340 research outputs found

    Marine epibiosis. II. Reduced fouling on Polysyncraton lacazei (Didemnidae, Tunicata) and proposal of an antifouling potential index

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    Polysyncraton lacazei is a colonial tunicate (family didemnidae) living in the NW-mediterranean rocky sublitoral. A thorough scanning of numerous colonies revealed that in spite of an apparently heavy local fouling pressure only one fouling species — a kamptozoan — is encountered with some regularity on Polysyncraton. We try to define the epibiotic situation of sessile marine organisms as composed of four epibiotic parameters: longevity or exposure time (A), epibiont load (E), colonizer pool (CP) and fouling-period (FP). Subsequently, these factors are combined to propose an “Antifouling Potential” index: AFP=(1−E/CP)×A/(FP+A). This index is intended to permit evaluating the relative antifouling defense potency to be expected in a given organism in a given epibiotic situation and to compare different cases of epibiosis and fouling

    Dietary behavior and knowledge of dental erosion among Chinese adults

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    <p>Abstract</p> <p>Objectives</p> <p>To study the dietary behavior and knowledge about dental erosion and self-reported symptoms that can be related to dental erosion among Chinese adults in Hong Kong.</p> <p>Methods</p> <p>Chinese adults aged 25-45 years were randomly selected from a list of registered telephone numbers generated by computer. A telephone survey was administered to obtain information on demographic characteristics, dietary habits, dental visits, and knowledge of and presence of self-reported symptoms that can be related to dental erosion.</p> <p>Results</p> <p>A total of 520 participants were interviewed (response rate, 75%; sampling error, ± 4.4%) and their mean age was 37. Most respondents (79%) had ever had caries, and about two thirds (64%) attended dental check-ups at least once a year. Respondents had a mean of 5.4 meals per day and 36% had at least 6 meals per day. Fruit (89%) and lemon tea/water (41%) were the most commonly consumed acidic food and beverage. When asked if they ever noticed changes in their teeth, most respondents (92%) said they had experienced change that can be related to erosion. However, many (71%) had never heard about dental erosion and 53% mixed up dental erosion with dental caries.</p> <p>Conclusion</p> <p>Hong Kong Chinese adults have frequent intake of food and many have experienced symptoms that can be related to dental erosion. Their level of awareness of and knowledge about dental erosion is generally low, despite most of them have regular dental check-ups. Dental health education is essential to help the public understand dental erosion and its damaging effects.</p

    Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance

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    This paper presents DELPHI measurements and interpretations of cross-sections, forward-backward asymmetries, and angular distributions, for the e+e- -> ffbar process for centre-of-mass energies above the Z resonance, from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are consistent with the predictions of the Standard Model and are used to study a variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering and several models which include physics beyond the Standard Model: the exchange of Z' bosons, contact interactions between fermions, the exchange of gravitons in large extra dimensions and the exchange of sneutrino in R-parity violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.

    A Determination of the Centre-of-Mass Energy at LEP2 using Radiative 2-fermion Events

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    Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy and momentum constraint methods. The results are expressed as deviations from the nominal LEP centre-of-mass energy, measured using other techniques. The results are found to be compatible with the LEP Energy Working Group estimates for a combination of the 1997 to 2000 data sets.Comment: 20 pages, 6 figures, Accepted by Eur. Phys. J.

    A Measurement of the Tau Hadronic Branching Ratios

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    The exclusive and semi-exclusive branching ratios of the tau lepton hadronic decay modes (h- v_t, h- pi0 v_t, h- pi0 pi0 v_t, h- \geq 2pi0 v_t, h- \geq 3pi0 v_t, 2h- h+ v_t, 2h- h+ pi0 v_t, 2h- h+ \geq 2pi0 v_t, 3h- 2h+ v_t and 3h- 2h+ \geq 1pi0 v_t) were measured with data from the DELPHI detector at LEP.Comment: 53 pages, 18 figures, Accepted by Eur. Phys. J.

    JAK-STAT and AKT pathway-coupled genes in erythroid progenitor cells through ontogeny

