bluuebunny/crossref_metadata_2025 huggingface dataset:
Premiers jalons d'une recherche auprès de professionnels soignants
Authors: Delforge François , Périlleux Thomas
Published: September 2012

Résumé À un moment de déclin des programmes institutionnels, les assises symboliques des institutions ont changé de même que leurs modes opératoires ; c’est ce que laisse apparaître une observation de terrain menée par les auteurs dans diverses unités de soins intensifs. Les principes « sacrés » (Dubet) qui fondaient le travail institutionnel sont entrés en crise quand ils ne deviennent pas tout simplement insignifiants pour les individus auxquels ils s’adressent. Ainsi, pour les professionnels rencontrés, le « référentiel chrétien », qui s’efface à leurs yeux des directives officielles, ne fait pas ou plus directement question. S’il reste structurant de certaines pratiques en soins intensifs, c’est de manière souterraine et tacite.
Identités plurielles, intersubjectivité et apprentissage dans les institutions contemporaines
Authors: Cobbaut Jean-Philippe
Published: September 2012

Résumé Les transformations des institutions contemporaines et leurs répercussions sur les sujets qui les composent sont bien présentes dans le champ de l’éthique médicale. Pour mieux cerner les enjeux et afin de dégager certaines pistes pour répondre à la question de l’accompagnement des acteurs du soin dans leurs questionnements, de la possible évolution et transformation des institutions, l’auteur nourrit sa réflexion à partir d’analyses de sociologues, de psychosociologues, de philosophes à propos de l’évolution des institutions, de la pluralisation des acteurs qui les animent et des diverses identités qu’ils mobilisent au sein des institutions. Ce parcours permet de reprendre à nouveaux frais la question de l’accompagnement éthique des professionnels et de montrer l’importance de la notion d’apprentissage collectif, pour affronter la question de la fragmentation vécue au sein de l’éparpillement, subi dans les institutions actuelles.
Ouvertures
Authors: Jacquemin Dominique
Published: September 2012

Résumé À partir d’une proposition de « théologie analogique », l’auteur plaide pour une démarche théologique qui reconnaisse l’humain comme capable de raison, de se questionner, de réfléchir avec d’autres et de se laisser déplacer. Cette démarche le reconnaît de plus comme porteur de capacités à concourir au langage théologique, même sans s’y rapporter dans une posture confessante car, dans la visée de co-construction ici postulée, ne devient-il pas co-créateur et du discours théologique et d’un discours de sens partageable par tous ? Telle serait également la condition pour que la théologie puisse accompagner l’action humaine, pour autant qu’elle en accepte la temporalité avec ce qu’elle implique d’inaccomplissement, tant de l’action que du sens et de sa parole.
Caracterización de fundentes para molde de planchón delgado de acero
Authors: Cruz-Ramírez A. , Vargas-Ramírez M. , Hernández-Pérez M. A. , Palacios-Beas E. , Chávez-Alcalá J. F.
Published: September 2012

Se determinó la composición mineralógica y el comportamiento de fusión-solidificación de dos fundentes comerciales para la colada de planchón delgado de acero. La caracterización de los fundentes comerciales por difracción de rayos X (XRD) y técnicas de microscopía muestra la presencia de wollastonita (CaO - SiO2), un carbonato de sodio (Na2CO3), calcita (CaCO3), fluorita (CaF2) y carbono como los principales componentes. Cuando los fundentes se calentaron a 1.573 K y después de la solidificación, hubo una transformación casi total de los compuestos originales a las fases cuspidina (3CaO - 2SiO2 - CaF2) y nefelina (Na2O - Al2O3 - 2SiO2). El análisis termogravimétrico muestra una importante reducción de peso en los fundentes debido a la descomposición térmica de la calcita y el carbonato de sodio. La caracterización indica que los fundentes son producidos por un proceso de aglomeración.
Aceros ODS FeCrAl avanzados para aplicaciones estructurales de alta temperatura en sistemas de generación de energía
Authors: Pimentel G. , Capdevila C. , Bartolomé M. J. , Chao J. , Serrano M. , García-Junceda A. , Campos M. , Torralba J. M. , Aldazábal J.
Published: September 2012

Las tecnologías y medios para desarrollar plantas de biomasa con alta eficiencia en la conversión de energía son esenciales para asentar la biomasa como una fuente de energía renovable. Los sistemas de turbinas de gas de ciclo combinado (CCGT) permiten elevar la eficiencia de las plantas de biomasa del 35 % actual al 45 %. Sin embargo, para conseguir estos niveles de eficiencia en la conversión de energía, el intercambiador de calor de la caldera debe trabajar en condiciones extremas de temperatura (por encima de 1100 °C) y presión (en torno a 15-30 bar). Los aceros ODS ferríticos son la clase de material avanzado específicamente diseñado para trabajar en ambientes altamente corrosivos y a temperaturas elevadas. Pero para mejorar la resistencia a la fluencia a altas temperaturas en dirección circunferencial, la microestructura generada en el proceso de recristalización ha de ser diferente a la microestructura axi-simétrica altamente anisótropa que tiene este tipo de aceros por defecto. En este sentido, este trabajo detalla los resultados obtenidos en la aleación reforzada por dispersión de óxidos PM 2000 que ha sido fabricada por técnicas pulvimetalúrgicas, consolidada por extrusión y conformada por laminación en caliente y en frio. De los resultados obtenidos puede concluirse que una microestructura heterogénea estimula su recristalización, de forma que grandes gradientes de deformación generan microestructuras más finas e isótropas. La comparación de estos resultados con simulaciones por elementos finitos ha permitido dilucidar el papel que tienen las tensiones residuales subyacentes en la microestructura en la generación de la microestructura recristalizada.
Influencia del contenido de silicio y el tratamiento térmico en la resistencia al desgaste de fundiciones blancas al cromo en condiciones de rápida solidificación
Authors: Goyos L. , Varela A. , Verhaege M. , García A. , Mier J. , Moors M.
Published: September 2012

