3,254 research outputs found
Adaptation of Binaural Processing in the Adult Brainstem Induced by Ambient Noise
Interaural differences in stimulus intensity and timing are major cues for sound localization. In mammals, these cues are first processed in the lateral and medial superior olive by interaction of excitatory and inhibitory synaptic inputs from ipsi- and contralateral cochlear nucleus neurons. To preserve sound localization acuity following changes in the acoustic environment, the processing of these binaural cues needs neuronal adaptation. Recent studies have shown that binaural sensitivity adapts to stimulation history within milliseconds, but the actual extent of binaural adaptation is unknown. In the current study, we investigated long-term effects on binaural sensitivity using extracellular in vivo recordings from single neurons in the dorsal nucleus of the lateral lemniscus that inherit their binaural properties directly from the lateral and medial superior olives. In contrast to most previous studies, we used a noninvasive approach to influence this processing. Adult gerbils were exposed for 2 weeks to moderate noise with no stable binaural cue. We found monaural response properties to be unaffected by this measure. However, neuronal sensitivity to binaural cues was reversibly altered for a few days. Computational models of sensitivity to interaural time and level differences suggest that upregulation of inhibition in the superior olivary complex can explain the electrophysiological data
A simultaneous two-dimensionally constraint disaggregate trip generation, distribution and mode choice model - Theory and application for a Swiss national model
The Swiss federal government has asked the IVT, ETH Zürich in collaboration with the TU Dresden and Emch+Berger, Zürich to estimate origin-destination matrices by mode and purpose for the year 2000. The zoning system employing about 3’000 zones of very uneven size required a solution algorithm which is fast, but also able to model generation, distribution and mode choice simultaneously, while addressing the different data availability for traffic within, destined for and passing through the country. The EVA algorithm developed by Lohse (1997) was adapted for this purpose. The key proper-ties of the algorithm are its disaggregate description of demand, its use of appropriate logit-type models for the demand distribution, while maintaining the known marginal distributions of the matrices generated. This last point is of particular importance in a large scale planning applica-tion such as the one at hand. The algorithm calculates trip production and attractions by zone using activity pairs. The 17 ac-tivity pairs distinguished are the combinations of two activities, such as home-work or work-leisure. The relevant daily rates are derived for each of the 17 activity pairs from the 2000 Swiss National Travel Survey (Bundesamt für Statistik and Bundesamt für Raumentwicklung, 2001). The zonal attractivity is defined separately for each trip purpose. In addition to the common variables, such as employment or population, detailed descriptions of education places, shop-ping or leisure facilities, overnight accommodations, shopping centres etc. are employed (see Tschopp, Keller and Axhausen, 2003 for the data). The combined destination and mode choice models estimated for the different traveller types and activity pairs are based on the Swiss National Travel survey (RP data), but incorporates re-sults from a prior SP study on mode and route choice (Vrtic and Axhausen, 2004). The different zone sizes and the different levels of data available required the formulation of new additional models for the transit traffic passing through Switzerland and the traffic originat-ing outside, respectively leaving the country The matching network models for public transport and road traffic were implemented using VISUM 9.0 of PTV AG, Karlsruhe. The timetable based assignment considers all scheduled train services plus the relevant interurban bus services, in particular in rural areas. The paper has three main parts: the first main part derives and describes for the first time the EVA algorithm in English, including the solution method used. The second part summarizes the results of choice model estimation using the generalised cost elasticities of demand by purpose and traveller type. The third part assesses the quality of the results. These assessments are based on two independently derived matrices, which are available for rail-travel from on board - counts and for commuters from the 2000 national census. In addition, we compare the assign-ment results with the available cross section counts. The conclusions discuss computing times, accuracy and issues for further research.
