bluuebunny/crossref_metadata_2025 huggingface dataset:
Decadal and long-term boreal soil carbon and nitrogen sequestration rates
across a variety of ecosystems
Authors: Manies Kristen L. , Harden Jennifer W. , Fuller Christopher C. , Turetsky Merritt R.
Published: July 2018

Abstract. Boreal soils play a critical role in the global carbon (C) cycle; therefore, it is important to understand the mechanisms that control soil C accumulation and loss for this region. Examining C & nitrogen (N) accumulation rates over decades to centuries may provide additional understanding of the dominant mechanisms for their storage, which can be masked by seasonal and interannual variability when investigated over the short term. We examined longer-term accumulation rates, using 210Pb and 14C to date soil layers, for a wide variety of boreal ecosystems: a black spruce forest, a shrub ecosystem, a tussock grass ecosystem, a sedge-dominated ecosystem, and a rich fen. All ecosystems had similar decadal C accumulation rates, averaging 84 ± 42 gC m−2 yr−1. Long-term (century) C accumulation rates were slower than decadal rates, averaging 14 ± 5 gC m−2 yr−1 for all ecosystems except the rich fen, for which the long-term C accumulation rates was more similar to decadal rates (44 ± 5 and 76 ± 9 gC m−2 yr−1, respectively). The rich fen also had the highest long-term N accumulation rates (2.7 gN m−2 yr−1). The lowest N accumulation rate, on both a decadal and long-term basis, was found in the black spruce forest (0.2 and 1.4 gN m−2 yr−1, respectively). Our results suggest that the controls on long-term C and N cycling at the rich fen is fundamentally different from the other ecosystems, likely due to differences in the predominant drivers of nutrient cycling (oxygen availability, for C) and reduced amounts of disturbance by fire (for C and N). This result implies that most shifts in ecosystem vegetation across the boreal region, driven by either climate or succession, will not significantly impact regional C or N dynamics over years to decades. However, ecosystem transitions to or from a rich fen will promote significant shifts in soil C and N storage.
Streamflow variability over the 1881–2011 period in northern Québec: comparison of hydrological
reconstructions based on tree rings and geopotential height
field reanalysis
Authors: Brigode Pierre , Brissette François , Nicault Antoine , Perreault Luc , Kuentz Anna , Mathevet Thibault , Gailhard Joël
Published: July 2018

Abstract. Over the last decades, different methods have been used by hydrologists to extend observed hydro-climatic time series, based on other data sources, such as tree rings or sedimentological datasets. For example, tree ring multi-proxies have been studied for the Caniapiscau Reservoir in northern Québec (Canada), leading to the reconstruction of flow time series for the last 150 years. In this paper, we applied a new hydro-climatic reconstruction method on the Caniapiscau Reservoir and compare the obtained streamflow time series against time series derived from dendrohydrology by other authors on the same catchment and study the natural streamflow variability over the 1881–2011 period in that region. This new reconstruction is based not on natural proxies but on a historical reanalysis of global geopotential height fields, and aims firstly to produce daily climatic time series, which are then used as inputs to a rainfall–runoff model in order to obtain daily streamflow time series. The performances of the hydro-climatic reconstruction were quantified over the observed period, and showed good performances, in terms of both monthly regimes and interannual variability. The streamflow reconstructions were then compared to two different reconstructions performed on the same catchment by using tree ring data series, one being focused on mean annual flows and the other on spring floods. In terms of mean annual flows, the interannual variability in the reconstructed flows was similar (except for the 1930–1940 decade), with noteworthy changes seen in wetter and drier years. For spring floods, the reconstructed interannual variabilities were quite similar for the 1955–2011 period, but strongly different between 1880 and 1940. The results emphasize the need to apply different reconstruction methods on the same catchments. Indeed, comparisons such as those above highlight potential differences between available reconstructions and, finally, allow a retrospective analysis of the proposed reconstructions of past hydro-climatological variabilities.
Muographic data analysis method for medium-sized rock overburden inspections
Authors: Tanaka Hiroyuki K. M. , Ohshiro Michinori
Published: July 2018

Abstract. Muographic measurements of rock overburdens are of particular interest because they can be applied to natural resources and undiscovered cave explorations, and even to searching for hidden chambers in historic architectural structures. In order to derive the absolute density distribution of the overburden, we conventionally needed to know accurate information about the measurement conditions, e.g., the detector's geometrical acceptance, detection efficiency, and measurement time, in order to derive the absolute value of the transmitted muon flux. However, in many cases, it is not a simple task to accurately gauge such conditions. Open-sky muon data taken with the same detector are useful as reference data to cancel these factors; however, if the detector is not transportable, this data taking method is not feasible. In this work, we found that the transmitted muon flux will follow a simple function of the areal density along the muon path as long as the incident muon energies are below a few hundred GeV. Based on this finding, we proposed a simple analysis method that does not require detailed knowledge of the detector's conditions by combining the independently measured density information for the partial volume of the target. We anticipate that this simple method is applicable to future muographic measurements of rock overburdens.
Comparison of adjoint and nudging methods to initialise ice sheet model basal conditions
Authors: Mosbeux Cyrille , Gillet-Chaulet Fabien , Gagliardini Olivier
Published: July 2018

