关键词： BOOKS   REVIEWS  

摘要： Reviews the book “Savanna Animals: Fun Facts and Stuff to Do,” by .

关键词： 呼吸道合胞病毒   树鼩   动物模型  

摘要： 探讨用灵长类动物树鼩建立呼吸道合胞病毒（RSV）感染动物模型的可行性。28只树鼩随机分为7组，每组4只，鼻内滴入10^6PFU RSV，感染后每24h检测1组：另取7只树购鼻内滴入100μl Hep-2细胞培养液，滴鼻后每24h检测1只作对照：无菌取树鼩肺组织进行病毒分离、空斑形成实验检测病毒滴度、病理检查和RT-PCR检测肺组织内RSV mRNA表达：结果显示：树鼩感染RSV后，无明显呼吸道感染症状；树鼩肺组织匀浆接种于Hep-2细胞上，第3、4、5实验组出现细胞病变效应（CPE）；树鼩感染RSV后肺部病理改变在3～7d较为明显，主要为间质改变；在10^6 PFU感染浓度下树鼩肺组织内RSV处于低水平复制，复制的高峰期在3～5d，峰值在第4d。提示：树鼩可以用来建立RSV感染的动物模型。

关键词： Anura   Environment   Trematode Infections  

摘要： The emergence or increased prevalence of various parasites may be linked to alterations in host-parasite interactions caused by environmental changes. We investigated prevalence of trematode infections in grey tree frog (Hyla versicolor) tadpoles from ponds in nonagricultural settings versus ponds adjacent to cornfields in southern Ontario. We found that agricultural activity was a significant factor in determining the percentage of tadpoles infected by 1 or more trematodes from 1 or more species (combined trematode infection). However, we found no associations between combined trematode infection and forest cover;pond size;road density;and measures of water quality, such as nitrate level and the presence of the herbicide atrazine. Although combined trematode prevalence was associated only with agricultural activity, prevalence of Alaria species showed a positive association with forest cover. This latter result probably reflects the importance of habitat suitability for the canid definitive hosts of this trematode species.

关键词： Africa   indirect effects   large herbivore   Saccostomus mearnsi   small mammal   snake   Psammophis mossambicus  

摘要： Many large mammal species are declining in African savannas, yet we understand relatively little about how these declines influence other species. Previous studies have shown that the removal of large herbivorous mammals from large-scale, replicated experimental plots results in a dramatic increase in the density of small mammals, an increase that has been attributed to the relaxation of competition between rodents and large herbivores for food resources. To assess whether the removal of large herbivores also influenced a predator of small mammals, we measured the abundance of the locally common olive hissing snake, Psamniophis mossainbicus, over a 19-mo period in plots with and without large herbivores. Psammophis mossambicus was significantly more abundant in plots where large herbivores were removed and rodent numbers were high. Based on results from raptor surveys and measurements of vegetative cover, differences in snake density do not appear to be driven by differences in rates of predation on snakes. Instead, snakes appear to be responding numerically to greater abundances of small-mammal prey in areas from which large herbivores have been excluded. This is the first empirical demonstration of the indirect effects of large herbivores on snake abundance and presents an interesting example of how the influence of dominant and keystone species can move through a food web.

关键词： wildlife trees   coarse woody debris   wildlife habitat   silvicultural systems   Interior Cedar-Hemlock Zone   inland rainforest  

摘要： Unmanaged cedar (Thuja plicata)-hemlock (Tsuga heterophylla) forests of the northern Interior Wetbelt of British Columbia support standing and dead trees with a variety of structural features that provide habitat for wildlife. We describe the pre-harvest abundance and characteristics of wildlife trees (standing trees with special characteristics that provide habitat for wildlife) and coarse woody debris (CWD) at three silvicultural systems trials in cedar-dominated stands, and the short-term effects of forest harvesting on the abundance and attributes of CWD. The treatments were clearcut, group retention (70% volume removal), group selection (30% volume removal), and unlogged control. We measured standing trees in 75 0.125-ha plots and CWD along 225 24-m transects, using a functional classification system to characterize habitat attributes of trees and logs. CWD assessments were repeated on the same transects after the harvest. The relationship between tree size and occurrence of habitat features was strong for both standing trees and logs. Each of the four major tree species in the study area was associated with specific habitat features that occurred more often in that species than in any other. Large concealed spaces at the bases of trees, providing den sites and escape cover, were associated with hybrid white spruce (Picea engelmannii x glauca). We suggest that these trees had originated on nurse logs that subsequently rotted away;if that supposition is correct, there may be shortages of these structures in future stands that originate from plantations. Forest harvesting had little effect on the volume of CWD, but did affect the decay class distribution, reduce the proportion of pieces having structural habitat attributes, and reduce piece lengths;these effects were generally proportional to the level of harvest removal. Partial-cut silvicultural systems have the potential to mitigate anticipated deficits in large wildlife trees and logs in managed stands, if co

