cssi/SciSciGPT-SciSciNet huggingface dataset:
Potential of mean force for electrical conductivity of dense plasmas

Abstract The electrical conductivity in dense plasmas can be calculated with the relaxation-time approximation provided that the interaction potential between the scattering electron and the ion is known. To date there has been considerable uncertainty as to the best way to define this interaction potential so that it correctly includes the effects of ionic structure, screening by electrons and partial ionization. Current approximations lead to significantly different results with varying levels of agreement when compared to bench-mark calculations and experiments. We present a new way to define this potential, drawing on ideas from classical fluid theory to define a potential of mean force. This new potential results in significantly improved agreement with experiments and bench-mark calculations, and includes all the aforementioned physics self-consistently.
The effects of political competition on the generosity of public-sector pension plans

Abstract In politically competitive jurisdictions, there can be strong electoral incentives to increase the generosity of public pensions and simultaneously, to not fund them fully, in order to keep taxes low. I examine the relationship between political competition and generosity of public pensions using a panel dataset for 3000 local plans from Pennsylvania for the period 2003–2013. I find that as the level of political competition in a municipality increases, pension plans become more generous but this relationship holds true only for plans run by municipal governments. A one standard deviation increase in the level of political competition is associated with an increase in the generosity of municipal plans by about 3 percent ($340–504/ retiree/ year) with no effect on plans run by municipal authorities. The effects of political competition are driven by municipalities that have a higher proportion of uninformed voters and are absent for defined contribution plans.
Criticized, Fired, Sued, or Prosecuted: Hindsight and Public Health Accountability:

The charges filed by Michigan prosecutors against state public health officials related to the Legionnaires’ disease outbreak in Flint raise difficult questions about accountability and responsibility for public health officials. Judging by the facts as alleged in the criminal charges, the circumstances in the Michigan case appear to be extreme and not representative of the usual ways that public health officials make difficult decisions with the public’s interest at heart. Accountability is vital, but those concerned with good public health leadership must distinguish between reasonable decisions made in good faith that nevertheless turn out to be incorrect and unreasonable actions that harm public health and deserve accountability. Several viable options exist to achieve accountability when things go wrong and public health decision-making leads to harm.
Post-SOX downward auditor switches and their impacts on the nonprofit audit market

Abstract This study examines the extent of downward auditor switches from Big 4 audit firms by nonprofit organizations (NPOs) after enactment of the Sarbanes-Oxley Act (SOX). Although SOX provisions do not directly apply to nonprofit organizations, capacity constraints and client realignments due to SOX may have reduced the Big 4 presence in the nonprofit audit market. We find that downward switches from a Big 4 firm increased in the post-SOX period. Universities and colleges are more likely than other NPOs to have downward switches from a Big 4 audit firm in the post-SOX period compared to the pre-SOX period. These results suggest that SOX had differential impacts on NPOs depending on the nature of the organization. Risky NPOs, as indicated by the existence of internal control deficiencies, were more likely to have downward auditor switches. NPOs are more likely to choose a non-Big 4 specialist following a downward switch compared to other NPOs with non-Big 4 auditors, consistent with higher demand for audit quality by these organizations. We do not find significant evidence that downward switches for these organizations are associated with decreases in subsequent donations. However, we find that downward switchers are associated with increases in material weaknesses in internal control.
Can Merchant Demand Response Affect Investments in Merchant Energy Storage

Demand response (DR) and energy storage (ES) technologies are seen as almost perfect substitutes for providing spatiotemporal energy arbitrage in power systems with high penetrations of renewable generation. Using both technologies simultaneously is favorable from the system perspective, but may cause profit scarcity for merchant DR aggregators and ES investors. This paper presents an equilibrium problem with equilibrium constraints (EPEC) that models interactions between the merchant DR aggregator and the merchant ES investor in a competitive electricity market. The proposed EPEC is solved using the diagonalization method on an ISO New England testbed with a prospective renewable generation portfolio and different techno-economic parameters of prospective DR and ES technologies. The case study reveals that the optimal ES investments are sensitive to the availability of DR resources, as well as to the ES capital cost and cycling efficiency.
Countering Overseas Power in Global Value Chains: Information Asymmetries and Subcontracting in the Plastics Industry

Abstract Resource Dependency Theory (RDT) and Global Value Chain (GVC) analysis have been deployed in the strategic and international management literatures to address questions of power in dyadic relationships and global production networks, respectively. This paper integrates the two theoretical approaches in order to expand RDT, using insights from Hirschman's exit/voice model to show the options available to some firms but not others. Using the relationship between buyers and contract manufacturers from GVC analysis, we find a correlation between firm size and choice of strategic action in response to contract manufacturers' dependence on buyers. Large firms follow an acquiescence strategy while small manufacturers follow an avoidance strategy, able to use both exit and voice strategies. Enabled by scale or control over information, both of these approaches successfully reduce uncertainty and provide a source of sustained competitive advantage. Using a study of the production chain in consumer plastics manufacturing in China, we show how dependent firms respond to GVC induced pressure. We find that based on the size of the contract manufacturer, the range of strategic responses to power is constrained by the nature of the dependency in global value chains. This opens important insights into the role that structural characteristics of organizations (like size) play in determining strategic freedom.
Using VRML to Communicate Device Gamuts

