Beschäftigungswirkung neugegründeter Betriebe

"In der Arbeit wird die Beschäftigungsentwicklung von Betrieben, die 1985 in München und Oberbayern gegründet wurden, während der ersten vier Jahre ihres Bestehens verfolgt. Durch diese neuen Unternehmen entstand im Jahre 1985 ein Stellenzuwachs von etwa 3,5%. Die Zahl neugeschaffener Stellen wurde während des Beobachtungszeitraumes noch erhöht. Dabei zeigt sich, daß hinter diesem Nettoanstieg wesentlich umfangreichere Bruttoströme von Stellenzuwächsen (durch betriebliches Wachstum) und Stellenabbau (durch Schließung und Schrumpfung von Unternehmen) stehen. Weitere Analysen zeigen, daß die Beschäftigungsentwicklung nicht in allen Gruppen positiv verläuft: Betriebe weiblicher Gründer und solche von zuvor nicht erwerbstätigen Personen (Arbeitslose, Hausfrauen, Rentner, usw.) zeigen während des Untersuchungszeitraums eine abnehmende Beschäftigungstendenz. Dies ist weitgehend auf eine zu schwache Wachstumsdynamik dieser Gruppen von Unternehmen zurückzuführen, weshalb die Stellenverluste nicht kompensiert werden können. Demgegenüber zeigt insbesondere die Gruppe der innovativen Firmen eine auffallend starke Wachstumsdynamik, die sich auch in deutlichen Beschäftigungseffekten niederschlägt. Zum Schluß werden einige wirtschaftspolitische Implikationen der Befunde diskutiert." (Autorenreferat, IAB-Doku)Unternehmensgründung, Beschäftigungseffekte, München, Oberbayern, Bayern, Bundesrepublik Deutschland

Introducing the MeVCube concept: a CubeSat for MeV observations

Despite the impressive progress achieved both by X-ray and gamma-ray observatories in the last few decades, the energy range between $\sim200\;\mathrm{keV}$ and $\sim50\;\mathrm{MeV}$ remains poorly explored. COMPTEL, on-board the Compton Gamma-Ray Observatory (CGRO, $1991$-$2000$), opened the MeV gamma-ray band as a new window to astronomy, performing the first all-sky survey in the energy range from $0.75$ to $30\;\mathrm{MeV}$. More than $20$ years after the de-orbit of CGRO, no successor mission is yet operating. Over the past years many concepts have been proposed, for new observatories exploring different configurations and imaging techniques; a selection of the most recent ones includes AMEGO, ETCC, GECCO and COSI. We propose here a novel concept for a Compton telescope based on the CubeSat standard, named MeVCube, with the advantages of small cost and relatively short development time. The scientific payload is based on two layers of pixelated Cadmium-Zinc-Telluride (CdZnTe) detectors, coupled with low-power read-out electronics (ASIC, VATA450.3). The performance of the read-out electronics and CdZnTe custom designed detectors have been measured extensively at DESY. The performance of the telescope is accessed through simulations: despite a small effective area limited to a few $\mathrm{cm}^{2}$, MeVCube can reach an angular resolution of $1.5^{\circ}$ and a sensitivity comparable to the one achieved by the last generation of large-scale satellites like COMPTEL and INTEGRAL. Combined with a large field-of-view and a moderate cost, MeVCube can be a powerful instrument for transient observations and searches of electromagnetic counterparts of gravitational wave events

Introducing the MeVCube concept: a CubeSat for MeV observations

Despite the impressive progress achieved both by X-ray and gamma-ray observatories in the last few decades, the energy range between ∼ 200 keV and ∼ 50 MeV remains poorly explored. COMPTEL, on-board the Compton Gamma-Ray Observatory (CGRO, 1991-2000), opened the MeV gamma-ray band as a new window to astronomy, performing the first all-sky survey in the energy range from 0.75 to 30 MeV. More than 20 years after the de-orbit of CGRO, no successor mission is yet operating. Over the past years many concepts have been proposed, for new observatories exploring different configurations and imaging techniques; a selection of the most recent ones includes AMEGO, ETCC, GECCO and COSI. We propose here a novel concept for a Compton telescope based on the CubeSat standard, named MeVCube, with the advantages of small cost and relatively short development time. The scientific payload is based on two layers of pixelated Cadmium-Zinc-Telluride (CdZnTe) detectors, coupled with low-power read-out electronics (ASIC, VATA450.3). The performance of the read-out electronics and CdZnTe custom designed detectors have been measured extensively at DESY [1]. The performance of the telescope is accessed through simulations: despite a small effective area limited to a few cm2, MeVCube can reach an angular resolution of 1.5° and a sensitivity comparable to the one achieved by the last generation of large-scale satellites like COMPTEL and INTEGRAL. Combined with a large field-of-view and a moderate cost, MeVCube can be a powerful instrument for transient observations and searches of electromagnetic counterparts of gravitational wave events.Peer Reviewe

