Rural Latino High School Students Considering Identity and Belonging Through Comparative Study of Newcomer Youth in South Africa

Precipitated by an arranged but unusual classroom activity — eight Latina immigrant high school students in the rural u.s. Midwest interviewing a visiting South African scholar of immigration and transnationalism — this study captures their deliberations as the consideration of youth immigration to South Africa compels their own autobiographic reflections on who they are, where they are \u27of\u27, and with what ethnic groups or nationalities they feel affiliation or welcome. For purposes of bracketing, it also juxtaposes the students\u27 voices with those of the three coauthors: their classroom teacher of Spanish as a heritage language, the visiting scholar from South Africa, and a professor from the nearby university who is the teacher\u27s doctoral chair and was host of the South African scholar\u27s visit. Studenti di origine latino-americana di scuole superiori rurali considerano l\u27identità e l\u27appartenenza attraverso uno studio comparativo di giovani neoarrivati in Sud Africa Piombati in una organizzata quanto insolita attività scolastica — otto studenti immigrati di origine latino-americana di una scuola superiore nel Midwest rurale degli Stati Uniti che intervistano docenti di immigrazione e transnazionalismo provenienti dal Sud Africa in visit a — questo studio coglie le loro riflessioni: la considerazione dell\u27immigrazione giovanile in Sud Africa impone loro riflessioni autobiografiche su chi sono, da dove provengono, e con quali gruppi etnici 0 nazionalità si sentono affiliati o accolti. Ai fini della sospensione di giudizio, si giustappongono anche Ie voci degli studenti con quelle dei tre coautori: il loro insegnante di spagnolo, loro lingua d\u27origine, lo studioso in visita dal Sud Africa, e un professore della vicina università che è presidente del corso di dottorato ed è stato ospite della visita dello studioso sudafricano. Parole chiave: Giovani immigrati - Tramnazionalismo - Latinos – Scolarizzazione e identità - Giustizia sodale - Midwest degli Stati Uniti - Sud Afric

Selective Pressures to Maintain Attachment Site Specificity of Integrative and Conjugative Elements

Integrative and conjugative elements (ICEs) are widespread mobile genetic elements that are usually found integrated in bacterial chromosomes. They are important agents of evolution and contribute to the acquisition of new traits, including antibiotic resistances. ICEs can excise from the chromosome and transfer to recipients by conjugation. Many ICEs are site-specific in that they integrate preferentially into a primary attachment site in the bacterial genome. Site-specific ICEs can also integrate into secondary locations, particularly if the primary site is absent. However, little is known about the consequences of integration of ICEs into alternative attachment sites or what drives the apparent maintenance and prevalence of the many ICEs that use a single attachment site. Using ICEBs1, a site-specific ICE from Bacillus subtilis that integrates into a tRNA gene, we found that integration into secondary sites was detrimental to both ICEBs1 and the host cell. Excision of ICEBs1 from secondary sites was impaired either partially or completely, limiting the spread of ICEBs1. Furthermore, induction of ICEBs1 gene expression caused a substantial drop in proliferation and cell viability within three hours. This drop was dependent on rolling circle replication of ICEBs1 that was unable to excise from the chromosome. Together, these detrimental effects provide selective pressure against the survival and dissemination of ICEs that have integrated into alternative sites and may explain the maintenance of site-specific integration for many ICEs.United States. Public Health Service (Grant GM050895

A Novel Tetrameric PilZ Domain Structure from Xanthomonads

PilZ domain is one of the key receptors for the newly discovered secondary messenger molecule cyclic di-GMP (c-di-GMP). To date, several monomeric PilZ domain proteins have been identified. Some exhibit strong c-di-GMP binding activity, while others have barely detectable c-di-GMP binding activity and require an accessory protein such as FimX to indirectly respond to the c-di-GMP signal. We now report a novel tetrameric PilZ domain structure of XCC6012 from the plant pathogen Xanthomonas campestris pv. campestris (Xcc). It is one of the four PilZ domain proteins essential for Xcc pathogenicity. Although the monomer adopts a structure similar to those of the PilZ domains with very weak c-di-GMP binding activity, it is nevertheless interrupted in the middle by two extra long helices. Four XCC6012 proteins are thus self-assembled into a tetramer via the extra heptad repeat α3 helices to form a parallel four-stranded coiled-coil, which is further enclosed by two sets of inclined α2 and α4 helices. We further generated a series of XCC6012 variants and measured the unfolding temperatures and oligomeric states in order to investigate the nature of this novel tetramer. Discovery of this new PilZ domain architecture increases the complexity of c-di-GMP-mediated regulation