Abstract. Ice flow models are now routinely used to forecast the ice sheets' contribution to 21st century sea-level rise. For such short term simulations, the model response is greatly affected by the initial conditions. Data assimilation algorithms have been developed to invert for the friction of the ice on its bedrock using observed surface velocities. A drawback of these methods is that remaining uncertainties, especially in the bedrock elevation, lead to non-physical ice flux divergence anomalies resulting in undesirable transient effects. In this study, we compare two different assimilation algorithms based on adjoints and nudging to constrain both bedrock friction and elevation. Using synthetic twin experiments with realistic observation errors, we show that the two algorithms lead to similar performances in reconstructing both variables and allow the flux divergence anomalies to be significantly reduced.
Understanding For-Profit Higher Education in the United States Through History, Criticism, and Public Policy: A Brief Sector Landscape Synopsis
Authors: Hodgman Matthew R.
Published: July 2018

Despite their uniquely innovative and long-standing history within the United States higher education landscape, for-profit higher education institutions (FPHEIs) remain controversial academic entities. Criticism of the for-profit sector maintains that these institutions are not preparing students for successful entry into the workforce. In light of numerous recent struggles, sector growth has significantly receded while FPHE practices and policies continue to be questioned. In the wake of sector decline, FPHEIs have an important opportunity to reimagine their role as educational providers to better serve students and society at large. At this critical transitional moment, this article briefly reviews the literature surrounding the overall FPHE landscape to date in terms of the historical background of the sector, criticisms leveled against FPHE, and important public policies surrounding the for-profit sector. Gaps in the FPHE landscape literature are noted and suggestions for additional sector research are offered with respect to generating future scholarship that may be useful when (re)considering the role that FPHEIs might assume going forward.
Elsa Ramos : no hay nada que detenga la migración, mientras no se solucionen las causas estructurales que la generan
Authors: Ramírez de Clará Inés
Published: July 2018

A mediados de la pasada década, precisamente en el año 2005, la Universidad Tecnológica de El Salvador (Utec) inició formalmente a trabajar en el tema de migración a partir de una invitación que recibió del Programa de las Naciones Unidas para el Desarrollo, que consistía en cooperar en la elaboración del primer capítulo del Informe de Desarrollo Humano del mismo año. Desde esa investigación se partió para realizar otras y se visualizó el impacto que tiene para la sociedad salvadoreña dicho tema, pues este no tiene partido político, religión, clase social ni edad, según Elsa Ramos, investigadora de la Vicerrectoría de Investigación y Proyección Social de la Utec, que concedió una entrevista para conversar sobre migración para revista entorno.Entorno, diciembre 2015, número 60: 7-9
Las personas migrantes desaparecidas y sus familiares
Authors: (CICR) Comité Internacional de la Cruz Roja
Published: July 2018

Los familiares de personas migrantes desaparecidas sufren distintas afectaciones en su vida a raíz de la desaparición de su ser querido. Por encima de todo, necesitan que se busque a su familiar, averiguar dónde se encuentra y qué le ha ocurrido. Esto se manifiesta claramente en sus prioridades, a las que se suman otras necesidades derivadas de la desaparición de carácter económico, psicológico, legal, administrativo y de reconocimiento de su situación.Debido a la ausencia de rutas de atención claras y procedimientos sistemáticos por parte de las autoridades, existe una gran atomización en las prácticas de búsqueda. Las familias se ven obligadas a contactar distintas instancias, e incluso a repetir trámites presentando nuevamente la misma información y documentación ante la misma autoridad. Lo anterior ocasiona un alto riesgo de re-victimización para las familias, así como el incremento de los gastos generados por la búsqueda.El Comité Internacional de la Cruz Roja (CICR) considera que el fenómeno de la desaparición de personas migrantes trasciende las fronteras de los países implicados, por lo que propone un enfoque regional para abordarlo. Las autoridades deben no solo tomar medidas en cada uno de los ámbitos nacionales, sino también coordinarlas a escala regional.Entorno, diciembre 2015, número 60: 25-31
Development of a Method for Simultaneous Determination of Two Stilbenes and Four Anthraquinones from Polygonum Cuspidatum by RP-HPLC
Authors: Yan Jianye , Wang Yuanqing , Wu Hongnian , Sun Zhicheng , Tan Shihan , Wang Wei , Gong Limin , Xia Xinhua , Li Shunxiang
Published: July 2018

Background: Polygonum Cuspidatum Sieb. et Zucc. (named Huzhang in China) is a traditional and popular Chinese medicinal herb used in removing jaundice, clearing heat-toxin, improving blood circulation, expelling stasis, dispelling wind and dampness, repelling phlegm, and suppressing cough. It is widely used in drug and functional food fields and distributed throughout the world, including in China, Japan, and North America. Objective: To control the quality of Polygonum Cuspidatum, an effective, reliable, and simple method for simultaneous determination of two stilbenes (polydatin, resveratrol) and four anthraquinones (emodin, physcion, rhein, and anthraglycoside B) was developed and validated for the first time in this study by reversed-phase HPLC (RP-HPLC). Methods: Separation was carried out on Agilent C18 column (250 × 4.6 mm I.D., 5 μm) with acetonitrile and 0.10% aqueous phosphoric acid as mobile phase and gradient elution at a flow rate of 0.8 mL/min. Detection was conducted with mobile wavelength at 30°C. Results: Good validation of the method including linearity, precision, repeatability, and recovery was performed. The contents of the studied analytes are significantly different, and resveratrol and rhein in particular existed in greater fluctuation among the samples. Conclusion: A simple, reliable, and sensitive method has been successfully established and applied to the analysis for simultaneous determination of the target compounds in 11 batches of samples. Highlights: Separation and quantitative analysis of two stilbenes and four anthraquinones from P. cuspidatum were developed by RP-HPLC. This method is convenient, sensitive, and accurate and can provide a reliable basis for further applications of P. cuspidatum in drug or food fields.
Quantitative Detection of Chicken and Turkey Contamination in Cooked Meat Products by ELISA
Authors: Thienes Cortlandt P , Masiri Jongkit , Benoit Lora A , Barrios-Lopez Brianda , Samuel Santosh A , Meshgi Mahzad A , Cox David P , Dobritsa Anatoly P , Nadala Cesar , Samadpour Mansour
Published: July 2018

