bluuebunny/crossref_metadata_2025 huggingface dataset:
Ground cover rice production systems increase soil carbon and nitrogen stocks at regional scale
Authors: Liu M. , Dannenmann M. , Lin S. , Saiz G. , Yan G. , Yao Z. , Pelster D. E. , Tao H. , Sippel S. , Tao Y. , Zhang Y. , Zheng X. , Zuo Q. , Butterbach-Bahl K.
Published: August 2015

Abstract. Rice production is increasingly limited by water scarcity. Covering paddy rice soils with films (so-called ground cover rice production system: GCRPS) can significantly reduce water demand as well as overcome temperature limitations at the beginning of the growing season, which results in greater grain yields in relatively cold regions and also in those suffering from seasonal water shortages. However, it has been speculated that both increased soil aeration and temperature under GCRPS result in lower soil organic carbon and nitrogen stocks. Here we report on a regional-scale experiment conducted in Shiyan, a typical rice-producing mountainous area of China. We sampled paired adjacent paddy and GCRPS fields at 49 representative sites. Measured parameters included soil carbon (C) and nitrogen (N) stocks (to 1 m depth), soil physical and chemical properties, δ15N composition of plants and soils, potential C mineralization rates, and soil organic carbon (SOC) fractions at all sampling sites. Root biomass was also quantified at one intensively monitored site. The study showed that: (1) GCRPS increased SOC and N stocks 5–20 years following conversion from traditional paddy systems; (2) there were no differences between GCRPS and paddy systems in soil physical and chemical properties for the various soil depths, with the exception of soil bulk density; (3) GCRPS increased above-ground and root biomass in all soil layers down to a 40 cm depth; (4) δ15N values were lower in soils and plant leaves indicating lower NH3 volatilization losses from GCRPS than in paddy systems; and (5) GCRPS had lower C mineralization potential than that observed in paddy systems over a 200-day incubation period. Our results suggest that GCRPS is an innovative production technique that not only increases rice yields using less irrigation water, but that it also increases SOC and N stocks.
Spatial and temporal trends in summertime climate and water quality indicators in the coastal embayments of Buzzards Bay, Massachusetts
Authors: Rheuban J. E. , Williamson S. C. , Costa J. E. , Glover D. M. , Jakuba R. W. , McCorkle D. C. , Neill C. , Williams T. , Doney S. C.
Published: August 2015

Abstract. Degradation of coastal ecosystems by eutrophication is largely defined by nitrogen loading from land via surface and groundwater flows. However, indicators of water quality are highly variable due to a myriad of other drivers, including temperature and precipitation. To evaluate these drivers, we examined spatial and temporal trends in a 22 year record of summer water quality data from 122 stations in 17 embayments within Buzzards Bay, MA (USA), collected through a citizen science monitoring program managed by Buzzards Bay Coalition. To identify spatial patterns across Buzzards Bay's embayments, we used a principle component and factor analysis and found that rotated factor loadings indicated little correlation between inorganic nutrients and organic matter and chlorophyll a (Chl a) concentration. Factor scores showed that embayment geomorphology in addition to nutrient loading was a strong driver of water quality, where embayments with surface water inputs showed larger biological impacts than embayments dominated by groundwater influx. A linear regression analysis of annual summertime water quality indicators over time revealed that from 1992 to 2013, most embayments (15 of 17) exhibited an increase in temperature (mean rate of 0.082 ± 0.025 (SD) °C yr−1) and Chl a (mean rate of 0.0171 ± 0.0088 log10 (Chl a; mg m−3) yr−1, equivalent to a 4.0 % increase per year). However, only 7 embayments exhibited an increase in total nitrogen (TN) concentration (mean rate 0.32 ± 0.47 (SD) μM yr−1). Average summertime log10 (TN) and log10 (Chl a) were correlated with an indication that yield of Chl a per unit total nitrogen increased with time suggesting the estuarine response to TN may have changed because of other stressors such as warming, altered precipitation patterns, or changing light levels. These findings affirm that nitrogen loading and physical aspects of embayments are essential in explaining observed ecosystem response. However, climate-related stressors may also need to be considered by managers because increased temperature and precipitation may worsen water quality and partially offset benefits achieved by reducing nitrogen loading.
Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3c
Authors: Prather M. J.
Published: August 2015

Abstract. A new approach for modeling photolysis rates (J values) in atmospheres with fractional cloud cover has been developed and is implemented as Cloud-J – a multi-scattering eight-stream radiative transfer model for solar radiation based on Fast-J. Using observations of the vertical correlation of cloud layers, Cloud-J 7.3c provides a practical and accurate method for modeling atmospheric chemistry. The combination of the new maximum-correlated cloud groups with the integration over all cloud combinations by four quadrature atmospheres produces mean J values in an atmospheric column with root mean square (rms) errors of 4 % or less compared with 10–20 % errors using simpler approximations. Cloud-J is practical for chemistry–climate models, requiring only an average of 2.8 Fast-J calls per atmosphere vs. hundreds of calls with the correlated cloud groups, or 1 call with the simplest cloud approximations. Another improvement in modeling J values, the treatment of volatile organic compounds with pressure-dependent cross sections, is also incorporated into Cloud-J.
Partnerships for affordable and equitable disaster insurance
Authors: Mysiak J. , Pérez-Blanco C. D.
Published: August 2015

