cssi/SciSciGPT-SciSciNet huggingface dataset:
Atomistic simulations of tension-compression asymmetry in dislocation nucleation for copper grain boundaries

Abstract Atomistic simulations are used to investigate how grain boundary structure influences dislocation nucleation under uniaxial tension and compression for a specific class of symmetric tilt grain boundaries that contain the E structural unit. After obtaining the minimum energy grain boundary structure, molecular dynamics was employed based on an embedded-atom method potential for copper at 10 K. Results show several differences in dislocation nucleation with respect to uniaxial tension and compression. First, the average nucleation stress for all 〈1 1 0〉 symmetric tilt grain boundaries is over three times greater in compression than in tension for both the high strain rate and quasistatic simulations. Second, partial dislocations nucleate from the boundary on the {1 1 1} slip plane under uniaxial tension. However, partial and full dislocations nucleate from the boundary on the {1 0 0} and {1 1 1} slip planes under uniaxial compression. The full dislocation nucleation on the {1 0 0} plane for boundaries with misorientations near the coherent twin boundary is explained through the higher resolved shear stress on the {1 0 0} plane compared to the {1 1 1} plane. Last, individual dislocation nucleation mechanisms under uniaxial tension and compression are analyzed. For the vicinal twin boundary under tension, the grain boundary partial dislocation is emitted into the lattice on the same {1 1 1} plane that it dissociated onto. For compression of the vicinal twin, the 1/3〈1 1 1 〉 disconnection is removed through full dislocation emission on the {1 0 0} plane and partial dislocation emission parallel to the coherent twin boundary plane, restoring the boundary to the coherent twin. For the Σ 19 boundary, the nearly simultaneous emission of numerous partial dislocations from the boundary result in the formation of the hexagonal close-packed (HCP) phase.
Reflex venomotor activity in normal persons and in patients with postural hypotension.

Reflex venomotor activity has been observed and measured in normal subjects by means of the pressures developed within isolated segments of superficial veins. Strong contractions are caused by the Valsalva maneuver, tilting, cold, exercise, and hyperventilation. After the Valsalva and after tilting there is a brief elevation of central venous pressure. Pulmonary vascular pressures are also increased after the Valsalva. This is taken to indicate a widespread venoconstriction with central shifting of blood. Persons with postural hypotension show little or no segment or central venous pressure response to these stimuli, indicating impaired reflex venomotor activity.
Mutual translational diffusion coefficients in bovine serum albumen solutions measured by quasielastic laser light scattering

Abstract Concentration dependence of the translational diffusion coefficient of monomeric bovine serum albumen has been studied in three particular aqueous solvent systems. Two concentration series at ionic strength I = 0.15 and pH 7.4, and I = 0.10 and pH 4.7, respectively, extended to volume fractions φ ∼ 0.3. These data and literature data are discussed with regard to recent theoretical treatments of hard-sphere diffusion. The importance of including the effect of an appropriate screened coulombic potential in modeling protein diffusion is emphasized. The data are regarded as strong quantitative support for the theoretical treatment by Anderson and Reed [ J. Chem. Phys. 64, 3240 (1976)] of macromolecular diffusion when interparticle interactions are repulsive in nature. A third set of experiments investigated the concentration dependence of D t in salt-free serum albumen solutions at the isoionic point where strong attractive electrodynamic forces are present. These data are in qualitative agreement with theoretical prediction but quantitative discrepancies are found.
A matrix-T approach to the sequential design of optimization experiments

A new approach to the sequential design of experiments for the rapid optimization of multiple response, multiple controllable factor processes is presented. The approach is Bayesian and is based on an approximation of the cost to go of the underlying dynamic programming formulation. The approximation is based on a matrix T posterior predictive density for the predicted responses over the length of the experimental horizon that allows the responses to be cross-correlated and/or correlated over time. The case of an unknown variance is addressed; the assumed models are linear in the parameters but can be nonlinear in the factors. It is shown that the proposed approach has dual-control features, initially probing the process to reduce the parameter uncertainties and eventually converging to the desired solution. The convergence of the proposed method is numerically studied and convergence conditions discussed. Performance comparisons are given with respect to a known-parameters controller, the efficient globa...
CEBPA resembles Roman god Janus.

In this issue of Blood, Ho and colleagues report the independent predictive value of single gene mutations in the CEBPA gene in pediatric acute myeloid leukemia. The outcome for this group of patients was excellent with 83% (± 13%) overall survival at 5 years from study entry.
Archimedean spiral design for extremely stretchable interconnects

Abstract The island-interconnect structures have been widely used in stretchable electronics. This Letter compares the stretchability of two serpentine-based and one spiral-based interconnects, under the limitations of the same in-plane area and contour length rooted from the same areal coverage and electrical resistance. Finite element analysis was conducted and the results showed that the spiral-based interconnects are more stretchable (up to 250% under elastic deformation) than serpentine-based structure. It is believed that a uniform and small curvature contributes to a greater stretchability. The Archimedean spiral pattern as the stretchable interconnection only presents one successful example of the new design concept.
Fluid simulation of a low-pressure axisymmetric toroidal plasma using natural coordinates

