cssi/SciSciGPT-SciSciNet huggingface dataset:
Tight Space-Approximation Tradeoff for the Multi-Pass Streaming Set Cover Problem

We study the classic set cover problem in the streaming model: the sets that comprise the instance are revealed one by one in a stream and the goal is to solve the problem by making one or few passes over the stream while maintaining a sublinear space o(mn) in the input size; here m denotes the number of the sets and n is the universe size. Notice that in this model, we are mainly concerned with the space requirement of the algorithms and hence do not restrict their computation time.Our main result is a resolution of the space-approximation tradeoff for the streaming set cover problem: we show that any α-approximation algorithm for the set cover problem requires Ω(mn1/α) space, even if it is allowed polylog(n) passes over the stream, and even if the sets are arriving in a random order in the stream. This space-approximation tradeoff matches the best known bounds achieved by the recent algorithm of Har-Peled et.al. (PODS 2016) that requires only O(α) passes over the stream in an adversarial order, hence settling the space complexity of approximating the set cover problem in data streams in a quite robust manner. Additionally, our approach yields tight lower bounds for the space complexity of (1- e)-approximating the streaming maximum coverage problem studied in several recent works.
Tritium Room Air Monitor Operating Experience Review

Monitoring the breathing air in tritium facility rooms for airborne tritium is a radiological safety requirement and a best practice for personnel safety. Besides audible alarms for room evacuation, these monitors often send signals for process shutdown, ventilation isolation, and cleanup system actuation to mitigate releases and prevent tritium spread to the environment. Therefore, these monitors are important not only to personnel safety but also to public safety and environmental protection. This paper presents an operating experience review of tritium monitor performance on demand during small (1 mCi to 1 Ci) operational releases, and intentional airborne in-room tritium release tests. The tritium tests provide monitor operation data to allow calculation of a statistical estimate for the reliability of monitors annunciating in actual tritium gas airborne release situations. The data show a failure to operate rate of 3.5E-06/monitor-hr with an upper bound of 4.7E-06, a failure to alarm on demand rate of 1.4E-02/demand with an upper bound of 4.4E-02, and a spurious alarm rate of 0.1 to 0.2/monitor-yr.
DRUG MISUSE IN TOTAL KNEE ARTHROPLASTY REVISION INCIDENCE IN THE MEDICARE PATIENT POPULATION

Background Substance abuse and dependence is thought to have a strongly negative impact on surgical outcomes. The purpose of this study was to determine the effects of drug misuse on total knee arthroplasty (TKA) revision incidence, revision causes, and time to revision by analyzing the Medicare database between 2005–2012. Methods A retrospective review of the Medicare database within the PearlDiver Supercomputer (Warsaw, IN) for TKA and revisions was performed utilizing Current Procedural Terminology (CPT) and International Classification of Disease (ICD) ninth revision codes. Drug misuse was subdivided into cocaine, cannabis, opioids, sedative/hypnotic/anxiolytic, amphetamines, and alcohol. Time to revision, age, and gender were also investigated. Results Our query returned 2159221 TKAs and 193024 (8.9%) revisions between 2005–2012. Drug misuse was prevalent in 173513 (8%). Cocaine had the highest revision incidence (13.9%). Cannabis had the fastest average (636.1 days) and median (457 days) time to revision. At 30 and 90 days, cannabis had the greatest rate of revision at 6% and 12% respectively. At 6 months and 1 year, amphetamine had the greatest revision risk at 25% and 40.5% respectively. Infection was the most common cause of revision among all substances. Conclusion Cocaine misuse holds the highest risk for revision. However cannabis misuse is more likely to require revision sooner, particularly at the 30 and 90 day intervals. Infection was the most common cause of revision regardless of substance misused. Thus it is important to obtain a detailed social history on drug misuse and to be vigilant for postoperative infections in these patients.
MINIMISING INFECTION RISK: A PERI-OPERATIVE CHECKLIST

