Innovative recruitment using online networks: lessons learned from an online study of alcohol and other drug use utilizing a web-based, respondent-driven sampling (webRDS) strategy.

PubMed

Bauermeister, José A; Zimmerman, Marc A; Johns, Michelle M; Glowacki, Pietreck; Stoddard, Sarah; Volz, Erik

2012-09-01

We used a web version of Respondent-Driven Sampling (webRDS) to recruit a sample of young adults (ages 18-24) and examined whether this strategy would result in alcohol and other drug (AOD) prevalence estimates comparable to national estimates (National Survey on Drug Use and Health [NSDUH]). We recruited 22 initial participants (seeds) via Facebook to complete a web survey examining AOD risk correlates. Sequential, incentivized recruitment continued until our desired sample size was achieved. After correcting for webRDS clustering effects, we contrasted our AOD prevalence estimates (past 30 days) to NSDUH estimates by comparing the 95% confidence intervals of prevalence estimates. We found comparable AOD prevalence estimates between our sample and NSDUH for the past 30 days for alcohol, marijuana, cocaine, Ecstasy (3,4-methylenedioxymethamphetamine, or MDMA), and hallucinogens. Cigarette use was lower than NSDUH estimates. WebRDS may be a suitable strategy to recruit young adults online. We discuss the unique strengths and challenges that may be encountered by public health researchers using webRDS methods.

Towards the estimation of effect measures in studies using respondent-driven sampling.

PubMed

Rotondi, Michael A

2014-06-01

Respondent-driven sampling (RDS) is an increasingly common sampling technique to recruit hidden populations. Statistical methods for RDS are not straightforward due to the correlation between individual outcomes and subject weighting; thus, analyses are typically limited to estimation of population proportions. This manuscript applies the method of variance estimates recovery (MOVER) to construct confidence intervals for effect measures such as risk difference (difference of proportions) or relative risk in studies using RDS. To illustrate the approach, MOVER is used to construct confidence intervals for differences in the prevalence of demographic characteristics between an RDS study and convenience study of injection drug users. MOVER is then applied to obtain a confidence interval for the relative risk between education levels and HIV seropositivity and current infection with syphilis, respectively. This approach provides a simple method to construct confidence intervals for effect measures in RDS studies. Since it only relies on a proportion and appropriate confidence limits, it can also be applied to previously published manuscripts.

A Web 2.0 and Epidemiology Mash-Up: Using Respondent-Driven Sampling in Combination with Social Network Site Recruitment to Reach Young Transwomen.

PubMed

Arayasirikul, Sean; Chen, Yea-Hung; Jin, Harry; Wilson, Erin

2016-06-01

Respondent-driven sampling (RDS) peer referral has been proven to be an effective recruitment method for hard-to-reach populations; however, its application in diverse populations is limited. Recruitment occurred in two phases: RDS-only followed by development and implementation of an online social network strategy in combination with RDS peer referral (RDS + SNS). Compared to RDS-only, RDS + SNS reached a sample that was younger (χ(2) = 9.19, P = .03), more likely to identify with a non-binary gender identity (χ(2) = 10.4247, P = .03), with less housing instability (50.5 vs. 68.6 %, χ(2) = 9.0038, P = .002) and less sex work (19.7 vs. 31.4 %, χ(2) = 5.0798, P = .02). Additionally, we describe lessons learned as a result of implementing our online social network strategy. Our findings underscore the importance of integrating Internet-driven strategies to meet challenges in sample diversity and recruitment of young transwomen.

Challenges to Recruiting Population Representative Samples of Female Sex Workers in China Using Respondent Driven Sampling1

PubMed Central

Merli, M. Giovanna; Moody, James; Smith, Jeffrey; Li, Jing; Weir, Sharon; Chen, Xiangsheng

2014-01-01

We explore the network coverage of a sample of female sex workers (FSWs) in China recruited through Respondent Drive Sampling (RDS) as part of an effort to evaluate the claim of RDS of population representation with empirical data. We take advantage of unique information on the social networks of FSWs obtained from two overlapping studies --RDS and a venue-based sampling approach (PLACE) -- and use an exponential random graph modeling (ERGM) framework from local networks to construct a likely network from which our observed RDS sample is drawn. We then run recruitment chains over this simulated network to assess the assumption that the RDS chain referral process samples participants in proportion to their degree and the extent to which RDS satisfactorily covers certain parts of the network. We find evidence that, contrary to assumptions, RDS oversamples low degree nodes and geographically central areas of the network. Unlike previous evaluations of RDS which have explored the performance of RDS sampling chains on a non-hidden population, or the performance of simulated chains over previously mapped realistic social networks, our study provides a robust, empirically grounded evaluation of the performance of RDS chains on a real-world hidden population. PMID:24834869

Innovative Recruitment Using Online Networks: Lessons Learned From an Online Study of Alcohol and Other Drug Use Utilizing a Web-Based, Respondent-Driven Sampling (webRDS) Strategy

PubMed Central

Bauermeister, José A.; Zimmerman, Marc A.; Johns, Michelle M.; Glowacki, Pietreck; Stoddard, Sarah; Volz, Erik

2012-01-01

Objective: We used a web version of Respondent-Driven Sampling (webRDS) to recruit a sample of young adults (ages 18–24) and examined whether this strategy would result in alcohol and other drug (AOD) prevalence estimates comparable to national estimates (National Survey on Drug Use and Health [NSDUH]). Method: We recruited 22 initial participants (seeds) via Facebook to complete a web survey examining AOD risk correlates. Sequential, incentivized recruitment continued until our desired sample size was achieved. After correcting for webRDS clustering effects, we contrasted our AOD prevalence estimates (past 30 days) to NSDUH estimates by comparing the 95% confidence intervals of prevalence estimates. Results: We found comparable AOD prevalence estimates between our sample and NSDUH for the past 30 days for alcohol, marijuana, cocaine, Ecstasy (3,4-methylenedioxymethamphetamine, or MDMA), and hallucinogens. Cigarette use was lower than NSDUH estimates. Conclusions: WebRDS may be a suitable strategy to recruit young adults online. We discuss the unique strengths and challenges that may be encountered by public health researchers using webRDS methods. PMID:22846248

Sampling Methodologies for Epidemiologic Surveillance of Men Who Have Sex with Men and Transgender Women in Latin America: An Empiric Comparison of Convenience Sampling, Time Space Sampling, and Respondent Driven Sampling

PubMed Central

Clark, J. L.; Konda, K. A.; Silva-Santisteban, A.; Peinado, J.; Lama, J. R.; Kusunoki, L.; Perez-Brumer, A.; Pun, M.; Cabello, R.; Sebastian, J. L.; Suarez-Ognio, L.; Sanchez, J.

2014-01-01

Alternatives to convenience sampling (CS) are needed for HIV/STI surveillance of most-at-risk populations in Latin America. We compared CS, time space sampling (TSS), and respondent driven sampling (RDS) for recruitment of men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. During concurrent 60-day periods from June–August, 2011, we recruited MSM/TW for epidemiologic surveillance using CS, TSS, and RDS. A total of 748 participants were recruited through CS, 233 through TSS, and 127 through RDS. The TSS sample included the largest proportion of TW (30.7 %) and the lowest percentage of subjects who had previously participated in HIV/STI research (14.9 %). The prevalence of newly diagnosed HIV infection, according to participants’ self-reported previous HIV diagnosis, was highest among TSS recruits (17.9 %) compared with RDS (12.6 %) and CS (10.2 %). TSS identified diverse populations of MSM/TW with higher prevalences of HIV/STIs not accessed by other methods. PMID:24362754

Sampling methodologies for epidemiologic surveillance of men who have sex with men and transgender women in Latin America: an empiric comparison of convenience sampling, time space sampling, and respondent driven sampling.

PubMed

Clark, J L; Konda, K A; Silva-Santisteban, A; Peinado, J; Lama, J R; Kusunoki, L; Perez-Brumer, A; Pun, M; Cabello, R; Sebastian, J L; Suarez-Ognio, L; Sanchez, J

2014-12-01

Alternatives to convenience sampling (CS) are needed for HIV/STI surveillance of most-at-risk populations in Latin America. We compared CS, time space sampling (TSS), and respondent driven sampling (RDS) for recruitment of men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. During concurrent 60-day periods from June-August, 2011, we recruited MSM/TW for epidemiologic surveillance using CS, TSS, and RDS. A total of 748 participants were recruited through CS, 233 through TSS, and 127 through RDS. The TSS sample included the largest proportion of TW (30.7 %) and the lowest percentage of subjects who had previously participated in HIV/STI research (14.9 %). The prevalence of newly diagnosed HIV infection, according to participants' self-reported previous HIV diagnosis, was highest among TSS recruits (17.9 %) compared with RDS (12.6 %) and CS (10.2 %). TSS identified diverse populations of MSM/TW with higher prevalences of HIV/STIs not accessed by other methods.

Probability Sampling Method for a Hidden Population Using Respondent-Driven Sampling: Simulation for Cancer Survivors.

PubMed

Jung, Minsoo

2015-01-01

When there is no sampling frame within a certain group or the group is concerned that making its population public would bring social stigma, we say the population is hidden. It is difficult to approach this kind of population survey-methodologically because the response rate is low and its members are not quite honest with their responses when probability sampling is used. The only alternative known to address the problems caused by previous methods such as snowball sampling is respondent-driven sampling (RDS), which was developed by Heckathorn and his colleagues. RDS is based on a Markov chain, and uses the social network information of the respondent. This characteristic allows for probability sampling when we survey a hidden population. We verified through computer simulation whether RDS can be used on a hidden population of cancer survivors. According to the simulation results of this thesis, the chain-referral sampling of RDS tends to minimize as the sample gets bigger, and it becomes stabilized as the wave progresses. Therefore, it shows that the final sample information can be completely independent from the initial seeds if a certain level of sample size is secured even if the initial seeds were selected through convenient sampling. Thus, RDS can be considered as an alternative which can improve upon both key informant sampling and ethnographic surveys, and it needs to be utilized for various cases domestically as well.

A comparison of respondent-driven and venue-based sampling of female sex workers in Liuzhou, China

PubMed Central

Weir, Sharon S; Merli, M Giovanna; Li, Jing; Gandhi, Anisha D; Neely, William W; Edwards, Jessie K; Suchindran, Chirayath M; Henderson, Gail E; Chen, Xiang-Sheng

2012-01-01

Objectives To compare two methods for sampling female sex workers (FSWs) for bio-behavioural surveillance. We compared the populations of sex workers recruited by the venue-based Priorities for Local AIDS Control Efforts (PLACE) method and a concurrently implemented network-based sampling method, respondent-driven sampling (RDS), in Liuzhou, China. Methods For the PLACE protocol, all female workers at a stratified random sample of venues identified as places where people meet new sexual partners were interviewed and tested for syphilis. Female workers who reported sex work in the past 4 weeks were categorised as FSWs. RDS used peer recruitment and chain referral to obtain a sample of FSWs. Data were collected between October 2009 and January 2010. We compared the socio-demographic characteristics and the percentage with a positive syphilis test of FSWs recruited by PLACE and RDS. Results The prevalence of a positive syphilis test was 24% among FSWs recruited by PLACE and 8.5% among those recruited by RDS and tested (prevalence ratio 3.3; 95% CI 1.5 to 7.2). Socio-demographic characteristics (age, residence and monthly income) also varied by sampling method. PLACE recruited fewer FSWs than RDS (161 vs 583), was more labour-intensive and had difficulty gaining access to some venues. RDS was more likely to recruit from areas near the RDS office and from large low prevalence entertainment venues. Conclusions Surveillance protocols using different sampling methods can obtain different estimates of prevalence and population characteristics. Venue-based and network-based methods each have strengths and limitations reflecting differences in design and assumptions. We recommend that more research be conducted on measuring bias in bio-behavioural surveillance. PMID:23172350

Does size really matter? A sensitivity analysis of number of seeds in a respondent-driven sampling study of gay, bisexual and other men who have sex with men in Vancouver, Canada.

PubMed

Lachowsky, Nathan John; Sorge, Justin Tyler; Raymond, Henry Fisher; Cui, Zishan; Sereda, Paul; Rich, Ashleigh; Roth, Eric A; Hogg, Robert S; Moore, David M

2016-11-16

Respondent-driven sampling (RDS) is an increasingly used peer chain-recruitment method to sample "hard-to-reach" populations for whom there are no reliable sampling frames. Implementation success of RDS varies; one potential negative factor being the number of seeds used. We conducted a sensitivity analysis on estimates produced using data from an RDS study of gay, bisexual and other men who have sex with men (GBMSM) aged ≥16 years living in Vancouver, Canada. Participants completed a questionnaire on demographics, sexual behavior and substance use. For analysis, we used increasing seed exclusion criteria, starting with all participants and subsequently removing unproductive seeds, chains of ≤1 recruitment waves, and chains of ≤2 recruitment waves. We calculated estimates for three different outcomes (HIV serostatus, condomless anal intercourse with HIV discordant/unknown status partner, and injecting drugs) using three different RDS weighting procedures: RDS-I, RDS-II, and RDS-SS. We also assessed seed dependence with bottleneck analyses and convergence plots. Statistical differences between RDS estimators were assessed through simulation analysis. Overall, 719 participants were recruited, which included 119 seeds and a maximum of 16 recruitment waves (mean chain length = 1.7). The sample of >0 recruitment waves removed unproductive seeds (n = 50/119, 42.0%), resulting in 69 chains (mean length = 3.0). The sample of >1 recruitment waves removed 125 seeds or recruits (17.4% of overall sample), resulting in 37 chains (mean length = 4.8). The final sample of >2 recruitment waves removed a further 182 seeds or recruits (25.3% of overall sample), resulting in 25 chains (mean length = 6.1). Convergence plots and bottleneck analyses of condomless anal intercourse with HIV discordant/unknown status partner and injecting drugs outcomes were satisfactory. For these two outcomes, regardless of seed exclusion criteria used, the crude proportions fell within 95% confidence intervals of all RDS-weighted estimates. Significant differences between the three RDS estimators were not observed. Within a sample of GBMSM in Vancouver, Canada, this RDS study suggests that when equilibrium and homophily are met, although potentially costly and time consuming, analysis is not negatively affected by large numbers of unproductive or lowly productive seeds.

Respondent-Driven Sampling in a Multi-Site Study of Black and Latino Men Who Have Sex with Men.

PubMed

Murrill, Christopher S; Bingham, Trista; Lauby, Jennifer; Liu, Kai-Lih; Wheeler, Darrell; Carballo-Diéguez, Alex; Marks, Gary; Millett, Gregorio A

2016-02-01

Respondent-driven sampling (RDS) was used to recruit four samples of Black and Latino men who have sex with men (MSM) in three metropolitan areas to measure HIV prevalence and sexual and drug use behaviors. We compared demographic and behavioral risk characteristics of participants across sites, assessed the extent to which the RDS statistical adjustment procedure provides estimates that differ from the crude results, and summarized our experiences using RDS. From June 2005 to March 2006 a total of 2,235 MSM were recruited and interviewed: 614 Black MSM and 516 Latino MSM in New York City, 540 Black MSM in Philadelphia, and 565 Latino MSM in Los Angeles County. Crude point estimates for demographic characteristics, behavioral risk factors and HIV prevalence were calculated for each of the four samples. RDS Analysis Tool was used to obtain population-based estimates of each sampled population's characteristics. RDS adjusted estimates were similar to the crude estimates for each study sample on demographic characteristics such as age, income, education and employment status. Adjusted estimates of the prevalence of risk behaviors were lower than the crude estimates, and for three of the study samples, the adjusted HIV prevalence estimates were lower than the crude estimates. However, even the adjusted HIV prevalence estimates were higher than what has been previously estimated for these groups of MSM in these cities. Each site faced unique circumstances in implementing RDS. Our experience in using RDS among Black and Latino MSM resulted in diverse recruitment patterns and uncertainties in the estimated HIV prevalence and risk behaviors by study site. Copyright © 2016. Published by Elsevier Inc.

Efficacy of convenience sampling through the internet versus respondent driven sampling among males who have sex with males in Tallinn and Harju County, Estonia: challenges reaching a hidden population.

PubMed

Johnston, Lisa Grazina; Trummal, Aire; Lohmus, Liilia; Ravalepik, Ardi

2009-09-01

This paper examines challenges obtaining representative samples of males who have sex with males (MSM) in Estonia and provides descriptive HIV behavioral data gathered from four cross-sectional surveys; three using the internet, and one using respondent driven sampling (RDS) to recruit MSM in Tallinn and Harju County. Estonian MSM were sampled between March and May in 2004 (n=193), August and November in 2005 (n=146) and September and December in 2007 (n=238) using internet websites. MSM in Tallinn and Harju County were sampled between April and June in 2007 (n=59) using RDS. Recruitment of MSM using RDS did not acquire the calculated sample size. The RDS study reached a less diverse group of MSM than did the internet studies which recruited a larger proportion of MSM who were older, bisexual, having female sexual partners during the last six months, and unlikely to have been tested for HIV. The findings and observations presented in this paper could inform researchers in Estonia, and the region, about the efficacy of and socio-cultural challenges to sampling MSM to collect HIV biological and/or behavioral data.

Hepatitis C bio-behavioural surveys in people who inject drugs-a systematic review of sensitivity to the theoretical assumptions of respondent driven sampling.

PubMed

Buchanan, Ryan; Khakoo, Salim I; Coad, Jonathan; Grellier, Leonie; Parkes, Julie

2017-07-11

New, more effective and better-tolerated therapies for hepatitis C (HCV) have made the elimination of HCV a feasible objective. However, for this to be achieved, it is necessary to have a detailed understanding of HCV epidemiology in people who inject drugs (PWID). Respondent-driven sampling (RDS) can provide prevalence estimates in hidden populations such as PWID. The aims of this systematic review are to identify published studies that use RDS in PWID to measure the prevalence of HCV, and compare each study against the STROBE-RDS checklist to assess their sensitivity to the theoretical assumptions underlying RDS. Searches were undertaken in accordance with PRISMA systematic review guidelines. Included studies were English language publications in peer-reviewed journals, which reported the use of RDS to recruit PWID to an HCV bio-behavioural survey. Data was extracted under three headings: (1) survey overview, (2) survey outcomes, and (3) reporting against selected STROBE-RDS criteria. Thirty-one studies met the inclusion criteria. They varied in scale (range 1-15 survey sites) and the sample sizes achieved (range 81-1000 per survey site) but were consistent in describing the use of standard RDS methods including: seeds, coupons and recruitment incentives. Twenty-seven studies (87%) either calculated or reported the intention to calculate population prevalence estimates for HCV and two used RDS data to calculate the total population size of PWID. Detailed operational and analytical procedures and reporting against selected criteria from the STROBE-RDS checklist varied between studies. There were widespread indications that sampling did not meet the assumptions underlying RDS, which led to two studies being unable to report an estimated HCV population prevalence in at least one survey location. RDS can be used to estimate a population prevalence of HCV in PWID and estimate the PWID population size. Accordingly, as a single instrument, it is a useful tool for guiding HCV elimination. However, future studies should report the operational conduct of each survey in accordance with the STROBE-RDS checklist to indicate sensitivity to the theoretical assumptions underlying the method. PROSPERO CRD42015019245.

"They got their program, and I got mine": a cautionary tale concerning the ethical implications of using respondent-driven sampling to study injection drug users.

PubMed

Scott, Greg

2008-02-01

This article examines the ethical implications of using respondent-driven sampling (RDS) to conduct HIV behaviour surveillance among injection drug users (IDUs) in Chicago. Ethnographic inquiry illustrates how the design and implementation of RDS invites if not promotes manifold violations of federal guidelines governing human research subject protections. Post hoc structured interviews with approximately 13% (n=70) of the behaviour surveillance sample (N=529) focused on how RDS's "dual incentive" structure affected participants' social, economic, and cultural milieu. Triangulated methods include interviews with owners of 20 "shooting galleries", unofficial and illegal locales where IDUs congregate and 400 h of traditional ethnographic observation of individual IDUs and IDU networks. "Consensus analysis" allows identification of key cultural domains that define the RDS coupon market. The study reveals the power of RDS to foment a stratified market of research participation that reinforces pre-existing economic and social inequalities among IDUs. Participants co-opted RDS to develop various "underground" revenue-generating modalities that produced differential risks and benefits among participants. Deleterious outcomes include false advertising regarding the study's risks and benefits, exploitation of relative economic deprivation, generation of sero-discordant social networks, and interpersonal and organised conflict, coercion, and violence. Although RDS may involve serious ethical violations it remains the best available means for accruing a representative sample of hidden populations. It is critical, however, to supplement RDS with research into (1) the subjects' cultural, social, economic, and political contexts, (2) the potential human subjects violations that participants experience, and (3) how these two issues might affect data integrity and interpretation.

Identification of Homophily and Preferential Recruitment in Respondent-Driven Sampling.

PubMed

Crawford, Forrest W; Aronow, Peter M; Zeng, Li; Li, Jianghong

2018-01-01

Respondent-driven sampling (RDS) is a link-tracing procedure used in epidemiologic research on hidden or hard-to-reach populations in which subjects recruit others via their social networks. Estimates from RDS studies may have poor statistical properties due to statistical dependence in sampled subjects' traits. Two distinct mechanisms account for dependence in an RDS study: homophily, the tendency for individuals to share social ties with others exhibiting similar characteristics, and preferential recruitment, in which recruiters do not recruit uniformly at random from their network alters. The different effects of network homophily and preferential recruitment in RDS studies have been a source of confusion and controversy in methodological and empirical research in epidemiology. In this work, we gave formal definitions of homophily and preferential recruitment and showed that neither is identified in typical RDS studies. We derived nonparametric identification regions for homophily and preferential recruitment and showed that these parameters were not identified unless the network took a degenerate form. The results indicated that claims of homophily or recruitment bias measured from empirical RDS studies may not be credible. We applied our identification results to a study involving both a network census and RDS on a population of injection drug users in Hartford, Connecticut (2012-2013). © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Respondent-Driven Sampling: An Assessment of Current Methodology.

PubMed

Gile, Krista J; Handcock, Mark S

2010-08-01

Respondent-Driven Sampling (RDS) employs a variant of a link-tracing network sampling strategy to collect data from hard-to-reach populations. By tracing the links in the underlying social network, the process exploits the social structure to expand the sample and reduce its dependence on the initial (convenience) sample.The current estimators of population averages make strong assumptions in order to treat the data as a probability sample. We evaluate three critical sensitivities of the estimators: to bias induced by the initial sample, to uncontrollable features of respondent behavior, and to the without-replacement structure of sampling.Our analysis indicates: (1) that the convenience sample of seeds can induce bias, and the number of sample waves typically used in RDS is likely insufficient for the type of nodal mixing required to obtain the reputed asymptotic unbiasedness; (2) that preferential referral behavior by respondents leads to bias; (3) that when a substantial fraction of the target population is sampled the current estimators can have substantial bias.This paper sounds a cautionary note for the users of RDS. While current RDS methodology is powerful and clever, the favorable statistical properties claimed for the current estimates are shown to be heavily dependent on often unrealistic assumptions. We recommend ways to improve the methodology.

Respondent driven sampling in a biomonitoring study of refugees from Burma in Buffalo, New York who eat Great Lakes fish.

PubMed

Liu, Ming; McCann, Molly; Lewis-Michl, Elizabeth; Hwang, Syni-An

2018-06-01

Refugees from Burma who consume fish caught from local waterbodies have increased risk of exposure to environmental contaminants. We used respondent driven sampling (RDS) to sample this hard-to-reach population for the first Biomonitoring of Great Lakes Populations program. In the current study, we examined the interview data and assessed the effectiveness of RDS to sample the unique population. In 2013, we used RDS to sample 205 Burmese refugees and immigrants residing in Buffalo, New York who consumed fish caught from Great Lakes waters. RDS-adjusted population estimates of sociodemographic characteristics, residential history, fish consumption related behaviors, and awareness of fish advisories were obtained. We also examined sample homophily and equilibrium to assess how well the RDS assumptions were met in the study. Our sample was diverse with respect to sex, age, years residing in Buffalo, years lived in a refugee camp, education, employment, and fish consumption behaviors, and each of these variables reached equilibrium by the end of recruitment. Burmese refugees in Buffalo consumed Great Lakes fish throughout the year; a majority of them consumed the fish more than two times per week during summer, and about one third ate local fish more than once per week in winter. An estimated 60% of Burmese refugees in Buffalo had heard about local fish advisories. RDS has the potential to be an effective methodology for sampling refugees and immigrants in conducting biomonitoring and environmental exposure assessment. Due to high fish consumption and limited awareness and knowledge of fish advisories, some refugee and immigrant populations are more susceptible to environmental contaminants. Increased awareness on local fish advisories is needed among these populations. Published by Elsevier GmbH.

Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling

PubMed Central

Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

2017-01-01

Background In using regularly collected or existing surveillance data to characterize engagement in human immunodeficiency virus (HIV) services among marginalized populations, differences in sampling methods may produce different pictures of the target population and may therefore result in different priorities for response. Objective The objective of this study was to use existing data to evaluate the sample distribution of eight studies of female sex workers (FSW) and men who have sex with men (MSM), who were recruited using different sampling approaches in two locations within Sub-Saharan Africa: Manzini, Swaziland and Yaoundé, Cameroon. Methods MSM and FSW participants were recruited using either respondent-driven sampling (RDS) or venue-based snowball sampling. Recruitment took place between 2011 and 2016. Participants at each study site were administered a face-to-face survey to assess sociodemographics, along with the prevalence of self-reported HIV status, frequency of HIV testing, stigma, and other HIV-related characteristics. Crude and RDS-adjusted prevalence estimates were calculated. Crude prevalence estimates from the venue-based snowball samples were compared with the overlap of the RDS-adjusted prevalence estimates, between both FSW and MSM in Cameroon and Swaziland. Results RDS samples tended to be younger (MSM aged 18-21 years in Swaziland: 47.6% [139/310] in RDS vs 24.3% [42/173] in Snowball, in Cameroon: 47.9% [99/306] in RDS vs 20.1% [52/259] in Snowball; FSW aged 18-21 years in Swaziland 42.5% [82/325] in RDS vs 8.0% [20/249] in Snowball; in Cameroon 15.6% [75/576] in RDS vs 8.1% [25/306] in Snowball). They were less educated (MSM: primary school completed or less in Swaziland 42.6% [109/310] in RDS vs 4.0% [7/173] in Snowball, in Cameroon 46.2% [138/306] in RDS vs 14.3% [37/259] in Snowball; FSW: primary school completed or less in Swaziland 86.6% [281/325] in RDS vs 23.9% [59/247] in Snowball, in Cameroon 87.4% [520/576] in RDS vs 77.5% [238/307] in Snowball) than the snowball samples. In addition, RDS samples indicated lower exposure to HIV prevention information, less knowledge about HIV prevention, limited access to HIV prevention tools such as condoms, and less-reported frequency of sexually transmitted infections (STI) and HIV testing as compared with the venue-based samples. Findings pertaining to the level of disclosure of sexual practices and sexual practice–related stigma were mixed. Conclusions Samples generated by RDS and venue-based snowball sampling produced significantly different prevalence estimates of several important characteristics. These findings are tempered by limitations to the application of both approaches in practice. Ultimately, these findings provide further context for understanding existing surveillance data and how differences in methods of sampling can influence both the type of individuals captured and whether or not these individuals are representative of the larger target population. These data highlight the need to consider how program coverage estimates of marginalized populations are determined when characterizing the level of unmet need. PMID:29054832

An Empirical Analysis of the Impact of Recruitment Patterns on RDS Estimates among a Socially Ordered Population of Female Sex Workers in China

PubMed Central

Yamanis, Thespina J.; Merli, M. Giovanna; Neely, William Whipple; Tian, Felicia Feng; Moody, James; Tu, Xiaowen; Gao, Ersheng

2013-01-01

Respondent-driven sampling (RDS) is a method for recruiting “hidden” populations through a network-based, chain and peer referral process. RDS recruits hidden populations more effectively than other sampling methods and promises to generate unbiased estimates of their characteristics. RDS’s faithful representation of hidden populations relies on the validity of core assumptions regarding the unobserved referral process. With empirical recruitment data from an RDS study of female sex workers (FSWs) in Shanghai, we assess the RDS assumption that participants recruit nonpreferentially from among their network alters. We also present a bootstrap method for constructing the confidence intervals around RDS estimates. This approach uniquely incorporates real-world features of the population under study (e.g., the sample’s observed branching structure). We then extend this approach to approximate the distribution of RDS estimates under various peer recruitment scenarios consistent with the data as a means to quantify the impact of recruitment bias and of rejection bias on the RDS estimates. We find that the hierarchical social organization of FSWs leads to recruitment biases by constraining RDS recruitment across social classes and introducing bias in the RDS estimates. PMID:24288418

Use of respondent driven sampling (RDS) generates a very diverse sample of men who have sex with men (MSM) in Buenos Aires, Argentina.

PubMed

Carballo-Diéguez, Alex; Balan, Ivan; Marone, Rubén; Pando, María A; Dolezal, Curtis; Barreda, Victoria; Leu, Cheng-Shiun; Avila, María Mercedes

2011-01-01

Prior research focusing on men who have sex with men (MSM) conducted in Buenos Aires, Argentina, used convenience samples that included mainly gay identified men. To increase MSM sample representativeness, we used Respondent Driven Sampling (RDS) for the first time in Argentina. Using RDS, under certain specified conditions, the observed estimates for the percentage of the population with a specific trait are asymptotically unbiased. We describe, the diversity of the recruited sample, from the point of view of sexual orientation, and contrast the different subgroups in terms of their HIV sexual risk behavior. 500 MSM were recruited using RDS. Behavioral data were collected through face-to-face interviews and Web-based CASI. In contrast with prior studies, RDS generated a very diverse sample of MSM from a sexual identity perspective. Only 24.5% of participants identified as gay; 36.2% identified as bisexual, 21.9% as heterosexual, and 17.4% were grouped as "other." Gay and non-gay identified MSM differed significantly in their sexual behavior, the former having higher numbers of partners, more frequent sexual contacts and less frequency of condom use. One third of the men (gay, 3%; bisexual, 34%, heterosexual, 51%; other, 49%) reported having had sex with men, women and transvestites in the two months prior to the interview. This population requires further study and, potentially, HIV prevention strategies tailored to such diversity of partnerships. Our results highlight the potential effectiveness of using RDS to reach non-gay identified MSM. They also present lessons learned in the implementation of RDS to recruit MSM concerning both the importance and limitations of formative work, the need to tailor incentives to circumstances of the less affluent potential participants, the need to prevent masking, and the challenge of assessing network size.

Use of Respondent Driven Sampling (RDS) Generates a Very Diverse Sample of Men Who Have Sex with Men (MSM) in Buenos Aires, Argentina

PubMed Central

Carballo-Diéguez, Alex; Balan, Ivan; Marone, Rubén; Pando, María A.; Dolezal, Curtis; Barreda, Victoria; Leu, Cheng-Shiun; Ávila, María Mercedes

2011-01-01

Background Prior research focusing on men who have sex with men (MSM) conducted in Buenos Aires, Argentina, used convenience samples that included mainly gay identified men. To increase MSM sample representativeness, we used Respondent Driven Sampling (RDS) for the first time in Argentina. Using RDS, under certain specified conditions, the observed estimates for the percentage of the population with a specific trait are asymptotically unbiased. We describe, the diversity of the recruited sample, from the point of view of sexual orientation, and contrast the different subgroups in terms of their HIV sexual risk behavior. Methodology 500 MSM were recruited using RDS. Behavioral data were collected through face-to-face interviews and Web-based CASI. Conclusion In contrast with prior studies, RDS generated a very diverse sample of MSM from a sexual identity perspective. Only 24.5% of participants identified as gay; 36.2% identified as bisexual, 21.9% as heterosexual, and 17.4% were grouped as “other.” Gay and non-gay identified MSM differed significantly in their sexual behavior, the former having higher numbers of partners, more frequent sexual contacts and less frequency of condom use. One third of the men (gay, 3%; bisexual, 34%, heterosexual, 51%; other, 49%) reported having had sex with men, women and transvestites in the two months prior to the interview. This population requires further study and, potentially, HIV prevention strategies tailored to such diversity of partnerships. Our results highlight the potential effectiveness of using RDS to reach non-gay identified MSM. They also present lessons learned in the implementation of RDS to recruit MSM concerning both the importance and limitations of formative work, the need to tailor incentives to circumstances of the less affluent potential participants, the need to prevent masking, and the challenge of assessing network size. PMID:22102896

Sampling Key Populations for HIV Surveillance: Results From Eight Cross-Sectional Studies Using Respondent-Driven Sampling and Venue-Based Snowball Sampling.

PubMed

Rao, Amrita; Stahlman, Shauna; Hargreaves, James; Weir, Sharon; Edwards, Jessie; Rice, Brian; Kochelani, Duncan; Mavimbela, Mpumelelo; Baral, Stefan

2017-10-20

In using regularly collected or existing surveillance data to characterize engagement in human immunodeficiency virus (HIV) services among marginalized populations, differences in sampling methods may produce different pictures of the target population and may therefore result in different priorities for response. The objective of this study was to use existing data to evaluate the sample distribution of eight studies of female sex workers (FSW) and men who have sex with men (MSM), who were recruited using different sampling approaches in two locations within Sub-Saharan Africa: Manzini, Swaziland and Yaoundé, Cameroon. MSM and FSW participants were recruited using either respondent-driven sampling (RDS) or venue-based snowball sampling. Recruitment took place between 2011 and 2016. Participants at each study site were administered a face-to-face survey to assess sociodemographics, along with the prevalence of self-reported HIV status, frequency of HIV testing, stigma, and other HIV-related characteristics. Crude and RDS-adjusted prevalence estimates were calculated. Crude prevalence estimates from the venue-based snowball samples were compared with the overlap of the RDS-adjusted prevalence estimates, between both FSW and MSM in Cameroon and Swaziland. RDS samples tended to be younger (MSM aged 18-21 years in Swaziland: 47.6% [139/310] in RDS vs 24.3% [42/173] in Snowball, in Cameroon: 47.9% [99/306] in RDS vs 20.1% [52/259] in Snowball; FSW aged 18-21 years in Swaziland 42.5% [82/325] in RDS vs 8.0% [20/249] in Snowball; in Cameroon 15.6% [75/576] in RDS vs 8.1% [25/306] in Snowball). They were less educated (MSM: primary school completed or less in Swaziland 42.6% [109/310] in RDS vs 4.0% [7/173] in Snowball, in Cameroon 46.2% [138/306] in RDS vs 14.3% [37/259] in Snowball; FSW: primary school completed or less in Swaziland 86.6% [281/325] in RDS vs 23.9% [59/247] in Snowball, in Cameroon 87.4% [520/576] in RDS vs 77.5% [238/307] in Snowball) than the snowball samples. In addition, RDS samples indicated lower exposure to HIV prevention information, less knowledge about HIV prevention, limited access to HIV prevention tools such as condoms, and less-reported frequency of sexually transmitted infections (STI) and HIV testing as compared with the venue-based samples. Findings pertaining to the level of disclosure of sexual practices and sexual practice-related stigma were mixed. Samples generated by RDS and venue-based snowball sampling produced significantly different prevalence estimates of several important characteristics. These findings are tempered by limitations to the application of both approaches in practice. Ultimately, these findings provide further context for understanding existing surveillance data and how differences in methods of sampling can influence both the type of individuals captured and whether or not these individuals are representative of the larger target population. These data highlight the need to consider how program coverage estimates of marginalized populations are determined when characterizing the level of unmet need. ©Amrita Rao, Shauna Stahlman, James Hargreaves, Sharon Weir, Jessie Edwards, Duncan Kochelani, Duncan Kochelani, Mpumelelo Mavimbela, Stefan Baral. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 20.10.2017.

Reproducibility of Respondent-Driven Sampling (RDS) in Repeat Surveys of Men Who have Sex with Men, Unguja, Zanzibar.

PubMed

Khatib, Ahmed; Haji, Shaaban; Khamis, Maryam; Said, Christen; Khalid, Farhat; Dahoma, Mohammed; Ali, Ameir; Othman, Asha; Welty, Susie; McFarland, Willi

2017-07-01

To assess the reproducibility of respondent-driven sampling (RDS) in obtaining comparable samples across two survey rounds, we conducted integrated bio-behavioral surveillance surveys (IBBSS) using RDS in 2007 and 2011 among men who have sex with men (MSM) on Unguja island in Zanzibar. Differences in the two rounds were assessed by comparing RDS-adjusted population estimates, stratified estimates, and bottleneck plots. Participants in the 2011 survey round were younger (31.4 vs. 9.9% under 19 years old, p < 0.001), more likely to have tested for HIV in the last year (53.7 vs. 10.6%, p < 0.001), and less likely to have injected drugs in the last 3 months (1.0 vs. 23.2%, p < 0.001) compared to participants in the 2007 round. HIV prevalence was 12.3% in 2007 compared to 2.6% in 2011 (p < 0.001). The difference in HIV prevalence persisted after stratifying and adjusting for known differences in the two surveys rounds. Bottleneck plots suggest that recruitment chains were "trapped" in the social networks of MSM who injected drugs to a greater extent in 2007 than in 2011. We conclude that the two rounds of RDS sampled different subsets of the MSM population on Unguja, particularly with respect to inclusion of MSM within the social networks of people who inject drugs. Findings underscore the need to evaluate the reproducibility of RDS in repeated rounds of IBBSS and to develop new sampling methods for key populations at high risk for HIV in order to track the epidemic, develop evidence-based prevention and care programs, and assess their impact.

Condom Use among Immigrant Latino Sexual Minorities: Multilevel Analysis after Respondent-Driven Sampling

PubMed Central

Rhodes, Scott D.; McCoy, Thomas P.

2014-01-01

This study explored correlates of condom use within a respondent-driven sample of 190 Spanish-speaking immigrant Latino sexual minorities, including gay and bisexual men, other men who have sex with men (MSM), and transgender person, in North Carolina. Five analytic approaches for modeling data collected using respondent-driven sampling (RDS) were compared. Across most approaches, knowledge of HIV and sexually transmitted infections (STIs) and increased condom use self-efficacy predicted consistent condom use and increased homophobia predicted decreased consistent condom use. The same correlates were not significant in all analyses but were consistent in most. Clustering due to recruitment chains was low, while clustering due to recruiter was substantial. This highlights the importance accounting for clustering when analyzing RDS data. PMID:25646728

[Respondent-Driven Sampling: a new sampling method to study visible and hidden populations].

PubMed

Mantecón, Alejandro; Juan, Montse; Calafat, Amador; Becoña, Elisardo; Román, Encarna

2008-01-01

The paper introduces a variant of chain-referral sampling: respondent-driven sampling (RDS). This sampling method shows that methods based on network analysis can be combined with the statistical validity of standard probability sampling methods. In this sense, RDS appears to be a mathematical improvement of snowball sampling oriented to the study of hidden populations. However, we try to prove its validity with populations that are not within a sampling frame but can nonetheless be contacted without difficulty. The basics of RDS are explained through our research on young people (aged 14 to 25) who go clubbing, consume alcohol and other drugs, and have sex. Fieldwork was carried out between May and July 2007 in three Spanish regions: Baleares, Galicia and Comunidad Valenciana. The presentation of the study shows the utility of this type of sampling when the population is accessible but there is a difficulty deriving from the lack of a sampling frame. However, the sample obtained is not a random representative one in statistical terms of the target population. It must be acknowledged that the final sample is representative of a 'pseudo-population' that approximates to the target population but is not identical to it.

Respondent-Driven Sampling of Injection Drug Users in Two U.S.–Mexico Border Cities: Recruitment Dynamics and Impact on Estimates of HIV and Syphilis Prevalence

PubMed Central

Brouwer, Kimberly C.; Firestone Cruz, Michelle A.; Ramos, Rebeca; Ramos, Maria Elena; Lozada, Remedios M.; Magis-Rodriguez, Carlos; Strathdee, Steffanie A.

2006-01-01

Respondent-driven sampling (RDS), a chain referral sampling approach, is increasingly used to recruit participants from hard-to-reach populations, such as injection drug users (IDUs). Using RDS, we recruited IDUs in Tijuana and Ciudad (Cd.) Juárez, two Mexican cities bordering San Diego, CA and El Paso, TX, respectively, and compared recruitment dynamics, reported network size, and estimates of HIV and syphilis prevalence. Between February and April 2005, we used RDS to recruit IDUs in Tijuana (15 seeds, 207 recruits) and Cd. Juárez (9 seeds, 197 recruits), Mexico for a cross-sectional study of behavioral and contextual factors associated with HIV, HCV and syphilis infections. All subjects provided informed consent, an anonymous interview, and a venous blood sample for serologic testing of HIV, HCV, HBV (Cd. Juárez only) and syphilis antibody. Log-linear models were used to analyze the association between the state of the recruiter and that of the recruitee in the referral chains, and population estimates of the presence of syphilis antibody were obtained, correcting for biased sampling using RDS-based estimators. Sampling of the targeted 200 recruits per city was achieved rapidly (2 months in Tijuana, 2 weeks in Cd. Juárez). After excluding seeds and missing data, the sample prevalence of HCV, HIV and syphilis were 96.6, 1.9 and 13.5% respectively in Tijuana, and 95.3, 4.1, and 2.7% respectively in Cd. Juárez (where HBV prevalence was 84.7%). Syphilis cases were clustered in recruitment trees. RDS-corrected estimates of syphilis antibody prevalence ranged from 12.8 to 26.8% in Tijuana and from 2.9 to 15.6% in Ciudad Juárez, depending on how recruitment patterns were modeled, and assumptions about how network size affected an individual’s probability of being included in the sample. RDS was an effective method to rapidly recruit IDUs in these cities. Although the frequency of HIV was low, syphilis prevalence was high, particularly in Tijuana. RDS-corrected estimates of syphilis prevalence were sensitive to model assumptions, suggesting that further validation of RDS is necessary. PMID:17072761

Respondent-driven sampling for an adolescent health study in vulnerable urban settings: a multi-country study.

PubMed

Decker, Michele R; Marshall, Beth Dail; Emerson, Mark; Kalamar, Amanda; Covarrubias, Laura; Astone, Nan; Wang, Ziliang; Gao, Ersheng; Mashimbye, Lawrence; Delany-Moretlwe, Sinead; Acharya, Rajib; Olumide, Adesola; Ojengbede, Oladosu; Blum, Robert W; Sonenstein, Freya L

2014-12-01

The global adolescent population is larger than ever before and is rapidly urbanizing. Global surveillance systems to monitor youth health typically use household- and school-based recruitment methods. These systems risk not reaching the most marginalized youth made vulnerable by conditions of migration, civil conflict, and other forms of individual and structural vulnerability. We describe the methodology of the Well-Being of Adolescents in Vulnerable Environments survey, which used respondent-driven sampling (RDS) to recruit male and female youth aged 15-19 years and living in economically distressed urban settings in Baltimore, MD; Johannesburg, South Africa; Ibadan, Nigeria; New Delhi, India; and Shanghai, China (migrant youth only) for a cross-sectional study. We describe a shared recruitment and survey administration protocol across the five sites, present recruitment parameters, and illustrate challenges and necessary adaptations for use of RDS with youth in disadvantaged urban settings. We describe the reach of RDS into populations of youth who may be missed by traditional household- and school-based sampling. Across all sites, an estimated 9.6% were unstably housed; among those enrolled in school, absenteeism was pervasive with 29% having missed over 6 days of school in the past month. Overall findings confirm the feasibility, efficiency, and utility of RDS in quickly reaching diverse samples of youth, including those both in and out of school and those unstably housed, and provide direction for optimizing RDS methods with this population. In our rapidly urbanizing global landscape with an unprecedented youth population, RDS may serve as a valuable tool in complementing existing household- and school-based methods for health-related surveillance that can guide policy. Copyright © 2014 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Respondent-driven sampling for an adolescent health study in vulnerable urban settings: a multi-country study

PubMed Central

Decker, Michele R.; Marshall, Beth; Emerson, Mark; Kalamar, Amanda; Covarrubias, Laura; Astone, Nan; Wang, Ziliang; Gao, Ersheng; Mashimbye, Lawrence; Delany-Moretlwe, Sinead; Acharya, Rajib; Olumide, Adesola; Ojengbede, Oladosu; Blum, Robert

2015-01-01

The global adolescent population is larger than ever before and is rapidly urbanizing. Global surveillance systems to monitor youth health typically use household- and school-based recruitment methods. These systems risk not reaching the most marginalized youth made vulnerable by conditions of migration, civil conflict and other forms of individual and structural vulnerability. We describe the methodology of the Well Being of Adolescents in Vulnerable Environments (WAVE) survey, which used respondent-driven sampling (RDS) to recruit male and female youth aged 15 to 19 years and living in economically distressed urban settings in Baltimore, USA, Johannesburg, South Africa, Ibadan, Nigeria, Delhi, India and Shanghai, China (migrant youth only) for a cross-sectional study. We describe a shared recruitment and survey administration protocol across the five sites, present recruitment parameters, and illustrate challenges and necessary adaptations for use of RDS with youth in disadvantaged urban settings. We describe the reach of RDS into populations of youth who may be missed by traditional householdbased and school-based sampling. Across all sites, an estimated 9.6% were unstably housed; among those enrolled in school, absenteeism was pervasive with 29% having missed over 6 days of school in the past month. Overall findings confirm the feasibility, efficiency and utility of RDS in quickly reaching diverse samples of youth, including those both in and out of school and those unstably housed, and provide direction for optimizing RDS methods with this population. In our rapidly urbanizing global landscape with an unprecedented youth population, RDS may serve as a valuable tool in complementing existing household- and school-based methods for health-related surveillance that can guide policy. PMID:25454005

Conducting a respondent-driven sampling survey with the use of existing resources in Sydney, Australia.

PubMed

Paquette, Dana M; Bryant, Joanne; Crawford, Sione; de Wit, John B F

2011-07-01

Respondent-driven sampling (RDS) is a form of chain-referral sampling that is increasingly being used for HIV behavioural surveillance. When used for surveillance purposes, a sampling method should be relatively inexpensive and simple to operate. This study examined whether an RDS survey of people who inject drugs (PWID) in Sydney, Australia, could be successfully conducted through the use of minimal and existing resources. The RDS survey was conducted on the premises of a local needle and syringe program (NSP) with some adjustments to take into account the constraints of existing resources. The impact of the survey on clients and on staff was examined by summarizing NSP service data and by conducting post-survey discussions with NSP staff. From November 2009 till March 2010, 261 participants were recruited in 16 waves. A significant increase was found in the number of services provided by the NSP during and after data collection. Generally, staff felt that the survey had a positive impact by exposing a broader group of people to the NSP. However, conducting the survey may have led to privacy issues for NSP clients due to an increased number of people gathering around the NSP. This study shows that RDS can be conducted with the use of minimal and existing resources under certain conditions (e.g., use of a self-administered questionnaire and no biological samples taken). A more detailed cost-utility analysis is needed to determine whether RDS' advantages outweigh potential challenges when compared to simpler and less costly convenience methods. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A simulative comparison of respondent driven sampling with incentivized snowball sampling--the "strudel effect".

PubMed

Gyarmathy, V Anna; Johnston, Lisa G; Caplinskiene, Irma; Caplinskas, Saulius; Latkin, Carl A

2014-02-01

Respondent driven sampling (RDS) and incentivized snowball sampling (ISS) are two sampling methods that are commonly used to reach people who inject drugs (PWID). We generated a set of simulated RDS samples on an actual sociometric ISS sample of PWID in Vilnius, Lithuania ("original sample") to assess if the simulated RDS estimates were statistically significantly different from the original ISS sample prevalences for HIV (9.8%), Hepatitis A (43.6%), Hepatitis B (Anti-HBc 43.9% and HBsAg 3.4%), Hepatitis C (87.5%), syphilis (6.8%) and Chlamydia (8.8%) infections and for selected behavioral risk characteristics. The original sample consisted of a large component of 249 people (83% of the sample) and 13 smaller components with 1-12 individuals. Generally, as long as all seeds were recruited from the large component of the original sample, the simulation samples simply recreated the large component. There were no significant differences between the large component and the entire original sample for the characteristics of interest. Altogether 99.2% of 360 simulation sample point estimates were within the confidence interval of the original prevalence values for the characteristics of interest. When population characteristics are reflected in large network components that dominate the population, RDS and ISS may produce samples that have statistically non-different prevalence values, even though some isolated network components may be under-sampled and/or statistically significantly different from the main groups. This so-called "strudel effect" is discussed in the paper. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

A simulative comparison of respondent driven sampling with incentivized snowball sampling – the “strudel effect”

PubMed Central

Gyarmathy, V. Anna; Johnston, Lisa G.; Caplinskiene, Irma; Caplinskas, Saulius; Latkin, Carl A.

2014-01-01

Background Respondent driven sampling (RDS) and Incentivized Snowball Sampling (ISS) are two sampling methods that are commonly used to reach people who inject drugs (PWID). Methods We generated a set of simulated RDS samples on an actual sociometric ISS sample of PWID in Vilnius, Lithuania (“original sample”) to assess if the simulated RDS estimates were statistically significantly different from the original ISS sample prevalences for HIV (9.8%), Hepatitis A (43.6%), Hepatitis B (Anti-HBc 43.9% and HBsAg 3.4%), Hepatitis C (87.5%), syphilis (6.8%) and Chlamydia (8.8%) infections and for selected behavioral risk characteristics. Results The original sample consisted of a large component of 249 people (83% of the sample) and 13 smaller components with 1 to 12 individuals. Generally, as long as all seeds were recruited from the large component of the original sample, the simulation samples simply recreated the large component. There were no significant differences between the large component and the entire original sample for the characteristics of interest. Altogether 99.2% of 360 simulation sample point estimates were within the confidence interval of the original prevalence values for the characteristics of interest. Conclusions When population characteristics are reflected in large network components that dominate the population, RDS and ISS may produce samples that have statistically non-different prevalence values, even though some isolated network components may be under-sampled and/or statistically significantly different from the main groups. This so-called “strudel effect” is discussed in the paper. PMID:24360650

Assessing differences in groups randomized by recruitment chain in a respondent-driven sample of Seattle-area injection drug users.

PubMed

Burt, Richard D; Thiede, Hanne

2014-11-01

Respondent-driven sampling (RDS) is a form of peer-based study recruitment and analysis that incorporates features designed to limit and adjust for biases in traditional snowball sampling. It is being widely used in studies of hidden populations. We report an empirical evaluation of RDS's consistency and variability, comparing groups recruited contemporaneously, by identical methods and using identical survey instruments. We randomized recruitment chains from the RDS-based 2012 National HIV Behavioral Surveillance survey of injection drug users in the Seattle area into two groups and compared them in terms of sociodemographic characteristics, drug-associated risk behaviors, sexual risk behaviors, human immunodeficiency virus (HIV) status and HIV testing frequency. The two groups differed in five of the 18 variables examined (P ≤ .001): race (e.g., 60% white vs. 47%), gender (52% male vs. 67%), area of residence (32% downtown Seattle vs. 44%), an HIV test in the previous 12 months (51% vs. 38%). The difference in serologic HIV status was particularly pronounced (4% positive vs. 18%). In four further randomizations, differences in one to five variables attained this level of significance, although the specific variables involved differed. We found some material differences between the randomized groups. Although the variability of the present study was less than has been reported in serial RDS surveys, these findings indicate caution in the interpretation of RDS results. Copyright © 2014 Elsevier Inc. All rights reserved.

Respondent driven sampling is an effective method for engaging methamphetamine users in HIV prevention research in South Africa

PubMed Central

Kimani, Stephen M.; Watt, Melissa H.; Merli, M. Giovanna; Skinner, Donald; Myers, Bronwyn; Pieterse, Desiree; MacFarlane, Jessica C.; Meade, Christina S.

2014-01-01

Background South Africa, in the midst of the world’s largest HIV epidemic, has a growing methamphetamine problem. Respondent driven sampling (RDS) is a useful tool for recruiting hard-to-reach populations in HIV prevention research, but its use with methamphetamine smokers in South Africa has not been described. This study examined the effectiveness of RDS as a method for engaging methamphetamine users in a Cape Town township into HIV behavioral research. Methods Standard RDS procedures were used to recruit active methamphetamine smokers from a racially diverse peri-urban township in Cape Town. Effectiveness of RDS was determined by examining social network characteristics (network size, homophily, and equilibrium) of recruited participants. Results Beginning with 8 seeds, 345 methamphetamine users were enrolled over 6 months, with a coupon return rate of 67%. The sample included 197 men and 148 women who were racially diverse (73% Coloured, 27% Black African) and had a mean age of 28.8 years (SD=7.2). Social networks were adequate (mean network size >5) and mainly comprised of close social ties. Equilibrium on race was reached after 11 waves of recruitment, and after ≤3 waves for all other variables of interest. There was little to moderate preference for either in- or out-group recruiting in all subgroups. Conclusions Results suggest that RDS is an effective method for engaging methamphetamine users into HIV prevention research in South Africa. Additionally, RDS may be a useful strategy for seeking high-risk methamphetamine users for HIV testing and linkage to HIV care in this and other low resource settings. PMID:25128957

Utility of Respondent Driven Sampling to Reach Disadvantaged Emerging Adults for Assessment of Substance Use, Weight, and Sexual Behaviors.

PubMed

Tucker, Jalie A; Simpson, Cathy A; Chandler, Susan D; Borch, Casey A; Davies, Susan L; Kerbawy, Shatomi J; Lewis, Terri H; Crawford, M Scott; Cheong, JeeWon; Michael, Max

2016-01-01

Emerging adulthood often entails heightened risk-taking with potential life-long consequences, and research on risk behaviors is needed to guide prevention programming, particularly in under-served and difficult to reach populations. This study evaluated the utility of Respondent Driven Sampling (RDS), a peer-driven methodology that corrects limitations of snowball sampling, to reach at-risk African American emerging adults from disadvantaged urban communities. Initial "seed" participants from the target group recruited peers, who then recruited their peers in an iterative process (110 males, 234 females; M age = 18.86 years). Structured field interviews assessed common health risk factors, including substance use, overweight/obesity, and sexual behaviors. Established gender-and age-related associations with risk factors were replicated, and sample risk profiles and prevalence estimates compared favorably with matched samples from representative U.S. national surveys. Findings supported the use of RDS as a sampling method and grassroots platform for research and prevention with community-dwelling risk groups.

Evaluating outcome-correlated recruitment and geographic recruitment bias in a respondent-driven sample of people who inject drugs in Tijuana, Mexico.

PubMed

Rudolph, Abby E; Gaines, Tommi L; Lozada, Remedios; Vera, Alicia; Brouwer, Kimberly C

2014-12-01

Respondent-driven sampling's (RDS) widespread use and reliance on untested assumptions suggests a need for new exploratory/diagnostic tests. We assessed geographic recruitment bias and outcome-correlated recruitment among 1,048 RDS-recruited people who inject drugs (Tijuana, Mexico). Surveys gathered demographics, drug/sex behaviors, activity locations, and recruiter-recruit pairs. Simulations assessed geographic and network clustering of active syphilis (RPR titers ≥1:8). Gender-specific predicted probabilities were estimated using logistic regression with GEE and robust standard errors. Active syphilis prevalence was 7 % (crude: men = 5.7 % and women = 16.6 %; RDS-adjusted: men = 6.7 % and women = 7.6 %). Syphilis clustered in the Zona Norte, a neighborhood known for drug and sex markets. Network simulations revealed geographic recruitment bias and non-random recruitment by syphilis status. Gender-specific prevalence estimates accounting for clustering were highest among those living/working/injecting/buying drugs in the Zona Norte and directly/indirectly connected to syphilis cases (men: 15.9 %, women: 25.6 %) and lowest among those with neither exposure (men: 3.0 %, women: 6.1 %). Future RDS analyses should assess/account for network and spatial dependencies.

An Immunization Strategy for Hidden Populations.

PubMed

Chen, Saran; Lu, Xin

2017-06-12

Hidden populations, such as injecting drug users (IDUs), sex workers (SWs) and men who have sex with men (MSM), are considered at high risk of contracting and transmitting infectious diseases such as AIDS, gonorrhea, syphilis etc. However, public health interventions to such groups are prohibited due to strong privacy concerns and lack of global information, which is a necessity for traditional strategies such as targeted immunization and acquaintance immunization. In this study, we introduce an innovative intervention strategy to be used in combination with a sampling approach that is widely used for hidden populations, Respondent-driven Sampling (RDS). The RDS strategy is implemented in two steps: First, RDS is used to estimate the average degree (personal network size) and degree distribution of the target population with sample data. Second, a cut-off threshold is calculated and used to screen the respondents to be immunized. Simulations on model networks and real-world networks reveal that the efficiency of the RDS strategy is close to that of the targeted strategy. As the new strategy can be implemented with the RDS sampling process, it provides a cost-efficient and feasible approach for disease intervention and control for hidden populations.

Overlooked Threats to Respondent Driven Sampling Estimators: Peer Recruitment Reality, Degree Measures, and Random Selection Assumption.

PubMed

Li, Jianghong; Valente, Thomas W; Shin, Hee-Sung; Weeks, Margaret; Zelenev, Alexei; Moothi, Gayatri; Mosher, Heather; Heimer, Robert; Robles, Eduardo; Palmer, Greg; Obidoa, Chinekwu

2017-06-28

Intensive sociometric network data were collected from a typical respondent driven sample (RDS) of 528 people who inject drugs residing in Hartford, Connecticut in 2012-2013. This rich dataset enabled us to analyze a large number of unobserved network nodes and ties for the purpose of assessing common assumptions underlying RDS estimators. Results show that several assumptions central to RDS estimators, such as random selection, enrollment probability proportional to degree, and recruitment occurring over recruiter's network ties, were violated. These problems stem from an overly simplistic conceptualization of peer recruitment processes and dynamics. We found nearly half of participants were recruited via coupon redistribution on the street. Non-uniform patterns occurred in multiple recruitment stages related to both recruiter behavior (choosing and reaching alters, passing coupons, etc.) and recruit behavior (accepting/rejecting coupons, failing to enter study, passing coupons to others). Some factors associated with these patterns were also associated with HIV risk.

Online respondent-driven sampling for studying contact patterns relevant for the spread of close-contact pathogens: a pilot study in Thailand.

PubMed

Stein, Mart L; van Steenbergen, Jim E; Chanyasanha, Charnchudhi; Tipayamongkholgul, Mathuros; Buskens, Vincent; van der Heijden, Peter G M; Sabaiwan, Wasamon; Bengtsson, Linus; Lu, Xin; Thorson, Anna E; Kretzschmar, Mirjam E E

2014-01-01

Information on social interactions is needed to understand the spread of airborne infections through a population. Previous studies mostly collected egocentric information of independent respondents with self-reported information about contacts. Respondent-driven sampling (RDS) is a sampling technique allowing respondents to recruit contacts from their social network. We explored the feasibility of webRDS for studying contact patterns relevant for the spread of respiratory pathogens. We developed a webRDS system for facilitating and tracking recruitment by Facebook and email. One-day diary surveys were conducted by applying webRDS among a convenience sample of Thai students. Students were asked to record numbers of contacts at different settings and self-reported influenza-like-illness symptoms, and to recruit four contacts whom they had met in the previous week. Contacts were asked to do the same to create a network tree of socially connected individuals. Correlations between linked individuals were analysed to investigate assortativity within networks. We reached up to 6 waves of contacts of initial respondents, using only non-material incentives. Forty-four (23.0%) of the initially approached students recruited one or more contacts. In total 257 persons participated, of which 168 (65.4%) were recruited by others. Facebook was the most popular recruitment option (45.1%). Strong assortative mixing was seen by age, gender and education, indicating a tendency of respondents to connect to contacts with similar characteristics. Random mixing was seen by reported number of daily contacts. Despite methodological challenges (e.g. clustering among respondents and their contacts), applying RDS provides new insights in mixing patterns relevant for close-contact infections in real-world networks. Such information increases our knowledge of the transmission of respiratory infections within populations and can be used to improve existing modelling approaches. It is worthwhile to further develop and explore webRDS for the detection of clusters of respiratory symptoms in social networks.

Online Respondent-Driven Sampling for Studying Contact Patterns Relevant for the Spread of Close-Contact Pathogens: A Pilot Study in Thailand

PubMed Central

Stein, Mart L.; van Steenbergen, Jim E.; Chanyasanha, Charnchudhi; Tipayamongkholgul, Mathuros; Buskens, Vincent; van der Heijden, Peter G. M.; Sabaiwan, Wasamon; Bengtsson, Linus; Lu, Xin; Thorson, Anna E.; Kretzschmar, Mirjam E. E.

2014-01-01

Background Information on social interactions is needed to understand the spread of airborne infections through a population. Previous studies mostly collected egocentric information of independent respondents with self-reported information about contacts. Respondent-driven sampling (RDS) is a sampling technique allowing respondents to recruit contacts from their social network. We explored the feasibility of webRDS for studying contact patterns relevant for the spread of respiratory pathogens. Materials and Methods We developed a webRDS system for facilitating and tracking recruitment by Facebook and email. One-day diary surveys were conducted by applying webRDS among a convenience sample of Thai students. Students were asked to record numbers of contacts at different settings and self-reported influenza-like-illness symptoms, and to recruit four contacts whom they had met in the previous week. Contacts were asked to do the same to create a network tree of socially connected individuals. Correlations between linked individuals were analysed to investigate assortativity within networks. Results We reached up to 6 waves of contacts of initial respondents, using only non-material incentives. Forty-four (23.0%) of the initially approached students recruited one or more contacts. In total 257 persons participated, of which 168 (65.4%) were recruited by others. Facebook was the most popular recruitment option (45.1%). Strong assortative mixing was seen by age, gender and education, indicating a tendency of respondents to connect to contacts with similar characteristics. Random mixing was seen by reported number of daily contacts. Conclusions Despite methodological challenges (e.g. clustering among respondents and their contacts), applying RDS provides new insights in mixing patterns relevant for close-contact infections in real-world networks. Such information increases our knowledge of the transmission of respiratory infections within populations and can be used to improve existing modelling approaches. It is worthwhile to further develop and explore webRDS for the detection of clusters of respiratory symptoms in social networks. PMID:24416371

Our Health Counts Toronto: using respondent-driven sampling to unmask census undercounts of an urban indigenous population in Toronto, Canada.

PubMed

Rotondi, Michael A; O'Campo, Patricia; O'Brien, Kristen; Firestone, Michelle; Wolfe, Sara H; Bourgeois, Cheryllee; Smylie, Janet K

2017-12-26

To provide evidence of the magnitude of census undercounts of 'hard-to-reach' subpopulations and to improve estimation of the size of the urban indigenous population in Toronto, Canada, using respondent-driven sampling (RDS). Respondent-driven sampling. The study took place in the urban indigenous community in Toronto, Canada. Three locations within the city were used to recruit study participants. 908 adult participants (15+) who self-identified as indigenous (First Nation, Inuit or Métis) and lived in the city of Toronto. Study participants were generally young with over 60% of indigenous adults under the age of 45 years. Household income was low with approximately two-thirds of the sample living in households which earned less than $C20 000 last year. We collected baseline data on demographic characteristics, including indigenous identity, age, gender, income, household type and household size. Our primary outcome asked: 'Did you complete the 2011 Census Canada questionnaire?' Using RDS and our large-scale survey of the urban indigenous population in Toronto, Canada, we have shown that the most recent Canadian census underestimated the size of the indigenous population in Toronto by a factor of 2 to 4. Specifically, under conservative assumptions, there are approximately 55 000 (95% CI 45 000 to 73 000) indigenous people living in Toronto, at least double the current estimate of 19 270. Our indigenous enumeration methods, including RDS and census completion information will have broad impacts across governmental and health policy, potentially improving healthcare access for this community. These novel applications of RDS may be relevant for the enumeration of other 'hard-to-reach' populations, such as illegal immigrants or homeless individuals in Canada and beyond. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluating outcome-correlated recruitment and geographic recruitment bias in a respondent-driven sample of people who inject drugs in Tijuana, Mexico

PubMed Central

Rudolph, Abby E.; Gaines, Tommi L.; Lozada, Remedios; Vera, Alicia; Brouwer, Kimberly C.

2015-01-01

Respondent-driven sampling’s (RDS) widespread use and reliance on untested assumptions suggests a need for new exploratory/diagnostic tests. We assessed geographic recruitment bias and outcome-correlated recruitment among 1048 RDS-recruited people who inject drugs (Tijuana, Mexico). Surveys gathered demographics, drug/sex behaviors, activity locations, and recruiter-recruit pairs. Simulations assessed geographic and network clustering of active syphilis (RPR titers≥1:8). Gender-specific predicted probabilities were estimated using logistic regression with GEE and robust standard errors. Active syphilis prevalence was 7% (crude: men=5.7% and women=16.6%; RDS-adjusted: men=6.7% and women=7.6%). Syphilis clustered in the Zona Norte, a neighborhood known for drug and sex markets. Network simulations revealed geographic recruitment bias and non-random recruitment by syphilis status. Gender-specific prevalence estimates accounting for clustering were highest among those living/working/injecting/buying drugs in the Zona Norte and directly/indirectly connected to syphilis cases (men:15.9%, women:25.6%) and lowest among those with neither exposure (men:3.0%, women:6.1%). Future RDS analyses should assess/account for network and spatial dependencies. PMID:24969586

Methodological Challenges in Collecting Social and Behavioural Data Regarding the HIV Epidemic among Gay and Other Men Who Have Sex with Men in Australia

PubMed Central

Holt, Martin; de Wit, John; Brown, Graham; Maycock, Bruce; Fairley, Christopher; Prestage, Garrett

2014-01-01

Background Behavioural surveillance and research among gay and other men who have sex with men (GMSM) commonly relies on non-random recruitment approaches. Methodological challenges limit their ability to accurately represent the population of adult GMSM. We compared the social and behavioural profiles of GMSM recruited via venue-based, online, and respondent-driven sampling (RDS) and discussed their utility for behavioural surveillance. Methods Data from four studies were selected to reflect each recruitment method. We compared demographic characteristics and the prevalence of key indicators including sexual and HIV testing practices obtained from samples recruited through different methods, and population estimates from respondent-driven sampling partition analysis. Results Overall, the socio-demographic profile of GMSM was similar across samples, with some differences observed in age and sexual identification. Men recruited through time-location sampling appeared more connected to the gay community, reported a greater number of sexual partners, but engaged in less unprotected anal intercourse with regular (UAIR) or casual partners (UAIC). The RDS sample overestimated the proportion of HIV-positive men and appeared to recruit men with an overall higher number of sexual partners. A single-website survey recruited a sample with characteristics which differed considerably from the population estimates with regards to age, ethnically diversity and behaviour. Data acquired through time-location sampling underestimated the rates of UAIR and UAIC, while RDS and online sampling both generated samples that underestimated UAIR. Simulated composite samples combining recruits from time-location and multi-website online sampling may produce characteristics more consistent with the population estimates, particularly with regards to sexual practices. Conclusion Respondent-driven sampling produced the sample that was most consistent to population estimates, but this methodology is complex and logistically demanding. Time-location and online recruitment are more cost-effective and easier to implement; using these approaches in combination may offer the potential to recruit a more representative sample of GMSM. PMID:25409440

Methodological challenges in collecting social and behavioural data regarding the HIV epidemic among gay and other men who have sex with men in Australia.

PubMed

Zablotska, Iryna B; Frankland, Andrew; Holt, Martin; de Wit, John; Brown, Graham; Maycock, Bruce; Fairley, Christopher; Prestage, Garrett

2014-01-01

Behavioural surveillance and research among gay and other men who have sex with men (GMSM) commonly relies on non-random recruitment approaches. Methodological challenges limit their ability to accurately represent the population of adult GMSM. We compared the social and behavioural profiles of GMSM recruited via venue-based, online, and respondent-driven sampling (RDS) and discussed their utility for behavioural surveillance. Data from four studies were selected to reflect each recruitment method. We compared demographic characteristics and the prevalence of key indicators including sexual and HIV testing practices obtained from samples recruited through different methods, and population estimates from respondent-driven sampling partition analysis. Overall, the socio-demographic profile of GMSM was similar across samples, with some differences observed in age and sexual identification. Men recruited through time-location sampling appeared more connected to the gay community, reported a greater number of sexual partners, but engaged in less unprotected anal intercourse with regular (UAIR) or casual partners (UAIC). The RDS sample overestimated the proportion of HIV-positive men and appeared to recruit men with an overall higher number of sexual partners. A single-website survey recruited a sample with characteristics which differed considerably from the population estimates with regards to age, ethnically diversity and behaviour. Data acquired through time-location sampling underestimated the rates of UAIR and UAIC, while RDS and online sampling both generated samples that underestimated UAIR. Simulated composite samples combining recruits from time-location and multi-website online sampling may produce characteristics more consistent with the population estimates, particularly with regards to sexual practices. Respondent-driven sampling produced the sample that was most consistent to population estimates, but this methodology is complex and logistically demanding. Time-location and online recruitment are more cost-effective and easier to implement; using these approaches in combination may offer the potential to recruit a more representative sample of GMSM.

Using Respondent-Driven Sampling to Recruit Illegal Drug Purchasers to Evaluate a Drug Market Intervention.

PubMed

Ober, Allison J; Sussell, Jesse; Kilmer, Beau; Saunders, Jessica; Heckathorn, Douglas D

2016-04-01

Violent drug markets are not as prominent as they once were in the United States, but they still exist and are associated with significant crime and lower quality of life. The drug market intervention (DMI) is an innovative strategy that uses focused deterrence, community engagement, and incapacitation to reduce crime and disorder associated with these markets. Although studies show that DMI can reduce crime and overt drug activity, one perspective is prominently missing from these evaluations: those who purchase drugs. This study explores the use of respondent-driven sampling (RDS)-a statistical sampling method-to approximate a representative sample of drug users who purchased drugs in a targeted DMI market to gain insight into the effect of a DMI on market dynamics. Using RDS, we recruited individuals who reported hard drug use (crack or powder cocaine, heroin, methamphetamine, or illicit use of prescriptions opioids) in the last month to participate in a survey. The main survey asked about drug use, drug purchasing, and drug market activity before and after DMI; a secondary survey asked about network characteristics and recruitment. Our sample of 212 respondents met key RDS assumptions, suggesting that the characteristics of our weighted sample approximate the characteristics of the drug user network. The weighted estimates for market purchasers are generally valid for inferences about the aggregate population of customers, but a larger sample size is needed to make stronger inferences about the effects of a DMI on drug market activity. © The Author(s) 2016.

A qualitative analysis of peer recruitment pressures in respondent driven sampling: Are risks above the ethical limit?

PubMed

Mosher, Heather I; Moorthi, Gayatri; Li, JiangHong; Weeks, Margaret R

2015-09-01

This paper examines peer recruitment dynamics through respondent driven sampling (RDS) with a sample of injection drug users in Hartford, CT to understand the strategies participants use to recruit peers into a study and the extent to which these strategies may introduce risks above the ethical limit despite safeguards in RDS. Out of 526 injection drug users who participated in a mixed-method RDS methodology evaluation study, a nested sample of 61 participants completed an in-depth semi-structured interview at a 2-month follow-up to explore their experiences with the recruitment process. Findings revealed that participants used a variety of strategies to recruit peers, ranging from one-time interactions to more persistent strategies to encourage participation (e.g., selecting peers that can easily be found and contacted later, following up with peers to remind them of their appointment, accompanying peers to the study site, etc.). Some participants described the more persistent strategies as helpful, while some others experienced these strategies as minor peer pressure, creating a feeling of obligation to participate. Narratives revealed that overall, the probability of experiencing study-related risks remains relatively low for most participants; however, a disconcerting finding was that higher study-related risks (e.g., relationship conflict, loss of relationship, physical fights, violence) were seen for recruits who participated but switched coupons or for recruits who decided not to participate in the study and did not return the coupon to the recruiter. Findings indicate that peer recruitment practices in RDS generally pose minimal risk, but that peer recruitment may occasionally exceed the ethical limit, and that enhanced safeguards for studies using peer recruitment methods are recommended. Suggestions for possible enhancements are described. Copyright © 2015 Elsevier B.V. All rights reserved.

Feasibility of Recruiting a Diverse Sample of Men Who Have Sex with Men: Observation from Nanjing, China

PubMed Central

Tang, Weiming; Yang, Haitao; Mahapatra, Tanmay; Huan, Xiping; Yan, Hongjing; Li, Jianjun; Fu, Gengfeng; Zhao, Jinkou; Detels, Roger

2013-01-01

Background Respondent-driven-sampling (RDS) has well been recognized as a method for sampling from most hard-to-reach populations like commercial sex workers, drug users and men who have sex with men. However the feasibility of this sampling strategy in terms of recruiting a diverse spectrum of these hidden populations has not been understood well yet in developing countries. Methods In a cross sectional study in Nanjing city of Jiangsu province of China, 430 MSM were recruited including 9 seeds in 14 weeks of study period using RDS. Information regarding socio-demographic characteristics and sexual risk behavior were collected and testing was done for HIV and syphilis. Duration, completion, participant characteristics and the equilibrium of key factors were used for assessing feasibility of RDS. Homophily of key variables, socio-demographic distribution and social network size were used as the indicators of diversity. Results In the study sample, adjusted HIV and syphilis prevalence were 6.6% and 14.6% respectively. Majority (96.3%) of the participants were recruited by members of their own social network. Although there was a tendency for recruitment within the same self-identified group (homosexuals recruited 60.0% homosexuals), considerable cross-group recruitment (bisexuals recruited 52.3% homosexuals) was also seen. Homophily of the self-identified sexual orientations was 0.111 for homosexuals. Upon completion of the recruitment process, participant characteristics and the equilibrium of key factors indicated that RDS was feasible for sampling MSM in Nanjing. Participants recruited by RDS were found to be diverse after assessing the homophily of key variables in successive waves of recruitment, the proportion of characteristics after reaching equilibrium and the social network size. The observed design effects were nearly the same or even better than the theoretical design effect of 2. Conclusion RDS was found to be an efficient and feasible sampling method for recruiting a diverse sample of MSM in a reasonable time. PMID:24244280

Balancing theory and practice in respondent-driven sampling: a case study of innovations developed to overcome recruitment challenges.

PubMed

Truong, Hong-Ha M; Grasso, Michael; Chen, Yea-Hung; Kellogg, Timothy A; Robertson, Tyler; Curotto, Alberto; Steward, Wayne T; McFarland, Willi

2013-01-01

Respondent-driven sampling (RDS) offers a recruitment strategy for hard-to-reach populations. However, RDS faces logistical and theoretical challenges that threaten efficiency and validity in settings worldwide. We present innovative adaptations to conventional RDS to overcome barriers encountered in recruiting a large, representative sample of men who have sex with men (MSM) who travel internationally. Novel methodological adaptations for the "International Travel Research to Inform Prevention" or "I-TRIP" study were offering participants a choice between electronic and paper coupons referrals for recruitment and modifying the secondary incentives structure from small cash amounts to raffle entries for periodic large cash prize raffle drawings. Staged referral limit increases from 3 to 10 referrals and progressive addition of 70 seeds were also implemented. There were 501 participants enrolled in up to 13 waves of growth. Among participants with a choice of referral methods, 81% selected electronic referrals. Of participants who were recruited electronically, 90% chose to remain with electronic referrals when it was their turn to recruit. The mean number of enrolled referrals was 0.91 for electronic referrals compared to 0.56 for paper coupons. Median referral lag time, i.e., the time interval between when recruiters were given their referrals and when a referred individual enrolled in the study, was 20 days (IQR 10-40) for electronic referrals, 20 days (IQR 8-58) for paper coupons, 20 days (IQR 10-41) for raffle entries and 33 days (IQR 16-148) for small cash incentives. The recruitment of MSM who travel internationally required maximizing known flexible tools of RDS while at the same time necessitating innovations to increase recruitment efficiency. Electronic referrals emerged as a major advantage in recruiting this hard-to-reach population who are of high socio-economic status, geographically diffuse and highly mobile. These enhancements may improve the performance of RDS in target populations with similar characteristics.

Mind the gap: implementation challenges break the link between HIV/AIDS research and practice.

PubMed

MacCarthy, Sarah; Reisner, Sari; Hoffmann, Michael; Perez-Brumer, Amaya; Silva-Santisteban, Alfonso; Nunn, Amy; Bastos, Leonardo; Vasconcellos, Mauricio Teixeira Leite de; Kerr, Ligia; Bastos, Francisco Inácio; Dourado, Inês

2016-11-03

Sampling strategies such as respondent-driven sampling (RDS) and time-location sampling (TLS) offer unique opportunities to access key populations such as men who have sex with men (MSM) and transgender women. Limited work has assessed implementation challenges of these methods. Overcoming implementation challenges can improve research quality and increase uptake of HIV services among key populations. Drawing from studies using RDS in Brazil and TLS in Peru, we summarize challenges encountered in the field and potential strategies to address them. In Brazil, study site selection, cash incentives, and seed selection challenged RDS implementation with MSM. In Peru, expansive geography, safety concerns, and time required for study participation complicated TLS implementation with MSM and transgender women. Formative research, meaningful participation of key populations across stages of research, and transparency in study design are needed to link HIV/AIDS research and practice. Addressing implementation challenges can close gaps in accessing services among those most burdened by the epidemic.

Mind the gap: implementation challenges break the link between HIV/AIDS research and practice

PubMed Central

MacCarthy, Sarah; Reisner, Sari; Hoffmann, Michael; Perez-Brumer, Amaya; Silva-Santisteban, Alfonso; Nunn, Amy; Bastos, Leonardo; de Vasconcellos, Mauricio Teixeira Leite; Kerr, Ligia; Bastos, Francisco Inácio; Dourado, Inês

2018-01-01

Sampling strategies such as respondent-driven sampling (RDS) and time-location sampling (TLS) offer unique opportunities to access key populations such as men who have sex with men (MSM) and transgender women. Limited work has assessed implementation challenges of these methods. Overcoming implementation challenges can improve research quality and increase uptake of HIV services among key populations. Drawing from studies using RDS in Brazil and TLS in Peru, we summarize challenges encountered in the field and potential strategies to address them. In Brazil, study site selection, cash incentives, and seed selection challenged RDS implementation with MSM. In Peru, expansive geography, safety concerns, and time required for study participation complicated TLS implementation with MSM and transgender women. Formative research, meaningful participation of key populations across stages of research, and transparency in study design are needed to link HIV/AIDS research and practice. Addressing implementation challenges can close gaps in accessing services among those most burdened by the epidemic. PMID:27828609

Do recruitment patterns of young men who have sex with men (YMSM) recruited through respondent-driven sampling (RDS) violate assumptions?

PubMed Central

Phillips, Gregory; Kuhns, Lisa M.; Garofalo, Rob; Mustanski, Brian

2014-01-01

Background In order to generate unbiased estimates for data collected using respondent-driven sampling (RDS), a number of assumptions need to be met: individuals recruit randomly from their social network and people can accurately report their eligible network size. However, research has shown that these assumptions are often violated. Methods This study used baseline data from Crew 450, a longitudinal study of young men who have sex with men in Chicago who were recruited via a modified form of RDS, and its network substudy, in which a subset of 175 participants reported details on the composition and characteristics of their social network at either one or two years post-baseline. Results Nearly two-thirds of participants reported giving coupons to at least one alter (64.0%), and 56.3% believed their alter(s) used the coupons. Frequency of communication, closeness, and type of relationship played a major role in determining coupon distribution. Participants whose alters used coupons were significantly less likely to describe the strength of their relationship as “not at all close” (OR = 0.08; 95% CI: 0.02, 0.36) compared to “very close” and to communicate weekly (OR = 0.20; 95% CI: 0.08, 0.49) or 1–6 times in the last 6 months (OR = 0.18; 95% CI: 0.06, 0.59). Conclusion Contrary to RDS assumptions, we found that relationship characteristics played a significant role when individuals decided to whom they would give coupons. PMID:25086159

Statistical design and analysis plan for an impact evaluation of an HIV treatment and prevention intervention for female sex workers in Zimbabwe: a study protocol for a cluster randomised controlled trial.

PubMed

Hargreaves, James R; Fearon, Elizabeth; Davey, Calum; Phillips, Andrew; Cambiano, Valentina; Cowan, Frances M

2016-01-05

Pragmatic cluster-randomised trials should seek to make unbiased estimates of effect and be reported according to CONSORT principles, and the study population should be representative of the target population. This is challenging when conducting trials amongst 'hidden' populations without a sample frame. We describe a pair-matched cluster-randomised trial of a combination HIV-prevention intervention to reduce the proportion of female sex workers (FSW) with a detectable HIV viral load in Zimbabwe, recruiting via respondent driven sampling (RDS). We will cross-sectionally survey approximately 200 FSW at baseline and at endline to characterise each of 14 sites. RDS is a variant of chain referral sampling and has been adapted to approximate random sampling. Primary analysis will use the 'RDS-2' method to estimate cluster summaries and will adapt Hayes and Moulton's '2-step' method to adjust effect estimates for individual-level confounders and further adjust for cluster baseline prevalence. We will adapt CONSORT to accommodate RDS. In the absence of observable refusal rates, we will compare the recruitment process between matched pairs. We will need to investigate whether cluster-specific recruitment or the intervention itself affects the accuracy of the RDS estimation process, potentially causing differential biases. To do this, we will calculate RDS-diagnostic statistics for each cluster at each time point and compare these statistics within matched pairs and time points. Sensitivity analyses will assess the impact of potential biases arising from assumptions made by the RDS-2 estimation. We are not aware of any other completed pragmatic cluster RCTs that are recruiting participants using RDS. Our statistical design and analysis approach seeks to transparently document participant recruitment and allow an assessment of the representativeness of the study to the target population, a key aspect of pragmatic trials. The challenges we have faced in the design of this trial are likely to be shared in other contexts aiming to serve the needs of legally and/or socially marginalised populations for which no sampling frame exists and especially when the social networks of participants are both the target of intervention and the means of recruitment. The trial was registered at Pan African Clinical Trials Registry (PACTR201312000722390) on 9 December 2013.

Whither RDS? An investigation of Respondent Driven Sampling as a method of recruiting mainstream marijuana users

PubMed Central

2010-01-01

Background An important challenge in conducting social research of specific relevance to harm reduction programs is locating hidden populations of consumers of substances like cannabis who typically report few adverse or unwanted consequences of their use. Much of the deviant, pathologized perception of drug users is historically derived from, and empirically supported, by a research emphasis on gaining ready access to users in drug treatment or in prison populations with higher incidence of problems of dependence and misuse. Because they are less visible, responsible recreational users of illicit drugs have been more difficult to study. Methods This article investigates Respondent Driven Sampling (RDS) as a method of recruiting experienced marijuana users representative of users in the general population. Based on sampling conducted in a multi-city study (Halifax, Montreal, Toronto, and Vancouver), and compared to samples gathered using other research methods, we assess the strengths and weaknesses of RDS recruitment as a means of gaining access to illicit substance users who experience few harmful consequences of their use. Demographic characteristics of the sample in Toronto are compared with those of users in a recent household survey and a pilot study of Toronto where the latter utilized nonrandom self-selection of respondents. Results A modified approach to RDS was necessary to attain the target sample size in all four cities (i.e., 40 'users' from each site). The final sample in Toronto was largely similar, however, to marijuana users in a random household survey that was carried out in the same city. Whereas well-educated, married, whites and females in the survey were all somewhat overrepresented, the two samples, overall, were more alike than different with respect to economic status and employment. Furthermore, comparison with a self-selected sample suggests that (even modified) RDS recruitment is a cost-effective way of gathering respondents who are more representative of users in the general population than nonrandom methods of recruitment ordinarily produce. Conclusions Research on marijuana use, and other forms of drug use hidden in the general population of adults, is important for informing and extending harm reduction beyond its current emphasis on 'at-risk' populations. Expanding harm reduction in a normalizing context, through innovative research on users often overlooked, further challenges assumptions about reducing harm through prohibition of drug use and urges consideration of alternative policies such as decriminalization and legal regulation. PMID:20618944

The Where and How for Reaching Transgender Women and Men Who Have Sex with Men with HIV Prevention Services in Guatemala.

PubMed

Miller, William M; Miller, William C; Barrington, Clare; Weir, Sharon S; Chen, Sanny Y; Emch, Michael E; Pettifor, Audrey E; Paz-Bailey, Gabriela

2017-12-01

This study aims to describe the transgender women and men who have sex with men (MSM) missed through venue-based sampling and illustrate how data on venues can be used to prioritize service delivery. Respondent-driven sampling (RDS) and time-location sampling (TLS) were used concurrently in 2010 for behavioral surveillance among MSM and transgender women in Guatemala City. RDS recruits who did not frequent venues (n = 106) were compared to TLS recruits (n = 609). TLS participants recruited at different types of venues were compared. RDS recruits who did not frequent venues were less educated, less likely to identify as gay, more likely to have concurrent partners and female sexual partners. Participants recruited at NGOs, saunas, hotels, streets and parks had more partners, were more likely to receive money for sex or have concurrent partners. Prevention programs for MSM and transgender women should characterize social venues and people that frequent them and improve service coverage through venues and social networks.

Ketamine use among regular tobacco and alcohol users as revealed by respondent driven sampling in Taipei: prevalence, expectancy, and users’ risky decision making

PubMed Central

Chen, Wei J.; Ting, Te-Tien; Chang, Chao-Ming; Liu, Ying-Chun; Chen, Chuan-Yu

2014-01-01

The popularity of ketamine for recreational use among young people began to increase, particularly in Asia, in 2000. To gain more knowledge about the use of ketamine among high risk individuals, a respondent-driven sampling (RDS) was implemented among regular alcohol and tobacco users in the Taipei metropolitan area from 2007 to 2010. The sampling was initiated in three different settings (i.e., two in the community and one in a clinic) to recruit seed individuals. Each participant was asked to refer one to five friends known to be regular tobacco smokers and alcohol drinkers to participate in the present study. Incentives were offered differentially upon the completion of an interview and successful referral. Information pertaining to drug use experience was collected by an audio computer-assisted self-interview instrument. Software built for RDS analyses was used for data analyses. Of the 1,115 subjects recruited, about 11.7% of the RDS respondents reported ever having used ketamine. Positive expectancy of ketamine use was positively associated with ketamine use; in contrast, negative expectancy inversely associated with ketamine use. Decision-making characteristics as measured on the Iowa Gambling Task using reinforcement learning models revealed that ketamine users learned less from the most recent event than both tobacco- and drug-naïve controls and regular tobacco and alcohol users. These findings about ketamine use among young people have implications for its prevention and intervention. PMID:25264412

Do recruitment patterns of young men who have sex with men (YMSM) recruited through respondent-driven sampling (RDS) violate assumptions?

PubMed

Phillips, Gregory; Kuhns, Lisa M; Garofalo, Rob; Mustanski, Brian

2014-12-01

To generate unbiased estimates for data collected using respondent-driven sampling (RDS), a number of assumptions need to be met: individuals recruit randomly from their social network and people can accurately report their eligible network size. However, research has shown that these assumptions are often violated. This study used baseline data from Crew 450, a longitudinal study of young men who have sex with men in Chicago who were recruited via a modified form of RDS and its network substudy, in which a subset of 175 participants reported details on the composition and characteristics of their social network at either 1 or 2 years postbaseline. Nearly two-thirds of participants reported giving coupons to at least one alter (64%), and 56.3% believed their alter(s) used the coupons. Frequency of communication, closeness and type of relationship played a major role in determining coupon distribution. Participants whose alters used coupons were significantly less likely to describe the strength of their relationship as 'not at all close' (OR=0.08; 95% CI 0.02 to 0.36) compared with 'very close' and to communicate weekly (OR=0.20; 95% CI 0.08 to 0.49) or 1-6 times in the past 6 months (OR=0.18; 95% CI 0.06 to 0.59). Contrary to RDS assumptions, we found that relationship characteristics played a significant role when individuals decided to whom they would give coupons. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Including Online-Recruited Seeds: A Respondent-Driven Sample of Men Who Have Sex With Men.

PubMed

Lachowsky, Nathan John; Lal, Allan; Forrest, Jamie I; Card, Kiffer George; Cui, Zishan; Sereda, Paul; Rich, Ashleigh; Raymond, Henry Fisher; Roth, Eric A; Moore, David M; Hogg, Robert S

2016-03-15

Technology has changed the way men who have sex with men (MSM) seek sex and socialize, which may impact the implementation of respondent-driven sampling (RDS) among this population. Initial participants (also known as seeds) are a critical consideration in RDS because they begin the recruitment chains. However, little information is available on how the online-recruited seeds may effect RDS implementation. The objectives of this study were to compare (1) online-recruited versus offline-recruited seeds and (2) subsequent recruitment chains of online-recruited versus offline-recruited seeds. Between 2012 and 2014, we recruited MSM using RDS in Vancouver, Canada. RDS weights were used with logistic regression to address each objective. A total of 119 seeds were used, 85 of whom were online-recruited seeds, to recruit an additional 600 MSM. Compared with offline-recruited seeds, online-recruited seeds were less likely to be HIV-positive (OR 0.34, 95% CI 0.13-0.88), to have attended a gay community group (AOR 0.33, 95% CI 0.12-0.90), and to feel gay community involvement was "very important" (AOR 0.16, 95% CI 0.03-0.93). Online-recruited seeds were more likely to ask a sexual partner's HIV status always versus <50% of the time (AOR 5.21, 95% CI 1.17-23.23), to have watched the Pride parade (AOR 6.30, 95% CI 1.69-23.45), and to have sought sex online (AOR 4.29, 95% CI 1.53-12-12.05). Further, compared with recruitment chains started by offline-recruited seeds, recruits from chains started by online-recruited seeds (283/600, 47.2%) were less likely to be HIV-positive (AOR 0.25, 95% CI 0.16-0.40), to report "versatile" versus "bottom" sexual position preference (AOR 0.56, 95% CI 0.35-0.88), and to be in a relationship lasting >1 year (AOR 1.65, 95% CI 1.06-2.56). Recruits of online seeds were more likely to be out as gay for longer (eg, 11-21 vs 1-4 years, AOR 2.22, 95% CI 1.27-3.88) and have fewer Facebook friends (eg, 201-500 vs >500, AOR 1.69, 95% CI 1.02-2.80). Online-recruited seeds were more prevalent, recruited fewer participants, but were different from those recruited offline. This may therefore help create a more diverse overall sample. Our work has shown the value of geosocial networking apps for aiding RDS recruitment efforts, especially when faced with slow participation uptake by other means. Understanding the degree to which networks interact will be an important next step in confirming the efficacy of online RDS recruitment strategies.

