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1.
Ocean upwelling pipes are used to upwell nutrient-rich deeper waters in order to fertilize the surface ocean. This article addresses whether international legal rules exist governing the deployment of ocean pipes and which states are entitled to exercise jurisdiction over these objects. Taking into account the need to avoid user conflicts and unauthorized deployment of upwelling pipes in marine areas under the jurisdiction of third states, the article advocates the development of nonbinding guidelines that would implement the general terms of the United Nations Convention on the Law of the Sea.  相似文献   

2.
Matrix games, defined by a set of strategies and a corresponding matrix of payoffs, are commonly used to model animal populations because they are both simple and generate meaningful results. It is generally assumed that payoffs are independent of time. However, the timing of contests in real populations may have a marked effect on the value of rewards. We consider matrix games where the payoffs are functions of time. Rules are found which hold in this more general situation, and the complexity of possible behaviour is underlined by demonstrating other conditions which do not hold and an illustrative game.  相似文献   

3.
Earth observing satellites, global positioning and geographic information systems are new tools that currently enable the scientific community to integrate ecological, environmental and medical data to develop predictive models for disease surveillance and modelling. A number of investigators have explored remotely sensed environmental factors that might be associated with waterborne disease ecology and human transmission risk. However, health specialists have not been fully familiarized with the capabilities of space technology, and in some cases it has not proved to be the wonder tool that scientists expected. New satellite capabilities and new sensors now allow exploration of risk factors previously beyond the capabilities of remote sensing and put researchers in a position to analyze the effects of environment on disease outbreaks.  相似文献   

4.
Although natural selection should have favoured individuals capable of adjusting the weight they give to personal and social information according to circumstances, individuals generally differ consistently in their individual weighting of both types of information. Such individual differences are correlated with personality traits, suggesting that personality could directly affect individuals' ability to collect personal or social information. Alternatively, the link between personality and information use could simply emerge as a by-product of the sequential decision-making process in a frequency-dependent context. Indeed, when the gains associated with behavioural options depend on the choices of others, an individual's sequence of arrival could constrain its choice of options leading to the emergence of correlated behaviours. Any factor such as personality that affects decision order could thus be correlated with information use. To test this new explanation, we developed an individual-based model that simulates a group of animals engaged in a game of sequential frequency-dependent decision: a producer-scrounger game. Our results confirm that the sequence of decision, in this case enforced by the order in which animals enter a foraging area, consistently influences their mean tactic use and their individual plasticity, an outcome reminiscent of the correlation reported between personality and social information use.  相似文献   

5.
General principles and organizational forms of epidemiological surveillance of plague in the USSR both in seaports andin natural foci are discussed. On the basis of the analysis of the authors' experience over many years and taking into consideration literary data, the authors recommend a minimum, but in their opinion effective amount of a successful realization of these recommendations, it is expedient to establish a special team (or teams) consisting of 10-12 members.  相似文献   

6.
Theoretical work predicts that individuals should strategically increase their reliance on social learning when individual learning would be costly or risky, or when the payoffs for individually learned behaviors are uncertain. Using a method known to elicit cumulative cultural evolution in the laboratory, we investigated the degree of within-group similarity, and between-group variation, in design choices made by participants under conditions of varying uncertainty about the likely effectiveness of those designs. Participants were required to build a tower from spaghetti and modeling clay, their goal being to build the tower as high as possible. In one condition, towers were measured immediately on completion and, therefore, participants were able to judge the success of their design during building. In the other condition, participants' towers were measured 5 min after completion, following a deliberate attempt to test the tower's stability, making it harder for participants to judge whether an innovative solution was liable to result in a good score on the final measurement. Cultural peculiarity (i.e., the extent to which a design could be identified as belonging to a particular chain) was stronger in the delayed measure condition, indicating that participants were placing greater reliance on social learning. Furthermore, in this condition, there was only very weak evidence of successive improvement in performance over learner generations, whereas in the immediate measure condition there was a clear effect of steadily increasing scores on the goal measurement. Increasing the risk associated with learning for oneself may favor the development of arbitrary traditions.  相似文献   

