4,341 research outputs found
Consideration of Interference Correlation Properties in a JD-CDMA Mobile Radio System with Coherent Receiver Antenna Diversity
No full textIn code division multiple access (CDMA) mobile radio systems, both intersymbol interference and multiple access interference arise which can be combatted by using Joint Detection (JD) techniques, to reduce the degradation in performance resulting from time variance, coherent receiver antenna diversity (CRAD) can be used. The application of JD techniques offers the possibility to exploit the knowledge of noise covariances at the receiver. If only intercell (cochannel) interference is considered, the noise covariances in the uplink receiver of a multiple receiver antenna CDMA mobile radio system depend mainly on the directions of arrival (DOAs) of the interfering signals and the receiver antenna placement. Therefore, if the interferer DOAs are known at the base station, these covariances could be estimated. In this thesis, a realistic model of the uplink of a JD CDMA mobile radio system with CRAD is described in which the above mentioned interference cancelling method is used. Simulation results according to this model are given and evaluated.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Dairy farmers’ perceptions toward the implementation of on-farm Johne’s disease prevention and control strategies
No full textmplementation of specific management strategies on dairy farms is currently the most effective way to reduce the prevalence of Johne’s disease (JD), an infectious chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). However, dairy farmers often fail to implement recommended strategies. The objective of this study was to assess perceptions of farmers participating in a JD prevention and control program toward recommended practices, and explore factors that influence whether or not a farmer adopts risk-reducing measures for MAP transmission. Semi-structured interviews were conducted with 25 dairy farmers enrolled in a voluntary JD control program in Alberta, Canada. Principles of classical grounded theory were used for participant selection, interviewing, and data analysis. Additionally, demographic data and MAP infection status were collected and analyzed using quantitative questionnaires and the JD control program database. Farmers’ perceptions were distinguished according to 2 main categories: first, their belief in the importance of JD, and second, their belief in recommended JD prevention and control strategies. Based on these categories, farmers were classified into 4 groups: proactivists, disillusionists, deniers, and unconcerned. The first 2 groups believed in the importance of JD, and proactivists and unconcerned believed in proposed JD prevention and control measures. Groups that regarded JD as important had better knowledge about best strategies to reduce MAP transmission and had more JD risk assessments conducted on their farm. Although not quantified, it also appeared that these groups had more JD prevention and control practices in place. However, often JD was not perceived as a problem in the herd and generally farmers did not regard JD control as a “hot topic” in communications with their herd veterinarian and other farmers. Recommendations regarding how to communicate with farmers and motivate various groups of farmers according to their specific perceptions were provided to optimize adoption of JD prevention and control measures and thereby increase success of voluntary JD control programs
Agronomic performance and selection of soybean genotypes in the municipality of Uberlândia - MG
No full textCNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoTrabalho de Conclusão de Curso (Graduação)O processo de seleção de genótipos superiores é uma das principais etapas de um programa de melhoramento genético de plantas. Para isso, é necessário avaliar o desempenho das progênies em relação às características agronômicas com a finalidade de se obter os parâmetros genéticos úteis no processo seletivo. Objetivou-se neste trabalho avaliar caracteres agronômicos, estimar parâmetros genéticos e selecionar linhagens de soja em Uberlândia-MG. Avaliaram-se 27 linhagens desenvolvidas pelo Programa de Melhoramento de Soja da Universidade Federal de Uberlândia e 1 cultivar (BRS GO 7560) em delineamento de blocos completos casualisados com três repetições, nos quais foram estudados oito caracteres: Número de dias para o florescimento e maturidade (NDF e NDM), altura da planta no florescimento e na maturidade (APF e APM), número de nós na haste principal no florescimento e na maturidade (NNF e NNM), número de vagens (NV) e produção de grãos (PROD). Procedeu-se a análise de variância, teste de média de Scott-Knott e análise dos ganhos genéticos para seleção. Houve variabilidade para todos os caracteres ao nível de 1% de probabilidade pelo teste F. Os maiores ganhos genéticos para seleção direta foram obtidos para os caracteres NV (27,32%), PROD (25,17%) e APM (21,30%). Os genótipos UFUS JD 20, UFUS JD 22 e UFUS JD 25 foram selecionados quanto à produtividade de grãos e a linhagem UFUS JD 19 foi a única selecionada para cinco dos oito caracteres analisados indicando que é o genótipo com mais alto potencial para o mercado
