Home About us Contact
|
Home About us Contact | ||
|
|
||
Competitive Situation (competitive + situation)
Selected AbstractsSize-Dependent Mating Success at Various Nutritional States in the Yellow Dung FlyETHOLOGY, Issue 8 2008Wolf U. Blanckenhorn Mating success not only depends on genetic quality, but also equally on environmental factors, most prominently food availability. We investigated the interactive effects of nutritional state and body size on mating success and copula duration in yellow dung fly males (Scathophaga stercoraria; Diptera: Scathophagidae) of three body size selection lines in the laboratory in both non-competitive (single) and competitive (group) situations. Adults require protein and lipids from prey to reproduce, as well as sugars as an energy source for reproductive activity. We expected mating success to decrease with time because of sperm depletion (sugar treatment) and/or energy shortage (water treatment) relative to the control, prey plus sugar treatment. Based on physiological scaling, we also expected large-line males to become depleted either sooner because of their higher energy and sperm demands, or later because of their more efficient energy use. Average mating success indeed declined over a period of 5,7 d (or 5,15 potential copulations per male), but equally for all food treatments and body size classes. Surprisingly, water-fed and small-line males had the highest mating probability in the non-competitive setting, while in the competitive setting large-line males had the highest success. Energy-depleted males showed apparent terminal investment. Small males acquired females more readily but eventually lost them to larger males in the competitive situation. As shown before, copula duration was inversely related to body size and increased with copulation number, independent of food treatment. We conclude that sugar or prey shortage has little effect on mating success in the short term, and does not differentially affect males of different sizes. [source] Advanced and intelligent technologies for reliable operation of power systems and electricity marketsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2008Ryuichi Yokoyama Senior Member Abstract Deregulation of power industries is still progressing in many countries, aiming at reduction of the electricity price, diversity of customer diverse choices, services and promotion of new business and keeping supply reliability. Many countries are testing this notion in anticipation of lower power prices through open competition. In such a competitive situation, it is necessary for suppliers to take on the responsibility of keeping supply reliability at the load end in order to prevent outages, for instance, independent power producers (IPP) placing distributed generations (DGs) close to the load or conventional utilities utilizing advanced and intelligent system operation/control technologies that are costly. Usually, customers pay one price for power that is good enough for ordinary use, therefore not necessarily highly consistent in quality of voltage, current, frequency or reliability. However, if customers desire better quality power, additional fees are added according to the particular characteristics desired, thus customers are supplied with this type of better power that they choose. Under such a worldwide new trend in power systems and markets, this article is edited for the purpose of introducing the most advanced technologies and the newest issues related to reliable and stable operations of power markets and systems in the competitive environment. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Interest Group Strategies: Navigating Between Privileged Access and Strategies of PressurePOLITICAL STUDIES, Issue 4 2005Anne Binderkrantz The literature often contrasts interest groups possessing insider status and outsider groups forced to seek influence through more indirect means. Drawing on data from a survey of all national Danish interest groups, this article demonstrates that most groups have an action repertoire including both direct contacts to bureaucrats and parliamentarians and indirect activities such as media campaigns and mobilizations of members. Different strategies of influence are correlated positively, hence, there is no contradiction between pursuing strategies associated with insider access to decision-making and strategies where pressure is put on decision makers through media contacts and mobilizations. An analysis of four distinct strategies , an administrative, a parliamentary, a media and a mobilization strategy , finds interesting variations in the factors that affect the pursuance of the various strategies of influence. Groups with a privileged position vis-à-vis decision makers have high levels of activities targeting these decision makers, but the lack of a privileged position does not lead groups to pursue indirect strategies. Indirect strategies are most intensively pursued by cause groups and groups who find themselves in a competitive situation with regard to attracting members. [source] The relationship between socio-sexual behavior and salivary cortisol in bonobos: tests of the tension regulation hypothesisAMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2009Gottfried Hohmann Abstract Bonobos are known for their pacifistic behavior and their large repertoire of behaviors that are thought to serve conflict resolution. One is an unusual form of ventro-ventral mounting