1,209 research outputs found

    Microbial Communities at a Shallow Submarine Hydrothermal Vent in the Aegean Sea (Milos, Greece)

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    Effects of Gait Speed of Femoroacetabular Joint Forces

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    Alterations in hip joint loading have been associated with diseases such as arthritis and osteoporosis. Understanding the relationship between gait speed and hip joint loading in healthy hips may illuminate changes in gait mechanics as walking speed deviates from preferred. The purpose of this study was to quantify hip joint loading during the gait cycle and identify differences with varying speed using musculo skeletal modeling. Ten, healthy, physically active individuals performed walking trials at their preferred speed, 10% faster, and 10% slower. Kinematic, kinetic, and electromyographic data were collected and used to estimate hip joint force via a musculoskeletal model. Vertical ground reaction forces, hip joint force planar components, and the resultant hip joint force were compared between speeds. There were significant increases in vertical ground reaction forces and hip joint forces as walking speed increased. Furthermore, the musculoskeletal modeling approach employed yielded hip joint forces that were comparable to previous simulation studies and in vivo measurements and was able to detect changes in hip loading due to small deviations in gait speed. Applying this approach to pathological and aging populations could identify specific areas within the gait cycle where force discrepancies may occur which could help focus management of care

    Genus-Specific Carbon Fixation Activity Measurements Reveal Distinct Responses to Oxygen among Hydrothermal Vent Campylobacteria

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    Molecular surveys of low temperature deep-sea hydrothermal vent fluids have shown that Campylobacteria (previously Epsilonproteobacteria) often dominate the microbial community and that three genera, Arcobacter, Sulfurimonas, and Sulfurovum, frequently coexist. In this study, we used replicated radiocarbon incubations of deep-sea hydrothermal fluids to investigate activity of each genus under three experimental conditions. To quantify genus-specific radiocarbon incorporation, we used newly designed oligonucleotide probes for Arcobacter, Sulfurimonas, and Sulfurovum to quantify their activity using catalyzed-reporter deposition fluorescence in situ hybridization (CARD-FISH) combined with fluorescence-activated cell sorting. All three genera actively fixed CO2 in short-term (similar to 20 h) incubations, but responded differently to the additions of nitrate and oxygen. Oxygen additions had the largest effect on community composition, and caused a pronounced shift in community composition at the amplicon sequence variant (ASV) level after only 20 h of incubation. The effect of oxygen on carbon fixation rates appeared to depend on the initial starting community. The presented results support the hypothesis that these chemoautotrophic genera possess functionally redundant core metabolic capabilities, but also reveal finer-scale differences in growth likely reflecting adaptation of physiologically-distinct phylotypes to varying oxygen concentrations in situ. Overall, our study provides new insights into how oxygen controls community composition and total chemoautotrophic activity, and underscores how quickly deep-sea vent microbial communities respond to disturbances. IMPORTANCE Sulfidic environments worldwide are often dominated by sulfur-oxidizing, carbon-fixing Campylobacteria. Environmental factors associated with this group's dominance are now understood, but far less is known about the ecology and physiology of members of subgroups of chemoautotrophic Campylobacteria. In this study, we used a novel method to differentiate the genus-specific chemoautotrophic activity of three subtypes of Campylobacteria. In combination with evidence from microscopic counts, chemical consumption/production during incubations, and DNA-based measurements, our data show that oxygen concentration affects both community composition and chemoautotrophic function in situ. These results help us better understand factors controlling microbial diversity at deep-sea hydrothermal vents, and provide first-order insights into the ecophysiological differences between these distinct microbial taxa

    A critical evaluation of Kenyon’s Shag (Phalacrocorax [Stictocarbo] kenyoni)

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    We examine the validity of Phalacrocorax [Stictocarbo] kenyoni, which was described by Siegel-Causey (1991) from the Aleutian Islands using midden remains and existing skeletal specimens. We emphasize a morphometric evaluation of the taxon using 224 skeletal specimens of North Pacific cormorants, but we also evaluate the qualitative characters originally used to characterize P. kenyoni. Principal components and discriminant function analyses of 14 skeletal characters failed to support the validity of the species. Similarly, all seven of the character states that Seigel-Causey described as unique to P. kenyoni also were found in P. pelagicus and P. urile. Thus, the three type specimens of P. kenyoni appear to be P. pelagicus. Although we could not confirm the validity of P. kenyoni, our morphometric analyses revealed that P. pelagicus individuals from the central Aleutians are smaller than those from surrounding populations

    Somatic, mood, and vasomotor symptoms at midlife in relation to family structure and household workloads in Sylhet, Bangladesh

