Utility of Pop-Up Satellite Archival Tags to Study the Summer Dispersal and Habitat Occupancy of Dolly Varden in Arctic Alaska

In Arctic Alaska, Dolly Varden Salvelinus malma is highly valued as a subsistence fish; however, little is known about its marine ecology. New advances in electronic tagging, such as pop-up satellite archival tags (PSATs), provide scientists with a fishery-independent means of studying several aspects of this species’ movement and ecology. To evaluate the usefulness of this technology, we attached 52 PSATs to Dolly Varden in the Wulik River, which flows from northwestern Alaska into the Chukchi Sea, to study several characteristics of the marine habits of this species. Overall, PSATs provided unprecedented information about summer dispersal of Dolly Varden, including the first evidence of offshore dispersal in the Chukchi Sea, as well as previously documented dispersal types such as movement to other rivers and southerly nearshore movements in northwestern Alaska. On the basis of minimal observable evidence of tag-induced behavioral effects, as well as movements of more than 450 km by fish at liberty (i.e., between tag deployment and release or recapture), we conclude that PSATs offer an effective alternative method for studying several aspects of Dolly Varden dispersal and ecology in areas where it is not practical or feasible to capture these fish, such as coastal and offshore regions of Arctic AlaskaDans l’Alaska de l’Arctique, l’omble du Pacifique, Salvelinus malma revêt une grande importance en tant que poisson de subsistance. Toutefois, on en sait peu sur son écologie marine. Les progrès réalisés en matière de traçabilité électronique, notamment en ce qui a trait aux étiquettes de collecte de données par satellite (PSAT) permettent aux scientifiques d’étudier plusieurs aspects des déplacements et de l’écologie de cette espèce sans dépendre de la pêche. Afin d’évaluer l’utilité de cette technologie, nous avons fixé 52 PSAT à des ombles du Pacifique de la rivière Wulik, qui s’écoule depuis le nord-ouest de l’Alaska jusqu’à la mer des Tchouktches, pour étudier plusieurs caractéristiques des habitudes aquatiques de cette espèce. Dans l’ensemble, les PSAT ont permis de recueillir des renseignements sans précédent au sujet de la dispersion estivale de l’omble du Pacifique, y compris la première preuve de dispersion extracôtière dans la mer des Tchouktches et d’autres types de dispersion anciennement documentés, comme les déplacements vers d’autres cours d’eau et les déplacements sublittoraux en direction sud, dans le nord-ouest de l’Alaska. D’après un minimum d’éléments de preuve observables quant aux effets découlant de la présence d’étiquettes sur le comportement ainsi que d’après les déplacements de plus de 450 kilomètres des poissons en liberté (c’est-à-dire entre l’installation des étiquettes et le relâchement ou la recapture), nous concluons que les PSAT présentent une méthode de rechange efficace pour étudier plusieurs aspects de la dispersion et de l’écologie de l’omble du Pacifique dans des endroits où il n’est pas pratique ou réalisable de prendre ces poissons, comme dans les régions côtières et extracôtières de l’Alaska de l’Arctique

Area-level incarceration and STI risk among a cohort of justice-involved adolescents and adults

Background: Living in areas of high incarceration is associated with increased risk of STI; however, STI risk with respect to both this area-level exposure and an individual’s involvement with the justice system is not known. Objective: Among individuals before and after arrest or incarceration, assess the association between area-level incarceration rates and risk of chlamydia, gonorrhea, or syphilis. Methods: Retrospective cohort study of individuals living in Marion County (Indianapolis), Indiana who were arrested or in jail, prison, juvenile detention, or juvenile prison between 2005-2008 (N=97,765). Area-level incarceration exposure was defined by the proportion of person-days incarcerated among the total population*365 within a census block group. A 1-year period was assessed before and after a randomly-selected arrest/incarceration per person. Multivariable logistic regression, controlling for age, race, STI history, and year, was performed to assess chlamydia, gonorrhea, or syphilis risk by quartile area-level incarceration exposure, adjusting for individual clustering and stratifying by gender. Results: Area-level incarceration was associated with increased odds of each STI, with a dose response relationship particularly among those with an arrest or jail stay. Women with a history of arrest or jail/prison stay and living in high incarceration areas had higher odds of STI, compared to men with comparable incarceration history and living in similar areas

Test positivity for chlamydia, gonorrhea, and syphilis infection among a cohort of individuals released from jail in Marion County, Indiana