Se estudia la influencia del silicio y el tratamiento térmico sobre la microestructura y la resistencia al desgaste abrasivo y por fricción seca de una fundición con 3 % C y 12 % Cr, obtenida en condiciones de rápida solidificación. La rápida solidificación disminuye el volumen de carburos, la finura y dispersión de éstos aumentan con el incremento del silicio. Todas las muestras presentaron matrices perlíticas, variando en finura con el tratamiento. No se apreciaron productos de transformación intermedios. Las durezas tuvieron poca variación. Los tratamientos de austenización mostraron poca efectividad, con tendencia a desgastes más elevados que en estado bruto de colada y con tratamiento de mantenimiento. Los comportamientos ante la abrasión y la fricción seca en las condiciones ensayadas fueron similares. Se evidenció alta influencia de la morfología de los carburos en el desgaste abrasivo.
From Swarm Art Toward Ecosystem Art
Authors: Bornhofen Stefan , Gardeux Vincent , Machizaud Andréa
Published: September 2012

Swarm intelligence deals with the study of collectively intelligent behavior that emerges from a decentralized system of non-intelligent individual agents. The concept is widely used in the fields of simulation, optimization or robotics, but less known in the domain of generative art. This paper presents the swarm paradigm in the context of artistic creation, and more particularly explores the interest of enhancing swarm models with dynamics inspired from natural ecosystems. The authors introduce an energy budget to the agents of a swarm system, and show how mapping the energy level to visual information such as line width or color, combined with mechanisms such as resource chasing and consumption, enriches the search space of possible images. Moreover, the authors highlight that the approach allows the user to partially control the creation process of the drawings. The authors argue that the exploration of ecosystem dynamics in generative systems may open up novel artistic opportunities and shift the perspective from swarm art toward ecosystem art.
A Robust Scheme for Aggregating Quasi-Blind Robots in an Active Environment
Authors: Fatès Nazim , Vlassopoulos Nikolaos
Published: September 2012

The question of how to aggregate autonomous agents with limited abilities in the absence of centralized coordination is known as the Decentralized Gathering Problem. The authors present a bio-inspired aggregation scheme that solves this problem and study a first application of this scheme to a small team of robots. The robots (Alice and Khepera III) obey simple rules and have only a rudimentary perception of their environment. The collective behavior is based on stigmergic principles and uses an active environment to relay the communications between robots. This results in an aggregation process that shows good properties of robustness and that can in principle be extended to swarms of robots.
Control of Allergen-Induced Inflammation and Hyperresponsiveness by the Metalloproteinase ADAMTS-12
Authors: Paulissen Geneviève , El Hour Mehdi , Rocks Natacha , Guéders Maud M. , Bureau Fabrice , Foidart Jean-Michel , Lopez-Otin Carlos , Noel Agnès , Cataldo Didier D.
Published: September 2012

A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) constitute a family of endopeptidases related to matrix metalloproteinases. These proteinases have been largely implicated in tissue remodeling associated with pathological processes. Among them, ADAMTS12 was identified as an asthma-associated gene in a human genome screening program. However, its functional implication in asthma is not yet documented. The present study aims at investigating potential ADAMTS-12 functions in experimental models of allergic airways disease. Two different in vivo protocols of allergen-induced airways disease were applied to the recently generated Adamts12-deficient mice and corresponding wild-type mice. In this study, we provide evidence for a protective effect of ADAMTS-12 against bronchial inflammation and hyperresponsiveness. In the absence of Adamts12, challenge with different allergens (OVA and house dust mite) led to exacerbated eosinophilic inflammation in the bronchoalveolar lavage fluid and in lung tissue, along with airway dysfunction assessed by increased airway responsiveness following methacholine exposure. Furthermore, mast cell counts and ST2 receptor and IL-33 levels were higher in the lungs of allergen-challenged Adamts12-deficient mice. The present study provides, to our knowledge, the first experimental evidence for a contribution of ADAMTS-12 as a key mediator in airways disease, interfering with immunological processes leading to inflammation and airway hyperresponsiveness.
HLA-DM Constrains Epitope Selection in the Human CD4 T Cell Response to Vaccinia Virus by Favoring the Presentation of Peptides with Longer HLA-DM–Mediated Half-Lives
Authors: Yin Liusong , Calvo-Calle J. Mauricio , Dominguez-Amorocho Omar , Stern Lawrence J.
Published: September 2012

HLA-DM (DM) is a nonclassical MHC class II (MHC II) protein that acts as a peptide editor to mediate the exchange of peptides loaded onto MHC II during Ag presentation. Although the ability of DM to promote peptide exchange in vitro and in vivo is well established, the role of DM in epitope selection is still unclear, especially in human response to infectious disease. In this study, we addressed this question in the context of the human CD4 T cell response to vaccinia virus. We measured the IC50, intrinsic dissociation t1/2, and DM-mediated dissociation t1/2 for a large set of peptides derived from the major core protein A10L and other known vaccinia epitopes bound to HLA-DR1 and compared these properties to the presence and magnitude of peptide-specific CD4+ T cell responses. We found that MHC II–peptide complex kinetic stability in the presence of DM distinguishes T cell epitopes from nonrecognized peptides in A10L peptides and also in a set of predicted tight binders from the entire vaccinia genome. Taken together, these analyses demonstrate that DM-mediated dissociation t1/2 is a strong and independent factor governing peptide immunogenicity by favoring the presentation of peptides with greater kinetic stability in the presence of DM.
CD31 Exhibits Multiple Roles in Regulating T Lymphocyte Trafficking In Vivo
Authors: Ma Liang , Cheung Kenneth C. P. , Kishore Madhav , Nourshargh Sussan , Mauro Claudio , Marelli-Berg Federica M.
Published: September 2012

