bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensing the Environment: Student-Created Water Quality Sensors
Authors: Hotaling Liesl , Stolkin Rustam
Published: August 2015

AbstractThe Student Enabled Network of Sensors for the Environment using Innovative Technology (SENSE IT) program provides an infrastructure and curricula for teachers and students to learn core science, technology, engineering, and mathematics (STEM) knowledge through building,
testing, programming, and deploying their own environmental monitoring sensor networks. The project prepares and motivates middle and high school students for the future STEM workforce by providing (1) a motivating, meaningful, and hands-on environment for learning a wide range of STEM topics;
(2) an engaging link between biological, physical, and social sciences; and (3) a cutting-edge example of scientific and engineering research, delivered directly into the classroom. This paper describes the structure and impact of the SENSE IT project field test with over 90 teachers and 3,000
middle and high school students. Project evaluation results indicate that the curriculum was well received by teachers and students and could be integrated into several different subject areas and types of courses. SENSE IT proved effective for a wide range of students demonstrated by statistically
significant learning gains in mathematics and electricity topics through a pretest and posttest analysis. As SENSE IT evolves, additional sensors and educational materials will be created to support a variety of microprocessors.
The Challenges and Opportunities of Using Data in Teaching From the Perspective of Undergraduate Oceanography Professors
Authors: McDonnell Janice , Lichtenwalner Sage , Glenn Scott , Ferraro Carrie , Hunter-Thomson Kristin , Hewlett Jim
Published: August 2015

AbstractA community survey of undergraduate professors was conducted along with subsequent interviews of community college professors to gather information on the practices and teaching needs of members of the oceanographic community. Our objective was to capture how undergraduate
professors are currently using oceanographic data in their teaching, to what degree they are using inquiry in their undergraduate teaching, and information on what effective practices exist for teaching with data. The majority of those surveyed (73%) indicated that they have used data in their
teaching within the last year. Professors reported they found it useful to integrate data in their teaching to help students draw conclusions from evidence. Professors reported they are using online archived data, journal publications, and data that the professors had collected themselves.
The lowest percentage of professors indicated that they use online real-time data. Results indicate that professors were very likely to use a lecture (no inquiry) teaching strategy when using data in their classes. When asked where they could use the most help in improving their practice with
teaching with data, responses varied by career stage. There is a need for more exploration of effective practices for the integration of data into teaching and the need for data visualization tools that help undergraduate professors meet the demands of teaching 21st century science skills
and practices.
Decreased T Follicular Regulatory Cell/T Follicular Helper Cell (TFH) in Simian Immunodeficiency Virus–Infected Rhesus Macaques May Contribute to Accumulation of TFH in Chronic Infection
Authors: Chowdhury Ankita , Del Rio Perla Maria Estrada , Tharp Greg K. , Trible Ronald P. , Amara Rama R. , Chahroudi Ann , Reyes-Teran Gustavo , Bosinger Steven E. , Silvestri Guido
Published: August 2015

T follicular helper cells (TFH) are critical for the development and maintenance of germinal center (GC) and humoral immune responses. During chronic HIV/SIV infection, TFH accumulate, possibly as a result of Ag persistence. The HIV/SIV-associated TFH expansion may also reflect lack of regulation by suppressive follicular regulatory CD4+ T cells (TFR). TFR are natural regulatory T cells (TREG) that migrate into the follicle and, similar to TFH, upregulate CXCR5, Bcl-6, and PD1. In this study, we identified TFR as CD4+CD25+FOXP3+CXCR5+PD1hiBcl-6+ within lymph nodes of rhesus macaques (RM) and confirmed their localization within the GC by immunohistochemistry. RNA sequencing showed that TFR exhibit a distinct transcriptional profile with shared features of both TFH and TREG, including intermediate expression of FOXP3, Bcl-6, PRDM1, IL-10, and IL-21. In healthy, SIV-uninfected RM, we observed a negative correlation between frequencies of TFR and both TFH and GC B cells, as well as levels of CD4+ T cell proliferation. Post SIV infection, the TFR/TFH ratio was reduced with no change in the frequency of TREG or TFR within the total CD4+ T cell pool. Finally, we examined whether higher levels of direct virus infection of TFR were responsible for their relative depletion post SIV infection. We found that TFH, TFR, and TREG sorted from SIV-infected RM harbor comparable levels of cell-associated viral DNA. Our data suggest that TFR may contribute to the regulation and proliferation of TFH and GC B cells in vivo and that a decreased TFR/TFH ratio in chronic SIV infection may lead to unchecked expansion of both TFH and GC B cells.
IL-9 Expression by Invariant NKT Cells Is Not Imprinted during Thymic Development
Authors: Monteiro Marta , Agua-Doce Ana , Almeida Catarina F. , Fonseca-Pereira Diogo , Veiga-Fernandes Henrique , Graca Luis
Published: August 2015

