cssi/SciSciGPT-SciSciNet huggingface dataset:
The Free Electron Laser and Its Possible Developments

The two experiments(1, 2) made at Stanford University in 1975 and 1977, which have shown that it is possible to operate a free-electron laser, have been a turning point in the research on stimulated electromagnetic radiation by relativistic electrons. The interest in this subject and the number of papers discussing it have been increasing very rapidly since the results of these experiments have been known. As a result of all this work we have now a good understanding of the basic principles underlying a free-electron laser and of the feasibility and characteristics of this device.
Under what conditions may social contracts arise? Evidence from the Hanseatic League

Social contractarians commonly take social contracts to be solely hypothetical and refrain from elaborating on the factors that influence the feasibility of the formation of social contracts. In contrast, this paper aims at providing a discussion of the conditions affecting the feasibility of social contracts. I argue that the more aligned the preferences of group members for public goods are, the more the individuals share similar social norms, and the smaller the group is the more feasible a genuine social contract becomes. I provide evidence in support of my contention from the medieval Hanseatic League. At the Hanseatic Kontor in Novgorod, one of the four major trading posts of the Hanseatic League in cities outside of Germany, German merchants agreed to live under the rule of a constitution that gave rise to a political authority for the Kontor society.
Amenability, tubularity, and embeddings into \mathcal{R}^{\omega}

Suppose M is a tracial von Neumann algebra embeddable into \(\mathcal{R}^{\omega}\) (the ultraproduct of the hyperfinite II1-factor) and X is an n-tuple of selfadjoint generators for M. Denote by Γ(X; m, k, γ) the microstate space of X of order (m, k ,γ). We say that X is tubular if for any e > 0 there exist \(m \in \mathbb{N}\) and γ > 0 such that if \((x_{1},\ldots, x_{n}), (y_{1}, \ldots, y_{n}) \in \Gamma(X;m,k,\gamma),\) then there exists a k × k unitary u satisfying \(|ux_iu^* - y_i|_2 < \epsilon\) for each 1 ≤ i ≤ n. We show that the following conditions are equivalent: M is amenable (i.e., injective). X is tubular. Any two embeddings of M into \(\mathcal{R}^{\omega}\) are conjugate by a unitary \(u \in \mathcal {R}^{\omega}\).
Vision and the atmosphere

Current vision systems are designed to perform in clear weather. Needless to say, in any outdoor application, there is no escape from “bad” weather. Ultimately, computer vision systems must include mechanisms that enable them to function (even if somewhat less reliably) in the presence of haze, fog, rain, hail and snow. We begin by studying the visual manifestations of different weather conditions. For this, we draw on what is already known about atmospheric optics, and identify effects caused by bad weather that can be turned to our advantage. Since the atmosphere modulates the information carried from a scene point to the observer, it can be viewed as a mechanism of visual information coding. We exploit two fundamental scattering models and develop methods for recovering pertinent scene properties, such as three-dimensional structure, from one or two images taken under poor weather conditions. Next, we model the chromatic effects of the atmospheric scattering and verify it for fog and haze. Based on this chromatic model we derive several geometric constraints on scene color changes caused by varying atmospheric conditions. Finally, using these constraints we develop algorithms for computing fog or haze color, depth segmentation, extracting three-dimensional structure, and recovering “clear day” scene colors, from two or more images taken under different but unknown weather conditions.
Variable Structure Adaptive Control of Wing-Rock Motion of Slender Delta Wings

Based on the variable structure model reference adaptive control (VS-MRAC) theory, a new control system for the control of wing-rock motion of slender delta wings, using only roll angle measurement, is designed. For the derivation of the control law, it is assumed that the aerodynamic parameters and the structure of the nonlinear aerodynamic nonlinear functions in the model are unknown. Moreover, it is assumed that disturbance input is present in the system. It is shown that in the closed-loop system including the VS-MRAC system designed using bounds on uncertain functions, the roll angle tracks given reference trajectory and the wing-rock motion is suppressed. Digital simulation results show that the closed-loop system has good transient behavior and robustness to the uncertainties and disturbance input.
Transthoracic fine-needle aspiration biopsy of pulmonary spindle cell and mesenchymal lesions: a study of 61 cases.

