Botulism (limberneck) in poultry

"March, 1959

Regenerative Power Optimal Reaction Wheel Attitude Control

The thesis work develops an instantaneous power optimal attitude control for a spacecraft utilizing an integrated reaction wheel - flywheel system allowing for energy storage and return. The control is generally formulated to utilize an arbitrarily large number of reaction wheels, and is applicable to any system with redundant wheels spanning three-dimensional space. This is accomplished by manipulation of the wheel torque null motion such that the resulting attitude dynamics are not affected. By application of physical constraints on the wheel motor performance, the solution method to find the null torques is reduced to a hyperdimensional vector geometry problem, and the proper control torques are uniquely determined. The resulting power optimal control guarantees that the instantaneous maximum power is returned from the reaction wheels at all times. This control is then applied to a variety of control laws, demonstrating its behavior for a variety of control applications and initial spacecraft states. These include a velocity regulator control and attitude a velocity tracking control. Comparison to other relevant reaction wheel controls demonstrates the analytically developed instantaneous power optimal and minimum energy state seeking behavior. Finally, future developments are suggested, including the incorporation of wheel power return inefficiency and application of the developed methodology for integrated energy storage and power tracking

Prevalence and risk factors for bovine leptospirosis in Mato Grosso do Sul, Brazil

Foi investigada a prevalência de anticorpos antileptospira em fêmeas bovinas com idade igual ou superior a 24 meses, provenientes de 178 rebanhos de 22 municípios do estado de Mato Grosso do Sul, bem como identificados fatores de risco associados à infecção. Foram analisadas 2.573 amostras de soro sangüíneo por meio do teste de soroaglutinação microscópica perante 10 sorovares de leptospira. Títulos iguais ou superiores a 100 para um ou mais sorovares foram detectados em 1.801 fêmeas (98,8%) de 161 (96,5%) rebanhos. O sorovar Hardjo (65,6%) foi apontado como o mais provável, seguido do sorovar Wolffi (12,3%). Os resultados demonstram que a leptospirose bovina se encontra presente em todos os municípios estudados, com alta prevalência, tanto em animais como em rebanhos. Os fatores de risco identificados neste estudo e associados à infecção por bactérias do gênero lepstopira foram o tipo de exploração pecuária de corte e a raça Zebu. _____________________________________________________________________________________________________________ ABSTRACTThe prevalence of anti-Leptospira spp. antibodies was estimated for female cattle aged 24 months or older. The sample comprised 178 herds from 22 counties in the state of Mato Grosso do Sul, Brazil. The risk factors associated with the presence of infeccion were investigated. A total of 2,573 blood serum samples were tested against 10 leptospira serovars using the microagglutination test (MAT). Titers of 100 or higher for one or more serovars were detected in 1,801 females (98.8%) from 161 herds (96.5%). Serovar Hardjo (65.6%) was the most frequent, followed by serovar Wolffi (12.3%). These results suggest that bovine leptospirosis is widespread in all the counties under study, with a high prevalence both at the animal and the herd level. Beef farms and the Zebu breed were associated to the higher risk of herd infection by leptospiras

Applications of Laboratory Technology in the Evaluation of the Risk of Rabies Transmissions by Biting Dogs and Cats

While rabies is not a common disease in domestic animal species of the United States, potential exposures to rabies in the form of bites are very common and increasing. A nationwide study conducted among general hospitals shows that 1 percent of emergency room visits are for animal bites, of which 80-90 percent are inflicted by the dog (Callaham 1980). This figure is conservative, as the study did not include pediatric hospitals, the bite of victims that progress only to a physician\u27s office, or those that receive no medical care at all. In Missouri alone, this study would infer about 1500 dog bites per year reaching only the general hospital. The number of dog and other animal bites across the country is unknown but may safely be assumed to be staggering in magnitude

Rehabilitation transition program to improve community participation among stroke survivors: A randomized clinical trial

