Epidemiologic aspects of infectious agents involved in reproductive inefficiency in swine

First litter gilts (N = 210) in 15 herds were monitored through their first gestation. Prevalence of 6 infectious agents associated with reproductive failure was estimated in the sow and finisher populations in each herd. The association between reproductive failure and infection, as determined by a ≥4-fold increase in antibody titer, was determined. Farrowing ≥3 stillborn pigs, farrowing ≥3 mummified fetuses, and farrowing ≤6 live pigs were statistically associated with seroconversion to infectious agents;The sensitivity, specificity, and diagnostic titer of the microtiter serum neutralization test (SN) for the diagnosis of encephalomycarditis virus was determined. Antibody titers up to 1:8 were observed in uninfected animals and ranged from 1:5.7 to 1:1024 in infected animals. SN antibody titers of 1:8 were highly suggestive of infection, with an estimated 97.8 % sensitivity and 95.7 % specificity at this dilution. Antibody titers of 1:16 or greater were conclusive for EMCV infection, based on a test specificity of 100% at these dilutions;A total of 2614 animals from 104 herds located throughout the state of Iowa were tested for antibodies against EMCV. A difference (P \u3c 0.002) was observed between the prevalence in sows and gilts (17.2%) vs. finishing animals (12.2%). Breeding swine in total confinement (20.5%) showed a higher prevalence (P = 0.04) than breeders in other types of housing (12.1%), while the prevalence in finishing animals raised in total confinement (6.4%) was lower (P = 0.02) than finishers not raised in total confinement (13.6%). No association was detected between prevalence and herd size, or prevalence and season of the year. The true prevalence of EMCV in Iowa swine was estimated to be 13.8% in breeding stock and 8.5% in finishing animals. On a herd basis, 89.4% (93/104) of the herds had one or more EMCV-positive animals. These animals were also tested against for antibodies against Toxoplasma gondii by ELISA. The true prevalence of toxoplasmosis was estimated as 5.4% among finishing swine and 11.4% among sows and gilts. Herds with fewer than 100 breeders were more likely to be infected than herds with 100 or more breeders (P \u3c 0.05). Seropositivity in breeding stock was approximately the same in infected herds, regardless of herd size. Herds with finishers in total confinement were as likely to become infected as herds with other types of facilities, but infected herds with finishers in confinement appeared to have a lower in-herd prevalence than herds with other types of facilities (P = 0.09). No seasonal effects were observed and prevalence remained relatively constant throughout the year

The Impact of Supervisor-Subordinate Exchange on State Government Employees

Interactions such as task assignments and communications between supervisors and subordinates have unintended negative consequences on subordinates such as alienation of subordinates that are not members of the \u27in\u27 group. These relations are determined by the quality of the leader-member exchange (LMX) between supervisor and subordinate. The purpose of this study was to examine the impact of supervisor-subordinate exchange on state government employees by understanding the essence of these exchanges in state government agencies. The theoretical foundation of this phenomenological study was Graen and Uhl-Bien\u27s conceptualization of LMX. Data were collected through 12 semi structured interviews with subordinates from the North Carolina Motor Vehicle Driver\u27s License Section. This group of employees from the NC DMV were selected because of the geographical convenience to conduct interviews with participants. Supervisors were not interviewed for this study because the focus was the perceived effect on the employees\u27 performance, motivation, and attitudes. The data were coded and analyzed using a modified Stevick-Colaizzi-Keen method. The results of this study supported that supervisor-subordinate exchanges can influence subsequent behaviors in government employees. This study may have future policy implications in that the results can be used to influence new policy or revise current policies concerning supervisor training within local, state, and federal government agencies. Organizations that comprehend how and why supervisor-subordinate exchanges impact them can revise training for both management and employees, improve communication and relationship skills, and reduce negative effects from these exchanges to promote positive social change

The space station assembly phase: Flight telerobotic servicer feasibility, volume 1

