bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication and Characterization of Highly Ordered Porous Alumina Templates by a Two-Step Anodization Process
Authors: León-Patiño C.A. , Aguilar-Reyes E.A. , Ruiz-Aguilar C.
Published: April 2013

Highly ordered through-hole anodic porous alumina membranes were fabricated by electrochemical oxidation of aluminum in a controlled two-step process. A teflon dispositive was used to ensure single side anodization. Under the most appropriate condition for the fabrication of ideally ordered anodic aluminum oxide (AAO), the voltage used was 15 V during 24 h in a 15 % w/v sulfuric acid solution. SEM, TEM and FESEM characterization shows that the as-fabricated AAO film has a defect-free array of straight parallel channels perpendicular to the surface. The thickness of the porous membrane is 20 microns, approximately. The ordered channels are formed in a honey comb arrange with a pore diameter in the range 20-30 nm, wall thickness of 10-20 nm, interpore distance of 40 nm, and high aspect ratio of 850. The pore density, quantified by image analysis, is 5.4×1010 pore/cm2; perfect ordering was maintained in the full depth of the membrane. Dimensions of this porous structure provide a convenient way to precision engineer the nanoscale morphology.
Elimination of Al4C3 Phase in Al/SiCP Composites by HYSYCVD
Authors: Trujillo-Vázquez E. , Pech-Canul M.I. , González L.A. , López-Honorato E. , Hernández-García H.M.
Published: April 2013

This paper presents results of the microstructure characterization and evaluation of physical and mechanical properties of Al/SiCp composites intentionally containing the Al4C3 phase prepared by pressureless infiltration, as well as results of treating the composites by the hybrid system chemical vapor deposition (HYSYCVD) route using Na2SiF6 as solid precursor. It also contains thermodynamic feasibility calculations (using the HSC 6.1TM program) of possible reactions between the SiFx (x=1-4) gas species (produced during the thermal decomposition of Na2SiF6), Al4C3 and N2 in the atmosphere. The composites were fabricated using an L4 Taguchi experimental design, infiltrating SiCp porous preforms at 1100 and 1200 °C in ultra high purity (UHP) argon and nitrogen (ArN2) atmosphere for 90 and 120 min, with the Al-6Si-16Mg (wt. %) alloy. The specimens were characterized by XRD, SEM and EDS. Results show that the composites exhibit a surface hardness between 63.95 and 86.5 (HR30T) and Young´s modulus up to 118.2 GPa. Application of a post-processing stage by HYSYCVD led to the elimination of Al4C3 and the formation of a coating of stable phases on the composites surface. The experimental results confirm the thermodynamic feasibility of the proposed chemical reactions.
Ag Nanoparticles Adsorption on Diatom-Montmorillonite Clays
Authors: Ruíz-Baltazar A. , Esparza Muñoz Rodrigo Alonso , Pérez R. , Rosas Trejo Gerardo Antonio
Published: April 2013

In this work, a spectroscopic and structural characterization of diatomaceous earth-montmorillonite clays after impregnated with silver nanoparticles were carried out. The silver nanoparticles were synthesized by chemical reduction with sodium borohydride starting from silver nitrate solution. The obtained nanoparticles were stabilized with polyvinyl-pyrrolidone as a surface agent. In order to perform the homogeneous nucleation process, Ag nanoparticles solutions at concentrations of 1, 2 and 4 parts per million were magnetically mixed in the porous material. Additionally, we assessed the porous material adsorption ability of silver by atomic absorption spectroscopy. The quantity of Ag nanoparticles adsorbed by the diatomaceous earth and the adsorption rate as function of the concentration of Ag nanoparticles were established. Other complementary techniques such as X-ray diffraction, infrared spectroscopy and transmission and scanning electron microscopy were used.
Human FcγRII Cytoplasmic Domains Differentially Influence Antibody-Mediated Dengue Virus Infection
Authors: Boonnak Kobporn , Slike Bonnie M. , Donofrio Gina C. , Marovich Mary A.
Published: April 2013

Ab-dependent enhancement (ADE) of dengue virus (DENV) infection is mediated through the interaction of viral immune complexes with FcγRs, with notable efficiency of FcγRII. Most human dengue target cells coexpress activating (FcγRIIa) and inhibitory (FcγRIIb) isoforms, but their relative roles in ADE are not well understood. We studied the effects of FcγRIIa and FcγRIIb by transfecting cells to express each individual receptor isoform or through coexpression of both isoforms. We showed that although both isoforms similarly bind dengue-immune complexes, FcγRIIa efficiently internalized virus leading to productive cellular infection, unlike FcγRIIb. We next focused on the main discriminating feature of these isoforms: their distinct intracytoplasmic tails (FcγRIIa with an immunoreceptor tyrosine-based activation motif [ITAM] and FcγRIIb with an immunoreceptor tyrosine-based inhibitory motif [ITIM]). We engineered cells to express “swapped” versions of their FcγRII by switching the cytoplasmic tails containing the ITAM/ITIM motifs, leaving the remainder of the receptor intact. Our data show that both FcγRIIa and FcγRIIb comparably bind dengue immune complexes. However, wild type FcγRIIa facilitates DENV entry by virtue of the ITAM motif, whereas the swapped version FcγRIIa-ITIM significantly inhibited ADE. Similarly, replacing the inhibitory motif in FcγRIIb with an ITAM (FcγRIIb-ITAM) reconstituted ADE capacity to levels of the wild type activating counterpart, FcγRIIa. Our data suggest that FcγRIIa and FcγRIIb isoforms, as the most abundantly distributed class II Fcγ receptors, differentially influence Ab-mediated DENV infection under ADE conditions both at the level of cellular infection and viral production.
Autoantibody Induction by DNA-Containing Immune Complexes Requires HMGB1 with the TLR2/MicroRNA-155 Pathway
Authors: Wen Zhenke , Xu Lin , Chen Xi , Xu Wei , Yin Zhinan , Gao Xiaoming , Xiong Sidong
Published: April 2013

