The aquatic networks that connect soils with oceans receive each year 5.1 Pg of terrestrial carbon to transport, bury and process. Stagnant sections of aquatic networks often become anoxic. Mineral ...surfaces attract specific components of organic carbon, which are released under anoxic conditions to the pool of dissolved organic matter (DOM). The impact of the anoxic release on DOM molecular composition and reactivity in inland waters is unknown. Here, we report concurrent release of iron and DOM in anoxic bottom waters of northern lakes, removing DOM from the protection of iron oxides and remobilizing previously buried carbon to the water column. The deprotected DOM appears to be highly reactive, terrestrially derived and molecularly distinct, generating an ambient DOM pool that relieves energetic constraints that are often assumed to limit carbon turnover in anoxic waters. The Fe-to-C stoichiometry during anoxic mobilization differs from that after oxic precipitation, suggesting that up to 21% of buried OM escapes a lake-internal release-precipitation cycle, and can instead be exported downstream. Although anoxic habitats are transient and comprise relatively small volumes of water on the landscape scale, our results show that they may play a major role in structuring the reactivity and molecular composition of DOM transiting through aquatic networks and reaching the oceans.
Very few studies have explored the associations between self-identified sexual orientation and comprehensive vaccination coverage. Most of the previous studies that reported health disparities among ...lesbian, gay and bisexual populations were not based on a nationally representative sample of U.S. adults, limiting the generalizability of the findings. Starting in 2013, the National Health Interview Survey (NHIS) included questions to ascertain the adult's self-identified sexual orientation that allowed national level vaccination estimation by sexual orientation. This study examined associations of self-reported vaccination coverage for selected vaccines among U.S. adults by their sexual orientation.
We analyzed combined data from 2013-2015 NHIS, a nationally representative probability-based health survey of the noninstitutionalized U.S. population ≥18 years. For vaccines other than influenza, weighted proportions were calculated. Influenza coverage was calculated using the Kaplan-Meier procedure. Multivariable logistic regression models were used to calculate adjusted prevalence differences for each vaccine overall and stratified by sexual orientation and to identify factors independently associated with vaccination.
Significant differences were observed by sexual orientation for self-reported receipt of human papillomavirus (HPV), hepatitis A (HepA), hepatitis B (HepB), and influenza vaccination. Bisexual females (51.6%) had higher HPV coverage than heterosexual females (40.2%). Gay males (40.3% and 53.6%, respectively) had higher HepA and HepB coverage than heterosexual males (25.4% and 32.6%, respectively). Bisexual females (33.9% and 58.5%, respectively) had higher HepA and HepB coverage than heterosexual females (23.5% and 38.4%, respectively) and higher HepB coverage than lesbian females (45.4%). Bisexual adults (34.1%) had lower influenza coverage than gay/lesbian (48.5%) and heterosexual adults (43.8%). Except for the association of having self-identified as gay/lesbian orientation with greater likelihood of HepA, HepB, and influenza vaccination, sexual orientation was not associated with higher or lower likelihood of vaccination. Health status or other behavioral characteristics studied had no consistent relationship with vaccination among all populations.
Differences were identified in vaccination coverage among the U.S. adult population by self-reported sexual orientation. This study is the first to assess associations of sexual orientation with a comprehensive list of vaccinations. Findings from this study can serve as a baseline for monitoring changes over time. All populations could benefit from improved vaccination.
A broad literature base exists for measuring medication adherence to monotherapeutic regimens, but publications are less extensive for measuring adherence to multiple medications.
To identify and ...characterize the multiple medication adherence (MMA) methods used in the literature.
A literature search was conducted using PubMed, PsycINFO, the International Pharmaceutical Abstracts, the Cumulative Index to Nursing and Allied Health Literature and the Cochrane Library databases on methods used to measure MMA published between January 1973 and May 2015. A two-step screening process was used; all abstracts were screened by pairs of researchers independently, followed by a full-text review identifying the method for calculating MMA. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to conduct this systematic review. For studies that met the eligibility criteria, general study and adherence-specific characteristics and the number and type of MMA measurement methods were summarized.
