bluuebunny/crossref_metadata_2025_split huggingface dataset:
Las Hipotecas de Mala Calidad y la Crisis Financiera Internacional. Sus Causas
Authors: Gastaldi Santiago 
Published: July 2014

Se analiza la crisis financiera internacional presente, nacida en el mercado hipotecario norteamericano, claramente identificable a partir de agosto de 2007. Las bolsas de valores entre ese momento y los primeros días de diciembre de 2008 mostraron significativas caídas en los principales papeles que se comercian en los distintos lugares del mundo y la elevada volatilidad de las cotizaciones caracterizó su performance. Al momento de escribir este artículo, las mejoras bursátiles llevan dos semanas consecutivas, lo que parece una respuesta a la importante tarea de salvatajes coordinados por parte de los países más avanzados del mundo en los últimos 90 días. La crisis ha sido tan intensa que hace que muchos analistas la comparen con la surgida luego del crac bursátil de octubre de 1929. Se teme que le siga, como en aquella época, un período de un año o dos años de fuerte recesión económica, cuando no de depresión. El escrito muestra, en el primer apartado, el sistema financiero y sus componentes a los fines de localizar el núcleo de la crisis. En el segundo detalla cómo esta crisis originada en los intermediarios financieros propiamente dichos –bien distinta a lo que es una crisis bancaria tradicional– puede llegar a afectar a los bancos y potencialmente al sistema monetario. En el tercer apartado, señala los elementos concurrentes que dieron lugar a la crisis actual, que son: la política de tasa de interés seguida por la Reserva Federal de EE.UU. a partir del año 2001, el relajamiento de los estándares sobre las condiciones económicas del deudor para hacerse del crédito –sobre todo del crédito inmobiliario–, y la falta de una adecuada regulación de las “finanzas estructuradas”. Estos elementos, en conjunción, permitieron potenciar el ratio de deuda sobre el patrimonio neto de los intermediarios financieros propiamente dichos y la aparición de problemas de riesgo moral, generándose burbujas especulativas sobre el mercado hipotecario. Éstas, al reventar, produjeron efectos disruptivos sobre el sistema financiero, tanto americano como de otros países avanzados del mundo, esparciéndose en forma de recesión en el sector real de las economías. En el escrito se señalan los hitos más notorios de esta crisis y las medidas que se fueron sucediendo para contrarrestarla. En los últimos apartados se esboza cómo será la estructura del sistema financiero, cómo serán los impactos sobre la economía real del país y las restricciones para el diseño de la política económica.
Educación Estadística en Venezuela. El Caso de la Educación Básica y Media, ¿Formando una Cultura Estadística?
Authors: Salcedo Audy 
Published: July 2014

Autores como Gal (2002) han señalado la importancia que tiene para un ciudadano actual contar con una cultura estadística para ejercer a plenitud su ciudadanía. La variedad de información estadística a la cual está expuesto el ciudadano cada día es sólo un indicador de la necesidad de la cultura estadística que le permita comprender toda esa información. De allí que las sociedades han incorporado contenidos de estadística en la educación formal. Este informe de investigación describe y analiza la educación estadística en Venezuela, particularmente el caso de la Educación Básica (EB) y Educación Media (EM). Se utiliza una metodología de análisis documental para comparar los programas de estudios de matemáticas en EB y la EM venezolanos con los elementos que considera Gal (2002) necesarios para formar una cultura estadística. Posteriormente se consideran algunos indicadores de la enseñanza y el aprendizaje de la estadística en la EB y EM. Para ello se analizan los resultados de un cuestionario suministrado a docentes de matemática respecto a la enseñanza y los resultados del Sistema Nacional de Medición y Evaluación del Aprendizaje en cuanto a estadística, así como la Prueba Nacional de Ingreso a la Educación Superior (Prueba de Aptitud Académica). Los resultados de la comparación de los programas indican que los programas venezolanos son poco ambiciosos en cuanto a las metas que desean alcanzar para la formación de una cultura estadística del ciudadano egresado de la EB y EM. A esto se le une los indicadores considerados sobre enseñanza y aprendizaje, los cuales señalan que hay problemas en ambos aspectos. Al parecer, pocos docentes trabajan los contenidos de estadística en los niveles señalados y los estudiantes muestran poco dominio de las nociones fundamentales de esta disciplina. Pareciera que los egresados de la EB y EM adquieren pocos elementos de la cultura estadística durante su paso por esos niveles educativos.
La Enseñanza de la Inferencia Estadística en Carreras donde la Estadística Cumple un Rol Instrumental
Authors: Terán Teresita E. 
Published: July 2014

