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关键词： conservation biology   Bayesian analysis   matrix population models   recovery plans   viability   mixtures  

摘要： We provide an introduction to Bayesian methods in conservation biology, illustrating inferences, prediction and decision making issues. After presenting the basic framework with a recovery plan evaluation problem, we illustrate more complex issues related to forecasting trends of structured populations using matrix population models and, finally, describe relevant topics in spatial and logistic regression problems. Computational and other implementation difficulties are also discussed. (C) 2003 Published by Elsevier Science Ltd.

关键词： 植物学   学科:生物学   学科:高等学校   生物学  

ISBN: (纸本)7810920170

摘要： 高等农林院校专业基础课教材:本书为配合高等院校新设专业要求课时压缩的要求而编写，针对植物形态解剖学、植物分类学、植物物理学的基本知识等进行讲述。

关键词： SCANNING ELECTRON-MICROSCOPY   COMPARATIVE VEGETATIVE ANATOMY   PHALARIS-CANARIENSIS L   WHEAT TRITICUM-AESTIVUM   X-RAY-MICROANALYSIS   FREQUENCY OXYGEN PLASMA   HORDEUM-SATIVUM JESS   RBCL SEQUENCE DATA   SECALE-CEREALE L   ITALICA L BEAUV  

摘要： Many plants take up soluble monosilicic acid from the soil. Some of these plants subsequently deposit it as cell inclusions of characteristic structure. This article describes the distribution and diversity of opaline silica bodies in monocotyledons in a phylogenetic framework, together with a review of techniques used for their examination, and the ecology, function and economic applications of these cell inclusions. There are several different morphological forms of silica in monocot tissues, and the number of silica bodies per cell may also vary. The most common type is the "druse-like" spherical body, of which there is normally a single body per cell, more in some cases. Other forms include the conical type and an amorphous, fragmentary type (silica sand). Silica bodies are most commonly found either in the epidermis (e.g., in grasses, commelinas and sedges) or in the sheath cells of vascular bundles (e.g., in palms, bananas and orchids). Silica-bearing cells are most commonly associated either with subepidermal sclerenchyma or bundle-sheath sclerenchyma. Silica bodies are found only in orchids and commelinids, not in other lilioid or basal monocots. In orchids, silica bodies are entirely absent from subfamilies Vanilloideae and Orchidoideae and most Epidendroideae but present in some Cypripedioideae and in the putatively basal orchid subfamily Apostasioideae. Among commelinid monocots, silica bodies are present in all palms, Dasypogonaceae and Zingiberales but present or absent in different taxa of Poales and Commelinales, with at least four separate losses of silica bodies in Poales.

关键词： 植物学   zhi   wu   xue   生物学   实验   高等学校   教材  

ISBN: (纸本)7810920189

摘要： 《植物生物学实验》是为适应现代植物科学的发展以及新编《植物生物学》的课程体系而设计的配套实验教材。全书包括植物生物学常用实验技术及原理、植物体的形态与结构、植物的生长与发育、植物多样性与分类、植物与环境、植物生物学野外实习以及附录等7部分，共设计了30个实验。其目的在于给学生提供植物生物学理论与实践相结合的平台，以便使他们熟悉植物生学以及与之相关的实验技术和研究方法，并牢固掌握植物生物学知识。 《植物生物学实验》是集完整性、系统性和可操作性于一体的实验教材，可满足开设植物生物学实验的各类大专院校的教学需要，同时也可供从事生物学及相关领域的工作者参与。

摘要： Electron micrograph examination of the leaf and stem surfaces of Cleome viscosa L (Family Capparaceae) revealed the presence of secretory glandular trichomes with club-cylinder and cylinder morphologies. In the present study, the leaves and stems of C. viscosa were extracted with hexane and the extract was evaluated for the following biological activities: anti-bacterial, anti-fungal, contact insecticidal and nematicidal. The extract was found to be a potent anti-bacterial agent according to the thin layer chromatography autobiographic assay. Activity-directed isolation studies of the anti-bacterially active compounds led to a 14-member ring cembranoid diterpene being identified as one of the effective agents. Minimum inhibitory concentration (MIC) values (mug/spot) of 5.0 mug/spot and 1.0 mug/spot were found for the diterpene on Bacillus subtilis (Gram-positive) and Pseudomonas fluorescens (Gram-negative), respectively. The diterpene did not inhibit the growth of the fungus Cladosporium cucumerinum. The extract demonstrated a pyrethroid type of contact insecticidal activity on adult Cylas formicarius elegantulus Summer (Coleoptera: Curculionidae). The extract also had high nematicidal activity with a percentage Abbott's value of 72.69 on the plant parasitic nematode Meloidogyne incognita Chitwood;however, the extract lost its potency upon subfractionation.

