cssi/SciSciGPT-SciSciNet huggingface dataset:
Spatial distribution and longitudinal development of deep cortical sulcal landmarks in infants

Sulcal pits, the locally deepest points in sulci of the highly convoluted and variable cerebral cortex, are found to be spatially consistent across human adult individuals. It is suggested that sulcal pits are genetically controlled and have close relationships with functional areas. To date, the existing imaging studies of sulcal pits are mainly focused on adult brains, yet little is known about the spatial distribution and temporal development of sulcal pits in the first 2 years of life, which is the most dynamic and critical period of postnatal brain development. Studying sulcal pits during this period would greatly enrich our limited understandings of the origins and developmental trajectories of sulcal pits, and would also provide important insights into many neurodevelopmental disorders associated with abnormal cortical foldings. In this paper, by using surface-based morphometry, for the first time, we systemically investigated the spatial distribution and temporal development of sulcal pits in major cortical sulci from 73 healthy infants, each with three longitudinal 3T MR scans at term birth, 1 year, and 2 years of age. Our results suggest that the spatially consistent distributions of sulcal pits in major sulci across individuals have already existed at term birth and this spatial distribution pattern keeps relatively stable in the first 2 years of life, despite that the cerebral cortex expands dramatically and the sulcal depth increases considerably during this period. Specially, the depth of sulcal pits increases regionally heterogeneously, with more rapid growth in the high-order association cortex, including the prefrontal and temporal cortices, than the sensorimotor cortex in the first 2 years of life. Meanwhile, our results also suggest that there exist hemispheric asymmetries of the spatial distributions of sulcal pits in several cortical regions, such as the central, superior temporal and postcentral sulci, consistently from birth to 2 years of age, which likely has close relationships with the lateralization of brain functions of these regions. This study provides detailed insights into the spatial distribution and temporal development of deep sulcal landmarks in infants.
Synthesis of Tertiary β-Hydroxy Amides by Enolate Additions to Acylsilanes

The synthesis of tertiary β-hydroxy amides from acylsilanes, acetamides, and electrophiles is described. The addition of amide enolates to acylsilanes generates β-silyloxy homoenolate reactivity by undergoing a 1,2-Brook rearrangement. These unique nucleophiles formed in situ can then undergo smooth addition to alkyl halides, aldehydes, and ketones. Enolates derived from amides are crucial for the success of this process since ketone enolates suffer from internal return of the β-carbanion onto the carbonyl carbon. The use of optically active amide enolates delivers β-hydroxy amide products with good levels of diastereoselectivity (≥10:1).
Finite Combinations of Baire Numbers

Letκ be a regular cardinal. Consider the Bair numbers of the spaces (2θ)κ for variousθ≥κ. Letl be the number of such different Baire numbers. Models of set theory withl=1 orl=2 are known and it is also known thatl is finite. We show here that ifκ>ω, thenl could be any given finite number.
A cobaloxime-mediated radical route to butenolides

Abstract Photolysis of alkyl cobaloximes with maleic anhydride and PhSSPh proceeds via radical alkene addition and subsequent PhSSPh trapping. The product trans 3-phenylthio 4-alkyl succinic anhydrides can be converted by oxidation and thermal syn elimination into 3-substituted maleic anhydrides, which are known to be regioselectively and chemoselectively reduced to produce γ-hydroxybutenolides or butenolides.
Securing QKD Links in the Full Hilbert Space

Many quantum key distribution QKD analyses examine the link security in a subset of the full Hilbert space that is available to describe the system. In reality, information about the photon state can be embedded in correlations between the polarization space and other dimensions of the full Hilbert space in such a way that Eve can determine the polarization of a photon without affecting it. This paper uses the concept of suitability Hockney et al. "Suitability versus Fidelity for Rating Single Photon Guns" to quantify the available information for Eve to exploit, and demonstrate how it is possible for Alice and Bob to fool themselves into thinking they have a highly secure link.
CHARACTERISTICS AND EVOLUTION OF THE MAGNETIC FIELD AND CHROMOSPHERIC EMISSION IN AN ACTIVE REGION CORE OBSERVED BY HINODE

