Composition and quality of harvest residues and soil organic matter under windrow residue management in young hoop pine plantations as revealed by solid-state C-13 NMR spectroscopy

Solid-state C-13 nuclear magnetic resonance (NMR) with cross-polarisation (CP) and magic-angle-spinning (MAS) was used to: (a) examine the changes in carbon (C) composition of windrowed harvest residues during the first 3 years of hoop pine plantations in subtropical Australia; (b) assess the impacts of windrowed harvest residues on soil organic matter (SOM) composition and quality in the 0-10 cm soil layer. Harvest residues were collected from 0-, 1-, 2- and 3-year-old windrows of ca. 2.5 m width (15 m apart for 0-, 1- and 2-year-old sites and 10 m apart for 3-year-old site). Soils from the 0 to 10 cm soil layer were collected from the 1-, 2- and 3-year-old sites. The 13C NMR spectra of the harvest residues indicated the presence of lignin in the hoop pine wood, foliage and newly incorporated organic matter (NIOM). Condensed tannin structures were found in the decay-resistant bark, small wood and foliage, but were absent in other residue components and SOM. The NMR spectra of small wood samples contained condensed tannin structures because the outer layer of bark was not removed. NIOM showed a shift from foliage-like structures (celluloses) to lignin-type structures, indicating an incorporation of woody residues from the decomposing harvest residues. Suberins were also present in the small wood, foliage and bark. The 13C CP NMR spectra of SOM indicated that in areas where windrows were present, SOM did not show compositional changes. However, an increase in SOM quality under the windrows in the second year after their formation as characterised by the alkyl C/O-alkyl C (A/O-A) ratio was mainly due to inputs from the decomposition of the labile, readily available components of the windrowed harvest residues. (C) 2002 Published by Elsevier Science B.V.

Genotype and environment effects on dynamics of harvest index during grain filling in sorghum

An approach based on a linear rate of increase in harvest index (141) with time after anthesis has been used as a simple means-to predict grain growth and yield in many crop simulation models. When applied to diverse situations, however, this approach has been found to introduce significant error in grain yield predictions. Accordingly, this study was undertaken to examine the stability of the HI approach for yield prediction in sorghum [Sorghum bicolor (L.) Moench]. Four field experiments were conducted under nonlimiting water. and N conditions. The experiments were sown at times that ensured a broad range in temperature and radiation conditions. Treatments consisted of two population densities and three genotypes varying in maturity. Frequent sequential harvests were used to monitor crop growth, yield, and the dynamics of 111. Experiments varied greatly in yield and final HI. There was also a tendency for lower HI with later maturity. Harvest index dynamics also varied among experiments and, to a lesser extent, among treatments within experiments. The variation was associated mostly with the linear rate of increase in HI and timing of cessation of that increase. The average rate of HI increase was 0.0198 d(-1), but this was reduced considerably (0.0147) in one experiment that matured in cool conditions. The variations found in IN dynamics could be largely explained by differences in assimilation during grain filling and remobilization of preanthesis assimilate. We concluded that this level of variation in HI dynamics limited the general applicability of the HI approach in yield prediction and suggested a potential alternative for testing.

Effect of time of harvest of budded virus on the selection of baculovirus FP mutants in cell culture

Rapid formation and selection of FP (few polyhedra) mutants occurs during serial passaging of Helicoverpa armigera nucleopolyhedrovirus (HaSNPV) in insect cell culture. The production of HaSNPV for use as biopesticides requires the passaging of the virus over a number of passages to produce enough virus inoculum for large-scale fermentation. During serial passaging in cell culture, FP mutants were rapidly selected, resulting in declined productivity and reduced potency of virus. Budded virus (BV) is usually harvested between 72 and 96 h postinfection (hpi) in order to obtain a high titer virus stock. In this study, the effect of tine of harvest (TOH) for BV on the selection rate of HaSNPV FP mutants during serial passaging was investigated. BV were harvested at different times postinfection, and each series was serially passaged for six passages. The productivity and percentage of FP mutants at each passage were determined. It was found that the selection of FP mutants can he reduced by employing an earlier TOH for BV. Serial passaging with BV harvested at 48 hpi showed a slower accumulation of FP mutants compared to that of BV harvested after 48 hpi. Higher cell specific yields were also maintained when BV were harvested at 48 hpi. When BV that were formed between 48 and 96 hpi were harvested and serially passaged, FP mutants quickly dominated the virus population. This suggests that the V formed and released between 48 and 96 hpi are most likely from FP mutant infected cells.