Rat Monoclonal Antibodies Specific for LST1 Proteins
The LST1 gene is located in the human MHC class III region and encodes transmembrane and soluble isoforms that have been suggested to play a role in the regulation of the immune response and are associated with inflammatory diseases such as rheumatoid arthritis. Here we describe the generation and characterization of the first monoclonal antibodies against LST1. Two hybridoma lines secreting monoclonal antibodies designated 7E2 and 8D12 were established. The 7E2 antibody detects recombinant and endogenous LST1 by Western blot analysis while 8D12 reacts with recombinant and endogenous LST1 in immunoprecipitation and flow cytometry procedures. The newly established antibodies were used to survey LST1 protein expression in human cell lines, which was found to be tightly regulated, allowing the expression of transmembrane isoforms but suppressing soluble isoforms
A Retrospective Analysis of the Fake News Challenge Stance Detection Task
The 2017 Fake News Challenge Stage 1 (FNC-1) shared task addressed a stance
classification task as a crucial first step towards detecting fake news. To
date, there is no in-depth analysis paper to critically discuss FNC-1's
experimental setup, reproduce the results, and draw conclusions for
next-generation stance classification methods. In this paper, we provide such
an in-depth analysis for the three top-performing systems. We first find that
FNC-1's proposed evaluation metric favors the majority class, which can be
easily classified, and thus overestimates the true discriminative power of the
methods. Therefore, we propose a new F1-based metric yielding a changed system
ranking. Next, we compare the features and architectures used, which leads to a
novel feature-rich stacked LSTM model that performs on par with the best
systems, but is superior in predicting minority classes. To understand the
methods' ability to generalize, we derive a new dataset and perform both
in-domain and cross-domain experiments. Our qualitative and quantitative study
helps interpreting the original FNC-1 scores and understand which features help
improving performance and why. Our new dataset and all source code used during
the reproduction study are publicly available for future research
Erweiterung der Verkehrsnachfragemodellierung um Aspekte der Raum- und Infrastrukturplanung
Diese Arbeit stellt grundlegend zwei Modellentwicklungen der Verkehrsangebots- und Verkehrsnachfragemodellierung vor. Die erste Entwicklung bezieht sich auf die simultane Ziel- und Verkehrsmittelwahl in Abhängigkeit von Strukturgrößen und/oder Lagegunst. Es werden neue Randsummenbedingungen beschrieben und vorhandene neu definiert. Der neue Modellansatz erlaubt eine Bestimmung minimaler und maximaler Verkehrsaufkommen und stellt eine Erweiterung der theoretischen Grundlagen als auch der praktischen Anwendbarkeit dar. So können alle derzeit bekannten Randsummenbedingungen durch einen Algorithmus (auch innerhalb einer Quelle-Ziel-Gruppe) berechnet werden. Der zweite Ansatz ist ein Werkzeug, welches in Abhängigkeit des vorhandenen Verkehrsangebotes verkehrsplanerisch wünschenswerte quantitative Flächen- bzw. Gebietsnutzungen abschätzt. Aufbauend auf der Verkehrsangebots- und Verkehrsnachfragemodellierung werden Infrastrukturgrößen durch eine aufzustellende Zielfunktion (z. B. minimale Verkehrsarbeit), unter Beachtung vorhandener Freiheitsgrade der Flächennutzung je Verkehrsbezirk, optimiert. Diese Freiheitsgrade werden als minimale und maximale Strukturgrößengrenzen durch die Raum- und Stadtplanung definiert, womit sie den vielfältigen Einflussgrößen dieser Planungen unterliegen und dadurch städtebaulich verträglich sind. Der Modellansatz bildet die für die Infrastrukturplanung wichtigen Wechselwirkungen des durch den Stadt- und Verkehrsplaner angestrebten Systemoptimums (Infrastrukturgrößenverteilung eines Gebietes) mit dem durch den einzelnen Verkehrsteilnehmer angestrebten Nutzenoptimum (Verkehrsnachfrage) ab.This work basically introduces two model developments of traffic supply and traffic demand modeling. The first development refers to the simultaneous destination and mode choice into dependence of structure sizes and/or accessibility. New constraints are described and available constraints were defined newly. The new model enables the determination of minimal and maximum volumes of traffic (constraints). The new explanatory model is an expansion of the theoretical bases and the practical applicability. So all currently known constraints can be calculated by one algorithm (also within an origin destination group). The second approach is a tool which describes desirable quantitative traffic planningly land uses against the available traffic supply. It uses an algorithm that keeps minimal and maximum structure size limits while it determining e.g. minimal traffic work. Within the algorithm the complete traffic demand will be calculated. The complete model shows the important interactions of the infrastructure planning by the town and transport planer (a striven system optimum) with the traffic demand by the single road user (a striven user equilibrium)
CONSTRAINED TRAFFIC DEMAND MODELS - SIMULTANEOUS DISTRIBUTION AND MODE CHOICE
