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Origins
Kinds of Origins Selected AbstractsSOCIALITY IN THERIDIID SPIDERS: REPEATED ORIGINS OF AN EVOLUTIONARY DEAD ENDEVOLUTION, Issue 11 2006Ingi Agnarsson Abstract Evolutionary ,dead ends' result from traits that are selectively advantageous in the short term but ultimately result in lowered diversification rates of lineages. In spiders, 23 species scattered across eight families share a social system in which individuals live in colonies and cooperate in nest maintenance, prey capture, and brood care. Most of these species are inbred and have highly female-biased sex ratios. Here we show that in Theridiidae this social system originated eight to nine times independently among 11 to 12 species for a remarkable 18 to 19 origins across spiders. In Theridiidae, the origins cluster significantly in one clade marked by a possible preadaptation: extended maternal care. In most derivations, sociality is limited to isolated species: social species are sister to social species only thrice. To examine whether sociality in spiders represents an evolutionary dead end, we develop a test that compares the observed phylogenetic isolation of social species to the simulated evolution of social and non-social clades under equal diversification rates, and find that sociality in Theridiidae is significantly isolated. Because social clades are not in general smaller than their nonsocial sister clades, the spindly phylogenetic pattern,many tiny replicate social clades,may be explained by extinction rapid enough that a nonsocial sister group does not have time to diversify while the social lineage remains extant. In this case, this repeated origin and extinction of sociality suggests a conflict between the short-term benefits and long-term costs of inbred sociality. Although benefits of group living may initially outweigh costs of inbreeding (hence the replicate origins), in the long run the subdivision of the populations in relatively small and highly inbred colony lineages may result in higher extinction, thus an evolutionary dead end. [source] PERSPECTIVE: MATERNAL KIN GROUPS AND THE ORIGINS OF ASYMMETRIC GENETIC SYSTEMS,GENOMIC IMPRINTING, HAPLODIPLOIDY, AND PARTHENOGENESISEVOLUTION, Issue 4 2006Benjamin B. Normark Abstract The genetic systems of animals and plants are typically eumendelian. That is, an equal complement of autosomes is inherited from each of two parents, and at each locus, each parent's allele is equally likely to be expressed and equally likely to be transmitted. Genetic systems that violate any of these eumendelian symmetries are termed asymmetric and include parent-specific gene expression (PSGE), haplodiploidy, thelytoky, and related systems. Asymmetric genetic systems typically arise in lineages with close associations between kin (gregarious siblings, brooding, or viviparity). To date, different explanatory frameworks have been proposed to account for each of the different asymmetric genetic systems. Haig's kinship theory of genomic imprinting argues that PSGE arises when kinship asymmetries between interacting kin create conflicts between maternally and paternally derived alleles. Greater maternal than paternal relatedness within groups selects for more "abstemious" expression of maternally derived alleles and more "greedy" expression of paternally derived alleles. Here, I argue that this process may also underlie origins of haplodiploidy and many origins of thelytoky. The tendency for paternal alleles to be more "greedy" in maternal kin groups means that maternal-paternal conflict is not a zero-sum game: the maternal optimum will more closely correspond to the optimum for family groups and demes and for associated entities such as symbionts. Often in these circumstances, partial or complete suppression of paternal gene expression will evolve (haplodiploidy, thelytoky), or other features of the life cycle will evolve to minimize the conflict (monogamy, inbreeding). Maternally transmitted cytoplasmic elements and maternally imprinted nuclear alleles have a shared interest in minimizing agonistic interactions between female siblings and may cooperate to exclude the paternal genome. Eusociality is the most dramatic expression of the conflict-reducing effects of haplodiploidy, but its original and more widespread function may be suppression of intrafamilial cannibalism. In rare circumstances in which paternal gene products gain access to maternal physiology via a placenta, PSGE with greedy paternal gene expression can persist (e.g., in mammals). [source] THE ORIGINS OF ROBUSTNESS1EVOLUTION, Issue 2 2006Thomas F. Hansen No abstract is available for this article. [source] UNDERSTANDING THE ORIGINS OF AREAS OF ENDEMISM IN PHYLOGEOGRAPHIC ANALYSES: A REPLY TO BRIDLE ET