cssi/SciSciGPT-SciSciNet huggingface dataset:
Modeling Product Choices in a Peer Network

Consumers are uncertain about their preferences for innovative product attributes until the first trial. They search for information as a means of reducing uncertainty and improving the likelihood that they will be satisfied with their purchase. One way to receive information is through peer networks. As a peer network is often a priori unknown, we conduct an experiment to solicit self-reported peer nominations. We compare two mechanisms through which peer networks operate: Strength of social ties and perceived peer expertise, to draw inferences regarding consumers' preference reversal after exposure to peer recommendations. Our results indicate that perceived source expertise influences preferences while the closeness of social relationships has no statistically significant impact.
New extractors for interleaved sources

We study how to extract randomness from a C-interleaved source, that is, a source comprised of C independent sources whose bits or symbols are interleaved. We describe a simple approach for constructing such extractors that yields: For some δ > 0, c > 0, explicit extractors for 2-interleaved sources on {0, 1}2n when one source has min-entropy at least (1 - δ)n and the other has min-entropy at least c log n. The best previous construction, by Raz and Yehudayoff [36], worked only when both sources had entropy rate 1 - δ. For some c > 0 and any large enough prime p, explicit extractors for 2-interleaved sources on [p]2n when one source has min-entropy rate at least .51 and the other source has min-entropy rate at least (c log n)/n. We use these to obtain the following applications: We introduce the class of any-order-small-space sources, generalizing the class of small-space sources studied by Kamp et al. [22]. We construct extractors for such sources with min-entropy rate close to 1/2. Using the Raz-Yehudayoff construction would require entropy rate close to 1. For any large enough prime p, we exhibit an explicit function f: [p]2n → {0, 1} such that the randomized best-partition communication complexity of f with error 1/2 - 2-Ω(n) is at least .24n log p. Previously this was known only for a tiny constant instead of .24, for p = 2 [36]. We introduce non-malleable extractors in the interleaved model. For any large enough prime p, we give an explicit construction of a weak-seeded non-malleable extractor for sources over [p]n with min-entropy rate .51. Nothing was known previously, even for almost full min-entropy.
Stability Analysis for Composite Optimization Problems and Parametric Variational Systems

This paper aims to provide various applications for second-order variational analysis of extended-real-valued piecewise linear functions recently obtained by the authors. We mainly focus here on establishing relationships between full stability of local minimizers in composite optimization and Robinson's strong regularity of associated (linearized and nonlinearized) KKT systems. Finally, we address Lipschitzian stability of parametric variational systems with convex piecewise linear potentials.
Start-up Nation? Slave Wealth and Entrepreneurship in Civil War Maryland

Slave property rights yielded a source of collateral as well as a coerced labor force. Using data from Dun and Bradstreet linked to the 1860 census and slave schedules in Maryland, we find that slaveowners were more likely to start businesses prior to the uncompensated 1864 emancipation, even conditional on total wealth and human capital, and this advantage disappears after emancipation. We assess a number of potential explanations, and find suggestive evidence that this is due to the superiority of slave wealth as a source of collateral for credit rather than any advantage in production. The collateral dimension of slave property magnifies its importance to historical American economic development.
Phase-Amplitude Separation and Modeling of Spherical Trajectories

The problems of analysis and modeling of spherical trajectories, that is, continuous longitudinal data on S2, are important in several disciplines. These problems are challenging for two reasons: (...
Dual Role of Electron-Accepting Metal-Carboxylate Ligands: Reversible Expansion of Exciton Delocalization and Passivation of Nonradiative Trap-States in Molecule-like CdSe Nanocrystals

This paper reports large bathochromic shifts of up to 260 meV in both the excitonic absorption and emission peaks of oleylamine (OLA)-passivated molecule-like (CdSe)34 nanocrystals caused by postsynthetic treatment with the electron accepting Cd(O2CPh)2 complex at room temperature. These shifts are found to be reversible upon removal of Cd(O2CPh)2 by N,N,N′,N′-tetramethylethylene-1,2-diamine. 1H NMR and FTIR characterizations of the nanocrystals demonstrate that the OLA remained attached to the surface of the nanocrystals during the reversible removal of Cd(O2CPh)2. On the basis of surface ligand characterization, X-ray powder diffraction measurements, and additional control experiments, we propose that these peak red shifts are a consequence of the delocalization of confined exciton wave functions into the interfacial electronic states that are formed from interaction of the LUMO of the nanocrystals and the LUMO of Cd(O2CPh)2, as opposed to originating from a change in size or reorganization of the inorg...
Examining the role of stem cell biology in lung cancer

