cssi/SciSciGPT-SciSciNet huggingface dataset:
Underfill constraint effects during thermomechanical cycling of flip-chip solder joints

The presence of an “underfill” encapsulant between a microelectronic device and the underlying substrate is known to substantially improve the thermal fatigue life of flip-chip (FC) solder joints, primarily due to load-transfer from the solder to the encapsulant. In this study, a new single joint-shear (SJS) test, which allows the measurement of the strain response of an individual solder ball during thermomechanical cycling (TMC), has been used to investigate the impact of the constraint imposed by the underfill on a solder joint. Finite element (FE) modeling has been used to demonstrate that the SJS sample geometry captures most of the deformation characteristics of an FC joint and to provide insight into experimental observations. It has been shown that the strain response of a eutectic Pb-Sn solder joint is influenced significantly by in-situ microstructural coarsening during TMC, which in turn is dependent on the underfill properties. In general, underfill properties, which allow the imposition of large compressive-hydrostatic stresses on the solder joint, were the most effective in reducing coarsening. Phase coarsening prevented the stabilization of the stress-strain response of the solder, even in the absence of crack damage, and was found to depend strongly on the local inelastic-strain state within the joint. This necessitates that future solder deformation models account for strain-history-dependent microstructural evolution and that underfill properties be optimized to minimize the extent of coarsening during TMC in order to maximize joint life.
Practical approaches to ISO 9000 certification for rubber and plastics processors

The background of the ISO 9000 series of quality standards is discussed, including where and why they originated. Registration statistics are provided for manufacturers in the United States and Ohio. Realistic benefits of certification are introduced, citing examples from reported case studies in the recent literature. The specifics of the ISO 9000 series are outlined, including the levels of certification and the key elements of ISO 9001, the most stringent standard. Fundamental requirements for management commitment, training, employee involvement, and implementation time and costs are also discussed. A listing is provided that cross-references registrars with standard industrial classification and typical services. >
A randomized, double-blind, placebo-controlled pilot study of sublingual versus oral immunotherapy for the treatment of peanut allergy

Background Although promising results have emerged regarding oral immunotherapy (OIT) and sublingual immunotherapy (SLIT) for the treatment of peanut allergy (PA), direct comparisons of these approaches are limited. Objective This study was conducted to compare the safety, efficacy, and mechanistic correlates of peanut OIT and SLIT. Methods In this double-blind study children with PA were randomized to receive active SLIT/placebo OIT or active OIT/placebo SLIT. Doses were escalated to 3.7 mg/d (SLIT) or 2000 mg/d (OIT), and subjects were rechallenged after 6 and 12 months of maintenance. After unblinding, therapy was modified per protocol to offer an additional 6 months of therapy. Subjects who passed challenges at 12 or 18 months were taken off treatment for 4 weeks and rechallenged. Results Twenty-one subjects aged 7 to 13 years were randomized. Five discontinued therapy during the blinded phase. Of the remaining 16, all had a greater than 10-fold increase in challenge threshold after 12 months. The increased threshold was significantly greater in the active OIT group (141- vs 22-fold, P = .01). Significant within-group changes in skin test results and peanut-specific IgE and IgG 4 levels were found, with overall greater effects with OIT. Adverse reactions were generally mild but more common with OIT ( P Conclusion OIT appeared far more effective than SLIT for the treatment of PA but was also associated with significantly more adverse reactions and early study withdrawal. Sustained unresponsiveness after 4 weeks of avoidance was seen in only a small minority of subjects.
A Generalization of Tyuriemskih's Lethargy Theorem and Some Applications

Tyuriemskih's Lethargy Theorem is generalized to provide a useful tool for establishing when a sequence of (not necessarily) linear operators that converges point wise to the identity operator actually converges arbitrarily slowly. Then this generalization is used to answer affirmatively a 2010 conjecture of ours as well as establishing that all of the classical operators of Bernstein, Hermite-Fejer, Landau, Fejer, and Jackson converge arbitrarily slowly to the identity operator (and not just almost arbitrarily slowly as we established in 2010).
Prepared responses and gastric lesions in rats

