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Niche parties in Latin America

Theresa Kernecker, Markus Wagner
2018 Figshare  
Niche parties, which have been defined as focusing on a narrow range of issues their competitors neglect, are a phenomenon that has so far been described and analysed primarily in Western Europe. In this paper, we extend existing work by examining the presence and nature of niche parties in Latin America. Using the expert survey data collected by [Wiesehomeier, N., and K. Benoit. 2009. "President, Parties, and Policy Competition." The Journal of Politics 71: 1435–1447], we show that there are
more » ... che parties in most Latin American party systems. Two kinds of niche party, traditionalist and postmaterialist, predominate. We also show that niche parties, despite being defined based on issue-based characteristics, are in fact less programmatic in their linkage strategies than mainstream competitors. Instead, niche parties are slightly more likely to draw on charismatic strategies and tend to establish strong organizational links to ethnic and religious organizations. Niche parties in Latin America are primarily vehicles for the mobilization of group interests. These findings have implications for our understanding of political representation in new democracies and niche party strategies more generally.
doi:10.6084/m9.figshare.6530636 fatcat:4y5rnbna35gh5mrdopv4xmei74

Is perturbation an effective restart strategy? [article]

Aldeida Aleti, Mark Wallace, Markus Wagner
2019 arXiv   pre-print
Premature convergence can be detrimental to the performance of search methods, which is why many search algorithms include restart strategies to deal with it. While it is common to perturb the incumbent solution with diversification steps of various sizes with the hope that the search method will find a new basin of attraction leading to a better local optimum, it is usually not clear how big the perturbation step should be. We introduce a new property of fitness landscapes termed "Neighbours
more » ... th Similar Fitness" and we demonstrate that the effectiveness of a restart strategy depends on this property.
arXiv:1912.02535v1 fatcat:3fvacumwovhntmqqtpooq6icze

Likelihood-free Simulation-based Optimal Design [article]

Markus Hainy, Werner G. Müller, Helga Wagner
2013 arXiv   pre-print
Simulation-based optimal design techniques are a convenient tool for solving a particular class of optimal design problems. The goal is to find the optimal configuration of factor settings with respect to an expected utility criterion. This criterion depends on the specified probability model for the data and on the assumed prior distribution for the model parameters. We develop new simulation-based optimal design methods which incorporate likelihood-free approaches and utilize them in novel
more » ... lications. Most simulation-based design strategies solve the intractable expected utility integral at a specific design point by using Monte Carlo simulations from the probability model. Optimizing the criterion over the design points is carried out in a separate step. M\"uller (1999) introduces an MCMC algorithm which simultaneously addresses the simulation as well as the optimization problem. In principle, the optimal design can be found by detecting the utility mode of the sampled design points. Several improvements have been suggested to facilitate this task for multidimensional design problems (see e.g. Amzal et al. 2006). We aim to extend this simulation-based design methodology to design problems where the likelihood of the probability model is of an unknown analytical form but it is possible to simulate from the probability model. We further assume that prior observations are available. In such a setting it is seems natural to employ approximate Bayesian computation (ABC) techniques in order to be able to simulate from the conditional probability model. We provide a thorough review of adjacent literature and we investigate the benefits and the limitations of our design methodology for a particular paradigmatic example.
arXiv:1305.4273v1 fatcat:ktgenvbscrgjnmnjhwsparx5zi

Discrepancy-based Evolutionary Diversity Optimization [article]

Aneta Neumann, Wanru Gao, Carola Doerr, Frank Neumann, Markus Wagner
2018 arXiv   pre-print
Diversity plays a crucial role in evolutionary computation. While diversity has been mainly used to prevent the population of an evolutionary algorithm from premature convergence, the use of evolutionary algorithms to obtain a diverse set of solutions has gained increasing attention in recent years. Diversity optimization in terms of features on the underlying problem allows to obtain a better understanding of possible solutions to the problem at hand and can be used for algorithm selection
more » ... dealing with combinatorial optimization problems such as the Traveling Salesperson Problem. We explore the use of the star-discrepancy measure to guide the diversity optimization process of an evolutionary algorithm. In our experimental investigations, we consider our discrepancy-based diversity optimization approaches for evolving diverse sets of images as well as instances of the Traveling Salesperson problem where a local search is not able to find near optimal solutions. Our experimental investigations comparing three diversity optimization approaches show that a discrepancy-based diversity optimization approach using a tie-breaking rule based on weighted differences to surrounding feature points provides the best results in terms of the star discrepancy measure.
arXiv:1802.05448v1 fatcat:nj3byono6fe4jjroeg27lfjb6e

