1,734 research outputs found
Municipality Size and Efficiency of Local Public Services: Does Size Matter?
Similarly to western Germany in the 1960s and 1970s, the eastern part of Germany has experienced a still ongoing process of numerous amalgamations among counties, towns and municipalities since the mid-1990s. The evidence in the economic literature is mixed with regard to the claimed expenditure reductions and efficiency gains from municipal mergers. We therefore analyze the global efficiency of the municipalities in Saxony-Anhalt, for the first time in this context, using a double-bootstrap procedure combining DEA and truncated regression. This allows including environmental variables to control for exogenous determinants of municipal efficiency. Our focus thereby is on institutional and fiscal variables. Moreover, the scale efficiency is estimated to find out whether large units are necessary to benefit from scale economies. In contrast to previous studies, we chose the aggregate budget of municipal associations (“Verwaltungsgemeinschaften”) as the object of our analysis since important competences of the member municipalities are settled on a joint administrative level. Furthermore, we use a data set that has been carefully adjusted for bookkeeping items and transfers within the communal level. On the “eve” of a mayor municipal reform the majority of the municipalities were found to have an approximately scale-efficient size and centralized organizational forms (“Einheitsgemeinden”) showed no efficiency advantage over municipal associations.efficiency, local government, DEA, bootstrap, demographic change, local institutions
New Insights into Cosmic Ray induced Biosignature Chemistry in Earth-like Atmospheres
With the recent discoveries of terrestrial planets around active M-dwarfs,
destruction processes masking the possible presence of life are receiving
increased attention in the exoplanet community. We investigate potential
biosignatures of planets having Earth-like (N-O) atmospheres orbiting
in the habitable zone of the M-dwarf star AD Leo. These are bombarded by high
energetic particles which can create showers of secondary particles at the
surface. We apply our cloud-free 1D climate-chemistry model to study the
influence of key particle shower parameters and chemical efficiencies of NOx
and HOx production from cosmic rays. We determine the effect of stellar
radiation and cosmic rays upon atmospheric composition, temperature, and
spectral appearance. Despite strong stratospheric O destruction by cosmic
rays, smog O can significantly build up in the lower atmosphere of our
modeled planet around AD Leo related to low stellar UVB. NO abundances
decrease with increasing flaring energies but a sink reaction for NO with
excited oxygen becomes weaker, stabilizing its abundance. CH is removed
mainly by Cl in the upper atmosphere for strong flaring cases and not via
hydroxyl as is otherwise usually the case. Cosmic rays weaken the role of
CH in heating the middle atmosphere so that HO absorption becomes more
important. We additionally underline the importance of HNO as a possible
marker for strong stellar particle showers. In a nutshell, uncertainty in NOx
and HOx production from cosmic rays significantly influences biosignature
abundances and spectral appearance.Comment: Manuscript version after addressing all referee comments. Published
in Ap
Efficient photosynthesis of carbon monoxide from CO2 using perovskite photovoltaics
Artificial photosynthesis, mimicking nature in its efforts to store solar energy, has received considerable attention from the research community. Most of these attempts target the production of H2 as a fuel and our group recently demonstrated solar-to-hydrogen conversion at 12.3% efficiency. Here, in an effort to take this approach closer to real photosynthesis, which is based on the conversion of CO2, we demonstrate the efficient reduction of CO2 to carbon monoxide driven solely by simulated sunlight using water as the electron source. Employing series-connected perovskite photovoltaics and high-performance catalyst electrodes, we reach a solar-to-CO efficiency exceeding 6.5%, which represents a new benchmark in sunlight-driven CO2 conversion. Considering hydrogen as a secondary product, an efficiency exceeding 7% is observed. Furthermore, this study represents one of the first demonstrations of extended, stable operation of perovskite photovoltaics, whose large open-circuit voltage is shown to be particularly suited for this process
Consistently Simulating a Wide Range of Atmospheric Scenarios for K2-18b with a Flexible Radiative Transfer Module
The atmospheres of small, potentially rocky exoplanets are expected to cover
a diverse range in composition and mass. Studying such objects therefore
requires flexible and wide-ranging modeling capabilities. We present in this
