Demography of northern elephant seals, 1911-1982

Northern elephant seals (Mirounga angustirostris) were hunted to near extinction in the 19th century. Protection has allowed them to recolonize former habitat on islands off California, where the population is increasing more than 14 percent per year. Immigration of young pregnant females from Baja California initiated the California rookeries but is responsible for only a small part of recent population growth. Almost 25,000 northern elephant seal pups were born in the species' range in Mexico and the United States in 1982 in comparison with only six known births in 1911.     

智利猕猴桃产业概况

2006年12月,在国家外专局出国项目的支持下,我们一行4人,对智利猕猴桃生产进行了为期一个月的考察学习,现就智利猕猴桃产业发展情况谈谈我们的所得.     

Use of the 13C-octanoic acid breath test for assessment of solid-phase gastric emptying in dogs.

OBJECTIVE: To assess the 13C-octanoic acid breath test for determining gastric emptying in dogs. ANIMALS: 6 healthy adult dogs. PROCEDURE: Food was withheld for 12 hours before each test. Expired air was collected 30 minutes and immediately before each test and at frequent intervals thereafter for 6 hours. Concentration of 13CO2 in expired air was determined by use of continuous-flow isotope-ratio mass spectrometry. Basal concentration of 13CO2 was measured in dogs that were not fed a test meal. Effects of the standard unlabeled test meal on basal concentration of 13CO2 were then assessed. The optimum dose of substrate was determined by measuring 13CO2 concentration after ingestion of the standard test meal containing 50 or 100 mg of 13C-octanoic acid, whereas effect of energy density of the test meal on gastric emptying was determined after ingestion of the standard or high-energy labeled test meal. Gastric emptying coefficient (GEC), time to peak 13CO2 concentration (tmax), and half-dose recovery time (t(1/2)) were calculated. RESULTS: Basal concentration of 13CO2 in expired air was not significantly affected by ingestion of the unlabeled test meal. However, 13CO2 concentration significantly increased in a dose-dependent manner after ingestion of the labeled meal. Gastric emptying coefficient, and were significantly different between dogs fed the standard and high-energy test meals, indicating that ingestion of a high-energy meal delays gastric emptying. CONCLUSIONS AND CLINICAL RELEVANCE: The 13C-octanoic acid breath test may be a useful noninvasive and nonradioactive method for assessment of gastric emptying in dogs.     

CYTOGENETICAL STUDIES OF INFERTILE PIGS

Cytogenetical studies were made on 6 infertile pigs. Post-mortem examination of the reproductive organs of 5 of these pigs showed them to be intersexes. Regardless of the degree of gonadal deviation from the normal, chromosome karyotype of cultured peripheral blood lymphocytes, bone marrow, liver and kidney, revealed that 4 of the intersexes had a 38, XX constitution. One intersex exhibited sex chromosome mosaicism (38XX/38XY) in lymphocytes from the peripheral blood and bone marrow and a normal male karyotype (38XY) in cultured liver and kidney cells. The sixth pig, a phenotypically normal boar, also had a 38XX/38XY chromosome constitution.     

Control of radiation-induced emesis with promethazine, cimetidine, thiethylperazine, or naloxone

Promethazine (2 mg/kg), cimetidine (4 mg/kg), thiethylperazine (0.86 mg/kg), and naloxone (0.08 mg/kg) were each evaluated for their ability to increase the threshold of radiation-induced emesis in the dog. Each dog was fed a can of dog food (ca 0.4 kg) and then injected IM with the appropriate drug 1 hour before being irradiated by a 60Co teletherapy unit. The total radiation dose given an individual dog was determined by an up-and-down exposure schedule. Dogs were then observed continuously for 10 hours while the number, time of onset, and duration of each emetic episode were monitored. The dose of radiation causing emesis in 50% (ED50 +/- SEM) of control dogs was 170 +/- 38.5 rad. The ED50 +/- SEM was increased to 402 +/- 18.6 rad by promethazine, to 331 +/- 27.3 rad by cimetidine, and to 320 +/- 38.5 rad by thiethylperazine. This increased tolerance was significant at P less than 0.05 for each drug. The ED50 for naloxone was 262.5 +/- 92.9 rad, which was not a statistically significant increase in threshold.     

Expornitic of avian pox in a zoo.

During a 6-week period at the San Diego Zoo, avian pox occurred in 9 pheasants representing 5 species. Lesions were limited to facial skin and consisted of epithelial cell hyperplasia, secondary inflammatory changes, and intracytoplasmic eosinophilic inclusion bodies which, by electron microscopy, were shown to contain pox virus. The disease was self-limiting in 7 pheasants, but 2 pheasants died. Free-ranging Indian red junglefowl were implicated as the source of the infection.     

Clinical and pathological findings in two Mauritian pink pigeons (Columba mayeri)

Two Mauritian pink pigeons (Columba mayeri) from a captive breeding programme, with locomotor disorders were examined clinically and post mortem. One bird was unable to fly owing to a permanent luxation of the left elbow. The other bird had an inclined foot caused by a medial curvature and outward rotation of the tarsometatarsal bone, a deformity similar to the previously recorded 'inclined feet' in birds bred in Mauritius.     

Percloacal infection of chickens with Salmonella typhimurium

The characteristics of Salmonella typhimurium infection in hatchlings and adult poultry given by the intravenous, oral and percloacal routes were compared. Based on LD₅₀ determinations, 1-day-old birds were most susceptible to percloacal infection. It is claimed that this infection technique yields predictable results in terms of mortality and numbers of organisms in the liver, spleen and intestinal tissues. Though older birds do not die when given large doses of organisms by this route, small numbers are sufficient to establish transient infection or carriage in the intestine.Based on quantitative data, the course of the percloacal infection appeared similar to that given by the oral route in hatchlings; however, the number of organisms required to establish infection by the former route was significantly less. It is suggested that the percloacal infection route may be a useful model for studying Salmonella infection-immunity in birds, particularly if resistance mechanisms operating in the intestine are to be taken into account. The possibility that it may be an important infection route in natural circumstances must also be considered.