domestic medical students has not been well documented. There is some evidence to suggest that international medical students may have different educational and social experiences in relation to their domestic peers. This study investigates the levels of quality of life experienced by international and domestic students studying medicine. A total of 548 medical students completed the abbreviated version of the World Health Organization Quality of Life questionnaire. The focus of the analysis was to evaluate differences between international and domestic students in their early clinical years. The responses were analysed using multivariate analysis of variance methods. International medical students are experiencing lower social and environmental quality of life compared with domestic peers. International medical students in New Zealand have expressed quality of life concerns, which likely have an impact on their academic achievement, feelings of wellness, acculturation, and social adaptation. The findings reinforce the need for creating stronger social networks and accessible accommodation, as well as developing systems to ensure safety, peer mentorship and student support.published_or_final_versio

    Repair of the TGFBI gene in human corneal keratocytes derived from a granular corneal dystrophy patient via CRISPR/Cas9-induced homology-directed repair

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    Abstract Granular corneal dystrophy (GCD) is an autosomal dominant hereditary disease in which multiple discrete and irregularly shaped granular opacities are deposited in the corneal stroma. GCD is caused by a point mutation in the transforming growth factor-β-induced (TGFBI) gene, located on chromosome 5q31. Here, we report the first successful application of CRISPR-Cas9-mediated genome editing for the correction of a TGFBI mutation in GCD patient-derived primary corneal keratocytes via homology-directed repair (HDR). To correct genetic defects in GCD patient cells, we designed a disease-specific guide RNA (gRNA) targeting the R124H mutation of TGFBI, which causes GCD type 2 (GCD2). An R124H mutation in primary human corneal keratocytes derived from a GCD2 patient was corrected by delivering a CRISPR plasmid expressing Cas9/gRNA and a single-stranded oligodeoxynucleotide HDR donor template in vitro. The gene correction efficiency was 20.6% in heterozygous cells and 41.3% in homozygous cells. No off-target effects were detected. These results reveal a new therapeutic strategy for GCD2; this method may also be applicable to other heredity corneal diseases
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