cssi/SciSciGPT-SciSciNet huggingface dataset:
A family of ideals with few generators in low degree and large projective dimension

Stillman posed a question as to whether the projective dimension of a homogeneous ideal I in a polynomial ring over a field can be bounded by some formula depending only on the number and degrees of the minimal gener- ators of I. More recently, motivated by work on local cohomology modules in characteristic p, Zhang asked more specifically if the projective dimension of I is bounded by the sum of the degrees of the generators. We define a family of homogeneous ideals in a polynomial ring over a field of arbitrary characteristic whose projective dimension grows exponentially if the number and degrees of the generators are allowed to grow linearly. We therefore answer Zhang's ques- tion in the negative and provide a lower bound to any answer to Stillman's question. We also describe some explicit counterexamples to Zhang's question including an ideal generated by 7 quadrics with projective dimension 15.
Phase I study of twice-weekly gemcitabine and concurrent thoracic radiation for patients with locally advanced non-small-cell lung cancer.

Abstract Purpose: To determine the maximum tolerated dose (MTD) and dose-limiting toxicity of twice-weekly gemcitabine and concurrent thoracic radiation in patients with Stage IIIa/IIIb non–small-cell lung cancer (NSCLC). Methods and Materials: Seventeen patients with histologically confirmed Stage IIIa and IIIb NSCLC were studied. Gemcitabine was administered via a 30-min i.v. infusion twice weekly for 6 weeks concurrent with 60 Gy of thoracic radiation. Gemcitabine, starting at a twice-weekly dose of 10 mg/m 2 (20 mg/m 2 /week), was escalated in 10–15 mg/m 2 increments in successive cohorts of 3 to 6 patients until dose-limiting toxicity was observed. Results: Of the 17 patients entered, 16 were evaluable for toxicity. The dose-limiting toxicity at 50 mg/m 2 given twice weekly (100 mg/m 2 /week) was Grade 3 pneumonitis observed in 1 patient, Grade 3 pulmonary fibrosis in a second patient, and Grade 4 esophagitis observed in two additional patients. Twice-weekly gemcitabine at a dose of 35 mg/m 2 was determined to be the MTD. The overall response rate for the 16 evaluable patients was 88%. The median survival for the entire group is 16.0 months. Conclusions: The MTD of twice-weekly gemcitabine is 35 mg/m 2 (70 mg/m 2 /week) given with thoracic radiation. A Phase II study within the Cancer and Leukemia Group B to ascertain the potential efficacy of this treatment regimen is in development.
Apoptotic osteocytes and the control of targeted bone resorption.

Studies from the 1950s and 1960s already recognize the fact that osteocytes, although long living cells, die, as evidenced by accumulation of osteocytic lacunae devoid of cells. More recently, it was demonstrated that these cells die by apoptosis. The rate of osteocyte apoptosis is regulated by the age of the bone, as well as by systemic hormones, local growth factors, cytokines, pharmacological agents, and mechanical forces. Apoptotic osteocytes, in turn, recruit osteoclasts to initiate targeted bone resorption. This results in the removal of “dead” bone and may improve the mechanical properties of the skeleton. However, the molecular regulators of osteocyte survival and targeted bone remodeling are not completely known. In this review, the current knowledge on the molecular mechanism that lead to osteocyte death or survival, and the signals that mediate targeted bone resorption is discussed.
Phenomenology of noncommutative field theories

Experimental limits on the violation of four-dimensional Lorentz invariance imply that noncommutativity among ordinary spacetime dimensions must be small. In this talk, I review the most stringent bounds on noncommutative field theories and suggest a possible means of evading them: noncommutativity may be restricted to extra, compactified spatial dimensions. Such theories have a number of interesting features, including Abelian gauge fields whose Kaluza-Klein excitations have self couplings. We consider six-dimensional QED in a noncommutative bulk, and discuss the collider signatures of the model.
A polarized 3He target for nuclear physics

Abstract A prototype polarized 3 He target based on optical pumping of metastables has been constructed and tested. The target employs an infrared laser to polarize 3 He atoms in a pyrex cell which is connected by a capillary to a copper cell at 87 K. With 20% polarization and a thickness of 4 × 10 18 cm −2 , the target has been routinely operated with 1 μA of 5 MeV protons passing through it. Using this technique it should be possible with increased laser power and lower temperatures to construct targets of 50% polarized 3 He with foil windows and a thickness of 5 × 10 18 cm −2 , or windowless targets of thickness 10 16 cm −2 for use in a storage ring.
On the equivalence of certain coset conformal field theories

We demonstrate the equivalence of Kazama–Suzuki cosets G(m, n, k) and G(k, n, m) based on complex Grassmannians by proving that the corresponding conformal precosheaves are isomorphic. We also determine all the irreducible representations of the conformal precosheaves.
Symptomatic change and gastrointestinal quality of life after pancreatectomy.

