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General Observations (general + observation)
Selected AbstractsAn investigation of genetic algorithms for the optimization of multi-objective fisheries bioeconomic modelsINTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 1 2000S.J. Mardle Abstract The use of genetic algorithms (GA) for optimization problems offers an alternative approach to the traditional solution methods. GA follow the concept of solution evolution, by stochastically developing generations of solution populations using a given fitness statistic, for example the achievement function in goal programs. They are particularly applicable to problems which are large, non-linear and possibly discrete in nature, features that traditionally add to the degree of complexity of solution. Owing to the probabilistic development of populations, GA do not distinguish solutions, e.g. local optima from other solutions, and therefore cannot guarantee optimality even though a global optimum may be reached. In this paper, a non-linear goal program of the North Sea demersal fisheries is used to develop a genetic algorithm for optimization. Comparisons between the GA approach and traditional solution methods are made, in order to measure the relative effectiveness. General observations of the use of GA in multi-objective fisheries bioeconomic models, and other similar models, are discussed. [source] Geographic Variation in Male Sexual Signals in Strawberry Poison Frogs (Dendrobates pumilio)ETHOLOGY, Issue 9 2007Heike Pröhl In this paper, we compare the advertisement calls of 207 neotropical strawberry poison frogs (Dendrobates pumilio) collected in 21 localities along a transect from northern Costa Rica to western Panama. Populations varied most in call duration and call rate, while pulse rate and duty cycle were less variable. Multivariate analyses showed that call variation followed a cline with higher call rates, shorter calls, lower duty cycles and higher pulse rates in the southeast. Body size decreased towards the southeast and explained most variation in dominant frequency, as well as some residual variation in call rate. We conclude that a combination of geography and morphology is largely responsible for call variation within this species. Two inferred bio-acoustic groups were roughly in accordance with two genetic groups, geographically separated in central Costa Rica. However, genetic distances among populations did not co-vary with call dissimilarity after correction for geographic distances. Thus, differences in calls between genetic groups are probably mainly a result of clinal variation. These findings agree with the general observation that bio-acoustic variation is often not (highly) associated with genetic divergence. Moreover, colour polymorphism observed among Panamanian populations was not reflected in a higher variability in call parameters relative to the monomorphic Costa Rican populations. [source] GEOGRAPHIC VARIATION OF GENETIC AND BEHAVIORAL TRAITS IN NORTHERN AND SOUTHERN TÚNGARA FROGSEVOLUTION, Issue 8 2006Heike Pröhl Abstract We use a combination of microsatellite marker analysis and mate-choice behavior experiments to assess patterns of reproductive isolation of the túngara frog Physalaemus pustulosus along a 550-km transect of 25 populations in Costa Rica and Panama. Earlier studies using allozymes and mitochondrial DNA defined two genetic groups of túngara frogs, one ranging from Mexico to northern Costa Rica (northern group), the second ranging from Panama to northern South America (southern group). Our more fine-scale survey also shows that the northern and southern túngara frogs are genetically different and geographically separated by a gap in the distribution in central Pacific Costa Rica. Genetic differences among populations are highly correlated with geographic distances. Temporal call parameters differed among populations as well as between genetic groups. Differences in calls were explained better by geographic distance than by genetic distance. Phonotaxis experiments showed that females preferred calls of males from their own populations over calls of males from other populations in about two-thirds to three-fourths of the contrasts tested. In mating experiments, females and males from the same group and females from the north with males from the south produced nests and tadpoles. In contrast, females from the south did not produce nests or tadpoles with males from the north. Thus, northern and southern túngara frogs have diverged both genetically and bioacoustically. There is evidence for some prezygotic isolation due to differences in mate recognition and fertilization success, but such isolation is hardly complete. Our results support the general observation that significant differences in sexual signals are often not correlated with strong genetic differentiation. [source] Australian