Understanding the transmission of bacterial agents of sapronotic diseases using an ecosystem-based approach: A first spatially realistic metacommunity model.

Pathogens such as bacteria, fungi and viruses are important components of soil and aquatic communities, where they can benefit from decaying and living organic matter, and may opportunistically infect human and animal hosts. One-third of human infectious diseases is constituted by sapronotic disease agents that are natural inhabitants of soil or aquatic ecosystems. They are capable of existing and reproducing in the environment outside of the host for extended periods of time. However, as ecological research on sapronosis is infrequent and epidemiological models are even rarer, very little information is currently available. Their importance is overlooked in medical and veterinary research, as well as the relationships between free environmental forms and those that are pathogenic. Here, using dynamical models in realistic aquatic metacommunity systems, we analyze sapronosis transmission, using the human pathogen Mycobacterium ulcerans that is responsible for Buruli ulcer. We show that the persistence of bacilli in aquatic ecosystems is driven by a seasonal upstream supply, and that the attachment and development of cells to aquatic living forms is essential for such pathogen persistence and population dynamics. Our work constitutes the first set of metacommunity models of sapronotic disease transmission, and is highly flexible for adaptation to other types of sapronosis. The importance of sapronotic agents on animal and human disease burden needs better understanding and new models of sapronosis disease ecology to guide the management and prevention of this important group of pathogens.

Older Age is Associated With Positional Obstructive Sleep Apnea.

OBJECTIVES: Untreated obstructive sleep apnea (OSA) is associated with cognitive dysfunction; however studies report low adherence rates to standard continuous positive airway pressure (CPAP) treatment in the elderly. Positional OSA (p-OSA) is a subset that can be cured by positional therapy of avoiding supine sleep. However, there is no well-established criteria to identify patients who could benefit from positional therapy as an alternative or adjunct to CPAP. This study investigates if older age is related to p-OSA using different diagnostic criteria. DESIGN: Cross-sectional study. PARTICIPANTS: Participants aged 18 years old or more who underwent polysomnography for clinical reasons at University of Iowa Hospitals and Clinics over a 1-year period from July 2011 to June 2012 were enrolled retrospectively. MEASUREMENT: P-OSA was defined as a high supine-position dependency of obstructive breathing events with potential resolution of OSA in nonsupine positions [high apnea-hypopnea index on supine positions (s-AHI)/ AHI on nonsupine positions (ns0AHI) combined with ns-AHI < 5/hour]. Different cutoff points (2, 3, 5, 10, 15, 20) were applied to determine a meaningful ratio of supine-position dependency of obstructions [s-AHI/ns-AHI]. We compared the proportion of patients with p-OSA between the older age group (≥65 years old) and the propensity score (PS)-matched (upto 1:4) younger age group (<65 years old) using logistic regression analyses. RESULTS: In total, 346 participants were included. The older age group had a higher s-AHI/ns-AHI ratio than the younger age group (mean 31.6 [SD 66.2] versus 9.3 [SD 17.4], median 7.3 [interquartile range [IQR], 3.0-29.6) versus 4.1 (IQR, 1.9-8.7). After PS-matching, the older age group (n = 44) had higher proportion of those with a high s-AHI/ns-AHI ratio and ns-AHI< 5/hour compared with the younger age group (n = 164). (s-AHI/ns-AHI≥10: 54.6% versus 31.7%, OR 2.44 (95% CI, 1.22-4.90); s-AHI/ns-AHI≥15: 47.7% versus 26.2%, OR 2.24 (95% CI, 1.14-4.37); s-AHI/ns-AHI≥20: 40.9% versus 19.5%, OR 2.52 (95% CI, 1.22-5.20)) CONCLUSION: Older patients with OSA are more likely to have severe position dependent OSA, that is potentially more treatable with positional therapy. Thus, clinicians treating older, cognitively impaired geriatric patients unable to tolerate CPAP therapy should consider positional therapy as an adjunct or alternative.

Cortical functional connectivity indexes arousal state during sleep and anesthesia.