BACKGROUND Spindle cell and mesenchymal lesions of the lung encompass a wide variety of benign and malignant conditions. However, to the authors' knowledge, because of their rarity, few reports concerning their cytologic findings are available in the literature. The current review emphasizes the cytomorphologic features, differential diagnosis, and potential pitfalls associated with these lesions. METHODS Seven hundred seventy-nine percutaneous lung fine-needle aspiration (FNA) specimens were retrieved from the authors' cytopathology files over a period of 5 years. Sixty-one cases (7.8%) in which a spindle cell component was the dominant or key feature were identified. The authors reviewed the cytologic smears, immunocytochemical studies, and corresponding surgical material and clinical information. RESULTS Of these 61 aspirates, 33 (54%) were reactive processes (31 granulomas, 1 organizing pneumonia, and 1 inflammatory pseudotumor). Five cases (0.8%) were benign neoplasms (2 hamartomas, 2 solitary fibrous tumors, and 1 schwannoma). Twenty-three cases (38%) were malignant neoplasms (8 cases were primary tumors [including 5 carcinomas with spindle cell or sarcomatoid features, 1 spindle cell carcinoid tumor, 1 leiomyosarcoma, and 1 synovial sarcoma] and 15 cases were secondary tumors [including 9 melanomas, 2 leiomyosarcomas, 1 malignant fibrous histiocytoma, 1 meningioma, 1 sarcomatoid renal cell carcinoma, and 1 uterine malignant mixed mullerian tumor]). A specific diagnosis was rendered in 52 cases (85%). No false-positive cases were encountered but there was one false-negative case. One patient who was diagnosed with granulomatous inflammation on FNA was found to have nonsmall cell lung carcinoma on subsequent transbronchial biopsy. No malignant cells were identified in the smears on review. The FNA from the organizing pneumonia was interpreted as a solitary fibrous tumor whereas the inflammatory pseudotumor was diagnosed as granulomatous inflammation. The FNA from one pulmonary hamartoma initially was considered to be nondiagnostic. One solitary fibrous tumor and the schwannoma were diagnosed as smooth muscle tumor and spindle cell tumor, not otherwise specified, respectively. Among the malignant tumors, the primary synovial sarcoma and one of the metastatic malignant melanomas initially were interpreted as primitive neuroectodermal tumor/Ewing sarcoma and poorly differentiated carcinoma, respectively. CONCLUSIONS Spindle cell lesions of the lung rarely are encountered on transthoracic lung FNA and are comprised of a wide variety of benign and malignant entities. By correlating clinical and radiologic data, cytologic findings, and ancillary studies, a high diagnostic accuracy rate can be achieved with FNA. Cancer (Cancer Cytopathol) 2001;93:187–198. © 2001 American Cancer Society.
Efficacy of fixed filtration for rapid kVp-switching dual energy x-ray systems: experimental verification

The dose efficiency of dual energy imaging can be improved if the spectra are filtered to increase spectral separation. Our preliminary simulations showed that a fixed Gd filter can be efficacious in rapid kVp-switching systems. We conducted physical experiments on a table top x-ray system to verify the performance improvement before moving forward to a real CT scanner. We chose a commercial Gd 2 O 2 S screen as our filter and used an acrylic-copper step wedge phantom. Data were collected at 70 and 125 kVp, with and without the filter. The tube current was adjusted to make the exposure rate with and without the filter to be roughly the same. The data were decomposed into basis material images and the variance of the decomposition was measured for each acrylic-copper thickness pair. Simulations were done with the same experimental settings for comparison and validation. The experiments verified that a Gd filter can reduce the variance at fixed dose. The variance reduction is monotonically stronger as the object becomes more attenuating. This study demonstrates the potential of fixed Gd filtration to improve the dose efficiency and material decomposition precision for rapid kVp-switching dual energy systems.
Low-Power, High-Performance Architecture of the PWRficient Processor Family

The dual-core PA6T-1682M system on chip (SoC) is the first design in the PWRficient family of high-performance, low-power processor designs that target server-class performance with low power consumption. the heart of the PA6T-1682M is the PA6T core, which implements the 64-bit IBM power architecture. The SoC implements extensive features that support embedded and mobile low-power applications.
Balanced Dissipative Controllers for Flexible Structures

A balanced approach to shaping the closed-loop properties of the dissipative controllers for flexible structures is presented. In the balanced representation the properties of flexible structures are introduced, and a simple method of designing of the dissipative controllers is obtained. It correlates the controller gains with the closed-loop pole locations. The examples illustrate the accuracy of the design method. (Author)
Do bad report cards have consequences? Impacts of publicly reported provider quality information on the CABG market in Pennsylvania.

Abstract Since 1992, the Pennsylvania Health Care Cost Containment Council (PHC4) has published cardiac care report cards for coronary artery bypass graft (CABG) surgery providers. We examine the impact of CABG report cards on a provider's aggregate volume and volume by patient severity and then employ a mixed logit model to investigate the matching between patients and providers. We find a reduction in volume of poor performing and unrated surgeons’ volume but no effect on more highly rated surgeons or hospitals of any rating. We also find that the probability that patients, regardless of severity of illness, receive CABG surgery from low-performing surgeons is significantly lower.
Space charge effects in a gyrotron employing a solid electron beam

The influence of space charge forces on the performance of a single cacity gyrotron oscillator which uses a solid electron beam was investigated. It was found that space charge effects cause a large efficiency degradation as the beam current is increased, if the other experimental parameters are unchanged. A small increase in the magnetic field, however, can restore the efficiency to higher values.
IN VITRO DEMONSTRATION OF HUMORAL AND CELL-BOUND IMMUNITY AGAINST COMMON SPECIFIC TRANSPLANTATION ANTIGEN(S) OF ADENOVIRUS 12-INDUCED MOUSE AND HAMSTER TUMORS