ABSTRACT VRML or the Virtual Reality Markup Language offers a powerful tool for rendering and distributing device gamuts in athree-dimensional format. This format is an open standard and is supported by multiple plug-ms for web browsers.' TheVRML format also allows interactive exploration of the gamuts, including unusual views such as the interior of the gamut. Inaddition, standard camera viewpoints can be used to view the gamut at a subset of useful fixed vantage points. This papercovers basic gamut rendering using VRML, including using a sufficient surface sampling rate. Some options to enhance thegamut rendering are also discussed and an example comparing three device gamuts is presented.Keywords: gamut rendering, gamut processing, data visualization, gamut surface sampling rate, VRML encoding 1. INTRODUCTION The gamut ofa device is the range ofpossible colors that can be reproduced by that device. A device gamut can be visualizedas a three dimensional object where the surface of the gamut defmes the limit of colors that can be reproduced.2 The size andshape of the gamut are a fundamental imaging characteristic of that device.3 Gamut considerations influence designdecisions, such as gray component replacement,4 and are also critical as input parameters for gamut mapping algorithms.5'6Gamut visualization is an essential component in designing, implementing and testing these and related algorithms.7Previous tools have been developed specifically for gamut rendering and visualization, but have been either dedicatedapplications8 or taken advantage of the three-dimensional graphics capabilities of various scientific applications, such asMathematica, Matlab or AVS. However, distributing, maintaining and upgrading a dedicated gamut visualization applicationis a time consuming and expensive undertaking. Likewise, it is often difficult to standardize on one scientific applicationacross multiple platforms just to improve communication of device gamuts. In addition the user interfaces for navigatingthree-dimensional graphics in many scientific applications can involve a steep learning curve.In comparison, VRML is a standard language for creating and distributing three dimensional data or worlds. It offers similar
Communication Steps for Parallel Query Processing

We study the problem of computing conjunctive queries over large databases on parallel architectures without shared storage. Using the structure of such a query q and the skew in the data, we study tradeoffs between the number of processors, the number of rounds of communication, and the per-processor load—the number of bits each processor can send or can receive in a single round—that are required to compute q. Since each processor must store its received bits, the load is at most the number of bits of storage per processor.When the data are free of skew, we obtain essentially tight upper and lower bounds for one round algorithms, and we show how the bounds degrade when there is skew in the data. In the case of skewed data, we show how to improve the algorithms when approximate degrees of the (necessarily small number of) heavy-hitter elements are available, obtaining essentially optimal algorithms for queries such as skewed simple joins and skewed triangle join queries.For queries that we identify as treelike, we also prove nearly matching upper and lower bounds for multi-round algorithms for a natural class of skew-free databases. One consequence of these latter lower bounds is that for any v > 0, using p processors to compute the connected components of a graph, or to output the path, if any, between a specified pair of vertices of a graph with m edges and per-processor load that is O(m/p1−v) requires Ω(logp) rounds of communication.Our upper bounds are given by simple structured algorithms using MapReduce. Our one-round lower bounds are proved in a very general model, which we call the Massively Parallel Communication (MPC) model, that allows processors to communicate arbitrary bits. Our multi-round lower bounds apply in a restricted version of the MPC model in which processors in subsequent rounds after the first communication round are only allowed to send tuples.
Peer communication improves environmental employee engagement programs: Evidence from a quasi-experimental field study

Abstract Environmental employee engagement programs promise to raise employee morale, improve social and environmental conditions and strengthen companies' financial performance. Such programs, however, sometimes fail to improve employee engagement, often because employees do not believe in the program's authenticity. This study evaluates peer communication as a mechanism for improving the credibility of employee engagement programs. We use a quasi-experimental research design in which employees from different regional offices of a single company were placed in either a treatment group that experienced a peer communication program or a control group that did not. Pre- and post-test surveys measured employees' affective, cognitive and behavioral engagement with their work. Treatment group employees showed increases in pride in the company's environmental initiatives and accomplishments, confidence in discussing its environmental record with external stakeholders, and awareness of and participation in its employee environmental programs. These changes were significantly greater than what occurred in the control groups, suggesting that the peer communication program was generally effective at improving employee engagement. These results demonstrate new modes of internal communication that can strengthen companies' environmental performance and improve employee-related outcomes.
Manu Militari: The Institutional Contingencies of Stakeholder Relationships on Entrepreneurial Performance

