cssi/SciSciGPT-SciSciNet huggingface dataset:
The outer source of pickup ions and anomalous cosmic rays

[1] The traditionally accepted source of Anomalous Cosmic Rays (ACRs) is neutral atoms penetrating the heliosphere from the local interstellar cloud (LIC). The ACR composition should be depleted in easily ionized atoms such as C, Si, and Fe. However, significant fluxes of these ions are observed in ACRs and their source has not been previously identified. We show that there is an “outer source” of pickup ions, and hence ACRs, caused by sputtered atoms (subsequently ionized and picked up by the solar wind) from small grains generated via collisions of objects in the Edgeworth-Kuiper Belt. The outer source accounts for the abundance and composition of the additional population of ACRs. The discovery that ACRs are generated from material in the Edgeworth-Kuiper Belt provides an exciting new tool for understanding the mass distribution and composition of the Edgeworth-Kuiper Belt, and for probing the plasma-dust interactions in stellar environments.
Confusion errors in astrometry and counterpart association

In very crowded fields, the modulation of the background by the sea of unresolved faint sources induces centroid shifts. The errors increase with the number of sources per beam. Even the most optimistic simulations of imaging data show that position errors can become severe (on the order of the beam size) at flux levels at which images contain 1/50 to 1/15 sources per beam, depending on the slope of the number-flux relation d log N/d log S. These problems are expected to be significant for recent observations of faint submillimeter sources and may be the reason that some sources appear to lack optical counterparts.
Super-Eddington Fluxes from Thin Accretion Disks?

Radiation pressure-dominated accretion disks are predicted to exhibit strong density inhomogeneities on scales much smaller than the disk scale height as a result of the nonlinear development of photon-bubble instability. Radiation would escape from such a "leaky" disk at a rate higher than that predicted by standard accretion disk theory. The disk scale height is then smaller than that of a similar disk without small-scale inhomogeneities, and the disk can remain geometrically thin even as the flux approaches and exceeds the Eddington limit. An idealized one-zone model for disks with radiation-driven inhomogeneities suggests that the escaping flux could exceed LEdd by a factor of up to ~10-100, depending on the mass of the central object. Such luminous disks would develop strong mass loss, but the resulting decrease in accretion rate would not necessarily prevent the luminosity from exceeding LEdd. We suggest that the observed "ultraluminous X-ray sources" are actually thin, super-Eddington accretion disks orbiting stellar-mass black holes and need not indicate the existence of a class of intermediate-mass black holes.
Evaluating the Evidence for Hormesis: A Statistical Perspective

It is possible to account for hormesis under current regulatory guidelines by invoking criteria for departure from default risk assessment procedures. However, past experience suggests that it will be difficult to amass enough evidence for hormesis in an individual case to permit departure from default procedures. Accordingly, hormesis is likely to be important in agency risk assessments only if guidelines are modified to incorporate hormesis as a default assumption. This could be appropriate if hormesis is determined to be a universal or near-universal phenomenon. Although there is ample evidence that hormesis occurs in many specific situations, the overall prevalence of hormesis is very difficult to evaluate based on currently available data. The lack of a valid statistical test for hormesis is a major limitation when evaluating evidence for hormesis. The attempts at estimating the prevalence of hormesis reviewed herein did not adequately control for false positives and/or may have had inadequate power ...
Testing the Disk Regulation Paradigm with Spitzer Observations. II. A Clear Signature of Star-Disk Interaction in NGC 2264 and the Orion Nebula Cluster

Observations of pre-main-sequence star rotation periods reveal slow rotators in young clusters of various ages, indicating that angular momentum is somehow removed from these rotating masses. The mechanism by which spin-up is regulated as young stars contract has been one of the longest standing problems in star formation. Attempts to observationally confirm the prevailing theory that magnetic interaction between the star and its circumstellar disk regulates these rotation periods have produced mixed results. In this paper, we use the unprecedented disk identification capability of the Spitzer Space Telescope to test the star-disk interaction paradigm in two young clusters, NGC 2264 and the Orion Nebula Cluster (ONC). We show that once mass effects and sensitivity biases are removed, a clear increase in the disk fraction with period can be observed in both clusters across the entire period range populated by cluster members. We also show that the long-period peak (P ~ 8 days) of the bimodal distribution observed for high-mass stars in the ONC is dominated by a population of stars possessing a disk, while the short-period peak (P ~ 2 days) is dominated by a population of stars without a disk. Our results represent the strongest evidence to date that star-disk interaction regulates the angular momentum of these young stars. This study will make possible quantitative comparisons between the observed period distributions of stars with and without a disk and numerical models of the angular momentum evolution of young stars.
The Formation of Cataclysmic Variables with Brown Dwarf Secondaries

