919 resultados para Animals in poetry.


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We review the progress made in the emerging field of coastal seascape ecology, i.e. the application of landscape ecology concepts and techniques to the coastal marine environment. Since the early 1990s, the landscape ecology approach has been applied in several coastal subtidal and intertidal biogenic habitats across a range of spatial scales. Emerging evidence indicates that animals in these seascapes respond to the structure of patches and patch mosaics in different ways and at different spatial scales, yet we still know very little about the ecological significance of these relationships and the consequences of change in seascape patterning for ecosystem functioning and overall biodiversity. Ecological interactions that occur within patches and among different types of patches (or seascapes) are likely to be critically important in maintaining primary and secondary production, trophic transfer, biodiversity, coastal protection, and supporting a wealth of ecosystem goods and services. We review faunal responses to patch and seascape structure, including effects of fragmentation on 5 focal habitats: seagrass meadows, salt marshes, coral reefs, mangrove forests, and oyster reefs. Extrapolating and generalizing spatial relationships between ecological patterns and processes across scales remains a significant challenge, and we show that there are major gaps in our understanding of these relationships. Filling these gaps will be crucial for managing and responding to an inevitably changing coastal environment. We show that critical ecological thresholds exist in the structural patterning of biogenic ecosystems that, when exceeded, cause abrupt shifts in the distribution and abundance of organisms. A better understanding of faunal–seascape relationships, including the identifications of threshold effects, is urgently needed to support the development of more effective and holistic management actions in restoration, site prioritization, and forecasting the impacts of environmental change.

