bluuebunny/crossref_metadata_2025 huggingface dataset:
Efecto de diferentes láminas de riego sobre la producción y calidad de fresa (Fragaria sp.)
Authors: Deaquiz Yuly Alexandra , Álvarez Herrera Javier Giovanni , Pinzón Gómez Lida Paola
Published: March 2015

La fresa es un cultivo de gran importancia económica para muchos agricultores de Colombia, principalmente para los de clima de frío de Boyacá y Cundinamarca; sin embargo, en estas zonas el bajo nivel de tecnificación del sistema de producción y el desconocimiento del manejo adecuado del riego en el cultivo de fresa conlleva al uso ineficiente del recurso hídrico. Por lo anterior, el objetivo de esta investigación fue evaluar el efecto de diferentes láminas de riego sobre la producción y calidad poscosecha de los frutos de fresa var. Ventana. Se utilizó un diseño experimental completamente al azar con cinco tratamientos y cuatro repeticiones. Los tratamientos correspondieron a cinco láminas de riego determinadas por cinco coeficientes multiplicadores de la evaporación (0,8; 1,0; 1,2; 1,4 o 1,6 de la evaporación medida dentro del invernadero). Para la siembra se utilizó turba rubia como sustrato, las aplicaciones se realizaron mediante sistema de riego por goteo. La lámina de riego de 1,6 presentó los mejores resultados de masa fresca de hojas, masa seca de hojas, corona y peciolos, área foliar y sólidos solubles totales de frutos; mientras que la lámina de riego de 1,4 obtuvo los mejores resultados de masa fresca de corona y peciolos, raíz, masa seca de raíz, frutos y relación de madurez. El coeficiente de riego de 1,4 presentó los mejores rendimientos y mantuvo una alta eficiencia en el uso del agua. El manejo de diferentes láminas de riego afecta las características organolépticas de los frutos de fresa.
Características físico-químicas de frutos de abobrinha -de-moita em função de doses de potássio em cobertura
Authors: Sampaio de Araújo Humberto , Inácio Cardoso Antonio Ismael , Evangelista Regina Maria , Suekane Takata William Hiroshi , Gasparetto Da Silva Everton
Published: March 2015

O potássio é considerado por muitos pesquisadores como o nutriente relacionado à qualidade dos frutos. No entanto, são poucas as pesquisas em que este efeito do potássio é avaliado. Objetivou-se com este trabalho avaliar o efeito de doses de potássio em cobertura na qualidade físico-química de frutos de abobrinha-de-moita (Cucurbita pepo L.) híbrido Aline. Foram avaliados cinco tratamentos (0, 50, 100, 150 e 200 kg ha-1 de K2O em cobertura), no delineamento experimental de blocos casualizados, com quatro repetições. Logo após a colheita dos frutos foram avaliadas as seguintes características físico-químicas: teor de macronutrientes nos frutos, potencial hidrogeniônico (pH), acidez total titulável (ATT), sólidos solúveis totais (SST), “ratio” (relação SST/ATT), porcentagem de açúcares redutores e a textura. O teor de potássio, o pH, e a relação SST/ATT nos frutos aumentaram à medida que se aumentou a dose de potássio, enquanto a acidez total titulável reduziu. As outras características não foram influenciadas pelas doses de potássio.
Respuestas fisiológicas y bioquímicas del fríjol caupí (Vigna unguiculata L. Walp.) bajo déficit hídrico
Authors: Cardona Ayala Carlos , Jarma Orozco Alfredo , Áramendiz Tatis Hermes , Peña Agresott Maryorik , Vergara Córdoba César
Published: March 2015

El fríjol caupí contribuye a la alimentación humana y animal en muchas regiones del mundo, especialmente en aquellos lugares donde la sequía restringe la producción agrícola. El objetivo de este trabajo fue identificar algunas respuestas fisiológicas y bioquímicas de esta especie, bajo condiciones de estrés hídrico en fase reproductiva. Se experimentó bajo un diseño completamente aleatorizado en un arreglo factorial 2x6 (2 niveles de humedad del suelo y 6 genotipos) con tres repeticiones. Se analizó la respuesta de la especie evaluando el rendimiento de la planta mediante la cuantificación del rendimiento de grano/planta, el número de vainas/planta, el número de semillas/vaina, y la longitud de la vaina; se estimó la reducción relativa del rendimiento y la susceptibilidad a la sequía. También se analizó el intercambio gaseoso, la actividad de las enzimas catalasa y ascorbato peroxidasa, así como los contenidos de clorofila, carotenoides, proteínas libres, prolina y malondialdehído. El estrés por sequía causó una disminución en el rendimiento de grano/planta del 57,72%, número de vainas/planta del 49,40% y número de semillas/vaina del 32,07%. A los 17 días de sequía, la fotosíntesis empezó a registrar valores cercanos a cero cuando el contenido de humedad del suelo se redujo alrededor del 40% de la capacidad de campo,lo cual pudo ser ocasionado por limitaciones estomáticas y, posiblemente, por limitaciones no estomáticas. La proporción de clorofila a/clorofila b (Chla/Chlb), fue significativamente más baja, mientras que el contenido de malondialdehído fue significativamente más alto, en plantas bajo estrés hídrico.
Comportamiento de precios de las variedades de papa Parda Pastusa y Diacol Capiro en Colombia (1995-2011)
Authors: Barrientos Juan Carlos , Rondón D. Camilo , Melo Sandra E.
Published: March 2015

