cssi/SciSciGPT-SciSciNet huggingface dataset:
Modeling the Chemical Composition of Acid Rain in Southern California

A variety of techniques to identify and quantify acid and base components in rainwater are applied to data for southern California. Charge balance calculations using major cation and anion concentration data indicate southern California probably had alkaline rain in the 1950Ts and the 1960’s with the exception of the Los Angeles area which probably had acidic precipitation. Measurements of the chemical composition of precipitation collected in Pasadena, California, from February 1976 to September 1977 are compared with the charge balance and conductivity balance constraints. A chemical balance is used to determine the relative importances of different sources. The pH is found to be controlled by the interaction of bases and strong acids with nitric acid being 32% more important on an equivalent basis than sulfuric acid. The uncertainties in the various calculations are discussed.
Literacy versus Identity: The British Influence on Postcolonial Zimbabwe and Sudan in Tsitsi Dangarembga’s Nervous Conditions and Leila Abuleila Lyrics Alley

This article discusses the British influence on postcolonial Zimbabwe and Sudan in terms of literacy and education and how this influence leads to a conflict between modernity and identity in both societies, especially in the case of women. Two postcolonial novels are discussed: Nervous Conditions (1988) by Tsitsi Dangarembga and Lyrics Alley (2010) by Leila Abuleila. Even after the colonization ends, the British still have an influence on both societies. This influence is seen by some as a chance for better education and more development but by others as a negative influence that threatens cultural identity.
Connecting Constructivism and Brain Science

As the title suggests, Unlocking the Emotional Brain: Eliminating Symptoms at Their Roots Using Memory Reconsolidation explores how recent research regarding the brain's ability to override old emo...
Marine Harvest: Leading Salmon Aquaculture (TP)

Marine Harvest has the leading position in salmon aquaculture. Aquaculture is very much a growth business, many believing it could play a major role in solving the world's growing need for protein. The CEO is considering three alternatives for taking advantage of his firm's dominant position. Expand production in Chile, produce value-added salmon products, or backward-integrate into the salmon feed business.Learning Objective: Understand the aquaculture business.
Transport in glassy fast-ion conductors: A stud of LiAlSiO4 glass

Abstract The mechanism of ionic motion in LiAlSiO4 glass is investigated using a combination of structural (vibrational spectroscopy, X-ray diffraction) and transport (ionic conductivity) methods. We find that the material is quite a good Li+ conductor (σ ≈ 10−3μ−1 cm−1 at 500 °C), and that the vibrational density of states deduced from spectroscopic studies agrees very well with the continuous random network model. Moreover, the tendency towards ordering seen in many aluminosilicates and described by Loewenstein's rule is discussed in the context of our spectroscopic observations, and we find that the Loewenstein rule also holds approximately in this glassy material. The rigidly alternating potential seen by Li+ ions in crystalline LiAlSiO4 (β-eucryptite) is substantially altered by the disorder present in the glass. This disorder strongly reduces correlation effects on ionic motion in the glass, as opposed to the crystal, resulting in a smaller activation energy for conductivity in the glass.
Robust Control Design for a Benchmark Problem Using a Structured Covariance Approach

This paper demonstrates robust control design for a benchmark problem by using a generalised LQG approach. This approach induces a structured covariance matrix that provides insensitivity to specified parameter variations and, in special cases, yields positive real control laws.
Velocity estimators of visual motion in two spatial dimensions

Elementary velocity estimators (EVEs) of visual motion are extended from one spatial dimension to two spatial dimensions. Principles of operation of the 2D-EVEs are described and guidelines for their design are laid out. There are a number of innovations in the way the receptive fields (RFs) of the 2D-EVEs are formed to create units which detect motion in different spatial directions. A brief background on the operation of 1D-EVEs is given, and the different spatial formations that the RFs of 2D-EVEs can assume to achieve motion discrimination in specific spatial directions are discussed. It is shown that detection of motion in different directions is implemented by changing the shape of the input receptive field of the 2D-EVE. Preliminary simulation results from two special cases of motion are presented. >
A Measure of Auditor AIS Expertise: Development, Assessment, and Uses

The purpose of this study is to develop, assess, and provide uses for a measure of auditor accounting information systems (AIS) expertise. A nine-item measure of AIS expertise is developed from a review of expertise studies and pre-tests with accounting students. An assessment of the measure shows that it possesses a high level of internal consistency and construct validity (i.e., convergent and discriminant validity). Factor analysis results indicate that all nine items satisfactorily load on one factor. Given that the nine items are designed to measure auditor self-assessments of AIS expertise, this factor is labeled "auditor AIS expertise" for the purposes of this study. In addition, the results suggest that auditor AIS expertise is a unique and separate domain of expertise and not simply a by-product of general audit experience. Possible future uses of the measure, such as determining the effects of auditor AIS expertise on the identification of AIS-related control weaknesses and the customization of the measure for IT audit specialists and internal auditors, are discussed. Given the increasing complexity of corporate AIS, this study's measure should provide researchers with a tool to examine how auditors' knowledge of AIS can affect the quality of contemporary audit services.
HLA-DO IS A LYSOSOMAL RESIDENT WHICH REQUIRES ASSOCIATION WITH HLA-DM FOR EFFICIENT INTRACELLULAR TRANSPORT