A colony inhibition (CI) technique was used to demonstrate in vitro tumor-specific antigenicity common for neoplasms induced by the adenovirus type 12. Immunization of mice against syngeneic mouse adeno 12 tumor cells evoked immunity demonstrable against other adeno 12 neoplasms of mice and of hamster as well. The immunity was detected as antibody activity in the sera of specifically immunized mice and as a similar activity of the lymph node cells of these animals. The finding in transplantation experiments that infection with adenovirus types 12 and 7 induces an isograft immunity against adeno 12 tumors was confirmed by CI tests on the sera of virus-infected mice. The probable identity of the antigen detected by the CI technique and the tumor-specific transplantation antigen is discussed.
Relationship Between Changes in Serum Levels of Keratin 18 and Changes in Liver Histology in Children and Adults With Nonalcoholic Fatty Liver Disease

Background & Aims Cross-sectional studies have associated serum levels of the keratin 18 (K18) fragment with histologic features of liver in individuals with nonalcoholic fatty liver disease (NAFLD). We investigated the relationship between changes in serum levels of K18 and changes in liver histology in adults and children with NAFLD. Methods We measured levels of K18 in stored serum samples collected at baseline and various time points from 231 adults with nonalcoholic steatohepatitis and 152 children with NAFLD who participated in 2 separate prospective randomized clinical trials. Liver biopsy specimens collected at baseline and week 96 were reviewed centrally. Results There were greater decreases in serum levels of K18 in adults with histologic improvement at week 96 than in those without histologic improvement at week 16 (decrease, 193 ± 293 vs 139 ± 467 U/L; P P P P = .005) and week 96 (decrease, 206 ± 432 vs 2 ± 474 U/L; P P = .34) or children (AUROC, 0.72; 95% CI, 0.63–0.81; vs AUROC, 0.79; 95% CI, 0.70–0.87; P = .42). Conclusions Decreases in serum levels of K18 are associated strongly with improved liver histologies in adults or children with NAFLD. However, reductions in K18 do not perform better than those in alanine aminotransferase level in identifying histologic changes in NAFLD.
Molecular multiphoton ionization spectroscopy

Multiphoton ionization (MPI) spectroscopy is rapidly evolving into a valuable adjunct to VUV spectroscopy for the study of the highly excited states of molecules. The technique is described, and several examples are given of its applications. Studies of the 3pz Rydberg states of the methylbenzenes and of the 1B2u state of benzene show that state assignments can be made and new multiphoton structure seen that is not available in one-photon spectra. MPI of benzene in a supersonic jet demonstrates dramatic resolution improvement and shows that natural linewidth information can be gained for large molecules. Collisional effects in MPI spectra are briefly discussed with reference to Xe and to laser enhanced collisional broadening of nitric oxide in the supersonic beam.
Nitrogen and harvest effects on soil properties under rainfed switchgrass and no-till corn over 9 years: implications for soil quality

Nitrogen fertilizer and harvest management will alter soils under bioenergy crop production and the long-term effects of harvest timing and residue removal remain relatively unknown. Compared to no-tilled corn (NT-C, Zea mays L.), switchgrass (Panicum virgatum L.) is predicted to improve soil properties [i.e. soil organic C (SOC), soil microbial biomass (SMB-C), and soil aggregation] due to its perennial nature and deep-rooted growth form, but few explicit field comparisons exist. We assessed soil properties over 9 years for a rainfed study of N fertilizer rate (0, 60, 120, and 180 kg N ha 1 ) and harvest management on switchgrass (harvested in August and postfrost) and NT-C (with and without 50% stover removal) in eastern NE. We measured SOC, aggregate stability, SMB-C, bulk density (BD), pH, P and K in the top 0–30 cm. Both NT-C and switchgrass increased SMB-C, SOC content, and aggregate stability over the 9 years, reflecting improvement from previous conventional management. However, the soils under switchgrass had double the percent aggregate stability, 1.3 times more microbial biomass, and a 5–8% decrease in bulk density in the 0–5 and 5–10 cm depths compared to NT-C. After 9 years, cumulative decrease in available P was significantly greater beneath NT-C (24.0 kg P ha 1 ) compared to switchgrass (5.4 kg P ha 1 ). When all measured soil parameters were included in the Soil Management Assessment Framework (SMAF), switchgrass improved soil quality index over time (DSQI) in all depths. NT-C without residue removal did not affect DSQI, but 50% residue removal decreased DSQI (0–30 cm) due to reduced aggregate stability and SMB-C. Even with best-management practices such as NT, corn stover removal will have to be carefully managed to prevent soil degradation. Long-term N and harvest management studies that include biological, chemical, and physical soil measurements are necessary to accurately assess bioenergy impacts on soils.
Fluidized bed viscosity measurements in reduced gravity

Abstract Fluidized bed viscosity was studied experimentally in a series of reduced gravity parabolic flights aboard NASA's KC-1335 aircraft. Silica sands of two different size distributions were fluidized by air. The experimental setup incorporated instrumentation to measure the air flow rate, the pressure drop and the apparent viscosity of the fluidized sand at a wide range of the shear rate. The fluidization chamber had transparent walls to allow visualization of the structure changes involved in fluidization in reduced gravity. Experiments were performed over a broad range of gravitational acceleration including microgravity and double gravity conditions. The results of the flight and ground experiment reveal significant differences in overall void fraction and hence in the apparent viscosity of fluidized sand under microgravity as compared to single gravity conditions.
Numerical Simulations of Resonant Heat Transfer Augmentation at Low Reynolds Numbers

