cssi/SciSciGPT-SciSciNet huggingface dataset:
Orbscan pachymetry: Implications of a repeated measures and diurnal variation analysis ∗

Abstract Introduction Corneal thickness changes reflect alterations in hydration and metabolism. Ultrasound pachymetry determinations may be adversely influenced by fluctuations in tissue hydration, whereas optical systems are apparently unaffected by these fluxes. A recently marketed, optical-based, topographic mapping system (Orbscan; Orbtek, Inc.) uses anterior and posterior corneal surface data to calculate corneal thickness. Objective This new instrumentation presents as a potentially useful pachymetry tool for evaluation of corneas under hydration flux or challenge (e.g., postphotorefractive keratectomy [PRK] healing studies) and was therefore evaluated for accuracy and variability. Measurements Three calibrated standards were measured in repeated fashion. Additionally, 1 test subject was measured 30 times in 1 day (5 measurements each at 8:00, 9:30, and 11:00 am and at 1:00, 2:30, and 4:00 pm). Corresponding measurements were made at 8:00 and 11:00 am and at 4:00 pm on 3 separate days to assess repeatability. Grouped data from 18 volunteer subjects were compared to the data of the test subject as well. Results Pachymetry accuracy on a calibrated standard was determined to be ±2 μm (standard deviation, n=12). Repeated measures on the subject demonstrated a mean standard deviation of 9.08 μm for 750 thickness data points across the central 7 mm of the cornea; peripheral measurement points exhibited progressively greater variability than at the apex (analysis of variance; P P r = 0.999). However, thickness values obtained at 8:00 am were significantly different across days ( t test; P r = 0.9996) with the grouped volunteer data. Conclusions These data show this system to be useful in corneal research and in clinical settings. The data confirm early morning pachymetry to be highly variable. Additionally, the data not only indicate a diurnal variation of corneal hydration over time, but also imply the presence of a diurnal-based hydration gradient across the peripheral cornea, both of which can have significance for PRK, since excimer tissue ablation effectiveness is influenced by tissue hydration.
Chapter 4 – The Triggering of Events

We discuss the representation of triggered events in the event calculus. A triggered event is an event that occurs when a particular condition becomes true. An example of a triggered event is a ball bouncing off of a wall when it reaches the wall. We also discuss triggered fluents.
Thermodynamic Hydricity of Transition Metal Hydrides

Transition metal hydrides play a critical role in stoichiometric and catalytic transformations. Knowledge of free energies for cleaving metal hydride bonds enables the prediction of chemical reactivity, such as for the bond-forming and bond-breaking events that occur in a catalytic reaction. Thermodynamic hydricity is the free energy required to cleave an M–H bond to generate a hydride ion (H–). Three primary methods have been developed for hydricity determination: the hydride transfer method establishes hydride transfer equilibrium with a hydride donor/acceptor pair of known hydricity, the H2 heterolysis method involves measuring the equilibrium of heterolytic cleavage of H2 in the presence of a base, and the potential–pKa method considers stepwise transfer of a proton and two electrons to give a net hydride transfer. Using these methods, over 100 thermodynamic hydricity values for transition metal hydrides have been determined in acetonitrile or water. In acetonitrile, the hydricity of metal hydrides sp...
The Day the Liberals Won

Austere describes the upbringing of Kenneth Boulding. In his words, where he grew up would probably be considered a slum by current standards. His parents were both from working-class families. He never shied away from this characterization. He embraced his family’s working-class roots and was always sympathetic to the struggles of that class. His childhood home at Four Seymour Street was in the middle of Liverpool, England, which, in the early twentieth century, was working-class cosmopolitan. This was endearing in many ways to Boulding. His neighborhood had Jews, Belgians, Irish, and a black family. He believed that this exposure to diversity trained him well for the American melting pot he would enter early in his professional life. There was no doubt why he felt at home in America. It both suited his personality and reminded him of home. Before delving into the specifics on Boulding’s life, it is necessary to better understand his family background—to dig into the roots of his family tree and see what genetic commingling led to his life.
Lessons from Mayan Astronomy

The Mayan culture collected exquisite astronomical data for over a millennium. However, it failed to come up with the breakthrough ideas of modern astronomy because the data was analyzed within a mythological culture of astrology that rested upon false but mathematically sophisticated theories about the Universe. Have we learned the necessary lessons to prevent our current scientific culture from resembling Mayan Astronomy? Clearly, data collection by itself is not a guarantee for good science as commonly assumed by funding agencies. A vibrant scientific culture should cultivate multiple approaches to analyzing existing data and to collecting new data.
INAM2: InfiniBand Network Analysis and Monitoring with MPI

Modern high-end computing is being driven by the tight integration of several hardware and software components. On the hardware front, there are the multi-/many-core architectures (including accelerators and co-processors) and high-end interconnects like InfiniBand that are continually pushing the envelope of raw performance. On the software side, there are several high performance implementations of popular parallel programming models that are designed to take advantage of the high-end features offered by the hardware components and deliver multi-petaflop level performance to end applications. Together, these components allow scientists and engineers to tackle grand challenge problems in their respective domains.
A dynamic mode of mitotic bookmarking by transcription factors