Including Online-Recruited Seeds: A Respondent-Driven Sample of Men Who Have Sex With Men

PubMed Central

Lachowsky, Nathan John; Lal, Allan; Forrest, Jamie I; Card, Kiffer George; Cui, Zishan; Sereda, Paul; Rich, Ashleigh; Raymond, Henry Fisher; Roth, Eric A; Moore, David M

2016-01-01

Background Technology has changed the way men who have sex with men (MSM) seek sex and socialize, which may impact the implementation of respondent-driven sampling (RDS) among this population. Initial participants (also known as seeds) are a critical consideration in RDS because they begin the recruitment chains. However, little information is available on how the online-recruited seeds may effect RDS implementation. Objective The objectives of this study were to compare (1) online-recruited versus offline-recruited seeds and (2) subsequent recruitment chains of online-recruited versus offline-recruited seeds. Methods Between 2012 and 2014, we recruited MSM using RDS in Vancouver, Canada. RDS weights were used with logistic regression to address each objective. Results A total of 119 seeds were used, 85 of whom were online-recruited seeds, to recruit an additional 600 MSM. Compared with offline-recruited seeds, online-recruited seeds were less likely to be HIV-positive (OR 0.34, 95% CI 0.13-0.88), to have attended a gay community group (AOR 0.33, 95% CI 0.12-0.90), and to feel gay community involvement was “very important” (AOR 0.16, 95% CI 0.03-0.93). Online-recruited seeds were more likely to ask a sexual partner’s HIV status always versus <50% of the time (AOR 5.21, 95% CI 1.17-23.23), to have watched the Pride parade (AOR 6.30, 95% CI 1.69-23.45), and to have sought sex online (AOR 4.29, 95% CI 1.53-12-12.05). Further, compared with recruitment chains started by offline-recruited seeds, recruits from chains started by online-recruited seeds (283/600, 47.2%) were less likely to be HIV-positive (AOR 0.25, 95% CI 0.16-0.40), to report “versatile” versus “bottom” sexual position preference (AOR 0.56, 95% CI 0.35-0.88), and to be in a relationship lasting >1 year (AOR 1.65, 95% CI 1.06-2.56). Recruits of online seeds were more likely to be out as gay for longer (eg, 11-21 vs 1-4 years, AOR 2.22, 95% CI 1.27-3.88) and have fewer Facebook friends (eg, 201-500 vs >500, AOR 1.69, 95% CI 1.02-2.80). Conclusions Online-recruited seeds were more prevalent, recruited fewer participants, but were different from those recruited offline. This may therefore help create a more diverse overall sample. Our work has shown the value of geosocial networking apps for aiding RDS recruitment efforts, especially when faced with slow participation uptake by other means. Understanding the degree to which networks interact will be an important next step in confirming the efficacy of online RDS recruitment strategies. PMID:26980147

[A respondent-driven sampling survey on HIV and risk factors among men who have sex with men in Chongqing].

PubMed

Ouyang, Lin; Feng, Lian-gui; Ding, Xian-bin; Zhao, Jin-kou; Xu, Jing; Han, Mei; Zhou, Chao

2009-10-01

To examine HIV prevalence and related risk factors among men who have sex with men (MSM) in Chongqing, and to explore the feasibility of using respondent-driven sampling (RDS) in the survey. Based on results from formative research, a RDS survey was designed and conducted to collect demographic, behavioral and serologic data. RDSAT was used to calculate point estimation and confidence intervals. SPSS was used for bi-variate analysis using RDSAT exported weighed data. NETDRAW was used to draw network diagram. Among 617 subjects recruited, the adjusted HIV and syphilis prevalence rates were 16.8% and 10.9%, respectively. 73.0% of the subjects were 20 to 29 years old and 72.9% were officially registered residents of Chongqing. 83.4% were single, with the proportion of students the highest, accounting for 24.6%. During the last six months, 83.4% of them reported ever having anal sex, and 54.0% reported having unprotected anal sex. This survey confirmed that Chongqing had a higher reported HIV prevalence among MSM than from other Chinese cities. Comprehensive intervention services were required to address this alarmingly high prevalence, with focus on intervention through internet and those having syphilis infection. RDS seemed one of the effective ways of recruiting hidden MSM populations in Chongqing which had a large population of active MSM who did not frequently visit MSM venues as compared with snowball method.

Social networks of men who have sex with men and their implications for HIV/STI interventions: results from a cross-sectional study using respondent-driven sampling in a large and a small city in Tanzania.

PubMed

Ross, Michael W; Larsson, Markus; Jacobson, Jerry; Nyoni, Joyce; Agardh, Anette

2016-11-18

Men who have sex with men (MSM) in sub-Saharan Africa remain hidden and hard to reach for involvement in HIV and sexually transmitted infection (STI) services. The aim of the current study was to describe MSM social networks in a large and a small Tanzanian city in order to explore their utility for peer-based healthcare interventions. Data were collected through respondent-driven sampling (RDS) in Dar es Salaam (n=197) and in Tanga (n=99) in 2012 and 2013, using 5 and 4 seeds, respectively. All results were adjusted for RDS sampling design. Mean personal network size based on the number of MSM who were reported by the participants, as known to them was 12.0±15.5 in Dar es Salaam and 7.6±8.1 in Tanga. Mean actual RDS network size was 39.4±31.4 in Dar es Salaam and 25.3±9.7 in Tanga. A majority (97%) reported that the person from whom they received the recruitment coupon was a sexual partner, close friend or acquaintance. Homophile in recruitment patterns (selective affiliation) was present for age, gay openness, and HIV status in Dar es Salaam, and for sexual identification in Tanga. The personal network sizes and existence of contacts between recruiter and referral indicate that it is possible to use peer-driven interventions to reach MSM for HIV/STI interventions in larger and smaller sub-Saharan African cities. The study was reviewed and approved by the University of Texas Health Science Center's Institutional Review Board (HSC-SPH-10-0033) and the Tanzanian National Institute for Medical Research (NIMR/HQ/R.8a/Vol. IX/1088). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Social network-based recruitment successfully reveals HIV-1 transmission networks among high-risk individuals in El Salvador.

PubMed

Dennis, Ann M; Murillo, Wendy; de Maria Hernandez, Flor; Guardado, Maria Elena; Nieto, Ana Isabel; Lorenzana de Rivera, Ivette; Eron, Joseph J; Paz-Bailey, Gabriela

2013-05-01

HIV in Central America is concentrated among certain groups such as men who have sex with men (MSM) and female sex workers (FSWs). We compared social recruitment chains and HIV transmission clusters from 699 MSM and 787 FSWs to better understand factors contributing to ongoing HIV transmission in El Salvador. Phylogenies were reconstructed using pol sequences from 119 HIV-positive individuals recruited by respondent-driven sampling (RDS) and compared with RDS chains in 3 cities in El Salvador. Transmission clusters with a mean pairwise genetic distance ≤ 0.015 and Bayesian posterior probabilities =1 were identified. Factors associated with cluster membership were evaluated among MSM. Sequences from 34 (43%) MSM and 4 (10%) FSW grouped in 14 transmission clusters. Clusters were defined by risk group (12 MSM clusters) and geographic residence (only 1 spanned separate cities). In 4 MSM clusters (all n = 2), individuals were also members of the same RDS chain, but only 2 had members directly linked through recruitment. All large clusters (n ≥ 3) spanned >1 RDS chain. Among MSM, factors independently associated with cluster membership included recent infection by BED assay (P = 0.02), sex with stable male partners (P = 0.02), and sex with ≥ 3 male partners in the past year (P = 0.04). We found few HIV transmissions corresponding directly with the social recruitment. However, we identified clustering in nearly one-half of MSM suggesting that RDS recruitment was indirectly but successfully uncovering transmission networks, particularly among recent infections. Interrogating RDS chains with phylogenetic analyses may help refine methods for identifying transmission clusters.

Community mapping and respondent-driven sampling of gay and bisexual men’s communities in Vancouver, Canada

PubMed Central

Forrest, Jamie I; Stevenson, Benjamin; Rich, Ashleigh; Michelow, Warren; Pai, Jayaram; Jollimore, Jody; Raymond, H. Fisher; Moore, David; Hogg, Robert S; Roth, Eric A

2014-01-01

Literature suggests formative research is vital for those using respondent-driven sampling (RDS) to study hidden populations of interest. However, few authors have described in detail how different qualitative methodologies can address the objectives of formative research for understanding the social network properties of the study population, selecting seeds, and adapting survey logistics to best fit the population. In this paper we describe the use of community mapping exercises as a tool within focus groups to collect data on social and sexual network characteristics of gay and bisexual men in the metropolitan area of Vancouver, Canada. Three key themes emerged from analyzing community maps along with other formative research data: (a) connections between physical spaces and social networks of gay and bisexual men, (b) diversity in communities, and (c) substance use connected with formation of sub-communities. We discuss how these themes informed the planning and operations of a longitudinal epidemiological cohort study recruited by RDS. We argue that using community mapping within formative research is a valuable qualitative tool for characterizing network structures of a diverse and differentiated population of gay and bisexual men in a highly developed urban setting. PMID:24512070

Share2Quit: Web-Based Peer-Driven Referrals for Smoking Cessation

PubMed Central

2013-01-01

Background Smoking is the number one preventable cause of death in the United States. Effective Web-assisted tobacco interventions are often underutilized and require new and innovative engagement approaches. Web-based peer-driven chain referrals successfully used outside health care have the potential for increasing the reach of Internet interventions. Objective The objective of our study was to describe the protocol for the development and testing of proactive Web-based chain-referral tools for increasing the access to Decide2Quit.org, a Web-assisted tobacco intervention system. Methods We will build and refine proactive chain-referral tools, including email and Facebook referrals. In addition, we will implement respondent-driven sampling (RDS), a controlled chain-referral sampling technique designed to remove inherent biases in chain referrals and obtain a representative sample. We will begin our chain referrals with an initial recruitment of former and current smokers as seeds (initial participants) who will be trained to refer current smokers from their social network using the developed tools. In turn, these newly referred smokers will also be provided the tools to refer other smokers from their social networks. We will model predictors of referral success using sample weights from the RDS to estimate the success of the system in the targeted population. Results This protocol describes the evaluation of proactive Web-based chain-referral tools, which can be used in tobacco interventions to increase the access to hard-to-reach populations, for promoting smoking cessation. Conclusions Share2Quit represents an innovative advancement by capitalizing on naturally occurring technology trends to recruit smokers to Web-assisted tobacco interventions. PMID:24067329

A Translational Approach to Validate in Vivo Anti-tumor Effects of Chloroquine on Breast Cancer Risk

DTIC Science & Technology

2014-05-01

performed at one month post- activation to ensure appropriate accruals with the sampling method, Respondent Driven Sampling (RDS), was encouraging...Add another country/ year of service *Repeat these questions as many times as the RPCV has tours of service. Are you currently active duty...chains.  Interim  analyses  were  performed  at  one  and  two  months  post-­‐ activation  to  ensure  appropriate

Network Sampling with Memory: A proposal for more efficient sampling from social networks.

PubMed

Mouw, Ted; Verdery, Ashton M

2012-08-01

Techniques for sampling from networks have grown into an important area of research across several fields. For sociologists, the possibility of sampling from a network is appealing for two reasons: (1) A network sample can yield substantively interesting data about network structures and social interactions, and (2) it is useful in situations where study populations are difficult or impossible to survey with traditional sampling approaches because of the lack of a sampling frame. Despite its appeal, methodological concerns about the precision and accuracy of network-based sampling methods remain. In particular, recent research has shown that sampling from a network using a random walk based approach such as Respondent Driven Sampling (RDS) can result in high design effects (DE)-the ratio of the sampling variance to the sampling variance of simple random sampling (SRS). A high design effect means that more cases must be collected to achieve the same level of precision as SRS. In this paper we propose an alternative strategy, Network Sampling with Memory (NSM), which collects network data from respondents in order to reduce design effects and, correspondingly, the number of interviews needed to achieve a given level of statistical power. NSM combines a "List" mode, where all individuals on the revealed network list are sampled with the same cumulative probability, with a "Search" mode, which gives priority to bridge nodes connecting the current sample to unexplored parts of the network. We test the relative efficiency of NSM compared to RDS and SRS on 162 school and university networks from Add Health and Facebook that range in size from 110 to 16,278 nodes. The results show that the average design effect for NSM on these 162 networks is 1.16, which is very close to the efficiency of a simple random sample (DE=1), and 98.5% lower than the average DE we observed for RDS.

Network Sampling with Memory: A proposal for more efficient sampling from social networks

PubMed Central

Mouw, Ted; Verdery, Ashton M.

2013-01-01

Techniques for sampling from networks have grown into an important area of research across several fields. For sociologists, the possibility of sampling from a network is appealing for two reasons: (1) A network sample can yield substantively interesting data about network structures and social interactions, and (2) it is useful in situations where study populations are difficult or impossible to survey with traditional sampling approaches because of the lack of a sampling frame. Despite its appeal, methodological concerns about the precision and accuracy of network-based sampling methods remain. In particular, recent research has shown that sampling from a network using a random walk based approach such as Respondent Driven Sampling (RDS) can result in high design effects (DE)—the ratio of the sampling variance to the sampling variance of simple random sampling (SRS). A high design effect means that more cases must be collected to achieve the same level of precision as SRS. In this paper we propose an alternative strategy, Network Sampling with Memory (NSM), which collects network data from respondents in order to reduce design effects and, correspondingly, the number of interviews needed to achieve a given level of statistical power. NSM combines a “List” mode, where all individuals on the revealed network list are sampled with the same cumulative probability, with a “Search” mode, which gives priority to bridge nodes connecting the current sample to unexplored parts of the network. We test the relative efficiency of NSM compared to RDS and SRS on 162 school and university networks from Add Health and Facebook that range in size from 110 to 16,278 nodes. The results show that the average design effect for NSM on these 162 networks is 1.16, which is very close to the efficiency of a simple random sample (DE=1), and 98.5% lower than the average DE we observed for RDS. PMID:24159246

Intravenous heroin use in Haiphong, Vietnam: Need for comprehensive care including methamphetamine use-related interventions.

PubMed

Michel, Laurent; Des Jarlais, Don C; Duong Thi, Huong; Khuat Thi Hai, Oanh; Pham Minh, Khuê; Peries, Marianne; Vallo, Roselyne; Nham Thi Tuyet, Thanh; Hoang Thi, Giang; Le Sao, Mai; Feelemyer, Jonathan; Vu Hai, Vinh; Moles, Jean-Pierre; Laureillard, Didier; Nagot, Nicolas

2017-10-01

The aim of this study was to describe patterns among people who inject drugs (PWID), risk-related behaviours and access to methadone treatment, in order to design a large-scale intervention aiming to end the HIV epidemic in Haiphong, Vietnam. A respondent-driven sampling (RDS) survey was first conducted to identify profiles of drug use and HIV risk-related behaviour among PWID. A sample of PWID was then included in a one-year cohort study to describe access to methadone treatment and associated factors. Among the 603 patients enrolled in the RDS survey, 10% were female, all were injecting heroin and 24% were using methamphetamine, including 3 (0.5%) through injection. Different profiles of risk-related behaviours were identified, including one entailing high-risk sexual behaviour (n=37) and another involving drug-related high-risk practices (n=22). High-risk sexual activity was related to binge drinking and methamphetamine use. Among subjects with low sexual risk, sexual intercourse with a main partner with unknown serostatus was often unprotected. Among the 250 PWID included in the cohort, 55.2% initiated methadone treatment during the follow-up (versus 4.4% at RDS); methamphetamine use significantly increased. The factors associated with not being treated with methadone after 52 weeks were fewer injections per month and being a methamphetamine user at RDS. Heroin is still the main drug injected in Haiphong. Methamphetamine use is increasing markedly and is associated with delay in methadone initiation. Drug-related risks are low but sexual risk behaviours are still present. Comprehensive approaches are needed in the short term. Copyright © 2017 Elsevier B.V. All rights reserved.

HIV, HCV, HBV, and syphilis among transgender women from Brazil

PubMed Central

Bastos, Francisco I.; Bastos, Leonardo Soares; Coutinho, Carolina; Toledo, Lidiane; Mota, Jurema Corrêa; Velasco-de-Castro, Carlos Augusto; Sperandei, Sandro; Brignol, Sandra; Travassos, Tamiris Severino; dos Santos, Camila Mattos; Malta, Monica Siqueira

2018-01-01

Abstract Different sampling strategies, analytic alternatives, and estimators have been proposed to better assess the characteristics of different hard-to-reach populations and their respective infection rates (as well as their sociodemographic characteristics, associated harms, and needs) in the context of studies based on respondent-driven sampling (RDS). Despite several methodological advances and hundreds of empirical studies implemented worldwide, some inchoate findings and methodological challenges remain. The in-depth assessment of the local structure of networks and the performance of the available estimators are particularly relevant when the target populations are sparse and highly stigmatized. In such populations, bottlenecks as well as other sources of biases (for instance, due to homophily and/or too sparse or fragmented groups of individuals) may be frequent, affecting the estimates. In the present study, data were derived from a cross-sectional, multicity RDS study, carried out in 12 Brazilian cities with transgender women (TGW). Overall, infection rates for HIV and syphilis were very high, with some variation between different cities. Notwithstanding, findings are of great concern, considering the fact that female TGW are not only very hard-to-reach but also face deeply-entrenched prejudice and have been out of the reach of most therapeutic and preventive programs and projects. We cross-compared findings adjusted using 2 estimators (the classic estimator usually known as estimator II, originally proposed by Volz and Heckathorn) and a brand new strategy to adjust data generated by RDS, partially based on Bayesian statistics, called for the sake of this paper, the RDS-B estimator. Adjusted prevalence was cross-compared with estimates generated by non-weighted analyses, using what has been called by us a naïve estimator or rough estimates. PMID:29794601

HIV, HCV, HBV, and syphilis among transgender women from Brazil: Assessing different methods to adjust infection rates of a hard-to-reach, sparse population.

PubMed

Bastos, Francisco I; Bastos, Leonardo Soares; Coutinho, Carolina; Toledo, Lidiane; Mota, Jurema Corrêa; Velasco-de-Castro, Carlos Augusto; Sperandei, Sandro; Brignol, Sandra; Travassos, Tamiris Severino; Dos Santos, Camila Mattos; Malta, Monica Siqueira

2018-05-01

Different sampling strategies, analytic alternatives, and estimators have been proposed to better assess the characteristics of different hard-to-reach populations and their respective infection rates (as well as their sociodemographic characteristics, associated harms, and needs) in the context of studies based on respondent-driven sampling (RDS). Despite several methodological advances and hundreds of empirical studies implemented worldwide, some inchoate findings and methodological challenges remain. The in-depth assessment of the local structure of networks and the performance of the available estimators are particularly relevant when the target populations are sparse and highly stigmatized. In such populations, bottlenecks as well as other sources of biases (for instance, due to homophily and/or too sparse or fragmented groups of individuals) may be frequent, affecting the estimates.In the present study, data were derived from a cross-sectional, multicity RDS study, carried out in 12 Brazilian cities with transgender women (TGW). Overall, infection rates for HIV and syphilis were very high, with some variation between different cities. Notwithstanding, findings are of great concern, considering the fact that female TGW are not only very hard-to-reach but also face deeply-entrenched prejudice and have been out of the reach of most therapeutic and preventive programs and projects.We cross-compared findings adjusted using 2 estimators (the classic estimator usually known as estimator II, originally proposed by Volz and Heckathorn) and a brand new strategy to adjust data generated by RDS, partially based on Bayesian statistics, called for the sake of this paper, the RDS-B estimator. Adjusted prevalence was cross-compared with estimates generated by non-weighted analyses, using what has been called by us a naïve estimator or rough estimates.

Central and East European migrant men who have sex with men in London: a comparison of recruitment methods.

PubMed

Evans, Alison R; Hart, Graham J; Mole, Richard; Mercer, Catherine H; Parutis, Violetta; Gerry, Christopher J; Imrie, John; Burns, Fiona M

2011-05-17

Following the expansion of the European Union, there has been a large influx of Central and East European (CEE) migrants to the UK. CEE men who have sex with men (MSM) represent a small minority within this population that are none-the-less important to capture in sexual health research among the CEE migrant community. This paper examines the feasibility of recruiting CEE MSM for a survey of sexual behaviour in London using respondent driven sampling (RDS), via gay websites and in GUM clinics. We sought CEE MSM to start RDS chain referral among GUM clinic attendees, our personal contacts and at gay events and venues in central London. We recruited CEE MSM (n = 485) via two popular websites for gay men in Britain (March-May 2009) and at two central London GUM clinics (n = 51) (July 2008-March 2009). We found seventeen men who knew other CEE MSM in London and agreed to recruit contacts into the study. These men recruited only three men into the study, none of whom recruited any further respondents, and RDS was abandoned after 7 months (July 2008-January 2009). Half of the men that we approached to participate in RDS did not know any other CEE MSM in London. Men who agreed to recruit contacts for RDS were rather more likely to have been in the UK for more than one year (94.1% vs 70.0%, p = 0.052). Men recruited through gay websites and from GUM clinics were similar. The Internet was the most successful method for collecting data on sexual risk behaviour among CEE MSM in London. CEE MSM in London were not well networked. RDS may also have failed because they did not fully understand the procedure and/or the financial incentive was not sufficient motivation to take part.

How much of the cocaine market are we missing? Insights from respondent-driven sampling in a mid-sized American city.

PubMed

Caulkins, Jonathan P; Sussell, Jesse; Kilmer, Beau; Kasunic, Anna

2015-02-01

Studying markets for illegal drugs is important, but difficult. Data usually come from a selected subset of consumers, such as arrestees, treatment clients, or household survey respondents. There are rarely opportunities to study how such groups may differ from other market participants or how much of total consumption they represent. This paper uses respondent-driven sampling (RDS) of drug users in a mid-sized American city to estimate the shares of cocaine (powder and crack) users and expenditures that are attributable to different combinations of these groups. We find that those arrested in the last year accounted for 34% of past-month cocaine users and 40% of past-week cocaine spending in the RDS sample. Augmenting past-year arrestees with those who received treatment in the past year increases these values to 44% (users) and 55% (spending). Our results suggest that estimates based only on people who were arrested and/or treated in the past year would have to be inflated by 100-200% to capture the market totals. Adding those who own or rent their place of residence increased coverage in this study to 76% (users) and 81% (spending), suggesting that in theory the inflation factor could be reduced to 23-32% by supplementing data on arrestees and treatment populations with household data, although in practice rates of under-reporting by survey respondents may make coverage (sampling frame) a secondary concern for household surveys. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

HIV Prevalence and Risk Factors Among Male Foreign Migrants in Cape Town, South Africa

PubMed Central

Townsend, Loraine; Zembe, Yanga; Cheyip, Mireille; Guttmacher, Sally; Carter, Rebecca; Mathews, Cathy

2018-01-01

While migration has been shown to be a risk factor for HIV, variation in HIV prevalence by subgroups of migrants needs further exploration. This paper documents the HIV prevalence and key characteristics among male foreign migrants in Cape Town, South Africa and the effectiveness of respondent-driven sampling (RDS) to recruit this population. Participants in this cross-sectional study completed a behavioral risk-factor questionnaire and provided a dried blood sample for HIV analysis. Overall HIV prevalence was estimated to be 8.7 % (CI 5.4–11.8) but varied dramatically by country of origin. After adjusting for country of origin, HIV sero-positivity was positively associated with older age (p = 0.001), completing high school (p = 0.025), not having enough money for food (p = 0.036), alcohol use (p = 0.049), and engaging in transactional sex (p = 0.022). RDS was successful in recruiting foreign migrant men. A better understanding of the timing of HIV acquisition is needed to design targeted interventions for migrant men. PMID:24781639

Respondent-driven sampling for identification of HIV- and HCV-infected people who inject drugs and men who have sex with men in India: A cross-sectional, community-based analysis.

PubMed

Solomon, Sunil S; McFall, Allison M; Lucas, Gregory M; Srikrishnan, Aylur K; Kumar, Muniratnam S; Anand, Santhanam; Quinn, Thomas C; Celentano, David D; Mehta, Shruti H

2017-11-01

A major barrier to achieving ambitious targets for global control of HIV and hepatitis C virus (HCV) is low levels of awareness of infection among key populations such as men who have sex with men (MSM) and people who inject drugs (PWID). We explored the potential of a strategy routinely used for surveillance in these groups, respondent-driven sampling (RDS), to be used as an intervention to identify HIV- and HCV-infected PWID and MSM who are unaware of their status and those who are viremic across 26 Indian cities at various epidemic stages. Data were collected as part of the baseline assessment of an ongoing cluster-randomized trial. RDS was used to accrue participants at 27 sites (15 PWID sites and 12 MSM sites) selected to reflect varying stages of the HIV epidemic among MSM and PWID in India. A total of 56 seeds recruited a sample of 26,447 persons (approximately 1,000 participants per site) between October 1, 2012, and December 19, 2013. Across MSM sites (n = 11,997), the median age was 25 years and the median number of lifetime male partners was 8. Across PWID sites (n = 14,450), 92.4% were male, the median age was 30 years, and 87.5% reported injection in the prior 6 months. RDS identified 4,051 HIV-infected persons, of whom 2,325 (57.4%) were unaware of their HIV infection and 2,816 (69.5%) were HIV viremic. It also identified 5,777 HCV-infected persons, of whom 5,337 (92.4%) were unaware that they were infected with HCV and 4,728 (81.8%) were viremic. In the overall sample (both MSM and PWID), the prevalence of HIV-infected persons who were unaware of their status increased with sampling depth, from 7.9% in participants recruited in waves 1 through 5 to 12.8% among those recruited in waves 26 and above (p-value for trend < 0.001). The overall detection rate of people unaware of their HIV infection was 0.5 persons per day, and the detection rate of HIV-infected persons with viremia (regardless of their awareness status) was 0.7 per day. The detection rate of HIV viremic individuals was positively associated with underlying HIV prevalence and the prevalence of HIV viremia (linear regression coefficient per 1-percentage-point increase in prevalence: 0.05 and 0.07, respectively). The median detection rate of PWID who were unaware of their HCV infection was 2.5 per day. The cost of identifying 1 unaware HIV-infected individual ranged from US$51 to US$2,072 across PWID sites and from US$189 to US$5,367 across MSM sites. The mean additional cost of identifying 1 unaware HCV-infected PWID was US$13 (site range: US$7-US$140). Limitations of the study include the exclusivity of study sites to India, lack of prior HIV/HCV diagnosis confirmation with clinic records, and lack of cost data from other case-finding approaches commonly used in India. In this study, RDS was able to rapidly identify at nominal cost a substantial number of unaware and viremic HIV-infected and HCV-infected individuals who were currently not being reached by existing programs and who were at high risk for transmission. Combining RDS (or other network-driven recruitment approaches) with strategies focused on linkage to care, particularly in high-burden settings, may be a viable option for achieving the 90-90-90 targets in key populations in resource-limited settings.

Diverse HIV epidemics among people who inject drugs in Thailand: evidence from respondent-driven sampling surveys in Bangkok and Chiang Mai.

PubMed

Prybylski, Dimitri; Manopaiboon, Chomnad; Visavakum, Prin; Yongvanitjit, Kovit; Aramrattana, Apinun; Manomaipiboon, Parnrudee; Tanpradech, Suvimon; Suksripanich, Orapin; Pattanasin, Sarika; Wolfe, Mitchell; Whitehead, Sara J

2015-03-01

Thailand's long-standing HIV sero-sentinel surveillance system for people who inject drugs (PWID) is confined to those in methadone-based drug treatment clinics and representative data are scarce, especially outside of Bangkok. We conducted probability-based respondent-driven sampling (RDS) surveys in Bangkok (n=738) and Chiang Mai (n=309) to increase understanding of local HIV epidemics and to better inform the planning of evidence-based interventions. PWID had different epidemiological profiles in these two cities. Overall HIV prevalence was higher in Bangkok (23.6% vs. 10.9%, p<0.001) but PWID in Bangkok are older and appear to have long-standing HIV infections. In Chiang Mai, HIV infections appear to be more recently acquired and PWID were younger and had higher levels of recent injecting and sexual risk behaviors with lower levels of intervention exposure. Methamphetamine was the predominant drug injected in both sites and polydrug use was common although levels and patterns of the specific drugs injected varied significantly between the sites. In multivariate analysis, recent midazolam injection was significantly associated with HIV infection in Chiang Mai (adjusted odds ratio=8.1; 95% confidence interval: 1.2-54.5) whereas in Bangkok HIV status was not associated with recent risk behaviors as infections had likely been acquired in the past. PWID epidemics in Thailand are heterogeneous and driven by local factors. There is a need to customize intervention strategies for PWID in different settings and to integrate population-based survey methods such as RDS into routine surveillance to monitor the national response. Published by Elsevier Ireland Ltd.

Diverse HIV epidemics among people who inject drugs in Thailand: Evidence from respondent-driven sampling surveys in Bangkok and Chiang Mai☆

PubMed Central

Prybylski, Dimitri; Manopaiboon, Chomnad; Visavakum, Prin; Yongvanitjit, Kovit; Aramrattana, Apinun; Manomaipiboon, Parnrudee; Tanpradech, Suvimon; Suksripanich, Orapin; Pattanasin, Sarika; Wolfe, Mitchell; Whitehead, Sara J.

2016-01-01

Background Thailand’s long-standing HIV sero-sentinel surveillance system for people who inject drugs (PWID) is confined to those in methadone-based drug treatment clinics and representative data are scarce, especially outside of Bangkok. Methods We conducted probability-based respondent-driven sampling (RDS) surveys in Bangkok (n = 738) and Chiang Mai (n = 309) to increase understanding of local HIV epidemics and to better inform the planning of evidence-based interventions. Results PWID had different epidemiological profiles in these two cities. Overall HIV prevalence was higher in Bangkok (23.6% vs. 10.9%, p < 0.001) but PWID in Bangkok are older and appear to have long-standing HIV infections. In Chiang Mai, HIV infections appear to be more recently acquired and PWID were younger and had higher levels of recent injecting and sexual risk behaviors with lower levels of intervention exposure. Methamphetamine was the predominant drug injected in both sites and polydrug use was common although levels and patterns of the specific drugs injected varied significantly between the sites. In multivariate analysis, recent midazolam injection was significantly associated with HIV infection in Chiang Mai (adjusted odds ratio = 8.1; 95% confidence interval: 1.2–54.5) whereas in Bangkok HIV status was not associated with recent risk behaviors as infections had likely been acquired in the past. Conclusion PWID epidemics in Thailand are heterogeneous and driven by local factors. There is a need to customize intervention strategies for PWID in different settings and to integrate population-based survey methods such as RDS into routine surveillance to monitor the national response. PMID:25640153

Intimate Partner Violence and HIV Sexual Risk Behaviour Among Women Who Inject Drugs in Indonesia: A Respondent-Driven Sampling Study.

PubMed

Stoicescu, Claudia; Cluver, Lucie D; Spreckelsen, Thees; Casale, Marisa; Sudewo, Anindita Gabriella; Irwanto

2018-06-11

Women who inject drugs are disproportionately affected by HIV and intimate partner violence (IPV); however, the link between IPV and HIV remains under-researched among substance-using women in low- and middle-income countries. This study examined associations and additive effects of different forms of IPV victimization (psychological, physical and/or injurious, and sexual) on HIV sexual risk behavior among women who inject drugs in Indonesia. Respondent-driven sampling (RDS) was used to recruit 731 women from Greater Jakarta and Bandung, West Java. RDS-II weighted prevalence of any past-year IPV was 68.9% (95% CI 65.0, 72.6) in Jakarta and 55.9% (95% CI 48.0, 63.5) in Bandung. In separate logistic regressions controlling for socio-demographic covariates, all three forms of IPV showed statistically significant associations with sexual risk behavior. After adjusting for all IPV types, psychological (OR 1.87; 95% CI 1.17, 2.99; p = 0.009) and sexual (OR 1.98; 95% CI 1.22, 3.21; p = 0.006) IPV independently predicted women's sexual risk behavior. Marginal effects models suggested that co-occurrence of multiple forms of IPV had greater adverse consequences: sexual risk behavior was reported by 64.1% of women who did not experience any IPV, but increased to 89.9% among women exposed to all three types. Comprehensive harm reduction services that integrate IPV monitoring and prevention are urgently needed to reduce both HIV and IPV.

Optical characterization of thin nickel films on polymer substrates using reflectance difference spectroscopy

NASA Astrophysics Data System (ADS)

Rinnerbauer, V.; Schmidegg, K.; Hohage, M.; Sun, L. D.; Flores-Camacho, J. M.; Zeppenfeld, P.

2009-06-01

We have used reflectance difference spectroscopy (RDS) and its extension, azimuth-dependent RDS (ADRDS), to study the properties of sputtered and evaporated nickel films on biaxially oriented poly(ethylene terephtalate) (PET) films in a roll to roll web-coating process. From the full set of ADRDS spectra we extract and analyze both the intrinsic RDS spectra and the azimuthal orientation of the effective optical anisotropy of the samples. From the latter, contributions to the RDS spectra arising from the nickel layer and the PET substrate with different orientations of the optical eigenaxes can be inferred. We find an attenuation of the characteristic RDS signal of the PET substrate with increasing nickel film thickness which is in good agreement with the theoretical prediction. For film thicknesses above 20 nm another contribution to the RDS signal attributed to the optical anisotropy of the deposited nickel layers can be observed. Its strength depends on the deposition method, and is considerably larger for evaporated films than for sputtered ones. With increasing nickel film thickness, the azimuthal orientation of the sample anisotropy changes from the initial value of the PET substrate by about 20° toward the machine direction of the foil. We demonstrate that RDS is also a valuable tool for inline monitoring in the roll to roll process, as the attenuation of the RDS signal, under proper consideration of the orientation of the effective anisotropy, is a function of the film thickness and characteristic for the deposited material.

Heavy metal contents of road-deposited sediment along the urban-rural gradient around Beijing and its potential contribution to runoff pollution.

PubMed

Zhao, Hongtao; Li, Xuyong; Wang, Xiaomei

2011-09-01

Understanding the contribution of road-deposited sediment (RDS) and its washoff process is essential for controlling urban runoff pollution. Ninety-seven RDS samples were collected along the urban-suburban-rural gradient from areas of five administrative units in the Beijing metropolitan region, including central urban (UCA), urban village (UVA), central suburban county (CSA), rural town (RTA), and rural village (RVA) areas. RDS washoff was evaluated with different particle sizes using a rainfall simulator. Heavy metal elements (i.e., Cr, Cu, Ni, Pb, and Zn) were estimated in both RDS and runoff samples. The RDS mass per unit area increased in the order UCA (21 ± 24 g/m(2)) ≈ CSA (20 ± 16 g/m(2)) < RTA (59 ± 63 g/m(2)) < RVA (147 ± 112 g/m(2)) ≈ UVA (147 ± 198 g/m(2)). Compared to RDS from the other administrative units, RDS from the UCA and CSA had higher metal concentrations and higher proportions of smaller particles, whereas that from the RVA and UVA had larger quantities of metals per unit area. UCA and CSA had lower potential runoff pollution contributions per unit area. Our findings imply that controlling the first flush in the UCA and CSA, and improving existing street cleaning methods and road surface conditions in the TRA, UVA, and RVA will be appropriate strategies for controlling runoff pollution from RDS.

Ethical considerations in investigating youth alcohol norms and behaviours: a case for mature minor consent.

PubMed

Hildebrand, J; Maycock, B; Comfort, J; Burns, S; Adams, E; Howat, P

2015-12-01

Mature minor consent only became available in Australia in 2007. There is neither an explicitly defined protocol, nor a clear definition evident in the literature relating to use of the mature minor concept in health research. Due to difficulties in defining fixed age ranges to varying levels of maturity and vulnerability, there is a lack of clarity surrounding when it might be reasonable and ethical to apply for or grant a waiver for parental consent. This paper describes the challenges faced and solutions created when gaining approval for use of mature minor consent in a respondent-driven sampling (RDS) study to explore the social norms and alcohol consumption among 14-17-year-old adolescents (n = 1012) in the community. The University's Human Research Ethics Committee granted mature minor consent for this study, and the techniques applied enabled recruitment of adolescents from community-based settings through use of RDS to achieve the required sample. This paper has relevance for research that requires a waiver for parental consent; it presents a case study for assessing mature minors and makes recommendations on how ethical guidelines can be improved to assist human research ethics application processes.

HIV Prevalence and Awareness of Positive Serostatus Among Men Who Have Sex With Men and Transgender Women in Bogotá, Colombia

PubMed Central

Reisen, Carol A.; María del Río-González, Ana; Bianchi, Fernanda T.; Ramirez-Valles, Jesus; Poppen, Paul J.

2015-01-01

Objectives. We estimated HIV prevalence among men who have sex with men (MSM) and transgender women in Bogotá, Colombia, and explored differences between HIV-positive individuals who are aware and unaware of their serostatus. Methods. In this cross-sectional 2011 study, we used respondent-driven sampling (RDS) to recruit 1000 MSM and transgender women, who completed a computerized questionnaire and received an HIV test. Results. The RDS-adjusted prevalence was 12.1% (95% confidence interval [CI] = 8.7, 15.8), comparable to a previous RDS-derived estimate. Among HIV-positive participants, 39.7% (95% CI = 25.0, 54.8) were aware of their serostatus and 60.3% (95% CI = 45.2, 75.5) were unaware before this study. HIV-positive–unaware individuals were more likely to report inadequate insurance coverage, exchange sex (i.e., sexual intercourse in exchange for money, goods, or services), and substance use than other participants. HIV-positive–aware participants were least likely to have had condomless anal intercourse in the previous 3 months. Regardless of awareness, HIV-positive participants reported more violence and forced relocation experiences than HIV-negative participants. Conclusions. There is an urgent need to increase HIV detection among MSM and transgender women in Bogotá. HIV-positive–unaware group characteristics suggest an important role for structural, social, and individual interventions. PMID:25602899

Hepatitis C virus infection among drug injectors in St Petersburg, Russia: social and molecular epidemiology of an endemic infection.

PubMed

Paintsil, Elijah; Verevochkin, Sergei V; Dukhovlinova, Elena; Niccolai, Linda; Barbour, Russell; White, Edward; Toussova, Olga V; Alexander, Louis; Kozlov, Andrei P; Heimer, Robert

2009-11-01

To understand the epidemiology and transmission patterns of hepatitis C virus (HCV), the predominant blood borne-pathogen infecting injection drug users (IDUs), in a part of the former Soviet Union. Cross-sectional respondent-driven sample of IDUs. St Petersburg, Russia. A total of 387 IDUs were recruited in late 2005 and throughout 2006. Participants were surveyed to collect demographic, medical and both general and dyad-specific drug injection and sexual behaviors. A blood sample was collected to detect antibodies to hepatitis C and to amplify viral RNA for molecular analysis. The molecular data, including genotypes, were analyzed spatially and linkage patterns were compared to the social linkages obtained by respondent-driven sampling (RDS) for chains of respondents and among the injection dyads. HCV infection was all but ubiquitous: 94.6% of IDUs were HCV-seropositive. Among the 209 viral sequences amplified, genotype 3a predominated (n = 119, 56.9%), followed by 1b (n = 61, 29.2%) and 1a (n = 25, 11.9%). There was no significant clustering of genotypes spatially. Neither genotypes nor closely related sequences were clustered within RDS chains. Analysis of HCV sequences from dyads failed to find associations of genotype or sequence homology within pairs. Genotyping reveals that there have been at least five unique introductions of HCV genotypes into the IDU community in St Petersburg. Analysis of prevalent infections does not appear to correlate with the social networks of IDUs, suggesting that simple approaches to link these networks to prevalent infections, rather than incident transmission, will not prove meaningful. On a more positive note, the majority of IDUs are infected with 3a genotype that is associated with sustained virological response to antiviral therapy.

The use of respondent-driven sampling to assess malaria knowledge, treatment-seeking behaviours and preventive practices among mobile and migrant populations in a setting of artemisinin resistance in Western Cambodia.

PubMed

Ly, Po; Thwing, Julie; McGinn, Colleen; Quintero, Cesia E; Top-Samphor, Narann; Habib, Najibullah; Richards, Jack S; Canavati, Sara E; Vinjamuri, Seshu Babu; Nguon, Chea

2017-09-19

Multi-drug-resistant Plasmodium falciparum threatens malaria elimination efforts in Cambodia and the Greater Mekong Subregion (GMS). Malaria burden in the GMS is higher among certain high-risk demographic groups in Cambodia, especially among migrant and mobile populations (MMPs). This respondent driven sampling (RDS) study was conducted in order to determine malaria knowledge, treatment-seeking behaviours and preventive practices among two MMP groups in Western Cambodia. An RDS survey of MMPs was implemented in four purposively-selected communes along the Thai-Cambodia border; two in Veal Veang District and two in Pailin Province, chosen due to their sizeable MMP groups, their convenience of access, and their proximity to Thailand, which allowed for comparison with RDS studies in Thailand. There were 764 participants in Pailin Province and 737 in Veal Veang District. Health messages received in Veal Veang were most likely to come from billboards (76.5%) and family and friends (57.7%), while in Pailin they were most likely to come from sources like radio (57.1%) and television (31.3%). Knowledge of malaria transmission by mosquito and prevention by bed net was above 94% in both locations, but some misinformation regarding means of transmission and prevention methods existed, predominantly in Veal Veang. Ownership of treated bed nets was lower in Pailin than in Veal Veang (25.3% vs 53.2%), while reported use the night before the survey was higher in Pailin than in Veal Veang (57.1% vs 31.6%). Use of private sector health and pharmaceutical services was common, but 81.1% of patients treated for malaria in Pailin and 86.6% in Veal Veang had received a diagnostic test. Only 29.6% of patients treated in Pailin and 19.6% of those treated in Veal Veng reported receiving the indicated first-line treatment. Barriers in access to malaria prevention and case management were common among MMPs, with marked variation by site. Resolving both nation-wide and MMP-specific challenges will require targeted interventions that take into account this heterogeneity.

The use and correlates of illicit silicone or “fillers” in a population-based sample of transwomen, San Francisco, 2013

PubMed Central

Wilson, Erin; Rapues, Jenna; Jin, Harry; Raymond, H. Fisher

2014-01-01

Introduction There is a dearth of studies to quantify the use of illicit fillers by transwomen. Case studies of illicit filler injections have pointed to an array of serious health complications, including death. Aim The aim of this study was to determine the population prevalence of filler use among transwomen, and to identify correlations with filler use. Methods An analysis of data collected in 2013 with a population-based sample of 234 transwomen recruited using respondent driven sampling (RDS). We used RDS weights to conduct bivariate and multivariate analyses of correlates of filler use. Main Outcome measures Main outcome measures were an RDS-weighted population prevalence of filler use among transwomen and differences in demographic characteristics, transition-related care factors and self-esteem related to appearance. Results Weighted filler prevalence among transwomen was 16.7%. Being a transwomen between 30–49 years of age, owning/renting or living with a partner/family/friend, having had and planning to have surgery in the future and having used non-prescribed hormones were all associated with filler use. HIV was not associated with filler use. Conclusions This study provides the first known estimate to date of the prevalence of filler use in a population-based sample of transwomen in San Francisco. Accessing illicit fillers may be the only choice available for many transwomen due to the cost of legal surgeries and other procedures to change one’s appearance. An important next step in this research is to determine the overall prevalence and long-term consequences of filler use among transwomen, to explore how the use of fillers is protective to the safety and wellbeing of transwomen, and to find safe and affordable alternatives to this method that meets important gender-related appearance needs. PMID:24810672

Social networks of men who have sex with men: a study of recruitment chains using Respondent Driven Sampling in Salvador, Bahia State, Brazil.

PubMed

Brignol, Sandra Mara Silva; Dourado, Inês; Amorim, Leila Denise; Miranda, José Garcia Vivas; Kerr, Lígia R F S

2015-11-01

Social and sexual contact networks between men who have sex with men (MSM) play an important role in understanding the transmission of HIV and other sexually transmitted infections (STIs). In Salvador (Bahia State, Brazil), one of the cities in the survey Behavior, Attitudes, Practices, and Prevalence of HIV and Syphilis among Men Who Have Sex with Men in 10 Brazilian Cities, data were collected in 2008/2009 from a sample of 383 MSM using Respondent Driven Sampling (RDS). Network analysis was used to study friendship networks and sexual partner networks. The study also focused on the association between the number of links (degree) and the number of sexual partners, in addition to socio-demographic characteristics. The networks' structure potentially facilitates HIV transmission. However, the same networks can also be used to spread messages on STI/HIV prevention, since the proximity and similarity of MSM in these networks can encourage behavior change and positive attitudes towards prevention.

HIV prevalence among men who have sex with men in Brazil: results of the 2nd national survey using respondent-driven sampling.

PubMed

Kerr, Ligia; Kendall, Carl; Guimarães, Mark Drew Crosland; Salani Mota, Rosa; Veras, Maria Amélia; Dourado, Inês; Maria de Brito, Ana; Merchan-Hamann, Edgar; Pontes, Alexandre Kerr; Leal, Andréa Fachel; Knauth, Daniela; Castro, Ana Rita Coimbra Motta; Macena, Raimunda Hermelinda Maia; Lima, Luana Nepomuceno Costa; Oliveira, Lisangela Cristina; Cavalcantee, Maria do Socorro; Benzaken, Adele Schwartz; Pereira, Gerson; Pimenta, Cristina; Pascom, Ana Roberta Pati; Bermudez, Ximena Pamela Diaz; Moreira, Regina Célia; Brígido, Luis Fernando Macedo; Camillo, Ana Cláudia; McFarland, Willi; Johnston, Lisa G

2018-05-01

This paper reports human immuno-deficiency virus (HIV) prevalence in the 2nd National Biological and Behavioral Surveillance Survey (BBSS) among men who have sex with men (MSM) in 12 cities in Brazil using respondent-driven sampling (RDS).Following formative research, RDS was applied in 12 cities in the 5 macroregions of Brazil between June and December 2016 to recruit MSM for BBSS. The target sample size was 350 per city. Five to 6 seeds were initially selected to initiate recruitment and coupons and interviews were managed online. On-site rapid testing was used for HIV screening, and confirmed by a 2nd test. Participants were weighted using Gile estimator. Data from all 12 cities were merged and analyzed with Stata 14.0 complex survey data analysis tools in which each city was treated as its own strata. Missing data for those who did not test were imputed HIV+ if they reported testing positive before and were taking antiretroviral therapy.A total of 4176 men were recruited in the 12 cities. The average time to completion was 10.2 weeks. The longest chain length varied from 8 to 21 waves. The sample size was achieved in all but 2 cities.A total of 3958 of the 4176 respondents agreed to test for HIV (90.2%). For results without imputation, 17.5% (95%CI: 14.7-20.7) of our sample was HIV positive. With imputation, 18.4% (95%CI: 15.4-21.7) were seropositive.HIV prevalence increased beyond expectations from the results of the 2009 survey (12.1%; 95%CI: 10.0-14.5) to 18.4%; CI95%: 15.4 to 21.7 in 2016. This increase accompanies Brazil's focus on the treatment to prevention strategy, and a decrease in support for community-based organizations and community prevention programs.

HIV prevalence among men who have sex with men in Brazil: results of the 2nd national survey using respondent-driven sampling

PubMed Central

Kerr, Ligia; Kendall, Carl; Guimarães, Mark Drew Crosland; Salani Mota, Rosa; Veras, Maria Amélia; Dourado, Inês; Maria de Brito, Ana; Merchan-Hamann, Edgar; Pontes, Alexandre Kerr; Leal, Andréa Fachel; Knauth, Daniela; Castro, Ana Rita Coimbra Motta; Macena, Raimunda Hermelinda Maia; Lima, Luana Nepomuceno Costa; Oliveira, Lisangela Cristina; Cavalcantee, Maria do Socorro; Benzaken, Adele Schwartz; Pereira, Gerson; Pimenta, Cristina; Pascom, Ana Roberta Pati; Bermudez, Ximena Pamela Diaz; Moreira, Regina Célia; Brígido, Luis Fernando Macedo; Camillo, Ana Cláudia; McFarland, Willi; Johnston, Lisa G.

2018-01-01

Abstract This paper reports human immuno-deficiency virus (HIV) prevalence in the 2nd National Biological and Behavioral Surveillance Survey (BBSS) among men who have sex with men (MSM) in 12 cities in Brazil using respondent-driven sampling (RDS). Following formative research, RDS was applied in 12 cities in the 5 macroregions of Brazil between June and December 2016 to recruit MSM for BBSS. The target sample size was 350 per city. Five to 6 seeds were initially selected to initiate recruitment and coupons and interviews were managed online. On-site rapid testing was used for HIV screening, and confirmed by a 2nd test. Participants were weighted using Gile estimator. Data from all 12 cities were merged and analyzed with Stata 14.0 complex survey data analysis tools in which each city was treated as its own strata. Missing data for those who did not test were imputed HIV+ if they reported testing positive before and were taking antiretroviral therapy. A total of 4176 men were recruited in the 12 cities. The average time to completion was 10.2 weeks. The longest chain length varied from 8 to 21 waves. The sample size was achieved in all but 2 cities. A total of 3958 of the 4176 respondents agreed to test for HIV (90.2%). For results without imputation, 17.5% (95%CI: 14.7–20.7) of our sample was HIV positive. With imputation, 18.4% (95%CI: 15.4–21.7) were seropositive. HIV prevalence increased beyond expectations from the results of the 2009 survey (12.1%; 95%CI: 10.0–14.5) to 18.4%; CI95%: 15.4 to 21.7 in 2016. This increase accompanies Brazil's focus on the treatment to prevention strategy, and a decrease in support for community-based organizations and community prevention programs. PMID:29794604

High variability of HIV and HCV seroprevalence and risk behaviours among people who inject drugs: results from a cross-sectional study using respondent-driven sampling in eight German cities (2011-14).

PubMed

Wenz, Benjamin; Nielsen, Stine; Gassowski, Martyna; Santos-Hövener, Claudia; Cai, Wei; Ross, R Stefan; Bock, Claus-Thomas; Ratsch, Boris-Alexander; Kücherer, Claudia; Bannert, Norbert; Bremer, Viviane; Hamouda, Osamah; Marcus, Ulrich; Zimmermann, Ruth

2016-09-05

People who inject drugs (PWID) are at increased risk of acquiring and transmitting HIV and Hepatitis C (HCV) due to sharing injection paraphernalia and unprotected sex. To generate seroprevalence data on HIV and HCV among PWID and related data on risk behaviour, a multicentre sero- and behavioural survey using respondent driven sampling (RDS) was conducted in eight German cities between 2011 and 2014. We also evaluated the feasibility and effectiveness of RDS for recruiting PWID in the study cities. Eligible for participation were people who had injected drugs within the last 12 months, were 16 years or older, and who consumed in one of the study cities. Participants were recruited, using low-threshold drop-in facilities as study sites. Initial seeds were selected to represent various sub-groups of people who inject drugs (PWID). Participants completed a face-to-face interview with a structured questionnaire about socio-demographics, sexual and injecting risk behaviours, as well as the utilisation of health services. Capillary blood samples were collected as dried blood spots and were anonymously tested for serological and molecular markers of HIV and HCV. The results are shown as range of proportions (min. and max. values (%)) in the respective study cities. For evaluation of the sampling method we applied criteria from the STROBE guidelines. Overall, 2,077 PWID were recruited. The range of age medians was 29-41 years, 18.5-35.3 % of participants were female, and 9.2-30.6 % were foreign born. Median time span since first injection were 10-18 years. Injecting during the last 30 days was reported by 76.0-88.4 % of participants. Sharing needle/syringes (last 30 days) ranged between 4.7 and 22.3 %, while sharing unsterile paraphernalia (spoon, filter, water, last 30 days) was reported by 33.0-43.8 %. A majority of participants (72.8-85.8 %) reported incarceration at least once, and 17.8-39.8 % had injected while incarcerated. Between 30.8 and 66.2 % were currently in opioid substitution therapy. Unweighted HIV seroprevalence ranged from 0-9.1 %, HCV from 42.3-75.0 %, and HCV-RNA from 23.1-54.0 %. The implementation of RDS as a recruiting method in cooperation with low-threshold drop in facilities was well accepted by both staff and PWID. We reached our targeted sample size in seven of eight cities. In the recruited sample of mostly current injectors with a long duration of injecting drug use, seroprevalence for HIV and HCV varied greatly between the city samples. HCV was endemic among participants in all city samples. Our results demonstrate the necessity of intensified prevention strategies for blood-borne infections among PWID in Germany.

Exploration of malingering indices in the Wechsler Adult Intelligence Scale-Fourth Edition Digit Span subtest.

PubMed

Reese, Caitlin S; Suhr, Julie A; Riddle, Tara L

2012-03-01

Prior research shows that Digit Span is a useful embedded measure of malingering. However, the Wechsler Adult Intelligence Scale-IV (Wechsler, 2008) altered Digit Span in meaningful ways, necessitating another look at Digit Span as an embedded measure of malingering. Using a simulated malingerer design, we examined the predictive accuracy of existing Digit Span validity indices and explored whether patterns of performance utilizing the new version would provide additional evidence for malingering. Undergraduates with a history of mild head injury performed with best effort or simulated impaired cognition and were also compared with a large sample of non-head-injured controls. Previously established cutoffs for the age-corrected scaled score and Reliable Digit Span (RDS) performed similarly in the present samples. Patterns of RDS length using all three subscales of the new scale were different in malingerers when compared with both head-injured and non-head-injured controls. Two potential alternative RDS scores were introduced, which showed better sensitivity than the traditional RDS, while retaining specificity to malingering.

Strategies to uncover undiagnosed HIV infection among heterosexuals at high risk and link them to HIV care with high retention: a "seek, test, treat, and retain" study.

PubMed

Gwadz, Marya; Cleland, Charles M; Hagan, Holly; Jenness, Samuel; Kutnick, Alexandra; Leonard, Noelle R; Applegate, Elizabeth; Ritchie, Amanda S; Banfield, Angela; Belkin, Mindy; Cross, Bridget; Del Olmo, Montserrat; Ha, Katharine; Martinez, Belkis Y; McCright-Gill, Talaya; Swain, Quentin L; Perlman, David C; Kurth, Ann E

2015-05-10

Over 50,000 individuals become infected with HIV annually in the U.S., and over a quarter of HIV infected individuals are heterosexuals. Undiagnosed HIV infection, as well as a lack of retention in care among those diagnosed, are both primary factors contributing to ongoing HIV incidence. Further, there are racial/ethnic disparities in undiagnosed HIV and engagement in care, with African Americans/Blacks and Latinos remaining undiagnosed longer and less engaged in care than Whites, signaling the need for culturally targeted intervention approaches to seek and test those with undiagnosed HIV infection, and link them to care with high retention. The study has two components: one to seek out and test heterosexuals at high risk for HIV infection, and another to link those found infected to HIV care with high retention. We will recruit sexually active African American/Black and Latino adults who have opposite sex partners, negative or unknown HIV status, and reside in locations with high poverty and HIV prevalence. The "Seek and Test" component will compare the efficacy and cost effectiveness of two strategies to uncover undiagnosed HIV infection: venue-based sampling and respondent-driven sampling (RDS). Among those recruited by RDS and found to have HIV infection, a "Treat and Retain" component will assess the efficacy of a peer-driven intervention compared to a control arm with respect to time to an HIV care appointment and health indicators using a cluster randomized controlled trial design to minimize contamination. RDS initial seeds will be randomly assigned to the intervention or control arm at a 1:1 ratio and all recruits will be assigned to the same arm as the recruiter. Participants will be followed for 12 months with outcomes assessed using medical records and biomarkers, such as HIV viral load. Heterosexuals do not test for HIV as frequently as and are diagnosed later than other risk groups. The study has the potential to contribute an efficient, innovative, and sustainable multi-level recruitment approach and intervention to the HIV prevention portfolio. Because the majority of heterosexuals at high risk are African American/Black or Latino, the study has great potential to reduce racial/ethnic disparities in HIV/AIDS. ClinicalTrials.gov, NCT01607541, Registered May 23, 2012.

Bell experiments with random destination sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sciarrino, Fabio; Mataloni, Paolo; Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche

2011-03-15

It is generally assumed that sources randomly sending two particles to one or two different observers, random destination sources (RDSs), cannot be used for genuine quantum nonlocality tests because of the postselection loophole. We demonstrate that Bell experiments not affected by the postselection loophole may be performed with (i) an RDS and local postselection using perfect detectors, (ii) an RDS, local postselection, and fair sampling assumption with any detection efficiency, and (iii) an RDS and a threshold detection efficiency required to avoid the detection loophole. These results allow the adoption of RDS setups which are simpler and more efficient formore » long-distance free-space Bell tests, and extend the range of physical systems which can be used for loophole-free Bell tests.« less

Using Respondent Driven Sampling to Identify Malaria Risks and Occupational Networks among Migrant Workers in Ranong, Thailand

PubMed Central

Wangroongsarb, Piyaporn; Hwang, Jimee; Thwing, Julie; Karuchit, Samart; Kumpetch, Suthon; Rand, Alison; Drakeley, Chris; MacArthur, John R.; Kachur, S. Patrick; Satimai, Wichai; Meek, Sylvia; Sintasath, David M.

2016-01-01

Background Ranong Province in southern Thailand is one of the primary entry points for migrants entering Thailand from Myanmar, and borders Kawthaung Township in Myanmar where artemisinin resistance in malaria parasites has been detected. Areas of high population movement could increase the risk of spread of artemisinin resistance in this region and beyond. Methods A respondent-driven sampling (RDS) methodology was used to compare migrant populations coming from Myanmar in urban (Site 1) vs. rural (Site 2) settings in Ranong, Thailand. The RDS methodology collected information on knowledge, attitudes, and practices for malaria, travel and occupational histories, as well as social network size and structure. Individuals enrolled were screened for malaria by microscopy, Real Time-PCR, and serology. Results A total of 619 participants were recruited in Ranong City and 623 participants in Kraburi, a rural sub-district. By PCR, a total of 14 (1.1%) samples were positive (2 P. falciparum in Site 1; 10 P. vivax, 1 Pf, and 1 P. malariae in Site 2). PCR analysis demonstrated an overall weighted prevalence of 0.5% (95% CI, 0–1.3%) in the urban site and 1.0% (95% CI, 0.5–1.7%) in the rural site for all parasite species. PCR positivity did not correlate with serological positivity; however, as expected there was a strong association between antibody prevalence and both age and exposure. Access to long-lasting insecticidal treated nets remains low despite relatively high reported traditional net use among these populations. Conclusions The low malaria prevalence, relatively smaller networks among migrants in rural settings, and limited frequency of travel to and from other areas of malaria transmission in Myanmar, suggest that the risk for the spread of artemisinin resistance from this area may be limited in these networks currently but may have implications for regional malaria elimination efforts. PMID:28033322

Investigation of alcohol-related social norms among youth aged 14–17 years in Perth, Western Australia: protocol for a respondent-driven sampling study

PubMed Central

Hildebrand, Janina; Maycock, Bruce; Howat, Peter; Burns, Sharyn; Allsop, Steve; Dhaliwal, Satvinder; Lobo, Roanna

2013-01-01

Introduction Alcohol use among young people is a major public health concern in Australia and internationally. Research elucidating social norms influencing alcohol use supports the desire to conform to peers. However, there is a lack of evidence on how social norms are transmitted from the community to young people and between family members and peers, as previous studies are limited to mainly school and university environments. This article describes the proposed process to investigate common alcohol-related norms held by 14-year-olds to 17-year-olds in Perth, Western Australia, and to clarify the process and pathways through which proalcohol norms are transmitted to adolescents. Methods and analysis This cross-sectional quantitative study will use respondent-driven sampling (RDS) to recruit a sample of 672 adolescents from sporting groups, youth programmes and the community in Perth. Data will be collected with a previously developed and validated multidimensional online survey instrument. A variety of strategies will be explored to aid participation including face-to-face recruitment and survey administration, web-based RDS and a ‘mature minor’ consent assessment protocol. Data analysis will include descriptive statistics of demographic characteristics, as well as social network and dyadic analyses, to explore the connections between shared understanding of norms and behaviours among individuals and how these translate into reported practices. Ethics and dissemination This research is expected to extend our understanding of normative development pathways to inform future interventions, and will be widely disseminated through conference presentations, peer-reviewed papers, media channels and community seminars. A study reference group of key health industry stakeholders will be established to encourage integration of study findings into policy and practice, and results will guide the development of community interventions. The Curtin University Human Research Ethics Committee has granted approval for this research. PMID:24154519

HIV and STI control in El Salvador: results from an integrated behavioural survey among men who have sex with men.

PubMed

Creswell, Jacob; Guardado, Maria Elena; Lee, Janet; Nieto, Ana Isabel; Kim, Andrea A; Monterroso, Edgar; Paz-Bailey, Gabriela

2012-12-01

This cross-sectional study investigates HIV, other sexually transmitted infections (STI), and risk behaviours among men who have sex with men (MSM) in two cities in El Salvador. Respondent-driven sampling (RDS) was used to recruit MSM in the cities of San Salvador and San Miguel, El Salvador. Participants responded to questions about HIV risk behaviours; and blood, urine and anal swabs were collected. Blood samples were tested for herpes simplex type 2, syphilis and HIV infection. Urine and anal samples were tested by polymerase chain reaction (PCR) for Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium. HIV-positive samples were tested with the BED capture enzyme immunoassay to distinguish recent from longstanding HIV infection. We estimated population-adjusted prevalence of behavioural variables, STI and HIV, and identified risk factors for HIV. The final sample included 596 and 195 MSM in San Salvador and San Miguel, respectively. Consistent condom use was low across all partner types as was recent HIV testing. RDS-adjusted HIV prevalence was 10.8% (95% CI 7.4% to 14.7%) in San Salvador, and 8.8% (95% CI 4.2% to 14.5%) in San Miguel. The proportion of recent testing among HIV-positive samples was 20%. Prevalence of any bacterial STI by PRC testing was 12.7% (95% CI 8.2% to 17.5%) in San Salvador, and 9.6% (95% CI 4.9% to 15.4%) in San Miguel. We found a high prevalence of HIV, high levels of recent infection, and low condom usage. In El Salvador, targeted interventions towards MSM are needed to promote condom use, as well as to diagnose, treat and prevent HIV and other STIs.

HIV Community Viral Load and Factors Associated With Elevated Viremia Among a Community-Based Sample of Men Who Have Sex With Men in Vancouver, Canada.

PubMed

Moore, David M; Cui, Zishan; Lachowsky, Nathan; Raymond, Henry F; Roth, Eric; Rich, Ashleigh; Sereda, Paul; Howard, Terry; McFarland, Willi; Lal, Allan; Montaner, Julio; Corneil, Trevor; Hogg, Robert S

2016-05-01

We developed estimates of community viral load (VL) and risk factors for unsuppressed VL from a cross-sectional study of men who have sex with men (MSM) in Vancouver, Canada. MSM were recruited from February 25, 2012 to February 28, 2014 using respondent-driven sampling (RDS). Participants completed a computer-assisted self-interview questionnaire and a nurse-administered point-of-care HIV test. For HIV-positive participants, we conducted VL and CD4 cell counts. We used RDS-weighted analysis to obtain population estimates of key variables and multivariable logistic regression to examine factors associated with having a VL of ≥200 copies per milliliter among HIV-positive participants. We recruited 719 participants, of whom 119 (16.6%) were seeds. Our estimate of the population prevalence of HIV was 23.4% [95% confidence interval (CI): 15.8% to 31.0%] after RDS adjustments. We estimated that 18.6% (95% CI: 8.8% to 30.4%) of HIV-positive MSM in Vancouver had a VL of ≥200 copies per milliliter. Having an unsuppressed VL was associated with non-white ethnicity [adjusted odds ratio (AOR) = 4.34; 95% CI: 1.67 to 11.1], an annual income of <$15,000 CAD (AOR = 6.43; 95% CI: 2.08 to 19.9), using gamma-hydroxy butyrate in the previous 6 months (AOR = 4.85; 95% CI: 1.79 to 13.2), unprotected anal intercourse with a known HIV-negative or an unknown serostatus partner (AOR = 3.13; 95% CI: 1.10 to 8.90), and disclosing one's HIV serostatus ≥50% of the time (AOR = 7.04; 95% CI: 1.01 to 49.1). Despite a high prevalence of HIV, we estimated that a small proportion of HIV-positive MSM have undiagnosed HIV and unsuppressed VL. Our results highlight the importance of continued work to address health inequities using a framework based on social determinants of health.

Comparing HIV risk-related behaviors between 2 RDS national samples of MSM in Brazil, 2009 and 2016.

PubMed

Guimarães, Mark Drew Crosland; Kendall, Carl; Magno, Laio; Rocha, Gustavo Machado; Knauth, Daniela Riva; Leal, Andrea Fachel; Dourado, Ines; Veras, Maria Amélia; Brito, Ana Maria de; Kerr, Ligia Regina Franco Sansigolo

2018-05-01

Periodic monitoring of sociobehavior characteristics at a national level is an essential component of understanding the dynamics the human immunodeficiency virus (HIV) epidemic worldwide, including Brazil. This paper compares descriptive sociobehavior characteristics in 2 national cross-sectional HIV biological behavioral surveillance surveys (BBSS) conducted in 2009 and 2016 among men who have sex with men (MSM) in Brazil. Respondent driven sampling (RDS) was used for recruitment in both years. Overall proportions were weighted according to Gile's estimator using RDS Analyst Software and 95% confidence intervals were calculated for comparisons between the 2 periods. Further comparisons were stratified by age groups (<25 and 25+ years old). Overall, 3749 and 4176 MSM were recruited in 2009 and 2016, respectively. In 2016, participants were younger than 25 years old (58.3%), with 12 or more years of education (70.4%), with higher socioeconomic status (40.7%), and had a higher proportion of whites (31.8%), as compared to 2009. Also, participants in 2016 reported less alcohol use and binge drinking, but used illicit drugs more frequently. There was an increase among MSM who self-reported their HIV risk as low and had low HIV knowledge while the proportion of those who were never tested for HIV dropped from 49.8% in 2009 to 33.8% in 2016. Although more than three-quarters received free condoms in both years, STD counseling remained low (32% and 38% for 2009 and 2016, respectively). Sexual risk behavior remained at high levels, especially unprotected anal receptive sex and sex with multiple partners. Younger MSM (<25 years old) showed riskier sexual practices than those 25+ years old, when comparing 2016 to 2009. Our results indicate a worrisome risk behavior trend among Brazilian MSM, especially among younger ones. These results can contribute for a better understanding of the HIV epidemics in Brazil, with timely shift in strategies so improved effectiveness in public health prevention efforts can be achieved.

Parsing Social Network Survey Data from Hidden Populations Using Stochastic Context-Free Grammars

PubMed Central

Poon, Art F. Y.; Brouwer, Kimberly C.; Strathdee, Steffanie A.; Firestone-Cruz, Michelle; Lozada, Remedios M.; Kosakovsky Pond, Sergei L.; Heckathorn, Douglas D.; Frost, Simon D. W.

2009-01-01

Background Human populations are structured by social networks, in which individuals tend to form relationships based on shared attributes. Certain attributes that are ambiguous, stigmatized or illegal can create a ÔhiddenÕ population, so-called because its members are difficult to identify. Many hidden populations are also at an elevated risk of exposure to infectious diseases. Consequently, public health agencies are presently adopting modern survey techniques that traverse social networks in hidden populations by soliciting individuals to recruit their peers, e.g., respondent-driven sampling (RDS). The concomitant accumulation of network-based epidemiological data, however, is rapidly outpacing the development of computational methods for analysis. Moreover, current analytical models rely on unrealistic assumptions, e.g., that the traversal of social networks can be modeled by a Markov chain rather than a branching process. Methodology/Principal Findings Here, we develop a new methodology based on stochastic context-free grammars (SCFGs), which are well-suited to modeling tree-like structure of the RDS recruitment process. We apply this methodology to an RDS case study of injection drug users (IDUs) in Tijuana, México, a hidden population at high risk of blood-borne and sexually-transmitted infections (i.e., HIV, hepatitis C virus, syphilis). Survey data were encoded as text strings that were parsed using our custom implementation of the inside-outside algorithm in a publicly-available software package (HyPhy), which uses either expectation maximization or direct optimization methods and permits constraints on model parameters for hypothesis testing. We identified significant latent variability in the recruitment process that violates assumptions of Markov chain-based methods for RDS analysis: firstly, IDUs tended to emulate the recruitment behavior of their own recruiter; and secondly, the recruitment of like peers (homophily) was dependent on the number of recruits. Conclusions SCFGs provide a rich probabilistic language that can articulate complex latent structure in survey data derived from the traversal of social networks. Such structure that has no representation in Markov chain-based models can interfere with the estimation of the composition of hidden populations if left unaccounted for, raising critical implications for the prevention and control of infectious disease epidemics. PMID:19738904

Using a social ecological framework to characterize the correlates of HIV among men who have sex with men in Lomé, Togo.

PubMed

Ruiseñor-Escudero, Horacio; Grosso, Ashley; Ketende, Sosthenes; Pitche, Vincent; Simplice, Anato; Tchalla, Jules; Sodji, Dometo; Liestman, Ben; Kapesa, Laurent; Baral, Stefan

2017-09-01

In the mixed and concentrated HIV epidemics of West Africa, the relative disproportionate burden of HIV among men who have sex with men (MSM) compared to other reproductive-age men is higher than that observed in Southern and Eastern Africa. Our aim is to describe the correlates of HIV infection among MSM living in Lomé, Togo, using the Modified Social Ecological Model (MSEM). A total of 354 MSM ≥18 years of age were recruited using respondent driven sampling (RDS) for a cross-sectional survey in Lomé, Togo. Participants completed a structured questionnaire and were tested for HIV and syphilis. Statistical analyses included RDS-weighted proportions, bootstrapped confidence intervals (CI), and logistic regression models. Mean age of participants was 22 years; 71.5% were between 18 and 24 years. RDS-weighted HIV prevalence was 9.2% (95% CI=5.4-13.2). In RDS-adjusted (RDSa) bivariate analysis, HIV infection was associated with disclosure of sexual orientation to a family member, discriminatory remarks made by family members, forced sex, ever being blackmailed because of being MSM, community and social stigma and discrimination, and health service stigma and discrimination. In the multivariable model, HIV infection was associated with being 25 years or older (RDSa adjusted OR (aOR)=4.3, 95% CI=1.5-12.2), and having sex with a man before age 18 (RDSa aOR=0.3, 95% CI=0.1-0.9). HIV prevalence was more than seven times higher than that estimated among adults aged 15-49 living in Togo. Using the MSEM, network, community, and policy-level factors were associated with HIV infection among MSM in Lomé, Togo. Through the use of this flexible risk framework, a structured assessment of the multiple levels of HIV risk was characterized, highlighting the need for evidence-based and human-rights affirming combination HIV prevention and treatment programs that address these various risk levels for MSM in Lomé.

The complex interplay of social networks, geography and HIV risk among Malaysian Drug Injectors: Results from respondent-driven sampling.

PubMed

Zelenev, Alexei; Long, Elisa; Bazazi, Alexander R; Kamarulzaman, Adeeba; Altice, Frederick L

2016-11-01

HIV is primarily concentrated among people who inject drugs (PWID) in Malaysia, where currently HIV prevention and treatment coverage is inadequate. To improve the targeting of interventions, we examined HIV clustering and the role that social networks and geographical distance play in influencing HIV transmission among PWID. Data were derived from a respondent-driven survey sample (RDS) collected during 2010 of 460 PWID in greater Kuala Lumpur. Analysis focused on socio-demographic, clinical, behavioural, and network information. Spatial probit models were developed based on a distinction between the influence of peers (individuals nominated through a recruitment network) and neighbours (residing a close distance to the individual). The models were expanded to account for the potential influence of the network formation. Recruitment patterns of HIV-infected PWID clustered both spatially and across the recruitment networks. In addition, HIV-infected PWID were more likely to have peers and neighbours who inject with clean needles were HIV-infected and lived nearby (<5km), more likely to have been previously incarcerated, less likely to use clean needles (26.8% vs 53.0% of the reported injections, p<0.01), and have fewer recent injection partners (2.4 vs 5.4, p<0.01). The association between the HIV status of peers and neighbours remained significantly correlated even after controlling for unobserved variation related to network formation and sero-sorting. The relationship between HIV status across networks and space in Kuala Lumpur underscores the importance of these factors for surveillance and prevention strategies, and this needs to be more closely integrated. RDS can be applied to identify injection network structures, and this provides an important mechanism for improving public health surveillance, accessing high-risk populations, and implementing risk-reduction interventions to slow HIV transmission. Copyright © 2016 Elsevier B.V. All rights reserved.

Prevalence and patterns of victimization and polyvictimization among female sex workers in Soweto, a South African township: a cross-sectional, respondent-driven sampling study

PubMed Central

Coetzee, J.; Gray, G. E.; Jewkes, R.

2017-01-01

ABSTRACT Background: Female sex workers (FSWs) are disproportionately affected by violence from multiple partner categories. This increases their vulnerability to HIV. Objectives: To describe patterns of violence and polyvictimization among female SWs in Soweto. Methods: A respondent-driven sampling (RDS) recruitment methodology was used to enrol 508 Soweto-based FSWs using a survey instrument. Raw and RDS adjusted data were descriptively analysed, Spearman’s correlation and chi2 test of association were used to show associations. Polyvictimization patterns are shown within a modified Venn diagram. Results: The median age of FSWs in Soweto was 31 years, and most had an incomplete education (74.2%). The prevalence of exposure to physical/sexual intimate partner violence (IPV) in the past year was 53.8%, 46.8% by clients, and 18.5% by police. Past year prevalence of sexual/physical violence by any perpetrator category was 70.8% and lifetime exposure was 76.0%. Childhood sexual violence was reported by 44.3%. Lifetime non-partner rape was 55.5% and all rape exposure was 62.4%. As a result of engaging in sex work in the past year, 65.2% women had been discriminated against. Client, police, IPV, and childhood trauma were all significantly associated with one another, with IPV being the most common co-occurrence. Polyvictimization was seen in almost two-thirds of FSWs, and increased with exposure to discrimination. Conclusion: In Soweto, FSWs are exposed to high rates of violence in multiple forms across their lifetime. Our findings show that violence continues unabated into adulthood at levels far higher than in the general population and overall at higher levels than previously recorded among SWs in South Africa. We argue that violence against FSWs is rooted in discrimination. The disparate burden of violence on FSWs requires urgent interventions to proactively address and reframe the normalisation of violence against all women. PMID:29211633

Intervenable factors associated with suicide risk in transgender persons: a respondent driven sampling study in Ontario, Canada.

PubMed

Bauer, Greta R; Scheim, Ayden I; Pyne, Jake; Travers, Robb; Hammond, Rebecca

2015-06-02

Across Europe, Canada, and the United States, 22-43 % of transgender (trans) people report a history of suicide attempts. We aimed to identify intervenable factors (related to social inclusion, transphobia, or sex/gender transition) associated with reduced risk of past-year suicide ideation or attempt, and to quantify the potential population health impact. The Trans PULSE respondent-driven sampling (RDS) survey collected data from trans people age 16+ in Ontario, Canada, including 380 who reported on suicide outcomes. Descriptive statistics and multivariable logistic regression models were weighted using RDS II methods. Counterfactual risk ratios and population attributable risks were estimated using model-standardized risks. Among trans Ontarians, 35.1 % (95 % CI: 27.6, 42.5) seriously considered, and 11.2 % (95 % CI: 6.0, 16.4) attempted, suicide in the past year. Social support, reduced transphobia, and having any personal identification documents changed to an appropriate sex designation were associated with large relative and absolute reductions in suicide risk, as was completing a medical transition through hormones and/or surgeries (when needed). Parental support for gender identity was associated with reduced ideation. Lower self-reported transphobia (10(th) versus 90(th) percentile) was associated with a 66 % reduction in ideation (RR = 0.34, 95 % CI: 0.17, 0.67), and an additional 76 % reduction in attempts among those with ideation (RR = 0.24; 95 % CI: 0.07, 0.82). This corresponds to potential prevention of 160 ideations per 1000 trans persons, and 200 attempts per 1,000 with ideation, based on a hypothetical reduction of transphobia from current levels to the 10(th) percentile. Large effect sizes were observed for this controlled analysis of intervenable factors, suggesting that interventions to increase social inclusion and access to medical transition, and to reduce transphobia, have the potential to contribute to substantial reductions in the extremely high prevalences of suicide ideation and attempts within trans populations. Such interventions at the population level may require policy change.

Prevalence and patterns of victimization and polyvictimization among female sex workers in Soweto, a South African township: a cross-sectional, respondent-driven sampling study.

PubMed

Coetzee, J; Gray, G E; Jewkes, R

2017-01-01

Female sex workers (FSWs) are disproportionately affected by violence from multiple partner categories. This increases their vulnerability to HIV. To describe patterns of violence and polyvictimization among female SWs in Soweto. A respondent-driven sampling (RDS) recruitment methodology was used to enrol 508 Soweto-based FSWs using a survey instrument. Raw and RDS adjusted data were descriptively analysed, Spearman's correlation and chi 2 test of association were used to show associations. Polyvictimization patterns are shown within a modified Venn diagram. The median age of FSWs in Soweto was 31 years, and most had an incomplete education (74.2%). The prevalence of exposure to physical/sexual intimate partner violence (IPV) in the past year was 53.8%, 46.8% by clients, and 18.5% by police. Past year prevalence of sexual/physical violence by any perpetrator category was 70.8% and lifetime exposure was 76.0%. Childhood sexual violence was reported by 44.3%. Lifetime non-partner rape was 55.5% and all rape exposure was 62.4%. As a result of engaging in sex work in the past year, 65.2% women had been discriminated against. Client, police, IPV, and childhood trauma were all significantly associated with one another, with IPV being the most common co-occurrence. Polyvictimization was seen in almost two-thirds of FSWs, and increased with exposure to discrimination. In Soweto, FSWs are exposed to high rates of violence in multiple forms across their lifetime. Our findings show that violence continues unabated into adulthood at levels far higher than in the general population and overall at higher levels than previously recorded among SWs in South Africa. We argue that violence against FSWs is rooted in discrimination. The disparate burden of violence on FSWs requires urgent interventions to proactively address and reframe the normalisation of violence against all women.

Hepatitis C virus seroprevalence among people who inject drugs and factors associated with infection in eight Russian cities

PubMed Central

2014-01-01

Background Behavioural surveillance among people who inject drugs (PWID) and testing for hepatitis C virus (HCV) and HIV is needed to understand the scope of both epidemics in at-risk populations and to suggest steps to improve their health. Methods PWID were recruited using respondent-driven sampling (RDS) in eight Russian cities. A standardized survey was administered to collect sociodemographic and behavioral information. Blood specimens were obtained for serological testing for HCV and HIV-1. Data across the eight sites were pooled to identify individual-, network-, and city-level factors associated with positive HCV serostatus. Results Among 2,596 PWID participating in the study, 1,837 tested positive for HCV (71%). The sample was 73% male and the mean age was 28. Very few PWID reported regular contact with harm reduction programs. Factors associated with testing positive for HCV were longer duration of injection drug use, testing positive for HIV-1, sharing non-syringe injection paraphernalia and water for rinsing syringes, and larger social network size. Factors negatively associated with HCV-positive serostatus were injecting with a used syringe and two city-level factors: longer mean RDS recruitment chain in a city and higher levels of injecting stimulants. Conclusions HCV prevalence in all eight Russian cities is at the higher end of the range of HCV prevalence among PWID in Europe, which provides evidence that more resources, better prevention programs, and accelerated treatment targeting PWID are needed to control the HCV epidemic. PMID:25253447

Homelessness and Other Risk Factors for HIV Infection in the Current Outbreak Among Injection Drug Users in Athens, Greece

PubMed Central

Sypsa, Vana; Paraskevis, Dimitrios; Malliori, Meni; Nikolopoulos, Georgios K.; Panopoulos, Anastasios; Kantzanou, Maria; Katsoulidou, Antigoni; Psichogiou, Mina; Fotiou, Anastasios; Pharris, Anastasia; Van De Laar, Marita; Wiessing, Lucas; Jarlais, Don Des; Friedman, Samuel R.

2015-01-01

Objectives. We examined HIV prevalence and risk factors among injection drug users (IDUs) in Athens, Greece, during an HIV outbreak. Methods. We used respondent-driven sampling (RDS) to recruit 1404 IDUs to the Aristotle intervention in August to October 2012. We interviewed participants and tested for HIV. We performed bivariate and multivariate analyses. Results. Estimated HIV prevalence was 19.8% (RDS-weighted prevalence = 14.8%). Odds of infection were 2.3 times as high in homeless as in housed IDUs and 2.1 times as high among IDUs who injected at least once per day as among less frequent injectors (both, P < .001). Six percent of men and 23.5% of women reported transactional sex in the past 12 months, and condom use was low. Intercourse with non-IDUs was common (53.2% of men, 25.6% of women). Among IDUs who had been injecting for 2 years or less the estimated incidence rate was 23.4 new HIV cases per 100 person-years at risk. Conclusions. Efforts to reduce HIV transmission should address homelessness as well as scaling up prevention services, such as needle and syringe distribution and other risk reduction interventions. PMID:24524508

Engagement with HIV prevention treatment and care among female sex workers in Zimbabwe: a respondent driven sampling survey.

PubMed

Cowan, Frances M; Mtetwa, Sibongile; Davey, Calum; Fearon, Elizabeth; Dirawo, Jeffrey; Wong-Gruenwald, Ramona; Ndikudze, Theresa; Chidiya, Samson; Benedikt, Clemens; Busza, Joanna; Hargreaves, James R

2013-01-01

To determine the HIV prevalence and extent of engagement with HIV prevention and care among a representative sample of Zimbabwean sex workers working in Victoria Falls, Hwange and Mutare. Respondent driven sampling (RDS) surveys conducted at each site. Sex workers were recruited using respondent driven sampling with each respondent limited to recruiting 2 peers. Participants completed an interviewer-administered questionnaire and provided a finger prick blood sample for HIV antibody testing. Statistical analysis took account of sampling method. 870 women were recruited from the three sites. HIV prevalence was between 50 and 70%. Around half of those confirmed HIV positive were aware of their HIV status and of those 50-70% reported being enrolled in HIV care programmes. Overall only 25-35% of those with laboratory-confirmed HIV were accessing antiretroviral therapy. Among those reporting they were HIV negative, 21-28% reported having an HIV test in the last 6 months. Of those tested HIV negative, most (65-82%) were unaware of their status. Around two-thirds of sex workers reported consistent condom use with their clients. As in other settings, sex workers reported high rates of gender based violence and police harassment. This survey suggests that prevalence of HIV is high among sex workers in Zimbabwe and that their engagement with prevention, treatment and care is sub-optimal. Intensifying prevention and care interventions for sex workers has the potential to markedly reduce HIV and social risks for sex workers, their clients and the general population in Zimbabwe and elsewhere in the region.

High prevalence of HIV, chlamydia and gonorrhoea among men who have sex with men and transgender women attending trusted community centres in Abuja and Lagos, Nigeria.

PubMed

Keshinro, Babajide; Crowell, Trevor A; Nowak, Rebecca G; Adebajo, Sylvia; Peel, Sheila; Gaydos, Charlotte A; Rodriguez-Hart, Cristina; Baral, Stefan D; Walsh, Melissa J; Njoku, Ogbonnaya S; Odeyemi, Sunday; Ngo-Ndomb, Teclaire; Blattner, William A; Robb, Merlin L; Charurat, Manhattan E; Ake, Julie

2016-01-01

Sexually transmitted infection (STI) and HIV prevalence have been reported to be higher amongst men who have sex with men (MSM) in Nigeria than in the general population. The objective of this study was to characterize the prevalence of HIV, chlamydia and gonorrhoea in this population using laboratory-based universal testing. TRUST/RV368 represents a cohort of MSM and transgender women (TGW) recruited at trusted community centres in Abuja and Lagos, Nigeria, using respondent-driven sampling (RDS). Participants undergo a structured comprehensive assessment of HIV-related risks and screening for anorectal and urogenital Chlamydia trachomatis and Neisseria gonorrhoeae , and HIV. Crude and RDS-weighted prevalence estimates with 95% confidence intervals (CIs) were calculated. Log-binomial regression was used to explore factors associated with prevalent HIV infection and STIs. From March 2013 to January 2016, 862 MSM and TGW (316 in Lagos and 546 in Abuja) underwent screening for HIV, chlamydia and gonorrhoea at study enrolment. Participants' median age was 24 years [interquartile range (IQR) 21-27]. One-third (34.2%) were identified as gay/homosexual and 65.2% as bisexual. The overall prevalence of HIV was 54.9%. After adjusting for the RDS recruitment method, HIV prevalence in Abuja was 43.5% (95% CI 37.3-49.6%) and in Lagos was 65.6% (95% CI 54.7-76.5%). The RDS-weighted prevalence of chlamydia was 17.0% (95% CI 11.8-22.3%) in Abuja and 18.3% (95% CI 11.1-25.4%) in Lagos. Chlamydia infection was detected only at the anorectal site in 70.2% of cases. The RDS-weighted prevalence of gonorrhoea was 19.1% (95% CI 14.6-23.5%) in Abuja and 25.8% (95% CI 17.1-34.6%) in Lagos. Overall, 84.2% of gonorrhoea cases presented with anorectal infection only. Over 95% of STI cases were asymptomatic. In a multivariable model, increased risk for chlamydia/gonorrhoea was associated with younger age, gay/homosexual sexual orientation and higher number of partners for receptive anal sex. HIV infection was associated with older age, female gender identity and number of partners for receptive anal sex. There is a high burden of infection with HIV and asymptomatic chlamydia and gonorrhoea among MSM and TGW in Nigeria. Most cases would have been missed without anorectal screening. Interventions are needed to target this population for appropriate STI screening and management beginning at a young age.

Conceptualization and Assessment of Disengagement in Romantic Relationships

PubMed Central

Barry, Robin A.; Lawrence, Erika; Langer, Amie

2008-01-01

Research examining relationship distress and dissolution highlights the importance of romantic disengagement. However, prior conceptualizations and measures of romantic disengagement have tended to combine disengagement with related but distinct constructs hindering the study of romantic disengagement. In the present study we conducted exploratory factor analyses to demonstrate that disengagement is a relatively distinct construct and to clarify the conceptualization of romantic disengagement. More importantly, we developed a novel measure– the Romantic Disengagement Scale (RDS). The RDS demonstrated adequate fit across samples of dating individuals, married couples and women in physically aggressive relationships. The RDS also demonstrated strong divergent and incremental validity. Implications for enhancing conceptual models, research methodology, and clinical interventions are discussed. PMID:19727315

Generational Association Studies of Dopaminergic Genes in Reward Deficiency Syndrome (RDS) Subjects: Selecting Appropriate Phenotypes for Reward Dependence Behaviors

PubMed Central

Blum, Kenneth; Chen, Amanda L. C.; Oscar-Berman, Marlene; Chen, Thomas J. H.; Lubar, Joel; White, Nancy; Lubar, Judith; Bowirrat, Abdalla; Braverman, Eric; Schoolfield, John; Waite, Roger L.; Downs, Bernard W.; Madigan, Margaret; Comings, David E.; Davis, Caroline; Kerner, Mallory M.; Knopf, Jennifer; Palomo, Tomas; Giordano, John J.; Morse, Siobhan A.; Fornari, Frank; Barh, Debmalya; Femino, John; Bailey, John A.

2011-01-01

Abnormal behaviors involving dopaminergic gene polymorphisms often reflect an insufficiency of usual feelings of satisfaction, or Reward Deficiency Syndrome (RDS). RDS results from a dysfunction in the “brain reward cascade,” a complex interaction among neurotransmitters (primarily dopaminergic and opioidergic). Individuals with a family history of alcoholism or other addictions may be born with a deficiency in the ability to produce or use these neurotransmitters. Exposure to prolonged periods of stress and alcohol or other substances also can lead to a corruption of the brain reward cascade function. We evaluated the potential association of four variants of dopaminergic candidate genes in RDS (dopamine D1 receptor gene [DRD1]; dopamine D2 receptor gene [DRD2]; dopamine transporter gene [DAT1]; dopamine beta-hydroxylase gene [DBH]). Methodology: We genotyped an experimental group of 55 subjects derived from up to five generations of two independent multiple-affected families compared to rigorously screened control subjects (e.g., N = 30 super controls for DRD2 gene polymorphisms). Data related to RDS behaviors were collected on these subjects plus 13 deceased family members. Results: Among the genotyped family members, the DRD2 Taq1 and the DAT1 10/10 alleles were significantly (at least p < 0.015) more often found in the RDS families vs. controls. The TaqA1 allele occurred in 100% of Family A individuals (N = 32) and 47.8% of Family B subjects (11 of 23). No significant differences were found between the experimental and control positive rates for the other variants. Conclusions: Although our sample size was limited, and linkage analysis is necessary, the results support the putative role of dopaminergic polymorphisms in RDS behaviors. This study shows the importance of a nonspecific RDS phenotype and informs an understanding of how evaluating single subset behaviors of RDS may lead to spurious results. Utilization of a nonspecific “reward” phenotype may be a paradigm shift in future association and linkage studies involving dopaminergic polymorphisms and other neurotransmitter gene candidates. PMID:22408582

Are patients with diabetes receiving the same message from dietitians and nurses?

PubMed

Venters, Jennifer Y; Hunt, Alice E; Pope, Janet F; Molaison, Elaine F

2004-01-01

The purpose of this study was to determine if registered dietitian (RD) and registered nurse (RN) certified diabetes educators (CDEs) provide similar recommendations regarding carbohydrates and dietary supplements to individuals with diabetes. A survey was mailed to CDEs in the southern United States. Participants were asked to indicate their recommendations for use of carbohydrates, fiber, artificial sweeteners, and 12 selected dietary and herbal supplements when counseling individuals with diabetes. The survey sample consisted of 366 CDEs: 207 were RNs and 159 were RDs. No statistically significant differences were found between RNs and RDs in typical carbohydrate recommendations for treatment of diabetes. However, RDs were more likely than RNs to make recommendations for fiber intake or use of the glycemic index. A significant difference also was found in the treatment of hypoglycemia: RNs were more likely than RDs to recommend consuming a carbohydrate source with protein to treat hypoglycemia. Although some differences existed, RD and RN CDEs are making similar overall recommendations in the treatment of individuals with diabetes.

