cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic in situ X-ray diffraction of catalyzed alanates

The discovery that hydrogen can be reversible absorbed and desorbed from NaAlH{sub 4} by the addition of catalysts has created an entirely new prospect for lightweight hydrogen storage. NaAlH{sub 4} releases hydrogen through the following set of decomposition reactions: NaAlH{sub 4} {r_arrow} 1/3({alpha}-Na{sub 3}AlH{sub 6}) + 2/3Al + H{sub 2} {r_arrow} NaH + Al + 3/2H{sub 2}. These decomposition reactions as well as the reverse recombination reactions were directly observed using time-resolved in-situ x-ray powder diffraction. These measurements were performed under conditions similar to those found in PEM fuel cell operations (hydrogen absorption: 50--70 C, 10--15 bar Hz, hydrogen resorption: 80--110 C, 5--100 mbar H{sub 2}). Catalyst doping was found to dramatically improve kinetics under these conditions. In this study, the alanate was doped with a catalyst by dry ball-milling NaAlH{sub 4} with 2 mol.% solid TiCl{sub 3}. X-ray diffraction clearly showed that TiCl{sub 3} reacts with NaAlH{sub 4} to form NaCl during the doping process. Partial desorption of NaAlH{sub 4} was even observed to occur during the catalyst doping process.
Asymmetric incidence of sales taxes: A short-run investigation of gasoline prices

This paper investigates the shifting of sales taxes to consumers through retail prices in the short run. Retail data on gasoline prices are used at the station level within the U.S., including observations from all fifty states and the District of Columbia. A difference-in-differences approach is employed to identify the short-run effects of the changes in state taxes as of January 1st, 2015, when five states have increased their gasoline sales taxes, while five other states have decreased theirs. States experiencing such changes in sales taxes (between December 31st, 2014 and January 1st, 2015) are analyzed as the treatment group of a natural policy experiment, where the control group consists of states with no changes in their sales taxes. The results show that both sales-tax increases and decreases are under-shifted to consumer prices, although the under-shifting of sales-tax decreases is much higher (i.e., the asymmetric incidence of sales taxes). The pass-through measures also differ significantly across states, showing the importance of having a nationwide analysis. The results are robust to the consideration of retailer characteristics, wholesale prices, retail brand effects and hourly price changes within each day.
HISTOPATHOLOGICAL ANALYSIS OF 285 CASES OF CORROSION PRODUCT-ASSOCIATED ADVERSE LOCAL TISSUE REACTION (ALTR) WITH WEAR PARTICLE NANO-ANALYSIS IN THREE CLASSES OF IMPLANTS

Increased failure rates due to metallic wear particle-associated adverse local tissue reactions (ALTR) is a significant clinical problem in resurfacing and total hip arthroplasty. Histological analysis and particle characterization are important elements for understanding the biological mechanisms of the reaction and different histological subtypes may have unique needs for longitudinal clinical follow-up and complication rates after revision arthroplasty. Consecutive patients (N=285 cases) presenting with ALTR from three major hip implant classes, metal-on-metal resurfacing and total hip arthroplasty (THA) and non-metal-on-metal THA with dual modular neck were identified from our prospective Osteolysis Tissue Database and Repository and 53 cases were selected for wear particle nano-analysis. Conventional histology : Tissue samples taken from multiple regions around the hip with extensive sampling performed at macroscopic examination were examined by light microscopy. Particle analysis : Tissue samples selected after frozen section evaluation for cellularity and particle content were examined by scanning electron microscopy (SEM), backscatter scanning electron microscopy (BSEM), BSEM-energy-dispersive X-ray spectroscopy (EDS) element mapping examination, transmission electron microscopy (TEM), TEM-EDS element mapping, and X-ray diffraction spectrometry (XRD) examination. ALTR encompasses three main histological patterns: 1) macrophage predominant, 2) mixed lymphocytic and macrophagic, and 3) predominant sarcoid-like granulomas. Duration of implantation and composition of periprosthetic cellular infiltrates was significantly different among the three implant types examined. Distinct differences in the size, shape, and element composition of the metallic particulate material were detected in each implant class, with correlation of the severity of the adverse reaction with element complexity of the particles. ALTR encompasses a diverse range of histological patterns, which are reflective of both the implant configuration independent of manufacturer and clinical features such as duration of implantation. Distinct differences in the metallic particulate material can contribute to explain the histological features of the ALTR and variability of performance of the implants. ALTR exhibits different histological patterns and is dependent on the characteristics of the wear particulate material of each implant class and host immunological reaction.
Grocery Store Density and Food Waste

We study the impact of grocery-store density on the food waste generated at stores and by households. Food waste is a major contributor to carbon emissions (as big as road transport). Identifying a...
Membrane: operating system support for restartable file systems

