Assessing the impact of contraceptive use on mental health among women of reproductive age - a systematic review.

BACKGROUND: Contraceptive use is the principal method by which women avoid unintended pregnancy. An unintended pregnancy can induce long-term distress related to the medical, emotional, and social consequences of carrying that pregnancy to term. OBJECTIVES: This review investigates the effects of modern contraception techniques such as birth control pills, long-acting reversible contraceptives (e.g., intrauterine devices, implants), and condoms on mental health status. METHODS: We searched multiple databases from inception until February 2022, with no geographical boundaries. RCTs underwent a quality assessment using the GRADE approach while the quality of observational studies was assessed using the Downs and Black scoring system. Data were analyzed through meta-analysis and relative risk and mean difference were calculated and forest plots were created for each outcome when two or more data points were eligible for analysis. MAIN RESULTS: The total number of included studies was 43. In women without previous mental disorders, both RCTs (3 studies, SMD 0.18, 95% CI [0.02, 0.34], high quality of evidence) and cohort studies (RR 1.04 95% CI [1.03, 1.04]) detected a slight increase in the risk of depression development. In women with previous mental disorders, both RCTs (9 studies, SMD - 0.15, 95% CI [-0.30, -0.00], high quality of evidence) and cohort studies (SMD - 0.26, 95% CI [-0.37, -0.15]) detected slight protective effects of depression development. It was also noticed that HC demonstrated protective effects for anxiety in both groups (SMD - 0.20, 95% CI [-0.40, -0.01]). CONCLUSIONS: Among women with pre-existing mental disorders who use hormonal contraceptives, we reported protective association with decreased depressive symptoms. However, the study also draws attention to some potential negative effects, including an increase in the risk of depression and antidepressant use among contraceptive users, a risk that is higher among women who use the hormonal IUD, implant, or patch/ring methods. Providers should select contraceptive methods taking individual aspects into account to maximize benefits and minimize risks.

The US COVID-19 Trends and Impact Survey: Continuous real-time measurement of COVID-19 symptoms, risks, protective behaviors, testing, and vaccination.

The US COVID-19 Trends and Impact Survey (CTIS) is a large, cross-sectional, internet-based survey that has operated continuously since April 6, 2020. By inviting a random sample of Facebook active users each day, CTIS collects information about COVID-19 symptoms, risks, mitigating behaviors, mental health, testing, vaccination, and other key priorities. The large scale of the survey-over 20 million responses in its first year of operation-allows tracking of trends over short timescales and allows comparisons at fine demographic and geographic detail. The survey has been repeatedly revised to respond to emerging public health priorities. In this paper, we describe the survey methods and content and give examples of CTIS results that illuminate key patterns and trends and help answer high-priority policy questions relevant to the COVID-19 epidemic and response. These results demonstrate how large online surveys can provide continuous, real-time indicators of important outcomes that are not subject to public health reporting delays and backlogs. The CTIS offers high value as a supplement to official reporting data by supplying essential information about behaviors, attitudes toward policy and preventive measures, economic impacts, and other topics not reported in public health surveillance systems.

Global monitoring of the impact of the COVID-19 pandemic through online surveys sampled from the Facebook user base.

Simultaneously tracking the global impact of COVID-19 is challenging because of regional variation in resources and reporting. Leveraging self-reported survey outcomes via an existing international social media network has the potential to provide standardized data streams to support monitoring and decision-making worldwide, in real time, and with limited local resources. The University of Maryland Global COVID-19 Trends and Impact Survey (UMD-CTIS), in partnership with Facebook, has invited daily cross-sectional samples from the social media platform's active users to participate in the survey since its launch on April 23, 2020. We analyzed UMD-CTIS survey data through December 20, 2020, from 31,142,582 responses representing 114 countries/territories weighted for nonresponse and adjusted to basic demographics. We show consistent respondent demographics over time for many countries/territories. Machine Learning models trained on national and pooled global data verified known symptom indicators. COVID-like illness (CLI) signals were correlated with government benchmark data. Importantly, the best benchmarked UMD-CTIS signal uses a single survey item whereby respondents report on CLI in their local community. In regions with strained health infrastructure but active social media users, we show it is possible to define COVID-19 impact trajectories using a remote platform independent of local government resources. This syndromic surveillance public health tool is the largest global health survey to date and, with brief participant engagement, can provide meaningful, timely insights into the global COVID-19 pandemic at a local scale.

