307 resultados para Defending


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Hunhe, Taizihe rivers originating from the east mountain areas of Liaoning Province are the biggest tributaries of the left bank of Liaohe River. From the initial stage of New China to the early 1990s, the frequency of flood damage had decreased, but recently the disasters have upgraded and changed from trunk stream to tributary basins. In July 1995, Dongzhouhe, a tributary of Hunhe River, suffered from a heaviest flood since establishing the document of floods in Hunhe basin. Meanwhile, a peak discharge, almost beyond double defending ability, occurred at Dadongshanpu Station of Beishahe River, a tributary of Taizihe River. Besides the continued heavy rainstorm, no controllable water conservancy projects and ecological damages caused by quickly decreasing forest cover and water and soil loss are the two main causes of flood damage. In addition, the low flood protection standard is also one of causes. According to the above analyses, some strategies of synthetic controlling for flood damages were put forward: 1) Establishing the system of ecological engineering to defend floods and reduce disasters; 2)Setting up storage and detention areas; 3) Establishing flood controlling information system; 4) Improving the accuracy of media short period and short period rainstorm forecast and flood forecast; 5) Insurance of flood protection.

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我国地域辽阔 ,各种自然灾害的频繁发生 ,人为活动诱发的灾害日趋严重。由于乱砍滥伐 ,使森林资源锐减 ,严重破坏了生态环境 ,特别引起注意的是我国在 50~ 60年代已得到控制的蝗灾 ,近年因干旱已有所复活 ,除此以外 ,各种自然灾害和人为活动诱发的各类灾害 ,造成每年数千人至数万人的死亡 ,直接经济损失约 1 0 0 0~ 2 50 0亿元 ,对国民经济持续、稳定、协调发展造成严重威胁。本文根据上述情况分析了中国灾害的特点 ,列举了近年数起灾害实例 ,以引起人们对生态环境的重视。严峻的现实提醒大家 ,减灾工作已是 2 1世纪的当务之急 !

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Understanding the effect on host plants of defending against herbivores is important in grazing ecology and grassland management. In this study, the morphological and reproductive responses of Caragana microphylla Lam. to grazing sheep were investigated using a 15-year grazing experiment with six stocking rates in the Inner Mongolia steppe of China. Plant height, rachis length, leaflet size, and number of pods decreased significantly, whereas spine density and length increased significantly with increased stocking rate. Significant negative correlations were observed between production of vegetative and reproductive organs and defensive organs, indicating that it is costly for C. microphylla to defend against herbivores and that morphological miniaturization and a tradeoff between production and defense were main responses of C. microphylla to herbivores. (c) 2006 Elsevier Ltd. All rights reserved.

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Karst collapse is one of the most important engineering geology hazards in Karst district, which seriously endangers the living of humankind and the environment around us, as well as the natural resources. Generally speaking, there exist three processes of overburden karst collapse:the formation of soil cavity, the expansion of soil cavity and the fall of the cavity roof. During these processes, groundwater is always the most active factor and plays a key role. Pumping will bring into the great change of groundwater in flow state, flowrate, frequency of fluctuation as well as hydraulic gradient and will speed the fall. Statistics shows that most of the man-made karst collapse are induced by pumping, so studying the mechanism of Karst collapse induced by pumping will provide theoretical base for the prediction and precaution of collapse. By theoretically studying the initial condition for the forming and expanding of a soil cavity, Spalling step by step the essential mechanism of Karst collapse induced by pumping is put forward. The catastrophe model for the collapse induced by pumping is set up to predict the fall probability of a cavity roof, and the criterion for the collapse is determined. Simultaneously, Karst collapse induced by pumping is predicted with manmade neural network theory. Finally, the appropriate precaution measurements for the collapse induced by pumping are provided. The creative opinions of the paper is following: The initial condition of forming a soil cavity is put forwarded as formula (4-1-5), (4-1-24),(4-1-25) and (4-1-27); which provide theoretical base for foreclosing the formation of a soil cavity and defending collapse. Spaliing step by step as the essential mechanism of Karst collapse induced by pumping is put forward. The spaliing force is defined as formula (4-2-15). The condition for the expanding of a soil cavity is that spaliing force is greater than tensile strength of soil. The stability of a soil cavity is first studied with catastrophe theory. It is concluded that the process of development up to ground collapse of a small cavity is continuous, however, the process of a big cavity is catastrophic. It is feasibility that the Karst collapse be predicted with manmade neural network theory as a new way.

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The aim of the present article is to analyse the Apology in its aspect of time. When defending himself against the charges, Socrates appeals to the past, the present and the future. Furthermore, the philosopher stresses the meaning of the duration of time. Thus, the seems to suggest that all really important activities demand a long time to benefit, since they are almost invariably connected with greater efforts. While the dialogue proves thereby to be an ethical one, the various time expressions also gain an ethical dimension.

