cssi/SciSciGPT-SciSciNet huggingface dataset:
Current-induced magnetization switching in small domains of different anisotropies

Several recent experimental studies have confirmed the possibility of switching the magnetization direction in small magnetic domains by pumping large spin-polarized currents through them. On the basis of equations proposed by Slonczewski for domains with uniform magnetization, we analyze the stability and switching in two cases which differ by the anisotropy type. One of anisotropy types corresponds to that of the existing experimental device. Qualitatively different behavior is found in shapes of bistable regions and regions with stable precession. Stabilization of unusual 'canted' equilibria is found in one of the cases. The sensitivity of the switching pattern to a change in anisotropy pattern underscores the necessity of theoretical guidance for the interpretation of experimental results. We propose experiments to search for stabilized canted equilibria and precession cycles. Our study is analytic as opposed to recent numeric work and the method can be applied to other anisotropy patterns as the experimental interest develops.
High frequency scattering from corrugated stratified cylinders

Interest in applying radar remote sensing for the study of forested areas led to the development of a model for scattering from corrugated stratified dielectric cylinders. The model is used to investigate the effect of bark and its roughness on scattering from tree trunks and branches. The outer layer of the cylinder (bark) is assumed to be a low-loss dielectric material and to have a regular (periodic) corrugation pattern. The inner layers are treated as lossy dielectrics with smooth boundaries. A hybrid solution based on the moment method and the physical optics approximation is obtained. New expressions for the equivalent physical-optics currents are used which are more convenient than the standard ones. It is shown that the bark layer and its roughness both reduce the radar cross-section. It is also demonstrated that the corrugations can be replaced by an equivalent anisotropic layer. >
Diastereoselective (Ethoxycarbonyl)difluoromethylation of Chiral Imide Enolates Mediated by Triethylborane

Triethylborane-mediated reactions of lithium enolates derived from chiral N-acyloxazolidinones with ethyl difluoroiodoacetate allows easy access to α-(ethoxycarbonyl)difluoromethylated carboximides with good diastereomeric excess (86->98%de). The stereochemistry of the (ethyoxycarbonyl)difluoromethylated carboximides indicates that the (ethoxycarbonyl)difluoromethyl radical generated from ethyl difluoroiodoacetate and triethylborane reacts preferentially on the si face of the lithium enolates.
On Choosing a Task Assignment Policy for a Distributed Server System

We consider a distributed server system in which each host processes tasks in First-Come-First-Served order and each task's service demand is known immediately upon task arrival. We consider four task assignment policies commonly proposed for such distributed server systems: Round Robin; Random; Size-Based, in which all tasks within a given size range are assigned to a particular host; and Dynamic-Least-Work-Remaining, in which a task is assigned to the host with the least outstanding work. Using analysis and simulation, we explore the influence of task size variability on which task assignment policy is best. Surprisingly, we find that not one of the above task assignment policies is best. In particular, we find that when the task sizes are not highly variable, the Dynamic policy is preferable. However, when task sizes show the degree of variability more characteristic of empirically measured workloads, the size-based policy is the best choice. We use the resulting observations to argue in favor of a specific size-based policy, SITA-E, that shows very good performance for realistic task size distributions.
THE NAKED EMERGENCE OF SOLAR ACTIVE REGIONS OBSERVED WITH SDO/HMI

We take advantage of the HMI/SDO instrument to study the naked emergence of active regions (ARs) from the first imprints of the magnetic field on the solar surface. To this end, we followed the first 24 hr in the life of two rather isolated ARs that appeared on the surface when they were about to cross the central meridian. We analyze the correlations between Doppler velocities and the orientation of the vector magnetic field, consistent finding that the horizontal fields connecting the main polarities are dragged to the surface by relatively strong upflows and are associated with elongated granulation that is, on average, brighter than its surroundings. The main magnetic footpoints, on the other hand, are dominated by vertical fields and downflowing plasma. The appearance of moving dipolar features (MDFs, of opposite polarity to that of the AR) in between the main footpoints is a rather common occurrence once the AR reaches a certain size. The buoyancy of the fields is insufficient to lift up the magnetic arcade as a whole. Instead, weighted by the plasma that it carries, the field is pinned down to the photosphere at several places in between the main footpoints, giving life to the MDFsmore » and enabling channels of downflowing plasma. MDF poles tend to drift toward each other, merge and disappear. This is likely to be the signature of a reconnection process in the dipped field lines, which relieves some of the weight allowing the magnetic arcade to finally rise beyond the detection layer of the Helioseismic and Magnetic Imager spectral line.« less
Current short-range tests of the gravitational inverse square law

Abstract Motivated in large part by the possibility of observing signatures of compact extra dimensions, experimental searches for deviations from Newtonian gravity at short distances have improved in sensitivity by many orders of magnitude in the past five years. We review the essential features of the experiments responsible for the current limits on new effects in the range from a few microns to a few centimeters, and discuss prospects for the near future. To cite this article: J.C. Long, J.C. Price, C. R. Physique 4 (2003).
A miniature XRD/XRF instrument for in-situ characterization of Martian soils and rocks

