Influences of Follicular Size on Parthenogenetic Activation and in Vitro Heat Shock on the Cytoskeleton in Cattle Oocytes

The availability of cow ovaries from the slaughterhouse has been very limited in Taiwan. To maximize the use of cow ovaries for research purposes, whole ovary dissection was performed and the developmental competence of the oocytes derived from different sizes of follicles was assessed by the rates of in vitro maturation (IVM) and parthenogenetic activation of the oocytes in Experiment 1 (Exp 1). Cumulus-oocyte complexes (COCs) derived from small (1-2 mm) and large (3-8 mm) follicles were subjected to standard IVM culture for 24 h. Mature oocytes were selected and then parthenogenetically activated using A23187 (5 microm, 5 min) or thimerosal (200 microm, 10 min) alone or combined with 6-dimethylaminopurine (2.5 mm and 3.5 h, respectively). Activation rates of the oocytes, neither from the large nor small follicles, were affected by different activation treatments (single or combined stimuli). Whereas maturation rates for the oocytes from large follicles were superior to those from small follicles in both the single (59% vs 45%) and combined treatments (76% vs 40%; p < 0.05). To understand how prolonged heat shock (HS) influences cytoskeletal configurations of mature bovine oocytes, in Experiment 2 (Exp 2), matured oocytes derived from large follicles were randomly allocated to different durations of HS treatments at 41.5 degrees C for 0 (C0h, control, n = 12), 1 (HS1h, n = 28), 2 (HS2h, n = 31), and 4 h (HS4h, n = 30). An additional control group was cultured for 4 h without HS (38.5 degrees C, 4 h, n = 35). Alterations in nuclear structures, microtubules (MTs), and microfilaments (MFs) of the oocytes were examined. Abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with cytoplasmic MTs increased with time of HS treatment. The intensity of the MF distribution in the HS oocytes was also altered. Significant changes in the cytoskeleton after HS may be associated with the reduced development under hyperthermia and, perhaps, with the low pregnancy rates of the animals during hot seasons.     

Schizophrenia: dopamine beta-hydroxylase activity and treatment response

Cerebrospinal fluid levels of dopamine beta-hydroxylase, found to be relatively constant over time in individual patients, were significantly lower in schizophrenic patients who became nonpsychotic during neuroleptic treatment than in those who remained psychotic. Dopamine beta-hydroxylase activity may delineate a subgroup of patients who have a dopamine-sensitive brain disorder.     

Elevation change of the southern greenland ice sheet

Seasat and Geosat satellite altimeter measurements for the Greenland ice sheet (south of 72 degreesN latitude) show that surface elevations above 2000 meters increased at an average rate of only 1. 5 +/- 0.5 centimeters per year from 1978 to 1988. In contrast, elevation changes varied regionally from -15 to +18 centimeters per year, seasonally by +/-15 centimeters, and interannually by +/-8 centimeters. The average growth rate is too small to determine if the Greenland ice sheet is undergoing a long-term change due to a warmer polar climate.     

Cucumber mosaic cucumovirus incidence in open‐field tomato in the Olympia area and trap captures of alate aphids*

Cucumber mosaic cucumovirus (CMV) has been the most serious pathogen of tomato in Greece for the last 15 years, causing tomato shrinkage, tomato necrosis and tomato fruit necrosis. In an epidemiological study in Eleia county, one of the main centres of production of processing tomato in Greece and one most affected by CMV, it was confirmed that the virus had an extremely high frequency. Disease frequency and severity was found to have a patchy spatial and temporal distribution at county, zone and locality level, during the years and within 1998, the main year of experimentation (and a disastrous year for CMV). Great variation was found in the trends of infection frequencies during the growing season of 1998 in the 15 experimental fields but all were finally 100% or almost 100% infected. The trends of infection frequency in these 15 fields paralleled total captures of alate aphids by a Rothamsted‐type trap, whereas in one of these fields, with a Moericke‐type trap, these parallel captures were composed almost exclusively of Aphis spiraecola.     

网络传播者的道德教育研究

在虚拟的网络世界中, 构建网络道德, 很大程度上要依赖于网络传播者的道德和素质。本课题试图通过探讨网络传播者的思想道德素质状况, 分析如何加强传播者的网络道德教育, 提升其道德自律能力, 从而促进网络道德体系和网络文明建设。     

Survey of tuberculin testing in Swedish zoos.

Tuberculin test results from 214 animals in three Swedish zoos, tested between the years 1993 and 2000, were compiled from a questionnaire sent out to zoo veterinarians. Comparative testing with bovine and avian tuberculin was used on various sites of injection. A total of five skin test reactors were found: three cotton-top tamarins (Saguinus oedipus) in one zoo and two tapirs (Tapirus terrestris) in another zoo. Postmortem culture from one of the tapirs revealed growth of Mycobacterium tuberculosis, and a stamping out policy was adopted in the herd. Tuberculosis in the primates was ruled out by further investigations. Zoo veterinarians should try to adopt a common scheme for the regular testing of zoo animals to improve the diagnostic ability and comparison of results between institutions.