We describe the characteristics and evolution of the magnetic field and chromospheric emission in an active region core observed by the Solar Optical Telescope (SOT) on Hinode. Consistent with previous studies, we find that the moss is unipolar, the spatial distribution of magnetic flux evolves slowly, and that the magnetic field is only moderately inclined. We also show that the field-line inclination and horizontal component are coherent, and that the magnetic field is mostly sheared in the inter-moss regions where the highest magnetic flux variability is seen. Using extrapolations from spectropolarimeter magnetograms, we show that the magnetic connectivity in the moss is different from that in the quiet Sun because most of the magnetic field extends to significant coronal heights. The magnetic flux, field vector, and chromospheric emission in the moss also appear highly dynamic but actually show only small-scale variations in magnitude on timescales longer than the cooling times for hydrodynamic loops computed from our extrapolations, suggesting high-frequency (continuous) heating events. Some evidence is found for flux (Ca II intensity) changes on the order of 100-200 G (DN) on timescales of 20-30 minutes that could be taken as indicative of low-frequency heating. We find, however, that only a small fraction (10%) of our simulated loops would be expected to cool on these timescales, and we do not find clear evidence that the flux changes consistently produce intensity changes in the chromosphere. Using observations from the EUV Imaging Spectrometer (EIS), we also determine that the filling factor in the moss is ~16%, consistent with previous studies and larger than the size of an SOT pixel. The magnetic flux and chromospheric intensity in most individual SOT pixels in the moss vary by less than ~20% and ~10%, respectively, on loop cooling timescales. In view of the high energy requirements of the chromosphere, we suggest that these variations could be sufficient for the heating of "warm" EUV loops, but that the high basal levels may be more important for powering the hot core loops rooted in the moss. The magnetic field and chromospheric emission appear to evolve gradually on spatial scales comparable to the cross-field scale of the fundamental coronal structures inferred from EIS measurements.
NIST programs for calibrations in the far ultraviolet spectral region

The National Institute of Standards and Technology (NIST) serves the growing ultraviolet user community by providing calibration services throughout the spectral range from 2 nm to 400 nm. In this paper we describe the far ultraviolet transfer standard detector program, the NASA-supported Spectrometer Calibration Beamline at the Synchrotron Ultraviolet Radiation Facility, SURF III, and the recent upgrade of the SURF electron storage ring. Several types of transfer standard detectors are issued by NIST in the spectral range from 5 nm to 254 nm; Al2O3 windowless photoemissive devices, CsTe photoemissive devices with integrated MgF2 windows, and radiation-hardened, semiconductive Si photodiodes. The Spectrometer Calibration Beamline makes use of the cathode, undispersed synchrotron radiation from SURF III as a standard of spectral irradiance from 2 nm to 400 nm. The upgrade of SURF has greatly improved the accuracy of calibrations based on SURF, as well as extending the useful spectral range to shorter wavelengths. Taken together, the transfer standard detector program and the calibration beamline at SURF III offer a unique calibration resource for scientists and engineers working in the far ultraviolet spectral region.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. I. HYDRODYNAMICS AND SELF-GRAVITY

We present a new code, CASTRO, that solves the multicomponent compressible hydrodynamic equations for astrophysical flows including self-gravity, nuclear reactions, and radiation. CASTRO uses an Eulerian grid and incorporates adaptive mesh refinement (AMR). Our approach to AMR uses a nested hierarchy of logically rectangular grids with simultaneous refinement in both space and time. The radiation component of CASTRO will be described in detail in the next paper, Part II, of this series.
Using transfer function parameter changes for damage detection of structures

A novel approach is presented for damage detection of large flexible structures by using the parameter change of the transfer function. First, an interval modeling technique, which represents the system uncertainty under the environmental change via the intervals of transfer function parameters, is used to distinguish the structural damage from the environmental change. In this paper a coherence approach is developed for locating the damage position when the structural damage is observed. Only a few sensors are required in using the proposed coherence approach for damage detection. This has the advantage of using the proposed algorithm for practical applications. Also this approach has the flexibility of using the multi-input and multi-output system. A nine-bay truss example is used to demonstrate and verify the approach developed. Nomenclature a, b = denominator and numerator parameters of transfer function C = coherence of the tested system to damage G = interval model g = transfer function k = number of modes m = number of outputs n = number of tests for environmental change p = parameter vector of transfer function R = magnitude ratio of the tested system to damage R, JR = magnitude ratio bounds W = weight of parameter change Wa, W}} = weights of intervals for interval model x,y = unit vectors of Cartesian coordinate system Ap = parameter change vector Superscripts
Parametrization of the hybrid potential for pairs of neutral atoms

The hybrid form is a combination of the Rydberg potential and the London inverse-sixth-power energy. It is accurate at all relevant distance scales and simple enough for use in all-atom simulations of biomolecules. One may compute the parameters of the hybrid potential for the ground state of a pair of neutral atoms from their internuclear separation, the depth and curvature of their potential at its minimum, and from their van der Waals coefficient of dispersion C6.
Comparison of the Manganese Cluster in Oxygen-Evolving Photosystem II with Distorted Cubane Manganese Compounds through X-ray Absorption Spectroscopy