Invariant NKT (iNKT) cell thymic development can lead to distinct committed effector lineages, namely NKT1, NKT2, and NKT17. However, following identification of IL-9–producing iNKT cells involved in mucosal inflammation, their development remains unaddressed. In this study, we report that although thymic iNKT cells from naive mice do not express IL-9, iNKT cell activation in the presence of TGF-β and IL-4 induces IL-9 secretion in murine and human iNKT cells. Acquisition of IL-9 production was observed in different iNKT subsets defined by CD4, NK1.1, and neuropilin-1, indicating that distinct functional subpopulations are receptive to IL-9 polarization. Transcription factor expression kinetics suggest that regulatory mechanisms of IL-9 expression are shared by iNKT and CD4 T cells, with Irf4 and Batf deficiency deeply affecting IL-9 production. Importantly, adoptive transfer of an enriched IL-9+ iNKT cell population leads to exacerbated allergic inflammation in the airways upon intranasal immunization with house dust mite, confirming the ability of IL-9–producing iNKT cells to mediate proinflammatory effects in vivo, as previously reported. Taken together, our data show that peripheral iNKT cells retain the capacity of shaping their function in response to environmental cues, namely TGF-β and IL-4, adopting an IL-9–producing NKT cell phenotype able to mediate proinflammatory effects in vivo, namely granulocyte and mast cell recruitment to the lungs.
Human Mucosa-Associated Invariant T Cells Accumulate in Colon Adenocarcinomas but Produce Reduced Amounts of IFN-γ
Authors: Sundström Patrik , Ahlmanner Filip , Akéus Paulina , Sundquist Malin , Alsén Samuel , Yrlid Ulf , Börjesson Lars , Sjöling Åsa , Gustavsson Bengt , Wong S. B. Justin , Quiding-Järbrink Marianne
Published: August 2015

Mucosa-associated invariant T (MAIT) cells are innate-like T cells with a conserved TCR α-chain recognizing bacterial metabolites presented on the invariant MHC-related 1 molecule. MAIT cells are present in intestinal tissues and liver, and they rapidly secrete IFN-γ and IL-17 in response to bacterial insult. In colon cancer, IL-17–driven inflammation promotes tumor progression, whereas IFN-γ production is essential for antitumor immunity. Thus, tumor-associated MAIT cells may affect antitumor immune responses by their secreted cytokines. However, the knowledge of MAIT cell presence and function in tumors is virtually absent. In this study, we determined the frequency, phenotype, and functional capacity of MAIT cells in colon adenocarcinomas and unaffected colon lamina propria. Flow cytometric analyses showed significant accumulation of MAIT cells in tumor tissue, irrespective of tumor stage or localization. Colonic MAIT cells displayed an activated memory phenotype and expression of chemokine receptors CCR6 and CCR9. Most MAIT cells in unaffected colon tissues produced IFN-γ, whereas only few produced IL-17. Colonic MAIT cells also produced TNF-α, IL-2, and granzyme B. In the tumors, significantly lower frequencies of IFN-γ–producing MAIT cells were seen, whereas there were no differences in the other cytokines analyzed, and in vitro studies showed that secreted factors from tumor tissue reduced IFN-γ production from MAIT cells. In conclusion, MAIT cells infiltrate colon tumors but their ability to produce IFN-γ is substantially reduced. We suggest that MAIT cells have the capacity to promote local immune responses to tumors, but factors in the tumor microenvironment act to reduce MAIT cell IFN-γ production.
The Neurorepellent Slit2 Inhibits Postadhesion Stabilization of Monocytes Tethered to Vascular Endothelial Cells
Authors: Mukovozov Ilya , Huang Yi-Wei , Zhang Qiuwang , Liu Guang Ying , Siu Allan , Sokolskyy Yaroslav , Patel Sajedabanu , Hyduk Sharon J. , Kutryk Michael J. B. , Cybulsky Myron I. , Robinson Lisa A.
Published: August 2015

The secreted neurorepellent Slit2, acting through its transmembrane receptor, Roundabout (Robo)-1, inhibits chemotaxis of varied cell types, including leukocytes, endothelial cells, and vascular smooth muscle cells, toward diverse attractants. The role of Slit2 in regulating the steps involved in recruitment of monocytes in vascular inflammation is not well understood. In this study, we showed that Slit2 inhibited adhesion of monocytic cells to activated human endothelial cells, as well as to immobilized ICAM-1 and VCAM-1. Microfluidic live cell imaging showed that Slit2 inhibited the ability of monocytes tethered to endothelial cells to stabilize their actin-associated anchors and to resist detachment in response to increasing shear forces. Transfection of constitutively active plasmids revealed that Slit2 inhibited postadhesion stabilization of monocytes on endothelial cells by preventing activation of Rac1. We further found that Slit2 inhibited chemotaxis of monocytes toward CXCL12 and CCL2. To determine whether Slit2 and Robo-1 modulate pathologic monocyte recruitment associated with vascular inflammation and cardiovascular disease, we tested PBMC from patients with coronary artery disease. PBMC from these patients had reduced surface levels of Robo-1 compared with healthy age- and sex-matched subjects, and Slit2 failed to inhibit chemotaxis of PBMC of affected patients, but not healthy control subjects, toward CCL2. Furthermore, administration of Slit2 to atherosclerosis-prone LDL receptor–deficient mice inhibited monocyte recruitment to nascent atherosclerotic lesions. These results demonstrate that Slit2 inhibits chemotaxis of monocytes, as well as their ability to stabilize adhesions and resist detachment forces. Slit2 may represent a powerful new tool to inhibit pathologic monocyte recruitment in vascular inflammation and atherosclerosis.
Macrophages and Myeloid Dendritic Cells Lose T Cell–Stimulating Function in Simian Immunodeficiency Virus Infection Associated with Diminished IL-12 and IFN-α Production
Authors: Wonderlich Elizabeth R. , Wu Wen-Chi , Normolle Daniel P. , Barratt-Boyes Simon M.
Published: August 2015

