290 research outputs found

    Doing evolution in economic geography

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    Evolutionary approaches in economic geography face questions about the relationships between their concepts, theories, methods, politics, and policy implications. Amidst the growing but unsettled consensus that evolutionary approaches should employ plural methodologies, the aims here are, first, to identify some of the difficult issues confronting those working with different frameworks. The concerns comprise specifying and connecting research objects, subjects, and levels; handling agency and context; engaging and integrating the quantitative and the qualitative; comparing cases; and, considering politics, policy, and praxis. Second, the purpose is to articulate a distinctive geographical political economy approach, methods, and illustrative examples in addressing these issues. Bringing different views of evolution in economic geography into dialogue and disagreement renders methodological pluralism a means toward improved understanding and explanation rather than an end in itself. Confronting such thorny matters needs to be embedded in our research practices and supported by greater openness; more and better substantiation of our conceptual, theoretical, and empirical claims; enhanced critical reflection; and deeper engagement with politics, policy, and praxis

    Regards français sur l'Amerique: de l'entre-deux-guerres a la Guerre froide

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    Regards français sur l'Amérique : de l'Entre-deux-guerres à la Guerre froide (French Perceptions of America: From the Roaring Twenties to the Cold War) examines the reactions of French intellectuals to various aspects of American culture and politics. Based principally on the writings of contributors to Les Temps modernes, a review founded by Jean-Paul Sartre and Simone de Beauvoir in 1945, this work will examine in great detail the aforementioned co-founders' impressions of the United States as well as the observations of many of Les Temps modernes' contributing writers. Moreover, this dissertation will compare and contrast the views espoused by the Les Temps modernes group with the depictions of the United States exhibited by French thinkers such as André Siegfried, Georges Duhamel, Vladimir Pozner, Frantz Fanon and Bernard-Henri Lévy. This work analyzes these writers' pronouncements on American cultural and political phenomena, including Puritanism, literature, music, race relations, and anticommunism. In light of the above, this dissertation may be considered a study in transcultural perception and the epistemological pitfalls said perception poses. In this regard, people generally judge foreign cultures through the prism of preconceived notions derived in large part from their native culture. This prism, in fact, is a metaphor for the "barriers of otherness" that come into play whenever the act of transcultural perception takes place. This study will examine the effects of these barriers of otherness on the French observers' appreciation of the United States by placing their findings somewhere along a sliding scale ranging from the most objective to the most subjective. The articles by Philippe Soupault and Claude Roy are examples of a relatively objective appraisal of the checks and balances inherent in the way the so-called puritanical moral code is maintained in American society (Chapter 1). At the other end of the scale is the Temps modernes group's totally subjective conjecture on the Rosenberg affair, sparked in large part by the group's Communist sympathies and its stance against the American government (Chapter 5). This study will conclude with a discussion on the varying degrees of certitude associated with various modes of transcultural perception

    Developing a Decision Model for Joint Improvised Explosive Device Defeat Organization (JIEDDO) Proposal Selection

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    This research uses decision analysis to develop a structured, repeatable and most importantly defensible decision model for the evaluation of proposed IED defeat solutions submitted to the Joint IED Defeat Organization (JIEDDO). Additive value models using Value-Focused Thinking (VFT) and the Analytic Hierarchy Process (AHP) are examined as possible methodologies. VFT is determined to be the best fit for JIEDDO\u27s decision situation in which proposals are submitted continuously and must be scored independently of previous proposals. VFT is first used to determine desirable qualities in IED defeat options, and then to generate a hierarchal value model to evaluate these qualities in a selected group of alternatives. The most important criteria for IED defeat proposal evaluation are: Need for the Capability, Operational Effectiveness, and Usability. A group of 30 proposals, previously assessed by the current JIEDDO process, is evaluated suing the VFT decision model and the rank ordered results are compared with JIEDDO\u27s previous selection decisions. The VFT decision model results support JIEDDO\u27s past decisions to accept or reject IED defeat proposals, validating the model. Sensitivity analysis is then conducted to allow further insight to the robustness of the model. The resulting effort creates a decision model that, when consistently applied, provides a repeatable and defensible decision support model that reflects JIEDDO\u27s priorities for proposal selection

    Sub-nanosecond tuning of microwave resonators fabricated on ruddlesden–popper dielectric thin films