Disruption of cortical connectivity likely contributes to loss of consciousness (LOC) during both sleep and general anesthesia, but the degree of overlap in the underlying mechanisms is unclear. Both sleep and anesthesia comprise states of varying levels of arousal and consciousness, including states of largely maintained conscious experience (sleep: N1, REM; anesthesia: sedated but responsive) as well as states of substantially reduced conscious experience (sleep: N2/N3; anesthesia: unresponsive). Here, we tested the hypotheses that (1) cortical connectivity will exhibit clear changes when transitioning into states of reduced consciousness, and (2) these changes will be similar for arousal states of comparable levels of consciousness during sleep and anesthesia. Using intracranial recordings from five adult neurosurgical patients, we compared resting state cortical functional connectivity (as measured by weighted phase lag index, wPLI) in the same subjects across arousal states during natural sleep [wake (WS), N1, N2, N3, REM] and propofol anesthesia [pre-drug wake (WA), sedated/responsive (S), and unresponsive (U)]. Analysis of alpha-band connectivity indicated a transition boundary distinguishing states of maintained and reduced conscious experience in both sleep and anesthesia. In wake states WS and WA, alpha-band wPLI within the temporal lobe was dominant. This pattern was largely unchanged in N1, REM, and S. Transitions into states of reduced consciousness N2, N3, and U were characterized by dramatic changes in connectivity, with dominant connections shifting to prefrontal cortex. Secondary analyses indicated similarities in reorganization of cortical connectivity in sleep and anesthesia. Shifts from temporal to frontal cortical connectivity may reflect impaired sensory processing in states of reduced consciousness. The data indicate that functional connectivity can serve as a biomarker of arousal state and suggest common mechanisms of LOC in sleep and anesthesia.

Biodegradation of Polystyrene by Dark ( Tenebrio obscurus) and Yellow ( Tenebrio molitor) Mealworms (Coleoptera: Tenebrionidae).

Yellow mealworms (larvae of Tenebrio molitor, Coleoptera: Tenebrionidae) have been proven to be capable of biodegrading polystyrene (PS) products. Using four geographic sources, we found that dark mealworms (larvae of Tenebrio obscurus) ate PS as well. We subsequently tested T. obscurus from Shandong, China for PS degradation capability. Our results demonstrated the ability for PS degradation within the gut of T. obscurus at greater rates than T. molitor. With expanded PS foam as the sole diet, the specific PS consumption rates for T. obscurus and T. molitor at similar sizes (2.0 cm, 62-64 mg per larva) were 32.44 ± 0.51 and 24.30 ± 1.34 mg 100 larvae-1 d-1, respectively. After 31 days, the molecular weight ( Mn) of residual PS in frass (excrement) of T. obscurus decreased by 26.03%, remarkably higher than that of T. molitor (11.67%). Fourier transform infrared spectroscopy (FTIR) indicated formation of functional groups of intermediates and chemical modification. Thermo gravimetric analysis (TGA) suggested that T. obscurus larvae degraded PS effectively based on the proportion of PS residue. Co-fed corn flour to T. obscurus and wheat bran to T. molitor increased total PS consumption by 11.6% and 15.2%, respectively. Antibiotic gentamicin almost completely inhibited PS depolymerization. High-throughput sequencing revealed significant shifts in the gut microbial community in both Tenebrio species that were associated with the PS diet and PS biodegradation, with changes in three predominant families (Enterobacteriaceae, Spiroplasmataceae, and Enterococcaceae). The results indicate that PS biodegradability may be ubiquitous within the Tenebrio genus which could provide a bioresource for plastic waste biodegradation.

Obstructive sleep apnea and risk for late-life depression.

BACKGROUND: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by repetitive pharyngeal collapse. Because of the association between OSA, ischemia, and late-life depression, we hypothesized that older patients with OSA would have a higher prevalence of depression relative to their younger counterparts. METHODS: We retrospectively reviewed charts of patients evaluated at the Sleep Disorders Center (SDC) at University of Iowa Hospitals and Clinics. A total of 617 patients age≥18 seen at SDC for diagnostic and therapeutic sleep studies were identified. Patients with a chart diagnosis of depressive disorder or treatment with antidepressants were identified as having a depressive disorder. Patients with an Apnea/Hypopnea Index≥5 were identified as having OSA. RESULTS: No evidence of an escalating prevalence of depression with age was found in patients with OSA relative to those without the disorder. Prevalence of depression was similar in the OSA and the nonapnea groups (40.9% vs 40.3%, respectively; χ2=0.02; df=1; P=.89). Individuals with OSA had a significantly higher body mass index and greater number of chart diagnoses of hypertension, diabetes mellitus, and coronary artery disease compared with the nonapnea group. CONCLUSIONS: The prevalence of depression among individuals with OSA does not appear to be moderated by age. Similarly high rates of depression were observed across the population of individuals referred for sleep studies, whether or not they were diagnosed with OSA.

