cssi/SciSciGPT-SciSciNet huggingface dataset:
Radiofrequency catheter ablation of ventricular tachycardia in children and young adults with congenital heart disease

Objectives The aim of this study was to expand data on outcomes for radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in young patients and to identify obstacles to success. Background Ablation of VT is performed infrequently in young patients. Published experience has been limited to case reports and small descriptive series. Methods A retrospective review of 97 consecutive VT ablation procedures involving 62 patients at a single institution from 1990 to 2003 was undertaken. All intention-to-treat procedures were analyzed. Results Mean age was 13.9 ± 9.4 years. Procedures were categorized according to VT mechanism as follows: idiopathic right ventricle (n = 37); idiopathic left ventricle (n = 24); congenital heart disease (n = 20); or other structural disease (n = 16). Acute success was achieved in 58 (60%) of 97 procedures. Of the 39 failures, 33 were aborted cases due to inability to induce sufficient ectopy for mapping in 12, high-risk location near the His bundle or coronary artery in 11, unstable VT in 7, and anatomic obstacles in 3. Recurrence rate after acutely successful RFCA was 34% (20/58 procedures) at a mean follow-up of 3.8 ± 2.0 years. Ultimately, long-term success was achieved in 38 (61%) of 62 patients after a mean of 1.6 ± 0.9 procedures, with the highest success rate (87%) for idiopathic left ventricular tachycardia. Conclusions When analyzed on a strict intention-to-treat basis, a long-term success rate of 61% is observed with ablation of VT in young patients. Inability to induce stable VT for precision mapping and certain high-risk VT locations can be significant obstacles to success.
A theory for free vibration of orthotropic shells of revolution

Abstract A theory of free vibration for orthotropic shells of revolution including the effects of transverse shear and rotary inertia is formulated. Derived equilibrium equations are expressed in terms of the displacement vector, which is written as a truncated power series expansion in the thickness coordinate. The partition method, in conjunction with piecewise polynomials, is used to obtain a solution. The effect of transverse shear for non-axisymmetric, transverse vibrations of a cylinder and of a torus segment is indicated in several examples. Results show that transverse shear significantly affects the natural frequencies of these shells.
Clinical outcomes of drug-eluting versus bare-metal in-stent restenosis.

In-stent restenosis (ISR) is a challenging syndrome that affects drug-eluting stents and bare-metal stents. However, data comparing the outcomes of drug-eluting versus bare-metal ISR are limited. Our objective was to evaluate the long-term clinical outcomes of drug-eluting versus bare-metal ISR. Patients who underwent percutaneous coronary intervention at Cleveland Clinic for ISR from 05/1999 to 06/2007 were included. Unadjusted outcomes were tested using Kaplan-Meier curves followed by multivariable adjusted Cox proportional hazards analyses. Twenty seven variables, including type of stent used to treat ISR and procedural date, were included. The primary end point was a composite of death, myocardial infarction (MI), or target lesion revascularization (TLR). The secondary endpoints were components of the primary endpoint. Of 931 patients identified, 225 had drug-eluting ISR and 706 had bare-metal ISR. There were 279 cumulative events for a median follow-up of 3.2 years. The primary endpoint was not different between drug eluting and bare-metal ISR (22% versus 33%, adjusted hazard ratio [HR] 1.14; 95% confidence interval [CI], 0.79–1.66; P = 0.49). The secondary endpoints of death (8% versus 16%, adjusted HR 1.05; 95% CI, 0.56–1.98; P = 0.88), MI (4% versus 5%, adjusted HR 1.48; 95% CI, 0.54–4.04; P = 0.45), and TLR (15% versus 16%, adjusted HR 1.30; 95% CI, 0.81–2.11; P = 0.28) were also not different. This study represents the largest analysis comparing drug-eluting to bare-metal ISR. On multivariable Cox proportional hazard analyses, drug-eluting and bare-metal ISR have similar long term outcomes. © 2009 Wiley-Liss, Inc.
Effects of Diabetes Insipidus Mutations on Neurophysin Folding and Function

Mechanisms underlying the pathogenicity of diabetes insipidus mutations were probed by studying their effects on the properties of bovine oxytocin-related neurophysin. The mutations G17V, DeltaE47, G57S, G57R, and C67STOP were each shown to have structural consequences that would diminish the conformational stability and folding efficiency of the precursors in which they were incorporated, and factors contributing to the origins of these property changes were identified. Effects of the mutations on dimerization of the folded proteins were similarly analyzed. The projected relative impact of the above mutations on precursor folding properties qualitatively parallels the reported relative severity of their effects on the biological handling of the human vasopressin precursor, but quantitative differences between thermodynamic effects and biological impact are noted and explored. The sole mutation for which no clear thermodynamic basis was found for its pathogenicity was 87STOP, suggesting that the region of the precursor deleted by this mutation plays a role in targeting independent from effects on folding, or participates in stabilizing interactions unique to the human vasopressin precursor.
Linear properties of eddies in a Jovian troposphere forced by deep jets

