bluuebunny/crossref_metadata_2025 huggingface dataset:
Zygostates alleniana (Orchidaceae: Epidendroideae: Cymbidieae: Oncidiinae): Floral structure related to pollinatio
Authors: Gómiz Natalia E. , Torretta Juan P. , Aliscioni Sandra S.
Published: December 2014

The genus Zygostates Lindl. (Orchidaceae) comprises about 20 species of small Neotropical epiphytic plants, represented in its southernmost limit by the species Z. alleniana. In this paper, we studied morphological and anatomical floral characteristics of this species related to pollination mechanism. We confirmed the presence of the unicellular trichomes on the base of the lip and side lobes secreting oil, constituting a trichomal elaiophore. The oil is deposited beneath the cuticle at the apex of the trichomes forming small blisters. The oil could represent a reward for the species Lophopedia nigrispinis, which would be a potential pollinator of Z. alleniana in a natural area within the geographic range of this plant species. Moreover, we prove that the reconfiguration of the pollinaruim is due to the dehydration of the walls cell. This reconfiguration could favor cross-pollination mechanism already described for other species of the family Orchidaceae. Finally, we discuss the floral characters present in Z. alleniana with closely related species.
Myxomycete diversity of the Patagonian Steppe and bordering areas in Argentina
Authors: Lado Carlos , Wrigley de Basanta Diana , Estrada-Torres Arturo , García-Carvajal Eva
Published: December 2014

Biodiversity surveys for myxomycetes (Amoebozoa) were carried out in three consecutive years (2009 to 2011) in the cold arid Patagonian Steppe, Argentina. The surveys, the first to cover such an extensive area in South America, form part of the Myxotropic project funded by the Spanish Government. Specimens were collected in 174 localities in four different provinces (Neuquén, Río Negro, Chubut and Santa Cruz), between 36° and 52° S latitudes. The most common types of substrate investigated were the dominant shrubs and grasses of the Patagonian steppe, and the Nothofagus forests, characteristic of the transition areas, but other plants such as small cacti and cushion plants were also included in the survey. A total of 133 different species and 5 varieties of myxomycetes representing 31 genera were identified in the 1134 specimens collected either in the field, or from moist chamber cultures prepared with samples of plant material obtained from the same collecting sites. The results include one species new to science, Perichaena nigra, and 17 species and two varieties that were previously unknown for either the Neotropics or South America, Badhamia armillata, Dianema mongolicum, Didymium annulisporum, D. leptotrychum, D. orthonemata, D. sturgisii, Echinostelium coelocephalum, Licea deplanata, L. nannengae, Macbrideola argentea, M. oblonga, Oligonema aurantium, Perichaena luteola, P. madagascariensis, Physarum luteolum, Protophysarum phloiogenum, Trichia contorta var. attenuata, T. contorta var. iowensis, T. erecta. An additional 19 species are new records for Argentina. These additions make Argentina the country in South America, at present, with the greatest number of myxomycetes catalogued having more than 50% of the species cited from the whole Neotropics. Diversity and biogeographic distribution of these organisms are discussed, and taxonomic comments on rare or unusual species are included and illustrated with photographs by LM and SEM. The results indicate that the myxomycetes, are widely distributed and are a normal component of Patagonian biota. Many of the substrates investigated were endemic plants from the region and are new substrates for a number of species of myxomycete. Differences between the variety of species in this area and others in Argentina and Chile, suggest a certain regional specialization of these organisms, the assemblage of which appear to depend on plant substrate species.
Mobile Technology as a Learning Tool
Authors: Ishtaiwa Fawzi
Published: December 2014

This study investigated students' actual use of mobile technology (MT) as a learning tool and identified their perceptions towards the effects of using MT on the learning process. It also examined the impact of students' academic major on their use and perceived effects of MT. The relationship between MT use and its effect on learning was explored as well. To this end, a quantitative study of professional diploma students' perceptions of MT was carried out. The results revealed that students use MT in a variety of ways, and they perceive it as primary valuable tools to supplement their learning. However, the nature of MT use is unpretentious in scope. The results also indicated that students' academic major significantly impacted their use and perceived effects of MT. In addition, significant correlation was found between the use and effects of MT.
Upper gastrointestinal bleeding after open heart surgery
Authors: Mahdi Aithoussa , Noureddine Atmani , Younes Moutakiallah , Mehdi Bamous , Abdessamad Abdou , Fouad Nya , Aniss Seghrouchni , Amal Wahid Fouad , Mohamed Drissi , Abdedaim Hatim Ghadbane , Youssef El Bekkali , Abdelatif Boulahya
Published: December 2014

