cssi/SciSciGPT-SciSciNet huggingface dataset:
Spatial aggregation of holistically-nested convolutional neural networks for automated pancreas localization and segmentation.

Abstract Accurate and automatic organ segmentation from 3D radiological scans is an important yet challenging problem for medical image analysis. Specifically, as a small, soft, and flexible abdominal organ, the pancreas demonstrates very high inter-patient anatomical variability in both its shape and volume. This inhibits traditional automated segmentation methods from achieving high accuracies, especially compared to the performance obtained for other organs, such as the liver, heart or kidneys. To fill this gap, we present an automated system from 3D computed tomography (CT) volumes that is based on a two-stage cascaded approach—pancreas localization and pancreas segmentation. For the first step, we localize the pancreas from the entire 3D CT scan, providing a reliable bounding box for the more refined segmentation step. We introduce a fully deep-learning approach, based on an efficient application of holistically-nested convolutional networks (HNNs) on the three orthogonal axial, sagittal, and coronal views. The resulting HNN per-pixel probability maps are then fused using pooling to reliably produce a 3D bounding box of the pancreas that maximizes the recall. We show that our introduced localizer compares favorably to both a conventional non-deep-learning method and a recent hybrid approach based on spatial aggregation of superpixels using random forest classification. The second, segmentation, phase operates within the computed bounding box and integrates semantic mid-level cues of deeply-learned organ interior and boundary maps, obtained by two additional and separate realizations of HNNs. By integrating these two mid-level cues, our method is capable of generating boundary-preserving pixel-wise class label maps that result in the final pancreas segmentation. Quantitative evaluation is performed on a publicly available dataset of 82 patient CT scans using 4-fold cross-validation (CV). We achieve a (mean ± std. dev.) Dice similarity coefficient (DSC) of 81.27 ± 6.27% in validation, which significantly outperforms both a previous state-of-the art method and a preliminary version of this work that report DSCs of 71.80 ± 10.70% and 78.01 ± 8.20%, respectively, using the same dataset.
Particle Swarm Optimization-Based Band Selection for Hyperspectral Target Detection

This letter proposes particle swarm optimization (PSO)-based band selection (BS) approach for hyperspectral target detection. Due to lack of training samples in a detection problem, it is more difficult than classification-purposed BS. The objective function, called maximum-submaximum-ratio (MSR) gauging target-background separation, is proposed for target detection during PSO searching. Typical target detectors such as target-constrained interference-minimized filter and adaptive coherence estimator are studied. Experimental results demonstrate that the proposed MSR-based objective function in conjunction with PSO-based searching can select a small band set while yielding similar or even better detection performance than using all the original bands, sequential forward search-based BS, or BS relying on detection map similarity assessment.
Learning opacity in Stratal Maximum Entropy Grammar

Opaque phonological patterns are sometimes claimed to be difficult to learn; specific hypotheses have been advanced about the relative difficulty of particular kinds of opaque processes (Kiparsky 1971, 1973), and the kind of data that is helpful in learning an opaque pattern (Kiparsky 2000). In this paper, we present a computationally implemented learning theory for one grammatical theory of opacity, a Maximum Entropy version of Stratal OT (Bermudez-Otero 1999, Kiparsky 2000), and test it on simplified versions of opaque French tense–lax vowel alternations and the opaque interaction of diphthong raising and flapping in Canadian English. We find that the difficulty of opacity can be influenced by evidence for stratal affiliation: the Canadian English case is easier if the learner encounters application of raising outside the flapping context, or non-application of raising between words (e.g. life with [ʌɪ]; lie for with [aɪ]).
Traveling-Wave Antenna for Fast-Wave Heating and Current Drive in Tokamaks

The travelling-wave antenna for heating and current drive in the ion cyclotron range of frequencies is shown theoretically to have loading and wavenumber spectra that are largely independent of plasma conditions. These characteristics have been demonstrated in low-power experiments on the DIII-D tokamak, in which a standard four-strap antenna was converted to a traveling-wave antenna through use of external coupling elements. The experiments indicate that the array maintains good impedance matching without dynamic tuning during abrupt changes in the plasma, such as during L- to H-mode transitions, edge-localized mode activity, and disruptions. An analytic model was developed that exhibits the features observed in the experiments. Guidelines for the design of travelling-wave antennas are derived from the validated model. 11 refs., 14 figs.
Evaluating Changes in the Transmission Mechanism of Government Spending Shocks

We empirically revisit the crowding-in effect of government spending on private consumption based on rolling windows of U.S. data. Results show that in earlier samples government spending is increasingly crowding in private consumption; however, this relation is reverted in the latest periods. We propose a model embedding non-separable public and private consumption in the utility function and rule-of-thumb consumers to assess the sources of non-monotonic changes in the transmission of the shock. The iterative full information estimation of the model reveals that changes in the co-movement between private and public spending is primarily driven by the fluctuations in the elasticity of substitution between private and public consumption, the share of financially constrained consumers, and the elasticity of intertemporal substitution.
CHARACTERIZATION OF SPONTANEOUS AND INDUCED PUBERTY IN GIRLS WITH TURNER SYNDROME.