In-plane optical anisotropy of InAs/GaSb superlattices with alternate interfaces

PubMed Central

2013-01-01

The in-plane optical anisotropy (IPOA) in InAs/GaSb superlattices has been studied by reflectance difference spectroscopy (RDS) at different temperatures ranging from 80 to 300 K. We introduce alternate GaAs- and InSb-like interfaces (IFs), which cause the symmetry reduced from D2d to C2v. IPOA has been observed in the (001) plane along [110] and [11¯0] axes. RDS measurement results show strong anisotropy resonance near critical point (CP) energies of InAs and GaSb. The energy positions show red shift and RDS intensity decreases with the increasing temperature. For the superlattice sample with the thicker InSb-like IFs, energy positions show red shift, and the spectra exhibit stronger IPOA. The excitonic effect is clearly observed by RDS at low temperatures. It demonstrates that biaxial strain results in the shift of the CP energies and IPOA is enhanced by the further localization of the carriers in InSb-like IFs. PMID:23799946

HIV testing and the care continuum among transgender women: population estimates from Rio de Janeiro, Brazil

PubMed Central

Jalil, Emilia M.; Wilson, Erin C.; Luz, Paula M.; Velasque, Luciane; Moreira, Ronaldo I.; Castro, Cristiane V.; Monteiro, Laylla; Garcia, Ana Cristina F.; Cardoso, Sandra W.; Coelho, Lara E.; McFarland, Willi; Liu, Albert Y.; Veloso, Valdilea G.; Buchbinder, Susan; Grinsztejn, Beatriz

2017-01-01

Abstract Introduction: Evidence suggests that, of all affected populations, transgender women (transwomen) may have the heaviest HIV burden worldwide. Little is known about HIV linkage and care outcomes for transwomen. We aimed to estimate population-level indicators of the HIV cascade of care continuum, and to evaluate factors associated with viral suppression among transwomen in Rio de Janeiro, Brazil. Methods: We conducted a respondent-driven sampling (RDS) study of transwomen from August 2015 to January 2016 in Rio de Janeiro, Brazil and collected data on linkage and access to care, antiretroviral treatment and performed HIV viral load testing. We derived population-based estimates of cascade indicators using sampling weights and conducted RDS-weighted logistic regression analyses to evaluate correlates of viral suppression (viral load ≤50 copies/mL). Results: Of the 345 transwomen included in the study, 89.2% (95% CI 55–100%) had been previously tested for HIV, 77.5% (95% CI 48.7–100%) had been previously diagnosed with HIV, 67.2% (95% CI 39.2–95.2) reported linkage to care, 62.2% (95% CI 35.4–88.9) were currently on ART and 35.4% (95% CI 9.5–61.4%) had an undetectable viral load. The final adjusted RDS-weighted logistic regression model for viral suppression indicated that those who self-identified as black (adjusted odds ratio [aOR] 0.06, 95% CI 0.01–0.53, p < 0.01), reported earning ≤U$160/month (aOR 0.11, 95% CI 0.16–0.87, p = 0.04) or reported unstable housing (aOR 0.08, 95% CI 0.01–0.43, p < 0.01) had significantly lower odds of viral suppression. Conclusions: Our cascade indicators for transwomen showed modest ART use and low viral suppression rates. Multi-level efforts including gender affirming care provision are urgently needed to decrease disparities in HIV clinical outcomes among transwomen and reduce secondary HIV transmission to their partners. PMID:28953323

Frequency Modulation and Spatiotemporal Stability of the sCPG in Preterm Infants with RDS

PubMed Central

Barlow, Steven M.; Burch, Mimi; Venkatesan, Lalit; Harold, Meredith; Zimmerman, Emily

2012-01-01

The nonnutritive suck (NNS) is an observable and accessible motor behavior which is often used to make inference about brain development and pre-feeding skill in preterm and term infants. The purpose of this study was to model NNS burst compression pressure dynamics in the frequency and time domain among two groups of preterm infants, including those with respiratory distress syndrome (RDS, N = 15) and 17 healthy controls. Digitized samples of NNS compression pressure waveforms recorded at a 1-week interval were collected 15 minutes prior to a scheduled feed. Regression analysis and ANOVA revealed that healthy preterm infants produced longer NNS bursts and the mean burst initiation cycle frequencies were higher when compared to the RDS group. Moreover, the initial 5 cycles of the NNS burst manifest a frequency modulated (FM) segment which is a significant feature of the suck central pattern generator (sCPG), and differentially expressed in healthy and RDS infants. The NNS burst structure revealed significantly lower spatiotemporal index values for control versus RDS preterm infants during FM, and provides additional information on the microstructure of the sCPG which may be used to gauge the developmental status and progression of oromotor control systems among these fragile infants. PMID:22888359

Prevalence of HIV, syphilis, and other sexually transmitted infections among MSM from three cities in Panama.

PubMed

Hakre, Shilpa; Arteaga, Griselda B; Núñez, Aurelio E; Arambu, Nelson; Aumakhan, Bulbulgul; Liu, Michelle; Peel, Sheila A; Pascale, Juan M; Scott, Paul T

2014-08-01

Respondent-driven sampling (RDS) was used to conduct a biobehavioral survey among men who have sex with men (MSM) in three cities in the Republic of Panama. We estimated the prevalence of HIV, syphilis, and other sexually transmitted infections (STIs), sociodemographic characteristics, and sexual risk behaviors. Among 603 MSM recruited, RDS-adjusted seroprevalences (95 % confidence intervals) were: HIV-David 6.6 % (2.2-11.4 %), Panama 29.4 % (19.7-39.7 %), and Colon 32.6 % (18.0-47.8 %); active syphilis-David 16.0 % (8.9-24.2 %), Panama 24.7 % (16.7-32.9 %), Colon 31.6 % (14.8-47.5 %); resolved HBV infection-David 10.0 % (4.8-16.8 %), Panama 29.4 % (20.0-38.3 %), and Colon 40.6 % (21.9-54.4 %); herpes simplex virus type 2-David 38.4 % (27.9-48.9 %), Panama 62.6 % (52.8-71.0 %), and Colon 72.9 % (57.4-85.8 %). At least a third of MSM in each city self-identified as heterosexual or bisexual. HIV prevalence is concentrated among MSM. Preventive interventions should focus on increasing HIV and syphilis testing, and increasing promotion of condom awareness and use.

HIV, HSV2 and Syphilis Prevalence in Female Sex Workers in Kerman, South-East Iran; Using Respondent-Driven Sampling

PubMed Central

Navadeh, S; Mirzazadeh, A; Mousavi, L; Haghdoost, AA; Fahimfar, N; Sedaghat, A

2012-01-01

Background We estimated the prevalence of HIV, sexually transmitted infections (STIs), and risky behaviors among female sex workers (FSW) in Kerman City, Iran. Methods: Women, 18 years or older, who reported selling sex for at least 6 months during their lifetime and had at least one sexual contact with a client in the recent 12 months were sampled using Responding Driven Sampling (RDS). Participants were interviewed about their sexual behaviors and provided whole blood for HIV, syphilis, and Herpes simplex type 2 (HSV2) testing. Data were analyzed using RDSAT Version 6.0 software. Results: Among samples of 177 FSW, we did not find any HIV positive cases. The weighted prevalence of syphilis and HSV2 were 7.2% and 18.0%, respectively. The reported STI syndromes for the proceeding year of the survey were 36%. Unprotected sexual contact was about 17–22% and link to injecting drug users through injection was about 18%. Conclusion: While this survey found no HIV, there were findings of risky sexual behaviors and STI, markers for potential infection for HIV. The prevalence of STI and sexual risk behaviors for HIV is considerably high in this subpopulation that alarming for an urgent public health preventive measures and national control-plan to be developed and implemented. PMID:23641392

High prevalence of HIV, chlamydia and gonorrhoea among men who have sex with men and transgender women attending trusted community centres in Abuja and Lagos, Nigeria

PubMed Central

Keshinro, Babajide; Crowell, Trevor A; Nowak, Rebecca G; Adebajo, Sylvia; Peel, Sheila; Gaydos, Charlotte A; Rodriguez-Hart, Cristina; Baral, Stefan D; Walsh, Melissa J; Njoku, Ogbonnaya S; Odeyemi, Sunday; Ngo-Ndomb, Teclaire; Blattner, William A; Robb, Merlin L; Charurat, Manhattan E; Ake, Julie

2016-01-01

Introduction Sexually transmitted infection (STI) and HIV prevalence have been reported to be higher amongst men who have sex with men (MSM) in Nigeria than in the general population. The objective of this study was to characterize the prevalence of HIV, chlamydia and gonorrhoea in this population using laboratory-based universal testing. Methods TRUST/RV368 represents a cohort of MSM and transgender women (TGW) recruited at trusted community centres in Abuja and Lagos, Nigeria, using respondent-driven sampling (RDS). Participants undergo a structured comprehensive assessment of HIV-related risks and screening for anorectal and urogenital Chlamydia trachomatis and Neisseria gonorrhoeae, and HIV. Crude and RDS-weighted prevalence estimates with 95% confidence intervals (CIs) were calculated. Log-binomial regression was used to explore factors associated with prevalent HIV infection and STIs. Results From March 2013 to January 2016, 862 MSM and TGW (316 in Lagos and 546 in Abuja) underwent screening for HIV, chlamydia and gonorrhoea at study enrolment. Participants’ median age was 24 years [interquartile range (IQR) 21–27]. One-third (34.2%) were identified as gay/homosexual and 65.2% as bisexual. The overall prevalence of HIV was 54.9%. After adjusting for the RDS recruitment method, HIV prevalence in Abuja was 43.5% (95% CI 37.3–49.6%) and in Lagos was 65.6% (95% CI 54.7–76.5%). The RDS-weighted prevalence of chlamydia was 17.0% (95% CI 11.8–22.3%) in Abuja and 18.3% (95% CI 11.1–25.4%) in Lagos. Chlamydia infection was detected only at the anorectal site in 70.2% of cases. The RDS-weighted prevalence of gonorrhoea was 19.1% (95% CI 14.6–23.5%) in Abuja and 25.8% (95% CI 17.1–34.6%) in Lagos. Overall, 84.2% of gonorrhoea cases presented with anorectal infection only. Over 95% of STI cases were asymptomatic. In a multivariable model, increased risk for chlamydia/gonorrhoea was associated with younger age, gay/homosexual sexual orientation and higher number of partners for receptive anal sex. HIV infection was associated with older age, female gender identity and number of partners for receptive anal sex. Conclusions There is a high burden of infection with HIV and asymptomatic chlamydia and gonorrhoea among MSM and TGW in Nigeria. Most cases would have been missed without anorectal screening. Interventions are needed to target this population for appropriate STI screening and management beginning at a young age. PMID:27931519

Factors associated with HIV among female sex workers in a high HIV prevalent state of India.

PubMed

Medhi, Gajendra Kumar; Mahanta, Jagadish; Paranjape, Ramesh S; Adhikary, Rajatashuvra; Laskar, Nabjyoti; Ngully, P

2012-01-01

The study was carried out to assess the factors associated with HIV seropositivity among female sex workers (FSWs) in Dimapur, Nagaland, a high HIV prevalence state of India. A total of 426 FSWs were recruited into the study using respondent driven sampling (RDS). Data on demographic characteristics, sexual and injecting risk behaviours were collected from them and were tested for HIV, Syphilis, Neisseria gonorrhoeae and Chlamydia trachomatis. RDS-weighted univariate and multivariate logistic regression analysis was performed to assess the factors associated with HIV seropositivity. Consistent condom use with regular and occasional sexual clients was 9% and 16.4%, respectively. About 25% of the participants ever used and 5.7% ever injected illicit drugs. RDS adjusted HIV prevalence was 11.6%. In the univariate analysis, factors associated with HIV were initiating sexual intercourse before the age of 15 years, ≥2 years duration of sex work, serving clients at lodge/hotel, positive test result for one or more sexually transmitted infections (STIs), lifetime history of injecting drug use, lifetime history of consuming illicit drugs, ever having exchanged sex for drugs, having sexual partners who engaged in risky injecting practices and having been widowed or divorced. In multivariate analysis, factors found to be independently associated with HIV included lifetime injecting drug use, initiating sexual intercourse before the age of 15 years, positive test result for one or more STIs and having been widowed. Injecting drug use was found to be most potent independent risk factor for HIV (OR: 3.17, CI: 1.02-9.89). Because of lower consistent condom use among them, FSWs may act as bridge for HIV transmission to general population from injecting drug users (IDU) through their sexual clients. The informations from this study may be useful for enriching the HIV preventions effort for FSWs in this region.

Syphilis among middle-aged female sex workers in China: a three-site cross-sectional study.

PubMed

Liu, Hongjie; Dumenci, Levent; Morisky, Donald E; Xu, Yongfang; Li, Xiaojing; Jiang, Baofa

2016-05-10

This study addresses the lack of empirical studies about the epidemic of syphilis among middle-aged female sex workers (FSWs). The objectives of this study were to investigate prevalence of syphilis, and its potential risk factors among middle-aged FSWs in China. A cross-sectional study with respondent-driven sampling (RDS). A multisite study conducted at three Chinese cites (Nanning, Hefei, and Qingdao) with different levels of sexually transmitted diseases in 2014. 1245 middle-aged female sex workers who were over 35 years old (about 400 per study site). Unprotected commercial sex, and syphilis and HIV infection were biologically tested and measured. The RDS-adjusted prevalence of active syphilis was 17.3% in Hefei, 9.9% in Qingdao, and 5.4% in Nanning. The RDS-adjusted prevalence of prevalent syphilis was between 6.8% and 33.6% in the three cities. The proportion of unprotected sex in the past 48 h verified by the prostate-specific antigen test (PSA) was between 27.8% and 42.4%. Multiple log-binomial regression analyses indicate that middle-aged FSWs who had 5 or more clients in the past week prior to interviews and engaged in unprotected sex were more likely to be active syphilitic cases. Middle-aged FSWs who had rural residency were less likely to be active syphilitic cases. In contrast with previous studies that reported low prevalence of syphilis and high prevalence of protected sex among FSWs in China, both the prevalence of syphilis and unprotected sex were high among middle-aged FSWs. Evidence-based intervention programmes should be developed and evaluated among this vulnerable population in China and other countries with similar settings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

HIV testing among men who have sex with men in Tijuana, Mexico: a cross-sectional study

PubMed Central

Pines, Heather A; Goodman-Meza, David; Pitpitan, Eileen V; Torres, Karla; Semple, Shirley J; Patterson, Thomas L

2016-01-01

Objectives HIV testing is critical to the delivery of comprehensive HIV prevention and care services, yet coverage of sexual minorities by HIV testing programmes remains insufficient in many low- and middle-income countries, including Mexico. The objective of this study was to identify the prevalence and correlates of HIV testing among men who have sex with men (MSM) in Tijuana, Mexico. Methods We conducted a cross-sectional study (2012–2013) among 189 MSM recruited via respondent-driven sampling (RDS). RDS-weighted logistic regression was used to identify correlates of prior HIV testing. Results RDS-adjusted prevalence of prior and recent (≤12 months) HIV testing was 63.5% (95% CI 51.9% to 73.5%) and 36.8% (95% CI 25.4% to 46.4%), respectively. Prior HIV testing was positively associated with older age (adjusted OR (AOR)=1.09, 95% CI 1.04 to 1.15), being born in Tijuana (AOR=2.68, 95% CI 1.05 to 6.86), higher levels of education (AOR=2.65, 95% CI 1.08 to 6.53), identifying as homosexual or gay (AOR=3.73, 95% CI 1.48 to 9.42), being more ‘out’ about having sex with men (AOR=1.28, 95% CI:1.02 to 1.62), and a history of sexual abuse (AOR=3.24, 95% CI 1.06 to 9.86). Prior HIV testing was negatively associated with reporting more condomless anal intercourse acts (past 2 months) (AOR=0.95, 95% CI 0.92 to 0.98) and greater internalised homophobia (AOR=0.92, 95% CI 0.86 to 0.99). Conclusions Our findings indicate an urgent need for expanded HIV testing services for MSM in Tijuana. Innovative, non-stigmatising, confidential HIV testing interventions targeted at young, less educated, migrant and non-gay identifying MSM may facilitate HIV testing and timely linkage to HIV care and treatment within this population. PMID:26846899

Heavy metal stabilization in contaminated road-derived sediments.

PubMed

Rijkenberg, Micha J A; Depree, Craig V

2010-02-01

There is increasing interest in the stabilization of heavy metals in road-derived sediments (RDS), to enable environmentally responsible reuse applications and circumvent the need for costly landfill disposal. To reduce the mobility of heavy metals (i.e. Cu, Pb and Zn) the effectiveness of amendments using phosphate, compost and fly ash addition were investigated using batch leaching experiments. In general, phosphate amendments of RDS were found to be ineffective at stabilizing heavy metals, despite being used successfully in soils. Phosphate amendment resulted in enhanced concentrations of dissolved organic carbon (DOC), which increased the solubilisation of heavy metals via complexation. Amendment with humified organic matter (compost) successfully stabilized Cu and Pb in high DOC leaching RDS with an optimum loading of 15-20% (w/w). Compost, however, was ineffective at stabilizing Zn. Increasing the pH by amending RDS/compost blends with 2.5-15% (w/w) coal fly ash resulted in the stabilization of Zn, Cu and Pb. However, above a pH of approximately 7.5 and 8 enhanced leaching of organic matter resulted in an increase in leached Cu and Pb, respectively. Accordingly, the optimum level of fly ash amendment for the RDS/compost blends was estimated to be ca. 10%. Boosted regression trees analysis (BRT) of the data revealed that DOC accounted for 56% and 65% of the Cu and Pb leaching, respectively, whereas pH only accounted for ca. 18% of Cu and Pb leaching. RDS sample characteristics (i.e. metal concentrations, size fractionation and organic matter content) were more important at reconciling the leaching concentrations of copper Cu (27%) than Pb (16%). The most important parameter explaining Zn leaching was pH. Overall, the choice of a suitable stabilization agent/s depends on the composition of RDS with respect to the amount of organic matter present, and the sorption chemistry of the heavy metal of interest. Copyright 2009 Elsevier B.V. All rights reserved.

Effects of autoclave sterilization on properties of dental rubber dam as related to its use as barrier membrane in guided tissue regeneration.

PubMed

Apinhasmit, Wandee; Limsombutanon, Somchai; Swasdison, Somporn; Suppipat, Nophadol

2003-10-01

Dental rubber dams (RDs) were used as barrier membranes in guided tissue regeneration for the treatment of periodontal intraosseous defects with acceptable clinical results. The aim of the present study was to investigate the effects of autoclave sterilization on properties of RD as related to its use as a barrier membrane in guided tissue regeneration. RDs were sterilized by either an autoclave, gamma irradiation, or chemical agents and then co-cultured with human gingival fibroblasts. The cell responses to sterilized RDs were investigated by inverted phase contrast microscopy, scanning electron microscopy (SEM) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) technique. The surface alterations of the autoclaved RDs were observed under SEM. The tensile strength, tear strength and elongation at break of the autoclaved RDs were tested by a universal testing machine. The results from cell culture, microscopic and MTT studies showed that RDs sterilized by autoclave and gamma irradiation did not deteriorate gingival fibroblasts and provided surfaces suitable for cell attachment, whereas chemical-sterilized RDs were toxic to these cells. Ultrastructurally, surface changes from the non-autoclaved RDs, including some melted areas, small pores and folds were observed on the autoclaved RD surface. The tensile strength and tear strength of the autoclaved RDs were significantly lower than those of the non-autoclaved RDs (p = 0.042, p < 0.001, respectively). In contrast, the elongation at break of the autoclaved RDs was higher than that of the non-autoclaved RDs (p < 0.001). These results suggest that the autoclave sterilization deteriorated the physical properties of RDs even though they seemed to be compatible to the cultured human cells. Therefore, the sterilization method should be taken into consideration when RDs are utilized as barrier membranes.

A Comparative Content Analysis of Vegetarian Food Blogs Written by Registered Dietitians and Non-Registered Dietitians.

PubMed

Dumas, Audrée-Anne; Lemieux, Simone; Lapointe, Annie; Dugrenier, Marilyn; Desroches, Sophie

2017-06-01

This purpose of this study was to compare the nutritional content of vegetarian recipes published in food blogs written by registered dietitians (RDs) and by non-registered dietitians (non-RDs). Twelve food blogs written by RDs and 12 written by non-RDs were selected using a systematic approach. For each food blog, 2 vegetarian entrée recipes per season were selected (n = 192 recipes). Descriptive analyses were performed using Fisher's exact test. Median nutritional values per serving between RDs' and non-RDs' recipes were compared using Wilcoxon-Mann-Whitney tests. RDs' recipes were significantly lower in energy, non-heme iron, vitamin C, and sodium, contained significantly more vitamin D and had a higher protein proportion than non-RDs' recipes. Disparities were also observed across type of entrée and vegetarian dietary pattern. In conclusion, this study showed that RD and non-RD food bloggers provided vegetarian recipes with few nutritional differences. Whether expanding the comparative analysis between RDs and non-RDs' blogs targeting different nutrition-related topics would yield different results remains to be investigated.

Evaluating Respondent-Driven Sampling as an Implementation Tool For Universal Coverage of Antiretroviral Studies among Men who have Sex with Men Living with HIV

PubMed Central

Baral, Stefan D.; Ketende, Sosthenes; Schwartz, Sheree; Orazulike, Ifeanyi; Ugoh, Kelechi; Peel, Sheila; Ake, Julie; Blattner, William; Charurat, Manhattan

2015-01-01

Introduction The TRUST model based on experimental and observational data posits that integration of HIV prevention and universal coverage of antiretroviral treatment (UCT) at a trusted community venue provides a framework for achieving effective reduction in HIV-related morbidity and mortality among men who have sex with men (MSM) living with HIV as well as reducing HIV incidence. The analyses presented here evaluate the utility of respondent-driven sampling (RDS) as an implementation tool for engaging MSM in the TRUST intervention. Methods The TRUST integrated prevention and treatment model was established at a trusted community center serving MSM in Abuja Nigeria. Five seeds have resulted in 3–26 waves of accrual between March, 2013 and August, 2014 with results presented here characterizing HIV burden and engagement in HIV care for 722 men across study recruitment waves. For analytic purposes, the waves were collapsed into five groups; four equally spaced (0–4, 5–9, 10–14, 15–19) and one ranging from the 20 to the 26th wave with significance assessed using Pearson’s chi-squared test. Results In earlier waves, MSM were more likely to have reported testing for HIV (82.9% in waves 0–4, 47.7% in waves 20–26, p<0.01). In addition, biologically-confirmed HIV prevalence decreased from an average of 59.1 to 42.9% (p<0.05) in later waves. In earlier waves, about 80% of participants correctly reported their HIV status as compared to less than 25% in the later waves (p<0.01). Lastly, participants reporting being on ART decreased from 50% to 22.2 % in later waves (p<0.01). Conclusions Implementation science studies focused on demonstrating impact of universal HIV-treatment programs among people living with HIV necessitate different accrual methods than those focused on preventing HIV acquisition. Here, RDS was shown to be an efficient method for reaching marginalized populations of MSM living with HIV in Nigeria and engaging them in universal HIV treatment services. PMID:25723974

Screening for mutations in rhodopsin and peripherin/RDS in patients with autosomal dominant retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodriguez, J.A.; Gannon, A.M.; Daiger, S.P.

1994-09-01

Mutations in rhodopsin account for approximately 30% of all cases of autosomal dominant retinits pigmentosa (adRP) and mutations in peripherin/RDS account for an additional 5% of cases. Also, mutations in rhodopsin can cause autosomal recessive retinitis pigmentosa and mutations in peripherin/RDS can cause dominant macular degeneration. Most disease-causing mutations in rhodopsin and peripherin/RDS are unique to one family or, at most, to a few families within a limited geographic region, though a few mutations are found in multiple, unrelated families. To further determine the spectrum of genetic variation in these genes, we screened DNA samples from 134 unrelated patients withmore » retinitis pigmentosa for mutations in both rhodopsin and peripherin/RDS using SSCP followed by genomic sequencing. Of the 134 patients, 86 were from families with apparent adRP and 48 were either isolated cases or were from families with an equivocal mode of inheritance. Among these patients we found 14 distinct rhodopsin mutations which are likely to cause retinal disease. Eleven of these mutations were found in one individual or one family only, whereas the Pro23His mutation was found in 14 {open_quotes}unrelated{close_quotes}individuals. The splice-site mutation produces dominant disease though with highly variable expression. Among the remaining patients were found 6 distinct peripherin/RDS mutations which are likely to cause retinal disease. These mutations were also found in one patient or family only, except the Gly266Asp mutation which was found in two unrelated patients. These results confirm the expected frequency and broad spectrum of mutations causing adRP.« less

Differing identities, but comparably high HIV and bacterial sexually transmitted disease burdens, among married and unmarried men who have sex with men in Mumbai, India

PubMed Central

Mayer, Kenneth H.; Gangakhedkar, Raman; Sivasubramanian, Murugesan; Biello, Katie B.; Abuelezam, Nadia; Mane, Sandeep; Risbud, Arun; Anand, Vivek; Safren, Steven; Mimiaga, Matthew J.

2015-01-01

Background Although HIV incidence has declined in India, men and transgender women who have sex with men (MSM) continue to have high rates of HIV and STD. Indian MSM face substantial pressures to marry and have families, but the HIV/STD burden among married Indian MSM is not well-characterized. Methods A diverse sample of Indian MSM was recruited through respondent driven sampling (RDS). Independent variables that produced a p-value of 0.10 or less were then added to a multivariable logistic regression model. Results Most of the 307 MSM (95 married, and 212 unmarried) recruited into the study were less than 30, and less than 1/3 had more than a high school education. Almost two thirds of the married men had children, compared to 1.4% of the unmarried men (p<0.001). The numbers of condomless anal sex acts did not differ by marriage status. Although unmarried MSM more often identified themselves as “kothi” (receptive role), their rates of HIV or bacterial STD were similar to married MSM, with 14.3% being HIV-infected. The RDS-adjusted prevalence of any bacterial STD was 18.3% for married MSM and 20% for unmarried MSM (NS). Participants reported high levels of psychological distress, with 27.4% of married and 20.1% of unmarried MSM reporting depressive symptoms (NS). Conclusions MSM in Mumbai had high rates of HIV, STD and behavioral health concerns. Clinicians need to become more comfortable in eliciting sexual histories so that they can identify MSM who need HIV/STD treatment and/or prevention services. PMID:26462187

Reduction of non-point source contaminants associated with road-deposited sediments by sweeping.

PubMed

Kim, Do-Gun; Kang, Hee-Man; Ko, Seok-Oh

2017-09-19

Road-deposited sediments (RDS) on an expressway, residual RDS collected after sweeping, and RDS removed by means of sweeping were analyzed to evaluate the degree to which sweeping removed various non-point source contaminants. The total RDS load was 393.1 ± 80.3 kg/km and the RDS, residual RDS, and swept RDS were all highly polluted with organics, nutrients, and metals. Among the metals studied, Cu, Zn, Pb, Ni, Ca, and Fe were significantly enriched, and most of the contaminants were associated with particles within the size range from 63 μm to 2 mm. Sweeping reduced RDS and its associated contaminants by 33.3-49.1% on average. We also measured the biological oxygen demand (BOD) of RDS in the present work, representing to our knowledge the first time that this has been done; we found that RDS contains a significant amount of biodegradable organics and that the reduction of BOD by sweeping was higher than that of other contaminants. Significant correlations were found between the contaminants measured, indicating that the organics and the metals originated from both exhaust and non-exhaust particles. Meanwhile, the concentrations of Cu and Ni were higher in 63 μm-2 mm particles than in smaller particles, suggesting that some metals in RDS likely exist intrinsically in particles, rather than only as adsorbates on particle surfaces. Overall, the results in this study showed that sweeping to collect RDS can be a good alternative for reduction of contaminants in runoff.

Professional involvement is associated with increased job satisfaction among dietitians.

PubMed

Mortensen, Jenny K; Nyland, Nora K; Fullmer, Susan; Eggett, Dennis L

2002-10-01

This study explored a relationship between professional involvement and job satisfaction among dietitians. A random sample of 2,600 employed registered dietitians (RDs) received a 55-item questionnaire including a standardized measure of job satisfaction. The response rate was 67.3%; 50.8% were useable (n = 1,321). Ninety-two percent of RDs reported job satisfaction. The mean score was 68.8 +/- .28 (possible range: 18-90), with scores over 54 indicating job satisfaction. A positive relationship was found between job satisfaction and markers of professional involvement. Additionally, six characteristics related to professional involvement were: having had a mentor, being a mentor, self-assessed high professional involvement, full-time employment, high annual income, and increased hours worked per week. There was also a positive relationship between markers of professional involvement and employer support. We conclude that, overall, RDs are satisfied with their jobs and that greater professional involvement is related to greater job satisfaction.

High prevalence of latent tuberculosis infection among injection drug users in Tijuana, Mexico.

PubMed

Garfein, R S; Lozada, R; Liu, L; Laniado-Laborin, R; Rodwell, T C; Deiss, R; Alvelais, J; Catanzaro, A; Chiles, P G; Strathdee, S A

2009-05-01

We studied prevalence and correlates of latent tuberculosis infection (LTBI) among injection drug users (IDUs) in Tijuana, Mexico, where tuberculosis (TB) is endemic. IDUs aged > or =18 years were recruited via respondent-driven sampling (RDS) and underwent standardized interviews, human immunodeficiency virus (HIV) antibody testing and LTBI screening using Quanti-FERON((R))-TB Gold In-Tube, a whole-blood interferon-gamma release assay (IGRA). LTBI prevalence was estimated and correlates were identified using RDS-weighted logistic regression. Of 1020 IDUs, 681 (67%) tested IGRA-positive and 44 (4%) tested HIV-positive. Mean age was 37 years, 88% were male and 98% were Mexican-born. IGRA positivity was associated with recruitment nearest the US border (aOR 1.64, 95%CI 1.09-2.48), increasing years of injection (aOR 1.20/5 years, 95%CI 1.07-1.34), and years lived in Tijuana (aOR 1.10/5 years, 95%CI 1.03-1.18). Speaking some English (aOR 0.38, 95%CI 0.25-0.57) and injecting most often at home in the past 6 months (aOR 0.68, 95%CI 0.45-0.99) were inversely associated with IGRA positivity. Increased LTBI prevalence among IDUs in Tijuana appears to be associated with greater drug involvement. Given the high risk for HIV infection among Tijuana's IDUs, interventions are urgently needed to prevent HIV infection and treat LTBI among IDUs before these epidemics collide.

Homosexuality-related stigma and sexual risk behaviors among men who have sex with men in Hanoi, Vietnam.

PubMed

Ha, Huy; Risser, Jan M H; Ross, Michael W; Huynh, Nhung T; Nguyen, Huong T M

2015-02-01

This article examined the associations between three forms of homosexuality-related stigma (enacted, perceived, and internalized homosexual stigmas) with risky sexual behaviors, and to describe the mechanisms of these associations, among men who have sex with men (MSM) in Hanoi, Vietnam. We used respondent-driven sampling (RDS) to recruit 451 MSM into a cross-sectional study conducted from August 2010 to January 2011. Data were adjusted for recruitment patterns due to the RDS approach; logistic regression and path analyses were performed. Participants were young and single; most had attended at least some college. Nine out of ten participants engaged in sexual behaviors at moderate to high risk levels. Compared to those who had no enacted homosexual stigma, men having low and high levels of enacted homosexual stigma, respectively, were 2.23 times (95 % CI 1.35-3.69) and 2.20 times (95 % CI 1.04-4.76) more likely to engage in high levels of sexual risk behaviors. In addition, there was an indirect effect of perceived homosexual stigma and internalized homosexual stigma on sexual risk behaviors through depression and drug and alcohol use. Our study provides valuable information to our understanding of homosexual stigma in Vietnam, highlighting the need for provision of coping skills against stigma to the gay community and addressing drinking and drug use among MSM, to improve the current HIV prevention interventions in Vietnam.

Adolescent Sexual Debut and Initiation into New-Type Drug Use among a Sample of Young Adults

PubMed Central

Ding, Yingying; He, Na; Detels, Roger

2017-01-01

We examined the association between adolescent sexual debut and age at new-type drug initiation among a sample of young adult new-type drug users. A total of 276 participants were recruited using respondent-driven sampling (RDS) in Shanghai, China. The analyses were restricted to a total of 201 participants aged between 18 and 30 years. The average age at sexual debut and age at first new-type drug use were 18.8 and 20.9 years, respectively. About 94% of participants reported having sexual experience (n = 188); of those, 137 (72.9%) had sexual debut before they first used new-type drugs, while 32 (17.0%) initiated both events at the same age. After adjustment for age, income, education, and sexual orientation, adolescent sexual debut was independently associated with younger age at new-type drug initiation. Adolescent sexual debut is associated with early onset of new-type drug use. Our findings underscore the importance of implementing sex-education programs for adolescents in schools in China. PMID:26098832

Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets.

PubMed

Luo, Guobin; Xu, Wenbin; Yang, Jinshan; Li, Yang; Zhang, Liyang; Wang, Yizhen; Lin, Cong; Zhang, Yonggen

2017-05-01

This trial was performed to examine the effects of ruminally degradable starch (RDS) levels in total mixed ration (TMR) with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Eight multiparous Holstein cows (body weight [BW]: 717±63 kg; days in milk [DIM]: 169±29) were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS) or 72.1% ruminally degradable starch (% of total starch, high RDS). Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

Microfloral diversity in the lower respiratory tracts of neonates with bacterial infectious pneumonia combined with ventilator‑associated pneumonia.

PubMed

Lu, Wei; Yu, Jia-Lin; Li, Lu-Quan; Lu, Qi; Wang, Zheng-Li; Pan, Yun

2016-12-01

Bacterial infectious pneumonia is one of the major causes of mortality in neonates, particularly when the neonates suffer from ventilator‑associated pneumonia (VAP). However, the causes of pneumonia are difficult to define. Thus, the present study focused on understanding the diversity of microflora in the lower respiratory tract to elucidate the causes. The experimental groups comprised newborns who suffered from infectious pneumonia with or without VAP (IVAP and IP groups, respectively), whereas the control group comprised newborns who suffered from respiratory distress syndrome (RDS) without VAP (RDS group). Following 1, 3 and 5 days of ventilation, sputum samples were collected and the DNA was extracted. The DNA was amplified and separated, and the 16S rDNA was then sequenced and analyzed for diversity. The results of the diversity and Shannon‑Wiener indices were ordered as follows: IVAP group < IP group < RDS group. The percentages of Streptococcus sp., Serratia sp. and Achromobacter sp. in the IP and IVAP groups were higher, compared with those in the RDS group, whereas the percentages of Klebsiella sp. and Acinetobacter sp. were lower on day 1. The percentages of Klebsiella sp. and Streptococcus sp. on days 1 and 3 were ordered as follows: IVAP group > IP group > RDS group, and the percentages of Serratia sp., Acinetobacter sp. and Achromobacter sp. were ordered as follows: IVAP group < IP group < RDS group. After 3‑5 days, the percentages of Klebsiella sp., Acinetobacter sp., Streptococcus sp., Serratia sp. and Achromobacter sp. in the IVAP group were lower, compared with those in the RDS and IP groups. It was concluded that the decreased microfloral diversity, increased constituent ratios of Klebsiella sp. and Streptococcus sp., and decreased ratios of Serratia sp. and Acinetobacter sp. in the lower respiratory tract of neonates suffering from pneumonia may be indicators of VAP.

Evidence of early systemic activation and transendothelial migration of neutrophils in neonates with severe respiratory distress syndrome.

PubMed

Sarafidis, K; Drossou-Agakidou, V; Kanakoudi-Tsakalidou, F; Taparkou, A; Tsakalidis, C; Tsandali, C; Kremenopoulos, G

2001-03-01

Several observations imply that the early inflammatory response involving activated neutrophils, tissue macrophages, and cytokines plays an important role in the pathogenesis of neonatal respiratory distress syndrome (RDS) and progression to bronchopulmonary dysplasia (BPD). The aim of this study was to test the hypothesis that changes in circulating neutrophil number and function and plasma levels of cytokines, consistent with neutrophil activation and migration to the tissues, occur during the early stages of neonatal RDS. For this purpose we measured peripheral blood levels of certain immunological parameters that promote neutrophil activation and transendothelial migration. Twenty preterm neonates with severe RDS and 20 healthy infants matched for gestational age were the subjects. The absolute neutrophil count (ANC), and plasma levels of interleukin-6 (IL-6), granulocyte colony-stimulating factor (G-CSF), and sL-selectin using an enzyme-linked immunosorbent assay (ELISA), neutrophil CD11b expression, and respiratory burst activity (RBA) using flow cytometry, were measured within 24 h after birth. The two groups were comparable regarding perinatal characteristics. None of the neonates studied had any clinical or laboratory evidence of infection by the time of blood sampling. The immunological investigation showed that the RDS neonates had significantly lower ANC (P = 0.032), higher expression of the CD11b on neutrophils (P = 0.0065), and higher G-CSF and IL-6 plasma levels (P = 0.0047 and P < 0.0001, respectively) in comparison to healthy preterm neonates. The neutrophil RBA and plasma sL-selectin levels did not differ significantly between the two groups. We conclude that in neonates with severe RDS, there is evidence of a systemic neutrophil activation early in the course of the disease, supporting the view of a contributing role of activated neutrophils in the pathogenesis of RDS. Copyright 2001 Wiley-Liss, Inc.

HIV testing among men who have sex with men in Tijuana, Mexico: a cross-sectional study.

PubMed

Pines, Heather A; Goodman-Meza, David; Pitpitan, Eileen V; Torres, Karla; Semple, Shirley J; Patterson, Thomas L

2016-02-04

HIV testing is critical to the delivery of comprehensive HIV prevention and care services, yet coverage of sexual minorities by HIV testing programmes remains insufficient in many low- and middle-income countries, including Mexico. The objective of this study was to identify the prevalence and correlates of HIV testing among men who have sex with men (MSM) in Tijuana, Mexico. We conducted a cross-sectional study (2012-2013) among 189 MSM recruited via respondent-driven sampling (RDS). RDS-weighted logistic regression was used to identify correlates of prior HIV testing. RDS-adjusted prevalence of prior and recent (≤ 12 months) HIV testing was 63.5% (95% CI 51.9% to 73.5%) and 36.8% (95% CI 25.4% to 46.4%), respectively. Prior HIV testing was positively associated with older age (adjusted OR (AOR)=1.09, 95% CI 1.04 to 1.15), being born in Tijuana (AOR=2.68, 95% CI 1.05 to 6.86), higher levels of education (AOR=2.65, 95% CI 1.08 to 6.53), identifying as homosexual or gay (AOR=3.73, 95% CI 1.48 to 9.42), being more 'out' about having sex with men (AOR=1.28, 95% CI:1.02 to 1.62), and a history of sexual abuse (AOR=3.24, 95% CI 1.06 to 9.86). Prior HIV testing was negatively associated with reporting more condomless anal intercourse acts (past 2 months) (AOR=0.95, 95% CI 0.92 to 0.98) and greater internalised homophobia (AOR=0.92, 95% CI 0.86 to 0.99). Our findings indicate an urgent need for expanded HIV testing services for MSM in Tijuana. Innovative, non-stigmatising, confidential HIV testing interventions targeted at young, less educated, migrant and non-gay identifying MSM may facilitate HIV testing and timely linkage to HIV care and treatment within this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Risk assessment of metals in road-deposited sediment along an urban-rural gradient.

PubMed

Zhao, Hongtao; Li, Xuyong

2013-03-01

We applied the traditional risk assessment methods originally designed for soils and river sediments to evaluation of risk associated with metals in road-deposited sediment (RDS) along an urban-rural gradient that included central urban (UCA), urban village (UVA), central suburban county (CSA), rural town (RTA), and rural village (RVA) areas in the Beijing metropolitan region. A new indicator RI(RDS) was developed which integrated the RDS characteristics of mobility, grain size and amount with the potential ecological risk index. The risk associated with metals in RDS in urban areas was generally higher than that in rural areas based on the assessment using traditional methods, but the risk was higher in urban and rural village areas than the areas with higher administration units based on the indicator RI(RDS). These findings implied that RDS characteristics variation with the urban-rural gradient must be considered in metal risk assessment and RDS washoff pollution control. Copyright © 2012 Elsevier Ltd. All rights reserved.

In Vitro Starch Digestibility of Commercial Gluten-Free Pasta: The Role of Ingredients and Origin.

PubMed

Marti, Alessandra; Abbasi Parizad, Parisa; Marengo, Mauro; Erba, Daniela; Pagani, Maria Ambrogina; Casiraghi, Maria Cristina

2017-04-01

Gluten replacement in gluten-free (GF) products presents major challenges for the food industry in terms of sensorial, technological and nutritional characteristics. The absence of gluten reportedly affects starch digestibility, thus increasing the postprandial glycaemic response. However, the role of ingredients and processing conditions has been addressed only seldom. We investigated the in vitro starch digestibility of 9 commercial GF products (5 Italian pasta and 4 Oriental noodles) differing in formulation and processing conditions. Content of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) were assessed and combined with information on starch pasting properties and on the overall protein organization. Oriental noodles presented higher relative levels of RS and RDS than Western-style pasta, that often had SDS levels compatible with low rates of starch digestion. As regard formulation, presence of multiple ingredients seems to likely increase the RDS level, as did the different protein organization in the various samples. © 2017 Institute of Food Technologists®.

PHYSICAL CONDITIONS OF CORONAL PLASMA AT THE TRANSIT OF A SHOCK DRIVEN BY A CORONAL MASS EJECTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Susino, R.; Bemporad, A.; Mancuso, S., E-mail: susino@oato.inaf.it

2015-10-20

We report here on the determination of plasma physical parameters across a shock driven by a coronal mass ejection using white light (WL) coronagraphic images and radio dynamic spectra (RDS). The event analyzed here is the spectacular eruption that occurred on 2011 June 7, a fast CME followed by the ejection of columns of chromospheric plasma, part of them falling back to the solar surface, associated with a M2.5 flare and a type-II radio burst. Images acquired by the Solar and Heliospheric Observatory/LASCO coronagraphs (C2 and C3) were employed to track the CME-driven shock in the corona between 2–12 R{submore » ⊙} in an angular interval of about 110°. In this interval we derived two-dimensional (2D) maps of electron density, shock velocity, and shock compression ratio, and we measured the shock inclination angle with respect to the radial direction. Under plausible assumptions, these quantities were used to infer 2D maps of shock Mach number M{sub A} and strength of coronal magnetic fields at the shock's heights. We found that in the early phases (2–4 R{sub ⊙}) the whole shock surface is super-Alfvénic, while later on (i.e., higher up) it becomes super-Alfvénic only at the nose. This is in agreement with the location for the source of the observed type-II burst, as inferred from RDS combined with the shock kinematic and coronal densities derived from WL. For the first time, a coronal shock is used to derive a 2D map of the coronal magnetic field strength over intervals of 10 R{sub ⊙} altitude and ∼110° latitude.« less

Resin duct size and density as ecophysiological traits in fire scars of Pseudotsuga menziesii and Larix occidentalis.

PubMed

Arbellay, Estelle; Stoffel, Markus; Sutherland, Elaine K; Smith, Kevin T; Falk, Donald A

2014-10-01

Resin ducts (RDs) are features present in most conifer species as defence structures against pests and pathogens; however, little is known about RD expression in trees following fire injury. This study investigates changes in RD size and density in fire scars of Douglas fir (Pseudotsuga menziesii) and western larch (Larix occidentalis) as a means to evaluate the ecophysiological significance of traumatic resinosis for tree defence and survival. Transverse and tangential microsections were prepared for light microscopy and image analysis in order to analyse axial and radial RDs, respectively. Epithelial cells of RDs and fusiform rays associated with radial RDs were also examined. RDs were compared between normal xylem and wound xylem at four different section heights along the fire-injured stem. Following fire injury, P. menziesii axial RDs narrowed by 38-43 % in the first year after injury, and the magnitude of this change increased with stem height. Larix occidentalis axial RDs widened by 46-50 % in the second year after injury. Radial RDs were of equivalent size in P. menziesii, but widened by 162-214 % in L. occidentalis. Fusiform rays were larger following fire injury, by 4-14 % in P. menziesii and by 23-38 % in L. occidentalis. Furthermore, axial RD density increased in both species due to the formation of tangential rows of traumatic RDs, especially in the first and second years after injury. However, radial RD density did not change significantly. These results highlight traumatic resinosis as a species-specific response. Pseudotsuga menziesii produce RDs of equivalent or reduced size, whereas L. occidentalis produce wider RDs in both the axial and radial duct system, thereby increasing resin biosynthesis and accumulation within the whole tree. Larix occidentalis thus appears to allocate more energy to defence than P. menziesii. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Prevalence and Determinants of Adolescent Pregnancy in Urban, Disadvantaged Settings across Five Cities

PubMed Central

Brahmbhatt, Heena; Kågesten, Anna; Emerson, Mark; Decker, Michele; Olumide, Adesolu; Ojengbede, Oladosu; Chaohua, Lou; Sonenstein, Freya; Blum, Robert; Delany-Moretlwe, Sinead

2015-01-01

Background The impact of pregnancy on the health and livelihood of adolescents aged 15–19 is substantial. This study explored sociodemographic, behavioral and environmental-level factors associated with adolescent pregnancy across 5 urban disadvantaged settings. Methods The Well Being of Adolescents in Vulnerable Environments study used Respondent Driven Sampling (RDS) to recruit males and females from Baltimore (456), Johannesburg (496), Ibadan (449), Delhi (500) and Shanghai(438). RDS-II and post-stratification age weights were used to explore the odds associated with “ever had sex” and “ever pregnant”; adjusted odds of pregnancy and 95% CI were developed by site and gender. Results Among the sexually experienced, pregnancy was most common in Baltimore (females 53%, males 25%) and Johannesburg (females 29%, males 22%). Heterosexual experience and therefore pregnancy were rare in Ibadan, Delhi and Shanghai. Current schooling and condom use at first sex decreased the odds of pregnancy among females in Baltimore and Johannesburg participants. Factors associated with higher odds of pregnancy were: early sexual debut (Johannesburg participants, Baltimore females) being raised by someone other than 2 parents (Johannesburg females); alcohol use and binge drinking in the past month (Baltimore participants); greater community violence and poor physical environment (Baltimore males, Johannesburg participants). Conclusions The reported prevalence of adolescent pregnancy varies substantially across similarly economically disadvantaged urban settings. These differences are related to large differences in sexual experience, which may be underreported, as well as differences in environmental contexts. Pregnancy risk needs to be understood within the specific context that adolescents reside, with particular attention to neighborhood-level factors. PMID:25454003

Prevalence and correlates of HIV among men who have sex with men in Tijuana, Mexico.

PubMed

Pitpitan, Eileen V; Goodman-Meza, David; Burgos, Jose Luis; Abramovitz, Daniela; Chavarin, Claudia V; Torres, Karla; Strathdee, Steffanie A; Patterson, Thomas L

2015-01-01

Men who have sex with men (MSM) in developing countries such as Mexico have received relatively little research attention. In Tijuana, Mexico, a border city experiencing a dynamic HIV epidemic, data on MSM are over a decade old. Our aims were to estimate the prevalence and examine correlates of HIV infection among MSM in this city. We conducted a cross-sectional study of 191 MSM recruited through respondent-driven sampling (RDS) in 2012. Biological males over the age of 18 who resided in Tijuana and reported sex with a male in the past year were included. Participants underwent interviewer-administered surveys and rapid tests for HIV and syphilis with confirmation. A total of 33 MSM tested positive for HIV, yielding an RDS-adjusted estimated 20% prevalence. Of those who tested positive, 89% were previously unaware of their HIV status. An estimated 36% (95% CI: 26.4-46.5) had been tested for HIV in the past year, and 30% (95% CI: 19.0-40.0) were estimated to have ever used methamphetamine. Independent correlates of being infected with HIV were methamphetamine use (odds ratio [OR] = 2.24, p = 0.045, 95% CI: 1.02, 4.92) and active syphilis infection (OR = 4.33, p = 0.01, 95% CI: 1.42, 13.19). Our data indicate that MSM are a key sub-population in Tijuana at higher risk for HIV. Tijuana would also appear to have the highest proportion among upper-middle-income countries of HIV-positive MSM who are unknowingly infected. More HIV prevention research on MSM is urgently needed in Tijuana.

Effect of birth order on neonatal morbidity and mortality among very low birthweight twins: a population based study

PubMed Central

Shinwell, E; Blickstein, I; Lusky, A; Reichman, B

2004-01-01

Objective: To study the effect of birth order on the risk for respiratory distress syndrome (RDS), chronic lung disease (CLD), adverse neurological findings, and death in very low birthweight (VLBW; < 1500 g) twins. Methods: A population based study of VLBW infants from the Israel National VLBW Infant Database. The sample included all complete sets of VLBW twin pairs admitted to all 28 neonatal intensive care units between 1995 and 1999. Outcome variables were compared by birth order and stratified by mode of delivery and gestational age, using General Estimating Equation models, with results expressed as odds ratio (OR) with 95% confidence interval (CI). Results: Second twins were at increased risk for RDS (OR 1.51, 95% CI 1.29 to 1.76), CLD (OR 1.36, 95% CI 1.11 to 1.66), and death (OR 1.24, 95% CI 1.02 to 1.51) but not for adverse neurological findings (OR 1.20, 95% CI 0.91 to 1.60). Mode of delivery did not significantly influence outcome. The odds ratio for RDS in the second twin was inversely related to gestational age, and the increased risk for RDS and CLD was found in both vaginal and caesarean deliveries. Conclusions: VLBW second twins are at increased risk for acute and chronic lung disease and neonatal mortality, irrespective of mode of delivery. PMID:14977899

Substance Use over the Military-Veteran Life Course: An Analysis of a Sample of OEF/OIF Veterans Returning to Low-Income Predominately Minority Communities

PubMed Central

Golub, Andrew; Bennett, Alex S.

2013-01-01

This paper presents an overview of substance use patterns of recent veterans returning to low-income predominately minority communities over four periods of the military-veteran career. Respondent driven sampling (RDS) was used so that unbiased estimates could be obtained for the characteristics of the target population. The majority of participants had used marijuana but no other illegal drugs. In the military, marijuana use was substantially lower and alcohol was the drug of choice; the majority were binge drinkers and nearly half were heavy drinkers. While deployed, alcohol and marijuana use were both lower, though some participants (6%) initiated the misuse of prescription painkillers. After separating from the military and returning to civilian life, heavy drinking was much lower, marijuana use increased, and some veterans misused prescription painkillers (7%). Further research based on these data will examine these distinct periods of substance use, contexts of use, related substance and mental health problems, treatment use and avoidance, and civilian reintegration. PMID:23932708

Factors associated with HIV testing among young men who have sex with men in Myanmar: a cross-sectional study.

PubMed

Pham, Minh D; Aung, Poe Poe; Paing, Aye Kyawt; Pasricha, Naanki; Agius, Paul A; Tun, Waimar; Bajracharya, Ashish; Luchters, Stanley

2017-11-01

In Myanmar, men who have sex with men (MSM) experience high risk of HIV infection. However, access to HIV testing and prevention services remains a challenge among this marginalized population. The objective of this study was to estimate population prevalence and correlates of prior HIV testing among young MSM (YMSM) and informs the development of HIV testing and intervention programmes that respond to the specific needs of this population. Five hundred and eighty-five YMSM aged 18 to 24 years were recruited using respondent-driven sampling (RDS) in a cross-sectional survey conducted in six townships of Myanmar. RDS-adjusted population estimates were calculated to estimate prevalence of HIV testing; RDS-weighted logistic regression was used to examine correlates of HIV testing in the past 6 months and in a lifetime. There were 12 participants who reported receiving a HIV-positive test; of those, five were tested in the past 6 months. The RDS-weighted prevalence estimates of lifetime (any prior) HIV testing was 60.6% (95% CI: 53.3% to 66.4%) and of recent (≤ 6 months) HIV testing was 50.1% (95% CI: 44.1% to 55.5%). In multivariable analysis, sexual identity was associated with lifetime but not recent HIV testing. Lifetime and recent HIV testing were associated with having three or more male sexual partners in the past 12 months (adjusted ORs (aORs) = 2.28, 95% CIs: 1.21 to 4.32 and 2.69, 95% CI: 1.59 to 4.56), having good HIV-related knowledge (aORs = 1.96, 95% CIs: 1.11 to 3.44 and 1.77, 95% CI: 1.08 to 2.89), reporting high HIV testing self-efficacy (aORs = 13.5, 95% CIs: 6.0 to 30.1 and 9.81, 95% CI: 4.27 to 22.6) and having access to and use of non-HIV health-related services in the past 12 months (aORs = 13.2, 95% CIs: 6.85 to 25.6 and 7.15, 95% CI: 4.08 to 12.5) respectively. HIV testing coverage among YMSM aged 18 to 24 years old in Myanmar is still suboptimal. Integrated HIV testing and prevention services in existing health service provision systems with tailored HIV information and education programmes targeting YMSM to improve HIV-related knowledge and self-efficacy may help to promote regular HIV testing behaviour and contribute to sustainable control of the HIV epidemic among this marginalized population in Myanmar. © 2017 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

The Probability of Neonatal Respiratory Distress Syndrome as a Function of Gestational Age and Lecithin/Sphingomyelin Ratio

PubMed Central

St. Clair, Caryn; Norwitz, Errol R.; Woensdregt, Karlijn; Cackovic, Michael; Shaw, Julia A.; Malkus, Herbert; Ehrenkranz, Richard A.; Illuzzi, Jessica L.

2011-01-01

We sought to define the risk of neonatal respiratory distress syndrome (RDS) as a function of both lecithin/sphingomyelin (L/S) ratio and gestational age. Amniotic fluid L/S ratio data were collected from consecutive women undergoing amniocentesis for fetal lung maturity at Yale-New Haven Hospital from January 1998 to December 2004. Women were included in the study if they delivered a live-born, singleton, nonanomalous infant within 72 hours of amniocentesis. The probability of RDS was modeled using multivariate logistic regression with L/S ratio and gestational age as predictors. A total of 210 mother-neonate pairs (8 RDS, 202 non-RDS) met criteria for analysis. Both gestational age and L/S ratio were independent predictors of RDS. A probability of RDS of 3% or less was noted at an L/S ratio cutoff of ≥3.4 at 34 weeks, ≥2.6 at 36 weeks, ≥1.6 at 38 weeks, and ≥1.2 at term. Under 34 weeks of gestation, the prevalence of RDS was so high that a probability of 3% or less was not observed by this model. These data describe a means of stratifying the probability of neonatal RDS using both gestational age and the L/S ratio and may aid in clinical decision making concerning the timing of delivery. PMID:18773379

Emergence of methadone as a street drug in St. Petersburg, Russia.

PubMed

Heimer, Robert; Lyubimova, Aleksandra; Barbour, Russell; Levina, Olga S

2016-01-01

The syndemic of opioid addiction, HIV, hepatitis, tuberculosis, imprisonment, and overdose in Russia has been worsened by the illegality of opioid substitution therapy. As part of on-going serial studies, we sought to explore the influence of opioid availability on aspects of the syndemic as it has affected the city of St. Petersburg. We employed a sequential approach in which quantitative data collection and statistical analysis were followed by a qualitative phase. Quantitative data were obtained in 2013-2014 from a respondent-driven sample (RDS) of people who inject drugs (PWID). Individuals recruited by RDS were tested for antibodies to HIV and interviewed about drug use and injection practices, sociodemographics, health status, and access to medical care. Subsequently, we collected in-depth qualitative data on methadone use, knowledge, and market availability from PWID recruited at nine different locations within St. Petersburg. Analysis of interview data from the sample revealed the percentage of PWID injecting methadone in the 30 days prior to interview increased from 3.6% in 2010 to 53.3% in 2012-2013. Injection of only methadone, as compared to injecting only heroin or both drugs, was associated with less frequent injection and reduced HIV-related injected risk, especially a lower rate of injecting with a previously used syringe. In-depth questioning of methadone injectors corroborated the finding from serial quantitative surveys of PWID that methadone's black market availability is a recent phenomenon. Spatial analysis revealed widespread methadone availability but no concentration in any specific districts of the city. Despite the prohibition of substitution therapy and demonization of methadone, the drug has emerged to rival heroin as the most commonly available opioid in St. Petersburg. Ironically, its use is associated with reduced injection-related HIV risk even when its use is illegal. Copyright © 2015 Elsevier B.V. All rights reserved.

Emergence of Methadone as a Street Drug in St. Petersburg, Russia

PubMed Central

Heimer, Robert; Lyubimova, Aleksandra; Barbour, Russell; Levina, Olga S.

2015-01-01

Background The syndemic of opioid addiction, HIV, hepatitis, tuberculosis, imprisonment, and overdose in Russia has been worsened by the illegality of opioid substitution therapy. As part of on-going serial studies, we sought to explore the influence of opioid availability on aspects of the syndemic as it has affected the city of St. Petersburg. Methods We employed a sequential approach in which quantitative data collection and statistical analysis were followed by a qualitative phase. Quantitative data were obtained from a respondent-driven sample (RDS) of people who inject drugs (PWID) obtained in 2012–13. Individuals recruited by RDS were tested for antibodies to HIV and interviewed about drug use and injection practices, sociodemographics, health status, and access to medical care. Subsequently, we collected in-depth qualitative data on methadone use, knowledge, and market availability from PWID recruited at nine different locations within St. Petersburg. Results Analysis of interview data from the sample revealed he percentage of PWID injecting methadone in the 30 days prior to interview increased from 3.6% in 2010 to 53.3% in 2012–13. Injection of only methadone, as compared to injecting only heroin or both drugs, was associated with less frequent injection and reduced HIV-related injected risk, especially a lower rate of injecting with a previously used syringe. In-depth questioning of methadone injectors corroborated the finding from serial quantitative surveys of PWID that methadone’s black market availability is a recent phenomenon. Spatial analysis revealed widespread methadone availability but no concentration in any specific districts of the city. Conclusion Despite the prohibition of substitution therapy and demonization of methadone, the drug has emerged to rival heroin as the most commonly available opioid in St. Petersburg. Ironically, its use is associated with reduced injection-related HIV risk even when its use is illegal. PMID:26573380

Arizona Registered Dietitians Show Gaps in Knowledge of Bean Health Benefits

PubMed Central

Thompson, Sharon V.; Dougherty, Mariah K.

2018-01-01

Registered Dietitians (RDs) promote nutrition practices and policies and can influence food consumption patterns to include nutrient dense foods such as beans. Although many evidence-based health benefits of bean consumption (e.g., cholesterol reduction, glycemic control) have been demonstrated, there is limited research on the knowledge, attitudes, and perceptions of RDs regarding the inclusion of beans in a healthy diet. To fill this existing research gap, this cross-sectional survey explored the perceptions, knowledge, and attitudes of 296 RDs in Arizona, USA, toward beans. The RDs largely held positive attitudes toward the healthfulness of beans and were aware of many health benefits. Some gaps in awareness were evident, including effect on cancer risk, intestinal health benefits, folate content, and application with celiac disease patients. RDs with greater personal bean consumption had significantly higher bean health benefit knowledge. Twenty-nine percent of the RDs did not know the meaning of ‘legume’, and over two-thirds could not define the term ‘pulse’. It is essential that RDs have up-to-date, evidence-based information regarding bean benefits to provide appropriate education to patients, clients, and the public. PMID:29316699

U.S. Army Research Laboratory Fiscal Year 2010 Status Report for the Advanced, All-Source, Fusion Technology Program Annex

DTIC Science & Technology

2011-03-01

9 Figure 7. RDS preferences widget after loading an unusual font (left) and RDS SPARQL query widget (right...Entered By Individual: SGT Juan Gonzalez DOI: 2007-01-06 13:00:00 Date Entered: 2007-01-06 23:32:03 Subject: Al-Qaeda Reading Material Source...preferences widget after loading an unusual font (left) and RDS SPARQL query widget (right). NetKernel and RDS-specific modules are specified with a URL

Correlative live and super-resolution imaging reveals the dynamic structure of replication domains.

PubMed

Xiang, Wanqing; Roberti, M Julia; Hériché, Jean-Karim; Huet, Sébastien; Alexander, Stephanie; Ellenberg, Jan

2018-06-04

Chromosome organization in higher eukaryotes controls gene expression, DNA replication, and DNA repair. Genome mapping has revealed the functional units of chromatin at the submegabase scale as self-interacting regions called topologically associating domains (TADs) and showed they correspond to replication domains (RDs). A quantitative structural and dynamic description of RD behavior in the nucleus is, however, missing because visualization of dynamic subdiffraction-sized RDs remains challenging. Using fluorescence labeling of RDs combined with correlative live and super-resolution microscopy in situ, we determined biophysical parameters to characterize the internal organization, spacing, and mechanical coupling of RDs. We found that RDs are typically 150 nm in size and contain four co-replicating regions spaced 60 nm apart. Spatially neighboring RDs are spaced 300 nm apart and connected by highly flexible linker regions that couple their motion only <550 nm. Our pipeline allows a robust quantitative characterization of chromosome structure in situ and provides important biophysical parameters to understand general principles of chromatin organization. © 2018 Xiang et al.

Interdisciplinary Discrepancies Between Parenteral Nutrition Macronutrient Prescribing and Recommendations: Is Body Mass Index a Factor?

PubMed

Elliott, Katie L; Kandiah, Jay; Walroth, Todd A

2017-07-01

Formal nutrition training in medical schools and residencies is lacking and needed. Registered dietitians (RDs) are formally trained in nutrition support and considered experts in the nutrition field. Our purpose was to examine prescribing and recommending discrepancies of parenteral nutrition macronutrients between medical residents (MRs) and RDs and compare results with the ASPEN clinical care guidelines. We also looked at discrepancies among obese patients, due to their increased risk of mortality. The primary end point of this retrospective review was discrepancies in nonprotein calories (NPCs) and grams of protein (PRO) between MRs and RDs. The secondary end point was discrepancies in NPCs and PRO between MRs and RDs among patients stratified by body mass index category. MRs prescribed 300 NPCs more versus RDs ( P < .001). When compared with RDs, MRs prescribed fewer NPCs for underweight patients and more for obese patients ( P < .001). The same analysis found that the PRO discrepancies significantly varied by body mass index classification as well ( P = .022). When these results were compared with the ASPEN clinical care guidelines, RDs adhered closer to the guidelines than did MRs in terms of permissive underfeeding of obese patients. It is widely accepted that MRs are in need of increased formal training, and the results of our study confirm this need and suggest a short-term solution of increasing order-writing privileges for the RD. RDs with this privilege may adhere more closely to clinical care guidelines and therefore increase patient safety.

The Role of Solidarity(-ies) in Rare Diseases Research.

PubMed

Mascalzoni, Deborah; Petrini, Carlo; Taruscio, Domenica; Gainotti, Sabina

2017-01-01

Solidarity plays a relevant role in rare diseases (RDs) research to create and enable research in the field. In Europe RDs are estimated to affect between 27 and 36 million people even though single RDs can count very few patients, making the contribution of everyone essential to reach solid results. Often RD research is initiated by patient groups devoting substantial time and resources to the scientific enterprise. In RD research solidarity is often evocated and expressed, in different ways and on different levels, so that it is possible to talk about "solidarities" played by different stakeholders and sometimes conflicting with each other. In this paper we describe different contexts in which solidarity is expressed and embedded in RD research, in particular the context of tight relationships between individuals and their families or in small communities/ethnic groups; among individuals suffering from different RDs and researchers working on a specific RD or a group of RDs, and within society at large. In all these cases the different types of solidarity should be balanced against each other and also against conflicting values. The request to a patient to share data and samples to increase scientific knowledge on the basis of solidarity values needs to be balanced against the need to protect her privacy and autonomy; the duty for a researcher to allow fair access to RD sample and data collections which were donated in a spirit of solidarity is balanced against the need to be competitive in the research world. In the Report "Solidarity. Reflections on an emerging concept in bioethics", the Nuffield Council of Bioethics defines solidarity as "shared practices reflecting a collective commitment to carry 'costs' (financial, social, emotional or otherwise) to assist others". Therefore, if a solidarity framework has to be solid and ethically sound it needs to be framed as a shared value, reflected in the different practices by all the stakeholders and be based on reciprocity (not one sided). The context of solidarity(ies) provides a solid base for framing the research endeavor as collectively valuable, not only for possible results of the research, but as intrinsic valid societal practice. This paper tries to draw the lessons on solidarity that we can derive from the RD world where "solidarities" have been part of the game for long time and are declined on many different levels.

Quantifying Grain-Size Variability of Metal Pollutants in Road-Deposited Sediments Using the Coefficient of Variation

PubMed Central

Wang, Xiaoxue; Li, Xuyong

2017-01-01

Particle grain size is an important indicator for the variability in physical characteristics and pollutants composition of road-deposited sediments (RDS). Quantitative assessment of the grain-size variability in RDS amount, metal concentration, metal load and GSFLoad is essential to elimination of the uncertainty it causes in estimation of RDS emission load and formulation of control strategies. In this study, grain-size variability was explored and quantified using the coefficient of variation (Cv) of the particle size compositions, metal concentrations, metal loads, and GSFLoad values in RDS. Several trends in grain-size variability of RDS were identified: (i) the medium class (105–450 µm) variability in terms of particle size composition, metal loads, and GSFLoad values in RDS was smaller than the fine (<105 µm) and coarse (450–2000 µm) class; (ii) The grain-size variability in terms of metal concentrations increased as the particle size increased, while the metal concentrations decreased; (iii) When compared to the Lorenz coefficient (Lc), the Cv was similarly effective at describing the grain-size variability, whereas it is simpler to calculate because it did not require the data to be pre-processed. The results of this study will facilitate identification of the uncertainty in modelling RDS caused by grain-size class variability. PMID:28788078

Role of urban surface roughness in road-deposited sediment build-up and wash-off

NASA Astrophysics Data System (ADS)

Zhao, Hongtao; Jiang, Qian; Xie, Wenxia; Li, Xuyong; Yin, Chengqing

2018-05-01

Urban road surface roughness is one of the most important factors in estimation of surface runoff loads caused by road-deposited sediment (RDS) wash-off and design of its control measures. However, because of a lack of experimental data to distinguish the role of surface roughness, the effects of surface roughness on RDS accumulation and release are not clear. In this study, paired asphalt and concrete road surfaces and rainfall simulation designs were used to distinguish the role of surface roughness in RDS build-up and wash-off. Our results showed that typical asphalt surfaces often have higher depression depths than typical concrete surfaces, indicating that asphalt surfaces are relatively rougher than concrete surface. Asphalt surfaces can retain a larger RDS amount, relative higher percentage of coarser particles, larger RDS wash-off loads, and lower wash-off percentage, than concrete surfaces. Surface roughness has different effects in RDS motilities with different particle sizes during rainfall runoff, and the settleable particles (44-149 μm) were notably influenced by it. Furthermore, the first flush phenomenon tended to be greater on relatively smooth surfaces than relatively rough surfaces. Overall, surface roughness plays an important role in influencing the complete process of RDS build-up and wash-off on different road characteristics.

Sexual Violence against Men Who Have Sex with Men and Transgender Women in Mongolia: A Mixed-Methods Study of Scope and Consequences.

PubMed

Peitzmeier, Sarah M; Yasin, Faiza; Stephenson, Rob; Wirtz, Andrea L; Delegchoimbol, Altanchimeg; Dorjgotov, Myagmardorj; Baral, Stefan

2015-01-01

The role of sexual violence in health and human rights-related outcomes, including HIV, is receiving increasing attention globally, yet the prevalence, patterns, and correlates of sexual violence have been little-studied among men who have sex with men (MSM) and transgender women in low and middle income countries. A mixed-methods study with quantitative and qualitative phases was conducted among MSM and transgender women in Ulaanbaatar, Mongolia. Methods included respondent-driven sampling (RDS) with structured socio-behavioral surveys (N = 313) as well as qualitative methods including 30 in-depth interviews and 2 focus group discussions. Forced sex in the last three years was reported by 14.7% of respondents (RDS-weighted estimate, 95%CI: 9.4-20.1; crude estimate 16.1%, 49/307) in the quantitative phase. A descriptive typology of common scenarios was constructed based on the specific incidents of sexual violence shared by respondents in the qualitative phase (37 incidents across 28 interviews and 2 focus groups). Eight major types of sexual violence were identified, most frequent of which were bias-motivated street violence and alcohol-involved party-related violence. Many vulnerabilities to and consequences of sexual violence described during the qualitative phase were also independently associated with forced sex, including alcohol use at least once per week (AOR = 3.39, 95% CI:1.69-6.81), and having received payment for sex (AOR = 2.77, 95% CI:1.14-6.75). Building on the promising strategies used in other settings to prevent and respond to sexual violence, similar strengthening of legal and social sector responses may provide much needed support to survivors and prevent future sexual violence.

Drug use among transgender people in Ontario, Canada: Disparities and associations with social exclusion.

PubMed

Scheim, Ayden I; Bauer, Greta R; Shokoohi, Mostafa

2017-09-01

We identified the prevalence and correlates of past-year illicit drug use among transgender people in Ontario, Canada, and disparities with the age-standardized non-transgender population. Data on transgender persons aged 16+ (n=406) were obtained from Trans PULSE, a respondent-driven sampling (RDS) survey (2009-2010). Overall and sex-specific estimates of past-year drug use (cocaine and amphetamines, based on data availability) in the reference population were obtained from Ontario residents aged 16+ (n=39, 980) in the Canadian Community Health Survey (2009-2010), and standardized to the overall and gender-specific transgender age distributions. For regression analyses with Trans PULSE data, past-year drug use included drug types associated with high risk of physical, psychological, and social harm to the user, and RDS-II weights were applied to frequencies and prevalence ratios (PR) derived from blockwise logistic regression models. An estimated 12.3% (95% CI: 7.7, 17.0) of transgender Ontarians had used at least one of the specified drugs in the past year, with no significant difference by gender identity. Transgender Ontarians were more likely to use both cocaine (standardized prevalence difference; SPD=6.8%; 95% CI=1.6, 10.9) and amphetamines (SPD=SPD=1.3%, 95% CI=0.2, 3.1) as compared to the age-standardized non-transgender population. History of transphobic assault, homelessness or underhousing, and sex work were associated with greater drug use among transgender persons. The prevalence of cocaine and amphetamine use among transgender people in Ontario, Canada was higher than in the age-standardized reference population. Social exclusion predicted within-group variation in drug use among transgender persons. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sexual Violence against Men Who Have Sex with Men and Transgender Women in Mongolia: A Mixed-Methods Study of Scope and Consequences

PubMed Central

Peitzmeier, Sarah M.; Yasin, Faiza; Stephenson, Rob; Wirtz, Andrea L.; Delegchoimbol, Altanchimeg; Dorjgotov, Myagmardorj; Baral, Stefan

2015-01-01

The role of sexual violence in health and human rights-related outcomes, including HIV, is receiving increasing attention globally, yet the prevalence, patterns, and correlates of sexual violence have been little-studied among men who have sex with men (MSM) and transgender women in low and middle income countries. A mixed-methods study with quantitative and qualitative phases was conducted among MSM and transgender women in Ulaanbaatar, Mongolia. Methods included respondent-driven sampling (RDS) with structured socio-behavioral surveys (N = 313) as well as qualitative methods including 30 in-depth interviews and 2 focus group discussions. Forced sex in the last three years was reported by 14.7% of respondents (RDS-weighted estimate, 95%CI: 9.4–20.1; crude estimate 16.1%, 49/307) in the quantitative phase. A descriptive typology of common scenarios was constructed based on the specific incidents of sexual violence shared by respondents in the qualitative phase (37 incidents across 28 interviews and 2 focus groups). Eight major types of sexual violence were identified, most frequent of which were bias-motivated street violence and alcohol-involved party-related violence. Many vulnerabilities to and consequences of sexual violence described during the qualitative phase were also independently associated with forced sex, including alcohol use at least once per week (AOR = 3.39, 95% CI:1.69–6.81), and having received payment for sex (AOR = 2.77, 95% CI:1.14–6.75). Building on the promising strategies used in other settings to prevent and respond to sexual violence, similar strengthening of legal and social sector responses may provide much needed support to survivors and prevent future sexual violence. PMID:26431311

Cross-border drug injection relationships among injection drug users in Tijuana, Mexico

PubMed Central

Wagner, Karla D.; Pollini, Robin A.; Patterson, Thomas L.; Lozada, Remedios; Ojeda, Victoria D.; Brouwer, Kimberly C.; Vera, Alicia; Volkmann, Tyson A.; Strathdee, Steffanie A.

2010-01-01

Background International borders are unique social and environmental contexts characterized by high levels of mobility. Among drug users, mobility increases risk for human immunodeficiency virus (HIV) in part through its effects on the social environment. However, the social dynamics of drug users living in border regions are understudied. Methods 1056 injection drug users (IDUs) residing in Tijuana, Mexico were recruited using respondent-driven sampling (RDS) from 2006 to 2007, and underwent surveys and testing for HIV, syphilis, and tuberculosis (TB). Using logistic regression on baseline data, we identified correlates of having ever injected drugs with someone from the US. Results Almost half (48%) reported ever injecting drugs with someone from the US. In RDS-adjusted logistic regression, factors independently associated with having ever injected with someone from the US included: having greater than middle school education (Adjusted Odds Ratio [AOR] 2.91; 95% Confidence Interval [C.I.] 1.52, 5.91), speaking English (AOR 3.24, 95% C.I. 1.96, 5.36), age (AOR 1.10 per year; 95% C.I. 1.07, 1.14), age at initiation of injection drug use (AOR 0.90 per year; 95% C.I. 0.86, 0.94), homelessness (AOR 2.61; 95% C.I. 1.27, 5.39), and having ever been incarcerated (AOR 11.82; 95% C.I., 5.22, 26.77). No associations with HIV, syphilis, TB, drug use, or injection risk behavior were detected. Conclusion Findings suggest that IDU networks in Mexico and the US may transcend international borders, with implications for cross-border transmission of infectious disease. Binational programs and policies need to consider the structure and geographic distribution of drug using networks. PMID:20889270

Prevalence and correlates of HIV among men who have sex with men in Tijuana, Mexico

PubMed Central

Pitpitan, Eileen V; Goodman-Meza, David; Burgos, Jose Luis; Abramovitz, Daniela; Chavarin, Claudia V; Torres, Karla; Strathdee, Steffanie A; Patterson, Thomas L

2015-01-01

Introduction Men who have sex with men (MSM) in developing countries such as Mexico have received relatively little research attention. In Tijuana, Mexico, a border city experiencing a dynamic HIV epidemic, data on MSM are over a decade old. Our aims were to estimate the prevalence and examine correlates of HIV infection among MSM in this city. Methods We conducted a cross-sectional study of 191 MSM recruited through respondent-driven sampling (RDS) in 2012. Biological males over the age of 18 who resided in Tijuana and reported sex with a male in the past year were included. Participants underwent interviewer-administered surveys and rapid tests for HIV and syphilis with confirmation. Results A total of 33 MSM tested positive for HIV, yielding an RDS-adjusted estimated 20% prevalence. Of those who tested positive, 89% were previously unaware of their HIV status. An estimated 36% (95% CI: 26.4–46.5) had been tested for HIV in the past year, and 30% (95% CI: 19.0–40.0) were estimated to have ever used methamphetamine. Independent correlates of being infected with HIV were methamphetamine use (odds ratio [OR]=2.24, p=0.045, 95% CI: 1.02, 4.92) and active syphilis infection (OR=4.33, p=0.01, 95% CI: 1.42, 13.19). Conclusions Our data indicate that MSM are a key sub-population in Tijuana at higher risk for HIV. Tijuana would also appear to have the highest proportion among upper-middle-income countries of HIV-positive MSM who are unknowingly infected. More HIV prevention research on MSM is urgently needed in Tijuana. PMID:25669423

Sample Federal Facility Land Use Control ROD Checklist and Suggested Language (LUC Checklist)

EPA Pesticide Factsheets

The LUC Checklist provides direction on describing and documenting land use controls (LUCs) in federal facility actrions under CERCLA in Records of Decision (RODs), remedial designs (RDs), and remedial action work plans (RAWPs).

Shooting Gallery Attendance among IDUs in Tijuana and Ciudad Juarez, Mexico: Correlates, Prevention Opportunities, and the Role of the Environment

PubMed Central

Philbin, Morgan; Pollini, Robin A.; Ramos, Rebecca; Lozada, Remedios; Brouwer, Kimberly C.; Ramos, Maria Elena; Firestone-Cruz, Michelle; Case, Patricia; Strathdee, Steffanie A.

2009-01-01

We identified factors associated with shooting gallery attendance among injection drug users (IDUs) in two Mexico–US border cities. IDUs in Tijuana (n = 222) and Ciudad Juarez (n = 205), Mexico, who were ≥18 years and injected illicit drugs in the last month were recruited using respondent-driven sampling (RDS). An interviewer-administered survey collected sociodemographic and behavioral data. Logistic regression was used to examine correlates of shooting gallery attendance in each of the two cities. Homelessness and being arrested for syringe possession—both structural level factors—were associated with shooting gallery use in both cities. In Ciudad Juarez, younger age and having overdosed were also associated with shooting gallery use. Our study highlights the need for structural interventions that mitigate homelessness among IDUs and facilitate changes in law enforcement practices associated with shooting gallery use. Harm reduction interventions based within shooting galleries should also be considered to prevent transmission of blood-borne pathogens among IDUs. PMID:18369723

Molecular Characterization of the Skate Peripherin/rds Gene: Relationship to Its Orthologues and Paralogues

PubMed Central

Li, Chibo; Ding, Xi-Qin; O’Brien, John; Al-Ubaidi, Muayyad R.

2010-01-01

PURPOSE A great deal of information about functionally significant domains of a protein may be obtained by comparison of primary sequences of gene homologues over a broad phylogenetic base. This study was designed to identify evolutionarily conserved domains of the photoreceptor disc membrane protein peripherin/rds by analysis of the homologue in a primitive vertebrate, the skate. METHODS A skate retinal cDNA library was screened using a mouse peripherin/rds clone. The 5′ and 3′ untranslated regions of the skate peripherin/rds (srds) cDNA were isolated by the rapid amplification of cDNA ends (RACE) approach. The gene structure was characterized by PCR amplification and sequencing of genomic fragments. Northern and Western blot analyses were used to identify srds transcript and protein, respectively. RESULTS A new homologue of peripherin/rds was identified from the skate retinal cDNA library. SRDS is a glycoprotein with a predicted molecular mass of 40.2 kDa. The srds gene consists of two exons and one small intron and transcribes into a single 6-kb message. Phylogenetic analysis places SRDS at the base of peripherin/rds family and near the division of that group and the branch leading to rds-like and rom-1 genes. SRDS protein is 54.5% identical with peripherin/rds across species. Identity is significantly higher (73%) in the intradiscal domains. Sequence comparison revealed the conservation of all residues that have been shown, on mutation, to associate with retinitis pigmentosa and showed conservation of most residues associated with macular dystrophies. Comparison with ROM-1 and other rds-like proteins revealed the presence of a highly conserved domain in the large intradiscal loop. CONCLUSIONS Srds represents the skate orthologue of mammalian peripherin/rds genes. Conservation of most of the residues associated with human retinal diseases indicates that these residues serve important functional roles. The high degree of conservation of a short stretch within the large intradiscal loop also suggests an important function for this domain. PMID:12766040

Molecular Genetic Testing in Reward Deficiency Syndrome (RDS): Facts and Fiction.

PubMed

Blum, Kenneth; Badgaiyan, Rajendra D; Agan, Gozde; Fratantonio, James; Simpatico, Thomas; Febo, Marcelo; Haberstick, Brett C; Smolen, Andrew; Gold, Mark S

The Brain Reward Cascade (BRC) is an interaction of neurotransmitters and their respective genes to control the amount of dopamine released within the brain. Any variations within this pathway, whether genetic or environmental (epigenetic), may result in addictive behaviors or RDS, which was coined to define addictive behaviors and their genetic components. To carry out this review we searched a number of important databases including: Filtered: Cochrane Systematic reviews; DARE; Pubmed Central Clinical Quaries; National Guideline Clearinghouse and unfiltered resources: PsychINFO; ACP PIER; PsychSage; Pubmed/Medline. The major search terms included: dopamine agonist therapy for Addiction; dopamine agonist therapy for Reward dependence; dopamine antagonistic therapy for addiction; dopamine antagonistic therapy for reward dependence and neurogenetics of RDS. While there are many studies claiming a genetic association with RDS behavior, not all are scientifically accurate. Albeit our bias, this Clinical Pearl discusses the facts and fictions behind molecular genetic testing in RDS and the significance behind the development of the Genetic Addiction Risk Score (GARS PREDX ™), the first test to accurately predict one's genetic risk for RDS.

Plasminogen activator inhibitor I 4G/5G polymorphism in neonatal respiratory distress syndrome.

PubMed

Armangil, Didem; Yurdakök, Murat; Okur, Hamza; Gürgey, Aytemiz

2011-08-01

Fibrin monomers inhibit surfactant function. 4G/5G insertion/deletion polymorphism plays an important role in the regulation of plasminogen activator inhibitor 1 (PAI-1) gene expression. To examine the genotype distribution of PAI-1 polymorphism in 60 infants with respiratory distress syndrome (RDS) and 53 controls, an allele-specific polymerase chain reaction (PCR) was used. The proportion of 4G/4G, 4G/5G, and 5G/5G genotypes did not differ statistically between the RDS and control groups (P > .05). Having PAI-1 4G/4G genotype polymorphism appears to increase the risk of RDS (odds ratio [OR] =1.5; 95% confidence interval [CI], 0.5-4.3), although it was not statistically significant. No relation was found between the PAI-1 4G/5G polymorphisms and RDS, but there was an increased risk associated with the 4G variant of the PAI-1 gene. We believe that our findings of increased 4G allele of the PAI-1 gene in infants with RDS would also help to clarify the pathogenesis of RDS.

Rotary drum separator system

NASA Technical Reports Server (NTRS)

Barone, Michael R. (Inventor); Murdoch, Karen (Inventor); Scull, Timothy D. (Inventor); Fort, James H. (Inventor)

2009-01-01

A rotary phase separator system generally includes a step-shaped rotary drum separator (RDS) and a motor assembly. The aspect ratio of the stepped drum minimizes power for both the accumulating and pumping functions. The accumulator section of the RDS has a relatively small diameter to minimize power losses within an axial length to define significant volume for accumulation. The pumping section of the RDS has a larger diameter to increase pumping head but has a shorter axial length to minimize power losses. The motor assembly drives the RDS at a low speed for separating and accumulating and a higher speed for pumping.

The Trends in Cardiovascular Diseases and Respiratory Diseases Mortality in Urban and Rural China, 1990-2015.

PubMed

Sun, Weiwei; Zhou, Yun; Zhang, Zhuang; Cao, Limin; Chen, Weihong

2017-11-15

With the rapid development of the economy over the past 20 years, the mortality rates from cardiovascular diseases (CVDs) and respiratory diseases (RDs) have changed in China. This study aimed to analyze the trends of mortality rates and years of life lost (YLLs) from CVDs and RDs in the rural and urban population from 1990 to 2015. Using data from Chinese yearbooks, joinpoint regression analysis was employed to estimate the annual percent change (APC) of mortality rates from CVDs and RDs. YLLs due to CVDs and RDs were calculated by a standard method, adopting recommended standard life expectancy at birth values of 80 years for men and 82.5 years for women. Age-standardized mortality rates and YLL rates were calculated by using the direct method based on the Chinese population from the sixth population census of 2010. Age-standardized mortality rates from CVDs for urban residents and from RDs for both urban and rural residents showed decreasing trends in China from 1990 to 2015. Age-standardized mortality rates from CVDs among rural residents remained constant during above period and outstripped those among urban residents gradually. The age-standardized YLL rates of CVDs for urban and rural residents decreased 35.2% and 8.3% respectively. Additionally, the age-standardized YLL rates of RDs for urban and rural residents decreased 64.2% and 79.0% respectively. The age-standardized mortality and YLL rates from CVDs and RDs gradually decreased in China from 1990 to 2015. We observed more substantial declines of the mortality rates from CVDs in urban areas and from RDs in rural areas.

Membrane curvature generation by a C-terminal amphipathic helix in peripherin-2/rds, a tetraspanin required for photoreceptor sensory cilium morphogenesis

PubMed Central

Khattree, Nidhi; Ritter, Linda M.; Goldberg, Andrew F. X.

2013-01-01

Summary Vertebrate vision requires photon absorption by photoreceptor outer segments (OSs), structurally elaborate membranous organelles derived from non-motile sensory cilia. The structure and function of OSs depends on a precise stacking of hundreds of membranous disks. Each disk is fully (as in rods) or partially (as in cones) bounded by a rim, at which the membrane is distorted into an energetically unfavorable high-curvature bend; however, the mechanism(s) underlying disk rim structure is (are) not established. Here, we demonstrate that the intrinsically disordered cytoplasmic C-terminus of the photoreceptor tetraspanin peripherin-2/rds (P/rds) can directly generate membrane curvature. A P/rds C-terminal domain and a peptide mimetic of an amphipathic helix contained within it each generated curvature in liposomes with a composition similar to that of OS disks and in liposomes generated from native OS lipids. Association of the C-terminal domain with liposomes required conical phospholipids, and was promoted by membrane curvature and anionic surface charge, results suggesting that the P/rds C-terminal amphipathic helix can partition into the cytosolic membrane leaflet to generate curvature by a hydrophobic insertion (wedging) mechanism. This activity was evidenced in full-length P/rds by its induction of small-diameter tubulovesicular membrane foci in cultured cells. In sum, the findings suggest that curvature generation by the P/rds C-terminus contributes to the distinctive structure of OS disk rims, and provide insight into how inherited defects in P/rds can disrupt organelle structure to cause retinal disease. They also raise the possibility that tethered amphipathic helices can function for shaping cellular membranes more generally. PMID:23886945

Nutrigenomics - perspectives from registered dietitians: a report from the Quebec-wide e-consultation on nutrigenomics among registered dietitians.

PubMed

Cormier, H; Tremblay, B L; Paradis, A-M; Garneau, V; Desroches, S; Robitaille, J; Vohl, M-C

2014-08-01

Not all healthcare professionals are familiar with nutrigenomics. However, they recognise that nutrigenomics has great potential for the development of preventive health approaches. The present study aimed to provide an overall picture of the current situation about nutrigenomics in the practice of registered dietitians (RDs) from the province of Quebec (Canada). Three hundred and seventy-three RDs members of the Ordre professionnel des diététistes du Québec completed an online survey that included 34 questions, most of which were closed-ended questions. Overall, 76.9% of RDs knew about nutrigenomics. Among RDs with <5 years of experience, 49.2% knew about genetic testing related to nutrition compared to 11.7% for RDs with over 25 years of experience. Currently, 75.9% of RDs working in clinical nutrition in the public sector consider that they do not have the basic knowledge to integrate nutrigenomics in their practice compared to 62.9% for RDs in private practice. When asked about main limitations of genetic testing related to nutrition, RDs considered that genetic testing does not consider the other determinants of health, that genetic testing and their results have poor accuracy, and that there is a lack of scientific evidence. Concerns remained about ethical and legal aspects and its difficult application as a result of poor understanding and/or interpretation by professionals and/or customers. The high costs of these tests were also noted as a limitation. Registered dietitians know and are interested in nutrigenomics, especially those with less experience, although they do not feel adequately qualified to integrate findings from nutrigenomics into their practice. © 2014 The British Dietetic Association Ltd.

Influence of low impact development construction on pollutant process of road-deposited sediments and associated heavy metals.

PubMed

Ma, Yukun; Gong, Manli; Zhao, Hongtao; Li, Xuyong

2018-02-01

Intense Low-Impact Development (LID) construction in China could lead to increasingly severe stormwater and receiving water pollution due to the lack of appropriate regulation for mitigating pollution from LID construction. Samples of road-deposited sediments (RDS) were collected from 50 study sites at seven LID construction stages and four road hierarchies to analyze the pollution process and determine the size of the region influenced by LID construction. Six heavy metals were analyzed, and the RDS index model was adopted to estimate the potential heavy metal load washed off by stormwater runoff. Analysis of variance revealed that the excavation and gravel filling of rain gardens and excavation of porous pavements were critical LID construction stages that contributed the largest masses of RDS per unit area to road surfaces. Although the concentration of heavy metals at LID construction sites was lower than at sites without LID construction, the load of heavy metals washed off from LID construction was much higher. In addition, the sizes of regions influenced by accumulated RDS from LID construction descended in the following order: arterial road (600-775m)>collector road (150-200m)>access road (100-150m)>laneway (20-30m). According to the characteristics of LID construction at the study sites, the potential total solid loads in stormwater throughout China were estimated to reach 36,694t by 2020 and 146,777t by 2030. According to the results of analysis, several recommendations are provided for designing LID construction regulations to mitigate stormwater pollution. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of Pre-exposure Prophylaxis (PrEP) in Young Men Who Have Sex with Men is Associated with Race, Sexual Risk Behavior and Peer Network Size.

PubMed

Kuhns, Lisa M; Hotton, Anna L; Schneider, John; Garofalo, Robert; Fujimoto, Kayo

2017-05-01

Pre-exposure prophylaxis (PrEP) is efficacious to prevent HIV infection, however, uptake among young men who have sex with men (YMSM) is relatively low. The purpose of this study was to describe PrEP use and related factors in a representative sample of YMSM in two cities, Chicago and Houston. YMSM, ages 16-29, were recruited via respondent-driven sampling (RDS) from 2014 to 2016. Correlates of PrEP uptake were assessed in weighted multivariable logistic regression models. A total of 12.2% of participants (of 394) reported ever taking PrEP; Black YMSM had the lowest rates of uptake (4.7%) and Whites the highest (29.5%). In a multivariable regression model, having an HIV positive sex partner, reporting recent group sex, peer network size, and city (Chicago) were significantly and positively associated with use of PrEP, while Black race was negatively associated with it. Given evidence of racial/ethnic disparities in PrEP uptake in this study, further research is needed to identify potential mechanisms of action and points of intervention.

Correlates of exchange sex among a population-based sample of low-income women who have heterosexual sex in Baltimore.

PubMed

Sherman, Susan G; Hast, Marisa; Park, Ju Nyeong; Decker, Michele R; Flynn, Colin; German, Danielle

2018-03-08

Sex exchange is associated with HIV and other morbidities yet has received little research, surveillance, and programmatic attention in the U.S. This study identified correlates of exchange sex and among low-income women in Baltimore, Maryland. Participants were recruited into the National HIV Behavioral Surveillance (NHBS) system in 2013 using respondent driven sampling (RDS) and completed a survey and HIV testing. The analytic sample (n = 253) consisted of women aged ≥18 years who had recent (past year) heterosexual sex. Multivariable logistic regression identified correlates of recent exchange sex. Independently associated with recent exchange sex were history of injection drug use (adjusted odds ratio (AOR) = 3.4, 95% CI: 1.1-10.3), recent prescription painkiller use (AOR = 3.7, 95% CI: 1.4-9.9), recent crack/cocaine use (AOR = 6.6, 95% CI: 2.1-20.9), recent arrest (AOR = 4.1, 95% CI: 1.2-14.8), and recent consistent condom use (AOR 1.1; 95% CI: 1.0-1.3). Women who exchanged sex exhibited heightened social and structural vulnerability and substance use. These data demonstrate the need for further research examining the context of exchange sex among low-income women and synergies between substance use and HIV risk.

Severity of club drug dependence and perceived need for treatment among a sample of adult club drug users in Shanghai, China

PubMed Central

Ding, Yingying; He, Na; Shoptaw, Steven; Gao, Meiyang; Detels, Roger

2013-01-01

Purpose Examine the severity of club drug dependence and perceived need for treatment, and further identify their determinants among a sample of club drug users in Shanghai, China. Methods 276 club drug users were recruited using respondent-driven sampling (RDS). Severity of dependence on club drugs was measured using the Severity of Dependence Scale (SDS). Results 69.9% reported dependence on club drugs (i.e., SDS≥4) and 36.6% reported severe dependence (i.e., SDS≥6). One eighth (12.7%) perceived need for drug treatment. Severe dependence on club drugs was more likely among those who reported recent use of ecstasy and those who had more depressive symptoms, but less likely among those reporting recent use of methamphetamine. Perceived need for treatment was more likely among those who lived with a spouse or boy/girlfriend, but less likely among those had prior drug treatment experience and more severe club drug dependence. Conclusions Our findings suggest that educational activities should be implemented to raise public awareness about the powerful addictive properties of club drugs, along with efforts to reduce stigma towards drug abuse and psychiatric disorders. Programs to motivate drug users to seek treatment and encourage treatment linkage are urgently needed. PMID:23715971

Normalizing rainfall/debris-flow thresholds along the U.S. Pacific coast for long-term variations in precipitation climate

USGS Publications Warehouse

Wilson, Raymond C.

1997-01-01

Broad-scale variations in long-term precipitation climate may influence rainfall/debris-flow threshold values along the U.S. Pacific coast, where both the mean annual precipitation (MAP) and the number of rainfall days (#RDs) are controlled by topography, distance from the coastline, and geographic latitude. Previous authors have proposed that rainfall thresholds are directly proportional to MAP, but this appears to hold only within limited areas (< 1?? latitude), where rainfall frequency (#RDs) is nearly constant. MAP-normalized thresholds underestimate the critical rainfall when applied to areas to the south, where the #RDs decrease, and overestimate threshold rainfall when applied to areas to the north, where the #RDs increase. For normalization between climates where both MAP and #RDs vary significantly, thresholds may best be described as multiples of the rainy-day normal, RDN = MAP/#RDs. Using data from several storms that triggered significant debris-flow activity in southern California, the San Francisco Bay region, and the Pacific Northwest, peak 24-hour rainfalls were plotted against RDN values, displaying a linear relationship with a lower bound at about 14 RDN. RDN ratios in this range may provide a threshold for broad-scale regional forecasting of debris-flow activity.

