Populations of the introduced book trout, Salvelinus fontinalis, have recently become more widespread and abundant in western North American streams, possible at the expense of native Colorado River cutthroat trout, Oncorhynchus clarki pleuriticus. We examined the intensity and potential mechanism of competition between these species. Feeding experiments in laboratory stream channels showed that cutthroat trout feeding efficiency decreases in the presence of a brook trout. Decreased feeding efficiency appeared to be due to interference, as cutthroat trout were inactive in the presence of the brook trout. Evidence for interference competition in the feeding experiments was also given by the fact that brook trout feeding efficiency was lower than the feeding efficiency of cutthroat trout. The decreased feeding efficiency of cutthroat trout in the presence of brook trout was due to decreased attack rates by cutthroat trout, and was not due to attacks and consumption of the food items by the brook trout. A field enclosure experiment, in which riffle-pool sections of a stream were isolated by fencing, was performed to determine if the presence of brook trout had a negative effect on the growth, fat content, and diet of cutthroat trout. Cutthroat trout fat levels were significantly lower in the presence of brook trout. The growth of cutthroat trout was not significantly different in the presence and absence of brook trout, but there was a trend fro lower growth of cutthroat trout in the presence of brook trout. Diet choices and total biomass of prey consumed by cutthroat trout in the field experiment and in a survey of three streams were not affected by the presence of brook trout. The observed decreased feeding efficiency of cutthroat trout in the presence of brook trout may be the mechanism responsible for the significant;y decreased fat levels during the relatively short, summer growing season and may result in reduced population sizes due to high overwinter mortality and delayed sexual maturity.

Venison represents an important resource in this area. The average number of deer killed in Utah during hunting seasons of the ten-year period, 1940 to 1950, was over 50,000 animals annually according to the Utah State Fish and Game Department. For the period from 1950 to 1960 this figure has increased to over 100,000 animals. In terms of dressed weight, 100,000 animals would yield an estimated 8,000,000 pounds of meat. Neighboring states also produce large numbers of deer. This pictures venison not only as an important resource but as one rapidly increasing in importance.

Beans are an important source of carbohydrates, proteins, minerals, and vitamins for millions of vegetarians in the world, especially in Asia. The quality and harvesting time of beans depend upon the purpose for which the beans are used. For example, for canning and freezing the beans should be harvested when they are neither starchy nor watery but should be sugary. The processing industry in Asia is not highly developed. Hence, the food is usually preserved by sun drying. Sun dried beans are often consumed the year around.

The social organization of the vicuna (Vicugna vicugna) and its relationship to the environment were studied at the Pampa Galeras National Vicuna Reserve in southern Peru from May 1968 to April 1971. 2 Behavioral data were collected on groups within a grid of 12.4 km during 3,800 hours of observation. The vicuna's alpine grassland environment was characterized by greatly fluctuating and freezing temperatures, light precipitation, high evaporation, wind, short growing seasons, shallow and infertile soils and low plant production. Vicuna habitat quality was dependent upon high producing, preferred vegetation types and close access to permanent water and a sleeping area. Only one-third of the Reserve was good habitat and less than 20 percent of the Cupitay Valley study area was preferred by feeding vicuna. Territorial behavior has evolved in this environment where food resources are generally in short supply, annually renewed on locally abundant patchy sites, but predictable in time and space and xvi defendable. Nearly 90 percent of females 2 years and older were pregnant at the beginning of the birth season and 90 percent of all births occurred between 22 February and 7 April. Ten to 30 percent of the crias (juveniles) died during their first 4 months. Five social units were distinguished, with the population primarily composed of Male Groups (MGs) and family groups: Permanent Territorial Family Groups (PTFGs) occupied good habitat and Marginal Territorial Family Groups (MrFGs) secondary habitat. Most PTFGs and MrFGs each occupied a year-round feeding territory in the day and a separate sleeping territory at night. Average group size for PTFGs was six (one male, three females and two crias) and they composed about 55 percent of the population. MrFGs were smaller (five), composed 40 percent of the population, had lower reproductive success and spent less time in their feeding territories than PTFGs. Non-territorial MGs averaged 20 animals and were chased out of zones occupied by PTFGs and MrFGs. As the number of groups increased, the frequency and intensity of territorial defense by males also increased. Territories provided a place free from intraspecific interference where females could feed, sleep, mate, give birth and raise their young. Feeding territories averaged 18 ha and sleeping territories 3 ha in size. A small cluster of sleeping territories on the flattened ridge formed a cummunal sleeping area for groups using the adjacent valleys. MGs and MTFGs made greater use of ridges and the non-preferred b1.tt1.ch grass communities, because they were excluded from preferred areas occupied by PTFGs. Group size was significantly (P

