cssi/SciSciGPT-SciSciNet huggingface dataset:
RESPONSE OF LIQUID JET TO MODULATED CROSSFLOW

Experimental results on the response of spray formed by the liquid (Jet-A) jet injection into a crossflow (Air) is presented with a special emphasis on its response to the modulating crossflow. The pressure of the chamber is up to 3.5 atm and the corresponding Weber number is up to 510. The spray of a liquid jet for steady and oscillating crossflow is characterized. The flow field at the injector location in the crossflow direction is determined using PIV (Particle Image Velocimetry) for oscillating as well as steady crossflow case. Planar Mie-scattering measurement is used to characterize the response of spray formed under oscillating crossflow and supplementary phase-averaged PDPA measurements are used to understand the response behavior. The global response of spray to the oscillating crossflow is characterized using the planar Mie-scattering imaging. It shows that there exist very little differences in the heights of the maximum-pixel intensity trajectory for the non-oscillating and oscillating crossflow conditions and the trajectory under oscillating crossflow is lower than that of steady crossflow, suggesting the oscillating crossflow affects the atomization (i.e. the oscillating crossflow enhances atomization process, results in smaller droplets and penetrates less transversely). The response of spray to the oscillating crossflow characterized in terms of the spray transfer function (STF) shows that the gain of the STF increases linearly (at least monotonically) as the liquid-air momentum flux ratio increases but does not change as much with respect to the change of the Weber number for a fixed liquid-air momentum flux ratio. This also indicates that the liquid jet atomization under oscillating crossflow is enhanced much more with the increase of liquid-air momentum flux ratio than with the increase of Weber number. The phase-averaged PDPA measurements confirm that the oscillating crossflow indeed enhances the atomization process in that the oscillating crossflow results in relatively greater number of smaller droplets and the mean droplet size.Copyright © 2013 by ASME
Elements of the Theory of Computation

From the Publisher: Lewis and Papadimitriou present this long awaited Second Edition of their best-selling theory of computation. The authors are well-known for their clear presentation that makes the material accessible to a a broad audience and requires no special previous mathematical experience. In this new edition, the authors incorporate a somewhat more informal, friendly writing style to present both classical and contemporary theories of computation. Algorithms, complexity analysis, and algorithmic ideas are introduced informally in Chapter 1, and are pursued throughout the book. Each section is followed by problems.
Has the time come for preprints in biology

Preprints, non-peer-reviewed drafts of manuscripts available on the Internet, have been used in conjunction with peer review and publication in journals in the physical sciences for almost 25 years. Recently, more scientists have been discussing whether preprints can play a similar role in biological and biomedical research. Here, I discuss my excitement and concerns about the role that preprints can play in disseminating research findings in the life sciences.
Should patients with optic neuritis be treated with steroids

Purpose of reviewOptic neuritis is the most common cause of optic neuropathy in young adults. High-dose intravenous corticosteroids (IVCS) were established as the standard of treatment for acute optic neuritis via the Optic Neuritis Treatment Trial (ONTT), with its first findings published more than
Advanced Laser Architecture for Two-Step Laser Tandem Mass Spectrometer

Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. We have made significant progress in the laser desorption/ionization mass spectrometry area with advancement in the two-step laser tandem mass spectrometer (L2MS) instrument to deconvolve complex organic signatures. In this paper we will describe our development effort on a new laser architecture for the L2MS instrument. The laser provides two discrete mid-infrared and ultraviolet wavelengths on a single laser bench with a straightforward path toward space deployment.
Multi-channel entanglement distribution using spatial multiplexing from four-wave mixing in atomic vapor

Four-wave mixing in atomic vapor allows for the generation of multi-spatial-mode states of light containing many pairs of two-mode entangled vacuum beams. This in principle can be used to send independent secure keys to multiple parties simultaneously using a single light source. In our experiment, we demonstrate this spatial multiplexing of information by selecting three independent pairs of entangled modes and performing continuous-variable measurements to verify the correlations between entangled partners. In this way, we generate three independent pairs of correlated random bit streams that could be used as secure keys. We then demonstrate a classical four-party secret sharing scheme as an example for how this spatially multiplexed source could be used.
AdS-Carroll branes

Coset methods are used to determine the action of a co-dimension one brane (domain wall) embedded in (d + 1)-dimensional AdS space in the Carroll limit in which the speed of light goes to zero. The action is invariant under the non-linearly realized symmetries of the AdS-Carroll spacetime. The Nambu-Goldstone field exhibits a static spatial distribution for the brane with a time varying momentum density related to the brane’s spatial shape as well as the AdS-C geometry. The AdS-C vector field dual theory is obtained.
Searching For A Single Community in a Graph

