cssi/SciSciGPT-SciSciNet huggingface dataset:
Regular Policies in Abstract Dynamic Programming

We consider challenging dynamic programming models where the associated Bellman equation, and the value and policy iteration algorithms commonly exhibit complex and even pathological behavior. Our analysis is based on the new notion of regular policies. These are policies that are well-behaved with respect to value and policy iteration, and are patterned after proper policies, which are central in the theory of stochastic shortest path problems. We show that the optimal cost function over regular policies may have favorable value and policy iteration properties, which the optimal cost function over all policies need not have. We accordingly develop a unifying methodology to address long standing analytical and algorithmic issues in broad classes of undiscounted models, including stochastic and minimax shortest path problems, as well as positive cost, negative cost, risk-sensitive, and multiplicative cost problems.
Compensation Discrimination: an Analysis of Linebackers, Defensive Linemen, and Defensive Backs in the National Football League

Previous studies have analyzed compensation discrimination in the National Football League with mixed results. We examine the market for defensive players: defensive linemen, linebackers, and defensive backs and find some evidence of discrimination against Black linebackers. We do not find any evidence of discrimination against Black defensive linemen and defensive backs. Our results provide some support for the hypothesis that employers, employees, or customers discriminate against Black linebackers due to prejudice against Black players who have to make decisions that play a major role in the success of the entire defense.
Measuring Consumer Preferences for Video Content Provision Via Cord‐Cutting Behavior

The television industry is undergoing a generational shift in structure; however, many demand-side determinants are still not well understood. We model how consumers choose video content provision among over-the-air (OTA), paid subscription to cable or satellite, and online streaming (also known as over-the-top, or OTT). We apply our model to a U.S. data set encompassing both the digital switchover for OTA and the emergence of OTT, along with a recession, and use it to analyze cord-cutting behavior (i.e., dropping of cable/satellite subscriptions). We find high levels of cord cutting during this time, and evidence that it became relatively more prevalent among low-income and younger households—suggesting this group responded to changes in OTA and streaming options. We find little evidence of households weighing relative content offerings/quality when choosing their means of video provision during the timespan of our data. This last finding has important ramifications for strategic interaction between content providers.
PERI-PROSTHETIC FX'S: REPAIR OR REPLACE?

Vancouver A: If minimal displacement and prosthesis stable can treat nonoperatively. If displacement is unacceptable and/or osteolysis is present consider surgery. AL: Rare, avulsions from osteopenia and lysis. If large, displaced and include large portion of calcar-can destabilise stem and prompt femoral revision. AG: More common. Often secondary to lysis. Does not usually affect implant stability. Minimal displacement. Treat closed × 3 months. Revise later is needed to remove the particle generator, debride defects and bone graft. Displaced with good host bone stock. Consider early ORIF and bone grafting. Vancouver B: B1: Rarely non-operative. ORIF with femoral component retention. Need to carefully identify stem fixation. B29s classified as B19s are doomed to fail. B19s correctly identified treated with plate, allograft struts or both. High union rates with component retention. B2: Femoral revision +/− strut allograft. Best results seen with patients revised with uncemented, extensively porous coated femoral stems. May use modular, fluted taper stems. B3: Proximal femoral replacement - Tumor prosthesis, Allograft Prosthetic Composite (APC). Uncemented femoral stem - Extensively porous coated, Fluted, tapered stem, Allograft strut. Vancouver C: Treat with standard fracture techniques. These fractures are away from the femoral prosthesis. Rarely nonoperative. Fixation options – Cerclage, Strut Allograft, Plate fixation, Retrograde IM nail, or a Combination thereof. Avoid stress risers between implants. Bypass (overlap) fixation. Consider allowing 2.5 cortical diameters between devices.
Combustion effects of a staged transverse jet and pulsed detonation in supersonic crossflow

The combustion effects of a H2/O2 pulsed detonation (PD) staged downstream of a primary transverse H2 jet in supersonic crossflow (JICF) was investigated. A Mach 2.35 crossflow representative of Mach 7 flight combustor entry conditions (T∞=1330K, P∞=40kPa) was considered. The jet-to-crossflow momentum flux ratio (Jj) of the primary jet was varied between 0.5 and 5.0 to span different stabilization modes. The PD provides a short-duration, high temperature and momentum, radical-rich plume of gas to the wake of the primary transverse jet. The temporal evolution of the interaction between the two plumes was studied using high-speed schlieren and OH* chemiluminescence imaging. Phase-locked OH planar laser-induced fluorescence imaging was used to identify the instantaneous reaction zone along the center-plane at various times of the blowdown process. It was found that the interaction of the two plumes promotes earlier ignition and release of heat. The presence of a high momentum flux ratio transverse jet increases the effective blowdown period (EBP) over which OH* is exhausted; thus increasing the duration of the effects of the PD on the JICF. Lastly, the penetration of the reacting layer into the crossflow was observed to increase with the staged PD present as compared to cases without it.
Intrinsic Phonon Bands in High-Quality Monolayer T′ Molybdenum Ditelluride