Background: Concerns about the contamination of meat products with undeclared meats and new regulations for the declaration of meat adulterants have established the need for a rapid test to detect chicken and turkey adulteration. Objective: To address this need, Microbiologique, Inc. has developed an ELISA that can quantify the presence of chicken and turkey down to 0.1% (w/w) in cooked pork, horse, beef, goat, and lamb meats. Results: This chicken/turkey authentication ELISA has an analytical sensitivity of 0.000037% and 0.000048% (w/v) for cooked andautoclaved chicken, respectively, and an analyticalrange of quantitation of 0.025–2% (w/v), in the absence of other meats. The assay cross-reacts with cooked duck and pheasant but does not demonstrate any cross-reactivity with cooked pork, horse, beef, goat, and lamb meats, egg, or common food matrixes. Conclusions: The assay is rapid, can be completed in 70 min, and can detect a 0.1% level of meat adulteration. Highlights: The Microbiologique Cooked Chicken/TurkeyELISA can quantitate cooked chicken/turkey in the presence of pork, horse, chicken, goat, or sheep meat to 0.1% (w/w) and is not affected by common food matrixes.
Effect of plant growth-promoting rhizobacterial composite culture on the growth of chickpea seedlings
Authors: Nag Jitendra , Dash Biplab , Singh Anup Kumar , Chowdhury Tapas , Gupta Shyam Bihari , Soni Ravindra
Published: July 2018

In the present study, 20 soil and plant samples from 13 villages of Raipur, Durg, and Balod District of Chhattisgarh (India) were collected from chickpea fields. From these samples, a total of 86 isolates including 16 Rhizobium, 40 Azotobacter, 29 Azosprillum, and one PSB were obtained on selective culture media. All the isolates were screened for their plant growth-promoting traits. Three (GmR8, ASL3 & ASL4) out of 86 were finally selected for further studies. One Azotobacter isolate, i.e., Azo137, was selected from the departmental culture collection. Finally, four isolates including GmR8 (Rhizobium), ASL3, ASL4 (Azospirillum), and Azo137 were selected for composite culture formulations. GmR and ASL4 were siderophore-producing isolates, whereas ASL3 and Azo137 were IAA producer along with their ability to fix nitrogen. Five composite cultures were prepared randomly and tested for effect on the growth of chickpea (the seedling test and the pot experiment). Among all the composite culture groups, C2 (GmR8, Azo137, ASL4) significantly increased the root (10.84 cm) and shoot (8.10 cm) length, whereas biomass (3.60 g) was the highest in the case of C1 (GmR8, Azo137, ASL3, ASL4) of seedlings as compared to the control (6.80 cm, 2.60 cm, and 3.30 g, respectively). Overall, the study revealed a better performance of composite or mixed culture over individual bacteria.
Phytotoxicity and allelopathic impact of Impatiens glandulifera
Authors: Baležentienė Ligita
Published: July 2018

The knowledge of how invasive species spread in a new environment might be important for their management control. Moreover, biochemical interaction underlies the novel weapon hypothesis thus presenting one of numerous explanations for species invasiveness. This study aimed to determine the total phenolics content in various parts of I. glandulifera and evaluate their phytotoxicity on the germination of monocot and dicot species. Phytotoxicity and allelopathic activity of worldwide invasive Impatiens species (Balsaminaceae) I. glandulifera (originated in the Himalayas) on wheat and rapeseed germination and seedling growth was assessed ex situ at Aleksandras Stulginskis University in 2016. The phenolic content ranged between 0.615 and 7.566 mg g–1 in Impatiens extracts, however, it significantly inhibited germination and seedling growth of the recipient species. Seed germination and seedling emergence are the outcomes of a sequence of biological events initiated by water imbibition followed by enzymatic metabolism of storage nutrients. The recorded germination rate was different for each recipient species. Inhibition of Impatiens extracts was recorded stronger for rapeseed germination (11.5– 81%) than that for wheat germination (71–86.5%), possibly due to different seed coat anatomy and thus its permeability. Therefore the strongest inhibition (86.5%) was recorded for rapeseed germination (11.5%) in 0.2% fruit + seed extract of I. glandulifera. Mean length of wheat hypocotyl (14.2 mm) and radicle (4.4 mm) exhibited a weaker response to the extract of I. glandulifera than rapeseed (4.4 mm and 1.4 mm, respectively). Consequently, recruitment and regeneration of native species might be negatively affected by the invasive Impatiens species in invaded habitats.
Effect of ionized water and stratification on the condition of Allium ursinum L. seeds
Authors: Malinauskaitė Regina , Šaluchaitė Aurelija
Published: July 2018