work the essential development steps that lead to our flexible radiative
transfer module, REDFOX, and validate REDFOX for the Solar system planets
Earth, Venus and Mars, as well as for steam atmospheres. REDFOX is a
k-distribution model using the correlated-k approach with random overlap method
for the calculation of opacities used in the -two-stream approximation
for radiative transfer. Opacity contributions from Rayleigh scattering, UV /
visible cross sections and continua can be added selectively. With the improved
capabilities of our new model, we calculate various atmospheric scenarios for
K2-18b, a super-Earth / sub-Neptune with 8 M orbiting in the
temperate zone around an M-star, with recently observed HO spectral
features in the infrared. We model Earth-like, Venus-like, as well as H-He
primary atmospheres of different Solar metallicity and show resulting climates
and spectral characteristics, compared to observed data. Our results suggest
that K2-18b has an H-He atmosphere with limited amounts of HO and
CH. Results do not support the possibility of K2-18b having a water
reservoir directly exposed to the atmosphere, which would reduce atmospheric
scale heights, hence too the amplitudes of spectral features inconsistent with
the observations. We also performed tests for H-He atmospheres up to 50
times Solar metallicity, all compatible with the observations.Comment: 28 pages, 13 figures, accepted for publication in Ap
Detectability of atmospheric features of Earth-like planets in the habitable zone around M dwarfs
We investigate the detectability of atmospheric spectral features of
Earth-like planets in the habitable zone (HZ) around M dwarfs with the future
James Webb Space Telescope (JWST). We use a coupled 1D climate-chemistry-model
to simulate the influence of a range of observed and modelled M-dwarf spectra
on Earth-like planets. The simulated atmospheres served as input for the
calculation of the transmission spectra of the hypothetical planets, using a
line-by-line spectral radiative transfer model. To investigate the
spectroscopic detectability of absorption bands with JWST we further developed
a signal-to-noise ratio (S/N) model and applied it to our transmission spectra.
High abundances of CH and HO in the atmosphere of Earth-like planets
around mid to late M dwarfs increase the detectability of the corresponding
spectral features compared to early M-dwarf planets. Increased temperatures in
the middle atmosphere of mid- to late-type M-dwarf planets expand the
atmosphere and further increase the detectability of absorption bands. To
detect CH, HO, and CO in the atmosphere of an Earth-like planet
around a mid to late M dwarf observing only one transit with JWST could be
enough up to a distance of 4 pc and less than ten transits up to a distance of
10 pc. As a consequence of saturation limits of JWST and less pronounced
absorption bands, the detection of spectral features of hypothetical Earth-like
planets around most early M dwarfs would require more than ten transits. We
identify 276 existing M dwarfs (including GJ 1132, TRAPPIST-1, GJ 1214, and LHS
1140) around which atmospheric absorption features of hypothetical Earth-like
planets could be detected by co-adding just a few transits. We show that using
transmission spectroscopy, JWST could provide enough precision to be able to
partly characterise the atmosphere of Earth-like TESS planets around mid to
late M dwarfs.Comment: 18 pages, 10 figure
Interstitial water hyperthermia: temperature distribution data obtained in animal experiments compared to human application measurements
Pathways between childhood victimization and psychosis-like symptoms in the ALSPAC Birth Cohort
Background: Several large population-based studies have demonstrated associations between adverse childhood experiences and later development of psychotic symptoms. However, little attention has been paid to the mechanisms involved in this pathway and the few existing studies have relied on cross-sectional assessments. Methods: Prospective data on 6692 children from the UK Avon Longitudinal Study of Parents and Children (ALSPAC) were used to address this issue. Mothers reported on children’s exposure to harsh parenting and domestic violence in early childhood, and children self-reported on bullying victimization prior to 8.5 years. Presence of children’s anxiety at 10 years and their depressive symptoms at 9 and 11 years were ascertained from mothers, and children completed assessments of self-esteem and locus of control at 8.5 years. Children were interviewed regarding psychotic symptoms at a mean age of 12.9 years. Multiple mediation analysis was performed to examine direct and indirect effects of each childhood adversity on psychotic symptoms. Results: The association between harsh parenting and psychotic symptoms was fully mediated by anxiety, depressive symptoms, external locus of control, and low self-esteem. Bullying victimization and exposure to domestic violence had their associations with psychotic symptoms partially mediated by anxiety, depression, locus of control, and self-esteem. Similar results were obtained following adjustment for a range of confounders and when analyses were conducted for boys and girls separately. Conclusions: These findings tentatively suggest that specific cognitive and affective difficulties in childhood could be targeted to minimize the likelihood of adolescents exposed to early trauma from developing psychotic symptoms
