cssi/SciSciGPT-SciSciNet huggingface dataset:
Spatially-guided non-local mean filter for denoising of clinical whole-body PET images

A novel spatially-guided non-local mean (SG-NLM) filter for denoising whole-body PET images is proposed. In this approach, PET images are first clustered into a number of regions with homogeneous uptake and a Bayesian framework exploited to estimate the noise level for automatic parameter setting. Then, instead of defining a search window to find similar patches (as in conventional NLM), only patches belonging to the same regions are collected and compared to facilitate the patch searching process. The SG-NLM filter was compared to conventional post-reconstruction Gaussian and NLM filters. Experimental measurements using the Jaszczak phantom and clinical whole-body PET/CT studies were used to evaluate the performance of the proposed approach. In the Jaszczak phantom, the signal to noise ratio (SNR) improved from 26.5 when using Gaussian smoothing to 29.9 and 30.7 (averaged over all six spheres in the Jaszczak phantom) using the NLM and SG-NLM filters, respectively. The clinical studies further demonstrated the superior performance of SG-NLM method by leading to higher SNR while yielding a quantification change in malignant lesions of -2.4% compared to -11.7% and -2.9% achieved using Gaussi-an and conventional NLM filters, respectively. The SG-NLM proved to improve the contrast, SNR and quantitative accuracy compared to Gaussian and NLM approaches, and can be utilized as an alternative post-reconstruction filter in clinical whole-body PET/CT imaging.
Partisanship, sexuality, and perceptions of candidates

Cultural debates over gay rights have prompted a great deal of scholarship assessing the nature and resiliency of citizen attitudes toward homosexuality in American political life. We posit, howeve...
Effective Care Practices in Patients Receiving Prolonged Mechanical Ventilation. An Ethnographic Study

Rationale: Patients receiving prolonged mechanical ventilation experience low survival rates and incur high healthcare costs. However, little is known about how to optimally organize and manage their care.Objectives: To identify a set of effective care practices for patients receiving prolonged mechanical ventilation.Methods: We performed a focused ethnographic evaluation at eight long-term acute care hospitals in the United States ranking in either the lowest or highest quartile of risk-adjusted mortality in at least four of the five years between 2007 and 2011.Measurements and Main Results: We conducted 329 hours of direct observation, 196 interviews, and 39 episodes of job shadowing. Data were analyzed using thematic content analysis and a positive-negative deviance approach. We found that high- and low-performing hospitals differed substantially in their approach to care. High-performing hospitals actively promoted interdisciplinary communication and coordination using a range of organizational practices, including factors related to leadership (e.g., leaders who communicate a culture of quality improvement), staffing (e.g., lower nurse-to-patient ratios and ready availability of psychologists and spiritual care providers), care protocols (e.g., specific yet flexible respiratory therapy-driven weaning protocols), team meetings (e.g., interdisciplinary meetings that include direct care providers), and the physical plant (e.g., large workstations that allow groups to interact). These practices were believed to facilitate care that is simultaneously goal directed and responsive to individual patient needs, leading to more successful liberation from mechanical ventilation and improved survival.Conclusions: High-performing long-term acute care hospitals employ several organizational practices that may be helpful in improving care for patients receiving prolonged mechanical ventilation.
The Question Every Project Team Should Answer

Many aspects of project management are well understood, but one key factor is frequently overlooked: A significant number of projects fail to meet their business objectives because they were launched without a clearly articulated purpose. In more than 20 years of consulting with hundreds of teams, the authors have found that lack of a focused why statement is perhaps the most common reason projects fail. Without a solid why, it is more difficult for a team to maintain its internal momentum and keep higher-level managers interested in the project. Projects are launched without a clear why statement for a number of reasons. Sometimes, the group feels pressured to do something, anything, right away. On other occasions, decision makers are unwilling to engage in discussions that might involve conflict or expose hidden agendas. Finally, a failure of imagination can lead to shortsighted reasoning, as the organization chooses a familiar course of action before realizing it wont actually address the problem that needs to be solved. The authors contend that a project team can improve its chances of success by considering four dimensions associated with clear why statements: 1. Identity requires that the core problem be clearly articulated. 2. Location is the second dimension of an effective why statement and answers the question, Where do we see the problem? 3. Timing involves specifying when the problem occurs, when it began and how long it is likely to persist if no action is taken. 4. Magnitude speaks to the significance and scale of the issue and answers the question, How big is the problem or gap in measurable terms? The four dimensions of a why statement provide a structured description of the business gap that drives the project. A why statement should be developed early in the gestation of a project before significant resources are misdirected toward a poorly defined venture that misses the mark, or worse, solves the wrong problem.
Stimulation by 6-azauridine of de novo pyrimidine biosynthesis in BHK 165-23 cells.