The murine MHC class II molecule H2-O is expressed in B-cells and in thymic epithelium but the human equivalent, HLA-DO (DO), has not been detected, though the corresponding genes, HLA-DNA and HLA-DOB, are well known. Here we show DO to be a lysosomal resident in B-cells. Surprisingly, DO forms stable complexes with HLA-DM (DM), another lysosomal class II-like molecule which is important for class II-restricted antigen presentation. Association with DM is necessary for efficient exit of DO from the endoplasmic reticulum (ER) and thus for accumulation in lysosomes. The association is evolutionarily conserved and in mice lacking H2-M, the mouse equivalent of DM, the amount of intracellular H2-O is decreased and only minor amounts of H2-O appear to leave the ER. The DO-DM complexes survive in the lysosomal system suggesting that DO and DM functions may be intertwined.
Bone Growth in Organ Culture Modified by an Electric Field

Unidirectional pulsating electric fields caused changes in the patterns of growth in rat calvaria grown in organ culture. Morphologic pattern variations were studied by radioautographic techniques. The changes occurred at the negatively charged bone surface. In a strong field, the growth pattern became disoriented.
The laminar cylindrical wall-jet in the early part of the flow

Abstract The boundary layer equations of motion for the case of the laminar, cylindrical wall-jet have been investigated for the early part of the flow or when the boundary layer is thin compared to the cylinder. The effect of curvature has been considered by expanding the Stokes' stream function in a power series of a parameter which is the ratio of the boundary layer thickness to the radius of the cylinder, with the first term being the similarity solution to the two-dimensional wall-jet, which has been given by G lauert . The results are then restricted so that the boundary layer thickness is small compared to the diameter of the cylinder. The resulting set of ordinary differential equations has been evaluated analytically in part, and numerically for the remainder up to the second approximation. It has been found that the shear stress at the wall is greater than that of the two-dimensional case without transverse curvature. The corresponding problem of heat transfer from the surface of a cylinder surrounded by a wall-jet has been treated. The temperature distribution was also assumed expandable in a power series, the zero-th term being the same as that obtained for the two-dimensional wall-jet. The set of ordinary differential equations subsequently obtained has been evaluaed by numerical methods with a computer, for the cases of constant wall temperature and constant heat flux.
Humic substances, a possible source of environmental goitrogens

Abstract The by-products of humic substances (HS), resorcinol, orcinol, phloroglucinol, pyrogallol, 3,4- and 3,5-dihydroxybenzoic acids, and ortho - and meta -phthalic acids, have been tested for antithyroid and goitrogenic activities. By two in vitro assays all compounds, except the phthalic acids, were potent inhibitors of the thyroid peroxidase enzyme, and of thyroidal 125 I uptake and/or its incorporation into thyroid hormones using thyroid slices. Resorcinol in drinking water was goitrogenic as indicated by in vivo assay in rats. These findings, the identification of resorcinol in the water supply of an endemic goiter district in western Colombia, where increased goiter prevalence is associated with watersheds rich in organic matter, and results of elemental analysis of goitrogenic water extracts from the same district showing a composition similar to that of aquatic HS, suggest that HS degradation by-products may play an important role in the etiology of endemic goiter.
Release of the Inferior Vena Cava Ligament during Caval Thrombectomy Causing Tumor Thrombus Embolization

Intraoperative tumor embolization is a rare complication during the surgical management of renal cell carcinoma with tumor thrombus of the inferior vena cava (IVC). We present a case of pulmonary tumor embolism which occurred during liver mobilization immediately following division of the IVC ligament. We hypothesize that this patient's IVC ligament acted as an external barrier to propagation of the tumor thrombus and that its release caused the tumor to rapidly expand leading to embolization. To our knowledge, this is the first report of a pulmonary tumor embolism occurring immediately following division of the IVC ligament.
Use of an Acrylic Ester Sorbent for the Selective Adsorption of Avermectins

Previous work has shown that simple model solutes differing in their abilities to form hydrogen bonds can be selectively adsorbed from a nonpolar solvent onto an acrylic ester sorbent (Amberlite XAD-7). The goal of this work was to determine whether these sorbents could be used for the selective adsorption of members of the avermectin family of secondary metabolites. When the individual avermectins were studied, avermectin B 2a , which has four hydroxyl groups, was observed to adsorb from hexane with a higher affinity than avermectins A 2a or B 1a , which have only three hydroxyl groups each. When equimolar mixtures of the three avermectins were studied, it was observed that avermectin B 2a was preferentially adsorbed from hexane with separation factors of 2.2 ± 0.2 and 1.8 ± 0.2 relative to avermectins A 2a and B 1a , respectively.
Tar pollution of beaches in the Indian Ocean, the south China Sea and the South Pacific Ocean

