cssi/SciSciGPT-SciSciNet huggingface dataset:
Automated chain line marking and pattern matching in radiographs of Rembrandt's prints

The sieve-like molds used in early paper manufacturing leave characteristic chain line patterns that can help determine if two pieces of paper were made using the same mold [1]. Such moldmates can help in establishing chronology, suggest paper preferences, and indicate periods of intense activity of an artist, and the study of Rembrandt's prints has occupied a prominent place within this scholarship [2]. There are two basic steps to the automation of the analysis [3], [4]. First, the chain lines must be accurately marked, extracting points and lines from the x-ray images. Second, the markings from many x-rays must be compared to find matches. This paper presents improved algorithms for both of these tasks. Section II follows [6] in replacing the classic Radon transform approach of [5] (which requires that the chain lines be straight) with a local method that outputs marked grids of points. The method segments the images, corrects for tilt, filters, conducts a (local) Radon transform and then concludes with a peak detection. The marked grids from a large collection of x-rays of Rembrandt's prints are then used in Section III as input to the matching algorithm.
Defining an effective point of radiation for a microstrip patch antenna

In many high-precision GPS applications, accuracies on the cm level are required. However, due to the nature of GPS measurements, the signal transmitted by the satellite traverses the ionosphere and troposphere, along a different path for each incident (observation) angle, before it is detected by the receiving antenna on earth. Thus, in addition to the delay the GPS signal experiences associated with the path length between the satellite and the receiver, the signal also undergoes an additional timing delay due to the complicated nature of the propagation medium [1]. While the effects of these delays (phase errors) are typically minimized by using differential GPS techniques [1], an additional timing delay that is often neglected is associated with the variation in the antenna's effective point of radiation (“phase center”) as a function of the observation angle. Even with differential correction of the ionospheric and tropospheric phase errors, the timing delay associated with the phase center variation can degrade the positional accuracy of precision GPS measurements. Hence, a thorough characterization of the effective point of radiation for a GPS antenna is important.
A self-powered sensor patch for glucose monitoring in sweat

We developed a paper-based self-powered sensor patch for detecting glucose levels in sweat. This wearable, non-invasive biosensor made use of the integration of a vertically stacked paper-based glucose/oxygen enzymatic fuel cell into a standard Band-Aid patch. The paper-based device, attached directly to human skin, wicked sweat from human skin and monitored an electrochemical energy conversion as a transducing element for glucose monitoring in sweat, thus obviating the requirement of external power sources and sophisticated readout instrumentation. The device features (i) a 3-D origami paper-based fuel cell structure for easy system integration on paper, (ii) an electrically conducting paper microfluidic reservoir for high anode surface area and efficient mass transfer, and (iii) a direct electron transfer between enzymes and electrodes for enhanced electron discharge properties. The sensor showed a linear range of output current at 0.02–1.0mg/mL glucose (R2=0.989) with a high sensitivity.
Cpeb4-Mediated Translational Regulatory Circuitry Controls Terminal Erythroid Differentiation

Abstract While we have considerable understanding of the transcriptional networks controlling mammalian cell differentiation, our knowledge of post-transcriptional regulatory events is very limited. Using differentiation of primary erythroid cells as a model, we show that the sequence-specific mRNA-binding protein Cpeb4 is induced by the erythroid important transcription factors Gata1 and Tal1, is strongly upregulated during terminal erythroid development, and is essential for terminal erythropoiesis. By binding directly to the translation initiation factor eIF3 complex, Cpeb4 represses the translation of a large set of mRNAs, most of which are normally downregulated during terminal erythroid development. Cpeb4 also binds to its own mRNA to repress its translation, and ectopic expression of Cpeb4 blocks erythroid differentiation. Thus transcriptional induction and translational repression combine to form a negative feedback loop to control Cpeb4 protein levels within a specific range that is required for terminal erythropoiesis. Our study provides an example of how translational control is integrated with transcriptional regulation to precisely control gene expression during mammalian cell differentiation. Disclosures No relevant conflicts of interest to declare.
Control and State Estimation of the One-Phase Stefan Problem via Backstepping Design

This paper develops a control and estimation design for the one-phase Stefan problem. The Stefan problem represents a liquid–solid phase transition as time evolution of a temperature profile in a liquid–solid material and its moving interface. This physical process is mathematically formulated as a diffusion partial differential equation (PDE) evolving on a time-varying spatial domain described by an ordinary differential equation (ODE). The state-dependency of the moving interface makes the coupled PDE-ODE system a nonlinear and challenging problem. We propose a full-state feedback control law, an observer design, and the associated output feedback control law of both Neumann and Dirichlet boundary actuations via the backstepping method. Also, the state-feedback control law is provided when a Robin boundary input is considered. The designed observer allows the estimation of the temperature profile based on the available measurements of liquid-phase length and the heat flux at the interface. The associated output feedback controller ensures the global exponential stability of the estimation errors, the ${\mathcal H}_1$ -norm of the distributed temperature, and the moving interface at the desired setpoint under some explicitly given restrictions on the setpoint and observer gain.
The Importance of Preventive Feedback: Inference from Observations of the Stellar Masses and Metallicities of Milky Way Dwarf Galaxies

