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On the extinction of species in jointly determined stochastic systems
1999
Batabyal, Amitrajeet A.
The lean meat content in carcass of pigs determined in commercial conditions
1999
Demo, P. | Peskovicova, D. | Krska, P. | Bahelka, I. | Porhajas, A. (Research Institute of Animal Production, Nitra (Slovak Republic))
We analysed the meatiness of pigs slaughtered in commercial conditions of meat proccessing factories in Slovakia during the years 1995-1997. The lean meat content (LMC) of carcass body measured by FOM apparatus on 470 634 animals were taken into account. The average LMC in the subset of 136 179 animals slaughtered in 1995 with average dead weight 90.77 kg achieved 47.59% (tab. I) while the LMC increased to 48.74% for subset of 143 857 animals measured in 1997 at average dead weight 90.87 kg (tab. 3). Number of pigs classified as S, E and U rose from 29.71% in 1995 to 41.21% in 1997. More than 30% animals within each of the studied years were slaughtered at the weight from 90.1 to 100 kg. The pigs with dead weight over 110 kg created 8.14 - 10.32% of all analysed data (tab 4). We analysed the average dead weight and average LMC of pigs across years and months as well as the effect of increasing dead weight on the LMC. The content of lean meat in carcass has been decreasing linearly from the dead weight higher than 75 - 80 kg
Afficher plus [+] Moins [-]Biological aspects of genetically determined differences in piglet vitality in the perinatal period
1999
Leenhouwers, J.I.
Tissue distribution of polaprezinc in rats determined by the double tracer method
1999
Furuta, S. | Suzuki, M. | Toyama, S. | Miwa, M. | Sano, H. (Central Research Laboratories Zeria Pharmaceutical Co., Ltd., 2512-1 Oshikiri, Konan-machi, Osato-gun, Saitama 360-0111 (Japan))
Chemical ozone loss in the Arctic winter 1994/95 as determined by the Match technique Texte intégral
1999
Rex, Markus | von der Gathen, Peter | Braathen, G. O. | Harris, N. R. P. | Reimer, E. | Beck, A. | Alfier, R. | Krüger-Carstensen, R. | Chipperfield, M. | De Backer, H. | Balis, D. | O`Connor, F. | Dier, H. | Dorokhov, V. | Fast, H. | Gamma, A. | Gil, M. | Kyrö, E. | Litynska, Z. | Mikkelsen, S. | Molyneux, M. | Murphy, G. | Reid, S. J. | Rummukainen, M. | Zerefos, C.
The chemically induced ozone loss inside the Arctic vortex during the winter 1994/95 has beenquantified by coordinated launches of over 1000 ozonesondes from 35 stations within the Match94/95 campaign. Trajectory calculations, which allow diabatic heating or cooling, were used totrigger the balloon launches so that the ozone concentrations in a large number of air parcels areeach measured twice a few days apart. The difference in ozone concentration is calculated foreach pair and is interpreted as a change caused by chemistry. The data analysis has been carriedout far January to March between 370 K and 600 K potential temperature. Ozone loss along thesetrajectories occurred exclusively during sunlit periods, and the periods of ozone loss coincidedwith, but slightly lagged, periods where stratospheric temperatures were low enough for polarstratospheric clouds to exist. Two clearly separated periods of ozone loss show up. Ozone lossrates first peaked in late January with a maximum value of 53 ppbv per day (1.6 % per day) at475 K and faster losses higher up. Then, in mid-March ozone loss rates at 475 K reached 34 ppbvper day (1.3 % per day), faster losses were observed lower down and no ozone loss was foundabove 480 K during that period. The ozone loss in hypothetical air parcels with average diabaticdescent rates has been integrated to give an accumulated loss through the winter. The most severedepletion of 2.0 ppmv (60 %) took place in air that was at 515 K on 1 January and at 450 K on20 March. Vertical integration over the levels from 370 K to 600 K gives a column lass rate,which reached a maximum value of 2.7 Dobson Units per day in mid-March. The accumulatedcolumn loss between 1 January and 31 March was found to be 127 DU (similar to 36 %).
Afficher plus [+] Moins [-]The structure of organic nitrogen in particle size fractions determined by 15N CPMAS NMR Texte intégral
1999
Knicker, Heike | Schmidt, M. W. I. | Kögel-Knabner, I.
7 pages, 25 references. | Nitrogen availability in soils plays an important role for the productivity of agricultural systems. After entering the soil, material of biogenic origin experiences decay and microbial reworking. During these processes, the labile compounds are quickly mineralized into inorganic nitrogen forms, directly available for the production of new biomass. The more stable compounds and metabolic products accumulate to form the refractory organic pool of soils (Kelly and Stevenson, 1996). Their nitrogen will be sequestered from the overall nitrogen cycle and therefore from bioproductivity over a expended time range. | Peer reviewed
Afficher plus [+] Moins [-]Biogenic and lithogenic silica, silicic acid, production of biogenic silica, and irradiance measurements during the Ross Sea Bloom Project 1994-1996 Texte intégral
1999
Smith, Walker O Jr | Nelson, David M | Mathot, Sylvie
The development of the seasonal phytoplankton bloom in the Ross Sea was studied during two cruises. The first, conducted in November-December 1994, investigated the initiation and rapid growth of the bloom, whereas the second (December 1995-January 1996) concentrated on the bloom's maximum biomass period and the subsequent decline in biomass. Central to the understanding of the controls of growth and the summer decline of the bloom is a quantitative assessment of the growth rate of phytoplankton. Growth rates were estimated over two time scales with different methods. The first estimated daily growth rates from isotropic incorporation under simulated in situ conditions, including 14C, 15N and 32Si uptake measurements combined with estimates of standing stocks of particulate organic carbon, nitrogen and biogenic silica. The second method used daily to weekly changes in biomass at selected locations, with net growth rates being estimated from changes in standing stocks of phytoplankton. In addition, growth rates were estimated in large-volume experiments under optimal irradiances. Growth rates showed distinct temporal patterns. Early in the growing season, short-term estimates suggested that growth rates of in situ assemblages were less than maximum (relative to the temperature-limited maximum) and were likely reduced due to low irradiance regimes encountered under the ice. Growth rates increased thereafter and appeared to reach their maximum as biomass approached the seasonal peak, but decreased markedly in late December. Differences between the major taxonomic groups present were also noted, especially from the isotopic tracer experiments. The haplophyte Phaeocystic antarctica was dominant in 1994 throughout the growing season, and it exhibited the greatest growth rates (mean 0.41/day) during spring. Diatom standing stocks were low early in the growing season, and growth rates averaged 0.100/day. In summer diatoms were more abundant, but their growth rates remained much lower (mean of 0.08/day) than the potential maximum. Understanding growth rate controls is essential to the development of predictive models of the carbon cycle and food webs in Antarctic waters.
Afficher plus [+] Moins [-]Estimating the regional pattern of the mobile water fraction in soils as determined by disc infiltrometer experiments Texte intégral
1999
Kumke, T. | Streck, T. | Richter, J.
Influence of nitrogen fertilization on the nutritional value of high-lysine barley determined in growing pigs
1999
Jorgensen, H. (Danish Inst. of Agricultural Science, Tjele (Denmark). Dept. of Animal Nutrition and Physiology) | Gabert, V.M. | Fernandez, J.A.
Genetic diversity in Finland of the birch endophyte Gnomonia setacea as determined by RAPD-PCR markers
1999
Lappalainen, J.H. | Yli-Mattila, T. (Section of Ecology, Department of Biology, University of Turku, 20014 Turku (Finland))
