NEW DISCOVERIES AT BAOUSSE ROUSSE,NEAR MENTONE     

DE Nadaillay M 《Science (New York, N.Y.)》1892,20(503):170-171

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THE WAR WITH THE MICROBES     

DE Schweinitz EA 《Science (New York, N.Y.)》1897,5(119):561-570

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Oral vaccination of chickens against Newcastle disease with V4 vaccine delivered on processed rice grains     

GWL JAYAWARDANE  MCL DE  ALWTS DAWWDA BANDARA 《Australian veterinary journal》1990,67(10):364-366

An international effort (sponsored by the Australian Centre for International Agricultural Research) is being made to develop oral vaccines that will protect village chickens against Newcastle disease. The vaccines being used are derivatives of the avirulent Australian V4 strain that have been selected for enhanced heat resistance. The present study, undertaken in Sri Lanka, used local processed (parboiled) rice as a vehicle for the vaccine. Chickens receiving two doses of vaccine on cooked, parboiled rice were completely protected against contact challenge with the virulent SL 88/1 Sri Lankan strain of Newcastle disease virus Chickens kept in contact with these vaccinated chickens were similarly protected. Lower levels of protection were achieved with vaccine given on uncooked parboiled rice. V4 vaccine administered intranasally also gave complete protection. Serums from vaccinated chickens that survived challenge were tested for haemagglutination-inhibition antibodies, using both vaccine virus and challenge virus as antigens. Titres were higher against vaccine virus.  相似文献   

Crosses Involving W. Rimpau's Triticale     

R. Franke 《Plant Breeding》1991,107(4):303-308

One hundred years after the creation of the first true triticale crosses of Rimpau , several recent cultivars of triticale and rye have been crossed with two of them. Recombinants of the awned type of Rimpau 's triticale (10) with ‘Grado’, ‘Lasko’ and ‘Otello’ exhibited a prolonged vegetative period, a shorter straw, an improved lodging resistance, good yielding capacity and higher disease resistance as compared to ‘Lasko’.  相似文献   

Heat Transfer Performance of Ethanol Tree-Dimensional Inner Micro-Fin Heat Pipe     

DE Jun  XIN Ming dao 《保鲜与加工》2003,(4):115-117

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SOIL STRUCTURE IN VERTISOLS OF THE BLUE NILE CLAY PLAINS, SUDAN     

J. H. DE  VOS t. N. C. K. J. VIRGO 《European Journal of Soil Science》1969,20(1):189-206

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Developing environmental principles, criteria, indicators and norms for potato production in South Africa through field surveys and modelling     

A.C. Franke  J.M. SteynK.S. Ranger  A.J. Haverkort 《Agricultural Systems》2011,104(4):297-306

The sustainability of agricultural production is linked to the environment from which it draws its resources. Potato production in the Sandveld in the South African Western Cape occurs in the Cape Floral Kingdom: a vulnerable and globally significant biodiversity hotspot. A scientific approach defining and monitoring sustainability criteria and indicators is required to improve the sustainability of potato production in such a sensitive area. In this paper we propose principles related to the ecological impact of potato production (nature preservation, water preservation and the minimization of chemical and carbon-dioxide emissions) and their derived criteria related to land clearing, irrigation, emissions, and others. Next we defined calculable and measurable indicators of the efficiency with which resources are used, such as proportion of land cleared, water use by the crop, amount of biocides used, the embodied energy of biocides, and the energy needed for farming operations versus the potato yields obtained. In-depth interviews were held with 14 farmers representing 20% of the total potato production area to obtain the current values of these indicators. These were compared to model outcomes of two main sustainability indicators: land and water use efficiency. The land use efficiency varied least between growers, from (36 to 58 Mg (tonnes) ha⁻¹), water use efficiency returned values between 3 and 9 g potato l⁻¹ water, while chemical fertilizer phosphorus use efficiency varied most at 98 and 995 g potato g⁻¹ P applied. Model outcomes confirmed some of the trends revealed by the survey, e.g. growing potatoes in winter and growing them with less than optimal water offers possibilities to double water use efficiency. Ways to derive indicator threshold norms are proposed based on the knowledge of physical and biological processes determining resource availability, the observed variation among farmers and the model outcomes. Knowing indicator values, their range and the means to improve resource use efficiency will aid in establishing sustainability norms by providing a quantitative approach to any environmental certification scheme that wishes to licence the delivery of potatoes from the Sandveld.  相似文献   

Comparative Earth History and Late Permian Mass Extinction   总被引：6，自引：0，他引：6  

AH Knoll  RK Bambach  DE Canfield  JP Grotzinger 《Science (New York, N.Y.)》1996,273(5274):452-457

The repeated association during the late Neoproterozoic Era of large carbon-isotopic excursions, continental glaciation, and stratigraphically anomalous carbonate precipitation provides a framework for interpreting the reprise of these conditions on the Late Permian Earth. A paleoceanographic model that was developed to explain these stratigraphically linked phenomena suggests that the overturn of anoxic deep oceans during the Late Permian introduced high concentrations of carbon dioxide into surficial environments. The predicted physiological and climatic consequences for marine and terrestrial organisms are in good accord with the observed timing and selectivity of Late Permian mass extinction.  相似文献   

The chemistry of sexual deception in an orchid-wasp pollination system     

Schiestl FP  Peakall R  Mant JG  Ibarra F  Schulz C  Franke S  Francke W 《Science (New York, N.Y.)》2003,302(5644):437-438

The "sexually deceptive" orchid Chiloglottis trapeziformis attracts males of its pollinator species, the thynnine wasp Neozeleboria cryptoides, by emitting a unique volatile compound, 2-ethyl-5-propylcyclohexan-1,3-dione, which is also produced by female wasps as a male-attracting sex pheromone.  相似文献   

Magnetotactic bacteria at the geomagnetic equator     

Frankel RB  Blakemore RP  DE Araujo FF  Esquivel DM  Danon J 《Science (New York, N.Y.)》1981,212(4500):1269-1270

Magnetotactic bacteria are present in fresh water and marine sediments of Fortaleza, Brazil, situated close to the geomagnetic equator. Both South-seeking and North-seeking bacteria are present in roughly equal numbers in the same samples. This observation is consistent with the hypothesis that the vertical component of the geomagnetic field selects the predominant polarity type among magnetotactic bacteria in natural environments.  相似文献