7.
The incorporation of Taiwan into the legal framework of regional fisheries management organisations (RFMOs) has proven to be challenging. This article reviews RFMO practice in this area in light of the recent experience of the Southern Indian Ocean Fisheries Agreement (SIOFA) and outlines some of the legal creativity that has provided solutions. Taiwan's participation in RFMOs is essential to the achievement of effective management outcomes. Accordingly, this article argues that today, with relevant international legal obligations and numerous suitable precedents, political considerations should not represent an obstacle to providing for fair and appropriate involvement of Taiwan in RFMOs.  相似文献   

8.
9.
Plankton collections from the Indian Ocean contain adults and larvae of three species of Thalassocaris: T. lucida (Dana), T. crinita (Dana) and T. obscura sp.n. The new species was previously confused with T. crinita by Borradaile and with T. lucida by Kemp.
Larvae of Thalassocaris are described for the first time. In each species there are 10–13 zoeal stages. The cephalothorax is very broad and shallow, the maxilla has only one coxal endite, and exopods develop on legs 1–4.
T. crinita is a shallow-water species with a wide distribution in the Indian Ocean and western Pacific. T. lucida and T. obscura are open ocean species. T. lucida is most common in the eastern Indian Ocean (and probably in the western Pacific) and is not recorded from the Arabian Sea. T. obscura is most common in the Arabian Sea and is not recorded from the south-eastern Indian Ocean or from the Pacific.
Larval characters do not support the inclusion of Thalassocaris in the Pandalidae. Recognition of the family Thalassocarididae, comprising the genera Thalassocaris and Chlorosocoides, is advocated.  相似文献   

10.
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12.
On the Planet Earth, oceans and seas today correspond to the largest volume offered to Life. Roughly, 275,000 species have been described from marine environments, only representing some 15% of all the present known living. But marine biomass can be enormous. Life appeared in the ancestral ocean 3 800 million years ago and determining events occurred there: appearance of the nuclear membrane and cell nucleus, "pluricellularity", capture of bacteria transformed into organelles, then sexuality. On the 33 phyla existing today on the Earth, 12 never have left the ocean and are exclusively marine. Such biodiversity, archaism of characters, organisational and behavioural patterns make these marine organisms an excellent reservoir for identifying and extracting very interesting pharmacological and cosmetic molecules (>5 000 today) and/or to represent very pertinent "models" for basic and applied research. Relationships between ocean and public health are physical, chemical, biological and physiological. A few marine species as "models" set the base for major advances in life sciences recognized by several Nobel Prices: from the discovery of phagocytosis to anaphylactic shock, and including nervous influx transmission, memory molecular bases, cyclins discovery, eye organisation, neurotransmitter membrane receptors, bases of the specific immune system... These marine models are very useful to understand the origin and functioning of important living mechanisms in the human and sometimes to deduce applications for efficient treatments. Ocean supplies mankind with renewable living resources, much threatened today. We have to manage and protect these to maintain ecosystems, stocks and biodiversity. Only because of the greenhouse effect and anthropic emissions, temperature is globally increasing: and, what if (tomorrow?) one million species would disappear (before 2050) because of global warming?  相似文献   

13.
14.
Cooperative breeding is paradoxical because some individuals forego independent reproduction and instead help others to reproduce. The ecological constraints model states that such behavior arises because of constraints on independent reproduction. Spatial variation in constraints has been shown to co-vary with the incidence of cooperative breeding in correlational and experimental studies. Here, we examine whether temporally variable ecological constraints can act in a similar way to promote cooperative breeding in the atypical system of long-tailed tits Aegithalos caudatus. In this species, individuals may switch reproductive tactics from breeding to helping within the same breeding season. Using 7 yr of field data, we show that reproductive success declined seasonally because of declines in brood size, nestling weight, and juvenile survival. The survival to breeding age of chicks from nests with helpers was higher than for chicks from nests without helpers, and since helpers usually helped at the nest of a close relative, they accrued inclusive fitness benefits. We used these data to model the expected fitness payoffs of breeding and helping at different times during the season. The model shows that late in the breeding season, the fitness payoff from a kin-directed helping tactic becomes greater than that from independent breeding. The behavioral switch predicted by the model is consistent with the observed switch from breeding to helping, which shows that cooperative breeding may evolve as a way of making the best of a bad job at the end of a temporally constrained breeding season.  相似文献   

