145 research outputs found
Hemodynamics of the corpus luteum in mares during experimentally impaired luteogenesis and partial luteolysis
© 2017 The aim of the current project was to characterize the luteal vascularity and the plasma concentrations of progesterone (P4), prolactin (PRL) and 13,14-dihydro-15-keto-PGF2α (PGFM) in mares with luteal disturbances during early and mid-diestrus. In Experiment 1, twenty-one mares were treated with 2 mL of 0.9% NaCl, or 1 mg Dinoprost, or 10 mg Dinoprost on day two after ovulation (Control-D2, 1/10PGF-D2 and PGF-D2 groups, respectively; n = 7 mares/group). In Experiment 2, similar treatments were performed eight days post-ovulation using a different cohort of 21 mares (Control-D8, 1/10PGF-D8 and PGF-D8 groups, respectively; n = 7 mares/group). Blood samples were collected hourly and power-Doppler examinations of the corpus luteum (CL) were performed every 6 h from H0 (moment immediately before treatment) to H48. Data collection was also done once a day from D0 (day of ovulation) to D20. In Experiment 1, the PGF-D2 and 1/10PGF-D2 groups had lower increase of plasma concentration of P4 until H48 and reduced maximum P4 concentrations on D8-D11 than mares from the Control-D2 group. However, no differences among groups were detected for luteal vascularity during early and mid-diestrus. In Experiment 2, complete and partial luteolysis were detected in mares from the PGF-D8 and 1/10PGF-D8 groups, respectively. Luteal vascularity and plasma P4 concentrations differed among Control-D8, PGF-D8 and 1/10PGF-D8 groups on H48. Partially regressed CLs (1/10PGF-D8 group) generated more Doppler signals than completed regressed CLs (PGF-D8 group) between D10 and D13. In both experiments, a transient increase in PRL activity was observed in parallel to the PGFM pulse in mares receiving 1 or 10 mg Dinoprost. The use of prostaglandin on D2 at conventional or 1/10 of the dose impaired the luteal development in mares. Moreover, the low dose of prostaglandin lead to partial regression of mature CLs. The blood supply was reduced in partially regressed CLs, but not in CLs undergoing impaired luteogenesis
Coherent states of non-relativistic electron in magnetic-solenoid field
We construct coherent states of a nonrelativistic electron in the
magnetic-solenoid field, which is a superposition of the Aharonov-Bohm field
and a collinear uniform magnetic field. In the problem under consideration
there are two kind of coherent states, the first kind corresponds to classical
trajectories which embrace the solenoid and the second one to trajectories
which do not. Mean coordinates in the constructed coherent states are moving
along classical trajectories, the coherent states maintain their form under the
time evolution, and represent a complete set of functions, which can be useful
in semi classical calculations. In the absence of the Aharonov-Bohm filed these
states are reduced to the well-known in the case of uniform magnetic field
Malkin-Man'ko coherent states.Comment: 11 pages, version accepted for publication in J. Phys. A, 3 figures
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Composição da flora arbórea de um trecho de floresta estacional no Jardim Botânico da Universidade Federal de Viçosa (face sudoeste), Viçosa, Minas Gerais
Estrutura fitossociológica da floresta semidecídua de altitude do parque municipal da Grota Funda (Atibaia - estado de São Paulo)
Composição florística da floresta semidecídua de altitude do Parque Municipal da Grota Funda (Atibaia - Estado de São Paulo)
Adubos orgânicos e organominerais como alternativa sustentável para a cultura do milho (Zea mays L.).
