cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of cytochalasin B on calcium transport by 1,25(OH)2D3- or PTH-treated chick embryonic yolk sac in vitro and in vivo

The present study was done to elucidate the mechanism(s) by which calcium is taken up or transported across the yolk sac membrane of the embryonic chick. We examined the effect of various inhibitors or experimental conditions on the uptake of calcium in vitro. Treatment with ouabain, verapamil, antimycin A and calcium ionophore A23187; substitution of choline for sodium or potassium in the buffer; or incubation of the tissue at 0°C had no significant effect on calcium uptake by the yolk sac membrane. Dinitrophenol (DNP) and lanthanum chloride (LaCl2) reduced 45Ca uptake from day 6 and 9 embryos by 15% and 30%, respectively. Cytochalasin B decreased the uptake of 45Ca in yolk sac membrane disks of day 6 embryos, but not in older embryos. The effects of cytochalasin B were explored further in embryos pretreated with either 1,25(OH)2D3 or PTH, both of which enhance calcium uptake. Cytochalasin B decreased calcium uptake in 9-day and 12-day vitamin D-treated embryos to about 60% of their hormone-enhanced level and also decreased PTH-stimulated 45Ca uptake into yolk sac disks by about 50% in embryos of all age groups tested. We also examined the effect of cytochalasin B on 45Ca transport across the yolk sac membrane in vivo. Cytochalasin B did not affect this transport in control (vehicle-treated) embryos. However, it significantly decreased the enhanced in vivo 45Ca transport in day-9 and -12 vitamin D-treated embryos approximately 30% and 45%, respectively. Additionally, cytochalasin B decreased the transport of calcium from yolk to blood by about 40% in PTH-treated day-9 embryos. These results indicated that both calcium uptake and transport by hormone-stimulated yolk sac membranes involves endocytosis but that some other mechanism(s) must also be involved. © 1993 Wiley-Liss, Inc.
Critical Values for Chacko's Homogeneity Test against Ordered Alternatives.

The purpose of this paper is to present a table of critical values for use with the ordered alternatives test developed by Chacko (1963).
Crystallization of Silver Carboxylates from Sodium Carboxylate Mixtures

Silver carboxylates can be made by the reaction of silver nitrate and the corresponding sodium carboxylates. The length of the alkyl chain has a significant impact on the product behavior. In this study, 18, 20, and 22 carbon chains (stearate, arachidate, and behenate, respectively) have been selected. All three sodium carboxylates are very insoluble in water at room temperature. Solutions are obtained above the Krafft temperature, which precipitates lamellar crystals if cooled at the proper cooling rate. Depending on the chain length, metastable morphologies, such as vesicles and tiny fibers, can be seen consecutively before hexagonal plates form. The carboxylate with the shorter chain length reaches equilibrium more quickly. All three silver carboxylates also take on a lamellar structure. Small-angle X-ray scattering (SAXS) shows that the d spacing of the crystals increases as the chain length increases. Cryo-TEM illustrates that the crystallites are the result of micelle nucleation and micelle aggregation. In addition, the crystallization process in the presence of silver bromide nanocrystals has been investigated. In the initial stage, an epitaxial interface is formed between the silver carboxylate crystallites and the cubic silver bromide grains. Budlike and strandlike structures grow because of it. The consequent strand enclosure restrains the crystal growth, which reduces the size and changes the morphology of the crystals.
VMT-Mix Modeling for Mobile Source Emissions Forecasting: Formulation and Empirical Application

A fractional split model is proposed and implemented that predicts the vehicle miles traveled (VMT) mix on links as a function of the functional roadway classification of the link, the physical attributes of the link, the operating conditions on the link, and the attributes of the traffic analysis zone in which the link lies. The fractional split model is a useful formulation for VMT-mix analysis because it accommodates boundary values of fractional VMT in a vehicle class, is easy to estimate using commonly available econometric software, and is easy to apply in forecasting mode to predict the VMT mix on each link of a network. The empirical analysis applies the fraction split model structure to estimate a VMT-mix model for the Dallas-Fort Worth metropolitan region in Texas. The results of model evaluation also are presented.
The 2-d O(3) model by overrelaxation

Abstract We investigate the 2d O(3) model by Monte Carlo simulation at couplings β up to 2.05. We measure the mass gap and the susceptibility on lattices of size L ⩽ 1024. The algorithm we use is overrelaxation and the effective dynamical critical exponent we find is z′ = 1.079(10). Even at β = 2.05 where the correlation length is 304, asymptotic scaling does not appear to set in for the standard action. At this β we observe a 20% deviation from the recent exact analytical result for m Λ MS .
A simplified View of δ → δ* Transition Energies in Compounds with multiple metal-metal bonds: The isolated δ — δ* manifold model

