852 research outputs found

    Biotic and stable-isotope characterization of the Toarcian Ocean Anoxic Event through a carbonate–clastic sequence from Somerset, UK

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    This study focuses on a condensed sequence of alternating carbonate–clastic sediments of the Barrington Member, Beacon Limestone Formation (latest Pliensbachian to early Toarcian) from Somerset (SW England). Abundant ammonites confirm (apart from the absence of the Clevelandicum and Tenuicostatum ammonite subchronozones) the presence of Hawskerense Subchronozone to Fallaciosum–Bingmanni subchronozones. Well-preserved, sometimes diverse assemblages of ostracods, foraminifera, nannofossils and lowdiversity dinoflagellate assemblages support the chronostratigraphic framework. Stable-isotope analyses demonstrate the presence of a carbon isotope excursion, relating to the Toarcian Oceanic Anoxic Event, within the early Toarcian. Faunal, geochemical and sedimentological evidence suggest that deposition largely took place in a relatively deep-water (subwave base), mid-outer shelf environment under a well-mixed water column. However, reduced benthic diversity, the presence of weakly laminated sediments and changes in microplankton assemblage composition within the Toarcian Oceanic Anoxic Event indicates dysoxic, but probably never anoxic, bottom-water conditions during this event. The onset of the carbon isotope excursion coincides with extinction in the nannofossils and benthos, including the disappearance of the ostracod suborder Metacopina. Faunal evidence indicates connectivity with the Mediterranean region, not previously recorded for the UK during the early Toarcian

    The impact of cardiac comorbidity sequence at baseline and mortality risk in type 2 Diabetes Mellitus: a retrospective population-based cohort study

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    Introduction: The presence of multiple comorbidities increases the risk of all-cause mortality, but the effects of the comorbidity sequence before the baseline date on mortality remain unexplored. This study investigated the relationship between coronary heart disease (CHD), atrial fibrillation (AF) and heart failure (HF) through their sequence of development and the effect on all-cause mortality risk in type 2 diabetes mellitus. Methods: This study included patients with type 2 diabetes mellitus prescribed antidiabetic/cardiovascular medications in public hospitals of Hong Kong between 1 January 2009 and 31 December 2009, with follow-up until death or 31 December 2019. The Cox regression was used to identify comorbidity sequences predicting all-cause mortality in patients with different medication subgroups. Results: A total of 249,291 patients (age: 66.0 ± 12.4 years, 47.4% male) were included. At baseline, 7564, 10,900 and 25,589 patients had AF, HF and CHD, respectively. Over follow-up (3524 ± 1218 days), 85,870 patients died (mortality rate: 35.7 per 1000 person-years). Sulphonylurea users with CHD developing later and insulin users with CHD developing earlier in the disease course had lower mortality risks. Amongst insulin users with two of the three comorbidities, those with CHD with preceding AF (hazard ratio (HR): 3.06, 95% CI: [2.60–3.61], p < 0.001) or HF (HR: 3.84 [3.47–4.24], p < 0.001) had a higher mortality. In users of lipid-lowering agents with all three comorbidities, those with preceding AF had a higher risk of mortality (AF-CHD-HF: HR: 3.22, [2.24–4.61], p < 0.001; AF-HF-CHD: HR: 3.71, [2.66–5.16], p < 0.001). Conclusions: The sequence of comorbidity development affects the risk of all-cause mortality to varying degrees in diabetic patients on different antidiabetic/cardiovascular medications

    A Lang Park mystery: Analysis of remains from a 19th century burial in Brisbane, Queensland

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    Salvage excavation of the Suncorp Stadium (Lang Park) redevelopment site in Brisbane revealed almost 400 graves. Originally known as the North Brisbane Burial Grounds, it was the site of Brisbane's principal cemetery between 1843 and 1875. A grave in the Anglican section of the cemetery yielded several teeth and associated non-dental bone fragments, and stature data derived from the coffin indicate a child burial. Observation of the stages of tooth eruption, resorption, and formation revealed evidence for two children, one aged approximately three years old and the other aged 12. An examination of the coffin furniture showed that the coffin was bought by a wealthy Anglican family, and DNA analyses suggest that the older individual was of Eastern European descent. These results suggest the burial of the older child in the same grave as the younger was most likely clandestine, and highlight the importance of post-excavation analyses to the interpretation of Australian cemeteries

    Molecular Identification of Rickettsial Endosymbionts in the Non-Phagotrophic Volvocalean Green Algae