The 147 studies that were included originated from 32 countries, in 13 disease states. Of these studies, 26 used proportion of days covered, 23 used medication possession ratio, and 72 used self-reported questionnaires (e.g., the Morisky Scale) to assess MMA. About 50% of the studies included more than one method for measuring MMA, and different variations of medication possession ratio and proportion of days covered were used for measuring MMA.
There appears to be no standardized method to measure MMA. With an increasing prevalence of polypharmacy, more efforts should be directed toward constructing robust measures suitable to evaluate adherence to complex regimens. Future research to understand the validity and reliability of MMA measures and their effects on objective clinical outcomes is also needed.
Organic matter, upon dissolution into the aqueous state as dissolved organic matter (DOM), can undergo mineralization by microbes. There has been increasing effort to characterize DOM released from ...thawing permafrost because it may perpetuate a permafrost carbon feedback. Permafrost-derived DOM often has a composition that can be highly susceptible to mineralization by microbes, but most studies to date that characterize permafrost-derived DOM have been limited to select regions, and tend to focus on a single type of permafrost (sometimes unspecified) that reflects a particular deposit type. Importantly, diversity in the nature of the deposit, formation of permafrost, and thaw modification processes leads to spatial and stratigraphic variability in its properties, but our understanding of variation in the composition of DOM derived from differing permafrost types (end-members) is poor. Here, we used ultrahigh-resolution mass spectrometry to characterize DOM composition derived from a series of permafrost end-member types that are commonly found within the thaw-vulnerable western Canadian Arctic, including: tills (glacially deposited), diamicton (thawed and remobilized material of mixed origin), lacustrine (lake basin sediments into which permafrost has aggraded), peat (partially decomposed organic material), and Yedoma (syngenetic silty loess) deposits. We identified marked variation in DOM composition among permafrost end-member types. Tills were compositionally dissimilar to all other permafrost end-members. Compounds unique to Yedoma were predominantly aliphatic, while compounds unique to peat, lacustrine, and diamicton spanned saturation and oxygenation gradients. All permafrost leachates were generally higher in aliphatics, lower in aromatics, and less oxygenated than active layer leachates. Compositional differences appear to reflect variation in permafrost parent materials, and particularly strong effects from past modification processes while in the unfrozen or thawed state. Constraining DOM composition and assessing its stratigraphic variability will become more pressing as the spatial and stratigraphic extent of thaw increases with future warming.
Abstract Background Positive associations between medication adherence and beneficial outcomes primarily come from studying filling/consumption behaviors after therapy initiation. Few studies have ...focused on what happens before initiation, the point from prescribing to dispensing of an initial prescription. Objective Our objective was to provide guidance and encourage high-quality research on the relationship between beneficial outcomes and initial medication adherence (IMA), the rate initially prescribed medication is dispensed. Methods Using generic adherence terms, an international research panel identified IMA publications from 1966 to 2014. Their data sources were classified as to whether the primary source reflected the perspective of a prescriber, patient, or pharmacist or a combined perspective. Terminology and methodological differences were documented among core (essential elements of presented and unpresented prescribing events and claimed and unclaimed dispensing events regardless of setting), supplemental (refined for accuracy), and contextual (setting-specific) design parameters. Recommendations were made to encourage and guide future research. Results The 45 IMA studies identified used multiple terms for IMA and operationalized measurements differently. Primary data sources reflecting a prescriber’s and pharmacist’s perspective potentially misclassified core parameters more often with shorter/nonexistent pre- and postperiods (1–14 days) than did a combined perspective. Only a few studies addressed supplemental issues, and minimal contextual information was provided. Conclusions General recommendations are to use IMA as the standard nomenclature, rigorously identify all data sources, and delineate all design parameters. Specific methodological recommendations include providing convincing evidence that initial prescribing and dispensing events are identified, supplemental parameters incorporating perspective and substitution biases are addressed, and contextual parameters are included.
