bluuebunny/crossref_metadata_2025 huggingface dataset:
Technological pedagogical content knowledge in South African mathematics classrooms: A secondary analysis of SITES 2006 data
Authors: Leendertz Verona , Blignaut A. Seugnet , Nieuwoudt Hercules D. , Els Christo J. , Ellis Suria M.
Published: December 2013

This article reports on a secondary data analysis conducted on the South African mathematics teachers’ dataset of the Second Information Technology in Education Study (SITES 2006). The sample consisted of a stratified sample of 640 mathematics teachers from 504 randomly selected computer-using and non–computer-using schools that completed the SITES 2006 teachers’ questionnaire, which investigated their pedagogical use of Information Communication Technology (ICT). The purpose of the current investigation was to investigate the level of Technological Pedagogical Content Knowledge (TPACK) of mathematics teachers, and how TPACK attributes contribute towards more effective Grade 8 mathematics teaching in South African schools, using the TPACK conceptual framework. The findings are presented according to the three clusters identified through the association between the main variables of the TPACK model and other variables on the SITES 2006 teachers’ questionnaire: (1) impact of ICT use, (2) teacher practices and (3) barriers. A Cramér V of between 0.3 and 0.4 was considered to signal a medium effect that tended towards practically significant association, and a Cramér V of 0.4 or larger was considered to signal a large effect with practically significant association. The results indicate that the TPACK of mathematics teachers contributes towards more effective Grade 8 mathematics teaching in South African schools.
Seasonal cycles of fluorescent biological aerosol particles in boreal and semi-arid forests of Finland and Colorado
Authors: Schumacher C. J. , Pöhlker C. , Aalto P. , Hiltunen V. , Petäjä T. , Kulmala M. , Pöschl U. , Huffman J. A.
Published: December 2013

Abstract. Biological aerosol particles have become increasingly important for atmospheric study, but continuous measurements at high time and size resolution have not been available until recently. Here we report seasonal cycles of fluorescent biological aerosol particles (FBAP) from the boreal forest in Hyytiälä, Finland (18 months) and the semi-arid Manitou Experimental Forest, Colorado (10 months). FBAP at both locations were observed to be highest in summer and lowest in winter, increasing by factors of 12 and 5 between these seasons, respectively. In addition to the low temperatures and reduced sunlight during winter, we suggest that snow cover inhibited FBAP release from local terrestrial surfaces and that more extensive snow cover at the Finland site contributed to lower winter FBAP concentrations. Average size distributions at each site exhibited peaks between 1.5 and 6 μm in aerodynamic diameter. The Finland site consistently showed a dominant, narrow FBAP peak at ~ 3 μm in addition to discreet modes at ~ 1.5 and ~ 5 μm, whereas the Colorado site showed broader peaks at 1.5 and 5 μm, suggesting different modes of biological particles at the two sites. FBAP concentrations in both locations were shown to correlate with daily patterns of relative humidity (RH) during each season. Also during summer at each site, average FBAP concentration scaled with RH, but at the Finland site RH values above ~ 82% led to a significant decrease in FBAP concentration. We hypothesize that this is due to dew formation that inhibits bioparticle release. Lastly we show that rain during summer at each location led to pronounced increases in both fluorescent and total particle concentrations with FBAP peak particle size at ~ 2 μm and concentration scaling with rain intensity. We suggest that these particles are primarily fungal spores and other bioparticles lofted from splashing of rain droplets hitting soil and leaf surfaces. During the summer at the Colorado site we consistently observed a mode of ~ 4 μm particles appearing several hours after rain events that we suggest are fungal spores actively emitted when ambient conditions are most advantageous for spread and germination. The pronounced patterns of fluorescent bioparticles observed here suggest that parameterizations of both daily and seasonal cycles will be important to accurately reflect bioparticle emissions in future studies of atmospheric bioaerosols and their potential effects on clouds and precipitation.
Theoretical constraints on the cross-tail width of bursty bulk flows
Authors: Chen C. X.
Published: December 2013

Abstract. The characteristic cross-tail width of bursty bulk flows (BBFs) in earth's plasma sheet was investigated at two stages of its life, one at its onset, the other when it is fully developed. Equilibrium domains with gradient of magnetic field are constructed. Interchange instability analysis of such domains yields the most unstable mode with the half wave length comparable with the observed cross-tail width of a flow burst and the inverse of growth rate comparable with its duration. The thickness of the plasma sheet for the most unstable mode is also comparable to the width of BBFs in the north–south direction. We found that viscosity, the dimension of the unstable domain, the thickness of the plasma sheet and gradient of the magnetic field together determine the most unstable mode. The ion Larmor radius plays an important role in viscosity as half effective mean free path. For a fully developed flow, however, velocity-caused pressure difference between the leading and trailing sides of a flow burst also plays a role. The equatorial cross section of flow is reshaped and its cross-tail width is changed as well. Representing the surrounding medium with empirical magnetic field and plasma models, the force balance of the fast flow is analyzed. The cross-section area of flow burst is estimated to be one to several square earth radii, and the cross-tail width of fast flow is estimated to be 1 to 3 earth radii, which is consistent with observations of BBFs.
Climate change impacts on sea–air fluxes of CO2 in three Arctic seas: a sensitivity study using Earth observation
Authors: Land P. E. , Shutler J. D. , Cowling R. D. , Woolf D. K. , Walker P. , Findlay H. S. , Upstill-Goddard R. C. , Donlon C. J.
Published: December 2013