The energetics of the δ → δ* transition in quadruply bonded complexes are investigated using a very simple valence-bond formalism, called the isolated δ → δ* manifold (IDDM) model. In this model all electrons except for those that occupy the δ or δ* molecular orbitals are ignored, as are explicit metal-ligand interactions. The resulting equations allow the calculation of transition energies very inexpensively, albeit with poor quantitative agreement: the δ → δ* transition in prototypical quadruple-bond systems is predicted to occur at energies greater than 70,000 cm1. The model incorporates configuration interaction between the two1 A 1g configurations (|δδ| and |δ*δ*|) to roughly the same extent as do correlated all-electron calculations. The application of the method to systems that involve relative changes in δ → δ* transition energies, such as the torsional twisting of quadruple bonds, is more successful quantitatively.
Possession and Exchange of Materials in Chinese and American Preschools

Abstract Possession-related behaviors were studied in two groups of preschoolers, one in the United States and one in the People's Republic of China. In each group, 240 naturally occurring social interactions were observed and recorded. These interactions were analyzed for behaviors that related to the possession and exchange of materials. Members of both groups took materials from each other in about half of the recorded interactions. The American children, however, reacted more defensively to these actions than did their Chinese counterparts. Furthermore, possession-related disputes were more likely to result in aggressive actions in the U.S. classroom than in the Chinese ones. The Chinese children, but not their American counterparts, frequently redistributed materials to insure that everyone had equal amounts and defended their rights to clean up the materials. These findings are discussed in terms of classroom factors including abundance of materials, mobility of children, teachers' responses and soc...
Scaling limits for single-photon Kerr phase shifts in integrated EIT

We analyze integration of electromagnetically induced transparency in alkali atoms on a semiconductor chip. We derive the scaling laws for single-photon Kerr phase shifts and reduction in group velocity as a function of device dimensions.
Differential rates of evolution in the carbonic anhydrase isozymes of catarrhine primates

Abstract Homologous regions of the primary sequences of the two red cell carbonic anhydrase isozymes, CA I and CA II, were compared in Man, two great apes, three catarrhine monkeys, and sheep for 115 shared codon positions. These sequences comprised approximately 45% of the complete sequences of the isozyme molecules that were compared. A maximum parsimony method was used to determine the minimum number of nucleotide changes in the different lines of descent. An apparent slowing down in the rate of incorporation of mutational changes was indicated for both isozymes in the primate species examined. This deceleration was considerably more marked in the high-activity isozyme, CA II, than in the low-activity form, CA I.
Effect of Heterodera Schachtii On Sugar Beet Seedlings Under Monoxenic Conditions

In gnotobiotic (monoxenic) experiments, the damage to sugar beet seedlings inoculated with 1,000 and 10,000 Heterodera schachtii larvae varied directly with numbers of nematodes added, and inversely with age of seedlings at the time of inoculation. The effects produced were, 1) delayed and reduced seedling emergence, 2) stunting, 3) necrosis, and 4) infection of hypocotyls of pre-emergent seedlings. In hypocotyls and cotyledons typical giant cell formation and larval development to females was not observed, however. Symptoms in pre-emergent and young, post-emergent seedlings sometimes resembled those produced by other kinds of root and hypocotyl-infecting pathogens.
A micro-Raman spectroscopic investigation of He^+-irradiation damage in LiNbO_3

Imaging micro-Raman spectroscopy is used to investigate the materials physics of radiation damage in congruent LiNbO3 as a result of high-energy (~MeV) He+ irradiation. This study uses a scanning confocal microscope for high-resolution three-dimensional micro-Raman imaging along with reflection optical microscopy (OM), and scanning electron microscopy (SEM). The tight optical excitation beam in the Raman system allows spatial mapping of the Raman spectra both laterally and normal to the irradiation axis with ≤1 μm resolution. Point defects and compositional changes after irradiation and surface deformation including blistering and microstress are observed in the stopping region. We demonstrate that the probed area of the damaged region is effectively “expanded” by a beveled geometry, formed through off-angle polishing of a crystal facet; this technique enables higher-resolution probing of the ion-induced changes in the Raman spectra and imaging of dislocation line defects that are otherwise inaccessible by conventional probing (depth and edge scan). Two-dimensional (2D) Raman imaging is also used to determine the defect uniformity across an irradiated sample and to examine the damage on a sample with patterned implantation. The effects of different He+ doses and energies, together with post-irradiation treatments such as annealing, are also discussed.
Studies in hawaiian Diptera I: new distributional records for endemic asteia (asteiidae).

New island records are reported for five species of Asteia endemic to the Hawaiian Islands (Asteia hawaiiensis, Asteia mauiensis, Asteia molokaiensis, Asteia palikuensis, Asteia sabroskyi). These new records expand our understanding of distributions in Asteia, change the percentage of single island endemics from 78% to 33%, and have significance in how we view the process of diversification acting in this lineage. We also present a list of the known rearing records for two species in this group. Asteia montgomeryi has been recorded from Erythrina and Asteia sabroskyi has been reared from Pisonia, Urera, Charpentiera and Hibiscadelphus.
Cell-substrate interactions during sea urchin gastrulation: migrating primary mesenchyme cells interact with and align extracellular matrix fibers that contain ECM3, a molecule with NG2-like and multiple calcium-binding domains.

