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111.
112.
New epidemiological features on animal trypanosomiasis by molecular analysis in the pastoral zone of Sideradougou, Burkina Faso 总被引:2,自引:0,他引:2
T. LEFRANÇOIS P. SOLANO S. DE LA ROCQUE† Z. BENGALY J. M. REIFENBERG I. KABORE & D. CUISANCE 《Molecular ecology》1998,7(7):897-904
A multidisciplinary work was undertaken in the agropastoral zone of Sidéradougou, Burkina Faso to try to elucidate the key factors determining the presence of tsetse flies. In this study the PCR was used to characterize trypanosomes infecting the vector ( Glossina tachinoides and Glossina palpalis gambiensis ) and the host, i.e. cattle. A 2-year survey involved dissecting 2211 tsetse of the two Glossina species. A total of 298 parasitologically infected tsetse were analysed by PCR. Trypanosoma vivax was the most frequently identified trypanosome followed by the savannah type of T. congolense and, to a lesser extent, the riverine forest type of T. congolense , and by T. brucei . No cases of T. simiae were found. From the 107 identified infections in cattle, the taxa were the same, but T. congolense savannah type was more frequent, whereas T. vivax and T. congolense riverine forest types were found less frequently. A correlation was found between midgut infection rates of tsetse, nonidentified infections and reptile bloodmeals. These rates were higher in G.p. gambiensis , and in the western part of the study area. T. vivax infections were related to cattle bloodmeals, and were more frequent in G. tachinoides and in the eastern study area. The PCR results combined with bloodmeal analysis helped us to establish the relationships between the vector and the host, to assess the trypanosome challenge in the two parts of the area, to elucidate the differences between the two types of T. congolense , and to suspect that most midgut infections were originating from reptilian trypanosomes. 相似文献
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D. Pauly J. Moreau Ma. Lourdes D. Palomares 《Zeitschrift fur angewandte Ichthyologie》1988,4(4):190-193
The growth, standing stocks and production of tilapia Sarotherodon melanotheron (Cichlidae) in the 1 km2 Sakumo Lagoon near Tema, Ghana, are estimated by application of recently developed models to previously published data. The new estimates are used to obtain values of food (i.e. sediment) consumption, some related statistics, and to assess bioturbation as caused by S. melanotheron.
Detritus, Energieverbrauch und Konversionseffizienz von Sarotherodon melanotheron (Cichlidae) in einer westafrikanischen Lagune
Das Wachstum, die Biomasse und die Produktion von Tilapia Sarotherodon melanotheron (Cichlidae) in der 1 km2 Sakumo Lagune bei Tema, Ghana, wurden bestimmt auf der Basis von neueren Modellen und bereits veröffentlichten Daten. Die neuen Modellparameter werden benutzt, um die Nahrungs-, d. h. Sedimentkonsumption und verwandte Größen zu bestimmen, und um die Bioturbation zu schätzen, die S. melanotheron verursacht.
Détritus, dépense d'énergie et efficience de la conversion de Sarotherodon melanotheron (cichlidés) dans une lagune en Afrique de l'ouest
La croissance, la biomasse et la production du tilapia Sarotherodon melanotheron (Cichlidés) ont été estimées pour le stock de la lagune de Sakumo (1 km2 ), près de Tema, Ghana, en utilisant des modèles recents et des données déjà publiées. Les nouvelles valeurs sont utilisées pour l'estimation de la consommation en nour re (= sediment) ainsi que quelques autres charactéristiques de S. melanotheron , et pour estimer le taux de bioturbation qui résulte de ses activités. 相似文献
Zusammenfassung
Detritus, Energieverbrauch und Konversionseffizienz von Sarotherodon melanotheron (Cichlidae) in einer westafrikanischen Lagune
Das Wachstum, die Biomasse und die Produktion von Tilapia Sarotherodon melanotheron (Cichlidae) in der 1 km
Résumé
Détritus, dépense d'énergie et efficience de la conversion de Sarotherodon melanotheron (cichlidés) dans une lagune en Afrique de l'ouest
La croissance, la biomasse et la production du tilapia Sarotherodon melanotheron (Cichlidés) ont été estimées pour le stock de la lagune de Sakumo (1 km
115.