During mitosis, transcription is shut off, chromatin condenses, and most transcription factors (TFs) are reported to be excluded from chromosomes. How do daughter cells re-establish the original transcription program? Recent discoveries that a select set of TFs remain bound on mitotic chromosomes suggest a potential mechanism for maintaining transcriptional programs through the cell cycle termed mitotic bookmarking. Here we report instead that many TFs remain associated with chromosomes in mouse embryonic stem cells, and that the exclusion previously described is largely a fixation artifact. In particular, most TFs we tested are significantly enriched on mitotic chromosomes. Studies with Sox2 reveal that this mitotic interaction is more dynamic than in interphase and is facilitated by both DNA binding and nuclear import. Furthermore, this dynamic mode results from lack of transcriptional activation rather than decreased accessibility of underlying DNA sequences in mitosis. The nature of the cross-linking artifact prompts careful re-examination of the role of TFs in mitotic bookmarking.
The Cost and Benefit of Listeria Monocytogenes Food Safety Measures

The objectives of this study were to evaluate economic techniques used to determine the cost and benefit of Listeria monocytogenes control and to estimate the economic optimum of L. monocytogenes food safety measures. The level of food safety measures is optimal if marginal benefit and marginal cost equate. Estimates of benefit and cost of L. monocytogenes food safety measures, from available published literature, are derived from different methods of economic analysis (willingness to pay, cost of illness, cost function, and event study methods). The estimated annual benefit and cost of L. monocytogenes food safety measures range from $2.3 billion to $22 billion and from $.01 billion to $2.4 billion, respectively. The estimated marginal benefit exceeds the estimated marginal cost, which implies that more food safety measures are warranted before the optimal level of L. monocytogenes food safety can be reached. However, due to considerable lack of data, the optimal level of L. monocytogenes food safety measures could not be estimated. When better data become available, this study can serve as a template for estimating the optimal level of food safety. The understanding of the economic optimum of food safety level will contribute to designing a control program that is economical and acceptable for US society.
Query-Focused Extractive Video Summarization

Video data is explosively growing. As a result of the “big video data”, intelligent algorithms for automatic video summarization have (re-)emerged as a pressing need. We develop a probabilistic model, Sequential and Hierarchical Determinantal Point Process (SH-DPP), for query-focused extractive video summarization. Given a user query and a long video sequence, our algorithm returns a summary by selecting key shots from the video. The decision to include a shot in the summary depends on the shot’s relevance to the user query and importance in the context of the video, jointly. We verify our approach on two densely annotated video datasets. The query-focused video summarization is particularly useful for search engines, e.g., to display snippets of videos.
Generative Visual Manipulation on the Natural Image Manifold

Realistic image manipulation is challenging because it requires modifying the image appearance in a user-controlled way, while preserving the realism of the result. Unless the user has considerable artistic skill, it is easy to “fall off” the manifold of natural images while editing. In this paper, we propose to learn the natural image manifold directly from data using a generative adversarial neural network. We then define a class of image editing operations, and constrain their output to lie on that learned manifold at all times. The model automatically adjusts the output keeping all edits as realistic as possible. All our manipulations are expressed in terms of constrained optimization and are applied in near-real time. We evaluate our algorithm on the task of realistic photo manipulation of shape and color. The presented method can further be used for changing one image to look like the other, as well as generating novel imagery from scratch based on user’s scribbles.
THE EFFECT OF TGF-Β RECEPTOR INHIBITION AND ACUTE EXERCISE ON RAT ACHILLES TENDON COLLAGEN

Introduction Exercise increases tendon collagen synthesis and cross-link formation. Exercise also increases the expression of TGF-β 1 . TGF-β 1 may contribute to the upregulation of tendon collagen synthesis during exercise, but this relationship has not been established in vivo. The purpose of this study was to evaluate the effects of TGF-β 1 receptor inhibition on tendon collagen. Materials and Methods Male Wistar rats were divided into sedentary (SED, n = 9) or exercised (RUN, n=15) groups. Exercised animals completed four days of treadmill exercise (60 minutes/days). The peritendinous space of one Achilles tendon was injected with LY-364947 (ALK5 inhibitor; INHIB) while the opposite leg was injected with a vehicle (SHAM). Injections were given daily after each exercise bout. ERK and Smad 2/3 phosphorylation was evaluated by Western blotting. Collagen I and III gene expression were evaluated via qRT-PCR. Tendon hydroxyproline and hydroxylyslpyridinoline (HP) cross-linking were assayed via HPLC. A longitudinal section of tendon was stained with H&E for evaluation of cell numbers and fibril organization. Results Phosphorylation of ERK increased by 2.5-fold in both legs given LY-364947 (p 0.05). Smad 3 phosphorylation was reduced (p 1 receptor inhibition or exercise (p>0.05). Collagen content was not altered by either exercise or LY-364947 (p>0.05). HP cross-linking was 3-fold lower in the RUN-INHIB when compared to the RUN-SHAM tendon (p 2 , RUN: 10.3 cell/100 μm 2 ) but was not influenced by TGF-β 1 receptor inhibition (p>0.05). Fiber structure scores were 45% lower (p Discussion The changes in ERK and Smad phosphorylation suggest that LY-364947 was effective at altering TGF-β 1 signaling. Our data suggest that neither acute exercise nor TGF-β 1 receptor inhibition altered collagen gene expression. In contrast, TGF-β 1 appears to be important for regulating Achilles tendon cross-link formation during exercise training and inhibition of TGF-β 1 impacts fiber structure.
US Navy Power Transformer Sizing Requirements Using Probabilistic Analysis