Abstract. Extreme events are becoming more frequent and intense, inflating the economic damages and social hardship set-off by natural catastrophes. Amidst budgetary cuts, there is a growing concern on societies' ability to design solvent disaster recovery strategies, while addressing equity and affordability concerns. The participation of private sector along with public one through Public-Private Partnerships (PPPs) has gained on importance as a means to address these seemingly conflicting objectives through the provision of (catastrophic) natural hazard insurance. This is the case of many OECD countries, notably some EU Member States such as the United Kingdom and Spain. The EU legislator has adapted to this new scenario and recently produced major reforms in the legislation and regulation that govern the framework in which PPPs for (catastrophic) natural hazard insurance develop. This paper has a dual objective: (1) review the complex legal background that rules the provision of insurance against natural catastrophes in the EU after these major reforms, (2) assess the implications of the reforms and offer concise Policy Guiding Principles.
Turbulence observations in the Gulf of Trieste under moderate wind forcing and different water column stratification
Authors: Falcieri F. M. , Kantha L. , Benetazzo A. , Bergamasco A. , Bonaldo D. , Barbariol F. , Malačič V. , Sclavo M. S. , Carniel S.
Published: August 2015

Abstract. During the oceanographic campaign CARPET2014, between 30 January and 4 February 2014, a total of 478 microstructure profiles (grouped into 145 ensembles) and 38 CTD casts were made in the Gulf of Trieste (Northern Adriatic Sea) under moderate wind forcing (average wind speed 10 m s-1) and heat fluxes (net negative heat flux in the range of 150 to 400 W m-2). Among the collected profiles, there were three sets of yoyo casts, each lasting for about 12 h for a total of 50 casts. Overall, these represent the first turbulence observations collected in the Gulf of Trieste. Microstructure profiles collected with a free-falling profiler must be taken in enables of repeated casts, with the objective of obtaining more statistically significant values for turbulence parameters. This approach is certainly feasible in shallow waters, but has a down side when the vertical density structure includes strong interfaces that can move up or down between subsequent casts, under the influence of tides and internal waves. In order to minimize the smearing effect of such interfacial displacements on mean quantities, we developed an algorithm to realign, according to the temperature profile, successive microstructure profiles to produce sharper and more meaningful mean profiles of measured turbulence parameters. During CARPET2014, the water column in the Gulf evolved from a well-mixed condition to a stratified one, due to Adriatic waters intruding at the bottom along the Gulf's south-eastern coast. These waters stratified the water column and changed its stability characteristics, which in turn prevented wind driven turbulence from penetrating to the bottom of the water column. In this study, we show that during a warm and relatively dry winter, such as in 2014, the Gulf of Trieste was not completely mixed because of the influence of bottom waters intruding from the open sea, even under moderate wind forcing. Inside the Gulf, two types of water intrusions from the Adriatic Sea were observed during the yoyo casts: one coming from its northern coast (i.e. warmer, saltier and more turbid) and one coming from the open sea in front of the Po Delta (i.e. cooler, fresher and less turbid). Those two intrusions behaved similarly but had a different impact on turbulence kinetic energy dissipation rate profiles. The former, with high turbidity, acted as a barrier to wind-driven turbulence, while the latter, with low sediment concentrations and a smaller density gradient when compared to the rest of the water column, was not able to suppress downward penetration of turbulence from the surface to the same degree.
Monitoring Atlantic overturning circulation variability with GRACE-type ocean bottom pressure observations – a sensitivity study
Authors: Bentel K. , Landerer F. W. , Boening C.
Published: August 2015

Abstract. The Atlantic Meridional Overturning Circulation (AMOC) is a key mechanism for large-scale northward heat transport and thus plays an important role for global climate. Relatively warm water is transported northward in the upper layers of the North Atlantic Ocean, and after cooling at subpolar latitudes, sinks down and is transported back south in the deeper limb of the AMOC. The utility of in-situ ocean bottom pressure (OBP) observations to infer AMOC changes at single latitudes has been characterized in recent literature using output from ocean models. We extend the analysis and examine the utility of space-based observations of time-variable gravity and the inversion for ocean bottom pressure to monitor AMOC changes and variability between 20 and 60° N. Consistent with previous results, we find a strong correlation between the AMOC signal and OBP variations, mainly along the western slope of the Atlantic basin. We then use synthetic OBP data – smoothed and filtered to resemble the resolution of the GRACE gravity mission – and reconstruct geostrophic AMOC transport. Due to the coarse resolution of GRACE-like OBP fields, we find that leakage of signal across the step slopes of the ocean basin is a significant challenge at certain latitudes. However, overall, the inter-annual AMOC anomaly time series can be recovered from 20 years of monthly GRACE-like OBP fields with errors less than 1 Sverdrup.
Reflection on Mathematics Classroom Discourse: The Perspective of Critical Pedagogy
Authors: Wang Xiong
Published: August 2015

A close attention has been paid to classroom discourse by researchers and teachers in the recent years. However, scanty research is conducted on the reflection of the mathematics classroom discourse from the perspective of critical pedagogy. Such angle will be adopted in this paper to address the research gap. The reflection on the mathematics classroom discourse is made by presenting the interactive discourse as an expectation of mathematics classroom teaching and by indicating the exclusive discourse and its costs with recourse to commenting the dominant mathematics classroom teaching. The presentation of interactive discourse and the indication of exclusive discourse are not about to offer a solution to dominant discourse but trigger the further consideration into the discourse in mathematics classroom.
La llegada de las maras a Cataluña
Authors: Herrero Blanco Santiago
Published: August 2015

