cssi/SciSciGPT-SciSciNet huggingface dataset:
Assessing the Impacts of Time-to-Detection Distribution Assumptions on Detection Probability Estimation

Abundance estimates from animal point-count surveys require accurate estimates of detection probabilities. The standard model for estimating detection from removal-sampled point-count surveys assumes that organisms at a survey site are detected at a constant rate; however, this assumption can often lead to biased estimates. We consider a class of N-mixture models that allows for detection heterogeneity over time through a flexibly defined time-to-detection distribution (TTDD) and allows for fixed and random effects for both abundance and detection. Our model is thus a combination of survival time-to-event analysis with unknown-N, unknown-p abundance estimation. We specifically explore two-parameter families of TTDDs, e.g., gamma, that can additionally include a mixture component to model increased probability of detection in the initial observation period. Based on simulation analyses, we find that modeling a TTDD by using a two-parameter family is necessary when data have a chance of arising from a distribution of this nature. In addition, models with a mixture component can outperform non-mixture models even when the truth is non-mixture. Finally, we analyze an Ovenbird data set from the Chippewa National Forest using mixed effect models for both abundance and detection. We demonstrate that the effects of explanatory variables on abundance and detection are consistent across mixture TTDDs but that flexible TTDDs result in lower estimated probabilities of detection and therefore higher estimates of abundance. Supplementary materials accompanying this paper appear on-line.
Regulation-Induced Pollution Substitution

Environmental regulations may cause firms to reoptimize over pollution inputs. By regulating air emissions in particular counties, the Clean Air Act (CAA) gives firms incentives to substitute towar...
Intragenic CFTR Duplication and 5T/12TG Variant in a Patient with Non-Classic Cystic Fibrosis

Cystic fibrosis (CF) is an autosomal recessive disorder characterized by the accumulation of sticky and heavy mucus that can damage several organs. CF shows variable expressivity in affected individuals, but it typically causes respiratory and digestive complications as well as congenital bilateral absence of the vas deferens in males. Individuals with classic CF usually have variants that produce a defective protein from both alleles of the CFTR gene. Individuals with other variants may present with classic, non-classic, or milder forms of CF due to lower levels of functional CFTR protein. This article reports the genetic analysis of a female with features of asthma and mild or non-classic CF. CFTR sequencing demonstrated that she is a carrier for a maternally derived 5T/12TG variant. Deletion/duplication analysis by multiplex ligation-dependent probe amplification (MLPA) showed the presence of an intragenic paternally derived duplication involving exons 7–11 of the CFTR gene. This duplication is predicted to result in the production of a truncated CFTR protein lacking the terminal part of the nucleotide-binding domain 1 (NBD1) and thus is likely to be a non-functioning allele. The combination of this large intragenic duplication and 5T/12TG is the probable cause of the mild or non-classic CF features in this individual.
Effects of bunch density gradient in high-gain free-electron lasers☆

The authors investigate effects of the bunch density gradient in self-amplified spontaneous emission (SASE), including the role of coherent spontaneous emission (CSE) in the evolution of the free-electron laser (FEL) process. In the exponential gain regime, the authors solve the coupled Maxwell-Vlasov equations and extend the linear theory to a bunched beam with energy spread. A time-dependent, nonlinear simulation algorithm is used to study the CSE effect and the nonlinear evolution of the radiation pulse.
Understanding the Shift in Demand for Cash Value Life Insurance

Ownership of cash value life insurance in the United States has fallen in recent decades. Changes in age cohorts, family composition, and tax laws may have contributed to this decline. We identify factors that influence the demand for cash value life insurance and test whether they alone can explain the sharp decline in ownership. Demographic and tax code changes do not explain the decrease in permanent insurance. There is a consistent downward trend in demand from 1992 to 2010—particularly among middle-age and younger households. The fewer households who own cash value policies are on average wealthier and more financially sophisticated, suggesting that permanent life insurance is increasingly being used as a tax shield rather than as a hedge against a loss in human capital.
'Acting Wife': Marriage Market Incentives and Labor Market Investments

Do single women avoid career-enhancing actions because these actions signal undesirable traits, like ambition, to the marriage market? While married and unmarried female MBA students perform similarly when their performance is unobserved by classmates (on exams and problem sets), unmarried women have lower participation grades. In a field experiment, single female students reported lower desired salaries and willingness to travel and work long hours on a real-stakes placement questionnaire when they expected their classmates to see their preferences. Other groups' responses were unaffected by peer observability. A second experiment indicates the effects are driven by observability by single male peers.
Grothendieck groups of categories of abelian varieties

We compute the Grothendieck group of the category of abelian varieties over an algebraically closed field k. We also compute the Grothendieck group of the category of A-isotypic abelian varieties, for any simple abelian variety A, assuming k has characteristic 0, and for any elliptic curve A in any characteristic.
Measuring the Effects of Federal Reserve Forward Guidance and Asset Purchases on Financial Markets