El año 2013 los productores de papa de Colombia han protestado públicamente por la caída de los precios de este producto. Este fenómeno social no ha cambiado significativamente en los últimos años, pero cada año va agravándose afectando negativamente los ingresos de las familias productoras. Para hacer una aproximación explicativa se ha realizado una investigación documental sobre precios y un análisis estadístico de la serie de precios de las variedades Parda Pastusa y Diacol Capiro de los años 1995 a 2011. El análisis estadístico muestra resultados similares para ambas variedades. La tendencia de precios nominales es alcista y la de precios reales bajista. Las series presentan estacionalidad, siendo el primer semestre el de precios altos y el segundo el de precios medios y bajos. Este comportamiento estacional, sin embargo, tiene una ocurrencia de solo 65% para el periodo de estudio. La variabilidad es alta a muy alta reflejando la amplitud de rango entre los precios máximos y mínimos. Esto representa un enorme riesgo para los productores, sobre todo para los pequeños que no tienen ningún seguro financiero para su producción. Las series de precios presentan ciclos irregulares; sin embargo, es posible desarrollar un modelo matemático de predicción de precios como el que se presenta aquí, un modelo Sarima desarrollado con el software estadístico R. Este permite hacer pronósticos para algunos meses, cuyos resultados ayudarían a planificar mejor las siembras. Junto a esta estrategia, también se puede recurrir a una mejor planificación del mercadeo y la innovación tecnológica, caminos que pueden reducir la variabilidad de precios ocasionada principalmente por el clima, plagas, enfermedades, y otros.
Estudio de factibilidad de una planta empacadora (packing house) para cebolla de bulbo (Allium cepa L.) en el Distrito de Riego del Alto Chicamocha (Boyacá)
Authors: Martínez Q. Efraín , Rodríguez Luis Felipe , Medina C. Nancy
Published: March 2015

En Colombia la producción de cebolla de bulbo es de 320.000 t al año con lo que se abastece el consumo nacional. El departamento de Boyacá aporta el 52% y de 30.000 a 40.000 t se producen en el valle del río Chicamocha con una problemática en su producción y comercialización manifiesta en la pérdida del 28% por la ausencia de las operaciones de secado y curado. Para abordar esta problemática se utilizó un método descriptivo basado en la observación directa de las generalidades de su sistema productivo expresada por sus productores, comercializadores e industriales. El estudio de una planta empacadora para el Distrito de Riego del Alto de Chicamocha (DRACH) se justifica por que las pérdidas económicas son de 9.800 t año-1. La construcción de esta infraestructura genera un alto número de empleos directos e indirectos, institucionaliza el mercado, da valor agregado, ayuda a estabilizar precios y aumenta el tiempo de almacenamiento del producto al pasar de 8 a 72 días. Del estudio de mercados se obtiene que la demanda por el nuevo producto de cebolla curada selecta es de 15.216 t, en el mercado nacional. La planta empacadora acondicionará 32 t día-1, en un área de 1.821 m2, en dos turnos para una producción al año de 11.680 t. El proyecto presenta una TIR (tasa interna de retorno) de 29,22% y una relación B/C (beneficio costo) de 1,18 para un periodo de 5 años.
Allogeneic Transplantation of an Adipose-Derived Stem Cell Sheet Combined With Artificial Skin Accelerates Wound Healing in a Rat Wound Model of Type 2 Diabetes and Obesity
Authors: Kato Yuka , Iwata Takanori , Morikawa Shunichi , Yamato Masayuki , Okano Teruo , Uchigata Yasuko
Published: March 2015

One of the most common complications of diabetes is diabetic foot ulcer. Diabetic ulcers do not heal easily due to diabetic neuropathy and reduced blood flow, and nonhealing ulcers may progress to gangrene, which necessitates amputation of the patient’s foot. This study attempted to develop a new cell-based therapy for nonhealing diabetic ulcers using a full-thickness skin defect in a rat model of type 2 diabetes and obesity. Allogeneic adipose-derived stem cells (ASCs) were harvested from the inguinal fat of normal rats, and ASC sheets were created using cell sheet technology and transplanted into full-thickness skin defects in Zucker diabetic fatty rats. The results indicate that the transplantation of ASC sheets combined with artificial skin accelerated wound healing and vascularization, with significant differences observed 2 weeks after treatment. The ASC sheets secreted large amounts of several angiogenic growth factors in vitro, and transplanted ASCs were observed in perivascular regions and incorporated into the newly constructed vessel structures in vivo. These results suggest that ASC sheets accelerate wound healing both directly and indirectly in this diabetic wound-healing model. In conclusion, allogeneic ASC sheets exhibit potential as a new therapeutic strategy for the treatment of diabetic ulcers.
Antioxidants Complement the Requirement for Protein Chaperone Function to Maintain β-Cell Function and Glucose Homeostasis
Authors: Han Jaeseok , Song Benbo , Kim Jiun , Kodali Vamsi K. , Pottekat Anita , Wang Miao , Hassler Justin , Wang Shiyu , Pennathur Subramaniam , Back Sung Hoon , Katze Michael G. , Kaufman Randal J.
Published: March 2015