La llegada de las maras era una de las principales amenazas vinculadas con la aparición de las primeras bandas juveniles de origen americano en España, a mediados de la década del 2000. Los niveles de violencia y la actividad delictiva que llevaban a cabo en América Central y del Norte, junto a informaciones acerca de su voluntad de expandirse por Europa, así lo confirmaban. La vistosidad de algunos de sus miembros así como sus niveles de violencia han hecho que los medios de comunicación les prestaran una especial atención, transmitiendo un mensaje, en muchos casos, alarmista y sensacionalista.No obstante, con el paso del tiempo este riesgo no se ha llegado a concretar en toda su extensión. Tanto la Mara Salvatrucha como el Barrio 18 han llegado, sí, pero lejos de apropiarse del territorio, sembrar la violencia y replicar sus prácticas delictivas en el lado europeo del Atlántico, su actividad ha podido ser controlada y no han llegado a suponer el grave problema social o criminal que se podía prever.Revista Policía y Seguridad Pública 5(1) 2015: 75-102
Las pandillas salvadoreñas y el delito de extorsión. Desafíos y prioridades en relación con el fenómeno extorsivo
Authors: Andrade Karla
Published: August 2015

El delito de extorsión en los últimos años ha cobrado relevancia para la sociedad, además de la que tiene en el ámbito policial e investigativo. La generación de ingresos económicos o en especies para las estructuras delincuenciales, particularmente para las pandillas/maras, así como las implicaciones en cuanto a peligrosidad y potencialidad, obligan a los organismos responsables de la seguridad pública al análisis y valoración integral del fenómeno extorsivo. Ello significa examinar las modalidades para su ejecución, los factores propiciadores y los escenarios delictivos; revisar el abordaje policial-fiscal, las implicaciones operativas, investigativas y judiciales de este, y los resultados alcanzados. Sin embargo, continúa siendo un desafío no solo institucional (para la Policía y la Fiscalía), sino que también para los actores clave y responsables de la toma de decisiones estratégicas de país.Revista Policía y Seguridad Pública 5(1) 2015: 103-148
Ley especial contra el delito de extorsión
Authors: Editor El
Published: August 2015

Revista Policía y Seguridad Pública 5(1) 2015: 423-430
Antibacterial and Chemical Properties of Chromatographic Fractions of Acidic Metabolites from Garcinia Kola Seed Extract
Authors: Uka Ogbuneke , C. Okoroiwu , L. Onu , U. Onyeocha , E. Ejele
Published: August 2015

Acidic metabolites were precipitated from ethanolic extract of Garcinia kola seed and fractionated by column chromatography to obtain three fractions AM1, AM2, and AM3. Chemical test on the acidic metabolites and the fractions showed they were mainly flavonoids. In vitro antibacterial screening of the fractions showed they possessed antibacterial activity. They inhibited the growth of five human test bacterial isolates: Coliform bacilli, Escherichia coli, Salmonella spp., Staphylococcus aureus and Streptococcus spp. Their inhibition zone diameters ranged from 8 mm to 26 mm. The standard control antibiotic Ciprofloxacin gave inhibition zone diameters ranging from 18 mm to 20 mm, at the same concentration of 100 mg/ml for the same test bacteria. It was concluded that with appropriate standardization, the three fractions from the acidic metabolites of ethanolic extract of seed of Garcinia kola could effectively complement the existing antibiotics with beneficial health effect.
Vierde Witwasrichtlijn aangenomen; wat wijzigt?
Authors: Snijder-Kuipers B. , Tilleman T.A.
Published: August 2015

Op 20 mei 2015 heeft het Europees Parlement de Vierde antiwitwasrichtlijn (hierna: Vierde Witwasrichtlijn) aangenomen. Uiterlijk juni 2017 dienen de lidstaten de bepalingen van de Vierde Witwasrichtlijn in nationale wetgeving te implementeren. Dat zal in Nederland tot aanpassing van de Wet ter voorkoming van witwassen en financieren van terrorisme leiden. Elke rechtspersoon is verplicht de ultimate beneficial owner, de uiteindelijk belanghebbende (UBO), in een nationaal register te registreren. In deze bijdrage worden de belangrijkste wijzigingen voor u op een rijtje gezet. Afgesloten wordt met enkele suggesties voor de wetgever en andere betrokkenen.

Richtlijn (EU) 2015/849 van het Europees Parlement en de Raad van 20 mei 2015 inzake de voorkoming van het gebruik van het financiële stelsel voor het witwassen van geld of terrorismefinanciering, tot wijziging van Verordening (EU) nr. 648/2012 van het Europees Parlement en de Raad en tot intrekking van Richtlijn 2005/60/EG van het Europees Parlement en de Raad en Richtlijn 2006/70EG van de Commissie, PbEU 2015, L 141/73 (Vierde Witwasrichtlijn).
De Europese Commissie en de nationale rechter in staatssteunzaken: welke mate van inhoudelijke toetsing?
Authors: van Herwijnen A.H.G.
Published: August 2015