关键词： helminths   trematodes   parasites   cathepsins   proteases   vaccines   immunology   biochemistry  

摘要： Fasciola hepatica secretes cathepsin L proteases that facilitate the penetration of the parasite through the tissues of its host, and also participate in functions such as feeding and immune evasion. The major proteases, cathepsin L1 (FheCL1) and cathepsin L2 (FheCL2) are members of a lineage that gave rise to the human cathepsin Ls, Ks and Ss, but while they exhibit similarities in their substrate specificities to these enzymes they differ in having a wider pH range for activity and an enhanced stability at neutral pH. There are presently 13 Fasciola cathepsin L cDNAs deposited in the public databases representing a gene family of at least seven distinct members, although the temporal and spatial expression of each of these members in the developmental stage of F. hepatica remains unclear. Immunolocalisation and in situ hybridisation studies, using antibody and DNA probes, respectively, show that the vast majority of cathepsin L gene expression is carried out in the epithelial cells lining the parasite gut. Within these cells the enzyme is packaged into secretory vesicles that release their contents into the gut lumen for the purpose of degrading ingested host tissue and blood. Liver flukes also express a novel multi-domain cystatin that may be involved in the regulation of cathepsin L activity. Vaccine trials in both sheep and cattle with purified native FheCL1 and FheCL2 have shown that these enzymes can induce protection, ranging from 33 to 79%, to experimental challenge with metacercariae of F. hepatica, and very potent anti-embryonation/hatch rate effects that would block parasite transmission. In this article we review the vaccine trials carried out over the past 8 years, the role of antibody and T cell responses in mediating protection and discuss the prospects of the cathepsin Ls in the development of first generation recombinant liver fluke vaccines. (C) 2003 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

关键词： Non-programmatic  

摘要： Discusses the effect of flooding on roots' ability to absorb water. Molecular basis for the paradox; Key role of aquaporins in water uptake by roots; Factors gating aquaporins; Effect of decreased cytosolic pH on root permeability.

关键词： Animals   Arthropods/physiology   Bacteria/growth & development   Carbon/metabolism   Coniferophyta   Coniferophyta   Ecosystem   Ecosystem   Environment   Fungi/growth & development   Geography   Invertebrates/physiology   Lauraceae   Lauraceae   Liliaceae/growth & development   Liliaceae/growth & development   Nematoda/physiology   New Zealand   New Zealand   Nitrogen/metabolism   Oligochaeta/physiology   Phosphorus/metabolism   Population Density   Soil   Species Specificity   Trees   Vitex   Vitex  

摘要： Although island attributes such as size and accessibility to colonizing organisms can influence community structure, the consequences of these for ecosystem functioning are little understood. A study of the suspended soils of spatially discrete epiphytes or treetop "islands" in the canopies of New Zealand rainforest trees revealed that different components of the decomposer community responded either positively or negatively to island size, as well as to the tree species that the islands occurred in. This in turn led to important differences between islands in the rates of ecosystem processes driven by the decomposer biota. This system serves as a model for better understanding how attributes of both real and habitat islands may affect key ecosystem functions through determining the community structure of organisms that drive these functions.

关键词： Changnienia amoena   Bombus (Diversobombus) trifasciatus   deceptive pollination   stalk elongation  

摘要： Changnienia amoena Chien is a monotypic species and endemic to China, and was listed on the Chinese Red Book in 1992. The species was once abundant but has become rare and endangered in recent years because of the habitat fragmentation and unduly commercial collections. Previous observation showed that this species has very low and even no fruit set, and the pollinators are not observed before this report. The present observation was conducted at the Shennongjia, Hubei Province during the spring of 2002. The results showed that Bombus (Diversobombus) trifasciatus Smith, B. imitator Pittion and one species of Apis visited the flowers of the orchid, but only B. tritasciatus could carry pollinaria on its body and was the legitimate pollinators of C amoena. During 113 h of observation, only nine visitations were recorded. The bumblebees mainly appeared during 12:00-15:00 during the day. Bumblebees stayed in a flower only a few seconds and never more than ten seconds. The flowers would persist in fresh for about three weeks when they were not pollinated, but 3 or 4 d after pollinated, the pollinated flowers underwent a series of color and morphological changes including stalk elongation and ovary swelling. Therefore, stalk elongation can be considered an index of fruits set. Artificial pollination indicated that C amoena is a highly self-compatible and outcrossing species, but dependent on pollinators for fruit set. Based on the field observations, we concluded that pollination system of C amoena is deceptive. The fruit set in nature is not very low (26.98% on average) compared to other deceptive orchids, which may be related to small population sizes. The number of pollinia removal is much higher than that of fruit set, indicating that there are some degrees of pollinia wasting in C amoena.

关键词： 植物   多酚氧化酶   分子生物学   PPO   分子结构   分子量   活性   基因   克隆   蛋白质   序列保守性   内含子   翻译   表达  

摘要： 本文综述了近年来植物多酚氧化酶在分子生物学如分子结构,分子量,基因克隆、结构、特征与表达调控等方面的研究进展以及植物多酚氧化酶的应用前景。