Biophysical characterization of the outer membrane polysaccharide export protein and the polysaccharide co-polymerase protein from Xanthomonas campestris

This study investigated the structural and biophysical characteristics of GumB and GumC, two Xanthomonas campestris membrane proteins that are involved in xanthan biosynthesis. Xanthan is an exopolysaccharide that is thought to be a virulence factor that contributes to bacterial in planta growth. It also is one of the most important industrial biopolymers. The first steps of xanthan biosynthesis are well understood, but the polymerization and export mechanisms remain unclear. For this reason, the key proteins must be characterized to better understand these processes. Here we characterized, by biochemical and biophysical techniques, GumB, the outer membrane polysaccharide export protein, and GumC, the polysaccharide co-polymerase protein of the xanthan biosynthesis system. Our results suggested that recombinant GumB is a tetrameric protein in solution. On the other hand, we observed that both native and recombinant GumC present oligomeric conformation consistent with dimers and higher-order oligomers. The transmembrane segments of GumC are required for GumC expression and/or stability. These initial results provide a starting point for additional studies that will clarify the roles of GumB and GumC in the xanthan polymerization and export processes and further elucidate their functions and mechanisms of action.Fil: Bianco, María Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Jacobs, Melisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Salinas, Silvina Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Salvay, Andrés Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física de Líquidos y Sistemas Biológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física de Líquidos y Sistemas Biológicos; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Ielmini, M. V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Ielpi, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Biophysical characterization of the outer membrane polysaccharide export protein and the polysaccharide co-polymerase protein from <i>Xanthomonas campestris</i>

This study investigated the structural and biophysical characteristics of GumB and GumC, two Xanthomonas campestris membrane proteins that are involved in xanthan biosynthesis. Xanthan is an exopolysaccharide that is thought to be a virulence factor that contributes to bacterial in planta growth. It also is one of the most important industrial biopolymers. The first steps of xanthan biosynthesis are well understood, but the polymerization and export mechanisms remain unclear. For this reason, the key proteins must be characterized to better understand these processes. Here we characterized, by biochemical and biophysical techniques, GumB, the outer membrane polysaccharide export protein, and GumC, the polysaccharide co-polymerase protein of the xanthan biosynthesis system. Our results suggested that recombinant GumB is a tetrameric protein in solution. On the other hand, we observed that both native and recombinant GumC present oligomeric conformation consistent with dimers and higher-order oligomers. The transmembrane segments of GumC are required for GumC expression and/or stability. These initial results provide a starting point for additional studies that will clarify the roles of GumB and GumC in the xanthan polymerization and export processes and further elucidate their functions and mechanisms of action.Instituto de Física de Líquidos y Sistemas Biológico

Never Deaf of Learning with Heart: Understanding the Essence of Handling Pupils with Hearing Impairment

This transcendental phenomenology study aimed at describing and understanding the lived experience of eight (8) Special education teachers handling learners with hearing impairment.Specifically, they were private school teachers in the cities of Biñan, Sta. Rosa and San Pedro Laguna, Philippines who were purposively selected using inclusion criteria. Framed with the approach of Moustakas (1994) as cited by Creswell (2007), the researchers carefully analyzed the participants’ verbatim accounts which resulted in six (6) themes categorized into textural and structural descriptions. Collectively taken, the essence of the study highlighted the participants’ experience in handling hearing-impaired learners which covered engaging them in different activities (Theme 1), customized communication with them (Theme 2), and love and drive to reach out to these individuals (Theme 3). They coped with the challenges they face by clinging to the vital role of assessment tools (Theme 4), highlighting values in teaching (Theme 5) and viewing their profession as a calling of commitment and devotion (Theme 6). The lived experiences of special education teachers with learners diagnosed with hearing impairment may serve as a feedback for special education instructional materials suppliers or developers in improving the contents of their works to better cater the needs of special education teachers in terms of the choice of innovated instructional materials that specifically address the learning needs of students in special education

