On the trails of Josias Braun-Blanquet : changes in the grasslands of the inneralpine dry valleys during the last 70 years. First results from the 11th EDGG Field Workshop in Austria

The 11th EDGG Field Workshop was held from 6 to 13 July 2018 in Austria. Its aim was to revisit dry grasslands in the inneralpine dry valleys of Austria that were investigated in the late 1950s by Braun-Blanquet and to collect high-quality biodiversity data from these. Sampling was carried out in the Styrian Mur Valley, the Virgen Valley in East Tyrol, the Upper Inn Valley in the Austrian Eastern Alps, and Griffen in Carinthia. In total, we sampled 15 EDGG biodiversity plots and 37 additional 10 m2 plots. Butterfly data were record-ed in four biodiversity plots and two additional plots. We found maximum richness values of 49, 68 and 95 vascular plant species on 1, 10 and 100 m², while the corresponding values for the complete terrestrial vegetation were 56, 73 and 106 species. Maximum butterfly richness was 19, but it was in general quite low, and generalists dominated. Some of the areas originally studied by Braun-Blanquet were no longer dry grasslands and only a few sites remained largely unchanged. Detrended Correspondence Analysis (DCA) showed profound changes between the old (1950s and 1980s) and our current plots. Without grazing or other human land management activities, only very small cores of rocky dry grassland could survive in the comparatively humid Austrian inneralpine valleys. Finally, the sampled data raise questions about the syntaxonomic position of some of the grasslands, which needs to be addressed in a more comprehensive study, which is planned as the next step

Old folks and spoiled brats : Why the baby boomers' saving crisis need not be that bad

We study the impact of an anticipated "baby boom" in an overlapping generations economy. The rise of the working population lowers the wage, and the high demand for assets causes a rise in the price of capital which will be reversed when the baby boomers leave the work-force. However, the swings in factor prices are substantially dampened if we allow for more than two generations, endogenous labor supply, and convex capital adjustment costs. This is mainly due to the intertemporal shifts in labor market participation that can be observed if agents work for more than one period. Optimal saving and labor supply decisions of the baby boomers' preceding and subsequent generations partly offset the impact of the unfavorable demographic shock. Accordingly, the impact of a baby boom on the welfare of different generations crucially depends on the elasticity of labor supply.baby boom; asset prices; labour market adjustments

A heterogeneous agents equilibrium model for the term structure of bond market liquidity

We analyze the impact of market frictions on trading volume and liquidity premia of finite maturity assets when investors differ in their trading needs. Our equilibrium model generates a clientele effect (frequently trading investors only hold short-term assets) and predicts i) a hump-shaped relation between trading volume and maturity, ii) lower trading volumes of older compared to younger assets, iii) an increasing liquidity term structure from ask prices, iv) a decreasing or U-shaped liquidity term structure from bid prices, and v) spill-overs of liquidity from short-term to long-term maturities. Empirical tests for U.S. corporate bonds support our theoretical predictions

Engineering Graph States of Atomic Ensembles by Photon-Mediated Entanglement

Graph states are versatile resources for quantum computation and quantum-enhanced measurement. Their generation illustrates a high level of control over entanglement. We report on the generation of continuous-variable graph states of atomic spin ensembles, which form the nodes of the graph. The edges represent the entanglement structure, which we program by combining global photon-mediated interactions in an optical cavity with local spin rotations. By tuning the entanglement between two subsystems, we either localize correlations within each subsystem or enable Einstein-Podolsky-Rosen steering. We further engineer a four-mode square graph state, highlighting the flexibility of our approach. Our method is scalable to larger and more complex graphs, laying groundwork for measurement-based quantum computation and advanced protocols in quantum metrology

Cold-atom quantum simulators of gauge theories

Gauge theories represent a fundamental framework underlying modern physics, constituting the basis of the Standard Model and also providing useful descriptions of various phenomena in condensed matter. Realizing gauge theories on accessible and tunable tabletop quantum devices offers the possibility to study their dynamics from first principles time evolution and to probe their exotic physics, including that generated by deviations from gauge invariance, which is not possible, e.g., in dedicated particle colliders. Not only do cold-atom quantum simulators hold the potential to provide new insights into outstanding high-energy and nuclear-physics questions, they also provide a versatile tool for the exploration of topological phases and ergodicity-breaking mechanisms relevant to low-energy many-body physics. In recent years, cold-atom quantum simulators have demonstrated impressive progress in the large-scale implementation of $1+1$D Abelian gauge theories. In this Review, we chronicle the progress of cold-atom quantum simulators of gauge theories, highlighting the crucial advancements achieved along the way in order to reliably stabilize gauge invariance and go from building blocks to large-scale realizations where \textit{bona fide} gauge-theory phenomena can be probed. We also provide a brief outlook on where this field is heading, and what is required experimentally and theoretically to bring the technology to the next level by surveying various concrete proposals for advancing these setups to higher spatial dimensions, higher-spin representations of the gauge field, and non-Abelian gauge groups.Comment: $24$ pages, $6$ figures, $2$ boxe