The topologically nontrivial and chemically functional distorted octahedral (T′) transition-metal dichalcogenides (TMDCs) are a type of layered semimetal that has attracted significant recent attention. However, the properties of monolayer (1L) T′-TMDC, a fundamental unit of the system, are still largely unknown due to rapid sample degradation in air. Here we report that well-protected 1L CVD T′-MoTe2 exhibits sharp and robust intrinsic Raman bands, with intensities about 1 order of magnitude stronger than those from bulk T′-MoTe2. The high-quality samples enabled us to reveal the set of all nine even-parity zone-center optical phonons, providing reliable fingerprints for the previously elusive crystal. By performing light polarization and crystal orientation resolved scattering analysis, we can effectively distinguish the intrinsic modes from Te-metalloid-like modes A (∼122 cm–1) and B (∼141 cm–1), which are related to the sample degradation. Our studies offer a powerful nondestructive method for assessi...
Discrete-event simulation of fluid stochastic Petri nets

The purpose of this paper is to describe a method for the simulation of the recently introduced fluid stochastic Petri nets. Since such nets result in rather complex system of partial differential equations, numerical solution becomes a formidable task. Because of a mixed (discrete and continuous) state space, simulative solution also poses some interesting challenges, which are addressed in the paper.
Amyloid and intracellular accumulation of BRI2.

Familial British dementia (FBD) and familial Danish dementia (FDD) are caused by mutations in the BRI2 gene. These diseases are characterized clinically by progressive dementia and ataxia and neuropathologically by amyloid deposits and neurofibrillary tangles. Herein, we investigate BRI2 protein accumulation in FBD, FDD, Alzheimer disease and Gerstmann-Straussler-Scheinker disease. In FBD and FDD, we observed reduced processing of the mutant BRI2 pro-protein, which was found accumulating intracellularly in the Golgi of neurons and glial cells. In addition, we observed an accumulation of a mature form of BRI2 protein in dystrophic neurites, surrounding amyloid cores. Accumulation of BRI2 was also observed in dystrophic neurites of Alzheimer disease and Gerstmann-Straussler-Scheinker disease cases. Although it remains to be determined whether intracellular accumulation of BRI2 may lead to cell damage in these degenerative diseases, our study provides new insights into the role of mutant BRI2 in the pathogenesis of FBD and FDD and implicates BRI2 as a potential indicator of neuritic damage in diseases characterized by cerebral amyloid deposition.
Adaptive actuator compensation control with feedback linearization

An adaptive inverse controller is developed for feedback linearizable nonlinear systems with nonsmooth actuator nonlinearities. The use of an actuator nonlinearity inverse and a feedback linearizing controller leads to an error equation suitable for deriving an adaptive update law for the inverse parameters. Closed-loop signal boundedness is proved analytically, and system performance improvement is shown by simulation results. Such adaptive control schemes are also developed for multivariable nonlinear systems with actuator nonlinearities. For nonlinear systems that do not possess a relative degree, dynamic extension is employed to realize adaptive inverse compensation designs for actuator nonlinearities. These adaptive designs ensure closed-loop stability in the presence of uncertain actuator nonlinearities.
Who cares about relative deprivation

Abstract If relative deprivation matters to welfare in poor countries as much as it apparently does in rich ones then one would have to question the priority given to economic growth over redistribution in current development policies. We look for evidence in one of the world's poorest countries, Malawi. Using new survey questions that help address likely biases in past tests, we find that relative deprivation is not the dominant concern for most of our sample, although it is for the comparatively well off, including in urban areas. Our results strengthen the welfarist case for a policy focus on absolute levels of living in poor countries. The pattern of externalities suggests that there will be too much poverty and inequality from the point of view of aggregate efficiency.
Language Support for Reliable Memory Regions

The path to exascale computational capabilities in high-performance computing (HPC) systems is challenged by the inadequacy of present software technologies to adapt to the rapid evolution of architectures of supercomputing systems. The constraints of power have driven system designs to include increasingly heterogeneous architectures and diverse memory technologies and interfaces. Future systems are also expected to experience an increased rate of errors, such that the applications will no longer be able to assume correct behavior of the underlying machine. To enable the scientific community to succeed in scaling their applications, and to harness the capabilities of exascale systems, we need software strategies that enable explicit management of resilience to errors in the system, in addition to locality of reference in the complex memory hierarchies of future HPC systems.
Consumer Risk‐reduction Behavior and New Product Purchases