This study examines how ventures can leverage relationships with heterogeneous government stakeholders to enhance survival in different institutional environments. We consider how the distinct resources provided from venture ties to military and political actors represent complementary strategic assets that differentially influence performance in varying political and economic environments as well as under conditions of violence and political conflict. Empirically, we examine the effect of these respective stakeholder relationships on new venture survival across 10 countries over a 65-year period. By distinguishing between the resources obtained through relationships with different types of government stakeholders and showing how the value of these resources varies in different contexts, this study contributes to nonmarket strategy and stakeholder management research and highlights the need for studies to take a pluralistic view of government stakeholders. This paper also presents managerial insights to f...
Inference about the slope in linear regression: an empirical likelihood approach

We present a new, efficient maximum empirical likelihood estimator for the slope in linear regression with independent errors and covariates. The estimator does not require estimation of the influence function, in contrast to other approaches, and is easy to obtain numerically. Our approach can also be used in the model with responses missing at random, for which we recommend a complete case analysis. This suffices thanks to results by Muller and Schick (Bernoulli 23:2693–2719, 2017), which demonstrate that efficiency is preserved. We provide confidence intervals and tests for the slope, based on the limiting Chi-square distribution of the empirical likelihood, and a uniform expansion for the empirical likelihood ratio. The article concludes with a small simulation study.
Annular Air Leaks in a liquid hydrogen storage tank

Large liquid hydrogen (LH2) storage tanks are vital infrastructure for NASA, the DOD, and industrial users. Over time, air may leak into the evacuated, perlite filled annular region of these tanks. Once inside, the extremely low temperatures will cause most of the air to freeze. If a significant mass of air is allowed to accumulate, severe damage can result from nominal draining operations. Collection of liquid air on the outer shell may chill it below its ductility range, resulting in fracture. Testing and analysis to quantify the thermal conductivity of perlite that has nitrogen frozen into its interstitial spaces and to determine the void fraction of frozen nitrogen within a perlite/frozen nitrogen mixture is presented. General equations to evaluate methods for removing frozen air, while avoiding fracture, are developed. A hypothetical leak is imposed on an existing tank geometry and a full analysis of that leak is detailed. This analysis includes a thermal model of the tank and a time-to-failure calculation. Approaches to safely remove the frozen air are analyzed, leading to the conclusion that the most feasible approach is to allow the frozen air to melt and to use a water stream to prevent the outer shell from chilling.
Developing nanoscale materials using biomimetic assembly processes

The formation and nature of living materials are fundamentally different from those of synthetic materials. Synthetic materials generally have static structures, and are not capable of adapting to changing environmental conditions or stimuli. In contrast, living systems utilize energy to assemble, reconfigure, and dismantle materials in a dynamic, highly non-equilibrium fashion. The overall goal of this work is to identify and explore key strategies used by living systems to develop new types of materials in which the assembly, configuration, and disassembly can be programmed or “self-regulated” in microfluidic environments. As a model system, kinesin motor proteins and microtubule fibers have been selected as a means of directing the transport of molecular cargo, and assembly of nanostructures at synthetic interfaces. Initial work has focused on characterizing and engineering the properties of these active biomolecules for robust performance in microfluidic systems. We also have developed several strategies for functionalizing microtubule fibers with metal and semiconductor nanoparticles, and demonstrated the assembly of composite nanoscale materials. Moreover, transport of these composite assemblies has been demonstrated using energy-driven actuation by kinesin motor proteins. Current work is focused on developing mechanisms for directing the linear transport of microtubule fibers, and controlling the loading/unloading of nanoparticle cargo in microfluidic systems.
Role of MicroRNAs in Renal Parenchymal Diseases—A New Dimension

Since their discovery in 1993, numerous microRNAs (miRNAs) have been identified in humans and other eukaryotic organisms, and their role as key regulators of gene expression is still being elucidated. It is now known that miRNAs not only play a central role in the processes that ensure normal development and physiology, but they are often dysregulated in various diseases. In this review, we present an overview of the role of miRNAs in normal renal development and physiology, in maladaptive renal repair after injury, and in the pathogenesis of renal parenchymal diseases. In addition, we describe methods used for their detection and their potential as therapeutic targets. Continued research on renal miRNAs will undoubtedly improve our understanding of diseases affecting the kidneys and may also lead to new therapeutic agents.
Elevated and Correlated Expressions of miR-24, miR-30d, miR-146a, and SFRP-4 in Human Abdominal Adipose Tissue Play a Role in Adiposity and Insulin Resistance.