Background Pancreatectomy affects gastrointestinal (GI) symptoms. Our purpose was to assess the quality of life of pancreatectomy patients in relation to GI function.
Electron microscopy of the growth features and crystal structures of filament assisted CVD diamond films

Abstract Scanning and transmission electron microscopy (SEM and TEM) have been used to examine the topographic and internal features of diamond films grown by the hot filament assisted chemical vapor deposition method. Films were grown under conditions chosen to provide three distinctly different diamond microstructures. One of these film structures is virtually free of stacking faults and twins within the grains. This paper relates internal and external growth features to each other, to Raman spectra and to the growth conditions. The growth features are discussed in terms of growth mechanisms.
Radiant heat-transfer analysis of isothermal diathermanous coatings on a conductor.

gasdynamics of compressible vortices," ARS Progress in Astronautics and Rocketry: Energy Conversion for Space Power, edited by Nathan W. Snyder (Academic Press Inc., New York, 1961), Vol. 3. 19 Donaldson, C. DuP., "The magnetohydrodynamic vortex power generator: basic principles and practical problems," Proceedings of the Second Symposium of the Engineering Aspects of Magnetohydrodynamics (Columbia University Press, New York, 1962). 20 Mayo, R. F. and Davis, D. D., Jr., "Magnetically diffused radial electric-arc air heater employing water-cooled copper electrodes," AIAA Progress in Astronautics and Aeronautics: Electric Propulsion Development, edited by Ernst Stuhlinger (Academic Press, Inc. New York, 1963), Vol. 9. 21 Boldman, D. R., "Arc jet chamber design for spun d-c arcs," ARS Paper 2349-62 (March 14-16, 1962). 22 John, R. R., et al., "Theoretical and experimental investigation of arc-plasma generation technology," Pt. II, Vol. 2, Aeronautical Systems Div. ASD-TDR-62-729 (September 1963). 23 Rosenzweig, M. L., Lewellen, W. S., and Ross, D. H., "Confined vortex flows with boundary-layer interaction," AIAA J. 2, 2127-2134 (1964). 24 Lewellen, W. S., "Linearized vortex flows," AIAA J. 3, 91-98 (1965). 25 Kramer, E. L. and Gronich, S., "A transpiration-cooled nozzle as applied to a gas-core nuclear propulsion system," J. Spacecraft Rockets 2, 345-353 (1965).
A characterization of closure operations that induce big Cohen-Macaulay modules

The intent of this paper is to present a set of axioms that are sufficient for a closure operation to generate a balanced big Cohen-Macaulay module over a complete local domain . Conversely, we show that if such a exists over , then there exists a closure operation that satisfies the given axioms.
(Never) Mind your p's and q's: Von Neumann versus Jordan on the Foundations of Quantum Theory.

In early 1927, Pascual Jordan (1927b) published his version of what came to be known as the Dirac-Jordan statistical transformation theory. Later that year and partly in response to Jordan, John von Neumann (1927a) published the modern Hilbert space formalism of quantum mechanics. Central to both formalisms are expressions for conditional probabilities of finding some value for one quantity given the value of another. Beyond that Jordan and von Neumann had very different views about the appropriate formulation of problems in the new theory. For Jordan, unable to let go of the analogy to classical mechanics, the solution of such problems required the identification of sets of canonically conjugate variables, i.e., p’s and q’s. Jordan (1927e) ran into serious difficulties when he tried to extend his approach from quantities with fully continuous spectra to those with wholly or partly discrete spectra. For von Neumann, not constrained by the analogy to classical physics and aware of the daunting mathematical difficulties facing the approach of Jordan (and, for that matter, Dirac (1927)), the solution of a problem in the new quantum mechanics required only the identification of a maximal set of commuting operators with simultaneous eigenstates. He had no need for p’s and q’s. Related to their disagreement about the appropriate general formalism for the new theory, Jordan and von Neumann stated the characteristic new rules for probabilities in quantum mechanics somewhat differently. Jordan (1927b) was the first to state those rules in full generality, von Neumann (1927a) rephrased them and then sought to derive them from more basic considerations (von Neumann, 1927b). In this paper we reconstruct the central arguments of these 1927 papers by Jordan and von Neumann and of a paper on Jordan’s approach by Hilbert, von Neumann, and Nordheim (1928). We highlight those elements in these papers that bring out the gradual loosening of the ties between the new quantum formalism and classical mechanics.
Portable high-accuracy double spectrometer for ultraviolet spectral irradiance measurements

A portable high accuracy double spectrometer for ultraviolet (UV) spectral irradiance measurements has been under development at the National Institute of Standards and Technology (NIST) or several years. It has been used in the comparison of NIST spectral irradiance sources: an electron storage ring, 1000 W quartz-halogen lamps, deuterium arc lamps, and a windowless argon miniarc. A UV spectral irradiance intercomparison with the Physikalische Technische Bundesanstalt of Germany has also been carried out with the instrument. This paper will discuss the modular design of this instrument, preliminary uncertainty analysis, results of standard source comparisons and results of solar ultraviolet measurements using the UV spectrometer with the NIST spectral irradiance field calibrator.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Cosmology for Grand Unified Theories with Radiatively Induced Symmetry Breaking

