Using Simon's Algorithm to Attack Symmetric-Key Cryptographic Primitives

We present new connections between quantum information and the field of classical cryptography. In particular, we provide examples where Simon's algorithm can be used to show insecurity of commonly used cryptographic symmetric-key primitives. Specifically, these examples consist of a quantum distinguisher for the 3-round Feistel network and a forgery attack on CBC-MAC which forges a tag for a chosen-prefix message querying only other messages (of the same length). We assume that an adversary has quantum-oracle access to the respective classical primitives. Similar results have been achieved recently in independent work by Kaplan et al. Our findings shed new light on the post-quantum security of cryptographic schemes and underline that classical security proofs of cryptographic constructions need to be revisited in light of quantum attackers.Comment: 14 pages, 2 figures. v3: final polished version, more formal definitions adde

Glucocorticoid-Induced Impairment of Macrophage Antimicrobial Activity: Mechanisms and Dependence on the State of Activation

Experimental observations indicate that tissue macrophages deployed in great numbers at critical anatomic sites such as the liver, spleen, and lung are major targets for glucocorticoids compromising natural resistanceof the host. Therapeutic concentrations ofglucocorticoids appear to prevent destruction of microorganisms ingested by macrophages without interfering with phagocytosis, phagolysosomal fusion, and/or secretion of reactive oxygen intermediates. These findings indicate that at the cellular level the glucocorticoid target should be sought for in the nonoxidative armature of the phagocyte and that nonoxidative killing systems of resident tissue macrophages play an important role in natural resistance to opportunistic pathogens. Glucocorticoids do not prevent lymphokine-induced activation of oxidative killing systems. Thus, lymphokines such as interferon-γ can restore the microbicidal activity of macrophages functionally impaired by glucocorticoids. Counterbalance of the suppressive effect of glucocorticoids by lymphokines might only be possible, however, for pathogens susceptible to oxidative killing and not for microorganisms that are more resistant to reactive oxygen intermediates such as Aspergillus spores and Nocardia, opportunists that appear to be particularly associated with hypercortisolis

Copayments in the German Health System – Do They Work?

This paper examines the effect of copayments on doctor visits using the German health care reform of 2004 as a natural experiment. In January 2004, copayments of 10 euros for the first doctor visit in each quarter have been introduced for all adults in the statutory health insurance. Individuals covered by private health insurance as well as youths have been exempted from these copayments. We use them as control groups in a difference-in-differences approach to identify the causal impact of these copayments on doctor visits. In contrast to expectations and public opinion our results indicate that there are no statistically significant effects of the copayments on the decision of visiting a doctor.Copayment, doctor visits, difference-in-differences, fixed-effect logit

Angiotensinergic innervation of rat and human mesenteric resistant blood vessels

In contrast to the current believe that angiotensin II (Ang II) only interacts with the sympathetic nervous system (SNS) as a circulating hormone, we document here the existence of an endogenous renin-angiotensin system (RAS) in the sympathetic coeliac ganglion and the angiotensinergic innervation with mesenteric resistant blood vessels. Our findings indicate that Ang II is synthesized inside the neurons of sympathetic coeliac ganglion and may act as an endogenous neurotransmitter locally on the mesenteric resistant blood vessels

Fiscal Effects of Minimum Wages: An Analysis for Germany

Against the background of the current discussion on the introduction of statutory minimum wages in Germany, this paper analyzes the potential employment and fiscal effects of such a policy. Based on estimated labor demand elasticities obtained from a structural labor demand model, the empirical results imply that the introduction of minimum wages in Germany will be associated with significant employment losses that are concentrated among marginal and low- and semi-skilled full-time workers. Even though minimum wages will lead to increased public revenues from income taxes and social security benefits, they will result in a significant fiscal burden, due to increased expenditures for unemployment benefits and decreased revenues from corporate taxes.minimum wages, employment, public budget, fiscal effects

Fiscal Effects of Minimum Wages – An Analysis for Germany

Against the background of the current discussion on the introduction of statutory minimum wages in Germany, this paper analyzes the potential employment and fiscal effects of such a policy. Based on estimated labor demand elasticities obtained from a structural labor demand model, the empirical results imply that the introduction of minimum wages in Germany will be associated with significant employment losses that are concentrated among marginal and low- and semi-skilled full-time workers. Even though minimum wages will lead to increased public revenues from income taxes and social security benefits, they will result in a significant fiscal burden, due to increased expenditures for unemployment benefits and decreased revenues from corporate taxes.Minimum wages, employment, public budget, fiscal effects

