bluuebunny/crossref_metadata_2025 huggingface dataset:
Efecto del NaCl y de los termoperiodos sobre la germinación de semillas de Suaeda mexicana (Standl.) Standl. (Chenopodiaceae)
Authors: Sánchez-Tizapantzi Gabriel , Ruiz-Font Angélica
Published: November 2015

En el presente trabajo se investigó el efecto del cloruro de sodio (NaCl) y de los termoperiodos en la germinación de la especie Suaeda mexicana, en tres tipos de semillas: 1) sin testa, 2) con testa café y 3) con testa negra. Las semillas se sometieron a tres diferentes termoperiodos (0 °C/20 °C, 5 °C/25 °C y 10 °C/30 °C) y a siete diferentes concentraciones de NaCl (200, 400, 600, 800, 1000, 1500 y 3000 mM) y como testigo se usó agua destilada (0 mM NaCl) utilizando un fotoperiodo de 12 h oscuridad/12 h luz.

En los resultados, las semillas sin testa presentaron el mayor porcentaje de germinación en todos los termoperiodos en agua destilada. En los termoperiodos de 5 °C/25 °C y 10 °C/30 °C se obtuvo una germinación de alrededor del 97% para los tres tipos de semillas, mientras que en el de 0 °C/20 °C en semillas sin testa se obtuvo el 72%; en las semillas de testa café fue del 7% y en las de testa negra del 1%.

Las concentraciones de NaCl reducen la germinación de las semillas sin testa en promedio un 12% a 1000 mM de NaCl en todos los termoperiodos. En las semillas de testa café la reducción fue del 3% a 600 mM de NaCl en un termoperiodo de 5 °C/25 °C y en las de testa negra no hubo germinación en concentraciones salinas.

En conclusión, la germinación de Suaeda mexicana varía de acuerdo al tipo de semilla, termoperiodo y salinidad expuesta, siendo la semilla sin testa la que mejor responde.
Modelación y simulación de disipadores de calor para procesadores de computadora en COMSOL Multiphysics
Authors: Garro Acón Sulin , Díaz Espinoza Luis Alberto , Liang Jian , Martínez Hernández Fabio , Meneses Fuentes William , Ortega Padilla Huber , Ramírez Chaves Gabriel , Stradi Granados Benito
Published: November 2015

En este estudio se analizó la transferencia de calor en tres disipadores de calor utilizados para enfriar los procesadores de computadoras de escritorio.

El objetivo de estos disipadores es evitar el sobrecalentamiento de la unidad de procesamiento y la consecuente reducción de la vida útil del computador. Los disipadores de calor se modelaron usando COMSOL Multiphysics con las dimensiones reales de los dispositivos y la generación de calor se modeló con una fuente puntual.

Luego se modificaron los diseños de los disipadores para lograr una temperatura más baja en la zona más caliente del procesador. El resultado fue una reducción en la temperatura en el rango de 5-78 grados Kelvin, al rediseñarse el disipador de calor con variaciones feasibles como la reducción del grosor de las placas de intercambio de calor y el aumento de su número.

Esto demuestra la posibilidad de desarrollar diseños optimizados para disipadores de calor que no requieran más materiales sino una mejor ingeniería. El trabajo se inició como parte del curso CM-4101 Modelización y Simulación.
Posibilidades educativas de la wiki
Authors: Mora Vicarioli Francisco
Published: November 2015

El artículo presenta el recurso wiki como una herramientaflexiblequeaportagrandesposibilidades a la educación. Su principal característica es que permite a un conjunto de usuarios interactuar de forma asincrónica para crear algún tipo de contenido y que cada uno puede agregar, quitar o editar los aportes propios o de los demás.
Consideraciones conceptuales para la comprensión de la gestión ambiental en el sector público (Primera parte)
Authors: Johnson Madrigal Helmut
Published: November 2015

A lo largo de la época moderna han surgido diversas percepciones sobre el asunto de la Gestión Ambiental, en respuesta a la visión particular de sus proponentes. La realidad actual exige una nueva percepción más integral y compleja con el objetivo de satisfacer las necesidades sociales, económicas, políticas, culturales y ambientales, todas ellas componentes esenciales para la implementación de un modelo de desarrollo sostenible más ético, moral, justo y equitativo.
Extracción y evaluación de taninos condensados a partir de la corteza de once especies maderables de Costa Rica
Authors: Aguilar López Jorge , Jaén Jiménez Jean Carlo , Vargas Abarca Ana Sofía , Jiménez Bonilla Pablo , Vega Guzmán Ileana , Herrera Núñez Jacqueline , Borbón Alpízar Henry , Soto Fallas Roy Mario
Published: November 2015

La naturaleza química de los taninos condensados los convierte en una fuente natural de compuestos orgáni- cos, con una aplicación potencialmente amplia para usos medicinales e industriales.

La extracción y análisis de este tipo de metabolitos a partir de la flora de diversas regiones del planeta ha sido el objetivo del estudio de diversos grupos de trabajo, y en este caso se ha querido hacer un aporte al estado del conocimiento actual, realizando un estudio sobre la natu- raleza y la cantidad del tanino condensado que se puede extraer de la corteza de 11 especies arbóreas presentes en Costa Rica: guanacaste (Enterolobium cyclocarpum), alcornoque (Licania arborea), jobo (Spondias mom- bin), pochote (Pachira quinata), níspero (Manilkara chicle), almendro (Andira inermis), roble (Tabebuia rosea), cedro (Cedrela odorata), cenízaro (Samanea saman), pino (Pinus caribaea) y ciprés (Cupressus lusitanica).

