Feeding behaviour of yaks on spring, transitional, summer and winter pasture in the alpine region of the Qinghai-Tibetan plateau

Of the present estimated world population of 14.2 million yaks, approximately 13.3 million occur within Chinese territories (Food and Agriculture Organization of the United Nations, 2003). Although there is an extensive bibliography covering the species, few studies have been conducted in the area of foraging behaviour. The present study was conducted at pasture during the spring, transitional, summer and winter seasons to determine the daily temporal patterns of grazing and ruminating behaviour by yaks. During each study period, two 24 h recordings were undertaken with each of six mature dairy yaks. One study period was conducted on each of the transitional, summer and winter pastures, whereas, due to the considerable changes occurring in the morphology of the spring pasture, three separate studies were completed during March, April and May. During the second of these studies (April), the effect of level of concentrate supplementation on grazing and ruminating behaviour was also examined. Behaviour recordings were made using solid-state behaviour recorders. Short-term intake rates (IR, g min(-1)) were calculated by weighing yaks before and after approximately 1 h of grazing, retaining the faeces and urine excreted and applying a correction for insensible weight loss. Yaks spent less time grazing during the dry season (the early period on the spring pasture) compared with the later green swards (the later period on the spring pasture, the transitional pasture and the summer pasture) (P < 0.05). When the forage quality improved, but there was still insufficient mass (the later period on the spring pasture), the yaks extended their grazing time at the expense of other activities. During the early periods on the spring pasture, the short-term IR by yaks was up to 53 g DM min(-1), significantly higher than at other times (P < 0.05). The level of concentrate offered had little or no effect on grazing or ruminating time. The total eating time of the yaks offered 0.5 or 1.0 kg concentrate was 2.9 and 4.5 h day(-1) respectively, significantly lower than unsupplemented yaks (6.8 h) (P < 0.05). In general, yaks can regulate their foraging behaviour according to the changes of sward conditions in order to achieve optimal grazing strategies. (C) 2007 Published by Elsevier B.V.

Seasonal thermogenesis and body mass regulation in plateau pikas (Ochotona curzoniae)

Changes in photoperiod, ambient temperature and food availability trigger seasonal acclimatization in physiology and behavior of many animals. In the present study, seasonal adjustments in body mass and in several physiological, hormonal, and biochemical markers were examined in wild-captured plateau pikas (Ochotona curzoniae) from the Qinghai-Tibetan plateau. Our results showed that plateau pikas maintained a relatively constant body mass throughout the year and showed no seasonal changes in body fat mass and circulating levels of serum leptin. However, nonshivering thermogenesis, cytochrome c oxidase activity, and mitochondrial uncoupling protein 1 (UCP1) contents in brown adipose tissues were significantly enhanced in winter. Further, serum leptin levels were positively correlated with body mass and body fat mass while negatively correlated with UCP1 contents. Together, these data suggest that plateau pikas mainly depend on increasing thermogenic capacities, rather than decreasing body mass, to cope with cold, and leptin may play a potential role in their thermogenesis and body mass regulation.

Analysis of high wheat yields in Northwest China

Grain yields of over 14 Mg ha(-1) were reported in 1978 for spring wheat (Triticum aestivum L.) grown in Northwest China. Understanding the circumstances under which this record yield was achieved may be useful in defining the key factors that lead to high grain yields and in determining the limits to wheat yield. A relatively simple, mechanistic model was used in an effort to simulate the record yield. The model was used as a framework in which various crop traits could be adjusted to match the observed crop growth. The weather that was characterized by cool temperatures and high levels of solar radiation, proved to be especially important in allowing a full-season crop to achieve record yields. Variables defining plant development in the model also had to be set to describe the high yielding cultivar grown in China. Leaf development was defined by the length of a phyllochron, which was set equal to 78 TU (thermal units, base temperature equal to 0 degrees C) based on independent data. The description of grain fill had to be defined to match simulation results with the observations. Two variables, length of the grain-fill period and the grain growth rate, were set in response to the unique traits of this cultivar and the low temperatures during grain development. These simulations led to important suggestions for examining the interaction between cool temperature regimes and developmental traits of wheat cultivars. (C) 1997 Published by Elsevier Science Ltd.