The treatment of first-order phase transitions for standard grand unified theories is shown to break down for models with radiatively induced spontaneous symmetry breaking. It is argued that proper analysis of these transitions which would take place in the early history of the universe can lead to an explanation of the cosmological homogeneity, flatness, and monopole puzzles.
Vibration of elevator cables with small bending stiffness

The effects of bending stiffness and boundary conditions on the lateral vibration of the stationary and moving hoist cables are investigated. The role of the trial functions in the approximate methods is examined. The optimal stiffness and damping coefficient of the suspension of the car against its guide rails are identified for the moving cable.Copyright © 2002 by ASME
A Method of Analysis for Compressible Viscoelastic Solids

Most of the solutions in the development of methods of viscoelastic stress analysis have dealt with incompressible materials or materials with restrictions in dilatation. It is influenced in part by the increasing complexity due to the additional operator which represents the viscoelastic characteristics in dilatation. A simple procedure of solution is suggested in this paper which shows that a certain class of problems for compressible materials can be solved with the similar simplicity as the analysis of corresponding incompressible solids. Examples are given for problems with spherical boundaries.
Eating behavior and obesity at Chinese buffets.

Objective: The aim of this study was to investigate whether the eating behaviors of people at all-you-can-eat Chinese buffets differs depending upon their body mass. The resulting findings could confirm or disconfirm previous laboratory research that has been criticized for being artificial. Methods and Procedures: Trained observers recorded the height, weight, sex, age, and behavior of 213 patrons at Chinese all-you-can-eat restaurants. Various seating, serving, and eating behaviors were then compared across BMI levels. Results: Patrons with higher levels of BMI were more likely to be associated with using larger plates vs. smaller plates (OR 1.16, P < 0.01) and facing the buffet vs. side or back (OR 1.10, P < 0.001). Patrons with higher levels of BMI were less likely to be associated with using chopsticks vs. forks (OR 0.90,P < 0.05), browsing the buffet before eating vs. serving themselves immediately (OR 0.92, P < 0.001), and having a napkin on their lap vs. not having a napkin on their lap (OR 0.92, P < 0.01). Patrons with lower BMIs left more food on their plates (10.6% vs. 6.0%, P < 0.05) and chewed more per bite of food (14.8 vs. 11.9, P < 0.001). Discussion: These observational findings of real-world behavior provide support for laboratory studies that have otherwise been dismissed as artificial.
Electroreduction of nitrate ions in concentrated sodium hydroxide solutions at lead, zinc, nickel and phthalocyanine-modified electrodes

The electrochemical reduction of nitrate in strongly alkaline solution has been studied using nickel, lead, zinc and iron cathodes. Intermediate formation of nitrite ion and ammonia product was observed for all electrode materials. Coating a nickel sponge electrode with phthalocyanine renders it less active toward nitrate reduction, while iron electrodes appear to be activated. Electrolysis between a lead cathode and a nickel anode is an efficient means of removing nitrate from strongly alkaline solutions.
The Relationship of Human Saphenous Vein Intimal Area to Age and Gender

The saphenous vein is an essential element in arterial bypass surgery. It is known to develop intimal thickening following transplantation to the arterial circulation. No data are available on the relationship of normal saphenous vein intimal area and the age or the gender of the patient. One hundred sixty-two consecutive, donated, cadaveric, midtibial samples of the long saphenous vein were harvested. The donors ranged in age from twelve to eighty-two years; there were 121 males and 41 females. The areas of the intima and media and the intimal ratio (intimal area/[intimal + medial area]) were calculated by computer videomorphometry. There was no correlation between the three variables and age, but there was a significant correlation between the gender of the donor and the intimal area (r2=0.25, P=0.0012) and the intimal ratio (r2=0.34, p = 0.0001) showing that females have a greater intimal area than males.These findings suggest that gender should be considered as a variable in the choice of suitable con...
Analytical homogenization method for periodic composite materials

We present an easy-to-implement technique for determining the effective properties of composite materials with periodic microstructures, as well as the field distributions in them. Our method is based on the transformation tensor of Eshelby and the Fourier treatment of Nemat-Nasser et al. of this tensor, but relies on fewer limiting assumptions as compared to prior approaches in the literature. The final system of linear equations, with the unknowns being the Fourier coefficients for the potential, can be assembled easily without a priori knowledge of the concepts or techniques used in the derivation. The solutions to these equations are exact to a given order, and converge quickly for inclusion volume fractions up to 70%. The method is not only theoretically rigorous but also offers flexibilities for numerical evaluations.
A Spectroscopic Survey of Subarcsecond Binaries in the Taurus-Auriga Dark Cloud with the Hubble Space Telescope