Las muestras de corteza fueron preparadas, secadas y extraídas con etanol. Se analizaron los extractos etanóli- cos para determinar el contenido de taninos condensa- dos a través del número de Stiasny, y se caracterizaron mediante espectroscopía infrarroja (FT-IR).

Las especies con mayor proporción de material extraído fueron guanacaste (9.5841% m/m), pochote (15.0066% m/m), pino (19.3400% m/m) y ciprés (10.5300% m/m), mientras que los extractos con una mayor proporción de taninos condensados correspondieron a alcornoque (61.9% m/m), jobo (66.1% m/m), pochote (72.8% m/m), níspero (50.5% m/m), cedro (72.7% m/m) y pino (70.7% m/m).
Desarrollo de cultivos y alimentos por técnicas de biotecnología moderna en Centroamérica
Authors: Garro Monge Giovanni
Published: November 2015

En la última década, la adopción de Cultivos Genéticamente Modificados (CGM) se ha incre- mentado de forma escalonada a nivel mundial. El área sembrada con cultivos biotecnológicos llegó a un total de 148 millones de hectáreas en 2010, aumentando también el número de agricultores que decidieron producir este tipo de cultivos.

A nivel regional, se producen respuestas diversas de los órganos gubernamentales mediante reglamen- tos y normativas acordes con la realidad local. En Centroamérica, los países con mayor participación en el desarrollo y cultivo de alimentos utilizando técnicas de biotecnología moderna son Guatemala (papaya), Honduras (frijol y maíz) y Costa Rica (algodón, soya y piña). En el 2010, los dos últimos países estaban entre los 29 países con mayor siem- bra de CGM a nivel mundial. Algunos países de la región han implementado estructuras gubernamen- tales para la regulación por medio de comisiones técnicas de Bioseguridad.

Las características más importantes en términos del comercio siguen siendo aquellas que confieren tolerancia a herbicidas o resistencia a plagas. Sin embargo, se nota la incursión de nuevos productos que contienen modificaciones en su contenido y que se vislumbran como una alternativa con buenas perspectivas en la región.

Estas experiencias de cultivo y regulación en Bioseguridad a escala regional podrían suponer un desarrollo acertado y progresivo de la biotecnología agrícola y alimentaria en un futuro cercano.
Recursos hídricos de la Cuenca Alta del Río Tempisque, Costa Rica (Nota técnica)
Authors: Guzmán Arias Isabel , Calvo-Alvarado Julio César
Published: November 2015

El estudio aborda la situación de los recursos hídri- cos de la Cuenca Alta del Tempisque ubicada en la Provincia de Guanacaste, Costa Rica.

Se proporciona una breve descripción biofísica del área de estudio, así como el cálculo detallado de la disponibilidad y uso de los recursos hídricos. Se encontró que antes del 2005, las concesiones de agua, además de los requisitos recomendados de caudal ambiental para el río superó la disponibilidad de los flujos naturales durante la estación seca.

Se da una serie de recomendaciones con el fin de mantener los caudales ecológicos, evitar los conflic- tos sociales y satisfacer las demandas de agua de las comunidades, inversionistas agrícolas, el turismo y desarrollos inmobiliarios.
La carbonización de residuos biomásicos: una exploración con perspectivas emocionantes
Authors: Quesada Kimzey Jaime
Published: November 2015

Se da una idea general sobre el tema de la carbonización de residuos biomásicos, y se describen brevemente dos proyectos en esta área de investigación que en el primer semestre del 2012 se desarrollan en el Tecnológico de Costa Rica (TEC).Ambos proyectos están enfocados en la carbonización de residuos biomásicos del beneficiado del café y se realizan en colaboración con Coopetarrazú. El que dio inicio en el 2011 está dedicado a la carbonización de material seco, y abordará tanto el uso energético como el uso agrícola del biocarbón. El que dio inicio en el 2012 está enfocado en la carbonización hidrotérmica de biomasa presente en las aguamieles.
SIR-ZEE: plataforma tecnológica para el desarrollo local
Authors: Treviño Villalobos Marlen , Chaves Álvarez Marcela
Published: November 2015

El Sistema de Información Regional de la Zona Económica Especial (SIR-ZEE) nació en Costa Rica aproximadamente en 1998, cuando se concibió la idea de crear un sistema informático para recopilar, gestionar y ofrecer temáticas generadas en forma digital por diferentes entidades públicas y privadas. En el 2008, con los fondos del Programa de Regionalización Interuniversitaria del Consejo Nacional de Rectores, se aprobó la iniciativa SIR-ZEE, Plataforma Tecnológica para el Desarrollo Local, que buscó fortalecer las capacidades productivas y las capacidades de gobernabilidad en la Región Huetar Norte mediante el acceso a la información oportuna y relevante para el desarrollo económico local.