I extend the methods of Gurkaynak, Sack, and Swanson (2005) to separately identify the effects of Federal Reserve forward guidance and large-scale asset purchases (LSAPs) during the 2009–15 U.S. zero lower bound (ZLB) period. I find that both forward guidance and LSAPs had substantial and highly statistically significant effects on medium-term Treasury yields, stock prices, and exchange rates, comparable in magnitude to the effects of the federal funds rate before the ZLB. Forward guidance was more effective than LSAPs at moving short-term Treasury yields, while LSAPs were more effective than forward guidance and the federal funds rate at moving longer-term Treasury yields, corporate bond yields, and interest rate uncertainty. However, the effects of forward guidance were not very persistent, with a half-life of 1–4 months. The effects of LSAPs seem to be more persistent. I conclude that, overall in terms of these criteria, LSAPs were a more effective policy tool than forward guidance during the ZLB period.
Masters of Disasters? An Empirical Analysis of How Societies Benefit from Corporate Disaster Aid

Corporations are increasingly influential within societies worldwide, while the relative capacity of national governments to meet large social needs has waned. Consequentially, firms face social pr...
Sparse-TDA: Sparse Realization of Topological Data Analysis for Multi-Way Classification

Topological data analysis (TDA) has emerged as one of the most promising techniques to reconstruct the unknown shapes of high-dimensional spaces from observed data samples. TDA, thus, yields key shape descriptors in the form of persistent topological features that can be used for any supervised or unsupervised learning task, including multi-way classification. Sparse sampling, on the other hand, provides a highly efficient technique to reconstruct signals in the spatial-temporal domain from just a few carefully-chosen samples. Here, we present a new method, referred to as the Sparse-TDA algorithm, that combines favorable aspects of the two techniques. This combination is realized by selecting an optimal set of sparse pixel samples from the persistent features generated by a vector-based TDA algorithm. These sparse samples are selected from a low-rank matrix representation of persistent features using QR pivoting. We show that the Sparse-TDA method demonstrates promising performance on three benchmark problems related to human posture recognition and image texture classification.
DISTAL FEMORAL OSTEOTOMY: UNLOADING THE LATERAL COMPARTMENT

Distal femoral varus osteotomy is a procedure intended to relieve pain, correct valgus deformity, and delay or possibly prevent the progression of lateral compartment osteoarthritis in the knee. It is indicated in patients who are considered too young or are too active to be considered candidates for total knee arthroplasty. It also allows protection of the lateral compartment in cases of meniscal or cartilage allograft. In patients who are a good candidate for total knee replacement, TKR is the procedure of choice. A sloping joint line requires that the correction be performed above the knee. Several methods of distal femoral varus osteotomy have been proposed. These include a medial closing wedge, a lateral opening wedge, and a dome osteotomy. In the author9s experience, the medial closing wedge has proven reliable. This technique uses a 90-degree blade plate, and does not require any angle measurements during surgery. Fixation is secure, allowing early motion. Healing proceeds rapidly in the metaphyseal bone, and non-unions have not occurred. The desired final alignment was zero degrees, which was reliably achieved using this method. Medium to long-term results are generally satisfactory. When conversion to total knee replacement is required, standard components may generally be used, and function was not compromised by the prior osteotomy. Distal femoral varus osteotomy is a successful procedure for lateral compartment osteoarthritis in a valgus knee. It is indicated in patients who are too young or active for total knee arthroplasty, and provides an excellent functional and cosmetic result.
KAWACHI'S INVARIANT FOR NORMAL SURFACE SINGULARITIES

We study a useful numerical invariant of normal surface singularities, introduced recently by T. Kawachi. Using this invariant, we give a quick proof of the (well-known) fact that all log-canonical surface singularities are either elliptic Gorenstein or rational (without assuming a priori that they are ℚ-Gorenstein). In Sec. 2 we prove effective results (stated in terms of Kawachi's invariant) regarding global generation of adjoint linear systems on normal surfaces with boundary. Such results can be used in proving effective estimates for global generation on singular threefolds. The theorem of Ein–Lazarsfeld and Kawamata, which says that the minimal center of log-canonical singularities is always normal, explains why the results proved here are relevant in that situation.
Strategic incentives for innovations and market competition

Abstract We consider a principal–agent model to provide a general analysis of how risk affects incentives of firms who invest in cost-reducing R&D and compete in the product market. We specify the conditions under which higher risk reduces incentives of all firms. We also examine the conditions under which an increase in risk may trigger opposite responses of rivals in the same industry: some firms will strengthen while other firms will weaken the incentives provided to their agents. This result holds regardless of the mode of competition in the product market, Cournot or Bertrand, as long as the rivals’ R&D decisions are strategic substitutes. It can generate new empirical implications and can provide an explanation for the lack of strong empirical support in the literature for a negative relationship between risk and incentives. We also discuss policy implications regarding the effect of risk on the incentives to innovate and welfare.
Visualization of cytoskeletal elements by the atomic force microscope.