X-ray absorption spectroscopy has been employed to assess the degree of similarity between the oxygen-evolving complex (OEC) in photosystem II (PS II) and a family of synthetic manganese complexes containing the distorted cubane [Mn(4)O(3)X] core (X = benzoate, acetate, methoxide, hydroxide, azide, fluoride, chloride, or bromide). These [Mn(4)(m(3)-O)(3)(m(3)-X)] cubanes possess C(3)(v)() symmetry except for the X = benzoate species, which is slightly more distorted with only C(s)() symmetry. In addition, Mn(4)O(3)Cl complexes containing three or six terminal Cl ligands at three of the Mn were included in this study. The Mn K-edge X-ray absorption near edge structure (XANES) from the oxygen-ligated complexes begin to resemble general features of the PS II (S(1) state) spectrum, although the second derivatives are distinct from those in PS II. The extended X-ray absorption fine structure (EXAFS) of these Mn compounds also displays superficial resemblance to that of PS II, but major differences emerge on closer examination of the phases and amplitudes. The most obvious distinction is the smaller magnitude of the Fourier transform (FT) of the PS II EXAFS compared to the FTs from the distorted cubanes. Curve fitting of the Mn EXAFS spectra verifies the known core structures of the Mn cubanes, and shows that the number of the crucial 2.7 and 3.3 A Mn-Mn distances differs from that observed in the OEC. The EXAFS method detects small changes in the core structures as X is varied in this series, and serves to exclude the distorted cubane of C(3)(v)() symmetry as a topological model for the Mn catalytic cluster of the OEC. Instead, the method shows that even more distortion of the cubane framework, altering the ratio of the Mn-Mn distances, is required to resemble the Mn cluster in PS II.
Persistence of excitation conditions in passive learning control

Abstract This paper analyzes the stability of both the system state and parameter estimates in passive learning control applications. The analysis is valid for any linear in parameter approximator. This class of approximators includes many of those commonly used: radial basis functions, splines, wavelets, certain fuzzy systems, and Cerebellar Model Articulation Controller networks. Stability results are presented for both parametric (known model structure with unknown parameters) and nonparametric (unknown model structure resulting in e-approximation error) adaptive control applications. The main contribution of the article is an analysis of the persistence of excitation conditions required for parameter convergence. In addition, to a general analysis, the article presents a specific analysis pertinent to approximators that are composed of basis elements with local support. In particular, the analysis shows that, as long as a reduced dimension subvector of the regressor vector is persistently exciting, then a specialized form of exponential convergence will be achieved. This condition is critical, since the general persistence of excitation conditions are not practical in most control applications.
FIRST HIGH CONTRAST IMAGING USING A GAUSSIAN APERTURE PUPIL MASK

Placing a pupil mask with a Gaussian aperture into the optical train of current telescopes represents a way to attain high-contrast imaging that potentially improves contrast by orders of magnitude compared to current techniques. We present here the first observations ever using a Gaussian aperture pupil mask (GAPM) on the Penn State near-IR Imager and Spectrograph at the Mount Wilson 100'' telescope. Two nearby stars were observed, Eridani and μ Her A. A faint companion was detected around μ Her A, confirming it as a proper-motion companion. Furthermore, the observed H and K magnitudes of the companion were used to constrain its nature. No companions or faint structure were observed for Eri. We found that our observations with the GAPM achieved contrast levels similar to our coronagraphic images, without blocking light from the central star. The mask's performance also nearly reached sensitivities reported for other ground-based adaptive optics coronagraphs and deep Hubble Space Telescope images but did not reach theoretically predicted contrast levels. We outline ways that could improve the performance of the GAPM by an order of magnitude or more.
Haematological abnormalities in neonatal necrotizing enterocolitis

Objective: Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants born prior to 32 weeks gestation or with a birth weight less than 1500 grams. In this article, we review hematological abnormalities associated with NEC. Methods: A literature search was performed using the databases PubMed, EMBASE, and Scopus, and the electronic archive of abstracts presented at the annual meetings of the Pediatric Academic Societies. Results: Thrombocytopenia, disseminated intravascular coagulation, increased or decreased neutrophil counts, and hemolytic anemia are frequent events in NEC. Conclusions: NEC is associated with several hematological abnormalities, which may play a direct or indirect role in the pathogenesis of gut mucosal injury, and may also carry important prognostic information.
Stability of time-delay systems

This paper gives necessary and sufficient conditions for the stability of time-delay systems of the form \dot{x}(t)=A_{1}x(t)+A_{2}x(t-h) . These new conditions are derived by Lyapunov's direct method through systematic construction of the corresponding "energy" function. This function is known to exist, if a solution P_{1}(0) of the algebraic nonlinear matrix equation A_{2} =e^{[A_{1}+P_{1}(0)]h}P_{1}(0) can be determined.
The self-reporting of psychiatric medications in patients scheduled for elective surgery

