Glutamine Phosphoribosylpyrophosphate Amidotransferase-independent Phosphoribosyl Amine Synthesis from Ribose 5-Phosphate and Glutamine or Asparagine

Phosphoribosylamine (PRA) is the first intermediate in the common pathway to purines and thiamine and is generated in bacteria by glutamine phosphoribosylpyrophosphate (PRPP) amidotransferase (EC 2.4.2.14) from PRPP and glutamine. Genetic data have indicated that multiple, non-PRPP amidotransferase mechanisms exist to generate PRA sufficient for thiamine but not purine synthesis. Here we describe the purification and identification of an activity (present in both Escherichia coli and Salmonella enterica) that synthesizes PRA from ribose 5-phosphate and glutamine/asparagine. A purification resulting in greater than a 625-fold increase in specific activity identified 8 candidate proteins. Of the candidates, overexpression of AphA (EC 3.1.3.2), a periplasmic class B nonspecific acid phosphatase, significantly increased activity in partially purified extracts. Native purification of AphA to >95% homogeneity determined that the periplasmic L-asparaginase II, AnsB (EC 3.5.1.1), co-purified with AphA and was also necessary for PRA formation. The potential physiological relevance of AphA and AnsB in contributing to thiamine biosynthesis in vivo is discussed

Effects of bilingual intervention on alphabet knowledge and emergent literacy skills

This research study explored the effects of bilingual intervention on the development of alphabet knowledge and emergent literacy skills in bilingual kindergarten students. The study consisted of 15 African- American or Hispanic participants’ ages five and six, 7 of which were part of the intervention group. The intervention group received explicit bilingual literacy instruction for six weeks. Three major findings were 1) student participants experienced increased alphabet knowledge in their first and second language 2) students demonstrated growth in emergent literacy skills in their first language and 3), the students’ first language development was not negatively affected by the bilingual intervention in the second language. The results indicate that explicit bilingual intervention is beneficial for the development of alphabet knowledge and emergent literacy skills

Desarrollo psicocultural de niños mexicanos

En México habitan más de 30 millones de niños en contextos urbanos, rurales o indígenas, con niveles socieconómicos diferentes, que comparten múltiples aspectos de una historia milenaria que dio fruto a un país que es una rica mezcla de culturas, etnias y lenguas. Su situación solo se puede estudiar a partir de esta realidad multifacética. Este libro aspira a mejorar la comprensión de los diversos aspectos socioculturales que afectan el desarrollo psicológico y la vida de los niños mexicanos. Para ello, se presenta una panorámica de contextos y situaciones particulares que permiten identificar cómo en la niñez la historia individual o grupal tiene implicaciones relevantes en los aprendizajes, el comportamiento social y la evolución emocional y cognitiva. Asimismo, se brindan pistas para entender y atender mejor las necesidades de los niños en México, ya sea en el seno familiar, el ámbito escolar o a través de la implementación de políticas públicas efectivas.ITESO, A.C

Differences in the cyanobacterial community composition of biocrusts from the Drylands of Central Mexico. Are there endemic species?

In drylands worldwide, biocrusts, topsoil microbial communities, are prevalent, contributing to the biostabilization of soils and allowing the subsequent establishment and growth of vascular plants. In early successional biocrusts, cyanobacteria are the first dominant colonizers of bare ground, largely determining their functioning. However, there are large gaps in our knowledge of the cyanobacterial diversity in biocrusts, particularly in understudied geographic regions, such as the tropical latitudes. We analyzed the diversity of the cyanobacteria inhabiting the biocrusts of semideserts from Central Mexico in two localities belonging to the same desert system (Chihuahuan Desert) that are separated by a cordillera that crosses the center of Mexico. Morphological identification of the cyanobacteria was carried out after cultivation in parallel with the direct observation of the environmental samples and was supported by genetic characterization through analysis of the 16S rRNA gene of the isolated strains and by next-generation sequencing of the soil samples. Taxonomic assignment revealed a clear dominance of heterocystous cyanobacteria at one of the studied locations (Actopan, Hidalgo state). Although heterocystous forms were abundant at the other location (Atexcac, Puebla state), almost a third of the cyanobacterial phylotypes were represented by unicellular/colonial cyanobacteria, mostly Chroococcidiopsis spp. Only 28.4% of the phylotypes were found to be common to both soils. Most of the other taxa, however, were biocrust-type specific, and approximately 35% of the phylotypes were found to be unique to the soil they were collected in. In addition, differences in the abundances of the shared cyanobacteria between the locations were also found. These differences in the cyanobacterial distribution were supported by the distinct responses of the isolated strains representative of the sites to extreme heat and desiccation in bioassays. Some cyanobacteria with high abundance or only present at the hottest Actopan site, such as Scytonema hyalinum, Scytonema crispum, Nostoc commune, Nostoc sp., and Calothrix parietina, survived extreme heat and desiccation.However, Tolypothrix distorta and Chroococcidiopsis spp. were clearly sensitive to these extreme conditions in relation to their lower abundances at Actopan as opposed to Atexcac. Since novel biocrust-associated phylotypes were also found, the emergence of endemic cyanobacterial taxa is discussedThis study was supported by grants from the Spanish Government and European Regional Funds (CGL2013-44870-R and CGL2017-86258-R) and by a grant from the Universidad Autónoma de Madrid and Banco de Santander (CEAL-AL/2017-10). IB-A acknowledges support from CONACyT-Mexico postdoctoral fellowship at Universidad Autónoma de Madri

Portrayal of hearing loss in YouTube videos: An exploratory cross-sectional analysis