Infection following primary total knee arthroplasty (TKA) is fortunately a relatively uncommon complication with an incidence of approximately 1%. However, because the morbidity and cost of treatment of deep prosthetic TKA infections is so high, effective prevention strategies are key quality improvement initiatives. The cause of post-operative infections are multifactorial and complex but can generally be categorised into 1) host, 2) surgical, and 3) environmental factors. The purpose of this abstract to provide an outline of these factors and their influences on the infection risk following TKA. Patient factors and optimization of modifiable risk factors have been shown to decrease the risk for infection. While the individual contributions of factors such as body mass index (BMI), diabetes, nutritional status, Charlson Comorbidity Index (CCI), and renal disease are unknown, together, they have been shown to influence infection risk. Additionally, Tayton et al. analyzed 64,566 primary TKAs in the New Zealand Joint Registry and found that male gender and prior knee surgery were also independent risk factors of development of PJI 12 months following TKA. Finally, Crowe and colleagues also identified tobacco use and Staphylococcus aureus colonization as modifiable risk factors for minimizing PJI following primary TKA. Timely administration of prophylactic antibiotics prior and after surgery has been shown to be the most effective strategy to reduce infection risk. The optimal prophylaxis regimen for all patients is unknown and in certain situations, administration of Vancomycin in additional to a conventional cephalosporin may be beneficial. However, universal administration of Vancomycin has not been shown to decrease the incidence of surgical site infections and could actually increase the risk for renal failure. Conversely, addition of antibiotics to cement during primary TKA has not been shown to reduce long term infection risk. The use of dilute betadine lavage has been shown by some authors to be beneficial. Finally, good surgical technique, proper soft tissue handling, and meticulous wound closure are all critical factors influencing the risk for infectious complications following TKA. Environmental factors have also been shown to affect infection rates following TKA. While the use of laminar flow and body exhaust suits have not been shown to significantly influence the risk for infection, minimizing operating room traffic has been shown effective in reducing the risk for contamination. Some authors have shown ultraviolet light systems to decrease airborne contaminants. In summary, factors influencing infection risk following TKA are complex and multifactorial. Patient selection, optimization of modifiable risk factors, appropriate use of antibiotics, and minimization of OR traffic are among the most common strategies to minimizing infection.
SilkMoth: an efficient method for finding related sets with maximum matching constraints

Determining if two sets are related - that is, if they have similar values or if one set contains the other -- is an important problem with many applications in data cleaning, data integration, and information retrieval. For example, set relatedness can be a useful tool to discover whether columns from two different databases are joinable; if enough of the values in the columns match, it may make sense to join them. A common metric is to measure the relatedness of two sets by treating the elements as vertices of a bipartite graph and calculating the score of the maximum matching pairing between elements. Compared to other metrics which require exact matchings between elements, this metric uses a similarity function to compare elements between the two sets, making it robust to small dissimilarities in elements and more useful for real-world, dirty data. Unfortunately, the metric suffers from expensive computational cost, taking O(n3) time, where n is the number of elements in the sets, for each set-to-set comparison. Thus for applications that try to search for all pairings of related sets in a brute-force manner, the runtime becomes unacceptably large.To address this challenge, we developed SilkMoth, a system capable of rapidly discovering related set pairs in collections of sets. Internally, SilkMoth creates a signature for each set, with the property that any other set which is related must match the signature. SilkMoth then uses these signatures to prune the search space, so only sets that match the signatures are left as candidates. Finally, SilkMoth applies the maximum matching metric on remaining candidates to verify which of these candidates are truly related sets. An important property of SilkMoth is that it is guaranteed to output exactly the same related set pairings as the brute-force method, unlike approximate techniques. Thus, a contribution of this paper is the characterization of the space of signatures which enable this property. We show that selecting the optimal signature in this space is NP-complete, and based on insights from the characterization of the space, we propose two novel filters which help to prune the candidates further before verification. In addition, we introduce a simple optimization to the calculation of the maximum matching metric itself based on the triangle inequality. Compared to related approaches, SilkMoth is much more general, handling a larger space of similarity functions and relatedness metrics, and is an order of magnitude more efficient on real datasets.
Estimating the spectral gap of a trace-class Markov operator

The utility of a Markov chain Monte Carlo algorithm is, in large part, determined by the size of the spectral gap of the corresponding Markov operator. However, calculating (and even approximating) the spectral gaps of practical Monte Carlo Markov chains in statistics has proven to be an extremely difficult and often insurmountable task, especially when these chains move on continuous state spaces. In this paper, a method for accurate estimation of the spectral gap is developed for general state space Markov chains whose operators are non-negative and trace-class. The method is based on the fact that the second largest eigenvalue (and hence the spectral gap) of such operators can be bounded above and below by simple functions of the power sums of the eigenvalues. These power sums often have nice integral representations. A classical Monte Carlo method is proposed to estimate these integrals, and a simple sufficient condition for finite variance is provided. This leads to asymptotically valid confidence intervals for the second largest eigenvalue (and the spectral gap) of the Markov operator. In contrast with previously existing techniques, our method is not based on a near-stationary version of the Markov chain, which, paradoxically, cannot be obtained in a principled manner without bounds on the spectral gap. On the other hand, it can be quite expensive from a computational standpoint. The efficiency of the method is studied both theoretically and empirically.
On combining graph-based variance reduction schemes

In this paper, we consider two variance reduction schemes that exploit the structure of the primal graph of the graphical model: Rao-Blackwellised w-cutset sampling and AND/OR sampling. We show that the two schemes are orthogonal and can be combined to further reduce the variance. Our combination yields a new family of estimators which trade time and space with variance. We demonstrate experimentally that the new estimators are superior, often yielding an order of magnitude improvement over previous schemes on several benchmarks.
Help or hindrance? U.S. aid on growth

We distinguish between U.S. aid and non-U.S. aid and study the effects on growth in recipient countries. Our analysis exploits time variation in aid due to changes in the supply of U.S. aid and cro...
Nuclear decay data : the statement of uncertainties