Dwarf galaxies are known to have remarkably low star formation efficiency due to strong feedback. Adopting the dwarf galaxies of the Milky Way (MW) as a laboratory, we explore a flexible semi-analytic galaxy formation model to understand how the feedback processes shape the satellite galaxies of the MW. Using Markov Chain Monte Carlo, we exhaustively search a large parameter space of the model and rigorously show that the general wisdom of strong outflows as the primary feedback mechanism cannot simultaneously explain the stellar mass function and the mass–metallicity relation of the MW satellites. An extended model that assumes that a fraction of baryons is prevented from collapsing into low-mass halos in the first place can be accurately constrained to simultaneously reproduce those observations. The inference suggests that two different physical mechanisms are needed to explain the two different data sets. In particular, moderate outflows with weak halo mass dependence are needed to explain the mass–metallicity relation, and prevention of baryons falling into shallow gravitational potentials of low-mass halos (e.g., "pre-heating") is needed to explain the low stellar mass fraction for a given subhalo mass.
Improving information systems productivity: a need for revolution

Current work practices in the development and maintenance of information systems (IS) are inefficient and similar to those found in the automobile industry a century ago. A revolution is needed to bring a quick end to these work practices and to help the IS profession increase its productivity dramatically.
Decomposition analysis to identify intervention targets for reducing disparities

There has been considerable interest in using decomposition methods in epidemiology (mediation analysis) and economics (Oaxaca-Blinder decomposition) to understand how health disparities arise and how they might change upon intervention. It has not been clear when estimates from the Oaxaca-Blinder decomposition can be interpreted causally because its implementation does not explicitly address potential confounding of target variables. While mediation analysis does explicitly adjust for confounders of target variables, it typically does so in a way that effectively entails equalizing confounders across racial groups, which may not reflect the intended intervention. Revisiting prior analyses in the National Longitudinal Survey of Youth on disparities in wages, unemployment, incarceration, and overall health with test scores, taken as a proxy for educational attainment, as a target intervention, we propose and demonstrate a novel decomposition that controls for confounders of test scores (e.g., measures of childhood socioeconomic status [SES]) while leaving their association with race intact. We compare this decomposition with others that use standardization (to equalize childhood SES [the confounders] alone), mediation analysis (to equalize test scores within levels of childhood SES), and one that equalizes both childhood SES and test scores. We also show how these decompositions, including our novel proposals, are equivalent to implementations of the Oaxaca-Blinder decomposition but provide a more formal causal interpretation for these decompositions.
The Information Society

This article briefly discusses various definitions and concepts of the so-called information society. The term information society has been proposed to refer to the post-industrial society in which information plays a pivotal role. The definitions that have been proposed over the years highlight five underlying characterisations of an information society: technological, economic, sociological, spatial, and cultural. This article discusses those characteristics. While the emergence of an information society may be just a figment of one’s imagination, the concept could be a good organising principle to describe and analyse the changes of the past 50 years and of the future in the 21st century.
Touchable Apps: Exploring the Usage of Touch Features and Their Impact on Engagement

Abstract Touch has become an inseparable element of mobile platforms. This study examines the use of different touch features and the impact of these touch gestures on consumer engagement with a mobile shopping app. We focus on three informational touch features that are common among shopping apps: touch to zoom in on a page (zoom-page), to view product details (product-view), and to be directed to outside links (open-webpage). We develop a two-level model that captures (1) consumers' decisions to stay with or leave an app and (2) their use of touch features. Our main results empirically demonstrate the strong explanatory power of informational touch gestures, especially their dwell time, in consumer app browsing decisions, whereas navigational touch gestures do not significantly affect app stay likelihood. A longer dwell time and early use of zoom-page within a session encourage the stay. Moreover, we observe strong synergy and antergy (negative synergy) among these touch gestures. The cumulative dwell time and temporal progression of touch gestures affect subsequent touch feature usage. Managerially, our results suggest that an early intervention that encourages the use of zoom-page increases app stay likelihood, and marketers may apply our model to quantify the impact of such interventions on consumer browsing decisions at the individual level. The results also shed light on how marketers can infer the stage of the shopping process based on touch gestures (segmentation) and guide consumers through the purchase funnel by promoting the use of zoom-page and product-view. Lastly, the findings provide insights into how marketers can promote the use of open-webpage, which has the lowest baseline usage rate yet is crucial for transactions, based on the synergy among touch gestures and through improving the non-native browsing experience.
The impact of advertising along the conversion funnel