Objective: The objective of the current study was to examine the source, content, understandability and actionability of hearing loss information on YouTube videos. Method: The study used a cross-sectional design. One hundred of the most frequently viewed YouTube videos were identified and various data were manually coded (i.e., video source, video content, popularity measures such as number of views, likes, and dislikes). In addition, the understandability and actionability of each video were evaluated using the Patient Education Materials Assessment Tool for Audiovisual Martials (PEMAT-AV) rating scale. Results: Of the 100 most viewed videos, 16 were created by consumers, 62 were professional-created, and 22 were media-based. Symptoms, causes and treatment or management of hearing loss were the most frequently discussed content categories with over 60% of all videos commenting on these areas. The overall understandability and actionability scores for the 100 videos included were 77% and 31% respectively indicating adequate understandability and poor actionability. Conclusions: The YouTube videos on hearing loss focus on a range of issues. The poor actionability of these videos was a concern as these videos may not lead to appropriate consumer actions in addressing their hearing loss. Efforts are needed to improve the quality and content of these videos to promote appropriate behavior change

Citation as a Critical Practice

This discussion will explore the politics and ethics of citation. As academics, how, why, when, and whom do we cite, and what is at stake in these practices? Areas for discussion will include representation in disciplinary canons and the undercitation of scholars who are Black, Indigenous, People of Color, LGBTQ+, women, and members of multiply marginalized groups. By considering citation in the context of power and privilege, this panel will unpack what it means to adopt a critical approach to citation in our research, teaching, and scholarship. Watch the video to see the discussion. Click on the download button for a list of readings and resources.https://digitalcommons.usu.edu/inter_inclusion/1000/thumbnail.jp

White Male Privilege: An Intersectional Deconstruction

This research saliently deconstructs the philosophical writing of a white, privileged male by five diverse academic peers by using a methodology of deconstruction to analyze the initial author\u27s writing. Their reflects on his nascent perspectives address the stages of racism, mea culpa, the relationship between privilege, oppression, and classism, a feminist perspective, binary, and intersectionality. Further analysis connote for the need to deconstruct privilege in a literary context and to develop an autoethnography to fully delve into privilege beyond a superficial and neglectful narrative

Xochicalco: la crisis ambiental y sociopolítica en un sitio del epiclásico mesoamericano

Cuando se hablaba del colapso de las sociedades pretéritas, generalmente se acudía a explicaciones unicausales de índole ambiental, como las sequías o las inundaciones. Sin embargo, desde hace unas décadas, las categorías y las hipótesis que buscan explicar y entender las razones y las formas en que sociedades bien establecidas abandonaron sus territorios se han replanteado. Actualmente, ya no hablamos de colapsos sino de transformaciones y, al mismo tiempo, buscamos no sólo las evidencias de los cambios climáticos en el pasado sino las formas en que las sociedades los enfrentaron, sus niveles de vulnerabilidad y los efectos que pudieron tener en su desarrollo histórico.Un ejemplo de los cambios paradigmáticos sobre este tema en la arqueología de Mesoamérica es el caso del antes llamado “colapso maya”. Hoy en día, las propias comunidades, los antropólogos y los arqueólogos han buscado desmitificar este concepto que refiere al abandono de las grandes ciudades ubicadas en un amplio territorio que cubre el sur y sureste de México, además de los países de Guatemala, Belice y Honduras. La presencia y persistencia de los diversos grupos mayas, cuyas costumbres milenarias han permanecido y buscan mantenerse son una muestra de que nunca existió tal colapso. Más bien, se plantean procesos de transformación, adaptación, resistencia y resiliencia, resultado de los procesos históricos sociales acrecentados en el momento de la invasión española. Si bien los factores no sólo climáticos, sino también aquellos fenómenos naturales como el vulcanismo, los sismos y huracanes, entre otros, son eventos que debieron impactar aquellas sociedades, no podemos establecer que éstos fueron la única causa de su transformación.En el presente artículo, exponemos el caso del sitio arqueológico de Xochicalco, ubicado en el altiplano central de México. Si bien este asentamiento fue fundado en una época en el que los datos paleoclimáticos apuntan a una reducción en la precipitación pluvial y una sequía, los datos arqueológicos revelan el establecimiento de una sociedad con un sistema de organización social consolidado que aseguraba la subsistencia de sus pobladores pese a las condiciones climáticas de la época. No obstante, pese a las distintas formas de buscar adaptarse y transformarse, la ciudad sufrió los efectos de condiciones climáticas desfavorables que impactó en un sistema social con fallas estructurales que, después de casi cuatro siglos de existencia, sería abandonada permanentemente

Mutations in the tryptophan operon allow PurF-independent thiamine synthesis by altering flux in vivo

Phosphoribosyl amine (PRA) is an intermediate in purine biosynthesis and also required for thiamine biosynthesis in Salmonella enterica. PRA is normally synthesized by phosphoribosyl pyrophosphate (PRPP) amidotransferase, a high-turnover enzyme of the purine biosynthetic pathway encoded by purF. However, PurF-independent PRA synthesis has been observed in strains with different genetic backgrounds and growing under diverse conditions. Genetic analysis has shown that the anthranilate synthase-phosphoribosyltransferase (AS-PRT) enzyme complex, involved in the synthesis of tryptophan, can play a role in the synthesis of phosphoribosyl amine (PRA). This work describes the in vitro synthesis of PRA in the presence of the purified components of AS-PRT complex. Results from in vitro assays and in vivo studies indicate the cellular accumulation of phosphoribosyl anthranilate can result in non-enzymatic PRA formation sufficient for thiamine synthesis. These studies have uncovered a mechanism used by cells to redistribute metabolites to ensure thiamine synthesis, and may define a general paradigm of metabolic robustness