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Cannabis is the most commonly used illicit drug in the world. However, because of a changing legal landscape and rising interest in therapeutic utility, there is an increasing trend in (long-term) use and possibly cannabis impairment. Importantly, a growing body of evidence suggests that regular cannabis users develop tolerance to the impairing, as well as the rewarding, effects of the drug. However, the neuroadaptations that may underlie cannabis tolerance remain unclear. Therefore, this double-blind, randomized, placebo-controlled, cross-over study assessed the acute influence of cannabis on the brain and behavioral outcomes in two distinct cannabis user groups. Twelve occasional and 12 chronic cannabis users received acute doses of cannabis (300-μg/kg delta-9-tetrahydrocannabinol) and placebo and underwent ultrahigh field functional magnetic resonance imaging and magnetic resonance spectroscopy. In occasional users, cannabis induced significant neurometabolic alterations in reward circuitry, namely, decrements in functional connectivity and increments in striatal glutamate concentrations, which were associated with increases in subjective high and decreases in performance on a sustained attention task. Such changes were absent in chronic users. The finding that cannabis altered circuitry and distorted behavior in occasional, but not chronic users, suggests reduced responsiveness of the reward circuitry to cannabis intoxication in chronic users. Taken together, the results suggest a pharmacodynamic mechanism for the development of tolerance to cannabis impairment, of which is important to understand in the context of the long-term therapeutic use of cannabis-based medications, as well as in the context of public health and safety of cannabis use when performing day-to-day operations.
Ecophysiological studies on Antarctic cryptophytes to assess whether climatic changes such as ocean acidification and enhanced stratification affect their growth in Antarctic coastal waters in the future are lacking so far. This is the first study that investigated the combined effects of increasing availability of pCO2 (400 and 1000 µatm) and irradiance (20, 200 and 500 μmol photons m−2 s −1) on growth, elemental composition and photophysiology of the Antarctic cryptophyte Geminigera cryophila. Under ambient pCO2, this species was characterized by a pronounced sensitivity to increasing irradiance with complete growth inhibition at the highest light intensity. Interestingly, when grown under high pCO2 this negative light effect vanished and it reached highest rates of growth and particulate organic carbon production at the highest irradiance compared to the other tested experimental conditions. Our results for G. cryophila reveal beneficial effects of ocean acidification in conjunction with enhanced irradiance on growth and photosynthesis. Hence, cryptophytes such as G. cryophila may be potential winners of climate change, potentially thriving better in more stratified and acidic coastal waters and contributing in higher abundance to future phytoplankton assemblages of coastal Antarctic waters.
Highlights
• The goal was to assess the intra- and inter-scanner reproducibility of qMRI data.
• Mean scan-rescan variations were not exceeding 2.14%.
• Mean inter-scanner model deviations were not exceeding 5.21%.
• Provided that identical acquisition sequences are used, discrepancies between qMRI data acquired with different scanner models are low.
Abstract
Background: Quantitative MRI (qMRI) techniques allow assessing cerebral tissue properties. However, previous studies on the accuracy of quantitative T1 and T2 mapping reported a scanner model bias of up to 10% for T1 and up to 23% for T2. Such differences would render multi-centre qMRI studies difficult and raise fundamental questions about the general precision of qMRI. A problem in previous studies was that different methods were used for qMRI parameter mapping or for measuring the transmitted radio frequency field B1 which is critical for qMRI techniques requiring corrections for B1 non-uniformities.
Aims: The goal was to assess the intra- and inter-scanner reproducibility of qMRI data at 3 T, using two different scanner models from the same vendor with exactly the same multiparametric acquisition protocol.
Methods: Proton density (PD), T1, T2* and T2 mapping was performed on healthy subjects and on a phantom, performing each measurement twice for each of two scanner models. Although the scanners had different hardware and software versions, identical imaging sequences were used for PD, T1 and T2* mapping, adapting the codes of an existing protocol on the older system line by line to match the software version of the newer scanner. For T2-mapping, the respective manufacturer’s sequence was used which depended on the software version. However, system-dependent corrections were carried out in this case. Reproducibility was assessed by average values in regions of interest.
Results: Mean scan-rescan variations were not exceeding 2.14%, with average values of 1.23% and 1.56% for the new and old system, respectively. Inter-scanner model deviations were not exceeding 5.21% with average values of about 2.2–3.8% for PD, 2.5–3.0% for T2*, 1.6–3.1% for T1 and 3.3–5.2% for T2.
Conclusions: Provided that identical acquisition sequences are used, discrepancies between qMRI data acquired with different scanner models are low. The level of systematic differences reported in this work may help to interpret multi-centre data.
Objective: Randomized trials have shown that concomitant methotrexate (MTX) augments the effectiveness of tumour necrosis factor (TNF) inhibitors in rheumatoid arthritis (RA), but its benefit in psoriatic arthritis (PsA) has not been demonstrated. The goal of this study was to examine whether the impact of concomitant MTX on therapeutic outcomes in patients with PsA was similar to its effects in RA.
Methods: We used data from highly comparable and concurrent observational studies of patients with PsA (N = 1424) or RA (N = 3148) who initiated adalimumab therapy during routine clinical care. The 28-joint Disease Activity Score (DAS28) and patient-reported pain scores were evaluated in patients who received 24 months of continuous treatment with adalimumab monotherapy or adalimumab + MTX and in patients who initiated or stopped concomitant MTX during ongoing adalimumab therapy.
Results: Twenty-four months of continuous treatment with adalimumab + MTX was superior to adalimumab monotherapy in RA patients, while no significant difference was observed in patients with PsA. RA patients who added MTX during the study showed significant individual improvements in DAS28 and pain scores at 6 months after the change in therapy, while those who removed MTX had slight increases in disease activity. In contrast, in patients with PsA, neither initiation nor removal of MTX during continuous adalimumab therapy had a significant effect on therapeutic outcomes.
Conclusion: Addition of MTX to adalimumab confers further therapeutic benefit in patients with RA, but not in those with PsA, suggesting differences in MTX effects in these two patient populations.
Clinicaltrials.gov NCT01078090, NCT01077258, NCT01111240
In fungi, the mitochondrial respiratory chain complexes (complexes I–IV) are responsible for oxidative phosphorylation, as in higher eukaryotes. Cryo-EM was used to identify a 200 kDa membrane protein from Neurospora crassa in lipid nanodiscs as cytochrome c oxidase (complex IV) and its structure was determined at 5.5 Å resolution. The map closely resembles the cryo-EM structure of complex IV from Saccharomyces cerevisiae. Its ten subunits are conserved in S. cerevisiae and Bos taurus, but other transmembrane subunits are missing. The different structure of the Cox5a subunit is typical for fungal complex IV and may affect the interaction with complex III in a respiratory supercomplex. Additional density was found between the matrix domains of the Cox4 and Cox5a subunits that appears to be specific to N. crassa.
