cssi/SciSciGPT-SciSciNet huggingface dataset:
TFRC-CR: An equation-based transport protocol for cognitive radio networks

Abstract Reliable and high throughput data delivery in cognitive radio networks remains an open challenge owing to the inability of the source to quickly identify and react to changes in spectrum availability. The window-based rate adaptation in TCP relies on acknowledgments (ACKs) to self trigger the sending rate, which are often delayed or lost owing to intermittent primary user (PU) activity, resulting in an incorrect inference of congestion by the source node. This paper proposes the first equation-based transport protocol based on TCP Friendly Rate Control for Cognitive Radio, called as TFRC-CR, which allows immediate changes in the transmission rate based on the spectrum-related changes in the network environment. TFRC-CR has the following unique features: (i) it leverages the recent FCC mandated spectrum databases with minimum querying overhead, (ii) it enables fine adjustment of the transmission rate by identifying the instances of true network congestion, as well as (iii) provides guidelines on when to re-start the source transmission after a pause due to PU activity. TFRC-CR is evaluated through an extensive set of module additions to the ns-2 simulator which is also released for further investigation by the research community.
Macroeconomic variables and the sovereign risk premia in EMU, non-EMU EU, and developed countries

This project studies and models key macroeconomic variables and their impact on sovereign risk premia across select European economies and developed countries. The sample is divided into three groups of countries: those in the European Monetary Union (EMU); the standalone economies outside the EMU but members of the broader European Union (EU); and other developed economies. The main subject of examination across all three groups is the impact of macroeconomic variables on sovereign borrowing costs. EU countries have experienced high financial stress and a rapid rise in the credit default swaps (CDS) spreads during the EMU debt crisis. A nonlinear vector smooth transition autoregressive model is applied to investigate such a regime change in the finance-output link using sovereign CDS and industrial production index. The paper finds that regime-switching takes place rather suddenly in most EMU countries. The study concludes that due to the potential spillover effects in the EU as a whole, the individual country macroeconomic indicators were less reflected in the financial stress and spillover and contagion effects became dominant.
Processes that account for the ozone maximum at the mesopause

[1] The presence of a maximum in ozone density and mixing ratio in the mesopause region has been known for several decades although the measurement database is still quite limited. This ozone layer is formed in the vicinity of the maximum in atomic oxygen number density. In this paper, we present simulations of the ozone maximum from a three-dimensional dynamical chemical model. Ozone variability is dominated by the diurnal cycle in ozone, which fluctuates between low concentrations in sunlight and high concentrations in darkness. However, the diurnal variability also has strong contributions from atmospheric tides and from slow changes in chemical concentrations following sunrise and sunset. In this study, we find that the magnitude of the ozone secondary maximum is closely tied to the temperature. The very low temperatures at the mesopause accelerate the formation of ozone and inhibit the loss. This factor and the location of the atomic oxygen density maximum both contribute in approximately equal measure to determining the altitude of the ozone layer. The magnitude of the nighttime ozone maximum is sensitive to the eddy and molecular diffusion rates primarily through the influence of these processes on the concentration of hydrogen.
Melt Processing of YBa2Cu3O7‐x

Sintering YBa2Cu3O7-x bulk forms at 1050°C followed by annealing at 980°C causes the development of a thick oriented surface layer (Lotgering factor = 0.7). The thickness of the layer depends on the thermal treatment, which is a two-step sintering process. Firing at 1050°C for 2.5 h followed by 30 h at 980°C leads to the development of a 0.1-mm-thick surface layer, with clear indication that longer annealing would result in a thicker film. Some orientation develops during un-axial compaction of the powders. Lotgering orientation factor calculation from X-ray diffraction analysis. SEM, and TEM were used to characterize the microstructure of these samples. Tc was similar to that of conventionally processed high-density samples, between 83 and 87 K. Some thermal treatments resulted in samples that displayed high resistivity above Tc, possibly caused by segregation of Cu to the grain boundaries.
Introduction to D-Branes

D-branes are string theory solitons defined by boundary conditions on open strings that end on them. They play an important role in the non-perturbative dynamics of string theory and have found a wide range of applications. These lectures give a basic introduction to D-branes and their dynamics.
QQ Plots, Random Sets and Data from a Heavy Tailed Distribution

The QQ plot is a commonly used technique for informally deciding whether a univariate random sample of size n comes from a specified distribution F. The QQ plot graphs the sample quantiles against the theoretical quantiles of F and then a visual check is made to see whether or not the points are close to a straight line. For a location and scale family of distributions, the intercept and slope of the straight line provide estimates for the shift and scale parameters of the distribution respectively. Here we consider the set S n of points forming the QQ plot as a random closed set in ℝ2. We show that under certain regularity conditions on the distribution F,S n converges in probability to a closed, non-random set. In the heavy tailed case where 1 − F is a regularly varying function, a similar result can be shown, but a modification is necessary to provide a statistically sensible result since typically F is not completely known.
The Radial Velocity and Mass of the White Dwarf of EX Hydrae Measured with Chandra