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世界上最大的大坝—三峡大坝―于2003年6月正式建成并蓄水,三峡水库的水位由蓄水前的84m上升至蓄水后的139m。三峡大坝的修建与蓄水,已经显著地改变了三峡库区陆地生态系统和水域生态系统的生态环境。三峡大坝的修建将如何影响生活在这一区域(包括陆地和水域)的野生动植物资源,是个亟待解决的问题。 对于陆地生态系统,三峡大坝的修建,使三峡库区的生态环境进一步破碎化(Fragmentation)和岛屿化(Island)。为了了解三峡大坝的修建对三峡库区野生动物所产生的影响,我们选择适应性强且对环境变化敏感的啮齿动物为研究对象,在三峡库区选取两个岛屿(洛碛岛和皇华岛)及其对岸为研究点,在野外调查了啮齿动物的群落组成、种群密度与分布,并用胃容物分析和稳定性同位素分析方法研究了两个研究点优势种啮齿动物的食物来源与组成。结果表明,两个研究点间啮齿动物群落组成有很大差异,这主要是由于啮齿动物分布的地域性差异引起的。在同一个研究点,岛屿上的啮齿动物群落组成与对岸的没有差异,但在岛屿上的啮齿动物种群密度却明显高于其对岸的,这说明随着库区水位的大幅度提升,岛屿的面积急剧减小,使原本栖息在水边的啮齿动物不得不向岛屿的中上部迁移,致使岛屿上的啮齿动物的种群密度迅速增加。啮齿动物的食物来源有四种:C3非豆科植物,C3豆科植物,C4植物及水生生物。不同种啮齿动物的食物种类组成也不同,四川短尾鼩(Anourosorex squamipes)的食物中有水生生物的组成成分,但其它啮齿动物食物中不含水生生物。不同食物来源在啮齿动物的整体食物中所占比例也不同,并呈明显的季节性变化,这种变化与田间的农作物种类密切相关。动物组织的稳定性同位素组成不仅可以示踪动物的食物来源,也反映了动物的生存状况。我们的结果显示:对岸啮齿动物的稳定性同位素组成相对集中,并且不同种啮齿动物间没有重叠。这一方面说明对岸啮齿动物的食物来源相对丰富,啮齿动物可以选择各自喜食食物,在此环境下的啮齿动物种间竞争相对较弱,至少是种间食物竞争较弱。岛屿上啮齿动物的稳定性同位素值分布范围远大于在对岸的,并且种间稳定性同位素组成有明显的重叠部分。稳定性同位素组成的重叠意味着有相似的食物来源,也即栖息生境相似。这说明岛上的啮齿动物种间存在较剧烈的食物竞争关系。在资源限制情况下,多种啮齿动物不得不利用共同的食物来源。换句话说,岛屿化过程将加剧岛屿上啮齿动物的种间竞争。 洛碛岛上的四川短尾鼩因为可以利用水生食物来源,这使得它在岛屿化过程中处于有利地位。随着岛屿化进程的加剧,四川短尾鼩在岛屿上的优势将更加明显。而皇华岛屿上的褐家鼠的食物来源单一,会因岛屿面积的进一步减小,食物来源更加缺乏,它们将不得不改其食物组成或面临消失。而白腹巨鼠的栖息环境靠近江边,将因水位的上升进一步上移,它们的栖息环境与普通田鼠的发生重叠,使得白腹巨鼠与普通田鼠发生栖息地的竞争与食物竞争,并面临更多的人为因素干扰。 对于水域生态系统,长江是我国最大的河流,也是我国淡水鱼类最丰富的区域。三峡大坝的修建已经显著改变了三峡库区的水文特征。为了了解三峡大坝的修建是否会改变三峡库区的有机物组成,并进而影响到三峡库区水生生物的食物来源和组成,我们选择了三个水文特征不同的研究点(洛碛江段、皇华城江段和茅坪江段)调查了三峡库区的常见鱼种类组成,并用稳定性同位素方法研究了三峡库区洪水前后的有机物组成变化与鱼类的食物网模型,用稳定性同位素划分了鱼类食物网结构及鱼类体长与其肌肉δ15N值间的关系。结果表明,三峡大坝的修建,已经显著改变了皇华城和茅坪江段的水文特征,同时也“干扰”了生活在这一区域的鱼类。适应于流水环境的鱼类在库区回水处和大坝附近几乎消失,而喜欢静态环境的其它鱼类却得到极大的发展,例如鲢鱼(H. molitrix)和草鱼( C. idellus)。 洪水前后,三峡库区的有机物组成成分有明显改变。洪水前,水中有机物主要以河流自身生产力产生的有机物为主(浮游植物、藻类等);洪水后,水中有机物主要以外来有机物为主(陆地植物、土壤有机物和从上游带来的有机物)。对于三个食物网模型:河流连续体模型(RCC)、脉冲模型(FPC)和河流生产力模型(RPM),河流生产力模型能更好的解释三峡库区的水生生物的食物来源,即三峡库区的水生生物的食物主要来源于河流自身生产力产生的有机物。但外来有机物作为水生生物的一种辅助食物来源,在洪水期间起到不可忽视的作用。 在本研究中,鱼类体长与其δ15N值间的关系与选取鱼的种类有关,比如南方大口鲇(Silurus asotus)的体长与其肌肉的δ15N值呈明显负相关关系(R2≈0.5),而鱖鱼(Siniperca)、铜鱼(Coreius guichenoti)和草鱼(Ctenopharyngodon idellus)的体长与其肌肉的δ15N值却呈正相关关系。 三峡库区常见鱼类主要以杂食性和广普性鱼类为主,食物网结构十分复杂。通过胃容物分析和稳定性同位素分析,三峡库区水生生物营养级间的判别值约为3.1‰。依据鱼类肌肉的δ15N值,三峡库区的常见鱼类可以划分为四个营养级:草食性鱼类(herbivorous fish)、初级杂食性鱼类(1ºomnivorous fish)、次级杂食性鱼类(2ºomnivorous fish)和食鱼性鱼类(piscivorous fish)。营养级间没有明确的分界限,鱼类的营养级从2到4.8,是连续分布的营养级结构,从而更真实的反映了自然界中动物的捕食关系和在食物网中的位置。 自然丰度变化的稳定性同位素(Stable isotope)作为一种天然的示踪物,在动物生态学上已经得到广泛应用。动物的稳定性同位素可以清楚的示踪动物的食物来源、食物组成、栖息地情况和生存状况等多种信息,结合传统的胃容物分析,或其它的粪便分析、储藏物分析等,稳定性同位素技术在动物生态学研究方面必将得到更广泛的应用。

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The present study of Strongylocentrotus lividus is an attempt to add to the knowledge in this field with particular reference to a tropical species of whose biology little is known. The aim of the study was to examine the growth of the animals in relation to the development of their gonads, to elucidate the food preferences of the sea urchins and to study their associations with other animals.

