bluuebunny/crossref_metadata_2025 huggingface dataset:
Rice SPX6 negatively regulates the phosphate starvation response through suppression of the transcription factor PHR2
Authors: Zhong Yongjia , Wang Yuguang , Guo Jiangfan , Zhu Xinlu , Shi Jing , He Qiuju , Liu Yu , Wu Yunrong , Zhang Li , Lv Qundan , Mao Chuanzao
Published: April 2018

Phosphorus (P) is an essential macronutrient for plant growth and development, but the molecular mechanism determining how plants sense external inorganic phosphate (Pi) levels and reprogram transcriptional and adaptive responses is incompletely understood.

In this study, we investigated the function of OsSPX6 (hereafter SPX6), an uncharacterized member of SPX domain (SYG1, Pho81 and XPR1)‐containing proteins in rice, using reverse genetics and biochemical approaches.

Transgenic plants overexpressing SPX6 exhibited decreased Pi concentrations and suppression of phosphate starvation‐induced (PSI) genes. By contrast, transgenic lines with decreased SPX6 transcript levels or spx6 mutant showed significant Pi accumulation in the leaf and upregulation of PSI genes. Overexpression of SPX6 genetically suppressed the overexpression of PHOSPHATE STARVATION RESPONSE REGULATOR 2 (PHR2) in terms of the accumulation of high Pi content. Moreover, direct interaction of SPX6 with PHR2 impeded PHR2 translocation into the nucleus, and inhibited PHR2 binding to the P1BS (PHR1 binding sequence) element. SPX6 protein was degraded in leaves under Pi‐deficient conditions, whereas it accumulated in roots.

We conclude that rice SPX6 is another important negative regulator in Pi starvation signaling through the interaction with PHR2. SPX6 shows different responses to Pi starvation in shoot and root, which differ from those of other SPX proteins.
Unravelling the mode of action of plant proteases
Authors: van der Hoorn Renier A. L. , Rivas Susana
Published: April 2018

This article is a Commentary on Schaller et al. (pp. 901–915), Liu & Moschou (pp. 916–922), James et al. (pp. 923–928), Dissmeyer et al. (pp. 929–935), Demir et al. (pp. 936–943), Zhang et al. (pp. 1106–1126), Radchuk et al. (pp. 1127–1142), Cai et al. (pp. 1143–1155), Lema Asqui et al. (pp. 1156–1166), Beloshistov et al. (pp. 1167–1178) and Klemenčič & Funk (pp. 1179–1191), all of which are published in this issue.
Cognitive Dissonance and Changes in External Political Efficacy: A Panel Study of Chinese Students Studying in Taiwan
Authors: Wang Chia‐Chou
Published: April 2018

Does studying in a democratic country elicit cognitive dissonance in students from communist countries and lead to changes in their political attitudes? This study recruited subjects from among Chinese students studying in Taiwan and adopted a panel study to explore the changes in the external political efficacy of these students. On the basis of cognitive dissonance theory, rational choice, social identity, and political socialization theories were combined to create a theoretical model. The results showed that the mean external political efficacy of all students was significantly lowered by 0.18 units on a scale of 1 to 4. The proposed regression model explained 26.87 percent of the variance in the degree of changes in external political efficacy. Four hypotheses were empirically supported.
Randomized, double‐blind comparison of aripiprazole/sertraline combination and placebo/sertraline combination in patients with major depressive disorder
Authors: Kamijima Kunitoshi , Kimura Mahito , Kuwahara Kazuo , Kitayama Yuri , Tadori Yoshihiro
Published: April 2018

Aim

This study compared the efficacy and safety of aripiprazole/sertraline combination (ASC) and placebo/sertraline combination (PSC) in patients with major depressive disorder (MDD) who showed an inadequate response to sertraline 100 mg/day.

Methods

The study comprised a screening period, an 8‐week prospective treatment (single‐blind sertraline 25–100 mg/day) period, and a 6‐week double‐blind treatment period. Patients with DSM‐5‐defined MDD were enrolled. Following the prospective treatment, non‐responders were randomly assigned to the ASC group (aripiprazole 3–12 mg/day/sertraline 100 mg/day) or the PSC group (sertraline 100 mg/day). The primary efficacy end‐point was the mean change in the Montgomery–Åsberg Depression Rating Scale (MADRS) total score from baseline to 6 weeks.

Results

A total of 412 patients were randomly assigned to either the ASC group (n = 209) or the PSC group (n = 203). Mean change in MADRS total score was significantly greater in patients with ASC than PSC (−9.2 vs −7.2; P = 0.0070). Treatment‐emergent adverse events (TEAE) that occurred in ≥10% of patients with ASC versus PSC were nasopharyngitis (13.4% vs 11.3%) and akathisia (12.9% vs 3.4%). All TEAE reported in the ASC group were mild or moderate in severity. Rates of discontinuations due to TEAE were low in both the ASC (1.9%) and PSC (1.5%) groups. There were no notable issues in safety assessments in the ASC group compared with the PSC group.