Este artículo tiene como objetivo mostrar no solo la relevancia de un sistema de información en la planificación del desarrollo local, sino también que, en la actualidad, el SIR-ZEE se está convirtiendo en una ventaja competitiva para la Región Huetar Norte, ya que facilita el proceso de toma decisiones. Los principales resultados obtenidos al final de la iniciativa fueron una propuesta metodológica para la elaboración de planes estratégicos de desarrollo local en la Región Huetar Norte, la sensibilización de los actores locales sobre la participación ciudadana en las diferentes fases de la planificación, un diagnóstico territorial con el valor agregado de contar con la información georreferenciada y disponible en un sitio web, y avances en la elaboración del Plan estratégico de desarrollo local.
Inversión extranjera directa, movilidad laboral y derrames de conocimiento en Costa Rica
Authors: Monge González Ricardo , Leiva Bonilla Juan Carlos , Rodríguez Álvarez Juan Antonio
Published: November 2015

Este trabajo busca determinar la existencia e importancia de los derrames de conocimiento asociados con la movilidad laboral desde las multinacionales (MNCS) que operan bajo el régimen de zonas francas (ZF) en Costa Rica; es decir, el impacto de tales derrames de conocimiento sobre el desempeño de las empresas locales que contratan ex empleados de MNCS. Se observó que, de un total de 41 149 empleados de MNCS que dejaron de laborar para estas empresas entre el 2001 y el 2007, un tercio se trasladó a empresas locales (15 139).

El impacto de los derrames de conocimiento sobre el desempeño de empresas locales se midió en términos de tres variables: ventas, empleo y productividad media del trabajo; para esto se empleó un panel de empresas locales para el periodo que va del 2007 al 2009. Mediante el empleo de modelos econométricos sugeridos por la literatura en este campo, se encontró evidencia de que las empresas locales que han contratado ex empleados de MNCS obtienen un mejor desempeño en términos de crecimiento de sus ventas y empleo, que aquellas empresas locales que no contratan ex empleados de MNCS. Es decir, se obtuvo una clara evidencia de la externalidad positiva asociada con los derrames de conocimiento para Costa Rica, producto de la movilidad laboral desde las MNCS. No se encontró esta evidencia cuando el desempeño de las empresas locales se mide en términos de la productividad media del trabajador.

Finalmente, los resultados señalan la importancia de llevar a cabo nuevas investigaciones sobre la capacidad de absorción de las empresas locales para potenciar más los impactos positivos de los derrames de conocimiento, así como respecto al impacto de tales derrames sobre la productividad total de los factores.
Simulation of laminar bimorph piezoelectric microactuators with application in miniaturized robots
Authors: Alfaro Barrantes Juan , Vega Castillo Paola , Vílchez Monge Marta , Rodríguez Montero Marco
Published: November 2015

In order to implement miniaturized robots different possibilities for electromechanical actuation at the microscale must be evaluated according to their function on the robot, as well as, size, mechanical strength and deformation, resolution, power supply, energy and degrees of freedom required. The piezoelectric actuators are among the most suitable possibilities to incorporate microactuators in miniaturized robots.This article presents an overview of piezoelectric actuation and the evaluation of a simple x-y micropositioning actuator for a miniaturized robot using COMSOL Multiphysics.
Spatial patterns in oxygen and redox sensitive biogeochemistry in tropical forest soils
Authors: Liptzin Daniel , Silver Whendee L.
Published: November 2015

Humid tropical forest soils are characterized by warm temperatures, abundant rainfall, and high rates of biological activity that vary considerably in both space and time. These conditions, together with finely textured soils typical of humid tropical forests lead to periodic low redox conditions, even in well‐drained upland environments. The relationship between redox and biogeochemical processes has been studied for decades in saturated environments like wetlands and sediments, but much less is known about redox dynamics in upland soils. The goal of this study was to understand the spatial variability of redox sensitive biogeochemistry within and across two forest types at the ends of a high rainfall gradient (3500 to 5000 mm y−1) in the Luquillo Experimental Forest, Puerto Rico. The two sites differed significantly in average soil chemical and physical properties, but the scale of variability was similar across sites, with greater variability in soil gas concentrations than extractable Fe and P. Soil P and Fe pools and trace gas concentrations were more strongly correlated with each other and exhibited more spatial structure at the wetter site. While the within‐site relationships among these redox sensitive variables were typically weak, the relationships across sites were much stronger. We provide a conceptual model that elucidates how the strength of the relationships between indicators of redox‐sensitive biogeochemical processes depends on the spatial scale of analysis.
Large, infrequent disturbance on a regulated river: response of floodplain forest birds to the 2011 Missouri River flood
Authors: Munes Eszter C. , Dixon Mark D. , Swanson David L. , Merkord Christopher L. , Benson Adam R.
Published: November 2015

