Lunar Cycle Influences Production of Tilapia ( spp) Eggs in an Intensive Outdoor Production System in the Tropics.

A robust body of evidence has demonstrated that the lunar cycle plays an important role in the reproduction of fish living in natural environments. However, little is known about the influence of the moon on tilapia reproductive activity in intensive fish farming systems. This study aims to evaluate the influence of the lunar cycle on the reproductive performance of tilapias in an intensive outdoor tropical production system in Latin America.

Chronic inflammatory and degenerative endometrial lesions in subfertile Criollo Limonero cattle; a B. taurus Latin-American breed threatened with extinction; A case-control study.

Criollo Limonero is a tropical Bos taurus breed for sustainable dual purpose (milk and beef) production in the South-American tropics, which is currently threatened with extinction. The objective was to perform a clinical evaluation and histopathological assessment of uterine biopsy samples of repeat breeder (RB) Criollo Limonero cattle to determine the occurrence of pathological conditions as potential causes of subfertility. Twenty-four Criollo Limonero cattle [18 cows (5-13 years old) and 6 heifers (6-7.

Assessing the effect of selection with deltamethrin on biological parameters and detoxifying enzymes in Aedes aegypti (L.).

Background: Resistance to insecticides through one or several mechanisms has a cost for an insect in various parameters of its biological cycle. The present study evaluated the effect of deltamethrin on detoxifying enzymes and biological parameters in a population of Aedes aegypti selected for 15 generations. The enzyme activities of alpha- and beta-esterases, mixed-function oxidases and glutathione-S-transferases were determined during selection, along with biological parameters.

Frequency of V1016I and F1534C mutations in the voltage-gated sodium channel gene in Aedes aegypti in Venezuela.

Background: The V1016I and F1534C mutations in the voltage-gated sodium channel gene have been associated with resistance to pyrethroids and DDT in Aedes aegypti mosquitoes. A study was carried out to determine the frequency of I1016 and C1534 by real-time PCR in five natural populations of Ae. aegypti in Venezuela during 2008, 2010 and 2012, as well as in a strain selected with 0.

[Dog (Canis familiaris) infectivity to Lutzomyia youngi in Trujillo, Venezuela].

Introduction: In Trujillo, Venezuela the prevalence for American tegumentary leishmaniasis (ATL) is 38 per 100,000 inhabitants.

Objective: In a periurban, rural settlement of the capital city Trujillo, we studied the potential capability of the domestic dog (Canis familiaris) as a source of infection for Lutzomyia youngi, a phlebotomine sand fly species abundant in the study area and whose domestic vectorial activity has been proven.

Materials And Methods: Dogs with dermal lesions suggestive of ATL and parasitological confirmation of infection, were selected for xenodiagnosis by allowing sylvatic phlebotomines from a ATL free area, to feed ad libitum over each animal's entire body surface.

Impact of imported malaria on the burden of disease in northeastern Venezuela.

Background: Many countries throughout the world are reporting an increasing number of imported malaria cases. It is now well documented that population movements play an important role in the spread and introduction of malaria infection in nonendemic areas.

Methods: We evaluated the contribution of imported malaria to the overall malaria burden of disease in an already endemic malaria region in Venezuela, where malaria is exclusively caused by Plasmodium vivax.

Diversity and species composition of sand flies (Diptera: Psychodidae) in a Venezuelan urban focus of cutaneous leishmaniasis.

The present study examined the spatial and temporal abundance and diversity of phlebotomine sand flies in an area of Venezuela that is an ancient focus of leishmaniasis. The study was conducted in 6 stations in urban localities in Trujillo City, located in northwestern Venezuela (9 degrees 22' 24" N, 70 degrees 26' 08" W), which is located in a mountain range in the Andean ecoregion (altitude = 600-1,010 m). During 1995-99, entomological surveys were conducted after and before the rainy season.

[A study of seismic storms occurred from October 1989 to June 1990, in the neighborhood of Pico El Aguila and Piñango, Venezuelan Andes].

Between October 1989 and June 1990 there were a large number of microearthquakes in the neighborhood of Pico El Aguila and Piñango, Mérida State, Venezuela. The epicenters form two clearly separated groups. The first one comprises events which occurred between October 1989 and March 1990.

Antisporozoite antibodies with protective and nonprotective activities: in vitro and in vivo correlations using Plasmodium gallinaceum, an avian model.

A correlation was observed between in vivo and in vitro activity of six monoclonal antibodies (mAb) against the major circumsporozoite protein of the avian malaria Plasmodium gallinaceum as follows. (1) Two mAb were protective, totally abrogating sporozoite infectivity to chicks, its natural host, in vivo; they caused 100% inhibition of sporozoite invasion (ISI) in vitro to SL-29 chicken fibroblasts and intense ISI to cultured chicken macrophages, as well as inhibited the exoerythrocytic development of sporozoites taken up by macrophages, the initial cell host of P. gallinaceum sporozoites.

Factors affecting postpartum ovarian activity in crossbred primiparous tropical heifers.

The relationship between postpartum ovarian activity and a total of 9 variables was studied in a dry tropical environment. Primiparous cows (n=61) that had shown no peripartum abnormalities, and were not suckled but milked twice daily, were used in the study. Independent variables included crossbreeding, sex of the calf, season, body condition, weight of cow at calving, age of dam at calving, uterine involution, calf weight and accumulated milk yield.

[Metacyclics of Leishmania mexicana in the hypopharynx of Lutzomyia youngi experimentally infected].

Although it has been postulated that the natural transmission of leishmaniasis occurs by regurgitation of the parasites from contaminated proboscis of phlebotomine vector recent experimental results seems to oppose this thesis. Wild-caught and laboratory-reared females of Lutzomyia youngi, vector of Leishmania mexicana in the Venezuelan Andes, were infected on tarsal lesion of hamsters, inoculated 6 weeks previously s.c.

[Strategy of Ascaris lumbricoides and Trichuris trichiura for the environmental contamination, in an endemic area].

The distribution of frequencies of the number per grame of Ascaris lumbricoides and Trichuris trichiura in the faeces of naturally infected human in endemic areas, were found following a negative binomial distribution and an overdispersal pattern, independently of the ages of hosts. These results show, that only few hosts, independently of their ages, are involved in the higher environment contamination.

[Ecoepidemiology of Haemonchus contortus bahiensis, ecotype present in sheep of arid zones of Venezuela].

The frequency distribution of female Haemonchus contortus bahiensis Grisi, 1974 in sheep from Venezuelan arid zones is 15.32% for the type with vulvar flap, 51.6% for the vulvar-knob and 33.