Consumers purchase lower quantities of new products compared with those they have purchased in the past. We explain this observation as a result of risk‐averting behavior by utility‐maximizing consumers. If a new product involves a higher degree of risk that quality expectations will not be met compared with an incumbent product, we show that utility will be more concave for the new product. We test this prediction using a multiple‐discrete/continuous extreme value (MDCEV) model of demand. We show that utility is indeed more concave for new products relative to previously purchased products. Copyright © 2017 John Wiley & Sons, Ltd.
A Model of Compound Heterozygous, Loss-of-Function Alleles Is Broadly Consistent with Observations from Complex-Disease GWAS Datasets

The genetic component of complex disease risk in humans remains largely unexplained. A corollary is that the allelic spectrum of genetic variants contributing to complex disease risk is unknown. Theoretical models that relate population genetic processes to the maintenance of genetic variation for quantitative traits may suggest profitable avenues for future experimental design. Here we use forward simulation to model a genomic region evolving under a balance between recurrent deleterious mutation and Gaussian stabilizing selection. We consider multiple genetic and demographic models, and several different methods for identifying genomic regions harboring variants associated with complex disease risk. We demonstrate that the model of gene action, relating genotype to phenotype, has a qualitative effect on several relevant aspects of the population genetic architecture of a complex trait. In particular, the genetic model impacts genetic variance component partitioning across the allele frequency spectrum and the power of statistical tests. Models with partial recessivity closely match the minor allele frequency distribution of significant hits from empirical genome-wide association studies without requiring homozygous effect sizes to be small. We highlight a particular gene-based model of incomplete recessivity that is appealing from first principles. Under that model, deleterious mutations in a genomic region partially fail to complement one another. This model of gene-based recessivity predicts the empirically observed inconsistency between twin and SNP based estimated of dominance heritability. Furthermore, this model predicts considerable levels of unexplained variance associated with intralocus epistasis. Our results suggest a need for improved statistical tools for region based genetic association and heritability estimation.
XWIB: an X-Windows interface builder for scientific and engineering application programs

Input to scientific programs (particularly, numerical simulation programs) traditionally requires an in-depth knowledge of complex and interdependent syntactic, semantic, and conceptual information. The effort to acquire this knowledge can deter a novice user from learning a program or cause an expert user to make errors. The XWIB (X-Windows Interface Builder) tool is designed to reduce this cognitive burden by supporting the specification and execution of a graphical user interface oriented toward creating input files for scientific programs.
Drinfeld-Stuhler modules

We study $$\mathscr {D}$$ -elliptic sheaves in terms of their associated modules, which we call Drinfeld–Stuhler modules. First, we prove some basic results about Drinfeld–Stuhler modules and give explicit examples. Then we examine the existence and properties of Drinfeld–Stuhler modules with large endomorphism rings, which are analogous to CM and supersingular Drinfeld modules. Finally, we examine the fields of moduli of Drinfeld–Stuhler modules.
Simulation of Forward Osmosis Flow in a Two-Dimensional Asymmetric Membrane Channel With Draw Channel Circular Baffle Implementation

Forward Osmosis (FO) driven asymmetric membrane filtration is a developing technology which shows promise for seawater desalination and wastewater treatment. Due to the fact that asymmetric membranes are widely used in conjunction with this technology, internal concentration polarization (ICP), a flow-entrainment effect occurring within such membranes, is a significant if not dominant source of overall osmotic pressure loss across the membrane. Accurate modeling of ICP effects is therefore very critical for accurate Computational Fluid Dynamic (CFD) modeling of asymmetric membranes. A related, dilutive effect known as external concentration polarization (ECP) also develops on both the rejection and draw sides of the membrane, further contributing to osmotic pressure loss. In order to increase the overall water flux, circular spacers can be implemented within the draw channel of FO cross-flow membrane exchange units to decrease the effects of ICP and draw ECP. The drawback of spacer inclusions is an increased pressure loss across the length of the feed channel. The system efficiency gained by the decrease in ECP must therefore be weighed against the energy cost of hydraulically making up lost channel pressure. To model the geometry of a FO cross-flow channel, the open source CFD package OpenFOAM is used. A compressible flow model with explicit boundary conditions is developed to simulate the flux transfer and ICP effects present within an asymmetric membrane when exposed to a NaCl solution. Results are validated by comparison with the numerical data generated by earlier models of asymmetric membranes implemented by other investigators using similar simulation conditions.Copyright © 2015 by ASME
Variations of mixed Hodge structure, Higgs fields, and quantum cohomology