Mechanical orthoses, such as the hip knee ankle foot orthosis (HKAFO) and the isocentric reciprocating gait orthosis (IRGO), are both used for walking in spinal cord injury (SCI) patients. The aim of ...this study was to analyze the energy expenditure during walking with these orthoses compared with a powered gait orthosis (PGO) in patients with SCI.
Five patients with SCI who were experienced users of HKAFOs participated in this study. Subjects were also fitted with an IRGO and PGO and underwent a specific gait training program. Patients walked along a flat walkway using the three types of orthosis at their self-selected walking speed. A stop watch and a polar heart rate monitor were used to measure the speed of walking and heart rate.
Walking speed, the distance walked and the physiological cost index (PCI) all improved with both the new PGO and the IRGO as compared with the HKAFO.
A PGO can improve walking speed and the distance walked and reduce the PCI of walking as compared with mechanical orthoses, probably due to the activated movements of the lower limb joints.
One of the ten greatest public health achievements is childhood vaccination because of its impact on controlling and eliminating vaccine-preventable diseases (VPDs). Evidence-based immunization ...policies and practices are responsible for this success and are supported by epidemiology that has generated scientific evidence for informing policy and practice. The purpose of this report is to highlight the role of epidemiology in the development of immunization policy and successful intervention in public health practice that has resulted in a measurable public health impact: the control and elimination of VPDs in the United States. Examples in which epidemiology informed immunization policy were collected from a literature review and consultation with experts who have been working in this field for the past 30 years. Epidemiologic examples (e.g., thimerosal-containing vaccines and the alleged association between the measles, mumps, and rubella (MMR) vaccine and autism) are presented to describe challenges that epidemiologists have addressed.
Finally, we describe ongoing challenges to the nation’s ability to sustain high vaccination coverage, particularly with concerns about vaccine safety and effectiveness, increasing use of religious and philosophical belief exemptions to vaccination, and vaccine hesitancy. Learning from past and current experiences may help epidemiologists anticipate and address current and future challenges to respond to emerging infectious diseases, such as COVID-19, with new vaccines and enhance the public health impact of immunization programs for years to come.
Soils export large amounts of organic matter to rivers, and there are still major uncertainties concerning the composition and reactivity of this material and its fate within the fluvial network. ...Here we reconstructed the pattern of movement and processing of dissolved organic matter (DOM) along a soil‐stream‐river continuum under summer baseflow conditions in a boreal region of Québec (Canada), using a combination of fluorescence spectra, size exclusion chromatography and ultrahigh resolution mass spectrometry. Our results show that there is a clear sequence of selective DOM degradation along the soil‐stream‐river continuum, which results in pronounced compositional shifts downstream. The soil‐stream interface was a hot spot of DOM degradation, where biopolymers and low molecular weight (LMW) compounds were selectively removed. In contrast, processing in the stream channel was dominated by the degradation of humic‐like aromatic DOM, likely driven by photolysis, with little further degradation of either biopolymers or LMW compounds. Overall, there was a high degree of coherence between the patterns observed in DOM chemical composition, optical properties, and molecular profiles, and none of these approaches pointed to measurable production of new DOM components, suggesting that the DOM pools removed during transit were likely mineralized to CO2. Our first order estimates suggest that rates of soil‐derived DOM mineralization could potentially sustain over half of the measured CO2 emissions from this stream network, with mineralization of biopolymers and humic substances contributing roughly equally to these fluvial emissions.