The migratory primary mesenchye cells (PMCs) of the sea urchin embryo are a model experimental system for the analysis of cell-extracellular matrix (ECM) interactions. Although the behavior of PMCs during gastrulation has been analyzed in considerable detail, it has proven difficult to identify specific substrate molecules with which these cells interact. Here, using a new monoclonal antibody (2.5C4) generated by an in vitro immunization procedure, we show that migrating PMCS interact with a distinct class of ECM fiber. The 2.5C4-positive fibers are distributed in a vegetal (high) to animal (low) gradient on the basal surface of the ectoderm. Three observations indicate that PMC filopodia interact directly with the fibers: (1) During gastrulation, 2.5C4-positive fibers gradually become oriented in a protominent circumferential belt that corresponds precisely to the position of the subequatorial PMC ring. (2) This fiber pattern is bloc ked by uricrosurgical removal of PMCs but is restored if PMCs are reintroduced into the embryo. (3) Examination of immunostained embryo whole mounts by confocal microscopy reveals a striking association between PMC filopodial roots and foci of fiber bundling. Double-immunostaining experiments using 2.5C4 and antibodies against previously identified matrix constituents show that the protein ECM3 is a component of the fibers. We have determined the complete amino acid sequence of ECM3 and find that this large protein (3103 amino acids) consists of an N-terminal domain similar to the mammalian chondroitin sulfate proteoglycan core protein NG2, a central region composed of five tandem repeats of a domain contained within the Ca2+-binding loop of Na+-Ca2+ exchange proteins, and a C-terminal region with no homology to known proteins. The general structure of ECM3 is similar in several respects to that of a sponge protein, MAFp4 MAFp4 is a major component of aggregation factor, an ECM complex that mediates the calcium-dependent, species-specific sorting of sponge cells. These studies establish ECM3 as a strong candidate for u PMC substrate molecule and point to several possible mechanisms by which interactions between PMC filopodia and ECM3-containing fibers could provide guidance information to migrating PMCs.
Glutathione-degrading capacities of liver and kidney in different species.

Abstract Although the liver is recognized as a major site of glutathione (GSH) synthesis, it is thought to play only a minor role in GSH catabolism. This is primarily because in the rat, the most commonly used experimental animal, hepatic γ-glutamyltransferase (γ-GT) activity is very low, whereas kidney activity is quite high. γ-GT is the only enzyme known to catalyze the initial step in GSH degradation. The present work compares γ-GT and dipeptidase activities in liver, kidney, and gallbladder of six mammalian species to assess the importance of hepatobiliary catabolism of GSH, relative to renal degradation. Marked species differences were observed in γ-GT activities, and in kidney to liver (K/L) ratios for both γ-GT concentration (milliunits/mg protein) and whole organ activities (total activity per liver or two kidneys). The K/L concentration ratios for γ-GT activities ranged from 875 in the rat to 15 in the guinea pig. Whole organ γ-GT ratios were ~150 in mouse and rat, and only 2–5 in guinea pig, pig, and macaque. Human K/L ratios calculated from γ-GT activities reported previously were similar to those of the guinea pig. Species differences were also observed in K/L ratios for dipeptidase activities, though these differences were not as large as those for γ-GT. γ-GT and dipeptidase activities were also measured in gallbladders of all species examined (except rat which does not have this organ), and were found to be comparable to those of liver. These results suggest that in species such as the guinea pig and perhaps humans, the liver and biliary tree play a prominent role in GSH turnover. Because of the low hepatic and high renal γ-GT activities of the rat, and because it does not have a gallbladder, this species may not be the best model for studying the catabolism of GSH and GSH conjugates. Use of the rat model may underestimate the contribution of liver, and overestimate that of kidney, in these degradative processes.
Perception of emotion and neurocognitive functioning in schizophrenia: what's the link?

In schizophrenia, relatively little is known about the association between deficits in emotion perception and basic neurocognitive functioning. The present study examined perception of emotion and a discrete set of neurocognitive functions in 28 treatment-resistant schizophrenic patients. Measures of emotion perception included a facial emotion identification test (still photographs presented on videotape), a voice emotion identification test (audiotape), and an affect perception test (brief interpersonal vignettes presented on videotape). Measures of neurocognitive functioning were selected based on hypothesized relationships to perception of emotion. These measures included: (a) Span of Apprehension task, a measure of early visual processing, visual scanning, and iconic read-out; (b) Degraded-Stimulus Continuous Performance Test, a measure of visual vigilance; and (c) Digit Span Distractibility Test, a measure of immediate or working memory. Among these measures, performance on the Span of Apprehension strongly correlated with performance on all three emotion perception tasks. The associations between perception of emotion and the other two measures were in the same direction, but were significantly smaller than those of the Span of Apprehension. These findings implicate the importance of early perceptual processing (i.e. visual scanning) in the ability of schizophrenic individuals to perceive emotion.
THE RECIPROCAL NATURE OF THE TESTIS-COMB RELATIONSHIP12