Abstract. We applied coincident Earth observation data collected during 2008 and 2009 from multiple sensors (RA2, AATSR and MERIS, mounted on the European Space Agency satellite Envisat) to characterise environmental conditions and integrated sea–air fluxes of CO2 in three Arctic seas (Greenland, Barents, Kara). We assessed net CO2 sink sensitivity due to changes in temperature, salinity and sea ice duration arising from future climate scenarios. During the study period the Greenland and Barents seas were net sinks for atmospheric CO2, with integrated sea–air fluxes of −36 ± 14 and −11 ± 5 Tg C yr−1, respectively, and the Kara Sea was a weak net CO2 source with an integrated sea–air flux of +2.2 ± 1.4 Tg C yr−1. The combined integrated CO2 sea–air flux from all three was −45 ± 18 Tg C yr−1. In a sensitivity analysis we varied temperature, salinity and sea ice duration. Variations in temperature and salinity led to modification of the transfer velocity, solubility and partial pressure of CO2 taking into account the resultant variations in alkalinity and dissolved organic carbon (DOC). Our results showed that warming had a strong positive effect on the annual integrated sea–air flux of CO2 (i.e. reducing the sink), freshening had a strong negative effect and reduced sea ice duration had a small but measurable positive effect. In the climate change scenario examined, the effects of warming in just over a decade of climate change up to 2020 outweighed the combined effects of freshening and reduced sea ice duration. Collectively these effects gave an integrated sea–air flux change of +4.0 Tg C in the Greenland Sea, +6.0 Tg C in the Barents Sea and +1.7 Tg C in the Kara Sea, reducing the Greenland and Barents sinks by 11% and 53%, respectively, and increasing the weak Kara Sea source by 81%. Overall, the regional integrated flux changed by +11.7 Tg C, which is a 26% reduction in the regional sink. In terms of CO2 sink strength, we conclude that the Barents Sea is the most susceptible of the three regions to the climate changes examined. Our results imply that the region will cease to be a net CO2 sink in the 2050s.
Extreme rainfall events can alter inter-annual biomass responses to water and N enrichment
Authors: Kong D. L. , Lü X. T. , Jiang L. L. , Wu H. F. , Miao Y. , Kardol P.
Published: December 2013

Abstract. Water availability has profound effects on plant growth and productivity in temperate and semiarid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses may be contingent on N availability. In this study, we examined the interactive effects of inter-annual precipitation variation and N addition on aboveground and live fine root biomass of a semiarid grassland in northern China for two consecutive years (2007 and 2008). Inter-annual variation in precipitation resulting mainly from the occurrence of extreme rainfall events in 2008 significantly affected above- and belowground plant biomass responses to water addition. In addition, variation of inter-annual precipitation by this extreme rainfall event suppressed plant responses to nitrogen addition and reduced the interaction effects between water and nitrogen addition. These effects of inter-annual precipitation fluctuation could be attributed to the negative influence of the extreme rainfall event on soil N and water availability, ultimately reducing plant rainfall use efficiency and nitrogen use efficiency. In conclusion, our results suggest ecosystem responses to water and N enrichment could be altered by inter-annual variation of precipitation regime caused by the naturally occurring extreme rainfall events.
Winter measurements of oceanic biogeochemical parameters in the Rockall Trough (2009–2012)
Authors: McGrath T. , Kivimäe C. , McGovern E. , Cave R. R. , Joyce E.
Published: December 2013

Abstract. This paper describes the sampling and analysis of biogeochemical parameters collected in the Rockall Trough in January/February of 2009, 2010, 2011 and 2012. Sampling was carried out along two transects, one southern and one northern transect each year. Samples for dissolved inorganic carbon (DIC) and total alkalinity (TA) were taken alongside salinity, dissolved oxygen and dissolved inorganic nutrients (total-oxidized nitrogen, nitrite, phosphate and silicate) to describe the chemical signatures of the various water masses in the region. These were taken at regular intervals through the water column. The data are available on the CDIAC database, http://cdiac.ornl.gov/ftp/oceans/Rockall_Trough/.
Flood design recipes vs. reality: can predictions for ungauged basins be trusted?
Authors: Efstratiadis A. , Koussis A. D. , Koutsoyiannis D. , Mamassis N.
Published: December 2013

Abstract. Despite the great scientific and technological advances in flood hydrology, everyday engineering practices still follow simplistic approaches, such as the rational formula and the SCS-CN method combined with the unit hydrograph theory that are easy to formally implement in ungauged areas. In general, these "recipes" have been developed many decades ago, based on field data from few experimental catchments. However, many of them have been neither updated nor validated across all hydroclimatic and geomorphological conditions. This has an obvious impact on the quality and reliability of hydrological studies, and, consequently, on the safety and cost of the related flood protection works. Preliminary results, based on historical flood data from Cyprus and Greece, indicate that a substantial revision of many aspects of flood engineering procedures is required, including the regionalization formulas as well as the modelling concepts themselves. In order to provide a consistent design framework and to ensure realistic predictions of the flood risk (a key issue of the 2007/60/EU Directive) in ungauged basins, it is necessary to rethink the current engineering practices. In this vein, the collection of reliable hydrological data would be essential for re-evaluating the existing "recipes", taking into account local peculiarities, and for updating the modelling methodologies as needed.
A new method for continuous measurements of oceanic and atmospheric N2O, CO and CO2: performance of off-axis integrated cavity output spectroscopy (OA-ICOS) coupled to non-dispersive infrared detection (NDIR)
Authors: Arévalo-Martínez D. L. , Beyer M. , Krumbholz M. , Piller I. , Kock A. , Steinhoff T. , Körtzinger A. , Bange H. W.
Published: December 2013