Anti-dsDNA Ab is reported to be the central pathogenic autoantibody involved in systemic lupus erythematosus (SLE) pathogenesis. However, the mechanisms involved in anti-dsDNA Ab production remain unclear. Recent evidence indicated that DNA-containing immune complexes (ICs) in circulation (termed “circulating DNA-containing ICs”), which are one of the hallmarks of SLE, might be involved in autoantibody production. In this study, we explored their potential role in anti-dsDNA Ab production and the underlying mechanisms in patients with SLE. We demonstrated that circulating DNA-containing ICs were able to induce anti-dsDNA Ab. Of note, HMGB1 in circulating DNA-containing ICs was crucial for anti-dsDNA Ab induction. The HMGB1 content of circulating DNA-containing ICs also correlated positively with anti-dsDNA Ab production in patients with SLE. Further, we revealed that the TLR2/MyD88/microRNA-155 (miR-155) pathway was pivotal for HMGB1 to confer anti-dsDNA Ab induction, and Ets-1 was a functional target of miR-155 in the induction of anti-dsDNA Ab by circulating DNA-containing ICs. Finally, we validated the expression of miR-155 and Ets-1 and their correlation with anti-dsDNA Ab production in patients with SLE. To our knowledge, this is the first report of the crucial role of HMGB1 in autoantibody production mediated by the TLR2/MyD88/miR-155/Ets-1 pathway. These findings identify a novel mechanism to account for the persistent production of anti-dsDNA Ab in SLE and a clue for developing a novel therapeutic strategy against SLE.
Chemical interaction between picritic magmas and upper crust along the margins of the Muskox intrusion, Northwest Territories
Authors: Francis D
Published: April 2013

The contact between the Muskox intrusion and its gneissic host rocks is exposed from a narrow Keel dyke in the south to a large layered chamber in the north. The presence of granophyric textures, elevated ratios of large-ion lithophile (LIL) to high
field-strength (HFS) elements, and enhanced orthopyroxene crystallization along the margin of the layered series indicate that the early magmas of the chamber were contaminated by their gneissic host rocks. The margins of the lower two megacycles indicate that the contamination was selective, with
the extent of chemical exchange between Muskox magmas and host paragneiss increasing in the order: HFS elements, heavy rare-earth elements, light rare-earth elements, U, Th, LIL elements, and chalcophile elements. Two distinct hybrid magmas were simultaneously forming along the margin of the
chamber, one a hypersthene-normative basalt produced by the contamination of Muskox magma and the other a high-Al basalt to andesite, produced by the metasomatic melting of the host paragneiss. These buoyant hybrid magmas rose from the margin to form layers of contaminated magma along the roof of
the magma chamber during each megacycle. Following the sealing of the margins with cumulates, these layers remained relatively isolated from the underlying magma of the chamber until the crystallization of feldspar in the lower two megacycles. Anomalous LIL/HFS element ratios associated with
enhanced crystallization of orthopyroxene in Megacycles #3 and #4 indicate, however, that episodic mixing began to occur as the Muskox chamber matured.
Using n-Grams for Syndromic Surveillance in a Turkish Emergency Department without English Translation: A Feasibility Study
Authors: Halász Sylvia , Brown Philip , Oktay Cem , Çevik Arif Alper , Kılıçaslan Isa , Goodall Colin , Cochrane Dennis G , Fowler Thomas R , Jacobson Guy , Tse Simon , Allegra John R
Published: April 2013

Introduction: Syndromic surveillance is designed for early detection of disease outbreaks. An important data source for syndromic surveillance is free-text chief complaints (CCs), which are generally recorded in the local language. For automated syndromic surveillance, CCs must be classified into predefined syndromic categories. The n-gram classifier is created by using text fragments to measure associations between chief complaints (CC) and a syndromic grouping of ICD codes.

Objectives: The objective was to create a Turkish n-gram CC classifier for the respiratory syndrome and then compare daily volumes between the n-gram CC classifier and a respiratory ICD-10 code grouping on a test set of data.

Methods: The design was a feasibility study based on retrospective cohort data. The setting was a university hospital emergency department (ED) in Turkey. Included were all ED visits in the 2002 database of this hospital. Two of the authors created a respiratory grouping of International Classification of Diseases, 10th Revision ICD-10-CM codes by consensus, chosen to be similar to a standard respiratory (RESP) grouping of ICD codes created by the Electronic Surveillance System for Early Notification of Community-based Epidemics (ESSENCE), a project of the Centers for Disease Control and Prevention. An n-gram method adapted from AT&T Labs’ technologies was applied to the first 10 months of data as a training set to create a Turkish CC RESP classifier. The classifier was then tested on the subsequent 2 months of visits to generate a time series graph and determine the correlation with daily volumes measured by the CC classifier versus the RESP ICD-10 grouping.

Results: The Turkish ED database contained 30,157 visits. The correlation ( R2) of n-gram versus ICD-10 for the test set was 0.78.