Objective We explored the relationships among microRNAs (miRNAs) and SFRP4, as they relate to adipose tissue functions including lipolysis, glucose and glycerol turnover, and insulin sensitivity. Methods Abdominal adipose tissue (AbdAT) levels of thirteen microRNAs (miRNAs), SFRP4, and VEGF in lean nondiabetic subjects (n = 7), subjects with obesity (n = 5), and subjects with obesity and type 2 diabetes (T2DM) (n = 5) were measured by qPCR. Insulin sensitivity was measured by the euglycemic-hyperinsulinemic clamp. Osmium fixation and Coulter counting were used for adipocyte sizing. Data were analyzed using generalized linear models that adjusted for age, gender, and ethnicity. Results AbdAT miR-24, miR-30d, and miR-146a were elevated in subjects with obesity (P < 0.05) and T2DM (P < 0.1) and positively correlated with measures of percent body fat by DXA (rmiR.24 = 0.894, rmiR.146a = 0.883, P < 0.05), and AbdAT SFRP4 (rmiR.30 = 0.93, rmiR.146a = 0.88, P < 0.05). These three miRNAs additionally correlated among themselves (rmiR.24~miR.146a = 0.90, rmiR.30~miR.146a = 0.85, P < 0.01). Conclusions This study suggests a novel association between the elevated levels of miRNAs miR-24, miR-30d, and miR-146a (apparently coregulated) and the level of SFRP4 transcript in AbdAT of subjects with obesity and T2DM. These molecules might be part of a regulatory loop involved in AbdAT remodeling/adiposity and systemic insulin resistance. This trial is registered with NCT00704197.
Development of a New Monochrome Multiplex qPCR Method for Relative Telomere Length Measurement in Cancer

Excess telomere shortening has been observed in most cancer cells. The telomere quantitative polymerase chain reaction (qPCR) assay has become an important tool for epidemiological studies examining the effects of aging, stress, and other factors on the length of telomeres. Current telomere qPCR methods analyze the relative length of telomeres by amplifying telomere sequence products and normalizing with single-copy gene products. However, the current telomere qPCR does not always reflect absolute telomere length in cancer DNA. Because of genomic instability in cancer cells, we hypothesized that the use of single-copy genes (scg) is less accurate for normalizing data in cancer DNA and that new primer sets are required to better represent relative telomere length in cancer DNA. We first confirmed that cancer cells had a different copy ratio among different scg, implying that DNA is aneuploid. By using the new primer sets that amplify multiple-copy sequences (mcs) throughout the genome, the telomere qPCR results showed that the mcs primers were interchangeable with the scg primers as reference primers in normal DNA. By comparing results from the traditional southern blotting method (as kilobases) and results from monochrome multiplex qPCR using the mcs primers (as T/M ratios), we verified that the T/M ratio is highly correlated with absolute telomere length from the southern blot analysis. Together, the mcs primers were able to represent the telomere lengths accurately in cancer DNA samples. These results would allow for analyses of telomeres within cancerous DNA and the development of new, less invasive diagnostic tools for cancer.
Orlistat Therapy for Children With Type 1 Hyperlipoproteinemia: A Randomized Clinical Trial.

Context Patients with type 1 hyperlipoproteinemia (T1HLP), a rare genetic disorder, have extreme chylomicronemia and recurrent episodes of acute pancreatitis. Currently, the only therapeutic option is to consume an extremely low-fat diet because the triglyceride-lowering medications are not efficacious. Objective To determine the efficacy of orlistat, a gastric and pancreatic lipase inhibitor, in reducing serum triglyceride levels in patients with T1HLP. Design and setting We conducted a randomized, open-label, clinical trial with a four-period, two-sequence ("orlistat" and "off orlistat" for 3 months), crossover study design. Patients Two unrelated young Asian Indian males (11 and 9 years old) with T1HLP due to homozygous large GPIHBP1 deletions were enrolled at the UT Southwestern Medical Center. The patients were randomized to receive 3 months of orlistat or no therapy (off), then crossed over to the other arm, and this sequence was then repeated. Fasting serum triglyceride levels, fat-soluble vitamins, and gastrointestinal side effects were assessed. Results Compared with the two off periods, orlistat therapy reduced serum triglycerides by 53.3% and 53.0% in patient 1 and 45.8% and 62.2% in patient 2. There was no deficiency of fat-soluble vitamin levels, and their growth continued. There were no serious adverse effects of orlistat; patient 1 had a mild increase in passage of gas and bloating, and patient 2 had constipation with mild stool leakage. Conclusion Orlistat is safe and highly efficacious in lowering serum triglycerides in children with T1HLP and should be the first-line therapy in conjunction with an extremely low-fat diet.
Repair of Thoracic and Thoracoabdominal Mycotic Aneurysms and Infected Aortic Grafts Using Allograft.