Late-onset cone photoreceptor degeneration induced by R172W mutation in Rds and partial rescue by gene supplementation.

PubMed

Conley, Shannon; Nour, May; Fliesler, Steven J; Naash, Muna I

2007-12-01

R172W is a common mutation in the human retinal degeneration slow (RDS) gene, associated with a late-onset dominant macular dystrophy. In this study, the authors characterized a mouse model that closely mimics the human phenotype and tested the feasibility of gene supplementation as a disease treatment strategy. Transgenic mouse lines carrying the R172W mutation were generated. The retinal phenotype associated with this mutation in a low-expresser line (L-R172W) was examined, both structurally (histology with correlative immunohistochemistry) and functionally (electroretinography). By examining animals over time and with various rds genetic backgrounds, the authors evaluated the dominance of the defect. To assess the efficacy of gene transfer therapy as a treatment for this defect, a previously characterized transgenic line expressing the normal mouse peripherin/Rds (NMP) was crossed with a higher-expresser Rds line harboring the R172W mutation (H-R172W). Functional, structural, and biochemical analyses were used to assess rescue of the retinal disease phenotype. In the wild-type (WT) background, L-R172W mice exhibited late-onset (12-month) dominant cone degeneration without any apparent effect on rods. The degeneration was slightly accelerated (9 months) in the rds(+/-) background. L-R172W retinas did not form outer segments in the absence of endogenous Rds. With use of the H-R172W line on an rds(+/-) background for proof-of-principle genetic supplementation studies, the NMP transgene product rescued rod and cone functional defects and supported outer segment integrity up to 3 months of age, but the rescue effect did not persist in older (11-month) animals. The R172W mutation leads to dominant cone degeneration in the mouse model, regardless of the expression level of the transgene. In contrast, effects of the mutation on rods are dose dependent, underscoring the usefulness of the L-R172W line as a faithful model of the human phenotype. This model may prove helpful in future studies on the mechanisms of cone degeneration and for elucidating the different roles of Rds in rods and cones. This study provides evidence that Rds genetic supplementation can be used to partially rescue visual function. Although this strategy is capable of rescuing haploinsufficiency, it does not rescue the long-term degeneration associated with a gain-of-function mutation.

An improved Huffman coding with encryption for Radio Data System (RDS) for smart transportation

NASA Astrophysics Data System (ADS)

Wu, C. H.; Tseng, Kuo-Kun; Ng, C. K.; Ho, G. T. S.; Zeng, Fu-Fu; Tse, Y. K.

2018-02-01

As the development of Radio Data System (RDS) technology and its applications are getting more and more attention and promotion, people concern their personal privacy and communication efficiency, and therefore compression and encryption technologies are being more important for transferring RDS data. Unlike most of the current approaches which contain two stages, compression and encryption, we proposed a new algorithm called Swapped Huffman Table (SHT) based on Huffman algorithm to realise compression and encryption in a single process. In this paper, a good performance for both compression and encryption is obtained and a possible application of RDS with the proposed algorithm in smart transportation is illustrated.

Can we Replace Arterial Blood Gas Analysis by Pulse Oximetry in Neonates with Respiratory Distress Syndrome, who are Treated According to INSURE Protocol?

PubMed Central

Niknafs, Pedram; Norouzi, Elahe; Bahman Bijari, Bahareh; Baneshi, Mohammad Reza

2015-01-01

Neonates with respiratory distress syndrome (RDS), who are treated according to INSURE protocol; require arterial blood gas (ABG) analysis to decide on appropriate management. We conducted this study to investigate the validity of pulse oximetry instead of frequent ABG analysis in the evaluation of these patients. From a total of 193 blood samples obtained from 30 neonates <1500 grams with RDS, 7.2% were found to have one or more of the followings: acidosis, hypercapnia, or hypoxemia. We found that pulse oximetry in the detection of hyperoxemia had a good validity to appropriately manage patients without blood gas analysis. However, the validity of pulse oximetry was not good enough to detect acidosis, hypercapnia, and hypoxemia. PMID:25999627

Genetic Addiction Risk Score (GARS): molecular neurogenetic evidence for predisposition to Reward Deficiency Syndrome (RDS).

PubMed

Blum, Kenneth; Oscar-Berman, Marlene; Demetrovics, Zsolt; Barh, Debmalya; Gold, Mark S

2014-12-01

We have published extensively on the neurogenetics of brain reward systems with reference to the genes related to dopaminergic function in particular. In 1996, we coined "Reward Deficiency Syndrome" (RDS), to portray behaviors found to have gene-based association with hypodopaminergic function. RDS as a useful concept has been embraced in many subsequent studies, to increase our understanding of Substance Use Disorder (SUD), addictions, and other obsessive, compulsive, and impulsive behaviors. Interestingly, albeit others, in one published study, we were able to describe lifetime RDS behaviors in a recovering addict (17 years sober) blindly by assessing resultant Genetic Addiction Risk Score (GARS™) data only. We hypothesize that genetic testing at an early age may be an effective preventive strategy to reduce or eliminate pathological substance and behavioral seeking activity. Here, we consider a select number of genes, their polymorphisms, and associated risks for RDS whereby, utilizing GWAS, there is evidence for convergence to reward candidate genes. The evidence presented serves as a plausible brain-print providing relevant genetic information that will reinforce targeted therapies, to improve recovery and prevent relapse on an individualized basis. The primary driver of RDS is a hypodopaminergic trait (genes) as well as epigenetic states (methylation and deacetylation on chromatin structure). We now have entered a new era in addiction medicine that embraces the neuroscience of addiction and RDS as a pathological condition in brain reward circuitry that calls for appropriate evidence-based therapy and early genetic diagnosis and that requires further intensive investigation.

Development and validation of a questionnaire to measure research involvement among registered dietitians.

PubMed

Whelan, Kevin; Copeland, Emma; Oladitan, Leah; Murrells, Trevor; Gandy, Joan

2013-04-01

Research involvement among registered dietitians (RDs) is important in advancing dietetics practice and ensuring high-quality and cost-effective health care. There are no standardized approaches to measuring levels of research involvement. The aim of the study was to develop a standardized measure of research involvement and test its validity and reliability among RDs. The Research Involvement Questionnaire (RIQ) was developed and underwent content validation, resulting in a content validity index of 0.92. A postal questionnaire survey of RDs was undertaken at two time points. RDs were purposively selected and, based on their number of publications and grants, were assigned by the authors to one of four levels of research involvement: evidence-based practice, collaborating on research, leading research, and leadership in research. Of 192 questionnaires mailed, 111 RDs (58%) returned the first RIQ, of whom 82 (74%) also returned the second RIQ. Total scores and scores for each level were higher for RDs with higher levels of research involvement (P<0.001). RDs assigned by the RIQ to higher levels of research involvement had higher qualifications; were qualified for longer; and had greater evidence of research output, including journal publications and grants (P<0.001). There was excellent internal consistency as measured using Cronbach's coefficient (α=.98). The level of research involvement assigned by the RIQ and by the purposive selection process agreed on 76% of occasions, indicating substantial agreement beyond chance (κ=0.67; P<0.001). The level of research involvement assigned by the RIQ at two time points agreed on 86% of occasions, indicating almost perfect agreement beyond chance (κ=0.81; P<0.001). A valid and reliable questionnaire has been developed to measure research involvement among RDs, providing a useful tool for evaluating and supporting members of the profession to become more involved in research. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Late-Onset Cone Photoreceptor Degeneration Induced by R172W Mutation in Rds and Partial Rescue by Gene Supplementation

PubMed Central

Conley, Shannon; Nour, May; Fliesler, Steven J.; Naash, Muna I.

2008-01-01

Purpose R172W is a common mutation in the human retinal degeneration slow (RDS) gene, associated with a late-onset dominant macular dystrophy. In this study, the authors characterized a mouse model that closely mimics the human phenotype and tested the feasibility of gene supplementation as a disease treatment strategy. Methods Transgenic mouse lines carrying the R172W mutation were generated. The retinal phenotype associated with this mutation in a low-expresser line (L-R172W) was examined, both structurally (histology with correlative immunohistochemistry) and functionally (electroretinography). By examining animals over time and with various rds genetic backgrounds, the authors evaluated the dominance of the defect. To assess the efficacy of gene transfer therapy as a treatment for this defect, a previously characterized transgenic line expressing the normal mouse peripherin/Rds (NMP) was crossed with a higher-expresser Rds line harboring the R172W mutation (H-R172W). Functional, structural, and biochemical analyses were used to assess rescue of the retinal disease phenotype. Results In the wild-type (WT) background, L-R172W mice exhibited late-onset (12-month) dominant cone degeneration without any apparent effect on rods. The degeneration was slightly accelerated (9 months) in the rds+/− background. L-R172W retinas did not form outer segments in the absence of endogenous Rds. With use of the H-R172W line on an rds+/− background for proof-of-principle genetic supplementation studies, the NMP transgene product rescued rod and cone functional defects and supported outer segment integrity up to 3 months of age, but the rescue effect did not persist in older (11-month) animals. Conclusions The R172W mutation leads to dominant cone degeneration in the mouse model, regardless of the expression level of the transgene. In contrast, effects of the mutation on rods are dose dependent, underscoring the usefulness of the L-R172W line as a faithful model of the human phenotype. This model may prove helpful in future studies on the mechanisms of cone degeneration and for elucidating the different roles of Rds in rods and cones. This study provides evidence that Rds genetic supplementation can be used to partially rescue visual function. Although this strategy is capable of rescuing haplo-insufficiency, it does not rescue the long-term degeneration associated with a gain-of-function mutation. PMID:18055786

Cross-sectional study of female sex workers in Soweto, South Africa: Factors associated with HIV infection.

PubMed

Coetzee, Jenny; Jewkes, Rachel; Gray, Glenda E

2017-01-01

In South Africa, the rate of HIV in the sex worker (SW) population is exceedingly high, but critical gaps exist in our understanding of SWs and the factors that make them vulnerable to HIV. This study aimed to estimate HIV prevalence among female sex workers (FSWs) in Soweto, South Africa, and to describe their sexual behavior and other factors associated with HIV infection. A cross-sectional, respondent-driven sampling (RDS) recruitment methodology was used to enroll 508 FSWs based in Soweto. Data were collected using a survey instrument, followed by two HIV rapid tests. Raw and RDS adjusted data were analyzed using a chi-squared test of association and multivariate logistic regression to show factors associated with HIV infection. HIV prevalence among FSWs was 53.6% (95% CI 47.5-59.9). FSWs were almost exclusively based in taverns (85.6%) and hostels (52.0%). Less than a quarter (24.4%) were under 25 years of age. Non-partner violence was reported by 55.5%, 59.6% of whom were HIV-infected. Advancing age, incomplete secondary schooling, migrancy and multiple clients increased the likelihood of HIV acquisition: >30 years of age was associated with a 4.9 times (95% CI 2.6-9.3) increased likelihood of HIV; incomplete secondary schooling almost tripled the likelihood (AOR 2.8, 95% CI 1.6-5.0); being born outside of the Gauteng province increased the likelihood of HIV 2.3 times (95% CI 1.3-4.0); and having more than five clients per day almost doubled the likelihood (AOR 1.9, 95% CI 1.1-3.2). Our findings highlight the extreme vulnerability of FSWs to HIV. Advancing age, limited education and multiple clients were risk factors associated with HIV, strongly driven by a combination of structural, biological and behavioral determinants. Evidence suggests that interventions need to be carefully tailored to the varying profiles of SW populations across South Africa. Soweto could be considered a microcosm of South Africa in terms of the epidemic of violence and HIV experienced by the SW population, which is influenced by factors often beyond an individual level of control. While describing a hitherto largely undocumented population of FSWs, our findings confirm the urgent need to scale up innovative HIV prevention and treatment programs for this population.

Health care-seeking patterns for female genital mutilation/cutting among young Somalis in Norway.

PubMed

Mbanya, Vivian N; Gele, Abdi A; Diaz, Esperanza; Kumar, Bernadette

2018-04-18

Female genital mutilation/cutting (FGM/C) is a great concern, considering all the potential health implications. Use of health care services related to FGM/C by women who have been subjected to FGM/C in Norway remains to be understood. This study aims to explore the health care-seeking patterns for FGM/C-related health care problems, among young Somalis in Norway. A cross-sectional study involving 325 young Somalis in Oslo was conducted in 2014 using respondent-driven sampling (RDS) technique. The RDS was initiated by a small number of recruited seeds, who were given coded coupons to recruit their peers to participate in the study. Eligible recruiters who participated in the study and redeemed their coupons created the first wave of respondents. The first wave further recruited their peers, the second wave. The cycle continued to attain the needed samples. Using interviews and structured questionnaires, data on socio-demographic, FGM/C status and FGM/C-related use of health care were obtained. Logistic regressions were used to compute the odds ratio (OR) and the confidence interval (CI) for the associations between demographic variables, to circumcision status and health care-seeking for FGM/C. This study will focus on the 159 female participants of the total 325. While 51.6% of the 159 women were subjected to FGM/C, only 20.3% of them used health care services for FGM/C-related problems. Women's FGM/C status was associated with age ≥ 12 years at migration, experience of stigma regarding FGM/C practice (p <  0.05), support of FGM/C practice, and place of birth of women (p <  0.05). Only one-fifth of the women with FGM/C sought care for FGM/C-related health problems. Our study does not provide the answers to why only a few of them sought care for FGM/C. However, as a large proportion of women did not seek care, it is important to investigate the reasons for this. For, we propose to conduct further research targeting girls and women who have undergone FGM/C to assess challenges in accessing health care services for proper intervention.

Synonymous ABCA3 Variants Do Not Increase Risk for Neonatal Respiratory Distress Syndrome

PubMed Central

Wambach, Jennifer A.; Wegner, Daniel J.; Heins, Hillary B.; Druley, Todd E.; Mitra, Robi D.; Hamvas, Aaron; Cole, F. Sessions

2014-01-01

Objective To determine whether synonymous variants in the adenosine triphosphate-binding cassette A3 transporter (ABCA3) gene increase the risk for neonatal respiratory distress syndrome (RDS) in term and late preterm infants of European and African descent. Study design Using next-generation pooled sequencing of race-stratified DNA samples from infants of European and African descent at $34 weeks gestation with and without RDS (n = 503), we scanned all exons of ABCA3, validated each synonymous variant with an independent genotyping platform, and evaluated race-stratified disease risk associated with common synonymous variants and collapsed frequencies of rare synonymous variants. Results The synonymous ABCA3 variant frequency spectrum differs between infants of European descent and those of African descent. Using in silico prediction programs and statistical strategies, we found no potentially disruptive synonymous ABCA3 variants or evidence of selection pressure. Individual common synonymous variants and collapsed frequencies of rare synonymous variants did not increase disease risk in term and late-preterm infants of European or African descent. Conclusion In contrast to rare, nonsynonymous ABCA3 mutations, synonymous ABCA3 variants do not increase the risk for neonatal RDS among term and late-preterm infants of European or African descent. PMID:24657120

Cone Structure in Retinal Degeneration Associated with Mutations in the peripherin/RDS Gene

PubMed Central

Talcott, Katherine E.; Ratnam, Kavitha; Sundquist, Sanna M.; Lucero, Anya S.; Day, Shelley; Zhang, Yuhua; Roorda, Austin

2011-01-01

Purpose. To study cone photoreceptor structure and function associated with mutations in the second intradiscal loop region of peripherin/RDS. Methods. High-resolution macular images were obtained with adaptive optics scanning laser ophthalmoscopy and spectral domain optical coherence tomography in four patients with peripherin/RDS mutations and 27 age-similar healthy subjects. Measures of retinal structure and fundus autofluorescence (AF) were correlated with visual function, including best-corrected visual acuity (BCVA), kinetic and static perimetry, fundus-guided microperimetry, full-field electroretinography (ERG), and multifocal ERG. The coding regions of the peripherin/RDS gene were sequenced in each patient. Results. Heterozygous mutations in peripherin/RDS were predicted to affect protein structure in the second intradiscal domain in each patient (Arg172Trp, Gly208Asp, Pro210Arg and Cys213Tyr). BCVA was at least 20/32 in the study eye of each patient. Diffuse cone-greater-than-rod dysfunction was present in patient 1, while rod-greater-than-cone dysfunction was present in patient 4; macular outer retinal dysfunction was present in all patients. Macular AF was heterogeneous, and the photoreceptor-retinal pigment epithelial (RPE) junction layer showed increased reflectivity at the fovea in all patients except patient 1, who showed cone-rod dystrophy. Cone packing was irregular, and cone spacing was significantly increased (z-scores >2) at most locations throughout the central 4° in each patient. Conclusions. peripherin/RDS mutations produced diffuse AF abnormalities, disruption of the photoreceptor/RPE junction, and increased cone spacing, consistent with cone loss in the macula. The abnormalities observed suggest that the integrity of the second intradiscal domain of peripherin/RDS is critical for normal macular cone structure. PMID:21071739

Surfactant protein B deficiency and gene mutations for neonatal respiratory distress syndrome in China Han ethnic population

PubMed Central

Yin, Xiaojuan; Meng, Fanping; wang, Yan; Xie, Lu; Kong, Xiangyong; Feng, Zhichun

2013-01-01

Objective: To determine whether the SP-B deficiency and gene mutations in exon 4 is associated with neonatal RDS in China Han ethnic population. Methods: The study population consisted of 40 neonates with RDS and 40 neonates with other diseases as control in China Han ethnic population. We Compared SP-B expression in lung tissue and bronchoalveolar lavage fluid with immunoblotting, and analyzed mutations in the SP-B gene with polymerase chain reaction (PCR) and gene sequencing. Results: In RDS group, low mature Surfactant protein B was found in both lung tissue and bronchoalveolar lavage fluid in 8 neonates. In control group, only 4 neonates with low mature Surfactant protein B in both lung tissue and bronchoalveolar lavage fluid. In RDS group, 20 neonates were found to have mutations in exon 4, 12 homozygous mutations with C/C genotype and 8 heterozygous mutations with C/T genotype in surfactant protein B gene+1580 polymorphism. There were 8 cases mutations in control group, 1 in C/C and 7 in C/T genotype. The frequency of homozygotes with C/C genotype was 0.3 and frequency of heterozygotes with C/T genotype was 0.02 in RDS group. In control group, frequency of homozygotes with C/C genotype was 0.025 and frequency of heterozygote with C/T genotype was 0.175. Conclusion: Low mature Surfactant protein B is associated with the pathogenesis of neonatal respiratory distress syndrome (RDS) in China Han ethnic population. Mutations in exon 4 of the surfactant protein B gene demonstrate an association between homozygous mutations with C/C genotype in SP-B gene and neonatal RDS. PMID:23330012

Grain size distribution of road-deposited sediment and its contribution to heavy metal pollution in urban runoff in Beijing, China.

PubMed

Zhao, Hongtao; Li, Xuyong; Wang, Xiaomei; Tian, Di

2010-11-15

Pollutant washoff from road-deposited sediment (RDS) is an increasing problem associated with the rapid urbanization of China that results in urban non-point source pollution. Here, we analyzed the RDS grain size distribution and its potential impact on heavy metal pollution in urban runoff from impervious surfaces of urban villages, colleges and residences, and main traffic roads in the Haidian District, Beijing, China. RDS with smaller grain size had a higher metal concentration. Specifically, particles with the smallest grain size (<44 μm) had the highest metal concentration in most areas (unit: mg/kg): Cd 0.28-1.31, Cr 57.9-154, Cu 68.1-142, Ni 25.8-78.0, Pb 73.1-222 and Zn 264-664. Particles with smaller grain size (<250 μm) contributed more than 80% of the total metal loads in RDS washoff, while suspended solids with a grain size <44 μm in runoff water accounted for greater than 70% of the metal mass in the total suspended solids (TSS). The heavy metal content in the TSS was 2.21-6.52% of that in the RDS. These findings will facilitate our understanding of the importance of RDS grain size distribution in heavy metal pollution caused by urban storm runoff. Copyright © 2010 Elsevier B.V. All rights reserved.

FROM THE HISTORY OF PHYSICS: The extraordinarily beautiful physical principle of thermonuclear charge design (on the occasion of the 50th anniversary of the test of RDS-37 — the first Soviet two-stage thermonuclear charge)

NASA Astrophysics Data System (ADS)

Goncharov, German A.

2005-11-01

On 22 November 1955, the Semipalatinsk test site saw the test of the first domestic two-stage thermonuclear RDS-37 charge. The charge operation was based on the principle of radiation implosion. The kernel of the principle consists in the radiation generated in a primary A-bomb explosion and confined by the radiation-opaque casing propagating throughout the interior casing volume and flowing around the secondary thermonuclear unit. The secondary unit experiences a strong compression under the irradiation, with a resulting nuclear and thermonuclear explosion. The RDS-37 explosion was the strongest of all those ever realized at the Semipalatinsk test site. It produced an indelible impression on the participants in the test. This document-based paper describes the genesis of the ideas underlying the RDS-37 design and reflects the critical moments in its development. The advent of RDS-37 was an outstanding accomplishment of the scientists and engineers of our country.

Properties of duck meat sausages supplemented with cereal flours.

PubMed

Yang, H S; Ali, M S; Jeong, J Y; Moon, S H; Hwang, Y H; Park, G B; Joo, S T

2009-07-01

Duck meat sausages were prepared using 10% beef fat (FDS) and 10% hydrated cereal flours including rice (RDS), wheat, corn, millet, and barley to replace fat. Control duck sausages (DS) were also prepared only with duck meat and duck meat plus 10% beef fat. Results showed that protein and fat contents significantly decreased and total expressible fluid reduced with the addition of cereal flours in duck sausage batters. The FDS had higher fat content and lower pH compared with others. Duck sausages with 10% supplemented wheat flour showed the lowest cooking loss among sausages and had similar redness and chroma values to FDS and DS. Texture analysis indicated that hardness of duck sausage significantly decreased when cereal flours and beef fat were added. In particular, RDS showed the lowest values for all texture measurements compared with others. Result of moisture absorption capacity suggested that the decrease in hardness in RDS was due to higher moisture retention for rice flour treatment. Sensory evaluation indicated that DS had significantly lower overall acceptability than RDS, due to its off-flavor, whereas RDS had higher overall acceptability than DS.

[Descriptive study of homophobia and vulnerability to HIV/AIDS of the transvestites in the Metropolitan Region of Recife, Brazil].

PubMed

de Sousa, Patricia Juliana; Ferreira, Luiz Oscar Cardoso; de Sá, Janilson Barros

2013-08-01

This study sought to ascertain the vulnerabilities to HIV/Aids of transvestites of the Metropolitan Region of Recife. The Respondent-Driven Sampling (RDS) method was selected for data collection. Among the 110 transvestites, high indices of homophobia were found in locations such as: security services, work facilities, family and religious environments, neighborhood, school, stores, leisure spaces, and healthcare services. Among the situations of violence experienced, the predominant cases involved verbal aggression (81.8%) and physical aggression (68.2%). The HIV test carried out at some stage in their lives was reported by 84.4% of the subjects. A high level of knowledge of the forms of HIV prevention and transmission was detected. The majority of the transvestites began their sexual activity before 15 years of age without condom use. It was seen that in the context of the HIV/Aids epidemic, the strategies for health promotion can only be effective if factors for enhancing the understanding of the vulnerability to HIV/Aids, such as homophobia, are considered.

HIV prevalence and factors associated with HIV infection among men who have sex with men in Cameroon

PubMed Central

Park, Ju Nyeong; Papworth, Erin; Kassegne, Sethson; Moukam, Laure; Billong, Serge Clotaire; Macauley, Issac; Yomb, Yves Roger; Nkoume, Nathalie; Mondoleba, Valentin; Eloundou, Jules; LeBreton, Matthew; Tamoufe, Ubald; Grosso, Ashley; Baral, Stefan D

2013-01-01

Introduction Despite men who have sex with men (MSM) being a key population for HIV programming globally, HIV epidemiologic data on MSM in Central Africa are sparse. We measured HIV and syphilis prevalence and the factors associated with HIV infection among MSM in Cameroon. Methods Two hundred and seventy-two and 239 MSM aged ≥18 from Douala and Yaoundé, respectively, were recruited using respondent-driven sampling (RDS) for this cross-sectional surveillance study in 2011. Participants completed a structured questionnaire and HIV and syphilis testing. Statistical analyses, including RDS-weighted proportions, bootstrapped confidence intervals and logistic regressions, were used. Results Crude and RDS-weighted HIV prevalence were 28.6% (73/255) and 25.5% (95% CI 19.1–31.9) in Douala, and 47.3% (98/207) and 44.4% (95% CI 35.7–53.2) in Yaoundé. Active syphilis prevalence in total was 0.4% (2/511). Overall, median age was 24 years, 62% (317/511) of MSM identified as bisexual and 28.6% (144/511) identified as gay. Inconsistent condom use with regular male partners (64.1%; 273/426) and casual male and female partners (48.5%; 195/402) was common, as was the inconsistent use of condom-compatible lubricants (CCLs) (26.3%; 124/472). In Douala, preferring a receptive sexual role was associated with prevalent HIV infection [adjusted odds ratio (aOR) 2.33, 95% CI 1.02–5.32]. Compared to MSM without HIV infection, MSM living with HIV were more likely to have ever accessed a health service targeting MSM in Douala (aOR 4.88, 95% CI 1.63–14.63). In Yaoundé, MSM living with HIV were more likely to use CCLs (aOR 2.44, 95% CI 1.19–4.97). Conclusions High HIV prevalence were observed and condoms and CCLs were used inconsistently indicating that MSM are a priority population for HIV prevention, treatment and care services in Douala and Yaoundé. Building the capacity of MSM community organizations and improving the delivery and scale-up of multimodal interventions for MSM that are sensitive to concerns about confidentiality and the complex individual, social, community-level and policy challenges are needed to successfully engage young MSM in the continuum of HIV care. In addition to scaling up condom and CCL access, evaluating the feasibility of novel biomedical interventions, including antiretroviral pre-exposure prophylaxis and early antiretroviral therapy for MSM living with HIV in Cameroon, is also warranted. PMID:24321114

Simulation, design, and testing of a high power collimator for the RDS-112 cyclotron.

PubMed

Peeples, Johanna L; Stokely, Matthew H; Poorman, Michael C; Bida, Gerald T; Wieland, Bruce W

2015-03-01

A high power [F-18] fluoride target package for the RDS-112 cyclotron has been designed, tested, and commercially deployed. The upgrade includes the CF-1000 target, a 1.3kW water target with an established commercial history on RDS-111/Eclipse cyclotrons, and a redesigned collimator with improved heat rejection capabilities. Conjugate heat transfer analyses were employed to both evaluate the existing collimator capabilities and design a suitable high current replacement. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sexting among young adults

PubMed Central

Gordon-Messer, Deborah; Bauermeister, Jose Arturo; Grodzinski, Alison; Zimmerman, Marc

2012-01-01

Purpose Sexting has stirred debate over its legality and safety, but few researchers have documented the relationship between sexting and health. We describe the sexting behavior of young adults in the United States, and examine its association with sexual behavior and psychological well-being. Methods Using an adapted web version of Respondent-Driven Sampling (webRDS) we recruited a sample of U.S. young adults (ages 18 to 24; N=3447). We examined participant sexting behavior using 4 categories of sexting: 1) Non-Sexters, 2) Receivers, 3) Senders, and 4) Two-way Sexters. We then assessed the relationships between sexting categories and sociodemographic characteristics, sexual behavior and psychological well-being. Results Over half (57%) of respondents were Non-Sexters, 28.2% of the sample were Two-way Sexters, 12.6% were Receivers, and 2% were Senders. Males were more likely to be Receivers than females. Sexually active respondents were more likely to be Two-way Sexters than non-sexually active respondents. Among participants who were sexually active in the past 30 days, we found no differences across sexting groups in number of sexual partners, or number of unprotected sex partners in the past 30 days. We also found no relationship between sexting and psychological well-being. Conclusions Our results suggest that sexting is not related to sexual risk behavior or psychological well-being. We discuss the findings of this study and propose directions for further research on sexting. PMID:23299018

In vitro starch digestibility, pasting and textural properties of mung bean: effect of different processing methods.

PubMed

Kaur, Maninder; Sandhu, Kawaljit Singh; Ahlawat, RavinderPal; Sharma, Somesh

2015-03-01

Mung bean was subjected to different processing conditions (soaking, germination, cooking and autoclaving) and their textural, pasting and in vitro starch digestibility characteristics were studied. A significant reduction in textural properties (hardness, cohesiveness, gumminess and chewiness) after cooking and autoclaving treatment of mung bean was observed. Flours made from differently processed mung bean showed significant differences (P < 0.05) in their pastin g characteristics. Peak and final viscosity were the highest for flour from germinated mung bean whereas those made from autoclaved mung bean showed the lowest value. in vitro starch digestibility of mung bean flours was assessed enzymatically using modified Englyst method and the parameters studied were readily digestible starch (RDS), slowly digestible starch (SDS), resistant starch (RS) and total starch (TS) content. Various processing treatments increased the RDS contents of mung bean, while the SDS content was found to be the highest for soaked and the lowest for the autoclaved sample. Germinated sample showed higher amount of digestible starch (RDS + SDS) as compared to raw and soaked samples. Flours from raw and soaked samples showed significantly low starch hydrolysis rate at all the temperatures with total hydrolysis of 29.9 and 31.2 %, respectively at 180 min whereas cooked and autoclaved samples showed high hydrolysis rates with 50.2 and 53.8 % of these hydrolyzing within 30 min of hydrolysis.

Association between Interleukin-10-1082 G/A and Tumor Necrosis Factor-α 308 G/A Gene Polymorphisms and Respiratory Distress Syndrome in Iranian Preterm Infants.

PubMed

Khoshdel, Abolfazl; Kheiri, Soleiman; Omidvari, Peyman; Moradi, Fahimeh; Hamidi, Majid; Teimori, Hossein

2017-01-01

Cytokine polymorphisms may contribute to the prevalence of respiratory distress syndrome. The present study was done to investigate the frequency of interleukin- (IL-) 10 and tumor necrosis factor- (TNF-) α gene polymorphisms and their association with the risk of RDS in preterm infants. One-hundred and nineteen patients with RDS and 119 healthy preterm infants were enrolled. PCR restriction fragment length polymorphism was used to determine the frequency of IL-10 and TNF- α genotypes at -1082 A and -308 A, respectively. One-hundred and nineteen out of 238 infants had RDS (50%). The age of the mothers and gestational age ranged 17-45 (mean: 28.6 ± 5.3) years and 24-34 (mean: 34.3 ± 2.38) weeks, respectively. Totally, 23 deaths were recorded in the RDS group. Incidence of TNF- α -308 A/A and TNF- α -308 G/A was 84% and 16%, respectively. TNF-a-308 G/G was not found in both groups. Prevalence of IL-10-1082 G/G and IL-10-1082 G/A variants was 65.5% and 34.5%, respectively. IL-10-1082 A/A was not found in both groups. The incidence of the allele G in the IL-10-1082 polymorphism was lower in RDS group ( P < 0.05). We found that the risk of RDS was correlated to sex, gestational age, and IL-10-1082.

Association between Interleukin-10-1082 G/A and Tumor Necrosis Factor-α 308 G/A Gene Polymorphisms and Respiratory Distress Syndrome in Iranian Preterm Infants

PubMed Central

Omidvari, Peyman; Moradi, Fahimeh; Hamidi, Majid; Teimori, Hossein

2017-01-01

Cytokine polymorphisms may contribute to the prevalence of respiratory distress syndrome. The present study was done to investigate the frequency of interleukin- (IL-) 10 and tumor necrosis factor- (TNF-) α gene polymorphisms and their association with the risk of RDS in preterm infants. One-hundred and nineteen patients with RDS and 119 healthy preterm infants were enrolled. PCR restriction fragment length polymorphism was used to determine the frequency of IL-10 and TNF-α genotypes at -1082 A and -308 A, respectively. One-hundred and nineteen out of 238 infants had RDS (50%). The age of the mothers and gestational age ranged 17–45 (mean: 28.6 ± 5.3) years and 24–34 (mean: 34.3 ± 2.38) weeks, respectively. Totally, 23 deaths were recorded in the RDS group. Incidence of TNF-α-308 A/A and TNF-α-308 G/A was 84% and 16%, respectively. TNF-a-308 G/G was not found in both groups. Prevalence of IL-10-1082 G/G and IL-10-1082 G/A variants was 65.5% and 34.5%, respectively. IL-10-1082 A/A was not found in both groups. The incidence of the allele G in the IL-10-1082 polymorphism was lower in RDS group (P < 0.05). We found that the risk of RDS was correlated to sex, gestational age, and IL-10-1082. PMID:28298812

Syringe possession arrests are associated with receptive syringe sharing in two Mexico-US border cities

PubMed Central

Pollini, Robin A.; Brouwer, Kimberly C.; Lozada, Remedios M.; Ramos, Rebeca; Cruz, Michelle F.; Magis-Rodriguez, Carlos; Case, Patricia; Burris, Scott; Pu, Minya; Frost, Simon D. W.; Palinkas, Lawrence A.; Miller, Cari; Strathdee, Steffanie A.

2008-01-01

Aims To identify factors associated with receptive syringe sharing among injection drug users (IDUs) and elucidate the association between syringe possession arrests and syringe sharing. Design Cross-sectional study. Setting Mexican border cities of Tijuana, Baja California and Ciudad Juarez, Chihuahua. Participants IDUs in Tijuana (n = 222) and Ciudad Juarez (n = 206) were recruited using respondent-driven sampling (RDS). IDUs were ≥18 years and had injected illicit drugs in the past month. Measurements An interviewer-administered survey was used to collect quantitative data on socio-demographic, behavioral and contextual characteristics, including self-reported syringe sharing and arrests for syringe possession. Associations with receptive syringe sharing were investigated using logistic regression with RDS adjustment. Findings Overall, 48% of participants reported ever being arrested for carrying an unused/sterile syringe, even though syringe purchase and possession is legal in Mexico. Arrest for possessing unused/sterile syringes was associated independently with receptive syringe sharing [adjusted odds ratio (AOR) = 2.05; 95% confidence interval (CI): 1.26, 3.35], as was injecting in a shooting gallery (AOR = 3.60; 95% CI: 2.21, 5.87), injecting in the street (AOR = 2.05; 95% CI: 1.18, 3.54) and injecting methamphetamine (AOR = 2.77; 95% CI: 1.41, 5.47) or cocaine (AOR = 1.96; 95% CI: 1.15, 3.36). More than half of participants (57%) had been arrested for possessing a used syringe; in a second model, arrest for used syringe possession was also associated independently with receptive sharing (AOR = 2.87; 95% CI: 1.76, 4.69). Conclusions We documented high levels of syringe-related arrests in two Mexican–US border cities and an independent association between these arrests and risky injection practices. Public health collaborations with law enforcement to modify the risk environment in which drug use occurs are essential to facilitate safer injection practices. PMID:18028520

Physical and Sexual Violence Affecting Female Sex Workers in Abidjan, Côte d'Ivoire: Prevalence, and the Relationship with the Work Environment, HIV, and Access to Health Services.

PubMed

Lyons, Carrie E; Grosso, Ashley; Drame, Fatou M; Ketende, Sosthenes; Diouf, Daouda; Ba, Ibrahima; Shannon, Kate; Ezouatchi, Rebecca; Bamba, Amara; Kouame, Abo; Baral, Stefan

2017-05-01

Violence is a human rights violation, and an important measure in understanding HIV among female sex workers (FSW). However, limited data exist regarding correlates of violence among FSW in Côte d'Ivoire. Characterizing prevalence and determinants of violence and the relationship with structural risks for HIV can inform development and implementation of comprehensive HIV prevention and treatment programs. FSW > 18 years were recruited through respondent driven sampling (RDS) in Abidjan, Côte d'Ivoire. In total, 466 participants completed a socio-behavioral questionnaire and HIV testing. Prevalence estimates of violence were calculated using crude and RDS-adjusted estimates. Relationships between structural risk factors and violence were analyzed using χ tests and multivariable logistic regression. The prevalence of physical violence was 53.6% (250/466), and sexual violence was 43.2% (201/465) among FSW in this study. Police refusal of protection was associated with physical (adjusted Odds Ratio [aOR]: 2.8; 95% confidence interval [CI]: 1.7 to 4.4) and sexual violence (aOR: 3.0; 95% CI: 1.9 to 4.8). Blackmail was associated with physical (aOR: 2.5; 95% CI: 1.5 to 4.2) and sexual violence (aOR: 2.4; 95% CI: 1.5 to 4.0). Physical violence was associated with fear (aOR: 2.2; 95% CI: 1.3 to 3.1) and avoidance of seeking health services (aOR: 2.3; 95% CI: 1.5 to 3.8). Violence is prevalent among FSW in Abidjan and associated with features of the work environment and access to care. These relationships highlight layers of rights violations affecting FSW, underscoring the need for structural interventions and policy reforms to improve work environments, and to address police harassment, stigma, and rights violations to reduce violence and improve access to HIV interventions.

Disassortative mixing patterns of drug-using and sex networks on HIV risk behaviour among young drug users in Yunnan, China.

PubMed

Li, J; Luo, J; Li, J; Liu, H

2015-09-01

The dominant mode of HIV transmission in China has changed from injection drug use to sexual contact. The objectives of this study were to describe the disassortative and assortative mixing patterns of drug-using and sex networks among young drug users in China. Cross-sectional study. Respondent-driven sampling (RDS) was used to recruit young drug users in an egocentric network study in Yunnan, China. Egos were categorized as having disassortative mixing network patterns if they reported both sex and drug-using networks. Egos who only had a sex network (no drug-using network), or only a drug-using network (no sex network) were categorized as having assortative mixing network patterns. Multiple logistic regression was performed to analyze the relationships between disassortative patterns with risky sexual behaviour and drug-using practices. A total of 426 participants were recruited into the study. Two hundred forty-two egos reported disassortative mixing patterns and 139 egos had assortative patterns. The RDS-adjusted proportion of having a disassortative pattern was 53.2%. Participants with disassortative patterns were more likely to engage in HIV risk behaviour compared to those with assortative patterns. Specifically, drug users with disassortative patterns reported more multiple sex partners (31.4% vs 19.6%), concurrent partnerships (52.1% vs 39.0%), non-regular sex partners (12.0% vs 4.3%), and sex partners who were IDUs (24.9% vs 12.5%). Consistent condom use with regular or non-regular partners was low (between 18.9% and 47.2%) regardless of the mixing pattern. However, parenteral risk for HIV transmission was relatively low in both groups. The transition of the HIV epidemic in China from injection drug use to sexual contact may be attributed to disassortative mixing in drug-use and sexual networks. HIV programs should consider disassortative mixing patterns when designing new behavioural interventions. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Where Do Female Sex Workers Seek HIV and Reproductive Health Care and What Motivates These Choices? A Survey in 4 Cities in India, Kenya, Mozambique and South Africa.

PubMed

Lafort, Yves; Greener, Ross; Roy, Anuradha; Greener, Letitia; Ombidi, Wilkister; Lessitala, Faustino; Haghparast-Bidgoli, Hassan; Beksinska, Mags; Gichangi, Peter; Reza-Paul, Sushena; Smit, Jenni A; Chersich, Matthew; Delva, Wim

2016-01-01

A baseline cross-sectional survey among female sex workers (FSWs) was conducted in four cities within the context of an implementation research project aiming to improve FSWs' access to HIV, and sexual and reproductive health (SRH) services. The survey measured where FSWs seek HIV/SRH care and what motivates their choice. Using respondent-driven sampling (RDS), FWSs were recruited in Durban, South Africa (n = 400), Tete, Mozambique (n = 308), Mombasa, Kenya (n = 400) and Mysore, India (n = 458) and interviewed. RDS-adjusted proportions were estimated by non-parametric bootstrapping, and compared across cities using post-hoc pairwise comparison tests. Across cities, FSWs most commonly sought care for the majority of HIV/SRH services at public health facilities, most especially in Durban (ranging from 65% for condoms to 97% for HIV care). Services specifically targeting FSWs only had a high coverage in Mysore for STI care (89%) and HIV testing (79%). Private-for-profit clinics were important providers in Mombasa (ranging from 17% for STI care and HIV testing to 43% for HIV care), but not in the other cities. The most important reason for the choice of care provider in Durban and Mombasa was proximity, in Tete 'where they always go', and in Mysore cost of care. Where available, clinics specifically targeting FSWs were more often chosen because of shorter waiting times, perceived higher quality of care, more privacy and friendlier personnel. The place where care is sought for HIV/SRH services differs substantially between cities. Targeted services have limited coverage in the African cities compared to Mysore. Convenience appears more important for choosing the place of care than aspects of quality of care. The best model to improve access, linking targeted interventions with general health services, will need to be tailored to the specific context of each city.

Intra-amniotic instillation of surfactants for the prevention of neonatal respiratory distress syndrome following preterm delivery.

PubMed

Agarwal, Nutan; Bathwal, Shikha; Kriplani, Alka; Deorari, Ashok; Bhatla, Neerja

2016-11-01

To assess the efficacy of intra-amniotic administration of surfactants in reducing the incidence and severity of respiratory distress syndrome (RDS), and the need for postnatal endotracheal surfactant during preterm delivery. A prospective pilot study enrolled pregnant women at 28-34 weeks of pregnancy between July 1, 2013 and December 31, 2014 who were randomly assigned in a 1:1 ratio to a control group or to receive intra-amniotic surfactant (3mL) administered under ultrasonography guidance within 2-8 hours of expected delivery. The primary outcomes, the incidence and severity of RDS, and the need for postnatal surfactants, were analyzed on an intention-to-treat basis. The study enrolled 20 patients to each group. The incidence of RDS did not differ between the two groups (P=0.110). Severe RDS was more common in the control group (P=0.018) and postnatal surfactants were required more frequently in the control group (P=0.02). Intra-amniotic administration of surfactants reduced RDS severity and the need for postpartum endotracheal surfactants. Clinical Trials Registry India: CTRI/2015/12/006399. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Using Network Sampling and Recruitment Data to Understand Social Structures Related to Community Health in a Population of People Who Inject Drugs in Rural Puerto Rico.

PubMed

Coronado-García, Mayra; Thrash, Courtney R; Welch-Lazoritz, Melissa; Gauthier, Robin; Reyes, Juan Carlos; Khan, Bilal; Dombrowski, Kirk

2017-06-01

This research examined the social network and recruitment patterns of a sample of people who inject drugs (PWIDs) in rural Puerto Rico, in an attempt to uncover systematic clustering and between-group social boundaries that potentially influence disease spread. Respondent driven sampling was utilized to obtain a sample of PWID in rural Puerto Rico. Through eight initial "seeds", 317 injection drug users were recruited. Using recruitment patterns of this sample, estimates of homophily and affiliation were calculated using RDSAT. Analyses showed clustering within the social network of PWID in rural Puerto Rico. In particular, females showed a very high tendency to recruit male PWID, which suggests low social cohesion among female PWID. Results for (believed) HCV status at the time of interview indicate that HCV+ individuals were less likely to interact with HCV- individuals or those who were unaware of their status, and may be acting as "gatekeepers" to prevent disease spread. Individuals who participated in a substance use program were more likely to affiliate with one another. The use of speedballs was related to clustering within the network, in which individuals who injected this mixture were more likely to affiliate with other speedball users. Social clustering based on several characteristics and behaviors were found within the IDU population in rural Puerto Rico. RDS was effective in not only garnering a sample of PWID in rural Puerto Rico, but also in uncovering social clustering that can potentially influence disease spread among this population.

A heterozygous putative null mutation in ROM1 without a mutation in peripherin/RDS in a family with retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakuma, Hitoshi; Inana, G.; Murakami, Akira

1995-05-20

ROM1 is a 351-amino-acid, 37-kDa outer segment membrane protein of rod photoreceptors. ROM1 is related to peripherin/RDS, another outer segment membrane protein found in both rods and cones. The precise function of ROM1 or peripherin/RDS is not known, but they have been suggested to play important roles in the function and/or structure of the rod photoreceptor outer segment disks. A recent report implicated ROM1 in disease by suggesting that RP can be caused by a heterozygous null mutation in ROM1 but only in combination with another heterozygous mutation in peripherin/RDS. Screening of the ROM1 gene using polymerase chain reaction amplification,more » denaturing gradient gel electrophoresis, and direct DNA sequencing identified the same heterozygous putative null mutation in a family with RP.« less

Sorting photons of different rotational Doppler shifts (RDS) by orbital angular momentum of single-photon with spin-orbit-RDS entanglement.

PubMed

Chen, Lixiang; She, Weilong

2008-09-15

We demonstrate that single photons from a rotating q-plate exhibit an entanglement in three degrees of freedom of spin, orbital angular momentum, and the rotational Doppler shift (RDS) due to the nonconservation of total spin and orbital angular momenta. We find that the rotational Doppler shift deltaomega = Omega((delta)s + deltal) , where s, l and Omega are quantum numbers of spin, orbital angular momentum, and rotating velocity of the q-plate, respectively. Of interest is that the rotational Doppler shift directly reflects the rotational symmetry of q-plates and can be also expressed as deltaomega = (Omega)n , where n = 2(q-1) denotes the fold number of rotational symmetry. Besides, based on this single-photon spin-orbit-RDS entanglement, we propose an experimental scheme to sort photons of different frequency shifts according to individual orbital angular momentum.

Patient-Reported Outcome and Observer-Reported Outcome Assessment in Rare Disease Clinical Trials: An ISPOR COA Emerging Good Practices Task Force Report.

PubMed

Benjamin, Katy; Vernon, Margaret K; Patrick, Donald L; Perfetto, Eleanor; Nestler-Parr, Sandra; Burke, Laurie

Rare diseases (RDs) affect a small number of people within a population. About 5000 to 8000 distinct RDs have been identified, with an estimated 6% to 8% of people worldwide suffering from an RD. Approximately 75% of RDs affect children. Frequently, these conditions are heterogeneous; many are progressive. Regulatory incentives have increased orphan drug designations and approvals. To develop emerging good practices for RD outcomes research addressing the challenges inherent in identifying, selecting, developing, adapting, and implementing patient-reported outcome (PRO) and observer-reported outcome (ObsRO) assessments for use in RD clinical trials. This report outlines the challenges and potential solutions in determining clinical outcomes for RD trials. It follows the US Food and Drug Administration Roadmap to Patient-Focused Outcome Measurement in Clinical Trials. The Roadmap consists of three columns: 1) Understanding the Disease or Condition, 2) Conceptualizing Treatment Benefit, and 3) Selecting/Developing the Outcome Measure. Challenges in column 1 include factors such as incomplete natural history data and heterogeneity of disease presentation and patient experience. Solutions include using several information sources, for example, clinical experts and patient advocacy groups, to construct the condition's natural history and understand treatment patterns. Challenges in column 2 include understanding and measuring treatment benefit from the patient's perspective, especially given challenges in defining the context of use such as variations in age or disease severity/progression. Solutions include focusing on common symptoms across patient subgroups, identifying short-term outcomes, and using multiple types of COA instruments to measure the same constructs. Challenges in column 3 center around the small patient population and heterogeneity of the condition or study sample. Few disease-specific instruments for RDs exist. Strategies include adapting existing instruments developed for a similar condition or that contain symptoms of importance to the RD patient population, or using a generic instrument validated for the context of use. This report provides state-of-the-art solutions to patient-reported outcome (PRO) and observer-reported outcome (ObsRO) assessments challenges in clinical trials of patients with RDs. These recommended solutions are both pragmatic and creative and posed with clear recognition of the global regulatory context used in RD clinical development programs. Copyright © 2017. Published by Elsevier Inc.

Removal of road deposited sediments by sweeping and its contribution to highway runoff quality in Korea.

PubMed

Kim, D G; Jeong, K; Ko, S O

2014-01-01

Highway runoff is known to be an important non-point source (NPS), increasing the load of pollutants in receiving water. For reducing NPS pollutants in runoff, removal of road deposited sediment (RDS) by sweeping is considered effective. However, the contribution of sweeping to the improvement of runoff quality has not been clearly and quantitatively demonstrated so far. In this study, a field test was carried out on a section of operating highway in Korea to investigate the effectiveness of sweeping on improving the quality of highway runoff. Results showed that the average reduction in the load of RDS by sweeping was 61.10% with a standard deviation of 1.74%. RDS removal efficiency decreased when the sweeping speed increased from 4-8 to 20 km h(-1), the load decreased from 12.5 to 1.25 g m(-2) and particle size decreased from sand to silt/clay size ranges. Runoff was induced by applying a 15 mm h(-1) artificial rainfall to both swept and non-swept sections. Analysis of runoff quality showed that the event mean concentrations of total suspended solid, biological oxygen demand, chemical oxygen demand, nutrients and most of the heavy metals were reduced by 31-87% after sweeping. In addition, field tests for RDS build-up indicated a sweeping frequency of once every four or five days to prevent re-suspension of RDS. The results of this study suggest that sweeping can be the best management practice for effectively reducing RDS on highways and improving the quality of highway runoff.

Lung ultrasonography of pulmonary complications in preterm infants with respiratory distress syndrome.

PubMed

Lovrenski, Jovan

2012-03-01

To evaluate the diagnostic possibilities of lung ultrasonography (LUS) in detecting pulmonary complications in preterm infants with respiratory distress syndrome (RDS). A prospective study included 120 preterm infants with clinical and radiographic signs of RDS. LUS was performed using both a transthoracic and a transabdominal approach within the first 24 h of life, and, after that, follow-up LUS examinations were performed. In 47 detected pulmonary complications of RDS (hemorrhage, pneumothorax, pneumonia, atelectasis, bronchopulmonary dysplasia), comparisons between LUS and chest X-ray (CXR) were made. Also, 90 subpleural consolidations registered during LUS examinations were analysed. Statistical analysis included MANOVA and discriminant analysis, t-test, confidence interval, and positive predictive value. In 45 of 47 instances the same diagnosis of complication was detected with LUS as with CXR, indicating a high reliability of the method in premature infants with RDS. The only two false negative findings concerned partial pneumothorax. The positive predictive value of LUS was 100%. A statistically significant difference of LUS findings between the anterior and posterior lung areas was observed in both right and left hemithoraces. LUS enables the detection of pulmonary complications in preterm infants with RDS and has the potential to reduce the number of CXRs. The specific guidelines for its use should be provided in a more extensive study.

Pre- and postprocessing for reservoir simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, W.L.; Ingalls, L.J.; Prasad, S.J.

1991-05-01

This paper describes the functionality and underlying programing paradigms of Shell's simulator-related reservoir-engineering graphics system. THis system includes the simulation postprocessing programs Reservoir Display System (RDS) and Fast Reservoir Engineering Displays (FRED), a hypertext-like on-line documentation system (DOC), and a simulator input preprocessor (SIMPLSIM). RDS creates displays of reservoir simulation results. These displays represent the areal or cross-section distribution of computer reservoir parameters, such as pressure, phase saturation, or temperature. Generation of these images at real-time animation rates is discussed. FRED facilitates the creation of plot files from reservoir simulation output. The use of dynamic memory allocation, asynchronous I/O, amore » table-driven screen manager, and mixed-language (FORTRAN and C) programming are detailed. DOC is used to create and access on-line documentation for the pre-and post-processing programs and the reservoir simulators. DOC can be run by itself or can be accessed from within any other graphics or nongraphics application program. DOC includes a text editor, which is that basis for a reservoir simulation tutorial and greatly simplifies the preparation of simulator input. The use of sharable images, graphics, and the documentation file network are described. Finally, SIMPLSIM is a suite of program that uses interactive graphics in the preparation of reservoir description data for input into reservoir simulators. The SIMPLSIM user-interface manager (UIM) and its graphic interface for reservoir description are discussed.« less

Respondent-driven sampling on the Thailand-Cambodia border. II. Knowledge, perception, practice and treatment-seeking behaviour of migrants in malaria endemic zones

PubMed Central

2011-01-01

Background Population movements along the Thailand-Cambodia border, particularly among highly mobile and hard-to-access migrant groups from Cambodia and Myanmar, are assumed to play a key role in the spread of artemisinin resistance. Data on treatment-seeking behaviours, knowledge and perceptions about malaria, and use of preventive measures is lacking as characteristics of this population prevent them from being represented in routine surveillance and the lack of a sampling frame makes reliable surveys challenging. Methods A survey of migrant populations from Cambodia and Myanmar was implemented in five selected rural locations in Thailand along the Thai-Cambodian border using respondent driven sampling (RDS) to determine demographic characteristics of the population, migratory patterns, knowledge about malaria, and health-care -seeking behaviours. Results The majority of migrants from Myanmar are long-term residents (98%) with no plans to move back to Myanmar, understand spoken Thai (77%) and can therefore benefit from health messages in Thai, have Thai health insurance (99%) and accessed public health services in Thailand (63%) for their last illness. In comparison, the majority of Cambodian migrants are short-term (72%). Of the short-term Cambodian migrants, 92% work in agriculture, 18% speak Thai, 3.4% have Thai health insurance, and the majority returned to Cambodia for treatment (45%), self-treated (11%), or did not seek treatment for their last illness (27%). Conclusion Most highly mobile migrants along the Thai-Cambodia border are not accessing health messages or health treatment in Thailand, increasing their risk of malaria and facilitating the spread of potentially resistant Plasmodium falciparum as they return to Cambodia to seek treatment. Reaching out to highly mobile migrants with health messaging they can understand and malaria diagnosis and treatment services they can access is imperative in the effort to contain the spread of artemisinin-resistant P. falciparum. PMID:21554711

RDS - A systematic approach towards system thermal hydraulics input code development for a comprehensive deterministic safety analysis

NASA Astrophysics Data System (ADS)

Salim, Mohd Faiz; Roslan, Ridha; Ibrahim, Mohd Rizal Mamat @

2014-02-01

Deterministic Safety Analysis (DSA) is one of the mandatory requirements conducted for Nuclear Power Plant licensing process, with the aim of ensuring safety compliance with relevant regulatory acceptance criteria. DSA is a technique whereby a set of conservative deterministic rules and requirements are applied for the design and operation of facilities or activities. Computer codes are normally used to assist in performing all required analysis under DSA. To ensure a comprehensive analysis, the conduct of DSA should follow a systematic approach. One of the methodologies proposed is the Standardized and Consolidated Reference Experimental (and Calculated) Database (SCRED) developed by University of Pisa. Based on this methodology, the use of Reference Data Set (RDS) as a pre-requisite reference document for developing input nodalization was proposed. This paper shall describe the application of RDS with the purpose of assessing its effectiveness. Two RDS documents were developed for an Integral Test Facility of LOBI-MOD2 and associated Test A1-83. Data and information from various reports and drawings were referred in preparing the RDS. The results showed that by developing RDS, it has made possible to consolidate all relevant information in one single document. This is beneficial as it enables preservation of information, promotes quality assurance, allows traceability, facilitates continuous improvement, promotes solving of contradictions and finally assisting in developing thermal hydraulic input regardless of whichever code selected. However, some disadvantages were also recognized such as the need for experience in making engineering judgments, language barrier in accessing foreign information and limitation of resources. Some possible improvements are suggested to overcome these challenges.

Investigating the relationship between lentil carbohydrate fractions and in vivo postprandial blood glucose response by use of the natural variation in starch fractions among 20 lentil varieties.

PubMed

Ramdath, D Dan; Liu, Qiang; Donner, Elizabeth; Hawke, Aileen; Kalinga, Danusha; Winberg, Jordan; Wolever, Thomas M S

2017-10-18

Consumption of pulses is associated with many health benefits by mechanisms that are not fully understood. This study sought to identify the starch component(s) in cooked lentils responsible for lowering postprandial glycemic response (PPGR). Rapidly digestible (RDS), slowly digestible (SDS) and resistant starch (RS) content of 20 varieties of cooked lentil were determined by in vitro methods and 8 varieties, representing a linear range of SDS, were chosen for a human trial with 10 participants to determine PPGR and glycemic index (GI). Among the 20 lentil varieties, RS accounted for 35% of the variation of in vitro area under the starch hydrolysis curve (SHAUC) (r = -0.587; p < 0.01), but RDS (r = 0.401; p = 0.080) and SDS (r = -0.022; p = 0.927) were not significantly related to SHAUC. Multiple linear regression of in vitro data resulted in an equation [SHAUCest = 30.9RDS - 63.6RS + 9680] that accounted for 70% of the variance in SHAUC, with SDS excluded due to collinearity. In the human trial all 8 lentils had low GI values (10 to 23). Neither GI nor area under the glucose response curve (AUC) was significantly related to RDS, SDS or RS (minimum p = 0.24). However, SHAUC and SHAUCest, respectively, were related to both GI (r = 0.704, p = 0.051; r = 0.773, p = 0.024) and AUC (r = 0.765, p = 0.027; r = 0.822, p = 0.012). These results confirm that lentils have low GI values, which is not reliably predicted by their RDS, SDS and RS contents when considered individually. However, in vitro SHAUC and a combination of RDS and RS may be predictive of the PPGR of lentils.

Exogenous surfactant therapy in 2013: what is next? who, when and how should we treat newborn infants in the future?

PubMed Central

2013-01-01

Background Surfactant therapy is one of the few treatments that have dramatically changed clinical practice in neonatology. In addition to respiratory distress syndrome (RDS), surfactant deficiency is observed in many other clinical situations in term and preterm infants, raising several questions regarding the use of surfactant therapy. Objectives This review focuses on several points of interest, including some controversial or confusing topics being faced by clinicians together with emerging or innovative concepts and techniques, according to the state of the art and the published literature as of 2013. Surfactant therapy has primarily focused on RDS in the preterm newborn. However, whether this treatment would be of benefit to a more heterogeneous population of infants with lung diseases other than RDS needs to be determined. Early trials have highlighted the benefits of prophylactic surfactant administration to newborns judged to be at risk of developing RDS. In preterm newborns that have undergone prenatal lung maturation with steroids and early treatment with continuous positive airway pressure (CPAP), the criteria for surfactant administration, including the optimal time and the severity of RDS, are still under discussion. Tracheal intubation is no longer systematically done for surfactant administration to newborns. Alternative modes of surfactant administration, including minimally-invasive and aerosolized delivery, could thus allow this treatment to be used in cases of RDS in unstable preterm newborns, in whom the tracheal intubation procedure still poses an ethical and medical challenge. Conclusion The optimization of the uses and methods of surfactant administration will be one of the most important challenges in neonatal intensive care in the years to come. PMID:24112693

Differences in Experiences With Care Between Homeless and Nonhomeless Patients in Veterans Affairs Facilities With Tailored and Nontailored Primary Care Teams.

PubMed

Jones, Audrey L; Hausmann, Leslie R M; Kertesz, Stefan; Suo, Ying; Cashy, John P; Mor, Maria K; Schaefer, James H; Gundlapalli, Adi V; Gordon, Adam J

2018-05-12

Homeless patients describe poor experiences with primary care. In 2012, the Veterans Health Administration (VHA) implemented homeless-tailored primary care teams (Homeless Patient Aligned Care Team, HPACTs) that could improve the primary care experience for homeless patients. To assess differences in primary care experiences between homeless and nonhomeless Veterans receiving care in VHA facilities that had HPACTs available (HPACT facilities) and in VHA facilities lacking HPACTs (non-HPACT facilities). We used multivariable multinomial regressions to estimate homeless versus nonhomeless patient differences in primary care experiences (categorized as negative/moderate/positive) reported on a national VHA survey. We compared the homeless versus nonhomeless risk differences (RDs) in reporting negative or positive experiences in 25 HPACT facilities versus 485 non-HPACT facilities. Survey respondents from non-HPACT facilities (homeless: n=10,148; nonhomeless: n=309,779) and HPACT facilities (homeless: n=2022; nonhomeless: n=20,941). Negative and positive experiences with access, communication, office staff, provider rating, comprehensiveness, coordination, shared decision-making, and self-management support. In non-HPACT facilities, homeless patients reported more negative and fewer positive experiences than nonhomeless patients. However, these patterns of homeless versus nonhomeless differences were reversed in HPACT facilities for the domains of communication (positive experience RDs in non-HPACT versus HPACT facilities=-2.0 and 2.0, respectively); comprehensiveness (negative RDs=2.1 and -2.3), shared decision-making (negative RDs=1.2 and -1.8), and self-management support (negative RDs=0.1 and -4.5; positive RDs=0.5 and 8.0). VHA facilities with HPACT programs appear to offer a better primary care experience for homeless versus nonhomeless Veterans, reversing the pattern of relatively poor primary care experiences often associated with homelessness.

Writing Disabilities and Reading Disabilities in Elementary School Students

ERIC Educational Resources Information Center

Costa, Lara-Jeane C.; Edwards, Crystal N.; Hooper, Stephen R.

2016-01-01

This longitudinal study was conducted to determine (a) the rate of co-occurrence of reading disabilities (RDs) in a writing disability (WD) population of students followed from first grade to fourth grade and (b) the cognitive burden that is assumed by having a WD and a RD (WD + RD). The sample included 137 first-grade students from a single…

Cross-sectional study of female sex workers in Soweto, South Africa: Factors associated with HIV infection

PubMed Central

2017-01-01

Introduction In South Africa, the rate of HIV in the sex worker (SW) population is exceedingly high, but critical gaps exist in our understanding of SWs and the factors that make them vulnerable to HIV. This study aimed to estimate HIV prevalence among female sex workers (FSWs) in Soweto, South Africa, and to describe their sexual behavior and other factors associated with HIV infection. Methods A cross-sectional, respondent-driven sampling (RDS) recruitment methodology was used to enroll 508 FSWs based in Soweto. Data were collected using a survey instrument, followed by two HIV rapid tests. Raw and RDS adjusted data were analyzed using a chi-squared test of association and multivariate logistic regression to show factors associated with HIV infection. Findings HIV prevalence among FSWs was 53.6% (95% CI 47.5–59.9). FSWs were almost exclusively based in taverns (85.6%) and hostels (52.0%). Less than a quarter (24.4%) were under 25 years of age. Non-partner violence was reported by 55.5%, 59.6% of whom were HIV-infected. Advancing age, incomplete secondary schooling, migrancy and multiple clients increased the likelihood of HIV acquisition: >30 years of age was associated with a 4.9 times (95% CI 2.6–9.3) increased likelihood of HIV; incomplete secondary schooling almost tripled the likelihood (AOR 2.8, 95% CI 1.6–5.0); being born outside of the Gauteng province increased the likelihood of HIV 2.3 times (95% CI 1.3–4.0); and having more than five clients per day almost doubled the likelihood (AOR 1.9, 95% CI 1.1–3.2). Conclusion Our findings highlight the extreme vulnerability of FSWs to HIV. Advancing age, limited education and multiple clients were risk factors associated with HIV, strongly driven by a combination of structural, biological and behavioral determinants. Evidence suggests that interventions need to be carefully tailored to the varying profiles of SW populations across South Africa. Soweto could be considered a microcosm of South Africa in terms of the epidemic of violence and HIV experienced by the SW population, which is influenced by factors often beyond an individual level of control. While describing a hitherto largely undocumented population of FSWs, our findings confirm the urgent need to scale up innovative HIV prevention and treatment programs for this population. PMID:28981511

Oncology Nurse Navigation: Results of the 2016 Role Delineation Study.

PubMed

Lubejko, Barbara G; Bellfield, Sonia; Kahn, Elisa; Lee, Carrie; Peterson, Nicole; Rose, Traudi; Murphy, Cynthia Miller; McCorkle, Michele

2017-02-01

In 2011, an oncology nurse navigator (ONN) role delineation survey (RDS) was conducted by the Oncology Nursing Society (ONS) when the role was relatively new to oncology. Results did not demonstrate a unique skill set for the ONN; however, since then, the role has expanded. ONS and the Oncology Nursing Certification Corporation partnered in 2016 to complete an RDS of ONNs to redefine the role and determine the need for an ONN certification examination. A structured RDS was conducted using a formal consensus-building process. A survey was developed and released to examine the specific tasks, knowledge, and skills for the ONN as well as to determine which role possesses more responsibility for the tasks. The ONN role is evolving, and more was learned about its key tasks, including differences in the responsibilities of the ONN and the clinical or staff nurse. However, the RDS did not find an adequate difference in the knowledge required by the ONN and the clinical or staff nurse to support the need for a separate ONN certification.

Respiratory distress syndrome and birth order in premature twins

PubMed Central

Hacking, D; Watkins, A; Fraser, S; Wolfe, R; Nolan, T

2001-01-01

OBJECTIVE—To determine the effect of birth order on respiratory distress syndrome (RDS) in the outcome of twins in a large premature population managed in a modern neonatal intensive care unit.
METHODS—An historical cohort study design was used to analyse the neonatal outcomes of 301 premature liveborn twin sibling pairs of between 23 and 31 weeks gestation from the Australia and New Zealand Neonatal Network 1995database.
RESULTS—Among the 56 twin sibling pairs who were discordant for RDS, the second twin was affected in 41 cases (odds ratio (OR) 2.7,95% confidence interval (CI) 1.5 to 5.3). The excess risk of RDS in the second twin increased with gestation and was statistically significant for twins above 29 weeks gestation (OR 4.4, 95% CI 1.6 to 15).
CONCLUSIONS—There is a significant increased risk of RDS associated with being the second born of premature twins, which appears to depend on gestation.

 PMID:11207228

Permissive norms and young adults' alcohol and marijuana use: the role of online communities.

PubMed

Stoddard, Sarah A; Bauermeister, Jose A; Gordon-Messer, Deborah; Johns, Michelle; Zimmerman, Marc A

2012-11-01

Young adults are increasingly interacting with their peer groups online through social networking sites. These online interactions may reinforce or escalate alcohol and other drug (AOD) use as a result of more frequent and continuous exposure to AOD promotive norms; however, the influence of young adults' virtual networks on AOD use remains untested. The purpose of this study was to examine the association between the presence of AOD use content in online social networking, perceived norms (online norms regarding AOD use and anticipated regret with AOD use postings), and alcohol and marijuana use in a sample of 18- to 24-year-olds. Using an adapted web version of respondent-driven sampling (webRDS), we recruited a sample of 18- to 24-year-olds (N = 3,448) in the United States. Using multivariate regression, we explored the relationship between past-30-day alcohol and marijuana use, online norms regarding AOD use, peer substance use, and online and offline peer support. Alcohol use was associated with more alcohol content online. Anticipated regret and online peer support were associated with less alcohol use. Anticipated regret was negatively associated with marijuana use. Peer AOD use was positively associated with both alcohol and marijuana use. Peers play an important role in young adult alcohol and marijuana use, whether online or in person. Our findings highlight the importance of promoting online network-based AOD prevention programs for young adults in the United States.

Validation of holistic nursing competencies: role-delineation study, 2012.

PubMed

Erickson, Helen Lorraine; Erickson, Margaret Elizabeth; Campbell, Joan A; Brekke, Mary E; Sandor, M Kay

2013-12-01

The American Holistic Nurses Credentialing Corporation (AHNCC), certifying body for nurses practicing within the precepts of holistic nursing, uses a systematic process to guide program development. A previous publication described their early work that distinguished basic and advanced holistic nursing and development of related examinations. A more recent publication described the work of AHNCC from 2004 to 2012, including a role-delineation study (RDS) that was undertaken to identify and validate competencies currently used by holistic nurses. A final report describes the RDS design, methods, and raw data information. This article discusses AHNCC's goals for undertaking the 2012 Holistic Nursing RDS and the implications for the certification programs.

Virgil Gus Grissom's Visit to LaRC

NASA Image and Video Library

1963-02-22

Astronaut Virgil "Gus" Grissom at the controls of the Visual Docking Simulator. From A.W. Vogeley, "Piloted Space-Flight Simulation at Langley Research Center," Paper presented at the American Society of Mechanical Engineers 1966 Winter Meeting, New York, NY, November 27-December 1, 1966. "This facility was [later known as the Visual-Optical Simulator.] It presents to the pilot an out-the-window view of his target in correct 6 degrees of freedom motion. The scene is obtained by a television camera pick-up viewing a small-scale gimbaled model of the target." "For docking studies, the docking target picture was projected onto the surface of a 20-foot-diameter sphere and the pilot could, effectively, maneuver into contract. this facility was used in a comparison study with the Rendezvous Docking Simulator - one of the few comparison experiments in which conditions were carefully controlled and a reasonable sample of pilots used. All pilots preferred the more realistic RDS visual scene. The pilots generally liked the RDS angular motion cues although some objected to the false gravity cues that these motions introduced. Training time was shorter on the RDS, but final performance on both simulators was essentially equal. " "For station-keeping studies, since close approach is not required, the target was presented to the pilot through a virtual-image system which projects his view to infinity, providing a more realistic effect. In addition to the target, the system also projects a star and horizon background. "

High burden of HCV disease and poor access to HCV services among people who inject drugs in India: A cross-sectional study among 14,481 drug users across India

PubMed Central

Solomon, Sunil Suhas; Mehta, Shruti H; Srikrishnan, Aylur K; Solomon, Suniti; McFall, Allison M.; Laeyendecker, Oliver; Celentano, David D; Iqbal, Syed H; Anand, Santhanam; Vasudevan, Canjeevaram K; Saravanan, Shanmugam; Lucas, Gregory M; Kumar, Muniratnam S; Sulkowski, Mark S; Quinn, Thomas C

2014-01-01

Background Globally, 90% of HCV-infected individuals reside in resource-limited settings (RLS). We characterized the prevalence of HCV, HIV/HCV co-infection, and the HCV care continuum among people who inject drugs (PWID) in India. Methods 14,481 PWID were sampled from 15 cities throughout India using respondent-driven sampling (RDS) from January–December 2013. HCV prevalence was estimated by the presence of anti-HCV antibodies incorporating RDS weights. HCV care continuum outcomes were self-reported except for viral clearance among treatment-experienced participants. Findings Median age was 30 years and 13,608/14,449 (92·4%) were male. Overall weighted HCV prevalence was 37·2% (5,777/14,447); HIV/HCV co-infection prevalence was 13·2% (2,085/14,435). Correlates of HCV infection included higher lifetime injection frequency, HIV positivity, and a higher prevalence of persons with HIV RNA > 1000 copies/ml in the community. Of 5,777 HCV antibody positive PWID, 440 (5·5%) were aware of their status, 225 (3·0%) had seen a doctor for their HCV, 79 (1·4%) had taken HCV treatment, and 18 (0·4%) had undetectable HCV RNA. Overall, 6,138/12,128 (50·5%) did not get tested for HCV because they had never heard of HCV. Among the 5,777 HCV antibody positives, 2,086 (34·4%) reported harmful/hazardous alcohol use of whom 1,082 (50·4%) were dependent; 3,007 (52.9%) reported recent needle sharing. Awareness of HCV positive status was significantly associated with higher education, HIV testing history, awareness of HIV positive status, and higher community antiretroviral therapy coverage. Interpretation The high burden of HCV and HIV/HCV co-infection coupled with low-access to HCV services highlights an urgent need to include RLS in the global HCV agenda. While newer treatments will become available globally in the near future, programs to improve awareness, and reduce disease progression and transmission need to be scaled-up without further delay. Failure to do so could result in patterns of rising mortality, undermining advances in survival attributed to widespread HIV treatment. Funding US National Institutes of Health PMID:25486851

Seroadaptive Strategies of Gay & Bisexual Men (GBM) With the Highest Quartile Number of Sexual Partners in Vancouver, Canada

PubMed Central

Card, Kiffer G.; Lachowsky, Nathan J; Cui, Zishan; Sereda, Paul; Rich, Ashleigh; Jollimore, Jody; Howard, Terry; Birch, Robert; Carter, Allison; Montaner, Julio; Moore, David; Hogg, Robert S.; Roth, Eric Abella

2017-01-01

Despite continued research among men with more sexual partners, little information exists on their seroadaptive behavior. Therefore, we examined seroadaptive anal sex strategies among 719 Vancouver gay and bisexual men (GBM) recruited using respondent driven sampling (RDS). Our objectives were to (1) describe the distribution in frequency of male sexual partnering among Vancouver GBM, and (2) identify important covariates associated with the number of male sexual partners. To this aims, we provide descriptive, univariate, and multivariate adjusted statistics, stratified by HIV status, for the association between having ≥7 male anal sex partners in the past six months (Population Q3, versus <7). Sensitivity Analysis were also performed to assess the robustness of this cut-off point. Results suggest that GBM with more sexual partners are more likely to employ seroadaptive strategies than men with fewer partners. These strategies may be used in hopes of offsetting risk, assessing needs for subsequent HIV testing, and balancing personal health with sexual intimacy. Further research is needed to determine the efficacy of these strategies, assess how GBM perceive their efficacy, and understand the social and health impacts of their widespread uptake. PMID:27568338

The Silk Road Health Project: How Mobility and Migration Status Influence HIV Risks among Male Migrant Workers in Central Asia.

PubMed

El-Bassel, Nabila; Gilbert, Louisa; Shaw, Stacey A; Mergenova, Gaukhar; Terlikbayeva, Assel; Primbetova, Sholpan; Ma, Xin; Chang, Mingway; Ismayilova, Leyla; Hunt, Tim; West, Brooke; Wu, Elwin; Beyrer, Chris

2016-01-01

We examined whether mobility, migrant status, and risk environments are associated with sexually transmitted infections (STIs) and HIV risk behaviors (e.g. sex trading, multiple partners, and unprotected sex). We used Respondent Driven Sampling (RDS) to recruit external male migrant market vendors from Kyrgyzstan, Uzbekistan, and Tajikistan as well internal migrant and non-migrant market vendors from Kazakhstan. We conducted multivariate logistic regressions to examine the effects of mobility combined with the interaction between mobility and migration status on STIs and sexual risk behaviors, when controlling for risk environment characteristics. Mobility was associated with increased risk for biologically-confirmed STIs, sex trading, and unprotected sex among non-migrants, but not among internal or external migrants. Condom use rates were low among all three groups, particularly external migrants. Risk environment factors of low-income status, debt, homelessness, and limited access to medical care were associated with unprotected sex among external migrants. Study findings underscore the role mobility and risk environments play in shaping HIV/STI risks. They highlight the need to consider mobility in the context of migration status and other risk environment factors in developing effective prevention strategies for this population.

Heavy episodic drinking among transgender persons: Disparities and predictors.

PubMed

Scheim, Ayden I; Bauer, Greta R; Shokoohi, Mostafa

2016-10-01

Drawing on a survey of transgender people in Canada's most populous province, we estimate the frequency of heavy episodic drinking (HED), compare HED prevalence to the age-standardized background population, and examine associations with socio-demographics, gender transition, and social exclusion. 433 transgender persons aged 16+ completed a respondent-driven sampling survey in 2009-2010. Analyses were weighted using RDS II methods, including frequencies and prevalence ratios. Overall and sex-specific estimates of HED among Ontario residents in the 2009-2010 Canadian Community Health Survey (n=39,980) were standardized to the overall and gender-specific transgender age distributions. Estimated prevalence of HED at least monthly among transgender Ontarians was 33.2% (95% CI: 26.3, 40.1), 1.5 times greater than expected based on the age-standardized Ontario population. Transmasculine (female-to-male spectrum) persons were more likely than transfeminine persons to report HED (42.2% versus 22.7%), an effect robust to covariate adjustment. Current sex work was associated with greater HED, but gender transition and social exclusion factors were not. Gendered pathways to alcohol misuse, particularly among transmasculine persons, warrant further research and intervention development. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Homophobia and racism experienced by Latino men who have sex with men in the United States: correlates of exposure and associations with HIV risk behaviors.

PubMed

Mizuno, Yuko; Borkowf, Craig; Millett, Gregorio A; Bingham, Trista; Ayala, George; Stueve, Ann

2012-04-01

Using cross-sectional data collected from 1081 Latino men who have sex with men (MSM) recruited with respondent-driven sampling (RDS) techniques from Los Angeles and New York, we examined the extent to which Latino MSM reported exposure to social discrimination (i.e., experienced both homophobia and racism, homophobia only, racism only, or neither homophobia nor racism). More than 40% of respondents experienced both homophobia and racism in the past 12 months. Los Angeles participants, those with lower income, and those who reported being HIV-positive were more likely to report experiencing both types of social discrimination. Adjusting for potential confounders, men exposed to both homophobia and racism were more likely than men exposed to neither form of discrimination to report unprotected receptive anal intercourse with a casual sex partner (AOR = 1.92, 95% CI, 1.18-3.24) and binge drinking (AOR = 1.42, 95% CI, 1.02-1.98). Our findings suggest the presence of a syndemic of adverse social experiences and call for more intervention research to address both homophobia and racism experienced among Latino MSM in the United States.

Cytokine gene polymorphisms in Italian preterm infants: association between interleukin-10 -1082 G/A polymorphism and respiratory distress syndrome.

PubMed

Capasso, Mario; Avvisati, Rosa Anna; Piscopo, Carmelo; Laforgia, Nicola; Raimondi, Francesco; de Angelis, Filomena; Iolascon, Achille

2007-03-01

In this study, we determined the genotype frequencies of polymorphisms of cytokine genes and investigated their association with the risk of respiratory distress syndrome (RDS) in preterm infants. Genetic polymorphisms in the cytokines interleukin (IL)-10, IL-8, and tumor necrosis factor (TNF) alpha, were studied in 342 white Italian newborns (112 without RDS, 66 prematurely born with RDS, and 164 infants born at term who were included as healthy controls). The polymorphisms were analyzed by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP). The IL-10 mRNA levels were analyzed according to genotype by quantitative real-time PCR (QRT-PCR) in Epstein-Barr virus-transformed lymphoblastoid cell lines (EBV-LCLs) of 42 full-term healthy infants. Logistic regression analysis demonstrated the risk of RDS to be significantly lower in preterm infants with an IL-10 -1082 GG/GA genotype than in those with an AA genotype [odds ratio (OR) = 0.48, 95% confidence interval (CI): 0.24-0.95, p = 0.03]. QRT-PCR analyses showed that the IL-10 mRNA levels were significantly higher in 27 IL-10 -1082 GG/GA carriers compared with 15 IL-10 -1082 AA carriers (p = 0.03). We conclude that the IL-10 -1082 GG/GA polymorphism may have a role in RDS development in premature infants.

Mode of delivery and neonatal respiratory morbidity among HIV-exposed newborns in Latin America and the Caribbean: NISDI Perinatal–LILAC Studies

PubMed Central

Kreitchmann, Regis; Cohen, Rachel A.; Stoszek, Sonia K.; Pinto, Jorge A.; Losso, Marcelo; Pierre, Russell; Alarcon, Jorge; Succi, Regina; Szyld, Edgardo; Abreu, Thalita; Read, Jennifer S.

2012-01-01

Objective To evaluate respiratory morbidity (RM) in HIV-exposed newborns according to mode of delivery. Methods The NISDI Perinatal/LILAC prospective cohort studies enrolled HIV-infected pregnant women and their newborns in Latin America and the Caribbean. Associations between RM and delivery mode or other characteristics were evaluated. Results Between September 2002 and December 2009, 1630 women were enrolled, and 1443 mother–infant pairs met the inclusion criteria. There were 561 vaginal (VD), 269 cesarean before labor and membrane rupture (SCS) for preventing mother-to-child transmission (SCS–PMTCT), 248 other SCS, and 365 cesarean after labor and/or ruptured membranes (NSCS) deliveries. In total, 108 (7.5%) newborns had RM: 49 had respiratory distress syndrome (RDS), 39 had transient tachypnea (TTN), and 28 had other events (7 newborns had >1 RM event). Delivery mode was associated with RDS (P<0.001) and TTN (P<0.001). The proportion with RDS and TTN was lowest for VD (1.6% and 0.5%, respectively), highest for NSCS (4.9% and 4.7%), and intermediate for SCS–PMTCT (3.0% and 2.6%). Newborns with RDS or TTN were hospitalized longer (median +1 day) than those without. A minority required ventilatory support (RDS, 24.5%–28.6%; TTN, 2.6–15.4%). Conclusions SCS–PMTCT is relatively safe for newborns of HIV-infected women. PMID:21620404

Men at risk; a qualitative study on HIV risk, gender identity and violence among men who have sex with men who report high risk behavior in Kampala, Uganda.

PubMed

King, Rachel; Barker, Joseph; Nakayiwa, Sylvia; Katuntu, David; Lubwama, George; Bagenda, Danstan; Lane, Tim; Opio, Alex; Hladik, Wolfgang

2013-01-01

In Uganda, men who have sex with men (MSM) are at high risk for HIV. Between May 2008 and February 2009 in Kampala, Uganda, we used respondent driven sampling (RDS) to recruit 295 MSM≥18 years who reported having had sex with another man in the preceding three months. The parent study conducted HIV and STI testing and collected demographic and HIV-related behavioral data through audio computer-assisted self-administered interviews. We conducted a nested qualitative sub-study with 16 men purposively sampled from among the survey participants based on responses to behavioral variables indicating higher risk for HIV infection. Sub-study participants were interviewed face-to-face. Domains of inquiry included sexual orientation, gender identity, condom use, stigma, discrimination, violence and health seeking behavior. Emergent themes included a description of sexual orientation/gender identity categories. All groups of men described conflicting feelings related to their sexual orientation and contextual issues that do not accept same-sex identities or behaviors and non-normative gender presentation. The emerging domains for facilitating condom use included: lack of trust in partner and fear of HIV infection. We discuss themes in the context of social and policy issues surrounding homosexuality and HIV prevention in Uganda that directly affect men's lives, risk and health-promoting behaviors.

Men at Risk; a Qualitative Study on HIV Risk, Gender Identity and Violence among Men Who Have Sex with Men Who Report High Risk Behavior in Kampala, Uganda

PubMed Central

King, Rachel; Barker, Joseph; Nakayiwa, Sylvia; Katuntu, David; Lubwama, George; Bagenda, Danstan; Lane, Tim; Opio, Alex; Hladik, Wolfgang

2013-01-01

In Uganda, men who have sex with men (MSM) are at high risk for HIV. Between May 2008 and February 2009 in Kampala, Uganda, we used respondent driven sampling (RDS) to recruit 295 MSM≥18 years who reported having had sex with another man in the preceding three months. The parent study conducted HIV and STI testing and collected demographic and HIV-related behavioral data through audio computer-assisted self-administered interviews. We conducted a nested qualitative sub-study with 16 men purposively sampled from among the survey participants based on responses to behavioral variables indicating higher risk for HIV infection. Sub-study participants were interviewed face-to-face. Domains of inquiry included sexual orientation, gender identity, condom use, stigma, discrimination, violence and health seeking behavior. Emergent themes included a description of sexual orientation/gender identity categories. All groups of men described conflicting feelings related to their sexual orientation and contextual issues that do not accept same-sex identities or behaviors and non-normative gender presentation. The emerging domains for facilitating condom use included: lack of trust in partner and fear of HIV infection. We discuss themes in the context of social and policy issues surrounding homosexuality and HIV prevention in Uganda that directly affect men's lives, risk and health-promoting behaviors. PMID:24358239

Math Disabilities and Reading Disabilities: Can They Be Separated?

ERIC Educational Resources Information Center

Swanson, H. Lee; Jerman, Olga; Zheng, Xinhua

2009-01-01

This article synthesizes some of the published literature that selectively compares the cognitive functioning of children with math disabilities (MDs) with average-achieving children and poor readers (children with reading disabilities [RDs] or comorbid disabilities [RDs + MDs]). All studies in the synthesis report reading, IQ, and math scores for…

[Pulmonary surfactants: in vivo structure and in vitro biophysical models for investigation and its perspectives].

PubMed

Lalchev, Z; Khristova, E; Vasiliev, Kh; Todorov, R; Ekserova, D

2007-01-01

The metabolism, composition, structure and functions of the alveolar surfactant (AS) are described. The most adequate biophysical models for investigation of AS are considered. The principals and possibilities of three mostly used models are described in details: Monolayers, Spinning drop method and Thin liquid films. Some of the studies of Bulgarian biophysical, physicochemical, biochemical and medical groups on the structure and mechanism of action of AS in vivo using samples of amniotic fluid (AF), animal pulmonary lavages (PL) and tracheal aspirates (TA) of newborns and adults are summarized. The role of specific surfactant proteins (SP-A, SP-B, SP-C and SP-D) on the properties and function of AS is demonstrated. The opportunities of the model investigations for application in laboratory pre- and postnatal diagnosis of the respiratory distress syndrome (RDS), as well as for the efficiency of RDS therapy during exogenous surfactant therapy with ALEC (UK), Survanta (USA), Exosurf (USA), Curosurf (Italy) u Alveofact (Germany) are considered.

Approaches to Recruiting 'Hard-To-Reach' Populations into Re-search: A Review of the Literature.

PubMed

Shaghaghi, Abdolreza; Bhopal, Raj S; Sheikh, Aziz

2011-01-01

'Hard-to-reach' is a term used to describe those sub-groups of the population that may be difficult to reach or involve in research or public health programmes. Application of a single term to call these sub-sections of populations implies a homogeneity within distinct groups, which does not necessarily exist. Different sampling techniques were introduced so far to recruit hard-to-reach populations. In this article, we have reviewed a range of ap-proaches that have been used to widen participation in studies. We performed a Pubmed and Google search for relevant English language articles using the keywords and phrases: (hard-to-reach AND population* OR sampl*), (hidden AND population* OR sample*) and ("hard to reach" AND population* OR sample*) and a consul-tation of the retrieved articles' bibliographies to extract empirical evidence from publications that discussed or examined the use of sampling techniques to recruit hidden or hard-to-reach populations in health studies. Reviewing the literature has identified a range of techniques to recruit hard-to-reach populations, including snowball sampling, respondent-driven sampling (RDS), indigenous field worker sampling (IFWS), facility-based sampling (FBS), targeted sampling (TS), time-location (space) sampling (TLS), conventional cluster sampling (CCS) and capture re-capture sampling (CR). The degree of compliance with a study by a certain 'hard-to-reach' group de-pends on the characteristics of that group, recruitment technique used and the subject of inter-est. Irrespective of potential advantages or limitations of the recruitment techniques reviewed, their successful use depends mainly upon our knowledge about specific characteristics of the target populations. Thus in line with attempts to expand the current boundaries of our know-ledge about recruitment techniques in health studies and their applications in varying situa-tions, we should also focus on possibly all contributing factors which may have an impact on participation rate within a defined population group.

Use of the Wechsler Adult Intelligence Scale Digit Span subtest for malingering detection: a meta-analytic review.

PubMed

Jasinski, Lindsey J; Berry, David T R; Shandera, Anni L; Clark, Jessica A

2011-03-01

Twenty-four studies utilizing the Wechsler Adult Intelligence Scale (WAIS) Digit Span subtest--either the Reliable Digit Span (RDS) or Age-Corrected Scaled Score (DS-ACSS) variant--for malingering detection were meta-analytically reviewed to evaluate their effectiveness in detecting malingered neurocognitive dysfunction. RDS and DS-ACSS effectively discriminated between honest responders and dissimulators, with average weighted effect sizes of 1.34 and 1.08, respectively. No significant differences were found between RDS and DS-ACSS. Similarly, no differences were found between the Digit Span subtest from the WAIS or Wechsler Memory Scale (WMS). Strong specificity and moderate sensitivity were observed, and optimal cutting scores are recommended.

Heavy metals in the finest size fractions of road-deposited sediments.

PubMed

Lanzerstorfer, Christof

2018-08-01

The concentration of heavy metals in urban road-deposited sediments (RDS) can be used as an indicator for environmental pollution. Thus, their occurrence has been studied in whole road dust samples as well as in size fractions obtained by sieving. Because of the limitations of size separation by sieving little information is available about heavy metal concentrations in the road dust size fractions <20 μm. In this study air classification was applied for separation of dust size fractions smaller than 20 μm from RDS collected at different times during the year. The results showed only small seasonal variations in the heavy metals concentrations and size distribution. According to the Geoaccumulation Index the pollution of the road dust samples deceased in the following order: Sb » As > Cu ≈ Zn > Cr > Cd ≈ Pb ≈ Mn > Ni > Co ≈ V. For all heavy metals the concentration was higher in the fine size fractions compared to the coarse size fractions, while the concentration of Sr was size-independent. The enrichment of the heavy metals in the finest size fraction compared to the whole RDS <200 μm was up to 4.5-fold. The size dependence of the concentration decreased in the following order: Co ≈ Cd > Sb > (Cu) ≈ Zn ≈ Pb > As ≈ V » Mn. The approximation of the size dependence of the concentration as a function of the particle size by power functions worked very well. The correlation between particle size and concentration was high for all heavy metals. The increased heavy metals concentrations in the finest size fractions should be considered in the evaluation of the contribution of road dust re-suspension to the heavy metal contamination of atmospheric dust. Thereby, power functions can be used to describe the size dependence of the concentration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Minority recruitment and retention in dietetics: issues and interventions.

PubMed

Greenwald, H P; Davis, R A

2000-08-01

To better understand the reasons why minorities and males are underrepresented among registered dietitians (RDs) and dietetic technicians, registered, (DTRs) and to develop focuses for intervention, the investigators performed a telephone survey of newly credentialed RDs and DTRs and directors of RD and DTR education programs. Using lists of students recruited by the American Dietetic Association for participation in the survey, the investigators interviewed 83 RDs and DTRs and 20 education program directors. RDs and DTRs attributed minority underrepresentation primarily to the field's lack of visibility and underrepresentation of men to the traditional association with women. Education program directors attributed minority underrepresentation to educational disadvantages, particularly in scientific subjects. Findings from this study support program-level interventions such as increasing program flexibility, initiating outreach to K-12 schools and lower-division college students, providing tutoring in a nondemeaning atmosphere, and visibly expressing commitment to minority representation. More fundamental changes in the profession itself appear necessary for large-scale increases in minority representation. These include increasing internship opportunities; raising the profession's level of remuneration, prestige, and independence; increasing scholarship support; and advertising nationally through channels capable of reaching minorities.

Neuro-Genetics of Reward Deficiency Syndrome (RDS) as the Root Cause of “Addiction Transfer”: A New Phenomenon Common after Bariatric Surgery

PubMed Central

Blum, Kenneth; Bailey, John; Gonzalez, Anthony M; Oscar-Berman, Marlene; Liu, Yijun; Giordano, John; Braverman, Eric; Gold, Mark

2012-01-01

Now after many years of successful bariatric (weight-loss) surgeries directed at the obesity epidemic clinicians are reporting that some patients are replacing compulsive overeating with newly acquired compulsive disorders such as alcoholism, gambling, drugs, and other addictions like compulsive shopping and exercise. This review article explores evidence from psychiatric genetic animal and human studies that link compulsive overeating and other compulsive disorders to explain the phenomenon of addiction transfer. Possibly due to neurochemical similarities, overeating and obesity may act as protective factors reducing drug reward and addictive behaviors. In animal models of addiction withdrawal from sugar induces imbalances in the neurotransmitters, acetylcholine and dopamine, similar to opiate withdrawal. Many human neuroimaging studies have supported the concept of linking food craving to drug craving behavior. Previously our laboratory coined the term Reward Deficiency Syndrome (RDS) for common genetic determinants in predicting addictive disorders and reported that the predictive value for future RDS behaviors in subjects carrying the DRD2 Taq A1 allele was 74%. While poly genes play a role in RDS, we have also inferred that disruptions in dopamine function may predispose certain individuals to addictive behaviors and obesity. It is now known that family history of alcoholism is a significant obesity risk factor. Therefore, we hypothesize here that RDS is the root cause of substituting food addiction for other dependencies and potentially explains this recently described Phenomenon (addiction transfer) common after bariatric surgery. PMID:23483116

Neuro-Genetics of Reward Deficiency Syndrome (RDS) as the Root Cause of "Addiction Transfer": A New Phenomenon Common after Bariatric Surgery.

