Large sulfur isotope fractionations in Martian sediments at Gale crater

Variability in the sulfur isotopic composition in sediments can reflect atmospheric, geologic and biological processes. Evidence for ancient fluvio-lacustrine environments at Gale crater on Mars and a lack of efficient crustal recycling mechanisms on the planet suggests a surface environment that was once warm enough to allow the presence of liquid water, at least for discrete periods of time, and implies a greenhouse effect that may have been influenced by sulfur-bearing volcanic gases. Here we report in situ analyses of the sulfur isotopic compositions of SO2 volatilized from ten sediment samples acquired by NASA’s Curiosity rover along a 13 km traverse of Gale crater. We find large variations in sulfur isotopic composition that exceed those measured for Martian meteorites and show both depletion and enrichment in 34S. Measured values of δ34S range from −47 ± 14‰ to 28 ± 7‰, similar to the range typical of terrestrial environments. Although limited geochronological constraints on the stratigraphy traversed by Curiosity are available, we propose that the observed sulfur isotopic signatures at Gale crater can be explained by equilibrium fractionation between sulfate and sulfide in an impact-driven hydrothermal system and atmospheric processing of sulfur-bearing gases during transient warm periods

Atmospheric Evolution

Earth's atmosphere has evolved as volatile species cycle between the atmosphere, ocean, biomass and the solid Earth. The geochemical, biological and astrophysical processes that control atmospheric evolution are reviewed from an "Earth Systems" perspective, with a view not only to understanding the history of Earth, but also to generalizing to other solar system planets and exoplanets.Comment: 34 pages, 3 figures, 2 tables. Accepted as a chapter in "Encyclopaedia of Geochemistry", Editor Bill White, Springer-Nature, 201

Transposing tirtha: Understanding religious reforms and locative piety in early modern Hinduism

The paper deals with a historical and hitherto obscure case of de-commercialisation of sacred geography of India. Sahajanand Swami, an eighteenth century religious leader from Gujarat who became popular as Bhagwan Swaminarayan took an initiative to eliminate corruption in Dwarka, one of the most sacred destination in Hindu imagination. He also attempted to transpose the piety of Dwarka and recreate a parallel religious experience at Vadtal, an important site in Swaminarayan Hinduism. This process of making sacred sites more egalitarian is classified here as a 'religious reform'. The paper assesses this bivalent pursuit as an institutional reform within religion as well as a religious process in the context of piety, authority and orthodoxy. Through the example of Sahajanand Swami, it is argued to calibrate the colonial paradigm of reform that was largely contextual to social issues and western thought and failed to appreciate the religious reforms of that era. By constructing a nuanced typology of 'religious reform' distinct from 'social reforms', the paper eventually calls for a reassessment of religious figures who have significantly contributed in reforming the Hindu tradition in the medieval and modern era

Predictors of positive health in disability pensioners: a population-based questionnaire study using Positive Odds Ratio

BACKGROUND: Determinants of ill-health have been studied far more than determinants of good and improving health. Health promotion measures are important even among individuals with chronic diseases. The aim of this study was to find predictors of positive subjective health among disability pensioners (DPs) with musculoskeletal disorders. METHODS: Two questionnaire surveys were performed among 352 DPs with musculoskeletal disorders. Two groups were defined: DPs with positive health and negative health, respectively. In consequence with the health perspective in this study the conception Positive Odds Ratio was defined and used in the logistic regression analyses instead of the commonly used odds ratio. RESULTS: Positive health was associated with age ≥ 55 years, not being an immigrant, not having fibromyalgia as the main diagnosis for granting an early retirement, no regular use of analgesics, a high ADL capacity, a positive subjective health preceding the study period, and good quality of life. CONCLUSION: Positive odds ratio is a concept well adapted to theories of health promotion. It can be used in relation to positive outcomes instead of risks. Suggested health promotion and secondary prevention efforts among individuals with musculoskeletal disorders are 1) to avoid a disability pension for individuals <55 years of age; if necessary, to make sure rehabilitation actions continue, 2) to increase efforts to support immigrants to adjust to circumstances connected to ill-health and retirement, 3) to pay special attention to individuals with fibromyalgia and other general pain disorders, and 4) to strengthen ADL activities to support an independent active life among disability pensioners