ZAWADOWSKY (i) has reported that ground cocks' combs fed to young male rats produce smaller testes, seminal vesicles, and prostate glands than normal. He obtained the same result by the injection of alcohol extracts of comb tissue. Buckner, Insko,and Martin (2) have shown that comb re' moval in cockerels leads to larger testes and increased fertility. Zawadowsky confirmed the result of comb removal on testis sise. From these and similar experiments Zawadowsky postulates a reciprocal relationship between sec' ondary sex characters such as the comb and the gonads, in this case, the testis. According to this suggestion, not only does the testis stimulate the comb, the accepted relationship, but the comb in turn inhibits the growth of the testis and in this waycontrols its output of male hormone. Such a regulatory me chanism would have many challenging aspects and would involve a re'consideration of accepted mechanisms of sexualphysiology.
The enthalpies and entropies of dilution of alkali halides and tetraalkylammonium halides in N-methylacetamide

The enthalpies of dilution of some alkali and tetraalkylammonium halides have been measured in N-methylacetamide at 35°C. The results approach the Debye-Huckel limiting law at low concentrations. Excess free energies and entropies were calculated from the present results and previous freezing point measurements. The excess enthalpies of the alkali halides in N-methylacetamide are in the same range as the excess enthalpies in water. The effect of changing anions is quite small in N-methylacetamide. The cation order is Li+≃Na+>Cs+>K+. The excess enthalpies of the tetraalkylammonium halides in N-methylacetamide are very different from the excess enthalpies in water, confirming the conclusion that in water the large excess enthalpies are due to hydrophobic bonding and that in N-methylacetamide this effect is not present.
Carvedilol but Not Metoprolol Reduces β-Adrenergic Responsiveness After Complete Elimination From Plasma In Vivo

Background— Carvedilol but not metoprolol exhibits persistent binding to β-adrenergic receptors (β-ARs) even after washout in cell culture experiments. Here, we determined the significance of this phenomenon on human β-ARs in vitro and in vivo. Methods and Results— Experiments were conducted on human atrial trabeculae (n=8 to 10 per group). In the presence of metoprolol, isoproterenol potency was reduced compared with controls (P<0.001). In the presence of carvedilol, isoproterenol identified 2 distinct binding sites of high (36±6%; −8.8±0.4 log mol/L) and low affinity (−6.5±0.2 log mol/L). After β-blocker washout, isoproterenol potency returned to control values in metoprolol-treated muscles, whereas in carvedilol-treated preparations, isoproterenol potency remained decreased (P<0.001 versus control). In vivo studies were performed in 9 individuals receiving metoprolol succinate (190 mg/d) or carvedilol (50 mg/d) for 11 days in a randomized crossover design. Dobutamine stress echocardiography (5 to 40 μg...
Lateral Intrusion of Natural Convection into a Horizontal Porous Structure

The fundamental features are illustrated of lateral penetration of natural convection into a horizontal porous layer in lateral communication with a heat reservoir. It is found that the important group governing the fluid mechanics of the phenomenon is the Darcy-modified Rayleigh number RA based on longitudinal (horizontal) permeability and on transversal (vertical) thermal diffusivity. It is shown that the buoyancy-driven flow has flattened c-shaped streamlines and isotherms. The flow penetrates laterally to a distance of order H RA 1/2, where H is the height of the porous layer. The net heat exchange between the porous structure and the lateral heat reservoir is described by a Nusselt number result of the type NU approximately = RA 1/2. The effect of horizontal wall temperature gradient on penetration length and heat transfer is discussed. The engineering importance of these findings is illustrated by examples related to the conceptual design of porous winding structures for rotating superconducting electric machines. 13 references.
Sintering of mixed-conducting composites for hydrogen membranes from nanoscale co-synthesized powders

The potential for highly selective, nongalvanic permeation of hydrogen through dense mixed conducting composites at elevated temperatures makes them attractive as hydrogen separation membranes. The glycine-nitrate combustion synthesis technique has been used to co-synthesize a cation-doped barium cerate protonic conducting phase together with a metallic nickel electronic conducting phase (15-35 vol% Ni). Co-synthesis of these phases results in an intimately mixed powder with particle sizes on the order of 10 nm. DTA/TGA of all as-synthesized compositions determined that a calcination temperature of 1000°C was required for full reaction of the cerate components. DTA/TGA and sintering shrinkage dilatometry were performed on calcined powders to determine that a sintering temperature of 1250°C would be adequate for achieving >90% relative density in all compositions. Bars of the material containing 25 vol% Ni were reduced at three different points in the heat treatment process (e.g., before, during, or after sintering). It was determined that there was less porosity in the sample reduced during sintering than any other. It was also seen on SEM that the primary grain size, regardless of when reduction occurred compared to sintering of the material, is less than 5 8m.
Mechanisms of Gas Turbine Regenerator Fouling

Possible mechanisms of gas turbine regenerator fouling are examined and compared with extant experimental evidence. A theoretical model of fouling which encompasses a two-phase process is proposed. It is shown that the controlling mechanism is the condensation of heavy hydrocarbon isomers which form an adhesive coating in which particulate matter subsequently become entrapped. Typical overall heat transfer and pressure drop degradation data are presented which tend to support the proposed model.Copyright © 1967 by ASME
Kinetics and subsite mapping of a d-xylobiose- and d-xylose-producing Aspergillus niger endo-(1→4)-β-d-xylanase

