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Introduction: Adolescent girls and young women (AGYW) aged 15–24 years and adolescent boys and young men (ABYM) aged 15–34 years represent one of the populations at highest risk for HIV-infection in South Africa. The National Department of Health adopted the universal test and treat (UTT) strategy in 2016, resulting in increases in same-day antiretroviral therapy initiations and linkage to care. Monitoring progress towards attainment of South Africa's 95-95-95 targets amongst AGYW and ABYM relies on high quality data to identify and address gaps in linkage to care. The aim of this study is to describe the current approaches for engaging AGYW and ABYM in the treatment continuum to generate knowledge that can guide efforts to improve linkage to, and retention in, HIV care among these populations in KwaZulu-Natal, South Africa. Methods and analysis: This is a mixed methods study, which will be conducted in uMgungundlovu district of KwaZulu-Natal, over a 24-month period, in 22 purposively selected HIV testing and treatment service delivery points (SDPs). For the quantitative component, a sample of 1100 AGYW aged 15–24 years and ABYM aged 15–35 years old will be recruited into the study, in addition to 231 healthcare providers (HCPs) involved in the implementation of the UTT program. The qualitative component will include 30 participating patients who were successfully linked to care, 30 who were not, and 30 who have never tested for HIV. Key informant interviews will also be conducted with 24 HCPs. Logistic regression will be used to model the primary outcomes on SDP types, while a time to event analysis will be conducted using a Cox regression model and adjusting the standard errors of the hazard ratio for the clustering of participants within SDPs. For qualitative data, a general inductive approach of analysis will be used. Dissemination: Findings from the study will be communicated to the study population and results will be presented to stakeholders and at appropriate local and international conferences. Outputs will also include a policy brief, peer reviewed journal articles and research capacity building through research degrees. [ABSTRACT FROM AUTHOR]

Wastewater treatment plant (WWTP) effluents alter water chemistry and in-stream nutrient uptake rates of receiving freshwaters, thus changing the magnitude and fate of the nutrients exported. In Mediterranean regions, the dilution capacity of receiving streams can vary strongly over time due to the seasonal occurrence of floods and droughts, causing temporal variability of nutrient uptake. We assessed the temporal patterns and the controlling factors of net nutrient uptake in an intermittent Mediterranean stream receiving WWTP effluent inputs. We compiled the longitudinal concentration profiles of ambient dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) along a 800 m reach on 47 sampling dates between 2001 and 2017, encompassing a wide range of hydrological conditions. We estimated net nutrient uptake in the receiving stream. In 72% of the dates, high rates of net ammonium uptake co-occurred with net releases of either nitrate or nitrite. This pattern suggests that the receiving stream has a high nitrification capacity. Conversely, 75% of the dates did not show any longitudinal pattern in SRP concentration, suggesting that uptake and release processes for this element were either counterbalanced or both occurred at very low rates. Finally, net ammonium uptake was low when the stream had a low dilution capacity (< 40%) and ammonium concentration was high. Overall, we demonstrate that consideration of the receiving stream's dilution capacity is imperative to the management of freshwaters to guarantee an adequate dilution of WWTP effluent inputs and avoid saturation of in-stream nutrient uptake capacity under low flow conditions in urban landscapes. [ABSTRACT FROM AUTHOR]

Introduction: Pre-exposure prophylaxis (PrEP) is an effective prevention intervention that can be used to control HIV incidence especially among people who are at increased risk for HIV such as adolescent girls and young women (AGYW) and adolescent boys and young men (ABYM). In South Africa, various approaches of delivering PrEP have been adopted at different service delivery points (facility-based only, school-based only, community-based only and hybrid school-facility and community-facility models) to overcome challenges associated with individual, structural, and health systems related barriers that may hinder access to and uptake of PrEP among these populations. However, little is known about how to optimize PrEP implementation and operational strategies to achieve high sustained uptake of good quality services for AGYW and ABYM. This study aims to identify effective and feasible PrEP models of care for improving PrEP uptake, continuation, and adherence among AGYW and ABYM. Methods and analysis: A sequential explanatory mixed-methods study will be conducted in 22 service delivery points (SDPs) in uMgungundlovu district, KwaZulu-Natal, South Africa. We will recruit 600 HIV negative, sexually active, high risk, AGYW (aged 15–24 years) and ABYM (aged 15–35 years). Enrolled participants will be followed up at 1-, 4- and 7-months to determine continuation and adherence to PrEP. We will conduct two focus group discussions (with 8 participants in each group) across four groups (i. Initiated PrEP within 1 month, ii. Did not initiate PrEP within 1 month, iii. Continued PrEP at 4/7 months and iv. Did not continue PrEP at 4/7 months) and 48 in-depth interviews from each of the four groups (12 per group). Twelve key informant interviews with stakeholders working in HIV programs will also be conducted. Associations between demographic characteristics stratified by PrEP initiation and by various service-delivery models will be assessed using Chi-square/Fishers exact tests or t-test/Mann Whitney test. A general inductive approach will be used to analyze the qualitative data. Ethics and dissemination: The protocol was approved by the South African Medical Research Council Health Research Ethics Committee (EC051-11/2020). Findings from the study will be communicated to the study population and results will be presented to stakeholders and at appropriate local and international conferences. Outputs will also include a policy brief, peer-reviewed journal articles and research capacity building through research degrees. [ABSTRACT FROM AUTHOR]

