cssi/SciSciGPT-SciSciNet huggingface dataset:
The transient energy function method

Abstract The status of the transient energy function (TEF) method of direct analysis of transient stability of power systems is reviewed. The mathematical model is presented; an elementary theoretical basis of the method is introduced; the procedure for using the method in assessing power system transient stability is outlined; and the present condition of the technique and the available computer program is given. The outstanding issues, current development work and new applications are then summarized.
Large eddy simulation in pebble bed gas cooled core reactors

A high temperature gas-cooled reactor (HTGR) is one of the renewed reactor designs to play a role in nuclear power generation. This reactor design concept is currently under consideration and development worldwide. The combination of coated particle fuel, inert helium gas as coolant and graphite moderated reactor makes possible to operate at high temperature yielding a high efficiency. In this study the simulation of turbulent transport for the gas through the gaps of the spherical fuel elements (fuel pebbles) was performed using the large eddy simulation. This would help in understanding the highly three-dimensional, complex flow phenomena caused by flow curvature in the pebble bed. Resolving all the scales of a turbulent flow is too costly, while employing highly empirical turbulence models to complex problems could give inaccurate simulation results. The large eddy simulation (LES) method would overcome these shortcomings. An attempt to obtain experimental velocity flow patterns using particle image velocimetry technique combined with matched refractive index liquid was pursued.
Lectin in five soybean cultivars previously considered to be lectin-negative.

Hemagglutinating proteins were isolated by affinity chromatography from seeds of each of five cultivars of soybeans (Clycine max (L.) Merr.) previously reported to lack detectable lectin (S.P. Pull et al., 1978; Science 200, 1277). Quantities were between 1,000 and 10,000 times less than that found in the seeds of the reference cultivar, Chippewa. The sensitivity of the hemagglutinating assay was 0.05 μg ml-1. Hemagglutinating activity was demonstrated in affinity-purified fractions from bulk seeds and seeds from individual plants in two cultivars, 30–70% ammonium-sulfate-precipitable fractions of seeds from individual plants of all five cultivars, and in whole crude extracts of individual seeds from each cultivar. In all instances, hemagglutinating activity was inhibited by galactose, anti-soybean agglutinin (SBA), and lectin-binding polysaccharide produced by Rhizobium japonicum. Affinity-purified lectin from seeds of a single Columbia plant was labeled with fluorescein isothiocyanate (FITC) and observed by fluorescence microscopy to bind to R. japonicum cells with specificity, intensity and localization indistinguishable from FITC-SBA. Lectins from distinguishable from FITC-SBA. Lectins from three cultivars in sufficiently high concentration for study had molecular properties very similar to Chippewa SBA.
A pulsed fast-thermal neutron system for the detection of hidden explosives

Abstract It has been shown that for all known explosives a strong correlation exists between their O and N concentrations. C is the third element that is also common to all explosives. A system, therefore, that would be able to identify and quantify all three elements, would provide more reliable information about the interrogated material. A pulsed fast-thermal neutron system is used for the simultaneous identification of C, N, and O. Data from explosive simulants indicate the feasibility of the method. The response of various types of γ-ray detectors to the large neutron flux is discussed.
Dynamic Selection Effects in Means-Tested, Urban School Voucher Programs.

Much of the controversy surrounding school vouchers, and privatization schemes generally, stems from concerns about social stratification. This paper identifies the form and magnitude of selection effects in a means-tested New York City voucher program. It compares students who applied for vouchers, with the eligible population of public-school students; those who initially used vouchers, with those who declined them; and those who remained in private schools, with those who eventually returned to public schools. Differences along the lines of ethnicity, residential mobility, mother's education, and income are observed. In addition, specific aspects of a child's education—parental satisfaction, school uniform requirements, and larger class sizes—all increased the length of time voucher students remained in private schools. Throughout the program's life span, however, the largest and most consistent effects revolved around families' religious identity and practices. © 2004 by the Association for Public Policy Analysis and Management.
Speciation of methyltin and butyltin compounds in eelgrass (Zostera marina L.) leaf tissue from the great bay estuary (NH)

Abstract An analytical procedure for extraction of methyl- and butyltin compounds from eelgrass leaf tissue and their determination by a sensitive hydride generation-atomic absorption method is given. A 6 M HCl solution effectively extracts methyltin, and mono- and dibutyltin compounds, but tributyltin requires 2/1 (v/v) dichloromethane-methanol for efficient extraction. Hydride formation of all compounds by sodium borohydride in aqueous media is effective except for tributyltin which requires use of tetrabutylammonium borohydride in dichloromethane. Determinations of methyl- and butyltin compounds in eelgrass samples from the Great Bay Estuary (NH) demonstrate that, at the time of sampling (October, 1987), tributyltin pollution was minimal in this well-mixed estuarine system. Results from a mesocosm polluted with dibutyltin suggest that determination of butyltin compounds in seagrass tissue could be a sensitive means of detecting their presence in the aquatic environment, and could be used to monitor butyltin pollution.
Reaction of uric acid and 3-N-ribosyluric acid with 1,1-diphenyl-2-picrylhydrazyl

