bluuebunny/crossref_metadata_2025 huggingface dataset:
Forecasting Regional Sugarcane Yield Based on Time Integral and Spatial Aggregation of MODIS NDVI
Authors: Mulianga Betty , Bégué Agnès , Simoes Margareth , Todoroff Pierre
Published: May 2013

This study explored the suitability of the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectrometer (MODIS) obtained for six sugar management zones, over nine years (2002–2010), to forecast sugarcane yield on an annual and zonal base. To take into account the characteristics of the sugarcane crop management (15-month cycle for a ratoon, accompanied with continuous harvest in Western Kenya), the temporal series of NDVI was normalized through an original weighting method that considered the growth period of the sugarcane crop (wNDVI), and correlated it with historical yield datasets. Results when using wNDVI were consistent with historical yield and significant at P-value = 0.001, while results when using traditional annual NDVI integrated over the calendar year were not significant. This correlation between yield and wNDVI is mainly drawn by the spatial dimension of the data set (R2 = 0.53, when all years are aggregated together), rather than by the temporal dimension of the data set (R2 = 0.1, when all zones are aggregated). A test on 2012 yield estimation with this model realized a RMSE less than 5 t·ha−1. Despite progress in the methodology through the weighted NDVI, and an extensive spatio-temporal analysis, this paper shows the difficulty in forecasting sugarcane yield on an annual base using current satellite low-resolution data. This is particularly true in the context of small scale farmers with fields measuring less than the size of MODIS 250 m pixel, and in the context of a 15-month crop cycle with no seasonal cropping calendar. Future satellite missions should permit monitoring of sugarcane yields using image resolutions that facilitate extraction of crop phenology from a group of individual plots.
A Passive Wireless Multi-Sensor SAW Technology Device and System Perspectives
Authors: Malocha Donald , Gallagher Mark , Fisher Brian , Humphries James , Gallagher Daniel , Kozlovski Nikolai
Published: May 2013

This paper will discuss a SAW passive, wireless multi-sensor system under development by our group for the past several years. The device focus is on orthogonal frequency coded (OFC) SAW sensors, which use both frequency diversity and pulse position reflectors to encode the device ID and will be briefly contrasted to other embodiments. A synchronous correlator transceiver is used for the hardware and post processing and correlation techniques of the received signal to extract the sensor information will be presented. Critical device and system parameters addressed include encoding, operational range, SAW device parameters, post-processing, and antenna-SAW device integration. A fully developed 915 MHz OFC SAW multi-sensor system is used to show experimental results. The system is based on a software radio approach that provides great flexibility for future enhancements and diverse sensor applications. Several different sensor types using the OFC SAW platform are shown.
A Self-Sensing Piezoelectric MicroCantilever Biosensor for Detection of Ultrasmall Adsorbed Masses: Theory and Experiments
Authors: Faegh Samira , Jalili Nader , Sridhar Srinivas
Published: May 2013

Detection of ultrasmall masses such as proteins and pathogens has been made possible as a result of advancements in nanotechnology. Development of label-free and highly sensitive biosensors has enabled the transduction of molecular recognition into detectable physical quantities. Microcantilever (MC)-based systems have played a widespread role in developing such biosensors. One of the most important drawbacks of all of the available biosensors is that they all come at a very high cost. Moreover, there are certain limitations in the measurement equipments attached to the biosensors which are mostly optical measurement systems. A unique self-sensing detection technique is proposed in this paper in order to address most of the limitations of the current measurement systems. A self-sensing bridge is used to excite piezoelectric MC-based sensor functioning in dynamic mode, which simultaneously measures the system’s response through the self-induced voltage generated in the piezoelectric material. As a result, the need for bulky, expensive read-out equipment is eliminated. A comprehensive mathematical model is presented for the proposed self-sensing detection platform using distributed-parameters system modeling. An adaptation strategy is then implemented in the second part in order to compensate for the time-variation of piezoelectric properties which dynamically improves the behavior of the system. Finally, results are reported from an extensive experimental investigation carried out to prove the capability of the proposed platform. Experimental results verified the proposed mathematical modeling presented in the first part of the study with accuracy of 97.48%. Implementing the adaptation strategy increased the accuracy to 99.82%. These results proved the measurement capability of the proposed self-sensing strategy. It enables development of a cost-effective, sensitive and miniaturized mass sensing platform.
Hydrothermal Synthesis of Various Hierarchical ZnO Nanostructures and Their Methane Sensing Properties
Authors: Zhou Qu , Chen Weigen , Xu Lingna , Peng Shudi
Published: May 2013

Hierarchical flower-like ZnO nanorods, net-like ZnO nanofibers and ZnO nanobulks have been successfully synthesized via a surfactant assisted hydrothemal method. The synthesized products were characterized by X-ray powder diffraction and field emission scanning electron microscopy, respectively. A possible growth mechanism of the various hierarchical ZnO nanostructures is discussed in detail. Gas sensors based on the as-prepared ZnO nanostructures were fabricated by screen-printing on a flat ceramic substrate. Furthermore, their gas sensing characteristics towards methane were systematically investigated. Methane is an important characteristic hydrocarbon contaminant found dissolved in power transformer oil as a result of faults. We find that the hierarchical flower-like ZnO nanorods and net-like ZnO nanofibers samples show higher gas response and lower operating temperature with rapid response-recovery time compared to those of sensors based on ZnO nanobulks. These results present a feasible way of exploring high performance sensing materials for on-site detection of characteristic fault gases dissolved in transformer oil.
BiP Negatively Affects Ricin Transport
Authors: Gregers Tone , Skånland Sigrid , Wälchli Sébastien , Bakke Oddmund , Sandvig Kirsten
Published: May 2013