Background Mycotic aneurysm of the thoracic or thoracoabdominal aorta and infection of thoracic or thoracoabdominal aortic grafts are challenging problems with high mortality. In situ reconstruction with cryopreserved allograft (CPA) avoids placement of prosthetic material in an infected field and avoids suppressive antibiotics or autologous tissue coverage. Methods Fifty consecutive patients with infection of a thoracic or thoracoabdominal aortic graft or mycotic aneurysm underwent resection and replacement with CPA from 2006 to 2016. Intravenous antibiotics were continued postoperatively for 6 weeks. Long-term suppressive antibiotics were uncommonly used (8 patients). Follow-up imaging occurred at 6, 18, and 42 months postoperatively. Initial follow-up was 93% complete. Results Men comprised 64% of the cohort. The mean age was 63 ± 14 years. The procedures performed included reoperations in 37 patients; replacement of the aortic root, ascending aorta, or transverse arch in 19; replacement of the descending or thoracoabdominal aorta in 27; and extensive replacement of the ascending, arch, and descending or thoracoabdominal aorta in 4. Intraoperative cultures revealed most commonly Staphylococcus (24%), Enterococcus (12%), Candida (6%), and gram-negative rods (14%). Operative mortality was 8%, stroke was 4%, paralysis was 2%, hemodialysis was 6%, and respiratory failure requiring tracheostomy was 6%. Early reoperation for pseudoaneurysm of the CPA was necessary in 4 patients. One-, 2-, and 5-year survival was 84%, 76%, and 64%, respectively. Conclusions Radical resection and in situ reconstruction with CPA avoids placing prosthetic material in an infected field and provides good early and midterm outcomes. However, early postoperative imaging is necessary given the risk of pseudoaneurysm formation.
Cultural Identity and Materiality at French Fort St. Joseph (20BE23), Niles, Michigan

Fort St. Joseph was one of many French colonial outposts established throughout the St. Lawrence River valley and the western Great Lakes region in the late 17th to 18th centuries to cultivate alliances with native peoples. The result was an exchange, amalgamation, and reinterpretation of material goods that testify to the close relationships the French maintained with various Native American groups. Yet, closer examination suggests that both the French and natives employed material goods in distinctive ways to ensure survival and promote their interests in the colonial encounter; borrowing was merely an expedient strategy. This interpretation shifts attention away from the amicable relations, altruistic behaviors, and hybridization that researchers previously posited toward an understanding grounded in more pragmatic forms of materiality that agents practice to ensure the persistence of cultural identities under colonialism.
A Theory of Equality Before the Law

We propose a simple model of the emergence of equality before the law. A society can support effort (‘cooperation’, ‘prosocial behaviour’) using the carrot of future cooperation or the stick of coercive punishment. Community enforcement relies only on the carrot and involves low coercion, low inequality and low effort. A society in which elites control the means of violence supplements the carrot with the stick, and involves high coercion, high inequality and high effort. In this regime, elites are privileged by both laws and norms: because they are not subject to the same punishments as non-elites, norms are also more favourable for them. Nevertheless, it may be optimal—even from the elites’ perspective—to establish equality before the law, where all agents are subject to the same coercive punishments and norms are more equal. The key mechanism is that equality before the law increases elites’ effort, which improves the carrot of future cooperation and thus encourages even higher effort from non-elites. Equality before the law combines high coercion and low inequality. Factors that make equality before the law more likely to emerge include limits on the extent of coercion, greater marginal returns to effort, increases in the size of the elite group, greater political power for non-elites and, under some additional conditions, lower economic inequality.
Research productivity of faculty at 30 leading marketing departments

This manuscript documents the research productivity over a 10-year period (2007–2016) of marketing faculty at 30 leading marketing departments. We find that median productivity in the top four marketing journals was 0.40 publications per year. We find no meaningful difference in productivity between “quant” and “behavioral” faculty. Furthermore, we find a slow decrease in productivity as faculty’s “academic age” increases, but we also find that the most productive members of our community are among the colleagues who received their PhDs 20 to 30 years ago and that academic age is not a good predictor when recent productivity is taken into account. In addition, we find that the departments differ strongly in terms of the concentration of publications among faculty, as measured by the Gini coefficient. Finally, and to our surprise, we find that the number of publications in top journals by the faculty at these 30 schools dropped quite precipitously from the 2007–2011 to the 2012–2016 period.
Regulatory cooperation and foreign portfolio investment

Abstract We investigate the effect of cross-border regulatory cooperation in the enforcement of securities laws on global-mutual-fund portfolio allocations. Our research design exploits a shock to the Securities and Exchange Commission’s oversight of foreign firms cross-listed on a US stock exchange around the signing of the Multilateral Memorandum of Understanding (MMoU), a non-binding, information-sharing arrangement between global securities regulators. In signatory countries, foreign investment in US-cross-listed firms increases by $110 billion relative to non-cross-listed firms. The strongest effects are for investors facing greater information asymmetries, those from countries closely linked to the US, and non-US foreign investors, suggesting significant spillover effects from international regulatory cooperation.
Interplanetary dust delivery of water to the atmospheres of Pluto and Triton