Abstract. A new system for continuous, highly resolved oceanic and atmospheric measurements of N2O, CO and CO2 is described. The system is based upon off-axis integrated cavity output spectroscopy (OA-ICOS) and a non-dispersive infrared analyzer (NDIR), both coupled to a Weiss-type equilibrator. Performance of the combined setup was evaluated by testing its precision, accuracy, long-term stability, linearity and response time. Furthermore, the setup was tested during two oceanographic campaigns in the equatorial Atlantic Ocean in order to explore its potential for autonomous deployment onboard voluntary observing ships (VOS). Improved equilibrator response times for N2O (2.5 min) and CO (45 min) were achieved in comparison to response times from similar chamber designs used by previous studies. High stability of the OA-ICOS analyzer was demonstrated by low optimal integration times of 2 and 4 min for N2O and CO respectively, as well as detection limits of < 40 ppt and precision better than 0.3 ppb Hz–1/2. Results from a direct comparison of the method presented here and well-established discrete methods for oceanic N2O and CO2 measurements showed very good consistency. The favorable agreement between underway atmospheric N2O, CO and CO2 measurements and monthly means at Ascension Island (7.96° S 14.4° W) further suggests a reliable operation of the underway setup in the field. The potential of the system as an improved platform for measurements of trace gases was explored by using continuous N2O and CO2 data to characterize the development of the seasonal equatorial upwelling in the Atlantic Ocean during two R/V Maria S. Merian cruises. A similar record of high-resolution CO measurements was simultaneously obtained, offering, for the first time, the possibility of a comprehensive view of the distribution and emissions of these climate-relevant gases in the area studied. The relatively simple underway N2O/CO/CO2 setup is suitable for long-term deployment onboard research and commercial vessels although potential sources of drift, such as cavity temperature, and further technical improvements towards automation, still need to be addressed.
Review Essay: Emmanuel Falque, The Metamorphosis of Finitude: An Essay on Birth and Resurrection
Authors: Trakakis N.N.
Published: December 2013

A review of Emmanuel Falque, The Metamorphosis of Finitude: An Essay on Birth and Resurrection,trans. George Hughes (New York: Fordham University Press, 2012).
Deleuze and Epicurean Philosophy: Atomic Speed and Swerve Speed
Authors: Bennett Michael James
Published: December 2013

This paper reconstructs Gilles Deleuze’s interpretation of Epicurean atomism, and explicates his claim that it represents a problematic idea, similar to the idea exemplified in early, “barbaric” accounts of the differential calculus. Deleuzian problematic ideas are characterized by a mechanism through whose activity the components of the idea become determinate in relating reciprocally to one another, rather than in being determined exclusively in relation to an extrinsic paradigm or framework. In Epicurean atomism, as Deleuze reads it, such a mechanism of determination can be found in the famous atomic “swerve”. It is necessary to bear this interpretation of Epicurean atomism in mind when understanding Deleuze and Guattari’s promulgation of a new image of thought in What is Philosophy?, which has an explicitly Epicurean inspiration. The paper argues that this inspiration is particularly evident to the extent that Deleuze and Guattari identify the sub-representative feature that lies at the heart of their new image of thought with “chaos”, defined as “infinite speed”. I claim that infinite speed, this otherwise puzzling feature of What is Philosophy?, ought to be understood in the light of Deleuze’s interpretation of Epicurus. Moreover, the Epicurean distinctions between different speeds must be read together with Deleuze’s appropriation of the metaphysics of the ancient Stoics, who, although widely recognized as Deleuze’s Hellenistic counterparts, lack important theoretical resources that the Epicureans provide for Deleuze.
Le corps, l’événement, et l’horizon indépassable de l’anthropologie: Réponse à Claude Romano
Authors: Jean Grégori
Published: December 2013

L’un des traits saillants du caractère philosophique de Claude Romano est sans doute d’aimer penser là où on ne l’attend pas. Depuis la publication, à la fin des années 1990, de ses deux livres majeurs consacrés à l’événement, l’on croyait légitime de le tenir pour ce phénoménologue de l’événementialité destiné à en exploiter le filon jusqu’à la dernière pépite. En 2010 pourtant, Au cœur de la raison, la phénoménologie, exprime clairement le besoin de parler d’autre chose et, en nouant notamment avec la philosophie d’inspiration analytique un dialogue inattendu, d’en parler autrement. Aussi ce livre, créant paradoxalement l’événement du fait de ne plus en parler, sembla témoigner d’un changement de cap — malgré, il est vrai, la publication concomitante de L’Aventure temporelle, qu’il était néanmoins possible de lire comme l’ultime mise au point sur une période désormais révolue. Les indices, du reste, ne manquaient pas, et les quelques autocritiques qui s’y trouvaient formulées, nous y reviendrons, renforcèrent l’idée d’un certain « tournant réaliste » dans l’œuvre.
Editorial
Authors: Rivera Ricardo
Published: December 2013

No tiene resumenDOI: http://dx.doi.org/10.5377/nexo.v22i2.424
Una aproximación a la evolución demográfica de América Latina
Authors: Castellón Raúl Hernández
Published: December 2013

DOI: http://dx.doi.org/10.5377/pdac.v3i0.482Revista Población y Desarrollo: Argonautas y Caminantes, Vol. 3, No. 3, 2008 10-14
La historiografía sobre ciudades, regiones y urbanización en Honduras: apuntes y bibliografía mínima
Authors: Euraque Darío A
Published: December 2013

