542 research outputs found

    Degenerate Elastic Networks

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    We minimize a linear combination of the length and the L2-norm of the curvature among networks in Rd belonging to a given class determined by the number of curves, the order of the junctions, and the angles between curves at the junctions. Since this class lacks compactness, we characterize the set of limits of sequences of networks bounded in energy, providing an explicit representation of the relaxed problem. This is expressed in terms of the new notion of degenerate elastic networks that, rather surprisingly, involves only the properties of the given class, without reference to the curvature. In the case of d= 2 we also give an equivalent description of degenerate elastic networks by means of a combinatorial definition easy to validate by a finite algorithm. Moreover we provide examples, counterexamples, and additional results that motivate our study and show the sharpness of our characterization

    Specific Merluccius otolith growth patterns related to phylogenetics and environmental factors

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    5 pages, 2 figures, 2tablesA comparative morphological study was performed on the otolith growth patterns of 11 species of the genus Merluccius. The otolith growth pattern, based on the radius of the first eight growth increments (GI) from the otolith core, was determined from transverse sections of sagitta otoliths. The structure and periodicity of the GI were identified based on previous knowledge. Two cluster analyses were performed using GI width as a proxy for otolith growth. The first cluster analysis corresponded to the juvenile (immature) period of the ¢sh including the mean width of the first four GI. The second analysis compared the mean width of the next four GI, i.e. those corresponding to mature fish. The results showed an important environmental influence in immature fish; while after maturation, the GI pattern was also related to an endogenous influence depending on the phylogenetic line.This work was supported by the EU FAIR project CT 95-0655. Gabriel Torres’s contribution was funded under the doctoral fellowship grant provided by the Spanish International Co-operation Agency (AECI) and the Latin-American-Catalonian Co-operation Institute (ICCI).Peer reviewe

    First insight into Araucaria araucana (Molina) K. Koch under its southernmost European growing condition: a proposed descriptor list for morphological characterization

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    Araucaria araucana is a south American endemic Conifer of conservation concern. After its introduction to Europe, this species has been often planted for ornamental purposes in parks and gardens, where its unusual appearance was admired. After the mid-1970s this tree received increasing attention from the nursery growers of Pistoia (Tuscany) and became of considerable economic importance. However, being one of the iconic threatened trees listed in CITES Appendix I, the international trade of these species is rigorously regulated. This study was aimed at developing a first morphological descriptor list for further phenotyping of in loco produced plant material. A first step of the research focused on the description and a better understanding of A. araucana phenological phases inferred from Mediterranean climate conditions. The second phase regarded the analysis of observed or measured morphological characteristics of the tree, branches, scales, inflorescences, fruits and seeds observed on a subset of 4 selected putative populations over a 3-year period of vegetative growth. The results allowed to select 39 most discriminant descriptors, which are presented together with their range of variability and classes. The achieved descriptor list represents a suitable tool for the selection of genotypes and for the breeding of A. araucana

    Closed-loop compensation of charge trapping induced by ionizing radiation in MOS capacitors

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    The objective of this work is to explore the capability of a charge trapping control loop to continuously compensate charge induced by ionizing radiation in the dielectric of MOS capacitors. To this effect, two devices made with silicon oxide have been simultaneously irradiated with gamma radiation: one with constant voltage bias, and the other working under a dielectric charge control. The experiment shows substantial charge trapping in the uncontrolled device whereas, at the same time, the control loop is able to compensate the charge induced by gamma radiation in the second device.Peer ReviewedPostprint (author's final draft

    Utility of the new Movement Disorder Society clinical diagnostic criteria for Parkinson's disease applied retrospectively in a large cohort study of recent onset cases

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    Objective: To examine the utility of the new Movement Disorder Society (MDS) diagnostic criteria in a large cohort of Parkinson's disease (PD) patients. Methods: Recently diagnosed (<3.5 years) PD cases fulfilling United Kingdom (UK) brain bank criteria in Tracking Parkinson's, a UK multicenter prospective natural history study were assessed by retrospective application of the MDS criteria. Results: In 2000 cases, 1835 (91.7%) met MDS criteria for PD, either clinically established (n = 1261, 63.1%) or clinically probable (n = 574, 28.7%), leaving 165 (8.3%) not fulfilling criteria. Clinically established cases were significantly more likely to have limb rest tremor (89.3%), a good l-dopa response (79.5%), and olfactory loss (71.1%), than clinically probable cases (60.6%, 44.4%, and 34.5% respectively), but differences between probable PD and ‘not PD’ cases were less evident. In cases not fulfilling criteria, the mean MDS UPDRS3 score (25.1, SD 13.2) was significantly higher than in probable PD (22.3, SD 12.7, p = 0.016) but not established PD (22.9, SD 12.0, p = 0.066). The l-dopa equivalent daily dose of 341 mg (SD 261) in non-PD cases was significantly higher than in probable PD (250 mg, SD 214, p < 0.001) and established PD (308 mg, SD 199, p = 0.025). After 30 months' follow-up, 89.5% of clinically established cases at baseline remained as PD (established/probable), and 86.9% of those categorized as clinically probable at baseline remained as PD (established/probable). Cases not fulfilling PD criteria had more severe parkinsonism, in particular relating to postural instability, gait problems, and cognitive impairment. Conclusion: Over 90% of cases clinically diagnosed as early PD fulfilled the MDS criteria for PD. Those not fulfilling criteria may have an atypical parkinsonian disorder or secondary parkinsonism that is not correctly identified by the UK Brain Bank criteria, but possibly by the new criteria