In the context of the exploration of Mars, the availability of an instrument for in-situ mineralogical characterization of the surface of the planet is of the highest importance. We are developing a miniature X-ray diffraction / fluorescence instrument for this specific purpose. The concept of the instrument is based on the use of a single CCD detector exposed directly to the X-rays diffracted and fluoresced by a sample. A fust prototype has been realized to test the concept of simultaneous XRD and XRF measurement with a single CCD detector. This paper presents the result obtained after refinement of this instrument. The capability of the technique has been proven. Further developments are planned to propose a miniature XRD/XRF instrument for planetary exploration. The concept utilized in this project could find a range of applications as laboratory instruments or portable instruments.
The groupon effect on yelp ratings: a root cause analysis

Daily deals sites such as Groupon offer deeply discounted goods and services to tens of millions of customers through geographically targeted daily e-mail marketing campaigns. In our prior work we observed that a negative side effect for merchants selling Groupons is that, on average, their Yelp ratings decline significantly. However, this previous work was primarily observational, rather than explanatory. In this work, we rigorously consider and evaluate various hypotheses about underlying consumer and merchant behavior in order to understand this phenomenon, which we dub the Groupon effect. We use statistical analysis and mathematical modeling, leveraging a dataset we collected spanning tens of thousands of daily deals and over 7 million Yelp reviews. We investigate hypotheses such as whether Groupon subscribers are more critical than their peers, whether Groupon users are experimenting with services and merchants outside their usual sphere, or whether some fraction of Groupon merchants provide significantly worse service to customers using Groupons. We suggest an additional novel hypothesis: reviews from Groupon users are lower on average because such reviews correspond to real, unbiased customers, while the body of reviews on Yelp contain some fraction of reviews from biased or even potentially fake sources. Although our focus is quite specific, our work provides broader insights into both consumer and merchant behavior within the daily deals marketplace.
Chemoselectivity in the isonitrile metathesis route to aromatic amines

Abstract Chemoselectivity and structural effects in thermal benzannulation reactions employing chromium carbene complexes and isonitriles are reported. Alkyl, aryl, sterically hindered, electron deficient, and electron rich isonitriles all react efficiently with several chromium carbene complexes to provide aromatic amine products.
The new biology of sleep

Publisher Summary This chapter discusses the biology of sleep. Animal experiments with depth recording have revealed that the cortical desynchrony of rapid eye movement (REM) sleep is associated with characteristic electrical patterns in other parts of the brain. It is found that with a transection through the rostral border of the midbrain, caudal indicators of slow-wave (SW) sleep disappeared but REM sleep identified by eye movements and atonia was preserved. Furthermore, more caudally placed transections failed to eliminate the observable symptoms of REM sleep until the brain stem was transected at the lower border of the pons. The localization of a REM trigger in the pons was confirmed by a series of coagulation studies in which complete destruction of the nucleus reticularis pontis caudalis eliminated REM sleep. The otherwise intact cat continued to have SW sleep with normal periodicity. It is not yet certain whether it is possible to trigger the REM state by the stimulation of the pontine center. It is reported that they could induce REM sleep by stimulating this or nearby areas.
For a Sociology of Flesh and Blood

This article elaborates the social ontology and methodology of carnal sociology as a distinctive mode of social inquiry eschewing the spectatorial posture to grasp action-in-the-making, in the wake of debates triggered by my apprenticeship-based study of boxing as a plebeian bodily craft. First I critique the notions of (dualist) agent, (externalist) structure, and (mentalist) knowledge prevalent in the contemporary social sciences and sketch an alternative conception of the social animal, not just as wielder of symbols, but as sensate, suffering, skilled, sedimented, and situated creature of flesh and blood. I spotlight the primacy of embodied practical knowledge arising out of and continuously enmeshed in webs of action and consider what modes of inquiry are suited to deploying and mining this incarnate conception of the agent. I argue that enactive ethnography, the brand of immersive fieldwork based on “performing the phenomenon,” is a fruitful path toward capturing the cognitive, conative, and cathectic schemata (habitus) that generate the practices and underlie the cosmos under investigation. But it takes social spunk and persistence to reap the rewards of “observant participation” and achieve social competency (as distinct from empirical saturation). In closing, I return to Bourdieu’s dialogue with Pascal to consider the special difficulty and urgency of capturing the “spirit of acuteness” that animates such competency but vanishes from normal sociological accounts.
Random walks on free solvable groups

For any finitely generated group $$G$$ , let $$n\mapsto \Phi _G(n)$$ be the function that describes the rough asymptotic behavior of the probability of return to the identity element at time $$2n$$ of a symmetric simple random walk on $$G$$ (this is an invariant of quasi-isometry). We determine this function when $$G$$ is the free solvable group $$\mathbf {S}_{d,r}$$ of derived length $$d$$ on $$r$$ generators and some related groups.
A novel ring system arising from intramolecular oxidative cyclization of 8-(4-pentenyl)dihydroberberine