DOI: http://dx.doi.org/10.5377/pdac.v3i0.484Revista Población y Desarrollo: Argonautas y Caminantes, Vol. 3, No. 3, 2008 28-31
Algunos procesos del sentido gregario humano
Authors: Véliz Vito
Published: December 2013

En la historia del ser humano, las ciudades son un componente de la civilización. Pero la civilización tiene fallas que parcialmente salen a flote en los complejos urbanos. Dos ejemplos prehispánicos en Honduras son de ciudades que abusaron del ambiente y sucum-bieron. Un ejemplo da muestras de buscar el ensanchamiento del espíritu, ubicándose sobre colinas y al mismo tiempo respetando las tierras planas y productivas. Hoy día nuestros gobiernos quieren llevarnos hacia la industrialización, pero se olvidan de los peldaños que necesariamente hay que escalar, antes de llegar a ese logro de la civilización. Uno de esos peldaños es tener alimentación suficiente y hasta de sobra, para que algunos pobladores puedan dedicarse a me-nesteres que no sean la producción de alimentos. Sin ningún interés por aprender del pasado, hoy día se está volviendo a utilizar tierra de vocación agrícola para urbanizaciones, para complejos comerciales e industriales y sin darle cabida a zonas de recreo. Debemos aprender de los errores y aciertos de nuestros antepasados, diseñar ciudades pequeñas, incorporar áreas de esparcimiento y buscar mecanismos para desarrollar esas ciudades pequeñas en cerros o colinas. DOI: http://dx.doi.org/10.5377/pdac.v3i0.485Revista Población y Desarrollo: Argonautas y Caminantes, Vol. 3, No. 3, 2008 32-38
Evaluación de la Dinámica de la Laguna de Apoyo mediante Trazadores Isotópicos y Geoquímicos
Authors: Palma Heyddy Calderón , Meza Yelba Flores
Published: December 2013

El objetivo de este estudio fue evaluar la dinámica de la Laguna de Apoyo usando herramientas isotópicas y geoquímicas. Esta laguna es de origen cratérico de 6.6 km de diámetro y 175 m de profundidad. La cuenca es endorreica, pequeña (38 km2), con un promedio de precipitación acumulada anual de 1454 mm. Los datos limnimétricos indican una disminución del nivel de la laguna de 10 m en los últimos 30 años.Se monitorearon parámetros fisicoquímicos y la composición isotópica (18O y D) de las aguas de la laguna, manantiales, pozos y de la precipitación durante 2006 y 2007. A pesar de la presencia de una barrera poco permeable al Oeste de la Laguna de Apoyo, los resultados hidroquímicos indican aportes desde el Noroeste y Suroeste. Sin embargo, aún no se descarta recarga local. Los datos isotópicos muestran que la evaporación es muy significativa en el balance hídrico de la laguna. Se identificó una zona de descarga de la laguna al Noreste, hacia el acuífero aguas abajo. Debido a la influencia de termalismo es necesario extender el monitoreo para definir más en detalle la zona de descarga y finalizar el balance isotópico. Esto es muy importante dado el alto contenido de sales y arsénico en la laguna y la influencia que ésta puede tener en el acuífero de Granada, ubicado aguas abajo.DOI: http://dx.doi.org/10.5377/uyc.v5i8.315Universidad y Ciencia No 8 Año 5 2010 22-26
Escurrimiento de Plaguicidas al Mar Caribe Nicaragüense - Establecimiento de un Sistema de Monitoreo Ambiental
Authors: Cuadra Jorge , Vammen Katherine
Published: December 2013

Nicaragua ha basado su economía en una estructura de agro exportación principalmente de materias primas. Desde el auge algodonero experimentado en décadas pasadas hasta la actualidad, en el país ha persistido una cultura de aplicación de grandes cantidades de plaguicidas con diferentes niveles de toxicidad y persistencia, que se escurren a través de la cuenca de drenaje contaminando recursos hídricos superficiales, subterráneos y zonas costeras del Caribe y Pacífico Nicaragüense. Existe escasa información sobre la dinámica de estos contaminantes en los ecosistemas de la costa Caribe, por lo que se estableció un programa de monitoreo costero cuyo objetivo es evaluar el escurrimiento de plaguicidas y generar información ambiental que ayude a determinar sus fuentes, causas y promover prácticas agrícolas adecuadas que den como resultado la reducción del escurrimiento hacia el Mar Caribe. Un primer estudio para el establecimiento de la línea base, se realizó en tres cuencas hidrográficas y zonas costeras del Caribe Nicaragüense, donde se analizaron residuos de plaguicidas persistentes utilizados en el pasado y de uso actual o reciente, incluyéndose en una segunda fase sitios de muestreo en zonas marinas. La determinación de residuos de plaguicidas se realizó, desarrollando innovadoras técnicas de análisis por cromatografía de gases con detectores de captura electrónica, termoiónico específico y espectrometría de masas. Se estableció un sistema de monitoreo que genera información sobre el grado de contaminación en las cuencas hidrográficas, zonas costeras y marinas, que aporta al desarrollo de estrategias adecuadas dirigidas a reducir el escurrimiento de plaguicidas al Mar Caribe Nicaragüense.DOI: http://dx.doi.org/10.5377/uyc.v5i8.316Universidad y Ciencia No 8 Año 5 2010 27-32
Editorial No.59
Authors: Jo Gustavo Castro
Published: December 2013

DOI: http://dx.doi.org/10.5377/wani.v59i0.254Wani No.59 2009 pp.3
"Limi bara Butku": Tâ upla Brooklyn Rivera wal aisanka kum
Authors: Editor The
Published: December 2013