In dit artikel wordt ingegaan op de verhouding tussen de Europese Commissie en de nationale rechter in staatssteunzaken. Er worden uiteenlopende ontwikkelingen vanuit twee staatssteunbeoordelende instanties gesignaleerd. De Europese Commissie legt meer verantwoordelijkheid voor de juiste naleving van de staatssteunregels bij de lidstaten neer, zodat zij zich kan concentreren op steunmaatregelen met mogelijk grote marktverstoring. Tegelijkertijd lijken de Nederlandse rechters een oordeel over eventuele staatssteun vaak uit de weg te gaan en evenmin veel gebruik te maken van de mogelijkheid om de Commissie om guidance te vragen.
Hof van Justitie ontwikkelt nieuwe visie op begrip handicap – en daarmee op non-discriminatierecht?
Authors: Hendriks A.C.
Published: August 2015

Sinds 1997 heeft de Raad van Ministers van de EU de bevoegdheid maatregelen te nemen ter bestrijding van discriminatie op grond van handicap. Maar wat wordt eigenlijk onder het begrip handicap verstaan? Het Hof van Justitie heeft deze term, zoals onder andere neergelegd in Richtlijn 2000/78/EG (hierna: Kaderrichtlijn) en het Handvest van grondrechten van de EU, via antwoorden op prejudiciële beslissingen nader geduid. Bestudering van deze jurisprudentie leert dat het Hof van Justitie het begrip handicap inmiddels anders interpreteert dat aanvankelijk het geval was. De omslag van een medische naar een meer sociale visie op het begrip handicap spreekt evident uit het recente arrest Kaltoft, het vervolg op de eerdere zaak HK Danmark. Deze nieuwe visie werkt door in de uitleg en toepassing van het Unierechtelijke verbod van discriminatie vanwege handicap en laat de gelijkebehandelingswetgeving in Nederland niet onberoerd.

HvJ 18 december 2014, zaak C-354/13, Karsten Kaltoft/Billund Kommune, ECLI:EU:C:2014:2463, n.n.g.
A evolução do conhecimento sobre a Província Ígnea do Paraná: dos primórdios até 1950
Authors: Licht Otavio Augusto Boni
Published: August 2015

O presente artigo resgata as pesquisas pioneiras sobre a Província Ígnea do Paraná e mostra que a acumulação do conhecimento científico foi iniciada de forma sólida a partir da metade do século XIX, quando estudos de campo identificaram a distribuição geográfica e a espessura do conjunto de rochas extrusivas, a faciologia dos derrames, a presença de rochas intrusivas, o contato transicional entre os primeiros derrames com os arenitos Botucatu, o modelo de vulcanismo fissural e a presença de rochas piroclásticas. Estudos de laboratório (geoquímica e petrografia) identificaram a presença de rochas de filiação básica e ácida, a zonalidade dos teores de ferro e do conteúdo em magnetita, eventos hidrotermais sin- e pós-magmáticos e seus produtos como zeólitas, pedras coradas e cobre. Com base nestas descobertas foi experimentada a correlação entre as províncias basálticas austrais para recompor o mosaico da "Terra de Gondwana".
Monitoring Cathodic Protection Reduces Corrosion Threat, Extends Asset Life
Authors: Balliew John E.
Published: August 2015

Corrosion of buried metal pipelines is a constant threat to water conservation. Through automation of its cathodic protection data‐collection activities, El Paso Water Utilities is providing continuous protection of its water storage tanks and transmission pipelines and minimizing lost water and main breaks.
Methods of Estimating Water End Use at US Army Installations
Authors: Jenicek Elisabeth M. , Garfinkle Noah W. , Curvey Laura E. , Case Michael P. , Choi Marianne , Stumpf Annette L.
Published: August 2015

The US Army is concerned about the multiple critical‐resource issues faced by its installations, with water being key among these resources. Adverse water issues include limited supply, rising cost, and impaired quality; strategies are needed to mitigate these undesirable effects. A major obstacle to developing strategies is the lack of detailed information about how Army facilities use water because on Army installations, water use is typically metered at the aggregate level rather than by area, function, or individual building. New research projects are focused on developing methods and models to disaggregate site‐level monthly water meter data and identify classes of facilities on the basis of function, equipment, and schedules of use. Draft methods were tested using information obtained from an installation water audit at Fort Leonard Wood, Mo. The outcomes of these models will help inform future conservation strategies as Army installations seek to reduce utility costs.
Opening Night et la remédiation théâtrale. « Film-balade » ou film « tragique » ?
Authors: Carrier-Lafleur Thomas
Published: August 2015

S’inspirant à la fois de la critique deleuzienne du « nouvel Hollywood » et de la dialectique métaphysique de l’apollinien et du dionysiaque telle que pensée par Nietzsche dansLa Naissance de la tragédie, nous souhaitons interroger ici quelques-uns des modes sur lesquels le théâtrehabitele cinéma. Par suite, afin de déplacer légèrement l’angle sous lequel on envisage habituellement l’adaptation et pour profiter ainsi d’un changement de point de vue, nous préfèrerons à la problématique du théâtre filmé le concept de « filmer le théâtre ». Nous explorerons celui-ci à partir d’une analyse du filmOpening Nightde John Cassavetes (1977), où la crise d’une actrice qui se trouve entre deux âges constitue, pour le réalisateur, et donc pour le septième art, une occasion de produire de la nouveauté théâtrale.
Desafios para a saúde coletiva no século XXI
Authors: Silva Paim Jairnilson
Published: August 2015

