cssi/SciSciGPT-SciSciNet huggingface dataset:
Corporate Risk Disclosure and Audit Fee: A Text Mining Approach

The aim of this study is to introduce an innovative text mining approach to assess firms' risks using unstructured textual disclosure from annual reports. Specifically, we use Natural Language Processing techniques to extract firms' self-identified risks including financial, strategic, operational, and hazard risks based on an enterprise risk management framework. We examine the association between these four risk measures derived from the risk factor section in 10-K filings and audit fees. The results show that audit fees are significantly and positively related to firm-specific financial, strategic, and operational risks, indicating the informativeness of corporate textual risk disclosures. This study provides direct support for the recent US reporting regulatory requirement of adding a new section on risk factors in corporate annual reports.
Akt regulation of glycolysis mediates bioenergetic stability in epithelial cells

Cells use multiple feedback controls to regulate metabolism in response to nutrient and signaling inputs. However, feedback creates the potential for unstable network responses. We examined how concentrations of key metabolites and signaling pathways interact to maintain homeostasis in proliferating human cells, using fluorescent reporters for AMPK activity, Akt activity, and cytosolic NADH/NAD+ redox. Across various conditions, including glycolytic or mitochondrial inhibition or cell proliferation, we observed distinct patterns of AMPK activity, including both stable adaptation and highly dynamic behaviors such as periodic oscillations and irregular fluctuations that indicate a failure to reach a steady state. Fluctuations in AMPK activity, Akt activity, and cytosolic NADH/NAD+ redox state were temporally linked in individual cells adapting to metabolic perturbations. By monitoring single-cell dynamics in each of these contexts, we identified PI3K/Akt regulation of glycolysis as a multifaceted modulator of single-cell metabolic dynamics that is required to maintain metabolic stability in proliferating cells.
The JOBS Act and the Costs of Going Public

We examine the effects of Title I of the Jumpstart Our Business Startups Act for a sample of 312 emerging growth companies (EGCs) that filed for an initial public offering (IPO) from April 5, 2012 through April 30, 2015. We find no reduction in the direct costs of issuance, accounting, legal, or underwriting fees for EGC IPOs. Underpricing, an indirect cost of issuance that increases an issuer's cost of capital, is significantly higher for EGCs compared to other IPOs. More importantly, greater underpricing is present only for larger firms that are newly eligible for scaled disclosure under the Act. Overall, we find little evidence that the Act in its first three years has reduced the measurable costs of going public. Although there are benefits of the Act that issuers appear to value, they should be balanced against the higher costs of capital that can occur after its enactment.
Characterization and reduction of capacitive loss induced by sub-micron Josephson junction fabrication in superconducting qubits

Josephson junctions form the essential non-linearity for almost all superconducting qubits. The junction is formed when two superconducting electrodes come within ∼1 nm of each other. Although the capacitance of these electrodes is a small fraction of the total qubit capacitance, the nearby electric fields are more concentrated in dielectric surfaces and can contribute substantially to the total dissipation. We have developed a technique to experimentally investigate the effect of these electrodes on the quality of superconducting devices. We use λ/4 coplanar waveguide resonators to emulate lumped qubit capacitors. We add a variable number of these electrodes to the capacitive end of these resonators and measure how the additional loss scales with the number of electrodes. We then reduce this loss with fabrication techniques that limit the amount of lossy dielectrics. We then use these techniques for the fabrication of Xmon qubits on a silicon substrate to improve their energy relaxation times by a factor...
Heterogeneous effects of rural electrification: evidence from Bangladesh

Achieving universal access to electricity is one of the most important energy policy goals set by governments in the developing world. The recent empirical literature, however, paints a mixed picture about the economic viability of rural electrification. Although many studies find substantial socioeconomic benefits from rural electrification, others propose that these benefits are overstated. This paper examines the hypothesis that the magnitude and the nature of benefits associated with electrification are highly context dependent. Using a panel data of 7,018 rural households in Bangladesh for 2005 and 2010, the paper explores two underlying determinants of the heterogeneity: the quality of electricity supply and the number of years of being connected to the grid. The analysis uses an instrumental variable and propensity-score-weighed fixed-effects model to address potential endogeneity of electricity adoption. The analysis finds that power outages have a negative impact on almost all development outcomes considered, while some benefits of electrification accrue only over the long run. The overall gain from expanding access to and improving reliability of electricity supply in Bangladesh is estimated to be US$2.3 billion a year.
The Predictability of Analyst Forecast Revisions