In standard graph clustering/community detection, one is interested in partitioning the graph into more densely connected subsets of nodes. In contrast, the search problem of this paper aims to only find the nodes in a single such community, the target, out of the many communities that may exist. To do so , we are given suitable side information about the target; for example, a very small number of nodes from the target are labeled as such. We consider a general yet simple notion of side information: all nodes are assumed to have random weights, with nodes in the target having higher weights on average. Given these weights and the graph, we develop a variant of the method of moments that identifies nodes in the target more reliably, and with lower computation, than generic community detection methods that do not use side information and partition the entire graph.
Traffic-sensitive Live Migration of Virtual Machines

Abstract In this paper we address the problem of network contention between the migration traffic and the Virtual Machine (VM) application traffic for the live migration of co-located Virtual Machines. When VMs are migrated with pre-copy, they run at the source host during the migration. Therefore the VM applications with predominantly outbound traffic contend with the outgoing migration traffic at the source host. Similarly, during post-copy migration, the VMs run at the destination host. Therefore the VM applications with predominantly inbound traffic contend with the incoming migration traffic at the destination host. Such contention increases the total migration time of the VMs and degrades the performance of the VM application. Here, we propose a traffic-sensitive live VM migration technique to reduce the contention of migration traffic with the VM application traffic. It uses a combination of pre-copy and post-copy techniques for the migration of the co-located VMs (those located on the same source host), instead of relying on any single pre-determined technique for the migration of all the VMs. We base the selection of migration techniques on the VMs’ network traffic profiles so that the direction of migration traffic complements the direction of the most VM application traffic. We have implemented a prototype of traffic-sensitive migration on the KVM/QEMU platform. In the evaluation, we compare traffic-sensitive migration against the approaches that use only pre-copy or only post-copy for VM migration. We show that our approach minimizes the network contention for migration, thus reducing the total migration time and the application degradation.
Gene- and genome-based analysis of significant codon patterns in yeast, rat and mice genomes with the CUT Codon UTilization tool.

The translation of mRNA in all forms of life uses a three-nucleotide codon and aminoacyl-tRNAs to synthesize a protein. There are 64 possible codons in the genetic code, with codons for the ∼20 amino acids and 3 stop codons having 1- to 6-fold degeneracy. Recent studies have shown that families of stress response transcripts, termed modification tunable transcripts (MoTTs), use distinct codon biases that match specifically modified tRNAs to regulate their translation during a stress. Similarly, translational reprogramming of the UGA stop codon to generate selenoproteins or to perform programmed translational read-through (PTR) that results in a longer protein, requires distinct codon bias (i.e., more than one stop codon) and, in the case of selenoproteins, a specifically modified tRNA. In an effort to identify transcripts that have codon usage patterns that could be subject to translational control mechanisms, we have used existing genome and transcript data to develop the gene-specific Codon UTilization (CUT) tool and database, which details all 1-, 2-, 3-, 4- and 5-codon combinations for all genes or transcripts in yeast (Saccharomyces cerevisiae), mice (Mus musculus) and rats (Rattus norvegicus). Here, we describe the use of the CUT tool and database to characterize significant codon usage patterns in specific genes and groups of genes. In yeast, we demonstrate how the CUT database can be used to identify genes that have runs of specific codons (e.g., AGA, GAA, AAG) linked to translational regulation by tRNA methyltransferase 9 (Trm9). We further demonstrate how groups of genes can be analyzed to find significant dicodon patterns, with the 80 Gcn4-regulated transcripts significantly (P < 0.00001) over-represented with the AGA-GAA dicodon. We have also used the CUT database to identify mouse and rat transcripts with internal UGA codons, with the surprising finding of 45 and 120 such transcripts, respectively, which is much larger than expected. The UGA data suggest that there could be many more translationally reprogrammed transcripts than currently reported. CUT thus represents a multi-species codon-counting database that can be used with mRNA-, translation- and proteomics-based results to better understand and model translational control mechanisms.
Selective Crystal Growth and Structural, Optical, and Electronic Studies of Mn3Ta2O8

Mn3Ta2O8, a stable targeted material with an unusual and complex cation topology in the complicated Mn–Ta–O phase space, has been grown as a ≈3-cm-long single crystal via the optical floating-zone technique. Single-crystal absorbance studies determine the band gap as 1.89 eV, which agrees with the value obtained from density functional theory electronic-band-structure calculations. The valence band consists of the hybridized Mn d–O p states, whereas the bottom of the conduction band is formed by the Ta d states. Furthermore, out of the three crystallographically distinct Mn atoms that are four-, seven-, or eight-coordinate, only the former two contribute their states near the top of the valence band and hence govern the electronic transitions across the band gap.
Does socioeconomic status predict outcomes after cholecystectomy

Abstract Background This study was performed to evaluate the effect of socioeconomic status (SES) on outcomes after cholecystectomy. METHODS The National Inpatient Sample (NIS) database (2005 to 2011) was queried for patients undergoing cholecystectomy. Clinically relevant variables were used to examine clinical characteristics, postoperative complications, and mortality. SES was investigated by examining income quartile. Results More than 2 million patients underwent cholecystectomy during this period. They were divided into quartiles by SES. The lowest cohort was younger (50 years, P P P P Conclusions Patients with Medicaid and lower SES had poorer outcomes after cholecystectomy.
Active avoidance behavior in the F1 progeny of male rats exposed to cyclophosphamide prior to fertilization