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Several important advances have been made in our knowledge both regarding the factors which determine fertility in tropical lakes and the fish that live in them. As a result of our investigations a new theory has been put forward regarding the part played by animals in the bionomics of a lake; this theory, stated somewhat baldly, is that within certain limits the greater the number of animals in a shallow tropical lake, the greater becomes its potential fertility, and therefore the greater the number of animals it can support. The theory arises as a logical conclusion, once we accept the fact that the rate of production in such a lake is determined by the rate at which organic matter is decomposed. Bottom deposits which consist mainly of vegetable matter decompose slowly, whereas deposits which contain a high proportion of matter of animal origin decompose more rapidly. Thus the more animals in a lake, particularly animals which feed on plant material, the faster the biological cycle can proceed and the greater the density of animals it can support. This new concept will have a very profound influence on our ideas concerning the consequences of overfishing tropical waters. It also shows that efforts must be made to encourage and protect all herbivorous and detritus feeding animals, whether they be copepods, fish, or hippopotami, and whether they are of immediate economic importance or not.

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The primary objective in doing this work was to become acquainted with as many forms as possible of the marine fauna of the intertidal zone and if possible to determine some of the environmental relationships which exist in as many different types of habitats as possible. Due to limited amount of time spent in this study no very intensive work could be done and only a general survey was made of the more conspicuous forms of life which were encountered. Most of the work consisted of collecting and observing animals in the tide pools during periods of low tides. The animals collected were then taken to the laboratory and observed and determined as to species. Notes were taken as to place, time, and situation under which the animals were found. As many different types of habitats as possible were visited which included rocky intertidal areas of Mussel Point, Point Pinos, Lighthouse Point, Pescadero Point and Carmel Point just east of Carmel Beach. Sandy beaches were visited at Monterey Beach, Carmel Beach and Asilomar Beach. A marine estuary habitat was visited at Elkhorn Slough. More than two hundred species were identified and observed during this six-week period. A rather hasty population study was made of the eelgrass, Phyllospadix, of the intertidal zone at Mussel Point and of an algae, Gigartina caniculata, which grows at the level just above the eelgrass.

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Domestic cats and dogs are important companion animals and model animals in biomedical research. The cat has a highly conserved karyotype, closely resembling the ancestral karyotype of mammals, while the dog has one of the most extensively rearranged mammalian karyotypes investigated so far. We have constructed the first detailed comparative chromosome map of the domestic dog and cat by reciprocal chromosome painting. Dog paints specific for the 38 autosomes and the X chromosomes delineated 68 conserved chromosomal segments in the cat, while reverse painting of cat probes onto red fox and dog chromosomes revealed 65 conserved segments. Most conserved segments on cat chromosomes also show a high degree of conservation in G-banding patterns compared with their canine counterparts. At least 47 chromosomal fissions (breaks), 25 fusions and one inversion are needed to convert the cat karyotype to that of the dog, confirming that extensive chromosome rearrangements differentiate the karyotypes of the cat and dog. Comparative analysis of the distribution patterns of conserved segments defined by dog paints on cat and human chromosomes has refined the human/cat comparative genome map and, most importantly, has revealed 15 cryptic inversions in seven large chromosomal regions of conserved synteny between humans and cats.

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The freshwater giant prawn (golda), Macrobrachium rosenbergii and tiger shrimp (bagda), Penaeus monodon were stocked together with or without fin fishes at different stocking rates in semi-saline waters at Khulna region and their growth, survival, yield and costreturn analysis were made. Survival rate of golda and bagda ranged from 23.0 to 36.8% and 8.2 to 24%, respectively. The both species were significantly affected by their own stocking density. The average final weight of golda and bagda ranged from 62.4 to 73.3 g and 32.0 to 66.4 g. The bivariate analysis of average final weight of both golda and bagda revealed that golda positively and bagda negatively influenced by the total stocking density. However, the results of the individual sizes of both golda and bagda showed an increase in the proportions of smaller animals and a decrease in the proportion of larger ones with increasing stocking rates. The harvesting weights of all animals in the experimental ghers were in marketable sizes although their prices varied with the individual size. The total production comprised of both golda and bagda ranged from 514.6 to 952.8 kg ha·1, over a culture period of 10 months. Return on investment ranged from 51.0 to 125.7%.

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The paper presents the usefulness of beta-glucans as immunostimulants for strengthening the non-specific defense system of a wide range of animals. In Taiwan, researchers tested the effects of beta-glucans on the vibriosis resistance of tiger shrimp Penaeus monodon which yield promising results. They suggest that supplementation of beta-glucan at 0.5 mg per ml is sufficient in strengthening the non-specific defense mechanism of postlarval shrimp.