The present-day formation of cataclysmic variables (CVs) with brown dwarf (BD) secondaries (0.013 M? ? Ms ? 0.075 M?) is investigated using a population synthesis technique. Results from the latest, detailed models for BDs have been incorporated into the population synthesis code. The present-day orbital period distribution of zero-age CVs (ZACVs) that form with BD secondaries is calculated. For our models, we find that ZACVs with BD secondaries have orbital periods in the range 46 minutes to 2.5 hr. We also find that ZACVs with BD secondaries comprise 18% of the total, present-day ZACV population. In addition, we find that 80% of ZACVs with BD secondaries have orbital periods shorter than 78 minutes. This implies that 15% of the present-day ZACV population should have orbital periods shorter than the observed orbital period minimum for CVs. We also investigate the dependence of the present-day formation rate of CVs with BD secondaries on the assumed value of the common envelope efficiency parameter, ?CE, for three different assumed mass ratio distributions in zero-age main-sequence (ZAMS) binaries. Surprisingly, we find that the common envelope process must be extremely inefficient (?CE < 0.1) in order for CVs with BD secondaries not to be formed. Finally, we find that the progenitor binaries of ZACVs with BD secondaries have ZAMS orbital separations of smaller than 3 AU and ZAMS primary masses between ~1 and 10 M?, with ~75% of the primary masses of smaller than ~1.6 M?. Interestingly, these ranges in orbital separation and primary mass place the majority of the progenitor binaries within the so-called brown dwarf desert. The implications of these results are discussed in the context of V485 Cen and 1RXS J232953.9+062814, the only known CVs with orbital periods shorter than the period minimum, CVs above the period minimum that are strongly suspected of containing BD secondaries (such as WZ Sge), common envelope evolution involving very low mass secondaries, and the BD mass function in ZAMS binaries.
Volatile species retention during metallic fuel casting

Abstract Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.
Resolution of the wavefront set using continuous shearlets

It is known that the Continuous Wavelet Transform of a distribution f decays rapidly near the points where f is smooth, while it decays slowly near the irregular points. This property allows the identification of the singular support of f. However, the Continuous Wavelet Transform is unable to describe the geometry of the set of singularities of f and, in particular, identify the wavefront set of a distribution. In this paper, we employ the same framework of affine systems which is at the core of the construction of the wavelet transform to introduce the Continuous Shearlet Transform. This is defined by SH ψ f(a,s,t) = (fψ ast ), where the analyzing elements ψ ast are dilated and translated copies of a single generating function ψ. The dilation matrices form a two-parameter matrix group consisting of products of parabolic scaling and shear matrices. We show that the elements {ψ ast } form a system of smooth functions at continuous scales a > 0, locations t ∈ R 2 , and oriented along lines of slope s ∈ R in the frequency domain. We then prove that the Continuous Shearlet Transform does exactly resolve the wavefront set of a distribution f.
X-Ray Emission from the Pre-planetary Nebula Henize 3-1475

We report the first detection of X-ray emission in a pre-planetary nebula, He 3-1475. Pre-planetary nebulae are rare objects in the short transition stage between the asymptotic giant branch (AGB) and planetary nebula evolutionary phases, and He 3-1475, characterized by a remarkable S-shaped chain of optical knots, is one of the most noteworthy members of this class. Observations with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory show the presence of compact emission coincident with the brightest optical knot in this bipolar object, which is displaced from the central star by 2'.7 along the polar axis. Model fits to the X-ray spectrum indicate an X-ray temperature and luminosity, respectively, of (4.3-5.7) x 10(exp 6) K and (4 +/- 1.4) x 10(exp 31) (D/5 kpc)(exp 2) ergs s(exp -1) respectively. Our 3 sigma upper limit on the luminosity of compact X-ray emission from the central star in He 3-1475 is approximately equal to 5 x 10(exp 31) (D/5 kpc)(exp 2) ergs s(exp -1). The detection of X-rays in He 3-1475 is consistent with models in which fast collimated post-AGB outflows are crucial to the shaping of nebulae; we discuss such models in the context of our observations.
Decomposing social indicators using distributional data

Are the poor less healthy? Does public health spending matter more to them? The authors decompose aggregate health indicators using a random coefficients model in which the aggregates are regressed on the population distribution by subgroups, taking account of the statistical properties of the error term and allowing for other determinants of health status, including public health spending. This also allows them to test possible determinants of the variation in the underlying subgroup indicators. They implement the approach with data on health outcomes and poverty measures for 35 developing countries. The authors find that poor people have appreciably worse health status on average than others - and that differences in public health spending tend to matter more to the poor. This is probably because the nonpoor are in a better position to buy private health care.
La3Cu2VO9: A surprising variation on the YAlO3 structure-type with 2D copper clusters of embedded triangles

Abstract La3Cu2VO9 crystallizes in a heretofore unknown superstructural variation of the rare-earth hexagonal structure (P63/mmc) for ABO3 stoichiometries as characterized by X-ray, neutron and electron diffraction. The alternating hexagonal layers of LaO6/3 and (Cu/V)O3/3 resemble those of YAlO3, except that the copper and vanadium order to create an a 13 ×a 13 ×c supercell with P63/m symmetry. The B-cation coordination environments accommodate copper and vanadium in a two to one molar ratio. The CuII lattice consists of nine atom clusters of triangles in triangles similar to a kagome lattice. The phase is paramagnetic from 5 to 370 K with three temperature regimes that correspond closely to 1/9, 4/9, and 9/9 spins per copper.
Concise synthesis of (+/-)-rhazinilam through direct coupling.