wines in the British wine market: A hedonic price analysisAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 3 2004Bodo E. Steiner The market share of New World wines sold in many European countries has increased dramatically over the past decade. More aggressive marketing, together with a more distinct and recognizable labeling scheme, are often regarded as the keys to the marketing success of these new wines. This article employs hedonic price analysis to identify the values that marketers and consumers place on the information carried by the label of Australian wines in the British wine retail market. Although many grape varieties are given a highly distinct valuation by market participants, our results also suggest that consumers consider regions jointly with grape varieties as proxies for brands. This contrasts with the general observation that grape varietal labeling is the distinctive feature of New World wines. Marketing implications are examined by considering the revenue impact of changes in labeling at the retail level. [JEL citations: L150, D12, C21.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 287,307, 2004. [source] Skin Responses to Ultraviolet Radiation: Effects of Constitutive Pigmentation, Sex, and AncestryPIGMENT CELL & MELANOMA RESEARCH, Issue 5 2002Jennifer K. Wagner Constitutive skin pigmentation and skin responses to ultraviolet radiation were measured on a sample of volunteers (n=250) living in State College, PA, USA. The sample was composed of individuals of European American (n=190), Hispanic (n=45), and East Asian ancestry (n=15). Constitutive pigmentation was measured using the Adjusted Melanin Index (AMI), Erythemal Dose Response (EDR) was measured using the slope of a* at 24 h (,a*), and Melanogenic Dose,Response (MDR) was measured using ,AM, the slope of AMI at 7 d. The relationships between constitutive skin pigmentation, EDR, MDR, sex, age, and ancestry were investigated. European Americans showed a lower constitutive pigmentation, had a significantly higher burn response (EDR), and had a significantly lower tanning response (MDR) than Hispanics and East Asians. No significant difference is seen between Hispanics and East Asians for either constitutive pigmentation or EDR. Constitutive pigmentation in females was slightly lower than in males in all three samples, but the difference was not significant. While no differences were observed in MDR between sexes, males had a stronger EDR than females regardless of population or constitutive pigmentation level, and this difference was significant in European Americans and Hispanics. We observed no age-related differences in any of the populations or measures investigated. We evaluated the relationship between constitutive pigmentation, EDR and MDR. There was a strong inverse correlation between constitutive pigmentation and EDR in the three samples (European Americans, R2=0.176, P < 0.001; Hispanics, R2=0.204, P=0.009; East Asians, R2=0.223, P=0.098) and a strong direct correlation between constitutive pigmentation and MDR in European Americans and Hispanics (European Americans, R2=0.094, P < 0.001; Hispanics, R2=0.164, P=0.012). In other words, persons with lower constitutive pigmentation both burn more and tan less than persons with higher pigmentation. However, after controlling for constitutive pigmentation, EDR and MDR were significantly correlated in European Americans (R2=0.041 P=0.006). Thus, the general observation that persons who burn more tan less is probable because of the common link that these two phenotypes have with constitutive skin pigmentation and, in fact, once pigmentation has been adjusted for, there is a positive correlation between tanning response and burning response in European Americans. [source] THE IMPACT OF REGULATORY COMPETITION ON THE INVESTMENT OF AUSTRALIAN UNIVERSITIES IN NEW ZEALANDECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 2 2005Malcolm Abbott In this paper the regulatory differences between Australia and New Zealand in higher education are examined to determine if they have encouraged the entry of Australian universities into the New Zealand education market. Some general observations are also made about the nature of regulatory competition and the manner in which it influences the development of the international education export industry. [source] Early pyrotechnology in the Near East: Experimental lime-plaster production at the Pre-Pottery Neolithic B site of Kfar HaHoresh, IsraelGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2008Y. Goren A characteristic hallmark of the Pre-Pottery Neolithic B (PPNB) in the southern Levant was the extensive use of lime plaster for architectural and other purposes. Yet no obvious kilns have been identified in archaeological contexts. Here we present details of an experimental pit-kiln modeling lime-plaster production based on observed burnt stone accumulations