Conclusion

In patients with MDD who showed an inadequate response to treatment with sertraline 100 mg/day, ASC was efficacious and well tolerated.
Depth camera indoor mapping for 3D virtual radio play
Authors: Virtanen Juho‐Pekka , Kurkela Matti , Turppa Tuomas , Vaaja Matti T. , Julin Arttu , Kukko Antero , Hyyppä Juha , Ahlavuo Marika , von Numers Jessica Edén , Haggrén Henrik , Hyyppä Hannu
Published: April 2018

By combining game engines with indoor mapping, it is possible to create interactive virtual environments that represent the real world. In this paper a virtual version of an audio installation in a historic building is produced, where the user freely explores the building and experiences a set of audio clips, creating a virtual radio play. A depth camera indoor mapping system, Matterport, captured a set of staged interiors. The aim was to evaluate the quality and usability of the indoor models and to demonstrate applying them in 3D application development. The quality of the models was evaluated by comparison with laser scanning, revealing limitations with Matterport: increasing the size of the measured area lowered the level of detail and accuracy of volumetric models. The quality of textures was not affected by this limitation, maintaining the appearance of models. To obtain optimised models for mobile 3D applications, a manual revision process was applied.
Managed flooding can augment the benefits of natural flooding for native wetland vegetation
Authors: Duong Alice , Greet Joe , Walsh Christopher J. , Sammonds Michael J.
Published: April 2018

Managed flooding is increasingly being used to maintain and restore the ecological values of floodplain wetlands. However, evidence for its effectiveness is sometimes inconsistent and water available for environmental purposes often limited. We experimentally inundated a floodplain wetland (or “billabong”) in late spring by pumping water from its adjacent creek, aiming to promote the native wetland flora and suppress terrestrial exotics. Vegetation was surveyed before (spring) and after (late summer) the managed flood in the experimental billabong and in three control billabongs. Floodplain water levels were continuously monitored. Wet conditions caused two of the control billabongs to also flood, but to a lesser extent than the experimental billabong. We therefore assessed vegetation changes relative to flooding duration. With increasing flooding duration, the cover of wetland vegetation (amphibious and aquatic species) increased and the cover of terrestrial and exotic vegetation decreased, with these effects largest in the deliberately flooded billabong. Flooding durations greater than 20 days generally resulted in increased cover of wetland plants and restricted the growth of terrestrial plants. Reinstatement of more appropriate flooding regimes can thus promote native wetland plants, while suppressing terrestrial exotic species. Our study also provides evidence for the use of modest water allocations to augment the benefits of natural flooding in the maintenance and restoration of native wetland plant communities.
Disparities in out‐of‐pocket inpatient expenditures in rural Shaanxi Province, western China from 2011 to 2014: a time series analysis
Authors: Yang Caijun , Cai Wenfang , Li Zongjie , Fang Yu
Published: April 2018

Objective

To investigate the long‐term trend of disparity of monthly average out‐of‐pocket inpatient expenditures (OOP) between areas with different developing levels since the new healthcare reform.

Methods

Time series regression was used to assess the trend of disparities of OOP and monthly average inpatient expenditures (AIE) between areas with different developing levels in rural Shaanxi Province, western China. The data of OOP and AIE in primary health institutions, secondary hospitals, tertiary hospitals and also all levels of the hospital were analysed separately covering the period 2011 through to 2014.

Results

The disparity of AIE at all levels of hospitals was increasing (coefficient = 0.003, P = 0.029), and only the disparity of AIE in secondary hospitals was statistical significant (coefficient = 0.003, P = 0.012) when separately considering different levels of the hospital. The disparity of OOP in all levels of the hospital was increasing (coefficient = 0.007, P = 0.001), and the OOP in primary hospitals contributed most of the disparity (coefficient = 0.019, P = 0.000), followed by OOP in secondary (coefficient = 0.008, P = 0.003) and tertiary hospitals (coefficient = 0.004, P = 0.091).

Conclusions

A statistically significant absolute increase in the trend of disparities of OOP and AIE at all levels of hospital was detected after the new healthcare reform in Shaanxi Province, western China. The increase rate of disparity of OOP was bigger than that of AIE. A modified health insurance plan should be proposed to guarantee equity in the future.
A critical role for Arabidopsis MILDEW RESISTANCE LOCUS O2 in systemic acquired resistance
Authors: Gruner Katrin , Zeier Tatyana , Aretz Christina , Zeier Jürgen
Published: April 2018

Members of the MILDEW RESISTANCE LOCUS O (MLO) gene family confer susceptibility to powdery mildews in different plant species, and their existence therefore seems to be disadvantageous for the plant. We recognized that expression of the Arabidopsis MLO2 gene is induced after inoculation with the bacterial pathogen Pseudomonas syringae, promoted by salicylic acid (SA) signaling, and systemically enhanced in the foliage of plants exhibiting systemic acquired resistance (SAR). Importantly, distinct mlo2 mutant lines were unable to systemically increase resistance to bacterial infection after inoculation with P. syringae, indicating that the function of MLO2 is necessary for biologically induced SAR in Arabidopsis. Our data also suggest that the close homolog MLO6 has a supportive but less critical role in SAR. In contrast to SAR, basal resistance to bacterial infection was not affected in mlo2. Remarkably, SAR‐defective mlo2 mutants were still competent in systemically increasing the levels of the SAR‐activating metabolites pipecolic acid (Pip) and SA after inoculation, and to enhance SAR‐related gene expression in distal plant parts. Furthermore, although MLO2 was not required for SA‐ or Pip‐inducible defense gene expression, it was essential for the proper induction of disease resistance by both SAR signals. We conclude that MLO2 acts as a critical downstream component in the execution of SAR to bacterial infection, being required for the translation of elevated defense responses into disease resistance. Moreover, our data suggest a function for MLO2 in the activation of plant defense priming during challenge by P. syringae.
Glutathione transferases catalyze recycling of auto‐toxic cyanogenic glucosides in sorghum
Authors: Bjarnholt Nanna , Neilson Elizabeth H. J. , Crocoll Christoph , Jørgensen Kirsten , Motawia Mohammed Saddik , Olsen Carl Erik , Dixon David P. , Edwards Robert , Møller Birger Lindberg
Published: April 2018

