cssi/SciSciGPT-SciSciNet huggingface dataset:
Ordered sharing: a new lock primitive for database systems

We propose a new lock primitive called ordered sharing that allows increased concurrency in database systems. A generalized two phase locking protocol is developed that may employ locks with the standard shared and non-shared relationships as well as the proposed ordered shared relationships between locks. The paper then addresses the reliability and performance issues of the proposed protocol. We show that ordered sharing results in a set of protocols that are optimal in both their reliability and concurrency aspects. A simulation study demonstrates that ordered sharing results in improved performance in database systems. The general applicability of the new primitive is further demonstrated by using it in several representative database environments.
What is a Picturebook? Across The Borders of History

In this article I contemplate the ideas of art, narrative, and culture in picturebooks from a historical perspective. In particular, I define a picturebook as a visual verbal entity and explore the question, “How has the form of the picturebook manifested itself throughout human history?” I look at how changes in technology, culture, and society have influenced the picturebook as an art object from prehistoric times to the present day. Finally, I examine the role of the picturebook artist across the centuries and find common similarities in inspiration, intent, and motivation that link these artists despite the differences in the form and audience for picturebooks over time.
Crystallization and electrochemical performance of La0.6Sr0.4Co0.2Fe0.8O3 − δ-Ce0.8Gd0.2O1.9 thin film cathodes processed by single solution spray pyrolysis

Abstract La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 − δ -Ce 0.8 Gd 0.2 O 1.9 (LSCF–CGO) thin films obtained by spray pyrolysis of a single precursor solution were investigated by XRD, TEM and impedance spectroscopy at annealing temperatures ranging from 500 to 900 °C. Films annealed at 600 °C contained a mixture of amorphous regions and crystalline regions composed of fine crystallites (
Stability Analysis for Variable Frequency Operation of Synchronous Machines

A stability study of a synchronous machine is performed by applying the Nyquist stability-criterion to the equations which describe the behavior of the machine during small displacements about a steady-state operating point. This investigation reveals that, in some cases, machine instability can occur at low operating speeds. Regions of machine stability are established from the results of a digital computer study and the maximum resonance peak Mm is used as a criterion for determining relative stability when the response of the electromechanical system is damped. The effect on machine stability for changes in different system parameters is given. Also, the maximum resonance peak is used to establish an equivalent second-order electromechanical system. The response of this system is found to compare favorably to that of an idealized synchronous machine at any operating speed.
One-step percutaneous nephrolithotomy sheath versus standard two-step technique

Abstract Objectives Advances in technique and equipment have allowed urologists to perform percutaneous stone removal with increasing efficacy and decreasing complications. The procedure of choice for large renal calculi is percutaneous nephrolithotomy. At our institution, percutaneous access is achieved by a two-step process using either Amplatz dilators or placement of a high-pressure balloon catheter for tract dilation, followed by advancement of a sheath over the balloon. A novel device, the Pathway Access Sheath (PAS) has been developed that allows for balloon tract dilation and percutaneous access sheath placement in one simple step. Methods Our study population consisted of 21 patients, who were randomized to one of two arms. Of the 21 patients, 10 underwent standard two-step access using a high-pressure balloon catheter and 11 underwent percutaneous nephrolithotomy using the novel PAS. We compared the insertion time, blood loss, and cost between the two techniques. Results The average insertion time was shorter in the PAS group (3 minutes) compared with the high-pressure balloon catheter (5 minutes, 42 seconds); a difference that was statistically significant ( P Conclusions The results of our study have shown that a novel single-step renal access device is safe and efficacious and results in a shorter insertion time for percutaneous nephrolithotomy. Blood loss was less in the PAS group as well, although the difference was not statistically significant. Additional studies will establish whether this device will provide a new standard of obtaining renal access.
The use of electrical conductivity experiments to study the phase diagram of carbon

Abstract Recent theoretical and experimental work on the properties of carbon at very high pressures indicates that the diamond phase may dominate the carbon phase diagram. The work of Yin and Cohen indicates that diamond may be the stable carbon phase to pressures as high as 20 Mbar. Recent work by Shaner et al. is compatible with solid diamond on the Hugoniot at pressures up to 1.4 Mbar. Using previously developed techniques, we have carried out conductivity measurements on shock-compressed graphite to pressures in excess of 600 kbar and temperatures up to 5000 K. Our data show the transition from graphite-like to solid diamond-like behavior under these conditions.
Effects of experimental manipulations on the life history pattern of Lymnaea stagnalis appressa say (pulmonata: lymnaeidae)

Field sampling of an Iowa population of Lymnaea stagnalis appressa Say indicated an annual generation pattern, with survivorship to maturity of i percent or less. Estimates of adult fecundity ranged from about 300 to 800 eggs.
Eddy structure and the West Australian current