Association of Age and Overall Survival in Surgically Resected Colorectal Cancer Patients.

INTRODUCTION: Incidence of colorectal cancer (CRC) among young patients has increased in the last 20 y often with more aggressive tumor biology. It is unclear if age < 50 y is an independent factor for shorter overall survival in CRC patients. Our objective was to determine if younger age at diagnosis was associated with worse overall survival. METHODS: This study used the National Cancer Data Base (2004-2016), retrospectively reviewing patients who underwent surgical resection for CRC. Patients were limited to only those without comorbidities and primary outcome was overall survival for all patients. RESULTS: Older patients have worse overall survival as compared to younger patients at a lower stage of disease (I and II) after adjusting for tumor location, gender, histology, stage, and systemic chemotherapy (< 36 y old versus 36-55 y old hazard ratio [HR] 1.16, confidence interval [CI] 1.03-1.29). This survival benefit is eliminated at a higher stage of disease, stage III in 36-55 y old versus < 36 y old (HR 0.96 [CI 0.90-1.03.99]) and stage IV (HR 0.94 [CI 0.89-0.99]). CONCLUSIONS: Older patients (aged > 36 y) have worse overall survival at a lower stage of disease, but the survival among all age groups was similar for stage III or IV disease in CRC.

Grading pharmacists' risk of complaints to a regulator: A retrospective cohort study.

Background: Tools to grade risk of complaint to a regulatory board have been developed for physicians but not for other health practitioner groups, including pharmacists. We aimed to develop a score that classified pharmacists into low, medium and high risk categories. Methods: Registration and complaint data were sourced from Ontario College of Pharmacists for January 2009 to December 2019. We undertook recurrent event survival analysis to predict lodgement of a complaint. We identified those variables that were associated with a complaint and included these in a risk score which we called PRONE-Pharm (Predicted Risk of New Event for Pharmacists). We assessed diagnostic accuracy and used this to identify thresholds that defined low, medium and high risk. Results: We identified 3,675 complaints against 17,308 pharmacists. Being male (HR = 1.72), older age (HR range 1.43-1.54), trained internationally (HR = 1.62), ≥1 prior complaint (HR range 2.83-9.60), and complaints about mental health or substance use (HR = 1.91), compliance with conditions (HR = 1.86), fees and servicing (HR = 1.74), interpersonal behaviour or honesty (HR = 1.40), procedures (HR = 1.75) and treatment or communication or other clinical issues (HR = 1.22) were all associated with lodgement of a complaint. When converted into the PRONE-Pharm risk score, pharmacists were assigned between 0 and 98 points with higher scores closely associated with higher probability of a complaint. A score of ≥25 had sufficient accuracy for classifying medium-risk pharmacists (specificity = 87.0%) and ≥45 for high-risk pharmacists (specificity = 98.4%). Conclusion: Distinguishing isolated incidents from persistent problems poses a significant challenge for entities responsible for the regulation of pharmacists and other health practitioners. The diagnostic properties of PRONE-Pharm (minimizing the false positives) means that the risk score is useful for "ruling-out" low risk pharmacists using routinely collected regulatory data. PRONE-Pharm may be useful when used alongside interventions appropriately matched to a pharmacist's level of risk.

The potential role of biofilms in promoting fouling formation in radioactive discharge pipelines.