Abstract Antioxidants can be assayed by their reaction with 1,1-diphenyl-2-picrylhydrazyl (DPPH), which results in a decrease in absorbance at 517 nm of the DPPH. Both uric acid and 3-ribosyluric acid reacted with DPPH to produce about the same change in absorbance at 517 nm as an equal concentration of ascorbic acid. Fourteen related purines, pyrimidines, and their nucleosides, including xanthine and xanthosine, failed to give a reaction with DPPH at the same concentration as the urates or at 10 times this concentration. When DPPH interacted with [2- 14 C]uric acid, it was converted to allantoin. Cold trichloroacetic acid extracts of bovine blood contained two major compounds that reacted with DPPH, ribosyluric acid and glutathione. These compounds were found only in the red cells and not in the plasma.
Nitric Oxide is a Mediator of Neurogenic Vascular Exudation in the Nose

Rhinorrhea is a troublesome symptom of rhinitis seen commonly by otolaryngologists. The sources of nasal fluid production are glandular secretions and exudation from submucosal blood vessels. This study was designed to investigate the role of nitric oxide in neurogenically mediated vascular exudation in the nose. A rat model of the nasonasal reflex was developed in which one nasal cavity was challenged with histamine while albumin exudation was measured on the contralateral side. Histamine challenge was associated with a significant rise in albumin leakage, indicating an increase in vascular permeability. Perfusion with a nitric oxide synthase inhibitor (N-nitro-L-arginine methyl ester (L-NAME)) in the nasal cavity contralateral to nasal challenge was found to block albumin exudation on that side. This inhibition was overcome by the addition of L-arginine, the natural substrate of nitric oxide synthase, to the perfusate. Treatment of the ipsilateral nasal cavity with L-NAME did not significantly decrease the contralateral response. These findings indicate that NO is an important mediator of the effector arm of the nasonasal reflex that increases vascular permeability but is not involved in the sensory nerve afferent pathway. Further elucidation of the role of NO in nasal physiology may lead to novel pharmacotherapeutic approaches to the treatment of allergic and nonallergic rhinorrhea.
Radiographic appearances following surgical correction of the partially fused epiphyseal plate

Surgical correction of partial post-traumatic fusion of an epiphyseal plate by resection of the bony bridge across the plate and replacement of the bridge by a fat implant causes a characteristic radiographic appearance which is illustrated by two patients and an animal model. Failure to recognize this characteristic postoperative pattern may lead to a misdiagnosis of infection or other bone pathology.
Polyphosphate and Its Diverse Functions in Host Cells and Pathogens

Polyphosphate (polyP) is a linear polymer of a few to many hundreds of phosphate (Pi) residues linked by high-energy phosphoanhydride bonds (Figure 1A). This ubiquitous polymer is found in bacteria, protists, and mammalian cells, and it was likely present prebiotically [1]. In bacteria, polyP accumulates in volutin or metachromatic granules, which are equivalent to acidocalcisomes [2]. In eukaryotic cells, polyP is present in different compartments, including the cytosol, nucleus, lysosomes, and mitochondria, but is preferentially accumulated in acidic vacuoles such as the yeast vacuole and acidocalcisomes [1], [3]. In these organelles, polyP, which is negatively charged, is in close association of inorganic (Ca2+, Mg2+, Zn2+, Fe2+, Na+, K+) and organic (basic amino acids, polyamines) cations. PolyP also combines with calcium and polyhydroxybutyrate forming channels in bacterial membranes, which make them competent for DNA entry; in mitochondria, as part of the mitochondrial permeability transition pore; and in the plasma membrane, as part of the potassium channel and the calcium pump (reviewed in [1], [4]). PolyP is arbitrarily divided into two forms: short-chain (from 3 to ∼300 Pi) and long-chain (from 300 to ∼1000 Pi) polyP, based on the method used for its extraction. For the detection of polyP, several methods have been described and a few examples are shown in Figure 1B–F. Figure 1 Methods used to detect polyP in cells.
Real-Time Characterization of Damage Growth in Graphite/Epoxy Laminates:

The damage growth and failure mechanism in graphite/epoxy composite specimens were characterized by using a modified X-ray nondestructive evaluation (NDE) technique. The NDE monitoring was conducted in real- time while the fracture specimens were under tensile ramp loading and constant amplitude cyclic loading. Tetrabromoethane (TBE) was applied as an opaque additive at the tips of a slit in the center of the specimens to enhance the flaw image. Damage initiation, growth and failure mechanism were observed from sequences of X-ray pictures recorded during testing. Limited results indicated that matrix failure appeared to precede delamina tion between plies in the failure mechanism study. The NDE technique allowed the actual stress redistributions in the composite laminates to be observed.
The accuracy of dual-arch impressions: a pilot study.

