LLukas22/scidocs huggingface dataset:
Uniform Pricing in US Retail Chains

We show that most US food, drugstore, and mass merchandise chains charge nearly-uniform prices across stores, despite wide variation in consumer demographics and competition. Demand estimates reveal substantial within-chain variation in price elasticities and suggest that the median chain sacrifices $16m of annual profit relative to a benchmark of optimal prices. In contrast, differences in average prices between chains are broadly consistent with the optimal benchmark. We discuss a range of explanations for nearly-uniform pricing, highlighting managerial inertia and brand-image concerns as mechanisms frequently mentioned by industry participants. Relative to our optimal benchmark, uniform pricing may significantly increase the prices paid by poorer households relative to the rich, dampen the response of prices to local economic shocks, alter the analysis of mergers in antitrust, and shift the incidence of intra-national trade costs. ∗E-mail: sdellavi@berkeley.edu, gentzkow@stanford.edu. We thank Nicholas Bloom, Liran Einav, Benjamin Handel, Mitch Hoffman, Ali Hortacsu, Emir Kamenica, Kei Kawai, Carl Mela, Emi Nakamura, Peter Rossi, Stephen Seiler, Steven Tadelis, Sofia Villas-Boas. We thank seminar participants at Columbia University, MIT (Sloan), New York University, the San Francisco Federal Reserve, Stanford University (GSB), the University of Bonn, the University of Chicago (Department, Booth, Harris), UC Berkeley, UCLA, the University of Toronto, and conference participants at the NBER Summer Institute, the SITE Conference in Psychology and Economics, and the Berkeley-Paris conference in Organizational Economics for helpful comments. We thank Angie Acquatella, Sahil Chinoy, Bryan Chu, Johannes Hermle, Christopher Lim, Ammar Mahran, Akshay Rao, Sebastian Schaube, Avner Shlain, Patricia Sun, and Brian Wheaton for outstanding research assistance. Gentzkow acknowledges funding from the Stanford Institute for Economic Policy Research (SIEPR). Researcher(s) own analyses calculated (or derived) based in part on data from The Nielsen Company (US), LLC and marketing databases provided through the Nielsen Datasets at the Kilts Center for Marketing Data Center at The University of Chicago Booth School of Business. The conclusions drawn from the Nielsen data are those of the researcher(s) and do not reflect the views of Nielsen. Nielsen is not responsible for, had no role in, and was not involved in analyzing and preparing the results reported herein.
On-line active learning: A new paradigm to improve practical useability of data stream modeling methods

The central purpose of this survey is to provide readers an insight into the recent advances and challenges in on-line active learning. Active learning has attracted the data mining and machine learning community since around 20 years. This is because it served for important purposes to increase practical applicability of machine learning techniques, such as (i) to reduce annotation and measurement costs for operators and measurement equipments, (ii) to reduce manual labelling effort for experts and (iii) to reduce computation time for model training. Almost all of the current techniques focus on the classical pool-based approach, which is off-line by nature as iterating over a pool of (unlabelled) reference samples a multiple times to choose the most promising ones for improving the performance of the classifiers. This is achieved by (time-intensive) re-training cycles on all labelled samples available so far. For the on-line, stream mining case, the challenge is that the sample selection strategy has to operate in a fast, ideally single-pass manner. Some first approaches have been proposed during the last decade (starting from around 2005) with the usage of machine learning (ML) oriented incremental classifiers, which are able to update their parameters based on selected samples, but not their structures. Since 2012, on-line active learning concepts have been proposed in connection with the paradigm of evolving models, which are able to expand their knowledge into feature space regions so far unexplored. This opened the possibility to address a particular type of uncertainty, namely that one which stems from a significant novelty content in streams, as, e.g., caused by drifts, new operation modes, changing system behaviors or non-stationary environments. We will provide an overview about the concepts and techniques for sample selection and active learning within these two principal major research lines (incremental ML models versus evolving systems), a comparison of their essential characteristics and properties (raising some advantages and disadvantages), and a study on possible evaluation techniques for them. We conclude with an overview of real-world application examples where various online AL approaches have been already successfully applied in order to significantly reduce user’s interaction efforts and costs for model updates. Preprint submitted to Information Sciences 27 June 2017
Hypoxia, not the frequency of sleep apnea, induces acute hemodynamic stress in patients with chronic heart failure.