    Cohomology of bundles on homological Hopf manifold

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    We discuss the properties of complex manifolds having rational homology of S1×S2n1S^1 \times S^{2n-1} including those constructed by Hopf, Kodaira and Brieskorn-van de Ven. We extend certain previously known vanishing properties of cohomology of bundles on such manifolds.As an application we consider degeneration of Hodge-deRham spectral sequence in this non Kahler setting.Comment: To appear in Proceedings of 2007 conference on Several complex variables and Complex Geometry. Xiamen. Chin

    Higher Plasma Soluble Receptor for Advanced Glycation End Products (sRAGE) Levels Are Associated With Incident Cardiovascular Disease and All-Cause Mortality in Type 1 Diabetes: A 12-Year Follow-Up Study

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    To investigate the associations of plasma levels of soluble receptor for advanced glycation end products (sRAGE) with incident cardiovascular disease (CVD) and allcause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal dysfunction, low-grade inflammation, arterial stiffness, and advanced glycation end products (AGEs). RESEARCH DESIGN AND METHODS - We prospectively followed 169 individuals with diabetic nephropathy and 170 individuals with persistent normoalbuminuria who were free of CVD at study entry and in whom levels of sRAGE and other biomarkers were measured at baseline. The median follow-up duration was 12.3 years (7.6 -12.5). RESULTS - The incidence of fatal and nonfatal CVD and allcause mortality increased with higher baseline levels of log-transformed sRAGE (Ln-sRAGE) independently of other CVD risk factors: hazard ratio (HR) 1.90 (95% CI 1.13-3.21) and 2.12 (1.26 -3.57) per 1-unit increase in Ln-sRAGE, respectively. Adjustments for estimated glomerular filtration rate (eGFRMDRD), but not or to a smaller extent for markers of endothelial dysfunction, low-grade inflammation, arterial stiffness, and AGEs, attenuated these associations to HR 1.59 (95% CI 0.91-2.77) for fatal and nonfatal CVD events and to 1.90 (1.09 -3.31) for all-cause mortality. In addition, in patients with nephropathy, the rate of decline of GFR was 1.38 ml/min/1.73 m2 per year greater per 1-unit increase of Ln-sRAGE at baseline (P = 0.036). CONCLUSIONS - Higher levels of sRAGE are associated with incident fatal and nonfatal CVD and all-cause mortality in individuals with type 1 diabetes. sRAGE-associated renal dysfunction may partially explain this association

    The use of caspase inhibitors in pulsed-field gel electrophoresis may improve the estimation of radiation-induced DNA repair and apoptosis

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    Background: Radiation-induced DNA double-strand break (DSB) repair can be tested by using pulsed-field gel electrophoresis (PFGE) in agarose-encapsulated cells. However, previous studies have reported that this assay is impaired by the spontaneous DNA breakage in this medium. We investigated the mechanisms of this fragmentation with the principal aim of eliminating it in order to improve the estimation of radiation-induced DNA repair. Methods: Samples from cancer cell cultures or xenografted tumours were encapsulated in agarose plugs. The cell plugs were then irradiated, incubated to allow them to repair, and evaluated by PFGE, caspase-3, and histone H2AX activation (gamma H2AX). In addition, apoptosis inhibition was evaluated through chemical caspase inhibitors. Results: We confirmed that spontaneous DNA fragmentation was associated with the process of encapsulation, regardless of whether cells were irradiated or not. This DNA fragmentation was also correlated to apoptosis activation in a fraction of the cells encapsulated in agarose, while non-apoptotic cell fraction could rejoin DNA fragments as was measured by gamma H2AX decrease and PFGE data. We were able to eliminate interference of apoptosis by applying specific caspase inhibitors, and improve the estimation of DNA repair, and apoptosis itself. Conclusions: The estimation of radiation-induced DNA repair by PFGE may be improved by the use of apoptosis inhibitors. The ability to simultaneously determine DNA repair and apoptosis, which are involved in cell fate, provides new insights for using the PFGE methodology as functional assay

    SILAC-based phosphoproteomics reveals an inhibitory role of KSR1 in p53 transcriptional activity via modulation of DBC1

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    BACKGROUND We have previously identified kinase suppressor of ras-1 (KSR1) as a potential regulatory gene in breast cancer. KSR1, originally described as a novel protein kinase, has a role in activation of mitogen-activated protein kinases. Emerging evidence has shown that KSR1 may have dual functions as an active kinase as well as a scaffold facilitating multiprotein complex assembly. Although efforts have been made to study the role of KSR1 in certain tumour types, its involvement in breast cancer remains unknown. METHODS A quantitative mass spectrometry analysis using stable isotope labelling of amino acids in cell culture (SILAC) was implemented to identify KSR1-regulated phosphoproteins in breast cancer. In vitro luciferase assays, co-immunoprecipitation as well as western blotting experiments were performed to further study the function of KSR1 in breast cancer. RESULTS Of significance, proteomic analysis reveals that KSR1 overexpression decreases deleted in breast cancer-1 (DBC1) phosphorylation. Furthermore, we show that KSR1 decreases the transcriptional activity of p53 by reducing the phosphorylation of DBC1, which leads to a reduced interaction of DBC1 with sirtuin-1 (SIRT1); this in turn enables SIRT1 to deacetylate p53. CONCLUSION Our findings integrate KSR1 into a network involving DBC1 and SIRT1, which results in the regulation of p53 acetylation and its transcriptional activity
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