Structural roles of Ump1 and ß-subunit propeptides in proteasome biogenesis.

The yeast pre1-1(ß4-S142F) mutant accumulates late 20S proteasome core particle precursor complexes (late-PCs). We report a 2.1 Å cryo-EM structure of this intermediate with full-length Ump1 trapped inside, and Pba1-Pba2 attached to the α-ring surfaces. The structure discloses intimate interactions of Ump1 with ß2- and ß5-propeptides, which together fill most of the antechambers between the α- and ß-rings. The ß5-propeptide is unprocessed and separates Ump1 from ß6 and ß7. The ß2-propeptide is disconnected from the subunit by autocatalytic processing and localizes between Ump1 and ß3. A comparison of different proteasome maturation states reveals that maturation goes along with global conformational changes in the rings, initiated by structuring of the proteolytic sites and their autocatalytic activation. In the pre1-1 strain, ß2 is activated first enabling processing of ß1-, ß6-, and ß7-propeptides. Subsequent maturation of ß5 and ß1 precedes degradation of Ump1, tightening of the complex, and finally release of Pba1-Pba2.

Soil-dwelling grub larvae of Protaetia brevitarsis biodegrade polystyrene: Responses of gut microbiome and host metabolism.

Plastic pollution poses a significant threat to terrestrial ecosystems, yet the potential for soil fauna to contribute to plastic biodegradation remains largely unexplored. In this study, we reveal that soil-dwelling grubs, Protaetia brevitarsis larvae, can effectively biodegrade polystyrene (PS) plastics. Over a period of 4 weeks, these grubs achieved a remarkable 61.5 % reduction in PS foam mass. This biodegradation was confirmed by the depolymerization of ingested PS, formation of oxidative functional groups, noticeable chemical modifications, and an increase of δ13C of residual PS in frass. Additionally, antibiotic treatment to suppress gut microbes led to variations in the biodegradation process. PS ingestion induced a significant shift in the gut microbiome, promoting the growth of degradation-related bacteria such as Promicromonosporaceae, Bacillaceae, and Paenibacillaceae. Furthermore, the digestion of plastic triggered extensive metabolomic reprogramming of grubs' intestines, enhancing redox capabilities and facilitating PS biodegradation. These results indicate that responsive adaptation of both the gut microbiome and the host's intestinal metabolism contributes to PS degradation. Collectively, these findings demonstrate P. brevitarsis larvae's capability to alleviate soil plastic pollution, and highlight the potential of researching soil fauna further for sustainable plastic waste management solutions.

Cockroach Blaptica dubia biodegrades polystyrene plastics: Insights for superior ability, microbiome and host genes.

The report demonstrated that a member of cockroach family, Blaptica dubia (Blattodea: Blaberidae) biodegraded commercial polystyrene (PS) plastics with Mn of 20.3 kDa and Mw of 284.9 kDa. The cockroaches digested up to 46.6 % of ingested PS within 24 h. The biodegradation was confirmed by the 13C isotopic shift of the residual PS in feces versus pristine PS (Δ Î´13C of 2.28 ‰), reduction of molecular weight and formation of oxidative functional groups in the residual PS. Further tests found that B.dubia cockroaches degraded all eight high purity PS microplastics with low to ultra-high molecular weights (MW) at 0.88, 1.20, 3.92, 9.55, 62.5, 90.9, 524.0, and 1040 kDa, respectively, with superior biodegradation ability. PS depolymerization/biodegradation pattern was MW-dependent. Ingestion of PS shifted gut microbial communities and elevated abundances of plastic-degrading bacterial genes. Genomic, transcriptomic and metabolite analyses indicated that both gut microbes and cockroach host contributed to digestive enzymatic degradation. PS plastic diet promoted a highly cooperative model of gut digestive system. Weighted gene co-expression network analysis revealed different PS degradation patterns with distinct MW profiles in B. dubia. These results have provided strong evidences of plastic-degrading ability of cockroaches or Blaberidae family and new understanding of insect and their microbe mediated biodegradation of plastics.

