NADP regulates the yeast GAL induction system     

Kumar PR  Yu Y  Sternglanz R  Johnston SA  Joshua-Tor L 《Science (New York, N.Y.)》2008,319(5866):1090-1092

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Transcribing RNA polymerase II is phosphorylated at CTD residue serine-7     

Chapman RD  Heidemann M  Albert TK  Mailhammer R  Flatley A  Meisterernst M  Kremmer E  Eick D 《Science (New York, N.Y.)》2007,318(5857):1780-1782

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A 160,000-year record of dune development and atmospheric circulation in Southern Arabia     

Preusser F  Radies D  Matter A 《Science (New York, N.Y.)》2002,296(5575):2018-2020

Aeolian deposits in the Wahiba Sands, Sultanate of Oman, reveal patterns of atmospheric circulation over the past 160,000 years. Luminescence dating indicates a correlation of dune activity with periods of low global sea level and decreased monsoon intensity. Evidence from dune orientation and sedimentary structures shows exclusively northbound transport of sand during times of high- latitude glaciation. These results are in contrast to the current paleocirculation model that assumes an increase of northwesterly winds because of a southward shift of the Intertropical Convergence Zone. Our results indicate that the circulation pattern during glacial times was comparable to that of the present.  相似文献   

Trichinella pseudospiralis in pig from Croatia     

Relja Beck  Ana Beck  Snježana Lučinger  Tihomir Florijančić  Ivica Bošković  Albert Marinculić 《Veterinary parasitology》2009,159(3-4):304-307

Trichinella spiralis and Trichinella britovi are species that are frequently found in domestic pigs and various sylvatic animals in Croatia. During routine trichinoscopy, non-encapsulated larvae were detected in the muscle tissue of a domestic pig. Artificial digestion revealed a larvae burden of 602 muscle larvae per gram of tissue. Tissue section analysis confirmed the presence of non-encapsulated larvae. Multiplex PCR identified the larvae as T. pseudospiralis. This observation is consistent with the reports of a local veterinary inspector who described the presence of non-encapsulated Trichinella in four individual cases over the last 2 years. This is the first report of T. pseudospiralis in Croatia and one of very few cases of T. pseudospiralis infection described in domestic pigs. The detection of non-encapsulated larvae stresses the need for implementation of artificial digestion instead of trichinoscopy for the detection and identification of Trichinella infections.  相似文献   

Chemical form of selenium in naturally selenium-rich lentils (Lens culinaris L.) from Saskatchewan     

Thavarajah D  Vandenberg A  George GN  Pickering IJ 《Journal of agricultural and food chemistry》2007,55(18):7337-7341

Lentils (Lens culinaris L.) are a source of many essential dietary components and trace elements for human health. In this study we show that lentils grown in the Canadian prairies are additionally enriched in selenium, an essential micronutrient needed for general well-being, including a healthy immune system and protection against cancer. Selenium K near-edge X-ray absorption spectroscopy (XAS) has been used to examine the selenium biochemistry of two lentil cultivars grown in various locations in Saskatchewan, Canada. We observe significant variations in total selenium concentration with geographic location and cultivar; however, almost all the selenium (86-95%) in these field-grown lentils is present as organic selenium modeled as selenomethionine with a small component (5-14%) as selenate. As the toxicities of certain forms of arsenic and selenium are antagonistic, selenium-rich lentils may have a pivotal role to play in alleviating the chronic arsenic poisoning in Bangladesh.  相似文献   

Detection of the first larval feeding in Crassostrea gigas, using the epifluorescence microscope     

Albert Lucas  Carlos Rangel 《Aquaculture (Amsterdam, Netherlands)》1983,30(1-4):369-374

The first larval feeding in Crassostrea gigas, detected by epifluorescence microscope, occurred 24 h after fertilization at 24°C and 30 h at 21°C. The amount of algal cells (Pavlova lutheri and Isochrysis galbana) necessary to have larvae with filled stomachs was estimated to be 800 cells per day at 24°C and 400 cells per day at 21°C.  相似文献   

