广西泥盆纪早埃姆斯期郁江组Heterophaulactis Yu,1974的再研究

Heterophaulactis Yu是作者建立并发表于1974年的一四射珊瑚属,产自广西郁江沿岸、南宁至六景一带的泥盆纪郁江组,其时代属早埃姆斯期牙形刺kitabacus带(前dehiscens带)。对此珊瑚属再行研究,是出于:1)发表在中国南方泥盆系的新进展一文,是与其它门类化石共同作为划分和对比地层的化石依据,只限于中文简短描述,对化石图影的展示也有严格的数量限制。尽管此属己被收录在Hill(1981)主编的古生物专论的珊瑚分册中,也只是简短的英文描述和有限的图影,未能充分展示其骨骼演变特征;2)此属的分类位置、科的归属及与相关属的属征比较与讨论,当初均未交待,应予阐明;3)Heterophaulactis属的地理分布广,遍及滇桂两省,通过再研究,其产地已扩展至中国西北地区;其地层分布又有一定的时限性,在广西仅限于郁江组下部的石州段,时代为kitaba-cus带,其它地区也仅见于下泥盆统。文中对Heterophaulactis属的模式种,Heterophaulactis semicrassa的骨骼特征及个体发育过程中的演变均作详细的英文描述和图影展示;与相关属比较之后,认为与本属关系最为密切的是产于西秦岭山区下泥盆统、发表在西北区化石图册上的有些属种,其中的有些属种可以归于本属。文中还记述一新建种Heterophaulactis yujiangense sp.nov.。文章对Heterophaulactis的分类位置和科的归属也有详细比较讨论,认为它是源出自志留纪Pycnactis—Phaulactis的演化序列,应归属于Lykophyllidae Wedekind,1927科。对Miroelasmatinae Cao,1983亚科的原始定义作全面修订后,把它归为Lykophyllidae Wedekind,1927科下的一个亚科;在对化石图册及相关文献上记述的产自西秦岭区下泥盆统四射珊瑚属种的全面修订之前,暂把以下各属置于此亚科:Heterophaulactis Yu,Miroelasma Cao,Qinlingophyllum Cao,Wenxianophyllum Cao,Protaulacophy-llum Cao,Bethanyphyllum sensu Cao,Aulacophyllum sensu Cao和Aulacophyllum sensu Zhang。     

Divergence of the phytochrome gene family predates angiosperm evolution and suggests thatSelaginella andEquisetum arose prior toPsilotum

Thirty-two partial phytochrome sequences from algae, mosses, ferns, gymnosperms, and angiosperms (11 of them newly released ones from our laboratory) were analyzed by distance and characterstate approaches (PHYLIP, TREECON, PAUP). In addition, 12 full-length sequences were analyzed. Despite low bootstrap values at individual internal nodes, the inferred trees (neighbor joining, Fitch, maximum parsimony) generally showed similar branching orders consistent with other molecular data. Lower plants formed two distinct groups. One basal group consisted of Selaginella, Equisetum, and mosses; the other consisted of a monophyletic cluster of frond-bearing pteridophytes. Psilotum was a member of the latter group and hence perhaps was not, as sometimes suggested, a close relative of the first vascular plants. The results further suggest that phytochrome gene duplication giving rise to a- and b- and later to c-types may have taken place within seedfern genomes. Distance matrices dated the separation of mono- and dicotyledons back to about 260 million years before the present (Myr b.p.) and the separation of Metasequoia and Picea to a fossil record-compatible value of 230 Myr B.P. The Ephedra sequence clustered with the c- or a-type and Metasequoia and Picea sequences clustered with the b-type lineage. The paleoherb Nymphaea branched off from the c-type lineage prior to the divergence of mono- and dicotyledons on the a- and b-type branches. Sequences of Piper (another paleoherb) created problems in that they branched off from different phytochrome lineages at nodes contradicting distance from the inferred trees' origin. Correspondence to: H.A.W. Schneider-Poetsch     