Floodplain forests are dynamic habitats that support a high diversity and abundance of birds. Periodic flood disturbance is important in the establishment and maintenance of the heterogeneous mosaic of vegetation communities across the riverine landscape. Human suppression of disturbance regimes has been implicated in the decline of bird species in these systems. Because few large rivers are not subject to flood control by dams and levees, opportunities to study avian responses to flood disturbance are limited. A large magnitude, long‐duration flood event on the Missouri River, USA, during the summer of 2011 provided an opportunity to quantify post‐flood changes in forest bird densities and species richness relative to pre‐flood conditions on a riverine floodplain impacted by decades of flow regulation. We surveyed 75 forest sites on two segments of remnant floodplain forest along the Missouri National Recreational River (MNRR) in southeastern South Dakota and northeastern Nebraska and examined changes in density for 35 breeding landbird species from pre‐flood (2009–2010) to post‐flood (2012–2014) periods. We used a repeated measures ANOVA design to test the effects of year on average densities of birds and nesting guilds and confidence intervals to determine changes in densities of individual species and species richness. 19 of 35 focal species declined significantly one year after the flood (2012), but abundances of ten species recovered to pre‐flood densities or higher within two years. In 2012, density declines of six species and density increases of two species were significantly correlated with a decrease in woody vegetation density and percent shrub cover. Average bird densities and the density of shrub nesters rebounded in 2013 to pre‐flood levels and continued to increase through 2014. There were no significant changes in species richness at the level of forest habitat types between sampling years. Our results demonstrate short‐term resilience of floodplain bird species to a major disturbance despite declines in early successional habitat and minimal recovery of woody vegetation.
Summer range occupancy modeling of non‐native mountain goats in the greater Yellowstone area
Authors: DeVoe J. D. , Garrott R. A. , Rotella J. J. , Challender S. R. , White P. J. , O'Reilly M. , Butler C. J.
Published: November 2015

Non‐native species can have adverse impacts on native species. Predicting the potential extent of distributional expansion and abundance of an invading non‐native species can inform appropriate conservation and management actions. Non‐native mountain goats (Oreamnos americanus) in the greater Yellowstone area (GYA) have substantial potential to occupy similar habitats to native Rocky Mountain bighorn sheep (Ovis canadensis canadensis). To understand the potential for expansion of mountain goats in the GYA, this study evaluated detection‐nondetection data derived from ground‐based occupancy surveys of viewsheds partitioned into a grid of 100 × 100 m sampling units. Surveys were conducted over three summer seasons (2011–2013) in two study areas with well‐established mountain goat populations. Relationships between scale‐specific habitat covariates and mountain goat selection were evaluated to model occupancy and detection probabilities based on mountain goat detections in 505 of the 53,098 sampling units surveyed. Habitat selection was most strongly associated with terrain covariates, including mean slope and slope variance, at a spatial scale of 500 × 500 m, and canopy cover, heat load, and normalized difference vegetation index at a spatial scale of 100 × 100 m. These results provide new insight into multi‐scale patterns of mountain goat habitat selection, as well as evidence that mean slope and slope variance are more informative terrain covariates than distance to escape terrain, which has been commonly used in published mountain goat habitat models. The model predicted 9,035 km2 of suitable habitat within the GYA, of which 57% is currently un‐colonized. Seventy‐five percent of all bighorn observations recorded in the GYA fall within predicted suitable mountain goat habitat. We also estimated that the GYA might have the potential to support 5,331–8,854 mountain goats when all predicted habitat is occupied, or approximately 2.5–4.2 times the most recent abundance estimate of 2,354.
Thermal Operations In The McMurray; An Approach To Sand Control
Authors: O'Hara M.
Published: November 2015

For economic steam assisted gravity drainage (SAGD) (Butler, 1991) (producer/injector) horizontal well pairs have horizontal well lengths of 850 to over 1000 meters. Since the unconsolidated McMurray reservoir is made up of predominately quartz grains of variable sizes, these producing horizontal wells require liners that are capable of controlling the inflow of sand, minimizing pressure drops across the liner (clogging) and allowing unconstrained fluid production.

Devon Energy has developed a workflow to characterize the particle size and sorting of the reservoir into four statistical bins or sand types. Since numerous sand control technologies are now currently available to SAGD producer wells, Devon initiated a sand control and liner evaluation study to determine appropriate liner designs and aperture sizing specific to these known sand types. The study objective was to characterize the varying sands encountered in the Jackfish and Pike reservoirs, test these sands with industry sand control test procedures and recommend the optimal liner deployed sand screen technology.

This paper will provide a detailed overview of Devon's McMurray sand control test program and subsequent recommendation to deploy wire wrap screen for thermal producers with specific sand signatures. Devon will also introduce its own in-house designed sand control test apparatus.
Effect of Thermal Cycling on Cement Sheath Integrity: Realistic Experimental Tests and Simulation of Resulting Leakages
Authors: Vrålstad Torbjørn , Skorpa Ragnhild , Opedal Nils , De Andrade Jesus
Published: November 2015

The cement sheath is one of the most important well barrier elements in the well, both during production and after abandonment. However, normal production operations which involve temperature variations in the well, such as steam injection, stimulations and shut-down periods, may damage the integrity of the cement sheath. Temperature increase and decrease, i.e. thermal cycling, cause the casing to expand and contract, which creates debonding and cracking of the cement sheath and thereby loss of zonal isolation.

This paper presents novel results from an experimental study of cement sheath integrity during thermal cycling. The temperature was cycled repeatedly from 5 °C to 125 °C in a controlled manner from inside the casing, and Portland cement with silica additive was tested with both sandstone and shale as surrounding rock. Debonding and cracking of cement were quantified and visualized by X-ray computed tomography (CT), and it was found that cracking and debonding occurred for the sandstone sample, whereas the shale sample remained almost unaffected. There were some initial defects in the cement sheath in the sandstone sample, and these small and scattered defects grew together during thermal cycling into a continuous leak path; i.e. resulting in a loss of zonal isolation.