PLEKHA7 Is an Adherens Junction Protein with a Tissue Distribution and Subcellular Localization Distinct from ZO-1 and E-Cadherin

The pleckstrin-homology-domain-containing protein PLEKHA7 was recently identified as a protein linking the E-cadherin-p120 ctn complex to the microtubule cytoskeleton. Here we characterize the expression, tissue distribution and subcellular localization of PLEKHA7 by immunoblotting, immunofluorescence microscopy, immunoelectron microscopy, and northern blotting in mammalian tissues. Anti-PLEKHA7 antibodies label the junctional regions of cultured kidney epithelial cells by immunofluorescence microscopy, and major polypeptides of Mr ∼135 kDa and ∼145 kDa by immunoblotting of lysates of cells and tissues. Two PLEKHA7 transcripts (∼5.5 kb and ∼6.5 kb) are detected in epithelial tissues. PLEKHA7 is detected at epithelial junctions in sections of kidney, liver, pancreas, intestine, retina, and cornea, and its tissue distribution and subcellular localization are distinct from ZO-1. For example, PLEKHA7 is not detected within kidney glomeruli. Similarly to E-cadherin, p120 ctn, β-catenin and α-catenin, PLEKHA7 is concentrated in the apical junctional belt, but unlike these adherens junction markers, and similarly to afadin, PLEKHA7 is not localized along the lateral region of polarized epithelial cells. Immunoelectron microscopy definitively establishes that PLEKHA7 is localized at the adherens junctions in colonic epithelial cells, at a mean distance of 28 nm from the plasma membrane. In summary, we show that PLEKHA7 is a cytoplasmic component of the epithelial adherens junction belt, with a subcellular localization and tissue distribution that is distinct from that of ZO-1 and most AJ proteins, and we provide the first description of its distribution and localization in several tissues

Natural selection on cork oak: allele frequency reveals divergent selection in cork oak populations along a temperature cline

A recent study of population divergence at neutral markers and adaptive traits in cork oak has observed an association between genetic distances at locus QpZAG46 and genetic distances for leaf size and growth. In that study it was proposed that certain loci could be linked to genes encoding for adaptive traits in cork oak and, thus, could be used in adaptation studies. In order to investigate this hypothesis, here we (1) looked for associations between molecular markers and a set of adaptive traits in cork oak, and (2) explored the effects of the climate on among-population patterns in adaptive traits and molecular markers. For this purpose, we chose 9-year-old plants originating from thirteen populations spanning a broad range of climatic conditions. Plants established in a common garden site were genotyped at six nuclear microsatellites and phenotypically characterized for six functional traits potentially related to plant performance. Our results supported the proposed linkage between locus QpZAG46 and genes encoding for leaf size and growth. Temperature caused adaptive population divergence in leaf size and growth, which was expressed as differences in the frequencies of the alleles at locus QpZAG46

Association between Low Density Lipoprotein Receptor-Related Protein 2 Gene Polymorphisms and Bone Mineral Density Variation in Chinese Population

Low density lipoprotein receptor-related protein 2 gene (LRP2) is located next to the genomic region showing suggestive linkage with both hip and wrist bone mineral density (BMD) phenotypes. LRP2 knockout mice showed severe vitamin D deficiency and bone disease, indicating the involvement of LRP2 in the preservation of vitamin D metabolites and delivery of the precursor to the kidney for the generation of 1α,25(OH)2D3. In order to investigate the contribution of LRP2 gene polymorphisms to the variation of BMD in Chinese population, a total of 330 Chinese female-offspring nuclear families with 1088 individuals and 400 Chinese male-offspring nuclear families with 1215 individuals were genotyped at six tagSNPs of the LRP2 gene (rs2389557, rs2544381, rs7600336, rs10210408, rs2075252 and rs4667591). BMD values at the lumbar spine 1–4 (L1-4) and hip sites were measured by DXA. The association between LRP2 polymorphisms and BMD phenotypes was assessed by quantitative transmission disequilibrium tests (QTDTs) in female- and male-offspring nuclear families separately. In the female-offspring nuclear families, rs2075252 and haplotype GA of rs4667591 and rs2075252 were identified in the nominally significant total association with peak BMD at L1-4; however, no significant within-family association was found between peak BMD at the L1-4 and hip sites and six tagSNPs or haplotypes. In male-offspring nuclear families, neither the six tagSNPs nor the haplotypes was in total association or within-family association with the peak BMD variation at the L1-4 and hip sites by QTDT analysis. Our findings suggested that the polymorphisms of LRP2 gene is not a major factor that contributes to the peak BMD variation in Chinese population

