The effects of a DNA virus infection on the reproductive potential of female tsetse flies, Glossina morsitans centralis and Glossina morsitans morsitans (Diptera: Glossinidae)

Reproductive anomalies associated with the tsetse DNA virus infection in the female tsetse hosts, Glossina morsitans centralis Machado and Glossina morsitans morsitans Westwood, inoculated with the virus during the 3rd instar larval stage were studied and the data compared to those obtained from the control females injected with sterile physiological saline. Virus infected flies had significantly longer first and second pregnancy cycles (P < 0.0001) and produced pupae that were of significantly less weight in milligrams (P < 0.0001) compared to controls. Transmission of the virus to progeny was not absolute and only 21% of G. m. centralis and 48% of G. m. morsitans first progeny flies from infected females developed salivary gland hypertrophy as a result of transmission from mother to progeny. The virus infected females produced significantly fewere pupae compared to the controls during the experimental period (P < 0.00001).     

Epilepsy and its impact in northwest region of the Central African Republic

This report documents findings from an open trial of dextroamphetamine in the treatment of depression and low energy in AIDS patients. Dextroamphetamine offers the potential for rapid onset of effect and activation properties, both of which are important to persons with late stage HIV illness. Primary inclusion criteria included having a DSM-III-R depressive disorder, debilitating low energy, CD4 cell count below 200 cells/mm3, and no history of drug dependence. The trial consisted of open treatment in a 6-week protocol, with indefinite follow-up. Twenty-four men entered the study, 18 of 19 (95%) patients who completed at least 6 weeks of treatment reported substantial improvement with regard to both mood and energy at a median dosage of 10 mg/day. These results suggest that dextroamphetamine is a potentially effective, fast acting antidepressant treatment for this population and call for a larger, controlled trial.     

Simulation studies of African horse sickness and Culicoides imicola (Diptera:Ceratopogonidae)

A simulation model of African horse sickness in Spain was developed to investigate what factors affect the likelihood of an epidemic after the introduction of the virus. The model included 2 host species (horses and donkeys) and 1 vector species (Culicoides imicola Kieffer). Latin hypercube sampling was used for sensitivity analysis of the model, to include uncertainty in parameter estimates. In general, if an epidemic occurred most hosts were infected. The peak prevalence in midges was low, and never exceeded 3%. Midge population size, the recovery rate in horses, and the time of year when the virus was introduced were the most significant factors in determining whether or not an epidemic occurred. The uncertainty in interbloodmeal interval, removal rate (mortality and recovery) of infectious horses, midge population size, and transmission rates were significant factors in the size of the epidemic. These factors should be priorities for empirical research, and should be considered in the design of control strategies in areas at risk of virus introduction.     

Control of larval Aedes aegypti (Diptera: Culicidae) by cyclopoid copepods in peridomestic breeding containers

HIV infection and AIDS create a unique dilemma for women in their potential for vertical transmission of these conditions. Selected feminist perspectives in ontology, epistemology, and axiology are reviewed to illuminate possible social, cultural, and political circumstances of these women. Drawing both on these perspectives and various sources of data about women with HIV/AIDS, some implications for nursing complete this discussion.     

小足倒毛摇蚊的再描述(双翅目:摇蚊科)

对摇蚊科(Chironomidea)倒毛摇蚊属(Microtendipes Kieffer),1915小足倒毛摇蚊[M.pedellus(De Geer,1776)]进行再描述,并附主要特征图.     