Highlights
• This current review covers studies that have identified long non-coding RNAs in aortic aneurysm development and progression.
• We separately discuss transcripts and mechanisms of importance to thoracic as well as abdominal aortic aneurysms.
• Functional data on lncRNAs being identified are highlighted.
• Some have been studied in human as well as experimental models of the disease pathology.
Abstract
Aortic aneurysm (AA) is a complex and dangerous vascular disease, featuring progressive and irreversible vessel dilatation. AA is typically detected either by screening, or identified incidentally through imaging studies. To date, no effective pharmacological therapies have been identified for clinical AA management, and either endovascular repair or open surgery remains the only option capable of preventing aneurysm rupture. In recent years, multiple research groups have endeavored to both identify noncoding RNAs and to clarify their function in vascular diseases, including aneurysmal pathologies. Notably, the molecular roles of noncoding RNAs in AA development appear to vary significantly between thoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs). Some microRNAs (miRNA - a non-coding RNA subspecies) appear to contribute to AA pathophysiology, with some showing major potential for use as biomarkers or as therapeutic targets. Studies of long noncoding RNAs (lncRNAs) are more limited, and their specific contributions to disease development and progression largely remain unexplored. This review aims to summarize and discuss the most current data on lncRNAs and their mediation of AA pathophysiology.
Background. Atherothrombotic disease, including coronary artery disease (CAD) and peripheral artery disease (PAD), can lead to cardiovascular (CV) events, such as myocardial infarction, stroke, limb ischemia, heart failure, and CV death. Aim. Evaluate the humanistic and economic burden of CAD and PAD and identify unmet needs through a comprehensive literature review. Methods. Relevant search terms were applied across online publication databases. Studies published between January 2010 and August 2017 meeting the inclusion/exclusion criteria were selected; guidelines were also included. Two rounds of screening were applied to select studies of relevance. Results. Worldwide data showed approximately 5–8% prevalence of CAD and 10–20% prevalence of PAD, dependent on the study design, average age, gender, and geographical location. Data from the REACH registry indicated that 18–35% of patients with CAD and 46–68% of patients with PAD had disease in one or more vascular beds. Use of medication to control modifiable CV risk factors was variable by country (lower in France than in Canada); statins and aspirin were the most widely used therapies in patients with chronic disease. Survival rates have improved with medical advancements, but there is an additional need to improve the humanistic burden of disease (i.e., associated disability and quality of life). The economic burden of atherothrombotic disease is high and expected to increase with increased survival and the aging population. Conclusion. CAD and PAD represent a substantial humanistic and economic burden worldwide, highlighting a need for new interventions to reduce the incidence of atherothrombotic disease.
Highlights
• Subcrustal earthquakes detected beneath Fogo volcano, Cape Verde.
• At the focal depth of 40 km temperatures are likely too high for brittle failure.
• The earthquakes may originate from magma injection into a deep subcrustal reservoir.
• This observation indicates a distinct magma supply system of Fogo volcano.
Abstract
Fogo volcano belongs to the Cape Verde hotspot and its most recent eruption occurred from November 2014 to February 2015. From January to December 2016 we operated a temporary seismic network and array on Fogo and were able to locate 289 earthquakes in total. Array analysis shows that most of the events occur within the crust at distances >25 km near the neighboring island of Brava. However, on 15th August 2016 the network recorded an isolated cluster of >20 earthquakes, 13 of which could be located beneath the southern part of Fogo. The differences between S- and P-wave arrival times at steep incidence clearly indicate focal depths between approximately 38 and 44 km whereas receiver-function analyses place the Moho discontinuity at depths between 11 and 14 km. Thus, the earthquakes are located well within the upper mantle directly beneath Fogo. In view of the elevated upper-mantle temperatures within a hotspot regime, we propose that fracturing induced by magmatic injection is the most likely cause for the observed deep earthquakes.
The current problem of increasing antibiotic resistance and the resurgence of numerous infections indicate the need for novel vaccination strategies more than ever. In vaccine development, the search for and the selection of adequate vaccine antigens is the first important step. In recent years, bacterial outer membrane proteins have become of major interest, as they are the main proteins interacting with the extracellular environment. Trimeric autotransporter adhesins (TAAs) are important virulence factors in many Gram-negative bacteria, are localised on the bacterial surface, and mediate the first adherence to host cells in the course of infection. One example is the Neisseria adhesin A (NadA), which is currently used as a subunit in a licensed vaccine against Neisseria meningitidis. Other TAAs that seem promising vaccine candidates are the Acinetobacter trimeric autotransporter (Ata), the Haemophilus influenzae adhesin (Hia), and TAAs of the genus Bartonella. Here, we review the suitability of various TAAs as vaccine candidates.
The capacity of pathogenic microorganisms to adhere to host cells and avoid clearance by the host immune system is the initial and most decisive step leading to infections. Bacteria have developed different strategies to attach to diverse host surface structures. One important strategy is the adhesion to extracellular matrix (ECM) proteins (e.g., collagen, fibronectin, laminin) that are highly abundant in connective tissue and basement membranes. Gram-negative bacteria express variable outer membrane proteins (adhesins) to attach to the host and to initiate the process of infection. Understanding the underlying molecular mechanisms of bacterial adhesion is a prerequisite for targeting this interaction by “anti-ligands” to prevent colonization or infection of the host. Future development of such “anti-ligands” (specifically interfering with bacteria-host matrix interactions) might result in the development of a new class of anti-infective drugs for the therapy of infections caused by multidrug-resistant Gram-negative bacteria. This review summarizes our current knowledge about the manifold interactions of adhesins expressed by Gram-negative bacteria with ECM proteins and the use of this information for the generation of novel therapeutic antivirulence strategies.
Gradient-consistent enrichment of finite element spaces for the DNS of fluid-particle interaction
(2019)
Highlights
• Monolithic scheme for particulate flows preventing an oscillating pressure along the interface.
• The choice of enriching shape functions is driven by the properties of its gradient instead of its value.
• The choice of enriching shape functions inherits a natural stabilization on small cut elements.