Objective: The occurrence of digestive complications especially upper gastrointestinal bleeding (UGIB) has increased after cardiac surgery. The aim of this study was to determine the incidence of UGIB and identify the independent risk factors. Materials and Methods: We retrospectively analyzed data of 1077 patients undergoing cardiopulmonary bypass (CPB) from 1994 to 2012 The group of patients with UGIB (n
1 = 20) was compared with the population group (n
2 = 1057). Demographic characteristics, therapeutic management, endoscopic findings, and outcomes were analyzed. Through a regression analysis we identified independent risk factors of UGIB. Results: The mean age of the group n
1 was 58.2 ± 12.4 years and 50.18 ± 13.5 years in the group n
2. UGIB occurred about 13 ± 5.5 days after cardiac surgery. Gastroduodenal ulcer was the most common etiology of hemorrhage (n = 13, 65%). Renal insufficiency, previous gastric ulcer, increased lactate concentration during CPB, prolonged mechanical ventilation, use of vasopressor drug and pulmonary infection was likely contributing factors in UGIB. Conclusion: UGIB following open cardiac surgery is most frequently secondary to gastroduodenal ulceration. Many determinant factors of bleeding are incriminated. Surgeons must be aware of these factors to avoid fatal complications.
Air embolism: A rare complication of esophagogastroduodenoscopy!
Authors: Jhaveri Ajay B. , Shah Sharad C. , Shah Prasanna S.
Published: December 2014

Neurological complications of gastrointestinal endoscopy are extremely rare; cerebral air embolism has been described and can be severe and fatal. A high index of suspicion for an air embolism is a must in case of procedural or periprocedural cardiopulmonary instability and neurologic symptoms, particularly in patients with recognized risk factors. The diagnosis of an air embolism is often difficult and is complicated by the fact that air may be rapidly absorbed from the circulation. Simple maneuvers to decrease the impact of a potential air embolism include; stopping the procedure, administering high flow 100% oxygen, placing the patient in Trendelenburg and left lateral decubitus position, and discontinuing nitrous oxide. C T Scan and 2 D ECHO are important diagnostic tests.
Endovascular Treatment of Aneurysms of the Popliteal Artery by a Covered Endoprosthesis
Authors: Wissgott Christian , Lüdtke Christopher W. , Vieweg Hendryk , Scheer Fabian , Lichtenberg Michael , Schlöricke Erik , Andresen Reimer
Published: December 2014

Purpose

The current gold standard of popliteal artery aneurysm (PAA) treatment is saphenous vein bypass grafting. The aim of this retrospective single-center study is to investigate the safety and efficacy in the treatment of PAA by an endovascular implanted covered endoprosthesis.

Materials and Methods

Ten patients, mean age 64.6 (range, 52-78) years, with PAA were treated with an expanded Polytetrafluoroethylen (ePTFE)-covered stent graft (Viabahn®, W.L. Gore and Associates Inc, Flagstaff, AZ, USA). In median, 1.4 prostheses were implanted with a median length of 180 mm. Follow-up visits included determination of ankle-brachial index (ABI) and color-coded duplex sonography.

Results

The technical success rate was 100% (10/10). Clinically, there was an increase in ABI from 0.62 ± 0.17 to 0.91 ± 0.15 postinterventionally and to 0.89 ± 0.16 after an average follow-up of 24.7 months. During the follow-up period, 2 (20%) stent occlusions occurred; both of them were treated with a bypass graft.

Conclusion

The treatment of PAA with covered endoprosthesis is a safe and effective alternative to open surgical therapy, where open surgical therapy is contraindicated or patient refused open surgery.
Antioxidant Beverages: Green Tea Intake and Coronary Artery Disease
Authors: Ohmori Reiko , Kondo Kazuo , Momiyama Yukihiko
Published: December 2014

Coronary artery disease (CAD) is recognized as an inflammatory disease. In the present study, we investigated the effect of green tea consumption on plasma inflammatory markers and the association between green tea consumption and CAD. In 22 healthy volunteers, green tea consumption (7 cups/day) significantly decreased serum malondialdehyde-modified low-density lipoprotein (MDA-LDL) concentrations, whereas green tea consumption tended to decrease plasma C-reactive protein and interleukin (IL)-6 concentrations. In 725 patients undergoing coronary angiography, the percentage of patients drinking <1 cup/day of green tea was higher in patients with myocardial infarction (MI) than in CAD patients without MI and patients without CAD (29% vs. 15% and 18%, P < 0.01). Green tea consumption was found to be inversely associated with MI in Japanese patients. The protective effect of green tea against atherosclerosis is more likely to be because of the inhibitory effect of LDL oxidation than because of anti-inflammatory effect.
On the microwave optical properties of randomly oriented ice hydrometeors
Authors: Eriksson P. , Jamali M. , Mendrok J. , Buehler S. A.
Published: December 2014

Abstract. Microwave remote sensing is important for observing the mass of ice hydrometeors. One of the main error sources of microwave ice mass retrievals is that approximations around the shape of the particles are unavoidable. One common approach to represent particles of irregular shape is the soft particle approximation (SPA). We show that it is possible to define a SPA that mimics mean optical particles of available reference data over narrow frequency ranges, considering a single observation technique at the time, but SPA does not work in a broader context. Most critically, the required air fraction varies with frequency and application, as well as with particle size. In addition, the air fraction matching established density parameterisations results in far too soft particles, at least for frequencies above 90 GHz. That is, alternatives to SPA must be found. One alternative was recently presented by Geer and Baordo (2014). They used a sub-set of the same reference data and simply selected as "shape model" the particle type giving the best overall agreement with observations. We present a way to perform the same selection of a representative particle shape, but without involving assumptions on particle size distribution and actual ice mass contents. Only an assumption on the occurrence frequency of different particle shapes is still required. Our analysis leads to the same selection of representative shape as found by Geer and Baordo (2014). In addition, we show that the selected particle shape has the desired properties also at higher frequencies as well as for radar applications. Finally, we demonstrate that in this context the assumption on particle shape is likely less critical when using mass equivalent diameter to characterise particle size, compared to using maximum dimension, but a better understanding of the variability of size distributions is required to fully characterise the advantage. Further advancements on these subjects are presently difficult to achieve due to a lack of reference data. One main problem is that most available databases of precalculated optical properties assume completely random particle orientation, while for certain conditions a horizontal alignment is expected. In addition, the only database covering frequencies above 340 GHz has a poor representation of absorption as it is based on outdated refractive index data, as well as only covering particles having a maximum dimension below 2 mm and a single temperature.
Examining the everyday micro-economies of migrant detention in the United States
Authors: Conlon D. , Hiemstra N.
Published: December 2014