BackWards - Unveiling the brain's topographic organization of paraspinal sensory input

Cortical reorganization and its potential pathological significance are being increasingly studied in musculoskeletal disorders such as chronic low back pain (CLBP) patients. However, detailed sensory-topographic maps of the human back are lacking, and a baseline characterization of such representations, reflecting the somatosensory organization of the healthy back, is needed before exploring potential sensory map reorganization. To this end, a novel pneumatic vibrotactile stimulation method was used to stimulate paraspinal sensory afferents, while studying their cortical representations in unprecedented detail. In 41 young healthy participants, vibrotactile stimulations at 20 Hz and 80 Hz were applied bilaterally at nine locations along the thoracolumbar axis while functional magnetic resonance imaging (fMRI) was performed. Model-based whole-brain searchlight representational similarity analysis (RSA) was used to investigate the organizational structure of brain activity patterns evoked by thoracolumbar sensory inputs. A model based on segmental distances best explained the similarity structure of brain activity patterns that were located in different areas of sensorimotor cortices, including the primary somatosensory and motor cortices and parts of the superior parietal cortex, suggesting that these brain areas process sensory input from the back in a "dermatomal" manner. The current findings provide a sound basis for testing the "cortical map reorganization theory" and its pathological relevance in CLBP

Dose-dependent dominance : How cell densities design stromal cell functions during soft tissue healing

Regular soft tissue healing relies on the well‐organized interaction of different stromal cell types with endothelial cells. However, spatiotemporal conditions might provoke high densities of one special stromal cell type, potentially leading to impaired healing. Detailed knowledge of the functions of rivaling stromal cell types aiming for tissue contraction and stabilization as well as vascular support is mandatory. By the application of an in vitro approach comprising the evaluation of cell proliferation, cell morphology, myofibroblastoid differentiation, and cytokine release, we verified a density‐dependent modulation of these functions among juvenile and adult fibroblasts, pericytes, and adipose‐derived stem cells during their interaction with microvascular endothelial cells in cocultures. Results indicate that juvenile fibroblasts rather support angiogenesis via paracrine regulation at the early stage of healing, a role potentially compromised in adult fibroblasts. In contrast, pericytes showed a more versatile character aiming at angiogenesis, vessel stabilization, and tissue contraction. Such a universal character was even more pronounced among adipose‐derived stem cells. The explicit knowledge of the characteristic functions of stromal cell types is a prerequisite for the development of new analytical and therapeutic approaches for impaired soft tissue healing. The present study delivers new considerations concerning the roles of rivaling stromal cell types within a granulation tissue, pointing to extraordinary properties of pericytes and adipose‐derived stem cells

Zweite digitale Welle im Forschungsmanagement: Strukturbedingungen und Orientierungen an niederösterreichischen Wissenschaftsinstitutionen

Das Sammeln, Aufbereiten und Bilanzieren von Informationen über wissenschaftliche Aktivitäten ist eine zentrale Aufgabe des Forschungsmanagements auf allen Ebenen. Diese Aufgabe unterstützen Forschungsinformationssysteme (FIS). Obwohl FIS zunehmend zu einem zentralen Element der IT-Ökologie des Wissenschaftssystems geworden sind, fehlen noch immer belastbare empirische Daten darüber, wie verbreitet Forschungsinformationssysteme überhaupt sind und ob es dahingehend Unterschiede zwischen unterschiedlichen Typen und Größen von Forschungseinrichtungen gibt. Aufbauend auf einer telefonischen Organisationsbefragung in Niederösterreich diagnostizieren wir eine zweite digitale Welle des Forschungsmanagements. Insbesondere sind avancierte Forschungsinformationssysteme auf dem Vormarsch. Es gibt eine starke Wandlungsdynamik. Allerdings bringt die Welle auch Tiefenströmungen mit sich, die auf eine Fragmentierung in der Digitalisierung des Forschungsmanagements hinweisen und für öffentliche Projekte von großer Bedeutung sind, will man Nachteile für kleine Forschungseinrichtungen nicht reproduzieren.Collecting, processing and balancing information about research activities is a central task of research management at all levels. Research information systems support this task. Although the topic is increasingly discussed, there is still a lack of robust empirical data on the spread of research information systems among research institutions and what differences there are between different types and sizes of research institutions. Building on a telephone survey of organizations in Lower Austria, we diagnose a second digital wave of research management. Advanced research information systems are on the rise and there is a strong dynamic of digital transformation. However, the wave also brings deep currents that point to a fragmentation of the field. These are of great importance for public projects, if one does not want to reproduce disadvantages for small research institutions