Innovative Ventures for Student Mobility of the Americas

The project “Innovative Ventures for student mobility in the Americas” was generally aim to generate a channel for the exchange of students at West Virginia University (WVU) United States and the National University of Asunción (UNA) of Paraguay. the methodology used in the screening process was through a public tender, using psychometric tests, individual interviews and an essay about the interests of students. the main results obtained were the mobility of students, research in the area environmental, international experience, cultural learning, knowledge about environmental and energy scenarios for the US and Paraguay and interaction of student groups and community institutions. It is concluded based on the reports of students and assessment coordinators from both universities that experience helped broaden the vision of future professionals and to target in the medium term; perform master’s degrees and specializations in universities abroad. It is recommended that the A further promote exchange innovative projects aimed at international accreditation so as to establish the exchange of undergraduate and graduate for the benefit of the university and the country

Perspectives and advantages of the use of excimer laser annealing for MOS technology

The integration of excimer laser annealing (ELA) into the MOS device technology has been studied and evaluated within the frame of the IST project FLASH (Fundamentals and applications of laser processing for highly innovative MOS technology), funded by the European Commission. The final aim of the project was to demonstrate that ELA can be applied as a reliable, effective and advantageous process in the context of semiconductor device fabrication. Some of the results of this activity are summarised, relative to the experimental characterization and theoretical modelling. The electrical characterization of the transistor fabricated by ELA is also presented, showing a device yield of 90% on wafer

Genomic epidemiology of the primary methicillin-resistant Staphylococcus aureus clones causing invasive infections in Paraguayan children

Address correspondence to Fátima Rodríguez, [email protected] Staphylococcus aureus (MRSA) is one of the major human pathogens. It could carry numerous resistance genes and virulence factors in its genome, some of which are related to the severity of the infection. An observational, descriptive, cross-sectional study was designed to molecularly analyze MRSA isolates that cause invasive infections in Paraguayan children from 2009 to 2013. Ten representative MRSA isolates of the main clonal complex identified were analyzed with short-read paired-end sequencing and assessed for the virulome, resistome, and phylogenetic relationships. All the genetically linked MRSA isolates were recovered from diverse clinical sources, patients, and hospitals at broad gap periods. The pan-genomic analysis of these clones revealed three major and different clonal complexes (CC30, CC5, and CC8), each composed of clones closely related to each other. The CC30 genomes prove to be a successful clone, strongly installed and disseminated throughout our country, and closely related to other CC30 public genomes from the region and the world. The CC5 shows the highest genetic variability, and the CC8 carried the complete arginine catabolic mobile element (ACME), closely related to the USA300-NAE-ACME+, identified as the major cause of CA-MRSA infections in North America. Multiple virulence and resistance genes were identified for the first time in this study, highlighting the complex virulence profiles of MRSA circulating in the country. This study opens a wide range of new possibilities for future projects and trials to improve the existing knowledge on the epidemiology of MRSA circulating in Paraguay.Consejo Nacional de Ciencia y TecnologíaPrograma Paraguayo para el Desarrollo de la Ciencia y Tecnología. Financiamiento para la vinculación de científicos y tecnólogo

Impact of global PTP1B deficiency on the gut barrier permeability during NASH in mice.