El trabajo que se presenta se plantea y justifica a partir del problema que surge en la enseñanza de la Estadística en carreras de grado no estadísticas. En relación a la Inferencia Estadística, ésta es una de las grandes ramas de la Estadística y una herramienta metodológica fundamental en las ciencias empíricas ya que trata el asunto de la confianza en las conclusiones estadísticas. En cursos básicos de Ciencias Económicas, Ingeniería y Ciencias Veterinarias el aprendizaje de los temas relativos a Inferencia Estadística se considera difícil y los resultados insatisfactorios. La tecnología, por su parte, en el momento actual influye en el qué y cómo enseñar, lo que acentúa la necesidad de una continua revisión de contenidos y métodos condicionada por las hipótesis previas que determinan el aprendizaje. A través de un análisis bibliográfico de distintos autores sobre el tema, se perfila un marco teórico relativo a la cognición estadística y se acota un campo de estudio que permita hacer un aporte investigativo en la comprensión de aquellos temas en los que se detecten mayores dificultades y proponer una trayectoria didáctica. Se plantea este trabajo desde la Didáctica de la Estadística y desde la propia práctica docente como profesora de cursos introductorios de Estadística para alumnos de diversas especialidades, partiendo de los siguientes interrogantes: ¿cuál es el nivel de comprensión de los alumnos, sobre el tema, en un primer curso de Estadística de la universidad?; ¿existen desajustes entre lo que se pretende enseñar y lo que se aprende?; ¿qué dificultades y errores se pueden detectar?, ¿cuáles son los obstáculos de los cuáles devienen?; ¿qué propuestas teóricas en Educación Estadística nos proporcionan herramientas convenientes para el análisis conceptual y semiótico de temas de la Inferencia Estadística?; ¿qué metodología didáctica podría facilitar un aprendizaje significativo de determinados temas de la Inferencia Estadística?
Improved Performance Investigations on OFDM-RoF Transmission Links Using ODSB and OSSB Modulation Techniques
Authors: Kumar Naresh , Sharma Ajay K. , Kapoor Vinod 
Published: July 2014

AbstractIn this work, simulative investigation to evaluate the performance of OFDM-RoF transmission links using ODSB and OSSB modulation schemes at high transmission rate is reported. Further, the results have been reported by compensating the degradations introduced by fiber dispersion using DC fiber for the proposed SSB-OFDM-RoF transmission links and a comparison is presented for evaluating the performance of such systems with and without DC fiber. Our result shows that the OSSB performs better than ODSB modulation scheme as the later severely suffered with fading problems due to fiber dispersion. In case of OSSB with DC fiber dispersion compensation technique, an improvement in SNR ratio and total power received is achieved in comparison to OSSB without DC fiber.
MicroRNA‐125b induces tau hyperphosphorylation and cognitive deficits in Alzheimer's disease
Authors: Banzhaf‐Strathmann Julia , Benito Eva , May Stephanie , Arzberger Thomas , Tahirovic Sabina , Kretzschmar Hans , Fischer André , Edbauer Dieter 
Published: July 2014

AbstractSporadic Alzheimer's disease (AD) is the most prevalent form of dementia, but no clear disease‐initiating mechanism is known. Aβ deposits and neuronal tangles composed of hyperphosphorylated tau are characteristic for AD. Here, we analyze the contribution of microRNA‐125b (miR‐125b), which is elevated in AD. In primary neurons, overexpression of miR‐125b causes tau hyperphosphorylation and an upregulation of p35, cdk5, and p44/42‐MAPK signaling. In parallel, the phosphatases DUSP6 and PPP1CA and the anti‐apoptotic factor Bcl‐W are downregulated as direct targets of miR‐125b. Knockdown of these phosphatases induces tau hyperphosphorylation, and overexpression of PPP1CA and Bcl‐W prevents miR‐125b‐induced tau phosphorylation, suggesting that they mediate the effects of miR‐125b on tau. Conversely, suppression of miR‐125b in neurons by tough decoys reduces tau phosphorylation and kinase expression/activity. Injecting miR‐125b into the hippocampus of mice impairs associative learning and is accompanied by downregulation of Bcl‐W, DUSP6, and PPP1CA, resulting in increased tau phosphorylation in vivo. Importantly, DUSP6 and PPP1CA are also reduced in AD brains. These data implicate miR‐125b in the pathogenesis of AD by promoting pathological tau phosphorylation.
Pediatric Advance Directives: Parents’ Knowledge, Experience, and Preferences
Authors: Liberman Danica B. , Pham Phung K. , Nager Alan L. 
Published: July 2014

