Post-IPO Employment and Revenue Growth for U.S. IPOs, June 1996-2010

Analyzes employment and revenue growth, survival rate, sector, location, and venture capital involvement of U.S. companies that held initial public offerings on American markets from June 1996 through 2010, with a focus on firms younger than thirty years

Meteorological forecasts and the pricing of weather derivatives

In usual pricing approaches for weather derivatives, forward-looking information such as meteorological weather forecasts is not considered. Thus, important knowledge used by market participants is ignored in theory. By extending a standard model for the daily temperature, this paper allows the incorporation of meteorological forecasts in the framework of weather derivative pricing and is able to estimate the information gain compared to a benchmark model without meteorological forecasts. This approach is applied for temperature futures referring to New York, Minneapolis and Cincinnati with forecast data 13 days in advance. Despite this relatively short forecast horizon, the models using meteorological forecasts outperform the classical approach and more accurately forecast the market prices of the temperature futures traded at the Chicago Mercantile Exchange (CME). Moreover, a concentration on the last two months or on days with actual trading improves the results.Weather forecasting, weather risk, price forecasting, nancial markets, temperature futures, CME

Layer-Wise Relevance Propagation for Explaining Deep Neural Network Decisions in MRI-Based Alzheimer's Disease Classification

Deep neural networks have led to state-of-the-art results in many medical imaging tasks including Alzheimer’s disease (AD) detection based on structural magnetic resonance imaging (MRI) data. However, the network decisions are often perceived as being highly non-transparent, making it difficult to apply these algorithms in clinical routine. In this study, we propose using layer-wise relevance propagation (LRP) to visualize convolutional neural network decisions for AD based on MRI data. Similarly to other visualization methods, LRP produces a heatmap in the input space indicating the importance/relevance of each voxel contributing to the final classification outcome. In contrast to susceptibility maps produced by guided backpropagation (“Which change in voxels would change the outcome most?”), the LRP method is able to directly highlight positive contributions to the network classification in the input space. In particular, we show that (1) the LRP method is very specific for individuals (“Why does this person have AD?”) with high inter-patient variability, (2) there is very little relevance for AD in healthy controls and (3) areas that exhibit a lot of relevance correlate well with what is known from literature. To quantify the latter, we compute size-corrected metrics of the summed relevance per brain area, e.g., relevance density or relevance gain. Although these metrics produce very individual “fingerprints” of relevance patterns for AD patients, a lot of importance is put on areas in the temporal lobe including the hippocampus. After discussing several limitations such as sensitivity toward the underlying model and computation parameters, we conclude that LRP might have a high potential to assist clinicians in explaining neural network decisions for diagnosing AD (and potentially other diseases) based on structural MRI data

The contribution of microembolic signals (MES) detection in cardioembolic stroke

SummaryBackgroundCardioembolic stroke accounts for about one third of all strokes. Microembolic signals (MES) are frequently found in patients with acute stroke. The role of MES in cardioembolic stroke is less well investigated.MethodsMedline based literature review of clinical trials linking MES and stroke with cardiac sources of various risks.ResultsMES are a rare finding in patients with cardioembolic stroke as well as in sources of potential cardiac embolism (e.g. myocardial infarction, atrial fibrillation, left ventricular thrombus). The low number of patients with MES and the low number of MES during the investigation times leads to a limited statistical power of positive and negative findings. MES in patients with artificial heart valves and the DeBakey left ventricular assist device (LVAD) are predominantly gaseous and do not correlate with stroke risk. In patients with the Novacor LVAD, MES strongly correlate with stroke risk.ConclusionCurrently, the role of MES in cardioembolic stroke is only limited due to both, the low prevalence of MES and the number of MES per investigation. Larger studies would be needed to strengthen this role

WHY CHRIST MUST ALSO BE GOD

Does it make sense to celebrate jubilees like "œTwo thousand years of Christianity", "œSeventeen hundred years Edict of Milan" or "œFive hundred years of Reformation in Europe and the World" in times like ours, when Christian traditions are open to doubt and wide-spread suspicion, even in the formerly "œChristian Occident"? No doubt, the critique must be taken seriously, if it proves to be valid. If not, Christians are free or, what is more, obliged to criticize the critics, e.g. as far as one of the principal items of the Christian tradition is concerned, the Christology, interpreted by one of the major Church Fathers, Athanasius of Alexandria (ca. 294-373), who was convinced, that Jesus Christ must be no less than God himself (αá½Ï„ὸς ὠθεός) in order to be our Saviour