We report the results of a spectroscopic survey of 20 close T Tauri binaries in the Taurus-Auriga dark cloud where the separations between primaries and their secondaries are less than the typical size of a circumstellar disk around a young star. Analysis of low- and medium-resolution Space Telescope Imaging Spectrograph spectra yields the stellar luminosities, reddenings, ages, masses, mass accretion rates, IR excesses, and emission-line luminosities for each star in each pair. We examine the ability of IR color excesses, Hα equivalent widths, [O I] emission, and veiling to distinguish between weak emission and classical T Tauri stars. Four pairs have one classical T Tauri star (CTTS) and one weak-lined T Tauri star (WTTS); the CTTS is the primary in three of these systems. This frequency of mixed pairs among the close T Tauri binaries is similar to the frequency of mixed pairs in wider young binaries. Extinctions within pairs are usually similar; however, the secondary is more heavily reddened than the primary in some systems, where it may be viewed through the primary's disk. Mass accretion rates of primaries and secondaries are strongly correlated, and Hα luminosities, IR excesses, and ages also correlate within pairs. Primaries tend to have somewhat larger accretion rates than their secondaries do and are typically slightly older than their secondaries according to three different sets of modern pre-main-sequence evolutionary tracks. Age differences for XZ Tau and FS Tau, systems embedded in reflection nebulae, are striking: the secondary in each pair is less massive but more luminous than the primary. The stellar masses of the UY Aur and GG Tau binaries measured from their rotating molecular disks are about 30% larger than the masses inferred from the spectra and evolutionary tracks. This discrepancy can be resolved in several ways, among them a 10% closer distance for the Taurus-Auriga dark cloud.
Growth and equilibrium indeterminacy: the role of capital mobility

The paper presents a human capital driven endogenous growth model which, in general, permits a multiplicity of equilibrium balanced growth paths. It is shown that allowing for perfect capital mobility across countries increases the range of parameter values for which the model permits equilibrium indeterminacy. As opposed to the closed capital markets case, simple restrictions on preferences are no longer sufficient to eliminate the indeterminacy. Intuitively, under perfect capital mobility agents are able to smooth consumption completely. This induces an economy with open capital markets to behave like a closed economy with linear preferences thereby increasing the possibility of equilibrium indeterminacy.
Full-Wave Iterative Image Reconstruction in Photoacoustic Tomography With Acoustically Inhomogeneous Media

Existing approaches to image reconstruction in photoacoustic computed tomography (PACT) with acoustically heterogeneous media are limited to weakly varying media, are computationally burdensome, and/or cannot effectively mitigate the effects of measurement data incompleteness and noise. In this work, we develop and investigate a discrete imaging model for PACT that is based on the exact photoacoustic (PA) wave equation and facilitates the circumvention of these limitations. A key contribution of the work is the establishment of a procedure to implement a matched forward and backprojection operator pair associated with the discrete imaging model, which permits application of a wide-range of modern image reconstruction algorithms that can mitigate the effects of data incompleteness and noise. The forward and backprojection operators are based on the k-space pseudospectral method for computing numerical solutions to the PA wave equation in the time domain. The developed reconstruction methodology is investigated by use of both computer-simulated and experimental PACT measurement data.
Perturbed Basins of Attraction

Let F be an automorphism of which has an attracting fixed point. It is well known that the basin of attraction is biholomorphically equivalent to . We will show that the basin of attraction of a sequence of automorphisms f 1, f 2, . . . is also biholomorphic to if every f n is a small perturbation of the original map F.
Material Enhancement in Protoplanetary Nebulae by Particle Drift through Evaporation Fronts

Solid material in a protoplanetary nebula is subject to vigorous redistribution processes relative to the nebula gas. Meter-sized particles drift rapidly inward near the nebula midplane, and material evaporates when the particles cross a condensation/evaporation boundary. The material cannot be removed as fast in its vapor form as it is being supplied in solid form, so its concentration increases locally by a large factor (more than an order of magnitude under nominal conditions). As time goes on, the vapor-phase enhancement propagates for long distances inside the evaporation boundary (potentially all the way into the star). Meanwhile, material is enhanced in its solid form over a characteristic length scale outside the evaporation boundary. This effect is applicable to any condensible (water, silicates, etc.). Three distinct radial enhancement/depletion regimes can be discerned by use of a simple model. Meteoritic applications include oxygen fugacity and isotopic variations, as well as isotopic homogenization in silicates. Planetary system applications include more robust enhancement of solids in Jupiter's core formation region than previously suggested. Astrophysical applications include differential, time-dependent enhancement of vapor phase CO and H2O in the terrestrial planet regions of actively accreting protoplanetary disks.
Future management concerns regarding office automation

The last few years I have become less interested in the vendor shows and I began wondering why? As I thought about going to a show a year ago I went through the usual process of mentally listing my chores and setting priorities. Well, the usual did not happen. I found that the most pressing activity was management awarness. I was already armed with knowledge of tools and correct procedures for procurement, but I had not adequately staffed management. They were not ready to buy. Why was I running off to another show then? I didn't. I set about putting together some ideas to help me reach management, not with the intention of pushing them into an undesirable situation, but searching for a way to gain their understanding. I am still working on it, and here are some of my thoughts.
Surface and peripheral doses of dynamic and physical wedges.