Towards Rigorous Validation of Energy Optimisation Experiments [article]

Mahmoud A. Bokhari, Brad Alexander, Markus Wagner
2020 arXiv   pre-print
The optimisation of software energy consumption is of growing importance across all scales of modern computing, i.e., from embedded systems to data-centres. Practitioners in the field of Search-Based Software Engineering and Genetic Improvement of Software acknowledge that optimising software energy consumption is difficult due to noisy and expensive fitness evaluations. However, it is apparent from results to date that more progress needs to be made in rigorously validating optimisation
more » ... . This problem is pressing because modern computing platforms have highly complex and variable behaviour with respect to energy consumption. To compare solutions fairly we propose in this paper a new validation approach called R3-validation which exercises software variants in a rotated-round-robin order. Using a case study, we present an in-depth analysis of the impacts of changing system states on software energy usage, and we show how R3-validation mitigates these. We compare it with current validation approaches across multiple devices and operating systems, and we show that it aligns better with actual platform behaviour.
arXiv:2004.04500v1 fatcat:tvl45njtyzab7hijd4zmxtzir4

Defining and measuring niche parties

Markus Wagner
2011 Party Politics  
Various scholars have recently argued that niche parties are to be distinguished from mainstream parties, in particular because the two party types differ in their programmes, behaviour and strategies. However, there has so far been no attempt to provide a concise, measureable definition of the niche party concept. This paper argues that niche parties are best defined as parties that compete primarily on a small number of non-economic issues. The occurrence of niche parties is then
more » ... ed and measured using issue salience information provided by expert surveys and manifesto data. After comparing the findings to existing definitions, the main characteristics of the niche parties identified are examined in a final step.
doi:10.1177/1354068810393267 fatcat:uzdzf6rubzadlc4gdvi6ghwzbq

Semantic Stability in Social Tagging Streams [article]

Claudia Wagner, Philipp Singer, Markus Strohmaier, Bernardo A. Huberman
2013 arXiv   pre-print
Claudia Wagner is a recipient of a DOC-fForte fellowship of the Austrian Academy of Science.  ... 
arXiv:1311.1162v1 fatcat:v3gqzwiukvbwrk3uonordy2v6u

Synthesis and Structure Elucidation of the Human tRNA Nucleoside Mannosyl-Queuosine [article]

Thomas Carell, Markus Hillmeier, Mirko Wagner, Timm Ensfelder, Eva Korytiakova, Peter Thumbs, Markus Mueller
2021 bioRxiv   pre-print
Queuosine (Q) is a structurally complex, non-canonical RNA nucleoside. It is present in many eukaryotic and bacterial species, where it is part of the anticodon loop of certain tRNAs. In higher vertebrates, including humans, two further modified queuosine-derivatives exist, galactosyl- (galQ) and mannosyl-queuosine (manQ). The function of these low abundant hypermodified RNA nucleosides remains unknown. While the structure of galQ was elucidated and confirmed by total synthesis, the reported
more » ... ucture of manQ still awaits confirmation. By combining total synthesis and LC-MS-co-injection, together with a metabolic feeding study of labelled hexoses, we show here that the natural compound manQ isolated from mouse liver deviates from the literature-reported structure. The chemical structure of the natural product manQ features a novel α-allyl connectivity. The data reported here shows that the yet unidentified glycosylases that attach galactose and mannose to the Q-base have different constitutional connectivity preferences. Knowing the correct structure of manQ will now pave the way towards further elucidation of its biological function.
doi:10.1101/2021.06.24.449707 fatcat:rt4ga5wdvjhufbpr7jo7rfsdum

Evolutionary Diversity Optimization Using Multi-Objective Indicators [article]

Aneta Neumann, Wanru Gao, Markus Wagner, Frank Neumann
2018 arXiv   pre-print
Evolutionary diversity optimization aims to compute a diverse set of solutions where all solutions meet a given quality criterion. With this paper, we bridge the areas of evolutionary diversity optimization and evolutionary multi-objective optimization. We show how popular indicators frequently used in the area of multi-objective optimization can be used for evolutionary diversity optimization. Our experimental investigations for evolving diverse sets of TSP instances and images according to
more » ... ious features show that two of the most prominent multi-objective indicators, namely the hypervolume indicator and the inverted generational distance, provide excellent results in terms of visualization and various diversity indicators.
arXiv:1811.06804v1 fatcat:zpmca3eb5nfzrhaklf3vvkaoz4

