Transport through anisotropic magnetic molecules with partially ferromagnetic leads: Spin-charge conversion and negative differential conductance

We theoretically investigate inelastic transport through anisotropic magnetic molecules weakly coupled to one ferromagnetic and one nonmagnetic lead. We find that the current is suppressed over wide voltage ranges due to spin blockade. In this system, spin blockade is associated with successive spin flips of the molecular spins and depends on the anisotropy energy barrier. This leads to the appearance of a window of bias voltages between the Coulomb blockade and spin blockade regimes where the current is large and to negative differential conductance at low temperatures. Remarkably, negative differential conductance is also present close to room temperature. Spin-blockade behavior is accompanied by super-Poissonian shot noise, like in nonmagnetic quantum dots. Finally, we show that the charge transmitted through the molecule between initial preparation in a certain spin state and infinite time very strongly depends on the initial spin state in certain parameter ranges. Thus the molecule can act as a spin-charge converter, an effect potentially useful as a read-out mechanism for molecular spintronics.Comment: 8 pages with 5 figures, version as publishe

Deep, Large Scale Surveys of Star Forming Regions throughout the Milky Way

Star formation and the processes involved are not only important to the Milky Way as an astronomical object, but are also crucial to understand our own origin. For instance, only lower-mass stars like our own Sun have supposedly a long enough lifetime to allow for the development of life, whereas high-mass stars are the major source of the heavy elements beyond iron, that are needed to form life as we know it. Therefore, understanding the influence of the Galactic environment on low- to high-mass star formation is crucial to understand our own place in the Galaxy. In order to obtain the most complete view on star formation throughout the Milky Way to date we use several different dust-continuum surveys (ATLASGAL, Hi-GAL, MSX and WISE) to obtain photometric data, and consecutively model the spectral energy distributions of the dense molecular clumps in which stars and star clusters form. From these we derive the physical properties such as dust temperatures, integrated fluxes and H2 peak column densities. We derive distances from line-of-sight velocities obtained from CO observations for the majority of the sources, allowing us to calculate clump masses and bolometric luminosities and analyse the properties of the sources in the context of their large scale environment. We started with a small subsample of the ATLASGAL survey, the ATLASGAL Top100, investigating the ~100 brightest and most massive clumps in 4 distinct evolutionary stages in the inner Galaxy (König et al. 2017). The methods developed for this sample were then applied to the full ATLASGAL compact source catalogue, investigating a complete sample of ~ 8000 sources located mostly in the inner part of the Milky Way (Urquhart et al. 2018). Finally, the analysis is extended to a sample of sources located in the southern outer Galaxy, unrevealing its structure and investigating star formation properties out to the edge of the Milky Way. With samples for the inner and outer Galaxy at hand, we investigate the star formation properties of the sources with respect to their evolutionary phase, their dependence on the distance to the Galactic centre and the influence of large-scale structures like the spiral arms or the second largest expanding supershell of the Galaxy. We established an evolutionary sequence based on the dust spectral energy distributions. Using dust continuum emission we are able to assign an evolutionary phase to individual clumps, and statistically analyse the physical properties, finding the dust temperature, bolometric luminosity and luminosity-to-mass ratio to increase over time. Using this classification scheme for the ATLASGAL sample we were furthermore able to calculate statistical lifetimes, finding that the quiescent stage is indeed very short (4 years) for the most massive (>10,000Msun) clumps. We find the clumps' physical properties to vary significantly with Galactocentric distance. The dust temperature increases towards the outer Galaxy, whereas the average clump masses, bolometric luminosities and peak column densities significantly drop by almost an order of magnitude within just a few kiloparsec around the solar circle. As also the gas-to-dust ratio increases and the metallicity decreases in the outer Galaxy, we attribute the increased temperatures to a combination of less effective cooling and lower shielding against the interstellar radiation field due to the lower column densities. In contrast, we find the star formation activity as indicated by the luminosity-to-mass ratio to stay constant on kiloparsec scales throughout the Milky Way. Furthermore, we find the clump masses to be independent of the evolutionary stage indicated by the dust temperature, showing that once a clump begins to collapse, the evolution is largely independent of its large-scale environment. This is further supported by the fact that we find no influence of the spiral arms on the physical parameters and star formation activity of the dust clumps; they only seem to be responsible for organizing the interstellar material into clumps

Inequality-Minimization with a Given Public Budget

We solve the problem of a social planner who seeks to minimize inequality via transfers with a fixed public budget in a distribution of exogenously given incomes. The appropriate solution method depends on the objective function: If it is convex, as in the case of the absolute mean deviation, it can be solved by an interior-point algorithm. If it is quasiconvex, as in case of the Gini coefficient, the bisection method can be used. We implement the procedures using artificial and real-world data, and show that the optimal transfer scheme need not comply with a transfer scheme that perfectly equalizes incomes at the bottom of the distribution

Evidence from Germany

We empirically investigate the distributional consequences of the Riester scheme, the main private pension subsidization program in Germany. We find that 38% of the aggregate subsidy accrues to the top two deciles of the population, but only 7.3% to the bottom two. Nonetheless the Riester scheme is almost distributionally neutral when looking at standard inequality measures. This is due to two offsetting effects: a progressive one stemming from the subsidy schedule and a regressive one from voluntary participation. Regressions of the participation decision suggest that a high level of household wealth significantly increases the probability of benefiting from the Riester scheme

Systems-Biology Approaches to Discover Anti-Viral Effectors of the Human Innate Immune Response