Purpose: The physical and dosimetric differences between three different wedge systems on a multileaf collimator (MLC ) equiped linear accelerator are discussed in this report. In particular, the in-field and peripheral surface doses from these wedge systems are measured and their clinical differences discussed. Methods and Materials: A parallel-plate chamber was used in a solid water phantom to measure the surface doses of the wedges. Published correction factors were used to convert relative ionization to relative surface dose. Measurements were performed for 6 and 18 MV photon beams for different field sizes, source-surface distances (SSD), and distances outside the field for peripheral dose measurements. Surface-dose profiles across a field in the wedge-gradient direction were measured for the dynamic and upper wedges. Dose profiles in the nonwedge gradient direction were measured for open beam as well as the three wedges using films at depths of maximum dose (d max ). Results: At 85 cm SSD, surface doses on the central axis under a dynamic wedge or upper wedges are similar to those of an open field, while those of a lower wedged field are as much as 100% higher. Differences in surface doses due to beam energy are relatively minor compared with differences due to SSD or wedge systems. Dynamic and upper wedges produce similar peripheral doses, much lower than those produced by the lower wedges. The surface dose profile across the field under the dynamic wedge has a higher slope than that under the upper wedge, when the difference in wedge angles is compensated for by normalization to the dose profile at d max . In the nonwedge gradient direction, the dose profiles at d max of both the upper and the lower wedges demonstrate a marked effect of oblique filtration of the primary beam, resulting in an off-axis ratio at 80% of the field width of 0.95, in contrast to the off-axis ratio of 1.05 in the open and the dynamic wedged fields. Conclusions: The three wedge systems produce significantly different surface and peripheral doses that should be considered in properly choosing a wedge system for clinical use. Dynamic wedge and upper wedge systems deliver surface and peripheral doses similar to those of open fields and much lower than the lower wedge system. Both physical wedge systems degrade beam profiles in the nonwedged direction.
Identifying effective hunters and farmers in the salesforce: a dispositional-situational framework

In business-to-business markets, hunting for new customers and farming existing customers are critical to achieve sales goals. Although practitioners suggest that salespeople have a preference for either hunting or farming, academic research has yet to examine when and why salespeople become oriented toward hunting or farming, and whether a simultaneous engagement in both (i.e., being ambidextrous) is efficient or damaging. In Study 1, the authors identify the link between regulatory focus and salesperson hunting and farming orientations. In Study 2, they demonstrate that (1) a promotion (prevention) focus is more strongly related to salesperson hunting (farming) orientation than is a prevention (promotion) focus, and (2) ambidextrous salespeople generate higher profits when they are customer oriented. In Study 3, the authors show that salesperson expectations about hunting success and the extent to which compensation plans are based on customer acquisition activities can change the direction of the relationship between regulatory focus and salesperson hunting and farming orientations. The authors discuss the implications of these findings for research and management of customer acquisition and retention at the salesperson level.
An anti-snapback circuit technique for inhibiting parasitic bipolar conduction during EOS/ESD events

Abstract In this work, an anti-snapback circuit technique called source injection (SI) is presented for the first time ever, which is shown to inhibit parasitic bipolar conduction during EOS/ESD events. The design is presented for a fully salicided, 0.25 μm, 35 A /70 A dual gate oxide, thin-epi, retrograde n-well, bulk CMOS technology. The technique is shown to greatly extend the snapback voltage of NMOS devices in this technology, which are usually destroyed instantaneously once snapback occurs. The design also has the benefit of controlling output buffer impedances for impedance matching to transmission-line loads. The design is fully compatible with the baseline process and has been shown to increase ESD robustness for positive discharge stress modes, which are the most difficult to protect for in epi processes. An increase of >1.5 kV is demonstrated for HBM, an increase of 550 V is shown for MM, and an increase of >550 V is exhibited for CDM, over non-SI and SI iopad designs, respectively.
Comets disguised as asteroids

Comets and asteroids were previously thought to be two completely distinct groups of solar-system objects, with marked contrast in both physical and dynamical characteristics. A comet is operationally defined by the presence of a coma, while an asteroid has no coma. However, recent observations have shown that comets can sometimes take on asteroidal appearances and even asteroidal photometric behavior. Thus the observational distinction between comets and asteroids is not as clear cut as it once seemed. The possible presence of comets hidden among known asteroids forces us to reconsider the criterion by which we distinguish comets from asteroids and possibly our inventory of both comet and asteroid populations.
Alcohol-free alternative activities for university students: modeling associated drinking behavior

Abstract An exploration of the linear relationships among alcohol use, participation in late-night alcohol-free entertainment options, perceived drinking norms, social identity, perception of university policy, and demographics was conducted. The sample was 1,074 college students enrolled in introductory psychology courses. Alcohol use was measured using self-report behavioral inventories. A total of 382 students participated in the study, 42% of whom attended one or more LateNight programs, and 52.7% of whom had binged within the past 2 weeks. Regression analysis results showed those who felt LateNight was a good example of having fun without using alcohol were 27% less likely to binge than those who did not believe this (p<.05). Likewise, those with high perceptions of peer drinking norms were 30% more likely to party heavily than those with low perceptions (p<.001). LateNight participants were significantly (p<.001) less likely to drink heavily, were 14% less likely to binge (p<.001), and were 20% less...
Reconstruction of Articulated Objects from Point Correspondences in a Single Uncalibrated Image