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    The purpose of this study was to test whether the frequencies of vasomotor, somatic, and emotional symptoms at midlife were associated with household composition or workloads. Patrilocal family arrangements are common in Bangladesh and, since mothers-in-law hold a position of power vis-à-vis their daughters-in-law, we hypothesized that living with a mother-in-law would increase the likelihood of symptoms at midlife, while living with a daughter-in-law would decrease likelihood of symptoms. We also hypothesised that women with high levels of household workloads would be more likely to report symptoms associated with midlife. Women aged 35-59 living in Sylhet, Bangladesh, (n=157) participated in interviews and anthropometric measures. Symptom frequencies during the past two weeks were collected. Household workloads were computed as minutes spent in housework, caring for dependents, and cooking. Daily values were multiplied by times per week the activity was carried out. Logistic regression was used to evaluate the association between family composition, workloads, and symptoms. Dizzy spells, nervous tension, lack of energy, aches/stiffness in joints, and trouble sleeping were most frequent. Hot flashes were reported by 46% of participants. Women spent more hours caring for dependents than cooking or doing housework. The likelihood of hot flashes increased with time spent in housework and cooking, with daughters in the household, and with chewing betel nut. Daughters-in-law in the household decreased the likelihood of hot flashes. The likelihood of nervous tension increased with peri-menopausal status, stress, and sons in the household, and decreased with more hours spent caring for dependents. The frequency of somatic symptoms and depressed mood exceeded the frequency of hot flashes. Household composition and workloads were more important than menopausal status in explaining variation in symptom frequencies. After controlling for other variables, the presence of mothers-in-law did not increase the likelihood of reporting symptoms at midlife; however, the presence of a daughter-in-law reduced the likelihood of hot flashes, perhaps because of fewer hours spent on housework and cooking

    Human mesenchymal stromal cells from different sources diverge in their expression of cell surface proteins and display distinct differentiation patterns

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    When germ-free cell cultures became a laboratory routine, hopes were high for using this novel technology for treatment of diseases or replacement of cells in patients suffering from injury, inflammation, or cancer or even refreshing cells in the elderly. Today, more than 50 years after the first successful bone marrow transplantation, clinical application of hematopoietic stem cells is a routine procedure, saving the lives of many every day. However, transplanting other than hematopoietic stem and progenitor cells is still limited to a few applications, and it mainly applies to mesenchymal stromal cells (MSCs) isolated from bone marrow. But research progressed and different trials explore the clinical potential of human MSCs isolated from bone marrow but also from other tissues including adipose tissue. Recently, MSCs isolated from bone marrow (bmMSCs) were shown to be a blend of distinct cells and MSCs isolated from different tissues show besides some common features also some significant differences. This includes the expression of distinct antigens on subsets of MSCs, which was utilized recently to define and separate functionally different subsets from bulk MSCs. We therefore briefly discuss differences found in subsets of human bmMSCs and in MSCs isolated from some other sources and touch upon how this could be utilized for cell-based therapies

    Dissolved organic carbon compounds in deep-sea hydrothermal vent fluids from the East Pacific Rise at 9°50′N

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    Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Organic Geochemistry 125 (2018): 41-49, doi:10.1016/j.orggeochem.2018.08.004.Deep-sea hydrothermal vents are unique ecosystems that may release chemically distinct dissolved organic matter to the deep ocean. Here, we describe the composition and concentrations of polar dissolved organic compounds observed in low and high temperature hydrothermal vent fluids at 9°50’N on the East Pacific Rise. The concentration of dissolved organic carbon was 46 μM in the low temperature hydrothermal fluids and 14 μM in the high temperature hydrothermal fluids. In the low temperature vent fluids, quantifiable dissolved organic compounds were dominated by water-soluble vitamins and amino acids. Derivatives of benzoic acid and the organic sulfur compound 2,3-dihydroxypropane-1-sulfonate (DHPS) were also present in low and high temperature hydrothermal fluids. The low temperature vent fluids contain organic compounds that are central to biological processes, suggesting that they are a by-product of biological activity in the subseafloor. These compounds may fuel heterotrophic and other metabolic processes at deep-sea hydrothermal vents and beyond.This project was funded by a grant from WHOI’s Deep Ocean Exploration Institute and WHOI’s Ocean Ridge Initiative (to EBK and SMS) and by NSF OCE-1154320 (to EBK and KL), OCE- 1136727 (to SMS and JSS), and OCE 1131095 (to SMS)

    Religious minority identity associates with stress and psychological health among Muslim and Hindu women in Bangladesh and London

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    This study examined the association of minority religious identification (Hindu or Muslim) with self-reported stress and psychological symptoms among sedentee and immigrant Bangladeshi women. Women, aged 35-59 (n = 531) were drawn from Sylhet, Bangladesh and London, England. Muslim immigrants in London and Hindu sedentees in Sylhet represented minority religious identities. Muslim sedentees in Sylhet and Londoners of European descent represented majority religious identities. In bivariate analyses, minority religious identity was examined in relation to self-reported measures of stress, nervous tension, and depressed mood. Logistic regression was applied to examine the relationship between these variables while adjusting for marital status, parity, daily walking, and perceived financial comfort. In bivariate analyses, religious minorities reported more stress than religious majorities in all group comparisons (p < .05), and minority Muslims reported more nervous tension and depressed mood than majority Muslims (p < .05). In logistic regression models, minority Muslims had greater odds of high stress than majority Muslims (OR 2.00, 95% CI 1.18-3.39). Minority Muslims had greater odds of stress (OR 3.05, 95% CI 1.51-6.17) and nervous tension (OR 3.37, 95% CI 1.66-6.87) than majority Londoners. Financial comfort reduced odds of stress and symptoms in all models. Socioeconomic situation, immigration history, and minority ethnicity appear to influence the relationship between religious identity and psychosomatic symptoms in Bangladeshi women. Attention to personal and socioeconomic context is important for research examining the association between religion and mental health
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