The role of CD31, an Ig-like molecule expressed by leukocytes and endothelial cells (ECs), in the regulation of T lymphocyte trafficking remains contentious. Using CD31-deficient mice, we show that CD31 regulates both constitutive and inflammation-induced T cell migration in vivo. Specifically, T cell:EC interactions mediated by CD31 molecules are required for efficient localization of naive T lymphocytes to secondary lymphoid tissue and constitutive recirculation of primed T cells to nonlymphoid tissues. In inflammatory conditions, T cell:EC CD31-mediated interactions facilitate T cell recruitment to Ag-rich sites. However, endothelial CD31 also provides a gate-keeping mechanism to limit the rate of Ag-driven T cell extravasation. This event contributes to the formation of Ag-specific effector T cell infiltrates and is induced by recognition of Ag on the endothelium. In this context, CD31 engagement is required for restoring endothelial continuity, which is temporarily lost upon MHC molecule ligation by migrating cognate T cells. We propose that integrated adhesive and signaling functions of CD31 molecules exert a complex regulation of T cell trafficking, a process that is differentially adapted depending on cell-specific expression, the presence of inflammatory conditions and the molecular mechanism facilitating T cell extravasation.
Preliminary evaluation of selected minerals in liver samples from springbok (Antidorcas marsupialis) from the National Zoological Gardens of South Africa
Authors: Mbatha Khanyisile R. , Lane Emily P. , Lander Michael , Tordiffe Adrian S.W. , Corr Sandra
Published: September 2012

Limited information is available on the mineral nutrition of captive antelope in South Africa. Zoo animals are usually offered a very limited array of feeds, which may result in nutritional imbalances. As a pilot study to investigate the presence of myopathy in antelope at the National Zoological Gardens of South Africa (NZG), stored liver samples from six springbok (Antidorcas marsupialis) and seven other antelopes from the NZG, as well as selected food items, were submitted for analysis of selenium, copper, manganese and zinc content by spectrophotometry. Springbok liver levels of copper were 23.07 mg/kg ± 0.72 mg/kg, whilst manganese, selenium and zinc levels were 6.73 mg/kg ± 0.22 mg/kg, 0.14 mg/kg ± 0.05 mg/kg and 135.02 mg/kg ± 1.26 mg/kg, respectively. Liver mineral levels in the other species were very variable. Food item copper levels ranged from 4.00 mg/kg (Eragrostis tef) to 17.38 mg/kg (antelope cubes), lucerne (Medicago sativa) and E. tef contained no detectable selenium. The highest zinc levels were in antelope cubes (147.00 mg/kg) and the lowest were in lucerne (20.80 mg/kg). Interpretation of these results was hampered by the small number of samples and a paucity of information on liver mineral levels in free-ranging and captive antelope; however, results suggested that, in the springbok, whilst copper and manganese intake are likely adequate, selenium nutrition is probably insufficient and may account for the myopathy diagnosed. Zinc liver levels are possibly within the toxic range, perhaps as a result of the high levels of zinc in the antelope cubes. This pilot study highlighted the need to establish baseline mineral nutrition data for captive and freeranging antelope under South African conditions.
On Hilbert Covariants
Authors: Abdesselam Abdelmalek , Chipalkatti Jaydeep
Published: September 2012

Let F denote a binary form of order d over the complex numbers. If r is a divisor of d, then the Hilbert covariant Hr,d(F) vanishes exactly when F is the perfect power of an order r form. In geometric terms, the coefficients of H give defining equations for the image variety X of an embedding Pr ↪ Pd. In this paper we describe a new construction of the Hilbert covariant and simultaneously situate it into a wider class of covariants called the Göttingen covariants, all of which vanish on X. We prove that the ideal generated by the coefficients of H defines X as a scheme. Finally, we exhibit a generalisation of the Göttingen covariants to n-ary forms using the classical Clebsch transfer principle.
From Quantum Groups to Groups
Authors: Kalantar Mehrdad , Neufang Matthias
Published: September 2012

In this paper we use the recent developments in the representation theory of locally compact quantum groups, to assign to each locally compact quantum group 𝔾 a locally compact group 𝔾˜ that is the quantum version of point-masses and is an invariant for the latter. We show that “quantum point-masses” can be identified with several other locally compact groups that can be naturally assigned to the quantum group 𝔾. This assignment preserves compactness as well as discreteness (hence also finiteness), and for large classes of quantum groups, amenability. We calculate this invariant for some of the most well-known examples of non-classical quantum groups. Also, we show that several structural properties of 𝔾 are encoded by 𝔾˜; the latter, despite being a simpler object, can carry very important information about 𝔾.
Prevalence and Risk Factor associated with Musculoskeletal Pain among Students of MGM Dental College: A Cross- Sectional Survey
Authors: Madaan Vishwas , Chaudhari Amit
Published: September 2012

Background

The aim of this study was to determine the prevalence and associated risk factors for development of musculoskeletal pain among the dental students of 3rd, 4th year and interns, at MGM Dental College, Navi Mumbai.

