390 research outputs found

    Chorological and nomenclatural notes on peruvian carex (Cyperaceae)

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    Here we present relevant records of nine species of the genus Carex (Cyperaceae) new for Peru: C. amicta, C. brehmeri, C. camptoglochin, C. enneastachya, C. livida, C. maritima, C. ownbeyi, C. ruth-satzae, and C. vallis-pulchrae. We perform the lectotypification of the names Carex camptoglochin, C. amicta and C. confertospicata.En este estudio se reconocen nueve registros nuevos de especies del género Carex (Cyperaceae) para la flora del Perú: C. amicta, C. brehmeri, C. camptoglochin, C. enneastachya, C. livida, C. maritima, C. ownbeyi, C. ruthsatzae y C. vallis-pulchrae. También hemos realizado la lectotipificación de los nombres Carex camptoglochin, C. amicta y C. confertospicata

    Detection of Azoxystrobin Fungicide and Metabolite Azoxystrobin-Acid in Pregnant Women and Children, Estimation of Daily Intake, and Evaluation of Placental and Lactational Transfer in Mice

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    BACKGROUND: Azoxystrobin (AZ) is a broad-spectrum strobilurin fungicide that is used in agriculture and was recently added to mold- and mildew-resistant wallboards. AZ was found to have toxic effects in animals at embryonic stages and was listed as a frontline target for biomonitoring in children. OBJECTIVES: This study investigated exposure to AZ in pregnant women and young children, whether AZ could be transferred from an exposed mother to offspring, and whether AZ or one of its primary metabolites, AZ-acid, was neurotoxic in vitro. METHODS: We quantified AZ-acid, a sensitive indicator of AZ exposure, in urine samples collected from 8 pregnant women (12 urine samples) and 67 children (40-84 months old; 96 urine samples) with high-resolution mass spectrometry. Gestational and lactational transfer was assessed in C57Bl/6 mice. Neurotoxicity of AZ and AZ-acid was investigated in vitro with mouse cortical neuron cultures. RESULTS: AZ-acid was present above the limit of quantification (formula presented ) in 100% of the urine samples from pregnant women and in 70% of the urine samples from children, with median concentration of 0.10 and formula presented , and maximal concentration of 2.70 and formula presented , respectively. Studies in mice revealed that AZ transferred from the mother to offspring during gestation by crossing the placenta and entered the developing brain. AZ was also transferred to offspring via lactation. High levels of cytotoxicity were observed in embryonic mouse cortical neurons at concentrations that modeled environmentally relevant exposures. DISCUSSION: Our study suggested that pregnant women and children were exposed to AZ, and at least 10% of the children (2 out of 20 that were evaluated at two ages) showed evidence of chronic exposure. Future studies are warranted to evaluate whether chronic AZ exposure affects human health and development

    Hubble expansion and structure formation in the "running FLRW model" of the cosmic evolution

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    A new class of FLRW cosmological models with time-evolving fundamental parameters should emerge naturally from a description of the expansion of the universe based on the first principles of quantum field theory and string theory. Within this general paradigm, one expects that both the gravitational Newton's coupling, G, and the cosmological term, Lambda, should not be strictly constant but appear rather as smooth functions of the Hubble rate. This scenario ("running FLRW model") predicts, in a natural way, the existence of dynamical dark energy without invoking the participation of extraneous scalar fields. In this paper, we perform a detailed study of these models in the light of the latest cosmological data, which serves to illustrate the phenomenological viability of the new dark energy paradigm as a serious alternative to the traditional scalar field approaches. By performing a joint likelihood analysis of the recent SNIa data, the CMB shift parameter, and the BAOs traced by the Sloan Digital Sky Survey, we put tight constraints on the main cosmological parameters. Furthermore, we derive the theoretically predicted dark-matter halo mass function and the corresponding redshift distribution of cluster-size halos for the "running" models studied. Despite the fact that these models closely reproduce the standard LCDM Hubble expansion, their normalization of the perturbation's power-spectrum varies, imposing, in many cases, a significantly different cluster-size halo redshift distribution. This fact indicates that it should be relatively easy to distinguish between the "running" models and the LCDM cosmology using realistic future X-ray and Sunyaev-Zeldovich cluster surveys.Comment: Version published in JCAP 08 (2011) 007: 1+41 pages, 6 Figures, 1 Table. Typos corrected. Extended discussion on the computation of the linearly extrapolated density threshold above which structures collapse in time-varying vacuum models. One appendix, a few references and one figure adde

    The recovery umbrella in the world of elite sport: Do not forget the coaching and performance staff

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    In the field of sports science, the recovery umbrella is a trending topic, and even more so in the world of elite sports. This is evidenced by the significant increase in scientific publications during the last 10 years as teams look to find a competitive edge. Recovery is recognized to be an integral component to assist athlete preparation in the restoration of physical and psychological function, and subsequently, performance in elite team sports athletes. However, the importance of recovery in team staff members (sports coaches and performance staff) in elite sports appears to be a forgotten element. Given the unrelenting intense nature of daily tasks and responsibilities of team staff members, the elite sports environment can predispose coaches to increased susceptibility to psycho-socio physiological fatigue burden, and negatively affect health, wellbeing, and performance. Therefore, the aim of this opinion was to (1) develop an educational recovery resource for team staff members, (2) identify organizational task-specific fatigue indicators and barriers to recovery and self-care in team staff members, and (3) present recovery implementation strategies to assist team staff members in meeting their organizational functions. It is essential that we do not forget the coaching and performance staff in the recovery process. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Spatial and temporal variation of fish assemblage associated with aquatic macrophyte patches in the littoral zone of the Ayapel Swamp Complex, Colombia

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    ABSTRACT: Aim: The purpose of the present study was to examine spatial and temporal variation in fish assemblage structure associated with aquatic macrophytes in the littoral zone of the ASC. Methods: Specimens were caught between January 2008 and February 2009, over four limnimetric moments, using both cast net and seine net. Data on the temperature, electrical conductivity, pH and dissolved oxygen was recorded for the characterization of the water mass in the sites. Results: A total of 34,151 specimens from 44 species were collected. The most abundant species were Eigenmannia virescens, Astyanax caucanus, Astyanax fasciatus, Roeboides dayi and Cyphocharax magdalenae, which together accounted for more than 75% of the sample. Temporal and spatial comparisons showed variation in the environmental conditions and highlighted the existence of heterogeneous abiotic conditions (p0.05) regarding the fish assemblage structure. The multivariate analysis showed no significant relationship between existing environmental conditions and the fish assemblage (p=0.04). The analysis also showed the absence of a relationship between the fish assemblage and environmental variables with respect to the flood pulse and sampling sites (p>0.05). Conclusion: The uniformity of the fish communities that inhabit aquatic macrophyte patches in the littoral region of the ASC may be related to the availability of suitable habitat in structural terms, that probably supports a more abundant and varied wildlife
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