We assemble a unique data set that combines information on supermarket feature advertising with path-tracking data on consumers’ movement within the store as well as purchase information. Using these novel data, we trace out how advertising affects consumer behavior along the path-to-purchase. We find advertising has no significant effect on the number of consumers visiting the category being advertised. The null effect is precisely estimated. At the upper bound of the confidence interval, a one-standard-deviation shift in advertising increases category traffic by only 1.3%. We do find a significant effect at the lower end of the conversion funnel. A one-standard-deviation change in advertising (evaluated at the point estimate) increases category-level sales by 10%. We further decompose the impact on sales and find the increase is driven by the same number of consumers buying a larger number of products of the same brand. We find no evidence of spillover effects of advertising between categories that are stocked in proximity of each other, nor between different products in the same category. Two mechanisms are consistent with these patterns: consumers retrieve memory of the ad only when interacting with the category or only consumers wanting to purchase the brand choose to consume the ad.
Factorial experiments when factor levels are not necessarily reset

In industry, the run order of experiments is often randomized, but this does not guarantee that all factor levels are reset from one run to the next. When this happens and the levels of factors are the same in successive runs, the assumption of independent observations from run to run may be violated or incorrect. In this case, an ordinary least squares analysis can produce biased estimates of the coefficients in the model, which leads to erroneous test results and inferences. In this paper we describe how not resetting the levels of one or more factors in successive runs can result in less precision in parameter estimates and a larger than expected prediction variance. We present formulas for the prediction variance and the expected prediction variance for this situation. These quantities are important because they allow us to compare the prediction properties of experiments that are completely randomized to experiments where the levels of one or more factors are not reset. We give an analysis of an industrial experiment of this type and recommendations for carrying out factorial experiments where the levels of one or more factors are not reset.
The Visible Host: Does Race guide Airbnb rental rates in San Francisco?

Abstract Peer to Peer e-commerce is increasingly characterized by trends towards the personalization of buyers and sellers in the on-line marketplace. This personalization includes buyer reviews, personal pictures and profiles, and other biographical information intended to reduce buyers’ perceived “purchase risk” or to facilitate trust in the sellers. However, this phenomenon is transforming what started as an essentially “anonymous” market to one susceptible to traditional market failures, including potential racial discrimination, in a manner similar to its brick and mortar counterparts. In this paper, we examine the effect of on-line host information (race, gender, sexual orientation, etc.) on the price of available rental listings in San Francisco on Airbnb.com. We find that on average, Asian and Hispanic hosts charge 8%-10% lower prices relative to their White counterparts on equivalent rental properties, after controlling for all renter-available information on rental unit characteristics, as well as additional information on neighborhood property values, area demographics, and occupancy rates. We do not find any differences in occupancy rates between minority and White hosts. This may suggest that minorities price lower because they are forward-looking, perhaps due to an expectation of discrimination in the online marketplace or have a preference to increase demand to either maintain their target occupancy level or to attract a larger pool of potential renters to choose from. Overall, our findings are consistent with but not conclusive of a market test of potential racial discrimination affecting Hispanic Airbnb hosts, manifested in an anticipation of disparate market demand for their rentals, and responded to by lower listing prices.
A PROSPECTIVE, RANDOMISED COMPARISON OF MID-FLEXION BALANCE AFTER TOTAL KNEE ARTHROPLASTY WITH SINGLE-RADIUS AND J-CURVE FEMORAL COMPONENTS

Introduction Mid-flexion stability after total knee arthroplasty (TKA) is dependent, in large part, on implant design. Design variables include retention or sacrifice of the posterior cruciate ligament, conformity of the polyethylene tibial surface, and radius of curvature of the femoral component. In this study, we attempted to isolate the impact of femoral component design by comparing a single-radius design (SR) to a J-Curve design (JC). We selected cruciate-retaining implants to eliminate the effect of a cam-and-post mechanism. Mid-flexion performance these two designs were compared using the Lower-Quarter Y-Balance Test (YBT-LQ), as well as patient reported outcomes and measures of physical performance. The YBT-LQ is a simple functional test of unilateral lower extremity strength and balance. Reach of the contralateral limb is measured in three different directions (Figures 1–3). Our hypothesis was that the SR design would provide superior mid-flexion stability, and therefore, a greater reach distance in the YBT-LQ when compared to the JC group. Methods Patients undergoing primary, unilateral TKA were prospectively enrolled and block randomized to receive either the SR (n=30) or JC (n=30) implant. All surgeries were performed by one surgeon using a gap-balancing technique with a cruciate-retaining implant design. Patients completed outcome measures (KOOS, KSS, UCLA Activity), performed the YBT-LQ, and completed physical performance measures (walking speed, timed up-and-go, sit-to-stand) before surgery and 1 year postoperatively. A series of 2×2 repeated measures ANOVAS (Implant group x Time) were completed. Results One year post-operatively, 40 patients (20 SR, 20 JC) were available for analysis. The groups were closely matched for age, gender, BMI, and ASA score. No significant differences existed between implant groups for the YBT-LQ or any other variable of interest. Significant improvements in both implant groups were observed for all variables of interest when comparing pre-operative to one year post-operative. Conclusions Both groups improved significantly across time in all measures, but no differences were seen between SR and JC designs. Based on reach distances achieved, it is probable that many patients were not able to achieve mid-flexion during the YBT-LQ test. With regards to mid-flexion function after TKA, the significant limitations in strength and balance in this cohort of patients likely outweigh any subtle differences in implant design. For any figures or tables, please contact authors directly (see Info & Metrics tab above).
COMPUTER MODELLING IN DIE CASTING APPLICATIONS