The undine analog 6-azauridine is taken up by cells and phosphorylated to 6-azaUMP which acts on the OMP decarboxylase of the UMP synthetase, thus inhibiting de novo biosynthesis of pyrimidine nucleotides1. Upon 6-azauridine treatment, significant increases in the level of the de novo pyrimidine biosynthesis intermediates and derivatives, orotic acid and orotidine, have been noted in tissue culture cells, the tissues and urine of mice, and the urine of humans2, 3, 4, 5, 6, 7, 8. The accumulation of the intermediates has been explained by the inhibition of the decarboxylation of OMP by 6-azaUMP. However, Tatibana et al showed that 6-azauridine treatment of mouse spleen cells also stimulated carbamyl phosphate synthesis3. They suggested that an increase in the concentration of PRPP was the most likely regulatory factor stimulating de novo pyrimidine biosynthesis. Alternatively, with a decrease in the nucleotide pool caused by 6-azauridine treatment8, the feedback inhibition on the carbamyl phosphate synthetase could be released resulting in enhanced de novo pyrimidine biosynthesis.
Radiology-guided percutaneous approach is superior to EUS for performing liver biopsies

We read with interest the study titled ‘Radiology-guided percutaneous approach is superior to EUS for performing liver biopsies’ by Bang et al .1 Authors conclude that radiology-guided percutaneous liver biopsy is superior based on comparing the proportion of optimal samples obtained, defined as a sample with length of ≥25 mm and complete portal tracts (CPTs) of ≥11. Further evaluation of the results in this study shows no significant difference between the two methods regarding the number of CPTs, but a significantly higher sample length in the percutaneous group. We propose that the results and the conclusions of the study are misleading and not generalisable to clinical practice. The main flaw of this study is the use of a suboptimal technique for performing the endoscopic ultrasound …
Molecular identification of Hymenolepis spp. in diarrheal patients using RFLP/PCR technique for 18SS ribosomal RNA gene

Abstract Hymenolepis nana and Hymenolepis diminuta are worldwide zoonotic helminthes. Rats and mice are the common reservoir host of these tape worms, because of the less studies of the hymenolepidid genus in Iraqi peoples, this study was aimed to demonstrate the prevalence and genetic differentiation of H. nana and H. diminuta in diarrheal patients. A total 654 fecal samples were collected from patients severing from gastrointestinal symptoms. All the samples were examined by microscopy using wet mount methods to investigate the worms' eggs and the result shows 126/654 (19.2%) were positive for Hymenolepis spp. Also genetic analysis by RFLP/PCR using the common restriction enzymes Bg1I and BanII to differentiate between Hymenolepis nana and Hymenolepis diminuta, all the positive microscopically samples (126) were gave a band in 980 bp in their 18SS rRNA genes while “the two species of genus Hymenolepis se recognized in their 18SS rRNA genes dissolve with Bg1I and BanII restriction endonucleases”. It's understandable showed that Bg/I and Ban/II restriction enzymes may be used as an enzymes markers for Hymenolepis nana and Hymenolepis diminuta when the enzymes exceptionally fragmented the 18SS rRNA gene. Aim of the study This study was aimed to demonstrate the prevalence and genetic differentiation of H. nana and H. diminuta in diarrheal patients from Iraqi peoples.
Dual-flow continuous culture fermentor system updated to decrease variance of estimates of digestibility of neutral detergent fiber

ABSTRACT Objective Dual-flow continuous culture (DFCC) fermentor systems have been historically used to simulate ruminant fermentation, but one most commonly used system was discontinued by the manufacturer. In response, modifications were made to construct new cost-effective units. Our objective was to evaluate the modifications relative to the original DFCC fermentors. Our hypothesis was that experiments using newly modified DFCC units would have decreased variance estimates for common dependent variables: nutrient digestibilities, VFA production, and bacterial N flow. Materials and Methods To evaluate impeller orientation, DFCC fermentors were randomized to either clockwise or counterclockwise fan blades on a counterclockwise-rotating motor. Fermentors (n = 8) were fed 37.2 g of DM of a pelleted 50:50 alfalfa:concentrate diet and run for 11 d with 7 d of adaptation and 4 d of sampling. To evaluate variance estimates, data were accumulated from 4 published fermentor experiments (n = 68) using original fermentors (The Virtis Company) and 2 fermentor experiments using modified DFCC units (n = 42). An F-test was conducted on the modified:original variance ratio, and a significant decrease in variance was declared at P Results and Discussion Impeller orientation decreased NDF digestibility in the clockwise rotation, whereas ADF digestibility was not affected. The modified DFCC system decreased variance of NDF and nonstructural carbohydrate digestibility. Variances of other measures were unaffected by the new system. Implications and Applications These data indicate the potential for the modified DFCC to primarily improve reliability of fiber digestibility, but more work may be needed to reduce variance of concentration-based fermentation parameters.
Emergence of the Electroweak Scale from Fractal Spacetime

As of today, neither one of the mass generation mechanisms of the Standard Model (SM) can convincingly explain the source of the electroweak scale. In this brief report we argue that the onset of fractal spacetime near the electroweak interaction provides a natural motivation for the emergence of this scale.
Internet Growth and Economic Theory