The effect of flow rate modulation on low Reynolds number heat transfer enhancement in a transversely grooved passage was numerically simulated using a two-dimensional spectral element technique. Simulations were performed at subcritical Reynolds numbers of Rem = 133 and 267, with 20% and 40% flow rate oscillations. The net pumping power required to modulate the flow was minimized as the forcing frequency approached the predicted natural frequency. However, mixing and heat transfer levels both increased as the natural frequency was approached. Oscillatory forcing in a grooved passage requires two orders of magnitude less pumping power than flat passage systems for the same heat transfer level. Hydrodynamic resonance appears to be an effective method of increasing heat transfer in low Reynolds number systems where pumping power is at a premium, such as micro heat transfer applications.
Average case analysis of dynamic geometric optimization

Abstract We maintain the maximum spanning tree of a planar point set, as points are inserted or deleted, in O(log3 n) expected time per update in Mulmuley's average-case model of dynamic geometric computation. We use as subroutines dynamic algorithms for two other geometric graphs: the farthest neighbor forest and the rotating caliper graph related to an algorithm for static computation of point set widths and diameters. We maintain the former graph in expected time O(log2 n) per update and the latter in expected time O(log n) per update. We also use the rotating caliper graph to maintain the diameter, width, and minimum enclosing rectangle of a point set in expected time O(log n) per update. A subproblem uses a technique for average-case orthogonal range search that may also be of interest.
Auditory responses to the envelopes of pseudorandom noise stimuli in humans.

Abstract Averaged scalp potentials evoked by continuous pseudorandom noise can be cross-correlated with the evoking stimulus, yielding a cross-correlation function (CCF) which reflects neural phase-locking and is quite sensitive for low-frequency stimulus components [M.J. Wilson and R.A. Dobie (1987) Electroencephalogr. Clin. Neurophysiol. 66, 529–538]. However, for higher frequency signals, replicable CCFs can only be obtained at moderate to high intensities. Since auditory neurons also respond to envelopes of complex sounds, even for high-frequency carriers, we compared scalp responses evoked by band-limited complex sounds to the envelopes of these sounds; the resultant envelope cross-correlation functions (ECCFs) contained replicable response components primarily below 1000 Hz, regardless of the evoking stimulus spectrum. ECCF thresholds for three octave-band stimuli (830–1562, 1611–3125, and 3174–6201 Hz) were more sensitive than CCF thresholds ( P = 0.006), averaging 35 dB spectrum level for 10 normal subjects. When stimuli with only odd harmonics were used, replicable odd-component scalp responses were seen only in the spectral range of the stimuli, while even-component responses (presumably to stimulus envelope) were seen only in low-passed scalp responses.
Deterministic and Randomized Algorithms for Distributed On-Line Task Assignment and Load Balancing without Load Status Information

We find two interesting thresholds for the number of tasks generated under a new model of distributed on-line task assignment and load balancing environment, in which tasks are assigned without any information of current load status and load balancing is achieved together with task assignment. It is shown that balanced load distribution can be obtained deterministically when the number of tasks exceeds the first threshold. Otherwise, a simple randomized strategy can achieve balanced load distribution with high probability if the number of tasks exceeds the second threshold.
Continuous and discrete Fourier frames for fractal measures

Motivated by the existence problem of Fourier frames on fractal measures, we introduce Bessel and frame measures for a given finite measure on R d , as extensions of the notions of Bessel and frame spectra that correspond to bases of exponential functions. Not every finite compactly supported Borel measure admits frame measures. We present a general way of constructing Bessel/frame measures for a given measure. The idea is that if a convolution of two measures admits a Bessel measure then one can use the Fourier transform of one of the measures in the convolution as a weight for the Bessel measure to obtain a Bessel measure for the other measure in the convolution. The same is true for frame measures, but with certain restrictions. We investigate some general properties of frame measures and their Beurling dimensions. In particular we show that the Beurling dimension is invariant under convolution (with a probability measure) and under a certain type of discretization. Moreover, if a measure admits a frame measure then it admits an atomic one, and hence a weighted Fourier frame. We also construct some examples of frame measures for self-similar measures.
The varieties of loops of Bol-Moufang type

A loop identity is of Bol-Moufang type if two of its three variables occur once on each side, the third variable occurs twice on each side, and the order in which the variables appear on both sides is the same, viz. ((xy)x)z = x(y(xz)). Loop varieties defined by one identity of Bol-Moufang type include groups, Bol loops, Moufang loops and C-loops. We show that there are exactly 14 such varieties, and determine all inclusions between them, providing all necessary counterexamples, too. This extends and completes the programme of Fenyves [Fe69].
Generalizing Glycosylation: Synthesis of the Blood Group Antigens Lea, Leb, and Lex Using a Standard Set of Reaction Conditions

