Nitrate leaching from organic farms and conventional farms following best practice

Abstract. This paper compares nitrate leaching losses from organic farms, which depended on legumes for their nitrogen inputs (66 site years) with those from conventional farms using fertilizers under similar cropping and climatic conditions (188 site years). The conventional farms were within Nitrate Sensitive Areas in England, but sites following special practices associated with that scheme were excluded. Nitrate losses during the organic ley phase (including the winter of ploughing out) were similar (45 kg N ha^–1) to those from conventional long-term grass receiving fertilizer N inputs of less than 200 kg N ha^–1 (44 kg N ha^–1) and from the grass phase of conventional ley-arable rotations (50 kg N ha^–1). Losses from conventional grass receiving higher N inputs were greater than from organic or less intensive grass. Nitrate losses following arable crops averaged 47 and 58 kg N ha^–1 for the organic and conventional systems respectively, with part of the difference being due to the greater proportion of non-cereal break crops in the latter. Thus under similar cropping, losses from organic systems are similar to or slightly smaller than those from conventional farms following best practice.     

INTEROBSERVER VARIABILITY OF VERTEBRAL HEART SIZE MEASUREMENTS IN DOGS WITH NORMAL AND ENLARGED HEARTS

The vertebral heart size (VHS) method by Buchanan is based on anatomic landmarks. A potential source of variation among observers is differences in the selection of measurement points. The objective was to test variability between observers with different levels of training in thoracic radiology and small animal clinical practice. Fifty sets of thoracic radiographs of cavalier King Charles spaniels, were divided into five groups; (Normal) normal cardiopulmonary structures, (I) slight cardiomegaly, (II) moderate cardiomegaly, (II +) moderate cardiomegaly with congestive heart failure, and (III +) severe cardiomegaly with congestive heart failure. Cardiomegaly was confirmed by echocardiography to be caused by mitral regurgitation because of myxomatous mitral valve disease. Sixteen observers representing four levels of experience (four observers/level) evaluated the radiographs; (1) European Diplomates in Veterinary Diagnostic Imaging, (2) Experienced small animal clinicians, (3) Trainees in small animal clinical practice (4) Veterinary students. Almost identical mean VHS values were found among the four experience levels for each of the five groups of radiographs with a low coefficient of variation, range 1.5-3.2%. Mean difference among the 16 observers was 1.05 +/- 0.32 vertebrae (v). Mean difference among individuals in each observer group was approximately 0.5 v for all but the groups of trainees were the difference was 0.6-0.9 v. The conclusion is that VHS method for heart size is independent of observer experience but dependent of individual observers selection of reference points and transformation of long and short axis dimensions into VHS units.     

Characterization of advertisements for puppies sold online: determinants of cost and a comparison with parent club breeders

The Internet is an increasingly common way for consumers to purchase puppies. Yet very little information is available about the types of puppies sold via the Internet. In addition these sales are not subject to United States Depart of Agriculture (USDA) regulation. The objectives of the study were to describe puppies sold via the Internet, to assess the characteristics that contribute to the cost of a puppy, and to compare puppies sold via the Internet with puppies sold by American Kennel Club (AKC) Parent Club breeders. Over 14 weeks in 2008, Yorkshire Terrier, Shih Tzu, English Bulldog, Boxer, and Labrador Retriever puppies for sale on two large-scale online puppy sales sites were categorized based on their Internet advertisements. Data were collected in three categories: puppy characteristics, health characteristics, and policies (such as spay/neuter requirement, health guarantee, and return policy). After the survey was completed, 25 AKC Parent Club breeders and 25 other breeders who advertised via one of the puppy sales websites were randomly selected and interviewed over the phone. Small breed puppies were most frequently advertised with 35.2% (1228/3485) of advertisements for Yorkshire Terriers and 23.0% (802/3485) for Shih Tzus. Almost one quarter of Internet breeders 768/3474 (22.2%) advertised four or more different dog breeds. Champion bloodlines increased the cost of a puppy of all breeds. AKC Parent Club breeders 21/25 (84%) were more likely to mention breed-specific health screening tests when compared to Internet breeders 7/25 (28%). Consumers should apply the same standards for purchasing from a breeder found through a puppy sales site as they would for purchasing from a local breeder. Breeders who advertise at one of the large-scale puppy sales websites are less knowledgeable about breed-specific health issues compared to an AKC Parent Club breeder. Internet breeders are less likely to perform these screening tests on their breeding dogs and may breed dogs with undesirable heritable health risks.     

Temperature and surface-ocean water balance of the mid-holocene tropical western pacific

Skeletal Sr/Ca and 18O/16O ratios in corals from the Great Barrier Reef, Australia, indicate that the tropical ocean surface approximately 5350 years ago was 1 degrees C warmer and enriched in 18O by 0.5 per mil relative to modern seawater. The results suggest that the temperature increase enhanced the evaporative enrichment of 18O in seawater. Transport of part of the additional atmospheric water vapor to extratropical latitudes may have sustained the 18O/16O anomaly. The reduced glacial-Holocene shift in seawater 18O/16O ratio produced by the mid-Holocene 18O enrichment may help to reconcile the different temperature histories for the last deglaciation given by coral Sr/Ca thermometry and foraminiferal oxygen-isotope records.     

Evaluation of polysaccharide, lipopolysaccharide, and beta-glucan antigens in gel immunodiffusion tests for brucellosis in cattle.

In Venezuela, 1,012 cattle sera were screened for their ability to precipitate Brucella melitensis 16M smooth-lipopolysaccharide (S-LPS), B melitensis B115 polysaccharide B (poly B), B abortus 1119-3 O-polysaccharide (PS), or B abortus 1119-3 cyclic 1,2 linked beta-D-glucan (beta-glucan) in an agar-gel immunodiffusion assay. These sera were previously classified as being Brucella abortus-infected, S-19-vaccinated, or negative after an assessment of historical records and results of 5 standard serologic tests. Most of the sera (85%) from infected cattle precipitated S-LPS, poly B, and PS. Serologic results for poly B and PS were identical. On the other hand, 13% of the sera from vaccinated cattle precipitated S-LPS, but none of these sera precipitated poly B or PS. It was concluded that purified PS can alternate with poly B as an antigen to differentiate sera of B abortus-infected from B abortus S-19-vaccinated cattle. None of these sera precipitated beta-glucan.