Unconstrained models are very often found in the broad spectrum of different theories of traffic demand models. In these models there are none or only one-sided restrictions influencing the choice of the individual. However in the traffic demand different deciding dependencies of the traffic volume with regard to the specific conditions of the territory structure potentials exist. Kichhoff and Lohse introduced bi- and tri-linearly constrained models to show these dependencies. In principle, the dependencies are described as hard, elastic and open boundary sum criteria. In this article a model is formulated which gets away from these predefined boundary sum criteria and allows a free determination of minimal and maximal boundary sum criteria. The iterative solution algorithm is shown according to a FURNESS procedure at the same time. With the approach of freely selectable minimal and maximal boundary sum criteria the modeling transport planner gets the possibility to show the traffic event even better. Furthermore all common boundary sum criteria can be calculated with this model. Therewith the often necessary and sensible standard and special cases can also be modeled
Funktion und Expression der transmembranen Isoformen des HLA-Klasse-III-Gens LST1
Die MHC-Klasse-III-Region beherbergt mehrere inflammatorische Gene und enthält das LST1- Gen (Leukocyte Specific Transcript 1). LST1-Transkripte werden stark in Immunzellen, insbesondere in B-Zellen, T-Zellen, Monozyten und Dendritischen Zellen, exprimiert. Die LST1- Transkripte werden durch inflammatorische Stimuli deutlich verstärkt und weiterhin extensiv alternativ gespleißt: Es sind 17 Spleißvarianten bekannt, die 12 unterschiedliche Polypeptide kodieren. Die LST1-Isoformen lassen sich in transmembrane oder lösliche Proteine klassifizieren. Innerhalb dieser Klassen können die LST1-Isoformen in der Sequenz ihrer C-terminalen Aminosäuren teilweise stark variieren. In den bisherigen, funktionellen Studien wurde postuliert, dass LST1-Isoformen sowohl in der Regulation der Immunantwort, wie in der interzellulären Kommunikation eine Rolle spielen. Im Rahmen dieser Arbeit wurde die Funktion und Expression von LST1 auf der Proteinebene untersucht. Aus RNS der U-937-Zelllinie konnten über RT-PCR zehn Spleißvarianten isoliert werden, die unterschiedliche Isoformen kodieren. Die cDNS wurde zur Herstellung von Vektoren für die rekombinante Expression von sechs LST1-Isoformen verwendet. Um auch die endogenen Proteine untersuchen zu können, wurden monoklonale Antikörper gegen bakteriell exprimiertes LST1 hergestellt und charakterisiert. Der LST1-7E2-Antikörper konnte zur Detektion von denaturiertem LST1 in der Western-Analyse eingesetzt werden, während die Klone 2B1 und 8D12 zusätzlich zum Nachweis des nativen Proteins in der Immunpräzipitation, Durchflusszytometrie und Immunzytochemie geeignet waren
A simultaneous two-dimensionally constraint disaggregate trip generation, distribution and mode choice model - Theory and application for a Swiss national model
The Swiss federal government has asked the IVT, ETH Zürich in collaboration with the TU Dresden and Emch+Berger, Zürich to estimate origin-destination matrices by mode and purpose for the year 2000. The zoning system employing about 3'000 zones of very uneven size required a solution algorithm which is fast, but also able to model generation, distribution and mode choice simultaneously, while addressing the different data availability for traffic within, destined for and passing through the country. The EVA algorithm developed by Lohse (1997) was adapted for this purpose. The key proper-ties of the algorithm are its disaggregate description of demand, its use of appropriate logit-type models for the demand distribution, while maintaining the known marginal distributions of the matrices generated. This last point is of particular importance in a large scale planning applica-tion such as the one at hand. The algorithm calculates trip production and attractions by zone using activity pairs. The 17 ac-tivity pairs distinguished are the combinations of two activities, such as home-work or work-leisure. The relevant daily rates are derived for each of the 17 activity pairs from the 2000 Swiss National Travel Survey (Bundesamt für Statistik and Bundesamt für Raumentwicklung, 2001). The zonal attractivity is defined separately for each trip purpose. In addition to the common variables, such as employment or population, detailed descriptions of education places, shop-ping or leisure facilities, overnight accommodations, shopping centres etc. are employed (see Tschopp, Keller and Axhausen, 2003 for the data). The combined destination and mode choice models estimated for the different traveller types and activity pairs are based on the Swiss National Travel survey (RP data), but incorporates re-sults from a prior SP study on mode and route choice (Vrtic and Axhausen, 2004). The different zone sizes and the different levels of data available required the formulation of new additional models for the transit traffic passing through Switzerland and the traffic originat-ing outside, respectively leaving the country The matching network models for public transport and road traffic were implemented using VISUM 9.0 of PTV AG, Karlsruhe. The timetable based assignment considers all scheduled train services plus the relevant interurban bus services, in particular in rural areas. The paper has three main parts: the first main part derives and describes for the first time the EVA algorithm in English, including the solution method used. The second part summarizes the results of choice model estimation using the generalised cost elasticities of demand by purpose and traveller type. The third part assesses the quality of the results. These assessments are based on two independently derived matrices, which are available for rail-travel from on board - counts and for commuters from the 2000 national census. In addition, we compare the assign-ment results with the available cross section counts. The conclusions discuss computing times, accuracy and issues for further research
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