Conclusion: The n-gram method automatically created a CC RESP classifier of the Turkish CCs that performed similarly to the ICD-10 RESP grouping. The n-gram technique has the advantage of systematic, consistent, and rapid deployment as well as language independence.
Oxidative Stress and DNA Damage Induced by Chromium in Liver and Kidney of Goldfish, Carassius auratus
Authors: Velma Venkatramreddy , Tchounwou Paul B.
Published: April 2013

Chromium (Cr) is an abundant element in the Earth's crust. It exhibits various oxidation states, from divalent to hexavalent forms. Cr has diverse applications in various industrial processes and inadequate treatment of the industrial effluents leads to the contamination of the surrounding water resources. Hexavalent chromium (Cr (VI)) is the most toxic form, and its toxicity has been associated with oxidative stress. The present study was designed to investigate the toxic potential of Cr (VI) in fish. In this research, we investigated the role of oxidative stress in chromium-induced genotoxicity in the liver and kidney cells of goldfish, Carassius auratus. Goldfish were acclimatized to the laboratory conditions and exposed them to 5% and 10% of 96 hr-LC50 (85.7 mg/L) of aqueous Cr (VI) in a continuous flow through system. Fish were sampled every 7 days for a period of 28 days to analyze the lipid hydroperoxides (LHP) levels and genotoxic potentials in the liver and kidney. LHP levels were analyzed by spectrophotometry while genotoxicity was assessed by single cell gel electrophoresis (comet) assay. LHP levels in the liver increased significantly at week 1, followed by a decrease. LHP levels in the kidney increased significantly at weeks 1, 2, and 3, and decreased at week 4 compared to the control. The percentage of DNA damage increased in both liver and kidney at both test concentrations. The results clearly indicate that Cr (VI) induces significant levels of DNA damage in liver and kidney cells of goldfish. The induced LHP levels in both organs were concentration-dependent and were directly correlated with the levels of DNA damage. The two tested Cr (VI) concentrations induced significant levels of oxidative stress in both organs, however the kidney appears to be more vulnerable and sensitive to Cr-induced toxicity than the liver.
Pharmacotherapies for COPD
Authors: Ejiofor Stan , Turner Alice M.
Published: April 2013

This review article summarizes the main treatments for chronic obstructive pulmonary disease, their mechanisms, and the key evidence from trials supporting their use. Drug classes covered were short acting beta agonists (SABA), short acting muscarinic antagonists (SAMA), long acting beta agonists (LABA), long acting antimuscarinics (LAMA), inhaled corticosteroids (ICS), LABA/ ICS combinations, specific phosphodiesterase (PDE4) inhibitors, non-specific PDE inhibitors, mucolytics, and oxygen. Non-specific therapies, such as opiates for relief of dyspnoea and therapies for smoking cessation, are also covered briefly. For each class of drug, mechanisms of action are described, key clinical trial results are reported, and available agents compared. Finally, the place of each drug in therapy is compared between current worldwide guidelines.
Soil nitrogen dynamics following herbicide kill and tillage of manured and unmanured grasslands
Authors: Chantigny Martin H. , MacDonald J. Douglas , Angers Denis A. , Rochette Philippe , Royer Isabelle , Gasser Marc-Olivier
Published: April 2013

Chantigny, M. H., MacDonald, J. D., Angers, D. A., Rochette, P., Royer, I. and Gasser, M.-O. 2013. Soil nitrogen dynamics following herbicide kill and tillage of manured and unmanured grasslands. Can. J. Soil Sci. 93: 229–237. Grassland soils accumulate N, which could be lost following land-use change. Adjacent grassland sites, with and without liquid swine manure applied annually for 28 yr, were subdivided and left undisturbed (Control), or killed by herbicides with and without full inversion tillage (FIT) in the autumn or spring. We monitored hot-water extractable organic N (HWEON), and mineral N forms in KCl extractions and soil solutions (tension lysimeters) for 1 yr. Mean soil mineral N increased by 1 to 2.8 g m−2 in the weeks following herbicide kill and FIT of the unmanured soils, and by 2.6 to 3.0 g m−2 in the manured soil. These increases corresponded to declines in soil HWEON (−0.4 to −1.9 g m−2 unmanured site; −2.4 to −4.9 g m−2 manured site), suggesting that HWEON comprised N that is rapidly mineralized following grassland termination. More than 80% of N mineralized in the weeks following termination accumulated as NH4 in the unmanured soils, compared with >70% as NO3 in the manured soils. As a result, more mineral N (mainly NO3) was found in the soil solution of manured soils. Manured grassland soils may represent a high risk of N loss following termination with herbicide in combination with FIT in the autumn, because of the rapid nitrification of mineralized N. For spring FIT, however, the rapid mineralization of soil N may represent a substantial nutrient source to the following crop.
Vivaspin ultrafiltration: A new approach for high resolution measurements of colloidal and soluble iron species
Authors: Schlosser Christian , Streu Peter , Croot Peter L.
Published: April 2013

