U/Pb zircon geochronology and tempo of the end-permian mass extinction

The mass extinction at the end of the Permian was the most profound in the history of life. Fundamental to understanding its cause is determining the tempo and duration of the extinction. Uranium/lead zircon data from Late Permian and Early Triassic rocks from south China place the Permian-Triassic boundary at 251.4 +/- 0.3 million years ago. Biostratigraphic controls from strata intercalated with ash beds below the boundary indicate that the Changhsingian pulse of the end-Permian extinction, corresponding to the disappearance of about 85 percent of marine species, lasted less than 1 million years. At Meishan, a negative excursion in delta13C at the boundary had a duration of 165,000 years or less, suggesting a catastrophic addition of light carbon.     

两种人工栽培藏茵陈生物学特性的研究

通过椭圆叶花猫（Halenia elliptica D．Don）、四数獐牙菜（Swertia tetraptera maxim）的人工栽培试验表明：两种藏茵陈植物都为两年生草本，第一年仅以叶簇形态生枝条不伸长，只进行营养生长，生长第二年枝条才开始伸长，开花结实后完成生活史；两种藏茵陈播种时间都以秋播为宜，有利于自然通过低温春化作用打破种子休眠，促进翌年春天种子萌发，显著提高田间出苗率；两种藏茵陈通过人工栽培，其茎、叶都比野生植物生长高大、粗壮，可大幅提高生药产量，是保护珍稀野生植物资源的有效途径之一；两种藏茵陈50％以上的种子在土壤中有较长期的休眠特性，一般在一年中的春秋两季萌发，所以适当增加播种量第二年后可使田间一年、二年生植株同时生长，对生药生产可连年持续收获产品，免去了对土壤的耕、翻、耙、种等作业，从而可有效降低栽培成本。     

天麻高产栽培配套技术

本文在试验的基础上 ，结合生产实际，总结出了克服天麻无性繁殖中麻种退化，实现天麻高产稳产的配套栽培技术。     

Effect of 0.1, 0.2, 0.4, and 0.8 mg kg−1 of intravenous butorphanol on thermal antinociception in cats

Many cats do not receive analgesics for treatment of perioperative pain, but when they do, the opioid agonist–antagonist butorphanol (B) is widely used. B is reported to provide long‐lasting visceral analgesia, but its somatic actions are not well documented. This study aimed to assess B by using a thermal threshold (TT) model. Six cats (four spayed females, two castrated males, 4.4–6.9 kg) participated in the study. The day before each study, the lateral thorax of each of the cats was shaved and a cephalic catheter was placed. TT was measured using a thermal threshold testing device specifically developed for cats. A heater element and temperature sensor housed in a small probe was held against the cat's thorax with an elastic band and pressure bladder to assure consistent contact. Skin temperature was recorded before each test, then the heater was activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature recorded. A cut‐out temperature was set at 55.5 °C. Three baseline measurements were recorded before IV injections of 0.1, 0.2, 0.4, or 0.8 mg kg^?1 of B. Each cat received all doses in a randomized order at least 1 week apart, and the investigator was blinded to the treatments. TT was measured at every 15 minutes for 6 hours. Data were analyzed using a three‐factor anova , and the critical mean difference was calculated. Pre‐treatment threshold was 40.8 ± 2.25 °C in all cats. There was a significant increase in threshold in all groups from 15 to 90 minutes, but no dose‐related differences were observed. Peak threshold achieved was 48.35 °C, 60 minutes after 0.4 mg kg^?1 of B was injected. Mydriasis was present in all cats after treatment, and many exhibited dysphoric behavior. In this model, B had a short duration of action and no dose–response relationship. Compared to other opioids tested under similar conditions, the intensity of the effect of B was small and of shorter duration.     

Sulfur-associated polioencephalomalacia in cattle grazing plants in the Family Brassicaceae

Polioencephalomalacia was diagnosed histologically in cattle from two herds on the Darling Downs, Queensland, during July–August 2007. In the first incident, 8 of 20 18-month-old Aberdeen Angus steers died while grazing pastures comprising 60% Sisymbrium irio (London rocket) and 40% Capsella bursapastoris (shepherd's purse). In the second incident, 2 of 150 mixed-breed adult cattle died, and another was successfully treated with thiamine, while grazing a pasture comprising almost 100% Raphanus raphanistrum (wild radish). Affected cattle were either found dead or comatose or were seen apparently blind and head-pressing in some cases. For both incidents, plant and water assays were used to calculate the total dietary sulfur content in dry matter as 0.62% and 1.01% respectively, both exceeding the recommended 0.5% for cattle eating more than 40% forage. Blood and tissue assays for lead were negative in both cases. No access to thiaminase, concentrated sodium ion or extrinsic hydrogen sulfide sources were identified in either incident. Below-median late summer and autumn rainfall followed by above-median unseasonal winter rainfall promoted weed growth at the expense of wholesome pasture species before these incidents.     