Abstract In the context of die casting, computer modelling facilitates the design and manufacturing of parts that often have very complex configurations. The technology offers to the user more wholesome and rapid solutions to die casting problems. When properly applied, it can help to reduce production costs through design and process optimization, and shorten product development cycle time. This paper focuses on modelling the two main aspects of die casting: turbulent metal flow and nonisothermal solidification. Modelling of these two phenomena is undertaken by means of the finite element method (FEM). Flow and solidification patterns are generated from 3D finite element mesh representations of the components being analyzed. The information developed can then be used by the die caster to evaluate and optimize cavity design, predict potential defects in the castings, and formulate manufacturing requirements. Theoretical aspects related to the CASTFILL filling model and CASTSOL solidification model are outlined and examples of flow and solidification simulations of die castings in zinc and aluminum alloys are given.
Licensed Tests for Antibody to Human T-Lymphotropic Virus Type III: Sensitivity and Specificity

Before the discovery of the etiologic agent of the acquired immunodeficiency syndrome (AIDS) substantial epidemiologic evidence suggested that the responsible agent could be transmitted by blood and blood products such as factor VIII. The Public Health Service and the Food and Drug Administration therefore took general steps to increase the safety of the blood supply. With the discovery of the human T-lymphotropic virus type III (HTLV-III) it became possible to test blood for evidence of infection using an antibody detection assay. Currently licensed tests to detect antibody to HTLV-III range in sensitivity between 93% and 99% and all are above 99% in specificity. The Public Health Service has issued provisional recommendations regarding the voluntary use of the antibody tests to screen blood and plasma donations. (authors)
Achievable Performance of Magnetically Levitated Rotating Machines

Abstract An LTR (Loop Transfer Recovery) based procedure is proposed to initiate the integration of design and control and solve the achievable performance problem for magnetically levitated rotating machines, Combining LTR's asymptotic properties and the performance constraints from hardware components, it is possible to investigate the relation between the system bandwidth and the achievable performance more closely. Such an investigation is demonstrated using an existing magnetically levitated turbo pump.
Value of the Gram-Stained Urethral Smear in the Management of Men With Urethritis

The value of the gram-stained urethral smear in clinical decision-making was assessed in a study of 250 men attending a clinic for sexually transmitted diseases. Of the 250 men, 132 (52.8%) had objective evidence of urethritis. Neisseria gonorrhoeae and/or Chlamydia trachomatis was isolated from 94 patients (37.6%). No pathogens were isolated from 38 patients (15.2%) who were diagnosed as having urethritis. Although the specificity (0.95) and positive predictive value (0.95) of the gram smear for culture-proved urethral infection was high, the relatively low sensitivity (0.66) and negative predictive value (0.63), led us to conclude that the test was of limited value in diagnosis and therapeutic decision-making when the patient was first seen. The decision to treat a patient should be based on a reliable history of dysuria and/or a urethral discharge in a patient at risk of infection, with or without an observable urethral discharge. Nevertheless, a gram smear should be done for all patients who are diagnosed presumptively as having urethritis, because it may be the only objective evidence of urethritis.
Space Efficient Breadth-First and Level Traversals of Consistent Global States of Parallel Programs

Enumerating consistent global states of a computation is a fundamental problem in parallel computing with applications to debugging, testing and runtime verification of parallel programs. Breadth-first search (BFS) enumeration is especially useful for these applications as it finds an erroneous consistent global state with the least number of events possible. The total number of executed events in a global state is called its rank. BFS also allows enumeration of all global states of a given rank or within a range of ranks. If a computation on n processes has m events per process on average, then the traditional BFS (Cooper-Marzullo and its variants) requires \(\mathcal {O}(\frac{m^{n-1}}{n})\) space in the worst case, whereas our algorithm performs the BFS requires \(\mathcal {O}(m^2n^2)\) space. Thus, we reduce the space complexity for BFS enumeration of consistent global states exponentially, and give the first polynomial space algorithm for this task. In our experimental evaluation of seven benchmarks, traditional BFS fails in many cases by exhausting the 2 GB heap space allowed to the JVM. In contrast, our implementation uses less than 60 MB memory and is also faster in many cases.
SURFACE POTENTIAL AS A LASER DAMAGE DIAGNOSTIC.