A concise synthesis of rhazinilam through direct, palladium-catalyzed, intramolecular coupling is described.
On information flow and feedback in relay networks

We consider wireless relay networks where a source node communicates to a destination node with the help of multiple intermediate relay nodes. In wireless, if a node can send information to another node, typically it can also receive information from that node. Therefore, inherently there are many possibilities for feeding back information in wireless networks. However, transmissions are not isolated but usually subject to broadcast and interference. In this paper, we ask the following question: Can the information transfer in both directions of a link be critical to maximizing the end-to-end communication rate in such networks? Equivalently, could one of the directions in each bidirected link (and more generally at least one of the links forming a cycle) be shut down and the capacity of the network still be approximately maintained? Our main result is to show that in any arbitrary Gaussian relay network with bidirected edges and cycles, we can always identify a directed acyclic subnetwork that approximately maintains the capacity of the original network. The edges of this subnetwork can be identified as the information carrying links, and the remaining links as feedback, which can only provide limited contribution to capacity.
A Comparison of Trade Execution Costs for NYSE and NASDAQ-Listed Stocks

We compare average trade execution costs during 1994 for sets of large, medium, and small capitalization stocks listed on the New York and NASDAQ stock markets. All measures of execution costs examined, including quoted bid-ask spreads, effective spreads (which allow for executions within the quotes), and realized spreads (which measure price reversal after trades), are larger for NASDAQ-listed than for NYSE-listed stocks. The differentials in average trading costs across exchanges are greater for medium and small capitalization issues than for large capitalization stocks and are greater for small compared to large trades. These differentials cannot be attributed to cross-exchange differences in the adverse se? lection costs of market-making. Furthermore, we find no evidence that average execution costs on NASDAQ declined after the publicized events of May 1994.
Silylene transfer to α-keto esters and application to the synthesis of γ-lactones

Disubstituted α-hydroxy acids have been synthesized by metal-catalyzed silylene transfer to α-keto esters. A range of substituents are tolerated in the transformation with the exception of branched groups at the vinylic position. The α-hydroxy acid products can be converted into γ-lactones using a variety of lactonization conditions.
Thermochemistry and kinetics of the reaction of methyl mercaptan with iodine

The gas-phase reaction CH3SH + I2 has been studied spectrophotometrically over the temperature range of 476–604 K. It was found that the reaction undergoes H abstraction by I at ≤575 K, leading to the formation of MeSI and followed by a secondary reaction which leads to the formation of MeSSMe: Taking into consideration the effect of reaction (2), the equilibrium constant K1 (554 K) has been evaluated to be 0.025 ± 0.004. This value was combined with the estimated values S (CH3SI, g) = 73.7 ± 1.0 eu and 〈ΔC〉 = 0.87 ± 0.3 eu to obtain ΔH = 4.03 ± 0.73 kcal/mol. This yields ΔH (CH3SI, g) = 7.16 ± 0.73 kcal/mol when combined with known thermochemical values for CH3SH, HI, and I2. A kinetic study was vitiated by the concurrent heterogeneous reaction of MeSH and I2 at lower temperatures and the rather complicated chemistry occurring at elevated temperatures. However, attempts at measuring rate constants at 554 K lead to a lower limit of ΔH (CH3S·, g) ≥ 29.5 ± 2 kcal/mol when an estimated value of A = 1010.8 ± 0.2 L/mol·s for the reactionc is used. DH (CH3S–I) is estimated to be 49.3 ± 1.7 kcal/mol. The bond strengths of some divalent sulfurs and the reaction mechanisms are discussed. A crude estimate of DH0(H–CH2SH) = 96 ± 1 kcal has been obtained from the kinetic data.
Formation of Vinyl Halides via a Ruthenium-Catalyzed Three-Component Coupling

The ruthenium-catalyzed three-component coupling of an alkyne, an enone, and halide ion to form E- or Z-vinyl halides has been investigated. Through systematic optimization experiments, the conditions effecting the olefin selectivity were examined. In general, more polar solvents such as DMF favored the formation of the E-isomer, and less polar solvents such as acetone favored formation of the Z-isomer. The optimized conditions for the formation of E-vinyl chlorides were found to be the use of cyclopentadienyl ruthenium (II) cyclooctadiene chloride, stannic chloride pentahydrate as a cocatalyst, and for a chloride source, either ammonium chloride in DMF/water mixtures or tetramethylammonium chloride in DMF. A range of several other ruthenium (II) catalysts was also shown to be effective. A wide variety of vinyl chlorides could be formed under these conditions. Substrates with tethered alcohols or ketones either five or six carbons from the alkyne portion gave instead diketone or cyclohexenone products. Fo...
GPS in dynamic monitoring of long-period structures