Sizing power transformers in US Navy ships is an issue that surfaced in the design of a new amphibious assault ship. Previous methods averaged the power output from generators over each transformer and calculated load based on a demand factor curve. This technique is not accurate enough in the contract design stages or for zonal architectures since it artificially averages the electrical loads. The proposed methodology uses a systems engineering approach, applying a probabilistic (Monte Carlo) analysis of the electrical loads at each transformer, based on the electrical load analysis (ELA). This methodology will allow the designer to incorporate risk mitigation into a radial or zonal electrical system design to verify adequacy and reduce cost through probability-based transformer sizing.
The international effect of managerial social capital on the cost of equity

Abstract We examine the effect of managerial social capital on the firm's cost of equity capital. We argue that social ties alleviate information asymmetry and agency problems, which in turn leads to a decrease in the cost of equity. Using a large panel of companies from 52 countries over the period 1999–2012, we document that social capital inversely affects the cost of equity. Our evidence suggests that the association between social capital and the cost of equity capital is stronger in underdeveloped financial markets and those characterized by weak legal protection. The marginal effect of social capital is also stronger for constrained firms with profitable investment opportunities. Our results are robust to alternative model specifications and tests for endogeneity.
Characterizing the effective bandwidth of tri-stable energy harvesters

Abstract Recently, it has been shown that nonlinear vibratory energy harvesters possessing a tri-stable potential function are capable of harvesting energy efficiently over a wider range of frequencies in comparison to harvesters with a double-well potential function. However, the effect of the design parameters of the harvester on the dynamic response and the effective bandwidth of such devices remains uninvestigated. To fill this void, this paper establishes an analytical approach to characterize the effective frequency bandwidth of harvesters that possess a hexic potential energy function. To achieve this goal, the method of multiple scales is utilized to construct analytical solutions describing the amplitude and stability of the intra- and inter-well dynamics of the harvester. Using these solutions, critical bifurcations in the parameter's space are identified and used to define an effective frequency bandwidth of the harvester. The influence of the electric parameters, namely, the time constant ratio (ratio between the period of the mechanical system and the time constant of the harvesting circuit) and the electromechanical coupling, on the effective frequency bandwidth is analyzed. Experimental studies performed on the harvester are presented to validate some of the theoretical findings.
An Ancient Fecundability-Associated Polymorphism Switches a Repressor into an Enhancer of Endometrial TAP2 Expression

Variation in female reproductive traits, such as fertility, fecundity, and fecundability, is heritable in humans, but identifying and functionally characterizing genetic variants associated with these traits has been challenging. Here, we explore the functional significance and evolutionary history of a T/C polymorphism of SNP rs2071473, which we have previously shown is an eQTL for TAP2 and significantly associated with fecundability (time to pregnancy). We replicated the association between the rs2071473 genotype and TAP2 expression by using GTEx data and demonstrated that TAP2 is expressed by decidual stromal cells at the maternal-fetal interface. Next, we showed that rs2071473 is located within a progesterone-responsive cis-regulatory element that functions as a repressor with the T allele and an enhancer with the C allele. Remarkably, we found that this polymorphism arose before the divergence of modern and archaic humans, segregates at intermediate to high frequencies across human populations, and has genetic signatures of long-term balancing selection. This variant has also previously been identified in genome-wide association studies of immune-related disease, suggesting that both alleles are maintained as a result of antagonistic pleiotropy.
Social ties and checkin sites: connections and latent structures in location-based social networks