This paper focuses on economic implications of the Internet. We argue that some effects of the Internet can be understood within the context of traditional economics. Specifically, the Internet has the potential to make market more contestable and hence more competitive. Policy issues are also discussed.
A Real-Time Large-Sample Single Fiber Electromyographic Jitter Analyzer for Clinical Applications Using an Inexpensive Microcomputer

Abstract Single fiber electromyography (SFEMG) can be used as a means for evaluation of neural control of muscular contractions. It is also a clinical aid for the diagnosis of neuromuscular disorders. The information needed for this analysis includes jitter and percentage of blocking. Jitter is a measure of the variability between the arrival of action potentials from two muscle fibers belonging to the same motor unit. Blocking is the situation when one of the action potentials is missing. The use of this clinical tool is presently hampered by the great amount of time required for the collection and processing of the data. A system consisting of a popular Apple II microcomputer, a television monitor, a cassette player (or a disk drive), and a simple interface which fits in one of the Apple's eight I/O slots is developed for simplifying this test. The program analyzes SFEMG jitter based on up to 500 data samples per motor unit and up to 24 motor units per run. It prints the statistics for the neural control of the muscle, plots the histogram of the results, and compares it with normal values for easy diagnosis of disorders. The system is presently in clinical use at Ohio State University.
Luria, Alexander Romanovich

Alexander Romanovich Luria (1902–77) was a leading neuropsychologist of the twentieth century whose impact on clinical neuroscience remains significant. Best known for studying Russian soldiers in World War II with penetrating traumatic brain injury, Luria made many important contributions to the assessment of cognitive deficits in relation to acquired brain lesions. His many publications provided a substantial theoretical basis for neuropsychology that continues to exert a strong influence at present.
Amplifying Privacy in Privacy Amplification

We study the classical problem of privacy amplification, where two parties Alice and Bob share a weak secret X of min-entropy k, and wish to agree on secret key R of length m over a public communication channel completely controlled by a computationally unbounded attacker Eve.
Mass of the Higgs Boson in the Canonical Realization of the Salam-Weinberg Theory

It is shown that, for a wide range of top-quark masses, the Higgs mass in the canonical realization of the Salam-Weinberg theory must be ≥ 125 GeV. The considerations are predicated on the premise that the pure τϕ 4 125 theory is a free-field theory. The bound emerges as a necessary condition, albeit within a specific scenario, to avoid the trap of a trivial Higgs sector. PACS numbers: 14.80.Gt, 12.10.Ck
Tandem Vicinal Difunctionalization: β‐Addition to α,β‐Unsaturated Carbonyl Substrates Followed by α‐Functionalization

Vicinal difunctionalization reactions play an important role in modern synthetic organic chemistry. They provide access to complex structures in a stereocontrolled fashion and act as powerful, attractive, convergent elements in synthetic strategy. Consequently, examples of these reactions are numerous. Among them may be cited the Diels–Alder reaction, which results in vicinal dialkylation of a dienophile; epoxidation–functionalization of alkenes which results in 2-substituted alkanols carbenoid additions to alkenes resulting in cyclopropanes; organometalation–functionalization of alkynes giving vicinally disubstituted alkenes, and the additions of halides and acyl halides to alkenes using Friedel–Crafts catalysts. [2 + 2] Photocycloadditions and 1,3-dipolar cycloadditions are but two of many more examples. New reactions are introduced regularly, such as radical cyclization–trapping, which recently has been applied to a synthesis of prostaglandin F2α. Keywords: tandem vicinal difunctionalization; β-addition; α,β-unsaturated carbonyl substrates; mechanisms; scope; limitations; copper reagents; stabilized reagents; unstabilized reagents; functionalizing reagents; experimental procedures; unsaturated compounds; aldehydes; ketones; esters; lactones; amides; thioamides; neutral intermediates
On the electrophoresis of cattle rhodopsin.

1. From the electrophoretic observation of cattle rhodopsin, the isoelectric point was determined as being 5.31. This value is very close to its isoionic point.2. It was ascertained that the main moving boundary was of rhodopsin origin. In some cases, two small fast moving boundaries besides the main boundary were revealed on the electrophoretic pattern. The appearance of these small boundaries would be caused by contaminated impurities.3. The mobilities of cattle rhodopsin were calculated and compared with those of ovalbumin within certain limit of PH. Despite the fact that cattle rhodopsin displays a number of titrable groups comparable with ovalbumin, its electrophoretic mobility is considerably lower than that of ovalbumin. In order to explain this discrepancy, the role of digitonin was discussed in terms of modifying the charged state of intact rhodopsin molecule.4. The electrophoretic pattern of a mixture of cattle rhodopsin and its bleached product is of asymmetrical nature. This asymmetry is presumably derived from the combination of at least two components, that is, a small amount of fast moving component and a large amount of slow moving component, which would correspond respectively to bleached product and rhodopsin. The bleached product would be slightly abundant with the net negative charges than rhodopsin.
Carbomethoxydifluoromethylation of enol acetates with methyl (chlorosulfonyl)difluoroacetate using visible-light photoredox catalysis. Synthesis of 2,2-difluoro-γ-ketoesters