One of the rarer problems that occur in growing medicinal and spice plants is ensuring the quality of the propagating material. Germination of seeds of one of these plants, Allium ursinum L., is slow. To improve that, stratification is used. In the experiment, which was carried out in Lithuania in 2016, evaluation of fourand five-week long stratification and the use of alkaline ionized (pH 8.6) water for germination affect for Allium ursinum L. seeds were evaluated. It was found that the above-mentioned intervals for stratification did not affect the beginning of seed germination. Furthermore, one of the possible reasons for slower germination was found, and it was the incidence of seed diseases caused by fungi and bacteria. Allium ursinum L. seeds were affected the most by Penicillium ssp. micromycetes. The longer the period of stratification, the more alkaline ionized water decreased the effect of Mucor ssp. micromycetes.
Bedside stratification of patients according to CYP2C19*2 genotype
Authors: Karaliūtė Rasa , Gustienė Olivija , Kupstytė Nora , Ambrasienė Daiva , Tatarūnas Vacis
Published: July 2018

Objective. The task was to identify the defective CYP2C19*2 allele by using a novel fast-genotyping method in the patients having coronary artery disease who developed stent thrombosis or high on-treatment platelet reactivity.
Materials and methods. A total of 35 patients were included in the study. All the patients were screened for CYP2C19*2 using Spartan RX CYP2C19 Assay Package.
Results. CYP2C19*1*1 variant was found in 63%, *1*2 in 34%, *2*2 in 3% of patients. The distribution of genotypes was similar in men and women.
Conclusions. By using the bedside technique, CYP2C19*2, which is responsible for a poorer effect of clopidogrel, might be identified in less than an hour.
Creatividad en el diseño de instrumentos de recogida de datos: Las preferencias espaciales experimentadas por escolares
Authors: Alonso-Sanz Amparo
Published: July 2018

La experimentación del entorno escolar por parte de los escolares, y la reflexión sobre las sensaciones provocadas por los estímulos que alberga; son de interés para determinar la calidad estética de los centros educativos. Son necesarios nuevos instrumentos de recogida de datos que permitan aproximarse a las voces de los escolares de temprana edad. A partir de la Investigación basada en las Artes y mediante técnicas de fomento de la creatividad proponemos un instrumento que combina: la observación participante, como forma de acercamiento; la entrevista y el lenguaje visual para la expresión de respuestas; y el análisis documental por categorías, para la obtención de información.
El estudio muestra los resultados de una investigación plural, desarrollado en 3 escuelas de la ciudad de Alicante, y categoriza los lugares preferentes entre el alumnado infantil. Las conclusiones demuestran la relación entre el placer estético, las actividades pedagógicas estimulantes a nivel sensorial y el entorno educativo.
Desde la inquietud y creación artística, hacia reflexiones desde las prácticas educativas no formales.
Authors: Altuna Lizarraga Maria , Guerra Guezuraga Regina
Published: July 2018

Este artículo muestra las reflexiones de las autoras en torno a su propia práctica docente. El camino que recorren desde su inquietud y creación artística, pasando por la educación (como estudiantes y como docentes no académicas), hasta sus fases como investigadoras en educación artística.
Las autoras quieren visibilizar los momentos de tensión y las dificultades que han tenido que pasar en sus prácticas educativas, pero al mismo tiempo el conocimiento que han generado mediante estas experiencias que les sirven para crearse una identidad híbrida donde pueden cuestionarse su propia práctica en relación al arte. Para dar forma y poder analizar en profundidad las experiencias, estas estarán catalogadas en las tres fases que Paul Klee(1979) utiliza para describir el proceso de creación, que en este caso será para dar sentido al proceso de aprendizaje de la práctica docente.
Por lo tanto, el artículo presentará un carácter dialógico, ya que las reflexiones se representarán a modo de conversación cruzada entre las autoras, para así mostrar las realidades que rodean a la educación artística no académica.
La práctica artística contemporánea como experiencia interdisciplinar abierta al aprendizaje transversal.
Authors: González Ricardo
Published: July 2018

En el presente artículo se muestran las bases para considerar el arte contemporáneo como una experiencia interdisciplinar, que puede reunir saberes provenientes de otros campos del conocimiento. Asimismo, partiendo del determinismo tecnológico que establece nuestra era, se prioriza el papel fundamental que poseen los discursos acerca de los medios en este contexto. Estas son las premisas que nos conducen a la consideración del diálogo establecido entre arte y educación actualmente, a partir de lo que algunos autores han denominado como “giro educativo en el arte”. Para demostrar esta nueva realidad, destacamos algunos proyectos propuestos por determinados centros de arte que debaten sobre ese binomio, además de señalar cómo las experiencias de arte colaborativo pueden representar modelos abiertos a un aprendizaje transversal del que se pueden beneficiar los componentes de aquellas comunidades donde éstos se desarrollan.
El dibujo de un esquema pedagógico: La creatividad y la transversalidad como eje fundamental en las artes
Authors: Sáez Pradas Fernando
Published: July 2018