Abstract Four cruises in the summers of 1972 and 1973 in an 8 × 8° area were planned to investigate mesoscale and large-scale circulation off the southwest Australian coast in the West Australian Current. A trough with its base centered over the Naturaliste Plateau extends 800 km northeast to the coast; this constitutes the West Australian Current which is a 100- to 200-km wide cyclonic stream turning poleward as a coastal southerly. The transport of about 10 7 m 3 s −1 is confined near the surface. Currents are on average 0.5 m s −1 and have a scale depth of about 370 m; speeds up to 1.5 m s −1 are observed. Far off shore, near-zonal Rossby waves coexist with the stream giving a meandering surface effect. Near the shelf the southerly also meanders, giving a coastal mesoscale planetary wave with a meridional wavevector. Both systems have a wavelength of about 300 to 380 km. Surface samples have a T–S signature which identifies with the subtropical high salinity surface water in the central Indian Ocean. Advection of heat in the surface mixed layer reflects the pattern of the trough and of the Rossby waves. Mixed layer depth patterns show the meridional coastal wave in general but during high winds and surface cooling they also show the Rossby waves and the large scale cyclonic current. The current is unlike other eastern boundary currents and dynamically has some features of western boundary currents in addition to the meandering poleward flow: lateral shear vorticity and inertial curvature vorticity are less important than the change in planetary vorticity, but only marginally so.
Abstract A14: Transforming growth factor beta signaling regulates the fate of intestinal stem cells

Transforming growth factor beta signaling has important roles in stem cell behavior, differentiation, cell motility, cell cycle and apoptosis. Here, we have utilized a novel mouse model that facilitates the sporadic inactivation of TgfβR2 via frameshift reversion of Cre in single, isolated cells and concomitant lineage tracing with a Cre-reporter. Short-term lineage tracing of TgfβR2-deficient crypts revealed reduced expansion suggesting a growth disadvantage among crypts. In contrast, long-term lineage tracing of TgfβR2-deficient crypts revealed an increased number suggesting a growth advantage within the crypt. To reconcile these apparently contradictory findings, we studied the dynamics of proliferative, Lgr5+ stem cells following TgfβR2 loss. We found that TgfβR2-deficient stem cell lineages required more time to reach monoclonality within the crypt. Using mathematical modeling of stem cell neutral drift, we found that increased “stemness” or a greater probability of a self-renewing asymmetrical outcome for TgfβR2-deficient stem cells was more consistent with our experimental results. Further analysis of TgfβR2-deficient stem cells in vivo revealed a decreased production of Paneth cells, a finding we corroborated in cultured intestinal organoids by treating with either a TgfβR1/2 inhibitor or low levels of the Tgfβ1 ligand. Recent studies by others suggested that quiescent stem cells are intermediaries between proliferative Lgr5+ stem cells and Paneth cells and that Tgfβ signaling is important in the formation of quiescent stem cells in other tissues. Therefore, we are currently asking whether Tgfβ signaling is important in the formation of quiescent stem cells in the intestine. Citation Format: Jared M. Fischer, Ashleigh Miller, Peter P. Calabrese, Darryl Shibata, R Michael Liskay. Transforming growth factor beta signaling regulates the fate of intestinal stem cells. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A14.
Advanced Techniques for Clay Mineral Analysis

Advanced Techniques for Clay Mineral Analysis is a collection of review articles dealing with nine analytical techniques: thermoanalytical methods, high resolution electron-microscopy studies, neutron scattering techniques, nuclear magnetic resonance, Mossbauer spectroscopy, electron spin resonance, ultraviolet and visible light spectroscopy, far infrared spectroscopy, and electron spectroscopy for chemical analysis (ESCA). Each chapter includes some discussion of theory as it relates to a particular technique, but the main emphasis according to J. J. Fripiat, the editor, was to be directed toward summarizing recent developments of clay research applications. In fact there is an unevenness in this regard. Some authors (e.g., P. L. Hall on neutron scattering and J. P. Eberhart on high resolution electron-microscopy) have devoted a significant proportion of their articles to theoretical discussion, while other authors (T.J. Pinnavaia on electron spin resonance studies of clay minerals and R. D. Mackenzie on thermoanalytical methods) have no general discussion of theory.
Velocity profiles in a baffled vessel with single or double pitched-blade turbines

A laser-Doppler velocimetry (LDV) apparatus and a computational fluid dynamic (CFD) software package (FLUENT) were used to experimentally determine and numerically predict the velocities in a baffled vessel agitated by one or two 45{degree} pitched-blade turbines. The flow characteristics in the impeller regions were measured by LDV and used as boundary conditions in the numerical computations. Turbulence effects were simulated using either the {kappa}-{epsilon} model or algebraic stress model (ASM). The CFD predictions were compared to the LDV measurements in terms of average velocities in all three directions as well as turbulent kinetic energies. Predictions based on ASM were typically in closer agreement with the experimental data than those based on the {kappa}-{epsilon} model. Flow patterns in both configurations were dominated by the axial and tangential components. The presence of the upper impeller altered the flow considerably, producing a strong vertical recirculation pattern between the impellers and significantly reducing the circulation flow below the lower impeller.
All-Optical Label Swapping for 400G Optical Flow Switched Metro and Inter-Datacenter Networks using OpenFlow-based SDN Control

We demonstrate SDN-controlled OpenFlowl.O-based all-optical label swapping for optical flow switched metro/inter-datacenter networks. Negligible penalty is confirmed for dual-carrier 400-Gb/s payload and 10GbE optical labels, with label and payload jointly occupying <100-GHz spacing.
Exploring and crossing the disparity divide in cancer mortality.