Detection of salmonellas by DNA hybridization with a fluorescent alkaline phosphatase substrate 总被引:3,自引:3,他引:0
R. J. Cano M.J. Torres R.E. Klem J.C. Palomares J. Casadesus 《Journal of applied microbiology》1992,72(5):393-399
R. J. CANO, M.J. TORRES, R.E. KLEM, J.C. PALOMARES AND J. CASADESUS. 1992. This study evaluates a DNA hybridization assay for salmonella with A tto P hos ™ (JBL Scientific, San Luis Obispo, CA), a fluorescent substrate for alkaline phosphatase. The probe used (50 ng/ml) was a biotinylated 600 bp fragment consisting of a tandem repeat of an insertion sequence (IS200) found in most Salmonella spp. evaluated. The hybridization was carried out at 65°C for 2 h without prior prehybridization and hybrids were detected by the addition of a streptavidin-alkaline phosphatase conjugate. Circles (5 mm) were cut from the membrane and placed in a cuvette containing 1 ml of 1 mmol/1 A tto P hos ™. The reaction was evaluated after 30 min at 37°C with a fluorometer with an excitation wavelength of 440 nm and an emission wavelength of 550 nm. The sensitivity of the probe was estimated to be 10 000 copies of target DNA or 5 times 10-20 mol of DNA. All 74 salmonella strains tested reacted with the probe but none of the 98 heterologous species tested gave positive results. The results of this study indicate that our assay method, which employs a biotinylated tandem repeat of IS200 and A tto P hos ™, is a specific and highly sensitive quantitative method for the detection of salmonellas. 相似文献
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A. G. DE LA FILIA S. ANDREWES J. M. CLARK L. ROSS 《Medical and veterinary entomology》2018,32(2):226-234
Insect reproduction is extremely variable, but the implications of alternative genetic systems are often overlooked in studies on the evolution of insecticide resistance. Both ecotypes of Pediculus humanus (Phthiraptera: Pediculidae), the human head and body lice, are human ectoparasites, the control of which is challenged by the recent spread of resistance alleles. The present study conclusively establishes for the first time that both head and body lice reproduce through paternal genome elimination (PGE), an unusual genetic system in which males transmit only their maternally derived chromosomes. Here, we investigate inheritance patterns of parental genomes using a genotyping approach across families of both ecotypes and show that heterozygous males exclusively or preferentially pass on one allele only, whereas females transmit both in a Mendelian fashion. We do however observe occasional transmission of paternal chromosomes through males, representing the first known case of PGE in which whole‐genome meiotic drive is incomplete. Finally, we discuss the potential implications of this finding for the evolution of resistance and invite the development of new theoretical models of how this knowledge might contribute to increasing the success of pediculicide‐based management schemes. 相似文献
119.
Fruit morphology in Tragopogon L. (Compositae: Lactuceae) from the Iberian Peninsula 总被引:2,自引:0,他引:2
G. BLANCA C. DÍAZ DE LA GUARDIA 《Botanical journal of the Linnean Society. Linnean Society of London》1997,125(4):319-329
Achenes of all the Tragopogon species from the Iberian Peninsula were examined by means of scanning-electron microscopy and stereomicroscopy. The achenes of the eight species are described, illustrated and compared. The results are contrasted with the systematics of this genus. The isolated position of T. lamottei with regard to the other seven species is noted. A key is provided to enable the different species to be distinguished. 相似文献
120.
First record in America of Aedes albopictus naturally infected with dengue virus during the 1995 outbreak at Reynosa, Mexico 总被引:2,自引:0,他引:2
SERGIO IBÁÑEZ-BERNAL BALTASAR BRISEÑO JOHN PAUL MUTEBI ENID ARGOT GUADALUPE RODRÍGUEZ CARMEN MARTINEZ-CAMPOS RAFAEL PAZ PEDRO DE LA FUENTE-SAN ROMÁN† ROBERTO TAPIA-CONYER‡ ANA FLISSER 《Medical and veterinary entomology》1997,11(4):305-309
Abstract Mosquito collections were conducted during a dengue outbreak in Reynosa, Tamaulipas, Mexico, July-December 1995. A total of 6694 adult mosquitoes (four genera and nine species) were captured, of which 2986 (78.3% females and 21.7% males) were Aedes albopictus and 2339 (39.7% females and 60.3% males) were Ae.aegypti. These two species comprised 84.2% of the total collection. Specimens were grouped into pools, nearly 50% of them processed for detection of virus by cythopathic effect in C6-36 and VERO cell cultures and by haemagglutination test. Five pools gave positive haemagglutin-ation reactions and were examined by immunofluorescence using monoclonal antibodies to flavivirus and to dengue virus. One pool of ten Ae.albopictus males was positive for dengue virus: serotypes 2 and 3 were identified by serotype-specific monoclonal antibodies arid confirmed by RT-PCR. This is the first report of Ae.albopictus naturally infected with dengue virus in America. Also, it is the very first time Ae.albopictus males have been found infected with dengue virus in the wild. 相似文献