During 1978, a comparative survey was made of the degree of pollution of 265 beaches in the Indian Ocean, the South China Sea, the South Pacific and along the Southern California Bight, the Mid-Atlantic Bight and the Dutch North Sea. Part of the results were published recently and elicited a number of requests for the full data set, which is, therefore, summarized in this note. Generalized observations on tar pollution are: (1) strandings from individual spills could rarely be correlated over distances longer than a few km; (2) tar is concentrated in distinct bands parallel to the water line; (3) there is a pronounced trend of vertical zonation of tar from smaller, well-rounded and soft particles near the water line to larger, flattened and hardened lumps landward; (4) buried tar is relatively uncommon, suggesting a residence time of around 30-90 days in the tropics; (5) tar concentrations display high variability indicating the need for large numbers of samples; (6) prevailing wind regimes are the main cause for seasonal variations in tar strandings. The highest beach tar concentrations were found in areas of oil production or near tanker routes, especially in enclosed seas; Persian Gulf, Red Sea and South China Sea.
In vivo chemical exchange saturation transfer imaging allows early detection of a therapeutic response in glioblastoma

Glioblastoma multiforme (GBM), which account for more than 50% of all gliomas, is among the deadliest of all human cancers. Given the dismal prognosis of GBM, it would be advantageous to identify early biomarkers of a response to therapy to avoid continuing ineffective treatments and to initiate other therapeutic strategies. The present in vivo longitudinal study in an orthotopic mouse model demonstrates quantitative assessment of early treatment response during short-term chemotherapy with temozolomide (TMZ) by amide proton transfer (APT) imaging. In a GBM line, only one course of TMZ (3 d exposure and 4 d rest) at a dose of 80 mg/kg resulted in substantial reduction in APT signal compared with untreated control animals, in which the APT signal continued to increase. Although there were no detectable differences in tumor volume, cell density, or apoptosis rate between groups, levels of Ki67 (index of cell proliferation) were substantially reduced in treated tumors. In another TMZ-resistant GBM line, the APT signal and levels of Ki67 increased despite the same course of TMZ treatment. As metabolite changes are known to occur early in the time course of chemotherapy and precede morphologic changes, these results suggest that the APT signal in glioma may be a useful functional biomarker of treatment response or degree of tumor progression. Thus, APT imaging may serve as a sensitive biomarker of early treatment response and could potentially replace invasive biopsies to provide a definitive diagnosis. This would have a major impact on the clinical management of patients with glioma.
Some unusual manifestations of cerebral aneurysms

Abstract Six cases of cerebral aneurysms which were diagnostic problems are presented and discussed. Bizarre symptom complexes and unusual background situations contributed to the diagnostic difficulties. Some patients exhibited backgrounds of cardiac and vascular disease and blood coagulation defects. Two separate episodes with different symptoms were present in other cases. Unusual symptoms were dependent on unusual size and location of the aneurysms. Acute psychotic episodes without meningeal signs were present in two patients with subarachnoid bleeding. Incomplete arteriography was another diagnostic pitfall. The diagnosis of aneurysm should be considered prominently in all instances of subarachnoid hemorrhage and in cases suggesting a mass at the base of the brain.
High-temperature creep of olivine single crystals III. Mechanical results for unbuffered samples and creep mechanisms

Abstract The dependence of steady-state creep rate on oxygen fugacity fo 2, temperature T, applied stress a, and loading orientation has been measured experimentally for unbuffered single crystals of San Carlos olivine. The stress exponent, approximately 3·5, is the same for all three 45° loading orientations and is also identical with the stress exponent for buffered samples. When compressed along the [101]c or [011]c axis, the mechanical results for unbuffered samples are similar to those for orthopyroxene (opx) buffered samples. However, when compressed along the [110]c orientation, the creep behaviour of unbuffered samples is substantially different from that of opx-buffered samples. For unbuffered samples compressed along the [110]c axis three power-law relations are required to describe the dependence of strain rate on Tand fo 2 over the full range of experimental conditions. It is proposed that each power-law relation describes the creep behaviour of a different rate-controlling creep mechanism. Fo...
Ellipsometric analyses for an absorbing surface film on an absorbing substrate with or without an intermediate surface layer

Abstract Various ellipsometric analyses have been derived to characterize the optical properties of a single-layer or a double-layer surface film overlaid on a substrate material. The general numerical technique is independent of the method (or methods) used in the series of ellipsometric measurements which provide the raw data. The convergence to unambiguously determined values of the unknown parameters is systematically carried out in the numerical search procedure. Selected examples are presented to illustrate the validity of various analyses and the possible usage of these analyses to optimize the experimental conditions and measurement methods.
Implementation of boundary conditions for meshless methods

Abstract Boundaries and boundary conditions are an aspect of the numerical solution of partial differential equations where meshless methods have had to surmount many initial difficulties due to the lack of a finite-element-like Kronecker delta condition. Furthermore, it is frequently desirable, especially in fluid mechanics, to impose general, nonlinear boundary and interface constraints. This paper describes a computationally efficient algorithm based on d'Alembert's principle that can be used for general constraints both in meshless methods and finite elements. First, a method of partitioning meshless shape functions suitable for imposing linear boundary conditions is developed. Subsequently, an analogous method is developed for nonlinear constraints. Special attention is given to imposing general boundary and fluid-structure interface conditions on the Navier-Stokes equations in terms of conservative variables. Numerical results using d'Alembert's principle with the Reproducing Kernel Particle Method (RKPM), including viscous, supersonic flow past a NACA 7012 airfoil, are shown.
John Edwards Holbrook's Senckenberg plates and the fishes they portray