The acquisition and extinction of a one-way active avoidance task was studied in 30 day old F1 progeny of male rats previously exposed to either acute or chronic treatment with cyclophosphamide (CP) prior to breeding with normal females. Chronic treatment (10 mg/kg/day x 5 days x 5 weeks) was given to adult F344 males followed by subsequent breeding with normal females (CP-S). Separate groups of males were given a single CP injection (10 mg/kg) and breeding with normal females was done at 7-9, 14-16 and 28-30 days following the CP treatment. F1 progeny of males exposed to chronic CP or to a single CP treatment when bred 7-9 (females only) and 14-16 days post exposure (males and females) took significantly longer to reach the criterion for extinction. These progeny also responded significantly faster during extinction than progeny of the saline treated males. These findings support our earlier evidence of behavioral anomalies induced in the F1 progeny of male rats exposed to CP prior to breeding and that this effect reflects damage in post-meiotic germ cells.
Phylogenetic incongruence and the evolutionary origins of cardenolide‐resistant forms of Na+,K+‐ATPase in Danaus butterflies

Many distantly related insect species are specialized feeders of cardenolide-containing host plants such as milkweed (Asclepias spp.). Previous studies have revealed frequent, parallel substitution of a functionally important amino acid substitution (N122H) in the alpha subunit of Na(+) ,K(+) -ATPase in a number of these species. This substitution facilitates the ability of these insects to feed on their toxic hosts and sequester cardenolides for their own use in defense. Among milkweed butterflies of the genus Danaus, the previously established phylogeny for this group suggests that N122H arose independently and fixed in two distinct lineages. We reevaluate this conclusion by examining Danaus phylogenetic relationships using >400 orthologous gene sequences assembled from transcriptome data. Our results indicate that the three Danaus species known to harbor the N122H substitution are more closely related than previously thought, consistent with a single, common origin for N122H. However, we also find evidence of both incomplete lineage sorting and post-speciation genetic exchange among these butterfly species, raising the possibility of collateral evolution of cardenolide-insensitivity in this species group.
Financial Statements as Monitoring Mechanisms: Evidence from Small Commercial Loans

Using a data set that records banks’ ongoing requests of information from small commercial borrowers, we examine when banks use financial statements to monitor borrowers after loan origination. We find that banks request financial statements for half the loans and this variation is related to borrower credit risk, relationship length, collateral, and the provision of business tax returns, but in complex ways. The relation between borrower risk and financial statement requests has an inverted U-shape; and tax returns can be both substitutes and complements to financial statements, conditional on borrower characteristics and the degree of bank–borrower information asymmetry. Frequent financial reporting is used to monitor collateral, but only for non–real estate loans and only when the collateral is easily accessible to lenders. Collectively, our results provide novel evidence of a fundamental information demand for financial reporting in monitoring small commercial borrowers and a specific channel through which banks fulfill their role as delegated monitors.
Bone Quality and Quantity are Mediated by Mechanical Stimuli

Prevention of fracture through improved bone mechanical strength is of great importance given the large number of bone disease-related fractures each year, the decreased quality of life associated with fractures, and the large anticipated increase in fracture incidence over the upcoming years due to the aging population. Exercise and other forms of mechanical stimulation have been shown to increase bone mass, suggesting improved strength. However, while bone mass is a good indicator of strength, other components (such as bone quality) also contribute to bone mechanical integrity. While increased bone mass has been explored considerably using both exercise and targeted loading models, the role of mechanical stimulation in altering bone quality has been explored to a lesser degree. Understanding how to improve both the quantity and quality of bone is critical to increasing fracture resistance. Herein, we discuss quantity and quality-based improvements that have been observed using both exercise and targeted loading models of bone adaptation.
Heavy Charged-Particle Stereotactic Radiosurgery: Cerebral Angiography and CT in the Treatment of Intracranial Vascular Malformations

A method is described for stereotactic localization of intracranial arteriovenous malformations (AVM) and for calculating treatment plans for heavy charged-particle Bragg peak radiosurgery. A stereotactic frame and head immobilization system is used to correlate the images of multivessel cerebral angiography and computed tomography. The AVM is imaged by angiography, and the frame provides the stereotactic coordinates for transfer of this target to CT images for the calculation of treatment plans. The CT data are used to calculate the residual ranges and compensation for the charged-particle beam required for each treatment port. Three-dimensional coordinates for the patient positioner are calculated, and stereotactic radiosurgery is performed. Verification of the accuracy of the stereotactic postitioning is obtained with computer-generated overlays of the vascular malformation, stereotactic fiducial markers, and bony landmarks on orthogonal radiographs immediately prior to treatment. Using these procedures, the accuracy of the repositioning of the patient at each of a series of imaging and treatment procedures is typically within 1 mm in each of three orthogonal planes.
The Nef Reaction