Sideband Transitions and Two-Tone Spectroscopy of a Superconducting Qubit Strongly Coupled to an On-Chip Cavity
Sideband transitions are spectroscopically probed in a system consisting of a
Cooper pair box strongly but non-resonantly coupled to a superconducting
transmission line resonator. When the Cooper pair box is operated at the
optimal charge bias point the symmetry of the hamiltonian requires a two photon
process to access sidebands. The observed large dispersive ac-Stark shifts in
the sideband transitions induced by the strong non-resonant drives agree well
with our theoretical predictions. Sideband transitions are important in
realizing qubit-photon and qubit-qubit entanglement in the circuit quantum
electrodynamics architecture for quantum information processing.Comment: 4 pages, 5 figures, version with high resolution figures available at
http://qudev.ethz.ch/content/science/PubsPapers.htm
Ion channel-like activity of the antimicrobial peptide tritrpticin in planar lipid bilayers
The cationic peptide tritrpticin (VRRFPWWWPFLRR, Trp3) has a broad action spectrum, acting against Gram-positive and Gram-negative bacteria, as well as some fungi, while also displaying hemolytic activity. We have studied the behavior of Trp3 in planar lipid bilayers (or black lipid membrane-BLM) and were able to demonstrate its ion channel-like activity. Channel-like activity was observed in negatively charged azolectin BLM as a sudden appearance of discrete current fluctuations upon application of a constant voltage across the membrane. Trp3 formed large conductance channels (500-2000 pS) both at positive and negative potentials. in azolectin bilayers, the predominant ion-channel activity was characterized by very regular and discrete current steps (corresponding to openings) of uniform amplitude, which exhibited relatively long residence times (of the order of seconds). Occasionally, multiple conductance steps were observed, indicating the simultaneous presence of more than one open pore. in bilayers of zwitterionic diphytanoylphosphatidyl choline (DPhk) Trp3 also showed ion-channel activity, but in a much less frequent and less prominent way. Studies of ion selectivity indicated that Trp3 forms a cation-selective channel. These results should contribute to the understanding of the molecular interactions and mechanism of action of Trp3 in lipid bilayers and biological membranes. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.Univ São Paulo, Inst Chem, Dept Biochem, Struct Biol Lab, BR-05513970 São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05389970 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04044020 São Paulo, BrazilWeb of Scienc
Outcomes of Hip Fractures at Teaching Hospitals Versus Non-Teaching Hospitals
Hip fractures in adults are associated with a large burden of suffering in the United States and are a major focus of various advocacy groups, professional organizations and government agencies. Strategies for prevention of hip fractures include primary prevention of osteoporosis, secondary prevention of fractures in patients with asymptomatic osteoporosis, tertiary prevention of complications in patients with hip fractures, and quarternary prevention of long-term disability from hip fracture. As a tertiary prevention option, surgery to repair a hip fracture has many benefits but is still associated with negative outcomes. This research establishes the evidence base and proposes a secondary analysis for determining whether patients treated for hip fracture at teaching hospitals experience fewer negative outcomes than do patients treated at non-teaching hospitals. A systematic review of the literature does not permit the drawing of firm conclusions about teaching hospital status, but a secondary analysis of data from the Nationwide Inpatient Sample (NIS) database could advance our understanding of the context of hip fracture outcomes. A study sample, based on patients with ICD-9 diagnosis codes for hip fracture, can be drawn from admissions represented in the NIS database, and outcomes including rates of mortality, rates of various postoperative complications, lengths of stay, cost, and discharge dispositions can be correlated with forms of treatment and teaching hospital status.Master of Public Healt
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