Impaired T cell responses are a defining characteristic of HIV infection, but the extent to which altered mononuclear phagocyte function contributes to this defect is unclear. We show that mononuclear phagocytes enriched from rhesus macaque lymph nodes have suppressed ability to stimulate CD4 T cell proliferation and IFN-γ release after acute SIV infection. When individual populations were isolated, myeloid dendritic cells (mDC) and macrophages but not plasmacytoid DC (pDC) had suppressed capacity to stimulate CD4 T cell proliferation, with macrophage function declining as infection progressed. Macrophages, but not pDC or mDC, had suppressed capacity to induce IFN-γ release from CD4 T cells in acute infection, even after stimulation with virus-encoded TLR7/8 ligand. Changes in expression of costimulatory molecules did not explain loss of function postinfection. Conversely, pDC and mDC had marked loss of IFN-α and IL-12 production, respectively, and macrophages lost production of both cytokines. In T cell cocultures without TLR7/8 ligand, macrophages were the primary source of IL-12, which was profoundly suppressed postinfection and correlated with loss of IFN-γ release by T cells. TLR7/8-stimulated pDC, mDC and macrophages all produced IL-12 in T cell cocultures, which was suppressed in chronic infection. Supplementing IL-12 enhanced mDC-driven IFN-γ release from T cells, and IL-12 and IFN-α together restored function in TLR7/8-activated macrophages. These findings reveal loss of macrophage and mDC T cell–stimulating function in lymph nodes of SIV-infected rhesus macaques associated with diminished IL-12 and IFN-α production that may be a factor in AIDS immunopathogenesis.
Vaccination Produces CD4 T Cells with a Novel CD154–CD40-Dependent Cytolytic Mechanism
Authors: Coler Rhea N. , Hudson Thomas , Hughes Sean , Huang Po-wei D. , Beebe Elyse A. , Orr Mark T.
Published: August 2015

The discovery of new vaccines against infectious diseases and cancer requires the development of novel adjuvants with well-defined activities. The TLR4 agonist adjuvant GLA-SE elicits robust Th1 responses to a variety of vaccine Ags and is in clinical development for both infectious diseases and cancer. We demonstrate that immunization with a recombinant protein Ag and GLA-SE also induces granzyme A expression in CD4 T cells and produces cytolytic cells that can be detected in vivo. Surprisingly, these in vivo CTLs were CD4 T cells, not CD8 T cells, and this cytolytic activity was not dependent on granzyme A/B or perforin. Unlike previously reported CD4 CTLs, the transcription factors Tbet and Eomes were not necessary for their development. CTL activity was also independent of the Fas ligand–Fas, TRAIL–DR5, and canonical death pathways, indicating a novel mechanism of CTL activity. Rather, the in vivo CD4 CTL activity induced by vaccination required T cell expression of CD154 (CD40L) and target cell expression of CD40. Thus, vaccination with a TLR4 agonist adjuvant induces CD4 CTLs, which kill through a previously unknown CD154-dependent mechanism.
Impacts of climate change on nutrient losses from the Pike River watershed of southern Québec
Authors: Gombault C. , Madramootoo C. A. , Michaud A. R. , Beaudin I. , Sottile M. F. , Chikhaoui M. , Ngwa F. F.
Published: August 2015

Gombault, C., Madramootoo, C. A., Michaud, A. R., Beaudin, I., Sottile, M. F., Chikhaoui, M. and Ngwa, F. F. 2015. Impacts of climate change on nutrient losses from the Pike River watershed of southern Québec. Can. J. Soil Sci. 95: 337–358. The impacts of climate change on water quality in the Pike River watershed, an important contributor of nutrient loads into the northern arm of Lake Champlain, were simulated for the time horizon 2041–2070. Four water quality scenarios were simulated using a calibrated version of the Soil and Water Assessment Tool (SWAT) customized to Québec agroclimatic conditions. Three of the scenarios were generated using climate data simulated with the Fourth-generation Canadian Regional Climate Model (CRCM4). The fourth scenario was generated using the climate simulated with the Arpege Regional Climate Model. Potential mean climate-induced changes in sediment, phosphorus, and nitrogen yield projected by these scenarios were then analyzed for the 2050 horizon. In addition, the impacts of the different sources of climate projection uncertainty were assessed by comparing climate model initial conditions, and climate model physical structure effects on the hydrochemical projections. Only one climate scenario projected a significant increase in mean annual total phosphorus [10 metrics tons (t) yr−1or 14%] and total nitrogen (260 t yr−1or 17%) loads. However, when shorter time spans (seasonal and monthly scales) were considered, several significant changes were detected, especially in winter. Sediment and nutrient loadings, in winter, were predicted to become three to four times higher than current levels. These increases were attributed to a greater vulnerability of soils to erosion in winter due to the decrease in the snowpack, early onset of spring snowmelt, a greater number of rainfall events, and snowmelt episodes caused by higher winter and spring temperatures.
Immunocompromised Travelers: Demographic Characteristics, Travel Destinations, and Pretravel Health Care from the U.S. Global TravEpiNet Consortium
Authors: Schwartz Brian S. , Rosen Jessica , Han Pauline V. , Hynes Noreen A. , Hagmann Stefan H. , Rao Sowmya R. , Jentes Emily S. , Ryan Edward T. , LaRocque Regina C. , _ _
Published: August 2015

An increasing number of immunocompromised individuals are pursuing international travel, and a better understanding of their international travel patterns and pretravel health care is needed. We evaluated the clinical features, itineraries, and pretravel health care of 486 immunocompromised international travelers seen at Global TravEpiNet sites from January 2009 to June 2012. We used bivariate analyses and logistic regressions using random intercept models to compare demographic and travel characteristics, vaccines administered, and medications prescribed for immunocompromised travelers versus 30,702 immunocompetent travelers. Immunocompromised travelers pursued itineraries that were largely similar to those of immunocompetent travelers, with nearly one-third of such travelers visiting countries with low human development indices. Biological agents, including tumor necrosis factor blockers, were commonly used immunosuppressive medications among immunocompromised travelers. A strong collaboration between travel-medicine specialists, primary care doctors, and specialist physicians is needed to prepare immunocompromised people for international travel. Incorporating routine questioning and planning regarding travel into the primary care visits of immunocompromised people may be useful.
A question driven socio-hydrological modeling process
Authors: Garcia M. , Portney K. , Islam S.
Published: August 2015