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    Background: The order Rickettsiales comprises Gram-negative obligate intracellular bacteria (also called rickettsias) that are mainly associated with arthropod hosts. This group is medically important because it contains human-pathogenic species that cause dangerous diseases. Until now, there has been no report of non-phagotrophic photosynthetic eukaryotes, such as green plants, harboring rickettsias. Methodology/Principal Findings: We examined the bacterial endosymbionts of two freshwater volvocalean green algae: unicellular Carteria cerasiformis and colonial Pleodorina japonica. Epifluorescence microscopy using 49-6-deamidino-2phenylindole staining revealed the presence of endosymbionts in all C. cerasiformis NIES-425 cells, and demonstrated a positive correlation between host cell size and the number of endosymbionts. Strains both containing and lacking endosymbionts of C. cerasiformis (NIES-425 and NIES-424) showed a.10-fold increase in cell number and typical sigmoid growth curves over 192 h. A phylogenetic analysis of 16 S ribosomal (r)RNA gene sequences from the endosymbionts of C. cerasiformis and P. japonica demonstrated that they formed a robust clade (hydra group) with endosymbionts of various non-arthropod hosts within the family Rickettsiaceae. There were significantly fewer differences in the 16 S rRNA sequences of the rickettsiacean endosymbionts between C. cerasiformis and P. japonica than in the chloroplast 16 S rRNA or 18 S rRNA of the host volvocalean cells. Fluorescence in situ hybridization demonstrated the existence of the rickettsiacea

    Muscle weakness in Ryr1 I4895T/WT knock-in mice as a result of reduced ryanodine receptor Ca 2+ ion permeation and release from the sarcoplasmic reticulum

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    The type 1 isoform of the ryanodine receptor (RYR1) is the Ca 2+ release channel of the sarcoplasmic reticulum (SR) that is activated during skeletal muscle excitation–contraction (EC) coupling. Mutations in the RYR1 gene cause several rare inherited skeletal muscle disorders, including malignant hyperthermia and central core disease (CCD). The human RYR1 I4898T mutation is one of the most common CCD mutations. To elucidate the mechanism by which RYR1 function is altered by this mutation, we characterized in vivo muscle strength, EC coupling, SR Ca 2+ content, and RYR1 Ca 2+ release channel function using adult heterozygous Ryr1 I4895T/+ knock-in mice (IT/+). Compared with age-matched wild-type (WT) mice, IT/+ mice exhibited significantly reduced upper body and grip strength. In spite of normal total SR Ca 2+ content, both electrically evoked and 4-chloro- m -cresol–induced Ca 2+ release were significantly reduced and slowed in single intact flexor digitorum brevis fibers isolated from 4–6-mo-old IT/+ mice. The sensitivity of the SR Ca 2+ release mechanism to activation was not enhanced in fibers of IT/+ mice. Single-channel measurements of purified recombinant channels incorporated in planar lipid bilayers revealed that Ca 2+ permeation was abolished for homotetrameric IT channels and significantly reduced for heterotetrameric WT:IT channels. Collectively, these findings indicate that in vivo muscle weakness observed in IT/+ knock-in mice arises from a reduction in the magnitude and rate of RYR1 Ca 2+ release during EC coupling that results from the mutation producing a dominant-negative suppression of RYR1 channel Ca 2+ ion permeation

    The ideal job-seeker norm: unemployment and marital privileges in the professional middle-class

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    Objective: To understand how heterosexual US married parents interpret and respond to a spouse's unemployment and subsequent job-searching. Background: The pervasiveness of employment uncertainty, and unemployment, may propel families to embrace gender egalitarian norms. Quantitative research finds that this possibility is not borne out. Qualitative research has sought to illuminate mechanisms as to how gender norms persist even during a time that is optimal for dismantling them, but these mechanisms remain unclear. Method: Seventy-two in-depth interviews were conducted with a nonrandom sample of heterosexual, professional, dual-earner, married, unemployed women, men, and their spouses in the United States. Follow-up interviews were conducted with 35 participants. Intensive family observations were conducted with four families, two of unemployed men, and two of unemployed women. Results: Unemployed women, men, and spouses acknowledge that a set of time-intensive activities are key for reemployment (the ideal job-seeker norm). Couples with unemployed men direct resources such as time, space, and even money to facilitate unemployed men's compliance with the ideal job-seeker norm. Couples downplay the importance of women's reemployment and do not direct similar resources to help unemployed women job-search. Conclusion: Couples preserve a traditional gender status quo, often in defiance of material realities, by actively maintaining men's position at the helm of paid work and women's at unpaid work. Implications: Linking unemployment and job-seeking with the institution of heterosexual marriage reveals novel insights into social and marital processes shaping job-seeking

    松本歯科大学学会会則

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    © Springer Nature Singapore Pte Ltd 2020. Railway industries are facing greater technical and economic challenges to increase the train speeds and hauling capacity of the trains to cope up with the growing population and increasing traffic problems. However, increasing dynamic stresses from the passage of faster and heavy haul trains progressively degrades the ballast layer and other track substructure layers which inevitably leads to excessive settlement and track instability. Nowadays, heavier concrete sleepers used in most of the ballasted tracks are subjected to even greater stresses and faster deterioration. Under Sleeper Pads (USPs) are resilient pads installed at the bottom face of concrete sleepers to increase the degree of vertical elasticity in the track structure and also with the intention of enhancing sleeper–ballast interaction to minimize dynamic stresses and subsequent track deterioration. In this study, cyclic loads from fast and heavy haul trains have been simulated using a large-scale Process Simulation Prismoidal Triaxial Apparatus (PSPTA) to investigate the performance of ballast improved by the USPs. The laboratory results indicate that the inclusion of USP at the harder interface of concrete sleeper-ballast significantly curtails the stresses transmitted and minimizes the amount of plastic deformation and degradation of ballast
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