DOI: http://dx.doi.org/10.5377/wani.v59i0.260Wani No.59 2009 pp.72-75
Variações metabólicas em indivíduos em utilização de Bauhinia forficata
Authors: Heller Mônica , Dal Bosco Simone Morelo , Rempel Claudete , Moreira Thaís Rodrigues
Published: December 2013

Introdução: As plantas medicinais foram, durante muito tempo, a base da terapêutica. Entre as inúmeras espécies vegetais de interesse medicinal, encontram-se as do gênero Bauhinia. Objetivos: Relacionar os índices antropométricos, pressão arterial e glicemia de jejum com o uso de Bauhinia forficata. Métodos: Realizou-se estudo do tipo caso-controle em uma amostra de 54 indivíduos divididos em: grupo 1 (intervenção), composto por 31 participantes; e grupo 2 (controle), com 23 sujeitos. Efetuaram-se verificações de peso, pressão arterial e glicemia, antes e após consumo do chá, num intervalo de oito meses. Resultados: No grupo 1 houve diferença estatisticamente significativa para valores de pressão arterial diastólica (p 0,001). O grupo 2 não apresentou diferença estatística em nenhuma variável. Comparando-se os dois grupos, encontrou-se diferença nas variáveis peso (p=0,037) e índice de massa corporal (p=0,047). Conclusões: As variações encontradas no peso, índice de massa corporal e pressão arterial diastólica sugerem que Bauhinia forficata auxilia no controle desses fatores.
Efeito de diferentes tempos de intervalos entre exercícios no desempenho das repetições
Authors: Britto Rafael , Scudese Estevão , Senna Gilmar , Novaes Jefferson Da Silva , Miranda Humberto
Published: December 2013

Introdução: O intervalo apresenta relação direta com o desempenho das repetições; contudo, suas relações com diferentes métodos de treinamento permanecem desconhecidas. Objetivo: Verificar a influência de diferentes intervalos e métodos de treinamento no desempenho das repetições. Métodos: Dezessete homens (23,50 ± 3,54 anos; 77,44 ± 7,26 kg; 176,35 ± 1,41 cm; 24,92 ± 2,49 kg/m2) realizaram quatro sessões: SEQ1 consistiu em uma série do Tríceps Puxador (TP) e Rosca Bíceps (RB), para três minutos de intervalo; SEQ2: uma série de TP e RB, com 20 segundos entre exercícios; SEQ3: uma série de TP e Abdução de Ombros (AO), com três minutos e SEQ4: uma série de TP e AO, com 20 segundos. Resultados: SEQ2 apresentou um menor número de repetições comparado às demais situações de intervalo e método (p < 0,001). Conclusão: A execução do método agonista/antagonista com intervalos curtos acarretou reduções no desempenho de repetições.
Risco de queda em idosos com doença de Alzheimer institucionalizados
Authors: Ferreira Lucas Lima , Sanches Giliadi Gadiel Américo , Marcondes Laís Passos , Saad Paulo Cesar Balade
Published: December 2013

Introdução: Idosos com doença de Alzheimer (DA) apresentam diferenças no equilíbrio e marcha, de acordo com o estágio da patologia, que pode predispô-los a quedas. Objetivo: Avaliar o impacto da DA no risco de queda em idosos residentes em uma instituição de longa permanência. Métodos: Foram avaliados 20 voluntários de ambos os sexos, com DA, sendo traçado o perfil sociodemográfico e avaliados a marcha e o equilíbrio, por meio da escala de Tinetti. Resultados: Verificou-se que a maioria dos participantes (75%) era do sexo feminino, com idade média de 77,8 ± 10,3 anos e tempo de institucionalização de 2,4 ± 1,7 anos. Foi encontrado alto risco de queda nos portadores de DA (70%), verificando-se que, quanto maior a idade maior o risco. Conclusão: Este estudo demonstrou alto risco de queda nos idosos institucionalizados, e este risco esteve correlacionado com idade mais avançada, igual ou superior a 80 anos.
Effects of chronic treatment with chlorpheniramine on anxiety and emotional memory in mice
Authors: Gianlorenço Anna Carolyna , Serafim Kelly Regina , Canto-de-Souza Azair , Mattioli Rosana
Published: December 2013

Introduction: H1 receptors mediate actions in brain activity, and antihistamines such as chlorpheniramine (CPA) act as H1 antagonists. Objective: This study investigated the effects of chronic treatment with CPA on anxiety and emotional memory in mice in the elevated plus-maze (EPM). Method: Male Swiss albino mice received chronic treatment with saline or CPA for 15 days. After this, the test was performed on two consecutive days. In Trial 1, mice received an injection of saline or CPA, and 40 minutes later they were exposed to the EPM. Twenty-four hours later, the mice received injections again and were retested. Results: Results showed no effects on anxiety or locomotor activity. During trial 2, open-arm exploration diminished in mice treated only with CPA with a dosage of 16 mg/kg (ANOVA, SNK
Influência do fortalecimento muscular na independência funcional de indivíduos parkinsonianos
Authors: Antônio Ana Márcia Dos Santos , Bertoldi Flávia Cristina , Faganello-Navega Flávia Roberta
Published: December 2013