Abstract Global Positioning System (GPS) technology with high sampling rates (∼10 samples per second) allows scientifically justified and economically feasible dynamic measurements of relative displacements of long-period structures—otherwise difficult to measure directly by other means, such as the most commonly used accelerometers that require post-processing including double integration. We describe an experiment whereby the displacement responses of a simulated tall building are measured clearly and accurately in real-time. Such measurements can be used to assess average drift ratios and changes in dynamic characteristics, and therefore can be used by engineers and building owners or managers to assess the building performance during extreme motions caused by earthquakes and strong winds. By establishing threshold displacements or drift ratios and identifying changing dynamic characteristics, procedures can be developed to use such information to secure public safety and/or take steps to improve the performance of the building.
How a strongly irreducible Heegaard splitting intersects a handlebody

Abstract In [Topology Appl. 90 (1998) 135] Scharleman showed that a strongly irreducible Heegaard splitting surface Q of a 3 -manifold M can, under reasonable side conditions, intersect a ball or a solid torus in M in only a few possible ways. Here we extend those results to describe how Q can intersect a handlebody in M .
Transitional Justice in Iraq: Learning the Hard Way

The relationship between transitional justice and democracy is fraught and complex, and nowhere more so than in Iraq since the fall of Saddam Hussein. Iraq has experienced a range of transitional justice initiatives, including the trial and execution of its former leader, purges of the civil service and the military, and a series of reconciliation conferences. Yet democracy has not fully taken root and violence continues to plague many parts of the nation on a regular basis. This article argues that initiatives aimed at changing the structure of society – including but not limited to constitutionalism, frequent elections and the development of an independent judiciary – are more likely than purely symbolic efforts to contribute to the consolidation of democracy in the long term. It is these structural developments that have the greatest potential to transform society into a true democracy under the rule of law.
A mimicry of an acute coronary syndrome.

Background: A 79-year-old woman was out in the garden having lunch on a hot summer day. She developed stabbing chest pains, more severe on her left side, associated with radiation down her left arm. Severity was 7 out of 10. There was no relief of pain with glyceryl trinitrate spray. Risk factors for ischaemic heart disease include hyperlipidaemia, being an ex-smoker (40 years), no history of diabetes or hypertension. There was a family history of her father having a myocardial infarction at the age of 54. Echocardiogram (ECG) revealed widespread deep symmetrical T-wave inversion in the chest leads and lateral limb leads. Investigations: The patient’s serum creatine kinase level was 180 IU/litre (normal range 30–135), troponin I level was 6.56 g/litre (normal range 0–0.10), D-dimer was negative and random serum cholesterol level was 5.3 mmol/litre (3.8–5.2). Significant coronary stenoses were excluded. A left ventriculogram revealed a hyperkinetic base and a dyskinetic apical region of the left ventricle. Echocardiography showed normal valves, basal septal hypertrophy and a dilated akinetic apex, with the region of akinesia spanning more than the arterial territory. Diagnosis: Takotsubo cardiomyopathy. Management: Treatment with aspirin, angiotensin-converting enzyme (ACE) inhibitor, β blocker and a statin
Models of Short-Time Qubit Decoherence

We compare approaches to evaluation of decoherence at low temperatures in two-state quantum systems weakly coupled to the environment. By analyzing an exactly solvable model, we demonstrate that a non-Markovian approximation scheme yields good quality estimates of the reduced density matrix for time scales appropriate for evaluation of quantum computing designs.
Oblivious RAM simulation with efficient worst-case access overhead

Oblivious RAM simulation is a method for achieving confidentiality and privacy in cloud computing environments. It involves obscuring the access patterns to a remote storage so that others, including even the manager of that storage, cannot infer information about its contents. Existing solutions typically yield small amortized overheads for achieving this goal, but also yield huge variations in access times, depending on when they occur. In this paper, we show how to deamortize oblivious RAM simulations, so that each access takes a worst-case bounded amount of time.
Islamic Medicine: 1000 Years Ahead of Its Times

DOI: http://dx.doi.org/10.5915/13-1-11925 Within a century after the death of Prophet Muhammad (peace be upon him), the Muslims not only conquered new lands, but also became scientific innovators with originality and productivity. They hit the source ball of knowledge over the fence to Europe. By the ninth century, Islamic medical practice had advanced from talisman and theology to hospitals with wards, doctors who had to pass tests, and the use of technical terminology. The then Baghdad General Hospital incorporated innovations which sound amazingly modern. The fountains cooled the air near the wards or those afflicted with fever; the insane were treated with gentleness; and at night the pain of the restless was soothed by soft music and storytelling. The prince and pauper received identical attention: the destitute upon discharge received five gold pieces to sustain them during convalescence. While Paris and London were places of mud streets and hovels, Baghdad, Cairo and Cardoba had hospitals open to both male and female patients; staffed by attendants of both sexes. These medical centers contained libraries, pharmacies, the system of interns, externs, and nurses. There were mobile clinics to reach the totally disabled, the disadvantaged and those in remote areas. There were regulations to maintain quality control on drugs. Pharmacists became licensed professionals and were pledged to follow the physician's prescriptions. Legal measures were taken to prevent doctors from owning or holding stock in a pharmacy. The extent to which Islamic medicine advanced in the fields of medical education, hospitals, bacteriology, medicine, anesthesia, surgery, pharmacy, ophthalmology, psychotherapy and psychosomatic diseases are presented briefly.
Transfer theorems and asymptotic distributional results for m-ary search trees