AL.EVOLUTION, Issue 6 2004Ben J. Evans First page of article [source] THE BROCH CULTURES OF ATLANTIC SCOTLAND: ORIGINS, HIGH NOON AND DECLINE.OXFORD JOURNAL OF ARCHAEOLOGY, Issue 3 2008200 BC, PART 1: EARLY IRON AGE BEGINNINGS c.700 Summary. A new overview of the broch and wheelhouse-building cultures is offered because recent comparable attempts have omitted substantial amounts of relevant data, such as discussion of the most plausible broch prototypes and of the details of the material cultural sequence, particularly the pottery. Well dated Early Iron Age roundhouse sites have often been described, but promontory forts of the same period, showing the specialized broch hollow wall, have not. The example at Clickhimin, Shetland, is now reliably dated to the sixth century BC at the latest and the associated pottery shows clear links with north-west France. Another unexcavated example in Harris can be restored in some detail and shows how these sites were probably used. The pivotal role of Shetland in the emergence of the new culture is confirmed by the early dating of the broch at Old Scatness to the fourth/third centuries BC. However, a separate development of the round broch tower seems also to have occurred in the west, in the third/second centuries BC. English Early Iron Age pottery is also prominent in some of the earliest sites in the west and north. The picture is of a dynamic, maritime zone open to influences from several remote regions. [source] ON THE TRUE ORIGINS OF THE WALTHER'S GANGLION BLOCKADE AND MOREPAIN PRACTICE, Issue 4 2008Dr Ricardo Plancarte No abstract is available for this article. [source] MENTORING: HISTORICAL ORIGINS AND CONTEMPORARY VALUEANZ JOURNAL OF SURGERY, Issue 10 2008FRACS, Ian Gough MD No abstract is available for this article. [source] ,MERELY MECHANICAL': ON THE ORIGINS OF PHOTOGRAPHIC COPYRIGHT IN FRANCE AND GREAT BRITAINART HISTORY, Issue 1 2008ANNE MCCAULEY The invention of the medium of photography and its commercialization as a cheap multiple during the 1850s and 1860s led to challenges to extant copyright laws in France and Great Britain. This paper traces the ways that debates over photographic copyright confronted current understandings of originality and mechanization and repeated arguments that had already been raised by laws governing prints and casts. The British Fine Arts Copyright Act of 1862, which extended statutory protection to all photographs, is contrasted with French cases, which struggled to accommodate photographs within the fine arts as defined by the copyright law of 1793. [source] Why Christianity Happened: A Sociohistorical Account of Christian Origins (26,50 CE) , By James G. CrossleyCONVERSATIONS IN RELIGION & THEOLOGY, Issue 1 2009Lloyd Pietersen First page of article [source] Writing the History of Humanity: The Role of Museums in Defining Origins and Ancestors in a Transnational WorldCURATOR THE MUSEUM JOURNAL, Issue 1 2005Monique Scott ABSTRACT This article explores the question of how transnational audiences experience anthropology exhibitions in particular, and the natural history museum overall. Of interest are the ways in which natural history museums reconcile anthropological notions of humanity's shared evolutionary history,in particular, African origins accounts,with visitors' complex cultural identities. Through case studies of British, American, and Kenyan museum audiences, this research probed the cultural preconceptions that museum visitors bring to the museum and use to interpret their evolutionary heritage. The research took special notice of audiences of African descent, and their experiences in origins exhibitions and the natural history museums that house them. The article aims to draw connections between natural history museums and the dynamic ways in which museum visitors make meaning. As museums play an increasing role in the transnational homogenization of cultures, human origins exhibitions are increasingly challenged to communicate an evolutionary prehistory that we collectively share, while validating the cultural histories that make us unique. [source] A synopsis of The foundations of mind: Origins of conceptual thought (2004).DEVELOPMENTAL SCIENCE, Issue 5 2004New York: Oxford University Press First page of article [source] A welcome turn to meaning in infant development: commentary on Mandler's The foundations of mind: Origins of conceptual thoughtDEVELOPMENTAL SCIENCE, Issue 5 2004Katherine Nelson No abstract is available for this article. [source] Origins of a stereotype: categorization of facial attractiveness by 6-month-old infantsDEVELOPMENTAL SCIENCE, Issue 2 2004Jennifer L. Ramsey Like adults, young infants prefer attractive to unattractive faces (e.g. Langlois, Roggman, Casey, Ritter, Rieser-Danner & Jenkins, 1987; Slater, von