The Nef reaction is usually defined as the conversion of a primary or secondary nitroalkane into the corresponding carbonyl compound. This reaction was reported by the Swiss chemist J. U. Nef in 1894. Hydrochloric and sulfuric acid give the same result. The conversion of a nitro group to a carbonyl group has become an important synthetic tool because of the ease of preparation of substituted nitro compounds by condensation of nitroalkanes with aldehydes (the Henry reaction), conjugate addition of nitroalkanes to electrophilic alkenes, or carbon alkylation of the dianion of primary nitroparaffins. The Nef reaction is one of the better examples of “umpolung” reactivity in which the original nitro compound anion functions as an acyl anion equivalent. This chapter discusses the Nef reaction and modifications of the original process that extend the variety of compounds which are useful as substrates. Each modification is considered according to general mechanistic type and is organized in a “reagent” approach. The Tabular Survey lists all known examples of both the Nef reaction and these modifications so that specific comparison of methods can be made. Keywords: Nef reaction; scope; limitations; oxidizing agents; reducing agents; nitro compounds; alkylation; acylation; nitroolfins; nitroepoxides; experimental procedures; nitronates; side reactions; synthetic utility
Synthesis of Linear (Z)-α,β-Unsaturated Esters by Catalytic Cross-Metathesis. The Influence of Acetonitrile.

Kinetically controlled catalytic cross-metathesis reactions that generate (Z)-α,β-unsaturated esters selectively are disclosed. A key finding is that the presence of acetonitrile obviates the need for using excess amounts of a more valuable terminal alkene substrates. On the basis of X-ray structure and spectroscopic investigations a rationale for the positive impact of acetonitrile is provided. Transformations leading to various E,Z-dienoates are highly Z-selective as well. Utility is highlighted by application to stereoselective synthesis of the C1–C12 fragment of biologically active natural product (−)-laulimalide.
Sparse Channel Estimation for Massive MIMO with 1-Bit Feedback Per Dimension

In massive multiple-input multiple-output (MIMO) systems, acquisition of the channel state information at the transmitter side (CSIT) is crucial. In this paper, a practical CSIT estimation scheme is proposed for frequency division duplexing (FDD) massive MIMO systems. Specifically, each received pilot symbol is first quantized to one bit per dimension at the receiver side and then the quantized bits are fed back to the transmitter. A joint one-bit compressed sensing algorithm is implemented at the transmitter to recover the channel matrices. The algorithm leverages the hidden joint sparsity structure in the user channel matrices to minimize the training and feedback overhead, which is considered to be a major challenge for FDD systems. Moreover, the one-bit compressed sensing algorithm accurately recovers the channel directions for beamforming. The one-bit feedback mechanism can be implemented in practical systems using the uplink control channel. Simulation results show that the proposed scheme nearly achieves the maximum output signal-to-noise-ratio for beamforming based on the estimated CSIT.
General solutions of equations of some geophysical importance

General solutions are obtained in rectangular, circular cylindrical, and spherical coordinates for the equations of motion of a homogeneous isotropic elastic body (in § 2), the equations of the corresponding statical deformations (§ 3), the equations of motion of an incompressible viscous fluid (§ 4), the equations of the corresponding stationary motion (§ 5), and Maxwell's equations for a homogeneous isotropic conductor (§ 6).
Pooled Analysis of Aids-Malignancy Consortium (AMC) Trials Evaluating Rituximab Plus Either CHOP or Infusional EPOCH Chemotherapy In HIV-Associated Non-Hodgkin's Lymphoma

Abstract 1797 Background: Two consecutively performed randomized studies by the AMC evaluating chemoimmunotherapy for the treatment of HIV-associated NHL include AMC010 (Kaplan LD et al, Blood 2005: concurrent Rituximab [R] + CHOP vs. CHOP, N=150) and AMC034 (Sparano JA et al, Blood 2010: concurrent R+EPOCH vs. Sequential EPOCH → R; N=106). In AMC010, the addition of Rituximab to CHOP was associated with an increased risk of infectious death (15% vs. 2%, p=0.04) without a significant improvement in complete response (CR) rate (58% vs.47%; p=0.15), event free survival (EFS), or overall survival (OS). In AMC034, the CR rate met its primary efficacy endpoint in the concurrent arm (73%; 95% confidence intervals [CI] 58%, 85%) but not the sequential arm (55%; 95% CI 41%, 68%). Methods: We performed a pooled analysis of these two consecutive trials including patients treated with R-CHOP and concurrent R-EPOCH in order to determine the influence of the age-adjusted International Prognostic Index (aaIPI), CD4 count ( Results: The characteristics and outcomes of the study populations are shown in table 1. Patients treated with R-EPOCH tended to have better outcomes in both the low and high risk IPI groups. In a multivariate analysis that included pooled data from both consecutive studies, features that were significantly associated with improved EFS, OS, and CR rate included low aaIPI score and baseline CD4 count of at least 100/ul. Additionally patients treated with concurrent R-EPOCH exhibited improved EFS and OS even when adjusted for prognostic covariates including aaIPI score and CD4 count (table 2). Conclusions: These findings suggest that treatment outcomes may be superior with concurrent R-EPOCH compared with R-CHOP, and support the design of an ongoing phase III trial comparing concurrent R-EPOCH with R-CHOP in immunocompetent patients with diffuse, large B-cell lymphoma (NCT00118209). This analysis provides additional level 2 evidence supporting the use of concurrent R-EPOCH in patients with HIV-associated lymphoma. Acknowledgements: This study is presented on behalf of the AIDS Malignancy Consortium. Disclosures: No relevant conflicts of interest to declare.
Auto Credit and the 2005 Bankruptcy Reform: The Impact of Eliminating Cramdowns

