Gender and Banking: Are Women Better Loan Officers?

We analyze gender differences associated with loan officer performance. Using a unique data set for a commercial bank in Albania over the period 1996 to 2006, we find that loans screened and monitored by female loan officers show statistically and economically significant lower default rates than loans handled by male loan officers. This effect comes in addition to a lower default rate of female borrowers and cannot be explained by sample selection, overconfidence of male loan officers or experience differences between female and male loan officers. Our results seem to be driven by differences in monitoring, as loan officers of different gender do not seem to screen borrowers differently based on observable borrower characteristics. This suggests that gender indeed matters in banking.Behavioral banking;loan officers;gender;loan default;monitoring;screening

The Impact of Public Guarantees on Bank Risk Taking: Evidence from a Natural Experiment

In 2001, government guarantees for savings banks in Germany were removed following a law suit. We use this natural experiment to examine the effect of government guarantees on bank risk taking, using a large data set of matched bank/borrower information. The results suggest that banks whose government guarantee was removed reduced credit risk by cutting off the riskiest borrowers from credit. At the same time, the banks also increased interest rates on their remaining borrowers. The effects are economically large: the Z-Score of average borrowers increased by 7% and the average loan size declined by 13%. Remaining borrowers paid 57 basis points higher interest rates, despite their higher quality. Using a difference-in-differences approach we show that the effect is larger for banks that ex ante benefitted more from the guarantee. We show that both the credit quality of new customers improved (screening) and that the loans of existing riskier borrowers were less likely to be renewed (monitoring), after the removal of public guarantees. Public guarantees seem to be associated with substantial moral hazard effects.banking;public guarantees;credit risk;moral hazard

Contribution to advanced hot wire wind sensing

The thermal anemometry is a method which allows to estimate wind magnitude be the mean of measuring heat transfer to the ambient in a forced convection process. For Earth's atmosphere condition, this method is typically applied to the hot wires made of temperature dependent electrical conductor, typically platinum or tungsten, which working with overheat in reference to the ambient temperature estimate wind velocity. In case of the low pressure atmospheres, like this on Mars, the mean free path for molecules, due to the rarefied ambient conditions, is much bigger, Using hot wires designed for Earth in this conditions gives that heat exchange at macroscopic scale which does not to obey medium continuum model but rather reveals ballistic behavior Thus, instead of using hot wire, a structure of bigger dimension like hot films are usually propose for such a kind of application. The work included in this thesis is the contribution of the author Lukasz Kowalski to the goal of developing a new generation of wind sensors for the atmosphere of Mars. The work consists in the conception, design, simulation, manufacture and measurement of two novel types wind sensors based on thermal anemometers. The first kind of concept has been developed in this thesis by using hot silicon die made out of silicon wafer of approximate size: 1.5 x 1.5 x 0.5 mm with platinum resistances deposited on top in order to heat it and sense its temperature. These work was been a part of the bigger undertaking under the project name: "Colaboracíoon en el desarrollo de la estación medioambiental denominada REMS ". Inside the project REMS author of thesis was responsible for sensor shape development and concept validation of proposed geometry. Thermal-fluidical model of the device as well as characterization and behavior were analyzed for a simplified 2-D wind model for typical Martian atmospheric conditions. REMS was a Spanish contribution to the NASA mission MSL which has been a great success since rover Curiosity has landed on Mars on 8th August 2012 on Mars near to the Gale Crater location. Since then has been constantly running experiments on the Red Planet sending data to Earth for interpretation. From the experience and knowledge gained during REMS project, the author came out with an idea of the novel spherical sensor structure overcoming some fragility problems detected in the REMS wind sensor. The new 3-D wind sensor concept, besides this advantage, also provided a radical simplification of data post-processing providing comprehensive thermal model based on numerical simulation for any possible wind occurrence. This new device has been developed under Spanish Ministry of the Science and Innovation project: "Sensor de viento para la superficie de Marte para la mission Metnet''. This project, denominated as MEIGA, was a joint effort of many Spanish institution under leadership of Instituto Nacional de Tecnica Aeroespacial (INTA) for the development of space technology for Mars oriented application in a framework of upcoming space mission. To sum up, author's work include contributions to the development of two wind sensor concepts: 1. REMS wind sensor on board of the rover Curiosity in the surface of Mars since August 8th 2012 2. Spherical wind sensor concept developed in a course of MEIGA projec