The most prevalent forecasts of firms’ long-term earnings issued by analysts are 2-year-ahead earnings per share (EPS) estimates. When introduced by analysts, 2-year-ahead EPS estimates set market expectations for firms’ future earnings. Subsequent revisions to these estimates are highly correlated with contemporaneous changes in stock prices. We examine whether such revisions are sufficiently predictable to enable investors to earn abnormal returns on hedged portfolios. We find that analyst forecast revisions are predictable and document an implementable strategy for investors. Consistent with investors’ fixation on unscaled EPS, the strategy earns positive abnormal returns using unscaled EPS revisions but not when revisions are scaled by the level of the EPS estimate or the stock price. Abnormal returns are found for firms with low analyst coverage, consistent with a greater initial mispricing from analyst optimism for firms with poorer information environments.
Successful Thrombolytic Therapy in Two Patients With Renal Vein Thrombosis

Thrombolytic therapy was administered to two patients with angiographically documented renal vein thrombosis. One patient with bilateral thrombotic disease complicating membranous glomerulonephritis was treated with systemic streptokinase; the second patient had unilateral renal vein thrombosis associated with chronic pyelonephritis and was treated with streptokinase and urokinase administered directly into the involved vessel. Lysis of all thrombus material was demonstrated by follow-up renal venography and was associated with a gratifying improvement of clinical well-being and laboratory function. These cases demonstrate the feasibility of dissolving renal vein thrombi of presumed recent onset and suggest that rapid lysis of the thrombus accelerates functional and clinical recovery.
Selection versus Talent Effects on Firm Value

Abstract Measuring the value of labor-market hires for stock prices, be it underwriters when firms go public (IPOs) or chief executive officers (CEOs), is difficult due to selection. Opaque firms with higher costs of capital benefit more from prestigious underwriters, while productive firms benefit more from talented CEOs. Using assignment models, we show that the importance of talent (or agent heterogeneity) relative to selection (or firm heterogeneity) is measured by wage increases across agents of different compensation ranks divided by changes in output across their firms. The median of this ratio is 0.5% for underwriters and 2% for CEOs.
Immunohistochemical Localization of Glycosphingolipid in Urinary Renal Tubular Cells in Fabry’s Disease

Although the accumulation of neutral glycosphingolipid (GSL), principally globotriaosylceramide ( GbOse3Cer ), in the kidney of patients with Fabry's disease is well documented, little is known about the type and quantity of lipid present in the renal tubular cells shed in the urine. Using a variety of cytologic technics, the authors examined exfoliated cells found in the urine specimens of patients hemizygous and heterozygous for alpha-galactosidase A deficiency. Renal tubular cells contained periodic acid- Shiff positive material that could be identified easily by Papanicolaou stain. A fluorescein-labeled antibody specific for GbOse3Cer localized this lipid to the cytoplasm. Electron microscopy showed numerous electron-dense multilamellar membranous inclusions within phagolysosomes and electronlucent material within lysosomes of tubular cells. Based on immunofluorescence, heterozygote individuals had similar distribution but less quantity of cytoplasmic GSL. The authors conclude that in Fabry's disease GSL accumulates probably in lysosomes of renal tubular cells. These cells are exfoliated and can be identified specifically in voided urine specimens. Examination of renal tubular cells in urine using the fluorescein antibody technic described here affords a noninvasive means of diagnosing and following the effect of therapy in patients with Fabry's disease.
Comparison of the Ileal Conduit and Clean Intermittent Catheterization for Myelomeningocele

Clean intermittent catheterization has been shown to be a safe and effective means of regular vesical emptying in children with neurogenic bladders secondary to myelomeningocele. The major benefits appear to be the protection of the upper urinary tract, and in many children, improved urinary control. In contrast, the ileal conduit has been shown to produce significant long-term complications; the major one is deterioration of the upper urinary tract. Most children with myelomeningocele begin life with normal kidneys. Our goal of therapy, therefore, is a continent independent child with normal renal function. With proper patient selection, clean intermittent catheterization offers an excellent means of achieving this result in many children; the ileal conduit for permanent urinary diversion in children is outmoded.
Complications of Ectopic Ureterocele in Adult Female

Three examples of ectopic ureterocele in adult female were presented. Of these three patients, two had unusual complications: one with a ureterovaginal fistula and the other with neoplastic transformation. Pathologic changes varied from squamous and glandular metaplasia to adenocarcinoma.
Survival Following Orchiectomy for Stage D Adenocarcinoma of the Prostate

The survival of nonprivate and private patients following orchiectomy for stage D adenocarcinoma of the prostate was studied. While the private patients enjoyed a longer survival, their improved survival was found to be a function of an earlier presentation. Examination of the survival statistics with linear regression analysis suggested that survival following orchiectomy is a function of the age at the time of orchiectomy.
Reduction of the Scatter Dose to the Testicle Outside the Radiation Treatment Fields