The digitalized 3D geometry of this leak path was imported into Computational Fluid Dynamics (CFD) software, thereby enabling a unique visualization of fluid flow through an actual leak path in degraded cement and an estimation of leak rates for different pressure differences. It is seen that microannuli are not homogeneous or uniform, and that fluid flow through microannuli and cracks is complex and not easily predictable.
On the adjacency dimension of graphs
Authors: Estrada-Moreno A. , Ramírez-Cruz Y. , Rodríguez-Velázquez J.A.
Published: November 2015

In this article we study the problem of finding the k-adjacency dimension of
a graph. We give some necessary and sufficient conditions for the existence
of a k-adjacency basis of an arbitrary graph G and we obtain general results
on the k-adjacency dimension, including general bounds and closed formulae
for some families of graphs.
Stepwise or concerted? DFT study on the mechanism of ionic Diels-Alder reaction of chromanes
Authors: Haghdadi Mina , Soghra Mousavi , Ghasemnejad Hassan
Published: November 2015

The stepwise and concerted Ionic Diels-Alder reaction between phenyl
(pyridin-2-ylmethylene) oxonium and styrene derivatives are explored using
theoretical method. The results support using computational method via
persistent intermediates. The DFT method was essential to reproduce a
reasonable potential energy surface for these challenging systems.
MESCOP
Authors: Balasha Tamir , Toledo Tomer
Published: November 2015

The design of traffic signal control has a profound impact on the performance of urban traffic systems. The current traffic signal plans involve complex control logic and have many parameters that need to be set. However, little attention has been given to the evaluation of these plans. Simulation-based signal optimization has been limited, mainly as a result of the heavy computational burden associated with it. This paper reports on the overall structure and the various components of a mesoscopic model for traffic simulation to evaluate and optimize complex actuated traffic signal plans. The model is named MESCOP (mesoscopic evaluation of signal control plans). MESCOP is detailed enough to represent the characteristics of actuated traffic signal plans, including the intersection layout and the detectors. The stochastic processes of the arrival at the intersection and the movement within it are also modeled in detail. The model represents passenger cars, transit vehicles, and pedestrians. The use of MESCOP is demonstrated through its application to a signalized intersection in Haifa, Israel. This intersection is controlled by an actuated traffic signal with transit priority and compensation and queue override mechanisms. Computationally, the results show that MESCOP is very efficient in comparison with microscopic models for traffic simulation, which are often used for similar evaluations. Evaluations of the intersection performance indicate a great potential for this model to improve the design of traffic signals.
Empirical Evaluation of Transit Signal Priority
Authors: Feng Wei , Figliozzi Miguel , Bertini Robert L.
Published: November 2015

Transit signal priority (TSP) can reduce transit delay at signalized intersections by making phasing adjustments. TSP is a relatively inexpensive and easily implemented tool to make transit service faster and more reliable. TSP also sends a signal that a city or region encourages the growth of transit. With the aim of assessing the performance of an existing TSP system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures were proposed. The results indicate that a timely and effective TSP system requires a high degree of sophistication, monitoring, and maintenance. Empirical data suggested that most TSP phase adjustments were granted within the cycle in which buses requested priority but that only a small proportion resulted in reduced delay. In this study, many green extension phases were granted late and were therefore less effective than early signal phases. Despite this situation, the TSP system did not increase delays for passengers and vehicles when side street traffic was considered.
Traffic Signal Battery Backup Systems
Authors: Zhao Mo , Sharma Anuj , Smaglik Edward , Overman Tim
Published: November 2015

A stable supply of power is a critical element in reliable traffic signal operation. Battery backup systems (BBSs) are often used to prevent traffic signals from experiencing power disruption. BBSs are designed through the use of engineering judgment because of a lack of operational requirements and well-defined performance measures. New high-resolution traffic controllers have the ability to record event-based data for power failures and traffic counts at a resolution of 0.1 s. With these high-resolution data, this paper proposes performance-based investment programming that uses the average annual signal downtime (AASD) over the analysis period as a performance measure. The AASD is stochastically estimated through the use of hazard-based duration models developed with power failure data. A volume and functional class–weighted stochastic optimization scheme is then presented for a BBS planning project, in which battery capacity is sized to minimize the AASD for a network under given budget constraints.
Study of Truck Driver Behavior for Design of Traffic Signal Yellow and Clearance Timings
Authors: Bryant Craig W. , Rakha Hesham A. , El-Shawarby Ihab
Published: November 2015

Traffic signal violations by drivers are a leading contributor to crashes at signalized intersections. The yellow indication is used to inform drivers of an upcoming change in the status of the traffic signal. Yellow interval durations are currently calculated to provide dilemma zone protection for passenger cars. Because of differences in vehicle characteristics and driver characteristics, heavy trucks such as tractor trailers behave differently at the onset of a yellow indication. This paper characterizes the difference in driver behavior between truck and light-duty vehicles at the onset of the yellow indication and then revises the yellow timing procedures to address the truck requirements. A data set of 910 stop–go records was collected through the use of a truck driving simulator located at the Virginia Tech Transportation Institute. From the data collected, statistical models were created to model driver perception–reaction times and deceleration levels with a consideration of driver attributes and the time to the intersection at the onset of the yellow indication. The data collected, along with the statistical models developed, were compared with the data collected and the statistical models created by the same research organization in a study of passenger car drivers. Last, a Monte Carlo simulation was conducted to develop appropriate yellow indication timings to provide adequate dilemma zone protection for trucks.
Delay of the Onset of Puberty in Female Rats by Prepubertal Exposure to T-2 Toxin
Authors: Yang Rong , Wang Yi-Mei , Zhang Li-Shi , Zhang Li , Zhao Zeng-Ming , Zhao Jun , Peng Shuang-Qing
Published: November 2015

