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Unprecedented
Terms modified by Unprecedented Selected AbstractsUnprecedented [2 + 2]-Cyclodimerization of 1-Aza-1,3,4-trienes: First Representative of 3,4-Diisopropylidenecyclobutane-1,2-dicarbimidothioates.CHEMINFORM, Issue 35 2007N. A. Nedolya Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] TMSCl-Mediated Catalytic Carbocupration of Alkynoates: An Unprecedented and Remarkable Effect of Catalyst Loading on Highly Selective Stereochemical Induction via a TMS-Allenoate Intermediate.CHEMINFORM, Issue 46 2004Michael P. Jennings Abstract For Abstract see ChemInform Abstract in Full Text. [source] Unprecedented in situ Oxidative Ring Cleavage of Isoxazolidines: Diastereoselective Transformation of Nitronic Acids and Derivatives into 3-Hydroxymethyl 4-Nitro Tetrahydrofurans and Pyrrolidines.CHEMINFORM, Issue 40 2004Pierre-Yves Roger Abstract For Abstract see ChemInform Abstract in Full Text. [source] Unprecedented 1,3-Dipolar Cycloaddition of Azomethine Ylides to Ester Carbonyl.CHEMINFORM, Issue 47 2002Mikhail S. Novikov Abstract For Abstract see ChemInform Abstract in Full Text. [source] Rethinking axial patterning in amphibiansDEVELOPMENTAL DYNAMICS, Issue 4 2002Mary Constance Lane Abstract Recent revisions in the Xenopus laevis fate map led to the designation of the rostral/caudal axis and reassignment of the dorsal/ventral axis (Lane and Smith [1999] Development 126:423,434; Lane and Sheets [2000] Dev. Biol. 225:37,58). It is unprecedented to reassign primary embryonic axes after many years of research in a model system. In this review, we use insights about vertebrate development from anatomy and comparative embryology, as well as knowledge about gastrulation in frogs, to reexamine several traditional amphibian fate maps. We show that four extant maps contain information on the missing rostral/caudal axis. These maps support the revised map as well as the designation of the rostral/caudal axis and reassignment of the dorsal/ventral axes. To illustrate why it is important for researchers to use the revised map and nomenclature when thinking about frog and fish embryos, we present an example of alternative interpretations of "dorsalized" zebrafish mutations. © 2002 Wiley-Liss, Inc. [source] Elevated atmospheric CO2 affects soil microbial diversity associated with trembling aspenENVIRONMENTAL MICROBIOLOGY, Issue 4 2008Celine Lesaulnier Summary The effects of elevated atmospheric CO2 (560 p.p.m.) and subsequent plant responses on the soil microbial community composition associated with trembling aspen was assessed through the classification of 6996 complete ribosomal DNA sequences amplified from the Rhinelander WI free-air CO2 and O3 enrichment (FACE) experiments microbial community metagenome. This in-depth comparative analysis provides an unprecedented, detailed and deep branching profile of population changes incurred as a response to this environmental perturbation. Total bacterial and eukaryotic abundance does not change; however, an increase in heterotrophic decomposers and ectomycorrhizal fungi is observed. Nitrate reducers of the domain bacteria and archaea, of the phylum Crenarchaea, potentially implicated in ammonium oxidation, significantly decreased with elevated CO2. These changes in soil biota are evidence for altered interactions between trembling aspen and the microorganisms in its surrounding soil, and support the theory that greater plant detritus production under elevated CO2 significantly alters soil microbial community composition. [source] Six-Membered N-Heterocyclic Carbenes with a 1,1,-Ferrocenediyl Backbone: Bulky Ligands with Strong Electron-Donor Capacity and Unusual Non-Innocent CharacterEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 31 2009Ulrich Siemeling Abstract The stable, crystalline N-heterocyclic diaminocarbene fc[N(CH2tBu)-C-N(CH2tBu)] (2d, fc = 1,1,-ferrocenediyl) was prepared by deprotonation of its formamidinium precursor fc[N(CH2tBu)-CH-N(CH2tBu)][BF4] (1d) and used for the preparation of the 16 valence electron complexes [Mo(2d)(CO)4], [RhCl(2d)(cod)] (cod = 1,5-cyclooctadiene) and [RhCl(2d)(CO)2]. 1d, 2d and [RhCl(2d)(cod)] were structurally characterised by single-crystal X-ray diffraction studies. The electrochemical properties of 2d, its 2-adamantyl analogue 2c, its complex [RhCl(2d)(CO)2] and of the precursors 1d and 1,1,-bis(neopentylamino)ferrocene were investigated by electrochemistry. The carbenes are easily oxidised to the corresponding radical cation, whose persistent nature is unprecedented in the chemistry of N-heterocyclic carbenes. The spin density is located at the Fe atom and the carbene C atom according to the results of EPR spectroscopic studies and DFT calculations.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Cyclic 2:1 and 1:2 Aldehyde-to-Acetone Byproduct Adducts in Aldol Reactions Promoted by Supported Proline-Incorporated CatalystsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2009Lital Tuchman-Shukron Abstract Significant amounts of cyclic byproducts of aldol addition with stoichiometry deviating from a regular 1:1 addition pattern were formed when the reaction of acetone with aromatic aldehydes was promoted by polymer-supported proline-incorporated catalysts. These adducts, unprecedented in the context of the aldol reaction, are most probably formed via a multistep domino mechanism.