IMPORTANCE: Interventions are needed to support the long-term needs of stroke survivors when they transition from inpatient rehabilitation to home, where they face new home and community environmental barriers. OBJECTIVE: To compare the efficacy of a novel, enhanced rehabilitation transition program with attentional control to improve community participation and activity of daily living (ADL) performance and to reduce environmental barriers in the home and community after stroke. DESIGN, SETTING, AND PARTICIPANTS: This phase 2b, parallel randomized clinical trial assessed patients 50 years or older who had experienced an acute ischemic stroke or intracerebral hemorrhage, were independent in ADLs before stroke, and planned to be discharged home. Patients were assessed at an inpatient rehabilitation facility in St Louis, Missouri, and their homes from January 9, 2018, to December 20, 2023. INTERVENTION: Community Participation Transition after Stroke (COMPASS), including home modifications and strategy training. MAIN OUTCOMES AND MEASURES: The primary outcome was community participation (Reintegration to Normal Living Index). Secondary outcomes were daily activity performance (Stroke Impact Scale ADL domain and the In-Home Occupational Performance Evaluation [I-HOPE] activity, performance, and satisfaction scores) and environmental barriers in the home (I-HOPE environmental barriers score). RESULTS: A total of 185 participants (mean [SD] age, 66.3 [9.0] years; 105 [56.8%] male) were randomized (85 to the COMPASS group and 100 to the control group). The COMPASS and control participants experienced similar improvements in community participation by 12 months, with no significant group (mean difference, 0.3; 95% CI, -4.6 to 5.2; P = .91) or group × time interaction (between-group differences in changes over time, 1.3; 95% CI, -7.1 to 9.6; P = .76) effects. Improvements in I-HOPE performance and satisfaction scores were greater for COMPASS participants than control participants at 12 months (between-group differences in changes for performance: 0.39; 95% CI, 0.01-0.77; P = .046; satisfaction: 0.52; 95% CI, 0.08-0.96; P = .02). The COMPASS participants had greater improvements for I-HOPE environmental barriers than the control participants (P = .003 for interaction), with the largest differences at 6 months (between-group differences in changes: -15.3; 95% CI -24.4 to -6.2). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial of stroke survivors, participants in both groups experienced improvements in community participation. COMPASS participants had greater improvements in self-rated performance and satisfaction with performing daily activities as well as a greater reduction in environmental barriers than control participants. COMPASS reduced environmental barriers and improved performance of daily activities for stroke survivors as they transitioned from inpatient rehabilitation to home. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03485820

Listeria pathogenesis and molecular virulence determinants

The gram-positive bacterium Listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. Pregnant women, neonates, the elderly, and debilitated or immunocompromised patients in general are predominantly affected, although the disease can also develop in normal individuals. Clinical manifestations of invasive listeriosis are usually severe and include abortion, sepsis, and meningoencephalitis. Listeriosis can also manifest as a febrile gastroenteritis syndrome. In addition to humans, L. monocytogenes affects many vertebrate species, including birds. Listeria ivanovii, a second pathogenic species of the genus, is specific for ruminants. Our current view of the pathophysiology of listeriosis derives largely from studies with the mouse infection model. Pathogenic listeriae enter the host primarily through the intestine. The liver is thought to be their first target organ after intestinal translocation. In the liver, listeriae actively multiply until the infection is controlled by a cell-mediated immune response. This initial, subclinical step of listeriosis is thought to be common due to the frequent presence of pathogenic L. monocytogenes in food. In normal indivuals, the continual exposure to listerial antigens probably contributes to the maintenance of anti-Listeria memory T cells. However, in debilitated and immunocompromised patients, the unrestricted proliferation of listeriae in the liver may result in prolonged low-level bacteremia, leading to invasion of the preferred secondary target organs (the brain and the gravid uterus) and to overt clinical disease. L. monocytogenes and L. ivanovii are facultative intracellular parasites able to survive in macrophages and to invade a variety of normally nonphagocytic cells, such as epithelial cells, hepatocytes, and endothelial cells. In all these cell types, pathogenic listeriae go through an intracellular life cycle involving early escape from the phagocytic vacuole, rapid intracytoplasmic multiplication, bacterially induced actin-based motility, and direct spread to neighboring cells, in which they reinitiate the cycle. In this way, listeriae disseminate in host tissues sheltered from the humoral arm of the immune system. Over the last 15 years, a number of virulence factors involved in key steps of this intracellular life cycle have been identified. This review describes in detail the molecular determinants of Listeria virulence and their mechanism of action and summarizes the current knowledge on the pathophysiology of listeriosis and the cell biology and host cell responses to Listeria infection. This article provides an updated perspective of the development of our understanding of Listeria pathogenesis from the first molecular genetic analyses of virulence mechanisms reported in 1985 until the start of the genomic era of Listeria research