The importance of prepared responses (Seligman & Hager, 1972) in the induction of stomach lesions by tailshock restraint in rats was examined in two experiments. In Experiment 1, the prevention of a species-specific defense reaction by bodily restraint led to increased levels of stomach ulceration compared with controls. In Experiment 2, giving highly restrained rats the opportunity to engage in gnawing, a prepared response for the rat, resulted in a significant reduction in gastric pathology. The data were related to Weiss’ two-factor model of coping behavior and ulceration.
Measurements of optical turbulence with higher-order structure functions

Higher-order structure functions have been used to extract atmospheric optical Cn2 profiles from a vertical sequence of temperature data collected by a single probe carried by a meteorological balloon. This technique circumvents trends and fluctuations in the atmospheric mean temperature and simplifies the equipment and complexity of measurement collection compared with traditional, horizontal differential-probe pair systems.
Design of Dislocation-Compensated ZnS y Se 1− y /GaAs (001) Heterostructures

The understanding of lattice relaxation and dislocation dynamics in lattice-mismatched semiconductors makes it possible to design metamorphic device structures utilizing the dislocation compensation mechanism for reduced defects, improved performance, and enhanced reliability. We have developed a dislocation dynamics model accounting for misfit–threading interactions and have applied it to ZnSySe1−y/GaAs (001) heterostructures.1 Dislocation compensation involves the removal of threading dislocations associated with one sense of misfit dislocations by bending them over to create misfit dislocations of the opposite sense at an intentionally mismatched interface. Here we investigated the design of dislocation-compensated ZnSySe1−y/GaAs (001) heterostructures and considered the sulfur mole fraction tolerances applicable to such structures. We considered two types of structures: type A involved a uniform-composition (ungraded) layer on top of a uniform-composition buffer, while type B involved a uniform-composition layer on a linearly graded buffer. For each structure type we studied the requirements on the thickness and compositional profile of the buffer layer to optimize the removal of mobile threading dislocations from the top uniform (device) layer as well as the allowed tolerance in compositional overshoot to achieve structures with low threading dislocation density. We show for both types of structure that (i) for given compositional overshoot at the buffer–device layer interface, there is an optimum buffer thickness which minimizes the dislocation density; and (ii) for given buffer thickness there is an optimum overshoot which minimizes the dislocation density.
Hepatitis delta antigen requires a flexible quasi-double-stranded RNA structure to bind and condense hepatitis delta virus RNA in a ribonucleoprotein complex.

UNLABELLED The circular genome and antigenome RNAs of hepatitis delta virus (HDV) form characteristic unbranched, quasi-double-stranded RNA secondary structures in which short double-stranded helical segments are interspersed with internal loops and bulges. The ribonucleoprotein complexes (RNPs) formed by these RNAs with the virus-encoded protein hepatitis delta antigen (HDAg) perform essential roles in the viral life cycle, including viral replication and virion formation. Little is understood about the formation and structure of these complexes and how they function in these key processes. Here, the specific RNA features required for HDAg binding and the topology of the complexes formed were investigated. Selective 2'OH acylation analyzed by primer extension (SHAPE) applied to free and HDAg-bound HDV RNAs indicated that the characteristic secondary structure of the RNA is preserved when bound to HDAg. Notably, the analysis indicated that predicted unpaired positions in the RNA remained dynamic in the RNP. Analysis of the in vitro binding activity of RNAs in which internal loops and bulges were mutated and of synthetically designed RNAs demonstrated that the distinctive secondary structure, not the primary RNA sequence, is the major determinant of HDAg RNA binding specificity. Atomic force microscopy analysis of RNPs formed in vitro revealed complexes in which the HDV RNA is substantially condensed by bending or wrapping. Our results support a model in which the internal loops and bulges in HDV RNA contribute flexibility to the quasi-double-stranded structure that allows RNA bending and condensing by HDAg. IMPORTANCE RNA-protein complexes (RNPs) formed by the hepatitis delta virus RNAs and protein, HDAg, perform critical roles in virus replication. Neither the structures of these RNPs nor the RNA features required to form them have been characterized. HDV RNA is unusual in that it forms an unbranched quasi-double-stranded structure in which short base-paired segments are interspersed with internal loops and bulges. We analyzed the role of the HDV RNA sequence and secondary structure in the formation of a minimal RNP and visualized the structure of this RNP using atomic force microscopy. Our results indicate that HDAg does not recognize the primary sequence of the RNA; rather, the principle contribution of unpaired bases in HDV RNA to HDAg binding is to allow flexibility in the unbranched quasi-double-stranded RNA structure. Visualization of RNPs by atomic force microscopy indicated that the RNA is significantly bent or condensed in the complex.
Working memory components as predictors of children's mathematical word problem solving.