OBJECTIVES:To explore parents’ and caregivers’ experience, knowledge, and preferences regarding advance directives (ADs) for children who have chronic illness.METHODS:We conducted a prospective, cross-sectional survey of parents and caregivers of children who have chronic illness. During ambulatory medical visits, participants were asked about previous AD experience and knowledge, future preferences regarding AD discussions, their child’s past and current health status, and family demographics.RESULTS:Among 307 participants surveyed, previous AD experience was low, with 117 (38.1%) having heard of an AD, 54 (17.6%) having discussed one, and 77 (25.1%) having known someone who had an AD. Furthermore, 27 (8.8%) participants had an AD or living will of their own, and 8 (2.6%) reported that their chronically ill child had an AD. Previous AD knowledge was significantly more likely among parents and caregivers who had a college degree than those who did not have a high school diploma, yet significantly less likely among primarily Spanish-speaking parents and caregivers than those primarily English-speaking. Interest in creating an AD for the child was reported by 151 (49.2%) participants, and was significantly more likely among families who had more frequent emergency department visits over the previous year.CONCLUSIONS:The limited AD experience and knowledge of parents and caregivers of children who have chronic illness and their interest in creating an AD suggest an unmet need among families of children who have chronic illness, and an opportunity to enhance communication between families and medical teams regarding ADs and end-of-life care.
Socioeconomic Status and Wait Times for Pediatric Surgery in Canada
Authors: Szynkaruk Mark , Stephens Derek , Borschel Gregory H. , Wright James G. 
Published: July 2014

OBJECTIVES:
Even in a publicly funded health care system, access to care may be related to socioeconomic status (SES). For children, delays in surgical procedures can have profound functional, social, and psychological effects with lifelong impact. The purpose of this study was to determine whether SES was related to meeting surgical wait time access targets for children. We also assessed the effects of gender, age, and distance to hospital on meeting access targets.

METHODS:
Patient addresses, referral wait times, and surgical wait times were obtained for 39 287 surgical procedures between 2005 and 2011 at the Hospital for Sick Children. Using census data, we derived household income quintile, distance to hospital, and indices of social and material deprivation. These indices were correlated with the percentage of children meeting clinic referral wait time targets and receiving surgery within the Pediatric Canadian Access Targets for Surgery.

RESULTS:
Across all SES quintiles, 33% of children exceeded their referral wait time targets, and 28% of children exceeded their surgical wait time targets. Indices of material or social deprivation and age did not correlate with the time from referral to clinic consultation (P = .54, .40, and .58, respectively). Gender was statistically significant (P &lt; .001), but the difference was small (odds ratio = 0.87 for girls). Distance was also statistically significant (P = .005), and these differences translate into clinically meaningful differences in meeting wait time targets. Regarding completion of surgical procedures, material deprivation, distance, and gender did not correlate with longer wait times for surgery (P = .44, .09, .59, respectively). Social deprivation was statistically significant (P = .02) but not clinically significant. Increasing patient age was significantly associated with increased proportion of out-of-window wait times (P &lt; .001). SES did not affect the timeliness of completion of surgery even when the urgency of the surgery (priority level based on diagnosis) was considered.

CONCLUSIONS:
SES does not predict the timeliness of delivery for pediatric surgical services.
Stool Microbiota and Vaccine Responses of Infants
Authors: Huda M. Nazmul , Lewis Zachery , Kalanetra Karen M. , Rashid Mamunur , Ahmad Shaikh M. , Raqib Rubhana , Qadri Firdausi , Underwood Mark A. , Mills David A. , Stephensen Charles B. 
Published: July 2014

OBJECTIVE:
Oral vaccine efficacy is low in less-developed countries, perhaps due to intestinal dysbiosis. This study determined if stool microbiota composition predicted infant oral and parenteral vaccine responses.