Esta coletânea reúne textos que discutem políticas públicas e movimentos ideológicos que têm influenciado o campo social da saúde. Nesta perspectiva, a saúde coletiva representa uma aposta em novos pressupostos, métodos e práticas sociais que podem compor movimentos capazes de constituir sujeitos públicos comprometidos com novos modos de vida.
Neuron-glia signaling in developing retina mediated by neurotransmitter spillover
Authors: Rosa Juliana M , Bos Rémi , Sack Georgeann S , Fortuny Cécile , Agarwal Amit , Bergles Dwight E , Flannery John G , Feller Marla B
Published: August 2015

Neuron-glia interactions play a critical role in the maturation of neural circuits; however, little is known about the pathways that mediate their communication in the developing CNS. We investigated neuron-glia signaling in the developing retina, where we demonstrate that retinal waves reliably induce calcium transients in Müller glial cells (MCs). During cholinergic waves, MC calcium transients were blocked by muscarinic acetylcholine receptor antagonists, whereas during glutamatergic waves, MC calcium transients were inhibited by ionotropic glutamate receptor antagonists, indicating that the responsiveness of MCs changes to match the neurotransmitter used to support retinal waves. Using an optical glutamate sensor we show that the decline in MC calcium transients is caused by a reduction in the amount of glutamate reaching MCs. Together, these studies indicate that neurons and MCs exhibit correlated activity during a critical period of retinal maturation that is enabled by neurotransmitter spillover from retinal synapses.
Emotions between physicality and acceptability. A Contrast of the German Anger Words Wut and Zorn
Authors:   Universitat Jaume I (España), Oster Ulrike
Published: August 2015

In this paper, a corpus-based approach is used in order to provide an in-depth analysis of two German emotion words (Wut and Zorn) that roughly correspond to the English lexical unit anger, establishing their similarities and differences on different levels of meaning. For the corpus study, data from two very large corpora of contemporary German texts (fiction, non-fiction, scientific and newspaper) are used, DWDS (Digitales Wörterbuch der deutschen Sprache des 20. Jhs.) and the collocation database CCDB, through which collocation profiles extracted from the German Reference Corpus (DeReKo). As a first step, the metaphorical and metonymical conceptualizations of both items are analysed and compared. Other aspects that are relevant for the description of these emotions and can be described by means of co-occurrence analysis are their conceptual proximity to other emotion words and the way they are described or evaluated (their semantic prosody). In a third step, looking at the semantic subsets the co-occurrences belong to from the point of view of syntagmatic relations between the emotion concept and its surroundings in the text (semantic preference), information can be extracted about causes of anger, about its consequences and about who experiences it. The results show that, taking both words together, the metaphorical conceptualization of the concept of anger proves to be very similar to that which has been described for other Western languages like English or Spanish. Going into more detail, however, the corpus analysis allows us to explore how each word specializes in certain aspects of the emotion and to corroborate, contradict or complement previous studies on this.
Alfabetización en escritura académica en Biología: propósitos comunicativos y niveles de alfabetización*
Authors:   Pontificia Universidad Católica de Valparaíso (Chile), Marinkovich Ravena Juana , Poblete Olmedo Claudia ,   Pontificia Universidad Católica de Valparaíso (Chile)
Published: August 2015

La alfabetización académica se ha convertido en un lugar común para las instituciones de educación superior en Latinoamérica. Un primer esfuerzo en este sentido lo constituyen las investigaciones que se han desarrollado con cada vez más fuerza y cantidad en lo que va transcurrido del presente siglo. En este contexto, el objetivo general que guía este estudio es determinar los niveles de alfabetización académica en escritura que se relevan a partir de los propósitos comunicativos presentes en los escritos de un grupo de estudiantes de primer año de la asignatura Morfofisiología: Función Animal, perteneciente a la licenciatura en Biología de una universidad del H. Consejo de Rectores de Chile. Específicamente, estos escritos responden a una tarea de escritura que se basa en el género “artículo de investigación” (AI) con el objeto de dar cuenta de un problema y resolverlo, siguiendo las etapas de una investigación en el área disciplinar. La metodología utilizada para llevar a cabo la investigación es de carácter cualitativo, aplicando para ello la técnica de análisis de contenido. Los resultados obtenidos permiten determinar que el nivel de alfabetización en escritura académica que predomina, aun cuando su porcentaje no sea significativo, es aquel que hemos denominado “explicativo”, al que le siguen el nivel “reproductivo”, “relacional”, “proactivo” y, finalmente, el “justificador”. Todos estos niveles corresponden a diversos propósitos comunicativos que emanaron de los segmentos textuales analizados, lo que muestra que los estudiantes se encuentran en un nivel inicial de alfabetización académica, tanto en lo científico como en lo escritural, pero que en lo que se refiere a la explicación existe un potencial que podrá ser desarrollado en las siguientes etapas de formación disciplinar.
Los comentarios escritos: género orientado a la consecución de otro género en el proceso de la escritura académica
Authors:   Universidad Católica de la Santísima Concepción (Chile), Tapia-Ladino Mónica
Published: August 2015

