174,583 research outputs found
Mares y océanos - Órbita Laika
No full text¿Cuál es el origen de la vida? Hay teorías que dicen que la vida vino del espacio exterior. Otras que surgió del interior terrestre. Y otras dicen que la vida surgió en el mar.
El caso es que, como dijo Arthur C. Clark, “sería más apropiado llamar al planeta Tierra por el nombre de Planeta Océano”. No le faltaba razón.
Tres cuartas partes de la superficie de nuestro planeta es agua y, en ella, habita más del 90% de las especies. Sabemos que no hemos explorado ni el 5% del océano, que las especies marinas conocidas son, más o menos, 250 mil y las desconocidas, más de un millón.
Quizá los mares acaben dándonos la respuesta a cuál es el origen de la vida. Quién sabe. Ponte el bañador y prepárate para un auténtico chapuzón científico, porque Óbita Laika se zambulle en los “Mares y Océanos”Peer reviewe
Effect of copper supplementation on copper status of pregnant mares and foals
No full textPregnant Thoroughbred mares (n=21) were grazed on tall fescue pasture containing Cu 4.4-8.6 mg/kg DM. Twelve mares were supplemented daily with Cu 0.5 mg/kg liveweight (LW) as copper sulphate for the final 13-25 weeks of gestation. Plasma Cu declined during the third trimester for all mares and was not affected by Cu supplementation. Liver Cu concentration of mares and foals was estimated when foals were 4-10 days old. Cu supplementation of mares tended to increase mare liver Cu level and also foal liver Cu (P<0.01). There was a significant relationship between mare and foal liver Cu level (P<0.001, r² = 0.7). It is concluded that increasing the Cu intake of mares is effective in enhancing the Cu status of foals.ID: 699; Accession Number: 19981409815. Publication Type: Journal Article. Language: English. Number of References: 33 ref. Registry Number: 7440-50-8. Subject Subsets: Veterinary Science; Animal NutritionSource type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=lah&AN=19981409815&site=ehost-liv
Exposure to stallion accelerates the onset of mares' cyclicity.
No full textHorses (Equus caballus) belong to the group of seasonally polyestrous mammals. Estrous cycles typically start with increasing daylight length after winter, but mares can differ greatly in the timing of onset of regular estrus cycles. Here, we test whether spatial proximity to a stallion also plays a role. Twenty-two anestrous mares were either exposed to one of two stallions (without direct physical contact) or not exposed (controls) under experimental conditions during two consecutive springs (February to April). Ovarian activity was monitored via transrectal ultrasound and stallion's direct contact time with each mare was determined three times per week for one hour each. We found that mares exposed to a stallion ovulated earlier and more often during the observational period than mares that were not exposed to stallions. Neither stallion identity nor direct contact time, mare age, body condition, size of her largest follicle at the onset of the experiment, or parasite burden significantly affected the onset of cyclicity. In conclusion, the timing of estrous cycles and cycle frequency, i.e., crucial aspects of female reproductive strategy, strongly depend on how the mares perceive their social environment. Exposing mares to the proximity of a stallion can therefore be an alternative to, for example, light programs or elaborated hormonal therapies to start the breeding season earlier and increase the number of estrous cycles in horses
Synthesis of a novel series of imidazo[4,5-c]pyrazole derivatives and their evaluation as herbicidal agents
No full textEver changing problems in agricultural weed control require periodic introduction of new herbicides. Imidazo[4,5-c]pyrazoles, which were considered of interest as potential herbicides, were synthesized and examined for the pre-emergence, post-emergence, and post-transplant control of weeds in rice against broadleaf and grass weed species. The data obtained suggest that some imidazo[4,5-c]pyrazoles have potential herbicidal activity against a wide range of weeds, with 5-methyl, 5-thiomethyl, and 5-unsubstituted derivatives being the most effective. No herbicidal activity was observed in the 5-methylsulfonylimidazo[4,5-c]pyrazole and imidazo[4,5-c]pyrazolone series
Pyrazolo[3,4-c]isothiazole and isothiazolo[4,3-d]isoxazolederivatives as antifungal agents
No full textContext: The diseases of plants and humans due to pathogenic fungi are increasing. Among the substances used tocombat fungi, the azoles are of primary interest, both in agricultural field both in health. To avoid fungal resistancephenomena, the synthesis and tests of new derivatives are necessary.Objective: This article discusses the synthesis and the antifungal activity of pyrazolo[3,4-c]isothiazole andisothiazolo[4,3-d]isoxazole derivatives against three fungi that are pathogenic only for plants and two fungi that areopportunistic in humans and plants.Materials and Methods: The compounds were prepared starting from 2-cyano-3-ethoxy-2-butenethioamide. Theantifungal activity of the compounds was determined by measuring the inhibition of growth of the fungi tested at20, 50, and 100 μg/mL in comparison with the controls.Results: Results demonstrated that several compounds were able to control the mycelial growth of the tested fungi,even if they showed different sensitivity to the different azole-derivatives. In general Magnaporthe grisea (T.T. Hebert)Yaegashi & Udagawa was the most sensitive fungus, being blocked almost entirely by 4-chloro derivative even at 20μg/mL, a concentration at which the reference commercial compound tricyclazole was nearly ineffective.Discussion and conclusion: These findings demonstrate that the pyrazolo[3,4-c]isothiazole derivatives have a widespectrum of activity on phytopathogenic and opportunistic fungi. In particular the 4-chloro derivative seems to havea great potential as new product to combat M. grisea in the agricultural field
Increase of body temperature immediately after ovulation in mares