ABSTRACT Objective: To characterize puberty in girls with Turner syndrome (TS) and determine whether specific patient characteristics are associated with the timing of menarche. We also sought to compare spontaneous versus induced puberty in these patients. Methods: Medical records of girls followed in our Pediatric Endocrine clinic for TS from 2007 to 2015 were reviewed. Results: Fifty-three girls were included, of whom 10 (19%) achieved menarche spontaneously and 43 (81%) received hormone replacement therapy (HRT). Of girls receiving HRT, a younger age at estrogen initiation correlated with a longer time to menarche (P = .02), and a mosaic karyotype was associated with a shorter time to menarche (P = .02), whereas no relationship was seen for body mass index, estrogen regimen, or maternal age at menarche. Nineteen girls (44%) receiving HRT had bleeding on estrogen alone at a wide dose range and were more likely to be on transdermal than oral preparations (P = .01). Girls with spontaneous puberty achieved menarche at a younger age (P Conclusion: Significant variability in the timing of menarche exists among girls with TS. However, age at pubertal induction and karyotype were significantly correlated with age at menarche in our patients. A wide range of estrogen doses is seen in girls who bleed prior to progesterone, suggesting extreme variability in estrogen sensitivity among patients with TS. Girls achieving spontaneous menarche are younger and more likely to have a mosaic karyotype than those with induced menarche. Large-scale prospective studies are needed to confirm these results. Abbreviations: BMI = body mass index; HRT = hormone replacement therapy; TS = Turner syndrome
Activity of Sulfa Drugs and Their Combinations against Stationary Phase B. burgdorferi In Vitro.

Lyme disease is a most common vector-borne disease in the US. Although the majority of Lyme patients can be cured with the standard two- to four-week antibiotic treatment, at least 10%–20% of patients continue to suffer from prolonged post-treatment Lyme disease syndrome (PTLDS). While the cause for this is unclear, one possibility is that persisting organisms are not killed by current Lyme antibiotics. In our previous studies, we screened an FDA drug library and an NCI compound library on B. burgdorferi and found some drug hits including sulfa drugs as having good activity against B. burgdorferi stationary phase cells. In this study, we evaluated the relative activity of three commonly used sulfa drugs, sulfamethoxazole (Smx), dapsone (Dps), sulfachlorpyridazine (Scp), and also trimethoprim (Tmp), and assessed their combinations with the commonly prescribed Lyme antibiotics for activities against B. burgdorferi stationary phase cells. Using the same molarity concentration, dapsone, sulfachlorpyridazine and trimethoprim showed very similar activity against stationary phase B. burgdorferi enriched in persisters; however, sulfamethoxazole was the least active drug among the three sulfa drugs tested. Interestingly, contrary to other bacterial systems, Tmp did not show synergy in drug combinations with the three sulfa drugs at their clinically relevant serum concentrations against B. burgdorferi. We found that sulfa drugs combined with other antibiotics were more active than their respective single drugs and that four-drug combinations were more active than three-drug combinations. Four-drug combinations dapsone + minocycline + cefuroxime + azithromycin and dapsone + minocycline + cefuroxime + rifampin showed the best activity against stationary phase B. burgdorferi in these sulfa drug combinations. However, these four-sulfa-drug–containing combinations still had considerably less activity against B. burgdorferi stationary phase cells than the Daptomycin + cefuroxime + doxycycline used as a positive control which completely eradicated B. burgdorferi stationary phase cells. Future studies are needed to evaluate and optimize the sulfa drug combinations in vitro and also in animal models.
Semidefinite programming approach for the quadratic assignment problem with a sparse graph

The matching problem between two adjacency matrices can be formulated as the NP-hard quadratic assignment problem (QAP). Previous work on semidefinite programming (SDP) relaxations to the QAP have produced solutions that are often tight in practice, but such SDPs typically scale badly, involving matrix variables of dimension $$n^2$$ where n is the number of nodes. To achieve a speed up, we propose a further relaxation of the SDP involving a number of positive semidefinite matrices of dimension $$\mathcal {O}(n)$$ no greater than the number of edges in one of the graphs. The relaxation can be further strengthened by considering cliques in the graph, instead of edges. The dual problem of this novel relaxation has a natural three-block structure that can be solved via a convergent Alternating Direction Method of Multipliers in a distributed manner, where the most expensive step per iteration is computing the eigendecomposition of matrices of dimension $$\mathcal {O}(n)$$ . The new SDP relaxation produces strong bounds on quadratic assignment problems where one of the graphs is sparse with reduced computational complexity and running times, and can be used in the context of nuclear magnetic resonance spectroscopy to tackle the assignment problem.
Estimating the Gains from New Rail Transit Investment: A Machine Learning Tree Approach