Comúnmente, cuando apoyamos el proceso de escritura de los estudiantes, los docentes dejamos consignadas anotaciones en sus escritos. Los comentarios escritos (CE) representan un género discursivo que presenta rasgos constantes a pesar de que los docentes y tutores no suelen recibir formación en este aspecto. Los CE constituyen un recurso dialógico orientado a guiar la escritura de los escritores que se adentran en el aprendizaje de un género nuevo. En este sentido, los CE son un género orientado a la apropiación de otro género discursivo por parte del escritor. Los CE son tipos de recursos de retroalimentación que ya cuentan con una tradición de investigación en inglés como primera y segunda lengua. El objetivo de este artículo monográfico es presentar las principales investigaciones que se han desarrollado en inglés sobre comentarios escritos y proponer un marco teórico explicativo desde la teoría de los géneros discursivos. Las investigaciones proveen información sobre los rasgos lingüísticos, discursivos y retóricos que caracterizan a los CE y las reacciones que producen en los estudiantes. Con ello, se focaliza en la idea de que los CE constituyen un rico campo de estudio que provee información sobre cómo un género, propio del proceso dialógico de escritura, favorece el aprendizaje de otro género
Tidally driven mixing and dissipation in the stratified boundary layer above steep submarine topography
Authors: Winters K. B.
Published: August 2015

A tidally driven, stratified boundary layer over supercritical topography is simulated numerically. The near‐boundary flow is characterized by quasiperiodic, bore‐like motions and episodic expulsion events where fluid is ejected into the stratified interior. The character of the bores is compared to the high‐resolution ocean mooring data of van Haren (2006). The diffusivity of the flow near the boundary is estimated by means of a synthetic dye tracer experiment. The average dissipation rate within the dye cloud is computed and combined with the diffusivity estimate to yield an overall mixing efficiency of 0.15. Both the estimated diffusivity and dissipation rates are in reasonable agreement with the microstructure observations of Kunze et al. (2012) when scaled to the environmental conditions at the Monterey and Soquel Canyons and to the values estimated by van Haren and Gostiaux (2012) above the sloping bottom of the Great Meteor Seamount in the Canary Basin.
Projected changes in extreme temperature events based on the NARCCAP model suite
Authors: Horton Radley M. , Coffel Ethan D. , Winter Jonathan M. , Bader Daniel A.
Published: August 2015

Once‐per‐year (annual) maximum temperature extremes in North American Regional Climate Change Assessment Program (NARCCAP) models are projected to increase more (less) than mean daily maximum summer temperatures over much of the eastern (western) United States. In contrast, the models almost everywhere project greater warming of once‐per‐year minimum temperatures as compared to mean daily minimum winter temperatures. Under projected changes associated with extremes of the temperature distribution, Baltimore's maximum temperature that was met or exceeded once per year historically is projected to occur 17 times per season by midcentury, a 28% increase relative to projections based on summer mean daily maximum temperature change. Under the same approach, historical once‐per‐year cold events in Baltimore are projected to occur once per decade. The models are generally able to capture observed geopotential height anomalies associated with temperature extremes in two subregions. Projected changes in extreme temperature events cannot be explained by geopotential height anomalies or lower boundary conditions as reflected by soil moisture anomalies or snow water equivalent.
Statistics and accuracy of magnetic null identification in multispacecraft data
Authors: Eriksson E. , Vaivads A. , Khotyaintsev Yu. V. , Khotyayintsev V. M. , André M.
Published: August 2015

Complex magnetic topologies are ubiquitous in astrophysical plasmas. Analyzing magnetic nulls, regions of vanishing magnetic field, is one way to characterize 3‐D magnetic topologies. Magnetic nulls are believed to be important in 3‐D reconnection and turbulence. In the vicinity of a null, plasma particles become unmagnetized and can be accelerated to high energies by electric fields. We present the first statistical study of the occurrence of magnetic nulls and their types in the Earth's nightside magnetosphere. We are able to identify the nulls both in the tail and in the magnetopause current sheets. On average, we find one null for every few current sheet crossings. We show that the type identification of magnetic nulls may be sensitive to local fluctuations in the magnetic field. We develop and demonstrate a method to estimate the reliability of the magnetic null type identification.
On the escape of CH4 from Pluto's atmosphere
Authors: Koskinen T. T. , Erwin J. T. , Yelle R. V.
Published: August 2015

We adapted a multispecies escape model, developed for close‐in extrasolar planets, to calculate the escape rates of CH4 and N2 from Pluto. In the absence of escape, CH4 should overtake N2 as the dominant species below the exobase. The CH4 profile depends strongly on the escape rate, however, and the typical escape rates predicted for Pluto lead to a nearly constant mixing ratio of less than 1% below the exobase. In this case the CH4 escape rate is only 5–10% of the N2 escape rate. Observations of the CH4 profile by the New Horizons/ALICE spectrograph can constrain the CH4 escape rate and provide a unique test for escape models.
Dynamics of large‐scale solar wind streams obtained by the double superposed epoch analysis
Authors: Yermolaev Yu. I. , Lodkina I. G. , Nikolaeva N. S. , Yermolaev M. Yu.
Published: August 2015