15.
P. Gopala  Menon 《Journal of Zoology》1972,167(3):371-397
The larval species Atlantocaris gigas Ortmann is shown to be conspecific with Heterocarpus ensifer A. Milne Edwards, while Procletes biangulatus Bate is the larva of Heterocarpus levicarina (Bate). Each species passes through 13–15 zoeal stages and 3–4 megalopal stages. The later zoeal stages are large, have a long toothed rostrum, a carinated carapace and dorsal abdominal spines. The carinae on the carapace are retained in the adult; the rostrum becomes shortened and the abdominal spines modified at metamorphosis. Larval characters support the retention of Heterocarpus in the Pandalidae.
New information on the distribution of both species is included.  相似文献   

16.
17.
In the standard approach to evolutionary games and replicator dynamics, differences in fitness can be interpreted as an excess from the mean Malthusian growth rate in the population. In the underlying reasoning, related to an analysis of “costs” and “benefits”, there is a silent assumption that fitness can be described in some type of units. However, in most cases these units of measure are not explicitly specified. Then the question arises: are these theories testable? How can we measure “benefit” or “cost”? A natural language, useful for describing and justifying comparisons of strategic “cost” versus “benefits”, is the terminology of demography, because the basic events that shape the outcome of natural selection are births and deaths. In this paper, we present the consequences of an explicit analysis of births and deaths in an evolutionary game theoretic framework. We will investigate different types of mortality pressures, their combinations and the possibility of trade-offs between mortality and fertility. We will show that within this new approach it is possible to model how strictly ecological factors such as density dependence and additive background fitness, which seem neutral in classical theory, can affect the outcomes of the game. We consider the example of the Hawk–Dove game, and show that when reformulated in terms of our new approach new details and new biological predictions are produced.  相似文献   

18.
Proteomics technologies and challenges   总被引:4,自引:0,他引:4  
Proteomics is the study of proteins and their interactions in a cell. With the completion of the Human Genome Project, the emphasis is shifting to the protein compliment of the human organism. Because proteome reflects more accurately on the dynamic state of a cell, tissue, or organism, much is expected from proteomics to yield better disease markers for diagnosis and therapy monitoring. The advent of proteomics technologies for global detection and quantitation of proteins creates new opportunities and challenges for those seeking to gain greater understanding of diseases. High-throughput proteomics technologies combining with advanced bioinformatics are extensively used to identify molecular signatures of diseases based on protein pathways and signaling cascades. Mass spectrometry plays a vital role in proteomics and has become an indispensable tool for molecular and cellular biology. While the potential is great, many challenges and issues remain to be solved, such as mining low abundant proteins and integration of proteomics with genomics and metabolomics data. Nevertheless, proteomics is the foundation for constructing and extracting useful knowledge to biomedical research. In this review, a snapshot of contemporary issues in proteomics technologies is discussed.  相似文献   

19.
TILLING and associated technologies   总被引:1,自引:0,他引:1  
Wang T  Uauy C  Till B  Liu CM 《植物学报(英文版)》2010,52(11):1027-1030
  相似文献   

20.
RNA can interact with RNA-binding proteins(RBPs), mRNA, or other non-coding RNAs(ncRNAs) to form complex regulatory networks. High-throughput CLIP-seq, degradome-seq, and RNA-RNA interactome sequencing methods represent powerful approaches to identify biologically relevant ncRNA-target and protein-ncRNA interactions. However, assigning ncRNAs to their regulatory target genes or interacting RNA-binding proteins(RBPs) remains technically challenging. Chemical modifications to mRNA also play important roles in regulating gene expression. Investigation of the functional roles of these modifications relies highly on the detection methods used. RNA structure is also critical at nearly every step of the RNA life cycle. In this review, we summarize recent advances and limitations in CLIP technologies and discuss the computational challenges of and bioinformatics tools used for decoding the functions and regulatory networks of ncRNAs. We also summarize methods used to detect RNA modifications and to probe RNA structure.  相似文献   

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