Cyanogenic glucosides are nitrogen‐containing specialized metabolites that provide chemical defense against herbivores and pathogens via the release of toxic hydrogen cyanide. It has been suggested that cyanogenic glucosides are also a store of nitrogen that can be remobilized for general metabolism via a previously unknown pathway. Here we reveal a recycling pathway for the cyanogenic glucoside dhurrin in sorghum (Sorghum bicolor) that avoids hydrogen cyanide formation. As demonstrated in vitro, the pathway proceeds via spontaneous formation of a dhurrin‐derived glutathione conjugate, which undergoes reductive cleavage by glutathione transferases of the plant‐specific lambda class (GSTLs) to produce p‐hydroxyphenyl acetonitrile. This is further metabolized to p‐hydroxyphenylacetic acid and free ammonia by nitrilases, and then glucosylated to form p‐glucosyloxyphenylacetic acid. Two of the four GSTLs in sorghum exhibited high stereospecific catalytic activity towards the glutathione conjugate, and form a subclade in a phylogenetic tree of GSTLs in higher plants. The expression of the corresponding two GSTLs co‐localized with expression of the genes encoding the p‐hydroxyphenyl acetonitrile‐metabolizing nitrilases at the cellular level. The elucidation of this pathway places GSTs as key players in a remarkable scheme for metabolic plasticity allowing plants to reverse the resource flow between general and specialized metabolism in actively growing tissue.
BEL1‐LIKE HOMEODOMAIN 11 regulates chloroplast development and chlorophyll synthesis in tomato fruit
Authors: Meng Lanhuan , Fan Zhongqi , Zhang Qiang , Wang Cuicui , Gao Ying , Deng Yikang , Zhu Benzhong , Zhu Hongliang , Chen Jianye , Shan Wei , Yin Xueren , Zhong Silin , Grierson Donald , Jiang Cai‐Zhong , Luo Yunbo , Fu Da‐Qi
Published: April 2018

Chloroplast development and chlorophyll(Chl)metabolism in unripe tomato contribute to the growth and quality of the fruit, however these mechanisms are poorly understood. In this study, we initially investigated seven homeobox‐containing transcription factors (TFs) with specific ripening‐associated expression patterns using virus‐induced gene silencing (VIGS) technology and found that inhibiting the expression of one of these TFs, BEL1‐LIKE HOMEODOMAIN11 (SlBEL11), significantly increased Chl levels in unripe tomato fruit. This enhanced Chl accumulation was further validated by generating stable RNA interference (RNAi) transgenic lines. RNA sequencing (RNA‐seq) of RNAi‐SlBEL11 fruit at the mature green (MG) stage showed that 48 genes involved in Chl biosynthesis, photosynthesis and chloroplast development were significantly upregulated compared with the wild type (WT) fruit. Genomic global scanning for Homeobox TF binding sites combined with RNA‐seq differential gene expression analysis showed that 22 of these 48 genes were potential target genes of SlBEL11 protein. These genes included Chl biosynthesis‐related genes encoding for protochlorophyllide reductase (POR), magnesium chelatase H subunit (CHLH) and chlorophyllide a oxygenase (CAO), and chloroplast development‐related genes encoding for chlorophyll a/b binding protein (CAB), homeobox protein knotted 2 (TKN2) and ARABIDOPSIS PSEUDO RESPONSE REGULATOR 2‐LIKE (APRR2‐like). Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation quantitative polymerase chain reaction (PCR) (ChIP‐qPCR) assays were employed to verify that SlBEL11 protein could bind to the promoters for TKN2, CAB and POR. Taken together, our findings demonstrated that SlBEL11 plays an important role in chloroplast development and Chl synthesis in tomato fruit.
Genome‐wide Hi‐C analysis reveals extensive hierarchical chromatin interactions in rice
Authors: Dong Qianli , Li Ning , Li Xiaochong , Yuan Zan , Xie Dejian , Wang Xiaofei , Li Jianing , Yu Yanan , Wang Jinbin , Ding Baoxu , Zhang Zhibin , Li Changping , Bian Yao , Zhang Ai , Wu Ying , Liu Bao , Gong Lei
Published: April 2018

The non‐random spatial packing of chromosomes in the nucleus plays a critical role in orchestrating gene expression and genome function. Here, we present a Hi‐C analysis of the chromatin interaction patterns in rice (Oryza sativa L.) at hierarchical architectural levels. We confirm that rice chromosomes occupy their own territories with certain preferential inter‐chromosomal associations. Moderate compartment delimitation and extensive TADs (Topologically Associated Domains) were determined to be associated with heterogeneous genomic compositions and epigenetic marks in the rice genome. We found subtle features including chromatin loops, gene loops, and off‐/near‐diagonal intensive interaction regions. Gene chromatin loops associated with H3K27me3 could be positively involved in gene expression. In addition to insulated enhancing effects for neighbor gene expression, the identified rice gene loops could bi‐directionally (+/−) affect the expression of looped genes themselves. Finally, web‐interleaved off‐diagonal IHIs/KEEs (Interactive Heterochromatic Islands or KNOT ENGAGED ELEMENTs) could trap transposable elements (TEs) via the enrichment of silencing epigenetic marks. In parallel, the near‐diagonal FIREs (Frequently Interacting Regions) could positively affect the expression of involved genes. Our results suggest that the chromatin packing pattern in rice is generally similar to that in Arabidopsis thaliana but with clear differences at specific structural levels. We conclude that genomic composition, epigenetic modification, and transcriptional activity could act in combination to shape global and local chromatin packing in rice. Our results confirm recent observations in rice and A. thaliana but also provide additional insights into the patterns and features of chromatin organization in higher plants.
GNA11 differentially mediates fibroblast growth factor 2‐ and vascular endothelial growth factor A‐induced cellular responses in human fetoplacental endothelial cells
Authors: Zou Qing‐yun , Zhao Ying‐jie , Li Hua , Wang Xiang‐zhen , Liu Ai‐xia , Zhong Xin‐qi , Yan Qin , Li Yan , Zhou Chi , Zheng Jing
Published: April 2018