Con el cambio en los nuevos planes de estudios y la aparición de nuevas titulaciones en el ámbito de las artes, han surgido numerosas dudas sobre la eficacia de los programas curriculares así como de las metodologías docentes empleadas. Se ha cuestionado y se cuestiona el rol que ha de tener el educador y el papel que juegan aspectos hasta hace poco denostados, o no tenidos en cuenta en el desarrollo educativo, como las redes sociales. La adaptación del profesorado a unos planes de estudios mucho más exigentes ha puesto de manifiesto ciertos vacíos que han de ser solventados cuanto antes. La creatividad debería ser el eje cardinal de la educación artística sea cual sea la disciplina, así como la transversalidad, elemento imprescindible a tener en cuenta en el aprendizaje de las artes. Uno de los ejemplos que hemos tenido en cuenta ha sido el del artista Joseph Beuys, así como los modelos de la Bauhaus y la Black Mountain College.
Interdisciplinariedad y tecnología en la educación artística desde la experiencia creativa
Authors: Martín-Piñol Carolina , Calderón-Garrido Diego , Gustems-carnicer Josep
Published: July 2018

Aunque la educación interdisciplinaria es cada vez más necesaria, muchos planes docentes en los grados de formación de maestros no contemplan ninguna materia planteada de dicho modo. Una posible solución a esta problemática es fomentar acciones de enseñanza-aprendizaje desde diversas materias y asignaturas universitarias del mismo grado. En el presente artículo se muestra una acción realizada en la Universidad de Barcelona que implica dos materias artísticas y la coordinación entre varios profesores de diversas áreas con el objetivo de mostrar un modelo de actuación didáctica que desarrolla habilidades y fomente competencias relacionadas con el arte y la música ensamblándolas a través de las nuevas tecnologías de la información. La experiencia se inició en el segundo año de carrera acabándose un curso más tarde. Los resultados muestran una gran aceptación y motivación por parte del alumnado que se vio envuelto en un proceso creativo y experimental en el que la narrativa audiovisual y el DIY sirvieron de hilo conductor.
Estrategias metodológicas de aprendizaje cooperativo y de producción artística en la universidad.
Authors: Ortuño Pedro
Published: July 2018

El presente artículo analiza dos proyectos de creación artística llevados a cabo en la universidad con metodologías de aprendizaje cooperativo. A partir del planeamiento innovador propuesto por Irit Rugoff, se analizan dos proyectos artísticos desarrollados desde esta perspectiva, llevados a cabo por estudiantes de la Universidad de Murcia y de la Universidad de Beira Interior en Portugal. Durante su desarrollo se promueven procesos de construcción del aprendizaje, de tutorización de iguales, de andamiaje, de aprender a aprender...
En el caso del alumnado de la universidad de Murcia, el resultado fue un audiovisual colaborativo en el que participaron, tanto en su gestación como en su desarrollo, varias asociaciones representativas del barrio de La Paz. Y en el segundo proyecto, los alumnos portugueses crearon un interactivo multimedia, también llamado webdoc. En ambos casos se constata la eficacia del planteamiento inicial, tanto por el grado de satisfacción del docente y de los alumnos, como por la alta autogestión en el aprendizaje realizado.
Jugando con el arte moderno
Authors: Jaume Adrover Magdalena
Published: July 2018

El arte moderno es el único que ha sabido dirigir una mirada estética a la existencia infantil, apropiándose de sus procesos de experimentación.
Las vanguardias artísticas acamparon en un territorio previo al lenguaje, donde todos los sentidos perceptivos se conservan atentos, a la descubierta de un mundo sin nombres –los nombres cubren al mundo; para des-cubrir al mundo hay que apartar los nombres.
Porque donde hay lenguaje no cabe lugar para el arte: para poder privilegiar la percepción, el arte necesita desvincularse de lo lingüístico, de la comunicación codificada, del sistema establecido entre quien emite y quien recibe un comunicado; de quien, al mirar, simplemente reconoce.
En arte la percepción es un fin en sí mismo; arte es el procedimiento que busca la percepción reflexiva, y sólo surge cuando se bloquea y obstaculiza el acto comunicativo, cuando se prolonga el acto perceptivo. ¿Dónde encontrar ese estadio previo al lenguaje, en el que puede surgir el arte?
Está en el niño que descubre un mundo repleto de cosas sin nombre. El arte moderno es un niño que juega, y que propone, a quien antes estaba condenado a ser espectador, a participar en el juego.
Rational Energy Band Alignment and Au Nanoparticles in Surface Plasmon Enhanced Si‐Based Perovskite Quantum Dot Light‐Emitting Diodes
Authors: Liu Jingjing , Zhang Xianju , Ji Yang , Sheng Xuexi , Ma Haiguang , Xu Xiangxing , Yu Linwei , Xu Jun , Chen Kunji
Published: July 2018

Combining inorganic perovskite quantum dots (IPQDs) devices with Si platform is an interesting topic since it is helpful for realizing the optoelectronic integration as well as the multiple‐functional electronics in a compact and lightweight format. However, the poor energy band alignment between the IPQDs and Si limits the device performance, such as the emitting efficiency. Here, a light‐emitting diodes (LEDs) structure is proposed by inserting a poly‐TPD (poly[N,N′‐bis(4‐butylphenyl)‐N,N′‐bis(phenyl)‐benzidine]) layer between the n‐type IPQDs and the p‐type Si substrate. The light‐emitting diode based on CsPbI3 quantum dots reaches an output power density of 1.68 mW cm−2 with external quantum efficiency of 0.91%, which is enhanced by 34‐fold compared with the reference device. Similar emission enhancement is also observed in the device based on CsPbBr3 quantum dots but the output power density is only 0.6 mW cm−2. In order to further improve the emission intensity of CsPbBr3 quantum dots devices, Au nanoparticals (Au NPs) are introduced into the hole injection layer, the output power density increases to 1.2 mW cm−2, which is induced by the localized surface plasmon resonance coupling between Au NPs and CsPbBr3 excitons. The results demonstrate that high‐efficiency and stable Si‐based perovskite LEDs can be realized by rational optical and electronic design.
A Silver Nanocluster Containing Interstitial Sulfur and Unprecedented Chemical Bonds
Authors: Liu Xu , Chen Jishi , Yuan Jinyun , Li Yizhi , Li Jin , Zhou Shiming , Yao Chuanhao , Liao Lingwen , Zhuang Shengli , Zhao Yan , Deng Haiteng , Yang Jinlong , Wu Zhikun
Published: July 2018

