3,430 research outputs found

    Towards a definition of quantum integrability

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    We briefly review the most relevant aspects of complete integrability for classical systems and identify those aspects which should be present in a definition of quantum integrability. We show that a naive extension of classical concepts to the quantum framework would not work because all infinite dimensional Hilbert spaces are unitarily isomorphic and, as a consequence, it would not be easy to define degrees of freedom. We argue that a geometrical formulation of quantum mechanics might provide a way out.Comment: 37 pages, AmsLatex, 1 figur

    A mutation in caspase-9 decreases the expression of BAFFR and ICOS in patients with immunodeficiency and lymphoproliferation

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    Lymphocyte apoptosis is mainly induced by either death receptor-dependent activation of caspase-8 or mitochondria-dependent activation of caspase-9. Mutations in caspase-8 lead to autoimmunity/lymphoproliferation and immunodeficiency. This work describes a heterozygous H237P mutation in caspase-9 that can lead to similar disorders. H237P mutation was detected in two patients: Pt1 with autoimmunity/lymphoproliferation, severe hypogammaglobulinemia and Pt2 with mild hypogammaglobulinemia and Burkitt lymphoma. Their lymphocytes displayed defective caspase-9 activity and decreased apoptotic and activation responses. Transfection experiments showed that mutant caspase-9 display defective enzyme and proapoptotic activities and a dominant-negative effect on wild-type caspase-9. Ex vivo analysis of the patients' lymphocytes and in vitro transfection experiments showed that the expression of mutant caspase-9 correlated with a downregulation of BAFFR (B-cell-activating factor belonging to the TNF family (BAFF) receptor) in B cells and ICOS (inducible T-cell costimulator) in T cells. Both patients carried a second inherited heterozygous mutation missing in the relatives carrying H237P: Pt1 in the transmembrane activator and CAML interactor (TACI) gene (S144X) and Pt2 in the perforin (PRF1) gene (N252S). Both mutations have been previously associated with immunodeficiencies in homozygosis or compound heterozygosis. Taken together, these data suggest that caspase-9 mutations may predispose to immunodeficiency by cooperating with other genetic factors, possibly by downregulating the expression of BAFFR and ICO

    GOOGLE EARTH ENGINE: APPLICATION OF ALGORITHMS FOR REMOTE SENSING OF CROPS IN TUSCANY (ITALY)

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    Abstract. Remote sensing has become an important mean to assess crop areas, specially for the identification of crop types. Google Earth Engine (GEE) is a free platform that provides a large number of satellite images from different constellations. Moreover, GEE provides pixel-based classifiers, which are used for mapping agricultural areas. The objective of this work is to evaluate the performance of different classification algorithms such as Minimum Distance (MD), Random Forest (RF), Support Vector Machine (SVM), Classification and Regression Trees (CART) and Na¨ıve Bayes (NB) on an agricultural area in Tuscany (Italy). Four different scenarios were implemented in GEE combining different information such as optical and Synthetic Aperture Radar (SAR) data, indices and time series. Among the five classifiers used the best performers were RF and SVM. Integrating Sentinel-1 (S1) and Sentinel-2 (S2) slightly improves the classification in comparison to the only S2 image classifications. The use of time series substantially improves supervised classifications. The analysis carried out so far lays the foundation for the integration of time series of SAR and optical data

    Pasta consumption and connected dietary habits: Associations with glucose control, adiposity measures, and cardiovascular risk factors in people with type 2 diabetes—TOSCA.IT study

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    Background: Pasta is a refined carbohydrate with a low glycemic index. Whether pasta shares the metabolic advantages of other low glycemic index foods has not really been investigated. The aim of this study is to document, in people with type-2 diabetes, the consumption of pasta, the connected dietary habits, and the association with glucose control, measures of adiposity, and major cardiovascular risk factors. Methods: We studied 2562 participants. The dietary habits were assessed with the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire. Sex-specific quartiles of pasta consumption were created in order to explore the study aims. Results: A higher pasta consumption was associated with a lower intake of proteins, total and saturated fat, cholesterol, added sugar, and fiber. Glucose control, body mass index, prevalence of obesity, and visceral obesity were not significantly different across the quartiles of pasta intake. No relation was found with LDL cholesterol and triglycerides, but there was an inverse relation with HDL-cholesterol. Systolic blood pressure increased with pasta consumption; but this relation was not confirmed after correction for confounders. Conclusions: In people with type-2 diabetes, the consumption of pasta, within the limits recommended for total carbohydrates intake, is not associated with worsening of glucose control, measures of adiposity, and major cardiovascular risk factors

    Absence of <i>Pseudomonas syringae</i> pv. <i>actinidiae</i> in kiwifruit leaves and flowers from Buenos Aires Province, Argentina