Abstract A numerical model is developed to study the confinement of low-pressure plasmas in axially symmetric configurations with arbitrary shaped magnetic surfaces. The equations contain the effects of resistivity, plasma inertia, and pressure gradients in the surfaces. In this model, which extends the earlier work in which fictitious currents had to be introduced to support the magnetic fields, the plasma pressure is taken sufficiently small that only electrostatic modes can be excited. The Lax-Wendroff scheme is used to advance the plasma density and velocities in time. Applications include demonstration that classical expressions for diffusion are valid when there are small plasma flows, and study of the propagation of acoustic and geodesic waves in levitrons.
Design and implementation of scalable continuous media servers

Abstract During the past decade, the information technology has evolved to store and retrieve continuous media data types, e.g., audio and video clips. Unlike the traditional data types (e.g., text), continuous media consists of a sequence of quanta, either audio samples or video frames, that convey meaning when presented at a pre-specified rate. A challenging task when implementing these servers is to guarantee retrieval and delivery of a clip at its pre-specified rate. Continuous media servers are expected to play a major role in many application domains including library information systems, entertainment technology, educational applications, etc. The focus of this study is on the disk subsystem of a server and techniques that both enhance its performance and ensure its scalability. By scalable, we mean that the system can grow incrementally as the requirements of an application grows in order to avoid a degradation in performance. This study details data placement techniques across both (1) the zones of a disk in order to trade bandwidth for storage, and (2) multiple disks to enable the system to scale. In addition, we describe scheduling techniques to (1) trade memory for disk bandwidth and vice versa, and (2) merge multiple requests referencing a single clip in order to increase the number of simultaneous displays supported by the system. We present performance results from Mitra, an experimental prototype that realizes an implementation of the presented techniques. These results demonstrate the feasibility of a scalable server.
Thermochemical plumes and mantle phase transitions

Integral relations based on boundary layer theory are derived to study the motion of an isolated, two-dimensional thermal plume through a viscous mantle containing polymorphic phase changes. Analytical results are obtained which show that phase transitions alter average mantle convective velocities by less than 50%. In particular we find that the olivine-spinel transition, approximated as univariant, can enhance the circulation velocity of upper mantle convection by 30–40%, while it can enhance the overall amplitude of whole mantle convection by a few percent only. Our calculations demonstrate that a possible endothermic phase change located at 650 km will not prevent deep mantle convection unless the Clapeyron slope defining the transition exceeds −0.3 kbar/°K. This large value is more than one order of magnitude greater than what has been proposed for the 650-km discontinuity. We then extend the method to include compositional buoyancy and effects of the divariant nature of the olivine-spinel transition. Analysis of the motion of a compositionally buoyant plume (one having an anomalous Mg/Fe ratio relative to the ambient mantle) reveals that the chemical plume locally distorts the transition in a way which contributes buoyancy and enhances convective amplitudes by 10% or less. Finally, we combine thermal and compositional buoyancy to investigate the interaction between a thermochemical plume and a compositionally induced density interface. The results are used to determine the stability criterion for two-layered mantle convection. We find that a compositionally produced density increase of 4% at 650 km is needed to prevent mixing between the upper and lower mantle. Seismological observations indicate that density jump at the 650-km discontinuity is between 5% and 9%. If all the density increase observed there is due to change in composition, then two-layered mantle convection is stable. However, if phase transitions account for part of the density increase, so that the chemically produced component is less than 4%, then two-layered mantle convection may be unstable.
Non-chemically amplified 248-nm resist materials

Remarkable progress has been made in the formulation of chemically amplified resists for deep-UV (DUV or 248 nm) lithography. These materials are now in general use in full scale manufacturing. One of the deterrents to rapid and universal adoption of DUV lithography has been the combination of high cost of ownership and a narrow process latitude when compared to conventional i-line process alternatives. A significant part of the high cost of the DUV process is associated with installing and maintaining special air handling equipment that is required to remove basic contaminants from the ambient. Manufacture process latitude demands this special air handling. The chemically amplified resists were developed originally to support mercury lamp powered exposure systems. The sensitivity realized by chemical amplification is required to enable useful productivity with such systems that generate very little DUV flux at the wafer plane. With the advent of high powered excimer laser based illumination systems for 248 nm steppers and step-and-scan systems, it is appropriate to re-examine the applicability of non-chemically amplified DUV resist systems. These systems are less sensitive but have the potential to offer both lower cost of ownership and improved process latitude. A series of photoactive compounds (PACs) have been synthesized and auditioned for use in the formulation of a non-chemically amplified 248 nm resist. The most promising of these materials are analogs of 3-oxo-3-diazocoumarin. This chromophore displays photochemistry that is analogous to that of the diazonaphthoquinones (DNQ) that are the basis of i-line resist formulations, but it bleaches at 248 nm. Several structural analogs of the chromophore have been synthesized and a variety of ballast groups have been studied with the goal of enhancing the dissolution inhibition properties of the molecule. The diazocoumarin PACs have been formulated with customized phenolic resins that were designed to provide the combination of optical transparency, dry etch resistance and the dissolution characteristics that are required for manufacturing applications. The resins are copolymers of poly(4-hydroxystyrene) and blends of these polymers with novolac.
Comparative toxicity and biotransformation of lindane in C57BL/6 and DBA/2 mice.