John Edwards Holbrook (1794–1871), a zoologist residing in Charleston, South Carolina, sent six colour plates of North American fishes to Frankfurt am Main, apparently in 1845. Today those plates are in the collections of the Senckenbergische Bibliothek in Frankfurt. Herein, I comment on the illustrations of the 12 fishes depicted on those plates.
Influence of mitochondrial protein synthesis inhibition on deafferentation—induced ultrastructural changes in nucleus magnocellularis of developing chicks

Following cochlea removal in developing chicks, about 30% of the neurons in the ipsilateral second-order auditory nucleus, nucleus magnocellularis, undergo cell death. Administration of chloramphenicol, a mitochondrial protein synthesis inhibitor, results in a pronounced increase in deafferentation-induced cell death. In this study, we examined whether the chloramphenicol enhancement of deafferentation-induced cell death reveals the same ultrastructural characteristics that are seen in degenerating nucleus magnocellularis neurons after cochlea removal alone. Unilateral cochlea removal was performed on anaesthetized posthatch chicks. One group of animals was simultaneously treated with chloramphenicol. Six, twelve, or twenty-four hours following cochlea removal, n. magnocellularis neurons were studied by routine transmission electron microscopy. Particular attention was paid to the integrity of the polyribosomes and rough endoplasmic reticulum. Two ultrastructurally different types of neuronal degeneration were observed in the deafferented nucleus magnocellularis neurons: an early onset electron-lucent type that always involved ribosomal dissociation and a late-onset electron-dense type displaying nuclear pyknosis and severely damaged mitochondria. The percentage of nucleus magnocellularis neurons displaying ribosomal disintegration following cochlea removal was found to be markedly increased after chloramphenicol treatment. This finding suggests that mitochondrial function is important for the maintenance of a functional protein synthesis apparatus following deafferentation. © 1996 Wiley-Liss, Inc.
Empirical Research on Spirituality and Alcoholism: A Review of the Literature

ABSTRACT The apparent success of Alcoholics Anonymous and its spiritually based program of recovery in 1935 led early researchers to explore how AA worked and ultimately led to more formalized research on alcoholism and spirituality in the latter part of the 20th century. Using Miller's suggested research framework, a review of empirical research was conducted on four roles of spiritual variables in alcohol abuse and recovery. Tentative conclusions about the relationship between alcoholism and spirituality are provided. Limitations of studies are examined and implications for social work research are discussed.
Evaluating the economic damage threshold for bont tick ( Amblyomma hebraeum ) control in Zimbabwe

Controlling ticks and tick-borne diseases by frequent applications of acaricides (e.g., dipping) is costly, and can leave treated livestock vulnerable to epizootics of tick-borne diseases should the system of applying acaricides break down. The concept of only applying acaricides on an infrequent (strategic) basis often relies on the target tick population displaying a seasonal cycle. However, as adult bont tick (Amblyomma hebraeum) infestations in Zimbabwe's lowveld do not have a strictly seasonal pattern of occurrence, it is recommended that tick control only be applied when bont tick infestations are equal to, or greater than, their economic damage threshold. The economic damage threshold is the minimum average weekly standard female tick burden sufficient to cause damage equal in dollar value to the costs of applying tick control. Assuming that each standard female tick represents a 10 gram weight loss, the economic damage threshold (standard female ticks/week) is equivalent to the ratio of the producer price of beef (liveweight equivalent): per head cost of dipping (Eqn (3)). To illustrate the application of the threshold methodology, it was assumed that the producer price of beef was Z$1.63/kg (U.S.$0.33/kg) and that tick control cost Z$0.29/hd/dip (U.S.$0.06/hd/dip). This gave a threshold of 18 standard female ticks/head/week. Using tick counts obtained from 20 Brahman cattle held at Mbizi in southeastern Zimbabwe, it was shown that for the 1988 calendar year there were only 32 weeks when the economic damage threshold was met or exceeded. This is substantially less that the 44 dippings per year that have been, until very recently, legally required in Zimbabwe. Sensitivity analysis showed that a 10% rise in the cost of dipping reduced to 23 (a 28% decrease) the number of weeks when tick burdens exceeded the economic damage threshold. By further assuming that an acaricide application and residual effects will cause a 3–5 week interval before the next application may be required, the number of weeks when the tick burden was equal to or greater than the threshold of 18 standard females/week fell to just 9–12 weeks. Three factors may cause an alteration in the economic damage threshold: i) tick burdens may cause damage to the udders; ii) secondary infestations (e.g., screw-worm) may cause economic damage; and iii) nutritional stress of the cattle may reduce the actual average per tick weight loss. Until further data becomes available, it is recommended that the economic damage threshold methodology be used as described here, and that farmers closely observe their herds during the suggested weekly tick sampling for udder damage and secondary infestations.
Mesoscale modeling of wintertime particulate matter episodes in eastern Washington, USA