Proinsulin misfolding in the endoplasmic reticulum (ER) initiates a cell death response, although the mechanism(s) remains unknown. To provide insight into how protein misfolding may cause β-cell failure, we analyzed mice with the deletion of P58IPK/DnajC3, an ER luminal co-chaperone. P58IPK−/− mice become diabetic as a result of decreased β-cell function and mass accompanied by induction of oxidative stress and cell death. Treatment with a chemical chaperone, as well as deletion of Chop, improved β-cell function and ameliorated the diabetic phenotype in P58IPK−/− mice, suggesting P58IPK deletion causes β-cell death through ER stress. Significantly, a diet of chow supplemented with antioxidant dramatically and rapidly restored β-cell function in P58IPK−/− mice and corrected abnormal localization of MafA, a critical transcription factor for β-cell function. Antioxidant feeding also preserved β-cell function in Akita mice that express mutant misfolded proinsulin. Therefore defective protein folding in the β-cell causes oxidative stress as an essential proximal signal required for apoptosis in response to ER stress. Remarkably, these findings demonstrate that antioxidant feeding restores cell function upon deletion of an ER molecular chaperone. Therefore antioxidant or chemical chaperone treatment may be a promising therapeutic approach for type 2 diabetes.
Increasing Pyruvate Dehydrogenase Flux as a Treatment for Diabetic Cardiomyopathy: A Combined 13C Hyperpolarized Magnetic Resonance and Echocardiography Study
Authors: Le Page Lydia M. , Rider Oliver J. , Lewis Andrew J. , Ball Vicky , Clarke Kieran , Johansson Edvin , Carr Carolyn A. , Heather Lisa C. , Tyler Damian J.
Published: March 2015

Although diabetic cardiomyopathy is widely recognized, there are no specific treatments available. Altered myocardial substrate selection has emerged as a candidate mechanism behind the development of cardiac dysfunction in diabetes. As pyruvate dehydrogenase (PDH) activity appears central to the balance of substrate use, we aimed to investigate the relationship between PDH flux and myocardial function in a rodent model of type 2 diabetes and to explore whether or not increasing PDH flux, with dichloroacetate, would restore the balance of substrate use and improve cardiac function. All animals underwent in vivo hyperpolarized [1-13C]pyruvate magnetic resonance spectroscopy and echocardiography to assess cardiac PDH flux and function, respectively. Diabetic animals showed significantly higher blood glucose levels (10.8 ± 0.7 vs. 8.4 ± 0.5 mmol/L), lower PDH flux (0.005 ± 0.001 vs. 0.017 ± 0.002 s-1), and significantly impaired diastolic function (transmitral early diastolic peak velocity/early diastolic myocardial velocity ratio [E/E′] 12.2 ± 0.8 vs. 20 ± 2), which are in keeping with early diabetic cardiomyopathy. Twenty-eight days of treatment with dichloroacetate restored PDH flux to normal levels (0.018 ± 0.002 s-1), reversed diastolic dysfunction (E/E′ 14 ± 1), and normalized blood glucose levels (7.5 ± 0.7 mmol/L). The treatment of diabetes with dichloroacetate therefore restored the balance of myocardial substrate selection, reversed diastolic dysfunction, and normalized blood glucose levels. This suggests that PDH modulation could be a novel therapy for the treatment and/or prevention of diabetic cardiomyopathy.
Dimethylglycine Deficiency and the Development of Diabetes
Authors: Magnusson Martin , Wang Thomas J. , Clish Clary , Engström Gunnar , Nilsson Peter , Gerszten Robert E. , Melander Olle
Published: March 2015

Experimental studies have suggested possible protective effects of dimethylglycine (DMG) on glucose metabolism. DMG is degraded to glycine through a DMG-dehydrogenase (DMGDH)-catalyzed reaction, and this is the only known pathway for the breakdown of DMG in mammals. In this study, we aimed to identify the strongest genetic determinant of circulating DMG concentration and to investigate its associations with metabolic traits and incident diabetes. In the cohort with full metabolomics data (n = 709), low plasma levels of DMG were significantly associated with higher blood glucose levels (P = 3.9E–4). In the genome-wide association study (GWAS) of the discovery cohort (n = 5,205), the strongest genetic signal of plasma DMG was conferred by rs2431332 at the DMGDH locus, where the major allele was associated with lower DMG levels (P = 2.5E–15). The same genetic variant (major allele of rs2431332) was also significantly associated with higher plasma insulin (P = 0.019), increased HOMA insulin resistance (P = 0.019), and an increased risk of incident diabetes (P = 0.001) in the pooled analysis of the discovery cohort together with the two replication cohorts (n = 20,698 and n = 7,995). These data are consistent with a possible causal role of DMG deficiency in diabetes development and encourage future studies examining if inhibition of DMGDH, or alternatively, supplementation of DMG, might prove useful for the treatment/prevention of diabetes.
Changes in Gene Expression in Responders and Nonresponders to a Low-Intensity Walking Intervention
Authors: Osler Megan E. , Fritz Tomas , Caidahl Kenneth , Krook Anna , Zierath Juleen R. , Wallberg-Henriksson Harriet
Published: March 2015

OBJECTIVE

Daily physical activity remains an effective strategy to prevent obesity and type 2 diabetes. However, the metabolic response to exercise training is variable, and the precise clinical and molecular determinants that mark the metabolic improvements remain unknown. We tested the hypothesis that clinical improvements in glucose control after low-intensity exercise in individuals with impaired glucose tolerance (IGT) are coupled to alterations in skeletal muscle gene expression.

RESEARCH DESIGN AND METHODS

We investigated 14 overweight individuals with IGT before and after a 4-month low-intensity unsupervised walking exercise intervention. Clinical and anthropometric measurements and glucose tolerance were determined before and after the intervention. Skeletal muscle biopsy specimens were obtained for mRNA expression analysis.

RESULTS

Waist circumference and work capacity during cycle ergometry were improved in individuals who achieved normal glucose tolerance (NGT) after exercise training (IGT-NGT; n = 9) but in not individuals who remained IGT (IGT-IGT; n = 5). Pretraining glycemic control was better in IGT-NGT compared with IGT-IGT. mRNA expression of mitochondrial markers and transcription factors was increased in IGT-NGT after exercise intervention and normalized to levels measured in a separate cohort of nonexercised individuals with NGT. Conversely, these markers were unaltered after exercise intervention in IGT-IGT.