Abstract In a visible light, room temperature photoredox catalytic process using 0.5 mol% of a Ir[(dF(CF 3 )ppy) 2 (dtbbpy)]PF 6 catalyst, a general method for attaching a carbomethoxydifluoromethyl group to the alpha position of a ketone, using the reaction of methyl (chlorosulfonyl)difluoroacetate (MCDA) with enol acetates, is reported. This method allows the synthesis of a variety of 2,2-difluoro-γ-ketoesters in moderate to very good yields.
Using stable isotopes to determine mineral bioavailability of functional foods

Abstract: Mineral stable isotopes allow for the direct assessment of mineral absorption in all population groups. The most widely used in human nutrition are calcium, magnesium, zinc and iron. These can be used to demonstrate the effects of interventions, including the use of functional foods, on mineral absorption both from an individual meal and from whole diets. Methodologies are safe, practical and well tolerated, even by small children.
A Compact Storage Scheme for Fast Wavelet-Based Subregion Retrieval

In an image browsing environment there is need for progressively viewing image subregions at various resolutions. We describe a storage scheme that accomplishes good image compression, while supporting fast image subregion retrieval. We evaluate analytically and experimentally the compression performance of our algorithm. We also provide results on the speed of the algorithm to demonstrate its effectiveness, and present an extension to a client/server environment.
Exploring the Racial Gap in Infant Mortality Rates, 1920-1970

White and nonwhite infant mortality rates declined sharply between 1920 and 1970, but the ratio of nonwhite/white rates did not decline. This paper examines the racial gap using state- level panel data with information on income, urbanization, women's education, and physicians per capita. We find that these variables can explain a large portion of the persistent racial gap in infant mortality rates between 1920 and 1945, but a smaller portion thereafter. We also find that even after controlling for these characteristics, southern states had relatively high infant mortality rates during this period, especially for nonwhites.
Hydrogen bonding. Part 33. NMR study of the hydration of choline and acetylcholine halides

Abstract The hydration of choline and acetylcholine halides has been studied through observation of the development of 14 N to β-CH 2 coupling as H 2 O is added in increments to the lowest liquid hydrates of these salts. Choline cation forms an initial strong, anion-independent association with ca. 4.5 H 2 O. Further addition of H 2 O leads to a larger, looser hydration shell with choline chloride; this effect is not seen with the bromide or iodide. Hydrogen bonding between cation hydroxyl group and Cl − is observed up to about 5 H 2 O for choline chloride; this type of interaction is weak or absent in solutions of the Br − and I − salts. Acetylcholine cation forms an initial strong, anion- independent association with ca. 7 H 2 O; both Cl − and Br − show subsequent formation of a looser hydration shell up to ca. 10–13 H 2 O. This is in accord with a previous phase diagram study that indicated formation of a low temperature crystalline hydrate of acetylcholine chloride with similar H 2 O content. Both choline and acetylcholine cations retain the preferred gauche conformations from the lowest liquid hydrate to dilute solutions.
Analysis of a Hypothetical Criticality Accident in a Waste Supercompactor

A hypothetical nuclear criticality accident in a waste supercompactor is examined. The material being compressed in the compactor is a homogeneous mixture of beryllium and {sup 239}Pu. The point-kinetics equations with simple thermal-hydraulic feedback are used to model the transient behavior of the system. A computer code has been developed to solve the model equations. The computer code calculates the fission power history, fission yield, bulk temperature of the system, and several other thermal-hydraulic parameters of interest. Calculations have been performed for the waste supercompactor for various material misloading configurations. The peak power for the various accident scenarios varies from 1.04 {times} 10{sup 17} to 4.85 {times} 10{sup 20} fissions per second (fps). The total yield varies from 8.21 {times} 10{sup 17} to 7.73 {times} 10{sup 18} fissions, and the bulk temperature of the system varies from 412 to >912 K.
Modeling transportation routines using Hybrid Dynamic Mixed Networks

This paper describes a general framework called Hybrid Dynamic Mixed Networks (HDMNs) which are Hybrid Dynamic Bayesian Networks that allow representation of discrete deterministic information in the form of constraints. We propose approximate inference algorithms that integrate and adjust well known algorithmic principles such as Generalized Belief Propagation, Rao-Blackwellised Particle Filtering and Constraint Propagation to address the complexity of modeling and reasoning in HDMNs. We use this framework to model a person's travel activity over time and to predict destination and routes given the current location. We present a preliminary empirical evaluation demonstrating the effectiveness of our modeling framework and algorithms using several variants of the activity model.
Automatic Extraction of Object-Oriented Observer Abstractions from Unit-Test Executions