Ecological and evolutionary perspectives advance understanding of mycobacterial diseases.

Predicting the outbreak of infectious diseases and designing appropriate preventive health actions require interdisciplinary research into the processes that drive exposure to and transmission of disease agents. In the case of mycobacterial diseases, the epidemiological understanding of the scientific community hitherto was based on the clinical studies of infections in vertebrates. To evaluate the information gained by comprehensively accounting for the ecological and evolutionary constraints, we conducted literature searches assessing the role of mycobacteria interactions with non-vertebrate species in the origin of their pathogenicity and variations in disease risk. The reviewed literature challenges the current theory of person-to-person transmission for several mycobacterial infections. Furthermore, the findings suggest that diverse non-vertebrate organisms influence virulence, mediate transmission, and contribute to pathogen abundance in relation to vertebrate exposure. We advocate that an ecological and evolutionary framework provides novel insights to support a more comprehensive understanding of the prevention and management of diseases in vertebrates.

Emerging infectious diseases and new pandemics: dancing with a ghost! Lessons in inter- and transdisciplinary research in French Guiana, South America.

In light of current international public health challenges, calls for inter- and transdisciplinary research are increasing, particularly in response to complex and intersecting issues. Although widely used under the One Health flag, it is still unclear how inter- and transdisciplinary science should be applied to infectious disease research, public health, and the different stakeholders. Here, we present and discuss our common scientific and biomedical experience in French Guiana, South America to conduct and enrich research in vector-borne and zoonotic infectious diseases, with the aim to translate findings to public health and political stakeholders. We highlight the successful progressive dissolution of disciplinary boundaries that go beyond One Health positive-driven assumptions and argue that specific local conditions, as well as strong support from research and medical institutions, have facilitated an emulsion toward inter- and transdisciplinary science. This argument is intended to improve responses to public health concerns in French Guiana and other countries and regions of the world.

Stabilization of membrane topologies by proteinaceous remorin scaffolds.

In plants, the topological organization of membranes has mainly been attributed to the cell wall and the cytoskeleton. Additionally, few proteins, such as plant-specific remorins have been shown to function as protein and lipid organizers. Root nodule symbiosis requires continuous membrane re-arrangements, with bacteria being finally released from infection threads into membrane-confined symbiosomes. We found that mutations in the symbiosis-specific SYMREM1 gene result in highly disorganized perimicrobial membranes. AlphaFold modelling and biochemical analyses reveal that SYMREM1 oligomerizes into antiparallel dimers and may form a higher-order membrane scaffolding structure. This was experimentally confirmed when expressing this and other remorins in wall-less protoplasts is sufficient where they significantly alter and stabilize de novo membrane topologies ranging from membrane blebs to long membrane tubes with a central actin filament. Reciprocally, mechanically induced membrane indentations were equally stabilized by SYMREM1. Taken together we describe a plant-specific mechanism that allows the stabilization of large-scale membrane conformations independent of the cell wall.

Linking the Mycobacterium ulcerans environment to Buruli ulcer disease: Progress and challenges.

Buruli ulcer (BU), the second most common mycobacterial disease in West Africa, is a necrotizing skin disease that can lead to high morbidity in affected patients. The disease is caused by Mycobacterium ulcerans (MU), whose major virulence factor is mycolactone. Although early infection can be treated with antibiotics, an effective preventative strategy is challenging due to unknown reservoir(s) and unresolved mode(s) of transmission. Further, disease occurrence in remote locations with limited access to health facilities further complicates disease burden and associated costs. We discuss here MU transmission hypotheses and investigations into environmental reservoirs and discuss successes and challenges of studying MU and Buruli ulcer across human, animal, and environmental interfaces. We argue that a One Health approach is needed to advance the understanding of MU transmission and designing management scenarios that prevent and respond to epidemics. Although previous work has provided significant insights into risk factors, epidemiology and clinical perspectives of disease, understanding the bacterial ecology, environmental niches and role of mycolactone in natural environments and during infection of the human host remains equally important to better understanding and preventing this mysterious disease.

