183 research outputs found

    Overlapping patterns of morphometric and genetic differentiation in the Mediterranean goby Pomatoschistus tortonesei Miller, 1968 (Perciformes, Gobiidae) in Tunisian lagoons

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    Abstract. The genetic and morphological variations of Pomatoschistus tortonesei Miller, 1968 were studied in samples collected from three Tunisian lagoons. The morphological analysis included 18 morphometric measurements and was based on linear discriminant analysis (LDA), whereas the genetic analysis was based on the 16S-rRNA and COI mitochondrial genes. Both analyses differentiated the populations and demonstrated consistently a well-supported differentiation between the western Mediterranean samples (Bizerta and Tunis South lagoons) and the eastern Mediterranean sample (El Bibane lagoon). The observed differentiation could be explained in terms of the geographic isolation of the various populations and the influence of environmental factors, which differ greatly between the different sites. The molecular results revealed that the populations are characterised by unique haplotypes which are well defined in relation to limited gene flow and restricted dispersal abilities. Additionally, it seems that local selective pressures have modelled biometrical variation. Morphological results can reflect a differential habitat use revealed in the cephalic features and a different response to hydrodynamic constraints developed in dissimilar dorsal and pelvic fin lengths

    Sensitivity of Melt Pool Size and Porosity Appearing to Base Plate Preheating in Laser Powder Bed Fusion Process

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    The base plate temperature ranks among the crucial building parameters whose effect on melt pool dimensions and porosity defects generation has not been sufficiently discussed in literature. In the current study, with the aim to explore the dependence between melt pool dimensions, porosity defects and base plate preheating, a 3-dimensional thermal finite element model is carried out to create IN718 single beads, at various base plate temperatures. The dimensions of the melt pool behave favourably with the base plate preheating. Indeed, the melt pool depth, width and length increase continuously with the heat of the base plate, from 20 °C to 500 °C. The melt pool width is more responsive to the base plate temperature than the melt pool depth. Numerical results also indicate that the melt dimensions become more responsive to the temperature of the base plate at a slower scan speed. The degree of porosity is predicted under multiple values of base plate temperature and the results show that porosity tends to disappear with further preheating of the base plate. A satisfying accordance between the numerical finding and the experimental results from literature is identified

    Reperfusion therapy in renal dysfunction patients presenting with STEMI: Which is better in the Tunisian context?

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    BackgroundPatients with renal insufficiency experience worse prognosis after STEMI. Current guidelines do not clearly draw specific strategies for renal dysfunction (RD) patients, and most clinical trials exclude them from the study population.Aim of the studyTo compare primary PCI (PPCI) and thrombolysis (using Strepokinase) results as well as in-hospital mortality after successful reperfusion between patients with or without RD.MethodsFrom January 1995 to October 2011, 1388 patients admitted for STEMI were enrolled in the MIRAMI (MonastIR’s Acute Myocardial Infarction) registry. Two reperfusion groups were identified: PPCI (315 patients) and thrombolysis (379 patients). Patients who underwent rescue PCI were excluded. Due to lacking clearance data, we used a serum creatinine level >130μmol/l to define RD patients. We compared in each reperfusion group: (1) The success of revascularization (TIMI III flow restoring with <20% residual stenosis after PPCI, pain relief with ST regression >50% 60min after thrombolysis) and (2) the in-hospital mortality rate after reperfusion success between the RD patients (RD+) and normal renal function patients (RD−).ResultsNinety patients (13%) had RD, 50% of which underwent PPCI, and 50% received thrombolytics. Among RD+ and RD- groups, baseline characteristics were similar between the two reperfusion groups.In the PPCI group, although TIMI flow was similar before angioplasty (p=0.82), TIMI III restoring was significantly lower in the RD+ group (78.6% vs 91.8%, p=0.013). Suboptimal result was also higher in the RD+ group (13.6% vs 2.7%, p<0.001), but ST regression after TIMI III achievement was similar in the 2 groups (p=0.43) reflecting probably no microvascular damage.In the thrombolysis group, successful reperfusion was also significantly lower when RD exists (58% vs 74%, p=0.03).After successful reperfusion, in-hospital mortality is higher among RD+ patients in the PPCI group (33.3% vs 4.3%, p<0.001), whereas it is similar after successful thrombolysis (2.6% vs 0%, p=0.42).ConclusionRD reduces either PPCI or thrombolysis success, with no proven microvascular damage after PPCI. In-hospital prognosis is however worse in RD group only after successful PPCI, but not after successful Streptokinase thrombolysis