Materials and Methods

A valid and reliable close ended questionnaire was administered to 230 students of 3rd year, 4th year and interns who met the inclusion criteria. A response rate of 77% was achieved. The variables included in the questionnaire were (1) presence of pain, (2) awareness regarding correct posture, (3) areas of the body affected by pain, (4) clinical setting, (5) practices to reduce pain. Statistical analysis was applied using Chi-square test.

Results

In this study, we found a total of 81% prevalence of musculoskeletal pain among the dental students. Eighty-one percent were unaware of the correct posture for dental clinical procedures.

Statistical significance was observed between different clinical activities and musculoskeletal pain when Chi-square test was applied. Maximum pain was observed in the hand (92%) followed by wrist (85%) and lower back (72%). Sixty-three percent of the students having pain performed cervical flexions and torsions to improve vision of the oral cavity. Seventy-five percent of the students reported that they were uncomfortable with their current working stool. Five percent of the participants performed exercises after clinical practice of which none reported musculoskeletal pain.

Conclusion

Dental students are prone to development of musculoskeletal pain due to lack of awareness regarding correct posture, prolonged static postures, inadequate operating stools and lack of exercises.

How to cite this article

Madaan V, Chaudhari A. Prevalence and Risk Factor associated with Musculoskeletal Pain among Students of MGM Dental College: A Cross-Sectional Survey. J Contemp Dent 2012;2(2):22-27.
Stress and the Periodontium
Authors: Sharma Nisha , Gujjari Sheela Kumar , Kanagotagi Sachin
Published: September 2012

Stress or tension is an unavoidable part of human life. It has been proven to cause not only health-related problems but problems pertaining to periodontium too. These include periodontal pocket formation, apical migration of junctional epithelium and delated wound healing. This paper connects the link between stress, its effect on general health and consequently on oral health.

How to cite this article

Sharma N, Gujjari SK, Kanagotagi S. Stress and the Periodontium. J Contemp Dent 2012;2(2):28-30.
Orthokeratinized Odontogenic Cyst
Authors: Swain Niharika , Poonja LS , Dekate Kamlesh
Published: September 2012

Orthokeratinized odontogenic cyst (OOC) is a developmental cyst of odontogenic origin and was initially defined as the uncommon orthokeratinized variant of odontogenic keratocyst (OKC). However, recently World Health Organization has designated OOC as a distinct clinicopathologic entity as it has peculiar clinicopathologic aspects when compared to other developmental odontogenic cysts, especially OKCs. The orthokeratinized odontogenic cyst is histologically characterized by a thin, uniform, epithelial lining with orthokeratinization and a subjacent prominent granular cell layer. The purpose of the article is to present a case of OOC arising in the anterior mandible, an unusual site for the lesion and also highlights the importance of distinguishing it from the more commonly occurring keratocystic odontogenic tumor (KCOT).

How to cite this article

Swain N, Patel S, Poonja LS, Pathak J, Dekate K. Orthokeratinized Odontogenic Cyst. J Contemp Dent 2012;2(2):31-33.
Foreign Object Lodgment in the Root Canal and Its Management: A Case Report and an Overview
Authors: Grover Charu , Thomas Manuel S , Pai AR Vivekananda
Published: September 2012

Self-introduced foreign object by an adult into the root canal of a lower incisor is seldom reported in the endodontic literature. This case report describes a self-introduced unusual foreign body and its retrieval from the root canal of lower left lateral incisor. A persistent sinus tract resistant to calcium hydroxide intracanal medicament was then successfully treated with the use of triple antibiotic paste. Postendodontically, nonvital bleaching and composite resin restoration was used to restore the form, function and esthetics of the tooth in a conservative manner.

How to cite this article

Grover C, Thomas MS, Pai ARV. Foreign Object Lodgment in the Root Canal and Its Management: A Case Report and an Overview. J Contemp Dent 2012;2(2):47-52.
Characterization of submicron particles influenced by mixed biogenic and anthropogenic emissions using high-resolution aerosol mass spectrometry: results from CARES
Authors: Setyan A. , Zhang Q. , Merkel M. , Knighton W. B. , Sun Y. , Song C. , Shilling J. E. , Onasch T. B. , Herndon S. C. , Worsnop D. R. , Fast J. D. , Zaveri R. A. , Berg L. K. , Wiedensohler A. , Flowers B. A. , Dubey M. K. , Subramanian R.
Published: September 2012