We investigated the relationship between surface potential changes and N-on-1 laser surface damage on a wide range of materials. The surface potential or work function difference was measured as a function of position by a small non-contacting Kelvin type probe. The design and operation of the probe is described. With this probe, the change in surface potential due to laser irradiation was mapped with a '1,1 mm resolution. Although no consistent predamage changes in potential were observed, all larger damage features had surface potential changes associated with them. All the insulating materials studied, fluoride and oxide thin films and bare fused silica and magnesium fluoride substrates, showed the accumulation of negative charge in areas more than ten times larger in diameter than the laser beam spot or damage area. This initial charge was observed to decay on the time scale of hours to a lower fixed value of potential.
Well trajectory effect on slug flow development

Abstract The effect of horizontal well trajectory on slug flow development was experimentally studied using a 2.0 in. ID flow loop to mimic different well trajectories. Inclination angle in the lateral section was varied ±1° from the horizontal to simulate three well configurations, namely, toe-down, one-undulation with a sump, and one-undulation with a hump. Slug length and frequency along the well were measured using fourteen conductivity probes located along the test section. Experimental results indicated that slug length in the vertical and lateral sections of a well present values up to four and two times, respectively, larger than typical dimensionless slug length reported in the literature. Furthermore, slug flow development along the vertical section is affected by the lateral section deviation angle and length. At the same time, lateral section slug flow development is affected by liquid fall back from the vertical section and lateral section length. Slug characterization along the well is critical to properly design and operate downhole and surface equipment and properly predict pressure gradient and liquid holdup along the well.
Aggregation, Structural Change, and Cross-Section Estimation

Abstract This article characterizes the local effects of parametric behavioral model change on relationships between aggregate variables, and it presents consistent estimators of such effects using cross-section data. Two equivalent interpretations of model-change effects are given: an “average-marginal” formulation and a cross-section regression formulation. The relation between model-change effects and maximum likelihood estimation of the behavioral parameters is explained. Finally, the article addresses the question of whether R 2 [from a crosssection ordinary least squares (OLS) regression] is a general measure of the sensitivity of aggregate relationships to model-change effects.
Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments

Abstract. The use of low-cost air quality sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions, and there is thus a critical need for understanding and optimizing the performance of such sensors in the field. Here we describe the deployment, calibration, and evaluation of electrochemical sensors on the island of Hawai`i, which is an ideal test bed for characterizing such sensors due to its large and variable sulfur dioxide (SO2) levels and lack of other co-pollutants. Nine custom-built SO2 sensors were co-located with two Hawaii Department of Health Air Quality stations over the course of 5 months, enabling comparison of sensor output with regulatory-grade instruments under a range of realistic environmental conditions. Calibration using a nonparametric algorithm (k nearest neighbors) was found to have excellent performance (RMSE 0.997) across a wide dynamic range in SO2 ( 2 ppm). However, since nonparametric algorithms generally cannot extrapolate to conditions beyond those outside the training set, we introduce a new hybrid linear–nonparametric algorithm, enabling accurate measurements even when pollutant levels are higher than encountered during calibration. We find no significant change in instrument sensitivity toward SO2 after 18 weeks and demonstrate that calibration accuracy remains high when a sensor is calibrated at one location and then moved to another. The performance of electrochemical SO2 sensors is also strong at lower SO2 mixing ratios (
The role of electron-phonon interactions on the coherence lifetime of monolayer transition metal dichalcogenides

Abstract We investigate the excitonic dephasing of transition metal dichalcogenides, namely MoS 2 , MoSe 2 and WSe 2 atomic monolayer thick and bulk crystals, in order to understand the factors that determine the optical coherence in these materials. Coherent nonlinear optical spectroscopy, temperature dependent absorption combined with theoretical calculations of the phonon spectra, reveal the important role electron-phonon interactions plat in dephasing process. The temperature dependence of the electronic band gap and the excitonic linewidth combined with ‘ ab initio ’ calculations of the phonon energies and the phonon density of state reveal strong interaction with the E′ and E″ phonon modes.
Selecting efficient correlated equilibria through distributed learning

Abstract A learning rule is completely uncoupled if each player's behavior is conditioned only on his own realized payoffs, and does not need to know the actions or payoffs of anyone else. We demonstrate a simple, completely uncoupled learning rule such that, in any finite normal form game with generic payoffs, the players' realized strategies implements a socially optimal coarse correlated (Hannan) equilibrium a very high proportion of the time. That is, the empirical frequency associated with the players' collective behavior will be consistent with a socially optimal coarse correlated equilibrium. A variant of the rule implements a socially optimal correlated equilibrium a very high proportion of the time.
Effectiveness and efficiency of adding drawing prompts to an interactive educational technology when learning with visual representations

