High temperature effects on gas exchange for the invasive buffel grass (Pennisetum ciliare [L.] Link)     

ERICK DE LA BARRERA  ALEJANDRO E. CASTELLANOS 《Weed Biology and Management》2007,7(2):128-131

Buffel grass was introduced to the Sonoran Desert in the mid-twentieth century, where it has aggressively invaded new areas. Given its ecological success at a place where the air temperature can approach 50°C, the effects of high air temperatures on gas exchange were studied for this species. The carbon dioxide uptake and water use efficiency were maximal at day/night air temperatures of 30/20°C for potted plants, substantially decreasing at higher temperatures until the plants died at 45/35°C.  相似文献   

BOOK REVIEW     

LA Abraham 《Australian veterinary journal》2001,79(1):36-36

The 5-MinuteVeterinary Consult: Canine and Feline . 2nd edn. Tilley LP, Smith FWK, Lippincott Williams & Wilkins  相似文献   

Effect of parasite burden on the detection of Fasciola hepatica antigens in sera and feces of experimentally infected sheep     

Almazán C  Avila G  Quiroz H  Ibarra F  Ochoa P 《Veterinary parasitology》2001,97(2):101-112

The effect of Fasciola hepatica parasite burden on the detection of excretory/secretory (E/S) antigens in sera and feces of experimentally infected sheep was evaluated using a double antibody-based capture enzyme-linked immunosorbent assay (ELISA). Four groups of five sheep each were used. The first three groups were infected with 50, 100 and 200 metacercariae of F. hepatica, and the fourth group remained as non-infected control. On the day of infection and weekly thereafter, serum and fecal samples were taken. ELISA detected F. hepatica E/S antigen levels in serum from the first week post-infection (wpi) and in fecal supernatant from the fourth wpi, which were significantly (p<0.05) higher than controls. F. hepatica eggs were not detected until after the eighth wpi. The correlation between absorbance of E/S antigens in serum with the fluke burden was 0.77 (p<0.0001) and in feces 0.76 (p<0.0001) at 12th wpi. The sensitivity of the assay to detect E/S antigens in serum was 86.6% and in feces 93.3%. It is concluded that the ELISA technique used in this study offers a diagnostic alternative for detecting early infections of F. hepatica in sheep.  相似文献   

Standing Laparoscopic Peritoneal Flap Hernioplasty of the Vaginal Rings does not Modify the Sperm Production and Motility Characteristics in Intact Male Horses     

LA Gracia‐Calvo  LJ Ezquerra  M Martín‐Cuervo  ME Durán  H Tapio  JM Gallardo  FJ Peña  C Ortega‐Ferrusola 《Reproduction in domestic animals》2014,49(6):1043-1048

Laparoscopic hernioplasty techniques have been developed in the recent years to avoid the recurrence of inguinal hernias and to spare the testicles for breeding purposes in stallions. However, there have been no previous comprehensive and systematic studies of the reproductive outcomes and prognoses for stallions after inguinal hernioplasty. Therefore, the objective of this study was to assess the possible effects of one of these techniques (standing laparoscopic peritoneal flap hernioplasty) on the sperm production and motility characteristics of six healthy stallions that received this procedure based on 1‐year follow‐ups. There were no significant differences in the measured sperm variables (assessments based on the DSO, MOT, PMOT, VSL, VCL and VAP) during 1‐year follow‐ups.  相似文献   

大通牦牛推广十年的回顾与展望     

拉环  冯宇诚  马进寿 《中国牛业科学》2014,(2):54-56

从2003年以来青海省大通种牛场开始了较大面积的推广工作,到今年己有10年的推广历史了。对一个新品种大面积推广10年是一个极为重要的时间节点。2005年农业部批准"大通牦牛"为新品种并决定颁发新品种证书。截止2013年前己向青海省6州1地1市39个县累计推广大通牦牛种公牛14 640余头,据2013年不完全统计,大通牦牛后裔在省内推广区达91万头以上。今后必需加快品系繁育提高大通牦牛整体水平;加强核心育种群管理确保种牛质量;加强种公牛的动态溯源管理;组识种牛场技术人员深入推广区,传授良种良养的配套技术和野外冷配技术。  相似文献   

