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Suicide rates for adolescents and young adults (AYA) have risen dramatically in recent years – by almost 60% for Americans aged 10–24 years between 2007 and 2018. This increase has occurred for both whites and Blacks, with the rise in suicide among Black youth of particular note. Blacks historically exhibit lower rates of suicide relative to whites and thus, less is known about the etiology of Black suicide. To gain insight into the underlying causes of suicide among AYA, we examine medical examiner reports from the National Violent Death Reporting System (NVDRS) from 2013 to 2019 for over 26,000 Black and white suicide decedents ages 10–29. We apply structural topic modeling (STM) approaches to describe the broad contours of AYA suicide in the United States today. Our findings reveal distinct patterns by race. Guns, violence and the criminal justice system are prominent features of Black suicide, whether through the mechanism used in the suicide, either by firearm or other violent means such as fire or electrocution, the existence of criminal or legal problems/disputes, the location of death in a jail, or the presence of police. In contrast, the narratives of white AYA are more likely to reference mental health or substance abuse problems. Access to resources, as measured by county median household income, overlay these patterns. Themes more prevalent among Blacks are more common in poorer counties; those more prevalent among whites tend to be more common in wealthier counties. Our findings are consistent with other studies that suggest Black people experience greater exposure to violence and other traumas, systemic racism and interpersonal discrimination that may elevate the risk for suicidal behavior. • Latent themes in the narratives of Black and white suicide decedents aged 10–29 years are examined. • Guns, violence, and the criminal justice system are prominent features of Black suicide. • White suicide is more likely to be characterized by mental health or substance abuse problems. • Access to resources, as measured by county median household income, overlay these patterns. • Suicide prevention efforts must be culturally informed. [ABSTRACT FROM AUTHOR]

We analysed changes in the abundance, biomass and cell size of the microbial food web community (bacteria, heterotrophic nanoflagellates, ciliates) at contrasting nutrient concentrations and temperatures during a simulated heat wave. We used 24 mesocosms mimicking shallow lakes in which two nutrient levels (unenriched and enriched by adding nitrogen and phosphorus) and three different temperature scenarios (ambient, IPCC A2 scenario and A2+%50) are simulated (4 replicates of each). Experiments using the mesocosms have been running un-interrupted since 2003. A 1-month heat wave was imitated by an extra 5 °C increase in the previously heated mesocosms (from 1st July to 1st August 2014). Changes in water temperature induced within a few days a strong effect on the microbial food web functioning, demonstrating a quick response of microbial communities to the changes in environment, due to their short generation times. Warming and nutrients showed synergistic effects. Microbial assemblages of heterotrophic nanoflagellates and ciliates responded positively to the heating, the increase being largest in the enriched mesocosms. The results indicate that warming and nutrients in combination can set off complex interactions in the microbial food web functioning. [ABSTRACT FROM AUTHOR]

The knowledge of patient-centered outcomes concerning the consequences of root canal treatment in daily life is limited. The treatment option is often tooth extraction with possible prosthetic replacement. This study aimed to achieve a greater understanding of the patient perspective by evaluating the effect of root canal treatment in terms of quality of life and quality-adjusted life year (QALY) weights in comparison with patients who underwent tooth extraction. Patients with either root canal treatment or extraction were recruited from 6 clinics in the general public dental service during a predetermined period of 8 weeks. Three different instruments were used: the Oral Health Impact Profile evaluating the oral health–related quality of life (OHRQOL), the EQ-5D-5L evaluating health-related quality of life (HRQOL) and QALY weights, and a disease-specific questionnaire evaluating satisfaction regarding the root canal treatment. The evaluation was assessed at the initiation of treatment and after 1 month. Patient-based and tooth-specific characteristics were obtained from the dental records. Eighty-five patients were included. The distribution between sexes was even, with 43 women and 42 men. The mean age was 51.1 years. Forty-eight patients (56.5%) had a tooth extraction, and 37 patients (43.5%) initiated root canal treatment. The response rate for the questionnaire at baseline was 95.3%, and at the 1-month follow-up, it was 74.1%. Two relevant and comparable groups were obtained after exclusion of the extracted third molars (n = 20), resulting in 65 patients for further analyses. At follow-up, the patients who initiated root canal treatment registered a significant improvement in perceived HRQOL according to the QALY weights (P =.02 and P <.01, respectively). Patients initiating root canal treatment reported generally high satisfaction. A cohort of patients either initiating root canal treatment or tooth extraction as a control group was established. Initiating root canal treatment had a positive impact on perceived HRQOL. The included patients in general dental practice registered overall high satisfaction regarding root canal treatment. [ABSTRACT FROM AUTHOR]