A technique is described to reduce the dose to the contralateral testicle of patients with testis tumors during retroperitoneal therapy with 10 MV X rays. When a conventional clam-shell shielding device was used, the dose to the testis from the photons scattered by the patient and the collimator jaws was found to be about 1.6% of the prescribed midplane dose. A more substantial gonadal shield made of low melting point Ostalloy, that reduced further the dose from internal scattered X rays, was therefore designed. A 10 cm thick lead scrotal block above the scrotum immediately outside the field is shown to reduce the external scattered radiation to negligible levels. Using the shield and the block, it is possible to reduce the dose to the testicle to one-tenth of one percent of the prescribed midplane dose.
Management of the Newborn With Myelomeningocele: Time for a Decision-Making Process

The relationship between time of surgical intervention and eventual outcome was examined in 110 newborns with myelomeningocele. Numerous earlier reports have cited a significant increase in mortality and morbidity associated with delay of surgery beyond 48 hours. Within the study population of infants, 52 infants (47%) had "early" surgery within the first 48 hours of life, 32 infants (29%) had "delayed" surgery between 3 and 7 days of age, 12 infants (11%) had "late" surgery between 1 week and 10 months of age, and 14 infants (13%) never had surgery by parental decision. Survival rates were similar between those with early, delayed, or late surgery as 92%, 94%, and 100%, respectively, were alive at age 10 months. Also, no significant association existed between time of surgery and development of ventriculitis, developmental delay, or worsening of paralysis. From these observations, it is concluded that there is no urgency in surgical intervention for the initial management of newborns with myelomeningocele. Rather, there is time for comprehensive discussions, counseling, and emotional support for those parents in need of a decision-making process before establishing consent for or against surgical management of their newborn.
AKT isoforms have distinct hippocampal expression and roles in synaptic plasticity

AKT is a kinase regulating numerous cellular processes in the brain, and mutations in AKT are known to affect brain function. AKT is indirectly implicated in synaptic plasticity, but its direct role has not been studied. Moreover, three highly related AKT isoforms are expressed in the brain, but their individual roles are poorly understood. We find in Mus musculus, each AKT isoform has a unique expression pattern in the hippocampus, with AKT1 and AKT3 primarily in neurons but displaying local differences, while AKT2 is in astrocytes. We also find isoform-specific roles for AKT in multiple paradigms of hippocampal synaptic plasticity in area CA1. AKT1, but not AKT2 or AKT3, is required for L-LTP through regulating activity-induced protein synthesis. Interestingly, AKT activity inhibits mGluR-LTD, with overlapping functions for AKT1 and AKT3. In summary, our studies identify distinct expression patterns and roles in synaptic plasticity for AKT isoforms in the hippocampus.
What Works at Work? Toward an Integrative Model Examining Workplace Campaign Strategies

Many US employees are regularly asked to give charitable donations through work. The techniques used to solicit workplace donations vary. Drawing on a nationally representative survey, the study used a sample of donor responses to examine the effectiveness of several widely used campaign strategies: donor choice, company matching, public recognition, and solicitation support. The theoretical framework built on workplace research by Barman (2007) and established charitable giving mechanisms (Bekkers and Wiepking 2011a, 2011b). The research question was, “Do workplace campaign strategies lead employees to participate and to make (larger) donations in the workplace?” The positive outcomes of the strategies, aside from donor choice, were limited, suggesting that tried-and-true workplace fundraising strategies warrant additional scrutiny. The findings are meaningful to campaign managers seeking to identify approaches that generate workplace giving. For researchers, the results confirm growing attention to the importance of purpose-based giving in comparison with community-based giving.
MARKETING STRATEGY AFTER MEETING WALL STREET: THE ROLE OF INFORMATION ASYMMETRY

We relate marketing strategy to the initial public offering (IPO) process during 1980–2010. Pre-IPO marketing intensity provides information to the market, which reduces underpricing and the magnitude of price revisions during the filing period. Firms that experience upward (downward) price revisions spend more (less) on marketing in the five years post-IPO. We confirm that marketing spending is related to a firm's informational environment by finding a positive relation between marketing intensity and firm information transparency post-IPO. This finding indicates that marketing spending is one channel through which a firm affects its perception by the public equity market at issuance and later.
THE TWO-STAGE EXCHANGE, 70% OF THE TIME: TECHNIQUES AND TIMING

There is great debate around how to treat patients with periprosthetic joint infections and there are different techniques utilised throughout the world with large regional differences. In the situation where implants are well fixed there is a potential advantage to retain ingrown implants in which removal would result in severe bone damage. However, there are multiple variables on both the patient side and the surgeon side which can influence the likelihood of success with this approach. In some patients, staged revision of large and well-fixed components will result in bone damage and compromised function, but the two-stage techniques may have great success at long term infection free survivorship. The literature suggests that selective implant retention and joint debridement may be an alternative for those patients who have complex well-fixed components, are not immunocompromised, have not developed sinus formation, and who have less virulent organisms on aspiration. Implant retention techniques should be approached with caution when patients have chronic illness such as diabetes or rheumatoid disease, use immunosuppressive medications, have a negative aspirate for microorganisms, or show any signs of loosening on radiographs or during intra-operative assessment. Like many aspects of patient care, proper patient selection and meticulous surgical techniques are important components to increasing success in these difficult clinical scenarios. This talk will focus on the data currently available in the literature to help participants gain a better understanding of how to individualise treatments for patients with periprosthetic infections.
Motivating the adoption of new community-minded behaviors: An empirical test in Nigeria