Building pondscapes for amphibian metapopulations

The success of ponds constructed to restore ecological infrastructure for pond‐breeding amphibians and benefit aquatic biodiversity depends on where and how they are built. We studied effects of pond and landscape characteristics, including connectivity, on metapopulation dynamics of 12 amphibian species in Switzerland. To understand the determinants of long‐term occupancy (here summarized as incidence), environmental effects on both colonization and persistence should be considered. We fitted dynamic occupancy models to 20 years of monitoring data on a pond construction program to quantify effects of pond and landscape characteristics and different connectivity metrics on colonization and persistence probabilities in constructed ponds. Connectivity to existing populations explained dynamics better than structural connectivity metrics, and simple metrics (distance to the nearest neighbor population, population density) were useful surrogates for dispersal kernel‐weighted metrics commonly used in metapopulation theory. Population connectivity mediated the persistence of conservation target species in new ponds, suggesting source–sink dynamics in newly established populations. Population density captured this effect well and could be used by practitioners for site selection. Ponds created where there were 2–4 occupied ponds within a radius of ∼0.5 km had >3.5 times higher incidence of target species (median) than isolated ponds. Species had individual preferences regarding pond characteristics, but breeding sites with larger (≥100 m$^{2}$) total water surface area, that temporarily dried, and that were in surroundings with maximally 50% forest benefitted multiple target species. Pond diversity will foster amphibian diversity at the landscape scale

Characterization of a CdZnTe detector for a low-power CubeSat application

We report spectral and imaging performance of a pixelated CdZnTe detector custom designed for the MeVCube project: a small Compton telescope on a CubeSat platform. MeVCube is expected to cover the energy range between 200 keV and 4 MeV, with a sensitivity comparable to the one of the last generation of larger satellites. In order to achieve this goal, an energy resolution of few percent in full width at half maximum (FWHM) and a 3-D spatial resolution of few millimeters for the individual detectors are needed. The severe power constraints present in small satellites require very low power read-out electronics for the detector. Our read-out is based on the VATA450.3 ASIC developed by Ideas, with a power consumption of only 0.25 mW/channel, which exhibits good performance in terms of dynamic range, noise and linearity. A 2.0 cm× 2.0 cm× 1.5 cm CdZnTe detector, with a custom 8 × 8 pixel anode structure read-out by a VATA450.3 ASIC, has been tested. A preliminary read-out system for the cathode, based on a discrete Amptek A250F charge sensitive pre-amplifier and a DRS4 ASIC, has been implemented. An energy resolution around 3% FWHM has been measured at a gamma energy of 662 keV; at 200 keV the average energy resolution is 6.5%, decreasing to ≲ 2% at energies above 1 MeV. A 3-D spatial resolution of ≈ 2 mm is achieved in each dimension.Peer Reviewe

Characterization of a CdZnTe detector for a low-power CubeSat application

We report spectral and imaging performance of a pixelated CdZnTe detector custom designed for the \emph{MeVCube} project: a small Compton telescope on a CubeSat platform. \emph{MeVCube} is expected to cover the energy range between $200\;\mathrm{keV}$ and $4\;\mathrm{MeV}$, with performance comparable to the last generation of larger satellites. In order to achieve this goal, an energy resolution of few percent in full width at half maximum (FWHM) and a $3$-D spatial resolution of few millimeters for the individual detectors are needed. The severe power constraints present in small satellites require very low power read-out electronics for the detector. Our read-out is based on the VATA450.3 ASIC developed by \emph{Ideas}, with a power consumption of only $0.25\;\mathrm{mW/channel}$, which exhibits good performance in terms of dynamic range, noise and linearity. A $2.0\;\mathrm{cm} \times 2.0\;\mathrm{cm} \times 1.5\;\mathrm{cm}$ CdZnTe detector, with a custom $8 \times 8$ pixel anode structure read-out by a VATA450.3 ASIC, has been tested. A preliminary read-out system for the cathode, based on a discrete \emph{Amptek} A250F charge sensitive pre-amplifier and a DRS4 ASIC, has been implemented. An energy resolution around $3\%$ FWHM has been measured at a gamma energy of $662\;\mathrm{keV}$; at $200\;\mathrm{keV}$ the average energy resolution is $6.5\%$, decreasing to $\lesssim 2\%$ at energies above $1\;\mathrm{MeV}$. A $3$-D spatial resolution of $\approx 2\,\mathrm{mm}$ is achieved