CN18-01 It has been demonstrated that some types of tumors (e.g. breast, brain, and lymphoid tumors) harbor a cancer stem cell (CSC) population that is required to maintain malignancy and which may harbor resistance to current therapeutic strategies. However, it is unknown whether lung cancers similarly harbor a cancer stem cell population. The identification and characterization of Bronchioalveolar Stem Cells (BASCs), putative resident stem cells of the distal lung, has suggested that these cells are important in normal lung homeostasis, lung tumor initiation and cancer progression. In mouse models of lung adenocarcinomas, BASCs undergo expansion after oncogene activation and/or tumor suppressor loss, and BASC-like cells persist within the developed tumors. We hypothesize that BASC-like cells within these lesions play a critical role in tumor maintenance. To address this question, we have developed an assay to test for lung CSCs. Orthotopic transplantations of primary murine lung adenocarcinoma cells via intratracheal injections into nude mice yield secondary tumors that recapitulate the features of the primary lung tumors. Transplantation of specific cell subsets from primary tumors into secondary hosts is currently being performed for comparison of their capacity for tumorigenesis. Our current data suggest that the BASC-like cells and the remaining tumor cells, once present within an established tumor, are equally sufficient to function as lung cancer stem cells. Further work will be needed to identify markers that will be useful for isolating a lung cancer stem cell population.
Characterization of Lung Nodule Malignancy Using Hybrid Shape and Appearance Features

Computed tomography imaging is a standard modality for detecting and assessing lung cancer. In order to evaluate the malignancy of lung nodules, clinical practice often involves expert qualitative ratings on several criteria describing a nodule’s appearance and shape. Translating these features for computer-aided diagnostics is challenging due to their subjective nature and the difficulties in gaining a complete description. In this paper, we propose a computerized approach to quantitatively evaluate both appearance distinctions and 3D surface variations. Nodule shape was modeled and parameterized using spherical harmonics, and appearance features were extracted using deep convolutional neural networks. Both sets of features were combined to estimate the nodule malignancy using a random forest classifier. The proposed algorithm was tested on the publicly available Lung Image Database Consortium dataset, achieving high accuracy. By providing lung nodule characterization, this method can provide a robust alternative reference opinion for lung cancer diagnosis.
Soft black hole absorption rates as conservation laws

The absorption rate of low-energy, or soft, electromagnetic radiation by spherically symmetric black holes in arbitrary dimensions is shown to be fixed by conservation of energy and large gauge transformations. We interpret this result as the explicit realization of the Hawking-Perry-Strominger Ward identity for large gauge transformations in the background of a non-evaporating black hole. Along the way we rederive and extend previous analytic results regarding the absorption rate for the minimal scalar and the photon.
Local Health Departments' Partners and Challenges in Electronic Exchange of Health Information.

Background Unprecedented amounts of data are produced by the health care and other sectors, presenting opportunities for local health departments (LHDs) to access these data. LHDs will need to participate in health information exchange (HIE) with a number of partners in order to benefit from these data resources. LHDs' participation in HIEs with specific partners has not been studied. Objectives To describe the level of and challenges in LHD participation in HIE with other partners, and variation by LHD population size and governance type. Data and methods This research uses data from the 2015 Informatics Capacity and Needs Assessment Survey, with a target population of all LHDs in the United States. A representative sample of 650 LHDs was drawn using a stratified random sampling design. A total of 324 completed responses were received with a 50% response rate. Survey data were cleaned, and bivariate comparisons were conducted using χ and Somer's D. Results Substantial variation existed in LHDs' participation in HIE by type of exchange partner. Although 71% participated in HIE with the state departments of health, only 12% with jail/correctional health, 14% with health or county-based purchasing plans, and 15% with home health agencies. Compared with large LHDs (jurisdiction populations of ≥500 000), smaller LHDs were more likely to participate in HIE with state departments of health, but less likely with other exchange partners. The challenges to HIE participation were technological, and organizational/interorganizational in nature and variation existed by LHDs' population size and governance structure with respect to state authority. Conclusions Local public health agencies more commonly participate in HIE with some partners, but may need to improve HIE with many others. National strategies targeting an increase in HIE of LHDs may use our findings to focus those initiatives.
Lepton-flavor violating mediators

We present a framework where dark matter interacts with the Standard Model through a light, spin-0 mediator that couples chirally to pairs of different-flavor leptons. This flavor violating final state weakens bounds on new physics coupled to leptons from terrestrial experiments and cosmic-ray measurements. As an example, we apply this framework to construct a model for the Fermi-LAT excess of GeV γ-rays from the galactic center. We comment on the viability of this portal for self-interacting dark matter explanations of small scale structure anomalies and embeddings in flavor models. Models of this type are shown to be compatible with the muon anomalous magnetic moment anomaly. We review current experimental constraints and identify possible future theoretical and experimental directions.
KNEE BRACES 2016: A GROWING APPRECIATION OF BENEFIT

