Towards understanding how surface life can affect interior geological processes: a non-equilibrium thermodynamics approach

Life has significantly altered the Earth’s atmosphere, oceans and crust. To what extent has it also affected interior geological processes? To address this question, three models of geological processes are formulated: mantle convection, continental crust uplift and erosion and oceanic crust recycling. These processes are characterised as non-equilibrium thermodynamic systems. Their states of disequilibrium are maintained by the power generated from the dissipation of energy from the interior of the Earth. Altering the thickness of continental crust via weathering and erosion affects the upper mantle temperature which leads to changes in rates of oceanic crust recycling and consequently rates of outgassing of carbon dioxide into the atmosphere. Estimates for the power generated by various elements in the Earth system are shown. This includes, inter alia, surface life generation of 264 TW of power, much greater than those of geological processes such as mantle convection at 12 TW. This high power results from life’s ability to harvest energy directly from the sun. Life need only utilise a small fraction of the generated free chemical energy for geochemical transformations at the surface, such as affecting rates of weathering and erosion of continental rocks, in order to affect interior, geological processes. Consequently when assessing the effects of life on Earth, and potentially any planet with a significant biosphere, dynamical models may be required that better capture the coupled nature of biologically-mediated surface and interior processes

Scaling metagenome sequence assembly with probabilistic de Bruijn graphs

Deep sequencing has enabled the investigation of a wide range of environmental microbial ecosystems, but the high memory requirements for {\em de novo} assembly of short-read shotgun sequencing data from these complex populations are an increasingly large practical barrier. Here we introduce a memory-efficient graph representation with which we can analyze the k-mer connectivity of metagenomic samples. The graph representation is based on a probabilistic data structure, a Bloom filter, that allows us to efficiently store assembly graphs in as little as 4 bits per k-mer, albeit inexactly. We show that this data structure accurately represents DNA assembly graphs in low memory. We apply this data structure to the problem of partitioning assembly graphs into components as a prelude to assembly, and show that this reduces the overall memory requirements for {\em de novo} assembly of metagenomes. On one soil metagenome assembly, this approach achieves a nearly 40-fold decrease in the maximum memory requirements for assembly. This probabilistic graph representation is a significant theoretical advance in storing assembly graphs and also yields immediate leverage on metagenomic assembly

Peroxiredoxin 4, a novel circulating biomarker for oxidative stress and the risk of incident cardiovascular disease and all-cause mortality

BACKGROUND: Oxidative stress has been suggested to play a key role in the development of cardiovascular disease (CVD). The aim of our study was to investigate the associations of serum peroxiredoxin 4 (Prx4), a hydrogen peroxide-degrading peroxidase, with incident CVD and all-cause mortality. We subsequently examined the incremental value of Prx4 for the risk prediction of CVD compared with the Framingham risk score (FRS). METHODS AND RESULTS: We performed Cox regression analyses in 8141 participants without history of CVD (aged 28 to 75 years; women 52.6%) from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study in Groningen, The Netherlands. Serum Prx4 was measured by an immunoluminometric assay in baseline samples. Main outcomes were: (1) incident CVD events or CVD mortality and (2) all-cause mortality during a median follow-up of 10.5 years. In total, 708 participants (7.8%) developed CVD events or CVD mortality, and 517 participants (6.3%) died. Baseline serum Prx4 levels were significantly higher in participants with incident CVD events or CVD mortality and in those who died than in participants who remained free of outcomes (both P<0.001). In multivariable models with adjustment for Framingham risk factors, hazard ratios were 1.16 (95% CI 1.06 to 1.27, P<0.001) for incident CVD events or CVD mortality and 1.17 (95% CI 1.06 to 1.29, P=0.003) for all-cause mortality per doubling of Prx4 levels. After the addition of Prx4 to the FRS, the net reclassification improvement was 2.7% (P=0.01) using 10-year risk categories of CVD. CONCLUSIONS: Elevated serum Prx4 levels are associated with a significantly higher risk of incident CVD events or CVD mortality and all-cause mortality after adjustment for clinical risk factors. The addition of Prx4 to the FRS marginally improved risk prediction of future CVD

Place attachment in deprived neighbourhoods: The impacts of population turnover and social mix

This paper examines the determinants of individual place attachment, focussing in particular on differences between deprived and others neighbourhoods, and on the impacts of population turnover and social mix. It uses a multi-level modelling approach to take account of both individual- and neighbourhood-level determinants. Data are drawn from a large sample government survey, the Citizenship Survey 2005, to which a variety of neighbourhood-level data have been attached. The paper argues that attachment is significantly lower in more deprived neighbourhoods primarily because these areas have weaker social cohesion but that, in other respects, the drivers of attachment are the same. Turnover has modest direct impacts on attachment through its effect on social cohesion. Social mix has very limited impacts on attachment and the effects vary between social groups. In general, higher status or more dominant groups appear less tolerant of social mix

Defining and measuring displacement: is relocation from restructured neighbourhoods always unwelcome and disruptive?