Nuclear facility discharge pipelines accumulate inorganic and microbial fouling and radioactive contamination, however, research investigating the mechanisms that lead to their accumulation is limited. Using the Sellafield discharge pipeline as a model system, this study utilised modified Robbins devices to investigate the potential interplay between inorganic and biological processes in supporting fouling formation and radionuclide uptake. Initial experiments showed polyelectrolytes (present in pipeline effluents), had minimal effects on fouling formation. Biofilms were, however, found to be the key component promoting fouling, leading to increased uptake of inorganic particulates and metal contaminants (Cs, Sr, Co, Eu and Ru) compared to a non-biofilm control system. Biologically-mediated uptake mechanisms were implicated in Co and Ru accumulation, with a potential bioreduced Ru species identified on the biofilm system. This research emphasised the key role of biofilms in promoting fouling in discharge pipelines, advocating for the use of biocide treatments methods.

The mTOR regulated RNA-binding protein LARP1 requires PABPC1 for guided mRNA interaction.

The mammalian target of rapamycin (mTOR) is a critical regulator of cell growth, integrating multiple signalling cues and pathways. Key among the downstream activities of mTOR is the control of the protein synthesis machinery. This is achieved, in part, via the co-ordinated regulation of mRNAs that contain a terminal oligopyrimidine tract (TOP) at their 5'ends, although the mechanisms by which this occurs downstream of mTOR signalling are still unclear. We used RNA-binding protein (RBP) capture to identify changes in the protein-RNA interaction landscape following mTOR inhibition. Upon mTOR inhibition, the binding of LARP1 to a number of mRNAs, including TOP-containing mRNAs, increased. Importantly, non-TOP-containing mRNAs bound by LARP1 are in a translationally-repressed state, even under control conditions. The mRNA interactome of the LARP1-associated protein PABPC1 was found to have a high degree of overlap with that of LARP1 and our data show that PABPC1 is required for the association of LARP1 with its specific mRNA targets. Finally, we demonstrate that mRNAs, including those encoding proteins critical for cell growth and survival, are translationally repressed when bound by both LARP1 and PABPC1.

Caregiver feeding decisions and sociodemographic characteristics are associated with snack food intake during infancy and toddlerhood.

Snacking starts early in childhood, yet little is known about child versus family influences on snacking during infancy and toddlerhood. This secondary analysis of baseline data examined associations of child characteristics (e.g., appetitive traits, temperament), caregiver feeding decisions, and sociodemographic characteristics with the mean frequency of (times/day) and mean energy from (kcal/day) child snack food intake. Caregivers and their children (ages 9-15 months) were recruited in Buffalo, NY from 2017 to 2019. Caregivers reported on sociodemographics, child appetitive traits (Baby Eating Behaviour Questionnaire), and child temperament (Infant Behavior Questionnaire-Revised). Three 24-h dietary recalls were collected, and USDA food categories were used to categorize snack foods (e.g., cookies, chips, and puffs). Hierarchical multiple linear regression models examined associations of child characteristics (Step 1: age, sex, baseline weight-for-length z-score, appetitive traits, and temperament), caregiver feeding decisions (Step 2: breastfeeding duration and age of solid food introduction), and caregiver sociodemographic characteristics (Step 3: caregiver age, prepregnancy BMI, education, and household size) with mean child snack food intake. Caregivers (n = 141) were on average 32.6 years of age, predominantly white (89.1%), and college-educated (84.2%). Age of solid food introduction (B = -0.21, p = 0.03), prepregnancy BMI (B = 0.03, p = 0.04), and household size (B = 0.23, p = 0.02) were significantly associated with the mean frequency of (times/day) snack food intake, over and above other variables of interest. Child age (B = 15.96, p = 0.002) was significantly associated with mean energy from (kcal/day) snack food intake. Household size (B = 28.51, p = 0.006) was significantly associated with mean energy from (kcal/day) snack food intake, over and above other variables of interest. There were no significant associations of other child characteristics with snack food intake. Findings show that child snack food intake is more closely associated with caregiver feeding decisions and sociodemographic characteristics than child characteristics. TRIAL REGISTRATION: National Institute on Child Health and Human Development, Grant/Award Number R01HD087082-01.

miR-18a and miR-106a Signatures in Plasma Small EVs Are Promising Biomarkers for Early Detection of Pancreatic Ductal Adenocarcinoma.