PubMed

Blum, Kenneth; Bailey, John; Gonzalez, Anthony M; Oscar-Berman, Marlene; Liu, Yijun; Giordano, John; Braverman, Eric; Gold, Mark

2011-12-23

Now after many years of successful bariatric (weight-loss) surgeries directed at the obesity epidemic clinicians are reporting that some patients are replacing compulsive overeating with newly acquired compulsive disorders such as alcoholism, gambling, drugs, and other addictions like compulsive shopping and exercise. This review article explores evidence from psychiatric genetic animal and human studies that link compulsive overeating and other compulsive disorders to explain the phenomenon of addiction transfer. Possibly due to neurochemical similarities, overeating and obesity may act as protective factors reducing drug reward and addictive behaviors. In animal models of addiction withdrawal from sugar induces imbalances in the neurotransmitters, acetylcholine and dopamine, similar to opiate withdrawal. Many human neuroimaging studies have supported the concept of linking food craving to drug craving behavior. Previously our laboratory coined the term Reward Deficiency Syndrome (RDS) for common genetic determinants in predicting addictive disorders and reported that the predictive value for future RDS behaviors in subjects carrying the DRD2 Taq A1 allele was 74%. While poly genes play a role in RDS, we have also inferred that disruptions in dopamine function may predispose certain individuals to addictive behaviors and obesity. It is now known that family history of alcoholism is a significant obesity risk factor. Therefore, we hypothesize here that RDS is the root cause of substituting food addiction for other dependencies and potentially explains this recently described Phenomenon (addiction transfer) common after bariatric surgery.

The Effects of PM2.5 from Asian Dust Storms on Emergency Room Visits for Cardiovascular and Respiratory Diseases.

PubMed

Liu, Ssu-Ting; Liao, Chu-Yung; Kuo, Cheng-Yu; Kuo, Hsien-Wen

2017-04-16

A case-crossover study examined how PM 2.5 from Asian Dust Storms (ADS) affects the number of emergency room (ER) admissions for cardiovascular diseases (CVDs) and respiratory diseases (RDs). Our data indicated that PM 2.5 concentration from ADS was highly correlated with ER visits for CVDs and RDs. The odds ratios (OR) increased by 2.92 (95% CI: 1.22-5.08) and 1.86 (95% CI: 1.30-2.91) per 10 µg/m³ increase in PM 2.5 levels, for CVDs and RDs, respectively. A 10 µg/m³ increase in PM 2.5 from ADSs was significantly associated with an increase in ER visits for CVDs among those 65 years of age and older (an increase of 2.77 in OR) and for females (an increase of 3.09 in OR). In contrast, PM 2.5 levels had a significant impact on RD ER visits among those under 65 years of age (OR = 1.77). The risk of ER visits for CVDs increased on the day when the ADS occurred in Taiwan and the day after (lag 0 and lag 1); the corresponding risk increase for RDs only increased on the fifth day after the ADS (lag 5). In Taiwan's late winter and spring, the severity of ER visits for CVDs and RDs increases. Environmental protection agencies should employ an early warning system for ADS to reduce high-risk groups' exposure to PM 2.5 .

Family Medicine Residency Program Directors Attitudes and Knowledge of Family Medicine CAM Competencies

PubMed Central

Gardiner, Paula; Filippelli, Amanda C.; Lebensohn, Patricia; Bonakdar, Robert

2013-01-01

Context Little is known about the incorporation of integrative medicine (IM) and complementary and alternative medicine (CAM) into family medicine residency programs. Objective The Society for Teachers of Family Medicine (STFM) approved a set of CAM/IM competencies for family medicine residencies. We hope to evaluate with an online survey tool, whether residency programs are implementing such competencies into their curriculum. We also hope to assess the knowledge and attitudes of Residency Directors (RDs) on the CAM/IM competencies. Design A survey was distributed by the CAFM (Council of Academic Family Medicine) Educational Research Alliance to RDs via email. The survey was distributed to 431 RDs. Of those who received it, 212 responded for a response rate of 49.1%. Questions assessed the knowledge and attitudes of CAM/IM competencies and incorporation of CAM/IM into residency curriculum. Results Forty-five percent of RDs were aware of the competencies. In term of RD attitudes, 58% reported that CAM/IM is an important component of residents' curriculum yet, 60% report not having specific learning objectives for CAM/IM in their residency curriculum. Among all programs, barriers to CAM/IM implementation included: time in residents' schedules (77%); faculty training (75%); access to CAM experts (43%); lack of reimbursement (43%), and financial resources (29%). Conclusions While many RDs are aware of the STFM CAM/IM competencies and acknowledge their role in residence education, there are many barriers preventing residencies to implementing the STFM CAM/IM competencies. PMID:24021471

Family medicine residency program directors attitudes and knowledge of family medicine CAM competencies.

PubMed

Gardiner, Paula; Filippelli, Amanda C; Lebensohn, Patricia; Bonakdar, Robert

2013-01-01

Little is known about the incorporation of integrative medicine (IM) and complementary and alternative medicine (CAM) into family medicine residency programs. The Society for Teachers of Family Medicine (STFM) approved a set of CAM/IM competencies for family medicine residencies. We hope to evaluate whether residency programs are implementing such competencies into their curriculum using an online survey tool. We also hope to assess the knowledge and attitudes of Residency Directors (RDs) on the CAM/IM competencies. A survey was distributed by the Council of Academic Family Medicine (CAFM) Educational Research Alliance to RDs via e-mail. The survey was distributed to 431 RDs. Of those who received it, 212 responded, giving a response rate of 49.1%. Questions assessed the knowledge and attitudes of CAM/IM competencies and incorporation of CAM/IM into the residency curriculum. Forty-five percent of RDs were aware of the competencies. In terms of RD attitudes, 58% reported that CAM/IM is an important component of residents' curriculum; yet, 60% report not having specific learning objectives for CAM/IM in their residency curriculum. Among all programs, barriers to CAM/IM implementation included time in residents' schedules (77%); faculty training (75%); access to CAM experts (43%); lack of reimbursement (43%); and financial resources (29%). While many RDs are aware of the STFM CAM/IM competencies and acknowledge their role in residence education, there are many barriers that prevent residencies from implementing the STFM CAM/IM competencies. © 2013 Elsevier Inc. All rights reserved.

Control in the Rate-Determining Step Provides a Promising Strategy To Develop New Catalysts for CO2 Hydrogenation: A Local Pair Natural Orbital Coupled Cluster Theory Study.

PubMed

Mondal, Bhaskar; Neese, Frank; Ye, Shengfa

2015-08-03

The development of efficient catalysts with base metals for CO2 hydrogenation has always been a major thrust of interest. A series of experimental and theoretical work has revealed that the catalytic cycle typically involves two key steps, namely, base-promoted heterolytic H2 splitting and hydride transfer to CO2, either of which can be the rate-determining step (RDS) of the entire reaction. To explore the determining factor for the nature of RDS, we present herein a comparative mechanistic investigation on CO2 hydrogenation mediated by [M(H)(η(2)-H2)(PP3(Ph))](n+) (M = Fe(II), Ru(II), and Co(III); PP3(Ph) = tris(2-(diphenylphosphino)phenyl)phosphine) type complexes. In order to construct reliable free energy profiles, we used highly correlated wave function based ab initio methods of the coupled cluster type alongside the standard density functional theory. Our calculations demonstrate that the hydricity of the metal-hydride intermediate generated by H2 splitting dictates the nature of the RDS for the Fe(II) and Co(III) systems, while the RDS for the Ru(II) catalyst appears to be ambiguous. CO2 hydrogenation catalyzed by the Fe(II) complex that possesses moderate hydricity traverses an H2-splitting RDS, whereas the RDS for the high-hydricity Co(III) species is found to be the hydride transfer. Thus, our findings suggest that hydricity can be used as a practical guide in future catalyst design. Enhancing the electron-accepting ability of low-hydricity catalysts is likely to improve their catalytic performance, while increasing the electron-donating ability of high-hydricity complexes may speed up CO2 conversion. Moreover, we also established the active roles of base NEt3 in directing the heterolytic H2 splitting and assisting product release through the formation of an acid-base complex.

High prevalence of non-fatal overdose among people who inject drugs in Malaysia: Correlates of overdose and implications for overdose prevention from a cross-sectional study.

PubMed

Bazazi, Alexander R; Zelenev, Alexei; Fu, Jeannia J; Yee, Ilias; Kamarulzaman, Adeeba; Altice, Frederick L

2015-07-01

Overdose is the leading cause of death among opioid users, but no data are available on overdose among people who inject drugs in Malaysia. We present the first estimates of the prevalence and correlates of recent non-fatal overdose among people who inject drugs in Malaysia. In 2010, 460 people who inject drugs were recruited using respondent-driven sampling (RDS) in Klang Valley to assess health outcomes associated with injection drug use. Self-reported history of non-fatal overdose in the previous 6 months was the primary outcome. Sociodemographic, behavioral and structural correlates of non-fatal overdose were assessed using multivariable logistic regression. All 460 participants used opioids and nearly all (99.1%) met criteria for opioid dependence. Most injected daily (91.3%) and were male (96.3%) and ethnically Malay (90.4%). Overall, 20% of participants had overdosed in the prior 6 months, and 43.3% had ever overdosed. The RDS-adjusted estimate of the 6-month period prevalence of overdose was 12.3% (95% confidence interval [CI] 7.9-16.6%). Having injected for more years was associated with lower odds of overdose (adjusted odds ratio [AOR] 0.6 per 5 years of injection, CI: 0.5-0.7). Rushing an injection from fear of the police nearly doubled the odds of overdose (AOR 1.9, CI: 1.9-3.6). Alcohol use was associated with recent non-fatal overdose (AOR 2.1, CI: 1.1-4.2), as was methamphetamine use (AOR 2.3, CI: 1.3-4.6). When adjusting for past-month drug use, intermittent but not daily methadone use was associated with overdose (AOR 2.8, CI: 1.5-5.9). This study reveals a large, previously undocumented burden of non-fatal overdose among people who inject drugs in Malaysia and highlights the need for interventions that might reduce the risk of overdose, such as continuous opioid substitution therapy, provision of naloxone to prevent fatal overdose, treatment of polysubstance use, and working with police to improve the risk environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Geographical disparities in HIV prevalence and care among men who have sex with men in Malawi: results from a multisite cross-sectional survey.

PubMed

Wirtz, Andrea L; Trapence, Gift; Kamba, Dunker; Gama, Victor; Chalera, Rodney; Jumbe, Vincent; Kumwenda, Rosemary; Mangochi, Marriam; Helleringer, Stephane; Beyrer, Chris; Baral, Stefan

2017-06-01

Epidemiological assessment of geographical heterogeneity of HIV among men who have sex with men (MSM) is necessary to inform HIV prevention and care strategies in the more generalised HIV epidemics across sub-Saharan Africa, including Malawi. We aimed to measure the HIV prevalence, risks, and access to HIV care among MSM across multiple localities to better inform HIV programming for MSM in Malawi. Between Aug 1, 2011, and Sept 13, 2014, we recruited MSM into cross-sectional research via respondent-driven sampling (RDS) in seven districts of Malawi. RDS and site weights were used to estimate national HIV prevalence and engagement in care and in multilevel regression models to identify correlates of prevalent HIV infection. The comparative prevalence ratio of HIV among MSM relative to adult men was calculated by use of direct age-stratification. 2453 MSM were enrolled with a population HIV prevalence of 18·2% (95% CI 15·5-21·2), as low as 4·1% (2·2-7·6) in Mzuzu and as high as 24·5% (19·5-30·3) in Mulanje. The comparative HIV prevalence ratio was 2·52 when comparing MSM with the adult male population. Age-stratified HIV prevalence showed early onset of infection with 11·8% (95% CI 7·3-18·4) of MSM aged 18-19 years HIV infected. Factors positively associated with HIV infection included being aged 21-30 years and reporting female or transgender identity. Among HIV infected MSM, less than 1% reported ever being diagnosed with HIV infection (0·9%, 95% CI 0·4-2·5) and initiated antiretroviral treatment (0·2%, 0·2-0·3). HIV disproportionately affects MSM in Malawi with disparities sustained across the HIV care continuum. These issues are geographically heterogeneous and begin among young MSM, supporting geographically focused and age-specific approaches to confidential HIV testing with linkage to HIV services. Malawi Department of Nutrition, HIV and AIDS (DNHA), UNDP, UNFPA, UNAIDS, and UNICEF. Copyright © 2017 Elsevier Ltd. All rights reserved.

High prevalence of non-fatal overdose among people who inject drugs in Malaysia: Correlates of overdose and implications for overdose prevention from a cross-sectional study

PubMed Central

Bazazi, Alexander R.; Zelenev, Alexei; Fu, Jeannia J.; Yee, Ilias; Kamarulzaman, Adeeba; Altice, Frederick L.

2014-01-01

Background Overdose is the leading cause of death among opioid users, but no data are available on overdose among people who inject drugs in Malaysia. We present the first estimates of the prevalence and correlates of recent non-fatal overdose among people who inject drugs in Malaysia. Methods In 2010, 460 people who inject drugs were recruited using respondent-driven sampling (RDS) in Klang Valley to assess health outcomes associated with injection drug use. Self-reported history of non-fatal overdose in the previous 6 months was the primary outcome. Sociodemographic, behavioral and structural correlates of non-fatal overdose were assessed using multivariable logistic regression. Results All 460 participants used opioids and nearly all (99.1%) met criteria for opioid dependence. Most injected daily (91.3%) and were male (96.3%) and ethnically Malay (90.4%). Overall, 20% of participants had overdosed in the prior 6 months, and 43.3% had ever overdosed. The RDS-adjusted estimate of the 6-month period prevalence of overdose was 12.3% (95% confidence interval [CI] 7.9–16.6%). Having injected for more years was associated with lower odds of overdose (adjusted odds ratio [AOR] 0.6 per 5 years of injection, CI 0.5–0.7). Rushing an injection from fear of the police nearly doubled the odds of overdose (AOR 1.9, CI 1.9–3.6). Alcohol use was associated with recent non-fatal overdose (AOR 2.1, CI 1.1–4.2), as was methamphetamine use (AOR 2.3, CI 1.3–4.6). When adjusting for past-month drug use, intermittent but not daily methadone use was associated with overdose (AOR 2.8, CI 1.5–5.9). Conclusion This study reveals a large, previously undocumented burden of non-fatal overdose among people who inject drugs in Malaysia and highlights the need for interventions that might reduce the risk of overdose, such as continuous opioid substitution therapy, provision of naloxone to prevent fatal overdose, treatment of polysubstance use, and working with police to improve the risk environment. PMID:25532449

Cognition and Literacy in English Language Learners at Risk for Reading Disabilities

ERIC Educational Resources Information Center

Swanson, H. Lee; Orosco, Michael J.; Lussier, Cathy M.

2012-01-01

This study explores the cognitive basis of reading disabilities (RDs) in Spanish-speaking children who are learning English as a second language. Children (N = 393) designated as English language learners (ELLs) or bilingual with and without RDs in Grades 1, 2, and 3 were administered a battery of cognitive (short-term memory, working memory,…

Nonalgebraic integrability of one reversible dynamical system of the Cremona type

NASA Astrophysics Data System (ADS)

Rerikh, K. V.

1998-05-01

A reversible dynamical system (RDS) and a system of nonlinear functional equations, defined by a certain rational quadratic Cremona mapping and arising from the static model of the dispersion approach in the theory of strong interactions [the Chew-Low-type equations with crossing-symmetry matrix A(l,1)], are considered. This RDS is split into one- and two-dimensional ones. An explicit Cremona transformation that completely determines the exact solution of the two-dimensional system is found. This solution depends on an odd function satisfying a nonlinear autonomous three-point functional equation. Nonalgebraic integrability of RDS under consideration is proved using the method of Poincaré normal forms and the Siegel theorem on biholomorphic linearization of a mapping at a nonresonant fixed point.

Reductions in primate abundance and diversity in a multiuse protected area: synergistic impacts of hunting and logging in a congo basin forest.

PubMed

Remis, Melissa J; Jost Robinson, Carolyn A

2012-07-01

This article explores spatial and temporal changes in diurnal primate abundance and behavior in response to hunting, logging, and conservation at the Dzanga Sangha Dense Forest Reserve (RDS), Central African Republic over time. We use a combination of line-transect surveys in 2002 and 2009 (N = 540 km) and ethnographic interviews (N = 210) to investigate changes in the status of cercopithecines and colobines at RDS, with additional comparisons to earlier work. This protected area was lightly logged in the 1970s and the park was gazetted in 1990, with multiple-use reserve sectors allocated. Since the park's inception, hunting and the trade of primates have increased, along with human migration, greater accessibility of arms, and reduction of preferred ungulate prey. Primates have declined in both the park and reserve sectors. Our data further suggest that at RDS hunting has had a greater impact on primate diversity and abundance than logging. We have identified changes in species-specific vulnerability to hunting over time, with Cercopithecus nictitans and Lophocebus albigena initially having appeared to be relatively resistant to hunting pressure in 2002. However, subsequently as gun hunting has increased at RDS, these species have become vulnerable. Although monkeys at RDS have been responding behaviorally to increased gun hunting, they are not able to keep pace with changing hunting practices. This study allows us to begin to understand synergistic impacts of hunting and logging, necessary if we are to recommend strategies to better secure the future of primates in multiuse protected areas. © 2012 Wiley Periodicals, Inc.

Photoreceptor Cells With Profound Structural Deficits Can Support Useful Vision in Mice

PubMed Central

Thompson, Stewart; Blodi, Frederick R.; Lee, Swan; Welder, Chris R.; Mullins, Robert F.; Tucker, Budd A.; Stasheff, Steven F.; Stone, Edwin M.

2014-01-01

Purpose. In animal models of degenerative photoreceptor disease, there has been some success in restoring photoreception by transplanting stem cell–derived photoreceptor cells into the subretinal space. However, only a small proportion of transplanted cells develop extended outer segments, considered critical for photoreceptor cell function. The purpose of this study was to determine whether photoreceptor cells that lack a fully formed outer segment could usefully contribute to vision. Methods. Retinal and visual function was tested in wild-type and Rds mice at 90 days of age (RdsP90). Photoreceptor cells of mice homozygous for the Rds mutation in peripherin 2 never develop a fully formed outer segment. The electroretinogram and multielectrode recording of retinal ganglion cells were used to test retinal responses to light. Three distinct visual behaviors were used to assess visual capabilities: the optokinetic tracking response, the discrimination-based visual water task, and a measure of the effect of vision on wheel running. Results. RdsP90 mice had reduced but measurable electroretinogram responses to light, and exhibited light-evoked responses in multiple types of retinal ganglion cells, the output neurons of the retina. In optokinetic and discrimination-based tests, acuity was measurable but reduced, most notably when contrast was decreased. The wheel running test showed that RdsP90 mice needed 3 log units brighter luminance than wild type to support useful vision (10 cd/m2). Conclusions. Photoreceptors that lack fully formed outer segments can support useful vision. This challenges the idea that normal cellular structure needs to be completely reproduced for transplanted cells to contribute to useful vision. PMID:24569582

Efficacy of surfactant at different gestational ages for infants with respiratory distress syndrome

PubMed Central

Wang, Li; Chen, Long; Li, Renjun; Zhao, Jinning; Wu, Xiushuang; Li, Xue; Shi, Yuan

2015-01-01

Since exogenous surfactant replacement therapy was first used to prevent respiratory distress syndrome (RDS), it has become the main method for treatment of RDS. However, in some infants, death is inevitable despite intensive care and surfactant replacement therapy, especially in near-term and term infants. The main purpose of this study was to compare the therapeutic effect of pulmonary surfactant for infants at different gestational ages and to investigate whether exogenous surfactant replacement therapy is effective for all newborns with RDS. Data on surfactant replacement therapy, including blood gas, oxygenation function parameters and therapy results, were collected from 135 infants who were diagnosed with RDS during three years at a tertiary neonatal intensive care unit. According to gestational age, the subjects were classified into three groups as follows: group 1: gestational age <35 weeks (n=54); group 2: 35 weeks ≤ gestational age <37 weeks (n=35); group 3: gestational age ≥37 weeks (n=46). Six hours after surfactant was given, there were significantly better blood gas results in group 1 and worse results in groups 2 and 3. Similar oxygenation function parameter results were observed in the three groups. In addition, there was a trend toward an increased rate of repeated surfactant administration with increasing gestational age. For near-term and term infants, the efficacy of surfactant therapy was not as good as it was for preterm infants. The causes of RDS in near-term and term infants might be different from those in preterm infants and should be studied further. PMID:26550326

Have we left some behind? Trends in socio-economic inequalities in breastfeeding initiation: a population-based epidemiological surveillance study.

PubMed

Nickel, Nathan C; Martens, Patricia J; Chateau, Dan; Brownell, Marni D; Sarkar, Joykrishna; Goh, Chun Yan; Burland, Elaine; Taylor, Carole; Katz, Alan

2014-07-31

Breastfeeding is associated with improved health. Surveillance data show that breastfeeding initiation rates have increased; however, limited work has examined trends in socio-economic inequalities in initiation. The study's research question was whether socio-economic inequalities in breastfeeding initiation have changed over the past 20 years. This population-based study is a project within PATHS Equity for Children. Analyses used hospital discharge data for Manitoba mother-infant dyads with live births, 1988-2011 (n=316,027). Income quintiles were created, each with ~20% of dyads. Three-year, overall and by-quintile breastfeeding initiation rates were estimated for Manitoba and two hospitals. Age-adjusted rates were estimated for Manitoba. Rates were modelled using generalized linear models. Three measures, rate ratios (RRs), rate differences (RDs) and concentration indices, assessed inequality at each time point. We also compared concentration indices with Gini coefficients to assess breastfeeding inequality vis-à-vis income inequality. Trend analyses tested for changes over time. Manitoba and Hospital A initiation rates increased; Hospital B rates did not change. Significant inequalities existed in nearly every period, across all three measures: RRs, RDs and concentration indices. RRs and concentration indices suggested little to no change in inequality from 1988 to 2011. RDs for Manitoba (comparing initiation in the highest to lowest income quintiles) did not change significantly over time. RDs decreased for Hospital A, suggesting decreasing socio-economic inequalities in breastfeeding; RDs increased for Hospital B. Income inequality increased significantly in Manitoba during the study period. Overall breastfeeding initiation rates can improve while inequality persists or worsens.

Labour room Continuous Positive Airway Pressure (LR CPAP) in preterm neonates <34 weeks: An Indian experience.

PubMed

Desai, Saumil Ashvinkumar; Tule, Pankaj; Nanavati, Ruchi Nimish

2017-01-01

Early continuous positive airway pressure (CPAP) has proven to be beneficial in reducing ventilator dependence and subsequent chronic lung disease in neonates suffering from Respiratory distress syndrome (RDS). However, the efficacy of initiating labour room (LR) CPAP has not been determined prospectively in resource limited settings like India. Hence the objective of the present study was to study the efficacy of LR CPAP in preterm neonates with RDS in resource limited Indian settings. This was a prospective observational study including preterm neonates (26-34 weeks with RDS) carried out over a period of 6 months (January to June 2016) when the CPAP was initiated in LR. The outcome was compared with a similar population during the corresponding period of the previous year when CPAP was initiated in NICU. The historical controls were retrieved from case records and matched for gestational age and birth weight with the study population. There was 36% absolute risk reduction in the need for surfactant and 56% for mechanical ventilation in the LR CPAP group respectively. LR CPAP reduces the need for mechanical ventilation and surfactant in preterm neonates with RDS in resource limited settings.

Factors associated with syphilis seroreactivity among polydrug users in Northeast Brazil: A cross-sectional study using Respondent Driven Sampling.

PubMed

Baptista, Cremildo João; Dourado, Ines; Brignol, Sandra; Andrade, Tarcísio de Matos; Bastos, Francisco Inácio

2017-01-01

The burden of sexually transmitted infections (STIs), such as syphilis, is higher in low-income countries, with serious consequences and profound impact on sexual and reproductive health and human immunodeficiency virus (HIV) spread. Syphilis prevalence tend to be higher among people who misuse drugs than in the general population. To assess syphilis and associated factors among polydrug users (PDU) in the city of Salvador, Northeast Brazil. A cross-sectional study was conducted in 10 Brazilian cities between September and November 2009 using Respondent Driven Sampling (RDS). Participants answered an Audio Computer-Assisted Self Interview (ACASI) and were rapid tested for HIV and syphilis. We performed multivariable regression models for correlates of syphilis on Stata 10.0. Estimates were weighted by the inverse size of the individual social network size and homophily. Mean age was 29.3 years (range: 18-62), 74.0% were males, and 89.8% were non-white. Syphilis prevalence was 16.6%. Females (adjwOR:2.14; 95%CI:1.09-4.20), individuals over 29 years old (adjwOR:4.44; 95%CI:2.41-8.19), those who exchanged sex for money or drugs (adjwOR:3.51; 95%CI:1.84-6.71), "No/low" self-perceived risk of HIV infection (adjwOR:5.13; 95%CI:1.36-19.37), and having nine or less years of education (adjwOR:2.92; 95%CI:1.08-7.88) were associated with syphilis. One of the most pressing needs for syphilis prevention/control is the availability of rapid point-of-care diagnostic tests and treatment. Interventions should be tailored to PDU needs and their multiple burdens as shown in the present study, that may contribute to future studies aiming to better understand the relationships between drug use and syphilis. Copyright © 2016 Elsevier B.V. All rights reserved.

An analysis of respondent-driven sampling with injecting drug users in a high HIV prevalent state of India.

PubMed

Phukan, Sanjib Kumar; Medhi, Gajendra Kumar; Mahanta, Jagadish; Adhikary, Rajatashuvra; Thongamba, Gay; Paranjape, Ramesh S; Akoijam, Brogen S

2017-07-03

Personal networks are significant social spaces to spread of HIV or other blood-borne infections among hard-to-reach population, viz., injecting drug users, female sex workers, etc. Sharing of infected needles or syringes among drug users is one of the major routes of HIV transmission in Manipur, a high HIV prevalence state in India. This study was carried out to describe the network characteristics and recruitment patterns of injecting drug users and to assess the association of personal network with injecting risky behaviors in Manipur. A total of 821 injecting drug users were recruited into the study using respondent-driven sampling (RDS) from Bishnupur and Churachandpur districts of Manipur; data on demographic characteristics, HIV risk behaviors, and network size were collected from them. Transition probability matrices and homophily indices were used to describe the network characteristics, and recruitment patterns of injecting drug users. Univariate and multivariate binary logistic regression models were performed to analyze the association between the personal networks and sharing of needles or syringes. The average network size was similar in both the districts. Recruitment analysis indicates injecting drug users were mostly engaged in mixed age group setting for injecting practice. Ever married and new injectors showed lack of in-group ties. Younger injecting drug users had mainly recruited older injecting drug users from their personal network. In logistic regression analysis, higher personal network was found to be significantly associated with increased likelihood of injecting risky behaviors. Because of mixed personal network of new injectors and higher network density associated with HIV exposure, older injecting drug users may act as a link for HIV transmission or other blood-borne infections to new injectors and also to their sexual partners. The information from this study may be useful to understanding the network pattern of injecting drug users for enriching the HIV prevention in this region.

Respondent-driven sampling on the Thailand-Cambodia border. I. Can malaria cases be contained in mobile migrant workers?

PubMed Central

2011-01-01

Background Reliable information on mobility patterns of migrants is a crucial part of the strategy to contain the spread of artemisinin-resistant malaria parasites in South-East Asia, and may also be helpful to efforts to address other public health problems for migrants and members of host communities. In order to limit the spread of malarial drug resistance, the malaria prevention and control programme will need to devise strategies to reach cross-border and mobile migrant populations. Methodology The Respondent-driven sampling (RDS) method was used to survey migrant workers from Cambodia and Myanmar, both registered and undocumented, in three Thai provinces on the Thailand-Cambodia border in close proximity to areas with documented artemisinin-resistant malaria parasites. 1,719 participants (828 Cambodian and 891 Myanmar migrants) were recruited. Subpopulations of migrant workers were analysed using the Thailand Ministry of Health classification based on length of residence in Thailand of greater than six months (long-term, or M1) or less than six months (short-term, or M2). Key information collected on the structured questionnaire included patterns of mobility and migration, demographic characteristics, treatment-seeking behaviours, and knowledge, perceptions, and practices about malaria. Results Workers from Cambodia came from provinces across Cambodia, and 22% of Cambodian M1 and 72% of Cambodian M2 migrants had been in Cambodia in the last three months. Less than 6% returned with a frequency of greater than once per month. Of migrants from Cambodia, 32% of M1 and 68% of M2 were planning to return, and named provinces across Cambodia as their likely next destinations. Most workers from Myanmar came from Mon state (86%), had never returned to Myanmar (85%), and only 4% stated plans to return. Conclusion Information on migratory patterns of migrants from Myanmar and Cambodia along the malaria endemic Thailand-Cambodian border within the artemisinin resistance containment zone will help target health interventions, including treatment follow-up and surveillance. PMID:21554744

Sex Differences in HIV Prevalence, Behavioral Risks and Prevention Needs Among Anglophone and Francophone Sub-Saharan African Migrants Living in Rabat, Morocco.

PubMed

Johnston, Lisa; Oumzil, Hicham; El Rhilani, Houssine; Latifi, Amina; Bennani, Aziza; Alami, Kamal

2016-04-01

Morocco has experienced a dramatic increase of migration from sub-Sahara Africa during the past decade. Recently included among the most vulnerable populations cited in the Morocco National Strategic Plans on HIV/TB for 2012-2016, sub-Saharan Africa migrants living in an irregular administrative situation participated in a survey to provide baseline data about their socio-demographic, sexual and HIV testing behaviors and HIV and syphilis prevalence. Two surveys using respondent driven sampling were conducted in 2013 among males and females, ≥18 years, originating from sub-Saharan African countries and living and/or working in an irregular administrative situation in Rabat and residing at least 3 months in Morocco. Analysis was conducted to evaluate differences between the two samples and between females and males within each sample using the successive sampling estimator in RDS Analyst. Roughly 3 % of francophone and anglophone migrants were infected with HIV, whereas a statistically significantly higher percentage of francophone (2.8 %), compared to anglophone (0.3 %), migrants were infected with syphilis. Females were found to have HIV infection rates three times higher and past year sexually transmitted infection signs and symptoms more than two times higher than their male counterparts. Female migrants also had statistically significantly higher percentages of ever testing for HIV and HIV testing and receiving results in the past year compared to males. We found distinct and important differences between migrants depending on whether they come from francophone versus anglophone countries and whether they were male or female. Future research should continue to explore these differences, while policies and programs should note these differences to best allocate resources in providing social and health services to these populations.

A Portable Regional Weather and Climate Downscaling System Using GEOS-5, LIS-6, WRF, and the NASA Workflow Tool

NASA Astrophysics Data System (ADS)

Kemp, E. M.; Putman, W. M.; Gurganus, J.; Burns, R. W.; Damon, M. R.; McConaughy, G. R.; Seablom, M. S.; Wojcik, G. S.

2009-12-01

We present a regional downscaling system (RDS) suitable for high-resolution weather and climate simulations in multiple supercomputing environments. The RDS is built on the NASA Workflow Tool, a software framework for configuring, running, and managing computer models on multiple platforms with a graphical user interface. The Workflow Tool is used to run the NASA Goddard Earth Observing System Model Version 5 (GEOS-5), a global atmospheric-ocean model for weather and climate simulations down to 1/4 degree resolution; the NASA Land Information System Version 6 (LIS-6), a land surface modeling system that can simulate soil temperature and moisture profiles; and the Weather Research and Forecasting (WRF) community model, a limited-area atmospheric model for weather and climate simulations down to 1-km resolution. The Workflow Tool allows users to customize model settings to user needs; saves and organizes simulation experiments; distributes model runs across different computer clusters (e.g., the DISCOVER cluster at Goddard Space Flight Center, the Cray CX-1 Desktop Supercomputer, etc.); and handles all file transfers and network communications (e.g., scp connections). Together, the RDS is intended to aid researchers by making simulations as easy as possible to generate on the computer resources available. Initial conditions for LIS-6 and GEOS-5 are provided by Modern Era Retrospective-Analysis for Research and Applications (MERRA) reanalysis data stored on DISCOVER. The LIS-6 is first run for 2-4 years forced by MERRA atmospheric analyses, generating initial conditions for the WRF soil physics. GEOS-5 is then initialized from MERRA data and run for the period of interest. Large-scale atmospheric data, sea-surface temperatures, and sea ice coverage from GEOS-5 are used as boundary conditions for WRF, which is run for the same period of interest. Multiply nested grids are used for both LIS-6 and WRF, with the innermost grid run at a resolution sufficient for typical local weather features (terrain, convection, etc.) All model runs, restarts, and file transfers are coordinated by the Workflow Tool. Two use cases are being pursued. First, the RDS generates regional climate simulations down to 4-km for the Chesapeake Bay region, with WRF output provided as input to more specialized models (e.g., ocean/lake, hydrological, marine biology, and air pollution). This will allow assessment of climate impact on local interests (e.g., changes in Bay water levels and temperatures, innundation, fish kills, etc.) Second, the RDS generates high-resolution hurricane simulations in the tropical North Atlantic. This use case will support Observing System Simulation Experiments (OSSEs) of dynamically-targeted lidar observations as part of the NASA Sensor Web Simulator project. Sample results will be presented at the AGU Fall Meeting.

Locally Based Research and Development Units as Knowledge Brokers and Change Facilitators in Health and Social Care of Older People in Sweden

ERIC Educational Resources Information Center

Nyström, Monica Elisabeth; Hansson, Johan; Garvare, Rickard; Andersson-Bäck, Monica

2015-01-01

This article investigates the role of locally based research and development units (R&Ds) focusing on health and social services. Nearly 300 local R&Ds are funded by the Swedish government with the intention to facilitate knowledge transfer and development of high quality and effective health and social care organisations. Based on…

Natural mentors, mental health, and substance use: Exploring pathways via coping and purpose.

PubMed

Hurd, Noelle M; Stoddard, Sarah A; Bauermeister, Jose A; Zimmerman, Marc A

2014-03-01

The current study tested whether relationships with natural mentors may have contributed to fewer internalizing symptoms and less substance use among emerging adults through improved perceptions of coping abilities and an increased sense of life purpose. In addition, the current study investigated whether natural mentor role (i.e., familial vs. nonfamilial mentor) and the amount of time spent together in shared activities influenced emerging adults' internalizing behaviors and substance use via coping and purpose. Participants in the current study included 3,334 emerging adults (mean age = 20.8, 48.6% female, 75.4% white) from diverse regions across the United States who participated in an online survey. Participants were recruited via an adapted Web version of Respondent-Driven Sampling (webRDS). Forty-two percent of participants reported a relationship with a natural mentor. Indirect relationships between natural mentor presence and emerging adults' mental health and substance use via coping and purpose were found. Additional analyses indicated that emerging adults may benefit more from relationships with nonfamilial natural mentors in comparison with familial natural mentors. Findings also suggested that the amount of time participants spent with their natural mentors in shared activities was related to participants' alcohol use. Implications of this study's findings and directions for future research are discussed.

Natural Mentors, Mental Health, and Substance Use: Exploring Pathways via Coping and Purpose

PubMed Central

Hurd, Noelle M; Stoddard, Sarah A; Bauermeister, Jose A; Zimmerman, Marc A

2014-01-01

In the current study, we tested whether relationships with natural mentors may have contributed to fewer internalizing symptoms and less substance use among emerging adults through improved perceptions of coping abilities and an increased sense of life purpose. In addition, we investigated whether natural mentor role (i.e., familial vs. non-familial mentor) and the amount of time spent together in shared activities influenced emerging adults’ internalizing behaviors and substance use via coping and purpose. Participants in the current study included 3,334 emerging adults (mean age = 20.8, 48.6% female, 75.4% White) from diverse regions across the U.S. who participated in an online survey. Participants were recruited via an adapted web-version of Respondent-Driven Sampling (webRDS). Forty-two percent of participants reported a relationship with a natural mentor. We found indirect relationships between natural mentor presence and emerging adults’ mental health and substance use via coping and purpose. Additional analyses indicated that emerging adults may benefit more from relationships with non-familial natural mentors in comparison to familial natural mentors. We also found that the amount of time participants spent with their natural mentors in shared activities was related to participants’ alcohol use. Implications of this study’s findings and directions for future research are discussed. PMID:24826935

The Silk Road Health Project: How Mobility and Migration Status Influence HIV Risks among Male Migrant Workers in Central Asia

PubMed Central

El-Bassel, Nabila; Gilbert, Louisa; Shaw, Stacey A.; Mergenova, Gaukhar; Terlikbayeva, Assel; Primbetova, Sholpan; Ma, Xin; Chang, Mingway; Ismayilova, Leyla; Hunt, Tim; West, Brooke; Wu, Elwin; Beyrer, Chris

2016-01-01

Objectives We examined whether mobility, migrant status, and risk environments are associated with sexually transmitted infections (STIs) and HIV risk behaviors (e.g. sex trading, multiple partners, and unprotected sex). Methods We used Respondent Driven Sampling (RDS) to recruit external male migrant market vendors from Kyrgyzstan, Uzbekistan, and Tajikistan as well internal migrant and non-migrant market vendors from Kazakhstan. We conducted multivariate logistic regressions to examine the effects of mobility combined with the interaction between mobility and migration status on STIs and sexual risk behaviors, when controlling for risk environment characteristics. Results Mobility was associated with increased risk for biologically-confirmed STIs, sex trading, and unprotected sex among non-migrants, but not among internal or external migrants. Condom use rates were low among all three groups, particularly external migrants. Risk environment factors of low-income status, debt, homelessness, and limited access to medical care were associated with unprotected sex among external migrants. Conclusion Study findings underscore the role mobility and risk environments play in shaping HIV/STI risks. They highlight the need to consider mobility in the context of migration status and other risk environment factors in developing effective prevention strategies for this population. PMID:26967159

South African Men Who Have Sex With Both Men and Women and How They Differ From Men Who Have Sex With Men Exclusively.

PubMed

Alcala-Alezones, Carolina; Sandfort, Theo G M; Serafino, Stephanie; Reddy, Vasu

2018-03-05

The label "men who have sex with men" (MSM) is used to categorize a diverse population exclusively on the basis of its sexual behavior. Understanding the diversity that this label comprises is critical for the development of health interventions that effectively reach the various populations subsumed under this label. In this cross-sectional study of South African MSM (N = 480) recruited through respondent-driven sampling (RDS), we explored differences between men who had sex with both men and women (MSMW) and men who had sex with men exclusively (MSME). We found significant differences between these two groups in terms of sexual attraction, sexual identity, sexual preferences, sexual histories, and current sexual practices. MSMW were more likely to be confused about their same-sex attraction, to experience internalized homophobia, and to have paid for sex in the previous year, while MSME were more gender nonconforming and more likely to have been forced to have sex in the previous year. These findings underscore that the MSM label comprises a diverse population and that exclusive sexual engagement with other men is a critical distinction to take into account in understanding this diversity and fully grasping the lived experiences of men who have sex with men.

Predictors of consistent condom use based on the Information-Motivation-Behavioral Skills (IMB) model among female sex workers in Jinan, China

PubMed Central

2011-01-01

Background Female commercial sex workers (FSWs) are at high risk of human immunodeficiency virus (HIV) transmission in China. This study was designed to examine the predictors of condom use with clients during vaginal intercourse among FSWs based on the Information-Motivation-Behavioral Skills (IMB) model and to describe the relationships between IMB model constructs. Methods A cross-sectional study was conducted in Jinan of Shandong Province, from May to October, 2009. Participants (N = 432) were recruited using Respondent-Driven Sampling (RDS). A self-administered questionnaire was used to collect data. Structural equation modeling was used to assess the IMB model. Results A total of 427 (98.8%) participants completed their questionnaires. Condom use was significantly predicted by social referents support, experiences with and attitudes toward condoms, self-efficacy, and health behaviors and condom use skills. Significant indirect predictors of condom use mediated through behavioral skills included HIV knowledge, social referents support, and substance use. Conclusions These results suggest that the IMB model could be used to predict condom use among Chinese FSWs. Further research is warranted to develop preventive interventions on the basis of the IMB model to promote condom use among FSWs in China. PMID:21329512

Development of a Reference Data Set (RDS) for dental age estimation (DAE) and testing of this with a separate Validation Set (VS) in a southern Chinese population.

PubMed

Jayaraman, Jayakumar; Wong, Hai Ming; King, Nigel M; Roberts, Graham J

2016-10-01

Many countries have recently experienced a rapid increase in the demand for forensic age estimates of unaccompanied minors. Hong Kong is a major tourist and business center where there has been an increase in the number of people intercepted with false travel documents. An accurate estimation of age is only possible when a dataset for age estimation that has been derived from the corresponding ethnic population. Thus, the aim of this study was to develop and validate a Reference Data Set (RDS) for dental age estimation for southern Chinese. A total of 2306 subjects were selected from the patient archives of a large dental hospital and the chronological age for each subject was recorded. This age was assigned to each specific stage of dental development for each tooth to create a RDS. To validate this RDS, a further 484 subjects were randomly chosen from the patient archives and their dental age was assessed based on the scores from the RDS. Dental age was estimated using meta-analysis command corresponding to random effects statistical model. Chronological age (CA) and Dental Age (DA) were compared using the paired t-test. The overall difference between the chronological and dental age (CA-DA) was 0.05 years (2.6 weeks) for males and 0.03 years (1.6 weeks) for females. The paired t-test indicated that there was no statistically significant difference between the chronological and dental age (p > 0.05). The validated southern Chinese reference dataset based on dental maturation accurately estimated the chronological age. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

European Consensus Guidelines on the Management of Respiratory Distress Syndrome - 2016 Update.

PubMed

Sweet, David G; Carnielli, Virgilio; Greisen, Gorm; Hallman, Mikko; Ozek, Eren; Plavka, Richard; Saugstad, Ola Didrik; Simeoni, Umberto; Speer, Christian P; Vento, Máximo; Visser, Gerard H A; Halliday, Henry L

2017-01-01

Advances in the management of respiratory distress syndrome (RDS) ensure that clinicians must continue to revise current practice. We report the third update of the European Guidelines for the Management of RDS by a European panel of expert neonatologists including input from an expert perinatal obstetrician based on available literature up to the beginning of 2016. Optimizing the outcome for babies with RDS includes consideration of when to use antenatal steroids, and good obstetric practice includes methods of predicting the risk of preterm delivery and also consideration of whether transfer to a perinatal centre is necessary and safe. Methods for optimal delivery room management have become more evidence based, and protocols for lung protection, including initiation of continuous positive airway pressure and titration of oxygen, should be implemented from soon after birth. Surfactant replacement therapy is a crucial part of the management of RDS, and newer protocols for surfactant administration are aimed at avoiding exposure to mechanical ventilation, and there is more evidence of differences among various surfactants in clinical use. Newer methods of maintaining babies on non-invasive respiratory support have been developed and offer potential for greater comfort and less chronic lung disease. As technology for delivering mechanical ventilation improves, the risk of causing lung injury should decrease although minimizing the time spent on mechanical ventilation using caffeine and if necessary postnatal steroids are also important considerations. Protocols for optimizing the general care of infants with RDS are also essential with good temperature control, careful fluid and nutritional management, maintenance of perfusion and judicious use of antibiotics all being important determinants of best outcome. © 2016 S. Karger AG, Basel.

Hall effects on the Walén relation in rotational discontinuities and Alfvén waves

NASA Astrophysics Data System (ADS)

Wu, B. H.; Lee, L. C.

2000-08-01

For Alfvénic fluctuations in magnetohydrodynamics (MHD) the perturbed transverse velocity Vt and magnetic field Bt can be related by the Walén relation, Vt = ±Bt/(μ0ρ)1/2 ≡;±VAt, where ρ is the plasma density, VAt is the transverse Alfvén velocity, and the plus (minus) sign is for antiparallel (parallel) propagation. However, observations of Vt and Bt for Alfvén waves and rotational discontinuities in the solar wind and at the magnetopause showed an obvious deviation from the relation. In this paper, modifications of the Walén relation for linear and nonlinear Alfvén waves and rotational discontinuities (RDs) are examined in the Hall-MHD formulation. Let Vit (≈ Vt) be the transverse ion velocity and Vet be the transverse electron velocity. It is found that Vit = ±Bt(z)/(μ0ρ1)1/2 = ±(ρ(z)/ρ1)1/2 VAt(z) and Vet = ±(ρ1/μ0)1/2Bt(z)/ρ(z) = ±(ρ1/ρ(z))1/2 VAt(z)for RDs in Hall-MHD, where ρ1 is the upstream plasma density. The ion and electron Walén ratios are defined as Ai = Vit/VAt and Ae = Vet/VAt, respectively. It is found in Hall-MHD that ?, AiAe = 1 and Ai < 1 (Ai > 1) for Alfvén waves and RDs with right-hand (left-hand) polarization. The Hall dispersive effect may modify the ion Walén ratio by ΔAi≈±0.14 for the magnetopause RDs and by ΔAi≈±0.07 for the interplanetary RDs.

Analysis and comparison of the effects of N-BiPAP and Bubble-CPAP in treatment of preterm newborns with the weight of below 1500 grams affiliated with respiratory distress syndrome: A randomised clinical trial.

PubMed

Sadeghnia, Alireza; Barekateyn, Behzad; Badiei, Zohre; Hosseini, Seyyed Mohsen

2016-01-01

Nowadays, establishment of nCPAP and surfactant administration is considered to be the first level of intervention for newborns engaged in the process of Respiratory Distress Syndrome (RDS). In order to decrease the side effects of the nCPAP management placed in noninvasive-non-cycled respiratory support. Noninvasive-cycled respiratory support mechanism have been developed such as N-BiPAP. Therefore, we compared N-BiPAP with Bubble-CPAP in a clinical trial. This research was done as an on newborns weighing less than 1500 grams affiliated with RDS. A3 The total number of newborns was 70. Newborns were divided into two groups with the sample size of 35 patients in each, according to odd and even document numbers. One group was treated with N-BiPAP and the other with Bubble-CPAP. Patients were compared according to the length of treatment with noninvasive respiratory support, length of oxygen intake, number of surfactant doses administered, need for invasive mechanical ventilation, apnea, patent ductus arteriosus (PDA), chronic lung disease, intraventricular hemorrhage, pneumothorax, and death. Data was recorded and compared. The average duration for noninvasive respiratory support and the average time of need to complementary oxygen was not significantly different in both groups (P value > 0.05). Need for invasive ventilation, also chronic lung disease, intraventricular hemorrhage (IVH), pneumothorax, need for the next dose of surfactant, and the death rate did also have no meaningful difference. (P value > 0.05). In this research N-BiPAP did not show any obvious clinical preference over the Bubble-CPAP in treatment of newborns weighing less than 1500 grams and affiliated with RDS.

Implicit and explicit self-esteem in remitted depressed patients.

PubMed

Smeijers, Danique; Vrijsen, Janna N; van Oostrom, Iris; Isaac, Linda; Speckens, Anne; Becker, Eni S; Rinck, Mike

2017-03-01

Low self-esteem is a symptom of depression and depression vulnerability. Prior research on self-esteem has largely focused on implicit (ISE) and explicit self-esteem (ESE) as two separate constructs, missing their interaction. Therefore, the current study investigated the interaction between ISE and ESE in a depression-vulnerable group (remitted depressed patients; RDs), compared to never-depressed controls (ND). Seventy-five RDs and 75 NDs participated in the study. To measure ESE, the Rosenberg Self-Esteem Scale (RSES) was used. The Implicit Association Test (IAT) and the Name Letter Preference Task (NLPT) were used to assess ISE. RDs reported lower ESE than NDs. However, the two groups did not differ on ISE. RDs exhibited a damaged self-esteem or a low-congruent self-esteem, similar to what has been found in currently depressed patients. Moreover, damaged self-esteem was associated with residual depressive symptoms. The results need to be interpreted with care because the IAT and NLPT did not reveal the same associations with the clinical measures. Implicit and explicit self-esteem may be different constructs in depression and studying the combination is important. The present study provides evidence indicating that damaged self-esteem may be more detrimental than low congruent self-esteem. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios.

PubMed

Zhao, Bo; Liu, An; Wu, Guangxue; Li, Dunzhu; Guan, Yuntao

2017-01-01

Road-deposited sediments (RDS) on urban impervious surfaces are important carriers of heavy metals. Dissolved heavy metals that come from RDS influenced by acid rain, are more harmful to urban receiving water than particulate parts. RDS and its associated heavy metals were investigated at typical functional areas, including industrial, commercial and residential sites, in Guangdong, Southern China, which was an acid rain sensitive area. Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios. Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above 3.0, regardless of land use. Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types. Coarse particles (>150μm) that could be efficiently removed by conventional street sweepers, accounted for 55.1%-47.1% of the total dissolved metal loading in runoff with pH3.0-5.6. The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain. Copyright © 2016. Published by Elsevier B.V.

Composition and structure of tuber cell walls affect in vitro digestibility of potato (Solanum tuberosum L.).

PubMed

Frost, Jovyn K T; Flanagan, Bernadine M; Brummell, David A; O'Donoghue, Erin M; Mishra, Suman; Gidley, Michael J; Monro, John A

2016-10-12

The digestibility of starchy foods, such as potatoes, can be characterized by the proportion of starch that is rapidly digestible by in vitro hydrolysis (rapidly digestible starch, RDS). This study evaluated the RDS content in a potato germplasm collection consisting of 98 genotypes and identified three advanced lines, Crop39, Crop71 and Crop85, where cooked potato RDS content was significantly lower than that of their respective isolated starches (P < 0.05). In Crop39, Crop71 and Crop85, the properties of their isolated starch did not differ significantly from that of five control lines with higher RDS contents. Cell wall analyses revealed that, compared with other lines tested, Crop39, Crop71 and Crop85 had at least four times the amount of rhamnogalacturonan-I (RG-I) galactan side-chains that were very firmly attached to the wall and requiring 4 M KOH for extraction. Pectin solubilization during cooking was also remarkably low (2-4%) in these three lines compared with other lines tested (7-19%). The findings suggest that possession of higher amounts of RG-I galactan that interact strongly with cellulose may provide a sturdier wall that better resists solubilization during cooking, and effectively impedes access of digestive enzymes for starch hydrolysis in an in vitro model.

Management matters.

PubMed

Gould, Rebecca A; Canter, Deborah

2008-11-01

Fewer than 50% of registered dietitians (RDs) supervise personnel and 76% have no budget authority. Because higher salaries are tied to increasing levels of authority and responsibility, RDs must seek management and leadership roles to enjoy the increased remuneration tied to such positions. Advanced-level practice in any area of dietetics demands powerful communication abilities, proficiency in budgeting and finance, comfort with technology, higher-order decision-making/problem-solving skills, and well-honed human resource management capabilities, all foundational to competent management practice. As RDs envision the future of the dietetics profession, practitioners must evaluate management competence in both hard and soft skills. Just as research is needed to support evidenced-based clinical practice, the same is needed to support management practice across the profession. Dietetics educators and preceptors should be as enthusiastic about management practice as they are clinical practice when educating and mentoring future professionals. Such encouragement and support can mean that new RDs and dietetic technicians, registered, will understand what it takes to advance to higher levels of responsibility, authority, and subsequent enhanced remuneration. In the ever-changing social, legal, ethical, political, economic, technological, and ecological environments of work, food and nutrition professionals who are willing to step forward and assume the risks and responsibilities of management also will share in the rewards, and propel the profession to new heights of recognition and respect.

Assessment of three dead detector correction methods for cone-beam computed tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelms, David W.; Shukla, Hemant I.; Nixon, Earl

Purpose: Dead detectors due to manufacturing defects or radiation damage in the electronic portal imaging devices (EPIDs) used for cone-beam computed tomography (CBCT) can lead to image degradation and ring artifacts. In this work three dead detector correction methods were assessed using megavoltage CBCT (MVCBCT) as a test system, with the goals of assessing the relative effectiveness of the three methods and establishing the conditions for which they fail. Methods: MVCBCT projections acquired with four linacs at 8 and 60 MU (monitor units) were degraded with varying percentages (2%-95%) of randomly distributed dead single detectors (RDSs), randomly distributed dead detectormore » clusters (RDCs) of 2 mm diameter, and nonrandomly distributed dead detector disks (NRDDs) of varying diameter (4-16 mm). Correction algorithms were bidirectional linear interpolation (BLI), quad-directional linear interpolation (QLI), and a Laplacian solution (LS) method. Correction method failure was defined to occur if ring artifacts were present in the reconstructed phantom images from any linac or if the modulation transfer function (MTF) for any linac dropped below baseline with a p value, calculated with the two sample t test, of less than 0.01. Results: All correction methods failed at the same or lower RDC/RDS percentages and NRDD diameters for the 60 MU as for the 8 MU cases. The LS method tended to outperform or match the BLI and QLI methods. If ring artifacts anywhere in the images were considered unacceptable, the LS method failed for 60 MU at >33% RDS, >2% RDC, and >4 mm NRDD. If ring artifacts within 4 mm longitudinally of the phantom section interfaces were considered acceptable, the LS method failed for 60 MU at >90% RDS, >80% RDC, and >4 mm NRDD. LS failed due to MTF drop for 60 MU at >50% RDS, >25% RDC, and >4 mm NRDD. Conclusions: The LS method is superior to the BLI and QLI methods, and correction algorithm effectiveness decreases as imaging dose increases. All correction methods failed first due to ring artifacts and second due to MTF drop. If ring artifacts in axial slices within a 4 mm longitudinal distance from phantom section interfaces are acceptable, statistically significant loss in spatial resolution does not occur until over 25% of the EPID is covered in randomly distributed dead detectors, or NRDDs of 4 mm diameter are present.« less

RDS-SL VS Communication System

DOE Office of Scientific and Technical Information (OSTI.GOV)

2012-09-12

The RDS-SL VS Communication System is a component of the Radiation Detection System for Strategic, Low-Volume Seaports. Its purpose is to acquire real-time data from radiation portal monitors and cameras, record that data in a database, and make it available to system operators and administrators via a web interface. The software system contains two components: a standalone data acquisition and storage component and an ASP.NETweb application that implements the web interface.

Augmentation of machine structure to improve its diagnosability

NASA Technical Reports Server (NTRS)

Hsieh, L.

1973-01-01

Two methods of augmenting the structure of a sequential machine so that it is diagnosable are presented. The checkable (checking sequences) and repeated symbol distinguishing sequences (RDS) are discussed. It was found that as few as twice the number of outputs of the given machine is sufficient for constructing a state-output augmentation with RDS. Techniques for minimizing the number of states in resolving convergences and in resolving equivalent and nonreduced cycles are developed.

ON INTERMITTENT TURBULENCE HEATING OF THE SOLAR WIND: DIFFERENCES BETWEEN TANGENTIAL AND ROTATIONAL DISCONTINUITIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Xin; Tu Chuanyi; He Jiansen

The intermittent structures in solar wind turbulence, studied by using measurements from the WIND spacecraft, are identified as being mostly rotational discontinuities (RDs) and rarely tangential discontinuities (TDs) based on the technique described by Smith. Only TD-associated current sheets (TCSs) are found to be accompanied with strong local heating of the solar wind plasma. Statistical results show that the TCSs have a distinct tendency to be associated with local enhancements of the proton temperature, density, and plasma beta, and a local decrease of magnetic field magnitude. Conversely, for RDs, our statistical results do not reveal convincing heating effects. These resultsmore » confirm the notion that dissipation of solar wind turbulence can take place in intermittent or locally isolated small-scale regions which correspond to TCSs. The possibility of heating associated with RDs is discussed.« less

Neonatal hypoxic risk in preterm birth infants: the influence of sex and severity of respiratory distress on cognitive recovery.

PubMed

Lauterbach, M D; Raz, S; Sander, C J

2001-07-01

The authors examined the differential effects of neonatal respiratory distress syndrome (RDS)--a condition associated with elevated risk for neonatal hypoxia-ischemia--on the cognitive development of the two sexes. The authors also attempted to establish whether the severity of respiratory distress is linked to cognitive outcome. Findings revealed an appreciable female advantage in cognitive recovery from RDS, yet the association between severity of RDS and outcome did not reach conventional statistical significance level. The sex effect on intelligence test performance was significantly greater for nonverbal subtests than for verbal ones. These results augment earlier findings of sex differences in cognitive recovery from perinatal intracranial hemorrhage. The current investigation also extends these results to a population of children at neonatal hypoxic risk for whom early brain injury was excluded on the basis of neonatal cranial ultrasound findings.

Rheumatologic services in Central Asian countries: current state of development of rheumatology in Central Asia.

PubMed

Omurzakova, Nazgul A; Yamano, Yoshihisa; Saatova, Guli M; Shukurova, Surayo M; Mirzakhanova, Mavliuda I; Kydyralieva, Ryskul B; Jumagulova, Aynagul S; Mirrakhimov, Erkin M; Seisenbaev, Askar Sh; Nishioka, Kusuki; Nakajima, Toshihiro

2009-12-01

Rheumatologic and public health services of Central Asia's republics have suffered hugely as a result of social and economic declines following the dissolution of the Union of Soviet Socialist Republics (USSR) and transition of these republics to market economies. Between 1990 and 2000 there was a mass outflow of highly skilled rheumatologists and teachers and researchers in rheumatology to countries abroad, leading to significant deprivation of rheumatological service in Central Asian countries. During this time, there was continued growth of various rheumatic diseases (RDs) including rheumatic fever, and musculoskeletal and connective tissue disorders. The medical and social burden of RDs imposed on society was strongly underestimated until recent times. There is an urgent need to define the epidemiology of RDs and their impact on the quality of life of people afflicted by these conditions, and to improve the diagnostics and treatment of these conditions.

Approaches to Recruiting ‘Hard-To-Reach’ Populations into Re­search: A Review of the Literature

PubMed Central

Shaghaghi, Abdolreza; Bhopal, Raj S; Sheikh, Aziz

2011-01-01

Background: ‘Hard-to-reach’ is a term used to describe those sub-groups of the population that may be difficult to reach or involve in research or public health programmes. Application of a single term to call these sub-sections of populations implies a homogeneity within distinct groups, which does not necessarily exist. Different sampling techniques were introduced so far to recruit hard-to-reach populations. In this article, we have reviewed a range of ap­proaches that have been used to widen participation in studies. Methods: We performed a Pubmed and Google search for relevant English language articles using the keywords and phrases: (hard-to-reach AND population* OR sampl*), (hidden AND population* OR sample*) and (“hard to reach” AND population* OR sample*) and a consul­tation of the retrieved articles’ bibliographies to extract empirical evidence from publications that discussed or examined the use of sampling techniques to recruit hidden or hard-to-reach populations in health studies. Results: Reviewing the literature has identified a range of techniques to recruit hard-to-reach populations, including snowball sampling, respondent-driven sampling (RDS), indigenous field worker sampling (IFWS), facility-based sampling (FBS), targeted sampling (TS), time-location (space) sampling (TLS), conventional cluster sampling (CCS) and capture re-capture sampling (CR). Conclusion: The degree of compliance with a study by a certain ‘hard-to-reach’ group de­pends on the characteristics of that group, recruitment technique used and the subject of inter­est. Irrespective of potential advantages or limitations of the recruitment techniques reviewed, their successful use depends mainly upon our knowledge about specific characteristics of the target populations. Thus in line with attempts to expand the current boundaries of our know­ledge about recruitment techniques in health studies and their applications in varying situa­tions, we should also focus on possibly all contributing factors which may have an impact on participation rate within a defined population group. PMID:24688904

HIV seroprevalence and high-risk sexual behavior among female sex workers in Central Brazil.

PubMed

Fernandes, Fernanda R P; Mousquer, Gina J; Castro, Lisie S; Puga, Marco A; Tanaka, Tayana S O; Rezende, Grazielli R; Pinto, Clarice S; Bandeira, Larissa M; Martins, Regina M B; Francisco, Roberta B L; Teles, Sheila A; Motta-Castro, Ana R C

2014-01-01

Female sex workers (FSWs) are considered a high-risk group for human immunodeficiency virus (HIV) infection due to their social vulnerability and factors associated with their work. We estimated the prevalence of HIV, and identified viral subtypes and risk factors among FSWs. A cross-sectional study using respondent-driven sampling (RDS) method was conducted among 402 FSWs in Campo Grande city, Brazil, from 2009 to 2011. Participants were interviewed using a standardized questionnaire about sociodemograpic characteristics and risk behavior. Blood samples were collected for serological testing of HIV. Of the 402 FSWs, median age and age of initiating sex work were 25 years (Interquartile range [IQR]: 9) and 20 years (IQR: 6), respectively. The majority reported use of alcohol (88.5%), had 5-9 years (median: 9; IQR: 3) of schooling (54.5%), 68.6% had tattoos/body piercings, and 45.1% had more than seven clients per week (median: 7; IQR: 10). Only 32.9% of FSW reported using a condom with nonpaying partners in the last sexual contact. Prevalence of HIV infection was 1.0% (95% CI: 0.1-2.6%). Genotyping for HIV-1 performed on three samples detected subtypes B, C, and F1. Sex work in the Midwestern region of Brazil is characterized by reduced education, large numbers of clients per week, and inconsistent condom use, mainly with nonpaying partners. Although prevalence of HIV infection is currently low, elevated levels of high-risk sexual behavior confirm a need to implement prevention measures. Specific interventions targeting FSWs must emphasize the risk associated with both clients and nonpaying partners while providing knowledge about HIV prevention.

Antenatal Corticosteroids for the Prevention of Respiratory Distress Syndrome in Premature Twins.

PubMed

Viteri, Oscar A; Blackwell, Sean C; Chauhan, Suneet P; Refuerzo, Jerrie S; Pedroza, Claudia; Salazar, Ximena C; Sibai, Baha M

2016-09-01

To estimate whether antenatal corticosteroids before 34 weeks of gestation are associated with reduced incidence of respiratory distress syndrome (RDS) and composite neonatal morbidity in preterm twins. This was a secondary analysis of a multicenter randomized trial for the prevention of preterm birth in multiple gestations. All liveborn, nonanomalous twins delivered between 24 0/7 and 36 6/7 weeks of gestation were included. Neonatal outcomes were compared between women who received antenatal corticosteroids and those who did not. The primary outcome was the incidence of RDS. The secondary outcome was the incidence of serious composite neonatal morbidity. Multivariable log Poisson regression with correlation adjustment between twins born to the same mother was performed for confounder control. Adjusted relative risks (RRs) are reported for study outcomes. Based on a post hoc power analysis, this study was powered to detect an RR less than 0.63 for RDS and greater than 1.43 for composite neonatal morbidity outcomes. A total of 432 women (850 neonates) were included. Only 300 (35%) neonates were born to women receiving antenatal corticosteroids. After multivariable regression, antenatal corticosteroids were not associated with a reduced incidence of RDS (81 [27%] compared with 92 [17%] neonates, adjusted RR 1.28, 95% confidence interval [CI] 0.97-1.71) or composite neonatal morbidity (87 [29%] compared with 108 [20%] neonates, adjusted RR 1.21, 95% CI 0.93-1.56). However, antenatal corticosteroids were associated with increased rates of neonatal intensive care unit admissions (235 [78%] compared with 322 [59%] neonates, adjusted RR 1.22, 95% CI 1.09-1.36) and mechanical ventilation (70 [23%] compared with 66 [12%] neonates, adjusted RR 1.52, 95% CI 1.12-2.09). Focusing analysis to newborns delivered before 34 weeks of gestation (n=311), 161 (52%) received antenatal corticosteroids. Similarly, no differences in the rate of RDS (66 [41%] compared with 68 [45%] neonates, adjusted RR 1.01, 95% CI 0.76-1.34) or composite neonatal morbidity (72 [45%] compared with 81 [54%] neonates, adjusted RR 0.95, 95% CI 0.74-1.22) were noted. In this cohort of preterm twins, antenatal corticosteroid administration was not associated with a reduced incidence of RDS and composite neonatal morbidity.

Respiratory morbidity in twins by birth order, gestational age and mode of delivery.

PubMed

Bricelj, Katja; Tul, Natasa; Lasic, Mateja; Bregar, Andreja Trojner; Verdenik, Ivan; Lucovnik, Miha; Blickstein, Isaac

2016-10-01

To evaluate the relationship between respiratory morbidity in twins by gestational age, birth order and mode of delivery. All twin deliveries at <37 weeks, registered in a national database, in the period 2003-2012 were classified into four gestational age groups: 33-36, 30-32, 28-29, and <28 weeks. Outcome variables included transient tachypnea of the newborn (TTN), respiratory distress syndrome (RDS) and need for assisted ventilation. A total of 1836 twins were born vaginally, and 2142 twins were born by cesarean delivery, for a grand total of 3978 twins. TTN did not appear to be related to birth order and to the mode of delivery. In contrast, RDS was more frequent among the second born twins in the vaginal birth groups born at 30-36 weeks [odds ratio (OR) 2.5, 95% confidence interval (CI) 1.2-5.1 and OR 2.0, 95% CI 1.2-3.5 for 33-36 weeks and 30-32 weeks, respectively], whereas this trend was seen in the cesarean birth groups born earlier (OR 3.8, 95% CI 1.1-13.0 for 28-29 weeks). Cesarean delivery significantly increased the frequency of RDS in twin A as well as in twin B compared with vaginal birth, but only at gestational ages <30 weeks. Mode of delivery and birth order have a gestational age dependent effect on the incidence of RDS.

Health professionals' knowledge and understanding about Listeria monocytogenes indicates a need for improved professional training.

PubMed

Buffer, Janet L; Medeiros, Lydia C; Kendall, Patricia; Schroeder, Mary; Sofos, John

2012-07-01

Listeria monocytogenes causes listeriosis, an uncommon but potentially fatal disease in immunocompromised persons, with a public health burden of approximately $2 billion annually. Those consumers most at risk are the highly susceptible populations otherwise known as the immunocompromised. Health professionals have a considerable amount of interaction with the immunocompromised and are therefore a valuable resource for providing appropriate safe food handling information. To determine how knowledgeable health professionals are about Listeria monocytogenes, a nationwide Web-based survey was distributed targeting registered nurses (RNs) and registered dietitians (RDs) who work with highly susceptible populations. Responses were received from 499 health professionals. Knowledge and understanding of Listeria monocytogenes was assessed descriptively. Parametric and nonparametric analyses were used to detect differences between RNs and RDs. The major finding is that there are gaps in knowledge and a self-declared lack of understanding by both groups, but especially RNs, about Listeria monocytogenes. RDs were more likely than RNs to provide information about specific foods and food storage behaviors to prevent a Listeria infection. Notably, neither group of health professionals consistently provided Listeria prevention messages to their immunocompromised patients. Pathogens will continue to emerge as food production, climate, water, and waste management systems change. Health professionals, represented by RNs and RDs, need resources and training to ensure that they are providing the most progressive information about various harmful pathogens; in this instance, Listeria monocytogenes.

Factors Associated with the Intention of Registered Dietitians to Discuss Nutrigenetics with their Patients/Clients.

PubMed

Bouchard-Mercier, Annie; Desroches, Sophie; Robitaille, Julie; Vohl, Marie-Claude

2016-12-01

The objective of this study was to investigate factors affecting the intention of Registered Dietitians (RDs) to discuss nutrigenetics with their patients/clients. A survey based on the theory of planned behaviour (TPB; attitude, subjective norm, and perceived behavioural control) was developed and sent by email to RD members of the Ordre professionnel des diététistes du Québec. Multiple regression analyses were performed to examine the determinants of intention and behaviour. A total of 141 RDs completed the questionnaire (5.8% response rate). On a scale from -2 to 2 (from strongly disagree to strongly agree), the intention of discussing nutrigenetics with patients/clients was neutral (mean of -0.07 ± 0.92). The TPB construct of attitude was the most strongly associated with intention (β = 0.66, P < 0.0001) followed by perceived behavioural control (β = 0.33, P < 0.0001) and subjective norm (β = 0.21, P = 0.03). Finally, 13 out of 141 RDs (~9%) actually practiced the behaviour, which was to have discussed nutrigenetics with their patients/clients in the last 3 months. Only perceived behavioural control contributed to explain the behaviour (β = 0.17, P < 0.0001). Main determinants of the intention of RDs to discuss nutrigenetics with their patients/clients were determined. This knowledge will help inform the design of future educational content about nutrigenetics.

Management matters.

PubMed

Gould, Rebecca A; Canter, Deborah

2012-05-01

Fewer than 50% of registered dietitians (RDs) supervise personnel and 76% have no budget authority. Because higher salaries are tied to increasing levels of authority and responsibility, RDs must seek management and leadership roles to enjoy the increased remuneration tied to such positions. Advanced-level practice in any area of dietetics demands powerful communication abilities, proficiency in budgeting and finance, comfort with technology, higher-order decision-making/problem-solving skills, and well-honed human resource management capabilities, all foundational to competent management practice. As RDs envision the future of the dietetics profession, practitioners must evaluate management competence in both hard and soft skills. Just as research is needed to support evidenced-based clinical practice, the same is needed to support management practice across the profession. Dietetics educators and preceptors should be as enthusiastic about management practice as they are clinical practice when educating and mentoring future professionals. Such encouragement and support can mean that new RDs and dietetic technicians, registered, will understand what it takes to advance to higher levels of responsibility, authority, and subsequent enhanced remuneration. In the ever-changing social, legal, ethical, political, economic, technological, and ecological environments of work, food and nutrition professionals who are willing to step forward and assume the risks and responsibilities of management also will share in the rewards, and propel the profession to new heights of recognition and respect. Copyright © 2012. Published by Elsevier Inc.

[Optic density of gastric content in the rapid assessment of pulmonary maturity of the newborn].

PubMed

Brandell, L; Sepúlveda, W H; Araneda, H; Mangiamarchi, M

1991-01-01

The authors studied the correlation between optical density at 650 nm (OD650) in paired samples of amniotic fluid and newborn gastric aspirate obtained from 50 pregnant women who underwent cesarean delivery and from their respective newborns. There was a good correlation between both samples (r = 0.92), which demonstrates that OD650 is a reliable method for studying neonatal pulmonary maturity, especially in those high-risk cases in which no prenatal study is available. None of the infants with mature readings (OD650 > or = 0.10) and 6 out of 13 infants with immature readings (OD650 < 0.10) developed RDS.

Gender-based wage differentials among registered dietitians.

PubMed

Pollard, Prudence; Taylor, Maxine; Daher, Noha

2007-01-01

The debate on compensation equity is broad-based, addressing many organizational, personal, and outcome factors. Central to compensation philosophy is the issue of gender equity. Health care, like many other industries, remains fraught with gender inequity in compensation. This inequity is partially explained by choice of practice area. However, much remains unexplained. Health care is a female-dominated industry with most of the women working in the allied health professions (eg, nurses, dietitians, etc). Registered dietitians (RD) may experience wage discrimination, similar to registered nurses, but prior to the present study, the assumption was not tested. Using data from the first comprehensive study of RD compensation, we examined gender equity in total cash compensation to RDs. Data were collected on total cash compensation, and questions focused on career progression and work outcomes. For purposes of our study, we analyzed data on 5,477 full-time RDs. Ninety-six percent were women, the median age was 43, and median total cash compensation for RDs employed in the position for at least 1 year was $45,500.00. Women earned $45,285.00 and men earned $50,250.00. A median wage gap of $4,965.00 between women and men was observed. Variability in total cash compensation to women was best explained by size of budget, years of experience, work setting, and educational level. Variability for men was explained by size of budget, years of experience, educational level, and employer status. Conclusions suggest that given the wage discrimination that female RDs experience, work organizations should evaluate their pay plans to monitor pay equity. Factors that women can manage to receive compensation that is equal to that of the men include size of budgets they manage, years of experience in the field, employer status, work setting, and educational level attained. Findings are useful for career advisers, human resource specialists, compensation specialists, supervisors, RDs, and compensation researchers.

The economics of treatment for infants with respiratory distress syndrome.

PubMed

Neil, N; Sullivan, S D; Lessler, D S

1998-01-01

To define clinical outcomes and prevailing patterns of care for the initial hospitalization of infants at greatest risk for respiratory distress syndrome (RDS); to estimate direct medical care costs associated with the initial hospitalization; and to introduce and demonstrate a simulation technique for the economic evaluation of health care technologies. Clinical outcomes and usual-care algorithms were determined for infants with RDS in three birthweight categories (500-1,000g; >1,000-1,500g; and >1,500g) using literature- and expert-panel-based data. The experts were practitioners from major U.S. hospitals who were directly involved in the clinical care of such infants. Using the framework derived from the usual care patterns and outcomes, the authors developed an itemized "micro-costing" economic model to simulate the costs associated with the initial hospitalization of a hypothetical RDS patient. The model is computerized and dynamic; unit costs, frequencies, number of days, probabilities and population multipliers are all variable and can be modified on the basis of new information or local conditions. Aggregated unit costs are used to estimate the expected medical costs of treatment per patient. Expected costs of initial hospitalization per uncomplicated surviving infant with RDS were estimated to be $101,867 for 500-1,000g infants; $64,524 for >1,000-1,500g infants; and $27,224 for >1,500g infants. Incremental costs of complications among survivors were estimated to be $22,155 (500-1,000g); $11,041 (>1,000-1,500g); and $2,448 (>1,500 g). Expected costs of initial hospitalization per case (including non-survivors) were $100,603; $72,353; and $28,756, respectively. An itemized model such as the one developed here serves as a benchmark for the economic assessment of treatment costs and utilization. Moreover, it offers a powerful tool for the prospective evaluation of new technologies or procedures designed to reduce the incidence of, severity of, and/or total hospital resource use ascribed to RDS.

The potential of planets orbiting red dwarf stars to support oxygenic photosynthesis and complex life

NASA Astrophysics Data System (ADS)

Gale, Joseph; Wandel, Amri

2017-01-01

We review the latest findings on extra-solar planets and their potential of having environmental conditions that could support Earth-like life. Focusing on planets orbiting red dwarf (RD) stars, the most abundant stellar type in the Milky Way, we show that including RDs as potential life supporting host stars could increase the probability of finding biotic planets by a factor of up to a thousand, and reduce the estimate of the distance to our nearest biotic neighbour by up to 10. We argue that binary and multiple star systems need to be taken into account when discussing habitability and the abundance of biotic exoplanets, in particular RDs in such systems. Early considerations indicated that conditions on RD planets would be inimical to life, as their habitable zones would be so close to the host star as to make planets tidally locked. This was thought to cause an erratic climate and expose life forms to flares of ionizing radiation. Recent calculations show that these negative factors are less severe than originally thought. It has also been argued that the lesser photon energy of the radiation of the relatively cool RDs would not suffice for oxygenic photosynthesis (OP) and other related energy expending reactions. Numerous authors suggest that OP on RD planets may evolve to utilize photons in the infrared. We however argue, by analogy to the evolution of OP and the environmental physiology and distribution of land-based vegetation on Earth, that the evolutionary pressure to utilize infrared radiation would be small. This is because vegetation on RD planets could enjoy continuous illumination of moderate intensity, containing a significant component of photosynthetic 400-700 nm radiation. We conclude that conditions for OP could exist on RD planets and consequently the evolution of complex life might be possible. Furthermore, the huge number and the long lifetime of RDs make it more likely to find planets with photosynthesis and life around RDs than around Solar type stars.

False-Positive Error Rates for Reliable Digit Span and Auditory Verbal Learning Test Performance Validity Measures in Amnestic Mild Cognitive Impairment and Early Alzheimer Disease.

PubMed

Loring, David W; Goldstein, Felicia C; Chen, Chuqing; Drane, Daniel L; Lah, James J; Zhao, Liping; Larrabee, Glenn J

2016-06-01

The objective is to examine failure on three embedded performance validity tests [Reliable Digit Span (RDS), Auditory Verbal Learning Test (AVLT) logistic regression, and AVLT recognition memory] in early Alzheimer disease (AD; n = 178), amnestic mild cognitive impairment (MCI; n = 365), and cognitively intact age-matched controls (n = 206). Neuropsychological tests scores were obtained from subjects participating in the Alzheimer's Disease Neuroimaging Initiative (ADNI). RDS failure using a ≤7 RDS threshold was 60/178 (34%) for early AD, 52/365 (14%) for MCI, and 17/206 (8%) for controls. A ≤6 RDS criterion reduced this rate to 24/178 (13%) for early AD, 15/365 (4%) for MCI, and 7/206 (3%) for controls. AVLT logistic regression probability of ≥.76 yielded unacceptably high false-positive rates in both clinical groups [early AD = 149/178 (79%); MCI = 159/365 (44%)] but not cognitively intact controls (13/206, 6%). AVLT recognition criterion of ≤9/15 classified 125/178 (70%) of early AD, 155/365 (42%) of MCI, and 18/206 (9%) of control scores as invalid, which decreased to 66/178 (37%) for early AD, 46/365 (13%) for MCI, and 10/206 (5%) for controls when applying a ≤5/15 criterion. Despite high false-positive rates across individual measures and thresholds, combining RDS ≤ 6 and AVLT recognition ≤9/15 classified only 9/178 (5%) of early AD and 4/365 (1%) of MCI patients as invalid performers. Embedded validity cutoffs derived from mixed clinical groups produce unacceptably high false-positive rates in MCI and early AD. Combining embedded PVT indicators lowers the false-positive rate. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Gender Differences in Factors Related to HIV Risk Behaviors among People Who Inject Drugs in North-East India

PubMed Central

McFall, Allison M.; Solomon, Sunil S.; Srikrishnan, Aylur K.; Vasudevan, Canjeevaram K.; Anand, Santhanam; Celentano, David D.; Mehta, Shruti H.; Kumar, Suresh; Lucas, Gregory M.

2017-01-01

People who inject drugs (PWID) in India are at high risk for HIV, with women being at elevated risk. Using a socio-ecological framework, this study assessed whether factors associated with HIV transmission risk behaviors differed across men and women PWID. Data for this cross-sectional study were collected from 6449 PWID in 7 cities in Northeast India. Men (n = 5653) and women (n = 796) PWID were recruited using respondent-driven sampling (RDS). We assessed sex differences in two recent HIV transmission risk behaviors: multiple sex partners and needle/syringe sharing. We used multi-level logistic regression models, which incorporated sampling weights and random intercepts for city, to assess factors associated with these HIV risks, separately among men and women. The prevalence of HIV was significantly higher among women than men (53% vs 18.4%, p<0.01). Nearly 13% of men and 8% of women (p = .30) had multiple partners. Employment in men and relationship status and stigma in women were significantly associated with multiple partners. Approximately 25% of men and 19% of women engaged in needle sharing (p = .16). Younger age in women and depression symptoms in men were significantly associated with increased risk for sharing needles. We found that sexual and drug related risk behaviors were common among PWID in Northeast India, and there were differences between men and women in the socio-ecologic correlates of these behaviors. Contextually-integrated and gender-specific HIV prevention and intervention efforts are needed that consider factors at individual, interpersonal- and community-levels that uniquely impact HIV risks among PWID. PMID:28099458

Social Capital and Vulnerable Urban Youth in Five Global Cities

PubMed Central

Marshall, Beth Dail; Astone, Nan; Blum, Robert; Jejeebhoy, Shireen; Delany-Moretlwe, Sinead; Brahmbhatt, Heena; Olumide, Adesola; Wang, Ziliang

2015-01-01

Background Social capital is essential for the successful development of young people. The current study examines direct measures of social capital in young people in five urban global contexts. Methods The Well Being of Adolescents in Vulnerable Environments (WAVE) is a global study of young people aged 15 to 19 years living in disadvantaged, urban settings. Respondent Driven Sampling (RDS) was used to recruit approximately 500 participants from each site. The sample included 2339 young people (mean age 16.7 years; 47.5% female). We examined the associations between social capital in four domains -family, school, peers and neighborhood -and demographic characteristics using gender stratified Ordinary Least Squares regression. We also examined associations between self-reported health and the four social capital domains is minimal. School enrollment was positively associated with social capital for young women in Baltimore, Delhi, and Shanghai: the association was less consistent for young men. The same pattern is true for perceived wealth. Unstable housing was associated with low familial social capital in all groups except young women in Shanghai and young men in Ibadan and Johannesburg. Being raised outside a two-parent family has a widespread, negative association with social capital. Self-reported health had a mainly positive association with social capital with the most consistent association being neighborhood social capital, Conclusions Different types of social capital interact with social contexts and gender differently. Strategies that aim to build social capital as part of risk reduction and positive youth development programming need to recognize that social capital enhancement may work differently for different groups and in different settings. PMID:25453999

Risk Factors for Domestic Child Sex Trafficking in the United States.

PubMed

Fedina, Lisa; Williamson, Celia; Perdue, Tasha

2016-07-01

Despite increased effort to respond to human trafficking at national and state levels, very little empirical research has been conducted on domestic child sex trafficking. This study retrospectively examines associations between multiple risk factors and domestic child sex trafficking (i.e., entry into the commercial sex industry under the age of 18) in a sample of individuals aged 16 and older currently involved in the commercial sex industry ( N = 273). Two primary research questions are addressed: (1) What set of risk factors, prior to entering the commercial sex industry, are associated with domestic child sex trafficking and (2) what group differences, if any, exist in risk factors between current or former domestic child sex-trafficking victims and non-trafficked adults engaged in the commercial sex industry? A cross-sectional survey was administered using Respondent-Driven Sampling (RDS) in five cities in one Midwestern state. Overall, 115 participants (48.3%) were identified as current or former domestic child sex-trafficking victims. Bivariate results suggest that childhood emotional and sexual abuse, rape, ever running away from home, having family members in sex work, and having friends who purchased sex were significantly associated with domestic child sex trafficking. Multivariate results indicate that domestic child sex trafficking victims were significantly more likely to have ever run away and to be a racial/ethnic minority than non-trafficked adults engaged in the commercial sex industry. Findings can inform state-level policies on human trafficking and assist child protection and juvenile justice agencies in developing prevention and intervention responses to commercial sexual exploitation.

Size Effects in Linear Elastic Fracture Mechanics

DTIC Science & Technology

1988-01-01

Fracture, Brighton, U.K., (1969) 119-130. 65 D. H. Winne and B. M. Wundt , "Application of the Griffith-Irwin Theory of Crack Propagation to the Bursting...1.10 d 1.0 1.00 d 2.0 0.82 b-d Winne and Wundt [65], 1.32 1.52 0.88 b-d Ni-Mo-V, RDS 4.56 0.64 b Ni-Mo-V (0.27 Mo), RDS 1.32 4.56 0.71 d 2.66 0.81 d Cr

Manipulating the Rate-Limiting Step in Water Oxidation Catalysis by Ruthenium Bipyridine–Dicarboxylate Complexes

DOE PAGES

Shaffer, David W.; Xie, Yan; Szalda, David J.; ...

2016-11-01

In order to gain a deeper mechanistic understanding of water oxidation by [(bda)Ru(L) 2] catalysts (bdaH 2 = [2,2'-bipyridine]-6,6'-dicarboxylic acid; L = pyridine-type ligand), a series of modified catalysts with one and two trifluoromethyl groups in the 4 position of the bda 2– ligand was synthesized and studied using stopped-flow kinetics. The additional $-$CF 3 groups increased the oxidation potentials for the catalysts and enhanced the rate of electrocatalytic water oxidation at low pH. Stopped-flow measurements of cerium(IV)-driven water oxidation at pH 1 revealed two distinct kinetic regimes depending on catalyst concentration. At relatively high catalyst concentration (ca. ≥10 –4more » M), the rate-determining step (RDS) was a proton-coupled oxidation of the catalyst by cerium(IV) with direct kinetic isotope effects (KIE > 1). At low catalyst concentration (ca. ≤10 –6 M), the RDS was a bimolecular step with k H/k D ≈ 0.8. The results support a catalytic mechanism involving coupling of two catalyst molecules. The rate constants for both RDSs were determined for all six catalysts studied. The presence of $-$CF 3 groups had inverse effects on the two steps, with the oxidation step being fastest for the unsubstituted complexes and the bimolecular step being faster for the most electron-deficient complexes. Finally, though the axial ligands studied here did not significantly affect the oxidation potentials of the catalysts, the nature of the ligand was found to be important not only in the bimolecular step but also in facilitating electron transfer from the metal center to the sacrificial oxidant.« less

Comparison of the hepatic and thyroid gland effects of sodium phenobarbital in wild type and constitutive androstane receptor (CAR) knockout rats and pregnenolone-16α-carbonitrile in wild type and pregnane X receptor (PXR) knockout rats.

PubMed

Haines, Corinne; Chatham, Lynsey R; Vardy, Audrey; Elcombe, Clifford R; Foster, John R; Lake, Brian G

2018-05-01

A number of chemicals produce liver and thyroid gland tumours in rodents by nongenotoxic modes of action (MOAs). In this study the hepatic and thyroid gland effects of the constitutive androstane receptor (CAR) activator sodium phenobarbital (NaPB) were examined in male Sprague-Dawley wild type (WT) rats and in CAR knockout (CAR KO) rats and the effects of the pregnane X receptor (PXR) activator pregnenolone-16α-carbonitrile (PCN) were examined in WT and PXR knockout (PXR KO) rats. Rats were either fed diets containing 0 (control) or 500 ppm NaPB or were dosed with 0 (control) or 100 mg/kg/day PCN orally for 7 days. The treatment of WT rats with NaPB and PCN for 7 days resulted in increased relative liver weight, increased hepatocyte replicative DNA synthesis (RDS) and the induction of cytochrome P450 CYP2B and CYP3A subfamily enzyme, mRNA and protein levels. In marked contrast, the treatment of CAR KO rats with NaPB and PXR KO rats with PCN did not result in any increases in liver weight and induction of CYP2B and CYP3A enzymes. The treatment of CAR KO rats with NaPB had no effect on hepatocyte RDS, while PCN produced only a small increase in hepatocyte RDS in PXR KO rats. Treatment with NaPB had no effect on thyroid gland weight in WT and CAR KO rats, whereas treatment with PCN resulted in an increase in relative thyroid gland weight in WT, but not in PXR KO, rats. Thyroid gland follicular cell RDS was increased by the treatment of WT rats with NaPB and PCN, with NaPB also producing a small increase in thyroid gland follicular cell RDS in CAR KO rats. Overall, the present study with CAR KO rats demonstrates that a functional CAR is required for NaPB-mediated increases in liver weight, stimulation of hepatocyte RDS and induction of hepatic CYP enzymes. The studies with PXR KO rats demonstrate that a functional PXR is required for PCN-mediated increases in liver weight and induction of hepatic CYP enzymes; with induction of hepatocyte RDS also being largely mediated through PXR. The hepatic effects of NaPB in CAR KO rats and of PCN in PXR KO rats are in agreement with those observed in other recent literature studies. These results suggest that CAR KO and PXR KO rats are useful experimental models for liver MOA studies with rodent CAR and PXR activators and may also be useful for thyroid gland MOA studies. Copyright © 2018 Elsevier B.V. All rights reserved.

HIV prevalence and characteristics of sex work among female sex workers in Hargeisa, Somaliland, Somalia.

PubMed

Kriitmaa, Kelsi; Testa, Adrienne; Osman, Mohamed; Bozicevic, Ivana; Riedner, Gabriele; Malungu, Jacqueline; Irving, Greg; Abdalla, Ismail

2010-07-01

To measure prevalence of HIV and syphilis and describe characteristics of sex work among female sex workers (FSWs) in Hargeisa, Somaliland, Somalia. A cross-sectional survey recruited 237 FSWs using respondent-driven sampling (RDS). A face-to-face, structured interview using handheld-assisted personal interviewing (HAPI) on personal digital assistants (PDAs) was completed and blood collected for serological testing. FSWs 15-19 years old accounted for 6.9% of the population; 20-24 year-old constituted an additional 18.0%. The majority (86.6%) never attended school. International (59.0%) and interzonal (10.7%) migration was common. Most (95.7%) reported no other source of income; 13.8% had five or more clients in the last 7 days. A minority (38.4%) had heard of STIs, even fewer (6.9%) held no misconceptions about HIV. Only 24% of FSW reported using a condom at last transactional sex, and 4% reported ever been tested for HIV. HIV prevalence was 5.2% and syphilis prevalence was 3.1%. Sex work in Hargeisa, Somaliland, Somalia, is characterized by high numbers of sexual acts and extremely low knowledge of HIV. This study illustrates the need for targeted HIV prevention interventions focusing on HIV testing, risk-reduction awareness raising, and review of condom availability and distribution mechanisms among FSWs and males engaging with FSWs.

Magnetic field directional discontinuities - Characteristics between 0.46 and 1.0 AU

NASA Technical Reports Server (NTRS)

Lepping, R. P.; Behannon, K. W.

1986-01-01

Based on Mariner 10 data, a statistical survey and an application of the Sonnerup-Cahill variance procedure to a visual identification with 1.2-s averages for time intervals corresponding to the equally spaced heliocentric distances of 1.0, 0.72 and 0.46 AU, are employed to study the characteristics of directional discontinuities (DDs) in the interplanetary magnetic field. Analysis using two methods demonstrated that the ratio of tangential discontinuities (TDs) to rotational discontinuities (RDs) decreased with decreasing radial distance. Decreases in average discontinuity thickness of 41 percent between 1.0 and 0.72 AU, and 56 percent between 1.0 and 0.46 AU, were found for both TDs and RDs, in agreement with Pioneer 10 data between 1 and 5 AU. Normalization of the individual DD thicknesses with respect to the estimated local proton gyroradius (R sub L) gave a nearly constant average thickness at the three locations, 36 + or - 5 R sub L, for both RDs and TDs.

Promoting positive human development and social justice: Integrating theory, research and application in contemporary developmental science.

PubMed

Lerner, Richard M

2015-06-01

The bold claim that developmental science can contribute to both enhancing positive development among diverse individuals across the life span and promoting social justice in their communities, nations and regions is supported by decades of theoretical, methodological and research contributions. To explain the basis of this claim, I describe the relational developmental systems (RDS) metamodel that frames contemporary developmental science, and I present an example of a programme of research within the adolescent portion of the life span that is associated with this metamodel and is pertinent to promoting positive human development. I then discuss methodological issues associated with using RDS-based models as frames for research and application. Finally, I explain how the theoretical and methodological ideas associated with RDS thinking may provide the scholarly tools needed by developmental scientists seeking to contribute to human thriving and to advance social justice in the Global South. © 2015 International Union of Psychological Science.

Inflammation-induced preterm lung maturation: lessons from animal experimentation.

PubMed

Moss, Timothy J M; Westover, Alana J

2017-06-01

Intrauterine inflammation, or chorioamnionitis, is a major contributor to preterm birth. Prematurity per se is associated with considerable morbidity and mortality resulting from lung immaturity but exposure to chorioamnionitis reduces the risk of neonatal respiratory distress syndrome (RDS) in preterm infants. Animal experiments have identified that an increase in pulmonary surfactant production by the preterm lungs likely underlies this decreased risk of RDS in infants exposed to chorioamnionitis. Further animal experimentation has shown that infectious or inflammatory agents in amniotic fluid exert their effects on lung development by direct effects within the developing respiratory tract, and probably not by systemic pathways. Differences in the effects of intrauterine inflammation and glucocorticoids demonstrate that canonical glucocorticoid-mediated lung maturation is not responsible for inflammation-induced changes in lung development. Animal experimentation is identifying alternative lung maturational pathways, and transgenic animals and cell culture techniques will allow identification of novel mechanisms of lung maturation that may lead to new treatments for the prevention of RDS. Copyright © 2016. Published by Elsevier Ltd.