in pits at the PPNB site of Kfar HaHoresh in the lower Galilee. The experimental kiln was loaded in layers with ,500 kg of limestone (pebbles and stones) and ,1000 kg of fuel (branches and dung). Fired for 24 hours, and reaching a maximum 870°C, the kiln yielded almost 250 kg of quicklime (calcium oxide, CaO). Micromorphological samples, general observations, and scaled plan view drawings made immediately following and nine years after ignition demonstrate that the original shape of the kiln and residual quicklime within and around it rapidly dissipated through bioturbation, trampling by animals, erosion, rain, and exposure to the elements. This could account for the seeming absence of kilns within sites, although they were probably located close to where lime-plaster was applied, given the unstable nature and toxic effects of handling quicklime. Calculations of the manpower and fuel involved indicate that PPNB lime-plaster production may have been less labor intensive and less detrimental to the environment than previously portrayed. © 2008 Wiley Periodicals, Inc. [source] The fatty acid compositions of predator Piocoris luridus (Heteroptera: Lygaeidae) and its host Monosteria unicostata (Heteroptera: Tingidae) reared on almondINSECT SCIENCE, Issue 6 2007OZLEM CAKMAK Abstract The changes in fatty acid compositions during nutritional interaction among almond Amygdalus communis Linnaeus (Rosales: Rosaceae) (host plant), lacebug Monosteria unicostata (Mulsant and Rey) (Heteroptera: Tingidae) and its predator Piocoris luridus Fieber (Heteroptera: Lygaeidae) were determined by gas chromatography and gas chromatography-mass spectrometry analyses. The fatty acid profiles of phospholipids and triacylglycerols were substantially different. Unlike the general observations for virtually most terrestrial insects, arachidonic and eicosapentaenoic acids were detected in high proportions of phospholipid fractions in both insects, especially in P. luridus. Also the almond tissues provide very little oleic acid to the herbivore diet, yet both insect species developed high proportions of this component. Our data reveals instances of specific accumulation of fatty acid biosynthesis, elongation/desaturation, and not incorporating selected fatty acids into cellular lipids. [source] The International Covenant on Economic, Social and Cultural Rights as a tool for combating discrimination against women: general observations and a case study on Algeria*INTERNATIONAL SOCIAL SCIENCE JOURNAL, Issue 184 2005Karima Bennoune The International Covenant on Economic, Social and Cultural Rights (ICESCR) is vital to protecting the human rights of women. This is reflected in the substantive rights which the treaty guarantees and its procedural emphasis on non-discrimination. The ICESCR now has 151 State Parties, as compared with 180 states that have ratified the Convention on the Elimination of All Forms of Discrimination against Women (CEDAW). While the latter is a lightning rod for opposition to the advancement of women's rights, the former is not. It may, therefore, be a particularly useful tool for combating discrimination against women, especially in the Muslim world where resistance to CEDAW in conservative quarters is strong. Still, some argue that the Committee on Economic, Social and Cultural Rights, which monitors implementation of the ICESCR, needs to further elaborate its jurisprudence on women's issues. Against such a complex backdrop, this study will explore the utility of the ICESCR in combating discrimination against women, looking in particular at the example of Algeria, which became a State Party in 1989. [source] Agroindustrialization of the global agrifood economy: bridging development economics and agribusiness researchAGRICULTURAL ECONOMICS, Issue 3 2000Michael L. Cook Abstract This paper examines the agroindustrialization process from two supposedly disparate views: development economics and agribusiness research. The evolution of conceptual and methodological approaches emanating from these fields is explored and general observations are made concerning farm economic interdependence, institutional and organizational change, differing scopes of interest, the causes of agroindustrialization, orientation, and the choice of microanalytic tools, terminology, and unit of analysis. Despite an impressive list of hurdles, disincentives, and disconnects, complementarities between the two fields are identified. The paper concludes by exploring the potential of bridging development economics and agribusiness research to inform the future agroindustrialization research agenda. [source] The development and regulation of lobbying in the new member states of the European UnionJOURNAL OF PUBLIC AFFAIRS, Issue 1-2 2008Conor McGrath This paper focuses on lobbying as a political activity and the emergence of lobbying regulation in 10 new member states of the European