Following C. Simpson, we show that every variation of graded-polarized mixed Hodge structure defined over ℚ carries a natural Higgs bundle structure which is invariant under the ℂ* action studied in [20]. We then specialize our construction to the context of [6], and show that the resulting Higgs field θ determines (and is determined by) the Gromov–Witten potential of the underlying family of Calabi–Yau threefolds.
Pseudo CT Estimation from MRI Using Patch-based Random Forest

Recently, MR simulators gain popularity because of unnecessary radiation exposure of CT simulators being used in radiation therapy planning. We propose a method for pseudo CT estimation from MR images based on a patch-based random forest. Patient-specific anatomical features are extracted from the aligned training images and adopted as signatures for each voxel. The most robust and informative features are identified using feature selection to train the random forest. The well-trained random forest is used to predict the pseudo CT of a new patient. This prediction technique was tested with human brain images and the prediction accuracy was assessed using the original CT images. Peak signal-to-noise ratio (PSNR) and feature similarity (FSIM) indexes were used to quantify the differences between the pseudo and original CT images. The experimental results showed the proposed method could accurately generate pseudo CT images from MR images. In summary, we have developed a new pseudo CT prediction method based on patch-based random forest, demonstrated its clinical feasibility, and validated its prediction accuracy. This pseudo CT prediction technique could be a useful tool for MRI-based radiation treatment planning and attenuation correction in a PET/MRI scanner.
Diamond Secondary Emitter

We present the design and experimental progress on the diamond secondary emitter as an electron source for high average power injectors. The design criteria for average currents up to 1 A and charge up to 20 nC are established. Secondary Electron yield (SEY) exceeding 200 in transmission mode and 50 in emission mode have been measured. Preliminary results on the design and fabrication of the self contained capsule with primary electron source and secondary electron emitter will also be presented.
Let Tiebout pick up the tab: Pricing out externalities with free mobility

Free mobility has not been thought of as an effective tool to correct over- or underproduction of externalities. In this paper, we establish that foot voting can internalize the cost of negative externalities. Workers have to accept the wage and rent, however high or low these values are in equilibrium, if they cannot relocate. In reality, workers are mobile and they can effectively influence the equilibrium wage and rent to reflect the externalities by threatening to walk away if the current externalities are at an intolerable level. In an economy with free mobility, firms indirectly pay for the damage in the form of an increased labor or land cost and thus the externalities are partially internalized. We specify the condition under which a mobile economy is efficient in the presence of externalities, and discuss potential policy implications of our findings.
Promoting democracy in fragile states: field experimental evidence from Liberia.

Summary We use a cluster-randomized field experiment to study two strategies to promote free democratic expression among rural voters in Liberia’s 2011 general election. The context is one of a fragile state in which destructive legacies of Liberia’s 1989–2003 civil war continue to dominate people’s lives. A nine-month civic education intervention administered by Liberian civil society organization partners provided training on election procedures and a forum for monthly discussion of governance issues. A nine-month security committee intervention administered in partnership with the United Nations peacekeeping mission in Liberia provided a forum for villagers and international peacekeepers to discuss security threats and develop violence early warning and reaction procedures, with the aim of improving citizens’ perceptions of security during the election. We evaluate these programs’ effects on actual voter behavior in addition to surveyed attitudes. We find that civic education increased enthusiasm for electoral participation, produced a coordinated shift from parochial to national candidates, and increased willingness to report on manipulation. A program combining the two interventions had similar effects. The security committees produced a modest reduction in parochial voting. The policy implications are that third-party actors can play a productive role in helping to overcome barriers to information, voter coordination, and security.
USING FORWARD SOLUTION MODELLING AS AN INTRA-OPERATIVE IMPLANT ASSIST TOOL