Abstract Statement of Problem. Dual-arch impression trays often are used for addition silicone final impressions of fixed prosthodontic preparations, but concerns about distortion of the impression are common because such trays lack rigidity. Purpose. This in vitro pilot study was designed to determine the accuracy of addition silicone impressions made with custom trays or made with either passive or stressed dual-arch trays. Material and Methods. Complete crown preparations of a mandibular molar, premolar, and incisor were made on a dentoform. These tooth preparations received flat, parallel indexes on the facial and lingual axial walls for accurate and reproducible positioning of a digital caliper. Gypsum dies were produced with an addition silicone impression material in either custom trays or dual-arch trays seated passively or with induced flexure (3 dies per tray group). The facio-lingual dimensions of the dies were measured with a digital caliper accurate to ±5 μm and compared to the dimensions of the original preparations. Flexure in the latter group was induced by contact of the tray with a simulated torus, made of resin, in the lingual vestibule of the dentoform. Data were analyzed with 2-way analysis of variance and Tukey's multiple comparison test (α=.05). Results. Dies fabricated with either the custom or passive dual-arch tray reproduced the facio-lingual dimensions of the preparations within a −27 to +13 μm range. Dies fabricated with the flexed dual-arch tray exhibited greater discrepancy, in the range of −47 to −67 μm relative to the preparations. Tray type was a significant factor ( P =.002): the flexed tray group was significantly different than the other 2 groups, which did not differ from each other. Conclusion. Within the limitations of this pilot study, dual-arch impressions were comparable in accuracy to impressions made with custom trays. Accuracy was reduced, however, when the trays were flexed during closure of the arches. (J Prosthet Dent 2002;87:625-7.)
A Faster Execution Algorithm for Dynamically Controllable STNUs

A Simple Temporal Network with Uncertainty (STNU) is a data structure for representing and reasoning about temporal constraints where the durations of certain temporal intervals-the contingent links-are only discovered during execution. The most important property of anSTNU is whether it is dynamically controllable (DC)-that is, whether there exists a strategy for executing time-points that will guarantee that all constraints will be satisfied no matter how the durations of the contingent links turn out. The fastest DC-checking algorithm reported so far is the O(N4)-time algorithm due to Morris (2006). Huns Berger (2010) presented an O(N4)-time execution algorithm for dynamically controllable STNUs, the fastest reported so far. This paper improves upon that algorithm, presenting an O(N3)-time execution algorithm for DC STNUs. The increase in speed is due to more efficient management of the so-called ``wait'' constraints, which must be removed from the network whenever the corresponding contingent link completes.
Mobility characterization of waxy corn starch using wide-line 1H nuclear magnetic resonance

The molecular mobility of waxy corn starch was studied by using wide-line (1)H nuclear magnetic resonance (NMR) spectroscopy. A suite of NMR techniques was used to measure relaxation times (i.e., T(2), T(2), and T(1)) and to characterize water and solid (starch) mobility of waxy corn starch. It was observed that the spectrum of each sample includes a complex broad proton component upon which is superimposed a narrow proton component over water activity (a(w)) ranges from 0.33 to 0.97 (i.e., 10.-25.6% water content) at 25 degrees C. Line shape analysis and relaxation times of both broad and narrow components show that T(2) and T(2) values decrease (i.e., decreasing mobility) with increasing solid concentration and show a "break point" in a concentration range between 19.8 and 21.9% water content. The T(1) shows a "T(1) minimum" in the same concentration range. Starch samples change from the glassy to viscous rubbery state in this same concentration range. This demonstrates that wide-line (1)H NMR relaxation times (i.e., T(2), T(2), and T(1)) may be useful as indicators of glass transition for starch samples in the solid state. The results demonstrate that wide-line (1)H NMR spectroscopy is able to separate modes and quantitate the magnitude of molecular mobility in complex systems.
A hierarchical analysis methodology for chip-level power delivery with realizable model reduction

In this paper, we propose a novel hierarchical analysis methodology to facilitate efficient chip-level power fluctuation analysis. With extreme efficiency and simplicity, our design methodology first builds time-varying multiport Norton equivalent circuits in a row-by-row or block-by-block basis, followed by global analysis of the integrated reduced models. After generating the Norton equivalent sources at external ports, we apply realizable model order reduction technologies to further reduce the model. Since the elements of our reduced model are also RC devices, they are fully compatible with general circuit simulation engines. The experimental results demonstrate more than 4/spl times/ speed up with the flat simulation while maintaining within 5% accuracy.
Desmitificación del inmigrante alemán en Don Helmuth, el colono de Carlos Fuenzalida Valdivia

The novel Don Helmuth, the colonist (1960) follows the criollista model to treat the subject of German colonization in southern Chile. Although it was publis...
Molecular analysis of the t(8;14)(q24;q11) chromosomal breakpoint junctions in the T-cell leukemia line MOLT-16.