Urban rail transit investments are expensive and irreversible. As people differ with respect to their demand for trips, their value of time, and the types of real estate they live in, such projects are likely to offer heterogeneous benefits to residents of a city. Defining the opening of a major new subway in Seoul as a treatment for apartments close to the new rail stations, we contrast hedonic estimates based on multivariate hedonic methods with a machine learning (ML) approach. This ML approach yields new estimates of these heterogeneous effects. While a majority of the “treated” apartment types appreciate in value, other types decline in value. We cross‐validate our estimates by studying what types of new housing units developers build in the treated areas close to the new train lines.
Measuring the size of the shadow economy using a dynamic general equilibrium model with trends

We propose a methodology for measuring the size and properties of the shadow economy. We use a two-sector dynamic deterministic general equilibrium model with four different trends: hours worked, investment-specific productivity, formal productivity, and shadow productivity. We find that the shadow productivity trend is endogenous, in the sense that it is an exact function of model parameters and the other three trends. We also document that, in order to be consistent with observed (real-world) trend growths, the shadow sector needs to exhibit increasing returns to scale, which is contrary to the standard procedure of imposing decreasing returns to this sector. We apply our methodology to a set of seven Latin American and Asian countries and document several empirical regularities that emerge from our analysis, the most important one being that the volatility of shadow sector output is considerably larger than the one in formal sector output.
Mid-infrared ultrafast carrier dynamics in thin film black phosphorus

Black phosphorus is emerging as a promising semiconductor for electronic and optoelectronic applications. To study fundamental carrier properties, we performed ultrafast femtosecond pump-probe spectroscopy on thin film black phosphorus mechanically exfoliated on a glass substrate. Carriers (electrons and holes) were excited to high energy levels and the process of carrier relaxation through phonon emission and recombination was probed. We used a wide range of probing wavelengths up to and across the band gap to study the evolution of the relaxation dynamics at different energy levels. Our experiments revealed a plethora of important physical phenomena. The fast relaxation time constants, associated with carrier-phonon scattering, steadily increase as the energy of the probe beam approaches the band gap energy, which was determined to be 0.31 eV, and the carrier recombination rate was obtained when the probe wavelength was tuned to match the band gap energy. The carrier-phonon scattering rates were found to be similar along the armchair and zigzag directions, therefore, the anisotropic carrier mobility reported in literature is mainly due to the difference in effective mass of carriers along different directions. The ultrafast spectroscopy data further revealed the oxidation induced surface charges. Our results highlight the importance of using the spectroscopy technique, in this case, in the mid-IR range, to uncover useful physical processes.
Dynamic d-symmetry Bose condensate of a planar-large-bipolaron liquid in cuprate superconductors

Planar-large-bipolarons can form if the ratio of the surrounding mediums’ static to high-frequency dielectric constants is especially large, e0/e∞ >> 2. A large-bipolaron in p-doped La2CuO4 is mode...
Probabilistic Program Abstractions

Abstraction is a fundamental tool for reasoning about a complex system. Program abstraction has been utilized to great effect for analyzing deterministic programs. At the heart of a program abstraction is a connection between the abstract program, which is simple to analyze, and the concrete program, which may be extremely complex. Program abstractions, however, are typically not probabilistic. In this thesis I generalize a particular class of non- deterministic program abstractions known as sound over-approximations to the probabilistic context. Sound over-approximations are a family of abstract programs which are guaranteed to contain the original program as a subset of their behavior. This thesis shows that when imbued with a probabilistic semantics, sound over-approximations define a family of probabilistic programs which capture key properties of the original program. It then introduces a mechanism for generating sound probabilistic over-approximations as a generalization of a well-known program abstraction technique known as predicate abstraction. Finally, the problem of inference and learning in the context of probabilistic program abstractions are briefly described.
Permanent His bundle pacing: Electrophysiological and echocardiographic observations from long-term follow-up.

BACKGROUND Permanent His bundle pacing (HBP) is a physiological alternative to right ventricular pacing. It is not known whether HBP can cause His-Purkinje conduction (HPC) disease. The aim of our study is to assess His bundle capture and its effect on left ventricular (LV) function in long-term follow-up and to determine HPC at the time of pulse generator change (GC) in patients with chronic HBP. METHODS HB electrograms were recorded from the pacing lead at implant and GC. HBP QRS duration (QRSd), His-ventricular (HV) intervals, and HB pacing thresholds at GC were compared with implant measurements. HPC was assessed by pacing at cycle lengths of 700 ms, 600 ms, and 500 ms at GC. LV internal diameters, ejection fraction (EF), and valve dysfunction at baseline were compared with echocardiography during follow-up. RESULTS GC was performed in 20 patients (men 13; age 74 ± 14 years) with HBP at 70 ± 24 months postimplant. HV intervals remained unchanged from initial implant (44 ± 4 ms vs 45 ± 4 ms). During HBP at 700 ms, 600 ms, and 500 ms (n = 17), consistent 1:1 HPC was present. HBP QRSd remained unchanged during follow-up (117 ± 20 ms vs 118 ± 23 ms). HBP threshold at implant and GC was 1.9 ± 1.1 V and 2.5 ± 1.2 V @ 0.5 ms. Despite high pacing burden (77 ± 13%), there was no significant change in LVEF (50 ± 14% at implant) during follow-up (55 ± 6%, P = 0.06). CONCLUSIONS HBP does not appear to cause new HPC abnormalities and is associated with stable HBP QRSd during long-term follow-up. Despite high pacing burden, HBP did not result in deterioration of left ventricular systolic function or cause new valve dysfunction.
On hardening problems in critical infrastructure systems