Abstract An unusual oxidative cyclization reaction was observed in the course of studies on the synthesis of berberine linked to oligonucleotides at the 8-position. The novel ring structure of the oxidative cyclization product was confirmed using X-ray crystallography.
Integument permeability of crabs and adaptation to land

Abstract 1. 1. Most of the evaporative water loss of land and aquatic crabs occurs through the shell. Applications of petroleum jelly to the integument usually reduced evaporation over 50 per cent. Losses from dead crabs were virtually the same as living crabs. 2. 2. The permeability of pieces of shell from eight species were correlated with the crab's habitats; terrestrial forms were least permeable while aquatic species were most permeable to water.
Information technology standards for libraries

The general view is that standards tend to reduce chaos, enhance the credibility of compliant organizations, and often foster creativity at the individual level. On one hand, it has been argued that there are too many standards-making bodies and too many standards, and that the proliferation of standards often does no more than serve the interests of specific industries and markets. On the other hand, the proponents of standards and the standards-making process contend that while standards intended for different uses or different constituencies tend to cause conflict at the edges, the same standards reflect the varied and often deep needs of the domains to which the standards are applied, and that the standards process, in its emphasis on procedure, creates a desirable orderliness that engenders beneficial efficiencies and makes interoperability possible. Information technology standards, which have been an important part of librarianship in the United States for more than 75 years, are more important than ever. In the digital era, the environment in which such standards arise grows increasingly complex, as the technical concerns of librarians and archivists intersect with the communities formulating technical standards for computing, networking, and digital publishing in general. In this essay, which assumes that the benefits of technical standards far outweigh any liabilities in the library marketplace, the nature of standards and basic aspects of the standardization process are described, key standards-making organizations are identified and their roles are assayed, and the various benefits of information-oriented technical standards are assessed.
Lorentzian twistor spinors and CR-geometry

Abstract We prove that there exist global solutions of the twistor equation on the Fefferman spaces of strictly pseudoconvex spin manifolds of arbitrary dimension and we study their properties.
The Economic Performance of Immigrants: a Theory of Assortative Matching

The economic performance of U.S. immigrants differs substantially from that of natives in ways that pose difficulties for standard theories of migration. In particular, immigrants cluster geographically and are often employed together. Immigrant earnings differ by origin and time spent in the United States, even after controlling for education and experience. A large fraction of immigrants eventually returns home, even to low-wage countries. This article offers a theory of international migration based on assortative matching under imperfect information that accounts for a broad range of these empirical regularities.
Indole alkaloids in plant hallucinogens.

(1976). Indole Alkaloids In Plant Hallucinogens. Journal of Psychedelic Drugs: Vol. 8, No. 1, pp. 7-25.
Existence and non-uniqueness of similarity solutions of a boundary layer problem

A Blasius boundary value problem with inhomogeneous lower boundary conditions f(0) = 0 and f'(0) = - lambda with lambda strictly positive was considered. The Crocco variable formulation of this problem has a key term which changes sign in the interval of interest. It is shown that solutions of the boundary value problem do not exist for values of lambda larger than a positive critical value lambda. The existence of solutions is proven for 0 lambda lambda by considering an equivalent initial value problem. It is found however that for 0 lambda lambda, solutions of the boundary value problem are nonunique. Physically, this nonuniqueness is related to multiple values of the skin friction.
Imperfect construction of microclusters

Microclusters are the basic building blocks used to construct cluster states capable of supporting fault-tolerant quantum computation. In this paper, we explore the consequences of errors on microcluster construction using two error models. To quantify the effect of the errors we calculate the fidelity of the constructed microclusters and the fidelity with which two such microclusters can be fused together. Such simulations are vital for gauging the capability of an experimental system to achieve fault tolerance.
Two imaging spectrometer designs using aberration-corrected holographic recording solutions

Two design concepts for imaging spectrometers are presented. These designs employ first generation, type II holographic gratings to control aberrations and provide excellent spatial resolution with sufficient spectral resolution to isolate individual emission lines over a finite field of view. This effectively creates a narrow band imaging capability. The first designs utilizes a planar substrate with aberration corrected, holographic rulings that is placed in the converging beam of an imaging system. This work demonstrates how the system performance can be substantially increased beyond the performance of an analytic solution using raytrace based computer optimization, which treats all the aberrations simultaneously. The final recording solution and system performance are strongly influenced by the choice of merit functions used in the optimization. The second class of design solutions is based on the classical cassegrain telescope. In these designs aberration corrected, holographic rulings are applied to the parabolic primary or the hyperbolic secondary of the cassegrain telescope. The holographic recording solution for either optic is designed to minimize the aberrations at a specific wavelength. The goal of this work is to explore how the off-axis aberrations of the telescope can be controlled by the holographic rulings at a single wavelength, thus creating an instrument with the high spatial resolution of a cassegrain telescope and the wavelength specific response imposed by the holographic grating.
New relations between spinor and scalar one-loop effective Lagrangians in constant background fields

