Precise Runtime Analysis for Plateau Functions

To gain a better theoretical understanding of how evolutionary algorithms (EAs) cope with plateaus of constant fitness, we propose the n -dimensional \textsc {Plateau} _k function as natural benchmark and analyze how different variants of the (1 + 1) EA optimize it. The \textsc {Plateau} _k function has a plateau of second-best fitness in a ball of radius k around the optimum. As evolutionary algorithm, we regard the (1 + 1) EA using an arbitrary unbiased mutation operator. Denoting by \alpha the random number of bits flipped in an application of this operator and assuming that \Pr [\alpha = 1] has at least some small sub-constant value, we show the surprising result that for all constant k \ge 2 , the runtime T follows a distribution close to the geometric one with success probability equal to the probability to flip between 1 and k bits divided by the size of the plateau. Consequently, the expected runtime is the inverse of this number, and thus only depends on the probability to flip between 1 and k bits, but not on other characteristics of the mutation operator. Our result also implies that the optimal mutation rate for standard bit mutation here is approximately k/(en) . Our main analysis tool is a combined analysis of the Markov chains on the search point space and on the Hamming level space, an approach that promises to be useful also for other plateau problems.

Organizational resilience in hospitality family businesses during the COVID-19 pandemic: a qualitative approach

Purpose This study targeted hospitality family business owners as essential pillars of the tourism industry. How they perceive aspects of the crisis and what they derive organizational resilience from, including the role of their human resources, are explored. Internal and external factors of resilience are analyzed alongside different levels of resilience action. Design/methodology/approach The World Health Organization announced coronavirus disease 2019 (COVID-19) as a pandemic on March 11, 2020. In Tirol, the hospitality industry has particularly been affected as tourism businesses find themselves in the challenging times of returning to normal business, corresponding to the fourth phase in Faulkner’s (2001) Tourism Disaster Management Framework. The authors used a qualitative exploratory approach, using semi-structured interviews. Findings In taking on a holistic explorative approach, the authors determined several methods used by entrepreneurs in dealing with a pandemic crisis to increase business resilience at a specific stage. Internal and external resilience factors have been detected among three levels of resilience action (personal, regional and governmental). The most surprising result of the semi-structured in-depth interviews was the entrepreneurs’ rather positive outlook. Originality/value Generally, this study creates an in-depth understanding of the tourism businesses in their dealing with a global crisis, using family business owners as an exemplary stakeholder group. The authors bridge a gap in the literature by applying a holistic explorative approach in the early stage of a never seen worldwide crisis and by addressing organizational resilience. Three levels of resilience action give new insight into how the beginning of a pandemic crisis is handled and perceived by hospitality family business entrepreneurs.

Microstructural Stability of the CoCrFe2Ni2 High Entropy Alloys with Additions of Cu and Mo

New High Entropy Alloys based on the CoCrFe2Ni2 system have been developed by adding up to 10 at. % of Cu, Mo, and Cu + Mo in different amounts. These alloys showed a single face-centred cubic (FCC) structure after homogenization at 1200 °C. In order to evaluate their thermal stability, aging heat treatments at 500, 700, and 900 °C for 8 h were applied to study the possible precipitation phenomena. In the alloys where only Cu or Mo was added, we found the precipitation of an FCC Cu-rich phase or the µ phase rich in Mo, respectively, in agreement with some of the results previously shown in the literature. Nevertheless, we have observed that when both elements are present, Cu precipitation does not occur, and the formation of the Mo-rich phase is inhibited (or delayed). This is a surprising result as Cu and Mo have a positive enthalpy of mixing, being immiscible in a binary system, while added together they improve the stability of this system and maintain a single FCC crystal structure from medium to high temperatures

Design of novel specific primers for helicobacter detection with diagnostic utility evaluation of different 16srRNA genus-specific primers: A comparative study

