876 resultados para Fungi in agriculture
Resumo:
In the present paper, risk-management problems where farmers manage risk both through production decisions and through the use of market-based and informal risk-management mechanisms are considered. It is shown that many of these problems share a common structure, and that a unified and informative treatment of a broad spectrum of risk-management tools is possible within a cost-minimisation framework, under minimal conditions on their objective functions. Fundamental results are derived that apply regardless of the producer's preference towards risks, using only the no-arbitrage condition that agricultural producers never forego any opportunity to lower costs without lowering returns.
Resumo:
During the 24 hour period following inoculation, aggregation of spores and sporelings can have an important effect on the subsequent growth of filamentous fungi in submerged culture. This early phase of growth does not appear to have received much attention, and it was for this reason that the author's research was started. The aggregation, germination and early growth of the filamentous fungus Aspergillus niger have been followed in aerated tower fermenters, by microscopic examination. By studying many individual sporelings it has been possible to estimate the specific growth rate and germination times, and then to assess the branching characteristics of the fungus over a period of from 1 to 10 hours after germination. The results have been incorporated into computer models to simulate the development of the physical structure of individual and aggregated sporelings. Following germination, and an initial rapid growth phase, fungi were found to grow exponentially: in the case of A.niger the mean germination time was about 5 hours and the doubling time was as short as 1.5 hours. Branching also followed an exponential pattern and appeared to be related to hyphal length. Using a simple hypothesis for growth along with empirical parameters, typical fungal structures were generated using the computer models : these compared well with actual sporelings observed under the microscope. Preliminary work suggested that the techniques used in this research could be successfully applied to a range of filamentous fungi.
Resumo:
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Resumo:
The number of fatal accidents in the agricultural, horticultural and forestry industry in Great Britain has declined from an annual rate of about 135 in the 1960's to its current level of about 50. Changes to the size and makeup of the population at risk mean that there has been no real improvement in fatal injury incidence rates for farmers. The Health and Safety Executives' (HSE) current system of accident investigation, recording, and analysis is directed primarily at identifying fault, allocating blame, and punishing wrongdoers. Relatively little information is recorded about the personal and organisational factors that contributed to, or failed to prevent accidents. To develop effective preventive strategies, it is important to establish whether errors by the victims and others, occur at the skills, rules, or knowledge level of functioning: are violations of some rule or procedure; or stem from failures to correctly appraise, or control a hazard. A modified version of the Hale and Glendon accident causation model was used to study 230 fatal accidents. Inspectors' original reports were examined and expert judgement applied to identify and categorise the errors committed by each of the parties involved. The highest proportion of errors that led directly to accidents occurred whilst the victims were operating at the knowledge level. The mix and proportion of errors varied considerably between different classes of victim and kind of accident. Different preventive strategies will be needed to address the problem areas identified.
Resumo:
DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY SERVICES WITH PRIOR ARRANGEMENT
Resumo:
A szerző cikkében a mezőgazdaságban megjelenő kockázatokkal foglalkozik. Vizsgálja, hogy mely tényezők okoznak kockázatot e területen, illetve érinti a kockázat legsúlyosabb következményét, az éhínséget, csökkentésének módjait, valamint a mezőgazdasági biztosítás kérdését. ________ The paper analyzes the different types of risks appearing in agriculture. The paper aims to analyze both the factors that cause the risks and the most serious consequence of these risks, namely famine. The essay also tries to evaluate to possible ways risk can be decreased, especially with the focus on agricultural insurance.
Resumo:
The ecology of the lower marine fungi, namely the thraustochytrides, in the Fladen Ground area (FLEX box) and other parts of the North Sea was studied during 5 cruises in 1975 and 1976. The number of fungi/liter and the number of species showed seasonal fluctuations in the surface water samples from all the stations. A high number was found in September 1976 and a lower number in March 1976. These numbers, however, revealed no seasonal fluctuations in the underlying sediments. In both the surface waters and the sediments, a consistingly low number of fungi was recorded for certain stations and a high number of fungi for others, the reason for this beeing unknown. The sediments revealed a very high number of fungi/liter. Observations on the distribution of various species are presented. Certain species occured more frequently at some stations than at others; certain species occured more in the water column, e.g. Ulkenia minuta, and still others in the sediments, e.g. Thraustochytrium multirudimentale.