Acute inorganic nitrate supplementation and the hypoxic ventilatory response in patients with obstructive sleep apnea.

Patients with obstructive sleep apnea (OSA) have increased cardiovascular disease risk largely attributable to hypertension. Heightened peripheral chemoreflex sensitivity (i.e., exaggerated responsiveness to hypoxia) facilitates hypertension in these patients. Nitric oxide blunts the peripheral chemoreflex, and patients with OSA have reduced nitric oxide bioavailability. We therefore investigated the dose-dependent effects of acute inorganic nitrate supplementation (beetroot juice), an exogenous nitric oxide source, on blood pressure and cardiopulmonary responses to hypoxia in patients with OSA using a randomized, double-blind, placebo-controlled crossover design. Fourteen patients with OSA (53 ± 10 yr, 29.2 ± 5.8 kg/m2, apnea-hypopnea index = 17.8 ± 8.1, 43%F) completed three visits. Resting brachial blood pressure and cardiopulmonary responses to inspiratory hypoxia were measured before, and 2 h after, acute inorganic nitrate supplementation [∼0.10 mmol (placebo), 4.03 mmol (low dose), and 8.06 mmol (high dose)]. Placebo increased neither plasma [nitrate] (30 ± 52 to 52 ± 23 µM, P = 0.26) nor [nitrite] (266 ± 153 to 277 ± 164 nM, P = 0.21); however, both increased following low (29 ± 17 to 175 ± 42 µM, 220 ± 137 to 514 ± 352 nM) and high doses (26 ± 11 to 292 ± 90 µM, 248 ± 155 to 738 ± 427 nM, respectively, P < 0.01 for all). Following placebo, systolic blood pressure increased (120 ± 9 to 128 ± 10 mmHg, P < 0.05), whereas no changes were observed following low (121 ± 11 to 123 ± 8 mmHg, P = 0.19) or high doses (124 ± 13 to 124 ± 9 mmHg, P = 0.96). The peak ventilatory response to hypoxia increased following placebo (3.1 ± 1.2 to 4.4 ± 2.6 L/min, P < 0.01) but not low (4.4 ± 2.4 to 5.4 ± 3.4 L/min, P = 0.11) or high doses (4.3 ± 2.3 to 4.8 ± 2.7 L/min, P = 0.42). Inorganic nitrate did not change the heart rate responses to hypoxia (beverage-by-time P = 0.64). Acute inorganic nitrate supplementation appears to blunt an early-morning rise in systolic blood pressure potentially through suppression of peripheral chemoreflex sensitivity in patients with OSA.NEW & NOTEWORTHY The present study is the first to examine the acute effects of inorganic nitrate supplementation on resting blood pressure and cardiopulmonary responses to hypoxia (e.g., peripheral chemoreflex sensitivity) in patients with obstructive sleep apnea (OSA). Our data indicate inorganic nitrate supplementation attenuates an early-morning rise in systolic blood pressure potentially attributable to blunted peripheral chemoreflex sensitivity. These data show proof-of-concept that inorganic nitrate supplementation could reduce the risk of cardiovascular disease in patients with OSA.

Quantification of the effect of culturing temperature on salt-induced heat resistance of bacillus species.

Short- and long-term exposure to mild stress conditions can activate stress adaptation mechanisms in pathogens, resulting in a protective effect toward otherwise lethal stresses. The mesophilic strains Bacillus cereus ATCC 14579 and ATCC 10987 and the psychrotolerant strain B. weihenstephanensis KBAB4 were cultured at 12 degrees C and 30 degrees C until the exponential growth phase (i) in the absence of salt, (ii) in the presence of salt, and (iii) with salt shock after they reached the exponential growth phase and subsequently heat inactivated. Both the first-order model and the Weibull model were fitted to the inactivation kinetics, and statistical indices were calculated to select for each condition the most appropriate model to describe the inactivation data. The third-decimal reduction times (which reflected the times needed to reduce the initial number of microorganisms by three decimal powers) were determined for quantitative comparison. The heat resistance of both mesophilic strains increased when cells were salt cultured and salt shocked at 30 degrees C, whereas these salt-induced effects were not significant for the psychrotolerant strain. In contrast, only the psychrotolerant strain showed salt-induced heat resistance when cells were cultured at 12 degrees C. Therefore, culturing temperature and strain diversity are important aspects to address when adaptive stress responses are quantified. The activated adaptive stress response had an even larger impact on the number of surviving microorganisms when the stress factor (i.e., salt) was still present during inactivation. These factors should be considered when stress-integrated predictive models are developed that can be used in the food industry to balance and optimize processing conditions of minimally processed foods.

