1,429 research outputs found
Determinação do nitrogênio da biomassa microbiana do solo (BMS-N).
Materiais e equipamentos necessários; Para fumigação; Para extração; Para determinação do nitrogênio microbiano; Amsotra; Limitações do método; Procedimento; Preparação da amostra; Determinação da umidade na capacidade de campo do solo; Procedimento analítico; Determinação da umidade do solo; Fumigação; Extração; Determinação do nitrogênio microbiano; Cálculo da molaridade exata da solução de ácido sulfúrico (H2S04) 0,015M; Cálculo do teor de N nos extratos (Equação 4); Cálculo da BMS-N; Equação 5.bitstream/CNPAB-2010/34388/1/cot096.pdfParceria: UFRR
Microbial soil quality indicators under different crop rotations and tillage management.
An experiment was carried out under field conditions to assess the effects of soil management (no-tillage- NT and conventional tillage- CT) and crop rotation systems on microbial biomass-C (Cmic), basal soil respiration (BSR), metabolic quotient (qCO2), soil organic carbon content (Corg) and microbial carbon to organic carbon ratio (Cmic/Corg). Soil samples were collected on an area cultivated with wheat as winter crop and soybean as summer crop, both in rotation with vetch, maize and oats. Samples were also collected in a secondary forest used as reference. Data of each management system (NT and CT) were compared to forest area by ?t? test (p<0.05) and crop rotations were compared by Tukey test (p<0.05). All data were submitted to multivariate analysis (Principal Component Analysis - PCA). There were observed significant differences (?t? test; p<0.05) for Cmic, BSR, qCO2 and Cmic/Corg between NT and CT, by which NT values resemble those for forest area. For crop rotations significant differences (Tukey test; p<0.05) were found only for BSR and qCO2. The sum of the two first principal components on the PCA explained about 75% of the data variation. PCA showed NT closest to forest area than CT, especially treatments with soybean and vetch as consecutive crops. The forest area-NT clustering was mostly due to Cmic and Cmic/Corg relationship. Results indicate that the NT system is more sustainable than the CT system and can contribute for the accumulation a greater quantity of carbon in soil
Recommended from our members
Response Monitoring, Repetitive Behaviour and Anterior Cingulate Abnormalities in Autism Spectrum Disorders (ASD)
Autism spectrum disorders (ASD) are characterized by inflexible and repetitive behaviour. Response monitoring involves evaluating the consequences of behaviour and making adjustments to optimize outcomes. Deficiencies in this function, and abnormalities in the anterior cingulate cortex (ACC) on which it relies, have been reported as contributing factors to autistic disorders. We investigated whether ACC structure and function during response monitoring were associated with repetitive behaviour in ASD. We compared ACC activation to correct and erroneous antisaccades using rapid presentation event-related functional MRI in 14 control and ten ASD participants. Because response monitoring is the product of coordinated activity in ACC networks, we also examined the microstructural integrity of the white matter (WM) underlying this brain region using diffusion tensor imaging (DTI) measures of fractional anisotropy (FA) in 12 control and 12 adult ASD participants. ACC activation and FA were examined in relation to Autism Diagnostic Interview-Revised ratings of restricted and repetitive behaviour. Relative to controls, ASD participants: (i) made more antisaccade errors and responded more quickly on correct trials; (ii) showed reduced discrimination between error and correct responses in rostral ACC (rACC), which was primarily due to (iii) abnormally increased activation on correct trials and (iv) showed reduced FA in WM underlying ACC. Finally, in ASD (v) increased activation on correct trials and reduced FA in rACC WM were related to higher ratings of repetitive behaviour. These findings demonstrate functional and structural abnormalities of the ACC in ASD that may contribute to repetitive behaviour. rACC activity following errors is thought to reflect affective appraisal of the error. Thus, the hyperactive rACC response to correct trials can be interpreted as a misleading affective signal that something is awry, which may trigger repetitive attempts at correction. Another possible consequence of reduced affective discrimination between error and correct responses is that it might interfere with the reinforcement of responses that optimize outcomes. Furthermore, dysconnection of the ACC, as suggested by reduced FA, to regions involved in behavioural control might impair on-line modulations of response speed to optimize performance (i.e. speed-accuracy trade-off) and increase error likelihood. These findings suggest that in ASD, structural and functional abnormalities of the ACC compromise response monitoring and thereby contribute to behaviour that is rigid and repetitive rather than flexible and responsive to contingencies. Illuminating the mechanisms and clinical significance of abnormal response monitoring in ASD represents a fruitful avenue for further research