Abstract
We present gradient-consistent enriched finite element spaces for the simulation of free particles in a fluid. This involves forces being exchanged between the particles and the fluid at the interface. In an earlier work [23] we derived a monolithic scheme which includes the interaction forces into the Navier-Stokes equations by means of a fictitious domain like strategy. Due to an inexact approximation of the interface oscillations of the pressure along the interface were observed. In multiphase flows oscillations and spurious velocities are a common issue. The surface force term yields a jump in the pressure and therefore the oscillations are usually resolved by extending the spaces on cut elements in order to resolve the discontinuity. For the construction of the enriched spaces proposed in this paper we exploit the Petrov-Galerkin formulation of the vertex-centered finite volume method (PG-FVM), as already investigated in [23]. From the perspective of the finite volume scheme we argue that wrong discrete normal directions at the interface are the origin of the oscillations. The new perspective of normal vectors suggests to look at gradients rather than values of the enriching shape functions. The crucial parameter of the enrichment functions therefore is the gradient of the shape functions and especially the one of the test space. The distinguishing feature of our construction therefore is an enrichment that is based on the choice of shape functions with consistent gradients. These derivations finally yield a fitted scheme for the immersed interface. We further propose a strategy ensuring a well-conditioned system independent of the location of the interface. The enriched spaces can be used within any existing finite element discretization for the Navier-Stokes equation. Our numerical tests were conducted using the PG-FVM. We demonstrate that the enriched spaces are able to eliminate the oscillations.
Rotational test spaces for a fully-implicit FVM and FEM for the DNS of fluid-particle interaction
(2019)
The paper presents a fully-implicit and stable finite element and finite volume scheme for the simulation of freely moving particles in a fluid. The developed method is based on the Petrov-Galerkin formulation of a vertex-centered finite volume method (PG-FVM) on unstructured grids. Appropriate extension of the ansatz and test spaces lead to a formulation comparable to a fictitious domain formulation. The purpose of this work is to introduce a new concept of numerical modeling reducing the mathematical overhead which many other methods require. It exploits the identification of the PG-FVM with a corresponding finite element bilinear form. The surface integrals of the finite volume scheme enable a natural incorporation of the interface forces purely based on the original bilinear operator for the fluid. As a result, there is no need to expand the system of equations to a saddle-point problem. Like for fictitious domain methods the extended scheme treats the particles as rigid parts of the fluid. The distinguishing feature compared to most existing fictitious domain methods is that there is no need for an additional Lagrange multiplier or other artificial external forces for the fluid-solid coupling. Consequently, only one single solve for the derived linear system for the fluid together with the particles is necessary and the proposed method does not require any fractional time stepping scheme to balance the interaction forces between fluid and particles. For the linear Stokes problem we will prove the stability of both schemes. Moreover, for the stationary case the conservation of mass and momentum is not violated by the extended scheme, i.e. conservativity is accomplished within the range of the underlying, unconstrained discretization scheme. The scheme is applicable for problems in two and three dimensions.
Critical spin liquid versus valence-bond glass in a triangular-lattice organic antiferromagnet
(2019)
In the quest for materials with unconventional quantum phases, the organic triangular-lattice antiferromagnet κ-(ET)2Cu2(CN)3 has been extensively discussed as a quantum spin liquid (QSL) candidate. The description of its low temperature properties has become, however, a particularly challenging task. Recently, an intriguing quantum critical behaviour was suggested from low-temperature magnetic torque experiments. Here we highlight significant deviations of the experimental observations from a quantum critical scenario by performing a microscopic analysis of all anisotropic contributions, including Dzyaloshinskii–Moriya and multi-spin scalar chiral interactions. Instead, we show that disorder-induced spin defects provide a comprehensive explanation of the low-temperature properties. These spins are attributed to valence bond defects that emerge spontaneously as the QSL enters a valence-bond glass phase at low temperature. This theoretical treatment is applicable to a general class of frustrated magnetic systems and has important implications for the interpretation of magnetic torque, nuclear magnetic resonance, thermal transport and thermodynamic experiments.
Das Zusammenleben von Juden und Christen war in vielen deutschen Territorien, insbesondere in ländlichen Gebieten, viel enger, als man dies heute zumeist annimmt. Dafür finden sich auch in der Landgrafschaft Hessen-Kassel zahlreiche Belege. Hier soll das kirchliche Verwaltungsschrifttum zum Sprechen gebracht werden, das in Zusammenhang mit den Kasseler Superintendenten Paul Stein und Theophil Neuberger sowie dem Eschweger Superintendenten Johannes Hütterodt steht. Als Ausgangspunkt dienen insbesondere ihre Diensttagebücher.
Over the last decade, cases of metabolic syndrome and type II diabetes have increased exponentially. Exercise and ω-3 polyunsaturated fatty acid (PUFA)-enriched diets are usually prescribed but no therapy is effectively able to restore the impaired glucose metabolism, hypertension, and atherogenic dyslipidemia encountered by diabetic patients. PUFAs are metabolized by different enzymes into bioactive metabolites with anti- or pro-inflammatory activity. One important class of PUFA metabolizing enzymes are the cytochrome P450 (CYP) enzymes that can generate a series of bioactive products, many of which have been attributed protective/anti-inflammatory and insulin-sensitizing effects in animal models. PUFA epoxides are, however, further metabolized by the soluble epoxide hydrolase (sEH) to fatty acid diols. The biological actions of the latter are less well understood but while low concentrations may be biologically important, higher concentrations of diols derived from linoleic acid and docosahexaenoic acid have been linked with inflammation. One potential application for sEH inhibitors is in the treatment of diabetic retinopathy where sEH expression and activity is elevated as are levels of a diol of docosahexaenoic acid that can induce the destabilization of the retina vasculature.
Much of the research on Na+/H+ exchange has been done in prokaryotic models, mainly on the NhaA Na+/H+-exchanger from Escherichia coli (EcNhaA). Two conserved aspartate residues, Asp-163 and Asp-164, are essential for transport and are candidates for possible binding sites for the two H+ that are exchanged for one Na+ to make the overall transport process electrogenic. More recently, a proposed mechanism of transport for EcNhaA has suggested direct binding of one of the transported H+ to the conserved Lys-300 residue, a salt bridge partner of Asp-163. This contention is supported by a study reporting that substitution of the equivalent residue, Lys-305, of a related Na+/H+ antiporter, NapA from Thermus thermophilus, renders the transporter electroneutral. In this work, we sought to establish whether the Lys-300 residue and its partner Asp-163 are essential for the electrogenicity of EcNhaA. To that end, we replaced Lys-300 with Gln, either alone or together with the simultaneous substitution of Asp-163 with Asn, and characterized these transporter variants in electrophysiological experiments combined with H+ transport measurements and stability analysis. We found that K300Q EcNhaA can still support electrogenic Na+/H+ antiport in EcNhaA, but has reduced thermal stability. A parallel electrophysiological investigation of the K305Q variant of TtNapA revealed that it is also electrogenic. Furthermore, replacement of both salt bridge partners in the ion-binding site of EcNhaA produced an electrogenic variant (D163N/K300Q). Our findings indicate that alternative mechanisms sustain EcNhaA activity in the absence of canonical ion-binding residues and that the conserved lysines confer structural stability.