We derive asymptotics of moments and identify limiting distributions, under the random permutation model on m-ary search trees, for functionals that satisfy recurrence relations of a simple additive form. Many important functionals including the space requirement, internal path length, and the so-called shape functional fall under this framework. The approach is based on establishing transfer theorems that link the order of growth of the input into a particular (deterministic) recurrence to the order of growth of the output. The transfer theorems are used in conjunction with the method of moments to establish limit laws. It is shown that: (i) for small toll sequences (tn) [roughly, tn = O(n1/2)] we have asymptotic normality if m ≤ 26 and typically periodic behavior if m ≥ 27; (ii) for moderate toll sequences [roughly, tn = ω(n1/2) but tn = o(n)] we have convergence to nonnormal distributions if m ≤ m0 (where m0 ≥ 26) and typically periodic behavior if m ≥ m0 + 1; and (iii) for large toll sequences [roughly, tn = ω(n)] we have convergence to nonnormal distributions for all values of m. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2005Research for both authors supported by NSF Grants DMS-9803780 and DMS-0104167, and by The Johns Hopkins University's Acheson J. Duncan Fund for the Advancement of Research in Statistics.Research supported by NSF Grant 0049092 and carried out primarily while this author was affiliated with what is now the Department of Applied Mathematics and Statistics at The Johns Hopkins University.
Self-disturbance and schizophrenia: Structure, specificity, pathogenesis (Current issues, New directions)

Abstract This paper offers an overview and clarification of the ipseity-disturbance or self-disorder hypothesis regarding schizophrenia, with focus on some recent and recommended research and theoretical refinements. There is need to expand research and theorizing in several directions—in order to: 1, specify more precisely what is truly distinctive in the schizophrenia spectrum, 2, explore internal structure and explanatory potential of this purported disturbance of minimal- or core-self experience, 3, generate testable hypotheses concerning pathogenetic pathways and psychotherapeutic interventions. Comparative studies can make a crucial scientific contribution. Some recent, exploratory studies are described: published reports were examined for alterations of self-experience in conditions outside the schizophrenia spectrum—mania, psychotic depression, and depersonalization disorder—and in one unusual attitudinal stance: intense introspection (as refined in early 20th century psychological research). Remarkable similarities (e.g., alienation/reification of thoughts and bodily experiences, fading of self and world) as well as some important differences (e.g., absence, outside schizophrenia, of severe erosion of minimal self-experience or real confusion of self and other) in types of self-anomalies were found. These support but also refine the ipseity-disturbance model. Future research should treat self-experience as an independent variable, manipulating and measuring this dimension (in both schizophrenic and non-schizophrenic populations) to study its associations with anomalies of cognition, affect, expression, and neural functioning already identified in schizophrenia. The self-disorder model offers an integrative and dynamic view of schizophrenia congruent with recent trends in cognitive neuroscience and consistent with the heterogeneous, varying, and holistic nature of this enigmatic illness.
Radiation pressure in massive star formation

Stars with masses of >~ 20 solar masses have short Kelvin times that enable them to reach the main sequence while still accreting from their natal clouds. The resulting nuclear burning produces a huge luminosity and a correspondingly large radiation pressure force on dust grains in the accreting gas. This effect may limit the upper mass of stars that can form by accretion. Indeed, simulations and analytic calculations to date have been unable to resolve the mystery of how stars of 50 solar masses and up form. We present two new ideas to solve the radiation pressure problem. First, we use three-dimensional radiation hydrodynamic adaptive mesh refinement simulations to study the collapse of massive cores. We find that in three dimensions a configuration in which radiation holds up an infalling envelope is Rayleigh-Taylor unstable, leading radiation driven bubbles to collapse and accretion to continue. We also present Monte Carlo radiative transfer calculations showing that the cavities created by protostellar winds provides a valve that allow radiation to escape the accreting envelope, further reducing the ability of radiation pressure to inhibit accretion.
Crossovers and Phase Coherence in Cuprate Superconductors

Abstract High temperature superconductivity is a property of doped antiferromagnetic insulators. The electronic structure is inhomogeneous on short length and time scales, and, as the temperature decreases, it evolves via two crossovers, before long range superconducting order is achieved. Except for overdoped materials, pairing and phase coherence occur at different temperatures, and phase fluctuations determine both T c and the temperature dependence of the superfluid density for a wide range of doping. A mechanism for obtaining a high pairing scale in a short coherence length material with a strong poorly-screened Coulomb interaction is described.
Antimicrobial activity of triethylammonium chloride‐N‐substituted N′‐cyano‐O‐(triphenylstannyl)‐isourea Complexes

The triethylammonium chloride complexes of N-substituted N′-cyano-O-(triphenylstannyl)isoureas were generally found to be better antifungal and antibacterial agents than the uncomplexed compounds.
Spontaneously arising red cells with a McLeod-like phenotype in normal donors.