Knee osteoarthritis (OA) is a debilitating and progressive condition that accounts for over 80% of the total osteoarthritis burden. Surgical intervention is the suitable option in end-stage osteoarthritis, however, in cases of less severe disease, it may be warranted to use non-operative methods. Knee braces have recently become a popular option as an addition to conventional treatment, and have displayed good results in improving function, reducing pain, and attenuating disease progression. Furthermore, other non-invasive modalities can be supplemented to bracing as a means to improve recovery and delay the need for surgery. Studies have indicated that the medial compartment of the knee sustains 62% of loading forces during the stance phase of regular gait, meanwhile the lateral compartment receives the remaining 38%. It is postulated that this distribution of knee loading forces is the reason why the medial compartment is more frequently deteriorated as compared to the lateral joint compartment. The use of medial compartment unloader braces can reduce these stresses by the means of distraction and rotation of the knee joint with the goal of increasing the medial joint space and producing pain relief. Knee bracing has the capability to enhance patients’ functional status, and even correct the gait changes associated with knee OA. Therefore, our goal is to assess: 1) the use of knee braces at our institution, and 2) the effectiveness of the various types of knee braces in treating OA associated knee pain.
From Egg to Embryo: A Peripatetic Journey.

The recent surge of interest in oocyte development has been spurred in large part by the increasing implementation of assisted reproductive technologies (ART) to treat human infertility. What is becoming apparent is that 'egg quality' is a primary factor in the success of ART (Sauer 1998), and yet we know virtually nothing about the molecular signature of a 'high quality' oocyte, i.e., an oocyte that is capable of maturing, being fertilized and supporting development to term. We are gaining marked insights, however, into how sperm activate eggs and the changes in gene expression that accompany preimplantation development. Nevertheless, embryo culture is known to effect gene expression (Rinaudo & Schultz 2004), the long-term consequences of which are only recently being unmasked. This review will briefly highlight these topics that were presented during the Biennial Joint Meeting of the UK Fertility Societies at Warwick University in April 2005.
Bounding Solutions of a Forced Oscillator

We give an alternate proof of a theorem in Wang and You (Z Angew Math Phys 47: 943–952, 1996) which shows that all solutions are bounded for a periodically forced nonlinear oscillator. Our proof relies on constructing an analytic change of variables by a convergent Lie series transformation to simplify the system so that the period map has large invariant curves by Moser’s theorem.
Investigating the thermal response of a micro-optical shutter

The thermal analysis of a fully integrated micro-switch for surety applications will be presented. Specifically, this study focuses on the temperature increase of a micromachined optical shutter with spot heating from a solid-state laser. To analyze the shutter response, a "design-to-analysis" interface has been developed that generates an accurate three-dimensional (3-D) solid geometry from the two-dimensional (2-D) mask layout. By building the "design-to-analysis" interface, engineers can use this solid modeler to virtually prototype and verify a design, and to simulate the performance of micro-devices before fabrication. To determine the effects of thermal conductivity and contact resistance on the thermal response of this passively cooled device, a sensitivity study is also performed.
Environment determines evolutionary trajectory in a constrained phenotypic space

Constraints on phenotypic variation limit the capacity of organisms to adapt to the multiple selection pressures encountered in natural environments. To better understand evolutionary dynamics in this context, we select Escherichia coli for faster migration through a porous environment, a process which depends on both motility and growth. We find that a trade-off between swimming speed and growth rate constrains the evolution of faster migration. Evolving faster migration in rich medium results in slow growth and fast swimming, while evolution in minimal medium results in fast growth and slow swimming. In each condition parallel genomic evolution drives adaptation through different mutations. We show that the trade-off is mediated by antagonistic pleiotropy through mutations that affect negative regulation. A model of the evolutionary process shows that the genetic capacity of an organism to vary traits can qualitatively depend on its environment, which in turn alters its evolutionary trajectory.
Creating/Developing/Using a Wiki Study Guide: Effects on Student Achievement

AbstractWikis are gaining popularity in classrooms because of their many benefits. Despite these benefits, there is a shortage of empirical data regarding their effectiveness in increasing knowledge. This study examined (a) the effectiveness of creating/developing/using a wiki to increase knowledge of Web 2.0 tools for 103 preservice teachers; (b) their perceptions of the use of a wiki to increase knowledge of Web 2.0 tools; (c) the frequency of use while participating in the reader, writer, and editor roles; and (d) their communication habits. The results revealed that there was a significant gain in achievement. Further, the preservice teachers reported that the wiki was effective for increasing their knowledge of Web 2.0 tools, and more than 75% used the wiki as an information source during and after the activity. The preservice teachers indicated that the creation of the wiki increased their knowledge as well as the presentations given by their peers, but the hands-on practice increased their knowledg...
The sputter generation of negative ion beams

Abstract A brief review is given of recent progress toward a quantitative understanding of negative ion formation by sputtering from surfaces covered with fractional layers of highly electropositive adsorbates. Recently developed models for estimating changes in the work function Δφ by electropositive adsorbates and techniques for scaling the Sigmund sputter theory into better agreement with experimental data are also briefly described. Several negative ion sources which exemplify the practical utilization of the sputter principle are described in terms of their intensity capabilities and beam qualities (emittances).
Pu 4f XPS spectra analyzed in the Anderson impurity model

