cssi/SciSciGPT-SciSciNet huggingface dataset:
Unequal Gains: American Growth and Inequality since 1700

List of Illustrations ix Preface xv 1 Persistent Debate, a New Approach, More Data, Rich Findings 1 2 Colonial Incomes on the Eve of the Revolution 13 3 When Did Colonial America Get Rich? 43 4 Losing the Lead: Th e Cost of Revolution and Independence 77 5 Unequal Economic Growth, 1800- 1860 96 6 The Civil War: Growth Lost, Freedom Gained, Inequality Maintained 142 7 Contending Forces: American Incomes across the Late Nineteenth Century 166 8 The Greatest Leveling of All Time 194 9 Rising Inequality Once More, since the 1970s 219 10 Inequality and Growth: History Lessons for the Future 242 Appendix A A Guide to the 1774 and 1800 Income Estimates 263 Appendix B Salaries, Payment in Kind, and Workdays 279 Appendix C Estimating Slaves' Retained Earnings, Colonial Times to 1860 287 Appendix D American versus British Prices, 1640- 1875 304 Appendix E A Guide to the 1860 Income Estimates, and Some Modifications for 1850 311 Appendix F A Guide to the 1870 Income Estimates 320 Appendix G Farm Operators' Incomes in 1870 327 Appendix H Sources and Notes to Tables and Figures in Main Text 349 References 369 Index 391
The Nature of Earthquake Prediction

Earthquake prediction is inherently statistical. Although some people continue to think of earthquake prediction as the specification of the time, place, and magnitude of a future earthquake, it has been clear for at least two decades that this is an unrealistic and unreasonable definition. The reality is that earthquake prediction starts from long-term forecasts of place and magnitude, with very approximate time constraints, and progresses, at least in principle, to a gradual narrowing of the time window as data and understanding permit. The analogy to catching a rabbit in an overgrown confined field may be appropriate. You do not just start out looking for the rabbit, you instead build a fence dividing the field in two and then decide which half the rabbit is in, thereby gaining one bit of information. You iterate this process until you have located the rabbit “close enough for practical purposes.” This is approximately how earthquake prediction proceeds in the real world, with time and position along a fault comprising the two dimensions of the search. (I assume here that we are considering for the moment only large earthquakes, that is those capable of inflicting serious damage on a regional scale; in California this means events of about M 6.7 and larger.) This more realistic perspective on the problem lays to rest the “red herring” that “earthquake predictions might do more harm than earthquakes.” These imaginary concerns are predicated on the fantasy of a prediction that precisely specifies time, place, and magnitude; in the real world a progression of probabilities that narrows the space-time window in small steps clearly carries no such threat. [E]arthquake prediction starts from long-term forecasts of place and magnitude, with very approximate time constraints, and progresses... to a gradual narrowing of the time window as data and understanding permit. In the …
Ascochyta Blight of Chickpeas

Although chickpeas are reported to be susceptible to more than 50 pathogens, few diseases are currently recognized as significant economic constraints to production. Ascochyta blight, caused by the...
An Approximation Algorithm for a Shortest Dubins Path Problem

The problem of finding the shortest path for a vehicle visiting a given sequence of target points subject to the motion constraints of the vehicle is an important problem that arises in several monitoring and surveillance applications involving unmanned aerial vehicles. There is currently no algorithm that can find an optimal solution to this problem. Therefore, heuristics that can find approximate solutions with guarantees on the quality of the solutions are useful. The best approximation algorithm currently available for the case when the distance between any two adjacent target points in the sequence is at least equal to twice the minimum radius of the vehicle has a guarantee of 3.04. This article provides a new approximation algorithm which improves this guarantee to 2.04. The developed algorithm is also implemented for hundreds of typical instances involving at most 30 points to corroborate the performance of the proposed approach.
Dynamic Inefficiency in Decentralized Capital Markets

Abstract We study the efficiency implications of bargaining in frictional capital markets in which firms match bilaterally with dealers in order to buy or sell capital. We show how two of the distinguishing characteristics of capital – ownership and the intertemporal nature of investment – give rise to a dynamic inefficiency. Firms that anticipate buying capital in the future overinvest because this increases their outside option of no trade in negotiations with dealers in the future, thereby lowering the bargained purchase price. Vice versa, firms that anticipate selling capital in the future strategically underinvest because this increases the bargained sale price. If the only motive for trade is capital depreciation, there is overinvestment. With stochastic productivity, high-productivity firms underinvest and low-productivity firms overinvest. In equilibrium, the inefficiency interacts with the externality from dealer entry and implies that no bargaining power achieves the constrained–efficient allocation. We propose a regressive tax on capital that can restore efficiency. Finally, we calibrate the model to data on physical capital markets and show that depending on bargaining power, the welfare loss from the inefficiency can be large.
Changing Topographic Patterns of Human Cerebral Blood Flow with Age Measured by Xenon CT