The MOLT-16 cell line was established from the leukemic cells of a patient with T-cell acute lymphoblastic leukemia and contains a t(8;14)(q24;q11) resulting in juxtaposition of sequences downstream of the MYC gene on chromosome 8 and the J region of the T-cell receptor alpha chain gene (TCRA) on chromosome 14. The reciprocal translocation involved a complex rearrangement with two chromosome breakpoints within the TCRA J region on chromosome 14, resulting in inversion of a 1.4 kb DNA fragment between the two breakpoints. The 5′ border of the inversion joins with another segment of chromosome 14, whereas the 3′ border joins with a region of chromosome 8 located at least 257 kb downstream of MYC. Extensive deletions have occurred on both chromosomes 8 and 14 in conjunction with the translocation. To investigate the possible involvement of the V(D)J recombinase in this translocation, we analyzed the nucleotide sequences surrounding the translocation breakpoints. The breakpoint on chromosome 14 occurs between a segment coding for a TCRA J sequence and its heptamer-nonamer signal. Heptamer-nonamer consensus sequences are also identified on chromosome 8 adjacent to the breakpoint. Inserted N and P nucleotides are observed at the breakpoint junctions. Genes Chromosomes Cancer 20:363–371, 1997. © 1997 Wiley-Liss, Inc.
Speaker adaptation with an Exponential Transform

In this paper we describe a linear transform that we call an Exponential Transform (ET), which integrates aspects of CMLLR, VTLN and STC/MLLT into a single transform with jointly trained components. Its main advantage is that a very small number of speaker-specific parameters is required, thus enabling effective adaptation with small amounts of speaker specific data. Our formulation shares some characteristics of Vocal Tract Length Normalization (VTLN), and is intended as a substitute for VTLN. The key part of the transform is controlled by a single speaker-specific parameter that is analogous to a VTLN warp factor. The transform has non-speaker-specific parameters that are learned from data, and we find that the axis along which male and female speakers differ is automatically learned. The exponential transform has no explicit notion of frequency warping, which makes it applicable in principle to non-standard features such as those derived from neural nets, or when the key axes may not be male-female. Based on our experiments with standard MFCC features, it appears to perform better than conventional VTLN.
Semantic Social Network Analysis for Trend Identification

This paper considers the extraction and analysis of Social Networks for the identification of trends. Our methodology focuses on the utilization of semantics for determination of relevant networks within unstructured data. The Social Networks are examined from the perspective of structure and considered as a time series. Our metrics focus on the identification of influence and power among key players. This method is applied against a collection of Twitter messages and compared to historical market share trends of technologically-related topics. Through this work we demonstrate that structural qualities reflecting community dynamics can provide insight to the prediction of long-term trends. The goal of this work is to lend insight to the characterization of consumer behavior, particularly in the area of technology forecasting.
Exchange‐rate volatility and US–Hong Kong industry trade: is there evidence of a ‘third country’ effect?

In an effort to better understand the determinants of trade flows worldwide, researchers have recently incorporated external volatility (in addition to that of the partners’ bilateral exchange rate) into their models. The so‐called ‘third country’ effect is present if adding this term changes the bilateral volatility estimates that are found when external volatility is omitted. This study examines US exports to Hong Kong for 143 industries, and imports from Hong Kong for 110 industries, and finds two key results. First, expected inflation due to Hong Kong's dollar peg leads to increased US exports in a large number of industries. Second, comparing our results with those of a previous study shows strong evidence of a ‘third country’ effect, especially for US imports. Nonparametric tests suggest that these effects differ by sector: for both exports and imports. Manufacturing industries that enjoy a large trade share are less likely to experience this effect once external volatility is incorporated into the ...
Whole-body autoradiography of 14C sodium cyclamate in pregnant and fetal rats

Abstract Whole-body autoradiography demonstrates that 14C sodium cyclamate is present in all maternal tissues within 5 min after iv administration with little or no radioactivity present in fetal tissues. By 7 hr radioactivity is largely absent from the mother while the fetus retains the cyclamate for longer periods of time.
COAL-FUELED GAS TURBINE PROGRAM

The U.S. Department of Energy has initiated a program to stimulate the development of integrated coal-fueled gas turbine systems for generation of low-cost electric power. This paper describes the rationale and elements contained in this program. The incentives for the (DOE) coal-fueled gas turbine program are a perceived need for modular, low-cost electric generating capacity for the mid-to-late 1990's, which will not increase the consumption of oil and the need for a low-cost option to long lead time conventional electric power generating systems. The coal-fueled gas turbine also offers the potential to repower existing electric generating facilities as well as for industrial cogeneration applications. The primary fuels being considered are coal slurries and coal gasifier fuels under three program elements: basic data studies, systems and economic studies, and component/system development. The basic data element is designed to address needed information on the effects of the coal and coal-derived combustion contaminants on turbine components. Basic combustion phenomena tests are being carried out by the Morgantown Energy Technology Center and by various industrial organizations to accomplish this goal. The systems and economic studies element of the program is an ongoing effort to provide program assessment and direction. Several major equipment manufacturers aremore » parametrically examining various system configurations and fuel quality to determine process and economic implications. The component development element of the program is planned to start in 1984.« less
Vote Visibility, Roll Call Participation, and Strategic Absenteeism in the U.S. House

Absenteeism on roll call votes in the U.S. House decreased just prior to events of the early 1970s, thus suggesting that the two events are related. Changes during the early 1970s increased the number, the visibility and the pubic accessibility of recorded legislator's decisions. With relevant political actors having easier access to more legislator's decisions, lawmakers have less room to deviate from what they perceive to be the electorally tenable position. While good roll call attendance rates are now the norm, this is even more so in cases of high visibility votes, i.e., conflictual votes and votes of stated presidential concern. Nonetheless, the use of strategic absenteeism by politically conflicted, southern Democrats seems to endure.
Orientation determination and morphological study of high density polyethylene (HDPE) extruded tubular films: effect of processing variables and molecular weight distribution