Auto lenders were perhaps the biggest winners of the 2005 Bankruptcy Reform. Cars depreciate quickly, so borrowers often owe more than their car is worth. Prior to the Reform, these borrowers could reduce the principal on their auto loan to the market value of the car through a ?cramdown? in Chapter 13 bankruptcy. The Reform prohibited cramdowns during the first two and a half years of an auto loan. This paper is the first to estimate the causal effect of this anticramdown provision on the price and quantity of auto credit. The authors use a novel empirical strategy that relies on the fact that eliminating cramdowns affected only one of the two types of consumer bankruptcy: Chapter 13. They exploit persistent historical variation in states? usage of Chapter 13 generated by differences in local legal culture. Using difference-in-differences regressions, their empirical strategy compares pre-Reform and post-Reform auto loans across states with persistent historical differences in the share of bankruptcies filed under Chapter 13. They find that eliminating cramdowns decreased interest rates on auto loans in the average state by 15 basis points, with a larger decline in states where Chapter 13 is more common. The decline in interest rates occurs in the exact month that the Reform went into effect, and the authors rule out other aspects of the Reform as possible causes. Next, the authors estimate the effect on the quantity of auto credit. Using quarterly data from the FRBNY Consumer Credit Panel based on Equifax credit reports, they examine the effect of eliminating cramdowns on the number and size of new auto loans. The estimates show a small, negative, and insignificant impact on the number of new auto loans. The authors do find some evidence, however, that loan sizes increased among subprime borrowers.
New dualities and misleading anomaly matchings from outer-automorphism twists

We study four-dimensional $$ \mathcal{N}=1,\ 2 $$ superconformal theories in class $$ \mathcal{S} $$ obtained by compactifying the 6d $$ \mathcal{N}=\left(2,\ 0\right) $$ theory on a Riemann surface $$ \mathcal{C} $$ with outer-automorphism twist lines. From the pair-of-pants decompositions of $$ \mathcal{C} $$ , we find various dual descriptions for the same theory having distinct gauge groups. We show that the various configurations of the twist line give rise to dual descriptions for the identical theory. We compute the ’t Hooft anomaly coefficients and the superconformal indices to test dualities. Surprisingly, we find that the class $$ \mathcal{S} $$ theories with twist lines wrapping 1-cycles of $$ \mathcal{C} $$ have the identical ’t Hooft anomalies as the ones without the twist line, whereas the superconformal indices differ. This provides a large set of examples where the anomaly matching is insufficient to test dualities.
Divide and Inform: Rationing Information to Facilitate Persuasion

ABSTRACT: This paper develops a Bayesian persuasion model that examines a manager's incentives to gather information when the manager can disseminate this information selectively to interested parties (“users”) and when the objectives of the manager and the users are not perfectly aligned. The model predicts that if the manager can choose the subset of users to receive the information, then the manager may gather more precise information. The paper identifies conditions under which a regime that allows managers to grant access to information selectively maximizes aggregate information. Strikingly, this happens when the objectives of managers and users are sufficiently misaligned. This finding is robust to variations of the model, such as information acquisition cost, unobservable precision, sequential noisy actions taken by the users, and delayed choice of the subset of users in “the know.” These results call into doubt the common belief that forcing managers to provide unrestricted access to information ...
Elasticity of Demand and Optimal Prize Distribution for Instant Lottery Games

This study explores the optimal payout structure and prize distribution of instant (scratch-off) lottery games. Using ticket sales data for 185 instant lottery games sold between 2007 and 2011 by the Maryland State Lottery and Gaming Control Agency, we calculate the price elasticity of demand across a range of ticket denominations. Our findings suggest that increasing the payout rate of instant tickets will increase revenue, particularly among low denomination tickets. We also find that reallocating the current prize distributions within a game towards fewer, but more valuable, low-tier prizes will increase the number of tickets sold.
Computing area in presentations of the trivial group

We give polynomial-time dynamic-programming algorithms finding the areas of words in the presentations $\langle a, b \mid a, b \rangle$ and $\langle a, b \mid a^k, b^k; \ k \in \mathbb{N} \rangle$ of the trivial group. In the first of these two cases, area was studied under the name spelling length by Majumdar, Robbins and Zyskin in the context of the design of liquid crystals. We explain how the problem of calculating it can be reinterpreted in terms of RNA-folding. In the second, area is what Jiang called width and studied when counting fixed points for self-maps of a compact surface, considered up to homotopy. In 1991 Grigorchuk and Kurchanov gave an algorithm computing width and asked whether it could be improved to polynomial time. We answer this affirmatively.
Information-theoretical noninvasive damage detection in bridge structures.