No full textTo successfully inseminate mares, precise detection of ovulation time is crucial, especially when using frozen-thawed semen. Monitoring body temperature, as has been described in women, could be a noninvasive way to detect ovulation. The objective of this study was to investigate the relationship between the time of ovulation and the variation of body temperature in mares based on automatic continuous measurements during estrus. The experimental group included 21 mares for 70 analyzed estrous cycles. When the mares showed estrous behavior, they were administered intramuscular deslorelin acetate (2.25 mg) in the evening. At the same time, monitoring of body temperature using a sensor device fixed at the left lateral thorax was started and continued for over 60 hours. In 2-hour intervals, transrectal ultrasonography was performed to detect ovulation. Estimated body temperature in the 6 hours following ovulation detection was on average 0.06°C +/- 0.05°C (mean +/- SD) significantly higher when compared with body temperature at the same time on the preceding day (P = .01). In addition, a significant effect of PGF2α administration for estrus induction on the body temperature was found, being significantly higher until 6 hours before ovulation compared to that of uninduced cycles (P = .005). In conclusion, changes in body temperature during estrus in mares were related to ovulation. The increase in body temperature immediately after ovulation might be used in the future to establish automatized and noninvasive systems to detect ovulation. However, the identified temperature rise is relatively small on average and hardly identifiable in the individual mares
Increase of skin temperature prior to parturition in mares
No full textPrediction of impending foaling is highly desirable as early intervention may improve mare and foal outcomes. However, monitoring the peripartum mare is a time-consuming challenge for breeders and many foaling prediction systems have limitations. "Heating up" of the mare is empirically used by breeders as a sign of upcoming parturition in mares. The purpose of this study was to investigate if an increase in skin temperature shortly before parturition is detectable and to determine whether such physiological changes could be an additional valuable parameter to predict foaling. For that, 56 foalings of 14 Warmblood mares, 5 Arabian mares, 27 Thoroughbred mares, and 2 mares of other breeds were analyzed in this 2-year-study. Eight mares were monitored in both years. Mares were between 4 and 22 years old (average: 10 ± 5.5 years) and the mean pregnancy length was 342 days (±9 days), resulting in 14 births from primiparous mares and 42 multiparous mares. For monitoring the periparturient mares, the Piavet® system (Piavita AG, Zurich, Switzerland) was fixed daily when the mares had returned from the field between 4:00 and 6:00 p.m. and collected the next morning between 6:30 and 7:30 a.m. until the time of foaling. Nocturnal rhythms of the skin temperature with the highest values at the start of measurements and a nadir at 6:00 a.m. were observed. On the foaling night, we found a rise in skin temperature starting on average around 90 min prepartum. Skin temperatures recorded at 50 min before parturition and at each 5 min time point until rupture of the allantochorion were significantly higher (p < 0.05) than the mean temperatures measured in the 5 nights before parturition at the same time, reaching a difference of approximately 0.5 °C. There was a significant effect of parity (p = 0.04) on skin temperature during the last hours before foaling where primiparous mares showed a higher mean temperature than uni- or pluriparous mares as early as from 180 min on before parturition. In conclusion, our study shows an increase in skin temperature in most mares within 90 min before birth. Using new biomechanical and digital technologies, this finding could generate an additional potential parameter for the detection of impending parturition. However, skin temperature cannot be used as the only predictive diagnostic of impending parturition in the absence of other parameters
Genetics of lifetime reproductive performance in italian heavy draught horse mares
No full textOur aims were to find a phenotypic variable to express mares’ lifetime reproductive performance after 6 breeding seasons (BS) in Italian Heavy Draught Horse breed (IHDH), and to estimate its heritability. At first, 1487 mares in a training dataset were used to implement and validate a set of predictive coefficients (LFR-C) or equations (LFR-E) to estimate a lifetime foaling rate (LFR) after 6 BS, i.e., the number of foals generated divided by the opportunities to do so. Then, 3033 mares in a dataset with at least 3 registered BS, was used to estimate LFR for mares with 3, 4, or 5 registered RS. This dataset contained actual (n = 1950) and estimated (n = 1443) LFR, obtained by LFR-C, and LFR-E; Arcsine transformation of LFR-C and LFR-E were also analyzed in single trait animal models to estimate heritability. Overall, the LFR showed a moderate but significant genetic variation, and the heritability of the trait was high (0.24) considering it is a fitness trait. The arcsine transformation of LFR did not show any improvement of heritability. The present study indicates the possible use of a linear LFR variable for breeding purposes in IHDH breed considering both complete and incomplete reproductive careers
Synthesis of a novel series of imidazo[4,5-c]pyrazole derivatives and their evaluation as herbicidal agents
No full textEver changing problems in agricultural weed control require periodic introduction of new herbicides. Imidazo[4,5-c]pyrazoles, which were considered of interest as potential herbicides, were synthesized and examined for the pre-emergence, post-emergence, and post-transplant control of weeds in rice against broadleaf and grass weed species. The data obtained suggest that some imidazo[4,5-c]pyrazoles have potential herbicidal activity against a wide range of weeds, with 5-methyl, 5-thiomethyl, and 5-unsubstituted derivatives being the most effective. No herbicidal activity was observed in the 5-methylsulfonylimidazo[4,5-c]pyrazole and imidazo[4,5-c]pyrazolone series
Herminio Mares and his grandchildren
No full textBlack & white photograph of Lobatos resident Herminio Mares and his three grandchildren in Lobatos, NM.
He says: "We old ones have a lot of stories, a lot of songs. But these kids would rather watch TV or listen to the radio.They are like kids everywhere"
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