Vivaspin6® ultrafiltration units with molecular weight “cut‐off” membranes of 5, 10, 30, 50, and 100 kDa were used together to examine the size distribution of newly formed iron (Fe) colloids in natural seawater samples and in the presence of several different Fe chelators with varying Fe binding strength. Artificial Fe chelators, such as TAC, and 2 kDG, when added at equimolar levels to Fe, supported the formation of a continuum of Fe‐ligand colloids between 5 and 100 kDa. More than 90% of the added 55Fe in these solutions occurred in Fe aggregates/particles larger than 100 kDa. The strong siderophore DFO held the majority of the added 55Fe in the “truly” soluble fraction ≤ 5 kDa, whereas 90% of 55Fe added to UV‐irradiated seawater was converted into Fe colloids with a size between 50 to 100 kDa (5–6 nm). Membranes with ≥ 10 kDa showed similar “cut‐off” properties on natural seawater samples collected in the water column off the Peruvian coast. Fe solubility determined with these membranes was approximately six times greater than Fe solubility determined with the 5 kDa membrane and the 0.02 µm syringe filters. This suggests that a seamless size continuum of organic chelators (≤5 kDa‐10 kDa) is present in these seawaters and that estimates of ligand production based on 0.02 µm Anotop solubility experiments underestimates the abundance of soluble/colloidal ligands. Regarding these results, we recommend the use of Vivaspin 5 kDa membranes to separate the “truly” soluble from the colloidal Fe fraction.
A prática pedagógica no ensino de biblioteconomia: interação e colaboração no contexto da web 2.0
Authors: Araújo Ronaldo Ferreira
Published: April 2013

Apresenta breves considerações sobre a inserção das tecnologias de informação e comunicação no trabalho docente do ensino de Biblioteconomia no Brasil e aborda a prática pedagógica na área a partir dos suportes tecnológicos com ênfase no uso de recursos da web 2.0 no apoio ao processo de ensino e aprendizagem. Com o intuito de contribuir com a discussão descreve um experimento, baseado em uma prática pedagógica interativa, desenvolvido durante a realização da disciplina “Informática aplicada à Biblioteconomia II” do curso de graduação em Biblioteconomia da Universidade Federal de Alagoas (UFAL) no primeiro semestre do ano de 2011. Por meio de uma abordagem netnográfica, as discussões em torno da disciplina postadas no microblog Twitter foram monitoradas, com o propósito de averiguar a possibilidade do uso de recursos da web 2.0 como aportes metodológicos ao ensino da disciplina. Ao todo foram identificados 514 tweets e pelo perfil de compartilhamento (distribuição das mensagens por mês, dia da semana e horário do dia) e das conversações estabelecidas (mentions, replies, e retweets) considera que a ferramenta utilizada confirma a lógica de um recurso baseado no contexto da web 2.0, que por sua premissa de interação e colaboração, facilita a participação e engajamento dos alunos na disciplina. A aprendizagem distributiva e contínua na qual o assunto discutido ultrapassou as limitações espaço-temporal da sala de aula foi identificada, bem como o envolvimento ativo e exercício da autonomia por parte dos alunos. Conclui-se que, pensar a educação no contexto de uma constante evolução tecnológica altera de forma significativa as práticas pedagógicas e exige uma postura de contínua reformulação do trabalho docente
Os sistemas de proteção de direito digital (DRM): tecnologias e tendências para e-books
Authors: Ianzen Adriane , De Paula Pinto José Simão , Wildauer Egon Walter
Published: April 2013

Resultado de um estudo exploratório este artigo apresenta uma discussão acerca do uso de sistemas de gerenciamento de direitos autorais em arquivos digitais, focando sua aplicação em e-books. Apresenta-se o cenário dos e-books, sua conceituação, a base legal autoral, o direito digital, para então adentrar na tecnologia que provê o desenvolvimento dos sistemas de DRM. Alguns tipos de DRM são expostos, bem como sua arquitetura básica e componentes mínimos necessários são apresentados. Ao final, apresentam-se considerações de que há a necessidade de nova postura dos agentes envolvidos para uma real evolução do setor.
Folksonomia: a linguagem das tags
Authors: Assis Juliana de , Moura Maria Aparecida
Published: April 2013

A radicalização do potencial colaborativo da web atual aponta uma tendência de personalização da recuperação da informação através de ferramentas que exploram a linguagem natural na representação e no compartilhamento de conteúdos ao longo das redes sociais. Tal configuração sócio-técnica traz desafios aos profissionais da informação tanto para a descrição e compreensão dos fenômenos informacionais que ocorrem neste âmbito, quanto para a elaboração de produtos e serviços voltados para um usuário que se apresenta cada vez mais como sujeito informacional ao assumir um papel ativo diante da complexidade que caracteriza a organização da informação em contextos digitais. Este artigo apresenta conclusões de pesquisa, relacionadas às analises da linguagem utilizada em três ambientes colaborativos que utilizam a folksonomia (Social Tagging Systems). A partir de uma perspectiva fundamentada na Semiótica e na Análise de Redes Sociais, são identificadas e descritas as principais manifestações da linguagem gerada e compartilhada pelas redes sociais através destes ambientes.
Trend analysis of tropospheric NO2 column density over East Asia during 2000–2010: multi-satellite observations and model simulations with the updated REAS emission inventory
Authors: Itahashi S. , Uno I. , Irie H. , Kurokawa J. , Ohara T.
Published: April 2013