Abstract We describe a novel application of atomic force microscopy (AFM) to directly visualize cytoskeletal fibers in human foreskin epithelial cells. The nonionic detergent Triton X-100 in a low concentration was used to remove the membrane, soluble proteins, and organelles from the cell. The remaining cytoskeleton can then be directly visualized in either liquid or air-dried ambient conditions. These two types of scanning provide complimentary information. Scanning in liquid visualizes the surface filaments of the cytoskeleton, whereas scanning in air shows both the surface filaments and the total “volume” of the cytoskeletal fibers. The smallest fibers observed were ca. 50 nm in diameter. The lateral resolution of this technique was ca.20 nm, which can be increased to a single nanometer level by choosing sharper AFM tips. Because the AFM is a true 3D technique, we are able to quantify the observed cytoskeleton by its density and volume. The types of fibers can be identified by their size, similar to electron microscopy.
A narrow-band unfitted finite element method for elliptic PDEs posed on surfaces

The paper studies a method for solving elliptic partial differential equations posed on hypersurfaces in RN , N = 2, 3. The method allows a surface to be given implicitly as a zero level of a level set function. A surface equation is extended to a narrow-band neighborhood of the surface. The resulting extended equation is a non-degenerate PDE and it is solved on a bulk mesh that is unaligned to the surface. An unfitted finite element method is used to discretize extended equations. Error estimates are proved for finite element solutions in the bulk domain and restricted to the surface. The analysis admits finite elements of a higher order and gives sufficient conditions for archiving the optimal convergence order in the energy norm. Several numerical examples illustrate the properties of the method.
Venous Sinus Compromise after Pre-sigmoid, Transpetrosal Approach for Skull Base Tumors: A Study on the Asymptomatic Incidence and Report of a Rare Dural Arteriovenous Fistula as Symptomatic Manifestation

The sigmoid sinus is routinely exposed and manipulated during pre-sigmoid, transpetrosal approaches to the skull base, but there is scant data available on the incidence of venous sinus compromise after surgery. We encountered a dural arteriovenous fistula as a result of sigmoid sinus occlusion and examined the incidence of venous sinus thrombosis or narrowing after transpetrosal surgeries. We performed a retrospective analysis of a series of patients treated by the senior surgeons (WCJ, MH, HJK), who underwent either a posterior petrosectomy or translabyrinthine approach for various skull base tumors. All available clinical and radiographic data were thoroughly examined in each patient to determine the post-operative fate of the venous sinuses. Of the 52 available patients, five patients were discovered post-operatively to have a narrowed or constricted sigmoid sinus ipsilateral to the surgery, whereas another five patients were diagnosed with asymptomatic sinus thrombosis either in the transverse or sigmoid or both. None of these patients experienced symptoms, nor were there any instance of ischemic or hemorrhagic complications. However, there was one additional patient who presented with pulsatile tinnitus 2years after surgery. His angiogram showed an occlusion of the ipsilateral sigmoid sinus and a posterior fossa dural arteriovenous fistula. A two-stage transvenous and transarterial embolization was successful in eliminating the fistula. Technical considerations to avoid sinus injuries during pre-sigmoid, transpetrosal surgery are discussed.
Net-zero settlement in distribution markets

Introduction of market mechanisms in distribution systems is currently subject to extensive studies. One of the challenges facing Distribution Market Operators (DMOs) is to implement a fair and economically efficient pricing mechanism that can incentivize consumers to positively contribute to grid operations and to improve economic performance of the distribution system. This paper studies a penalty-based pricing mechanism in distribution markets and further investigates the interrelationship between the Ideational marginal prices (LMPs) at transmission and distribution levels. As a result, a closed-form relationship between these LMPs is derived. The possibility of zeroing out the settlement profit is further investigated under the proposed pricing mechanism.
Element Abundances in X-ray Emitting Plasmas in Stars

Studies of element abundances in stars are of fundamental interest for their impact in a wide astrophysical context, from our understanding of galactic chemistry and its evolution, to their effect on models of stellar interiors, to the influence of the composition of material in young stellar environments on the planet formation process. We review recent results of studies of abundance properties of X-ray emitting plasmas in stars, ranging from the corona of the Sun and other solar-like stars, to pre-main sequence low-mass stars, and to early-type stars. We discuss the status of our understanding of abundance patterns in stellar X-ray plasmas, and recent advances made possible by accurate diagnostics now accessible thanks to the high resolution X-ray spectroscopy with Chandra and XMM-Newton.
An experimental approach to comparing similarity- and guilt-based charitable appeals