The AB plant toxin ricin binds both glycoproteins and glycolipids at the cell surface via its B subunit. After binding, ricin is endocytosed and then transported retrogradely through the Golgi to the endoplasmic reticulum (ER). In the ER, the A subunit is retrotranslocated to the cytosol in a chaperone-dependent process, which is not fully explored. Recently two separate siRNA screens have demonstrated that ER chaperones have implications for ricin toxicity. ER associated degradation (ERAD) involves translocation of misfolded proteins from ER to cytosol and it is conceivable that protein toxins exploit this pathway. The ER chaperone BiP is an important ER regulator and has been implicated in toxicity mediated by cholera and Shiga toxin. In this study, we have investigated the role of BiP in ricin translocation to the cytosol. We first show that overexpression of BiP inhibited ricin translocation and protected cells against the toxin. Furthermore, shRNA-mediated depletion of BiP enhanced toxin translocation resulting in increased cytotoxicity. BiP-dependent inhibition of ricin toxicity was independent of ER stress. Our findings suggest that in contrast to what was shown with the Shiga toxin, the presence of BiP does not facilitate, but rather inhibits the entry of ricin into the cytosol.
Rire pour se protéger du monde
Authors: Charrin Ève
Published: May 2013

L’ironie est devenue, dans nos démocraties occidentales, une habitude de pensée qui permet de prendre ses distances vis-à-vis d’une réalité navrante tout en gardant bonne conscience. Mais il n’en va pas de même partout, tout le temps ; il existe un cycle de l’ironie. En France sous la monarchie de Juillet, en Tunisie sous Ben Ali, elle est efficace. Peut-on retrouver cette ironie des commencements ?
Termes éponymes en médecine et application pédagogique
Authors: Monin Sylvie
Published: May 2013

Cet article sur les termes éponymes anglais ou français en médecine montre que cette sorte de dénomination n’est pas seulement caractérisée par certaines de ses difficultés sémantiques, mais aussi par les limites de la notion de termes éponymes, les traits dénotatifs et connotatifs de certains termes éponymes (en particulier, des connotations nationales, religieuses et culturelles). Il souligne la fréquence basse des termes éponymes employés par la communauté de spécialistes concernée. Il insiste aussi sur les traits historiques et humains de ces termes. Enfin, il présente dix exercices à partir de termes éponymes en médecine qui sont toujours absents, à notre connaissance, dans les manuels disponibles.
Cohérences plurielles
Authors: Sabiron Jean
Published: May 2013

Par une combinatoire d’outils langagiers adaptés aux goûts et besoins des étudiants de sciences, élaborés régulièrement sous le nom d’ACADEME, on parvient à faire de l’enseignement de l’anglais à ces « non-spécialistes » l’instrument d’une vraie progression intellectuelle et humaine.
L’autonomie des enseignants de langue de spécialité : un gage d’innovation raisonnée
Authors: Haramboure Françoise
Published: May 2013

En raison de la diversité des publics auxquels ils s’adressent, de la spécificité des contextes dans lesquels ils interviennent, les enseignants en langue de spécialité ont dû s’affranchir des méthodes standardisées et universalistes qui leur étaient proposées. Ils ont été amenés à innover, à concevoir de nouvelles démarches d’enseignement et à créer leur propre dispositif d’apprentissage. Ce faisant, ils ont entrepris, sous l’impulsion de groupes de recherche tels que le GERAS et l’APLIUT, des travaux de recherche-action qui reflètent bien tout le bénéfice que les étudiants peuvent tirer de l’autonomie de leurs enseignants.
LC/LCS : une langue paranoïaque?
Authors: Décuré Nicole
Published: May 2013

Une langue étrangère est considérée comme un outil pour communiquer le plus largement possible avec le maximum de gens les plus divers. Mais on oublie qu’une langue étrangère sert aussi à ériger une barrière entre soi et les autres, que c’est un moyen de couper la communication. Cette recherche est le résultat d’une enquête menée auprès de personnes qui ont employé et emploient une langue étrangère afin de n’être comprises que d’un ou quelques individus. Ceci nous amène à nous interroger sur la notion de communication, sur la motivation pour apprendre une langue étrangère et sur Internet comme nouvel outil de recherche.
Speaking skills in scientific English: Intelligibility, redundancy and compensation strategies
Authors: Upjohn Jonathan , Amadis Diana , Fries-Verdeil Marie-Hélène
Published: May 2013

Speaking Skills for Scientific English est le troisième volet dans la série Minimum Competence in Scientific English(MCSE). Il a été conçu pour aider ceux qui doivent présenter leurs recherches en anglais lors des colloques à améliorer leurs communications. La prononciation, malheureusement, par manque de temps, est souvent négligée dans l’enseignement des langues. Par conséquent, l’intelligibilité ne va pas de soi. Après une esquisse de l’historique de la série MCSE, nous analysons un court extrait d’une séquence vidéo d’une jeune doctorante. Ensuite, nous abordons une discussion des notions d’intelligibilité, de redondance et des stratégies de compensation dans une défense raisonnée de notre démarche.
Total Parenteral Nutrition–Associated Lamina Propria Inflammation in Mice Is Mediated by a MyD88-Dependent Mechanism
Authors: Miyasaka Eiichi A. , Feng Yongjia , Poroyko Valeriy , Falkowski Nicole R. , Erb-Downward John , Gillilland Merritt G. , Mason Katie L. , Huffnagle Gary B. , Teitelbaum Daniel H.
Published: May 2013

