旌节花科的分类和系统学研究

旌节花科是东亚特有科，仅有旌节花属1属。本文研究了该科植物的生活习性、外部形态、花粉形态和外壁超微结构以及花器官发生，并根据多个DNA区段的序列探讨了科的系统位置和属下关系。在此基础上，综合各方面的证据，对旌节花科进行了全面的分类学修订，完善了该科的分类系统。主要内容包括： 　　1、习性和外部形态学 　　结合室内标本和野外考察，对旌节花科植物的生活习性、叶、花序、花和果实各个性状的变异式样、变异幅度、变异规律及其相关性进行了深入研究，并讨论了它们的分类学价值。结果表明：叶片形状、叶缘齿、花序下的叶片是否宿存以及花序是否具花序梗等性状在种间变异非常大，单个性状对旌节花属属下分类意义不大;而叶片毛被、脉序和结构，花序长度，花的大小和颜色以及果实大小等性状通常较稳定，可作为旌节花属划分种和变种的重要依据。 　　2、花粉形态学和外壁超微结构 　　在透射电镜下研究了旌节花属5个代表种和1个外类群（Crossosoma californicum）的花粉外壁超微结构，并在扫描电镜下研究了外类群Crossosomataceae 1个代表种（Crossosoma californicum）的花粉形态学特征，结合前人的研究，探讨了上述性状的分类学意义。结果表明：旌节花属植物花粉形态的共同特征是：花粉粒球形或近球形，三孔沟;外壁具穴状纹饰，穴较细小;外壁内壁分层明显，容易区分（柳叶旌节花除外），覆盖层光滑，几无附属物，柱状层明显，穿孔较少，不形成半覆盖层。各种植物花粉外壁超微结构的特征在旌节花属两个组中较一致，但其差异可作为探讨属下种的分类和系统学关系的依据。此外，对旌节花科和Crossosomataceae花粉表面纹饰和外壁超微结构的研究结果提示：这两个科与省沽油科和山茶科厚皮香亚科有较近缘的关系，而不支持这两个科的姐妹群关系。 　　3、花器官发生 　　首次对旌节花属常绿组和落叶组共2个代表种的花器官发生进行了研究，结果表明：该科植物花为功能性单性花，雌雄异株，花发育过程长达10个月，其中2-3个月是冬季休眠期。在花发育早期，雄花和雌花的发育没有差异，花性别的分化发生在花发育后期，即每年春天花开前后的2-3天，雌花中雌蕊的子房开始膨大，柱头伸长，胚珠多数，能育，而雄蕊逐渐干瘪收缩直至最后花粉不育;此时雄花的雄蕊发育良好，花丝粗壮发达，花药饱满，花粉能育，而雌蕊发育逐渐停滞直至败育。花器官发生方式为向心式，发生顺序为：苞片—外轮萼片—内轮萼片—花瓣—外轮雄蕊—内轮雄蕊—雌蕊。花萼4枚，两轮，交互对生，花瓣和雄蕊均4枚一轮几乎同时发生，花瓣覆瓦状排列。旌节花属常绿组和落叶组植物的花器官发生发育过程没有差别。 　　4、基于多个DNA区段序列的系统发育分析 　　首次选取进化速率较快的5个DNA区段：核核糖体ITS区和叶绿体rps16, ndhF，trnL-F及trnS-G-G区段，对旌节花属分别代表常绿组和落叶组的10种2变种及外类群Crossosomataceae和省沽油科3种植物的相关序列进行测定，并将上述序列合并构建系统树。研究结果表明：旌节花科作为一个单系群得到很好的支持。旌节花属落叶组和常绿组的划分在基于ITS、叶绿体4个区段单独分析及联合分析得到的系统树中没有得到支持，表现在该联合分析得到的树的两个分支与该属植物的习性和外部形态特征无关，而与它们的地理分布密切相关：其中一支主要分布在东亚的偏北部，另一支主要分布在东亚的南部地区，常绿和落叶的种类则混合在这两支中。此外，分子序列分析的结果对该属植物的分类、系统关系、起源和该科的系统位置均有重要意义。系统树显示出分布于台湾的S. sigeyosii与分布于日本的早春旌节花聚成稳定的一支，说明前者与后者，而不是与西域旌节花关系密切。叶绿体基因树与核基因树存在冲突，表明该属经历过网状进化。推测变种披针叶旌节花与云南旌节花可能是杂交起源。根据叶绿体rbcL序列得出的系统树显示旌节花科与产北美的Crossosomataceae的姊妹群关系支持率低于50%。基于最大似然树，运用罚分似然法推算出这两个科分化时间为68.25 ± 10.36 MYA，这两者共同与省沽油科近缘。 　　5、分类学研究 　　综合上述研究结果，对旌节花属进行了分类学修订。属下不设立组;确认该属植物有6种6变种，其中中国特有种3个，变种3个。5种5变种被作为新异名，新组合3个，其中2个改级新组合。对西域旌节花、云南旌节花和滇缅旌节花等进行了模式指定。本文还给出了分种和变种检索表、各类群的形态学描述、地理分布图、标本引证和讨论等。 　　