Changes in cerebral blood flow with age have been of long-standing interest. A study of 20 normal, healthy, right-handed volunteers 20–100 years old using a noninvasive method is reported. Local cerebral blood flow (LCBF) and partition coefficients (Lλ) were measured during inhalation of 35% stable xenon gas and serial computed tomographic (CT) scanning (CT-CBF). Throughout CT-CBF measurements, subjects lay comfortably at rest, with eyes closed and ears unplugged. Environmental stimulation was limited to ambient light and only those sounds unavoidable during CT scanning. LCBF values were correlated with advancing age by cross-sectional analysis. Relatively higher LCBF values were measured bilaterally in the cortex of occipital and frontal lobes; no significant differences were noted between left and right hemispheres. Significant age-related declines in LCBF values were observed for all cortical and subcortical gray and white matter regions of interest examined ( p < 0.001 for all three regions). Age-related declines were steepest in the cortex of the frontal lobes, particularly prefrontal cortex, caudate, putamen, and lentiform nuclei. Speech and visual cortical regions, functionally active throughout the normal life span, showed less age-related decline compared with all other regions, particularly prefrontal. So-called “hyperfrontality,” ratio of mean flow values for frontal cortex to mean pooled values for total cortex, became progressively reduced with age ( p < 0.01).
Launch Decisions of Pharmaceutical Companies

This paper models the launch decision of pharmaceutical companies in regard to new drugs and country markets. New drugs are launched with a delay or not launched at all in many countries. Considering that many of these new drugs would have created health benefits to the patients, there seems to be welfare loss. We use market characteristics to explain this phenomenon. We show that most of the estimated launch with a delay and no-launch decision is due to observable market characteristics. The model has an accuracy of 70 percent in explaining the no-launch decision. Intellectual property rights protection is especially important. The policy implication is that stronger property rights increase the likelihood and speed of new drug launch.
The radial speed‐expansion speed relation for Earth‐directed CMEs

Earth-directed coronal mass ejections (CMEs) are the main drivers of major geomagnetic storms. Therefore, a good estimate of the disturbance arrival time at Earth is required for space weather predictions. The STEREO and SOHO spacecraft were viewing the Sun in near quadrature during January 2010 to September 2012, providing a unique opportunity to study the radial speed (V (sub rad)) to expansion speed(V (sub exp)) relationship of Earth-directed CMEs. This relationship is useful in estimating the V (sub rad) of Earth-directed CMEs, when they are observed from Earth view only. We selected 19 Earth-directed CMEs observed by the Large Angle and Spectrometric Coronagraph (LASCO)/C3 coronagraph on SOHO and the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)/COR2 coronagraph on STEREO during January 2010 to September 2012. We found that of the three tested geometric CME models the full ice-cream cone model of the CME describes best the V (sub rad) to V (sub exp) relationship, as suggested by earlier investigations. We also tested the prediction accuracy of the empirical shock arrival (ESA) model proposed by Gopalswamy et al.(2005a), while estimating the CME propagation speeds from the CME expansion speeds. If we use STEREO observations to estimate the CME width required to calculate the V (sub rad) from the V (sub exp) measurements, the mean absolute error (MAE) of the shock arrival times of the ESA model is 8.4 hours. If the LASCO measurements are used to estimate the CME width, the MAE still remains below 17 hours. Therefore, by using the simple V (sub rad) to V (sub exp) relationship to estimate the V (sub rad) of the Earth-directed CMEs, the ESA model is able to predict the shock arrival times with accuracy comparable to most other more complex models.
A New Family of Regularized Kernels for the Harmonic Oscillator

In this paper, a new two-parameter family of regularized kernels is introduced, suitable for applying high-order time stepping to N-body systems. These high-order kernels are derived by truncating a Taylor expansion of the non-regularized kernel about $$(r^2+\epsilon ^2)$$(r2+∈2), generating a sequence of increasingly more accurate kernels. This paper proves the validity of this two-parameter family of regularized kernels, constructs error estimates, and illustrates the benefits of using high-order kernels through numerical experiments.
A SURGICAL TECHNIQUE TO FACILITATE CR TKA AND PRESERVE PCL FUNCTION