Abstract A previously described endo-(1→4)-β- d -xylanase produced by Aspergillus niger was allowed to react with linear unlabeled and labeled d -xylo-oligosaccharides ranging from d -xylotriose to d -xylo-octaose. No evidence of multiple attack or of condensation and trans- d -xylosylation reactions was found. Maximum rates and Michaelis constants were measured at 40° and pH 4.85. The former increased with increasing chain-length from d -xylotriose through d -xylohexaose to ∼70% of that on soluble larchwood d -xylan, and then decreased slightly for d -xyloheptaose and d -xylo-octaose. Michaelis constants decreased monotonically with increasing chain-length. Bond-cleavage frequencies were highest near the reducing end of short substrates, with the locus of highest frequencies moving towards the middle of larger substrates. These data indicated that the endo- d -xylanase has five main subsites, with the catalytic site located between the third and fourth subsites, counting from the nonreducing end of the bound substrate. The subsite to the nonreducing side of the catalytic site strongly repels its corresponding d -xylosyl residue, while the two subsites farther towards the nonreducing end of the substrate strongly attract their corresponding residues. The subsite to the reducing site of the catalytic site moderately attracts d -xylosyl residues, while the next one towards the reducing end has a high affinity for them. The residual error of the numerical estimation was allocated largely to the Michaelis constants of the different d -xylo-oligosaccharides, whose calculated values were appreciably smaller than measured values, especially for shorter substrates. This suggests that the subsite model cannot fully account for the experimental data. Estimated and measured values of maximum rates, bond-cleavage frequencies, and dissociation constant when the active site is fully occupied by substrate agreed more closely with each other.
Nanocapsules with “invisible” walls

Nanometre-thin membranes, prepared by directed assembly within lipid bilayers, are capable of unhindered transport of ions while being impermeable to medium sized molecules.
Nano-Indentation Device for Investigating the Mechanics of Compliant Materials

Indentation testing has long been used to measure the mechanical properties of a wide range of materials from metals and ceramics to brain tissue and hydrogels. The purpose of this study was to build and validate a Nano-Tissue Indenter (NTI) capable of performing indentation testing on micro-scale structures within the liver’s extracellular matrix. Two silicone-based tissue simulant materials were selected with elastic properties similar to hydrogels used for liver cell cultures. Samples of each material formulation, EcoFlex0030 (EF30) and EcoFlex0010 (EF10), were indented with NTI and also tested in unconfined compression to provide benchmark shear moduli. The resulting force and displacement measurements from NTI with resolutions of 300 nN and 700 nm respectively were analyzed using the Pietrement-Troyon model of adhesive contact. Using this method, NTI was able to distinguish a 10 kPa difference in shear modulus between EF30 and EF10 with comparable significance as unconfined compression (p < 0.001). General agreement between the results of the two test methods is evidenced by the overlapping of the mean ± S.D. range for the NTI-indentation and benchmark unconfined compression shear moduli measured for both formulations. NTI was used successfully to perform nano-indentation tests on samples of compliant material undergoing adhesive contact, similar to the extracellular matrix of organs such as the liver.
Use of a closed loop irrigated catheter in epicardial ablation of ventricular tachycardia

Catheter ablation of ventricular tachycardia (VT) often requires a combined epicardial and endocardial approach. An open irrigated catheter for epicardial ablation of ventricular tachycardia is commonly used. However, this can be associated with problems of fluid accumulation in the pericardial space necessitating repeated aspirations and interfering with catheter–tissue contact. A closed loop irrigated catheter can be a viable alternative to overcome these problems. We report our first three cases of epicardial VT ablation using a closed loop irrigated ablation catheter (Chilli II, Boston Scientific). Catheter ablation of ventricular tachycardia was performed via epicardial and endocardial approaches using a closed loop irrigated ablation catheter (Chilli II, Boston Scientific) and using 3-D mapping with EnSite/NavX system. Patients were routinely followed up after the catheter ablation procedure in clinic for any recurrence of ventricular arrhythmia. We report our first three cases of epicardial VT ablation using a closed loop irrigated ablation catheter. Power delivery was adequate with mean power of 15.2 ± 2.8, 31.1 ± 3.8, and 25.0 ± 3.3 W, respectively, in the three patients. No impedance rises were noted during the lesion formation. There was no recurrence of VT in any of the patients after 3 months of follow-up. To our knowledge, we report the first case series of epicardial VT ablation using a closed loop irrigated catheter and the EnSite/NavX mapping system. The advantages of closed irrigation, especially in conjunction with impedance-based anatomical mapping, warrant further study of its efficacy in catheter ablation from the pericardial space.
The ultraviolet photodissociation dynamics of IBr studied using state-selective translational spectroscopy