Abstract The power and communication networks are highly interdependent and form a part of the critical infrastructure of a country. Similarly, dependencies exist within the networks itself. It is essential to have a model which captures these dependencies precisely. Previous research has proposed certain models but these models have certain limitations. The limitations of the aforementioned models have been overcome by the Implicative Interdependency Model, which uses Boolean Logic to denote the dependencies. This paper formulates the Entity Hardening problem and the Targeted Entity Hardening problem using the Implicative Interdependency Model. The Entity Hardening problem describes a situation where an operator, with a limited budget, must decide which entities to harden, which in turn would minimize the damage, provided a set of entities fail initially. The Targeted Entity Hardening problem is a restricted version of the Entity Hardening problem. This problem presents a scenario where, the protection of certain entities is of higher priority. If these entities were to be nonfunctional, the economic and societal damage would be higher when compared to other entities being nonfunctional. It has been shown that both problems are NP-Complete. An Integer Linear Program (ILP) has been devised to find the optimal solution. A heuristic has been described whose accuracy is found by comparing its performance with the optimal solution using real-world and simulated data.
Monadic Decomposition

Monadic predicates play a prominent role in many decidable cases, including decision procedures for symbolic automata. We are here interested in discovering whether a formula can be rewritten into a Boolean combination of monadic predicates. Our setting is quantifier-free formulas whose satisfiability is decidable, such as linear arithmetic. Here we develop a semidecision procedure for extracting a monadic decomposition of a formula when it exists.
Approximation Schemes for Stochastic Teams with Weakly Coupled Agents

Abstract The main objective of this Papers is to develop a new iterative approach towards the Solution of dynamic stochastic teams when the coupling among a subset of agents is weak. either throughth the state dynamics or through the performance index. In each case. the weak coupling is characterized in terms of number of small (pertuhrltion) parameters. When these parameter values are set equal to Zero . the original fairly complex dynamic team. with a quasiclassical or a non classica information pattern is decomposed into relatively simpler storhastic control and team problems.the solution of which make up t he zerorh order approximation (in a function space) to the team-optimal solution of the original problem. Using this asastarling point for an ite ra tion. We show that approximations of all orders can be obtained by solving a sequence of stochastic control and/or simplper team problems. The paper studies. particlliarly two agents LQG team.With quasiciassicai or non classical information patterns. but the approach is applicable to other models (with more than two agents and non-Gaussian sta tislics) as well.
Electrical effects of DNA molecules on silicon field effect transistor

Much research has been devoted to the field of DNA detection for biotechnology and medical diagnostics. Conventionally, this has involved lab-scale large instruments such as fluorescent microscope, with DNA binding and tagging. Recently, however, the possibility of label-free, rapid, sensitive and miniaturized DNA detection electronically has attracted increasing interest in the field. To investigate the feasibility of DNA detection by the semiconductor field effect without tagging or binding agents, we studied the effects of DNA molecules directly on the gate oxide of field effect transistors (FET). DNA solution was deposited onto the gate region of conventional silicon FET devices without gate metal, and current-voltage measurements were performed. Our work showed that the presence of DNA molecules in an aqueous solution on the gate decreased channel current I/sub ds/ and increased threshold voltage. With increasing concentration in the solution, the threshold voltage increased monotonically. We observed that the channel current was reduced systematically during the hybridization of complementary DNA strands. The mechanism that induced the threshold voltage shift is attributed to the negative charges the DNA molecules carry and to changes in work function (Fermi energy). Our results showed the possibility that field effect transistors may provide a vehicle for a label-free, miniaturized and semiconductor-based DNA detector.
Computer-Aided Control System Design Environment

Abstract A computer-aided engineering environment for the design, analysis, and control of mechanical systems is defined and a detailed example is given. The overall integrated environment includes commercially available systems for 3D geometric modeling and animation, multibody system dynamics, finite element analysis, and control system design. The platform for the environment is the Silicon Graphics IRIS Workstation. This environment allows students in mechanical and aeronautical engineering to rapidly develop and test control strategies for mechanical systems. Transfer functions from the multibody system model, together with mathematical models of any electrical, pneumatic, and hydraulic components, are used for control system synthesis. The controller architecture and parameters are specified in block diagram form and converted to a real-time program. This controller program, with any nonmechanical component models included, is combined with the original nonlinear mechanical system model. The dynamic response of this complete system is studied to verify the controller design for this nonlinear, more realistic system model. Once satisfied with the controller design, the student can then download the real-time controller program to a microprocessor for controlling the actual physical plant. This environment will be used in the senior elective/first year graduate course Dynamics and Control of Multibody Systems, developed by the author and offered in the Spring ’91 semester.
Thrombolytic Therapy in Renal Vein Thrombosis