Previous calculations of the shear viscosity to entropy density ratio in the hadron gas have failed to reach a consensus, with η/s predictions differing by almost an order of magnitude. This work addresses and solves this discrepancy by providing an independent extraction of η/s using the newly-developed SMASH (Simulating Many Accelerated Strongly-interacting Hadrons) transport code and the Green-Kubo formalism. We compare the results from SMASH with numerical solutions of the Boltzmann equation for various systems using the Chapman-Enskog expansion as well as previous results in the literature. Substantial deviations of the coefficient are found between transport approaches mainly based on resonance propagation with finite lifetime (such as SMASH) and other (semi-analytical) approaches with energy-dependent cross-sections, where interactions do not introduce a timescale other than the inverse scattering rate. Our conclusion is that long- lived resonances strongly affect the transport properties of the system, resulting in significant differences in η/s with respect to other approaches where binary collisions dominate. We argue that the relaxation time of the system —which characterizes the shear viscosity— is determined by the interplay between the mean- free time and the lifetime of resonances. We finally show how an artificial shortening of the resonance lifetimes or the addition of a background elastic cross section nicely interpolate between the two discrepant results.
We present an analysis of the anisotropic flow harmonics in Pb+Pb collisions at beam momenta of 30A GeV/c collected by the NA61/SHINE experiment in the year 2016. Directed and elliptic flow coefficients are measured relative to the spectator plane estimated with the Projectile Spectators Detector (PSD). The flow coefficients are reported as a function of transverse momentum in different classes of collision centrality. The results are compared with a new analysis of the NA49 data for Pb+Pb collisions at 40A GeV using forward calorimeters (VCal and RCal) for event plane estimation.
The relativistic method of moments is one of the most successful approaches to extract second order viscous hydrodynamics from a kinetic underlying background. The equations can be systematically improved to higher order, and they have already shown a fast convergence to the kinetic results. In order to generalize the method we introduced long range effects in the form of effective (medium dependent) masses and gauge (coherent) fields. The most straightforward generalization of the hydrodynamic expansion is problematic at higher order. Instead of introducing an additional set of approximations, we propose to rewrite the series in terms of moments resumming the contributions of infinite non-hydrodynamics modes. The resulting equations are are consistent with hydrodynamics and well defined at all order. We tested the new approximation against the exact solutions of the Maxwell-Boltzmann-Vlasov equations in (0 + 1)-dimensions, finding a fast and stable convergence to the exact results.
The cross section of jets reconstructed from charged particles is measured in the transverse momentum range of 5<pT<100 GeV/c in pp collisions at the center-of-mass energy of s√=5.02 TeV with the ALICE detector. The jets are reconstructed using the anti-kT algorithm with resolution parameters R=0.2, 0.3, 0.4, and 0.6 in the pseudorapidity range |η|<0.9−R. The charged jet cross sections are compared with the leading order (LO) and to next-to-leading order (NLO) perturbative Quantum ChromoDynamics (pQCD) calculations. It was found that the NLO calculations agree better with the measurements. The cross section ratios for different resolution parameters were also measured. These ratios increase from low pT to high pT and saturate at high pT, indicating that jet collimation is larger at high pT than at low pT. These results provide a precision test of pQCD predictions and serve as a baseline for the measurement in Pb−Pb collisions at the same energy to quantify the effects of the hot and dense medium created in heavy-ion collisions at the LHC.
The production yield of the Λ(1520) baryon resonance is measured at mid-rapidity in Pb-Pb collisions at sNN−−−√ = 2.76 TeV with the ALICE detector at the LHC. The measurement is performed in the Λ(1520)→pK− (and charge conjugate) hadronic decay channel as a function of the transverse momentum (pT) and collision centrality. The pT-integrated production rate of Λ(1520) relative to Λ in central collisions is suppressed by about a factor of 2 with respect to peripheral collisions. This is the first observation of the suppression of a baryonic resonance at the LHC and the first 3σ evidence of Λ(1520) suppression within a single collision system. The measured Λ(1520)/Λ ratio in central collisions is smaller than the value predicted by the statistical hadronisation model calculations. The shape of the measured pT distribution and the centrality dependence of the suppression are reproduced by the EPOS3 Monte Carlo event generator. The measurement adds further support to the formation of a dense hadronic phase in the final stages of the evolution of the fireball created in heavy-ion collisions, lasting long enough to cause a significant reduction in the observable yield of short-lived resonances.
We report the differential charged jet cross section and jet fragmentation distributions measured with the ALICE detector in proton-proton collisions at a centre-of-mass energy s√= 7 TeV. Jets with pseudo-rapidity |η|<0.5 are reconstructed from charged particles using the anti-kT jet finding algorithm with a resolution parameter R = 0.4. The jet cross section is measured in the transverse momentum interval 5 ≤pchjetT< 100 GeV/c. Jet fragmentation is studied measuring the scaled transverse momentum spectra of the charged constituents of jets in four intervals of jet transverse momentum between 5 GeV/c and 30 GeV/c. The measurements are compared to calculations from the PYTHIA model as well as next-to-leading order perturbative QCD calculations with POWHEG + PYTHIA8. The charged jet cross section is described by POWHEG for the entire measured range of pchjetT. For pchjetT > 40 GeV/c, the PYTHIA calculations also agree with the measured charged jet cross section. PYTHIA6 simulations describe the fragmentation distributions to 15%. Larger discrepancies are observed for PYTHIA8.
The first measurement of dielectron (e+e−) production in central (0−10%) Pb-Pb collisions at sNN−−−√ = 2.76 TeV at the LHC is presented. The dielectron invariant-mass spectrum is compared to the expected contributions from hadron decays in the invariant-mass range 0<mee<3.5 GeV/c2. The ratio of data and the cocktail of hadronic contributions without vacuum ρ0 is measured in the invariant-mass range 0.15<mee<0.7 GeV/c2, where an excess of dielectrons is observed in other experiments, and its value is 1.40±0.28 (stat.)±0.08 (syst.)±0.27 (cocktail). The dielectron spectrum measured in the invariant mass range 0<mee<1 GeV/c2 is consistent with the predictions from two theoretical model calculations that include thermal dielectron production from both partonic and hadronic phases with in-medium broadened ρ0 meson. The fraction of direct virtual photons over inclusive virtual photons is extracted for dielectron pairs with invariant mass 0.1<mee<0.3 GeV/c2, and in the transverse-momentum intervals 1<pT,ee<2 GeV/c and 2<pT,ee<4 GeV/c. The measured fraction of virtual direct photons is consistent with the measurement of real direct photons by ALICE and with the expectations from previous dielectron measurements at RHIC within the experimental uncertainties.
The correlations of identical charged kaons were measured in p-Pb collisions at sNN−−−√=5.02 TeV by the ALICE experiment at the LHC. The femtoscopic invariant radii and correlation strengths were extracted from one-dimensional kaon correlation functions and were compared with those obtained in pp and Pb-Pb collisions at s√=7 TeV and sNN−−−√=2.76 TeV, respectively. The presented results also complement the identical-pion femtoscopic data published by the ALICE collaboration. The extracted radii increase with increasing charged-particle multiplicity and decrease with increasing pair transverse momentum. At comparable multiplicities, the radii measured in p-Pb collisions are found to be close to those observed in pp collisions. The obtained femtoscopic parameters are reproduced by the EPOS 3 hadronic interaction model and disfavor models with large initial size or strong collective expansion at low multiplicities.