Canto de amor e liberdade em ABC de Castro Alves
No full textUniversidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Biociências Letras e Ciências Exatas de São José do Rio Preto, Sao Jose do Rio Preto, Rua Cristóvão Colombo, 2265, Jd. Nazareth, CEP 15054000, SP, BrasilUniversidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Biociências Letras e Ciências Exatas de São José do Rio Preto, Sao Jose do Rio Preto, Rua Cristóvão Colombo, 2265, Jd. Nazareth, CEP 15054000, SP, Brasi
Knowledge gaps that hamper prevention and control of Mycobacterium avium subspecies paratuberculosis infection
No full textIn the last decades, many regional and country‐wide control programmes for Johne's disease (JD ) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within‐farm and farm‐to‐farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps
Evaluation of an alternative method of herd classification for infection with paratuberculosis in cattle herds in the United States
No full textObjective - To develop a better system for classification of herd infection status for paratuberculosis (Johne's disease JD]) in US cattle herds on the basis of the risk of potential transmission of Mycobacterium avium subsp paratubeculosis. Sample - Simulated data for herd size and within-herd prevalence; sensitivity and specificity for test methods obtained from consensus-based estimates. Procedures - Interrelationships among variables influencing interpretation and classification of herd infection status for JD were evaluated by use of simulated data for various herd sizes, true within-herd prevalences, and sampling and testing methods. The probability of finding ≥1 infected animal in herds was estimated for various testing methods and sample sizes by use of hypergeometric random sampling. Results - 2 main components were required for the new herd JD classification system: the probability of detection of infection determined on the basis of test results from a sample of animals and the maximum detected number of animals with positive test results. Tables were constructed of the estimated probability of detection of infection, and the maximum number of cattle with positive test results or fecal pools with positive culture results with 95% confidence for classification of herd JD infection status were plotted. Herd risk for JD was categorized on the basis of 95% confidence that the true within-herd prevalence was ≤15%, ≤10%, ≤5%, or ≤2%. Conclusions and Clinical Relevance - Analysis of the findings indicated that a scientifically rigorous and transparent herd classification system for JD in cattle is feasible.Source type: Electronic(1
Factors associated with participation of Alberta dairy farmers in a voluntary, management-based Johne’s disease control program
No full textThe Alberta Johne's Disease Initiative (AJDI) is a voluntary, management-based prevention and control program for Johne's disease (JD), a wasting disease in ruminants that causes substantial economic losses to the cattle industry. Despite extensive communication about the program's benefits and low cost to participating producers, approximately 35% of Alberta dairy farmers have not enrolled in the AJDI. Therefore, the objective was to identify differences between AJDI nonparticipants and participants that may influence enrollment. Standardized questionnaires were conducted in person on 163 farms not participating and 61 farms participating in the AJDI. Data collected included demographic characteristics, internal factors (e.g., attitudes and beliefs of the farmer toward JD and the AJDI), external factors (e.g., farmers' JD knowledge and on-farm goals and constraints), as well as farmers' use and influence of various information sources. Nonparticipants and participants differed in at least some aspects of all studied categories. Based on logistic regression, participating farms had larger herds, higher self-assessed knowledge of JD, better understanding of AJDI details before participation, and used their veterinarian more often to get information about new management practices and technologies when compared with nonparticipants. In contrast, nonparticipants indicated that time was a major on-farm constraint and that participation in the AJDI would take too much time. They also indicated that they preferred to wait and see how the program worked on other farms before they participated