Abstract This paper investigates whether prompting students to draw their own visual representations enhances students’ learning from technology-based instructional activities with visual representations. Seventy-two undergraduate students were randomly assigned to receive an educational technology with (1) drawing prompts throughout instruction, (2) drawing prompts before and after instruction, or (3) no drawing prompts. We assessed learning outcomes with respect to instructional effectiveness and efficiency using immediate and delayed posttests. Results on instructional efficiency showed a significant advantage for drawing prompts. Results on instructional effectiveness showed an advantage at the delayed posttest for drawing prompts provided throughout instruction, compared to prompts before and after. Qualitative analyses suggest that adding drawing prompts throughout instruction promotes drawing quality. In sum, our findings expand theory by suggesting that drawing prompts facilitate visual sense making of concepts shown in visual representations. Furthermore, we provide practical recommendations on how best to implement drawing prompts with technology-based instructional activities.
Academic Vocabulary Learning in First Through Third Grade in Low-Income Schools: Effects of Automated Supplemental Instruction.

Purpose This study investigated cumulative effects of language learning, specifically whether prior vocabulary knowledge or special education status moderated the effects of academic vocabulary ins...
Information Flow under Budget Constraints

Although first proposed in the database theory as properties of functional dependencies between attributes, Armstrong’s axioms capture general principles of information flow by describing properties of dependencies between sets of pieces of information. This article generalizes Armstrong’s axioms to a setting in which there is a cost associated with information. The proposed logical system captures general principles of dependencies between pieces of information constrained by a given budget.
Opioid Crisis: No Easy Fix to Its Social and Economic Determinants

The accepted wisdom about the US overdose crisis singles out prescribing as the causative vector. Although drug supply is a key factor, we posit that the crisis is fundamentally fueled by economic and social upheaval, its etiology closely linked to the role of opioids as a refuge from physical and psychological trauma, concentrated disadvantage, isolation, and hopelessness.Overreliance on opioid medications is emblematic of a health care system that incentivizes quick, simplistic answers to complex physical and mental health needs. In an analogous way, simplistic measures to cut access to opioids offer illusory solutions to this multidimensional societal challenge.We trace the crisis’ trajectory through the intertwined use of opioid analgesics, heroin, and fentanyl analogs, and we urge engaging the structural determinants lens to address this formidable public health emergency. A broad focus on suffering should guide both patient- and community-level interventions.
Étale covers of affine spaces in positive characteristic

Abstract We prove that every projective, geometrically reduced scheme of dimension n over an infinite field k of positive characteristic admits a finite morphism over some finite radicial extension k′ of k to projective n-space, etale away from the hyperplane H at infinity, which maps a chosen Weil divisor into H and a chosen smooth geometric point of X not on the divisor to some point not in H. To cite this article: K.S. Kedlaya, C. R. Acad. Sci. Paris, Ser. I 335 (2002) 921–926.
Bol loops and Bruck loops of order pq up to isotopism

Abstract Let p > q be odd primes. We classify Bol loops and Bruck loops of order pq up to isotopism. When q does not divide p 2 − 1 , the only Bol loop (and hence the only Bruck loop) of order pq is the cyclic group of order pq. When q divides p 2 − 1 , there are precisely ⌊ ( p − 1 + 4 q ) ( 2 q ) − 1 ⌋ Bol loops of order pq up to isotopism, including a unique nonassociative Bruck loop of order pq.
Enhancing risk management for an aging world

As the world confronts unprecedented global aging, academics and policymakers are growing increasingly aware of the need for better risk management tools to handle the demographic transition. It is therefore imperative to identify innovative insurance and financial market products that can enrich the range of options for households, firms, and governments facing the challenge of an aging population. After outlining thoughts on how rising longevity might shape financial markets, we discuss opportunities for the finance and insurance industries in this arena. We also highlight how policymakers could respond to improve efforts to better manage risk.
Ideology Meets Reality: What Works and What Doesn't in Patient Exposure to Health Care Costs

U.S. policymakers, scholars, and advocates have long displayed an ideological commitment to exposing insured patients to substantial out-of-pocket expenses. These commitments derive from both overt political ideologies, which favor individual responsibility and oppose redistribution of wealth and risks, as well as more-subtle ideological commitments of academic economists, which link observed patterns of consumption to value-claims about welfare. In this symposium contribution, we document those ideological commitments and juxtapose them with a review of the scientific evidence about the actual effects of patient cost-sharing. We find, as economic theory predicts, that patients exposed to healthcare costs consume less healthcare. However, a fair review of the evidence — including the effects on health outcomes, access to care, and financial insecurity — makes it very hard to conclude that substantial and untailored cost-sharing exposure — as we have seen in actual application — is good social policy. We suggest directions for future study and reform.
Approximating the online set multicover problems via randomized winnowing