that facilitates genital contacts (GC). Various hypotheses have been proposed to explain its function. In this study we tested predictions of the tension regulation hypothesis using salivary cortisol as a marker for social stress. The results indicate a temporal relationship between GC and cortisol levels. Compared with baseline data and matched samples of unrestricted food access, rates of GC increased when access to food sources was restricted. Cortisol levels were highest when access to food was constrained. However, because the behavioral and hormonal responses occurred when viewing the stimulus at a distance and preceded the physical presence of the stimulus, we conclude that the anticipation of a competitive situation was sufficient to induce social stress. Contrary to our prediction, targets of aggression did not have higher rates of GC nor did they solicit GC more often than others. Furthermore, higher GC rates did not correlate with a more pronounced decrease in cortisol levels. Not all results obtained in this study supported the predictions concerning the regulatory function of GC on social tension and further research is needed to explore this question. However, the results indicate that the anticipation of competition may be sufficient to induce a costly physiological response, and that high levels of resource competition may have lasting effects on physical stress and stress management. Am. J. Primatol. 71:223,232, 2009. © 2008 Wiley-Liss, Inc. [source] Symbolic politics in environmental regulation: corporate strategic responsesBUSINESS STRATEGY AND THE ENVIRONMENT, Issue 4 2003Dirk Matten Though not entirely new in political science in general, the concept of symbolic politics (SP) currently meets a vivid reception in law and economics. Yet little attention has been paid to SP from a business perspective. Elements of SP are found in nearly all fields of environmental legislation, and the paper will focus on those empirical examples that have a particular effect on markets, the competitive situation of businesses and corporate strategies in general. The consequences of SP for companies are analysed from two different perspectives. First, business will be seen as an addressee of SP. Specific corporate consequences and reactions are discussed. Second, corporations can be regarded as users of SP, as they assume increasingly a role as political actors themselves. This results from certain developments in environmental regulation as well as from the fact that globalization increasingly weakens national governments and their political power, while at the same time corporate actors assume more influence and responsibility. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment. [source] Genetic fuzzy systems to evolve interaction strategies in multiagent systemsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 9 2007Igor Walter This article suggests an evolutionary approach to designing interaction strategies for multiagent systems, focusing on strategies modeled as fuzzy rule-based systems. The aim is to learn models evolving database and rule bases to improve agent performance when playing in a competitive environment. In competitive situations, data for learning and tuning are rare, and rule bases must jointly evolve with the databases. We introduce an evolutionary algorithm whose operators use variable length chromosomes, a hierarchical relationship among individuals through fitness, and a scheme that successively explores and exploits the search space along generations. Evolution of interaction strategies uncovers unknown and unexpected agent behaviors and allows a richer analysis of negotiation mechanisms and their role as a coordination protocol. An application concerning an electricity market illustrates the effectiveness of the approach. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 971,991, 2007. [source] Amino and cyano N atoms in competitive situations: which is the best hydrogen-bond acceptor?ACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2001A crystallographic database investigation The relative hydrogen-bond acceptor abilities of amino and cyano N atoms have been investigated using data retrieved from the Cambridge Structural Database and via ab initio molecular orbital calculations. Surveys of the CSD for hydrogen bonds between HX (X = N, O) donors, N,T,C,N (push,pull nitriles) and N,(Csp3)n,C,N molecular fragments show that the hydrogen bonds are more abundant on the nitrile than on the amino nitrogen. In the push,pull family, in which T is a transmitter of resonance effects, the hydrogen-bonding ability of the cyano nitrogen is increased by conjugative interactions between the lone pair of the amino substituent and the C,N group: a clear example of resonance-assisted hydrogen bonding. The strength of the hydrogen-bonds on the cyano nitrogen in this family follows the experimental order of hydrogen-bond basicity, as observed in solution through the pKHB scale. The number of hydrogen bonds established on the amino nitrogen is greater for aliphatic aminonitriles N,(Csp3)n,C,N, but remains low. This behaviour reflects the greater sensitivity of the amino nitrogen to steric hindrance and the electron-withdrawing inductive effect compared with the cyano nitrogen. Ab initio molecular orbital calculations (B3LYP/6-31+G** level) of electrostatic potentials on the molecular surface around each nitrogen confirm the experimental observations. [source] | |||||||||||||