OBJECTIVES
This study was conducted to evaluate whether brain (B-type) natriuretic peptide (BNP) changes during sleep are associated with the frequency and severity of apneic/hypopneic episodes, intermittent arousals, and hypoxia.


BACKGROUND
Sleep apnea is strongly associated with heart failure (HF) and could conceivably worsen HF through increased sympathetic activity, hemodynamic stress, hypoxemia, and oxidative stress. If apneic activity does cause acute stress in HF, it should increase BNP.


METHODS
Sixty-four HF patients with New York Heart Association functional class II and III HF and ejection fraction <40% underwent a baseline sleep study. Five patients with no sleep apnea and 12 with severe sleep apnea underwent repeat sleep studies, during which blood was collected every 20 min for the measurement of BNP. Patients with severe sleep apnea also underwent a third sleep study with frequent BNP measurements while they were administered oxygen. This provided 643 observations with which to relate apnea to BNP. The association of log BNP with each of 6 markers of apnea severity was evaluated with repeated measures regression models.


RESULTS
There was no relationship between BNP and the number of apneic/hypopneic episodes or the number of arousals. However, the burden of hypoxemia (the time spent with oxygen saturation <90%) significantly predicted BNP concentrations; each 10% increase in duration of hypoxemia increased BNP by 9.6% (95% confidence interval: 1.5% to 17.7%, p = 0.02).


CONCLUSIONS
Hypoxemia appears to be an important factor that underlies the impact of sleep abnormalities on hemodynamic stress in patients with HF. Prevention of hypoxia might be especially important for these patients.
An Extended Lindley Poisson Distribution with Applications

Mavis Pararai Department of Mathematics, Indiana University of Pennsylvania, Indiana, PA, 15705, USA. Gayan Warahena-Liyanage Department of Mathematics, Indiana University of Pennsylvania, Indiana, PA, 15705, USA. Broderick O. Oluyede Department of Mathematical Sciences, Georgia Southern University, Statesboro, GA, 30460, USA. Abstract The Extended Lindley Poisson (ELP) distribution which is an extension of the extended Lindley distribution [2] is introduced and its properties are explored. This new distribution represents a more flexible model for the lifetime data. Some statistical properties of the proposed distribution including the shapes of the density, hazard rate functions, moments, Bonferroni and Lorenz curves are explored. Entropy measures and the distribution of the order statistics are given. The maximum likelihood estimation technique is used to estimate the model parameters and a simulation study is conducted to investigate the performance of the maximum likelihood estimates. Finally, we present applications of the model with a real data set to illustrate the usefulness of the proposed distribution.
On submeasures on Boolean algebras

We present a collection of observations and results concerning submeasures on Boolean algebras. They are all motivated by Maharam's problem and Talagrand's construction that solved it.
A Placebo-Controlled Trial of Dextromethorphan as an Adjunct in Opioid-Dependent Patients Undergoing Methadone Maintenance Treatment

BACKGROUND
Low-dose dextromethorphan (DM) might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. In a randomized, double-blind, controlled 12 week study, we investigated whether add-on dextromethorphan reduced cytokine levels and benefitted opioid-dependent patients undergoing methadone maintenance therapy (MMT).


METHODS
Patients were randomly assigned to a group: DM60 (60mg/day dextromethorphan; n = 65), DM120 (120mg/day dextromethorphan; n = 65), or placebo (n = 66). Primary outcomes were the methadone dose required, plasma morphine level, and retention in treatment. Plasma tumor necrosis factor (TNF)-α, C-reactive protein, interleukin (IL)-6, IL-8, transforming growth factor-β1, and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8, and 12. Multiple linear regressions with generalized estimating equation methods were used to examine the therapeutic effect.


RESULTS
After 12 weeks, the DM60 group had significantly longer treatment retention and lower plasma morphine levels than did the placebo group. Plasma TNF-α was significantly decreased in the DM60 group compared to the placebo group. However, changes in plasma cytokine levels, BDNF levels, and the methadone dose required in the three groups were not significantly different.