Unit testing has become a common step in software development. Although manually created unit tests are valuable, they are often insufficient; therefore, programmers can use an automatic unit-test-generation tool to produce a large number of additional tests for a class. However, without a priori specifications, programmers cannot practically inspect the execution of each automatically generated test. In this paper, we develop the observer abstraction approach for automatically extracting object-state-transition information of a class from unit-test executions, without requiring a priori specifications. Given a class and a set of its initial tests generated by a third-party tool, we generate new tests to augment the initial tests and produce the abstract state of an object based on the return values of a set of observers (public methods with non-void returns) invoked on the object. From the executions of both the new and initial tests, we automatically extract observer abstractions, each of which is an object state machine (OSM): a state in the OSM represents an abstract state and a transition in the OSM represents method calls. We have implemented the Obstra tool for the approach and have applied the approach on complex data structures; our experiences suggest that this approach provides useful object-state-transition information for programmers to inspect unit-test executions effectively.
Anaphase motions in dilute colchicine: Evidence of two phases in chromosome segregation

Abstract We have examined the rates of chromosome and pole motion during anaphase in HeLa cells using differential interference contrast and polarization optics. In early anaphase both chromosomes and poles move apart. When the chromosomes are separated by a distance about equal to the metaphase spindle length, both chromosomes and poles slow but continue to move at a reduced rate. Throughout anaphase, the chromosomes move faster than the poles, so the chromosome-to-pole distance decreases. Treatment of the cells with about 5 × 10−8 M colchicine up to 45 min before observation tends to block normal formation of metaphase spindles, but more than half of the cells in metaphase go on through anaphase. In these cells, both chromosome and pole motions are essentially normal until the chromosomes are separated by a distance equal to the length of the metaphase spindle. After that time, chromosome motion is supressed and the poles move slowly toward one another. These data suggest that the mechanism of anaphase motion changes character when the chromosomes become spaced by the metaphase spindle length. We call anaphase before and after that time phase 1 and phase 2, respectively. The results are discussed in the light of a sliding tubule model for chromosome motion.
Advice coins for classical and quantum computation

We study the power of classical and quantum algorithms equipped with nonuniform advice, in the form of a coin whose bias encodes useful information. This question takes on particular importance in the quantum case, due to a surprising result that we prove: a quantum finite automaton with just two states can be sensitive to arbitrarily small changes in a coin's bias. This contrasts with classical probabilistic finite automata, whose sensitivity to changes in a coin's bias is bounded by a classic 1970 result of Hellman and Cover. Despite this finding, we are able to bound the power of advice coins for space-bounded classical and quantum computation. We define the classes BPPSPACE/coin and BQPSPACE/coin, of languages decidable by classical and quantum polynomial-space machines with advice coins. Our main theorem is that both classes coincide with PSPACE/poly. Proving this result turns out to require substantial machinery. We use an algorithm due to Neff for finding roots of polynomials in NC; a result from algebraic geometry that lower-bounds the separation of a polynomial's roots; and a result on fixed-points of superoperators due to Aaronson and Watrous, originally proved in the context of quantum computing with closed timelike curves.
Integrated STEM in Elementary Grades Using Distributed Agent-based Computation

We investigate how the integration of visual agent-based programming and computationally augmented physical structures can support curricular integration across STEM domains for elementary grade students. We introduce ViMAP-Tangible, a socio-technically distributed computational learning environment, which integrates ultrasonic sensors with the ViMAP visual programming language using a distributed computation infrastructure. In this paper, we report a study in which 3rd and 4th grade students used ViMAP-Tangible to engage in collaborative design-based activities in order to invent "drawing machines'' for generating geometric shapes. The curricular activities integrate engineering practices such as user-centered design, mathematical reasoning about multiplication, rates and fractions, and physical science concepts central to learning Newtonian mechanics. We identify the key affordances of the learning environment and our pedagogical approach in terms of the relationship between the structural elements of studentsâ physical constructions and computational models, and their learning outcomes, both in terms of computational thinking, and the domain-specific, mathematical and scientific knowledge that they began developing.
Advances in Quantitative Analysis of Finance and Accounting

Aims to disseminate developments in the quantitative analysis of finance and accounting. This work is a forum for statistical and quantitative analyses of issues in finance and accounting as well as applications of quantitative methods to problems in financial management, financial accounting, and business management.
Does SIZE Matter? Liquidity Provision by the Nasdaq Anonymous Trading Facility

I examine the effects of Nasdaq's introduction of an anonymous trading facility called SIZE. I compare SIZE to competing ECNs in terms of liquidity and market impact. Despite rapid growth, SIZE has not yet attained a significant market share and rarely influences short-run price evolution. I conclude with discussion of the Nasdaq-ECN mergers and speculate about a role for SIZE in trading listed securities.
Visual analytics: a grand challenge in science: turning information overload into the opportunity of the decade

Visual Analytics is an emerging field of study that brings talents from many disciplines including statistics, mathematics, knowledge representation and synthesis, scientific and information visualization, cognitive and perceptual sciences, communications, decision sciences and more. The demand for visual analytics is being stimulated by new requirements for homeland security but similar needs are present in science, commerce, home, and almost any domain that deals with complex, large information sources that require human judgment to "detect the expected and discover the unexpected". The definition of visual analytics is the science of analytical reasoning facilitated by the visual interface. Jim will present the new needs for science and technology, referenced from the recent book Illuminating the Path: the Research and Development Agenda for Visual Analytics, http://nvac.pnl.gov/. Jim will also discuss the driving new characteristics of interaction and suggest the top technical challenges for visual analytics, enlisting comments and recommendations.
Fundamental Mechanisms of Copper CMP – Passivation Kinetics of Copper in CMP Slurry Constituents

