cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of α-, γ-, and δ-Tocopherols on Oxidative Stability of Soybean Oil

The effectts of 0, 100, 250, 500 and 1000 ppm of α-, γ-, or δ-tocopherol on oxidative stability of purified soybean oil in the dark at 55°C were studied. We measured peroxide value and headspace oxygen consumption in the samples. Purified soybean oil was prepared by liquid column chromatography. Tocopherols acted as antioxidants or prooxidants depending on their concentration. Optimum concentrations of α -, γ -, and δ– tocopherols to increase oxidative stability was 100, 250 and 500 ppm, respectively. The tocopherols had significant prooxidant effect (P < 0.05) at higher concentrations above this.
Genetic Variants in Interleukin-28B Are Associated with Diabetes and Diabetes-Related Complications in Patients with Chronic Hepatitis C Virus Infection

Background Few studies have shown that host interleukin-28B (IL28B) genetic polymorphisms are associated with insulin resistance in patients with chronic hepatitis C virus (HCV) infection. However, the clinical relevance of this relationship is unclear.
Pituitary adenylate cyclase-activating polypeptide induces the voltage-independent activation of inward membrane currents and elevation of intracellular calcium in HIT-T15 insulinoma cells

The secretion of insulin by pancreatic beta-cells is controlled by synergistic interactions of glucose and hormones of the glucagon-related peptide family, of which pituitary adenylate cyclase-activating polypeptide (PACAP) is a member. Here we show by simultaneous recording of intracellular calcium ion ([Ca2+]i) and membrane potential that both PACAP-27 and PACAP-38 depolarize HIT-T15 cells and raise [Ca2+]i. PACAP stimulation can result in membrane depolarization by two distinct mechanisms: 1) PACAP reduces the membrane conductance and increases membrane excitability; and 2) PACAP activates a pronounced inward current that is predominantly a Na+ current, blockade by La3+, and which exhibits a reversal potential of about -28 mV. Activation of this current does not require membrane depolarization, because the response is observed when cells are held under voltage clamp at -70 mV. This current may result from the cAMP-dependent activation of nonspecific cation channels because the current is also observed in response to forskolin or membrane-permeant analogs of cAMP. We also suggest that PACAP raises [Ca2+]i and stimulates insulin secretion by three distinct mechanisms: 1) depolarization activates Ca2+ influx through L-type voltage-dependent calcium channels, 2) mobilization of intracellular Ca2+ stores, and 3) entry of Ca2+ via voltage-independent Ca2+ channels. These effects of PACAP may play an important role in a neuro-entero-endocrine loop regulating insulin secretion from pancreatic beta-cells during the transition period from fasting to feeding.
Advanced flight experiment automation development

NASA's space science program suffers under operational constraints that severely limit scientific reactivity. We describe a possible extension to an existing system that enables space science to be conducted in a more reactive manner through advanced automation techniques that have recently been used in the Space Transportation System (STS)-based Spacelab. This automation allows sophisticated autonomous control of the experiment by monitoring and dynamically controlling the progress of the experiment protocol. This new approach permits intelligent conduct of experimental research investigations whether or not the crew is available or contact with the ground is possible. We describe an intelligent software assistant that can manage the conduct of the experiment autonomously, by providing responsive telepresence science, or by assisting the astronaut operator with scientific advice. The crew could be unavailable for short periods when the experiment has low priority, or for longer periods on partially tended Space Station. We suggest this system could be developed as a ground prototype using commercial hardware, versions of which have been flight qualified, in order to provide a natural transition path towards flight use. In order to make this demonstration most valuable, we propose not to select a particular Life Sciences experiment, but to include an experiment simulator representative of major scientific domains.
Wide-Band Phase-Delay Circuit

A wide-band phase-delay circuit can be constructed provided phase delay is made to depend on both differences in length and differences in cutoff frequencies of the waveguides of the circuit.
Reciprocal excitatory synapses convert pacemaker-like firing into burst firing in a simple model of coupled neurons

Abstract Model neurons that are intrinsically capable of only repetitive single-spike firing can fire in bursts when reciprocally coupled via excitatory chemical synapses. The bursting mechanism is analyzed using a phase portrait consisting of nullclines both in the presence and in the absence of a fully activated synaptic current. The system of coupled relaxation oscillators is symmetric, and the trajectory can be described by simultaneous jumps between the free and excited potential nullclines for each oscillator. A new variant of the synaptic release mechanism for both excitation and inhibition emerges in which spike frequency adaptation terminates the synaptic coupling.
SELF-ESTEEM AS A MODERATOR OF THE RELATIONSHIP BETWEEN TASK-SUCCESS AND TASK-LIKING

The relationship between task-success and task-liking was higher for college students with high self-esteem (n = 54) than for a group with low self-esteem (n = 55). These results were discussed in ...
Important role of endogenous norepinephrine and epinephrine in the development of in vivo pressure-overload cardiac hypertrophy.

