7 research outputs found

    Color-dependent changes in humans during a verbal fluency task under colored light exposure assessed by SPA-fNIRS.

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    Light evokes robust visual and nonvisual physiological and psychological effects in humans, such as emotional and behavioral responses, as well as changes in cognitive brain activity and performance. The aim of this study was to investigate how colored light exposure (CLE) and a verbal fluency task (VFT) interact and affect cerebral hemodynamics, oxygenation, and systemic physiology as determined by systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS). 32 healthy adults (17 female, 15 male, age: 25.5 ± 4.3 years) were exposed to blue and red light for 9 min while performing a VFT. Before and after the CLE, subjects were in darkness. We found that this long-term CLE-VFT paradigm elicited distinct changes in the prefrontal cortex and in most systemic physiological parameters. The subjects' performance depended significantly on the type of VFT and the sex of the subject. Compared to red light, blue evoked stronger responses in cerebral hemodynamics and oxygenation in the visual cortex. Color-dependent changes were evident in the recovery phase of several systemic physiological parameters. This study showed that the CLE has effects that endure at least 15 min after cessation of the CLE. This underlines the importance of considering the persistent influence of colored light on brain function, cognition, and systemic physiology in everyday life

    Soil weathering dynamics and erosion in a dry oceanic area of the southern hemisphere (Otago, New Zealand)

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    Landscape evolution is driven by tectonics, climate and surface denudation. In New Zealand, tectonics and steep climatic gradients cause a dynamic landscape with intense chemical weathering, rapid soil formation, and high soil losses. In this study, soil, and elemental redistribution along two adjacent hillslopes in East Otago, New Zealand, having different landscape settings (ridge versus valley) are compared to identify soil weathering and erosion dynamics. Fallout radionuclides (239+240^{239+240}Pu) show that over the last ~ 60 years, average soil erosion rates in the valley (~ 260 [t km−2^{−2} year−1^{−1}]) are low compared to the ridge (~ 990 [t km−2^{−2} year−1^{−1}]). The ridge yields up to 26% lower soil weathering intensity than the topographical-protected valley. The lowest soil weathering intensity is found at both hilltop positions, where tors (residual rocks) are present and partially disintegrate. The soil weathering intensity increases with distance from tors, suggesting that tors rejuvenate the chemical weathering signature at the hilltop positions with fresh material. The inversed and decreasing weathering degree with all soil depth indicates that the fresh mineral contribution must be higher at the soil surface than at the bedrock weathering front. Higher erosion rates at the exposed ridge may be partially attributed to wind, consistent with rock abrasion of tors, and low local river sediment yields (56 [t km−2^{−2} year−1^{−1}]). Thus, the East Otago spatial patterns of soil chemistry and erosion are governed by tor degradation and topographic exposure

    Structural characteristics, bulk porosity and evolution of an exhumed long-lived hydrothermal system

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    The geometry and spatial variability of fracture networks and matrix porosity of fault rocks are key parameters controlling the permeability and ultimately the fluid flux along fault zones. Detailed understanding of evolution and long-term sustainability of naturally porous and permeable fault rocks is thus of prime importance for predicting the occurrence and the successful exploration of natural fault-bound hydrothermal systems. This study presents continuous structural data and matrix porosity measurements collected from a cored drillhole across a long-lived and still active fault-bound hydrothermal system in the crystalline basement of the Aar Massif (Swiss Alps). Image analysis and He-pycnometry analysis for quantification of matrix porosity of tectonites showing variable ductile and brittle deformation intensity is combined with fracture porosity calculations to develop a bulk porosity profile across this hydrothermally active fault zone. In the investigated example, a central fault core that shows a several meter wide fault breccia with consolidated gouge material of increased porosity with maximum values of 9% (He-pycnometry) and>20% (image analysis) is adjoined by several large subsidiary faults and interconnected by a intensly fractured damage zone embedded in granitic to ultramylonitic host rock showing 0.1–6% porosity. The variable degree of ductile precursors forms a succession of subparallel sealing and high-porosity structures parallel to the fault zone bridged by a dense fracture network. Fluid flow is therefore directly related to the combined effect of fractures and enhanced fault-related matrix porosity, possibly dynamically changing with time due to fracturing and precipitation cycles. This suggests a key importance of matrix porosity within fault core rocks (breccia & fault gouge) for the transport of hydrothermal fluids

    Plasmodium berghei sporozoites in nonreplicative vacuoles are eliminated by a PI3P-mediated autophagy-independent pathway.