This paper investigates the problem of recovering information about the configuration of an articulated object, such as a human figure, from point correspondences in a single image. Unlike previous approaches, the proposed reconstruction method does not assume that the imagery was acquired with a calibrated camera. An analysis is presented which demonstrates that there is a family of solutions to this reconstruction problem parameterized by a single variable. A simple and effective algorithm is proposed for recovering the entire set of solutions by considering the foreshortening of the segments of the model in the image. Results obtained by applying this algorithm to real images are presented.
The relative advantages of flexible versus designated manufacturing technologies

Abstract This paper analyzes the choice between flexible and designated manufacturing technologies when firms can choose the flexibility of their manufacturing systems. Firms can operate a mix of technologies, a flexible system to serve some consumers and a designated technology to serve others and can offer multiple products. For flexible systems to be preferred these must offer strong economies of scope and be capable of producing customized products that are largely indistinguishable from custom-built products. An increase in submarket size or in the willingness of consumers to pay for particular types of products encourages the use of designated technologies.
A new phospholipid phosphatase, PRG-1, is involved in axon growth and regenerative sprouting

Outgrowth of axons in the central nervous system is governed by specific molecular cues. Molecules detected so far act as ligands that bind to specific receptors. Here, we report a new membrane-associated lipid phosphate phosphatase that we have named plasticity-related gene 1 (PRG-1), which facilitates axonal outgrowth during development and regenerative sprouting. PRG-1 is specifically expressed in neurons and is located in the membranes of outgrowing axons. There, it acts as an ecto-enzyme and attenuates phospholipid-induced axon collapse in neurons and facilitates outgrowth in the hippocampus. Thus, we propose a novel mechanism by which axons are able to control phospholipid-mediated signaling and overcome the growth-inhibiting, phospholipid-rich environment of the extracellular space.
Prescription data mining and the protection of patients' interests.

Pharmaceutical companies have exploited health information technology to “mine” data from drug prescriptions and use the data to better target their sales pitches to physicians. This article considers the policy arguments and first amendment implications regarding state regulation of data mining. It concludes that the legislative provisions are desirable and should withstand constitutional challenge.
Getting inside the “Black Box” of Head Start quality: What matters and what doesn’t

Abstract Critics of Head Start contend that many programs spend too much money on programs extraneous to children. On the other hand, Head Start advocates argue that the families of severely disadvantaged children need a broad range of services. Given the available evidence, it has been impossible to assess the validity of these claims. In this study, we match detailed administrative data with data on child outcomes from the National Longitudinal Survey of Youth 1979, including test scores, behavior problems, and grade repetition. We find that former Head Start children have higher reading and vocabulary scores where Head Start spending was higher. Holding per capita expenditures constant, children in programs that devoted higher shares of their budgets to child-specific expenditures have fewer behavior problems and are less likely to have been retained in grade.
A functional description of the Lincoln TX-2 computer

The TX-2 is a large scale digital computer designed and built at the Massachusetts Institute of Technology Lincoln Laboratory utilizing new memory and circuit components and some new logical design concepts. The computer will be applied as a research tool in scientific computations, and in data-handling and real-time problems. The design of the computer reflects not only the characteristics of the components available, but also the nature of the intended applications. This paper explains the functional and organizational aspects of the computer which are important from the user's point of view.
Detection of an X-Ray Pulsar Wind Nebula and Tail in SNR N157B

We report Chandra X-ray observations of the supernova remnant N157B in the Large Magellanic Cloud, which are presented together with an archival Hubble Space Telescope optical image and a radio continuum map for comparison. This remnant contains the recently discovered 16 ms X-ray pulsar PSR J0537-6910, the most rapidly rotating young pulsar known. Using phase-resolved Chandra imaging, we pinpoint the location of the pulsar at 5h37m4736, -69°10'204 (J2000), with an uncertainty of 1''. PSR J0537-6910 is not detected in any other wavelength band. The X-ray observations resolve three distinct features: the pulsar itself, a surrounding compact wind nebula that is strongly elongated (dimensions of ~0.6 × 1.7 pc), and a feature of large-scale (5 pc long) diffuse emission trailing from the pulsar. This latter comet-tail-shaped feature coexists with enhanced radio emission and is oriented nearly perpendicular to the major axis of the pulsar wind nebula. We propose the scenario below to explain these features. The bright, compact nebula is likely to be powered by a toroidal pulsar wind of relativistic particles that is partially confined by the ram pressure from the supersonic motion of the pulsar. The particles, after being forced out from the compact nebula (the head of the "comet"), are eventually dumped into a bubble (the tail), which is primarily responsible for the extended diffuse X-ray and radio emission. The ram-pressure confinement also allows a natural explanation for the observed X-ray luminosity of the compact nebula and for the unusually small X-ray to spin-down luminosity ratio of ~0.2%, compared to similarly energetic pulsars. We estimate the pulsar wind Lorentz factor of N157B to be ~4 × 106 (with an uncertainty of a factor of ~2), consistent with that inferred from the modeling of the Crab Nebula.
Capital structure with dividend restrictions

