3,715 research outputs found

    Effects of Dominant Plant Species and Water Depth on Methane Fluxes in a Freshwater Wetland

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    Methane (CH4) is a highly potent greenhouse gas (GHG) found to contribute to the global problem of atmospheric warming. Wetlands have been documented to possess the ability to impact the earth’s CH4 cycle yet are in a state of global depletion. CH4 flux rates in wetlands have been found to vary within wetlands based on variability in environmental factors. There is a lack o f consensus on the effects of water depth as well as dominant plant type on CH4 flux rates. In this study on Lake Wapalanne, Sussex County, NJ, submerged areas were found to produce CH4 while non-inundated, saturated areas harboring emergent vegetation were found to consume CH4. Shallow submerged areas produced significantly more CH4 (0.0114 mg CH4-C m-2 hr-1) than deeper submerged areas (0.0011 mg CH4-C m-2 hr-1) (p\u3c0.0001) than areas dominated by either Typha latifolia (-0.0805 mg CH4-C m-2 hr-1) or Carex spp. (-0.0334 mg CH4-C m-2 hr-1). However, the effects of dominant emergent vegetation on flux lacked statistical significance. Findings from this study suggest the use of emergent macrophytes during future wetland creation promote oxygenation o f sediments and subsequent CH4 oxidation. Depth maximization of future wetland construction process is also suggested in order to minimize CH4 emission rates

    Alternative somatic cell count traits exploitable in genetic selection for mastitis resistance in Italian Holsteins

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    The aim of the present study was to characterize alternative somatic cell count (SCC) traits that could be exploited in genetic selection for mastitis resistance. Data were from 66,407 first-parity Holsteins in 404 herds. Novel SCC traits included average somatic cell score (SCS, log-transformation of SCC) in early lactation (SCS_150), standard deviation of SCS of the entire lactation (SCS_SD), the presence of at least one test-day (TD) SCC >400,000 cells/mL in the lactation, and the ratio of number of TD SCC >400,000 cells/mL to total number of TD in the lactation. Novel traits and lactation-mean SCS (SCS_LM) were analyzed using linear mixed or logistic regression models, including month of calving, year of calving, number of TD, and milk yield as fixed effects, and herd and residual as random terms. A multitrait linear animal model was applied to a random subset of 152 herds (n = 22,695 cows) to assess heritability of and genetic correlations between SCC traits. Alternative SCC traits were affected by the environmental factors included in the model; in particular, results suggested a seasonal effect and a tendency toward an improvement of the udder health status in the last years. Association was also found between novel SCC traits and milk production. Alternative SCC traits exhibited coefficients of additive genetic variation that were similar to or larger than that of traditional SCS_LM. Heritability of novel SCC traits was smaller than heritability of SCS_LM (0.126 \ub1 0.014), ranging from 0.044 \ub1 0.008 (SCS_SD) to 0.087 \ub1 0.010 (SCS_150). Genetic correlations between SCC traits ranged from 0.217 \ub1 0.096 (SCS_150 and SCS_SD) to 0.969 \ub1 0.010 (SCS_LM and SCS_150). Alternative SCC traits exhibited additive genetic variation that is potentially exploitable in breeding programs of Italian Holstein population to improve resistance to mastitis

    New distinguished classes of spectral spaces: a survey

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    In the present survey paper, we present several new classes of Hochster's spectral spaces "occurring in nature", actually in multiplicative ideal theory, and not linked to or realized in an explicit way by prime spectra of rings. The general setting is the space of the semistar operations (of finite type), endowed with a Zariski-like topology, which turns out to be a natural topological extension of the space of the overrings of an integral domain, endowed with a topology introduced by Zariski. One of the key tool is a recent characterization of spectral spaces, based on the ultrafilter topology, given in a paper by C. Finocchiaro in Comm. Algebra 2014. Several applications are also discussed

    Effect of heat stress on production in Mediterranean dairy sheep

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    European Mediterranean countries are characterized by exposure to considerable heat between three and six months annually. High ambient temperature, solar radiation, wind speed and relative humidity, cause the effective temperature of the environment to be above the thermo-neutral zone of the animals (5 to 25ºC; McDowell, 1972) and therefore heat stress occurs (Bianca, 1962)