Abstract. Human and hydrological systems are coupled: human activity impacts the hydrological cycle and hydrological conditions can, but do not always, trigger changes in human systems. Traditional modeling approaches with no feedback between hydrological and human systems typically cannot offer insight into how different patterns of natural variability or human induced changes may propagate through this coupled system. Modeling of coupled human and hydrological systems, also called socio-hydrological systems, recognizes the potential for humans to transform hydrological systems and for hydrological conditions to influence human behavior. However, this coupling introduces new challenges and existing literature does not offer clear guidance regarding the choice of modeling structure, scope, and detail. A shared understanding of important processes within the field is often used to develop hydrological models, but there is no such consensus on the relevant processes in socio-hydrological systems. Here we present a question driven process to address these challenges. Such an approach allows modeling structure, scope, and detail to remain contingent and adaptive to the question context. We demonstrate its utility by exploring a question: what is the impact of reservoir operation policy on the reliability of water supply for a growing city? Our example model couples hydrological and human systems by linking the rate of demand decreases to the past reliability to compare standard operating policy (SOP) with hedging policy (HP). The model shows that reservoir storage acts both as a buffer for variability and as a delay triggering oscillations around a sustainable level of demand. HP reduces the threshold for action thereby decreasing the delay and the oscillation effect. As a result per capita demand decreases during periods of water stress are more frequent but less drastic and the additive effect of small adjustments decreases the tendency of the system to overshoot available supplies. This distinction between the two policies was not apparent using a traditional non-coupled model.
Towards a Model of Rhetorical Criticism of Metonymy in Chinese Media Texts
Authors: Li Ke , Li Shukang
Published: August 2015

Rhetorical criticism is a type of criticism with rhetorical phenomena as its object. In the context of western rhetoric, rhetorical criticism is usually viewed as a method to describe, explain and evaluate certain rhetorical phenomena or act. Metonymy, as a kind of rhetorical device in traditional rhetoric and a cognitive tool in cognitive linguistics, can be regarded as an object for criticism. Accordingly, an analysis of metonymy from the perspective of rhetorical criticism can disclose text builders’ rhetorical motive behind the linguistic use of metonymy. Moreover, it can reveal the ideological meaning of the text (a weak version of ideology) by analyzing and evaluating the terministic screen constructed by the metonymy, to achieve the purpose of rhetorical persuasion and build an “identification” between the addresser and addressee.
Estimación curva J en Nicaragua: Aplicación modelo Econométrico de rezagos distribuidos Almon
Authors: Morales Rivas Oliver David
Published: August 2015

El presente ensayo tiene como finalidad, evidenciar empíricamente la curva J y determinar el efecto de la devaluación del tipo de cambio en el saldo de la balanza comercial en Nicaragua. Para este propósito, se desarrolló un modelo econométrico, cimentado en los modelos de rezagos distribuidos “Almon” para series temporales. En correspondencia, este ensayo emplea la estructura de cálculo propuesta por Shirley Almon (1965), y sigue la propuesta de estimación mínimos cuadrado ordinario restringido implementado por Schmidt y Waud (1973), y Giles (1975). El resultado se puede afirmar la presencia de la curva J para la economía nicaragüense, cuyo efecto dura aproximadamente dos periodos, el impacto volumen se presenta en los trimestres uno, dos y tres después de generarse una devaluación en el tipo de cambio, finalizados los trimestres que comprenden el efecto volumen, se suscitan efectos negativos, muy significativos. En consecuencia, el modelo propuesto es idóneo para estimar la curva J en la economía nicaragüense y el tipo de cambio real sigue una distribución polinómica de cuarto grado y la política actual cambiara de deslizamiento de 5 por ciento anual, no ha tenido un efecto positivo en el saldo de la balanza comercial en el largo plazo.
Los procesos sociales desde la mirada holística del paradigma emergente y su historia en el desarrollo económico y social
Authors: López Zepeda Leonardo Francisco
Published: August 2015

El presente documento tiene como objetivo describir la problemática observada en los procesos sociales, en la orfandad y la lógica que manifiestan los ciudadanos y ciudadanas con respecto a los referentes de auto organización y la motivación para generar soluciones, sociales, comunales y económicas. El método utilizado en su realización es orden documental, con el cual se logran investigar todas las situaciones que están relacionadas a las carencias de verdaderos valores éticos y morales que unen a la comunidad y al eco ambiental y que involucran de manera total (holística) a todas las partes que componen el todo y como resultado nos refleja toda la problemática de la euro colonización del pensamiento en Latinoamérica y la incidencia que tiene en ella. En conclusión propone al holismo para terminar con la fragmentación que existe entre la comunidad, la sociedad y en la economía. Para lograr a través de este una conexión para llegar a un fin en común.
Competitividad de los Productos Agrícolas No Tradicionales 2009-2013
Authors: Cerda Ramírez Nathaly Virginia
Published: August 2015

El presente trabajo tiene como objetivo, determinar la ventaja relativa que presenta los productos agrícolas no tradicionales. El estudio es descriptivo y prospectivo, donde se evalúa un periodo de cinco años, las fuentes estadísticas implantadas dentro del estudio, se constituye por la estadística descriptiva haciendo uso de la concepción de índices comerciales que forman parte integral de la medición del nivel de competitividad con que cuentan los productos en el mediano plazo. El indicador, persigue un parámetro ilustrativo inherente de la dinámica comercial de la región Centroamericana. Los resultados del indicador, admiten la presencia de importantes flujos de intercambio, en base a la producción de Fruta fresca, dirigida en un 77.33% a Costa Rica. El nivel de competitividad del rubro de plátano, apuntala, un mayor dinamismo comercial (36%) con Honduras. Concluyentes en el desafío, del horizonte de oportunidades existentes, Nicaragua se posiciona como un mercado poco competitivo, carente del valor agregado y anexo de una reducida lista de cultivos.
Estructura racional o irracionalidad de la estructura universitaria ante interacciones en la Economía del Aprendizaje y la Transdisciplinariedad
Authors: Ramón López Mario
Published: August 2015