Abstract This study determined the working memory (WM) components (executive, phonological loop, and visual–spatial sketchpad) that best predicted mathematical word problem-solving accuracy of elementary school children in Grades 2, 3, and 4 ( N = 310). A battery of tests was administered to assess problem-solving accuracy, problem-solving processes, WM, reading, and math calculation. Structural equation modeling analyses indicated that (a) all three WM components significantly predicted problem-solving accuracy, (b) reading skills and calculation proficiency mediated the predictive effects of the central executive system and the phonological loop on solution accuracy, and (c) academic mediators failed to moderate the relationship between the visual–spatial sketchpad and solution accuracy. The results support the notion that all components of WM play a major role in predicting problem-solving accuracy, but basic skills acquired in specific academic domains (reading and math) can compensate for some of the influence of WM on children’s mathematical word problem solving.
Stochastically Resilient Observer Design for a Class of Continuous-Time Nonlinear Systems

Abstract This work addresses the design of stochastically resilient or non-fragile continuous-time Luenberger observers for systems with incrementally conic nonlinearities. Such designs maintain the convergence and/or performance when the observer gain is erroneously implemented due possibly to computational errors i.e. round off errors in computing the observer gain or changes in the observer parameters during operation. The error in the observer gain is modeled as a random process and a common linear matrix inequality formulation is presented to address the stochastically resilient observer design problem for a variety of performance criteria. Numerical examples are given to illustrate the theoretical results.
The high-mosaicity illusion: revealing the true physical characteristics of macromolecular crystals.

In the paper by Bellamy et al. [(2000), Acta Cryst. D56, 986–995] d was incorrectly listed in equations (1) and (5). The correct term is d* defined as d* = λ/d (where d is the resolution; d = λ/2sinθhkl). The correct equations are as follows|\varphi _R| = (L^2 \zeta ^2 \gamma _h ^2 + \gamma _v ^2) ^{1/2} + d^*{L}\cos \theta _{hkl}\left [{\eta + \left({{{\delta \lambda }\over \lambda }}\right)\tan \theta _{hkl}}\right] . \eqno (1)\eta = {{| {\varphi _R }| - ({L^2 \zeta ^2 \gamma _h ^2 + \gamma _v ^2)^{1/2} }}\over {{Ld^*}\cos \theta _{hkl}}}- \left({{{\delta \lambda }\over \lambda }}\right)\tan \theta _{hkl}. \eqno (5)The correct equations were used in the BEAM-ish software (Lovelace et al., 2000) and the data in Bellamy et al. (2000) and subsequent manuscripts were not affected. This is the second erratum to Bellamy et al. (2000), the first being Bellamy et al. (2001).
Observation of anomalous transmission modes in nickel at microwave frequencies

Abstract A study has been made of the transmission of energy through nickel crystals in magnetic fields up to 13 kG using incident microwave power at 9.37 GHz. The transmission spectrum has been studied as a function of temperature and magnetic field orientation relative to the sample surface. A new set of anomalous transmission modes has been observed with the field perpendicular to the sample plane; these modes cannot be explained within the framework of existing theoretical models describing the resonance excitation of sound in ferromagnetic metals by electromagnetic waves.
A BIVARIATE-REGRESSION MODEL FOR ESTIMATING CHEMICAL COMPOSITION OF STREAMFLOW OR GROUNDWATER / Modèle de régression bivarié pour l'évaluation de la composition chimique de l'écoulement total ou des eaux souterraines