Background Total knee arthroplasty (TKA) is the highly developed procedure for sever osteoarthritic knee, in which there are two major concepts; Cruciate Retaining design (CR) and Posterior Stabilized design (PS). The femoral roll back movement is enforced with the post-cam mechanism in the PS, however, this structure associates with the complications, i.e. wear and dislocation. The CR has been developed to obtain the knee stability with native posterior cruciate ligament (PCL) in TKA. However, the preservation of the PCL can limit knee exposure and increase the technical challenge of surgery. We hypothesized that the knee exposure was easily achieved after the PCL was released, however, the PCL was repaired and the posterior stability was re-established after the TKA with time if it was released subperiostealy. Objective The objective of this study was to evaluate the varying of the posterior stability after the PCL-released CR TKA. Methods Patients were performed the CR TKA with 3DKnee (DJO Global, Vista, CA), in which the entire PCL was subperiostealy released at its femoral insertion (Fig. 1). Following that, the patients were examined with the Knee Society Score and the KT-2000 knee ligament arthrometer (MedMetric Corp., San Diego, CA) firstly between 3 weeks and 7 weeks and secondly between 12 weeks and 20 weeks postoperatively. Results There were 8 cases in 2 female and 6 male knees, and the age was 63.3 ± 11.1 (ranging from 51 to 79). Once the PCL was released, the tibia was easy to subluxate, and the knee was clearly exposed intraoperatively. The Knee Society knee score at the first evaluation was 74.4 ± 10.7 (59 to 90), which was significantly improved compared to the preoperative score of 37.0 ± 9.4 (25 to 50) (p We also confirmed the re-establishment of the PCL integrity at a revision TKA, in which the original procedure had been performed 7 years ago (Fig. 2). Conclusion The re-establishment of the posterior stability after the PCL-released CR TKA was demonstrated. This procedure to release the entire PCL subperiostealy is recommended as a means of facilitating CR TKA.
The Causes of the Municipal Solid Waste and the Greenhouse Gas Emissions from the Waste Sector in the United States

Abstract The United State generates the most waste among OECD countries, and there are adverse effects of the waste generation. One of the most serious adverse effects is greenhouse gas, especially CH4, which causes global warming. However, the amount of waste generation is not decreasing, and the United State recycling rate, which could reduce waste generation, is only 26%, which is lower than other OECD countries. Thus, waste generation and greenhouse gas emission should decrease, and in order for that to happen, identifying the causes should be made a priority. The research objective is to verify whether the Environmental Kuznets Curve relationship is supported for waste generation and GDP across the U.S. Moreover, it also confirmed that total waste generation and recycling waste influences carbon dioxide emissions from the waste sector. The annual-based U.S. data from 1990 to 2012 were used. The data were collected from various data sources, and the Granger causality test was applied for identifying the causal relationships. The results showed that there is no causality between GDP and waste generation, but total waste and recycling generation significantly cause positive and negative greenhouse gas emissions from the waste sector, respectively. This implies that the waste generation will not decrease even if GDP increases. And, if waste generation decreases or recycling rate increases, the greenhouse gas emission will decrease. Based on these results, it is expected that the waste generation and carbon dioxide emission from the waste sector can decrease more efficiently.
2015 James W. Freston Single Topic Conference: A Renaissance in the Understanding and Management of Irritable Bowel Syndrome

Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA, Los Angeles, California; Department of Biobehavioral Nursing & Health Systems, School of Nursing, Division of Gastroenterology, School of Medicine, University of Washington, Seattle, Washington; Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan; Department of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
An Examination of the Predictive Relationship Between Mode of Instruction and Student Success in Introductory Biology

Community colleges continue to increase online course offerings as these institutions strive to offer open access, cost effective education to a growing student population. With an increased student demand for online learning, community colleges should explore the possibility of offering all courses in the online environment, including science courses. The purpose of this quantitative research was to investigate the success of non-science major students in biology 102 on campus comparing students who completed biology 101 online to students who completed biology 101 on campus within Virginia community colleges. This was the first multi institutional, multi semester study of community college online biology and the first investigation to look at potential relationships between student success and student demographic characteristics, filling several gaps within the professional literature. Ex post facto data were collected from the Virginia Community College System and analyzed through binary logistic regression. Mode of instruction in biology 101 was not predictive of student success in biology 102 on campus. Mode of instruction did not significantly impact the predictive relationship between student demographic characteristics and student success except for student gender. Male students who completed biology 101 online were significantly less likely to be successful in biology 102 on campus. Overall, the findings indicate that online biology is a viable option for community colleges to effectively serve a diverse student population. As emerging research, this study provides a baseline of student success within online biology and offers suggestions as to gaps remaining within the literature that can be investigated in future research.
Antibody and cellular immune responses of naïve mares to repeated vaccination with an inactivated equine herpesvirus vaccine