A linear quasi-geostrophic beta-plane model is used to study large-scale instabilities of the Jovian upper troposphere forced from below by zonal jets. The jets are presumed to be barotropically stable in the isentropic deep interior, but barotropically unstable in the statically stable upper troposphere. The effect on this barotropic instability of weak vertical shear causing the jets to decay with height is examined. It is found that eastward jets are stabilized by weaker shear than westward jets, the most unstable eddies are strongly confined by the shear, and eddy fluxes contribute to vertical decay of the jets. The lower residual mean meridional circulation cells exhibit rising motion in regions of anticyclonic shear, but these are overlain by reverse cells.
Functional neuroimaging of cortical dysfunction in alcoholic korsakoff's syndrome

Many neuropsychological investigations of human memory have focused on the amnesic deficits of alcoholic Korsakoff's syndrome. Structural neuroimaging suggests that the syndrome results from midline diencephalic damage, but functional neuroimaging has the potential to reveal additional neuropathology that may be responsible for cognitive dysfunction. Accordingly, high-resolution positron emission tomography (PET) was used to measure regional cerebral metabolic rates for glucose utilization in five alcoholic Korsakoff patients and nine alcoholic control subjects. Results from a continuous recognition test administered during the radiotracer uptake period indicated that all subjects performed normally with respect to immediate memory, whereas Korsakoff patients demonstrated a marked memory impairment in delayed recognition. PET results from the Korsakoff group showed a widespread decline in glucose metabolism in frontal, parietal, and cingulate regions, suggesting that these functional abnormalities in the cerebral cortex contribute to the memory impairment. Hippocampal glucose metabolism did not differ between the groups. Thus, the evidence did not support the hypothesis that parallel brain dysfunctions are responsible for the similar amnesic symptomatology after hippocampal and diencephalic damage. We hypothesize that the amnesic dysfunction of Korsakoff's syndrome depends on a disruption of thalamocortical interactions that mediate a function critical for normal memory storage.
Fernando Arrabal's "Ars Amandi": The Theme of Love in Selected Plays

The evolution in Arrabal's treatment of the theme of love reflects both the development and enrichment of his dramatic techniques and the resolution of his own deep-seated psychological conflicts. Arrabal's theater utilizes his concept of dramatic ceremony to project his intense desire for personal, political and artistic liberation. Psychological and social forces combine to frustrate the fulfillment of love in his early theater (Fando and Lis, 1956) but ultimately love functions to obviate both internal and external constraints. Sexual union, which receives its most rapturous affirmation in Arrabal's plays written during the late 1960's (The Law of Barabbas, Ars Amandi, and Erotic Bestiality), reflects the reconciliation of dialectical forces present in man's psyche. Women come to serve as intermediaries between man and the world. And in the broadest sense, the dramatic structure of Arrabal's mature plays can be depicted as the movement from psychic fragmentation to psychic unity, effected by the force of love. This article is available in Studies in 20th Century Literature: http://newprairiepress.org/sttcl/vol2/iss1/6 FERNANDO ARRABAL'S "ARS AMANDI": THE THEME OF LOVE IN SELECTED PLAYS
Identification of Scavenger Receptor SR-BI as a High Density Lipoprotein Receptor

High density lipoprotein (HDL) and low density lipoprotein (LDL) are cholesterol transport particles whose plasma concentrations are directly (LDL) and inversely (HDL) correlated with risk for atherosclerosis. LDL catabolism involves cellular uptake and degradation of the entire particle by a well-characterized receptor. HDL, in contrast, selectively delivers its cholesterol, but not protein, to cells by unknown receptors. Here it is shown that the class B scavenger receptor SR-BI is an HDL receptor. SR-BI binds HDL with high affinity, is expressed primarily in liver and nonplacental steroidogenic tissues, and mediates selective cholesterol uptake by a mechanism distinct from the classic LDL receptor pathway.
Financial Wellness and Relationship Satisfaction: Does Communication Mediate?

This research investigated if married couples' positive and negative communication patterns mediate the association between financial wellness and relationship satisfaction. Data were collected from married individuals in a southern state in 2007 (N = 515) and 2011 (N = 489). Guided by social exchange theory, structural equation models isolated the mediating effects of positive and negative communication patterns. In concert with a consistent and positive direct path from financial wellness to relationship satisfaction, financial wellness was positively associated with positive communication patterns and negatively associated with negative communication patterns. Although a mediating role for positive communication was not identified, negative communication patterns indicated full mediation with the 2007 sample and partial mediation with the 2011 sample. Implications for understanding the effects of finances and couple communication processes on relationship satisfaction are discussed.
A comparison of the learnability of manual sign and Blissymbolics with nonhandicapped adults

Although advocates exist for teaching either Blissymbolics or manual sign to language-impaired students, relatively few empirical data exist on the learnability of the two systems. The present study compared the learning of a list of 20 Blissymbols and comparable ASL signs in a controlled paired-associate (P-A) paradigm. Blissymbols were learned significantly faster than manual sign particularly in early learning trials. Results are discussed in terms of the memory requirements of the two systems and their relationship with sign/symbols learning.
Impact of Consumer Confidence on Purchase Behavior in an Emerging Market