Abstract X-ray photoemission spectra of the α, β, γ, and δ phases of Pu have been analyzed using the Gunnarsson–Schonhammer implementation of the Anderson impurity model. Changes in the relative spectral weights of the two features representing mixed f5 and f6 final states are in reasonable agreement with the model's predictions. The Coulomb terms, Uff and Ufc, are quite consistent with those derived from atomic and LDA calculations. Multiplet structure, which agrees with atomic calculations for 4f135f5, strongly suggests 5f localization in the final state.
Gender and Human Shielding

Human shielding occurs through the use of the body—an individual or collective physical presence—which is not armed and does not rely on the use of force or fire. Understood as both a means (human shields) and a method (human shielding), shielding is the use of “ civilians or other protected persons, whose presence or movement is aimed or used to render military targets immune from military operations .” Human shielding raises difficult doctrinal questions as to the interpretation and implementation of international humanitarian law that are not easily answered. This is in part because human shielding reanimates a series of queries that, as I argue elsewhere , are constitutive of international humanitarian law itself, namely: What and who is a combatant? What and who is a civilian? Who is to judge and according to which premises? Human shielding reanimates these questions because it is upon the definition of a civilian, in contradistinction to the combatant, that the power and efficacy of shielding depends. As I have shown, the distinction between civilian and combatant is partially constituted through discourses of gender which naturalize sex and sex difference . These discourses, as I sketch out below, are cited when theorizing the significance of human shields and reappear when evaluating the representation and meaning of the embodied movement of human shields.
Bayesian Inference in the Presence of Intractable Normalizing Functions

Models with intractable normalizing functions arise frequently in statistics. Common examples of such models include exponential random graph models for social networks and Markov point processes f...
Quantifying individual performance in Cricket — A network analysis of batsmen and bowlers

Abstract Quantifying individual performance in the game of Cricket is critical for team selection in International matches. The number of runs scored by batsmen and wickets taken by bowlers serves as a natural way of quantifying the performance of a cricketer. Traditionally the batsmen and bowlers are rated on their batting or bowling average respectively. However, in a game like Cricket it is always important the manner in which one scores the runs or claims a wicket. Scoring runs against a strong bowling line-up or delivering a brilliant performance against a team with a strong batting line-up deserves more credit. A player’s average is not able to capture this aspect of the game. In this paper we present a refined method to quantify the ‘quality’ of runs scored by a batsman or wickets taken by a bowler. We explore the application of Social Network Analysis (SNA) to rate the players in a team performance. We generate a directed and weighted network of batsmen–bowlers using the player-vs-player information available for Test cricket and ODI cricket. Additionally we generate a network of batsmen and bowlers based on the dismissal record of batsmen in the history of cricket—Test (1877–2011) and ODI (1971–2011). Our results show that M. Muralitharan is the most successful bowler in the history of Cricket. Our approach could potentially be applied in domestic matches to judge a player’s performance which in turn paves the way for a balanced team selection for International matches.
Analytic Continuation and Semiclassical Resolvent Estimates on Asymptotically Hyperbolic Spaces

In this paper we construct a parametrix for the high-energy asymptotics of the analytic continuation of the resolvent on a Riemannian manifold which is a small perturbation of the Poincare metric on hyperbolic space. As a result, we obtain non-trapping high energy estimates for this analytic continuation.
Boundaries of non-compact harmonic manifolds

In this paper we consider non-compact non-flat simply connected harmonic manifolds. In particular, we show that the Martin boundary and Busemann boundary coincide for such manifolds. For any finite volume quotient we show that (up to scaling) there is a unique Patterson–Sullivan measure and this measure coincides with the harmonic measure. As an application of these results we prove that the geodesic flow on a non-flat finite volume harmonic manifold without conjugate points is topologically transitive.
“Lose Like a Man”: Gender and the Constraints of Self-Making in Weight Watchers Online

Offering online programs that target men and women separately, Weight Watchers communicates, represents, and manipulates gender in its program marketing and materials. In this article, I demonstrate how Weight Watchers engages aspects of hegemonic masculinity as they endeavor to construct “masculine” versus “feminine” dieting through contrasting depictions of food, the body, and technology use. By analyzing the difference in the weight loss experiences that Weight Watchers Online promises, I argue that limited types of self are made available to women and men. Weight Watchers portrays female dieters on a difficult but actualizing and empowering journey toward a new and better self. Conversely, Weight Watchers depicts male clients losing weight easily, even effortlessly, but retaining a stable and immutable masculine selfhood throughout the process. This constraint upon self-making exposes how patriarchy subordinates even the men assumed to profit the most from its power, as the male weight loss promise withholds transformative potentials.
Stem cell divisions, somatic mutations, cancer etiology, and cancer prevention