Dionysios Ps.-Areiopagites im heutigen Forschungsgespräch

The intention of this paper is to overcome an alarming polarization within the actual academic debate on the writing of the unknown author of the Corpus Areopagiticum. It discusses five exemplary problems: a. unity and diversity in God; b. theurgy in Proklos and Ps.-Dionysios; c. Porphyry, Dionysios and the “anthropological Model” for the solution of the Christological problem; d. ambivalences within the Dionysian corpus; e. the intention of the author. In the introduction the paper also touches – very briefly, it is true – upon the question, if Peter the Iberian could have been the author of that corpus, as – independently from each other – E. Honigmann and S. Nutsubidze once proposed

Lossless State Detection of Single Neutral Atoms

We introduce lossless state detection of trapped neutral atoms based on cavity-enhanced fluorescence. In an experiment with a single 87-Rb atom, a hyperfine-state-detection fidelity of 99.4% is achieved in 85 microseconds. The quantum bit is interrogated many hundreds of times without loss of the atom while a result is obtained in every readout attempt. The fidelity proves robust against atomic frequency shifts induced by the trapping potential. Our scheme does not require strong coupling between the atom and cavity and can be generalized to other systems with an optically accessible quantum bit.Comment: 4 pages, 4 figure

Perceptual Grouping through Competition in Coupled Oscillator Networks

Meier M, Haschke R, Ritter H. Perceptual Grouping through Competition in Coupled Oscillator Networks. In: European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN). Bruges (Belgium): d-side; 2013.In this paper we present a novel approach to model perceptual grouping based on phase and frequency synchronization in a network of coupled Kuramoto oscillators. Transferring the grouping concept from the Competitive Layer Model (CLM) to a network of Kuramoto oscillators, we preserve the excellent grouping capabilities of the CLM, while dramatically improving the convergence rate, robustness to noise, and computational performance, which is verified in a series of artificial grouping experiments

A comprehensive flow-cytometric analysis of graft infiltrating lymphocytes, draining lymph nodes and serum during the rejection phase in a fully allogeneic rat cornea transplant model

Purpose: To establish a cornea transplant model in a pigmented rat strain and to define the immunologic reaction toward corneal allografts, by studying the cellular and humoral immune response after keratoplasty. Methods:Full thickness penetrating keratoplasty was performed on Brown Norway (RT1n) recipients using fully major histocompatibility complex (MHC)-mismatched Piebald-Viral-Glaxo (PVG; RT1c) donors. Using multicolor flow cytometry (FACS) we quantified and compared the cellular composition of draining versus non-draining lymph nodes (LN). Furthermore, we developed an isolation method to release viable graft infiltrating lymphocytes (GIL) and subjected them to phenotypic analysis and screened serum from transplanted animals for allo-antibodies. Results:Assessing ipsi-lateral submandibular LN we find ample evidence for post surgical inflammation such as elevated absolute numbers of cluster of differentiation (CD)4+, CD8+, B-cells, and differential expression of CD134. However, we could not unequivocally identify an allo-antigen-specific immune response. FACS analysis of lymphocytes isolated from collagenase digested rejected corneas revealed the following six distinct subpopulations: MHC-2+ cells, CD4+ T-cells, CD8+ T-cells, CD161dull large granular lymphocytes, CD3+ CD8+ CD161dull natural killer (NK)-T-cells and CD161high CD3- NK cells. At post-operation day (POD)-07 only CD161dull MHC-2neg large granular lymphocytes (LGLs) were detected in syngeneic and allo-grafts. In concordance with an increase in B-cell numbers we often detected copious amounts of allo-antibodies in serum of rejecting animals, in particular immunoglobulin (Ig) M (IgM), immunoglobulin (Ig) G1 (IgG1), and IgG2a. Conclusions:Our results demonstrate that despite its immune privileged status and low-responder characteristics of the strain combination, allogeneic corneal grafts mount a full fledged T helper1 (Th1) and Th2 response. The presence of NK-T-cells and NK-cells in rejecting corneas shows the synergy between innate and adaptive immunity during allograft destruction

Generation of single photons from an atom-cavity system

A single rubidium atom trapped within a high-finesse optical cavity is an efficient source of single photons. We theoretically and experimentally study single-photon generation using a vacuum stimulated Raman adiabatic passage. We experimentally achieve photon generation efficiencies of up to 34% and 56% on the D1 and D2 line, respectively. Output coupling with 89% results in record-high efficiencies for single photons in one spatiotemporally well-defined propagating mode. We demonstrate that the observed generation efficiencies are constant in a wide range of applied pump laser powers and virtual level detunings. This allows for independent control over the frequency and wave packet envelope of the photons without loss in efficiency. In combination with the long trapping time of the atom in the cavity, our system constitutes a significant advancement toward an on-demand, highly efficient single-photon source for quantum information processing tasks.Comment: 7 pages, 5 figure