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    Argentina has around 1000 ha of kiwifruit orchards in Buenos Aires Province. This country is recognized as free of Pseudomonas syringae pv. actinidiae (Psa). In 2013, the National Sanitary Service (SENASA) imposed measures to avoid the entrance of this pathogen to the kiwifruit production areas. In this way, a vigilance plan was established and the introduction of plant material was regulated. In March 2015, three infected samples with Psa were detected in orchards at the South-East of Buenos Aires Province and they were immediately eradicated by SENASA. The objective of this work was to identify the bacteria associated with kiwifruit leaf spots and flower blights in commercial orchards of Actinidia deliciosa ‘Hayward’ at Buenos Aires Province, during the 2015-2016 growing season. On spring and autumn seasons, plant tissues were collected from a 100 ha area located in the North and South-East of this Province. Bacterial isolates were obtained from flowers and leaves by tissues mashing and inoculation on nutrient agar supplemented with 5% sucrose (NSA). The primary identification of isolates was performed by biochemical and physiological tests. To confirm their identity, duplex-PCR tests were performed, including negative and positive controls (no template and Psa DNA, respectively). From symptomatic and asymptomatic samples, 120 bacterial isolates were obtained. Thirty of these isolates were morphologically similar to Psa, forming white-creamy, convex, domed and mucoid colonies on NSA. Also, all of them were Gram-negative, produced a green fluorescent pigment on King’s B medium and their metabolism was aerobic. However, none of these strains examined produced any bands following the amplification by PCR with Psa specific primers. Our results show the absence of Psa in the analyzed samples. Further studies are needed to identify these non-Psa bacteria associated with kiwifruit leaf spots and flower blights.Facultad de Ciencias Agrarias y Forestale

    Absence of <i>Pseudomonas syringae</i> pv. <i>actinidiae</i> in kiwifruit leaves and flowers from Buenos Aires Province, Argentina

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    Argentina has around 1000 ha of kiwifruit orchards in Buenos Aires Province. This country is recognized as free of Pseudomonas syringae pv. actinidiae (Psa). In 2013, the National Sanitary Service (SENASA) imposed measures to avoid the entrance of this pathogen to the kiwifruit production areas. In this way, a vigilance plan was established and the introduction of plant material was regulated. In March 2015, three infected samples with Psa were detected in orchards at the South-East of Buenos Aires Province and they were immediately eradicated by SENASA. The objective of this work was to identify the bacteria associated with kiwifruit leaf spots and flower blights in commercial orchards of Actinidia deliciosa ‘Hayward’ at Buenos Aires Province, during the 2015-2016 growing season. On spring and autumn seasons, plant tissues were collected from a 100 ha area located in the North and South-East of this Province. Bacterial isolates were obtained from flowers and leaves by tissues mashing and inoculation on nutrient agar supplemented with 5% sucrose (NSA). The primary identification of isolates was performed by biochemical and physiological tests. To confirm their identity, duplex-PCR tests were performed, including negative and positive controls (no template and Psa DNA, respectively). From symptomatic and asymptomatic samples, 120 bacterial isolates were obtained. Thirty of these isolates were morphologically similar to Psa, forming white-creamy, convex, domed and mucoid colonies on NSA. Also, all of them were Gram-negative, produced a green fluorescent pigment on King’s B medium and their metabolism was aerobic. However, none of these strains examined produced any bands following the amplification by PCR with Psa specific primers. Our results show the absence of Psa in the analyzed samples. Further studies are needed to identify these non-Psa bacteria associated with kiwifruit leaf spots and flower blights.Facultad de Ciencias Agrarias y Forestale

    Plasma endothelin-1 concentrations in patients with retinal vein occlusions

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    Aims-To investigate whether plasma levels of endothelin-1 (ET-1), a potent vasoconstricting peptide that is crucial in regulating retinal blood flow, were elevated in patients with retinal vein occlusion (RVO). Methods-ET-1 plasma concentrations were determined by radioimmunoassays in a double blind fashion in a group of 18 selected patients with RVO, in 20 healthy age matched non-smoking, normoglycaemic, normotensive control subjects, and in 15 patients with uncomplicated essential hypertension in the same age range. Results-Patients with RVO had significantly increased ET-1 plasma levels (14.22 (SD 4.6) pg/ml) compared with both normal subjects (7.90 (1.6) pg/ml; p < 0.05) and hypertensive patients (8.50 (2.9) pg/ml; p < 0.05), The highest concentrations of circulating ET-1 were found in patients with RVO of the ischaemic type (16.97 (3.5) pg/ml; p < 0.01; n = 7). Systemic hypertension alone did not account for the observed increase in plasma ET-I concentrations. Conclusions-These findings raise the possibility that the increased circulating ET-1 levels in patients with RVO may be a marker of the occlusive event, thereby suggesting that ET-1 homeostasis may be relevant to RVO pathogenesis and retinal ischaemic manifestations
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