Abstract Regressions between concentrations of major inorganic constituents and either specific conductance or streamflow discharge characterize chemical-quality conditions at a sampling site or of an area and can be used to estimate streamflow chemical-quality composition over time and in space where information is lacking or deficient. In this manner, less costly water quality network operations may be achieved for a given programme, enabling available resources to be reallocated to the collection and analysis of data where information is deficient. The SYSLAB system is a sequential set of documented special-purpose computer programs for statistically and graphically analysing historical water-quality records and deriving relevant regression relationships based upon this analysis. These computer programs have been applied under a variety of hydrological conditions to characterize regional chemical-quality patterns across the United States and in Pakistan. Case-study results using the proposed methodolog...
NATIONALISM AS IDEOLOGY, NATIONALISM AS EMOTION, AND THE PITFALLS OF NATIONAL DEVELOPMENT

Modernization and economic development of nation-states in the past century or so owe a great deal to the development of nationalism as ideology. However, the institutions and legislation that have evolved out of this ideology appear to have outlived their usefulness in today’s interdependent world. What the framers of the theory of modern nation-states failed to anticipate is the degree to which national development is influenced by nationalism as emotion as opposed to nationalism as ideology. This paper analyzes the way national development is shaped by the interplay between nationalism as ideology and nationalism as emotion in the context of global interdependence.
Mechanical Description of the Mars Climate Sounder Instrument

This paper introduces the Mars Climate Sounder (MCS) Instrument of the Mars Reconnaissance Orbiter (MRO) spacecraft. The instrument scans the Martian atmosphere almost continuously to systematically acquire weather and climate observations over time. Its primary components are an optical bench that houses dual telescopes with a total of nine channels for visible and infrared sensing, and a two axis gimbal that provides pointing capabilities. Both rotating joints consist of an integrated actuator with a hybrid planetary/harmonic transmission and a twist cap section that enables the electrical wiring to pass through the rotating joint. Micro stepping is used to reduce spacecraft disturbance torques to acceptable levels while driving the stepper motors. To ensure survivability over its four year life span, suitable mechanical components, lubrication, and an active temperature control system were incorporated. Some life test results and lessons learned are provided to serve as design guidelines for actuator parts and flex cables.
A model for low frequency excess noise in Si-JFETs at low bias

Abstract Spectral analyses of the fluctuating drain-source voltages in n - and p -channel Si-JFETs at low bias conditions revealed generation-recombination (G-R) noise over a temperature range of 150–300 K in both types of devices. The corner frequencies f C and the low frequency plateau values of the Lorentzian spectra were used to study the nature of the noise. In the n -channel device, f C was strongly temperature dependent; an activation energy, E C − E T , of approximately 0.36 eV was obtained from the Arrhenius plot. For the p -channel device, a much higher corner frequency of 20–30 kHz was measured. Based on the experimental results we are led to consider a model for low frequency noise in JFETs that accounts for fluctuations in the channel thickness, and the correlated fluctuations in the number and the mobility of carriers. The relative significance of the three noise mechanisms was found to depend strongly on temperature, doping concentrations, device dimensions, and the energy level of the recombination centers.
Morphological variability in second-stage juveniles and males of Meloidogyne chitwoodi

The morphology of Meloidogyne chitwoodi is relatively poorly characterised. In a recent study, morphological variation in adult females of M. chitwoodi was analysed. However, comparable data are lacking for adult males and second-stage juveniles (J2). Therefore, our studies of four M. chitwoodi isolates from the western USA, representing all currently known races and pathotypes, were designed to characterise intraspecific morphological variability in J2 and males and to compare it to variability found in adult females. Multivariate analysis of variance indicated statistically significant variation among isolates for both J2 and males. Moreover, for adult males, canonical discriminant analysis grouped races with their respective pathotypes. In addition, we analysed two morphological features that were previously uncharacterised for M. chitwoodi, i.e., stylet knob width and distance from secretory-excretory pore to anterior end. Both of these characters may be useful in distinguishing M. chitwoodi from closely related species. SEM clearly showed the presence of areolations along the bodies of J2, thereby separating M. chitwoodi from M. fallax and M. minor. In summary, this study indicates that M. chitwoodi J2 and adult males show substantially more intraspecific morphological variability than previously known. Consequences for diagnostics are discussed.
Intraoperative Application of Power Doppler Imaging: Visualization of Myocardial Perfusion After Anastomosis of Left Internal Thoracic Artery to Left Anterior Descending Coronary Artery