Background Currently, hip implant designs are evaluated experimentally using mechanical simulators or cadavers, and total hip arthroplasty (THA) postoperative outcomes are evaluated clinically using long-term follow-up. However, these evaluation techniques can be both costly and time-consuming. Fortunately, forward solution mathematical models can function as theoretical joint simulators, providing instant feedback to designers and surgeons alike. Recently, a validated forward solution model of the hip has been developed that can theoretically simulate new implant designs and surgical technique modifications under in vivo conditions. Objective The objective of this study was to expand the use of this hip model to function as an intraoperative virtual implant tool, thereby allowing surgeons to predict, compare, and optimize postoperative THA outcomes based on component placement, sizing choices, reaming and cutting locations, and surgical methods. Methods The math model simulates the quadriceps muscles, hamstring muscles, gluteus muscles, iliopsoas muscles, tensor fasciae latae, and an adductor muscle group, as well as the ischiofemoral, iliofemoral, and pubofemoral hip capsular ligaments. The model can simulate resecting, weakening, loosening, or tightening of soft tissues based on surgical techniques. Additionally, the model can analyze a variety of activities, both weight-bearing and non-, including swing and stance phase of gait, deep knee bend, and more. The model was previously validated using telemetric implants and fluoroscopic results from existing implant designs. Results First, the model tool has capabilities that will allow surgeons to pre- or intra-operatively experiment with various surgical alignments, component designs, sizes, and offsets, as well as reaming and cutting locations. The model tool will incorporate a built-in CT scan bone database which will assist in determining muscle and ligament attachment sites as well as bony landmarks. The model tool can be used to assist in the placement of both the femoral component (Figure 1) and the acetabular cup (Figure 2). Moreover, once the surgeon has decided on the placements of the components, he or she can use the modelling capabilities of the tool to run virtual simulations based on the chosen parameters. The simulations will reveal force and motion predictions of the hip joint based on the current component positioning (Figure 3). The surgeon can then choose to modify the positions accordingly or proceed with the surgery. Discussion Being able to intraoperatively predict postoperative mechanics will improve the functional outcomes of total hip arthroplasty and reduce the frequency of postoperative complications.
Faster Gaussian Sampling for Trapdoor Lattices with Arbitrary Modulus

We present improved algorithms for gaussian preimage sampling using the lattice trapdoors of (Micciancio and Peikert, CRYPTO 2012). The MP12 work only offered a highly optimized algorithm for the on-line stage of the computation in the special case when the lattice modulus q is a power of two. For arbitrary modulus q, the MP12 preimage sampling procedure resorted to general lattice algorithms with complexity cubic in the bitsize of the modulus (or quadratic, but with substantial preprocessing and storage overheads). Our new preimage sampling algorithm (for any modulus q) achieves linear complexity with very modest storage requirements, and experimentally outperforms the generic method of MP12 already for small values of q. As an additional contribution, we give a new, quasi-linear time algorithm for the off-line perturbation sampling phase of MP12 in the ring setting. Our algorithm is based on a variant of the Fast Fourier Orthogonalization (FFO) algorithm of (Ducas and Prest, ISSAC 2016), but avoids the need to precompute and store the FFO matrix by a careful rearrangement of the operations. All our algorithms are fairly simple, with small hidden constants, and offer a practical alternative to use the MP12 trapdoor lattices in a broad range of cryptographic applications.
Split Probabilities and Species Tree Inference Under the Multispecies Coalescent Model.

Using topological summaries of gene trees as a basis for species tree inference is a promising approach to obtain acceptable speed on genomic-scale datasets, and to avoid some undesirable modeling assumptions. Here we study the probabilities of splits on gene trees under the multispecies coalescent model, and how their features might inform species tree inference. After investigating the behavior of split consensus methods, we investigate split invariants—that is, polynomial relationships between split probabilities. These invariants are then used to show that, even though a split is an unrooted notion, split probabilities retain enough information to identify the rooted species tree topology for trees of 5 or more taxa, with one possible 6-taxon exception.
Does a Crossover Age Effect Exist for African American and Hispanic Binge Drinkers? Findings from the 2010 to 2013 National Study on Drug Use and Health.

BACKGROUND: Among general population studies, lower rates of binge drinking tend to be found among African Americans and Hispanics compared to Whites. However, among older adult populations, minority groups have been shown to be at higher risk for binge drinking, suggesting the presence of a crossover effect from low to high risk as a function of age. To date, limited research has examined the crossover effect among African American and Hispanic populations compared to non-Hispanic Whites across large developmental time frames or explored variation in risk based on income or gender. This study aimed to fill these gaps in the literature. METHODS: Data were compiled from the 2010 to 2013 National Survey on Drug Use and Health surveys, which provide annual, nationally representative data on substance use behaviors among individuals aged 12 and older. Hispanic, non-Hispanic African American, and non-Hispanic White respondents were included (N = 205,198) in the analyses. RESULTS: A crossover effect was found for African American males and females among the lowest income level (i.e., incomes less than $20,000). Specifically, after controlling for education and marital status, compared to Whites, risk for binge drinking was lower for African American males at ages 18 to 24 and for females at ages 18 to 34, but higher for both African American males and females at ages 50 to 64. No crossover effect was found for Hispanic respondents. CONCLUSIONS: Although African Americans are generally at lower risk for binge drinking, risk appears to increase disproportionately with age among those who are impoverished. Explanatory factors, such as social determinants of health prevalent within low-income African American communities (e.g., lower education, violence exposure, housing insecurity) and potential areas for intervention programming are discussed.Copyright © 2017 by the Research Society on Alcoholism. Language: en
How the discovery of ISS-N1 led to the first medical therapy for spinal muscular atrophy