Damage detection of mechanical structures such as bridges is an important research problem in civil engineering. Using spatially distributed sensor time series data collected from a recent experiment on a local bridge in Upper State New York, we study noninvasive damage detection using information-theoretical methods. Several findings are in order. First, the time series data, which represent accelerations measured at the sensors, more closely follow Laplace distribution than normal distribution, allowing us to develop parameter estimators for various information-theoretic measures such as entropy and mutual information. Second, as damage is introduced by the removal of bolts of the first diaphragm connection, the interaction between spatially nearby sensors as measured by mutual information becomes weaker, suggesting that the bridge is “loosened.” Finally, using a proposed optimal mutual information interaction procedure to prune away indirect interactions, we found that the primary direction of interact...
Mesoscale simulations of particulate flows with parallel distributed Lagrange multiplier technique

Fluid particulate flows are common phenomena in nature and industry. Modeling of such flows at micro and macro levels as well establishing relationships between these approaches are needed to understand properties of the particulate matter. We propose a computational technique based on the direct numerical simulation of the particulate flows. The numerical method is based on the distributed Lagrange multiplier technique following the ideas of Glowinski et al. [16] and Patankar [30]. Each particle is explicitly resolved on an Eulerian grid as a separate domain, using solid volume fractions. The fluid equations are solved through the entire computational domain, however, Lagrange multiplier constrains are applied inside the particle domain such that the fluid within any volume associated with a solid particle moves as an incompressible rigid body. Mutual forces for the fluid-particle interactions are internal to the system. Particles interact with the fluid via fluid dynamic equations, resulting in implicit fluid-rigid body coupling relations that produce realistic fluid flow around the particles (i.e., no-slip boundary conditions). The particle-particle interactions are implemented using explicit force-displacement interactions for frictional inelastic particles similar to the DEM method of Cundall et al. [10] with some modifications using a volume of an overlapping region as an input to the contact forces. The method is flexible enough to handle arbitrary particle shapes and size distributions. A parallel implementation of the method is based on the SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure) library, which allows handling of large amounts of rigid particles and enables local grid refinement. Accuracy and convergence of the presented method has been tested against known solutions for a falling particle as well as by examining fluid flows through stationary particle beds (periodic and cubic packing). To evaluate code performance and validate particle contact physics algorithm, we performed simulations of a representative experiment conducted at the U.C. Berkeley Thermal Hydraulic Lab for pebble flow through a narrow opening.
When distributed computation is communication expensive

We consider a number of fundamental statistical and graph problems in the message-passing model, where we have $$k$$ machines (sites), each holding a piece of data, and the machines want to jointly solve a problem defined on the union of the $$k$$ data sets. The communication is point-to-point, and the goal is to minimize the total communication among the $$k$$ machines. This model captures all point-to-point distributed computational models with respect to minimizing communication costs. Our analysis shows that exact computation of many statistical and graph problems in this distributed setting requires a prohibitively large amount of communication, and often one cannot improve upon the communication of the simple protocol in which all machines send their data to a centralized server. Thus, in order to obtain protocols that are communication-efficient, one has to allow approximation, or investigate the distribution or layout of the data sets.
TWO-YEAR OUTCOMES OF CEMENTLESS TOTAL KNEE ARTHROPLASTY UTILISING A TRABECULAR METAL TIBIAL BASEPLATE

INTRODUCTION Total knee arthroplasty (TKA) is typically performed using cement to secure the prosthesis to bone. There are complications associated with cementing that include intra-operative hypotension, third-body abrasive wear, and loosening at the cement interfaces. A cementless prosthesis using a novel keeled trabecular metal tibial baseplate was developed to eliminate the need for cementing the tibial component in TKA. METHODS A retrospective chart review was performed on patients who underwent TKA using cementless tibial and femoral components between August, 2013 and January, 2014. Patients with minimum two-year follow-up including radiographs were included in the analysis. Patient demographics as well as preoperative and postoperative range of motion (ROM) and function were measured using the Knee Society Scoring system (KSS). Post-operative radiographs were assessed for signs of osteolysis, loosening, or subsidence. Paired T-tests were used to identify differences in preoperative and postoperative ROM and KSS. RESULTS Thirty-three patients underwent 48 TKAs in the study period. Of those, 20 patients (29 knees) completed two-year follow-up. The mean patient age was 69.0 ±8.4 years and mean BMI was 29.9 ±4.3. The average time of follow-up was 24.6 months (range 24–29). Preoperative ROM was on average 4.3–117.3°±6.7 and the preoperative KSS knee scores and functional scores were 43.8 ±8.6 and 49.8 ±12.6, respectively. Postoperatively, there were statistically significant improvements in ROM (0–130.7°±7.3), and postoperative KSS knee (98.4 ±3.2) and functional scores (99.3 ±2.6), at two years, respectively. None of the radiographs demonstrated evidence of osteolysis, loosening, migration, or subsidence. DISCUSSION and CONCLUSION The two-year results of TKA utilizing a cementless tibial baseplate demonstrate excellent results in terms of knee ROM and function. The radiographic evidence of osteointegration without evidence of loosening, subsidence, or migration of the tibial components is promising. Further follow up is necessary to ensure that these implants will provide a satisfactory long-term alternative to cement fixation.
A usability study of the obamacare website: Evaluation and recommendations