Enteral nutrient deprivation via total parenteral nutrition (TPN) administration leads to local mucosal inflammatory responses, but the underlying mechanisms are unknown. Wild-type (WT) and MyD88−/− mice underwent jugular vein cannulation. One group received TPN without chow, and controls received standard chow. After 7 d, we harvested intestinal mucosally associated bacteria and isolated small-bowel lamina propria (LP) cells. Bacterial populations were analyzed using 454 pyrosequencing. LP cells were analyzed using quantitative PCR and multicolor flow cytometry. WT, control mucosally associated microbiota were Firmicutes-dominant, whereas WT TPN mice were Proteobacteria-domiant. Similar changes were observed in MyD88−/− mice with TPN administration. UniFrac analysis showed divergent small bowel and colonic bacterial communities in controls, merging toward similar microbiota (but distinct from controls) with TPN. The percentage of LP T regulatory cells significantly decreased with TPN in WT mice. F4/80+CD11b+CD11cdull/− macrophage–derived proinflammatory cytokines significantly increased with TPN. These proinflammatory immunologic changes were significantly abrogated in MyD88−/− TPN mice. Thus, TPN administration is associated with significant expansion of Proteobacteria within the intestinal microbiota and increased proinflammatory LP cytokines. Additionally, MyD88 signaling blockade abrogated decline in epithelial cell proliferation and epithelial barrier function loss.
The relationship between technology acceptance and frequency of mobile commerce use amongst Generation Y consumers
Authors: Dlodlo Nobukhosi , Mafini Chengedzai
Published: May 2013

Orientation: The South African mobile commerce industry has realised an exponential growth in the past few years, yet the Generation Y market segment has failed to keep pace with this growth.Research purpose: To examine the nature of the relationships that exist between technology acceptance and frequency of mobile commerce usage amongst Generation Y consumers.Motivation for the study: The Generation Y cohort has emerged as an important age-group due to its economic contribution to the economy. It is therefore essential that their attitudes and behaviour continue to receive empirical introspection, particularly since mobile commerce has gathered momentum as an important and arguably, the most popular medium for commercial transactions. In a global space that is technology based, it becomes imperative to investigate the interplay between mobile commerce acceptance dimensions and frequency of use amongst Generation Ys.Research design, approach and method: A survey was conducted with the aid of a structured self-administered questionnaire with a view to collecting primary data from a sample consisting of 204 Generation Y consumers.Main findings: There were positive correlations between frequency of use and five mobile commerce acceptance dimensions. Cronbach Alpha values ranged between 0.714 and 0.898, thereby indicating high internal consistency amongst the subscales as well as within the entire survey instrument. Correlation coefficients ranged between 0.164 and 0.677 at both the p < 0.01 and p < 0.05 significance levels (2-tailed test), indicating very high levels of association amongst the subscales. Predictive validity of the five subscales and the variable frequency of use resulted in positive and statistically-significant results that were established at an adjusted R2 value of 0.674.Practical/managerial implications: Marketers and business practitioners are presented with practical insights into dimensions that enhance frequency of use of mobile commerce technology amongst Generation Y consumers. Furthermore, an increased usage of mobile commerce technologies is projected to have a stimulus effect on profitability, sustainability and loyalty of this important market segment.Contribution/value-add: Frequency of use is a good predictor of Generation Y consumers’ acceptance of mobile commerce as justified by the positive and statistically significant results of this study.
The Impact of Perceptions of Training on Employee Commitment and Turnover Intention: Evidence from Pakistan
Authors: Ashar Muhammad , Ghafoor Mudasar , Munir Easha , Hafeez Sadia
Published: May 2013

To survive in highly competitive business environment organizations are focusing on capitalizing its human recourses. These resources are very difficult to imitate and combination with other resources also help to gain edge over competitors. The objective of our study is to investigate relationship of two most important perceptions of training with affective commitment. These perceptions of training include perceived availability of training and perceived supervisor support for training. Later on we investigate relationship of affective commitment with employee turnover intentions. For this purpose questionnaire were considered as a tool to get responses from telecom and banking sector of Pakistan. Total 150 questionnaires were distributed and 123 useful questionnaires were received at a response rate of 82%. Statistical tools that used to analyze the relationships were Pearson moment quotient and linear regression. The result shows significant positive association of both training perceptions with affective commitment. The finding also shows significant negative association of affective commitment with employee turnover intention. This study helps managers to understand training-attitude-organizational performance relationship. Key Words: Training Perceptions, Affective Commitment, Turnover Intention, HR Practices
Effects of Staff Turnover on the Employee Performance of Work at Masinde Muliro University of Science and Technology
Authors: Butali Namasaka David , Wesang’ula Poipoi Moses , Mamuli Laura Catherine
Published: May 2013

High staff turnover affects the smooth running of institutions. This study established the effect of staff turnover on performance of work in Masinde Muliro University of Science and Technology (MMUST). Specific objectives of the study were: to identify effects of staff turnover on administrative work and to identify financial/economic effects of staff turnover. A conceptual framework formed the basis of this study. Correlational research design was used in this study. Cluster random sampling procedure was used to collect data. Questionnaires, interviews, document analysis and observation were blended to capture authentic and exhaustive data. A randomly selected sample of 25 departments was used in this study. A total of 152 respondents participated. Data were analyzed using inferential and descriptive statistics.. The study established that economically, staff turnover in increases work for the remaining staff, leads to customer dissatisfaction, brings about decreased income due to reduced productivity, and leads to increased liability to the practice. Socially, staff turnover lowers staff morale and creates gaps in the social groupings. The study recommends that MMUST should improve on mechanisms of getting feedback from its staff members regarding problems that are likely to cause staff turnover. In addition, staff taking over duties performed by those exiting be given proper orientation.Key Words; Non teaching departments, Non teaching staff, Performance of Work,                Retention rate, Staff turnover and Teaching departments.
Results of Cataract Surgery with Z-flex Hydrophilic Acrylic Toric IOL
Authors: Einan-Lifshitz Adi , Barkana Yaniv , Goldich Yakov , Gutfreund Shay , Avni Isaac , Zadok David
Published: May 2013

Purpose

To report the outcome of cataract surgery with implantation of the Z-flex 690TA hydrophilic acrylic toric intraocular lens (IOL).