Monitoring bird migration with a fixed-beam radar and a thermal-imaging camera

ABSTRACT.   Previous studies using thermal imaging cameras (TI) have used target size as an indicator of target altitude when radar was not available, but this approach may lead to errors if birds that differ greatly in size are actually flying at the same altitude. To overcome this potential difficulty and obtain more accurate measures of the flight altitudes and numbers of individual migrants, we have developed a technique that combines a vertically pointed stationary radar beam and a vertically pointed thermal imaging camera (VERTRAD/TI). The TI provides accurate counts of the birds passing through a fixed, circular sampling area in the TI display, and the radar provides accurate data on their flight altitudes. We analyzed samples of VERTRAD/TI video data collected during nocturnal fall migration in 2000 and 2003 and during the arrival of spring trans-Gulf migration during the daytime in 2003. We used a video peak store (VPS) to make time exposures of target tracks in the video record of the TI and developed criteria to distinguish birds, foraging bats, and insects based on characteristics of the tracks in the VPS images and the altitude of the targets. The TI worked equally well during daytime and nighttime observations and best when skies were clear, because thermal radiance from cloud heat often obscured targets. The VERTRAD/TI system, though costly, is a valuable tool for measuring accurate bird migration traffic rates (the number of birds crossing 1609.34 m [1 statute mile] of front per hour) for different altitudinal strata above 25 m. The technique can be used to estimate the potential risk of migrating birds colliding with man-made obstacles of various heights (e.g., communication and broadcast towers and wind turbines)—a subject of increasing importance to conservation biologists.     

Nutritional status and mortality of highland children in Nepal: Impact of sociocultural factors

This study investigates the nutritional status of native children in the highlands of Nepal (1,700–3,000 m) and explores the relationship between child mortality and surviving children's nutritional status. A random sample of 145 households from 11 villages in the Koshi Hill Zone in east Nepal was surveyed, and the nutritional status of the 438 children <14 years of age living in these households was assessed by means of anthropometry. We found a severe growth retardation in the Nepalese children compared to lowland reference groups as well as to highland children from the Andes. Child mortality and altitude are not significantly different between higher (Brahman and Chetri) and lower (Baisya and Sudra) caste households. A lower caste status and higher altitude of the household is associated with a significantly better nutritional status in offspring. In multiple regression analyses, improved nutritional status in children is significantly associated with lower caste (P = 0.001), higher altitude (P = 0.009), and less crowding (P = 0.001) but not with sibling mortality (P = 0.11). We thus conclude that nutritional status of children in households in the highlands of Nepal is associated with the household's socioeconomic status and altitude but not with mortality among siblings. © 1996 Wiley-Liss, Inc.     

云南高黎贡山地区蝴蝶群落多样性

位于滇西北的高黎贡山是全球生物多样性研究和保护的热点地区之一, 然而该地区昆虫多样性缺乏系统调查和总结。本研究聚焦蝴蝶类群, 考虑该区域高山峡谷特点, 结合海拔梯度、生境类型和季节变化, 采用样线法调查、分析蝴蝶物种多样性及群落结构变化。结果显示: 共观测记录到蝴蝶2,055只, 隶属于5科85属151种, 在历史记录上新增27种, 使该地区已知蝴蝶种类达488种; 其中蛱蝶科物种多样性最高, 灰蝶科次之, 凤蝶科最低。蝴蝶群落多样性分析结果表明: 中海拔1,000-2,000 m区域种类丰富、多样性指数最高; 低海拔区蝴蝶分布明显聚集, 并且与高海拔地区空间上分离, 少有重叠。该地区不同生境中蝴蝶的种类及数量差异也较大, 物种数及多样性指数在自然保护区最高、边缘交错带居中及农业种植区最低。此外, 蝴蝶的种类和数量也存在季节差异, 春季调查到的个体数少, 夏季观察到的物种数少, 两年秋季调查到的物种丰富度、多样性均高, 但存在季节内变化。总之, 高黎贡山地区不同海拔、生境、季节间和季节内蝴蝶群落组成有自身特点, 共存物种有限, 蝴蝶群落相似性低。综合评估分布于该地区的蝴蝶保护种类, 包括易危种17种、近危种50种, 有国家二级保护蝴蝶3种。本研究弄清了高黎贡山地区蝴蝶的物种本底, 并调查获得其多样性随海拔、生境和季节变化的模式, 为加强区域物种多样性监测、保护生物多样性提供了科学依据。     

昆明地区下寒武统节肢动物Guangweicaris Luo,Fu et Hu,2007的再研究

昆明地区下寒武统沧浪铺组乌龙箐段所产的节肢动物Guangweicaris Luo,Fu et Hu,2007,为研究寒武纪生命大爆发之后节肢动物辐射特征提供了重要资料。罗惠麟等(2007)在报道该节肢动物时,因标本不完整,对其头部和尾部特征均作了错误鉴别和描述。笔者根据完整且保存有软体附肢的标本,对Guangweicaris Luo,Fu et Hu,2007作了重新研究和复原,据此讨论了该节肢动物的分类归属问题。     