迤纳厂稀土铁铜矿床稀土元素地球化学

系统测定了迤纳厂矿床不同类型矿石、围岩和火山角砾岩、岩浆岩的稀土元素组成。研究表明，不同类型矿石均具REE总量高(726X10^6—4633x10^6)、铕正异常(1．邱一5．16)、轻稀土强烈富集[(La／Yb)n=3．98—81．1]等特征，Y／Ho比值(24．4)小于球粒陨石中比值(28)，与黑烟囱的比值接近。硅质白云岩及钠长石英斑岩、层状火山角砾岩的稀土特征(稀土总量低，铕负异常，轻重稀土分异不明显等)与矿石完全不同。成矿流体的稀土元素特征与现代大洋中脊热液相似，与裂谷初期的碱性火山岩稀土元素特征较为接近。结合矿床产出的大地构造背景，提出迤纳厂稀土铁铜矿床可能为昆阳裂谷初期碱性火山岩的喷发期间歇，来自地幔富稀土、富挥发份的成矿流体喷流．沉积成矿。

贵州早寒武世的缺氧事件沉积

贵州早寒武世的黑色岩系属中国南方该时期缺氧事件沉积的一部分,为一套沉积速率低的海侵体系域沉积.主要为黑色页岩,发育水平纹理,主要含浮游生物,其中产钼、钒等矿床.其具有独特的元素地球化学特征:SiO2、TiO2、Al2O3的含量相对较高;富集Mo、V、Ba、Ag、Au、U等元素,而Co、Sr、Ta等元素却亏损;稀土总量不高,为130×10-5～226×10-6,稀土配分曲线形态近于水平或略向右倾,具弱的负Ce异常和正Eu异常.地层特征、元素地球化学特征及特征元素比值所反映的是早寒武世黑色岩系形成于缺氧的还原环境,而缺氧沉积中有热水沉积的加入.