Equine herpesvirus type 1 (EHV-1) continues to cause severe outbreaks of abortions or myeloencephalopathy in horses despite widely used vaccination. The aim of this work was to determine the effects of frequent vaccination with an inactivated EHV vaccine on immune development in horses. Fifteen EHV-1 naive mares were vaccinated a total of 5 times over a period of 8 months with intervals of 20, 60, 90 and 60 days between vaccine administrations. Total antibody and antibody isotype responses were evaluated with a new sensitive EHV-1 Multiplex assay to glycoprotein C (gC) and gD for up to 14 months after initial vaccination. Antibodies peaked after the first two vaccine doses and then declined despite a third administration of the vaccine. The fourth vaccine dose was given at 6 months and the gC and gD antibody titers increased again. Mixed responses with increasing gC but decreasing gD antibody values were observed after the fifth vaccination at 8 months. IgG4/7 isotype responses mimicked the total Ig antibody production to vaccination most closely. Vaccination also induced short-lasting IgG1 antibodies to gC, but not to gD. EHV-1-specific cellular immunity induced by vaccination developed slower than antibodies, was dominated by IFN-γ producing T-helper 1 (Th1) cells, and was significantly increased compared to pre-vaccination values after administration of 3 vaccine doses. Decreased IFN-γ production and reduced Th1-cell induction were also observed after the second and fourth vaccination. Overall, repeated EHV vaccine administration did not always result in increasing immunity. The adverse effects on antibody and cellular immunity that were observed here when the EHV vaccine was given in short intervals might in part explain why EHV-1 outbreaks are observed worldwide despite widely used vaccination. The findings warrant further evaluation of immune responses to EHV vaccines to optimize vaccination protocols for different vaccines and horse groups at risk.
Social Inclusion in macro-level diagnostics : reflecting on the World Bank Group's early systematic country diagnostics

The idea of social inclusion has garnered considerable attention, especially in the context of two recent developments: the Sustainable Development Goals and the heightened attention to inequality. This paper reviews the manner and extent to which social inclusion is addressed in the first 17 Systematic Country Diagnostics (SCDs), which are ex ante, country-level assessments conducted by the World Bank Group, ahead of the preparation of its Country Partnership Frameworks. In addition to this primary purpose, the paper fulfils three other purposes. It allows for a broader reflection on the value of the social inclusion construct in macro-level diagnostics; it takes the opportunity to develop and refine a methodology to assess social inclusion and finally, it positions the narrative on social inclusion into the ongoing discourse on poverty, shared prosperity, inequality and the thinking around the implementation of the Sustainable Development Goals. It is therefore, a refined articulation of the idea of social inclusion in the context of global epistemological shifts
Basis Function Models for Animal Movement

ABSTRACTAdvances in satellite-based data collection techniques have served as a catalyst for new statistical methodology to analyze these data. In wildlife ecological studies, satellite-based data and methodology have provided a wealth of information about animal space use and the investigation of individual-based animal–environment relationships. With the technology for data collection improving dramatically over time, we are left with massive archives of historical animal telemetry data of varying quality. While many contemporary statistical approaches for inferring movement behavior are specified in discrete time, we develop a flexible continuous-time stochastic integral equation framework that is amenable to reduced-rank second-order covariance parameterizations. We demonstrate how the associated first-order basis functions can be constructed to mimic behavioral characteristics in realistic trajectory processes using telemetry data from mule deer and mountain lion individuals in western North America....
In silico assessment of primers for eDNA studies using PrimerTree and application to characterize the biodiversity surrounding the Cuyahoga River

Analysis of environmental DNA (eDNA) enables the detection of species of interest from water and soil samples, typically using species-specific PCR. Here, we describe a method to characterize the biodiversity of a given environment by amplifying eDNA using primer pairs targeting a wide range of taxa and high-throughput sequencing for species identification. We tested this approach on 91 water samples of 40 mL collected along the Cuyahoga River (Ohio, USA). We amplified eDNA using 12 primer pairs targeting mammals, fish, amphibians, birds, bryophytes, arthropods, copepods, plants and several microorganism taxa and sequenced all PCR products simultaneously by high-throughput sequencing. Overall, we identified DNA sequences from 15 species of fish, 17 species of mammals, 8 species of birds, 15 species of arthropods, one turtle and one salamander. Interestingly, in addition to aquatic and semi-aquatic animals, we identified DNA from terrestrial species that live near the Cuyahoga River. We also identified DNA from one Asian carp species invasive to the Great Lakes but that had not been previously reported in the Cuyahoga River. Our study shows that analysis of eDNA extracted from small water samples using wide-range PCR amplification combined with high-throughput sequencing can provide a broad perspective on biological diversity.
Using ESCA and SIMS in composites manufacturing