We introduce Membrane, a set of changes to the operating system to support restartable file systems. Membrane allows an operating system to tolerate a broad class of file system failures and does so while remaining transparent to running applications; upon failure, the file system restarts, its state is restored, and pending application requests are serviced as if no failure had occurred. Membrane provides transparent recovery through a lightweight logging and checkpoint infrastructure, and includes novel techniques to improve performance and correctness of its fault-anticipation and recovery machinery. We tested Membrane with ext2, ext3, and VFAT. Through experimentation, we show that Membrane induces little performance overhead and can tolerate a wide range of file system crashes. More critically, Membrane does so with little or no change to existing file systems thus improving robustness to crashes without mandating intrusive changes to existing file-system code.
Attitudes About 'Fair Use' and Content Sharing in Social Media Applications

The shift to Social Networking Services (SNSs) and mobile messaging apps such as Facebook, Instagram and Snapchat that rely on User-Generated Content (UGC) has challenged notions of fair use under U.S. copyright law. It remains unclear what understandings are common among these app users regarding legal and ethical norms in reusing artistic, journalistic and other types of content outside of online remixer spaces. Our online survey of N=106 users of N=48 SNS platforms and apps measured attitudes regarding fair use under U.S. copyright law and attribution for work that is shared. Participants reported a high level of agreement with more-restrictive conditions for content publishing and reuse. However, analyses of ratings and responses to open-ended questions reveal tension between issues of intellectual integrity and intellectual property.
Option Introductions and the Skewness of Stock Returns

The decision to introduce options for stocks is made by exchanges with the intention of selecting stocks that will generate the most option trading activity. This study hypothesizes that exchanges will introduce options for stocks with positive skewness. The motivation for our tests is based on the idea that some investors have preferences for skewness and the payoff structure of options is conducive to these types of preferences. Results show that the likelihood of introducing options is increasing in the level of return skewness. We also find that stocks with the most pre-introduction skewness generate the most post-listing option volume. © 2017 Wiley Periodicals, Inc. Jrl Fut Mark
Leaving Residual Varus Alignment After Total Knee Arthroplasty Does Not Improve Patient Outcomes

Abstract Background Recent popularity of kinematic alignment and constitutional varus has caused some surgeons to leave varus limbs in residual varus after total knee arthroplasty (TKA). This study assessed whether if patients left in residual varus have improved outcomes compared with those fully corrected to neutral alignment. Methods A retrospective review of 361 consecutive primary TKAs was performed. Anatomic tibiofemoral alignment was measured and knees were categorized as neutral, varus, or valgus. Modern Knee Society scores and University of California Los Angeles Activity Level scores were collected at minimum 1-year follow-up. Results After exclusions for confounds and loss to follow-up, 262 knees were available for analysis, 67% (176) of which were preoperatively varus. Sixty-six percent of varus knees were corrected to neutral, 25.6% were left in residual varus, and 8.5% were corrected to valgus. Median Knee Society objective scores at latest follow-up were greater in knees corrected to neutral (97), followed by knees corrected to varus (95), and valgus (93; P = .025), but post hoc comparisons between pairs of medians were not significant. There was no difference between groups in any other outcome measure ( P ≥ .245) or the amount of improvement from baseline ( P ≥ .423). Sixty percent of native varus patients corrected to neutral, 64% of those corrected to varus, and 40% of those corrected to valgus reported that their knee felt normal ( P = .193). Conclusion Findings fail to support the notion that leaving varus knees in residual varus will improve outcomes and pain. Caution is advised when leaving limbs in residual varus after TKA.
Multivariable averaging on sparse sets

Nonstandard ergodic averages can be defined for a measure-preserving action of a group on a probability space, as a natural extension of classical (nonstandard) ergodic averages. We extend the one-dimensional theory, obtaining L^1 pointwise ergodic theorems for several kinds of nonstandard sparse group averages, with a special focus on the group Z^d. Namely, we extend results for sparse block averages and sparse random averages to their analogues on virtually nilpotent groups, and extend Christ's result for sparse deterministic sequences to its analogue on Z^d. The second and third results have two nontrivial variants on Z^d: a "native" d-dimensional average and a "product" average from the 1-dimensional averages.
Cleaning up the environment in juvenile myelomonocytic leukemia.