Location-based social networks integrate location-based facilities with social connectivity for delivering a variety of services, enhancing user experience, emergency/disaster management, and streamlining business processes. A number of recent research efforts have studied relationships between geolocation and social connectivity, social connectivity and preferences, and node attributes and strength of social ties. These efforts have successfully demonstrated prediction of various attributes based on social connectivity, mobility, dynamic checkin information, etc., including prediction of user location as well as future checkin locations. In this paper, we study the relationship between shared checkin locations and the structure and nature of social ties. We argue that typical LSBNs are in fact composed of layers of networks of varying structure and function and that it is possible to deconcolve these networks through effective statistical analysis of shared checkins. In this context, we pose and validate the following hypotheses: (1) A large number of shared checkins imply social connectivity; however, social connectivity does not imply statistically large number of shared checkins; (2) entities in social ties that share a large number of checkins tend to be strongly clustered. We hypothesize that such strong ties (e.g., family ties and friendships) carry higher influence compared to weaker ties (mere acquaintances) in the social network; (3) social ties that have statistically fewer shared checkins (weak ties) tend to be less clustered than the underlying (baseline) network. We hypothesize that such ties (e.g., professional ties, friends of friends, and acquaintances) carry less influence; and (4) social ties that have statistically large number of shared checkins (strong ties) tend to be relatively more dynamic when compared to weak ties over a period of time. We present statistical models and validate our hypotheses on real datasets. Our conclusions can significantly enhance flow of information and influence in the network by suitably leveraging the distinct relationships captured in the deconvolved networks.
Low frequency noise - based monitoring of the effects of RF and DC stress on AlGaN/GaN MODFETs

The impact of RF and DC stress on AlGaN/GaN MODFETs is investigated by means of DC and low frequency noise measurements. The devices present significant changes in the drain noise current level after DC and RF stress and manifest trends that are almost independent of type of stress. RF and DC stress are found to be differentiable only through the positive shift in the pinch-off voltage, which takes place only after RF stress. Although the findings of this study support those of previously reported investigations in terms of considering the drain access region responsible for current degradation, they demonstrate that RF stress not only causes degradation of drain current but also of other device characteristics.
RhoA/Rho Kinase Mediates Neuronal Death Through Regulating cPLA2 Activation.

Activation of RhoA/Rho kinase leads to growth cone collapse and neurite retraction. Although RhoA/Rho kinase inhibition has been shown to improve axon regeneration, remyelination and functional recovery, its role in neuronal cell death remains unclear. To determine whether RhoA/Rho kinase played a role in neuronal death after injury, we investigated the relationship between RhoA/Rho kinase and cytosolic phospholipase A2 (cPLA2), a lipase that mediates inflammation and cell death, using an in vitro neuronal death model and an in vivo contusive spinal cord injury model performed at the 10th thoracic (T10) vertebral level. We found that co-administration of TNF-α and glutamate induced spinal neuron death, and activation of RhoA, Rho kinase and cPLA2. Inhibition of RhoA, Rho kinase and cPLA2 significantly reduced TNF-α/glutamate-induced cell death by 33, 52 and 43 %, respectively (p < 0.001). Inhibition of RhoA and Rho kinase also significantly downregulated cPLA2 activation by 66 and 60 %, respectively (p < 0.01). Furthermore, inhibition of RhoA and Rho kinase reduced the release of arachidonic acid, a downstream substrate of cPLA2. The immunofluorescence staining showed that ROCK1 or ROCK2, two isoforms of Rho kinase, was co-localized with cPLA2 in neuronal cytoplasm. Interestingly, co-immunoprecipitation (Co-IP) assay showed that ROCK1 or ROCK2 bonded directly with cPLA2 and phospho-cPLA2. When the Rho kinase inhibitor Y27632 was applied in mice with T10 contusion injury, it significantly decreased cPLA2 activation and expression and reduced injury-induced apoptosis at and close to the lesion site. Taken together, our results reveal a novel mechanism of RhoA/Rho kinase-mediated neuronal death through regulating cPLA2 activation.
Does Price Efficiency Increase with Trading Volume? Evidence of Nonlinearity and Power Laws in ETFs

Abstract Whether efficiency increases with increasing volume is an important issue that may illuminate trader strategies and distinguish between market theories. This relationship is tested using 124,236 daily observations comprising 68 large and liquid U.S. equity exchange traded funds (ETFs). ETFs have the advantage that efficiency can be measured in terms of the deviation between the trading price and the underlying net asset value that is reported each day. Our findings support the hypothesis that the relationship between volume and efficiency is nonlinear. Indeed, efficiency increases as volume increases from low to moderately high levels, but then decreases as volume increases further. The first part tends to support the idea that higher volume simply facilitates transactions and maintains efficiency, while the latter part, i.e., even higher volumes, supports the ansatz that increased volume is associated with increased speculation that ignores valuation and decreases efficiency. The results are consistent with the hypothesis that valuation is only part of the motivation for traders. Our methodology accounts for fund heterogeneity and contemporaneous correlations. Similar results are obtained when daily price volatility is introduced as an additional independent variable.
Suzuki-Miyaura cross-coupling optimization enabled by automated feedback

An automated, droplet-flow microfluidic system explores and optimizes Pd-catalyzed Suzuki–Miyaura cross-coupling reactions. A smart optimal DoE-based algorithm is implemented to increase the turnover number and yield of the catalytic system considering both discrete variables—palladacycle and ligand—and continuous variables—temperature, time, and loading—simultaneously. The use of feedback allows for experiments to be run with catalysts and under conditions more likely to produce an optimum; consequently complex reaction optimizations are completed within 96 experiments. Response surfaces predicting reaction performance near the optima are generated and validated. From the screening results, shared attributes of successful precatalysts are identified, leading to improved understanding of the influence of ligand selection upon transmetalation and oxidative addition in the reaction mechanism. Dialkylbiarylphosphine, trialkylphosphine, and bidentate ligands are assessed.
Evaluation of Hand⁻Dug Wells in Rural Haiti.