Abstract The purpose of this study was to determine the role of power Doppler imaging in assessing patency of coronary artery bypass graft (CABG) anastomosis. Twelve consecutive patients referred for CABG with the use of anastomosis of the internal thoracic artery to the left anterior descending coronary artery (LAD) were studied. A linear 6.5-MHz wide-band transducer was used during cardioplegic administration and reperfusion. Baseline power Doppler signals were obtained in the LAD in 11 patients, and post-CABG signals were obtained in 11 patients. In one patient the LAD was poorly visualized because of extensive calcification. In another patient the flow after bypass worsened and the graft was revised. Visualization of the LAD and internal thoracic artery grafts by epicardial intraoperative power Doppler imaging is feasible in almost all patients and allows rapid and simple intraoperative assessment of graft patency. In addition, myocardial perfusion is limited by heavily calcified coronaries. (J Am Soc Echocardiogr 1999;12:650-4.)
The participation of macrophages and monocytes in experimental immune complex glomerulonephritis.

Abstract Serial renal biopsies were performed in rabbits with acute and with chronic serum sickness to determine the timing and extent of macrophage accumulation in the development of glomerular injury. The presence of macrophages in glomeruli was assessed by the techniques of glomerular cell culture, histochemical staining for nonspecific esterase activity, and electron microscopy. In acute serum sickness large numbers of macrophages (mean 98/glomerulus) were detected in glomeruli at the time of immune elimination when proteinuria developed and maximum glomerular hypercellularity was observed. Seven days after immune elimination the accumulation of macrophages was greatly diminished (mean 8/glomerulus) and paralleled the resolution of proteinuria and glomerular hypercellularity. In the animals with chronic serum sickness a spectrum of glomerular histological lesions was seen. This varied from minor degrees of endocapillary proliferation and mesangial expansion to diffuse proliferation with crescent formation. The disease course was related to the capacity of individual animals to mount an antibody response which determined the daily antigen dose and consequently the levels of circulating immune complexes. Macrophage accumulation in glomerular injury also varied between animals (1–130/glomerulus) and correlated with the timing and degree of proteinuria and glomerular hypercellularity.
RELIABLE EVALUATION OF DYSPNEA (RED-ROSE): A PROSPECTIVE ANCILLARY STUDY FROM THE RENAL OPTIMIZATION STRATEGIES EVALUATION IN ACUTE HEART FAILURE (ROSE-AHF) TRIAL

Dyspnea relief is a regulatory benchmark in acute heart failure (AHF) and typically assessed by a dyspnea visual analog scale (DVAS). We hypothesized that a provocative dyspnea score (PDS) assessing dyspnea under incrementally more difficult conditions is a more sensitive metric of change (Δ) in
Evaluation of reactive sputtering of ZnS in Ar-O 2 environment as a pathway to Zn(O, S) thin-films

Zn(O, S) has previously been demonstrated to be a viable replacement for the traditional CdS buffer layer in CIGS based thin-film photovoltaic devices. The deposition methods for Zn-based buffer layers include wet chemical bath deposition, PVD, ALD, and other techniques. This work focuses on the evaluation of Zn(O, S) layers on glass by sputtering. Results with RF reactive magnetron sputtering of a ZnS target in Ar-O2 environment are demonstrated. Deposition rate decreases steadily with O2 introduction without any sputter hysteresis; this suggests that the process is controllable. XRD confirms the presence of Zn(O, S), the composition of which can be tuned by varying S:O in the film. Initial results show 9.5% cell efficiency for CIGS devices with a Zn(O, S) buffer. QE suggests that the band-gap of Zn(O, S) buffer is higher than that of CdS buffer.
From individuals to epidemics.