Molecular diagnosis of helicobacters by PCR is simpler, more accurate, and feasible compared to other diagnostic methods. Validity and accuracy are highly dependent on the PCR primer design, diffusion time, and mutation rate of helicobacters. This study aimed to design 16srRNA -specific primers for Helicobacter spp. and H. pylori . Application of comparative statistical analysis of the diagnostic utility of the most available 16srRNA genus-specific primers. The new primers were designed using bioinformatics tools (MAFFT MSA and Gblocks command line). A comparative study was applied on nine genus-specific 16srRNA primers in comparison to the ConsH using Insilco and laboratory evaluation. The results demonstrated that the best specificity and sensitivity of the primers designed for this study compared to other primers. The comparative study revealed that the heminested outer/inner primers were the worst. Although H276,16srRNA(a), HeliS/Heli-nest, and Hcom had acceptable diagnostic utility, false positive and false negative results were obtained. Specificity testing on clinical samples indicated a surprising result; that H. pylori was not the sole enemy that we were looking for, but the NPH should be considered as a real risk prognostic for gastric diseases, consequently, a specific diagnosis and treatment should be developed. This study concluded that our designed primers were the most specific and sensitive in comparison with other primers. in addition, Insilco evaluation is not accurate enough for primer assessment and that the laboratory evaluation is mandatory.

Old Dogma, New Tricks

This chapter studies the relationship between traditional Christian beliefs and the structure of modern science. The significance of key doctrines—such as monotheism, creation, the fall, the atonement—to the scientific revolution is analyzed, with the perhaps surprising result being that Christianity provided fertile ground for what we would recognize as “modern” science to develop. The writings of Francis Bacon, René Descartes, Isaac Newton, Johannes Kepler, and more are considered through a theological lens and their religious beliefs are shown to be foundational for their scientific work. Several living scientists are also found making the same points, and it is concluded that much of what we now call the “scientific method” owes its underlying philosophy to the core beliefs of the medieval (and even early) Church.

ONLY A SMALL FRACTION OF CELLS PRODUCE ASSEMBLED CAPSIDS DURING TRANSFECTION-BASED MANUFACTURING OF ADENO-ASSOCIATED VIRUS VECTORS

Plasmid transfection of mammalian cells is the dominant platform used to produce adeno-associated virus (AAV) vectors for clinical and research applications. Low yields from this platform currently make it difficult to supply these activities with adequate material. In an effort to better understand the current limitations of transfection-based manufacturing, this study examines what proportion of cells in a model transfection produce appreciable amounts of assembled AAV capsid. Using conformation-specific antibody staining and flow cytometry we report the surprising result that despite obtaining high transfection efficiencies and nominal vector yields in our model system, only 5-10% of cells appear to produce measurable levels of assembled AAV capsids. This finding implies that considerable increases in vector titer could be realized through increasing the proportion of productive cells. Furthermore, we suggest that the flow cytometry assay used here to quantify productive cells may be a useful metric for future optimization of transfection-based AAV vector manufacturing platforms.

MIP* = RE

Note from the Research Highlights Co-Chairs: A Research Highlights paper appearing in Communications is usually peer-reviewed prior to publication. The following paper is unusual in that it is still under review. However, the result has generated enormous excitement in the research community, and came strongly nominated by SIGACT, a nomination seconded by external reviewers. The complexity class NP characterizes the collection of computational problems that have efficiently verifiable solutions. With the goal of classifying computational problems that seem to lie beyond NP, starting in the 1980s complexity theorists have considered extensions of the notion of efficient verification that allow for the use of randomness (the class MA), interaction (the class IP), and the possibility to interact with multiple proofs, or provers (the class MIP). The study of these extensions led to the celebrated PCP theorem and its applications to hardness of approximation and the design of cryptographic protocols. In this work, we study a fourth modification to the notion of efficient verification that originates in the study of quantum entanglement. We prove the surprising result that every problem that is recursively enumerable, including the Halting problem, can be efficiently verified by a classical probabilistic polynomial-time verifier interacting with two all-powerful but noncommunicating provers sharing entanglement. The result resolves long-standing open problems in the foundations of quantum mechanics (Tsirelson's problem) and operator algebras (Connes' embedding problem).

