Carcinogen in rock fern (Chielanthes sieberi) from New Zealand and Australia     

BL SMITH  PP EMBLING  DR LAUREN  MP AGNEW  AD ROSS  PL GREENTREE 《Australian veterinary journal》1989,66(7):230-231

  相似文献   

Population structure and regeneration status of Vitellaria Paradoxa (C. F. Gaertner) under different land management regimes in Atacora department,Benin     

Koutchoukalo Aleza  Kperkouma Wala  Jules Bayala  Grace B. Villamor  Marra Dourma  Wouyo Atakpama  Koffi Akpagana 《Agroforestry Systems》2015,89(3):511-523

  相似文献   

HIV-associated dementia     

Major EO  Rausch D  Marra C  Clifford D 《Science (New York, N.Y.)》2000,288(5465):440-442

  相似文献   

Migratory birds and avian flu     

Fergus R  Fry M  Karesh WB  Marra PP  Newman S  Paul E 《Science (New York, N.Y.)》2006,312(5775):845-846

  相似文献   

Characterization and taxonomic reassessment of the box blight pathogen Calonectria pseudonaviculata,introducing Calonectria henricotiae sp. nov.          下载免费PDF全文

B. Gehesquière  J. A. Crouch  R. E. Marra  K. Van Poucke  F. Rys  M. Maes  B. Gobin  M. Höfte  K. Heungens 《Plant pathology》2016,65(1):37-52

Calonectria pseudonaviculata, the causal agent of the disease of Buxus spp. known as ‘box blight’, was first detected in the mid‐1990s in the UK and New Zealand. Since then, the geographic range of box blight has rapidly expanded to at least 21 countries throughout temperate regions of the world, causing significant losses in nurseries, gardens and wild boxwood populations. This study determined the genetic diversity in a collection of 234 Calonectria isolates from diseased Buxus plants, originating from 15 countries and four continents. Two genetic clades, G1 and G2, were identified within this sample using multilocus phylogenetic analysis. The application of genealogical concordance phylogenetic species recognition criteria using four independent nuclear loci determined that the Calonectria isolates in these two clades are separate phylogenetic species. The isolates in the G1 clade were upheld as C. pseudonaviculata sensu stricto. Based on phylogenetic distinctiveness and the lack of mating, a new species is proposed, Calonectria henricotiae sp. nov., for the Calonectria isolates in the G2 clade. A PCR‐RFLP assay and real‐time PCR assays were developed to easily and reproducibly differentiate these species. To assess the practical implications of the identification of the two species, their physiology, fungicide susceptibility and pathogenicity were compared. No differences in pathogenicity were observed. However, C. henricotiae isolates exhibited greater thermotolerance and reduced sensitivity to specific triazole as well as strobilurin fungicides. The identification of a second phylogenetic species causing box blight may have a substantial impact on the epidemiology and control of this destructive disease.  相似文献   

Do We Adequately Control for Unmeasured Confounders When Estimating the Short-term Effect of Air Pollution on Mortality?     

Giampiero Marra  Rosalba Radice 《Water, air, and soil pollution》2011,218(1-4):347-352

Numerous time series studies have quantified the potential association between daily variations in air pollution and daily variations in non-accidental deaths. In order to account for the presence of unmeasured confounders, a smooth function of time trend is typically used as a proxy for these variables. We shed light on the validity of the results obtained by using this approach. Specifically, we use data from the National Morbidity, Mortality and Air Pollution Study database, and carry out a carefully designed simulation study. Our findings suggest that the use of a smooth function of time trend cannot fully account for the presence of unmeasured confounders, especially when their impact is strong relatively to the effect of air pollution, and when several unobservables are not included in the model.  相似文献   

Commodity program flexibility and U.S. potato acreage     

Hsiang-Tai Cheng  Michele C. Marra  James D. Leiby 《American Journal of Potato Research》1992,69(10):677-690

A new proposal for U.S. farm commodity programs would allow more flexibility in planting decisions on program acreage. This work examines the effect of such a proposal on potato production acreage. These results are used to project changes in total revenue accruing to existing potato producers and to the potato industry as a whole. The results indicate that the short term impact on the potato industry as a whole would be relatively minor but the impact could be unevenly distributed across producing regions of the U.S., causing some potential local discomfort.  相似文献   

Carcinogen in rock fern (Cheilanthes sieberi) from New Zealand and Australia     

BL SMITH  PP EMBLING  DR LAUREN  MP AGNEW  AD ROSS  PL GREENTREE 《Australian veterinary journal》1989,66(5):154-155

  相似文献   

Brucellosis in Ontario: a case control study.   总被引：1，自引：1，他引：0       下载免费PDF全文

J Kellar  R Marra    W Martin 《Canadian journal of veterinary research》1976,40(2):119-128

Data from cattle herds infected with brucellosis and from control (noninfected) herds were collected and analyzed using case control techniques. It appeared that herds located close to other infected herds and those herds whose owners made frequent purchases of cattle had an increased risk of acquiring brucellosis, particularly those who made purchases from other herds or from cattle dealers. Infected herds had a lower level of vaccination than noninfected herds. However, the percentage vaccinated was highly variable in each group. Vaccination per se did not appear to adversely influence the interpretation of serological test results nor did it appear to protect the individual animal. Once infected, the time required to become free of brucellosis was increased by large herd size and/or loose housing. Closed herds also took longer to become brucellosis free than more open herds. The percentage of animals removed from the herd was increased by active abortion. Those herds with multiple serological reactors (positives and questionables) at the first herd test after the imposition of quarantine had the highest percentage of cattle removed.  相似文献   

Reproductive effort, molting latitude, and feather color in a migratory songbird     

Norris DR  Marra PP  Montgomerie R  Kyser TK  Ratcliffe LM 《Science (New York, N.Y.)》2004,306(5705):2249-2250

Toward the end of the breeding season, migratory songbirds face crucial tradeoffs between the timing of reproduction, molt, and migration. Using stable hydrogen isotopes, we show that male American redstarts investing in high levels of reproduction late in the season adopt a unique strategy of combining molt and migration. Tail feathers molted during migration also reflect less orange-red light, indicating reduced carotenoid concentration. Thus, we show how reproduction in a migratory animal can influence both life history strategies (location of molt) and social signals (feather color) during subsequent periods of the annual cycle.  相似文献