Linear-time list recovery of high-rate expander codes

We show that expander codes, when properly instantiated, are high-rate list recoverable codes with linear-time list recovery algorithms. List recoverable codes have been useful recently in constructing efficiently list-decodable codes, as well as explicit constructions of matrices for compressive sensing and group testing. Previous list recoverable codes with linear-time decoding algorithms have all had rate at most 1/2; in contrast, our codes can have rate $1 - \epsilon$ for any $\epsilon > 0$. We can plug our high-rate codes into a construction of Meir (2014) to obtain linear-time list recoverable codes of arbitrary rates, which approach the optimal trade-off between the number of non-trivial lists provided and the rate of the code. While list-recovery is interesting on its own, our primary motivation is applications to list-decoding. A slight strengthening of our result would implies linear-time and optimally list-decodable codes for all rates, and our work is a step in the direction of solving this important problem

Das Lehmbruck-Museum in Duisburg

Am 5. Juni 1964 wurde als einer der ersten Museumsneubauten der Nachkriegszeit das Wilhelm Lehmbruck Museum in Duisburg eröffnet. Erbaut wurde das Haus, das das nahezu vollständige Werk Wilhelm Lehmbrucks präsentiert, nach Plänen von Manfred Lehmbruck (1913-1992), einem Sohn des Bildhauers. Der Untersuchung der Museumsarchitektur wird die neuerarbeitete Biographie des Architekten unter besonderer Berücksichtigung der Ausbildungsjahre vorangestellt. Die Darstellung der Planungs- und Baugeschichte reicht von den ersten Überlegungen zu einem Museumsneubau Anfang des 20. Jahrhunderts über die Realisierung in den 1960er Jahren bis zur Fertigstellung des Erweiterungsbaus im Jahre 1987. Damit verknüpft wird der Aufbau der Lehmbruck-Sammlung und die von Manfred Lehmbruck kuratierte Präsentation der Werke im Lehmbruck-Trakt thematisiert. Mit der Frage nach möglichen Vorbildern und Rezeptionswegen sowie einem Überblick über den Museumsdiskurs der Nachkriegszeit wird das Lehmbruck Museum in einen größeren Zusammenhang gestellt. Durch die Auswertung einer Vielzahl bislang unbekannter Bild- und Textdokumente entsteht ein umfassender Blick auf die Duisburger Museumsarchitektur und den Architekten Manfred Lehmbruck.<br

Population size impacts host-pathogen coevolution

Ongoing host–pathogen interactions are characterized by rapid coevolutionary changes forcing species to continuously adapt to each other. The interacting species are often defined by finite population sizes. In theory, finite population size limits genetic diversity and compromises the efficiency of selection owing to genetic drift, in turn constraining any rapid coevolutionary responses. To date, however, experimental evidence for such constraints is scarce. The aim of our study was to assess to what extent population size influences the dynamics of host–pathogen coevolution. We used Caenorhabditus elegans and its pathogen Bacillus thuringiensis as a model for experimental coevolution in small and large host populations, as well as in host populations which were periodically forced through a bottleneck. By carefully controlling host population size for 23 host generations, we found that host adaptation was constrained in small populations and to a lesser extent in the bottlenecked populations. As a result, coevolution in large and small populations gave rise to different selection dynamics and produced different patterns of host–pathogen genotype-by-genotype interactions. Our results demonstrate a major influence of host population size on the ability of the antagonists to co-adapt to each other, thereby shaping the dynamics of antagonistic coevolution

Validation and Generalizability of Preoperative PROMIS Scores to Predict Postoperative Success in Foot and Ankle Patients

Background: A recent publication reported preoperative Patient-Reported Outcomes Measurement Instrumentation System (PROMIS) scores to be highly predictive in identifying patients who would and would not benefit from foot and ankle surgery. Their applicability to other patient populations is unknown. The aim of this study was to assess the validation and generalizability of previously published preoperative PROMIS physical function (PF) and pain interference (PI) threshold t scores as predictors of postoperative clinically meaningful improvement in foot and ankle patients from a geographically unique patient population. Methods: Prospective PROMIS PF and PI scores of consecutive patient visits to a tertiary foot and ankle clinic were obtained between January 2014 and November 2016. Patients undergoing elective foot and ankle surgery were identified and PROMIS values obtained at initial and follow-up visits (average, 7.9 months). Analysis of variance was used to assess differences in PROMIS scores before and after surgery. The distributive method was used to estimate a minimal clinically important difference (MCID). Receiver operating characteristic curve analysis was used to determine thresholds for achieving and failing to achieve MCID. To assess the validity and generalizability of these threshold values, they were compared with previously published threshold values for accuracy using likelihood ratios and pre- and posttest probabilities, and the percentages of patients identified as achieving and failing to achieve MCID were evaluated using χ2 analysis. Results: There were significant improvements in PF (P \u3c .001) and PI (P \u3c .001) after surgery. The area under the curve for PF (0.77) was significant (P \u3c .01), and the thresholds for achieving MCID and not achieving MCID were similar to those in the prior study. A significant proportion of patients (88.9%) identified as not likely to achieve MCID failed to achieve MCID (P = .03). A significant proportion of patients (84.2%) identified as likely to achieve MCID did achieve MCID (P \u3c .01). The area under the curve for PROMIS PI was not significant. Conclusions: PROMIS PF threshold scores from published data were successful in classifying patients from a different patient and geographic population who would improve with surgery. If functional improvement is the goal, these thresholds could be used to help identify patients who will benefit from surgery and, most important, those who will not, adding value to foot and ankle health care. Level of evidence: Level II, Prospective Comparative Stud

Hypothalamic-pituitary suppression with oral contraceptive pills does not improve outcome in poor responder patients undergoing in vitro fertilization-embryo transfer cycles

Purpose: To evaluate and compare the use of OCP with GnRHa for hypothalamic Pituitary suppression in poor responder IVF patients.Methods: Retrospective analysis of IVF-ET cycles of poor responders. Hypothalamic-pituitary suppression with OCP (Group I, n = 29) or GnRHa (Group II, n = 52), followed by stimulation with gonadotropin, oocyte retrieval, and embryo transfer. Baseline characteristics and cycle outcomes were compared.Results: 73 women underwent 81 cycles from 1/1/1999 to 1/1/2000. Baseline characteristics were similar. 31/81 (38%) cycles were cancelled (Group I, 14/29 (48%) vs. Group II, 17/52 (33%), NS). Cycle outcomes including amount of gonadotropin, number of eggs retrieved, number of embryos transferred, and embryo quality were similar. Patients in Group I required fewer days of stimulation to reach oocyte retrieval. Pregnancy outcomes were similar in the two groups.Conclusion: Our retrospective analysis revealed no improvement in IVF cycle outcomes in poor responders who received OCPs to achieve hypothalamic-pituitary suppression instead of GnRHa

Printing in three dimensions with graphene

Responsive graphene oxide sheets form non‐covalent networks with optimum rheological properties for 3D printing. These networks have shear thinning behavior and sufficiently high elastic shear modulus (G′) to build self‐supporting 3D structures by direct write assembly. Drying and thermal reduction leads to ultra‐light graphene‐only structures with restored conductivity and elastomeric behavior