AbstractOBJECTIVESWe sought to define the role of norepinephrine and epinephrine in the development of cardiac hypertrophy and to determine whether the absence of circulating catecholamines alters ...
Driver Understanding of Sequential Portable Changeable Message Signs in Work Zones

Results of a Texas Transportation Institute driving simulator study are presented. The study's focus was the ability of motorists to capture and process information on two portable changeable message signs (PCMS) used in sequence (i.e., one PCMS following another along the edge of the roadway such that each PCMS contains part of a single message). The purpose of the PCMS is to convey information about upcoming traffic situations. Results indicate the need to keep messages at or below the four-unit maximum recommended in existing guidelines. It was found that presenting five units of information on sequential PCMS resulted in low comprehension rates, below what would be acceptable for highway applications. However, by keeping the message length to four units, it appears that the use of the sequential PCMS will result in comprehension rates comparable with those obtained by presenting the same information at a single location on a large dynamic message sign. Comprehension may be enhanced by repeating one li...
The method of fundamental solutions for the numerical solution of the biharmonic equation

Abstract The method of fundamental solutions (MFS) is a relatively new technique for the numerical solution of certain elliptic boundary value problems. It falls in the class of methods generally called boundary methods, and, like the well-known boundary integral equation method, is applicable when a fundamental solution of the differential equation is known. In the MFS, the approximate solution is a linear combination of fundamental solutions with singularities placed outside the domain of the problem. The locations of the singularities are either preassigned or determined along with the coefficients of the fundamental solutions so that the approximate solution satisfies the boundary conditions as well as possible. In many applications, these quantities are determined by a least squares fit of the boundary conditions, a nonlinear problem, which is solved using standard software. In this paper, the MFS is formulated for biharmonic problems and is applied to a variety of standard test problems as well as to problems arising in elasticity and fluid flow.
Simple formulation of radiation modes in planar multilayer waveguides

The fields of radiation modes in the semi-infinite regions above and below a dielectric multilayer can be completely specified once the reflection and transmission coefficients of the stack are known. Given these fields in the substrate or cover regions, the fields in the layers may be generated by successive application of two simple algebraic relationships that give the amplitude and phase of the standing wave in each layer in terms of the amplitude and phase of the layer above it or below it.
Infrared Index of Refraction of Tellurium Crystals

The index of refraction of tellurium has been measured for single-crystal samples having 1017 impurity atoms/cm3. The values were found to vary from 4.95 at 4μ to 4.85 at 8μ for radiation polarized with E-vector perpendicular to the C-axis and from 6.31 at 4μ to 6.20 at 8μ for the E-vector parallel to the C-axis.
A randomized trial of transcutaneous extraction atherectomy in femoral arteries: Intravascular ultrasound observations

Author(s): Nakamura, S; Conroy, RM; Gordon, IL; Deutsch, LS; Maheswaran, B; Antone, CS; Tobis, JM | Abstract: ObjectivesThe purpose of this study was to test the hypothesis that in occlusions of the superficial femoral artery, removal of atherosclerotic plaque would result in a higher long-term patency rate compared to balloon dilatation alone. A secondary hypothesis was that long term patency would be proportional to the amount of plaque removed.MethodsA randomized controlled study of patients with occluded superficial femoral arteries was performed comparing balloon dilatation alone versus a 2.7 mm or a larger (4.0 mm or 4.7 mm) transcutaneous extraction catheter (TEC) atherectomy device followed by balloon dilatation. The effect of these devices on plaque area was assessed directly by intravascular ultrasound imaging.ResultsThe mean occlusion length was 19.4 cm +/- 11.7 cm. The mean lumen area increased from 4.7 mm2 to 15.1 mm2, primarily due to balloon dilatation, but the mean atheroma area of 19.8 mm2 did not change with either size of TEC device. Although the initial procedure success rate was high (79%), the 6 month patency was only 45%. There was no difference in 6 month patency between the 3 groups.ConclusionsThe data indicate that the TEC atherectomy devices do not remove a significant amount of atherosclerotic plaque in occluded superficial femoral arteries. The 6 month patency is no different with these atherectomy devices than with balloon dilatation alone. The larger (4.0 mm or 4.7 mm) TEC device does not remove any more tissue than the smaller (2.7 mm) device. The use of intravascular ultrasound to quantitate the effects of this atherectomy device provides important insights into the mechanism of action and lack of efficacy of the TEC atherectomy catheter.
A study of spectrum fatigue crack propagation in two aluminum alloys—II. Influence of microstructures

The important metallurgical factors that influence both constant amplitude and spectrum crack growth behavior in aluminum alloys were investigated. The effect of microstructural features such as grain size, inclusions, and dispersoids was evaluated. It was shown that a lower stress intensities, the I/M 7050 alloy showed better fatigue crack propagation (FCP) resistance than P/M 7091 alloy for both constant amplitude and spectrum testing. It was suggested that the most important microstructural variable accounting for superior FCP resistance of 7050 alloy is its large grain size. It was further postulated that the inhomogenous planar slip and large grain size of 7050 limit dislocation interactions and thus increase slip reversibility which improves FCP performance. The hypothesis was supported by establishing that the cyclic strain hardening exponent for the 7091 alloy is higher than that of 7050.
Double ionization of atomic oxygen by electron impact

Abstract Laboratory measurements of the cross-sections for double ionization of atomic oxygen by electrons are presented for energies from threshold to ∼ 400 eV. A maximum cross-section of about 5.6 × 10−18 cm2 is observed at an electron energy of approx. 200 eV. Absolute cross-sections are obtained from measurements of the ratio of the cross-sections for double and single ionization, coupled with absolute cross-sections for single ionization previously measured by other investigators. The possible effects of excited oxygen reactants are examined, and the reported cross-sections are considered to be characteristic of ground state oxygen atoms.
Ion-exchange resins in non-aqueous solvents-III Solvent-uptake properties of ion-exchange resins and related adsorbents.