贵州凉风洞石笋的古气侯记录与古生态环境意义

自20世纪60年代以来，探索全球性气候变化规律和环境变迁史的研究工作在世界各国广泛开展。大规模的深海岩芯的研究、中国北方黄土的系统研究、大型湖泊沉积岩芯的研究及对树木年轮、泥炭、珊瑚、冰芯等“自然环境历史档案”开展的研究工作，都为重建古气候和古生态环境提供了大量的资料。洞穴化学沉积物（石笋）由于其特有的微层结构及其内的稳定氧、碳同位素和微量元素所蕴含的古气候与古生态环境信息，并且具有分布广、时间长、信息保存完整等特点，因此，它是研究地球环境变化很好的自然环境历史档案。本论文通过对凉风洞洞穴体系的综合研究和对凉风洞石笋（微层）生长特征及石笋的碳、氧稳定同位素组成的研究，系统探讨了贵州凉风洞石笋的古气候记录和古生态环境意义，得出以下主要结论：1，地表植被的类型及生物量等信息可综合反映于洞穴体系的不同组．分（气样、土样、水样）中。而洞穴的水动力条件也能很好的被洞穴滴水中所含微量（常量）元素记录。根据分析，洞穴综合体系对外界气候与生态环境的响应关系存在一定规律性。通过对比说明，我们所选的凉风洞基岩的溶蚀和缓冲对水体中的信息影响不大，即洞穴滴水较好的继承了土壤水所携带的地表气候与生态环境信息，是理想的研究对象。2．凉风洞石笋具有多个沉积旋回，不同沉积旋回的纹层组合及纹层结构存在一定的差异，指示不同的沉积环境。根据年龄数据判断，旋回①至旋回⑧之间年龄跨度为1570-8000 aBP，以呈缓平顶（柱）对称叠复状的沉积形态组合为主，示洞顶滴水量较大，滴水点相对稳定，且均匀，与全新世较为稳定的气候与环境变化的主旋律相一致。旋回⑧以下至底部石葡萄状沉积物之上部分之间年龄跨度为8000-14220 aBP，期间经历末次冰期晚期向全新世大暖期过渡，受诸如新仙女木事件（Younger Dryas）等的影响，气候变化幅度大，且经历多次反复，石笋生长的沉积学特征表现为斜锥（柱）、尖顶锥不对称叠复纹层组合，示洞顶滴水水量较小但变化较大，且洞穴滴水不稳（固）定。与此时间段内不稳定的气候与环境变化的主旋律也相一致。3．凉风洞石笋上段微层具有典型南方石笋微层发育的特性：微层发育较差，层面多弯曲，层间界面模糊等。下段因为沉积间断较多、风化层面厚及受到若干时段内碳酸钙重结晶而导致晶体穿插层位生长的影响，尽管在某些层位有微层发育，但无法对石笋微层作连续观察记录。根据高精度的石笋TIMS、ICP-MS测年数据和在显微镜下所数石笋微层数量的对比，扣除若干个沉积间断及风化层导致的微层缺失，以及显微镜下肉眼对细小微层计数的误差，我们认为，凉风洞石笋微层是年生长层的可能性较大。4，由于部分测年数据仍在测试中，目前无法精确控制石笋中沉积间断的存在导致的信息缺失，因此，我们仅仅根据部分石笋测年数据，建立了凉风洞石笋在不同时段的生长速率。全新世以来石笋的生长速率在22μm／yr-51μm／yr之间，明显高于末次冰期晚期向全新世过渡这一时间段内的石笋生长速率（16μm／yr）。这些数据间接印证了石笋生长响应于外界气候，尤其是降雨的变化。5．通过对洞穴体系的综合分析对比，我们判断凉风洞洞穴综合体系相对完整，洞穴化学沉积物的6先值较为直接的响应了土壤c压的61t值变化，即反映了地表的植被（c3植物和c；植物）的组成状况。贵州地区降雨80％集中在5-10月份，在此期间，基本受西南季风和东亚季风所控制。西南季风盛行时贵州各地的降雨频繁，是一年中雨量最集中的时期，在东亚季风影响时期，贵州多晴少雨，往往形成干早的天气。又西南季风控制区大气降雨创的值的加权平均值明显低于东亚季风控制区大气降雨δ18O值的加权平均值。因此，贵州地区年均降雨量和年均降雨δ18O值主要取决于西南（印度洋）季风的强弱：西南季风加强，降雨量增加，年均降雨剐、值偏负；西南季风减弱，降雨量减少，年均降雨δ18O值偏正。洞穴滴水的6旧O值变化基本继承了大气降水的别勿值变化。因此，对地处我国西南地区贵州南部的凉风洞，源于洞穴滴水的凉风洞石笋的别勺值变化直接响应了外界的大气降雨量的变化和西南季风与东亚季风相互的强弱交替。6．对凉风洞石笋碳、氧同位素组成的时间序列曲线作20点移动平均，发现，特别是进入全新世后，石笋的引3c值和扩、值几乎具有完全一致的同步变化，只是在变化幅度上在某些时段存在差异。说明在凉风洞石笋反映的14220-1570 aBP时间段内，尤其是10500-1570 aBP期间，本区域气候具有雨热（或干冷）同期的气候特征：在气温较高时间段，西南季风增强，气候湿润多雨，更有利于地表。植物的生长。气温降低时，随着东亚季风增强，西南季风减弱，气候干旱少雨，地表C；植物的生长占有一定的比例。据此重建和恢复了本地区14220-1570 aBP期间的古气候和古生态环境：（1）．14220-10500aBP，处于末次冰期晚期，气温较低。凉风洞石笋此时段的司、值都大于-9.8‰，最小值为-9.31‰，最大值达-7.290‰，平均值为-8.552‰。说明凉风洞洞穴地表的生长植被。植物占有一定的组分，石笋的δ18C值受C3植物和C4植物的共同影响。此时段内石笋6、值也存在一定的波动（-5.651‰－6.942‰），考虑到末次冰期晚期先全新世过渡期间气温变幅较大，O'Neil等（1969）所建立的氧同位素平衡分馏方程中的温度变化已不能忽略，并且大气降雨的温度效应作用也比较明显，因此我们对此时段的季风和大气降雨量的变化不作讨论。（2）. 10500-9300 aBP，新仙女木事件结束，进入全新世，气温逐渐回升。凉风洞石笋此时段的扩3c值大都小于-9.8‰，最小值为-10.377‰，最大值为-9.267‰，平均值为-9.910‰。