The surface analysis techniques of electron spectroscopy for chemical analysis (ESCA) and secondary ion mass spectroscopy (SIMS) are shown to be indispensable analytical tools for identifying the chemical composition of bonding surfaces used in fiber-reinforced composites manufacturing. Composite plys are typically handled in clean rooms. Contaminated tabletop surfaces in a clean room can transfer the contaminant to the plys and result in poor composite adhesion. Extruded polyurethane has been used to cover these tabletops. An example of surface analysis is given by examining the surface contamination of an old, used tabletop by different methods and comparing that with the analysis of a new, clean tabletop. ESCA measurements on used tabletop surfaces found these surfaces to be contaminated with polydimethylsiloxane (PDMS) contamination. The presence of PDMS contamination was verified by SIMS analyses. The ESCA and SIMS analysis confirmed polyurethane was the base material and SIMS also detected a phthalate component. Energy dispersive X-ray microanalysis (EDX) and X-ray fluorescence analysis (XRF) were used to determine bulk elemental chemical composition of the polyurethane used in the tabletop. Fourier transform infrared spectroscopy (FTIR) of the polyurethane and of the collected volatile condensable material (CVCM) extracted from the total mass loss (TML) experiment conducted on the polyurethane agreed with the EDX data and showed that the bulk material used in the tabletops did not contain PDMS. The FTIR of the condensate showed that a phthalate plasticizer was also present in the bulk. EDX detected trace Si at extremely low concentrations, relative to the bulk. However, the EDX analysis was not able to establish the functionality of the Si. Thus, XRF, FTIR and TML-CVCM were not sensitive to the surface contaminant that ESCA and SIMS were able to detect. Finally, ESCA experiments conducted on new tabletop material did not detect any PDMS contamination.
Superconducting pairing in resonant inelastic x-ray scattering

We develop a method to study the effect of the superconducting transition on the resonant inelastic x-ray scattering (RIXS) signal in superconductors with an order parameter with an arbitrary symmetry within a quasiparticle approach. As an example, we compare the direct RIXS signal below and above the superconducting transition for $p$-wave-type order parameters. For a $p$-wave order parameter with a nodal line, we show that, counterintuitively, the effect of the gap is most noticeable for momentum transfers in the nodal direction. This phenomenon may be naturally explained as a type of nesting effect.
Feedback matters : evidence from agricultural services

Feedback tools have become ubiquitous in the service industry and social development programs alike. This study designed a field experiment to test whether eliciting feedback can empower users and increase demand for a service. The study randomly assigned different feedback tools in the context of an agricultural service to document their impact on clients' demand and shed light on the underlying mechanisms. The analysis shows large demand effects, in the current and following growing periods. It also documents large demand effect spillovers, as other non-client farmers in the vicinity of treated groups are more likely to sign up for the service. To disentangle pure supply-side monitoring from demand-side accountability effects, additional monitoring was randomly announced to extension workers across treatment and control communities. Extension workers do not exert significantly more effort in villages where additional monitoring takes place. The study concludes that farmers? taste for "respect" leads their higher demand for the service.
Faster Arctic Sea Ice Retreat in CMIP5 than in CMIP3 due to Volcanoes

AbstractThe downward trend in Arctic sea ice extent is one of the most dramatic signals of climate change during recent decades. Comprehensive climate models have struggled to reproduce this trend, typically simulating a slower rate of sea ice retreat than has been observed. However, this bias has been widely noted to have decreased in models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5) compared with the previous generation of models (CMIP3). Here simulations are examined from both CMIP3 and CMIP5. It is found that simulated historical sea ice trends are influenced by volcanic forcing, which was included in all of the CMIP5 models but in only about half of the CMIP3 models. The volcanic forcing causes temporary simulated cooling in the 1980s and 1990s, which contributes to raising the simulated 1979–2013 global-mean surface temperature trends to values substantially larger than observed. It is shown that this warming bias is accompanied by an enhanced rate of Arctic sea ic...
TIAMAT: a tool for interactive analysis of microdata anonymization techniques

Releasing detailed data (microdata) about individuals poses a privacy threat, due to the presence of quasi-identifier (QID) attributes such as age or zip code. Several privacy paradigms have been proposed that preserve privacy by placing constraints on the value of released QIDs. However, in order to enforce these paradigms, data publishers need tools to assist them in selecting a suitable anonymization method and choosing the right system parameters. We developed TIAMAT, a tool for analysis of anonymization techniques which allows data publishers to assess the accuracy and overhead of existing anonymization techniques. The tool performs interactive, head-to-head comparison of anonymization techniques, as well as QID change-impact analysis. Other features include collection of attribute statistics, support for multiple information loss metrics and compatibility with commercial database engines.
Comparability and Cost of Equity Capital

SYNOPSIS: We investigate how the comparability of a company's financial statements is related to its cost of equity capital. The Financial Accounting Standards Board's (FASB 2010) Statement of Financial Accounting Concept No. 8 proposes that comparability is a key tenet of accounting because it allows users of financial statements to benchmark a firm against similar firms when distinguishing between alternative investment opportunities. We provide evidence that greater financial statement comparability is associated with lower cost of equity capital, and show that comparability's effect on cost of equity remains after controlling for within-firm accounting quality. Additionally, we find that investors derive greater benefits from financial statement comparability in firms whose information environments are less transparent (high information asymmetry) and whose equity shares trade in markets that are less competitive (imperfect markets). Our findings contribute to accounting research by providing evidence...
RedThreads: An Interface for Application-Level Fault Detection/Correction Through Adaptive Redundant Multithreading