Using the OMNI data for period 1976–2000, we investigate the temporal profiles of 20 plasma and field parameters in the disturbed large‐scale types of solar wind (SW): corotating interaction regions (CIR), interplanetary coronal mass ejections (ICME) (both magnetic cloud (MC) and Ejecta), and Sheath as well as the interplanetary shock (IS). To take into account the different durations of SW types, we use the double superposed epoch analysis (DSEA) method: rescaling the duration of the interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide. As the analyzed SW types can interact with each other and change parameters as a result of such interaction, we investigate separately eights sequences of SW types: (1) CIR, (2) IS/CIR, (3) Ejecta, (4) Sheath/Ejecta, (5) IS/Sheath/Ejecta, (6) MC, (7) Sheath/MC, and (8) IS/Sheath/MC. The main conclusion is that the behavior of parameters in Sheath and in CIR are very similar both qualitatively and quantitatively. Both the high‐speed stream (HSS) and the fast ICME play a role of pistons which push the plasma located ahead them. The increase of speed in HSS and ICME leads at first to formation of compression regions (CIR and Sheath, respectively) and then to IS. The occurrence of compression regions and IS increases the probability of growth of magnetospheric activity.
Amplitude and recurrence time analysis of LP activity at Mount Etna, Italy
Authors: Cauchie Léna , Saccorotti Gilberto , Bean Christopher J.
Published: August 2015

The aim of this work is to improve our understanding of the long‐period (LP) source mechanism at Mount Etna (Italy) through a statistical analysis of detailed LP catalogues. The behavior of LP activity is compared with the empirical laws governing earthquake recurrence, in order to investigate whether any relationships exist between these two apparently different earthquake classes. We analyzed a family of 8894 events detected during a temporary experiment in August 2005. For that time interval, the LP activity is sustained in time and the volcano did not exhibit any evident sign of unrest. The completeness threshold of the catalogue is established through a detection test based on synthetic waveforms. The retrieved amplitude distribution differs significantly from the Gutenberg‐Richter law, and the interevent times distribution does not follow the typical γ law, expected for tectonic activity. In order to compare these results with a catalogue for which the source mechanism is well established, we applied the same procedure to a data set from Stromboli Volcano, where recurrent LP activity is closely related to very‐long‐period pulses, in turn associated with the summit explosions. Our results indicate that the two catalogues exhibit similar behavior in terms of amplitude and interevent time distributions. This suggests that the Etna's LP signals are most likely driven by stress changes caused by an intermittent degassing process occurring at depth, similar to that which drives the summit explosions at Stromboli Volcano.
Zonal jets in equilibrating baroclinic instability on the polar beta‐plane: Experiments with altimetry
Authors: Matulka A. M. , Afanasyev Y. D.
Published: August 2015

Results from the laboratory experiments on the evolution of baroclinically unstable flows generated in a rotating tank with topographic β‐effect are presented. We study zonal jets of alternating direction which occur in these flows. The primary system we model includes lighter fluid in the South and heavier fluid in the North with resulting slow meridional circulation and fast mean zonal motion. In a two‐layer system, the velocity shear between the layers results in baroclinic instability which equilibrates with time and, due to interaction with β‐effect generates zonal jets. This system is archetypal for various geophysical systems including the general circulation and jet streams in the Earth's atmosphere, the Antarctic Circumpolar Current, or the areas in the vicinity of western boundary currents where baroclinic instability and multiple zonal jets are observed. The gradient of the surface elevation and the thickness of the upper layer are measured in the experiments using the Altimetric Imaging Velocimetry and the Optical Thickness Velocimetry techniques, respectively. Barotropic and baroclinic velocity fields are then derived from the measured quantities. The results demonstrate that the zonal jets are driven by “eddy forcing” due to continuously created baroclinic perturbations. The flow is baroclinic to a significant degree and the jets are “surface intensified.” The meridional wavelength of the jets varies linearly with the baroclinic radius of deformation and is also in a good agreement with a modified Rhines scale. This suggests a linear dependence of the perturbation velocity in the equilibrated baroclinically unstable flow on the β‐parameter.
Study of the wind velocity‐layered structure in the stratosphere, mesosphere, and lower thermosphere by using infrasound probing of the atmosphere
Authors: Chunchuzov I. , Kulichkov S. , Perepelkin V. , Popov O. , Firstov P. , Assink J. D. , Marchetti E.
Published: August 2015

The wind velocity structure in the upper stratosphere, mesosphere, and lower thermosphere (MLT) is studied with the recently developed method of infrasound probing of the atmosphere. The method is based on the effect of infrasound scattering from highly anisotropic wind velocity and temperature inhomogeneities in the middle and upper atmosphere. The scattered infrasound field propagates in the acoustic shadow zones, where it is detected by microbarometers. The vertical profiles of the wind velocity fluctuations in the upper stratosphere (30–52 km) and MLT (90–140 km) are retrieved from the waveforms and travel times of the infrasound signals generated by explosive sources such as volcanoes and surface explosions. The fine‐scale wind‐layered structure in these layers was poorly observed until present time by other remote sensing methods, including radars and satellites. It is found that the MLT atmospheric layer (90–102 km) can contain extremely high vertical gradients of the wind velocity, up to 10 m/s per 100 m. The effect of a fine‐scale wind velocity structure on the waveforms of infrasound signals is studied. The vertical wave number spectra of the retrieved wind velocity fluctuations are obtained for the upper stratosphere. Despite the difference in the locations of the explosive sources all the obtained spectra show the existence of high vertical wave number spectral tail with a −3 power law decay. The obtained spectral characteristics of the wind fluctuations are necessary for improvement of gravity wave drag parameterizations for numerical weather forecast.
Aerosol‐induced mechanisms for cumulus congestus growth
Authors: Sheffield Amanda M. , Saleeby Stephen M. , van den Heever Susan C.
Published: August 2015