Abstract. Satellite observations of the tropospheric NO2 vertical column density (VCD) are closely correlated to surface NOx emissions and can thus be used to estimate the latter. In this study, the NO2 VCDs simulated by a regional chemical transport model with data from the updated Regional Emission inventory in ASia (REAS) version 2.1 were validated by comparison with multi-satellite observations (GOME, SCIAMACHY, GOME-2, and OMI) between 2000 and 2010. Rapid growth in NO2 VCD driven by expansion of anthropogenic NOx emissions was revealed above the central eastern China region, except during the economic downturn. In contrast, slightly decreasing trends were captured above Japan. The modeled NO2 VCDs using the updated REAS emissions reasonably reproduced the annual trends observed by multi-satellites, suggesting that the NOx emissions growth rate estimated by the updated inventory is robust. On the basis of the close linear relationship of modeled NO2 VCD, observed NO2 VCD, and anthropogenic NOx emissions, the NOx emissions in 2009 and 2010 were estimated. It was estimated that the NOx emissions from anthropogenic sources in China beyond doubled between 2000 and 2010, reflecting the strong growth of anthropogenic emissions in China with the rapid recovery from the economic downturn during late 2008 and mid-2009.
Brief communication "The 2013 Erebus Glacier tongue calving event"
Authors: Stevens C. L. , Sirguey P. , Leonard G. H. , Haskell T. G.
Published: April 2013

Abstract. The Erebus Glacier Tongue, a~small floating glacier in southern McMurdo Sound, is one of the best-studied ice tongues in Antarctica. Despite this, its calving on the 27 February 2013 (UTC) was around 10 yr earlier than previously predicted. The calving was likely a result of ocean currents and the absence of fast ice. The subsequent trajectory of the newly-created iceberg supports previous descriptions of the surface ocean circulation in southern McMurdo Sound.
Patients’, nurses’ and physicians’ perception of delays in emergency department care
Authors: Downey La Vonne A. , Zun Leslie S. , Burke Trena
Published: April 2013

Background: Patients often judge their experiences in the emergency department (ED) based upon how long they have to wait, the attitudes of staff, and the information provided them. Objective: The objective of this study was to assess the causes in constraints to patient flow in emergency departments by comparing staff, patient, and DSS data findings. Methods: A random sample of patients and their healthcare providers were administered a survey asking them to rank the reasons for delay during three points after triage (60, 120, 180 minutes). A comparison was then done using Spearman’s rank correlations and a regression model with independent indicators collected from the hospitals Decision Support System (DSS) which included: time to be seen by doctors, time to laboratory test results, time for radiological results, wait time for hospital bed and discharge in order to compare if the perceptions of constraints are related to the actual reasons for delays in the ED. This study was approved by the Internal Review Board. Results: There was a significant correlation in the ranking of the reason for delays within the first, second and third hours between patients, nurses and doctors. However, when comparing perceptions for delay and independent data, only nurses within the third hour were correct in their understanding of the constraints that lead to delays. Conclusions: Overall, patients and staff view similar reasons for constraints to their timely flow through the ED. There is, however, very little correlation between the survey responses and the independent factors that did constrain the flow of the ED. A more extensive use and integration of the DSS system by staff could provide more reliable information for reasons for delay that could be communicated to the ED patients which could improve customer service.
Development of Underactuated Prosthetic Fingers with Joint Locking and Electromyographic Control
Authors: Peerdeman Bart , Stramigioli Stefano , Hekman Edsko E. G. , Brouwer Dannis M. , Misra Sarthak
Published: April 2013

Modern hand prostheses possess a large number of degrees of freedom. These degrees of freedom cannot simply be actuated by a single motor each, since their combined size and weight would exceed the limitations of an anthropomorphic prosthesis. Some hand prostheses try to remedy this by way of underactuation of the fingers or addition of entirely passive fingers, but this reduces the hand's ability to execute different grasp types. We present a joint locking system, allowing certain degrees of freedom to be fixed during actuation of an underactuated finger. These locks are actuated by miniature solenoids, and allow the fingers to support a variety of grasp types. In this paper, these locks are implemented in a two-fingered prosthesis prototype, which is able to perform several grasping motions important for prosthesis users. This prototype is controlled by pre-recorded electromyographic signals, which control different grasp types and their opening/closing. Various grasping experiments show that the prototype is able to execute three essential grasp types for daily living with a single main actuator, and can be intuitively controlled by means of six different electromyographic signals. This prototype demonstrates new joint locking mechanisms and control systems that can provide an anthropomorphic, myoelectric hand prosthesis with minimal actuation and intuitive control.
Una Aproximación Tradicional y Multicultural a la Ética Ambiental en la Educación Escolar Primaria y Secundaria
Authors: Hargrove Eugene C. ,   Center for Environmental Philosophy, The University of North Texas
Published: April 2013

La enseñanza de la ética ambiental en la educación escolar es muy difícil si no se modifican las perspectivas positivistas, y si no se adapta la enseñanza a cada cultura y región. Un buen punto de partida (y poco controvertido) sería comenzar con aquellos valores considerados en las leyes ambientales regionales. Así, los profesores enseñarían la historia de las ideas asociadas a estos valores, y su relación con la temática ambiental. Este enfoque es necesario para contrarrestar la aproximación valórica de la economía moderna, que considera a los "valores no-económicos"como meras expresiones de emociones personales. La aproximación multicultural puede contribuir a clarificar valores tradicionales, que en aquellos países con poblaciones indígenas incluyen valores originados a partir de diferentes historias de las ideas (tales como los valores de los pueblos indígenas en Canadá o los Mapuche en Chile), y puede promover un mejor entendimiento entre diferentes grupos sociales.
Filosofía No Confinada
Authors: Frodeman Robert ,   Center for Environmental Philosophy, The University of North Texas
Published: April 2013