The emergence of thiolated metal nanoclusters provides opportunities to identify significant and unprecedented phenomena because they are at quantum sizes and can be characterized with X‐ray crystallography. Recently silver nanoclusters have received extensive interest owing to their merits, such as low‐cost and rich properties. Herein, a thiolated silver nanocluster [Ag46S7(SPhMe2)24]NO3 (Ag46 for short) with a face‐centered cubic (fcc) structure was successfully synthesized and structurally resolved by X‐ray analysis. Most importantly, interstitial sulfur was found in the lattice void of Ag46 without lattice distortion or expansion, indicating that the classic theory of interstitial metal solid solutions might be not applicable at quantum size. Furthermore, unprecedented chemical bonds and unique structural features (such as asymmetrically coordinated μ4‐S) were found in Ag46 and might be related to the interstitial sulfur, which is supported by natural population analyses.
Enantioselective α‐Benzylation of Acyclic Esters Using π‐Extended Electrophiles
Authors: Schwarz Kevin J. , Yang Chao , Fyfe James W. B. , Snaddon Thomas N.
Published: July 2018

The first asymmetric cooperative Lewis base/palladium catalyzed benzylic alkylation of acyclic esters is reported. This reaction proceeds via stereodefined C1‐ammonium enolate nucleophiles. Critical to its success was the identification of benzylic phosphate electrophiles, which were uniquely reactive. Alkylated products were obtained with very high levels of enantioselectivity, and this method has been applied toward the synthesis of the thrombin inhibitor DX‐9065a.
Variable selection and parameter estimation of viral amplification in vero cell cultures dedicated to the production of a dengue vaccine
Authors: Abbate Thomas , Dewasme Laurent , Vande Wouwer Alain
Published: July 2018

In this study, a dynamic model of a Vero cell culture‐based dengue vaccine production process is developed. The approach consists in describing the process dynamics as functions of the whole living (uninfected and infected) biomass whereas previous works are based on population balance approaches. Based on the assumption that infected biomass evolves faster than other variable, the model can be simplified using a slow‐fast approximation. The structural identifiability of the model is analysed using differential algebra as implemented in the software DAISY. The model parameters are inferred from experimental datasets collected from an actual vaccine production process and the model predictive capability is confirmed both in direct and cross‐validation. The model prediction shows the impact of the metabolism on virus yield and confirms observations reported in previous studies. Multi‐modality and sensitivity analysis complement the parameter estimation, and allow to obtain confidence intervals on both parameters and state estimates. Finally, the model is used to compute the maximum infectious virus yield that can be obtained for different combinations of multiplicity of infection (MOI) and time of infection (TOI). © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2687, 2019
The GreedEx experience: Evolution of different versions for the learning of greedy algorithms
Authors: Arroyo Yoel , Molina Ana I. , Lacave Carmen , Redondo Miguel A. , Ortega Manuel
Published: July 2018

This paper presents the evolution experienced by GreedEx, an interactive application to learn greedy algorithms. It shows the four different versions currently available. A first original version for computers, two versions for iPad, and another version for smartphones. Besides, it describes the evaluation performed for each version, which has served so as to justify such evolution.
Consider court ruling's impact on higher ed's duty to prevent suicide
Authors: Rooksby Jacob H.
Published: July 2018

In a major ruling involving potential institutional liability for student suicide, the Massachusetts Supreme Judicial Court in May described the legal duty institutions owe students who express plans to act on suicidal ideation or who have attempted suicide in the recent past.
Know how to investigate reports of stalking on your campus
Authors: McCarthy Claudine
Published: July 2018

The Violence Against Women Act amendments to the Clery Act require colleges and universities to provide annual training about stalking and other forms of sexual violence, including how to properly conduct an investigation process that protects the safety of stalking victims and promotes accountability.
Rituximab maintenance improves overall survival in follicular lymphoma: A retrospective nationwide real‐world analysis from Taiwan Cancer Registry Database
Authors: Huang Huai‐Hsuan , Wen Yao‐Chun , Chen Ho‐Min , Hsiao Fei‐Yuan , Ko Bor‐Sheng
Published: July 2018