CONCLUSIONS

Normalization of metabolic control can be achieved after low-intensity exercise in individuals with IGT. This can be tracked with increased mRNA expression of mitochondrial and metabolic genes in skeletal muscle. However, for individuals presenting with a greater derangement in glycemia, the potential for clinical and metabolic improvements after this low-intensity unsupervised exercise protocol appears to be limited.
UV distributed Bragg reflectors build from porous silicon multilayers
Authors: Morales F. , García G. , Luna A. , López R. , Rosendo E. , Díaz T. , Juárez H.
Published: March 2015

UV Distributed Bragg reflectors were fabricated by a two-step thermal oxidation process over porous silicon multilayers (PS-ML), which were prepared by room-temperature electrochemical anodization of silicon wafers. The optical behavior of the PS-ML before and after oxidation was studied by reflectance measurements. It was observed an UV shift from 430 to 300 nm in the peak of the reflectance spectrum after oxidation of the PS-ML. This was attributed to the presence of silicon oxide over the surface of the silicon filaments. Such oxide also reduced the refractive index of each porous silicon monolayer. The bandgap of the PS-ML was calculated by the Kubelka-Munk approximation, which showed an increase in the bandgap from 3.11 to 4.36 eV after the thermal oxidation process. It was suggested that the observed optical response could opens the possibility of fabrication of UV optoelectronic devices based entirely in the silicon technology.
Postponement and Prophecy: Northrop Frye and “The Great Code” of Yeats's “Byzantium”
Authors: Pearson Nels
Published: March 2015

The essay examines W.B. Yeats's “Byzantium” in light of Northrop Frye's ideas about the resonances of Biblical language, especially its typology and deferred revelation, in Western poetry. It argues that Yeats's effort to communicate the eternal within time by combining proclamation and enigma, revelation and ambiguity, bears deep similarities to the process of signalling and postponing revelation that drives Biblical language. By examining the role of postponed and unverifiable final meaning in “Byzantium” via Frye, the essay also points out important intimacies and differences between post-structural theories of semiotic contingency and formalist, anthropological ideas about the distinct nature of poetic, metaphorical language.
“I look into their myriad eyes”: The Queer Gaze of Tennessee Williams'sMemoirs
Authors: Fong Tony
Published: March 2015

This article scrutinizes the various bodies of Tennessee Williams's Memoirs (1975) by examining the corporeality of the text itself. When faced with his own queerness, the dramatist consistently spasms and vomits. This nausea, I argue, is connected with the “horrors” of femininity that Williams exiles for the sake of a masculine identity; he gags and heaves as an involuntary form of self-reproach. Such moments of abject repudiation—often accompanied by temporal shifts and narrative incoherencies—give shape to the autobiography. Williams's body thus betrays his queerness. Memories of Kip (Kiernan) and Frank Merlo—the dramatist's first and “most long-lasting” lovers, respectively—ultimately frustrate Williams's desire to differentiate from his “swishy” supporting characters. The autobiography—in spite of its author's anxieties—tasks the reader to acknowledge the presence of the two lovers' lives in Williams's personal history.
Bordering on African American: Wayde Compton and the Readability of Blackness
Authors: Bickersteth Bertrand
Published: March 2015

This essay attempts to establish a critical context for the African Canadian literary imagination that situates itself in Western Canada and, specifically, British Columbia. Wayde Compton's poetry offers several sites for questioning black identity in Canada by visiting the trope of borders. Blackness in Canada is more readily viewed apart from rather a part of the central histories of the nation. In Western Canada, this tendency is even more apparent since regional black histories do not conform as easily to the master narratives of underground-railroad rescues and benevolent abolitionism that are more readily accessed in the central and eastern provinces. In response, Compton's poetry attempts to negotiate a regional black diasporic aesthetic by challenging the fixity of race and place. This essay shows that in engaging the ephemerality of black communities in British Columbia, Compton's poetry underscores filiation through chance relationships and demonstrates black belonging through discursive readability.
The Use of Information and Communication Technologies in Organizational Learning Practices: A Research Study in an Innovation-oriented Portuguese Organization
Authors: Petiz Sara , Ramos Fernando , Roseiro Pedro
Published: March 2015

This study aims at understanding the use of ICT core Learning and Innovation (L&I) practices and their impact in the firm capability. The analysis of organizational learning capability proposals and the Portuguese innovation management standard NP4457 recommendations, allowed the identification of five common practices that were used in the study: idea generation; market and technology surveillance; problem solving; dialogue and knowledge transfer; training and competence development. A mixed method case study has been developed with a Portuguese large company, where each L&I practice was assessed in a perspective of the means promoted by the organization - processes and ICT resources; and results - in terms of the institutional leader and workers’ perceptions regarding the impact of those practices. The leader perception was collected through interview process and worker’s perception through an online questionnaire. The paper provides some findings showing that ICT is proving to promote an effective basis for organizational L&I practices and it is perceived by both leader and workers has contributing positively to the firm capability.
Tap it again, Sam: Harmonizing Personal Environments towards Lifelong Learning
Authors: Tabuenca Bernardo , Kalz Marco , Specht Marcus
Published: March 2015