Water resources, especially safe, potable water, are limited for many Haitians. In areas where shallow groundwater is available, many household water needs such as laundry, bathing, and cooking are supplied by hand–dug wells. In order to better understand the water quality and prevalence of these household wells, 35 hand–dug wells were surveyed and sampled near the Hopital Albert Schweitzer in Deschapelles, Haiti. Water samples were collected and tested for fecal coliform and Escherichia coli using the IDEXX Colilert–18 method. Of the samples collected, 89 percent were determined unsafe to use as a drinking water source based on the World Health Organization standard of 1.0 colony–forming unit (cfu) E. coli per 100 mL. Sixty–six percent of the wells exceeded recreational/body contact standards for the state of Michigan (130 cfu/100 mL). Some of these wells were deemed suitable for conversion to a new well type called in situ filtration (ISF) wells. In situ filtration wells are installed with an internal sand filter pack, PVC casing, pump, and cap which seals the well from surface contamination and provides additional water treatment as water is pumped. Previous ISF installations have reduced E. coli to safe drinking water levels within 90 days.
Attaining whole-ecosystem warming using air and deep-soil heating methods with an elevated CO 2 atmosphere

Abstract. This paper describes the operational methods to achieve and measure both deep-soil heating (0–3 m) and whole-ecosystem warming (WEW) appropriate to the scale of tall-stature, high-carbon, boreal forest peatlands. The methods were developed to allow scientists to provide a plausible set of ecosystem-warming scenarios within which immediate and longer-term (1 decade) responses of organisms (microbes to trees) and ecosystem functions (carbon, water and nutrient cycles) could be measured. Elevated CO2 was also incorporated to test how temperature responses may be modified by atmospheric CO2 effects on carbon cycle processes. The WEW approach was successful in sustaining a wide range of aboveground and belowground temperature treatments (+0, +2.25, +4.5, +6.75 and +9 °C) in large 115 m2 open-topped enclosures with elevated CO2 treatments (+0 to +500 ppm). Air warming across the entire 10 enclosure study required ∼ 90 % of the total energy for WEW ranging from 64 283 mega Joules (MJ) d−1 during the warm season to 80 102 MJ d−1 during cold months. Soil warming across the study required only 1.3 to 1.9 % of the energy used ranging from 954 to 1782 MJ d−1 of energy in the warm and cold seasons, respectively. The residual energy was consumed by measurement and communication systems. Sustained temperature and elevated CO2 treatments were only constrained by occasional high external winds. This paper contrasts the in situ WEW method with closely related field-warming approaches using both aboveground (air or infrared heating) and belowground-warming methods. It also includes a full discussion of confounding factors that need to be considered carefully in the interpretation of experimental results. The WEW method combining aboveground and deep-soil heating approaches enables observations of future temperature conditions not available in the current observational record, and therefore provides a plausible glimpse of future environmental conditions.
The Predicates of Military Detention at Guantánamo: The Role of Individual Acts and Affiliations

The military detentions at Guantanamo have provoked intense controversy. Judges, legislators, and military officials disagree sharply about the scope of detention authority. To date, little is known about the granular determinants of decisions to transfer detainees from custody at the Cuban base or to prolong their detention. This article exploits a novel data set of classified documents disclosed by the Wikileaks organization to explore two questions now dividing officials, legislators, and judges. First, what are the detainee actions and affiliations that predict longer detentions? Second, what is the relationship between a determination that a detainee committed certain acts and the further inference of affiliation with a proscribed terrorist organization? These inquiries isolate both continuities and divergences from the law “on the books.”
A plane wave discontinuous Galerkin method with a Dirichlet-to-Neumann boundary condition for the scattering problem in acoustics

Abstract We consider the numerical solution of an acoustic scattering problem by the Plane Wave Discontinuous Galerkin Method (PWDG) in the exterior of a bounded domain in R 2 . In order to apply the PWDG method, we introduce an artificial boundary to truncate the domain, and we impose a non-local Dirichlet-to-Neumann (DtN) boundary condition on the artificial curve. To define the method, we introduce new consistent numerical fluxes that incorporate the truncated series of the DtN map. Error estimates with respect to the truncation order of the DtN map, and with respect to mesh width are derived. Numerical results suggest that the accuracy of the PWDG method for the acoustic scattering problem can be significantly improved by using DtN boundary conditions.
Linking microstructural evolution and macro-scale friction behavior in metals