Union (EU). The analysis begins with general observations about lobbying in post-communist states and on the development of lobbying in three of the larger new member states: Hungary, Poland and the Czech Republic. Key to how lobbying will continue to develop in the future in these 10 countries is how it will be regulated and controlled. Therefore, the paper examines this in some detail. The analysis concludes with some recommendations on the role that could be played by professional bodies, which represent lobbyists in gaining more acceptance for interest groups in these new member states. Copyright © 2008 John Wiley & Sons, Ltd. [source] Functional analysis of the gibbon foot during terrestrial bipedal walking: Plantar pressure distributions and three-dimensional ground reaction forcesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2005Evie Vereecke Abstract This paper gives a detailed analysis of bipedal walking in the white-handed gibbon, based on collected pressure and force data. These data were obtained from four gibbons in the Wild Animal Park, Planckendael, Belgium, by using a walkway with integrated force plate and pressure mat. This is the first study that collects and describes dynamic plantar pressure data of bipedally walking gibbons, and combines these with force plate data. The combination of these data with previously described roll-off patterns of gibbons, based on general observations, video images, force plates, and EMG data, gives us a detailed description of foot function during gibbon bipedalism. In addition, we compare the observed characteristics of hylobatid bipedalism with the main characteristics of bonobo and human bipedalism. We found that gibbons are midfoot/heel plantigrade, and lack the typical heel-strike of other hominoids. The hallux is widely abducted and touches down at the onset of the stance phase, which results in an L-shaped course of the center of pressure. The vertical force curve is trapezoid to triangular in shape, with high peak values compared to humans. The braking component is shorter than the accelerating component, and shortens further at higher walking velocities. Speed has a significant influence on the forefoot peak pressures and on most of the defined gait parameters (e.g., vertical force peak), and it alters the foot contact pattern as well. The investigation of existing form-function relationships in nonhuman primates is essential for the interpretation of fossil remains, and might help us understand the evolution of habitual bipedal walking in hominids. Am J Phys Anthropol, 2005. © 2005 Wiley-Liss, Inc. [source] The Economics of Organization Structure Changes: a US perspective on demutualizationANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 4 2004Fabio R. Chaddad We document waves of demutualization and review the empirical literature examining the economics of organizational structure changes that have occurred in the US savings and loan and insurance industries since the 1980s. Based on the review of the literature on the economics of conversions, we generate a set of general observations that might inform private and public policy perspectives on the future role of user owned and controlled organizations in market economies. In doing so, the paper may serve as a platform for further discussion among scholars, policymakers, practitioners, and cooperative leaders in their quest to understand and affect the ongoing process of demutualization. [source] An analysis of capital expenses and performance trade-offs among IMS CSCF deployment optionsBELL LABS TECHNICAL JOURNAL, Issue 4 2008Anne Lee Service providers around the world are deploying or planning to deploy the IP Multimedia Subsystem (IMS) in their core networks. IMS allows the delivery of new multimedia applications that can enhance the user's experience and bring in new revenue for the operators. These operators are now faced with deciding how to best deploy the various IMS functional elements in their networks. In this paper, the authors provide a survey of the various options available to the operators and present an analysis of some of those deployment options. In particular, the paper addresses questions around the advantages and disadvantages of centralizing or distributing control functions such as the call session control function (CSCF) in terms of capital expenditure (CAPEX) costs and latency trade-offs. Without the proper deployment strategy, there can be major differences in the overall cost of the network and therefore it is important to perform such an analysis. Initial recommendations and general observations are given that can assist network planners and operators to more efficiently develop an IMS deployment strategy. Further analysis and study that includes operational expenditure (OPEX) costs should also be factored into the final decision. © 2008 Alcatel-Lucent. [source] | ||||||||||||||||