Abstract This study explores the impact of consumer confidence in the future economy on consumer purchase plans regarding a global, frequently purchased good (FPG) in an emerging market. Some studies indicate a significant relationship between consumer confidence in the future economy at the macroeconomic level for specialty and durable product consumption; there is, however, not enough research investigating the aforementioned relationship for FPG. The survey was conducted at the point-of-purchase with satisfactory reliability and validity scores. The Multi-Sample Structural Equation Model was developed for testing the hypotheses of our proposed model for a differently promoted global FPG. The results showed that consumer brand loyalty and promotion propensity often moderate the influence of a consumer's confidence in the future economy on his/her purchase plans. The study's findings indicated that manufacturers need to focus on the retailers' increasing operational power while developing brands, especia...
Assessment of detecting minimum length limit changes for crappie in two Alabama reservoirs

Abstract The objectives of this study were to compare population metrics prior to and after the initiation of a minimum length limit for black crappie Pomoxis nigromaculatus and white crappie Pomoxis annularis in two reservoirs in Alabama, USA. In addition, we estimated recruitment variability and incorporated this stochastic component into a simulation model to assess the effects of three different minimum length limits on population and fishery metrics. Fish were sampled from October 1990–1991 to 2000 with trap nets, aged with otoliths, and population metrics including recruitment (age-0 catch), catch rates of age-2.5 and older fish, and length-based stock density indices were determined. We found no differences in population metrics between pre- and post-length limit time periods. We compared the effects of 203, 229, and 254 mm minimum length limits and predicted the long-term response of abundance of age-3 and older fish, angler catch, and stock density indices. Low, medium, and high levels of exploitation were explored and recruitment was varied at rates similar to observed data. Power analysis was performed using modeling results to estimate the number of years of sampling required to detect differences in population and fishery metrics in relation to changes in minimum length limits. Differences in population parameters resulting from a change in a minimum length limit were not likely to be detected with a reasonable amount of sampling effort in our populations where the recruitment CV was 70% or greater. The ability to statistically detect population and fishery changes in response to minimum length limits was dependent upon recruitment variation, exploitation rate, the magnitude of the change in a minimum length limit, and sampling duration.
Upper limit for magnetoresistance in silicon bronze and phosphor bronze wire

The electrical resistivity of silicon bronze and phosphor bronze was measured in magnetic fields from 0 to 14 T and at temperatures between 2 and 300 K. At any fixed temperature, the change in resistivity to 14 T was less than a few parts in 100,000. Thus, these bronzes are excellent for use in high magnetic fields where constant resistance is required. Welding leads to the sample was found to be superior to soldering. The soldered contacts were subject to spurious resistivity changes that resulted from superconducting transitions in the solder.
Performance of adaptive radar in range-heterogeneous clutter

Abstract The performance of adaptive radar in range-heterogeneous clutter is a topic of practical interest, since radars are often trained over nonhomogeneous stretches of clutter. In this paper, the performance of eigenanalysis-based Doppler radar is investigated in a nonhomogeneous clutter environment, and is compared to the sample matrix inversion (SMI) and the generalized likelihood ratio (GLR) methods. Two clutter models are considered: edge transition and Weibull range-dependent. It is shown that in the asymptotic case (when the number of samples used to estimate the covariance matrix is large) the location of the clutter edge affects SMI and GLR, but not the eigencanceler. It is further shown that the effect of the nonhomogeneity in the clutter-edge model is to reduce the adaptive processor's training sample support, making the eigencanceler the preferred processor choice. In the Weibull range-dependent model, all processing methods perform poorly when the noise power variance is high. As the variance is reduced, the eigencanceler outperforms SMI and GLR for small training sets, similar to the homogeneous case.
Oxygen-transport properties of liquid-crystalline polyesters based on 4,4'-bibenzoic acid

This study examined the oxygen-transport properties of aromatic liquid-crystalline (LC) polyesters of 4,4 0 -bibenzoic acid (BB) and an aliphatic diol. The effect of the spacer length was probed by the number of methylene groups in the diol being increased from 3 to 6. Parallel studies were performed on polymers in which the LC character was reduced or removed by copolymerization with 30 mol % nonmesogenic isophthalic acid (BB-30I) or by the replace- ment of BB with 4,4 0 -oxybis(benzoic acid) (OBB). The oxy- gen-transport properties were interpreted in terms of the solid-state structure as revealed by the thermal behavior and wide-angle X-ray diffraction. The strong odd-even effect of the spacer length that characterized the thermal transitions of the BB polyesters was weak or absent from the oxygen- transport properties when the effect of crystallinity was con- sidered. Permeability and diffusivity tended to increase with the spacer length. The lower oxygen permeability of all the BB polyesters compared with that of the BB-30I copo- lyesters and the OBB polyesters was due primarily to lower oxygen solubility. The low solubility of the noncrystalline LC phase was ascribed to a smaller free-volume hole size and possibly to a lower free-volume hole density in compari- son with an amorphous glass. The solubility of oxygen in the noncrystalline regions of the BB-30I copolyesters and in the amorphous OBB polyesters conformed to the relationship between the solubility and the glass-transition temperature previously established for amorphous and glassy aromatic polyesters. 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 30-37, 2007
Thermal evaporation of gas within galaxies by a hot intergalactic medium