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] The Treaty of Nice: The Sharing of Power and the Institutional Balance in the European Union,A Continental PerspectiveEUROPEAN LAW JOURNAL, Issue 3 2001Xenophon A. Yataganas This paper presents an initial response to the conclusions of the Nice Summit and the new EU Treaty which emerged from it. It consists of two parts: in the first I discuss the climate in which the Intergovernmental Conference (IGC) took place and the opening positions of the Institutions, the Member States, and the applicant countries. The results achieved at Nice are set out in the second part, with special emphasis on the themes that mark a shift of power within the Community's institutional architecture; i.e. the extension of qualified-majority voting in the Council and the co-decision procedure with the European Parliament, the reweighting of votes and the composition of the Institutions with a view to an enlargement which is both imminent and unprecedented in the history of the EU. I conclude that while the results of the IGC and the new Treaty of Nice fall short of what is needed in an EU with ambitions on a continental scale, they do mark another stage in the process of European integration and the permanent evolution of its constitution. In this sense, the balance of power is likely to be different from what it has been in the past. The Franco-German axis has been severely weakened, the UK and Spain seem to be determined to play a central role, and the smaller countries are seeking to retain some influence over how the process works. New alliances are likely to emerge, particularly after enlargement, with Germany in search of a dominant position, France desperately trying to preserve the status quo, and the UK wanting to influence the direction of moves towards integration from the inside. Nice seems to mark an interim stage in this process. A new IGC has already been scheduled for 2004. There is no doubt that the post-Nice period will be one of transition towards a new distribution of power within the EU, sanctioned by a new, highly constitutional treaty. [source] The Origins of Modern DivorceFAMILY PROCESS, Issue 1 2007STEPHANIE COONTZ High rates of marital dissolution and easy access to divorce are not unprecedented, historically or cross-culturally. But contemporary divorce in North America and Western Europe has different origins and features than divorce in previous cultures. The origins of modern divorce patterns date back more than 200 years, to the invention of the historically unprecedented idea that marriage should be based on love and mutual affection. Ironically, then, the fragility of modern marriage stems from the same values that have elevated the marital relationship above all other personal and familial commitments: the concentration of emotion, passion, personal identity, and self-validation in the couple relationship and the attenuation of emotional attachments and obligations beyond the conjugal unit. The immediate causes of divorce may range from factors as diverse as the personal psychological characteristics of one or both spouses to the stresses of economic hardship and community disintegration. But in a larger perspective, the role of divorce in modern societies and its relatively high occurrence both flow from the same complex of factors that have made good marriages so much more central to people's happiness than through most of the past, and deterioration of a marital relationship so much more traumatic. [source] Charge Generation and Photovoltaic Operation of Solid-State Dye-Sensitized Solar Cells Incorporating a High Extinction Coefficient Indolene-Based SensitizerADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Henry J. Snaith Abstract An investigation of the function of an indolene-based organic dye, termed D149, incorporated in to solid-state dye-sensitized solar cells using 2,2,,7,7,-tetrakis(N,N -di- p -methoxypheny-amine)-9,9,-spirobifluorene (spiro-OMeTAD) as the hole transport material is reported. Solar cell performance characteristics are unprecedented under low light levels, with the solar cells delivering up to 70% incident photon-to-current efficiency (IPCE) and over 6% power conversion efficiency, as measured under simulated air mass (AM) 1.5 sun light at 1 and 10,mW cm,2. However, a considerable nonlinearity in the photocurrent as intensities approach "full sun" conditions is observed and the devices deliver up to 4.2% power conversion efficiency under simulated sun light of 100,mW cm,2. The influence of dye-loading upon solar cell operation is investigated and the thin films are probed via photoinduced absorption (PIA) spectroscopy, time-correlated single-photon counting (TCSPC), and photoluminescence quantum efficiency (PLQE) measurements in order to deduce the cause for the non ideal solar cell performance. The data suggest that electron transfer from the photoexcited sensitizer into the TiO2 is only