Key points

Fetoplacental vascular growth is critical to fetal growth. Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGFA) are two major regulators of fetoplacental vascular growth. G protein α subunit 11 (GNA11) transmits signals from many external stimuli to the cellular interior and may mediate endothelial function.

It is not known whether GNA11 mediates FGF2‐ and VEGFA‐induced endothelial cell responses under physiological chronic low O2.

In the present study, we show that knockdown of GNA11 significantly decreases FGF2‐ and VEGFA‐induced fetoplacental endothelial cell migration but not proliferation and permeability.

Such decreases in endothelial migration are associated with increased phosphorylation of phospholipase C‐β3.

The results of the present study suggest differential roles of GNA11 with respect to mediating FGF2‐ and VEGFA‐induced fetoplacental endothelial function.

During pregnancy, fetoplacental angiogenesis is dramatically increased in association with rapidly elevated blood flow. Any disruption of fetoplacental angiogenesis may lead to pregnancy complications such as intrauterine growth restriction. Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGFA) are crucial regulators of fetoplacental angiogenesis. G protein α subunits q (GNAq) and 11 (GNA11) are two members of the Gαq/11 subfamily involved in mediating vascular growth and basal blood pressure. However, little is known about the roles of GNA11 alone with respect to mediating the FGF2‐ and VEGFA‐induced fetoplacental endothelial function. Using a cell model of human umbilical cord vein endothelial cells cultured under physiological chronic low O2 (3% O2), we showed that GNA11 small interfering RNA (siRNA) dramatically inhibited (P < 0.05) FGF2‐ and VEGFA‐stimulated fetoplacental endothelial migration (by ∼36% and ∼50%, respectively) but not proliferation and permeability. GNA11 siRNA also elevated (P < 0.05) FGF2‐ and VEGFA‐induced phosphorylation of phospholipase C‐β3 (PLCβ3) at S537 in a time‐dependent fashion but not mitogen‐activated protein kinase 3/1 (ERK1/2) and v‐akt murine thymoma viral oncogene homologue 1 (AKT1). These data suggest that GNA11 mediates FGF2‐ and VEGFA‐stimulated fetoplacental endothelial cell migration partially via altering the activation of PLCβ3.
Anuncio de fusiones y adquisiciones y su efecto en los retornos accionarios: Chile, 2010-2014
Authors: Améstica Rivas Luis , Campos Fuentes Danilo Alexis , Cornejo Saavedra Edinson Edgardo
Published: April 2018

Este estudio analiza 61 anuncios de fusiones y adquisiciones (F&A) –realizados entre 2010 y 2014 por 30 firmas chilenas– y sus efectos sobre los precios accionarios; y busca retornos anormales en los días previos, que podrían relacionarse con el uso de información privilegiada y un problema de insider. Mediante un estudio de eventos se estiman los retornos anormales promedio (AR) ocurridos antes y después del anuncio de F&A. En las adquisiciones, en el día previo el AR es positivo (0,60%-0,89%) y significativo; y el retorno anormal promedio acumulado entre los seis días previos también es positivo y significativo (2,30%-2,48%). Esto revelaría una filtración de información privada y un problema de insider. En las fusiones, los resultados no son concluyentes.
Estimación de la probabilidad de riesgo de quiebra en las empresas colombianas a partir de un modelo para eventos raros.
Authors: Pérez García Jorge Iván , Lopera Castaño Mauricio , Vásquez Bedoya Fredy Alonso
Published: April 2018

Para discriminar en riesgo de quiebra y no quiebra a las empresas colombianas que reportaron sus estados financieros a la Superintendencia de Sociedades de Colombia para el periodo 2011-2015, este trabajo considera la quiebra como un evento raro y emplea un modelo logístico, un modelo aditivo generalizado, un modelo de valor extremo generalizado y un modelo binario aditivo de valor extremo generalizado (BGEVA). En términos comparativos, el modelo BGEVA presenta mejor desempeño predictivo con respecto a los otros al asumir una distribución de valor extremo en la función link y estructuras semi-paramétricas en las estimaciones, permitiendo así determinar la relación existente entre la probabilidad de default y las variables explicativas.
Escuelas inclusivas: aprendizaje cooperativo y TAC con alumnado con TDAH
Authors: Latorre-Cosculluela Cecilia , Liesa-Orús Marta , Vázquez-Toledo Sandra
Published: April 2018

En este artículo, mediante una revisión teórica, se analizan las prácticas inclusivas más eficaces implementadas con alumnado con Trastorno por Déficit de Atención e Hiperactividad (TDAH), haciendo especial mención al modelo Making Socially Accepting Inclusive Classrooms (MOSAIC) y a la mediación entre iguales como elementos fundamentales de trabajo del aprendizaje cooperativo y las prácticas inclusivas en las escuelas. Finalmente, se hace hincapié en la utilización de las Tecnologías del Aprendizaje y la Comunicación y otras metodologías globalizadoras con grupos de alumnado con TDAH.
Estudio de la discriminación auditiva en educación infantil en Valencia
Authors: Botella-Nicolás Ana María , Peiró-Esteve María De Los Ángeles
Published: April 2018