Simple new relations are presented between the one-loop effective Lagrangians of spinor and scalar particles in constant curvature background fields, both electromagnetic and gravitational. These relations go beyond the well-known cases for self-dual background fields.
Synthesis of Macrocyclic Insect-Derived Alkaloids

Macrocyclic lactonic alkaloids found in the pupal secretions of two species of a coccinellid beetle (genus Epilachna) were prepared in enantiomerically pure form via an efficient synthetic route using enantiomerically pure α-amino acids as chiral-pool starting materials. Macrocycles with rings containing up to 98 atoms were synthesized in good yield using Mukaiyama's macrolactonization conditions.
Capitalism, socialism and the physical quality of life.

(1989). Capitalism, socialism and the physical quality of life. Medical Anthropology: Vol. 11, Socialist Health/Capitalist Health: Is There a Difference?, pp. 151-166.
Discounting time and time discounting: Subjective time perception and intertemporal preferences.

Abstract Consumers often make decisions about outcomes and events that occur over time. This research examines consumers' sensitivity to the prospective duration relevant to their decisions and the implications of such sensitivity for intertemporal trade-offs, especially the degree of present bias (i.e., hyperbolic discounting). The authors show that participants' subjective perceptions of prospective duration are not sufficiently sensitive to changes in objective duration and are nonlinear and concave in objective time, consistent with psychophysical principles. More important, this lack of sensitivity can explain hyperbolic discounting. The results replicate standard hyperbolic discounting effects with respect to objective time but show a relatively constant rate of discounting with respect to subjective time perceptions. The results are replicated between subjects (Experiment 1) and within subjects (Experiments 2), with multiple time horizons and multiple descriptors, and with different measurement ord...
Combination pharmacologic therapies for heart failure: what next after angiotensin-converting enzyme inhibitors and beta-blockers?

Although the introduction of angiotensin-converting enzyme (ACE) inhibitors and β-adrenergic blockers has resulted in significant improvements in the management of heart failure (HF), morbidity and mortality remain high. Therefore, additional approaches have been sought to discover newer agents that might add incremental benefit. Although not all of these approaches have been successful, there have been some notable new approaches to therapy that have shown benefit or may be promising in terms of additional benefit. Most of these agents are targeted to achieve a more global neurohormonal blockade aiming to reduce or potentially reverse the ventricular remodeling process that occurs in HF. Some of the newer approaches aim for targets other than neurohormonal systems, eg, effects on myocardial metabolism or the vasculature. This article reviews the latest advances in pharmacologic therapy in HF, looking at several trials that may have a significant impact on the treatment of HF. We also discuss several newer agents with promising potential in HF management.
Thermodynamic Molecular Switch in Sequence-Specific Hydrophobic Interactions.

minimum in the Gibbs free energy change of reaction, and hence, a maximum in the related . This presentation demonstrates the existence of a thermodynamic molecular switch in the pairwise, sequence-specific hydrophobic interaction of Ile-Ile, Leu-Ile, Val-Leu, or Ala-Leu over the temperature range of 273–333 K, as reported by Nemethy and Scheraga[1] and analyzed by the Plank-Benzinger methodology[2–7].
Knot adjacency and satellites

A knot K is called n-adjacent to the unknot, if K admits a projection containing n generalized crossings such that changing any 0 0, if and only if it is n-adjacent to the unknot in any companion solid torus. In particular, every model knot of K is n-adjacent to the unknot. Along the way of proving these results, we also show that 2-bridge knots of the form Kp/q, where p/q=[2q1,2q2] for some q1,q2∈Z, are precisely those knots that have genus one and are 2-adjacent to the unknot.
Intermediate Jacobians and Hodge structures of moduli spaces

The mixed Hodge structure on the low degree cohomology of the moduli space of vector bundles on a curve is studied. Analysis of the third cohomology yields a new proof of a Torelli theorem.
Metastasis: tumor cells becoming MENAcing

During breast cancer metastasis cells emigrate from the primary tumor to the bloodstream, and this carries them to distant sites where they infiltrate and sometimes form metastases within target organs. These cells must penetrate the dense extracellular matrix comprising the basement membrane of the mammary duct/acinus and migrate toward blood and lymphatic vessels, processes that mammary tumor cells execute primarily using epidermal growth factor (EGF)-dependent protrusive and migratory activity. Here, we focus on how the actin regulatory protein Mena affects EGF-elicited movement, invasion and metastasis. Recent findings indicate that, in invasive migratory tumor cells, Mena isoforms that endow heightened sensitivity to EGF and increased protrusive and migratory abilities are upregulated, whereas other isoforms are selectively downregulated. This change in Mena isoform expression enables tumor cells to invade in response to otherwise benign EGF stimulus levels and could offer an opportunity to identify metastatic risk in patients.
Improving nearest neighbor rule with a simple adaptive distance measure