Spearcons (time-compressed speech) may be a viable auditory display for patient monitoring; however, the impact of concurrent linguistic tasks remains unexamined. We tested whether different concurrent linguistic tasks worsen participants' identification of spearcons. Experiment 1 tested non-clinician participants' identification of multiple-patient spearcons representing 2 vital signs of 5 patients while participants performed no concurrent task, reading, or saying linguistic tasks. Experiment 2 tested non-clinician participants' identification of 48 single-patient spearcons while they performed no concurrent task, reading, listening, and saying linguistic tasks. In Experiment 1 the saying task worsened participants' identification of spearcons compared with no concurrent task or reading. In Experiment 2, the saying and listening tasks reduced participants' accuracy at identifying spearcons, but the reading task did not. Listening affected identification accuracy no differently than the saying task did. Concurrent auditory linguistic tasks worsen participants' identification of spearcons, probably due to auditory modality interference in verbal working memory. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microcystis morphospecies respond to pH, temperature, and nutrients differently. • NCSC positively correlate with M. ichtyoblabe , M. aeruginosa , and M. smithii. • Colonial sheath abundances positively correlate with M.wesenbergii abundances. • Colonial sheaths with remaining cells suited for Microcystis dispersal. • Imaging flow cytometry are available for early indication of Microcystis detection and dispersal. The alarming increase in the frequency of blooms of Microcystis in freshwater lakes and reservoirs occurs worldwide, with major implications for their ecosystem functioning and water quality. The dominance of Microcystis is tightly related to colonial formation by Microcystis. However, studies of the colonial development of Microcystis morphospecies are rare. This research applied FlowCAM-based imaging flow cytometry to analyze the development of Microcystis morphospecies in the mesocosms mimicking eutrophic shallow lakes and the effect of temperature changes. A significant positive association was found between M. ichtyoblabe , M. aeruginosa , and M. smithii colonies, particularly in the high-temperature tanks, suggesting that these morphospecies belong to one ecocluster, which supports the hypothesis of the central transition pathways of colonial Microcystis. The small colonial clusters of Microcystis cells represented an important stage in the sequence of Microcystis bloom and were associated with the development of colonial forms. A correlation analysis showed that the higher pH was positively correlated with the abundance of M.wesenbergii independently of temperature changes. The colonial sheaths' abundances increased following a maximum of M.wesenbergii abundance, reaching significant numbers (thousands), and a majority of sheaths contained at least some Microcystis cells. We hypothesize that colonial sheaths may be crucial at Microcystis spp. dispersal and represent an obligatory stage of colonies development. The sheaths may protect Microcystis cells against environmental stress factors, improve cell survival at low nutrient levels, and participate in Microcystis dispersal and spreading. Our findings can be applicable to early CyanoHAB detection and management of Microcystis dispersal. [ABSTRACT FROM AUTHOR]

Shallow lakes produce and emit substantial amounts of methane (CH 4). Part of the CH 4 produced in lakes is consumed by methane-oxidizing bacteria (MOB) present in the sediment and water column, thus reducing the overall CH 4 emissions. However, the role of aquatic plants as habitat for CH 4 oxidation by MOB is poorly understood. In this study, we compared CH 4 oxidation rates and MOB abundance associated with different types of aquatic plants (periphyton, filamentous algae, and both above-ground macrophytes and their rhizosphere). The plants were collected from shallow lake mesocosms exposed to experimental nutrient enrichment and warming treatments for 17 years prior to this study. Incubations of all sampled plants showed CH 4 oxidation, with above-ground macrophyte tissue and filamentous algae having the highest rates of up to 0.25 µmol CH 4 h−1 g−1 dw. Oxidation rates associated with macrophytes were species dependent, with consumption rates on rhizospheres of Potamogeton crispus higher than those on Elodea canadensis. The increase in nutrients and dissolved CH 4 in the water tended to increase MOB abundance and activity for all plant types, while no effect of long term warming was detectable. Our results showed that MOB associated with periphyton, filamentous algae and macrophytes oxidize CH 4 in shallow lakes at different rates across species or plant types. We also found that high macrophyte biomass is associated with reduced CH 4 concentration in the water. This study shows that CH 4 oxidation occurs on many plant surfaces but that oxidation rates alone cannot explain the reduced CH 4 emissions at higher plant biomass. [ABSTRACT FROM AUTHOR]