Organisms must be able to cope with many natural and anthropogenic stressors in order to successfully survive and reproduce. These stressors can come in many forms and are increasing as anthropogenic activities become more and more prevalent across the globe. In order to cope with these stressors, organisms must allocate limited energy away from processes such as reproduction to mount a stress response. This stress response involves the activation of the hypothalamic-pituitary-adrenal axis and results in a cascade of hormones and down-stream effects, such as changes in reproduction and immune function. In order to understand how reptiles and amphibians cope with a variety of stressors, I conducted seven experiments. I first validated an immune assay which can be employed across vertebrate taxa and can measure functional immune responses. I then analyzed effects of natural stressors (wounding, predator attacks, natural toxins, and food restriction) and/or anthropogenic stressors (restraint and the anthropogenic toxins polybrominated diphenyl ether and indoxacarb) on reptiles and/or amphibians. In measuring many different stressors and several different taxa (the side blotched-lizard, Uta stansburiana, the rough-skinned newt, Taricha granulosa, the wandering gartersnake, Thamnophis elegans, and the common gartersnake, T. sirtalis), I hoped to determine if patterns in energy allocation and trade-offs existed on a broad scale. I found that while there are some similarities among the responses, each organism exposed to different stressors had to be examined separately. This supports the emerging consensus that the stress response is extremely context-dependent and responses seen in one context cannot be inferred to other organisms with disparate life-histories, sexes, geographic range, or previous experience. Because of this, researchers must focus on the population in question to assess physiological questions before making management decisions.

Utah lotus (Lotus utahensis Ottley) is a North American legume related to the Eurasian birdsfoot trefoil (L. corniculatus L.), which is an economically valuable forage legume for pastures. Our objectives were to describe the genetic variation within Utah lotus seed collections by measuring adaptive phenotypic traits at three common garden sites in northern Utah, and to determine the genetic structure of populations and the extent of local adaptation through AFLP (amplified fragment length polymorphisms) analysis. We evaluated 14 Utah lotus seed collections from Nevada and Utah, and five seed collections of scrub lotus (L. wrightii (A. Gray) Greene) from Arizona. Significant variation was observed among collections for all phenotypic traits measured. Spring emergence date, flowering date, survival, dry-matter yield, and canopy width discriminated these two species with 100% accuracy. Population structure estimates from 552 AFLP markers of Utah lotus, scrub lotus, and the birdsfoot trefoil check resulted in five genetically differentiated groups. The three primary groups were the three species; within the Utah lotus collections three sub-groups were identified, which corresponded to geographic locations of the collection sites. Two collections of Utah lotus (LU-5 and LU-20) were among the top-tier collections for important phenotypic traits, including dry-matter yield, pod production, number of stems, canopy height, and survival. No significant Pearson’s correlations or canonical correlations were found among the phenotypic traits and environmental characteristics at the collection sites. Significant correlations were detected between genetic and geographic, and phenotypic and geographic distance matrices (r = 0.888, P = 0.001 and r = 0.235, P = 0.044, respectively). No other significant distance matrix correlations were found. Despite the significant isolation by distance correlation, both the genetic and phenotypic evaluations provide little evidence to support local adaptation. Based on these results, one pooled germplasm source of Utah lotus could be developed for use in rangeland restoration and revegetation of the southern Great Basin. Collections LU-5 and LU-20 would be good candidate collections that would represent minimal risk of maladaptation and out-breeding depression with natural populations.

No description available.

La cycline B est un des régulateurs clef du cycle cellulaire, associée à Cdc2 elle forme<br />le MPF (Maturation Promoting Factor). Ce complexe contrôle la transition entre phases G2 et<br />M du cycle cellulaire. Au laboratoire, un variant d'épissage de la cycline B d'oursin a été<br />découvert. Il lui manque la partie C-terminale, dans laquelle certains résidus sont très<br />conservés.<br />Au cours de ce travail, le même variant a été cloné chez l'étoile de mer. Ses<br />partenaires ont été recherchés par criblage de banque en double hybride chez la levure ainsi<br />qu'en chromatographie d'affinité. Cette dernière technique a permis d'isoler une protéine de<br />15kDa (P15) qui s'associe à la cycline B même en l'absence de Cdc2. Une particularité de<br />cette protéine est d'exister sous trois formes alléliques. La P15 est localisée au niveau du<br />fuseau de division. Des exprériences de micro-injections ont montré qu'elle joue un rôle dans<br />la sortie de méiose, vraisemblablement en liaison avec la dégradation de la cycline B.<br />Parallèlement, le rôle des résidus manquant chez le variant d'épissage a été étudié par<br />la mutagénèse du C-terminal de Clb2 de levure. Ces résidus sont importants pour la<br />localisation de la cycline mais aussi pour son association correcte avec Cdc2.

sans résumé

No description available.