La universidad como organización e institución que captura, procesa, transmite y distribuye la información y el conocimiento debe adaptarse a la nueva forma de producción de conocimiento. La estructura universitaria está requiriendo un enfoque integral para analizar y reflexionar sobre las conexiones y procesos de retroalimentación con la sociedad y con las redes de actores locales para la producción de conocimiento y el aprendizaje. La contribución universitaria al proceso de innovación es una cuestión compleja que trascienden y ponen demandas sobre los profesores, investigadores y extensionistas para ir más allá de un pensamiento disciplinar.
Criterios para la toma de decisión de Inversiones
Authors: Canales Salinas Ricardo José
Published: August 2015

El presente ensayo tiene por finalidad mostrar la metodología de cálculo de algunas técnicas generalmente aceptados para evaluar los flujos financieros de proyectos de inversión. Se trata de un estudio teórico. Las principales técnicas utilizadas para la valoración de proyecto están: el valor actual neto, la tasa interna de retorno, el periodo de recuperación, tasa de rendimiento contable.
Servicios de salud a personas con discapacidad
Authors: González Pérez Yaritza Damaris
Published: August 2015

El objetivo del ensayo es elaborar un breve análisis de las condiciones y acceso a los servicios de salud de las personas con discapacidad. La metodología utilizada consistió en un proceso descriptivo de los servicios de salud de personas con discapacidad en el país, a partir de la información proporcionada por la Encuesta Nicaragüense para personas con discapacidad (ENDIS), realizada en el año 2003 por el Instituto Nacional de Estadística y Censos (INEC). Los resultados generados por la encuesta reflejan que la discapacidad en el país es de 10.3% de la población mayor de seis años de edad, 10.5% en las zonas urbanas y 10 % en las zonas rurales, reflejando que la discapacidad afecta más al sexo femenino en 11,3% que al masculino que presenta un 9,1%.
Tenencia de la tierra de acuerdo al IV CENAGRO de INIDE
Authors: Martínez Espinoza Ellieth Marina , Avellán Castellón Jessica Rebeca
Published: August 2015

Este ensayo muestra un análisis del comportamiento de la tendencia de la tierra en Nicaragua, utilizando el IV censo del CENAGRO, con la finalidad de explicar la situación de las formas de tenencia de nuestro país. Se diseñó un estudio en base a la encuesta, utilizando el programa SPSS mediante cálculos econométricos. Los datos de la encuesta se tomaron de una muestra de aproximadamente el 4% de los Sectores de Empadronamiento Agropecuario (SEA) de los departamentos y municipios. Se obtuvo una muestra total aproximada de 8,900 Explotaciones Agropecuarias. Las formas de tenencia resulta aún para nuestro país el talón de Aquiles de la seguridad productiva y ciudadana, representa un riesgo para cada poseedor de tierras o hasta para el estado mismo, sin embargo, la seguridad en la tenencia de la tierra es uno de los pilares de para lograr la productividad y crecimiento. Es indispensable establecer medidas que contribuyan al ordenamiento y legalización de propiedades fincas y otros. Es significativo implementar la participación social en este aspecto mediante acciones comunitarias, municipales, departamentales y nacionales.
Medición del Empleo Informal en el Marco de la Encuesta Continua de Hogares (ECH) 2012
Authors: Ramón Talavera Ernesto , Ortiz Rosales Sabrina Domitila
Published: August 2015

Este ensayo se realiza, con el fin de medir el empleo informal en Nicaragua a partir de la Encuesta Continua de Hogares IV trimestre 2012 del Instituto Nacional de Información de Desarrollo (INIDE). El procesamiento de Datos se centró en los métodos Cuantitativo y cualitativo, donde por Actividad económica, Área de residencia, Educación, y Estado civil, permitiendo conocer el nivel de empleo informal centrados por las distintas categorías (Variables explicativas) y que a través de este documento se analizaron. Y también permitió medir la informalidad del empleo. Los resultados del procesamiento de las variables, han mostrado que el empleo informal ha predominado en las variables analizadas, es decir, de las variables analizadas se caracteriza que el nivel de empleo estén en la informalidad, debido que a presentan limitaciones como: no hay suficientes puestos de trabajos y no están inscrito al seguro. En conclusión de toda la investigación permitió apreciar y conocer con exactitud el nivel de personas que están en la informalidad (Empleo Informal), y del sector (Economía Informal). Utilizando los posibles métodos que permitieron realizar nuestra investigación
Migración en Nicaragua 2004-2009
Authors: Padilla Velásquez Armando José , Gutiérrez Baltodano Eliezer Eliud
Published: August 2015

El ensayo pretende hacer una caracterización, causas y aspectos económicos que el ciudadano experimenta al decidir emigrar. El estudio es descriptivo y se basa en la Encuesta de Medición del Nivel de Vida del año 2009. Como resultado se obtuvo que las personas que emigran hacia otro país en busca de un mejor nivel de vida provienen de la zona urbana con un 65.7% de la muestra adquirida, donde la mayoría salen de la región del pacifico con un 44.1%, siendo los hombres los que predominan al emigrar con un 55.1% de la población. Es posible concluir que la migración nicaragüense se debe a las malas condiciones de supervivencia que vive la población de bajos ingresos, la falta de recursos, empleos informales, entre otros.
Indicadores de Dinamismo del Comercio Exterior de Nicaragua
Authors: Abarca Katherine , González Pérez Yaritza , Méndez Martínez Karen
Published: August 2015

