On the Hardness of Bribery Variants in Voting with CP-Nets

We continue previous work by Mattei et al. (Mattei, N., Pini, M., Rossi, F., Venable, K.: Bribery in voting with CP-nets. Ann. of Math. and Artif. Intell. pp. 1--26 (2013)) in which they study the computational complexity of bribery schemes when voters have conditional preferences that are modeled by CP-nets. For most of the cases they considered, they could show that the bribery problem is solvable in polynomial time. Some cases remained open---we solve two of them and extend the previous results to the case that voters are weighted. Moreover, we consider negative (weighted) bribery in CP-nets, when the briber is not allowed to pay voters to vote for his preferred candidate.Comment: improved readability; identified Cheapest Subsets to be the enumeration variant of K.th Largest Subset, so we renamed it to K-Smallest Subsets and point to the literatur; some more typos fixe

Exploiting bounded signal flow for graph orientation based on cause-effect pairs

Background: We consider the following problem: Given an undirected network and a set of sender–receiver pairs, direct all edges such that the maximum number of “signal flows ” defined by the pairs can be routed respecting edge directions. This problem has applications in understanding protein interaction based cell regulation mechanisms. Since this problem is NP-hard, research so far concentrated on polynomial-time approximation algorithms and tractable special cases. Results: We take the viewpoint of parameterized algorithmics and examine several parameters related to the maximum signal flow over vertices or edges. We provide several fixed-parameter tractability results, and in one case a sharp complexity dichotomy between a linear-time solvable case and a slightly more general NP-hard case. We examine the value of these parameters for several real-world network instances. Conclusions: Several biologically relevant special cases of the NP-hard problem can be solved to optimality. In this way, parameterized analysis yields both deeper insight into the computational complexity and practical solving strategies. Background Current technologies [1] like two-hybrid screening ca

Neural Underpinnings of the Perception of Emotional States Derived From Biological Human Motion: A Review of Neuroimaging Research

Research on the perception of biological human motion shows that people are able to infer emotional states by observing body movements. This article reviews the methodology applied in fMRI research on the neural representation of such emotion perception. Specifically, we ask how different stimulus qualities of bodily expressions, individual emotional valence, and task instructions may affect the neural representation of an emotional scene. The review demonstrates the involvement of a variety of brain areas, thereby indicating how well the human brain is adjusted to navigate in multiple social situations. All stimulus categories (i.e., full-light body displays, point-light displays, and avatars) can induce an emotional percept and are associated with increased activation in an extensive neural network. This network seems to be organized around areas belonging to the so-called action observation network (PMC, IFG, and IPL) and the mentalizing network (TPJ, TP, dmPFC, and lOFC) as well as areas processing body form and motion (e.g., EBA, FBA, and pSTS). Furthermore, emotion-processing brain sites such as the amygdala and the hypothalamus seem to play an important role during the observation of emotional body expressions. Whereas most brain regions clearly display an increased response to emotional body movements in general, some structures respond selectively to negative valence. Moreover, neural activation seems to depend on task characteristics, indicating that certain structures are activated even when attention is shifted away from emotional body movements

Production of Toxic Volatile Trimethylbismuth by the Intestinal Microbiota of Mice

The biotransformation of metals and metalloids into their volatile methylated derivatives by microbes growing under anaerobic conditions (e.g., the mammalian intestinal microbiota) plays an important role in spreading these compounds in the environment. In this paper, we could show that the presence of an intact intestinal microbiota of mice provides the conditio sine qua non for the production of these mostly toxic derivatives. To document the indispensible role of the intestinal microbiota in methylating metals and metalloids to volatile derivatives under in vivo conditions, we compared the methylation capability of conventionally raised (CONV) and germ-free (GF) B6-mice fed with chow containing colloidal bismuth subcitrate (CBS) as the starting material for the formation of volatile methylated metal(loid)s. Permethylated volatile trimethylbismuth ((CH3)3Bi) was only detected in the blood of the conventionally raised mice. Concomitantly, a higher bismuth concentration was found in organs such as liver, lung, testicles, and brain of the CONV mice as compared to those of GF mice (P > 0.01), strongly suggesting a correlation between the intestinal biomethylation of bismuth and its accumulation in mammalian tissues

Abdominal obesity‐related disturbance of insulin sensitivity is associated with cd8+ emra cells in the elderly