Abstract DBA/2 mice, previously identified as “unresponsive” to aromatic hydrocarbons which induce microsomal enzymes in C57BL/6 mice, are more vulnerable to the convulsant effect of repeated doses of lindane than similarly treated C57BL/6 mice. Death in convulsions and higher blood and brain lindane concentrations indicate that less efficient disposition of lindane itself accounts for the greater vulnerability of the DBA/2 mice. The same two principal chlorophenolic metabolites of lindane were identified in the blood and tissues of both strains, but the time-courses of blood concentrations in response to repeated lindane dosing were different.
Teachers' ratings of aggression and students' own perceived status.

The purpose of this study was to investigate the self-perceived status of students (N = 48) rated by their teachers as high and low in aggressive behavior on an 8-item modified version of the Devereaux School Behavior Rating Scale. In Grades 2, 3, and 4, 4 boys and 4 girls rated low in aggression and 4 boys and 4 girls rated high in aggression by their teachers were randomly selected. A significant interaction of grade by aggression indicated differences in perceived status depending on grade and teachers' ratings of aggression. Students in Grades 2 and 3 who were rated high in aggression perceived themselves as more popular, but those in Grades 4 and 5 so rated perceived themselves as less popular.
Desmoplastic fibroma of the pediatric cranium: case report and review of the literature.

Purpose Desmoplastic fibromas are primary bone tumors that seldom occur in the cranial bones. Furthermore, reports of desmoplastic fibromas of the skull in children are exceedingly rare. Although desmoplastic fibromas are histologically benign, they are locally aggressive and have a propensity to reoccur. Their radiographic appearance may mimic other more common central nervous system and bone neoplasms. There are only 19 reported cases of desmoplastic fibroma of the cranium in the literature, and only seven occurred in the pediatric age group. We present a case report of an 11-year-old female patient with a desmoplastic fibroma of the parieto-occipital region and review the literature.
Rare Heavy Flavor Decays at DØ

Experiments have shown excellent agreement between the observed FCNC in the charm sector and SM predictions involving downtype quarks with charge -1/3. However, certain models, such as SUSY R parity violation in a single coupling scheme, or a little higgs model with a new up-type vector quark, allow deviations from the SM only in the up sector. These types of scenarios motivate a search for the rare decay c → uμμ via D → πμμ. The search for D → πμμ uses about 1 fb of data. The strategy for this search is to first look for the resonant decays D s → φπ+ → π μμ and D → φπ+ → πμμ, then exclude the φmass region and look for continuum decay of D → πμμ. The D S is expected to decay 100% of the time through the resonant decay of a φ meson. Backgrounds are reduced using five criteria: (1) the Isolation defined as ID = p(D)/ ∑
Phytase production by Aspergillus ficuum on semisolid substrate

Phytase production byAspergillus ficuum was studied using solid state cultivation on several cereal grains and legume seeds. The microbial phytase was used to hydrolyze the phytate in soybean meal and cotton seed meal. Wheat bran, soybean meal, cottonseed meal and corn meal supported good fungal growth and yielded a high level of phytase when an adequate amount of moisture was present. The level of phytase production on solid substrate was higher than that obtained by submerged liquid fermentation. Higher levels of phosphorus (more than 10 mg Pi/100 g substrate) in the growth medium (static culture) inhibited phytase synthesis, and the degree of phosphorus inhibition was less apparent in semisolid medium than in liquid medium. A static cultivation on semisolid substrate produced a higher level of phytase (2-20-fold) than that obtained by agitated cultivation. The minimal amount of water required for growth and enzyme production on those substrates was about 15%, while the optimum level for phytase production was between 25 and 35% and that for cell growth was above 50%. Optimum pH for phytase production was between 4 and 6.A ficuum grew well on raw (unheated) substrate containing a minimal amount of water and produced as much phytase as on heated substrate. About half of the phytic acid in soybean meal and cottonseed meal was hydrolyzed by treatment withA. ficuum phytase.
Production and characterization of erythropoietic protoporphyric heterodimeric ferrochelatases.

Mutations resulting in diminished activity of the dimeric enzyme ferrochelatase are a prerequisite for the inherited disorder erythropoietic protoporphyria (EPP). Patients with clinical EPP have only 10% to 30% of normal levels of ferrochelatase activity, and although many patients with EPP have one mutant allele and one “low-expression” normal allele, the possibility remains that, for some, low ferrochelatase activity may result from an EPP mutation that has an impact on both subunits of the wild-type/mutant heterodimer. Here we present data for 12 ferrochelatase wild-type/EPP mutant heterodimers showing that some mutations result in heterodimers with the residual activity anticipated from individual constituents, whereas others result in heterodimers with significantly lower activity than would be predicted. Although the data do not allow an a priori prediction of heterodimeric residual activity based solely on the in vitro activity of EPP homodimers or the position of the mutated residue within ferrochelatase, mutations that affect the dimer interface or [2Fe-2S] cluster have a significantly greater impact on residual activity than would be predicted. These data suggest that some EPP mutations may result in clinically overt EPP in the absence of a low-expression, wild-type allele; this is of potential significance for genetic counseling of patients with EPP.
Isolation of the male germ unit: organization and function in tobacco (Nicotiana tabacum L)