We present the first detection of orbital motion in the cataclysmic variable EX Hydrae based on X-ray data from the Chandra X-Ray Observatory. The large collecting area of the telescope and the high resolution of the HETG spectrometers allow for an unprecedented velocity accuracy of {approx}km s{sup -1} in the X-ray wavelength regime. We find an emission line velocity amplitude of 58.2{+-}3.7 km s{sup -1} and infer a white dwarf mass of 0.49{+-}0.13 M{sub {circle_dot}}, in good agreement with previous studies using optical, ultraviolet, and far ultraviolet data.
Ethics in Obstetrics and Gynecology

This paper provides an overview of ethical issues in obstetrics and gynecology. We first define two basic ethical principles, beneficence and respect for autonomy. We first apply these principles to gynecologic practice, emphasizing the role of informed consent. We then apply these principles to obstetric practice, utilizing the concept of the fetus as a patient and identifying its clinical implications for directive versus non-directive counseling for fetal benefit.
Incidence, prevalence, and evidence: Scientific problems in epidemiologic statistics for the occurrence of cancer☆

Abstract Major changes in policy for health, nutrition, and industrial safety have been proposed because of the "epidemic of apprehension" produced by statistics for the occurrence rates of cancer. The statistical information, however, contains gross violations of epidemiologic principles and scientific standards for credible evidence. The calculations often depend on an improper linkage of numerators and denominators; and the calculated rates, assembled from reports of overtly detected cases of cancer, represent neither incidence nor prevalence. Many of the secular or regional changes in rates are due to corresponding changes in the availability and dissemination of diagnostic technology, but the technologic changes have not been adequately evaluated or investigated. Improvements will require drastically altered approaches to the use of death certificates, tumor registries, and clues from necropsy data.
Controls on porphyroblast size along a regional metamorphic field gradient

Garnet-bearing schists from the Waterville Formation of south-central Maine provide an opportunity to examine the factors governing porphyroblast size over a range of metamorphic grade. Three-dimensional sizes and locations for all garnet porphyroblasts were determined for three samples along the metamorphic field gradient spanning lowest garnet through sillimanite grade, using high-resolution X-ray computed tomography. Comparison of crystal size distributions to previous data sets obtained by stereological methods for the same samples reveals significant differences in mode, mean, and shape of the distributions. Quantitative textural analysis shows that the garnets in each rock crystallized in a diffusion-controlled nucleation and growth regime. In contrast to the typical observation of a correlation between porphyroblast size and position along a metamorphic field gradient, porphyroblast size of the lowest-grade specimen is intermediate between the high- and middle-grade specimens’ sizes. Mean porphyroblast size does not correlate with peak temperatures from garnet-biotite Fe-Mg exchange thermometry, nor is post-crystallization annealing (Ostwald Ripening) required to produce the observed textures, as was previously proposed for these rocks. Robust pseudosection calculations fail to reproduce the observed garnet core compositions for two specimens, suggesting that these calc-pelites experienced metasomatism. For each of these two specimens, Monte Carlo calculations suggest potential pre-metasomatism bulk compositions that replicate garnet core compositions. Pseudosection analyses allow the estimation of the critical temperatures for garnet growth: ∼481, ∼477, and ∼485°C for the lowest-garnet-zone, middle-garnet-zone, and sillimanite-zone specimens, respectively. Porphyroblast size appears to be determined in this case by a combination of the heating rate during garnet crystallization, the critical temperature for the garnet-forming reaction and the kinetics of nucleation. Numerical simulations of thermally accelerated, diffusion-controlled nucleation, and growth for the three samples closely match measured crystal size distributions. These observations and simulations suggest that previous hypotheses linking the garnet size primarily to the temperature at the onset of porphyroblast nucleation can only partially explain the observed textures. Also important in determining porphyroblast size are the heating rate and the distribution of favorable nucleation sites.
Assisted chaotic inflation in higher dimensional theories

Abstract We address the problem of the large initial field values in chaotic inflation and propose a remedy in the framework of the so-called assisted inflation. We demonstrate that a 4-dimensional theory of multiple, scalar fields with initial field values considerably below the Planck scale, can give rise to inflation even though none of the individual scalar fields are capable of driving inflation. The problems arising from the presence of possible non-renormalizable interactions is therefore removed. As a concrete example of a theory with multiple scalar fields, we consider a (4+ d )-dimensional field theory of a single, non-interacting massive scalar field whose KK modes play the role of the assisted sector. For the KK modes to assist inflation, the extra dimensions must have a size larger than the inverse (4D) Planck scale.
Controlled fabrication and electrical properties of long quasi-one-dimensional superconducting nanowire arrays.