Political Economy of Protection

The political economy of protection is a field within economics, but it has significant overlap with its sister discipline, political science. For a political economy of protection, one needs at a minimum two types of economic agents: political decision makers who provide protection, and economic agents who are protected or even actively seek protection. The typical political economy scenario leads to an economic outcome that is not Pareto-optimal: From a general welfare perspective, the political interaction is not desirable. An important task of political economy research is to explain why and how political interaction takes place. For the first part of the question, it appears clear that if protection is actively sought, the protection seeker intends to benefit from his activities. However, if the policymakers were truly interested in Pareto optimality and welfare maximization, they would refuse to protect. Hence a crucial assumption in the political economy literature is that the politicians’ objective function differs from the general welfare function. For the second part of the question, theoretical political economy models consider either the election campaign phase when politicians are eager to win a majority of votes (preelection models) or the phase when the politicians have been elected and may benefit from the spoils associated with holding office (postelection models). Whereas in the election phase, politicians have an incentive to cater to the interests of that part of the electorate that is considered pivotal for the election outcome, in the postelection phase they may be open to, for example, special interest group (SIG) influences from which they derive utility. A first wave of theoretical political economy models originates from the 1980s. Building on these early advances, more elaborate models have been proposed. The most prominent one is the Grossman–Helpman protection for sale (PfS) model. It delivers a postelection general equilibrium framework of trade policy determination. In this common agency model, industry interest groups act as principals and offer the government a menu of contracts of campaign contributions in exchange for trade policy. The PfS model predicts that industries that lobby for protection will obtain trade protection in equilibrium, whereas nonlobbying industries will face import subsidies. Numerous papers have evaluated the PfS model empirically and found that the implied weight on contributions in the governmental welfare function and the implied share of the population represented by lobbies are both very high. Remedies for this surprising result exist, but it has also been argued that the found empirical regularities may be spurious. At the beginning of the 21st century, the majority of political economy literature is still theoretical, but better data availability increasingly offers the opportunity to empirically test theoretical results. A number of challenges remain for the political economy literature, however. In particular, more work is required to better understand policymaker interests. Moreover, an incorporation of political economy aspects into the new trade theory models that allow for intra-industry trade and firm diversity appears to be a promising avenue for future research.

The Known Unknowns: What Citizen Science Projects in Germany Know about Their Volunteers—And What They Don’t Know

The citizen science landscape in Germany offers an enormous range for participation. More than 170 projects currently present themselves on the national citizen science platform. In 2020, we conducted a survey among 140 projects (participation rate 56%), and they provided information on the organisational framework and characteristics (disciplines, initiators, funding, and project goals), as well as on the academic researchers and the volunteering citizen scientists involved. A surprising result was that the level of knowledge about the volunteers is very low overall. Many projects deliberately do not collect personal data (e.g., on socio-demographic variables, knowledge, and behaviour), partly for data-protection reasons and partly because they are unsure about how to collect it due to a lack of instruments and standards. We aim to illustrate the complexity of this issue and discuss various dilemmas arising between theoretical aspirations and the pragmatic and procedural realities in practice. We conclude with suggestions for developing project-specific strategies to increase diversity and inclusion. We argue that the task of conducting accompanying research on participant diversity cannot be borne by individual projects alone and consider the development and implementation of co-creative and qualitative approaches suitable for this purpose.

Are There Limits in Explainability of Prognostic Biomarkers? Scrutinizing Biological Utility of Established Signatures

Prognostic biomarkers can have an important role in the clinical practice because they allow stratification of patients in terms of predicting the outcome of a disorder. Obstacles for developing such markers include lack of robustness when using different data sets and limited concordance among similar signatures. In this paper, we highlight a new problem that relates to the biological meaning of already established prognostic gene expression signatures. Specifically, it is commonly assumed that prognostic markers provide sensible biological information and molecular explanations about the underlying disorder. However, recent studies on prognostic biomarkers investigating 80 established signatures of breast and prostate cancer demonstrated that this is not the case. We will show that this surprising result is related to the distinction between causal models and predictive models and the obfuscating usage of these models in the biomedical literature. Furthermore, we suggest a falsification procedure for studies aiming to establish a prognostic signature to safeguard against false expectations with respect to biological utility.