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Influence of smectite and salinity on the imaginary and surface conductivity of volcanic rocks

We investigate the complex conductivity behaviour of natural volcanic rocks containing variable amounts of smectite in multi-salinity experiments. We compare the results with relationships established for sandstones. Considering only samples with little volume of metallic particles, we observe similar and small phase-angles at low frequency for all samples at all salinities (less than 25 mrad at 1

Electrical resistivity tomography and time-domain induced polarization field investigations of geothermal areas at Krafla, Iceland : Comparison to borehole and laboratory frequency-domain electrical observations

Interaction of H2S and basaltic rocks in volcanic geothermal areas can originate from natural up-flow of magmatic fluids or H2S artificial re-injection in relation to geothermal exploitation, both causing pyrite mineralization. We study the possibility to track these processes with electrical impedance field measurements. Electrical Resistivity Tomography (ERT) and Time- Domain Induced Polarizatio

Tracking Magmatic Hydrogen Sulfur Circulations Using Electrical Impedance : Complex Electrical Properties of Core Samples at the Krafla Volcano, Iceland

Interaction of H2S escaping from magma and basaltic rocks leads to pyrite mineralization, witnessing active hydrothermal circulation. We study the possibility to track this process using geoelectrical methods. Complex conductivity spectra of 30 core samples from the Krafla volcano, Iceland, measured in the laboratory, indicate that pyrite can be discriminated from other minerals present in volcani

The role of smectites in the electrical conductivity of active hydrothermal systems : Electrical properties of core samples from Krafla volcano, Iceland

The underground circulation of hot water, of interest for geothermal energy production, is often indirectly inferred from the presence of minerals formed by hydrothermal alteration at different temperatures. Clay minerals, such as smectite and chlorite, can be mapped from the surface using electrical soundings and give information about the structure of the geothermal system. Here, we investigate

Characterization of pre-analytical sample handling effects on a panel of Alzheimer's disease–related blood-based biomarkers : Results from the Standardization of Alzheimer's Blood Biomarkers (SABB) working group

Introduction: Pre-analytical sample handling might affect the results of Alzheimer's disease blood-based biomarkers. We empirically tested variations of common blood collection and handling procedures. Methods: We created sample sets that address the effect of blood collection tube type, and of ethylene diamine tetraacetic acid plasma delayed centrifugation, centrifugation temperature, aliquot vol

Bio-based nonionic antimicrobial polymers with isatin or indole functionality

Infections by pathogenic microorganisms remain one of the most serious concerns in several areas, particularly in hygienic applications. Antimicrobials have been used to combat these infections. Using small molecular antimicrobials as additives or coatings is an industrially adopted strategy. However, small antimicrobial agents always suffer from many drawbacks, such as leaching potential, toxicit

From Djerba to Glasgow : have declarations on tourism and climate change brought us any closer to meaningful climate action?

The United Nations has declared climate change a code-red for humanity and the 2020s the decisive decade to avoid dangerous climate disruption. The 26th Conference of the Parties in Glasgow, Scotland represents a milestone event and potentially the last chance to keep the Paris Climate Agreement 1.5 °C policy goal within reach. The tourism sector has responded to this critical moment by releasing

The long-term consequences of parental death in childhood on mortality and the role of socioeconomic status : evidence from Sweden at the turn of the 20th century

The death of a parent during childhood is a major traumatic event. While there is a good understanding of the early-life effects of parental loss, the evidence regarding its impact on adult mortality is still scarce. Accordingly, the aim of this article is to study the long-term consequences of parental loss on mortality with a particular focus on differences by socioeconomic status (SES) of the f

Network Modeling and Performance Evaluation for G.fast

G.fast is a gap-bridging broadband technology on the way to a fully optical access network. G.fast is deployed in hybrid fiber-copper access networks and aiming to offer ubiquitous low-cost and high-speed broadband. For network operators, it is crucial to determine the location from where to deploy G.fast, the expected network coverage, and the expected bit rates. In this paper, we perform network

Amyloid-β precursor protein processing and oxidative stress are altered in human iPSC-derived neuron and astrocyte co-cultures carrying presenillin-1 gene mutations following spontaneous differentiation

INTRODUCTION: Presenilin-1 (PSEN1) gene mutations are the most common cause of familial Alzheimer's disease (fAD) and are known to interfere with activity of the membrane imbedded γ-secretase complex. PSEN1 mutations have been shown to shift Amyloid-β precursor protein (AβPP) processing toward amyloid-β (Aβ) 1-42 production. However, less is known about whether PSEN1 mutations may alter the activi

Application of Airy beam light sheet microscopy to examine early neurodevelopmental structures in 3D hiPSC-derived human cortical spheroids

BACKGROUND: The inability to observe relevant biological processes in vivo significantly restricts human neurodevelopmental research. Advances in appropriate in vitro model systems, including patient-specific human brain organoids and human cortical spheroids (hCSs), offer a pragmatic solution to this issue. In particular, hCSs are an accessible method for generating homogenous organoids of dorsal

Impact of insufficient sleep on dysregulated blood glucose control under standardised meal conditions

Aims/hypothesis: Sleep, diet and exercise are fundamental to metabolic homeostasis. In this secondary analysis of a repeated measures, nutritional intervention study, we tested whether an individual’s sleep quality, duration and timing impact glycaemic response to a breakfast meal the following morning. Methods: Healthy adults’ data (N = 953 [41% twins]) were analysed from the PREDICT dietary inte

Preserved periprosthetic bone stock at 5 years post-operatively with uncemented short hip stem in both collared and collarless version

Introduction: Previous bone density studies have generally shown bone resorption around both cemented and uncemented total hip arthroplasty (THA) stems. This is presumed to be due to stress shielding. Short stems have been introduced partly to preserve bone in the proximal femur by a more physiological loading of the bone. The purpose of this study was to evaluate bone remodeling around a short, f

Downturn in Childhood Bone Mass : A Cross-Sectional Study Over Four Decades

Screen time and physical inactivity have increased among children. As physical activity is a determinant of bone mass, there is a concern that children today have lower bone mass than earlier. If this is true, fractures may become more common in the future. In 2017–2018, we used single-photon absorptiometry (SPA) to measure distal forearm bone mineral density (BMD; mg/cm2) in a normative cohort of

Physical Activity at Growth Induce Bone Mass Benefits Into Adulthood : A 15-Year Prospective Controlled Study

Daily school physical activity (PA) improves musculoskeletal traits. Whether or not benefits remain in adulthood is debated. We included in this study 131 children that took part in an intervention with 40 minutes of PA per school day (200 minutes per week) from age 6 to 9 years (grade one) to age 14 to 16 years (grade nine), whereas 78 children continued with national recommended school physical

Azide-Functionalized Naphthoxyloside as a Tool for Glycosaminoglycan Investigations

We present a xylosylated naphthoxyloside carrying a terminal azide functionality that can be used for conjugation using click chemistry. We show that this naphthoxyloside serves as a substrate for β4GalT7 and induces the formation of soluble glycosaminoglycan (GAG) chains with physiologically relevant lengths and sulfation patterns. Finally, we demonstrate its usefulness by conjugation to the Alex

Incidence and Predictors of Heart Failure in Patients With Atrial Fibrillation

Background: Heart failure (HF) is a frequent cause of hospitalization and death in patients with atrial fibrillation (AF). Identifying AF patients at risk of HF hospitalization could help select individuals for intensive follow-up and treatment. Methods: We pooled data from 3 randomized trials (ACTIVE-A, RE-LY, AVERROES) of AF patients, for derivation and internal validation of a risk score for fi