Social scientists have long sought to explain why people donate resources for the good of a community. Less attention has been paid to the difficult task of motivating the first adopters of these important behaviors. In a field experiment in Nigeria, we tested two campaigns that encouraged people to try reporting corruption by text message. Psychological theories about how to shift perceived norms and how to reduce barriers to action drove the design of each campaign. The first, a film featuring actors reporting corruption, and the second, a mass text message reducing the effort required to report, caused a total of 1181 people in 106 communities to text, including 241 people who sent concrete corruption reports. Psychological theories of social norms and behavior change can illuminate the early stages of the evolution of cooperation and collective action, when adoption is still relatively rare.
CRISPR/Cas9 cleavages in budding yeast reveal templated insertions and strand-specific insertion/deletion profiles

Harnessing CRISPR-Cas9 technology provides an unprecedented ability to modify genomic loci via DNA double-strand break (DSB) induction and repair. We analyzed nonhomologous end-joining (NHEJ) repair induced by Cas9 in budding yeast and found that the orientation of binding of Cas9 and its guide RNA (gRNA) profoundly influences the pattern of insertion/deletions (indels) at the site of cleavage. A common indel created by Cas9 is a 1-bp (+1) insertion that appears to result from Cas9 creating a 1-nt 5' overhang that is filled in by a DNA polymerase and ligated. The origin of +1 insertions was investigated by using two gRNAs with PAM sequences located on opposite DNA strands but designed to cleave the same sequence. These templated +1 insertions are dependent on the X-family DNA polymerase, Pol4. Deleting Pol4 also eliminated +2 and +3 insertions, which are biased toward homonucleotide insertions. Using inverted PAM sequences, we also found significant differences in overall NHEJ efficiency and repair profiles, suggesting that the binding of the Cas9:gRNA complex influences subsequent NHEJ processing. As with events induced by the site-specific HO endonuclease, CRISPR-Cas9-mediated NHEJ repair depends on the Ku heterodimer and DNA ligase 4. Cas9 events are highly dependent on the Mre11-Rad50-Xrs2 complex, independent of Mre11's nuclease activity. Inspection of the outcomes of a large number of Cas9 cleavage events in mammalian cells reveals a similar templated origin of +1 insertions in human cells, but also a significant frequency of similarly templated +2 insertions.
FEMORAL CEMENTING TECHNIQUES: LEST WE FORGET

In North America, cementless femoral replacement has all but replaced cementing and cement technique is at risk for becoming a lost art. Published results of cemented femoral components with a well-designed femoral component and good surgical technique are excellent and equivalent to cementless technology. With an increasing focus on cost as part of value-based care, consideration for returning to cement for a select population is appropriate. Furthermore, there are patient populations that may benefit from a cemented femur with registries demonstrating superior short term outcomes. These include the elderly and patients with osteoporotic femurs. The goal of femoral cementing is to maximise the interdigitation of bone cement with metaphyseal trabecular bone and the irregular surface of the endosteum while at the same time minimizing the risk of embolization. The steps for femoral cementing include:cFemoral broaching – understand the relationship between the broach and stem as it relates to cement mantle thickness; Canal preparation; Gentle curetting to remove loose cancellous bone; Pressurised lavage to remove fat and marrow elements – this decreases the risk of embolization and enhances the strength of the bone-cement interface; Dry the canal – suction, adrenaline soaked sponge – this minimises bleeding and enhances the strength of the bone cement interface; Cement preparation – vacuum mix or centrifuge the bone cement – this minimise large voids that weaken the bone cement; Cement insertion – insert in a retrograde fashion and pressurise the cement – this optimises the cement column and the bone cement interface; Stem insertion – insert slowly with a system that centralises the stem – this prevents mantle defects that have been associated with stem loosening.
Bond Market Demand and Capital Structure Variation

This article investigates whether firms vary the debt side of their capital structure based on changes in investor demand for bonds. Examining asset flows into various asset classes over the last 30 years reveals that companies respond to recent increases in demand for bonds from investors by altering their capital structure toward greater use of debt. Firms are more likely to issue debt when demand for bonds rises, and their use of debt increases (decreases) in periods when demand for bonds is high (low) compared with periods when demand is not significantly changed. Firms use more (less) debt when spreads between corporate yields and Treasury rates are low (high), consistent with efforts by managers to adjust their debt issuances based on relative debt costs. These results hold after controlling for seasonality, firm effects, and macroeconomic conditions. These findings suggest that investor demand for debt needs to be taken into account when examining the capital structure puzzle.
Whole chromosome loss and associated breakage–fusion–bridge cycles transform mouse tetraploid cells