der Schulenburg, Brown, Badenoch, Butterworth, Parsons & Samuels, 1998). Older children and adults stereotype based on facial attractiveness (Eagly, Ashmore, Makhijani & Longo, 1991; Langlois, Kalakanis, Rubenstein, Larson, Hallam & Smooth, 2000). How do preferences for attractive faces develop into stereotypes? Several theories of stereotyping posit that categorization of groups is necessary before positive and negative traits can become linked to the groups (e.g. Tajfel, Billig, Bundy & Flament, 1971; Zebrowitz-McArthur, 1982). We investigated whether or not 6-month-old infants can categorize faces as attractive or unattractive. In Experiment 1, we familiarized infants to unattractive female faces; in Experiment 2, we familiarized infants to attractive female faces and tested both groups of infants on novel faces from the familiar or novel attractiveness category. Results showed that 6-month-olds categorized attractive and unattractive female faces into two different groups of faces. Experiments 3 and 4 confirmed that infants could discriminate among the faces used in Experiments 1 and 2, and therefore categorized the faces based on their similarities in attractiveness rather than because they could not differentiate among the faces. These findings suggest that categorization of facial attractiveness may underlie the development of the ,beauty is good' stereotype. [source] Congress, Kissinger, and the Origins of Human Rights DiplomacyDIPLOMATIC HISTORY, Issue 5 2010Barbara Keys The Congressional "human rights insurgency" of 1973,1977 centered on the holding of public hearings to shame countries engaging in human rights abuses and on legislation cutting off aid and trade to violators. Drawing on recently declassified documents, this article shows that the State Department's thoroughly intransigent response to Congressional human rights legislation, particularly Section 502B, was driven by Kissinger alone, against the advice of his closest advisers. Many State Department officials, usually from a mixture of pragmatism and conviction, argued for cooperation with Congress or for taking the initiative on human rights issues. Kissinger's adamant refusal to cooperate left Congress to implement a reactive, punitive, and unilateral approach that would set the human rights agenda long after the Ford administration left office. [source] Strike at Samu: Jordan, Israel, the United States, and the Origins of the Six-Day War*DIPLOMATIC HISTORY, Issue 1 2008Clea Lutz Bunch First page of article [source] Anglo-American Rivalry and the Origins of U.S. China Policy*DIPLOMATIC HISTORY, Issue 2 2007Macabe Keliher First page of article [source] Between the Old Diplomacy and the New, 1918,1922: The Washington System and the Origins of Japanese-American Rapprochement*DIPLOMATIC HISTORY, Issue 2 2006Sadao Asada First page of article [source] Organizing America: Wealth, Power, and the Origins of Corporate CapitalismECONOMICA, Issue 287 2005Ron Harris No abstract is available for this article. [source] A Brief Commentary on the Hegelian-Marxist Origins of Gramsci's ,Philosophy of Praxis'EDUCATIONAL PHILOSOPHY AND THEORY, Issue 6 2009Debbie J Hill Abstract The specific nuances of what Gramsci names ,the new dialectic' are explored in this paper. The dialectic was Marx's specific ,mode of thought' or ,method of logic' as it has been variously called, by which he analyzed the world and man's relationship to that world. As well as constituting a theory of knowledge (epistemology), what arises out of the dialectic is also an ontology or portrait of humankind that is based on the complete historicization of humanity; its ,absolute "historicism"' or ,the absolute secularisation and earthliness of thought', as Gramsci worded it (Gramsci, 1971, p. 465). Embracing a fully secular and historical view of humanity, it provides a vantage point that allows the multiple and complex effects of our own conceptual heritage to be interrogated in relation to our developing ,nature' or ,being'. The argument presented in this paper is that the legacy of both Hegel and Marx is manifest in the depth of Gramsci's comprehension of what he termed the ,educative-formative' problem of hegemony. It is precisely the legacy of this Hegelian-Marxist radical philosophical critique that is signified in his continuing commitment to the ,philosophy of praxis' and the historical-dialectical principles that underpin this worldview. [source] Vocalizations of Amazon River Dolphins, Inia geoffrensis: Insights into the Evolutionary Origins of Delphinid WhistlesETHOLOGY, Issue 7 2002Jeffrey Podos Oceanic dolphins (Odontoceti: Delphinidae) produce tonal whistles, the structure and function of which have been fairly well characterized. Less is known about the evolutionary origins of