Sperm cells are released from pollen tubes of tobacco as linked cells, associated with the vegetative nucleus in an assemblage known as the male germ unit (MGU). Using light microscopy, the MGU assemblage appears to be ensheathed by cytoplasmic material of the pollen tube, which may stabilize their association. Following their release, the shape of the sperm cells and vegetative nucleus changes from an ellipsoidal to a more spheroidal morphology. When most of the cytoplasmic material is dispersed, a boundary remains around the two sperm cells. Using scanning electron microscopy, the cytoplasmic material surrounding the MGU appears filamentous, sometimes twisted and rope-like. Based on these observations, the function of the MGU of tobacco is discussed.
A remark on the bifurcation diagrams of superlinear elliptic equations

We prove a formula relating the index of a solution and the rotation number of a certain complex vector along bifurcation diagrams.
Regulation of Synaptic nlg-1/Neuroligin Abundance by the skn-1/Nrf Stress Response Pathway Protects against Oxidative Stress

The Nrf family of transcription factors mediates adaptive responses to stress and longevity, but the identities of the crucial Nrf targets, and the tissues in which they function in multicellular organisms to promote survival, are not known. Here, we use whole transcriptome RNA sequencing to identify 810 genes whose expression is controlled by the SKN-1/Nrf2 negative regulator WDR-23 in the nervous system of Caenorhabditis elegans. Among the genes identified is the synaptic cell adhesion molecule nlg-1/neuroligin. We find that the synaptic abundance of NLG-1 protein increases following pharmacological treatments that generate oxidative stress or by the genetic activation of skn-1. Increasing nlg-1 dosage correlates with increased survival in response to oxidative stress, whereas genetic inactivation of nlg-1 reduces survival and impairs skn-1-mediated stress resistance. We identify a canonical SKN-1 binding site in the nlg-1 promoter that binds to SKN-1 in vitro and is necessary for SKN-1 and toxin-mediated increases in nlg-1 expression in vivo. Together, our results suggest that SKN-1 activation in the nervous system can confer protection to organisms in response to stress by directly regulating nlg-1/neuroligin expression.
SELECTIVE PHOTOOXIDATION OF THIOLS SENSITIZED BY AQUEOUS SUSPENSIONS OF CADMIUM SULFIDE

-Finely powdered cadmium sulfide in aqueous, air-saturated, phosphate buffered suspension sensitizes the photooxidation of cysteine to cystine with good efficiency; several additional thiols and inorganic sulfides are also photooxidized. The other amino acids (histidine, methionine, tryptophan, tyrosine) known to be rapidly photooxidized with typical organic photosensitizers are photooxidized only very slowly. The quantum yield of oxygen uptake during cysteine photooxidation is pH dependent with a maximum (0.021) at pH 9.5; the yield is not increased in D2O and is not decreased appreciably by sodium azide, suggesting that singlet oxygen is not involved in the photooxidation process. The slow rate of photooxidation of histidine, which is known to react efficiently with singlet oxygen, also suggests that little if any singlet oxygen is produced by illuminated cadmium sulfide. Superoxide dismutase inhibits the yield of cysteine photooxidation to a maximum of approximately 50%, suggesting the partial involvement of superoxide in the reaction mechanism. The quantum yields of the photooxidation of cysteine, ethylenediaminetetraacetate and inorganic sulfides decrease as the wavelength of the exciting light is increased. Yeast alcohol dehydrogenase, a sulfhydryl enzyme, is inactivated by photodynamic treatment with cadmium sulfide; lysozyme, which has no free sulfhydryl groups, is not.
Rhenium and rhenium oxide as buffer layers for high Tc thin films on metallic substrates

Abstract High T c superconductor films on metal wires for high power applications must show long-term stability. Suitable buffer layers are required to prevent interaction between the superconductor thin films and the substrate, and to improve the long-term stability. A high melting-point metal, rhenium, and its oxide, were sputter deposited on the metallic substrate, Hastelloy. The study showed that rhenium thin films were resistant to out-diffusion from the Hastelloy substrates. However, it was found that they are easily oxidized at high temperature and they are, therefore, not suitable to oxygen rich high T c superconductors like YBCO. They might work with other types of high T c superconductors which have a lesser oxygen dependence.
Spectrophotometric investigation of products formed following the initial one-electron electrochemical reduction of nicotinamide adenine dinucleotide (NAD+)

On electrolysis of NAD+ in aqueous solution at a potential corresponding to the initial one-electron reduction of NAD+ to a free radical, a greenish-yellow color appears which fades when electrolysis is complete. Literature ultraviolet absorption data for the resulting dimer show considerable variation. When the electrolysis is conducted in darkness, the colored product has epsilon 340 of approx. 5700 M-1 . cm-1 and epsilon 259 of approx. 31000 M-1 . cm-1. On ultraviolet and visible illumination, the color disappears, the 340-nm peak decreases and the 259-nm peak increases. On only visible illumination, the color disappears, both peaks increase, the dimer's polarographic oxidation wave decreases and the wave due to 1-substituted nicotinamide reduction increases. The data suggest that the dimer decomposes to NAD+ and 1,4-NADH.
Pardaxin induces aggregation but not fusion of phosphatidylserine vesicles.