In the presence of accelerated fault rates, which are projected to be the norm on future exascale systems, it will become increasingly difficult for high-performance computing (HPC) applications to accomplish useful computation. Due to the fault-oblivious nature of current HPC programming paradigms and execution environments, HPC applications are insufficiently equipped to deal with errors. We believe that HPC applications should be enabled with capabilities to actively search for and correct errors in their computations. The redundant multithreading (RMT) approach offers lightweight replicated execution streams of program instructions within the context of a single application process. However, the use of complete redundancy incurs significant overhead to the application performance. In this paper we present RedThreads, an interface that provides application-level fault detection and correction based on RMT, but applies the thread-level redundancy adaptively. We describe the RedThreads syntax and semantics, and the supporting compiler infrastructure and runtime system. Our approach enables application programmers to scope the extent of redundant computation. Additionally, the runtime system permits the use of RMT to be dynamically enabled, or disabled, based on the resiliency needs of the application and the state of the system. Our experimental results demonstrate how adaptive RMT exploits programmer insight and runtime inference to dynamically navigate the trade-off space between an application’s resilience coverage and the associated performance overhead of redundant computation.
Using area health education centers to promote interest in rural practice

Introducton In the USA, area health education centers (AHECs) work to recruit and educate students to serve in medically underserved communities, primary care, and rural settings. One important aspect of their work is connecting students with rural clinical experiences. Within these experiences, AHECs incorporate a community health/socioeconomic experience within the family medicine clerkship that may not be as prevalent in the standard family medicine clerkship experiences. The purpose of the study was to assess the relationship between AHEC-sponsored family medicine clerkships with a self-reported intent to practice in a rural setting upon graduation. Methods The study compared third-year medical students with the Indiana University School of Medicine, which participated in AHEC-sponsored family medicine clerkships to the standard family medicine clerkship. Following the 4-week clerkship, students were asked to report their intent to work in a rural setting using a five-point Likert scale. A χ2 test was used to determine the association of AHEC sponsorship, clerkship site location (rural/urban) and intent to practice in a rural setting. Results The study consisted of 587 students. There was a statistically significant association between self-reported intent and rural clerkship site, χ2 (1, N=587)=6.542, p=0.01. Furthermore, 21.6% (n=25) of students with a rural clerkship experience reported a greater intent compared to 12.3% (n=58) of students with non-rural clerkship experience. Conclusions The study confirmed a significantly positive association between participation in medical clerkship experiences in a rural primary care setting and the intent to practice in a rural setting upon graduation. The results also support the potential value-added benefits through academic-community partnerships with AHECs, family medical and other primary care specialty clerkship programs may perhaps succeed in increasing student interest in pursuing a practice serving in rural communities upon graduation.
SAGITTAL PELVIC TILT DOES NOT CHANGE AFTER UNILATERAL TOTAL HIP REPLACEMENT

Sagittal pelvic tilt (PT) has been shown to effect the functional position of acetabular components in patients with total hip replacements (THR). This change in functional component position may have clinical implications including increased likelihood of wear or dislocation. Surgeons can use computer-assisted navigation intraoperatively to account for a patient9s pelvic tilt and to adjust the position of the acetabular component. However, the accuracy of this technique has been questioned due to the concern that PT may change after THR. The purpose of this study was to measure the change in PT after THR, and to determine if preoperative clinical and radiographic parameters can predict PT changes after THR. 138 consecutive patients who underwent unilateral THR by one surgeon received standing bi-planar lumbar spine and lower extremity radiographs preoperatively and six weeks postoperatively. Patients with prior contralateral THR, conversion THR and instrumented lumbosacral fusions were excluded. PT and pelvic incidence (PI) were measured preoperatively for each patient, and PT was measured on the postoperative imaging. A negative value for PT indicated posterior pelvic tilt. Patient demographics were collected from the chart. Average age was 56.8±10.9 years, average BMI was 28.3±6.0 kg/m2, and 67 patients (48.6%) were female. Mean preoperative pelvic tilt was 0.6°±7.3° (range: −19.0° to 17.9°). We found greater than 10° of sagittal PT in 23 out of 138 (16.6%) patients in this sample. Mean post-operative pelvic tilt was 0.3°±7.4° (range: −18.4° to 15.0°). Mean change in pelvic tilt was −0.3°±3.6° (range: −9.6° to 13.5°). PT changed by less than 5° in 119 of 138 patients (86.2%). The mean difference in pre-operative and post-operative PT is not statistically significant (p = 0.395). Pre-operative PT was strongly correlated with post-operative PT (r2 = 0.88, p = 0.0001) (Figure 1). There was not a statistically significant relationship between PI and change in PT (r2 = −0.16, p = 0.06). In conclusion, based on the variability in pelvic tilt in this study population and the relatively small change in pelvic tilt following THA tilt-adjustment of the acetabular component position based on standing pre-operative imaging is likely to be of benefit in the majority of patients undergoing navigated THA. However, we have been unable to predict the relatively rare occurrence of a large change in pelvic tilt, which would confound tilt-adjusted component position.
Key Attributes of a Modern Statistical Computing Tool