BACKGROUND: Individuals entering jails have high rates of sexually transmitted infections (STI), but there are few data on STI in the postincarceration period. This study aimed to describe rates of chlamydia, gonorrhea, and syphilis infection among individuals released from Marion County (Indianapolis), Indiana jails. METHODS: We conducted a retrospective cohort study of individuals incarcerated in Marion County, Indiana jails from 2003 to 2008 (n = 118,670). We linked county jail and public health data to identify individuals with positive STI test results in the 1 year after release from jail. Rates per 100,000 individuals and Cox proportional hazard analyses were performed for each STI, stratified by demographic, STI, and jail characteristics. RESULTS: We found significantly higher rates of STI in this cohort than in the general population, with rates in the 1 year after release being 2 to 7 times higher for chlamydia, 5 to 24 times higher for gonorrhea, and 19 to 32 times higher for syphilis compared with rates in the general population. Characteristics most associated with increased risk of a positive STI test result among this cohort were younger age for chlamydia and gonorrhea, older age for syphilis, black race for men, being jailed for prostitution for women, history of STI, and history of prior incarceration. CONCLUSIONS: This study found high rates of STIs among a cohort of individuals recently released from jail and identified a number of risk factors. Further study is needed to improve targeted STI testing and treatment among this high-risk population

Characteristics of HIV-infected adolescents enrolled in a disclosure intervention trial in western Kenya

Knowledge of one's own HIV status is essential for long-term disease management, but there are few data on how disclosure of HIV status to infected children and adolescents in sub-Saharan Africa is associated with clinical and psychosocial health outcomes. We conducted a detailed baseline assessment of the disclosure status, medication adherence, HIV stigma, depression, emotional and behavioral difficulties, and quality of life among a cohort of Kenyan children enrolled in an intervention study to promote disclosure of HIV status. Among 285 caregiver-child dyads enrolled in the study, children's mean age was 12.3 years. Caregivers were more likely to report that the child knew his/her diagnosis (41%) compared to self-reported disclosure by children (31%). Caregivers of disclosed children reported significantly more positive views about disclosure compared to caregivers of non-disclosed children, who expressed fears of disclosure related to the child being too young to understand (75%), potential psychological trauma for the child (64%), and stigma and discrimination if the child told others (56%). Overall, the vast majority of children scored within normal ranges on screenings for behavioral and emotional difficulties, depression, and quality of life, and did not differ by whether or not the child knew his/her HIV status. A number of factors were associated with a child's knowledge of his/her HIV diagnosis in multivariate regression, including older age (OR 1.8, 95% CI 1.5-2.1), better WHO disease stage (OR 2.5, 95% CI 1.4-4.4), and fewer reported caregiver-level adherence barriers (OR 1.9, 95% CI 1.1-3.4). While a minority of children in this cohort knew their HIV status and caregivers reported significant barriers to disclosure including fears about negative emotional impacts, we found that disclosure was not associated with worse psychosocial outcomes

Pharmacokinetics-based adherence measures for antiretroviral therapy in HIV-infected Kenyan children

BACKGROUND: Traditional medication adherence measures do not account for the pharmacokinetic (PK) properties of the drugs, potentially misrepresenting true therapeutic exposure. METHODS: In a population of HIV-infected Kenyan children on antiretroviral therapy including nevirapine (NVP), we used a one-compartment model with previously established PK parameters and Medication Event Monitoring Systems (MEMS®)-recorded dosing times to estimate the mean plasma concentration of NVP (Cp) in individual patients during 1 month of follow-up. Intended NVP concentration (Cp') was calculated under a perfectly followed dosing regimen and frequency. The ratio between the two (R = Cp/Cp') characterized the patient's NVP exposure as compared to intended level. Smaller R values indicated poorer adherence. We validated R by evaluating its association with MEMS®-defined adherence, CD4%, and spot-check NVP plasma concentrations assessed at 1 month. RESULTS: In data from 152 children (82 female), children were mean age 7.7 years (range 1.5-14.9) and on NVP an average of 2.2 years. Mean MEMS® adherence was 79%. The mean value of R was 1.11 (SD 0.37). R was positively associated with MEMS® adherence (p < 0.0001), and lower-than-median R values were significantly associated with lower NVP drug concentrations (p = 0.0018) and lower CD4% (p = 0.0178), confirming a smaller R value showed poorer adherence. CONCLUSION: The proposed adherence measures, R, captured patient drug-taking behaviours and PK properties

HIV Stigma: Perspectives from Kenyan Child Caregivers and Adolescents Living with HIV