Factors affecting responses of infants with respiratory distress syndrome to exogenous surfactant therapy.

PubMed

Ho, N K

1993-02-01

Approximately 20% to 30% of infants with respiratory distress syndrome (RDS) do not respond to surfactant replacement therapy. Unfortunately there is no uniform definition of 'response' or 'non-response' to surfactant therapy. Response was based on improvement in a/A PO2 and/or mean airway pressure (MAP) by some and on improvement in FIO2 and/or MAP by others. Even the point of time at which evaluation of response was done is different in various reports. There is an urgent need to adopt an uniform definition. Most premature babies are surfactant deficient which is the aetiological factor of RDS. Generally good antenatal care and perinatal management are essential in avoidance of premature birth. Babies with lung hypoplasia and who are extremely premature (less than 24 weeks of gestation) do not respond well to exogenous surfactant replacement because of structural immaturity. Prompt management of asphyxiated birth and shock are necessary as there may be negative response to surfactant replacement. Foetal exposure to glucocorticoids improves responsiveness to postnatal administration of surfactant. Antenatal steroid therapy has become an important part of management of RDS with surfactant replacement. The premature lungs with high alveolar permeability tend to develop pulmonary oedema. With the presence of plasma-derived surfactant inhibitors, the response to exogenous surfactant may be affected. These inhibitors may also be released following ventilator barotrauma. The standard of neonatal intensive care such as ventilatory techniques has an important bearing on the outcome of the RDS babies.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of residents' willingness to pay to reduce air pollution to improve children's health in community and hospital settings in Shanghai, China.

PubMed

Wang, Keran; Wu, Jinyi; Wang, Rui; Yang, Yingying; Chen, Renjie; Maddock, Jay E; Lu, Yuanan

2015-11-15

Shanghai, along with many major cities in China, faces deterioration of air quality and increases in air pollution-related respiratory diseases (RDs) in children due to rapid industrialization and urbanization. The Contingent Valuation Method (CVM) was used to qualitatively and quantitatively measure the willingness to pay (WTP) for reducing children's RDs through air quality improvement. Between April and May, 2014, 975 face-to-face interviews were collected from parents in a community-based and a hospital-setting in Shanghai. Multiple imputation and the Probit model were used to determine the relationship between the WTP and the related environmental factors, child health factors and the socio-economic status. Most respondents reported being willing to make a financial contribution to improve air quality in both the community (52.6%) and hospital (70.2%) samples. Those in the hospital setting were willing to pay significantly more ¥504 (USD$80.7) compared to the community sample ¥428 ($68.5) as expected. Reasons for those not being willing to pay included lack of disposable income and believing that responsibility of the air quality was a community issue. These did not differ by sample. Annual household income and education were related to WTP. This study indicated that parents in Shanghai would be willing to pay for improved air quality. Children's health can be the incentive for the citizens' participation and support in the air quality improvement, therefore, hospital settings may present unique places to improve education about air quality and enhance advocacy efforts. This study also suggested that future environmental policies be addressed more rigorously for targeted populations. Copyright © 2015 Elsevier B.V. All rights reserved.

Survey of United States Army Reserve (USAR) Troop Program Unit (TPU) soldiers 1989. Tabulation of Questionnaire Responses: Longitudinal Sample: Junior Enlisted Stayers from 1988 to 1989. 1989 Questionnaire Responses

DTIC Science & Technology

1989-09-30

AD-A237 531 1989 SURVEY OF UNITED STATES ARMY RESERVE (USAR) TROOP PROGRAM UNIT (TPU) SOLDIERS Tabulation of Questionnaire Responses: Longitudinal...Program Unit (TPU) Soldiers . The Tabulation Volumes list questionnaire items and the percent of respondents (weighted to population estimates) who have...Reserve population eligible for selection was defined by the number of personnel rec,,rds on a Dpeber 1988 SIDPERS data base; this totalled 280,265

Risk Behaviors, Prevalence of HIV and Hepatitis C Virus Infection and Population Size of Current Injection Drug Users in a China-Myanmar Border City: Results from a Respondent-Driven Sampling Survey in 2012

PubMed Central

Li, Lei; Assanangkornchai, Sawitri; Duo, Lin; McNeil, Edward; Li, Jianhua

2014-01-01

Background Injection drug use has been the major cause of HIV/AIDS in China in the past two decades. We measured the prevalences of HIV and hepatitis C virus (HCV) prevalence and their associated risk factors among current injection drug users (IDUs) in Ruili city, a border region connecting China with Myanmar that has been undergoing serious drug use and HIV spread problems. An estimate of the number of current IDUs is also presented. Methods In 2012, Chinese IDUs who had injected within the past six months and aged ≥18 years were recruited using a respondent-driven sampling (RDS) technique. Participants underwent interviews and serological testing for HIV, HBV, HCV and syphilis. Logistic regression indentified factors associated with HIV and HCV infections. Multiplier method was used to obtain an estimate of the size of the current IDU population via combining available service data and findings from our survey. Results Among 370 IDUs recruited, the prevalence of HIV and HCV was 18.3% and 41.5%, respectively. 27.1% of participants had shared a needle/syringe in their lifetime. Consistent condom use rates were low among both regular (6.8%) and non-regular (30.4%) partners. Factors independently associated with being HIV positive included HCV infection, having a longer history of injection drug use and experience of needle/syringe sharing. Participants with HCV infection were more likely to be HIV positive, have injected more types of drugs, have shared other injection equipments and have unprotected sex with regular sex partners. The estimated number of current IDUs in Ruili city was 2,714 (95% CI: 1,617–5,846). Conclusions IDUs may continue to be a critical subpopulation for transmission of HIV and other infections in this region because of the increasing population and persistent high risk of injection and sexual behaviours. Developing innovative strategies that can improve accessibility of current harm reduction services and incorporate more comprehensive contents is urgently needed. PMID:25203256

Repeat surfactant therapy for postsurfactant slump.

PubMed

Katz, L A; Klein, J M

2006-07-01

To evaluate repeat surfactant therapy for the treatment of respiratory failure associated with postsurfactant slump in extremely low birth weight infants (ELBW) by characterizing the population of premature infants who develop postsurfactant slump and measuring their response to a secondary course of surfactant therapy. A retrospective analysis of a cohort of all patients admitted over a 3-year period with birth weights <1000 g (ELBW infants). Information was collected by chart review and the patients were categorized into three distinct groups for analysis. Initial surfactant only, patients who received surfactant replacement therapy only for respiratory distress syndrome (RDS); repeat surfactant, patients who received both initial surfactant replacement for RDS and repeat surfactant therapy for postsurfactant slump (defined as respiratory failure after 6 days of age), and no surfactant, patients in whom no surfactant was ever administered. A respiratory severity score (RSS) was used to measure the severity of lung disease and response to surfactant therapy. Over 3 years, there were 165 ELBW infants who could develop postsurfactant slump and be eligible for repeat surfactant therapy. There were 39 infants who never received any surfactant therapy estimated gestational age (EGA) 27.7 +/- 1.7, birth weight 856 +/- 109 g) either at birth or after 6 days of life. There were 126 patients treated for RDS with initial surfactant replacement therapy (EGA 25.6 +/- 1.9 weeks, birth weight 713 +/- 179 g). Out of these RDS patients, 101 improved with an initial course of surfactant therapy (EGA 26 +/- 1.8, birth weight 751 +/- 143 g), but 25 (20% of the patients with RDS) developed postsurfactant slump and received a repeat course of surfactant therapy (EGA 24.7 +/- 1.2, birth weight 647 +/- 120 g). The repeat surfactant group (postsurfactant slump) was significantly more premature and had significantly lower birth weights compared to both the initial surfactant only group and the no surfactant ever group. Logistic regression analysis revealed that lack of antenatal steroids, earlier gestational age, and the receiving of 2 or more doses of surfactant to treat the initial RDS were significantly associated with receiving repeat surfactant therapy for postsurfactant slump. Of the 25 patients treated with a repeat course of surfactant therapy more than 70% of patients (n = 18) had an improvement in their lung disease with a 15% reduction in their RSS. This improvement was significant at all time points evaluated (12, 24, and 48 h). We found that a repeat course of surfactant therapy, after day of life 6, led to a significant improvement in hypoxemic respiratory failure in premature infants with postsurfactant slump. Infants who received repeat surfactant therapy were born at a significantly earlier gestational age, had significantly smaller birth weight and had significantly worse lung disease. They were significantly less likely to have received antenatal steroids and were significantly more likely to have received multiple doses of surfactant to treat their initial RDS. A repeat course of surfactant therapy for patients with postsurfactant slump appeared beneficial in the short-term. These initial findings would support performing randomized control trials of repeat surfactant therapy for postsurfactant slump.

The abundance of biotic exoplanets and life on planets of Red Dwarf stars

NASA Astrophysics Data System (ADS)

Wandel, Amri; Gale, Joseph

2016-07-01

The Kepler mission has shown that Earthlike planets orbiting within the Habitable Zones of their host stars are common. We derive an expression for the abundance of life bearing (biotic) extra-solar-system planets (exoplanets) in terms of the (yet unknown) probability for the evolution of biotic life. This "biotic probability" may be estimated by future missions and observations, e.g. spectral analyses of the atmospheres of exoplanets, looking for biomarkers. We show that a biotic probability in the range 0.001-1 implies that a biotic planet may be expected within ~10-100 light years from Earth. Of particular interest in the search for exolife are planets orbiting Red Dwarf (RD) stars, the most frequent stellar type. Previous researches suggested that conditions on planets near RDs would be inimical to life, e.g. the Habitable Zone of RDs is small, so their habitable planets would be close enough to be tidally locked. Recent calculations show that this and other properties of RDs, presumed hostile for the evolution of life, are less severe than originally estimated. We conclude that RD planets could be hospitable for the evolution of life as we know it, not less so than planets of solar-type stars. This result, together with the large number of RDs and their Kepler planet-statistics, makes finding life on RD planets ~10-1000 times more likely than on planets of solar-type stars. Our nearest biotic RD-planet is likely to be 2-10 times closer than the nearest solar-type one.

Impact of hypothermia on implementation of CPAP for neonatal respiratory distress syndrome in a low-resource setting.

PubMed

Carns, Jennifer; Kawaza, Kondwani; Quinn, M K; Miao, Yinsen; Guerra, Rudy; Molyneux, Elizabeth; Oden, Maria; Richards-Kortum, Rebecca

2018-01-01

Neonatal hypothermia is widely associated with increased risks of morbidity and mortality, but remains a pervasive global problem. No studies have examined the impact of hypothermia on outcomes for preterm infants treated with CPAP for respiratory distress syndrome (RDS). This retrospective analysis assessed the impact of hypothermia on outcomes of 65 neonates diagnosed with RDS and treated with either nasal oxygen (N = 17) or CPAP (N = 48) in a low-resource setting. A classification tree approach was used to develop a model predicting survival for subjects diagnosed with RDS. Survival to discharge was accurately predicted based on three variables: mean temperature, treatment modality, and mean respiratory rate. None of the 23 neonates with a mean temperature during treatment below 35.8°C survived to discharge, regardless of treatment modality. Among neonates with a mean temperature exceeding 35.8°C, the survival rate was 100% for the 31 neonates treated with CPAP and 36.4% for the 11 neonates treated with nasal oxygen (p<0.001). For neonates treated with CPAP, outcomes were poor if more than 50% of measured temperatures indicated hypothermia (5.6% survival). In contrast, all 30 neonates treated with CPAP and with more than 50% of temperature measurements above 35.8°C survived to discharge, regardless of initial temperature. The results of our study suggest that successful implementation of CPAP to treat RDS in low-resource settings will require aggressive action to prevent persistent hypothermia. However, our results show that even babies who are initially cold can do well on CPAP with proper management of hypothermia.

Stereomotion speed perception: contributions from both changing disparity and interocular velocity difference over a range of relative disparities

NASA Technical Reports Server (NTRS)

Brooks, Kevin R.; Stone, Leland S.

2004-01-01

The role of two binocular cues to motion in depth-changing disparity (CD) and interocular velocity difference (IOVD)- was investigated by measuring stereomotion speed discrimination and static disparity discrimination performance (stereoacuity). Speed discrimination thresholds were assessed both for random dot stereograms (RDS), and for their temporally uncorrelated equivalents, dynamic random dot stereograms (DRDS), at relative disparity pedestals of -19, 0, and +19 arcmin. While RDS stimuli contain both CD and IOVD cues, DRDS stimuli carry only CD information. On average, thresholds were a factor of 1.7 higher for DRDS than for RDS stimuli with no clear effect of relative disparity pedestal. Results were similar for approaching and receding targets. Variations in stimulus duration had no significant effect on thresholds, and there was no observed correlation between stimulus displacement and perceived speed, confirming that subjects responded to stimulus speed in each condition. Stereoacuity was equally good for our RDS and DRDS stimuli, showing that the difference in stereomotion speed discrimination performance for these stimuli was not due to any difference in the precision of the disparity cue. In addition, when we altered stereomotion stimulus trajectory by independently manipulating the speeds and directions of its monocular half-images, perceived stereomotion speed remained accurate. This finding is inconsistent with response strategies based on properties of either monocular half-image motion, or any ad hoc combination of the monocular speeds. We conclude that although subjects are able to discriminate stereomotion speed reliably on the basis of CD information alone, IOVD provides a precise additional cue to stereomotion speed perception.

LED-CE-DOAS measurements of NO2: intercomparison with CaRDS

NASA Astrophysics Data System (ADS)

Thalman, R. M.; Washenfelder, R.; Brown, S. S.; Volkamer, R.

2009-04-01

The combination of cavity enhanced absorption spectroscopy (CEAS) with Light Emitting Diode (LED) light sources lends itself to the application of the well established Differential Optical Absorption Spectroscopy (DOAS) technique (LED-CE-DOAS). In contrast to other broad band CEAS (BB-CEAS) techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e., does not require knowledge of the light intensity in the absence of trace gases (I0). With CE-DOAS there is no necessity for sampling lines to supply air samples into a cavity, or filters to remove aerosols from the airstream, as measurements are possible in a cavity that can be open to the atmosphere. A novel LED-CE-DOAS instrument was built at CU Boulder for the sensitive and selective detection of nitrogen dioxide (NO2), glyoxal (CHOCHO), iodine oxide (IO), water, and oxygen dimers (O4). CU Boulder's LED-CE-DOAS instrument was collocated to NOAA's NO2 Cavity Ring Down (CaRDS) instrument to test different CE-DOAS data retrieval algorithms for NO2 and O4. Both instruments were collocated to sample known NO2 concentrations from the same gas manifold, and to sample atmospheric air in a parking lot. This contribution focuses on the instrument components, challenges and means to retrieve quantitative concentrations of NO2 by LED-CE-DOAS, i.e., the distortion of NO2 and O4 absorption features due to different effective path lengths induced by (1) changes in the mirror reflectivity with wavelength, and (2) changes in light extinction across the absorption bands due to differential trace gas absorption features. We demonstrate that simultaneous measurements of O4 and NO2 enable to characterize the effective pathlength in the absence and presence of NO2 and perform absolute measurements based only on relative intensity measurements. To our knowledge these are the first CEAS measurements that rely solely on relative intensity measurements.

Total antioxidant capacity and starch digestibility of muffins baked with rice, wheat, oat, corn and barley flour.

PubMed

Soong, Yean Yean; Tan, Seow Peng; Leong, Lai Peng; Henry, Jeya Kumar

2014-12-01

Muffins are a popular snack consumed in western and emerging countries. Increased glycemic load has been implicated in the aetiology of diabetes. This study examined the starch digestibility of muffins baked with rice, wheat, corn, oat and barley flour. Rapidly digested starch (RDS) was greatest in rice (445 mg/g) and wheat (444 mg/g) muffins, followed by oat (416 mg/g), corn (402 mg/g) and barley (387 mg/g). Total phenolic content was found to be positively correlated with total antioxidative capacity and inversely related to the RDS of muffins. The phenolic content was highest in muffin baked with barley flour (1,687 μg/g), followed by corn (1,454 μg/g), oat (945 μg/g), wheat (705 μg/g), and rice (675 μg/g) flour. Browning was shown not to correlate with free radical scavenging capacity and digestibility of muffins. The presence of high phenolic content and low RDS makes barley muffin an ideal snack to modulate glycemic response. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preterm premature ruptured membranes: a randomized trial of steroids after treatment with antibiotics.

PubMed

Lewis, D F; Brody, K; Edwards, M S; Brouillette, R M; Burlison, S; London, S N

1996-11-01

To assess the effectiveness of corticosteroids in patients with preterm premature rupture of membranes (PROM) after treatment with a broad-spectrum antibiotic, ampicillin-sulbactam. A randomized clinical trial of corticosteroids in patients with preterm PROM was undertaken after treating these patients for a minimum of 12 hours with ampicillin-sulbactam. No digital vaginal examinations were performed on these patients. Antibiotics were continued for 7 days and the steroids were repeated weekly. No tocolytics were used. The primary outcome measure was the incidence of respiratory distress syndrome (RDS). Secondary outcome measures included latency period and neonatal and maternal infectious morbidity. Seventy-seven patients were enrolled and data about their pregnancies were analyzed. No statistically significant difference in latency period was noted (14.7 days in the steroid group, 15.8 days in the no-steroid group). Both neonatal and maternal infectious morbidity were similar. A significant reduction in the incidence of RDS (18.4 versus 43.6%, P = .03) were observed in the steroid group. These data suggest that treating preterm PROM patients with a broad-spectrum antibiotic before corticosteroids decreases RDS without apparent adverse sequelae.

A Genuine TEAM Player

NASA Technical Reports Server (NTRS)

2001-01-01

Qualtech Systems, Inc. developed a complete software system with capabilities of multisignal modeling, diagnostic analysis, run-time diagnostic operations, and intelligent interactive reasoners. Commercially available as the TEAMS (Testability Engineering and Maintenance System) tool set, the software can be used to reveal unanticipated system failures. The TEAMS software package is broken down into four companion tools: TEAMS-RT, TEAMATE, TEAMS-KB, and TEAMS-RDS. TEAMS-RT identifies good, bad, and suspect components in the system in real-time. It reports system health results from onboard tests, and detects and isolates failures within the system, allowing for rapid fault isolation. TEAMATE takes over from where TEAMS-RT left off by intelligently guiding the maintenance technician through the troubleshooting procedure, repair actions, and operational checkout. TEAMS-KB serves as a model management and collection tool. TEAMS-RDS (TEAMS-Remote Diagnostic Server) has the ability to continuously assess a system and isolate any failure in that system or its components, in real time. RDS incorporates TEAMS-RT, TEAMATE, and TEAMS-KB in a large-scale server architecture capable of providing advanced diagnostic and maintenance functions over a network, such as the Internet, with a web browser user interface.

Correlates of sexual violence among Men who have sex with Men (MSM) in Tijuana, Mexico

PubMed Central

Semple, Shirley J.; Stockman, Jamila K.; Goodman-Meza, David; Pitpitan, Eileen V.; Strathdee, Steffanie A.; Chavarin, Claudia V.; Rangel, Gudelia; Torres, Karla; Patterson, Thomas L.

2016-01-01

Sexual violence against men who have sex with men (MSM) is prevalent in developing countries and is associated with increased HIV/STI risk. Despite high HIV prevalence (20%) among MSM in Tijuana, Mexico, little attention has been paid to the occurrence of sexual violence in this high-risk group. The present study used a syndemic conditions framework to examine correlates of sexual violence victimization in a sample of 201 MSM surveyed in Tijuana, Mexico during 2012 and 2013. Participants were recruited through respondent-driven sampling (RDS) and underwent a two-hour baseline interview and testing for HIV and syphilis. Sexual violence was defined as any incident during the past year in which the participant had been raped, sexually molested, or sexually harassed. The majority of participants self-identified as gay or bisexual, had never married, were employed, and had a high school education or greater. The average age was 29.7 years. Thirty-nine percent reported sexual violence in the past year. A hierarchical multiple linear regression model predicting more experiences of sexual violence was tested. In a final model, a higher number of experiences of sexual violence was associated with a history of childhood sexual abuse, more adult experiences of homophobia, more depression and hostility symptoms, and not living with a spouse or steady partner. The findings from this study support a model of co-occurring psychosocial factors that increase the likelihood of sexual violence experiences among MSM. Multi-level approaches to the prevention of childhood and adult experiences of sexual violence and homophobia are needed to avert the development of adverse mental and physical health outcomes associated with sexual violence victimization. PMID:27178173

High levels of unprotected anal intercourse and never testing for HIV among men who have sex with men in Nigeria: evidence from a cross-sectional survey for the need for innovative approaches to HIV prevention.

PubMed

Vu, Lung; Andrinopoulos, Katherine; Tun, Waimar; Adebajo, Sylvia

2013-12-01

To describe sexual risk behaviour, correlates of unprotected anal intercourse (UAI) and never testing for HIV and its implications for HIV prevention interventions among men who have sex with men (MSM) in Nigeria and other similar contexts. A cross-sectional survey was administered to 712 MSM in Abuja, Ibadan and Lagos, recruited through respondent-driven sampling (RDS). Levels of sexual risk behaviour and never having tested for HIV prior to the survey were calculated using weighted data for each city and unweighted data for the pooled sample. Correlates of UAI and never testing for HIV were determined using multiple logistic regression. The risk for HIV and STI among MSM in Nigeria is high, with 43.4% reporting UAI at last sex, 45.1% never having been tested for HIV and 53.9% reporting exchange of sex for resources in the past 6 months. Correlates of UAI in multivariate analysis included living in Ibadan, marriage or cohabitation with a woman, identification as bisexual, not having tested for HIV and being HIV-positive. Correlates of not having tested for HIV in multivariate analysis included living in Ibadan, young age, less education, unemployment and report of UAI. HIV testing is low and associated with UAI. Findings merit targeted and innovative approaches for HIV prevention for MSM, especially access to HIV self-testing. Attention to social and structural determinants of health-seeking and sexual risk behaviour is also needed, including the criminalisation of homosexuality and social marginalisation of MSM.

HIV and Other Sexually Transmitted Infections among Men Who Have Sex with Men Recruited by RDS in Buenos Aires, Argentina: High HIV and HPV Infection

PubMed Central

Pando, María A.; Balán, Iván C.; Marone, Rubén; Dolezal, Curtis; Leu, Cheng-Shiun; Squiquera, Luis; Barreda, Victoria; Rodriguez Fermepín, Marcelo; Gallo Vaulet, Lucia; Rey, Jorge; Picconi, María; Carballo-Diéguez, Alex; Avila, María M.

2012-01-01

Background The aim of this study was to estimate the prevalence of HIV and other STIs, among MSM from Buenos Aires (2007–2009). Methods Responding Driven Sampling was used for recruitment of MSM. Participants completed a structured web-based survey and provided biological samples. Results A total of 496 MSM were studied for HIV, HBV, HCV, and T pallidum infections. Chlamydia and HPV diagnoses were only performed in 98 and 109 participants, respectively. Prevalence of HIV was 17.3%, HBV 22.9%, HCV 7.5%, T pallidum 20.5%, HPV 83.5%, and C trachomatis 1.7%. In the year prior to the evaluation, 71% of the participants had had sex with men and/or trans and women (MMW) while 29% had not had sex with women (MM). Comparing MM to MMW, prevalence of HIV (30.7% vs. 11.9%, p<0.001), HBV (36.4% vs. 17.8%, p<0.001), T pallidum (32.1% vs. 15.7%, p<0.001), and HPV (88.3% vs. 70.4%, p = 0.039) were significantly higher among MM, whereas no significant differences were found for HCV and C trachomatis. The MM group had also significantly higher HIV incidence (5.60 vs. 4.28 per 100 persons-year, p = 0.032). HPV genotypes 16, 6, and 11 were the most frequently found; 40.7% of the MSM had more than one genotype and one high risk genotype was detected in 43.6% of participants. Conclusions Both MM and MMW are at high risk of infection for HIV and other STIs. Rates of HIV, HBV, T pallidum and HPV infections are higher in the MM group. PMID:22768137

Building research capital to facilitate research.

PubMed

Green, Gill; Rein, Melanie

2013-04-04

The National Institute for Health Research, Research Design Service (NIHR RDS) was set up to increase the number and proportion of high quality applications for funding for applied and patient focused health and social care research. Access to specialist expertise and collaboration between researchers and health practitioners at the proposal development stage is crucial for high quality applied health research. In this essay we develop the concept of 'research capital' to describe the wide range of resources and expertise required to develop fundable research projects. It highlights the key role the RDS plays supporting researchers to broker relationships to access the requisite 'research capital'.

Impact of hypothermia on implementation of CPAP for neonatal respiratory distress syndrome in a low-resource setting

PubMed Central

Kawaza, Kondwani; Quinn, MK; Miao, Yinsen; Guerra, Rudy; Molyneux, Elizabeth; Oden, Maria; Richards-Kortum, Rebecca

2018-01-01

Background Neonatal hypothermia is widely associated with increased risks of morbidity and mortality, but remains a pervasive global problem. No studies have examined the impact of hypothermia on outcomes for preterm infants treated with CPAP for respiratory distress syndrome (RDS). Methods This retrospective analysis assessed the impact of hypothermia on outcomes of 65 neonates diagnosed with RDS and treated with either nasal oxygen (N = 17) or CPAP (N = 48) in a low-resource setting. A classification tree approach was used to develop a model predicting survival for subjects diagnosed with RDS. Findings Survival to discharge was accurately predicted based on three variables: mean temperature, treatment modality, and mean respiratory rate. None of the 23 neonates with a mean temperature during treatment below 35.8°C survived to discharge, regardless of treatment modality. Among neonates with a mean temperature exceeding 35.8°C, the survival rate was 100% for the 31 neonates treated with CPAP and 36.4% for the 11 neonates treated with nasal oxygen (p<0.001). For neonates treated with CPAP, outcomes were poor if more than 50% of measured temperatures indicated hypothermia (5.6% survival). In contrast, all 30 neonates treated with CPAP and with more than 50% of temperature measurements above 35.8°C survived to discharge, regardless of initial temperature. Conclusion The results of our study suggest that successful implementation of CPAP to treat RDS in low-resource settings will require aggressive action to prevent persistent hypothermia. However, our results show that even babies who are initially cold can do well on CPAP with proper management of hypothermia. PMID:29543861

Challenges in Research and Health Technology Assessment of Rare Disease Technologies: Report of the ISPOR Rare Disease Special Interest Group.

PubMed

Nestler-Parr, Sandra; Korchagina, Daria; Toumi, Mondher; Pashos, Chris L; Blanchette, Christopher; Molsen, Elizabeth; Morel, Thomas; Simoens, Steven; Kaló, Zoltán; Gatermann, Ruediger; Redekop, William

2018-05-01

Successful development of new treatments for rare diseases (RDs) and their sustainable patient access require overcoming a series of challenges related to research and health technology assessment (HTA). These impediments, which may be unique to RDs or also apply to common diseases but are particularly pertinent in RDs, are diverse and interrelated. To develop for the first time a catalog of primary impediments to RD research and HTA, and to describe the cause and effect of individual challenges. Challenges were identified by an international 22-person expert working group and qualitative outreach to colleagues with relevant expertise. A broad range of stakeholder perspectives is represented. Draft results were presented at annual European and North American International Society for Pharmacoeconomics and Outcomes Research (ISPOR) congresses, and written comments were received by the 385-strong ISPOR Rare Disease Review Group from two rounds of review. Findings were refined and confirmed via targeted literature search. Research-related challenges linked to the low prevalence of RDs were categorized into those pertaining to disease recognition and diagnosis, evaluation of treatment effect, and patient recruitment for clinical research. HTA-related challenges were classified into issues relating to the lack of a tailored HTA method for RD treatments and uncertainty for HTA agencies and health care payers. Identifying and highlighting diverse, but interrelated, key challenges in RD research and HTA is an essential first step toward developing implementable and sustainable solutions. A collaborative multistakeholder effort is required to enable faster and less costly development of safe, efficacious, and appropriate new RD therapies that offer value for money. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Macrophage phenotype is associated with disease severity in preterm infants with chronic lung disease.

PubMed

Prince, Lynne R; Maxwell, Nicola C; Gill, Sharonjit K; Dockrell, David H; Sabroe, Ian; McGreal, Eamon P; Kotecha, Sailesh; Whyte, Moira K

2014-01-01

The etiology of persistent lung inflammation in preterm infants with chronic lung disease of prematurity (CLD) is poorly characterized, hampering efforts to stratify prognosis and treatment. Airway macrophages are important innate immune cells with roles in both the induction and resolution of tissue inflammation. To investigate airway innate immune cellular phenotypes in preterm infants with respiratory distress syndrome (RDS) or CLD. Bronchoalveolar lavage (BAL) fluid was obtained from term and preterm infants requiring mechanical ventilation. BAL cells were phenotyped by flow cytometry. Preterm birth was associated with an increase in the proportion of non-classical CD14(+)/CD16(+) monocytes on the day of delivery (58.9 ± 5.8% of total mononuclear cells in preterm vs 33.0 ± 6.1% in term infants, p = 0.02). Infants with RDS were born with significantly more CD36(+) macrophages compared with the CLD group (70.3 ± 5.3% in RDS vs 37.6 ± 8.9% in control, p = 0.02). At day 3, infants born at a low gestational age are more likely to have greater numbers of CD14(+) mononuclear phagocytes in the airway (p = 0.03), but fewer of these cells are functionally polarized as assessed by HLA-DR (p = 0.05) or CD36 (p = 0.05) positivity, suggesting increased recruitment of monocytes or a failure to mature these cells in the lung. These findings suggest that macrophage polarization may be affected by gestational maturity, that more immature macrophage phenotypes may be associated with the progression of RDS to CLD and that phenotyping mononuclear cells in BAL could predict disease outcome.

Professional and patient perspectives on nutritional needs of patients with cancer.

PubMed

Hartmuller, Vriginia W; Desmond, Sharon M

2004-09-01

To identify and compare perceptions of RNs, registered dietitians (RDs), and patients regarding the best format and key nutrition information components that should be provided to patients during cancer treatment. Cross-sectional study using an opinion-based questionnaire. Outpatient cancer centers. 506 RNs and 367 RDs, as well as 653 patients undergoing cancer treatment. Two similar self-administered questionnaires were developed, one for patients and one for healthcare professionals. Face and content validity were assessed by a panel of experts. Data were analyzed using descriptive statistics, chi-square statistic, and a Spearman Correlation Coefficient to compare responses. Patient nutrition concerns as well as format and content of printed educational materials. Significant differences existed among groups regarding the most common nutrition concerns, the perception of importance of information frequently provided to patients with cancer, and rank order of importance for eight items typically provided to patients. The dietary information format preferred by all groups was an all-inclusive booklet; RNs (75%) were more likely than RDs (43%) or patients (50%) to prefer this format. Data also revealed that almost half of the patients (47%) received no dietary counseling, including 18% who experienced significant weight loss. RNs and RDs who provide nutrition education to patients with cancer should consider the need to develop and use a variety of printed materials to meet individual needs. Because major concerns of patients and healthcare professionals were related to patients ability to consume adequate amounts of food, this should be the primary focus of any nutrition education materials. These findings provide information that can be applied to the development of informational materials and counseling practices.

An inducible amphipathic helix within the intrinsically disordered C terminus can participate in membrane curvature generation by peripherin-2/rds.

PubMed

Milstein, Michelle L; Kimler, Victoria A; Ghatak, Chiranjib; Ladokhin, Alexey S; Goldberg, Andrew F X

2017-05-12

Peripherin-2/rds is required for biogenesis of vertebrate photoreceptor outer segment organelles. Its localization at the high-curvature rim domains of outer segment disk membranes suggests that it may act to shape these structures; however, the molecular function of this protein is not yet resolved. Here, we apply biochemical, biophysical, and imaging techniques to elucidate the role(s) played by the protein's intrinsically disordered C-terminal domain and an incipient amphipathic α-helix contained within it. We investigated a deletion mutant lacking only this α-helix in stable cell lines and Xenopus laevis photoreceptors. We also studied a soluble form of the full-length ∼7-kDa cytoplasmic C terminus in cultured cells and purified from Escherichia coli The α-helical motif was not required for protein biosynthesis, tetrameric subunit assembly, tetramer polymerization, localization at disk rims, interaction with GARP2, or the generation of membrane curvature. Interestingly, however, loss of the helical motif up-regulated membrane curvature generation in cellulo , introducing the possibility that it may regulate this activity in photoreceptors. Furthermore, the incipient α-helix (within the purified soluble C terminus) partitioned into membranes only when its acidic residues were neutralized by protonation. This suggests that within the context of full-length peripherin-2/rds, partitioning would most likely occur at a bilayer interfacial region, potentially adjacent to the protein's transmembrane domains. In sum, this study significantly strengthens the evidence that peripherin-2/rds functions directly to shape the high-curvature rim domains of the outer segment disk and suggests that the protein's C terminus may modulate membrane curvature-generating activity present in other protein domains. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Diagnostic algorithm for relapsing acquired demyelinating syndromes in children.

PubMed

Hacohen, Yael; Mankad, Kshitij; Chong, W K; Barkhof, Frederik; Vincent, Angela; Lim, Ming; Wassmer, Evangeline; Ciccarelli, Olga; Hemingway, Cheryl

2017-07-18

To establish whether children with relapsing acquired demyelinating syndromes (RDS) and myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) show distinctive clinical and radiologic features and to generate a diagnostic algorithm for the main RDS for clinical use. A panel reviewed the clinical characteristics, MOG-Ab and aquaporin-4 (AQP4) Ab, intrathecal oligoclonal bands, and Epstein-Barr virus serology results of 110 children with RDS. A neuroradiologist blinded to the diagnosis scored the MRI scans. Clinical, radiologic, and serologic tests results were compared. The findings showed that 56.4% of children were diagnosed with multiple sclerosis (MS), 25.4% with neuromyelitis optica spectrum disorder (NMOSD), 12.7% with multiphasic disseminated encephalomyelitis (MDEM), and 5.5% with relapsing optic neuritis (RON). Blinded analysis defined baseline MRI as typical of MS in 93.5% of children with MS. Acute disseminated encephalomyelitis presentation was seen only in the non-MS group. Of NMOSD cases, 30.7% were AQP4-Ab positive. MOG-Ab were found in 83.3% of AQP4-Ab-negative NMOSD, 100% of MDEM, and 33.3% of RON. Children with MOG-Ab were younger, were less likely to present with area postrema syndrome, and had lower disability, longer time to relapse, and more cerebellar peduncle lesions than children with AQP4-Ab NMOSD. A diagnostic algorithm applicable to any episode of CNS demyelination leads to 4 main phenotypes: MS, AQP4-Ab NMOSD, MOG-Ab-associated disease, and antibody-negative RDS. Children with MS and AQP4-Ab NMOSD showed features typical of adult cases. Because MOG-Ab-positive children showed notable and distinctive clinical and MRI features, they were grouped into a unified phenotype (MOG-Ab-associated disease), included in a new diagnostic algorithm. © 2017 American Academy of Neurology.

Effect of Treatment of Premature Infants with Respiratory Distress Using Low-cost Bubble CPAP in a Rural African Hospital.

PubMed

Myhre, Jennifer; Immaculate, Mutisya; Okeyo, Bob; Anand, Matthew; Omoding, Anastacia; Myhre, Luke; Okeyo, Lilian; Barasa, Immaculate; Letchford, Steve

2016-10-01

Kenya's neonatal mortality rate remains unacceptably high, at 22 deaths per 1000 live births, with a third of those attributable to prematurity. Respiratory distress syndrome (RDS) is the single most important cause of morbidity and mortality in the premature neonate. Continuous positive airway pressure (CPAP) is a proven modality of therapy but is rarely used in low-resource settings. We report on the introduction of bubble CPAP (BCPAP), a low-cost method of delivering CPAP appropriate to our setting, by comparing survival-to-discharge before and after the technology was introduced. The inpatient hospital records of all preterm infants (<37 weeks) diagnosed with RDS in the AIC Kijabe Hospital Nursery during two 18-month periods before and after the introduction of BCPAP (46 infants enrolled from 1 November 2007 to 30 April 2009 vs. 72 infants enrolled from 1 November 2009 to 30 April 2011) were reviewed. Differences in survival-to-discharge rates between the two time periods were analyzed. The survival-to-discharge rate was higher in Period 2 (after the introduction of BCPAP) than in Period 1 (pre-BCPAP) (85% vs. 61%, p  =  0.007). Similarly, there were lower referral rates of preterm infants with RDS in Period 2 than Period 1 (4% vs. 17%, p  =  0.037). BCPAP has contributed significantly to favorable outcomes for preterm infants with RDS at AIC Kijabe Hospital. The use of this simple technology should be considered and studied for expansion to all hospitals in Kenya that care for preterm infants. © The Author [2016]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sexual and reproductive health services utilization by female sex workers is context-specific: results from a cross-sectional survey in India, Kenya, Mozambique and South Africa.

PubMed

Lafort, Yves; Greener, Ross; Roy, Anuradha; Greener, Letitia; Ombidi, Wilkister; Lessitala, Faustino; Skordis-Worrall, Jolene; Beksinska, Mags; Gichangi, Peter; Reza-Paul, Sushena; Smit, Jenni A; Chersich, Matthew; Delva, Wim

2017-01-19

Female sex workers (FSWs) are extremely vulnerable to adverse sexual and reproductive health (SRH) outcomes. To mitigate these risks, they require access to services covering not only HIV prevention but also contraception, cervical cancer screening and sexual violence. To develop context-specific intervention packages to improve uptake, we identified gaps in service utilization in four different cities. A cross-sectional survey was conducted, as part of the baseline assessment of an implementation research project. FWSs were recruited in Durban, South Africa (n = 400), Mombasa, Kenya (n = 400), Mysore, India (n = 458) and Tete, Mozambique (n = 308), using respondent-driven sampling (RDS) and starting with 8-16 'seeds' identified by the peer educators. FSWs responded to a standardised interviewer-administered questionnaire about the use of contraceptive methods and services for cervical cancer screening, sexual violence and unwanted pregnancies. RDS-adjusted proportions and surrounding 95% confidence intervals were estimated by non-parametric bootstrapping, and compared across cities using post-hoc pairwise comparison tests with Dunn-Šidák correction. Current use of any modern contraception ranged from 86.2% in Tete to 98.4% in Mombasa (p = 0.001), while non-barrier contraception (hormonal, IUD or sterilisation) varied from 33.4% in Durban to 85.1% in Mysore (p < 0.001). Ever having used emergency contraception ranged from 2.4% in Mysore to 38.1% in Mombasa (p < 0.001), ever having been screened for cervical cancer from 0.0% in Tete to 29.0% in Durban (p < 0.001), and having gone to a health facility for a termination of an unwanted pregnancy from 15.0% in Durban to 93.7% in Mysore (p < 0.001). Having sought medical care after forced sex varied from 34.4% in Mombasa to 51.9% in Mysore (p = 0.860). Many of the differences between cities remained statistically significant after adjusting for variations in FSWs' sociodemographic characteristics. The use of SRH commodities and services by FSWs is often low and is highly context-specific. Reasons for variation across cities need to be further explored. The differences are unlikely caused by differences in socio-demographic characteristics and more probably stem from differences in the availability and accessibility of SRH services. Intervention packages to improve use of contraceptives and SRH services should be tailored to the particular gaps in each city.

Competition is not necessarily a barrier to community mobilisation among sex workers: an intervention planning assessment from Zimbabwe.

PubMed

Mtetwa, Sibongile; Busza, Joanna; Davey, Calum; Wong-Gruenwald, Ramona; Cowan, Frances

2015-08-16

Community mobilization among female sex workers (SWs) is recognized as an effective strategy to empower SWs and increase their uptake of health services. Activities focus on increasing social cohesion between SWs by building trust, strengthening networks, and encouraging shared efforts for mutual gain. Several studies, however, suggest that high levels of interpersonal competition between SWs can pose a barrier to collective action and support. We conducted a study to examine levels of perceived competition between SWs in Mutare, Hwange and Victoria Falls in Zimbabwe in order to inform development of a community-based intervention for HIV prevention and treatment. This paper focuses on our qualitative findings and their implications for the design of HIV programming in the Zimbabwean context. Following a respondent driven sampling (RDS) survey, we explored issues related to social cohesion amongst SWs in Mutare, Hwange and Victoria Falls through in-depth interviews conducted with 22 SWs. Interviews examined dynamics of SWs' relationships and extent of social support, and were analyzed using thematic content analysis using the constant comparative method. Findings are contextualised against descriptive data extracted from the survey, which was analysed using Stata 12, adjusting for RDS. Across all sites, women described protecting each other at night, advising each other about violent or non-paying clients, and paying fines for each other following arrest. In Mutare, women gave additional examples, including physically attacking problem clients, treatment adherence support and shared saving schemes. However, interviews also highlighted fierce competition between women and deep mistrust. This reflects the reported mix of competition and support from the survey of 836 women (Mutare n = 370, Hwange n = 237, Victoria Falls n = 229). In Mutare, 92.8 % of SWs agreed there was a lot of competition; 87.9 % reported that SWs support each other. This contrasted with Victoria Falls and Hwange where fewer agreed there was competition between SWs (70.5 % and 78.0 %), but also fewer reported that SWs support each other at work (55.2 % and 51.2 %). Women reported being most likely to support each other when confronted with serious danger but maintained high levels of competition for clients, suggesting competition at work does not represent a barrier to support. Examples of practical assistance between SWs provide entry points for our planned community mobilization activities, which aim to broaden trust and support among SWs while acknowledging their professional competition.

Gay and bisexual men's awareness and knowledge of treatment as prevention: findings from the Momentum Health Study in Vancouver, Canada.

PubMed

Carter, Allison; Lachowsky, Nathan; Rich, Ashleigh; Forrest, Jamie I; Sereda, Paul; Cui, Zishan; Roth, Eric; Kaida, Angela; Moore, David; Montaner, Julio Sg; Hogg, Robert S

2015-01-01

Awareness and knowledge of treatment as prevention (TasP) was assessed among HIV-positive and HIV-negative gay, bisexual and other men who have sex with men (GBMSM) in Vancouver, Canada. Baseline cross-sectional survey data were analyzed for GBMSM enrolled, via respondent-driven sampling (RDS), in the Momentum Health Study. TasP awareness was defined as ever versus never heard of the term "TasP." Multivariable logistic regression identified covariates of TasP awareness. Among those aware of TasP, men's level of knowledge of TasP was explored through an examination of self-perceived knowledge levels, risk perceptions and short-answer definitions of TasP which were coded as "complete" if three TasP-related components were identified (i.e. HIV treatment, viral suppression and prevention of transmission). Information source was also assessed. Analyses were stratified by HIV status and RDS adjusted. Of 719 participants, 23% were HIV-positive, 68% Caucasian and median age was 33 (Interquartile range (IQR) 26,47). Overall, 46% heard of TasP with differences by HIV status [69% HIV-positive vs. 41% HIV-negative GBMSM (p<0.0001)]. In adjusted models: HIV-positive GBMSM were more likely to have heard of TasP if they were Canadian born, unemployed, not using party drugs and had higher CD4 counts; HIV-negative GBMSM were more likely to have heard of TasP if they were Caucasian (vs. Aboriginal), students, had higher education, a regular partner and multiple sexual partners. Among those aware of TasP 91% of HIV-positive and 69% of HIV-negative GBMSM (p<0.0001) felt they knew "a lot" or "a bit in general" about TasP; 64 and 41% (p=0.002) felt HIV treatment made the risk of transmission "a lot lower"; and 21 and 13% (p<0.0001) demonstrated "complete" TasP definitions. The leading information source was doctors (44%) for HIV-positive GBMSM and community agencies (38%) for HIV-negative GBMSM, followed by gay media for both populations (34%). Nearly half of GBMSM in this study reported having heard of TasP, yet only 14% demonstrated complete understanding of the concept. Variations in TasP awareness and knowledge by HIV status, and key socio-demographic, behavioural and clinical factors, highlight a need for health communication strategies relevant to diverse communities of GBMSM in order to advance overall TasP health literacy.

Digenic retinitis pigmentosa due to mutations at the unlinked peripherin/RDS and ROM1 loci

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kajiwara, K.; Berson, E.L.; Dryja, T.P.

1994-06-10

In spite of recent advances in identifying genes causing monogenic human disease, very little is known about the genes involved in polygenic disease. Three families were identified with mutations in the unlinked photoreceptor-specific genes ROM 1 and peripherin/RDS, in which only double heterozygotes develop retinitis pigmentosa (RP). These findings indicate that the allelic and nonallelic heterogeneity known to be a feature of monogenic RP is complicated further by interactions between unlinked mutations causing digenic RP. Recognition of the inheritance pattern exemplified by these three families might facilitate the identification of other examples of digenic inheritance in human disease.

Common Neurogenetic Diagnosis and Meso-Limbic Manipulation of Hypodopaminergic Function in Reward Deficiency Syndrome (RDS): Changing the Recovery Landscape.

PubMed

Blum, Kenneth; Febo, Marcelo; Badgaiyan, Rajendra D; Demetrovics, Zsolt; Simpatico, Thomas; Fahlke, Claudia; M, Oscar-Berman; Li, Mona; Dushaj, Kristina; Gold, Mark S

2017-01-01

In 1990, Blum and associates provided the first confirmed genetic link between the DRD2 polymorphisms and alcoholism. This finding was based on an earlier conceptual framework, which served as a blueprint for their seminal genetic association discovery they termed "Brain Reward Cascade." These findings were followed by a new way of understanding all addictive behaviors (substance and non-substance) termed "Reward Deficiency Syndrome" (RDS). RDS incorporates a complex multifaceted array of inheritable behaviors that are polygenic. In this review article, we attempt to clarify these terms and provide a working model to accurately diagnose and treat these unwanted behaviors. We are hereby proposing the development of a translational model we term "Reward Deficiency Solution System™" that incorporates neurogenetic testing and meso-limbic manipulation of a "hypodopaminergic" trait/state, which provides dopamine agonistic therapy (DAT) as well as reduced "dopamine resistance," while embracing "dopamine homeostasis." The result is better recovery and relapse prevention, despite DNA antecedents, which could impact the recovery process and relapse. Understanding the commonality of mental illness will transform erroneous labeling based on symptomatology, into a genetic and anatomical etiology. WC: 184.

Resource utilization patterns using non-invasive ventilation in neonates with respiratory distress syndrome.

PubMed

Chavez, Thomas A; Lakshmanan, Ashwini; Figueroa, Lizzette; Iyer, Narayan; Stavroudis, Theodora A; Garingo, Arlene; Friedlich, Philippe S; Ramanathan, Rangasamy

2018-05-24

To describe the frequency of non-invasive ventilation (NIV) and endotracheal intubation use in neonates diagnosed with respiratory distress syndrome (RDS); to describe resources utilization (length of stay (LOS), charges, costs) among NIV and intubated RDS groups. Retrospective study from the national Kid's Inpatient Database of the Healthcare Cost and Utilization Project, for the years 1997-2012. Propensity scoring and multivariate regression analysis used to describe differences. A total of 595,254 out of 42,912,090 cases were identified with RDS. There was an increase in NIV use from 6% in 1997 to 17% in 2012. After matching, patients receiving NIV only were associated with shorter LOS: (95%CI) 25 (25.3,25.7) vs. 35 (34.2,34.9) days, decreased costs: ($/1k) 46.1 (45.5,46.8) vs. 65.0 (64.1,66.0), decreased charges: 130.3 (128.6,132.1) vs. 192.1 (189.5,194.6) compared to intubated neonates. There was a three-fold increase in NIV use within the 15-year study period. NIV use was associated with decreased LOS, charges and costs compared to intubated patients.

Pressure oscillation delivery to the lung: Computer simulation of neonatal breathing parameters.

PubMed

Al-Jumaily, Ahmed M; Reddy, Prasika I; Bold, Geoff T; Pillow, J Jane

2011-10-13

Preterm newborn infants may develop respiratory distress syndrome (RDS) due to functional and structural immaturity. A lack of surfactant promotes collapse of alveolar regions and airways such that newborns with RDS are subject to increased inspiratory effort and non-homogeneous ventilation. Pressure oscillation has been incorporated into one form of RDS treatment; however, how far it reaches various parts of the lung is still questionable. Since in-vivo measurement is very difficult if not impossible, mathematical modeling may be used as one way of assessment. Whereas many models of the respiratory system have been developed for adults, the neonatal lung remains essentially ill-described in mathematical models. A mathematical model is developed, which represents the first few generations of the tracheo-bronchial tree and the 5 lobes that make up the premature ovine lung. The elements of the model are derived using the lumped parameter approach and formulated in Simulink™ within the Matlab™ environment. The respiratory parameters at the airway opening compare well with those measured from experiments. The model demonstrates the ability to predict pressures, flows and volumes in the alveolar regions of a premature ovine lung. Copyright © 2011 Elsevier Ltd. All rights reserved.

Is there a necessity for multiple doses of surfactant for respiratory distress syndrome of premature infants?

PubMed

Tsakalidis, Christos; Giougki, Evangelia; Karagianni, Paraskevi; Dokos, Charalampos; Rallis, Dimitrios; Nikolaidis, Nikolaos

2012-01-01

Both prophylactic and early surfactant (SF) replacement therapy reduce pulmonary complications and mortality in ventilated infants with respiratory distress syndrome (RDS). The effectiveness of one or more doses and the impact on morbidity and mortality of premature neonates with RDS need to be further clarified. The objective of this study was to investigate the necessity of repeated surfactant replacement therapy in premature infants ≤32 weeks of gestational age and the possibility of an underlying pathology. This study included 126 premature neonates of 24-32 weeks of gestation. We used 200 mg/kg per dose of porcine surfactant (Curosurf®) as primary treatment and 100 mg/kg in cases that required retreatment. The subjects were classified into two groups: the first group (Group 1) received a single dose of surfactant (n=98) and the second group (Group 2) included infants who required more than one dose (n=28). The 1st dose was administered in the first 20 minutes after birth while the second was given six hours later. In four cases, a 3rd dose was required, that was provided 12 hours after birth. Recorded data included: clinical and radiological classification of RDS, extubation time, oxygenation estimation indexes (OI: oxygenation index, A-aDO2: alveolar-arterial oxygen difference, a/APO2: arterial-alveolar ratio of partial oxygen pressure), requirement and duration of oxygen administration, total duration of mechanical ventilation, and survival rate. Patient Group 1 did not present any radiological findings of RDS of grade 3 or 4 six hours after SF administration, whereas such findings were recorded in three neonates of Group 2. Therefore, we assumed that failure of a single-dosing treatment indicates a more severe RDS and might reflect an underlying pathology. The impact of maternal chorioamnionitis in the neonates that necessitated further replacement therapy was statistically significant (p=0.045); moreover, infection markers were positive in the majority of the patient population of the second group. Twenty-two neonates (22%) of the first group needed intubation in the delivery room compared to 16 (57%) of the second group (p=0.0001). In conclusion, premature infants treated with a single dose of surfactant can usually be successfully extubated. Requirement of retreatment could be attributed to other pathogenetic mechanisms. A positive history of maternal chorioamnionitis was the commonest reason.

Alberta Infant Motor Scale (AIMS) Performance of Greek Preterm Infants: Comparisons With Full-Term Infants of the Same Nationality and Impact of Prematurity-Related Morbidity Factors.

PubMed

Syrengelas, Dimitrios; Kalampoki, Vassiliki; Kleisiouni, Paraskevi; Manta, Vassiliki; Mellos, Stavros; Pons, Roser; Chrousos, George P; Siahanidou, Tania

2016-07-01

Only a few studies have been conducted with the objective of creating norms of the Alberta Infant Motor Scale (AIMS) for the assessment of gross motor development of preterm infants. The AIMS performance of preterm infants has been compared with that of the Canadian norms of full-term infants, but not with that of full-term infants of the same nationality. Moreover, the possible impact of prematurity-related morbidity factors on AIMS performance is unknown. The aims of this study were: (1) to evaluate AIMS trajectory in a large population of Greek preterm infants and create norms, (2) to compare it with the AIMS trajectory of Greek full-term infants, and (3) to examine the possible influence of neonatal morbidity on AIMS scores in the preterm sample. This was a cross-sectional study. Mean AIMS scores were compared, per month (1-19), between 403 preterm infants (≤32 weeks of age, corrected for prematurity) and 1,038 full-term infants. In preterm infants, the association of AIMS scores with respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH) of grade ≤III, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and sepsis was assessed by hierarchical regression analysis. Alberta Infant Motor Scale scores were significantly lower in preterm infants than in full-term infants. Mean AIMS scores in preterm infants were significantly associated with RDS (b=-1.93; 95% CI=-2.70, -1.16), IVH (b=-0.97; 95% CI=-1.69, -0.25), and ROP (b=-1.12; 95% CI=-1.99, -0.24) but not with BPD or sepsis in hierarchical regression analysis. Alberta Infant Motor Scale norms were created for Greek preterm infants. This study confirms that AIMS trajectories of preterm infants are below those of full-term infants of the same nationality. The influence of morbidity factors, including RDS, IVH, and ROP, should be taken into account when administering the AIMS in preterm infants. © 2016 American Physical Therapy Association.

Serum Lycopene Concentrations and Associations with Clinical Outcomes in a Cohort of Maternal-Infant Dyads.

PubMed

Hanson, Corrine; Lyden, Elizabeth; Furtado, Jeremy; Van Ormer, Matthew; White, Kimberly; Overby, Nina; Anderson-Berry, Ann

2018-02-13

Oxidative stress has been associated with adverse neonatal outcomes, and many carotenoids, including lycopene, potentially have antioxidant properties. The objective of this analysis was to explore the associations between serum lycopene concentrations, including lycopene isomers, and maternal-newborn outcomes. Maternal and cord blood samples were collected in 180 mother-infant pairs. Serum of total lycopene as well as the cis - and trans -isomers concentrations were measured using HPLC (High Performance Liquid Chromatography). Descriptive statistics were calculated; Spearman coefficients were used to assess correlations between maternal and cord concentrations. The relationship between lycopene concentration and outcomes were evaluated with linear and logistic regression models, with adjustment for relevant confounders. A p ≤ 0.05 was considered statistically significant. Maternal and cord serum lycopene concentrations were positively correlated for total lycopene ( r = 0.30, p < 0.0001), cis -lycopene ( r = 0.29, p = 0.0002); and trans -lycopene ( r = 0.32, p < 0.0001). Maternal concentrations of cis -lycopene were significantly lower in mothers whose infants developed respiratory distress syndrome compared to those who did not (0.336 ± 0.171 vs. 0.445 ± 0.238 µmol/L, p = 0.04) and also in mothers whose babies were admitted to the newborn intensive care unit compared to those who were not (0.380 ± 0.202 vs. 0.458 ± 0.244 µmol/L, p = 0.04). Conversely, cord concentrations of trans -lycopene were significantly higher in infants who developed RDS (Respiratory Distress Syndrome) (0.023 ± 0.012 vs. 0.016 ± 0.012, p = 0.007 for RDS vs. no RDS), and a similar pattern was seen NICU admission (0.023 ± 0.016 vs. 0.015 ± 0.009 µmol/L for NICU (Newborn Intensive Care Unit) admission vs. no NICU admission, p = 0.007). Maternal concentrations of total and cis -lycopene were positively associated with infant birth weight, length and head circumference after adjustment for relevant confounders. As serum carotenoids, including lycopene, are modifiable by diet, future research determining the clinical impact of these compounds is warranted.

Kinetics of Electrocatalytic Reactions from First-Principles: A Critical Comparison with the Ab Initio Thermodynamics Approach.

PubMed

Exner, Kai S; Over, Herbert

2017-05-16

Multielectron processes in electrochemistry require the stabilization of reaction intermediates (RI) at the electrode surface after every elementary reaction step. Accordingly, the bond strengths of these intermediates are important for assessing the catalytic performance of an electrode material. Current understanding of microscopic processes in modern electrocatalysis research is largely driven by theory, mostly based on ab initio thermodynamics considerations, where stable reaction intermediates at the electrode surface are identified, while the actual free energy barriers (or activation barriers) are ignored. This simple approach is popular in electrochemistry in that the researcher has a simple tool at hand in successfully searching for promising electrode materials. The ab initio TD approach allows for a rough but fast screening of the parameter space with low computational cost. However, ab initio thermodynamics is also frequently employed (often, even based on a single binding energy only) to comprehend on the activity and on the mechanism of an electrochemical reaction. The basic idea is that the activation barrier of an endergonic reaction step consists of a thermodynamic part and an additional kinetically determined barrier. Assuming that the activation barrier scales with thermodynamics (so-called Brønsted-Polanyi-Evans (BEP) relation) and the kinetic part of the barrier is small, ab initio thermodynamics may provide molecular insights into the electrochemical reaction kinetics. However, for many electrocatalytic reactions, these tacit assumptions are violated so that ab initio thermodynamics will lead to contradictions with both experimental data and ab initio kinetics. In this Account, we will discuss several electrochemical key reactions, including chlorine evolution (CER), oxygen evolution reaction (OER), and oxygen reduction (ORR), where ab initio kinetics data are available in order to critically compare the results with those derived from a simple ab initio thermodynamics treatment. We show that ab initio thermodynamics leads to erroneous conclusions about kinetic and mechanistic aspects for the CER over RuO 2 (110), while the kinetics of the OER over RuO 2 (110) and ORR over Pt(111) are reasonably well described. Microkinetics of an electrocatalyzed reaction is largely simplified by the quasi-equilibria of the RI preceding the rate-determining step (rds) with the reactants. Therefore, in ab initio kinetics the rate of an electrocatalyzed reaction is governed by the transition state (TS) with the highest free energy G rds # , defining also the rate-determining step (rds). Ab initio thermodynamics may be even more powerful, when using the highest free energy of an reaction intermediate G max (RI) rather than the highest free energy difference between consecutive reaction intermediates, ΔG loss , as a descriptor for the kinetics.

Common Neurogenetic Diagnosis and Meso-Limbic Manipulation of Hypodopaminergic Function in Reward Deficiency Syndrome (RDS): Changing the Recovery Landscape

PubMed Central

Blum, Kenneth; Febo, Marcelo; Badgaiyan, Rajendra D.; Demetrovics, Zsolt; Simpatico, Thomas; Fahlke, Claudia; Li, Mona; Dushaj, Kristina; Gold, Mark S.

2017-01-01

Abstract: Background: In 1990, Blum and associates provided the first confirmed genetic link between the DRD2 polymorphisms and alcoholism. This finding was based on an earlier conceptual framework, which served as a blueprint for their seminal genetic association discovery they termed “Brain Reward Cascade.” These findings were followed by a new way of understanding all addictive behaviors (substance and non-substance) termed “Reward Deficiency Syndrome” (RDS). RDS incorporates a complex multifaceted array of inheritable behaviors that are polygenic. Objective: In this review article, we attempt to clarify these terms and provide a working model to accurately diagnose and treat these unwanted behaviors. Method: We are hereby proposing the development of a translational model we term “Reward Deficiency Solution System™” that incorporates neurogenetic testing and meso-limbic manipulation of a “hypodopaminergic” trait/state, which provides dopamine agonistic therapy (DAT) as well as reduced “dopamine resistance,” while embracing “dopamine homeostasis.” Result: The result is better recovery and relapse prevention, despite DNA antecedents, which could impact the recovery process and relapse. Understanding the commonality of mental illness will transform erroneous labeling based on symptomatology, into a genetic and anatomical etiology. WC: 184. PMID:27174576

Bubble CPAP for respiratory distress syndrome in preterm infants.

PubMed

Koti, Jagdish; Murki, Srinivas; Gaddam, Pramod; Reddy, Anupama; Reddy, M Dasaradha Rami

2010-02-01

To ascertain the immediate outcome of preterm infants with respiratory distress syndrome (RDS) on Bubble CPAP and identify risk factors associated with its failure. Prospective analytical study. Inborn preterm infants (gestation 28 to 34 weeks) admitted to the NICU with respiratory distress and chest X ray suggestive of RDS. Bubble CPAP with bi-nasal prongs. CPAP failures infants requiring ventilation in the first one week. 56 neonates were enrolled in the study. 14 (25%) babies failed CPAP. The predictors of failure were; no or only partial exposure to antenatal steroids, white-out on the chest X-ray, patent ductus arteriosus, sepsis/pneumonia and Downes score > 7 or FiO2 > or = 50% after 15-20 minutes of CPAP. Other maternal and neonatal variables did not influence the need for ventilation. Rates of mortality and duration of oxygen requirement was significantly higher in babies who failed CPAP. Only two infants developed pneumothorax. No baby had chronic lung disease. Infants with no or partial exposure to antenatal steroids, white-out chest X-ray, patent ductus arteriosus, sepsis/pneumonia and those with higher FiO2 requirement after initial stabilization on CPAP are at high risk of CPAP failure (needing mechanical ventilation). Bubble CPAP is safe for preterm infants with RDS.

Curcumin for Radiation Dermatitis: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial of Thirty Breast Cancer Patients

PubMed Central

Ryan, Julie L.; Heckler, Charles E.; Ling, Marilyn; Katz, Alan; Williams, Jacqueline P.; Pentland, Alice P.; Morrow, Gary R.

2014-01-01

Radiation dermatitis occurs in approximately 95% of patients receiving radiotherapy (RT) for breast cancer. We conducted a randomized, double-blind, placebo-controlled clinical trial to assess the ability of curcumin to reduce radiation dermatitis severity in 30 breast cancer patients. Eligible patients were adult females with noninflammatory breast cancer or carcinoma in situ prescribed RT without concurrent chemotherapy. Randomized patients took 2.0 grams of curcumin or placebo orally three times per day (i.e., 6.0 grams daily) throughout their course of RT. Weekly assessments included Radiation Dermatitis Severity (RDS) score, presence of moist desquamation, redness measurement, McGill Pain Questionnaire-Short Form and Symptom Inventory questionnaire. The 30 evaluable patients were primarily white (90%) and had a mean age of 58.1 years. Standard pooled variances t test showed that curcumin reduced RDS at end of treatment compared to placebo (mean RDS =2.6 vs. 3.4; P =0.008). Fisher’s exact test revealed that fewer curcumin-treated patients had moist desquamation (28.6% vs. 87.5%; P =0.002). No significant differences were observed between arms for demographics, compliance, radiation skin dose, redness, pain or symptoms. In conclusion, oral curcumin, 6.0 g daily during radiotherapy, reduced the severity of radiation dermatitis in breast cancer patients. PMID:23745991

Surfactant Protein-C Promoter Variants Associated with Neonatal Respiratory Distress Syndrome Reduce Transcription

PubMed Central

Wambach, Jennifer A.; Yang, Ping; Wegner, Daniel J.; An, Ping; Hackett, Brian P.; Cole, F. S.; Hamvas, Aaron

2010-01-01

Dominant mutations in coding regions of the surfactant protein-C gene (SFTPC) cause respiratory distress syndrome (RDS) in infants. However, the contribution of variants in noncoding regions of SFTPC to pulmonary phenotypes is unknown. Using a case-control group of infants ≥34 weeks gestation (n=538), we used complete resequencing of SFTPC and its promoter, genotyping, and logistic regression to identify 80 single nucleotide polymorphisms (SNPs). Three promoter SNPs were statistically associated with neonatal RDS among European descent infants. To assess the transcriptional effects of these three promoter SNPs, we selectively mutated the SFTPC promoter and performed transient transfection using MLE-15 cells and a firefly luciferase reporter vector. Each promoter SNP decreased SFTPC transcription. The combination of two variants in high linkage dysequilibrium also decreased SFTPC transcription. In silico evaluation of transcription factor binding demonstrated that the rare allele at g.-1167 disrupts a SOX (SRY-related high mobility group box) consensus motif and introduces a GATA-1 site, at g.-2385 removes a MZF-1 (myeloid zinc finger) binding site, and at g.-1647 removes a potential methylation site. This combined statistical, in vitro, and in silico approach suggests that reduced SFTPC transcription contributes to the genetic risk for neonatal RDS in developmentally susceptible infants. PMID:20539253

Impact of a fatigue management in work programme on meeting work demands of individuals with rheumatic diseases: A pilot study.

PubMed

McCormack, Róisín C; O'Shea, Finbar; Doran, Michele; Connolly, Deirdre

2018-03-25

Work disability and job loss are serious consequences of rheumatic diseases (RDs), and fatigue is a symptom of RDs commonly reported to have an impact on work performance. A FAtigue ManagEment in Work (FAME-W) programme was developed to facilitate the self-management of fatigue in work. The present pilot study explored if FAME-W could facilitate individuals with RDs to manage fatigue in work and improve their ability to meet work demands. Twenty-seven individuals with a variety of rheumatic diagnoses completed a 4-week, 2-h occupational therapy-led self-management programme. Each week focused on fatigue-related topics, including fatigue and activity management, pain management and joint protection, mental well-being, effective communication with employers and work colleagues, and employment legislation. Individual workplace ergonomic assessments were also offered. Study measures (work function, fatigue, pain, mood and self-efficacy) were completed prior to starting FAME-W, immediately post-intervention and 12 weeks post-intervention. Participants (56% male) had a mean age of 43 years. No significant improvements were observed immediately post-programme. However, at the 12-week follow-up, significant improvements were reported in meeting work demands (scheduling [p = 0.046], output [p = 0.002], physical [p = 0.003], mental [p = 0.016]), fatigue [p = 0.001], pain [p = 0.01], anxiety [p = 0.001], depression [p < 0.001], self-efficacy [p < 0.001] and Arthritis Impact Measurement Scales 2-Short Form (physical: p = 0.005; symptoms: p = 0.010; affect: p = 0.010; social: p = 0.001). Significant improvements were reported in participants' ability to meet various demands of their work 3 months post-FAME-W. These findings suggest that FAME-W has the potential to assist individuals with RDs to meet the demands of their work, although further research is required to test the effectiveness of this intervention. Copyright © 2018 John Wiley & Sons, Ltd.

Using the Neuroadaptagen KB200z™ to Ameliorate Terrifying, Lucid Nightmares in RDS Patients: the Role of Enhanced, Brain-Reward, Functional Connectivity and Dopaminergic Homeostasis

PubMed Central

McLaughlin, Thomas; Blum, Kenneth; Oscar-Berman, Marlene; Febo, Marcelo; Demetrovics, Zsolt; Agan, Gozde; Fratantonio, James; Gold, Mark S.

2015-01-01

Background Lucid Dreams are a form of dream life, during which the dreamer may be aware that he/she is dreaming, can stop/re-start the dreams, depending on the pleasantness or unpleasant nature of the dream, and experiences the dream as if he/she were fully awake. Depending on their content, they may be pleasant, un-pleasant or terrifying, at least in the context of patients, who also exhibit characteristics of Reward Deficiency Syndrome (RDS) and Posttraumatic Stress Disorder (PTSD). Case Series We present eight clinical cases, with known substance abuse, childhood abuse and diagnosed PTSD/RDS. The administration of a putative dopamine agonist, KB200Z™, was associated with the elimination of unpleasant and/or terrifying, lucid dreams in 87.5% of the cases presented, whereas one very heavy cocaine abuser showed a minimal response. These results required the continuous use of this nutraceutical. The lucid dreams themselves were distinguishable from typical, PTSD nightmares insofar as their content did not appear to reflect a symbolic rendition of an originally-experienced, historical trauma. Each of the cases was diagnosed with a form of RDS, i.e., ADHD, ADD, and/or Tourette’s syndrome. They all also suffered from some form of Post-Traumatic-Stress-Disorder (PTSD) and other psychiatric diagnoses as well. Conclusion The reduction or elimination of terrifying Lucid Dreams seemed to be dependent on KB220Z, whereby voluntary stopping of the agent results in reinstatement of the terrifying non-pleasant nature of the dreams. Following more required research on a much larger population we anticipate confirmation of these seemingly interesting observations. If these results in a small number of patients are indeed confirmed we may have found a frontline solution to a very perplexing and complicated symptom known as lucid dreams. PMID:26065033

Dental age assessment of southern Chinese using the United Kingdom Caucasian reference dataset.

PubMed

Jayaraman, Jayakumar; Roberts, Graham J; King, Nigel M; Wong, Hai Ming

2012-03-10

Dental age assessment is one the most accurate methods for estimating the age of an unknown person. Demirjian's dataset on a French-Canadian population has been widely tested for its applicability on various ethnic groups including southern Chinese. Following inaccurate results from these studies, investigators are now confronted with using alternate datasets for comparison. Testing the applicability of other reliable datasets which result in accurate findings might limit the need to develop population specific standards. Recently, a Reference Data Set (RDS) similar to the Demirjian was prepared in the United Kingdom (UK) and has been subsequently validated. The advantages of the UK Caucasian RDS includes versatility from including both the maxillary and mandibular dentitions, involvement of a wide age group of subjects for evaluation and the possibility of precise age estimation with the mathematical technique of meta-analysis. The aim of this study was to evaluate the applicability of the United Kingdom Caucasian RDS on southern Chinese subjects. Dental panoramic tomographs (DPT) of 266 subjects (133 males and 133 females) aged 2-21 years that were previously taken for clinical diagnostic purposes were selected and scored by a single calibrated examiner based on Demirjian's classification of tooth developmental stages (A-H). The ages corresponding to each stage of tooth developmental stage were obtained from the UK dataset. Intra-examiner reproducibility was tested and the Cohen kappa (0.88) showed that the level of agreement was 'almost perfect'. The estimated dental age was then compared with the chronological age using a paired t-test, with statistical significance set at p<0.01. The results showed that the UK dataset, underestimated the age of southern Chinese subjects by 0.24 years but the results were not statistically significant. In conclusion, the UK Caucasian RDS may not be suitable for estimating the age of southern Chinese subjects and there is a need for an ethnic specific reference dataset for southern Chinese. Copyright © 2011. Published by Elsevier Ireland Ltd.

Extreme interplanetary rotational discontinuities at 1 AU

NASA Astrophysics Data System (ADS)

Lepping, R. P.; Wu, C.-C.

2005-11-01

This study is concerned with the identification and description of a special subset of four Wind interplanetary rotational discontinuities (from an earlier study of 134 directional discontinuities by Lepping et al. (2003)) with some "extreme" characteristics, in the sense that every case has (1) an almost planar current sheet surface, (2) a very large discontinuity angle (ω), (3) at least moderately strong normal field components (>0.8 nT), and (4) the overall set has a very broad range of transition layer thicknesses, with one being as thick as 50 RE and another at the other extreme being 1.6 RE, most being much thicker than are usually studied. Each example has a well-determined surface normal (n) according to minimum variance analysis and corroborated via time delay checking of the discontinuity with observations at IMP 8 by employing the local surface planarity. From the variance analyses, most of these cases had unusually large ratios of intermediate-to-minimum eigenvalues (λI/λmin), being on average 32 for three cases (with a fourth being much larger), indicating compact current sheet transition zones, another (the fifth) extreme property. For many years there has been a controversy as to the relative distribution of rotational (RDs) to tangential discontinuities (TDs) in the solar wind at 1 AU (and elsewhere, such as between the Sun and Earth), even to the point where some authors have suggested that RDs with large ∣Bn∣s are probably not generated or, if generated, are unstable and therefore very rare. Some of this disagreement apparently has been due to the different selection criteria used, e.g., some allowed eigenvalue ratios (λI/λmin) to be almost an order of magnitude lower than 32 in estimating n, usually introducing unacceptable error in n and therefore also in ∣Bn∣. However, we suggest that RDs may not be so rare at 1 AU, but good quality cases (where ∣Bn∣ confidently exceeds the error in ∣Bn∣) appear to be uncommon, and further, cases of large ∣Bn∣ may indeed be rare. Finally, the issue of estimating the number of RDs-to-TDs was revisited using the full 134 events of the original Lepping et al. (2003) study (which utilized the RDs' propagation speeds for this estimation, an unconventional approach) but now by considering only normal field components, the more conventional approach. This resulted in slightly different conclusions, depending on specific assumptions used, making the unconventional approach suspect.

The pooling of manpower and resources through the establishment of European reference networks and rare disease patient registries is a necessary area of collaboration for rare renal disorders.

PubMed

Parker, Samantha

2014-09-01

This review aims to provide guidance on emerging concepts and policy related to European reference networks (ERNs) for rare diseases (RDs) and the development and management of RD patient registries. A major problem facing many RDs including rare renal disorders is that patients do not have a specialist centre that they can attend where clinicians, working as a multidisciplinary team, are experts in the particular disease. Furthermore, for most RDs, no single centre, and in many cases no single country, has sufficient numbers of patients and resources to fully understand the natural history or to conduct clinical and translational research. Therefore, the pooling of manpower and resources through the establishment of ERN and RD patient registries is a common and necessary area of collaboration. The concept of European networks for RDs dates back to the early 2000s and the Commission launch of a call for European pilot reference networks for RDs. These networks of expert centres have been brought together through the desire for further knowledge and innovation in RD areas. Networks demand a holistic approach and long-term vision with close collaboration between clinicians, diagnostic laboratories, scientists, patients and their families. The development of legal measures for ERNs is in progress at the Commission and these networks will be a shared responsibility of the Commission and member states. In the context of ERNs, an essential activity is the patient registries. Patient registries are organized databases where patient information, including demographic, medical and family history, are collected, stored and available for retrieval via standardized and secure methods. Patient registries are increasingly recognized as crucial tools for RD research for which international collaboration is absolutely essential to understand the pathogenesis of rare genotypes, achieve a unified collection of phenotypic data, foster natural history studies providing the foundation for successful orphan drug development, facilitate studies to identify appropriate clinical endpoints or biomarkers, identify participants for research and clinical trials and support discussions with regulators including the safety and efficacy evaluation of potential therapies. Furthermore, patient registries are often used as part of regulatory decisions and post-marketing surveillance requirements. Data can be entered into a registry by patients, clinicians, researchers or directly imported from patient's health records. The major concern in maintaining the dynamic of these networks and registries is sustainability, as the infrastructures and coordination have a cost. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Mortality-based Quantification of Injury Severity for Frequently Occurring Motor Vehicle Crash Injuries

PubMed Central

Weaver, Ashley A.; Barnard, Ryan T.; Kilgo, Patrick D.; Martin, R. Shayn; Stitzel, Joel D.

2013-01-01

The study purpose was to develop mortality-based metrics of injury severity for frequent motor vehicle crash (MVC) injuries. Injury severity was quantified with mortality-based metrics for 240 injuries comprising the top 95% most frequently occurring AIS 2+ injuries in the National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) 2000–2011. Mortality risk ratios (MRRs) were computed by dividing the number of deaths by occurrences for each of the 240 injuries using National Trauma Data Bank Research Data System (NTDB-RDS) MVC cases. MRRMAIS was computed using only patients with a maximum AIS (MAIS) equal to the AIS severity of a given injury. Each injury had an associated MRR and MRRMAIS which ranged from zero (0% mortality representing low severity) to one (100% or universal mortality representing high severity). Injuries with higher MRR and MRRMAIS values are considered more severe because they resulted in a greater proportion of deaths among injured patients. The results illustrated an overall positive trend between AIS severity and the MRR and MRRMAIS values as expected, but showed large variations in MRR and MRRMAIS for some injuries of the same AIS severity. Mortality differences up to 83% (MRR) and 54% (MRRMAIS) were observed for injuries of the same AIS severity. The MRR-based measures of injury severity indicate that some lower AIS severity injuries may result in as many deaths as higher AIS severity injuries. This data-driven determination of injury severity using MRR and MRRMAIS provides a supplement or an alternative to AIS severity classification. PMID:24406961

Mortality-based Quantification of Injury Severity for Frequently Occurring Motor Vehicle Crash Injuries.

PubMed

Weaver, Ashley A; Barnard, Ryan T; Kilgo, Patrick D; Martin, R Shayn; Stitzel, Joel D

The study purpose was to develop mortality-based metrics of injury severity for frequent motor vehicle crash (MVC) injuries. Injury severity was quantified with mortality-based metrics for 240 injuries comprising the top 95% most frequently occurring AIS 2+ injuries in the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) 2000-2011. Mortality risk ratios (MRRs) were computed by dividing the number of deaths by occurrences for each of the 240 injuries using National Trauma Data Bank Research Data System (NTDB-RDS) MVC cases. MRRMAIS was computed using only patients with a maximum AIS (MAIS) equal to the AIS severity of a given injury. Each injury had an associated MRR and MRRMAIS which ranged from zero (0% mortality representing low severity) to one (100% or universal mortality representing high severity). Injuries with higher MRR and MRRMAIS values are considered more severe because they resulted in a greater proportion of deaths among injured patients. The results illustrated an overall positive trend between AIS severity and the MRR and MRRMAIS values as expected, but showed large variations in MRR and MRRMAIS for some injuries of the same AIS severity. Mortality differences up to 83% (MRR) and 54% (MRRMAIS) were observed for injuries of the same AIS severity. The MRR-based measures of injury severity indicate that some lower AIS severity injuries may result in as many deaths as higher AIS severity injuries. This data-driven determination of injury severity using MRR and MRRMAIS provides a supplement or an alternative to AIS severity classification.

High-speed real-time animated displays on the ADAGE (trademark) RDS 3000 raster graphics system

NASA Technical Reports Server (NTRS)

Kahlbaum, William M., Jr.; Ownbey, Katrina L.

1989-01-01

Techniques which may be used to increase the animation update rate of real-time computer raster graphic displays are discussed. They were developed on the ADAGE RDS 3000 graphic system in support of the Advanced Concepts Simulator at the NASA Langley Research Center. These techniques involve the use of a special purpose parallel processor, for high-speed character generation. The description of the parallel processor includes the Barrel Shifter which is part of the hardware and is the key to the high-speed character rendition. The final result of this total effort was a fourfold increase in the update rate of an existing primary flight display from 4 to 16 frames per second.

Two types of rate-determining step in chemical and biochemical processes.

PubMed Central

Yagisawa, S

1989-01-01

Close examination of the concept of the rate-determining step (RDS) shows that there are two types of RDS depending on the definition of 'rate'. One is represented by the highest peak of the free-energy diagram of consecutive reactions and holds true where the rate is defined in terms of the concentration of the first reactant. The other is represented by the peak showing the maximum free-energy difference, where the free-energy difference is the height of a peak measured from the bottom of any preceding troughs, where the definition of the rate is in terms of the total reactant concentration including intermediates. There are no criteria a priori for selecting one of them. PMID:2597141

[Biophysical models in investigations of exogenous surfactant activities on the surface tension and their theurapeutic effectiveness].

PubMed

Todorov, R; Iordanova, A; Georgiev, G A; Petkova, Kh; Stoimenova, E; Georgieva, R; Khristova, E; Vasiliev, Kh; Lalchev, Z

2007-01-01

Surfactant therapy leads to significant clinical improvement in infants at risk for, or having, respiratory distress syndrome (RDS). The development of exogenous surfactant (ES) as a therapy for neonatal respiratory disorders was a significant advance in neonatal intensive care that has led to a decrease in neonatal mortality. Two broad categories of surfactants are available for exogenous therapy: surfactants derived from animal sources or 'natural' surfactants; and synthetic surfactants. The physical properties of natural and synthetic surfactants have been studied using techniques such as the Wilhelmy surface balance and the bilayer black film (BBF) method. Here we report some data from a comparative study of ES (Exosurf, Survanta, Curosurf and Alveofact) and clinical samples of tracheal aspirate (TA) of newborns with RDS treated with Curosurf. Measured interfacial physico-chemical parameters prove "better" properties in vitro of the surfactant proteins (SP-B and SP-C) containing preparations Curosurf and Alveofact. Their properties are similar, Alveofact showing a higher surface tension lowering capacity under dynamic conditions. A compendious comparison of results for dynamic surface properties of monolayers of TA from newborns treated with Curosurf with data for newborns treated with Exosurf is presented. Both ES yield the desired lowering of the surface tension during cyclic film compression, being larger after treatment with Curosurf. Observations concerning the properties of BFF of ES (dependence on surfactant concentration, adsorption time, film drainage time and BFF formation time) are also reported and discussed.

A novel mutation (ASn244Lys) in the peripherin/RDS gene causing autosomal dominant retinitis pigmentosa associated with bull's eye maculopathy detected by nonradioisotopic SSCP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kikawa, Emi; Nakazawa, Mitsuru; Chida, Yasushi

1994-03-01

Retinitis pigmentosa (RP) is characterized by night blindness, an eventual loss of visual field, a diminished response on the electroretinogram, and pigmentary retinal degeneration. These features are primarily explained by the degeneration of photoreceptors. The recent development of the molecular genetic approach has enabled the identification of genes responsible for parts of autosomal dominant RP (ADRP). Rhodopsin and peripherin/RDS genes, in particular, have been successfully shown to cosegregate with ADRP. The authors, therefore, screened 42 unrelated Japanese patients with ADRP to search for mutations in the peripherin/RDS gene. The method we employed for screening was a nonradioisotopic modification of single-strandmore » conformation polymorphism. Among 42 unrelated patients with ADRP, the DNA from one patient (SY) showed an abnormal pattern in exon 2 on SSCP. The DNA fragments were then amplified from affected and nonaffected members of the same family as SY. The alteration in the DNA sequence that was commonly found in the affected members of the family was identified as a heterozygous transversional change of C to A at the third nucleotide in codon 244, resulting in the amino acid replacement of asparagine residue with lysine residue. None of unaffected family members or 30 normal control individuals had this alteration.« less

Supporting public involvement in research design and grant development: a case study of a public involvement award scheme managed by a National Institute for Health Research (NIHR) Research Design Service (RDS).

PubMed

Boote, Jonathan D; Twiddy, Maureen; Baird, Wendy; Birks, Yvonne; Clarke, Clare; Beever, Daniel

2015-10-01

It is good practice for the public to be involved in developing health research. Resources should be available for researchers to fund the involvement of the public in the development of their grants. To describe a funding award scheme to support public involvement in grant development, managed by an NIHR Research Design Service (RDS). Case examples of how the award contributed to successful grant applications and findings from a recent evaluation of the scheme are presented. A case study of resource provision to support public involvement activities in one region of England. University and NHS-based researchers, and members of the public. Between 2009 and 2012, the RDS approved 45 public involvement funding awards (totalling nearly £19,000). These awards contributed to 27 submitted applications at the time of writing, of which 11 were successful (totalling over £7.5 million). The evaluation revealed difficulties encountered by some researchers when involving the public in grant development, which led to suggestions about how the scheme could be improved. This award scheme represents an efficient method of providing researchers with resources to involve the public in grant development and would appear to represent good value for money. © 2013 John Wiley & Sons Ltd.

Entry-level dietitians' salaries and benefits: comparisons with those of other selected health care professionals.

PubMed

Loushine, S K; Vaden, A G

1985-10-01

Data on salaries and fringe benefits of entry-level hospital dietitians were provided by surveys sent to personnel administrators in seven Midwestern states. In September 1982, the annual mean salary offered to dietitians awaiting registration was +16,472, whereas that for entry-level registered dietitians (R.D.s) was +17,250. In the smallest hospitals, annual mean salaries for R.D.s were lowest; non-metropolitan salaries were 2.8% lower than the metropolitan salaries. The salaries of entry-level R.D.s increased 54% from 1977 to 1982, while the Consumer Price Index (CPl), North Central, increased 59.7%. Salaries for selected entry-level health professionals ranked in decreasing order as follows: pharmacist, physical therapist, occupational therapist, social worker, staff nurse, dietitian, medical technologist, and respiratory therapist. Nationally, the entry-level dietitian's mean annual salary was +630 higher than that of the Midwestern dietitian. The increase in the national CPl from 1977 to 1982 was 57%, while the increase in the dietitian's salary was 48%. Leave time generally included 12 sick days, 2 weeks' vacation, 6 holidays, and 3 personal days per year. Employers contribute various amounts to life, health, and dental insurance costs. Discounts often were permitted on various hospital services. More than 80% of the hospitals surveyed provided some reimbursement for continuing education, and 74% permitted educational leaves of absence.

Consequences of childhood reading difficulties and behaviour problems for educational achievement and employment in early adulthood.

PubMed

Smart, Diana; Youssef, George J; Sanson, Ann; Prior, Margot; Toumbourou, John W; Olsson, Craig A

2017-06-01

Reading difficulties (RDs) and behaviour problems (BPs) are two common childhood problems that have a high degree of stability and often negatively affect well-being in both the short and longer terms. The study aimed to shed light on the unique and joint consequences of these two childhood problems for educational and occupational outcomes in early adulthood. Data were drawn from a life-course longitudinal study of psychosocial development, the Australian Temperament Project. Parent and teacher reports and a standard reading test were used to define four groups of children at 7-8 years: RDs only; BPs only; both problems; and neither problem. These groups were followed forward to ascertain educational attainment and employment status at 19-20 and 23-24 years. Each childhood problem was a unique risk for poorer educational and occupational outcomes, with co-occurring problems significantly increasing the risk of poorer educational outcomes. Further analyses revealed that the effects of childhood BPs on occupational status were mediated by secondary school non-completion, but childhood RDs were not. The findings point to the importance of screening and early intervention to prevent or minimize the development of these two childhood problems, as well as continuing to support vulnerable children to increase their likelihood of secondary school completion. © 2017 The British Psychological Society.

Comparison of Clinical Efficacy of Newfactan® versus Surfacten® for the Treatment of Respiratory Distress Syndrome in the Newborn Infants

PubMed Central

Choi, Chang Won; Hwang, Jong Hee; Yoo, Eun Jung; Kim, Kyung Ah; Koh, Sun Young; Lee, Yeon Kyung; Shim, Jae Won; Lee, Eun Kyung; Chang, Wook; Kim, Sung Shin; Chang, Yun Sil; Shin, Son Moon

2005-01-01

Newfactan® is a domestically developed, bovine lung-derived, semi-synthetic surfactant. The aim of this study was to compare the clinical efficacy of Newfactan® with that of Surfacten® in the treatment of respiratory distress syndrome (RDS). Newfactan® or Surfacten® was randomly allocated to 492 newborn infants who were diagnosed as RDS and required surfactant instillation in four participating hospitals. The comparisons were made individually in two subsets of infants by birth weight (<1,500 g group [n=253] and ≥1,500 g group [n=239]). Short-term responses to surfactant and acute complications, such as the total doses of surfactant instilled, response type, extubation rate, ventilator settings, changes in respiratory parameters, air leak, patent ductus arteriosus, pulmonary hemorrhage, and intraventricular hemorrhage, and mortality during the 96 hr after surfactant instillation were measured. Long-term outcome and complications, such as total duration of intubation, bronchopulmonary dysplasia and periventricular leukomalacia, and ultimate mortality were measured. There were no significant differences in demographic and perinatal variables, short-term responses to surfactant and acute complications, and long-term outcome and complications between Newfactan® and Surfacten® in both birth weight groups. We concluded that Newfactan® was comparable to Surfacten® in the clinical efficacy in the treatment of RDS in both birth weight groups. PMID:16100449

Dietary Slowly Digestible Starch Triggers the Gut-Brain Axis in Obese Rats with Accompanied Reduced Food Intake.

PubMed

Hasek, Like Y; Phillips, Robert J; Zhang, Genyi; Kinzig, Kimberly P; Kim, Choon Young; Powley, Terry L; Hamaker, Bruce R

2018-03-01

Slowly digestible starch (SDS), as a functional carbohydrate providing a slow and sustained glucose release, may be able to modulate food intake through activation of the gut-brain axis. Diet-induced obese rats were used to test the effect on feeding behavior of high-fat (HF) diets containing an SDS, fabricated to digest into the ileum, as compared to rapidly digestible starch (RDS). Ingestion of the HF-SDS diet over an 11-week period reduced daily food intake, through smaller meal size, to the same level as a lean body control group, while the group consuming the HF-RDS diet remained at a high food intake. Expression levels (mRNA) of the hypothalamic orexigenic neuropeptide Y (NPY) and Agouti-related peptide (AgRP) were significantly reduced, and the anorexigenic corticotropin-releasing hormone (CRH) was increased, in the HF-SDS fed group compared to the HF-RDS group, and to the level of the lean control group. SDS with digestion into the ileum reduced daily food intake and paralleled suppressed expression of appetite-stimulating neuropeptide genes associated with the gut-brain axis. This novel finding suggests further exploration involving a clinical study and potential development of SDS-based functional foods as an approach to obesity control. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Is violence associated with increased risk behavior among MSM? Evidence from a population-based survey conducted across nine cities in Central America.

PubMed

Wheeler, Jennifer; Anfinson, Katherine; Valvert, Dennis; Lungo, Susana

2014-01-01

There is a dearth of research examining the linkages between violence and HIV risk behavior among men who have sex with men (MSM), including those who identify as transgender women (TW), particularly in Central America where violence is widespread. In this paper, we use population-based survey results to independently examine the correlations between physical, emotional and sexual violence and HIV risk behavior among MSM populations in five countries in Central America. As part of USAID's Combination Prevention for HIV program in Central America, PASMO conducted population based surveys using respondent-driven sampling (RDS) in nine cities in Guatemala, El Salvador, Nicaragua, Costa Rica, and Panama. Initial seeds were recruited using the following criteria: individuals who represented subgroups of MSM by self-identification (homosexual vs. heterosexual or bisexual vs. transgender), social economic strata, and by sex work practices. This study examines the association between violence and 1) HIV risk behaviors relevant to the study populations; 2) protective behaviors; and 3) reported STIs. Individualized RDS estimator weights for each outcome variable were calculated using RDSAT software, and logistic regression analysis was used to determine associations between different forms of violence and the outcome variables. MSM who experienced physical violence were more likely to be engaged in transactional sex (OR: 1.76 [1.42-2.18]), have multiple partners in the past 30 days (OR: 1.37 [1.09-1.71]), and have engaged in sex under the influence of alcohol or drugs (OR: 1.51 [1.24-1.83]). Both physical violence and psychological/verbal violence were also associated with reporting STI symptoms or diagnosis within the past 12 months (OR: 1.72 [1.34-2.21] and 1.80 [1.45-2.23]). The effects of violence on the outcomes were observed after controlling for other risk factors. Transgender women were 3.9 times more likely to report engaging in transactional sex. Respondents who were heterosexual, bisexual, or transgender were also more likely to both report multiple partnerships (OR: 1.44 [1.07-1.96], 1.99 [1.67-2.38], 1.79 [1.37-2.33], respectively) and more likely to report engaging in sex under the influence of alcohol or drugs (OR: 1.52 [1.15-2.01], 1.38 [1.17-1.63], 1.47 [1.16-1.87], respectively), as compared to those identifying as homosexual. Violence experienced by MSM and TW is widespread in Central America. The experience of violence is shown in this study to be independently associated with risk behaviors for HIV infections. Further research and studies are needed to identify the effects violence has on HIV risk behavior among this under-researched population to improve targeted HIV prevention interventions.

Visceroptosis and the Ehlers-Danlos Syndrome.

PubMed

Kucera, Stephen; Sullivan, Stephen N

2017-11-08

The case of a patient with visceroptosis and Ehlers-Danlos syndrome hypermobility type (RDS-HT) is reported here. The literature on this unusual but probably under-recognized complication is reviewed.

Neonatal respiratory distress syndrome

MedlinePlus

Hyaline membrane disease (HMD); Infant respiratory distress syndrome; Respiratory distress syndrome in infants; RDS - infants ... improves slowly after that. Some infants with severe respiratory distress syndrome will die. This most often occurs ...

Factors associated with history of drug use among female sex workers (FSW) in a high HIV prevalence state of India.

