972 resultados para American Agriculture Movement.
Resumo:
Development of new agricultural industries in northern Australia is often perceived as a solution to changes in water availability that have occurred within southern Australia as a result of changes to government policy in response to and exacerbated by climate change. This report examines the likely private, social and community costs and benefits associated with the establishment of a cotton industry in the Burdekin. The research undertaken covers three spatial scales by modelling the response of cotton and to climate change at the crop and farm scale and linking this to regional scale modelling of the economy. Modelling crop growth as either a standalone crop or as part of a farm enterprise provides the clearest picture of how yields and water use will be affected under climate change. The alternative to this is to undertake very costly trials in environmental chambers. For this reason it is critical that funding for model development especially for crops being crop in novel environments be seen as a high priority for climate change and adaptation studies. Crop level simulations not only provide information on how the crop responds to climate change, they also illustrate that that these responses are the result of complex interactions and cannot necessarily be derived from the climate information alone. These simulations showed that climate change would lead to decreased cotton yields in 2030 and 2050 without the affect of CO2 fertilisation. Without CO2 fertilisation, yields would be decreased by 3.2% and 17.8%. Including CO2 fertilisation increased yields initially by 5.9%, but these were reduced by 3.6% in 2050. This still represents a major offset and at least ameliorates the impact of climate change on yield. To cope with the decreased in-crop rainfall (4.5% by 2030 and 15.8% in 2050) and an initial increase in evapotranspiration of 2% in 2030 and
Resumo:
Conceptual advances in the field of membrane transport have, in the main, utilized artificial membranes, both planar and vesicular. Systems of biological interest,viz., cells and organelles, resemble vesicles in size and geometry. Methods are, therefore, required to extend the results obtained with planar membranes to liposome systems. In this report we present an analysis of a fluorescence technique, using the divalent cation probe chlortetracycline, in small, unilamellar vesicles, for the study of divalent cation fluxes. An ion carrier (X537 A) and a pore former (alamethicin) have been studied. The rate of rise of fluorescence signal and the transmembrane ion gradient have been related to transmembrane current and potential, respectively. A second power dependence of ion conduction-including the electrically silent portion thereof — on X537 A concentration, has been observed. An exponential dependence of ldquocurrentrdquo on ldquotransmembrane potentialrdquo in the case of alamethicin is also confirmed. Possible errors in the technique are discussed.
Resumo:
Sitting l-r Leo Baeck, Maurice N. Eisendrath, Oscar M. Lazrus; Standing l-r Jane Evans, Henry W. Levy, Saul Elgart, Rabbi Daniel L. Davis, Louis Rittenberg and Leonard H. Spring
Resumo:
An investigation is presented of the daily variation of the maximum cloud zone (MCZ) and the 7W mb trough in the Northern Hemisphere over the Indian longitudes 70–90°E during April–October for 1973–77. It is found that during June–September there are two favorable locations for a MCZ over these longitudes–on a majority of days the MCZ is present in the monsoon zone north of 15°N, and often a secondary MCZ occurs in the equatorial region (0–10°N). The monsoon MCZ gets established by northward movement of the MCZ occurring over the equatorial Indian ocean in April and May. The secondary MCZ appears intermittently, and is characterized by long spells of persistence only when the monsoon MCZ is absent. In each of the seasons studied, the MCZ temporarily disappeared from the mean summer monsoon location (15–28°N) about four weeks after it was established near the beginning of July. It is reestablished by the northward movement of the secondary MCZ, which becomes active during the absence of the monsoon MCZ, in a manner strikingly similar to that observed in the spring to summer transition. A break in monsoon conditions prevails just prior to the temporary disappearance of the monsoon MCZ. Thus we conclude that the monsoon MCZ cannot survive for longer than a month without reestablishment by the secondary MCZ. Possible underlying mechanisms are also discussed.
Resumo:
Movement rates of eastern king prawns, Melicertus plebejus (Hess), were estimated from historical and recent conventional tag-recapture information collected across eastern Australia. Data from three studies and 2,656 tag recaptures were used. Recaptured males and females both moved east–north-east in central Queensland and north–north-east in southern Queensland and New South Wales. Over a period of one year, the estimated transition matrix reflected the species strong northerly movement and the more complex longitudinal movement, showing a very high probability of eastern movement in central Queensland and almost negligible eastern or western movement in northern New South Wales. The high exchange probability between New South Wales and Queensland waters indicated that spatial assessment models with movement rates between state jurisdictions would improve the management of this single-unit stock.
