Investigation of the distance to slaughterhouses and weather parameters in the occurrence of porcine reproductive and respiratory syndrome outbreaks in U.S. swine breeding herds     

Justin Moeller  Jerry Mount  Emily Geary  Magnus R. Campler  Cesar A. Corzo  Robert B. Morrison  Andria G. Arruda 《The Canadian veterinary journal. La revue veterinaire canadienne》2022,63(5):528

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important diseases affecting the swine industry. The main objective of this study was to assess whether sow farm distance to slaughterhouses and meteorological variables were associated with PRRS outbreaks. This case-control study paired 104 sow farms with or without a reported PRRS outbreak (N = 208) during the same period. Data on the distance to the closest slaughterhouse, swine density, presence of an air filtration system, or a neighboring farm, and weather conditions were collected, and a multivariable conditional logistic regression model was created to investigate the association between variables of interest and the occurrence of a PRRS outbreak.Swine density, presence of an air filtration system, presence of a neighboring farm, and PRRS herd-level status before the outbreak were associated with the occurrence of PRRS outbreaks. Farms in areas with higher swine density and nearby swine farms had increased odds of reporting an outbreak compared to farms in low swine density areas and farms having no neighbors. Under the conditions of this study, none of the meteorological variables or the distance to the closest slaughterhouse were associated with occurrence of PRRS outbreaks.  相似文献   

Camel trypanosomosis in the Canary Islands: assessment of seroprevalence and infection rates using the card agglutination test (CATT/T. evansi) and parasite detection tests     

Gutierrez C  Juste MC  Corbera JA  Magnus E  Verloo D  Montoya JA 《Veterinary parasitology》2000,90(1-2):155-159

Trypanosomosis due to Trypanosoma evansi (surra) is a major enzootic disease of the dromedary camel. Thus, the purpose of the present study was to assess seroprevalence and infection rates in the Canary Islands using antibody(-card agglutination test-CATT/T. evansi) and parasite detection tests (micro-Haematocrit Centrifugation technique, Giemsa stained blood smears, microscopic examination of lymph node aspirates and mouse inoculation). PCV was also determined. 745 dromedary camels (483 females and 262 males) were examined. Trypanosomes were detected in seven animals. 36 animals yielded CATT positive results while 709 animals were negative. All parasitologically positive animals were also CATT positive. Results showed a good correlation between CATT positive and low PCV and a higher seroprevalence in older animals. Trypanocidal drugs have not been registered in Spain and, consequently, if vigilance is not exercised the prevalence could be increased in the future.  相似文献   

ECG of the month. Atrial fibrillation in a cow with meningitis     

J Pringle  R Gompf  R Magnus 《Journal of the American Veterinary Medical Association》1990,196(1):56-57

  相似文献   

Growth and mortality in underplanted tree seedlings in response to variations in canopy closure of Norway spruce stands   总被引：2，自引：0，他引：2  

Lof  Magnus; Karlsson  Matts; Sonesson  Kerstin; Welander  Torkel N.; Collet  Catherine 《Forestry》2007,80(4):371-383

Six broadleaved tree species and Picea abies (L.) Karst. wereplanted under spruce plantations of varying densities, in Sweden.Treatments included control (994 stems ha^–1), dense (538stems ha^–1), sparse (294 stems ha^–1) and gap (0stems ha^–1) overstory treatments. There was an increasein height and diameter growth from control to sparse overstorytreatment of all underplanted tree species except for ash (Fraxinusexcelsior L.) and Norway maple (Acer platanoides L.). Site conditionsmay have hampered the growth of these species, as well as wildcherry (Prunus avium L.). Both oak (Quercus robur L.) and sprucehad greater growth in the gap treatment, relative to the othertreatments. Insecticide application did not influence seedlinggrowth or survival. The performance of beech (Fagus sylvaticaL.), lime (Tilia cordata Mill.), spruce and oak was consistentwith shade tolerance ranking. Beech and lime had a very highsurvival rate, even under the densest canopy. The growth andmortality of ash, maple and wild cherry differed significantlyfrom what was expected. This experiment demonstrated significantvariation in interspecific growth and mortality between sevenplanted tree species in relation to canopy density. Correctsite and species selection is crucial when underplanting inshelterwood systems.  相似文献   

Herbivory by the pine weevil (Hylobius abietis L.) and short-snouted weevils (Strophosoma melanogrammum Forst. and Otiorhynchus scaber L.) during the conversion of a wind-thrown Norway spruce forest into a mixed-species plantation     