In this paper, we consider the weighted online set k-multicover problem. In this problem, we have a universe V of elements, a family S of subsets of V with a positive real cost for every [email protected]?S, and a ''coverage factor'' (positive integer) k. A subset {i"0,i"1,...}@?V of elements are presented online in an arbitrary order. When each element i"p is presented, we are also told the collection of all (at least k) sets S"i"""[email protected]?S and their costs to which i"p belongs and we need to select additional sets from S"i"""p if necessary such that our collection of selected sets contains at leastk sets that contain the element i"p. The goal is to minimize the total cost of the selected sets. In this paper, we describe a new randomized algorithm for the online multicover problem based on a randomized version of the winnowing approach of [N. Littlestone, Learning quickly when irrelevant attributes abound: A new linear-threshold algorithm, Machine Learning 2 (1988) 285-318]. This algorithm generalizes and improves some earlier results in [N. Alon, B. Awerbuch, Y. Azar, N. Buchbinder, J. Naor, A general approach to online network optimization problems, in: Proceedings of the 15th ACM-SIAM Symposium on Discrete Algorithms, 2004, pp. 570-579; N. Alon, B. Awerbuch, Y. Azar, N. Buchbinder, J. Naor, The online set cover problem, in: Proceedings of the 35th Annual ACM Symposium on the Theory of Computing, 2003, pp. 100-105]. We also discuss lower bounds on competitive ratios for deterministic algorithms for general k based on the approaches in [N. Alon, B. Awerbuch, Y. Azar, N. Buchbinder, J. Naor, The online set cover problem, in: Proceedings of the 35th Annual ACM Symposium on the Theory of Computing, 2003, pp. 100-105].
View Selection with Geometric Uncertainty Modeling

Estimating positions of world points from features observed in images is a key problem in 3D reconstruction, image mosaicking,simultaneous localization and mapping and structure from motion. We consider a special instance in which there is a dominant ground plane $\mathcal{G}$ viewed from a parallel viewing plane $\mathcal{S}$ above it. Such instances commonly arise, for example, in aerial photography. Consider a world point $g \in \mathcal{G}$ and its worst case reconstruction uncertainty $\varepsilon(g,\mathcal{S})$ obtained by merging \emph{all} possible views of $g$ chosen from $\mathcal{S}$. We first show that one can pick two views $s_p$ and $s_q$ such that the uncertainty $\varepsilon(g,\{s_p,s_q\})$ obtained using only these two views is almost as good as (i.e. within a small constant factor of) $\varepsilon(g,\mathcal{S})$. Next, we extend the result to the entire ground plane $\mathcal{G}$ and show that one can pick a small subset of $\mathcal{S'} \subseteq \mathcal{S}$ (which grows only linearly with the area of $\mathcal{G}$) and still obtain a constant factor approximation, for every point $g \in \mathcal{G}$, to the minimum worst case estimate obtained by merging all views in $\mathcal{S}$. Finally, we present a multi-resolution view selection method which extends our techniques to non-planar scenes. We show that the method can produce rich and accurate dense reconstructions with a small number of views. Our results provide a view selection mechanism with provable performance guarantees which can drastically increase the speed of scene reconstruction algorithms. In addition to theoretical results, we demonstrate their effectiveness in an application where aerial imagery is used for monitoring farms and orchards.
The Production of Corporate Research to Manufacture Doubt About the Health Hazards of Products: An Overview of the Exponent Bakelite® Simulation Study.

Although corporate sponsorship of research does not necessarily lead to biased results, in some industries, it has resulted in the publication of inaccurate and misleading data. Some companies have...
Measuring pH of the Coxiella burnetii Parasitophorous Vacuole

Coxiella burnetii is the causative agent of human Q fever, a zoonotic disease that can cause a debilitating, flu-like illness in acute cases, or a life-threatening endocarditis in chronic patients. An obligate intracellular bacterial pathogen, Coxiella survives and multiplies in a large lysosome-like vacuole known as the Coxiella parasitophorous vacuole (CPV). A unique characteristic of the CPV is the acidic environment (pH ∼5.0), which is required to activate Coxiella metabolism and the Coxiella type 4 secretion system (T4SS), a major virulence factor required for intracellular survival. Further, inhibiting or depleting vacuolar ATPase, a host cell protein that regulates lysosomal pH, inhibits intracellular Coxiella growth. Together, these data suggest that CPV pH is an important limiting factor for Coxiella growth and virulence. This unit describes a method to determine CPV pH using live cell microscopy of a pH-sensitive fluorophore conjugated to dextran. This technique is useful to measure changes in CPV pH during infection or in response to drug treatment. © 2017 by John Wiley & Sons, Inc.
First measurement of prenucleation molecular clusters

The molecular cluster ions HSO{sub 4}{sup {minus}}(H{sub 2}SO{sub 4}){sub n{minus}1} corresponding to the neutral species (H{sub 2}SO{sub 4}){sub n} for n = 3--8 have been observed using a transverse chemical ionization scheme located inside a cooled flow tube. The contribution of ion-molecule clustering reactions was ascertained and readily separated from the ionization of the neutral clusters. The presence of the clusters was strongly dependent on temperature and humidity. Ratios of successive clusters thought to be representative of steady-state are reported.
Evaluation of the pulmonary embolism rule out criteria (PERC rule) in children evaluated for suspected pulmonary embolism.