The mosquitoes of Yellowstone National Park (Diptera:Culicidae)

Although antibodies to viruses in both the epizootic hemorrhagic disease virus (EHDV) and bluetongue virus (BTV) sero-groups have been reported from white-tailed deer (Odocoileus virginianus) in Texas (USA), there are few reports of hemorrhagic disease (HD) in these populations. To understand the extent and diversity of exposure to the North American EHDV and BTV serotypes in these deer populations, we serologically tested 685 white-tailed deer collected from November 1991 through March 1992 throughout their range in Texas. Overall, 574 (84%) of deer had antibodies to EHDV or BTV. Prevalence estimates varied according to ecological region, from 57% in the Gulf Prairies to 100% in the northwest Edwards Plateau. Based on serum neutralization tests, the deer had evidence of previous exposures to multiple EHDV and BTV serotypes, with evidence of exposure to two to five serotypes detected in each ecological region. The apparent lack of HD in relation to this high antibody prevalence cannot be explained, but may be related to enzootic stability in which a near perfect host-virus relationship exists.     

Fish as paratenic hosts of Serpinema trispinosum (Leidy, 1852) (Nematoda: Camallanidae)

Third-stage larvae of the nematode Serpinema trispinosum (Leidy, 1852) were collected from the intestine of the freshwater cichlid, Cichlasoma urophthalmus (Günther), from a small lake in Yucatan, Mexico. This is the first record of Serpinema larvae from fishes, and their presence may reflect the importance of fishes as paratenic hosts of turtle parasites in this genus.     

The intervals between the blood-meals of man-biting Simulium damnosum (Diptera: Simuliidae)

Six marking-recapture experiments were carried out with Simulium damnosum in the Cameroon Republic, five in the rain-forest and one in the Sudan-savanna zone. Adult flies were marked by applying a small spot of oil paint to the mesonotum while they were engorging with blood on the legs of volunteers infected with Onchocerca volvulus microfilariae. Catches of wild flies were carried out for 12-13 days after the first day of marking, and all marked flies recaptured were examined. Some of the flies recaptured on days 0, 1 and 2 were nulliparous and had probably been disturbed by the application of the paint before they had completed their blood-meal. The frequency distribution of recaptured marked parous flies returning for their "second" blood-meal rose to a peak early on day 4, but more flies returned earlier,three days after taking a blood-meal, than later on day 5. After day 5, the numbers of recaptured flies were too low to demonstrate any peaks corresponding to "third" and later blood-meals. The longest surviving fly was recaptured 10 days after marking. Twenty-six percent of the flies recaptured on days 3 and 4 contained developing O. volvulus larvae three-five days old, which had presumably been ingested as microfilariae during the blood-meal taken on day 0. Infective larvae first appeared in flies returning late on day 6, and the highest percentage of infective flies occurred on day 7. Infective larvae were found in recaptured flies until day 10, the last day on which marked flies were recovered. Of 929 flies marked on the Sudan-savanna experiment, three (0-32%) flies were recaptured. Two returned on day 4 and one on day 6.     

The synanthropy of the calliphorids (Insecta, Diptera) of Curitiba, Paraná, Brazil]

The tolerance of electrical responses in the CA1 neurons of guinea pig hippocampal slices to elevated temperatures was studied by recording orthodromic and antidromic responses of the population spike (PS). Increasing the temperature of the perfusing medium from 30 degrees C to 49 degrees C resulted in a decreased amplitude of both the orthodromic and antidromic PS, the former disappearing at 42.0 +/- 1.8 degrees C and the latter at 46.2 +/- 1.3 degrees C (n = 8 for both). When the temperature was increased to 44 degrees C, maintained at this level for less than 27 min, then lowered to 30 degrees C, both the orthodromic and antidromic PS recovered within 60 min. When the temperature was increased to 45-49 degrees C, marked irreversible effects were seen with the orthodromic PS, recovery being dependent on the maximum temperature and duration of exposure, the change becoming irreversible after 13 min at 45 degrees C, 6 min at 46 degrees C, 4 min at 47 degrees C or 2.5 min at 48 degrees C. In contrast, the antidromic PS, recorded simultaneously, recovered on lowering the temperature to 30 degrees C in all cases tested, except when the temperature was increased to 46 degrees C and maintained at this level for 25-27 min. These results indicate that, in CA1 neurons, temperatures above 44 degrees C have more potent irreversible effects on synaptic transmission than on axonal or somal function.     