Magnus Lf  Gunnar Isacsson  Dan Rydberg  Torkel N. Welander 《Forest Ecology and Management》2004,190(2-3):281-290

The influence of above-ground insect herbivory and other agents of damage to seedlings was studied in a field experiment. Nine different tree species were planted in each of five randomised blocks. The species were: Alnus glutinosa (L.) Gaertner, Betula pendula Roth., Fagus sylvatica L., Fraxinus excelsior L., Larix eurolepis Henry, Picea abies (L.) Karst., Prunus avium L., Quercus robur L. and Tilia cordata Mill. The seedlings were monitored through the 2000–2002 growing seasons. Pine weevils (Hylobius abietis L.) fed significantly more on Norway spruce seedlings than on all other tree species. The following rough preference order was obtained: Norway sprucelarch>birch, beech, oak>cherry>alder, ash, lime. Thus, during the conversion of single-species coniferous plantations to mixed-species broadleaved stands, the use of costly insecticides against pine weevil is not required. Short-snouted weevils (e.g. Strophosoma melanogrammum Forst. and Otiorhynchus scaber L.) and other insects caused leaf and needle area loss primarily during the first growing season.  相似文献   

Evidence of Lower Productivity in Long Term Limed Lakes as Compared to Unlimed Lakes of Similar pH     

Gunnar Persson  Magnus Appelberg 《Water, air, and soil pollution》2001,130(1-4):1769-1774

Ecosystem development in lime-treated waters in Sweden has been followed since 1989 in a programme for integrated studies of the effects of liming acidified waters (ISELAW). Observations after prolonged liming (>10 y) indicate a phosphorus depletion in the limed lakes which contrasts to the increased phosphorus supply often following within the initial years after lime treatment. After prolonged liming, the levels of total phosphorus are lower as compared to neutral reference lakes at identical TOC, and the phosphorus/TOC -ratio is consequently lower in limed lakes. Depletion of dissolved inorganic nitrogen during the summer is also lower in limed as compared to neutral reference lakes. Phytoplankton biomass and species number also lower in the limed lakes as compared to unlimed neutral references. Furthermore the bacterial number per unit TOC is lower in the long term limed lakes, possibly as a result of phosphorus limitation. As to the higher trophic levels, the benthic soft-bottom fauna of limed lakes (specifically the sublittoral fauna) is poorer in terms of species diversity and abundance. Also fish community composition indicates lower productivity in the limed lakes. Taken together there is thus evidence that the long term limed lakes have a lower trophic level than reference lakes.  相似文献   

Policy forum: genetics. Ethical considerations in synthesizing a minimal genome     

Cho MK  Magnus D  Caplan AL  McGee D 《Science (New York, N.Y.)》1999,286(5447):2087, 2089-2087, 2090

  相似文献   

A single IGF1 allele is a major determinant of small size in dogs   总被引：3，自引：0，他引：3  

Sutter NB  Bustamante CD  Chase K  Gray MM  Zhao K  Zhu L  Padhukasahasram B  Karlins E  Davis S  Jones PG  Quignon P  Johnson GS  Parker HG  Fretwell N  Mosher DS  Lawler DF  Satyaraj E  Nordborg M  Lark KG  Wayne RK  Ostrander EA 《Science (New York, N.Y.)》2007,316(5821):112-115

The domestic dog exhibits greater diversity in body size than any other terrestrial vertebrate. We used a strategy that exploits the breed structure of dogs to investigate the genetic basis of size. First, through a genome-wide scan, we identified a major quantitative trait locus (QTL) on chromosome 15 influencing size variation within a single breed. Second, we examined genetic variation in the 15-megabase interval surrounding the QTL in small and giant breeds and found marked evidence for a selective sweep spanning a single gene (IGF1), encoding insulin-like growth factor 1. A single IGF1 single-nucleotide polymorphism haplotype is common to all small breeds and nearly absent from giant breeds, suggesting that the same causal sequence variant is a major contributor to body size in all small dogs.  相似文献   

THE APPLICATION OF SCIENTIFIC METHOD TO EDUCATIONAL PROBLEMS     

Magnus P 《Science (New York, N.Y.)》1907,26(670):574-586

  相似文献   

Forest vegetation management under debate: an introduction     

Christian Ammer  Philippe Balandier  Niclas Scott Bentsen  Llu��s Coll  Magnus L?f 《European Journal of Forest Research》2011,130(1):1-5

  相似文献