delphinid whistles, including basic information about vocal structure in sister taxa such as the Platanistidae river dolphins. Here we characterize vocalizations of the Amazon River dolphin (Inia geoffrensis), for which whistles have been reported but not well documented. We studied Inia at the Mamirauá Sustainable Development Reserve in central Brazilian Amazônia. During 480 5-min blocks (over 5 weeks) we monitored and recorded vocalizations, noted group size and activity, and tallied frequencies of breathing and pre-diving surfaces. Overall, Inia vocal output correlated positively with pre-diving surfaces, suggesting that vocalizations are associated with feeding. Acoustic analyses revealed Inia vocalizations to be structurally distinct from typical delphinid whistles, including those of the delphinid Sotalia fluviatilis recorded at our field site. These data support the hypothesis that whistles are a recently derived vocalization unique to the Delphinidae. [source] Respect and Disrespect: Cultural and Developmental Origins.ETHOS, Issue 1 2010(eds.) San Francisco: Wiley Periodicals, Barbara J. Shwalb, David W. Shwalb, Inc. 2006. No abstract is available for this article. [source] Language Origins , Perspectives and EvolutionEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2007K. A. Jellinger No abstract is available for this article. [source] Prolegomenon to a history of paleoanthropology: The study of human origins as a scientific enterprise.EVOLUTIONARY ANTHROPOLOGY, Issue 5 2004Part 1. Interest in the history of paleoanthropology and the other disciplines related to human origins studies has grown considerably over the last several decades. Some very informative historical surveys have been written by prominent scientists reflecting on the major developments in their fields. Some well-known early examples include Glyn Daniel's The Idea of Prehistory (1962) and The Origins and Growth of Archaeology (1967), which focus primarily on the history of archaeology, Kenneth Oakley's "The problem of man's antiquity: an historical survey" published in the Bulletin of the British Museum (Natural History) [Geology] (1964), and L. S. B. Leakey's Unveiling Man's Origins; Ten Decades of Thought about Human Evolution (1969), with the latter two focusing on the contributions of geology, paleontology, and biology to the problem of human evolution. [source] Molecular Origins of the Mechanical Behavior of Hybrid GlassesADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Mark S. Oliver Abstract Hybrid organic-inorganic glasses exhibit unique electro-optical properties along with excellent thermal stability. Their inherently mechanically fragile nature, however, which derives from the oxide component of the hybrid glass network together with the presence of terminal groups that reduce network connectivity, remains a fundamental challenge for their integration in nanoscience and energy technologies. We report on a combined synthesis and computational strategy to elucidate the effect of molecular structure on mechanical properties of hybrid glass films. We first demonstrate the importance of rigidity percolation to elastic behavior. Secondly, using a novel application of graph theory, we reveal the complex 3-D fracture path at the molecular scale and show that fracture energy in brittle hybrid glasses is fundamentally governed by the bond percolation properties of the network. The computational tools and scaling laws presented provide a robust predictive capability for guiding precursor selection and molecular network design of advanced hybrid organic-inorganic materials. [source] Origins and significance of ergot alkaloid diversity in fungiFEMS MICROBIOLOGY LETTERS, Issue 1 2005Daniel G. Panaccione Abstract Ergot alkaloids are a diverse family of indole-derived mycotoxins that collectively have activities against a variety of organisms including bacteria, nematodes, insects, and mammals. Different fungi accumulate different, often characteristic, profiles of ergot alkaloids rather than a single pathway end product. These ergot alkaloid profiles result from inefficiency in the pathway leading to accumulation of certain intermediates or diversion of intermediates into shunts along the pathway. The inefficiency generating these ergot alkaloid profiles may have been selected for as a means of accumulating a diversity of ergot alkaloids, potentially contributing in different ways to benefit the producing fungus. [source] Origins of Improved Hole-Injection Efficiency by the Deposition of MoO3 on the Polymeric Semiconductor Poly(dioctylfluorene- alt -benzothiadiazole)ADVANCED FUNCTIONAL MATERIALS, Issue 7 2010Yasuo Nakayama No abstract is available for this article. [source] Blue Luminescence of ZnO Nanoparticles Based on Non-Equilibrium