2,042 research outputs found
An Engineered Nonsense \u3cem\u3eURA3\u3c/em\u3e Allele Provides a Versatile System to Detect the Presence, Absence and Appearance of the [em\u3ePSI\u3c/em\u3e\u3csup\u3e+\u3c/sup\u3e] Prion in \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e
Common methods to identify yeast cells containing the prion form of the Sup35 translation termination factor, [PSI+], involve a nonsense suppressor phenotype. Decreased function of Sup35p in [PSI+] cells leads to readthrough of certain nonsense mutations in a few auxotrophic markers, for example, ade1-14. This readthrough results in growth on adenine deficient media. While this powerful tool has dramatically facilitated the study of [PSI+], it is limited to a narrow range of laboratory strains and cannot easily be used to screen for cells that have lost the [PSI+] prion. Therefore we have engineered a nonsense mutation in the widely used URA3 gene, termed the ura3-14 allele. Introduction of the ura3-14 allele into an array of genetic backgrounds, carrying a loss-of-function URA3 mutation and [PSI+], allows for growth on media lacking uracil, indicative of decreased translational termination efficiency. This ura3-14 allele is able to distinguish various forms of the [PSI+] prion, called variants and is able to detect the de novo appearance of [PSI+] in strains carrying the prion form of Rnq1p, [PIN+]. Furthermore, 5-fluoorotic acid, which kills cells making functional Ura3p, provides a means to select for [psi−] derivatives in a population of [PSI+] cells marked with the ura3-14 allele, making this system much more versatile than previous methods
Geomorphologic evolution of a rapidly deteriorating barrier island system with multiple sediment sources: Eastern Isles Dernieres, Louisiana, 1887 to 2006
Trinity, East, and Wine Islands make up the eastern half of the Isles Dernieres barrier arc in south-central Louisiana. Formed following the abandonment of the Lafourche delta complex, subsidence and storm erosion have led to rapid deterioration of the system. Since 1887, the land area of the islands has decreased seventy-seven percent, and the gulf shoreline has retreated landward more than a kilometer. Wave ravinement on the shoreface of the islands is responsible for the most sediment loss; liberated sediment travels longshore to tidal inlets. The dominant ebb tidal currents then transport the sediment to where it is deposited in ebb tidal deltas or carried to the west, out of the system. A large lobe of sediment bypassing Cat Island Pass is entering the system from the eastern lower shoreface, which helps replace some of the sediment lost through wave ravinement to the upper shoreface
Geomorphologic evolution of a rapidly deteriorating barrier island system with multiple sediment sources: Eastern Isles Dernieres, Louisiana, 1887 to 2006
Trinity, East, and Wine Islands make up the eastern half of the Isles Dernieres barrier arc in south-central Louisiana. Formed following the abandonment of the Lafourche delta complex, subsidence and storm erosion have led to rapid deterioration of the system. Since 1887, the land area of the islands has decreased seventy-seven percent, and the gulf shoreline has retreated landward more than a kilometer. Wave ravinement on the shoreface of the islands is responsible for the most sediment loss; liberated sediment travels longshore to tidal inlets. The dominant ebb tidal currents then transport the sediment to where it is deposited in ebb tidal deltas or carried to the west, out of the system. A large lobe of sediment bypassing Cat Island Pass is entering the system from the eastern lower shoreface, which helps replace some of the sediment lost through wave ravinement to the upper shoreface
Coccidioidomycosis: a reemerging infectious disease.
