Convective Cold Pools over the Atlas Mountains and Their Influence on the Saharan Heat Low

The West African Monsoon (WAM) and its representation in numerical models are strongly influenced by the Saharan Heat Low (SHL), a low-pressure system driven by radiative heating over the central Sahara and ventilated by the cold and moist inflow from adjacent oceans. It has recently been shown that a significant part of the southerly moisture flux into the SHL originates from convective cold pools over the Sahel. These density currents driven by evaporation of rain are largely absent in models with parameterized convection. This crucial issue has been hypothesized to contribute to the inability of many climate models to reproduce the variability of the WAM. Here, the role of convective cold pools approaching the SHL from the Atlas Mountains, which are a strong orographic trigger for deep convection in Northwest Africa, is analyzed. Knowledge about the frequency of these events, as well as their impact on large-scale dynamics, is required to understand their contribution to the variability of the SHL and to known model uncertainties. The first aspect is addressed through the development of an objective and automated method for the generation of multi-year climatologies not available before. The algorithm combines freely available standard surface observations with satellite microwave data. Representativeness of stations and influence of their spatial density are addressed by comparison to a satellite-only climatology. Applying this algorithm to data from automated weather stations and manned synoptic stations in and south of the Atlas Mountains reveals the frequent occurrence. On the order of 6 events per month are detected from May to September when the SHL is in its northernmost position. The events tend to cluster into several-days long convectively active periods, often with strong events on consecutive days. This study is the first to diagnose dynamical impacts of such periods on the SHL, based on simulations of two example cases using the Weather Research and Forecast (WRF) model at convection-permitting resolution. Sensitivity experiments with artificially removed cold pools as well as different resolutions and parameterizations are conducted. Results indicate increases in surface pressure of more than 1 hPa and significant moisture transports into the desert over several days. This moisture affects radiative heating and thus the energy balance of the SHL. Even though cold pool events north of the SHL are less frequent when compared to their Sahelian counterparts, it is shown that they gain importance due to their temporal clustering on synoptic timescale. Together with studies focusing on the Sahel, this work emphasizes the need for improved parameterization schemes for deep convection in order to produce more reliable climate projections for the WAM

Understanding the dependence of mean precipitation on convective treatment and horizontal resolution in tropical aquachannel experiments

The Intertropical Convergence Zone (ITCZ) is a key circulation and precipitation feature in the tropics. There has been a large spread in the representation of the ITCZ in global weather and climate models for a long time, the reasons for which remain unclear. This paper presents a novel approach with which we disentangle different physical processes responsible for the changeable behavior of the ITCZ in numerical models. The diagnostic tool is based on a conceptual framework developed by Emanuel (2019) and allows for physically consistent estimates of convective mass flux and precipitation efficiency for simulations with explicit and parameterized convection. We apply our diagnostic tool to a set of tropical aquachannel experiments using the ICOsahedral Nonhydrostatic (ICON) model with horizontal grid spacings of 13 and 5 km and with various representations of deep and shallow convection. The channel length corresponds to the Earth\u27s circumference and has rigid walls at 30∘ N/S. Zonally symmetric sea surface temperatures are prescribed. All experiments simulate an ITCZ at the Equator coinciding with the ascending branch of the Hadley circulation and descending branches at 15∘ N/S with subtropical jets and easterly trade wind belts straddling the ITCZ. With explicit deep convection, however, rainfall in the ITCZ increases and the Hadley circulation becomes stronger. Increasing horizontal resolution substantially reduces the rainfall maximum in the ITCZ, while the strength of the Hadley circulation changes only marginally. Our diagnostic framework reveals that boundary-layer quasi-equilibrium (BLQE) is a key to physically understanding those differences. At 13 km, enhanced surface enthalpy fluxes with explicit deep convection are balanced by increased convective downdrafts. As precipitation efficiency is hardly affected, convective updrafts and rainfall increase. The surface enthalpy fluxes are mainly controlled by mean surface winds, closely linked to the Hadley circulation. These links also help understand rainfall differences between different resolutions. At 5 km, the wind–surface-fluxes–convection relation holds, but additionally explicit convection dries the mid-troposphere, which increases the import of air with lower moist static energy into the boundary layer, thereby enhancing surface fluxes. Overall, the different model configurations create little variations in precipitation efficiency and radiative cooling, the effects of which are compensated for by changes in dry stability. The results highlight the utility of our diagnostic tool to pinpoint processes important for rainfall differences between models, suggesting applicability for climate model intercomparison projects