Abstract. Securitization of immigration, the rise of interior immigration policing, and forces of carceral privatization have occasioned a remarkable expansion of immigrant detention throughout the United States. Previous studies have drawn attention to the importance of the daily rates paid by the federal government to individual facilities in driving the emphasis on detention. This paper, in contrast, argues that tracing the political and economic geography of money inside detention facilities is also critical for understanding detention expansion and its consequences. We define the processes, mechanisms, and practices of generating profit above and beyond the "per-bed" daily rate as "internal micro-economies" of migrant detention. Drawing on an ongoing examination of migrant detention facilities in the greater New York City metropolitan area, we identify four micro-economies evident in detention facilities: the commissary systems, phone and other forms of communication, detainee labor, and detainee excursions outside detention. These economies show how detained migrants' needs and daily routines are tailored in ways that produce migrants as both captive consumers and laborers. Recognition of multiple micro-economies also highlights the fact that the numbers of individuals and entities invested in the incarceration of immigrants proliferate in tandem with the objectification of detainees. The paper further suggests that attending to relationships embedded in the inner workings of detention exposes economic links across carceral boundaries, rendering visible the porosity between government, private companies, and publics.
ORACLE (v1.0): module to simulate the organic aerosol composition and evolution in the atmosphere
Authors: Tsimpidi A. P. , Karydis V. A. , Pozzer A. , Pandis S. N. , Lelieveld J.
Published: December 2014

Abstract. A computationally efficient module to describe organic aerosol (OA) partitioning and chemical aging has been developed and implemented into the EMAC atmospheric chemistry–climate model. The model simulates the formation of secondary organic aerosol (SOA) from semivolatile (SVOCs), intermediate-volatility (IVOCs), and volatile organic compounds (VOCs). It distinguishes SVOCs from biomass burning and all other combustion sources using two surrogate species for each source category with an effective saturation concentration at 298 K of C* = 0.1 and 10 μg m−3. Two additional surrogate species with C* = 103 and 105 μg m−3 are used for the IVOCs emitted by the above source categories. Gas-phase photochemical reactions that change the volatility of the organics are taken into account. The oxidation products (SOA-sv, SOA-iv, and SOA-v) of each group of precursors (SVOCs, IVOCs, and VOCs) are simulated separately to keep track of their origin. ORACLE efficiently describes the OA composition and evolution in the atmosphere and can be used to (i) estimate the relative contributions of SOA and primary organic aerosol (POA) to total OA, (ii) determine how SOA concentrations are affected by biogenic and anthropogenic emissions, and (iii) evaluate the effects of photochemical aging and long-range transport on the OA budget. We estimate that the global average near-surface OA concentration is 1.5 μg m−3 and consists of 7% POA from fuel combustion, 11% POA from biomass burning, 2% SOA-sv from fuel combustion, 3% SOA-sv from biomass burning, 15% SOA-iv from fuel combustion, 28% SOA-iv from biomass burning, 19% biogenic SOA-v, and 15% anthropogenic SOA-v. The modeled tropospheric burden of OA components is 0.23 Tg POA, 0.16 Tg SOA-sv, 1.41 Tg SOA-iv, and 1.2 Tg SOA-v.
The hydrological regime of a forested tropical Andean catchment
Authors: Clark K. E. , Torres M. A. , West A. J. , Hilton R. G. , New M. , Horwath A. B. , Fisher J. B. , Rapp J. M. , Robles Caceres A. , Malhi Y.
Published: December 2014