    Sensitivity of Melt Pool Dimensions and Keyhole to Laser Beam Diameter

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    The laser powder bed fusion process has witnessed a huge interest in recent years since it has the potential to produce challenging shapes in a broad range of applications. The process parameters have a considerable effect on melt pool size and on the development of defect porosity. This paper predicts numerically the effect of a large range of laser beam diameters on melt pool dimensions and on the occurrence of porosity defects such as keyhole. A series of single beads of Inconel IN625 was made using various combinations of beam diameters, scan speeds, and laser powers. The use of a large diameter was more suitable rather than a small diameter as it ensures a large and shallow heat affected zone, thus decreasing the development of the keyhole defect. Our numerical results correlate satisfactorily with experimental finding from literature

    Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

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    SUMO-Targeted Ubiquitin Ligase, Rad60, and Nse2 SUMO Ligase Suppress Spontaneous Top1–Mediated DNA Damage and Genome Instability

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    Through as yet undefined proteins and pathways, the SUMO-targeted ubiquitin ligase (STUbL) suppresses genomic instability by ubiquitinating SUMO conjugated proteins and driving their proteasomal destruction. Here, we identify a critical function for fission yeast STUbL in suppressing spontaneous and chemically induced topoisomerase I (Top1)–mediated DNA damage. Strikingly, cells with reduced STUbL activity are dependent on tyrosyl–DNA phosphodiesterase 1 (Tdp1). This is notable, as cells lacking Tdp1 are largely aphenotypic in the vegetative cell cycle due to the existence of alternative pathways for the removal of covalent Top1–DNA adducts (Top1cc). We further identify Rad60, a SUMO mimetic and STUbL-interacting protein, and the SUMO E3 ligase Nse2 as critical Top1cc repair factors in cells lacking Tdp1. Detection of Top1ccs using chromatin immunoprecipitation and quantitative PCR shows that they are elevated in cells lacking Tdp1 and STUbL, Rad60, or Nse2 SUMO ligase activity. These unrepaired Top1ccs are shown to cause DNA damage, hyper-recombination, and checkpoint-mediated cell cycle arrest. We further determine that Tdp1 and the nucleotide excision repair endonuclease Rad16-Swi10 initiate the major Top1cc repair pathways of fission yeast. Tdp1-based repair is the predominant activity outside S phase, likely acting on transcription-coupled Top1cc. Epistasis analyses suggest that STUbL, Rad60, and Nse2 facilitate the Rad16-Swi10 pathway, parallel to Tdp1. Collectively, these results reveal a unified role for STUbL, Rad60, and Nse2 in protecting genome stability against spontaneous Top1-mediated DNA damage

    Evaluation of extra-virgin olive oils shelf life using an electronic tongue-chemometric approach

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    Physicochemical quality parameters, olfactory and gustatoryretronasal positive sensations of extra-virgin olive oils vary during storage leading to a decrease in the overall quality. Olive oil quality decline may prevent the compliance of olive oil quality with labeling and significantly reduce shelf life, resulting in important economic losses and negatively condition the consumer confidence. The feasibility of applying an electronic tongue to assess olive oils usual commercial light storage conditions and storage time was evaluated and compared with the discrimination potential of physicochemical or positive olfactory/gustatory sensorial parameters. Linear discriminant models, based on subsets of 58 electronic tongue sensor signals, selected by the meta-heuristic simulated annealing variable selection algorithm, allowed the correct classification of olive oils according to the light exposition conditions and/or storage time (sensitivities and specificities for leave-one-out cross-validation: 8296 %). The predictive performance of the E-tongue approach was further evaluated using an external independent dataset selected using the KennardStone algorithm and, in general, better classification rates (sensitivities and specificities for external dataset: 67100 %) were obtained compared to those achieved using physicochemical or sensorial data. So, the work carried out is a proof-of-principle that the proposed electrochemical device could be a practical and versatile tool for, in a single and fast electrochemical assay, successfully discriminate olive oils with different storage times and/or exposed to different light conditions.The authors acknowledge the financial support from the strategic funding of UID/BIO/04469/2013 unit, from Project POCI-01-0145-FEDER-006984—Associate Laboratory LSRELCM funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI)—and by national funds through FCT—Fundação para a Ciência e a Tecnologia and under the strategic funding of UID/BIO/04469/2013 unit. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).info:eu-repo/semantics/publishedVersio

    Culex pipiens, an Experimental Efficient Vector of West Nile and Rift Valley Fever Viruses in the Maghreb Region

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    West Nile fever (WNF) and Rift Valley fever (RVF) are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV) circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV) re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 107.8 and 108.5 plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14–21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology
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