Abstract The Spokane, Washington area is classified as a non-attainment area for the 24-h PM 10 standard due to a history of high particulate matter concentrations. A Eulerian regional air quality model (CALMET/CALGRID) has been used to characterize the emission, transport and dispersion of PM 10 and PM 2.5 in Spokane. Observations from a residential site (Rockwood, RW) and an industrial site (Crown Zellerbach, CZ), spanning July 1994–August 1996 were used to evaluate the current emission inventory. Two major tasks were devised to conduct the objectives of this investigation. First, a simple and efficient urban dispersion model (WYNDValley) was used to simulate important episodes characterized by the highest PM 10 and PM 2.5 concentrations. The selected episodes included four days with wet conditions for which no roads would have been emitting and seven days with dry conditions for which roads would emit. In the second step, a single road-emitting event was selected from the previous predicted results for further analysis using the Eulerian regional air quality model to examine the emission inventory. The urban and regional models predicted the observed concentration distributions reasonably well for the source emissions inventoried in Spokane. The mass concentrations of PM 10 were well predicted for the roads emitting case examined by both models indicating that the emission inventory based primarily upon area sources including roads is reasonably well characterized, at least at the RW site. The area sources around CZ are less well characterized, so that the PM 10 concentrations are underpredicted at CZ. The models appear unable to reach an equilibrium mass balance status at the beginning of the simulation, and the urban model seems unable to properly resolve the nocturnal boundary layer.
Saint-Venant's principle for a micropolar helical body

The analog of Toupin's version of Saint-Venant's principle is proved for an isotropic, linear elastic micropolar body of arbitrary length and of uniform cross-section which in the unstressed state is helical. That is, when such a body is loaded by self-equilibrated stresses and couple stresses at one end only, we show that the elastic strain energy stored in the part of the body beyond a certain distance from the loaded end, decreases exponentially with the distance.
Shakedown of unidirectional composites

Abstract The shakedown problem for a composite lamina made of an elastic-plastic matrix and elastic cylindrical fibers is studied. The plastic deformation modes of the lamina are reviewed, and it is concluded that significant shakedown effects can be caused only by the I 1 = 1/2( T 11 + T 22 ) and I 2 = T 33 components of the remotely applied stress field which are symmetric about the axis x 3 of the fiber; T 11 and T 22 are the normal composite stresses in the transverse plane. It is shown that the I 1 I 2 stress system is needed also to represent thermal loads caused by a uniform change of temperature in the composite. Two methods for evaluation of shakedown limits in the I 1 I 2 -plane are described. First, the classical approach involving the determination of parametric families of self-stress fields and the solution of mathematical programming problems is used. Results are presented for selected B - Al , Be - Al , B - Ti and B - Mg composites. In the second method, the shakedown problem is related to the recently developed kinematic hardening rules for fibrous composites. It is shown that the composite will shake down for any loading program within a prescribed domain in the I 1 I 2 -plane, providing that the domain can be contained within a translated initial yield surface. This approach leads to a closed-form evaluation of shakedown limits for any arbitrary combination of mechanical and thermal variable cyclic loads in fibrous composites with temperaturedependent matrix yield strengths. The relationship between shakedown and fatigue in metal matrix composites is discussed.
Performance of tornado wind energy conversion systems

The flow characteristics and power production capabilities of the Tornado Wind Energy Conversion System (TWECS) are examined. Experimental results indicate that the confined vortex in the tower of TWECS rotates approximately as a solid body and only supplements total power production, most of which comes from the tower acting as a bluff body. Wrapped tower experiments were performed by fitting a plastic shroud 360 deg around the tower from the top of the bottom inlet to the tower exit level which transformed the TWECS into a hollow, raised cylinder. Coefficient of power is compared for louvered towers vs. wrapped tower. The fact that the wrapped tower performs as well as the louvered tower suggests that it is the pressure difference between the bottom inlet region and the region above the tower (where the pressure of the ambient flow will be somewhat reduced owing to its acceleration over the bluff body of the tower) which determines the vertical force on the fluid within the tower.
Time Required for Egg Shell Breaking Strength to Equilibrate in Various Moisture Conditions

Abstract Experiments were conducted to determine the time required for egg shell strength to change after the egg had been placed in an environment that would change the moisture content of the shell. In one experiment, eggs were stored in a 12.7° C. environment with 10% relative humidity (R.H.), or 85% R.H., for 3 days; then were moved from storage to a room where moisture condensed on the surface of the eggs. At 0, 5, 10, 15, 20, 30 or 60 minutes after condensation had formed, breaking strength of the shells was measured. The breaking strength of the eggs that had been stored at 10% R.H. changed about 7% in a linear fashion during the first 30 minutes after moisture condensed on the surface of the egg; the breaking strength of the eggs that had been stored at 85% R.H. only changed about 3% during the same time. In another experiment, R.H. of the storage space was changed from 10% to 85% in one trial, and from 85% to 10% in another trial. Breaking strength was determined at 2, 4, 8, 24, 48 and 72 hours after the R.H. change. It was found that egg shell strength reached equilibrium in approximately 24 hours for both conditions.
FIRST DIRECT MEASUREMENT OF THE SPIN DIFFUSION RATE IN A HOMOGENOUS SOLID