The use of thrombolytic agents to dissolve intravascular thrombi is surging beyond its previous confines. In the mid-1960s, uncontrolled studies in patients with pulmonary embolism were sufficiently impressive for the National Heart, Lung, and Blood Institute to undertake controlled trials. Sharma et al1have recently summarized the two major trials of the 1970s that demonstrated that thrombolytic agents were effective in the short-term and long-term treatment of pulmonary embolism. Studies in deep-venous thrombosis have shown that thrombolytic therapy not only more rapidly resolves thrombi than does heparin sodium in this setting, but it also preserves the integrity of the valves of the involved veins.2The controversy regarding direct perfusion of recently thrombosed coronary arteries with streptokinase in patients with acute myocardial infarction continues, with two recent prospective randomized trials reaching opposite conclusions.3,4 See also p 159. Given the wealth of information indicating that thrombolytic therapy is superior
Effects of Castration Compared With Total Androgen Blockade on Tissue Dihydrotestosterone (DHT) Concentration in Benign Prostatic Hyperplasia (BPH)

We compared the effect of a variety of drug regimens to lower prostate DHT concentration. Patients with BPH were treated for one week prior to surgery with either tamoxifen, flutamide, megestrol acetate, megestrol acetate plus tamoxifen and megestrol acetate plus DES or ketoconazole. DHT concentration in the surgically resected tissue was compared with tissues obtained from untreated patients. We also obtained prostate tissue at the time of relapse in patients with prostate cancer who had been treated with orchiectomy with or without estrogen therapy. Megestrol acetate plus the mini-dose of DES (0.1 mg) and megestrol acetate plus ketoconazole both decreased DHT concentrations in prostate tissue to levels (0.79 ng/g) significantly below those noted with orchiectomy (1.16 ng/g). The difference between the DHT concentration in the two groups (orchiectomy vs. total androgen blockade) represents the contribution of adrenal androgens to prostate tissue DHT. This small amount of DHT (approximately 0.4 ng/g) may be biologically important in stimulating prostate epithelial cell growth.
Fatal Bacterial Endocarditis as a Complication of Permanent Indwelling Catheters. Report of Two Cases

Two cases of endocarditis secondary to permanent indwelling catheters are described. In both cases, the catheters were used for parenteral nutrition and became infected with Staphylococci. Secondary endocarditis developed on the tricuspid and aortic valves. Despite removal of the catheters and appropriate antibiotics, both patients died.
Pheochromocytoma Unmasked by Desipramine Therapy

Excerpt Three previous case reports have described hemodynamic abnormalities precipitated or triggered by imipramine therapy and leading to recognition of pheochromocytoma (1-3). It has been uncert...
How do Independent Directors Influence Corporate Risk-Taking? Evidence from a Quasi-Natural Experiment

Motivated by agency theory, we explore the effect of independent directors on corporate risk taking. To minimize endogeneity, we exploit the passage of the Sarbanes–Oxley Act as an exogenous shock that raises board independence. Our difference-in-difference estimates show that board independence diminishes risk-taking significantly, as evidenced by the substantially lower volatility in the stock returns. In particular, board independence reduces total risk and idiosyncratic risk by 24.87% and 12.60%, respectively. The evidence is consistent with the notion that board independence represents an effective governance mechanism that prevents managers from taking excessive risk. Additional analysis based on propensity score matching also confirms our results. Our research design is based on a natural experiment and is far more likely to show causality, rather than merely an association.
Asymptotics For High Dimensional Regression M-Estimates: Fixed Design Results

We investigate the asymptotic distributions of coordinates of regression M-estimates in the moderate p / n regime, where the number of covariates p grows proportionally with the sample size n. Under appropriate regularity conditions, we establish the coordinate-wise asymptotic normality of regression M-estimates assuming a fixed-design matrix. Our proof is based on the second-order Poincare inequality and leave-one-out analysis. Some relevant examples are indicated to show that our regularity conditions are satisfied by a broad class of design matrices. We also show a counterexample, namely an ANOVA-type design, to emphasize that the technical assumptions are not just artifacts of the proof. Finally, numerical experiments confirm and complement our theoretical results.
Hybrid Rayleigh and Double-Weibull over impaired RF/FSO system with outdated CSI