Tropical convection has been observed to contain three cloud modes, the middle of which is cumulus congestus clouds. Congestus clouds act to moisten the tropical atmosphere, may be mixed‐phase, and on occasion surpass the freezing level inversion from where they may develop into deeper convection. This study investigates the impacts of enhanced aerosol concentrations on the growth of congestus clouds produced in idealized cloud‐resolving model simulations run under a state of radiative convective equilibrium (RCE). High‐resolution, long‐duration simulations were completed using the Regional Atmospheric Modeling System (RAMS). Aerosol concentrations between 2 and 4 km above ground level were varied from clean to polluted conditions in order to represent the advection of Saharan dust over the Atlantic Ocean. The congestus populations within each aerosol simulation are statistically analyzed using 10 days of model output after the simulation reaches RCE. Results indicate that congestus in more polluted conditions produce greater amounts of cloud water and ice mass, enhanced updraft strengths, and an increase in the number of congestus cloud tops that extend above the freezing level. Enhanced vapor depositional growth on the populations of more numerous, smaller cloud droplets in the polluted conditions, and the subsequent increase in latent heat release in the warm phase regions of the cloud, is found to be important factors in convective invigoration of these cloud systems. Aerosol feedbacks associated with cold pools and condensate loading also influence the updraft strength and act in opposition to the warm phase invigoration processes.
Joint assimilation of eddy covariance flux measurements and FAPAR products over temperate forests within a process‐oriented biosphere model
Authors: Bacour C. , Peylin P. , MacBean N. , Rayner P. J. , Delage F. , Chevallier F. , Weiss M. , Demarty J. , Santaren D. , Baret F. , Berveiller D. , Dufrêne E. , Prunet P.
Published: August 2015

We investigate the benefits of assimilating in situ and satellite data of the fraction of photosynthetically active radiation (FAPAR) relative to eddy covariance flux measurements for the optimization of parameters of the ORCHIDEE (Organizing Carbon and Hydrology in Dynamic Ecosystem) biosphere model. We focus on model parameters related to carbon fixation, respiration, and phenology. The study relies on two sites—Fontainebleau (deciduous broadleaf forest) and Puechabon (Mediterranean broadleaf evergreen forest)—where measurements of net carbon exchange (NEE) and latent heat (LE) fluxes are available at the same time as FAPAR products derived from ground measurements or derived from spaceborne observations at high (SPOT (Satellite Pour l′Observation de la Terre)) and medium (MERIS (MEdium Resolution Imaging Spectrometer)) spatial resolutions. We compare the different FAPAR products, analyze their consistency with the in situ fluxes, and then evaluate the potential benefits of jointly assimilating flux and FAPAR data. The assimilation of FAPAR data leads to a degradation of the model‐data agreement with respect to NEE at the two sites. It is caused by the change in leaf area required to fit the magnitude of the various FAPAR products. Assimilating daily NEE and LE fluxes, however, has a marginal impact on the simulated FAPAR. The results suggest that the main advantage of including FAPAR data is the ability to constrain the timing of leaf onset and senescence for deciduous ecosystems, which is best achieved by normalizing FAPAR time series. The joint assimilation of flux and FAPAR data leads to a model‐data improvement across all variables similar to when each data stream is used independently, corresponding, however, to different and likely improved parameter values.
Translation Initiation Models in Prokaryotes and Eukaryotes
Authors: Londei Paola
Published: August 2015

Translation is one stage of protein synthesis in which messenger ribonucleic acid (
mRNA
) acts as a template for the synthesis of a polypeptide chain; it consists of four phases: initiation, elongation, termination and ribosome recycling. Initiation of protein synthesis, entailing ribosomal recognition of the
mRNA
start codon and the setting of the correct reading frame, is the rate‐limiting step of translation and the main target of translation regulation in all cells. However, the mechanism and molecular machinery for initiation have diverged in the primary domains of life: the Bacteria, the Archaea and the Eukarya (eukaryotes). In bacteria, translation initiation is relatively simple, whereas in eukaryotes, it is complex and requires more components. In archaea, despite their prokaryotic phenotype, the machinery for protein synthesis initiation is much more elaborated than in bacteria and presents intriguing similarities with the corresponding eukaryotic process. The features of translational initiation in archaea, bacteria and eukaryotes are reviewed, highlighting the divergent and common aspects of this important cellular process in the three domains of life.

Key Concepts

Initiation is the first of four steps of the translation cycle. During initiation, the small ribosomal subunit interacts with the messenger ribonucleic acid (mRNA) and finds the right start codon, thereby setting the correct reading frame for decoding.

In all cells, translation initiation is assisted and modulated by several proteins called translation initiation factors (IFs). The most important roles of the IFs are to select the proper initiator transfer RNA, adjust it correctly in the ribosomal P site, ensure the accurate selection of the start codon and prevent the premature joining of the large ribosomal subunit to the pre‐initiation complex.

Initiation is the rate‐limiting step of translation. It is the efficiency whereby an mRNA is decoded and the amount of final product is largely determined at the initiation level.

In all cells, the principal mechanisms of translational control act at the level of initiation, usually targeting certain IFs that play essential roles in the initiation process.

The initiation step of translation has incurred a marked evolutionary divergence. The mechanism and components of initiation differ in several aspects in the three primary domains of life, that is, the Bacteria, the Archaea and the Eukaryotes.

The Bacteria have the simplest machinery for translation initiation. However, this is not because they are prokaryotes. The other prokaryotic domain, the Archaea, has a fairly complex machinery for initiation, resembling that of eukaryotes, which have the most complex initiation process.