The first direct measurement of the rate of spin diffusion through a homogeneous sample is reported. The measurement was performed as an incoherent scattering experiment via a combination of pulsed gradient spin echo methods with multiple pulse, pulsed gradient spatial encoding. The measurement records the destruction of a spin magnetization grating by the random translation of spin magnetization associated with the flip-flop term of the homonuclear dipole-dipole interaction. For single crystal ${\mathrm{CaF}}_{2}$, the measured parallel components of the spin diffusion rates are $7.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}{\mathrm{cm}}^{2}/\mathrm{s}$ along the [001] direction and $5.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}{\mathrm{cm}}^{2}/\mathrm{s}$ along the [111] direction, in good agreement with theoretical predictions.
Influence of gravity on thermocapillary convection in floating zone melting of silicon

It was found that the finite difference equations used by Chang and Wilcox for the fluid adjacent to the free melt surface satisfy only the boundary conditions and not the Navier-Stokes differential equation. A new formulation was made which satisfies both. This eliminated the anomalous additional vortex center in the cell generated by electron bem heating. The influence of gravity was investigated as a function of zone size and temperature gradient at a constant zone travel rate of 5 cm/h with electron-beam heating and zone diameter = zone length. The change in vorticity at the freezing interface depends on Gr6/M, and is proportional to the 52 power of zone diameter and the 34 power of the maximum superheating in the zone.
Functionally gradient bilayer oxide membranes and electrolytes

Abstract In the application of solid oxide electrolytes and membranes to the production of electricity and formation of “value added” products, respectively, the electrolyte or membrane is operated under a severe chemical potential gradient, from air to a hydrocarbon fuel/feed. By taking this functional gradient into consideration, one can design a bilayer electrolyte or membrane that utilizes more highly conductive materials if the effective interfacial PO2 between the two layers is above a certain threshold stability limit. In this paper, we present results on the performance and stability of bilayer electrolytes and membranes. The open circuit potential (OCP) of bilayer electrolytes, with (Er2O3)0.2(Bi2O3)0.3 (ESB) on the high PO2 side and (Sm2O3)0.1(CeO2)0.9 (SDC) on the low PO2 side, was measured and the effect of relative thickness on area specific resistance (ASR) was evaluated. The oxygen permeability and stability of bilayer membranes with La0.6Sr0.4Co0.8Fe0.2O3 (LSCF) on the high PO2 side and SDC on the low PO2 side were measured. The results show that with this approach, higher conductivity materials can be used resulting in higher performing devices.
Sex and gender.

Letters from: [ Ethel Tobach ][1] [ Norman F. Carlin ][1] On the topic of sex and gender, I agree for the most part with G. A. Pearson (Letters, [18 Oct., p. 328][2]) and am happy that the topic is being raised. However, I would suggest that, in discussions of biochemical, morphological, and physiological issues where reproductive hormonal characteristics are being studied, “sex” is the more useful term even when it is applied to humans. In psychological, social, and societal issues, “gender” is more appropriate. # {#article-title-2} Pearson complains that the word “gender” is misused interchangeably with “sex” in the scientific literature. The former is a term of art used by social scientists to refer to human cultural roles, as opposed to physiological sex, and Pearson asserts that to confuse the two is to “perpetuate the myth that biology is destiny.” According to the Oxford English Dictionary , however, “gender” originated as a philological term designating nouns that are masculine, feminine, or neutral. While social scientists are free to appropriate the word to draw a useful distinction within their field, it is not incumbent on the rest of us to do so. Pearson's claim is akin to arguing that, because the word “queen” is a term in social insect biology, the Queen of England no longer qualifies for her title because she does not have an enormous abdomen or spend her days laying eggs. [1]: /lookup/doi/10.1126/science.274.5293.1593e [2]: /lookup/doi/10.1126/science.274.5286.324g
Molecular dynamics of silicon indentation.

We use nonequilibrium molecular dynamics to simulate the elastic-plastic deformation of silicon under tetrahedral nanometer-sized indentors. The results are described in terms of a rate-dependent and temperature-dependent phenomenological yield strength. We follow the structural change during indentation with a computer technique that allows us to model the dynamic simulation of diffraction patterns.
Palatal myoclonus and denervation supersensitivity in the central nervous system

We postulate that palatal myoclonus after infarction of the brainstem or cerebellum, or both, is the manifestation of denervation supersensitivity secondary to lesions involving the dentatorubroolivary system. Two cases of our own and 31 from the English and French literature were analyzed in order to determine the delay between the occurrence of presumed anatomical lesions and the recognition of palatal myoclonus. The intervals varied from 2 to 49 months with the median between 10 and 11 months. The natural history of palatal myoclonus following brainstem infarction seemed consistent with the hypothesis.
Effect of Gaseous Atmosphere on the State of Water in Collagen Influencing Microbial Growth