At the annual general meeting of the International Committee for Radionuclide Metrology (ICRM) held last June at the Physikalisch-Technische Bundesanstalt, it was suggested that letters should be sent to the editors of journals that publish nucleardecay data, drawing attention to the need for specific statements of the uncertainties that are associated with such data. Authors frequently fail to state clearly the nature of their estimates of uncertainty, and not all editors insist on such clarity, so that evaluators of nuclear-decay data often f'md that it is necessary to consult with the individual authors to arrive at the weighting factors appropriate to their data. If uncertainties could be dearly characterized in the abstracts or in the text of papers reporthag values of nuclear parameters, there would be a corresponding shortening of the time required for the data to be evaluated and tabulated. There are many methods of stating estimates of conventional random and systematic uncertainties that are acceptable, provided that the methods used are described. Thus random error may be stated as: (i) the estimate of the standard deviation (or the square root of the variance), which is in the same units as the observed data and indicates the order of magnitude of the spread of the data: (ii) the standard error (or the estimated standard deviation of the mean of the distribution); and (ri) the estimated limits for the mean at stated levels of confidence (C1) (e.g. limits at the 99-percent CI define the range within which there is a 99:percent probability of ineluding the mean of a population). Provided that the author states the number of independent measurements made of the given parameter, or the number of degrees of freedom, these statements of random uncertainty are related uniquely to each other. The other component of the overall uncertainty is the estimate of possible systematic error. The significance, or meaning, of the estimate of systematic uncertainties should be dearly stated and also related to the method chosen to state the random uncertainties. Thus an estimate of maximum conceivable systematic uncertainties would logically be combined with a random uncertainty at a 99-percent confidence level. An appropriate fraction of the estimate of maximum conceivable systematic uncertainty would be chose to match smaller random confidence levels. The methods used to combine random and systematic uncertainties should also be stated by authors, and an explicit listing of all components of these uncertainties will allow an evaluator of nuclear data to "unravel" the statements of uncertainty and to choose
Reductions in interface defects, Dit, by post oxidation plasma-assisted nitridation of GaN–SiO2 interfaces in MOS devices

Abstract This paper applies remote plasma processing techniques, remote plasma assisted oxidation (nitridation) RPAO(N) and RP enhanced chemical vapor deposition (RPECVD), developed originally for fabrication of Si MOS devices with deposited SiO2, Si3N4 and Si oxynitride alloys to the formation of device-quality GaN MOS devices. Significant improvements in device performance for GaN–SiO2 interfaces are demonstrated by following an RPAO process step that forms the device interface with an interface nitridation RPAN step prior to the deposition of an SiO2 dielectric film by RPECVD. On-line Auger electron spectroscopy is used to monitor interface bonding for different ordering of RPAO and RPAN process steps.
Evidence of carrier localization in InAsSb/InSb digital alloy nBn detector

Recently we have demonstrated a novel method of extending the cut-off wavelength of InAsSb nBn detectors, by incorporating a series of monolayers of InSb. Here we study photoluminescence and minority carrier lifetime of this InAsSb/InSb digital alloy. While increasing temperature from 15 K to 40 K we show a 14 meV blue shift of the photoluminescence peak energy and a decrease in lifetime. This deviation from the expected Varshni empirical relation indicates strong carrier localization. We contrast to photoluminescence and lifetime results in bulk InAsSb. We discuss implications of this localization for design of digital alloy InAsSb/InSb nBn detectors.
The leverage effect and the basket-index put spread

Abstract Benchmark models that exogenously specify equity dynamics cannot explain the large spread in prices between put options written on individual banks and options written on the bank index during the financial crisis. However, theory requires that asset dynamics be specified exogenously and that endogenously determined equity dynamics exhibit a “leverage effect” that increases put prices by fattening the left tail of the distribution. The leverage effect is larger for puts on individual stocks than for puts on the index, thus increasing the basket-index spread. Time-series and cross-sectional variation in the leverage effect explains option prices well.
Cigarette smoking is associated with amplified age-related volume loss in subcortical brain regions

Abstract Background Magnetic resonance imaging studies of cigarette smoking-related effects on human brain structure have primarily employed voxel-based morphometry, and the most consistently reported finding was smaller volumes or lower density in anterior frontal regions and the insula. Much less is known about the effects of smoking on subcortical regions. We compared smokers and non-smokers on regional subcortical volumes, and predicted that smokers demonstrate greater age-related volume loss across subcortical regions than non-smokers. Methods Non-smokers (n = 43) and smokers (n = 40), 22–70 years of age, completed a 4 T MRI study. Bilateral total subcortical lobar white matter (WM) and subcortical nuclei volumes were quantitated via FreeSurfer. In smokers, associations between smoking severity measures and subcortical volumes were examined. Results Smokers demonstrated greater age-related volume loss than non-smokers in the bilateral subcortical lobar WM, thalamus, and cerebellar cortex, as well as in the corpus callosum and subdivisions. In smokers, higher pack-years were associated with smaller volumes of the bilateral amygdala, nucleus accumbens, total corpus callosum and subcortical WM. Conclusions Results provide novel evidence that chronic smoking in adults is associated with accelerated age-related volume loss in subcortical WM and GM nuclei. Greater cigarette quantity/exposure was related to smaller volumes in regions that also showed greater age-related volume loss in smokers. Findings suggest smoking adversely affected the structural integrity of subcortical brain regions with increasing age and exposure. The greater age-related volume loss in smokers may have implications for cortical-subcortical structural and/or functional connectivity, and response to available smoking cessation interventions.
Bayesian Fused Lasso Regression for Dynamic Binary Networks