Relevant Professional Development: Reflective of Adult Learning Styles
This action research project was instigated to determine the effects of professional development (PD) for practicing Montessori teachers using the Montessori Language materials. The specific targeted materials included: vocabulary cards, sound analysis, sandpaper letters, moveable alphabet, pencil use, and reading. The research took place during a four week period in a large west coast Montessori school that serves children between 18 months and 12 years old. The teachers who participated in the study all worked with children between the ages of 3 – 6 years old. The data was collected using a provider journal (notes taken by the researcher during the PD sessions), questionnaires and weekly teacher logs. The researcher used available PD literature to plan and execute the study, which highlighted the importance of teachers participating in PD that was designed around participant identified content. The literature also provided guidance as to the content methods to incorporate into the PD sessions. At the conclusion of the study, findings revealed that the teachers benefited from support in all the language categories listed. They also became aware of the content delivery methods that best met their individual needs. Future research is needed to determine the content and delivery needs of teachers in different stages of their careers. Keywords
Fertilizantes de leguminosas como fontes alternativas de nitrogênio para produção orgânica de alface.
O objetivo deste trabalho foi avaliar o potencial de dois fertilizantes de leguminosas - produtos derivados do corte, desidratação e moagem da biomassa aérea das leguminosas mucuna-cinza (Mucuna pruriens) e gliricídia (Gliricidia sepium) - como fontes alternativas de nitrogênio (N) para a produção orgânica de alface (Lactuca sativa cv. Vera), e a influência dessas adubações sobre a vida útil pós-colheita da hortaliça, em condições de laboratório. Esses fertilizantes foram empregados em cobertura e comparados com cama-de-aviário industrial, assegurando-se doses equivalentes de N total. O delineamento experimental foi o de blocos ao acaso, com cinco tratamentos e quatro repetições: T1: adubação pré-plantio, com termofosfato sílico-magnesiano + sulfato de potássio; T2: T1 + esterco bovino, em pré-plantio; T3: T2 + fertilizante de mucuna-cinza, em cobertura; T4: T2 + fertilizante de gliricídia, em cobertura; T5: T2 + cama-de-aviário em cobertura. Não houve diferença entre os fertilizantes de ambas as espécies de leguminosas e a cama-de-aviário, quanto à produtividade, teor de N, padrão comercial e período de vida útil pós-colheita das alfaces, o que indica potencial de uso desses fertilizantes como fontes de N para sistemas orgânicos de produção de hortaliças. The objective of this work was to evaluate the potential use of two legume fertilizers - products derived from cutting, dehydration and milling of the aerial biomass of legume plants, velvet bean (Mucuna pruriens) and gliricidia (Gliricidia sepium) - as alternative sources of N for organic production of lettuce (Lactuca sativa cv. Vera); and to evaluate the influence of soil fertilization on lettuce shelf life at laboratory bench condition. These fertilizers were applied on soil surface and compared to factory poultry-bed manure at equivalent total N doses. The experimental design consisted of randomized blocks with five treatments and four replications, as following: T1: pre-planting fertilization with magnesium thermophosphate + potassium sulphate; T2: T1 + cattle manure in pre-planting; T3: T2 + velvet bean fertilizer in covering; T4: T2 + gliricidia fertilizer in covering; and T5: T2 + poultry-bed manure in covering. Fertilizers of both legume species were not statistically different of poultry-bed manure, regarding productivity, N content, commercial standard and shelf life of lettuce, which indicates promising potential for their use in organic horticultural production systems.Parceria: UFRRJ
Biowaiver Monographs for Immediate‐Release Solid Oral Dosage Forms: Codeine Phosphate
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106898/1/jps23977.pd
Quasi-elastic and inelastic inclusive electron scattering from an oxygen jet target
The results of an experiment on inclusive electron scattering from an oxygen
jet target, performed in a wide range of energy and momentum transfer covering
both quasi-elastic and (1232) resonance regions, are reported. In the
former region the theoretical predictions, obtained including effects of
nucleon-nucleon correlations in both initial and final states, give a good
description of the experimental data. In the inelastic region a broadening as
well as a damping of the resonant part of the cross section with respect to the
free nucleon case is observed. The need of more detailed calculations including
nuclear structure effects on the electroproduction cross section of nucleon
resonances is highlighted.Comment: to appear in Nucl. Phys.