Juvenile myelomonocytic leukemia (JMML) is a commonly fatal myeloid leukemia occurring in very young children bearing germline or somatic mutations in genes within the RAS-ERK signaling pathway including NF1 , CBL, KRAS, NRAS , and PTPN11 (1). Leukemia relapse following allogeneic stem cell transplant is uncharacteristically high at 40–50% for JMML patients, and findings from the recently published manuscript by Dong et al .
Incubator Embedded Cell Culture Imaging System (EmSight) Based on Fourier Ptychographic Microscopy

We introduce an incubator embedded cell culture imaging system, named EmSight, which incorporates six compact Fourier ptychographic microscopes with a standard 6-well plate. We conducted a 21-day live mouse dopaminergic neuron imaging using the system.
Communication and cooperation in repeated games

We study the role of communication in repeated games with private monitoring. We first show that without communication, the set of Nash equilibrium payoffs in such games is a subset of the set of e-coarse correlated equilibrium payoffs (e-CCE) of the underlying one-shot game. The value of e depends on the discount factor and the quality of monitoring. We then identify conditions under which there are equilibria with "cheap talk" that result in nearly efficient payoffs outside the set e-CCE. Thus, in our model, communication is necessary for cooperation.
Statistical coarse-graining as an approach to multiscale problems in magnetism

Multiscale phenomena which include several processes occurring simultaneously at different length scales and exchanging energy with each other, are widespread in magnetism. These phenomena often govern the magnetization reversal dynamics, and their correct modeling is important. In the present paper, we propose an approach to multiscale modeling of magnets, applying the ideas of coarse graining. We have analyzed the choice of the weighing function used in coarse graining, and propose an optimal form for this function. Simple tests provide evidence that this approach may be useful for modeling of realistic magnetic systems.
Can Attackers With Limited Information Exploit Historical Data to Mount Successful False Data Injection Attacks on Power Systems

This paper studies physical consequences of unobservable false data injection (FDI) attacks designed only with information inside a subnetwork of the power system. The goal of this attack is to overload a chosen target line without being detected via measurements. To overcome the limited information, a multiple linear regression model is developed to learn the relationship between the external network and the attack subnetwork from historical data. The worst possible consequences of such FDI attacks are evaluated by solving a bi-level optimization problem wherein the first level models the limited attack resources, while the second level formulates the system response to such attacks via dc optimal power flow (OPF). The attack model with limited information is reflected in the dc OPF formulation that only takes into account the system information for the attack subnetwork. The vulnerability of this attack model is illustrated on the IEEE 24-bus reliability test system and the IEEE 118-bus systems.
Chemical reaction-diffusion networks: convergence of the method of lines

We show that solutions of the chemical reaction-diffusion system associated to $$A+B\rightleftharpoons C$$ in one spatial dimension can be approximated in $$L^2$$ on any finite time interval by solutions of a space discretized ODE system which models the corresponding chemical reaction system replicated in the discretization subdomains where the concentrations are assumed spatially constant. Same-species reactions through the virtual boundaries of adjacent subdomains lead to diffusion in the vanishing limit. We show convergence of our numerical scheme by way of a consistency estimate, with features generalizable to reaction networks other than the one considered here, and to multiple space dimensions. In particular, the connection with the class of complex-balanced systems is briefly discussed here, and will be considered in future work.
Multiplex Genome Editing by Natural Transformation (MuGENT) for Synthetic Biology in Vibrio natriegens

Vibrio natriegens has recently emerged as an alternative to Escherichia coli for molecular biology and biotechnology, but low-efficiency genetic tools hamper its development. Here, we uncover how to induce natural competence in V. natriegens and describe methods for multiplex genome editing by natural transformation (MuGENT). MuGENT promotes integration of multiple genome edits at high-efficiency on unprecedented time scales. Also, this method allows for generating highly complex mutant populations, which can be exploited for metabolic engineering efforts. As a proof-of-concept, we attempted to enhance production of the value added chemical poly-β-hydroxybutyrate (PHB) in V. natriegens by targeting the expression of nine genes involved in PHB biosynthesis via MuGENT. Within 1 week, we isolated edited strains that produced ∼100 times more PHB than the parent isolate and ∼3.3 times more than a rationally designed strain. Thus, the methods described here should extend the utility of this species for diverse ...
Redundancy does not imply fault tolerance: analysis of distributed storage reactions to single errors and corruptions

We analyze how modern distributed storage systems behave in the presence of file-system faults such as data corruption and read and write errors. We characterize eight popular distributed storage systems and uncover numerous bugs related to file-system fault tolerance. We find that modern distributed systems do not consistently use redundancy to recover from file-system faults: a single file-system fault can cause catastrophic outcomes such as data loss, corruption, and unavailability. Our results have implications for the design of next generation fault-tolerant distributed and cloud storage systems.
Torsion of locally convex curves

We show that the torsion of any simple closed curve $\Gamma$ in Euclidean 3-space changes sign at least $4$ times provided that it is star-shaped and locally convex with respect to a point $o$ in the interior of its convex hull. The latter condition means that through each point $p$ of $\Gamma$ there passes a plane $H$, not containing $o$, such that a neighborhood of $p$ in $\Gamma$ lies on the same side of $H$ as does $o$. This generalizes the four vertex theorem of Sedykh for convex space curves. Following Thorbergsson and Umehara, we reduce the proof to the result of Segre on inflections of spherical curves, which is also known as Arnold's tennis ball theorem.
Spin-Tensor-Momentum-Coupled Bose-Einstein Condensates