Virus infections elicit an immediate innate response involving antiviral factors. The activities of some of these factors are, in turn, blocked by viral countermeasures. The ensuing battle between the host and the viruses is crucial for determining whether the virus establishes a foothold and/or induces adaptive immune responses. A comprehensive systems-level understanding of the repertoire of anti-viral effectors in the context of these immediate virus-host responses would provide significant advantages in devising novel strategies to interfere with the initial establishment of infections. Recent efforts to identify cellular factors in a comprehensive and unbiased manner, using genome-wide siRNA screens and other systems biology “omics” methodologies, have revealed several potential anti-viral effectors for viruses like Human immunodeficiency virus type 1 (HIV-1), Hepatitis C virus (HCV), West Nile virus (WNV), and influenza virus. This review describes the discovery of novel viral restriction factors and discusses how the integration of different methods in systems biology can be used to more comprehensively identify the intimate interactions of viruses and the cellular innate resistance

Measurements of Streams Agitated by Fluid Loaded SAW-devices Using a Volumetric 3-component Measurement Technique (V3V)

Utilizing surface acoustic waves (SAW) to induce tailored fluid motion via the acoustic streaming requires detailed knowledge about the acoustic bulk wave excitation. For the first time, the Defocus Digital Particle Image Velocimetry is used to measure the fluid motion originating from a fluid loaded SAW-device. With this flow measurement technique, the acoustic streaming-induced fluid motion can be observed volumetrically, which is attractive not only for application, but also for simulation in order to gain deeper insights regarding three-dimensional acoustic effects

Massive and low-mass protostars in massive "starless" cores

The infrared dark clouds (IRDCs) G11.11$-$0.12 and G28.34$+$0.06 are two of the best-studied IRDCs in our Galaxy. These two clouds host clumps at different stages of evolution, including a massive dense clump in both clouds that is dark even at 70 and 100$\mu$m. Such seemingly quiescent massive dense clumps have been speculated to harbor cores that are precursors of high-mass stars and clusters. We observed these two "prestellar" regions at 1mm with the Submillimeter Array (SMA) with the aim of characterizing the nature of such cores. We show that the clumps fragment into several low- to high-mass cores within the filamentary structure of the enveloping cloud. However, while the overall physical properties of the clump may indicate a starless phase, we find that both regions host multiple outflows. The most massive core though 70 $\mu$m dark in both clumps is clearly associated with compact outflows. Such low-luminosity, massive cores are potentially the earliest stage in the evolution of a massive protostar. We also identify several outflow features distributed in the large environment around the most massive core. We infer that these outflows are being powered by young, low-mass protostars whose core mass is below our detection limit. These findings suggest that low-mass protostars have already formed or are coevally formed at the earliest phase of high-mass star formation.Comment: in print at A&

Reverse shoulder arthroplasty leads to significant biomechanical changes in the remaining rotator cuff

Objective: after reverse shoulder arthroplasty (RSA) external and internal rotation will often remain restricted. A postoperative alteration of the biomechanics in the remaining cuff is discussed as a contributing factor to these functional deficits.Methods: in this study, muscle moment arms as well as origin-to-insertion distance (OID) were calculated using three-dimensional models of the shoulder derived from CT scans of seven cadaveric specimens.Results: moment arms for humeral rotation are significantly smaller for the cranial segments of SSC and all segments of TMIN in abduction angles of 30 degrees and above (p ≤ 0.05). Abduction moment arms were significantly decreased for all segments (p ≤ 0.002). OID was significantly smaller for all muscles at the 15 degree position (p ≤ 0.005), apart from the cranial SSC segment.Conclusions: reduced rotational moment arms in conjunction with the decrease of OID may be a possible explanation for the clinically observed impaired external and internal rotation

Transient Experimental and 3D-FSI Investigation of Flapper Valve Dynamics for Refrigerant Compressors

The design of the valves for refrigerant compressors has a distinct influence on the efficiency of the refrigeration cycle. In order to predict the valve behavior for compressor optimization, flow characteristics and valve system dynamics are key factors. State of the art valve model approaches have to date ignored the retainer deflection and the influence of contact effects on fluid-structure interaction behavior. With this fact in mind, experimental valve lift investigations by means of laser vibrometry measurements were performed. In order to determine dynamic flapper valve characteristics, oscillation frequency analyses and numerical natural frequency analyses for free oscillation of the flapper valve were carried out. Additionally this paper presents an extended three-dimensional numerical discharge valve model containing a fully-coupled fluid-structure interaction (FSI) approach. The two-way mechanical coupling is carried out by a commercial CFD code combined with a commercial FEA package. The numerical results are validated using the presented experimental transient results and compared to a lumped 1D valve model. The numerical 3D-FSI results show good agreement with the experimental results and allow for further investigations of multiphysics phenomena such as adhesive effects on the flapper valve

The personality traits of self-made and inherited millionaires

Very wealthy people influence political and societal processes by wielding their economic power through foundations, lobbying groups, media campaigns, as investors and employers. Because personality shapes goals, attitudes, and behaviour, it is important to understand the personality traits that characterize the rich. We used representative survey data to construct two large samples, one from the general population and one consisting of individuals with at least 1 million euros in individual net wealth, to analyse what personality traits characterize the wealthy and why their traits differ from those of the general population. High wealth was associated with higher Risk tolerance, Emotional Stability, Openness, Extraversion, and Conscientiousness. This “rich” personality profile was more prominent among individuals who had accumulated wealth through their own efforts (“self-mades”) than among individuals who had been born into wealth (“inheritors”). Thus, our evidence is suggestive of a unique configuration of personality traits contributing to self-made millionaires’ economic success