Abstract Study Objective: To determine by survey the percentage of patients, over the age of 21 years, reporting for elective surgery who also are taking psychotropic medications. Design: Institution-approved, anonymous survey. Setting: Teaching hospital. Patients: 169 patients who were scheduled for elective surgery. Interventions: After completion of the preoperative evaluation by members of the anesthesia care team, all patients were given an institution-approved survey of medications they were taking in addition to their nonpsychiatric medications. The survey listed 33 drugs known to affect central nervous system neurotransmitters, and included the most commonly prescribed antidepressants, antipsychotics, benzodiazapines, and lithium. Over-the-counter drugs known to affect mood, such as melatonin, also were included in the survey. Patients were not asked the indications for the medications, and no psychiatric questions were asked of the patients. Measurements and Main Results: 300 surveys were distributed, and 169 patients completed the survey for a response rate of 53%. Forty-three percent of all patients who completed the survey admitted to taking one or more of the psychotropic medications. Of these patients, 35% were taking antidepressants, 34% were taking benzodiazapines, 19% were taking combination therapies, and 11% took antipsychotics, lithium, or over-the-counter drugs such as melatonin. Conclusion: The number of patients taking psychotropic medications and who present for elective surgery is high. The anesthetic implications of this drug usage are essentially unknown. Additional study of these medications and their impact on anesthetic care is warranted.
Overview of Fine-Scale Piezoelectric Ceramic/Polymer Composite Processing

In the past two decades, piezoelectric ceramic/polymer composites with different connectivities have been developed for transducer applications such as hydrophones, biomedical imaging, nondestructive testing, and air imaging. Recently, much attention has been given to fine-scale piezoelectric ceramic/polymer composites. These composites allow higher operating frequencies, and thus increased resolution, in medical imaging transducers. In this review, methods for processing fine-scale piezoelectric ceramic/polymer composites are discussed. The current capabilities, strengths, and weaknesses of each method are compared. The importance of spatial scale in composite performance is also reviewed. Several of the processing methods have demonstrated composites with fine-scale ceramic phases (<50 μm), and others have potential to form composites with a ceramic scale of under 20 μm.
Standard Examples as Subposets of Posets

We prove that a poset with no induced subposet Sk (for fixed k≥3) must have dimension that is sublinear in terms of the number of elements.
Impact of dark matter substructure on the matter and weak-lensing power spectra

We explore the effect of substructure in dark matter halos on the power spectrum and bispectrum of matter fluctuations and weak-lensing shear. By experimenting with substructure in a cosmological N = 5123 simulation, we find that when a larger fraction of the host halo mass is in subhalos, the resulting power spectrum has less power at 1 k 100 h Mpc-1 and more power at k 100 h Mpc-1. We explain this effect using an analytic halo model including subhalos, which shows that the 1 k 100 h Mpc-1 regime depends sensitively on the radial distribution of subhalo centers, while the interior structure of subhalos is important at k 100 h Mpc-1. The corresponding effect on the weak-lensing power spectrum due to substructures is up to ~11% at angular scale l 104. Predicting the nonlinear power spectrum to a few percent accuracy for future surveys would therefore require large cosmological simulations that also have exquisite numerical resolution to model accurately the survivals of dark matter subhalos in the tidal fields of their hosts.
Review of Campylobacter spp. in drinking and environmental waters

Consumption of contaminated drinking water is a significant cause of Campylobacter infections. Drinking water contamination is known to result from septic seepage and wastewater intrusion into non-disinfected sources of groundwater and occasionally from cross-connection into drinking water distribution systems. Wastewater effluents, farm animals and wild birds are the primary sources contributing human-infectious Campylobacters in environmental waters, impacting on recreational activities and drinking water sources. Culturing of Campylobacter entails time-consuming steps that often provide qualitative or semi-quantitative results. Viable but non-culturable forms due to environmental stress are not detected, and thus may result in false-negative assessments of Campylobacter risks from drinking and environmental waters. Molecular methods, especially quantitative PCR applications, are therefore important to use in the detection of environmental Campylobacter spp. Processing large volumes of water may be required to reach the desired sensitivity for either culture or molecular detection methods. In the future, applications of novel molecular techniques such as isothermal amplification and high-throughput sequencing applications are awaited to develop and become more affordable and practical in environmental Campylobacter research. The new technologies may change the knowledge on the prevalence and pathogenicity of the different Campylobacter species in the water environment.
Optical Properties of Silicon Clusters in the Presence of Water: A First Principles Theoretical Analysis

We investigate the impact of water on the optical absorption of prototypical silicon clusters. Our clusters contain 5 silicon atoms, tetrahedrally coordinated and passivated with either hydrogen or oxygen. We approach this complex problem by assessing the contributions of three factors: chemical reactivity, thermal equilibration, and dielectric screening. We find that the silanone (Si=O) functional group is not chemically stable in the presence of water and exclude this as a source of significant red shift in absorption in aqueous environments. We perform first principles molecular dynamics simulations of the solvation of a chemically stable, oxygenated silicon cluster with explicit water molecules at 300 K. We find a systematic 0.7 eV red shift in the absorption gap of this cluster, which we attribute to thermally induced fluctuations in the molecular structure. Surprisingly, we find no observable screening impact of the solvent, in contrast with consistent blue shifts observed for similarly sized organic molecules in polar solvents. The predicted red shift is expected to be significantly smaller for larger Si quantum dots produced experimentally, guaranteeing that their vacuum optical properties are preserved even in aqueous environments.
Hopkins Ultraviolet Telescope Observations of Nova Circini 1995 and Nova Aquilae 1995

