Effects of land use on infestation and parasitism rates of cabbage seed weevil in oilseed rape     

Gabriella Kovcs  Riina Kaasik  Marjolein E Lof  Wopke van der Werf  Tanel Kaart  John M Holland  Anne Luik  Eve Veromann 《Pest management science》2019,75(3):658-666

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Grassland vegetation changes and nocturnal global warming   总被引：4，自引：0，他引：4  

RD Alward  JK Detling  DG Milchunas 《Science (New York, N.Y.)》1999,283(5399):229-231

Global minimum temperatures (TMIN) are increasing faster than maximum temperatures, but the ecological consequences of this are largely unexplored. Long-term data sets from the shortgrass steppe were used to identify correlations between TMIN and several vegetation variables. This ecosystem is potentially sensitive to increases in TMIN. Most notably, increased spring TMIN was correlated with decreased net primary production by the dominant C4 grass (Bouteloua gracilis) and with increased abundance and production by exotic and native C3 forbs. Reductions in B. gracilis may make this system more vulnerable to invasion by exotic species and less tolerant of drought and grazing.  相似文献   

Vertical movements of Atlantic salmon post-smolts relative to measures of salinity and water temperature during the first phase of the marine migration     

N. PLANTALECH MANEL-LA  E. B. THORSTAD  J. G. DAVIDSEN  F. ØKLAND  R. SIVERTSGÅRD  R. S. MCKINLEY  & B. FINSTAD 《Fisheries Management and Ecology》2009,16(2):147-154

Abstract  The migratory behaviour of hatchery-reared Atlantic salmon, Salmo salar L., post-smolts during the first phase of the marine migration was examined to assess their susceptibility to salmon lice, Lepeophtheirus salmonis (Krøyer), infestations. Swimming depths of eight post-smolts relative to the measured salinity and temperature were monitored for an average of 11.4 h following release outside the mouth of the River Eio using depth sensitive acoustic transmitters. Vertical salinity and temperature distributions were simultaneously recorded along the migratory route. Mean swimming depth was 1.7 m (individual mean 0.5–2.1 m). There was no overall preference among all the post-smolts for specific salinity concentrations. Typically post-smolts migrated the majority (68%) of their time at salinities <20 psu (brackish water), and as a result outside the reported salinity tolerances of sea lice. Furthermore, post-smolts chose the warmest water layer during their coastal migration.  相似文献   

LETTERS     

C. T. Holland  BVSc. 《Veterinary radiology & ultrasound》1992,33(6):326-326

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Evaluation of ultrasound imagery and body shape to predict carcass and fillet yield in farm-raised catfish.   总被引：1，自引：0，他引：1  

B G Bosworth  M Holland  B L Brazil 《Journal of animal science》2001,79(6):1483-1490

Accurate prediction of meat yield in live animals may allow more efficient genetic improvement of meat yield in farm-raised catfish. An initial trial with 30 channel catfish demonstrated significant correlations among weight-adjusted residuals for muscle area measured from transverse ultrasound images and transverse sections at five locations along the trunk musculature (r = 0.30 to 0.70). Relationships of weight-adjusted residuals for three meat yield traits (carcass, whole fillet, and shank fillet) with weight-adjusted residuals for 15 external body shape measurements and five transverse ultrasound measurements of muscle area were determined for 51 female and 91 male channel x blue catfish backcross hybrids. Compared to males, females had smaller heads; deeper, wider, shorter bodies; larger ultrasound muscle area; and higher meat yield. Correlations between carcass traits and body shape and carcass traits and ultrasound measurements were generally higher for females than for males. Correlations among carcass traits and ultrasound muscle area were typically higher than correlations among carcass traits and external body shape in both sexes. A single ultrasound measurement explained 40 to 50% and 16 to 23% of the variation in meat yield traits of females and males, respectively. The best three-variable model using ultrasound and body shape traits explained 48 to 56% and 31 to 38% of the variation in meat yield traits in females and males, respectively. Differences between males and females for the variability in meat yield traits explained by the models may be related to sexual dimorphism for body shape and fillet yield observed in catfish. Ultrasound has potential for predicting meat yield in live fish, but improved prediction accuracy is needed. Differences in meat yield traits between males and females and among individuals within sexes suggest that selecting for fish with smaller heads and deeper, shorter body shape posterior to the visceral cavity will increase meat yield in catfish.  相似文献   

Investigation of the molecular detection of vaccine-derived equine herpesvirus type 1 in blood and nasal secretions from horses following intramuscular vaccination.     

