Defining a Safe Operating Space for inland recreational fisheries

The Safe Operating Space (SOS) of a recreational fishery is the multidimensional region defined by levels of harvest, angler effort, habitat, predation and other factors in which the fishery is sustainable into the future. SOS boundaries exhibit trade‐offs such that decreases in harvest can compensate to some degree for losses of habitat, increases in predation and increasing value of fishing time to anglers. Conversely, high levels of harvest can be sustained if habitat is intact, predation is low, and value of fishing effort is moderate. The SOS approach recognizes limits in several dimensions: at overly high levels of harvest, habitat loss, predation, or value of fishing effort, the stock falls to a low equilibrium biomass. Recreational fisheries managers can influence harvest and perhaps predation, but they must cope with trends that are beyond their control such as changes in climate, loss of aquatic habitat or social factors that affect the value of fishing effort for anglers. The SOS illustrates opportunities to manage harvest or predation to maintain quality fisheries in the presence of trends in climate, social preferences or other factors that are not manageable.     

Evaluation and extension of the cusum technique with an application to Salmonella surveillance.

The cumulative sum (cusum) technique was examined for its use in a disease surveillance system for detecting temporal clusters of events. Optimal technique parameters were derived for scenarios not previously considered. Simulation modeling produced results that evaluated deviations from predefined rate increases. The cusum technique was less prone to false alarms and more efficient at detecting large rate increases than previously reported. As demonstrated using data obtained from a Salmonella surveillance system operated by a state animal diagnostic laboratory system, the cusum technique could provide early warning of an epidemic problem.     

Nonangiogenic and nonlymphomatous sarcomas of the canine spleen: 57 cases (1975-1987)

The case records of and histopathologic findings in 57 dogs with nonangiogenic and nonlymphomatous splenic sarcomas were reviewed. Splenic neoplasms in these dogs included leiomyosarcoma, fibrosarcoma, undifferentiated sarcoma, liposarcoma, osteosarcoma, chondrosarcoma, myxosarcoma, rhabdomyosarcoma, and fibrous histiocytoma. The clinical signs associated with splenic sarcoma included anorexia or decreased appetite, abdominal distention, polydipsia, lethargy, vomiting, weight loss, and weakness. An abdominal mass was detected in 86% of the dogs by use of abdominal palpation (63%), and/or abdominal radiography (74%). The diagnosis was based on histopathologic findings in the spleen. Abdominal exploratory surgery was performed on 43 of the 57 dogs. Twenty-seven dogs were treated by splenectomy, and 16 were euthanatized at the time of surgery because of widespread metastatic lesions. Of the 14 dogs on which surgery was not performed, 11 were euthanatized on the basis of results of preoperative diagnostic tests, and the remaining 3 dogs had splenic neoplasms that were incidental findings at necropsy. Of the 27 surgically treated dogs, 5 died in the immediate postoperative period, 12 died or were euthanatized within 1 year after splenectomy, and only 5 dogs survived greater than or equal to 1 year. Three dogs were lost to follow-up evaluation, and 2 were still alive 6 and 7 months after surgery. The median survival time of the 22 dogs for which survival was known was 2.5 months. The median survival time for 11 dogs with no obvious metastasis at the time of splenectomy was 9 months.(ABSTRACT TRUNCATED AT 250 WORDS)     

Polyarteritis nodosa and rheumatic heart disease in a dog

A 12-year-old spayed Corgi-type dog developed an acute febrile illness about 2 weeks after excision of a subcutaneous arteriovenous fistula. The dog was moribund after 1 week of illness and was euthanatized. Necropsy disclosed uncommon lesions comparable to those of polyarteritis nodosa and rheumatic heart disease of human beings. The pathogenesis of the arterial and cardiac lesions was not established, but was consistent with that of an immune-mediated mechanism.     

Differentiation of field isolates of Pasteurella multocida serotype 3,4 from live vaccine strain by genotypic characterization

Fifty-five serotype 3,4 isolates of Pasteurella multocida, isolated from turkeys dead from fowl cholera, were characterized (fingerprinted) genotypically for comparison with the serotype 3,4 live fowl cholera vaccine principally used in turkeys in California. Twenty-three isolates were obtained from turkeys vaccinated with the M9 live vaccine, and 32 additional isolates were from turkeys not vaccinated for fowl cholera. Methods of characterization included restriction endonuclease analysis of chromosomal DNA and ribotyping, a technique for highlighting restriction site heterogeneity of highly conserved ribosomal RNA genes and associated sequences using a radiolabeled rRNA probe. Eight different genotypes or ribotypes were detected in these isolates by the above methods. Of 23 isolates from M9-vaccinated turkeys flocks, 19 were the same ribotype as M9. Thirty of 32 isolates recovered from unvaccinated turkeys were different ribotypes from M9. The remaining two isolates resembled M9 and were recovered from two different flocks placed in succession on a turkey farm where a flock placed previously had been vaccinated with M9, suggesting interflock transmission. Ribotyping and restriction endonuclease analysis appear to be useful tools to aid in the determination of the role that the live vaccine plays in fowl cholera epidemiology.     

Distinctive unclassified mesenchymal tumor of the digit of dogs.

Four examples of a mesenchymal tumor of undetermined histogenesis occurred in three mixed-breed dogs and one Yorkshire terrier. All tumors occurred as solitary, soft to firm, solid, tan, and ulcerated masses in the digits of dogs aged 11 to 15 years. The compact cellular tumor had cells with anisokaryotic round, oval, or irregular nuclei, some of which were multinucleated. The neoplastic cells appeared to arise in the tissue near the third phalanx in the area of dense collagenous trabeculae located proximal to the fat pad and sweat glands. The unclassifiable cells had some features of histiocytes by transmission electron microscopy, but failed to stain for lysozyme and alpha-1-antichymotrypsin, markers for monocyte-macrophage derived cells. Immunohistochemically, the cells stained for vimentin but not for cytokeratins, desmin, S-100 protein, epithelial membrane antigen, alpha-lactalbumin, lysozyme, alpha-1-antichymotrypsin, alpha-lactalbumin, casein, and heavy and light chain immunoglobulins. The combined findings of light and transmission electron microscopy and immunohistochemistry exclude tumor histogenesis from an epithelial cell, melanocyte, mast cell, plasma cell, Schwann cells, and Merkel cell.     

A statistical model to optimize enzyme-linked immunosorbent assay parameters for detection of Mycoplasma gallisepticum and M. synoviae antibodies in egg yolk

An enzyme-linked immunosorbent assay (ELISA) was developed to quantify Mycoplasma gallisepticum (MG) and M. synoviae (MS) antibodies in egg-yolk extract. Various parameters of ELISA were evaluated and optimized. A statistical model was developed to study the relationship between ELISA absorbance (A) and antigen concentration, antibody concentration, and time of reading of the test. These factors explained 62% of the variability in A for the MG antigen and 74% of the variability in A for the MS antigen. The optimum concentration of MG antigen was 4 micrograms protein/ml, and that for MS antigen was 3 micrograms protein/ml. A similar model was developed to study the relation between A and conjugate concentration, antibody concentration, and time of reading of the test. The optimum concentration of the conjugate was found to be 1:4000. The within-run and between-run coefficients of variation for MG were 8% and 9%, respectively, and those for MS were 9% and 7%, respectively, indicating a high degree of reproducibility of these tests. There was a high correlation between ELISA and hemagglutination-inhibition test results.