In this work, we present a global framework of a dual-hop RF/FSO system with multiple relays operating at the mode of amplify-and-forward (AF) with fixed gain. Partial relay selection (PRS) protocol with outdated channel state information (CSI) is assumed since the channels of the first hop are time-varying. The optical irradiance of the second hop are subject to the Double-Weibull model while the RF channels of the first hop experience the Rayleigh fading. The signal reception is achieved either by heterodyne or intensity modulation and direct detection (IM/DD). In addition, we introduce an aggregate model of hardware impairments to the source (S) and the relays since they are not perfect nodes. In order to quantify the impairment impact on the system, we derive closed-form, approximate, upper bound and high signal-to-noise ratio (SNR) asymptotic of the outage probability (OP) and the ergodic capacity (EC). Finally, analytical and numerical results are in agreement using Monte Carlo simulation.
Generalized theory of smallest diameter of metallic nanorods

This paper reports a generalized theory of the smallest diameter of metallic nanorods from physical vapor deposition. The generalization incorporates the effects of nanorod separation and those of van der Waals interactions on geometrical shadowing. The generalized theory relies on approximations to be in closed form. Numerical solutions of governing equations with no approximations verify the accuracy of the closed-form theory. Further, experiments of physical vapor deposition validate the theory in terms of the diameter as a function of the separation of nanorods. In contrast, the previous theory for idealized geometrical shadowing [X. B. Niu et al., Phys. Rev. Lett. 110, 136102 (2013)] excludes any dependence on nanorod separation and predicts the diameter to be about \textonehalf{} to ⅓ of what the generalized theory does.
Bacterial endocarditis of dental origin: report of case

Although appreciated by most practitioners, the fact that dental infection may be the source of bacteremia without a history of recent dental procedures is occasionally overlooked. The case reported here illustrates what we feel is an example of such a phenomenon. The eradication of the oral foci of infection enhanced the patient's response to therapy and prompted his ultimate recovery.
Foundations of the Method of EM Field Separation Into Upgoing And Downgoing Parts And Its Application to MCSEM Data

Abstract The renewed interest in the methods of electromagnetic field decomposition into upgoing and downgoing parts is generated by the practical problem of removing the effect of EM airwaves on marine controlled source electromagnetic data collected in shallow water. In this paper we consider the principles of solving this problem using the classical methods of EM field separation into external and internal parts. We demonstrate that the most general approach to upgoing/downgoing field decomposition is based on the theory of Stratton-Chu type integrals. This approach allows us to separate the field observed on an arbitrary surface. In the case of a flat observational surface, the Stratton-Chu method is equivalent to the decomposition technique based on the Fourier transform in the spatial frequency domain. We present also a novel method of EM field separation using the method of horizontal gradients of the EM field. The new technique is tested on synthetic MCSEM data. The numerical results show that stable and reliable separating results can be obtained using this new approach. We demonstrate also that the method represents a useful tool for a rapid qualitative interpretation of MCSEM data.
Faculty attitudes toward Open Access and scholarly communications: Disciplinary differences on an urban and health science campus

Access to scholarship in the health sciences has greatly increased in the last decade. The adoption of the 2008 U.S. National Institutes of Health Public Access Policy and the launch of successful open access journals in health sciences have done much to move the exchange of scholarship beyond the subscription-only model. One might assume, therefore, that scholars publishing in the health sciences would be more supportive of these changes. However, the results of this survey of attitudes on a campus with a large medical faculty show that health science respondents were uncertain of the value of recent changes in the scholarly communication system.
Diagnostic Imaging and Newer Modalities for Thoracic Diseases: PET/Computed Tomographic Imaging and Endobronchial Ultrasound for Staging and Its Implication for Lung Cancer

Modalities to detect and characterize lung cancer are generally divided into those that are invasive [endobronchial ultrasound (EBUS), esophageal ultrasound (EUS), and electromagnetic navigational bronchoscopy (ENMB)] versus noninvasive [chest radiography (CXR), computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI)]. This chapter describes these modalities, the literature supporting their use, and delineates what tests to use to best evaluate the patient with lung cancer.
Brain Stem Cavernous Malformations: Operative Nuances of a Less-Invasive Resection Technique.

Background Different operative techniques are reported for the resection of brainstem cavernous malformations (BSCMs). The senior author has previously reported on a less-invasive technique of entering the brain stem with piecemeal removal of BSCMs, especially the deep-seated ones. Objective To present a larger series of these lesions, emphasizing the approach to the brain stem via case selection. We discuss the nuances of the less-invasive operative technique through case illustrations and intraoperative videos. Methods A retrospective review of 46 consecutive cases of BSCMs, with their clinical and radiographic data, was performed. Nine cases were selected to illustrate 7 different operative approaches, and discuss surgical nuances of the less-invasive technique unique to each. Results Postoperative morbidity, defined as an increase in modified Rankin Scale, was observed in 5 patients (10.9%). A residual BSCM was present in 2 patients (4.3%); both underwent reoperation to remove the remainder. At follow-up of 31.1 ± 27.8 mo, 3 patients experienced recurrence (6.5%). Overall, 65% of our patients improved, 20% stayed the same, and 11% worsened postsurgery. Two patients died, yielding a mortality of 4.3%. Conclusion Using the less-invasive resection technique for piecemeal BSCM removal, in appropriately selected patients, has yielded comparable to improved patient outcomes over existing large series. In our experience, lateral, anterolateral, and posterolateral approaches are favorable over direct midline (dorsal or ventral) approaches. A thorough understanding of brain-stem safe-entry zones, in conjunction with appropriate approach selection, is key to a good outcome in challenging cases.
Exploring diseases based biomedical document clustering and visualization using self-organizing maps