The effects on membranes of pardaxin, an amphipathic polypeptide, purified from the gland secretion of the Red Sea Moses sole flatfish Pardachirus marmoratus are dose-dependent and range from formation of voltage-gated, cation-selective pores to lysis. We have now investigated the interactions of pardaxin with small unilamellar liposomes. Light scattering showed that pardaxin (10−7–10−9M) mediated the aggregation of liposomes composed of phosphatidylserine but not of phosphatidylcholine. Aggregation of phosphatidylserine vesicles was impaired by vesicle depolarization. Furthermore, pardaxin-mediated aggregation between fluorescent-labeled PS vesicles was accompanied by leakage of the vesicle contents, and not by fusogenic process within the aggregates. We suggest that pardaxin is a unique polypeptide, that induces vesicle aggregation and membrane destabilization, but not membrane fusion; the mechanism of the aggregation activity of pardaxin is related to its amphipathic properties.
Factors Considered Important in Decision Making: A Preliminary Investigation:

Four groups of educational decision makers rated the influence of nine pieces of information on the decisions they made about the educational placement of a child. Information regarding the sex, socioeconomic status (SES), and physical attractiveness of the student was seen as having an insignificant effect on decisions. Assessment data were believed to have a greater influence, with achievement and intelligence scores seen as having a significant effect. These results are reviewed in light of the finding that child characteristics such as sex, SES, and attractiveness did influence actual decisions made by one of the groups included in this study.
A proposed method for calculating stream‐flow

In recent studies of stream-flow determination from rainfall-records much emphasis has been placed on antecedent weather. The soil-moisture deficiencies that occur on a watershed as a result of weather preceding rainfall could be rather closely estimated if the amount of moisture lost by evaporation and transpiration between storms were known. Instruments designed to secure measurements of such losses are only now being perfected [see 5 of “References” at end of paper] and it was in anticipation of them that a proposed method has been developed for calculating contributions of runoff to stream-flow by reference to soil-moisture deficiencies at the beginning of rainfall. The details of the method are tentative. Only a brief outline of the procedure and of the results obtained is therefore presented in this paper.
High sensitivity focus failure monitoring by using CD-SEM

• Multi-regression analysis realize a focus prediction model with several CD data that have a unique behavior to focus • The focus prediction model detected focus failure in an actual CD-SEM production data • The model built on CD-SEM data could show focus prediction error caused by dose value. But keeping a independency of explanatory valuables was proposed to prevent the error.
Human Herpesvirus 6 Infection after Hematopoietic Cell Transplantation: Is Routine Surveillance Necessary?

Human herpesvirus 6 (HHV6) may be an important pathogen following allogeneic hematopoietic cell transplantation (HCT). We prospectively evaluated weekly HHV6 viremia testing after allogeneic HCT using a quantitative polymerase chain reaction (PCR)-based assay. HHV-6 viremia was detected in 46 of 82 (56%) patients at a median of 23 days post-HCT (range: day +10 to +168). More males (65% vs females 39%, P = .03) and recipients of umbilical cord blood (UCB 69% vs unrelated donor [URD], 46% vs sibling donor [20%] grafts, P = 0.01) reactivated HHV-6. Patients with HHV6 viremia had more cytomegalovirus (CMV) reactivation (26% vs 5.5%, P = .01) and unexplained fever and rash (23.9% vs 2.7%, P = .01) compared with patients without HHV6 viremia. High-level HHV6 (≥25,000 copies/mL) versus lower levels were associated with more culture-negative pneumonitis (72.7% vs 22.8%, P = .01). Twenty HHV6-positive patients were treated with foscarnet, ganciclovir, or cidofovir for HHV6 or other coexistent viruses. Within 2 weeks, HHV6 viremia resolved more commonly in treated (65%) than untreated patients (31%), P = .02. Survival at 3 months was similar in treated and untreated patients (90% vs 81%, P = .4). Survival at 3 and 6 months post-HCT were not affected by HHV6 positivity (3 months HHV6+ 85% vs 78%, P = .46; 6 months HHV6+ 70% vs 72%, P = .89) or by HHV6 level (3-month high level 73% vs 89%, P = .23; 6-month high level 64% vs 71%, P = .54). Neither the occurrence of HHV6, degree of viremia, nor use of antiviral drugs influenced short-term survival after HCT.
AN EROSION MECHANISM FOR NON-LINEAR INSTABILITY IN THE AXIAL MODES OF SOLID PROPELLANT ROCKET MOTORS,

Abstract : Acoustic instability in a solid fuel rocket engine arises from the interaction of sound waves with the burning propellant. An interesting non-linearity arising from acoustic erosivity is investigated, i.e., the dependence of the burning rate on the magnitude (but not the direction) of the fluctuating gas velocity parallel to the transpiring surface. This non-linearity is of first order in the acoustic amplitude, and so can be significant even when higher-order effects are negligible. A simple calculation of the stability in axial modes is presented to illustrate the phenomenon, and it is shown, for example, that a motor stable at low acoustic amplitudes can be unstable at moderate amplitudes due to the non-linearity of erosion. (Author)
Dynamic Stability of an Isentropic Shear Layer in a Statically Stable Medium