Methods

We enrolled consecutive patients who had 1.75 D or more of preexisting corneal astigmatism. Patients had cataract extraction surgery with implantation of a Z-flex 690TA toric IOL (Medicontur, Hungary). Refractive outcomes, keratometry, correction ratio (CR), and error of magnitude (EM) were evaluated.

Results

Nineteen eyes of 13 patients were evaluated. Mean follow-up time was 4.3 ± 2.3 months. Mean preoperative keratometric astigmatism was 3.05 ± 0.74 D. Mean postoperative deviation from the anticipated spherical equivalent was +0.23 ± 0.39 D, with 100% of eyes achieving a spherical equivalent within ± 1.00 D of the target refraction. Mean deviation from the anticipated refractive cylinder was 0.46 ± 0.47 D. Mean IOL misalignment was 5.67 ± 6.45 degrees. Mean CR was 1.02 ± 0.22, and the mean EM was −0.09 ± 0.55 D.

Conclusion

The Z-flex 690TA hydrophilic acrylic toric IOL implantation was safe, effective, and predictable in correcting corneal astigmatism during cataract surgery.
Therapeutic Strategies in Penile Cancer: State of the Art
Authors: Gulino Gaetano , Palermo Giuseppe , Recupero Salvatore Marco , Antonucci Michele , Racioppi Marco , Pinto Francesco , Sacco Emilio , Bassi Pier Francesco
Published: May 2013

A systematic review of the current treatment options and of the outcomes of penile carcinoma has been performed with special focus on controversial issues. A MedLine search using specified search terms was done during the period 1988 - January 2013.

Demolitive surgery is considered as the “gold standard” treatment of invasive penile carcinoma staged higher than T2, but negative psychological outcomes were reported. On the other hand, conservative surgical techniques have been associated with higher recurrence rates. Potency-sparing technique (glansectomy and apexes sparing) preserves penile length: the reconstruction of glans anatomy and function is a key point to restore anatomy and sexual functions. Techniques such as glanduloplasty have given satisfactory anatomic, functional and sexual outcomes.

Lymphadenectomy is indicated in any case of inguinal palpable nodes that persist after a course of antibiotic therapy, but also in all the cases staged T2 or higher, or in any high-grade penile cancer. It is still being debated the extension of inguinal lymphadenectomy for penile cancer: unilateral, bilateral, and extended to pelvic lymph nodes. Due to the specific radioresistance of penile cancer, radiation therapy is currently indicated in case of unresectable penile cancers with palliative intent. Chemotherapy is indicated as adjuvant therapy for stage T1-T3, N1-3, M0, or as neo-adjuvant therapy in the event of extensive pelvic and inguinal lymphadenopathies, or as palliative treatment in patients with unresectable or metastatic cancers. New chemotherapy agents such as Cis - platinum and Taxanes have shown promising results in early trials.
Expressive Bodies / Controlling Impulses The Dance Between Official Culture and Musical Resistance in Colonial Western Tanganyika
Authors: Gunderson Frank
Published: May 2013

This article will demonstrate, via a series of seven music-related vignettes gathered from archival research and oral history, aspects of the historical relationship between resistance expressed via “musicking,” and “official culture” expressed via the use of force, spectacle, policy, and the rule of law. The relationship between power and musical resistance is treated as a dance: one partner in this dance is the “controlling mechanism” inherent and always implied in the expression of power and the entire spectrum of behavior that power encompasses. The other partner is the spectrum of resistive musical responses that includes everything from blatant protest via public performative “spectacle,” “hidden resistance,” accommodative resistance, and subtle and blatant complicity. The majority of the historical vignettes come from the Sukuma region of western Tanzania, taking place during the German and British colonial periods (from the late 1900s up to the early 1960s).
James Baldwin, Simone de Beauvoir, and the “New Vocabulary” of Existentialist Ethics
Authors: Farneth Frank
Published: May 2013

James Baldwin wrote that his essay “Everybody's Protest Novel” marked “a beginning of my finding a new vocabulary and another point of view.” This article explores the striking similarities between the new ethical vocabulary in Baldwin's early Paris essays and that of Simone de Beauvoir's emerging existentialist ethics, particularly in their use of a coming-of-age metaphor to talk in moral terms about innocence, guilt, and responsibility. Reading these two authors together illuminates both Beauvoir's unique characterization of existentialism and its influence on Baldwin's mature thought.
Metodología para cálculo de seeing en el Observatorio Astronómico Centroamericano de Suyapa, Tegucigalpa, Honduras
Authors: Schöngarth Roberto
Published: May 2013