Forming Planetesimals in Solar and Extrasolar Nebulae

Planets are built from planetesimals: solids larger than a kilometer which grow by colliding pairwise. Planetesimals themselves are unlikely to form by two-body collisions; sub-km objects have gravitational fields individually too weak, and electrostatic attraction is too feeble for growth beyond a few cm. We review the possibility that planetesimals form when self-gravity brings together vast ensembles of small particles. Even when self-gravity is weak, aerodynamic processes can accumulate solids relative to gas, paving the way for gravitational collapse. Particles pile up as they drift radially inward. Gas turbulence stirs particles, but can also seed collapse by clumping them. While the feedback of solids on gas triggers vertical shear instabilities that obstruct self-gravity, this same feedback triggers streaming instabilities that strongly concentrate particles. Numerical simulations find that solids 10-100 cm in size gravitationally collapse in turbulent disks. We outline areas for progress, including the possibility that still smaller objects self-gravitate.Comment: To appear in Annual Reviews. This review is intended to be both current and pedagogical. Incorporates suggestions from the community; further comments welcome. v2: Single-space

Human PAPS Synthase Isoforms Are Dynamically Regulated Enzymes with Access to Nucleus and Cytoplasm

In higher eukaryotes, PAPS synthases are the only enzymes producing the essential sulphate-donor 3′-phospho-adenosine-5′-phosphosulphate (PAPS). Recently, PAPS synthases have been associated with several genetic diseases and retroviral infection. To improve our understanding of their pathobiological functions, we analysed the intracellular localisation of the two human PAPS synthases, PAPSS1 and PAPSS2. For both enzymes, we observed pronounced heterogeneity in their subcellular localisation. PAPSS1 was predominantly nuclear, whereas PAPSS2 localised mainly within the cytoplasm. Treatment with the nuclear export inhibitor leptomycin B had little effect on their localisation. However, a mutagenesis screen revealed an Arg-Arg motif at the kinase interface exhibiting export activity. Notably, both isoforms contain a conserved N-terminal basic Lys-Lys-Xaa-Lys motif indispensable for their nuclear localisation. This nuclear localisation signal was more efficient in PAPSS1 than in PAPSS2. The activities of the identified localisation signals were confirmed by microinjection studies. Collectively, we describe unusual localisation signals of both PAPS synthase isoforms, mobile enzymes capable of executing their function in the cytoplasm as well as in the nucleus

Acceleration of individual, decimetre-sized aggregates in the lower coma of comet 67P/Churyumov-Gerasimenko

We present observations of decimetre-sized, likely ice-containing aggregates ejected from a confined region on the surface of comet 67P/Churyumov-Gerasimenko. The images were obtained with the narrow angle camera of the Optical, Spectroscopic, and Infrared Remote Imaging System on board the Rosetta spacecraft in 2016 January when the comet was at 2 au from the Sun outbound from perihelion.We measure the acceleration of individual aggregates through a 2 h image series. Approximately 50 per cent of the aggregates are accelerated away from the nucleus, and 50 per cent towards it, and likewise towards either horizontal direction. The accelerations are up to one order of magnitude stronger than local gravity, and are most simply explained by the combined effect of gas drag accelerating all aggregates upwards, and the recoil force from asymmetric outgassing, either from rotating aggregates with randomly oriented spin axes and sufficient thermal inertia to shift the temperature maximum away from an aggregate's subsolar region, or from aggregates with variable ice content. At least 10 per cent of the aggregates will escape the gravity field of the nucleus and feed the comet's debris trail, while others may fall back to the surface and contribute to the deposits covering parts of the Northern hemisphere. The rocket force plays a crucial role in pushing these aggregates back towards the surface. Our observations show the future back fall material in the process of ejection, and provide the first direct measurement of the acceleration of aggregates in the innermost coma (<2 km) of a comet, where gas drag is still significant

Regional surface morphology of comet 67P/Churyumov-Gerasimenko from Rosetta/OSIRIS images: The southern hemisphere

Aims. The OSIRIS camera on board the Rosetta spacecraft has been acquiring images of the comet 67P/Churyumov-Gerasimenko (67P)'s nucleus since August 2014. Starting in May 2015, the southern hemisphere gradually became illuminated and was imaged for the first time. Here we present the regional morphology of the southern hemisphere, which serves as a companion to an earlier paper that presented the regional morphology of the northern hemisphere. Methods. We used OSIRIS images that were acquired at orbits ~45-125 km from the center of the comet (corresponding to spatial resolutions of ~0.8 to 2.3 m/pixel) coupled with the use of digital terrain models to define the different regions on the surface, and identify structural boundaries accurately. Results. Seven regions have been defined in the southern hemisphere bringing the total number of defined regions on the surface of the nucleus to 26. These classifications are mainly based on morphological and/or topographic boundaries. The southern hemisphere shows a remarkable dichotomy with its northern counterpart mainly because of the absence of wide-scale smooth terrains, dust coatings and large unambiguous depressions. As a result, the southern hemisphere closely resembles previously identified consolidated regions. An assessment of the overall morphology of comet 67P suggests that the comet's two lobes show surface heterogeneities manifested in different physical/mechanical characteristics, possibly extending to local (i.e., within a single region) scales