Because there are no general reaction conditions for any glycosylation method, biologically interesting oligosaccharides can only be made in a small number of laboratories in the world. To make carbohydrate synthesis accessible to nonspecialists, it is critical to have glycosylation methods that will work in a wide range of cases under a single set of conditions. The Lewis blood group antigens have attracted the attention of numerous synthetic carbohydrate groups because of their structural complexity. Although they have been synthesized many times, they have never been made using a single glycosylation method under one set of reaction conditions. In this paper, we show that the sulfoxide glycosylation method can be used to form all of the glycosidic linkages in the Lewis blood group antigens Lea (1), Leb (2), and Lex (3) stereoselectively under a uniform set of reaction conditions. This work highlights the flexibility of the sulfoxide method and demonstrates its utility for constructing families of relat...
Seeing-Is-Believing: using camera phones for human-verifiable authentication

Current mechanisms for authenticating communication between devices that share no prior context are inconvenient for ordinary users, without the assistance of a trusted authority. We present and analyse Seeing-Is-Believing (SiB), a system that utilises 2D barcodes and camera-phones to implement a visual channel for authentication and demonstrative identification of devices. We apply this visual channel to several problems in computer security, including authenticated key exchange between devices that share no prior context, establishment of the identity of a TCG-compliant computing platform, and secure device configuration in the context of a smart home.
Quantitative comparison of biological dressings.

Abstract A new animal model has been developed to compare simultaneously the effect of various “biological” dressings on the bacterial count in contaminated wounds. Using this model, amniotic membranes proved superior to allograft and xenograft skin in decreasing the bacterial counts in wounds contaminated with Pseudomonas aeruginosa .
Resonant emergence of global and local spatiotemporal order in a nonlinear field model

We investigate the nonequilibrium evolution of a scalar field in (2+1) dimensions. The field is set in a double-well potential in contact (open) or not (closed) with a heat bath. For closed systems, we observe the synchronized emergence of coherent spatiotemporal configurations, identified with oscillons. This initial global ordering degenerates into localized order until all oscillons disappear. We show that the synchronization is driven by resonant parametric oscillations of the field's zero mode and that local ordering is only possible outside equipartition. None of these orderings occur for open systems.
Defining the Intervention and the Target Population

In the field of drug prevention, there is lack of clarity in the definition of prevention goals and targets. Prevention goals range from reducing precursors of later drug experimentation, to postponing onset of gateway substances (cigarettes, alcohol), to reducing risk of permanent harm from drug use, to achievement of abstinence. Further, differing criteria are used to define who is at risk and thus should be the target of intervention. The article discusses these issues and recommends a framework for achieving definitional clarity.
Flexible Bearing Supports, Using Experimental Data

A laboratory rotor, representing a scaled-down model of a three-stage compressor supported by fluid film bearings on anisotropic flexible supports was analyzed. The support characteristics were measured at the bearing locations by exciting the bearing housings with electromechanical shakers and measuring the acceleration. Direct, cross-coupled, and cross-talk accelerance between supports were measured. Unbalance response and stability analyses of the rotor were performed using polynomial transfer functions extracted from the measured accelarance data. The predicted critical speeds and instability threshold agree with measured data. Predictions using other support models are included to show the effectiveness of this method.
LAW OF ADDITION IN RANDOM MATRIX THEORY

Abstract We discuss the problem of adding random matrices, which enables us to study Hamiltonians consisting of a deterministic term plus a random term. Using a diagrammatic approach and introducing the concept of “gluon connectedness”, we calculate the density of energy levels for a wide class of probability distributions governing the random term, thus generalizing a result obtained recently by Brezin, Hikami and Zee. The method used here may be applied to a broad class of problems involving random matrices.
Faint BVRI Photometric Sequences in Selected Fields

The results from work done to extend the Johnson-Cousins BVRI photometric standard sequence to faint levels of V ~ 21 mag in compact fields is presented. Such calibration and extension of sequences is necessary to fill a calibration gap if reliable photometry from modest aperture telescopes in space (e.g., the Hubble Space Telescope) or terrestrial telescopes with apertures exceeding 4 m is to be done. Sequences like the ones presented here, which cover a large range in brightness as well as color, will allow photometric calibration to be done efficiently and will also make such work less prone to systematic sources of error. Photometry of stars in approximately 10' × 10' fields around three globular clusters (NGC 2419, Pal 4, and Pal 14) are presented from data acquired over several photometric nights. In each field, several stars are measured in B, V, R, and I passbands, with standard errors in the mean less than 0.015 mag from random errors, to levels fainter than V = 21 mag. It is shown that when tying to the Landolt standards on the Johnson-Cousins system, standard errors in the mean from systematic errors are typically well below 0.01 mag in all four bands (except for B in NGC 2419 and R in Pal 4), thus justifying the claim that these fields have been correctly calibrated. The primary context for the work presented here is that parts of these fields were observed repeatedly by the Wide Field Planetary Camera 2 (WFPC2) on the HST, and thus these newly calibrated sequences can be used to retroactively calibrate WFPC2 at various times over its operating life. In the past, WFPC2 data have had typical photometric zero-point uncertainties of a few hundredths of a magnitude, largely due to a lack of suitable standard stars. The sequences presented here have standard errors at the 0.01 mag level. They agree at the 0.02 mag level with other extant calibrations of the targets presented here, except in the I band, where there are color-dependent deviations of up to 0.05 mag versus one other photometric sequence. There is no clear resolution of this difference: we present as much verification of the sequences presented here as possible. We argue that a very likely reason for such discrepancies is differences in the filter bandpass.
Venom immunotherapy reduces large local reactions to insect stings

