1,342 research outputs found

    Persistent Organic Pollutants (POPs) and inorganic elements in predatory bird livers and eggs 2007 to 2009: a Predatory Bird Monitoring Scheme (PBMS) Report

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    The Predatory Bird Monitoring Scheme (PBMS; http://pbms.ceh.ac.uk/) is the umbrella project that encompasses the Centre for Ecology & Hydrology’s National Capability contaminant monitoring and surveillance work on avian predators. By monitoring sentinel vertebrate species, the PBMS aims to detect and quantify current and emerging chemical threats to the environment and in particular to vertebrate wildlife. Sparrowhawk livers were analysed for a range of persistent organic pollutants (POPs) and heavy metals. Sparrowhawks are studied because they have a wide distribution across the Britain and can be used as a sentinel species for the terrestrial environment. Mean PCB and mercury liver concentrations were below those thought to have an adverse effect on individual birds. Pollutants, such as mercury and PCBs, can affect development and hatchability. Therefore, the PBMS also monitors the levels of contaminants in the eggs of a range of species including those of conservation concern, such as golden eagle and the re-introduced white-tailed sea eagle. Other species that are monitored are the northern gannet, which is used as a monitor of the marine environment, and merlin that hunts in upland habitats. The residues measured in the eggs of golden eagle and gannets collected between 2007 and 2009 were below those thought to have an adverse effect, but some residues in individual merlin eggs were above concentrations suggested to be indicative of no effect concentrations for birds generally. Few white-tailed see eagle eggs are received for analysis by the PBMS but many of the eggs that have been analysed, including one of the eggs analysed for this report, have DDE, PCB and/or mercury concentrations above levels associated with adverse effects on bird embryos and hatching success. In terms of long-term trends, there has been a decline in congener sum PCB contamination in the eggs of most of the species that have been monitored, except for coastal nesting golden eagles. In contrast however, there has been no significant decline over time in PCB concentrations in sparrowhawk livers and concentrations of ‘Paris 10’ congener sum and PCB-TEQ concentrations have also largely remained unchanged in both livers and eggs since monitoring began in 1996. Evidence for changes over time in mercury concentrations in predatory birds or their eggs is inconsistent across the species monitored. Where a decline has been detected, it has occurred before approximately 1990 and remained largely unchanged since then