Abstract Whole chromosome gains or losses (aneuploidy) are a hallmark of ~70% of human tumors. Modeling the consequences of aneuploidy has relied on perturbing spindle assembly checkpoint (SAC) components, but interpretations of these experiments are clouded by the multiple functions of these proteins. Here, we used a Cre recombinase‐mediated chromosome loss strategy to individually delete mouse chromosomes 9, 10, 12, or 14 in tetraploid immortalized murine embryonic fibroblasts. This methodology also involves the generation of a dicentric chromosome intermediate, which subsequently undergoes a series of breakage–fusion–bridge (BFB) cycles. While the aneuploid cells generally display a growth disadvantage in vitro , they grow significantly better in low adherence sphere‐forming conditions and three of the four lines are transformed in vivo , forming large and invasive tumors in immunocompromised mice. The aneuploid cells display increased chromosomal instability and DNA damage, a mutator phenotype associated with tumorigenesis in vivo . Thus, these studies demonstrate a causative role for whole chromosome loss and the associated BFB‐mediated instability in tumorigenesis and may shed light on the early consequences of aneuploidy in mammalian cells.
A novel approach to retrieve arctic sea ice thickness for prediction and analysis

The overall reduction in sea ice thickness may have profound impact on the Earth's climate system, but currently predictive models do not have consistent sea ice thickness datasets available for improving their results through proper initialization and assimilation. We will present a novel approach to retrieve Arctic sea ice thickness from satellite observations. Our approach offers hemispheric scale sea ice thickness and volume at a temporal resolution shorter than a month (from days to weeks) by utilizing altimetry-derived thickness and passive microwave observations. Our method is validated against the airborne Operation IceBridge measuremnts. Moreover, as an application, we will show the gain obtained when assimilating our basin wide Arcitc sea ice thickness in the NASA Goddard Earth Observing System Model, version 5 (GEOS-5) ocean sea-ice data assimilation system.
Spectral Numerical Exterior Calculus Methods for Differential Equations on Radial Manifolds

We develop exterior calculus approaches for partial differential equations on radial manifolds. We introduce numerical methods that approximate with spectral accuracy the exterior derivative $$\mathbf {d}$$ , Hodge star $$\star $$ , and their compositions. To achieve discretizations with high precision and symmetry, we develop hyperinterpolation methods based on spherical harmonics and Lebedev quadrature. We perform convergence studies of our numerical exterior derivative operator $$\overline{\mathbf {d}}$$ and Hodge star operator $$\overline{\star }$$ showing each converge spectrally to $$\mathbf {d}$$ and $$\star $$ . We show how the numerical operators can be naturally composed to formulate general numerical approximations for solving differential equations on manifolds. We present results for the Laplace–Beltrami equations demonstrating our approach.
User Friendly Automatic Construction of Background Knowledge: Mode Construction from ER Diagrams

One of the key advantages of Inductive Logic Programming systems is the ability of the domain experts to provide background knowledge as modes that allow for efficient search through the space of hypotheses. However, there is an inherent assumption that this expert should also be an ILP expert to provide effective modes. We relax this assumption by designing a graphical user interface that allows the domain expert to interact with the system using Entity Relationship diagrams. These interactions are used to construct modes for the learning system. We evaluate our algorithm on a probabilistic logic learning system where we demonstrate that the user is able to construct effective background knowledge on par with the expert-encoded knowledge on five data sets.
Recurrently Mutated Genes Differ between Leptomeningeal and Solid Lung Cancer Brain Metastases.

When compared with solid brain metastases from NSCLC, leptomeningeal disease (LMD) has unique growth patterns and is rapidly fatal. Patients with LMD do not undergo surgical resection, limiting the tissue available for scientific research. In this study we performed whole exome sequencing on eight samples of LMD to identify somatic mutations and compared the results with those for 26 solid brain metastases. We found that taste 2 receptor member 31 gene (TAS2R31) and phosphodiesterase 4D interacting protein gene (PDE4DIP) were recurrently mutated among LMD samples, suggesting involvement in LMD progression. Together with a retrospective review of the charts of an additional 44 patients with NSCLC LMD, we discovered a surprisingly low number of KRAS mutations (n = 4 [7.7%]) but a high number of EGFR mutations (n = 33 [63.5%]). The median interval for development of LMD from NSCLC was shorter in patients with mutant EGFR (16.3 months) than in patients with wild-type EGFR (23.9 months) (p = 0.017). Targeted analysis of recurrent mutations thus presents a useful complement to the existing diagnostic tool kit, and correlations of EGFR in LMD and KRAS in solid metastases suggest that molecular distinctions or systemic treatment pressure underpin the differences in growth patterns within the brain.
A hybrid parallel Delaunay image-to-mesh conversion algorithm scalable on distributed-memory clusters