El presente trabajo propone una metodología a ser utilizada para la caracterización de las condiciones de observación en el Observatorio Astronómico Centroamericano de Suyapa OACS, particularmente en lo relacionado a la medición del seeing. Se utiliza el análisis de imágenes píxel por píxel tratando de estimar el seeing a través del FWHM, utilizando como límite superior el píxel de máxima intensidad de cada una de las imágenes de la estrella Zeta Geminorum que sirvió para hacer el estudio, y cuyo límite inferior es el promedio de intensidad del cielo de fondo. Para lograr mayor precisión en la estimación se promediaron los valores estimados de un grupo de 10 imágenes y a partir de ahí inferir un intervalo de confianza del 95% para la estimación del seeing el cual para el presente trabajó resulto ser de 5.2332-5.8448 segundos de arco el cual es un valor de seeing relativamente alto (condiciones regulares de observación) respecto a los 2 ó a lo sumo 3 segundos de arco recomendados para observaciones con un buen cielo.DOI: http://dx.doi.org/10.5377/ce.v1i1.609 Ciencias Espaciales 1(1) 2009
La promoción de la investigación científica a través de la capacitación metodológica y técnica
Authors: Salomón Leticia , Medina Edwin , Amador Jorge
Published: May 2013

DOI: http://dx.doi.org/10.5377/rct.v0i10.1059 Revista Ciencia y Tecnología, No. 10, junio 2012 pp.3-14
Viaje al corazón de Taulabé
Authors: Urbizo Vivas César Mauricio , Durán Leiva Patrick , Huertas Giovanni Peraldo , Ramírez Salazar Ronald
Published: May 2013

El presente trabajo es el resultado de una excursión en la que participaron académicos de la Universidad Nacional Autónoma de Honduras (UNAH), de la Universidad de Costa Rica (UCR) y del Grupo Espeleológico Anthros. Se realizó una visita exploratoria al interior de las Cuevas de Taulabé para obtener evidencia científica que explique el origen y composición de dichas cavernas, con el fin de fortalecer los vínculos académicos interuniversitarios y con grupos especializados en espeleología con lo que se logre proyectar investigación que aumente el conocimiento científico sobre esas cavernas y de sustento a mejor información para el sector turismo. Por medio de observaciones y pruebas cualitativas se concluye que las cuevas han sido formadas en un complicado sistema hidrogeológico que afecta formaciones de rocas calizas, en donde el principal mineral formador de la morfología kárstica observada es calcita. El artículo es propositivo en la medida de que ahonda en las recomendaciones sobre las investigaciones científicas que puedan realizarse para profundizar más en el conocimiento de dichas cavernas. DOI: http://dx.doi.org/10.5377/rct.v0i10.1062 Revista Ciencia y Tecnología, No. 10, junio 2012 pp 57-68
Deficiencia de hierro y su relación con la función cognitiva en escolares
Authors: Rivera Ivette C , Félix Rivera María , Rivera Rebeca
Published: May 2013

Objetivo: En Honduras no se cuenta con estudios de deficiencia de hierro y cognición, por lo que se decidió realizar un estudio con el objetivo de determinar la relación entre la deficiencia de hierro y la capacidad cognitiva en escolares de primer grado de escuelas públicas de Tegucigalpa MDC. Sujetos y materiales: el estudio es caso control. Se realizo inicialmente un estudio de prevalencia de anemia por deficiencia de hierro y al mismo tiempo un estudio sobre deficiencia de hierro en escuelas públicas de Tegucigalpa en niños de primer grado en el año 2010, de donde se seleccionaron los niños para el presente estudio. Los niños seleccionados se distribuyeron en dos grupos, aparejados de acuerdo a edad y sexo y el nivel socioeconómico, y todos tenían niveles de folatos y cobalamina normales conformados así: Grupo 1: niños con niveles de hemoglobina mayor de 11.4 gr/dl, con ferritina menor de 15 ìg/l, definidos como “niños casos”. Grupo 2: niños con niveles de hemoglobina mayores de 11.4 gr/dl y ferritina normal, considerados como “niños controles”. Para la determinación de la deficiencia de hierro en los niños, se utilizó ferritina. Se les realizaron pruebas psicológicas para determinar la capacidad cognitiva; se evaluó el coeficiente intelectual, atención, memoria y aprendizaje, madurez como ser Raven, Tomal, Bender, D2-Brickenkamp. A los padres de los escolares se les solicitó consentimiento informado y firmado. Se aplicó estadística descriptiva y, para detectar diferencias significativas entre los dos grupos del estudio, la prueba diferencias de promedios (t de Student) con un valor de p significativo menor a 0,05. Resultados: la media de edad en el grupo de los niños casos fue de 6.49 años (0.74 1DE) y en los niños casos de 6.27 años (0.45 1DE) las diferencias no fueron estadísticamente significativas (p=0.26). Se encontró que fue menor el puntaje en aprendizaje y memoria en niños con ferritina baja que los que tenían ferritina normal, ambos grupos sin anemia, y las diferencias fueron estadísticamente significativas (p=0.02) y no en los puntajes de atención ya que no se encontraron diferencias significativas (p=0.81) entre los grupos. Conclusiones: como hemos visto, la mayoría de los estudios realizados en escolares con deficiencia de hierro coincide en vislumbrar un deterioro de dicha capacidad haciendo evidente que los escolares con déficit de hierro sin anemia tendrán problemas en el aprendizaje y por ende va a repercutir en el aprovechamiento escolar, por lo que se deben de tomar medidas necesarias y urgentes para la solución de este problema totalmente prevenible. DOI: http://dx.doi.org/10.5377/rct.v0i10.1063 Revista Ciencia y Tecnología, No. 10, junio 2012 pp 69-80
Determinación de residuos de líquidos inflamables en escombros de incendios por cromatografía de gases-FID
Authors: Ponce Rodríguez Henry Daniel
Published: May 2013