We observed Nova Cir 1995 and Nova Aql 1995 with the Hopkins Ultraviolet Telescope during the Astro-2 space shuttle mission in 1995 March. The spectra cover the wavelength range from 820 to 1840 A with a spectral resolution of about 3 A, extending the ultraviolet wavelength coverage of novae to the region between Lyα and the Lyman limit for the first time. The Nova Cir spectrum contains many broad carbon, nitrogen, and oxygen emission lines thoughout the HUT wavelength range. We approximate its extinction, and fit absorption by the Lyman and Werner bands of molecular hydrogen to find an H2 column density of log N(H2) = 20.7 cm-2. We calculate electron temperatures and abundances in the nova shell. The abundances are substantially nonsolar. The broad asymmetric line profiles in the Nova Aql spectrum show that this nova has not evolved as quickly as Nova Cir. The Nova Aql spectrum is significantly reddened, with little flux detected below Lyα. A series of three spectra taken over 10 days shows dramatic changes in the ultraviolet line strengths and profiles as the shell evolves.
Quantum memory in warm rubidium vapor with buffer gas

The realization of quantum memory using warm atomic vapor cells is appealing because of their commercial availability and the perceived reduction in experimental complexity. In spite of the ambiguous results reported in the literature, we demonstrate that quantum memory can be implemented in a single cell with buffer gas using the geometry where the write and read beams are nearly copropagating. The emitted Stokes and anti-Stokes photons display cross-correlation values greater than 2, characteristic of quantum states, for delay times up to 4 μs.
Entropy, optimization and counting

We study the problem of computing max-entropy distributions over a discrete set of objects subject to observed marginals. There has been a tremendous amount of interest in such distributions due to their applicability in areas such as statistical physics, economics, biology, information theory, machine learning, combinatorics and algorithms. However, a rigorous and systematic study of how to compute such distributions has been lacking. Since the underlying set of discrete objects can be exponential in the input size, the first question in such a study is if max-entropy distributions have polynomially-sized descriptions. We start by giving a structural result which shows that such succinct descriptions exist under very general conditions. Subsequently, we use techniques from convex programming to give a meta-algorithm that can efficiently (approximately) compute max-entropy distributions provided one can efficiently (approximately) count the underlying discrete set. Thus, we can translate a host of existing counting algorithms, developed in an unrelated context, into algorithms that compute max-entropy distributions. Conversely, we prove that counting oracles are necessary for computing max-entropy distributions: we show how algorithms that compute max-entropy distributions can be converted into counting algorithms.
Post-CMOS processing for high-aspect-ratio integrated silicon microstructures

Presents a new fabrication sequence for integrated-silicon microstructures designed and manufactured in a conventional complementary metal-oxide-semiconductor (CMOS) process. The sequence employs a post-CMOS deep silicon backside etch, which allows fabrication of high aspect ratio (25:1) and flat (greater than 10 mm radius of curvature) MEMS devices with integrated circuitry. A comb-drive resonator, a cantilever beam array and a z-axis accelerometer were fabricated using this process sequence. Electrical isolation of single-crystal silicon was realized by using the undercut of the reactive ion etch (RIE) process. Measured out-of-plane curling across a 120-/spl mu/m-wide 25-/spl mu/m-thick silicon released plate was 0.15 /spl mu/m, which is about ten times smaller than curl of the identical design as a thin-film CMOS microstructure. The z-axis DRIE accelerometer structure is 0.4 mm by 0.5 mm in size and has a 25-/spl mu/m-thick single-crystal silicon proof mass. The measured noise floor is 1 mG//spl radic/Hz, limited by electronic noise. A vertical electrostatic spring "hardening" effect was theoretically predicted and experimentally verified.
The size of a polymer of string-bits: a numerical investigation

Abstract In string-bit models, a string is described as a linear chain (“polymer”) of point-like constituents. We attempt to use string-bit ideas to investigate how the size of the string is affected by string interactions in a non-perturbative context. Lacking adequate methods to deal with the full complications of bit rearrangement interactions, we study instead a simplified analog model with only “direct” potential interactions among the bits. We use the variational principle in an approximate calculation of the mean-square size of a polymer as a function of the number of constituents/bits for various interaction strengths g in three specific models.
AERODYNAMIC DESIGN USING NEURAL NETWORKS

An aerodynamic design procedure that incorporates the advantages of both traditional response surface methodology (RSM) and neural networks is described. The procedure employs a strategy called parameterbased partitioning of the design space and uses a sequence of response surfaces based on both neural networks and polynomial fits to traverse the design space in search of the optimal solution. This approach results in response surfaces that have both the power of neural networks and the economy of low-order polynomials (in terms of number of simulations needed and network training requirements). Such an approach can handle design problems with many more parameters than would be possible using neural networks alone. The design procedure has been applied to the "blind" redesign of a turbine airfoil from a modern jet engine. This redesign involved the use of 15 design variables. The results obtained are closer to the target design than those obtained using an earlier method with only three design variables. The capability of the method in transforming generic shapes, such as simple curved plates, into optimal airfoils is also demonstrated.
Law, Finance, and Economic Growth