Abstract Background The pulmonary embolism rule out criteria (PERC) reliably predicts a low probability of PE in adults. We examine the diagnostic accuracy of the objective components of the PERC rule in children previously tested for PE. Methods Children aged 5–17 who had a D-dimer or pulmonary vascular imaging ordered from 2004 to 2014 in a large multicenter hospital network were identified by query of administrative databases. Using explicit, predefined methods, trained abstracters selected charts of children clearly tested for PE, collected the 8 objective variables for PERC, and determined PE criterion standard status (image or autopsy confirmed PE or deep vein thrombosis within 30 days by query of the Indiana Network for Patient Care (INPC)). Results We identified 543 patients, including 56 (10.3%, 95% CI: 7.8–13.1%) who were PE+, with a mean and median age of 15 years. All 8 objective criteria from PERC were negative in 170 patients (31%), including one with PE (false negative rate 0.6%, 0–3.2%). Diagnostic sensitivity and specificity were 98.2% (90.5–100%), and 34.7 (30.5–39.1%), respectively, leading to a likelihood ratio negative = 0.05 (0.1–0.27). When treated as a diagnostic test based upon sum of criteria positive, PERC had good discrimination between PE+ vs PE− with an area under receiver operating characteristic curve 0.81 (0.75–0.86). Conclusions In this sample of children and teenagers with suspected PE, the PERC rule was negative in 31%, and demonstrated good overall diagnostic accuracy, including a low false negative rate. These data support the need for a large, prospective diagnostic validation study of PERC in children.
Non-biological synthetic spike-in controls and the AMPtk software pipeline improve mycobiome data

High-throughput amplicon sequencing (HTAS) of conserved DNA regions is a powerful technique to characterize microbial communities. Recently, spike-in mock communities have been used to measure accuracy of sequencing platforms and data analysis pipelines. To assess the ability of sequencing platforms and data processing pipelines using fungal internal transcribed spacer (ITS) amplicons, we created two ITS spike-in control mock communities composed of cloned DNA in plasmids: a biological mock community, consisting of ITS sequences from fungal taxa, and a synthetic mock community (SynMock), consisting of non-biological ITS-like sequences. Using these spike-in controls we show that: (1) a non-biological synthetic control (e.g., SynMock) is the best solution for parameterizing bioinformatics pipelines, (2) pre-clustering steps for variable length amplicons are critically important, (3) a major source of bias is attributed to the initial polymerase chain reaction (PCR) and thus HTAS read abundances are typically not representative of starting values. We developed AMPtk, a versatile software solution equipped to deal with variable length amplicons and quality filter HTAS data based on spike-in controls. While we describe herein a non-biological SynMock community for ITS sequences, the concept and AMPtk software can be widely applied to any HTAS dataset to improve data quality.
Hilbert–Poincaré series for spaces of commuting elements in Lie groups

In this article we study the homology of spaces $$\mathrm{Hom}({\mathbb Z}^n,G)$$ of ordered pairwise commuting n-tuples in a Lie group G. We give an explicit formula for the Poincare series of these spaces in terms of invariants of the Weyl group of G. By work of Bergeron and Silberman, our results also apply to $$\mathrm{Hom}(F_n/\Gamma _n^m,G)$$ , where the subgroups $$\Gamma _n^m$$ are the terms in the descending central series of the free group $$F_n$$ . Finally, we show that there is a stable equivalence between the space $$\mathrm{Comm}(G)$$ studied by Cohen–Stafa and its nilpotent analogues.
Rewards in public administration: A proposed classification

Abstract. Social and administrative sciences categorize rewards with some dimensions. However, these interpretative models seem to be elusive because they do not consider all the elements of rewards system within public administration. The goal of this paper is to suggest a new classification considering formality, tangibility and also legality in order to create a comprehensive interpretative model in public sector. This theoretical framework begins the process of clarifying and generalizing, as far as possible, the manifold elements of rewards system in public administration to lay a foundation for the development of more sophisticated taxonomies and theories directed to fruitful management implications. Keywords. Monetary rewards, Compensation, Salary, Seat of power, Pay, Bribe, Reputation, Abuse of power. JEL. B29, L29, L30, L32, M12, M19, M50.
Best-Value Procurement in Design-Bid-Build Construction Projects: Empirical Analysis of Selection Outcomes

AbstractBest-value (BV) procurement is increasingly used in conventional design-bid-build (DBB) delivery, which raises questions regarding the influence of qualifications-based evaluation criteria ...