Hyporheic zones increase freshwater ecosystem resilience to hydrological extremes and global environmental change. However, current conceptualizations of hyporheic exchange, residence time distributions, and the associated biogeochemical cycling in streambed sediments do not always accurately explain the hydrological and biogeochemical complexity observed in streams and rivers. Specifically, existing conceptual models insufficiently represent the coupled transport and reactivity along groundwater and surface water flow paths, the role of autochthonous organic matter in streambed biogeochemical functioning, and the feedbacks between surface‐subsurface ecological processes, both within and across spatial and temporal scales. While simplified approaches to these issues are justifiable and necessary for transferability, the exclusion of important hyporheic processes from our conceptualizations can lead to erroneous conclusions and inadequate understanding and management of interconnected surface water and groundwater environments. This is particularly true at the landscape scale, where the organizational principles of spatio‐temporal dynamics of hyporheic exchange flow (HEF) and biogeochemical processes remain largely uncharacterized. This article seeks to identify the most important drivers and controls of HEF and biogeochemical cycling based on a comprehensive synthesis of findings from a wide range of river systems. We use these observations to test current paradigms and conceptual models, discussing the interactions of local‐to‐regional hydrological, geomorphological, and ecological controls of hyporheic zone functioning. This improved conceptualization of the landscape organizational principles of drivers of HEF and biogeochemical processes from reach to catchment scales will inform future river research directions and watershed management strategies. Key Points: The complexity of HZ rivers and controls exceeds the range of conditions considered in previous conceptualizations and model formulationsUnderstanding organizational principles of hyporheic exchange flow (HEF) and biogeochemical cycling in landscapes is key for generalizing process knowledgeLocal HEF, metabolism, and biogeochemical cycling are embedded within the larger context of fluvial and terrestrial ecosystem structure [ABSTRACT FROM AUTHOR]

Background: The impact of comorbid disease states on the development of atrial and ventricular arrhythmias in patients with hypertrophic cardiomyopathy (HCM) remains unresolved. Objective: Evaluate the association of comorbidities linked to arrhythmias in other cardiovascular diseases (e.g., obesity, systemic hypertension, diabetes, obstructive sleep apnea, renal disorders, tobacco, and alcohol use) to atrial fibrillation (AF) and sudden cardiac death (SCD) events in a large cohort of HCM patients. Methods: A total of 2269 patients, 54 ± 15 years of age, 1392 males, were evaluated at the Tufts HCM Institute between 2004 and 2018 and followed for an average of 4 ± 3 years for new‐onset clinical AF and SCD events (appropriate defibrillation for ventricular tachyarrhythmias, resuscitated cardiac arrest, or SCD). Results: One or more comorbidity was present in 75% of HCM patients, including 50% with ≥2 comorbidities, most commonly obesity (body mass index [BMI] ≥ 30 kg/m2) in 43%. New‐onset atrial fibrillation developed in 11% of our cohort (2.6%/year). On univariate analysis, obesity was associated with a 1.7‐fold increased risk for AF (p =.03) with 12% of obese patients developing AF (3.3%/year) as compared to 7% of patients with BMI < 25 kg/m2 (1.6%/year; p =.006). On multivariate analysis, age and LA transverse dimension emerged as the only variables predictive of AF. Comorbidities, including obesity, were not independently associated with AF development (p >.10 for each). SCD events occurred in 3.3% of patients (0.8%/year) and neither obesity nor other comorbidities were associated with increased risk for SCD (p >.10 for each). Conclusions: In adult HCM patients comorbidities do not appear to impact AF or SCD risk. Therefore, for most patients with HCM, adverse disease related events of AF and SCD appear to be primarily driven by underlying left ventricular and atrial myopathy as opposed to comorbidities. [ABSTRACT FROM AUTHOR]