Introdução: A doença de Parkinson é uma doença crônica do sistema nervoso que leva a um quadro clínico de tremor de repouso, bradicinesia, rigidez muscular e instabilidade postural. Esses sintomas, por sua vez, influenciam diretamente na independência funcional do indivíduo. Objetivo: Analisar a influência do fortalecimento muscular na independência funcional de indivíduos parkinsonianos. Método: Fizeram parte do estudo dez sujeitos de ambos os gêneros. Avaliaram-se a independência funcional, a força de membros inferiores, a força de preensão palmar e realizou-se o teste de uma repetição máxima. Após a avaliação foi realizado o programa de fortalecimento muscular por 12 semanas. Resultados: Verificou-se melhora na independência funcional (p=0,007), na força de membros inferiores (p=0,01), e houve aumento da força de preensão palmar, tanto da mão dominante (p=0,007) quanto da não dominante (p=0,02). Conclusão: O fortalecimento muscular proporcionou melhora da independência funcional de indivíduos com doença de Parkinson.
Obstacles and Affordances for Integer Reasoning: An Analysis of Children's Thinking and the History of Mathematics
Authors: Bishop Jessica Pierson , Lamb Lisa L. , Philipp Randolph A. , Whitacre Ian , Schappelle Bonnie P. , Lewis Melinda L.
Published: December 2013

We identify and document 3 cognitive obstacles, 3 cognitive affordances, and 1 type of integer understanding that can function as either an obstacle or affordance for learners while they extend their numeric domains from whole numbers to include negative integers. In particular, we highlight 2 key subsets of integer reasoning: understanding or knowledge that may, initially, interfere with one's learning integers (which we call cognitive obstacles) and understanding or knowledge that may afford progress in understanding and operating with integers (which we call cognitive affordances). We analyzed historical mathematical writings related to integers as well as clinical interviews with children ages 6-10 to identify critical, persistent cognitive obstacles and powerful ways of thinking that may help learners to overcome obstacles.
Self-Explanation Training Improves Proof Comprehension
Authors: Hodds Mark , Alcock Lara , Inglis Matthew
Published: December 2013

In this article, the authors report 3 experiments demonstrating that a simple booklet containing self-explanation training, designed to focus students' attention on logical relationships within a mathematical proof, can significantly improve their proof comprehension.
Quantitative Reasoning and the Sine Function: The Case of Zac
Authors: Moore Kevin C.
Published: December 2013

A growing body of literature has identified quantitative and covariational reasoning as critical for secondary and undergraduate student learning, particularly for topics that require students to make sense of relationships between quantities. The present study extends this body of literature by characterizing an undergraduate precalculus student's progress during a teaching experiment exploring angle measure and trigonometric functions.
Concise Review: Identifying Limbal Stem Cells: Classical Concepts and New Challenges
Authors: Joe Aaron W. , Yeung Sonia N.
Published: December 2013

The presence of a clear cornea is required for vision, and corneal epithelial cells play a key role. There is a long held view, supported by decades of study, that corneal epithelial stem cells reside at the limbus to regulate homeostatic cell turnover and wound healing. However, the identification of specific markers that allow the isolation and characterization of limbal stem cells remains elusive. Here, we review the classical concepts of limbal stem cell identity and highlight the current state of the field.
Spatial variability of the Rotterdam urban heat island as influenced by urban land use
Authors: Heusinkveld Bert G. , Steeneveld G. J. , van Hove L. W. A. , Jacobs C. M. J. , Holtslag A. A. M.
Published: December 2013

Novel bicycle traverse meteorological measurements were made in Rotterdam to assess the spatial variation of temperature during a tropical day. Nocturnal spatial urban temperature differences of 7 K were found to be related to city morphology. During midday measurements, the downtown was up to 1.2 K warmer than the surrounding rural area while a city park was 4.0 K cooler than downtown. A regression analysis showed that the nocturnal measured urban heat island (UHI) can be linked to land use, namely vegetation, built‐up area, and water and is most significant for vegetation. From the traverse observation data, a multiple linear regression model was constructed and independently validated with 3 year summertime UHI statistics derived from four urban fixed meteorological stations and two fixed rural stations. Wind rose analysis shows that UHI is strongest from easterly directions and that the temperature signal of the WMO station is influenced from urban directions. A regression model reproduced the nighttime spatial variability of the UHI within a fractional bias of 4.3% and was used to derive an UHI map of Rotterdam and surroundings. This map shows that high‐density urban configurations lacking greenery or close to large water bodies are vulnerable to high nocturnal temperatures during heat waves. The UHI map can be used as a valuable planning tool for mitigating nocturnal urban heat stress or identifying neighborhoods at risk during heat waves.
A model‐based insight into the coupling of nitrogen and sulfur cycles in a coastal upwelling system
Authors: Azhar Muchamad Al , Canfield Donald E. , Fennel Katja , Thamdrup Bo , Bjerrum Christian J.
Published: December 2013

