3,692 research outputs found

    Diffuse flow environments within basalt- and sediment-based hydrothermal vent ecosystems harbor specialized microbial communities

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    Hydrothermal vents differ both in surface input and subsurface geochemistry. The effects of these differences on their microbial communities are not clear. Here, we investigated both alpha and beta diversity of diffuse flow-associated microbial communities emanating from vents at a basalt-based hydrothermal system along the East Pacific Rise (EPR) and a sediment-based hydrothermal system, Guaymas Basin. Both Bacteria and Archaea were targeted using high throughput 16S rRNA gene pyrosequencing analyses. A unique aspect of this study was the use of a universal set of 16S rRNA gene primers to characterize total and diffuse flow-specific microbial communities from varied deep-sea hydrothermal environments. Both surrounding seawater and diffuse flow water samples contained large numbers of Marine Group I (MGI) Thaumarchaea and Gammaproteobacteria taxa previously observed in deep-sea systems. However, these taxa were geographically distinct and segregated according to type of spreading center. Diffuse flow microbial community profiles were highly differentiated. In particular, EPR dominant diffuse flow taxa were most closely associated with chemolithoautotrophs, and off axis water was dominated by heterotrophic-related taxa, whereas the opposite was true for Guaymas Basin. The diversity and richness of diffuse flow-specific microbial communities were strongly correlated to the relative abundance of Epsilonproteobacteria, proximity to macrofauna, and hydrothermal system type. Archaeal diversity was higher than or equivalent to bacterial diversity in about one third of the samples. Most diffuse flow-specific communities were dominated by OTUs associated with Epsilonproteobacteria, but many of the Guaymas Basin diffuse flow samples were dominated by either OTUs within the Planctomycetes or hyperthermophilic Archaea. This study emphasizes the unique microbial communities associated with geochemically and geographically distinct hydrothermal diffuse flow environments

    Substrate Stiffness Controls Osteoblastic and Chondrocytic Differentiation of Mesenchymal Stem Cells without Exogenous Stimuli

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    Stem cell fate has been linked to the mechanical properties of their underlying substrate, affecting mechanoreceptors and ultimately leading to downstream biological response. Studies have used polymers to mimic the stiffness of extracellular matrix as well as of individual tissues and shown mesenchymal stem cells (MSCs) could be directed along specific lineages. In this study, we examined the role of stiffness in MSC differentiation to two closely related cell phenotypes: osteoblast and chondrocyte. We prepared four methyl acrylate/methyl methacrylate (MA/MMA) polymer surfaces with elastic moduli ranging from 0.1 MPa to 310 MPa by altering monomer concentration. MSCs were cultured in media without exogenous growth factors and their biological responses were compared to committed chondrocytes and osteoblasts. Both chondrogenic and osteogenic markers were elevated when MSCs were grown on substrates with stiffnesschondrocytes, MSCs on lower stiffness substrates showed elevated expression of ACAN, SOX9, and COL2 and proteoglycan content; COMP was elevated in MSCs but reduced in chondrocytes. Substrate stiffness altered levels of RUNX2 mRNA, alkaline phosphatase specific activity, osteocalcin, and osteoprotegerin in osteoblasts, decreasing levels on the least stiff substrate. Expression of integrin subunits α1, α2, α5, αv, β1, and β3 changed in a stiffness- and cell type-dependent manner. Silencing of integrin subunit beta 1 (ITGB1) in MSCs abolished both osteoblastic and chondrogenic differentiation in response to substrate stiffness. Our results suggest that substrate stiffness is an important mediator of osteoblastic and chondrogenic differentiation, and integrin β1 plays a pivotal role in this process

    Structuring Joint Action Routines: A Strategy for Facilitating Communication and Language Development in the Classroom

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    The study of early child language has produced a wealth of new data and con­comitant theories over the past decade, and these new perspectives offer important im­plications to those of us engaged in clinical practice. We have noted elsewhere that this current literature on early child language has specific implications for designing ap­propriate targets, contexts, and procedures for language therapy (McLean and Snyder-­McLean, 1978; McLean, Snyder-McLean, and Sack, 1983). In this article, we will con­centrate on these two latter areas: contexts and procedures for language intervention and, more specifically, on the combination of these elements in the form of structured joint action routines