METHODS:
The stool microbiota of 48 Bangladeshi infants was characterized at 6, 11, and 15 weeks of age by amplification and sequencing of the 16S ribosomal RNA gene V4 region and by Bifidobacterium-specific, quantitative polymerase chain reaction. Responses to oral polio virus (OPV), bacille Calmette-Guérin (BCG), tetanus toxoid (TT), and hepatitis B virus vaccines were measured at 15 weeks by using vaccine-specific T-cell proliferation for all vaccines, the delayed-type hypersensitivity skin-test response for BCG, and immunoglobulin G responses using the antibody in lymphocyte supernatant method for OPV, TT, and hepatitis B virus. Thymic index (TI) was measured by ultrasound.

RESULTS:
Actinobacteria (predominantly Bifidobacterium longum subspecies infantis) dominated the stool microbiota, with Proteobacteria and Bacteroidetes increasing by 15 weeks. Actinobacteria abundance was positively associated with T-cell responses to BCG, OPV, and TT; with the delayed-type hypersensitivity response; with immunoglobulin G responses; and with TI. B longum subspecies infantis correlated positively with TI and several vaccine responses. Bacterial diversity and abundance of Enterobacteriales, Pseudomonadales, and Clostridiales were associated with neutrophilia and lower vaccine responses.

CONCLUSIONS:
Bifidobacterium predominance may enhance thymic development and responses to both oral and parenteral vaccines early in infancy, whereas deviation from this pattern, resulting in greater bacterial diversity, may cause systemic inflammation (neutrophilia) and lower vaccine responses. Vaccine responsiveness may be improved by promoting intestinal bifidobacteria and minimizing dysbiosis early in infancy.
Analysis of Portable Machine Tool Construction Containing Modular Components
Authors: Pawełko Piotr , Dolata Michał 
Published: July 2014

Summary
The article presents the issue of designing portable machine tools in which module components are applied. Portable machine tools are mainly designed for machining of elements at the place of their final installation. Experience has shown that achieving high efficiency in the design of portable machine tools can only be reached through the use of mechatronic approach with the use of ready-made modular components (for example: ballscrew mechanisms, bearing units, linear guide systems). The designer of a machine tool must be aware of lack of information on selected parameters of these components. It is recommended to use simplified replacement models of these components and implement them to the model of entire machine tool to achieve desired static and dynamic characteristics. Authors of the article present an example of a modular component and its replacement model. They also present the results of calculations performed with the use of this.
Experimental Investigations of Normal Deformation Characteristics of Foundation Chocks Used in the Seating of Heavy Machines and Qevices Part II. Experimental Investigations of a Chock Cast of EPY Resin
Authors: Grudziński Paweł , Konowalski Konrad 
Published: July 2014

Summary
This paper concerns in general the problem of the so-called rigid seatings of heavy machines and devices on foundations, by using foundation chocks traditionally made of steel, and now being more frequently replaced by foundation chocks cast of polymer materials specially developed for this purpose. It is a continuation and development of this problem tackled in Part I [1]. In that part, the technical and scientific aspects of the so-called rigid fastenings of machines to foundations have been discussed, and it has been shown that they are not perfectly rigid. Next, a description of the method and results of experimental studies of deformations carried out for a traditionally used steel chock has been presented. In Part II, described in this paper, the results of similar studies carried out for a chock cast of EPY resin, used nowadays more frequently for this purpose have been presented. Subsequently, a comparative analysis of the test results obtained for the two chocks investigated have been made and an explanation why the foundation chocks cast of polymer plastic fulfil better their tasks in machinery seatings than the traditionally used for this purpose steel chocks has been given.
The Influence of Technological Parameters and Geometric Features of a Cutting Edge on Cutting Forces during AZ91HP Alloy Milling
Authors: Gziut Olga , Kuczmaszewski Józef , Zagórski Ireneusz 
Published: July 2014