We report a general method for reliably fabricating quasi-one-dimensional superconducting nanowire arrays, with good control over nanowire cross section and length, and with full compatibility with device processing methods. We investigate Nb nanowires with individual nanowire cross sectional areas that range from bulklike to 10 × 11 nm, and with lengths from 1 to 100 μm. Nanowire size effects are systematically studied. In particular, a comprehensive investigation of influence of nanowire length on superconductivity is reported for the first time. All results are interpreted within the context of phase-slip models.
Production of hydrogen by electrocatalysis: making the H–H bond by combining protons and hydrides

Generation of hydrogen by reduction of two protons by two electrons can be catalysed by molecular electrocatalysts. Determination of the thermodynamic driving force for elimination of H2 from molecular complexes is important for the rational design of molecular electrocatalysts, and allows the design of metal complexes of abundant, inexpensive metals rather than precious metals ("Cheap Metals for Noble Tasks"). The rate of H2 evolution can be dramatically accelerated by incorporating pendant amines into diphosphine ligands. These pendant amines in the second coordination sphere function as protons relays, accelerating intramolecular and intermolecular proton transfer reactions. The thermodynamics of hydride transfer from metal hydrides and the acidity of protonated pendant amines (pK(a) of N-H) contribute to the thermodynamics of elimination of H2; both of the hydricity and acidity can be systematically varied by changing the substituents on the ligands. A series of Ni(II) electrocatalysts with pendant amines have been developed. In addition to the thermochemical considerations, the catalytic rate is strongly influenced by the ability to deliver protons to the correct location of the pendant amine. Protonation of the amine endo to the metal leads to the N-H being positioned appropriately to favor rapid heterocoupling with the M-H. Designing ligands that include proton relays that are properly positioned and thermodynamically tuned is a key principle for molecular electrocatalysts for H2 production as well as for other multi-proton, multi-electron reactions important for energy conversions.
Another Short and Elementary Proof of Strong Subadditivity of Quantum Entropy

A short and elementary proof of the joint convexity of relative entropy is presented, using nothing beyond linear algebra. The key ingredients are an easily verified integral representation and the strategy used to prove the Cauchy-Schwarz inequality in elementary courses. Several consequences are proved in a way which allows an elementary proof of strong subadditivity in a few more lines. Some expository material on Schwarz inequalities for operators and the Holevo bound for partial measurements is also included.
Ring opening metathesis approach to the isoprostanes

Abstract A new route to enantiomerically pure isoprostane analogs is described. Ring opening metathesis of bicyclo[3.2.0]heptene ( 3 ) with TBS-protected allyl alcohol generates the syn -disubstituted cyclopentyl product (±)- 4 . Diene (±)- 4 can be converted in a straightforward manner to aldehyde (±)- 7 . Asymmetric alkylations of aldehyde (±)- 7 yield a series of enantiomerically pure isoprostane analogs ( 2a – d ).
An elegant Lambert algorithm

Of the many techniques extant for solving the two-body, two-point, time-constrained orbital boundary-value problem, commonly known today as Lambert's problem, none is more conceptually elegant than the classical method devised by Gauss. The simplicity of Gauss' method would certainly have been attractive to the modern astrodynamicist except for two major flaws — the method is singular for a transfer angle of 180 degrees and the convergence rate is extremely slow when that angle is not very small. In this paper a new algorithm is described which exactly parallels both the mechanics and the elegant simplicity of the classical one but is completely devoid of the two basic faults of the original. The equations of the new method are universal and not singular for the 180 degree transfer. (They are singular for a complete revolution through 360 degrees but this should not be cause for great alarm.) Furthermore, convergence is both remarkably rapid and almost uniform as well as being essentially independent of the initial guess. It should further be emphasized that all of the advantages of Gauss' method are inherent in the new method — notably, the preservation of numerical accuracy for small transfer angles (of the order of 2 or 3 degrees, for example).
Reinforcement Learning for Characterizing Hysteresis Behavior of Shape Memory Alloys

The ability to actively control the shape of aerospace structures has spawned the use of shape memory alloy actuators. These actuators can be used for morphing or shape control by modulating their temperature, which is effectively done by applying a voltage difference across their length. Characterization of this temperature–strain relationship is currently done using constitutive models, which is time and labor intensive. Shape memory alloys also contain both major and minor hysteresis loops. Understanding the hysteresis is crucial for practical applications, and characterization of the minor hysteresis loops, which map the behavior of a wire that is not fully actuated, is not possible using the constitutive method. Numerical simulation using reinforcement learning has been used for determining the temperature–strain relationship and characterizing the major and minor hysteresis loops, and determining a control policy relating applied voltage to desired strain.This paper extends and improves upon the numerical simulation results, using an experimental hardware apparatus and improved reinforcement learning algorithms. Results presented in the paper verify the numerical simulation results for determining the temperature–strain major hysteresis loop behavior, and also determine the relationships of the minor hysteresis loops.
A ferroelectric model for the low emissivity highlands on Venus