Cancers are caused by mutations that may be inherited, induced by environmental factors, or result from DNA replication errors (R). We studied the relationship between the number of normal stem cell divisions and the risk of 17 cancer types in 69 countries throughout the world. The data revealed a strong correlation (median = 0.80) between cancer incidence and normal stem cell divisions in all countries, regardless of their environment. The major role of R mutations in cancer etiology was supported by an independent approach, based solely on cancer genome sequencing and epidemiological data, which suggested that R mutations are responsible for two-thirds of the mutations in human cancers. All of these results are consistent with epidemiological estimates of the fraction of cancers that can be prevented by changes in the environment. Moreover, they accentuate the importance of early detection and intervention to reduce deaths from the many cancers arising from unavoidable R mutations.
Factors Affecting Species Identifications of Blow Fly Pupae Based upon Chemical Profiles and Multivariate Statistics

Alternative methods for the identification of species of blow fly pupae have been developed over the years that consist of the analyses of chemical profiles. However, the effect of biotic and abiotic factors that could influence the predictive manner for the tests have not been evaluated. The lipids of blowfly pupae (Cochliomyia macellaria, Lucilia cuprina, Lucilia sericata, and Phormia regina) were extracted in pentane, derivatized, and analyzed by total-vaporization solid phase microextraction gas chromatography-mass spectrometry (TV-SPME GC-MS). Peak areas for 26 compounds were analyzed. Here we evaluated one biotic factor (colonization) on four species of blow flies to determine how well a model produced from lipid profiles of colonized flies predicted the species of flies of offspring of wild-caught flies and found very good species identification following 10 generations of inbreeding. When we evaluated four abiotic factors in our fly rearing protocols (temperature, humidity, pupation substrate, and diet), we found that the ability to assign the chemical profile to the correct species was greatly reduced.
On the Statistical Efficiency of Compositional Nonparametric Prediction

In this paper, we propose a compositional nonparametric method in which a model is expressed as a labeled binary tree of $2k+1$ nodes, where each node is either a summation, a multiplication, or the application of one of the $q$ basis functions to one of the $p$ covariates. We show that in order to recover a labeled binary tree from a given dataset, the sufficient number of samples is $O(k\log(pq)+\log(k!))$, and the necessary number of samples is $\Omega(k\log (pq)-\log(k!))$. We further propose a greedy algorithm for regression in order to validate our theoretical findings through synthetic experiments.
Are Audit-Related Factors Associated with Financial Reporting Quality in Nonprofit Organizations?

SUMMARY: We examine the effects of several audit-related factors on nonprofit financial reporting quality (FRQ). Using four different measures of FRQ, we demonstrate that the findings of nonprofit accounting research might be sensitive to the choice of FRQ proxy. Nonetheless, we consistently find that specialist auditors and unexplained audit fees have a significant positive effect on FRQ in nonprofit organizations. Interestingly, we observe changes to FRQ in the period after the Sarbanes-Oxley Act of 2002, despite the fact that the legislation does not apply to nonprofit audits. In fact, the results suggest nonprofits selected less-obvious methods of ratio management post-SOX, compared to pre-SOX. Finally, we do not find that Big N auditors consistently provide the highest quality, a result very different from for-profit studies.
The nexus of energy supply and human health

Uses of main primary energy resources, such as coal, oil, and solid biomass, are directly linked with adverse impacts on human health. Air pollution emitted from various activities in the energy supply chains is the main risk factor to human health, along with accidental and occupational risk exposures. Estimates of premature deaths are over four million per year for ambient air pollution (2015) and household or indoor air pollution (2012). More than 80 percent of the mortality from ambient air pollution emitted from the energy supply chains occurs in developing countries. The impact of household air pollution, mainly from traditional biomass used for cooking and space heating, disproportionately falls on women and children under age five years. Acute respiratory infections, mainly caused by household air pollution, are one of the largest categories of deaths (64 percent) of children under age five years in developing countries. These statistics indicate the deep nexus between the energy supply chain and human health. Yet, the negative implications for human health from energy use often receive inadequate consideration. It is critically important to take account of these human health impacts in developing energy supply plans and energy policies in developing countries.
Uncertainty quantification of thermal conductivities from equilibrium molecular dynamics simulations