El Objetivo de este ensayo es determinar el comportamiento del comercio exterior de Nicaragua para el periodo 2009-2013. Entre los indicadores de dinamismo comercial seleccionado están: Índices de apertura comercial, índices de intercambio comercial, índice de concentración/diversificación (IHH), Índice Grubel-Lloyd. También se escogieron los principales productos de exportación e importación, además de los principales 8 socios comerciales, para ello se utilizaron las estadísticas del Centro de trámite para las exportaciones (CETREX), Dirección general de aduana (DGA), Secretaria de integración económica centroamericana (SIECA), Banco central de Nicaragua (BCN), Ministerio de fomento, industria y comercio (MIFIC). Los hallazgos de la investigación reflejan que Nicaragua mantiene su déficit comercial porque no ha habido variación en la estructura de exportación e importación. Existe una concentración por destino de exportación y de diversificación en los productos, además el comercio sigue siendo de carácter inter-industrial, ya que vende materia prima y compra productos con mayor contenido industrial. En definitiva es indispensable seguir impulsando aquellas políticas públicas encaminadas a lograr mayores niveles de articulación productiva o sectorial que permita obtener mayor valor agregado, priorizando los sectores con mayor potencial productivo exportador y ampliando los socios comerciales.
Distorsión relativa de cuatro hidrocoloides irreversibles en modelos de piedra dental tipo IV
Authors: Arles Arauz Blas , López Mena Mercedes Elizabeth , De Jesús Hernández Cristian , López Toruño Ana Walkiria
Published: August 2015

El propósito de este estudio fue medir el grado de distorsión de 4 hidrocoloides irreversibles comparando su deformación en el plano (XY). Se diseñó un estudio experimental, efectuado en la facultad de Odontología de la UNAN – LEÓN donde se tomaron las impresiones por cada hidrocoloide seleccionado (Jeltrate, Max Print Cyan, Vival NF, Rite Dent), obteniendo una población de 20 modelos de estudio, 5 por cada marca de hidrocoloide irreversible. La medición de los modelos se realizó en una máquina de coordenadas (X, Y, Z) marca Mitutoyo-Japón que funciona con el programa Geopack 500 con un margen de error de 0.0001mm. No se presentaron diferencias estadísticamente significativas al aplicar el análisis ANOVA y TUKEY.
Desarrollo de un addin para Monodevelop 2.8 que permita la implementación del servicio de suscripciones de ASP .NET 2.0 empleando PostgreSQL 8.4 como gestor de base de datos
Authors: Espinoza Hernández Denis Leopoldo
Published: August 2015

MonoDevelop es un IDE libre y gratuito diseñado como alternativa a Visual Studio de Microsoft para el desarrollo de aplicaciones en C# y otros lenguajes soportados por .NET, que pesar de su amplio desarrollo aún adolece de algunas funcionalidades que Visual Studio ofrece. Entre las carencias que MonoDevelop tiene se encuentra el no poseer una interfaz que facilite la configuración y administración del servicios de suscripciones de ASP.NET a como lo tiene Visual Studio lo que obliga al usuario de MonoDevelop a realizar todas las configuraciones de forma manual. En este artículo se describen las etapas realizadas para el desarrollo de un addin (complemento) para MonoDevelop 2.8 que permite la implementación del servicio de suscripciones de ASP.NET 2.0 de manera similar a como se realiza en Visual Studio 2008. Como alternativa al gestor SQL Server 2008 de Microsoft empleado en la implementación del servicio de suscripciones desde Visual Studio 2008, se ha seleccionado PostgreSQL 8.4 como gestor de bases de datos para esta implementación por ser libre, gratuito y de alta compatibilidad con MonoDevelop 2.8.
Efectos de la inefciencia técnica ambiental en la calidad del agua del Estero Real: Caso Nicaragua
Authors: Aguilar Ariel José , Osorio Urtecho Katherinne del Rosario , Prado Olivares Mariela del Socorro , Carlos Alberto Zúniga González , Rafaela Dios Palomares , Sierra Figueredo Pablo , Quiros Madrigal Olman José
Published: August 2015

El presente estudio fue una aplicación empírica del modelo de frontera estocástica ambiental en panel de datos para medir la efficiencia técnica ambiental de la calidad del cuerpo de agua del Estero Real, Nicaragua [12] . El sector productivo de la Bioeconomía donde se aplica este enfoque es “Explotación de los recursos de la Biodiversidad”. El propósito del estudio es medir el nivel de inefficiencia técnica ambiental del cuerpo de agua del Estero Real. Se utilizó un modelo de frontera estocástica que considera la condición ambiental con parámetros físicos químicos y la actividad magnética planetaria. Los efectos de inefficiencia ambiental son asumidos para ser independientemente distribuidos como truncaciones de la distribución normal con varianza constante, pero con media, las cuales son una función lineal ambiental de variables observables. Los resultados evidencian que los efectos de inefficiencia ambiental son explicados por la inelasticidad de la actividad solar (-2.53) que redujeron la calidad del agua en un 89 % tipificándola como una calidad regular de acuerdo a Lynch y Poole [15].
Efecto de aplicación de flóculo sobre el crecimiento de camarones Litopenaeus vannamei en condiciones experimentales
Authors: Martínez González Evenor , Herrera Sirias Claudia , Sevilla Padilla Kevin
Published: August 2015

