Variable Swarm Research Articles

Spanish in the Southeast: What a Swarm of Variables Can Tell Us about a Newly Forming Bilingual Community

The southeastern United States has experienced rapid growth in the Hispanic population in recent decades, giving rise to a newly forming bilingual community. The present study builds on previous work by the authors via expansion of a “variable swarm”: the analysis of multiple linguistic variables simultaneously for the same set of speakers, with the goal of understanding patterns of accommodation and change within the community. The initial study included four linguistic variables (prosodic rhythm, bilingual discourse markers, the realization of /bdg/ and vowel space), and the present study adds an additional four variables (bilingual filled pauses, subject pronoun realization, code switching, and the labiodental realization of orthographic <v>) for 23 speakers of Mexican and Central American origin across two sociolinguistic generations (G1 vs. G2). Results for individual speakers show a pattern of adoption of some features by speakers of both generations (such as English-influenced prosodic rhythm and phonological filled pauses), while other, possibly more salient forms directly integrated from English (English discourse markers and code switching) exhibit later, highly variable rates of adoption, suggesting that speakers may consciously manipulate these variables as part of a process of active identity construction. Likewise, G1 speakers show fewer correlations among linguistic variables than G2 speakers, and patterns reveal that some bilingual forms are incorporated in tandem due to shared phonological traits or discourse functions. The innovative swarm analysis further contributes to the advancement of techniques employed in sociolinguistic research by serving as a bridge between traditional first- and second-wave studies that focus on a single variable, and third-wave studies that focus more on variation at the individual level.

HIV population genotypic tropism testing and its clinical significance

HIV co-receptor tropism testing is recommended before therapy when the C-C chemokine receptor type 5 antagonist maraviroc is initiated. This review addresses the use of population genotypic tropism testing in relation to clinical practice. Genotypic tropism tests predict viral co-receptor tropism based on the sequence of the V3 loop of the viral envelope. HIV occurs in a swarm of variants in the patient's body, called quasispecies. As next-generation sequencing techniques are not generally accessible to date, triplicate testing is often performed to improve sensitivity of population-based approaches, but no prospective studies assessing the performance of single and triplicate procedures related to clinical outcome have been performed yet. For interpretation of the genotype several web-based algorithms have been developed. Varying the cut-off of the commonly used geno2pheno[co-receptor] algorithm changes the sensitivity and specificity of the tropism prediction. In retrospective analyses of clinical studies and cohorts genotypic population tropism testing demonstrated equal correlation with clinical outcome on maraviroc compared with phenotypic assays.In patients with suppressed viraemia, proviral DNA testing is a well tolerated alternative to HIV-RNA testing. Population genotypic methods have greater accessibility, lower cost, and faster turnaround time than other methods. Despite limited sensitivity for minority variants HIV genotypic population tropism testing showed good correlation with clinical outcome.