Genetics of multiple disease resistance in a doubled-haploid population of barley   总被引：1，自引：0，他引：1  

B. J. Steffenson    Y. Jin    B. G. Rossnagel    J. B. Rasmussen  K. Kao 《Plant Breeding》1995,114(1):50-54

The barley accession Q21861 possesses resistance to the stem-rust (Puccinia graminis f.sp. tritici), leaf-rust (P. hordei), and powdery-mildew (Blumeria graminis f.sp. hordei) pathogens. An anther-culture-derived doubled-haploid population was produced from F₁ plants from a cross of this accession and the susceptible breeding line SM89010 as a means of rapidly and efficiently determining the genetics of multiple disease resistance. The doubled-haploid population segregated 1:1 (resistant:susceptible) for resistance to the stem rust pathotype QCC indicating the involvement of a single resistance gene, rpg4. Two-gene (3:1) and one-gene (1:1) segregation ratios were observed for resistance to the stem-rust pathotype MCC at low (23–25°c) and high (27–29°C) temperature, respectively. These different segregation patterns were due to a pathotype × temperature interaction exhibited by rpg4 and Rpg1. another stem-rust-resistance gene present in Q21861. One-gene and two-gene segregation ratios were observed in reaction to the leaf rust and powdery mildew pathogens. These data demonstrate the utility of doubled haploid populations for determining the genetics of multiple disease resistance in barley.  相似文献   

Use of dietary supplements in Denmark is associated with health and former smoking     

Knudsen VK  Rasmussen LB  Haraldsdóttir J  Ovesen L  Bülow I  Knudsen N  Jørgensen T  Laurberg P  Perrild H 《Public health nutrition》2002,5(3):463-468

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Development of vaccination strategies for the management of rabies in African wild dogs     

F. Vial  G. Rasmussen 《Biological conservation》2006,131(2):180-192

The standard objective of a vaccination strategy is to reduce the reproductive ratio, R₀, defined as the number of secondary host infections arising directly from introduction of a single infected individual into an otherwise fully susceptible population, to below 1. This ensures that only very small outbreaks are likely to arise. However, this objective usually requires a high level of vaccination coverage that is often expensive and logistically difficult to achieve. For the purposes of conserving rare species that are threatened by outbreaks of infectious disease, population persistence may be assured by a vaccination strategy designed to suppress only the largest outbreaks of disease that reduce the population to below a minimum viable population size. Such strategies targeting only a viable minimal ‘core’ of the population are likely to be logistically less demanding. Here we explore how these core vaccination strategies might be designed for African wild dogs (Lycaon pictus), an endangered canid species whose remaining populations are threatened by rabies outbreaks. We develop and analyse a population viability model with an explicit epidemiological model embedded within it. The model predicts that core vaccination campaigns, using vaccines that provide two years of immunity, and targets 30-40% of individuals within a population every 1-2 years would be successful in ensuring persistence of small populations, and required coverage levels can be even lower in larger populations. This strategy appears robust to synchronized introduction of rabies into packs, possible Allee effects, and the use of vaccines providing only one year of immunity.  相似文献   

Carbonyl sulfide and carbon disulfide from the eruptions of mount st. Helens     

Rasmussen RA  Khalil MA  Dalluge RW  Penkett SA  Jones B 《Science (New York, N.Y.)》1982,215(4533):665-667

Ash from the massive 18 May 1980 eruption of Mount St. Helens readily gave off large amounts of carbonyl sulfide and carbon disulfide gases at room temperature. These findings suggest that the sulfur that enhances the Junge sulfate layer in the stratosphere after volcanic eruptions could be carried directly to the upper atmosphere as carbonyl sulfide and carbon disulfide adsorbed on ash particles from major volcanic eruptions.  相似文献   

DISPLAYING AND FILING MICROSCOPIC PREPARATIONS     

Rasmussen AT  Fisher CA 《Science (New York, N.Y.)》1930,71(1837):289-290

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Bias in Peer Review of Organic Farming Grant Applications     

Jesper Rasmussen  Vibeke Langer  Hugo Fjelsted Alrøe 《Agriculture and Human Values》2006,23(2):181-188