In-medium kaon and antikaon properties in the quark-meson coupling model

The properties of the kaon, $K$, and antikaon, \kbar, in nuclear medium are studied in the quark-meson coupling (QMC) model. Employing a constituent quark-antiquark (MIT bag model) picture, their excitation energies in a nuclear medium at zero momentum are calculated within mean field approximation. The scalar, and the vector mesons are assumed to couple directly to the nonstrange quarks and antiquarks in the $K$ and \kbar mesons. It is demonstrated that the $\rho$ meson induces different mean field potentials for each member of the isodoublets, $K$ and \kbar, when they are embedded in asymmetric nuclear matter. Furthermore, it is also shown that this $\rho$ meson potential is repulsive for the $K^-$ meson in matter with a neutron excess, and renders $K^-$ condensation less likely to occur.Comment: Latex, 11 pages, 4 Postscript figures, a few typos which can be important for an interpretation (but not reflected in the results) are corrected, as published in (E) Phys. Lett. B 436 (1998) 45

Robust and distributed top-n frequent-pattern mining with SAP BW accelerator

Mining for association rules and frequent patterns is a central activity in data mining. However, most existing algorithms are only moderately suitable for real-world scenarios. Most strategies use parameters like minimum support, for which it can be very difficult to define a suitable value for unknown datasets. Since most untrained users are unable or unwilling to set such technical parameters, we address the problem of replacing the minimum-support parameter with top-n strategies. In our paper, we start by extending a top-n implementation of the ECLAT algorithm to improve its performance by using heuristic search strategy optimizations. Also, real-world datasets are often distributed and modern database architectures are switching from expensive SMPs to cheaper shared-nothing blade servers. Thus, most mining queries require distribution handling. Since partitioning can be forced by user-defined semantics, it is often forbidden to transform the data. Therefore, we developed an adaptive top-n frequent-pattern mining algorithm that simplifies the mining process on real distributions by relaxing some requirements on the results. We first combine the PARTITION and the TPUT algorithms to handle distributed top-n frequent-pattern mining. Then, we extend this new algorithm for distributions with real-world data characteristics. For frequent-pattern mining algorithms, equal distributions are important conditions, and tiny partitions can cause performance bottlenecks. Hence, we implemented an approach called MAST that defines a minimum absolute-support threshold. MAST prunes patterns with low chances of reaching the global top-n result set and high computing costs. In total, our approach simplifies the process of frequent-pattern mining for real customer scenarios and data sets. This may make frequent-pattern mining accessible for very new user groups. Finally, we present results of our algorithms when run on the SAP NetWeaver BW Acceleratorwith standard and real business datasets

A multi-species functional embedding integrating sequence and network structure

A key challenge to transferring knowledge between species is that different species have fundamentally different genetic architectures. Initial computational approaches to transfer knowledge across species have relied on measures of heredity such as genetic homology, but these approaches suffer from limitations. First, only a small subset of genes have homologs, limiting the amount of knowledge that can be transferred, and second, genes change or repurpose functions, complicating the transfer of knowledge. Many approaches address this problem by expanding the notion of homology by leveraging high-throughput genomic and proteomic measurements, such as through network alignment. In this work, we take a new approach to transferring knowledge across species by expanding the notion of homology through explicit measures of functional similarity between proteins in different species. Specifically, our kernel-based method, HANDL (Homology Assessment across Networks using Diffusion and Landmarks), integrates sequence and network structure to create a functional embedding in which proteins from different species are embedded in the same vector space. We show that inner products in this space and the vectors themselves capture functional similarity across species, and are useful for a variety of functional tasks. We perform the first whole-genome method for predicting phenologs, generating many that were previously identified, but also predicting new phenologs supported from the biological literature. We also demonstrate the HANDL embedding captures pairwise gene function, in that gene pairs with synthetic lethal interactions are significantly separated in HANDL space, and the direction of separation is conserved across species. Software for the HANDL algorithm is available at http://bit.ly/lrgr-handl.Published versio

Assimilation of Mobile Marketing in Organisations

This paper explores the assimilation of mobile marketing (MM) in companies. By combining the technology-organization-environment framework and domestication theory, first a structural equation model is build and empirically tested with an online survey. The results show that mobile culture has a significant impact on MM goal achievement. A subsequent cluster analysis shows that there are three segments of companies applying MM: sophisticated, mediocre and unready MM adopters