The k-nearest neighbor rule is one of the simplest and most attractive pattern classification algorithms. However, it faces serious challenges when patterns of different classes overlap in some regions in the feature space. In the past, many researchers developed various adaptive or discriminant metrics to improve its performance. In this paper, we demonstrate that an extremely simple adaptive distance measure significantly improves the performance of the k-nearest neighbor rule.
Flips, flops and foreclosures: anatomy of a real estate bubble

Purpose – This paper aims to examine the anatomy of a real estate bubble. In the process, the paper identifies three phases of the market's evolution: flips, flops and foreclosures. An examination of the Las Vegas real estate market illustrates the three phases.Design/methodology/approach – The paper examines transaction data from the metropolitan Las Vegas area (Clark County) from 1994 to 2009. The first part of the analysis identifies the three phases of the bubble and is descriptive in nature. This is followed by more formal tests of Granger causality.Findings – In the early part of the sample, a large percentage of transactions are speculative or “flips” causing prices to rapidly increase. Eventually, flipping loses its profitability and over the last three years, there is an increasing number of foreclosures leading to falling prices. The descriptive analysis of the Las Vegas market is augmented with causality tests which show that prices were the driving force behind all three phases in the market's...
Modeling Hubble Space Telescope flight data by Q-Markov cover identification

This Paper presents a state space model for the Hubble space telescope under the influence of unknown disturbances in orbit. This model was obtained from flight data by applying the Q-Markov Covariance Equivalent Realization identification algorithm. This state space model guarantees the match of the first Q Markov parameters and covariance parameters of the Hubble system. The flight data were partitioned into high and low frequency components for more efficient Q-Markov Cover modeling, to reduce some computational difficulties of the Q-Markov Cover algorithm. This identification revealed more than 20 lightly-damped modes within the bandwidth of the attitude control system. Comparisons with the analytical (TREETOPS) model are also included.
Demand for differentiated products: Price and advertising evidence from the U.S. beer market

Abstract This paper employs a nation-wide sample of supermarket scanner data to estimate a large brand-level demand system for beer in the U.S. using the Distance Metric method of Pinkse, Slade and Brett [Pinkse, J., Slade, M., Brett, C., 2002. Spatial price competition: a semiparametric approach. Econometrica 70, 1111–1155]. Unlike previous studies, this work estimates the own- and cross-advertising elasticities in addition to price elasticities. Positive and negative cross-advertising elasticities imply the presence of both cooperative and predatory effects of advertising expenditures across brands; however, the former effect appears to dominate suggesting that advertising increases the overall demand for beer. We discuss the implications of these results in this industry.
Fused salt synthesis of materials for IR windows

Abstract A fused salt technique for preparing nearly spherical, narrow size distribution particles of NaLaS2 is discussed. The method, a one-step synthesis and Ostwald ripening, appears to have great potential for complex, nonoxide materials.
Imaging with Charge-Coupled Devices

The small size and low power requirements, along with the potential for building up large focal planes from charge-coupled devices and charge-injection devices, make these devices very useful for space applications. This paper discusses the state-of-the-art in visible and infrared imaging devices which make use of the charge-coupled concept. Self-scanned two-dimensional CCD and CID arrays for visible imaging are compared. The use of CCD's in the time-delay-and-integration mode in mechanically scanned applications is described. Finally, the use of CCD's and CID's in infrared focal-plane arrays are discussed.
Synergy of inhibition of DNA synthesis in human bone marrow by azidothymidine plus deficiency of folate and/or vitamin B12?

The effect of azidothymidine (Zidovudine, AZT) on pyrimidine (thymidine, deoxyuridine, and thymidine triphosphate) incorporation into DNA in folate- and/or vitamin B12-deficient and normal human bone marrow cells was studied to investigate whether such vitamin deficiency affects susceptibility to AZT-induced hematologic toxicity. Bone marrow cells from 12 patients were studied: 5 had folate and/or vitamin B12 deficiency; 7 controls included 5 with anemia related to chronic disease and 2 with iron deficiency. At 0.2 microM AZT (3 hr, 37 degrees C), the approximate pharmacologic serum trough level, pyrimidine incorporation into DNA was suppressed by 12 to 19% in folate- and/or vitamin B12-deficient cells and by 16 to 23% in normal cells. At 2.0 microM AZT (3 hr, 37 degrees C), the approximate pharmacologic serum peak level, this was suppressed by 15 to 40% in folate- and/or vitamin B12-deficient cells and by 32 to 47% in controls. Deoxyuridine incorporation into DNA was inhibited significantly greater than thymidine at 2.0 microM AZT (3 hr, 37 degrees C) in both groups. Inhibition of deoxyuridine incorporation was not reversed with methyltetrahydrofolate or vitamin B12. There tended to be less striking suppression by AZT of deoxyuridine incorporation into DNA in bone marrow cells from vitamin B12-deficient patients, which was made more striking by adding vitamin B12. This suggests that some of what passes for "AZT damage" to bone marrow cells may in fact be coincident deficiency of vitamin B12. AZT inhibition of DNA synthesis in 3 hr bone marrow cultures is relatively consistent in a variety of hematologic disorders. As approximately two-thirds of AIDS patients appear to be in negative balance with respect to folate and/or vitamin B12, the fact that AZT-induced inhibition of pyrimidine incorporation into DNA is occurring in cells which may be megaloblastic, i.e., in a state of impaired DNA synthesis, suggests that these cells may be more susceptible to AZT toxicity. The data also support the notion that AZT inhibition results predominantly from termination of DNA chain elongation. Whether folate or vitamin B12 supplementation may partially overcome apparent "AZT inhibition" of DNA synthesis (hematologic toxicity) and whether the benefit of such therapy exceeds the risk will require further study.
The boarding experience from the patient perspective: the wait