between 10 to 50% efficient and that ionization of the photo excited dye via hole transfer directly to spiro-OMeTAD dominates the charge generation process. A persistent dye bleaching signal is also observed, and assigned to a remarkably high density of electrons "trapped" within the dye phase, equivalent to 1.8,×,1017,cm,3 under full sun illumination. it is believed that this localized space charge build-up upon the sensitizer is responsible for the non-linearity of photocurrent with intensity and nonoptimum solar cell performance under full sun conditions. [source] Vulnerability of African mammals to anthropogenic climate change under conservative land transformation assumptionsGLOBAL CHANGE BIOLOGY, Issue 3 2006WILFRIED THUILLER Abstract Recent observations show that human-induced climate change (CC) and land transformation (LT) are threatening wildlife globally. Thus, there is a need to assess the sensitivity of wildlife on large spatial scales and evaluate whether national parks (NPs), a key conservation tools used to protect species, will meet their mandate under future CC and LT conditions. Here, we assess the sensitivity of 277 mammals at African scale to CC at 10, resolution, using static LT assumptions in a ,first-cut' estimate, in the absence of credible future LT trends. We examine the relationship between species' current distribution and macroclimatic variables using generalized additive models, and include LT indirectly as a filter. Future projections are derived using two CC scenarios (for 2050 and 2080) to estimate the spatial patterns of loss and gain in species richness that might ultimately result. We then apply the IUCN Red List criteria A3(c) of potential range loss to evaluate species sensitivity. We finally estimate the sensitivity of 141 NPs in terms of both species richness and turnover. Assuming no spread of species, 10,15% of the species are projected to fall within the critically endangered or extinct categories by 2050 and between 25% and 40% by 2080. Assuming unlimited species spread, less extreme results show proportions dropping to approximately 10,20% by 2080. Spatial patterns of richness loss and gain show contrasting latitudinal patterns with a westward range shift of species around the species-rich equatorial zone in central Africa, and an eastward shift in southern Africa, mainly because of latitudinal aridity gradients across these ecological transition zones. Xeric shrubland NPs may face significant richness losses not compensated by species influxes. Other NPs might expect substantial losses and influxes of species. On balance, the NPs might ultimately realize a substantial shift in the mammalian species composition of a magnitude unprecedented in recent geological time. To conclude, the effects of global CC and LT on wildlife communities may be most noticeable not as a loss of species from their current ranges, but instead as a fundamental change in community composition. [source] The Modern State and its AdversariesGOVERNMENT AND OPPOSITION, Issue 1 2006Helen Thompson The modern state would be a crisis if consent to long-established sites of authoritative rule were breaking down, previously capable states were unable to command coercive power, and if the demands of international and supra-national institutions had enforceable claims against historically sovereign states. There is no general crisis of the modern state. The states of most developed countries are secure as sites of authoritative rule, and the military power commanded by the American state is unprecedented. However, the external sovereignty of many poor and small states is diminishing. The cause is not ,globalization' but the policies of the world's dominant state. [source] The End of an Era: What Became of the "Managed Care Revolution" in 2001?HEALTH SERVICES RESEARCH, Issue 1p2 2003Cara S. Lesser Objective. To describe how the organization and dynamics of health systems changed between 1999 and 2001, in the context of expectations from the mid-1990s when managed care was in ascendance, and assess the implications for consumers and policymakers. Data Sources/Study Setting. Data are from the Community Tracking Study site visits to 12 communities that were randomly selected to be nationally representative of metropolitan areas with 200,000 people or more. The Community Tracking Study is an ongoing effort that began in 1996 and is fielded every two years. Study Design. Semistructured interviews were conducted with 50,90 stakeholders and observers of the local health care market in each of the 12 communities every two years. Respondents include leaders of local hospitals, health plans, and physician organizations and representatives of major employers, state and local governments, and consumer groups. First round interviews were conducted in 1996,1997 and subsequent rounds of interviews were conducted in 1998,1999 and 2000,2001. A total of 1,690 interviews were conducted between 1996 and 2001. Data Analysis Methods. Interview information was stored and coded in qualitative data analysis software. Data were analyzed to identify patterns and themes within and across study sites and conclusions were verified