Stigma shapes all aspects of HIV prevention and treatment, yet there are limited data on how HIV-infected youth and their families are affected by stigma in sub-Saharan Africa. The authors conducted a qualitative study using focus group discussions among 39 HIV-infected adolescents receiving care at HIV clinics in western Kenya and 53 caregivers of HIV-infected children. Participants felt that while knowledge and access to treatment were increasing, many community members still held negative and inaccurate views about HIV, including associating it with immorality and believing in transmission by casual interactions. Stigma was closely related to a loss of social and economic support but also included internalized negative feelings about oneself. Participants identified treatment-related impacts of stigma, including nonadherence, nondisclosure of status to child or others, and increased mental health problems. Qualitative inquiry also provided insights into how to measure and reduce stigma among affected individuals and families

Regulation of Small RNA Accumulation in the Maize Shoot Apex

MicroRNAs (miRNAs) and trans-acting siRNAs (ta-siRNAs) are essential to the establishment of adaxial–abaxial (dorsoventral) leaf polarity. Tas3-derived ta-siRNAs define the adaxial side of the leaf by restricting the expression domain of miRNA miR166, which in turn demarcates the abaxial side of leaves by restricting the expression of adaxial determinants. To investigate the regulatory mechanisms that allow for the precise spatiotemporal accumulation of these polarizing small RNAs, we used laser-microdissection coupled to RT-PCR to determine the expression profiles of their precursor transcripts within the maize shoot apex. Our data reveal that the pattern of mature miR166 accumulation results, in part, from intricate transcriptional regulation of its precursor loci and that only a subset of mir166 family members contribute to the establishment of leaf polarity. We show that miR390, an upstream determinant in leaf polarity whose activity triggers tas3 ta-siRNA biogenesis, accumulates adaxially in leaves. The polar expression of miR390 is established and maintained independent of the ta-siRNA pathway. The comparison of small RNA localization data with the expression profiles of precursor transcripts suggests that miR166 and miR390 accumulation is also regulated at the level of biogenesis and/or stability. Furthermore, mir390 precursors accumulate exclusively within the epidermal layer of the incipient leaf, whereas mature miR390 accumulates in sub-epidermal layers as well. Regulation of miR390 biogenesis, stability, or even discrete trafficking of miR390 from the epidermis to underlying cell layers provide possible mechanisms that define the extent of miR390 accumulation within the incipient leaf, which patterns this small field of cells into adaxial and abaxial domains via the production of tas3-derived ta-siRNAs

Comprehensive evaluation of caregiver-reported antiretroviral therapy adherence for HIV-infected children

For HIV-infected children, adherence to antiretroviral therapy (ART) is often assessed by caregiver report but there are few data on their validity. We conducted prospective evaluations with 191 children ages 0-14 years and their caregivers over 6 months in western Kenya to identify questionnaire items that best predicted adherence to ART. Medication Event Monitoring Systems(®) (MEMS, MWV/AARDEX Ltd., Switzerland) electronic dose monitors were used as external criterion for adherence. We employed a novel variable selection tool using the LASSO technique with logistic regression to identify items best correlated with dichotomized MEMS adherence (≥90 or <90 % doses taken). Nine of 48 adherence items were identified as the best predictors of adherence, including missed or late doses in the past 7 days, problems giving the child medicines, and caregiver-level factors like not being present at medication taking. These items could be included in adherence assessment tools for pediatric patients

Intragenic Meiotic Crossovers Generate Novel Alleles with Transgressive Expression Levels

Meiotic recombination is an evolutionary force that generates new genetic diversity upon which selection can act. Whereas multiple studies have assessed genome-wide patterns of recombination and specific cases of intragenic recombination, few studies have assessed intragenic recombination genome-wide in higher eukaryotes. We identified recombination events within or near genes in a population of maize recombinant inbred lines (RILs) using RNA-sequencing data. Our results are consistent with case studies that have shown that intragenic crossovers cluster at the 5\u27 ends of some genes. Further, we identified cases of intragenic crossovers that generate transgressive transcript accumulation patterns, that is, recombinant alleles displayed higher or lower levels of expression than did nonrecombinant alleles in any of ~100 RILs, implicating intragenic recombination in the generation of new variants upon which selection can act. Thousands of apparent gene conversion events were identified, allowing us to estimate the genome-wide rate of gene conversion at SNP sites (4.9 X 10-5). The density of syntenic genes (i.e., those conserved at the same genomic locations since the divergence of maize and sorghum) exhibits a substantial correlation with crossover frequency, whereas the density of nonsyntenic genes (i.e., those which have transposed or been lost subsequent to the divergence of maize and sorghum) shows little correlation, suggesting that crossovers occur at higher rates in syntenic genes than in nonsyntenic genes. Increased rates of crossovers in syntenic genes could be either a consequence of the evolutionary conservation of synteny or a biological process that helps to maintain synteny