Plain Language Summary
Our study focused on the types of organic matter from soils that end up in streams and rivers and what happens to them once they are there. Streams and rivers emit carbon dioxide to the atmosphere. Organic matter in soils plays a role in this, but we do not fully understand how soil organic matter becomes carbon dioxide. To explore this, we collected water from rivers, streams, and soils in the Canadian subarctic in Québec and analyzed the organic matter dissolved in the water. Since organic matter is a very complex mixture of different compounds, we combined several advanced analyses to describe it and how it changed from the soils to the streams. We found large changes in organic matter between the soils and the streams, and the properties of the organic matter that disappeared were consistent with what we would expect to be broken down by microorganisms. The organic matter that made it to streams and flowed downstream was further changed, and the missing organic matter here had likely broken down by light. The organic matter broken down to carbon dioxide between soils and streams and that which broke down within streams contributed roughly equal amounts of carbon dioxide to the atmosphere.
Key Points
Succession of selective DOM degradation occurred along the soil‐stream‐river continuum with compositional shifts downstream
High degree of coherence was observed in patterns of DOM chemical composition, optical properties, and molecular profiles
Rates of soil‐derived DOM mineralization could potentially sustain over half of the measured CO2 emissions in the stream network
Streams are typically supersaturated in carbon dioxide (CO2) and methane (CH4), and are recognized as important components of regional carbon (C) emissions in northern landscapes. Whereas there is ...consensus that in most of the systems the CO2 emitted by streams represents C fixed in the terrestrial ecosystem, the pathways delivering this C to streams are still not well understood. We assessed the contribution of direct soil CO2 injection versus the oxidation of soil-derived dissolved organic C (DOC) and CH4 in supporting CO2 supersaturation in boreal streams in Québec. We measured the concentrations of CO2, CH4 and DOC in 43 streams and adjacent soil waters during summer base-flow period. A mass balance approach revealed that all three pathways are significant, and that the mineralization of soil-derived DOC and CH4 accounted for most of the estimated stream CO2 emissions (average 75% and 10%, respectively), and that these estimated contributions did not change significantly between the studied low order (≤3) streams. Whereas some of these transformations take place in the channel proper, our results suggest that they mainly occur in the hyporheic zones of the streams. Our results further show that stream CH4 emissions can be fully explained by soil CH4 inputs. This study confirms that these boreal streams, and in particular their hyporheic zones, are extremely active processors of soil derived DOC and CH4, not just vents for soil produced CO2.
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•We assessed the origin of CO2 and CH4 supersaturation in boreal streams•The C mass balance integrated lateral inputs, transformations, and stream fluxes of CO2, CH4 and DOC•Direct soil-derived CO2 injections alone cannot explain the stream CO2 fluxes•Soil-derived DOC mineralization was the major source of stream CO2 supersaturation•Soil-derived CH4 contributes significantly to both CH4 and CO2 fluxes in streams
Abstract Background There is no consensus on the precise rocker shoe outsole design that will optimally reduce plantar pressure in people with diabetes. This study aimed to understand how peak ...plantar pressure is influenced by systematically varying three design features which characterise a curved rocker shoe: apex angle, apex position and rocker angle. Methods A total of 12 different rocker shoe designs, spanning a range of each of the three design features, were tested in 24 people with diabetes and 24 healthy participants. Each subject also wore a flexible control shoe. Peak plantar pressure, in four anatomical regions, was recorded for each of the 13 shoes during walking at a controlled speed. Findings There were a number of significant main effects for each of the three design features, however, the precise effect of each feature varied between the different regions. The results demonstrated maximum pressure reduction in the 2nd–4th metatarsal regions (39%) but that lower rocker angles (< 20°) and anterior apex positions (> 60% shoe length) should be avoided for this region. The effect of apex angle was most pronounced in the 1st metatarsophalangeal region with a clear decrease in pressure as the apex angle was increased to 100°. Interpretation We suggest that an outsole design with a 95° apex angle, apex position at 60% of shoe length and 20° rocker angle may achieve an optimal balance for offloading different regions of the forefoot. However, future studies incorporating additional design feature combinations, on high risk patients, are required to make definitive recommendations.
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