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1.
Pediatr Res ; 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38867029

RESUMEN

BACKGROUND: Sleep problems are reported for up to 80% of autistic individuals. We examined whether parsimonious sets of items derived from the Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R) and the Brief Infant Sleep Questionnaire (BISQ) are superior to the standard M-CHAT-R in predicting subsequent autism spectrum disorder (ASD) diagnoses. METHODS: Participants from 11 Environmental influences on Child Health Outcomes (ECHO) cohorts were included. We performed logistic LASSO regression models with 10-fold cross-validation to identify whether a combination of items derived from the M-CHAT-R and BISQ are superior to the standard M-CHAT-R in predicting ASD diagnoses. RESULTS: The final sample comprised 1552 children. The standard M-CHAT-R had a sensitivity of 44% (95% CI: 34, 55), specificity of 92% (95% CI: 91, 94), and AUROC of 0.726 (95% CI: 0.663, 0.790). A higher proportion of children with ASD had difficulty falling asleep or resisted bedtime during infancy/toddlerhood. However, LASSO models revealed parental reports of sleep problems did not improve the accuracy of the M-CHAT-R in predicting ASD diagnosis. CONCLUSION: While children with ASD had higher rates of sleep problems during infancy/toddlerhood, there was no improvement in ASD developmental screening through the incorporation of parent-report sleep metrics. IMPACT: Parental-reported sleep problems are common in autism spectrum disorder (ASD). We investigated whether the inclusion of parental-reports of infant/toddler sleep patterns enhanced the effectiveness of developmental screening for autism. We reported higher rates of difficulty falling asleep and resisting bedtime during infancy and toddlerhood among children later diagnosed with ASD; however, we did not find an improvement in ASD developmental screening through the incorporation of parent-report sleep metrics. In our sample, the standard M-CHAT-R had a sensitivity of 39% among children of mothers with government insurance compared with a sensitivity of 53% among children of mothers with employer-based insurance.

2.
Environ Sci Technol ; 58(26): 11400-11410, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38889135

RESUMEN

Phosphorus (P) limitation often constrains biological processes in Arctic tundra ecosystems. Although adsorption to soil minerals may limit P bioavailability and export from soils into aquatic systems, the contribution of mineral phases to P retention in Arctic tundra is poorly understood. Our objective was to use X-ray absorption spectroscopy to characterize P speciation and associations with soil minerals along hillslope toposequences and in undisturbed and disturbed low-lying wet sedge tundra on the North Slope, AK. Biogenic mats comprised of short-range ordered iron (Fe) oxyhydroxides were prevalent in undisturbed wet sedge meadows. Upland soils and pond sediments impacted by gravel mining or thermokarst lacked biogenic Fe mats and were comparatively iron poor. Phosphorus was primarily contained in organic compounds in hillslope soils but associated with Fe(III) oxyhydroxides in undisturbed wet sedge meadows and calcium (Ca) in disturbed pond sediments. We infer that phosphate mobilized through organic decomposition binds to Fe(III) oxyhydroxides in wet sedge, but these associations are disrupted by physical disturbance that removes Fe mats. Increasing disturbances of the Arctic tundra may continue to alter the mineralogical composition of soils at terrestrial-aquatic interfaces and binding mechanisms that could inhibit or promote transport of bioavailable P from soils to aquatic ecosystems.