Se presenta un método para determinar trazas de líquidos inflamables en escombros de incendios, tales como gasolina, diesel y otros compuestos acelerantes, por medio de cromatografía de gases con detector de ionización de flama (FID), capaz de separar e identificar en cantidades de partes por millón con buena resolución y exactitud. Se prepararon muestras control para corroborar el proceso de extracción por medio de la técnica de adsorción pasiva con tiras de carbón activado y su posterior desorción con disulfuro de carbono (CS2), utilizando una columna capilar de 30 metros DB-1, con una corrida cromatográfica de 31 minutos. Se obtuvo una correcta separación capaz de diferenciar entre compuestos más volátiles de aquellos con elevado punto de ebullición. Se presentan los cromatogramas obtenidos de los controles blanco, acelerantes y disulfuro; todos preparados asemejando las posibles matrices a estudiar en un posible incendio, tales como restos de papel, ropa, algodón, entre otros más. DOI: http://dx.doi.org/10.5377/rct.v0i10.1064 Revista Ciencia y Tecnología, No. 10, junio 2012 pp 81-
Los Premios a la Investigación Científica de la UNAH: Un instrumento de estímulo y promoción de la actividad investigativa
Authors: Caballero Zeitún Elsa Lily
Published: May 2013

DOI: http://dx.doi.org/10.5377/rct.v0i11.1069 Revista Ciencia y Tecnología, No. 11, diciembre 2012 pp 3-10
Un intento de considerar la escorrentía muy rápida (emr) en la modelación hidrológica
Authors: Ávalos Lingán Roberto Fredy
Published: May 2013

En el Manual de Referencias Hidrológicas para el Diseño de Obras de Drenaje Menor se presenta información valiosa de intensidades máximas de lluvia para todo el territorio hondureño y de pruebas de infiltraciones realizadas en diferentes tipos de suelos, donde para el caso de las intensidades de 5 minutos, el 77% de las estaciones sobrepasan fácilmente los 100 mm/h (intensidades fuertes) y el 60% de la pruebas de infiltración muestran una infiltración inicial que exceden los 100 mm/h. La disponibilidad de esta información y, sobre todo sus magnitudes, nos ha permitido hacer realidad la idea de hace varios años de intentar hacer uso de dicha información para ser incluida en un modelo hidrológico y representar la Escorrentía Muy Rápida (EMR); es decir, cuando la intensidad de lluvia es mayor que la capacidad de infiltración del suelo. Como primer ensayo se introdujo en un modelo hidrológico conceptual una simple función lineal para representar la EMR, dependiendo ésta de las intensidades máximas de lluvia de 5 min, de la capacidad máxima de infiltración en 5 min y de la lluvia en mm/día, observándose que a una misma lluvia el aumento de la EMR depende del aumento del parámetro de escurrimiento muy rápido (CMR), parámetro que gobierna la función. DOI: http://dx.doi.org/10.5377/rct.v0i11.1074 Revista Ciencia y Tecnología, No. 11, diciembre 2012 pp 61-69
Exploiting Loops in the Camera Array for Automatic Focusing Depth Estimation
Authors: Yang Tao , Zhang Yanning , Yu Rui , Chen Ting
Published: May 2013

Abstract Autofocus is a fundamental and key problem for modern imaging sensor design. Although this problem has been well studied in single camera literature, unfortunately, little research has been done on large-scale camera arrays. Most of the existing synthetic aperture imaging systems still need to manually select the optimal focus plane when an object moves. Unlike the conventional autofocus method, which sweeps the focus plane to find the maximal contrast, we present a novel optimization framework to handle the above challenges. In particular, we formulate the camera array autofocus problem as a constrained optimization problem by minimizing the temporal and spatial correspondences error subject to global loop constraint. Then this problem is relaxed as a quadratic program and solved using sequential quadratic programming. The experimental results show that the proposed method achieves a better performance compared with the results of traditional methods. To the best of our knowledge, our proposed method is the first optimization framework for solving camera array autofocus problem and it is of great importance to improve the performance of the existing synthetic aperture imaging system.
Synopsis of the Woody Species of Smilax in the Eastern United States North of Peninsular Florida
Authors: Bullard A. J. , Allen Charles M.
Published: May 2013

The nine woody species of Smilax (S. auriculata, S. bona-nox, S. glauca, S. laurifolia, S. pumila, S. rotundifolia, S. smallii, S. tamnoides, and S. walteri) of the eastern United States north of peninsular Florida are described through the use of charts. The habitat, range, common names, and synonyms for each are listed. A key to the nine species is provided.
Four Crayfishes (Decapoda: Cambaridae) New to the North Carolina Fauna, With Notes on Other Species in the State
Authors: Cooper John E. , Russ William T.
Published: May 2013

Cambarus (Puncticambarus) aldermanorum, originally considered endemic to South Carolina, is now known from the upper Catawba River basin in Burke and Caldwell counties, North Carolina. Orconectes (Crockerinus) erichsonianus and Orconectes (Procericambarus) forceps, both previously known from Alabama, Georgia, Tennessee and Virginia, are apparently now expanding their ranges from Tennessee into the French Broad River basin in Madison County, North Carolina. Cambarus (Cambarus) eeseeohensis, an endemic species once considered limited in distribution to the Linville River in Avery County, is reported from the Watauga River basin in Watauga County and the Johns River subdrainage of the Catawba River basin in Avery County. Voucher specimens for new localities for an undescribed endemic species, Orconectes (Procericambarus) sp. (the “Cheoah” crayfish), and two invasive species, Orconectes (Gremicambarus) virilis and Orconectes (Procericambarus) rusticus, are provided. A single specimen of a non-native species, Procambarus (Pennides) spiculifer, is reported from a tributary of the Watauga River in Watauga County. Some life history and taxonomic notes for several of the species are included.
AIDSClinical Trials Group (ACTG)
Authors: Andersen Janet W.
Published: May 2013