Este estudio se centra en conocer en qué grado los tutores de 2º ciclo de Educación Infantil de las escuelas públicas de Valencia (España) trabajan el lenguaje musical en sus alumnos, con el fin de analizar la importancia que le atribuyen a la estimulación auditiva temprana por medio del desarrollo de la discriminación de sonidos musicales y su didáctica. La investigación es cuantitativa-cualitativa, por encuesta con cuestionario, administrado a 95 tutores. Como resultado, se confirma la escasa estimulación que reciben los niños y la necesidad de ofertar más cursos de formación en didáctica musical para este colectivo docente.
El estudio del formador latinoamericano: un campo de investigación ‘en construcción’
Authors: González-Vallejos María Paz
Published: April 2018

Se presenta una revisión sistemática de literatura latinoamericana sobre el formador, para articular un panorama de su estudio en la región entre 2005 y 2016. Se identifican como países de producción de estos artículos Argentina, Brasil, Chile, Colombia, Guatemala, México, Uruguay y Venezuela. Utilizando un análisis temático, se identifican tópicos y metodologías en los estudios revisados; así mismo, conclusiones y desafíos para la investigación sobre el formador. Se concluye que el formador como objeto de investigación en Latinoamérica es un campo con escaso avance teórico y empírico, es decir, se encuentra en ‘proceso de construcción’. Se proponen orientaciones para la investigación.
Educación interactiva a través de narrativas transmedia: posibilidades en la escuela
Authors: Amador-Baquiro Juan Carlos
Published: April 2018

El artículo presenta parte de los resultados de una investigación que indagó las formas de interactividad alcanzadas por estudiantes de básica primaria y secundaria de Bogotá, en ambientes que fomentaron estilos comunicativos todostodos, y cuyos contenidos de aprendizaje se basaron en la producción participativa de narrativas transmedia. Además de exponer los referentes teóricos del trabajo, se expone la metodología de la investigación, la cual se apoyó en el enfoque cualitativo y en la etnografía convencional y virtual. Al final se analizan los resultados, haciendo énfasis en la importancia de la comunicación bidireccional al trabajar con contenidos digitales, y en el uso de técnicas como la remediación y la hibridación en la construcción de narrativas transmedia.
Miradas urbanas del profesorado iberoamericano desde la cultura visual
Authors: Huerta Ricard
Published: April 2018

Nos interesa conocer si hay una mirada propia del profesorado hacia la realidad urbana. Partimos de descripciones tanto verbales como visuales, mediante imágenes y textos. La investigación se ha desarrollado en Santiago de Chile, Valencia, Lima, Medellín, Montevideo y Buenos Aires, y combina acciones participativas directas con entrevistas personales. La metodología es mixta y parte de un estudio de caso que se complementa con la investigación basada en las artes. Comprobamos que sí hay una mirada particular del colectivo docente hacia su propia ciudad, cargada de reflexión crítica. Se trata de un tema poco abordado que precisa mayor atención.
Prácticas docentes, clima social, seguridad escolar y violencia entre estudiantes
Authors: Valdés-Cuervo Ángel Alberto , Tánori-Quintana Jesús , Sotelo-Quiñonez Teresa Iveth , Ochoa-Arreola José Alán
Published: April 2018

El contexto escolar previene el acoso escolar. El estudio analizó las relaciones entre las prácticas docentes de intervención directa, la seguridad, el clima escolar y el acoso entre estudiantes. La muestra se compone de 291 estudiantes con edades entre 9 y 13 años (M = 10.94, DE = 2.77) de 17 escuelas primarias de un estado de México. Los resultados de la regresión lineal sugieren que las prácticas de intervención directa, la seguridad y un clima escolar positivo disminuyen el acoso. Se concluye que las variables involucradas en el estudio previenen el acoso. Finalmente, se discuten implicaciones de los hallazgos.
Pathogenic Effects of IFIT2 and Interferon-β during Fatal Systemic Candida albicans Infection
Authors: Stawowczyk Marcin , Naseem Shamoon , Montoya Valeria , Baker Darren P. , Konopka James , Reich Nancy C.
Published: April 2018

A balanced immune response to infection is essential to prevent the pathology and tissue damage that can occur from an unregulated or hyperactive host defense. Interferons (IFNs) are critical mediators of the innate defense to infection, and in this study we evaluated the contribution of a specific gene coding for IFIT2 induced by type I IFNs in a murine model of disseminatedCandida albicans. Invasive candidiasis is a frequent challenge during immunosuppression or surgical medical interventions, andC. albicansis a common culprit that leads to high rates of mortality. When IFIT2 knockout mice were infected systemically withC. albicans, they were found to have improved survival and reduced fungal burden compared to wild-type mice. One of the mechanisms by which IFIT2 increases the pathological effects of invasiveC. albicansappears to be suppression of NADPH oxidase activation. Loss of IFIT2 increases production of reactive oxygen species by leukocytes, and we demonstrate that IFIT2 is a binding partner of a critical regulatory subunit of NADPH oxidase, p67phox. Since the administration of IFN has been used therapeutically to combat viral infections, cancer, and multiple sclerosis, we evaluated administration of IFN-β to mice prior toC. albicansinfection. IFN-β treatment promoted pathology and death fromC. albicansinfection. We provide evidence that IFIT2 increases the pathological effects of invasiveC. albicansand that administration of IFN-β has deleterious effects during infection.