ABSTRACTWe propose a multinomial logistic regression model for link prediction in a time series of directed binary networks. To account for the dynamic nature of the data, we employ a dynamic model for the model parameters that is strongly connected with the fused lasso penalty. In addition to promoting sparseness, this prior allows us to explore the presence of change points in the structure of the network. We introduce fast computational algorithms for estimation and prediction using both optimization and Bayesian approaches. The performance of the model is illustrated using simulated data and data from a financial trading network in the NYMEX natural gas futures market. Supplementary material containing the trading network dataset and code to implement the algorithms is available online.
Methods to Expand Cell Signaling Models Using Automated Reading and Model Checking

Biomedical research results are being published at a high rate, and with existing search engines, the vast amount of published work is usually easily accessible. However, reproducing published results, either experimental data or observations is often not viable. In this work, we propose a framework to overcome some of the issues of reproducing previous research, and to ensure re-usability of published information. We present here a framework that utilizes the results from state-of-the-art biomedical literature mining, biological system modeling and analysis techniques, and provides means to scientists to assemble and reason about information from voluminous, fragmented and sometimes inconsistent literature. The overall process of automated reading, assembly and reasoning can speed up discoveries from the order of decades to the order of hours or days. Our framework described here allows for rapidly conducting thousands of in silico experiments that are designed as part of this process.
Measurement-free implementations of small-scale surface codes for quantum-dot qubits

The performance of quantum-error-correction schemes depends sensitively on the physical realizations of the qubits and the implementations of various operations. For example, in quantum-dot spin qubits, readout is typically much slower than gate operations, and conventional surface-code implementations that rely heavily on syndrome measurements could therefore be challenging. However, fast and accurate reset of quantum-dot qubits, without readout, can be achieved via tunneling to a reservoir. Here we propose small-scale surface-code implementations for which syndrome measurements are replaced by a combination of Toffoli gates and qubit reset. For quantum-dot qubits, this enables much faster error correction than measurement-based schemes, but requires additional ancilla qubits and non-nearest-neighbor interactions. We have performed numerical simulations of two different coding schemes, obtaining error thresholds on the orders of ${10}^{\ensuremath{-}2}$ for a one-dimensional architecture that only corrects bit-flip errors and ${10}^{\ensuremath{-}4}$ for a two-dimensional architecture that corrects bit- and phase-flip errors.
International risk cycles

Abstract Recent work in international finance suggests that exchange rate puzzles can be accounted for if (1) aggregate uncertainty is time-varying, and (2) countries have heterogeneous exposures to a world aggregate shock. We embed these features in a standard two-country real business cycle framework, and calibrate the model to equity risk premia in low and high interest rates countries. Unlike traditional real business cycle models, our model generates volatile exchange rates, a large currency forward premium, “excess comovement” of asset prices relative to quantities, and an imperfect correlation between relative consumption growth and exchange rates. Our model implies, however, that high interest rate countries have smoother quantities, equity returns and interest rates than low interest rate countries, contrary to the data.
What is the Incidence of Varicocele in a Fertile Population

The incidence of subclinical and clinical varicocele or reflux of blood into the internal spermatic vein in the fertile population was estimated at 61% by examining 100 consecutive men who presented for vasectomy. The men averaged 36 years old (range 28-52) and 2.5 children 67% of them having fathered a child less than 3 years old. Varicocele was determined by palpation with a pencil probe held over the spermatic cord in the region of the pampiniform plexus while the patient was standing and performing the Valsalva maneuver. The Doppler stethoscope was also used. A definite prolonged bruit was considered a positive subclinical varicocele. A clinical left varicocele was seen in 17 men (17%) and a subclinical varicocele in 44 (44%); left in all but 1 and bilateral in 8 men. Reports in the literature range from 8-23% for clinically evident varicoceles. Apparently subclinical varicocele has no detrimental effect on fertility.
Cis-Diamminedichloroplatinum (II) in Locally Advanced and Metastatic Urothelial Cancer