Growing evidence has revealed the deleterious influence of environmental and food contaminants on puberty onset and development in both animals and children, provoking an increasing health concern. T-2 toxin, a naturally-produced Type A trichothecene mycotoxin which is frequently found in cereal grains and products intended for human and animal consumption, has been shown to impair the reproduction and development in animals. Nevertheless, whether this trichothecene mycotoxin can disturb the onset of puberty in females remains unclear. To clarify this point, infantile female rats were given a daily intragastric administration of vehicle or 187.5 μg/kg body weight of T-2 toxin for five consecutive days from postnatal day 15 to 19, and the effects on puberty onset were evaluated in the present study. The results revealed that the days of vaginal opening, first dioestrus, and first estrus in regular estrous cycle were delayed following prepubertal exposure to T-2 toxin. The relative weights of reproductive organs uterus, ovaries, and vagina, and the incidence of corpora lutea were all diminished in T-2 toxin-treated rats. Serum levels of gonadotropins luteinizing hormone, follicle-stimulating hormone, and estradiol were also reduced by T-2 toxin treatment. The mRNA expressions of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary GnRH receptor displayed significant reductions following exposure to T-2 toxin, which were consistent with the changes of serum gonadotropins, delayed reproductive organ development, and delayed vaginal opening. In conclusion, the present study reveals that prepubertal exposure to T-2 toxin delays the onset of puberty in immature female rats, probably by the mechanism of disturbance of hypothalamic-pituitary-gonadal (HPG) axis function. Considering the vulnerability of developmental children to food contaminants and the relative high level of dietary intake of T-2 toxin in children, we think the findings of the present study provide valuable information for the health risk assessment in children.
Suppression of autophagy by extracellular vesicles promotes myofibroblast differentiation in COPD pathogenesis
Authors: Fujita Yu , Araya Jun , Ito Saburo , Kobayashi Kenji , Kosaka Nobuyoshi , Yoshioka Yusuke , Kadota Tsukasa , Hara Hiromichi , Kuwano Kazuyoshi , Ochiya Takahiro
Published: November 2015

Extracellular vesicles (EVs), such as exosomes and microvesicles, encapsulate proteins and microRNAs (miRNAs) as new modulators of both intercellular crosstalk and disease pathogenesis. The composition of EVs is modified by various triggers to maintain physiological homeostasis. In response to cigarette smoke exposure, the lungs develop emphysema, myofibroblast accumulation and airway remodelling, which contribute to chronic obstructive pulmonary disease (COPD). However, the lung disease pathogenesis through modified EVs in stress physiology is not understood. Here, we investigated an EV‐mediated intercellular communication mechanism between primary human bronchial epithelial cells (HBECs) and lung fibroblasts (LFs) and discovered that cigarette smoke extract (CSE)‐induced HBEC‐derived EVs promote myofibroblast differentiation in LFs. Thorough evaluations of the modified EVs and COPD lung samples showed that cigarette smoke induced relative upregulation of cellular and EV miR‐210 expression of bronchial epithelial cells. Using co‐culture assays, we showed that HBEC‐derived EV miR‐210 promotes myofibroblast differentiation in LFs. Surprisingly, we found that miR‐210 directly regulates autophagy processes via targeting ATG7, and expression levels of miR‐210 are inversely correlated with ATG7 expression in LFs. Importantly, autophagy induction was significantly decreased in LFs from COPD patients, and silencing ATG7 in LFs led to myofibroblast differentiation. These findings demonstrate that CSE triggers the modification of EV components and identify bronchial epithelial cell‐derived miR‐210 as a paracrine autophagy mediator of myofibroblast differentiation that has potential as a therapeutic target for COPD. Our findings show that stressor exposure changes EV compositions as emerging factors, potentially controlling pathological disorders such as airway remodelling in COPD.
Self-assembly mechanism of Ni nanowires prepared with an external magnetic field
Authors: Li Xiaoyu , Wang Hu , Xie Kenan , Long Qin , Lai Xuefei , Liao Li
Published: November 2015

Nickel nanowires with a mean diameter of about 95 nm and lengths of up to 26 μm were prepared by a chemical reduction method in aqueous solution under an external magnetic field. The self-assembly mechanism was investigated in detail. The results indicate that the self-assembly process of Ni nanowires consists of three stages: nucleation and growth, ordered alignment and self-assembly, and deposition on the surface and gaps between the nickel particles. The self-assembly phenomenon occurs only when nickel particles grow to a size of about 60 nm in the reaction system. This critical size, which is proposed for the first time, is very important to comprehend the self-assembly mechanism of Ni nanowires prepared with an external magnetic field.
Tactics for Transforming the Housing Structure, New Housing Models Incision of the City, Connecting the Urban Fragments of the City of Skopje
Authors: Petanovski Aleksandar
Published: November 2015