Comprehensive results on the production of unidentified charged particles, π±, K±, K0S, K*(892)0, p, p¯¯¯, ϕ(1020), Λ, Λ¯¯¯¯, Ξ−, Ξ¯¯¯¯+, Ω− and Ω¯¯¯¯+ hadrons in proton-proton (pp) collisions at s√ = 7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid auto-correlation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle to pion ratios are shown to depend solely on charged-particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at LHC energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions.
We present measurements of two-particle differential number correlation functions R2 and transverse momentum correlation functions P2, obtained from p-Pb collisions at 5.02 TeV and Pb-Pb collisions at 2.76 TeV. The results are obtained using charged particles in the pseudorapidity range |η|< 1.0, and transverse momentum range 0.2<pT<2.0 GeV/c as a function of pair separation in pseudorapidity, |Δη|, azimuthal angle, Δφ, and for several charged-particle multiplicity classes. Measurements are carried out for like-sign and unlike-sign charged-particle pairs separately and combined to obtain charge-independent and charge-dependent correlation functions. We study the evolution of the width of the near-side peak of these correlation functions with collision centrality. Additionally, we study Fourier decompositions of the correlators in Δφ as a function of the pair separation |Δη|. Significant differences in the dependence of their harmonic coefficients on multiplicity classes are found. These differences can be exploited, in theoretical models, to obtain further insight into charged-particle production and transport in heavy-ion collisions. Moreover, an upper limit of non-flow contributions to flow coefficients vn measured in Pb-Pb collisions based on the relative strength of Fourier coefficients measured in p-Pb interactions is estimated.
Angular correlations between heavy-flavour decay electrons and charged particles at mid-rapidity (|η|<0.8) are measured in p-Pb collisions at sNN−−−√ = 5.02 TeV. The analysis is carried out for the 0-20% (high) and 60-100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavour hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v2) for heavy-flavour decay electrons in the transverse momentum interval 1.5<pT<4 GeV/c in high-multiplicity events, with a significance larger than 5σ. The results are compared with those of charged particles at mid-rapidity and of inclusive muons at forward rapidity. The v2 measurement of open heavy-flavour particles at mid-rapidity in small collision systems could provide crucial information to help interpret the anisotropies observed in such systems.
Measurements of inclusive and direct photon production at mid-rapidity in pp collisions at s√=2.76 and 8 TeV are presented by the ALICE experiment at the LHC. The results are reported in transverse momentum ranges of 0.4<pT<10 GeV/c and 0.3<pT<16 GeV/c, respectively. Photons are detected with the electromagnetic calorimeter~(EMCal) and via reconstruction of e+e− pairs from conversions in the ALICE detector material using the central tracking system. For the final measurement of the inclusive photon spectra the results are combined in the overlapping pT interval of both methods. Direct photon spectra, or their upper limits at 90% C.L. are extracted using the direct photon excess ratio Rγ, which quantifies the ratio of inclusive photons over decay photons generated with a decay-photon simulation. An additional hybrid method, combining photons reconstructed from conversions with those identified in the EMCal, is used for the combination of the direct photon excess ratio Rγ, as well as the extraction of direct photon spectra or their upper limits. While no significant signal of direct photons is seen over the full pT range, Rγ for pT>7 GeV/c is at least one σ above unity and consistent with expectations from next-to-leading order pQCD calculations.
Measurements of anisotropic flow coefficients (vn) and their cross-correlations using two- and multi-particle cumulant methods are reported in collisions of pp at s√=13 TeV, p-Pb at sNN−−−√=5.02 TeV, Xe-Xe at sNN−−−√=5.44 TeV, and Pb-Pb at sNN−−−√=5.02 TeV recorded with the ALICE detector. These measurements are performed as a function of multiplicity in the mid-rapidity region |η|<0.8 for the transverse momentum range 0.2<pT<3.0 GeV/c. An ordering of the coefficients v2>v3>v4 is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v2 multiplicity dependence is observed relative to nucleus--nucleus collisions in the same multiplicity range. Using the novel subevent method, v2 measured in pp and p-Pb collisions with four-particle cumulants is found to be compatible with that from six-particle cumulants. The symmetric cumulants SC(m,n) calculated with the subevent method which evaluate the correlation strength between v2n and v2m are also presented. The presented data, which add further support to the existence of long-range multi-particle azimuthal correlations in high multiplicity pp and p-Pb collisions, can neither be described by PYTHIA8 nor by IP-Glasma+MUSIC+UrQMD model calculations, and hence provide new insights into the understanding of collective effects in small collision systems.
Dieser Aufsatz untersucht die Frage, welche Rolle die verdeckte Kopräsenz visueller Medien in Rhys' Roman bei der zunehmenden Desorientierung und De-plazierung der Hauptfigur spielt. Mithin nimmt sich dieser Aufsatz vor zu zeigen, wie mediale Spannungsfelder zwischen Text und Bild in "Wide Sargasso Sea" die Grenzen aufrührerischer und dazwischen liegender Existenzen reflektieren. Konkret erzeugt der Roman eine Innen- und Außensicht von Antoinettes Metamorphose. Rhys' medienreflexive Verfahren in "Wide Sargasso Sea", so lautet die These, versinnbildlichen Antoinettes leiblichen Zerfall. Obwohl verbale Texte eigentlich die Wesenseigenschaft des Leibs nicht fassen können, vermag "Wide Sargasso Sea" mit Hilfe von verdeckter Intermedialität (von Bild und Wort) in der wechselnd homodiegetischen Erzählung das leibliche Erleben Antoinettes in der Form ihres zunehmenden Wahrnehmungs- und Sichtbarkeitsverlusts zu evozieren. Das Spannungsverhältnis von Bild und Wort im Roman legt den Leserinnen und Lesern im Zuge dieser ästhetischen Psychologisierung eine stete Weiterdifferenzierung nahe, welche Ambiguität vor Eindeutigkeit und Dissens vor Konsens setzt.