High-temperature (about 100 million K) intergalactic gas interacts with cooler embedded gas within galaxies and extragalactic clouds principally by thermal evaporation. From Cowie and McKee's (1977) model for evaporation of spherical interstellar clouds in pressure balance with a hot ambient medium, solutions are obtained for oblate and prolate spheroidal symmetry. The results are applied to evaporation of gases within spiral and elliptical galaxies, and can be extended to evaporation of filamentary clouds in the interstellar medium.
NASA Fixed Wing Project Propulsion Research and Technology Development Activities to Reduce Thrust Specific Energy Consumption

This paper presents an overview of the propulsion research and technology portfolio of NASA Fundamental Aeronautics Program Fixed Wing Project. The research is aimed at significantly reducing the thrust specific fuel/energy consumption of notional advanced fixed wing aircraft (by 60 percent relative to a baseline Boeing 737-800 aircraft with CFM56-7B engines) in the 2030 to 2035 time frame. The research investments described herein are aimed at improving propulsive efficiency through higher bypass ratio fans, improving thermal efficiency through compact high overall pressure ratio gas generators, and exploring the potential benefits of boundary layer ingestion propulsion and hybrid gas-electric propulsion concepts.
Coordinate rotation studies of H−, He−, Be−, Mg− resonances: Basis set and configuration list dependence

We have performed coordinate rotated configuration interaction calculations on well-studied Feshbach resonances of H− and He− and on 2P shape resonances of Be− and Mg−. The focus of our efforts was the dependence of computed resonance energies on both the quality of the atomicorbital basis and the level of treatment of electron correlation. Our results indicate that great care must be taken to guarantee that a basis is adequate; commonly used quantum-chemistry bases are probably far from satisfactory. Our findings also indicate that a proper treatment of inner-shell orbitals within coordinate rotation calculations is a formidable task. We are therefore encouraged to look carefully for modified coordinate rotation techniques that focus on the active valence-level orbitals and may avoid spurious complex energies arising from improper treatment of inner shells.
A novel cDNA isolated from the mouse eye lens encoding a protein with zinc fingers and a KRAB domain.

A cDNA clone, pMLZ-8, was isolated from a newborn mouse eye lens cDNA library using a consensus zinc finger cligonu-cleotide hybridization probe. The cDNA contains an open reading frame that conceptually encodes a 606 amino acid protein. The protein possesses a “KRAB” domain at its amino-terminus and has a carboxy-terminal region with fifteen consensus C2H2 zinc fingers. PCR analysis reveals the presence of pMLZ-8 mRNA in lens, liver, kidney, spleen, and brain of newborn mice.
Intermittent wind close to the ground within a grass canopy

Wind speed was measured at a height of 1 cm above the ground and at several other heights in and above a canopy of tall fescue grass (Festuca arundinacea) using single hot-wire and triple hot-film anemometers. The plant area density in the canopy was concentrated close to the ground, with ∼75% of the plant area standing belowz=15 cm, wherez is height above the ground. The frequency distributions of horizontal wind speeds,s, were sharply skewed towards positive values at all measurement heights, but were most highly skewed near the ground where the coefficient of skewness ranged from 1.6 to 2.9. Above mid-canopy height, the frequency distribution ofs was described reasonably well by a Gumbel extreme value distribution. Average wind speed,S, decreased exponentially with depth into the canopy with an exponential scale length of abouth/2.8, whereh is the height of the canopy. Atz=1 cm, the value ofS was about 11% of the surface-layeru *. The standard deviation of the fluctuations of the vertical and horizontal components of the wind speed also decreased exponentially with depth inside the canopy with a scale length of abouth/2.5. Inside the canopy, the Eulerian integral time scales for the vertical (Γ w ) and horizontal (Γ u ) components of wind speed were about 0.1 s and 1.0 s, respectively, and were approximately constant with height. Above the canopy, these time scales increased sharply and, atz=2.25h, Γ w and Γ u were approximately 1.0 and 3.0s, respectively. Turbulence length scales in the vertical and downwind directions, Γ u and Γ w ·U, respectively, were approximately 1 cm for heights between 1 to 10 cm above the ground inside the canopy, while atz=2.25h, they were about 55 cm and 277 cm. Relatively quiescent periods (lulls) in the air close to the ground were interrupted frequently by gusts. The frequency of occurrence of gusts appears to be correlated with the value of the local shear near the top of the canopy.
Dehydration of 2-Methyl-1-cyclohexanol: New Findings from a Popular Undergraduate Laboratory Experiment

The mineral acid-catalyzed dehydration of 2-methyl-1-cyclohexanol has been a popular laboratory exercise in second-year organic chemistry for several decades. The dehydration experiment is often performed by organic chemistry students to illustrate Zaitsev’s rule. However, sensitive analytical techniques reveal that the results do not entirely corroborate with Zaitsev’s rule. Previous reports pertaining to this experiment have been limited by two factors: (i) it is difficult to separate 3- and 4-methyl-1-cyclohexene on a standard gas chromatography (GC) column and (ii) methods of accurate detection, identification, and quantification of trace minor products have been lacking. The current study uses gas chromatography–electron impact mass spectrometry (GC–MS) and quantitative nuclear magnetic resonance (qNMR) to identify and quantify not only the putative 1-, 3-, and 4-methyl-1-cyclohexene products but also several minor products such as methylenecyclohexane and ethylidenecyclopentane. Performing the dehyd...
The Link Between Gasoline Prices and Vehicle Sales

