1,913 research outputs found
Using earthworms as bioindicators of quality in no-till systems.
No Brasil, o plantio direto é o sistema de manejo do solo mais praticado. Dentre os diversos benefícios, o plantio direto promove as funções dos organismos, especialmente as minhocas, sobre a fertilidade do solo. Portanto, o presente estudo teve como objetivo avaliar as populações de minhocas, visando uma classificação da densidade e diversidade de minhocas em áreas sob plantio direto. As coletadas foram realizadas em fevereiro/março de 2010 e 2011, num total de 34 e 25 propriedades respectivamente em seis municípios da Bacia do Paraná 3, parte da bacia do lago de Itaipu. As minhocas foram amostradas no final da estação chuvosa, utilizando uma adaptação do Método para Biologia e Fertilidade em Solos Tropicais (TSBF), consistindo na coleta de 5 monolitos de 20 x 20 por 20 cm de profundidade, espaçados por mínimo 20 m um do outro, em um transecto linear. Foi realizada triagem manual no campo e as minhocas foram estocadas em sacos plásticos contendo solução de formaldeído 5%. As minhocas foram contadas e identificadas em nível de família, gênero e espécies. A simplificação da metodologia de amostragem objetivou possibilitar que os próprios agricultores avaliem as populações de minhocas em suas propriedades. A abundância de minhocas variou de 5 a 600 ind m-2 e 5 a 1150 ind m-2, respectivamente nas épocas de coletas em 2010 e 2011, enquanto o número de espécies variou de uma a seis em 2010 e de uma a sete em 2011 nas áreas sob plantio direto. Baseado neste estudo e em resultados de outros estudos anteriores, uma classificação para abundância e diversidade de minhocas em áreas sob plantio direto é proposta aqui, para Latossolos Vermelhos e regiões de clima quente do Paraná (Cfa Koeppen) : pobre >25 ind m-2 and 1 sp.; moderado ? 25 to 6 sp.Disponível online
Exploring the Landscape of Inclusion: Profiles of Inclusive versus Segregated School Districts in the United States
Although inclusive education has been increasing in frequency for students with disabilities in the
United States, for many students, the opportunity to be educated with their peers without disabilities
continues to be out of reach despite decades of efforts by those promoting the vision of inclusion. This
exploratory case study used interviews with administrators, teachers, and parents representing inclusive
and segregated school districts in one state to explore potential reasons for differences in districts that
had high percentages of students with disabilities in inclusive versus segregated educational settings.
The importance of administrative leadership and parent selective mobility were found to influence the
extent to which a district implemented inclusive versus segregated placements for students with
disabilities
Factors that affect proliferation of Salmonella in tomatoes post-harvest: the roles of seasonal effects, irrigation regime, crop and pathogen genotype
MAIN OBJECTIVES: Fresh fruits and vegetables become increasingly recognized as vehicles of human salmonellosis. Physiological, ecological, and environmental factors are all thought to contribute to the ability of Salmonella to colonize fruits and vegetables pre- and post-harvest. The goal of this study was to test how irrigation levels, fruit water congestion, crop and pathogen genotypes affect the ability of Salmonella to multiply in tomatoes post-harvest. EXPERIMENTAL DESIGN: Fruits from three tomato varieties, grown over three production seasons in two Florida locations, were infected with seven strains of Salmonella and their ability to multiply post-harvest in field-grown tomatoes was tested. The field experiments were set up as a two-factor factorial split plot experiment, with the whole-plot treatments arranged in a randomized complete-block design. The irrigation treatment (at three levels) was the whole-plot factor, and the split-plot factor was tomato variety, with three levels. The significance of the main, two-way, and three-way interaction effects was tested using the (type III) F-tests for fixed effects. Mean separation for each significant fixed effect in the model was performed using Tukey's multiple comparison testing procedure. MOST IMPORTANT DISCOVERIES AND SIGNIFICANCE: The irrigation regime per se did not affect susceptibility of the crop to post-harvest proliferation of Salmonella. However, Salmonella grew significantly better in water-congested tissues of green tomatoes. Tomato maturity and genotype, Salmonella genotype, and inter-seasonal differences were the strongest factors affecting proliferation. Red ripe tomatoes were significantly and consistently more conducive to proliferation of Salmonella. Tomatoes harvested in the driest, sunniest season were the most conducive to post-harvest proliferation of the pathogen. Statistically significant interactions between production conditions affected post-harvest susceptibility of the crop to the pathogen. UV irradiation of tomatoes post-harvest promoted Salmonella growth
Genotyping of putative Urobenus brasiliensis Benham, 1886 (Clitellata: Rhinodrilidae) validates geographically clustered cryptic lineages including the type locality population.