Vermutlich in den ersten Monaten des Jahres 1817 besucht der englische Dichter John Keats zusammen mit dem Freund und ebenso selbstbewussten wie streitbaren Historienmaler Benjamin Robert Haydon das British Museum und verfasst im Anschluss daran tief beeindruckt zwei Sonette, die seiner Reaktion auf das Erlebte Ausdruck geben. [...] Der erste der beiden Texte gilt als exemplarisch für das, was man die 'zweite Generation' der englischen Romantiker nennt. Während die Texte der ersten Generation mit Wordsworth und Coleridge weithin einlösen, was deren 'Preface' programmatisch als expressiv ausgerichtete sprachliche Umsetzung eines "spontaneous overflow of powerful feelings" samt damit zu erzielender "emotion recollected in tranquillity" bezeichnet und sich mit am paradigmatischsten in Wordsworths bekanntem "Daffodils"-Gedicht als Koppelung der Deskription einer unerwarteten einmaligen Naturerfahrung mit dem Kommentar einer auf Dauer gestellten imaginationsgeleiteten Wiederholungsmöglichkeit ebendieser Erfahrung ausgeführt findet, sieht man die Texte der zweiten Generation von Keats und Shelley vorzugsweise eher als, wenn auch heterogene, so doch kontinuierliche Fortführung des romantisch-expressiven Projekts mit einerseits verstärkt ästhetisierendem und andererseits deutlicher politisierendem Einschlag. Ich will im Folgenden zunächst in einem ersten Schritt einer solchen noch weitgehend mimetisch an der abbildenden Darstellung von Objekten orientierten Lektüre nachgehen, bevor ich sodann in einem sich daran anschließenden zweiten Schritt den Versuch unternehme, Keats' Sonett in einer intermedial und medienkomparatistisch an der Textperformanz ausgerichteten Lektüre als ein Beispiel dafür zu lesen, dass sich erstaunlich früh schon im 19. Jahrhundert eine Tendenz abzuzeichnen beginnt, die man gewissermaßen als zukunftsweisenden Ausbruch aus der Mimesis bezeichnen kann.
Als Big Edie 1977 unmittelbar vor ihrem Tod von ihrer Tochter gefragt wurde, ob sie noch irgendetwas sagen oder richtigstellen wolle, antwortete die Sterbende: "There's nothing more to say. It's all in the film." Diesen in der Diskussion um Grey Gardens viel zitierten Worten möchte ich im vorliegenden Beitrag nachgehen und den Film dabei als ein kinematografisches Doppelporträt begreifen, das, wie es Jean-Luc Nancy zufolge für die Bildform Porträt generell typisch, wenn nicht gar konstitutiv ist, "vor allem die Spannung einer Beziehung [präsentiert]." In diesem Zusammenhang wird mich allerdings weder die Spannung zwischen den Porträtierten, also der Mutter-Tochter-Dualismus, noch die zwischen den Porträtierten und den Porträtierenden, also den Maysles, sonderlich interessieren, sondern vielmehr die zwischen dem Porträt, das heißt dem Film, und anderen Porträts - und zwar jenen, die der Film in seinem, wenn man so will, bis zum Bersten gefüllten intermedialen Laderaum mit sich führt. Was sich rasch zeigen wird, ließe sich unter Rekurs auf Pierre Bourdieus Ausführungen zur männlichen Herrschaft wie folgt formulieren: Grey Gardens ist auch und vor allem ein in vielerlei Hinsicht heterodoxes Antiporträt, das gegenüber Bildwerken in Stellung gebracht wird, die der androzentrischen Doxa voll und ganz entsprechen.
Wer die sogenannte Höhenkammliteratur auf die Schlüsselwörter 'Geld' (inkl. verwandter Begriffe wie Taler, Kreuzer, Schulden, Zins, Schatz etc.) und 'Medium / Medien' abtastet, muss mit Überraschungen rechnen. [...] Eigenartig ist es, dass weder früher noch heute, also in Zeiten der Hochkonjunktur von 'Medien', die Begriffe 'Geld' und 'Medium' eng aneinander gekoppelt sind. Wendungen wie 'das Medium Geld' wird man in der deutschsprachigen Literatur der letzten Jahrhunderte nicht finden. Geld wird auch in gängigen Einführungen in Medienwissenschaft und Medientheorien nur selten ausdrücklich als Medium wahrgenommen und thematisiert - und dies, obwohl einflussreiche Theoretiker wie Georg Simmel, Marshal McLuhan und Niklas Luhmann Geld ausdrücklich und mit guten Gründen als mächtiges Medium verstanden haben. Dabei ist schon auf der phänomenologischen Ebene unverkennbar, dass Geld und Medien engstens aufeinander angewiesen sind. Geld muss medial erscheinen, um seine Geltung zu entfalten. Es funktioniert nur, wenn es beglaubigt wird, und muss sich dennoch oder deshalb systematische Zweifel an seiner Glaubwürdigkeit gefallen lassen - wie andere Medien auch.
Die Bewegung aus dem Stillstand ist für die Kunst seit Sandro Botticelli (1445-1510) signifikant. Ein berühmtes Beispiel ist das Gemälde 'Nascita di Venere'/'Geburt der Venus' (1486). Aus der Haardarstellung der Venus - den Wendungen, Knoten, Flammen und Schlangen der Haare, die sich dynamisch mal in die eine, mal in die andere Richtung bewegen - spricht offensichtlich eine Animalisierung, aber auch eine Erotisierung der Haarbewegung, die zu einer Belebung des visuellen Ausdrucks führt. Aus der Polarität von Spannung und Ruhe schöpfen die Gemäldefiguren die Intensität ihrer Gebärdensprache. Auch der deutsche Kunsthistoriker Aby Warburg (1866-1929) fühlt sich in seiner Dissertation über Sandro Botticellis 'Geburt der Venus' und 'Frühling' (1893) durch das Gemälde Botticellis mehr vom Fließen und Wehen als vom Statischen und Nackten animiert und kristallisiert so die Theorie der von 'kinesis' und 'stasis' zeugenden Pathosformel heraus, wie im Folgenden erläutert wird. Einen Vorschlag dazu, wie diese Theorie auf die künstlerischen Produkte, namentlich Photographien des 20. Jahrhunderts angewandt werden kann, ist das Hauptanliegen dieses Aufsatzes.