Pancreatic cancer is the third leading cause of cancer-related death in the United States. Pancreatic ductal adenocarcinoma (PDAC) is the major form of pancreatic cancer with the worst outcomes. Early detection is key to improving the overall survival rate of PDAC patients. Recent studies have demonstrated that microRNA (miRNA) signatures in plasma small extracellular vesicles (EVs) are potential biomarkers for the early detection of PDAC. However, published results are inconsistent due to the heterogeneity of plasma small EVs and the methods used for small EV isolation. We have recently refined the process of plasma small EV isolation using double filtration and ultracentrifugation. In the present study, we applied this protocol and analyzed plasma small EV miRNA signatures by small RNA sequencing and quantitative RT-PCR in a pilot cohort, consisting of patients with early-stage PDAC, and age- and gender-matched healthy subjects (n = 20). We found, via small RNA sequencing, that there are several miRNAs enriched in plasma small EVs of PDAC patients, and the levels of miR-18a and miR-106a were confirmed by quantitative RT-PCR to be significantly elevated in patients with early-stage PDAC compared with age- and gender-matched healthy subjects. Furthermore, using an immunoaffinity-based plasma small EV isolation approach, we confirmed that the levels of miR-18a and miR-106a in plasma small EVs were significantly higher in PDAC patients versus the healthy subjects. We thus conclude that the levels of miR-18a and miR-106a in plasma small EVs are promising biomarkers for the early detection of PDAC.

Sorption of Strontium to Uraninite and Uranium(IV)-Silicate Nanoparticles.

Spent nuclear fuel contains both uranium (U) and high yield fission products, including strontium-90 (90Sr), a key radioactive contaminant at nuclear facilities. Both U and 90Sr will be present where spent nuclear fuel has been processed, including in storage ponds and tanks. However, the interactions between Sr and U phases under ambient conditions are not well understood. Over a pH range of 4-14, we investigate Sr sorption behavior in contact with two nuclear fuel cycle relevant U(IV) phases: nano-uraninite (UO2) and U(IV)-silicate nanoparticles. Nano-UO2 is a product of the anaerobic corrosion of metallic uranium fuel, and UO2 is also the predominant form of U in ceramic fuels. U(IV)-silicates form stable colloids under the neutral to alkaline pH conditions highly relevant to nuclear fuel storage ponds and geodisposal scenarios. In sorption experiments, Sr had the highest affinity for UO2, although significant Sr sorption also occurred to U(IV)-silicate phases at pH ≥ 6. Extended X-ray absorption fine structure (EXAFS) spectroscopy, transmission electron microscopy, and desorption data for the UO2 system suggested that Sr interacted with UO2 via a near surface, highly coordinated complex at pH ≥ 10. EXAFS measurements for the U(IV)-silicate samples showed outer-sphere Sr sorption dominated at acidic and near-neutral pH with intrinsic Sr-silicates forming at pH ≥ 12. These complex interactions of Sr with important U(IV) phases highlight a largely unrecognized control on 90Sr mobility in environments of relevance to spent nuclear fuel management and storage.

Hydrotalcite Colloidal Stability and Interactions with Uranium(VI) at Neutral to Alkaline pH.