In the 1990s, statisticians began thinking in a principled way about how computation could better support the learning and doing of statistics. Since then, the pace of software development has acce...
Hierarchical Clustering Given Confidence Intervals of Metric Distances

This paper considers metric the exact dissimilarities between pairs of points are not unknown but known to belong to some interval. The goal is to study methods for the determination of hierarchical clusters, i.e., a family of nested partitions indexed by a resolution parameter, induced from the given distance intervals of the dissimilarities. Our construction of hierarchical clustering methods is based on defining admissible methods to be those methods that satisfy the axioms of value—nodes in a metric space with two nodes are clustered together at the convex combination of the upper and lower bounds determined by a parameter—and transformation—when both distance bounds are reduced, the output may become more clustered but not less. Two admissible methods are constructed and are shown to provide universal bounds in the space of admissible methods. Practical implications are explored by clustering moving points via snapshots and by clustering coauthorship networks representing collaboration between researchers from different communities. The proposed clustering methods succeed in identifying underlying hierarchical clustering structures via the maximum and minimum distances in all snapshots, as well as in differentiating collaboration patterns in journal publications between different research communities based on bounds of network distances.
Sparse and low-rank matrix decompositions

We consider the following fundamental problem: given a matrix that is the sum of an unknown sparse matrix and an unknown low-rank matrix, is it possible to exactly recover the two components? Such a capability enables a considerable number of applications, but the goal is both ill-posed and NP-hard in general. In this paper we develop (a) a new uncertainty principle for matrices, and (b) a simple method for exact decomposition based on convex optimization. Our uncertainty principle is a quantification of the notion that a matrix cannot be sparse while having diffuse row/column spaces. It characterizes when the decomposition problem is ill-posed, and forms the basis for our decomposition method and its analysis. We provide deterministic conditions — on the sparse and low-rank components — under which our method guarantees exact recovery.
Applications of Nonlinear Fiber Optics

* The only book describing applications of nonlinear fiber optics * Two new chapters on the latest developments: highly nonlinear fibers and quantum applications* Coverage of biomedical applications* Problems provided at the end of each chapterThe development of new highly nonlinear fibers - referred to as microstructured fibers, holey fibers and photonic crystal fibers - is the next generation technology for all-optical signal processing and biomedical applications. This new edition has been thoroughly updated to incorporate these key technology developments.The book presents sound coverage of the fundamentals of lightwave technology, along with material on pulse compression techniques and rare-earth-doped fiber amplifiers and lasers. The extensively revised chapters include information on fiber-optic communication systems and the ultrafast signal processing techniques that make use of nonlinear phenomena in optical fibers.New material focuses on the applications of highly nonlinear fibers in areas ranging from wavelength laser tuning and nonlinear spectroscopy to biomedical imaging and frequency metrology. Technologies such as quantum cryptography, quantum computing, and quantum communications are also covered in a new chapter.This book will be an ideal reference for: RD scientists involved with research on fiber amplifiers and lasers; graduate students and researchers working in the fields of optical communications and quantum information. * The only book on how to develop nonlinear fiber optic applications* Two new chapters on the latest developments; Highly Nonlinear Fibers and Quantum Applications* Coverage of biomedical applications
An analog front end for full-duplex digital transceivers working on twisted pairs

An analog front-end chip fabricated in a 4- mu m CMOS process has been described. The chip, together with a digital signal processor, implements a full-duplex transceiver for twisted pairs. A fully differential architecture has been used in all the analog signal-processing blocks to get high dynamic range and common-mode noise rejection. The front-end output is a 12-b word generated by a 6- mu s A/D (analog-to-digital) converter with autocalibration, with a linearity better than 1 LSB. >
Evidence for the black hole event horizon

Astronomers have discovered many candidate black holes in X-ray binaries and in the nuclei of galaxies. The candidate objects are too massive to be neutron stars, and for this reason they are considered to be black holes. While the evidence based on mass is certainly strong, there is no proof yet that any of the objects possesses the defining characteristic of a black hole, namely an event horizon. Type I X-ray bursts, which are the result of thermonuclear explosions when gas accretes onto the surface of a compact star, may provide important evidence in this regard. Type I bursts are commonly observed in accreting neutron stars, which have surfaces, but have never been seen in accreting black hole candidates. It is argued that the lack of bursts in black hole candidates is compelling evidence that these objects do not have surfaces. The objects must therefore possess event horizons.
Semiparametric Estimation under Shape Constraints