Spinal muscular atrophy (SMA), a prominent genetic disease of infant mortality, is caused by low levels of survival motor neuron (SMN) protein owing to deletions or mutations of the SMN1 gene. SMN2, a nearly identical copy of SMN1 present in humans, cannot compensate for the loss of SMN1 because of predominant skipping of exon 7 during pre-mRNA splicing. With the recent US Food and Drug Administration approval of nusinersen (Spinraza), the potential for correction of SMN2 exon 7 splicing as an SMA therapy has been affirmed. Nusinersen is an antisense oligonucleotide that targets intronic splicing silencer N1 (ISS-N1) discovered in 2004 at the University of Massachusetts Medical School. ISS-N1 has emerged as the model target for testing the therapeutic efficacy of antisense oligonucleotides using different chemistries as well as different mouse models of SMA. Here, we provide a historical account of events that led to the discovery of ISS-N1 and describe the impact of independent validations that raised the profile of ISS-N1 as one of the most potent antisense targets for the treatment of a genetic disease. Recent approval of nusinersen provides a much-needed boost for antisense technology that is just beginning to realize its potential. Beyond treating SMA, the ISS-N1 target offers myriad potentials for perfecting various aspects of the nucleic-acid-based technology for the amelioration of the countless number of pathological conditions.
Genus Two Modular Bootstrap

We study the Virasoro conformal block decomposition of the genus two partition function of a two-dimensional CFT by expanding around a ℤ$_{3}$-invariant Riemann surface that is a three-fold cover of the Riemann sphere branched at four points, and explore constraints from genus two modular invariance and unitarity. In particular, we find “critical surfaces” that constrain the structure constants of a CFT beyond what is accessible via the crossing equation on the sphere.
California’s 2004 Workers’ Compensation Reform: Costs, Claims, and Contingent Workers

The large excess fraction of difficult-to-diagnose injuries that occur on a Monday was originally thought to reflect employees’ use of workers’ compensation to cover weekend injuries. Evidence has ...
Flesch formulas applied to current readings

The Flesch formulas for assessing the readability and human interest of writing were applied to twenty-five articles from five collections of readings in psychology. The articles were found to differ widely: some were readable but lacked human interest; others lacked both; a few were both readable and rich in human interest. Although there has been some improvement in these areas among current readings assigned to beginning college students, the student would still find the majority of the selections difficult and dull.
Dissolved black carbon in the global cryosphere: Concentrations and chemical signatures

Black carbon (BC) is derived from the incomplete combustion of biomass and fossil fuels and can enhance glacial recession when deposited on snow and ice surfaces. Here we explore the influence of environmental conditions and the proximity to anthropogenic sources on the concentration and composition of dissolved black carbon (DBC), as measured by benzenepolycaroxylic acid (BPCA) markers, across snow, lakes, and streams from the global cryosphere. Data are presented from Antarctica, the Arctic, and high alpine regions of the Himalayas, Rockies, Andes, and Alps. DBC concentrations spanned from 0.62 µg/L to 170 µg/L. The median and (2.5, 97.5) quantiles in the pristine samples were 1.8 µg/L (0.62, 12), and non-pristine samples were 21 µg/L (1.6, 170). DBC is susceptible to photodegradation when exposed to solar radiation. This process leads to a less condensed BPCA signature. In general, DBC across the dataset was comprised of less-polycondensed DBC. However, DBC from the Greenland Ice Sheet (GRIS) had a highly-condensed BPCA molecular signature. This could be due to recent deposition of BC from Canadian wildfires. Variation in DBC appears to be driven by a combination of photochemical processing and the source combustion conditions under which the DBC was formed. Overall, DBC was found to persist across the global cryosphere in both pristine and non-pristine snow and surface waters. The high concentration of DBC measured in supra-glacial melt on the GRIS suggests DBC can be mobilized across ice surfaces. This is significant because these processes may jointly exacerbate surface albedo reduction in the cryosphere.
Nonlinear Controller Design for Flight Control Systems

Abstract There has been a great deal of excitement recently over the development of a theory for explicitly linearizing the input-output response of a nonlinear system using state feedback. One shortcoming of this theory is the inability to deal with non-minimum phase nonlinear systems. Highly maneuverable jet aircraft, such as the V/STOL Harrier, belong to an important class of a slightly non-minimum phase nonlinear systems. The non-minimum phase character of these aircraft is clue in part to a slight coupling between rolling moments and lateral accelerations. In this paper, we show that, while straightforward application of the linearization theory to a non-minimum phase system results in a system with a linear input-output response but unstable internal dynamics, designing a feedback control based on a minimum phase approximation to the true system results in a system with desirable properties such as bounded tracking and asymptotic stability.
qSVA framework for RNA quality correction in differential expression analysis