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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A key component of parental care involves defending resources destined for offspring from a diverse array of potential interspecific competitors, such as social parasites, fungi and bacteria. 2. Just as with other aspects of parental care, such as offspring provisioning or brood defence, sexual conflict between parents may arise over how to share the costs of this form of care. There has been little previous work, however, to investigate how this particular burden might be shared. 3. Here, we describe a hitherto uncharacterized form of parental care in burying beetles Nicrophorus vespilloides, a species which prepares carrion for its young and faces competition from microbes for this resource. We found that parents defend the carcass with antibacterial anal exudates, and that the antibacterial activity of these exudates is only upregulated following the discovery of a corpse. At the same time, phenoloxidase activity in the anal exudates is downregulated, indicating parallels with the internal insect immune system. 4. In unmanipulated breeding pairs, females had higher antibacterial activity in their anal exudates than males, suggesting sex-specific roles in this aspect of parental care. 5. When we experimentally widowed males, we found that they increased levels of antibacterial activity in their anal exudates. Experimentally widowing females, however, led them to decrease levels of antibacterial activity in their anal exudates. Widowed beetles of each sex thus produced anal exudates of comparable antibacterial activity. We suggest that this flexible division of antibacterial activity may be coordinated by Juvenile Hormone. © 2009 British Ecological Society.

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Contesting animals typically gather information about the resource value and that information affects fight motivation. However, it is possible that particular resource characteristics alter the ability to fight independently of the motivation. Using hermit crabs, we investigate how the resource in terms of shell quality affects both motivation and ability to fight. These crabs fight for shells, but those shells have to be carried and may impose physiological costs that impede fight vigour. We find that the shell has different effects on motivation and ability. Potential attackers in very small shells were highly motivated to attack but, rather than having enhanced ability, unexpectedly quickly fatigued and subsequently were not more successful in the fights than were crabs in larger shells. We also examined whether defending crabs could gather information about the attacker's shell from the vigour of the attack. Defending crabs gave up quickly when a potential gain had been assessed, indicating that such information had been gathered. However, there was no indication that this could be owing to the activity of the attacker and the information is probably gathered via visual assessment of the shell.

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Although coordinated patterns of body movement can be used to communicate action intention, they can also be used to deceive. Often known as deceptive movements, these unpredictable patterns of body movement can give a competitive advantage to an attacker when trying to outwit a defender. In this particular study, we immersed novice and expert rugby players in an interactive virtual rugby environment to understand how the dynamics of deceptive body movement influence a defending player’s decisions about how and when to act. When asked to judge final running direction, expert players who were found to tune into prospective tau-based information specified in the dynamics of ‘honest’ movement signals (Centre of Mass), performed significantly better than novices who tuned into the dynamics of ‘deceptive’ movement signals (upper trunk yaw and out-foot placement) (p<.001). These findings were further corroborated in a second experiment where players were able to move as if to intercept or ‘tackle’ the virtual attacker. An analysis of action responses showed that experts waited significantly longer before initiating movement (p<.001). By waiting longer and picking up more information that would inform about future running direction these experts made significantly fewer errors (p<.05). In this paper we not only present a mathematical model that describes how deception in body-based movement is detected, but we also show how perceptual expertise is manifested in action expertise. We conclude that being able to tune into the ‘honest’ information specifying true running action intention gives a strong competitive advantage.

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Access to potable water is frequently said to be the defining world crisis of the twenty-first century. The argument is usually framed in terms of either direct environmental constraints or various totalistic views of how the political determines outcomes. There is little or no scope for the agency of practical politics. Both physical and human geographers tend to be dismissive of the possibilities of democratic politics ever resolving crises such as those of the geography of water provision, in part because of views of scientific expertise that devalue popular participation in decisions about technical matters such as water quality and distribution. Such dismissal also has much to do with a more generalized denigration of politics. Politics (the art of political deliberation, negotiation, and compromise) needs defending against its critics and many of its practitioners. Showing how politics is at work around the world in managing water problems and identifying the challenges that water problems pose for politics provides a retort to those who can only envisage inevitable destruction or a totalistic political panacea as the outcomes of the crisis of the century.

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We consider the problem of self-healing in peer-to-peer networks that are under repeated attack by an omniscient adversary. We assume that the following process continues for up to n rounds where n is the total number of nodes initially in the network: the adversary deletesan arbitrary node from the network, then the network responds by quickly adding a small number of new edges.