Context . Both Pluto and Triton possess thin, N2 -dominated atmospheres controlled by sublimation of surface ices.Aims . We aim to constrain the influx and ablation of interplanetary dust grains into the atmospheres of both Pluto and Triton in order to estimate the rate at which oxygen-bearing species are introduced into both atmospheres.Methods . We use (i) an interplanetary dust dynamics model to calculate the flux and velocity distributions of interplanetary dust grains relevant for both Pluto and Triton and (ii) a model for the ablation of interplanetary dust grains in the atmospheres of both Pluto and Triton. We sum the individual ablation profiles over the incoming mass and velocity distributions of interplanetary dust grains in order to determine the vertical structure and net deposition of water to both atmospheres.Results . Our results show that 99% of water ice grains ablate at Pluto and Triton, respectively. From ice grains, we calculate net water influxes to Pluto and Triton of ~3.8 kg day−1 (8.5 × 103 H2 O cm−2 s−1 ) and ~370 kg day−1 (6.2 × 105 H2 O cm−2 s−1 ), respectively. The significant difference in total water deposition between Pluto and Triton is due to the presence of Triton within Neptune’s gravity well, which both enhances interplanetary dust particle (IDP) fluxes due to gravitational focusing and accelerates grains before entry into Triton’s atmosphere, thereby causing more efficient ablation.Conclusions . We conclude that water deposition from dust ablation plays only a minor role at Pluto due to its relatively low flux. At Triton, water deposition from IDPs is more significant and may play a role in the alteration of atmospheric and ionospheric chemistry. We also suggest that meteoric smoke and smaller, unablated grains may serve as condensation nuclei for the formation of hazes at both worlds.
Fine-pointing performance and corresponding photometric precision of the Transiting Exoplanet Survey Satellite

The Transiting Exoplanet Survey Satellite (TESS) is an MIT-led, NASA-funded Explorer-class planet finder launched in April 2018. TESS will carry out a 2-year all-sky survey with the primary goal of detecting small transiting exoplanets around bright and nearby stars. The TESS instrument consists of four wide-field cameras in a stacked configuration, providing a combined field of view of 24 deg × 96 deg that spans approximately from the ecliptic plane to the ecliptic pole. In order to achieve the desired photometric precision necessary for the mission, TESS uses the instrument cameras as star trackers during fine-pointing mode to enhance attitude accuracy and stabilization for science operations. We present our approach in quantifying the expected performance of the fine-pointing system and assessing the impact of pointing performance on the overall photometric precision of the mission. First, we describe the operational details of the fine-pointing system with the science instrument being used for star-tracking. Next, we present the testing framework used to quantify the attitude determination performance of the system and the expected attitude knowledge accuracy results, both in coarse-fine pointing hand-off and in nominal fine-pointing conditions. By combining simulations of the instrument and the spacecraft bus, we quantify the closed-loop fine-pointing stability performance of the system in nominal science operations as well as in the case of camera unavailability due to Earth/Moon interference. Finally, we assess the impact of platform pointing stability on the photometric precision of the system using detailed system modeling and discuss the applicability of mitigation techniques to reduce the effect of jitter on TESS science data.
Effects of transcranial focused ultrasound on human primary motor cortex using 7T fMRI: a pilot study.

Transcranial focused ultrasound (tFUS) is a new non-invasive neuromodulation technique that uses mechanical energy to modulate neuronal excitability with high spatial precision. tFUS has been shown to be capable of modulating EEG brain activity in humans that is spatially restricted, and here, we use 7T MRI to extend these findings. We test the effect of tFUS on 7T BOLD fMRI signals from individual finger representations in the human primary motor cortex (M1) and connected cortical motor regions. Participants (N = 5) performed a cued finger tapping task in a 7T MRI scanner with their thumb, index, and middle fingers to produce a BOLD signal for individual M1 finger representations during either tFUS or sham neuromodulation to the thumb representation. Results demonstrated a statistically significant increase in activation volume of the M1 thumb representation for the tFUS condition as compared to sham. No differences in percent BOLD changes were found. This effect was spatially confined as the index and middle finger M1 finger representations did not show similar significant changes in either percent change or activation volume. No effects were seen during tFUS to M1 in the supplementary motor area or the dorsal premotor cortex. Single element tFUS can be paired with high field MRI that does not induce significant artifact. tFUS increases activation volumes of the targeted finger representation that is spatially restricted within M1 but does not extend to functionally connected motor regions. Trial registration ClinicalTrials.gov NCT03634631 08/14/18
Two Faces of Corporate Lobbying: Evidence from the Pharmaceutical Industry