Abstract This paper develops a symmetric information model of a new firm which incorporates a constraint on dividend payments known as a balance sheet test. This test solves moral hazard problems that arise in credit markets where complete contracting over future actions is not possible. This constraint breaks down the traditional symmetric information result of separability between financial and real variables, and thus maximizing shareholder returns in this setting is not equivalent to maximizing total firm value. As a consequence, more profitable firms, those with a higher average product of capital, will have lower debt/equity ratios. Debt/equity ratios will be positively correlated with the firm's physical capital and negatively correlated with the firm's market power.
A new synthesis of amides from acyl fluorides and N-silylamines

Abstract Amide bonds are formed readily under mild conditions by the reaction of N-silylamines with the hydrolytically stable acyl fluorides.
Improving Dark Matter Searches by Measuring the Nucleon Axial Form Factor: Perspectives from MicroBooNE

Abstract The MicroBooNE neutrino experiment at Fermilab is constructing a liquid-argon time-projection chamber for the Booster Neutrino Beam to study neutrino oscillations and interactions with nucleons and nuclei, starting in 2014. We describe the experiment and focus on its unique abilities to measure cross sections at low values of Q 2. In particular, the neutral-current elastic scattering cross section is especially interesting, as it is sensitive to the contribution of the strange sea quark spin to the angular-momentum of the nucleon, Δ s . Implications for dark-matter searches are discussed.
Design of the HCl preflush in sandstone acidizing

HCl usually precedes an HF/HCl mixture in the sandstone acidizing process to reduce HF consumption by carbonates and to avoid the precipitation of HF reaction products. Assuming equilibrium reactions between injected HCl and calcium carbonate in a sandstone formation, the authors developed a numerical model of HCl frontal movement in the radial direction from the wellbore and added it to an existing sandstone acidizing simulator. In general, only small preflush volumes are needed to prevent live HF from coming in contact with high-pH regions. In almost all treatments, however, spent HF will penetrate beyond the live HCl front; larger HCl preflushes displace the region where spent HF comes in contact with undissolved carbonates in the formation farther from the wellbore. The new simulator predicts the distribution of HCl and HF in a multilayered formation with damage around the wellbore. Using this model the authors investigated the required size of the HCl preflush for a range of initial concentrations of HCl and carbonate. The authors also studied the influence of fluid diversion on the HCl frontal locations in multilayered reservoirs for multiple sequence treatments. In particular, they simulated treatments where HCl was injected without diversion, followed by an HF/HCl sequence includingmore » diverting agent to determine whether the HF would be diverted to regions that had not been reached by HCl.« less
Chandra Observation of Luminous and Ultraluminous X-Ray Binaries in M101

X-ray binaries in the Milky Way are among the brightest objects on the X-ray sky. With the increasing sensitivity of recent missions, it is now possible to study X-ray binaries in nearby galaxies. We present data on six ultraluminous binaries in the nearby spiral galaxy, M101, obtained with Chandra ACIS-S. Of these, five appear to be similar to ultraluminous sources in other galaxies, while the brightest source, P098, shows some unique characteristics. We present our interpretation of the data in terms of an optically thick outflow, and discuss implications.
Membrane photon sieve telescopes

We are investigating new technologies for creating ultra-large apertures (>20m) for space-based imagery. Our approach has been to create diffractive primaries in flat membranes to be deployed from compact payloads. This research has led us to the development of photon sieves in which millions of holes of a well-determined size are positioned over an otherwise opaque background. High resolution focusing is obtained for transmitted light. We have analyzed the theoretical performance of several types of photon sieves to improve both efficiency and bandwidth. We have also created several prototype devices in both rigid and flexible substrates.
Lutetium Triflate as an Efficient and Recyclable Catalyst for Chemoselective Thioacetalization of Aldehydes

Lutetium triflate has been found to be an efficient and recyclable catalyst for chemoselective thioacetalization of aldehydes.
Contrast and Synergy between Electrocatalysis and Heterogeneous Catalysis

The advances in spectroscopy and theory that have occurred over the past two decades begin to provide detailed in situ resolution of the molecular transformations that occur at both gas/metal as well as aqueous/metal interfaces. These advances begin to allow for a more direct comparison of heterogeneous catalysis and electrocatalysis. Such comparisons become important, as many of the current energy conversion strategies involve catalytic and electrocatalytic processes that occur at fluid/solid interfaces and display very similar characteristics. Herein, we compare and contrast a few different catalytic and electrocatalytic systems to elucidate the principles that cross-cut both areas and establish characteristic differences between the two with the hope of advancing both areas.
Water structure in the gramicidin a transmembrane channel

The interaction energy and the structure of water molecules either inside the gramicidin A transmembrane channel or at its two extremities has been examined by the use of iso-energy maps and Monte Carlo simulations. The shape of the channel as experienced by water has been analyzed in detail. Variations in the hydration structure due to the presence of a Na+ ion placed at several positions along the channel have been simulated and analyzed, and are discussed. Preliminary data on Li+ and K+ ions interacting with gramicidin A and the system of water molecules are reported.
An Empirical Analysis of the Strategic Use of Corporate Social Responsibility