Document clustering is a text mining technique used to provide better document search and browsing in digital libraries or online corpora. In this research, a vector representation of concepts of diseases and similarity measurement between concepts are proposed. They identify the closest concepts of diseases in the context of a corpus. Each document is represented by using the vector space model. A weight scheme is proposed to consider both local content and associations between concepts. Self-Organizing Maps (SOM) are often used as document clustering algorithm. The vector projection and visualization features of SOM enable visualization and analysis of the cluster distribution and relationships on the two dimensional space. The Davies-Bouldin index is used to validate the clusters based on the visualized cluster distributions. The results show that the proposed document clustering framework generates meaningful clusters and can facilitate clustering visualization and information retrieval based on the concepts of diseases.
Debt Traps? Market Vendors and Moneylender Debt in India and the Philippines

A debt trap occurs when someone takes on a high-interest rate loan and is barely able to pay back the interest, and thus perpetually finds themselves in debt (often by re-financing). Studying such practices is important for understanding financial decision-making of households in dire circumstances, and also for setting appropriate consumer protection policies. We conduct a simple experiment in three sites in which we paid off high-interest moneylender debt of individuals. Most borrowers returned to debt within six weeks. One to two years .after intervention, treatment individuals were borrowing at the same rate as control households.
Salience Bias in Crowdsourcing Contests

Crowdsourcing relies on online platforms to connect a community of users to perform specific tasks. However, without appropriate control, the behavior of the online community might not align with t...
Coded Caching Schemes With Reduced Subpacketization From Linear Block Codes

Coded caching is a technique that generalizes conventional caching and promises significant reductions in traffic over caching networks. However, the basic coded caching scheme requires that each file hosted in the server be partitioned into a large number (i.e., the subpacketization level) of non-overlapping subfiles. From a practical perspective, this is problematic as it means that prior schemes are only applicable when the size of the files is extremely large. In this paper, we propose coded caching schemes based on combinatorial structures called resolvable designs. These structures can be obtained in a natural manner from linear block codes whose generator matrices possess certain rank properties. We obtain several schemes with subpacketization levels substantially lower than the basic scheme at the cost of an increased rate. Depending on the system parameters, our approach allows us to operate at various points on the subpacketization level vs. rate tradeoff.
HIGH SCHOOLS AND STUDENTS' INITIAL COLLEGES AND MAJORS

We use statewide administrative data from Missouri to examine the explanatory power of high schools over student sorting to colleges and majors at 4-year public universities. We develop a “preparation and persistence index” (PPI) for each university-by-major cell in the Missouri system that captures dimensions of selectivity and rigor and allows for a detailed investigation of sorting. Our analysis shows that students’ high schools predict the quality of the initial university, as measured by PPI, conditional on their own academic preparation, and that students from lower-SES high schools systematically enroll at lower-PPI universities. However, high schools offer little explanatory power over major placements within universities.
Provably safe robot navigation with obstacle uncertainty

As drones and autonomous cars become more widespread, it is becoming increasingly important that robots can operate safely under realistic conditions. The noisy information fed into real systems me...
Heterotroph Interactions Alter Prochlorococcus Transcriptome Dynamics during Extended Periods of Darkness

ABSTRACT Microbes evolve within complex ecological communities where biotic interactions impact both individual cells and the environment as a whole. Here we examine how cellular regulation in the marine cyanobacterium Prochlorococcus is influenced by a heterotrophic bacterium, Alteromonas macleodii, under different light conditions. We monitored the transcriptome of Prochlorococcus , grown either alone or in coculture, across a diel light:dark cycle and under the stress of extended darkness—a condition that cells would experience when mixed below the ocean’s euphotic zone. More Prochlorococcus transcripts exhibited 24-h periodic oscillations in coculture than in pure culture, both over the normal diel cycle and after the shift to extended darkness. This demonstrates that biotic interactions, and not just light, can affect timing mechanisms in Prochlorococcus , which lacks a self-sustaining circadian oscillator. The transcriptomes of replicate pure cultures of Prochlorococcus lost their synchrony within 5 h of extended darkness and reflected changes in stress responses and metabolic functions consistent with growth cessation. In contrast, when grown with Alteromonas , replicate Prochlorococcus transcriptomes tracked each other for at least 13 h in the dark and showed signs of continued biosynthetic and metabolic activity. The transcriptome patterns suggest that the heterotroph may be providing energy or essential biosynthetic substrates to Prochlorococcus in the form of organic compounds, sustaining this autotroph when it is deprived of solar energy. Our findings reveal conditions where mixotrophic metabolism may benefit marine cyanobacteria and highlight new impacts of community interactions on basic Prochlorococcus cellular processes. IMPORTANCE Prochlorococcus is the most abundant photosynthetic organism on the planet. These cells play a central role in the physiology of surrounding heterotrophs by supplying them with fixed organic carbon. It is becoming increasingly clear, however, that interactions with heterotrophs can affect autotrophs as well. Here we show that such interactions have a marked impact on the response of Prochlorococcus to the stress of extended periods of darkness, as reflected in transcriptional dynamics. These data suggest that diel transcriptional rhythms within Prochlorococcus , which are generally considered to be strictly under the control of light quantity, quality, and timing, can also be influenced by biotic interactions. Together, these findings provide new insights into the importance of microbial interactions on Prochlorococcus physiology and reveal conditions where heterotroph-derived compounds may support autotrophs—contrary to the canonical autotroph-to-heterotroph trophic paradigm.
Mitigation of Policy Manipulation Attacks on Deep Q-Networks with Parameter-Space Noise