In the United Kingdom, decommissioning of legacy spent fuel storage facilities involves the retrieval of radioactive sludges that have formed as a result of corrosion of Magnox nuclear fuel. Retrieval of sludges may re-suspend a colloidal fraction of the sludge, thereby potentially enhancing the mobility of radionuclides including uranium. The colloidal properties of the layered double hydroxide (LDH) phase hydrotalcite, a key product of Magnox fuel corrosion, and its interactions with U(VI) are of interest. This is because colloidal hydrotalcite is a potential transport vector for U(VI) under the neutral-to-alkaline conditions characteristic of the legacy storage facilities and other nuclear decommissioning scenarios. Here, a multi-technique approach was used to investigate the colloidal stability of hydrotalcite and the U(VI) sorption mechanism(s) across pH 7-11.5 and with variable U(VI) surface loadings (0.01-1 wt %). Overall, hydrotalcite was found to form stable colloidal suspensions between pH 7 and 11.5, with some evidence for Mg2+ leaching from hydrotalcite colloids at pH ≤ 9. For systems with U present, >98% of U(VI) was removed from the solution in the presence of hydrotalcite, regardless of pH and U loading, although the sorption mode was affected by both pH and U concentrations. Under alkaline conditions, U(VI) surface precipitates formed on the colloidal hydrotalcite nanoparticle surface. Under more circumneutral conditions, Mg2+ leaching from hydrotalcite and more facile exchange of interlayer carbonate with the surrounding solution led to the formation of uranyl carbonate species (e.g., Mg(UO2(CO3)3)2-(aq)). Both X-ray absorption spectroscopy (XAS) and luminescence analysis confirmed that these negatively charged species sorbed as both outer- and inner-sphere tertiary complexes on the hydrotalcite surface. These results demonstrate that hydrotalcite can form pseudo-colloids with U(VI) under a wide range of pH conditions and have clear implications for understanding the uranium behavior in environments where hydrotalcite and other LDHs may be present.

Development of a Risk Score to Predict Post-Discharge Rehabilitation Care After Liver Metastasectomy.

INTRODUCTION: Need for discharge to intermediate care (DCIC) can increase length of stay and be a source of stress to patients. Estimating risk of DCIC would allow earlier involvement of case managers, improve length of stay and patient satisfaction by setting realistic expectations. The aim was to use National Surgical Quality Improvement Program dataset to develop a prediction model for DCIC after undergoing liver metastasectomy. METHODS: Data were obtained from National Surgical Quality Improvement Program 2011-2018 covering liver metastasectomy. Recursive partitioning narrowed potential predictors and identified thresholds for categorization of continuous variables. Logistic regression identified a predictive model, internally validated by using 200 bootstrap samples with replacement. A risk score was derived using Framingham Study methodology by dividing all regression coefficients by the smallest model coefficient. Receiver operating characteristic analysis identified the score that maximized sensitivity/specificity, defining low/high risk. Finally, recursive partitioning identified categories low/medium/high. RESULTS: The most parsimonious model predicting DCIC area under the curve (, 0.722, 95%CI: 0.705-0.739) identified five independent predictors including age >60, procedure type, hypertension requiring medication, albumin <3.5 mg/dL and hematocrit <30%. Internal validation resulted in expected bias-corrected area under the curve of 0.717, 95% CI: 0.698-0.732. The maximum score was 17.9 and 5.8 maximized sensitivity (sn) and specificity (sp) [sn = 81%, sp = 51%) predicting DCIC. Stratified into three groups, a score ≥9.5 identified highest risk (12.8%), ≥4.3 medium (6.1%) and <4.3 lowest risk (1.5%). CONCLUSIONS: Determining risk of DCIC benefits shared decision making and patient care. This evidence may enhance discharge planning after liver metastasectomy expediting the process. Age >60 contributed the most weight to the score, but the use of additional variables in three groups allowed further discrimination between patients.

Sulfidation and Reoxidation of U(VI)-Incorporated Goethite: Implications for U Retention during Sub-Surface Redox Cycling.