Deadly meals: The influence of personal and job factors on burnout and risky riding behaviours of food delivery motorcyclists
No full textFood delivery riders are overrepresented in road crashes. Arguably, the increased risk experienced by food delivery riders is linked to the working conditions offered by the “gig economy”. Research is needed to fully understand the safety-related issues this vulnerable group of road users face daily and identify opportunities for counter measures. In this investigation, we proposed a new theoretical model to explain the risky behaviour of food delivery motorcyclists based on the well-established Job Demands-Resources (JD-R) model. Following the JD-R, we considered the impact of job demands (job aspects that require sustained effort) and job resources (job aspects that help achieve work-related goals, reduce job demands and stimulate personal development) on the risky riding behaviours of food delivery motorcyclists. The JD-R model was also extended with three constructs, including personal demands, personal resources, and perceived safety risk to explore the role of individuals' within-person aspects. The developed model was tested using data collected from 554 food delivery riders in the two biggest cities in Vietnam. The results showed that job burnout, job resources, and personal demands directly impact risky riding behaviours, in which job burnout was the most significant predictor. Constructs such as job demands, personal resources, and perceived safety risk were not significant predictors of risky riding behaviours. This research shows that organisation-level factors could be modified to prevent risky riding behaviour. The gig economy industry can do much more to improve the safety of delivery riders.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Safety and Security Scienc
Análise espaço temporal dos componentes do balanço de radiação, energia e evapotranspiração, usando técnicas de sensoriamento remoto em áreas irrigadas do projeto Jaíba/MG
No full textThe present search aims to analyze the components of radiation balance, energy balance and evapotranspiration in irrigated areas of Jaíba Project and surrounding areas. The study area is located in the North of Minas Gerais, in the municipalities of Jaíba and Matias Cardoso, in the right bank of São Francisco River and left bank of Verde Grande River, in zone 23, between the UTM coordinates of 595.204 and 626.309 mE and 8.308.401 and 8.341.257 mN. It were used five images of the Landsat 5 satellite, TM sensor, orbit 219 point 70, obtained in the days January 31st (JD 31), April 21st (JD 111), June 24th (JD 175), July 10th (JD 191) and September 12th (JD 255) in the year of 2011. The components estimate of radiation balance, energy balance and daily evapotranspiration were obtained through the SEBAL algorithm (Surface Energy Balance Algorithm for Land). The SEBAL is constituted of many steps, which include radiometric calibration, computation of reflectance, surface albedo, vegetation indices (NDVI, SAVI, LAI), emissivity, surface temperature, net radiation flux, soil heat flux (G), sensible heat flux (H), latent heat flux (λET) and evapotranspiration. For obtainment of those parameters, it was used data from meteorological station located within the Landsat scene. It were obtained average values of surface albedo in the order of 15%, 17%, 17%, 18% e 21% in irrigated areas in the days JD 31, JD 111, JD 175, JD 191 and JD 255, respectively; average values of net radiation flux in the order of 689,03 W/m-2, 592,51 W/m-2, 447,28 W/m-2, 445,28 W/m-2 and 562,87 W/m-2 for the days JD 31, JD 111, JD 175, JD 191 and JD 255 respectively; and average values for 24-hour evapotranspiration of 6,85 mm.day-1, 4,0 mm.day-1, 2,6 mm.day-1, 2,2 mm.day-1 and 3,4 mm.day-1 for the days JD 31, JD 111, JD 175, JD 191 and JD 255 respectively. It was observed that the components of radiation balance, energy balance and evapotranspiration presented variation in the analyzed period due to the quantity of available radiation for each day and deciduousness of deciduous seasonal forest. The technique used has demonstrated to be efficient in analyzes of the components studied, being the SEBAL an important tool for environmental analyzes and water resources management.Fundação de Amparo a Pesquisa do Estado de Minas GeraisMestre em GeografiaA presente pesquisa teve como objetivo a análise dos componentes do balanço de