Abstract. The hydrology of tropical mountain catchments plays a central role in ecological function, geochemical and biogeochemical cycles, erosion and sediment production, and water supply in globally important environments. There have been few studies quantifying the seasonal and annual water budgets in the montane tropics, particularly in cloud forests. We investigated the water balance and hydrologic regime of the Kosñipata catchment (basin area: 164.4 km2) over the period 2010–2011. The catchment spans over 2500 m in elevation in the eastern Peruvian Andes and is dominated by tropical montane cloud forest with some high-elevation puna grasslands. Catchment-wide rainfall was 3112 ± 414 mm yr−1, calculated by calibrating Tropical Rainfall Measuring Mission (TRMM) 3B43 rainfall with rainfall data from nine meteorological stations in the catchment. Cloud water input to streamflow was 316 ± 116 mm yr−1 (9.2% of total inputs), calculated from an isotopic mixing model using deuterium excess (Dxs) and δD of waters. Field streamflow was measured in 2010 by recording height and calibrating to discharge. River run-off was estimated to be 2796 ± 126 mm yr−1. Actual evapotranspiration (AET) was 688 ± 138 mm yr−1, determined using the Priestley and Taylor–Jet Propulsion Laboratory (PT-JPL) model. The overall water budget was balanced within 1.6 ± 13.7%. Relationships between monthly rainfall and river run-off follow an anticlockwise hysteresis through the year, with a persistence of high run-off after the end of the wet season. The size of the soil and shallow groundwater reservoir is most likely insufficient to explain sustained dry-season flow. Thus, the observed hysteresis in rainfall–run-off relationships is best explained by sustained groundwater flow in the dry season, which is consistent with the water isotope results that suggest persistent wet-season sources to streamflow throughout the year. These results demonstrate the importance of transient groundwater storage in stabilising the annual hydrograph in this region of the Andes.
Active-layer thermal monitoring on the Fildes Peninsula, King George Island, maritime Antarctica
Authors: Michel R. F. M. , Schaefer C. E. G. R. , Simas F. M. B. , Francelino M. R. , Fernandes-Filho E. I. , Lyra G. B. , Bockheim J. G.
Published: December 2014

Abstract. International attention to climate change phenomena has grown in the last decade; the active layer and permafrost are of great importance in understanding processes and future trends due to their role in energy flux regulation. The objective of this paper is to present active-layer temperature data for one Circumpolar Active Layer Monitoring South hemisphere (CALM-S) site located on the Fildes Peninsula, King George Island, maritime Antarctica over an 57-month period (2008–2012). The monitoring site was installed during the summer of 2008 and consists of thermistors (accuracy of ±0.2 °C), arranged vertically with probes at different depths, recording data at hourly intervals in a high-capacity data logger. A series of statistical analyses was performed to describe the soil temperature time series, including a linear fit in order to identify global trends, and a series of autoregressive integrated moving average (ARIMA) models was tested in order to define the best fit for the data. The affects of weather on the thermal regime of the active layer have been identified, providing insights into the influence of climate change on permafrost. The active-layer thermal regime in the studied period was typical of periglacial environments, with extreme variation in surface during the summer resulting in frequent freeze and thaw cycles. The active-layer thickness (ALT) over the studied period shows a degree of variability related to different annual weather conditions, reaching a maximum of 117.5 cm in 2009. The ARIMA model could describe the data adequately and is an important tool for more conclusive analysis and predictions when longer data sets are available. Despite the variability when comparing temperature readings and ACT over the studied period, no trend can be identified.
Adsorption, desorption and fractionation of As(V) on untreated and mussel shell-treated granitic material
Authors: Seco-Reigosa N. , Cutillas-Barreiro L. , Nóvoa-Muñoz J. C. , Arias-Estévez M. , Álvarez-Rodríguez E. , Fernández-Sanjurjo M. J. , Núñez-Delgado A.
Published: December 2014

Abstract. As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell, and granitic material amended with 12 and 24 t ha−1 fine shell, investigating the effect of different As(V) concentrations and different pH, as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the un-amended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always < 19% when the highest As(V) concentration (100 mg L−1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH < 6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreasing as pH increased. Desorption varying pH was always < 26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). Globally, the granitic material did not show high As(V) retention capacity, which implies risks of water pollution and transfer to the food chain; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.
INFLUENCE OF MODIFIED NATURAL RUBBER ON PROPERTIES OF NATURAL RUBBER–CARBON NANOTUBE COMPOSITES
Authors: Nakaramontri Yeampon , Nakason Charoen , Kummerlöwe Claudia , Vennemann Norbert
Published: December 2014

Carbon nanotube (CNT)–filled natural rubber (NR) composites were prepared by using an internal mixer and a two-roll mill. Various types of NR, including unmodified NR, epoxidized NR (ENR), and maleated NR (MNR), were used. The chemical reactions between rubber molecules and functional groups on the CNT surface were characterized by attenuated total reflection Fourier transform infrared spectroscopy. Cure characteristics, tensile properties, relaxation behavior, and electrical conductivity of the various gum rubbers and the CNT-filled rubber composites were investigated. It was found that the addition of CNTs significantly affected the composite properties. This is due not only to the excellent properties of the CNT itself but also to the physical and chemical interactions between modified rubber molecules and CNT surfaces. On comparison between the three types of NR, it was observed that the ENR-CNT composite showed the highest values of delta torque, tensile strength, and initial relaxation modulus. This confirms the homogeneous distribution of CNT particles in the ENR matrix, which in turn resulted from enhanced interactions of functional groups on CNT surfaces and epoxide groups in ENR molecules. Furthermore, electrical conductivity as a function of CNT content was examined to estimate the electrical percolation threshold value and to determine the state of dispersion of CNTs.
The Anti-Counterfeiting Trade Agreement and European Civil Society: A Case Study on Networked Advocacy
Authors: Losey James
Published: December 2014