Abstract In this study, we examine how political connections increase firms’ innovation performance. By examining firm-level lobbying activities, we find that political connections lead to a greater number of medical breakthroughs among pharmaceutical firms in our sample. We then examine the underlying ways that political connections enhance innovation among medical firms. Using hand-collected data on government subsidies, we find that politically connected firms have a higher chance of receiving subsidies from federal, state, or local government agencies. These government subsidies enhance medical innovation by insulating managers from short-term threats and mitigate their career concerns by creating a “failure tolerant” environment. Overall, we show that connections between firms and politicians come with increased innovation outcomes.
Optimal Rotational Load Shedding Via Bilinear Integer Programming

This paper addresses the problem of managing rotational load shedding schedules for a power distribution network with multiple load zones. An integer optimization problem is formulated to find the optimal number and duration of planned power outages. Various types of damage costs are proposed to capture the heterogeneous load shedding preferences of different zones. The McCormick relaxation along with an effective procedure feasibility recovery is developed to solve the resulting bilinear integer program, which yields a high-quality suboptimal solution. Extensive simulation results corroborate the merit of the proposed approach, which has a substantial edge over existing load shedding schemes.
Do explanations make VQA models more predictable to a human

A rich line of research attempts to make deep neural networks more transparent by generating human-interpretable ‘explanations’ of their decision process, especially for interactive tasks like Visual Question Answering (VQA). In this work, we analyze if existing explanations indeed make a VQA model — its responses as well as failures — more predictable to a human. Surprisingly, we find that they do not. On the other hand, we find that human-in-the-loop approaches that treat the model as a black-box do.
Optimized libraries for CRISPR-Cas9 genetic screens with multiple modalities

The creation of genome-wide libraries for CRISPR knockout (CRISPRko), interference (CRISPRi), and activation (CRISPRa) has enabled the systematic interrogation of gene function. Here, we show that our recently-described CRISPRko library (Brunello) is more effective than previously published libraries at distinguishing essential and non-essential genes, providing approximately the same perturbation-level performance improvement over GeCKO libraries as GeCKO provided over RNAi. Additionally, we present genome-wide libraries for CRISPRi (Dolcetto) and CRISPRa (Calabrese), and show in negative selection screens that Dolcetto, with fewer sgRNAs per gene, outperforms existing CRISPRi libraries and achieves comparable performance to CRISPRko in detecting essential genes. We also perform positive selection CRISPRa screens and demonstrate that Calabrese outperforms the SAM approach at identifying vemurafenib resistance genes. We further compare CRISPRa to genome-scale libraries of open reading frames (ORFs). Together, these libraries represent a suite of genome-wide tools to efficiently interrogate gene function with multiple modalities.
Giant number fluctuations in dry active polar fluids: A shocking analogy with lightning rods.

It has been shown [H. Chate et al., Phys. Rev. E 77, 046113 (2008) and F. Ginelli, Eur. Phys. J.: Spec. Top. 225, 2099 (2016)] that the hydrodynamic equations of dry active polar fluids (i.e., moving flocks without momentum conservation) imply giant number fluctuations. Specifically, the rms fluctuations ⟨(δN)2⟩ of the number N of active particles in a region containing a mean number of active particles ⟨N⟩ scale according to the law ⟨(δN)2⟩=K′⟨N⟩ϕ(d) with ϕ(d)=710+15d in d ≤ 4 spatial dimensions. This is much larger than the “law of large numbers” scaling ⟨(δN)2⟩=K⟨N⟩ found in most equilibrium and nonequilibrium systems. In this paper, it is demonstrated that giant number fluctuations also depend singularly on the shape of the box in which one counts the particles, vanishing in the limit of very thin and very fat boxes. These fluctuations arise not from large density fluctuations—indeed, the density fluctuations in polar ordered dry active fluids are not in general particularly large—but from long ranged spatial correlations between those fluctuations. These are shown to be closely related in two spatial dimensions to the electrostatic potential near a sharp upward pointing conducting wedge of opening angle 3π4=135° and in three dimensions to the electrostatic potential near a sharp upward pointing charged cone of opening angle 37.16°. This very precise prediction can be stringently tested by alternative box counting experiments that directly measure the direction dependence, as well as the scaling with distance, of the density-density correlation function.
Topological Characteristics of Random Multihop Wireless Networks

Multihop wireless networks are treated as random symmetric planar point graphs, where all the nodes have the same transmission power and radius, and vertices of a graph are drawn randomly over certain geographical region. Several basic and important topological properties of random multihop wireless networks are studied, including node degree, connectivity, diameter, bisection width, and biconnectivity. It is believed that such study has very useful implication in real applications.
Laminar matroids

A laminar family is a collection A of subsets of a set E such that, for any two intersecting sets, one is contained in the other. For a capacity function c on A, let I be {I:|IA|c(A) forall AA}. Then I is the collection of independent sets of a (laminar) matroid on E. We present a method of compacting laminar presentations, characterize the class of laminar matroids by their excluded minors, present a way to construct all laminar matroids using basic operations, and compare the class of laminar matroids to other well-known classes of matroids.
Evaluation of segmentation algorithms for optical coherence tomography images of ovarian tissue