As witnesses of the dynamic and increased extension and densification of the development of our urban spaces, we need a re-qualification of the values that we as members and professionals create in the urban environment in which we live in. Skopje is a fragmented city, consisted of a diverse morphological and social context and the permanence and transformation of the urban structure is in a constant conflict. Defining new tactics for transformation of the housing structure and presenting new models for housing is the new challenge that the city will be facing in order to create a homogeneous morphological and ideological identity. The research of the possible transformation offers a method which can be applied and adapted on versatile urban contexts and provide upgrade and integration of the program and volume of the city. In this research, the linear structure is chosen as a basic morphological element. Towards a better understanding of this formal act of positioning an axis, we first have to understand the political and social events from historical, social and cultural aspect. In the first part, the research is based on examples of the historical genesis of linear structures and examples regarding the research of linear structures or cities and in the second part, closing in on the study area of the city of Skopje and the east-west axis of development and growth of the city (the master plan of the architect Ludek Kubes in 1948). The method of incision is presented in the third part, incision or cutting through, from a theoretical aspect and superposing a linear structure as a tactic for transforming the urban morphology. The urban fragments are a distinctive phenomenon of the city of Skopje; the principals of informal transformation may offer a strategy that will succeed to unify and connect the contradictory condition, which is a consequence of different ideas, implementations and non-realization of plans and also of political, economic and other social factors.
Revision of Immediate Post–Open Heart Surgery Education for Critical Care RNs
Authors: Mowry Marianne J. , Gabel Mollie A.
Published: November 2015

Responding to the complex nature of critical care is imperative, as extensive clinical judgment is required during those vital moments when patients are experiencing complications related to open heart surgery, post–vessel bypass, or valve replacement. Critical care registered nurses must rely on evidence-based foundational knowledge and skills particular to cardiovascular pathophysiology, hemodynamic monitoring, and medications. This article reports on the critical care educator’s revision of the immediate post–open heart surgery curriculum. Mixed educational methods within the plan were foundational to develop clinicians for competent care of these complex patients (within the first 8 hours). The revision included experiential learning and learner centeredness to bolster the learner’s confidence, reduce the time to competence, and, most important, ensure positive patient outcomes. Kirkpatrick’s classic four-level model provided the framework for evaluation. Lessons learned were discussed following the program initiation.

J Contin Educ Nurs.
2015;46(11):508–514.
Writing Multiple Choice Outcome Questions to Assess Knowledge and Competence
Authors: Brady Erik D.
Published: November 2015

Few articles contemplate the need for good guidance in question item-writing in the continuing education (CE) space. Although many of the core principles of sound item design translate to the CE health education team, the need exists for specific examples for nurse educators that clearly describe how to measure changes in competence and knowledge using multiple choice items. In this article, some keys points and specific examples for nursing CE providers are shared.
J Contin Educ Nurs
. 2015;46(11):481–483.
Gait Analysis Using a Support Vector Machine for Lumbar Spinal Stenosis
Authors: Hayashi Hiroyuki , Toribatake Yasumitsu , Murakami Hideki , Yoneyama Takeshi , Watanabe Tetsuyou , Tsuchiya Hiroyuki
Published: November 2015

Lumbar spinal canal stenosis (LSS) is diagnosed based on physical examination and radiological documentation of lumbar spinal canal narrowing. Differential diagnosis of the level of lumbar radiculopathy is difficult in multilevel spinal stenosis. Therefore, the authors focused on gait analysis as a classification method to improve diagnostic accuracy. The goal of this study was to identify gait characteristics of L4 and L5 radiculopathy in patients with LSS and to classify L4 and L5 radiculopathy using a support vector machine (SVM). The study group comprised 13 healthy volunteers (control group), 11 patients with L4 radiculopathy (L4 group), and 22 patients with L5 radiculopathy (L5 group). Light-emitting diode markers were attached at 5 sites on the affected side, and walking motion was analyzed using video recordings and the authors' development program. Potential gait characteristics of each group were identified to use as SVM parameters. In the knee joint of the L4 group, the waveform was similar to that of normal gait, but knee extension at initial contact was slightly greater than that of the other groups. In the ankle joint of the L5 group, the one-peak waveform pattern with disappearance of the second peak was present in 10 (45.5%) of 22 cases. The total classification accuracy was 80.4% using the SVM. The highest and lowest classification accuracies were obtained in the control group (84.6%) and the L4 group (72.7%), respectively. The authors' walking motion analysis system identified several useful factors for differentiating between healthy individuals and patients with L4 and L5 radiculopathy, with a high accuracy rate. [
Orthopedics.
2015; 38(11):e959–e964.]
La preuve par l’image : Conan Doyle et la photographie
Authors: Stiegler Bernd
Published: November 2015