This paper examines how the legal environment affects financial development, and then asks how this in turn is linked to long-run economic growth. Financial intermediaries are better developed in countries with legal and regulatory systems that (1) give a high priority to creditors receiving the full present value of their claims on corporations, (2) enforce contracts effectively, and (3) promote comprehensive and accurate financial reporting by corporations. The data also indicate that the exogenous component of financial intermediary development—the component defined by the legal and regulatory environment—is positively associated with economic growth. Journal of Economic Literature Classification Numbers: G21, K12, O16
Design parameters for flow energizers

One of the most significant uses of flow energizers, which are small highly swept strakes mounted immediately above a lifting surface, is in flow control over regions where a lifting surface is joined to another body, such as a fuselage or nacelle. In the presently reported systematic wind tunnel test study of flow energizers, 14 different geometric configurations using a 75-deg sweep flow energizer were tested on a light twin-engine general aviation aircraft model. It is found that cambered flow energizers perform better than their flat counterparts. All but two of the energizer installations developed lower L/D at cruise angles of attack, lower maximum lift coefficients, and lower stall angles of attack than the baseline model.
Orbits of Four Very Massive Binaries in the R136 Cluster

We present radial velocity and photometry for four early-type, massive, double-lined spectroscopic binaries in the R136 cluster. Three of these systems are eclipsing, allowing orbital inclinations to be determined. One of these systems, R136-38 (O3 V + O6 V), has one of the highest masses ever measured for the primary, 57 M☉. Comparison of our masses with those derived from standard evolutionary tracks shows excellent agreement. We also identify five other light variables in the R136 cluster that are worthy of follow-up study.
What do dividend reductions signal

Abstract Dividend reductions have long been considered a “last resort” action for firm managers. Managerial reluctance to reduce dividends emanates from the view that dividend drops signal managerial pessimism regarding future earnings. Contrary to expectations, studies show that earnings rebound significantly following a dividend reduction; yet investors react negatively to the dividend-drop announcement. We present an explanation for the anomalous behavior of earnings and returns around the time of a dividend drop. Our evidence suggests that a reduction in a firm's established dividend coincides with a decrease in the value of the firm's real options. Earnings rebound following the dividend reduction due to the savings that result as the firm allows growth options to expire; however, announcement period returns suggest that investors recognize the lost value associated with the forthcoming expiration of growth options.
A Monte Carlo analysis of the liquid xenon TPC as gamma-ray telescope

Abstract Extensive Monte Carlo modeling of a coded aperture γ-ray telescope based on a high resolution liquid xenon TPC has been performed. Results on efficiency, background reduction capability and source flux sensitivity are presented. We discuss in particular the development of a reconstruction algorithm for events with multiple interaction points. From the energy and spatial information, the kinematics of Compton scattering is used to identify and reduce background events, as well as to improve the detector response in the few MeV region. Assuming a spatial resolution of 1 mm RMS and an energy resolution of 4.5% FWHM at 1 MeV, the algorithm is capable of reducing the background rate expected at balloon altitude by an order of magnitude, thus significantly improving the telescope sensitivity.
Multicasting in ATM networks using MINs

In this paper, we discuss the problem of establishing multicast connections using self-routing multistage interconnection networks (MINs). We examine the issue of multicasting and propose various schemes to accomplish it. Multicasting using recycling of cells has been suggested in the literature recently. We propose a multicast switch architecture that requires a few simple enhancements over a MIN and describe the process of setting up a multicast connection. The size of the routing tables limit the number of copies per cell that can be generated per pass through the network. We assume that no more than two copies per cell can be generated per pass through the routing network, and provide detailed cell-level simulation results for the average delay of a cell. The results show that recycling is a practicable option for multicasting and that the delay does not increase drastically when cells are recycled.
HIV-associated lymphomas.

Intermediate and high-grade non-Hodgkin lymphomas (NHL) with a B-cell phenotype are AIDS-defining illnesses. The incidence of systemic NHL is over 100 times increased, primary central nervous system NHL is over 3000 times increased, and Hodgkin’s disease is approximately 10 times increased in the HIV-infected population. Unusual extranodal presentations of NHL and Hodgkin’s disease are seen in HIV-infected individuals. High-grade histologies are common for both NHL and Hodgkin’s disease in the HIV setting. Treatment approaches may be changing with the advent of highly active antiretroviral therapy, which may allow patients to tolerate more intensive treatment.
Predicting Criminal Recidivism Using "Split Population" Survival Time Models

Abstract In this paper we develop a survival time model in which the probability of eventual failure is less than one and in which both the probability of eventual failure and the timing of failure depend (separately) on individual characteristics. We apply this model to data on the timing of return to prison for a sample of prison releases, and we use it to make predictions of whether or not individuals return to prison. Our predictions are more accurate then previous predictions of criminal recidivism. The model we develop has potential applications in economics; for example, it could be used to model the probability of default and the timing of default on loans.
The Internet, 1995-2000 Access, Civic Involvement, and Social Interaction