Sistem??tica de avalia????o e prioriza????o de investimentos em equipamentos

Sistem??tica de planejamento de investimentos para o hospital universit??rio com a cria????o de um Plano Diretor de Investimentos em Equipamentos que leva em considera????o o contexto de alta complexidade do ambiente e visa atender ??s necessidades de envolvimento e participa????o dos profissionais das diversas ??reas. Os crit??rios criados para a prioriza????o dos investimentos avaliam a contribui????o para otimizar a renda/produtividade, a viabilidade de implanta????o, a contribui????o ao desenvolvimento da excel??ncia, a prioridade de cada investimento no Servi??o e a criticidade do investimento. Hoje, os investimentos em equipamentos est??o sendo adquiridos conforme a prioridade que a comunidade interna definiu, dentro de uma avalia????o objetiva de cada investimento

Efetividade no estorno de medicamentos: otimiza????o de uma sistem??tica para a aplica????o correta do dinheiro p??blico e maior seguran??a aos pacientes

A Farm??cia de Dispensa????o do Hospital de Cl??nicas de Porto Alegre identificou a necessidade de otimizar o estorno dos medicamentos prescritos aos pacientes internados, evitando o desperd??cio e aumentando a seguran??a de sua distribui????o aos pacientes por parte das equipes de enfermagem. O processo mecanizado de embalar e identificar, em conjunto com a busca ativa dos medicamentos n??o utilizados, garantiu mais seguran??a na dispensa????o e ministra????o dos medicamentos prescritos aos pacientes, e uma redu????o de 40% destes itens de consumo

Post-harvest conservation of organic strawberries coated with cassava starch and chitosan

The strawberry is as non-climacteric fruit, but has a high post-harvest respiration rate, which leads to a rapid deterioration at room temperature. This study aimed to evaluate the application of biodegradable coating on postharvest conservation of organic strawberries, cv. Camarosa, packed in plastic hinged boxes and stored at 10ºC. The treatments consisted of: a) control; b) 2% cassava starch; c) 1% chitosan; and d) 2% cassava starch + 1% chitosan. Physical and chemical characteristics of fruits were evaluated at 3, 6 and 9 days of storage, and microbiological and sensory analyses were carried out at the end of the storage period. The treatments influenced positively the post-harvest quality of organic strawberries. The coating cassava starch + chitosan provided the best results, with less than 6% of loss in fruit mass, lower counts of yeast and psychrophilic microorganisms and the best appearance according to the sensory analysis.

Influence of the use of acids and films in post-harvest lychee conservation

Lychee (Litchi chinensis Sonn.) has a high commercial value; however, it has a short shelf-life because of its rapid pericarp browning. The objective of this study was to evaluate the shelf-life of 'Bengal' lychee fruits stored after treatment with hydrochloric acid and citric acid, associated with cassava starch and plastic packaging. Uniformly red pericarp fruits were submitted to treatments: 1-(immersion in citric acid 100 mM for 5 minutes + cassava starch 30 g L-1 for 5 minutes), 2-(immersion in hydrochloric acid 1 M for 2 minutes + starch cassava 30 g L-1 for 5 minutes), 3-(immersion in citric acid 100 mM for 5 minutes + polyvinyl chloride film (PVC, 14 µm thick)) and 4-(immersion in hydrochloric acid 1 M for 2 minutes + PVC film). During 20 days, the fruits were evaluated for mass loss, pericarp color, pH, soluble solids and titratable acidity, vitamin C of the pulp and pericarp and activities of polyphenol oxidase and peroxidase of the pericarp. The treatment with hydrochloric acid associated with PVC was the most effective in maintaining the red color of the pericarp for a period of 20 days and best preservation of the fruit. The cassava starch associated with citric acid, and hydrochloric acid did not reduce the mass loss and did not prevent the browning of lychee fruit pericarp.