RNA sequencing (RNA-seq) is a powerful approach for measuring gene expression levels in cells and tissues, but it relies on high-quality RNA. We demonstrate here that statistical adjustment using existing quality measures largely fails to remove the effects of RNA degradation when RNA quality associates with the outcome of interest. Using RNA-seq data from molecular degradation experiments of human primary tissues, we introduce a method—quality surrogate variable analysis (qSVA)—as a framework for estimating and removing the confounding effect of RNA quality in differential expression analysis. We show that this approach results in greatly improved replication rates (>3×) across two large independent postmortem human brain studies of schizophrenia and also removes potential RNA quality biases in earlier published work that compared expression levels of different brain regions and other diagnostic groups. Our approach can therefore improve the interpretation of differential expression analysis of transcriptomic data from human tissue.
Cefuroxime, Cefamandole, Cefoxitin, and Cephalothin In Vitro Susceptibility Tests: Reassessment of the"Class Representative" Concept, Confirmation of Disk Interpretive Criteria, and Proposed Quality Control Guidelines

The relationship of cefuroxime in vitro susceptibility tests to similar cephalosporins (cefamandole, cefoxitin, and cephalothin) was evaluated using 396 recent clinical isolates. The previously published interpretive criteria of greater than or equal to 18 mm (less than or equal to 8.0 micrograms/mL) = susceptible and less than or equal to 14 mm (greater than or equal to 32 micrograms/mL) = resistant for each drug were considered appropriate. The results of all study methods demonstrated cefuroxime to be slightly less active than cefamandole against most species, yet both drugs possessed nearly identical antimicrobial spectra. Cephalothin and cefoxitin were confirmed to have spectra significantly different from cefamandole and from each other, thus requiring separate testing. The application of the "class representative" concept to cefuroxime and cefamandole seems justified. Use of a 30-micrograms cefuroxime disk yielded the best predictive results and minimized the number of false-susceptible (very major) interpretive errors. Quality control guidelines are presented in a tentative form for cefuroxime, and modifications in the cephalothin and cefamandole zone limits are suggested.
Fine-Needle Aspiration Effects on Benign Lymph Node Histology

The histology of 28 lymph nodes with benign hyperplasia were assessed for evidence of the effects of fine-needle aspiration prior to biopsy. Only 43% of the lymph nodes showed evidence of prior aspiration. This consisted of needle tracts occupying less than 5% of any one section in ten cases, and 10% in two cases. In none of the 28 lymph nodes did prior fine-needle aspiration interfere with the histologic evaluation. The authors conclude that fine-needle aspiration does not interfere with subsequent histologic evaluation of lymph-adenopathy.
Neonatal Renovascular Hypertension—A Complication of Aortic Monitoring Catheters

Two critically ill neonates with severe removascular hypertension as a complication of aortic monitoring catheter are presented. They did not respond to intensive medical therapy for hypertension. In spite of their precarious general condition, nephrectomy was undertaken with complete relief of symptoms.
Three-Day Antimicrobial Therapy of Urinary Tract Infection

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Experience With the Artificial Urinary Sphincter in Children and Young Adults

The artificial urinary sphincter (model AS 791-792), American Medical Systems, Minnetonka, Minn.) has been implanted in 41 patients (mean age 13.9 years) who were incontinent in spite of intensive efforts with other modes of management. Neurogenic bladder dysfunction is present in 34 patients. Seven patients have non-neuropathic dysfunction of the bladder neck and urethra (3 with exstrophy/epispadias, 3 incontinent after multiple bladder and urethral procedures, and 1 incontinent after a pelvic fracture). Twenty-two patients have had intestino-cystoplasty performed and 11 patients had previous urinary diversion. Mean follow-up for a given device in 23 months (range 6 to 47 months). Of these patients, 80.5% are totally or acceptably dry. Five patients (12.2%) were rated as fair, and three were failures (7.3%). Complications have been significant in that reoperation has been necessary in 16 patients. Indications for patient selection is emphasized.
SOVA: Design of a stakeholder informed social media website for depressed adolescents and their parents

ABSTRACTTwo moderated social media websites were designed for increasing likelihood for mental health treatment engagement for depressed adolescents (sova.pitt.edu) and for parents (wisesova.pitt.edu). This article describes iterative stakeholder interviews conducted with adolescents, young adults, parents, advocates, and clinicians and use of human computer interaction techniques to inform major design changes which: (a) underscored the role of online interaction to provide emotional support and information, (b) importance of anonymity, (c) desire to share positive media, and (d) need for frequent moderation. Future studies will examine acceptability and effectiveness of revised websites in helping depressed adolescents and their parents engage with treatment.
The Uptick in Income Segregation: Real Trend or Random Sampling Variance