Abstract. An Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed during the Carbonaceous Aerosols and Radiative Effects Study (CARES) that took place in northern California in June 2010. We present results obtained at Cool (denoted as the T1 site of the project) in the foothills of the Sierra Nevada Mountains, where intense biogenic emissions are periodically mixed with urban outflow transported by daytime southwesterly winds from the Sacramento metropolitan area. During this study, the average mass loading of submicrometer particles (PM1) was 3.0 μg m−3, dominated by organics (80%) and sulfate (9.9%). The organic aerosol (OA) had a nominal formula of C1H1.38N0.004OM0.44, thus an average organic mass-to-carbon (OM/OC) ratio of 1.70. Two distinct oxygenated OA factors were identified via Positive matrix factorization (PMF) of the high-resolution mass spectra of organics. The more oxidized MO-OOA (O/C = 0.54) was interpreted as a surrogate for secondary OA (SOA) influenced by biogenic emissions whereas the less oxidized LO-OOA (O/C = 0.42) was found to represent SOA formed in photochemically processed urban emissions. LO-OOA correlated strongly with ozone and MO-OOA correlated well with two 1st generation isoprene oxidation products (methacrolein and methyl vinyl ketone), indicating that both SOAs were relatively fresh. A hydrocarbon like OA (HOA) factor was also identified, representing primary emissions mainly due to local traffic. On average, SOA (= MO-OOA + LO-OOA) accounted for 91% of the total OA mass and 72% of the PM1 mass observed at Cool. Twenty three periods of urban plumes from T0 (Sacramento) to T1 (Cool) were identified using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). The average PM1 mass loading was considerably higher in urban plumes than in air masses dominated by biogenic SOA. The change in OA mass relative to CO (ΔOA/ΔCO) varied in the range of 5-196 μg m−3 ppm−1, reflecting large variability in SOA production. The highest ΔOA/ΔCO was reached when air masses were dominated by anthropogenic emissions in the presence of a high concentration of biogenic volatile organic compounds (BVOCs). This ratio, which was 97 μg m−3 ppm−1 on average, was much higher than when urban plumes arrived in a low BVOC environment (~36 μg m−3 ppm−1) or during other periods dominated by biogenic SOA (35 μg m−3 ppm−1). These results demonstrate that SOA formation is enhanced when anthropogenic emissions interact with biogenic precursors.
Interactive ozone and methane chemistry in GISS-E2 historical and future climate simulations
Authors: Shindell D. T. , Pechony O. , Voulgarakis A. , Faluvegi G. , Nazarenko L. , Lamarque J.-F. , Bowman K. , Milly G. , Kovari B. , Ruedy R. , Schmidt G.
Published: September 2012

Abstract. The new generation GISS climate model includes fully interactive chemistry related to ozone in historical and future simulations, and interactive methane in future simulations. Evaluation of ozone, its tropospheric precursors, and methane shows that the model captures much of the large-scale spatial structure seen in recent observations. While the model is much improved compared with the previous chemistry-climate model, especially for ozone seasonality in the stratosphere, there is still slightly too rapid stratospheric circulation too little stratosphere-to-troposphere ozone flux in the Southern Hemisphere and an Antarctic ozone hole that is too large and persists too long quantitative metrics of spatial and temporal correlations with satellite datasets as well as spatial autocorrelation to examine transport and mixing are presented to document improvements in model skill and provide a benchmark for future evaluations. The difference in radiative forcing (RF) calculated using modeled tropospheric ozone versus tropospheric ozone observed by TES is only 0.016 W m−2. Historical 20th Century simulations show a steady increase in whole atmosphere ozone RF through 1970 after which there is a decrease through 2000 due to stratospheric ozone depletion. Ozone forcing increases in the future under RCP8.5 owing to a projected recovery of stratospheric ozone depletion and increases in methane, but decreases under other RCPs due to reductions in emissions of other ozone precursors. RF from methane is 0.05 to 0.18 W m−2 higher in our model calculations than in the RCP RF estimates. The surface temperature response to ozone through 1970 follows the increase in forcing due to tropospheric ozone. After that time, surface temperatures decrease as ozone RF declines due to stratospheric depletion. The stratospheric ozone depletion also induces substantial changes in surface winds and the Southern Ocean circulation, which may play a role in a slightly stronger response per unit forcing during later decades. Tropical precipitation shifts south during boreal summer from 1850 to 1970, but then shifts northward from 1970 to 2000, following upper tropospheric temperature gradients more strongly than those at the surface.
Observational constraints on ozone radiative forcing from the Atmospheric Chemistry Climate Model Intercomparison Project (ACCMIP)
Authors: Bowman K. , Shindell D. , Worden H. , Lamarque J. F. , Young P. J. , Stevenson D. , Qu Z. , de la Torre M. , Bergmann D. , Cameron-Smith P. , Collins W. J. , Doherty R. , Dalsøren S. , Faluvegi G. , Folberth G. , Horowitz L. W. , Josse B. , Lee Y. H. , MacKenzie I. , Myhre G. , Nagashima T. , Naik V. , Plummer D. , Rumbold S. , Skeie R. , Strode S. , Sudo K. , Szopa S. , Voulgarakis A. , Zeng G. , Kulawik S. , Worden J.
Published: September 2012

Abstract. We use simultaneous observations of ozone and outgoing longwave radiation (OLR) from the Tropospheric Emission Spectrometer (TES) to evaluate ozone distributions and radiative forcing simulated by a suite of chemistry-climate models that participated in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). The ensemble mean of ACCMIP models show a persistent but modest tropospheric ozone low bias (5–20 ppb) in the Southern Hemisphere (SH) and modest high bias (5–10 ppb) in the Northern Hemisphere (NH) relative to TES for 2005–2010. These biases lead to substantial differences in ozone instantaneous radiative forcing between TES and the ACCMIP simulations. Using TES instantaneous radiative kernels (IRK), we show that the ACCMIP ensemble mean has a low bias in the SH tropics of up to 100 m W m−2 locally and a global low bias of 35 ± 44 m W m−2 relative to TES. Combining ACCMIP preindustrial ozone and the TES present-day ozone, we calculate an observationally constrained estimate of tropospheric ozone radiative forcing (RF) of 399 ± 70 m W m−2, which is about 7% higher than using the ACCMIP models alone but with the same standard deviation (Stevenson et al., 2012). In addition, we explore an alternate approach to constraining radiative forcing estimates by choosing a subset of models that best match TES ozone, which leads to an ozone RF of 369 ± 42 m W m−2. This estimate is closer to the ACCMIP ensemble mean RF but about a 40% reduction in standard deviation. These results point towards a profitable direction of combining observations and chemistry-climate model simulations to reduce uncertainty in ozone radiative forcing.
High latitude cooling associated with landscape changes from North American boreal forest fires
Authors: Rogers B. M. , Randerson J. T. , Bonan G. B.
Published: September 2012