Predicting Treatment Response in Social Anxiety Disorder From Functional Magnetic Resonance Imaging
Context: Current behavioral measures poorly predict treatment outcome in social anxiety disorder (SAD). To our knowledge, this is the first study to examine neuroimaging-based treatment prediction in SAD.
Objective: To measure brain activation in patients with SAD as a biomarker to predict subsequent response to cognitive behavioral therapy (CBT).
Design: Functional magnetic resonance imaging (fMRI) data were collected prior to CBT intervention. Changes in clinical status were regressed on brain responses and tested for selectivity for social stimuli.
Setting: Patients were treated with protocol-based CBT at anxiety disorder programs at Boston University or Massachusetts General Hospital and underwent neuroimaging data collection at Massachusetts Institute of Technology.
Patients: Thirty-nine medication-free patients meeting DSM-IV criteria for the generalized subtype of SAD.
Interventions: Brain responses to angry vs neutral faces or emotional vs neutral scenes were examined with fMRI prior to initiation of CBT.
Main Outcome Measures: Whole-brain regression analyses with differential fMRI responses for angry vs neutral faces and changes in Liebowitz Social Anxiety Scale score as the treatment outcome measure.
Results: Pretreatment responses significantly predicted subsequent treatment outcome of patients selectively for social stimuli and particularly in regions of higher-order visual cortex. Combining the brain measures with information on clinical severity accounted for more than 40% of the variance in treatment response and substantially exceeded predictions based on clinical measures at baseline. Prediction success was unaffected by testing for potential confounding factors such as depression severity at baseline.
Conclusions: The results suggest that brain imaging can provide biomarkers that substantially improve predictions for the success of cognitive behavioral interventions and more generally suggest that such biomarkers may offer evidence-based, personalized medicine approaches for optimally selecting among treatment options for a patient
A Study of the Formation of Single- and Double-Walled Carbon Nanotubes by a CVD Method
The reduction in H2/CH4 atmosphere of aluminum-iron oxides produces metal particles small enough to catalyze the formation of single-walled carbon nanotubes. Several experiments have been made using the same temperature profile and changing only the maximum temperature (800-1070 °C). Characterizations of the catalyst materials are performed using notably 57Fe Mo¨ssbauer spectroscopy. Electron microscopy and a macroscopical method are used to characterize the nanotubes. The nature of the iron species (Fe3+, R-Fe, ç-Fe-C, Fe3C) is correlated to their location in the material. The nature of the particles responsible for the high-temperature formation of the nanotubes is probably an Fe-C alloy which is, however, found as Fe3C by postreaction analysis. Increasing the reduction temperature increases the reduction yield and thus favors the formation of surface-metal particles, thus producing more nanotubes. The obtained carbon nanotubes are mostly single-walled and double-walled with an average diameter close to 2.5 nm. Several formation mechanisms are thought to be active. In particular, it is shown that the second wall can grow inside the first one but that subsequent ones are formed outside. It is also possible that under given experimental conditions, the smallest (<2 nm) catalyst particles preferentially produce double-walled rather than single-walled carbon nanotubes
- …