Abstract We have investigated the ultraviolet photodissociation of IBr using core-sampled state-selective ion time-of-flight mass spectrometry on the iodine and bromine atom products. The branching ratios and anisotropy parameters were determined for the I ( 2 P 3/2 )+ Br ( 2 P 3/2 ) , I ( 2 P 3/2 )+ Br ( 2 P 1/2 ) , and I ( 2 P 1/2 )+ Br ( 2 P 3/2 ) channels at 248, 267, and 304 nm. We find no evidence for the I ( 2 P 1/2 )+ Br ( 2 P 1/2 ) channel at any wavelength. The results provide information on the relative transition probabilities for the 3 Π 1 (2341) , 3 Π 0+ (2341) , and 1 Π 1 (2341) excited states in the absorption band centered at 270 nm. We have further evaluated the nonadiabatic curve crossing probability for the avoided crossing between the 3 Π 0+ (2341) and 3 Σ − 0+ (2422) states over a range of wavelengths from 250 to 270 nm. The wavelength-dependent curve crossing probability for the avoided crossing is modeled using one-dimensional Landau–Zener theory in order to estimate the location of the avoided crossing and the splitting between adiabats. A comparison with recent work at 267 and 304 nm and analogous interhalogen molecules is also provided.
Neutral lipid synthesis and storage in the intraerythrocytic stages of Plasmodium falciparum

Abstract In eukaryotic cells the neutral lipids, steryl esters and triacylglycerol, are synthesized by membrane-bound O -acyltransferases and stored in cytosolic lipid bodies. We show here that the intraerythrocytic stages of Plasmodium falciparum produce triacylglycerol using oleate and diacylglycerol as substrates. Parasite membrane preparations reveal a synthesis rate of 4.5±0.8 pmol min −1 mg −1 of protein with maximal production occurring in the mid- and late-trophozoite stages in both, membrane preparations and live parasites. In contrast to other eukaryotic cells, no discernable amounts of steryl esters are produced, and the parasite is insensitive to cholesterol esterification inhibitors. Synthesized neutral lipids are stored as lipid bodies in the parasite cytosol in a stage specific manner. Their biogenesis is not modified upon incubation with excess fatty acids or lipoproteins or after lipoprotein depletion of the culture medium. We investigated on the enzymes involved in neutral lipid synthesis and found that only one gene with significant homology to known members of the membrane-bound O -acyltransferase family is present in the P. falciparum genome. It encodes a microsomal transmembrane protein with a predicted size of 78.1 kDa, which we named Pf DGAT because of its close identity with various known acyl-CoA:diacylglycerol acyltransferases. Pf DGAT is expressed in a stage specific manner as documented by Western blotting and immunoprecipitation assays using antibodies against Toxoplasma DGAT, suggesting that Pf DGAT is the most likely candidate for plasmodial triacylglycerol synthesis.
The effects of neonatal capsaicin administration on trigeminal nerve chemoreceptors in the rat nasal cavity

Trigeminal nerve fibers in the nasal cavity respond to a variety of volatile chemical stimuli. Some of these trigeminal nerve fibers have been suggested to be capsaicin-sensitive and thus belong to a class of pain receptor rather than constituting a separate class of chemoreceptor. Our current results confirm this suggestion. Trigeminal nerve responses to volatile chemical stimuli were eliminated in rats which were injected with capsaicin on the second day of life. Animals whose nerves were unresponsive to chemical stimuli also exhibited a loss of intraepithelial peptide-immunoreactive fibers in their nasal cavities. The results of this study suggest that trigeminal nerve fibers in the nasal cavity which respond to chemical stimuli may be polymodal nociceptors which contain substance P, calcitonin gene-related peptide, or perhaps other neuropeptides.
Novel Swine-Origin (S-OIV) H1N1 Influenza A Pneumonia in a Lung Transplant Patient: A Case Report and Review of the Literature on Performance Characteristics of Rapid Screening Tests for the S-OIV

Rapid screening tests are insensitive for detecting the novel swine-origin influenza A (H1N1) virus (S-OIV), and false negatives can delay the diagnosis and initiation of appropriate antiviral therapy. The case of a 26-year-old double lung transplant recipient presenting with fever, bilateral pulmonary infiltrates, and a negative influenza direct immunofluorescent antibody on bronchoalveolar lavage is presented. A diagnosis was made, and antiviral therapy was started 10 days after the initial bronchoalveolar lavage on receipt of a positive culture for S-OIV. The published literature on the performance characteristics of rapid screening tests for S-OIV is reviewed in this clinical context.
Toward a usable general theory of oligopoly

This paper propounds a determinate and operational framework for the analysis of the oligopolistic firm's and industry's price-output equilibrium. It emphasizes the implicit collusion and restrained rivalry in the realistic market structure revealed by empirical investigators, and thereby takes a different route from the traditional Cournot-Stackelberg and game-theoretic approaches. It incorporates the multiobjective nature of the firm's decisionmaking, and draws upon nonlinear programming and parametric programming theory to offer a flexible framework to accommodate a wide variety of behavior patterns in such industries. Several simple examples employing fictional data are used to illustrate the models.
Thrombus growth and embolism on tissue factor-bearing collagen surfaces under flow: role of thrombin with and without fibrin.