Abstract Non-profit organizations face the challenge of eliciting pro-social behavior (e.g., donations) amidst an increasingly competitive landscape. This study uses a dictator game experiment with undergraduate students to test how a positive charitable appeal video that highlights similarities between donors and recipients affects donor behavior relative to a traditional guilt appeal video that highlights differences. We find that both feelings of guilt and similarity are positively associated with donation behavior; however, only the guilt-appeal treatment has a statistically significant positive effect on donations relative to the control. Yet, we cannot reject the null hypothesis of equal donations between similarity- and guilt-based treatments. We also find major gender differences in pro-social behavior: average male donations in the control were 40% higher than female donations; whereas, this outcome is almost completely reversed in the guilt appeal treatment, where females donated over twice as much as males. In other words, guilt appeals appear to induce women's pro-social behavior but have the opposite effect on men. This difference may be partially explained by males’ aversion to feelings of manipulation, which seemed to discourage their donations but had no impact on female donations.
Fitting the linear preferential attachment model

Preferential attachment is an appealing mechanism for modeling power-law behavior of the degree distributions in directed social networks. In this paper, we consider methods for fitting a 5-parameter linear preferential model to network data under two data scenarios. In the case where full history of the network formation is given, we derive the maximum likelihood estimator of the parameters and show that it is strongly consistent and asymptotically normal. In the case where only a single-time snapshot of the network is available, we propose an estimation method which combines method of moments with an approximation to the likelihood. The resulting estimator is also strongly consistent and performs quite well compared to the MLE estimator. We illustrate both estimation procedures through simulated data and explore the usage of this model in a real data example.
Integrating Rules and Ontologies in the First-Order Stable Model Semantics (Preliminary Report)

We present an approach to integrating rules and ontologies on the basis of the first-order stable model semantics proposed by Ferraris, Lee and Lifschitz. We show that some existing integration proposals can be uniformly reformulated in terms of the first-order stable model semantics. The reformulations are simpler than the original proposals in the sense that they do not refer to grounding.
Unusual Change in Columnar Defect Morphology in YBCO upon Annealing

We show evidence from transmission electron microscopy of an unusual change in columnar defect morphology in YBCO upon annealing to 600°C. The disappearance of the nanotwinned, but not the larger scaled thermal twinned, structure is found. A removal of the large fluctuations in the diameter of the amorphous column, preserving a narrow continuous column, is surprisingly discovered. Correlations with magnetization measurements demonstrate the greater efficiency of vortex pinning at 77 K by the annealed defect structure.
Wound-induced Ca2+ wave propagates through a simple release and diffusion mechanism

Damage-associated molecular patterns (DAMPs) are critical mediators of information concerning tissue damage from damaged cells to neighboring healthy cells. ATP acts as an effective DAMP when released into extracellular space from damaged cells. Extracellular ATP receptors monitor tissue damage and activate a Ca2+ wave in the surrounding healthy cells. How the Ca2+ wave propagates through cells after a wound is unclear. Ca2+ wave activation can occur extracellularly via external receptors or intracellularly through GAP junctions. Three potential mechanisms to propagate the Ca2+ wave are source and sink, amplifying wave, and release and diffusion. Both source and sink and amplifying wave regulate ATP levels using hydrolysis or secretion, respectively, whereas release and diffusion relies on dilution. Here we systematically test these hypotheses using a microfluidics assay to mechanically wound an epithelial monolayer in combination with direct manipulation of ATP hydrolysis and release. We show that a release and diffusion model sufficiently explains Ca2+-wave propagation after an epithelial wound. A release and diffusion model combines the benefits of fast activation at short length scales with a self-limiting response to prevent unnecessary inflammatory responses harmful to the organism.
Initial Experience With an Innovative Pilot Program Evaluating a Multidisciplinary Approach to Supportive Care Planning in a Survivorship Clinic Setting

242 Background: The supportive care and rehabilitative needs of cancer patients are highly varied and complex, and optimal care planning often requires the provision and coordination of multiple modalities. To address these needs, an innovative model for multi-disciplinary evaluation and management within a survivorship clinic was piloted. Methods: Between November 2013 and May 2014, 50 patients who had completed cancer therapy with curative intent were seen in a multi-disciplinary survivorship clinic (MDSC) sequentially by an advanced practice practitioner (nurse practitioner or physician assistant), oncology social worker, and oncology rehabilitation therapist. Data regarding specific care planning resulting from this encounter, compliance with recommended therapies, and patient-reported satisfaction were collected. These data were compared against the remaining cohort of patients (N = 402) who completed curative intent cancer therapy in our cancer program during the same period. Results: Rate of referr...
Hardware emulation of stochastic p-bits for invertible logic

The common feature of nearly all logic and memory devices is that they make use of stable units to represent 0’s and 1’s. A completely different paradigm is based on three-terminal stochastic units which could be called “p-bits”, where the output is a random telegraphic signal continuously fluctuating between 0 and 1 with a tunable mean. p-bits can be interconnected to receive weighted contributions from others in a network, and these weighted contributions can be chosen to not only solve problems of optimization and inference but also to implement precise Boolean functions in an inverted mode. This inverted operation of Boolean gates is particularly striking: They provide inputs consistent to a given output along with unique outputs to a given set of inputs. The existing demonstrations of accurate invertible logic are intriguing, but will these striking properties observed in computer simulations carry over to hardware implementations? This paper uses individual micro controllers to emulate p-bits, and we present results for a 4-bit ripple carry adder with 48 p-bits and a 4-bit multiplier with 46 p-bits working in inverted mode as a factorizer. Our results constitute a first step towards implementing p-bits with nano devices, like stochastic Magnetic Tunnel Junctions.
Nivolumab for patients with recurrent glioblastoma progressing on bevacizumab: a retrospective case series