Heterogeneous mixing fundam entally changes the dynamics of infectious diseases; finding ways to incorporate it into models represents a critical challenge. Phenomenological approaches are deficient in their lack of attention to underlying processes; individual-based models, on the other hand, may obscure the essential interactions in a sea of detail. The challenge then is to find ways to bridge these levels of description, starting from individual-based models and deriving macroscopic descriptions from them that retain essential detail, and filter out the rest. In this paper, attempts to achieve this transformation are described for a class of models where nonrandom mixing arises from the spatial localization of interactions. In general, the epidemic threshold is found to be larger owing to spatial localization than for a homogeneously mixing population. An improved estimate of the dynamics is developed by the use of moment equations, and a simple estimate of the threshold in terms of a ‘dyad heuristic’. For more general models in which local infection is not described by mass action, the connection with related partial differential equations is investigated.
Risks and uncertainties in virtual worlds: an educators’ perspective

Virtual worlds present tremendous advantages to cyberlearning. For example, in virtual worlds users can socialize with others, build objects and share them, customize parts of the world and hold lectures, do experiments, or share data. However, virtual worlds pose a wide range of security, privacy, and safety concerns. This may lead educators to become (or not) apprehensive of the virtual worlds in using and adapting them as learning technologies. This study examined how educators perceive risks and uncertainties in virtual worlds. We also investigated how educators’ level of use of virtual worlds influences their risk perception level. Our results indicate a divergence between risk perception and reality in the virtual worlds. We use the seminal risk perception model developed by Fischhoff and his colleagues, and our revision to this model to explain these results. Finally, we discuss implications of our research for education management, and make recommendations to educators and policy makers who consider using virtual worlds as a learning technology.
Inhaled human insulin treatment in patients with type 2 diabetes mellitus.

Pulmonary delivery of insulin in patients with type 2 diabetes who require insulin improved glycemic control, was well tolerated, and demonstrated no adverse pulmonary effects.
An improved Voigt line approximation for the calculations of equivalent width and transmission.

Abstract An improved approximation for the Voigt profile is proposed to calculate the equivalent width and the transmission functions for three different random models in terms of closed formulas. The accuracy of the calculations is significantly improved, while the computation required is comparable in magnitude to the previous approximation suggested by Fels.
Redundant segments inZea mays detected by translocations of monoploid origin

Twenty-two independently occurring spontaneous reciprocal translocations were isolated from monoploid X diploid crosses in maize and their breakpoints were determined. As 12 of the translocations involved the same two chromosomes and had breakpoints at approximately the same positions (6L. 2–3, 7L. 2–3) and two other translocations appeared to be identical with breakpoints at 2L. 9, 6L. 4, 14 of the 22 translocations probably arose by crossing over within duplicate segments of nonhomologous chromosomes. Thus, at least part of the bivalents seen at diakinesis and chromatid bridges seen at anaphase I in monoploid plants appear to be generated by recombination between redundant chromosome segments. The other eight translocations each occurred once. Because our evidence indicates that recombination between nonhomologous illegitimately synapsed chromosome segments does not occur in maize, these were probably also produced by recombination between redundant segments. If one assumes that their breakpoints also mark regions of interchromosomal redundancy, other conclusions can be reached: A) corn does not contain detectable homoeologous chromosomes, thus it is precently a true diploid, and B) as exchanges giving rise to translocations did not occur in the centromeres or proximal heterochromatin, these regions either do not possess redundancy or are rarely involved in chiasma formation. Furthermore, the duplicated segments in the genome giving rise to translocations in haploid microsporocytes probably have the same serial order with respect to the centromere.
QCD analysis of the scale-invariance of jets