The recent experimental realization of spin-orbit coupling for ultracold atomic gases provides a powerful platform for exploring many interesting quantum phenomena. In these studies, spin represents the spin vector (spin 1/2 or spin 1) and orbit represents the linear momentum. Here we propose a scheme to realize a new type of spin-tensor-momentum coupling (STMC) in spin-1 ultracold atomic gases. We study the ground state properties of interacting Bose-Einstein condensates with STMC and find interesting new types of stripe superfluid phases and multicritical points for phase transitions. Furthermore, STMC makes it possible to study quantum states with dynamical stripe orders that display density modulation with a long tunable period and high visibility, paving the way for the direct experimental observation of a new dynamical supersolidlike state. Our scheme for generating STMC can be generalized to other systems and may open the door for exploring novel quantum physics and device applications.
Modeling Multi-object Configurations via Medial/Skeletal Linking Structures

We introduce a method for modeling a configuration of objects in 2D or 3D images using a mathematical “skeletal linking structure” which will simultaneously capture the individual shape features of the objects and their positional information relative to one another. The objects may either have smooth boundaries and be disjoint from the others or share common portions of their boundaries with other objects in a piecewise smooth manner. These structures include a special class of “Blum medial linking structures”, which are intrinsically associated to the configuration and build upon the Blum medial axes of the individual objects. We give a classification of the properties of Blum linking structures for generic configurations. The skeletal linking structures add increased flexibility for modeling configurations of objects by relaxing the Blum conditions and they extend in a minimal way the individual “skeletal structures” which have been previously used for modeling individual objects and capturing their geometric properties. This allows for the mathematical methods introduced for single objects to be significantly extended to the entire configuration of objects. These methods not only capture the internal shape structures of the individual objects but also the external structure of the neighboring regions of the objects. In the subsequent second paper (Damon and Gasparovic in Shape and positional geometry of multi-object configurations) we use these structures to identify specific external regions which capture positional information about neighboring objects, and we develop numerical measures for closeness of portions of objects and their significance for the configuration. This allows us to use the same mathematical structures to simultaneously analyze both the shape properties of the individual objects and positional properties of the configuration. This provides a framework for analyzing the statistical properties of collections of similar configurations such as for applications to medical imaging.
Recent evolution of extreme cestode growth suppression by a vertebrate host.

Abstract Parasites can be a major cause of natural selection on hosts, which consequently evolve a variety of strategies to avoid, eliminate, or tolerate infection. When ecologically similar host populations present disparate infection loads, this natural variation can reveal immunological strategies underlying adaptation to infection and population divergence. For instance, the tapeworm Schistocephalus solidus persistently infects 0–80% of threespine stickleback (Gasterosteus aculeatus) in lakes on Vancouver Island. To test whether these heterogeneous infection rates result from evolved differences in immunity, we experimentally exposed laboratory-reared fish from ecologically similar high-infection and no-infection populations to controlled doses of Schistocephalus. We observed heritable between-population differences in several immune traits: Fish from the naturally uninfected population initiated a stronger granulocyte response to Schistocephalus infection, and their granulocytes constitutively generate threefold more reactive oxygen species in cell culture. Despite these immunological differences, Schistocephalus was equally successful at establishing initial infections in both host populations. However, the no-infection fish dramatically suppressed tapeworm growth relative to high-infection fish, and parasite size was intermediate in F1 hybrid hosts. Our results show that stickleback recently evolved heritable variation in their capacity to suppress helminth growth by two orders of magnitude. Data from many natural populations indicate that growth suppression is widespread but not universal and, when present, is associated with reduced infection prevalence. Host suppression of helminth somatic growth may be an important immune strategy that aids in parasite clearance or in mitigating the fitness costs of persistent infection.
Predictive inverse optimal control for linear-quadratic-Gaussian systems

Predictive inverse optimal control is a powerful approach for estimating the control policy of an agent from observed control demonstrations. Its usefulness has been established in a number of large-scale sequential decision settings characterized by complete state observability. However, many real decisions are made in situations where the state is not fully known to the agent making decisions. Though extensions of predictive inverse optimal control to partially observable Markov decision processes have been developed, their applicability has been limited by the complexities of inference in those representations. In this work, we extend predictive inverse optimal control to the linearquadratic-Gaussian control setting. We establish close connections between optimal control laws for this setting and the probabilistic predictions under our approach. We demonstrate the effectiveness and benefit in estimating control policies that are influenced by partial observability on both synthetic and real datasets.
Graph Calculus: Scalable Shortest Path Analytics for Large Social Graphs through Core Net.