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Ecological study on Kolahy and 'flab estuaries were carried out during 1996-1997. Water and sediment sampling was done seasonally. In order to study the physical and chemical characteristic of the water, various animal fauna from different material niches including planktons and fish from water, benthousi from the sediment , and surface living animal such as Arthropod (Crabs) and Waterbirds were identified. I he result shoved, that water salinity of both estuaries was the same as the general salinity existing its the Persian Gulf water, and its variation is same IN those waters Minimum water salinity in both estuaries are seen during Bahairdan or early winter mooth(Jaa.), which is about 31ppt and Maximum is during .rirldlun.) or summer mouth at about 19 ppt. Dissolved otygen and pH are slime as the general Persian Gulf waters., Dissolve Oxygen being directly associated to temperature and its fluctuation is between 7- Sing/I and pH between 7.5-LS. The animals of both estuaries are almost similar having a sal factory species diversity . The birds of the region are often seasonal migrants , the maximum population of which occurs in winter season and the minimum during summer month. Nam coverage is richer in Tiab than Kolahy estuary, where in Kolahy a signal Mangrove tree is in exigence. 'Ile total coverage of Mangrove forest in Tiab is estimated about -29 hec.Both estuaries are included with in the international Ramsar Convention sites in 1971. Due to national importance of these estuaries inproviding refugee for various birds species and also hinting grounds and access traffic for local fishing vehicles, Actiog as an important access for various inhabitancy living with these area of the Persian Gulf. Due to importance or prawn aquacultur for the economical well being of local inhabitance, these areas provide a suitable grandees for prawn production. I-test statistics show, there are no significant difference among various invertebrate and vertebrate animals. In over all out look 21) phytoplankton genera, 21) zeoplankton genera 17 miafauna and 32 roaerofauna genera , 11 different species Carcineacearions and 119 species of walerbirds were identified with in the Tiab and Kolahy estuariesregioos. The X statistic show that the animal density is directly associated to season. Where density of miofauna and maerofauna in both estuaries are in maiticrourn during summer and the minimums existing during the winter season. In addition the bentic invertebrate population density in closlly association to birds population density since , the later, feeds on the former animals. Where the increasing in bird population density during the winter season, the bentic invertebrate animal population density decreases. The over all trend of animal population density in winter tend to increased towards the summer seasons, which this is due to climatic conditions of the region. The bird population on the contrary to other animals of both estuaries tend to increase from summer towards the winter seasons and which this bird population density is in maximum in winter with in the region.

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The otter belongs to the family Muslelidae of the super family Canoidea. It is a mammal related to the stoat, skunk, marten and wolverine. Its habitat is the water, and it is carnivorous in diet, feeding on fish and other water animals. In Uganda, the otter is widely distributed throughout the western region, and most other parts of the country. To protect fish farmers from the otter, the Fisheries Department recommends fencing the ponds to keep out the otters or trapping to kill them.

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At present, acute vascular rejection (AVR) remains a primary obstacle inhibiting long-term graft survival in the pig-to-non-human primate transplant model. The present study was undertaken to determine whether repetitive injection of low dose Yunnan-cobra venom factor (Y-CVF), a potent complement inhibitor derived from the venom of Naja kaouthia can completely abrogate hemolytic complement activity and subsequently improve the results in a pig-to-rhesus monkey heterotopic heart transplant model. Nine adult rhesus monkeys received a heterotopic heart transplant from wild-type pigs and the recipients were allocated into two groups: group 1 (n = 4) received repetitive injection of low dose Y-CVF until the end of the study and group 2 (n = 5) did not receive Y-CVF. All recipients were treated with cyclosporine A (CsA), cyclophosphamide (CyP) and steroids. Repetitive Y-CVF treatment led to very dramatic fall in CH50 and serum C3 levels (CH50 < 3 units/C3 remained undetectable throughout the experiment) and successfully prevented hyperacute rejection (HAR), while three of five animals in group 2 underwent HAR. However, the continuous suppression of circulating complement did not prevent AVR and the grafts in group 1 survived from 8 to 13 days. Despite undetectable C3 in circulating blood, C3 deposition was present in these grafts. The venular thrombosis was the predominant histopathologic feature of AVR. We conclude that repetitive injection of low dose Y-CVF can be used to continuously suppress circulating complement in a very potent manner and successfully prevent HAR. However, this therapy did not inhibit complement deposition in the graft and failed to prevent AVR. These data suggest that using alternative pig donors [i.e. human decay accelerating factor (hDAF)-transgenic] in combination with the systemic use of complement inhibitors may be necessary to further control complement activation and improve survival in pig-to-non-human primate xenotransplant model.

