Search results for "Estro."
showing 10 items of 770 documents
Los materiales didácticos, puente entre la teoría y la práctica
2000
Los planteamientos que defendemos consideran que en la Formación de los Maestros no pueden estar desligadas la teoría de la práctica. Una metodología de investigación-acción que permitiera establecer vínculos entre ellas exigiría situaciones de trabajo en el aula incorporadas de forma cotidiana en el Curriculum de su Formación. Nuestra propuesta de formación pasa por la elaboración de unos materiales de uso interdisciplinar, que ayuden al alumnado y al profesorado a paliar esa deficiencia y nos permitan reflexionar sobre la práctica desde unos planteamientos teóricos concretos que son los que pretendemos enseñar. We defend the approaches considered in the training of teachers can not be det…
Medium-term dynamics of element concentrations in a sparid fish and its isopod parasite after the Prestige oil-spill: Shifting baselines?
2019
Historically, the European Atlantic is probably the most important oil-spill hotspot worldwide. One of the most recent accidents occurred in 2002 when the oil-tanker Prestige sank over the Galician Bank causing two major oil-spills followed by several small leaks until March 2003. This resulted in contamination of virtually all types of marine habitat. Considering that parasites have proved to be good effect and accumulation bioindicators, the present study addresses the medium-term changes in trace element content after the Prestige oil-spill in a model host-parasite system, the bogue, Boops boops (Sparidae) and the isopod Ceratothoa oestroides. To our knowledge, this study is the first to…
Evaluation of biodegradation of nonylphenol ethoxylate and lignin by combining toxicity assessment and chemical characterization.
2009
Abstract The aerobic biodegradation of commercial nonylphenol ethoxylate (NPE) mixture and alkali lignin was studied using the OECD headspace test accompanied by the simultaneous measurement of ecotoxicity directly from the biodegradation liquors and by the follow-up of the chemical composition of the studied chemicals. NPE degradation was dependent on the inoculum source: approximately 40% of NPE was mineralized into CO2 during the 4-week experiment when inoculum from Helsinki City wastewater treatment plant (WWTP) was used, and only 12% was mineralized when inoculum from Jyvaskyla City WWTP was used. Chemical analyses revealed a shift in the ethoxylate chain length from longer to shorter …
La casa del obispo de Tortosa, Alfonso de Aragón. Un palacio valenciano en la encrucijada entre dos siglos (XV-XVI)
2004
El presente artículo analiza, a partir de la documentación, el palacio del obispo de Tortosa don Alfonso de Aragón, edificado en la calle Caballeros de la ciudad de Valencia en el quicio de los siglos XV al XVI. Las obras incluyen la remodelación de las fachadas y la escalera del patio, asi como la decoración de las salas interiores con una de las más tempranas muestras de motivos "a la romana". (A)
Una nota a la correspondencia de Valera: la fuente griega de una estrofa alemana citada por don Juan
1984
El 16 de enero de 1893, don Juan Valera, que acababa de sufrir un desaire urdido contra él por altos dignatarios de la diplomacia vaticana', era nombrado embajador en Viena. El 27 de febrero tomaba posesión, y el 21 de marzo presentaba sus credenciales ante S. M. Imperial. Unos meses después, el 29 de julio, escribe al dramaturgo Tamayo y Baus, refiriéndole, con todo lujo de detalles, los pormenores de la vida vienesa en sus vertientes frivola y social.
Predictive variables of in vitro fertilization and pre-implantation embryo development in the mouse
2002
The present study aims to analyze the cause-effect relationships among several in-vitro fertilization and pre-implantation embryo development variables in the mouse. Superovulation of hybrid (C57Bl/6JIco female X CBA/JIco male) female mice of 4-6 weeks of age was induced by a priming injection of pregnant mare's serum gonadotropin at the estrus stage of the estrous cycle followed after a 48-hr interval by human chrorionic gonadotropin. Ovulated cumulus-enclosed oocytes were inseminated with sperm from hybrid males of 12-16 weeks of age. The multiple linear regression analyses performed indicated that (a) total number of ovulated oocytes is a good predictor of both fertilization frequency an…
Variable mode of estrus affects female decision for multiple mating
2011
Investigating patterns of variation in mating strategies may shed light on their evolutionary importance as well as their impact on the strength and shape of sexual selection. Multimale mating (polyandry) and mate choice are intensely studied subjects in the area of sexual selection, but little is known about intraspecific patterns of variation that may respond to dynamic cost-benefit balances. In a laboratory study, we investigated the mating behavior of female bank voles (Myodes glareolus) with distinctly different time and energy budgets: They were either in cycling estrus (CE) or postpartum estrus (PPE) shortly after delivery. Postpartum mating is highly constrained by time and energy d…
Stage of the estrous cycle at the time of pregnant mare's serum gonadotropin injection affects the quality of ovulated oocytes in the mouse
2002
The present study aims to analyze the effect of the stage of the estrous cycle at the time of pregnant mare's serum gonadotropin (PMSG) injection on number and quality of mouse oocytes retrieved from oviducts after exogenous ovarian stimulation. Cellular and morphological traits of ovulated oocytes from hybrid (C57Bl/6JIco female X CBA/JIco male) female mice of 12, 40-42, 50-52 or 57-62 weeks of age were analyzed. Superovulation was induced by a priming injection of PMSG at different stages of the estrous cycle followed after a 48-hr interval by human chrorionic gonadotropin. Injection of PMSG at diestrus-1 was associated with: (1) increased percentage of cumulus-free oocytes; (2) raised to…
Stage of the estrous cycle at the time of pregnant mare's serum gonadotropin injection affects pre-implantation embryo development in vitro in the mo…
2002
The present study aims to analyze in the mouse the effect of the stage of the estrous cycle at the time of pregnant mare's serum gonadotropin (PMSG) injection on fertilization of ovulated cumulus-enclosed oocytes and later embryo development in vitro to the blastocyst stage. Quality of blastocysts was evaluated by staining and counting of total number of nuclei, mitotic index, percentage of apoptotic nuclei, and cell allocation to the inner cell mass (ICM) and trophectoderm (TE) lineage. Superovulation of hybrid (C57Bl/6JIco female x CBA/JIco male) female mice of 4-6 weeks of age was induced by a priming injection of PMSG at different stages of the estrous cycle followed after a 48-hr inter…
Synchronization protocols in Spanish Merino sheep Reduction in time to estrus by the addition of eCG to a progesterone-based estrus synchronization p…
2015
Abstract An appropriate management of reproduction allows ewes to breed at a more intensive rhythm, more compatible with economic efficiency of farms. Hence, the objectives of the present work were to evaluate a traditional estrus synchronization protocol (based on medroxyprogesterone acetate-impregnated intravaginal sponges combined or not with equine chorionic gonadotropin) on a Merino sheep herd during the breeding season, in order to determine the best working protocol for this breed. A total of 277 sheep, blocked by age (200 ewes and 77 ewe lambs) were randomly allocated to four groups, two of ewes (E and Ee) and two of ewe lambs (L and Le). All females received 60 mg MAP (medroxyproge…