Background Large local reactions to insect stings cause significant morbidity and impair quality of life. Venom immunotherapy is not recommended because of a low risk for future systemic reaction and unproven efficacy in preventing large local reactions. Objective To determine the feasibility of performing a controlled trial to examine the efficacy of venom immunotherapy in reducing the size and duration of large local reactions. Methods Sting challenge in 41 patients with previous large local reactions and positive venom skin tests caused large local reactions 16 cm or larger in 34 patients, and 29 consented to treatment. Venom immunotherapy was initiated in 19, and 10 were untreated controls. Sting challenge was repeated after 7 to 11 weeks (control patients then began venom immunotherapy), and annually for as long as 4 years. Results After 7 to 11 weeks of treatment, the size and duration of large local reactions decreased 42% and 53%, respectively, in treated patients and 18% in controls ( P Conclusions Venom immunotherapy significantly reduced the size and duration of the large local reactions, and the efficacy improved over a period of 2 to 4 years of treatment. Further studies are needed to establish the safety and efficacy of venom immunotherapy for large local reactions, the optimal duration of treatment, and the mechanism for the differences in degree and rate of clinical response compared with venom immunotherapy in systemic reactors.
An integral equation in conformal geometry

Motivated by Carleman's proof of the isoperimetric inequality in the plane, we study the problem of finding a metric with zero scalar curvature maximizing the isoperimetric ratio among all zero scalar curvature metrics in a fixed conformal class on a compact manifold with boundary. We derive a criterion for the existence and make a related conjecture.
Profile imaging of reconstructed polar and non-polar surfaces of ZnO

Abstract The atomic scale surface structures of ZnO ( 0 1 1 ¯ 0 ) non-polar as well as ( 0 1 ¯ 1 1 ) and ±(0 0 0 1) polar surfaces have been directly imaged by high-resolution transmission electron microscopy (HRTEM). The observations were made on clean surfaces created by irradiating a single ZnO nanobelt using 400 keV electron beam in TEM, under which ZnO dots were grown epitaxially and in situ on the surface of the nanobelt. A technique is demonstrated for directly distinguishing the surface polarity of the ±(0 0 0 1) polar surfaces. For the ( 0 1 1 ¯ 0 ) non-polar surface, HRTEM images and simulation results indicate that the Zn ions in the first and second layer suffer from inward and outward relaxation, respectively; the oxygen ions in the first and second layer prefer shifting to vicinal Zn ions to shorten the bonding distance. For the oxygen-terminated ( 0 1 ¯ 1 1 ) polar surface, the oxygen ions at the outmost top layer were directly imaged. a × 2 reconstruction has also been observed at the ( 0 1 ¯ 1 1 ) surface, and its atomic structure has been proposed based on image simulation. Oxygen-terminated ( 0 0 0 1 ¯ ) polar surface is flat and shows no detectable reconstruction. For the Zn-terminated (0 0 0 1) polar surface, HRTEM may indicate the existence of Zn vacancies and a possibly c-axis, random outward displacement of the top Zn ions. Our data tend to support the mechanism of removal of surface atoms for maintaining the stability of (0 0 0 1) polar surfaces.
The genetic basis of spondyloarthritis

Modern technological innovations have advanced our understanding of the genetic basis of spondyloarthritis. In ankylosing spondylitis (AS), where the major histocompatibility complex (MHC) accounts for nearly half of the predisposition, most comes from HLA-B27, for which 65 subtypes are now recognised, although other genes are also at work including HLA-B60 (B*40:01). Other genes have been identified, including those involved in peptide editing for loading onto class I MHC molecules (ERAP1) and cytokine genes such as interleukin 1A (IL-1A) and those involved in the Th17 network (IL-23R, an association seen primarily in Caucasians) and others. In acute anterior uveitis, these associations are also seen as well as a region on chromosome 9p and genes whose confirmation is under way. Psoriasis and psoriatic arthritis fall into this disease spectrum, with the largest region of susceptibility coming from the MHC (most likely HLA-C, ie, C*06:02 although additional influences are also being implicated), and most of the other genetic susceptibility coming from genes involved in cytokine production, specifically genes in the Th17 pathway (IL-12B, IL-23A and IL-23R, the latter, like in AS, not seen in Asians), genes in the nuclear factor κB pathway (TNFAIP3 and TNIP1) and genes in the Th2 pathway (IL-4 and IL-13). Given that more than half of patients with AS have evidence on colonoscopy of at least occult inflammatory bowel disease (IBD), it is not surprising that shared genetic influences are operative. In IBD, genes important in the innate immune response (NOD2), autophagy (ATG6L1) and regulation of the IL-23 pathway (IL-23R) play a role in disease susceptibility.
THE TRANSMISSION AND PERSISTENCE OF ‘URBAN LEGENDS’: SOCIOLOGICAL APPLICATION OF AGE-STRUCTURED EPIDEMIC MODELS