CONCLUSIONS
We provide evidence-decreased concomitant heroin use-of low-dose add-on DM's efficacy for treating opioid-dependent patients undergoing MMT.
Deep learning for computational chemistry

The rise and fall of artificial neural networks is well documented in the scientific literature of both computer science and computational chemistry. Yet almost two decades later, we are now seeing a resurgence of interest in deep learning, a machine learning algorithm based on multilayer neural networks. Within the last few years, we have seen the transformative impact of deep learning in many domains, particularly in speech recognition and computer vision, to the extent that the majority of expert practitioners in those field are now regularly eschewing prior established models in favor of deep learning models. In this review, we provide an introductory overview into the theory of deep neural networks and their unique properties that distinguish them from traditional machine learning algorithms used in cheminformatics. By providing an overview of the variety of emerging applications of deep neural networks, we highlight its ubiquity and broad applicability to a wide range of challenges in the field, including quantitative structure activity relationship, virtual screening, protein structure prediction, quantum chemistry, materials design, and property prediction. In reviewing the performance of deep neural networks, we observed a consistent outperformance against non-neural networks state-of-the-art models across disparate research topics, and deep neural network-based models often exceeded the "glass ceiling" expectations of their respective tasks. Coupled with the maturity of GPU-accelerated computing for training deep neural networks and the exponential growth of chemical data on which to train these networks on, we anticipate that deep learning algorithms will be a valuable tool for computational chemistry. © 2017 Wiley Periodicals, Inc.
Evolving magma sources during continental lithospheric extension: Insights from the Liaonan metamorphic core complex, eastern North China craton

Abstract The relation between magmatic activity and detachment faulting during continental lithospheric extension remains a persistent question. This paper takes the Liaonan metamorphic core complex (mcc) in the eastern North China craton as an example to explore how magma generation relates to detachment faulting in response to continental lithospheric extension due to the subduction of the Paleopacific plate beneath the Eurasian continent in the Early Cretaceous. Dating of lower plate granitic intrusions and trachy-dacitic volcanic rocks in the supradetachment basin constrains a progressive exhumation of the mcc between ca. 134 Ma and 113 Ma. Syn-tectonic magmatism is grouped into three types, i.e., early syn-kinematic, late syn-kinematic, and post-kinematic magmatism, in reference to detachment faulting. The magmatic rocks exhibit obvious differences in whole-rock Sr–Nd isotopes, implying varying sources, e.g., lithospheric mantle, juvenile and ancient lower crusts. Evolving magma sources during the progressive exhumation of the mcc are shown from one with a lithospheric mantle signature for the early syn-kinematic intrusions to one with mixed derivations from both juvenile and ancient lower crust for the late syn-kinematic plutons and volcanics and, finally, to a juvenile lower crust source for the post-kinematic intrusions. The source evolution of magmatism during the continental lithospheric extension implies that both crustal and mantle processes may have been involved in the magma generation. The Parallel Extension Tectonics model is applied to explain both the tectonic faulting and magmatic activities. In the model, the evolving magma sources accompanying the mcc exhumation were attributed to thinning of the cratonic lithosphere as a consequence of coupled crust–mantle detachment faulting during tectonic extension. The model can be applied to the variably extended provinces in the North China craton, but integrated structural, geochronological and geochemical studies are needed to present a comprehensive tectono-thermal (magmatic) history of these provinces.
IBM System/360 engineering

The cornerstone of the IBM System/360 philosophy is that the architecture of a computer is basically independent of its physical implementation. Therefore, in System/360, different physical implementations have been made of the single architectural definition which is illustrated in Figure 1.
German Multicenter Study Investigating 177Lu-PSMA-617 Radioligand Therapy in Advanced Prostate Cancer Patients.

177Lu-labeled PSMA-617 is a promising new therapeutic agent for radioligand therapy (RLT) of patients with metastatic castration-resistant prostate cancer (mCRPC). Initiated by the German Society of Nuclear Medicine, a retrospective multicenter data analysis was started in 2015 to evaluate efficacy and safety of 177Lu-PSMA-617 in a large cohort of patients.