A single institution retrospective evaluation of nivolumab following disease progression on bevacizumab in adults with recurrent glioblastoma (GBM) with an objective of determining progression free survival (PFS). There is no accepted therapy for recurrent GBM after failure of bevacizumab. 16 adults, ages 52–72 years (median 62), with recurrent GBM were treated. All patients had previously been treated with surgery, concurrent radiotherapy and temozolomide, and post-radiotherapy temozolomide. Bevacizumab (with or without lomustine) was administered to all patients at first recurrence. Patients were treated with nivolumab only (3 mg/kg) once every 2 weeks at second recurrence. One cycle of nivolumab was defined as 2 treatments. Neurological evaluation was performed bi-weekly and neuroradiographic assessment every 4 weeks. A total of 37 treatment cycles (median 2) were administered of nivolumab in which there were 14 Grade 2 adverse events (AEs) and Grade 3 AEs in two patients. No Grade 4 or 5 AEs were seen. Following 1 month of nivolumab, seven patients demonstrated progressive disease and discontinued therapy. No patient demonstrated a response though nine patients demonstrated neuroradiographic stable response. Survival in the entire cohort ranged from 2 to 6 months with a median of 3.5 months (CI 2.8, 4.2). Median and 6-month PFS at 6 months was 2.0 months (range 1–5 months; CI 1.3, 2.7) and 0% respectively. Nivolumab salvage therapy demonstrated no survival advantage in patients with recurrent bevacizumab refractory GBM emphasizing a continued unmet need in neuro-oncology.
CERAMIC-CERAMIC BEARINGS IN PATIENTS < 60 ASSURES LONGEVITY – AFFIRMS

Total hip arthroplasty (THA) is effective, reproducible, and durable in the treatment of hip joint arthritis. While improvements in polyethylene materials have significantly reduced wear rates and osteolysis, aseptic loosening of implants remains one of the leading causes of revision THA. Additionally, fears of dislocation and instability have driven the increase in the utilization of larger diameter femoral heads in primary THA which can lead to increased wear when coupled with a polyethylene articulation. Finally, the increasing number of younger and active patients undergoing THA raises questions with regards to the ability of modern conventional bearings to provide durability and longevity beyond second and third decades following joint implantation. Ceramic-on-ceramic articulations are ideally suited for today9s young and high demand patients undergoing primary THA. It has the lowest in-vitro wear properties of any bearing couple and the wear characteristics further improved by its wettability and lubrication particularly when larger heads are utilised. Additionally, improvements in material properties and prosthesis design have significantly decreased fracture rates and increased the reliability of these implants. Furthermore, reported outcomes and longevity of modern ceramic-on-ceramic THAs in younger patients have all shown excellent survivorship despite patients achieving and maintaining a very high level of activity and function. In short, it is the bearing couple most in tune with current market demands and utilization trends. While registry data and meta-analyses of published literature have failed to show the superiority of ceramic-on-ceramic articulations compared to conventional bearings at 10 years, there is evidence that even highly crosslinked polyethylene (HXPE) is not immune to wear. Selvarajah et al. reported steady, in-vivo wear rates of HXPE exceeding 0.1 mm/year threshold in young THA patients with 36 mm ceramic ball heads. Additionally, small osteolytic lesions have been observed in hips with HXPE bearings at 12–14 years follow up. Finally, analysis of all controlled randomised studies have shown less osteolysis of ceramic-on-ceramic hips compared to polyethylene articulations. The significance of these lesions are unclear but the question remains: Can HXPE as a bearing be able to provide over 30 years of service needed to outlast patients younger than 60 years? Concerns with cost, squeaking, and fractures do not make ceramic-on-ceramic bearings suitable for all patients undergoing primary THA. However, in young, healthy and active patients, a modern ceramic-on-ceramic articulation is most likely to provide the lowest wear rates, lowest risk of osteolysis, and greatest chance for life-long durability.
In vivo structures of an intact type VI secretion system revealed by electron cryotomography

Abstract The type VI secretion system (T6SS) is a versatile molecular weapon used by many bacteria against eukaryotic hosts or prokaryotic competitors. It consists of a cytoplasmic bacteriophage tail‐like structure anchored in the bacterial cell envelope via a cytoplasmic baseplate and a periplasmic membrane complex. Rapid contraction of the sheath in the bacteriophage tail‐like structure propels an inner tube/spike complex through the target cell envelope to deliver effectors. While structures of purified contracted sheath and purified membrane complex have been solved, because sheaths contract upon cell lysis and purification, no structure is available for the extended sheath. Structural information about the baseplate is also lacking. Here, we use electron cryotomography to directly visualize intact T6SS structures inside Myxococcus xanthus cells. Using sub‐tomogram averaging, we resolve the structure of the extended sheath and membrane‐associated components including the baseplate. Moreover, we identify novel extracellular bacteriophage tail fiber‐like antennae. These results provide new structural insights into how the extended sheath prevents premature disassembly and how this sophisticated machine may recognize targets.
Matrix Completion from Noisy Entries