This paper describes two related epidemic models of rumor transmission in an age-structured population. Rumors share with communicable disease certain basic aspects, which means that formal models of epidemics may be applied to the transmission of rumors. The results show that rumors may become entrenched very quickly and persist for a long time, even when skeptics are modeled to take an active role in trying to convince others that the rumor is false. This is a macrophenomeon, because individuals eventually cease to believe the rumor, but are replaced by new recruits. This replacement of former believers by new ones is an aspect of all the models, but the approach to stability is quicker, and involves smaller chance of extinction, in the model where skeptics actively try to counter the rumor, as opposed to the model where interest is naturally lost by believers. Skeptics hurt their own cause. The result shows that including age, or a variable for which age is a proxy (e.g., experience), can improve model fidelity and yield important insights.
Surface Plasmon Structures for Surface-Enhanced Raman Scattering

Surface-enhanced Raman scattering (SERS) can enhance the intensity of Raman radiation by many orders of magnitude for molecules bound to metallic nanostructures. SERS is generally thought to have been a result of excitation of surface plasmons in nanostructured metal, which greatly enhances local electric field experienced by the molecule. Common SERS substrates fabricated using noble metal colloidal or electrochemically roughened thin films suffer from lack of homogeneity where only few hot spots yield high enhancement. We explore semiconducting nanowires and metallic nanorods as an economical, stable, and repeatable SERS substrate for the detection of trace amount of chemicals and bio-species. We utilize bulk synthesized semiconducting nanowires as nano-scale structures that can be coated with noble metals or their colloidal forms to allow for excitation of surface plasmons over broad frequency range. The use of nanowires as SERS substrates has several advantages. The surface properties of these nanowires are highly reproducible and well defined as compared to other systems like colloidal aggregates, electrochemical roughening etc. The synthesized nanowires offer many unique features (sharp vertices, noncircular cross-sections, inter-wire coupling) that may lead to larger field enhancement factors. High density of nanowires means close interaction between adjacent nanowires, which enables SERS to manifest for a broad selection of excitation sources. We have synthesized germanium dioxide and zinc oxide nanowires using the vapor-liquid-solid growth mechanism utilizing a simple quartz tube furnace set up. The nanowires are grown either using thin gold film (5–15 nm) or colloidal gold (20 nm or 60 nm) as catalyst on substrates of silicon and quartz. The resulting nanowires are dense and randomly distributed on the substrate. The nanowires are subsequently coated with thin films (10–21 nm) of gold that provide plasmons active surface. We have also investigated silver nanorods on glass formed by grazing angle deposition using e-beam evaporation. These nanorods have a diameter of 60±11 nm with lengths averaging 305±38 nm. These well aligned high aspect ratio and dense structures are ideal for excitation of surface plasmons. The synthesized structures have been characterized using SEM, TEM, and EDS. The SERS studies were conducted using EzRaman-L system from Enwave Optronics, Inc. Silver nanorods and gold-coated nanowires have been found to exhibit significant Raman enhancement for micro-molar concentrations of Rhodamine 6G and Nile blue, and are promising candidates for SERS applications.
Design objectives for the IBM stretch computer

It is apparent to every user of an electronic computer that there are areas in which major improvements are desired. Present computer speeds, remarkable as they are, still fall short of the requirements of many of today's business and technical applications. The labor of programming often delays or prevents the application of new problems to the machines. Maintenance continues to consume a significant fraction of the working day, and requires highly skilled engineers to locate and repair machine faults.
ESD failure mechanisms of inductive and magnetoresistive recording heads

Abstract The response of experimental thin-film (TF) recording head structures to excessive current and/or voltage during an electrostatic discharge (ESD) event is studied. Inductive and magnetoresistive-like (MR-like) magnetic recording head structures are tested and modeled from the viewpoint of electrostatic theory. An electrical model for the shielded MR-like head structure is proposed and used in circuit simulations to study the current flow during a human body model (HBM) and machine model (MM) transients. A testing methodology is defined using standard HBM and MM ESD transients. A thermal model for TF resistor burnout is compared with experiment and predicts a higher failure current than is measured. Results show that the MR structure can fail due to metalization burnout or air breakdown. The HBM metalization burnout failure voltage ranged from 100 to 300 V, while MM damage stated at 27 V. Air breakdown ranged from 550 to 650 V.
The Representation of Two Competing Visions on the Fundamentals of Copyright: A Content Analysis of Associated Press News Coverage on Copyright, 2004–2009

The importance of the public's understanding of copyright has increased in the digital age, and mainstream media play a significant role in informing the public of copyright law and policy. This study identifies two competing visions on the fundamentals of copyright—the private property vision and the public policy vision—and examines which vision is more predominantly covered by mainstream news media via a quantitative content analysis of Associated Press wire service stories on copyright. The findings suggest that, although the number of sources favoring copyright users’ rights has somewhat increased in the most recent two years, overall the private property vision has been more dominantly covered than the public policy vision in the AP news stories. The study concludes that the mainstream media coverage on copyright needs to move toward a more balanced point where both sides of the debate have an equal chance to present their views.
On the logic of iterated belief revision