Recent theories of the strategic use of corporate social responsibility (CSR) emphasize the role of information asymmetry and how CSR is likely to be incorporated into a firm's product differentiation strategy. A key empirical implication of these theories is that firms selling experience or credence goods are more likely to be socially responsible than firms selling search goods. Using firm-level data, we report evidence that is consistent with this hypothesis.
Defeaturing CAD models using a geometry-based size field and facet-based reduction operators

We propose a method to automatically defeature a CAD model by detecting irrelevant features using a geometry-based size field and a method to remove the irrelevant features via facet-based operations on a discrete representation. A discrete B-Rep model is first created by obtaining a faceted representation of the CAD entities. The candidate facet entities are then marked for reduction using a geometry-based size field. This is accomplished by estimating local mesh sizes based on geometric criteria. If the field value at a facet entity goes below a user-specified threshold value then it is identified as an irrelevant feature and is marked for reduction. The reduction of marked facet entities is performed using various facet operators. Care is taken to retain a valid geometry and topology of the discrete model throughout the procedure. The original model is not altered as the defeaturing is performed on a separate discrete model. Associativity between the entities of the discrete model and that of original CAD model is maintained in order to decode the attributes and boundary conditions applied on the original CAD entities onto the mesh via the entities of the discrete model. Example models are presented to illustrate the effectiveness of the proposed approach.
L-Band GaAs FET Amplifier

Low noise GaAs FET amplifier performance is enhanced at 1-2 GHz frequencies through the use of source inductance feedback. A simple circuit model predicts noise and signal performance and is used to derive matching circuits for the amplifier design. A 1-2 GHz single stage amplifier, designed on the basis of the modeled results, demonstrates <1.7dB noise figure, 15dB gain, and modest VSWR across the band. Over narrower band-widths, < ldB noise figure with 15dB of associated gain and <3:1 VSWR is demonstrated.
Conversion of non-conjugated dienes into conjugated diene-zirconocenes via multipositional regioisomerization

Abstract The reaction of n -Bu 2 ZrCp 2 with non-conjugated dienes ( 1 ) containing a mono- or 1,2-disubstituted alkene at one end and a 1,1-di- or trisubstituted alkene at the other gives conjugated diene-zirconocenes 2 via multipositional regioisomerization.
PROGNOSTIC IMPLICATIONS OF Q WAVES AND T WAVE INVERSION ASSOCIATED WITH EARLY REPOLARIZATION

Recent studies suggest an association between early repolarization (ER) and increased cardiovascular mortality. It has been reported, however, that this mortality is due to associated ECG abnormalities rather than the ER itself. Thus, given the high prevalence of ER, defining its associated risk
Addition and lithiation reactions of N-(1-phenylalkylidene)anilines with lithium dialkylamides

Abstract Lithium diisopropylamide undergoes an addition reaction to the methyleneamino moiety of the title Schiff's bases substituted with a cyano group at the ortho or para position of the aniline, but mediates tautomerization of the unsubstituted and meta-substituted derivatives into secondary enamines. Only the tautomerization is observed for lithium 2,2,6,6-tetramethylpiperidide-mediated reactions.
Qualitative and quantitative analysis of lignocellulosic biomass using infrared techniques: A mini-review

Current wet chemical methods for biomass composition analysis using two-step sulfuric acid hydrolysis are time-consuming, labor-intensive, and unable to provide structural information about biomass. Infrared techniques provide fast, low-cost analysis, are non-destructive, and have shown promising results. Chemometric analysis has allowed researchers to perform qualitative and quantitative study of biomass with both near-infrared and mid-infrared spectroscopy. This review summarizes the progress and applications of infrared techniques in biomass study, and compares the infrared and the wet chemical methods for composition analysis. In addition to reviewing recent studies of biomass structure and composition, we also discuss the progress and prospects for the applications of infrared techniques.
Optimization and NP_R-completeness of certain fewnomials

We give a high precision polynomial-time approximation scheme for the supremum of any honest n-variate (n+2)-nomial with a constant term, allowing real exponents as well as real coefficients. Our complexity bounds count field operations and inequality checks, and are polynomial in n and the logarithm of a certain condition number. For the special case of polynomials (i.e., integer exponents), the log of our condition number is sub-quadratic in the sparse size. The best previous complexity bounds were exponential in the size, even for n fixed. Along the way, we partially extend the theory of A-discriminants to real exponents and exponential sums, and find new and natural NPR-complete problems.
The Essential Spectrum of Schrödinger, Jacobi, and CMV Operators

We provide a very general result which identifies the essential spectrum of broad classes of operators as exactly equal to the closure of the union of the spectra of suitable limits at infinity. Included is a new result on the essential spectra when potentials are asymptotic to isospectral tori. We also recover within a unified framework the HVZ Theorem and Krein's results on orthogonal polynomials with finite essential spectra.