Ovarian cancer has the lowest survival rate among all gynecologic cancers predominantly due to late diagnosis. Early detection of ovarian cancer can increase 5-year survival rates from 40% up to 92%, yet no reliable early detection techniques exist. Optical coherence tomography (OCT) is an emerging technique that provides depth-resolved, high-resolution images of biological tissue in real-time and demonstrates great potential for imaging of ovarian tissue. Mouse models are crucial to quantitatively assess the diagnostic potential of OCT for ovarian cancer imaging; however, due to small organ size, the ovaries must first be separated from the image background using the process of segmentation. Manual segmentation is time-intensive, as OCT yields three-dimensional data. Furthermore, speckle noise complicates OCT images, frustrating many processing techniques. While much work has investigated noise-reduction and automated segmentation for retinal OCT imaging, little has considered the application to the ovaries, which exhibit higher variance and inhomogeneity than the retina. To address these challenges, we evaluate a set of algorithms to segment OCT images of mouse ovaries. We examine five preprocessing techniques and seven segmentation algorithms. While all preprocessing methods improve segmentation, Gaussian filtering is most effective, showing an improvement of 32 % ± 1.2 % . Of the segmentation algorithms, active contours performs best, segmenting with an accuracy of 94.8 % ± 1.2 % compared with manual segmentation. Even so, further optimization could lead to maximizing the performance for segmenting OCT images of the ovaries.
Work of the Past, Work of the Future

US cities today are vastly more educated and skill-intensive than they were five decades ago. Yet, urban non-college workers perform substantially less skilled jobs than decades earlier. This deskilling reflects the joint effects of automation and, secondarily, rising international trade, which have eliminated the bulk of non-college production, administrative support, and clerical jobs, yielding a disproportionate polarization of urban labor markets. The unwinding of the urban non-college occupational skill gradient has, I argue, abetted a secular fall in real non-college wages by: (1) shunting non-college workers out of specialized middle-skill occupations into low-wage occupations that require only generic skills; (2) diminishing the set of non-college workers that hold middle-skill jobs in high-wage cities; and (3) attenuating, to a startling degree, the steep urban wage premium for non-college workers that prevailed in earlier decades. Changes in the nature of work—many of which are technological in origin—have been more disruptive and less beneficial for non-college than college workers.
Financial reforms and corruption: Evidence using GMM estimation

Abstract This paper assesses the impact of financial reforms on corruption using a panel of 87 countries for 1984–2005. To account for the dynamic nature and high persistence of corruption, the paper employs the difference and system generalized method of moments (GMM) estimators. It finds that policy reforms targeted towards financial liberalization reduce corruption. This result is robust to the inclusion of a number of control variables and the choice of the GMM estimator. Interestingly, the financial liberalization index is found to be positively correlated with corruption though this relationship is not robust. The findings also indicate that legal origins do not impose a binding constraint on the effectiveness of financial reforms in reducing corruption.
A Comparative Analysis of Android Malware.

In this paper, we present a comparative analysis of benign and malicious Android applications, based on static features. In particular, we focus our attention on the permissions requested by an application. We consider both binary classification of malware versus benign, as well as the multiclass problem, where we classify malware samples into their respective families. Our experiments are based on substantial malware datasets and we employ a wide variety of machine learning techniques, including decision trees and random forests, support vector machines, logistic model trees, AdaBoost, and artificial neural networks. We find that permissions are a strong feature and that by careful feature engineering, we can significantly reduce the number of features needed for highly accurate detection and classification.
Utilizing a PTPN22 gene signature to predict response to targeted therapies in rheumatoid arthritis.

Abstract Despite the development of several targeted therapies for rheumatoid arthritis (RA), there is still no reliable drug-specific predictor to assist rheumatologists in selecting the most effective targeted therapy for each patient. Recently, a gene signature caused by impaired induction of PTPN22 in anti-CD3 stimulated peripheral blood mononuclear cells (PBMC) was observed in healthy at-risk individuals. However, the downstream target genes of PTPN22 and the molecular mechanisms regulating its expression are still poorly understood. Here we report that the PTPN22 gene signature is also present in PBMC from patients with active RA and can be reversed after effective treatment. The expression of PTPN22 correlates with that of more than 1000 genes in Th cells of anti-CD3 stimulated PBMC of healthy donors and is inhibited by TNFα or CD28 signals, but not IL-6, through distinct mechanisms. In addition, the impaired induction of PTPN22 in PBMC of patients with active RA can be normalized in vitro by several targeted therapies. More importantly, the in vitro normalization of PTPN22 expression correlates with clinical response to the targeted therapies in a longitudinal RA cohort. Thus, in vitro normalization of PTPN22 expression by targeted therapies can potentially be used to predict clinical response.