Abstract We conducted a usability study of the healthcare.gov website, popularly known as the Obamacare website, using the guidelines available on usability.gov , which were published by the Department of Health and Human Services. The study was conducted among 374 citizens. We found that the interface design, which we conceptualized as 16 dimensions, was rated rather low. Specifically, five dimensions of usability emerged as key to the prediction of overall usability of the website: hardware and software, home page, screen, scrolling and paging, and user experience. We also found that citizen satisfaction and intention to use the website were rated poorly. Based on a break down by gender, age and voting behavior (for Obama or not), we found several interesting patterns of differences. Ultimately, even if the infrastructure issues that have received a bulk of the media attention are miraculously resolved, our findings suggest that the site will be found wanting. The article offers specific illustrative examples of usability problems with the website and specific recommendations drawn from usability.gov . In addition to the practical implications for Obamacare, the article offers significant implications for researchers who seek to evaluate the usability of websites in general and healthcare websites in particular.
The octonions as a twisted group algebra

Abstract We show that the octonions can be defined as the R -algebra with basis { e x : x ∈ F 8 } and multiplication given by e x e y = ( − 1 ) φ ( x , y ) e x + y , where φ ( x , y ) = tr ( y x 6 ) . While it is well known that the octonions can be described as a twisted group algebra, our purpose is to point out that this is a useful description. We show how the basic properties of the octonions follow easily from our definition. We give a uniform description of the sixteen orders of integral octonions containing the Gravesian integers, and a computation-free proof of their existence.
Cohomology and Support Varieties for Lie Superalgebras of Type W(n)

Boe, Kujawa and Nakano [3; 4] recently investigated relative cohomology for classical Lie superalgebras and developed a theory of support varieties. The dimensions of these support varieties give a geometric interpretation of the combinatorial notions of defect and atypicality due to Kac, Wakimoto, and Serganova. In this paper, we calculate the cohomology ring of the Cartan-type Lie superalgebra W(n) relative to the degree zero component W(n) 0 and show that this ring is a finitely generated polynomial ring. This allows one to define support varieties for finite-dimensional W(n)-supermodules, which are completely reducible over W(n) 0 . We calculate the support varieties of all simple supermodules in this category. The outcome of our computations naturally divides the simple supermodules into two families. Remarkably, this partition coincides with the one based on Serganova's prior notion of atypicality for Cartan-type superalgebras. In this way the support variety construction gives a geometric interpretation of atypicality. We also present new results on the realizability of support varieties, which hold for both classical and Cartan-type superalgebras.
Separating Semantic and Circular Security for Symmetric-Key Bit Encryption from the Learning with Errors Assumption

In this work we separate private-key semantic security from 1-circular security for bit encryption using the Learning with Error assumption. Prior works used the less standard assumptions of multilinear maps or indistinguishability obfuscation. To achieve our results we develop new techniques for obliviously evaluating branching programs.
Dynamic average consensus under limited control authority and privacy requirements

arXiv:1401.6463v1 [math.OC] 24 Jan 2014 Dynamic Average Consensus under Limited Control Authority and Privacy Requirements ∗ Solmaz S. Kia, Jorge Cort´es, Sonia Mart´inez Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093, USA Abstract This paper introduces a novel continuous-time dynamic average consensus algorithm for networks whose interaction is described by a strongly connected and weight-balanced directed graph. The proposed distributed algorithm allows agents to track the average of their dynamic inputs with some steady-state error whose size can be controlled using a design parameter. This steady-state error vanishes for special classes of input signals. We analyze the asymptotic correctness of the algorithm under time-varying interaction topologies and characterize the requirements on the stepsize for discrete-time implementations. We show that our algorithm naturally preserves the privacy of the local input of each agent. Building on this analysis, we synthesize an extension of the algorithm that allows individual agents to control their own rate of convergence towards agreement and handle saturation bounds on the driving command. Finally, we show that the proposed extension additionally preserves the privacy of the transient response of the agreement states and the final agreement value from internal and external adversaries. Numerical examples illustrate the results. Keywords: dynamic average consensus; time-varying input signals; directed graphs; rate of con- ∗ under review in International Journal of Robust and Nonlinear Control
Global existence of null-form wave equations in exterior domains