Study objective We sought to better understand the experience of being a boarder patient. Methods We conducted a qualitative study between March and August 2012 to examine the experience of boarding in an urban, teaching hospital emergency department (ED). We included boarder patients and selected patients based on a convenience sample. Interviews were semistructured, consisting of eight main open-ended questions. Interviews were transcribed; codes were generated and then organised into categorises and subsequently into one theme. We concluded analysis when we achieved thematic saturation. Our institutional review board approved this study. Results Our final sample included 18 patients. The average age was 62.3 years. Patients characterised waiting as central to their experience as a boarder patient. One patient stated, “Well if you have to wait for a bed you have to wait for a bed, it9s terrible.” Three categories exemplified this waiting experience: (1) there was often lack of communication; (2) patients experienced frustration during this waiting period; and yet (3) patients often differentiated the experience of waiting from the care they were receiving. Conclusions Being a boarder patient was characterised as a waiting experience associated with poor communication and frustration. However, patients may still differentiate their feelings towards the wait from those towards the medical care they are receiving. Our data add more reason to eradicate the practice of ED boarding.
Quantum logic as motivated by quantum computing

§1. Introduction. Our understanding of Nature comes in layers, so should the development of logic. Classic logic is an indispensable part of our knowledge, and its interactions with computer science have recently dramatically changed our life. A new layer of logic has been developing ever since the discovery of quantum mechanics. G. D. Birkhoff and von Neumann introduced quantum logic in a seminal paper in 1936 [1]. But the definition of quantum logic varies among authors (see [2]). How to capture the logic structure inherent in quantum mechanics is very interesting and challenging. Given the close connection between classical logic and theoretical computer science as exemplified by the coincidence of computable functions through Turing machines, recursive function theory, and λ-calculus, we are interested in how to gain some insights about quantum logic from quantum computing. In this note we make some observations about quantum logic as motivated by quantum computing (see [5]) and hope more people will explore this connection. The quantum logic as envisioned by Birkhoff and von Neumann is based on the lattice of closed subspaces of a Hilbert space, usually an infinite dimensional one. The quantum logic of a fixed Hilbert space ℍ in this note is the variety of all the true equations with finitely many variables using the connectives meet, join and negation. Quantum computing is theoretically based on quantum systems with finite dimensional Hilbert spaces, especially the states space of a qubit ℂ2. (Actually the qubit is merely a convenience.
Very short gamma-ray bursts and primordial black hole evaporation

Abstract The search for high energy gamma-ray bursts from primordial black holes has continued for the past 20 years. No positive evidence for the existence of evaporating black holes has been reported. We discuss a very interesting group of gamma-ray bursts of very short time duration and an increasing hard spectrum from the published BATSE catalog. We point out that the trend, i.e., anti-correlation of hardness ratio versus gamma-ray burst duration, would be expected if some of the short gamma-ray bursts came from black holes evaporation. We also study the spatial distribution of these event and a possible fireball model of the PBH evaporation. Future tests for the black hole hypothesis is suggested.
Memory conserving efficient methods for solving large sets of stiff differential equations

Solution of large systems of stiff differential equations by the most widely used method, that of Gear, is limited by its requirement for the presence in memory of a Jacobian matrix, which may become intolerably large. Methods of alleviating this situation, believed to be broadly applicable, have been worked out with large metabolic models. One general tactic is to remove from the set of differential equations elements which can be represented instead by algebraic equations: rate equations for enzymes and equilibrium relations for very rapid reactions. Another general tactic is to store efficiently only a part of the sparse Jacobian matrix containing the non-zero elements, which requires the presence of a preprocessor, using algorithms which are given in the paper. The Jacobian matrix may sometimes be represented by a diagonal approximation; this works better with the algebraic methods. Examples of the savings are given. These methods have been incorporated into BIOSSIM, a machine-independent simulation language designed for large biological systems, and in our hands have considerably reduced the cost and difficulty of solving large systems of stiff differential equations.
Adrenocortical, β-endorphin and behavioral responses to graded stressors in differentially reared rats