Abstract Equilibrium molecular dynamics (EMD) simulations along with the Green-Kubo formula have been widely used to calculate lattice thermal conductivities. Previous studies, however, focused primarily on the calculated thermal conductivities, with the uncertainty of the thermal conductivities remaining poorly understood. In this paper, we study the quantification of the uncertainty by using solid argon, silicon, and germanium as model material systems, and examine the origin of the observed uncertainty. We find that the uncertainty increases with the upper limit of the correlation time, t corre,UL , and decreases with the total simulation time, t total , whereas the velocity initialization seed, simulation domain size, temperature, and type of material have minimal effects. The relative uncertainties of the thermal conductivities, σ k x / k x ,ave , for solid argon, silicon, and germanium under different simulation conditions all follow a similar trend, which can be fit with a “universal” square-root relation, as σ k x / k x ,ave = 2 ( t total / t corre,UL ) - 0.5 . We have also conducted statistical analysis of the EMD-predicted thermal conductivities and derived a formula that correlates the relative error bound (Q), confidence level (P), t corre,UL , t total , and number of independent simulations (N). We recommend choosing t corre,UL to be 5–10 times the effective phonon relaxation time, τ eff , and choosing t total and N based on the desired relative error bound and confidence level. This study provides new insights into understanding the uncertainty of EMD-predicted thermal conductivities. It also provides a guideline for running EMD simulations to achieve a desired relative error bound with a desired confidence level and for reporting EMD-predicted thermal conductivities.
Discrete Newton’s Algorithm for Parametric Submodular Function Minimization

We consider the line search problem in a submodular polyhedron \(P(f)\subseteq {\mathbb {R}}^n\): Given an arbitrary \(a\in {\mathbb {R}}^n\) and \(x_0\in P(f)\), compute \(\max \{\delta : x_0+\delta a\in P(f)\}\). The use of the discrete Newton’s algorithm for this line search problem is very natural, but no strongly polynomial bound on its number of iterations was known (Iwata 2008). We solve this open problem by providing a quadratic bound of \(n^2 + O(n \log ^2 n)\) on its number of iterations. Our result considerably improves upon the only other known strongly polynomial time algorithm, which is based on Megiddo’s parametric search framework and which requires \({\tilde{O}}(n^8)\) submodular function minimizations (Nagano 2007). As a by-product of our study, we prove (tight) bounds on the length of chains of ring families and geometrically increasing sequences of sets, which might be of independent interest.
EVALUATION OF A NEW MORPHOLOGICAL APPROXIMATION OF THE ARTICULAR SURFACES OF THE ANKLE JOINT

Background Total Ankle Replacement (TAR) has become a common surgical procedure for severe Osteoarthritis of the ankle. Unlike hip and knee, current TARs still suffer from high failure rates. A key reason could be their non-anatomical surface geometry design, which may produce unnatural motion and load-transfer characteristics. Current TARs have articular surfaces that are either cylindrical or truncated cone surfaces following the Inman truncated cone concept from more than 60 years ago [1]. Our recent study demonstrated, that the surfaces of the ankle can be approximated by a Saddle-shaped, Skewed, truncated Cone with its apex directed Laterally (SSCL) [2]. This is significantly different than the surface geometry used in current TAR systems. The goal of this study was to develop and test the reliability of an in vitro procedure to investigate the effect of different joint surface morphologies on the kinematics of the ankle and to use it to compare the effect of different joint surface morphologies on the 3D kinematics of the ankle complex. Methodology The study was conducted on ten cadaver ankle specimens. Image processing software (Analyze Direct TM ) was used to obtain 3D renderings of the articulating bones. The 3D bone models were then introduced into engineering design software packages (, Geomagic TM and Inventor TM ) to produce a set of four custom-fit virtual articular surfaces for each specimen: 1. Exact replica of the natural surfaces; 2. cylindrical; 3. truncated cone with apex oriented medially according to Inman9s postulate; and 4. SSCL. The virtual TAR implants were exported to a 3D printing software and 3D physical models of each implant was produced in PLA using 3D printing (Figure 1). The intact cadaver was tested first in a specially design loading and measuring system [3] in which external moments were applied across the ankle in the three planes of motion and the resulting motion was measured through a surgical navigation system (Figure 1). Each of the four customized implant sets were then surgically introduced one at a time and the test was repeated. From the results, the ankle, subtalar and complex kinematics could be compared to that of the intact natural joint. Results and Conclusions 1. Replacing the natural ankle joint surfaces by artificial exact replicas do not significantly affect the kinematic characteristics thus establishing good reliability of the experimental technique. This high reliability is an important finding proving that the combined factors involved in the process, such as replacing the natural surfaces with artificial replicas and the overall surgical procedure, do not significantly affect the kinematic characteristics of the ankle joint; 2. The SSCL implant produces close to intact joint kinematics (Figure 3), 3. The SSCL produces closer to normal kinematics then TARs with either cylindrical surfaces or those representing a symmetric truncated cone with apex oriented medially (Figure 3). For any figures or tables, please contact authors directly (see Info & Metrics tab above).
HIV and drug abuse mediate astrocyte senescence in a β-catenin-dependent manner leading to neuronal toxicity.