IMPORTANCEThe attributable mortality associated with systemicC. albicansinfections in health care settings is significant, with estimates greater than 40%. This life-threatening disease is common in patients with weakened immune systems, either due to disease or as a result of therapies. Type I interferons (IFN) are cytokines of the innate defense response that are used as immune modulators in the treatment of specific cancers, viral infections, and multiple sclerosis. In this study, we show using a murine model that the loss of a specific IFN-stimulated gene coding for IFIT2 improves survival following systemicC. albicansinfection. This result infers a harmful effect of IFN duringC. albicansinfection and is supported by our finding that administration of IFN-β prior to invasive infection promotes fatal pathology. The findings contribute to our understanding of the innate immune response toC. albicans, and they suggest that IFN therapies present a risk factor for disseminated candidiasis.
Viable-but-Nonculturable Listeria monocytogenes and Salmonella enterica Serovar Thompson Induced by Chlorine Stress Remain Infectious
Authors: Highmore Callum J. , Warner Jennifer C. , Rothwell Steve D. , Wilks Sandra A. , Keevil C. William
Published: April 2018

The microbiological safety of fresh produce is monitored almost exclusively by culture-based detection methods. However, bacterial food-borne pathogens are known to enter a viable-but-nonculturable (VBNC) state in response to environmental stresses such as chlorine, which is commonly used for fresh produce decontamination. Here, complete VBNC induction of green fluorescent protein-tagged
Listeria monocytogenes
and
Salmonella enterica
serovar Thompson was achieved by exposure to 12 and 3 ppm chlorine, respectively. The pathogens were subjected to chlorine washing following incubation on spinach leaves. Culture data revealed that total viable
L. monocytogenes
and
Salmonella
Thompson populations became VBNC by 50 and 100 ppm chlorine, respectively, while enumeration by direct viable counting found that chlorine caused a <1-log reduction in viability. The pathogenicity of chlorine-induced VBNC
L. monocytogenes
and
Salmonella
Thompson was assessed by using
Caenorhabditis elegans
. Ingestion of VBNC pathogens by
C. elegans
resulted in a significant life span reduction (
P
= 0.0064 and
P
< 0.0001), and no significant difference between the life span reductions caused by the VBNC and culturable
L. monocytogenes
treatments was observed.
L. monocytogenes
was visualized beyond the nematode intestinal lumen, indicating resuscitation and cell invasion. These data emphasize the risk that VBNC food-borne pathogens could pose to public health should they continue to go undetected.

IMPORTANCE
Many bacteria are known to enter a viable-but-nonculturable (VBNC) state in response to environmental stresses. VBNC cells cannot be detected by standard laboratory culture techniques, presenting a problem for the food industry, which uses these techniques to detect pathogen contaminants. This study found that chlorine, a sanitizer commonly used for fresh produce, induces a VBNC state in the food-borne pathogens
Listeria monocytogenes
and
Salmonella enterica
. It was also found that chlorine is ineffective at killing total populations of the pathogens. A life span reduction was observed in
Caenorhabditis elegans
that ingested these VBNC pathogens, with VBNC
L. monocytogenes
as infectious as its culturable counterpart. These data show that VBNC food-borne pathogens can both be generated and avoid detection by industrial practices while potentially retaining the ability to cause disease.
The Blast Fungus Decoded: Genomes in Flux
Authors: Langner Thorsten , Białas Aleksandra , Kamoun Sophien
Published: April 2018

Plant disease outbreaks caused by fungi are a chronic threat to global food security. A prime case is blast disease, which is caused by the ascomycete fungus
Magnaporthe oryzae
(syn.
Pyricularia oryzae
), which is infamous as the most destructive disease of the staple crop rice. However, despite its Linnaean binomial name,
M. oryzae
is a multihost pathogen that infects more than 50 species of grasses. A timely study by P. Gladieux and colleagues (mBio 9:e01219-17, 2018,
https://doi.org/10.1128/mBio.01219-17
) reports the most extensive population genomic analysis of the blast fungus thus far.
M. oryzae
consists of an assemblage of differentiated lineages that tend to be associated with particular host genera. Nonetheless, there is clear evidence of gene flow between lineages consistent with maintaining
M. oryzae
as a single species. Here, we discuss these findings with an emphasis on the ecologic and genetic mechanisms underpinning gene flow. This work also bears practical implications for diagnostics, surveillance, and management of blast diseases.
Human Immunodeficiency Virus Tat Protein Aids V Region Somatic Hypermutation in Human B Cells
Authors: Wang Xiaohua , Duan Zhi , Yu Guojun , Fan Manxia , Scharff Matthew D.
Published: April 2018

Long-term survivors of human immunodeficiency virus (HIV) infection have been shown to have a greatly increased incidence of B cell lymphomas. This increased lymphomagenesis suggests some link between HIV infection and the destabilization of the host B cell genome, a phenomenon also suggested by the extraordinary high frequency of mutation, insertion, and deletion in the broadly neutralizing HIV antibodies. Since HIV does not infect B cells, the molecular mechanisms of this genomic instability remain to be fully defined. Here, we demonstrate that the cell membrane-permeable HIV Tat proteins enhance activation-induced deaminase (AID)-mediated somatic hypermutation (SHM) of antibody V regions through their modulation of the endogenous polymerase II (Pol II) transcriptional process. Extremely small amounts of Tat that could come from bystander HIV-infected cells were sufficient to promote SHM. Our data suggest HIV Tat is one missing link between HIV infection and the overall B cell genomic instability in AIDS patients.