Disparities in health care access and health outcomes in the United States present a significant challenge. Two articles in this issue discuss cancer screening in special populations. One reports f...
Reactions of Indene and Indoles with Platinum Methyl Cations: Indene C−H Activation, Indole π versus Nitrogen Lone-Pair Coordination

Reactions of indene and various substituted indoles with [(diimine)Pt^(II)(Me)(TFE)]^+ cations have been studied (diimine = ArNC(Me)−C(Me)NAr; TFE = 2,2,2-trifluoroethanol). Indene displaces the TFE ligand from platinum to form a stable π coordination complex that, upon heating, undergoes C−H activation with first-order kinetics, ΔH^⧧ = 29 kcal/mol, ΔS^⧧ = 10 eu, and a kinetic isotope effect of 1.1 at 60 °C. Indoles also initially form coordination complexes through the C_2=C_3 olefin, but these undergo rearrangement to the corresponding N-bound complexes. The relative rates of initial coordination and rearrangement are affected by excess acid or methyl substitution on indole.
Letter to the Editor---Comments on a Paper by Bowman

In the paper, “Assembly-Line Balancing by Linear Programming,” that appeared in Operations Research8, 385--389 1960, E. H. Bowman presented two linear program formulations for the assembly-line balancing problem. These two formulations are referred to as the First Linear Program and the Second Linear Program, respectively. The following are comments about, and a reformulation of, the First Linear Program.
Number of Replications Required in Control Chart Monte Carlo Simulation Studies

Monte Carlo simulations have been used extensively in studying the performance of control charts. Researchers have used various numbers of replications in their studies, but almost none of them provided justifications for the number of replications used. Currently, there are no empirically based recommendations regarding the required number of replications to ensure accurate results. This research examined six recently published studies to develop recommendations for the minimum number of replications necessary to reproduce the reported results within a specified degree of accuracy. The results of this study indicated that using 10,000 replications was unnecessarily large and a smaller number of replications could be used to reproduce the target ARLs within the 2% error bands satisfying the modified Mundfrom's criteria. In many cases, only 5,000 replications or fewer were required. In general, the number of replications required to reproduce the target ARL decreased as the shift size increased. In additio...
Mortality Rate in Rheumatoid Arthritis Patients Developing Necrotizing Scleritis or Peripheral Ulcerative Keratitis: Effects of Systemic Immunosuppression

We performed a nonrandomized clinical trial comparing the ocular and systemic efficacy of cytotoxic immunosuppression with steroidal and nonsteroidal anti-inflammatory therapy in the care of 34 patients with rheumatoid arthritis who developed peripheral ulcerative keratitis and/or necrotizing scleritis. Nine of the 17 patients managed with conventional therapy died of a vascular-related event during the ten-year period of the study. In 13 of the 17 patients, the ocular inflammatory process progressed, and in 5 patients extraocular, although nonlethal, vasculitic lesions developed. One of 17 patients treated with long-term immunosuppressive therapy died during the ten-year follow-up period, and this death occurred after cytotoxic therapy was withdrawn. None of the patients on immunosuppressive regimens developed extraocular vasculitis while taking the drug, and none had progression of the ocular destructive lesion. The results of this study emphasize that the eye is a sensitive indicator for potentially lethal occult systemic vasculitis in patients with rheumatoid arthritis who develop peripheral ulcerative keratitis or necrotizing scleritis. Our mortality data strongly suggest that the use of cytotoxic drugs may alter favorably the general as well as the ocular prognosis in these patients.
Work in Progress: Evaluating the Effectiveness of Telephone Calls from Faculty on the Matriculation of High School Students

During the 2005-2006 academic year, the University of San Diego (USD) Engineering Programs is conducting a study to measure the impact of phone calls on student matriculation. Admitted students were divided into two groups having similar demographic characteristics. One group will received phone calls from engineering faculty, the other group is a control and was not be contacted by the faculty. The impact of the phone calls will be assessed to determine whether receiving a call affected matriculation rates of admitted students. The results of these analyses will help to determine how faculty telephone calls should be used in future recruiting efforts.
Bilateral medial rectus muscle recession and lateral rectus muscle resection in the treatment of congenital esotropia

In a retrospective study of 36 patients with congenital esotropia treated surgically by bilateral medial rectus muscle recession and lateral rectus muscle resection, we found that 22 patients (61%) had not required further surgery and that 14 patients (39%) had required further corrective surgery. Seven of these 14 patients had overcorrections and seven had undercorrections. Patients who required a second operation were significantly younger (mean age, 12 months) than those who did not (mean age, 23 months). The most common second surgical procedure was bilateral tenotomy or disinsertion of the inferior oblique muscle. Bilateral medial rectus muscle recession and lateral rectus muscle resection is useful in severe (50 prism diopters or more) congenital esotropia. The surgical success rate may be improved with bilateral inferior oblique muscle disinsertions or tenotomies in patients with inferior oblique muscle overaction. Accurate preoperative examinations in patients old enough to cooperate may help avoid overcorrection and undercorrection.
Absolute Radiometric Calibration of Narrow-Swath Imaging Sensors With Reference to Non-Coincident Wide-Swath Sensors