Summary Emerging evidence suggests that cell senescence plays an important role in aging-associated diseases including neurodegenerative diseases. HIV leads to a spectrum of neurologic diseases collectively termed HIV-associated neurocognitive disorders (HAND). Drug abuse, particularly methamphetamine (meth), is a frequently abused psychostimulant among HIV+ individuals and its abuse exacerbates HAND. The mechanism by which HIV and meth lead to brain cell dysregulation is not entirely clear. In this study, we evaluated the impact of HIV and meth on astrocyte senescence using in vitro and several animal models. Astrocytes constitute up to 50% of brain cells and play a pivotal role in marinating brain homeostasis. We show here that HIV and meth induce significant senescence of primary human fetal astrocytes, as evaluated by induction of senescence markers (β-galactosidase and p16INK4A), senescence-associated morphologic changes, and cell cycle arrest. HIV- and meth-mediated astrocyte senescence was also demonstrated in three small animal models (humanized mouse model of HIV/NSG-huPBMCs, HIV-transgenic rats, and in a meth administration rat model). Senescent astrocytes in turn mediated neuronal toxicity. Further, we show that β-catenin, a pro-survival/proliferation transcriptional co-activator, is downregulated by HIV and meth in human astrocytes and this downregulation promotes astrocyte senescence while induction of β-catenin blocks HIV- and meth-mediated astrocyte senescence. These studies, for the first time, demonstrate that HIV and meth induce astrocyte senescence and implicate the β-catenin pathway as potential therapeutic target to overcome astrocyte senescence.
Magnets in an electric field: hidden forces and momentum conservation

In 1967 Shockley and James addressed the situation of a magnet in an electric field. The magnet is at rest and contains electromagnetic momentum, but there was no obvious mechanical momentum to balance this for momentum conservation. They concluded that some sort of mechanical momentum, which they called “hidden momentum”, was contained in the magnet and ascribed this momentum to relativistic effects, a contention that was apparently confirmed by Coleman and Van Vleck. Since then, a magnetic dipole in an electric field has been considered to have this new form of momentum, but this view ignores the electromagnetic forces that arise when an electric field is applied to a magnet or a magnet is formed in an electric field. The electromagnetic forces result in the magnet-charge system gaining electromagnetic momentum and an equal and opposite amount of mechanical momentum so that it is moving in its original rest frame. This moving reference frame is erroneously taken to be the rest frame in studies that purport to show hidden momentum. Here I examine the analysis of Shockley and James and of Coleman and Van Vleck and consider a model of a magnetic dipole formed in a uniform electric field. These calculations show no hidden momentum.
Learning and job search dynamics during the Great Recession

Abstract Krueger and Mueller (2011) document that search effort declined with unemployment duration during the Great Recession. I show that variation in past effort explains this decline. Furthermore, job offers increase subsequent effort. These facts are inconsistent with standard models of search. I introduce a model of sequential search in which workers are uncertain about the offer arrival process and learn through search. Evolving beliefs influence search through two competing channels: the opportunity cost of leisure and the option value of unemployment. Estimation of the model indicates that learning provides a strong account of job search dynamics during the Great Recession.
Form Factor Enhancement of Imaging Systems using a Cubic Phase Mask

A wavefront encoding technique for achieving flat form factor imaging sensors is presented. The resultant configuration maintains the light gathering ability of larger apertures while maintaining or exceeding angular resolution over a reduced working distance.
The toroidal field coil design for ARIES-ST

Abstract An evolutionary process was used to develop the toroidal field (TF) coil design for the ARIES-spherical torus (ST). Design considerations included fabricability, assembly, maintenance, energy efficiency, and structural robustness. Design options were identified early in the process. Trade studies were carried out to identify preferred choices. Design points were re-optimized based on the design choices in the TF and other systems. An attractive design for the ARIES-ST TF coil system evolved. This design addresses a number of the concerns (complexity) and criticisms (high cost, high recirculating power) of fusion. It does this by: applying advanced, but available laser forming and spray casting techniques for manufacturing the TF coil system; adopting a simple single turn TF coil system to make assembly and maintenance much easier. The single turn design avoids the necessity of using the insulation as a structural component of the TF coils, and hence, is much more robust than multi-turn designs; using a high conductivity copper alloy and modest current densities to keep the recirculating power modest.
Abdominal Wall Reconstruction in the Prune Belly Syndrome

In our institution, 12 patients have been encountered with prune belly syndrome. Eight children have undergone evaluation of their abdominal musculature by electromyography. Results of their studies show that major functioning or recoverable muscle exists in the lateral and upper sector of the abdomen, but that little or no muscle exists in the lower central abdomen. Based in part on these findings, an operation has been devised which spares all potentially functioning musculature and corresponding motor nerves, and disposes of nonfunctioning and nonrecoverable muscle. In terms of cosmetic appearance and gross motor testing, these growing boys show significant improvement.
The Rationale and Results in Two-Stage Orchidopexies

Abstract The two-stage orchidopexies for cryptorchidism done over a period of 20 yr were reviewed. It was found that of 60 staged orchidopexies attempted, 56 were successfully completed. Based on follow-up of 40 testes, the 82% anatomical results would seem to support the assertion that staged orchidopexy is the procedure of choice for the "difficult" undescended testis with a primarily short blood supply. The results in a small group of bilateral two-stage procedures did not justify as great an optimism in regard to fertility.
Implementing NFPA 70E for arc flash safety