Abstract. Fires in the boreal forests of North America are generally stand-replacing, killing the majority of trees and initiating succession that may last over a century. Functional variation during succession can affect local surface energy budgets and, potentially, regional climate. Burn area across Alaska and Canada has increased in the last few decades and is projected to be substantially higher by the end of the 21st century because of a warmer climate with longer growing seasons. Here we simulated the changes in forest composition due to altered burn area using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from remote sensing. When coupled to an Earth system model, younger vegetation from increased burning cooled the high-latitude atmosphere, primarily in the winter and spring, with noticeable feedbacks from the ocean and sea ice. Results from multiple scenarios suggest that a doubling of burn area would result in surface cooling of 0.23 ± 0.09 °C and 0.43 ± 0.12 °C for winter–spring and February–April time periods, respectively. This could provide a negative feedback to high-latitude terrestrial warming during winter on the order of 4–6% for a doubling, and 14–23% for a quadrupling, of burn area. Further work is needed to integrate all the climate drivers from boreal forest fires, including aerosols and greenhouse gasses.
Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles
Authors: Haverd V. , Raupach M. R. , Briggs P. R. , Canadell J. G. , Isaac P. , Pickett-Heaps C. , Roxburgh S. H. , van Gorsel E. , Viscarra Rossel R. A. , Wang Z.
Published: September 2012

Abstract. Information about the carbon cycle potentially constrains the water cycle, and vice versa. This paper explores the utility of multiple observation sets to constrain a land surface model of Australian terrestrial carbon and water cycles, and the resulting mean carbon pools and fluxes, as well as their temporal and spatial variability. Observations include streamflow from 416 gauged catchments, measurements of evapotranspiration (ET) and net ecosystem production (NEP) from 12 eddy-flux sites, litterfall data, and data on carbon pools. By projecting residuals between observations and corresponding predictions onto uncertainty in model predictions at the continental scale, we find that eddy flux measurements provide a significantly tighter constraint on continental net primary production (NPP) than the other data types. Nonetheless, simultaneous constraint by multiple data types is important for mitigating bias from any single type. Four significant results emerging from the multiply-constrained model are that, for the 1990–2011 period: (i) on the Australian continent, a predominantly semi-arid region, over half the water loss through ET (0.64 ± 0.05) occurs through soil evaporation and bypasses plants entirely; (ii) mean Australian NPP is quantified at 2.2 ± 0.4 (1σ) Pg C yr−1; (iii) annually cyclic ("grassy") vegetation and persistent ("woody") vegetation account for 0.56 ± 0.14 and 0.43 ± 0.14, respectively of NPP across Australia; (iv) the average interannual variability of Australia's NEP (±0.18 Pg C yr−1, 1σ) is larger than Australia's total anthropogenic greenhouse gas emissions in 2011 (0.149 Pg C equivalent yr−1), and is dominated by variability in Desert and Savanna regions.
A universal calibration function for determination of soil moisture with cosmic-ray neutrons
Authors: Franz T. E. , Zreda M. , Rosolem R. , Ferre T. P. A.
Published: September 2012

Abstract. A cosmic-ray soil moisture probe is usually calibrated locally using soil samples collected within its support volume. But such calibration may be difficult or impractical, for example when soil contains stones, in presence of bedrock outcrops, in urban environments, or when the probe is used as a rover. Here we use the neutron transport code MCNPx with observed soil chemistries and pore water distribution to derive a universal calibration function to be used in such environments. Comparisons with independent soil moisture measurements at one cosmic-ray probe site and, separately, at thirty-five sites, show that the universal calibration function explains more than 75% of the total variation within each dataset, permitting accurate isolation of the soil moisture signal from the measured neutron signal.
Daily precipitation concentration across Europe 1971–2010
Authors: Cortesi N. , Gonzalez-Hidalgo J. C. , Brunetti M. , Martin-Vide J.
Published: September 2012

Abstract. Daily Precipitation Concentration Index (CI) was used in this paper to investigate the statistical structure of daily precipitation across Europe based on 530 daily rainfall series for the period 1971–2010. Annual CI shows a North-West to South-East gradient (excluding Turkey and Greece). The same gradient is also observed in winter, spring and autumn, while in summer the gradient is North-South. Highest annual and seasonal daily concentrations of rainfall were detected in the western Mediterranean basin, mainly along Spanish and French coastlands. Latitude and distance from the sea seems to play a major role on spatial CI distribution; at subregional scale also relief plays an important role. The Mann–Kendall test did not identify uniform significant pattern in temporal trend across Europe for 1971–2010 period. The only broad areas with increasing annual and seasonal CI values are located in northern and south-western France and northern coastlands of the Iberian Peninsula. This findings suggest that daily precipitation distribution has not significantly changed during the 1971–2010 over Europe.
Ruta de la gestión para la reducción del riesgo de desastres en Honduras
Authors: Elvir Oscar , Kawas Nabil
Published: September 2012