Management of sleep disorders in stroke.

OPINION STATEMENT: Scientific studies have proven a very strong association between stroke and obstructive sleep apnea (OSA). The prevalence of OSA is very high in patients with acute stroke, and untreated OSA is a stroke risk factor. In the stroke patient population, symptoms of OSA may atypically appear as isolated insomnia, hypersomnia, a dysfunction of circadian rhythm, a parasomnia, or a sleep-related movement disorder. Thus, we believe that in patients with acute stroke, OSA should be addressed first, using full in-laboratory, attended polysomnography (PSG), before other specific sleep disorders are aggressively addressed with specific therapeutic interventions. When OSA is diagnosed, supportive techniques including the application of continuous positive airway pressure (CPAP) therapy, positional therapies, or both should be considered first-line treatments. If OSA is ruled out by PSG, the therapeutic emphasis for sleep-related complaints is routinely based on instituting good sleep hygiene practices and using cognitive behavioral techniques (cognitive therapies, sleep restriction, stimulus control, and progressive relaxation therapies) because patients with stroke may be prone to the adverse effects of many of the medications that are otherwise routinely prescribed for a variety of specific sleep disorders.

Cold Case Experiment Demonstrates the Potential Utility of Aquatic Microbial Community Assembly in Estimating a Postmortem Submersion Interval.

Microbial community assembly (MCA) of both human and nonhuman animal carcasses provides indicators useful for estimating the postmortem interval (PMI) in terrestrial settings. However, there are fewer studies estimating postmortem submersion intervals (PMSIs) in aquatic habitats. No aquatic studies to date assessed MCA in the context of a death investigation, with all previous studies focusing on important basic ecological questions. Within the context of a cold case investigation, we performed an experiment using replicate adult swine carcasses to describe postmortem MCA variability within a nonflowing aquatic habitat. Using high-throughput sequencing of carcass postmortem microbiomes, we described MCA variability and identified key taxa associated with decomposition in an aquatic habitat similar to the cold case body recovery site. We also modeled key taxa for estimating PMSIs, modeling within ±3 days (mean square error) postmortem using random forest regression. Our findings show significant changes in microbial communities as decomposition progressed, and several taxa were identified as important indicator taxa which may be useful for future estimates of PMSI. While descriptive, this study provides initial findings quantifying MCA variability within a nonflowing aquatic habitat. Within the context of the cold case investigation, we discuss how postmortem microbial samples collected at the time of body recovery could have been an important piece of evidence for understanding the PMSI of recovered remains. Additional experimental studies are needed to explicitly test and identify mechanisms associated with postmortem MCA variability in other habitats and under different temperature (e.g., seasons) conditions.

Evaluation of VNTR typing for the identification of Mycobacterium ulcerans in environmental samples from Victoria, Australia.

Reliable molecular detection of Mycobacterium ulcerans in environmental samples is essential to study the ecology and transmission of this important human pathogen. Variable number tandem repeat (VNTR) typing is a valuable method for distinguishing M. ulcerans isolates from different geographic regions and for distinguishing M. ulcerans from other members of the Mycobacterium marinum/M. ulcerans complex, but its application to environmental samples has not yet been evaluated systematically. This study compares the sensitivity and specificity of PCR detection of 13 VNTR loci to determine the best loci for the analysis of environmental samples. This study demonstrates that VNTR typing using selected loci can be a useful addition to established molecular methods for detecting M. ulcerans in the environment and highlights some of the issues encountered when using molecular methods to detect microorganisms in environmental samples. When applied to environmental samples collected from an endemic region in Victoria, Australia, VNTR typing confirmed that the strain of M. ulcerans being detected was indistinguishable from the strain causing disease in humans in that region.