Abstract Solvent-uptake properties for several synthetic resins and common adsorbents were determined by the centrifugation method. Data are reported for eighteen different solvents, which include water and the common polar and non-polar organic solvents. The cation-exchange resins are of two varieties: the microreticular or gel type and the macroreticular or porous type. The latter resin being rigid and porous takes up all types of solvents, whereas the former resin, which relies on swelling of the resin matrix, does not take up the nonpolar solvents. Data for the H + form and Na + form macroreticular resin are compared. Unsulphonated polystyrene-divinylbenzene polymers which possess similar micro- and macroreticular properties to the cation-exchange resins were also studied in the same solvents. The swelling properties of these non-polar resins are compared with each other and with the polar cation resins. Other adsorbents, which are frequently used as supports in chromatography were also examined in the same solvents. Several of these have large average pore diameters and surface areas like the macroreticular resin.
Natural background determination and impact quantification in trace metal contaminated river sediments

Historic and current mining activities have contaminated stream sediments around the world with toxic heavy metals. A general lack of premining baseline data makes it difficult to quantify the extent of contamination and to set realistic remediation goals. These problems can be solved by modeling the downstream dispersion of metal anomalies based on dilution mixing of anomalous and tributary sediments. The model allows calculation of the dispersion curves of metals in stream sediments both before and after mining and also allows the quantification of any anthropogenic exaggeration of an anomaly. Mining activities were found to amplify naturally occurring metal anomalies up to 3 orders of magnitude, extending downstream dispersion trains from a natural limit of around 20 km to as much as 500 km. The dilution mixing model provides a useful tool for calculating premining dispersion trains and quantifying the effects of mining on a river basin. Such information is relevant to the understanding, litigation, an...
An electron microscopic study of the ground substance of connective tissue.

GROUND substance has been studied by histochemical, physiological and pharmacological methods. This communication reports some electron microscopic observations made on experimentally induced changes in ground substance. A technique is described for the study of ground substance with the electron microscope.
Synaptic and Intrinsic Homeostatic Mechanisms Cooperate to Increase L2/3 Pyramidal Neuron Excitability during a Late Phase of Critical Period Plasticity

Visual deprivation profoundly affects visual cortical response properties, but the activity-dependent plasticity mechanisms that underlie these changes are poorly understood. Monocular deprivation (MD) induces ocular dominance (OD) shifts through biphasic changes in cortical excitability, first decreasing responsiveness to the deprived eye, and then slowly increasing responsiveness to both the deprived and spared eyes. It has been suggested that this slow gain of responsiveness is due to homeostatic synaptic scaling, but this prediction has not been tested directly. Here we show that, in rat monocular and binocular primary visual cortex (V1m and V1b), postsynaptic strength onto layer 2/3 (L2/3) pyramidal neurons is modulated in a biphasic manner by MD, first undergoing a net decrease after 1 and 2 d MD, increasing back to baseline after 3 d, and finally undergoing a net potentiation between 3 and 6 d. The time course and direction of these synaptic changes match well the known changes in visual responsiveness during OD plasticity. Viral-mediated delivery of the GluA2 C-tail in vivo blocked these synaptic changes, indicating that, like synaptic scaling in vitro, AMPA receptor trafficking via the GluA2 C-tail is required for the delayed increase in postsynaptic strength. Finally, we also observed a delayed increase in the intrinsic excitability of L2/3 pyramidal neurons following prolonged MD. These data indicate that synaptic and intrinsic homeostatic mechanisms cooperate to increase excitability of L2/3 pyramidal neurons following prolonged MD, and suggest that these homeostatic mechanisms contribute to the delayed gain of visual responsiveness during OD plasticity.
REDUCING THE NEGATIVE CONSEQUENCES OF IDENTITY: A POTENTIAL ROLE FOR THE NONPROFIT SECTOR IN THE ERA OF GLOBALIZATION

ABSTRACT*: People of diverse backgrounds – most notably, diverse ethnic, racial and religious backgrounds – increasingly live in close proximity to one another. The trajectory is inexorable, and has many benefits. However, it also has had significant costs, including violent conflict between people with different identities, especially ethnic and religious identities. One important way to deal with this conflict starts with the recognition that people have multiple dimensions to their identities – in Amartya Sen's words, people's identities are ‘inescapably plural’. A person's identities may change over time: various contexts, and stages of life, make different dimensions of identity more salient. Society can aim to strengthen alternative identity dimensions that would substitute for and weaken ethnic, religious, and other identity dimensions that may lead to conflict and violence, instead of complementing and strengthening them. We argue that the nonprofit sector is well situated to help in this endeavor. Nonprofit organizations may provide suitable circumstances for the encouragement of single alternative identity dimensions, such as musical and sports identities, or for the development of a set of complementary dimensions of identity that do not involve ethnicity and religion. Such organizations would engage in the provision of relational goods, thus playing on the nonprofit sector's relative advantage. The paper makes a concrete proposal for a community center model that could contribute to the reduction of negative effects of identity.
Free radicals from eumelanins: quantum yields and wavelength dependence.