The increasing number of mobile vendors releasing NFC-enabled devices to the market and their prominent adoption has moved this technology from a niche product to a product with a large market-share. NFC facilitates natural interactions between digital world and physical learning environments. The scaffolding of learning ecologies is a key aspect for lifelong learners in their challenge to integrate learning activities into busy daily life. The contribution of this manuscript is twofold: first, a review of scientific literature in which NFC has been used with a direct or indirect purpose to learn is presented, and potential uses for learners are classified according to their type of interaction; based on these findings the NFC MediaPlayer is presented as an instantiation of an ecology of resources (EoR) in a lifelong learning context. Finally, shortcomings and best practices are highlighted in the conclusions, and future work is discussed.
Cloud-Based Content Synchronization Method for Collaborative Learning Environment
Authors: Lim Geunsik , Lee Donghwa , Suh Sang-bum
Published: March 2015

Existing online education has moved from desktop environments to mobile environments due to the proliferation of smart devices. Online educational systems running on smart devices have the advantage of allowing users to learn online regardless of the location of the users. In particular, data synchronization enables users to cooperate on contents in real time anywhere by sharing their files via cloud storage. However, users cannot collaborate by simultaneously modifying files that are shared with one another. In this paper, we propose a content collaboration method and a history management technique that are based on distributed system structure and can synchronize data shared in the cloud for multiple users and multiple devices. Our proposed system helps users performing work on the collaborative content by automatically merging updated contents of cloud files among users.
Realization of a Platform-Independent Web-Application for Engineering Education
Authors: Siemund Henning , Kracht Michael , Goebel Holger
Published: March 2015

In this paper an approach to realizing a web-based and interactive learning environment for engineering education is presented which is runnable on conventional desktop computers as well as on modern mobile devices such as tablets or smartphones. The presented course program is intended to supplement traditional lectures and text books at the Helmut Schmidt University, Hamburg.
A Case Study in Corporate E-Learning
Authors: Wong Amy , Sixl-Daniell Karin
Published: March 2015

This case study introduces a corporate e-learning initiative in an India-based multinational company in the IT sector. The company provides consulting, enterprise, and telecom solutions across various industries such as banking and finance, energy and utilities, healthcare and life sciences, manufacturing, public sector and government, retail, media and entertainment, travel, transportation and logistics, and telecommunications and information technology. It employs more than 95,000 employees across 51 countries and has an established talent management and development program in place. In the recent years, the company has effectively incorporated e-learning in the training and development of a selected pool of talent that is being groomed to take up various leadership positions within the corporation.
Detecting hazardous situations faced by presbycusic pedestrians in cities: an audio-texture approach
Authors: Hussein Faten , Ghozi Raja , Jaïdane Mériem , Péneau Jean-Pierre
Published: March 2015

Within a universal context of an aging population along with an increasing consciousness regarding senior pedestrians’ safe access to the city, we examine the case of seniors affected by presbycusis, specifically their altered perceptions of the urban sonic ambiances during their daily journeys through the city. In this study, we present the urban configurations in which alarming situations were encountered by senior pedestrians suffering from presbycusis. We then construct an experimental protocol correlating collected data including audio signals, commented walks and physiological measurements of stress level generated while crossing the urban configurations previously identified. This cross-analysis process may provide urban planners with two-dimensional graphic representations intended to detect hazardous situations in order to anticipate them and minimize their effects.
Réécritures posthumes de Tchicaya U Tam’si entre Brazzaville et Pointe-Noire
Authors: Leroux Pierre
Published: March 2015

L'œuvre théâtrale de l'auteur congolais Tchicaya U Tam'si (1931-1988) se résume à trois textes : Le Zulu, Le Destin glorieux du Maréchal Nnikon-Nniku prince qu'on sort et Le Bal de Ndinga. Cependant, les nombreuses adaptations pour la scène de romans, nouvelles et autres ensembles de poésies témoignent de la volonté qu'ont eue certains artistes congolais ou français de se réapproprier l'héritage du « père de notre rêve ». Au travers de l'examen de trois spectacles montés à Brazzaville et à Pointe-Noire, cet article tente de montrer comment la scène transforme les textes et comment l'auteur lui-même devient un personnage représenté et fantasmé.
Le Kongo de Sony Labou Tansi
Authors: Gahungu Céline
Published: March 2015

Les textes inédits de Sony Labou Tansi proposent une réflexion sur l’histoire, et plus singulièrement sur celle du Kongo. Le souvenir du prestigieux royaume apparaît dès les premiers manuscrits, composés au début des années 1970. Loin d’être circonscrit aux écrits de jeunesse, le Kongo surgit sous de multiples formes dans le dédale des textes rédigés au cours des années suivantes. Cette fascination pousse l’écrivain dans une dynamique de recherche esthétique : comment évoquer cet illo tempore mythique sans sacrifier à une historicité convenue ? Comment inventer une écriture en mesure de rendre compte du fabuleux royaume ?L’analyse littéraire ne peut cependant faire fi du contexte politique dans lequel Sony Labou Tansi s’inscrit. Outre sa dimension historique et toponymique, Kongo est un ethnonyme dont l’auteur s’est réclamé. Celui-ci a revendiqué à de nombreuses reprises son appartenance à une identité kongo au point de s’être engagé, à la fin des années 1980, dans les rangs du MCDDI1. Ce discours identitaire et l’adhésion à un parti ethnique ont troublé l’image d’un auteur volontiers perçu comme un démocrate véritable. Est-il possible d’articuler le Kongo littéraire et le Kongo politique ? Le Kongo, dont l’ombre portée apparaît dans les manuscrits littéraires mais également dans les articles et les déclarations politiques, pourrait-il nous aider à saisir les enjeux de l’écriture protéiforme de Sony Labou Tansi ?
La bande dessinée Congo 50 ou la mémoire collective d’une indépendance difficile
Authors: Federici Sandra
Published: March 2015