Resumo:
The aim of this thesis is to develop a fully automatic lameness detection system that operates in a milking robot. The instrumentation, measurement software, algorithms for data analysis and a neural network model for lameness detection were developed. Automatic milking has become a common practice in dairy husbandry, and in the year 2006 about 4000 farms worldwide used over 6000 milking robots. There is a worldwide movement with the objective of fully automating every process from feeding to milking. Increase in automation is a consequence of increasing farm sizes, the demand for more efficient production and the growth of labour costs. As the level of automation increases, the time that the cattle keeper uses for monitoring animals often decreases. This has created a need for systems for automatically monitoring the health of farm animals. The popularity of milking robots also offers a new and unique possibility to monitor animals in a single confined space up to four times daily. Lameness is a crucial welfare issue in the modern dairy industry. Limb disorders cause serious welfare, health and economic problems especially in loose housing of cattle. Lameness causes losses in milk production and leads to early culling of animals. These costs could be reduced with early identification and treatment. At present, only a few methods for automatically detecting lameness have been developed, and the most common methods used for lameness detection and assessment are various visual locomotion scoring systems. The problem with locomotion scoring is that it needs experience to be conducted properly, it is labour intensive as an on-farm method and the results are subjective. A four balance system for measuring the leg load distribution of dairy cows during milking in order to detect lameness was developed and set up in the University of Helsinki Research farm Suitia. The leg weights of 73 cows were successfully recorded during almost 10,000 robotic milkings over a period of 5 months. The cows were locomotion scored weekly, and the lame cows were inspected clinically for hoof lesions. Unsuccessful measurements, caused by cows standing outside the balances, were removed from the data with a special algorithm, and the mean leg loads and the number of kicks during milking was calculated. In order to develop an expert system to automatically detect lameness cases, a model was needed. A probabilistic neural network (PNN) classifier model was chosen for the task. The data was divided in two parts and 5,074 measurements from 37 cows were used to train the model. The operation of the model was evaluated for its ability to detect lameness in the validating dataset, which had 4,868 measurements from 36 cows. The model was able to classify 96% of the measurements correctly as sound or lame cows, and 100% of the lameness cases in the validation data were identified. The number of measurements causing false alarms was 1.1%. The developed model has the potential to be used for on-farm decision support and can be used in a real-time lameness monitoring system.
Resumo:
Temporal and spatial patterns in parasite assemblages were examined to evaluate the degree of movement and connectivity of post-recruitment life-history stages of a large, non-diadromous tropical estuarine teleost, king threadfin Polydactylus macrochir, collected from 18 locations across northern Australia. Ten parasites types (juvenile stages of two nematodes and seven cestodes, and adults of an acanthocephalan) were deemed to be suitable for use as biological tags, in that they were considered to have a long residence time in the fish, were relatively easy to find and were morphologically very different to each other which aided discrimination. Univariate and discriminant function analysis of these parasites revealed little difference in temporal replicates collected from five locations, suggesting that the parasite communities were stable over the timeframes explored. Univariate, discriminant function, and BrayCurtis similarity analyses indicated significant spatial heterogeneity, with BrayCurtis classification accuracies ranging from 55 to 100% for locations in north-western and northern Australia, 24 to 88% in the Gulf of Carpentaria, and 39 to 88% on the east coast of Queensland. Few differences were observed among locations separated by <200 km. The observed patterns of parasite infection are in agreement with concurrent studies of movement and connectivity of P. macrochir in that they indicate a complex population structure across northern Australia. These results should be considered when reviewing the management arrangements for this species.