Does water fluoridation affect the prevalence of enamel fluorosis differently among racial and ethnic groups?

OBJECTIVES: There are reports showing higher prevalence of enamel fluorosis among African-American children. This study was conducted to assess whether the effect of water fluoride level on enamel fluorosis is different among different race/ethnicity groups among US school children. METHODS: Data from the National Survey of Oral Health of US School Children 1986-1987 were analyzed to determine the prevalence of enamel fluorosis among 7-17 year-old children. The association between race/ethnicity and enamel fluorosis was examined using logistic regression modeling after controlling for potential confounders age, gender, water fluoridation, other sources of fluoride, and region of residence. RESULTS: The prevalence of very mild to severe enamel fluorosis was 20.8 (95% CI, 15.4, 26.3) and 25.7 (95% CI, 15.0, 36.5) percent among non-Hispanic White and non-Hispanic Black children, respectively. Neither the adjusted odds ratio of 1.3 (0.8, 2.0) for the non-Hispanic Black group nor the interaction effect between non-Hispanic Black and water fluoridation were statistically significant. CONCLUSIONS: Enamel fluorosis was not associated with race/ethnicity. Our analysis suggests that exposure to similar levels of fluoride in the water does not appear to place certain race/ethnic groups at a higher risk for developing enamel fluorosis, and lowering the optimal range of drinking water fluoride to a single value of 0.7 ppm will provide a level of protection against enamel fluorosis that will benefit all race/ethnicity groups.

Reduced Purposeful Head Movements During Community Ambulation Following Unilateral Vestibular Loss.

BACKGROUND: Individuals with unilateral vestibular hypofunction (UVH) alter their movement and reduce mobility to try to stabilize their gaze and avoid symptoms of dizziness and vertigo. OBJECTIVE: To determine if individuals with UVH 6 weeks after surgery demonstrate altered head and trunk kinematics during community ambulation. METHODS: A total of 15 vestibular schwannoma patients with documented postoperative unilateral vestibular loss and 9 healthy controls with symmetrical vestibulo-ocular reflexes participated in this cross-sectional study. Head kinematics (head turn frequency, amplitude, and velocity) and head-trunk coordination during community ambulation were obtained from inertial measurement units for all head movements and within specific amplitudes of head movement. RESULTS: Individuals with UVH made smaller (mean 26° [SD = 3°] vs 32° [SD = 6°]), fewer (mean 133 [SD = 59] vs 221 [SD = 64]), and slower (mean 75°/s [SD = 8°/s] vs 103°/s [SD = 23°/s]) head turns than healthy individuals ( P < .05) but did not demonstrate significantly increased head-trunk coupling (mean 38% [SD = 18%] vs 31% [SD = 11%], P = .22). When small (≤45°) and large (>45°) head turns were considered separately, individuals with UVH demonstrated increased head-trunk coupling compared with healthy individuals for large head turns (mean 54% [SD = 23%] vs 33% [SD = 10%], P = .005). CONCLUSIONS: This study demonstrated that although walking at an adequate speed, individuals with UVH made fewer, smaller, and slower head movements symmetrically in both directions compared with healthy individuals and did not decouple their head movement relative to their trunk when required to make larger purposeful head turns during community ambulation.

Ubiquity of polystyrene digestion and biodegradation within yellow mealworms, larvae of Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae).

Academics researchers and "citizen scientists" from 22 countries confirmed that yellow mealworms, the larvae of Tenebrio molitor Linnaeus, can survive by eating polystyrene (PS) foam. More detailed assessments of this capability for mealworms were carried out by12 sources: five from the USA, six from China, and one from Northern Ireland. All of these mealworms digested PS foam. PS mass decreased and depolymerization was observed, with appearance of lower molecular weight residuals and functional groups indicative of oxidative transformations in extracts from the frass (insect excrement). An addition of gentamycin (30 mg g-1), a bactericidal antibiotic, inhibited depolymerization, implicating the gut microbiome in the biodegradation process. Microbial community analyses demonstrated significant taxonomic shifts for mealworms fed diets of PS plus bran and PS alone. The results indicate that mealworms from diverse locations eat and metabolize PS and support the hypothesis that this capacity is independent of the geographic origin of the mealworms, and is likely ubiquitous to members of this species.