This paper examines the link between fuel prices and sales of cars and trucks. U.S. automakers have long denied that such a link exists. One source of this false belief is an obsession with the crude count of units sold, equating Hummers with Minis. Another source is the conventional “wisdom” that Americans are unwilling to pay for fuel economy. The paper presents theoretical reasons and market evidence that refute Detroit's conventional wisdom. American manufacturers' reaction to rising fuel prices over the last few years revealed the shortcomings of the U.S. automakers' recent product and powertrain strategies. The effect of rising fuel prices has, in effect, been offset by reducing prices of vehicles in inverse proportion to fuel economy. Thus, unit sales of large SUVs could be maintained, but their revenue (and profit) fell because vehicle prices were cut, directly or indirectly. The paper concludes with a few practical guidelines that business economists should use to prevent their companies from experiencing the recent massive losses experienced by the U.S. automobile industry.
Evolutionary search: gradients and information.

Abstract To better understand evolution one might view evolution as a search algorithm proceeding through a search space. The search method implemented by reproduction with mutation and selection of the fit does not perform efficiently on many search spaces. Characteristics of the search space are critically important to the effectiveness of the search algorithm. The “gradients” of and the “information” in a search space are used in this paper to study performance of “evolutionary” search algorithms.
Role of impact excavation in distributing clays over Noachian surfaces

[1] Spectrometers have detected clay-bearing units in and on much of the ancient Martian crust. Geothermally heated aquifers in basaltic rock provide conditions conducive to forming Fe/Mg phyllosilicates at depth. Throughout the Noachian period, a high flux of km-scale bolides excavated buried materials and distributed them over the surface. We use the Maxwell Z-model to quantify the volume and final location of excavated clay-bearing material. We focus on two potentially detectable properties: the volume of clay-bearing material ejected as a fraction of total ejected volume and the volume percentage of clay-bearing material in the ejecta as a function of distance from the crater's rim. Generally, the volume percentage of clays in the ejecta is greatest for craters less than 25 km in diameter. Larger crater sizes incorporate a higher fraction of clay-poor material because they excavate to greater depths at which clays are likely absent. Specific trends in bulk clay volume fraction and the distribution of clay fraction across the ejecta deposit as a function of crater size depend on the depth to the clay-rich layer and its thickness. Impact excavation likely explains clays associated with ejecta deposits and may reveal clues about the volatile content and stratigraphy of the upper Noachian crust. Applying our model to the Mawrth Vallis region suggests that a clay layer a few hundred meters thick is buried at the −3000 m elevation contour. Given that clay layers are likely thin and buried in the upper 3 km of the crust, we predict that small to mid-sized craters (<25 km) will best exhibit detectable amounts of clays and that these clays will be most abundant in the crater wall and rim and less so in distal ejecta.
Numerical Simulations for Low Energy Nuclear Reactions to Validate Statistical Models

Abstract We revisit issues regarding the statistical model calculations in the fast energy range, such as the energy average cross sections using different statistical assumptions. We perform numerical simulations by generating the resonances using the random matrix theory, and compare the energy (ensemble) average cross sections with the statistical models, such as the theories of Moldauer, HRTW (Hofmann, Richert, Tepel, and Weidenmuller), KKM (Kawai, Kerman, and McVoy), and GOE (Gaussian orthogonal ensemble). An improved parameterization for the channel degree-of-freedom is proposed, and limitation of the statistical theories is discussed.
The effect of texture and microstructure on deformation of zinc coatings

Electrogalvanized coatings of three different weights (30, 70 and 100 g/m2) and hot dip Galfan® and Galvalume® coatings were characterized by scanning electron microscopy (SEM) and x-ray diffraction. Changes in surface morphology and texture in the coatings were monitored as a function of strain in uniaxial tension tests. The electrogalvanized coatings exhibited texture favorable for basal plane slip and consequently strong texture changes developed during straining. The ability to accomodate strain by plastic flow prevented cracking in the electrogalvanized coatings and ensured good substrate coverage except in the thinnest coating at high strains. The Galfan coatings had a strong basal plane texture and therefore an unfavorable orientation for plastic flow. As a result strain was primarily accomodated by cracking and texture changes with strain were minimal. Galvalume coatings accomodated strain by interdendritic cracking even at low strains, despite close-to-random texture in these zinc rich regions.
Further comments on the evidence for post-retinal storage

A critical re-examination of the perceptual reports given in the experiments described by Haber and Nathanson reveals confirma-tion of the essential elements of the phenomena previously reported by Parks. Specifically, it is argued that a moving stimulus viewed through a narrow stationary opening gives rise to percepts containing more stimulus information than is, in fact, available to the eye at any instant.
Deletion of the pleckstrin and phosphotyrosine binding domains of insulin receptor substrate-2 does not impair its ability to regulate cell proliferation in myeloid cells.