Respiration of dissolved organic matter (DOM) in streams contributes to the global CO2 efflux, yet this efflux has not been linked to specific DOM sources and their respective uptake rates. Further, removal of DOM inferred from longitudinal concentration gradients in river networks has been insufficient to account for observed CO2 outgassing. We hypothesize that understanding in‐stream dynamics of DOM, which is a heterogeneous mixture spanning a wide range of biological labilities, requires considering that DOM lability decreases during downstream transport. To test this hypothesis, we paired seasonal bioreactor measurements of DOM biological lability with whole‐stream tracer data from White Clay Creek, Pennsylvania, USA, and used a particle‐tracking model to predict in‐stream DOM dynamics. The model simulates continuous inputs of DOM and uses storage time in the stream bioactive regions plus kinetic parameters from bioreactors to assess differential uptake of DOM fractions (i.e., fractionation) in the stream. We compared predictions for in‐stream dynamics of bulk DOM concentration (quantified as dissolved organic carbon) and fluorescent DOM components. Our model‐data synthesis approach demonstrates that more labile fractions of DOM in stream water preferentially originate and are consumed within short travel distances, causing spiraling metrics to change with downstream distance. Our model can account for local sources of rapidly cycled labile DOM, providing a basis for improved interpretation of DOM dynamics in streams that can reconcile apparent discrepancies between respiratory outgassing of CO2 and longitudinal DOM concentration gradients within river networks. Plain Language Summary: In streams, microorganisms metabolize naturally occurring organic molecules dissolved in streamwater and release carbon dioxide, which contributes to global carbon emissions. These organic molecules are part of a complex and diverse mixture including thousands of different chemical compounds that differ widely in susceptibility to biodegradation. We developed a mathematical model to describe changes in the pool of organic molecules flowing downstream, incorporating field and laboratory measurements of biological degradation of organic molecules and information about water flow into and out of zones that promote biological activity. We demonstrated that the molecules more susceptible to biodegradation are preferentially metabolized and become depleted over short travel distances downstream, while organic species less susceptible to biodegradation are transported farther downstream. Our model improves understanding of the transport and metabolism of organic molecules in streams, and explains factors that control the overall concentration of organic molecules in streams and rivers. The results help to reconcile discrepancies between estimates of carbon dioxide outgassing from streams and observations of organic carbon concentrations within streams. Key Points: Dissolved organic matter (DOM) biological lability decreases with residence time in bioactive regions of the stream (defined as bioactive residence time)Decreasing biological lability, exchange into and residence times in bioactive regions influence in‐stream DOM dynamicsModel predictions show how the distribution of DOM fractions (i.e., fractionation) and spiraling metrics depend on in‐stream location [ABSTRACT FROM AUTHOR]

Wood additions to streams can slow water velocities and provide depositional areas for bacteria and fine particles (e.g., particulate organic carbon and nutrients sorbed to fine sediment), therefore increasing solute and particle residence times. Thus, wood additions are thought to create biogeochemical hotspots in streams. Added wood is expected to enhance in‐stream heterogeneity, result in more complex flow paths, increase natural retention of fine particles and alter the geomorphic characteristics of the stream reach. Our aim was to directly measure the impact of wood additions on fine particle transport and retention processes. We conducted conservative solute and fluorescent fine particle tracer injection studies in a small agricultural stream in the Whatawhata catchment, North Island of New Zealand in two reaches—a control reach and a reach restored 1‐year earlier by means of wood additions. Fine particles were quantified in surface water to assess reach‐scale (channel thalweg) and habitat‐scale (near wood) transport and retention. Following the injection, habitat‐scale measurements were taken in biofilms on cobbles and by stirring streambed sediment to measure fine particles available for resuspension. Tracer injection results showed that fine particle retention was greater in the restored compared to the control reach, with increased habitat‐scale particle counts and reach‐scale particle retention. Particle deposition was positively correlated with cobble biofilm biomass. We also found that the addition of wood enhanced hydraulic complexity and increased the retention of solute and fine particles near the wood, especially near a channel spanning log. Furthermore, particles were more easily remobilized from the control reach. The mean particle size remobilized after stirring the sediments was ~5 μm, a similar size to both fine particulate organic matter and many microorganisms. These results demonstrate that particles in this size range are dynamic and more likely to remobilize and transport further downstream during bed mobilization events. [ABSTRACT FROM AUTHOR]