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    Background: It has been reported that the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway regulates erythropoietin (EPO)-induced survival, proliferation, and maturation of early erythroid progenitors. Erythroid cell proliferation and survival have also been related to activation of the JAK-STAT pathway. The goal of this study was to observe the function of EPO activation of JAK-STAT and PI3K/AKT pathways in the development of erythroid progenitors from hematopoietic CD34(+) progenitor cells, as well as to distinguish early EPO target genes in human erythroid progenitors during ontogeny. Methods: Hematopoietic CD34(+) progenitor cells, isolated from fetal and adult hematopoietic tissues, were differentiated into erythroid progenitor cells. We have used microarray analysis to examine JAK-STAT and PI3K/AKT related genes, as well as broad gene expression modulation in these human erythroid progenitor cells. Results: In microarray studies, a total of 1755 genes were expressed in fetal liver, 3844 in cord blood, 1770 in adult bone marrow, and 1325 genes in peripheral blood-derived erythroid progenitor cells. The erythroid progenitor cells shared 1011 common genes. Using the Ingenuity Pathways Analysis software, we evaluated the network pathways of genes linked to hematological system development, cellular growth and proliferation. The KITLG, EPO, GATA1, PIM1 and STAT3 genes represent the major connection points in the hematological system development linked genes. Some JAK-STAT signaling pathway-linked genes were steadily upregulated throughout ontogeny (PIM1, SOCS2, MYC, PTPN11), while others were downregulated (PTPN6, PIAS, SPRED2). In addition, some JAK-STAT pathway related genes are differentially expressed only in some stages of ontogeny (STATs, GRB2, CREBB). Beside the continuously upregulated (AKT1, PPP2CA, CHUK, NFKB1) and downregulated (FOXO1, PDPK1, PIK3CG) genes in the PI3K-AKT signaling pathway, we also observed intermittently regulated gene expression (NFKBIA, YWHAH). Conclusions: This broad overview of gene expression in erythropoiesis revealed transcription factors differentially expressed in some stages of ontogenesis. Finally, our results show that EPO-mediated proliferation and survival of erythroid progenitors occurs mainly through modulation of JAK-STAT pathway associated STATs, GRB2 and PIK3 genes, as well as AKT pathway-coupled NFKBIA and YWHAH genes

    Search for supersymmetric particles in scenarios with a gravitino LSP and stau NLSP

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    Sleptons, neutralinos and charginos were searched for in the context of scenarios where the lightest supersymmetric particle is the gravitino. It was assumed that the stau is the next-to-lightest supersymmetric particle. Data collected with the DELPHI detector at a centre-of-mass energy near 189 GeV were analysed combining the methods developed in previous searches at lower energies. No evidence for the production of these supersymmetric particles was found. Hence, limits were derived at 95% confidence level.Comment: 31 pages, 14 figure

    Search for the standard model Higgs boson at LEP

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    Diagnostic delay for giant cell arteritis – a systematic review and meta-analysis

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    Background Giant cell arteritis (GCA), if untreated, can lead to blindness and stroke. The study’s objectives were to (1) determine a new evidence-based benchmark of the extent of diagnostic delay for GCA and (2) examine the role of GCA-specific characteristics on diagnostic delay. Methods Medical literature databases were searched from inception to November 2015. Articles were included if reporting a time-period of diagnostic delay between onset of GCA symptoms and diagnosis. Two reviewers assessed the quality of the final articles and extracted data from these. Random-effects meta-analysis was used to pool the mean time-period (95% confidence interval (CI)) between GCA symptom onset and diagnosis, and the delay observed for GCA-specific characteristics. Heterogeneity was assessed by I 2 and by 95% prediction interval (PI). Results Of 4128 articles initially identified, 16 provided data for meta-analysis. Mean diagnostic delay was 9.0 weeks (95% CI, 6.5 to 11.4) between symptom onset and GCA diagnosis (I 2 = 96.0%; P < 0.001; 95% PI, 0 to 19.2 weeks). Patients with a cranial presentation of GCA received a diagnosis after 7.7 (95% CI, 2.7 to 12.8) weeks (I 2 = 98.4%; P < 0.001; 95% PI, 0 to 27.6 weeks) and those with non-cranial GCA after 17.6 (95% CI, 9.7 to 25.5) weeks (I 2 = 96.6%; P < 0.001; 95% PI, 0 to 46.1 weeks). Conclusions The mean delay from symptom onset to GCA diagnosis was 9 weeks, or longer when cranial symptoms were absent. Our research provides an evidence-based benchmark for diagnostic delay of GCA and supports the need for improved public awareness and fast-track diagnostic pathways

    Knee stability assessment on anterior cruciate ligament injury: Clinical and biomechanical approaches

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    Anterior cruciate ligament (ACL) injury is common in knee joint accounting for 40% of sports injury. ACL injury leads to knee instability, therefore, understanding knee stability assessments would be useful for diagnosis of ACL injury, comparison between operation treatments and establishing return-to-sport standard. This article firstly introduces a management model for ACL injury and the contribution of knee stability assessment to the corresponding stages of the model. Secondly, standard clinical examination, intra-operative stability measurement and motion analysis for functional assessment are reviewed. Orthopaedic surgeons and scientists with related background are encouraged to understand knee biomechanics and stability assessment for ACL injury patients
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