The AIDS Clinical Trials Group (ACTG) is the largest Network conducting therapeutic clinical trials in AIDS and HIV, with active clinical sites in the United States, South America, Haiti, Africa, India, and Thailand. The ultimate goal of the ACTG is to identify drugs and other treatment modalities that will result in the successful control of HIV in infected persons.
Turbine Engine Component Integration
Authors: Sforza Pasquale M.
Published: May 2013

A fundamental analysis of the matching of the rotating components of a gas turbine engine and their integration into an airframe is presented. Similarity variables are introduced to characterize the operation of the rotating engine components. Performance maps of compressors and turbines are used to illustrate the manner in which they may be matched in terms of power, mass flow, and shaft speed. Because one engine may be used in several different aircraft it must be properly integrated in each. The specific case of matching inlet performance and engine airflow requirements is discussed. An analysis of thrust generation in an aircraft is performed to identify those parameters necessary for monitoring and controlling the thrust in flight. An illustration of the importance of proper positioning of the terminal shock in supersonic inlets and means for controlling that position is presented.
Patient‐Reported Outcomes and the Association With Clinical Response in Patients With Active Psoriatic Arthritis Treated With Golimumab: Findings Through 2 Years of a Phase III, Multicenter, Randomized, Double‐Blind, Placebo‐Controlled Trial
Authors: Kavanaugh Arthur , McInnes Iain B. , Krueger Gerald G. , Gladman Dafna , Beutler Anna , Gathany Tim , Mack Michael , Tandon Neeta , Han Chenglong , Mease Philip
Published: May 2013

Objective

To evaluate the effect of golimumab on physical function, health‐related quality of life (HRQOL), and productivity in psoriatic arthritis (PsA).

Methods

GO‐REVEAL was a multicenter, randomized, placebo‐controlled study. Adult patients with active PsA (n = 405) received golimumab (50 or 100 mg) or placebo every 4 weeks, with early escape at week 16 (placebo → 50 mg, 50 → 100 mg) or placebo crossover to golimumab 50 mg at week 24. Patient‐reported outcomes included physical function (Health Assessment Questionnaire [HAQ] disability index [DI] score), HRQOL (36‐item Short Form health survey [SF‐36] mental component summary [MCS] and physical component summary [PCS] scores), and productivity (home/school/work). Clinical response was assessed using the 28‐joint Disease Activity Score using the C‐reactive protein level (DAS28‐CRP) and the Psoriasis Area and Severity Index (PASI) score for arthritis and skin symptoms, respectively.

Results

At week 24, golimumab‐treated patients had significant mean improvements in HAQ DI (0.36), SF‐36 (PCS 7.83, MCS 3.84), and productivity (2.24) scores compared with placebo (−0.01, 0.67, −0.60, and 0.08, respectively; P < 0.001 for all). Also, greater proportions of golimumab‐ than placebo‐treated patients had clinically meaningful improvements in HAQ DI (≥0.30) and SF‐36 PCS and MCS (≥5) scores at week 24 (P < 0.05). Also at week 24, improvements in DAS28‐CRP scores were significantly but moderately correlated with improvements in HAQ DI, SF‐36 PCS, and productivity scores. Correlations between these patient‐reported outcomes and improvements in PASI, enthesitis, and dactylitis scores were very weak. Improvements in HAQ DI, SF‐36, and productivity scores were similar among all groups by week 52 and week 104 when including placebo → golimumab crossover patients.

Conclusion

Golimumab‐treated patients had significant improvements in physical function, HRQOL, and productivity through week 24; these improvements correlated with clinical improvement in signs and symptoms of peripheral arthritis and were sustained through 2 years.
Persistently exciting model predictive control
Authors: Marafioti Giancarlo , Bitmead Robert R. , Hovd Morten
Published: May 2013

Model predictive control (MPC) is a well‐known and widely used advanced control technique, which is model‐based and capable of handling both input and state/output constraints via receding horizon optimization methods. Fundamentally, MPC is a nondynamic or memoryless state feedback control. Because of its use of a model, MPC should be amenable to adaptive implementation and to on‐line tuning of the model. Such an approach requires guaranteeing signal properties, known as ‘persistent excitation’, to ensure uniform identifiability of the model, often expressed in terms of spectral content or ‘sufficient richness’ of a periodic input. We propose an approach to augment the input constraint set of MPC to provide this guarantee. This, in turn, requires equipping the controller with its own state to capture the control signal history. The feasibility of periodic signals for this condition is established. A computational example is presented illustrating the technique and its properties. Copyright © 2013 John Wiley & Sons, Ltd.
Single‐Walled Carbon Nanotube/Phase Change Material Composites: Sunlight‐Driven, Reversible, Form‐Stable Phase Transitions for Solar Thermal Energy Storage
Authors: Wang Yunming , Tang Bingtao , Zhang Shufen
Published: May 2013