Over 60 years of nuclear activity have resulted in a global legacy of contaminated land and radioactive waste. Uranium (U) is a significant component of this legacy and is present in radioactive wastes and at many contaminated sites. U-incorporated iron (oxyhydr)oxides may provide a long-term barrier to U migration in the environment. However, reductive dissolution of iron (oxyhydr)oxides can occur on reaction with aqueous sulfide (sulfidation), a common environmental species, due to the microbial reduction of sulfate. In this work, U(VI)-goethite was initially reacted with aqueous sulfide, followed by a reoxidation reaction, to further understand the long-term fate of U species under fluctuating environmental conditions. Over the first day of sulfidation, a transient release of aqueous U was observed, likely due to intermediate uranyl(VI)-persulfide species. Despite this, overall U was retained in the solid phase, with the formation of nanocrystalline U(IV)O2 in the sulfidized system along with a persistent U(V) component. On reoxidation, U was associated with an iron (oxyhydr)oxide phase either as an adsorbed uranyl (approximately 65%) or an incorporated U (35%) species. These findings support the overarching concept of iron (oxyhydr)oxides acting as a barrier to U migration in the environment, even under fluctuating redox conditions.

Mindfulness and Sexual Dysfunction: A Systematic Research Synthesis.

Throughout the previous decade, research exploring the associations between mindfulness and sexual dysfunction has grown exponentially. Researchers have highlighted inverse associations between mindfulness and various sexual dysfunctions, including erectile dysfunction, hypersexuality, and sexual distress, as well as positive associations between mindfulness and sexual desire, sexual satisfaction, and overall sexual functioning. This study sought to describe the state of extant literature exploring the association between mindfulness and sexual dysfunction, identify areas for future study within this area of research, and inform clinical practice when working with those experiencing sexual dysfunction. A systematic search of peer-reviewed journal articles revealed a final sample of 18 articles. After collecting data from all included articles, results support the inverse association between mindfulness and various sexual dysfunctions. Additionally, results highlight that current mindfulness and sexual dysfunction literature focuses more on the individual's experience and does not fully consider how the couple system is often impacted by, and may contribute to, the maintenance of sexual dysfunction. Furthermore, results demonstrate the importance of including LGBTQ + populations in future research, as extant literature in this area has focused primarily on the heterosexual experience.

Added sugars mediate the relation between pre-pregnancy BMI and infant rapid weight gain: a preliminary study.

BACKGROUND: Parental obesity is linked to offspring obesity, though little research has explored factors that might influence this relationship during the complementary feeding period. This study investigated whether infant intakes of added sugars mediate the relationship between a mother's pre-pregnancy body mass index (BMI) and infant rapid weight gain (defined as upward weight-for-age percentile crossing). METHODS: This study was of a cross-sectional design. Anthropometrics for 141 mother-infant dyads (mean age [standard deviation]: 32.6 [4.4] year for mothers, 11.9 [1.9] months for infants) were obtained. Data from three 24-h recalls pertaining to the infants' diets were collected and analyzed. Pearson product-moment correlations and multivariable regressions assessed bivariate relationships between pre-pregnancy BMI, infant added sugar intakes and upward weight-for-age percentile crossing. Mediation models evaluated the effects of added sugars and breastfeeding duration. RESULTS: Pre-pregnancy BMI correlated positively with infants' added sugar intakes (r = 0.230, p = 0.006). Added sugar intakes mediated the impact of pre-pregnancy BMI on upward weight-for-age percentile crossing (indirect effect = 0.007, 95% CI = 0.0001, 0.0197, indirect/total effect ratio = 0.280). Breastfeeding duration also moderated the relationship, with infants who were breastfed for a shorter duration experiencing a greater mediating effect (indirect effect = 0.010, 95% CI = 0.0014, 0.0277, indirect/direct effect ratio = 0.7368). CONCLUSIONS: Mothers who were overweight or obese prior to pregnancy were significantly more likely to give their infants foods and beverages with added sugars, and this practice was found to mediate the relationship between maternal and infant obesity. Breastfeeding duration moderated the mediating effect of added sugars between pre-pregnancy BMI and infant rapid weight gain.