We provide a proof of global existence of solutions to quasilinear wave equations satisfying the null condition in certain exterior domains. In particular, our proof does not require estimation of the fundamental solution for the free wave equation. We instead rely upon a class of Keel–Smith–Sogge estimates for the perturbed wave equation. Using this, a notable simplification is made as compared to previous works concerning wave equations in exterior domains: one no longer needs to distinguish the scaling vector field from the other admissible vector fields.
Fluidized Bed Steam Reformed (FBSR) Mineral Waste Forms: Characterization and Durability Testing

Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of high sodium low activity wastes (LAW) such as those existing at the Hanford site, at the Idaho National Laboratory (INL), and the Savannah River Site (SRS). The addition of clay, charcoal, and a catalyst as co-reactants with the waste denitrates the aqueous wastes and forms a granular mineral waste form that can subsequently be made into a monolith for disposal if necessary. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage and ring structures and iron bearing spinel minerals. The mineralization occurs at moderate temperatures between 650-750°C in the presence of superheated steam. The cage and ring structured feldspathoid minerals atomically bond radionuclides like Tc-99 and Cs-137 and anions such as SO4, I, F, and Cl. The spinel minerals stabilize Resource Conservation and Recovery Act (RCRA) hazardous species such as Cr and Ni. Granular mineral waste forms were made from (1) a basic Hanford Envelope A low-activity waste (LAW) simulant and (2) an acidic INL simulant commonly referred to as sodium-bearing waste (SBW) in pilot scale facilities at the Science Applications International Corporation (SAIC) Science and Technology Applications Research (STAR) facility in Idaho Falls, ID. The FBSR waste forms were characterized and the durability tested via ASTM C1285 (Product Consistency Test), the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP), and the Single Pass Flow Through (SPFT) test. The results of the SPFT testing and the activation energies for dissolution are discussed in this study.
Whole Genome Sequences of the Raspberry and Strawberry Pathogens Phytophthora rubi and P. fragariae

Phytophthora rubi and P. fragariae are two closely related oomycete plant pathogens that exhibit strong morphological and physiological similarities but are specialized to infect different hosts of economic importance, namely, raspberry and strawberry. Here, we report the draft genome sequences of these two Phytophthora species as a first step toward understanding the genomic processes underlying plant host adaptation in these pathogens.
The Strategic Potential of Community-Based Hybrid Models: The Case of Global Business Services in Africa

Research Summary Firms in latecomer economies, such as Sub-Saharan Africa, often have limited success with traditional business models. We explain why it can be more feasible to adopt a hybrid model in such a region that combines profitability with serving local communities, e.g., by promoting inclusive employment or by targeting underserved markets. Sub-Saharan Africa supports hybrid models and social enterprises mainly through local community resources (e.g., labor, market ideas), community organizations giving access to such resources, and experience with business-community alliances. Hybrid models can benefit from such conditions when business clients and governments support the social mission and when firms are ready to target niche rather than mainstream markets. We illustrate the business potential of hybrid enterprises based on the case of ‘impact sourcing’ in global business services in Kenya and South Africa. Managerial summary As a latecomer economy, Africa faces persistent difficulties with catching up in global markets. This study examines the strategic potential of community-based hybrid models, which balance market profitability with social impact in local communities. Focusing on the global business services industry in Kenya and South Africa and the practice of ‘impact sourcing’ (the hiring and training of disadvantaged staff servicing business clients), we find that while regular providers struggle to compete with global peers, hybrid model adopters manage to access underutilized labor pools through community organizations, and target less competitive niche client markets. We further identify key industry-, institutional-, and firm-level factors that affect hybrid model adoption. Findings have important implications for research on catch-up processes in latecomer economies, hybrid models, and global business services. Copyright © 2016 John Wiley & Sons, Ltd.
Femtosecond mega-electron-volt electron microdiffraction.

Abstract To understand and control the basic functions of physical, chemical and biological processes from micron to nano-meter scale, an instrument capable of visualizing transient structural changes of inhomogeneous materials with atomic spatial and temporal resolutions, is required. One such technique is femtosecond electron microdiffraction, in which a short electron pulse with femtosecond-scale duration is focused into a micron-scale spot and used to obtain diffraction images to resolve ultrafast structural dynamics over a localized crystalline domain. In this letter, we report the experimental demonstration of time-resolved mega-electron-volt electron microdiffraction which achieves a 5 μm root-mean-square (rms) beam size on the sample and a 110 fs rms temporal resolution. Using pulses of 10k electrons at 4.2 MeV energy with a normalized emittance 3 nm-rad, we obtained high quality diffraction from a single 10 μm paraffin ( C 44 H 90 ) crystal. The phonon softening mode in optical-pumped polycrystalline Bi was also time-resolved, demonstrating the temporal resolution limits of the instrument. This new characterization capability will open many research opportunities in material and biological sciences.