    Event-Free Survival in Adults With Heart Failure who Engage in Self-Care Management

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    Background Self-care management in heart failure (HF) involves decision-making to evaluate, and actions to ameliorate symptoms when they occur. This study sought to compare the risks of all-cause mortality, hospitalization, or emergency-room admission among HF patients who practice above-average self-care management, those who practice below-average self-care management, and those who are symptom-free. Methods A secondary analysis was conducted of data collected on 195 HF patients. A Cox proportional hazards model was used to examine the association between self-care management and event risk. Results The sample consisted of older (mean ± standard deviation = 61.3 ± 11 years), predominantly male (64.6%) adults, with an ejection fraction of 34.7% ± 15.3%; 60.1% fell within New York Heart Association class III or IV HF. During an average follow-up of 364 ± 288 days, 4 deaths, 82 hospitalizations, and 5 emergency-room visits occurred as first events. Controlling for 15 common confounders, those who engaged in above-average self-care management (hazard ratio, .44; 95% confidence interval, .22 to .88; P \u3c .05) and those who were symptom-free (hazard ratio, 0.48; 95% confidence interval, .24 to .97; P \u3c .05) ran a lower risk of an event during follow-up than those engaged in below-average self-care management. Conclusion Symptomatic HF patients who practice above-average self-care management have an event-free survival benefit similar to that of symptom-free HF patients

    Development and initial testing of the self‐care of chronic illness inventory

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    Aim The aim was to develop and psychometrically test the self‐care of chronic illness Inventory, a generic measure of self‐care. Background Existing measures of self‐care are disease‐specific or behaviour‐specific; no generic measure of self‐care exists. Design Cross‐sectional survey. Methods We developed a 20‐item self‐report instrument based on the Middle Range Theory of Self‐Care of Chronic Illness, with three separate scales measuring Self‐Care Maintenance, Self‐Care Monitoring, and Self‐Care Management. Each of the three scales is scored separately and standardized 0–100 with higher scores indicating better self‐care. After demonstrating content validity, psychometric testing was conducted in a convenience sample of 407 adults (enrolled from inpatient and outpatient settings at five sites in the United States and ResearchMatch.org). Dimensionality testing with confirmatory factor analysis preceded reliability testing. Results The Self‐Care Maintenance scale (eight items, two dimensions: illness‐related and health‐promoting behaviour) fit well when tested with a two‐factor confirmatory model. The Self‐Care Monitoring scale (five items, single factor) fitted well. The Self‐Care Management scale (seven items, two factors: autonomous and consulting behaviour), when tested with a two‐factor confirmatory model, fitted adequately. A simultaneous confirmatory factor analysis on the combined set of items supported the more general model. Conclusion The self‐care of chronic illness inventory is adequate in reliability and validity. We suggest further testing in diverse populations of patients with chronic illnesses

    Role of Self-Care in the Patient with Heart Failure

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    Optimal outcomes and quality of life for patients with heart failure depend on engagement in effective self-care activities. Self-care is a complex set of activities and most clinicians are not adequately prepared to assist their patients to engage in effective self-care. In this paper, we provide an overview of self-care that includes definitions, the importance of self-care to outcomes, the physiologic basis for better outcomes with good self-care, cultural perspectives of self-care, and recommendations for the improvement of self-care. Promotion of effective self-care by all clinicians could substantially reduce the economic and personal burden of repeated rehospitalizations among patients with heart failure

    Characterization of Biochars Produced From Peanut Hulls and Pine Wood with Different Pyrolysis Conditions