Abstract Formation of light-induced free radicals from natural eumelanin (from bovine eyes) and synthetic melanin (from oxidation of 3,4-dihydroxyphenylalanine) has been studied by electron spin resonance spectroscopy. Action spectra measured for natural melanins are very similar to that found for synthetic melanin, and are unaffected by the removal of associated protein. A comparison of action spectra with optical absorbance spectra shows that the former has a more marked wavelength dependence, suggesting that the chromophore that is most active in free-radical production is not the major melanin chromophore that absorbs visible light. Measurements of quantum yields for freeradical production have been made over a wavelength range from 600 to 230 nm. The efficiency of radical production from natural eumelanin is about three times greater than from the synthetic material. Although production of the melanin radicals detected is independent of oxygen, some correlation with oxygen consumption is evident; quantum yields for radical production are approximately three times those for oxygen consumption obtained under similar conditions. Possible reasons for this are discussed.
A system, using neural cell lines, to characterize HSV-1 vectors containing genes which affect neuronal physiology, or neuronal promoters.

Abstract Among the potential uses of defective herpes simplex virus (HSV-1) vectors are to study neuronal physiology, neuronal gene regulation, and to perform gene therapy of neuronal diseases. The prototype HSV-1 vector, pHSVlac, stably expresses Escherichia coli β-galactosidase from the HSV-1 immediate early (IE) 4/5 promoter in cultured rat peripheral and CNS neurons, and in neurons in the adult rat brain. The LacZ gene and the IE 4/5 promoter in pHSVlac can be replaced with genes which affect neuronal physiology or cellular promoters, respectively. A system is required to characterize these HSV-1 vectors: cultured neurons, a mixture of different kinds of neurons and glia, cannot be used. In contrast, neural cell lines represent a homogenous population of neural cells available in virtually unlimited quantities. A system, using neural cell lines, to characterize HSV-1 vectors carrying other genes or promoters is now reported: First, 4 assays are described to detect HSV-1 vector DNA, RNA transcribed from the vector, and to quantitate β-galactosidase expression. Second, 8 cell lines derived from rodents, primates, and humans were infected with pHSVlac virus and shown to express β-galactosidase. The cell lines tested included adrenergic and cholinergic mouse neuroblastoma cells, rat pheochromocytoma cells, rodent pituicytes, and human neuroblastoma cells. Infection of these cell lines should prove useful for characterizing HSV-1 vectors with molecular and biochemical assays. Third, differentiated rat pheochromocytoma and mouse neuroblastoma cells, which resemble neurons, were infected with pHSVlac virus and shown to stably express β-galactosidase. Infection of these cells should be useful for determining the effect of various HSV-1 vectors on neuronal physiology. Thus, HSV-1 vectors containing various genes or promoters can be characterized using the system described in this study.
Evaluation of the Carba NP Test for Carbapenemase Detection

The Carba NP test was evaluated against a panel of 61 carbapenemase-producing bacterial species (15 producing class A carbapenemases, 15 producing class D carbapenemases, and 31 producing metallo-β-lactamases) and against 111 isolates with non-wild-type carbapenem susceptibility but not producing carbapenemase. Carbapenemase production was verified by PCR and UV-spectrophotometric measurement of imipenem hydrolysis. No false positives were seen, but there were consistent problems with the detection of OXA-48-like enzymes and also some rarer class A enzymes.
Particle dynamics in reconnection field configurations

Abstract Trajectories of test particles are studied numerically in two types of reconnection magnetic field configurations, a single X-line magnetic field configuration and a tearing magnetic field configuration. Both adiabatic and nonadiabatic motions are examined, with special emphasis on net energy gain and time spent in the neutral line regions. They spend typically one characteristic gyroperiod in the X-line region and are ejected predominantly along field lines in the vicinity of the separatrix. Both adiabatic and nonadiabatic test particles in the tearing-type field configuration are channelled into and accelerated along the O-line region. It may be inferred from these test particle results that particle energizations are significant along the O-line region, but not along the X-line region. These results are in qualitative agreement with those obtained by a self-consistent particle simulation.
In vivo and in vitro phosphorylation regions of bone sialoprotein.

