6 resultados para Termination of pregnancy

em Aquatic Commons


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Operational modifications based on recreational angler activity patterns can be successfully formulated to increase creel survey efficiency without a significant loss of information. This study was conducted to estimate the amount of Texas marine sport-boat angler interview and retained fish data (bay and Gulf) that would be missed both coastwide and within each bay system if surveys were terminated early when no angler interviews were conducted by a specified time. Using this method, <3 percent of the total interviews and retained fish would be missed coastwide by terminating surveys at 1400 hours on weekends and 1600 hours on weekdays throughout the survey year. This would result in the early termination of 14 percent of the weekend surveys and 23 percent of the weekday surveys, thus allowing an annual redirection of 440 work-hours and $6,063 in operating expenses.

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EXTRACT (SEE PDF FOR FULL ABSTRACT): Pluvial Lake Estancia in central New Mexico experienced large and rapid fluctuations in surface area and elevation during the build-up to and termination of the last glacial maximum (LGM). Due to continuous groundwater discharge, a minimum pool covering about 400 square kilometers was maintained in the central basin until about 12,000 years ago, ensuring a continuous depositional sequence even during low stands of the lake. ... The sensitive response to fluctuations in climate by several independent proxies at Estancia show that transport of Pacific moisture over western North America changed dramatically during the last Ice Age, perhaps comparable to the large and rapid changes in climate documented from high-latitude ice and North Atlantic marine sediments for the LCM and its transitions.

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The Third International Symposium on Fish Otolith Research and Application in Townsville, Australia, from 11 to 16 July 2004, gathered around 300 scientists from 30 nations (http://www.otolith2004.com). Mayor topics were: structure of otoliths and function; micro-Chemitry and composition; determination of age and growth and their validation; de-termination of age in fish from tropical habitats; influence of climate, ecology and population biology; statistik and modelling; stock assessment and fishery management; quality control in institutions carrying out age determinations, and data processing; and development of technologies. The symposium was preceeded by a workshop at the James Cook University, Townsville, to enhance the knowledge and skill of participants in theoretrical and practical aspects for prearation of otoliths and interpretation of annuli; difficulties in interpreting age in tropical fish; daily increments as well as shape and image analysis.

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A cruise of the R. V. Capricorne in May 1973, in inner part of the gulf of Guinea, allowed the authors to identify the main part of the Atlantic circulation at the longitude of 5 degrees E, between 4 degrees N and 4 degrees S. It gave new data on the termination of the equatorial undercurrent. At the equator, under the westward south equatorial current flows the Atlantic equatorial undercurrent with a maximum eastward velocity of 90 cm/sec at 30 m depth linked to a salinity maximum higher than 36.20 ppt. Below the equatorial undercurrent, about 80-100 m depth, flows a westward current with a velocity as high as 30 cm/sec. At 4 degrees S, the south equatorial countercurrent is well delineated by a high salinity core (more than 36.10 ppt) at 30 m depth with an eastward velocity core of 40 cm/sec. On the contrary, near 3 degrees 30N, a high salinity core (36.10 ppt) flows westwards with a speed of 40 cm/sec at 40 m depth: it is the "return flow" of the undercurrent (Hisard and Moliere 1974). At 4 degrees N the Guinea current carries eastwards surface salinities of 34.50 ppt at 40 cm/sec. Off Cape Lopez (0 degrees 35'S-8 degrees 42'E) the high salinity core of the undercurrent becomes wider near the shore. It is 25m wide offshore, and 70 m wide near the cape. A part of undercurrent water extends northwards, then flows westwards with the subsurface westward circulation in the inner part of the Gulf of Guinea. Another part flows south-southwestwards in a high salinity tongue along the African coast to 4 degrees S. South-west of Cape Lopez, the trades divergence contributes to an upwelling of cold and high salinity water; this water increases at the Cape Lopez front.

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There have been numerous studies on various mammalian species regarding vascular changes in uterine arteries elucidating the effects of parity. In equids, vascular changes of uterine arteries have been demonstrated to occur in uniparous and multiparous mares. The severity of these arteriole changes suggests a link to previous pregnancies. Differences in the number or range of pregnancies can be ascertained through microscopic evaluation of elastin deposition in the arterioles, perivascular fibrosis, and stromal cellularity. There has been little, if any, work performed on parity in the bottlenose dolphin (Tursiops truncatus). The objective of this preliminary study was to determine the feasibility of detecting similar vascular changes in the endometrium of known-aged female bottlenose dolphins to assess parity. Archived formalin fixed samples of uterus were obtained from nine bottlenose dolphins with known age and parity. Four slides were made from each sample and individually stained with four different techniques. From our small sample pool, it appears that uteri from nulliparous animals do not develop perivascular fibrosis. Parous uteri developed perivascular fibrosis and arteriolar elastosis. These changes agree with our expectations that some degeneration (elastosis) and compensation (fibrosis) occurs as a result of uterine expansion of pregnancy. The assessment of this technique for use in bottlenose dolphins would provide an important tool in the determination of the reproductive success of dolphin populations, identify individuals who are sexually mature but nulliparous, which could indicate reproductive dysfunction or increased calving intervals, and increase our knowledge on the role contaminants play in reproductive dysfunction.

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Coral bleaching is a significant contributor to the worldwide degradation of coral reefs and is indicative of the termination of symbiosis between the coral host and its symbiotic algae (dinoflagellate; Symbiodinium sp. complex), usually by expulsion or xenophagy (symbiophagy) of its dinoflagellates. Herein, we provide evidence that during the earliest stages of environmentally induced bleaching, heat stress and light stress generate distinctly different pathomorphological changes in the chloroplasts, while a combined heat- and light-stress exposure induces both pathomorphologies; suggesting that these stressors act on the dinoflagellate by different mechanisms. Within the first 48 hours of a heat stress (32°C) under low-light conditions, heat stress induced decomposition of thylakoid structures before observation of extensive oxidative damage; thus it is the disorganization of the thylakoids that creates the conditions allowing photo-oxidative-stress. Conversely, during the first 48 hours of a light stress (2007 µmoles m−2 s−1 PAR) at 25°C, condensation or fusion of multiple thylakoid lamellae occurred coincidently with levels of oxidative damage products, implying that photo-oxidative stress causes the structural membrane damage within the chloroplasts. Exposure to combined heat- and light-stresses induced both pathomorphologies, confirming that these stressors acted on the dinoflagellate via different mechanisms. Within 72 hours of exposure to heat and/or light stresses, homeostatic processes (e.g., heat-shock protein and anti-oxidant enzyme response) were evident in the remaining intact dinoflagellates, regardless of the initiating stressor. Understanding the sequence of events during bleaching when triggered by different environmental stressors is important for predicting both severity and consequences of coral bleaching