PubMed

Medhi, Gajendra Kumar; Mahanta, Jagadish; Kermode, Michelle; Paranjape, Ramesh S; Adhikary, Rajatashuvra; Phukan, Sanjib Kumar; Ngully, P

2012-04-05

The intersection between illicit drug use and female commercial sex work has been identified as an important factor responsible for rising HIV prevalence among female sex workers (FSW) in several northeastern states of India. But, little is know about the factors associated with the use of drugs among FSWs in this region. The objective of the paper was to describe the factors associated with history of drug use among FSWs in Dimapur, an important commercial hub of Nagaland, which is a high HIV prevalence state of India. FSWs were recruited using respondent driven sampling (RDS), and were interviewed to collect data on socio-demographic characteristics and HIV risk behaviours. Biological samples were tested for HIV, syphilis gonorrhea and Chlamydia. Logistic regression analysis was performed to identify factors associated with drug use. Among the 426 FSWs in the study, about 25% (n = 107) reported having ever used illicit drugs. Among 107 illicit drug users, 83 (77.6%) were non-injecting and 24 (22.4%) were injecting drug users. Drug-using FSWs were significantly more likely to test positive for one or more STIs (59% vs. 33.5%), active syphilis (27.1% vs. 11.4%) and Chlamydia infection (30% vs. 19.9%) compared to their non-drug using peers. Drug-using FSWs were also significantly more likely to be currently married, widowed or separated compared with non-drug-using FSWs. In multiple logistic regression analysis, being an alcohol user, being married, having a larger volume of clients, and having sexual partners who have ever used or shared injecting drugs were found to be independently associated with illicit drug use. Drug-using FSWs were more vulnerable to STIs including HIV compared to their non-drug using peers. Several important factors associated with being an FSW who uses drugs were identified in this study and this knowledge can be used to plan more effectively targeted harm reduction strategies and programs.

Fine genetic mapping of a gene for autosomal recessive retinitis pigmentosa on chromosome 6p21

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shugart, Yin Y.; Banerjee, P.; Knowles, J.A.

1995-08-01

The inherited retinal degenerations known as retinitis pigmentosa (RP) can be caused by mutations at many different loci and can be inherited as an autosomal recessive, autosomal dominant, or X-linked recessive trait. Two forms of autosomal recessive (arRP) have been reported to cosegregate with mutations in the rhodopsin gene and the beta-subunit of rod phosphodiesterase on chromosome 4p. Genetic linkage has been reported on chromosomes 6p and 1q. In a large Dominican family, we reported an arRp gene near the region of the peripherin/RDS gene. Four recombinations were detected between the disease locus and an intragenic marker derived from peripherin/RDS.more » 26 refs., 2 figs., 1 tab.« less

Atherosclerotic renovascular disease among hypertensive adults

PubMed Central

Davis, Ross P.; Pearce, Jeffrey D.; Craven, Timothy E.; Moore, Phillip S.; Edwards, Matthew S.; Godshall, Christopher J.; Hansen, Kimberley J.

2010-01-01

Purpose Ths report describes the change in atherosclerotic renovascular disease (AS-RVD) among hypertensive adults referred for renal duplex sonography (RDS) scan. Methods From Oct 1993 through July 2008, 20,994 patients had RDS at our center. A total of 434 hypertensive patients with two or more RDS exams without intervention comprised the study cohort. Patient demographics (blood pressures, medications, serum creatinine levels, and data from RDS) were collected. Analyses of longitudinal changes in Doppler scan parameters, blood pressures, and renal function were performed by fitting linear growth-curve models. After confirming the linearity of change in Doppler scan parameters among patients with variable number of studies, estimates of mean slopes were calculated using maximum likelihood techniques. For changes in renal function, quadratic growth curves were required to describe longitudinal change. Results A total of 434 subjects (212 men [49%] and 222 women [51%]; mean age, 64.6 ± 12.2 years) provided 1351 studies (mean, 3.2 ± 2.4; range, 2 to 18) for 863 kidneys over a mean follow-up of 34.4 ± 25.1 months. At baseline, 20.6% of kidneys demonstrated hemodynamically significant stenosis. On follow-up, 72 kidneys (9.1%) demonstrated anatomic progression of disease. A total of 54 kidneys (6.9%) progressed to significant stenosis and 18 (2.3%) progressed to occlusion. Controlling for progression of disease, baseline renal artery status demonstrated a strong association with baseline kidney length (P = .0006). Significant annualized change in renal length was observed (cm change/year ± standard error of the mean [SEM]: 0.042 ± 0.011; P = .0002) among both kidneys with and without critical disease at baseline, however, decline in length was significantly greater among kidneys exhibiting progression of renovascular disease (−0.152 ± 0.028 cm/year; comparison of slopes between groups P = .0005). In the absence of progression, the presence or absence of critical renal artery stenosis at baseline did not affect the rate of decline in renal length. Fitted models for the natural log transform of serum creatinine demonstrated a significant increase during follow-up (P < .0001). No association was observed between change in serum creatinine and baseline renovascular disease status, or its progression. Conclusion A total of 32% of hypertensive adults referred for RDS demonstrated hemodynamically significant renal artery stenosis. Regardless of the presence or absence of baseline disease, a small percentage of patients demonstrated anatomic progression of AS-RVD. A total of 9.1% demonstrated anatomic progression and 2.3% progressed to occlusion. Although anatomic progression of AS-RVD was associated with an increased rate of decline in renal length, progression did not predict a decline in excretory renal function. Intervention for AS-RVD should be selective and reserved for strict indications. PMID:19700093

Comparison of the effects of sodium phenobarbital in wild type and humanized constitutive androstane receptor (CAR)/pregnane X receptor (PXR) mice and in cultured mouse, rat and human hepatocytes.

PubMed

Haines, Corinne; Elcombe, Barbara M; Chatham, Lynsey R; Vardy, Audrey; Higgins, Larry G; Elcombe, Clifford R; Lake, Brian G

2018-03-01

Phenobarbital (PB), a constitutive androstane receptor (CAR) activator, produces liver tumours in rodents by a mitogenic mode of action involving CAR activation. In this study, the hepatic effects of sodium phenobarbital (NaPB) were compared in male C57BL/6J wild type (WT) mice and in humanized mice, where both the mouse CAR and pregnane X receptor (PXR) have been replaced by their human counterparts (hCAR/hPXR mice). Investigations were also performed in cultured male C57BL/6J and CD-1 mouse, male Sprague-Dawley rat and male and female human hepatocytes. The treatment of WT and hCAR/hPXR mice with 186-984 ppm NaPB in the diet for 7 days resulted in increased relative liver weight, hypertrophy and induction of cytochrome P450 (CYP) enzyme activities. Treatment with NaPB also produced dose-dependent increases in hepatocyte replicative DNA synthesis (RDS), with the effect being more marked in WT than in hCAR/hPXR mice. While the treatment of cultured C57BL/6J and CD-1 mouse, Sprague-Dawley rat and human hepatocytes with 100 and/or 1000 μM NaPB for 4 days induced CYP enzyme activities, increased RDS was only observed in mouse and rat hepatocytes. However, as a positive control, epidermal growth factor increased RDS in hepatocytes from all three species. In summary, although human hepatocytes are refractory to the mitogenic effects of NaPB, treatment with NaPB induced RDS in vivo in hCAR/hPXR mice, which is presumably due to the human CAR and PXR receptors operating in a mouse hepatocyte regulatory environment. As the response of the hCAR/hPXR mouse to the CAR activator NaPB differs markedly from that of human hepatocytes, the hCAR/hPXR mouse is thus not a suitable animal model for studies on the hepatic effects of nongenotoxic rodent CAR activators. Copyright © 2018 Elsevier B.V. All rights reserved.

Dietetics trends as reflected in various primary research projects, 1995-2011.

PubMed

Rogers, Dick

2012-03-01

At the behest of the Commission on Dietetic Registration (CDR) Workforce Demand Task Force, a retrospective examination and reanalysis of 12 primary research projects (sponsored by CDR and/or the Academy of Nutrition and Dietetics between 1995 and 2011) was undertaken to identify trends in supply of and demand for registered dietitians (RDs) and dietetic technicians, registered (DTRs). The analysis suggests that supply of RDs (and possibly DTRs) lags slightly behind demand-although, in the case of DTRs, that does not necessarily imply that demand is growing (supply was shrinking throughout most of the study period). The population of both groups is aging, and the number of RDs and DTRs reporting expected retirement in the near future is sure to affect supply/demand relationships. Neither group reflects the US population as a whole in terms of either sex or racial/ethnic diversity, and the trend lines in these areas are essentially flat. RD practice is seen to be moving incrementally toward the clinical arena, in inpatient and (increasingly) outpatient settings. The proportion of RDs in clinical long-term-care, as well as in food/nutrition management and consultation/business practice, is decreasing; a longer-term trend away from foodservice is noted. There is small growth in both the prevalence and the compensation of clinical specialists in areas like renal, pediatrics, and weight management at the expense of more general clinical practitioners. In a trend likely related to the increase in clinical practice, RD positions are gradually losing managerial responsibility. DTRs have experienced a similar phenomenon. For almost all RD positions in the clinical arena, registration as an RD is a requirement for employment, suggesting that clinical employment should continue to grow along with the increasing health care demand from an aging population. The DTR credential is not required at similarly high rates. A major supply issue is the relative shortage of DTRs in certain parts of the country, particularly the South. Major effects from the June 2009 inauguration of the Pathway III route to registration as a DTR have been noted. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA nanoparticles results in improved phenotype in a mouse model of retinitis pigmentosa.

PubMed

Cai, Xue; Conley, Shannon M; Nash, Zack; Fliesler, Steven J; Cooper, Mark J; Naash, Muna I

2010-04-01

The purpose of the present study was to test the therapeutic efficiency and safety of compacted-DNA nanoparticle-mediated gene delivery into the subretinal space of a juvenile mouse model of retinitis pigmentosa. Nanoparticles containing the mouse opsin promoter and wild-type mouse Rds gene were injected subretinally into mice carrying a haploinsufficiency mutation in the retinal degeneration slow (rds(+ or -)) gene at postnatal day (P)5 and 22. Control mice were either injected with saline, injected with uncompacted naked plasmid DNA carrying the Rds gene, or remained untreated. Rds mRNA levels peaked at postinjection day 2 to 7 (PI-2 to PI-7) for P5 injections, stabilized at levels 2-fold higher than in uninjected controls for both P5 and P22 injections, and remained elevated at the latest time point examined (PI-120). Rod function (measured by electroretinography) showed modest but statistically significant improvement compared with controls after both P5 and P22 injections. Cone function in nanoparticle-injected eyes reached wild-type levels for both ages of injections, indicating full prevention of cone degeneration. Ultrastructural examination at PI-120 revealed significant improvement in outer segment structures in P5 nanoparticle-injected eyes, while P22 injection had a modest structural improvement. There was no evidence of macrophage activation or induction of IL-6 or TNF-alpha mRNA in P5 or P22 nanoparticle-dosed eyes at either PI-2 or PI-30. Thus, compacted-DNA nanoparticles can efficiently and safely drive gene expression in both mitotic and postmitotic photoreceptors and retard degeneration in this model. These findings, using a clinically relevant treatment paradigm, illustrate the potential for application of nanoparticle-based gene replacement therapy for treatment of human retinal degenerations.-Cai, X., Conley, S. M., Nash, Z., Fliesler, S. J., Cooper, M. J., Naash, M. I. Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA nanoparticles results in improved phenotype in a mouse model of retinitis pigmentosa.

Women's experiences seeking informal sector abortion services in Cape Town, South Africa: a descriptive study.

PubMed

Gerdts, Caitlin; Raifman, Sarah; Daskilewicz, Kristen; Momberg, Mariette; Roberts, Sarah; Harries, Jane

2017-10-02

In settings where abortion is legally restricted, or permitted but not widely accessible, women face significant barriers to abortion access, sometimes leading them to seek services outside legal facilities. The advent of medication abortion has further increased the prevalence of informal sector abortion. This study investigates the reasons for attempting self-induction, methods used, complications, and sources of information about informal sector abortion, and tests a specific recruitment method which could lead to improved estimates of informal sector abortion prevalence among an at-risk population. We recruited women who have sought informal sector abortion services in Cape Town, South Africa using respondent driven sampling (RDS). An initial seed recruiter was responsible for initiating recruitment using a structured coupon system. Participants completed face-to-face questionnaires, which included information about demographics, informal sector abortion seeking, and safe abortion access needs. We enrolled 42 women, nearly one-third of whom reported they were sex workers. Thirty-four women (81%) reported having had one informal sector abortion within the past 5 years, 14% reported having had two, and 5% reported having had three. These women consumed home remedies, herbal mixtures from traditional healers, or tablets from an unregistered provider. Twelve sought additional care for potential warning signs of complications. Privacy and fear of mistreatment at public sector facilities were among the main reported reasons for attempting informal sector abortion. Most women (67%) cited other community members as their source of information about informal sector abortion; posted signs and fliers in public spaces also served as an important source of information. Women are attempting informal sector abortion because they seek privacy and fear mistreatment and stigma in health facilities. Some were unaware how or where to seek formal sector services, or believed the cost was too high. Many informal methods are ineffective and unsafe, leading to potential warning signs of complications and continued pregnancy. Sex workers may be at particular risk of unsafe abortion. Based on these results, it is essential that future studies sample women outside of the formal health sector. The use of innovative sampling methods would greatly improve our knowledge about informal sector abortion in South Africa.

Effect of placenta previa on neonatal respiratory disorders and amniotic lamellar body counts at 36-38weeks of gestation.

PubMed

Tsuda, Hiroyuki; Kotani, Tomomi; Sumigama, Seiji; Mano, Yukio; Hua, Li; Hayakawa, Hiromi; Hayakawa, Masahiro; Sato, Yoshiaki; Kikkawa, Fumitaka

2014-01-01

Pregnancies with placenta previa are significantly associated with preterm delivery and cesarean section. Therefore particular attention should be paid to the incidence of neonatal respiratory disorders in pregnancies with placenta previa. The purpose of this study is to examine the relationship between placenta previa and neonatal respiratory disorders, including respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN), and to evaluate the impact of placenta previa on the amniotic lamellar body count (LBC) values. We analyzed the data from 186 registered elective cesarean cases without fetal or maternal complications at 36-38weeks of gestation. Amniotic fluid samples were analyzed immediately without centrifugation, and the LBC was measured using a platelet channel on the Sysmex XE-2100. RDS was present in four neonates (2.2%) and TTN in 12 neonates (6.5%). The rate of TTN was significantly higher and the LBC values were significantly lower in the placenta previa group than in the control group (P=0.002 and P=0.024). The adjusted odds ratio for neonatal TTN was 7.20 (95% confidence interval: 6.58-7.88) among females with placenta previa. In placenta previa, warning bleeding was a significant factor protecting against neonatal respiratory disorders (P=0.046). Placenta previa in itself is a risk factor for neonatal TTN. When an elective cesarean section is performed in cases with uncomplicated placenta previa, special care should be taken to monitor for neonatal TTN even at 36-38weeks of gestation. © 2013.

[Homöopathisch-phytotherapeutische Behandlung des Reizdarmsyndroms mit Magen-Darm-Entoxin N®: Eine Anwendungsbeobachtung].

PubMed

Märtens, Diane; Range, Natasha; Günnewich, Nils; Gruber, Nicola; Schmidt, Stefan

Hintergrund: In dieser Anwendungsbeobachtung wird zum ersten Mal die Behandlung des Reizdarmsyndroms (RDS) mit einem homöopathisch-phytotherapeutischen Komplexpräparat beschrieben. Methodik: Ziel der 6-wöchigen Therapie mit dem Magen-Darm-Entoxin N® war die Reduzierung der RDS-Symptomatik sowie die Verbesserung der Lebensqualität. Zielkriterien waren die Veränderungen in der Irritable Bowel Syndrome - Severity Scoring System (IBS-SSS) und der Irritable Bowel Syndrome - Quality-of-Life Scale (IBS-QoL). Die Patient/innen (N = 41; Alter 44,0 ± 15,74 Jahre) wurden zu gleichen Teilen in einer Hausarztpraxis (N = 20) und einer Heilpraktikerpraxis (N = 21) rekrutiert. Ergebnisse: Der IBS-QoL-Score verringerte sich signifikant (prä: 35,9 ± 16,3; post: 20,1 ± 13,4; t = 8,504; p < 0,001). Die Effektstärke betrug 1,34 (Cohens d). Der IBS-SSS-Score verringerte sich ebenfalls signifikant (prä: 239,4 ± 83,4; post: 123,7 ± 80,9; t = 7,825; p < 0,001) mit einer Effektstärke von d = 1,24. Die Neben- und Wechselwirkungen waren minimal und signifikante Unterschiede zwischen beiden Praxen wurden nicht gefunden. Schlussfolgerungen: Magen-Darm-Entoxin N® ist eine sichere und sinnvolle Therapieoption bei der Behandlung des RDS. Allerdings sollten randomisierte kontrollierte Studien folgen, um die Spezifizität der Ergebnisse dieser Anwendungsbeobachtung zu stützen. © 2017 S. Karger GmbH, Freiburg.

The Effect of Birth Order on Neonatal Morbidity and Mortality in Very Preterm Twins.

PubMed

Mei-Dan, Elad; Shah, Jyotsna; Lee, Shoo; Shah, Prakesh S; Murphy, Kellie E

2017-07-01

Objective  This retrospective cohort study examined the effect of birth order on neonatal morbidity and mortality in very preterm twins. Study Design  Using 2005 to 2012 data from the Canadian Neonatal Network, very preterm twins born between 24 0/7 and 32 6/7 weeks of gestation were included. Odds of morbidity and mortality of second-born cotwins compared with first-born cotwins were examined by matched-pair analysis. Outcomes were neonatal death, severe brain injury (intraventricular hemorrhage grade 3 or 4 or persistent periventricular echogenicity), bronchopulmonary dysplasia, severe retinopathy of prematurity (ROP) (> stage 2), necrotizing enterocolitis (≥ stage 2), and respiratory distress syndrome (RDS). Multivariable analysis was performed adjusting for confounders. Result  There were 6,636 twins (3,318 pairs) included with a mean gestational age (GA) of 28.9 weeks. A higher rate of small for GA occurred in second-born twins (10 vs. 6%). Mortality was significantly lower for second-born twins (4.3 vs. 5.3%; adjusted odds ratio: 0.75; 95% confidence interval [CI]: 0.59-0.95). RDS (66 vs. 60%; adjusted odds ratio: 1.40; 95% CI: 1.29-1.52) and severe retinopathy (9 vs. 7%; adjusted odds ratio: 1.46; 95% CI: 1.07-2.01) were significantly higher in second-born twins. Conclusion  Thus, while second-born twins had reduced odds of mortality, they also had increased odds of RDS and ROP. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Impact of Registered Dietitian Expertise in Health Guidance for Weight Loss

PubMed Central

Imanaka, Mie; Ando, Masahiko; Kitamura, Tetsuhisa; Kawamura, Takashi

2016-01-01

Background & Objectives Expertise of registered dietitians (RDs) is important for health guidance but has been poorly evaluated. We evaluated the kind of RD expertise that would improve their skills. Design, Setting, Participants, Measurements This study was a post-hoc analysis of our randomized controlled trial, which compared the weight change between participants using the web-based self-disclosure health support and those using the email health support. Healthy men and women aged 35–64 years with a body mass index (BMI) of > = 24.5 kg/m2 were recruited for this study. We evaluated the relationship of RD expertise indicators including the duration of working as an RD, the experience of health counseling, and membership in the Japan Dietetic Association (JDA) with the weight loss of study participants. The primary endpoint was the change in body weight. Comparison of changes in body weight by the RD expertise indicators was evaluated using analysis of covariance. Results A total of 175 participants were eligible for analyses. Changes in body weight were significantly greater when they were supported by the RDs in the routine counseling group than when supported by the RDs in the non-routine counseling group (-1.8 kg versus -0.4 kg, fully adjusted P = 0.0089). Duration of working as an RD and JDA membership did not significantly affect changes in body weight. Conclusions Among some indices of RD experience, the experience of providing routine experience of health counseling was associated with weight loss. PMID:27003943

Radiative neutron capture as a counting technique at pulsed spallation neutron sources: a review of current progress

NASA Astrophysics Data System (ADS)

Schooneveld, E. M.; Pietropaolo, A.; Andreani, C.; Perelli Cippo, E.; Rhodes, N. J.; Senesi, R.; Tardocchi, M.; Gorini, G.

2016-09-01

Neutron scattering techniques are attracting an increasing interest from scientists in various research fields, ranging from physics and chemistry to biology and archaeometry. The success of these neutron scattering applications is stimulated by the development of higher performance instrumentation. The development of new techniques and concepts, including radiative capture based neutron detection, is therefore a key issue to be addressed. Radiative capture based neutron detectors utilize the emission of prompt gamma rays after neutron absorption in a suitable isotope and the detection of those gammas by a photon counter. They can be used as simple counters in the thermal region and (simultaneously) as energy selector and counters for neutrons in the eV energy region. Several years of extensive development have made eV neutron spectrometers operating in the so-called resonance detector spectrometer (RDS) configuration outperform their conventional counterparts. In fact, the VESUVIO spectrometer, a flagship instrument at ISIS serving a continuous user programme for eV inelastic neutron spectroscopy measurements, is operating in the RDS configuration since 2007. In this review, we discuss the physical mechanism underlying the RDS configuration and the development of associated instrumentation. A few successful neutron scattering experiments that utilize the radiative capture counting techniques will be presented together with the potential of this technique for thermal neutron diffraction measurements. We also outline possible improvements and future perspectives for radiative capture based neutron detectors in neutron scattering application at pulsed neutron sources.

Position of the American Dietetic Association: Providing nutrition services for people with developmental disabilities and special health care needs.

PubMed

Van Riper, Cynthia L; Wallace, Lee Shelly

2010-02-01

It is the position of the American Dietetic Association that nutrition services provided by registered dietitians (RDs) and dietetic technicians, registered (DTRs), are essential components of comprehensive care for all people with developmental disabilities and special health care needs. Nutrition services should be provided throughout life in a manner that is interdisciplinary, family-centered, community-based, and culturally competent. People with developmental disabilities and special health care needs frequently have nutrition concerns, including growth alterations (failure to thrive, obesity, or growth retardation), metabolic disorders, poor feeding skills, medication-nutrient interactions, and sometimes partial or total dependence on enteral or parenteral nutrition. Individuals with special needs are also more likely to develop comorbid conditions such as obesity or endocrine disorders that require nutrition interventions. Poor health habits, limited access to services, and long-term use of multiple medications are considered health risk factors. Health maintenance and avoidance of complications can be promoted by timely and cost-effective nutrition interventions. Public policy for individuals with special needs has evolved over time, resulting in a transition from institutional facilities and programs to community living. The expansion of public access to technology and health information on the Internet challenges RDs and DTRs to provide accurate scientific information for those with developmental disabilities and special health care needs. Nationally credentialed RDs and DTRs are best prepared to provide appropriate nutrition information for wellness and quality of life.

A visual analytics approach for pattern-recognition in patient-generated data.

PubMed

Feller, Daniel J; Burgermaster, Marissa; Levine, Matthew E; Smaldone, Arlene; Davidson, Patricia G; Albers, David J; Mamykina, Lena

2018-06-13

To develop and test a visual analytics tool to help clinicians identify systematic and clinically meaningful patterns in patient-generated data (PGD) while decreasing perceived information overload. Participatory design was used to develop Glucolyzer, an interactive tool featuring hierarchical clustering and a heatmap visualization to help registered dietitians (RDs) identify associative patterns between blood glucose levels and per-meal macronutrient composition for individuals with type 2 diabetes (T2DM). Ten RDs participated in a within-subjects experiment to compare Glucolyzer to a static logbook format. For each representation, participants had 25 minutes to examine 1 month of diabetes self-monitoring data captured by an individual with T2DM and identify clinically meaningful patterns. We compared the quality and accuracy of the observations generated using each representation. Participants generated 50% more observations when using Glucolyzer (98) than when using the logbook format (64) without any loss in accuracy (69% accuracy vs 62%, respectively, p = .17). Participants identified more observations that included ingredients other than carbohydrates using Glucolyzer (36% vs 16%, p = .027). Fewer RDs reported feelings of information overload using Glucolyzer compared to the logbook format. Study participants displayed variable acceptance of hierarchical clustering. Visual analytics have the potential to mitigate provider concerns about the volume of self-monitoring data. Glucolyzer helped dietitians identify meaningful patterns in self-monitoring data without incurring perceived information overload. Future studies should assess whether similar tools can support clinicians in personalizing behavioral interventions that improve patient outcomes.

Population Size Estimation of Men Who Have Sex with Men in Tbilisi, Georgia; Multiple Methods and Triangulation of Findings.

PubMed

Sulaberidze, Lela; Mirzazadeh, Ali; Chikovani, Ivdity; Shengelia, Natia; Tsereteli, Nino; Gotsadze, George

2016-01-01

An accurate estimation of the population size of men who have sex with men (MSM) is critical to the success of HIV program planning and to monitoring of the response to epidemic as a whole, but is quite often missing. In this study, our aim was to estimate the population size of MSM in Tbilisi, Georgia and compare it with other estimates in the region. In the absence of a gold standard for estimating the population size of MSM, this study reports a range of methods, including network scale-up, mobile/web apps multiplier, service and unique object multiplier, network-based capture-recapture, Handcock RDS-based and Wisdom of Crowds methods. To apply all these methods, two surveys were conducted: first, a household survey among 1,015 adults from the general population, and second, a respondent driven sample of 210 MSM. We also conducted a literature review of MSM size estimation in Eastern European and Central Asian countries. The median population size of MSM generated from all previously mentioned methods was estimated to be 5,100 (95% Confidence Interval (CI): 3,243~9,088). This corresponds to 1.42% (95%CI: 0.9%~2.53%) of the adult male population in Tbilisi. Our size estimates of the MSM population (1.42% (95%CI: 0.9%~2.53%) of the adult male population in Tbilisi) fall within ranges reported in other Eastern European and Central Asian countries. These estimates can provide valuable information for country level HIV prevention program planning and evaluation. Furthermore, we believe, that our results will narrow the gap in data availability on the estimates of the population size of MSM in the region.

Factors Associated with Loss-to-Follow-Up during Behavioral Interventions and HIV Testing Cohort among Men Who Have Sex with Men in Nanjing, China

PubMed Central

Tang, Weiming; Huan, Xiping; Zhang, Ye; Mahapatra, Tanmay; Li, Jianjun; Liu, Xiaoyan; Mahapatra, Sanchita; Yan, Hongjing; Fu, Gengfeng; Zhao, Jinkou; Gu, Chenghua; Detels, Roger

2015-01-01

Background Behavioral interventions (BIs) remained the cornerstone of HIV prevention in resource-limited settings. One of the major concerns for such efforts is the loss-to-follow-up (LTFU) that threatens almost every HIV control program involving high-risk population groups. Methods To evaluate the factors associated with LTFU during BIs and HIV testing among men who have sex with men (MSM), 410 HIV sero-negatives MSM were recruited using respondent driven sampling (RDS) in Nanjing, China during 2008, they were further followed for 18 months. At baseline and each follow-up visits, each participant was counseled about various HIV risk-reductions BIs at a designated sexually transmitted infection (STI) clinic. Results Among 410 participants recruited at baseline, altogether 221 (53.9%) were LTFU at the 18-month follow-up visit. Overall, 46 participants were found to be positive for syphilis infection at baseline while 13 participants were HIV sero-converted during the follow-up period. Increasing age was less (Adjusted Odds Ratio(aOR) of 0.90, 95% confidence Interval (CI) 0.86–0.94) and official residency of provinces other than Nanjing (AOR of 2.49, 95%CI 1.32–4.71), lower level of education (AOR of 2.01, 95%CI 1.10–3.66) and small social network size (AOR of 1.75, 95%CI 1.09–2.80) were more likely to be associated with higher odds of LTFU. Conclusion To improve retention in the programs for HIV control, counseling and testing among MSM in Nanjing, focused intensified intervention targeting those who were more likely to be LTFU, especially the young, less educated, unofficial residents of Nanjing who had smaller social network size, might be helpful. PMID:25559678

Factors associated with loss-to-follow-up during behavioral interventions and HIV testing cohort among men who have sex with men in Nanjing, China.

PubMed

Tang, Weiming; Huan, Xiping; Zhang, Ye; Mahapatra, Tanmay; Li, Jianjun; Liu, Xiaoyan; Mahapatra, Sanchita; Yan, Hongjing; Fu, Gengfeng; Zhao, Jinkou; Gu, Chenghua; Detels, Roger

2015-01-01

Behavioral interventions (BIs) remained the cornerstone of HIV prevention in resource-limited settings. One of the major concerns for such efforts is the loss-to-follow-up (LTFU) that threatens almost every HIV control program involving high-risk population groups. To evaluate the factors associated with LTFU during BIs and HIV testing among men who have sex with men (MSM), 410 HIV sero-negatives MSM were recruited using respondent driven sampling (RDS) in Nanjing, China during 2008, they were further followed for 18 months. At baseline and each follow-up visits, each participant was counseled about various HIV risk-reductions BIs at a designated sexually transmitted infection (STI) clinic. Among 410 participants recruited at baseline, altogether 221 (53.9%) were LTFU at the 18-month follow-up visit. Overall, 46 participants were found to be positive for syphilis infection at baseline while 13 participants were HIV sero-converted during the follow-up period. Increasing age was less (Adjusted Odds Ratio(aOR) of 0.90, 95% confidence Interval (CI) 0.86-0.94) and official residency of provinces other than Nanjing (AOR of 2.49, 95%CI 1.32-4.71), lower level of education (AOR of 2.01, 95%CI 1.10-3.66) and small social network size (AOR of 1.75, 95%CI 1.09-2.80) were more likely to be associated with higher odds of LTFU. To improve retention in the programs for HIV control, counseling and testing among MSM in Nanjing, focused intensified intervention targeting those who were more likely to be LTFU, especially the young, less educated, unofficial residents of Nanjing who had smaller social network size, might be helpful.

[Characteristics of social supportive network serving the older female sex workers in Qingdao].

PubMed

Xu, Y Q; Li, Y F; Jiang, Z X; Zhang, X J; Yuan, X; Zhang, N; Li, X F; Jiang, B F

2016-02-01

To overview the status of social support on older female sex workers (OFSWs) in Qingdao and to better understand the characteristics of this egocentric social support networks. Ucinet 6 software was used to analyze the characteristics of egocentric social networks which involving 400 OFSWs who were recruited by respondent-driven sampling (RDS) method in Qingdao during March 2014 to June. Structural equation model (SEM) was used for data analysis, fitted test and estimation. A total of 400 OFSWs of Qingdao nominated 1 617 social supportive members, and the average size of egocentric social networks of OFSWs was (4.0 ± 1.5). Among all the alter egos (social support network members of the egos), 613 were female sex workers fellows, accounted for the most important part of all the social ties (37.91%). Characteristics of small size and non-relative relationships were seen more obviously among OFSWs with non-local registration and the ratings of emotional support (4.42±2.38) was significantly lower than the tangible support (5.73 ± 1.69) (P<0.05). Result of the SEM showed that homogeneity, joint strength and the network structure were significantly related to the ratings of average support. The total standard effects of which were 0.110, 0.925 and -0.069 respectively. It seemed that homogeneity can affect the degree of support, both directly and indirectly. OFSWs in Qingdao tended to ask for social support from friends who were also female sex workers. Stronger the joint strength between egos and alters, greater the homogeneity between the two was seen. Tighter relations among the alter egos, higher degree of average social support of the egos were acquired.

HIV prevention and care-seeking behaviour among female sex workers in four cities in India, Kenya, Mozambique and South Africa.

PubMed

Lafort, Yves; Greener, Ross; Roy, Anuradha; Greener, Letitia; Ombidi, Wilkister; Lessitala, Faustino; Haghparast-Bidgoli, Hassan; Beksinska, Mags; Gichangi, Peter; Reza-Paul, Sushena; Smit, Jenni A; Chersich, Matthew; Delva, Wim

2016-10-01

To identify gaps in the use of HIV prevention and care services and commodities for female sex workers, we conducted a baseline cross-sectional survey in four cities, in the context of an implementation research project aiming to improve use of sexual and reproductive health services. Using respondent-driven sampling, 400 sex workers were recruited in Durban, 308 in Tete, 400 in Mombasa and 458 in Mysore and interviewed face-to-face. RDS-adjusted proportions were estimated by nonparametric bootstrapping and compared across cities using post hoc pairwise comparison. Condom use with last client ranged from 88.3% to 96.8%, ever female condom use from 1.6% to 37.9%, HIV testing within the past 6 months from 40.5% to 70.9%, receiving HIV treatment and care from 35.5% to 92.7%, care seeking for last STI from 74.4% to 87.6% and having had at least 10 contacts with a peer educator in the past year from 5.7% to 98.1%. Many of the differences between cities remained statistically significant (P < 0.05) after adjusting for differences in FSWs' socio-demographic characteristics. The use of HIV prevention and care by FSWs is often insufficient and differed greatly between cities. Differences could not be explained by variations in socio-demographic sex worker characteristics. Models to improve use of condoms and HIV prevention and care services should be tailored to the specific context of each site. Programmes at each site must focus on improving availability and uptake of those services that are currently least used. © 2016 John Wiley & Sons Ltd.

Saxton Transportation Operations Laboratory : driving future highways

DOT National Transportation Integrated Search

2017-01-01

The Saxton Laboratory is supplementing the Office of Operations R&Ds connected automation research program, which includes an initial focus on applications that use longitudinal control, with active driver engagement and advisory information, to i...

TGIS, TIG, Program Development, Transportation & Public Facilities, State

Science.gov Websites

accessible, accurate, and controlled inventory of public roadway features and linear coordinates for the Roadway Data System (RDS) network (Alaska DOT&PF's Linear Reference System or LRS) to meet Federal and

78 FR 55292 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-10

... CFR Part 60, written comments are being accepted concerning the significance of the nominated..., Crooked Run, Lake, Lamb & Raccoon Rds., Willard, 13000803 OREGON Benton County North Palestine Baptist...

The Biomedical Resource Ontology (BRO) to Enable Resource Discovery in Clinical and Translational Research

PubMed Central

Tenenbaum, Jessica D.; Whetzel, Patricia L.; Anderson, Kent; Borromeo, Charles D.; Dinov, Ivo D.; Gabriel, Davera; Kirschner, Beth; Mirel, Barbara; Morris, Tim; Noy, Natasha; Nyulas, Csongor; Rubenson, David; Saxman, Paul R.; Singh, Harpreet; Whelan, Nancy; Wright, Zach; Athey, Brian D.; Becich, Michael J.; Ginsburg, Geoffrey S.; Musen, Mark A.; Smith, Kevin A.; Tarantal, Alice F.; Rubin, Daniel L; Lyster, Peter

2010-01-01

The biomedical research community relies on a diverse set of resources, both within their own institutions and at other research centers. In addition, an increasing number of shared electronic resources have been developed. Without effective means to locate and query these resources, it is challenging, if not impossible, for investigators to be aware of the myriad resources available, or to effectively perform resource discovery when the need arises. In this paper, we describe the development and use of the Biomedical Resource Ontology (BRO) to enable semantic annotation and discovery of biomedical resources. We also describe the Resource Discovery System (RDS) which is a federated, inter-institutional pilot project that uses the BRO to facilitate resource discovery on the Internet. Through the RDS framework and its associated Biositemaps infrastructure, the BRO facilitates semantic search and discovery of biomedical resources, breaking down barriers and streamlining scientific research that will improve human health. PMID:20955817

Arnold tongues in a billiard problem in nonlinear and nonequilibrium systems

NASA Astrophysics Data System (ADS)

Miyaji, Tomoyuki

2017-02-01

We study a billiard problem in nonlinear and nonequilibrium systems. This is motivated by the motions of a traveling spot in a reaction-diffusion system (RDS) in a rectangular domain. We consider a four-dimensional dynamical system, defined by ordinary differential equations. This was first derived by S.-I. Ei et al. (2006), based on a reduced system on the center manifold in a neighborhood of a pitchfork bifurcation of a stationary spot for the RDS. In contrast to the classical billiard problem, this defines a dynamical system that is dissipative rather than conservative, and has an attractor. According to previous numerical studies, the attractor of the system changes depending on parameters such as the aspect ratio of the domain. It may be periodic, quasi-periodic, or chaotic. In this paper, we elucidate that it results from parameters crossing Arnold tongues and that the organizing center is a Hopf-Hopf bifurcation of the trivial equilibrium.

Sorption of Cesium on smectite-rich clays from the Bohemian Massif (Czech Republic) and their mixtures with sand.

PubMed

Vejsada, J; Jelínek, E; Randa, Z; Hradil, D; Prikryl, R

2005-01-01

Sorption is an important process for the transport of radionuclides through backfill materials in a radioactive waste underground repository. Within this study, sorption of Cs on selected Czech clay materials and their mixtures with sand was investigated by batch tests. The experiments were performed under oxic conditions at 25 degrees C. Synthetic groundwater as a liquid phase and unconditioned clays (as they were provided by their producer) were used to reach the natural conditions as close as possible. Distribution ratios (Rds) of Cs for all selected clays rise with increase of the clay fraction in clay/sand mixtures in agreement with previous works studying sorption behaviour of such mixtures. The rise of Rds is from 10(2) cm3 g(-1) for mixtures with 80% of sand to 10(3) cm3 g(-1) for pure clays. There are significant differences between natural and technologically modified clays.

[Occupational risk for development of respiratory diseases in foundry shop workers at machinery industries].

PubMed

Khamitova, R Ia; Loskutov, D V

2012-01-01

The paper provides the results of assessment of prior and posterior occupational risks and those of questionnaire analysis in foundry shop workers from machinery enterprises. According to the data of attestation of job places, the working conditions of major foundry occupations were ascertained to correspond to class 3, grades 1 to 3. The prior risk for occupational respiratory diseases (RD) was defined as moderate whereas the posterior risk was high. According to the results of a questionnaire survey, more than half of the workers sought medical advice for bronchopulmonary pathology. Determination of whether there is, in terms of the etiological share, a cause-and-effect relationship between RDs and working conditions has shown that the occupation was highly responsible, which suggests that harmful industrial factors make a considerable contribution to the development of RDs in the workers of the enterprises under study.

Perfluoropentacene adsorption on Cu(110)

NASA Astrophysics Data System (ADS)

Gall, J.; Zhang, L.; Fu, X.; Zeppenfeld, P.; Sun, L. D.

2017-09-01

The adsorption of perfluoropentacene (PFP) on the Cu(110) surface has been investigated using reflectance difference spectroscopy (RDS), low-energy electron diffraction, and low-temperature scanning tunneling microscopy. The PFP molecules within the first monolayer align their long molecular axis exclusively oriented along the [001] azimuthal direction of the Cu substrate. In comparison with the adsorption behavior of pentacene on the same surface, a strong effect of the fluorination regarding the molecular orientation and the intermolecular and molecule-substrate interactions was identified. Furthermore, a two-dimensional gas-solid phase transition accompanied by a reversible azimuthal rotation of the PFP molecules was observed at the beginning of the second monolayer growth. The change of the optical anisotropy associated with this reorientation was used to explore the two-dimensional (2D) condensation as a function of coverage and temperature by RDS, and the 2D heat of condensation in the PFP bilayer on Cu(110) was determined to be 105 meV.

"Liking" and "wanting" linked to Reward Deficiency Syndrome (RDS): hypothesizing differential responsivity in brain reward circuitry.

PubMed

Blum, Kenneth; Gardner, Eliot; Oscar-Berman, Marlene; Gold, Mark

2012-01-01

In an attempt to resolve controversy regarding the causal contributions of mesolimbic dopamine (DA) systems to reward, we evaluate the three main competing explanatory categories: "liking,"learning," and "wanting" [1]. That is, DA may mediate (a) the hedonic impact of reward (liking), (b) learned predictions about rewarding effects (learning), or (c) the pursuit of rewards by attributing incentive salience to reward-related stimuli (wanting). We evaluate these hypotheses, especially as they relate to the Reward Deficiency Syndrome (RDS), and we find that the incentive salience or "wanting" hypothesis of DA function is supported by a majority of the evidence. Neuroimaging studies have shown that drugs of abuse, palatable foods, and anticipated behaviors such as sex and gaming affect brain regions involving reward circuitry, and may not be unidirectional. Drugs of abuse enhance DA signaling and sensitize mesolimbic mechanisms that evolved to attribute incentive salience to rewards. Addictive drugs have in common that they are voluntarily selfadministered, they enhance (directly or indirectly) dopaminergic synaptic function in the nucleus accumbens (NAC), and they stimulate the functioning of brain reward circuitry (producing the "high" that drug users seek). Although originally believed simply to encode the set point of hedonic tone, these circuits now are believed to be functionally more complex, also encoding attention, reward expectancy, disconfirmation of reward expectancy, and incentive motivation. Elevated stress levels, together with polymorphisms of dopaminergic genes and other neurotransmitter genetic variants, may have a cumulative effect on vulnerability to addiction. The RDS model of etiology holds very well for a variety of chemical and behavioral addictions.

Repair-mediated duplication by capture of proximal chromosomal DNA has shaped vertebrate genome evolution.

PubMed

Pace, John K; Sen, Shurjo K; Batzer, Mark A; Feschotte, Cédric

2009-05-01

DNA double-strand breaks (DSBs) are a common form of cellular damage that can lead to cell death if not repaired promptly. Experimental systems have shown that DSB repair in eukaryotic cells is often imperfect and may result in the insertion of extra chromosomal DNA or the duplication of existing DNA at the breakpoint. These events are thought to be a source of genomic instability and human diseases, but it is unclear whether they have contributed significantly to genome evolution. Here we developed an innovative computational pipeline that takes advantage of the repetitive structure of genomes to detect repair-mediated duplication events (RDs) that occurred in the germline and created insertions of at least 50 bp of genomic DNA. Using this pipeline we identified over 1,000 probable RDs in the human genome. Of these, 824 were intra-chromosomal, closely linked duplications of up to 619 bp bearing the hallmarks of the synthesis-dependent strand-annealing repair pathway. This mechanism has duplicated hundreds of sequences predicted to be functional in the human genome, including exons, UTRs, intron splice sites and transcription factor binding sites. Dating of the duplication events using comparative genomics and experimental validation revealed that the mechanism has operated continuously but with decreasing intensity throughout primate evolution. The mechanism has produced species-specific duplications in all primate species surveyed and is contributing to genomic variation among humans. Finally, we show that RDs have also occurred, albeit at a lower frequency, in non-primate mammals and other vertebrates, indicating that this mechanism has been an important force shaping vertebrate genome evolution.

Motivational Interviewing and Dietary Counseling for Obesity in Primary Care: An RCT

PubMed Central

McMaster, Fiona; Bocian, Alison; Harris, Donna; Zhou, Yan; Snetselaar, Linda; Schwartz, Robert; Myers, Esther; Gotlieb, Jaquelin; Foster, Jan; Hollinger, Donna; Smith, Karen; Woolford, Susan; Mueller, Dru; Wasserman, Richard C.

2015-01-01

BACKGROUND AND OBJECTIVE: Few studies have tested the impact of motivational interviewing (MI) delivered by primary care providers on pediatric obesity. This study tested the efficacy of MI delivered by providers and registered dietitians (RDs) to parents of overweight children aged 2 through 8. METHODS: Forty-two practices from the Pediatric Research in Office Settings Network of the American Academy of Pediatrics were randomly assigned to 1 of 3 groups. Group 1 (usual care) measured BMI percentile at baseline and 1- and 2-year follow-up. Group 2 (provider only) delivered 4 MI counseling sessions to parents of the index child over 2 years. Group 3 (provider + RD) delivered 4 provider MI sessions plus 6 MI sessions from a RD. The primary outcome was child BMI percentile at 2-year follow up. RESULTS: At 2-year follow-up, the adjusted BMI percentile was 90.3, 88.1, and 87.1 for groups 1, 2, and 3, respectively. The group 3 mean was significantly (P = .02) lower than group 1. Mean changes from baseline in BMI percentile were 1.8, 3.8, and 4.9 across groups 1, 2, and 3. CONCLUSIONS: MI delivered by providers and RDs (group 3) resulted in statistically significant reductions in BMI percentile. Research is needed to determine the clinical significance and persistence of the BMI effects observed. How the intervention can be brought to scale (in particular, how to train physicians to use MI effectively and how best to train RDs and integrate them into primary care settings) also merits future research. PMID:25825539

Do the disc degeneration and osteophyte contribute to the curve rigidity of degenerative scoliosis?

PubMed

Zhu, Feng; Bao, Hongda; Yan, Peng; Liu, Shunan; Bao, Mike; Zhu, Zezhang; Liu, Zhen; Qiu, Yong

2017-03-29

The factors associated with lateral curve flexibility in degenerative scoliosis have not been well documented. Disc degeneration could result in significant change in stiffness and range of motion in lateral bending films. The osteophytes could be commonly observed in degenerative spine but the relationship between osteophyte formation and curve flexibility remains controversial. The aim of the current study is to clarify if the disc degeneration and osteophyte formation were both associated with curve flexibility of degenerative scoliosis. A total of 85 patients were retrospectively analyzed. The inclusion criteria were as follow: age greater than 45 years, diagnosed as degenerative scoliosis and coronal Cobb angle greater than 20°. Curve flexibility was calculated based on Cobb angle, and range of motion (ROM) was based on disc angle evaluation. Regional disc degeneration score (RDS) was obtained according to Pfirrmann classification and osteophyte formation score (OFS) was based on Nanthan classification. Spearman correlation was performed to analyze the relationship between curve flexibility and RDS as well as OFS. Moderate correlation was found between RDS and curve flexibility with a Spearman coefficient of -0.487 (P = 0.009). Similarly, moderate correlation was observed between curve flexibility and OFS with a Spearman coefficient of -0.429 (P = 0.012). Strong correlation was found between apical ROM and OFS compared to the relationship between curve flexibility and OFS with a Spearman coefficient of -0.627 (P < 0.001). Both disc degeneration and osteophytes formation correlated with curve rigidity. The pre-operative evaluation of both features may aid in the surgical decision-making in degenerative scoliosis patients.

Exposure to Elemental Carbon, Organic Carbon, Nitrate, and Sulfate Fractions of Fine Particulate Matter and Risk of Preterm Birth in New Jersey, Ohio, and Pennsylvania (2000–2005)

PubMed Central

Daniels, Julie L.; Messer, Lynne C.; Poole, Charles; Lobdell, Danelle T.

2015-01-01

Background Particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) has been consistently associated with preterm birth (PTB) to varying degrees, but roles of PM2.5 species have been less studied. Objective We estimated risk differences (RD) of PTB (reported per 106 pregnancies) associated with change in ambient concentrations of elemental carbon (EC), organic carbon (OC), nitrates (NO3), and sulfates (SO4). Methods From live birth certificates from three states, we constructed a cohort of singleton pregnancies at or beyond 20 weeks of gestation from 2000 through 2005 (n = 1,771,225; 8% PTB). We estimated mean species exposures for each week of gestation from monitor-corrected Community Multi-Scale Air Quality modeling data. RDs and 95% confidence intervals (CIs) for four PTB categories were estimated for each exposure using linear regression, adjusted for maternal race/ethnicity, marital status, education, age, smoking, maximum temperature, ozone, and season of conception. We also adjusted for other species in multi-species models. Results RDs varied by exposure window and outcome period. EC was positively associated with PTB after 27 and before 35 weeks of gestation. For example, for a 0.25-μg/m3 increase in EC exposure during gestational week 9, RD = 96 (95% CI: –20, 213) and RD = 145 (95% CI: –50, 341) for PTB during weeks 28–31 and 32–34, respectively. Associations with OCs were null or negative. RDs for NO3 were elevated with exposure in early weeks of gestation, and null in later weeks. RDs for SO4 exposure were positively associated with PTB, though magnitude varied across gestational weeks. We observed effect measure modification for associations between EC and PTB by race/ethnicity and smoking status. Conclusion EC and SO4 may contribute to associations between PM2.5 and PTB. Associations varied according to the timing of exposure and the timing of PTB. Citation Rappazzo KM, Daniels JL, Messer LC, Poole C, Lobdell DT. 2015. Exposure to elemental carbon, organic carbon, nitrate, and sulfate fractions of fine particulate matter and risk of preterm birth in New Jersey, Ohio, and Pennsylvania (2000–2005). Environ Health Perspect 123:1059–1065; http://dx.doi.org/10.1289/ehp.1408953 PMID:25910280

The Parasol Protocol: An Implementation Science Study of HIV Continuum of Care Interventions for Gay Men and Transgender Women in Burma/Myanmar

PubMed Central

Naing, Soe; Clouse, Emily; Thu, Kaung Htet; Mon, Sandra Hsu Hnin; Tun, Zin Min; Baral, Stefan; Paing, Aung Zayar; Beyrer, Chris

2017-01-01

Background Efforts to improve HIV diagnosis and antiretroviral therapy (ART) initiation among people living with HIV and reduce onward transmission of HIV rely on innovative interventions along multiple steps of the HIV care continuum. These innovative methods are particularly important for key populations, including men who have sex with men (MSM) and transgender women (TW). The HIV epidemic in Myanmar is concentrated among key populations, and national efforts now focus on reducing stigma and improving engagement of MSM and TW in HIV prevention and care. Objective This study aims to test the use of several innovations to address losses in the HIV care continuum: (1) use of respondent-driven sampling (RDS) to reach and engage MSM and TW in HIV testing, (2) HIV self-testing (HIVST) to increase HIV testing uptake and aid early diagnosis of infection, (3) community-based CD4 point-of-care (POC) technology to rapidly stage HIV disease for those who are HIV infected, and (4) peer navigation support to increase successful health system navigation for HIV-infected MSM and TW in need of ART or HIV engagement in care. Methods To assess the effect of HIVST, we will implement a randomized trial in which MSM and TW adults in the greater Yangon metropolitan area who are HIV uninfected will be recruited via RDS (N=366). Participants will complete a baseline socio-behavioral survey and will be randomized to standard, voluntary counseling and testing (VCT) or to HIVST. Biologic specimens will be collected during this baseline visit for confirmatory testing using dried blood spots. Participants will be asked to return to the study office to complete a second study visit in which they will report their HIV test result and answer questions on the acceptability of the assigned testing method. Aim 1 participants with confirmed HIV infection and who are not engaged in care (N=49) will be offered direct enrollment into Aims 2 and 3, which include immediate CD4 POC and the option for peer navigation, respectively. Aims 2 and 3 participants will be prospectively followed for 12 months with data collection including interviewer-administered sociobehavioral survey, CD4 POC, and viral load testing occurring biannually. Participants who accept peer navigation will be compared to those who decline peer navigation. Analyses will estimate the impact of CD4 POC on engagement in care and the impact of peer navigation on ART adherence and viral load. Results Formative qualitative research was conducted in June and September 2015 and led to further refinement of recruitment methods, HIVST instructions and counseling, and peer navigation methods. Aim 1 recruitment began in November 2015 with subsequent enrollment into Aims 2 and 3 and is currently ongoing. Conclusions These innovative interventions may resolve gaps in the HIV care continuum among MSM and TW and future implementation may aid in curbing the HIV epidemic among MSM and TW in Myanmar. PMID:28526661

Is violence associated with increased risk behavior among MSM? Evidence from a population-based survey conducted across nine cities in Central America

PubMed Central

Wheeler, Jennifer; Anfinson, Katherine; Valvert, Dennis; Lungo, Susana

2014-01-01

Background/Objective There is a dearth of research examining the linkages between violence and HIV risk behavior among men who have sex with men (MSM), including those who identify as transgender women (TW), particularly in Central America where violence is widespread. In this paper, we use population-based survey results to independently examine the correlations between physical, emotional and sexual violence and HIV risk behavior among MSM populations in five countries in Central America. Design As part of USAID's Combination Prevention for HIV program in Central America, PASMO conducted population based surveys using respondent-driven sampling (RDS) in nine cities in Guatemala, El Salvador, Nicaragua, Costa Rica, and Panama. Initial seeds were recruited using the following criteria: individuals who represented subgroups of MSM by self-identification (homosexual vs. heterosexual or bisexual vs. transgender), social economic strata, and by sex work practices. This study examines the association between violence and 1) HIV risk behaviors relevant to the study populations; 2) protective behaviors; and 3) reported STIs. Individualized RDS estimator weights for each outcome variable were calculated using RDSAT software, and logistic regression analysis was used to determine associations between different forms of violence and the outcome variables. Results MSM who experienced physical violence were more likely to be engaged in transactional sex (OR: 1.76 [1.42–2.18]), have multiple partners in the past 30 days (OR: 1.37 [1.09–1.71]), and have engaged in sex under the influence of alcohol or drugs (OR: 1.51 [1.24–1.83]). Both physical violence and psychological/verbal violence were also associated with reporting STI symptoms or diagnosis within the past 12 months (OR: 1.72 [1.34–2.21] and 1.80 [1.45–2.23]). The effects of violence on the outcomes were observed after controlling for other risk factors. Transgender women were 3.9 times more likely to report engaging in transactional sex. Respondents who were heterosexual, bisexual, or transgender were also more likely to both report multiple partnerships (OR: 1.44 [1.07–1.96], 1.99 [1.67–2.38], 1.79 [1.37–2.33], respectively) and more likely to report engaging in sex under the influence of alcohol or drugs (OR: 1.52 [1.15–2.01], 1.38 [1.17–1.63], 1.47 [1.16–1.87], respectively), as compared to those identifying as homosexual. Conclusion Violence experienced by MSM and TW is widespread in Central America. The experience of violence is shown in this study to be independently associated with risk behaviors for HIV infections. Further research and studies are needed to identify the effects violence has on HIV risk behavior among this under-researched population to improve targeted HIV prevention interventions. PMID:25361722

Heated, Humidified High-Flow Nasal Cannula vs Nasal Continuous Positive Airway Pressure for Respiratory Distress Syndrome of Prematurity: A Randomized Clinical Noninferiority Trial.

PubMed

Lavizzari, Anna; Colnaghi, Mariarosa; Ciuffini, Francesca; Veneroni, Chiara; Musumeci, Stefano; Cortinovis, Ivan; Mosca, Fabio

2016-08-08

Heated, humidified high-flow nasal cannula (HHHFNC) has gained increasing popularity as respiratory support for newborn infants thanks to ease of use and improved patient comfort. However, its role as primary therapy for respiratory distress syndrome (RDS) of prematurity needs to be further elucidated by large, randomized clinical trials. To determine whether HHHFNC provides respiratory support noninferior to nasal continuous positive airway pressure (nCPAP) or bilevel nCPAP (BiPAP) as a primary approach to RDS in infants older than 28 weeks' gestational age (GA). An unblinded, monocentric, randomized clinical noninferiority trial at a tertiary neonatal intensive care unit. Inborn infants at 29 weeks 0 days to 36 weeks 6 days of GA were eligible if presenting with mild to moderate RDS requiring noninvasive respiratory support. Criteria for starting noninvasive respiratory support were a Silverman score of 5 or higher or a fraction of inspired oxygen higher than 0.3 for a target saturation of peripheral oxygen of 88% to 93%. Infants were ineligible if they had major congenital anomalies or severe RDS requiring early intubation. Infants were enrolled between January 5, 2012, and June 28, 2014. Randomization to either HHHFNC at 4 to 6 L/min or nCPAP/BiPAP at 4 to 6 cm H2O. Need for mechanical ventilation within 72 hours from the beginning of respiratory support. The absolute risk difference in the primary outcome and its 95% confidence interval were calculated to determine noninferiority (noninferiority margin, 10%). An intention-to-treat analysis was performed. A total of 316 infants were enrolled in the study: 158 in the HHHFNC group (mean [SD] GA, 33.1 [1.9] weeks; 52.5% female) and 158 in the nCPAP/BiPAP group (mean [SD] GA, 33.0 [2.1] weeks; 47.5% female). The use of HHHFNC was noninferior to nCPAP with regard to the primary outcome: failure occurred in 10.8% vs 9.5% of infants, respectively (95% CI of risk difference, -6.0% to 8.6% [within the noninferiority margin]; P = .71). Significant between-group differences in secondary outcomes were not found between the HHHFNC and nCPAP/BiPAP groups, including duration of respiratory support (median [interquartile range], 4.0 [2.0 to 6.0] vs 4.0 [2.0 to 7.0] days; 95% CI of difference in medians, -1.0 to 0.5; P = .45), need for surfactant (44.3% vs 46.2%; 95% CI of risk difference, -9.8 to 13.5; P = .73), air leaks (1.9% vs 2.5%; 95% CI of risk difference, -3.3 to 4.5; P = .70), and bronchopulmonary dysplasia (4.4% vs 5.1%; 95% CI of risk difference, -3.9 to 7.2; P = .79). In this study, HHHFNC showed efficacy and safety similar to those of nCPAP/BiPAP when applied as a primary approach to mild to moderate RDS in preterm infants older than 28 weeks' GA. clinicaltrials.gov Identifier: NCT02570217.

Development of Civic Engagement: Theoretical and Methodological Issues

ERIC Educational Resources Information Center

Lerner, Richard M.; Wang, Jun; Champine, Robey B.; Warren, Daniel J. A.; Erickson, Karl

2014-01-01

Within contemporary developmental science, models derived from relational developmental systems (RDS) metatheory emphasize that the basic process of human development involves mutually-influential relations, termed developmental regulations, between the developing individual and his or her complex and changing physical, social, and cultural…

77 FR 24103 - National Registry of Certified Medical Examiners

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-20

... Indiana Statewide Association of Rural Electric Cooperatives LTCCS Large Truck Crash Causation Study LFC... Personally Identifiable Information PRA Paperwork Reduction Act RDS Role Delineation Study RIA Regulatory... evidence, studies, or data were presented in support of restricting PAs from performing examinations on...

Out-of-pocket drug costs and drug utilization patterns of postmenopausal Medicare beneficiaries with osteoporosis.

PubMed

Conwell, Leslie Jackson; Esposito, Dominick; Garavaglia, Susan; Meadows, Eric S; Colby, Margaret; Herrera, Vivian; Goldfarb, Seth; Ball, Daniel; Marciniak, Martin

2011-08-01

The Medicare Part D coverage gap has been associated with lower adherence and drug utilization and higher discontinuation. Because osteoporosis has a relatively high prevalence among Medicare-eligible postmenopausal women, we examined changes in utilization of osteoporosis medications during this coverage gap. The purpose of this study was to investigate changes in out-of-pocket (OOP) drug costs and utilization associated with the Medicare Part D coverage gap among postmenopausal beneficiaries with osteoporosis. This retrospective analysis of 2007 pharmacy claims focuses on postmenopausal female Medicare beneficiaries enrolled in full-, partial-, or no-gap exposure standard or Medicare Advantage prescription drug plans (PDPs), retiree drug subsidy (RDS) plans, or the low-income subsidy program. We compared beneficiaries with osteoporosis who were taking teriparatide (Eli Lilly and Company, Indianapolis, Indiana) (n = 5657) with matched samples of beneficiaries who were taking nonteriparatide osteoporosis medications (NTO; n = 16,971) or who had other chronic conditions (OCC; n = 16,971). We measured average monthly prescription drug fills and OOP costs, medication discontinuation, and skipping. More than half the sample reached the coverage gap; OOP costs then rose for teriparatide users enrolled in partial- or full-gap exposure plans (increase of 121% and 186%; $300 and $349) but fell for those in no-gap exposure PDPs or RDS plans (decrease of 49% and 30%; $131 and $40). OOP costs for beneficiaries in partial- or full-gap exposure PDPs increased >120% (increase of $144 and $176) in the NTO group and nearly doubled for the OCC group (increase of $124 and $151); these OOP costs were substantially lower than those for teriparatide users. Both teriparatide users and NTO group members discontinued or skipped medications more often than persons in the OCC group, regardless of plan or benefit design. Medication discontinuation and OOP costs among beneficiaries with osteoporosis were highest for those enrolled in Part D plans with a coverage gap. Providers should be aware of potential cost-related nonadherence among Medicare beneficiaries taking osteoporosis medications. Copyright © 2011 Elsevier HS Journals, Inc. All rights reserved.

Adverse Maternal and Neonatal Outcomes in Indicated Compared with Spontaneous Preterm Birth in Healthy Nulliparas: A Secondary Analysis of a Randomized Trial.

PubMed

Tita, Alan T; Doherty, Lindsay; Roberts, Jim M; Myatt, Leslie; Leveno, Kenneth J; Varner, Michael W; Wapner, Ronald J; Thorp, John M; Mercer, Brian M; Peaceman, Alan; Ramin, Susan M; Carpenter, Marshall W; Iams, Jay; Sciscione, Anthony; Harper, Margaret; Tolosa, Jorge E; Saade, George R; Sorokin, Yoram

2018-06-01

 To compare the risks of adverse maternal and neonatal outcomes associated with spontaneous (SPTB) versus indicated preterm births (IPTB).  A secondary analysis of a multicenter trial of vitamin C and E supplementation in healthy low-risk nulliparous women. Outcomes were compared between women with SPTB (due to spontaneous membrane rupture or labor) and those with IPTB (due to medical or obstetric complications). A primary maternal composite outcome included: death, pulmonary edema, blood transfusion, adult respiratory distress syndrome (RDS), cerebrovascular accident, acute tubular necrosis, disseminated intravascular coagulopathy, or liver rupture. A neonatal composite outcome included: neonatal death, RDS, grades III or IV intraventricular hemorrhage (IVH), sepsis, necrotizing enterocolitis (NEC), or retinopathy of prematurity.  Of 9,867 women, 10.4% ( N  = 1,038) were PTBs; 32.7% ( n  = 340) IPTBs and 67.3% ( n  = 698) SPTBs. Compared with SPTB, the composite maternal outcome was more frequent in IPTB-4.4% versus 0.9% (adjusted odds ratio [aOR], 4.0; 95% confidence interval [CI], 1.4-11.8), as were blood transfusion and prolonged hospital stay (3.2 and 3.7 times, respectively). The frequency of composite neonatal outcome was higher in IPTBs (aOR, 1.8; 95% CI, 1.1-3.0), as were RDS (1.7 times), small for gestational age (SGA) < 5th percentile (7.9 times), and neonatal intensive care unit (NICU) admission (1.8 times).  Adverse maternal and neonatal outcomes were significantly more likely with IPTB than with SPTB. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A randomized controlled trial of post-extubation bubble continuous positive airway pressure versus Infant Flow Driver continuous positive airway pressure in preterm infants with respiratory distress syndrome.

PubMed

Gupta, Samir; Sinha, Sunil K; Tin, Win; Donn, Steven M

2009-05-01

To compare the efficacy and safety of bubble continuous positive airway pressure (CPAP) and Infant Flow Driver (IFD) CPAP for the post-extubation management of preterm infants with respiratory distress syndrome (RDS). A total of 140 preterm infants at 24 to 29 weeks' gestation or with a birth weight of 600 to 1500 g who were ventilated at birth for RDS were randomized to receive either IFD CPAP (a variable-flow device) or bubble CPAP (a continuous-flow device). A standardized protocol was used for extubation and CPAP. No crossover was allowed. The primary outcome was successful extubation maintained for at least 72 hours. Secondary outcomes included successful extubation maintained for 7 days, total duration of CPAP support, chronic lung disease, and complications of prematurity. Seventy-one infants were randomized to bubble CPAP, and 69 were randomized to IFD CPAP. Mean gestational age and birth weight were similar in the 2 groups, as were the proportions of infants who achieved successful extubation for 72 hours and for 7 days. However, the median duration of CPAP support was 50% shorter in the infants on bubble CPAP. Moreover, in the subset of infants who were ventilated for less than 14 days, the infants on bubble CPAP had a significantly lower extubation failure rate. There was no difference in the incidence of chronic lung disease or other complications between the 2 study groups. Bubble CPAP is as effective as IFD CPAP in the post-extubation management of infants with RDS; however, in infants ventilated for < or = 14 days, bubble CPAP is associated with a significantly higher rate of successful extubation. Bubble CPAP also is associated with a significantly reduced duration of CPAP support.

Morbidity and mortality of neonatal respiratory failure in China: surfactant treatment in very immature infants.

PubMed

Wang, Huanhuan; Gao, Xirong; Liu, Cuiqing; Yan, Chaoying; Lin, Xinzhu; Yang, Changyi; Lin, Zhenlang; Zhu, Wenjun; Yang, Zhenying; Yu, Fengqin; Qiu, Yinping; Liu, Xianzhi; Zhou, Xiaoyu; Chen, Chao; Sun, Bo

2012-03-01

We retrospectively investigated incidence, morbidity, and mortality of neonatal respiratory failure (NRF) in China, with special emphasis on surfactant treated very immature infants. NRF was defined as respiratory hypoxemia requiring mechanical ventilation and/or nasal continuous positive airway pressure for at least 24 hours. There were 6864 cases of NRF, composing 19.7% of total admissions to 55 NICUs in 2008. Of these cases, 62.8% were preterm, and 16.4% of very low birth weight (VLBW, <1500 g). The primary diseases were respiratory distress syndrome (RDS, 43.9%), pneumonia/sepsis (21.7%), transient respiratory insufficiency (14.7%), transient tachypnea (8.1%), and meconium aspiration syndrome (7.0%). Surfactant was given to 26.8% of infants with NRF and 54.8% infants with RDS. The survival rate of surfactant-treated RDS was 79.9% compared to 71.8% in those not receiving surfactant (P < .001). This was also true in those of VLBW, 59.8% vs 52.2% (P = .035), respectively. The overall survival rate in NRF cases was 75.3%, but it was 58.1% among VLBW infants; for those infants of 25, 26, and 27 to 28 weeks' gestational age, the survival rates were ∼6%, 30%, and 50%, respectively; and the survival rates for infants with meconium aspiration syndrome and pneumonia/sepsis were 70.3% and 71.4%, respectively. The care burden was associated with high treatment withdrawal and death rate. The outcomes of NRF, especially in extremely premature infants, reflect both progress and persistent limitations in providing respiratory support in the emerging NICUs of China, but overall survival for sick newborns had improved steadily.

“Liking” and “Wanting” Linked to Reward Deficiency Syndrome (RDS): Hypothesizing Differential Responsivity in Brain Reward Circuitry

PubMed Central

Blum, Kenneth; Gardner, Eliot; Oscar-Berman, Marlene; Gold, Mark

2013-01-01

In an attempt to resolve controversy regarding the causal contributions of mesolimbic dopamine (DA) systems to reward, we evaluate the three main competing explanatory categories: “liking,” “learning,” and “wanting” [1]. That is, DA may mediate (a) the hedonic impact of reward (liking), (b) learned predictions about rewarding effects (learning), or (c) the pursuit of rewards by attributing incentive salience to reward-related stimuli (wanting). We evaluate these hypotheses, especially as they relate to the Reward Deficiency Syndrome (RDS), and we find that the incentive salience or “wanting” hypothesis of DA function is supported by a majority of the evidence. Neuroimaging studies have shown that drugs of abuse, palatable foods, and anticipated behaviors such as sex and gaming affect brain regions involving reward circuitry, and may not be unidirectional. Drugs of abuse enhance DA signaling and sensitize mesolimbic mechanisms that evolved to attribute incentive salience to rewards. Addictive drugs have in common that they are voluntarily self-administered, they enhance (directly or indirectly) dopaminergic synaptic function in the nucleus accumbens, and they stimulate the functioning of brain reward circuitry (producing the “high” that drug users seek). Although originally believed simply to encode the set point of hedonic tone, these circuits now are believed to be functionally more complex, also encoding attention, reward expectancy, disconfirmation of reward expectancy, and incentive motivation. Elevated stress levels, together with polymorphisms of dopaminergic genes and other neurotransmitter genetic variants, may have a cumulative effect on vulnerability to addiction. The RDS model of etiology holds very well for a variety of chemical and behavioral addictions. PMID:22236117

AI And Early Vision - Part II

NASA Astrophysics Data System (ADS)

Julesz, Bela

1989-08-01

A quarter of a century ago I introduced two paradigms into psychology which in the intervening years have had a direct impact on the psychobiology of early vision and an indirect one on artificial intelligence (AI or machine vision). The first, the computer-generated random-dot stereogram (RDS) paradigm (Julesz, 1960) at its very inception posed a strategic question both for AI and neurophysiology. The finding that stereoscopic depth perception (stereopsis) is possible without the many enigmatic cues of monocular form recognition - as assumed previously - demonstrated that stereopsis with its basic problem of finding matches between corresponding random aggregates of dots in the left and right visual fields became ripe for modeling. Indeed, the binocular matching problem of stereopsis opened up an entire field of study, eventually leading to the computational models of David Marr (1982) and his coworkers. The fusion of RDS had an even greater impact on neurophysiologists - including Hubel and Wiesel (1962) - who realized that stereopsis must occur at an early stage, and can be studied easier than form perception. This insight recently culminated in the studies by Gian Poggio (1984) who found binocular-disparity - tuned neurons in the input stage to the visual cortex (layer IVB in V1) in the monkey that were selectively triggered by dynamic RDS. Thus the first paradigm led to a strategic insight: that with stereoscopic vision there is no camouflage, and as such was advantageous for our primate ancestors to evolve the cortical machinery of stereoscopic vision to capture camouflaged prey (insects) at a standstill. Amazingly, although stereopsis evolved relatively late in primates, it captured the very input stages of the visual cortex. (For a detailed review, see Julesz, 1986a)

Efficacy of INSURE during nasal CPAP in preterm infants with respiratory distress syndrome.

PubMed

Leone, F; Trevisanuto, D; Cavallin, F; Parotto, M; Zanardo, V

2013-04-01

INSURE (INtubation, SURfactant, Extubation) is a proven complement of nasal CPAP (nCPAP) for respiratory distress syndrome (RDS) treatment of preterm infants. Early administration is characterized by greater success. We aimed to determine the efficacy and failure or other respiratory outcomes of INSURE administration during nasal continous positive airway pressure (nCPAP) treatment of RDS. Among 824 premature infants neonatal intensive care unit (NICU) admitted at Padua University Hospital during 2007-2009, 209 (25.4%) were managed by surfactant replacement (200 mg/kg, Curosurf®) if required >45% oxygen ("rescue" treatment), including 42 (20.1%) during nCPAP. Each premature infant treated with INSURE during nasal CPAP was compared to 2 consecutive control infants treated with surfactant during mechanical ventilation, matched for antenatal steroids, delivery route, gestational age, and sex. Infants with RDS, treated with nCPAP and INSURE-complement (N.=25), were comparable in Apgar score, need of PPV at birth, birth weight, pre-surfactant FiO2 and timing of surfactant replacement to controls. However, nCPAP and INSURE-complement was superior in terms both of oxygenation, evaluated as post-treatment FiO2 (Median, [IQR], 26 [21-40] vs. 21 [21-29]; P=0.03) and (a-A) pO2 (0.48 [0.45-0.60] vs. 0.58 [0.53-0.72]; P=0.03). The improved oxygenation was sustained over the following days. In addition, premature infants treated with nCPAP and INSURE-complement developed less respiratory co-morbidities, including pneumothorax, borncopulmonary disease (BPD), and BPD and death (P=0.04). INSURE-complement of nasal CPAP has a superior efficacy in terms of oxygenation improvement, maintenance of optimal oxygenation, and reduction of respiratory comorbidities respect to "rescue" surfactant administration during mechanical ventilation.

[Perinatal mortality and asphyxia in premature babies (author's transl)].

PubMed

Werle, P; Künzel, W

1975-08-01

The aim of the present investigation was to study the influence of O2-ventilation, blind buffer therapy with Na-bicarbonate, late cord clamping and infusion of low molculare weight dextran on morbidity of Respiratory-Distress-Syndrom (RDS) and mortality during the first week in infants with a birthweight of 2500 g and less. The charts of 536 infants were studied. There were 481 life birth and 55 stillbirth (10.2%). In 185 infants the pH and Base-excess in the umbilical arterial blood was meassured. The infants born in 1969--1971 were compaired with them born in 1972--1973. In 52% of the "premature infants" the pH was 7.25 U and lower and in 90% of the Base-Excess was --4.5 meq/l and more. The perinatal mortality (PM) was 30% and 13% (P less than 0.01) resp. There was a correlation to the birthweight. The decrease of the PM was related to the fall in mortality of infant during the first week: 21% and 4% resp. Here too, there was a correlation to birthweight and gestational age. The morbidity in RDS: 20.6% and 10.0% (P less than 0.01) and mortality following RDS: 79.3% and 35.0% resp. (P less than 0.01) was also low in 1972--1973. The results permit us to conclude that it is of great importance to correct fetal acidosis immediately after birth to prevent irreversible alterations in the lung. It could also be of value to encrease cardiac output and lungperfusion by late cord clamping and injection of dextran 40. The other procedures belong to standard managment in handling an asphyxiated fetus.

Chromium in urban sediment particulates: an integrated micro-chemical and XANES study

NASA Astrophysics Data System (ADS)

Taylor, Kevin; Byrne, Patrick; Hudson-Edwards, Karen

2015-04-01

Chromium is generally common within the urban sediment cascade as a result of abundant industrial and transport-related sources. The risks that Cr-bearing particles pose to ecosystems and humans depend on the solid phase chemical speciation of Cr in the particles. In this study, we use bulk chemical digests, sequential chemical extraction analysis, electron microscopy, electron microprobe and microfocus XANES analysis to describe the solid-phase speciation of Cr in urban particulate matter from both aquatic sediment and road dust sediment (RDS) in Manchester, UK. Cr-bearing grains within RDS are predominantly iron oxide grains, commonly of goethite or haematite mineralogy, but Cr-bearing silicate glass grains are also present. Iron oxide glass grains most likely have sorbed Cr, and derive from the rusting of Cr-steel particles from vehicles. Electron microprobe analysis indicates concentrations of Cr up to 3200 μg/g in these grains, and XANES analysis indicates that Cr(III) is the dominant oxidation state, with some trace amounts of Cr(VI). Cr-bearing grains within aquatic sediments are dominated by alumino-silicate glass grains derived from industrial waste. These grains contain Cr-rich areas with up to 19% Cr2O3 and XANES analysis indicates that Cr is present as Cr(III). The dominance of Cr(III) in these urban particulate grains suggests limited bioavailability or toxicity. However, the presence within two markedly different grain types (iron oxides and silicate glasses) indicates that the long-term geochemical behaviour and environmental risk of RDS and the aquatic sediments studied are likely to be quite different. These findings highlight the importance of understanding sources of metal contaminants in urban environments and the geochemical processes that affect their transfer through the urban sediment cascade and the wider river basin.

Nutritionally-important starch fractions of rice cultivars grown in southern United States.

USDA-ARS?s Scientific Manuscript database

Dietary starches can be classified into three major fractions, according to in vitro digestibility: rapidly digestible (RDS), slowly digestible (SDS), and resistant starch (RS). Literature indicates that SDS and/or RS have significant implications on human health, particularly, glucose metabolism, ...

DIRECT operational field test evaluation natural use study. Part 4, Recommendations for expanded deployment

DOT National Transportation Integrated Search

1998-08-01

The DIRECT project compared four low-cost driver information systems. Of the four that were : compared, the RDS approach proved superior to the others in toggling reliability and voice quality. The DIRECT project planned to expand the implementation ...

Early Language Abilities of High-Risk Infants.

ERIC Educational Resources Information Center

Hubatch, Leona M.; And Others

1985-01-01

Ten children with a history of prematurity and respiratory distress syndrome (RDS) were matched with 101 full-term controls in the single-word stage of language. Control subjects demonstrated superior performance on all receptive language and child verbosity measures despite their younger age. (Author/CL)

THE FORMATION OF ROTATIONAL DISCONTINUITIES IN COMPRESSIVE THREE-DIMENSIONAL MHD TURBULENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Liping; Feng, Xueshang; Zhang, Lei

Measurements of solar wind turbulence reveal the ubiquity of discontinuities. In this study we investigate how the discontinuities, especially rotational discontinuities (RDs), are formed in MHD turbulence. In a simulation of the decaying compressive three-dimensional (3D) MHD turbulence with an imposed uniform background magnetic field, we detect RDs with sharp field rotations and little variations of magnetic field intensity, as well as mass density. At the same time, in the de Hoffman–Teller frame, the plasma velocity is nearly in agreement with the Alfvén speed, and is field-aligned on both sides of the discontinuity. We take one of the identified RDsmore » to analyze its 3D structure and temporal evolution in detail. By checking the magnetic field and plasma parameters, we find that the identified RD evolves from the steepening of the Alfvén wave with moderate amplitude, and that steepening is caused by the nonuniformity of the Alfvén speed in the ambient turbulence.« less

Retinal dystrophies, genomic applications in diagnosis and prospects for therapy

PubMed Central

Nash, Benjamin M.; Wright, Dale C.; Grigg, John R.; Bennetts, Bruce

2015-01-01

Retinal dystrophies (RDs) are degenerative diseases of the retina which have marked clinical and genetic heterogeneity. Common presentations among these disorders include night or colour blindness, tunnel vision and subsequent progression to complete blindness. The known causative disease genes have a variety of developmental and functional roles with mutations in more than 120 genes shown to be responsible for the phenotypes. In addition, mutations within the same gene have been shown to cause different disease phenotypes, even amongst affected individuals within the same family highlighting further levels of complexity. The known disease genes encode proteins involved in retinal cellular structures, phototransduction, the visual cycle, and photoreceptor structure or gene regulation. This review aims to demonstrate the high degree of genetic complexity in both the causative disease genes and their associated phenotypes, highlighting the more common clinical manifestation of retinitis pigmentosa (RP). The review also provides insight to recent advances in genomic molecular diagnosis and gene and cell-based therapies for the RDs. PMID:26835369

Diverse Reductive Dehalogenases Are Associated with Clostridiales-Enriched Microcosms Dechlorinating 1,2-Dichloroethane

PubMed Central

Merlino, Giuseppe; Marzorati, Massimo; Rizzi, Aurora; Lavazza, Davide; de Ferra, Francesca; Carpani, Giovanna

2015-01-01

The achievement of successful biostimulation of active microbiomes for the cleanup of a polluted site is strictly dependent on the knowledge of the key microorganisms equipped with the relevant catabolic genes responsible for the degradation process. In this work, we present the characterization of the bacterial community developed in anaerobic microcosms after biostimulation with the electron donor lactate of groundwater polluted with 1,2-dichloroethane (1,2-DCA). Through a multilevel analysis, we have assessed (i) the structural analysis of the bacterial community; (ii) the identification of putative dehalorespiring bacteria; (iii) the characterization of functional genes encoding for putative 1,2-DCA reductive dehalogenases (RDs). Following the biostimulation treatment, the structure of the bacterial community underwent a notable change of the main phylotypes, with the enrichment of representatives of the order Clostridiales. Through PCR targeting conserved regions within known RD genes, four novel variants of RDs previously associated with the reductive dechlorination of 1,2-DCA were identified in the metagenome of the Clostridiales-dominated bacterial community. PMID:26273600

Effect of sourdough addition and storage time on in vitro starch digestibility and estimated glycemic index of tef bread.

PubMed

Shumoy, Habtu; Van Bockstaele, Filip; Devecioglu, Dilara; Raes, Katleen

2018-10-30

The effect of sourdough amount and storage time on starch digestibility and estimated glycemic index (eGI) of tef bread was investigated. The rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) of 0-30% sourdough fresh tef breads ranged from 49 to 58, 16 to 29 and 20 to 26 g/100 g starch, respectively. Storage of tef breads up to 5 days decreased the RDS by more than 2-fold while SDS and RS increased by 2 and 3 fold, respectively. The eGI for fresh and stored breads ranged from 39 to 89. Addition of sourdough increased the eGI of fresh breads while no uniform pattern was seen in the stored breads. As the storage time increased, all the breads showed a decrease in eGI. In vivo study is necessary to further investigate the effect of sourdough on GI of tef bread. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dopamine homeostasis: brain functional connectivity in reward deficiency syndrome.

PubMed

Febo, Marcelo; Blum, Kenneth; Badgaiyan, Rajendra D; Baron, David; Thanos, Panayotis K; Colon-Perez, Luis M; Demortrovics, Zsolt; Gold, Mark S

2017-01-01

Reward deficiency syndrome (RDS) was first proposed by Kenneth Blum in 1995 to provide a clinically relevant and predictive term for conditions involving deficits in mesocorticolimbic dopamine function. Genetic, molecular, and neuronal alterations in key components of this circuitry contribute to a reward deficit state that can drive drug-seeking, consumption, and relapse. Among the dysfunctions observed in RDS are dysregulated resting state networks, which recently have been assessed in detail in chronic drug users by, positron emission tomography, functional magnetic resonance imaging, and functional connectivity analysis. A growing number of studies are helping to determine the putative roles of dopamine and glutamatergic neurotransmission in the regulation of activity in resting state networks, particularly in brain reward circuitry affected in drug use disorders. Indeed, we hypothesize in the present review that loss of homeostasis of these systems may lead to 'unbalanced' functional networks that might be both cause and outcome of disrupted synaptic communication between cortical and subcortical systems essential for controlling reward, emotional control, sensation seeking, and chronic drug use.

Causal mediation analysis with a binary outcome and multiple continuous or ordinal mediators: Simulations and application to an alcohol intervention.

PubMed

Nguyen, Trang Quynh; Webb-Vargas, Yenny; Koning, Ina M; Stuart, Elizabeth A

We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: 1) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, 2) predict potential outcome probabilities, and 3) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance/covariance. We evaluate the estimation of risk-difference- and risk-ratio-based effects (RDs, RRs) using the ML, WLSMV and Bayes estimators in Mplus. Across most variations in path-coefficient and mediator-residual-correlation signs and strengths, and confounding situations investigated, the method performs well with all estimators, but favors ML/WLSMV for RDs with continuous mediators, and Bayes for RRs with ordinal mediators. Bayes outperforms WLSMV/ML regardless of mediator type when estimating RRs with small potential outcome probabilities and in two other special cases. An adolescent alcohol prevention study is used for illustration.

Effect on in vitro starch digestibility of Mexican blue maize anthocyanins.

PubMed

Camelo-Méndez, Gustavo A; Agama-Acevedo, Edith; Sanchez-Rivera, Mirna M; Bello-Pérez, Luis A

2016-11-15

The purpose of this study was to evaluate the effect of blue maize extracts obtained by acid-methanol treatment on the nutritional in vitro starch fractions such as: rapidly digestive starch (RDS), slowly digestive starch (SDS) and resistant starch (RS) of native and gelatinized commercial maize starch. Chromatographic analysis (HPLC-DAD/ESI-MS) of blue maize extracts showed the presence of seven anthocyanins, where cyanidin-3-(6″-malonylglucoside) was the main. Blue maize extracts modified nutritional in vitro starch fractions (decrease of RDS) while RS content increased (1.17 and 2.02 times for native and gelatinized commercial maize starch, respectively) when anthocyanins extracts were added to starch up to 75% (starch weight). This preliminary observation provides the basis for further suitability evaluation of blue maize extract as natural starch-modifier by the possible anthocyanins-starch interaction. Anthocyanin extracts can be a suitable to produce functional foods with higher RS content with potential human health benefits. Copyright © 2016 Elsevier Ltd. All rights reserved.

μ-PIV/Shadowgraphy measurements to elucidate dynamic physicochemical interactions in a multiphase model of pulmonary airway reopening

NASA Astrophysics Data System (ADS)

Yamaguchi, Eiichiro

2010-10-01

We employ micro-particle image velocimetry (μ-PIV) and shadowgraphy to measure the ensemble-averaged fluid-phase velocity field and interfacial geometry during pulsatile bubble propagation that includes a reverse-flow phase under influence of exogenous lung surfactant (Infasurf). Disease states such as respiratory distress syndrome (RDS) are characterized by insufficient pulmonary surfactant concentrations that enhance airway occlusion and collapse. Subsequent airway reopening, driven by mechanical ventilation, may generate damaging stresses that cause ventilator-induced lung injury (VILI). It is hypothesized that reverse flow may enhance surfactant uptake and protect the lung from VILI. The microscale observations conducted in this study will provide us with a significant understanding of dynamic physicochemical interactions that can be manipulated to reduce the magnitude of this damaging mechanical stimulus during airway reopening. Bubble propagation through a liquid-occluded fused glass capillary tube is controlled by linear-motor-driven syringe pumps that provide mean and sinusoidal velocity components. A translating microscope stage mechanically subtracts the mean velocity of the bubble tip in order to hold the progressing bubble tip in the microscope field of view. To optimize the signal-to-noise ratio near the bubble tip, μ-PIV and shadow images are recorded in separate trials then combined during post-processing with help of a custom-designed micro scale marker. Non-specific binding of Infasurf proteins to the channel wall is controlled by oxidation and chemical treatment of the glass surface. The colloidal stability and dynamic/static surface properties of the Infasurf-PIV particle solution are carefully adjusted based on Langmuir trough measurements. The Finite Time Lyapunov Exponent (FTLE) is computed to provide a Lagrangian perspective for comparison with our boundary element predictions.

Modulation of Estrogen Response Element-Driven Gene Expressions and Cellular Proliferation with Polar Directions by Designer Transcription Regulators

PubMed Central

Muyan, Mesut; Güpür, Gizem; Yaşar, Pelin; Ayaz, Gamze; User, Sırma Damla; Kazan, Hasan Hüseyin; Huang, Yanfang

2015-01-01

Estrogen receptor α (ERα), as a ligand-dependent transcription factor, mediates 17β-estradiol (E2) effects. ERα is a modular protein containing a DNA binding domain (DBD) and transcription activation domains (AD) located at the amino- and carboxyl-termini. The interaction of the E2-activated ERα dimer with estrogen response elements (EREs) of genes constitutes the initial step in the ERE-dependent signaling pathway necessary for alterations of cellular features. We previously constructed monomeric transcription activators, or monotransactivators, assembled from an engineered ERE-binding module (EBM) using the ERα-DBD and constitutively active ADs from other transcription factors. Monotransactivators modulated cell proliferation by activating and repressing ERE-driven gene expressions that simulate responses observed with E2-ERα. We reasoned here that integration of potent heterologous repression domains (RDs) into EBM could generate monotransrepressors that alter ERE-bearing gene expressions and cellular proliferation in directions opposite to those observed with E2-ERα or monotransactivators. Consistent with this, monotransrepressors suppressed reporter gene expressions that emulate the ERE-dependent signaling pathway. Moreover, a model monotransrepressor regulated DNA synthesis, cell cycle progression and proliferation of recombinant adenovirus infected ER-negative cells through decreasing as well as increasing gene expressions with polar directions compared with E2-ERα or monotransactivator. Our results indicate that an ‘activator’ or a ‘repressor’ possesses both transcription activating/enhancing and repressing/decreasing abilities within a chromatin context. Offering a protein engineering platform to alter signal pathway-specific gene expressions and cell growth, our approach could also be used for the development of tools for epigenetic modifications and for clinical interventions wherein multigenic de-regulations are an issue. PMID:26295471

Influence of resistant starch and slowly digestible starch on rice texture.

USDA-ARS?s Scientific Manuscript database

Rice, comprised mainly of starch, serves as a significant source of caloric energy world-wide, therefore differences in starch digestibility are important to human health. Rice starch consists of three forms based on digestibility, rapidly digestible starch (RDS), slowly digestible starch (SDS), and...

Personality Dimensions as Assessed by Projective and Verbal Instruments

ERIC Educational Resources Information Center

Rimoldi, H. J.; And Others

1975-01-01

This study aimed to define personality dimensions when assessed by projective and verbal instruments. The Holtzman Inkblot Test was selected to represent projective tests. The 18 scales of the California Personality Inventory (CPI) and the Rokeach Dogmatism Scale (RDS) were the objective tests used. (Author/RK)

Opus in the Classroom: Striking CoRDS with Content-Related Digital Storytelling

ERIC Educational Resources Information Center

Roby, Teshia Young

2010-01-01

Writing personal narratives provides students with additional techniques for making deeper connections to subject matter. Content-related narrative development offers a departure from the traditional methods of teaching and learning and enables students to construe meaning individually and make deeper connections with subject matter content. By…

Registered Dietitians in School Nutrition Leadership: Motivational Aspects of Job Selection and Job Satisfaction

ERIC Educational Resources Information Center

Dodson, Linette J.; Arendt, Susan W.

2014-01-01

Purpose/Objectives: This study examined motivational aspects related to selecting school nutrition leadership as a career by registered dietitians (RDs). Motivational aspects were defined as valued characteristics which influence individuals' desires for specific work environments. Aspects of job satisfaction were also explored. Methods: An online…

On the Importance of Coherence in the Study of Character Development

ERIC Educational Resources Information Center

Callina, Kristina Schmid; Lerner, Richard M.

2017-01-01

Nucci (this issue) gives a compelling conceptualization of the ideas needed to understand character as a multifaceted developmental system. In this article, we focus on the idea of coherence as it applies to understanding character development, education, and assessment. Using ideas from relational developmental systems (RDS) metatheory, we…

Character: A Multifaceted Developmental System

ERIC Educational Resources Information Center

Nucci, Larry

2017-01-01

Character is a developmental system embedded within the self-system. This Relational Developmental Systems (RDS) view is in juxtaposition with virtue theory and accounts of character in terms of moral identity. The character system includes 4 components 3 of which: basic moral cognition (as described within domain theory); other regarding; and…

Complexation of rice starch/flour and maize oil through heat moisture treatment: Structural, in vitro digestion and physicochemical properties.

PubMed

Chen, Xu; He, Xiaowei; Fu, Xiong; Zhang, Bin; Huang, Qiang

2017-05-01

This study investigated structural, in vitro digestion and physicochemical properties of normal rice starch (NRS)/flour (NRF) complexed with maize oil (MO) through heat-moisture treatment (HMT). The NRS-/NRF-MO complex displayed an increased pasting temperature and a decreased peak viscosity. After HMT, less ordered Maltese and more granule fragments were observed for NRS-/NRF-MO complex. Meanwhile, more aggregation was observed in the HMT samples with higher moisture contents. We found that higher onset temperature, lower enthalpy change and relative crystallinity of the NRS-/NRF-MO complex were associated with a higher moisture content of HMT samples. The higher moisture content of HMT was also favorable for the amylose-lipid complex formation. Differences in starch digestion properties were found for NRS-MO and NRF-MO complex. All of the NRS/NRF complexed MO after cooking showed lower rapidly digestible starch (RDS) contents compared with the control sample, therein NRS-/NRF- MO 20% exhibited the highest sum of the slowly digestible starch and resistant starch contents. In general, HMT had a greater impact on the in vitro digestion and physicochemical properties of flour samples compared with starch counterparts. Copyright © 2017 Elsevier B.V. All rights reserved.

Variance Estimation, Design Effects, and Sample Size Calculations for Respondent-Driven Sampling

PubMed Central

2006-01-01

Hidden populations, such as injection drug users and sex workers, are central to a number of public health problems. However, because of the nature of these groups, it is difficult to collect accurate information about them, and this difficulty complicates disease prevention efforts. A recently developed statistical approach called respondent-driven sampling improves our ability to study hidden populations by allowing researchers to make unbiased estimates of the prevalence of certain traits in these populations. Yet, not enough is known about the sample-to-sample variability of these prevalence estimates. In this paper, we present a bootstrap method for constructing confidence intervals around respondent-driven sampling estimates and demonstrate in simulations that it outperforms the naive method currently in use. We also use simulations and real data to estimate the design effects for respondent-driven sampling in a number of situations. We conclude with practical advice about the power calculations that are needed to determine the appropriate sample size for a study using respondent-driven sampling. In general, we recommend a sample size twice as large as would be needed under simple random sampling. PMID:16937083

"It Ruined My Life": The effects of the War on Drugs on people who inject drugs (PWID) in rural Puerto Rico.