Abstract Two theoretical models of shear layers in the atmosphere are examined. The conditions for their dynamic stability are found and their predictions of wavelength to layer-thickness ratio are compared with classical models and with available observational data. Although the models are only rigorously applicable to in-compressible fluids, it is suggested that they also represent conditions in the atmosphere, and clear-air returns published by Katz from the high-power pulse radar at Wallops Island are especially emphasized. Model 2 appears to be able to account for the narrow band characteristic of many of the observed events and also to explain better than other models the observed wavelength to layer-thickness ratios.
Vacuum-ultraviolet emission from rare-gas impurities in alkali metals.

Photon emission spectra from the ${\mathit{np}}^{5}$(n+1)s\ensuremath{\rightarrow}${\mathit{np}}^{6}$ transitions of core-excited Kr (n=4) and Xe (n=5) impurities in host alkali metals are reported. A band arising from the decay of single rare-gas atoms is identified, as well as features characteristic of interaction between neighboring impurity atoms. Lifetimes determined from emission intensities relative to the analogous core excitation in the host metal were found to be roughly constant at \ensuremath{\sim}5 meV in all the alloys studied. The Lorentzian component of the emission edge is considerably wider at almost 200 meV. These model systems have previously been studied in absorption where an anomalously broad and suppressed Fermi edge was found, in contrast to the predicted ``x-ray-edge'' singularity. Emission results for isolated impurities show small overlap with the corresponding absorption edges, and the usual mirror symmetry of the two edges is entirely absent. The effect of configuration interaction is discussed as a possible explanation for the anomalous absorption threshold, rather than shakeup from conduction-electron recoil as previously supposed.
Comparisons of concurrent tracking on various hypercubes

The concurrent multi-target tracking code is ported to and run on the Intel iPSC and Ncube hypercubes. The (minor) difficulties in this porting are noted. The biggest single problem in running the tracking program is found to be the rather limited node memories on the iPSC and Ncube machines. Timing results for the analysis of a sample threat on the iPSC, Ncube and Mark-III hypercubes are presented. The relative performances of the various machines are found to be consistent with prior expectations. A fairly large sample scenario is investigated using 4 through 8-dimensional Ncube configurations, and variations of Ncube performance for differing levels of CrOS porting are examined. Initial results of running the tracking program on the BBN Butterfly are also presented.
Drug-induced stimulus control and the concept of breaking point: LSD and quipazine.

Discriminative stimulus control was established in rats (N = 12) with LSD (100 microgram/kg) and saline using a two-lever response choice task and an FR10 schedule of water reinforcement. Subjects were then tested once per week with either LSD or quipazine (3 mg/kg) and every other week the test ratio was doubled, i.e., each drug was tested at ratios of 10, 20, 40, and 80. In contrast with LSD, which maintained stimulus control at all ratios, LSD-appropriate responding following quipazine declined significantly at FR80. In addition, five of eight subjects tested with quipazine failed to complete the FR80 in 15 min. In subsequent experiments, the breaking point, here defined as the number of LSD-appropriate responses prior to emission of ten responses on the saline-appropriate lever, was determined for LSD and for quipazine. Mean values (N = 12) for LSD and quipazine were 161 +/- 28 and 65 +/- 19, respectively.
Surface characterization and adhesion analysis for polysilicon micromachined flaps

Due to the relatively high compliance, large surface-to-volume ratio, and small separation distances, micromachined polycrystalline silicon (polysilicon) structures are susceptible to high adhesion forces including van der Waals, electrostatic, and capillary forces. Since these forces depend on the surface separation distance, it is essential to understand the microtribological properties, especially the surface roughness. In this study, four types of polysilicon microhinged flaps were designed to characterize the surfaces. The flaps enable access to both the top and bottom surfaces of the structural polysilicon layers. Multiple locations are scanned for each surface type using a Digital Instruments 3100 atomic force microscope (AFM). The results indicate that the top surface is much rougher than the bottom surface for structural layers and the roughness is influenced by the adjacent layers. Since the base polysilicon layer (poly0) is six times rougher than a base silicon nitride layer, depositing the MEMS devices on the poly0 layer rather than directly on silicon nitride will reduce adhesion. An adhesion model was used to analyze the effect of roughness parameters on stiction force between structural layers and substrate. Since the tip condition impacts the accuracy of AFM measurement, a wear test of silicon tips was also performed.
13C−1H and 13C−13C Spin Couplings in [2‘-13C]2‘-Deoxyribonucleosides: Correlations with Molecular Structure