During copper CMP, abrasives and asperities interact with the copper at the nano-scale, partially removing protective films. The local Cu oxidation rate increases, then decays with time as the protective film reforms. In order to estimate the copper removal rate and other Cu-CMP output parameters with a mechanistic model, the passivation kinetics of Cu, i.e. the decay of the oxidation current with time after an abrasive/copper interaction, are needed. For the first time in studying Cu-CMP, microelectrodes were used to reduce interference from capacitive charging, IR drops and low diffusion limited currents, problems typical with traditional macroelectrodes. Electrochemical impedance spectroscopy (EIS) was used to obtain the equivalent circuit elements associated with different electrochemical phenomena (capacitive, kinetics, diffusion etc.) at different polarization potentials. These circuit elements were used to interpret potential-step chronoamperometry results in inhibiting and passivating solutions, notably to distinguish between capacitive charging and Faradaic currents. Chronoamperometry of Cu in acidic aqueous glycine solution containing the corrosion inhibitor benzotriazole (BTA) displayed a very consistent current decay behavior at all potentials, indicating that the rate of current decay was controlled by diffusion of BTA to the surface. In basic aqueous glycine solution, Cu (which undergoes passivation by a mechanism similar to that operating in weakly acidic hydrogen peroxide slurries) displayed similar chronoamperometric behavior for the first second or so at all anodic potentials. Thereafter, the current densities at active potentials settled to values around those expected from polarization curves, whereas the current densities at passive potentials continued to decline. Oxidized Cu species typically formed at ‘active’ potentials were found to cause significant current decay at active potentials and at passive potentials before more protective passive films form. This was established from galvanostatic experiments.
MPI on BlueGene/L: Designing an Efficient General Purpose Messaging Solution for a Large Cellular System

The BlueGene/L computer uses system-on-a-chip integration and a highly scalable 65,536-node cellular architecture to deliver 360 Tflops of peak computing power. Efficient operation of the machine requires a fast, scalable, and standards compliant MPI library. In this paper, we discuss our efforts to port the MPICH2 library to BlueGene/L.
Russian Inequality on the Eve of Revolution

Careful handling of an eclectic data set reveals how unequal were the incomes of different classes of Russians on the eve of Revolution. We estimate incomes by economic and social class in each of the fifty provinces of European Russia. On the eve of military defeat and the 1905 Revolution, Russian income inequality was middling by the standards of that era, and less severe than is inequality today in China, the United States, and Russia itself. We note how the interplay of some distinctive fiscal and relative-price features of Imperial Russia might have shaped the now-revealed level of inequality.
Metabolism studies with rats suffering from fat deficiency.

Wesson and Burr1 showed that rats reared on the fat-deficient diet of Burr and Burr2 gave respiratory quotients above unity and exceptionally high metabolic rates after a carbohydrate meal. Normal rats had lower basal rates and did not show the very high respiratory quotients or great specific dynamic action of the food.This work has been continued over a period of 2 years with selected rats and their litter mate controls. A different technique has been used in order to follow gas exchange of the rats under normal conditions over long periods of time. An open-circuit apparatus with constant air stream has been used in conjunction with an automatic sampler (to be described elsewhere) which collects the dry samples over mercury and holds them for analysis. The Haldane-Carpenter3 apparatus was used for determining the CO2 and O2.The rats have been divided into 3 groups: those reared on stock diet; those reared on fat-deficient diet; and those reared on fat-deficient diet and then cured with certain fats. Thr...
Sophisticated Intermediation and Aggregate Volatility

I consider an economy where investors delegate their investment decisions to financial institutions that choose across multiple investment opportunities featuring different levels of idiosyncratic risk and different degrees of correlation with the aggregate of the economy. Investors solve an optimal contracting problem to induce financial institutions to allocate their investment optimally. I then study how investment decisions are affected when financial securities are introduced that allow agents to trade their risks. Investors do not have the necessary information to understand these securities, but give incentives to financial institutions to hedge certain risks. I show that hedging idiosyncratic risks ameliorates the agency problem between investors and financial institutions and reduces aggregate volatility. On the contrary, when aggregate risk can be hedged the agency problem worsens and aggregate volatility increases. Finally, I study the efficiency properties of the equilibrium and the potential role for financial regulation.
Sub-Laplacians on Sub-Riemannian Manifolds

We consider different sub-Laplacians on a sub-Riemannian manifold M. Namely, we compare different natural choices for such operators, and give conditions under which they coincide. One of these operators is a sub-Laplacian we constructed previously in Gordina and Laetsch (Trans. Amer. Math. Soc., 2015). This operator is canonical with respect to the horizontal Brownian motion; we are able to define this sub-Laplacian without some a priori choice of measure. The other operator is $\operatorname {div}^{\omega } \operatorname {grad}_{\mathcal {H}}$ for some volume form ω on M. We illustrate our results by examples of three Lie groups equipped with a sub-Riemannian structure: SU(2), the Heisenberg group and the affine group.
FOKKER-PLANCK/TRANSPORT ANALYSES OF FUSION PLASMAS IN CONTEMPORARY BEAM-DRIVEN TOKAMAKS