Association Between Added Sugars from Infant Formulas and Rapid Weight Gain in US Infants and Toddlers.

BACKGROUND: Formulas often contain high amounts of added sugars, though little research has studied their connection to obesity. OBJECTIVES: This study assessed the contribution of added sugars from formulas during complementary feeding on total added sugar intakes, and the association between these sugars and upward weight-for-age percentile (WFA%) crossing (i.e., participants crossing a higher threshold percentile were considered to have an upward crossing). METHODS: Data from three 24-hour dietary recalls for infants (n = 97; 9-12 months) and toddlers (n = 44; 13-15 months) were obtained in this cross-sectional analysis. Foods and beverages with added sugars were divided into 17 categories. Pearson's correlations were used to test relations between added sugar intake and upward WFA% crossing, followed by multivariable regressions when significant. ANOVA compared intakes of all, milk-based, and table foods between primarily formula-fed compared with breastfed participants. Multivariable regressions were used to test effects of added sugars and protein from all foods compared with added sugars and protein from milk-based sources on upward WFA% crossing. RESULTS: Added sugars from formulas comprised 66% and 7% of added sugars consumed daily by infants and toddlers, respectively. A significant association was observed between upward WFA% crossing and added sugars from milk-based sources after controlling for gestational age, sex, age, introduction to solid foods, mean energy intakes, and maternal pre-pregnancy BMI and education (ß = 0.003; 95% CI, 0.000-0.007; P = 0.046). Primarily formula-fed participants consumed nearly twice the energy from added sugars (P = 0.003) and gained weight faster (upward WFA% crossing = 1.1 ± 1.2 compared with 0.3 ± 0.6, respectively; P < 0.001) than their breastfed counterparts. CONCLUSIONS: Added sugars in formulas predict rapid weight gain in infants and toddlers. Educating mothers on lower-sugar options may enhance childhood obesity prevention.

Biomineralization of Uranium-Phosphates Fueled by Microbial Degradation of Isosaccharinic Acid (ISA).

Geological disposal is the globally preferred long-term solution for higher activity radioactive wastes (HAW) including intermediate level waste (ILW). In a cementitious disposal system, cellulosic waste items present in ILW may undergo alkaline hydrolysis, producing significant quantities of isosaccharinic acid (ISA), a chelating agent for radionuclides. Although microbial degradation of ISA has been demonstrated, its impact upon the fate of radionuclides in a geological disposal facility (GDF) is a topic of ongoing research. This study investigates the fate of U(VI) in pH-neutral, anoxic, microbial enrichment cultures, approaching conditions similar to the far field of a GDF, containing ISA as the sole carbon source, and elevated phosphate concentrations, incubated both (i) under fermentation and (ii) Fe(III)-reducing conditions. In the ISA-fermentation experiment, U(VI) was precipitated as insoluble U(VI)-phosphates, whereas under Fe(III)-reducing conditions, the majority of the uranium was precipitated as reduced U(IV)-phosphates, presumably formed via enzymatic reduction mediated by metal-reducing bacteria, including Geobacter species. Overall, this suggests the establishment of a microbially mediated "bio-barrier" extending into the far field geosphere surrounding a GDF is possible and this biobarrier has the potential to evolve in response to GDF evolution and can have a controlling impact on the fate of radionuclides.

Fe(II) Induced Reduction of Incorporated U(VI) to U(V) in Goethite.