Abstract Isolation rearing has long been suspected to alter hormonal and behavioral responses to stress. Two experiments were conducted to test the hypothesis that isolates are more timid or fearful than socially reared rats when exposed to novel test environments. In both, isolate response to 3 graded stressors was compared to that of socially-reared rats. In the first experiment, animals were handled, shocked or not treated prior to testing to produce three levels of conditioned fear. They were then tested on four paradigms previously shown sensitive to conditioned fear: open field activity, emergence latency, auditory startle, and latency to accept food from the experimenter. In the second experiment, rats were given a 0-, 5- or 20-min forced swim, then sacrificed for analysis of plasma corticosterone and pituitary and hypothalamic β-endorphin. It was found that isolates showed little evidence of enhanced behavioral timidity, although rearing effects were seen on all 4 behavioral measures. Plasma corticosterone levels increased in a graded fashion over the course of the forced swim, but there was no effect of rearing conditions. While there were no effects of rearing or stress on hypothalamic β-endorphin, pituitary β-endorphin content was lower in females than in males, and isolate males had lower pituitary endorphin than social males. In summary, these experiments provide no evidence that isolation rearing produces a primary, global increase in fearfulness, but identify several behavioral and hormonal differences associated with differential housing in rats.
Ensemble multiple sequence alignment via advising

The multiple sequence alignments computed by an aligner for different settings of its parameters, as well as the alignments computed by different aligners using their default settings, can differ markedly in accuracy. Parameter advising is the task of choosing a parameter setting for an aligner to maximize the accuracy of the resulting alignment. We extend parameter advising to aligner advising, which in contrast chooses among a set of aligners to maximize accuracy. In the context of aligner advising, default advising selects from a set of aligners that are using their default settings, while general advising selects both the aligner and its parameter setting. In this paper, we apply aligner advising for the first time, to create a true ensemble aligner. Through cross-validation experiments on benchmark protein sequence alignments, we show that parameter advising boosts an aligner's accuracy beyond its default setting for virtually all of the standard aligners currently used in practice. Furthermore, aligner advising with a collection of aligners further improves upon parameter advising with any single aligner, though surprisingly the performance of default advising on testing data is actually superior to general advising due to less overfitting to training data. The new ensemble aligner that results from aligner advising is significantly more accurate than the best single default aligner, especially on hard-to-align sequences. This successfully demonstrates how to construct out of a collection of individual aligners, a more accurate ensemble aligner.
Towards the understanding of coatings on rate performance of LiFePO4

Abstract Stoichiometric and non-stoichiometric LiFePO 4 nanoparticles (sub 100 nm) were synthesized and compared to carbon coated LiFePO 4 particles (super 100 nm) of similar electrode composition for rate performance. The materials were characterized by X-ray diffraction (XRD) and high resolution transition electron microscopy (HRTEM) where amorphous layers ( 4 primary particles. Secondary particles of stoichiometric and non-stoichiometric sub 100 nm particles were confirmed by TEM and scanning electron microscopy (SEM). All three materials display similar particle size distributions as measured with a particle size analyzer and an SEM, indicating that the sub 100 nm particles form secondary particles of approximately the same size as the carbon coated super 100 nm particles. The electronic conductivity measurements of each material indicate that the non-stoichiometric LiFePO 4 measures between 4.5 × 10 −5 and 2.18 × 10 −4 S cm −1 , 8 orders of magnitude lower than the conductivity of the carbon coated super 100 nm LiFePO 4 . Rate tests of the electrodes demonstrate faster charge and discharge capability as the level of conductive additive in the electrodes approaches 15 wt%. All three materials demonstrate solid state diffusion limitations: electrodes of the non-stoichiometric and the carbon coated material both show extreme high rate performance with the addition of 15% carbon additive. A simple calculation indicates that this is the level of carbon additive needed to completely coat particles of 100 nm in size.
Efficient Algorithms for Renewable Energy Allocation to Delay Tolerant Consumers

We investigate the problem of allocating energy from renewable sources to flexible consumers in electricity markets. We assume there is a renewable energy supplier that provides energy according to a time-varying (and possibly unpredictable) supply process. The plant must serve consumers within a specified delay window, and incurs a cost of drawing energy from other (possibly non-renewable) sources if its own supply is not sufficient to meet the deadlines. We formulate two stochastic optimization problems: The first seeks to minimize the time average cost of using the other sources (and hence strives for the most efficient utilization of the renewable source). The second allows the renewable source to dynamically set a price for its service, and seeks to maximize the resulting time average profit. These problems are solved via the Lyapunov optimization technique. Our resulting algorithms do not require knowledge of the statistics of the time-varying supply and demand processes and are robust to arbitrary sample path variations.
Uniformly bounded information and social choice