Twenty-seven consecutive patients with locally extensive or metastatic urothelial cancer, primarily bladder, were given cis-diamminedichloroplatinum (II) (DDP) at a dose of 70 mg/m2 every three weeks. All patients had hydration and mannitol-induced diuresis initiated before administration of DDP. Nine patients (33%) had a partial response; 12 (45%) remained stable for an average duration of six months. Responders had a significantly greater survival than nonresponders. Although severe nephrotoxicity did not occur, patients with either a solitary or obstructed kidney were at greater risk of an increase in the serum creatinine during therapy.
Relaxed Path Tracking of Mechanical Manipulators by Parameter Estimation

Abstract To eliminate the burden of computing the dynamics while controlling the mechanical manipulator, its dynamic behavior is modeled by a difference equation. Quadratic terms representing centrifugal forces are included in the equation to reduce modeling errors. The parameters of the model are estimated based on the minimum variance criterion. The control torque for each joint is computed during each sampling period to minimize the deviation from points on the desired joint path. Desired joint path could be obtained from the Cartesian path using spline function approximations.
Improved Patient and Primary Renal Allograft Survival in Uremic Diabetic Recipients

From January 1968 to December 1981, 470 uremic diabetic patients received primary renal allografts at the University of Minnesota. Until 1979, the patient and graft survival rates were less good in diabetic than in nondiabetic recipients. Since 1979, the results in diabetics have been at least equal to those achieved in nondiabetic patients. Two-year actuarial patient and graft survival rates in diabetic renal allograft recipients were, respectively, 71 and 66% from 1968 to 1976 (n = 156), 78 and 64% from 1976 to 1979 (n = 187), and 88 and 82% from 1979 to 1981 (n = 127). Improved survival rates were seen in all donor source and recipient age categories. For comparison, the 2-year patient and graft survival rates in nondiabetic renal allograft recipients who received transplants between 1979 and 1981 (n = 162) were 92 and 79%. Changes associated with improved survival rates included performance of pretransplant splenectomy on all patients except those receiving grafts from HLA-identical siblings, deliberate transfusions of blood from greater than or equal to 5 random donors at least 1 month before transplantation, intensive insulin therapy for diabetic management post-transplant, and less vigorous treatment of repetitive rejection episodes. The current results show that diabetic recipients are no longer at higher risk than nondiabetics for graft or patient loss, at least during the first 2 years after transplantation.
In vitro synergy of ampicillin and chloramphenicol against gram-negative bacteria

The activity of ampicillin and chloramphenicol in combination was evaluated against 16 gram-negative bacterial isolates from the cerebrospinal fluid of neonates with meningitis. The combination of antibiotics was synergistic (fractional inhibitory concentration less than 1.0) against 11 of 16 (69%) isolates by agar dilution technique and 12 of 16 (75%) isolates by microbroth dilution technique. In kinetic studies, ampicillin and chloramphenicol together exhibited an increased rate of killing against 9 of 14 isolates. Antagonistic activity between ampicillin and chloramphenicol was not demonstrated in any of the studies. The clinical evaluation of ampicillin and chloramphenicol together in the treatment of gram-negative neonatal meningitis deserves further study.
Neuroblastoma: The Case for Screening Infants in North America

Neuroblastoma is a disease in which easily measured tumor markers are excreted. It is curable when diagnosed in an early stage and at an early age, and it has a high incidence relative to other serious childhood diseases. Recent advances in screening infants for neuroblastoma by detection of urinary homovanillic acid and vanillylmandelic acid, the most useful markers of neuroblastoma, are described. Based on results from Japan's mass-screening program and on the authors' observations, it is estimated that mass screening for neuroblastoma could save 260 lives annually in the United States.
APPSSAT: Approximate probabilistic planning using stochastic satisfiability

We describe appssat, an anytime probabilistic contingent planner based on zander, a probabilistic contingent planner that operates by converting the planning problem to a stochastic satisfiability (Ssat) problem and solving that problem instead [S.M. Majercik, M.L. Littman, Contingent planning under uncertainty via stochastic satisfiability, Artificial Intelligence 147 (2003) 119-162]. The values of some of the variables in an Ssat instance are probabilistically determined; appssat considers the most likely instantiations of these variables (the most probable situations facing the agent) and attempts to construct an approximation of the optimal plan that succeeds under those circumstances, improving that plan as time permits. Given more time, less likely instantiations/situations are considered and the plan is revised as necessary. In some cases, a plan constructed to address a relatively low percentage of possible situations will succeed for situations not explicitly considered as well, and may return an optimal or near-optimal plan. We describe experimental results showing that appssat can find suboptimal plans in cases in which zander is unable to find the optimal (or any) plan. Although the test problems are small, the anytime quality of appssat means that it has the potential to efficiently derive suboptimal plans in larger, time-critical domains in which zander might not have sufficient time to calculate any plan. We also suggest further work needed to bring appssat closer to attacking real-world problems.
Noninvasive Characterization of Renal Artery Blood Flow