Abstract In this paper, we present a scalable three dimensional parallel Delaunay image-to-mesh conversion algorithm. A nested master–worker model is used to simultaneously explore process- and thread-level parallelization. The mesh generation includes two stages: coarse and fine meshing. First, a coarse mesh is constructed in parallel by the threads of the master process. Then the coarse mesh is partitioned. Finally, the fine mesh refinement procedure is executed until all the elements in the mesh satisfy the quality and fidelity criteria. The communication and computation are separated during the fine mesh refinement procedure. The master thread of each process that initializes the MPI environment is in charge of the inter-node MPI communication for data (submesh) movement while the worker threads of each process are responsible for the local mesh refinement within the node. We conducted a set of experiments to test the performance of the algorithm on distributed memory clusters and observed that the granularity of coarse level data decomposition, which affects the coarse level concurrency, has a significant influence on the performance of the algorithm. With the proper value of granularity, the algorithm is scalable to 45 distributed memory compute nodes (900 cores).
Incentives and the Supply of Effective Charter Schools

Charter school funding is typically set by formulas that provide the same amount for all students regardless of advantage or need. In this paper, I present evidence that this policy skews the distribution of students served by charters towards low-cost populations by influencing where charter schools decide to open and whether they survive. I develop and estimate an empirical model of charter school supply and competition to evaluate the effects of funding policies that aim to correct these incentives. To do this, I recover estimates of cost differentials across student populations by linking charter school effectiveness at raising student achievement with unique records of charter school expenditures gathered from Florida. I then leverage revealed preference with the exit and location choices of charter schools in an entry game to uncover how charter schools respond to competitive and financial incentives. The results indicate that a cost-adjusted funding formula would significantly increase the share of charter schools serving disadvantaged students with little reduction in the aggregate effectiveness of the sector.
Improving predictions of hydrological low-flow indices in ungaged basins using machine learning

Abstract We compare the ability of eight machine-learning models (elastic net, gradient boosting, kernel-k-nearest neighbors, two variants of support vector machines, M5-cubist, random forest, and a meta-learning ensemble M5-cubist model) and four baseline models (ordinary kriging, a unit area discharge model, and two variants of censored regression) to generate estimates of the annual minimum 7-day mean streamflow with an annual exceedance probability of 90% (7Q10) at 224 unregulated sites in South Carolina, Georgia, and Alabama, USA. The machine-learning models produced substantially lower cross validation errors compared to the baseline models. The meta-learning M5-cubist model had the lowest root-mean-squared-error of 26.72 cubic feet per second. Partial dependence plots show that 7Q10s are likely moderated by late summer and early fall precipitation and the infiltration capacity of basin soils.
Trade secrets and innovation: Evidence from the “inevitable disclosure” doctrine

Research Summary: Does heightened employer‐friendly trade secrecy protection help or hinder innovation? By examining U.S. state‐level legal adoption of a doctrine allowing employers to curtail inventor mobility if the employee would “inevitably disclose” trade secrets, we investigate the impact of a shifting trade secrecy regime on individual‐level patenting outcomes. Using a difference‐in‐differences design taking unaffected U.S. inventors as the comparison group, we find strengthening employer‐friendly trade secrecy adversely affects innovation. We then investigate why. We do not find empirical support for diminished idea recombination from suppressed inventor mobility as the operative mechanism. While shifting intellectual property protection away from patenting into trade secrecy has some explanatory power, our results are consistent with reduced individual‐level incentives to signaling quality to the external labor market. Managerial Summary: While managers often list trade secrecy protection as their most important appropriation mechanism form and basis of competitive advantage (even more often than formal intellectual property protection), researchers have a hard time studying the effect of such secrets. We use a changing trade secrecy legal environment in some U.S. states (the introduction of the inevitable disclosure doctrine [IDD]) to study its effect on inventor‐level innovation. We find that a strengthened employer‐friendly trade secrecy regime adversely affects inventor‐level innovation. While part of the effect is due to substituting trade secrecy protection for patents, we also find that inventors’ diminished external labor market prospects may dampen their innovation output. Consequently, while employers may wish for strengthened trade secrecy protections, the results may paradoxically be against their innovation interests.
Revenue Recognition at TSA, Inc.—A Roller Coaster Ride

ABSTRACT This case chronicles revenue recognition practices at TSA, Inc. from 1997 to 2002. As growth in TSA's revenue declined, the company's revenue recognition practices became more aggressive. ...
C. elegans Heterochromatin Factor SET-32 Plays an Essential Role in Transgenerational Establishment of Nuclear RNAi-Mediated Epigenetic Silencing