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    The protozoan parasite Plasmodium, causative agent of malaria, invades hepatocytes by invaginating the host cell plasma membrane and forming a parasitophorous vacuole membrane (PVM). Surrounded by this PVM, the parasite undergoes extensive replication. Parasites inside a PVM provoke the Plasmodium-associated autophagy-related (PAAR) response. This is characterized by a long-lasting association of the autophagy marker protein LC3 with the PVM, which is not preceded by phosphatidylinositol 3-phosphate (PI3P)-labelling. Prior to productive invasion, sporozoites transmigrate several cells and here we describe that a proportion of traversing sporozoites become trapped in a transient traversal vacuole, provoking a host cell response that clearly differs from the PAAR response. These trapped sporozoites provoke PI3P-labelling of the surrounding vacuolar membrane immediately after cell entry, followed by transient LC3-labelling and elimination of the parasite by lysosomal acidification. Our data suggest that this PI3P response is not only restricted to sporozoites trapped during transmigration but also affects invaded parasites residing in a compromised vacuole. Thus, host cells can employ a pathway distinct from the previously described PAAR response to efficiently recognize and eliminate Plasmodium parasites. This article is protected by copyright. All rights reserved

    Systematic screening on admission for SARS-CoV-2 to detect asymptomatic infections

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    The proportion of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains elusive and the potential benefit of systematic screening during the SARS-CoV-2-pandemic is controversial. We investigated the proportion of asymptomatic inpatients who were identified by systematic screening for SARS-CoV-2 upon hospital admission. Our analysis revealed that systematic screening of asymptomatic inpatients detects a low total number of SARS-CoV-2 infections (0.1%), questioning the cost–benefit ratio of this intervention. Even when the population-wide prevalence was low, the proportion of asymptomatic carriers remained stable, supporting the need for universal infection prevention and control strategies to avoid onward transmission by undetected SARS-CoV-2-carriers during the pandemic

    Polypharmacy and Kidney Function in Community-Dwelling Adults Age 60 Years and Older: A Prospective Observational Study

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    Objectives Information on the impact of polypharmacy on kidney function in older adults is limited. We prospectively investigated the association between intake of total number of drugs or nonsteroidal anti-inflammatory drugs (NSAIDs) and kidney function. Design Our study is a prospective observational analysis of the 2-year Zurich Multiple Endpoint Vitamin D Trial in Knee Osteoarthritis Patients. Setting and participants Of the 273 participants of the original trial, 270 participants (mean age 70.3 ± 6.4 years, 53% women) were included in this observational analysis. Methods The associations between (1) total number of drugs (or NSAIDs) at baseline or (2) cumulative number of drugs (or NASAIDs) repeatedly measured over 24 months and kidney function repeatedly measured over 24 months as estimated glomerular filtration rate (eGFR) were investigated using multivariable-adjusted repeated-measures analysis. Results Per drug at baseline, kidney function decreased by 0.64 mL/min/1.73 m2 eGFR (Beta = −0.64; 95% CI −1.19 to −0.08; P = .024) over 24 months. With every additional drug taken cumulatively over 24 months, kidney function decreased by 0.39 mL/min/1.73 m2 eGFR (Beta = −0.39; 95% CI −0.63 to −0.15; P = .002). In a high-risk subgroup, per NSAID taken cumulatively over 24 months, kidney function declined by 1.21 mL/min/1.73 m2 eGFR (Beta = −1.21; 95% CI −2.35 to −0.07; P = .021). Conclusions and implications For every additional drug prescribed among older adults, our study supports an independent and immediate harmful impact on kidney function. This negative impact seems to be about 3 times greater for NSAIDs compared with an additional average drug

    SARS-CoV-2 Vaccine Alpha and Delta Variant Breakthrough Infections Are Rare and Mild but Can Happen Relatively Early after Vaccination

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    (1) Background: Some COVID-19 vaccine recipients show breakthrough infection. It remains unknown, which factors contribute to risks and severe outcomes. Our aim was to identify risk factors for SCoV2 breakthrough infections in fully vaccinated individuals. (2) Methods: We conducted a retrospective case-control study from 28 December 2020 to 25 October 2021. Data of all patients with breakthrough infection was compared to data of all vaccine recipients in the Canton of Basel-City, Switzerland. Further, breakthrough infections by Alpha- and Delta-variants were compared. (3) Results: Only 0.39% (488/126,586) of all vaccine recipients suffered from a breakthrough infection during the observational period, whereof most cases were asymptomatic or mild (97.2%). Breakthrough infections after full vaccination occurred in the median after 78 days (IQR 47-123.5). Factors with lower odds for breakthrough infection were age (OR 0.987) and previous COVID-19 infection prior to vaccination (OR 0.296). Factors with higher odds for breakthrough infection included vaccination with Pfizer/BioNTech instead of Moderna (OR 1.459), chronic disease (OR 2.109), and healthcare workers (OR 1.404). (4) Conclusions: Breakthrough infections are rare and mild but can occur early after vaccination. This implies that booster vaccination might be initiated earlier, especially for risk groups. Due to new variants emerging repeatedly, continuous monitoring of breakthrough infections is crucial
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