Abstract Very few human genes can be used to identify spontaneous inactivating somatic mutations. We hypothesized that because the XK gene is X-linked, it would be easy to identify spontaneously arising red cells with a phenotype resembling the McLeod syndrome, which results from inherited XK mutations. Here, by flow cytometry, we detect such phenotypic variants at a median frequency of 9 × 10 −6 in neonatal cord blood samples and 39 × 10 −6 in healthy adults ( p = 0.004). It may be possible to further investigate the relationship between aging, mutations, and cancer using this approach.
STRUCTURE GENERATION BY IRRADIATION: WHAT CAN GLIMPSE TEACH US ABOUT THE ISM STRUCTURE?

Diffuse emission in the mid-infrared shows a wealth of structure, which lends itself to high-resolution structure analysis of the interstellar gas. A large part of the emission comes from polycyclic aromatic hydrocarbons (PAHs), excited by nearby ultraviolet sources. Can the observed diffuse emission structure be interpreted as column density structure?Wediscussthisquestionwiththehelpofasetof modelmolecularcloudsbathedintheradiationfieldofa nearby O star. The correlation strength between column density and ‘‘observed’’ flux density strongly depends on theabsolutevolumedensityrangeintheregion.Shadowingandirradiationeffectsmaycompletelyalter theappearance of an object. Irradiation introduces additional small-scale structure, and it can generate structures resembling shells around H ii regions in objects that do not possess any shell-like structures whatsoever. Nevertheless, with some effort, structural information about the underlying interstellar medium can be retrieved. In the more diffuse regime [n(Hi)P100cm � 3 ],fluxdensitymapsmaybeusedtotracethe3Ddensitystructureof thecloudviadensitygradients. Thus, while caution definitely is in order, mid-infrared surveys such as GLIMPSE will provide quantitative insight into the turbulent structure of the interstellar medium. Subject headingg dust, extinction — infrared: ISM — ISM: structure — methods: numerical — radiative transfer — turbulence 1. THE PROBLEM
Active vibration control of a smart pultruded fiber-reinforced polymer I-beam

Advanced and innovative materials and structures are increasingly used in civil infrastructure applications. By combining the advantages of composites and smart sensors and actuators, active or smart composite structures can be created and be efficiently adopted in practical structural applications. This paper presents results on active vibration control of pultruded fiber-reinforced polymer (FRP) composite thin-walled I-beams using smart sensors and actuators. The FRP I-beams are made of E-glass fibers and polyester resins. The FRP I-beam is in a cantilevered configuration. The PZT (lead zirconate titanate) type of piezoelectric ceramic patches are used as smart sensors and actuators. These patches are surface bonded near the cantilevered end of the I-beam. Utilizing results from modal analyses and experimental modal testing, several active vibration control methods, such as position feedback control, strain rate feedback control and lead compensation, are investigated. Experimental results demonstrate that the proposed methods achieve effective vibration control of FRP I-beams. For instance, the modal damping ratio of the strong direction first bending mode increases by more than 1000% with positive position feedback control.
LUMINOUS RED GALAXY HALO DENSITY FIELD RECONSTRUCTION AND APPLICATION TO LARGE-SCALE STRUCTURE MEASUREMENTS

The nontrivial relationship between observations of galaxy positions in redshift space and the underlying matter field complicates our ability to determine the linear theory power spectrum and extract cosmological information from galaxy surveys. The Sloan Digital Sky Survey (SDSS) luminous red galaxy (LRG) catalog has the potential to place powerful constraints on cosmological parameters. LRGs are bright, highly biased tracers of large-scale structure. However, because they are highly biased, the nonlinear contribution of satellite galaxies to the galaxy power spectrum is large and fingers-of-God (FOGs) are significant. The combination of these effects leads to a ~10% correction in the underlying power spectrum at k = 0.1 h Mpc–1 and ~40% correction at k = 0.2 h Mpc–1 in the LRG P(k) analysis of Tegmark et al., thereby compromising the cosmological constraints when this potentially large correction is left as a free parameter. We propose an alternative approach to recovering the matter field from galaxy observations. Our approach is to use halos rather than galaxies to trace the underlying mass distribution. We identify FOGs and replace each FOG with a single halo object. This removes the nonlinear contribution of satellite galaxies, the one-halo term. We test our method on a large set of high-fidelity mock SDSS LRG catalogs and find that the power spectrum of the reconstructed halo density field deviates from the underlying matter power spectrum at the ≤1% level for k ≤ 0.1 h Mpc–1 and ≤4% at k = 0.2 h Mpc–1. The reconstructed halo density field also removes the bias in the measurement of the redshift space distortion parameter β induced by the FOG smearing of the linear redshift space distortions.
The formyl C–H⋯O hydrogen bond as a critical factor in enantioselective Lewis-acid catalyzed reactions of aldehydes