by triangulating responses from different respondent types, examining outliers, searching for disconfirming evidence, and testing rival explanations. Principal Findings. Since the mid-1990s, managed care has developed differently than expected in local health care markets nationally. Three key developments shaped health care markets between 1999 and 2001: (1) unprecedented, sustained economic growth that resulted in extremely tight labor markets and made employers highly responsive to employee demands for even fewer restrictions on access to care; (2) health plans increasingly moved away from core strategies in the "managed care toolbox"; and (3) providers gained leverage relative to managed care plans and reverted to more traditional strategies of competing for patients based on services and amenities. Conclusions. Changes in local health care markets have contributed to rising costs and created new access problems for consumers. Moreover, the trajectory of change promises to make the goals of cost-control and quality improvement more difficult to achieve in the future. [source] 2-Hydroxytorularhodin, a New Xanthophyll from the Red Yeast Sporobolomyces coprosmaeHELVETICA CHIMICA ACTA, Issue 11 2005Roland A new hydroxylated carotenoic acid was isolated from the red yeast Sporobolomyces coprosmae and unambiguously identified as 2-hydroxytorularhodin (1), i.e., (all-E)-3,,4,-didehydro-2-hydroxy- ,,, -caroten-16,-oic acid, by application of extensive 1D and 2D NMR techniques (gCOSY, gHSQC, gHMBC, DQS, gTOCSY, and ROESY). Hydroxylation of carotenoids at C(2) is uncommon in nature, very rare in fungi, and unprecedented for torularhodin. [source] Unprecedented Binary Semiconductors Based on TCNQ: Single-Crystal X-ray Studies and Physical Properties of Cu(TCNQX2) X=Cl, BrADVANCED MATERIALS, Issue 9 2010Nazario Lopez Single crystals of a new structure typefor the M+(TCNQ),, binary family are isolated from reactions of dihalogenated TCNQ derivatives and CuI ions (see figure; Cu: pink C: black, N: blue, Br: orange, H: light blue). The new compound Cu(TCNQCl2) exhibits the highest conductivity of the M+(TCNQ),, series to date, despite the larger separation of TCNQCl2 units in the stacks. Conductive properties of Cu(TCNQX2) where X,=,Cl, Br is attributed to charge-carrier transport through copper ions, which is unprecedented in M+(TCNQ),, materials. [source] Servants and citizens: Robert Beale and other Elizabethans*HISTORICAL RESEARCH, Issue 206 2006Patrick Collinson Within the Elizabethan polity, which, given the rule of an unmarried woman with no identified or universally acknowledged successor, was unprecedented and unique, the conviction among the queen's subjects that they were also members of a commonwealth, citizens, which they owed to their educational formation and religious world-view, was reinforced. After briefly examining the careers of a number of public-spirited Elizabethans, members of parliament biographed by the late Joan Henderson, this article focuses on Robert Beale, ardent Protestant, polymath, diplomat and long-serving clerk of the privy council, as the supreme example of a citizen concealed within a royal and loyal servant. [source] A New Level of Hierarchical Structure Control by Use of Supramolecular Self-Assembled Dendronized Block Copolymers,ADVANCED MATERIALS, Issue 23 2008Chaoxu Li Complexation of dendronized block copolymers with sulfate alkyl tails forms unprecedented hierarchically ordered bulk structures, including rectangular-in-lamellar, tetragonal-in-lamellar, hexagonal-in-lamellar and lamellar-in-lamellar. These novel liquid-crystalline morphologies, which can be designed at low length scales in these systems, are expected to provide final materials with not only unprecedented structural complexity, but also tunable physical properties. [source] Classification of synchronous oceanic and atmospheric El Niño-Southern Oscillation (ENSO) events for palaeoclimate reconstructionINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2005Joëlle L. Gergis Abstract Since the mid-1970s, ENSO has changed in character to a predominance of El Niño conditions, the extreme phase of which appears coincidental with increases in global temperature records. Instrumental time series (<150 years) are too short to adequately address the significance of late twentieth-century ENSO variability, thus, multi-century palaeoclimate reconstructions derived from long proxy records are sought. Despite the global influence exerted by ENSO on society, limited consensus exists within the scientific community as to which index best defines the timing, duration and strength of events. Here we address issues associated with the complexity of ENSO characterisation by comparing the ,event capture' ability of two currently used indices of ENSO. It is suggested that the use of a sole ENSO index is undesirable as a given index is only indicative of one physical aspect of the phenomenon, and as such is unlikely to be representative of the wider interactions experienced in the coupled ocean-atmospheric system. In an attempt to describe more of the nature and evolution of ENSO events, the Coupled ENSO Index (CEI) classification