The present study for the first time evaluated both the in vitro and in vivo phosphorylation regions of bone sialoprotein (BSP) by utilizing multiple approaches and techniques. The in vitro phosphorylation sites were determined by 32 P-labeling of native BSP using purified casein kinase II (CKII), followed by peptide mapping and solid-phase N-terminal sequence analyses. The in vivo phosphorylation sites were determined by (i) derivatization with 1-S-[ 14 C]carboxymethyl-dithiothreitol ([ 14 C] CM-DTT) of the proteolytic digests of BSP, followed by isolation and N-terminal peptide sequence analysis; and (ii) analyzing the proteolytic peptides of native BSP using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Native BSP incorporated ~2.5 mol of phosphate/mol of BSP by CKII, which were distributed over four major peptide peaks and three shoulder peaks within the peptide map with varying degrees of phosphorylation. Further studies using the [ 14 C] CM-DTT thiol re...
Overring of half-factorial domains. II

An atomic integral domain D is a half-factorial domain (HFD) if for any irreducible elements α1,…,αn,β1,…,βmof D with α1,…,αn= β1,…,βm, then n = m. We explore some general properties of an integral domain D for which each localization of D is a HFD. In [5], we constructed an example of a Dedekind domain with divisor class group Z 6 which is a HFD, but with a localization which is not a HFD. We show that this construction can be extended to the case where the divisor class group of D is any finite abelian group except 1)cyclic p-group, and 2)direct sums of copies of Z 2. We close with a look at the relationship between the elasticity of an atomic domain and the elasticity of its localization.
Moose milk and hair element levels and relationships.

Milk was collected from 21 Alaskan moose (Alces alces gigas) at the Kenai Moose Research Center (MRC), Soldotna, Alaska and analyzed by atomic absorption spectroscopy for Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se and Zn. Hair samples were collected from 100 moose at the MRC to correspond with the lactation period and serve as a metabolic indicator of mineral elements stored in tissue. Published analyses of bovine milk were compared to moose milk; Al, Fe, Se and Zn were higher in moose milk by factors of 1.6 to 290. Elements potentially influenced by nutrition and those determined genetically were also considered. Elements in moose milk and hair values were compared, since mineral element levels in hair potentially reflect the availability and intake of these elements. Calcium and Mg were the only values in hair lower than the values in milk (factors of 4.2 and 1.5 respectively). Moose, as well as domestic cattle, apparently are subjected to lactation stress by the genetically deter...
An evaluation of global address space languages: co-array fortran and unified parallel C

Co-array Fortran (CAF) and Unified Parallel C (UPC) are two emerging languages for single-program, multiple-data global address space programming. These languages boost programmer productivity by providing shared variables for inter-process communication instead of message passing. However, the performance of these emerging languages still has room for improvement. In this paper, we study the performance of variants of the NAS MG, CG, SP, and BT benchmarks on several modern architectures to identify challenges that must be met to deliver top performance. We compare CAF and UPC variants of these programs with the original Fortran+MPI code. Today, CAF and UPC programs deliver scalable performance on clusters only when written to use bulk communication. However, our experiments uncovered some significant performance bottlenecks of UPC codes on all platforms. We account for the root causes limiting UPC performance such as the synchronization model, the communication efficiency of strided data, and source-to-source translation issues. We show that they can be remedied with language extensions, new synchronization constructs, and, finally, adequate optimizations by the back-end C compilers.
Natural Laws in Scientific Practice

The goal of Marc Ln his work on the relationships between laws and induction and also laws and counterfactuals are the best examples of that. This ability, coupled with his grasp of the history of science and science
Startup of a frozen heat pipe in one-g and micro-g environments - A proposed shuttle flight experiment

An attempt is made to determine how a heat pipe freezes under various low load and/or no load conditions in both one-g and micro-g environments. Also of interest are the mechanisms that can be used to restart the heat pipe after freezing has occurred. Particular attention is given to step function power reductions and the resulting distribution of the working fluid after freezing has occurred and the effect of noncondensible gases on the frozen configuration and the restart characteristics.
Finding the crosswalks on DNA.

Any busy street is organized into clearly defined places where one can cross safely from one side to the other and places where crossing is discouraged. On many a busy meiotic chromosome, there appear to be similar sorts of “crosswalks” where crossing over occurs frequently (Fig. 1). We are still learning what defines these places, and why they occur where they do. Two recent papers in PNAS, from the labs of Hugo Dooner (1) and Pat Schnable (ref. 2, in this issue) address the matter further and point out that there is still much to learn.
Reactions of molybdenum(VI) with metal ion reductants

The reactions of aqueous H2MoO4 at low pH with titanium(II), titanium(III), europium(II), vanadium(II), and germanium(II), as monitored at 430 nm, give biphasic profiles featuring a sharp rise in absorbance followed by a marked decrease (Fig. 1). The final product is the dimeric Mo(V) cation, [Mo2O4]2+, and the strongly absorbing intermediate is taken as a monomeric Mo(V) species. The molar absorbances of the transients from different reductants are not the same, nor are the rate laws governing the fadings. None of the decay curves exhibits evidence of a second order dependence on the transient. The kinetic behaviors of these systems are consistent with the intervention of successor complexes of the type , (formed by inner sphere reductions of Mo(VI)), which decompose, via first-order processes, to a monomeric Mo(V) species. The latter then experiences rapid dimerization, which is kinetically silent. The possibility that Ge(II) bypasses the unstable tripositive state by reducing Mo(VI) to Mo(IV) (which then undergoes rapid Mo(VI)–Mo(IV) comproportionation) is considered.
INVERTED AND MULTIPLE NEMATIC EMULSIONS