Fine particles are critical to stream ecosystem functioning, influencing in‐stream processes from pathogen transmission to carbon cycling, all of which depend on particle immobilization. However, our ability to predict particle immobilization is limited by (1) availability of combined solute and particle tracer data and (2) identifying parameters that appropriately represent fine particle immobilization, due to the myriad of objective functions and model formulations. We found that improved predictions of the full distribution of possible fine particle residence times requires using an objective function that assesses both the peak and tailing of breakthrough curves together with solute tracers to constrain in‐stream transport processes. The representation of immobilization processes was significantly improved when solute tracer data were combined with a particle model, starkly contrasting the common assumption that fine particles transport as washload. We develop a clear strategy for improving fine particle transport predictions, reshaping the potential role of fine particles in water quality management. Plain Language Summary: Fine particles, a general term that can be used to describe inorganic material like clays, particulate organic carbon, and harmful bacteria (i.e., pathogens), are important to stream functioning and water quality. The time it takes fine particles to move through a stream is difficult to predict primarily because there is no general guidance regarding the required data types and modeling approaches. Through comprehensive computational experiments and data analysis, we found that fine particles remain in streams much longer than commonly assumed, reshaping understanding of the role of fine particles in stream functioning and how waterborne pathogens are transmitted. Key Points: Applying a balanced objective function and two tracers improves accuracy of particle retention up to 57% versus applying a washload assumptionImproved parameter identifiability found with an objective function that considers both peak and tailing of breakthrough curvesParticle immobilization can be predicted directly from solute data by adding particle transport terms to a model with hyporheic exchange [ABSTRACT FROM AUTHOR]

Although most field and modeling studies of river corridor exchange have been conducted at scales ranging from tens to hundreds of meters, results of these studies are used to predict their ecological and hydrological influences at the scale of river networks. Further complicating prediction, exchanges are expected to vary with hydrologic forcing and the local geomorphic setting. While we desire predictive power, we lack a complete spatiotemporal relationship relating discharge to the variation in geologic setting and hydrologic forcing that is expected across a river basin. Indeed, the conceptual model of Wondzell (2011) predicts systematic variation in river corridor exchange as a function of (1) variation in baseflow over time at a fixed location, (2) variation in discharge with location in the river network, and (3) local geomorphic setting. To test this conceptual model we conducted more than 60 solute tracer studies including a synoptic campaign in the 5th-order river network of the H. J. Andrews Experimental Forest (Oregon, USA) and replicate-in-time experiments in four watersheds. We interpret the data using a series of metrics describing river corridor exchange and solute transport, testing for consistent direction and magnitude of relationships relating these metrics to discharge and local geomorphic setting. We confirmed systematic decrease in river corridor exchange space through the river networks, from headwaters to the larger main stem. However, we did not find systematic variation with changes in discharge through time or with local geomorphic setting. While interpretation of our results is complicated by problems with the analytical methods, the results are sufficiently robust for us to conclude that space-for-time and time-for-space substitutions are not appropriate in our study system. Finally, we suggest two strategies that will improve the interpretability of tracer test results and help the hyporheic community develop robust datasets that will enable comparisons across multiple sites and/or discharge conditions. [ABSTRACT FROM AUTHOR]

A comprehensive set of measurements and calculated metrics describing physical, chemical, and biological conditions in the river corridor is presented. These data were collected in a catchment-wide, synoptic campaign in the H. J. Andrews Experimental Forest (Cascade Mountains, Oregon, USA) in summer 2016 during low-discharge conditions. Extensive characterization of 62 sites including surface water, hyporheic water, and streambed sediment was conducted spanning 1st- through 5th-order reaches in the river network. The objective of the sample design and data acquisition was to generate a novel data set to support scaling of river corridor processes across varying flows and morphologic forms present in a river network. The data are available at 10.4211/hs.f4484e0703f743c696c2e1f209abb842 (Ward, 2019). [ABSTRACT FROM AUTHOR]

A fundamental problem in biodiversity science is determining the number of species in any taxon, and there is a growing awareness that cryptic diversity contributes to this problem – even in well-studied groups. Discovering cryptic species requires several lines of evidence to elucidate congruent patterns across data-types, and distinguish unrecognized species. Tiger beetles are among the most well-studied insect groups; yet few new North American species have been described since the mid-20th century, suggesting that that the number of morphologically distinct species is reaching an asymptote. We explore the possibility that more species exist in the fauna as cryptic species, by analysing a broad geographic sample of all species in the genus Dromochorus. We employ a 'taxonomic congruence' approach, where we first generate species hypotheses from patterns of reciprocal monophyly across the mitochondrial and nuclear datasets, and test these hypotheses through congruence with population structure, morphological measures and ecological divergence. We find broad congruence that supports eight species of Dromochorus, more than doubling the known diversity. We also validate a previously ambiguous taxon, and re-describe previously named species. Lastly, we identify new diagnostic morphological characters, include an updated dichotomous key and provide updated natural history/ecological characteristics for the genus and individual species. [ABSTRACT FROM AUTHOR]