We present a distributed data structure that ensures two key properties. First, the diameter of the network is never more than O(log Delta) times its original diameter, where Delta is the maximum degree of the network initially. We note that for many peer-to-peer systems, Delta is polylogarithmic, so the diameter increase would be a O(loglog n) multiplicative factor. Second, the degree of any node never increases by more than 3 over its original degree. Our data structure is fully distributed, has O(1) latency per round and requires each node to send and receive O(1) messages per round. The data structure requires an initial setup phase that has latency equal to the diameter of the original network, and requires, with high probability, each node v to send O(log n) messages along every edge incident to v. Our approach is orthogonal and complementary to traditional topology-based approaches to defending against attack.

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We consider the problem of self-healing in networks that are reconfigurable in the sense that they can change their topology during an attack. Our goal is to maintain connectivity in these networks, even in the presence of repeated adversarial node deletion, by carefully adding edges after each attack. We present a new algorithm, DASH, that provably ensures that: 1) the network stays connected even if an adversary deletes up to all nodes in the network; and 2) no node ever increases its degree by more than 2 log n, where n is the number of nodes initially in the network. DASH is fully distributed; adds new edges only among neighbors of deleted nodes; and has average latency and bandwidth costs that are at most logarithmic in n. DASH has these properties irrespective of the topology of the initial network, and is thus orthogonal and complementary to traditional topology- based approaches to defending against attack. We also prove lower-bounds showing that DASH is asymptotically optimal in terms of minimizing maximum degree increase over multiple attacks. Finally, we present empirical results on power-law graphs that show that DASH performs well in practice, and that it significantly outperforms naive algorithms in reducing maximum degree increase.

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Conventional wisdom has it that the EU is unable to promote viable social integration, which contrasts with its commitments to improving working and living conditions and to social values and goals such as solidarity, social protection and social inclusion. This
article challenges two diff erent standpoints: on the one hand, competitive neoliberalism demands that the EU focuses on economic integration through legally binding internal market and competition rules even if Member States can only maintain a limited commitment to social inclusion, while authors defending the social models unique to the continent of Europe demand that the EU rescinds some of its established legal principles in order to make breathing space for Member States to maintain market correcting social policies. Both positions convene that there should be no genuine social policy at EU level.
This article uses scenarios of widely discussed rulings by the Court of Justice to illustrate that legally enforceable economic integration would prevent most Member States from achieving sustainable health services, labour relations and free university education on the basis of national closure. Since the EU has limited legislative competences to create EU level institutions to balance inequalities, it derives a Constitution of Social Governance from the EU’s values, proposing that the Court of Justice develops its urisprudence into an instrument for challenging European disunion induced by new EU economic governance

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This paper investigates a flexible fault ride through strategy for power systems in China with high wind power penetration. The strategy comprises of adaptive fault ride through requirements and maximum power restrictions of the wind farms with weak fault ride through capabilities. The slight faults and moderate faults with high probability are the main defending objective of the strategy. The adaptive fault ride through requirement in the strategy consists of two sub fault ride through requirements, a temporary slight voltage ride through requirement corresponding to a slight fault incident, with a moderate voltage ride through requirement corresponding to a moderate fault. The temporary overloading capability of the wind farm is reflected in both requirements to enhance the capability to defend slight faults and to avoid tripping when the crowbar is disconnected after moderate faults are cleared. For those wind farms that cannot meet the adaptive fault ride through requirement, restrictions are put on the maximum power output. Simulation results show that the flexible fault ride through strategy increases the fault ride through capability of the wind farm clusters and reduces the wind power curtailment during faults.

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Parasitism is hypothesized to reduce reproductive success in heavily parasitized males because females
may preferentially mate with less parasitized males (parasite-mediated sexual selection) or parasites may compromise
male competitiveness. In marine systems, this hypothesis is largely unexplored. This paper provides the first confirmed record of a copepod ectoparasite (Caligus buechlerae Hewitt 1964) on the common triplefin (Forsterygion lapillum) and evaluates the hypothesis that males parasitized with C. buechlerae experience lower reproductive success than unparasitized males (as determined
by the presence and area of eggs within male nests). We found that 38 % of males we surveyed were infected with
at least one C. buechlerae, with a median of two individuals per infected male. About 32 % of males were defending
eggs, with 62.5 % of those males infected with at least one parasite. Males of greater total length (TL) were both
more likely to be infected and more likely to be defending eggs. However, when statistically accounting for the effects
of TL, parasite infection had no effect on the probability of defending eggs, or the average surface area of eggs when
present. Positive covariation in fish length, the presence of eggs and parasite infection observed here potentially suggest
that the importance of parasitic infection on reproductive success may depend upon the strength of selection for larger male body size. Our study is one of the few studies to investigate the effects of ectoparasites on reproductive success in reef fish and also provides a quantitative measure of infection for a widespread species within New Zealand.