Abstract The structure—property behaviour of high density polyethylene (HDPE) extruded tubular films having a blow up ratio of unity was investigated. Two different HDPE resins with identical M n (14 600 g/mol) values but different distributions ( M w M n = 10.3, 15.1 ) were utilized in this extrusion process. Systematic changes were also made in the process variables—these being the melt temperature at the die exit, the quench height, which is the distance from the exit of the die to the cooling ring, the flow rate of the air through the cooling ring, and the film line speed. The morphological features and state of orientation of the extruded tubular films were examined by transmission electron microscopy (TEM), high resolution scanning electron microscopy (HSEM), birefringence, wide and small angle X-ray scattering studies (WAXS, SAXS), and linear infra-red (i.r.) dichroism. A stacked lamellar or, in some cases, a fibril nucleated morphology was observed in the melt-extruded films by TEM. This technique clearly showed that the broader molecular weight samples possessed fibril nuclei that were not evident in the narrower molecular weight distribution films. The existence of the fibril nuclei was further confirmed from WAXS by the intense sharp spots superimposed on the equatorial (110), (200), and (020) reflections. The origin of this pronounced fibril nucleation was clearly believed to be due to the longer relaxation time behaviour of the broader distribution resin. The amorphous phase orientation and form birefringence for all films were found to be very small, and the observed birefringence arose almost exclusively from the crystalline phase. It was also found that the morphology and the orientation of the chain axis in the crystalline phase were particularly sensitive to the quench height and melt temperature for the narrower distribution HDPE films, but much less so for the broader distribution HDPE samples. Little dependence of structure/orientation was noted for either resin for the variables of the flow rate of the air through the cooling ring and the film line speed. These findings show the sensitivity of the molecular weight distribution to be a very important parameter, as are the specific processing variables of quench height and melt temperature, in determining the final solid state structure of the HDPE extruded tubular films.
Strontium isotope and alkali element geochemistry of selected sediments from the northeast Pacific Ocean

Abstract Few chemical and isotopic data exist for bulk samples of ocean basin clays. Such data are necessary to evaluate subduction models for the genesis of calc-alkaline rocks. The northeast Pacific Ocean provides a locale in which one can evaluate the possible chemical effects of both oceanic volcanism and continental sedimentation on ocean basin sediments. Sr 87 Sr 86 ratios for these bulk sediment samples vary with the concentration of strontium and range from values near that of marine strontium to more radiogenic values (0.7081-0.7165). Potassium and rubidium concentration data indicate a rather constant K Rb ratio ranging from 350 to 440 with one exception. Variable Rb Sr ratios reflect a mixed mineralogy, also indicated by X-ray diffraction data. Various mixtures of detrital minerals, dominately clays, and carbonate minerals logically explain the variation of the strontium data.
Fiber-coupled nanowire photon counter at 1550 nm with 24% system detection efficiency

We developed a fiber-coupled superconducting nanowire single-photon detector system in a close-cycled cryocooler and achieved 24% and 22% system detection efficiencies at wavelengths of 1550 and 1315 nm, respectively. The maximum dark count rate was approximately 1000 counts/s.
Tryptophanyl fluorescence of sodium dodecyl sulfate treated and 2-mercaptoethanol reduced proteins: a simple assay for tryptophan.

Abstract Relative tryptophanyl fluorescence intensities of eleven different proteins (bovine liver glutamate dehydrogenase, bovine pancreas trypsin and α-chymotrypsinogen, egg white lysozyme, ovalbumin, bovine serum albumin and γ-globulin, bovine heart and rabbit muscle lactate dehydrogenases, rabbit muscle glyceraldehyde-3-phosphate dehydrogenase, and yeast alcohol dehydrogenase) were evaluated as a function of the physical state of the protein, i.e., native, denatured with intact disulfide bonds, and denatured with reduced disulfide bonds. Tryptophanyl fluorescence of these proteins was directly proportional to the tryptophan content of the reduced, detergent-protein complex. Denaturation of proteins by detergent alone, although causing pronounced changes in fluorescence intensity, was unable to provide a common micro-environment for all tryptophan residues. A simple fluorescence assay of tryptophan content in proteins was developed.
FMRI in brain research in its historical context.