Este trabajo intenta explicar los inicios y estado actual de la Gestión del Riesgo (GR) en Honduras, con el propósito de tener una visión de su evolución y el fortalecimiento de acciones que contribuyan a la reducción de impactos de los desastres. El método de investigación consistió en el uso de entrevistas a coordinadores de proyectos en GR, visitas y entrevistas con directores de instituciones gubernamentales e internacionales que trabajan en GRRD, consultas a bibliografía disponible en lo referente a la temática y experiencia de los autores en la elaboración de diferentes trabajos en GRRD. Los resultados obtenidos ayudan a comprender el estado de la GRRD en el país en diferentes áreas de interés como la evolución del marco jurídico de las instituciones que trabajan en el tema, las debilidades y fortalezas, los trabajos de investigación realizados, las amenazas de fenómenos naturales y antropogénicos que han causado mayores daños y pérdidas, el cambio climático, la educación, las zonas más vulnerables ante la ocurrencia de frecuentes amenazas y la preparación del país para hacerle frente a un desastre de grandes proporciones y, para finalizar, se discuten los resultados acerca de las directrices que debería tomar la GRRD en el país.DOI: http://dx.doi.org/10.5377/rct.v0i9.705 Revista Ciencia y Tecnología, No. 9, Diciembre 2011 pp.4-15
Gestión para la reducción del riesgo de desastres en Honduras
Authors: Kawas Nabil
Published: September 2012

CIENCIA Y TECNOLOGÍA (CT) Entrevista al Profesor Nabil Kawas, Coordinador y catedrático de la Maestría en Gestión de Riesgos de la Facultad de Ciencias, actualmente se desempeña como Director del Instituto Hondureño de Ciencias de la Tierra de la UNAH. Ha sido profesor de varios cursos en Hidrometereologia, Gestión de Riesgos y Recursos Hídricos, Representante de Honduras ante la Organización Meteorológica Mundial, 1986- 1994, miembro del Consejo Ejecutivo de la OM, y Secretario Ejecutivo del Comité Regional centroamericano de Recursos Hidráulicos (1977-1986).DOI: http://dx.doi.org/10.5377/rct.v0i9.706 Revista Ciencia y Tecnología, No. 9, Diciembre 2011 pp.19-23
Estudio gravimétrico del cuadrángulo de Tegucigalpa, Valle del Zamorano, Valle de San Juan de Flores y Morocelí
Authors: Moncada Carlos A Tenorio , Canales Elizabeth Espinoza
Published: September 2012

Entre el 4 de julio y el 17 de agosto del 2007, realizó una campaña de gravimetría con el propósito de recolectar datos de gravedad relativa en las regiones del cuadrángulo de Tegucigalpa, Valle del Zamorano y Valle de San Juan de Flores y Morocelí. En dicha campaña se establecieron 67 estaciones, con las cuales se formó una red gravimétrica local con 24 circuitos, interconectados mediante una estación base que forma parte de la red regional establecida por NOA-NGS (2001). A lo largo de toda la zona de influencia encontramos fuertes anomalías negativas de Bouguer, entre -57 y -79 mGals, consistentes con los valores regionales reportados anteriormente por Bowin (1978) y Weyl (1980) asociadas a la compensación isostática en la zona central de Honduras. En los valles de San Juan de Flores (Cantarranas), Morocelí y El Zamorano, definimos niveles de gravedad regional adecuados para explorar la topografía interna del basamento y las profundidades del aluvión a lo largo de perfiles selectos. Utilizando el programa GRAVMAG (Burger et al, 2006) que implementa el método de Talwani et al, (1959) para calcular gravedad residual, construimos modelos del cuerpo de aluvión en dos dimensiones consistentes con la geología y gravedad residual observada, asumiendo un contraste de densidad de -0.4g/cm3. Los fondos más irregulares y profundos se observaron en el valle de Morocelí, para un perfil longitudinal de 37 km en el cual las profundidades oscilan entre 1000, 400 y 1,400 m. Los Valles de San Juan de Flores y Zamorano, por el contrario, exhiben una topografía interna suave y profundidades máximas de 130 y 350 m., respectivamente. Para la zona metropolitana de la ciudad de Tegucigalpa elaboramos un mapa de contorno de anomalías de Bouguer y observamos una fuerte correlación con la geología local, con un máximo alrededor de -60 mgals asociado a la formación Río Chiquito (Krc) del grupo de Valle de Angeles, y valores bajos, hasta -80 mGals, en las zonas de tobas y sedimentos volcánicos del Grupo Padre Miguel. Esto significa que es posible definir curvas de gravedad regional asociada a la zona de contacto entre estos dos grupos, una variable de gran importancia geotécnica para la industria local de la construcción. Nuestra exploración preliminar del campo de gravedad residual en Tegucigalpa sugiere un nivel de gravedad regional de -67 mGals para hacer correcciones de isostasia en futuros trabajos de exploración gravimétrica en esta ciudad. DOI: http://dx.doi.org/10.5377/rct.v0i9.707 Revista Ciencia y Tecnología, No. 9, Diciembre 2011 pp.27-67
El ingreso familiar y el acceso de jóvenes a la educación media en Honduras
Authors: Romero Héctor Díaz
Published: September 2012