Peer reviews of 84 organic farming grant applications from Sweden were analyzed to determine whether the reviewers’ affiliation to one of two types of agriculture (i.e., organic and conventional) influenced their reviews. Fifteen reviewers were divided into three groups: (1) scientists with experience in organic farming research; (2) scientists with no experience in organic farming research; and (3) users of organic farming research. The two groups of scientists assessed the societal relevance and scientific quality of the grant applications based on three criteria (i.e., presentation, methodology, qualifications), whereas the user group only assessed societal relevance. The analysis showed that the two groups of scientists provided very different reviews. Scientist reviewers with experience in organic farming research agreed more with the user group on research relevance than did scientist reviewers without such experience, and the assessment of relevance was closely correlated to the assessment of scientific quality within both scientific groups. As both scientific groups did not clearly distinguish between societal relevance and scientific quality, the idea of an objective science is challenged. The contextual values associated with the norms of good agriculture were not clearly distinguished from the constitutive values of science associated with the traditional norms of good science. This raises the question of whether organic and conventional grant applications should be mixed for review regardless of the reviewers.  相似文献   

Poliomyelitis in Monkeys: Decreased Susceptibility after Avoidance Stress     

Marsh JT  Lavender JF  Chang SS  Rasmussen AF 《Science (New York, N.Y.)》1963,140(3574):1414-1415

Eleven monkeys were subjected to avoidance stress for 24 hours followed immediately by intravenous inoculation with type I poliovirus. Twelve control monkeys not so stressed were similarly inoculated. Seven of 11 stressed animals survived the infection while only one of the controls lived and their average incubation period was significantly longer than the average for controls. The number of circulating lymphocytes decreased significantly in experimental animals during and immediately after exposure to stress.  相似文献   

Paleo-Eskimo mtDNA genome reveals matrilineal discontinuity in Greenland     

Gilbert MT  Kivisild T  Grønnow B  Andersen PK  Metspalu E  Reidla M  Tamm E  Axelsson E  Götherström A  Campos PF  Rasmussen M  Metspalu M  Higham TF  Schwenninger JL  Nathan R  De Hoog CJ  Koch A  Møller LN  Andreasen C  Meldgaard M  Villems R  Bendixen C  Willerslev E 《Science (New York, N.Y.)》2008,320(5884):1787-1789

The Paleo-Eskimo Saqqaq and Independence I cultures, documented from archaeological remains in Northern Canada and Greenland, represent the earliest human expansion into the New World's northern extremes. However, their origin and genetic relationship to later cultures are unknown. We sequenced a mitochondrial genome from a Paleo-Eskimo human by using 3400-to 4500-year-old frozen hair excavated from an early Greenlandic Saqqaq settlement. The sample is distinct from modern Native Americans and Neo-Eskimos, falling within haplogroup D2a1, a group previously observed among modern Aleuts and Siberian Sireniki Yuit. This result suggests that the earliest migrants into the New World's northern extremes derived from populations in the Bering Sea area and were not directly related to Native Americans or the later Neo-Eskimos that replaced them.  相似文献   

Atmospheric trends in methylchloroform and the global average for the hydroxyl radical     

Prinn R  Cunnold D  Rasmussen R  Simmonds P  Alyea F  Crawford A  Fraser P  Rosen R 《Science (New York, N.Y.)》1987,238(4829):945-950

Frequent atmospheric measurements of the anthropogenic compound methylchloroform that were made between 1978 and 1985 indicate that this species is continuing to increase significantly around the world. Reaction with the major atmospheric oxidant, the hydroxyl radical (OH), is the principal sink for this species. The observed mean trends for methylchloroform are 4.8, 5.4, 6.4, and 6.9 percent per year at Aldrigole (Ireland) and Cape Meares (Oregon), Ragged Point (Barbados), Point Matatula (American Samoa), and Cape Grim (Tasmania), respectively, from July 1978 to June 1985. These measured trends, combined with knowledge of industrial emissions, were used in an optimal estimation inversion scheme to deduce a globally averaged methylchloroform atmospheric lifetime of 6.3 (+ 1.2, -0.9) years (1sigma uncertainty) and a globally averaged tropospheric hydroxyl radical concentration of (7.7 +/- 1.4) x 10(5) radicals per cubic centimeter (1sigma uncertainty). These 7 years of gas chromatographic measurements, which comprise about 60,000 individual calibrated real-time air analyses, provide the most accurate estimates yet of the trends and lifetime of methylchloroform and of the global average for tropospheric hydroxyl radical levels. Accurate determination of hydroxyl radical levels is crucial to understanding global atmospheric chemical cycles and trends in the levels of trace gases such as methane.  相似文献   

Spin-dependent WIMP limits from a bubble chamber     

Behnke E  Collar JI  Cooper PS  Crum K  Crisler M  Hu M  Levine I  Nakazawa D  Nguyen H  Odom B  Ramberg E  Rasmussen J  Riley N  Sonnenschein A  Szydagis M  Tschirhart R 《Science (New York, N.Y.)》2008,319(5865):933-936

Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF3I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection.  相似文献