Summary
This article presents the state of knowledge on cutting forces during the milling of light alloys. Research results presented in the paper concern cutting forces and their amplitudes depending on the technological parameters (vc, fz, ap) with the use of two carbide milling cutters having a different cutting edge geometry (Y=5° and Y=30°). Research and analysis of cutting forces appear to be a significant factor determining chip deformation, temperature and cutting area strain, among others. Lower values of cutting force components are observed in the case of Y=30° tool processing. For the purpose of this research casting magnesium alloy AZ91HP was selected.
The Effect of Salinity Stress on Germination Characteristics and Changes Of Biochemically of Sesame Seeds
Authors: Tabatabaei S.A. , Naghibalghora S.M. 
Published: July 2014

Abstract
Objective of this study was to evaluate the effect of salinity stress on germination characteristics and biochemical changes of sesame seeds. Salinity stress at osmotic potentials of 0 (as control), ⊟3, ⊟6, ⊟9 and ⊟12 bar were adjusted using NaCl before the start of the experiment. Our results showed that, the effect of salinity stress for all traits was significant. By increases of salinity stress, germination percentage, germination, normal seedling percentage, seedling length and dry weight were reduced the ascorbate peroxidase and catalase activity, also proline content were at minimum at control and increased with increase in salinity stress, expressed by the osmotic potential.
Ecological Risk and Economic Loss Estimation of Heavy Metals Pollution in The Beijiang River
Authors: He Jiajun , Zhang Huimin , Zhang Hui , Guo Xuan , Song Mingwei , Zhang Junhao , Li Xiaotao 
Published: July 2014

Abstract
The distribution and extent of heavy metal accumulation in the fluvial sediment of the Beijiang River are described. The potential toxicity of this pollution was quantified using a consensus based sediment quality guidelines (SQGs) method and the Hakanson potential ecological risk index. The concentrations of Hg, As, Cu, Zn, Pb, Ni and Cr were high enough to damage the sediment biota on a frequent basis. The potential ecological risk was much higher in the downstream, urbanized reaches of the river than in the upstream reaches which are still rural, but all sections of the river posed at least a moderate level of ecological risk. Estimates of the economic loss associated with these pollutions were appreciable, and were mainly due to Hg and Cu. The Beijiang River basin is heavily polluted, posing environmental risks for the downstream reaches of the Pearl River, and economic loss to the whole watershed.
Influence of Wastewater Treatment and The Method of Sludge Disposal on the Gasification Process
Authors: Werle Sebastian , Dudziak Mariusz 
Published: July 2014

Abstract
Municipal wastewater treatment results in the production of large quantities of sewage sludge, which requires proper environmentally accepted management before final disposal. Sewage sludge is a by-product of current wastewater treatment technologies. Sewage sludge disposal depends on the sludge treatment methods used in the wastewater treatment plant (anaerobic or aerobic digestion, drying, etc.). Taking into consideration presented given this information, a study concerning the effects of wastewater treatment processes and sewage sludge drying method on the sewage sludge gasification gas parameters was performed. Gasification is a prospective alternative method of sludge thermal treatment. For the purpose of experimental investigations, a laboratory fixed bed gasifier installation was designed and built. Two types of sewage sludge feedstock, SS1 and SS2, were analyzed. Sewage sludge SS1 came from a wastewater treatment plant operating in the mechanical and biological system while sewage sludge SS2 was collected in a mechanical, biological and chemical wastewater treatment plant with simultaneous phosphorus precipitation. The sludge produced at the plants was subject to fermentation and then, after being dehydrated, dried in a cylindrical drier on shelves heated up to 260ºC (sewage sludge SS1) and using hot air at a temperature of 150ºC in a belt drier (sewage SS2). The analysis shows that the sewage sludge properties strongly depend on the wastewater sources and the wastewater treatment processes. The gasification results, presented as a function of the amount of gasification agent, show that the greater oxygen content of SS1 caused a reduction in the reaction temperature. Paradoxically, this effect caused an increase in the quantity of combustible components in the gas. As expected, increasing the air flow rate caused a decrease in the heating value of the gas produced. A higher amount of oxidizer increases the amounts of noncombustible species and the volumetric fraction of nitrogen, thus reducing the heating value of the obtained gas. The higher hydrogen content in SS1 affects the gasification gas composition. As a result, combustible components are the majority of the syngas.