The properties of deuterium plasmas in experimental tokamaks heated and fueled by intense neutral-beam injection are evaluated with a Fokker-Planck/radial transport code coupled with a Monte Carlo neutrals treatment. Illustrative results are presented for the Poloidal Divertor Experiment at PPPL as a function of beam power and plasma recycling coefficient, R/sub c/. When P/sub beam/ = 8 MW at E/sub b/ = 60 keV, and R/sub c/ = 0.2, then approximately 0.5, (/sup 2///sub 3/ ) = 22 keV approximately 6, and the D-D neutron intensity is 10/sup 16/ n/sec.
Bank and Nonbank Lenders and the Commercial Mortgage Market

This paper develops an equilibrium model of the commercial mortgage market that includes the sequence from commitment to origination and allows testing for differences by type of lender. From borrowers, loan demand is based on the income yield, capital gains, and expectations about return distributions. Lenders use prices such as mortgage rates and their distributions, and quantities in underwriting standards. There are separate equilibria in the markets for loan commitments and originations. Bank and nonbank lenders are not restricted to the same lending technology, nor to the weights placed on mortgage rates as opposed to underwriting standards. Empirical results for the United States commercial mortgage market indicate that banks use interest rates in allocating credit while nonbanks rely on underwriting standards, notably the loan-to-value ratio. A consequence is that nonbanks have a clientele incentive towards making low cap rate loans compensated by low loan-to-value ratios.
Correctness of the Concurrent Approach to Symbolic Verification of Interleaved Models

Interleaved models of computations limit the number of system components that can change states simultaneously. This restriction often decreases efficiency of symbolic verification methods based on binary decision diagrams. We propose to ignore this restriction, and allow all components to change states simultaneously. This approach may result in an over-approximation of reachable states. We show that if a system satisfies certain conditions, then the approach computes reachable states exactly. We also show that even if a system does not meet these conditions, it is still possible to compute its reachable states exactly by only partially removing interleaving restrictions. We present experiments that show that the approach improves efficiency of symbolic verification, even when costs of correctness testing are taken into account.
Optimal Expected Discounted Reward of a Wireless Network with Award and Cost

In this paper, we extend our previous optimization investigation on a single cell (IEEE Transactions on Wireless Communications, vol. 8, no. 2, pp. 1038-1044, 2009) to a whole network with multiple cells and further consider the call admission control (CAC) based on the total expected discounted reward. Here, the system will get the award for admitting a call, but will incur a cost for rejecting a call and incur a cost for holding a call. Call’s routing between cells in the network is characterized probabilistically. Under several realistic assumptions on network in general, we consider the reserved channel scheme in the literature and applied the theory of continuous time Markov decision process to derive the optimal policy. We figure out the optimal CAC policy of when to admit or reject an arrival call (either new call or handoff call) in order to achieve the maximum total expected discounted reward for the scheme. Our numerical analysis confirms the correctness of our result for this whole network investigation. The result of this paper could be applied in designing wireless networks for optimal performance, and be extended to the multiple classes of calls in the deign of future wireless mobile multimedia networking.
An ultra-wideband absorber backed planar slot antenna

Planar antenna designs have many advantages such as low-profile, light-weight, and ease of fabrication and integration. Low-cost is often desired but this depends on the chosen substrate. The substrate can also dominate the ruggedness of the antenna, such as the use of ceramics which can be brittle. Here, a planar slot antenna implemented on ceramic substrate with coplanar waveguide feed is considered. With absorber loading the design provides 50 Ω input impedance over the frequency range 0.3–3 GHz so it is considered ultra-wideband. This paper summarizes a numerical investigation using both frequency and time-domain solvers. The results serve to guide the future analysis of broadband antennas with lossy dielectric loading for ground penetrating radars. The evaluation of radar performance requires further simulation and model validation based on antenna measurements.
Mass Spectra from Turbulent Fragmentation

Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass from the surrounding cloud material. This process is investigated, using numerical models of molecular cloud dynamics. Molecular cloud regions without turbulent driving sources, or where turbulence is driven on large scales, exhibit rapid and efficient star formation in a clustered mode, whereas interstellar turbulence that carries most energy on small scales results in isolated star formation with low efficiency. The clump mass spectrum of shock-generated density fluctuations in pure hydrodynamic, supersonic turbulence is not well fit by a power law, and it is too steep at the high-mass end to be in agreement with the observational data. When gravity is included in the turbulence models, local collapse occurs, and the spectrum extends towards larger masses as clumps merge together, a power-law description dN/dM ∝ M ν becomes possible with slope ν ≲ − 2. In the case of pure gravitational contraction, i.e. in regions without turbulent support, the clump mass spectrum is shallower with ν ≈ − 3/2. The mass spectrum of protostellar cores in regions without turbulent support and where turbulence is replenished on large-scales, however, is well described by a log-normal or by multiple power laws, similar to the stellar IMF at low and intermediate masses. In the case of small-scale turbulence, the core mass spectrum is too flat compared to the IMF for all masses.
Reshaping of freely propagating terahertz pulses by diffraction