Given a matrix M of low-rank, we consider the problem of reconstructing it from noisy observations of a small, random subset of its entries. The problem arises in a variety of applications, from collaborative filtering (the 'Netflix problem') to structure-from-motion and positioning. We study a low complexity algorithm introduced by Keshavan, Montanari, and Oh (2010), based on a combination of spectral techniques and manifold optimization, that we call here OPTSPACE. We prove performance guarantees that are order-optimal in a number of circumstances.
CLASSROOM DIVERSITY AND ACADEMIC OUTCOMES

This paper tests how the race and ethnicity of one's college classmates affect academic performance. Incoming students at a Catholic college are assigned to their first semester, team-taught, required course. Statistical tests support that this assignment is uncorrelated with a variety of student characteristics. Controlling for team fixed effects and student characteristics, I find evidence of racial peer effects that differ for white students and students of color. White students earn higher grades in classes with more students of color. Students of color with more nonwhite classmates earn lower grades; these effects occur exclusively among those with lower SAT scores. (JEL I21, I28)
Gyrokinetic continuum simulation of turbulence in a straight open-field-line plasma

Five-dimensional gyrokinetic continuum simulations of electrostatic plasma turbulence in a straight, open-field-line geometry have been performed using a full- discontinuous-Galerkin approach implemented in the Gkeyll code. While various simplifications have been used for now, such as long-wavelength approximations in the gyrokinetic Poisson equation and the Hamiltonian, these simulations include the basic elements of a fusion-device scrape-off layer: localised sources to model plasma outflow from the core, cross-field turbulent transport, parallel flow along magnetic field lines, and parallel losses at the limiter or divertor with sheath-model boundary conditions. The set of sheath-model boundary conditions used in the model allows currents to flow through the walls. In addition to details of the numerical approach, results from numerical simulations of turbulence in the Large Plasma Device, a linear device featuring straight magnetic field lines, are presented.
Gender differences in academic surgery, work-life balance, and satisfaction.

Abstract Background An increasing number of women are pursuing a career in surgery. Concurrently, the percentage of surgeons in dual-profession partnerships is increasing. We sought to evaluate the gender differences in professional advancement, work-life balance, and satisfaction at a large academic center. Materials and methods All surgical trainees and faculty at a single academic medical center were surveyed. Collected variables included gender, academic rank, marital status, family size, division of household responsibilities, and career satisfaction. Student t-test, Fisher's exact test, and chi-square test were used to compare results. Results There were 127 faculty and 116 trainee respondents (>80% response rate). Respondents were mostly male (77% of faculty, 58% of trainees). Women were more likely than men to be married to a professional (90% versus 37%, for faculty; 82% versus 41% for trainees, P Conclusions Women surgeons are more likely to be partnered with a full-time working spouse and to be primarily responsible for managing their households. Additional consideration for improvement in recruitment and retention strategies for surgeons might address barriers to equalizing these gender disparities.
Equilibria in a Sequential Duopoly Model

Abstract A new class of models of competitive behavior, referred to as stochastic dynamic games, is discussed. It is argued that these models combine certain desirable features of stochastic and dynamic games, in particular allowing for the consideration of intuitively plausible mixed strategies in the context of problems that are best described by means of the state variable formalism. Some advantages of the proposed approach are demonstrated on the example concerned with an output setting duopoly, where the price is subjected to random disturbances and the duopolists do not directly observe each other´s actions. The formulation of this problem as a stochastic sequential game permits one to obtain a new and very interesting class of equilibria, under which periods of price wars are followed by periods of collusive bahavior and vice versa. In addition, the profits earned by the duopolists under these equilibria approach the symmetric Pareto optimal (or cartel) outcome when the variance of price disturbances tends to zero.
A fast algorithm for the coordinate-wise minimum distance estimation

ABSTRACTApplication of the minimum distance (MD) estimation method to the linear regression model for estimating regression parameters is a difficult and time-consuming process due to the complexity of its distance function, and hence, it is computationally expensive. To deal with the computational cost, this paper proposes a fast algorithm which makes the best use of coordinate-wise minimization technique in order to obtain the MD estimator. R package (KoulMde) based on the proposed algorithm and written in Rcpp is available online.
Usage of Specialized Service Delivery: Evidence from Contiguous Counties

This study exploits exogenous policy discontinuities along state borders to estimate the influence of differences in local autonomy on the usage of special districts in U.S. counties. Using forty years of data, this analysis compares counties on either side of state borders where local autonomy differs and finds little to no evidence that negative changes in local autonomy lead to increased utilization of special districts. This study suggests that some prior literature may overstate the importance of local autonomy in local service delivery.
Familial Osteogenic Sarcoma Occurring in Pagetoid Bone