Nicola Pusterla  Kristin P Chaney  Roger Maes  Annabel G Wise  Robert Holland  Hal C Schott 《Journal of veterinary diagnostic investigation》2007,19(3):290-293

The objective of this study was to investigate whether intramuscular vaccination of healthy adult horses with a killed or a modified live equine herpesvirus type 1 (EHV-1) vaccine could induce transient positive PCR results in either blood or secretions collected on a nasopharyngeal swab. Four horses in each group received either a single killed or a modified-live vaccine intramuscularly. Two local commingled and 2 distant nonvaccinated controls were included for each group. All horses were observed daily for evidence of clinical abnormalities throughout the study periods. Blood and nasopharyngeal swabs were collected twice before vaccination and once weekly for 4 weeks after vaccination and submitted for PCR testing for EHV-1 by 2 independent laboratories using different real-time PCR methodologies. Serum samples collected from all horses on the vaccination day and 21 days later were tested for antibodies against EHV-1 using a serum neutralization test. Whereas the 2 vaccine strains tested positive in both EHV-1 PCR assays, nasopharyngeal swabs and whole blood collected from vaccinated and control horses had negative PCR test results for EHV-1 during the entire study period. Serum neutralization testing revealed a 2- to 4-fold increase in titers for all vaccinated horses, whereas titers in control horses were largely unchanged. The use of seropositive horses before immunization and the sampling frequency of 7 days may have prevented the occasional molecular detection of the vaccine virus in whole blood and nasopharyngeal secretions. However, the study results demonstrate that detection of EHV-1 DNA by PCR in vaccinated and unvaccinated healthy horses is not a common event.  相似文献   

Antigenic and immunogenic studies on cell culture-derived Babesia canis     

Enrique Molinar  Mark A. James  Ibulaimu Kakoma  Cynthia Holland  Miodrag Ristic 《Veterinary parasitology》1982,10(1):29-40

Babesia canis antigens derived from cell culture reacted specifically with immune serum from dogs convalescing from babesiosis. The antigens were heterogenous as compared to antigens elaborated in vivo. The major antigenic moiety from cell culture eluted in the first peak of Sephadex G-200 is indicative of a molecular weight around 900 000. In contrast, in vivo-derived antigen coeluted with albumin and hemoglobin suggesting a molecular weight of 67 000. The major antigenic mass is proteinacious and contains disulfide bonds as indicated by thermolability and sensitivity to 2-mercaptoethanol. Both particulate and soluble B. canis antigens were immunogenic, particularly when emulsified in Saponin as an adjuvant. Such antigens conferred a considerable degree of protection in susceptible dogs and it suggested that immunoprophylaxis to B. canis may be feasible.  相似文献   

Emerging diseases in northern Europe     

Holland M 《The Journal of small animal practice》2001,42(4):205-206

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Comparison of serological tests for Trypanosoma evansi natural infections in water buffaloes from north Vietnam     

Verloo D  Holland W  My LN  Thanh NG  Tam PT  Goddeeris B  Vercruysse J  Büscher P 《Veterinary parasitology》2000,92(2):87-96

In the present study, a collection of 415 water buffalo serum samples originating from the north of Vietnam was used for evaluation of different diagnostic antibody detection methods available to detect infections with Trypanosoma evansi. The diagnostic sensitivity and specificity of a direct card agglutination test (CATT/T. evansi), an indirect card agglutination test (LATEX/T. evansi) and a newly developed antibody detection ELISA (ELISA/T. evansi) was calculated on the basis of parasitological results, obtained by mouse inoculation, and compared for all assays. The immume trypanolysis assay with the predominant T. evansi RoTat 1.2 variable antigen type was used as reference test for antibody presence. All parasitologically confirmed animals (n=8) were positive in all tests. Diagnostic specificity was highest in CATT/T. evansi (98%) followed by the ELISA/T. evansi (95%) and the LATEX/T. evansi (82%). Concordance of the variant specific immune trypanolysis test with the other tests was calculated and revealed that few (1-8%) false positive results were actually due to a specific reactions, and that LATEX/T. evansi and ELISA/T. evansi detected more immune trypanolysis positives than the CATT/T. evansi. It was concluded that, apart from the immune trypanolysis test, which is not generally applicable, ELISA/T. evansi with a 30% positivity cut-off and LATEX/T. evansi, thanks to their superior capacity of detecting T. evansi specific antibodies, would be suitable as epidemiological tools detecting both active infections and persisting T. evansi specific antibodies. The ELISA/T. evansi with a 50% positivity cut-off and the CATT/T. evansi on the other hand, seem more appropriate to detect true infected water buffaloes.  相似文献   

Compositional stratification in the deep mantle   总被引：2，自引：0，他引：2  

Kellogg LH  Hager BH  van der Hilst RD 《Science (New York, N.Y.)》1999,283(5409):1881-1884

A boundary between compositionally distinct regions at a depth of about 1600 kilometers may explain the seismological observations pertaining to Earth's lower mantle, produce the isotopic signatures of mid-ocean ridge basalts and oceanic island basalts, and reconcile the discrepancy between the observed heat flux and the heat production of the mid-ocean ridge basalt source region. Numerical models of thermochemical convection imply that a layer of material that is intrinsically about 4 percent more dense than the overlying mantle is dynamically stable. Because the deep layer is hot, its net density is only slightly greater than adiabatic and its surface develops substantial topography.  相似文献