32D IGF-I receptor (IR) cells are IL-3-dependent myeloid cells that can be induced to differentiate into granulocytes by IGF-I. Like the parental 32D cells, 32D IGF-IR cells do not express the insulin receptor substrate (IRS)-1 or IRS-2. We investigated the effect of ectopic expression of IRS-2 in 32D IGF-IR cells. Expression in these cells of a wild-type IRS-2 inhibits IGF-I-induced differentiation, and the cells grow indefinitely in the absence of IL-3. We also investigated the effect of a mutant IRS-2 lacking both the pleckstrin (PH) and the phosphotyrosine-binding (PTB) domains, which are known to bind to the IR. The ∂PHPTB IRS-2 is fully as capable as the wild-type IRS-2 (and wild-type IRS-1) to stimulate the growth and inhibit the differentiation of 32D IGF-IR cells. In contrast, an IRS-1 protein lacking the same PH and PTB domains is completely inactive in blocking differentiation and stimulating IL-3-independent growth of 32D IGF-IR cells. The ∂PHPTB IRS-2 protein is dependent for its effect on an...
Efficacy of common surgical compounds in preventing articular chondrocyte death from desiccation

Purpose of this study was to identify potential substances that prevent desiccation of chondrocytes. Macroscopically normal bovine cartilage explants (n = 80) were exposed to room air, or covered with surgical lubricant, Lactated ringer (LR) or Seprafilm (Genzyme Biosurgery, Cambridge, MA) for 0, 30, 60 or 120 min. The viability of superficial chondrocytes was measured after 48 h of incubation in tissue culture media at 37 °C by Live/Dead staining. Chondrotoxicity was measured as the extent of cell death below the articular surface. Statistical analysis was performed with a two-way analysis of variance on the data set and a subsequent Tukey’s post hoc test. Chondrocyte death correlated positively with the length of exposure, regardless of the treatment (p < 0.0001). The extent of superficial chondrocyte death was minimally lower in the LR (89.1 ± 2.6 %, 80.8 ± 1.2 %) and surgical lube (84.3 ± 1.8 %, 75.9 ± 2.7 %) groups than the control (82 ± 5.7 %, 65.6 ± 13.3 %) and Seprafilm group (77.6 ± 3.9 %, 63.3 ± 6.9 %) (p < 0.001) at the first two time points, with no significant difference between the latter groups. After 60 and 120 min, surgical lube resulted in less chondrocyte death than all other groups (70.4 ± 6.8 % and 60.9 ± 5.9 %, all p < 0.0001). The data suggest that depending on the expected length of exposure of the articular cartilage surface, different compounds appear to be protective. For exposures exceeding 60 min, surgical lubricant demonstrated the highest protective potential. Results from this study indicate that protecting exposed articular surfaces with surgical lubricant for orthopaedic procedures lasting more than 1 h lead to decreased chondrocyte death and suggest improved cartilage functional outcomes postoperatively.
Evidence for the presence of glutamate synthase in extracts of carrot cells cultures

Summary Extracts of wild carrot, either dialysed or biogel treated, catalyse the oxidation of NADPH in the presence of a-ketoglutarate and L-glutamine. The oxidation does not occur with ammonia at similar concentration to L-glutamine. NADH and L-asparagine can substitute in the reaction. Glutamine synthetase is also present in these extracts. The possibility that ammonia is assimilated in plants via glutamine synthetase and glutamate synthase now exists and is discussed.
Cloning and Characterization of the Type I Inositol 1,4,5-Trisphosphate Receptor Gene Promoter REGULATION BY 17β-ESTRADIOL IN OSTEOBLASTS

The inositol 1,4,5-trisphosphate (InsP3) receptor is essential for signal Ca2+ release from intracellular stores and for capacitative Ca2+ entry. We have isolated the promoter and proximal DNA segments of the human type I InsP3 receptor gene. Transcription initiation in human G-292 osteosarcoma and HL-60 promyelocytic leukemia cells was shown to occur predominantly from an adenine residue located 39 base pairs downstream of a consensus TATA box element. Upstream DNA including the TATA box promoted directional transcription of a chloramphenicol acetyltransferase reporter gene when transfected into G-292 cells. A negative regulatory element in the distal promoter and a positive element in the proximal region were identified by deletion mapping and transcription assays. The proximal region enhanced transcription in response to 12-O-tetradecanoylphorbol-13-acetate or serum, but conferred transcriptional repression in response to 1,25-dihydroxyvitamin D3 or 17β-estradiol. The repressive effect of 17β-estradiol was mediated by the nuclear estrogen receptor, as estrogen-dependent transcriptional repression was inhibited by the antiestrogen tamoxifen and the estrogen receptor antagonist ICI 182,780. This is the first study of the type I InsP3 receptor gene promoter, and the results suggest a mechanism by which chronic estrogen treatment of osteoblasts affects type I InsP3 receptor gene expression, signal transduction, and secretion.
Management of fatty acid oxidation disorders: a survey of current treatment strategies.