Negative Issue Ownership

Markus Wagner, Thomas M. Meyer
2015 West European Politics  
Moreover, policy proximity can act as a heuristic in assessing issue ownership (Stubager and Slothuus 2013; Wagner and Zeglovits 2014) .  ...  Green 2009; Spoon and Klüver 2014; Vavreck 2009; Wagner and Meyer 2014) , while they may provide easy targets for negative campaigning.  ... 
doi:10.1080/01402382.2015.1039380 fatcat:7ta24wxh3nh6dcwm5b7uakqvz4

Exact Approaches for the Travelling Thief Problem [article]

Junhua Wu, Markus Wagner, Sergey Polyakovskiy, Frank Neumann
2017 arXiv   pre-print
Wagner et al. [22] found in a study involving 21 approximate TTP algorithms that only a small subset of them is actually necessary to form a well-performing algorithm portfolio.  ...  Recently, Wagner [21] investigated the Max-Min Ant System (MMAS) [20] on the TTP, and El Yafrani and Ahiod [6] proposed a memetic algorithm (MA2B) and a simulated annealing algorithm (CS2SA).  ... 
arXiv:1708.00331v1 fatcat:s5tshtcadfgflfi65s27raf4bu

Universal Deep Sequence Models for Protein Classification [article]

Nils Strodthoff, Patrick Wagner, Markus Wenzel, Wojciech Samek
2019 bioRxiv   pre-print
Inferring the properties of protein from its amino acid sequence is one of the key problems in bioinformatics. Most state-of-the-art approaches for protein classification tasks are tailored to specific classification tasks and rely on handcrafted features such as position-specific-scoring matrices from expensive database searches and show an astonishing performance on different tasks. We argue that a similar level of performance can be reached by leveraging the vast amount of unlabeled protein
more » ... equence data available from protein sequence databases using a generic architecture that is not tailored to the specific classification task under consideration. To this end, we put forward UDSMProt, a universal deep sequence model that is pretrained on a language modeling task on the Swiss-Prot database and finetuned on various protein classification tasks. For three different tasks, namely enzyme class prediction, gene ontology prediction and remote homology and fold detection, we demonstrate the feasibility of inferring protein properties and reaching state-of-the-art performance from the sequence alone.
doi:10.1101/704874 fatcat:cy6u6i2dl5c3pauz5z2ic4pehe

Inflammatory Effects of Hypothermia and Inhaled H2S During Resuscitated, Hyperdynamic Murine Septic Shock

Florian Wagner, Katja Wagner, Sandra Weber, Bettina Stahl, Markus W. Knöferl, Markus Huber-Lang, Daniel H. Seitz, Pierre Asfar, Enrico Calzia, Uwe Senftleben, Florian Gebhard, Michael Georgieff (+2 others)
2011 Shock  
doi:10.1097/shk.0b013e3181ffff0e pmid:20938376 fatcat:kafmabuamrfgjpqcrdprfxewdq

Growth factor control of autophagy

Markus Wagner
2005 Nature Cell Biology  
MARKUS WAGNER Late autophagosome (indicated by arrow) fusing with a lysosome. Figure reproduced with permission from Cell, doi: 10.1016/j.cell.2004.11.046 © (2005) with permission from Elsevier.  ... 
doi:10.1038/ncb0305-212 pmid:15738970 fatcat:7vwsf4vcpndnzmzd7xwa7y3xpe

Is Surprisal in Issue Trackers Actionable? [article]

James Caddy, Markus Wagner, Christoph Treude, Earl T. Barr, Miltiadis Allamanis
2022 arXiv   pre-print
Background. From information theory, surprisal is a measurement of how unexpected an event is. Statistical language models provide a probabilistic approximation of natural languages, and because surprisal is constructed with the probability of an event occuring, it is therefore possible to determine the surprisal associated with English sentences. The issues and pull requests of software repository issue trackers give insight into the development process and likely contain the surprising events
more » ... of this process. Objective. Prior works have identified that unusual events in software repositories are of interest to developers, and use simple code metrics-based methods for detecting them. In this study we will propose a new method for unusual event detection in software repositories using surprisal. With the ability to find surprising issues and pull requests, we intend to further analyse them to determine if they actually hold importance in a repository, or if they pose a significant challenge to address. If it is possible to find bad surprises early, or before they cause additional troubles, it is plausible that effort, cost and time will be saved as a result. Method. After extracting the issues and pull requests from 5000 of the most popular software repositories on GitHub, we will train a language model to represent these issues. We will measure their perceived importance in the repository, measure their resolution difficulty using several analogues, measure the surprisal of each, and finally generate inferential statistics to describe any correlations.
arXiv:2204.07363v1 fatcat:xh54cakpojhefcuknnxw3gwp3e
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