When one follows the rapid accumulation of significant contributions to the study of brain function based on functional magnetic resonance imaging (fMRI), it is difficult to remember that all of th...
Mendeleev's chemical ether, electrons, and the atomic theory

Examines Mendeleev's concerns regarding the discovery of the electron and the immutability of elements - both of which Mendeleev saw as sturdy supports of chemical theory.
The violence of spectacle: Statist schemes to green the desert and constructing Astana and Ashgabat as urban oases

Kazakhstan and Turkmenistan have been home to the most impressive urban development projects in the entire post-Soviet world. Their capitals, Astana and Ashgabat, now boast uniquely monumental architecture and local leaders have invested heavily in ‘green belt’ projects to surround the cities with lush vegetation, as well as developing green and water-laden public spaces. In doing so, elites have drawn on Soviet-era ‘garden city’ idealism, as well as more recent environmental sustainability narratives. Yet these schemes are anything but sustainable. Unfolding on the arid Central Asian steppe, they depend on heavy irrigation, with water diverted from rivers that already fail to meet regional demands. Employing a comparative approach, I ask why and with what effect state planners have sought to craft Astana and Ashgabat as spectacularly green ‘urban oases,’ when their local climates should defy the logic of sustainability. In so doing, I consider urban greening in the two countries as part of a wider phenom...
Experimental Investigation of Separated Nozzle Flows

A detailed experimental study of separated nozzle flows has been conducted at the NASA Langley Research Center 16-Foot Transonic Tunnel Complex. As part of a comprehensive static performance investigation, force, moment, and pressure measurements were made and schlieren flow visualization was obtained for a subscale, nonaxisymmetric, two-dimensional, convergent-divergent nozzle. For reference, experimental results were compared with theoretical predictions based on one-dimensional gasdynamics and an approximate integral momentum boundary-layer method. Results from this study indicate that overexpanded nozzle flow was dominated by shock-induced boundary-layer separation, which was divided into two distinct flow regimes: three-dimensional separation with partial reattachment and fully detached two-dimensional separation. The test nozzle was observed to go through a marked transition in passing from one regime to the other. In all cases, separation provided a significant increase in static thrust efficiency compared to the ideal prediction. Results suggest that, with controlled separation, the entire overexpanded range of nozzle performance would be within 16% of the peak thrust efficiency. By offering savings in weight and complexity over a conventional mechanical variable geometry exhaust system, a fixed geometry nozzle may be able to cover an entire flight envelope in some applications.
Multi-area state estimation using distributed SDP for nonlinear power systems

State estimation (SE) is an important task allowing power networks to monitor accurately the underlying system state, while multi-area SE is becoming increasingly popular as the power grid comprises multiple interconnected “subgrids.” For nonlinear AC power systems, SE per subgrid amounts to minimizing a nonlinear least-squares cost that is inherently nonconvex, thus giving rise to many local optima. Despite the non-convexity, a recent SE approach based on semidefinite programming (SDP) has been effective in approaching globally optimal performance at the price of higher computational cost. A novel reduced-complexity algorithm is developed in this paper for local control areas to solve the centralized SDP-based SE problem in a distributed fashion. It leverages results on positive semidefinite matrix completion to split a global state matrix constraint into local ones, which further allows for parallel implementation using the alternating-direction method of multipliers (ADMM). With minimal data exchanges among neighboring areas, each control center can efficiently perform local updates that scale with each area's size (number of buses). Numerical simulations using the IEEE 14-bus system demonstrate the asymptotic convergence of local state matrices, and desirable estimation accuracy attainable with a limited number of exchanges.
CO2 Permeability of Polystyrene Nanocomposites and Nanocomposite Foams

Steady state permeability coefficients P of carbon dioxide (CO2) in polystyrene (PS) and PS nanocomposites and their corresponding foams at 0.10 MPa (gauge pressure) and three different temperatures were measured. Permeability coefficients of foams are about 1 order of magnitude higher than those of corresponding plates. Three PS nanocomposites were used: PS + 5% 20A (treated nanoclay provided by Southern Clay), PS + 5% CNFs (carbon nanofibers), and PS + 5% MHABS (nanoclay treated with 2-methacryloyloxyethylhexadecyldimethylammonium bromide). For both plates and foams, the permeability coefficient decreases considerably with addition of nanoparticles. Foam structure is shown to play a more important role than nanoparticles in determining the permeability coefficient values for nanocomposite foams.
Abstract 5158: Differentiation of glioblastoma stem-like cells induced by retinoic acid