METHODS
One hundred forty-five patients (median age, 73 y; range, 43-88 y) with mCRPC were treated with 177Lu-PSMA-617 in 12 therapy centers between February 2014 and July 2015 with 1-4 therapy cycles and an activity range of 2-8 GBq per cycle. Toxicity was categorized by the common toxicity criteria for adverse events (version 4.0) on the basis of serial blood tests and the attending physician's report. The primary endpoint for efficacy was biochemical response as defined by a prostate-specific antigen decline ≥ 50% from baseline to at least 2 wk after the start of RLT.


RESULTS
A total of 248 therapy cycles were performed in 145 patients. Data for biochemical response in 99 patients as well as data for physician-reported and laboratory-based toxicity in 145 and 121 patients, respectively, were available. The median follow-up was 16 wk (range, 2-30 wk). Nineteen patients died during the observation period. Grade 3-4 hematotoxicity occurred in 18 patients: 10%, 4%, and 3% of the patients experienced anemia, thrombocytopenia, and leukopenia, respectively. Xerostomia occurred in 8%. The overall biochemical response rate was 45% after all therapy cycles, whereas 40% of patients already responded after a single cycle. Elevated alkaline phosphatase and the presence of visceral metastases were negative predictors and the total number of therapy cycles positive predictors of biochemical response.


CONCLUSION
The present retrospective multicenter study of 177Lu-PSMA-617 RLT demonstrates favorable safety and high efficacy exceeding those of other third-line systemic therapies in mCRPC patients. Future phase II/III studies are warranted to elucidate the survival benefit of this new therapy in patients with mCRPC.
Advanced strategies for quality control of Chinese medicines.

Quality control is always the critical issue for Chinese medicines (CMs) with their worldwide increasing use. Different from western medicine, CMs are usually considered that multiple constituents are responsible for the therapeutic effects. Therefore, quality control of CMs is a challenge. In 2011, the strategies for quantification, related to the markers, reference compounds and approaches, in quality control of CMs were reviewed (Li, et al., J. Pharm. Biomed. Anal., 2011, 55, 802-809). Since then, some new strategies have been proposed in these fields. Therefore, the review on the strategies for quality control of CMs should be updated to improve the safety and efficacy of CMs. Herein, novel strategies related to quality marker discovery, reference compound development and advanced approaches (focused on glyco-analysis) for quality control, during 2011-2016, were summarized and discussed.
Incidence of alarplasty in primary and revision rhinoplasty in a private practice setting.

OBJECTIVE
To evaluate the incidence of alarplasty in primary and revision rhinoplasty during a 3-year period.


METHODS
We conducted a retrospective medical record review of patients undergoing primary and revision rhinoplasty between January 1, 2004, and December 31, 2006. Patients were divided into the following categories: primary or revision rhinoplasty, alarplasty, and ethnicity. The incidence of alarplasty was calculated and compared for primary vs revision rhinoplasty and for ethnicity. Statistically significant differences were confirmed using the chi(2) test.


RESULTS
A total of 168 patients underwent rhinoplasty with minimum follow-up of 6 months; 116 patients had primary rhinoplasty and 52 revision rhinoplasty. All alarplasties were bilateral. Of 50 alarplasties performed, 35 were in the primary group and 15 in the revision group. The incidence of alarplasty was 30.2% in the primary group and 28.8% in the revision group. Nonwhite patients had a higher overall incidence of alarplasty (63.0%) than did white patients (25.4%). Each ethnic category identified had a higher incidence of alarplasty than the white group.