Asunto(s)
Hierro , Fósforo , Tundra , Fósforo/química , Regiones Árticas , Hierro/química , Ecosistema , Espectroscopía de Absorción de Rayos X , Suelo/química , Sedimentos Geológicos/química
3.
Environ Microbiol ; 25(11): 2516-2533, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37596970

RESUMEN

Seasonal changes in light and physicochemical conditions have strong impacts on cyanobacteria, but how they affect community structure, metabolism, and biogeochemistry of cyanobacterial mats remains unclear. Light may be particularly influential for cyanobacterial mats exposed to sulphide by altering the balance of oxygenic photosynthesis and sulphide-driven anoxygenic photosynthesis. We studied temporal shifts in irradiance, water chemistry, and community structure and function of microbial mats in the Middle Island Sinkhole (MIS), where anoxic and sulphate-rich groundwater provides habitat for cyanobacteria that conduct both oxygenic and anoxygenic photosynthesis. Seasonal changes in light and groundwater chemistry were accompanied by shifts in bacterial community composition, with a succession of dominant cyanobacteria from Phormidium to Planktothrix, and an increase in diatoms, sulphur-oxidizing bacteria, and sulphate-reducing bacteria from summer to autumn. Differential abundance of cyanobacterial light-harvesting proteins likely reflects a physiological response of cyanobacteria to light level. Beggiatoa sulphur oxidation proteins were more abundant in autumn. Correlated abundances of taxa through time suggest interactions between sulphur oxidizers and sulphate reducers, sulphate reducers and heterotrophs, and cyanobacteria and heterotrophs. These results support the conclusion that seasonal change, including light availability, has a strong influence on community composition and biogeochemical cycling of sulphur and O2 in cyanobacterial mats.


Asunto(s)
Cianobacterias , Proteoma , Proteoma/genética , Proteoma/metabolismo , Estaciones del Año , Cianobacterias/metabolismo , Sulfuros/metabolismo , Oxígeno/metabolismo , Azufre/metabolismo , Sulfatos/metabolismo
4.
Environ Sci Technol ; 56(7): 4620-4631, 2022 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-35290040

RESUMEN

In permafrost peatlands, up to 20% of total organic carbon (OC) is bound to reactive iron (Fe) minerals in the active layer overlying intact permafrost, potentially protecting OC from microbial degradation and transformation into greenhouse gases (GHG) such as CO2 and CH4. During the summer, shifts in runoff and soil moisture influence redox conditions and therefore the balance of Fe oxidation and reduction. Whether reactive iron minerals could act as a stable sink for carbon or whether they are continuously dissolved and reprecipitated during redox shifts remains unknown. We deployed bags of synthetic ferrihydrite (FH)-coated sand in the active layer along a permafrost thaw gradient in Stordalen mire (Abisko, Sweden) over the summer (June to September) to capture changes in redox conditions and quantify the formation and dissolution of reactive Fe(III) (oxyhydr)oxides. We found that the bags accumulated Fe(III) under constant oxic conditions in areas overlying intact permafrost over the full summer season. In contrast, in fully thawed areas, conditions were continuously anoxic, and by late summer, 50.4 ± 12.8% of the original Fe(III) (oxyhydr)oxides were lost via dissolution. Periodic redox shifts (from 0 to +300 mV) were observed over the summer season in the partially thawed areas. This resulted in the dissolution and loss of 47.2 ± 20.3% of initial Fe(III) (oxyhydr)oxides when conditions are wetter and more reduced, and new formation of Fe(III) minerals (33.7 ± 8.6% gain in comparison to initial Fe) in the late summer under more dry and oxic conditions, which also led to the sequestration of Fe-bound organic carbon. Our data suggest that there is seasonal turnover of iron minerals in partially thawed permafrost peatlands, but that a fraction of the Fe pool remains stable even under continuously anoxic conditions.