A model to explain the low emissivity venusian highlands is proposed utilizing the temperature-dependent dielectric constant of ferroelectric minerals. Ferroelectric minerals are known to occur in alkaline and carbonite rocks, both of which are plausible for Venus. Ferroelectric minerals possess extremely high dielectric constants (10(exp 5)) over small temperature intervals and are only required in minor (much less than 1%) abundances to explain the observed emissivities. The ferroelectric model can account for: (1) the observed reduction in emissivity with increased altitude, (2) the abrupt return to normal emissivities at highest elevations, and (3) the variations in the critical elevation observed from region to region.
CO2 cooling in terrestrial planet thermospheres

The comparative approach to planetary problems is becoming increasingly fruitful as new information from various planetary atmospheres is assimilated. As an example, it is clear that the important problem of CO2 cooling in the Earth’s lower thermosphere is closely tied to the thermospheric heat budgets of Venus and Mars.
Normal MR Imaging Anatomy of the Elbow

The functional complexity achieved at the elbow is a reflection of the sophisticated architecture that embodies this articulation. In addition to challenging anatomic relationships to conceptualize, there are many anatomic variations that exist in the osseous, capsular, and muscular structures. This article offers a detailed description of the structural and imaging anatomy of the elbow, information that establishes the foundation of imaging interpretation of internal derangements.
Electrical measurement of submicrometer contact holes

A technique to measure submicrometer-sized isolated features electrically is described. P.M. Hall's formula (1967-8) modified with an experimentally determined coefficient is used to obtain the hole diameter and the hole area from the electrically measured linewidth with a higher precision than the precision of the linewidth itself. By incorporating a large number of features in a single test structure, a gain in precision of better than 3 nm is shown analytically. The contact hole diameter and the area of the isolated features obtained in this way, were found to be accurate when compared with physical measurements using a scanning electron microscope. The test pattern used is a combination of two basic four-point probe linewidth-measuring structures and two modified ones. The modified structures contain a large number of contact holes in the 10- mu m lines running in the horizontal and vertical directions, which reduce the apparent electrical linewidth. Subtracting the reduced linewidth from that of a solid reference line removes the other contributions to linewidth variation. The size of the contact holes can then be derived from these results. The special test pattern, an analytic expression for interpretation of the results, and hole size data from a variety of exposure dosages are discussed. >
Leading vacuum-polarization contributions to the relation between pole and running masses

Abstract The vacuum-polarization contributions of O(bn−1 σsn) to the relation between the pole-mass M of a quark and the MS parameter m (M) are evaluated by a straightforward method. They are found to approximate very well the exact answer, known through O(αs2), thus providing a simple physical interpretation. Results are also given for the cases when the vacuum-polarization contributions are defined by the pinch technique prescription and specific background field gauges. Assuming that the terms n ⩾ 3 are also dominant, we evaluate M t m t (M t ) , compare the results with those of optimization methods, briefly discuss M b m b (M b ) , and estimate the irreducible errors in the perturbative series. Implications for the electroweak amplitude Δϱ are emphasized. An update of the QCD corrections to this amplitude, including an estimate of the theoretical error, is given.
THE SCIENCE OF CONFINEMENT AND THE GLUEX/HALL D PROJECT AT JEFFERSON LAB

One of the outstanding and fundamental questions in physics is the quantitative understanding of the confinement of quarks and gluons in quantum chromodynamics (QCD). Confinement is a unique feature of QCD. Exotic hybrid mesons manifest gluonic degrees of freedom and their spectroscopy will provide the crucial data needed to test assumptions in lattice QCD and phenomenology leading to confinement. Photo-production is expected to be particularly effective in producing exotic hybrids but data using photon probes are sparse. At Jefferson Lab, plans are underway to use the coherent bremsstrahlung technique to produce a linearly polarized photon beam. A solenoid-based hermetic detector will be used to collected data on meson production and decays with statistics that will exceed the current photoproduction data in hand by several orders of magnitude after the first year of running. In order to reach the ideal photon energy of 9 GeV/c for this mapping of the exotic spectra, the energy of the Jefferson Lab electron accelerator, CEBAF, will be doubled from its current maximum of 6 GeV to 12 GeV. The physics and project are described.
An Experimental Investigation of Retention and Rotation Requirements