Although most field and modeling studies of river corridor exchange have been conducted a scales ranging from 10's to 100's of meters; results of these studies are used to predict their ecological and hydrological influences at the scale of river networks. Further complicating prediction, exchange are expected to vary with hydrologic forcing and the local geomorphic setting. While we desire predictive power, we lack a complete spatiotemporal relationship relating discharge to the variation in geologic setting and hydrologic forcing that are expected across a river basin. Indeed, Wondzell's [2011] conceptual model predicts systematic variation in river corridor exchange as a function of (1) variation in discharge over time at a fixed location, (2) variation in discharge with location in the river network, and (3) local geomorphic setting. To test this conceptual model we conducted more than 60 solute tracer studies collected in a synoptic campaign in the 5th order river network of the H. J. Andrews Experimental Forest (Oregon, USA). We interpret the data using a series of metrics describing river corridor exchange and solute transport, testing for consistent direction and magnitude of relationships relating these metrics to discharge and local geomorphic setting. We confirmed systematic decrease in river corridor exchange space through the river networks, from headwaters to the larger mainstem. However, we did not find systematic variation with changes in discharge through time, nor with local geomorphic setting. While interpretation of our results are complicated by problems with the analytical methods, they are sufficiently robust for us to conclude that space-for-time and time-for-space substitutions are not appropriate in our study system. Finally, we suggest two strategies that will improve the interpretability of tracer test results and help the hyporheic community develop robust data sets that will enable comparisons across multiple sites and/or discharge conditions. [ABSTRACT FROM AUTHOR]

A comprehensive set of measurements and calculated metrics describing physical, chemical, and biological conditions in the river corridor is presented. These data were collected in a catchment-wide, synoptic campaign in Lookout Creek within the H.J. Andrews Experimental Forest (Cascade Mountains, Oregon, USA) in summer 2016 during low discharge conditions. Extensive characterization of 62 sites including surface water, hyporheic water, and streambed sediment was conducted spanning 1st through 5th order reaches in the river network. The objective of the sample design and data acquisition was to generate a novel data set to support scaling of river corridor processes across varying flows and morphologic forms present in a river network. The data are available at http://www.hydroshare.org/resource/f4484e0703f743c696c2e1f209abb842 (Ward, 2019). [ABSTRACT FROM AUTHOR]

Anomalous transport cannot be adequately described with classical Fickian advection-dispersion equations (ADE) with constant coefficients. Rather, fractional calculus models may be used, which capture salient features of anomalous transport (e.g., skewness and power law tails). FracFit is a parameter estimation tool based on space-fractional and time-fractional models used by the hydrology community. Currently, four fractional models are supported: (1) space-fractional advection-dispersion equation (sFADE), (2) time-fractional dispersion equation with drift (TFDE), (3) fractional mobile-immobile (FMIM) equation, and (4) temporally tempered Lévy motion (TTLM). Model solutions using pulse initial conditions and continuous injections are evaluated using stable distributions or subordination integrals. Parameter estimates are extracted from measured breakthrough curves (BTCs) using a weighted nonlinear least squares (WNLS) algorithm. Optimal weights for BTCs for pulse initial conditions and continuous injections are presented. Two sample applications are analyzed: (1) pulse injection BTCs in the Selke River and (2) continuous injection laboratory experiments using natural organic matter. Model parameters are compared across models and goodness-of-fit metrics are presented, facilitating model evaluation. [ABSTRACT FROM AUTHOR]

A scoping review of the literature on parenting programmes that target the promotion of adolescent mental health was conducted to examine the quality of the studies and unique content of programmes for parents from ethnoculturally diverse communities. PsycINFO and Web of Science were searched in April, 2011 (for all publications prior to that date) and again in August, 2015 (for publications from April, 2011 to August, 2015) using specific keywords and inclusion criteria. A hand search was also conducted. Overall, 107 studies met inclusion criteria for final data extraction and included evaluations of interventions targeted at substance use, early/risky sexual activity and behavioural problems. Eighteen of the 107 studies described programmes targeting parents of adolescents from diverse ethnocultural communities; the quality of these 18 studies was assessed using a marginally modified version of the Downs and Black Checklist (Downs & Black 1998). Their average quality assessment score was 16 out of 28. In addition, two key themes reflected in successful interventions emerged: strengthening parent-adolescent relationship through communication, and importance of community engagement in designing and implementing the intervention. Findings indicate gaps in service delivery to parents of adolescents from ethnoculturally diverse communities; there are a limited number of studies on programmes targeting ethnoculturally diverse parents of adolescents, and the quality of studies that do exist is overall low. Given increasing diversity, more emphasis should be placed on developing and modifying programmes to meet the needs of ethnoculturally diverse communities. More rigorous, standardised efforts should be made to evaluate programmes that do exist. [ABSTRACT FROM AUTHOR]