关键词： 12S   cephalopod   COII   gladius   mtDNA genes   phylogeny   sepion   shell   systematics  

摘要： The sepiids are characterized by their cuttlebone or sepion, an internal shell resulting from secondary mineralization of a chitinous 'gladius'. The various species are identified using a combination of shell criteria and 'soft-part' characters. Using mitochondrial genes, we established phylogenetic relationships of sepiids including the three accepted genera (Sepia, Sepiella, Metasepia) and a species complex of uncertain status (Doratosepion). We showed the Sepia genus to be paraphyletic and found no direct correlation between geographical distribution and systematics. We mapped, on the molecular tree, shell characteristics commonly used as reliable diagnostic criteria for taxonomy. Due to the plasticity of the shell, these characters did not appear phylogenetically informative. In an attempt to define systematic categories related to phylogenetic relationships, new clear synapomorphies need to be established for each genus, necessitating a revision of the genus Sepia. (c) 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 89, 139-150.

关键词： Cistus ladaniferus   jejunum   antispasmodic  

摘要： The effects of the aqueous extract of Cistus ladaniferus leaves and stems were studied on the rodent isolated jejunum. The extract produced a reversible concentration dose-dependent (0.1-3 mg/ml) inhibition of the spontaneous motility of the rabbit jejunum. The inhibitory effects of the extract were not affected by pretreatment with the inhibitors of the alpha and beta adrenergic receptors yohimbine, prazosin or propranolol. The extract also inhibited K-induced contractions in rabbit and rat jejunum at a similar concentration range. This result suggests that the antispasmodic action of the extract is mediated through calcium channel blockade. The results confirm the traditional use of C ladaniferus in treating intestinal ache. (c) 2006 Elsevier B.V. All rights reserved.

关键词： 动画   连环画   作品集   中国   现代  

ISBN: (纸本)7802200539

摘要： 本书由四个独立小故事配以大幅彩图组成的经典动物童话合集。

关键词： chital   deer   large seeds   Phyllanthus emblica   Rajaji National Park   regurgitation  

摘要： Ruminant-mediated seed dispersal, an understudied process in tropical forests, was examined via Phyllanthus emblica-Axis axis interaction. A captive Axis deer regurgitated intact P. emblica seeds after retaining them in the rumen for 7-27 h. At Rajaji National Park, a considerable fraction (22%) of deer-regurgitated P. emblica seeds germinated, although lower than unconsumed seeds (72%). The size and strength of seeds like P. emblica might ensure that ruminants regurgitate them intact instead of defecating them.

关键词： ants   Atta   Brazil   Cerrado vegetation   habitat disturbance   habitat selection   nest foundation   road impacts  

摘要： Roads can facilitate the establishment and spread of both native and exotic species. Nevertheless, the precise mechanisms facilitating this expansion are rarely known. We tested the hypothesis that dirt roads are favorable landing and nest initiation sites for founding-queens of the leaf-cutter ant Atta laevigata. For 2 yr, we compared the number of attempts to found new nests (colonization attempts) in dirt roads and the adjacent vegetation in a reserve of cerrado (tree-dominated savanna) in southeastern Brazil. The number of colonization attempts in roads was 5 to 10 times greater than in the adjacent vegetation. Experimental transplants indicate that founding-queens are more likely to establish a nest on bare soil than on soil covered with leaf-litter, but the amount of litter covering the ground did not fully explain the preference of queens for dirt roads. Queens that landed on roads were at higher risk of predation by beetles and ants than those that landed in the adjacent vegetation. Nevertheless, greater predation in roads was not sufficient to offset the greater number of colonization attempts in this habitat. As a consequence, significantly more new colonies were established in roads than in the adjacent vegetation. Our results suggest that disturbance caused by the opening of roads could result in an increased Atta abundance in protected areas of the Brazilian Cerrado.