We provide results from an experiment designed to assess whether mandatory rotation and/or retention of auditors increases auditors' independence by reducing their willingness to issue reports biased in favor of management. Auditors' reporting is compared across the following four regimes: one that does not require either rotation or retention, a second that requires retention only, a third that requires rotation only, and a fourth that requires both rotation and retention. We find that the rotation requirements in the third and fourth regimes decreased auditor-subjects' willingness to issue biased reports, relative to the two regimes in which rotation was not imposed. In these other two regimes, however, many manager-subjects voluntarily retained the same auditor-subjects over multi-periods. While the long running interactions between manager- and auditor-subjects resulted in more favorable reports by auditor-subjects (a lower level of independence), the established relationships also induced manager-subjects to make higher investments.
Preparation and Antifungal Activity of 3-Iodo- and 6-Iodo-8-quinolinols

3-Iodo- and 6-Iodo-8-quinolinols were prepared and tested against six fungi: Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes in Sabouraud dextrose broth. A comparison with the previously known 5-iodo- and 7-iodo-8-quinolinols showed that the 6-iodo isomer was the most active.
Instabilities in numerical loop quantum cosmology

In this paper, we perform the von Neumann analysis of the difference equations that arise as a result of loop quantum gravity being applied to models of cosmology and black holes. In particular, we study the numerical stability of Bianchi I locally rotationally symmetric (symmetric and non-symmetric constraint) and Schwarzschild interior (symmetric constraint) models, and find that there exist domains over which there are instabilities, generically. We also present explicit evolutions of wave-packets in these models and clearly demonstrate the presence of these instabilities.
Complications of alloderm and dermamatrix for parotidectomy reconstruction.

Background AlloDerm and DermaMatrix are 2 acellular dermal implants currently used by reconstructive surgeons at our institution for reconstruction of parotidectomy defects. We looked at the postoperative complication rates following subcutaneous implantation of these acellular dermal implants for parotid bed reconstruction. Methods A retrospective analysis was conducted following approval by the Institutional Review Board at Vanderbilt University Medical Center. All parotid and reconstructive operations were performed between 2001 and 2009 by 1 of 4 surgeons in the Department of Otolaryngology–Head and Neck Surgery. Data were collected to determine operative variables and postoperative course. Operative variables assessed were tumor type, type of implant used, type of parotidectomy (total or subtotal), and duration of Jackson Pratt (JP) drain placement. Results One hundred patients were analyzed. Sixty-nine AlloDerm implants were associated with 5 complications (7%), whereas 31 DermaMatrix implants were associated with 8 complications (26%) (p = .0107). When comparing total parotidectomies, the complication rate was 1 of 20 for AlloDerm (5%) and 1 of 12 for DermaMatrix (8%) (p = .7061). When looking at subtotal parotidectomies, the incidence of complications was found to be 4 of 49 for AlloDerm (8%) and 7 of 19 for DermaMatrix (37%) (p = .004). Conclusions Our study suggests that DermaMatrix was associated with increased postoperative complications compared to AlloDerm, especially in the subset of patients undergoing subtotal parotidectomy. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Nuclear resonant spectroscopy

Nuclear resonant scattering techniques with synchrotron radiation (SR) are introduced on a basic level. We focus on the theoretical background and on experimental aspects of two popular methods with a widening range of applications, nuclear resonant inelastic x-ray scattering and synchrotron Mossbauer spectroscopy. The inelastic method provides specific vibrational information, e.g., the phonon density of states. The Mossbauer method permits determination of hyperfine interactions. All nuclear resonance techniques take full advantage of the unique properties of SR: intensity, collimation, time structure, and polarization. As a result both methods discussed here have led to novel applications for materials under extreme conditions, proteins with biological functionality, and magnetic nanostructures.
On Grassmannian description of the constrained KP hierarchy

Abstract This note develops an explicit construction of the constrained KP hierarchy within the Sato Grassmannian framework. Useful relations are established between the kernel elements of the underlying ordinary differential operator and the eigenfunctions of the associated KP hierarchy as well as between the related bilinear concomitant and the squared eigenfunction potential.
Organometallic chemistry: Carbon-carbon bonds get a break.