OBJECTIVE:Non-alcoholic steatohepatitis (NASH) is characterized by a robust pro-inflammatory component at both hepatic and systemic levels together with a disease-specific gut microbiome signature. Protein tyrosine phosphatase 1 B (PTP1B) plays distinct roles in non-immune and immune cells, in the latter inhibiting pro-inflammatory signaling cascades. In this study, we have explored the role of PTP1B in the composition of gut microbiota and gut barrier dynamics in methionine and choline-deficient (MCD) diet-induced NASH in mice. METHODS:Gut features and barrier permeability were characterized in wild-type (PTP1B WT) and PTP1B-deficient knockout (PTP1B KO) mice fed a chow or methionine/choline-deficient (MCD) diet for 4 weeks. The impact of inflammation was studied in intestinal epithelial and enteroendocrine cells. The secretion of GLP-1 was evaluated in primary colonic cultures and plasma of mice. RESULTS:We found that a shift in the gut microbiota shape, disruption of gut barrier function, higher levels of serum bile acids, and decreased circulating glucagon-like peptide (GLP)-1 are features during NASH. Surprisingly, despite the pro-inflammatory phenotype of global PTP1B-deficient mice, they were partly protected against the alterations in gut microbiota composition during NASH and presented better gut barrier integrity and less permeability under this pathological condition. These effects concurred with higher colonic mucosal inflammation, decreased serum bile acids, and protection against the decrease in circulating GLP-1 levels during NASH compared with their WT counterparts together with increased expression of GLP-2-sensitive genes in the gut. At the molecular level, stimulation of enteroendocrine STC-1 cells with a pro-inflammatory conditioned medium (CM) from lipopolysaccharide (LPS)-stimulated macrophages triggered pro-inflammatory signaling cascades that were further exacerbated by a PTP1B inhibitor. Likewise, the pro-inflammatory CM induced GLP-1 secretion in primary colonic cultures, an effect augmented by PTP1B inhibition. CONCLUSION:Altogether our results have unraveled a potential role of PTP1B in the gut-liver axis during NASH, likely mediated by increased sensitivity to GLPs, with potential therapeutic value

Community perspective of the fishing activity in El Arenal, Acapulco, Mexico

For many communities settled on the coastline of coastal lagoons, fishing is an important activity because of the income it generates from the work they perform. Objective: To analyze the community perspective of the fishing activity in the community of El Arenal. Methodology: The research is a mixed case study and its development consisted in seven stages, which were: description of the area where field immersion was carried out and identification of socioenvironmental problems, informal dialogue with the fishermen, information processing, data analysis through descriptive statistics, and deductive analysis of the discourse. Results: Overfishing is evident, and the breach of closed season and high levels of capture in live weight which was 1275 t in 2022. The 37 cooperatives do not have trade channels and brokers are in charge of trading the product. At the socioenvironmental level, the community of El Arenal does not have residue collection programs or for lagoon or mangrove care. Conclusions: The production model based on overfishing exhausts the natural resource because there is no planning for the fishing resource and it does not respect the closed season law, resulting in socioenvironmental problems for the community, overfishing, contamination of the lagoon, and social marginalization

Lower IgG somatic hypermutation rates during acute dengue virus infection is compatible with a germinal center-independent B cell response

Reads, clonal groups, and lineages numbers per individual and condition. The table shows the number of raw and used sequences as well as the number of clonotypes and lineages per individual. (XLS 30 kb

Parental Burnout Assessment (PBA) in Different Hispanic Countries: An Exploratory Structural Equation Modeling Approach

Parental burnout is a unique and context-specific syndrome resulting from a chronic imbalance of risks over resources in the parenting domain. The current research aims to evaluate the psychometric properties of the Spanish version of the Parental Burnout Assessment (PBA) across Spanish-speaking countries with two consecutive studies. In Study 1, we analyzed the data through a bifactor model within an Exploratory Structural Equation Modeling (ESEM) on the pooled sample of participants (N = 1,979) obtaining good fit indices. We then attained measurement invariance across both gender and countries in a set of nested models with gradually increasing parameter constraints. Latent means comparisons across countries showed that among the participants' countries, Chile had the highest parental burnout score, likewise, comparisons across gender evidenced that mothers displayed higher scores than fathers, as shown in previous studies. Reliability coefficients were high. In Study 2 (N = 1,171), we tested the relations between parental burnout and three specific consequences, i.e., escape and suicidal ideations, parental neglect, and parental violence toward one's children. The medium to large associations found provided support for the PBA's predictive validity. Overall, we concluded that the Spanish version of the PBA has good psychometric properties. The results support its relevance for the assessment of parental burnout among Spanish-speaking parents, offering new opportunities for cross-cultural research in the parenting domain