The effects of CO2 and N2 atmospheres on the thermodynamic state of water influencing microbial response in collagen was studied by generating sorption isotherms by inverse gas chromatography and the static method and calculating thermodynamic parameters of sorption. CO2 atmosphere significantly increase; water sorption by collagen at 25°C, 30°C, and 35°C compared to N2 and He. The average binding energies of collagen were significantly increased by CO2 as shown by larger negative Gibb's free energy (δGs), isoteric enthalpy of sorption (δHs) and entropy of sorption (δSs) values. Water clustering in collagen appeared at a higher water activity (aw) in CO2 gas as compared to N2- and He-treated atmospheres at 25°C, 30°C, and 35°C.
Multi-reflection algorithm for timed statistical coupled noise checking

An algorithm that completely characterizes the coupled noise for a pairwise coupled network with arbitrary lengths and reflection coefficients has been implemented in a coupled noise checking software. In this paper, an overview of the coupled noise methodology is briefly described so that the development of the reflection algorithm can be easily understood. Comparisons of the coupled noise predictor results to the ones obtained from detailed circuit simulation are presented. These results quantify the coupled noise predictor accuracy improvement when the timed noise reflections are included in the total coupled noise calculations and they demonstrate the computational time advantage that this approach has over device level simulations.
Qualitative and quantitative measurements of oligonucleotides in gene therapy: Part I. In vitro models.

Part I of this review has already been presented on methods of processing and purification of crude or raw samples in cell-culture or cell free systems. Part II of the review focuses on the in vivo models of determination of input oligonucleotides in both non-primates and primates. Emphasis has been given to the techniques developed for quantification of oligonucleotides or their metabolites from biological samples including blood, plasma, serum, urine and other tissues.
Parkinson disease: Another player in gene therapy for Parkinson disease

Gene therapies have entered clinical trials for several neurological disorders, most notably Parkinson disease. A study in a nonhuman primate model of Parkinson disease has reported motor deficit improvements following the use of a lentiviral vector to restore extracellular dopamine levels. A clinical trial is now underway to evaluate the effectiveness of this approach in humans.
Investigation of nuclear nano-morphology marker as a biomarker for cancer risk assessment using a mouse model.

The development of accurate and clinically applicable tools to assess cancer risk is essential to define candidates to undergo screening for early-stage cancers at a curable stage or provide a novel method to monitor chemoprevention treatments. With the use of our recently developed optical technology—spatial-domain low-coherence quantitative phase microscopy (SL-QPM), we have derived a novel optical biomarker characterized by structure-derived optical path length (OPL) properties from the cell nucleus on the standard histology and cytology specimens, which quantifies the nano-structural alterations within the cell nucleus at the nanoscale sensitivity, referred to as nano-morphology marker. The aim of this study is to evaluate the feasibility of the nuclear nano-morphology marker from histologically normal cells, extracted directly from the standard histology specimens, to detect early-stage carcinogenesis, assess cancer risk, and monitor the effect of chemopreventive treatment. We used a well-established mouse model of spontaneous carcinogenesis—ApcMin mice, which develop multiple intestinal adenomas (Min) due to a germline mutation in the adenomatous polyposis coli (Apc) gene. We found that the nuclear nano-morphology marker quantified by OPL detects the development of carcinogenesis from histologically normal intestinal epithelial cells, even at an early pre-adenomatous stage (six weeks). It also exhibits a good temporal correlation with the small intestine that parallels the development of carcinogenesis and cancer risk. To further assess its ability to monitor the efficacy of chemopreventive agents, we used an established chemopreventive agent, sulindac. The nuclear nano-morphology marker is reversed toward normal after a prolonged treatment. Therefore, our proof-of-concept study establishes the feasibility of the SL-QPM derived nuclear nano-morphology marker OPL as a promising, simple and clinically applicable biomarker for cancer risk assessment and evaluation of chemopreventive treatment.
Transient cerebral ischemic attacks and neuropsychological deficit

Abstract Patients who experienced carotid distribution transient ischemic attacks (TIA) were administered an extensive neuropsychological battery 2–5 days after the clinical clearing of deficits. Significant impairments were noted on measures of higher cortical functioning, including complex memory, abstract concept formation, perceptual-motor integration, and verbal fluency as compared to both published norms and a control group equated for age and years of education. Results are discussed with regard to the heterogeneity of the TIA population, the relationship of the vascular distribution of the TIA to the observed neuropsychological sequelae, weaknesses in published norms with an aging population, and directions for further research.
Development and operation of a high-throughput accurate-wavelength lens-based spectrometera)

A high-throughput spectrometer for the 400–820 nm wavelength range has been developed for charge exchange recombination spectroscopy or general spectroscopy. A large 2160 mm−1grating is matched with fast f/1.8 200 mm lenses, which provide stigmatic imaging. A precision optical encoder measures the grating angle with an accuracy ≤0.075 arc sec. A high quantum efficiency low-etaloning CCD detector allows operation at longer wavelengths. A patch panel allows input fibers to interface with interchangeable fiber holders that attach to a kinematic mount at the entrance slit. Computer-controlled hardware allows automated control of wavelength, timing, f-number, automated data collection, and wavelength calibration.
Effects of a Tilted Magnetic Field on a Two-Dimensional Electron Gas