The development of solar energy conversion materials is critical to the growth of a sustainable energy infrastructure in the coming years. A novel hybrid material based on single‐walled carbon nanotubes (SWNTs) and form‐stable polymer phase change materials (PCMs) is reported. The obtained materials have UV‐vis sunlight harvesting, light‐thermal conversion, thermal energy storage, and form‐stable effects. Judicious application of this efficient photothermal conversion to SWNTs has opened up a rich field of energy materials based on novel SWNT/PCM composits with enhanced performance in energy conversion and storage.
LMNA‐associated cardiocutaneous progeria: An inherited autosomal dominant premature aging syndrome with late onset
Authors: Kane Megan S. , Lindsay Mark E. , Judge Daniel P. , Barrowman Jemima , Ap Rhys Colette , Simonson Lisa , Dietz Harry C. , Michaelis Susan
Published: May 2013

Hutchinson–Gilford Progeria Syndrome (HGPS) is a premature aging disorder caused by mutations in LMNA, which encodes the nuclear scaffold proteins lamin A and C. In HGPS and related progerias, processing of prelamin A is blocked at a critical step mediated by the zinc metalloprotease ZMPSTE24. LMNA‐linked progerias can be grouped into two classes: (1) the processing‐deficient, early onset “typical” progerias (e.g., HGPS), and (2) the processing‐proficient “atypical” progeria syndromes (APS) that are later in onset. Here we describe a previously unrecognized progeria syndrome with prominent cutaneous and cardiovascular manifestations belonging to the second class. We suggest the name LMNA‐associated cardiocutaneous progeria syndrome (LCPS) for this disorder. Affected patients are normal at birth but undergo progressive cutaneous changes in childhood and die in middle age of cardiovascular complications, including accelerated atherosclerosis, calcific valve disease, and cardiomyopathy. In addition, the proband demonstrated cancer susceptibility, a phenotype rarely described for LMNA‐based progeria disorders. The LMNA mutation that caused LCPS in this family is a heterozygous c.899A>G (p.D300G) mutation predicted to alter the coiled–coil domain of lamin A/C. In skin fibroblasts isolated from the proband, the processing and levels of lamin A and C are normal. However, nuclear morphology is aberrant and rescued by treatment with farnesyltransferase inhibitors, as is also the case for HGPS and other laminopathies. Our findings advance knowledge of human LMNA progeria syndromes, and raise the possibility that typical and atypical progerias may converge upon a common mechanism to cause premature aging disease. © 2013 Wiley Periodicals, Inc.
Steady state ensembles of thermal radiation in a layered media with a constant heat flux
Authors: Budaev Bair V. , Bogy David B.
Published: May 2013

This paper describes steady‐state ensembles of thermally excited electromagnetic radiation in nano‐scale layered media with a constant non‐vanishing heat flux across the layers. It is shown that Planck's law of thermal radiation, the principle of equivalence, and the laws of wave propagation in layered media, imply that in order for the ensemble of thermally excited electromagnetic fields to exist in a medium consisting of a stack of layers between two half‐space, the net heat flux across the layers must exceed a certain threshold that is determined by the temperatures of the half spaces and by the reflective properties of the entire structure. The obtained results provide a way for estimating the radiative heat transfer coefficient of nano‐scale layered structures.
Water, salt water, and alkaline solution uptake in epoxy thin films
Authors: Scott P. , Lees J. M.
Published: May 2013

As a means of characterizing the diffusion parameters of fiber reinforced polymer (FRP) composites within a relatively short time frame, the potential use of short term tests on epoxy films to predict the long‐term behavior is investigated. Reference is made to the literature to assess the effectiveness of Fickian and anomalous diffusion models to describe solution uptake in epoxies. The influence of differing exposure conditions on the diffusion in epoxies, in particular the effect of solution type and temperature, are explored. Experimental results, where the solution uptake in desiccated (D) or undesiccated (U) thin films of a commercially available epoxy matrix subjected to water (W), salt water (SW), or alkali concrete pore solution (CPS) at either 20 or 60°C, are also presented. It was found that the type of solution did not significantly influence the diffusion behavior at 20°C and that the mass uptake profile was anomalous. Exposure to 60°C accelerated the initial diffusion behavior and appeared to raise the level of saturation. In spite of the accelerated approach, conclusive values of uptake at saturation remained elusive even at an exposure period of 5 years. This finding questions the viability of using short‐term thin film results to predict the long‐term mechanical performance of FRP materials. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1898–1908, 2013
Microwave absorption enhancement of Fe3O4/polyaniline core/shell hybrid microspheres with controlled shell thickness
Authors: Zhang Bin , Du Yunchen , Zhang Peng , Zhao Hongtao , Kang Leilei , Han Xijiang , Xu Ping
Published: May 2013

Synthesis of Fe3O4/polyaniline (PANI) core/shell hybrid microspheres through an in situ polymerization route with the 300 nm Fe3O4 microspheres as the cores and nucleation sites for PANI is reported. PANI shell thickness, from 30 nm to 120 nm, can be controlled by modulating the weight ratio of aniline monomer and Fe3O4 microspheres. Fe3O4 microspheres that are actually comprised of many small nanoparticles display super paramagnetic feature, which has been maintained in Fe3O4/PANI core/shell hybrid materials. Fe3O4/PANI core/shell hybrid materials have enhanced microwave absorption than both the Fe3O4 microspheres and PANI, where a maximum reflection loss of −37.4 dB at 15.4 GHz has been reached from the sample with a PANI shell thickness of 100 nm. Introduction of dielectric loss, interfacial loss, and improved impedance from coating the Fe3O4 microspheres with PANI should account for the improved microwave absorption properties of the prepared Fe3O4/PANI core/shell hybrid materials. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1909–1916, 2013