Dans la bande dessinée Congo 50, Roularta Books et Africalia, 2010, publiée à l’occasion du cinquantenaire de l’indépendance du Congo, huit auteurs de l’association BD Kin Label racontent l’histoire des cinquante ans d’indépendance de leur pays, sous la coordination du scénariste français Alain Brezault et la direction artistique du dessinateur congolais Asimba Bathy. Recueilli dans des archives numériques, le processus de genèse des idées et de la fabrication de l’album se fonde sur la recherche d’un équilibre entre le rôle et le poids respectifs des différents agents qui ont contribué au projet. Cette œuvre collective peut être considérée comme paradigmatique d’un type de production artistique assez pratiquée en Afrique, qui consiste en la création de produits culturels « du Sud » sous l’impulsion d’une commande institutionnelle « du Nord ».
Silencing IFN-γ Binding/Signaling in Astrocytes versus Microglia Leads to Opposite Effects on Central Nervous System Autoimmunity
Authors: Ding Xiaoli , Yan Yaping , Li Xing , Li Ke , Ciric Bogoljub , Yang Jingxian , Zhang Yuan , Wu Shuai , Xu Hui , Chen Wanjun , Lovett-Racke Amy E. , Zhang Guang-Xian , Rostami Abdolmohamad
Published: March 2015

IFN-γ, the hallmark cytokine of Th1 cells, plays an important role in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Thus far, the role of IFN-γ in EAE has been largely studied through its effects on immune cells, whereas much less is known about its effects on CNS cells, especially in vivo. In this study, we dissected the in vivo effects and mechanisms of IFN-γ binding/signaling in astrocytes and microglia, and found that IFN-γ signaling in these cell types has opposite effects in EAE pathogenesis. Silencing IFN-γ binding/signaling in astrocytes alleviated EAE, whereas in microglia, and likely in some infiltrating macrophages, it increased disease severity. Silencing IFN-γ signaling in astrocytes resulted in diminished expression of chemokines and fewer inflammatory cells infiltrating into the CNS, whereas blocking IFN-γ binding/signaling in microglia, probably infiltrating macrophages as well, increased disease severity through augmented activation and proliferation of microglia. Further, blocking IFN-γ binding/signaling in astrocytes alleviated both Th1- and Th17-mediated adoptive EAE, indicating an important role for IFN-γ signaling in astrocytes in autoimmune CNS inflammation. Thus, our study defines novel mechanisms of action of IFN-γ in EAE pathogenesis, and also highlights an opportunity for development of multiple sclerosis therapies directed at CNS cells.
Cyclin-Dependent Kinases Regulate Ig Class Switching by Controlling Access of AID to the Switch Region
Authors: He Minghui , Cortizas Elena M. , Verdun Ramiro E. , Severinson Eva
Published: March 2015

Ig class switching requires cell proliferation and is division linked, but the detailed mechanism is unknown. By analyzing the first switching cells early in the kinetics, our analysis suggested that proliferating B cells had a very short G1 phase (<3.5 h), a total cell cycle time of ∼11 h, and that Ig class switching preferentially occurred in the late G1 or early S phase. Inhibition of cyclin-dependent kinases (CDKs) caused dramatic reduction of switching rate within 6 h. This was associated with less targeting of activation-induced cytidine deaminase (AID) to the Igh locus. Interestingly, ectopically expressed nuclear AID in HeLa cells was preferentially found in the early S phase. Furthermore, in CDK2 hypomorphic cells there was reduced nuclear AID accumulation. Thus, our data are compatible with the idea that division-linked Ig class switching is in part due to CDK2-regulated AID nuclear access at the G1/S border.
Caspase-1–Independent IL-1 Release Mediates Blister Formation in Autoantibody-Induced Tissue Injury through Modulation of Endothelial Adhesion Molecules
Authors: Sadeghi Hengameh , Lockmann Anike , Hund Anna-Carina , Samavedam Unni K. S. R. L. , Pipi Elena , Vafia Katerina , Hauenschild Eva , Kalies Kathrin , Pas Hendri H. , Jonkman Marcel F. , Iwata Hiroaki , Recke Andreas , Schön Michael P. , Zillikens Detlef , Schmidt Enno , Ludwig Ralf J.
Published: March 2015

Although reports documented aberrant cytokine expression in autoimmune bullous dermatoses (AIBDs), cytokine-targeting therapies have not been established in these disorders. We showed previously that IL-6 treatment protected against tissue destruction in experimental epidermolysis bullosa acquisita (EBA), an AIBD caused by autoantibodies to type VII collagen (COL7). The anti-inflammatory effects of IL-6 were mediated by induction of IL-1ra, and prophylactic IL-1ra administration prevented blistering. In this article, we demonstrate elevated serum concentrations of IL-1β in both mice with experimental EBA induced by injection of anti-COL7 IgG and in EBA patients. Increased IL-1α and IL-1β expression also was observed in the skin of anti-COL7 IgG-injected wild-type mice compared with the significantly less diseased IL-1R–deficient or wild-type mice treated with the IL-1R antagonist anakinra or anti–IL-1β. These findings suggested that IL-1 contributed to recruitment of inflammatory cells into the skin. Accordingly, the expression of ICAM-1 was decreased in IL-1R–deficient and anakinra-treated mice injected with anti-COL7. This effect appeared to be specifically attributable to IL-1 because anakinra blocked the upregulation of different endothelial adhesion molecules on IL-1–stimulated, but not on TNF-α–stimulated, cultured endothelial cells. Interestingly, injection of caspase-1/11–deficient mice with anti-COL7 IgG led to the same extent of skin lesions as in wild-type mice. Collectively, our data suggest that IL-1, independently of caspase-1, contributes to the pathogenesis of EBA. Because anti–IL-1β in a prophylactic setting and anakinra in a quasi-therapeutic setting (i.e., when skin lesions had already developed) improved experimental EBA, IL-1 appears to be a potential therapeutic target for EBA and related AIBDs.
Trastuzumab Triggers Phagocytic Killing of High HER2 Cancer Cells In Vitro and In Vivo by Interaction with Fcγ Receptors on Macrophages
Authors: Shi Yun , Fan Xuejun , Deng Hui , Brezski Randall J. , Rycyzyn Michael , Jordan Robert E. , Strohl William R. , Zou Quanming , Zhang Ningyan , An Zhiqiang
Published: March 2015