An inter-calibration method is developed to provide absolute radiometric calibration of narrow-swath imaging sensors with reference to non-coincident wide-swath sensors. The method predicts at-sensor radiance using non-coincident imagery from the reference sensor and knowledge of spectral reflectance of the test site. The imagery of the reference sensor is restricted to acquisitions that provide similar view and solar illumination geometries to reduce uncertainties due to directional reflectance effects. Spectral reflectance of the test site is found with a simple iterative radiative transfer method using radiance values of a well-understood wide-swath sensor and spectral shape information based on historical ground-based measurements. At-sensor radiance is calculated for the narrow-swath sensor using this spectral reflectance and atmospheric parameters that are also based on historical in-situ measurements. Results of the inter-calibration method show agreement on the 2-5% level in most spectral regions with the vicarious calibration technique relying on coincident ground-based measurements referred to as the reflectance-based approach. While the variability of the inter-calibration method based on non-coincident image pairs is significantly larger, results are consistent with techniques relying on in-situ measurements. The method is also insensitive to spectral differences between the sensors by transferring to surface spectral reflectance prior to prediction of at-sensor radiance. The utility of this inter-calibration method is made clear by its flexibility to utilize image pairings with acquisition dates differing in excess of 30 days allowing frequent absolute calibration comparisons between wide- and narrow-swath sensors.
Tales Publicly Allowed: Competence, Capacity, and Religious Belief

What should we make of someone whose beliefs prevent her from accurately understanding her medical needs and care? Should that person still make her own health care decisions? In fact, she probably lacks decision-making capacity. But that does not mean she is not competent.
Position of the occlusal plane in natural and artificial teeth

Abstract A roentgenographic cephalometric investigation was conducted to compare the position of the occlusal plane of the artificial teeth with that of the natural teeth which existed before the remaining teeth were extracted. The occlusal plane of the trial dentures was first oriented to parallel the alatragus line and then modified so the occlusal surfaces of the second molars were placed at the level of the middle third of the retromolar pad. This location of the artificial occlusal plane was found to be at a lower level than the natural one in the posterior region. Hence, our findings indicate that the occlusal plane should be positioned so the second molars are placed at the level of the upper third of the retromolar pad.
Efficiency of a Low-Energy Wetted-Surface Multi-Annulus Denuder Sampler for Viable and Nonviable Aerosol Collection

ABSTRACT Capture efficiency of a wetted-surface low-energy sampler (LES) was evaluated for polystyrene latex (PSL) microsphere aerosol and a Bacillus subtilis aerosol. The observed absolute capture efficiency for PSL microspheres was higher than predicted by theory for the particle sizes used (0.7, 1.6, and 3.0 μm), suggesting hygroscopic particle growth via water uptake by residual detergent coatings. Bio-aerosol capture efficiency was evaluated relative to the AGI-30 impinger using mature B. subtilis. The bioaerosol was quasi-monodisperse with MMAD approximately 1 μm and GSD 1.2–1.3. Observed efficiencies for B. subtilis were substantially better for the LES than the AGI-30 at the lowest sampling flow rate used (5 L/min), but relatively poor at higher flow rates. Factors potentially influencing sampling efficiency were improved viability maintenance and adequate hygroscopic bioorganism growth in the LES. These results demonstrate that low-energy bioaerosol sampling using a wetted-surface multi-annulus d...
The use of an interactive computerized daily schedule in a busy interventional radiology practice increases efficiency.

Purpose The effect on efficiency of patient care in a busy academic interventional radiology practice was studied by the analysis of procedure times both before and after the implementation of a computerized interactive daily schedule. Procedure start and end times were retrospectively collected from the department's quality assurance database for two identical 6-month periods, representing the time before and after the deployment of the software. The delay in the start of the first case, the time between cases, and the time required to complete each day's work were compared for the two periods. Results The average time of delay between cases was reduced after the implementation of the software ( p p p = 0.08). There was no apparent effect on the average delay of the start of the day's first case ( p = 0.34). Conclusion The use of a computerized interactive daily schedule has a positive effect on departmental efficiency by allowing more cases to be performed without lengthening the workday.
Low-noise custom VLSI for CdZnTe pixel detectors

A custom analog VLSI chip is being developed for the readout of pixellated CdZnTe detectors in the focal plane of an astronomical hard X-ray telescope. The chip is intended for indium bump bonding to a pixel detector having pitch near 0.5 mm. A complete precision analog signal processing chain, including charge sensitive preamplifier, shaping amplifiers and peak detect and hold circuit, is provided for each pixel. Here we describe the circuitry and discuss the performance of a functional prototype fabricated in a 1.2um CMOS process at Orbit Semiconductor. Dynamic performance is found to be close to SPICE model predictions over a self-triggering range extending from 1 to 150 keV (200 to 30000 electrons). Integral nonlinearity (1 %) and noise (0.25 keV or 50 electrons FWHM with 200 fF input capacitance) while acceptable are not as good as predicted. Power consumption is only 250 uW per pixel. Layout and design techniques are discussed which permit successful self-triggering operation at the low 1 keV threshold.
Tracing nitrogen movement in corn production systems in the North Carolina Piedmont: analysis of nitrogen pool size