The OSHA General Duty Clause states that each employer shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees (OSHA 1970). Furthermore, a review of OSHA 29CFR 1910.335 (a) (1)(i) which requires the use of protective equipment when working where a potential electrical hazard exists and 29CFR 1910.132(d)(1) which requires the employer assess the workplace for hazards and the need for personal protective equipment, are given to show the importance of NFPA 70E (OSHA 1990) (OSHA 1994).
Training and Effort Dynamics in Apprenticeship

A principal specifies time paths of effort provision, task allocation, and knowledge transfer for a cash-constrained apprentice, who is free to walk away at any time. In the optimal contract the apprentice pays for training by working for low or no wages and by working inefficiently hard. The apprentice can work on both knowledge-complementary and knowledge-independent tasks. We study the optimal time path of effort distortions and their impact on the knowledge transfer, and analyze the effect of regulatory limits on the length of apprenticeships and on how much effort apprentices are allowed to provide.
Efficient identification of Tanimoto nearest neighbors

Tanimoto, or extended Jaccard, is an important similarity measure which has seen prominent use in fields such as data mining and chemoinformatics. Many of the existing state-of-the-art methods for market basket analysis, plagiarism and anomaly detection, compound database search, and ligand-based virtual screening rely heavily on identifying Tanimoto nearest neighbors. Given the rapidly increasing size of data that must be analyzed, new algorithms are needed that can speed up nearest neighbor search, while at the same time providing reliable results. While many search algorithms address the complexity of the task by retrieving only some of the nearest neighbors, we propose a method that finds all of the exact nearest neighbors efficiently by leveraging recent advances in similarity search filtering. We provide tighter filtering bounds for the Tanimoto coefficient and show that our method, TAPNN, greatly outperforms existing baselines across a variety of real-world datasets and similarity thresholds.
Mitochondrial regulation of hematopoietic stem cells

Hematopoietic stem cells (HSCs) preferentially use glycolysis rather than mitochondrial oxidative phosphorylation for energy production. While glycolysis in HSC is typically viewed as response to a hypoxic bone marrow environment that protects HSC from damaging reactive oxygen species, other interpretations are possible. Furthermore, recent evidence directly supports a critical role for mitochondria in the maintenance and function of HSCs that goes beyond ATP production. Here, we review recent advances in our understanding of metabolism and the role of mitochondria in the biology of HSCs.
Crack detection in crystalline silicon solar cells using dark-field imaging

Abstract The high capital expenditure (capex) necessary to manufacture crystalline silicon PV modules negatively affects the levelized cost of electricity (¢/kWh) and critically impacts the rate at which the PV industry can scale up. Wafer, cell, and module fabrication with thin free-standing silicon wafers is one key to reduce capex. Thin wafers reduce capex associated with silicon refining and wafer fabrication, which together sum to 58% of the total capex of silicon module manufacturing. In addition, thin wafers directly and significantly reduce variable costs. However, introducing 50 μm thin free-standing wafers into today’s manufacturing lines result in cracking, creating a yield-based disincentive. Due to the brittle nature of silicon, wafer breakage is the major concern due to the high stress that is induced during processes in manufacturing lines. In this paper, we describe an improved method for edge micro-crack detection that can help enable low-capex, thin free-standing Si wafers. We present a method of detecting and measuring cracks along wafer edges by using a dark-field IR scattering imaging technique which enables detection of edge cracks at the micron scale.
Efficiency‐adjusted public capital, capital grants, and growth

A debate on whether capital grants, and especially European Union (EU) funds, actually contribute to growth has gained prominence lately. This article empirically assesses the relationship between the quality of public investment, capital grants, and growth in a sample of 43 emerging and peripheral economies over 1991–2015. To this end, the contribution of public capital to growth is estimated using efficiency‐adjusted public capital stock series, which reflects the quality of public investment management institutions. In addition, the determinants of effective public investment are analyzed. The results suggest that capital grants contribute positively to effective public investment, and the latter is significant in explaining variations in economic growth. Finally, the article illustrates the impact of raising EU funds absorption on potential growth in emerging and peripheral EU countries.
Recurring Firm Events and Predictable Returns: The Within-Firm Time Series

We review the literature on recurring firm events and predictable returns. Many common firm events recur on a predictable basis, such as earnings and dividends, among others. These events tend to be associated with large positive returns in the period when the events are predicted to occur (without conditioning on the outcome or existence of the event itself). These returns occur mainly on the long side of the portfolio, are statistically and economically large when value weighted, and replicate internationally. It is difficult to explain the observed patterns with a unified risk theory. Some of the underlying causes seem to be related to idiosyncratic risk, predictable attention, probability mistakes, and demand for corporate distributions.