Asunto(s)
Hielos Perennes , Compuestos Férricos/metabolismo , Hierro/metabolismo , Oxidación-Reducción , Estaciones del Año , Suelo
5.
Sci Total Environ ; 915: 170089, 2024 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-38224896

RESUMEN

Wetlands cycle carbon by being net sinks for carbon dioxide (CO2) and net sources of methane (CH4). Daily and seasonal temporal patterns, dissolved oxygen (DO) availability, inundation status (flooded or dry/partially flooded), water depth, and vegetation can affect the magnitude of carbon uptake or emissions, but the extent and interactive effects of these variables on carbon gas fluxes are poorly understood. We characterized the linkages between carbon fluxes and these environmental and temporal drivers at the Old Woman Creek National Estuarine Research Reserve (OWC), OH. We measured diurnal gas flux patterns in an upstream side channel (called the cove) using chamber measurements at six sites (three vegetated and three non-vegetated). We sampled hourly from 7 AM to 7 PM and monthly from July to October 2022. DO concentrations and water levels were measured monthly. Water inundation status had the most influential effect on carbon fluxes with flooded conditions supporting higher CH4 fluxes (0.39 µmol CH4 m-2 s-1; -1.23 µmol CO2 m-2 s-1) and drier conditions supporting higher CO2 fluxes (0.03 µmol CH4 m-2 s-1; 0.86 µmol CO2 m-2 s-1). When flooded, the wetland was a net CO2 sink; however, it became a source for both CH4 and CO2 when water levels were low. We compared chamber-based gas fluxes from the cove in flooded (July) and dry (August) months to fluxes measured with an eddy covariance tower whose footprint covers flooded portions of the wetland. The diurnal pattern of carbon fluxes at the tower did not vary with changing water levels but remained a CO2 sink and a CH4 source even when the cove where we performed the chamber measurements dried out. These results emphasize the role of inundation status on wetland carbon cycling and highlight the importance of fluctuating hydrologic patterns, especially hydrologic drawdowns, under changing climatic conditions.

6.
Artículo en Inglés | MEDLINE | ID: mdl-36471743

RESUMEN

Background: The COVID-19 pandemic has caused significant stress and disruption for young people, likely leading to alterations in their mental health and neurodevelopment. In this context, it is not clear whether youth who lived through the pandemic and its shutdowns are comparable psychobiologically to their age- and sex-matched peers assessed before the pandemic. This question is particularly important for researchers who are analyzing longitudinal data that span the pandemic. Methods: In this study we compared carefully matched youth assessed before the pandemic (n=81) and after the pandemic-related shutdowns ended (n=82). Results: We found that youth assessed after the pandemic shutdowns had more severe internalizing mental health problems, reduced cortical thickness, larger hippocampal and amygdala volume, and more advanced brain age. Conclusions: Thus, not only does the COVID-19 pandemic appear to have led to poorer mental health and accelerated brain aging in adolescents, but it also poses significant challenges to researchers analyzing data from longitudinal studies of normative development that were interrupted by the pandemic.

7.
Geobiology ; 20(1): 60-78, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34331395

RESUMEN

The sedimentary pyrite sulfur isotope (δ34 S) record is an archive of ancient microbial sulfur cycling and environmental conditions. Interpretations of pyrite δ34 S signatures in sediments deposited in microbial mat ecosystems are based on studies of modern microbial mat porewater sulfide δ34 S geochemistry. Pyrite δ34 S values often capture δ34 S signatures of porewater sulfide at the location of pyrite formation. However, microbial mats are dynamic environments in which biogeochemical cycling shifts vertically on diurnal cycles. Therefore, there is a need to study how the location of pyrite formation impacts pyrite δ34 S patterns in these dynamic systems. Here, we present diurnal porewater sulfide δ34 S trends and δ34 S values of pyrite and iron monosulfides from Middle Island Sinkhole, Lake Huron. The sediment-water interface of this sinkhole hosts a low-oxygen cyanobacterial mat ecosystem, which serves as a useful location to explore preservation of sedimentary pyrite δ34 S signatures in early Earth environments. Porewater sulfide δ34 S values vary by up to ~25‰ throughout the day due to light-driven changes in surface microbial community activity that propagate downwards, affecting porewater geochemistry as deep as 7.5 cm in the sediment. Progressive consumption of the sulfate reservoir drives δ34 S variability, instead of variations in average cell-specific sulfate reduction rates and/or sulfide oxidation at different depths in the sediment. The δ34 S values of pyrite are similar to porewater sulfide δ34 S values near the mat surface. We suggest that oxidative sulfur cycling and other microbial activity promote pyrite formation in and immediately adjacent to the microbial mat and that iron geochemistry limits further pyrite formation with depth in the sediment. These results imply that primary δ34 S signatures of pyrite deposited in organic-rich, iron-poor microbial mat environments capture information about microbial sulfur cycling and environmental conditions at the mat surface and are only minimally affected by deeper sedimentary processes during early diagenesis.