The fate of N in North Carolina Piedmont corn (Zea mays L.) was traced using N pool size analysis. In 1989 and 1990, selected N pools [corn; weeds; surface residues; and soil NH ᵃʳʳᵃⁿᵍᵉ⁼"ˢᵗᵃᶜᵏ">⁺₄ NO⁻₃, and potentially mineralizable N (Nₒ)] were sequentially sampled in four reduced chemical input systems: (i) crimson clover (Trifolium incarnatum L.) with conventional tillage (clover-till), (ii) no cover crop with conventional tillage and 70 kg N ha⁻¹ as NH₄NO₃ (fertilizer-till), (iii) crimson clover with strip-tillage (clover-strip), and (iv) no cover crop with no tillage and 70 kg N ha⁻¹ as NH₄NO₃ (fertilizer-no-till). The largest of the repeatedly measured N pools was soil Nₒ, which accounted for <10% of the total Kjeldahl soil N. Soil Nₒ was highest in the clover-till treatment, and had large seasonal fluctuations: 170 to 255 kg N ha⁻¹ in clover- till, and 117 to 210 kg N ha⁻¹ in other treatments. Fertilizer treatments had higher inorganic N levels than did clover treatments only immediately after fertilizer application. Although clover shoots contained 97 to 134 kg N ha⁻¹ yr⁻¹, more than the N applied to fertilizer treatments, no significant differences among treatments in plant (corn + weed) aboveground N accumulation (38 to 132 kg N ha⁻¹) were observed. Of these totals, weed N accounted for 5 to 30 kg N ha⁻¹. Surface residue N content was highest in reduced tillage treatments. In reduced chemical input systems such as these, N transfers among soil Nₒ, weed, and residue pools may be as large or larger than N transfers among soil inorganic and crop pools.
Characterization of North American Lignite Fly Ashes II. XRD Mineralogy

X-ray powder diffraction has been used to determine the crystalline phase mineralogy in samples of fly ash from each of the lignite mining areas of North America. The characteristic phases of North Dakota lignite fly ashes were periclase, lime, merwinite and the sulfate phases anhydrite, thenardite and a sodalite-structure phase. Mullite was absent in these low-Al 2 O 3 ashes. Montana lignite ash mineralogy had characteristics of ND lignite and MT subbituminous coal fly ashes; mullite and C 3 A were present and the alkali sulfates were absent. Texas and Louisiana lignite fly ashes had the characteristic mineralogy of bituminous coal fly ash: quartz, mullite, ferrite-spinel (magnetite) and minor hematite. Even though their analytical CaO contents were 7–14%, all but one lacked crystalline CaO-containing phases. Lignite fly ashes from Saskatchewan were generally the least crystalline of those studied and had a mineralogy consisting of quartz, mullite, ferrite spinel and periclase. Quantitative XRD data were obtained. The position of the diffuse scattering maximum in the x-ray diffractograms was indicative of the glass composition of the lignite fly ash.
Standardized management improves outcomes after the Norwood procedure.

Background. In the past decade, many advances in the care of patients undergoing the Norwood procedure (NP) have been reported, but management remains nonstandardized at many institutions. We studied the impact of a standardized management protocol for neonates undergoing NP. Methods. Care of NP patients has been protocol-driven at our institution since 2005, with routine use of regional low flow perfusion; near infrared spectroscopy; phenoxybenzamine with cardiopulmonary bypass; delayed sternal closure; peritoneal drainage; gastrostomy tubes; postoperative vocal cord assessment; and a home surveillance program of daily weight and oxygen saturation measurement. Patients undergoing NP from 2001 to 2004 (n = 40, group 1), in whom these interventions were only selectively employed, were retrospectively compared with those receiving standardized management from 2005 to 2007 (n = 40, group 2), with endpoints of survival in-hospital and to stage 2 palliation (S2P). Effect of protocol elements on outcome was evaluated by univariate and multivariate analyses. Results. Hospital survival (95% vs. 70%, P= .003) and survival to S2P (85% vs. 58%, P= .006) was better in group 2. By univariate analysis, regional low flow perfusion, gastrostomy usage, and near infrared spectroscopy were associated with improved hospital and survival to S2P. In multivariable analysis, gastrostomy usage was associated with improved hospital survival (P= .027) and survival to S2P (P= .049), while our home surveillance program was a predictor of survival to S2P (P= .016). Conclusion. Protocol-driven management of NP patients was associated with better hospital survival and survival to S2P. Among protocol elements, gastrostomy usage was linked to both improved hospital survival and survival to S2P. Home surveillance was associated with increased survival to S2P.
Determination of Primary Amino Groups by Reaction Chromatography