Summary The dynamic process by which nuclear RNAi engages a transcriptionally active target, before the repressive state is stably established, remains largely a mystery. Here, we found that the onset of exogenous dsRNA-induced nuclear RNAi in C. elegans is a transgenerational process, and it requires a putative histone methyltransferase (HMT), SET-32. By developing a CRISPR-based genetic approach, we found that silencing establishment at the endogenous targets of germline nuclear RNAi also requires SET-32. Although SET-32 and two H3K9 HMTs, MET-2 and SET-25, are dispensable for the maintenance of silencing, they do contribute to transcriptional repression in mutants that lack the germline nuclear Argonaute protein HRDE-1, suggesting a conditional role of heterochromatin in the maintenance phase. Our study indicates that (1) establishment and maintenance of siRNA-guided transcriptional repression are two distinct processes with different genetic requirements and (2) the rate-limiting step of the establishment phase is a transgenerational, chromatin-based process.
Quantification of Dynamic Model Validation Metrics Using Uncertainty Propagation from Requirements

The Space Launch System, NASA’s new large launch vehicle for long range space exploration, is presently in the final design and construction phases, with the first launch scheduled for 2019. A dynamic model of the system has been created and is critical for calculation of interface loads and natural frequencies and mode shapes for guidance, navigation, and control (GNC). Because of the program and schedule constraints, a single modal test of the SLS will be performed while bolted down to the Mobile Launch Pad just before the first launch. A Monte Carlo and optimization scheme will be performed to create thousands of possible models based on given dispersions in model properties and to determine which model best fits the natural frequencies and mode shapes from modal test. However, the question still remains as to whether this model is acceptable for the loads and GNC requirements. An uncertainty propagation and quantification (UP and UQ) technique to develop a quantitative set of validation metrics that is based on the flight requirements has therefore been developed and is discussed in this paper. There has been considerable research on UQ and UP and validation in the literature, but very little on propagating the uncertainties from requirements, so most validation metrics are “rules-of-thumb;” this research seeks to come up with more reason-based metrics. One of the main assumptions used to achieve this task is that the uncertainty in the modeling of the fixed boundary condition is accurate, so therefore that same uncertainty can be used in propagating the fixed-test configuration to the free-free actual configuration. The second main technique applied here is the usage of the limit-state formulation to quantify the final probabilistic parameters and to compare them with the requirements. These techniques are explored with a simple lumped spring-mass system and a simplified SLS model. When completed, it is anticipated that this requirements-based validation metric will provide a quantified confidence and probability of success for the final SLS dynamics model, which will be critical for a successful launch program, and can be applied in the many other industries where an accurate dynamic model is required.
Missing data and technical variability in single-cell RNA-sequencing experiments

Until recently, high-throughput gene expression technology, such as RNA-Sequencing (RNA-seq) required hundreds of thousands of cells to produce reliable measurements. Recent technical advances permit genome-wide gene expression measurement at the single-cell level. Single-cell RNA-Seq (scRNA-seq) is the most widely used and numerous publications are based on data produced with this technology. However, RNA-seq and scRNA-seq data are markedly different. In particular, unlike RNA-seq, the majority of reported expression levels in scRNA-seq are zeros, which could be either biologically-driven, genes not expressing RNA at the time of measurement, or technically-driven, genes expressing RNA, but not at a sufficient level to be detected by sequencing technology. Another difference is that the proportion of genes reporting the expression level to be zero varies substantially across single cells compared to RNA-seq samples. However, it remains unclear to what extent this cell-to-cell variation is being driven by technical rather than biological variation. Furthermore, while systematic errors, including batch effects, have been widely reported as a major challenge in high-throughput technologies, these issues have received minimal attention in published studies based on scRNA-seq technology. Here, we use an assessment experiment to examine data from published studies and demonstrate that systematic errors can explain a substantial percentage of observed cell-to-cell expression variability. Specifically, we present evidence that some of these reported zeros are driven by technical variation by demonstrating that scRNA-seq produces more zeros than expected and that this bias is greater for lower expressed genes. In addition, this missing data problem is exacerbated by the fact that this technical variation varies cell-to-cell. Then, we show how this technical cell-to-cell variability can be confused with novel biological results. Finally, we demonstrate and discuss how batch-effects and confounded experiments can intensify the problem.
General-relativistic neutron star evolutions with the discontinuous Galerkin method

Simulations of relativistic hydrodynamics often need both high accuracy and robust shock-handling properties. The discontinuous Galerkin method combines these features—a high order of convergence in regions where the solution is smooth and shock-capturing properties for regions where it is not—with geometric flexibility and is therefore well suited to solve the partial differential equations describing astrophysical scenarios. We present here evolutions of a general-relativistic neutron star with the discontinuous Galerkin method. In these simulations, we simultaneously evolve the spacetime geometry and the matter on the same computational grid, which we conform to the spherical geometry of the problem. To verify the correctness of our implementation, we perform standard convergence and shock tests. We then show results for evolving, in three dimensions, a Kerr black hole; a neutron star in the Cowling approximation (holding the spacetime metric fixed); and, finally, a neutron star where the spacetime and matter are both dynamical. The evolutions show long-term stability, good accuracy, and an improved rate of convergence versus a comparable-resolution finite-volume method.
Distributed power generation in national rural electrification plans: An international and comparative evaluation