Accelerating ice loss during recent years has made the Greenland Ice Sheet one of the largest single contributors to global sea level rise, accounting for 0.5 of the total 3.2 mm yr −1 . This loss is predicted to continue and will most likely increase in the future as a consequence of global warming. However, the sensitivity of glaciers and ice caps (GICs) in Greenland to prolonged warm periods is less well constrained and geological records documenting the long-term glacial history are needed to put recent observations into a broader perspective. Here we report the results from three proglacial lakes where fluctuations in local glaciers located at different altitudes in Kobbefjord, southwest Greenland have been recorded. Our results show that the lakes received meltwater from the initial deglaciation of the area ∼9.2 cal. ka BP until ∼8.7–7.9 cal. ka BP when the meltwater input ceased as the glaciers most likely disappeared. Regrowth of glaciers began again at ∼5.5 cal. ka BP at ∼1370 m a.s.l., ∼3.6 cal. ka at ∼1170 m a.s.l., and ∼1.6 cal. ka BP at ∼1000 m a.s.l., clearly reflecting strong altitudinal control of the GIC response to Neoglacial cooling. Our results highlight that GICs in Kobbefjord, southwest Greenland are primarily influenced by changes in summer air temperatures and winter precipitation and that they are facing a rapid decay that most likely will result in their disappearance within the next centuries as a consequence of global warming. If current 21st Century retreat rates continue, the GICs in the study area will be completely gone in ∼30–90 years, with the smallest GICs disappearing first. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of ecosystem services (ESs) is crucial for sustainable resource management. Palaeolimnological records have a great potential to reveal long-term variations and dynamic interactions in ESs, especially supporting/regulating services, which are not easily quantified by documentary records. To elucidate the variations between eight important ESs in shallow lake ecosystems, we combined documentary records with palaeolimnological proxies (covering the past 100 years) from two typical lakes (Lakes Taibai and Zhangdu) of the Yangtze River basin. Although all supporting services and some provisioning services have increased, the regulating services of the two lakes have markedly declined, in particular since the 1950s. Human activities, including hydrological intervention, nutrient input and land-use change, were identified as the main factors behind the observed variations. Both in Lake Taibai and Zhangdu, primary production and biodiversity (supporting services) have increased (synergies), whereas climate and water purification (regulating services) have significantly decreased (tradeoffs) since the 1950s when attempts were made by the local population to reach a higher land/fish ESs level. By considering long-term records, dynamic tradeoff and synergy relationship between various ESs relative to different types of human “modification” in a temporal perspective, we suggest valuable information can be gained in future lake management initiatives. [ABSTRACT FROM AUTHOR]

Highlights: [•] PBDE concentrations are comparable to the limited data available for the Great Lakes. [•] ΣBDE concentrations in water samples showed TSS dependence. [•] ΣBDE concentrations showed seasonal trends: higher in colder than in warmer periods. [•] Generally higher BDE-47:99 ratios in warmer than colder months. [•] BDE-47:99 ratios decreased significantly with increasing TSS content of samples. [Copyright &y& Elsevier]

• A new ploidy database provides cytotype information for 1574 macrophyte species. • Polyploids occupy larger geographical ranges than haploid/diploid macrophytes. • Differing latitudinal patterns exist between haploid/diploid and polyploid species. • Temperature and evapotranspiration drive global macrophyte cytotype patterns. • Polyploidy in macrophytes may be an adaptation to survive in harsh environments. Despite the increasing evidence that ploidy is a factor of importance for environmental adaptation, little work has hitherto been done about cytotype patterns in aquatic plants. We tested a set of hypotheses concerning the drivers of ploidy in macrophyte communities at worldwide scale, and also how ploidy state may be related to other attributes of aquatic plants such as community diversity, species range size and invasiveness. We built a global ploidy database with 1574 species (representing 45.0 % of the known total global pool) and allocated ploidy state to species occurring in 238 10 × 10° gridcells worldwide. We used Boosted Regression Trees Analysis to analyse the relationship of 16 global-scale spatial, landscape, environmental and biotic variables with ploidy state. Our results demonstrate that (1) Polyploid and mixed ploidy species occupied larger geographical ranges than haploid/diploid species. (2) There were contrasting latitudinal patterns between haploid/diploid and polyploid species with polyploidy increasing in importance with distance from the equator, while species richness measures also influenced ploidy state. (3) Climatic factors, especially temperature and evapotranspiration, are congruent with macrophyte species ploidy state, across the planet. Our data support the assertion that increased chromosome number is an adaptation associated with plant survival of harsh environmental conditions, especially in environmentally-stressed high latitudes. Our findings increase the generality of knowledge of the large-scale factors that drive cytotype patterns in vascular plant species at global scale. The ploidy database provides a resource to support further studies about the effects of varying environmental conditions on ploidy state in aquatic plants, at differing scales. [ABSTRACT FROM AUTHOR]