We focus on the problem of scalable shortest path analytics for large social graphs in this paper. While shortest path distance problem has been investigated extensively, massive graphs on social networks such as Facebook and Linked In call for reinvestigation of the problem due to the requirements of scalability and suitability for distributed computing. We propose a core-net based approach to address the problem. In our new core-net algorithm, popular nodes are selected based on their node degrees. Since some of these popular nodes may not be connected, we further include bridge nodes, which connect two or more popular nodes and improve their connectivity, but are not popular nodes themselves. Breadth First Search (BFS) technique is then used to compute shortest paths between any pair of nodes on the core net. When the shortest path between two arbitrary vertices, u and v, is queried, we approximate it with triangulation. We present a graph calculus theory in which the estimated distance goes to the real shortest distance when the degree threshold goes to zero. Analysis and simulation results confirm the superiority of our design, which can easily scale to MapReduce.
Control of a Flexible Manufacturing System Using Petri Nets

Abstract This paper pre.sents the design, ge.neration. and implementation of the coordinating discrete event control code using Petri nets for an operaung flexible manufacturing system. The automated production system controlled is a one sixth scale physical model of a shop which both performs machining operations and assembly. The system containing two different machining workstations with robotic loading and unloading, a robotic assembly workstatlon, a matenal movement system, and an automated storage and retrieval system The paper provides. a detailed descrption of the system and the network of computers controlling the components. A Petri net model of. this system is constructed using bottom-up and top-down methods and modeling Issues are discussed. A brief descrption of the reallzatlon of the net for supervisory control is given.
Virilizing Adrenocortical Tumors in Childhood: Eight Cases and a Review of the Literature

Eight cases of adrenocortical tumor are presented with a review of the literature. Although such tumors are rare, they are important causes of inappropriate virilization and Cushing's syndrome in childhood. Clinical virilization with or without hypercortisolism was found in all eight children, who were 5 years old or younger. Excessive linear growth was noted, despite evidence of hypercortisolism. Serum levels of dehydroepiandrosterone, dehydroepiandrosterone sulfate, testosterone, and cortisol were elevated in all cases tested and appear to be useful diagnostic alternatives to the more traditional determinations of urine 17-ketosteroids and 17-hydroxycorticosteroids. Abdominal sonography and computed tomography have proven to be reliable tools for tumor localization. Surgical resection was the definitive therapy in all patients, and perioperative steroid replacement was essential. Histologic diagnosis appeared to have little bearing on prognosis, and the majority of pediatric patients have had clinically benign disease. At a mean follow-up of 3 years, seven of the eight children were alive and had no evidence of tumor recurrence.
Evidence-Based Reform in Education

ABSTRACTEducation policies should support the use of programs and practices with strong evidence of effectiveness. The Every Student Succeeds Act (ESSA) contains evidence standards and incentives to use programs that meet them. This provides a great opportunity for evidence to play a stronger role in decisions about education programs and practices. However, for evidence-based reform to prevail, three conditions must exist: many practical programs with solid evidence; trusted and user-friendly reviews of research; and more education policies that provide incentives for use of proven programs. The article discusses recent progress in each of these areas and notes difficulties in each. It makes a case that if these difficulties can be effectively addressed, evidence-based reform may begin to make a meaningful difference in education outcomes at the national level.
Production of Kidney Tumors in Rats With Low Dose of Dimethylnitrosamine After Partial Hepatectomy

The occurrence of kidney tumors in inbred Wistar rats as a result of dimethylnitrosamine (DMN) administration at different intervals after partial hepatectomy was studied. The schedule for DMN administration was determined on the basis of the levels of liver dimethylnitrosamine demethylase (DMN-d) at different intervals after the operation. DMN-d was 62% of the control values at 24 hours. 72% at 72 hours, and 96% at 92 hours after the operation. At these intervals a single dose of DMN (10 mg/kg body wt) was given to partially hepatectomized animals and to untreated controls. At termination, when the animals were 94 weeks old, no kidney tumors were found in the control animals, whereas 23 of 54 animals (43%) that had been given injections of DMN 24 hours after partial hepatectomy developed kidney tumors. Kidney tumor incidence was 28 or 12%, respectively, when the carcinogen was administered 72 of 92 hours after the operation. The kidney tumor incidence and the activity of liver DMN-d were inversely related.
Growth and characterization of BaZnGa

AbstractWe report the growth, structure and characterization of BaZnGa, identifying it as the sole known ternary compound in the Ba–Zn–Ga system. Single crystals of BaZnGa can be grown out of excess Ba–Zn and adopt a tI36 structure type. There are three unique Ba sites and three M = Zn/Ga sites. Using DFT calculations we can argue that whereas one of these three M sites is probably solely occupied by Ga, the other two M sites, most likely, have mixed Zn/Ga occupancy. Temperature-dependent resistivity and magnetization measurements suggest that BaZnGa is a poor metal with no electronic or magnetic phase transitions between 1.8 and 300 K.
Verifying Relative Safety, Accuracy, and Termination for Program Approximations