Noninvasive characterization of renal artery blood flow variables in the human has not been reported. Using a unique dual-frequency real-time two-dimensional echo Doppler (Duplex scanner) that was calibrated in vitro, we characterized renal artery blood flow patterns in 16 normal subjects (6 females). Calculated mean values of systolic diameter (Ds), maximal spatial average blood velocity (Vmsa), and volume flow rate (Q) were as follows: 4.5 +/- 0.6 mm right, 4.4 +/- 0.6 mm left; 67.6 +/- 9.4 cm . sec-1 right, 69.6 +/- 12.0 cm . sec-1 left; and 403 +/- 127 ml . min-1 right, 395 +/- 98 ml . min-1 left; respectively. Direct linear regression correlation of body surface area (BSA) with Ds and Q were statistically significant (P less than 0.01, r = 0.70; and P less than 0.01, r = 0.72, respectively). In a blind prospective series, six of seven angiographically normal renal arteries were noninvasively identified by normal geometry and blood velocity patterns. One angiographically normal artery was incorrectly classified as mildly stenotic. Eleven angiographically documented abnormal renal arteries were noninvasively identified by their abnormal blood flow patterns and/or geometry. This study suggests that dual-frequency Duplex scanning with careful sample volume control and Doppler audio spectra/blood velocity waveform analysis can be used to characterize blood flow variables in normal and diseased human renal arteries.
The Origin of Animal Multicellularity and Cell Differentiation

Over 600 million years ago, animals evolved from a unicellular or colonial organism whose cell(s) captured bacteria with a collar complex, a flagellum surrounded by a microvillar collar. Using principles from evolutionary cell biology, we reason that the transition to multicellularity required modification of pre-existing mechanisms for extracellular matrix synthesis and cytokinesis. We discuss two hypotheses for the origin of animal cell types: division of labor from ancient plurifunctional cells and conversion of temporally alternating phenotypes into spatially juxtaposed cell types. Mechanistic studies in diverse animals and their relatives promise to deepen our understanding of animal origins and cell biology.
Summary of Propagation Cases of the Second AIAA Sonic Boom Prediction Workshop

A summary is provided for the propagation portion of the second AIAA Sonic Boom Prediction Workshop, held 8 January 2017 in conjunction with the AIAA SciTech 2017 Conference. Near-field pressure wa...
The dogs of war: A Bronze Age initiation ritual in the Russian steppes

Abstract At the Srubnaya-culture settlement of Krasnosamarskoe in the Russian steppes, dated 1900–1700 BCE, a ritual occurred in which the participants consumed sacrificed dogs, primarily, and a few wolves, violating normal food practices found at other sites, during the winter. At least 64 winter-killed canids, 19% MNI/37% NISP, were roasted, fileted, and apparently were eaten. More than 99% were dogs. Their heads were chopped into small standardized segments with practiced blows of an axe on multiple occasions throughout the occupation. Two adult men and two adult women from the nearby cemetery, possibly two generations of resident ritual specialists, showed unusual skeletal pathologies and post-mortem treatments. The repeated violation of the canid-eating taboo, unique to this site, combined with the metaphor of human transformation into male canids, suggests that the participants entered a liminal state typical of a rite of passage. Parallels from comparative Indo-European (IE) mythology provide the indigenous narrative that gave meaning to this ritual: we argue that it was an initiation into the widely attested IE institution of the youthful male war-band, symbolized by transformation into a dog or wolf.
A case of hidden genocide? Disintegration and destruction of people of color in Napoleonic Europe, 1799–1815

ABSTRACTMigration, social mobility, and integration of new populations in late eighteenth-century Europe resulted in an expansion of diversity, which contributed to abolition and culminated in full civil rights between 1791 and 1799. This revolutionary experiment in equality faced both domestic and multinational opposition, which led to the genocidal purge of diversity in Europe and the wider world during the Napoleonic Era.
Market equilibrium under piecewise Leontief concave utilities

Abstract Leontief is one of the most widely used and extensively studied function in economic modeling, for both production and preferences. However it lacks the desirable property of diminishing returns. In this paper, we consider piecewise Leontief concave (p-Leontief) utility function which consists of a set of Leontief-type segments with decreasing returns and an upper limit on the utility on each segment, and study complexity of computing equilibria in both Fisher and exchange market models. Leontief is a special case of p-Leontief with exactly one segment with no upper limit. While it is well known that equilibrium computation in Fisher markets with Leontief utilities is polynomial time, in case of p-Leontief, even with two segments, we show that the problem is PPAD-hard. On the other hand for the case when coefficients across segments are scaled versions of each other, we give a polynomial time algorithm. As a corollary, we obtain a non-trivial new class of exchange markets with Leontief utilities where an equilibrium can be computed in a polynomial time, whereas the general problem is known to be PPAD-hard. For p-Leontief exchange markets with pairing economy we show that equilibria are rational and we obtain a simplex-like algorithm to compute one using the classic Lemke–Howson scheme, thereby extending the results of Ye, TCS 2007, and Codenotti, Saberi, Varadarajan and Ye, SODA 2006 for Leontief to p-Leontief utilities.
Real Exchange Rates, Dollarization and Industrial Employment in Latin America