CONCLUSIONS
Alarplasty is an important technique in rhinoplasty. The high incidence of alarplasty in revision rhinoplasty procedures suggests that alarplasty is underused by many surgeons currently performing rhinoplasty. One should consider alarplasty for all patients' noses, not just those of nonwhite ethnic rhinoplasty patients.
Long-term outcome after surgical treatment of nonparasitic splenic cysts

The optimal treatment for patients with nonparasitic splenic cysts is controversial. This study aimed to evalulate the clinical outcome of patients treated for a symptomatic splenic cyst, and to define a surgical strategy. Spleen-preserving surgery (9 laparotomies and 6 laparoscopies) was performed for a primary cyst in six patients and a secondary cyst in nine patients. The median follow-up time was 37.5 months. Partial splenic resection was performed for eight patients and cyst decapsulation for seven patients. Cyst recurrence was observed in four patients after decapsulation of a primary splenic cyst, as compared with none after resection. Postoperative complications were encountered only after laparotomy (5/9). The median hospital stay was 3.5 days (range, 2–5 days) after laparoscopy, as compared with 9 days (range, 5–14 days) after laparotomy. Symptomatic splenic cysts should be treated laparoscopically. For patients with recurrent or suspected primary splenic cysts, laparoscopic partial splenectomy is preferable. For other cases, a laparoscopic decapsulation is advocated.
Optimal Dispatching of Distributed Generators and Storage Systems for MV Islanded Microgrids

This paper presents an optimization procedure that enables the optimal dispatching of distributed generators and storage systems in a medium-voltage islanded microgrid. The network is assumed to be supplied by programmable (dispatchable) and nonprogrammable generators (i.e. nondispatchable, such as renewable energy sources-based units). The optimization goal is to minimize the overall microgrid operating cost and the pollutants emission of the programmable generators, assuming that all of the power made available by the renewable generators (photovoltaic and wind systems) is either directly injected into the network or stored in order to be subsequently delivered according to the proposed storage units' management strategy. The optimization is carried out by a niching evolutionary algorithm (NEA) that is able to find multiple optima and the variation of the objective function in their neighborhood. NEAs allow overcoming the performance of standard algorithms used for optimal power-flow calculations in power systems by avoiding falling into local optima. The optimization procedure is performed on a test microgrid and verified by computer simulations. The numerical results show that the solutions can always improve the microgrid performances irrespective of the network operating conditions in all of the considered cases.
Introducing a process manager in healthcare: an experience report

can be found at: Health Informatics Journal Additional services and information for http://jhi.sagepub.com/cgi/alerts  Email Alerts: http://jhi.sagepub.com/subscriptions  Subscriptions: http://www.sagepub.com/journalsReprints.nav Reprints: http://www.sagepub.com/journalsPermissions.nav Permissions: http://jhi.sagepub.com/cgi/content/refs/11/1/45 SAGE Journals Online and HighWire Press platforms): (this article cites 5 articles hosted on the Citations
Ultrasonication extraction and solid phase extraction clean-up for determination of US EPA 16 priority pollutant polycyclic aromatic hydrocarbons in soils by reversed-phase liquid chromatography with ultraviolet absorption detection1Presented in part at FACSS, the 23rd Annual Conference of the Feder

A method using ultrasonication extraction and solid phase extraction (SPE) clean-up for determination of US EPA 16 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in soils by reversed-phase liquid chromatography (RP-LC) with ultraviolet (UV) absorption detection was studied. Separation and detection of the 16 PAHs were completed in 31 min by RP-LC with a C18 column (Bakerbond PAH 6 PLUS 125 3.0 i.d. mm or Phenomenex ENVIROSEP-PP 125 3.2 i.d. mm), acetonitrile± water gradient elution and UV absorption detection. The detection limits, for a 10 ml of solution injection, determined at 254 nm were less than 1 mg/ml, except for acenaphthene, which was 1.05 mg/ml. Because individual PAHs are present in soils at the ng/g level or below and few sample matrices can be analyzed directly without serious interference, ef®cient extraction, preconcentration and clean-up of PAHs from the samples are indispensable prior to the determination of the PAHs. Several organic solvents were tested for extraction of the PAHs from soils, and ultrasonication extraction was used for the extraction in acetone of the 16 PAHs in soils. Several SPE procedures were tested and compared, and Supelco 6 ml LC-18 SPE cartridge and acetone:tetrahydrofuran (THF)1:1 eluant were used for the preconcentration and clean-up of the 16 PAHs in the soil. The method was successfully applied to determine the 16 PAHs in the soil sampled from an industrial land in the UK. # 1998 Elsevier Science B.V.