Why was the European Anti-Counterfeiting Trade Agreement (ACTA), initially expected to be easily approved, ultimately rejected? Losey examines the role of civil society organizations in influencing this outcome. He describes how a small core group of national and transnational civil society organizations, supported by a range of communications technologies, played critical roles at different times, often acting more as network nodes than as traditional leaders. They successfully disrupted the ACTA negotiation process, which was seen as an attempt to push previously rejected provisions into law through a different avenue. This article documents the advocacy process beyond the more visible uses of digital media by social movements, and analyzes the less visible networks of civil society organizations in information policy debates.
Blast from the Past? A Comparative Analysis of Broadcast Licensing in the Digital Era
Authors: Schweizer Corinne , Puppis Manuel , Künzler Matthias , Studer Samuel
Published: December 2014

The advent of new broadcasting technologies has eliminated spectrum scarcity as a constraint on broadcasting, and with it one of the justifications for broadcast licensing. Have nations moved away from licensing as a form of regulation of their broadcasting sectors? And concomitantly, is there less opportunity to use licensing as a means of promoting the public interest in broadcasting? The authors address these questions through a comparative study of licensing requirements for terrestrial broadcasting and other forms of television and radio distribution in 18 Western nations.
Participatory Transparency in Social Media Governance: Combining Two Good Practices
Authors: Dreyer Stephan , Ziebarth Lennart
Published: December 2014

Can the Terms of Policies of social media platforms be made more comprehensible, transparent, and consumer-friendly? Dreyer and Ziebarth suggest that “participatory transparency,” based in the community of users, can help overcome contractual complexity and legal jargon while increasing user awareness. They recommend the use of autonomous bodies of third-party users to crowd-source platform-specific suggestions for improvements, and to translate terms and provisions into practical pointers. Implementation may be slow because platform providers may resist this approach, but the authors argue that the process has many benefits for the providers as well.
Drama as Philosophical Genre
Authors: Wahman Jessica
Published: December 2014

This article argues that theater can make a meaningful contribution to pluralist philosophy. As a performed narrative involving multiple perspectives, drama can illuminate the complexity and legitimacy of a plurality of theoretical commitments, whereas direct argumentation must weaken the opposition by putting it in a less compelling light. Dramatic performance can maximize philosophy's talent for questioning by conveying the rich possibilities and tensions among conflicting and contextually situated points of view without ultimately taking a definitive stance.
A Wound and a Prayer
Authors: MacKendrick Karmen
Published: December 2014

The focus of philosophical interest has shifted for decades between language and body, which are often seen as irreducibly opposed. There are some images or figures, however, that can be understood as intersections or hybrids of the two. The wound works this way in theological discourse, serving both as a devotional image and as a prayerful language.
Presentación No.34 2014
Authors: Editora La
Published: December 2014

DOI: http://doi.dx.org/10.5377/paradigma.v21i34.1691
Acción docente en situaciones de aprendizaje conceptual
Authors: Martínez Ramón , Arrieta Xiomara , Riveros Víctor
Published: December 2014

Los estudiantes de ciencias experimentales evidencian una escasez de conocimientos científicos previos a las actividades de las clases teóricas, resolución de problemas y de prácticas de laboratorio, que revelan aprendizajes mecánicos de los procesos aplicados, sin argumentaciones fundamentadas que den respuesta a situaciones problemáticas que se les presentan. Ante esta situación, la acción docente para enfrentar esta problemática es un reto impostergable. El objetivo de esta investigación es diseñar una estrategia de acción docente que promueva el aprendizaje significativo de conceptos científicos en el contexto del aula universitaria. La metodología es documental descriptiva. La estrategia, apoyada en la teoría de los campos conceptuales, integra éste con el aprendizaje como investigación científica dirigida, el estudio de la interacción en el aula y el aprendizaje significativo, conducente a una enseñanza eficaz de la conceptualización de lo real científico. DOI: http://doi.dx.org/10.5377/paradigma.v21i34.1694  - Revista de Investigación Educativa. Año 21. No. 34: 81-110
Incorporación de la literatura en un programa lectura del idioma inglés para desarrollar la competencia de escritura: Instituto Blanca Adriana Ponce Ponce de Tegucigalpa
Authors: Chávez Suazo Clara Elizabeth , Zelaya Matamoros Jenny Margoth
Published: December 2014

Esta es una visión general acerca de como la literatura ha sido incorporada en un programa de la enseñanza del inglés como lengua extranjera. Además de esto a través de esta propuesta se mostró la aplicación de una nueva metodología usando la literatura como una herramienta para desarrollar la competencia de escritura en el idioma inglés. Esta metodología consistió en escribir comentarios en el diario del alumno y hacer lectura intensiva usando mapas conceptuales para desarrollar la escritura. También la enseñanza del inglés en un colegio público fue un aspecto que se tomó en cuenta porque este estudio fue hecho en un colegio de Tegucigalpa, Honduras. Además de esto este fue un estudio de Investigación acción por eso los instrumentos y los procesos se basaron en lo que investigación acción sugiere para hacer un estudio educacional. Tres instrumentos fueron aplicados en este estudio: un test de suficiencia (placement test), una entrevista y un cuestionario. El resultado del desarrollo de la competencia escrita fue evidente en las diferentes asignaciones escritas dadas a los estudiantes. DOI: http://doi.dx.org/10.5377/paradigma.v21i34.1695  - Revista de Investigación Educativa. Año 21. No. 34: 111-132
Sistematización del pilotaje de la homologación curricular en el tercer ciclo de educación básica: la perspectiva de los actores
Authors: Xiomara Castro Jenny , Suyapa Padilla Zoila
Published: December 2014