Coccidioides immitis, the primary pathogenic fungus that causes coccidioidomycosis, is most commonly found in the deserts of the southwestern United States and Central and South America. During the early 1990s, the incidence of coccidioidomycosis in California increased dramatically. Even though most infections are subclinical or self-limited, the outbreak is estimated to have cost more than $66 million in direct medical expenses and time lost from work in Kern County, California, alone. In addition to the financial loss, this pathogen causes serious and life-threatening disseminated infections, especially among the immunosuppressed, including AIDS patients. This article discusses factors that may be responsible for the increased incidence of coccidioidomycosis (e.g., climatic and demographic changes and the clinical problems of coccidioidomycosis in the immunocompromised) and new approaches to therapy and prevention
Determination of Interface Atomic Structure and Its Impact on Spin Transport Using Z-Contrast Microscopy and Density-Functional Theory
We combine Z-contrast scanning transmission electron microscopy with
density-functional-theory calculations to determine the atomic structure of the
Fe/AlGaAs interface in spin-polarized light-emitting diodes. A 44% increase in
spin-injection efficiency occurs after a low-temperature anneal, which produces
an ordered, coherent interface consisting of a single atomic plane of
alternating Fe and As atoms. First-principles transport calculations indicate
that the increase in spin-injection efficiency is due to the abruptness and
coherency of the annealed interface.Comment: 16 pages (including cover), 4 figure
Canola: A New Cash Crop for Kentucky
For the past few years, Kentucky farmers have become more interested in alternative cash crops for their farming operations. One such crop that is starting to receive attention is Canola. Classified as an oil crop, Canola is a type of oilseed rape. Rape is a member of the mustard family and is closely related to turnip. cabbage, cauliflower, broccoli and mustards. It is a cool-season annual and an important oilseed crop in many parts of the world that is used for both human consumption and industrial purposes. Major rapeseed production areas are in Europe and Canada. The seed contains approximately 40- 45% oil content (dry basis) and 35% protein (oil-free dry basis). Two products are made from processed rapeseed; an oil that has industrial or edible uses and a high protein meal which can be used in animal feed. There are two types of rape. One type is used for industrial purposes and sometimes called industrial rape. The other is Canola which is used for human and animal consumption. The oil from the varieties of industrial rape contains a high amount of erucic acid (50% or more) and is not suitable for human or animal consumption. It is used in the rubber industry, textiles, detergents, leather, plastics and special lubricants. The meal from these varieties contains high levels of glucosinolates which make it unsuitable for livestock consumption.
The current Canola varieties were made possible by breeding improvements which greatly reduced the undesirable components in rapeseed (erucic acid and glucosinolates) and made it suitable for human and animal consumption. The name given to this type of rapeseed is Canola , which is an international registered trademark of the Canola Council of Canada and the name used to identify the modern rapeseed varieties known as double low with 2% or less erucic acid content and less than 30 micromoles of glucosinolates per gram of oil-free meal. One of the strong selling points for Canola oil is its very low saturated fat level and favorable mixture of mono-and polyunsaturated fats. Like other vegetable oils, it contains no cholesterol. Many feel the edible rapeseed oil market will improve as new vegetable oil products made from rapeseed continue to be developed. In addition, there are strong foreign markets, particularly in Europe and Japan, with demand on the increase. The Canola meal is 35% protein and has an economic worth of about 703 the value of soybean meal (44% protein). The value of the meal is also limited by its high fiber and low lysine content
Demonstration of Cross-Reactive Antibodies to Smooth Gram-Negative Bacteria in Antiserum to Escherichia coli J5
We investigated the discrepancy between the broad cross-protection against gram-negative infections afforded by antiserum to Escherichia coli J5 and its apparently narrow cross-reactivity in vitro. Rabbits immunized with J5 bacteria produced antibodies to both the J5 lipopolysaccharide (LPS; titer by ELISA, 1:60,000) and LPS from the Re mutant of Salmonella minnesota (i.e., to the ketodeoxyoctonate [KDO] and lipid A determinants; titer, 1:3,200). In highly diluted antiserum, titers of antibody to J5 LPS were reduced by 28%-41% after adsorption with seven strains of smooth gram-negative bacteria and by only 4% after adsorption with the Re mutant. Smooth gram-negative bacteria adsorbed virtually all antibody to Re LPS. Therefore, rabbit antiserum to J5 contains type-specific antibodies to core determinants distal to KDO that can obscure highly cross-reactive antibodies to lipid A-KDO in vitro. Cross-reactive antibodies are demonstrable by adsorption with whole bacteria at limiting concentrations of antibod
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