scheme was devised to identify synchronous oceanic (Niño 3.4 SST) and atmospheric (Southern Oscillation Index) anomalies associated with ENSO for the instrumental period (1871,2003). The CEI is of practical relevance to the ENSO community as it provides an amplitude preserving instrumental baseline for the calibration of proxy records to reconstruct both components of the ENSO system. Analysis of the nature of instrumental ENSO events from the CEI suggests that the frequency and intensity of post-1970 ENSO events (when 50% of all extreme events identified occur) appears the most anomalous in the context of at least the past century. It is hoped that the CEI will facilitate palaeo-ENSO research to systematically resolve the long-term context of past ENSO behaviour to assess whether the apparently anomalous nature of late twentieth-century variability is unprecedented within existing palaeoclimate archives. Copyright © 2005 Royal Meteorological Society. [source] Giant Room,Temperature Magnetodielectric Response in the Electronic Ferroelectric LuFe2O4ADVANCED MATERIALS, Issue 13 2006A. Subramanian A very large drop in dielectric constant upon application of small magnetic fields is observed at room temperature for LuFe2O4 (see figure). Such behavior is unprecedented and indicates a strong coupling of spins and electric dipoles at room temperature. This behavior of LuFe2O4 is apparently related to its ferroelectricity, which occurs through the highly unusual mechanism of Fe2+ and Fe3+ ordering. [source] New and Easily Accessible Nitrogen Acyclic Gold(I) Carbenes: Structure and Application in the Gold-Catalyzed Phenol Synthesis as well as the Hydration of AlkynesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 8 2010A. Stephen Abstract A series of gold(I) isonitrile complexes were prepared and converted to the corresponding diaminocarbene gold(I) complexes by reactions with primary and symmetrical secondary amines. Twelve crystal structure analyses of the gold(I) complexes could be obtained, in addition NMR studies allowed an analysis of the different diastereomers present in solution. In the gold-catalyzed phenol synthesis these complexes were very successful as pre-catalysts, reaching an unprecedented 3050 turnovers with a problematic substrate. Good conversions in the hydration of phenylacetylene could also be achieved. [source] Arylethyne Bromoboration,Negishi Coupling Route to E - or Z -Aryl-Substituted Trisubstituted Alkenes of ,98% Isomeric Purity.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2010New Horizon in the Highly Selective Synthesis of Trisubstituted Alkenes Abstract The hitherto unprecedented palladium-catalyzed cross-coupling of (Z)-,-bromo-,-arylethenylboranes can be made to proceed satisfactorily through (1) the use of highly catalytically active bis(tri- tert -butylphosphine)palladium or dichloro[N,N -bis-(2,6-diisopropylphenyl)imidazol-2-yl](m -chloropyridine)palladium and (2) conversion of the dibromoboryl group to the (pinacol)boryl group. Thus, a wide variety of carbon groups can be used to substitute bromine in ,98% stereo- and regioselectivity, while suppressing the otherwise dominant ,-debromoboration. Together with the alkylethyne-based protocols, the alkyne bromoboration,Negishi coupling tandem process has emerged as the most widely applicable and highly selective route to trisubstituted alkenes including those that are otherwise difficult to access. [source] The Latinization of the Central Shenandoah ValleyINTERNATIONAL MIGRATION, Issue 1 2008Laura Zarrugh Virginia is among a number of southern states in the United States, such as North Carolina, Arkansas and Georgia, which have experienced a sudden growth in Latino immigration during the past decade. Not only is the volume of growth unprecedented, but many of the destinations are new and located in rural areas. Places that have not hosted immigrant populations for generations are quickly becoming multicultural. The small city of Harrisonburg (population 43,500 according to the 2005 estimate), which is located in the rural Central Shenandoah Valley of Virginia, is perhaps the premier example of this new pattern of change. While local advertising once promoted Harrisonburg for its "99.2% American-born and 93.7% white" population, the area today holds the distinction of hosting the most diverse public school enrollment in the state (in 2006-2007), with students from 64 countries who speak 44 languages. Among them are Spanish speakers from at least 14 different countries. Drawing on social network theory, the paper examines how social networks among Latino immigrants become activated in new settlement areas. It presents a case history of the historic process of "Latinization" involving the settlement of a number of diverse Latino populations (from Mexico, Guatemala, El Salvador, Honduras, Cuba and Uruguay) in Harrisonburg and the surrounding Central Shenandoah Valley. The study demonstrates how a number of key institutions, including local agricultural industries (apples and poultry), a refugee resettlement office and churches recruited "pioneers" from these immigrant groups to the area and how "pioneers" subsequently