149 research outputs found

    Determining the Baryon Impact on the Matter Power Spectrum with Galaxy Clusters

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    The redistribution of baryonic matter in massive halos through processes like active galactic nuclei feedback and star formation leads to a suppression of the matter power spectrum on small scales. This redistribution can be measured empirically via the gas and stellar mass fractions in galaxy clusters, and leaves imprints on their electron density profiles. We constrain two semi-analytical baryon correction models with a compilation of recent Bayesian population studies of galaxy groups and clusters sampling a mass range above ∼3×1013\sim 3 \times 10^{13} M⊙M_\odot, and with cluster gas density profiles derived from deep, high-resolution X-ray observations. We are able to fit all the considered observational data, but highlight some anomalies in the observations. The constraints allow us to place precise, physically informed priors on the matter power spectrum suppression. At a scale of k=1hk=1 h Mpc−1^{-1} we find a suppression of 0.042−0.014+0.0120.042^{+0.012}_{-0.014} (0.049−0.012+0.0160.049^{+0.016}_{-0.012}), while at k=3hk=3h Mpc−1^{-1} we find 0.184−0.031+0.0260.184^{+0.026}_{-0.031} (0.179−0.020+0.0180.179^{+0.018}_{-0.020}), depending on the model used. We also predict at 97.5 percent credibility, that at scales k<0.37hk<0.37h Mpc−1^{-1} baryon feedback impacts the matter power less than 1%1\%. This puts into question if baryon feedback is the driving factor for the discrepancy between cosmic shear and primary CMB results. We independently confirm results on this suppression from small-scale cosmic shear studies, while we exclude some hydro-dynamical simulations with too strong and too weak baryonic feedback. Our empirical prediction of the power spectrum suppression shows that studies of galaxy groups and clusters will be instrumental in unlocking the cosmological constraining power of future cosmic shear experiments like \textit{Euclid} and Rubin-LSST.Comment: 14 pages, 7 figures, submitted to MNRA

    Data on ADME parameters of bisphenol A and its metabolites for use in physiologically based pharmacokinetic modelling

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    The paper presents the collection of physicochemical parameters of bisphenol A (BPA) and its sulfate (BPAS) and glucuronide (BPAG) conjugates, accompanied by data characterizing their absorption, distribution, metabolism and excretion (ADME) behavior following oral administration of BPA. The data were collected from open literature sources and publicly available databases. Additionally, data calculated by using the MarvinSketch 18.30.0 software or predicted by relevant QSAR models built in Simcyp® Simulator were also used. All data were analysed and are fit for purpose if necessary to ensure a reliable prediction of pharmacokinetics of BPA and its conjugates. The data selection process and reasoning for fitting is provided to allow critical assessment and to ensure data transparency. Finally, the sensitivity analysis was performed to assess the influence of the selected parameters on the PBPK model predictions

    Jaundice as the first symptom of HELLP syndrome – case report

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    Jaundice is a rare symptom of the HELLP syndrome (hemolysis, elevated liver enzymes, low platelet count) and is diagnosed in only 5% of the patients with this condition. However, jaundice is related with sever presentation of the disease and associated with higher mortality. The aim of this paper was to present a case of 24-year-old patient with jaundice as the first symptom of severe HELLP syndrome. A review of the literature about symptoms and treatment of HELLP syndrome and differential diagnosis of jaundice in pregnancy was done as well

    Routine cholangiography during rigid-hybrid transvaginal natural orifice transluminal endoscopic cholecystectomy

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    Background: Transvaginal rigid-hybrid transluminal endoscopic cholecystectomy (tvCCE) has become a routine procedure in some laparoscopic departments in recent years. Although intraoperative cholangiography is an important adjunct to cholecystectomy, its feasibility and safety in tvCCE have not been demonstrated to date. Methods: Patients undergoing tvCCE between April and October 2012 were included in this study. An intraoperative cholangiogram was obtained routinely for all the patients. Patient characteristics, operation data, feasibility, and duration of the cholangiography as well as the postoperative course were recorded prospectively. Results: For 32 (97%) of the 33 patients enrolled in this study, intraoperative cholangiography could be performed successfully. The median duration of cholangiography was 6min (interquartile range, 4-7min). Common bile duct stones were detected in three patients (10%). Laparoscopic bile duct revision with the aid of one additional port was successful in two of these patients. One patient needed postoperative endoscopic retrograde cholangiopancreatography due to the impossibility of extracting an impacted prepapillary concrement. One operation was converted to a four-port laparoscopic cholecystectomy. One additional port was used in 11 patients (33%) and two additional ports in three patients (9%). Three intraoperative minor complications (9%) and one postoperative minor complication (3%) occurred. Conclusions: Intraoperative cholangiography during tvCCE is feasible, safe, and easy to perform. The need for intraoperative cholangiography no longer represents a contraindication for tvCCE

    Single-nanowire, low-bandgap hot carrier solar cells with tunable open-circuit voltage