Asunto(s)
Cianobacterias , Microbiota , Sedimentos Geológicos/química , Hierro/química , Oxígeno , Sulfuros/química , Isótopos de Azufre/análisis
8.
Biofouling ; 27(5): 505-18, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21623481

RESUMEN

Adsorption of bovine serum albumin (BSA) and fibrinogen (Fg) was measured on six distinct bare and dextran- and hyaluronate-modified silicon surfaces created using two dextran grafting densities and three hyaluronic acid (HA) sodium salts derived from human umbilical cord, rooster comb and Streptococcus zooepidemicus. Film thickness and surface morphology depended on the HA molecular weight and concentration. BSA coverage was enhanced on surfaces in competitive adsorption of BSA:Fg mixtures. Dextranization differentially reduced protein adsorption onto surfaces based on oxidation state. Hyaluronization was demonstrated to provide the greatest resistance to protein coverage, equivalent to that of the most resistant dextranized surface. Resistance to protein adsorption was independent of the type of HA utilized. With changing bulk protein concentration from 20 to 40 µg ml(-1) for each species, Fg coverage on silicon increased by 4x, whereas both BSA and Fg adsorption on dextran and HA were far less dependent on protein bulk concentration.


Asunto(s)
Cresta y Barbas/metabolismo , Dextranos/química , Fibrinógeno/química , Ácido Hialurónico/química , Albúmina Sérica Bovina/química , Streptococcus equi/metabolismo , Cordón Umbilical/metabolismo , Adsorción , Animales , Materiales Biocompatibles/química , Bovinos , Pollos , Humanos , Oxidación-Reducción , Silicio/química , Propiedades de Superficie
9.
Geobiology ; 18(4): 462-475, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32181592

RESUMEN

Constraints on Precambrian ocean chemistry are dependent upon sediment geochemistry. However, diagenesis and metamorphism can destroy primary biosignatures, making it difficult to consider biology when interpreting geochemical data. Modern analogues for ancient ecosystems can be useful tools for identifying how sediment geochemistry records an active biosphere. The Middle Island Sinkhole (MIS) in Lake Huron is an analogue for shallow Proterozoic waters due to its low oxygen water chemistry and microbial communities that exhibit diverse metabolic functions at the sediment-water interface. This study uses sediment trace metal contents and microbial abundances in MIS sediments and an oxygenated Lake Huron control site (LH) to infer mechanisms for trace metal burial. The adsorption of trace metals to Mn-oxyhydroxides is a critical burial pathway for metals in oxic LH sediments, but not for the MIS mat and sediments, consistent with conventional understanding of Mn cycling. Micronutrient trace metals (e.g., Zn) are associated with organic matter regardless of oxygen and sulfide availability. Although U and V are conventionally considered to be organically complexed in suboxic and anoxic conditions, U and organic covary in oxic LH sediments, and Mn-oxyhydroxide cycling dominates V deposition in the anoxic MIS sediments. Significant correlations between Mo and organic matter across all redox regimes have major implications for our interpretations of Mo isotope systematics in the geologic record. Finally, while microbial groups vary between the sampling locales (e.g., the cyanobacteria in the MIS microbial mat are not present in LH sediments), LH and MIS ultimately have similar relationships between microbial assemblages and metal burial, making it difficult to link trace metal burial to microbial metabolisms. Together, these results indicate that bulk sediment trace metal composition does not capture microbiological processes; more robust trace metal geochemistry such as isotopes and speciation may be critical for understanding the intersections between microbiology and sediment geochemistry.