秦岭南坡不同海拔林分凋落叶分解特征

采用野外放置凋落物分解袋法,对秦岭南坡林区不同海拔华山松(Pinus armandii)、油松(P.tabulaeformis)、锐齿栎(Quercus aliena var.acuteserrata)和华北落叶松(Larix principis-rupprechtii)凋落叶分解过程中N、P、C、粗脂肪、粗纤维和热值的变化规律进行比较研究.结果表明:(1)处于不同海拔的同一树种新鲜凋落叶的N、P、C、粗脂肪含量及其热值差异不显著(P＞0.05).(2)在一年的分解过程中,凋落叶N、P含量表现出逐渐富集的趋势,其中油松凋落叶N、P富集速度最快,分别达到165.60%和189.94%;凋落叶C、粗脂肪含量和热值、C/N、C/P、粗纤维/N在分解中逐渐下降,粗脂肪释放速率达到50.29%～77.82%.(3)分解一年后,不同海拔同一树种凋落叶N、P、C、C/N、C/P含量仍未表现出显著性差异(P＞0.05),但不同海拔凋落叶粗脂肪分解表现出极显著差异(P＜0.01),其中差距最大的锐齿栎凋落叶低海拔较高海拔粗脂肪释放率高19.38%;不同海拔华北落叶松和锐齿栎凋落叶粗纤维释放速率差异极显著(P＜0.01),而不同海拔油松、华山松凋落叶粗纤维释放无显著差异;处于高低海拔的华北落叶松和锐齿栎凋落叶热值分别为17.12和15.68 kJ·g-1、17.74和13.51 kJ·g-1,表现出极显著差异(P＜0.01),油松、华山松凋落叶表现出显著差异(P＜0.05).研究发现,一年中海拔差异所造成的降水、温度等因素的变化对各树种凋落叶中N、P、C的释放无显著影响,但对凋落叶分解过程中粗脂肪、热值、粗纤维/N的变化影响显著.     

2型糖尿病患者血糖波动与心律失常和下肢血管病变的关系及其影响因素分析

目的:探讨2型糖尿病(T2DM)患者血糖波动与心律失常和下肢血管病变的关系,分析影响T2DM心律失常和下肢血管病变的因素.方法:选择2019年7月到2020年6月我院收治的82例T2DM患者,根据是否合并心律失常分为心律失常组28例和无心律失常组54例,根据是否合并下肢血管病变分为下肢血管病变组31例和无下肢血管病变组...     

西藏米拉山白桦种群生物量和生长量研究

在区域样地调查基础上,通过解析木分析,比较了不同坡向、不同海拔的白桦种群生物量和生长量．结果表明,米拉山白桦种群的生产量约在363．1～2072．94kg·hm^-2·年^-1之间;各种群的现存生物量在7625．00-33167．00kg·hm^-2之间,种群间生物量差异显著．砍伐后的白桦萌生木、生物量和生长量均小于实生木。并且在生长过程中出现早衰的现象,表明人类活动的干扰对白桦种群有较大影响．米拉山东、西坡不同海拔生境条件下,水分地带性的变化对白桦各器官内的水分分配以及生物量组成没有显著影响．     

2型糖尿病患者下肢血管病变的危险因素分析

目的:探讨2型糖尿病患者发生下肢血管病变的危险因素.方法:回顾性分析我院2009年12月～2011年12月收治的98例2型糖尿病患者的临床资料,通过彩色多普勒超声检查其下肢血管,按下肢血管有无病变将其分为单纯2型糖尿病租和2型糖尿病合并下肢血管病变组,通过非条件Logistic回归分析导致2型糖尿病患者发生下肢血管病变的危险因素.结果:彩色多普勒超声检查结果显示,98例2型糖尿病患者中,61例发生不同程度下肢血管病变,占62.24％.与单纯2型糖尿病组比较,下肢血管病变组患者年龄、病程、收缩压及低密度脂蛋白胆固醇的差异均有统计学意义(P＜0.05),经非条件Logistic回归分析,患者的年龄、病程、SBP及LDL-L是下肢血管病变的独立危险因素(P＜0.05).结论:2型糖尿病患者下肢血管病变的发生与患者的年龄、病程、血压及血脂情况密切相关.