Current regeneration policy has been described as ‘state-led gentrification’, with comparisons made with the ‘social disruption’ caused by slum clearance of the 1950s and 1960s. This article takes issue with this approach in relation to the study of the restructuring of social housing areas. The terms ‘forced relocation’ and ‘displacement’ are often too crude to describe what actually happens within processes of restructuring and the effects upon residents. Displacement in particular has important dimensions other than the physical one of moving. Evidence from a recent study of people who have moved out of restructured areas shows that although there is some evidence of physical displacement, there is little evidence of social or psychosocial displacement after relocation. Prior attitudes to moving and aspects of the process of relocation—the degree of choice and distance involved—are important moderators of the outcomes. Issues of time and context are insufficiently taken into consideration in studies and accounts of restructuring, relocation and displacement

Pasos Hacia La Salud: a randomized controlled trial of an internet-delivered physical activity intervention for Latinas.

BackgroundInternet access has grown markedly in Latinos during the past decade. However, there have been no Internet-based physical activity interventions designed for Latinos, despite large disparities in lifestyle-related conditions, such as obesity and diabetes, particularly in Latina women. The current study tested the efficacy of a 6-month culturally adapted, individually tailored, Spanish-language Internet-based physical activity intervention.MethodsInactive Latinas (N = 205) were randomly assigned to the Tailored Physical Activity Internet Intervention or the Wellness Contact Control Internet Group. Participants in both groups received emails on a tapered schedule over 6 months to alert them to new content on the website. The primary outcome was minutes/week of moderate to vigorous physical activity (MVPA) at 6 months as measured by the 7-Day Physical Activity Recall; activity was also measured by accelerometers. Data were collected between 2011 and 2014 and analyzed in 2015 at the University of California, San Diego.ResultsIncreases in minutes/week of MVPA were significantly greater in the Intervention Group compared to the Control Group (mean difference = 50.00, SE = 9.5, p &lt; 0.01). Increases in objectively measured MVPA were also significantly larger in the Intervention Group (mean differences = 31.0, SE = 10.7, p &lt; .01). The Intervention Group was also significantly more likely to meet national physical activity guidelines at 6 months (OR = 3.12, 95% CI 1.46-6.66, p &lt; .05).ConclusionFindings from the current study suggest that this Internet-delivered individually tailored intervention successfully increased MVPA in Latinas compared to a Wellness Contact Control Internet Group.Trial registrationNCT01834287

Gromov-Hausdorff-like distance function defined in the aspect of Riemannian submanifold theory

In this paper, we discuss how a Gromov-Hausdorff-like distance function over the space of all isometric classes of compact $C^k$-Riemannian manifolds should be defined in the aspect of the Riemannan submanifold theory, where $k\geq 1$. The most important fact in this discussion is as follows. The Hausdorff distance function between two spheres of mutually distinct radii isometrically embedded into the hypebolic space of curvature $c$ converges to zero as $c\to-\infty$. The key in the construction of the Gromov-Hausdorff-like distance function given in this paper is to define the distance of two $C^{k+1}$-isometric embeddings of distinct compact $C^k$-Riemannian manifolds into a higher dimensional Riemannian manifold by using the Hausdorff distance function in the tangent bundle of order $k+1$ equipped with the Sasaki metric. Furthermore, we show that the convergence of a sequence of compact Riemannian manifolds with respect to this distance function coincides with the convergence in the sense of R. S. Hamilton.Comment: 14 page

Two-year use of flash glucose monitoring is associated with sustained improvement of glycemic control and quality of life (FLARE-NL-6)

INTRODUCTION: The FreeStyle Libre (FSL) is a flash glucose monitoring (FGM) system. The Flash Monitor Register in the Netherlands (FLARE-NL-4) study previously demonstrated the positive effects of FSL-FGM use during 1 year on glycemic control, quality of life and disease burden among persons with diabetes mellitus (DM). The present follow-up study assesses the effects of FSL-FGM after 2 years. RESEARCH DESIGN AND METHODS: Patients included in the FLARE-NL-4 study who continued FSL-FGM during the 1-year study period were invited to participate (n=687). Data were collected using questionnaires (the 12-Item Short Form Health Survey version 2 (SF-12(v2)) and the EuroQol 5-Dimension 3-Level (EQ-5D-3L) for quality of life), including self-reported hemoglobin A1c (HbA1c). RESULTS: A total of 342 patients agreed to participate: mean age 48.0 (±15.6) years, 52% men and 79.5% with type 1 DM. HbA1c decreased from 60.7 (95% CI 59.1 to 62.3) mmol/mol before use of FSL-FGM to 57.3 (95% CI 55.8 to 58.8) mmol/mol after 1 year and 57.8 (95% CI 56.0 to 59.5) mmol/mol after 2 years. At the end of the 2-year follow-up period, 260 (76%) persons were still using the FSL-FGM and 82 (24%) had stopped. The main reason for stopping FSL-FGM was financial constraints (55%). Concerning the whole 2-year period, there was a significant decrease in HbA1c among persons who continued use of FSL-FGM (−3.5 mmol/mol, 95% CI −6.4 to –0.7), while HbA1c was unaltered compared with baseline among persons who stopped FSL-FGM (−2.4 mmol/mol, 95% CI −7.5 to 2.7): difference between groups 2.2 (95% CI −1.3 to 5.8) mmol/mol. After 2 years, persons who continued use of FSL-FGM had higher SF-12 mental component score and higher EQ-5D Dutch tariff score and felt less often anxious or depressed compared with persons who discontinued FSL-FGM. CONCLUSIONS: Although the considerable number of non-responders limits generalizability, this study suggests that persons who continue to use FSL-FGM for 2 years may experience sustained improvement in glycemic control and quality of life