    Avaliação funcional em pacientes com sequela pulmonar de tuberculose

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    ResumoIntroduçãoNa tuberculose pulmonar, a presença de lesões pulmonares residuais extensas pode ser um fator preditor de invalidez permanente por conta de insuficiência respiratória.ObjetivoComparar as alterações respiratórias e funcionais em pacientes com sequela pulmonar de tuberculose que finalizaram o tratamento.MétodoO estudo foi realizado no Ambulatório de Tisiologia do Hospital Sanatório Partenon. Foram incluídos no estudo pacientes que finalizaram único tratamento com 6 meses de duração (grupo I) e pacientes com tuberculose pulmonar multirresistente que finalizaram tratamento de maior duração após falência aos tratamentos iniciais (grupo II). Foram avaliadas a função pulmonar através da espirometria (ML 3500 Microlab, Microlab, EUA), a força dos músculos respiratórios através da manovacuometria e a distância percorrida no teste da caminhada dos 6 minutos (TC6M). Os dados foram analisados no programa SPSS versão 13.0, sendo utilizado o teste de qui-quadrado e o t para amostras independentes. O nível de significância adotado foi de 5%.ResultadosForam incluídos 27 pacientes sendo que 12 pertenciam ao grupo de tuberculose multirresistente. O distúrbio ventilatório mais prevalente no grupo de múltiplos tratamentos foi a obstrução grave, presente em 9 pacientes. O grupo que realizou múltiplos tratamentos (grupo II) apresentou redução significativa quando comparado ao grupo I nas variáveis CVF (72,06±14,95 vs. 43,58±16,03% predito), VEF1 (66,13±19,87 vs. 33,08±15,64% predito), PImax (68,40±22,78 vs. 49,58±12,55 cmH2O), PEmax (87,20±27,30 vs. 59,08±12,23 cmH2O) e distância percorrida no TC6M (484,21±74,01 vs. 334,75±104,07 metros).ConclusãoPacientes com tuberculose pulmonar multirresistente que realizaram múltiplos tratamentos apresentam comprometimentos respiratórios e funcionais maiores do que pacientes que realizaram único tratamento.AbstractIntroductionIn pulmonary tuberculosis, the presence of extensive residual lung lesions can be a predictor of permanent disability due to respiratory failure.ObjectiveTo compare functional and respiratory changes in patients with pulmonary tuberculosis sequel who have completed treatment.MethodThe study included patients who completed treatment within a period of 6 months (group I) and multidrug-resistant pulmonary tuberculosis patients who completed treatments of longer duration after the failure of the initial treatment (group II). We evaluated lung function by spirometry (Microlab ML 3500), the strength of respiratory muscles through the manovacuometry (MEP-maximal expiratory pressure and MIP- maximal inspiratory pressure) and the distance walked during the 6-minute walk (6MWT).Results27 patients were included, 12 of whom belonged to group II, multidrug-resistant tuberculosis (MDRTB). Severe combined respiratory disorder was the most prevalent problem in group II of MDRTB; it was present in 9 patients. The MDRTB group (group II) showed significantly lower values when compared to Group I in FVC (72.06±14.95 vs 43.58±16.03% predicted), FEV1 (66.13±19.87 vs 33.08±15.64% predicted), MIP (68.40±22.78 vs 49.58±12.55 cmH2O), MEP (87.20±27.30 vs 59.08±12.23 cmH2O) and distance covered in 6MWT (484.21±74.01 vs 334.75±104.07 meters).ConclusionPatients with multidrug resistant pulmonary tuberculosis who have undergone multiple treatments have more severe respiratory and functional impairment than patients who have had just a single treatment

    Purely-long-range bound states of He(2s3S)+(2s ^3S)+He(2p3P)(2p ^3P)

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    We predict the presence and positions of purely-long-range bound states of 4^4He(2s3S)+4(2s ^3S)+{}^4He(2p3P)(2p ^3P) near the 2s3S1+2p3P0,12s ^3S_1+2p ^3P_{0,1} atomic limits. The results of the full multichannel and approximate models are compared, and we assess the sensitivity of the bound states to atomic parameters characterizing the potentials. Photoassociation to these purely-long-range molecular bound states may improve the knowledge of the scattering length associated with the collisions of two ultracold spin-polarized 4^4He(2s3S)(2s ^3S) atoms, which is important for studies of Bose-Einstein condensates.Comment: 16 pages, 5 figure

    Measurement of the 58Ni(α, γ) 62Zn reaction and its astrophysical impact

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    Funding Details: PHY 08-22648, NSF, National Science Foundation; PHY 0969058, NSF, National Science Foundation; PHY 1102511, NSF, National Science FoundationCross section measurements of the 58Ni(α,γ)62Zn reaction were performed in the energy range Eα=5.5to9.5 MeV at the Nuclear Science Laboratory of the University of Notre Dame, using the NSCL Summing NaI(Tl) detector and the γ-summing technique. The measurements are compared to predictions in the statistical Hauser-Feshbach model of nuclear reactions using the SMARAGD code. It is found that the energy dependence of the cross section is reproduced well but the absolute value is overestimated by the prediction. This can be remedied by rescaling the α width by a factor of 0.45. Stellar reactivities were calculated with the rescaled α width and their impact on nucleosynthesis in type Ia supernovae has been studied. It is found that the resulting abundances change by up to 5% when using the new reactivities. © 2014 American Physical Society.Peer reviewe