A correlation is established between the macro-scale friction regimes of metals and a transition between two dominant atomistic mechanisms of deformation. Metals tend to exhibit bi-stable friction behavior—low and converging or high and diverging. These general trends in behavior are shown to be largely explained using a simplified model based on grain size evolution, as a function of contact stress and temperature, and are demonstrated for self-mated pure copper and gold sliding contacts. Specifically, the low-friction regime (where µ 0.5. We utilize a combination of experimental and computational methods to develop and validate the proposed structure–property relationship. This quantitative framework provides a shift from phenomenological to mechanistic and predictive fundamental understanding of friction for crystalline materials, including engineering alloys.
INFORMATION OPACITY AND FITCH BOND RATINGS

We examine the marginal impact of Fitch ratings on the at-issuance yields of industrial and utility bonds rated by Moody's and Standard & Poor's. We find that Fitch ratings reduce the yield premiums on information-opaque bonds by about 30%, or 15 basis points. The finding is robust even when a Fitch rating exactly equals the two major ratings or their average. The findings suggest that Fitch ratings are not redundant but bring additional information to investors. Increased competition in the rating industry enhances the information efficiency of the bond market, and the existence of smaller rating agencies is economically justified.
Agent-Based Modeling: A Guide for Social Psychologists

Agent-based modeling is a long-standing but underused method that allows researchers to simulate artificial worlds for hypothesis testing and theory building. Agent-based models (ABMs) offer unprecedented control and statistical power by allowing researchers to precisely specify the behavior of any number of agents and observe their interactions over time. ABMs are especially useful when investigating group behavior or evolutionary processes and can uniquely reveal nonlinear dynamics and emergence—the process whereby local interactions aggregate into often-surprising collective phenomena such as spatial segregation and relational homophily. We review several illustrative ABMs, describe the strengths and limitations of this method, and address two misconceptions about ABMs: reductionism and “you get out what you put in.” We also offer maxims for good and bad ABMs, give practical tips for beginner modelers, and include a list of resources and other models. We conclude with a seven-step guide to creating you...
The latest from the new Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory

Abstract The status of the new Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory (ORNL), which is slated to start its scientific program late in 1996 is discussed, as is the new experimental equipment which is being constructed at this facility. Information on the early scientific program is also given.
Quantitative Evaluation of Stabilization Policies in International Commodity Markets

commodity markets. The "commodity boom" of 1972-75, and the rapid rise in grain prices in 1973-74 generated political pressures in both developed and less developed countries (LDCs) for commodity market control. The 1974 World Food Conference in Rome had as one of its themes the establishment and management of international reserve stocks to stabilize grain markets and provide food security. The 1976 meetings of the United Nations Conference on Trade and Development (UNCTAD) in Nairobi were dominated by a proposal to introduce an integrated program for commodities (IPC). This program has as its central point the creation of an extensive series of international commodity agreements to act as market stabilizers. Such developments have stimulated the interest of economists, who have sought to examine the issues raised from both theoretical and empirical perspectives. The purpose of this paper is to discuss briefly the major approaches that have been adopted in the empirical analysis of stabilization policy, to identify their advantages and disadvantages, and to indicate some important analytical questions that arise in the modeling of instability. The primary focus is on agricultural commodities, but methods and problems discussed are not confined to these alone.
A new 500-kV ion source test stand for HIF

One of the most challenging aspects of ion beam driven inertial fusion energy is the reliable and efficient generation of low emittance, high current ion beams. The primary ion source requirements include a rise time of order 1-{micro}sec, a pulse width of at least 20-{micro}sec, a flattop ripple of less than 0.1% and a repetition rate of at least 5-HZ. Naturally, at such a repetition rate, the duty cycle of the source must be greater than 10{sup 8} pulses. Although these specifications do not appear to exceed the state-of-the-art for pulsed power, considerable effort remains to develop a suitable high current ion source. Therefore, we are constructing a 500-kV test stand specifically for studying various ion source concepts including surface, plasma and metal vapor arc. This paper will describe the test stand design specifications as well as the details of the various subsystems and components.
A microfabricated optically-pumped magnetic gradiometer.

We report on the development of a microfabricated atomic magnetic gradiometer based on optical spectroscopy of alkali atoms in the vapor phase. The gradiometer, which operates in the spin-exchange relaxation free regime, has a length of 60 mm and cross sectional diameter of 12 mm, and consists of two chip-scale atomic magnetometers which are interrogated by a common laser light. The sensor can measure differences in magnetic fields, over a 20 mm baseline, of 10 fT/ Hz1/2 at frequencies above 20 Hz. The maximum rejection of magnetic field noise is 1000 at 10 Hz. By use of a set of compensation coils wrapped around the sensor, we also measure the sensor sensitivity at several external bias field strengths up to 150 mG. This device is useful for applications that require both sensitive gradient field information and high common-mode noise cancellation.
Précis of Doing without Concepts