Trastuzumab has been used for the treatment of HER2-overexpressing breast cancer for more than a decade, but the mechanisms of action for the therapy are still being actively investigated. Ab-dependent cell-mediated cytotoxicity mediated by NK cells is well recognized as one of the key mechanisms of action for trastuzumab, but trastuzumab-mediated Ab-dependent cellular phagocytosis (ADCP) has not been established. In this study, we demonstrate that macrophages, by way of phagocytic engulfment, can mediate ADCP and cancer cell killing in the presence of trastuzumab. Increased infiltration of macrophages in the tumor tissue was associated with enhanced efficacy of trastuzumab whereas depletion of macrophages resulted in reduced antitumor efficacy in mouse xenograft tumor models. Among the four mouse FcγRs, FcγRIV exhibits the strongest binding affinity to trastuzumab. Knockdown of FcγRIV in mouse macrophages reduced cancer cell killing and ADCP activity triggered by trastuzumab. Consistently, an upregulation of FcγRIV expression by IFN-γ triggered an increased ADCP activity by trastuzumab. In an analogous fashion, IFN-γ priming of human macrophages increased the expression of FcγRIII, the ortholog of murine FcγRIV, and increased trastuzumab-mediated cancer cell killing. Thus, in two independent systems, the results indicated that activation of macrophages in combination with trastuzumab can serve as a therapeutic strategy for treating high HER2 breast cancer by boosting ADCP killing of cancer cells.
Induction of an Altered CD40 Signaling Complex by an Antagonistic Human Monoclonal Antibody to CD40
Authors: Bankert Katherine C. , Oxley Kyp L. , Smith Sonja M. , Graham John P. , de Boer Mark , Thewissen Marielle , Simons Peter J. , Bishop Gail A.
Published: March 2015

Blocking the interaction of CD40 with its ligand CD154 is a desirable goal of therapies for preventing and/or ameliorating autoimmune diseases and transplant rejection. CD154-blocking mAbs used in human clinical trials resulted in unanticipated vascular complications, leading to heightened interest in the therapeutic potential of antagonist mAbs specific for human CD40. Abs that do not require physical competition with CD154 to inhibit CD40 signaling have particular therapeutic promise. In this study, we demonstrate that the antagonist anti-human CD40 mAb PG102 fails to trigger CD40-mediated activation, as well as impairs CD154-mediated CD40 activation, via a distinct nonstimulatory CD40 signaling mechanism. PG102 did not induce early CD40-induced signaling events, and it inhibited early kinase and transcription factor activation by CD154 or agonist anti-CD40 mAbs. However, PG102 stimulated normal CD40-mediated TNFR-associated factor (TRAF)2 and TRAF3 degradation. PG102 induced the formation of a CD40 signaling complex that contained decreased amounts of both TRAF2 and TRAF3 and TRAF2-associated signaling proteins. Additionally, PG102-induced CD40 signaling complexes failed to recruit TRAF6 to detergent-insoluble membrane fractions. Fab fragments of PG102, while retaining CD40 binding, did not induce TRAF degradation, nor could they inhibit CD154-stimulated B cell signaling, indicating that CD40 aggregation is required for the signaling inhibition induced by PG102. The antagonistic impact of PG102 on CD40 signaling reveals that the manner of CD40 ligation can determine sharply different outcomes for CD40 signaling and suggests that such information can be used to therapeutically manipulate these outcomes.
The Role of PTPN22 Risk Variant in the Development of Autoimmunity: Finding Common Ground between Mouse and Human
Authors: Rawlings David J. , Dai Xuezhi , Buckner Jane H.
Published: March 2015

The PTPN22 1858T variant was among the first single nucleotide polymorphisms to be associated with multiple autoimmune diseases. Lymphocyte tyrosine phosphatase, a coding variant within the tyrosine phosphatases, is known to participate in AgR signaling; the impact of this variant on the immune response and its role in the development of autoimmunity have been a focus of study. These studies used a series of approaches, including transfected cell lines, animal models, and primary human lymphocytes, and identified multiple alterations in cell signaling and function linked to the PTPN22 variant. Conflicting findings led to questions of how best to study the role of this variant in human autoimmunity. In this review, we discuss these differences and the factors that may account for them, as well as show how an integrated approach can lead to a more complete understanding of the mechanisms that promote autoimmunity in the context of the PTPN22 1858T risk variant.
Tumor-Infiltrating Dendritic Cells in Cancer Pathogenesis
Authors: Tran Janco Jo Marie , Lamichhane Purushottam , Karyampudi Lavakumar , Knutson Keith L.
Published: March 2015