An approach to estimating rockfish biomass based on larval production, with application to Sebastes jordani

An assessment of the total biomass of shortbelly rockfish (Sebastes jordani) off the central California coast is presented that is based on a spatially extensive but temporally restricted ichthyoplankton survey conducted during the 1991 spawning season. Contemporaneous samples of adults were obtained by trawl sampling in the study region. Daily larval production (7.56 × 1010 larvae/d) and the larval mortality rate (Z=0.11/d) during the cruise were estimated from a larval “catch curve,” wherein the logarithm of total age-specific larval abundance was regressed against larval age. For this analysis, larval age compositions at each of the 150 sample sites were determined by examination of otolith microstructure from subsampled larvae (n=2203), which were weighted by the polygonal Sette-Ahlstrom area surrounding each station. Female population weight-specific fecundity was estimated through a life table analysis that incorporated sex-specific differences in adult growth rate, female maturity, fecundity, and natural mortality (M). The resulting statistic (102.17 larvae/g) was insensitive to errors in estimating M and to the pattern of recruitment. Together, the two analyses indicated that a total biomass equal to 1366 metric tons (t)/d of age-1+ shortbelly rockfish (sexes combined) was needed to account for the observed level of spawning output during the cruise. Given the long-term seasonal distribution of spawning activity in the study area, as elucidated from a retrospective examination of California Cooperative Oceanic Fisheries Investigation (CalCOFI) ichthyoplankton samples from 1952 to 1984, the “daily” total biomass was expanded to an annual total of 67,392 t. An attempt to account for all sources of error in the derivation of this estimate was made by application of the delta-method, which yielded a coefficient of variation of 19%. The relatively high precision of this larval production method, and the rapidity with which an absolute biomass estimate can be obtained, establishes that, for some species of rockfish (Sebastes spp.), it is an attractive alternative to traditional age-structured stock assessments.

Distribution and co-occurrence of rockfishes (family: Sebastidae) over trawlable shelf and slope habitats of California and southern Oregon

The rockfishes of the sebastid genus Sebastes are a very important fishery resource off the coasts of California and southern Oregon. How-ever, many of the 54 managed stocks of west coast rockfish have recently reached historically low population levels, leading fishery managers to re-examine current management practices. Management of rockfish stocks as multispecies aggregates, as opposed to independent stocks within the ground-fish fishery, can be more desirable when nontargeted bycatch, discard, and management complexity are considered. Rockfish assemblage structure and species co-occurrences were determined by using data from the Alaska Fisheries Science Center triennial continental shelf bottom trawl survey. The weight of rockfish species in trawl catches was expressed as a catch-per-unit-of-effort (CPUE) statistic, from which species spatial distributions, overlaps, diversity, and richness were analyzed. Multidimensional scaling of transformed CPUE data was employed in indirect gradient and multivariate partitioning analyses to quantify assemblage relationships. Results indicated that rockfish distributions closely match the bathymetry of coastal waters. Indirect gradient analysis suggested that depth and latitude are the principal factors in structuring the spatial distributions of rockfish on trawlable habitat. In addition, four assemblages were identified through the joint evaluation of species’ distributions and multivariate partitioning analyses: 1) deep-water slope; 2) northern shelf; 3) southern shelf; and 4) nearshore. The slope, shelf, and near-shore groups are found in depth ranges of 200–500 m, 100–250 m, and 50–150 m, respectively. The division of northern and southern shelf assemblages occurs over a broad area between Cape Mendocino and Monterey Canyon. The results of this analysis are likely to have direct application in the management of rockfish stocks off the coasts of southern Oregon and California.