Follicular lymphoma (FL) is the most frequent indolent lymphoma in Western countries, but it is less frequent in Asia. Several trials have demonstrated the progression‐free benefit of rituximab maintenance for FL patients in Western countries. However, the overall survival (OS) benefits and effectiveness of rituximab maintenance in Asian FL patients remain uncertain. We utilized the Taiwan Cancer Registry Database and the National Health Insurance Research Database to investigate the roles of rituximab maintenance for newly diagnosed FL patients in Taiwan. Among 836 patients with newly diagnosed FL during 2009‐2012, we enrolled patients with stage II‐IV diseases receiving 4‐8 cycles of rituximab‐containing induction chemotherapies (R‐induction). We excluded those who died or received additional chemotherapy within 180 days after R‐induction. Among the 396 enrolled patients, 260 underwent rituximab maintenance (R‐maintenance group), and 136 served as the observation group. The R‐maintenance group received less anthracycline and fewer cycles of R‐induction than the observation group, but they exhibited a significantly better OS both in the univariate and multivariate analyses [hazard ratio, 0.42; 95% confidence interval, 0.19‐0.91] after adjusting for age, sex, and Ann Arbor stages. Meanwhile, we also found more patients required further therapies in the first 6 months after the cease of rituximab maintenance. In the subgroup analysis, patients older than 60 years or with stage IV diseases benefited more from rituximab maintenance. Conclusively, our nationwide study is the first one to demonstrate the OS benefit of rituximab maintenance after induction therapies in newly diagnosed FL patients from Asian populations.
Effect of marital status on survival in glioblastoma multiforme by demographics, education, economic factors, and insurance status
Authors: Xie Jun‐Chao , Yang Shuai , Liu Xue‐Yuan , Zhao Yan‐Xin
Published: July 2018

The relationship between marital status and glioblastoma multiforme (GBM) has not been addressed in depth. Here, we aimed to investigate the association between marital status and survival in GBM. We searched the Surveillance, Epidemiology, and End Results (SEER) database and extracted the data of eligible patients diagnosed with GBM after 2004. Marital status was classified as married, divorced/separated, widowed, and single. A Kaplan‐Meier test was conducted to compare the survival curves of different groups. Multivariate Cox regression was performed to evaluate overall survival (OS) and cause‐specific survival (CSS) in different groups. Subgroup analysis was applied according to demographics, typical education and income levels in the locale, and insurance status. A total of 30 767 eligible patients were included. The median OS values were 9, 7, 3, 9 months in married, divorced/separated, widowed, and single patients, respectively. After adjustment for other covariates, married patients had better OS and CSS than other patients had. In addition to marital status, demographic factors, disease progression factors, local educational level, and insurance status were also associated with survival in GBM. Furthermore, subgroup analyses revealed the protective effect of marriage in most of the comparisons. Notably, the protective effect of marriage becomes more and more apparent as time goes on. The advantageous effect of marriage on GBM survival is especially prominent in patients who are male, older than 60 years of age, White, or living in middle‐income counties. In conclusion, marital status is an independent prognostic factor for GBM.
Alkali‐Oxygen Batteries Based on Reversible Superoxide Chemistry
Authors: McCulloch William David , Xiao Neng , Gourdin Gerald , Wu Yiying
Published: July 2018

Rechargeable superoxide (O2−) batteries have the potential to surpass current lithium‐ion technology due to their high theoretical energy densities. The use of superoxides as an energy storage material is highly advantageous when compared to their close relatives, peroxides. This is due to enhanced reversibility of the 1‐electron redox process. To efficiently stabilize superoxides, larger metal cations are required such as sodium and potassium. Therefore, the two most studied systems are sodium and potassium‐oxygen batteries. Both batteries present unique advantages and challenges. In this minireview, we summarize the current research for each superoxide‐based battery and offer perspective for further research.
Iterative Assembly of Macrocyclic Lactones using Successive Ring Expansion Reactions
Authors: Stephens Thomas C. , Lawer Aggie , French Thomas , Unsworth William P.
Published: July 2018

Macrocyclic lactones can be prepared from lactams and hydroxyacid derivatives via an efficient 3‐ or 4‐atom iterative ring expansion protocol. The products can also be expanded using amino acid‐based linear fragments, meaning that macrocycles with precise sequences of hydroxy‐ and amino acids can be assembled in high yields by “growing” them from smaller rings, using a simple procedure in which high dilution is not required. The method should significantly expedite the practical synthesis of diverse nitrogen containing macrolide frameworks.
Precessional Motion in Crystalline Solid Solutions of Ionic Rotors
Authors: d'Agostino Simone , Fornasari Luca , Grepioni Fabrizia , Braga Dario , Rossi Federica , Chierotti Michele R. , Gobetto Roberto
Published: July 2018

The order–disorder phase transition associated with the uprise of reorientational motion in (DABCOH2)2+, in the supramolecular salts of general formula [1⋅(DABCOH2)]X2 (where 1=12‐crown‐4, DABCO=1,4‐diazabicyclo[2.2.2]octane, and X=Cl− or Br−), has been investigated by variable temperature X‐ray diffraction on single crystals and powder samples, as well as by DSC and solid‐state NMR spectroscopy (SSNMR). The two compounds undergo a reversible phase change at 292 and 290 K, respectively. The two crystalline materials form solid solutions [1⋅(DABCOH2)]Cl2xBr2(1−x) in the whole composition range (0 < x<1), with a decrease in the temperature of transition to a minimum of ca 280 K, corresponding to x=0.5. Activation energy values for the dynamic processes, evaluated by variable‐temperature 13C magic‐angle spinning (MAS) SSNMR and line‐shape analysis are ca. 50 kJ mol−1 in all cases. Combined diffraction and spectroscopic evidence has allowed the detection of a novel dynamic process for the (DABCOH2)2+ dications, based on a room temperature precessional motion that is frozen out below the disorder–order transition; to the best of the authors’ knowledge this phenomenon has never been observed before.
Synthesis of Structurally Diverse N‐Substituted Quaternary‐Carbon‐Containing Small Molecules from α,α‐Disubstituted Propargyl Amino Esters
Authors: Mateu Natalia , Kidd Sarah L. , Kalash Leen , Sore Hannah F. , Madin Andrew , Bender Andreas , Spring David R.
Published: July 2018

