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

A. Bhogal  A. Bhogal  M.A. Shepherd  D.J. Hatch  L. Brown  S.C. Jarvis 《Soil Use and Management》2001,17(3):163-172

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.  相似文献   

Factors Affecting the use of Dreissena polymorpha as a Bioindicator: the PCB Pollution in Lake Como (N. Italy)     

A. Binelli  S. Galassi  A. Provini 《Water, air, and soil pollution》2001,125(1):19-32

The aim of this study was to assess the PCB pollutionof the South-Western branch of Lake Como by using thezebra mussel (Dreissena polymorpha) as abioindicator since its recent reintroduction. Someenvironmental and physiological variables influencingaccumulation processes of organochlorine compounds inDreissena were investigated because climaticfactors may affect life cycle, reproductive stage andage. PCB levels were highest in the soft tissues ofDreissena close to the industrialized area ofComo (2298 ng g^-1 of lipids) and slowly decrease goingnorth, reaching approximately half this value at theclosing section of the lake branch. Nonetheless, thePCB concentrations are well below the dangerous levelsfor the aquatic environment.  相似文献   

COMPUTED TOMOGRAPHIC IMAGING OF INFILTRATIVE LIPOMA IN 22 DOGS     

Margaret C.  McEntee  DVM  Donald E.  Thrall  DVM  PhD 《Veterinary radiology & ultrasound》2001,42(3):221-225

Twenty two dogs with an infiltrative lipoma had computed tomographic (CT) images acquired to evaluate the extent of local disease. Ten dogs had undergone at least one cytoreductive surgical procedure (range = 1-3; median = 2) prior to imaging. Twenty dogs had measurable disease on CT images; 2 dogs had diffuse disease at a previous surgical site that could not be measured. Tumor volume (n = 20) ranged from 20 to 5,632 cm3 (median = 345 cm3; mean = 996 cm3). None of the dogs had evidence of bone involvement on the CT images; 2 of the 22 dogs had tumors that did not come into direct contact with osseous structures. All dogs with measurable disease had evidence of a fat opacity mass with variable degrees of muscle infiltration. Eleven of 22 dogs were given intravenous contrast medium prior to image acquisition and there was not evidence of enhancement of the infiltrative lipoma in any dog. Based on CT images, tumors were classified as well-defined in 9 dogs, moderately well-defined in 4, not well-defined in 3 and a mix of well-defined and not well-defined in 6 dogs. Tumors tended to be less well-defined in regions where the infiltrative lipoma interdigitated with normal body fat. It appears CT imaging allows adequate discrimination of tumor with the caveat that differentiation of normal fat from infiltrative lipoma can be problematic.  相似文献   

Acupuncture for general veterinary practice.     

W W Chan  K Y Chen  H Liu  L S Wu  J H Lin 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(10):1057-1062

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).  相似文献   

Efficacy and safety of an infectious bursal disease virus intermediate vaccine in ovo.     

M Coletti  E Del Rossi  M P Franciosini  F Passamonti  G Tacconi  C Marini 《Avian diseases》2001,45(4):1036-1043

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鸡的微卫星DNA标记与胴体性状的相关分析   总被引：4，自引：1，他引：3  

陈晖  郑丽祯  陈岩锋  郑嫩珠  缪中纬  陈宽维  汤青萍 《中国家禽》2004,8(Z1):137-140

测定了青脚麻鸡与隐性白鸡杂交后自交的F2代个体的全净堂重、全净堂率、脂肪宽带、腹脂重和腹脂率6个胴体性状,检测10个微卫星DNA标记,对标记基因型胴体性状值进行方差分析和多重比较,结果表明:MCW328对于10周龄体重和全净膛重两性状各基因型均有显著的差异(P<0.05);ADL292对于腹脂重性状各基因型有极显著的差异(P<0.01),对于腹脂率有显著的差异(P<0.05)。MCW328标记基因与控制10周龄体重和全净膛重QTL连锁,ADL292标记基因与控制腹脂重和腹脂率QTL连锁。  相似文献   

杨梅袋苗大棚嫁接及管理技术     

郑友明 《福建果树》2004,(4):48-48

杨梅是我国的特产水果，福建的“浮宫杨梅”以成熟期国内最早、色泽紫红、酸甜适口而受到广大消费者的青睐，果品销往国内各大城市和东南亚地区，2004年首次出口到欧盟，市场前景广阔。杨梅传统的繁殖采用大苗嫁接法，即先在定植穴种实生苗，2～3年或更长时间后再进行嫁接。  相似文献   

Sinnesphysiologische Untersuchungen an Schmetterlingsraupen und ihre praktische Bedeutung     

B. Götz 《Journal of pest science》1938,14(8):92-93

Ohne Zusammenfassung  相似文献   

    

Fr. 《Journal of pest science》1941,17(2):24

Ohne Zusammenfassung  相似文献   

Star catalogues     

I HC 《Science (New York, N.Y.)》1885,6(144):408-409

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