Aging and overweight increase the risk of developing type 2 diabetes mellitus. In this cross‐sectional study, we aimed to investigate the potential mediating role of T‐EMRA cells and inflammatory markers in the development of a decreased insulin sensitivity. A total of 134 healthy older volunteers were recruited (age 59.2 (SD 5.6) years). T cell subpopulations were analyzed by flow cytometry. Furthermore, body composition, HOMA‐IR, plasma tryptophan (Trp) metabolites, as well as cytokines and adipokines were determined. Using subgroup and covariance analyses, the influence of BMI on the parameters was evaluated. Moreover, correlation, multiple regression, and mediation analyses were performed. In the subgroup of participants with obesity, an increased proportion of CD8+EMRA cells and elevated concentrations of plasma kynurenine (KYN) were found compared to the lower‐weight subgroups. Linear regression analysis revealed that an elevated HOMA‐IR could be predicted by a higher proportion of CD8+EMRA cells and KYN levels. A mediation analysis showed a robust indirect effect of the Waist‐to‐hip ratio on HOMA‐IR mediated by CD8+EMRA cells. Thus, the deleterious effects of abdominal obesity on glucose metabolism might be mediated by CD8+EMRA cells in the elderly. Longitudinal studies should validate this assumption and analyze the suitability of CD8+EMRA cells as early predictors of incipient prediabetes. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Femtosecond fluorescence up-conversion spectroscopy of a rotation-restricted azobenzene after excitation to the S1 state

Femtosecond time-resolved fluorescence up-conversion spectroscopy has been used in a study of the photo- induced isomerization reactions of a rotation-restricted trans-azobenzene (trans-AB) derivative capped by a crown ether (1), a chemically similar open derivative (2), and unsubstituted trans-AB (3) after excitation to the S 1 (np*) state at l ¼ 475 nm in dioxane solution. The observed biexponential temporal fluorescence profiles for 1 and 2 were almost indistinguishable within experimental error. The fitted fast fluorescence decay times (2s) for the two compounds were t 1 (1) ¼ (0.79 0.20) and t 1 (2) ¼ (1.05 0.20) ps, compared to t 1 (3) ¼ (0.37 0.06) ps. The second decay components could be described with t 2 (1) ¼ (20.3 9.5) resp. t 2 (2) ¼ (19.0 6.0) ps, vs. t 2 (3) ¼ (3.26 0.85) ps. The very similar lifetimes strongly suggest that trans–cis isomerization of 1 and 2 after S 1 excitation is governed by the same mechanism. Since 1 cannot isomerize by a simple large-amplitude rotation of one of the phenyl rings about the central NN bond, the isomerization dynamics of both ABs should be better described as ‘‘inversion’’ at the N atom(s) rather than large-amplitude ‘‘rotation’’

A Design Space Exploration of Creative Concepts for Care Robots: Questioning the Differentiation of Social and Physical Assistance

In an interdisciplinary project, creative concepts for care robotics were developed. To explore the design space that these open up, we discussed them along the common differentiation of physical (effective) and social-emotional assistance. Trying to rate concepts on these dimensions frequently raised questions regarding the relation between the social-emotional and the physical, and highlighted gaps and a lack of conceptual clarity. We here present our design concepts, report on our discussion, and summarize our insights; in particular we suggest that the social and the physical dimension of care technologies should always be thought of and designed as interrelated

Datenunabhängigkeit in relationalen Datenbankmanagementsystemen : Untersuchung der Konzepte und Maßnahmen zur Verbesserung am Beispiel von SQL/OS

Physische und logische Datenunabhängigkeit sind Forderungen anein Datenbanksystem, welche auf dem 3-Ebenen-Modell basieren. Die drei Ebenen desModells finden sich in relationalen Datenbanksystemen wieder, die konzeptuelle Ebeneals Tabellen, die externe Ebene als Views, Zugriffsberechtigungen und Synonymen, dieinterne Ebene in Speicherung und Zugriffspfaden. Die Transformationen zwischen denEbenen sind schließlich als Katalogeintragungen implementiert. Im Rahmen der Unabhängigkeitsforderungensoll die konzeptuelle Ebene unbeeinflußt von Änderungen beiSpeicherung und Zugriffspfaden bleiben, die externe Ebene soll, soweit möglich, unabhängigvon Modifikationen der konzeptuellen Ebene sein. Bei relationalen Datenbanksystemensind diese Datenunabhängigkeiten nicht verwirklicht. Es wird untersucht, beiwelchen Änderungen Datenabhängigkeiten existieren und welcher Aufwand von denBenutzern eines Datenbankmanagementsystems erfolgen muß, um Datenunabhängigkeitzu erreichen. Die Algorithmen eines Prolog-Programmsystems werden dargestellt,welches für SQL/DS beinahe physische Datenunabhängigkeit erzielt und die logischeDatenunabhängigkeit weitgehend verbessert

Being Caught Between a Rock and a Hard Place in an Election-Voter Deterrence by Deletion of Candidates

Abstract We introduce a new problem modeling voter deterrence by deletion of candidates in elections: In an election, the removal of certain candidates might deter some of the voters from casting their votes, and the lower turnout then could cause a preferred candidate to win the election. This is a special case of the variant in the family of 'control' problems in which an external agent is allowed to delete candidates and votes in order to make his preferred candidate win, and a generalization of the variant where candidates are deleted, but no votes. We initiate a study of the computational complexity of this problem for several voting systems and obtain N P-completeness and W[2]-hardness with respect to the parameter number of deleted candidates for most of them