Shallow benthic biolayers at the top of the streambed are believed to be places of enhanced biogeochemical turnover within the hyporheic zone. They can be investigated by reactive stream tracer tests with tracer recordings in the streambed and in the stream channel. Common in-stream measurements of such reactive tracers cannot localize where the processing primarily takes place, whereas isolated vertical depth profiles of solutes within the hyporheic zone are usually not representative of the entire stream. We present results of a tracer test where we injected the conservative tracer bromide together with the reactive tracer resazurin into a third-order stream and combined the recording of in-stream breakthrough curves with multidepth sampling of the hyporheic zone at several locations. The transformation of resazurin was used as an indicator of metabolism, and high-reactivity zones were identified from depth profiles. The results from our subsurface analysis indicate that the potential for tracer transformation (i.e., the reaction rate constant) varied with depth in the hyporheic zone. This highlights the importance of the benthic biolayer, which we found to be on average 2 cm thick in this study, ranging from one third to one half of the full depth of the hyporheic zone. The reach-scale approach integrated the effects of processes along the reach length, isolating hyporheic processes relevant for whole-stream chemistry and estimating effective reaction rates. [ABSTRACT FROM AUTHOR]

Stream hydraulics control flux into and out of slow-moving water transient storage (WTS) zones and, thus, hydrologic retention in stream channels. In-stream nutrient uptake is thought to depend on hydrologic retention, so stream hydraulics could influence the extent to which in-stream nutrient biogeochemistry affects nutrient export downstream. Our goals were to: 1) characterize WTS with an emphasis on water residence time and 2) evaluate its influence on nutrient uptake. We analyzed data from 2 y of monthly solute-tracer injections with accompanying nutrient-uptake estimates in 2 hydrogeomorphically different streams. We fit the conservative tracer breakthrough curves to 2 hydrodynamic models: the one-dimensional transport with inflow and storage (OTIS) and the stochastic mobile-immobile model (SMIM), which allows for a wide distribution of water residence times. The 2 streams differed hydraulically, especially in water residence-time distributions in WTS zones. SMIM parameters depended less on discharge than did OTIS parameters, indicating that SMIM may be influenced more by local features of channel morphology than by hydrologic conditions. NH4+ uptake differed between streams, was correlated with all SMIM hydraulic parameters, and was weakly correlated with only 1 OTIS parameter. Based on SMIM correlations, the parameters related to the exchange of free-flowing water with water storage zones and the in-stream retention times explained 43 and 41%, respectively, of the variation in NH4+ uptake in the streams. Soluble reactive P (SRP) uptake was similar between streams and was not correlated with hydraulic parameters. These results indicate that hydraulics and residence time of water can be important regulators of WTS zones and nutrient uptake in headwater streams, but other environmental factors must be considered for complete understanding of in-stream nutrient processing capacity. [ABSTRACT FROM AUTHOR]

This article reports the findings of an exploratory study examining service provider perceptions and experiences of addressing sexuality and intimacy with women spousal caregivers. The caregiver--provider encounter is examined, and challenges faced by service providers in addressing sexuality are considered. Themes identified include ambivalence and discomfort, personal and institutional barriers, meanings attributed to sexuality and intimacy, and lack of opportunities to discuss experiences. Strategies to overcome silence and invisibility on the part of service providers in the health and social services system are considered. [ABSTRACT FROM AUTHOR]

Summary On the basis of multidimensional and comprehensive molecular characterization (including DNA methalylation and copy number, RNA, and protein expression), we classified 894 renal cell carcinomas (RCCs) of various histologic types into nine major genomic subtypes. Site of origin within the nephron was one major determinant in the classification, reflecting differences among clear cell, chromophobe, and papillary RCC. Widespread molecular changes associated with TFE3 gene fusion or chromatin modifier genes were present within a specific subtype and spanned multiple subtypes. Differences in patient survival and in alteration of specific pathways (including hypoxia, metabolism, MAP kinase, NRF2-ARE, Hippo, immune checkpoint, and PI3K/AKT/mTOR) could further distinguish the subtypes. Immune checkpoint markers and molecular signatures of T cell infiltrates were both highest in the subtype associated with aggressive clear cell RCC. Differences between the genomic subtypes suggest that therapeutic strategies could be tailored to each RCC disease subset. [ABSTRACT FROM AUTHOR]