N‐containing quaternary stereocenters represent important motifs in medicinal chemistry. However, due to their inherently sterically hindered nature, they remain underrepresented in small molecule screening collections. As such, the development of synthetic routes to generate small molecules that incorporate this particular feature are highly desirable. Herein, we describe the diversity‐oriented synthesis (DOS) of a diverse collection of structurally distinct small molecules featuring this three‐dimensional (3D) motif. The subsequent derivatisation and the stereoselective synthesis exemplified the versatility of this strategy for drug discovery and library enrichment. Chemoinformatic analysis revealed the enhanced sp3 character of the target library and demonstrated that it represents an attractive collection of biologically diverse small molecules with high scaffold diversity.
Kinetic analysis of the ionization ratio effects on a three‐species plasma
Authors: Gonzalez J. , Donoso J.M.
Published: July 2018

In partially ionized plasmas, the energy transferred to electrically charged species by the electromagnetic field can be partly channelized to the population of neutrals, due to interspecies collisional processes. Depending on the relative density of neutrals, these effects may govern the collective plasma dynamics by drastically modifying particle dynamics and energy‐transport processes with respect to the fully ionized plasma‐approximation models. In this work, the influence of the ionization ratio ri on a partially ionized plasma is analysed by means of a three‐species one‐dimensional kinetic model to compute transient and steady state velocity‐dependent distribution functions. The conservative collision operators accounting for charge–charge and charge–neutral interactions allow studying several plasma scenarios with the same entire number of particles per unit of volume but for an increasing ri parameter, in the presence of a modulated signal‐like electric field. For a sequence of plasma scenarios of fixed ri, ranging from typical weakly ionized to highly ionized plasma values ri ∼ 10−7–10−4, the mass species flows are examined. These flows behave linearly with respect to ri up to a value ri ≃ 10−5 from which the quasi‐linear dependence is critically altered. The convection–diffusion equations are solved with the semianalytical Propagator Integral Method, which behaves well to deal with conservative operators, density, and field discontinuities, allowing for the use of collision terms of disparate time and spatial characteristic scales. The results can be relevant to a wide class of plasma systems and to analyse the ionization ratio effects on transport coefficients.
Dust‐ion‐acoustic solitary waves in a magnetized dusty pair‐ion plasma with Cairns‐Gurevich electrons and opposite polarity dust particles
Authors: Abdikian Alireza
Published: July 2018

The nonlinear dust‐ion‐acoustic (DIA) solitary structures have been studied in a dusty plasma, including the Cairns‐Gurevich distribution for electrons, both negative and positive ions, and immobile opposite polarity dust grains. The external magnetic field directed along the z‐axis is considered. By using the standard reductive perturbation technique and the hydrodynamics model for the ion fluid, the modified Zakharov–Kuznetsov equation was derived for small but finite amplitude waves and was provided the solitary wave solution for the parameters relevant. Using the appropriate independent variable, we could find the modified Korteweg–de Vries equation. By plotting some figures, we have discussed and emphasized how the different plasma values, such as the trapping parameter, the positive (or negative) dust number density, the non‐thermal electron parameter, and the ion cyclotron frequency, can influence the solitary wave structures. In addition, using the bifurcation theory of planar dynamical systems, we have extracted the centre and saddle points and illustrated the phase portrait of such a system for some particular plasma parameters. Finally, we have graphically investigated the behaviour of the solitary energy wave by changing the plasma values as well as by calculating the instability criterion; we have also discussed the growth rate of the solitary waves. The results could be useful for studying the physical mechanism of nonlinear propagation of DIA solitary waves in laboratory and space plasmas where non‐thermal electrons, pair‐ions, and dust particles can exist.
Help students find their strengths; don't just accommodate their needs
Authors: Sutton Halley
Published: July 2018

Sheri Yech, director of the Academic Skills Center and disability services coordinator at King's College, discussed her institution's first‐year program for students with learning differences, empowering students, and more.
An automated independent workflow for the analysis of massively parallel sequence data from forensic SNP assays
Authors: Vlachos Nicholas T , Meiklejohn Kelly A , Robertson James M
Published: July 2018

Illumina and Thermo Fisher Scientific have developed assays that permit the sequencing of forensically relevant single nucleotide polymorphisms (SNPs), along with software to determine the associated genotypes. Currently there is no method to either independently confirm the genotypes determined using the manufacturer's software, or to compare genotypes and quality metrics among samples processed using both platforms. This paper outlines an automated workflow developed in CLC Genomics Workbench that permits accurate, fast and independent analysis of SNP sequence data from either platform. To facilitate the straightforward comparison of genotypes generated from both the manufacturer's software and the independent CLC analysis, a Python script was written. Data for a total of 323 forensically relevant ancestry, identity and phenotypic SNPs can be analyzed, and the resulting genotypes, coverage, quality flags and major allele frequencies are easily compared across samples and platforms.