The study of concepts is in an odd state of disarray. Cognitive scientists working on categorization, induction, and reasoning have discovered a dazzling number of phenomena, but these findings have yet to be organized in a coherent theoretical framework. In addition, after 20 years of controversy, there is little sign that philosophers and psychologists are converging toward an agreement about the very nature of concepts. Doing without Concepts attempts to remedy this state of affairs. In this precis, I review the main points and arguments developed at greater length in Doing without Concepts, and I conclude that abandoning the very notion of concept is probably required to remedy the state of disarray of the current study of concepts.
BER performance analysis of interference-limited BPSK cooperative communication systems with cochannel interference in Nakagami-m fading channels

The average bit error rate (BER) performance of interference-limited dual-hop decode-and-forward (DF) cooperative systems with cochannel interference (CCI) at both relay (R) and destination (D) nodes is analyzed in Nakagami-m fading channels with arbitrary (integer as well as non-integer) values of m. This channel condition is assumed for both the desired signal as well as cochannel interfering signals. In addition, the practical case of unequal average fading powers between the two hops is assumed in this analysis. Accurate closed-form approximate expressions for the BER performance of binary phase shift keying (BPSK) modulation scheme are derived. The analysis assumes an arbitrary number of independent and non-identically distributed (i.n.i.d.) interfering signals at both R and D nodes. The derived closed-form expressions are simple and easy to evaluate. We verify the accuracy of the derived expressions using Monte-Carlo Simulation.
Epstein–Barr Virus (EBV)

Epstein–Barr virus (EBV) is a well-known cause of neurological disease. The most recognized form of EBV infection is infectious mononucleosis (IM), the primary EBV infection that occurs in adolescents and young adults. Neurological complications are seen in 1–5% of children with IM, which include meningoencephalitis, transverse myelitis, Guillain–Barre syndrome, cranial neuropathy, and acute psychosis. Generally the neurological complications associated with acute EBV infection resolve without permanent sequelae. Recently, a more ominous association has been recognized between symptomatic IM in adolescence and subsequent development of multiple sclerosis (MS) in later adulthood. As EBV deoxyribonucleic acid (DNA) is not found in the cerebrospinal fluid (CSF) of MS patients, EBV infection does not lead directly to MS. Instead, symptomatic IM appears to identify a subpopulation at risk for subsequent development of MS.
Do consumers value price transparency

We examine the role of price transparency in consumer preferences and demand. We assemble a detailed dataset on the driving school industry in Portugal to quantify how firms present the price of the course of instruction, and its individual components, to potential students. Our unique data allows us to estimate a structural model of school choice and measure the impact of varying levels of price information on demand. The results show that consumers are willing to pay a significant amount for price transparency, on average 11% of the service price, and that consumer demographics drive heterogeneous preferences for transparency.
Designing an internet intervention for emerging adults who experience troubled relationships

This article describes how the Internet Intervention Model (IIM) was used as an organizing framework to design a theoretically based Internet intervention for emerging adults who experience troubled intimate partner relationships. In the design process, the team addressed six fundamental questions related to the several components of the IIM. Decisions made regarding the design of the intervention based on the six questions are described. We focus in particular on how the intervention is based on the Theory of Emerging Adulthood and the Theory of Narrative Identity.
METAL-METAL ARTICULATIONS: AN INTERVENTION ALGORITHM

The contemporary metal-on-metal (MoM) bearings were reintroduced due to their lower volumetric wear rates in comparison to conventional metal-on-polyethylene bearings. This has the potential to substantially reduce wear-induced osteolysis as the major cause of failure and greater implant stability with the use of large femoral heads. It has been estimated that since 1996 more than 1,000,000 MoM articular couples have been implanted worldwide. However, with increasing clinical experience, the national joint registries have recently reported the failure rate of THA with MoM bearings to be 2–3 fold higher than contemporary THA with non-metal-on-metal bearings. Moreover, adverse periprosthetic tissue reactions have emerged as an important reason for failure in MoM patients. A painful MoM hip arthroplasty has various intrinsic and extrinsic causes. As in all painful THA, a thorough clinical history, a detailed physical examination, as well as radiographic and laboratory tests are essential to delineate potential cause(s) of pain in patients with MoM hip arthroplasty. While specialised tests such as metal ion analysis are useful modalities for assessing MoM hip arthroplasty, over-reliance on any single investigative tool in the clinical decision-making process should be avoided. There should be a low threshold to perform a systematic evaluation of patients with MoM hip arthroplasty as early recognition and diagnosis will facilitate the initiation of appropriate treatment prior to significant adverse biological reactions. A systematic risk stratification recommendation, for multiple modes of failure including adverse local tissue reactions, based on the currently available evidence will be presented to optimise management.
Two dynamic regimes in the human gut microbiome