To improve early enrollment in HIV care, the Swaziland Ministry of Health implemented new linkage procedures for persons HIV diagnosed during the Soka Uncobe male circumcision campaign (SOKA, 2011–2012) and the Swaziland HIV Incidence Measurement Survey (SHIMS, 2011). Abstraction of clinical records and telephone interviews of a retrospective cohort of HIV-diagnosed SOKA and SHIMS clients were conducted in 2013–2014 to evaluate compliance with new linkage procedures and enrollment in HIV care at 92 facilities throughout Swaziland. Of 1,105 clients evaluated, within 3, 12, and 24 months of diagnosis, an estimated 14.0%, 24.3%, and 37.0% enrolled in HIV care, respectively, after adjusting for lost to follow-up and non-response. Kaplan-Meier functions indicated lower enrollment probability among clients 14–24 (P = 0.0001) and 25–29 (P = 0.001) years of age compared with clients >35 years of age. At 69 facilities to which clients were referred for HIV care, compliance with new linkage procedures was low: referral forms were located for less than half (46.8%) of the clients, and few (9.6%) were recorded in the appointment register or called either before (0.3%) or after (4.9%) their appointment. Of over one thousand clients newly HIV diagnosed in Swaziland in 2011 and 2012, few received linkage services in accordance with national procedures and most had not enrolled in HIV care two years after their diagnosis. Our findings are a call to action to improve linkage services and early enrollment in HIV care in Swaziland. [ABSTRACT FROM AUTHOR]

Summary The ampulla of Vater is a complex cellular environment from which adenocarcinomas arise to form a group of histopathologically heterogenous tumors. To evaluate the molecular features of these tumors, 98 ampullary adenocarcinomas were evaluated and compared to 44 distal bile duct and 18 duodenal adenocarcinomas. Genomic analyses revealed mutations in the WNT signaling pathway among half of the patients and in all three adenocarcinomas irrespective of their origin and histological morphology. These tumors were characterized by a high frequency of inactivating mutations of ELF3, a high rate of microsatellite instability, and common focal deletions and amplifications, suggesting common attributes in the molecular pathogenesis are at play in these tumors. The high frequency of WNT pathway activating mutation, coupled with small-molecule inhibitors of β-catenin in clinical trials, suggests future treatment decisions for these patients may be guided by genomic analysis. [ABSTRACT FROM AUTHOR]

In streams and rivers, the benthic and hyporheic regions harbor the microbes that process many stream-borne constituents, including O2, nutrients, C, and contaminants. The full distribution of transport time scales in these highly reactive regions must be understood because solute delivery and extended storage in these metabolically active zones control the opportunity for biogeochemical processing. The most commonly used transport models cannot capture these effects. We present a stochastic model for conservative and reactive solute transport in rivers based on continuous-time random-walk theory, which is capable of distinguishing and capturing processes not described by classical approaches. The model includes surface and subsurface storage zones with arbitrary residence-time distributions. We used this model to evaluate the effects of sorption and biological uptake on downstream solute transport. Linear or mildly nonlinear sorption in storage delays downstream transport without changing the fundamental shape of the breakthrough curves (BTCs). Highly nonlinear sorption isotherms can induce power-law tailing in stream BTCs. Model simulations show that sorption of commonly used solute tracers is not sufficient to explain the power-law tailing that has been observed in field tracer-injection studies, and instead, such tailing most probably reflects broad distributions of hyporheic exchange time scales. First-order biological uptake causes an exponential decline in instream tracer concentrations at the time scale of the uptake kinetics, thereby tempering power-law BTCs. The model can be used to calculate reach-scale reaction-rate coefficients in surface and subsurface storage from observed BTCs of co-injected conservative and reactive solutes, providing new capability to determine reaction-rate coefficients in storage zones with broad residence-time distributions. [ABSTRACT FROM AUTHOR]

Background: Parents have a strong influence on their child's engagement in physical activities, especially for children with developmental disabilities, as these children are less likely to initiate physical activity. Knowledge is limited regarding parents' perceptions of this phenomenon in low- and middle-income countries (LMICs); yet many rehabilitation providers work with children with developmental disabilities and their parents in these contexts. Purpose: The aim of this study was to explore the barriers perceived by parents of children with developmental disabilities to their children's engagement in physical activity. Methods: An occupational perspective was used to explore how parents speak about barriers to their child's engagement in physical activity. Interviews were conducted with nine parents in Port-of-Spain, Trinidad and Tobago . Findings: Parent's perceived barriers were categorized into four themes: family priorities, not an option in our environment, need to match the activity to the child's ability, and need for specialized supports. Conclusions: Findings provide opportunities for future rehabilitation and community programming in LMICs. [ABSTRACT FROM AUTHOR]

The authors discuss the aspects of The Cancer Genome Atlas (TCGA) Research Network's Pan-Cancer scheme, which investigated a significant number of tumors to find molecular aberrations at the RNA, DNA, and protein levels. The project was introduced in Santa Cruz, California from October 26-27, 2013, and aims to gather coherent data sets of tumor types. The authors add that the TCGA Pan-Cancer papers provide an important contribution to cancer research.