Mineral fertilizers, in addition to being costly when misused, can be aggressive to the soil and the environment. For this reason, it is necessary to evaluate other sources of nutrients for plants. For this purpose, the experiment was installed under field conditions, with the objective of evaluating the efficiency of bat guano and organomineral organic fertilizers, resulting from the mixture based on nitrogen, phosphorus and potassium (NPK), in formula-12-24-12, on the development and yield of corn (Zea mays L.), submitted to a completely randomized block design, with 4 treatments and 4 repetitions. The treatments were mineral fertilizer (NPK, 12-24-12), bat guano, organomineral (NPK and bat guano), and the control. The results show that the bat guano provided the greatest increase in plant height and number of grains, while the largest increments in stem diameter, number of leaves, cob weight, grain weight, and higher yield, were obtained by the organomineral. These results have been achieved, despite the fact that organic fertilizers have low concentrations of NPK, when complemented with mineral fertilization, they promote positive effects on plants, since they make better use of nutrients through the timing of release throughout their development. It was concluded that organic and organomineral fertilizers can be used as a sustainable alternative to increase yields in the corn crop in replacement of mineral fertilizers.Los fertilizantes minerales, además de ser costosos cuando se usan incorrectamente, pueden ser agresivos para el suelo y el medio ambiente. Por esta razón, es necesario evaluar otras fuentes de nutrientes para las plantas. Para este propósito, el experimento se instaló en condiciones de campo, con el objetivo de evaluar la eficiencia del guano de murciélago orgánico y los fertilizantes organominerales, como resultado de la mezcla de guano y fertilizante complejo a base de nitrógeno, fósforo y potasio. (NPK), en la fórmula 12-24-12, sobre el desarrollo y rendimiento del cultivo de maíz (Zea mays L.), sometido a un diseño experimental de bloques completos al azar, con 4 tratamientos y 4 repeticiones. Los tratamientos fueron fertilizante mineral (NPK, 24-12-12), guano de murciélago, organomineral y el control. Los resultados muestran que el guano de murciélago proporcionó el mayor aumento en la altura de la planta y el número de granos por mazorca, mientras que los mayores incrementos en el diámetro del tallo, el número de hojas, el peso de la mazorca, el peso del grano, así como un mayor rendimiento por área , fueron obtenidos por el organomineral. Estos resultados se lograron, a pesar del hecho de que los fertilizantes orgánicos tienen bajas concentraciones de NPK, cuando se complementan con la fertilización mineral, promueven efectos positivos en las plantas, ya que hacen un mejor uso de los nutrientes a través del momento de la liberación a lo largo de su desarrollo. Se concluyó que los fertilizantes minerales orgánicos y orgánicos pueden usarse como una alternativa sostenible para aumentar los rendimientos en el cultivo de maíz en reemplazo de los fertilizantes minerales.Os fertilizantes minerais para além de apresentarem custos onerosos, quando mal empregues, podem ser agressivos aos solos e ao meio ambiente. Por este motivo, é necessária a avaliação de outras fontes de nutrientes para as plantas. Para o efeito, foi instalado o experimento em condições de campo, com o objetivo de avaliar a eficiência dos adubos orgânicos a base de guano de morcego e o organomineral, resultante da mistura do guano e do fertilizante complexo a base de nitrogênio, fosforo e potássio (NPK), na fórmula-12-24-12, sobre o desenvolvimento e rendimento da cultura do milho (Zea mays L.), submetidas em desenho experimental de blocos completos casualizados, com 4 tratamentos e 4 repetições. Os tratamentos foram, o adubo mineral (NPK, 12-24-12), o guano de morcego, o organomineral, e a testemunha. Os resultados mostram que o guano de morcego proporcionou maior incremento na altura da planta e número de grãos por espiga, enquanto que os maiores incrementos do diâmetro do caule, número de folhas, peso da espiga, peso dos grãos, assim como maior rendimento por área, foram obtidos pelo organomineral. Estes resultados foram alcançados, apesar dos adubos orgânicos apresentarem baixas concentrações de NPK, quando complementados com adubação mineral, promovem efeitos positivos às plantas, uma vez que estas aproveitam melhor os nutrientes através do sincronismo de liberação ao longo do seu desenvolvimento. Concluiu-se que, os adubos orgânicos e organominerais podem ser utilizados como alternativa sustentável para o aumento dos rendimentos na cultura do milho em substituição dos adubos minerais
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