En el marco del trabajo del Proyecto de Homologación del Tercer Ciclo, la UPNFM a través del INIEES, a solicitud de la Secretaría de Educación con apoyo del BID y GIZ-GOPA, desarrolla el proyecto de Sistematización del cambio curricular en cinco centros educativos de diferentes modalidades de enseñanza. Para Martinic (1984) la sistematización de experiencias es un proceso de reflexión, que permite ordenar u organizar procesos, resultados de un proyecto, buscando en esa dinámica las dimensiones que puedan explicar el curso que asumió el trabajo que se hizo. Se considera como un proceso de aprendizaje, que comparte con la investigación y la evaluación algunos procedimientos metodológicos básicos. Bajo el supuesto, como nos señala Fullan (1993), que los docentes pueden generar nuevos saberes como producto del cambio curricular. DOI: http://doi.dx.org/10.5377/paradigma.v21i34.1698  - Revista de Investigación Educativa. Año 21. No. 34: 189-224
L’intensité de variation du taux de plus-value dans la problématique marxienne de la dynamique du taux de profit général
Authors: Clain Olivier
Published: December 2014

Dans ses recherches successives relatives à la dynamique du taux de profit, Marx identifie la croissance de la différence entre les taux de plus-value et de profit comme la condition la plus générale de la baisse du second en dépit de la hausse du taux de plus-value général. Il a cherché avec acharnement à formuler la loi de son évolution. Même s’il n’y est pas parvenu, il a mis partiellement à jour sa dépendance à l’endroit de l’intensité de variation du taux de plus-value. Or dès qu’on traite le taux de profit comme système dynamique discret, la prise en compte de cette intensité s’impose et permet de formuler les conditions les plus générales de l’existence de la baisse et d’une tendance nécessaire à la baisse du taux de profit. Elle nous permet aussi bien de formuler les lois élémentaires qui gouvernent les intensités de variation de la composition, de l’accumulation, de la différence simple entre les deux taux et de leurs relations.
A Broken System of Self‐Regulation of Privacy Online? Surveillance, Control, and Limits of User Features in U.S. Websites
Authors: Park Yong Jin
Published: December 2014

This article examines user control of privacy online as indicated by functional features of commercial websites. While prior studies have focused on what's written in privacy policy statements, systematic attention on the interactive aspects of the Web have been scant. This analysis, based on a sample of 398 commercial sites in the United States, shows that the more popular sites did not necessarily provide better privacy control features for users than sites that were randomly selected. In addition, there was no clear relationship between website characteristics and the functional features of privacy control. Implications are discussed for the current status of online privacy policy in the United States and the European Union.
What Potential for YouTube as a Policy Deliberation Tool? Commenter Reactions to Videos About the Keystone XL Oil Pipeline
Authors: Deschamps Ryan
Published: December 2014

Social network sites have been proposed to influence the way interest groups and citizens interact on various policy topics. User reaction to information received on YouTube can be partially observed by examining comments provided as part of the interface. Using content analysis, this article explores the way YouTube users interact with information provided by media, interest groups, and other groups through user comments. While a large number of comments are found to be ad hominem or off‐topic, in general, user comments on the controversial Canada–U.S. Keystone XL oil pipeline cover collectively the main topic areas found in the December 2, 2013 U.S. Congressional Research Service study of the issues. User comments also reflect a preferential network structure where the existence of a comment makes it more likely that someone will reply to commenters rather than the video itself. The article concludes with some comments on the potential of YouTube as a policy deliberation tool.
Titan's interaction with the supersonic solar wind
Authors: Bertucci C. , Hamilton D. C. , Kurth W. S. , Hospodarsky G. , Mitchell D. , Sergis N. , Edberg N. J. T. , Dougherty M. K.
Published: December 2014

After 9 years in the Saturn system, the Cassini spacecraft finally observed Titan in the supersonic and super‐Alfvénic solar wind. These unique observations reveal that Titan's interaction with the solar wind is in many ways similar to unmagnetized planets Mars and Venus and active comets in spite of the differences in the properties of the solar plasma in the outer solar system. In particular, Cassini detected a collisionless, supercritical bow shock and a well‐defined induced magnetosphere filled with mass‐loaded interplanetary magnetic field lines, which drape around Titan's ionosphere. Although the flyby altitude may not allow the detection of an ionopause, Cassini reports enhancements of plasma density compatible with plasma clouds or streamers in the flanks of its induced magnetosphere or due to an expansion of the induced magnetosphere. Because of the upstream conditions, these observations may be also relevant to other bodies in the outer solar system such as Pluto, where kinetic processes are expected to dominate.
Linkages of remote sea surface temperatures and Atlantic tropical cyclone activity mediated by the African monsoon
Authors: Taraphdar Sourav , Leung L. Ruby , Hagos Samson
Published: December 2014