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC We investigated the molecular and cellular responses of glioblastoma stem-like cells (GBM-SCs) to all-trans retinoic acid (RA)-induced differentiation. Four GBM-SC lines were used. Under neurosphere culture conditions, GBM-SCs grow as non-adherent neurospheres. RA (10 μmol/l) treatment for 48 h induced cells to adhere to culture surfaces and generate processes. RA inhibited G1/G0 to S transition, decreased cyclin D1 expression (50%) and increased p27 expression (2-fold). Immunofluorescence staining, western blot and flow cytometry analyses showed that RA induced the expression of differentiation markers Tuj1 and GFAP and inhibited nestin expression. RA treatment reduced the number of cells expressing CD133 from 44% to 10%. We measured the effects of RA on neurosphere number and size. RA treatment dramatically decreased (∼90%) the number of neurospheres > 50 um diameter. Clonogenic assay showed that RA reduced the colony formation ability of GBM-SCs in soft agar. Microarray analysis was performed to determine the global gene expression profile of RA-induced GBM-SC differentiation. Data were analyzed using Significance Analysis of Microarrays (SAM) and the false discovery rate was set at 20%. Approximately 350 genes were altered after RA treatment for 48h; ∼20% were down-regulated and 80% were up-regulated. We selected 18 candidates and validated with real-time PCR. All 18 candidates exhibited the same pattern of up- or down-regulation by RA. Western blot analysis for some candidate gene products also confirmed the alteration by RA at the protein level. A web-based (portal.genego.com) molecular pathway analysis of RA-induced gene expression profiling identified several pathways altered during RA-induced differentiation process. The most prominent of them was Notch signaling. Notch pathway members Delta-like 1 (DLL1), Notch 1, NCID, NEXT and Notch 1 precursor were found to be down-regulated by RA. Only Delta-like 4 (DLL4) was up-regulated by RA. We also found that cyclin D, cyclin D1, PP2A and SMAD3, gene products involved in G1-S transition, were down-regulated by RA. This is consistence with our findings that RA induces cell cycle arrest. Numerous mechanisms involved in cell adhesion, cell-matrix interaction and cytoskeleton remodeling were also affected by RA. This analysis provides guidelines to further explore pathways and mechanisms during RA-induced GBM-SC differentiation. Our findings may be applicable to identify new molecular target applicable to differentiation therapies for glioblastomas. This will also stimulate the development of GBM stem cell based pre-clinical experimental models with the potential to improve mechanistic and pre-clinical therapeutic research. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5158.
Regulation of LPA-Promoted Myofibroblast Contraction: Role of Rho, Myosin Light Chain Kinase, and Myosin Light Chain Phosphatase

Myofibroblasts generate the contractile force responsible for wound healing and pathological tissue contracture. In this paper the stress-relaxed collagen lattice model was used to study lysophosphatidic acid (LPA)-promoted myofibroblast contraction and the role of the small GTPase Rho and its downstream targets Rho kinase and myosin light chain phosphatase (MLCPPase) in regulating myofibroblast contraction. In addition, the regulation of myofibroblast contraction was compared with that of smooth muscle cells. LPA-promoted myofibroblast contraction was inhibited by the myosin light chain kinase (MLCK) inhibitors KT5926 and ML-7; however, in contrast to that observed in smooth muscle cells, elevation of intracellular calcium alone was not sufficient to promote myofibroblast contraction. These results suggest that Ca2+-mediated activation of MLCK, while necessary, is not sufficient to promote myofibroblast contraction. The specific Rho inactivator C3-transferase and the Rho kinase inhibitor Y-27632 inhibited LPA-promoted myofibroblast contraction, suggesting that contraction depends on activation of the Rho/Rho kinase pathway. Calyculin, a type 1 phosphatase inhibitor known to inhibit MLCPPase, could promote myofibroblast contraction in the absence of LPA, as well as restore contraction in the presence of C3-transferase or Y-27632. Together these results support a model whereby Rho/Rho kinase-mediated inhibition of MLCPPase is necessary for LPA-promoted myofibroblast contraction, in contrast to smooth muscle cells in which Ca2+ activation of MLCK alone is sufficient to promote contraction.
Prevention of lung cancer: the key is to stop smoking.

Objectives: To review current approaches to primary prevention of lung cancer and to screening for precarcinogenic or preclinical asymptomatic disease. Data sources: Research studies, review articles, and government reports relating to prevention of lung cancer and strategies for smoking cessation. Conclusions: Because almost 90% of lung cancer cases can be attributed to tobacco, reduction of smoking is the appropriate focus of lung cancer prevention efforts. Lung cancer chemoprevention remains an experimental approach and large scale screening for lung cancer is of limited value. Implications for nursing practice: Nurses are in a strategic position to prevent smoking initiation and to influence successful smoking cessation through education, information on the multiple modalities to assist behavioral change, and ongoing reinforcement.
Fracture parameter inversion for Marcellus Shale

ABSTRACTWe inverted P-wave amplitude variation with offset and azimuth (AVOAz) data from the Marcellus Shale to obtain fracture parameters that can fully describe the elastic behavior of fractured rocks with overall symmetry of orthorhombic or monoclinic. AVOAz data from two interfaces, (1) the upper interface between top Marcellus and Stafford limestone and (2) the lower interface between base Marcellus and Onondaga limestone, were used for inversion. To check the validity of our inversion results, fracture parameters for the Marcellus Shale were inverted for each interface using Monte Carlo simulation to include uncertainty in our a priori information, i.e., elastic properties of unfractured rocks that are assumed to be known from well logs. Inversion results appeared robust with respect to uncertainties and converge to the same values for the two inversions. Our results were also consistent with singular value decomposition analysis (resolution matrix).
Concentrations of circulating gonadotropins during various reproductive states in mares.