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Animals, in particular humans, frequently punish other individuals who behave negatively or uncooperatively towards them. In animals, this usually serves to protect the personal interests of the individual concerned, and its kin. However, humans also punish altruistically, in which the act of punishing is personally costly. The propensity to do so has been proposed to reflect the cultural acquisition of norms of behaviour, which incorporates the desire to uphold equity and fairness, and promotes cooperation. Here, we review the proximate neurobiological basis of punishment, considering the motivational processes that underlie punishing actions.

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Cetaceans produce sound signals frequently. Usually, acoustic localization of cetaceans was made by cable hydrophone arrays and multichannel recording systems. In this study, a simple and relatively inexpensive towed acoustic system consisting of two miniature stereo acoustic data-loggers is described for localization and tracking of finless porpoises in a mobile survey. Among 204 porpoises detected acoustically, 34 individuals (similar to 17%) were localized, and 4 of the 34 localized individuals were tracked. The accuracy of the localization is considered to be fairly high, as the upper bounds of relative distance errors were less than 41% within 173 m. With the location information, source levels of finless porpoise clicks were estimated to range from 180 to 209 dB re 1 mu Pa pp at 1 m with an average of 197 dB (N=34), which is over 20 dB higher than that estimated previously from animals in enclosed waters. For the four tracked porpoises, two-dimensional swimming trajectories relative to the moving survey boat, absolute swimming speed, and absolute heading direction are deduced by assuming the animal movements are straight and at constant speed in the segment between two consecutive locations.

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Oxidative stress response after prolonged exposure to a low dose of microcystins (MCs) was studied in liver, kidney and brain of domestic rabbits. Rabbits were treated with extracted MCs (mainly MC-LR and MC-RR) at a dose of 2 MC-LReq. mu g/kg body weight or saline solution every 24 h for 7 or 14 days. During the exposure of MCs, increase of lipid peroxidation (LPO) levels were detected in all the organs studied, while antioxidant enzymes responded differently among different organs. The enzyme activities Of Superoxide dismutase (SOD). catalase (CAT) and glutathione reductase (GR) in liver decreased in the MCs treated animals. In brain, there were obvious changes in glutathione peroxidase (GPx) and GR, while only CAT was obviously influenced in kidney. Therefore, daily exposure at a lower dosage of MCs, which mimicked a natural route of MCs. could also induce obvious oxidative stress in diverse organs of domestic rabbits. The oxidative stress induced by MCs in brain was as serious as in liver and kidney, suggesting that brain may also be a target of MCs in mammals. And it seems that animals may have more time to metabolize the toxins or to form an adaptive response to reduce the adverse effects when exposed to the low dose of MCs. (C) 2008 Elsevier B.V. All rights reserved.

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The metallothionein-2 (MT-2) gene was isolated from the mandarin fish, one of the most important industrial aquatic animals in China, by using rapid amplification of cDNA ends (RACE). The deduced amino acid sequence of MT-2 comprised 60 amino acids and showed approximately 62.3% identity to human metallothionein. Its promoter region was amplified by thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR). The MT-2 gene consists of 3 exons and 2 introns, extending approximately 900 bp of genomic sequence. Phylogenetic analysis clearly demonstrated that MT-2 formed a clade with fish metallothionein. The promoter region contained 5 putative metal-regulatory elements (MREs) and 1 TATA box. Real-time quantitative RT-PCR analysis revealed that MT-2 transcripts were significantly increased in the brain and gills and were stable in the muscles, liver, and trunk kidney in Cd2+-stimulated fish. Western blotting analysis demonstrated that the protein of the MT-2 gene was expressed mainly in the gills, liver, heart, trunk kidney, muscle, and intestine; it was weakly detected in the brain and head kidney. Moreover, the MT-2 protein was immunohistochemically detected in the cytoplasm in the liver and trunk kidney. All the above results revealed that the mandarin fish MT-2 would be a useful biomarker for metal pollution. (C) 2008 Published by Elsevier Inc.