2`-Deoxyribonucleosides (2`-deoxyadenosine (1), 2`-depoxycytidine (2), thymidine (3)) singly enriched with {sup 13}C at C2` have been prepared and used to obtain one-, two-, and three-bond {sup 13}C-{sup 1}H and {sup 13}C-{sup 13}C spin-coupling constants involving C2`. Spin couplings in 1-3 involving C1` and C2`are also compared to corresponding values in ribonucleosides in order to assess the effects of nucleoside structure and conformation on J values within the furanose ring. {sup 1}J{sub C2`,H2`R} and {sup 1}J{sub C2`,H2`S} in 1-3 and {sup 1}J{sub C2`,H2`} in ribonucleosides depend on C-H bond orientation: {sup 1}J{sub C1`,H1`} in 1-3 and in ribonucleosides exhibits a similar dependence. The latter couplings appear to be essentially unaffected by N-glycoside torsion. {sup 1}J{sub CC} values depend on the number and distribution of electronegative substituents on the C-C fragment. A modified projection curve is proposed to aid in the interpretation of {sup 2}J{sub C2`,H1`} values; the presence of N substitution at C1` caused a shift to more negative couplings relative to the O-substituted analog. In contrast, {sup 2}J{sub C1`,H2`} is essentially unaffected by the same change in the electronegative substituent at C1`. {sup 2}J{sub CC} values within the furanose ring are determined buy two coupling pathways; in one case (i.e.,more » {sup 2}J{sub C1`,C3`}), the observed coupling is shown to be the algebraic sum of the two couplings arising from each pathway. 41 refs., 4 figs., 2 tabs.« less
Analytic Model for the Diffusant Concentration in Ceramic Green Bodies During Diffusion-Controlled Thermal Binder Removal

The diffusion of the decomposition product of binder degradation has been modeled using the diffusion equation when a source term is present. An analytic solution to the governing nonlinear, unsteady-state partial differential equations has been obtained for a planar body with two simplifications. The first approximation utilizes the pseudo-steady-state approximation whereas the second approximates the diffusivity, as given by the free volume theory, in terms of a single temperature-dependent parameter. The analytic solution, which was compared to numerical solutions to establish the range of model validity, accurately describes the temporal and spatial distribution of the binder decomposition product during most of the heating cycle, especially when the concentration in the green body is the highest. The functional dependence of concentration within the body is established in terms of model parameters including the body size, degree of nonlinearity of the diffusivity, and the ratio of reaction rate to diffusivity.
Privileging masculinity in the social construction of Basque identity

Following a framework developed by Susan Gal and Judith Irvine (1995), this article illustrates how Basque-medium schools promulgate an androcentric vision of the Basque nation. First, male privilege is upheld in textbooks through the erasure of women's contributions to Basque language and culture, so that men appear as the quintessential Basque speakers and cultural agents. Secondly, language ideologies about Spanish and Basque recursively construct Basque ethnic identity is such a way that it centres on vernacular Basque, whose primary marker is a second person pronoun, ‘hi’, which indirectly indexes male speakers and masculinity. An iconic relationship is thereby created between authentic Basque identity, Basque culture, Basque linguistic forms and masculinity. However, I also show that women have challenged this male privilege in various domains, thereby opening up the possibility of a Basque nation that embraces its female as well as its male members.
Chip-based P450 drug metabolism coupled to electrospray ionization-mass spectrometry detection.

A chip-based P450 in vitro metabolism assay coupled with ESI-MS and ESI-MS/MS detection is described in this paper. The chips were made of a cyclic olefin polymer using a hot embossing process. The introduction of reagent solutions into the chip was carried out using fused-silica capillaries coupled to two syringes with the flow rate controlled by a syringe pump. Initial experiments described here employed a small commercial guard column in an off-chip format to desalt and concentrate the products of the enzymatic reaction prior to ESI-MS analysis. The system was used both to yield the Michaelis constant (Km) of the P450 biotransformation of imipramine into desipramine and to determine the IC50 value of a chemical inhibitor (tranylcypromine) for this CYP2C19-mediated reaction. The results demonstrated that the kinetics of the reaction inside the 4-μL volume within the channels of the cyclic olefin polymer chip provided results in agreement with those reported in the literature using conventional assays. T...
State legislators' perceptions of lobbyists and lobbying on tobacco control issues.

OBJECTIVE: To determine state legislators' perceptions about health and tobacco lobbyists, their frequency of contact with these lobbyists, and the amount of campaign contributions from health professional organisations and the tobacco industry. DESIGN: Cross-sectional study. SUBJECTS: State legislators from North Carolina, Texas, and Vermont (USA), serving in 1994. MAIN OUTCOME MEASURES: Perceptions about lobbyists representing the tobacco industry, non-profit health organisations, and state medical societies with respect to their credibility, importance as sources of information, and persuasiveness; extent of lobbying activities; campaign contributions from health professional organisations and the tobacco industry. RESULTS: Almost all legislators reported that medical society and non-profit health organisation lobbyists are credible on tobacco issues and just over half believed that these lobbyists are important sources of information. More legislators said they could be persuaded by medical and health lobbyists than by tobacco lobbyists. Although health professional Political Action Committees (PACs) gave campaign contributions to more state legislators, and gave higher amounts on average, than tobacco PACs, legislators reported less contact with medical society lobbyists than tobacco lobbyists about tobacco issues. CONCLUSIONS: State legislators have positive attitudes toward lobbyists for non-profit health organisations and state medical societies regarding tobacco issues. These groups may be an underused resource for educating legislators about tobacco control measures.
Design considerations for large MEMS