Studying the substructure of jets has become a powerful tool for event discrimination and for studying QCD. Typically, jet substructure studies rely on Monte Carlo simulation for vetting their usefulness; however, when possible, it is also important to compute observables with analytic methods. Here, we present a global next-to-leading-log resummation of the angular correlation function which measures the contribution to the mass of a jet from constituents that are within an angle $R$ with respect to one another. For a scale-invariant jet, the angular correlation function should scale as a power of $R$. Deviations from this behavior can be traced to the breaking of scale invariance in QCD. To do the resummation, we use soft-collinear effective theory relying on the recent proof of factorization of jet observables at ${e}^{+}{e}^{\ensuremath{-}}$ colliders. Nontrivial requirements of factorization of the angular correlation function are discussed. The calculation is compared to the Monte Carlo parton shower and next-to-leading order results. The different calculations are important in distinct phase space regions and exhibit that jets in QCD are, to very good approximation, scale invariant over a wide dynamical range.
SLURP-1 and -2 in normal, immortalized and malignant oral keratinocytes

The secreted mammalian Ly-6/urokinase plasminogen activator receptor-related proteins (SLURP)-1 and -2 are produced by keratinocytes comprising the mucocutaneous epithelium. They regulate in autocrine and paracrine ways cell growth and differentiation through the nicotinic acetylcholine receptors (nAChRs) expressed on the plasma membrane. Keratinocyte nAChRs are targeted by tobacco-derived carcinogenic nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) that can induce tumorigenic transformation of Het-1A keratinocytes. In this study we asked if SLURPs could abolish tumorigenic effects of nitrosamines. Preincubation with either recombinant SLURP-1 or -2 in both cases considerably reduced the number of colonies in soft agar, and the number of tumor nodules >0.5 cm in diameter in Nu/Nu mice produced by Het-1A cells treated with nitrosamines. The levels of SLURP-1 and -2 mRNA transcripts in nitrosamine-transformed Het-1A cells as well as in the tumor cell lines SCC-25 and FaDu were significantly (p<0.05) less compared to normal gingival keratinocytes, which are probably the major source of the secreted SLURPs found in a sample of human saliva. The expression of SLURPs was decreased due to gene silencing of different nAChR alpha subunits with small hairpin RNA, suggesting that a positive feedback regulation is altered in malignant cells. Thus, SLURP-1 and -2 are efficient autocrine and paracrine ligands of keratinocyte nAChRs capable of preventing tobacco nitrosamine-induced malignant transformation of oral cells. These "proof-of-concept" preliminary results have salient clinical implications.
Growth of RuO2 by electrochemical and gas-phase oxidation of an Ru(0001) surface

Abstract Rectangular monolayer stripes of RuO 2 (1 1 0) obtained in a simple gas-phase oxidation of an Ru(0 0 0 1) surface in argon (Ar) containing 115 ppm of O 2 were compared with the electrochemical oxidation of an Ru(0 0 0 1) surface in sulfuric acid at high positive potentials. In situ scanning tunneling microscopy (STM) showed that the electrochemical oxidation of the Ru(0 0 0 1) surface starts at step edges, and proceeds through the formation of randomly distributed RuO 2 islands. The nucleation process is instantaneous, as verified by potential step experiments. The oxidation of Ru(0 0 0 1) in a mixture of O 2 (115 ppm) and Ar produces a layer of ordered RuO 2 (1 1 0) oxide in the form of rectangular stripes of monolayer height. The growth of these stripes, globally initiated at the step’s edges, is unidirectional, forming a 60° angle to the steps’ direction. The entirely different morphologies of RuO 2 grown in electrochemical- and gas-phase oxidation environments probably reflect the difference in the reaction temperature of two processes. In the latter, the elevated temperatures (600–800 K) appear to confer mobility on the reaction species that facilitates ordering of the oxide layer.
A bilinear T(b) theorem for singular integral operators

Abstract In this work, we present a bilinear Tb theorem for singular integral operators of Calderon–Zygmund type. We prove some new accretive type Littlewood–Paley results and construct a bilinear paraproduct for a para-accretive function setting. As an application of our bilinear Tb theorem, we prove product Lebesgue space bounds for bilinear Riesz transforms defined on Lipschitz curves.
Calculation of Si nanowire thermal conductivity using complete phonon dispersion relations