Abstract Substantial structure and restrictions, such as monotonicity and curvature constraints, necessary to give economic interpretation to empirical findings are often furnished by economic theories. Although such restrictions may be imposed in certain parametric empirical settings in a relatively straightforward fashion, incorporating such restrictions in semiparametric models is often problematic. A solution to this problem is provided via penalized splines, where monotonicity and curvature constraints are maintained through integral transformations of spline basis expansions. Large sample properties, implementation and inferential procedures are presented. Extension to multiple regressions under the framework of additive models is also discussed. A series of Monte Carlo simulations illustrate the finite sample properties of the estimator. The proposed method is employed to estimate a Lorenz curve of income and a production function with multiple inputs.
Can online off-the-shelf lessons improve student outcomes? Evidence from a field experiment

There has been a proliferation of websites that warehouse instructional materials designed to be taught by teachers in a traditional classroom. While this new technology has revolutionized how most teachers plan their lessons, the potential benefits of this innovation are unknown. To present evidence on this, we analyze an experiment in which middle-school math teachers were randomly given access to high-quality “off-the-shelf” lessons. Only providing teachers with online access to the lessons increased students’ math achievement by 0.06 of a standard deviation, but providing teachers with online access to the lessons along with supports to promote their use increased students’ math achievement by 0.09 of a standard deviation. Benefits were much larger for weaker teachers, suggesting that weaker teachers compensated for skill deficiencies by substituting the lessons for their own efforts. Survey evidence suggests that these effects were mediated by both improvements in lesson quality and teachers having more time to engage in other tasks. We rationalize these results with a multitask model of teaching. The intervention is more scalable and cost effective than most policies aimed at improving teacher quality, suggesting a real benefit to making high-quality instructional materials available to teachers on the internet.
Dandelion: Redesigning the Bitcoin Network for Anonymity

Cryptocurrencies are digital currencies that provide cryptographic verification of transactions. In recent years, they have transitioned from an academic research topic to a multi-billion dollar industry. Bitcoin is the best-known example of a cryptocurrency. Cryptocurrencies exhibit two key properties: egalitarianism and transparency. In this context, egalitarianism means that no single party wields disproportionate power over the network's operation. This diffusion of power is achieved by asking other network nodes (e.g., other Bitcoin users) to validate transactions, instead of the traditional method of using a centralized authority for this purpose. Moreover, all transactions and communications are managed over a fully-distributed, peer-to-peer (P2P) network. Cryptocurrencies are transparent in the sense that all transactions are verified and recorded with cryptographic integrity guarantees; this prevents fraudulent activity like double-spending of money. Transparency is achieved through a combination of clever cryptographic protocols and the publication of transactions in a ledger known as a blockchain. This blockchain serves as a public record of every financial transaction in the network. A property that Bitcoin does not provide is anonymity. Each user is identified in the network by a public, cryptographic key. If one were to link such a key to its owner's human identity, the owner's financial history could be partially learned from the public blockchain. In practice, it is possible to link public keys to identities through a number of channels, including the networking protocols on which Bitcoin is built. This is a massive privacy violation, and can be dangerous for deanonymized users.
THE HAPPY TKA PATIENT: IT TAKES A VILLAGE

The goals of any rehabilitation protocol should be to control pain, improve ambulation, maximise range of motion, develop muscle strength, and provide emotional support. Over 85% of TKA patients will recover knee function regardless of which rehabilitation protocol is adopted but the process can be facilitated by proper pain control, physical therapy, and emotional support. The remaining 15% of patients will have difficulty obtaining proper knee function secondary to significant pain, limited preoperative motion, and/or the development of arthrofibrosis. This subset will require a special, individualised rehabilitation program, which may involve prolonged oral analgesia, continued physical therapy, more diagnostic studies and occasionally manipulation. Controlling pain is the mainstay of any treatment plan. The program described herein has been used at Ranawat Orthopaedics over the last 10 years in more than 2000 TKAs.
3D Shape Retrieval via Irrelevance Filtering and Similarity Ranking (IF/SR)

A novel solution for the content-based 3D shape retrieval problem using an unsupervised clustering approach, which does not need any label information of 3D shapes, is presented in this work. The proposed shape retrieval system consists of two modules in cascade: the irrelevance filtering (IF) module and the similarity ranking (SR) module. The IF module attempts to cluster gallery shapes that are similar to each other by examining global and local features simultaneously. However, shapes that are close in the local feature space can be distant in the global feature space, and vice versa. To resolve this issue, we propose a joint cost function that strikes a balance between two distances. Irrelevant samples that are close in the local feature space but distant in the global feature space can be removed in this stage. The remaining gallery samples are ranked in the SR module using the local feature. The superior performance of the proposed IF/SR method is demonstrated by extensive experiments conducted on the popular SHREC12 dataset.