Lakes actively transform nitrogen (N) and emit disproportionately large amounts of N 2 O relative to their surface area. Studies have investigated the relative importance of denitrification or nitrification on N 2 O emissions; however, the linkage between N 2 O efflux and dissolved organic nitrogen (DON) and carbon (DOC) remains largely unknown. Long-term (2012–2017) seasonal field observations and a series of degradation experiments were used to unravel how DON composition impacts N 2 O emissions from Lake Taihu, China. In the northwestern part of the lake, large riverine inflow and high N 2 O emissions occur in all seasons (24.6 ± 25.2 μmol m−2 d−1), coincident with high levels of terrestrial DON and DOC here. The degradation of labile DON and DOC likely enhanced ammonification as supported by the correlations between NH 4 +-N and DON, DOC, a (350), and terrestrial humic-like C3. The area with large riverine inputs in the northwestern part of the lake was characterized by low DO which may enhance incomplete aerobic nitrification and incomplete denitrification, both leading to N 2 O production. Twenty days laboratory experiments indicated greater N 2 O production in the northwest inflow samples (N 2 O on day 20: 120.9 nmol L−1 and 17.3 nmol L−1 for bio- and photo-degradation samples, respectively) compared with the central lake samples (N 2 O on day 20: 20.3 nmol L−1 and 12.3 nmol L−1 for bio- and photo-degradation samples, respectively), despite both having low Chl- a. Our DON and DOC degradation experiments confirmed the occurrence of ammonification along with consumption of NH 4 +-N and thereafter NO 3 −-N. Our results collectively suggest that terrestrial DON fueled ammonification, enhanced nitrification and incomplete denitrification, and thereby became an important contributor to the N 2 O efflux from Lake Taihu. Unlabelled Image • Terrestrial DON input in the inflowing river mouths likely enhanced ammonification. • DOM degradation in the inflow-affected areas fuels oxygen consumption. • DO depletion fuels incomplete aerobic nitrification and nitrifier-denitrification. • Terrestrial DON input potentially fueling N 2 O efflux from Lake Taihu. [ABSTRACT FROM AUTHOR]

Shallow lakes are hotspots for carbon processing and important natural sources of methane (CH 4) emission. Ebullitive CH 4 flux may constitute the overwhelming majority of total CH 4 flux, but the episodic nature of ebullition events makes determining both quantity and the controlling factors challenging. Here we used the world's longest running shallow-lake mesocosm facility, where the experimental treatments are low and high nutrients crossed with three temperatures, to investigate the quantity and drivers of CH 4 ebullition. The mean CH 4 ebullition flux in the high nutrient treatment (41.5 ± 52.3 mg CH 4 –C m−2 d−1) mesocosms was significantly larger than in the low nutrient treatment (3.6 ± 5.4 mg CH 4 –C m−2 d−1) mesocosms, varying with temperature scenarios. Over eight weeks from June to August covered here warming resulted in a weak, but insignificant enhancement of CH 4 ebullition. We found significant positive relationships between ebullition and chlorophyll- a , dissolved organic carbon (DOC), biodegradable DOC, δ2H, δ18O and δ13C-DOC, autochthonous dissolved organic matter (DOM) fluorescent components, and a fraction of lipids, proteins, and lignins revealed using ultrahigh-resolution mass spectrometry, and a negative relationship between ebullitive CH 4 flux and the percentage volume inhabited of macrophytes. A 24 h laboratory bio-incubation experiment performed at room temperature (20 ± 2 °C) in the dark further revealed a rapid depletion of algal-DOM concurrent with a massive increased CH 4 production, whereas soil-derived DOM had a limited effect on CH 4 production. We conclude that eutrophication likely induced the loss of macrophytes and increase in algal biomass, and the resultant accumulation algal derived bio-labile DOM potentially drives enhanced outgassing of ebullitive CH 4 from the shallow-lake mesocosms. Image 1 • CH 4 ebullition enhanced with increasing Chl- a , DOC, BDOC and autochthonous DOM. • Highly biolabile protein-rich components are likely biodegraded from algal scums. • Autochthonous algal-derived DOC share enriched δ2H, δ18O and δ13C-DOC. • Markedly increased CH 4 concurrent with rapid depletion of highly biolabile algal-DOM. [ABSTRACT FROM AUTHOR]