Identification of equine herpesvirus 3 (equine coital exanthema virus), equine gammaherpesviruses 2 and 5, equine adenoviruses 1 and 2, equine arteritis virus and equine rhinitis A virus by polymerase chain reaction

OBJECTIVE: To develop rapid (< 8 hour) tests using polymerase chain reaction (PCR) for the diagnosis of equine herpesvirus 3 (EHV3; equine coital exanthema virus), equine gammaherpesviruses 2 (EHV2) and EHV5, equine adenovirus 1 (EAdV1), EAdV2, equine arteritis virus (EAV), equine rhinitis A virus (ERAV; formerly equine rhinovirus 1) DESIGN: Either single round or second round (seminested) PCRs were developed and validated. METHODS: Oligonucleotide primers were designed that were specific for each virus, PCR conditions were defined and the specificity and sensitivity of the assays were determined. The application of the tests was validated using a number of independent virus isolates for most of the viruses studied. The PCRs were applied directly to clinical samples where samples were available. RESULTS: We developed a single round PCR for the diagnosis of EHV3, a seminested PCR for EHV2 and single round PCRs for EHV5, EAdV1, EAdV2 and RT-PCRs for EAV and ERAV. The PCR primer sets for each virus were designed and shown to be highly specific (did not amplify any recognised non-target template) and sensitive (detection of minimal amounts of virus) and, where multiple virus isolates were available all isolates were detected. CONCLUSION: The development and validation of a comprehensive panel of PCR diagnostic tests, predominantly for viruses causing equine respiratory disease, that can be completed within 8 hours from receipt of clinical samples, provides a major advance in the rapid diagnosis or exclusion diagnosis of these endemic equine virus diseases in Australia.     

Production of Oocytes of Nile Tilapia (Oreochromis niloticus) for In Vitro Fertilization via Hormonal Treatments

Only a few studies have described hormonal treatments for induction of synchronicity and gamete collection in Nile tilapia (Oreochromis niloticus), both important for assortative matings in breeding programmes and essential for polyploidy technologies. In this study, we compared the effectiveness of carp pituitary extract (CPE), Nile tilapia pituitary extract (TPE), human chorionic gonadotropin (hCG) and gonadotropin‐releasing hormone (GnRH) protocols on the induction of spawning and egg production in Nile tilapia. Among the hormonal treatments analysed, only hCG was effective for producing viable gametes for in vitro fertilization. To verify the viability of this hormonal treatment, hCG was tested using different doses (1000, 2000, 3000, 4000 and 5000 IU/kg) in a large number of females (208 animals) from two Nile tilapia lines. The results indicated that hCG doses between 1000 and 5000 IU/kg could be used to induce final oocyte maturation in Nile tilapia with collection of stripped oocytes. This is the first study to report differential reproductive responses to hormonal treatment between tilapia lines: line 1 was more efficient at producing eggs and post‐hatching larvae after hCG induction than line 2. In conclusion, we demonstrated that the hCG protocol may be applied on a large scale to induce final oocyte maturation in Nile tilapia. The development of a protocol for in vitro fertilization in Nile tilapia may aid in breeding programmes and biotechnological assays for the development of genetically modified lines of Nile tilapia.     

昭通黄牛遗传资源调查报告

[目的]为全面掌握昭通黄牛资源状况,做好该品种的保护和开发利用工作.[方法]调查按国家畜禽遗传资源管理委员会<畜禽遗传资源调查技术手册>技术规范执行,采用普查,实地走访、观察、抽样测定,查阅相关文献资料等方式,了解产区概况、品种来源与发展方向、外貌特征、体尺体重、生产性能、饲养方式、繁殖性能等,并进行综合评定.[结果]昭通黄牛具有体质健壮、肉质良好、抗旱耐湿、耐粗抗病、性情温顺、适应性强、行动敏捷、产肉性能好、皮板质量优良等特点,但自20世纪80年代以来,随着外引牛冻精开展肉用杂交面的扩大,纯种数量逐年减少,产区各地都在强行对昭通黄牛公牛实行阉割,致使该品种正以地区级的规模被取代.[结论]昭通黄牛属于南方黄牛,是云南黄牛的三个地方类群之一,屠宰率和净肉率高于本省的其他品种牛,其具有较高的遗传变异和丰富的遗传多样性,同时与瘤牛发源息息相关,有特殊的起源地位,选育、保种工作亟待重视和加强.