IMPORTANCE
Although the introduction of antiretroviral therapy (ART) has successfully controlled primary effects of human immunodeficiency virus (HIV) infection, such as HIV proliferation and HIV-induced immune deficiency, it did not eliminate the increased susceptibility of HIV-infected patients to B cell lymphomas. We find that a secreted HIV protein, Tat, enhances the intrinsic antibody diversification mechanism by increasing the AID-induced somatic mutations at the heavy-chain variable (VH) regions in human B cells. This could contribute to the high rate of mutation in the variable regions of broadly neutralizing anti-HIV antibodies and the genomewide mutations leading to B cell malignancies in HIV carriers.
Prevention of rickets and osteomalacia in the UK: political action overdue
Authors: Uday Suma , Högler Wolfgang
Published: April 2018

The consequences of vitamin D and dietary calcium deficiency have become a huge public health concern in the UK. The burden of disease from these deficiencies includes rickets, and hypocalcaemic seizures, dilated cardiomyopathy and mostly occult myopathy and osteomalacia. The increasing burden of the disease is intrinsically linked to ethnicity and the population demographic changes in the UK. Three facts have led to the resurfacing of the English disease: (1) the UK has no ultraviolet sunlight for at least 6 months of the year, (2) dark skin produces far less vitamin D than white skin per unit ultraviolet light exposure, and (3) non-European Union immigration over the last century. To date, the UK government demonstrates incomplete understanding of these three facts, and its failure to adjust its prevention programmes to changing demographics is endangering the health and life of UK residents with dark skin, of whom infants are the most vulnerable. Establishing accountability through the implementation of monitored antenatal and infantile supplementation programmes and mandatory food fortification is overdue.
Hadamard Directional Differentiability of the Optimal Value Function of a Quadratic Programming Problem
Authors: Zhang Sainan , Zhang Liwei , Zhang Hongwei , Duan Qingsong
Published: April 2018

In this paper, we consider the stability analysis of a convex quadratic programming (QP) problem and its restricted Wolfe dual when all parameters in the problem are perturbed. Based on the continuity of the feasible set mapping, we establish the upper semi-continuity of the optimal solution mappings of the convex QP problem and the restricted Wolfe dual problem. Furthermore, by characterizing the optimal value function as a min–max optimization problem over two compact convex sets, we demonstrate the Lipschitz continuity and the Hadamard directional differentiability of the optimal value function.
Long-Term Dependency Structure and Structural Breaks: Evidence from the U.S. Sector Returns and Volatility
Authors: Ngene Geoffrey , Mungai Ann Nduati , Lynch Allen K.
Published: April 2018

The study investigates the impact of structural breaks on the long memory of daily returns and variance of 11 sectors. Using multiple sequential structural breaks tests, we uncover numerous and roughly shared structural breaks. Results from two non-parametric, three semi-parametric, and three parametric fractional differencing models using break-adjusted and break-unadjusted returns reveal incidence of short memory and anti-persistence in sector returns. Regarding variance, we find that the removal of breaks from the sector series dampens the fractional differencing parameter estimates. Therefore, the observed long memory in variance may be attributable to the occurrence of structural breaks in the sector series.
Engineering Self-Adaptive Software Systems
Authors: Angelopoulos Konstantinos , Papadopoulos Alessandro V. , Souza Vítor E. Silva , Mylopoulos John
Published: April 2018

Self-adaptive software systems monitor their operation and adapt when their requirements fail due to unexpected phenomena in their environment. This article examines the case where the environment changes dynamically over time and the chosen adaptation has to take into account such changes. In control theory, this type of adaptation is known as Model Predictive Control and comes with a well-developed theory and myriad successful applications. The article focuses on modeling the dynamic relationship between requirements and possible adaptations. It then proposes a controller that exploits this relationship to optimize the satisfaction of requirements relative to a cost function. This is accomplished through a model-based framework for designing self-adaptive software systems that can guarantee a certain level of requirements satisfaction over time by dynamically composing adaptation strategies when necessary. The proposed framework is illustrated and evaluated through two simulated systems, namely, the Meeting-Scheduling exemplar and an E-Shop.
Flexible and Efficient Decision-Making for Proactive Latency-Aware Self-Adaptation
Authors: Moreno Gabriel A. , Cámara Javier , Garlan David , Schmerl Bradley
Published: April 2018

Proactive latency-aware adaptation is an approach for self-adaptive systems that considers both the current and anticipated adaptation needs when making adaptation decisions, taking into account the latency of the available adaptation tactics. Since this is a problem of selecting adaptation actions in the context of the probabilistic behavior of the environment, Markov decision processes (MDPs) are a suitable approach. However, given all the possible interactions between the different and possibly concurrent adaptation tactics, the system, and the environment, constructing the MDP is a complex task. Probabilistic model checking has been used to deal with this problem, but it requires constructing the MDP every time an adaptation decision is made to incorporate the latest predictions of the environment behavior. In this article, we describe PLA-SDP, an approach that eliminates that runtime overhead by constructing most of the MDP offline. At runtime, the adaptation decision is made by solving the MDP through stochastic dynamic programming, weaving in the environment model as the solution is computed. We also present extensions that support different notions of utility, such as maximizing reward gain subject to the satisfaction of a probabilistic constraint, making PLA-SDP applicable to systems with different kinds of adaptation goals.
Ground State Connectivity of Local Hamiltonians
Authors: Gharibian Sevag , Sikora Jamie
Published: April 2018