There has been an increasing need for the design and fabrication of large (few millimeters) MEMS made of micron-size features for a variety of applications. Mechanical design of large MEMS structures needs careful consideration of the forces developed during and after processing to ensure their survivability and reliable performance. forces generated to actuate a device, e.g., capacitive force, are well characterized. However, the forces developed due to conditions of processing, such as fluid forces, have not yet been fully characterized. In this paper, we propose simple models to estimate thermal and intrinsic stresses and the corresponding deformations of large MEMS, as well as fluid forces during wet processing. We also discuss the issue of stability of large MEMS during actuation.
Pulmonary vascular resistance index and mortality after paediatric heart transplant

Background Although some prior studies have provided evidence to question the historical belief that pulmonary vascular resistance index ⩾6 Wood Units×m2 should be a contraindication to heart transplantation in children, no national analyses specific to the modern area have addressed this question. Methods Data were analysed for paediatric heart transplant recipients from 1 January, 2002 to 1 September, 2012 (n=699). The relationship between pulmonary vascular resistance and all-cause 30-day mortality was evaluated using univariate and multivariate analyses. Results The 30-day mortality included 10 patients (1.43%), which is lower than in the previous analyses. Receiver operating curve analysis of pulmonary vascular resistance index as a predictor of mortality yielded a cut-off value of 3.37 Wood Units×m2, but the area under the curve and specificity of this threshold was weaker than in previous analyses. Whereas pulmonary vascular resistance index treated as a dichotomised variable was a significant predictor of mortality in univariate (odds ratio 4.92, 95% confidence interval 1.04-23.33, p=0.045) and multivariate (odds ratio 5.26, 95% confidence interval 1.07-25.80, p=0.041) analyses, pulmonary vascular resistance index treated as a continuous variable was not a significant predictor of mortality in univariate (p=0.12) or multivariate (p=0.11) analyses. Conclusions The relationship between pulmonary vascular resistance and post-heart transplant mortality in children is less convincing in this analysis of a comprehensive, contemporary database than in previous series. This suggests the possibility that modern improvements in the management of post-transplant right ventricular dysfunction have mitigated the contribution of pulmonary hypertension to early mortality.
Radiation effects in low dielectric constant methyl-silsesquioxane films

The use of state-of-the-art microelectronic devices in space radiation environments faces new challenges with the adoption of low dielectric constant (low-k) materials as interlevel dielectrics. This is demonstrated in a preliminary study of methyl-silsesquioxane low-k films. We report radiation damage, induced by a 2 keV low-current-density (/spl sim/2/spl times/10/sup 6/ s/sup -1/ cm/sup -2/) positron beam, and observed by positron annihilation spectroscopy.
Preflight Radiometric Calibration of the Orbiting Carbon Observatory

This paper describes the radiometric calibration of the original Orbiting Carbon Observatory. The calibration process required characterizing both the dark current level and gain coefficients of each instrumental channel. The dark response was characterized with extensive testing and revealed some unexpected instrument behavior. The gain coefficients were characterized via illumination of the instrument spectrometers with a laboratory calibrated integrating sphere source. Comparison between the spectrometer output and a calibrated photodiode led to a set of calibration coefficients for each spectrometer channel. The calibration coefficients were validated by a novel approach involving observation of the solar spectrum through a transmission filter. Validation occurred by examination of both the ratio of the filtered to unfiltered spectra and retrievals of geophysical quantities such as surface pressure. The linearity of the calibration was established to approximately 0.2%. Finally, using the calibration data from the integrating sphere, a simple noise model was developed for each channel of the instrument. A summary of the signal to-noise performance is included.
Evaluation of DLC1 as a prostate cancer susceptibility gene: mutation screen and association study

Abstract A gene or genes on chromosome 8p22-23 have been implicated in prostate carcinogenesis by the observation of frequent deletions of this region in prostate cancer cells. More recently, two genetic linkage studies in hereditary prostate cancer (HPC) families suggest that germline variation in a gene in this region may influence prostate cancer susceptibility as well. DLC1 (deleted in liver cancer), a gene in this interval, has been proposed as a candidate tumor suppressor gene because of its homology (86% similarity) with rat p122 RhoGAP, which catalyzes the conversion of active GTP-bound rho complex to the inactive GDP-bound form, and thus suppresses Ras-mediated oncogenic transformation. A missense mutation and three intronic insertions/deletions in 126 primary colorectal tumors have been previously identified. However, there are no reports of DLC1 mutation screening in prostate tumors or in germ line DNA of prostate cancer patients. In this study, we report the results of the first mutation screen and association study of DLC1 in genomic DNA samples from hereditary and sporadic prostate cancer patients. The PCR products in the 5′ UTR, all 14 exons, exon–intron junctions, and 3′ UTR were directly sequenced in 159 HPC probands. Eight exonic nucleotide polymorphisms (SNPs) were identified, only one of which resulted in an amino acid change. Twenty-three other SNPs were identified in intronic regions. Seven informative SNPs that spanned the complete DLC1 gene were genotyped in an additional 249 sporadic cases and 222 unaffected controls. No significant difference in the allele and genotype frequencies were observed among HPC probands, sporadic cases, and unaffected controls. These results suggest that DLC1 is unlikely to play an important role in prostate cancer susceptibility.