Bioecology in Haiti of Anopheles albimanus Wiedemann, 1820 (Diptera:Culicidae)

The association of prostate cancer mortality and testicular cancer mortality with environmental exposure to the anti-androgen dichlorodiphenyltrichloroethane (DDT) derivative p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in the USA was explored in the period 1971-1994 using multiple linear regression analysis. Environmental p,p'-DDE contamination by state was estimated by p,p'-DDE concentrations in the subcutaneous fat of population samples and by measurements of p,p'-DDE in tree bark. On average, African Americans had adipose p,p'-DDE levels 74% higher than Whites (8.49 vs. 4.88 microg/g; p < 0.001). Neither prostate cancer mortality nor testicular cancer mortality showed a positive association with either indicator of p,p'-DDE environmental contamination. On the contrary, the regression coefficient for prostate cancer was constantly inverse for adipose p,p'-DDE along the period of study, although it approached statistical significance only for African Americans in 1981-1985 (P=-0.755; 0.10 > p > 0.05). This ecologic study does not provide support to the hypothesis of a link between environmental exposure to DDT derivatives and cancer of the male reproductive tract.     

特务政治,揭开民国最黑暗的一面(一)

戴笠的"军统局"正式挂牌 1938年3月29日至4月6日,国民党五届四中全会在武汉召开.这次会议除了议决有关抗战的政治军事大计,通过<抗战建国纲领>外,还做出了大力扩充特务组织的决定.     

特务政治,揭开民国最黑暗的一面(二)

军统局的"临澧特别训练班" 1937年9月军统局在湖南临澧开设的"军委会特训班",在其历史上具有重要的意义和作用.     

Phage-typing and tetracycline resistance in Salmonella panama strains of animal origin in the Federal Republic of Germany (1969-1975) (author's transl)

505 out of 1369 S. panama strains isolated mainly from animals, foods, and feedstuffs from 1969 to 1975 were phage-typed. 41% (= 207) of the S. panama isolates examined originated from swine, 26% from cattle and calves, 15% from dogs, and 13% were from other animal species and materials. 465 strains (=92%) showed typical reactions. 23% were specified as phage-type A, 24% as phage-type B and 36% as phage-type G. Phage-types D, E, and F did not occur. In swine, being the most frequent carriers of S. panama, phage-types A, B, and G had nearly the same shares. In dogs, phage-type G predominated to which nearly one half of the examined S. panama isolates from this species belonged. 205 (=41%) out of 505 strains examined for their resistance to antibiotics proved to be tetracycline-resistant. All 123 strains of phage-type B were tetracycline-resistant, all 35 strains of phage-type C were tetracycline-sensitive. 5 strains of phage-type A exhibited transferable tetracycline-resistance determinants.     

1st isolation of Aedes (Ochlerotatus) sticticus (Diptera, Culicidae) in the Po-Venetian valley

Aedes sticticus is recorded for the first time in northern Italy. The species was collected in some relict woods mainly at sea level in the Po-Venetian valley (Northern-Italy). Larval growth took place in residual puddles originated by rain or river floods. The most abundant adult emergence was observed in April or May. Minor earlier or later adult emergencies were observed depending from egg submersion and temperature. Data on larval chetotaxy are presented.     

Breeding structure of screwworm fly populations (Diptera: Calliphoridae) in Colima, Mexico

Starch gel electrophoresis was used to resolve gene frequencies among populations of screwworm, Cochliomyia hominivorax (Coquerel). The loci examined coded for alpha-glycerophosphate dehydrogenase, octanol dehydrogenase, and phosphoglucomutase. Flies were sampled by traps widely distributed in Colima Province, southwestern Mexico. Gene frequencies at Odh differed significantly among the 11 populations. Alleles segregating at Pgm and alpha-Gpdh were homogeneous among populations. There were significant departures from random mating within populations, but no genetic differentiation among populations was detected. The data suggest unrestricted gene flow among populations. Departures from random mating within populations were explained by the pooling of samples from separate breeding units.