We investigate experimentally the structures that form when small colloidal particles are suspended in a nematic solvent. These structures are anisotropic, and their formation is driven by interactions arising from the orientational elasticity of the nematic solvent. By using inverted and multiple nematic emulsions composed of water droplets dispersed in a thermotropic liquid crystal, we identify the nature of these interactions, and demonstrate that they can be controlled by the anchoring of the liquid crystal molecules at the surfaces of the droplets. When the anchoring is normal, the droplets form linear chains, suggesting a long-range dipole-dipole attraction between the particles. By contrast, the interactions are repulsive at short range, and prevent contact of the droplets, thereby stabilizing them against coalescence. When the anchoring is planar, the droplets generate distortions that have a quadrupolar character. The resultant elastic interactions lead to more compact, but still anisotropic, clusters.
Density estimations for explosives and related compounds using the group additivity approach

Abbott. M. M., Floess, J. K., Walsh, G. E., Van Ness, H. C., AIChE J. , 21, 72 (1975). Abbott, M. M., Van Ness, H. C., AIChE J. , 21, 62 (1975). Ambrose, D., Lawrenson, I. J., J . Chem. Thermodyn., 4, 755 (1972). Ambrose. D., %rake, C. H. S., Townsend, R.. J . Chem. Thermodvn.. 7, 185 (1975). DiElsi, D. P., Patel, R. B., Abbott, M. M., Van Ness, H. C., J. Chem. Eng. Data, 23, 242 (1978). (6) Gibbs. R. E., Van Ness, H. C., Ind. Em. Chem. Fundam., 11, 410 (1972). (7) Keenan, J. H., Keyes, F. G., Hill, P. b., Moore, J G., "Steam Tables", Wiley, New York. N.Y., 1969. (8) Larkin, J. A., Pemberton, R. C., NaN. Phys. Lab (U.K ), Rep. Chem., 43 11976). < ~ -, (9) McGlashan. M. L., Rastogi. R. P., Trans. Faraday SOC., 54, 496 (1958). (10) Pemberton, R. C., Mash, C. J., J . Chem. Thermodyn., I O , 867 (1978). (11) Tsonopoulos, C., AIChE J., 20, 263 (1974). (12) Valent, V. as given in Gmehling, J., Onken, U., "Vapor-Liquid Equilibrium Data Collection, Aqueous-Organic Systems", Vol. I, Part 1, Dechema. Frankfurt, 1977, p 388. (13) Vinson, G. C., Martin, J. J., J. Chem. Eng. Data, 8, 74 (1963). (14) Wilson, S. R., Patel, R. B., Abbott. M. M., Van Ness, H. C., J . Chem. Eng. Data, preceding paper in this issue.
6-Fluoropyridoxol: A novel probe of cellular pH using 19F NMR spectroscopy

Abstract 6-Fluoropyridoxol was evaluated as an intracellular pH indicator. This molecule exhibits exceptional sensitivity to changes in pH (∼ 10 ppm acid/base shift) and a p K a ∼8.2 appropriate for physiological investigations. Using 19 F NMR spectroscopy we determined both intra- and extracellular pH in whole blood and confirmed the measurements using traditional techniques: ion-electrodes and 31 P NMR spectroscopy.
Ground Vegetation Survey for Xylella fastidiosa in California Almond Orchards

ABSTRACT Xylella fastidiosa is a xylem-limited bacterium that causes almond leaf scorch (ALS), Pierce's disease of grapevines, and other plant diseases. We surveyed ground vegetation in ALS-infected almond orchards in California's Central Valley for the presence of this bacterium. Plant tissue samples were collected throughout a 2-year period and processed for the presence of X. fastidiosa using restriction enzyme digestion of RST31 and RST33 polymerase chain reaction (PCR) products and bacterial culture on selective media. Overall disease incidence was low in the ground vegetation species; only 63 of 1,369 samples tested positive. Of the 38 species of common ground vegetation tested, 11 tested positive for X. fastidiosa, including such common species as shepherd's purse (Capsella bursa-pastoris), filaree (Erodium spp.), cheeseweed (Malva parvifolia), burclover (Medicago polymorpha), annual bluegrass (Poa annua) London rocket (Sisymbrium irio), and chickweed (Stellaria media). There was a seasonal compone...
The effect of sex hormones on the juxtaglomerular index of female mice

La testosterone, administree de faccon chronique a des souris femelles provoque und diminution statistiquement significative de l'index juxtaglomerulaire. Les femelles traitees par la progesterone ou les souris mâles et femelles des groupes controles ne presentent aucune variation. Ces constatations sont discutees en relation avec l'effet de la testosterone sur le flux sanguin renal, la pression de perfusion glomerulaire et la secretion d'aldosterone, de renine et d'erythropoietine.
Quantitative Determination of Spermatozoa Penetration of the Perivitelline Layer of the Hen’s Ovum as Assessed on Oviposited Eggs