Resumo:
The potato virus A (PVA) genome linked protein (VPg) is a multifunctional protein that takes part in vital infection cycle events such as replication and movement of the virus from cell to cell. VPg is attached to the 5´ end of the genome and is carried in the tip structure of the filamentous virus particle. VPg is also the last protein to be cleaved from the polyprotein. VPg interacts with several viral and host proteins and is phosphorylated at several positions. These features indicate a central role in virus epidemiology and a requirement for an efficient but flexible mechanism for switching between different functions. -- This study examines some of the key VPg functions in more detail. Mutations in the positively charged region from Ala38 to Lys44 affected the NTP binding, uridylylation, and in vitro translation inhibition activities of VPg, whereas in vivo translation inhibition was not affected. Some of the data generated in this study implicated the structural flexibility of the protein in functional activities. VPg lacks a rigid structure, which could allow it to adapt conformationally to different functions as needed. A major finding of this study is that PVA VPg belongs to the class of ´intrinsically disordered proteins´ (IDPs). IDPs are a novel protein class that has helped to explain the observed lack of structure. The existence of IDPs clearly shows that proteins can be functional and adapt a native fold without a rigid structure. Evidence for the intrinsic disorder of VPg was provided by CD spectroscopy, NMR, fluorescence spectroscopy, bioinformatic analysis, and limited proteolytic digestion. The structure of VPg resembles that of a molten globule-type protein and has a hydrophobic core domain. Approximately 50% of the protein is disordered and an α-helical stabilization of these regions has been hypothesized. Surprisingly, VPg structure was stabilized in the presence of anionic lipid vesicles. The stabilization was accompanied by a change in VPg structure and major morphological modifications of the vesicles, including a pronounced increase in the size and appearance of pore or plaque like formations on the vesicle surface. The most likely scenario seems to be an α-helical stabilization of VPg which induces formation of a pore or channel-like structure on the vesicle surface. The size increase is probably due to fusion or swelling of the vesicles. The latter hypothesis is supported by the evident disruption of the vesicles after prolonged incubation with VPg. A model describing the results is presented and discussed in relation to other known properties of the protein.
Resumo:
Photograph contained within portfolio including title page and signatures
Resumo:
Movement rates of eastern king prawns, Melicertus plebejus (Hess), were estimated from historical and recent conventional tag-recapture information collected across eastern Australia. Data from three studies and 2,656 tag recaptures were used. Recaptured males and females both moved east-north-east in central Queensland and north-north-east in southern Queensland and New South Wales. Over a period of one year, the estimated transition matrix reflected the species strong northerly movement and the more complex longitudinal movement, showing a very high probability of eastern movement in central Queensland and almost negligible eastern or western movement in northern New South Wales. The high exchange probability between New South Wales and Queensland waters indicated that spatial assessment models with movement rates between state jurisdictions would improve the management of this single-unit stock.
Resumo:
The objective was to measure productivity growth and its components in Finnish agriculture, especially in dairy farming. The objective was also to compare different methods and models - both parametric (stochastic frontier analysis) and non-parametric (data envelopment analysis) - in estimating the components of productivity growth and the sensitivity of results with respect to different approaches. The parametric approach was also applied in the investigation of various aspects of heterogeneity. A common feature of the first three of five articles is that they concentrate empirically on technical change, technical efficiency change and the scale effect, mainly on the basis of the decompositions of Malmquist productivity index. The last two articles explore an intermediate route between the Fisher and Malmquist productivity indices and develop a detailed but meaningful decomposition for the Fisher index, including also empirical applications. Distance functions play a central role in the decomposition of Malmquist and Fisher productivity indices. Three panel data sets from 1990s have been applied in the study. The common feature of all data used is that they cover the periods before and after Finnish EU accession. Another common feature is that the analysis mainly concentrates on dairy farms or their roughage production systems. Productivity growth on Finnish dairy farms was relatively slow in the 1990s: approximately one percent per year, independent of the method used. Despite considerable annual variation, productivity growth seems to have accelerated towards the end of the period. There was a slowdown in the mid-1990s at the time of EU accession. No clear immediate effects of EU accession with respect to technical efficiency could be observed. Technical change has been the main contributor to productivity growth on dairy farms. However, average technical efficiency often showed a declining trend, meaning that the deviations from the best practice frontier are increasing over time. This suggests different paths of adjustment at the farm level. However, different methods to some extent provide different results, especially for the sub-components of productivity growth. In most analyses on dairy farms the scale effect on productivity growth was minor. A positive scale effect would be important for improving the competitiveness of Finnish agriculture through increasing farm size. This small effect may also be related to the structure of agriculture and to the allocation of investments to specific groups of farms during the research period. The result may also indicate that the utilization of scale economies faces special constraints in Finnish conditions. However, the analysis of a sample of all types of farms suggested a more considerable scale effect than the analysis on dairy farms.
Resumo:
Page 24 of the "American Jewish Cavalcade" scrapbook of Leo Baeck in New York found in ROS 10 Folder 3
Resumo:
Page 24 of the "American Jewish Cavalcade" scrapbook of Leo Baeck in New York found in ROS 10 Folder 3
Resumo:
Page 23 of the "American Jewish Cavalcade" scrapbook of Leo Baeck in New York found in ROS 10 Folder 3
Resumo:
Page 12 of the "American Jewish Cavalcade" scrapbook of Leo Baeck in New York found in ROS 10 Folder 3