engaged in further social network recruitment, thus creating multiple transnational "daughter communities" in the Harrisonburg area. The policy implications of this historical process are explored. Au même titre que la Caroline du Nord, l'Arkansas et la Georgie, la Virginie est l'un de ces Etats du sud des Etats-Unis qui ont été témoins d'une poussée soudaine de l'immigration latino-américaine au cours de la dernière décennie. Non seulement il s'agit d'un rythme de croissance sans précédent, mais bon nombre de destinations choisies sont nouvelles et situées en zone rurale. Des lieux qui n'avaient pas accueilli de population immigrée depuis des générations prennent brusquement un caractère multiculturel. La petite ville de Harrisonburg (43 500 habitants selon un décompte approximatif de 2005), qui est située dans la vallée centrale de Shenandoah, en Virginie, est peut-être le principal exemple de cette nouvelle évolution. Alors qu'elle se vantait autrefois d'être composée d'Américains de souche à hauteur de 99,2% et d'être blanche à 93,7%, cette ville se distingue aujourd'hui par la plus grande diversité d'origine des enfants scolarisés à l'échelle de l'Etat (pour la période 2006-2007), puisqu'on y dénombre 64 nationalités parlant 44 langues. On y trouve notamment des hispanophones originaires d'au moins 14 pays différents. A partir de la théorie des réseaux sociaux, l'auteur examine comment ces réseaux se sont activés chez les immigrants latino-américains dans les nouvelles zones d'installation. Il présente un historique du processus de "latinisation", en citant notamment l'installation de populations latino-américaines diverses (originaires du Mexique, du Guatemala, d'El Salvador, du Honduras, de Cuba et d'Uruguay) à Harrisonburg et dans la vallée centrale Shenandoah entourant cette ville. L'auteur montre comment un certain nombre d'institutions clés, et notamment les industries agricoles locales (pommeraies et élevages de poulets), un bureau de réinstallation de réfugiés et des églises ont recruté des "pionniers" au sein de ces groupes d'immigrants, et comment ces "pionniers" ont par la suite poursuivi cette action de recrutement à l'aide de réseaux sociaux, créant ainsi de multiples "communautés affiliées" transnationales dans la région de Harrisonburg. L'étude examine aussi les implications politiques de ce processus historique. Virginia es uno de los estados sureños de los Estados Unidos, al igual que Carolina del Norte, Arkansas y Georgia, que ha experimentado un incremento repentino de la inmigración latina durante el último decenio. No sólo se trata de un incremento sin precedentes, si no que además los destinos son nuevos y localizados en zonas rurales. Estos lugares que no han albergado a poblaciones inmigrantes durante generaciones se están convirtiendo rápidamente en entornos multiculturales. La pequeña ciudad de Harrisonburg (con 43.500 habitantes según el censo de 2005), está localizada en el valle rural central de Shenadoah en Virginia, y es quizás el primer ejemplo de este nuevo patrón de cambio. Si bien la publicidad local promocionaba a Harrisonburg porque sus habitantes eran "99,2 por ciento nacidos en América y 93,7 por ciento blancos" hoy en día se destaca por albergar la población más diversa inscrita en los colegios públicos del Estado (entre 2006 y 2007), con estudiantes provenientes de 64 países que hablan 44 idiomas. Entre ellos están estudiantes de habla hispana provenientes de por lo menos 14 países distintos. Sobre la base de la teoría de redes sociales, este artículo examina redes sociales entre los inmigrantes latinos que se activan en nuevas zonas de asentamiento. Se presenta un estudio por caso de un proceso histórico de "latinización" que implica el asentamiento de toda una variedad de poblaciones latinas de "México, Guatemala, El Salvador, Honduras, Cuba y Uruguay" en Harrisonburg y el valle central aledaño de Shenandoah. El estudio demuestra cómo una serie de instituciones clave,- incluidas las industrias agrícolas locales (manzanos y avicultura), una oficina de reasentamiento de refugiados y las iglesias - reclutaron a los "pioneros" de estos grupos de inmigrantes en la región y cómo esos "pioneros" entablaron ulteriormente el reclutamiento a nivel de su red social, creando "comunidades hermanas" transnacionales y múltiples en la región de Harrisonburg. También se examinan las repercusiones políticas de este proceso histórico. [source] Efficient Hydroformylation in Dense Carbon Dioxide using Phosphorus Ligands without Perfluoroalkyl SubstituentsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Ard C. Abstract Rhodium catalysts modified with triphenylphosphine, triphenyl phosphite, and tris(2,4-di- tert -butylphenyl) phosphite have been evaluated for their performance in the hydroformylation of 1-octene using carbon dioxide as the solvent. It is demonstrated that these catalysts are very efficient for the hydroformylation in carbon dioxide, although they are not designed for use in this medium. In particular, the catalyst prepared in situ from dicarbonyl(2,4-pentanedione)rhodium(I) and tris(2,4-di- tert -butyl-phenyl) phosphite gave rise to an initial turnover frequency