ISEE 10
MOBSTER – III. HD 62658: a magnetic Bp star in an eclipsing binary with a non-magnetic ‘identical twin’
HD 62658 (B9p V) is a little-studied chemically peculiar star. Light curves obtained by the Kilodegree Extremely Little Telescope (KELT) and Transiting Exoplanet Survey Satellite (TESS) show clear eclipses with a period of about 4.75 d, as well as out-of-eclipse brightness modulation with the same 4.75 d period, consistent with synchronized rotational modulation of surface chemical spots. High-resolution ESPaDOnS circular spectropolarimetry shows a clear Zeeman signature in the line profile of the primary; there is no indication of a magnetic field in the secondary. PHOEBE modelling of the light curve and radial velocities indicates that the two components have almost identical masses of about 3 M_⊙. The primary’s longitudinal magnetic field〈B_z〉 varies between about +100 and −250 G, suggesting a surface magnetic dipole strength B_d = 850 G. Bayesian analysis of the Stokes V profiles indicates B_d = 650 G for the primary and B_d < 110 G for the secondary. The primary’s line profiles are highly variable, consistent with the hypothesis that the out-of-eclipse brightness modulation is a consequence of rotational modulation of that star’s chemical spots. We also detect a residual signal in the light curve after removal of the orbital and rotational modulations, which might be pulsational in origin; this could be consistent with the weak line profile variability of the secondary. This system represents an excellent opportunity to examine the consequences of magnetic fields for stellar structure via comparison of two stars that are essentially identical with the exception that one is magnetic. The existence of such a system furthermore suggests that purely environmental explanations for the origin of fossil magnetic fields are incomplete
NN interaction in a Goldstone boson exchange model
Adiabatic nucleon-nucleon potentials are calculated in a six-quark
nonrelativistic chiral constituent quark model where the Hamiltonian contains a
linear confinement and a pseudoscalar meson (Goldstone boson) exchange
interaction between quarks. Calculations are performed both in a cluster model
and a molecular orbital basis, through coupled channels. In both cases the
potentials present an important hard core at short distances, explained through
the dominance of the [51]_{FS} configuration, but do not exhibit an attractive
pocket. We add a scalar meson exchange interaction and show how it can account
for some middle-range attraction.Comment: 32 pages with 12 eps figures incorporated, RevTeX. Final version
published in PR
An Unusual Location of Deep Venous Thrombosis Associated with Ischemic Stroke and Persistent Foramen Ovale
Up to 40% of ischemic strokes have no known cause (cryptogenic). The prevalence of persistent foramen ovale (PFO) amongst patients with cryptogenic stroke (CS) is twice as high as that of the normal population, therefore suggesting a causal relationship between the two entities. However, PFO by itself is not sufficient to cause stroke, as an embolic source is needed. This source is often unknown, making the causal relationship between CS and PFO hard to demonstrate. The most frequent, although still seldom, identifiable cause of embolism in an otherwise cryptogenic stroke associated with PFO is a deep venous thrombosis (DVT) of the lower extremities. Here, we present a unique case of brachiocephalic venous DVT associated with PFO and ischemic stroke in a young patient. As the search for DVT in patients with PFO and stroke is often limited to the lower extremities, this case may suggest that an unspecified number of DVTs are overlooked. Our report lends support to paradoxical embolism as a mechanism of stroke in patients with PFO and does, at least in selected cases, suggest a more detailed search for DVT beyond the lower extremities
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