Plant-virus interactions and the agro-ecological interface     

H. M. Alexander  K. E. Mauck  A. E. Whitfield  K. A. Garrett  C. M. Malmstrom 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(3):529-547

As a result of human activities, an ever-increasing portion of Earth’s natural landscapes now lie adjacent to agricultural lands. This border between wild and agricultural communities represents an agro-ecological interface, which may be populated with crop plants, weeds of crop systems, and non-crop plants that vary from exotic to native in origin. Plant viruses are important components of the agro-ecological interface because of their ubiquity, dispersal by arthropod vectors, and ability to colonize both crop and wild species. Here we provide an overview of research on plant-virus dynamics across this interface and suggest three research priorities: (1) an increased effort to identify and describe plant virus diversity and distribution in its entirety across agricultural and ecological boundaries; (2) multi-scale studies of virus transmission to develop predictive power in estimating virus propagation across landscapes; and (3) quantitative evaluation of the influence of viruses on plant fitness and populations in environmental contexts beyond crop fields. We close by emphasizing that agro-ecological interfaces are dynamic, influenced by the human-mediated redistribution of plants, vectors, and viruses around the world, climate change, and the development of new crops. Consideration of virus interactions within these environmentally complex systems promises new insight into virus, plant, and vector dynamics from molecular mechanisms to ecological consequences.  相似文献   

In-vitro antibacterial properties of tilmicosin against Australian isolates of Pasteurella multocida and Actinobacillus pleuropneumoniae from pigs   总被引：1，自引：0，他引：1  

PJ BLACKALL  T. ASAKAWA  RJ GRAYDON  M. WHITE  M. ADAMSON  LK WADE  LB LOWE 《Australian veterinary journal》1995,72(1):35-36

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Ostrich anaesthesia: xylazine premedication followed by alphaxalone/alphadolone and isoflurane     

LK CULLEN  MA GOERKE  RA SWAN  WT CLARK  D NANDAPI  C COLBOURNE 《Australian veterinary journal》1995,72(4):153-154

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Effects of Vasectomy on Seminal Plasma Alkaline Phosphatase in Male Alpacas (Vicugña pacos)     

LK Pearson  AJ Campbell  S Sandoval  A Tibary 《Reproduction in domestic animals》2013,48(6):995-1000

Azoospermia is a common finding in male alpacas which present for infertility. The challenge is to differentiate azoospermia of testicular origin from non‐testicular origin. In several species, alkaline phosphatase (AP) concentrations in seminal plasma have been used as a diagnostic marker of contributions of the testis and epididymis to the ejaculate. The purpose of this study was to determine whether AP assay could differentiate testicular from non‐testicular azoospermia in male alpacas. An experimental model of bilateral outflow obstruction (pre‐scrotal vasectomy) was used in 22 male alpacas, aged 2–9 years. No reproductive history was available. Animals were submitted for electroejaculation (EE) under general anaesthesia and vasectomy performed. Five weeks later, animals were submitted for EE. Vasectomy was not successful in one animal, which was removed from analysis. AP levels were compared in seminal plasma in the pre‐ and post‐vasectomy samples. The mean ± SEM concentration of AP in pre‐vasectomy seminal plasma was 504.29 ± 166.45 U/l (range 10–2910); the post‐vasectomy levels were 252.48 ± 81.77 U/l (range 0–1640; p = 0.06). In 71.4% of animals, AP levels decreased, varying from 18% to 100% reduction. Results of this study suggest that AP is not produced exclusively by the testis and epididymis in alpacas and that AP assay is not a valid diagnostic test for determination of origin of azoospermia; the gold standard for diagnosis of origin of azoospermia remains testicular biopsy.  相似文献   

Amygdala response to happy faces as a function of extraversion     

Canli T  Sivers H  Whitfield SL  Gotlib IH  Gabrieli JD 《Science (New York, N.Y.)》2002,296(5576):2191

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Pre-weaning morbidity and mortality of llamas and alpacas     

MS Sharpe  LK Lord  TE Wittum  DE Anderson 《Australian veterinary journal》2009,87(1-2):56-60

Objectives   To describe the morbidity and mortality patterns and identify factors associated with morbidity in pre-weaning llamas and alpacas.
Design   Cross-sectional observational study of 287 crias born on four farms in Ohio, USA
Procedure   Historical data representing all crias born over a 6-year period were obtained from two llama farms and two alpaca farms in Ohio. Multivariable generalised linear mixed effects regression models were used to identify factors associated with morbidity outcomes.
Results   In total, 105 (37%) of the llamas and alpacas had some reported morbidity during the pre-weaning period, and mortality rate was 2.1%. In addition, 51 (18%) of llamas and alpacas experienced morbidity because of infectious disease, and 47 (16%) experienced morbidity during the neonatal period. The three most commonly reported morbidity events were undifferentiated diarrhoea (23%), umbilical hernia (16%) and unspecified infectious disease (15%). Difficult birth was an important risk factor for pre-weaning morbidity in this population.
Conclusions   Camelid veterinarians and their clients can expect that pre-weaning health events are common among crias, although mortality is low. Crias experiencing difficult births may require additional monitoring for health events during the pre-weaning period.  相似文献   

Pleistocene extinction of genyornis newtoni: human impact on australian megafauna     

GH Miller  JW Magee  BJ Johnson  ML Fogel  NA Spooner  MT McCulloch  LK Ayliffe 《Science (New York, N.Y.)》1999,283(5399):205-208

More than 85 percent of Australian terrestrial genera with a body mass exceeding 44 kilograms became extinct in the Late Pleistocene. Although most were marsupials, the list includes the large, flightless mihirung Genyornis newtoni. More than 700 dates onGenyornis eggshells from three different climate regions document the continuous presence of Genyornis from more than 100,000 years ago until their sudden disappearance 50,000 years ago, about the same time that humans arrived in Australia. Simultaneous extinction of Genyornis at all sites during an interval of modest climate change implies that human impact, not climate, was responsible.  相似文献   

An Evaluation of Immunofluorescence and PCR. Methods for Detection of Rabies in Archival Carnoy-Fixed,Paraffin-Embedded Brain Tissue*     

K. Kulonen  M. Fekadu  S. Whitfield  C. K. Warner 《Zoonoses and public health》1999,46(3):151-156

Direct immunofluorescence and PCR detection methods were compared for sensitivity in evaluating the rabies status of archival specimens of Carnoy-fixed, paraffin-embedded brain tissue. The material consisted of 23 samples obtained during a rabies outbreak in Finland in 1988, and one sample isolated from a bat researcher who died of rabies in Finland in 1985. These results were compared with the original diagnoses performed on the fresh tissues. The immunofluorescence assay detected 100% (12/12) of the rabies-positive archival cases. A PCR assay designed to detect a 139-bp target near the 5′ end of the rabies nucleoprotein gene also detected 100% (12/12) of the samples identified as positive in the fresh tissue specimens. A PCR assay designed to detect a 304-bp target spanning the 139-bp target of the first assay detected only 67% (8/12) of the original cases. No false positives were recorded. Both immunofluorescence detection of antigen and PCR detection of a short region of the nucleoprotein gene are useful in determining the rabies status of fixed, paraffin-embedded (archival) material.  相似文献