Warm sea surface temperatures (SSTs) in North Atlantic and Mediterranean (NAMED) can influence tropical cyclone (TC) activity in the tropical East Atlantic by modulating summer convection over western Africa. Analysis of 30 years of observations demonstrates that warm NAMED SST is linked to a strengthening of the Saharan heat low and enhancement of moisture and moist static energy in the lower troposphere over West Africa, which favors a northward displacement of the monsoonal front. These processes also lead to a northward shift of the African easterly jet that introduces an anomalous positive vorticity from western Africa to the main development region (50°W–20°E; 10°N–20°N) of Atlantic TCs. By modulating multiple African monsoon processes, NAMED SST explains comparable and approximately one third of the interannual variability of Atlantic TC frequency as that explained by local wind shear and local SST, respectively, which are known key factors that influence Atlantic TC development.
Externally driven plasmaspheric ULF waves observed by the Van Allen Probes
Authors: Takahashi Kazue , Denton Richard E. , Kurth William , Kletzing Craig , Wygant John , Bonnell John , Dai Lei , Min Kyungguk , Smith Charles W. , MacDowall Robert
Published: December 2014

We analyze data acquired by the Van Allen Probes on 8 November 2012, during a period of extended low geomagnetic activity, to gain new insight into plasmaspheric ultralow frequency (ULF) waves. The waves exhibited strong spectral power in the 5–40 mHz band and included multiharmonic toroidal waves visible up to the eleventh harmonic, unprecedented in the plasmasphere. During this wave activity, the interplanetary magnetic field cone angle was small, suggesting that the waves were driven by broadband compressional ULF waves originating in the foreshock region. This source mechanism is supported by the tailward propagation of the compressional magnetic field perturbations at a phase velocity of a few hundred kilometers per second that is determined by the cross‐phase analysis of data from the two spacecraft. We also find that the coherence and phase delay of the azimuthal components of the magnetic field from the two spacecraft strongly depend on the radial separation of the spacecraft and attribute this feature to field line resonance effects. Finally, using the observed toroidal wave frequencies, we estimate the plasma mass density for L = 2.6–5.8. By comparing the mass density with the electron number density that is estimated from the spectrum of plasma waves, we infer that the plasma was dominated by H+ ions and was distributed uniformly along the magnetic field lines. The electron density is higher than the prediction of saturated plasmasphere models, and this “super saturated” plasmasphere and the uniform ion distribution are consistent with the low geomagnetic activity that prevailed.
Liquid‐Crystalline Electrolytes for Lithium‐Ion Batteries: Ordered Assemblies of a Mesogen‐Containing Carbonate and a Lithium Salt
Authors: Sakuda Junji , Hosono Eiji , Yoshio Masafumi , Ichikawa Takahiro , Matsumoto Takuro , Ohno Hiroyuki , Zhou Haoshen , Kato Takashi
Published: December 2014

Thermotropic liquid‐crystalline (LC) electrolytes for lithium‐ion batteries are developed for the first time. A rod‐like LC molecule having a cyclic carbonate moiety is used to form self‐assembled two‐dimensional ion‐conductive pathways with lithium salts. Electrochemical and thermal stability, and efficient ionic conduction is achieved for the liquid crystal. The mixture of the carbonate derivative and lithium bis(trifluoromethylsulfonyl)imide is successfully applied as an electrolyte in lithium‐ion batteries. Reversible charge–discharge for both positive and negative electrodes is observed for the lithium‐ion batteries composed of the LC electrolyte.
An Advanced Nitrogen‐Doped Graphene/Cobalt‐Embedded Porous Carbon Polyhedron Hybrid for Efficient Catalysis of Oxygen Reduction and Water Splitting
Authors: Hou Yang , Wen Zhenhai , Cui Shumao , Ci Suqin , Mao Shun , Chen Junhong
Published: December 2014

A novel hybrid electrocatalyst consisting of nitrogen‐doped graphene/cobalt‐embedded porous carbon polyhedron (N/Co‐doped PCP//NRGO) is prepared through simple pyrolysis of graphene oxide‐supported cobalt‐based zeolitic imidazolate‐frameworks. Remarkable features of the porous carbon structure, N/Co‐doping effect, introduction of NRGO, and good contact between N/Co‐doped PCP and NRGO result in a high catalytic efficiency. The hybrid shows excellent electrocatalytic activities and kinetics for oxygen reduction reaction in basic media, which compares favorably with those of the Pt/C catalyst, together with superior durability, a four‐electron pathway, and excellent methanol tolerance. The hybrid also exhibits superior performance for hydrogen evolution reaction, offering a low onset overpotential of 58 mV and a stable current density of 10 mA cm−2 at 229 mV in acid media, as well as good catalytic performance for oxygen evolution reaction (a small overpotential of 1.66 V for 10 mA cm−2 current density). The dual‐active‐site mechanism originating from synergic effects between N/Co‐doped PCP and NRGO is responsible for the excellent performance of the hybrid. This development offers an attractive catalyst material for large‐scale fuel cells and water splitting technologies.
Rheological and Viscoelastic Properties of Novel Sunflower Oil‐Span 40‐Biopolymer–Based Bigels and Their Role as a Functional Material in the Delivery of Antimicrobial Agents
Authors: Behera B. , Dey S. , Sharma V. , Pal K.
Published: December 2014

