Biomedical subjects

R Anderson-Sprecher

Publications and source records attributed to R Anderson-Sprecher.

4 recordsLinked to original sources

PubMed2000

Evidence of point-source exposure to Neospora caninum and protective immunity in a herd of beef cows.

OBJECTIVE: To determine whether cows with evidence of previous infection with Neospora caninum were less likely to abort or give birth prematurely during an outbreak of neosporosis, compared with herdmates with evidence of primary infection. DESIGN: Cohort study. ANIMALS: 208 pregnant beef cows. PROCEDURES: Aborted fetuses and calves born prematurely were examined during an outbreak of neosporosis in a herd of beef cows. Sera were collected from all cows during the outbreak and again 71 days later. Cows were classified into groups on the basis of normal and abnormal reproductive outcomes. Sera were examined, using an avidity ELISA procedure for N caninum, and results were compared between groups and among time points. RESULTS: Antibody concentrations decreased significantly and IgG avidity values increased significantly over time. During the outbreak, cows with normal reproductive outcomes were significantly more likely to have high IgG avidity values than cows with abnormal reproductive outcomes. CONCLUSIONS AND CLINICAL RELEVANCE: The herd had numerous abortions and premature births with evidence of recent point-source exposure to N caninum. Therefore, to reduce risk of transmission of N caninum to cattle, attempts should be made to prevent canine feces from contaminating feed, especially feedstuffs used to prepare mixed rations for cattle. Cows with evidence of previous exposure to N caninum were less likely to abort or give birth prematurely during the outbreak than cows with primary infections with N caninum; this finding suggests development of protective immunity in previously infected cows.

Abortion, Spontaneous↗

PubMed1997

Antibody responses of cows during an outbreak of neosporosis evaluated by indirect fluorescent antibody test and different enzyme-linked immunosorbent assays.

Serum samples from 70 (33 aborting and 37 non-aborting) dairy cows from a herd in California were analyzed for Neospora caninum antibodies in different laboratories by various serologic assays including enzyme-linked immunosorbent assay (ELISA) with recombinant antigens (Nc4.1 and Nc14.1), kinetic ELISA, whole tachyzoite lysate ELISA, immunostimulating complex (iscom) ELISA, antigen capture competitive inhibition ELISA, and by the indirect fluorescent antibody test. Eighteen percent of pregnant cows in this herd had aborted within 2 mo of the index case. All 70 cows had antibodies to N. caninum by at least 1 of the tests. Antibody levels to N. caninum in aborting cows as a group were higher than in nonaborting cows. However, it was concluded that no serological test could be used to establish definitively that N. caninum caused the abortion in an individual cow.

Abortion, Veterinary↗

PubMed1994

Robust estimates of wildlife location using telemetry data.

The location of wildlife is frequently determined using telemetry data gathered at short intervals. If radio transmissions are reflected, as often occurs in mountainous regions, then existing location estimation techniques re unreliable. We explore the effects of gross observation errors upon current analyses and suggest an alternative analysis based on robust state-space time-series modeling. We determine location estimates and their precisions, both for simulated and real mule-deer data, using current and robust procedures. Implementation and specification of filter parameters are also discussed. We conclude that the proposed filter-smoother is similar to the Gaussian filter-smoother when data are not greatly contaminated and that the robust version improves upon location estimates when contamination is large.

Animal Identification Systems↗

PubMedDate not supplied

Environmental sampling: a brief review.

Proper application of statistical principles at the onset of an environmental study can make the difference between an effective, efficient study and wasted resources. This review distills some of the thoughts current among environmental scientists from a variety of backgrounds and organizes them according to statistical principles. Collection and review of preliminary information is important for guiding sampling design. Problems must be carefully defined before rational sample selection is possible. Many potential sources of variability exist, and as many of these sources as possible should be identified, assessed, and, ideally, minimized. Sample selection itself will depend on the precise questions that are to be addressed by the study and on what assumptions can be reasonably made about structures and patterns of contaminants in the field. Careful specification of protocols for sample procurement are needed. Choices of statistical analyses will depend on how data are collected, and intended analyses should be predetermined as part of the sampling plan. Proper attention to these principles will substantially increase the quality and efficiency of an environmental sampling program.

Data Collection↗