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    This is the peer reviewed version of the following article: A. M. Hagerstrom, X. Lu, N. M. Dawley, H. P. Nair, J. Mateu, R. D. Horansky, C. A. E. Little, J. C. Booth, C. J. Long, D. G. Schlom, N. D. Orloff, Adv. Mater. Technol. 2018, 3, 1800090. https://doi-org.recursos.biblioteca.upc.edu/10.1002/admt.201800090, which has been published in final form at https://doi.org/10.1002/admt.201800090. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Voltage-tunable dielectric materials are widely used for microwave-frequency signal processing. Among tunable dielectric thin films, (SrTiO3)nSrO Ruddlesden–Popper (RP) superlattices have exceptionally low loss at high frequencies. This paper reports the first realization of resonators, a ubiquitous building block of microwave components, fabricated on RP films, and an analysis of their static and dynamic tuning behavior. The RP film has a ferroelectric-paraelectric phase transition at ˜200 K, and the tunability is strongest at this temperature. The resonators have approximately 2.5% tuning of the resonance frequency at room temperature and 20% tuning at 200 K, and a tuning time scale of less than a nanosecond, which is limited by the measurement circuit rather than material properties.Peer ReviewedPostprint (author's final draft

    Toolbox of Advanced Atomic Layer Deposition Processes for Tailoring Large-Area MoS2 Thin Films at 150 °C

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    Two-dimensional MoS2 is a promising material for applications, including electronics and electrocatalysis. However, scalable methods capable of depositing MoS2 at low temperatures are scarce. Herein, we present a toolbox of advanced plasma-enhanced atomic layer deposition (ALD) processes, producing wafer-scale polycrystalline MoS2 films of accurately controlled thickness. Our ALD processes are based on two individually controlled plasma exposures, one optimized for deposition and the other for modification. In this way, film properties can be tailored toward different applications at a very low deposition temperature of 150 °C. For the modification step, either H2 or Ar plasma can be used to combat excess sulfur incorporation and crystallize the films. Using H2 plasma, a higher degree of crystallinity compared with other reported low-temperature processes is achieved. Applying H2 plasma steps periodically instead of every ALD cycle allows for control of the morphology and enables deposition of smooth, polycrystalline MoS2 films. Using an Ar plasma instead, more disordered MoS2 films are deposited, which show promise for the electrochemical hydrogen evolution reaction. For electronics, our processes enable control of the carrier density from 6 × 1016 to 2 × 1021 cm–3 with Hall mobilities up to 0.3 cm2 V–1 s–1. The process toolbox forms a basis for rational design of low-temperature transition metal dichalcogenide deposition processes compatible with a range of substrates and applications

    How allosteric control of Staphylococcus aureus penicillin binding protein 2a enables methicillin resistance and physiological function

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    6 pags, 4 figs, 1 tabThe expression of penicillin binding protein 2a (PBP2a) is the basis for the broad clinical resistance to the β-lactam antibiotics by methicillin-resistant Staphylococcus aureus (MRSA). The highmolecular mass penicillin binding proteins of bacteria catalyze in separate domains the transglycosylase and transpeptidase activities required for the biosynthesis of the peptidoglycan polymer that comprises the bacterial cell wall. In bacteria susceptible to β-lactam antibiotics, the transpeptidase activity of their penicillin binding proteins (PBPs) is lost as a result of irreversible acylation of an active site serine by the β-lactam antibiotics. In contrast, the PBP2a of MRSA is resistant to β-lactam acylation and successfully catalyzes the DD-transpeptidation reaction necessary to complete the cell wall. The inability to contain MRSA infection with β-lactam antibiotics is a continuing public health concern. We report herein the identification of an allosteric binding domain - a remarkable 60 Å distant from the DD-transpeptidase active site - discovered by crystallographic analysis of a soluble construct of PBP2a. When this allosteric site is occupied, a multiresidue conformational change culminates in the opening of the active site to permit substrate entry. This same crystallographic analysis also reveals the identity of three allosteric ligands: muramic acid (a saccharide component of the peptidoglycan), the cell wall peptidoglycan, and ceftaroline, a recently approved anti-MRSA β-lactam antibiotic. The ability of an anti-MRSA β-lactam antibiotic to stimulate allosteric opening of the active site, thus predisposing PBP2a to inactivation by a second β-lactam molecule, opens an unprecedented realm for β-lactam antibiotic structure-based design.Work in the United States was supported by National Institutes of Health Grants AI090818 and AI104987, and work in Spain was supported by Grants BFU2011-25326 (from the Spanish Ministry of Economy and Competitiveness) and S2010/BMD-2457 (from the Autonomous Government of Madrid)

    Development of cross-curricular key skills using a 3D immersive learning environment in schools