La photographie ne joue pratiquement aucun rôle dans la série de romans et récits de Conan Doyle mettant en scène Sherlock Holmes. En effet le détective y est défini comme « la machine de réflexion et d’observation la plus perfectionnée que le monde ait vue » : le photographe, c’est lui. Or Conan Doyle a créé une œuvre bien plus vaste que celle qu’on lui associe spontanément, riche de plus de cent volumes où la photographie joue un rôle-clef dans un nombre d’entre eux : ainsi sert-elle à la dénonciation des crimes colonialistes du roi Leopold II au Congo, ou à l’accréditation de la présence de dinosaures dans un « monde perdu ». Cet article s’intéresse à deux autres ensembles de textes de l’écrivain, liés à la photographie : ceux qui traitent du spiritisme et ceux qui s’attachent à la photographie des fées. D’abord hostile au spiritisme et même son adversaire, Doyle, s’y convertit progressivement et rendit public sa foi, déclarant écrire sous la dictée d’un personnage né avant Abraham, Phénéas, devant lequel il était une simple tablette de cire sur laquelle il puisse écrire. La photographie qui était au bénéfice d’une croyance dans sa véracité était ainsi mobilisée au service d’une autre forme de croyance celle dans les esprits. Enfin, Doyle accrédita l’authencité de photographies de fées lesquelles ne sont pas des êtres de l’au-delà comme les spectres mais nos contemporaines. Cette faculté de la photographie à rendre visible des mondes jusqu’alors invisibles est connue : la photographie radiographique, astrale ou micrographique en sont des exemples probants. La photographie fonctionne comme un médium de transfert entre différents champs de visibilité. Elle est un rapporteur, un messager du monde invisible qui apporte généralement des messages bienveillants et bienvenus. Elle est, selon la belle formule de l’astronome Jules Janssen, la « rétine du savant » qui ouvre au regard humain un champ d’observation nettement élargi.
Russian Cyberwarfare Taxonomy and Cybersecurity Contradictions between Russia and EU
Authors: Lukin Kimberly
Published: November 2015

This article analyzes the similarities and differences between the EU's and Russia's cyber preparedness, management structures, governmental security controls and cyber strategies. In comparing the cyber capabilities of the EU and Russia, we use military tactics and criteria as a basis for evaluating tactical, operational and strategic maturity. Russia has implemented cyberwar part of military strategic movements and certain taxonomy can be recognized in Russian based cyberattacks. Furthermore this study evaluates the following criteria: what are the EU's and Russia's procedures to prevent cyberwar, how their situational awareness is gathered and shared and is cyber used alongside with other military weaponry and tactics. This study claims that Russia has a better cyber war fighting capability than the EU countries. Based on the findings and recommendations in our article information can be used to create new threat models, to detect cyberattacks and finally point towards action to develop governmental cybersecurity in the EU.
AI-Based Cyber Defense for More Secure Cyberspace
Authors: Bogatinov Dimitar Stevo , Bogdanoski Mitko , Angelevski Slavko
Published: November 2015

The growing network attacks and intrusions have put the government organizations at a great risk. In cyberspace, humans have great limitations in data analyze and cyber defense because of the amount of data they have to process and the limited response time. Considering these parameters one of the best solutions is when the cyber defense mechanisms are AI (Artificial intelligence)-based because they can easily determine and respond to the attacks that are underway. The responses can be easily managed using man in the loop or fully atomized techniques. This chapter gives brief review of the usage of artificial intelligence in support of cyber defense, explains some useful applications that already exist, emphasizing the neural nets, expert systems and intelligent agents in cyber defense. Furthermore the chapter will propose a technical AI-based cyber defense model which can support the governmental and non-governmental efforts against cyber threats and can improve the success against malicious attack in the cyberspace.
Novel First Responder Digital Forensics Tool as a Support to Law Enforcement
Authors: Bogdanoski Mitko , Stoilkovski Marjan , Risteski Aleksandar
Published: November 2015

There are many freeware and commercial tools which can be used to provide forensics information based on dead and live forensics acquisition. The main problem with these tools is that in many cases the investigator cannot explain the script functionality and generated results and information during the trial. Because of this reason there is an increased need for developing and using script which can be easy explained and adapted to any analysis which should be made by the examiners. The chapter presents a novel developed First Responder script which can be used to perform a live and dead forensics analysis in support of Law Enforcement during the investigation process.
The Impact of Human Behavior on Cyber Security
Authors: Houston Nancy
Published: November 2015

Perhaps the greatest challenge to cyber security is that people are inherently behind each cyber problem as well as its solution. The reality is that people have been stealing secrets and information and attacking others for thousands of years; the technology of the Internet just allows it to happen at a faster pace and on a larger scale. This chapter describes aspects of human behavior that impact cyber security efforts. Cognitive overload, bias, incentives and behavioral traits all affect the decision making of both those who develop policy and strategy, those who fall victim to cyber attacks, and those who initiate cyber attacks. Although limited research has been completed on the behavioral aspects of cyber security, many behavioral principles and models are applicable to cyber security issues.
International Legal Aspects of Protecting Civilians and Their Property in the Future Cyber Conflict
Authors: Hadji-Janev Metodi
Published: November 2015

The post-Cold War reality has brought many changes that challenge political leaders, planners and operators. Using cyberspace to accomplish their political objectives, non-state actors and states have opened serious legal debates over the applicability of the international law of armed conflict principles in cyberspace. In this context, the article explores how the basic principles of International law of armed conflict will apply to the protection of the civilian population from the future cyber conflict. To accomplish this article addresses the ius ad bellum and the ius in bello aspects of cyber conflict.