Standardization of the nutritional care for patients with fatty-acid oxidation disorders is lacking. A literature review and national survey of metabolic dietitians describes the range of therapeutic strategies currently employed in the U.S. to treat patients with fatty-acid oxidation disorders. Questionnaire responses provided by dietitians specializing in metabolic disorders evaluated practices used for treatment of fatty acid oxidation disorders, medium-chain acyl-CoA dehydrogenase deficiency (MCAD), very-long-chain acyl-CoA dehydrogenase deficiency (VLCAD), long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHAD), long-chain acyl-CoA dehydrogenase deficiency (LCAD), and Trifunctional Protein deficiency (TFP). This survey reveals a significant lack of evidence supporting the protocols in use. Recent advances in tandem mass spectrometry technology promises an increase in the number of identified patients with fatty-acid oxidation disorders, which reinforces the need for comprehensive, clinical research studies to determine optimal care for patients with these genetic disorders.
High-resolution signal demodulator for white-light interferometric sensing systems for smart structures

White light interferometric sensing systems are very attractive for application in smart structures due to the fact that they read out the absolute path differences from the transducers so that calibration schemes and device history do not have to be used and that they can be serially multiplexed. The basic output from such systems consists of arrays of data containing complex interference patterns. In this paper, a new technique is presented in which the signal from one or more white light interferometers can be demodulated with high resolution. In the technique, the conventional demodulation approach of a Fizeau wedge and linear detector array is replaced by a rotated wedge and a 2-D array such as a CCD. This results in a sampling resolution equal to the linear sampling number of points squared. A theoretical description of the technique is given and planned experimental validation is described.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A tale of tourism in two cities.

Abstract This study sought to extend past research on rural residents' perceptions of community tourism development. Residents from two Arizona cities, each at different levels of tourism development, were compared on their perceptions of tourism. After controlling for development, a hierarchical model testing the relative contribution of variable sets related to resident characteristics and social exchange theory in explaining perceptions was examined. Of special interest was a social exchange variable set representing balance of power. The linear relationship between significant predictors from the model and perceptions was then compared across samples. Results indicate that differences existed between cities, and that balance of power measures were significant predictors of perceptions. Implications are discussed.
Focal alteration of dendrites and astrocytes in rat cerebral cortex during initiation of cobalt-induced epileptiform activity.

Abstract The epileptic focus induced by pial surface iontophoresis of cobalt is exquisitely confined to the upper three laminae of sensorimotor cortex, occupying a tissue volume of 130 mm3 showing no light microscopic evidence of injury to neural cells. At the time of initiation of epileptiform discharge, ultrastructural cytopathology is relatively confined to dendrites and astrocytes, which are severely distended in association with dispersion of their organelles. Neuronal perikarya, axons, synaptic terminals, and blood vessels are relatively unaffected, and no alteration of fine structure is seen in lower cortical layers. Ionic cobalt induces a major disturbance of cation homeostasis in neural aggregates of cerebral cortex, manifested by cytopathologic effects during the initiation of epileptiform discharge, which are relatively confined to the intracellular compartment of dendrites and astrocytes.
Microbe-based electrochemical sensing systems

Abstract The combination of micro-organisms with electrochemical sensors can result in new sensing systems with extended analytical capabilities. The most common approaches for this combination are microbial electrodes and microbiological assays which utilize electrochemical detection.
A low-cost light-emitting diode photic stimulator

Abstract A simple, low-cost circuit for using an LED to elicit flash visual evoked potentials is presented. The major advantages of using an LED are discussed.
Chimp cultural diversity.

The special News Focus of 25 June (p. [2070][1]) by Gretchen Vogel highlights papers in Nature and the Journal of Human Evolution reporting that chimpanzees show regional learned behavioral differences (multiculturalism), but it does not mention that phylogeographic studies would lead us to expect
Limitations of an eddy-correlation technique for the determination of the carbon dioxide and sensible heat fluxes

A modified infrared CO2 gas analyzer, a small thermocouple assembly, a heated-thermocouple anemometer for horizontal wind, and a propeller-type vertical wind sensor were used to measure the eddy fluxes of heat and CO2 above a corn crop. Experimental results of these fluxes are discussed. The main sources of errors of the eddy fluxes using these instruments were estimated:
Casein kinase 1 promotes initiation of clathrin-mediated endocytosis.

In budding yeast, over 60 proteins functioning in at least five modules are recruited to endocytic sites with predictable order and timing. However, how sites of clathrin-mediated endocytosis are initiated and stabilized is not well understood. Here, the casein kinase 1 (CK1) Hrr25 is shown to be an endocytic protein and to be among the earliest proteins to appear at endocytic sites. Hrr25 absence or overexpression decreases or increases the rate of endocytic site initiation, respectively. Ede1, an early endocytic Eps15-like protein important for endocytic initiation, is an Hrr25 target and is required for Hrr25 recruitment to endocytic sites. Hrr25 phosphorylation of Ede1 is required for Hrr25-Ede1 interaction and promotes efficient initiation of endocytic sites. These observations indicate that Hrr25 kinase and Ede1 cooperate to initiate and stabilize endocytic sites. Analysis of the mammalian homologs CK1δ/e suggests a conserved role for these protein kinases in endocytic site initiation and stabilization.
Heterotrimeric GTP-Binding Proteins (G Proteins) and ADP-Ribosylation Factor (ARF) Regulate Priming of Endosomal Membranes for Fusion