In a father and son who had familial Paget's disease of bone, secondary osteogenic sarcomas involving identical anatomic sites developed at about the same age. A review of the literature revealed 35 additional cases of familial osteogenic sarcoma arising in 14 families, mainly among siblings. The relationship of osteogenic sarcoma to Paget's disease and the familial aspects of both conditions are discussed. This is the first recorded instance of a vertical male-to-male transmission of Paget's disease and osteosarcoma.
Watchful Waiting vs Immediate Transurethral Resection for Symptomatic Prostatism: The Importance of Patients’ Preferences

The rate of resection for benign prostatic hypertrophy shows considerable variability among small geographic areas. To help inform the decision to recommend prostatectomy to men with prostatism without signs of chronic retention, we performed a decision analysis to compare the expected outcomes with immediate transurethral resection and watchful waiting. Data used in the model originated from the medical literature, Medicare claims data, and patient interview studies. In our base-case analysis for 70-year-old men, immediate surgery resulted in the loss of 1.01 months of life expectancy, but when adjustments were made for quality of life, immediate surgery was favored with a net utility benefit of 2.94 quality-adjusted life-months. However, the analysis was particularly sensitive to the degree of disutility attributed to the index symptoms of prostatism. We conclude that patient preferences should be the dominant factor in the decision whether to recommend prostatectomy. (JAMA1988;259:3010-3017)
Fetal Hydronephrosis: Problems in Diagnosis and Management

Experience with the prenatal diagnosis and management of four cases of congenital renal abnormalities is presented. Neither prenatal intervention nor early delivery was indicated in any of these patients. The current enthusiasm for aggressive management of fetal renal abnormalities may underestimate difficulties in prenatal diagnosis and overestimate the potential benefits of early intervention.
IMMEDIATE FIT PROSTHESIS

Abstract The idea of fitting patients with a prosthetic device immediately post-surgically, originated with Berlemont of France in 1958. Weiss of Poland modified Berlemont's work and created worldwide interest in this technique. The technique was first tried in the United States in 1963 at the University of California Medical School in San Francisco and at the U.S. Naval Hospital in Oakland, California. The most important part of the technique is the use of a rigid plaster of paris dressing. The dressing, when properly applied, reduces edema of the stump, and in limbs with impaired circulation the dressing promotes healing of the wound.
The Political Ecology of Plantations from the Ground Up

Little work has been done to examine the political ecology and environmental legacy of sugar colonies in the Caribbean. Material excavated from the Morne Patate plantation in southern Dominica occu...
Lateral Bracing Of Columns And Beams

Simple and elementary method is developed which permits one to calculate lower limits of strength and rigidity of lateral support in order to provide full bracing to columns and beams; full bracing is defined as equivalent in effectiveness to immovable lateral support.
Rad GTPase is essential for the regulation of bone density and bone marrow adipose tissue in mice

Abstract The small GTP-binding protein Rad ( RRAD , Ras associated with diabetes) is the founding member of the RGK (Rad, Rem, Rem2, and Gem/Kir) family that regulates cardiac voltage-gated Ca 2 + channel function. However, its cellular and physiological functions outside of the heart remain to be elucidated. Here we report that Rad GTPase function is required for normal bone homeostasis in mice, as Rad deletion results in significantly lower bone mass and higher bone marrow adipose tissue (BMAT) levels. Dynamic histomorphometry in vivo and primary calvarial osteoblast assays in vitro demonstrate that bone formation and osteoblast mineralization rates are depressed, while in vitro osteoclast differentiation is increased, in the absence of Rad. Microarray analysis revealed that canonical osteogenic gene expression (Runx2, osterix, etc. ) is not altered in Rad −/− calvarial osteoblasts; instead robust up-regulation of matrix Gla protein (MGP, + 11-fold), an inhibitor of extracellular matrix mineralization and a protein secreted during adipocyte differentiation, was observed. Strikingly, Rad deficiency also resulted in significantly higher marrow adipose tissue levels in vivo and promoted spontaneous in vitro adipogenesis of primary calvarial osteoblasts. Adipogenic differentiation of wildtype calvarial osteoblasts resulted in the loss of endogenous Rad protein, further supporting a role for Rad in the control of BMAT levels. These findings reveal a novel in vivo function for Rad and establish a role for Rad signaling in the complex physiological control of skeletal homeostasis and bone marrow adiposity.
Bank Capital and Loan Monitoring

This paper empirically examines the association between bank capital and banks' monitoring effort. We use four proxies to measure the unobservable monitoring effort. Two of the proxies are based on...
Moralizing to the Choir: The Moral Foundations of American Clergy*