El siguiente documento sustenta empíricamente: la influencia que tiene el ingreso económico familiar en las posibilidades de los jóvenes, para ingresar al sistema de educación media en Honduras, partiendo de la hipótesis siguiente: el ingreso económico familiar influye de manera sistemática la participación de los niños y jóvenes en la educación. Esta investigación utiliza un método econométrico de regresión probabilística para testear la hipótesis, el cual se validó con criterios estadísticos de Akaike y Schwarz para modelos anidados, que resultó en un modelo robusto para explicar de manera bastante aceptable la variable. Los datos presentados provienen de la Encuesta para el Mejoramiento de Condiciones de Vida (ENCOVI) que aplicó el Instituto Nacional de Estadísticas (INE) en el Año 2004. El acceso a datos más recientes no fue posible, por lo anterior, es probable que alguna de la problemática planteada ya haya sido resuelta por los programas públicos dedicados a la materia. Este documento demuestra que el ingreso familiar tiene un impacto sistemático sobre el acceso de los jóvenes entre 12 y 18 años al sistema de educación media en Honduras; además, la zona geográfica donde habitan las familias tiene una influencia determinante en tal acceso. Por lo tanto es necesario, establecer políticas públicas encaminadas a solucionar estos problemas. DOI: http://dx.doi.org/10.5377/rct.v0i9.710 Revista Ciencia y Tecnología, No. 9, Diciembre 2011 pp.95-109
Química nuclear: Aplicaciones de salud en Honduras
Authors: Vivas César Mauricio Urbizo
Published: September 2012

La química nuclear es una rama de la ciencia que tiene sus orígenes a finales del siglo XIX y goza de múltiples aplicaciones a nivel mundial. El presente trabajo pretende ilustrar al lector cuáles son los principios básicos que fundamentan las teorías nucleares. Muestra algunas de las aplicaciones de salud más destacadas en Honduras y la legislación vigente que las rige. Se presenta una revisión bibliográfica sobre los últimos avances referidos a las moléculas radioactivas con aplicaciones terapéuticas. DOI: http://dx.doi.org/10.5377/rct.v0i9.712 Revista Ciencia y Tecnología, No. 9, Diciembre 2011 pp.126-138
Entrepreneurial Environment and the Prevalence of Diabetes in U.S. Counities
Authors: Blanchard Troy C. , Li Jing , Mencken Carson , Tolbert Charles M.
Published: September 2012

Objective. To examine whether the presence of an entrepreneurial culture in a community is associated with county-level diabetes prevalence in the U.S. after accounting for high level of spatial clustering of prevalence rates observed in prior research. Methods. We perform a county-level spatial regression analysis of CDC diabetes prevalence rates. We measure entrepreneurial culture as the number of businesses with 0 to 4 employees per 1,000 residents. Results. The level of entrepreneurial culture in a community is associated with lower rates of diabetes. Our findings show that the key measure of entrepreneurial culture has expected effects on county diabetes rates. However, we show that failure to control for spatial error dependence in previous research leads to an overestimation of the effects of entrepreneurial culture on diabetes prevalence. Conclusion. Policies aimed at curbing diabetes prevalence should utilize the business community as a key agent of social change. Researchers should also utilize spatial regression techniques when analyzing county-level diabetes prevalence rates, because of high level of spatial clustering of rates.
Speech Identification with Temporal and Spectral Modification in Subjects with Auditory Neuropathy
Authors: Kumar Name Vijaya , Vanaja C. S.
Published: September 2012

Background. The aim of this study was to investigate the individual effects of envelope enhancement and high-pass filtering (500 Hz) on word identification scores in quiet for individuals with Auditory Neuropathy.
Method. Twelve individuals with Auditory Neuropathy (six males and six females) with ages ranging from 12 to 40 years participated in the study. Word identification was assessed using bi-syllabic words in each of three speech processing conditions: unprocessed, envelope-enhanced, and high-pass filtered. All signal processing was carried out using MATLAB-7.
Results. Word identification scores showed a mean improvement of 18% with envelope enhanced versus unprocessed speech. No significant improvement was observed with high-pass filtered versus unprocessed speech.
Conclusion. These results suggest that the compression/expansion signal processing strategy enhances speech identification scores—at least for mild and moderately impaired individuals with AN. In contrast, simple high-pass filtering (i.e., eliminating the low-frequency content of the signal) does not improve speech perception in quiet for individuals with Auditory Neuropathy.
Optimization of the Synthesis of Nanostructured Tungsten-Molybdenum Bimetallic Oxide
Authors: Hassan H. , Zaki T. , Mikhail S. , Kandil A. , Farag A.
Published: September 2012

nanoparticles were prepared through the Pechini process and were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR spectrometer, and differential thermal analysis (TG-DSC) analyses. The polyesterification reaction, as the starting step, has a profound influence on the dispersion of the resulting nanoparticles. The molar ratios CA : TM = 2 and EG : CA = 1.5 are favorable for the preparation of nanoparticles having average particles size ranging from 2 to 9 nm. Meanwhile, the molar ratios CA : TM = 4 and EG : CA = 0.19 are favorable for the preparation of nanoparticles having an average particles size ranging from 11 to 29 nm. For the calcination step, increased calcination time (eight hours) at 500°C is advantageous for allowing the monometallic phases enough time to transform into the desired bimetallic phase.
Particle Adhesion Measurements on Insect Wing Membranes Using Atomic Force Microscopy
Authors: Watson Gregory S. , Cribb Bronwen W. , Watson Jolanta A.
Published: September 2012

Many insects have evolved refined self-cleaning membrane structuring to contend with an environment that presents a range of potential contaminates. Contamination has the potential to reduce or interfere with the primary functioning of the wing membrane or affect other wing cuticle properties, (for example, antireflection). Insects will typically encounter a variety of air-borne contaminants which include plant matter and soil fragments. Insects with relatively long or large wings may be especially susceptible to fouling due to the high-wing surface area and reduced ability to clean their extremities. In this study we have investigated the adhesion of particles (pollens and hydrophilic silica spheres) to wing membranes of the super/hydrophobic cicada (Thopha sessiliba), butterfly (Eurema hecabe), and the hydrophilic wing of flower wasp (Scolia soror). The adhesional forces with both hydrophobic insects was significantly lower for all particle types than the hydrophilic insect species studied.