In der ökokritischen Literatur- und Kulturwissenschaft wird zunehmend der Ruf nach einer intensiveren Methodenreflexion laut. Neben den künstlerischen und literarischen Darstellungsweisen rückt dabei in jüngster Zeit auch der Gesichtspunkt der Medialität verstärkt in den Blick. [...] In dem Maße, in dem der Modus der Darstellung bzw. das Wie der Gestaltung in der ökologischen Kulturwissenschaft gegenüber den jeweiligen politischen, naturwissenschaftlichen oder soziokulturellen Inhalten in den Vordergrund rücken, tritt auch die zentrale Bedeutung der Medien innerhalb einer komparatistischen Ökokritik deutlich zu Tage ebenso wie die Notwendigkeit der betreffenden Forschungsrichtung, die Medialität ihrer Gegenstände vermehrt zu berücksichtigen. Eine solche Medienreflexion kann auf verschiedenen Ebenen ansetzen und eröffnet ein weites Feld von lohnenden Fragerichtungen. Zu dem Spektrum einer derartigen Medienreflexion gehört unter anderem die im Folgenden näher zu diskutierende Frage, inwieweit sich im Blick auf die Mensch-Tier-Beziehung seit dem 19. Jahrhundert ein Medienwandel abzeichnet, insbesondere in Hinblick auf die wissenschaftliche Beobachtung und die Zurschaustellung von Tieren in den eigens dafür geschaffenen Kulturräumen des naturhistorischen Museums und des Zoologischen Gartens. [...] Es ist dabei wichtig, auch die Räume selbst und ihre jeweilige Architektur nicht allein als bloße Umgebungen oder Rahmungen zu betrachten, sondern als Medien sui generis zu begreifen und zu erkennen, dass sie bestimmte soziale und kommunikative Funktionen erfüllen. [...] Es wird daher unter anderem zu zeigen sein, inwiefern die naturhistorischen Museen und die Zoologischen Gärten solche räumlichen und medialen Beziehungsfelder aufweisen und inwieweit sie diese mit spezifischen symbolischen Bedeutungen überlagern.
Bilder werden zumeist begriffen als erstens zweidimensional, flächig und in der Fläche durch ihren Rahmen begrenzt, und zweitens als ruhend, unveränderlich und unbewegt. [...] Bislang kaum entfaltet dagegen ist die - weder Bergson noch Deleuze besonders interessierende - Raumqualität der Bilder. Bilder werden weithin mit Zweidimensionalität verbunden. Auch räumliche Arrangements - Gegebenheiten oder Artefakte - jedoch können unter Bergsons Bildbegriff fallen, können die Wahrnehmung oder das Wahrgenommensein, unter das sie sich stellen, herbeiführen, ausstellen und operationalisieren. Ein flagrantes Beispiel dafür ist das Diorama, in Sonderheit das in Naturkunde-Museen zu findende Habitat-Diorama. Im folgenden werde ich ein Diorama exemplarisch analysieren, und zwar in Hinsicht auf ein von Deleuze anhand des Bewegungsbildes entwickeltes (doppeltes) Kriterium, nämlich dasjenige der Leere und der Fülle. Dies wird es möglich machen, Film und Diorama zu vergleichen, Eigenschaften des Bewegungs- und des Zeitbildes in verschobener Weise auch im Diorama wiederzufinden und zugleich markante Unterschiede zu beobachten. Zudem werden auch verschiedene Typen des Dioramas in ihrem Verhältnis zueinander und in ihren Übergängen konturierbar. Dabei werden auch in Sonderheit die Phänomene der Atmosphäre, der Indexikalität und der Evidenz relevant.
Media and abstraction
(2019)
The question to be discussed in this essay concerns the relation between different media and the distinction between concrete and abstract entities or objects. [...] But what is the motivation for this paper? To put it bluntly - there seems to be a certain tendency in recent media studies to reject abstract entities and objects. And this comes as no surprise, given the insistence on materiality in media studies (but is materiality really identical to concreteness?).
Mit dem vorliegenden Eröffnungsband der Medienkomparatistik soll ein neues Forum für medienvergleichende Forschung initiiert werden. Das Zusammenwirken unterschiedlicher Medien und verschiedener medialer Praktiken spielt nicht nur in der gegenwärtigen Alltagswelt eine zunehmend bedeutende Rolle. Vielmehr hat sich in den letzten Jahren, ausgehend von den literatur-, kunst-, und medienwissenschaftlichen Einzeldisziplinen ein fächerübergreifendes Diskussionsfeld herausgebildet, das sich gezielt Fragen des Medienvergleichs und der Interferenz von Medien widmet. Dieser interdisziplinäre Forschungsbereich erlebt derzeit in den Kulturwissenschaften eine erstaunliche Konjunktur. Neben der vergleichenden Methodologie als wichtige heuristische Grundlage besteht eine weitere Zielsetzung der Medienkomparatistik darin, allgemeine Kriterien zur systematischen Erfassung der einzelnen Medien zu entwickeln und ihre jeweiligen Operationsleistungen in sich wandelnden kulturellen Kontexten zu erkunden. Im Folgenden soll einleitend der Versuch unternommen werden, einige wichtige Voraussetzungen, Vorgehensweisen, Aufgaben und Besonderheiten medienkomparatistischer Ansätze zu skizzieren.
We report on the first femtoscopic measurement of baryon pairs, such as p−p, p−Λ, and Λ−Λ, measured by ALICE at the Large Hadron Collider (LHC) in proton-proton collisions at √s=7TeV. This study demonstrates the feasibility of such measurements in pp collisions at ultrarelativistic energies. The femtoscopy method is employed to constrain the hyperon-nucleon and hyperon-hyperon interactions, which are still rather poorly understood. A new method to evaluate the influence of residual correlations induced by the decays of resonances and experimental impurities is hereby presented. The p−p, p−Λ, and Λ−Λ correlation functions were fitted simultaneously with the help of a new tool developed specifically for the femtoscopy analysis in small colliding systems: Correlation Analysis Tool using the Schrödinger equation (CATS). Within the assumption that in pp collisions the three particle pairs originate from a common source, its radius is found to be equal to r0=1.125±0.018(stat)+0.058−0.035(syst) fm. The sensitivity of the measured p−Λ correlation is tested against different scattering parameters, which are defined by the interaction among the two particles, but the statistics is not sufficient yet to discriminate among different models. The measurement of the Λ−Λ correlation function constrains the phase space spanned by the effective range and scattering length of the strong interaction. Discrepancies between the measured scattering parameters and the resulting correlation functions at LHC and RHIC energies are discussed in the context of various models.
The production of the ρ(770)0 meson has been measured at mid-rapidity (|y|<0.5) in pp and centrality differential Pb-Pb collisions at sNN−−−√ = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The particles have been reconstructed in the ρ(770)→π+π− decay channel in the transverse momentum (pT) range 0.5−11 GeV/c. A centrality dependent suppression of the ratio of the integrated yields 2ρ(770)0/(π++π−) is observed. The ratio decreases by ∼40% from pp to central Pb-Pb collisions. A study of the pT-differential 2ρ(770)0/(π++π−) ratio reveals that the suppression occurs at low transverse momenta, pT<2 GeV/c. At higher momentum, particle ratios measured in heavy-ion and pp collisions are consistent. The observed suppression is very similar to that previously measured for the K∗(892)0/K ratio and is consistent with EPOS3 predictions that may imply that rescattering in the hadronic phase is a dominant mechanism for the observed suppression.
This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ−. The result is extracted from two-particle correlations of combined p−Ξ−⊕¯p−¯Ξ+ pairs measured in p−Pb collisions at √sNN=5.02 TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p−Ξ−⊕¯p−¯Ξ+ correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ− interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.