radiação, balanço de energia e evapotranspiração em áreas irrigadas do projeto Jaíba e
áreas circunvizinhas. A área de estudo esta localizada no norte de Minas Gerias, nos
Municípios de Jaíba e Matias Cardoso na margem direita do rio São Francisco e
esquerda do Verde Grande na zona 23, entre as coordenadas UTM 595204 e 626309 mE
e 8308401 e 8341257 mN. Foram utilizados cinco imagens do Landsat 5 sensor TM
órbita 219 ponto 70, obtidas nos dias 31 de janeiro (DJ 31), 21 de abril (DJ 111), 24 de
junho (DJ 175), 10 de julho (DJ 191) e 12 de setembro (DJ 255) do ano de 2011. A
estimativa dos componentes do balanço de radiação, balanço de energia e
evapotranspiração diária foram obtidos através do algoritmo SEBAL (Surface Energy
Balance Algorithm for Land). O SEBAL é constituído de várias etapas, que incluem
calibração radiométrica, cômputo da reflectividade, albedo de superfície, índices de
vegetação (NDVI, SAVI, IAF), emissividade, temperatura de superfície, saldo de
radiação, fluxo de calor no solo (G), fluxo de calor sensível (H), fluxo de calor latente
(LE) e evapotranspiração. Para a obtenção desses parâmetros utilizou-se dados da
estação meteorológica localizada no interior da cena Landsat. Foram obtidos valores
médios de albedo de superfície na ordem de 15%, 17%, 17%, 18% e 21% em áreas
irrigadas nos dias DJ 31, DJ 111, DJ 175, DJ 191 e DJ 255 respectivamente. Valores
médios de saldo de radiação na ordem de 689,03 2 Wm , 592,51 2 Wm , 447,28 2 Wm ,
445,28 2 Wm e 562,87 2 Wm para os dias DJ 31, DJ 111, DJ 175, DJ 191 e DJ 255
respectivamente. E valores médios para a evapotranspiração no período de 24 horas de
6,85 mm.dia-1, 4,0 mm.dia-1, 2,6 mm.dia-1, 2,2 mm.dia-1 e 3,4 mm.dia-1 para os dias DJ
31, DJ 111, DJ 175, DJ 191 e DJ 255 respectivamente. Observou-se que os
componentes do balanço de radiação, balanço de energia e evapotranspiração
apresentaram variação no período analisado devido à quantidade de radiação disponível
para cada dia e deciduidade das áreas de floresta estacional decidual. A técnica utilizada
demonstrou-se eficiente nas análises dos componentes estudados, sendo o SEBAL uma
ferramenta importante para as análises ambientais e gestão dos recursos hídricos
Dairy producer satisfaction and knowledge transfer with the veterinary-administered risk assessment and management plan in a voluntary Johne's disease control program
No full textThe Atlantic Johne's Disease Initiative (AJDI) aims to control Mycobacterium avium ssp. paratuberculosis infection by using veterinary-administered risk assessments to identify high-risk management practices and prompt changes in management behavior. Objectives for this study were to measure producer satisfaction with the veterinary-administered risk assessment and management plan (RAMP) process in a voluntary Johne's disease (JD) control program, compare RAMP-specific satisfaction results based on herd JD status, and measure knowledge transfer from certified veterinarians to producers during the RAMP. A satisfaction questionnaire was adapted to the RAMP process in the AJDI to measure producer satisfaction. The questionnaire included 9 RAMP-specific producer satisfaction items, 1 global RAMP satisfaction item, and 16 questions to assess producer knowledge and knowledge translation about JD, bovine viral diarrhea (BVD), and bovine leukosis virus (BLV) during the RAMP (BVD and BLV used for comparison purposes). A total of 133 dairy producers in the AJDI (79.6% response rate) completed the questionnaire by telephone. The RAMP-specific satisfaction was high among the AJDI producers surveyed, and these results were not found to differ based on herd JD status. The lowest satisfaction scores and the highest number of “unable to assess” responses were for the item relating to cost. Factors that contributed to RAMP-specific producer satisfaction were not identified from the demographic and herd information available in this study. The knowledge scores indicated moderate knowledge about JD and fair knowledge about BVD and BLV. Evidence of knowledge translation from the RAMP was mixed in this study. Bovine viral diarrhea knowledge scores were not found to differ based on whether or not the certified veterinarian discussed BVD during the preceding RAMP, but BLV knowledge scores were higher among dairy producers that discussed BLV during the preceding RAMP. Strengths and gaps in producer knowledge about these 3 infectious diseases were identified. By using this producer questionnaire, interventions aimed at improving the content, delivery, and satisfaction of RAMP in JD control programs, such as the AJDI, can be developed.Dairy Farmers of Prince Edward Island, Nova Scotia, New Brunswick, and Newfoundland and LabradorAgriculture and Agri-Foo
- …