Abstract A gas chromatographic method is described for the assay of primary amino groups. The technique is a modification of the Van Slyke method, in which the N2 liberated by the reaction of primary amino groups with nitrous acid is measured by GC. The assay of amino acids, monosodium glutamate, Shake'n Bake and Adolph's Sugar Substitute is described.
Assembly and intracellular transport of HLA-DM and correction of the class II antigen-processing defect in T2 cells

Abstract MHC class II molecules expressed in T2 cells fail to acquire a normal complement of endocytically generated peptides. The defect is repaired by introducing HLA-DMA and HLA-DMB cDNA expression vectors, determined by the restoration of SIDS stability of class II αβ dimers, restoration of a normal conformation for HLA-DR3 as detected by a monoclonal antibody, and by a reduction in class II-associated invariant chain peptides. The intracellular distribution of class II and invariant chain molecules is also restored to that of wild-type cells. The HLA-DMA and HLA-DMB products appear to form a heterodimer that, although transported at least to the medial Golgi, is not expressed at the cell surface. These findings are consistent with HLA-DM functioning intracellularly to facilitate class II-restricted antigen processing.
Monte Carlo algorithms for expectation values of coordinate operators

Abstract Two Monte Carlo algorithms for computing quantum mechanical expectation values of coordinate operators, i.e., multiplicative operators that do not commute with the Hamiltonian, are presented and compared. The first employs a single quantum Monte Carlo (QMC) random walk, while the second involves a variational Monte Carlo (VMC) random walk with auxiliary QMC “side walks.” The tagging algorithm used for efficiently tracking descendants of a walker is described in detail for each approach. For the single-walk algorithm it is found that carrying weights together with branching significantly improves efficiency. Exploitation of the correlation between VMC and QMC expectation values is also considered. Large increases in efficiency in the second approach are found when such correlations are incorporated. It is found that both approaches readily yield accuracies and precisions of better than 0.5% for the model systems treated here, namely, H and H 2 . The second method, involving a VMC walk with auxiliary QMC walks, is the more efficient for these systems.
Queering Without Difference

Childhood is certainly long overdue as a site of queer activism. During the last 20 years, as LGBT visibility has increased in other domains; educators, administrators, sundry homophobes, and even ...
Electrophoretic analysis of protein changes during the development of the French bean fruit

Abstract The protein complement of bean ( Phaseolus vulgaris ) seeds and pods was shown to change greatly during fruit development. Synthesis of storage protein was initiated when the seed attained 10 mm length, the subsequent accumulation rapidly diluting out other proteins readily detectable after electrophoresis on acrylamide gels of extracts from younger seeds. In contrast, the number of bands obtained on electrophoresis of proteins from the pod decreased as a result of degradative changes as the fruit matured.
Influence of preparative procedure on the activity and selectivity of FeZSM-5 catalysts in syngas conversion

Abstract The ZSM-5 supported iron catalysts have been investigated with respect to physical and chemical properties and to activity and product selectivity for conversion of synthesis gas to hydrocarbon products. The catalyst preparations consisted of (1) direct decomposition of (C5H5Fe(CO)2)2 on ZSM-5, (2) impregnation of ZSM-5 with an aqueous solution of iron nitrate, and (3) physical admixture of precipitated iron oxide with ZSM-5. Some H2 and CO chemisorption studies and magnetization measurements were conducted to measure the average metal crystallite size. At the metal loading of about 8 wt%, the catalysts prepared by the first method produced higher metal dispersion compared to the other two methods of preparation, although the amount of aromatic compounds in liquid hydrocarbon products was very low. Infrared studies of chemisorbed pyridine on these samples indicate that ion exchange of Fen+ for acidic protons occurs in aqueous solution impregnated catalysts, while no ion exchange is found in organometallic impregnated or physically admixed catalysts.
Electric birefringence of restriction enzyme fragments of DNA: Optical factor and electric polarizability as a function of molecular weight

The electric birefringence of restriction enzyme fragments of DNA has been investigated as a function of DNA concentration, buffer concentration, and molecular weight, covering a molecular weight range from 80 to 4364 base pairs (bp) (6 × 104–3 × 106 daltons). The specific birefringence of the DNA fragments is independent of DNA concentration below 20 μg DNA/ml, but decreases with increasing buffer concentration, or conductivity, of the solvent. At sufficiently low field strengths, the Kerr law is obeyed for all fragments. The electric field at which the Kerr law ends is inversely proportional to molecular weight. In the Kerr law region the rise of the birefringence is accurately symmetrical with the decay for fragments ≤ 389 bp, indicating an induced dipole orientation mechanism. The optical factor calculated from a 1/E extrapolation of the high field birefringence data is −0.028, independent of molecular weight; if a 1/E2 extrapolation is used, the optical factor is −0.023. The induced polarizability, calculated from the Kerr constant and the optical factor, is proportional to the square of the length of the DNA fragments, and inversely proportional to temperature. Saturation curves for DNA fragments ≤ 161 bp can be described by theoretical saturation curves for induced dipole orientation. The saturation curves of larger fragments are broadened, because of a polarization term which is approximately linear in E, possibly related to the saturation of the induced dipole in high electric fields. This “saturated induced dipole” is found to be 6400 D, independent of molecular weight. The melting temperature of a 216-bp sample is decreased 6°C in an electric field of 8 kV/cm, because the lower charge density of the coil form of DNA makes it more stable in an electric field than the helix form.
Determining the Profile of a Nonmonotonic Hill