This research, which began fielding surveys in 1995 (and thereafter with variation in 1996, 1997, and 2000), was apparently the first to use national random telephone survey methods to track social and community aspects of Internet use and compare users and nonusers. The program has explored the Internet in terms of trends in access, political and civic involvement, and social interaction. The authors uncovered serendipitously what they call the Internet dropout phenomenon. The findings have found a decline in some aspects of the digital divide, especially once awareness has been achieved and when the year of adoption is considered. Contrary to the pessimistic assertions of many, no loss was discerned in terms of the indicators of political or community involvement. The findings support a more positive interpretation of the Internet's impact, at least in terms of interpersonal communication, where Internet use was associated with greater levels of telephone use (although not of correspondence by mail) and...
Tandem Enyne Metathesis and Claisen Rearrangement: A Versatile Approach to Conjugated Dienes of Variable Substitution Patterns

To extend the versatility of the ruthenium carbene-promoted enyne metathesis, it was combined with an Ireland ester enolate Claisen rearrangement. This reaction sequence provided conjugated dienes of higher substitution pattern than that obtained through a cross-enyne metathesis alone. The Ireland−Claisen was conducted across both acyclic and cyclic dienes produced from cross-metathesis and methylene-free enyne metathesis, respectively. In the case of cyclodienes, the Ireland−Claisen rearrangement produced s-trans locked dienes which underwent mode-selective ene reaction. The tandem, sequential use of the Ireland−Claisen rearrangement also proved suitable for chirality transfer originating from chiral propargylic alcohols. Last, the tandem metathesis/Ireland−Claisen was utilized to access 4-substituted-3,5-cyclohexadiene diol derivatives, which are valuable chiral intermediates for natural product synthesis. The combination of this pericyclic reaction with a catalytic metathesis reaction extends the versa...
Aspects of high resolution imaging with a scanning ion microprobe

Abstract High lateral resolution imaging (≈ 20 nm) secondary ion mass spectrometry (SIMS) can be achieved with liquid metal ion sources (LMIS). The use of scanning ion microprobes to explore the sensitivity and limitations of SIMS is discussed using examples from metallurgical and biological applications.
Formation of Multinary Intermetallics from Reduction of Perovskites by Aluminum Flux: M3Au6+xAl26Ti (M = Ca, Sr, Yb), a Stuffed Variant of the BaHg11 Type

New intermetallic phases were synthesized by reacting oxidic perovskites and gold metal in aluminum flux. The combination of MTiO3 (M = Ca, Sr, Ba) and Au metal in excess molten aluminum produces quaternary compounds M3Au6+xAl26Ti with a stuffed BaHg11 structure type. An analogue with M = Yb was also synthesized; it shows mixed valent behavior.
Multi-reference evaluation of uncertainty in earth orientation parameter measurements

Uncertainties in polar motion and length-of-day measurements are evaluated empirically using several data series from the space-geodetic techniques of the global positioning system (GPS), satellite laser ranging (SLR), and very long baseline interferometry (VLBI) during 1997-2002. In the evaluation procedure employed here, known as the three-corner hat (TCH) technique, the signal common to each series is eliminated by forming pair-wise differences between the series, thus requiring no assumed values for the 'truth' signal. From the variances of the differenced series, the uncertainty of each series can be recovered when reasonable assumptions are made about the correlations between the series. In order to form the pair-wise differences, the series data must be given at the same epoch. All measurement data sets studied here were sampled at noon (UTC); except for the VLBI series, whose data are interpolated to noon and whose UT1 values are also numerically differentiated to obtain LOD. The numerical error introduced to the VLBI values by the interpolation and differentiation is shown to be comparable in magnitude to the values determined by the TCH method for the uncertainties of the VLBI series. The TCH estimates for the VLBI series are corrupted by such numerical errors mostly as a result of the relatively large data intervals. Of the remaining data sets studied here, it is found that the IGS Final combined series has the smallest polar motion and length-of-day uncertainties.
Eliciting information from multiple experts

Abstract A decision maker DM has to elicit information from informed experts regarding the desirability of a certain action. The experts share similar preferences, which differ significantly from those of DM, and they possess different pieces of information. The question is how much information DM can elicit, despite the difference in interests. The focus is on how DM can take advantage of the multiplicity of experts. For the case in which DM cannot commit to a mechanism, the main observation is that allowing partial communication among the experts might result in revelation of more information than either full communication or no communication. In the case in which DM can commit to a mechanism the maximum inducement for revelation is attained by mechanisms that are non-monotonic in the information. The analysis makes repeated use of the idea that experts understand that their reports matter only when they are pivotal.
Synthesis and crystal structures of yttrium sulfates Y(OH)(SO4), Y(SO4)F, YNi(OH)3(SO4)-II and Y2Cu(OH)3(SO4)2F·H2O