An in vitro assay that measures endosome fusion was used to characterize the role of guanosine triphosphate (GTP)-binding proteins in endocytosis. Guanosine 5',3-(thio)triphosphate (GTP gamma S), a nonhydrolyzable analog of GTP, stimulates the binding of cytosolic factors to the endosomal membrane (priming). GTP gamma S also enhances vesicle aggregation, resulting in the formation of an intermediate that is resistant to dilution. In this report we demonstrate that priming precedes the appearance of a dilution-resistant intermediate. Thus, GTP-binding proteins are involved in multiple sequential events preceding endosome fusion. Both heterotrimeric G proteins (G proteins) and ADP-ribosylation factors (ARFs) are GTP-binding proteins that regulate undefined steps involved in endocytosis. The addition of G beta gamma subunits of G proteins to the in vitro fusion assay resulted in inhibition of priming. In contrast, addition of ARF to the assay enhanced priming. Thus, heterotrimeric G proteins and ARF may regulate endocytosis by mediating the binding of cytosolic factor(s) required for fusion to the endosomal membrane. Taken together, the results show that multiple GTP-binding proteins regulate a series of distinct biochemical events required for endosome fusion.
Detection of metabolites of toxic alkylmethylphosphonates in biological samples.

The major metabolites and breakdown products of some toxic organophosphonates are their respective alky-methylphosphonic acids. These acids ionize at physiological pH and are not amenable to gas chromatographic analysis in their underivatized forms. Their detection in biological samples has been difficult because of their presence at only trace levels. Existing analytical methods were developed mainly for measuring these phosphonic acids in environmental samples and at higher concentrations. In this study, we devised a gas chromatographic/mass spectrometric method to provide confirmation and quantification of the organophosphonic acids of soman (GD), sarin (GB) and GF in blood and urine. This report describes the various derivatization conditions that we have studied and demonstrates the characteristic mass spectra by different ionization techniques.
Simple Chromatographic Method for Simultaneous Analyses of Phosphatidylcholine, Lysophosphatidylcholine, and Free Fatty Acids

This study describes a simple chromatographic method for the simultaneous analyses of phosphatidylcholine (PC) and its hydrolytic degradation products: lysophosphatidylcholine (LPC) and free fatty acids (FFA). Quantitative determination of PC, LPC, and FFA is essential in order to assure safety and to accurately assess the shelf life of phospholipid-containing products. A single-run normal-phase high-performance liquid chromatography (HPLC) with evaporative light scattering detector has been developed. The method utilizes an Allsphere silica analytical column and a gradient elution with mobile phases consisting of chloroform: chloroform–methanol (70:30%, v/v) and chloroform–methanol–water–ammonia (45:45:9.5:0.5%, v/v/v/v). The method adequately resolves PC, LPC, and FFA within a run time of 25 min. The quantitative analysis of PC and LPC has been achieved with external standard method. The free fatty acids were analyzed as a group using linoleic acid as representative standard. Linear calibration curves were obtained for PC (1.64–16.3 μg, r 2 = 0.9991) and LPC (0.6–5.0 μg, r 2 = 0.9966), while a logarithmic calibration curve was obtained for linoleic acid (1.1–5.8 μg, r 2 = 0.9967). The detection and quantification limits of LPC and FFA were 0.04 and 0.1 μg, respectively. As a means of validating the applicability of the assay to pharmaceutical products, PC liposome was subjected to alkaline hydrolytic degradation. Quantitative HPLC analysis showed that 97% of the total mass balance for PC could be accounted for in liposome formulation. The overall results show that the HPLC method could be a useful tool for chromatographic analysis, stability studies, and formulation characterization of phospholipid-based pharmaceuticals.
INFANT EYE MOVEMENTS : QUANTIFICATION OF THE VESTIBULO-OCULAR REFLEX AND VISUAL-VESTIBULAR INTERACTIONS

Abstract The gain of the infant vestibulo-ocular reflex (VOR) was determined when infants were rotated either in total darkness or while they viewed visual targets consisting of a stationary spot or a full field of black and white stripes. The average VOR gain in the dark was 1.03 ± 0.014 for 1–4-month-old infants and 0.59 ± 0.03 for adult subjects tested with appropriate controls for psychological “set”. Longitudinal studies showed no significant change in gain over the first 4 months of life. Although the presence of the spot or full-field striped background increased adult compensatory gains from 0.59 to 1.0, the same visual targets had no effect on infant gains. Thus, an infant's VOR gain of nearly 1.0 apparently reduces reliance on the poorly developed smooth pursuit and optokinetic systems that, in adults, help the VOR provide perfect ocular stabilization.
Why Do Whites and the Rich Have Less Need for Education

This article hypothesizes that privileged social classes rely less on education to reproduce the next generation's social status. Privileged individuals disproportionately turn away from academics because they have many “informal” opportunities. The “aspiring classes,” conversely, are more reliant on education because they lack the advantages that come from nonacademic sources, like social networks, family relations, and other institutionalized mechanisms. Applying logistic regression to the National Longitudinal Study of Adolescent Health and its high school transcript data, this hypothesis is implied in two ways. First, when social backgrounds are controlled, African-Americans, Hispanics, and Asians are more likely to complete high school and go to college relative to white people. A second analysis shows that the relationship between family income and education is curvilinear. As income increases from poverty through the middle classes, the pursuit of education increases as socioeconomic barriers are removed. But among families with the highest annual incomes, there are marked decreases in rates of high school completion and transition to college. The article concludes that “equality of opportunity” is not achievable because numerous informal opportunities exist for traditionally advantaged segments of the US population.