    Spatial antibunching of photons with parametric down-conversion

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    The theoretical framework behind a recent experiment by Nogueira et. al. [Phys. Rev. Lett. 86}, 4009 (2001)] of spatial antibunching in a two-photon state generated by collinear type II parametric down-conversion and a birefringent double-slit is presented. The fourth-order quantum correlation function is evaluated and shown to violate the classical Schwarz-type inequality, ensuring that the field does not have a classical analog. We expect these results to be useful in the rapidly growing fields of quantum imaging and quantum information.Comment: 5 pages, 3 figures. Minor changes made, accepted for publication in PR

    Nonextensive statistical effects in protoneutron stars

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    We investigate the bulk properties of protoneutron stars in the framework of a relativistic mean field theory based on nonextensive statistical mechanics, characterized by power-law quantum distributions. We study the relevance of nonextensive statistical effects on the beta-stable equation of state at fixed entropy per baryon, in presence and in absence of trapped neutrinos, for nucleonic and hyperonic matter. We show that nonextensive statistical effects could play a crucial role in the structure and in the evolution of the protoneutron stars also for small deviations from the standard Boltzmann-Gibbs statistics.Comment: 9 pages, 7 figure

    Generalised second law of thermodynamics for interacting dark energy in the DGP brane world

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    In this paper, we investigate the validity of the generalized second law of thermodynamics (GSLT) in the DGP brane world when universe is filled with interacting two fluid system: one in the form of cold dark matter and other is holographic dark energy. The boundary of the universe is assumed to be enclosed by the dynamical apparent horizon or the event horizon. The universe is chosen to be homogeneous and isotropic FRW model and the validity of the first law has been assumed here

    Modulation of the gut microbiota of Pacific white shrimp ( Penaeus vannamei Boone, 1931) by dietary inclusion of a functional yeast cell wall‐based additive

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    Several eco-friendly natural substances can enhance the shrimp immune defence system therby acting as a prophylactic agent in feed additives. Agents such as (1, 3)-(1, 6)-D β-glucan and complex mannan-oligosaccharides located in yeast cell walls present such immunomodulatory and potential prebiotic properties. The aim of our study was to evaluate the effect of a commercial yeast cell wall extract (YCW) on shrimp performance and health status, and influence on gut microbiota. Juvenile Penaeus vannamei (Boone, 1931) were raised at an intensive shrimp farm and fed with two different diet inclusions levels of YCW, that is, 0.5% and 1.0%, in addition to a yeast free control group. After 102 days, animals were sampled, and standard nutrition performance parameters were measured. Additionally, the phylogenetic profile and composition of shrimp gut microbiota were evaluated. Animal performance, including growth and survival, was significantly better on animals fed with YCW than the control group. Furthermore, beneficial bacteria phylotypes were stimulated by the presence of YCW, positively modulating the gut microbiota, with emphasis on 1.0% YCW treatment. Therefore, YCW can be regarded as a prophylactic functional agent in the intensive rearing of juvenile P. vannamei thus improving animal performance and contributing to a healthy intestinal microbiota

    A Green's function approach to transmission of massless Dirac fermions in graphene through an array of random scatterers

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    We consider the transmission of massless Dirac fermions through an array of short range scatterers which are modeled as randomly positioned δ\delta- function like potentials along the x-axis. We particularly discuss the interplay between disorder-induced localization that is the hallmark of a non-relativistic system and two important properties of such massless Dirac fermions, namely, complete transmission at normal incidence and periodic dependence of transmission coefficient on the strength of the barrier that leads to a periodic resonant transmission. This leads to two different types of conductance behavior as a function of the system size at the resonant and the off-resonance strengths of the delta function potential. We explain this behavior of the conductance in terms of the transmission through a pair of such barriers using a Green's function based approach. The method helps to understand such disordered transport in terms of well known optical phenomena such as Fabry Perot resonances.Comment: 22 double spaced single column pages. 15 .eps figure
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