Desafíos ambientales como aquellos que enfrenta la región del Cabo de Hornos en Chile, superan la competencia de cualquier marco disciplinario. Las aproximaciones interdisciplinarias al conocimiento, combinando la pericia de varias disciplinas, como también las perspectivas transdisciplinarias de los sectores público y privado, requieren un elemento unificador que permita integrar perspectivas tan dispares. El campo de la filosofía, que tradicionalmente ha ofrecido una visión del conocimiento en su totalidad, puede cumplir nuevamente esta función si los filósofos están dispuestos a adoptar una expresión des-disciplinaria de la filosofía.
Exploring Logarithms with a Ruler
Authors: Ostler Elliott
Published: April 2013

Processes using linear measurement can be adapted to teach complex topics such as polynomial multiplication, rational exponents, and logarithms.
A Model for Spatially Varying Crime Rates in English Districts: The Effects of Social Capital, Fragmentation, Deprivation and Urbanicity
Authors: Congdon Peter Douglas
Published: April 2013

Geographic variations in crime are often linked to aspects of urban social structure that are latent constructs, not directly observed but instead proxied by a range of observed indicators. Examples are area deprivation and urbanicity, both established risk factors for crime. Little UK based evidence exists for impacts on crime of other potentially relevant influences such as social capital and social fragmentation, which are also latent constructs. Other cited influences on area crime differences include income inequality, but there may be further unobserved factors, which tend to be spatially correlated. The present paper seeks to establish, using appropriate multivariate and spatial regression techniques, the relative importance of social capital, fragmentation, deprivation, urbanicity and income inequality in an analysis of recent crime variations between 324 English Local Authority Districts. Variations in total, violent and property crime are considered.
Deforestation
Authors: Meyfroidt Patrick
Published: April 2013

Forests are sources of wood, food, and other non‐timber forest products. They provide multiple ecosystem services including carbon sink and storage, habitats for biodiversity, preservation of soils, regulation of hydrological cycles, and micro‐and regional climates. Deforestation is the largest single anthropogenic transformation of natural ecosystems, with large impacts on all these goods and services. Concern about forests and deforestation has long been framed through the issue of sustaining timber resources. Starting in the 1980s, loss and preservation of biodiversity in tropical forests became a dominant topic in the public debate. More recently, the role of forests in climate regulation, and deforestation as a source of greenhouse gas emissions driving climate change, has been emphasized.
Ethnic identity
Authors: Horowitz Adam L.
Published: April 2013

Ethnicity is a conceptual process used in the United States to categorize people into groups. The notion that these categories become relevant in defining self‐concept for the people within each category is the basis of ethnic identity. What constitutes ethnic identity, however, is a matter of immense, yet important, uncertainty.
Indymedia
Authors: Pickard Victor
Published: April 2013

New global communication technologies have led to new socio‐political formations defined by their reliance on Internet strategies, participatory practices, and network social structures.Indymedia(also referred to as the Independent Media Center, or IMC) exemplifies all of these trends. Although Indymedia's early influences trace back at least as far as the 1990s media democracy movement, it first took shape within the global justice movement at the turn of the twenty‐first century. The first IMC was founded during the November 1999 World Trade Organization protests – the “Battle of Seattle” – to circumvent mainstream commercial media coverage of activist issues, and it was soon replicated in over 150 sites across six continents in some 30 languages. Guided by the principle of “be the media,” the Indymedia model is defined by grassroots journalism, an interactive community news web site, a global network, and a radical democratic organization.
Dollarization
Authors: Fields David , Vernengo Matías
Published: April 2013

The expression “dollarization” has at least two different meanings. In the narrow sense, it refers to massive currency substitution, in which a country, most likely a developing one, supplements its domestic unit account of fiduciary reserve assets with a foreign currency, more often than not the US dollar or, in some cases, the euro. Note that currency substitution could be complete and might even imply the elimination of a domestic token. Full dollarization in that sense has taken place in small countries, mostly in Latin America, the Caribbean, and the Pacific, which are heavily dependent on the United States. Dollarization, in this sense, is the exemplification of a country foregoing its national “monetary sovereignty”.
Food
Authors: Inglis David
Published: April 2013

Globalization processes have entailed many profound changes as to how food is produced, distributed, prepared, eaten, shared, imagined, discussed, and fought over in different parts of the world. Given the centrality of food, both as material artifact and emotionally laden symbol, to human existence, it is important to examine food in light of globalization and globalization in light of food.
Cyberconflict
Authors: Bronk Chris
Published: April 2013

Cyberconflict is the pursuit of political disagreement or argument in cyberspace, a wholly human‐constructed environment in which communication over computer networks occurs. The magnitude of cyberconflict can vary, as the means and motivations of those engaging in such conflict can extend from quite modest to substantial. Additionally, the actors engaged in cyberconflict can vary as well. Individuals, groups, organizations, and states may choose to attack others of their own type or differing actors. An individual may choose to engage in conflict with an organization, or a state with a group.
Coupling of Micromagnetic and Structural Properties Across the Martensite and Curie Temperatures in Miniaturized Ni‐Mn‐Ga Ferromagnetic Shape Memory Alloys
Authors: Jakob A. M. , Hennes M. , Müller M. , Spemann D. , Mayr S. G.
Published: April 2013