The biogeochemical cycling in oxygen‐minimum zones (OMZs) is dominated by the interactions of microbial nitrogen transformations and, as recently observed in the Chilean upwelling system, also through the energetically less favorable remineralization of sulfate reduction. The latter process is masked, however, by rapid sulfide oxidation, most likely through nitrate reduction. Thus, the cryptic sulfur cycle links with the nitrogen cycle in OMZ settings. Here, we model the physical‐chemical water column structure and the observed process rates as driven by formation and sinking of organic detritus, to quantify the nitrogen and sulfur cycles in the Chilean OMZ. A new biogeochemical submodule was developed and coupled to the Regional Ocean Model System (ROMS). The model results generally agree with the observed distribution of reactive species and the measured process rates. Modeled heterotrophic nitrate reduction and sulfate reduction are responsible for 47% and 36%, respectively, of organic remineralization in a 150 m deep zone below mixed layer. Anammox contributes to 61% of the fixed nitrogen lost to N2 gas, while the rest of the loss is through canonical denitrification as a combination of organic matter oxidation by nitrite reduction and sulfide‐driven denitrification. Mineralization coupled to heterotrophic nitrate reduction supplies ~48% of the ammonium required by anammox. Due to active sulfate reduction, model results suggest that sulfide‐driven denitrification contributes to 36% of the nitrogen loss as N2 gas. Our model results highlight the importance of considering the coupled nitrogen and sulfur cycle in examining open‐ocean anoxic processes under present, past, and future conditions.
Variations of the neutral temperature and sodium density between 80 and 107 km above Tromsø during the winter of 2010–2011 by a new solid‐state sodium lidar
Authors: Nozawa S. , Kawahara T. D. , Saito N. , Hall C. M. , Tsuda T. T. , Kawabata T. , Wada S. , Brekke A. , Takahashi T. , Fujiwara H. , Ogawa Y. , Fujii R.
Published: December 2013

A new solid‐state sodium lidar installed at Ramfjordmoen, Tromsø (69.6°N, 19.2°E), started observations of neutral temperature together with sodium density in the mesosphere‐lower thermosphere (MLT) region on 1 October 2010. The new lidar provided temperature data with a time resolution of 10 min and with good quality between ∼80 and ∼105 km from October 2010 to March 2011. This paper aims at introducing the new lidar with its observational results obtained over the first 6 months of observations. We succeeded in obtaining neutral temperature and sodium density data of ∼255.5 h in total. In order to evaluate our observations, we compared (1) the sodium density with that published in the literature, (2) average temperature and column sodium density data with those obtained with Arctic Lidar Observatory for Middle Atmosphere Research Weber sodium lidar, and (3) the neutral temperature data with those obtained by Sounding of the Atmosphere with Broadband Emission Radiometry/Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. For the night of 5 October 2010, we succeeded in conducting simultaneous observations of the new lidar and the European Incoherent Scatter UHF radar with the tristatic Common Program 1 (CP‐1) mode. Comparisons of neutral and ion temperatures showed a good agreement at 104 km between 0050 and 0230 UT on 6 October 2010 when the electric field strength was smaller, while significant deviations (up to ∼25 K) are found at 107 km. We evaluated contributions of Joule heating and electron‐ion heat exchange, but derived values seem to be underestimated.
Infragravity response to variable wave forcing in the nearshore
Authors: Contardo S. , Symonds G.
Published: December 2013

Analysis of field observations of sea‐surface elevation reveals the role of time‐varying incident forcing and bound wave release mechanisms on the generation of infragravity waves on a barred beach. Observations of infragravity response were obtained during sea breeze and swell periods with wave height varying from 0.2 to 1.2 m and wave period from 3 to 16 s. The observations show a stronger infragravity response to longer period incident swell than to short period wind‐sea. During the peak of the sea breeze, short period wind‐sea is conducive to long wave generation by breakpoint forcing. Under swell‐dominated conditions, the frequency and wave number of incoming bound waves associated with wave groups may satisfy the linear dispersion relationship, leading to resonant forcing of a free wave that appears to be released from the wave group. The transition between long wave generation due to bound wave release and time‐varying breakpoint forcing agrees with the surf beat similarity parameter.
Analyzing the transmission structures of long continuing current processes from negative ground flashes on the Qinghai‐Tibetan Plateau
Authors: Fan Xiangpeng , Zhang Guangshu , Wang Yanhui , Li Yajun , Zhang Tong , Wu Bin
Published: December 2013

This paper presents a new overlap and progressive method using either a one‐point charge model or a point dipole model for studying the electric field change data of lightning and tests the suitability of the proposed method by analyzing the slow electric field change of the long continuing current data from two negative ground flashes. The current measurements of the ground flashes are from the Composite Observing Experiment for Lightning project carried out in the Datong region of Qinghai Province, China, in 2009, obtained from field observations synchronized through high‐precision GPS clocks at seven observation stations. Analysis shows that the time‐averaged current can reach 800 A, and the current intensity relates to the height of the top of the return stroke before the continuing current process. The two current processes studied in this work neutralized a large amount of negative charge, 39.5C and 60.8C, respectively. The neutralized charges from the negative charge layer are typically at 2.5–4.7 km above ground. The intracloud transition of the positive leader is a complex process, and the horizontal propagation of the positive leader plays an important role in current duration as well as horizontally influencing the center of the electrical dipole moment with an obvious change of up to 3.0 km. The proposed analysis method is very useful compared to previous methods in terms of determining infinitesimal changes in long continuing currents. This work's new analysis method will help increase understanding of the fine physical processes of long continuing current processes.
Trends in summer extreme temperatures over the Iberian Peninsula using nonurban station data
Authors: Acero F. J. , García José Agustín , Gallego María Cruz , Parey Sylvie , Dacunha‐Castelle Didier
Published: December 2013