The procedure for the energy calibration of the high granularity electromagnetic calorimeter PHOS of the ALICE experiment is presented. The methods used to perform the relative gain calibration, to evaluate the geometrical alignment and the corresponding correction of the absolute energy scale, to obtain the nonlinearity correction coefficients and finally, to calculate the time-dependent calibration corrections, are discussed and illustrated by the PHOS performance in proton-proton (pp) collisions at √s=13 TeV. After applying all corrections, the achieved mass resolutions for π0 and η mesons for pT > 1.7 GeV/c are σmπ0 = 4.56 ± 0.03 MeV/c2 and σmη = 15.3 ± 1.0 MeV/c2, respectively.
Product aesthetics is a powerful means for achieving competitive advantage. Yet most studies to date have focused on the role of aesthetics in shaping pre-purchase preferences and have failed to consider how product aesthetics affects post-purchase processes and consumers' usage behavior. This research focuses on the relationship between aesthetics and usage behavior in the context of durable products. Studies 1A to 1C provide evidence of a positive effect of product aesthetics on usage intensity using market data from the car and the fashion industries. Study 2 corroborates these findings and shows that the more intensive use of highly aesthetic products may lead to the acquisition of product-specific usage skills that form the basis for a cognitive lock-in. Hence, consumers are less likely to switch away from products with appealing designs, an effect that is labeled as the ‘aesthetic fidelity’ effect. Study 3 addresses an alternative explanation for the ‘aesthetic fidelity effect’ based on mood and motivation but finds that the ‘aesthetic fidelity’ effect is indeed determined by usage intensity. Finally, Study 4 identifies a boundary condition of the positive effect of product aesthetics on product usage, showing that it is limited to durable products. In sum, this research demonstrates that the effects of product aesthetics extend beyond the pre-consumption stage and have an enduring impact on people's consumption experiences.
Cardiovascular diseases (CVDs) remain the leading cause of death worldwide. Many studies have provided evidence that both genetic and environmental factors induce atherosclerosis, leading thus to cardiovascular complications. Atherosclerosis is an inflammatory disease, and aging is strongly associated with the development of atherosclerosis. Recent experimental evidence suggests that clonal hematopoiesis (CH) is an emerging cardiovascular risk factor that contributes to the development of atherosclerosis and cardiac dysfunction and exacerbates cardiovascular diseases. CH is caused by somatic mutations in recurrent genes in hematopoietic stem cells, leading to the clonal expansion of mutated blood cell clones. Many of the mutated genes are known in the context of myeloid neoplasms. However, only some individuals carrying CH mutations develop hematologic abnormalities. CH is clearly age dependent and is not rare: at least 10%–20% of people >70 years old carry CH. The newly discovered association between myeloid leukemia-driver mutations and the progression of CVDs has raised medical interest. In this review, we summarize the current view on the contribution of CH in different cardiovascular diseases, CVD risk assessment, patient stratification, and the development of novel therapeutic strategies.
Despite advances in the medical and interventional clinical management of patients, cardiovascular diseases (CVDs) remain the leading cause of death worldwide. It is well appreciated that atherosclerosis represents the underlying cause of most CVDs [1]. Atherosclerosis is a chronic inflammatory disease that leads to the formation of atheromatous lesions in the vessel associated with increased recruitment, adhesion, and proliferation of different leukocyte subsets to the endothelium [1]. Several cardiovascular risk factors (CRFs) have been found to enhance the risk of CVD (Figure 1), including hypercholesterolemia (HC), diabetes mellitus (DM), hypertension, metabolic syndrome, obesity, and smoking [2]. Inflammation plays a crucial role in the development of CVDs and several studies have reported that CRFs enhance production of myeloid cells and multipotent hematopoietic progenitors in the bone marrow and in this way may promote atherosclerosis and disease development [3].
Communication between cells is an important, evolutionarily conserved mechanism which enables the coordinated function of multicellular organisms. Heterogeneity within cell populations drive a remarkable network of cellular cross-talk that allows the heart to function as an integrated unit with distinct tasks allocated to sub-specialized cells. During diseases and aging, cells acquire an overt disordered state that significantly contributes to an altered cellular cross-talk and hence drive cardiac remodeling processes and cardiovascular diseases. However, adaptive mechanisms, and phenotypic changes in subpopulations of cells (e.g. reparative macrophages or fibroblasts) can also contribute to repair and regeneration. In this article, we review the cellular cross-talks between immune cells, endothelial cells, fibroblasts and cardiomyocytes that control heart failure by contributing to cardiac dysfunction and aging, or by mediating repair and regeneration of the heart after injury.
Metacognition plays a pivotal role in human development. The ability to realize that we do not know something, or meta-ignorance, emerges after approximately five years of age. We sought for the brain systems that underlie the developmental emergence of this ability in a preschool sample.
Twenty-four children aged between five and six years answered questions under three conditions. In the critical partial knowledge condition, an experimenter first showed two toys to a child, then announced that she would place one of them in a box, out of sight from the child. The experimenter then asked the child whether she knew which toy was in the box.
Children who gave consistently correct answers to this question (n = 9) showed greater cortical thickness in a cluster within left medial orbitofrontal cortex than children who did not (n = 15). Further, seed-based functional connectivity analyses of the brain during resting state revealed that this region is functionally connected to the medial orbitofrontal gyrus, posterior cingulate gyrus and precuneus, and mid- and inferior temporal gyri.
This finding suggests that the default mode network, critically through its prefrontal regions, supports introspective processing. It leads to the emergence of metacognitive monitoring allowing children to explicitly report their own ignorance.
In case of 4-Rod-type RFQ’s the quadrupole electrodes are excited by a series of coupled RF oscillators. As the contact planes between both electrode pairs differ, there remains an oscillating electric potential along the beam axis. This results in remarkably high longitudinal field components between the electrode ends and the RFQ tank end walls. In contrast, the electrodes of a 4-Vane RFQ are equally charged to ±|V0∕2| and only feature a quadrupole on-axis field. The entrance gap fields were investigated to serve as a longitudinal prebuncher instead of causing additional longitudinal emittance growth. The effects of the entrance gap field have been validated in beam dynamics simulations. The exit fields have to be taken into consideration for a calculation of the exact RFQ output energy.
Solar photovoltaics (PV) panels in combination with batteries are often proposed as a solution to provide stable power supply in rural areas. PV generation is mostly dominated by the solar diurnal cycle and has, in some countries, already started to have influence on the daily price distribution on the electricity market.
In this work, we study the performance and optimisation of rural PV-battery hybrid systems in a future renewable Polish power system. We use data on generation potentials to study PV and battery deployment. Together with a power system optimisation and dispatch model for the Polish power system, we study market values when selling at the national market for different CO2 price scenarios. We show that optimal orientations with respect to tilt/azimuth are subject to change as the PV share grows and that the benefit from batteries grows for higher shares of renewables.