Los flóculos son bioalimentos importantes en la economía de cultivos acuícolas, presentan bajos costos y tienen bajo impacto ecológico. Este trabajo se realizó con el objetivo de diferenciar los efectos en el crecimiento de los camarones aplicando flóculos como suplemento alimenticio o sin flóculo. Para esto se midieron el Oxígeno disuelto, Temperatura, Salinidad, Crecimiento acumulado, Ritmos de crecimiento, cantidad de flóculo administrado. Como resultados se obtuvieron que el Oxígeno Disuelto varió entre 9.7 a 3.6 mg/l. La Temperatura se presentó entre los intervalos de 31.7 °C a 26.4 °C y La Salinidad entre 26 a 28°/ooS y la pila sin floculo entre 26 a 30 °/ooS. Los animales alimentados con complemento de flóculo crecieron 2g/30días y de 1,6g/30días los que no se aplicó flóculo, el Ritmo de Crecimiento presentó 0,38g/30días y de 0,30g/30días los que no se aplicó flóculo y una sobrevivencia de 98% para la pila con flóculo y 91% para la pila que no se aplicó flóculo. Se encontraron 0.8 a 1,2 millones flóculos/ml, la tendencia de las poblaciones de flóculo observado fue en incremento a lo largo del tiempo. Se obtuvieron diferencias significativas entre el crecimiento de los camarones en ambos tratamientos. (p<0.05).
Evaluación integral financiera, económica, social, ambiental y productividad del uso de bagazo de caña en la generación de energía Eléctrica en Nicaragua en ingenios no conectados a la red de energía eléctrica
Authors: Blanco Orozco Napoleón Vicente , Zúniga González Carlos Alberto , Arce Eduardo , Jaramillo Villanueva José Luis , Losilla Solano Luis , Colón García Adelfa Patricia
Published: August 2015

Se realizó una evaluación integral financiera, económica, social, de productividad y ambiental del empleo del recurso energético bagazo de caña en dos ingenios de Nicaragua que son CASUR y MONTELIMAR que generan energía eléctrica de autoconsumo empleando bagazo de caña. Al realizar esta investigación se concluyó que es una actividad bastante rentable desde el punto de vista financiero, tanto el ingenio CASUR como el Montelimar, lo que sitúa a ambos ingenios en una actividad con grandes beneficios económicos derivados del uso de este recurso energético renovable para la sociedad en general, aunque el ingenio CASUR presenta mayor beneficio. Desde el punto de vista del impacto social ambos ingenios fueron valorados también como bastante rentables, lo que demuestra que la actividad del uso de bagazo de caña para la generación de energía eléctrica tiene gran contribución social. Desde el punto de vista de la productividad total de los factores de producción empleados en la generación de energía eléctrica ambos ingenios pueden mejorar el ritmo de crecimiento de productividad.
Effects of Short-term Tillage of a Long-term No-Till Land on Available N and P in Two Contrasting Soil Types
Authors: Dyck Miles , Malhi Sukhdev. S. , Nyborg Marvin , Puurveen Dick
Published: August 2015

The effects of short-term (4 years) tillage (hereafter called reverse tillage [RT]) of land previously under long-term (29 or 30 years) no-till (NT), with straw management (straw removed [SRem] and straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha-1 in SRet, and 0 kg N ha-1 in SRem plots) were determined in autumn 2011 on ammonium-N, nitrate-N and extractable P in the 0-7.5, 7.5-15 and 15-20 cm soil layers at Breton (Gray Luvisol [Typic Cryoboralf] loam) and Ellerslie (Black Chernozem [Albic Argicryoll] loam), Alberta, Canada. There was no significant effect of RT and straw on ammonium-N, nitrate-N and extractable P in soil. Ammonium-N in soil increased significantly (but small) with N rate in many cases at both sites. Nitrate-N in soil increased with increasing N rate from 0 to 100 kg N ha-1 rate at Ellerslie, and up to 50 kg N ha-1 rate at Breton. Etractable P in soil decreased markedly with increasing N rate up to 100 kg N ha-1 at Breton and up to 50 kg N ha-1 at Ellerslie. In summary, increased N fertilizer rates were usually associated with decreased extractable P and increased nitrate-N in soil, but RT and straw had no effect on these nutrients in soil.
“The Fruits of Intellectual Labor”: International Student Views of Intellectual Property
Authors: Datig Ilka , Russell Beth
Published: August 2015

In this paper, we report on the results of a study conducted at New York University Abu Dhabi in the fall of 2013. Our goal in the study was to gain a global college student perspective on issues related to intellectual property, including copyright and plagiarism. We found that, contrary to popular opinion, most of our students have a solid understanding of the nature of intellectual property rights, as interpreted within the North American higher education community. In addition, the majority of our students view violations of intellectual property rights and norms, such as plagiarism, negatively.
Centriolar satellites assemble centrosomal microcephaly proteins to recruit CDK2 and promote centriole duplication
Authors: Kodani Andrew , Yu Timothy W , Johnson Jeffrey R , Jayaraman Divya , Johnson Tasha L , Al-Gazali Lihadh , Sztriha Lāszló , Partlow Jennifer N , Kim Hanjun , Krup Alexis L , Dammermann Alexander , Krogan Nevan J , Walsh Christopher A , Reiter Jeremy F
Published: August 2015