Recent studies have reported a reversal of an earlier trend in income segregation in metropolitan regions, from a decline in the 1990s to an increase in the 2000-2010 decade. This finding reinforces concerns about the growing overall income inequality in the U.S. since the 1970s. Yet the evidence may be systematically biased to show an upward trend because the effective sample for the American Community Survey (ACS) is much smaller than it was for Census 2000, to which it is being compared. There is a possibility that the apparent changes in disparities across census tracts result partly from a higher level of sampling variation and bias due to the smaller sample. This study uses 100% microdata from the 1940 census to simulate the impact of different sampling rates on estimates of several measures of segregation and to propose and test the effectiveness of approaches to correcting the bias. It then applies those approaches to publicly available data for 2000 and 2007-2011. The reduction in sample sizes associated with the ACS results in exaggeration of evidence for increasing income segregation for all measures tested here, especially for subgroups (African Americans are studied here as an example). The methods of correction applied here will yield more conclusive and unbiased results when applied to the original sample data that is held internally by the Census Bureau.
DUAL MOBILITY CUP: EMERGENT STANDARD FOR RECURRENT DISLOCATION – OPPOSES

In primary total hip replacements there are numerous options available for providing hip stability in difficult situations (i.e. Down9s syndrome, Parkinson9s disease). We have considered constrained liners in some of these cases. However, in the revision situation in general and in revision for recurrent dislocation situation specifically it is important to have all options available including tripolar constrained liners in order to optimise the potential for hip stability as well as function of the arthroplasty. Even with the newer options available dislocation rates of higher than 10–15% have been reported following revision surgery at institutions where high volumes of revision surgery are performed. Because of the deficient abductors, other soft tissue laxity and the requirement for large diameter cups revision cases will always have more potential for dislocation. In these situations in the lower demand patient, constraint has provided excellent success in terms of preventing dislocation and maintaining implant construct fixation to bone at intermediate- term follow-up. Hence in these situations tripolar constrained liners remains the option we utilise. We are also confident in using this device in cases with instability or laxity where there is a secure well- positioned acetabular shell. We cement a dual mobility constrained liner in these situations using the technique described below. Present indication for tripolar constrained liners: low demand patient, large outer diameter cups, instability with well-fixed shells that are adequately positioned, abductor muscle deficiency or soft tissue laxity, multiple operations for instability Technique of cementing liner into shell: score acetabular shell if no holes, score liner in spider web configuration, all one or two millimeters of cement mantle Results Constrained Dual Mobility Liner For Dislocation: 56 Hips, 10 yr average f/u, 7% failure of device, 5% femoral loosening, 4% acetabular loosening For Difficult Revisions:101 hips, 10 yr average f/u, 6% failure of device, 4% femoral loosening, 4% acetabular loosening Cementing Liner into Shell: 31 hips, 3.6 yr average f/u (2–10 years), 2 of 31 failures
Giving Help to Resisting Patients

The setting of the work described here is the hospital. This discussion has value for our readers because it has applications in principle to situations whose source of concern is blindness, as ill...
Equilibrium Play in Voluntary Ultimatum Games: Beneficence Cannot Be Extorted

Abstract An exceptionally robust result in experimental economics is the failure to observe equilibrium (subgame perfect) play in the ultimatum game. A heretofore unnoticed feature of the game is that neither player voluntarily chooses to play. Motivated by Adam Smith's proposition that beneficence—like that of non-equilibrium play in the ultimatum game—cannot be extorted by force, we offer the responder the opportunity to opt out of the game for a mere $1 payoff for both players. We observe far higher rates of equilibrium play, including highly unequal splits, than heretofore reported in binary choice versions of the game.
GRETA: graph-based real-time event trend aggregation

Streaming applications from algorithmic trading to traffic management deploy Kleene patterns to detect and aggregate arbitrarily-long event sequences, called event trends. State-of-the-art systems process such queries in two steps. Namely, they first construct all trends and then aggregate them. Due to the exponential costs of trend construction, this two-step approach suffers from both a long delays and high memory costs. To overcome these limitations, we propose the Graph-based Real-time Event Trend Aggregation (GRETA) approach that dynamically computes event trend aggregation without first constructing these trends. We define the GRETA graph to compactly encode all trends. Our GRETA runtime incrementally maintains the graph, while dynamically propagating aggregates along its edges. Based on the graph, the final aggregate is incrementally updated and instantaneously returned at the end of each query window. Our GRETA runtime represents a win-win solution, reducing both the time complexity from exponential to quadratic and the space complexity from exponential to linear in the number of events. Our experiments demonstrate that GRETA achieves up to four orders of magnitude speed-up and up to 50--fold memory reduction compared to the state-of-the-art two-step approaches.