In this paper, the mechanical properties of sunflower oil‐span 40‐natural gum bigels were evaluated. The bigels were prepared by mixing the oleogels of sunflower oil‐span 40 and the hydrogels of natural gums. The types of molecular interactions occurring were studied by FTIR spectroscopy. Rheological and textural behavior of the bigels was determined by dynamic rheological studies and a static mechanical tester. The Peleg and Normand equation was used to determine the viscoelastic behavior of the bigels. The efficiency of these food‐grade bigels as carriers for the delivery of metronidazole (model drug) was studied. In vitro drug release was carried out under physiological conditions. The antimicrobial efficiency of the bigels was checked against Escherichia coli. FTIR studies showed hydrogen bonding within the bigels as the major molecular interaction. The rheological and mechanical studies showed that the bigels exhibited pseudoplastic flow behavior. The bigels were viscoelastic in nature. Diffusion mediated drug release was observed. All the bigels showed an equal antimicrobial efficacy in comparison to the available marketed formulation.
Ultrafast Charge Generation Pathways in Photovoltaic Blends Based on Novel Star‐Shaped Conjugated Molecules
Authors: Kozlov Oleg V. , Luponosov Yuriy N. , Ponomarenko Sergei A. , Kausch‐Busies Nina , Paraschuk Dmitry Yu , Olivier Yoann , Beljonne David , Cornil Jérôme , Pshenichnikov Maxim S.
Published: December 2014

The quest for new materials is one of the main factors propelling recent advances in organic photovoltaics. Star‐shaped small molecules (SSMs) have been proven promising candidates as perspective donor material due to the increase in numbers of excitation pathways caused by the degeneracy of the lowest unoccupied molecular orbital (LUMO) level. In order to unravel the pathways of the initial photon‐to‐charge conversion, the photovoltaic blends based on three different SSMs with a generic structure of N(phenylene‐nthiophene‐dicyanovinyl‐alkyl)3 (n = 1–3), and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) acceptor are investigated by ultrafast photoinduced absorption spectroscopy assisted by density functional theory calculations. It is shown that both electron transfer from SSMs to PC71BM and hole transfer from PC71BM to SSMs are equally significant for generation of long‐lived charges. In contrast, intramolecular (intra‐SSM) charge separation results in geminate recombination and therefore constitutes a loss channel. Overall, up to 60% of long‐lived separated charges are generated at the optimal PC71BM concentrations. The obtained results suggest that further improvement of the SSM‐based solar cells is feasible via optimization of blend morphology and by suppressing the intra‐SSM recombination channel.
Monitoring and Targeting the Initial Dimerization Stage of Amyloid Self‐Assembly
Authors: Bram Yaron , Lampel Ayala , Shaltiel‐Karyo Ronit , Ezer Anat , Scherzer‐Attali Roni , Segal Daniel , Gazit Ehud
Published: December 2014

Amyloid deposits are pathological hallmark of a large group of human degenerative disorders of unrelated etiologies. While accumulating evidence suggests that early oligomers may account for tissue degeneration, most detection tools do not allow the monitoring of early association events. Here we exploit bimolecular fluorescence complementation analysis to detect and quantify the dimerization of three major amyloidogenic polypeptides; islet amyloid polypeptide, β‐amyloid and α‐synuclein. The constructed systems provided direct visualization of protein‐protein interactions in which only assembled dimers display strong fluorescent signal. Potential inhibitors that interfere with the initial intermolecular interactions of islet amyloid polypeptide were further identified using this system. Moreover, the identified compounds were able to inhibit the aggregation and cytotoxicity of islet amyloid polypeptide, demonstrating the importance of targeting amyloid dimer formation for future drug development.
Ligand Transformations and Efficient Proton/Water Reduction with Cobalt Catalysts Based on Pentadentate Pyridine‐Rich Environments
Authors: Basu Debashis , Mazumder Shivnath , Shi Xuetao , Baydoun Habib , Niklas Jens , Poluektov Oleg , Schlegel H. Bernhard , Verani Cláudio N.
Published: December 2014

A series of cobalt complexes with pentadentate pyridine‐rich ligands is studied. An initial CoII amine complex 1 is prone to aerial oxidation yielding a CoIII imine complex 2 that is further converted into an amide complex 4 in presence of adventitious water. Introduction of an N‐methyl protecting group to the ligand inhibits this oxidation and gives rise to the CoII species 5. Both the CoIII 4 and CoII 5 show electrocatalytic H2 generation in weakly acidic media as well as in water. Mechanisms of catalysis seem to involve the protonation of a CoIIH species generated in situ.
Gold‐Catalyzed Intermolecular Anti‐Markovnikov Hydroamination of Alkylidenecyclopropanes
Authors: Timmerman Jacob C. , Robertson Bradley D. , Widenhoefer Ross A.
Published: December 2014

The cationic gold phosphine complex [{PCy2(o‐biphenyl)}Au(NCMe)]+SbF6− (Cy=cyclohexyl) catalyzes the intermolecular, anti‐Markovnikov hydroamination reaction of monosubstituted and cis‐ and trans‐disubstituted alkylidenecyclopropanes (ACPs) with imidazolidin‐2‐ones and other nucleophiles. This reaction forms 1‐cyclopropyl alkylamine derivatives in high yield and with high regio‐ and diastereoselectivity. NMR spectroscopic analysis of gold π‐ACP complexes and control experiments point to the sp hybridization of the ACP internal alkene carbon atom as controlling the regiochemistry of the ACP hydroamination reaction.