Land surface hydrology in a general circulation model: global and regional fields needed for validation

For the last two decades most general circulation models (GCMs) have included some kind of surface hydrology submodel. The content of these submodels is becoming increasingly complex and realistic. It is still easy to identify defects in present treatments. Yet, to improve our ability to model the contribution of land hydrology to climate and climate change, we must be concerned not with just the surface hydrology submodel per se, but also with how it works in the overall context of the GCM.

Bias-dependent recovery time of all-optical resonant nonlinearity in InGaAsP/InGaAsP MQW waveguide

We have investigated a resonant refractive nonlinearity in a semiconductor waveguide by measuring intensity dependent phase shifts and bias-dependent recovery times. The measurements were performed on an optimized 750-μm-long AR coated buried heterostructure MQW p-i-n waveguide with a bandedge at 1.48 μm. Figure 1 shows the experimental arrangement. The mode-locked color center laser was tuned to 50 meV beyond the bandedge and 8 ps pulses with peak incident power up to 57 W were coupled into the waveguide. Some residual bandtail absorption remains at this wavelength and this is sufficient to cause carriers to be photogenerated and these give rise to a refractive nonlinearity, predominantly by plasma and bandfilling effects. A Fabry-Perot interferometer is used to measure the spectrum of the light which exits the waveguide. The nonlinearity within the guide causes self phase modulation (SPM) of the light and a study of the spectrum allows information to be recovered on the magnitude and recovery time of the nonlinear phase shift with a reasonable degree of accuracy. SPM spectra were recorded for a variety of pulse energies coupled into he unbiased waveguide. Figure 2 shows the resultant phase shift measured from the SPM spectra as a function of pulse energy. The relationship is a linear one, indicating that no saturation of the nonlinearity occurs for coupled pulse energies up to 230 pJ. A π phase shift, the minimum necessary for an all-optical switch, is obtained for a coupled pulse energy of 57 pJ while the maximum phase shift, 4 π, was measured for 230 pJ. The SPM spectra were highly asymmetric with pulse energy shifted to higher frequencies. Such spectra are characteristic of a slow, negative nonlinearity. This relatively slow speed is expected for the unbiased guide as the recovery time will be of the order of the recombination time of the photogenerated electrons, about 1 ns for InGaAsP material. In order to reduce the recovery time of the nonlinearity, it is necessary to remove the photogenerated carriers from the waveguide by a process other than recombination. One such technique is to apply a reverse bias to the waveguide in order to sweep the carriers out. Figure 3 shows the effect on the recovery time of the nonlinearity of applying reverse bias to the waveguide for 230 pJ coupled power. The recovery time was reduced from one much longer than the length of the pulse, estimated to be about 1 ns, at zero bias to 18 ± 3 ps for a bias voltage greater than -4 V. This compares with a value of 24 ps obtained in a bulk waveguide.

无指盘臭蛙臭蛙肽及其基因和在制药中的应用

本发明涉及一种无指盘臭蛙臭蛙肽及其基因和在制药中的应用，属于生物医学领域。无指盘臭蛙臭蛙肽是无指盘臭蛙臭蛙肽基因编码的一种单链多肽，分子量1814.11道尔顿，等电点8.08，多肽全序列一级结构为： Gly Cys Ser Arg Trp Ile Ile Gly Ile His Gly Gln Ile Cys Arg Asp。(GCSRWIIGIHGQICRD)。编码无指盘臭蛙臭蛙肽的基因由312个核苷酸组成，其中编码成熟无指盘臭蛙臭蛙肽为第141-189位核苷酸。人工合成的无指盘臭蛙臭蛙肽具有很强的抑制细菌和真菌生长的作用，可以作为制备病原微生物感染疾病的治疗药物被应用。本发明的无指盘臭蛙臭蛙肽具有结构简单、人工合成方便、抗菌谱系广、抗菌活性强的特点。

A Plant Needs Ants like a Dog Needs Fleas: Myrmelachista schumanni Ants Gall Many Tree Species to Create Housing

Hundreds of tropical plant species house ant colonies in specialized chambers called domatia. When, in 1873, Richard Spruce likened plant-ants to fleas and asserted that domatia are ant-created galls, he incited a debate that lasted almost a century. Alth

Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine receptor D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention

An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.

Human immunodeficiency virus-1 genotypic drug resistance among volunteer blood donors in Yunnan, China

BACKGROUND: Drug resistance profiles of human immunodeficiency virus-1 (HIV-1) in treatment-naive infections have been reported in developed countries. However, little is known in developing countries, including China, especially in treatment-naive volunt