Approximate computing is an emerging area for trading off the accuracy of an application for improved performance, lower energy costs, and tolerance to unreliable hardware. However, developers must ensure that the leveraged approximations do not introduce significant, intolerable divergence from the reference implementation, as specified by several established robustness criteria. In this work, we show the application of automated differential verification towards verifying relative safety, accuracy, and termination criteria for a class of program approximations. We use mutual summaries to express relative specifications for approximations, and SMT-based invariant inference to automate the verification of such specifications. We perform a detailed feasibility study showing promise of applying automated verification to the domain of approximate computing in a cost-effective manner.
Monitoring Partially Synchronous Distributed Systems Using SMT Solvers

In this paper, we discuss the feasibility of monitoring partially synchronous distributed systems to detect latent bugs, i.e., errors caused by concurrency and race conditions among concurrent processes. We present a monitoring framework where we model both system constraints and latent bugs as Satisfiability Modulo Theories (SMT) formulas, and we detect the presence of latent bugs using an SMT solver. We demonstrate the feasibility of our framework using both synthetic applications where latent bugs occur at any time with random probability and an application involving exclusive access to a shared resource with a subtle timing bug. We illustrate how the time required for verification is affected by parameters such as communication frequency, latency, and clock skew. Our results show that our framework can be used for real-life applications, and because our framework uses SMT solvers, the range of appropriate applications will increase as these solvers become more efficient over time.
A spatially localized architecture for fast and modular DNA computing

Cells use spatial constraints to control and accelerate the flow of information in enzyme cascades and signalling networks. Synthetic silicon-based circuitry similarly relies on spatial constraints to process information. Here, we show that spatial organization can be a similarly powerful design principle for overcoming limitations of speed and modularity in engineered molecular circuits. We create logic gates and signal transmission lines by spatially arranging reactive DNA hairpins on a DNA origami. Signal propagation is demonstrated across transmission lines of different lengths and orientations and logic gates are modularly combined into circuits that establish the universality of our approach. Because reactions preferentially occur between neighbours, identical DNA hairpins can be reused across circuits. Co-localization of circuit elements decreases computation time from hours to minutes compared to circuits with diffusible components. Detailed computational models enable predictive circuit design. We anticipate our approach will motivate using spatial constraints for future molecular control circuit designs. Fast and scalable molecular logic circuits can be created through the spatial organization of DNA hairpins on DNA origami scaffolds.
Regression Discontinuity in Time: Considerations for Empirical Applications

Recent empirical work in several economic fields, particularly environmental and energy economics, has adapted the regression discontinuity (RD) framework to applications where time is the running ...
CERAMIC COMPONENT FRACTURE: GETTING RARER, BUT WHEN IT HAPPENS‥!

Improvements in ceramic materials, component design, and surgical technique have made ceramic bearing complications increasingly rare. However, when it happens, a fractured ceramic component can cause significant pain and morbidity following total hip arthroplasty (THA). The hard and sharp particulate debris from fractured ceramic components can cause damage to the existing hip prosthesis and jeopardise subsequent revision THA results due to third body wear. Patients with ceramic fractures can present with sudden onset of pain and dysfunction. Often, the patient will report a noisy hip articulation. Radiographs can range from subtle densities surrounding the hip implant to complete disintegration and loss of sphericity of the femoral head or acetabular liner. Ceramic component fractures should be treated expeditiously. Revision options for failed ceramic components depend on existing component fixation, position, and locking mechanism and femoral trunnion integrity. In order to retain the implants, the components must be well-fixed, in good position, and have tapers and locking mechanisms that can accept new modular components. Additionally, an extensile exposure and complete synovectomy are necessary to remove as much of the sharp particulate debris. Finally, a new ceramic ball head with a titanium inner sleeve should be used in revisions for fractured ceramics due to their hardness and scratch resistance. Early results for revision surgery for fractured ceramic components were inconsistent. Allain et al. reported on a series of 105 revisions performed for ceramic head fractures and found that the survivorship at 5 years was only 63%. The authors reported a high reoperation rate and also worse survivorship when the acetabular component was retained, a metal head was used for revisions, age younger than 50 years, and when a complete synovectomy was not performed at the time of revision. More recently, Sharma and colleagues reported on a series of 8 ceramic fractures revised to a metal-on-polyethylene articulation performed with a complete synovectomy. At 10-year follow-up, the authors reported on failures; increased wear; or lesser function compared to 6 matched patients undergoing revision using similar implants for other diagnoses. Others have also reported catastrophic failures when revising fractured ceramic components using metal ball heads. In summary, ceramic bearing complications in THA are rare but catastrophic events. A systematic approach to evaluation and management is necessary to ensure a safe return.
Time Delay Compensation for Nonlinear Processes