Processes: Defect Origins and Emission ControlsADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Haibo Zeng Abstract High concentrations of defects are introduced into nanoscale ZnO through non-equilibrium processes and resultant blue emissions are comprehensively analyzed, focusing on defect origins and broad controls. Some ZnO nanoparticles exhibit very strong blue emissions, the intensity of which first increase and then decrease with annealing. These visible emissions exhibit strong and interesting excitation dependences: 1) the optimal excitation energy for blue emissions is near the bandgap energy, but the effective excitation can obviously be lower, even 420,nm (2.95,eV,<,Eg,=,3.26,eV); in contrast, green emissions can be excited only by energies larger than the bandgap energy; and, 2) there are several fixed emitting wavelengths at 415, 440, 455 and 488,nm in the blue wave band, which exhibit considerable stability in different excitation and annealing conditions. Mechanisms for blue emissions from ZnO are proposed with interstitial-zinc-related defect levels as initial states. EPR spectra reveal the predominance of interstitial zinc in as-prepared samples, and the evolutions of coexisting interstitial zinc and oxygen vacancies with annealing. Furthermore, good controllability of visible emissions is achieved, including the co-emission of blue and green emissions and peak adjustment from blue to yellow. [source] Origins of Improved Hole-Injection Efficiency by the Deposition of MoO3 on the Polymeric Semiconductor Poly(dioctylfluorene- alt -benzothiadiazole)ADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Yasuo Nakayama Abstract The electronic structure of the interfaces formed after deposition of MoO3 hole-injection layers on top of a polymer light-emitting material, poly(dioctylfluorene- alt -benzothiadiazole) (F8BT), is studied by ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy and metastable atom electron spectroscopy. Significant band bending is induced in the F8BT film by MoO3 "acceptors" that spontaneously diffuse into the F8BT "host" probably driven by kinetic energy of the deposited hot MoO3. Further deposition leads to the saturation of the band bending accompanied by the formation of MoO3 overlayers. Simultaneously, a new electronic state in the vicinity of the Fermi level appears on the UPS spectra. Since this peak does not appear in the bulk MoO3 film, it can be assigned as an interface state between the MoO3 overlayer and underlying F8BT film. Both band bending and the interface state should result from charge transfer from F8BT to MoO3, and they appear to be the origin of the hole-injection enhancement by the insertion of MoO3 layers between the F8BT light-emitting diodes and top anodes. [source] Business Improvement Districts: Policy Origins, Mobile Policies and Urban LiveabilityGEOGRAPHY COMPASS (ELECTRONIC), Issue 3 2007Kevin Ward This article reviews the trans-nationalisation of Business Improvement Districts. It outlines the geographical and ideological origins of this much-heralded approach to downtown governance, and the means through which it has found itself in such diverse settings as Cape Town in South Africa, Kru,evac in Serbia and Liverpool in the UK. Analysing the emergence of Business Improvement Districts in terms of the external edges of the state and its internal architecture, on the one hand, and, on the other, in the context of discussions around urban liveability, this article reviews work across geography, planning, political science and sociology. It concludes by arguing that Business Improvement Districts are both interesting in their own right, for what they reveal about contemporary trans-national trends in urban governance, and for what they what they have to say about wider processes of neoliberal urbanisation. [source] The Limits of Design: Explaining Institutional Origins and ChangeGOVERNANCE, Issue 4 2000Paul Pierson Political scientists have paid much more attention to the effects of institutions than to issues of institutional origins and change. One result has been a marked tendency to fall back on implicit or explicit functional accounts, in which the effects of institutions explain the presence of those institutions. Institutional effects may indeed provide part of such an explanation. Yet the plausibility of functional accounts depends upon either a set of favorable conditions at the design stage or the presence of environments conducive to learning or competition. Exploring variability in the relevant social contexts makes it possible to both establish the restricted range of functional accounts and specify some promising lines of inquiry into the subject of institutional origins and change. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||