Objective—At sites of vascular injury, thrombin is an important mediator in thrombus growth and stability. Using microfluidic flow devices as well as patterned surfaces of collagen and tissue factor (TF), we sought to determine the role that fibrin plays in clot stability without interfering with the production of thrombin. Methods and Results—We deployed an 8-channel microfluidic device to study coagulation during corn trypsin inhibitor–treated (XIIa-inhibited) whole blood perfusion over lipidated TF linked to a fibrillar collagen type 1 surface. Clot growth and embolization were measured at initial inlet venous (200 s−1) or arterial (1000 s−1) wall shear rates under constant flow rate or pressure relief mode in the presence or absence of Gly-Pro-Arg-Pro (GPRP) to block fibrin polymerization. Numerical calculations for each mode defined hemodynamic forces on the growing thrombi. In either mode at inlet venous flow, increasing amounts of TF on the surface led to a modest dose-dependent increase (up to 2-f...
Media literacy, media education, and the academy

This initial essay in the Media Literacy Symposium serves two purposes. First, we introduce the nine authors who have written the eight essays especially for this symposium. Second, we provide a broad context for the thinking expressed by those nine scholars. In building that context, we discuss a range of conceptual and application issues. The conceptual issues focus on the range of definitions for both media and literacy. The application issues include considerations about curriculum design, teaching, and the assessment of media literacy.
Using comparative effectiveness research to remedy health disparities.

Health disparities are an important and continuing problem of considerable research importance. Comparative effectiveness research (CER) is an excellent vehicle to evaluate interventions to remedy disparities. We classify CER for disparities at three levels of science: basic biology, care and systems, and social and cultural context. In basic biology, genomics will delineate treatments for specific individuals and populations. Care and systems interventions are most important research areas to improve process and quality measures. However, there is evidence that correction of healthcare processes disparities will not be sufficient to improve health and that social and cultural research may be key in this regard. The methodology of CER for disparities is the same as that of other research with randomized controlled trials the gold standard and database analysis, and other observational and quasi-experimental methods important and effective. In addition, mixed methods and multilevel modeling offer promise. ...
Effects of internal scattering on X-ray microtomography image reconstruction

A computer simulation is used to study the problem of internal scattering for targets that are imaged using X-ray microtomography. A strategy is outlined for selecting X-ray energy and image resolution based on properties of the material being imaged. The X-ray scanning process is simulated by applying a Monte Carlo technique to a modeled target that emulates the material properties of a microelectronic device. The X-ray photons are subject to photoelectric absorption, Rayleigh scattering, and Compton scattering. The simulation applies a method of high-resolution image reconstruction based on discrete Fourier transforms. Examples of reconstructed images that have 0.5-/spl mu/m spatial resolution are shown for images of simulated lead and aluminum targets.
High-saturation current uni-traveling-carrier waveguide photodiodes with variable optical confinement

Uni-traveling-carrier photodiodes with variable optical confinement waveguides are proposed and demonstrated. Two different photodiode designs are compared, both demonstrating state of the art saturation current for a waveguide photodiode.
E-Z Reader: A cognitive-control, serial-attention model of eye-movement behavior during reading

The two core assumptions of the E-Z Reader model of eye-movement control during reading are that: (1) a preliminary stage of lexical access (i.e., the familiarity check) triggers the initiation of a saccadic program to move the eyes from one word to the next; and (2) attention is allocated serially, to one word at a time. This paper provides an overview of the model, some of the research that motivated its assumptions, and the various reading-related phenomena that the model can account for. This paper also summarizes how the model has been and is currently being used to guide empirical research.
Endoderm development: from patterning to organogenesis

Although the ectoderm and mesoderm have been the focus of intensive work in the recent era of studies on the molecular control of vertebrate development, the endoderm has received less attention. Because signaling must occur between germ layers in order to achieve a properly organized body, our understanding of the coordinated development of all organs requires a more thorough consideration of the endoderm and its derivatives. This review focuses on present knowledge and perspectives concerning endoderm patterning and organogenesis. Some of the classical embryology of the endoderm is discussed and the progress and deficiencies in cellular and molecular studies are noted.
Tuning T cell activation threshold and effector function with cross-reactive peptide ligands.

We have generated a panel of cross-reactive T cells by immunizing SJL mice (I-A s ) with Q144 peptide, an analog of an autoantigenic peptide (W144) of myelin proteolipid protein (PLP) 139–151 (HSLGKWLGHPDKF) in which W was replaced by Q at position 144. Following immunization with Q144, T cells were expanded in vitro with W144, which is a cross-reactive, suboptimal ligand, for Q144-specific T cells. The T cell clones responded to both ligands and grew normally on the peptide W144, but were hyperstimulated when activated by Q144 in vitro. This hyperstimulation results in a heteroclitic proliferative response with secretion of additional cytokines not induced by W144. Thus expansion of T cells by a suboptimal cross-reactive ligand effectively lowers the activation threshold so that the immunizing antigen becomes a hyperstimulating ligand for the clones. Surprisingly, when the T cell clones are grown on the hyperstimulating ligand Q144, some adapt by increasing their activation threshold. This desensitization results in a loss of response to a number of cross-reactive ligands and the appearance of a more specific T cell response. Longterm culture with the hyperstimulating ligand is sometimes associated with down-regulation of CD4 expression. These results provide an explanation for the common finding of T cell heteroclicity, and suggest that although the specificity and hierarchy of the response of T cells to peptides is determined by the TCR, activation threshold and effector functions are modified by exposure to cross-reactive ligands. This observation has implications for the development and regulation of autoimmune disease.
Toward a Good or Better Understanding of Best Practices