A new time delay compensation strategy for nonlinear processes is developed and evaluated. Simulation results for a continuous stirred tank reactor demonstrate that the globally linearizing control (GLC) compensation technique can yield poor performance in the presence of unmeasured disturbances and/or plant/model mismatch. A theoretical analysis of a discrete-time version of the GLC predictor indicates that the poor regulatory performance is attributable to ineffective use of the process state variables, which are assumed to be measured. A new discrete-time prediction strategy is developed which provides improved predictions, yet maintains the desirable characteristics of the GLC approach. A continuous-time version of the predictor is combined with an input-output linearizing controller to yield the new time delay compensation strategy. The proposed scheme is computationally efficient and not restricted to open-loop stable processes. Simulation results for the reactor example demonstrate the superior performance and robustness of the proposed compensation strategy as compared to the GLC approach
Performance and risk taking under threat of elimination

Abstract We revisit the incentive effects of elimination tournaments with a fresh approach to identification, the results of which strongly support that performance improves under the threat of elimination and does so, but only in part, due to increases in risk taking. Where we can separately identify changes in risk-independent performance and risk taking, our estimates suggest that at least 23 percent of the improvement in performance induced by potential elimination is due to productive increases in risk taking. These effects are concentrated among those closest to the margin of elimination and among lower-ability competitors.
Effects of mutating α-tubulin lysine 40 on sensory dendrite development.

ABSTRACT Microtubules are essential for neuronal structure and function. Axonal and dendritic microtubules are enriched in post-translational modifications that impact microtubule dynamics, transport and microtubule-associated proteins. Acetylation of α-tubulin lysine 40 (K40) is a prominent and conserved modification of neuronal microtubules. However, the cellular role of microtubule acetylation remains controversial. To resolve how microtubule acetylation might affect neuronal morphogenesis, we mutated endogenous α-tubulin in vivo using a new Drosophila strain that facilitates the rapid knock-in of designer αTub84B alleles (the predominant α-tubulin-encoding gene in flies). Leveraging our new strain, we found that microtubule acetylation, as well as polyglutamylation and (de)tyrosination, is not essential for survival. However, we found that dendrite branch refinement in sensory neurons relies on α-tubulin K40. Mutagenesis of K40 reveals moderate yet significant changes in dendritic lysosome transport, microtubule polymerization and Futsch protein distribution in dendrites but not in axons. Our studies point to an unappreciated role for α-tubulin K40 and acetylation in dendrite morphogenesis. While our results are consistent with the idea that acetylation tunes microtubule function within neurons, they also suggest there may be an acetylation-independent requirement for α-tubulin K40. This article has an associated First Person interview with the first author of the paper.
Gender Differences in Risk Factors for Adolescent Binge Drinking and Implications for Intervention and Prevention

Alcohol use, particularly binge drinking (BD), is a major public health concern among adolescents. Recent national data show that the gender gap in alcohol use is lessening, and BD among girls is rising. Considering the increase in BD among adolescent girls, as well as females' increased risk of experiencing more severe biopsychosocial negative effects and consequences from BD, the current review sought to examine gender differences in risk factors for BD. The review highlights gender differences in (1) developmental-related neurobiological vulnerability to BD, (2) psychiatric comorbidity and risk phenotypes for BD, and (3) social-related risk factors for BD among adolescents, as well as considerations for BD prevention and intervention. Most of the information gleaned thus far has come from preclinical research. However, it is expected that, with recent advances in clinical imaging technology, neurobiological effects observed in lower mammals will be confirmed in humans and vice versa. A synthesis of the literature highlights that males and females experience unique neurobiological paths of development, and although there is debate regarding the specific nature of these differences, literature suggests that these differences in turn influence gender differences in psychiatric comorbidity and risk for BD. For one, girls are more susceptible to stress, depression, and other internalizing behaviors and, in turn, these symptoms contribute to their risk for BD. On the other hand, males, given gender differences across the lifespan as well as gender differences in development, are driven by an externalizing phenotype for risk of BD, in part, due to unique paths of neurobiological development that occur across adolescence. With respect to social domains, although social and peer influences are important for both adolescent males and females, there are gender differences. For example, girls may be more sensitive to pressure from peers to fit in and impress others, while male gender role stereotypes regarding BD may be more of a risk factor for boys. Given these unique differences in male and female risk for BD, further research exploring risk factors, as well as tailoring intervention and prevention, is necessary. Although recent research has tailored substance use intervention to target males and females, more literature on gender considerations in treatment for prevention and intervention of BD in particular is warranted.
Pressure Dependence of Optical Transitions in InGaN/GaN Multiple Quantum Wells