Asunto(s)
Microbiota , Sedimentos Geológicos , Metales , Océanos y Mares , Oxidación-Reducción
10.
Environ Sci Process Impacts ; 22(7): 1475-1490, 2020 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-32475995

RESUMEN

Phosphorus (P) is a limiting or co-limiting nutrient to plants and microorganisms in diverse ecosystems that include the arctic tundra. Certain soil minerals can adsorb or co-precipitate with phosphate, and this mineral-bound P provides a potentially large P reservoir in soils. Iron (Fe) oxyhydroxides have a high capacity to adsorb phosphate; however, the ability of Fe oxyhydroxides to adsorb phosphate and limit P bioavailability in organic tundra soils is not known. Here, we examined the depth distribution of soil Fe and P species in the active layer (<30 cm) of low-centered and high-centered ice-wedge polygons at the Barrow Environmental Observatory on the Alaska North Slope. Soil reservoirs of Fe and P in bulk horizons and in narrower depth increments were characterized using sequential chemical extractions and synchrotron-based X-ray absorption spectroscopy (XAS). Organic horizons across all polygon features (e.g., trough, ridge, and center) were enriched in extractable Fe and P relative to mineral horizons. Soil Fe was dominated by organic-bound Fe and short-range ordered Fe oxyhydroxides, while soil P was primarily associated with oxides and organic matter in organic horizons but apatite and/or calcareous minerals in mineral horizons. Iron oxyhydroxides and Fe-bound inorganic P (Pi) were most enriched at the soil surface and decreased gradually with depth, and Fe-bound Pi was >4× greater than water-soluble Pi. These results demonstrate that Fe-bound Pi is a large and ecologically important reservoir of phosphate. We contend that Fe oxyhydroxides and other minerals may regulate Pi solubility under fluctuating redox conditions in organic surface soils on the arctic tundra.


Asunto(s)
Hierro , Fosfatos , Suelo , Alaska , Ecosistema , Hielo , Suelo/química , Tundra
12.
Environ Toxicol Chem ; 34(3): 467-79, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25376510

RESUMEN

Potentially toxic levels of 3 naturally occurring chemical stressors (dissolved sulfide, ammonia, and iron) can appear in freshwater sediments, although their roles in shaping ecosystem structure (i.e., plant and animal communities) and function (e.g., biologically mediated elemental cycles) have received little study. The present critical review discusses the prevalence and ecological effects of potentially toxic concentrations of sulfide, ammonia, and iron in uncontaminated freshwater sediments, including a review of the literature as well as a case study presenting previously unpublished data on sediment porewaters from a diverse set of shallow (<2 m) freshwater ecosystems in southwest Michigan, USA. Measured concentrations are compared with surface water quality criteria established by the US Environmental Protection Agency (USEPA) and with acute and chronic toxic thresholds in the published literature, where available. Based on USEPA criteria for aquatic life for these 3 stressors, the benthic environment of almost every freshwater ecosystem sampled was theoretically stressful to some component of aquatic life in some area or at some time (i.e., in at least 1 sample), and 54% of samples exceeded more than 1 criterion simultaneously. Organismal tolerances to chemical stressors vary, so the observed concentrations are likely shaping benthic animal communities and influencing rates of ecosystem processes. Consideration of the role of natural chemical stressors is important in shaping freshwater benthic environments and in developing bioassessments, restoration goals, and remediation plans. Environ Toxicol Chem 2015;34:467-479. © 2014 SETAC.