Abstract We show in this paper that the AGM postulates are too weak to ensure the rational preservation of conditional beliefs during belief revision, thus permitting improper responses to sequences of observations. We remedy this weakness by proposing four additional postulates, which are sound relative to a qualitative version of probabilistic conditioning. Contrary to the AGM framework, the proposed postulates characterize belief revision as a process which may depend on elements of an epistemic state that are not necessarily captured by a belief set. We also show that a simple modification to the AGM framework can allow belief revision to be a function of epistemic states. We establish a model-based representation theorem which characterizes the proposed postulates and constrains, in turn, the way in which entrenchment orderings may be transformed under iterated belief revision.
Generation of 2-azapentadienyl anions and their cycloaddition with alkenes. Synthesis of 2-alkenylpyrrolidines

Abstract α,β-Unsaturated imines 2 bearing an N-[1-(tri-n-butylstannyl)]alkyl group were transmetalated with n-BuLi to generate 2-azapentadienyl anions 3 which underwent [4πs+2πs] anionic cycloadditions with alkenes to afford 2-alkenylpyrrolidines 4 after workup with an electrophile. The alkenyl group could be oxidized to a diol, aldehyde, or ester. The imine 2 was found to undergo a [1,5]-sigmatropic rearrangement of the tri-n-butylstannyl group at 80 °C to provide the 2-azabutadiene 5.
Superconformal flavor simplified

A simple explanation of the flavor hierarchies can arise if matter fields interact with a conformal sector and different generations have different anomalous dimensions under the CFT. However, in the original study by Nelson and Strassler many supersymmetric models of this type were considered to be ‘incalculable’ because the R-charges were not sufficiently constrained by the superpotential. We point out that nearly all such models are calculable with the use of a-maximization. Utilizing this, we construct the simplest vector-like flavor models and discuss their viability. A significant constraint on these models comes from requiring that the visible gauge couplings remain perturbative throughout the conformal window needed to generate the hierarchies. However, we find that there is a small class of simple flavor models that can evade this bound.
Hydrogen energy systems technology study

Abstract The National Aeronautics and Space Administration (NASA) Office of Energy Programs initiated the Hydrogen Energy Systems Technology (HEST) Study in the autumn of 1974. The Caltech Jet Propulsion Laboratory (JPL) was made responsible for conducting the study and reporting the results, with active support from several NASA Centres through a Working Panel. Objectives of the study were defined to be the assessment of national needs for hydrogen, based on current uses and visible trends, and determination of the critical research and technology activities required to meet these needs, with attention to economic, social, and environmental considerations, providing a basis for the planning of a hydrogen research and technology program. The HEST Study found current U.S. hydrogen utilization to be dominated by chemical-industry and petroleum-processing applications, and to represent 3% of total energy consumption. The study's projections of hydrogen uses show growth the remainder of this century by at least a factor of five, and perhaps a factor of twenty. New applications in the manufacture of synthetic fuels from coal and directly as an energy storage medium and fuel are expected to emerge later this century. Of these new uses, electric utility energy storage for peak-shaving, supplements to the natural gas supply and special purpose transportation fuel such as aircraft, show promise. The Study concludes that the development and implementation of new means of supplying hydrogen, replacing the use of natural gas and petroleum feedstocks, are imperative. New production technology is essential to support even the lowest growth estimate. Methods based on alternative fossil feedstocks, such as coal and heavy oils, which are less expensive and nearer to technical maturity than non-fossil production systems, should be made operational while these feedstocks are abundant. Concurrently, the long-term tasks of advancing electrolysis technology, researching other water-splitting techniques, and integrating these with developing nuclear and emerging solar primary-energy systems, must be carried on, together with work on hydrogen combustion systems and research in materials and safety engineering. Systems studies and assessments of the economic, social and environmental impacts of hydrogen technology are also called for.
On essential, (strictly) perfect equilibria

Abstract It is known that generic games within certain collections of infinite-action normal-form games have only essential equilibria. We point to a difficulty in showing that essential equilibria in generic games are (strictly) perfect, and we identify collections of games whose generic members have only essential and (strictly) perfect equilibria.
Independence in topological and C*-dynamics

We develop a systematic approach to the study of independence in topological dynamics with an emphasis on combinatorial methods. One of our principal aims is to combinatorialize the local analysis of topological entropy and related mixing properties. We also reframe our theory of dynamical independence in terms of tensor products and thereby expand its scope to C*-dynamics.
Management Behaviour as Social Capital: A Systematic Analysis of Organizational Ethnographies

This article explores managerial behaviour as a potential source of social capital in the workplace. Using content-coded data from the full population of organizational ethnographies (N = 204), we explore facets of workplace behaviours and relations that have been difficult to evaluate using survey-based techniques. Analysing ethnographic-based data with multivariate techniques, we find that competent management leadership, in particular, has widespread and significant effects on important workplace outcomes such as job satisfaction, organizational citizenship behaviour, and co-worker infighting. The findings highlight the value of cross-methods techniques for evaluating and extending existing workplace theories.