in excess of 3×104,molaldehyde,molRh,h,1. Such a reaction rate is unprecedented for hydroformylation in supercritical carbon dioxide-rich reaction mixtures. [source] Transnational Networks and Policy Diffusion: The Case of Gender MainstreamingINTERNATIONAL STUDIES QUARTERLY, Issue 1 2001Jacqui True How can we account for the global diffusion of remarkably similar policy innovations across widely differing nation-states? In an era characterized by heightened globalization and increasingly radical state restructuring, this question has become especially acute. Scholars of international relations offer a number of theoretical explanations for the cross-national convergence of ideas, institutions, and interests. We examine the proliferation of state bureaucracies for gender mainstreaming. These organizations seek to integrate a gender-equality perspective across all areas of government policy. Although they so far have received scant attention outside of feminist policy circles, these mainstreaming bureaucracies,now in place in over 100 countries,represent a powerful challenge to business-as-usual politics and policymaking. As a policy innovation, the speed with which these institutional mechanisms have been adopted by the majority of national governments is unprecedented. We argue that transnational networks composed largely of nonstate actors (notably women's international nongovernmental organizations and the United Nations) have been the primary forces driving the diffusion of gender mainstreaming. In an event history analysis of 157 nation-states from 1975 to 1998, we assess how various national and transnational factors have affected the timing and the type of the institutional changes these states have made. Our findings support the claim that the diffusion of gender-mainstreaming mechanisms has been facilitated by the role played by transnational networks, in particular by the transnational feminist movement. Further, they suggest a major shift in the nature and the locus of global politics and national policymaking. [source] Resource Consumption of New Urban Construction in ChinaJOURNAL OF INDUSTRIAL ECOLOGY, Issue 2 2007John E. Fernández The volume of China's recent additions to its urban-built environment is unprecedented. China now accounts for half of all new building area in the world. Increases in building stocks of all types have occurred during an extended period of accelerated growth of the national economy. This expansion promises to continue through 2030. As a result, the rapid conversion of land from low-density agricultural and light manufacturing to new urban zones of high density and material-intensive commercial and residential buildings has consumed enormous quantities of domestic and imported resources and has irreversibly altered the Chinese landscape. This article examines the consumption of material resources dedicated to Chinese building construction through a survey and analysis of the material intensity of three major building types. This provides a basis for outlining the emerging life-cycle issues of recent additions to the built environment and of continued construction. With this as the starting point, the field of industrial ecology can work toward formulating strategies for a circular economy that include a resource-efficient urban China. [source] New stage in living cationic polymerization: An array of effective Lewis acid catalysts and fast living polymerization in secondsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2007Sadahito Aoshima Abstract Our recent extensive research on Lewis acid catalysts with a weak base for the cationic polymerization of vinyl ethers led to unprecedented living reaction systems: fast living polymerization within 1,3 s; a wide choice of metal halides containing Al, Sn, Fe, Ti, Zr, Hf, Zn, Ga, In, Si, Ge, and Bi; and heterogeneously catalyzed living polymerization with Fe2O3. The use of added bases for the stabilization of the propagating carbocation and the appropriate selection of Lewis acid catalysts were crucial to the success of such new types of living polymerizations. In addition, the base-stabilized living polymerization allowed the quantitative synthesis of star-shaped polymers with a narrow molecular weight distribution via polymer-linking reactions and the precision synthesis and self-assembly of stimuli-responsive block copolymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1801,1813, 2007. [source] Novel tricomponent membranes containing poly(ethylene glycol)/poly(pentamethylcyclopentasiloxane)/poly(dimethylsiloxane) domains,JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2002Pious Kurian Abstract The synthesis and characterization of novel tricomponent networks consisting of well-defined poly(ethylene glycol) (PEG) and poly(dimethylsiloxane) (PDMS) strands crosslinked and reinforced by poly(pentamethylcyclopentasiloxane) (PD5) domains are described. Network synthesis occurred by dissolving ,,,-diallyl PEG and ,,,-divinyl PDMS prepolymers in a common solvent (toluene), introducing a stoichiometric excess of pentamethylcyclopentasiloxane (D5H) to the charge, inducing the cohydrosilation of the prepolymers by