Heat wave event trends over the Iberian Peninsula (IP) are studied using extreme value theory, specifically the peaks‐over‐threshold (POT) approach. Summer (June–August) daily temperature records from 20 observatories regularly distributed over Iberia in places far from urban effects were available for the common period 1961–2010. Heat waves are defined as days occurring above the 95th percentile of the temperature distribution, considering both maximum (Tmax) and minimum (Tmin) temperatures. These events were identified using a “run declustering” scheme to select independent extreme events exceeding the threshold. Also, the dates of occurrence of the independent events were fitted to a Poisson process. Trends in the following parameters were studied: the scale parameter of the POT approach, the Poisson intensity, mean, return level period, and low (25th percentile) and high (75th percentile) values. The optimal trends in the Poisson intensity considering bothTmaxandTminshow a major increase in the occurrence of heat waves. Also, the rise in the return level trend was less than that in the mean ofTminandTmax, and the analysis of the values ofTminandTmaxshowed a greater increasing trend in the low values (25th percentile) than in the high values (75th percentile), especially forTmax, leading to a decrease in the variance. Over the IP, temperature extremes are increasing but not as much as the mean because the variance is tending to decrease. This highlights the important role of variance in the evolution of extremes.
First simultaneous measurements of ozone, CO, and NOy at a high‐altitude regional representative site in the central Himalayas
Authors: Sarangi Tapaswini , Naja Manish , Ojha N. , Kumar R. , Lal S. , Venkataramani S. , Kumar A. , Sagar R. , Chandola H. C.
Published: December 2013

Simultaneous in situ measurements of ozone, CO, and NOy have been made for the first time at a high altitude site Nainital (29.37°N, 79.45°E, 1958 m above mean sea level) in the central Himalayas during 2009–2011. CO and NOy levels discern slight enhancements during the daytime, unlike in ozone. The diurnal patterns are attributed mainly to the dynamical processes including vertical winds and the boundary layer evolution. Springtime higher levels of ozone (57.5 ± 12.6 ppbv), CO (215.2 ± 147 ppbv), and NOy (1918 ± 1769.3 parts per trillion by volume (pptv)) have been attributed mainly to regional pollution supplemented with northern Indian biomass burning. However, lower levels of ozone (34.4 ± 18.9 ppbv), CO (146.6 ± 71 ppbv), and NOy (1128.6 ± 1035 pptv) during summer monsoon are shown to be associated with the arrival of air mass originated from marine regions. Downward transport from higher altitudes is estimated to enhance surface ozone levels over Nainital by 6.1–18.8 ppbv. The classification based on air mass residence time, altitude variations along trajectory, and boundary layer shows higher levels of ozone (57 ± 14 ppbv), CO (206 ± 125 ppbv), and NOy (1856 ± 1596 pptv) in the continental air masses when compared with their respective values (28 ± 13 ppbv, 142 ± 47 ppbv, and 226 ± 165 pptv) in the regional background air masses. In general, positive interspecies correlations are observed which suggest the transport of air mass from common source regions (except during winter). Ozone‐CO and ozone‐NOy slope values are found to be lower in comparison to those at other global sites, which clearly indicates incomplete in situ photochemistry and greater role of transport processes in this region. The higher CO/NOy value also confirms minimal influence of fresh emissions at the site. Enhancements in ozone, CO, and NOy during high fire activity period are estimated to be 4–18%, 15–76%, and 35–51%, respectively. Despite higher CO and NOy concentrations at Nainital, ozone levels are nearly similar to those at other global high‐altitude sites.
A statistical framework to quantify spatial variation in channel gradients using the integral method of channel profile analysis
Authors: Mudd Simon M. , Attal Mikaël , Milodowski David T. , Grieve Stuart W. D. , Valters Declan A.
Published: December 2013

We present a statistical technique for analyzing longitudinal channel profiles. Our technique is based on the integral approach to channel analysis: Drainage area is integrated over flow distance to produce a transformed coordinate, χ, which has dimensions of length. Assuming that profile geometry is conditioned by the stream power law, defined as E = KAmSn where E is erosion rate, K is erodibility, A is drainage area, S is channel gradient, and m and n are constants, the slope of a transformed profile in χ‐elevation space should reflect the ratio of erosion rate to channel erodibility raised to a power 1/n; this quantity is often referred to as the channel steepness and represents channel slope normalized for drainage area. Our technique tests all possible contiguous segments in the channel network to identify the most likely locations where channel steepness changes and also identifies the most likely m/n ratio. The technique identifies locations where either erodibility or erosion rates are most likely to be changing. Tests on a simulated landscape demonstrate that the technique can accurately retrieve both the m/n ratio and the correct number and location of segments eroding at different rates where model assumptions apply. Tests on natural landscapes illustrate how the method can distinguish between spurious channel convexities due to incorrect selection of the m/n ratio from those which are candidates for changing erodibility or erosion rates. We also show how, given erosion or uplift rate constraints, the method can be used to constrain the slope exponent, n.
New Electrical Power Steering Systems
Authors: Würges Mathias
Published: December 2013

Electric‐power‐assisted steering (
EPAS
) systems replace hydraulic systems in a broad range of vehicle categories because of the fuel efficiency of this technology and the wide range of opportunities for new functional applications. This chapter illustrates the various types of
EPAS
systems and their application range and explains the requirements to meet performance, comfort, and safety goals as well as the technologies applied.

Basically, the steering system is divided into subsystems. The mechanical system including the
EPAS
column, the intermediate shaft, and the steering gear has to ensure the safe transfer of torque from the steering wheel to the tie rods. A precise conversion from the steering wheel angle to the wheel angle as well as a comfortable steering feeling and adjustment mechanism is realized in this system. The electrical subsystem detects the driver's steering request and transfers it into assistance torque for each driving condition, respecting the vehicle and steering system dynamics. Furthermore, advanced steering functions are implemented in modern
EPAS
systems to improve the comfort of driving and to support vehicle functionalities. This chapter gives a detailed overview of the mechanical and electrical system components and their principle concept based on a column
EPAS
system from the global steering system supplier
NSK
. Finally, a brief overview is given about safety regulations and the corresponding system approach.