As a rule of thumb, carbon–carbon bonds are not easily broken. But a tungsten complex has been found to break a particularly strong carbon–carbon bond, opening up fresh opportunities for organic synthesis. The transformation of petroleum-derived feedstocks into useful chemicals often requires controllable cleavage of carbon–hydrogen or carbon–carbon bonds. There are many examples achieving this through the oxidative addition of C–H bonds to metal centres, but analogous transformations of C–C bonds are rare. Aaron Sattler and Gerard Parkin show that by using a tungsten centre and exploiting the formation of an unusual ligand, a strong C–C bond can be cleaved. This raises the prospect that many other metal centres with suitable ligands can be developed for the same task, providing new ways of turning feedstocks into valuable chemicals.
Automatic problem detection and documentation in a plasma etch reactor

IC manufacturing involves a large number of complex process steps. There is a probability of a misprocessing error, which may entail severe consequences, in each of these steps. The author describes two software tools, in a single-wafer plasma etcher, that have been developed to minimize the occurrence and maximize the efficiency of diagnosing misprocessing. The first examines the endpoint trace of every wafer and determines if that wafer has seen anomalous processing. If so, the software can terminate the processing of subsequent wafers. The second records the analog values of all the process control parameters during the entire etch process. When these two routines are linked appropriately, it is possible to record these analog values for only those wafers that have seen anomalous processing. This feature provides data for the analysis of the process problem. The procedures minimize the number of wafers that are misprocessed and provide pertinent diagnostic information for those wafers. >
Main Characteristics of Piezo-Magnetization and Their Qualitative Interpretation

Major characteristics of observed effects of uniaxial compression upon magnetization of rocks and assemblages of magnetic minerals are summarized as follows: -(a) uniaxial compression in a magnetic field results in a decrease of magnetization; (b) removal of the magnetic field in presence of the compession causes a decrease of remanence; (c) removal of the compression in presence of the magnetic field causes an increase of magnetization and also an increase of remanence after the magnetic field is taken off. Typical examples of experimental results are shown in Figures 2 and 3.These observed characteristics are interpreted satisfactorily as due to an effect of increased magnetoelastic energy upon irreversible magnetization by a comparatively simple theory based on a model of an assemblage of single domains having uniaxial anisotropy, where the anisotropy energy, K, is subject to a certain distribution function n(2K/Js) with a condition dn/dK≥0.
2-Substituted-4-hydroxymethyltellurophenes from acetylenic epichlorohydrins and sodium telluride

Abstract 2-Substituted-4-hydroxymethyltellurophenes and acetylenic allyl alcohols (enynols) are products from the action of sodium telluride on acetylenic epichlorohydrins. Variation in the degree of reduction of tellurium to telluride ion has a dramatic effect on the ratio of tellurophene to allyl alcohol, either of which may be obtained as the major product.
Synthesis of a chiral dioxo-cyclam derived from L-phenylalanine and its application to olefin oxidation chemistry

Abstract An optically active dioxo-cyclam macrocycle bearing two benzyl side chains derived from phenylalanine has been synthesized; its Ni(II) complex catalyzes the oxidation of olefins using hypochlorite under phase transfer conditions.
Synthesis of the Pyrrolo[2,3-i]isoquinoline Substructure of the Manzamine Family of Alkaloids

Abstract The first synthesis of the tricyclic pyrrolo[2,3-i]isoquinoline substructure of manzamines A, B ,E and F is described. Reductive alkylation of benzoic acid followed by a 3-aza-6-heptenyl radical cyclization gave octahydro-isoquinoline 9. An electrophile initiated cyclization was used to complete construction of the title ring system.
Size Exclusion Chromatography and Related Separation Techniques

Books, Proceedings, and Reviews 252R Theory 252R Band Broadening 253R Calibration 253R General 253R Universal Calibration 253R Round-Robin Studies 253R Automation/Quality Control 254R Packings 254R Inorganic-Based Packings 254R Organic-Based Packings 254R Mobile Phases 254R Non-Size-Exclusion Effects 255R Shear Degradation/Viscosity Effects 255R Aqueous SEC 255R Nonaqueous SEC 255R Detectors 255R Light Scattering 255R Viscometers 256R Combined Light Scattering and Viscometry 256R Interdetector Volume in Multidector SEC 256R Chemiluminescent Nitrogen Detector 257R Density Detector 257R Evaporative Light Scattering 257R Flame Ionization Detector 257R Inductively Coupled Plasma/Atomic Absorption Spectroscopy 257R
Multiverse dark matter: SUSY or axions

The observed values of the cosmological constant and the abundance of Dark Matter (DM) can be successfully understood, using certain measures, by imposing the anthropic requirement that density perturbations go non-linear and virialize to form halos. This requires a probability distribution favoring low amounts of DM, i.e. low values of the PQ scale f for the QCD axion and low values of the superpartner mass scale $$ \tilde{m} $$ for LSP thermal relics. In theories with independent scanning of multiple DM components, there is a high probability for DM to be dominated by a single component. For example, with independent scanning of f and $$ \tilde{m} $$ , TeV-scale LSP DM and an axion solution to the strong CP problem are unlikely to coexist. With thermal LSP DM, the scheme allows an understanding of a Little SUSY Hierarchy with multi-TeV superpartners. Alternatively, with axion DM, PQ breaking before (after) inflation leads to f typically below (below) the projected range of the current ADMX experiment of f = (3 − 30) × 1011 GeV, providing strong motivation to develop experimental techniques for probing lower f.
Room to Maneuver (f)or a Room of One's Own? Practice Theory and Feminist Practice