$n$-type inverted silicon surfaces were studied to examine properties of a two-dimensional electron gas as well as those properties of silicon itself. The effect of a magnetic field tilted up to \ifmmode\pm\else\textpm\fi{}90\ifmmode^\circ\else\textdegree\fi{} from the normal to the (100) Si surfaces was measured between 1.3 and 4.2\ifmmode^\circ\else\textdegree\fi{}K and up to 90 kOe. The electric field associated with the $n$-type inversion layer quantizes the surface electrons and they behave as a two-dimensional electron gas. It was found that the oscillatory magnetoconductance, due to magnetic quantization into Landau levels, depends solely upon the normal component of the magnetic field with respect to the surface. The observed splitting due to spin appears to be determined by the total magnetic field. The parallel component of the magnetic field was found to have a negligible effect on the surface quantization. The cyclotron mass, measured from the temperature dependence of the oscillation amplitude, is equal to the transverse mass of the electron in silicon and is independent of the tilt angle. The spin splitting can be quantitatively identified at certain angles where the Landau splitting is twice that of the spin splitting. The Land\'e $g$ factor determined in this way was found to be substantially larger than 2 and decreases with the increasing surface electron density. The $g$ factor has values between 3.25 and 2.47 for a surface electron density ranging from 1\ifmmode\times\else\texttimes\fi{}${10}^{12}$ to 6\ifmmode\times\else\texttimes\fi{}${10}^{12}$ ${\mathrm{cm}}^{\ensuremath{-}2}$.
Lipolysis and β-adrenergic receptor binding on adipocytes of spontaneously hypertensive rats

Abstract Adipocytes from spontaneously hypertensive rats demonstrated a blunted lipolytic response to isoproterenol and dibutyryl cyclic AMP. (−)-[3H]Dihydroalprenolol binding was examined in adipocytes from normotensive and spontaneously hypertensive rats. Increasing concentrations of isoproterenol decreased total (−)-[3H]dihydroalprenolol binding to intact cells from normotensive rats, and the efficacy of competition was decreased in adipocytes from spontaneously hypertensive rats. Scatchard analysis indicated that the number of (−)-[3H]dihydroalprenolol binding sites and the affinity of dihydroalprenolol binding were comparable between normotensive and spontaneously hypertensive rats. Isoproterenol- and Gpp(NH)p-stimulated adenylate cyclase activity was consistently depressed in adipocyte membranes from spontaneously hypertensive rats as compared to normotensive rats. No difference in fluoride-stimulated adenylate cyclase activity was observed. The blunted lipolytic and cyclic AMP response to isoproterenol in these cells suggest a postreceptor lesion of the lipolytic pathway (possibly the guanine nucleotide regulatory protein) in adipocytes from spontaneously hypertensive rats. The blunted lipolytic response to dibutyryl cyclic AMP suggests defective regulation of lipolytic enzymes at the protein kinase-hormone-sensitive lipase level.
SU-E-I-85: Application of Real-Time Dosimetry to Characterize the X-Ray Penetrability of CT Scanners

Purpose: Beam quality measurement on commercial whole body CT scanners generally requires the presence of the service engineer to stop the gantry's rotation using a service mode; consequently, the half‐value layer (HVL) is not regularly assessed. An apparatus was constructed and allows for HVL measurements to be performed using a standard axial scan with a prototype real‐time (RT) isotropic dose probe.Method: The HVL apparatus consisted of eight plates of high purity aluminum (type 1100) equally spaced around the probe's detective volume. The thickness of the plates ranged from 0.81 mm to 13.51 mm; the x‐ray beam was attenuated by varying amounts as the gantry rotated. From the acquired signal train, the relative signal of the attenuated beam to the unattenuated beam was used to estimate the HVL. The HVL measurements made with the prototype apparatus were validated against conventional methods on a prototype dedicated breast CT (bCT) scanner over a range of x‐ray tube voltages. The energy dependence of the prototype probe's output was compared to that of an ion chamber. The HVL measurements were then demonstrated on a clinical whole body CT scanner at four discrete x‐ray tube potentials. Results: The energy dependence of the RT probe was found to be non‐linear as compared to the conventional ion chamber, and a calibration factor for the RT solid‐state probe was produced. After converting the probe's signal into units of air kerma, the HVL measurements using the proposed techniques were found to be equivalent to those found using traditional techniques. Conclusions: A proposed new method and apparatus for measurement of the HVL in whole body CT scanners provides for a fast, noninvasive measurement of x‐ray beam quality within a single scan. Using this approach, it is anticipated that HVL measurements across kV settings can be routine in CT scanner evaluation.
Activation of adenosine A1 receptors in the nucleus accumbens impairs inhibitory avoidance memory

Potent and highly selective adenosine A1 and A2 receptor agonists were bilaterally injected into the nucleus accumbens of mice 10 min prior to inhibitory avoidance training. Retention of the inhibitory avoidance response was assessed 24 h after training. Intra-ACB activation of A1 receptors, but not A2a receptor activation, significantly impaired the performance of mice during the subsequent retention test. Furthermore, the retention deficit produced by activation of A1 receptors was significantly attenuated by pretreating mice with a highly selective A1 receptor antagonist. These findings suggest that endogenous adenosine may modulate information processing in the ventral striatum via adenosine A1 receptors.