Why Are East Germans Not More Mobile?: Analyzing the Impact of Local Networks on Migration Intentions

Despite poor regional labour market conditions East Germans exhibit a rather limited willing-ness of leaving their home region. Applying an IV ordered probit approach and using the German Socio Economic Panel (SOEP), we test a local network explanation of lower spatial mobility. Firstly, we find that membership in locally bounded social networks reduces regional mobility. Secondly, we show that native East Germans are more invested in this type of social networks than West Germans. Thirdly, after controlling for the social network effect the mobility gap between East and West substantially reduces. Thus, low regional labour mobility of East Germans is for a significant part attributable to local ties binding people to their home region.Social networks, labour mobility

A Systematic Review on Model Watermarking for Neural Networks

Machine learning (ML) models are applied in an increasing variety of domains. The availability of large amounts of data and computational resources encourages the development of ever more complex and valuable models. These models are considered intellectual property of the legitimate parties who have trained them, which makes their protection against stealing, illegitimate redistribution, and unauthorized application an urgent need. Digital watermarking presents a strong mechanism for marking model ownership and, thereby, offers protection against those threats. This work presents a taxonomy identifying and analyzing different classes of watermarking schemes for ML models. It introduces a unified threat model to allow structured reasoning on and comparison of the effectiveness of watermarking methods in different scenarios. Furthermore, it systematizes desired security requirements and attacks against ML model watermarking. Based on that framework, representative literature from the field is surveyed to illustrate the taxonomy. Finally, shortcomings and general limitations of existing approaches are discussed, and an outlook on future research directions is given

A combined clinical-biochemical scoring of the newborn. Results of the past four years

Peer Reviewe

On the buffer capacity of CO2-charged seawater used for carbonation and subsequent mineral sequestration

Successful mineral trapping of carbon dioxide faces the challenge of effectively titrating a CO2-charged acidic injection solution to pH conditions favorable to carbonate precipitation -using the rock as primary alkalinity source. To illustrate the magnitude of this task, buffer capacities of seawater solutions equilibrated with different partial pressure of CO2 are presented, under open and closed conditions. A number of mechanisms can be evoked to overcome the large buffer intensity of the injection fluid, including dilution, dissolution kinetic catalysis and increasing reaction temperature. Buffer capacity – pH plots are presented to aid in understanding how buffer capacity changes as a function of the presence and concentration of key solutes, like fluoride

Fusarium graminearum forms mycotoxin producing infection structures on wheat

<p>Abstract</p> <p>Background</p> <p>The mycotoxin producing fungal pathogen <it>Fusarium graminearum </it>is the causal agent of Fusarium head blight (FHB) of small grain cereals in fields worldwide. Although <it>F. graminearum </it>is highly investigated by means of molecular genetics, detailed studies about hyphal development during initial infection stages are rare. In addition, the role of mycotoxins during initial infection stages of FHB is still unknown. Therefore, we investigated the infection strategy of the fungus on different floral organs of wheat (<it>Triticum aestivum </it>L.) under real time conditions by constitutive expression of the <it>dsRed </it>reporter gene in a <it>TRI5prom</it>::<it>GFP </it>mutant. Additionally, trichothecene induction during infection was visualised with a green fluorescent protein (GFP) coupled <it>TRI5 </it>promoter. A tissue specific infection pattern and <it>TRI5 </it>induction were tested by using different floral organs of wheat. Through combination of bioimaging and electron microscopy infection structures were identified and characterised. In addition, the role of trichothecene production for initial infection was elucidated by a Δ<it>TRI5</it>-<it>GFP </it>reporter strain.</p> <p>Results</p> <p>The present investigation demonstrates the formation of foot structures and compound appressoria by <it>F. graminearum</it>. All infection structures developed from epiphytic runner hyphae. Compound appressoria including lobate appressoria and infection cushions were observed on inoculated caryopses, paleas, lemmas, and glumes of susceptible and resistant wheat cultivars. A specific trichothecene induction in infection structures was demonstrated by different imaging techniques. Interestingly, a Δ<it>TRI5</it>-<it>GFP </it>mutant formed the same infection structures and exhibited a similar symptom development compared to the wild type and the <it>TRI5prom</it>::<it>GFP </it>mutant.</p> <p>Conclusions</p> <p>The different specialised infection structures of <it>F. graminearum </it>on wheat florets, as described in this study, indicate that the penetration strategy of this fungus is far more complex than postulated to date. We show that trichothecene biosynthesis is specifically induced in infection structures, but is neither necessary for their development nor for formation of primary symptoms on wheat.</p

Geochemical modelling of petroleum well data from the Perth Basin. Implications for potential scaling during low enthalpy geothermal exploration from a hot sedimentary aquifer

Chemical analyses derived from petroleum exploration wells are notorious for their lack of key solute data and their potential to represent mixtures of reservoir and drilling fluids rather than pristine formation compositions. These drawbacks notwithstanding, they usually pose the only access to the reservoir geochemistry. Two literature protocols were applied to a dataset of incomplete major element analyses from 148 petroleum well samples from a database compilation of the Perth Basin whose deeper aquifers may serve as potential hot sedimentary aquifers for geothermal direct heat applications. The first protocol included a set of quality control criteria that reduced the number of relatively genuine formation well samples from the raw data pool by 71%. The remaining well analyses are invariably NaCl solutions of low to medium alkalinity and an ionic strength only occasionally reaching seawater salinity. The low amount of total dissolved solids indicates the absence of extended evaporites in the North Perth Basin and the prevalence of meteoric water infiltration and circulation at depths.The culled well samples underwent as a second protocol a forced equilibrium treatment to reconstruct in situ reservoir concentrations of missing elements (Si, Al, K), organic acid anions and non-carbonate alkalinity, and pH. The petroleum well samples were modelled to be in equilibrium with chalcedony (and kaolinite, albite, and paragonite) in the reservoir which yielded better convergence than using quartz instead. The derived formation temperatures correspond to geothermal gradients in the majority of cases between 25 and 35°C, in accord with literature findings. Those wells drilled to depth 90% of the wells from the calculated pH, either due to degassed CO2 or unaccounted acetate alkalinity. The wells were further modelled to be undersaturated with respect to amorphous silica and anhydrite and not likely to experience scaling of any of these two phases during geothermal production at depth <3800 m. For calcite, scaling predictions depend in how far bubbling and phase segregation can be suppressed. For the six different stratigraphies investigated here, calculated bubble points were low, indicating that pressurisation of the entire production and re-injection line seems viable.Based on a calcite growth model from the literature it is shown that, if bubble formation and concomitant carbonate flash scaling cannot be averted, the production well should be as shallow as the temperature requirements of the geothermal production allow for. This study promotes the application of readily accessible protocols and a scaling model to deep well samples that may otherwise appear to have little geochemical value because of the way the samples were collected and handled. After data culling and treatment, insights into the geochemistry and scaling potential of deep clastic formations of the North Perth Basin that may hold the potential for geothermal exploitation as hot sedimentary aquifers can be gained