The study of ground state energies of local Hamiltonians has played a fundamental role in quantum complexity theory. In this article, we take a new direction by introducing the physically motivated notion of “ground state connectivity” of local Hamiltonians, which captures problems in areas ranging from quantum stabilizer codes to quantum memories. Roughly, “ground state connectivity” corresponds to the natural question: Given two ground states |Ψ〉 and |ϕ〉 of a local Hamiltonian
H
, is there an “energy barrier” (with respect to
H
) along any sequence of local operations mapping |Ψ〉 to |ϕ〉? We show that the complexity of this question can range from QCMA-complete to PSPACE-complete, as well as NEXP-complete for an appropriately defined “succinct” version of the problem. As a result, we obtain a natural QCMA-complete problem, a goal which has generally proven difficult since the conception of QCMA over a decade ago. Our proofs rely on a new technical tool, the Traversal Lemma, which analyzes the Hilbert space a local unitary evolution must traverse under certain conditions. We show that this lemma is essentially tight with respect to the length of the unitary evolution in question.
The Substitution Effect on Reaction Enthalpies of Antioxidant Mechanisms of Juglone and Its Derivatives in Gas and Solution Phase: DFT Study
Authors: Fouegue Aymard Didier Tamafo , Mama Désiré Bikélé , Ghogomu Julius Numbonui , Elie Younang , Etoh Marie-Annie
Published: April 2018

We examined the structure-reaction enthalpies-antioxidant activity relationship of the molecule library built around juglone and its derivatives at B3LYP/6-31+G(d,p) level. Three major antioxidant mechanisms (hydrogen atom transfer (HAT), single electron transfer-proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET)) have been investigated in five solvents and in the gas phase. The delocalization of the unpaired electrons in the radicals or cation radicals has been explored by the natural bond orbital analysis and the interpretation of spin density maps. The results obtained have proven that the HAT mechanism is the thermodynamically preferred mechanism in the gas phase. But, in the solution phase, the SPLET mechanism has been shown to be more predominant than HAT. The reactivity order of compounds towards selected reactive oxygen species has also been studied.
Nurses Practice of Hand Hygiene in Hiwot Fana Specialized University Hospital, Harari Regional State, Eastern Ethiopia: Observational Study
Authors: Awoke Nefsu , Geda Biftu , Arba Aseb , Tekalign Tiwabwork , Paulos Kebreab
Published: April 2018

Background. Nurses, who are the majority, can contaminate their hands with different types of microorganism during “clean” activities (e.g., lifting a patient; taking a patient’s pulse, blood pressure, or oral temperature; or touching a patient’s hand, shoulder, or groin). Yet good hand hygiene, the simple task of cleaning hands at the right time and in the right way, can reduce HCAIs that are transmitted by healthcare workers’ hands. Method. Observational study conducted among nurses by observational tool which was adopted from WHO observational tool. And finally compliance was calculated as a percentage (i.e., compliance% = (observed hand hygiene action (HHA) ÷ hand hygiene opportunity (O)) × 100). The data were first coded, entered, and cleaned using EpiData statistical software version 3.1 and then exported into SPSS statistical software version 22 for analysis. Data were presented using descriptive statistics. Result. A total of 110 study participants were observed who gave a response rate of 94.8%. Total of 3902 opportunities and 732 hand hygiene actions were observed with overall compliance of 18.7%. The highest 22.9% hand hygiene practice was observed “before clean∖aseptic procedure.” Highest 19.6% compliance was recorded at night shift and 22.7% in ICU ward of the hospital. Alcohol based hand rub was a major means of method used to clean hands. Conclusion and Recommendation. Observed practice of hand hygiene was poor. Lack of training, conveniently located sink, hand washing agents, and lack of time were major reasons for not practicing hand hygiene. Successful promotion of hand hygiene through instituting system change (e.g., making hand hygiene products available at the point of care) should be considered.
Trajectory Stability in the Traveling Salesman Problem
Authors: Sánchez Sergio , Cocho Germinal , Flores Jorge , Gershenson Carlos , Iñiguez Gerardo , Pineda Carlos
Published: April 2018

Two generalizations of the traveling salesman problem in which sites change their position in time are presented. The way the rank of different trajectory lengths changes in time is studied using the rank diversity. We analyze the statistical properties of rank distributions and rank dynamics and give evidence that the shortest and longest trajectories are more predictable and robust to change, that is, more stable.
Applications of Mesenchymal Stem Cells in Sinus Lift Augmentation as a Dental Implant Technology
Authors: Parnia Feridoun , Yazdani Javad , Maleki Dizaj Solmaz
Published: April 2018

The potential application of stem cell biology in human dentistry is a new and emerging field of research. The objective of the current review was to study the efficiency of mesenchymal stem cells (MSCs) in sinus lift augmentation (SLA). A literature review was performed in PubMed Central using MeSH keywords such as sinus lift, MSCs, dental implants, and augmentation. The searches involved full-text papers written in English, published in the past 10 years (2007–2017). The review included in vitro and in vivo studies on the use of MSCs in SLA. Electronic searching provided 45 titles, and among them, 8 papers were chosen as suitable based on the inclusion requirements of this review. The reviewed studies have revealed the potential of MSCs in SLA. According to these papers, stem cell therapy combined with different biomaterials may considerably improve bone regeneration in previous steps of dental implantation and may veritably lead to efficient clinical usages in the recent future. However, the identification of an ideal source of stem cells as well as long-term studies is vital to assess the success rate of this technology. Further clinical trials are also needed to approve the potential of MSCs in SLA.