This comment reflects on the relevance to feminism of the body of work Rosemary Coombe represents as "practice theory." I ask, What are the uses, and limitations, of Coombe's version of practice theory for feminist scholars and activists who see their work as part of an ongoing struggle to empower women?l To anticipate my argument, I answer that practice theory is helpful but not enough. Practicing practice theory alone does not constitute a feminist politics. Feminists must also create normative representations-"powerful stories"-about why what is is simply not good enough, about how things might be better.
Evaluation of light-emitting diodes for signage applications

This paper outlines two parts of a study designed to evaluate the use of light-emitting diodes (LEDs) in channel-letter signs. The first part of the study evaluated the system performance of red LED signs and white LED signs against reference neon and cold-cathode signs. The results show a large difference between the actual performance and potential savings from red and white LEDs. Depending on the configuration, a red LED sign could use 20% to 60% less power than a neon sign at the same light output. The light output of the brightest white LED sign tested was 15% lower than the cold-cathode reference, but its power was 53% higher. It appears from this study that the most efficient white LED system is still 40% less efficient than the cold-cathode system tested. One area that offers a great potential for further energy savings is the acrylic diffuser of the signs. The acrylic diffusers measured absorb between 60% and 66% of the light output produced by the sign. Qualitative factors are also known to play an important role in signage systems. One of the largest issues with any new lighting technology is its acceptance by the end user. Consistency of light output and color among LEDs, even from the same manufacturing batch, and over time, are two of the major issues that also could affect the advantages of LEDs for signage applications. To evaluate different signage products and to identify the suitability of LEDs for this application, it is important to establish a criterion for brightness uniformity. Building upon this information, the second part of the study used human factors evaluations to determine a brightness-uniformity criterion for channel-letter signs. The results show that the contrast modulation between bright and dark areas within a sign seems to elicit the strongest effect on how people perceive uniformity. A strong monotonic relationship between modulation and acceptability was found in this evaluation. The effect of contrast seems to be stronger than that of spatial frequency or background luminance, particularly for contrast modulation values of less than 0.20 or greater than 0.60. A sign with luminance variations of less than 20% would be accepted by at least 80% of the population in any given context.
Double beta decay with vector majorons

Abstract We consider the possibility that neutrinoless double beta decay may occur in models with unbroken lepton number via the emission of a massive gauge boson with electron lepton number −2. We determine the shape of the β β sum energy spectrum as a function of the gauge coupling, independent of model-specific details. We discuss our results in light of the persistent experimental claims that excess events are observed near but below the spectrum endpoint of several elements.
Aromatic inhibitors of dehydroquinate synthase: synthesis, evaluation and implications for gallic acid biosynthesis.

Abstract The role of the active site metal in determining binding to 3-dehydroquinate synthase has been examined. Protocatechuic acid, catechol, and derivatives of these aromatics were synthesized that shared the common element of an ortho dihydroxylated benzene ring. Inhibition constants were determined for each aromatic as well as the variation of this inhibition as a function of whether Co+2 or Zn+2 was the active site metal ion.
Synchrophasor monitoring of single line outages via area angle and susceptance

The area angle is a scalar measure of power system area stress that responds to line outages within the area and is a combination of synchrophasor measurements of voltage angles around the border of the area. Both idealized and practical examples are given to show that the variation of the area angle for single line outages can be approximately related to changes in the overall susceptance of the area and the line outage severity.
Do We Need More Training Data

Datasets for training object recognition systems are steadily increasing in size. This paper investigates the question of whether existing detectors will continue to improve as data grows, or saturate in performance due to limited model complexity and the Bayes risk associated with the feature spaces in which they operate. We focus on the popular paradigm of discriminatively trained templates defined on oriented gradient features. We investigate the performance of mixtures of templates as the number of mixture components and the amount of training data grows. Surprisingly, even with proper treatment of regularization and "outliers", the performance of classic mixture models appears to saturate quickly ($${\sim }10$$~10 templates and $${\sim }100$$~100 positive training examples per template). This is not a limitation of the feature space as compositional mixtures that share template parameters via parts and that can synthesize new templates not encountered during training yield significantly better performance. Based on our analysis, we conjecture that the greatest gains in detection performance will continue to derive from improved representations and learning algorithms that can make efficient use of large datasets.
Time-invariance of the reachable set for linear control problems☆

Abstract Let KT be the set of states reachable at time T (with unconstrained controls) for an autonomous control problem with initial state 0 at t = 0. Suppose the problem is “null controllable at τ,” i.e., every initial state can be controlled to 0 at t = τ. Then KT is independent of T for T ⩾ τ. The result is formulated for nonautonomous problems.
Protein oxidation and aging