Micromagnetic structure evolution in Ni‐Mn‐Ga ferromagnetic shape memory thin films is investigated by means of temperature dependent magnetic force microscopy (TD‐MFM). The center of interest is the magnetic properties of epitaxial Ni‐Mn‐Ga thin films on MgO substrates across thermally induced phase transitions. Experimental results are discussed within the framework of competing magnetic interactions arising in stressed thin ferromagnetic films. Measurements on 14M martensite specimens are supplemented by three‐dimensional micromagnetic simulations. Corresponding calculated MFM micrographs are compared to experimental data. The influence of twin variant dimension and orientation on micromagnetic domain formation and wall structure is depicted from a theoretical point of view. A micromagnetic model system of partial flux closure is proposed and calculated analytically to estimate a stress induced magneto crystalline anisotropy constant in austenite Ni‐Mn‐Ga.
A Versatile Light‐Switchable Nanorod Memory: Wurtzite ZnO on Perovskite SrTiO3
Authors: Bera Ashok , Peng Haiyang , Lourembam James , Shen Youde , Sun Xiao Wei , Wu T.
Published: April 2013

Integrating materials with distinct lattice symmetries and dimensions is an effective design strategy toward realizing novel devices with unprecedented functionalities, but many challenges remain in synthesis and device design. Here, a heterojunction memory made of wurtzite ZnO nanorods grown on perovskite Nb‐doped SrTiO3 (NSTO) is reported, the electronic properties of which can be drastically reconfigured by applying a voltage and light. Despite of the distinct lattice structures of ZnO and NSTO, a consistent nature of single crystallinity is achieved in the heterojunctions via the low‐temperature solution‐based hydrothermal growth. In addition to a high and persistent photoconductivity, the ZnO/NSTO heterojunction diode can be turned into a versatile light‐switchable resistive switching memory with highly tunable ON and OFF states. The reversible modification of the effective interfacial energy barrier in the concurrent electronic and ionic processes most likely gives rise to the high susceptibility of the ZnO/NSTO heterojunction to external electric and optical stimuli. Furthermore, this facile synthesis route is promising to be generalized to other novel functional nanodevices integrating materials with diverse structures and properties.
The Copolymer of Poly(2‐dimethylaminoethyl methacrylate) and Methacrylated Chondroitin Sulfate with Low Cytotoxicity for Gene Delivery
Authors: Lo Yu‐Lun , Wang Yao‐Sheng , Wang Li‐Fang
Published: April 2013

Poly(2‐dimethylaminoethyl methacrylate) (PDMAEMA) is one of the most potent synthetic nonviral gene‐delivery vectors because of its high transfection efficiency. However, the cytotoxicity of PDMAEMA is a major concern for its clinical applications. An anionic crosslinker is synthesized based on a natural polysaccharide, chondroitin sulfate (CS), by introducing methacrylate groups (CSMA). By systematically adjusting the substitution degree of methacrylation on CS and the weight percent of CSMA and PDMAEMA, sol‐type copolymers are obtained as a gene‐delivery vector. The combination of CS and PDMAEMA is expected not only to reduce the cytotoxicity of PDMAEMA, but also to facilitate better transfection efficiency than PDMAEMA because of the recognition of CS by CD44 receptors on cell surfaces. Two CSMA‐modified PDMAEMA copolymers with different CSMA constituents are selected and their polyplexes prepared with plasmid DNA. The cytotoxicity and gene transfection efficiency of the polyplexes are tested and compared with those of PDMAEMA/pDNA. The copolymers of CSMA and PDMAEMA show significantly improved cell viability as compared with PDMAEMA. Their formed polyplexes with pDNA also show lower cytotoxicity than does PDMAEMA/pDNA. The transfection efficiency remarkably increases as the CSMA‐modified PDMAEMA/pDNA polyplex is prepared at a weight ratio of 2.4. The internalization mechanism of CSMA‐modified PDMAEMA/pDNA in HEK 293T cells is mainly based on caveolae‐mediated endocytosis. However, both caveolae‐mediated and CD44‐mediated endocytosis mechanisms are involved in U87 cells.
Hybrid Plasmonic–Photonic Nanostructures: Gold Nanocrescents Over Opals
Authors: Robbiano Valentina , Giordano Marina , Martella Christian , Stasio Francesco Di , Chiappe Daniele , de Mongeot Francesco Buatier , Comoretto Davide
Published: April 2013

The interaction of localized surface plasmon resonances (LSPRs) with the photonic modes in an opal photonic crystal is reported. Gold nanocrescents are evaporated at glancing angles over both microsphere monolayers and artificial opals. Microsphere monolayers allow the three localised plasmonic resonances observed in the nanocrescent optical spectra to be identified. By changing the microsphere diameter, the opal photonic stop band and a selected plasmonic resonance can be spectrally overlapped causing a dramatic change of the properties of both excitations. The creation of new modes is observed, whose spectral position and dispersion properties are a combination of those localised in nanoparticle plasmons and in the photonic crystal.
Use of D‐optimal design to model and the analysis of the effect of the draw ratio on some physical properties of hot multistage drawn nylon 6 fibers
Authors: Rahbar Ruhollah Semnani , Haji Aminoddin
Published: April 2013

In this article, we present an experimental design methodology for studying the effect of the draw ratio on the physical properties of nylon 6 fibers on hot multistage drawing. A response surface methodology involving D‐optimal design was used for the modeling and optimization. According to the analysis of variance results, the proposed models could be used to navigate the design space. We found that the responses of the tenacity and initial modulus were very sensitive to the factor of the second‐stage draw ratio, and the shrinkage response was governed by the factor of the third‐stage draw ratio. The results show a good agreement between the experimental and model predictions with high correlation coefficients. The operation conditions for obtaining the drawn yarn with the highest tenacity and initial modulus and low shrinkage are proposed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1337‐1344, 2013
Characterization and dual functionalization of polystyrene with propionic anhydride and cyanate derivatives
Authors: Gunes Hasan Huseyin , Okudan Ahmet
Published: April 2013