Immune challenge of mating effort: steroid hormone profile,dark ventral patch and parasite burden in relation to intrasexual competition in male Iberian red deer     

Eva DE LA PE A  Jos MARTÍN  Isabel BARJA  Raúl PREZ‐CABALLERO  Isabel ACOSTA  Juan CARRANZA 《Integrative zoology》2020,15(4):262-275

Testosterone secretion may regulate the reproductive effort and the development of sexual traits, but it may also involve costs at the immunological and metabolic levels. However, the evidence for this trade‐off in wild populations is scarce. Cortisol also plays an important role in mediating the reproductive and immune functions. In this study, we analyzed whether the endoparasite burden relates to hormonal levels (fecal testosterone and cortisol metabolites) and/or morphological sexual traits (size of the dark ventral patch, a trait that indicates reproductive effort in males) in male Iberian red deer. For this purpose, we sampled male red deer harvested during hunting actions in 2 types of populations in south western Spain that differed in structure, affecting the level of male–male competition for mates. We used coprological analyses to estimate the parasite burden mainly of gastrointestinal and bronchopulmonary nematodes and of protozoa, and assessed testosterone and cortisol metabolite levels from fecal pellets. We found a positive relationship of host parasitation with both testosterone levels and the size of the dark ventral patch, but these relationships depended on the intensity of male–male competition in the population, being only found under the high‐competition scenario. These results are discussed under the hypothesis of the testosterone immunocompetence handicap, suggesting a cost at the immunological level, and, therefore, higher susceptibility to parasite infection in males that make a greater reproductive effort. However, this effect seems to be modulated by the social environment (male–male competition) that might lead to different optima in testosterone production and sexual trait development.  相似文献   

NEAR's flyby of 253 mathilde: images of a C asteroid     

J Veverka  P Thomas  A Harch  B Clark  JF Bell  B Carcich  J Joseph  C Chapman  W Merline  M Robinson  M Malin  LA McFadden  S Murchie  SE Hawkins  R Farquhar  N Izenberg  A Cheng 《Science (New York, N.Y.)》1997,278(5346):2109-2114

On 27 June 1997, the Near Earth Asteroid Rendezvous (NEAR) spacecraft flew within 1212 kilometers of asteroid 253 Mathilde. Mathilde is an irregular, heavily cratered body measuring 66 kilometers by 48 kilometers by 46 kilometers. The asteroid's surface is dark (estimated albedo between 0.035 and 0.050) and similar in color to some CM carbonaceous chondrites. No albedo or color variations were detected. The volume derived from the images and the mass from Doppler tracking of the spacecraft yield a mean density of 1.3 +/- 0.2 grams per cubic centimeter, about half that of CM chondrites, indicating a porous interior structure.  相似文献   

野生龙葵果中营养成分的研究   总被引：13，自引：0，他引：13  

米拉  杨秋林  那顺孟和  李金梅  阿荣 《内蒙古农业大学学报(自然科学版)》2002,23(1):98-100

本研究对野生龙葵果营养成分进行了比较全面地分析测试，对矿物质及维生素含量进行分析的基础上，对野生龙葵果的其它营养成分进行了分析，并与一些常用果蔬进行了对比研究。结果表明，野生龙葵果含有丰富的营养成分。  相似文献   

云南农业大学信息服务与用户调查研究分析   总被引：4，自引：0，他引：4  

刘敏惠  彭劲  李淑云  苏必霞  赖毅  郝一沁 《云南农业大学学报(自然科学版)》2002,17(2):201-205

 通过对云南农业大学的教师、研究生和本科生的信息需求调查,了解到各类用户利用文献信息的状况和对文献信息的需求,为图书馆开展信息服务提供了依据。  相似文献   

ABSENCE OF GLUCOSE EFFECT ON GASTRO-INTESTINAL PHOSPHATE ABSORPTION     

Perryman JH  DE LA Madrid R  Brooks SC 《Science (New York, N.Y.)》1944,100(2595):271-272

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