In a well-known generalization of the tautochrone problem, the shape of a monotone hill is determined by observing the travel time of a particle on the surface of the hill. In this paper we present a technique for uniquely determining the shape of any smooth hill, whether monotone or not, by observing collisions of particles on the hill. It is shown that this inverse problem is well posed. Error bounds for the solution are given for the case in which there are incomplete data. The efficiency of these bounds is shown by means of an example.
Antagonism of diazepam's anticonflict effects in rats by nicotine, but not by arecoline

The purpose of the present study was to determine the possible role of cholinergic mechanisms in the anticonflict effects of the anxiolytic diazepam. Male Sprague-Dawley rats were tested with a modified Geller-Seifter procedure using a multiple reinforcement schedule in which unpunished responding in one component was reinforced according to a fixed-interval 60-sec schedule, and punished responding in the other component resulted in both food and a brief electric shock presentation according to a fixed-ratio 1 schedule. In Experiment 1 (−)-nicotine antagonized the increase in punished responding that was produced by diazepam. In Experiment 2 diazepam produced selective increases in punished responding that again was antagonized by (−)-nicotine, a nicotinic cholinergic agonist, whereas arecoline, a muscarinic cholinergic agonist, did not antagonize diazepam's increase in punished responding. Neither drug produced any significant changes in unpunished responding. In Experiment 3 it was shown that the centrally acting nicotinic antagonist, mecamylamine, was able to block nicotine's antagonism of diazepam. These results suggest that there is an interaction between central nicotinic cholinergic mechanisms and diazepam's anticonflict effects in this animal model for anxiolytics, and support clinical observations that smoking can reduce some effects of benzodiazepines. © 1994 Wiley-Liss, Inc.
Diversion and abuse of buprenorphine: findings from national surveys of treatment patients and physicians.

Abstract Background Since 2003, buprenorphine has been approved for the treatment of opioid dependence in office-based practice. Diversion and abuse can be a threat to its continued approval under these conditions. Methods As part of a national postmarketing surveillance program, applicants to substance abuse treatment and physicians certified to prescribe buprenorphine were surveyed about their perceptions of buprenorphine/naloxone diversion and abuse. These surveys were supplemented by information from national databases. Availability of buprenorphine/naloxone was measured by number of tablets dispensed. Results Measures of diversion and abuse of buprenorphine/naloxone increased from 2005 to 2009. The results from the applicant survey showed that the perceptions of the extent of diversion and abuse were lower than positive controls, methadone, oxycodone and heroin, but higher than the negative control, amitriptyline. By 2009, 46% of the physicians believed that buprenorphine/naloxone was diverted but 44% believed illegal use was for self-management of withdrawal and 53% believed the source of the medication was substance abuse patients. Other measures from national databases showed similar results. When adjusted for millions of tablets sold per year, slopes for measures of diversion and abuse were reduced. Conclusions The increases in diversion and abuse measures indicate the need to take active attempts to curb diversion and abuse as well as continuous monitoring and surveillance of all buprenorphine products. However, these increases parallel the increased number of tablets sold. Finding a balance of risk/benefit (i.e. diversion and abuse versus expanded treatment) remains a challenge.
Structure and evolution of neurexin genes: insight into the mechanism of alternative splicing.

Neurexins are neuron-specific vertebrate proteins with hundreds of differentially spliced isoforms that may function in synapse organization. We now show that Drosophila melanogaster and Caenorhabditis elegans express a single gene encoding only an α-neurexin, whereas humans and mice express three genes, each of which encodes α- and β-neurexins transcribed from separate promoters. The neurexin genes are very large (up to 1.62 Mb), with the neurexin-3 gene occupying almost 2% of human chromosome 14. Although invertebrate and vertebrate neurexins exhibit a high degree of evolutionary conservation, only vertebrate neurexins are subject to extensive alternative splicing that uses mechanisms ranging from strings of mini-exons to multiple alternative splice donor and acceptor sites. Consistent with their proposed role in synapse specification, neurexins thus have evolved from relatively simple genes in invertebrates to diversified genes in vertebrates with multiple promoters and extensive alternative splicing.
Elasticity of the Lipid Bilayer Edge. Trends in Line Tension

The line tension or excess free energy per unit length of a bilayer edge is an essential measure of the toughness of a lipid bilayer and its ability to support nanoscopic pores. Well-converged values for the line tension of model pure lipid bilayer edges are important for evaluation of the tendency of additives to stabilize or destabilize the edge. Experimental measurements of bilayer edge line tension are challenging, and new approaches are still under development. In this study we report trends for line tensions and microscopic details of the lipid bilayer edge from a series of atomistic simulations of phosphatidylcholine lipids with varying degree of saturation and tail lengths. The simulation line tensions we obtain are higher than those reported from experiments. The choice of force-field on the resulting ribbon properties was investigated and found to not affect the results. The energetics of edge formation as an area expansion perturbation to the bilayer state was also explored and explains the simulation line tensions within a factor of two.
A resistometric determination of the diffusivity of hydrogen in niobium