First, Friedel–Crafts reactions were used for the acylation process. For this, polystyrene (PS) was reacted with propionic anhydride in the presence of Lewis acid catalyst. The amount of acyl group linked PS as a result of acylation has been identified as volumetric. Second, the bromination and lithiation reactions of acylated PS containing carbonyl groups were realized. Also, the lithiated PS containing acyl groups has been modified a second time with various isocyanates and isothiocyanate derivatives in the presence of n‒BuLi catalyst. Some important reaction parameters were assigned in order to optimize the process. The structure all of the products were characterized by Fourier transform infrared, 1H NMR (Proton Nuclear Magnetic Resonance), and thermogravimetric methods. In addition, reaction yields were determined according to the result of elemental analysis. Dual functionalization yields were realized between 62.2% and 69.9%. For kinetic analysis, the TG/DTG (Thermal Gravimetric Analysis/Differantial Thermal Analysis) data obtained at three different heating rates were processed by Kissinger–Akahira–Sunose method. The results demonstrated that the acylation reaction, bromination and lithiation reactions, and dual functionalization reactions with cyanate derivatives can be carried out to obtain a significantly functionalized polymer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1351‐1362, 2013
Mechanical and dielectric properties of short‐carbon‐fibers/epoxy‐modified‐organic‐silicone‐resin as heat resistant microwave absorbing coatings
Authors: Huang Shanshan , Zhou Wancheng , Luo Fa , Zhu Dongmei
Published: April 2013

Heat resistant microwave absorbing coatings were prepared by brushing and thereafter heat treatment, using epoxy modified organic silicone resin as binding material, short carbon fibers (Csf) as absorbers, talcum powder and glass powder as filling materials. The mechanical and dielectric properties of the coatings before and after heat treatment at 600°C for 10 mins were studied. The results showed that the adhesive power after heat treatment enhances remarkably, both the real (ε′) and imaginary (ε″) parts of the permittivity of the coatings increase with increasing Csf content in the frequency range of 8.2–12.4 GHz. The calculation value of the reflection loss as single layer absorber indicates that epoxy modified organic silicone resin coatings containing short carbon fibers could be a promising radar absorbing material applied at high temperature. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1392‐1398, 2013
Effect of 1,3,5‐trialkyl‐benzenetricarboxylamide on the crystallization of poly(lactic acid)
Authors: Wang Ting , Yang Yong , Zhang Chuanzhi , Tang Zhaobin , Na Haining , Zhu Jin
Published: April 2013

A series of 1,3,5‐trialkyl‐benzenetricarboxylamides (BTA‐Rs) with different side‐chain lengths of n‐alkyl are synthesized to use as nucleating agents of poly (lactic acid) (PLA). Crystallization rate of PLA is detailed discussed in nonisothermal melt‐crystallization with addition of the synthesized nucleating agents. Among these BTA‐Rs, BTA‐n‐butyl (BTA‐nBu) shows the most excellent nucleation ability for PLA. The influences of BTA‐nBu on the nonisothermal melt‐crystallization and cold‐crystallization from the glassy state, isothermal crystallization, crystalline structure, and spherulite morphology of PLA are investigated. It is found that 0.8 wt % is the optimal weight fraction of BTA‐nBu to improve the crystallization of PLA. In the case of isothermal melt‐crystallization from melt, the addition of BTA‐nBu shortens the crystallization half‐time and speeds up the crystallization rate of PLA with no discernible effect on the crystalline structure. Besides, BTA‐nBu nucleated PLA exhibits smaller spherulites size and larger nucleation density than that of pure PLA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1328‐1336, 2013
Systematic investigation on parameters of solution blown micro/nanofibers using response surface methodology based on box‐Behnken design
Authors: Lou Huiqing , Li Wentao , Li Chulin , Wang Xinhou
Published: April 2013

Response surface methodology, based on the four‐factor, three‐level Box‐Behnken design, has been utilized to facilitate a more systematic understanding of the solution and processing parameters of solution blown polyethylene oxide (PEO) micro/nanofibers. The factors investigated include air pressure, solution concentration, nozzle diameter, and injection rate. Fiber diameters, ranging from 137 to 1982 nm, are associated with these variables by applying a response surface model. The linear coefficients of air pressure and solution concentration, the interactive effect between air pressure and injection rate as well as the quadratic terms of nozzle diameter and injection rate are demonstrated statistically significant. Verification of the response surface model is successfully accomplished. Consequently, this study puts forward an overview of the effect of solution and technical parameters on solution blown submicron PEO fibers and provides a train of thought for fabricating other micro/nanofibers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1383‐1391, 2013
On spatial contagion and multivariate GARCH models
Authors: Jaworski Piotr , Pitera Marcin
Published: April 2013

We propose a method for defining and measuring spatial contagion between two financial markets via conditional copulas. Some theoretical results on monotonicity and asymptotic properties of Gaussian copulas with respect to conditioning are presented. Next, we combine the spatial contagion approach with time series models. We investigate which model from a large family of multivariate GARCH is the best tool for modelling spatial contagion. In an empirical study, we show that among models designed for general fit, a two‐step model fitting procedure reduces the ability to describe the contagion effect. This is a feature of copula‐GARCH models. Copyright © 2013 John Wiley & Sons, Ltd.