Karstedt's catalyst and completing network formation by the addition of water. Water in the presence of the Pt-based catalyst oxidizes the SiH groups of D5H to SiOH functions that immediately polycondense and bring about crosslinking. The progress of cohydrosilation and polycondensation was followed by monitoring the disappearance of the SiH and SiOH functions by Fourier transform infrared spectroscopy. Because cohydrosilation and polycondensation are essentially quantitative, overall network composition can be controlled by calculating the stoichiometry of the three network constituents. The very low quantities of extractable (sol) fractions corroborate efficient crosslinking. The networks swell in both water and hexanes. Differential scanning calorimetry showed three thermal transitions assigned, respectively, to PEG (melting temperature: 46,60 °C depending on composition), PDMS [glass-transition temperature (Tg) = ,,121 °C], and PD5 (Tg = ,,159 °C) and indicated a phase-separated tricomponent nanoarchitecture. The low Tg of the PD5 phase is unprecedented. The strength and elongation of PEG/PD5/PDMS networks can be controlled by overall network composition. The synthesis of networks exhibiting sufficient mechanical properties (tensile stress: 2,5 MPa, elongation: 100,800%) for various possible applications has been demonstrated. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3093,3102, 2002 [source] Fast two-dimensional detection for X-ray photon correlation spectroscopy using the PILATUS detectorJOURNAL OF SYNCHROTRON RADIATION, Issue 5 2009Fabian Westermeier The first X-ray photon correlation spectroscopy experiments using the fast single-photon-counting detector PILATUS (Paul Scherrer Institut, Switzerland) have been performed. The short readout time of this detector permits access to intensity autocorrelation functions describing dynamics in the millisecond range that are difficult to access with charge-coupled device detectors with typical readout times of several seconds. Showing no readout noise the PILATUS detector enables measurements of samples that either display fast dynamics or possess only low scattering power with an unprecedented signal-to-noise ratio. [source] West Nile virus: lessons from the 21st centuryJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 1 2004DACVECC, DACVIM, Pamela A. Wilkins DVM Abstract Introduction: West Nile virus (WNV) first appeared in the United States in 1999, causing illness and death in birds, horses, and humans. While the initial outbreak of this sometimes deadly viral disease was limited to the northeastern United States, the virus had an inexorable migration across the continental United States over the next 3 years, causing huge losses among the affected species. The purpose of this review is to present currently available information regarding the epi-demiology, diagnosis, treatment, and prevention of WNV infection. Veterinarians, particularly those in an emergency practice, serve as an important source of reliable information regarding this disease for animal owners and the public in general. Data sources: Data sources used for the preparation of this review include computer-based searches of PubMed and Commonwealth Agricultural Bureaux (CAB) abstracts. A search in PubMed using ,West Nile' retrieved 1468 ,hits' or references, while a similar search in CAB abstracts produced 815 references. Additional information was obtained from various meeting proceedings, particularly data presented in abstract form, and from the Centers for Disease Control (CDC) website dedicated to WNV. Human data synthesis: Prior to the mid-1990s, reported large-scale epidemics of WNV infection in humans predominantly presented as acute, mild, febrile disease, sometimes associated with lymphadenopathy and skin rash. The recent large epidemic in the United States, in contrast, has prominently featured encephalitis, particularly among the elderly. Additionally, polio-encephalomyelitis-like complications resulting in long-term neurologic sequelae have been reported. There are many WNV-permissive native avian and mosquito hosts in the Unites States and there appear to be few limitations to the spread of the disease in the United States. It is expected that the virus will be identified in all 48 continental states, Mexico, and Canada by the end of 2003. Veterinary data synthesis: The horse is the animal species most affected by the recent WNV epidemic in the United States, and losses to the equine industry have been large and unprecedented. A United States Department of Agriculture (USDA)-approved vaccine against WNV has been in use in horses since 2001 and appears to be effective in limiting the incidence of disease in well-vaccinated populations. WNV infection has been documented in other species of mammals, including camelids (alpaca/llamas) and dogs, and veterinarians should include WNV as a differential diagnosis for animals presenting with clinical signs consistent with central nervous system infection. A large concern exists for endangered bird populations, particularly birds of prey, whether in zoos or in the wild. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||