The gut microbiome is a dynamic system that changes with host development, health, behavior, diet, and microbe-microbe interactions. Prior work on gut microbial time series has largely focused on autoregressive models (e.g. Lotka-Volterra). However, we show that most of the variance in microbial time series is non-autoregressive. In addition, we show how community state-clustering is flawed when it comes to characterizing within-host dynamics and that more continuous methods are required. Most organisms exhibited stable, mean-reverting behavior suggestive of fixed carrying capacities and abundant taxa were largely shared across individuals. This mean-reverting behavior allowed us to apply sparse vector autoregression (sVAR)-a multivariate method developed for econometrics-to model the autoregressive component of gut community dynamics. We find a strong phylogenetic signal in the non-autoregressive co-variance from our sVAR model residuals, which suggests niche filtering. We show how changes in diet are also non-autoregressive and that Operational Taxonomic Units strongly correlated with dietary variables have much less of an autoregressive component to their variance, which suggests that diet is a major driver of microbial dynamics. Autoregressive variance appears to be driven by multi-day recovery from frequent facultative anaerobe blooms, which may be driven by fluctuations in luminal redox. Overall, we identify two dynamic regimes within the human gut microbiota: one likely driven by external environmental fluctuations, and the other by internal processes.
LeakSemantic: Identifying abnormal sensitive network transmissions in mobile applications

Mobile applications (apps) often transmit sensitive data through network with various intentions. Some transmissions are needed to fulfill the app's functionalities. However, transmissions with malicious receivers may lead to privacy leakage and tend to behave stealthily to evade detection. The problem is twofold: how does one unveil sensitive transmissions in mobile apps, and given a sensitive transmission, how does one determine if it is legitimate? In this paper, we propose LeakSemantic, a framework that can automatically locate abnormal sensitive network transmissions from mobile apps. LeakSemantic consists of a hybrid program analysis component and a machine learning component. Our program analysis component combines static analysis and dynamic analysis to precisely identify sensitive transmissions. Compared to existing taint analysis approaches, LeakSemantic achieves better accuracy with fewer false positives and is able to collect runtime data such as network traffic for each transmission. Based on features derived from the runtime data, machine learning classifiers are built to further differentiate between the legal and illegal disclosures. Experiments show that LeakSemantic achieves 91% accuracy on 2279 sensitive connections from 1404 apps.
Welcome home in a crisis: Effects of return migration on the non-migrants' wages and employment

Abstract The recent economic depression in Greece hit the population of Albanian migrants in Greece particularly hard, spurring a wave of return migration that increased the Albanian labor force by 5% in less than four years, between 2011 and 2014. We study how this return migration affected the employment chances and earnings of Albanians who never migrated. We find positive effects on the wages of low-skilled non-migrants and overall positive effects on employment. The gains partially offset the sharp drop in remittances in the observed period. An important part of the employment gains are concentrated in the agricultural sector, where most return migrants engage in self-employment and entrepreneurship. Businesses run by return migrants seem to pull Albanians from non-participation, unemployment and subsistence agriculture into commercial agriculture.
Conformational Nonequilibrium Enzyme Kinetics: Generalized Michaelis–Menten Equation

In a conformational nonequilibrium steady state (cNESS), enzyme turnover is modulated by the underlying conformational dynamics. On the basis of a discrete kinetic network model, we use an integrated probability flux balance method to derive the cNESS turnover rate for a conformation-modulated enzymatic reaction. The traditional Michaelis–Menten (MM) rate equation is extended to a generalized form, which includes non-MM corrections induced by conformational population currents within combined cyclic kinetic loops. When conformational detailed balance is satisfied, the turnover rate reduces to the MM functional form, explaining its general validity. For the first time, a one-to-one correspondence is established between non-MM terms and combined cyclic loops with unbalanced conformational currents. Cooperativity resulting from nonequilibrium conformational dynamics can be achieved in enzymatic reactions, and we provide a novel, rigorous means of predicting and characterizing such behavior. Our generalized M...
Second- and Third-Order Elastic Constants of Aluminum and Lead

The second- and third-order elastic constants of Al and Pb are calculated as the second and third derivatives of the binding energy with respect to the finite deformation parameter. The binding energy is derived from a local pseudopotential by use of second-order perturbation theory. It is shown that the binding energy satisfied not only the diagonal equilibrium condition, but also the off-diagonal equilibrium condition, i.e., the first derivative of the binding energy with respect to a volume change as well as with respect to shear deformations is zero. Accordingly, the present method of calculation is based on a stable lattice model. The results of the present calculation of the third-order elastic constants of Al are found to be in qualitative agreement with the experimental data obtained by Thomas. The complete experimental set of the third-order elastic constants of Pb is not yet available; however, the calculated pressure derivatives of the second-order elastic constants are in agreement with the experimental data of Miller and Schuele. On the other hand, the method initiated by Leigh, which is based on a rigid-band model, cannot reproduce the experimentally observed third-order elastic constants of Al. This is an indication that the pseudopotential method is to be preferred to the rigid-band method as far as the calculation of second- and third-order elastic constants is concerned.