    Second Order Phase Transitions : From Infinite to Finite Systems

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    We investigate the Equation of State (EOS) of classical systems having 300 and 512 particles confined in a box with periodic boundary conditions. We show that such a system, independently on the number of particles investigated, has a critical density of about 1/3 the ground state density and a critical temperature of about 2.5 MeV2.5~ MeV. The mass distribution at the critical point exhibits a power law with Ï„=2.23\tau = 2.23. Making use of the grand partition function of Fisher's droplet model, we obtain an analytical EOS around the critical point in good agreement with the one extracted from the numerical simulations.Comment: RevTex file, 17 pages + 9 figures available upon request from [email protected]

    COVID-19 and myocarditis: a systematic review and overview of current challenges

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    Myocardial inflammation in COVID-19 has been documented. Its pathogenesis is not fully elucidated, but the two main theories foresee a direct role of ACE2 receptor and a hyperimmune response, which may also lead to isolated presentation of COVID-19-mediated myocarditis. The frequency and prognostic impact of COVID-19-mediated myocarditis is unknown. This review aims to summarise current evidence on this topic. We performed a systematic review of MEDLINE and Cochrane Library (1/12/19–30/09/20). We also searched clinicaltrials.gov for unpublished studies testing therapies with potential implication for COVID-19-mediated cardiovascular complication. Eligible studies had laboratory confirmed COVID-19 and a clinical and/or histological diagnosis of myocarditis by ESC or WHO/ISFC criteria. Reports of 38 cases were included (26 male patients, 24 aged < 50 years). The first histologically proven case was a virus-negative lymphocytic myocarditis; however, biopsy evidence of myocarditis secondary to SARS-CoV-2 cardiotropism has been recently demonstrated. Histological data was found in 12 cases (8 EMB and 4 autopsies) and CMR was the main imaging modality to confirm a diagnosis of myocarditis (25 patients). There was a substantial variability in biventricular systolic function during the acute episode and in therapeutic regimen used. Five patients died in hospital. Cause-effect relationship between SARS-CoV-2 infection and myocarditis is difficult to demonstrate. However, current evidence demonstrates myocardial inflammation with or without direct cardiomyocyte damage, suggesting different pathophysiology mechanisms responsible of COVID-mediated myocarditis. Established clinical approaches should be pursued until future evidence support different actions. Large multicentre registries are advisable to elucidate further

    Nutritional interventions for patients with melanoma: From prevention to therapy—an update

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    Melanoma is an aggressive skin cancer, whose incidence rates have increased over the past few decades. Risk factors for melanoma are both intrinsic (genetic and familiar predisposition) and extrinsic (environment, including sun exposure, and lifestyle). The recent advent of targeted and immune-based therapies has revolutionized the treatment of melanoma, and research is focusing on strategies to optimize them. Obesity is an established risk factor for several cancer types, but its possible role in the etiology of melanoma is controversial. Body mass index, body surface area, and height have been related to the risk for cutaneous melanoma, although an ‘obesity paradox’ has been described too. Increasing evidence suggests the role of nutritional factors in the prevention and management of melanoma. Several studies have demonstrated the impact of dietary attitudes, specific foods, and nutrients both on the risk for melanoma and on the progression of the disease, via the effects on the oncological treatments. The aim of this narrative review was to summarize the main literature results regarding the preventive and therapeutic role of nutritional schemes, specific foods, and nutrients on melanoma incidence and progression

    Neutrino Properties Studied with a Triton Source Using Large TPC Detectors

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    The purpose of the present paper is to study the neutrino properties as they may appear in the low energy neutrinos emitted in triton decay, with maximum neutrino energy of 18.6 KeV. The technical challenges to this end can be summarized as building a very large TPC capable of detecting low energy recoils, down to a few 100 eV, within the required low background constraints. More specifically We propose the development of a spherical gaseous TPC of about 10-m in radius and a 200 Mcurie triton source in the center of curvature. One can list a number of exciting studies, concerning fundamental physics issues, that could be made using a large volume TPC and low energy antineutrinos:1) The oscillation length involving the small mixing angle in the electronic neutrino disappearancei experiment is comparable to the length of the detector. Measuring the counting rate of neutrino-electron elastic scattering will give a precise measurement of the oscillation parameters free of systematic errors. First estimations show that a sensitivity of a few percent for the measurement of the above angle. 2) The low energy detection threshold offers a unique sensitivity for the neutrino magnetic moment which is about two orders of magnitude beyond the current experimental limit. 3) Scattering at such low neutrino energies has never been studied and any departure from the expected behavior may be an indication of new physics beyond the standard model. We present results of theoretical calculation and studies of possible measurements.Comment: 30 LaTex pages and 9 figure
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