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    © Springer International Publishing AG 2017. Pedagogical opportunities offered by 3D immersive environments are not restricted to subject-based knowledge but also include non-disciplinary and cross-curricular key skills. This pilot study introduced a large 3D scene of a non-extant architectural exhibition into teaching and learning activities at three UK schools. From observation and qualitative data capture, a comparative case study identified a number of pedagogical opportunities and challenges. Despite diverse teacher and student approaches, a number of common factors were identified including constructionist teaching methods and the suitability of 3D environments for developing cross-curricular key skills and capabilities. In relation to the literature, this paper analyses how subject-aligned use of the 3D model met with differing levels of success, identifies four key skills that emerged from student use of the model across all three schools, and considers how challenges might be translated into further learning opportunities

    The Grizzly, November 19, 1991

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    Founders\u27 Day Excitement • Grizzly Network Career Day • Women\u27s Choices • Volksmarching • Louisiana Election • Service Opportunities for Students • The European Situation • Jonas Salk Addresses Founders Day Convocation • Dr. Takats Awarded the Clamer Chair • Wellness Services Proposal • U.S.G.A. Minutes • Ursinus Continues Helping Habitat • Turkey Drive Needs You • Zack: The Man, The Myth, The Statue • Hocus Pocus a Success • Ursinus Students in Community Production of Gypsy • Movie Review: Hamlet • Battle of the Bands • Rollins Rocks Lower Lounge • Branker Tours to St. Petersburg • CAB Trip to New York • Writing in Good Taste • Magic: One Trick Too Many • Letters: Faculty Members Speak Out; GALA Replies to Letter; Call for Diversity; Publishing the Truth?; Student Reaction to Ronning; Response to Black Hole ; Students React to Social Life • No More Crap! • Filling in the Black Hole • One Professor\u27s Awakening • Lady Bears End Season • Men\u27s Lacrosse Awaits Chance • Women Swimmers Wash Out Washington • Spinella Takes Over as Head Coach of Basketball Team • Dickinson Defeats the Bearshttps://digitalcommons.ursinus.edu/grizzlynews/1284/thumbnail.jp

    How Allosteric Control of Staphylococcus aureus Penicillin-Binding Protein 2a Enables Methicillin-Resistance and Physiological Function

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    The expression of penicillin binding protein 2a (PBP2a) is the basis for the broad clinical resistance to the β-lactam antibiotics by methicillin-resistant Staphylococcus aureus (MRSA). The highmolecular mass penicillin binding proteins of bacteria catalyze in separate domains the transglycosylase and transpeptidase activities required for the biosynthesis of the peptidoglycan polymer that comprises the bacterial cell wall. In bacteria susceptible to β-lactam antibiotics, the transpeptidase activity of their penicillin binding proteins (PBPs) is lost as a result of irreversible acylation of an active site serine by the β-lactam antibiotics. In contrast, the PBP2a of MRSA is resistant to β-lactam acylation and successfully catalyzes the DD-transpeptidation reaction necessary to complete the cell wall. The inability to contain MRSA infection with β-lactam antibiotics is a continuing public health concern. We report herein the identification of an allosteric binding domain - a remarkable 60 Å distant from the DD-transpeptidase active site - discovered by crystallographic analysis of a soluble construct of PBP2a. When this allosteric site is occupied, a multiresidue conformational change culminates in the opening of the active site to permit substrate entry. This same crystallographic analysis also reveals the identity of three allosteric ligands: muramic acid (a saccharide component of the peptidoglycan), the cell wall peptidoglycan, and ceftaroline, a recently approved anti-MRSA β-lactam antibiotic. The ability of an anti-MRSA β-lactam antibiotic to stimulate allosteric opening of the active site, thus predisposing PBP2a to inactivation by a second β-lactam molecule, opens an unprecedented realm for β-lactam antibiotic structure-based design.Fil: Otero, Lisandro Horacio. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Rojas Altuve, Alzoray. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Llarrull, Leticia Irene. University of Notre Dame; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Carrasco López, Cesar. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Kumarasiri, Malika. University of Notre Dame; Estados UnidosFil: Lastochkin, Elena. University of Notre Dame; Estados UnidosFil: Fishovitz, Jennifer. University of Notre Dame; Estados UnidosFil: Dawley, Matthew. University of Notre Dame; Estados UnidosFil: Hesek, Dusan. University of Notre Dame; Estados UnidosFil: Lee, Mijoon. University of Notre Dame; Estados UnidosFil: Johnson, Jarrod W.. University of Notre Dame; Estados UnidosFil: Fisher, Jed F.. University of Notre Dame; Estados UnidosFil: Chang, Mayland. University of Notre Dame; Estados UnidosFil: Mobashery, Shahriar. University of Notre Dame; Estados UnidosFil: Hermoso, Juan A.. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; Españ
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