Organisms are constantly exposed to various forms of reactive oxygen species (ROS) that lead to oxidation of proteins, nucleic acids, and lipids. Protein oxidation can involve cleavage of the polypeptide chain, modification of amino acid side chains, and conversion of the protein to derivatives that are highly sensitive to proteolytic degradation. Unlike other types of modification (except cysteine oxidation), oxidation of methionine residues to methionine sulfoxide is reversible; thus, cyclic oxidation and reduction of methionine residues leads to consumption of ROS and thereby increases the resistance of proteins to oxidation. The importance of protein oxidation in aging is supported by the observation that levels of oxidized proteins increase with animal age. The age-related accumulation of oxidized proteins may reflect age-related increases in rates of ROS generation, decreases in antioxidant activities, or losses in the capacity to degrade oxidized proteins.
Phenomenology of charmless hadronic B decays

The decays of B mesons to a pair of charmless pseudoscalar mesons ( PP decays) or to a vector and pseudoscalar meson ( V P decays) have been analyzed within the framework of flavor SU(3) symmetry and the Kobayashi-Maskawa mechanism of CP violation. Separate PP and V P fits proved to be successful in describing the experimental data (branching ratios, CP asymmetries and time-dependent parameters). Decay magnitudes and relative weak and strong phases have been extracted from the fits. Values of the weak phase γ were found to be consistent with the current indirect bounds from other analyses of CKM parameters.
Analysis of multicultural meta‐ethical clinical perceptions concerning life and death of patients

Purpose – The prime objective of this article is related to dignified human beings as patients in clinical interventions. The main attention of such a perception focuses on observance of humaneness in relationships among physicians, patients, family members, and community at large. This paper aims to address these issues.Design/methodology/approach – The paper examines in depth, analytical deliberations concerning traditional and modern values of medical care and healthcare knowledge and practices.Findings – Therefore, we need to attest that we live in a global village in which multicultural people must live side‐by‐side, if they desire to peacefully coexist. We must assume that human values are based upon general agreements about ethical issues. Such agreements rely on a framework of equitable treatments of all mankind. Medical ethics is about committed codes and oaths of professional medical authorities to protect natural rights, human rights, and civil rights of patients in clinical interventions. It s...
Rayleigh scattering in rare-gas liquids

Abstract The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the UV in the gas phase, in some cases extrapolated to the wavelength of luminescence. The scattering length may place constraints on the design of some large-scale detectors, using UV luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas liquids is also discussed.
Agricultural Supply Response Under Contract

Agricultural producers typically face considerable production and price risk in their operations. As a result, the role of risk in shaping farm-level decisions has been the focus of much research (e.g., Moschini and Hennessy). But why do risk-averse producers face such risk? In a world of complete markets and perfect information, a profit-maximizing intermediary would provide full insurance to producers. Thus, some aspect of the production and marketing of agricultural commodities must limit the scope for this type of insurance. When considering reasons why growers of fresh produce might face price risk, Hueth and Ligon suggest the possibility of unobserved actions in the provision of quality. If quality cannot be measured perfectly, and some downstream price contains information about a farmer's investment in quality, then conditioning a grower's compensation on this price may help the intermediary to monitor farmer effort. A similar argument holds in the case of production risk: if unobserved actions influence yield, an optimal compensation scheme might expose farmers to considerable production risk in order to provide incentive for high output. This suggests that the type of intermediation available to farmers can have important consequences for the risks that farmers face. Previous analyses of the role of risk in producer decisions make one of two polar assumptions regarding intermediation: either there is none (e.g., Sandmo, Leland), or producers have access to an exogenously specified source of intermediation that may take the form of a futures market (e.g., Holthausen), public or private insurance (e.g., Ramaswami, Babcock and Hennessy), or perhaps a particular government program (e.g., Lin, Chavas and Holt). Although each of these analyses represent important contributions toward an understanding of how producers respond in different risk environments, they are each silent on how the institutions themselves
Exponential Synchronization Rate of Kuramoto Oscillators in the Presence of a Pacemaker

The exponential synchronization rate is addressed for Kuramoto oscillators in the presence of a pacemaker. When natural frequencies are identical, we prove that synchronization can be ensured even when the phases are not constrained in an open half-circle, which improves the existing results in the literature. We derive a lower bound on the exponential synchronization rate, which is proven to be an increasing function of pacemaker strength, but may be an increasing or decreasing function of local coupling strength. A similar conclusion is obtained for phase locking when the natural frequencies are non-identical. An approach to trapping phase differences in an arbitrary interval is also given, which ensures synchronization in the sense that synchronization error can be reduced to an arbitrary level.