X-Ray crystallographic studies have provided experimental evidence for the existence of intramolecular formyl C–H hydrogen bonds to oxygen or fluorine ligands in complexes of aldehydes and boron Lewis acids. This type of hydrogen bond can be regarded as ‘induced’ or ‘cooperative’ in the sense that its strength can be expected to increase as the bonding between the formyl oxygen and the Lewis acid becomes stronger. Coplanarity of the formyl group and the metal–X subunit to which it is bound in a five-membered ring effectively restricts rotation about the donor–acceptor bond between the formyl oxygen and the metal center of the Lewis acid, thus creating an additional organizing element in these complexes. This organizing element provides a simple and logical basis for understanding the mechanistic basis for enantioselectivity in many reactions of achiral aldehydes which are catalyzed by chiral Lewis acids. These reactions include aldol, allylation and ene addition to the formyl CO group and Diels–Alder reactions of α,β-unsaturated aldehydes with 1,3-dienes. The idea of the induced formyl C–H hydrogen bond can serve as a guide in the design of new enantioselective catalysts as well as a mechanistic principle for understanding preferred transition state assemblies.
Selective palladium-catalyzed arylation of ammonia: synthesis of anilines as well as symmetrical and unsymmetrical di- and triarylamines.

It is shown that by selection of an appropriate palladium/ligand system, temperature, concentration, and stoichiometry of reagents, ammonia may be selectively arylated to give either anilines, symmetrical di-, or triarylamines. Furthermore different aryl halides may be added sequentially to the reaction mixture, allowing the synthesis of unsymmetrical di- and triarylamines from aryl halides and ammonia in a one-pot protocol
The trouble with orbits: The Stark effect in the old and the new quantum theory ☆

Abstract The old quantum theory and Schrodinger׳s wave mechanics (and other forms of quantum mechanics) give the same results for the line splittings in the first-order Stark effect in hydrogen, the leading terms in the splitting of the spectral lines emitted by a hydrogen atom in an external electric field. We examine the account of the effect in the old quantum theory, which was hailed as a major success of that theory, from the point of view of wave mechanics. First, we show how the new quantum mechanics solves a fundamental problem that one runs into in the old quantum theory with the Stark effect. It turns out that, even without an external field, it depends on the coordinates in which the quantum conditions are imposed which electron orbits are allowed in a hydrogen atom. The allowed energy levels and hence the line splittings are independent of the coordinates used but the size and eccentricity of the orbits are not. In the new quantum theory, this worrisome non-uniqueness of orbits turns into the perfectly innocuous non-uniqueness of bases in Hilbert space. Second, we review how the so-called WKB (Wentzel–Kramers–Brillouin) approximation method for solving the Schrodinger equation reproduces the quantum conditions of the old quantum theory amended by some additional half-integer terms. These extra terms remove the need for some arbitrary extra restrictions on the allowed orbits that the old quantum theory required over and above the basic quantum conditions.
Asymmetric synthesis of 1-Boc-3- and 4-hydroxypyrrolidines

Abstract Lewis Acid-mediated coupling reactions of (5R, 6S)-2-acetoxy-4-(benzyloxycarbonyl)-5,6-diphenyl-2,3,5,6-tetrahydro-4H-1,4-oxazine (2a) with allylsilanes (3a-d) proceeded to give the coupling products (4a-b) with moderate to good stereoselectivity. The coupling products (4a-b) were effectively converted into 1-Boc-3- and 4-hydroxypyrrolidines (8a, syn-b, and c).
Bandwidth and Dynamic Range of a Widely Tunable Josephson Parametric Amplifier

We characterize the signal bandwidth and dynamic range of a recently developed type of Josephson parametric amplifier. These amplifiers consist of a series array of SQUIDs embedded in a microwave cavity. They are narrow band, only amplifying signals close to the cavity's resonance frequency, but the cavity's resonance frequency, and hence the amplified band, can be widely tuned. For a particular realization of these amplifiers we measure how the signal bandwidth depends on amplifier's gain. We find that the amplitude gain times signal bandwidth is approximately the linewidth of the cavity. In addition we measure the amplifier's dynamic range and saturation power.
A management system for foreign language tests