The question is addressed which was raised by the Critical Evaluation Task Force (CETF) analysis of the space station: if a Flight Telerobotic Servicer (FTS) of a given technical risk could be built for use during space station assembly, could it save significant extravehicular (EVA) resources. Key issues and trade-offs associated with using an FTS to aid in space station assembly phase tasks such as construction and servicing are identified. A methodology is presented that incorporates assessment of candidate assembly phase tasks, telerobotics performance capabilities, development costs, operational constraints (STS and proximity operations), maintenance, attached payloads, and polar platforms. A discussion of the issues is presented with focus on potential FTS roles: (1) as a research-oriented test bed to learn more about space usage of telerobotics; (2) as a research-based test bed with an experimental demonstration orientation and limited assembly and servicing applications; or (3) as an operational system to augment EVA, to aid the construction of the space station, and to reduce the programmatic (schedule) risk by increasing the flexibility of mission operations. During the course of the study, the baseline configuration was modified into Phase 1 (a station assembled in 12 flights), and Phase 2 (a station assembled over a 30 flight period) configuration

TOXOPLASMA GONDII IN U.S. SWINE OPERATIONS: AN ASSESSMENT OF MANAGEMENT FACTORS

Sera from hogs were analyzed using the modified direct agglutination test (MAT). Serum samples were collected from sows which were part of the National Animal Health Monitoring System (NAHMS) swine survey. The blood sera on file represented 394 randomly selected hog farms throughout the United States. Additionally, the NAHMS survey included information on type of production facilities and level of cat, dog, or bird access to the facilities. Of the sows tested 19 percent tested positive for toxoplasmosis. This study showed a positive relationship between sows or herds testing positive for Toxoplasma gondii and three factors: 1) method of rodent control, 2) type of production facility, and 3) access of certain animals (cats, dogs, birds) to production facilities. These data indicate that it will be difficult to eliminate T. gondii from swine herds which allow cat or dog access to facilities. Use of cats as a method of rodent control should be discouraged. We found a strong association between use of "bait only" for rodent control and the herd testing negative as compared to the use of "cats only" for rodent control. Greater industry awareness is needed for methods of rodent control through the use of baits. Sows in herds where female replacements were raised internally were significantly more likely to test positive for toxoplasmosis. Sows in confinement facilities had a significantly lower prevalence of Toxoplasma gondii. Herds testing positive were significantly smaller than those which were negative. In general, there were not any regional differences in prevalence rates. Sows testing positive did not have a reduced level of productivity.

Field-Based Assessment of the Role of Porcine Cytomegalovirus in Respiratory Disease of Nursery Pigs

Porcine cytomegalovirus (PCMV) is an ubiquitous infectious agent in swine population throughout the world. Field and some experimental observations have suggested that PCMV plays an important role in causing or enhancing respiratory and/or reproductive disease of swine. However, no actual measure of this has been documented. As the first step in assessing the economic significance of PCMV infection for swine herds in the United States, a field-based case-control study was conducted to evaluate the potential role of the virus in respiratory disease of young swine. The data in this study, thus far, suggest that there may be an association between PCMV infection and increased risk of respiratory disease development in nursery pig populations and that, as was expected, PCMV infection is a common finding among nursery pigs. In an era in which multifactorial respiratory disease and associated decrease in production efficiency is such a large concern, it may be prudent to consider PCMV when developing and implementing strategies for production management and pig flow

Susceptibility of Swine to Hepatitis E virus and its Significance to Human Health

Previous reports indicate that swine can be experimentally infected with Asian isolates of human hepatitis E virus (HEV), which supports epidemiological data indicating that domestic swine can serve as a reservoir for the virus in parts of Asia and as such have the potential to transmit the virus to humans by the fecal-oral route or through contact with pork products. The increasing incidence of human HEV infections in the western hemisphere raises the question of whether or not pigs can play a role in the transmission of this virus in the Americas. Accordingly the susceptibility of swine to a New World isolate of the human hepatitis E virus, Mexico 14, was evaluated. No evidence of infection was detected in experimental pigs. However a high herd and individual prevalence rate for seroreactivity to recombinant HEV antigen was detected in Iowa swine during the selection of experimental pigs. These observations suggests that swine vary in their susceptibility to human HEV isolates. Whether or not swine are susceptible to other New World isolates of HEV and can serve as a reservoir for human infection remains to be determined. The significance of the high rate of seroreactivity of swine to recombinant antigen with respect to human and swine health is not known. An epidemiological study currently in progress should help answer this important question

Amazon.com: Offering Everything from A to Z

Amazon’s focus on customer service has led to an impressive record of growth and profitability. However, late in 2012, the company posted a quarterly loss. This asks whether the company may be sacrificing profits in the interest of growing rapidly. It also explores the incredibly competitive environment Amazon faces