PubMed

Abadie, R; Gelpi-Acosta, C; Davila, C; Rivera, A; Welch-Lazoritz, M; Dombrowski, K

2018-01-01

The War on Drugs has raised the incarceration rates of racial minorities for non-violent drug-related crimes, profoundly stigmatized drug users, and redirected resources from drug prevention and treatment to militarizing federal and local law enforcement. Yet, while some states consider shifting their punitive approach to drug use, to one based on drug treatment and rehabilitation, nothing suggests that these policy shifts are being replicated in Puerto Rico. This paper utilizes data from 360 PWID residing in four rural towns in the mountainous area of central Puerto Rico. We initially recruited 315 PWID using respondent-driven sampling (RDS) and collected data about risk practices and conducted HIV and HCV testing. During a second phase, we conducted 34 micro-ethnographic assays, in which we randomly recruited 34 participants from the first phase and included their ego networks in this phase. Our ethnographic inquiry produced significant data regarding the effects of the war on drugs on the local drug trade, drug availability, and injectors' social networks. Findings suggest that repressive policing has been ineffective in preventing drug distribution and use among those in our study. This type of law enforcement approach has resulted in the disproportionate incarceration of poor drug users in rural Puerto Rico, and mainly for nonviolent drug-related crimes. In addition, incarceration exposes PWID to a form of a cruel and unusual punishment: having to quit heroin "cold turkey" while the prison environment also represents a HIV/HCV risk. In turn, the war on drugs not only diverts resources from treatment but also shapes treatment ideologies, punishing non-compliant patients. Shifting the emphasis from repression to treatment and rehabilitation is likely to have a positive impact on the health and overall quality of life of PWID and their communities. Copyright © 2017 Elsevier B.V. All rights reserved.

Perceptions of Health-Related Information on Facebook: Cross-Sectional Study Among Vietnamese Youths

PubMed Central

Zhang, Melvyn WB; Le, Huong Thi; Nguyen, Hinh Duc; Tran, Tho Dinh; Latkin, Carl A; Ho, Roger CM

2017-01-01

Background While health information websites may have previously been the core source of information about health-related conditions on the Internet, social networking sites are increasingly replacing those websites as a source of health-related information. The increasingly popularity of social networking sites among the general population has consequential impact on health policies as well as health-related interventions. To date, there remains a paucity of research conducted in developing countries like Vietnam looking at the influence of social networking sites. Objective Our goal is to establish the baseline use of Facebook among Vietnamese youths and establish their perception of the reliability and usefulness of health-related information that they previously encountered while using the social networking site. Methods An online cross-sectional study was conducted from August 2015 to October 2015. Respondent-driven sampling (RDS) technique was used in the recruitment of participants. Sociodemographic, health status, behaviors, Facebook use and belief of information on Facebook, and interpersonal influence of social network sites were collected via an online structured questionnaire. Results Among 1080 participants, 72.87% (787/1080) reported being interested in health information on Facebook, and 50.74% (548/1080) and 17.50% (189/1080) perceived the information to be reliable and useful, respectively. A total of 10.93% (118/1080) of the participants also reported that they would follow the health advice they obtained from Facebook. Of significance, 7.13% (77/1080) of the participants also reported peer influences on their behavior. Factors that mediate Vietnamese perceptions of the information online include gender, level of perceived stress, age, educational level, and interpersonal influences from Facebook. Conclusions Our study is perhaps one of the first conducted in Vietnam that looks at the relationship between health information on Facebook and factors that might influence young Vietnamese perceptions of the information and the consequential use of that information. PMID:28882813

Measuring altruistic & solidaristic orientations towards others among people who inject drugs

PubMed Central

Friedman, Samuel R.; Pouget, Enrique R.; Sandoval, Milagros; Jones, Yolanda; Nikolopoulos, Georgios; Mateu-Gelabert, Pedro

2015-01-01

Background Past research has found that HIV+ people who inject drugs (PWID) have high levels of consistent condom use in their partnerships with non-IDUs and in other behavioral expressions of what could be altruism or solidarity. Such research on PWID has been hindered by lack of appropriate measures of altruism and solidarity. Yet such measures may help us understand how people who inject drugs react when structural interventions or Big Events such as economic or political crises take place, and thus may also have major implications for HIV and other epidemics. Methods After considerable formative ethnography and pilot testing, we developed scales to assess altruistic and solidaristic orientations towards other drug users and non-drug users. We administered these scales to 300 PWID (56% male; 72% nonwhite; 98% income < $20,000) who were referred to our storefront location by a large respondent-driven sampling (RDS) project. Scale reliabilities were assessed using Cronbach's alpha; scale validity was assessed using Pearson's correlations with criterion variables. Results The 13-item Altruism Scale and the 9-item Solidarity Scale were both internally consistent (alpha = 0.91, 0.83, respectively). Each scale was correlated with how many hours participants help other people, local organizations, or the community in general during an average week (r = 0.33, p < 0.001; and 0.34, p < 0.001, respectively) and with bringing food or other necessities to others after the Hurricane Sandy emergency (r = 0.48, p < 0.001; and 0.41, p < 0.001, respectively). Conclusion These measures seem to be reliable and valid. They can be useful for a variety of studies of PWID and perhaps other people who use drugs. They can help us study both how (and if) Big Events or structural interventions affect altruism and solidarity among PWID and how (and if) altruism and solidarity are associated with changes in HIV or other risks among PWID. PMID:26076380

Presentación del estudio "Links" de hombres que tienes sexo con hombres en Buenos Aires, Argentina.

PubMed

Carballo-Diéguez, Alex; Avila, María M; Balán, Iván C; Marone, Rubén; Pando, María A; Barreda, Victoria

2011-03-01

Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos ("teteras"), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA.

Determinants of hazardous drinking among black South African men who have sex with men.

PubMed

Knox, Justin; Reddy, Vasu; Lane, Tim; Lovasi, Gina; Hasin, Deborah; Sandfort, Theo

2017-11-01

There is a known heavy burden of hazardous drinking and its associated health risks among black South African MSM; however, no study to date has identified risk factors for hazardous drinking among this nor any other African MSM population. A cross-sectional survey was conducted among 480 black South African MSM recruited using respondent-driven sampling. All analyses were adjusted using an RDS II estimator. Multivariable logistic regression was used to assess the relationship between demographic characteristics, psychosocial factors, behavioral attributes and hazardous drinking. More than half of the men (62%, 95%CI=56%-68%) screened positive as hazardous drinkers. In multivariable analyses, living in a township (versus the city of Pretoria) (aOR=1.9, 95%CI=1.2-3.1, p<.01), more gender dysphoria (aOR=1.4, 95%CI=1.0-1.8, p=.03), having ever received money or other incentives in return for sex (aOR=2.4, 95%CI=1.3-4.3, p<.01), having been sexually abused as a child (aOR=2.6, 95%CI=1.1-6.4, p=.03), having anxiety (aOR=5.4, 95%CI=1.2-24.3, p=.03), and social network drinking behavior (aOR=5.4, 95%CI=1.2-24.3, p=.03) were positively associated with hazardous drinking. Being sexually attracted only to men (aOR=0.3, 95%CI=0.1-0.8, p=.01) was negatively associated with hazardous drinking. Hazardous drinking is highly prevalent among black South African MSM. Multiple indicators of social vulnerability were identified as independent determinants of hazardous drinking. These findings are of heightened concern because these health problems often work synergistically to increase risk of HIV infection and should be taken into consideration by efforts aimed at reducing hazardous drinking among this critical population. Copyright © 2017 Elsevier B.V. All rights reserved.

The Parasol Protocol: An Implementation Science Study of HIV Continuum of Care Interventions for Gay Men and Transgender Women in Burma/Myanmar.

PubMed

Wirtz, Andrea L; Naing, Soe; Clouse, Emily; Thu, Kaung Htet; Mon, Sandra Hsu Hnin; Tun, Zin Min; Baral, Stefan; Paing, Aung Zayar; Beyrer, Chris

2017-05-17

Efforts to improve HIV diagnosis and antiretroviral therapy (ART) initiation among people living with HIV and reduce onward transmission of HIV rely on innovative interventions along multiple steps of the HIV care continuum. These innovative methods are particularly important for key populations, including men who have sex with men (MSM) and transgender women (TW). The HIV epidemic in Myanmar is concentrated among key populations, and national efforts now focus on reducing stigma and improving engagement of MSM and TW in HIV prevention and care. This study aims to test the use of several innovations to address losses in the HIV care continuum: (1) use of respondent-driven sampling (RDS) to reach and engage MSM and TW in HIV testing, (2) HIV self-testing (HIVST) to increase HIV testing uptake and aid early diagnosis of infection, (3) community-based CD4 point-of-care (POC) technology to rapidly stage HIV disease for those who are HIV infected, and (4) peer navigation support to increase successful health system navigation for HIV-infected MSM and TW in need of ART or HIV engagement in care. To assess the effect of HIVST, we will implement a randomized trial in which MSM and TW adults in the greater Yangon metropolitan area who are HIV uninfected will be recruited via RDS (N=366). Participants will complete a baseline socio-behavioral survey and will be randomized to standard, voluntary counseling and testing (VCT) or to HIVST. Biologic specimens will be collected during this baseline visit for confirmatory testing using dried blood spots. Participants will be asked to return to the study office to complete a second study visit in which they will report their HIV test result and answer questions on the acceptability of the assigned testing method. Aim 1 participants with confirmed HIV infection and who are not engaged in care (N=49) will be offered direct enrollment into Aims 2 and 3, which include immediate CD4 POC and the option for peer navigation, respectively. Aims 2 and 3 participants will be prospectively followed for 12 months with data collection including interviewer-administered sociobehavioral survey, CD4 POC, and viral load testing occurring biannually. Participants who accept peer navigation will be compared to those who decline peer navigation. Analyses will estimate the impact of CD4 POC on engagement in care and the impact of peer navigation on ART adherence and viral load. Formative qualitative research was conducted in June and September 2015 and led to further refinement of recruitment methods, HIVST instructions and counseling, and peer navigation methods. Aim 1 recruitment began in November 2015 with subsequent enrollment into Aims 2 and 3 and is currently ongoing. These innovative interventions may resolve gaps in the HIV care continuum among MSM and TW and future implementation may aid in curbing the HIV epidemic among MSM and TW in Myanmar. ©Andrea L Wirtz, Soe Naing, Emily Clouse, Kaung Htet Thu, Sandra Hsu Hnin Mon, Zin Min Tun, Stefan Baral, Aung Zayar Paing, Chris Beyrer. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 17.05.2017.

Characteristics of Reading Disability Types in Middle School Students Classified ED

ERIC Educational Resources Information Center

Mattison, Richard E.

2008-01-01

Types of reading disabilities (RD) have not yet been investigated in students classified with emotional disturbance (ED). The prevalence of RD and differentiating characteristics were examined in 118 middle school students attending a self-contained school for ED students by defining RDs with reading standard scores less than 85 on the two…

Reliable Digit Span: A Systematic Review and Cross-Validation Study

ERIC Educational Resources Information Center

Schroeder, Ryan W.; Twumasi-Ankrah, Philip; Baade, Lyle E.; Marshall, Paul S.

2012-01-01

Reliable Digit Span (RDS) is a heavily researched symptom validity test with a recent literature review yielding more than 20 studies ranging in dates from 1994 to 2011. Unfortunately, limitations within some of the research minimize clinical generalizability. This systematic review and cross-validation study was conducted to address these…

77 FR 47874 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-10

... Hospital Historic District (United States Second Generation Veterans Hospitals MPS), 3601 S. 6th Ave... MPS), Bounded by Arrowhead, W. Berry, & S. Manitou Rds., S. Lowell Blvd., Littleton, 12000550 GEORGIA... McDonough County Bailey, William S., House, 100 S. Campbell St., Macomb, 12000553 Winnebago County Greenwood...

The Developmental Course of Supportive Dyadic Coping in Couples

ERIC Educational Resources Information Center

Johnson, Matthew D.; Horne, Rebecca M.; Galovan, Adam M.

2016-01-01

Drawing from a relational developmental systems (RDS) perspective (Lerner, Agans, DeSouza, & Gasca, 2013) and data from 1,427 continuously partnered young adult and midlife mixed-sex couples over the first 5 years of the German Panel Analysis of Intimate Relationships and Family Dynamics (pairfam), this study examined the developmental course…

Evaluation of the Role of Postnatal Ambroxol in the Prevention and Treatment of Respiratory Distress Syndrome in Preterm Neonates

PubMed Central

Elsayed, Hesham F; Elkhaiouby, Muhammed I; Elsharkawey, Sunia M; Elnemr, Muna A

2006-01-01

Objective: to study the effect of the postnatal administration of Ambroxol in the prevention of respiratory distress syndrome in preterm neonates at risk and on the severity of the disease in those neonates already suffering from it. Methods: the study was a randomized clinical trial performed on 120 preterm neonates admitted to the neonatal unit of the Suez Canal University Hospital, Egypt, with gestational age of 28 to 34 weeks. It was performed in the period from September 2001 through March 2003. Half of the enrolled neonates received intravenous ambroxol (20 mg/kg/d), while the control group received the routine management of prematurity and a placebo. Results: Ambroxol decreased the incidence of Respiratory Distress Syndrome (RDS), improved the gas exchange, and decreased Continious Positive Airway pressure (CPAP) pressure, the length of mechanical ventilation and also the mortality rate. Conclusion: the study concluded that Ambroxol reduced the incidence of this disease in preterm neonates at risk of developing it, and improved the clinical course of RDS. PMID:21748134

Novel Mutation in the ATP-Binding Cassette Transporter A3 (ABCA3) Encoding Gene Causes Respiratory Distress Syndrome in A Term Newborn in Southwest Iran

PubMed Central

Rezaei, Farideh; Shafiei, Mohammad; Shariati, Gholamreza; Dehdashtian, Ali; Mohebbi, Maryam; Galehdari, Hamid

2016-01-01

Introduction ABCA3 glycoprotein belongs to the ATP-binding cassette (ABC) superfamily of transporters, which utilize the energy derived from hydrolysis of ATP for the translocation of a wide variety of substrates across the plasma membrane. Mutations in the ABCA3 gene are knowingly causative for fatal surfactant deficiency, particularly respiratory distress syndrome (RDS) in term babies. Case Presentation In this study, Sanger sequencing of the whole ABCA3 gene (NCBI NM_001089) was performed in a neonatal boy with severe RDS. A homozygous mutation has been identified in the patient. Parents were heterozygous for the same missense mutation GGA > AGA at position 202 in exon 6 of the ABCA3 gene (c.604G > A; p.G202R). Furthermore, 70 normal individuals have been analyzed for the mentioned change with negative results. Conclusions Regarding Human Genome Mutation Database (HGMD) and other literature recherche, the detected change is a novel mutation and has not been reported before. Bioinformatics mutation predicting tools prefer it as pathogenic. PMID:27437095

Global synchronization algorithms for the Intel iPSC/860

NASA Technical Reports Server (NTRS)

Seidel, Steven R.; Davis, Mark A.

1992-01-01

In a distributed memory multicomputer that has no global clock, global processor synchronization can only be achieved through software. Global synchronization algorithms are used in tridiagonal systems solvers, CFD codes, sequence comparison algorithms, and sorting algorithms. They are also useful for event simulation, debugging, and for solving mutual exclusion problems. For the Intel iPSC/860 in particular, global synchronization can be used to ensure the most effective use of the communication network for operations such as the shift, where each processor in a one-dimensional array or ring concurrently sends a message to its right (or left) neighbor. Three global synchronization algorithms are considered for the iPSC/860: the gysnc() primitive provided by Intel, the PICL primitive sync0(), and a new recursive doubling synchronization (RDS) algorithm. The performance of these algorithms is compared to the performance predicted by communication models of both the long and forced message protocols. Measurements of the cost of shift operations preceded by global synchronization show that the RDS algorithm always synchronizes the nodes more precisely and costs only slightly more than the other two algorithms.

Causal mediation analysis with a binary outcome and multiple continuous or ordinal mediators: Simulations and application to an alcohol intervention

PubMed Central

Nguyen, Trang Quynh; Webb-Vargas, Yenny; Koning, Ina M.; Stuart, Elizabeth A.

2016-01-01

We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: 1) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, 2) predict potential outcome probabilities, and 3) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance/covariance. We evaluate the estimation of risk-difference- and risk-ratio-based effects (RDs, RRs) using the ML, WLSMV and Bayes estimators in Mplus. Across most variations in path-coefficient and mediator-residual-correlation signs and strengths, and confounding situations investigated, the method performs well with all estimators, but favors ML/WLSMV for RDs with continuous mediators, and Bayes for RRs with ordinal mediators. Bayes outperforms WLSMV/ML regardless of mediator type when estimating RRs with small potential outcome probabilities and in two other special cases. An adolescent alcohol prevention study is used for illustration. PMID:27158217

A partial structural and functional rescue of a retinitis pigmentosa model with compacted DNA nanoparticles.

PubMed

Cai, Xue; Nash, Zack; Conley, Shannon M; Fliesler, Steven J; Cooper, Mark J; Naash, Muna I

2009-01-01

Previously we have shown that compacted DNA nanoparticles can drive high levels of transgene expression after subretinal injection in the mouse eye. Here we delivered compacted DNA nanoparticles containing a therapeutic gene to the retinas of a mouse model of retinitis pigmentosa. Nanoparticles containing the wild-type retinal degeneration slow (Rds) gene were injected into the subretinal space of rds(+/-) mice on postnatal day 5. Gene expression was sustained for up to four months at levels up to four times higher than in controls injected with saline or naked DNA. The nanoparticles were taken up into virtually all photoreceptors and mediated significant structural and biochemical rescue of the disease without histological or functional evidence of toxicity. Electroretinogram recordings showed that nanoparticle-mediated gene transfer restored cone function to a near-normal level in contrast to transfer of naked plasmid DNA. Rod function was also improved. These findings demonstrate that compacted DNA nanoparticles represent a viable option for development of gene-based interventions for ocular diseases and obviate major barriers commonly encountered with non-viral based therapies.

Efficacy of a Low-Cost Bubble CPAP System in Treatment of Respiratory Distress in a Neonatal Ward in Malawi

PubMed Central

Kawaza, Kondwani; Machen, Heather E.; Brown, Jocelyn; Mwanza, Zondiwe; Iniguez, Suzanne; Gest, Al; Smith, E. O'Brian; Oden, Maria; Richards-Kortum, Rebecca R.; Molyneux, Elizabeth

2014-01-01

Background Respiratory failure is a leading cause of neonatal mortality in the developing world. Bubble continuous positive airway pressure (bCPAP) is a safe, effective intervention for infants with respiratory distress and is widely used in developed countries. Because of its high cost, bCPAP is not widely utilized in low-resource settings. We evaluated the performance of a new bCPAP system to treat severe respiratory distress in a low resource setting, comparing it to nasal oxygen therapy, the current standard of care. Methods We conducted a non-randomized convenience sample study to test the efficacy of a low-cost bCPAP system treating newborns with severe respiratory distress in the neonatal ward of Queen Elizabeth Central Hospital, in Blantyre, Malawi. Neonates weighing >1,000 g and presenting with severe respiratory distress who fulfilled inclusion criteria received nasal bCPAP if a device was available; if not, they received standard care. Clinical assessments were made during treatment and outcomes compared for the two groups. Findings 87 neonates (62 bCPAP, 25 controls) were recruited. Survival rate for neonates receiving bCPAP was 71.0% (44/62) compared with 44.0% (11/25) for controls. 65.5% (19/29) of very low birth weight neonates receiving bCPAP survived to discharge compared to 15.4% (1/13) of controls. 64.6% (31/48) of neonates with respiratory distress syndrome (RDS) receiving bCPAP survived to discharge, compared to 23.5% (4/17) of controls. 61.5% (16/26) of neonates with sepsis receiving bCPAP survived to discharge, while none of the seven neonates with sepsis in the control group survived. Interpretation Use of a low-cost bCPAP system to treat neonatal respiratory distress resulted in 27% absolute improvement in survival. The beneficial effect was greater for neonates with very low birth weight, RDS, or sepsis. Implementing appropriate bCPAP devices could reduce neonatal mortality in developing countries. PMID:24489715

Efficacy of a low-cost bubble CPAP system in treatment of respiratory distress in a neonatal ward in Malawi.

PubMed

Kawaza, Kondwani; Machen, Heather E; Brown, Jocelyn; Mwanza, Zondiwe; Iniguez, Suzanne; Gest, Al; O'Brian Smith, E; Oden, Maria; Richards-Kortum, Rebecca R; Molyneux, Elizabeth

2016-09-01

Respiratory failure is a leading cause of neonatal mortality in the developing world. Bubble continuous positive airway pressure (bCPAP) is a safe, effective intervention for infants with respiratory distress and is widely used in developed countries. Because of its high cost, bCPAP is not widely utilized in low-resource settings. We evaluated the performance of a new bCPAP system to treat severe respiratory distress in a low resource setting, comparing it to nasal oxygen therapy, the current standard of care. We conducted a non-randomized convenience sample study to test the efficacy of a low-cost bCPAP system treating newborns with severe respiratory distress in the neonatal ward of Queen Elizabeth Central Hospital, in Blantyre, Malawi. Neonates weighing >1,000 g and presenting with severe respiratory distress who fulfilled inclusion criteria received nasal bCPAP if a device was available; if not, they received standard care. Clinical assessments were made during treatment and outcomes compared for the two groups. 87 neonates (62 bCPAP, 25 controls) were recruited. Survival rate for neonates receiving bCPAP was 71.0% (44/62) compared with 44.0% (11/25) for controls. 65.5% (19/29) of very low birth weight neonates receiving bCPAP survived to discharge compared to 15.4% (1/13) of controls. 64.6% (31/48) of neonates with respiratory distress syndrome (RDS) receiving bCPAP survived to discharge, compared to 23.5% (4/17) of controls. 61.5% (16/26) of neonates with sepsis receiving bCPAP survived to discharge, while none of the seven neonates with sepsis in the control group survived. Use of a low-cost bCPAP system to treat neonatal respiratory distress resulted in 27% absolute improvement in survival. The beneficial effect was greater for neonates with very low birth weight, RDS, or sepsis. Implementing appropriate bCPAP devices could reduce neonatal mortality in developing countries.

Adverse effects of small for gestational age differ by gestational week among very preterm infants.

PubMed

Jensen, Erik A; Foglia, Elizabeth E; Dysart, Kevin C; Simmons, Rebecca A; Aghai, Zubair H; Cook, Alison; Greenspan, Jay S; DeMauro, Sara B

2018-05-05

To characterise the excess risk for death, grade 3-4 intraventricular haemorrhage (IVH), bronchopulmonary dysplasia (BPD) and stage 3-5 retinopathy of prematurity independently associated with birth small for gestational age (SGA) among very preterm infants, stratified by completed weeks of gestation. Retrospective cohort study using the Optum Neonatal Database. Study infants were born <32 weeks gestation without severe congenital anomalies. SGA was defined as a birth weight <10th percentile. The excess outcome risk independently associated with SGA birth among SGA babies was assessed using adjusted risk differences (aRDs). Of 6708 infants sampled from 717 US hospitals, 743 (11.1%) were SGA. SGA compared with non-SGA infants experienced higher unadjusted rates of each study outcome except grade 3-4 IVH among survivors. The excess risk independently associated with SGA birth varied by outcome and gestational age. The highest aRD for death (0.27; 95% CI 0.13 to 0.40) occurred among infants born at 24 weeks gestation and declined as gestational age increased. In contrast, the peak aRDs for BPD among survivors (0.32; 95% CI 0.20 to 0.44) and the composites of death or BPD (0.35; 95% CI 0.24 to 0.46) and death or major morbidity (0.35; 95% CI 0.24 to 0.45) occurred at 27 weeks gestation. The risk-adjusted probability of dying or developing one or more of the evaluated morbidities among SGA infants was similar to that of non-SGA infants born approximately 2-3 weeks less mature. The excess risk for neonatal morbidity and mortality associated with being born SGA varies by adverse outcome and gestational age. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Efficacy of a low-cost bubble CPAP system in treatment of respiratory distress in a neonatal ward in Malawi.

PubMed

Kawaza, Kondwani; Machen, Heather E; Brown, Jocelyn; Mwanza, Zondiwe; Iniguez, Suzanne; Gest, Al; Smith, E O'Brian; Oden, Maria; Richards-Kortum, Rebecca R; Molyneux, Elizabeth

2014-01-01

Respiratory failure is a leading cause of neonatal mortality in the developing world. Bubble continuous positive airway pressure (bCPAP) is a safe, effective intervention for infants with respiratory distress and is widely used in developed countries. Because of its high cost, bCPAP is not widely utilized in low-resource settings. We evaluated the performance of a new bCPAP system to treat severe respiratory distress in a low resource setting, comparing it to nasal oxygen therapy, the current standard of care. We conducted a non-randomized convenience sample study to test the efficacy of a low-cost bCPAP system treating newborns with severe respiratory distress in the neonatal ward of Queen Elizabeth Central Hospital, in Blantyre, Malawi. Neonates weighing >1,000 g and presenting with severe respiratory distress who fulfilled inclusion criteria received nasal bCPAP if a device was available; if not, they received standard care. Clinical assessments were made during treatment and outcomes compared for the two groups. 87 neonates (62 bCPAP, 25 controls) were recruited. Survival rate for neonates receiving bCPAP was 71.0% (44/62) compared with 44.0% (11/25) for controls. 65.5% (19/29) of very low birth weight neonates receiving bCPAP survived to discharge compared to 15.4% (1/13) of controls. 64.6% (31/48) of neonates with respiratory distress syndrome (RDS) receiving bCPAP survived to discharge, compared to 23.5% (4/17) of controls. 61.5% (16/26) of neonates with sepsis receiving bCPAP survived to discharge, while none of the seven neonates with sepsis in the control group survived. Use of a low-cost bCPAP system to treat neonatal respiratory distress resulted in 27% absolute improvement in survival. The beneficial effect was greater for neonates with very low birth weight, RDS, or sepsis. Implementing appropriate bCPAP devices could reduce neonatal mortality in developing countries.

A comparative evaluation of two decompression procedures for technical diving using inflammatory responses: compartmental versus ratio deco.

PubMed

Spisni, Enzo; Marabotti, Claudio; De Fazio, Luigia; Valerii, Maria Chiara; Cavazza, Elena; Brambilla, Stefano; Hoxha, Klarida; L'Abbate, Antonio; Longobardi, Pasquale

2017-03-01

The aim of this study was to compare two decompression procedures commonly adopted by technical divers: the ZH-L16 algorithm modified by 30/85 gradient factors (compartmental decompression model, CDM) versus the 'ratio decompression strategy' (RDS). The comparison was based on an analysis of changes in diver circulating inflammatory profiles caused by decompression from a single dive. Fifty-one technical divers performed a single trimix dive to 50 metres' sea water (msw) for 25 minutes followed by enriched air (EAN50) and oxygen decompression. Twenty-three divers decompressed according to a CDM schedule and 28 divers decompressed according to a RDS schedule. Peripheral blood for detection of inflammatory markers was collected before and 90 min after diving. Venous gas emboli were measured 30 min after diving using 2D echocardiography. Matched groups of 23 recreational divers (dive to 30 msw; 25 min) and 25 swimmers were also enrolled as control groups to assess the effects of decompression from a standard air dive or of exercise alone on the inflammatory profile. Echocardiography at the single 30 min observation post dive showed no significant differences between the two decompression procedures. Divers adopting the RDS showed a worsening of post-dive inflammatory profile compared to the CDM group, with significant increases in circulating chemokines CCL2 (P = 0.001) and CCL5 (P = 0.006) levels. There was no increase in chemokines following the CDM decompression. The air scuba group also showed a statistically significant increase in CCL2 (P < 0.001) and CCL5 (P = 0.003) levels post dive. No cases of decompression sickness occurred. The ratio deco strategy did not confer any benefit in terms of bubbles but showed the disadvantage of increased decompression-associated secretion of inflammatory chemokines involved in the development of vascular damage.

Incidence of respiratory disorders in neonates born between 34 and 36 weeks of gestation following exposure to antenatal corticosteroids between 24 and 34 weeks of gestation.

PubMed

Ventolini, Gary; Neiger, Ran; Mathews, Lindsey; Adragna, Norma; Belcastro, Marc

2008-02-01

We studied the effect of antenatal corticosteroids on the incidence of respiratory disorders in singleton neonates born between 34 and 36 weeks of gestation. Retrospective analysis was conducted of the incidence of respiratory distress syndrome (RDS) and other respiratory disorders (need for mechanical ventilation, continuous positive airway pressure, and prolonged oxygen therapy) among singleton neonates delivered between 34 and 36 weeks of gestation who were exposed to antenatal corticosteroids, compared with neonates who were not exposed. Statistical analyses included two-tailed T tests, two-way analysis of variance for continuous data, and chi-square analysis for ratios. A probability of 0.05 was considered significant. Between January 1, 2000, and December 31, 2004, 1078 neonates were born between 34 and 36 weeks of gestation. Information regarding antenatal corticosteroids was available in 1044: 574 neonates (53.2%) were exposed to antenatal corticosteroids and 470 (43.6%) were not. One thousand and eighteen neonates were admitted to the neonatal intensive care unit. Respiratory disorders were diagnosed in 140 of those exposed to antenatal steroids (24.4%) and in 382 of the nonexposed (81.3%) ( P < 0.0001). Two hundred and ten neonates (20.6%) developed RDS: Of those, 43 were exposed to antenatal corticosteroids and 167 were not (incidence of RDS was 7.5% and 35.5%, respectively; P = 0.0001). The beneficial effects of corticosteroids were similar in both genders. It appears that the exposure of singleton pregnancies to antenatal corticosteroids between 24 and 34 weeks of gestation is associated with a significantly lower incidence of respiratory disorders among neonates born at 34 to 36 weeks of gestation. Further studies are needed to determine whether administering antenatal steroids to women experiencing preterm labor after 34 weeks of gestation would be associated with a similar beneficial effect.

Frequency-Modulated Orocutaneous Stimulation Promotes Non-nutritive Suck Development in Preterm Infants with Respiratory Distress Syndrome or Chronic Lung Disease

PubMed Central

Barlow, Steven M; Lee, Jaehoon; Wang, Jingyan; Oder, Austin; Hall, Sue; Knox, Kendi; Weatherstone, Kathleen; Thompson, Diane

2013-01-01

Background For the premature infant, extrauterine life is a pathological condition which greatly amplifies the challenges to the brain in establishing functional oromotor behaviors. The extent to which suck can be entrained using a synthetically patterned orocutaneous input to promote its development in preterm infants who manifest chronic lung disease is unknown. Objective To evaluate the effects of a frequency-modulated orocutaneous pulse train delivered through a pneumatically-charged pacifier capable of enhancing non-nutritive suck (NNS) activity in tube-fed premature infants. Methods A randomized trial to evaluate the efficacy of pneumatic orocutaneous stimulation 3x/day on NNS development and length of stay (LOS) in the NICU among 160 newborn infants distributed among 3 subpopulations, including healthy preterm infants (HI), respiratory distress syndrome (RDS), and chronic lung disease (CLD). Study infants received a regimen of orocutaneous pulse trains through a PULSED pressurized silicone pacifier or a SHAM control (blind pacifier) during gavage feeds for up to 10 days. Results Mixed modeling, adjusted for the infant’s gender, gestational age, postmenstrual age, and birth weight, was used to handle interdependency among repeated measures within subjects. A significant main effect for stimulation mode (SHAM pacifier vs PULSED orosensory) was found among preterm infants for NNS Bursts/minute (p=.003), NNS events/minute (p=.033), and for Total Oral Compressions/minute [NNS+nonNNS] (p=.016). Pairwise comparison of adjusted means using Bonferroni adjustment indicated RDS and CLD infants showed the most significant gains on these NNS performance indices. CLD infants in the treatment group showed significantly shorter LOS by an average of 2.5 days. Conclusion Frequency-modulated PULSED orocutaneous pulse train stimuli delivered through a silicone pacifier are effective in facilitating NNS burst development in tube-fed RDS and CLD preterm infants, with an added benefit of reduced LOS for CLD infants. PMID:24310444

Bi-level CPAP does not change central blood flow in preterm infants with respiratory distress syndrome.

PubMed

Aquilano, Giulia; Galletti, Silvia; Aceti, Arianna; Vitali, Francesca; Faldella, Giacomo

2014-06-21

Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow. To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support. A prospective study was performed in a cohort of 18 Very-Low-Birth-Weight Infants who were put on nasal CPAP support (4-5 cmH2O) because they developed RDS within the first 24-72 hours of life. Each subject was switched to bi-level CPAP support (Phigh 8 cmH2O, Plow 4-5 cmH2O, Thigh 0.5-0.6 seconds, 20 breaths/min) for an hour. An echocardiographic study and a capillary gas analysis were performed before and after the change of respiratory support. No differences between n-CPAP and bi-level CPAP in left ventricular output (LVO, 222.17 ± 81.4 vs 211.4 ± 75.3 ml/kg/min), right ventricular output (RVO, 287.8 ± 96 vs 283.4 ± 87.4 ml/kg/min) and superior vena cava flow (SVC, 135.38 ± 47.8 vs 137.48 ± 46.6 ml/kg/min) were observed. The hemodynamic characteristics of the ductus arteriosus were similar. A significant decrease in pCO2 levels after bi-level CPAP ventilation was observed; pCO2 variations did not correlate with modifications of central blood flow (LVO: ρ=0.11, p=0,657; RVO: ρ=-0.307, p=0.216; SVC: ρ=-0.13, p=0.197). Central blood flow doesn't change during bi-level CPAP support, which could become a hemodinamically safe tool for the treatment of RDS in preterm infants.

Reward deficiency syndrome in obesity: a preliminary cross-sectional trial with a Genotrim variant.

PubMed

Blum, Kenneth; Chen, Thomas J H; Meshkin, Brian; Downs, B William; Gordon, Cory A; Blum, Seth; Mengucci, Julie F; Braverman, Eric R; Arcuri, Vanessa; Varshavskiy, Michael; Deutsch, Roger; Martinez-Pons, Manuel

2006-01-01

Obesity is the second largest preventable cause of death in the United States. Even though it was classified as a disease in 1985, traditionally, obesity has been treated primarily as a behavioral problem that requires only modifications in diet and exercise. Similar to research on obesity, clinical studies have elucidated the role of biologic and genetic factors in alcoholism and other conditions previously classified as behavioral. These studies showed that behavioral adjustments alone may not address underlying genetic causes. We hypothesize that biologic and genetic factors must be addressed synergistically while behavioral modifications are implemented to adequately treat obese patients. We hypothesize that a predisposition to glucose craving and obesity is due to inadequate dopaminergic activity in the reward center of the brain. This defect drives individuals to engage in activities of behavioral excess, which, in turn, enhance brain dopamine function. Consumption of large quantities of alcohol or carbohydrates (carbohydrate bingeing) stimulates production and usage of dopamine within the brain; the term reward deficiency syndrome (RDS) may be used to categorize such biologic influences on behavior. We propose that a novel approach to nutritional supplementation may be required to target the role of RDS in obesity. In this regard, GenoTrim, a DNA-customized nutritional solution, has been developed and is currently under investigation in several clinical studies. Through its mechanism of action, GenoTrim addresses the genetic influence of RDS on obesity. In this cross-sectional study, 24 subjects were studied after they had completed a case report format questionnaire. For this assessment, we used a novel assessment tool-a path analysis. This statistical regression model is used to (1) examine the effectual relationships between various systems within a multisystem matrix, and (2) measure the contributory roles of those relationships in obesity, enabling the development of targeted and effective therapeutic interventions.

Frequency-modulated orocutaneous stimulation promotes non-nutritive suck development in preterm infants with respiratory distress syndrome or chronic lung disease.

PubMed

Barlow, S M; Lee, J; Wang, J; Oder, A; Hall, S; Knox, K; Weatherstone, K; Thompson, D

2014-02-01

For the premature infant, extrauterine life is a pathological condition, which greatly amplifies the challenges to the brain in establishing functional oromotor behaviors. The extent to which suck can be entrained using a synthetically patterned orocutaneous input to promote its development in preterm infants who manifest chronic lung disease (CLD) is unknown. The objective of this study was to evaluate the effects of a frequency-modulated (FM) orocutaneous pulse train delivered through a pneumatically charged pacifier capable of enhancing non-nutritive suck (NNS) activity in tube-fed premature infants. A randomized trial to evaluate the efficacy of pneumatic orocutaneous stimulation 3 × per day on NNS development and length of stay (LOS) in the neonatal intensive care unit among 160 newborn infants distributed among three sub-populations, including healthy preterm infants, respiratory distress syndrome (RDS) and CLD. Study infants received a regimen of orocutaneous pulse trains through a PULSED pressurized silicone pacifier or a SHAM control (blind pacifier) during gavage feeds for up to 10 days. Mixed modeling, adjusted for the infant's gender, gestational age, postmenstrual age and birth weight, was used to handle interdependency among repeated measures within subjects. A significant main effect for stimulation mode (SHAM pacifier vs PULSED orosensory) was found among preterm infants for NNS bursts per min (P=0.003), NNS events per min (P=0.033) and for total oral compressions per min (NNS+nonNNS) (P=0.016). Pairwise comparison of adjusted means using Bonferroni adjustment indicated RDS and CLD infants showed the most significant gains on these NNS performance indices. CLD infants in the treatment group showed significantly shorter LOS by an average of 2.5 days. FM PULSED orocutaneous pulse train stimuli delivered through a silicone pacifier are effective in facilitating NNS burst development in tube-fed RDS and CLD preterm infants, with an added benefit of reduced LOS for CLD infants.

A model of gene expression based on random dynamical systems reveals modularity properties of gene regulatory networks.

PubMed

Antoneli, Fernando; Ferreira, Renata C; Briones, Marcelo R S

2016-06-01

Here we propose a new approach to modeling gene expression based on the theory of random dynamical systems (RDS) that provides a general coupling prescription between the nodes of any given regulatory network given the dynamics of each node is modeled by a RDS. The main virtues of this approach are the following: (i) it provides a natural way to obtain arbitrarily large networks by coupling together simple basic pieces, thus revealing the modularity of regulatory networks; (ii) the assumptions about the stochastic processes used in the modeling are fairly general, in the sense that the only requirement is stationarity; (iii) there is a well developed mathematical theory, which is a blend of smooth dynamical systems theory, ergodic theory and stochastic analysis that allows one to extract relevant dynamical and statistical information without solving the system; (iv) one may obtain the classical rate equations form the corresponding stochastic version by averaging the dynamic random variables (small noise limit). It is important to emphasize that unlike the deterministic case, where coupling two equations is a trivial matter, coupling two RDS is non-trivial, specially in our case, where the coupling is performed between a state variable of one gene and the switching stochastic process of another gene and, hence, it is not a priori true that the resulting coupled system will satisfy the definition of a random dynamical system. We shall provide the necessary arguments that ensure that our coupling prescription does indeed furnish a coupled regulatory network of random dynamical systems. Finally, the fact that classical rate equations are the small noise limit of our stochastic model ensures that any validation or prediction made on the basis of the classical theory is also a validation or prediction of our model. We illustrate our framework with some simple examples of single-gene system and network motifs. Copyright © 2016 Elsevier Inc. All rights reserved.

Topologically-associating domains are stable units of replication-timing regulation

PubMed Central

Pope, Benjamin D.; Ryba, Tyrone; Dileep, Vishnu; Yue, Feng; Wu, Weisheng; Denas, Olgert; Vera, Daniel L.; Wang, Yanli; Hansen, R. Scott; Canfield, Theresa K.; Thurman, Robert E.; Cheng, Yong; Gülsoy, Günhan; Dennis, Jonathan H.; Snyder, Michael P.; Stamatoyannopoulos, John A.; Taylor, James; Hardison, Ross C.; Kahveci, Tamer; Ren, Bing; Gilbert, David M.

2014-01-01

Summary Eukaryotic chromosomes replicate in a temporal order known as the replication-timing program1. During mammalian development, at least half the genome changes replication timing, primarily in units of 400–800 kb (“replication domains”; RDs), whose positions are preserved in different cell types, conserved between species, and appear to confine long-range effects of chromosome rearrangements2–7. Early and late replication correlate strongly with open and closed chromatin compartments identified by high-resolution chromosome conformation capture (Hi-C), and, to a lesser extent, lamina-associated domains (LADs)4,5,8,9. Recent Hi-C mapping has unveiled a substructure of topologically-associating domains (TADs) that are largely conserved in their positions between cell types and are similar in size to RDs8,10. However, TADs can be further sub-stratified into smaller domains, challenging the significance of structures at any particular scale11,12. Moreover, attempts to reconcile TADs and LADs to replication-timing data have not revealed a common, underlying domain structure8,9,13. Here, we localize boundaries of RDs to the early-replicating border of replication-timing transitions and map their positions in 18 human and 13 mouse cell types. We demonstrate that, collectively, RD boundaries share a near one-to-one correlation with TAD boundaries, whereas within a cell type, adjacent TADs that replicate at similar times obscure RD boundaries, largely accounting for the previously reported lack of alignment. Moreover, cell-type specific replication timing of TADs partitions the genome into two large-scale sub-nuclear compartments revealing that replication-timing transitions are indistinguishable from late-replicating regions in chromatin composition and lamina association and accounting for the reduced correlation of replication timing to LADs and heterochromatin. Our results reconcile cell type specific sub-nuclear compartmentalization with developmentally stable chromosome domains and offer a unified model for large-scale chromosome structure and function. PMID:25409831

[Measurement of the passive compliance of the total respiratory system in newborn after respiratory insufficiency for risk assessment of respiratory disorders during the first 6 month of life].

PubMed

Olechowski, Wiesław; Majorek-Olechowska, Bernadetta

2010-01-01

To evaluate the relationships between postnatal passive respiratory compliance (Crs) and development of respiratory disorders during the first 6 month of life in preterm and full-term infants after respiratory insufficiency. The purpose of this study was to investigate whether other relevant neonatal factors, like degree of prematurity, birth weigh, ventilatory conditions, sepsis, and respiratory disease severity affected this relationship. The passive respiratory compliance was measured by the single occlusion technique in 73 preterm infants after respiratory distress syndrome (RDS), 19 full-term infants after congenital pneumonia and 33 healthy full-term infants. Respiratory function measurements were performed by single occlusion technique, during natural sleep, after acute phase of illness, before discharge from neonatal department. Crs was significantly lower in premature newborns < 36 weeks gestation after RDS (p = 0.0002) and in term newborns who have suffered from a congenital pneumonia (p = 0.0411), than in healthy full-term newborn infants. Premature infants who have undergone sepsis have significantly decreased Crs in relationship with those who did not have this complication (p = 0.0334). Preterm newborns who have suffered pneumonia during treatment of RDS have significantly frequent respiratory problems during the first 6 month of age (p = 0.043). Full-term infants after congenital pneumonia have more but not significantly frequent respiratory problems than healthy term newborns (p = 0.055) in this period. Decreased neonatal Crs wasn't significantly related to respiratory disorders in age of 6 month of life. Prematurity under 36 week of gestational age, low birth weight and suffering from sepsis in premature infants significantly decreased Crs in newborn. Decreased neonatal Crs in premature and full term infants after respiratory insufficiency wasn't significantly related to respiratory disorders during first 6 month of life. This study has showed significantly increase of respiratory problems in this period in preterm infants who have suffered from pneumonia during neonatal period.

PET/MRI for Oncologic Brain Imaging: A Comparison of Standard MR-Based Attenuation Corrections with a Model-Based Approach for the Siemens mMR PET/MR System.

PubMed

Rausch, Ivo; Rischka, Lucas; Ladefoged, Claes N; Furtner, Julia; Fenchel, Matthias; Hahn, Andreas; Lanzenberger, Rupert; Mayerhoefer, Marius E; Traub-Weidinger, Tatjana; Beyer, Thomas

2017-09-01

The aim of this study was to compare attenuation-correction (AC) approaches for PET/MRI in clinical neurooncology. Methods: Forty-nine PET/MRI brain scans were included: brain tumor studies using 18 F-fluoro-ethyl-tyrosine ( 18 F-FET) ( n = 31) and 68 Ga-DOTANOC ( n = 7) and studies of healthy subjects using 18 F-FDG ( n = 11). For each subject, MR-based AC maps (MR-AC) were acquired using the standard DIXON- and ultrashort echo time (UTE)-based approaches. A third MR-AC was calculated using a model-based, postprocessing approach to account for bone attenuation values (BD, noncommercial prototype software by Siemens Healthcare). As a reference, AC maps were derived from patient-specific CT images (CTref). PET data were reconstructed using standard settings after AC with all 4 AC methods. We report changes in diagnosis for all brain tumor patients and the following relative differences values (RDs [%]), with regards to AC-CTref: for 18 F-FET (A)-SUVs as well as volumes of interest (VOIs) defined by a 70% threshold of all segmented lesions and lesion-to-background ratios; for 68 Ga-DOTANOC (B)-SUVs as well as VOIs defined by a 50% threshold for all lesions and the pituitary gland; and for 18 F-FDG (C)-RD of SUVs of the whole brain and 10 anatomic regions segmented on MR images. Results: For brain tumor imaging (A and B), the standard PET-based diagnosis was not affected by any of the 3 MR-AC methods. For A, the average RDs of SUV mean were -10%, -4%, and -3% and of the VOIs 1%, 2%, and 7% for DIXON, UTE, and BD, respectively. Lesion-to-background ratios for all MR-AC methods were similar to that of CTref. For B, average RDs of SUV mean were -11%, -11%, and -3% and of the VOIs 1%, -4%, and -3%, respectively. In the case of 18 F-FDG PET/MRI (C), RDs for the whole brain were -11%, -8%, and -5% for DIXON, UTE, and BD, respectively. Conclusion: The diagnostic reading of PET/MR patients with brain tumors did not change with the chosen AC method. Quantitative accuracy of SUVs was clinically acceptable for UTE- and BD-AC for group A, whereas for group B BD was in accordance with CTref. Nevertheless, for the quantification of individual lesions large deviations to CTref can be observed independent of the MR-AC method used. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Effects of Repetitive, Small-Spot, Incoherent Light Flashes on Pursuit Tracking Performance.

DTIC Science & Technology

1984-06-01

P) USA; David .1I. lund. BS _ 10. PRGRAM ELEMENT PROJECT, TASK 9. PERFORMING ORGANIZATION NAME AND ADDRESS AREA a WORK UNIT NUMBERS Letterman Army...short period. ’. What risks or hasards can be reasonably antici pated? . What steps will he taken to prevent or minimize these risks or hai-,rds? Not

Author's Response to Commentaries on: "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics"

ERIC Educational Resources Information Center

Molenaar, Peter C. M.

2015-01-01

In this article, Peter Molenaar responds to three commentaries (this issue) on his article, "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics." He addresses aspects of relational developmental systems (RDS) mentioned and questions raised in each of the…

Factors associated with HIV testing among male injecting drug users: findings from a cross-sectional behavioural and biological survey in Manipur and Nagaland, India.

PubMed

Ganju, Deepika; Ramesh, Sowmya; Saggurti, Niranjan

2016-06-21

Although targeted interventions in India require all high-risk groups, including injecting drug users (IDUs), to test for HIV every 6 months, testing uptake among IDUs remains far from universal. Our study estimates the proportion of IDUs who have taken an HIV test and identifies the factors associated with HIV testing uptake in Nagaland and Manipur, two high HIV prevalence states in India where the epidemic is driven by injecting drug use. Data are drawn from the cross-sectional Integrated Behavioural and Biological Assessment (2009) of 1650 male IDUs from two districts each of Manipur and Nagaland. Participants were recruited using respondent-driven sampling (RDS). Descriptive data were analysed using RDSAT 7.1. Multivariate logistic regression analysis was undertaken using STATA 11 to examine the association between HIV testing and socio-demographic, behavioural and programme exposure variables. One third of IDUs reported prior HIV testing, of whom 8 % had tested HIV-positive. Among those without prior testing, 6.2 % tested HIV-positive in the current survey. IDUs aged 25-34 years (adjusted odds ratio (OR) = 1.41; 95 % confidence interval (CI) = 1.03-1.93), married (Adjusted OR = 1.56; 95 % CI = 1.15-2.12), had a paid sexual partner (Adjusted OR = 1.64; 95 % CI = 1.24-2.18), injected drugs for more than 36 months (Adjusted OR = 1.38; 95 % CI = 1.06-1.81), injected frequently (Adjusted OR = 1.49; 95 % CI = 1.12-1.98) and had high-risk perception (Adjusted OR = 1.68; 95 % CI = 1.32-2.14) were more likely than others to test for HIV. Compared to those with no programme exposure, IDUs who received counselling, or counselling and needle/syringe services, were more likely to test for HIV. HIV testing uptake among IDUs is low in Manipur and Nagaland, and a critical group of HIV-positive IDUs who have never tested for HIV are being missed by current programmes. This study identifies key sub-groups-including early initiators, short duration and less frequent injectors, perceived to be at low risk-for promoting HIV testing. Providing needles/syringes alone is not adequate to increase HIV testing; additionally, interventions must provide counselling services to inform all IDUs about HIV testing benefits, facilitate visits to testing centres and link those testing positive to timely treatment and care.

Sample Size Calculations for Population Size Estimation Studies Using Multiplier Methods With Respondent-Driven Sampling Surveys.

PubMed

Fearon, Elizabeth; Chabata, Sungai T; Thompson, Jennifer A; Cowan, Frances M; Hargreaves, James R

2017-09-14

While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions. To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained. The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe. There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater. We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey. ©Elizabeth Fearon, Sungai T Chabata, Jennifer A Thompson, Frances M Cowan, James R Hargreaves. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 14.09.2017.

Consequences of Childhood Reading Difficulties and Behaviour Problems for Educational Achievement and Employment in Early Adulthood

ERIC Educational Resources Information Center

Smart, Diana; Youssef, George J.; Sanson, Ann; Prior, Margot; Toumbourou, John W.; Olsson, Craig A.

2017-01-01

Background: Reading difficulties (RDs) and behaviour problems (BPs) are two common childhood problems that have a high degree of stability and often negatively affect well-being in both the short and longer terms. Aims: The study aimed to shed light on the unique and joint consequences of these two childhood problems for educational and…

A Systematic Review of Research into Rare Diseases in the Educational Sphere

ERIC Educational Resources Information Center

Darretxe, Leire; Gaintza, Zuriñe; Monzon-Gonzalez, Javier

2017-01-01

Rare diseases (RDs) represent a wide, varied group of illnesses characterised by their low prevalence among the population. Moreover, they can appear at any time of life, including in infancy. For this reason, the aim of this article was to review and analyse research in the field of education to find out what kind of educational response is…

The Influence of Self-Efficacies on Readers' Intention to Use E-Reading Devices: An Empirical Study

ERIC Educational Resources Information Center

Tsai, Bor-Yuan; Yen, Jung-Nan

2014-01-01

E-books and e-Reading Devices (E-RDs) markets have been enlarged due to the rapid progress of digital technologies. What are the possible factors to increase readers' willingness to use electronic devices? To improve the predictive value of the original TAM model, this study incorporates three additional constructs to form e-Reading Device…

Exposure to fine particulate matter during pregnancy and risk of preterm birth among women in New Jersey, Ohio, and Pennsylvania, 2000-2005

EPA Science Inventory

BACKGROUND: Particulate matter ≤ 2.5 um in aerodynamic diameter (PM2.5) has been variably associated with preterm birth (PTB). • OBJECTIVE: We classified PTB into four categories (20-27, 28-31, 32-34, and 35-36 weeks completed gestation) and estimated risk differences (RDs) f...

Incidence and correlates of HIV and syphilis in a prospective cohort of men who have sex with men in Mianyang, China, over a 36-month period.

PubMed

Wang, Yi; Huang, Yuling; Chen, Huailiang; Li, Liulin; Xu, Jie; Li, Zhijun; Zhang, Guanggui; Fan, Jing; Zhao, Xihe; Jia, Shuguang

2015-11-01

Background Estimates for the HIV/AIDS epidemic from the China Ministry of Health show that the epidemic is spreading rapidly among men who have sex with men (MSM). Respondent-driven sampling (RDS) was adapted in 2009 and snowball sampling was adapted to supplement the number of participants in 2010 and 2011. Interviewer-administered questionnaires and blood tests were conducted to confirm enrolment eligibility of participants. A total of 725 HIV-negative participants were included into the cohort study. The cohort had a HIV incidence density of 5.6 (95% CI: 3.9-7.3)/100 person-years (PY) and a syphilis incidence density of 5.6 (95% CI:3.7-7.6)/100 PY. Age ≤20 years (21-25 years, hazard ratio (HR)=0.32, 95%CI: 0.11-0.95/≥26 years, HR=0.17, 95%CI: 0.05-0.66), having not participated in peer education in the past year (HR=2.96, 95%CI: 1.19-7.35), seeking male sexual partners in a public washroom/park (HR=3.61, 95%CI: 1.03-12.47), being currently infected with syphilis (HR=3.21, 95%CI: 1.31-7.91), having sex partners aged ≥30 years (HR=3.40, 95%CI: 1.11-10.39) and having more than four male sexual partners within the past 6 months (HR=3.34, 95%CI: 1.24-9.04) were found to be risk factors for HIV seroconversion (each P<0.05). Being married (HR=2.38, 95%CI: 1.04-5.46), having not participated in peer education in the past year (HR=2.28, 95%CI: 1.08-4.82), having limited HIV/AIDS knowledge (HR=4.28, 95%CI: 1.94-9.43) and having a sexually transmitted disease infection in the past 6 months (HR=4.74, 95%CI: 1.83-12.30) were identified as factors for syphilis infection (each P<0.05). The incidence rates of HIV and syphilis in Mianyang City reamained high in the cohort of MSM for 36 months. Increased attention should be given to this serious epidemic, and appropriate interventions should be implemented to address MSM-specific issues in order to prevent HIV and syphilis infection in China.

Matching and correlation computations in stereoscopic depth perception.

PubMed

Doi, Takahiro; Tanabe, Seiji; Fujita, Ichiro

2011-03-02

A fundamental task of the visual system is to infer depth by using binocular disparity. To encode binocular disparity, the visual cortex performs two distinct computations: one detects matched patterns in paired images (matching computation); the other constructs the cross-correlation between the images (correlation computation). How the two computations are used in stereoscopic perception is unclear. We dissociated their contributions in near/far discrimination by varying the magnitude of the disparity across separate sessions. For small disparity (0.03°), subjects performed at chance level to a binocularly opposite-contrast (anti-correlated) random-dot stereogram (RDS) but improved their performance with the proportion of contrast-matched (correlated) dots. For large disparity (0.48°), the direction of perceived depth reversed with an anti-correlated RDS relative to that for a correlated one. Neither reversed nor normal depth was perceived when anti-correlation was applied to half of the dots. We explain the decision process as a weighted average of the two computations, with the relative weight of the correlation computation increasing with the disparity magnitude. We conclude that matching computation dominates fine depth perception, while both computations contribute to coarser depth perception. Thus, stereoscopic depth perception recruits different computations depending on the disparity magnitude.

Application of Probabilistic Methods for the Determination of an Economically Robust HSCT Configuration

NASA Technical Reports Server (NTRS)

Mavris, Dimitri N.; Bandte, Oliver; Schrage, Daniel P.

1996-01-01

This paper outlines an approach for the determination of economically viable robust design solutions using the High Speed Civil Transport (HSCT) as a case study. Furthermore, the paper states the advantages of a probability based aircraft design over the traditional point design approach. It also proposes a new methodology called Robust Design Simulation (RDS) which treats customer satisfaction as the ultimate design objective. RDS is based on a probabilistic approach to aerospace systems design, which views the chosen objective as a distribution function introduced by so called noise or uncertainty variables. Since the designer has no control over these variables, a variability distribution is defined for each one of them. The cumulative effect of all these distributions causes the overall variability of the objective function. For cases where the selected objective function depends heavily on these noise variables, it may be desirable to obtain a design solution that minimizes this dependence. The paper outlines a step by step approach on how to achieve such a solution for the HSCT case study and introduces an evaluation criterion which guarantees the highest customer satisfaction. This customer satisfaction is expressed by the probability of achieving objective function values less than a desired target value.

A review and guidance for pattern selection in spatiotemporal system

NASA Astrophysics Data System (ADS)

Wang, Chunni; Ma, Jun

2018-03-01

Pattern estimation and selection in media can give important clues to understand the collective response to external stimulus by detecting the observable variables. Both reaction-diffusion systems (RDs) and neuronal networks can be treated as multi-agent systems from molecular level, intrinsic cooperation, competition. An external stimulus or attack can cause collapse of spatial order and distribution, while appropriate noise can enhance the consensus in the spatiotemporal systems. Pattern formation and synchronization stability can bridge isolated oscillators and the network by coupling these nodes with appropriate connection types. As a result, the dynamical behaviors can be detected and discussed by developing different spatial patterns and realizing network synchronization. Indeed, the collective response of network and multi-agent system depends on the local kinetics of nodes and cells. It is better to know the standard bifurcation analysis and stability control schemes before dealing with network problems. In this review, dynamics discussion and synchronization control on low-dimensional systems, pattern formation and synchronization stability on network, wave stability in RDs and neuronal network are summarized. Finally, possible guidance is presented when some physical effects such as polarization field and electromagnetic induction are considered.

Modelling cell motility and chemotaxis with evolving surface finite elements

PubMed Central

Elliott, Charles M.; Stinner, Björn; Venkataraman, Chandrasekhar

2012-01-01

We present a mathematical and a computational framework for the modelling of cell motility. The cell membrane is represented by an evolving surface, with the movement of the cell determined by the interaction of various forces that act normal to the surface. We consider external forces such as those that may arise owing to inhomogeneities in the medium and a pressure that constrains the enclosed volume, as well as internal forces that arise from the reaction of the cells' surface to stretching and bending. We also consider a protrusive force associated with a reaction–diffusion system (RDS) posed on the cell membrane, with cell polarization modelled by this surface RDS. The computational method is based on an evolving surface finite-element method. The general method can account for the large deformations that arise in cell motility and allows the simulation of cell migration in three dimensions. We illustrate applications of the proposed modelling framework and numerical method by reporting on numerical simulations of a model for eukaryotic chemotaxis and a model for the persistent movement of keratocytes in two and three space dimensions. Movies of the simulated cells can be obtained from http://homepages.warwick.ac.uk/∼maskae/CV_Warwick/Chemotaxis.html. PMID:22675164

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, II, Barry; Schrader, Robert L.; Kowalski, Karol

The longest-wavelength π-to-π* electronic excitations of rhodamine-like dyes (RDs) with different group16 heteroatoms (O, S, Se, Te) have been investigated. Time-dependent Kohn–Sham theory (TDKST) calculations were compared with coupled-cluster (CC) and equations-of-motion (EOM) CC results for π-to-π* singlet and triplet excitations. The RDs exhibit characteristics in the TDKST calculations that are very similar to previously investigated cyanine dyes, in the sense that the singlet energies obtained with nonhybrid functionals are too high compared with the CC results at the SD(T) level. The errors became increasingly larger for functionals with increasing amounts of exact exchange. TDKST with all tested functionals ledmore » to severe underestimations of the corresponding triplet excitations and overestimations of the singlet--triplet gaps. Long-range-corrected range-separated exchange and "optimal tuning" of the range separation parameter did not significantly improve the TDKST results. A detailed analysis suggests that the problem is differential electron correlation between the ground and excited states, which is not treated sufficiently by the relatively small integrals over the exchange-correlation response kernel that enters the excitation energy expression. As a result, numerical criteria are suggested that may help identify "cyanine-like" problems in TDKST calculations of excitation spectra.« less

Reactive documentation system

NASA Astrophysics Data System (ADS)

Boehnlein, Thomas R.; Kramb, Victoria

2018-04-01

Proper formal documentation of computer acquired NDE experimental data generated during research is critical to the longevity and usefulness of the data. Without documentation describing how and why the data was acquired, NDE research teams lose capability such as their ability to generate new information from previously collected data or provide adequate information so that their work can be replicated by others seeking to validate their research. Despite the critical nature of this issue, NDE data is still being generated in research labs without appropriate documentation. By generating documentation in series with data, equal priority is given to both activities during the research process. One way to achieve this is to use a reactive documentation system (RDS). RDS prompts an operator to document the data as it is generated rather than relying on the operator to decide when and what to document. This paper discusses how such a system can be implemented in a dynamic environment made up of in-house and third party NDE data acquisition systems without creating additional burden on the operator. The reactive documentation approach presented here is agnostic enough that the principles can be applied to any operator controlled, computer based, data acquisition system.

3D CFD Simulation of Plug Dynamics and Splitting through a Bifurcating Airway Model

NASA Astrophysics Data System (ADS)

Hoi, Cory; Raessi, Mehdi

2017-11-01

Respiratory distress syndrome (RDS) occurs because of pulmonary surfactant insufficiency in the lungs of preterm infants. The common medical procedure to treat RDS, called surfactant respiratory therapy (SRT), involves instilling liquid surfactant plugs into the pulmonary airways. SRT's effectiveness highly depends on the ability to deliver surfactant through the complex branching airway network. Experimental and computational efforts have been made to understand complex fluid dynamics of liquid plug motion through the lung airways in order to increase SRT's response rate. However, previous computational work used 2D airway model geometries and studied plug dynamics of a pre-split plug. In this work, we present CFD simulations of surfactant plug motion through a 3D bifurcating airway model. In our 3D y-tube geometry representing the lung airways, we are not limited by 2D or pre-split plug assumptions. The airway walls are covered with a pre-existing liquid film. Using a passive scalar marking the surfactant plug, the plug splitting and surfactant film deposition is studied under various airway orientations. Exploring the splitting process and liquid distribution in a 3D geometry will advance our understanding of surfactant delivery and will increase the effectiveness of SRT.

Users, Uses, and Effects of Social Media in Dietetic Practice: Scoping Review of the Quantitative and Qualitative Evidence.

PubMed

Dumas, Audrée-Anne; Lapointe, Annie; Desroches, Sophie

2018-02-20

Social media platforms are increasingly used by registered dietitians (RDs) to improve knowledge translation and exchange in nutrition. However, a thorough understanding of social media in dietetic practice is lacking. The objective of this study was to map and summarize the evidence about the users, uses, and effects of social media in dietetic practice to identify gaps in the literature and inform future research by using a scoping review methodology. Stages for conducting the scoping review included the following: (1) identifying the research question; (2) identifying relevant studies through a comprehensive multidatabase and gray literature search strategy; (3) selecting eligible studies; (4) charting the data; and (5) collating, summarizing, and reporting results for dissemination. Finally, knowledge users (RDs working for dietetic professional associations and public health organizations) were involved in each review stage to generate practical findings. Of the 47 included studies, 34 were intervention studies, 4 were descriptive studies, 2 were content analysis studies, and 7 were expert opinion papers in dietetic practice. Discussion forums were the most frequent social media platform evaluated (n=19), followed by blogs (n=13) and social networking sites (n=10). Most studies targeted overweight and obese or healthy users, with adult populations being most studied. Social media platforms were used to deliver content as part of larger multiple component interventions for weight management. Among intervention studies using a control group with no exposition to social media, we identified positive, neutral, and mixed effects of social media for outcomes related to users' health behaviors and status (eg, dietary intakes and body weight), participation rates, and professional knowledge. Factors associated with the characteristics of the specific social media, such as ease of use, a design for quick access to desired information, and concurrent reminders of use, were perceived as the main facilitators to the use of social media in dietetic practice, followed to a lesser extent by interactions with an RD and social support from fellow users. Barriers to social media use were mostly related to complicated access to the site and time issues. Research on social media in dietetic practice is at its infancy, but it is growing fast. So far, this field of research has targeted few social media platforms, most of which were assessed in multiple-component interventions for weight management among overweight or obese adults. Trials isolating the effects and mechanisms of action of specific social media platforms are needed to draw conclusions regarding the effectiveness of those tools to support dietetic practice. Future studies should address barriers and facilitators related to the use of social media written by RDs and should explore how to make these tools useful for RDs to reach health consumers to improve health through diet. ©Audrée-Anne Dumas, Annie Lapointe, Sophie Desroches. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 20.02.2018.

Users, Uses, and Effects of Social Media in Dietetic Practice: Scoping Review of the Quantitative and Qualitative Evidence

PubMed Central

2018-01-01

Background Social media platforms are increasingly used by registered dietitians (RDs) to improve knowledge translation and exchange in nutrition. However, a thorough understanding of social media in dietetic practice is lacking. Objective The objective of this study was to map and summarize the evidence about the users, uses, and effects of social media in dietetic practice to identify gaps in the literature and inform future research by using a scoping review methodology. Methods Stages for conducting the scoping review included the following: (1) identifying the research question; (2) identifying relevant studies through a comprehensive multidatabase and gray literature search strategy; (3) selecting eligible studies; (4) charting the data; and (5) collating, summarizing, and reporting results for dissemination. Finally, knowledge users (RDs working for dietetic professional associations and public health organizations) were involved in each review stage to generate practical findings. Results Of the 47 included studies, 34 were intervention studies, 4 were descriptive studies, 2 were content analysis studies, and 7 were expert opinion papers in dietetic practice. Discussion forums were the most frequent social media platform evaluated (n=19), followed by blogs (n=13) and social networking sites (n=10). Most studies targeted overweight and obese or healthy users, with adult populations being most studied. Social media platforms were used to deliver content as part of larger multiple component interventions for weight management. Among intervention studies using a control group with no exposition to social media, we identified positive, neutral, and mixed effects of social media for outcomes related to users’ health behaviors and status (eg, dietary intakes and body weight), participation rates, and professional knowledge. Factors associated with the characteristics of the specific social media, such as ease of use, a design for quick access to desired information, and concurrent reminders of use, were perceived as the main facilitators to the use of social media in dietetic practice, followed to a lesser extent by interactions with an RD and social support from fellow users. Barriers to social media use were mostly related to complicated access to the site and time issues. Conclusions Research on social media in dietetic practice is at its infancy, but it is growing fast. So far, this field of research has targeted few social media platforms, most of which were assessed in multiple-component interventions for weight management among overweight or obese adults. Trials isolating the effects and mechanisms of action of specific social media platforms are needed to draw conclusions regarding the effectiveness of those tools to support dietetic practice. Future studies should address barriers and facilitators related to the use of social media written by RDs and should explore how to make these tools useful for RDs to reach health consumers to improve health through diet. PMID:29463487

Losartan prevents the imbalance between renal dopaminergic and renin angiotensin systems induced by fructose overload. L-dopa/dopamine index as new potential biomarker of renal dysfunction.

PubMed

Mikusic, Natalia Lucía Rukavina; Kouyoumdzian, Nicolás Martín; Uceda, Ana; Del Mauro, Julieta Sofía; Pandolfo, Marcela; Gironacci, Mariela Mercedes; Puyó, Ana María; Toblli, Jorge Eduardo; Fernández, Belisario Enrique; Choi, Marcelo Roberto

2018-05-01

The renin angiotensin system (RAS) and the renal dopaminergic system (RDS) act as autocrine and paracrine systems to regulate renal sodium management and inflammation and their alterations have been associated to hypertension and renal damage. Nearly 30-50% of hypertensive patients have insulin resistance (IR), with a strong correlation between hyperinsulinemia and microalbuminuria. The aim of this study was to demonstrate the existence of an imbalance between RAS and RDS associated to IR, hypertension and kidney damage induced by fructose overload (FO), as well as to establish their prevention, by pharmacological inhibition of RAS with losartan. Ninety-six male Sprague-Dawley rats were randomly divided into four groups and studied at 4, 8 and 12 weeks: control group (C4, C8 and C12; tap water to drink); fructose-overloaded group (F4, F8 and F12; 10% w/v fructose solution to drink); losartan-treated control (L) group (L4, L8 and L12; losartan 30 mg/kg/day, in drinking water); and fructose-overloaded plus losartan group (F + L4, F + L8 and F + L12, in fructose solution). FO induced metabolic and hemodynamic alterations as well as an imbalance between RAS and RDS, characterized by increased renal angiotensin II levels and AT 1 R overexpression, reduced urinary excretion of dopamine, increased excretion of L-dopa (increased L-dopa/dopamine index) and down-regulation of D 1 R and tubular dopamine transporters OCT-2, OCT-N1 and total OCTNs. This imbalance was accompanied by an overexpression of renal tubular Na + , K + -ATPase, pro-inflammatory (NF-kB, TNF-α, IL-6) and pro-fibrotic (TGF-β1 and collagen) markers and by renal damage (microalbuminuria and reduced nephrin expression). Losartan prevented the metabolic and hemodynamic alterations induced by FO from week 4. Increased urinary L-dopa/dopamine index and decreased D 1 R renal expression associated to FO were also prevented by losartan since week 4. The same pattern was observed for renal expression of OCTs/OCTNs, Na + , K + -ATPase, pro-inflammatory and pro-fibrotic markers from week 8. The appearance of microalbuminuria and reduced nephrin expression was prevented by losartan at week 12. The results of this study provide new insight regarding the mechanisms by which a pro-hypertensive and pro-inflammatory system, such as RAS, downregulates another anti-hypertensive and anti-inflammatory system such as RDS. Additionally, we propose the use of L-dopa/dopamine index as a biochemical marker of renal dysfunction in conditions characterized by sodium retention, IR and/or hypertension, and as a predictor of response to treatment and follow-up of these processes. Copyright © 2018. Published by Elsevier Inc.

Stress-Driven Melt Segregation and Organization in Partially Molten Rocks III: Annealing Experiments and Surface Tension-Driven Redistribution of Melt

NASA Astrophysics Data System (ADS)

Parsons, R.; Hustoft, J. W.; Holtzman, B. K.; Kohlstedt, D. L.; Phipps Morgan, J.

2004-12-01

As discussed in the two previous abstracts in this series, simple shear experiments on synthetic upper mantle-type rock samples reveal the segregation of melt into melt-rich bands separated by melt-depleted lenses. Here, we present new results from experiments designed to understand the driving forces working for and against melt segregation. To better understand the kinetics of surface tension-driven melt redistribution, we first deform samples at similar conditions (starting material, sample size, stress and strain) to produce melt-rich band networks that are statistically similar. Then the load is removed and the samples are statically annealed to allow surface tension to redistribute the melt-rich networks. Three samples of olivine + 20 vol% chromite + 4 vol% MORB were deformed at a confining pressure of 300 MPa and a temperature of 1523 K in simple shear at shear stresses of 20 - 55 MPa to shear strains of 3.5 and then statically annealed for 0, 10, or 100 h at the same P-T conditions. Melt-rich bands are fewer in number and appear more diffuse when compared to the deformed but not annealed samples. Bands with less melt tend to disappear more rapidly than more melt-rich ones. The melt fraction in the melt-rich bands decreased from 0.2 in the quenched sample to 0.1 in the sample annealed for 100 h. After deformation, the melt fraction in the melt-depleted regions are ~0.006; after static annealing for 100 h, this value increases to 0.02. These experiments provide new quantitative constraints on the kinetics of melt migration driven by surface tension. By quantifying this driving force in the same samples in which stress-driven distribution occurred, we learn about the relative kinetics of stress-driven melt segregation. The kinetics of both of these processes must be scaled together to mantle conditions to understand the importance of stress-driven melt segregation in the Earth, and to understand the interaction of this process with melt-rock reaction-driven processes.

Comparison of sampling methods for hard-to-reach francophone populations: yield and adequacy of advertisement and respondent-driven sampling.

PubMed

Ngwakongnwi, Emmanuel; King-Shier, Kathryn M; Hemmelgarn, Brenda R; Musto, Richard; Quan, Hude

2014-01-01

Francophones who live outside the primarily French-speaking province of Quebec, Canada, risk being excluded from research by lack of a sampling frame. We examined the adequacy of random sampling, advertising, and respondent-driven sampling for recruitment of francophones for survey research. We recruited francophones residing in the city of Calgary, Alberta, through advertising and respondentdriven sampling. These 2 samples were then compared with a random subsample of Calgary francophones derived from the 2006 Canadian Community Health Survey (CCHS). We assessed the effectiveness of advertising and respondent-driven sampling in relation to the CCHS sample by comparing demographic characteristics and selected items from the CCHS (specifically self-reported general health status, perceived weight, and having a family doctor). We recruited 120 francophones through advertising and 145 through respondent-driven sampling; the random sample from the CCHS consisted of 259 records. The samples derived from advertising and respondentdriven sampling differed from the CCHS in terms of age (mean ages 41.0, 37.6, and 42.5 years, respectively), sex (proportion of males 26.1%, 40.6%, and 56.6%, respectively), education (college or higher 86.7% , 77.9% , and 59.1%, respectively), place of birth (immigrants accounting for 45.8%, 55.2%, and 3.7%, respectively), and not having a regular medical doctor (16.7%, 34.5%, and 16.6%, respectively). Differences were not tested statistically because of limitations on the analysis of CCHS data imposed by Statistics Canada. The samples generated exclusively through advertising and respondent-driven sampling were not representative of the gold standard sample from the CCHS. Use of such biased samples for research studies could generate misleading results.

Defense Logistics: DOD Needs to Take Additional Actions to Address Challenges in Supply Chain Management

DTIC Science & Technology

2011-07-01

Jack E. Edwa appendix III. t rds Director, Defense Capabilities and Managemen Page 36 GAO-11-569 Defense Logistics List of Committees...Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302... operations . DOD faces asset visibility challenges due, in part, to a lack of interoperability among information technology

U. S. Naval Forces, Vietnam Monthly Historical Supplement for September 1969

DTIC Science & Technology

1969-12-01

A. SEAI.O)RDS - lISEP B. 5A,•f lORDS - 22 SEP,.". I *A "’\\4 5.: SCALl , CA MAU POINT _ __0 NAUTICAL MILES CG 41 POULO77.BASE 08I -I ".-il - v-CC...Cambodia. (See discussion of Border Interdiction Capaign within Operation SIA LOIDS Suwzary and discussion of SEA FLOAT in Coastal Surreillanoe 4 Tore

Malingering in Toxic Exposure. Classification Accuracy of Reliable Digit Span and WAIS-III Digit Span Scaled Scores

ERIC Educational Resources Information Center

Greve, Kevin W.; Springer, Steven; Bianchini, Kevin J.; Black, F. William; Heinly, Matthew T.; Love, Jeffrey M.; Swift, Douglas A.; Ciota, Megan A.

2007-01-01

This study examined the sensitivity and false-positive error rate of reliable digit span (RDS) and the WAIS-III Digit Span (DS) scaled score in persons alleging toxic exposure and determined whether error rates differed from published rates in traumatic brain injury (TBI) and chronic pain (CP). Data were obtained from the files of 123 persons…

Resin duct size and density as ecophysiological traits in fire scars of Pseudotsuga menziesii and Larix occidentalis

Treesearch

Estelle Arbellay; Markus Stoffel; Elaine K. Sutherland; Kevin T. Smith; Donald A. Falk

2014-01-01

Resin ducts (RDs) are features present in most conifer species as defence structures against pests and pathogens; however, little is known about RD expression in trees following fire injury. This study investigates changes in RD size and density in fire scars of Douglas fir (Pseudotsuga menziesii) and western larch (Larix occidentalis) as a means to evaluate the...

The Drug Overdose Epidemic and Deceased-Donor Transplantation in the United States: A National Registry Study.

PubMed

Durand, Christine M; Bowring, Mary G; Thomas, Alvin G; Kucirka, Lauren M; Massie, Allan B; Cameron, Andrew; Desai, Niraj M; Sulkowski, Mark; Segev, Dorry L

2018-05-15

The epidemic of drug overdose deaths in the United States has led to an increase in organ donors. To characterize donors who died of overdose and to analyze outcomes among transplant recipients. Prospective observational cohort study. Scientific Registry of Transplant Recipients, 1 January 2000 to 1 September 2017. 138 565 deceased donors; 337 934 transplant recipients at 297 transplant centers. The primary exposure was donor mechanism of death (overdose-death donor [ODD], trauma-death donor [TDD], or medical-death donor [MDD]). Patient and graft survival and organ discard (organ recovered but not transplanted) were compared using propensity score-weighted standardized risk differences (sRDs). A total of 7313 ODDs and 19 897 ODD transplants (10 347 kidneys, 5707 livers, 2471 hearts, and 1372 lungs) were identified. Overdose-death donors accounted for 1.1% of donors in 2000 and 13.4% in 2017. They were more likely to be white (85.1%), aged 21 to 40 years (66.3%), infected with hepatitis C virus (HCV) (18.3%), and increased-infectious risk donors (IRDs) (56.4%). Standardized 5-year patient survival was similar for ODD organ recipients compared with TDD organ recipients (sRDs ranged from 3.1% lower to 3.9% higher survival) and MDD organ recipients (sRDs ranged from 2.1% to 5.2% higher survival). Standardized 5-year graft survival was similar between ODD and TDD grafts (minimal difference for kidneys and lungs, marginally lower [sRD, -3.2%] for livers, and marginally higher [sRD, 1.9%] for hearts). Kidney discard was higher for ODDs than TDDs (sRD, 5.2%) or MDDs (sRD, 1.5%); standardization for HCV and IRD status attenuated this difference. Inability to distinguish between opioid and nonopioid overdoses. In the United States, transplantation with ODD organs has increased dramatically, with noninferior outcomes in transplant recipients. Concerns about IRD behaviors and hepatitis C among donors lead to excess discard that should be minimized given the current organ shortage. National Institutes of Health.

Status Report for Remediation Decision Support Project, Task 1, Activity 1.B – Physical and Hydraulic Properties Database and Interpretation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rockhold, Mark L.

2008-09-26

The objective of Activity 1.B of the Remediation Decision Support (RDS) Project is to compile all available physical and hydraulic property data for sediments from the Hanford Site, to port these data into the Hanford Environmental Information System (HEIS), and to make the data web-accessible to anyone on the Hanford Local Area Network via the so-called Virtual Library. In past years efforts were made by RDS project staff to compile all available physical and hydraulic property data for Hanford sediments and to transfer these data into SoilVision{reg_sign}, a commercial geotechnical software package designed for storing, analyzing, and manipulating soils data.more » Although SoilVision{reg_sign} has proven to be useful, its access and use restrictions have been recognized as a limitation to the effective use of the physical and hydraulic property databases by the broader group of potential users involved in Hanford waste site issues. In order to make these data more widely available and useable, a decision was made to port them to HEIS and to make them web-accessible via a Virtual Library module. In FY08 the objectives of Activity 1.B of the RDS Project were to: (1) ensure traceability and defensibility of all physical and hydraulic property data currently residing in the SoilVision{reg_sign} database maintained by PNNL, (2) transfer the physical and hydraulic property data from the Microsoft Access database files used by SoilVision{reg_sign} into HEIS, which has most recently been maintained by Fluor-Hanford, Inc., (3) develop a Virtual Library module for accessing these data from HEIS, and (4) write a User's Manual for the Virtual Library module. The development of the Virtual Library module was to be performed by a third party under subcontract to Fluor. The intent of these activities is to make the available physical and hydraulic property data more readily accessible and useable by technical staff and operable unit managers involved in waste site assessments and remedial action decisions for Hanford. This status report describes the history of this development effort and progress to date.« less

Addiction Treatment in America: After Money or Aftercare?

PubMed

Miller, David; Miller, Merlene; Blum, Kenneth; Badgaiyan, Rajendra D; Febo, Marcelo

2015-10-21

There are approximately 14,500 clinics and programs in America that provide treatment for all types of addictive behaviors we call "Reward Deficiency Syndrome (RDS)". While most of these have good intentions to provide needed help to the victims of RDS, we propose herein that most of their efforts, especially during periods of aftercare, are not based on the existing scientific evidence. We use "aftercare" to refer to any form of program or therapy following primary treatment including 12-Step programs. Very few programs actually provide any evidenced-based treatment approaches during this most vulnerable period in recovery. In this trieste we are suggesting that a hypodopaminergic trait (genetic) and/or state (epigenetic) is critical in terms of continued motivation to use/abuse of alcohol or other drugs and can lead to relapse. While there is evidence for the approved FDA drugs to treat drug addiction (e.g. alcohol, opiates, nicotine) these drugs favor a short-term benefit by blocking dopamine. We argue instead for the utilization of long-term benefits that induce "dopamine homeostasis", or in simpler terms "normalcy". We suggest that this could be accomplished through a number of holistic modalities including, but not limited to, dopamine-boosting diets, hyper-oxygenation, heavy metal detoxification, exercise, meditation, yoga, and most importantly, brain neurotransmitter balancing with nutraceuticals such as KB220 variants. We embrace 12-step programs and fellowships but not as a stand-alone modality, especially during aftercare. We also provide some scientific basis for why resting state functional connectivity (rsfMRI) is so important and may be the cornerstone in terms of how to treat RDS. We postulate that since drugs, food, smoking, gambling, and even compulsive sexual behavior could reduce rsfMRI then modalities (following required research), that can restore this impaired cross talk between various brain regions (e.g. Nucleus accumbens, cingulate gyrus, hippocampus etc.) should be incorporated into the aftercare plan in all treatment programs in America. Anything less will ultimately lead to the so called "revolving door" for as many as 90% of treatment participants.

Randomized controlled trial of two methods of nasal continuous positive airway pressure (N-CPAP) in preterm infants with respiratory distress syndrome: underwater bubbly CPAP vs. Medijet system device.

PubMed

Hosseini, Mohammad Bagher; Heidarzadeh, Mohammad; Balila, Masumeh; Ghojazadeh, Morteza; Janani, Raheleh; Safavi-nia, Sima; Naghavi-Behzad, Mohammad; Alikhah, Hossein

2012-01-01

There has been an increasing interest in the application of non-invasive respiratory support in preterm infants, and different types of nasal continuous positive airway pressure (N-CPAP) devices are being used in Neonatal Intensive Care Units (NICUs). The objective of the present study was to compare the duration of CPAP need and possible complications of two methods of (N-CPAP) delivery: Bubble CPAP (B-CPAP) and Medijet (MJ) system device in preterm infants with respiratory distress syndrome (RDS). This prospective randomized clinical trial was performed on 161 preterm infants (28-37 weeks of gestational age) with RDS and eligible for CPAP therapy. The infants were inborn and admitted in a level III NICU of Al-Zahra Teaching Hospital (Tabriz, Iran) from April 2010 to September 2011. All infants were randomized in the first hour of life to B-CPAP or MJ system. Short binasal prongs were used in both groups and CPAP was set at the level of 5-6 cm H2O. The primary outcome of this study was duration of CPAP need (hour). Other outcomes, such as complications of the two methods of N-CPAP, were evaluated using a checklist. Ninety infants were randomized to the MJ system, and 71 were randomized to B-CPAP. The mean gestational age and birth weight were similar in the two groups, as was the duration of CPAP need (44.3 ± 20.64 vs. 49.2 ± 21.2 hours, respectively; p=0.66). Moreover, the probability of complications, such as CPAP failure rate, pulmonary hemorrhage, pneumothorax, intraventricular hemorrhage, abdominal distention, necrotizing enterocolitis, and bronchopulmonary dysplasia, was the same between the two study groups (p>0.05). There was a trend of more hyperemia of the nose in the B-CPAP group in comparison to the MJ system group (10% versus 3.3%, respectively), but the difference was not significant (p=0.08). In conclusion, the MJ system is as effective as B-CPAP in the management of infants with RDS.

Bi-level CPAP does not change central blood flow in preterm infants with respiratory distress syndrome

PubMed Central

2014-01-01

Background Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow. Objective To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support. Design A prospective study was performed in a cohort of 18 Very-Low-Birth-Weight Infants who were put on nasal CPAP support (4–5 cmH2O) because they developed RDS within the first 24–72 hours of life. Each subject was switched to bi-level CPAP support (Phigh 8 cmH2O, Plow 4–5 cmH2O, Thigh 0.5-0.6 seconds, 20 breaths/min) for an hour. An echocardiographic study and a capillary gas analysis were performed before and after the change of respiratory support. Results No differences between n-CPAP and bi-level CPAP in left ventricular output (LVO, 222.17 ± 81.4 vs 211.4 ± 75.3 ml/kg/min), right ventricular output (RVO, 287.8 ± 96 vs 283.4 ± 87.4 ml/kg/min) and superior vena cava flow (SVC, 135.38 ± 47.8 vs 137.48 ± 46.6 ml/kg/min) were observed. The hemodynamic characteristics of the ductus arteriosus were similar. A significant decrease in pCO2 levels after bi-level CPAP ventilation was observed; pCO2 variations did not correlate with modifications of central blood flow (LVO: ρ = 0.11, p = 0,657; RVO: ρ = −0.307, p = 0.216; SVC: ρ = −0.13, p = 0.197). Conclusions Central blood flow doesn’t change during bi-level CPAP support, which could become a hemodinamically safe tool for the treatment of RDS in preterm infants. PMID:24952579

Routine application of lung ultrasonography in the neonatal intensive care unit

PubMed Central

Chen, Shui-Wen; Fu, Wei; Liu, Jing; Wang, Yan

2017-01-01

Abstract The aim of this study was to study the features of lung ultrasonography (LUS) in lung disease and to evaluate the usefulness of LUS in the neonatal intensive care unit (NICU). All of 3405 neonates included in this study underwent an LUS examination. Diagnoses were based on medical history, clinical manifestation, laboratory examination, and signs on chest radiography (CR) and/or computed tomography (CT). A single expert physician performed all LUS examinations. There were 2658 cases (78.9%) with lung disease and 747 cases (21.9%) without lung disease. The main signs of neonates with lung disease on LUS were as follows: absence of A-lines, pleural-line abnormalities, interstitial syndrome, lung consolidation, air bronchograms, pulmonary edema, and lung pulse. These abnormal signs were reduced or eliminated on LUS as patient conditions improved. There were 81 cases that could not be diagnosed as lung disease by CR but were discovered as pneumonia, respiratory distress syndrome (RDS), or transient tachypnea of newborn (TTN) on LUS. Likewise, 23 cases misdiagnosed as RDS by CR were diagnosed as TTN on LUS. Among 212 cases of long-term oxygen dependence (LTOD) that failed to yield signs of pulmonary edema and lung consolidation on CR, 103 cases showed abnormal signs on LUS. Among 747 cases without lung disease, B-lines of 713 neonates (95.4%) could be found within 3 days after birth, and 256 neonates (34.3%) could be observed from 3 days to 1 week after birth. B-lines of 19 cases could be detected from 1 to 2 weeks after birth. The longest time at which B-lines could still be observed was 19 days after birth. LUS has clinical value for the diagnosis of lung disease and the discrimination of causes of LTOP in premature infants, particularly for the diagnosis and identification of RDS and TTN. Moreover, LUS has additional advantages, including its lack of radiation exposure and its ability to noninvasively monitor treatment progress. Therefore, LUS should be routinely used in the NICU. PMID:28079811

Isolation and partial characterization of starch from banana cultivars grown in Colombia.

PubMed

Chávez-Salazar, A; Bello-Pérez, L A; Agama-Acevedo, E; Castellanos-Galeano, F J; Álvarez-Barreto, C I; Pacheco-Vargas, G

2017-05-01

Banana starch is resistant to hydrolysis by digestive enzymes due to its structure and dietary fibre content. Starch was isolated from the following three cultivars of Colombian Musaceae: Gros Michel (dessert), Dominico Harton and FHIA 20 (cooking); also, the amylose and amylopectin contents, morphology of the granules, thermal properties, pasting, molecular characteristics and digestibility were determined. The total starch content, amylose content and digestibility (gelatinized starch) were higher in cooking varieties; the purity and gelatinization temperature were similar for the three varieties, but the enthalpy was higher in the dessert variety. The three varieties showed higher viscosities in the pasting profile compared to commercial maize starch in both acid and neutral conditions. Starch granules presented with heterogeneous sizes and shapes (elongated and ovals) that had birefringence. The Dominico Hartón variety showed the lowest rapidly digestible starch (RDS) value in the gelatinized sample that is in agreement with the greater proportion of long chains. Copyright © 2017 Elsevier B.V. All rights reserved.

Ethical Considerations in HIV/AIDS Biobehavioral Surveys That Use Respondent-Driven Sampling: Illustrations From Lebanon

PubMed Central

DeJong, Jocelyn; Mahfoud, Ziyad; Khoury, Danielle; Barbir, Farah

2009-01-01

Respondent-driven sampling is especially useful for reaching hidden populations and is increasingly used internationally in public health research, particularly on HIV. Respondent-driven sampling involves peer recruitment and has a dual-incentive structure: both recruiters and their peer recruits are paid. Recent literature focusing on the ethical dimensions of this method in the US context has identified integral safeguards that protect against ethical violations. We analyzed a study of 3 groups in Lebanon who are at risk for HIV (injection drug users, men who have sex with men, female sex workers) and the ethical issues that arose. More explicit attention should be given to ethical issues involved in research implementing respondent-driven sampling of at-risk populations in developing countries, where ethical review mechanisms may be weak. PMID:19608961

User-driven sampling strategies in image exploitation

NASA Astrophysics Data System (ADS)

Harvey, Neal; Porter, Reid

2013-12-01

Visual analytics and interactive machine learning both try to leverage the complementary strengths of humans and machines to solve complex data exploitation tasks. These fields overlap most significantly when training is involved: the visualization or machine learning tool improves over time by exploiting observations of the human-computer interaction. This paper focuses on one aspect of the human-computer interaction that we call user-driven sampling strategies. Unlike relevance feedback and active learning sampling strategies, where the computer selects which data to label at each iteration, we investigate situations where the user selects which data is to be labeled at each iteration. User-driven sampling strategies can emerge in many visual analytics applications but they have not been fully developed in machine learning. User-driven sampling strategies suggest new theoretical and practical research questions for both visualization science and machine learning. In this paper we identify and quantify the potential benefits of these strategies in a practical image analysis application. We find user-driven sampling strategies can sometimes provide significant performance gains by steering tools towards local minima that have lower error than tools trained with all of the data. In preliminary experiments we find these performance gains are particularly pronounced when the user is experienced with the tool and application domain.

Identification and Quantification of Hydrocarbon Products in Effluents.

DTIC Science & Technology

1980-05-01

Tobyhanna Army Depot ATTN: Const. Mgmt. Br. Jacksonville Tooele Army Depot ATTN: Engr. Library Japan Watervliet Arsenal Jidda Yuma Proving Ground Chief...the prepared standard series were stored in volumetric flasks sealed with latex caps over ground glass stoppers. Absorption spectra of the standa-rds in...Facilities Engineer Walter Reed Army Medical Center ATTN: DAEN-CW ARRADCOM ATIN: DAEN-RM Aberdeen Proving Ground USACC ATTN: DAEN-CCP Army Matis. and Mechanics

Concurrent Programming Using Actors: Exploiting Large-Scale Parallelism,

DTIC Science & Technology

1985-10-07

ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK* Artificial Inteligence Laboratory AREA Is WORK UNIT NUMBERS 545 Technology Square...D-R162 422 CONCURRENT PROGRMMIZNG USING f"OS XL?ITP TEH l’ LARGE-SCALE PARALLELISH(U) NASI AC E Al CAMBRIDGE ARTIFICIAL INTELLIGENCE L. G AGHA ET AL...RESOLUTION TEST CHART N~ATIONAL BUREAU OF STANDA.RDS - -96 A -E. __ _ __ __’ .,*- - -- •. - MASSACHUSETTS INSTITUTE OF TECHNOLOGY ARTIFICIAL