Abstract Two of the more difficult and time-consuming problems facing the foreign language teacher is the preparation and administration of quizzes and examinations. Since testing is an integral part of teaching, the problem of designing and implementing accurate, valid examinations is a crucial one. Computers are known for their speed, accuracy and repeatability. The use of the computer solves several problems inherent in test preparation. One can, given a well designed program, relegate the tasks of item selection and the producing of duplicating masters to the computer. Of course, the test items must be entered on the machine originally and proof-read, but once the procedure is done, the computer becomes an ideal storage medium: editing the items is quickly and easily performed. And, since all test items are stored in one place, it is possible to improve the test quality (both by increasing the quality of the test items themselves and by reducing the number of typographical errors) through repeated use with students and the subsequent modification of the computers “item bank” based on the students' performance on the tests.
CONTANGO: Integrated Optimization of SoC Clock Networks

On-chip clock networks are remarkable in their impact on the performance and power of synchronous circuits, in their susceptibility to adverse effects of semiconductor technology scaling, as well as in their strong potential for improvement through better CAD algorithms and tools. Existing literature is rich in ideas and techniques but performs large-scale optimization using analytical models that lost accuracy at recent technology nodes and have rarely been validated by realistic SPICE simulations on large industry designs. Our work offers a methodology for SPICE-accurate optimization of clock networks, coordinated to satisfy slew constraints and achieve best tradeoffs between skew, insertion delay, power, as well as tolerance to variations. Our implementation, called Contango, is evaluated on 45 nm benchmarks from IBM Research and Texas Instruments with up to 50 K sinks. It outperforms all published results in terms of skew and shows superior scalability.
Enhanced imaging of microcalcifications in digital breast tomosynthesis through improved image-reconstruction algorithms.

Purpose: The authors develop a practical, iterative algorithm for image-reconstruction in undersampled tomographic systems, such as digital breast tomosynthesis (DBT). Methods: The algorithm controls image regularity by minimizing the image total p variation (TpV), a function that reduces to the total variation when p=1.0 or the image roughness whenp=2.0. Constraints on the image, such as image positivity and estimated projection-data tolerance, are enforced by projection onto convex sets. The fact that the tomographic system is undersampled translates to the mathematical property that many widely varied resultant volumes may correspond to a given data tolerance. Thus the application of image regularity serves two purposes: (1) Reduction in the number of resultant volumes out of those allowed by fixing the data tolerance, finding the minimum image TpV for fixed data tolerance, and (2) traditional regularization, sacrificing data fidelity for higher image regularity. The present algorithm allows for this dual role of image regularity in undersampled tomography. Results: The proposed image-reconstruction algorithm is applied to three clinical DBT data sets. The DBT cases include one with microcalcifications and two with masses. Conclusions: Results indicate that there may be a substantial advantage in using the present image-reconstruction algorithm for microcalcification imaging.
Fourier transform over finite field and identities between Gauss sums

This paper is a sequel to [7]. Here we study identities for the Fourier transform of "elementary functions" over finite fields containing "exponentials" of rational monomial functions. It turns out that these identities are governed by monomial identities between Gauss sums. We show that similar to the case of complex numbers such identities correspond to linear relations between certain divisors on the space of multiplicative characters.
New genome-wide methods bring more power to yeast as a model organism.

A collection of 6,000 mutant yeast strains spanning nearlyevery gene offers new promise for identifying human genes involved incellular responses to drugs, radiation and other treatments.
Moveout analysis for transversely isotropic media with a tilted symmetry axis

Most existing work on reflection moveouts in anisotropic media is restricted to a relatively simple model - laterally homogeneous transversely isotropic media with a vertical symmetry axis (VTi). Recently, it has been recognized that anisotropy may distort not only moveout from horizontal reflectors, but also the dip dependence of normal-moveout (NMO) velocity and, therefore, the resuIts of dip-moveout (DMO) processing.
Fourier transform spectra of overtone bands of HCN from 5400 to 15100 cm−1

Abstract The absolute intensities and vibration-rotation constants of 26 overtone and combination bands of HCN are reported. The dynamic range for the absolute intensity measurements is nearly one million to one. Absorption spectra of HCN from 5400 to 15100 cm−1 were obtained using the Fourier transform spectrometer at the Kitt Peak National Solar Observatory with optical path lengths up to 432 m. The frequencies of 1346 assigned HCN lines were used to derive vibration-rotation constants for 23 bands (14 Σ-Σ, 4 Π-Π, 4 Π-Σ, and 1 Σ-Π) of H12C14N, 3 bands (Σ-Σ) of H13C14N, and 2 bands (Σ-Σ) of H12C15N. These new band origin and rotational constant data have been combined with existing data given in the literature to derive an improved set of vibrational (ω, x, and y) constants and rovibrational (α and γ) constants for HCN. The vibrational dependence of the centrifugal distortion constants has also been examined. One thousand thirtysix derived line areas were used to determine absolute intensities for all 28 bands. Four weak stretch-only bands were observed for the first time: the (300)-(000), the (201)-(000), the (301)-(000) and the (202)-(000). Such data should be an important aid in accurately determining the CN contribution to the potential and dipole moment functions. Finally, we present a comparison of 13 of the measured absolute overtone intensities (stretching states only) with recent ab initio results.