4,986 research outputs found
Horizon of quantum black holes in various dimensions
We adapt the horizon wave-function formalism to describe massive static
spherically symmetric sources in a general -dimensional space-time, for
and including the case. We find that the probability
that such objects are (quantum) black holes behaves similarly to the
probability in the framework for . In fact, for , the
probability increases towards unity as the mass grows above the relevant
-dimensional Planck scale . At fixed mass, however,
decreases with increasing , so that a particle with mass has
just about probability to be a black hole in , and smaller for
larger . This result has a potentially strong impact on estimates of black
hole production in colliders. In contrast, for , we find the probability
is comparably larger for smaller masses, but , suggesting
that such lower dimensional black holes are purely quantum and not classical
objects. This result is consistent with recent observations that sub-Planckian
black holes are governed by an effective two-dimensional gravitation theory.
Lastly, we derive Generalised Uncertainty Principle relations for the black
holes under consideration, and find a minimum length corresponding to a
characteristic energy scale of the order of the fundamental gravitational mass
in . For we instead find the uncertainty due to the horizon
fluctuations has the same form as the usual Heisenberg contribution, and
therefore no fundamental scale exists.Comment: Latex, 16 pages, 8 figures. Final version to appear in PL
National Differences in the Prevalence of Depressive Symptoms in Mania: a Naturalistic Study Using the Dsm-5 'with Mixed Features' Specifier M.I.N.I. Module
Introduction In bipolar I disorder (BD1), manic episodes with depressive symptoms are generally more severe than pure manic episodes, but are not easily identified. The DSM-5 'With Mixed Features' specifier, and accompanying patient-rated Mini-International Neuropsychiatric Interview (M.I.N.I.) module, were designed to aid diagnosis. Objectives To examine patients with BD1 who have mania with depressive symptoms, across countries. Aims To improve the identification of depressive symptoms during a BD1 manic episode. Methods This naturalistic study surveyed psychiatrists and their patients with BD1 (manic episode within previous 3 months), in Germany, Italy, Spain, UK, Turkey, Australia, Brazil and Canada. Psychiatrists provided information on depressive symptoms (DSM-5 'With Mixed Features' specifier plus patient-rated M.I.N.I. module); anxiety, irritability, and agitation; suicide attempts; and treatment response. Results Of 1,035 bipolar patients, 34% had mania 'With Mixed Features'(â„05;3 depressive symptoms), and displayed more severe symptoms, and higher rates of attempted suicide than patients without mixed features. Across countries, severe anxiety occurred in 3.5â19.5% of patients; severe irritability in 4.3â17.0%; and severe agitation in 4.3â19.6%. The proportion of patients experiencing 'prominent dysphoria or depressed mood' was highest in Italy (64.2%). Recurrent suicidal ideation ranged from 8.0% (Germany) to 25.7% (Spain); lifetime rate of attempted suicide was highest in Canada (64.7%). Between-country differences were also reflected in the M.I.N.I. module outcomes. Conclusion Patients with BD1 'With Mixed Features', suffer from a greater burden of disease than patients with pure mania, and there is variation between countries â as detected by physician and patient evaluations
Metal nano networks by potential-controlled in situ assembling of gold/silver nanoparticles
Nonâspherical Au/Ag nanoparticles can be generated by chemical reduction of silver ions in the presence of preformed gold nanoparticles. The process of particle formation can be controlled by concentrations of ligands and reducing agent. The formation of ellipsoidal, nanorodâ and peanutâshaped nanoparticles as well as of more complex fractal nanoassemblies can be explained by changes in particle surface state, electrochemical potential formation and particleâinternal selfâpolarization effects. It is possible to create highly fractal nanoassemblies with sizes between the midânanometer and the lower micrometer range. The assemblies are marked by high optical absorption and complex nanoânetworks of very high surfaceâtoâvolume ratios and a granular base structure
The edge of galaxy formation III: The effects of warm dark matter on Milky Way satellites and field dwarfs
In this third paper of the series, we investigate the effects of warm dark
matter with a particle mass of on the smallest
galaxies in our Universe. We present a sample of 21 hydrodynamical cosmological
simulations of dwarf galaxies and 20 simulations of satellite-host galaxy
interaction that we performed both in a Cold Dark Matter (CDM) and Warm Dark
Matter (WDM) scenario. In the WDM simulations, we observe a higher critical
mass for the onset of star formation. Structure growth is delayed in WDM, as a
result WDM haloes have a stellar population on average two Gyrs younger than
their CDM counterparts. Nevertheless, despite this delayed star formation, CDM
and WDM galaxies are both able to reproduce the observed scaling relations for
velocity dispersion, stellar mass, size, and metallicity at . WDM
satellite haloes in a Milky Way mass host are more susceptible to tidal
stripping due to their lower concentrations, but their galaxies can even
survive longer than the CDM counterparts if they live in a dark matter halo
with a steeper central slope. In agreement with our previous CDM satellite
study we observe a steepening of the WDM satellites' central dark matter
density slope due to stripping. The difference in the average stellar age for
satellite galaxies, between CDM and WDM, could be used in the future for
disentangling these two models.Comment: 10 pages, 11 figures, accepted for publication on MNRA
Magnetic Switching of Phase-Slip Dissipation in NbSe2 Nanobelts