The effect of hydrostatic pressure on optical transitions in InGaN/GaN multiple quantum wells (MQWs) has been studied. Photoluminescence (PL) and photomodulated transmission (PT) measurements were performed under applied pressure to examine the pressure dependence of optical transitions associated with confined states in MQWs. The PL emission from the MQWs was found to shift linearly to higher energy with applied pressure but exhibit a significantly weaker pressure dependence compared to epilayer samples with similar bandgap energies. Similar pressure coefficients obtained by PT measurements rule out the possibility of PL resulting from deep localized states. We show that the difference in the compressibility of InGaN and of GaN induces a tensile strain in the compressively strained InGaN well layers that partially compensates the applied hydrostatic pressure. This mechanical effect is the primary factor for the smaller pressure dependence of the optical transitions in the InGaN/GaN MQWs. At pressure above 100 kbar, the PL signal in MQWs samples is quenched, indicating that the carriers involved in the radiative recombination processes in the well layers originate primarily from the adjacent GaN layers.
The Reactor: A fast and sample-efficient Actor-Critic agent for Reinforcement Learning.

In this work we present a new agent architecture, called Reactor, which combines multiple algorithmic and architectural contributions to produce an agent with higher sample-efficiency than Prioritized Dueling DQN (Wang et al., 2016) and Categorical DQN (Bellemare et al., 2017), while giving better run-time performance than A3C (Mnih et al., 2016). Our first contribution is a new policy evaluation algorithm called Distributional Retrace, which brings multi-step off-policy updates to the distributional reinforcement learning setting. The same approach can be used to convert several classes of multi-step policy evaluation algorithms designed for expected value evaluation into distributional ones. Next, we introduce the \b{eta}-leave-one-out policy gradient algorithm which improves the trade-off between variance and bias by using action values as a baseline. Our final algorithmic contribution is a new prioritized replay algorithm for sequences, which exploits the temporal locality of neighboring observations for more efficient replay prioritization. Using the Atari 2600 benchmarks, we show that each of these innovations contribute to both the sample efficiency and final agent performance. Finally, we demonstrate that Reactor reaches state-of-the-art performance after 200 million frames and less than a day of training.
Finance and Business Cycles: The Credit-Driven Household Demand Channel

What is the role of the financial sector in explaining business cycles? This question is as old as the field of macroeconomics, and an extensive body of research conducted since the Global Financial Crisis of 2008 has offered new answers. The specific idea put forward in this article is that expansions in credit supply, operating primarily through household demand, have been an important driver of business cycles. We call this the credit-driven household demand channel. While this channel helps explain the recent global recession, it also describes economic cycles in many countries over the past 40 years.
Nonlinear thermally buckled piezoelectric energy harvester

A thermally buckled piezoelectric energy harvester is designed to power biomedical devices inside the body. The energy harvester (EN) uses the vibrations inside the body to generate the electricity needed for powering biomedical sensors and devices. The piezoelectric beam consists of a brass substrate and two piezoelectric patches attached to the top and the bottom of the substrate. The bimorph beam is inside a rigid frame. The bimorph beam is buckled due to the difference in the coefficient of the thermal expansion of the beam and the frame. Inside the body, most of the energy content come from the low-frequency vibrations (less than 50 Hz). Having high natural frequency is a major problem in Microelectromechanical systems (MEMS) energy harvesters. Considering the small size of the EN, 1 cm3, the natural frequency is expected to be high. In our design, the natural frequency is lowered significantly by using a buckled beam. A mass is also used in the middle of the beam to decrease the natural frequency even more. Since the beam is buckled, the design is bistable and nonlinear which increases the output power. In this paper, the natural frequencies and mode shapes of the EN are analytically derived. The geometric nonlinearities are included in the electromechanical coupled governing equations. The governing equations are solved and it is shown that the device generates sufficient electricity to power biomedical sensors and devices inside the human body.
Object‐based Learning in a World Dress Course

Object-based learning (OBL) is an active-learning teaching approach that uses artifacts as teaching tools in the classroom. The purpose of this study was to examine the effectiveness of an OBL assignment in teaching students about unfamiliar items of dress. Students were enrolled in a world dress general education course at a university in the Midwest United States. Researchers analyzed student responses from one OBL assignment to examine its effectiveness in teaching students about a item of dress from Uzbekistan. Students in general appreciated the use of OBL as they gained additional knowledge about the object, from gaining new insights into fabrics to interest in seeing the object's details, different perspective views, and construction methods. Findings concluded that OBL was an effective tool for this course. Based on this analysis, the OBL assignment will continue to be used as a teaching tool in the course.
Statistical Non-Significance in Empirical Economics

Significance tests are probably the most common form of inference in empirical economics, and significance is often interpreted as providing greater informational content than non-significance. In this article we show, however, that rejection of a point null often carries very little information, while failure to reject may be highly informative. This is particularly true in empirical contexts that are typical and even prevalent in economics, where data sets are large (and becoming larger) and where there are rarely reasons to put substantial prior probability on a point null. Our results challenge the usual practice of conferring point null rejections a higher level of scientific significance than non-rejections. In consequence, we advocate a visible reporting and discussion of non-significant results in empirical practice.