We use a panel dataset on industrial employment and trade for 9 Latin American countries for which liability dollarization data at the industrial level is available. We test whether real exchange rate fluctuations have a significant impact on employment, and analyze whether the impact varies with the degree of trade openness and liability dollarization. Econometric evidence supports the view that real exchange rate depreciations can impact employment growth positively, but this effect is reversed as liability dollarization increases. In industries with high liability dollarization, the overall impact of a real exchange rate depreciation can be negative.
Strain localization and elastic-plastic coupling during deformation of porous sandstone

Abstract Results of axisymmetric compression tests on weak, porous Castlegate Sandstone (Cretaceous, Utah, USA), covering a range of dilational and compactional behaviors, are examined for localization behavior. Assuming isotropy, bulk and shear moduli evolve as increasing functions of mean stress and Mises equivalent shear stress respectively, and as decreasing functions of work-conjugate plastic strains. Acoustic emissions events located during testing show onset of localization and permit calculation of observed shear and low-angle compaction localization zones, or bands, as localization commences. Total strain measured experimentally partitions into: A) elastic strain with constant moduli, B) elastic strain due to stress dependence of moduli, C) elastic strain due to moduli degradation with increasing plastic strain, and D) plastic strain. The third term is the elastic-plastic coupling strain, and though often ignored, contributes significantly to pre-failure total strain for brittle and transitional tests. Constitutive parameters and localization predictions derived from experiments are compared to theoretical predictions. In the brittle regime, predictions of band angles (angle between band normal and maximum compression) demonstrate good agreement with observed shear band angles. Compaction localization was observed in the transitional regime in between shear localization and spatially pervasive compaction, over a small range of mean stresses. In contrast with predictions, detailed acoustic emissions analyses in this regime show low angle, compaction-dominated but shear-enhanced, localization.
Healthy Business? Managerial Education and Management in Healthcare

We investigate the link between hospital performance and managerial education by collecting a large database of management practices and skills in hospitals across nine countries. We find that hosp...
Lexico-Minimum Replica Placement in Multitrees

In this work, we consider the problem of placing replicas in a data center or storage area network, represented as a digraph, so as to lexico-minimize a previously proposed reliability measure which minimizes the impact of all failure events in the model in decreasing order of severity. Prior work focuses on the special case in which the digraph is an arborescence. In this work, we consider the broader class of multitrees: digraphs in which the subgraph induced by vertices reachable from a fixed node forms a tree. We parameterize multitrees by their number of “roots” (nodes with in-degree zero), and rule out membership in the class of fixed-parameter tractable problems (FPT) by showing that finding optimal replica placements in multitrees with 3 roots is NP-hard. On the positive side, we show that the problem of finding optimal replica placements in the class of untangled multitrees is FPT, as parameterized by the replication factor \(\rho \) and the number of roots k. Our approach combines dynamic programming (DP) with a novel tree decomposition to find an optimal placement of \(\rho \) replicas on the leaves of a multitree with n nodes and k roots in \(O(n^2\rho ^{2k+3})\) time.
Divine Inspiration? An Examination of the Impact of Hallucinogens on the Production of Imagery among some South American Populations

Studies of shamanism in a variety of world cultures invariably have one fundamental connection: the shamans’ use of altered states of consciousness when healing or contacting the realm of the supernatural. Shamans–and indeed all humans–have a variety of mechanisms that can be used to transcend the physical world; asceticism, chanting, meditation, and hallucinatory drug use. The purpose of this examination is to explore the use of hallucinatory substances among the shamans of indigenous populations in South America. In conjunction with the use of alkaloid-based drugs, this paper explores the connection between hallucinogenic trances among shamans and visual expressionism and iconic motifs in these cultures. The current debate among anthropologists concerns the extent to which shamanistic “art” is a result of biological phosphenes that occur in all human beings or of culturally–defined images that one expects to see during trances (see Bednarik 1990, Lewis-Williams and Dowson 1990, Reichel-Dolmatoff 1978).
Statistical Deterministic and Ensemble Seasonal Prediction of Tropical Cyclones in the Northwest Australian Region

AbstractStatistical seasonal prediction of tropical cyclones (TCs) has been ongoing for quite some time in many different ocean basins across the world. While a few basins (e.g., North Atlantic and western North Pacific) have been extensively studied and forecasted for many years, Southern Hemispheric TCs have been less frequently studied and generally grouped as a whole or into two primary basins: southern Indian Ocean and Australian. This paper investigates the predictability of TCs in the northwest Australian (NWAUS) basin of the southeast Indian Ocean (105°–135°E) and describes two statistical approaches to the seasonal prediction of TC frequency, TC days, and accumulated cyclone energy (ACE). The first approach is a traditional deterministic seasonal prediction using predictors identified from NCEP–NCAR reanalysis fields using multiple linear regression. The second is a 100-member statistical ensemble approach with the same predictors as the deterministic model but with a resampling of the dataset wi...
Operator Spreading and the Emergence of Dissipative Hydrodynamics under Unitary Evolution with Conservation Laws