Abstract The set of alternatives is infinite. If social welfare function f satisfies the Pareto criterion and there is a positive integer β such that for each pair of alternatives, { a , b } , there exists a set S ( a , b ) of at most β alternatives such that a and b can be socially ordered on the basis of the profile of preferences restricted to just S ( a , b ) , then there are arbitrarily large finite subsets of X within which f is dictatorial on a rich sub-domain of profiles.
Multirate multicast switching networks

This paper investigates multirate multicast Clos switching network which is nonblocking in a wide sense, where a compatible multicast request is guaranteed to be routed without disturbing the existing network if all requests have conformed to a given routing scheme. The routing strategy discovers (2.875n − 1) min (k + r1/k) + 1 middle switches sufficient for any multirate multicast requests, whereas strictly nonblocking multirate switching networks requires infinite number of middle switches if the range of weights can be widely distributed.
Shaping Twenty-first-century Civil Rights Advocacy: Latinos in Metro Atlanta

This article chronicles the Mexican American Legal Defense and Educational Fund’s civil rights history in Atlanta and the Southeast from 2000 to 2009 and beyond. It draws on testimonies of MALDEF officials, as well as pertinent historical, social science, and legal scholarship and media accounts, to reveal changing regional Latino migration and settlement patterns and emerging twenty-first-century legal advocacy strategies. Also covered are organized responses to state and local anti-immigrant ordinances passed after September 11, 2001, resistance to residential and workplace discrimination faced by suburban undocumented immigrants, and the fragile nature of coalitions in the contemporary Latino civil rights movement.
Causes of decadal subsurface cooling in the tropical Indian Ocean during 1961–2000

[1] The vertical structure of temperature change in the Indian Ocean (IO) during 1961–2000 indicates that a region of tropical thermocline cooling accompanies the upper level warming. Results from data analysis and ocean general circulation model experiments suggest that the cooling signals exceed the cross-data and cross-model differences. Spatial patterns of the temperature trend above 200 m resemble the negative IO dipole structure, with the strongest cooling occurring in the western-central basin south of the equator. The upper thermocline cooling is mainly caused by enhanced Ekman pumping velocity, which shoals the thermocline. The enhanced upwelling is consistent with the strengthened Southern subtropical cell. Enhanced equatorial westerly winds contribute to the negative dipole pattern. Remote forcing from the Pacific may contribute to the cooling below 200 m and further south.
Bump-type foil bearing structural stiffness : Experiments and predictions

Gas foil bearings (FB) satisfy many of the requirements noted for novel oil-free turbomachinery. However, FB design remains largely empirical, in spite of successful commercial applications. The mechanical structural characteristics of foil bearings, namely stiffness and damping, have been largely ignored in the archival literature. Four commercial bump-type foil bearings were acquired to measure their load capacity under conditions of no shaft rotation. The test bearings contain a single Teflon-coated foil supported on 25 bumps. The nominal radial clearance is 0.036mm for a 38mm journal. A simple test setup was assembled to measure the FB deflections resulting from static loads. The tests were conducted with three shafts of increasing diameter to induce a degree of preload into the FB structure. Static measurements show nonlinear FB deflections, varying with the orientation of the load relative to the foil spot weld. Loading and unloading tests evidence hysteresis. The FB structural stiffness increases as the bumps-foil radial deflection increases (hardening effect). The assembly preload results in notable stiffness changes, in particular for small radial loads. A simple analytical model assembles individual bump stiffnesses and renders predictions for the FB structural stiffness as a function of the bump geometry and material, dry-friction coefficient, load orientation, clearance and preload. The model predicts well the test data, including the hardening effect. The uncertainty in the actual clearance (gap) upon assembly of a shaft into a FB affects most of the predictions.
Delay analysis for max weight opportunistic scheduling in wireless systems

We consider the delay properties of max-weight opportunistic scheduling in a multi-user ON/OFF wireless system, such as a multi-user downlink or uplink. It is well known that max-weight scheduling stabilizes the network (and hence yields maximum throughput) whenever input rates are inside the network capacity region. We show that when arrival and channel processes are independent, average delay of the max-weight policy is order-optimal, in the sense that it does not grow with the number of network links. While recent queue-grouping algorithms are known to also yield order-optimal delay, this is the first such result for the simpler class of max-weight policies. We then consider multi-rate transmission models and show that average delay in this case typically does increase with the network size due to queues containing a small number of ldquoresidualrdquo packets.
A comparative analysis of disk scheduling policies

Five well-known scheduling policies for movable head disks are compared using the performance criteria of expected seek time (system oriented) and expected waiting time (individual I/O request oriented). Both analytical and simulation results are obtained. The variance of waiting time is introduced as another meaningful measure of performance, showing possible discrimination against individual requests. Then the choice of a utility function to measure total performance including system oriented and individual request oriented measures is described. Such a function allows one to differentiate among the scheduling policies over a wide range of input loading conditions. The selection and implementation of a maximum performance two-policy algorithm are discussed.