Algal biomass accrual in relation to nutrient availability and limitation along a longitudinal gradient of a karst riverine system   总被引：1，自引：0，他引：1  

Penick  Mary D  Grubbs  Scott A  Meier  Albert J 《International Aquatic Research》2012,4(1):1-13

Textural property of surimi products is a prime factor in determining the acceptability of consumer as well as market value. Gelatin is one of the most popular biopolymers widely used in food industry as gelling agent with the unique textural properties. Therefore, the addition of gelatin along with the use of protein cross-linkers could be a means to modify the texture of surimi gel, which can fit the demand of consumers. Surimi from the threadfin bream (Nemipterus bleekeri) was added with bovine gelatin (BG) and bovine/fish gelatin mix (BFGM; 1:1, 2:1, 1:2, 4:1, and 1:4) at 10% protein substitution in combination with and without microbial transglutaminase (MTGase) at 1.2 units/g surimi. Textural properties, whiteness, expressible moisture content, protein pattern, and microstructure and sensory properties of gels were determined. When MTGase at 1.2 units/g surimi was incorporated, the increases in breaking force and deformation were noticeable in both surimi gels, with and without 10% BG added ( p < 0.05). On the other hand, surimi gels added with BFGM at all bovine/fish gelatin ratios had the higher breaking force and deformation, compared with that added with BG, when MTGase was incorporated. Addition of BG or BFGM lowered the expressible moisture content and whiteness of surimi gel ( p < 0.05). Based on SDS-PAGE, band intensity of myosin heavy chain and actin of surimi gel decreased when surimi gel was added with all gelatins, regardless of MTGase addition. The microstructure study revealed that surimi gel network became finer and denser with the addition of MTGase (1.2 units/g surimi), but the coarser and irregular structure was obtained when gelatin was incorporated. Gelatin, especially bovine/fish gelatin mix, at an appropriate level could be used as the protein additive in surumi gel in conjunction with MTGase in order to improve the textural and nutritive properties of the products.  相似文献   

Energy acquisition and allocation to egg production in relation to fish reproductive strategies          下载免费PDF全文

Richard S McBride  Stylianos Somarakis  Gary R Fitzhugh  Anu Albert  Nathalia A Yaragina  Mark J Wuenschel  Alexandre Alonso‐Fernández  Gualtiero Basilone 《Fish and Fisheries》2015,16(1):23-57

Oogenesis in fishes follows a universal plan; yet, due to differences in the synchrony and rate of egg development, spawning frequency varies from daily to once in a lifetime. Some species spawn and feed in separate areas, during different seasons, by storing energy and drawing on it later for reproduction (i.e. capital breeding). Other species spawn using energy acquired locally, throughout a prolonged spawning season, allocating energy directly to reproduction (i.e. income breeding). Capital breeders tend to ovulate all at once and are more likely to be distributed at boreal latitudes. Income breeding allows small fish to overcome allometric constraints on egg production. Income breeders can recover more quickly when good‐feeding conditions are re‐established, which is a benefit to adults regarding bet‐hedging spawning strategies. Many species exhibit mixed capital‐ and income‐breeding patterns. An individual's position along this capital–income continuum may shift with ontogeny or in relation to environmental conditions, so breeding patterns are a conditional reproductive strategy. Poor‐feeding environments can lead to delayed maturation, skipped spawning, fewer spawning events per season or fewer eggs produced per event. In a few cases, variations in feeding environments appear to affect recruitment variability. These flexible processes of energy acquisition and allocation allow females to prioritize their own condition over their propagules' condition at any given spawning opportunity, thereby investing energy cautiously to maximize lifetime reproductive value. These findings have implications for temporal and spatial sampling designs, for measurement and interpretation of fecundity, and for interpreting fishery and ecosystem assessments.  相似文献   

Age-independent diameter increment models for mixed mountain forests     

Ciceu  Albert  Bronisz  Karol  Garcia-Duro  Juan  Badea  Ovidiu 《European Journal of Forest Research》2022,141(5):781-800

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