Mosquito breeding site water temperature observations and simulations towards improved vector-borne disease models for Africa

An energy budget model is developed to predict the water temperature of typical mosquito larval developmental habitats. It assumes a homogeneous mixed water column driven by empirically derived fluxes. The model shows good agreement at both hourly and daily time scales with 10-min temporal resolution observed water temperatures, monitored between June and November 2013 within a peri-urban area of Kumasi, Ghana. There was a close match between larvae development times calculated using either the model-derived or observed water temperatures. The water temperature scheme represents a significant improvement over assuming the water temperature to be equal to air temperature. The energy budget model requires observed minimum and maximum temperatures, information that is generally available from weather stations. Our results show that hourly variations in water temperature are important for the simulation of aquatic-stage development times. By contrast, we found that larval development is insensitive to sub-hourly variations. Modelling suggests that in addition to water temperature, an accurate estimation of degree-day development time is very important to correctly predict the larvae development times. The results highlight the potential of the model to predict water temperature of temporary bodies of surface water. Our study represents an important contribution towards the improvement of weather-driven dynamical disease models, including those designed for malaria early forecasting systems

Mosquito breeding site water temperature observations and simulations towards improved vector-borne disease models for Africa

An energy budget model is developed to predict the water temperature of typical mosquito larval developmental habitats. It assumes a homogeneous mixed water column driven by empirically derived fluxes. The model shows good agreement at both hourly and daily time scales with 10-min temporal resolution observed water temperatures, monitored between June and November 2013 within a peri-urban area of Kumasi, Ghana. There was a close match between larvae development times calculated using either the model-derived or observed water temperatures. The water temperature scheme represents a significant improvement over assuming the water temperature to be equal to air temperature. The energy budget model requires observed minimum and maximum temperatures, information that is generally available from weather stations. Our results show that hourly variations in water temperature are important for the simulation of aquatic-stage development times. By contrast, we found that larval development is insensitive to sub-hourly variations. Modelling suggests that in addition to water temperature, an accurate estimation of degree-day development time is very important to correctly predict the larvae development times. The results highlight the potential of the model to predict water temperature of temporary bodies of surface water. Our study represents an important contribution towards the improvement of weather-driven dynamical disease models, including those designed for malaria early forecasting systems

Evaluation of machine-learning methods for ligand-based virtual screening

Machine-learning methods can be used for virtual screening by analysing the structural characteristics of molecules of known (in)activity, and we here discuss the use of kernel discrimination and naive Bayesian classifier (NBC) methods for this purpose. We report a kernel method that allows the processing of molecules represented by binary, integer and real-valued descriptors, and show that it is little different in screening performance from a previously described kernel that had been developed specifically for the analysis of binary fingerprint representations of molecular structure. We then evaluate the performance of an NBC when the training-set contains only a very few active molecules. In such cases, a simpler approach based on group fusion would appear to provide superior screening performance, especially when structurally heterogeneous datasets are to be processed

Spatiotemporal Differences in Gene Expression Between Motor and Sensory Autografts and Their Effect on Femoral Nerve Regeneration in the Rat

To improve the outcome after autologous nerve grafting in the clinic, it is important to understand the limiting variables such as distinct phenotypes of motor and sensory Schwann cells. This study investigated the properties of phenotypically different autografts in a 6 mm femoral nerve defect model in the rat, where the respective femoral branches distally of the inguinal bifurcation served as homotopic, or heterotopic autografts. Axonal regeneration and target reinnervation was analyzed by gait analysis, electrophysiology, and wet muscle mass analysis. We evaluated regeneration-associated gene expression between 5 days and 10 weeks after repair, in the autografts as well as the proximal, and distal segments of the femoral nerve using qRT-PCR. Furthermore we investigated expression patterns of phenotypically pure ventral and dorsal roots. We identified highly significant differences in gene expression of a variety of regeneration-associated genes along the central – peripheral axis in healthy femoral nerves. Phenotypically mismatched grafting resulted in altered spatiotemporal expression of neurotrophic factor BDNF, GDNF receptor GFRα1, cell adhesion molecules Cadm3, Cadm4, L1CAM, and proliferation associated Ki67. Although significantly higher quadriceps muscle mass following homotopic nerve grafting was measured, we did not observe differences in gait analysis, and electrophysiological parameters between treatment paradigms. Our study provides evidence for phenotypic commitment of autologous nerve grafts after injury and gives a conclusive overview of temporal expression of several important regeneration-associated genes after repair with sensory or motor graft

Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches

The following article appeared in Applied Physics Letters 103.16 (2013): 164105 and may be found at http://scitation.aip.org/content/aip/journal/apl/100/26/10.1063/1.4729825The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each particle interaction, providing excellent discrimination between electron and nuclear recoils, and between surface and interior events. Surface event rejection capabilities were tested with two 210 Pb sources producing ∼130 beta decays/hr. In ∼800 live hours, no events leaked into the 8–115 keV signal region, giving upper limit leakage fraction 1.7 × 10−5 at 90% C.L., corresponding to < 0.6 surface event background in the future 200-kg SuperCDMS SNOLAB experiment.This work is supported in part by the National Science Foundation (Grant Nos. AST-9978911, NSF-0847342, PHY-1102795,NSF-1151869, PHY-0542066, PHY-0503729, PHY-0503629, PHY-0503641, PHY-0504224, PHY-0705052,PHY-0801708, PHY-0801712, PHY-0802575, PHY-0847342, PHY-0855299, PHY-0855525, and PHY-1205898), by the Department of Energy (Contract Nos. DE-AC03-76SF00098, DE-FG02-92ER40701, DE-FG02-94ER40823,DE-FG03-90ER40569, DE-FG03-91ER40618, and DESC0004022),by NSERC Canada (Grant Nos. SAPIN 341314 and SAPPJ 386399), and by MULTIDARK CSD2009-00064 and FPA2012-34694. Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359, while SLAC is operated under Contract No. DE-AC02-76SF00515 with the United States Department of Energy

A Neutrophil Phenotype Model for Extracorporeal Treatment of Sepsis

Neutrophils play a central role in eliminating bacterial pathogens, but may also contribute to end-organ damage in sepsis. Interleukin-8 (IL-8), a key modulator of neutrophil function, signals through neutrophil specific surface receptors CXCR-1 and CXCR-2. In this study a mechanistic computational model was used to evaluate and deploy an extracorporeal sepsis treatment which modulates CXCR-1/2 levels. First, a simplified mechanistic computational model of IL-8 mediated activation of CXCR-1/2 receptors was developed, containing 16 ODEs and 43 parameters. Receptor level dynamics and systemic parameters were coupled with multiple neutrophil phenotypes to generate dynamic populations of activated neutrophils which reduce pathogen load, and/or primed neutrophils which cause adverse tissue damage when misdirected. The mathematical model was calibrated using experimental data from baboons administered a two-hour infusion of E coli and followed for a maximum of 28 days. Ensembles of parameters were generated using a Bayesian parallel tempering approach to produce model fits that could recreate experimental outcomes. Stepwise logistic regression identified seven model parameters as key determinants of mortality. Sensitivity analysis showed that parameters controlling the level of killer cell neutrophils affected the overall systemic damage of individuals. To evaluate rescue strategies and provide probabilistic predictions of their impact on mortality, time of onset, duration, and capture efficacy of an extracorporeal device that modulated neutrophil phenotype were explored. Our findings suggest that interventions aiming to modulate phenotypic composition are time sensitive. When introduced between 3–6 hours of infection for a 72 hour duration, the survivor population increased from 31% to 40–80%. Treatment efficacy quickly diminishes if not introduced within 15 hours of infection. Significant harm is possible with treatment durations ranging from 5–24 hours, which may reduce survival to 13%. In severe sepsis, an extracorporeal treatment which modulates CXCR-1/2 levels has therapeutic potential, but also potential for harm. Further development of the computational model will help guide optimal device development and determine which patient populations should be targeted by treatment

Transforming Thalia - refurbishment of old urban shopping street as an example of the Thaliastrasse. Limits and possibilities of BIDs (buisness improvement district)

Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersAusgehend von einer internationalen, zur Zeit noch vorwiegend im angloamerikanischen Trend der 5. Generation des Shopping-Centers namens Urban Redevelopment versucht meine Diplomarbeit die Möglichkeiten zu betrachten alte Wiener Einkaufsstrassen wieder zu revitalisieren.Charakteristika der Urban redevelopment sind überbreite Bordsteine um die Bebauung herum, nicht geschlossene Innenbereiche, sondern überdachte Außenräume. Eine Kombination von Einzelhandel, Gastronomie und Unterhaltung ersetzt fehlende Stadtkerne bzw. im besten Fall bildet neue Kerngebiete eines alten Stadtgefüges aus. Beginnend mit der 1.Generation von Shopping Mals dem klassischen Kaufhaus auf primär Standorten, als Beispiel das Haas-Haus, die 2. Generation dem Shopping am Stadtrand (die SCS), innerstädtische Standorte in Form von Corporate-Identity (Steffl) folgen unterschiedliche Entwicklungen in den 90-er Jahren allem voran der Urban Entertainment Center (UEC), das als Weiterentwicklung des Einzelhandelsimmobilientyps des Einkaufszentrums gesehen wird, als eines von vielen Beispielen das Donauzentrum folgt die oben genannte 5. Generation das meist autofreie Lifestyle Center als Urban Redevelopment. Als Vorreiter Beispiel ist hier Liverpool 1 in England zu nennen. Alte Strukturen werden aufgenommen, aufgewertet und dadurch neue alte Zentren ausgebildet. Der Vorreiter des heutigen Shoppingcenter gilt Victor Gruen der schon in den 50-er Jahren versucht hat Einkaufszentren zu Entwickeln, die wie eine verbesserte Downtown konzipiert werden. Diese wurde nie als reine Geschäftsstrassen fungieren, sondern eher innerstädtische europäisches Flair haben. In Österreich gilt er als "Vater" der ersten großen Fußgängerzone, die 1970 trotz heftiger Kritik testweise in der Wiener Kärntner Strasse eingerichtet wurde. Bekanntes Argument von ihm in dieser Sache war:"Autos kaufen nichts".Als Case Study Modell wird die 2.3 km lange Thaliastrasse im Bereich zwischen dem Lerchenfeldergürtel bis hin zur Maroltingergasse betrachtet. Interessant an der Situation der Thaliastrasse ist, dass diese schon jetzt eine relativ hohe Frequenz bereits hat und zwei bestehende U-Bahn Linien als "Hundeknochen" funktionieren könnte, aber trotzdem ein hoher Leerstand an Gassenlokalen vorhanden ist. Derzeitige Stärken sind die hohe Zentralität, gute Verkehrsanbindung und breite Branchenstreuung während dessen die Nachteile die unterdurchschnittliche Kaufkraft, Unterbrechungen durch unattraktive Plätze und Leerflächen und das Fehlen von Großprojekten sind.15

Evaluierung von WEB 2.0 Anwendungen zur Vermarktung im Immobilienbereich unter besonderen Berücksichtigung von Österreich im Vergleich zu den USA

Die Kernidee des Web 2.0 war es, den Konsumenten einen Raum zu geben, um sich zu präsentieren und auch, um miteinander kommunizieren zu können. Im Rahmen des Web 2.0 entwickelte sich das Internet weg von einer starren Informationsquelle und wurde zu einer Art interaktivem Mitmachmedium. So konnten Projekte, wie Wikipedia oder Facebook in kürzester Zeit Millionen von Nutzern verbuchen. Viele der neuen Tools wie Instagram, Snapchat und Twitter werden am Maklern in den USA als bidirektionales Kommunikationsinstrument mit den potentiellen Kunden gesehen. Die Netzwerke werden mehr als nur für die reine Imagepflege der Unternehmen gesehen und bieten darüber hinaus eine Kommunikationsplattform mit Kunden unabhängig von Zeit und Ort und überwinden alle Mikro und Makroebenen der Interaktion. Neue Absatzmärkte werden kostengünstig und ressourcensparend erschlossen und alte überholte und ineffiziente Arbeitsabläufe abgelegt. Vor allem im urbanen Kontext verwenden die Makler Tools wie Instagram und Snapchat um ihre Immobilien schnell zu promoten. Umsätze der Makler sind auch nach Bereinigung durch das BIP und Kaufpreisindex Anpassung signifikant höher als in Österreich. Abschlüsse über soziale Netzwerke nehmen signifikant zu und bilden derzeit 5% ihres Umsatzes und zusammen mit der klassischen Homepage, jedoch immer auf den Stand des WEB2.0 gebracht sogar 20% des Umsatzes. Fast jede Webseite der Makler hat Verknüpfungen zu allen derzeit Relevanten sozialen Netzwerken. Die digitale Metamorphose schreitet voran; wird sich der Markt durch Evolution - vor allem technologische- oder revolutioniert, in Form von soziotechnischen (Web 2.0) - Entwicklungen wegrationalisiert bzw. verändert. Wie halten die österreichischen Makler den Innovationsdruck stand und wann geben sie nach.9