Asunto(s)
Amoníaco/análisis , Agua Dulce/química , Sedimentos Geológicos/química , Hierro/análisis , Sulfuros/análisis , Contaminantes Químicos del Agua/análisis
13.
Am J Manag Care ; 20(5): e166-74, 2014 05.
Artículo en Inglés | MEDLINE | ID: mdl-25326931

RESUMEN

OBJECTIVES: To demonstrate the feasibility and utility of using administrative claims data from commercial health plans to establish a high-risk indicator in a statewide immunization registry for enrollees with chronic conditions. STUDY DESIGN: Retrospective cohort analysis. METHODS: Administrative data were used to identify children with 1 or more chronic conditions enrolled in 2 commercial health plans during the 2008-2009 and 2009-2010 influenza seasons and matched with a statewide immunization registry. The proportion of cases that successfully matched and historical health services utilization, including influenza vaccinations and missed opportunities, were assessed. RESULTS: A total of 93% of children with chronic conditions identified through administrative claims were successfully matched with the statewide registry. Less than one-third of children received the seasonal influenza vaccine in either the 2008-2009 (29%) or 2009-2010 (32%) seasons; 30% of children received the H1N1 vaccination in 2009-2010. Most children in the 2008-2009 (63%) and 2009-2010 (63%) seasons had at least 1 missed opportunity for seasonal influenza vaccination. Younger children had the highest percentage of missed opportunities while adolescents had the lowest rate of missed opportunities for vaccination. Conclusions It is feasible to identify children with chronic conditions using administrative data and to link them with a statewide immunization registry. Low influenza vaccination rates and high occurrences of missed opportunities among children with chronic conditions suggest the utility of integrating administrative claims data with statewide registries to support various outreach mechanisms, including physician-focused and parent-targeted reminder/recall, based on target age to improve vaccination rates.


Asunto(s)
Enfermedad Crónica/epidemiología , Inmunización/estadística & datos numéricos , Revisión de Utilización de Seguros , Adolescente , Niño , Preescolar , Estudios de Factibilidad , Femenino , Humanos , Lactante , Subtipo H1N1 del Virus de la Influenza A , Vacunas contra la Influenza/uso terapéutico , Gripe Humana/epidemiología , Masculino , Michigan/epidemiología , Sistema de Registros
14.
Am J Prev Med ; 47(1): 1-8, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24750973

RESUMEN

BACKGROUND: Although previous studies have found reminder/recall to be effective in increasing immunization rates, little guidance exists regarding the specific ages at which it is optimal to send reminder/recall notices. PURPOSE: To assess the relative effectiveness of centralized reminder/recall strategies targeting age-specific vaccination milestones among children in urban areas during June 2008-June 2009. METHODS: Three reminder/recall strategies used capabilities of the Michigan Care Improvement Registry (MCIR), a statewide immunization information system: a 7-month recall strategy, a 12-month reminder strategy, and a 19-month recall strategy. Eligible children were randomized to notification (intervention) or no notification groups (control). Primary study outcomes included MCIR-recorded immunization activity (administration of ≥1 new dose, entry of ≥1 historic dose, entry of immunization waiver) within 60 days following each notification cycle. RESULTS: A total of 10,175 children were included: 2,072 for the 7-month recall, 3,502 for the 12-month reminder, and 4,601 for the 19-month recall. Immunization activity was similar between notification versus no notification groups at both 7 and 12 months. Significantly more 19-month-old children in the recall group (26%) had immunization activity compared to their counterparts who did not receive a recall notification (19%). CONCLUSIONS: Although recall notifications can positively affect immunization activity, the effect may vary by targeted age group. Many 7- and 12-month-olds had immunization activity following reminder/recall; however, levels of activity were similar irrespective of notification, suggesting that these groups were likely to receive medical care or immunization services without prompting.


Asunto(s)
Programas de Inmunización/métodos , Inmunización/estadística & datos numéricos , Sistemas Recordatorios , Vacunación/estadística & datos numéricos , Factores de Edad , Humanos , Lactante , Michigan , Sistema de Registros , Factores de Tiempo , Población Urbana
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