Primary microcephaly (MCPH) associated proteins CDK5RAP2, CEP152, WDR62 and CEP63 colocalize at the centrosome. We found that they interact to promote centriole duplication and form a hierarchy in which each is required to localize another to the centrosome, with CDK5RAP2 at the apex, and CEP152, WDR62 and CEP63 at sequentially lower positions. MCPH proteins interact with distinct centriolar satellite proteins; CDK5RAP2 interacts with SPAG5 and CEP72, CEP152 with CEP131, WDR62 with MOONRAKER, and CEP63 with CEP90 and CCDC14. These satellite proteins localize their cognate MCPH interactors to centrosomes and also promote centriole duplication. Consistent with a role for satellites in microcephaly, homozygous mutations in one satellite gene, CEP90, may cause MCPH. The satellite proteins, with the exception of CCDC14, and MCPH proteins promote centriole duplication by recruiting CDK2 to the centrosome. Thus, centriolar satellites build a MCPH complex critical for human neurodevelopment that promotes CDK2 centrosomal localization and centriole duplication.
Conformational change of Dishevelled plays a key regulatory role in the Wnt signaling pathways
Authors: Lee Ho-Jin , Shi De-Li , Zheng Jie J
Published: August 2015

The intracellular signaling molecule Dishevelled (Dvl) mediates canonical and non-canonical Wnt signaling via its PDZ domain. Different pathways diverge at this point by a mechanism that remains unclear. Here we show that the peptide-binding pocket of the Dvl PDZ domain can be occupied by Dvl's own highly conserved C-terminus, inducing a closed conformation. In Xenopus, Wnt-regulated convergent extension (CE) is readily affected by Dvl mutants unable to form the closed conformation than by wild-type Dvl. We also demonstrate that while Dvl cooperates with other Wnt pathway elements to activate canonical Wnt signaling, the open conformation of Dvl more effectively activates Jun N-terminal kinase (JNK). These results suggest that together with other players in the Wnt signaling pathway, the conformational change of Dvl regulates Wnt stimulated JNK activity in the non-canonical Wnt signaling.
Wild worm embryogenesis harbors ubiquitous polygenic modifier variation
Authors: Paaby Annalise B , White Amelia G , Riccardi David D , Gunsalus Kristin C , Piano Fabio , Rockman Matthew V
Published: August 2015

Embryogenesis is an essential and stereotypic process that nevertheless evolves among species. Its essentiality may favor the accumulation of cryptic genetic variation (CGV) that has no effect in the wild-type but that enhances or suppresses the effects of rare disruptions to gene function. Here, we adapted a classical modifier screen to interrogate the alleles segregating in natural populations of Caenorhabditis elegans: we induced gene knockdowns and used quantitative genetic methodology to examine how segregating variants modify the penetrance of embryonic lethality. Each perturbation revealed CGV, indicating that wild-type genomes harbor myriad genetic modifiers that may have little effect individually but which in aggregate can dramatically influence penetrance. Phenotypes were mediated by many modifiers, indicating high polygenicity, but the alleles tend to act very specifically, indicating low pleiotropy. Our findings demonstrate the extent of conditional functionality in complex trait architecture.
Collapse of a two‐dimensional brittle granular column: Implications for understanding dynamic rock fragmentation in a landslide
Authors: Langlois Vincent J. , Quiquerez Amélie , Allemand Pascal
Published: August 2015

We investigate numerically the failure, collapse, and flow of a two‐dimensional brittle granular column over a horizontal surface. In our discrete element simulations, we consider a vertical monolayer of spherical particles that are initially held together by tensile bonds, which can be irreversibly broken during the collapse. This leads to dynamic fragmentation within the material during the flow. Compared to what happens in the case of a noncohesive granular column, the deposit is much rougher, and the internal stratigraphic structure of the column is not preserved during the collapse. As has been observed in natural rockslides, we find that the deposit consists of large blocks laying on a lower layer of fine fragments. The influence of the aspect ratio of the column on the runout distance is the same as in the noncohesive case. Finally, we show that for a given aspect ratio of the column, the runout distance is higher when the deposit is highly fragmented, which confirms previous hypotheses proposed by Davies et al. (1999).
Automated detection and location of microseismicity at Mount St. Helens with a large‐N geophone array
Authors: Hansen Steven M. , Schmandt Brandon
Published: August 2015

In the summer of 2014 a dense array of 904 geophones was deployed at Mount St. Helens along the road and trail system within 15 km distance of the summit crater. The array recorded continuous data for approximately 2 weeks and presents an unprecedented seismic observation of an active volcano. A reverse‐time imaging method is applied to short‐term‐average over long‐term‐average time series data to automatically detect and locate microseismicity. These efforts resulted in an order of magnitude increase in earthquake detections over the normal monitoring operations of the Pacific Northwest Seismic Network. Earthquake locations resolve a narrow, ≤1 km wide, vertical lineament of seismicity which extends from the surface to 4 km depth directly beneath the summit crater. This feature is interpreted as a fracture network that acts as a conduit connecting an underlying magma chamber to the surface.
Hypervelocity dust impacts on the Wind spacecraft: Correlations between Ulysses and Wind interstellar dust detections
Authors: Wood S. R. , Malaspina David M. , Andersson Laila , Horanyi Mihaly
Published: August 2015

The Wind spacecraft is positioned just sunward of Earth at the first Lagrange point, while the Ulysses spacecraft orbits above and below the ecliptic plane crossing the ecliptic as far from the Sun as the orbit of Jupiter (∼5 AU). While Wind does not carry a dedicated dust detector, we demonstrate the ability of Wind electric field measurements to detect hypervelocity dust impacts through their impact plasma signatures. Interstellar dust (ISD) and interplanetary dust particles are differentiated based on a yearly modulation of the ISD flux. Measurements of ISD flux variation by Wind are found to be in good agreement with ISD flux variation measured by Ulysses. While measurements of the ISD flow direction through the Solar System determined by Wind could not be directly compared to those from Ulysses, strong variation in ISD flow direction was observed during similar time periods by both spacecraft.