The stability of the superconducting dissipationless and resistive states in
single-crystalline NbSe2 nanobelts is characterized by transport measurements
in an external magnetic field (H). Current-driven electrical measurements show
voltage steps, indicating the nucleation of phase-slip structures. Well below
the critical temperature, the position of the voltage steps exhibits a sharp,
periodic dependence as a function of H. This phenomenon is discussed in the
context of two possible mechanisms: the interference of the order parameter and
the periodic rearrangement of the vortex lattice within the nanobelt.Comment: 4 figure
Ideology and Entry Policy: Why Non-Socialist Parties in Sweden Support Open Door Migration Policies
While the continued growth of far-right populist parties across Europe has led to a rich body of literature detailing the impact of anti-immigrant parties on entry policies, less attention has been directed towards analyzing how mainstream non-socialist parties formulate their migration policy preferences. In this paper, we seek to correct this imbalance by addressing the case of Sweden. The conventional wisdom frequently portrays non-socialist parties as proponents of restrictive entry policies for labor migrants and asylum seekers. However, we show that center-right parties and the Greens have largely been the driving force behind key Swedish migration policy developments over the past several decades, allowing greater numbers of migrants to enter and settle permanently. Our analysis shows that non-socialist support for generous entry policies is largely consistent over time, regardless of efforts by far-right populist parties, or the socialist left, to see more restrictive entry policies enacted. To account for this stance, we focus on the role of party ideology as the missing factor. While vote maximization and inter-party competition have their place in accounts of entry policy preference formation, a more nuanced analysis requires examining the role of ideology. Long-held ideological principles help parties evaluate societal change, leading them to formulate generous entry policies in the face of pressure from both the left and the right for stricter migration policies
Association of malalignment, muscular dysfunction, proprioception, laxity and abnormal joint loading with tibiofemoral knee osteoarthritis - a systematic review and meta-analysis
Background: To investigate (1) the association of specific biomechanical factors with knee osteoarthritis and knee osteoarthritis development, and (2) the impact of other relevant risk factors on this association.Methods: MEDLINE, EMBASE, CINAHL and SPORTDiscus were searched up until April 2017. Studies were included if they fulfilled the following criteria: the study 1) assessed the association of a biomechanical factor with knee osteoarthritis, or knee osteoarthritis development; 2) reported on skeletal malalignment, muscular dysfunction, impaired proprioception, laxity and abnormal loading during gait; 3) was a cohort study with participants developing knee osteoarthritis and participants not developing knee osteoarthritis, or a case-control or cross-sectional study with participants with knee osteoarthritis and without knee osteoarthritis. Risk of bias was assessed with the QUIPS tool and meta-analyses were performed using random effects models.Results: Of 6413 unique studies identified, 59 cross-sectional studies were eligible for meta-analyses (9825 participants, 5328 with knee osteoarthritis). No cohort studies fulfilled the inclusion criteria. Compared with healthy controls, patients with knee osteoarthritis have higher odds of having lower muscle strength, proprioception deficits, more medial varus-valgus laxity and less lateral varus-valgus laxity. Patients with medial knee osteoarthritis have higher odds of having a higher knee adduction moment than healthy controls. Level of evidence was graded as 'very low' to 'moderate' quality. Due to large between study differences moderation of other risk factors on biomechanical risk factors could not be evaluated.Conclusions: Patients with knee osteoarthritis are more likely to display a number of biomechanical characteristics. The causal relationship between specific biomechanical factors and the development of knee osteoarthritis could not be determined as no longitudinal studies were included. There is an urgent need for high quality, longitudinal studies to evaluate the impact of specific biomechanical factors on the development of knee osteoarthritis.Trial Registration: (PROSPERO ID: CRD42015025092)
Is Steam Explosion a Promising Pretreatment for Acid Hydrolysis of Lignocellulosic Biomass?
For the production of sugars and biobased platform chemicals from lignocellulosic biomass, the hydrolysis of cellulose and hemicelluloses to water-soluble sugars is a crucial step. As the complex structure of lignocellulosic biomass hinders an efficient hydrolysis via acid hydrolysis, a suitable pretreatment strategy is of special importance. The pretreatment steam explosion was intended to increase the accessibility of the cellulose fibers so that the subsequent acid hydrolysis of the cellulose to glucose would take place in a shorter time. Steam explosion pretreatment was performed with beech wood chips at varying severities with different reaction times (25â34 min) and maximum temperatures (186â223 °C). However, the subsequent acid hydrolysis step of steam-exploded residue was performed at constant settings at 180 °C with diluted sulfuric acid. The concentration profiles of the main water-soluble hydrolysis products were recorded. We showed in this study that the defibration of the macrofibrils in the lignocellulose structure during steam explosion does not lead to an increased rate of cellulose hydrolysis. So, steam explosion is not a suitable pretreatment for acid hydrolysis of hardwood lignocellulosic biomass
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