Rural Latino High School Students Considering Identity and Belonging Through Comparative Study of Newcomer Youth in South Africa

Precipitated by an arranged but unusual classroom activity — eight Latina immigrant high school students in the rural u.s. Midwest interviewing a visiting South African scholar of immigration and transnationalism — this study captures their deliberations as the consideration of youth immigration to South Africa compels their own autobiographic reflections on who they are, where they are \u27of\u27, and with what ethnic groups or nationalities they feel affiliation or welcome. For purposes of bracketing, it also juxtaposes the students\u27 voices with those of the three coauthors: their classroom teacher of Spanish as a heritage language, the visiting scholar from South Africa, and a professor from the nearby university who is the teacher\u27s doctoral chair and was host of the South African scholar\u27s visit. Studenti di origine latino-americana di scuole superiori rurali considerano l\u27identità e l\u27appartenenza attraverso uno studio comparativo di giovani neoarrivati in Sud Africa Piombati in una organizzata quanto insolita attività scolastica — otto studenti immigrati di origine latino-americana di una scuola superiore nel Midwest rurale degli Stati Uniti che intervistano docenti di immigrazione e transnazionalismo provenienti dal Sud Africa in visit a — questo studio coglie le loro riflessioni: la considerazione dell\u27immigrazione giovanile in Sud Africa impone loro riflessioni autobiografiche su chi sono, da dove provengono, e con quali gruppi etnici 0 nazionalità si sentono affiliati o accolti. Ai fini della sospensione di giudizio, si giustappongono anche Ie voci degli studenti con quelle dei tre coautori: il loro insegnante di spagnolo, loro lingua d\u27origine, lo studioso in visita dal Sud Africa, e un professore della vicina università che è presidente del corso di dottorato ed è stato ospite della visita dello studioso sudafricano. Parole chiave: Giovani immigrati - Tramnazionalismo - Latinos – Scolarizzazione e identità - Giustizia sodale - Midwest degli Stati Uniti - Sud Afric

In search of best practice in South African desegregated schools

One of the daunting challenges facing South Africa in the contemporary period is that of achieving social cohesion. Educational institutions should be at the cutting edge of the project to weave a common identity whilst promoting respect for difference. It was this challenge that motivated us to convene colloquia in 2003 and 2006 to discuss the current state of school desegregation and innovative ways to forge ahead in the complex processes of dismantling the legacies of the past and creating inclusive paradigms for our classrooms. This monograph represents an attempt to record what could be regarded as nascent events in a few schools that have the potential to grow into models of best practice in managing diversity. These fledgling efforts always coexist with powerful contrary traditions that may retard their fruition, and to witness their growth in slow motion is both enlightening and instructive. A small survey of stakeholders' perceptions about what constitutes 'best practice' in a desegregated school environment, supported by classroom observation, interviews and focus groups form the basis for this analysis of emergent patterns in the practices which foster healthy identities in our learners, both as individuals and as members of South African society. Concise and written in an accessible style, the study is important reading for educationists at every level, policymakers and all involved in teacher education.

Site-directed mutagenesis on plasmid using polymerase chain reaction

Site-directed mutagenesis (SDM) is a very useful technique to study changes in protein function that may occur as a result of the DNA manipulation. A detail procedure to employ SDM on whole plasmid using polymerase chain reaction (PCR) with successful application of the method on a pET28a plasmid harboring an endoglucanase I gene from Fusarium oxysporum is described here