Abstract Y(OH)(SO 4 ), Y(SO 4 )F, YNi(OH) 3 (SO 4 )-II and Y 2 Cu(OH) 3 (SO 4 ) 2 F·H 2 O are obtained from hydrothermal reactions at 380°C under a pressure of 210 MPa. Their crystal structures were refined from single-crystal X-ray diffraction data. The four compounds have the following space groups and unit cells: Y(OH)(SO 4 ), P 2 1 / n , a =7.9498(6), b =10.9530(9), c =8.1447(6) A, β =93.764(1)°; Y(SO 4 )F, Pnma , a =8.3128(9), b =6.9255(7), c =6.3905(7) A; YNi(OH) 3 (SO 4 )-II, Pnma , a =6.9695(8), b =7.2615(8), c =10.292(1) A; Y 2 Cu(OH) 3 (SO 4 ) 2 F·H 2 O, P 2 1 / n , a =11.6889(7), b =6.8660(4), c =12.5280(8) A, β =97.092(1)°. The coordination environments of the yttrium atoms in the four structures vary from highly irregular 6+2, 6+3, 7+1 coordination polyhedra to relatively regular dodecahedra.
Neutrino gravitational redshift and the electron fraction above nascent neutron stars

Abstract Neutrinos emitted from near the surface of the hot proto-neutron star produced by a supernova explosion may be subject to significant gravitational redshift at late times. Electron antineutrinos ( ν e ) decouple deeper in the gravitational potential well of the neutron star than do the electron neutrinos (νe), so that the ν e experience a larger redshift effect than do the νe. We show how this differential redshift can increase the electron fraction Ye in the neutrino-heated ejecta from the neutron star. Any r-process nucleosynthesis originating in the neutrino-heated ejecta would require a low Ye, implying that the differential redshift effect cannot be too large. In turn, this effect may allow nucleosynthesis to probe the nuclear equation of state parameters which set the neutron star radius and surface density scale height at times of order tpb ≈ 10 s to 25 s after core bounce.
Producing 13C NMR, Infrared Absorption, and Electron Ionization Mass Spectrometric Data Models of the Monodechlorination of Chlorobenzenes, Chlorophenols, and Chloroanilines

We have developed four spectroscopic data−activity relationship (SDAR) models of monodechlorination of 32 chlorinated benzene compounds in anaerobic estuarine sediment. The SDAR models were based on combinations of 13C nuclear magnetic resonance (NMR), infrared absorption (IR), and electron ionization mass spectrometric (EI MS) data. The SDAR models segregated the 32 compounds into 17 readily monodechlorinated compounds and 15 not readily monodechlorinated compounds. The SDAR model based on 13C NMR, IR, and EI MS data gave a leave-one-out cross-validation of 93.8%. The SDAR model based on a composite of 13C NMR and IR data gave a leave-one-out cross-validation of 90.6%. The SDAR model based on a composite of IR and EI MS data gave a leave-one-out cross-validation of 84.4%. The SDAR model based on a composite of 13C NMR and EI MS data gave a leave-one-out cross-validation of 84.4%. These reliable SDAR models provide a rapid and simple way to predict whether a chlorinated benzene compound will readily go th...
An axiomatic theory of political representation

We discuss the theory of voting rules which are immune to gerrymandering. Our approach is axiomatic. We show that any rule that is unanimous, anonymous, and representative consistent must decide a social alternative as a function of the proportions of agents voting for each alternative, and must either be independent of this proportion, or be in one-to-one correspondence with the proportions. In an extended model in which voters can vote over elements of the unit interval, we introduce and characterize the quasi-proportional rules based on unanimity, anonymity, representative consistency, strict monotonicity, and continuity. We show that we can always (pointwise) approximate a single-member district quota rule with a quasi-proportional rule. We also establish that upon weakening strict monotonicity, the generalized target rules emerge.
Etiology, triggers and neurochemical circuits associated with unexpected, expected, and laboratory-induced panic attacks

Panic disorder (PD) is a severe anxiety disorder that is characterized by recurrent panic attacks (PA), which can be unexpected (uPA, i.e., no clear identifiable trigger) or expected (ePA). Panic typically involves an abrupt feeling of catastrophic fear or distress accompanied by physiological symptoms such as palpitations, racing heart, thermal sensations, and sweating. Recurrent uPA and ePA can also lead to agoraphobia, where subjects with PD avoid situations that were associated with PA. Here we will review recent developments in our understanding of PD, which includes discussions on: symptoms and signs associated with uPA and ePAs; Diagnosis of PD and the new DSM-V; biological etiology such as heritability and gene×environment and gene×hormonal development interactions; comparisons between laboratory and naturally occurring uPAs and ePAs; neurochemical systems that are associated with clinical PAs (e.g. gene associations; targets for triggering or treating PAs), adaptive fear and panic response concepts in the context of new NIH RDoc approach; and finally strengths and weaknesses of translational animal models of adaptive and pathological panic states.