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    Background Application of modern biomass pyrolysis methods for production of biofuels and biochar is potentially a significant approach to enable global carbon capture and sequestration. To realize this potential, it is essential to develop methods that produce biochar with the characteristics needed for effective soil amendment. Methods Biochar materials were produced from peanut hulls and pine wood with different pyrolysis conditions, then characterized by cation exchange (CEC) capacity assays, nitrogen adsorption–desorption isotherm measurements, micro/nanostructural imaging, infrared spectra and elemental analyses. Results Under a standard assay condition of pH 8.5, the CEC values of the peanut hull-derived biochar materials, ranging from 6.22 to 66.56 cmol kg−1, are significantly higher than those of the southern yellow pine-derived biochar, which are near zero or negative. The biochar produced from peanut hulls with a steam activation process yielded the highest CEC value of 66.56 cmol kg−1, which is about 5 times higher than the cation exchange capacity (12.51 cmol kg−1) of a reference soil sample. Notably, biochar produced from peanut hulls with batch barrel retort pyrolysis also has a much higher CEC value (60.12 cmol kg−1) than that (12.45 cmol kg−1) from Eprida’s H2-producing continuous steam injection process. The CEC values were shown to correlate well with the ratios of oxygen atoms to carbon atoms (O:C ratios) in the biochar materials. The higher O:C ratio in a biochar material may indicate the presence of more hydroxyl, carboxylate, and carbonyl groups that contribute to a higher CEC value for the biochar product. In addition, the increase in surface area can also play a role in increasing the CEC value of biochar, as in the case of the steam activation char. Conclusion Comparison of characterization results indicated that CEC value is determined not only by the type of the source biomass materials but also by the pyrolysis conditions. Biochar with the desirable characteristics of extremely high surface area (700 m2/g) and cation exchange capacity (\u3e 60 cmol kg) was created through steam activation

    Biomarkers of Myocardial Stress and Systemic Inflammation in Patients Who Engage in Heart Failure Self-Care Management

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    Background: Self-care is believed to improve heart failure (HF) outcomes, but the mechanisms by which such improvement occurs remain unclear. Methods: We completed a secondary analysis of cross-sectional data collected on adults with symptomatic HF to test our hypothesis that effective self-care is associated with less myocardial stress and systemic inflammation. Multivariate logistic regression modeling was used to determine if better HF self-care reduced the odds of having serum levels of amino-terminal pro-B-type natriuretic peptide and soluble tumor necrosis factor α receptor type 1 at or greater than the sample median. Heart failure self-care was measured using the Self-care of Heart Failure Index. Results: The sample (n = 168) was predominantly male (65.5%), and most (50.6%) had New York Heart Association III HF (mean left ventricular ejection fraction, 34.9% [SD, 14.0%]); mean age was 58.8 (SD, 11.5) years. Self-care management was an independent factor in the model (block χ2 = 14.74; P = .005) after controlling for pertinent confounders (model χ2 = 52.15; P \u3c .001). Each 1-point increase in self-care management score (range, 15-100) was associated with a 12.7% reduction in the odds of having levels of both biomarkers at or greater than the sample median (adjusted odds ratio, 0.873; 95% confidence interval, 0.77-0.99; P = .03). Conclusion: Better self-care management was associated with reduced odds of myocardial stress and systemic inflammation over and above pharmacological therapy and other common confounding factors. Teaching HF patients early symptom recognition and self-care of symptoms may decrease myocardial stress and systemic inflammation

    Small Drusen and Age-Related Macular Degeneration: The Beaver Dam Eye Study

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    We tested the hypothesis that large areas of small hard drusen (diameter \u3c63 μm) and intermediate drusen (diameter 63-124 μm) are associated with the incidence of age-related macular degeneration (AMD). Eyes of 3344 older adults with at least 2 consecutive visits spaced 5 years apart over a 20-year period were included. A 6-level severity scale including no drusen, 4 levels of increasing area (from minimal (\u3c2596 μm2) to large (\u3e9086 μm2)) of only small hard drusen, and intermediate drusen was used. The 5-year incidence of AMD was 3% in eyes at the start of the interval with no, minimal, small, and moderate areas of only small drusen and 5% and 25% for eyes with large area of only small drusen and intermediate drusen, respectively. Compared to eyes with a moderate area of small drusen, the odds ratio (OR) of developing AMD in eyes with a large area of only small drusen was 1.8 (p \u3c 0.001). Compared to eyes with large area of only small drusen, eyes with intermediate drusen had an OR of 5.5 (p \u3c 0.001) of developing AMD. Our results are consistent with our hypothesis that large areas of only small drusen are associated with the incidence of AMD
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