Abstract The diffusivity of hydrogen in niobium was determined resistometrically between 200 and 350 K. Details of the experiment and computation allowed absolute values of D to be obtained directly. These values are in excellent agreement with those indicated by the Gorsky effect as measured in other laboratories, e.g., D ∼- 8 × 10−6cm2s−1 at room temperature. Increased precision and/or increased temperature range would be required to confirm or refute a reported change in activation energy for hydrogen diffusion. At present, it may be that neither of these increases can be achieved with this resistometric technique.
Literature and Knowledge

There is probably no subject in the philosophy of art which has prompted more impassioned theorizing than the question of the ‘cognitive value’ of works of art. ‘In the end’, one influential critic has stated, ‘I do not distinguish between science and art except as regards method. Both provide us with a view of reality and both are indispensable to a complete understanding of the universe.’ If a man is not prepared to distinguish between science and art one may well wonder what he is prepared to distinguish between, but in all fairness it should be pointed out that the writings of anti-cognitivists contain equally strenuous statements of doctrine. For I. A. Richards, poetry consists of ‘pseudo-statements’ which are ‘true’ if they ‘suit and serve some attitude or link together attitudes which on other grounds are desirable’.
T- and B-Cell Abnormalities in Systemic Lupus

A wealth of T- and B-cell abnormalities has been described in systemic lupus erythematosus (SLE). In general, Tand B cells manifest evidence of intense in vivo activation, yet perform poorly when tested for in vitro responsiveness to exogenous antigen. The immune system behaves as if its commitment to self-responsiveness overrides the normal capacity to respond to immunogenic challenges. Many irnmunoregulatory abnormalities have been characterized, but their relation to disease remains controversial. Although a widely accepted unifying hypothesis for the vigorous autoantibody production and associated immune deficiency of SLE is lacking, it seems certain that the profound abnormalities of T and B cells in SLE are intertwined with the fundamental cause of this illness.
Health Risks, Chronic Diseases, and Access to Care Among US Pacific Islanders

BACKGROUND Because Pacific Islanders and Asian Americans have often been aggregated in federal health surveys, we assessed whether they differ substantially in important health measures.
CURING SACCHAROMYCES CEREVISIAE OF THE 2 MICRON PLASMID BY TARGETED DNA DAMAGE

Powerful mutagenic screens of yeast Saccharomyces cerevisiae have recently been developed which require strains that lack the endogenous 2 micron plasmid (Burns et al., 1994). Here, we describe a simple and reliable method for curing yeast of the highly stable genetic element. The approach employs heterologous expression of a ‘step-arrest’ mutant of the Flp recombinase. The mutant, Flp H305L (Parsons et al., 1988), forms long-lived covalent protein–DNA complexes exclusively at 2 micron-borne recombinase target sites. In vivo, the complexes serve as sites of targeted DNA damage. Using Southern hybridization and a colony color assay for plasmid loss, we show that expression of the mutant enzyme results in the effective elimination of the 2 micron from cells. © 1998 John Wiley & Sons, Ltd.
Neonatal 6-hydroxydopamine alters olfactory development.

The odor preferences and brain catecholamine content of Sprague-Dawley rat pups 5–16 days of age were monitored following systemic injections of 6-hydroxydopamine (6-OHDA) on Days 0–3 postpartum. During the first postnatal week, 6-OHDA produced an alteration in the development of olfactory-guided behavior which was confined to conspecific odor. This deficit did not reflect changes in general sensory or motor capabilities, as both control and treated pups reliably avoided the nonconspecific scents of lemon and cedar. The emergence of preference for nest shaving odor on Day 8 represented an underlying developmental change in the pup rather than changes in the concentration of the odorant in nest shavings. Changes in norepinephrine (NE) concentrations in rostral olfactory structures which paralleled changes in responses to conspecific odorant may underlie the observed behavioral recovery. The involvement of other brain areas innervated by the lateral olfactory tract in the development of odor-guided behavior is also discussed.
Perfect spline approximation

Our study of perfect spline approximation reveals: (i) it is closely related to ΣΔ modulation used in one-bit quantization of bandlimited signals. In fact, they share the same recursive formulae, although in different contexts; (ii) the best rate of approximation by perfect splines of order r with equidistant knots of mesh size h is hr-1. This rate is optimal in the sense that a function can be approximated with a better rate if and only if it is a polynomial of degree < r.The uniqueness of best approximation is studied, too. Along the way, we also give a result on an extremal problem, that is, among all perfect splines with integer knots on R, (multiples of) Euler splines have the smallest possible norms.
On the Probabilistic Zeta Function for Finite Groups

Abstract Let G be a finite group, and define the function[formula]where μ is the Mobius function on the subgroup lattice of G . The function P ( G , s ) is the multiplicative inverse of a zeta function for G , as described by Mann and Boston. Boston conjectured that P ′( G , 1) = 0 if G is a nonabelian simple. We will prove a generalization of this conjecture, showing that P ′( G , 1) = 0 unless G / O p ( G ) is cyclic for some prime p .