Concentrations of circulatingFSH and LH were measured in pony and horse mares during the estrous cycle. The gonadotropin profilesdid not differsignificantly between the two types of mares. During the estrous cycle FSH and LH were secreted in a reciprocal pattern with FSH high during diestrus and LH high during estrus. Although the patterns of FSH and progesterone secretion were similar, FSH rose before progesterone at the end of estrus, indicating that the initial FSH increasewas not due to a positive feedback effect of progesterone. The patterns of LH, but not of FSH secretion, diverged between nonpregnant and pregnant mares 19 days after ovulation. In both hysterectomized and pregnant mares, FSH concentrations were elevated after the end of estrus, comparable to what occurred during diestrus. Treatment of diestrous mares with estradiol or of seasonally anovulatory mares with clomiphene citrate had no significant effect on concentrations of circulating FSH or LH.
Considerations in the use of high-pressure size exclusion chromatography (HPSEC) for determining molecular weights of aquatic humic substances

Abstract High-pressure size exclusion chromatography (HPSEC) is a powerful technique for determining molecular weight (MW) distributions of aquatic humic substances (HS). Previous researchers have shown that HPSEC can provide values of weight average molecular weight ( M w ), number average molecular weight ( M n ), and polydispersity ( ρ ) that are comparable to values determined by other techniques such as vapor pressure osmometry and field flow fractionation. We have observed that HPSEC does not always provide reproducible results for HS—variability by 10–20% is common. Since certain applications require better precision for MW of HS, this research focuses on improving precision and reproducibility of HPSEC measurements. While the method of baseline correction or of high MW (HMW) cutoff of the HPSEC chromatogram is not critical, the choice of low MW (LMW) cutoff can greatly affect M n and ρ . For HS, we recommend either 2% of the maximum chromatogram height or MW=50 as the LMW cutoff, whichever is the higher value, and 1% of the maximum chromatogram height as the HMW cutoff. Polystyrene sulfonate (PSS) standards are commonly used in combination with acetone; we further recommend the inclusion of salicylic acid as a charged low MW standard. Analysis of UV detection wavelengths shows that wavelengths between 230 and 280 nm give reasonable results, but that higher wavelengths can bias measurements to higher MWs. We recommend 254 nm except for low carbon concentration samples, where 230 will provide better sensitivity. Our results show that “standardization” of HPSEC procedures according to these suggestions can lead to excellent reproducibility of M n and M w measurements for HS (2–3% RSD).
On the Correct Handling of Contradictions

Kurt London, ed., Unity and Contradiction: Major Aspects of Sino-Soviet Relations, New York, Frederick A. Praeger, Inc., i962, 464 pp. $7.50. Peter S. H. Tang, Communist China Today, Vol. I: Domestic and Foreign Policies, rev. ed., Washington, D.C., Research Institute on the Sino-Soviet Bloc, i96i, 745 pp. $io.oo. R. G. Boyd, Communist China's Foreign Policy, New York, Frederick A. Praeger, Inc., i962, I47 pp. $4.50. Donald S. Zagoria, The Sino-Soviet Conflict, i956-196i, Princeton, N.J., Princeton University Press, i962, 484 pp. $8.5o.
cognitive pluralism or individual differences: a comparison of alternative models of American English kin terms

This paper uses multidimensional scaling (MDS) to compare alternative models of kinship terms of American English. It thereby inquires into whether the same person can operate with alternative cognitive structures when the verbal context of the kinship terms is systematically modified by the presence (as in the Wallace-Atkins model) or the absence (as in the Romney-D'Andrade model) of an ego reference point. Our experiments also demonstrate unexpected discrepencies between the results of similarity tests with dyads and those with triads when the ego reference point is present.
A hybrid procedural/deductive executive for autonomous spacecraft

The New Millennium Remote Agent (NMRA) will be the first AI system to control an actual spacecraft. The spacecraft domain places a strong premium on autonomy and requires dynamic recoveries and robust concurrent execution, all in the presence of tight real-time deadlines, changing goals, scarce resource constraints, and a wide variety of possible failures. To achieve this level of execution robustness, we have integrated a procedural executive based on generic procedures with a deductive model-based executive. A procedural executive provides sophisticated control constructs such as loops, parallel activity, locks, and synchronization which are used for robust schedule execution, hierarchical task decomposition, and routine configuration management. A deductive executive provides algorithms for sophisticated state inference and optimal failure recover), planning. The integrated executive enables designers to code knowledge via a combination of procedures and declarative models, yielding a rich modeling capability suitable to the challenges of real spacecraft control. The interface between the two executives ensures both that recovery sequences are smoothly merged into high-level schedule execution and that a high degree of reactivity is retained to effectively handle additional failures during recovery.
Elderly patients discharged home from the emergency department with minor burns

Abstract Objectives: To describe the risk factors, etiology and referral patterns of elderly patients treated for minor burns in an urban emergency department (ED). Methods: A retrospective chart review was conducted of persons aged 65 years and older who were treated for a minor burn and discharged home from the ED. Medical records were reviewed for 77 burn patients that presented over a 6-year period. Results: Burn patients had significant co-morbid medical illness. The etiology of the burns was scalds (58%), contact (27%) and flame (12%). Sixty-eight percent of the burns were cooking related. Heating pads, curling irons or hot pipes accounted for the majority of contact burns. Three percent of burn patients were referred to a home care agency for a home safety evaluation at the time of discharge from the ED. Conclusion: Cooking-related activities accounted for the majority of minor burns in this series. Common consumer items or environmental hazards were responsible for most contact burns. Elderly patients seen in the ED with minor burns were rarely referred to a home care agency.