Over 60 years of nuclear activities have resulted in a global legacy of radioactive wastes, with uranium considered a key radionuclide in both disposal and contaminated land scenarios. With the understanding that U has been incorporated into a range of iron (oxyhydr)oxides, these minerals may be considered a secondary barrier to the migration of radionuclides in the environment. However, the long-term stability of U-incorporated iron (oxyhydr)oxides is largely unknown, with the end-fate of incorporated species potentially impacted by biogeochemical processes. In particular, studies show that significant electron transfer may occur between stable iron (oxyhydr)oxides such as goethite and adsorbed Fe(II). These interactions can also induce varying degrees of iron (oxyhydr)oxide recrystallization (<4% to >90%). Here, the fate of U(VI)-incorporated goethite during exposure to Fe(II) was investigated using geochemical analysis and X-ray absorption spectroscopy (XAS). Analysis of XAS spectra revealed that incorporated U(VI) was reduced to U(V) as the reaction with Fe(II) progressed, with minimal recrystallization (approximately 2%) of the goethite phase. These results therefore indicate that U may remain incorporated within goethite as U(V) even under iron-reducing conditions. This develops the concept of iron (oxyhydr)oxides acting as a secondary barrier to radionuclide migration in the environment.

Biogeochemical Cycling of 99Tc in Alkaline Sediments.

99Tc will be present in significant quantities in radioactive wastes including intermediate-level waste (ILW). The internationally favored concept for disposing of higher activity radioactive wastes including ILW is via deep geological disposal in an underground engineered facility located ∼200-1000 m deep. Typically, in the deep geological disposal environment, the subsurface will be saturated, cement will be used extensively as an engineering material, and iron will be ubiquitous. This means that understanding Tc biogeochemistry in high pH, cementitious environments is important to underpin safety case development. Here, alkaline sediment microcosms (pH 10) were incubated under anoxic conditions under "no added Fe(III)" and "with added Fe(III)" conditions (added as ferrihydrite) at three Tc concentrations (10-11, 10-6, and 10-4 mol L-1). In the 10-6 mol L-1 Tc experiments with no added Fe(III), ∼35% Tc(VII) removal occurred during bioreduction. Solvent extraction of the residual solution phase indicated that ∼75% of Tc was present as Tc(IV), potentially as colloids. In both biologically active and sterile control experiments with added Fe(III), Fe(II) formed during bioreduction and >90% Tc was removed from the solution, most likely due to abiotic reduction mediated by Fe(II). X-ray absorption spectroscopy (XAS) showed that in bioreduced sediments, Tc was present as hydrous TcO2-like phases, with some evidence for an Fe association. When reduced sediments with added Fe(III) were air oxidized, there was a significant loss of Fe(II) over 1 month (∼50%), yet this was coupled to only modest Tc remobilization (∼25%). Here, XAS analysis suggested that with air oxidation, partial incorporation of Tc(IV) into newly forming Fe oxyhydr(oxide) minerals may be occurring. These data suggest that in Fe-rich, alkaline environments, biologically mediated processes may limit Tc mobility.

Global trends and predictors of face mask usage during the COVID-19 pandemic.

BACKGROUND: Guidelines and recommendations from public health authorities related to face masks have been essential in containing the COVID-19 pandemic. We assessed the prevalence and correlates of mask usage during the pandemic. METHODS: We examined a total of 13,723,810 responses to a daily cross-sectional online survey in 38 countries of people who completed from April 23, 2020 to October 31, 2020 and reported having been in public at least once during the last 7 days. The outcome was individual face mask usage in public settings, and the predictors were country fixed effects, country-level mask policy stringency, calendar time, individual sociodemographic factors, and health prevention behaviors. Associations were modeled using survey-weighted multivariable logistic regression. RESULTS: Mask-wearing varied over time and across the 38 countries. While some countries consistently showed high prevalence throughout, in other countries mask usage increased gradually, and a few other countries remained at low prevalence. Controlling for time and country fixed effects, sociodemographic factors (older age, female gender, education, urbanicity) and stricter mask-related policies were significantly associated with higher mask usage in public settings. Crucially, social behaviors considered risky in the context of the pandemic (going out to large events, restaurants, shopping centers, and socializing outside of the household) were associated with lower mask use. CONCLUSION: The decision to wear a face mask in public settings is significantly associated with sociodemographic factors, risky social behaviors, and mask policies. This has important implications for health prevention policies and messaging, including the potential need for more targeted policy and messaging design.