This commentary argues that seeking best practices in literacy instruction is not a good pursuit for the field. Instead, it argues that it would be better for the field to identify good practice, better practice, and malpractice. Further, it discusses the possible meanings of best practice and why each meaning is inadequate, relatively meaningless, or potentially misleading when compared to the concepts of good and better practice. These possible meanings include best practice as relatively good practice, as what most or expert teachers do, as achievement of valued outcomes, and as scientific evidence. Lastly, this commentary discusses why focusing on good and better practice would be better for the field and suggests some implications of that shift in perspective.
Repeat Players in the Supreme Court: The Role of Experienced Lawyers in Litigation Success

How important are lawyers in the decision making of the U.S. Supreme Court? Although legal expertise has long been assumed to benefit certain litigants, the frequency with which lawyers appear before the Court has not been directly measured. In this article, I argue that, quite apart from the status of different litigants, lawyers can be viewed as repeat players who affect judicial outcomes. Using data from the U.S. Supreme Court Judicial Data Base with data from the United States Reports, I propose and test a theory in which the informational needs of the Court are better met by more credible litigators. Thus, for example, a more experienced lawyer significantly raises the probability of a party's success. The findings testify to the efficacy of experienced counsel, irrespective of the parties they represent.
Physiological Control of Rotary Left Ventricular Assist Device

In rotary left ventricular assist device (LVAD), physiological control system is the element to automatically regulate the pump speed to ensure enough perfusion of patients. In this paper, the design of the physiological control system of rotary LVADs is reviewed first, such as criteria of physiological control system, sensors/signals, and control algorithms. Then the design of an adaptive optimal controller for permanent LVADs is discussed. A Matlab simulation program and an experimental mock circulatory loop are employed as test environments for the controller. Different physiological conditions, such as the variation of left ventricular failures and the variation of activities are simulated to study the performance of the designed physiological controller. Simulation and experimental results consistently show that the abnormal hemodynamic variables of a congestive heart failure patient are restored back to the normal physiological range by the designed controller.
Mucormycosis-Changing Status

(1973). Mucormycosis-Changing Status. CRC Critical Reviews in Clinical Laboratory Sciences: Vol. 4, No. 4, pp. 421-451.
Characteristics of high molecular weight insulins in insulinoma patients.

These studies were undertaken to characterize the high molecular weight immunoreactive insulins in plasma and tumor extracts of two patients with insulinoma, and to determine whether they are biosynthetic precursors of proinsulin. Plasma was chromatographed on a Sephadex G-50 column and fractions assayed for IRI. Three peaks were observed, one in the void volume region (6%), a peak in the proinsulin region (25%), and the largest peak comigrating with insulin standard (69%). Insulinoma slices were incubated for 4 h and high molecular weight IRI was observed in chromatographed extracts of the tumor, as well as in extracts of the incubation medium, which comprised up to 3% of the total IRI. Gel filtration chromatography of a pre-operative fasting plasma from the second patient revealed a heterogeneous distribution of IRI, with approxi: mately 53% in the high molecular weight region. At surgery an insulinoma was removed. Slices were incubated for 4 h with 14C-amino acids and extracts chromatographed. 14C-labe...
Comprehensive performance modeling and analysis of multicasting in optical networks

Multicasting is becoming increasingly important in today's networks. In optical networks, optical splitters facilitate the multicasting of optical signals. By eliminating the transmission of redundant traffic over certain links, multicasting can improve network performance. However, in a wavelength-division multiplexed (WDM) optical network, the lack of wavelength conversion necessitates the establishment of a single multicast circuit (light-tree) on a single wavelength. On the other hand, establishing several unicast connections (lightpaths) to satisfy a multicast request, while requiring more capacity, is less constrained in terms of wavelength assignment. The objective of the paper is to evaluate the tradeoff between capacity and wavelength continuity in the context of optical multicasting. To this end, we develop accurate analytical models with moderate complexity for computing the blocking probability of multicast requests realized using light-trees, lightpaths, and combinations of light-trees and lightpaths. Numerical results indicate that a suitable combination of light-trees and lightpaths performs best when no wavelength conversion is present.
Solitary fibrous tumor of the meninges Case report and review of the literature

The authors present the case of a left frontal solitary fibrous tumor of the meninges. The gross appearance of the tumor was very similar to that of a fibroblastic meningioma. Histological examination showed a mixture of spindle-shaped and round cells arranged in a collagen matrix. Immunohistochemical staining of the tumor demonstrated diffuse positive staining for CD34 and vimentin. The tumor displayed no positive staining for markers of muscle, epithelial, glial, or neurocrest differentiation or for estrogen and progesterone receptors. The MIB-1 labeling index (the percentage of positive staining tumor cell nuclei), a marker of cellular proliferation, was 1.1%. Ultrastructural studies support attributing a mesenchymal, rather than meningothelial, nature to the tumor. A differential diagnosis is discussed and a review of the literature on these rare tumors is presented.