A technique was developed to assess the number of cock spermatozoa penetrating the perivitelline layer (PL) in oviposited eggs in vivo. Two trials were conducted to test this technique and to establish correlation values between fertility and sperm penetration (SP). First, three Athens Canadian Randombred males, previously tested as having high fertility (100%), were each housed with seven hens. Sperm penetration was determined from eggs laid over a 3-d period (n = 41) with the mean number of spermatozoa penetrating the PL overlying the germinal disc (GD; 1.35 mm2 area) and nongerminal disc (NGD) areas being 162.8 and 8.4, respectively. Following removal of the males, SP was monitored to establish its duration with an average of 4.6 eggs analyzed per male per day. Mean sperm penetration during this period declined from 167.0 to .2 and from 9.2 to 0 for the GD and NGD regions, respectively. The mean duration of SP was 15.7 and 11.3 d for the GD and NGD PL, respectively. The duration of fertility was also established to be 14.0 d. There was a positive correlation between sperm penetration of the GD PL and fertility from eggs laid by naturally mated hens (r = .89, P < .001). In the second trial, three groups (1, 2, or 3) of 16 hens (35 wk of age) each were artificially inseminated weekly for 4 consecutive wk with either 100, 50, or 25 million sperm/50 microL, respectively. Inseminations were repeated weekly for 12 consecutive wk. Mean values were obtained from each of three 4-wk periods and used as replicates. Mean SP values from the GD PL for Groups 1, 2, and 3 were 402, 19.5, and 14.1, with fertility values of 95.8, 92.4, and 83.3%, respectively. Each replicate mean was obtained from approximately 24 eggs per group per day postinsemination. A significant correlation between SP of the GD PL and fertility (r = .90, P < .001) was established using artificial insemination of hens.
Use of iron oxide-coated sand to remove strontium from simulated Hanford tank wastes.

The ability of iron oxide-coated sand (IOCS) to adsorb strontium from synthetic wastes simulating the tank wastes at the Hanford Nuclear Reservation was examined in this study. These wastes have high pH and high ionic strength, containing up to 5.5 M Na+, 3.7 M NO3-, and 1.2 M OH-. The use of IOCS in such applications may be advantageous because it is inexpensive, is nontoxic, and can be prepared from readily available materials. IOCS can selectively remove strontium from solutions, even when they contain overwhelmingly higher concentrations of potentially competing cations such as Ca2+, Al3+, and Cr3+. Sr−EDTA chelates do not adsorb to IOCS. However, the interference caused by EDTA can be substantially overcome by the addition of excess Ca to the solution since Ca displaces Sr from EDTA. The adsorbed Sr can be released, and the IOCS can be regenerated by exposure to dilute acid (pH ∼3) for short periods. The physical and adsorptive properties of the IOCS remain essentially unaltered over at least several...
Phosphorus-fixing ability of high pH, high calcium, coal-combustion, waste materials

A greenhouse and laboratory study was undertaken to quantify the P-sorption capacity of high pH, high calcium, coal-combustion, waste materials and determine the amount of P fertilization necessary to overcome that P-sorption ability. Three different waste materials (bottom ash, bottom ash/fly ash mixture, and bottom ash/scrubber sludge mixture) were selected based upon their handling properties and their ability to support plant growth. A steady state was apparently established within 18 hr after adding P. Phosphorus sorption behavior was typical of precipitation rather than surface adsorption for all ash materials. The combination of high pH and readily available Ca in the bottom ash and bottom/fly ash mixture favored rapid precipitation of calcium phosphates. The β-tricalcium phosphate that apparently formed in these materials would not provide adequate P for plant growth, and fertilizing with more than 1000 kg P ha−1 would be necessary to provide the needed concentrations. The calcareous bottom ash/sludge mixture would maintain a sufficient P concentration to support plant growth because of its relatively low pH. As leaching and exposure to CO2(g) proceed in the other two ash materials, equilibrium with calcite would be established and P fixing would be a smaller hindrance to plant growth.
Stream Depletion by Groundwater Pumping in Leaky Aquifers

We present a simple approach to assess stream depletion by groundwater pumping in aquifers with leakage from an underlying source bed. The hydrogeological setting consists of a leaky aquifer that is hydraulically connected to a stream of shallow penetration. Under such conditions, the pumping rate is partially supported by the depletion of an adjacent stream. We quantify this phenomenon by deriving explicit analytical solutions that elucidate the interplay among the streambed, aquifer, aquitard, and well parameters. In particular, our solutions demonstrate how both hydraulic stream-aquifer connection and hydrostratigraphic conditions determine the possible fraction of the pumping rate supplied by the stream depletion. In leaky aquifers, this fraction decreases exponentially with the distance between a stream and a pumping well and is attenuated by a factor that depends on the streambed, aquifer, and aquitard parameters. The balance of pumping rate is supplied from recharge zone of the source bed.
ESR of Small Clusters