凉风洞洞穴地表植被已逐渐由C3植物占主导。此时段石笋δ18C值明显卜降，最小值为-7.420‰，最大值为-6.077‰，平均值为-6.854‰。反映在全新世早期夏季风盛行，降雨量较大，西南季风对本地区全年降雨贡献率大。（3）．9300-8300 aBP，经历一段明显温度波动变化。仟3c值在-9.8‰上下波动，最小值为-10.155‰，最大值为-9.096‰，平均值为-9.712‰。凉风洞洞穴地表植被C4植物所占比例存在反复。此时段石笋岁a0值变化幅度不是很大，最小值为-6.796‰，最大值为-6.260‰，平均值为-6.490‰。受冬季风影响，夏季风有一定的减弱，总体降雨量一般，东亚季风对本地区全年降雨贡献率比全新世初期有所增大。（4）．8300-3l000BP，俗称全新世大暖期，此时段全球气温明显回升，石笋δ18C值总体逐渐降低，最小值为-n．926编，平均值为-10.496‰。凉风洞洞穴地表植被基本由C3植物所控制。但在扩飞值总体逐渐降低的趋势一F，也存在若干扩3c值明显增大时段，如7700-6700 aBP时段，61七值最大值达-8.110‰，地表C4植物所占比例已不能忽略。此时段石笋6150值变化幅度较大，最小值为-7.373‰，最大值为-5.047‰，平均值为-6.261‰。反映在全新世大暖期的大背景下西南季风和东亚季风的交替以及大气降雨量的变化存在较大的波动，说明了季风气候的不稳定性。（5）．3100-1570 aBP，在3100aBP前后，凉风洞石笋的δ18C值和δ18O值均急剧上升，标志进入晚全新世。此时段气温变幅很大，δ18C值总体虽然仍偏低，平均值为-10.275‰，但刻畜介于-6.495-12.097‰之间；δ18C值平均值为-6.184‰，变幅介于-4.677-8.65‰之间，均超过以往任何时段。此时段凉风洞洞穴地表植被基本上仍然由C。植物所控制，始于3100 aBP的急速降温事件使得在全新世晚期开始时段C4植物所占比例有一定的上升。此时段内西南季风和东亚季风反复多次交替，大气降雨量存在较大幅度的变化，说明了季风气候在此时段的很不稳定性。对于169于巧70 oBP百年时间段内石笋的δ18C值和司、值巨大幅度的急剧升高，有待进一步研究，也不排除石笋表层长期裸露受外界污染所致。

Alternative splicing of the FMR1 gene in human tissues of fetal and adult

To study the time- and tissue-specificity of alternative splicing of the FMR1 gene, we analyzed the alternative splicing pattern of the FMR1 gene in human tissues from adult and fetus using RT-PCR coupled with capillary electrophoresis. Seven alternative splicing variants of FMR1 were found in adult liver and lung. The major three alternative splicing variants of the FMR1 gene in all analyzed fetal tissues were same, though the number of minor isoforms and the relative abundance of major isoforms were different. The major difference of the alternative splicing pat tem between adult and fetus was in exon 12 and 17. The results suggest that the alternative splicing pattern of the FMR1 gene is non-tissue-specific in the same developmental stage and a developmental switch may be present.

Crescimento de Eucalyptus benthamii submetido à aplicação de lama de cal e cinza de madeira.

2015

Keats and the Holocaust: Notes towards a post-temporalism

Grovier, Kelly, 'Keats and the Holocaust: Notes towards a post-temporalism', Literature and Theology (2003) 17 (4) pp.361-373 RAE2008

Determinación de la actividad insecticida de Solanum sisymbriifolium, Cestrum parqui y Chenopodium album sobre adultos de Tribolium castaneum (Coleptera, Tenebrionidae)

p.373-377