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    Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated "hot carriers" before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where the potential efficiency gain is highest. Recently, a high open-circuit voltage was demonstrated in an illuminated wurtzite InAs nanowire with a low bandgap of 0.39 eV, and was interpreted in terms of a photothermoelectric effect. Here, we point out that this device is a hot carrier solar cell and discuss its performance in those terms. In the demonstrated devices, InP heterostructures are used as energy filters in order to thermoelectrically harvest the energy of hot electrons photogenerated in InAs absorber segments. The obtained photovoltage depends on the heterostructure design of the energy filter and is therefore tunable. By using a high-resistance, thermionic barrier an open-circuit voltage is obtained that is in excess of the Shockley-Queisser limit. These results provide generalizable insight into how to realize high voltage hot carrier solar cells in low-bandgap materials, and therefore are a step towards the demonstration of higher efficiency hot carrier solar cells

    Mapping and Evaluating Marine Protected Areas and Ecosystem Services: A Transdisciplinary Delphi Forecasting Process Framework

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    Marine Protected Areas (MPAs) are an important tool for management and conservation and play an increasingly recognised role in societal and human well-being. However, the assessment of MPAs often lacks a simultaneous consideration of ecological and socio-economic outcomes, and this can lead to misconceptions on the effectiveness of MPAs. In this perspective, we present a transdisciplinary approach based on the Delphi method for mapping and evaluating Marine Protected Areas for their ability to protect biodiversity while providing Ecosystem Services (ES) and related human well-being benefits - i.e., the ecosystem outputs from which people benefit. We highlight the need to include the human dimensions of marine protection in such assessments, given that the effectiveness of MPAs over time is conditional on the social, cultural and institutional contexts in which MPAs evolve. Our approach supports Ecosystem-Based Management and highlights the importance of MPAs in achieving restoration, conservation, and sustainable development objectives in relation to EU Directives such as the Marine Strategy Framework Directive (MSFD), the Maritime Spatial Planning Directive (MSPD), and the Common Fisheries Policy (CFP)

    Morphological characterization of the human corneal epithelium by in vivo confocal laser scanning microscopy

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    Background: Regarding the growing interest and importance of understanding the cellular changes of the cornea in diseases, a quantitative cellular characterization of the epithelium is becoming increasingly important. Towards this, the latest research offers considerable improvements in imaging of the cornea by confocal laser scanning microscopy (CLSM). This study presents a pipeline to generate normative morphological data of epithelial cell layers of healthy human corneas. Methods: 3D in vivo CLSM was performed on the eyes of volunteers (n=25) with a Heidelberg Retina Tomograph II equipped with an in-house modified version of the Rostock Cornea Module implementing two dedicated piezo actuators and a concave contact cap. Image data were acquired with nearly isotropic voxel resolution. After image registration, stacks of en-face sections were used to generate full-thickness volume data sets of the epithelium. Beyond that, an image analysis algorithm quantified en-face sections of epithelial cells regarding the depth-dependent mean of cell density, area, diameter, aggregation (Clark and Evans index of aggregation), neighbor count and polygonality. Results: Imaging and cell segmentation were successfully performed in all subjects. Thereby intermediated cells were efficiently recognized by the segmentation algorithm while efficiency for superficial and basal cells was reduced. Morphological parameters showed an increased mean cell density, decreased mean cell area and mean diameter from anterior to posterior (5,197.02 to 8,190.39 cells/mm²; 160.51 to 90.29 µm²; 15.9 to 12.3 µm respectively). Aggregation gradually increased from anterior to posterior ranging from 1.45 to 1.53. Average neighbor count increased from 5.50 to a maximum of 5.66 followed by a gradual decrease to 5.45 within the normalized depth from anterior to posterior. Polygonality gradually decreased ranging from 4.93 to 4.64 sides of cells. The neighbor count and polygonality parameters exhibited profound depth-dependent changes. Conclusions: This in vivo study demonstrates the successful implementation of a CLSM-based imaging pipeline for cellular characterization of the human corneal epithelium. The dedicated hardware in combination with an adapted image registration method to correct the remaining motion-induced image distortions followed by a dedicated algorithm to calculate characteristic quantities of different epithelial cell layers enabled the generation of normative data. Further significant effort is necessary to improve the algorithm for superficial and basal cell segmentation

    Benthic-pelagic coupling in the Greenland-Norwegian Sea and its effect on the geological record

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    The sedimentation pattern of organic material in the Greenland-Norwegian Sea is reflected in the surface sediments, although less than 0.5% of the organic matter is buried in the sediment. Maximum fluxes and benthic responses are observed during June and/or August/September, following the pattern of export production in the pelagial zone. The annual remineralization rate on the Vøring Plateau is 3.0 g C m−2 a −1 Freshly settled phytodetritus, as detected by chlorophyll measurements, is rapidly mixed into the sediment and decomposed. It stimulates the activity of benthic organisms, especially foraminifera. The mixing coefficient for this material is D b=0.2 cm2 d−1, which is two to three orders of magnitude higher than that estimated from radiotracer methods. The effect on the geological record, however, is likely to be small. Chlorophyll-containing particles are at first very evenly distributed on the seafloor. After partial decomposition and resuspension, a secondary redistribution of particles occurs which can result in the formation of a high accumulation area, with an up to 80-fold increase in the sedimentation rate by lateral advection. This is mainly due to physical processes, because biodeposition mediated by benthic animals increases sedimentation by only a factor of two or three
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