Objective In order to understand the role of clergy in shaping Americans’ moral worldviews, we examine whether the structure of clergy values varies in systematic ways according to contextual factors, such as disagreement in the congregation. Method In early 2014 (February), clergy from a variety of Protestant denominations were contacted by email and invited to complete a survey online, which included a 20-item moral foundations (MFs) battery as well as a variety of attitudinal, behavioral, and relational measures. Results Clergy MFs resemble average citizens’, they look to preserve their autonomy by emphasizing individualizing foundations when they are in disagreement with their congregation, and emphasize MFs that align with their religious beliefs, especially their views on religious authority. Conclusion We reject a special religious emphasis on binding foundations. While clergy take moral positions that reflect their theological commitments, we find evidence of contextualizing in how they weight moral positions.
Optimization of total vaporization solid-phase microextraction (TV-SPME) for the determination of lipid profiles of Phormia regina, a forensically important blow fly species

A new method has been developed for the determination of fatty acids, sterols, and other lipids which naturally occur within pupae of the blow fly Phormia regina. The method relies upon liquid extraction in non-polar solvent, followed by derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) w/ 1% trimethylchlorsilane (TMCS) carried out inside the sample vial. The analysis is facilitated by total vaporization solid-phase microextraction (TV-SPME), with gas chromatography-mass spectrometry (GC-MS) serving as the instrumentation for analysis. The TV-SPME delivery technique is approximately a factor of five more sensitive than traditional liquid injection, which may alleviate the need for rotary evaporation, reconstitution, collection of high performance liquid chromatography fractions, and many of the other pre-concentration steps that are commonplace in the current literature. Furthermore, the ability to derivatize the liquid extract in a single easy step while increasing sensitivity represents an improvement over current derivatization methods. The most common lipids identified in fly pupae were various saturated and unsaturated fatty acids ranging from lauric acid (12:0) to arachinoic acid (20:4), as well as cholesterol. The concentrations of myristic acid (14:0), palmitelaidic acid (16:2), and palmitoleic acid (16:1) were the most reliable indicators of the age of the pupae. Graphical abstract Blow fly pupae were extracted prior to emerging as adults. The extracts were analyzed via total vaporization solid-phase microextraction (TV-SPME), revealing a complex mixture of lipids that could be associated with the age of the insect. This information may assist in determining a post-mortum interval (PMI) in a death investigation.
Estimating Aging Effects in Running Events

This paper uses world running records by age to estimate a biological frontier of decline rates. Two models are compared: a linear/ quadratic (LQ) model and a nonparametric model. Two estimation me...
Pulsed evolution shaped modern vertebrate body sizes.

The relative importance of different modes of evolution in shaping phenotypic diversity remains a hotly debated question. Fossil data suggest that stasis may be a common mode of evolution, while modern data suggest some lineages experience very fast rates of evolution. One way to reconcile these observations is to imagine that evolution proceeds in pulses, rather than in increments, on geological timescales. To test this hypothesis, we developed a maximum-likelihood framework for fitting Levy processes to comparative morphological data. This class of stochastic processes includes both an incremental and a pulsed component. We found that a plurality of modern vertebrate clades examined are best fitted by pulsed processes over models of incremental change, stationarity, and adaptive radiation. When we compare our results to theoretical expectations of the rate and speed of regime shifts for models that detail fitness landscape dynamics, we find that our quantitative results are broadly compatible with both microevolutionary models and observations from the fossil record.
The interplay between activity and filament flexibility determines the emergent properties of active nematics.

Active nematics are microscopically driven liquid crystals that exhibit dynamical steady states characterized by the creation and annihilation of topological defects. Motivated by differences between previous simulations of active nematics based on rigid rods and experimental realizations based on semiflexible biopolymer filaments, we describe a large-scale simulation study of a particle-based computational model that explicitly incorporates filament semiflexibility. We find that energy injected into the system at the particle scale preferentially excites bend deformations, reducing the apparent filament bend modulus. The emergent characteristics of the active nematic depend on activity and flexibility only through this activity-renormalized bend ‘modulus’, demonstrating that apparent values of material parameters, such as the Frank ‘constants’, depend on activity. Thus, phenomenological parameters within continuum hydrodynamic descriptions of active nematics must account for this dependence. Further, we present a systematic way to estimate these parameters from observations of deformation fields and defect shapes in experimental or simulation data.
Value of operational flexibility in co-production systems with yield and demand uncertainty

We study the production decisions of a firm that operates a co-production system (single input but multiple simultaneous outputs) with random yield and demand. The firm uses its outputs to meet mul...
How Well Do Structural Demand Models Work? Counterfactual Predictions in School Choice

Abstract This paper investigates the prediction accuracy of discrete choice models of school demand, using a policy reform in Boston that altered where applicants can apply under school choice. We find that the discrete choice models do not consistently outperform a much simpler heuristic, but their inconsistent performance largely arises from prediction errors in applicant characteristics, which are auxiliary inputs. Once we condition on the correct inputs, the discrete choice models consistently outperform, and their accuracy does not significantly improve upon refitting using post-reform data, suggesting that the choice models capture stable components of the preference distribution across policy regimes.