It is not straightforward to determine the detailed electronic and magnetic properties of individual clusters. Optical spectroscopy has been applied successfully to conventional1 and supersonic sources, but particularly for clusters larger than diatomics, the complexity of the spectra may make the analysis very difficult. Electron-spin-resonance (ESR) spectroscopy at 4 K offers a means of determining a number of important properties of small clusters, such as: 1. Multiplicity; i.e., total spin S. 2. Spin populations and s, p, and/or d character. This is obtained from the hyperfine splittings (hfs) due to the interaction of the unpaired electrons with the nuclear moments. 3. Geometry of the molecule (linear, equilateral triangle, number of equivalent nuclei, etc.). This may also be obtained from hfs. 4. Zero-field splitting, D (and E). Arises from magnetic interaction between unpaired spins (spin-spin interaction) or through second-order spin orbit interaction, when S > 1. 5. g tensor components. Shifts from the free electron value, ge = 2.0023, indicate the degree of spin-orbit coupling with excited electronic states and can indicate the presence of low-lying states. 6. Spin-rotation constants. Derived from g shifts using Curl’s equation.4 7. Electric quadrupole coupling constants. Arise from interaction of the electric field gradient with a nucleus having a quadrupole moment.
Comparison of Sanger Sequencing, Pyrosequencing, and Melting Curve Analysis for the Detection of KRAS Mutations: Diagnostic and Clinical Implications

Mutations in codons 12 and 13 of the KRAS oncogene are relatively common in colorectal and lung adenocarcinomas. Recent data indicate that these mutations result in resistance to anti-epidermal growth factor receptor therapy. Therefore, we assessed Sanger sequencing, pyrosequencing, and melting curve analysis for the detection of KRAS codon 12/13 mutations in formalin-fixed paraffin-embedded samples, including 58 primary and 42 metastatic colorectal adenocarcinomas, 63 primary and 17 metastatic lung adenocarcinomas, and 20 normal colon samples. Of 180 tumor samples, 62.2% were KRAS mutant positive, and 37.8% were negative. Melting curve analysis yielded no false positive or false negative results, but had 10% equivocal calls. Melting curve analysis also resulted in 4 cases with melting curves inconsistent with either wild-type or codon 12/13 mutations. These patterns were generated from samples with double mutants in codons 12/13 and with mutations outside of codons 12/13. Pyrosequencing yielded no false positive or false negative results as well. However, two samples from one patient yielded a pyrogram that was flagged as abnormal, but the mutation subtype could not be determined. Finally, using an electronic cutoff of 10%, Sanger sequencing showed 11.1% false positives and 6.1% false negatives. In our hands, the limit of detection for Sanger sequencing, pyrosequencing, and melting curve analysis was approximately 15 to 20%, 5%, and 10% mutant alleles, respectively.
Benign mesenchymal stromal cells in human sarcomas.

Purpose: Recent evidence suggests that at least some sarcomas arise through aberrant differentiation of mesenchymal stromal cells (MSCs), but MSCs have never been isolated directly from human sarcoma specimens. Experimental Design: We examined human sarcoma cell lines and primary adherent cultures derived from human sarcoma surgical samples for features of MSCs. We further characterized primary cultures as either benign or malignant by the presence of tumor-defining genetic lesions and tumor formation in immunocompromised mice. Results: We show that a dedifferentiated liposarcoma cell line DDLS8817 posesses fat, bone, and cartilage trilineage differentiation potential characteristic of MSCs. Primary sarcoma cultures have the morphology, surface immunophenotype, and differentiation potential characteristic of MSCs. Surprisingly, many of these cultures are benign, as they do not form tumors in mice and lack sarcoma-defining genetic lesions. Consistent with the recently proposed pericyte origin of MSCs in normal human tissues, sarcoma-derived benign MSCs (SDBMSCs) express markers of pericytes and cooperate with endothelial cells in tube formation assays. In human sarcoma specimens, a subset of CD146-positive microvascular pericytes expresses CD105, an MSC marker, whereas malignant cells largely do not. In an in vitro coculture model, SDBMSCs as well as normal human pericytes markedly stimulate the growth of sarcoma cell lines. Conclusions: SDBMSCs/pericytes represent a previously undescribed stromal cell type in sarcoma that may contribute to tumor formation. Clin Cancer Res; 16(23); 5630–40. ©2010 AACR.
Effects of cartilage-derived morphogenetic protein-3 on the expression of chondrogenic and osteoblastic markers in the pluripotent mesenchymal C3H10T1/2 cell line.

CDMP-3/GDF-7/BMP-12 treatment of pluripotent mesenchymal C3H10T1/2 cells resulted in a dose- and time-dependent change in cell morphology and in the expression of alkaline phosphatase, mRNA expression of osteocalcin, and bone sialoprotein, as well as mineralized bone nodule formation. CDMP-3 also stimulated Alcian Blue staining indicative of extracellular matrix formation without affecting aggrecan expression. CDMP-3 downregulated mRNA expression of BMP-4 and BMP-8A. CDMP-3 stimulated mRNA expression of ALK-1, ALK-2(ActR-IA), ALK-3(BMPR-IA), and ALK-4 without affecting that of ALK-6(BMPR–IB), ALK-7, and BMPR-II. These findings suggest that, under the experimental conditions studied, CDMP-3 induces the pluripotent mesenchymal C3H10T1/2 cells to express both chondrocytic and osteoblastic markers. The results further reveal potential complex interplay between the different bone morphogenetic proteins and their receptors in these processes.
All-optical clock recovery using self-pulsing two-section gain-coupled DFB lasers

High-speed optical clock recovery using two-section gain-coupled DFB lasers is described. Characteristics such as sensitivity, power penalty, wavelength/polarization sensitivity, locking bandwidth and lockup time will be presented.