Dendritic cells (DCs) play a pivotal role in the tumor microenvironment, which is known to affect disease progression in many human malignancies. Infiltration by mature, active DCs into the tumors confers an increase in immune activation and recruitment of disease-fighting immune effector cells and pathways. DCs are the preferential target of infiltrating T cells. However, tumor cells have means of suppressing DC function or of altering the tumor microenvironment in such a way that immune-suppressive DCs are recruited. Advances in understanding these changes have led to promising developments in cancer-therapeutic strategies targeting tumor-infiltrating DCs to subdue their immunosuppressive functions and enhance their immune-stimulatory capacity.
IFN-α/β Receptor Signaling Promotes Regulatory T Cell Development and Function under Stress Conditions
Authors: Metidji Amina , Rieder Sadiye Amcaoglu , Glass Deborah Dacek , Cremer Isabelle , Punkosdy George A. , Shevach Ethan M.
Published: March 2015

Type I IFNs are a family of cytokines with antiviral and immunomodulatory properties. Although the antiviral effects of IFNs are well characterized, their immunomodulatory properties are less clear. To specifically address the effects of type I IFNs on T regulatory cells (Tregs), we studied mixed bone marrow chimeras between wild-type and IFN-α/β receptor (IFNAR) knockout (KO) mice, and heterozygous female mice expressing a Treg-specific deletion of the IFNAR. In these two models, IFNAR signaling promotes the development of the Treg lineage in the thymus and their survival in the periphery. IFNAR KO Tregs had a higher expression of the proapoptotic gene Bim and higher frequency of active caspase-positive cells. IFNAR KO Tregs from chimeric mice displayed a more naive phenotype, accompanied by lower levels of CD25 and phosphorylated STAT5. Therefore, in Tregs, IFNAR signaling may directly or indirectly affect phosphorylation of STAT5. In mixed chimeras with Scurfy fetal liver, Tregs derived from IFNAR KO bone marrow were unable to control T effector cell activation and tissue inflammation. Under stress conditions or in a competitive environment, IFNAR signaling may be required to maintain Treg homeostasis and function.
Association between Key Management Personnel Remuneration and the Performance of Authorized Deposit-Taking Institutions in Australia
Authors: Li Xue , Munir Rahat , Kilgore Alan
Published: March 2015

The study investigates the association between each component of key management personnel remuneration (short-term and long-term remuneration) and total remuneration, and the performance of Authorized Deposit-taking Institutions (ADIs) in Australia. Data were collected from 91ADIs regulated by the Australian Prudential Regulation Authority. The study provides evidence that total key management personnel remuneration, short-term key management personnel remuneration and long-term key management personnel remuneration are significantly associated with the performance of ADIs, while the pay-performance association is weaker for long-term remuneration as compared to total remuneration and short-term remuneration. In addition, size of the board, existence of remuneration board committee and composition of remuneration board committee is significantly associated and composition of the board is partially associated with the performance of ADIs in Australia. The findings of the study also suggest that the pay-performance association is more sensitive for short-term remuneration as compared to long-term remuneration, indicating that although long-term remuneration is widely used by ADIs, short-term remuneration is an important part of key management personnel remuneration.
Providing a New Model for Assessment of Working Capital Management:Evidence from Tehran Stock Exchange
Authors: Fahim Seyed Reza Seyednezhad , Kaviani Meysam , Fashtali Mohamad Pashaei
Published: March 2015

Working Capital Management (WCM) is one of the key facets of financial management and organization management, for the direct effect it has on company liquidity and profitability. There is a probability of bankruptcy for companies with poor working capital management despite generation of positive return. Current paper explains the relationship of WCM with profitability-based indicators at the hand of a new model. For this purpose, 90 listed companies on Tehran Stock Exchange whose financial data for the period 2008 through to 2012 was available were selected. The results do not confirm significant inverse U-shape relationship of Cash Conversion Cycle (CCC) and Net Working Capital to Total Assets (NWC/TA) as indicators (predictors) of working capital with Return on Assets (ROA), but do indicate a significant inverse U-shape relationship of current ratio and quick ratio with ROA. From the findings, one might infer that each industry has its own optimum current and quick ratios maximizing its return.
Impact of High Light on Reactive Oxygen Species Production within Photosynthetic Biological Membranes
Authors: D. V. Vetoshkina , M. M. Borisova-Mubarakshina , I. A. Naydov , M. A. Kozuleva , B. N. Ivanov
Published: March 2015

In this study we describe the mechanisms of reactive oxygen species (ROS) production in the photosynthetic electron transport chain of higher plants chloroplasts under illumination. We implement an improved method for the measurement of hydrogen peroxide (H2O2) production in lipid phase of photosynthetic membranes of chloroplasts. Total rate of H2O2 production and the production within the thylakoid membrane under operation of photosynthetic electron transport chain is evaluated. Obtained data show that even in the presence of an efficient electron acceptor, methyl viologen, an increase in light intensity leads to an increase in H2O2 production mainly within the thylakoid membranes. The role of H2O2 produced within the photosynthetic biological membrane is discussed.
Wicked Interactions
Authors: Wiltse Heather , Stolterman Erik , Redström Johan ,   Philosophy Documentation Center
Published: March 2015

The digital computational technologies that over the past decades have come to be fully integrated into nearly all aspects of human life have varying forms, scales, interactive mechanisms, functions, configurations, and interconnections. Much of this complexity and associated implications for human experience are, however, hidden by prevalent notions of ‘the computer’ as an object. In this paper, we consider how everyday digital technologies collectively mediate human experience, arguing that these technologies are better understood as fluid assemblages that have as many similarities with the infra-structural as they have properties typical for objects. We characterize these aspects in terms of ‘wicked interactions,’ drawing on and adapting the classic theory of wicked problems in design discourse that has similarly considered the complexity of interactions with and within other types of social infrastructure. In doing this we emphasize the need and the potential for building up connections between philosophy of technology and design discourse, with the hope that this might further the shared goals of understanding digital technologies and their consequences and determining how to act in relation to them and their design.