We discuss the application of diffraction theory to the reshaping of freely propagating terahertz pulses by narrow apertures. This is accomplished by using two separate electrooptic sampling detectors. The first contains a narrow electrode geometry that does not modify the frequency content of the incident terahertz field, while the second contains a narrow gap between two large electrodes. The latter detector transforms the incident bipolar terahertz waveform into a unipolar waveform. We find that diffraction theory properly accounts for this reshaping process. We discuss the applicability of alternate electrode geometries for terahertz pulse shaping.
A Summary and Update of Developing Annuities Markets : The Experience of Chile

The rapid growth of the market for retirement products in Chile has its origins in the pension reform that was implemented in 1981. But the successful development of an active annuity market also reflects many other factors. This paper summarizes and updates an earlier longer study on the development of the Chilean annuity market. The update focuses on the numerous changes that were introduced in 2008. The most striking aspect of the Chilean experience is the very high rate of annuitization. This has been linked to the restrictions that have been applied to lump-sum withdrawals, the offer of inflation-protected annuities, and the robust prudential regulation of providers. But the level of annuitization has also been supported by the annuitization incentives provided to early retirees and the influence of brokers and sales agents. The recent regulatory changes have weakened the impact of the last two factors, while strengthening the demand for annuities at normal retirement.
Did the Community Renewal Tax Incentives Pirate Businesses from Other Places

An early concern regarding place-based economic developments was that they might encourage business relocation into target neighborhoods at the expense of other places. To address this concern, when the U.S. Congress passed the Empowerment Zone/Enterprise Community (EZ/EC) program, it included an “antipirating” provision prohibiting use of grants for business relocation. Later iterations of the EZs and Renewal Communities (RCs) received tax incentives only. The RC program did not include an antipirating provision. Did businesses relocate? This study compares business moves within 1,000 feet inside a given RC/EZ with moves within 1,000 feet outside the RC/EZ before and after the intervention. Data are from the National Establishment Time Series (NETS) Database for California and Tennessee. Moves into some RC/EZs increased but so did moves out, leading to no statistically significant net change in numbers of firms. There were no obvious differences between RCs and EZs. The article concludes with policy recommendations.
Temperature Gradients Through EHD Films and Molecular Alignment Evidenced By Infrared Spectroscopy

Partial and complete emission band reversals have been observed in the infrared emission spectra from portions of operating sliding contacts. An elementary analysis has been carried out to show that partial reversals are due to temperature gradients in the fluid film - the film acts both as a radiation-emitter and absorber, and that total reversals - an emission spectrum appears as an absorption spectrum are likely to be due to a continuum source, such as hot solid asperities. The total energy radiated under the latter conditions exceeds that under the others. A decrease in gap width with increased load was accompanied by a dramatic spectral change in the case of 5P4E polyphenyl ether, which is indicative of molecular alignment.
Chordal and sequentially Cohen-Macaulay clutters

We extend the definition of chordal from graphs to clutters. The resulting family generalizes both chordal graphs and matroids, and obeys many of the same algebraic and geometric properties. Specifically, the independence complex of a chordal clutter is shellable, hence sequentially Cohen-Macaulay; and the circuit ideal of a certain complement to such a clutter has a linear resolution. Minimal non-chordal clutters are also closely related to obstructions to shellability, and we give some general families of such obstructions, together with a classification by computation of all obstructions to shellability on 6 vertices.
FED-R: A Fusion Engineering Device Utilizing Resistive Magnets

The principal purpose of the FED-R tokamak facility is to provide a substantial quasisteady flux of fusion neutrons irradiating a large test area in order to carry out thermal, neutronic, and radiation effects testing of experimental blanket assemblies. The emphasis on reliable nuclear testing capability demands that the plasma physics characteristics and technological features of the fusion machine be chosen as close to mid-1980s state of the art as possible, with the important exception that FED-R requires high-duty-factor operation. The outboard nuclear test region is at least 80-cm deep with approximately 60 m/sup 2/ of exposure area. The neutron wall loading is 0.4 MW/m/sup 2/ in Stage I operation (Q/sub p/ = 1.5) and 1.3 MW/m/sup 2/ in Stage II (Q/sub p/ = 2.5). The toroidal field coils are fabricated of water-cooled copper plates with demountable joints and operate steady state with a power dissipation of 180 MW in Stage I and 280 MW in Stage II.
Embedding a Forest in a Graph

For $p\ge 1$, we prove that every forest with $p$ trees whose sizes are $a_1, \ldots, a_p$ can be embedded in any graph containing at least $\sum_{i=1}^p (a_i + 1)$ vertices and having minimum degree at least $\sum_{i=1}^p a_i$.