Abstract As the cost of distributed power generation continues to decrease, technologies such as solar home systems and micro-grids become increasingly attractive in the quest for energy access. Here we show, however, that national rural electrification planning mostly continues to ignore distributed power generation. A detailed review of the national rural electrification plans of the twenty countries with the largest numbers of non-electrified households shows that distributed power generation is usually absent or at best a minor component of the strategy. Our original contribution is thus to show where and how national rural electrification planning lags behind technology and business models, with guidelines for future research on explaining these patterns.
An Auto-Calibrating Knee Flexion-Extension Axis Estimator Using Principal Component Analysis with Inertial Sensors.

Inertial measurement units (IMUs) have been demonstrated to reliably measure human joint angles—an essential quantity in the study of biomechanics. However, most previous literature proposed IMU-based joint angle measurement systems that required manual alignment or prescribed calibration motions. This paper presents a simple, physically-intuitive method for IMU-based measurement of the knee flexion/extension angle in gait without requiring alignment or discrete calibration, based on computationally-efficient and easy-to-implement Principle Component Analysis (PCA). The method is compared against an optical motion capture knee flexion/extension angle modeled through OpenSim. The method is evaluated using both measured and simulated IMU data in an observational study (n = 15) with an absolute root-mean-square-error (RMSE) of 9.24∘ and a zero-mean RMSE of 3.49∘. Variation in error across subjects was found, made emergent by the larger subject population than previous literature considers. Finally, the paper presents an explanatory model of RMSE on IMU mounting location. The observational data suggest that RMSE of the method is a function of thigh IMU perturbation and axis estimation quality. However, the effect size for these parameters is small in comparison to potential gains from improved IMU orientation estimations. Results also highlight the need to set relevant datums from which to interpret joint angles for both truth references and estimated data.
Large-scale Control of Kinetic Dissipation in the Solar Wind

In this Letter we study the connection between the large-scale dynamics of the turbulence cascade and particle heating on kinetic scales. We find that the inertial range turbulence amplitude ($\delta B_i$; measured in the range of 0.01-0.1 Hz) is a simple and effective proxy to identify the onset of significant ion heating and when it is combined with $\beta_{||p}$, it characterizes the energy partitioning between protons and electrons ($T_p/T_e$), proton temperature anisotropy ($T_{\perp}/T_{||}$) and scalar proton temperature ($T_p$) in a way that is consistent with previous predictions. For a fixed $\delta B_i$, the ratio of linear to nonlinear timescales is strongly correlated with the scalar proton temperature in agreement with Matthaeus et al., though for solar wind intervals with $\beta_{||p}>1$ some discrepancies are found. For a fixed $\beta_{||p}$, an increase of the turbulence amplitude leads to higher $T_p/T_e$ ratios, which is consistent with the models of Chandran et al. and Wu et al. We discuss the implications of these findings for our understanding of plasma turbulence.
Coevolution-based inference of amino acid interactions underlying protein function

Protein function arises from a poorly understood pattern of energetic interactions between amino acid residues. Sequence-based strategies for deducing this pattern have been proposed, but lack of benchmark data has limited experimental verification. Here, we extend deep-mutation technologies to enable measurement of many thousands of pairwise amino acid couplings in several homologs of a protein family - a deep coupling scan (DCS). The data show that cooperative interactions between residues are loaded in a sparse, evolutionarily conserved, spatially contiguous network of amino acids. The pattern of amino acid coupling is quantitatively captured in the coevolution of amino acid positions, especially as indicated by the statistical coupling analysis (SCA), providing experimental confirmation of the key tenets of this method. This work exposes the collective nature of physical constraints on protein function and clarifies its link with sequence analysis, enabling a general practical approach for understanding the structural basis for protein function.
Stochastic Flow Models with Delays and Applications to Multi-Intersection Traffic Light Control

Abstract We extend Stochastic Flow Models (SFMs), used for a large class of discrete event and hybrid systems, by including the delays which typically arise in flow movement. We apply this framework to the multi-intersection traffic light control problem by including transit delays for vehicles moving from one intersection to the next. Using Infinitesimal Perturbation Analysis (IPA) for this SFM with delays, we derive new on-line gradient estimates of several congestion cost metrics with respect to the controllable green and red cycle lengths. The IPA estimators are used to iteratively adjust light cycle lengths to improve performance and, in conjunction with a standard gradient-based algorithm, to obtain optimal values which adapt to changing traffic conditions. We introduce two new cost metrics to better capture congestion and show that the inclusion of delays in our analysis leads to improved performance relative to models that ignore delays.