Bending the curve: Simple but massive conservation action leads to landscape-scale recovery of amphibians

Success stories are rare in conservation science, hindered also by the research-implementation gap, where scientific insights rarely inform practice and practical implementation is rarely evaluated scientifically. Amphibian population declines, driven by multiple stressors, are emblematic of the freshwater biodiversity crisis. Habitat creation is a straightforward conservation action that has been shown to locally benefit amphibians, as well as other taxa, but does it benefit entire amphibian communities at large spatial scales? Here, we evaluate a landscape-scale pond-construction program by fitting dynamic occupancy models to 20 y of monitoring data for 12 pond-breeding amphibian species in the Swiss state Aargau, a densely populated area of the Swiss lowlands with intensive land use. After decades of population declines, the number of occupied ponds increased statewide for 10 out of 12 species, while one species remained stable and one species further declined between 1999 and 2019. Despite regional differences, in 77% of all 43 regional metapopulations, the colonization and subsequent occupation of new ponds stabilized (14%) or increased (63%) metapopulation size. Likely mechanisms include increased habitat availability, restoration of habitat dynamics, and increased connectivity between ponds. Colonization probabilities reflected species-specific preferences for characteristics of ponds and their surroundings, which provides evidence-based information for future pond construction targeting specific species. The relatively simple but landscape-scale and persistent conservation action of constructing hundreds of new ponds halted declines and stabilized or increased the state-wide population size of all but one species, despite ongoing pressures from other stressors in a human-dominated landscape

Solution-Processed Cu2_2S Nanostructures for Solar Hydrogen Production

Cu$_2$S is a promising solar energy conversion material due to its suitable optical properties, high elemental earth abundance, and nontoxicity. In addition to the challenge of multiple stable secondary phases, the short minority carrier diffusion length poses an obstacle to its practical application. This work addresses the issue by synthesizing nanostructured Cu$_2$S thin films, which enables increased charge carrier collection. A simple solution-processing method involving the preparation of CuCl and CuCl$_2$ molecular inks in a thiol-amine solvent mixture followed by spin coating and low-temperature annealing was used to obtain phase-pure nanostructured (nanoplate and nanoparticle) Cu$_2$S thin films. The photocathode based on the nanoplate Cu$_2$S (FTO/Au/Cu$_2$S/CdS/TiO$_2$/RuO$_x$) reveals enhanced charge carrier collection and improved photoelectrochemical water-splitting performance compared to the photocathode based on the non-nanostructured Cu$_2$S thin film reported previously. A photocurrent density of 3.0 mA cm$^{–2}$ at −0.2 versus a reversible hydrogen electrode (V$_{RHE}$) with only 100 nm thickness of a nanoplate Cu$_2$S layer and an onset potential of 0.43 V$_{RHE}$ were obtained. This work provides a simple, cost-effective, and high-throughput method to prepare phase-pure nanostructured Cu$_2$S thin films for scalable solar hydrogen production

Zum Zusammenhang von Geschlechterungleichheiten in Bildung, Beruf und Karriere : ein Ausblick

Ziel der folgenden Ausführungen im abschliessenden Teil dieses Sammelbands zur Entwicklung und Genese von geschlechtsspezifischen Bildungsungleichheiten ist es, den Blick zu öffnen in Richtung Berufsleben. Wie sind die verbesserten Bildungsmöglichkeiten von Frauen zu interpretieren? Ist es in den letzten Jahrzehnten gelungen, eines der grundlegendsten gesellschaftlichen Ungleichheitsverhältnisse zu beseitigen? Oder beginnt sich dieses sogar zu verkehren in eine gesellschaftliche Benachteiligung der Männer? Wir gehen bei unseren Überlegungen von der These aus, dass ein Abbau von Benachteiligungen der Frauen im Bildungssystem für sich genommen noch wenig aussagekräftig ist, wenn wir uns mit der klassischen soziologischen Frage der Persistenz bzw. des Wandels von gesellschaftlichen Ungleichheiten befassen wollen. Erst wenn die ganze Verknüpfung von Bildung und gesellschaftlicher Ungleichheit in den Blick genommen wird und sich dabei zeigt, dass Frauen ihre Bildungsgewinne auch in entsprechende Chancen im Beschäftigungssystem umsetzen können, sind ihre verbesserten Bildungschancen ein Gewinn für die Individuen und ein Fortschritt für die Gesellschaft – und erst dann könnten mögliche Bildungsvorteile von Frauen, wie sie in den vorliegenden Aufsätzen z.T. diagnostiziert werden, gar als neue gesellschaftliche Benachteiligungen von Männern skandalisiert werden