Growth and yield of Coffea arabica L. in Northwest Fluminense: 2nd harvest

In recent years, several new coffee cultivars recommended for different regions have been released. However, the performance of these varieties in many traditionally producing regions is unknown. Difference of climate and soil may jeopardize the productivity of the new cultivars and cause losses to farmers. The objective of this study is to evaluate the vegetative growth and productive genotypes of C. arabica in the conditions of the Northwestern Rio de Janeiro State, Brazil. The experiment was settled in 2007, in Panorama 1 Farm, located in the municipality of Varre Sai, RJ. Twenty-five genotypes of C. arabica were planted in a spacing of 2.5 × 0.8 m, using a completely randomized design with five replications and eight plants per plot. There were eight measurements of vegetative growth represented by plant height, stem diameter and number of plagiotropic branches. Assessments of productivity were also performed in years 2009 and 2010. There was a positive phenotypic correlation among vegetative characteristics and between vegetative characteristics and yield in the first harvest, while in the second harvest only the number of plagiotropic branches was positively correlated with yield. Up to date, the genotypes Catucaí amarelo 2 SL, Catiguá MG 02, Acauã, Palma II, Sabiá 398, IPR 103/ Iapar, IPR 100/Iapar, H 419-10-6-2-12-1, Catucaí amarelo 24 / 137, Iapar 59, Catucaí amarelo 20/15, H 419-10-6-2-5-10-1 and H 419-10-6-2-5-1 had the highest average yield after two harvests.

Effects of levels of potassium and nitrogen on yields and post-harvest conservation of onions in winter

Potassium and nitrogen are the elements present in the highest percentage in the onion dry matter. The objective of this experiment was to evaluate yield and post-harvest conservation of Vale Ouro IPA-11 onion cultivar regarding to nitrogen and potassium levels. The experiment was carried out in Petrolina-PE, Brazil, from June to September 2009. The experimental design was a completely randomized block in a 4 x 3 factorial design, composed of four nitrogen levels (0, 60, 120 and 180 kg ha-1) and three potassium levels (0, 90 and 180 kg ha-1) with three replications. The highest yield of commercial bulbs was achieved at an estimated N level of 172.6 kg ha-1. The lowest yield of noncommercial bulbs was estimated at N level of 147.0 kg ha-1. Lower percentage of smaller bulbs (class 2) were obtained by increasing levels of N x K, with a quadratic effect at the dose of 90 kg ha-1 K2O and minimum production point with 127.6 kg N ha-1 (20.3%). Regarding larger caliber bulbs (class 4), linear effects were found both in the absence and for the level of 90 kg ha-1 of K2O as levels of N were increased. When the highest level of 180 kg ha-1 K2O was applied, the level of 92.8 kg ha-1 of N was estimated as the one that would promote the highest bulb yield of this class (35.4%), and 5.3% was found in the lack of potassium fertilization.

Survival analysis: a tool in the study of post-harvest diseases in peaches

Survival analysis is applied when the time until the occurrence of an event is of interest. Such data are routinely collected in plant diseases, although applications of the method are uncommon. The objective of this study was to use two studies on post-harvest diseases of peaches, considering two harvests together and the existence of random effect shared by fruits of a same tree, in order to describe the main techniques in survival analysis. The nonparametric Kaplan-Meier method, the log-rank test and the semi-parametric Cox's proportional hazards model were used to estimate the effect of cultivars and the number of days after full bloom on the survival to the brown rot symptom and the instantaneous risk of expressing it in two consecutive harvests. The joint analysis with baseline effect, varying between harvests, and the confirmation of the tree effect as a grouping factor with random effect were appropriate to interpret the phenomenon (disease) evaluated and can be important tools to replace or complement the conventional analysis, respecting the nature of the variable and the phenomenon.

Pre-harvest cane burning and health: the association between school absences and burning sugarcane fields

The objective of this study was to investigate an association between pre-harvest sugarcane burning and respiratory diseases in children under five years of age. The following data were collected in five schools in the city of Araraquara, SP, Southeastern Brazil, between March and June 2009: daily records of absences and the reasons stated for these absences, total concentration of suspended particulate matter (µg/m3), and air humidity. The relationship between the percentage of school absences due to respiratory problems and the concentration of particulate matter in March and from April to June presented a distinct behavior: absences increased alongside the increase in particulate matter concentration. The use of school absences as indicators of this relationship is an innovative approach.

Projecto de um circuito conversor DC-DC para aplicações de “energy harvest”

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Electrotécnica e de Computadores

Project of a bandgap voltage reference and a temperature sensor for "energy harvest" systems

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e Computadores