Cardiac telocytes — their junctions and functional implications

Telocytes (TCs) form a cardiac network of interstitial cells. Our previous studies have shown that TCs are involved in heterocellular contacts with cardiomyocytes and cardiac stem/progenitor cells. In addition, TCs frequently establish ‘stromal synapses’ with several types of immunoreactive cells in various organs (www.telocytes.com). Using electron microscopy (EM) and electron microscope tomography (ET), we further investigated the interstitial cell network of TCs and found that TCs form ‘atypical’ junctions with virtually all types of cells in the human heart. EM and ET showed different junction types connecting TCs in a network (puncta adhaerentia minima, processus adhaerentes and manubria adhaerentia). The connections between TCs and cardiomyocytes are ‘dot’ junctions with nanocontacts or asymmetric junctions. Junctions between stem cells and TCs are either ‘stromal synapses’ or adhaerens junctions. An unexpected finding was that TCs have direct cell–cell (nano)contacts with Schwann cells, endothelial cells and pericytes. Therefore, ultrastructural analysis proved that the cardiac TC network could integrate the overall ‘information’ from vascular system (endothelial cells and pericytes), nervous system (Schwann cells), immune system (macrophages, mast cells), interstitium (fibroblasts, extracellular matrix), stem cells/progenitors and working cardiomyocytes. Generally, heterocellular contacts occur by means of minute junctions (point contacts, nanocontacts and planar contacts) and the mean intermembrane distance is within the macromolecular interaction range (10–30 nm). In conclusion, TCs make a network in the myocardial interstitium, which is involved in the long-distance intercellular signaling coordination. This integrated interstitial system appears to be composed of large homotropic zones (TC–TC junctions) and limited (distinct) heterotropic zones (heterocellular junctions of TCs)

The SR-BI Partner PDZK1 Facilitates Hepatitis C Virus Entry

Entry of hepatitis C virus (HCV) into hepatocytes is a multi-step process that involves a number of different host cell factors. Following initial engagement with glycosaminoglycans and the low-density lipoprotein receptor, it is thought that HCV entry proceeds via interactions with the tetraspanin CD81, scavenger receptor class B type I (SR-BI), and the tight-junction proteins claudin-1 (CLDN1) and occludin (OCLN), culminating in clathrin-dependent endocytosis of HCV particles and their pH-dependent fusion with endosomal membranes. Physiologically, SR-BI is the major receptor for high-density lipoproteins (HDL) in the liver, where its expression is primarily controlled at the post-transcriptional level by its interaction with the scaffold protein PDZK1. However, the importance of interaction with PDZK1 to the involvement of SR-BI in HCV entry is unclear. Here we demonstrate that stable shRNA-knockdown of PDZK1 expression in human hepatoma cells significantly reduces their susceptibility to HCV infection, and that this effect can be reversed by overexpression of full length PDZK1 but not the first PDZ domain of PDZK1 alone. Furthermore, we found that overexpression of a green fluorescent protein chimera of the cytoplasmic carboxy-terminus of SR-BI (amino acids 479–509) in Huh-7 cells resulted in its interaction with PDZK1 and a reduced susceptibility to HCV infection. In contrast a similar chimera lacking the final amino acid of SR-BI (amino acids 479–508) failed to interact with PDZK1 and did not inhibit HCV infection. Taken together these results indicate an indirect involvement of PDZK1 in HCV entry via its ability to interact with SR-BI and enhance its activity as an HCV entry factor