Evaluation of two N cycle models for the prediction of N mineralization from grassland soils in the UK

Abstract. The ability of two nitrogen cycle models, of contrasting complexity, to predict N mineralization from a range of grassland soils in the UK, was evaluated. These were NCYCLE, a simple mass balance model of the N cycle in UK grasslands, and CENTURY, a more complex model simulating long-term C, N, P & S dynamics in grassland ecosystems. The models were tested using field measurements of net N mineralization from a range of grassland soils (differing in soil type, history & management practice), obtained over a 2 year period using a soil core incubation technique. This method was considered to measure the total net release of mineral N from the soil organic matter over a specified time, including N which may have been recycled several times. NCYCLE consistently under-estimated mineralization rates at all sites. By contrast, there was some correlation between CENTURY predictions of net N mineralization and field measurements. This may have reflected the different abilities of the two models to simulate N recycling. Neither model, however, was able to predict adequately the effect of cultivation and reseeding on net N mineralization.     

Acupuncture for general veterinary practice.

Since the International Society of Veterinary Acupuncture (IVAS) was founded in 1974, acupuncture (AP) has received greater acceptance by veterinary professionals throughout the world. This article introduces some important animal diseases that respond well to AP therapy. These include resuscitation of small animals, treatment of anoestrous gilts and sows, bovine reproductive disease, canine vertebral problems and equine backpain, etc. Conventional medicine considers these to be difficult cases to treat. Veterinarians have become more aware of the benefits of AP especially for those diseases, thanks to the efforts of experienced practitioners and scientists, and the many published reports on veterinary AP that have introduced some good indications for AP therapy in veterinary practice. Possible mechanisms behind the effectiveness of AP are discussed. This article aims to introduce veterinarians to good indications for AP to initiate their interest in the practice of AP. Although this is a rapidly expanding field, a long march must begin with one step. We wish this article to be the shoes for such a march. For more information on veterinary AP, contact IVAS , P.O. Box 1478, Longmont, CO.. 80502, USA (http://www.ivas.org), or your national veterinary acupuncture society (http://www.komvet.at/ ivadkom/vapsocs.htm).     

水稻畦式好气栽培法试验

以传统栽培为对照,研究畦式好气栽培对水稻根系、群体消长、产量构成因素及产量的影响。结果表明,畦式好气栽培显著提高了整个生育期水稻根系的生物量,与传统栽培相比,增幅达5.46%－11.18%;显著增加了抽穗后10cm以下土层的根系比例和根系活力,提高了根冠比,促进了水稻分蘖的发生,显著提高了水稻有效穗数、结实率和产量,每公顷可比传统栽培增产稻谷637.5kg,增产9.48%。     

Anesthesia for neonatal foals

A brief discussion of those aspects of neonatal physiology that pertain to anesthetic risk and selection of anesthetic techniques is followed by discussion of suggested techniques for anesthetic management in healthy foals. Preoperative preparation and management of foals with selected serious surgical conditions are also considered.     

Acid-induced autoagglutination found in chicken pathogenic Escherichia coli strain.

Chicken pathogenic Escherichia coli strains were found to autoagglutinate in a static culture of trypticase soy broth (TSB). One strain, designated PDI-386, was further studied for its autoagglutinating property. Acidity in the cultured medium caused by glucose degradation induced the autoagglutination. The bacterial cells grown in a glucose-free L-broth could be aggregated by adding acid, which suggests a potentiality of autoagglutination of the strain grown in the L-broth. The autoagglutinating parent (Agg) formed small colonies with irregular edges like rough colonies on the TS agar, whereas its non-autoagglutinating variant (Nag) formed larger smooth colonies with a perfectly round edge. The Nag colony was easily generated from the Agg colony on the TS agar. The autoagglutinating property was very unstable when the bacteria was passed in the TSB, but rather stable in the L-broth. Under electron microscope, the Agg were found to possess pili of more than 20 microns in length. However, the phenotypic expression of autoagglutination did not correlate with that of mannose-sensitive hemagglutination against guinea pig erythrocytes. Incubation of the Nag in the L-broth at room temperature for more than 10 days provoked the reversion of the autoagglutination. There was no difference between the Agg and the Nag in terms of surface hydrophobicity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of membrane proteins and LPS, and plasmid profiles. The virulence of the Agg was higher than that of the Nag. The autoagglutination property is, however, so unstable that the pathogenicity of E. coli isolates from chickens should be carefully evaluated.     

Estrogen and progesterone receptor status of mammary carcinomas and correlation with clinical outcome in dogs.

Estrogen and progesterone receptors (ER, PR) were measured in cytosol fractions from 18 primary canine mammary carcinomas by use of biochemical assays. One or both receptors were detected (> 10 fmol/mg of cytosol protein) in 11 tumors: 5 ER and PR; 2 ER only; 4 PR only. Mean cytoplasmic receptor concentrations (fmol/mg of cytosol protein) were 22.8 +/- 2.9 (SEM) for ER and 51.0 +/- 10.3 for PR in tumors containing ER and PR, 28.8 +/- 12.1 for ER in tumors containing only ER and 13.2 +/- 1.5 for PR in tumors containing only PR. Estrogen or progesterone receptors or both were identified in 6 of 9 tubular adenocarcinomas, 4 of 5 papillary adenocarcinomas, and 1 of 1 squamous cell carcinoma. These receptors were not identified in solid carcinomas (n = 2) or a single spindle cell carcinoma. Although the number of cases was limited, survival times of dogs tended to be longest in those with tumors containing ER alone or in combination with PR, intermediate in those with tumors containing only PR, and shortest in those with tumors without ER or PR. A correlation was not apparent between receptor status and age, presence of ovaries, tumor size, or histologic classification of the tumor. In the analysis of this series, the extent of surgery (mastectomy of the involved gland vs unilateral or bilateral mastectomy) did not appear to influence the outcome of the disease, and metastasis to regional lymph nodes did not appear to be a reliable prognostic indicator.