Recent developments establish the vulnerability of deep reinforcement learning to policy manipulation attack. In this work, we propose a technique for mitigation of such attacks based on addition of noise to the parameter space of deep reinforcement learners during training. We experimentally verify the effect of parameter-space noise in reducing the transferability of adversarial examples, and demonstrate the promising performance of this technique in mitigating the impact of whitebox and blackbox attacks at both test and training times.
Supporting answerers with feedback in social Q&A

Prior research has examined the use of Social Question and Answer (Q&A) websites for answer and help seeking. However, the potential for these websites to support domain learning has not yet been realized. Helping users write effective answers can be beneficial for subject area learning for both answerers and the recipients of answers. In this study, we examine the utility of crowdsourced, criteria-based feedback for answerers on a student-centered Q&A website, Brainly.com. In an experiment with 55 users, we compared perceptions of the current rating system against two feedback designs with explicit criteria (Appropriate, Understandable, and Generalizable). Contrary to our hypotheses, answerers disagreed with and rejected the criteria-based feedback. Although the criteria aligned with answerers' goals, and crowdsourced ratings were found to be objectively accurate, the norms and expectations for answers on Brainly conflicted with our design. We conclude with implications for the design of feedback in social Q&A.
Quantifying the Impact of Cognitive Biases in Question-Answering Systems.

Crowdsourcing can identify high-quality solutions to problems; however, individual decisions are constrained by cognitive biases. We investigate some of these biases in an experimental model of a question-answering system. In both natural and controlled experiments, we observe a strong position bias in favor of answers appearing earlier in a list of choices. This effect is enhanced by three cognitive factors: the attention an answer receives, its perceived popularity, and cognitive load, measured by the number of choices a user has to process. While separately weak, these effects synergistically amplify position bias and decouple user choices of best answers from their intrinsic quality. We end our paper by discussing the novel ways we can apply these findings to substantially improve how high-quality answers are found in question-answering systems.
Dynamic Exchange of Two Essential DNA Polymerases during Replication and after Fork Arrest.

Abstract The replisome is a multiprotein machine responsible for the faithful replication of chromosomal and plasmid DNA. Using single-molecule super-resolution imaging, we characterized the dynamics of three replisomal proteins in live Bacillus subtilis cells: the two replicative DNA polymerases, PolC and DnaE, and a processivity clamp loader subunit, DnaX. We quantified the protein mobility and dwell times during normal replication and following replication fork stress using damage-independent and damage-dependent conditions. With these results, we report the dynamic and cooperative process of DNA replication based on changes in the measured diffusion coefficients and dwell times. These experiments show that the replication proteins are all highly dynamic and that the exchange rate depends on whether DNA synthesis is active or arrested. Our results also suggest coupling between PolC and DnaX in the DNA replication process and indicate that DnaX provides an important role in synthesis during repair. Furthermore, our results suggest that DnaE provides a limited contribution to chromosomal replication and repair in vivo.
SPARSE TENSOR RECOVERY VIA N-MODE FISTA WITH SUPPORT AUGMENTATION

A common approach for performing sparse tensor recovery is to use an N-mode FISTA method. However, this approach may fail in some cases by missing some values in the true support of the tensor and compensating by erroneously assigning nearby values to the support. This work proposes a four-stage method for performing sparse tensor reconstruction that addresses a case where N-mode FISTA may fail by augmenting the support set. Moreover, the proposed method preserves a Tucker-like structure throughout computations for computational efficiency. Numerical results on synthetic data demonstrate that the proposed method produces results with similar or higher accuracy than N-mode FISTA, and is often faster.
Evidence for the Feedback Role of Performance Measurement Systems

Performance measurement systems (PMSs) are used to diagnose and remediate problems, termed the “decision-facilitating” or feedback role of management control. We examine whether use of PMSs by indi...