To characterize somatic alterations in colorectal carcinoma, we conducted a genome-scale analysis of 276 samples, analysing exome sequence, DNA copy number, promoter methylation and messenger RNA and microRNA expression. A subset of these samples (97) underwent low-depth-of-coverage whole-genome sequencing. In total, 16% of colorectal carcinomas were found to be hypermutated: three-quarters of these had the expected high microsatellite instability, usually with hypermethylation and MLH1 silencing, and one-quarter had somatic mismatch-repair gene and polymerase ? (POLE) mutations. Excluding the hypermutated cancers, colon and rectum cancers were found to have considerably similar patterns of genomic alteration. Twenty-four genes were significantly mutated, and in addition to the expected APC, TP53, SMAD4, PIK3CA and KRAS mutations, we found frequent mutations in ARID1A, SOX9 and FAM123B. Recurrent copy-number alterations include potentially drug-targetable amplifications of ERBB2 and newly discovered amplification of IGF2. Recurrent chromosomal translocations include the fusion of NAV2 and WNT pathway member TCF7L1. Integrative analyses suggest new markers for aggressive colorectal carcinoma and an important role for MYC-directed transcriptional activation and repression. [ABSTRACT FROM AUTHOR]

We report on a secreted protein found in mammalian cochlear outer hair cells (OHC) that is a member of the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family of adhesion proteins. Ceacam16 mRNA is expressed in OHC, and its protein product localizes to the tips of the tallest stereocilia and the tectorial membrane (TM). This specific localization suggests a role in maintaining the integrity of the TM as well as in the connection between the OHC stereocilia and TM, a linkage essential for mechanical amplification. In agreement with this role, CEACAM16 colocalizes and coimmunoprecipitates with the TM protein α-tectorin. In addition, we show that mutation of CEACAM16 leads to autosomal dominant nonsyndromic deafness (ADNSHL) at the autosomal dominant hearing loss (DFNA4) locus. In aggregate, these data identify CEACAM16 as an α-tectorin-interacting protein that concentrates at the point of attachment of the TM to the stereocilia and, when mutated, results in ADNSHL at the DFNA4 locus. [ABSTRACT FROM AUTHOR]

Reports on the use of non-invasive mechanical ventilation (NIMV) for exacerbation of chronic obstructive pulmonary disease (COPD) in Canada. Effects of the medical treatment on patients suffering from an exacerbation of COPD; Potential benefits of NIMV; Development of protocols to cover initiation of the treatment.

Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by multiple scientific disciplines for almost half a century. These previous efforts have shown that the hyporheic zone is a modulator for most metabolic stream processes and serves as a refuge and habitat for a diverse range of aquatic organisms. It also exerts a major control on river water quality by increasing the contact time with reactive environments, which in turn results in retention and transformation of nutrients, trace organic compounds, fine suspended particles, and microplastics, among others. The paper showcases the critical importance of hyporheic zones, both from a scientific and an applied perspective, and their role in ecosystem services to answer the question of the manuscript title. It identifies major research gaps in our understanding of hyporheic processes. In conclusion, we highlight the potential of hyporheic restoration to efficiently manage and reactivate ecosystem functions and services in river corridors. [ABSTRACT FROM AUTHOR]

Time-variable discharge is known to control both transport and transformation of solutes in the river corridor. Still, few studies consider the interactions of transport and transformation together. Here, we consider how diurnal discharge fluctuations in an intermittent, headwater stream control reach-scale solute transport and transformation as measured with conservative and reactive tracers during a period of no precipitation. One common conceptual model is that extended contact times with hyporheic zones during low discharge conditions allows for increased transformation of reactive solutes. Instead, we found tracer timescales within the reach were related to discharge, described by a single discharge-variable StorAge Selection function. We found that Resazurin to Resorufin (Raz-to-Rru) transformation is static in time, and apparent differences in reactive tracer were due to interactions with different ages of storage, not with time-variable reactivity. Overall we found reactivity was highest in youngest storage locations, with minimal Raz-to-Rru conversion in waters older than about 20 h of storage in our study reach. Therefore, not all storage in the study reach has the same potential biogeochemical function and increasing residence time of solute storage does not necessarily increase reaction potential of that solute, contrary to prevailing expectations. [ABSTRACT FROM AUTHOR]