A new quantum model explores the emergence of irreversible macroscopic behavior from reversible microscopic dynamics.
Bibliometric analysis of authorship trends and collaboration dynamics over the past three decades of BONE's publication history

The existence of a gender gap in academia has been a hotly debated topic over the past several decades. It has been argued that due to the gender gap, it is more difficult for women to obtain higher positions. Manuscripts serve as an important measurement of one's accomplishments within a particular field of academia. Here, we analyzed, over the past 3 decades, authorship and other trends in manuscripts published in BONE, one of the premier journals in the field of bone and mineral metabolism. For this study, one complete year of manuscripts was evaluated (e.g. 1985, 1995, 2005, 2015) for each decade. A bibliometric analysis was then performed of authorship trends for those manuscripts. Analyzed fields included: average number of authors per manuscript, numerical position of the corresponding author, number of institutions collaborating on each manuscript, number of countries involved with each manuscript, number of references, and number of citations per manuscript. Each of these fields increased significantly over the 30-year time frame (p<10-6). The gender of both the first and corresponding authors was identified and analyzed over time and by region. There was a significant increase in the percentage of female first authors from 23.4% in 1985 to 47.8% in 2015 (p=0.001). The percentage of female corresponding authors also increased from 21.2% in 1985 to 35.4% in 2015 although it was not significant (p=0.07). With such a substantial emphasis being placed on publishing in academic medicine, it is crucial to comprehend the changes in publishing characteristics over time and geographical region. These findings highlight authorship trends in BONE over time as well as by region. Importantly, these findings also highlight where challenges still exist.
Optimal heavy-traffic queue length scaling in an incompletely saturated switch

We consider an input-queued switch operating under the MaxWeight scheduling algorithm. This system is interesting to study because it is a model for Internet routers and data center networks. Recently, it was shown that the MaxWeight algorithm has optimal heavy-traffic queue length scaling when all ports are uniformly saturated. Here we consider the case when an arbitrary number of ports are saturated (which we call the incompletely saturated case), and each port is allowed to saturate at a different rate. We use a recently developed drift technique to show that the heavy-traffic queue length under the MaxWeight scheduling algorithm has optimal scaling with respect to the switch size even in these cases.
Energetic Electron Acceleration and Injection During Dipolarization Events in Mercury's Magnetotail

Energetic particle bursts associated with dipolarization events within Mercury's magnetosphere were first observed by Mariner 10. The events appear analogous to particle injections accompanying dipolarization events at Earth. The Energetic Particle Spectrometer (3 s resolution) aboard MESSENGER determined the particle bursts are composed entirely of electrons with energies ≳ 300 keV. Here we use the Gamma-Ray Spectrometer high-time-resolution (10 ms) energetic electron measurements to examine the relationship between energetic electron injections and magnetic field dipolarization in Mercury's magnetotail. Between March 2013 and April 2015, we identify 2,976 electron burst events within Mercury's magnetotail, 538 of which are closely associated with dipolarization events. These dipolarizations are detected on the basis of their rapid (~2 s) increase in the northward component of the tail magnetic field (ΔBz ~30 nT), which typically persists for ~10 s. Similar to those at Earth, we find that these dipolarizations appear to be low-entropy, depleted flux tubes convecting planetward following the collapse of the inner magnetotail. We find that electrons experience brief, yet intense, betatron and Fermi acceleration during these dipolarizations, reaching energies ~130 keV and contributing to nightside precipitation. Thermal protons experience only modest betatron acceleration. While only ~25% of energetic electron events in Mercury's magnetotail are directly associated with dipolarization, the remaining events are consistent with the Near-Mercury Neutral Line model of magnetotail injection and eastward drift about Mercury, finding that electrons may participate in Shabansky-like closed drifts about the planet. Magnetotail dipolarization may be the dominant source of energetic electron acceleration in Mercury's magnetosphere.
It’s Unfair: Why Customers Who Merely Observe an Uncivil Employee Abandon the Company

Employees sometimes engage in uncivil behavior in the workplace. We ask (a) How commonly do customers witness an employee behaving uncivilly? (b) What negative effects does customers' witnessing of an employee’s uncivil behavior have on customers and firms? (c) Why do these effects occur? The results of three studies suggest that it is not uncommon for customers to witness an employee behaving in an uncivil manner. It occurs in many industries. Moreover, witnessing such behavior makes customers angry and creates desires to get back at the uncivil perpetrator and the firm. These effects occur even when a manager’s uncivil comment is aimed at correcting a subordinate’s job-related offense and even when it is delivered offstage, outside of the customer servicescape. Finally, we demonstrate that these effects are driven by customers' concerns about deontic injustice from incivility (reaction to a wrongful misconduct that violates fairness standards). These results contribute to the literature on workplace inc...