The lattice thermal conductivity of crystalline Si nanowires is calculated. The calculation uses complete phonon dispersions, and does not require any externally imposed frequency cutoffs. No adjustment to nanowire thermal conductivity measurements is required. Good agreement with experimental results for nanowires wider than 35 nm is obtained. A formulation in terms of the transmission function is given. Also, the use of a simpler, nondispersive ``Callaway formula,'' is discussed from the complete dispersions perspective.
Withering heights: did indentured servants shrink from an encounter with Malthus? A comment on Komlos

R ecently in this journal, Komlos estimated the height of English and Irish indentured servants and transported convicts born between 1710 and 1760 using evidence taken from advertisements for runaway servants placed in North American newspapers.2 He found 'that the nutritional status of Englishmen began to decline with the birth cohorts of the 1730s. . . . According to the regression estimates, the decline [in height] between the 1720s and the 1740s was between 0.5 and 0.6 inches.'3 He pointed out that this 'was synchronous with the acceleration in the English population expansion in the 1730s'.4 He concluded, 'even if we acknowledge these limitations of the evidence, it appears that the height of the lower segments of the English population was probably beginning to decline prior to the beginning of the industrial revolution, and contemporaneously with the acceleration in population growth. In other words, population growth had started once again to press on available food supplies.'5 Komlos's claim is important because it provides a pre-nineteenthcentury example in which anthropometric measures diverge from conventional economic measures of the standard of living, indicating a deterioration in well-being during the first half of the eighteenth century when
Damage characterization using reverberant decays

A new, quantitative, non-destructive evaluation technique is described for estimating both the severity and spatial extent of damage in engineering materials. The technique exploits the unique decay character of non-proportionally damped systems. Theoretical expressions relating decay and damage characteristics are presented and compared with physical experiments on an analogous system. Initial experimental results support the proposed technique.
β-Adrenergic receptors and their interacting proteins

The three subtypes of β-adrenergic receptor (βAR) all interact with G proteins as a central aspect of their signaling. The various βAR subtypes also associate differentially with a variety of other cytoplasmic and transmembrane proteins. These βAR-interacting proteins play distinct roles in the regulation of receptor signaling and trafficking. The specificity of βAR associations with various binding partners can help to explain key physiological differences between βAR subtypes. Moreover, the differential tissue expression patterns of many of the βAR-interacting proteins may contribute to tissue-specific regulation of βAR function.
A microcomputer-based deep-level transient spectroscopy (DLTS) system

A totally automated, microcomputer-based deep-level transient spectroscopy (DLTS) system developed at the University of Arkansas is described. The hardware and interfaces are discussed in terms of their accuracy and contribution to the requirements for performing DLTS measurements. The software developed to control the hardware, as well as that used to acquire, reduce, and manipulate the data, is explained. The software introduces the concept of building a database by sampling the transient decay at equal intervals over a temperature scan of equal temperature increments. This method allows for cycling the hardware and test device only once through a temperature scan and storing the data for later analysis.
Thermal techniques in biomembrane and lipoprotein research

Abstract In structural determinations of inanimate materials, thermal analysis has long proven to be a powerful technique, particularly when coupled with X-ray diffraction or spectroscopic methods. In molecular biology, thermal analysis, frequently combined with other techniques, similarly shows itself to be a powerful tool. Its importance is not limited solely to understanding biological structures but extends to understanding physiological processes as well. This paper describes the application to molecular biology of differential scanning calorimetry (DSC) and the complementary technique of differential scanning dilatometry (DSD). The modification and operation of two commercial differential scanning calorimeters for use in molecular biology is discussed, as well as the design and operation of a novel differential scanning dilatometer together with its auxiliary techniques. Some examples are given of the uses of these methods in understanding the structure, thermodynamic state, and physiological functions of biological membranes. A further illustration of the type of approach taken in applying thermal analysis to molecular biology is provided by a description of an ongoing study. This study uses DSC and DSD in correlation with the temperature dependence of ultraviolet circular dichroism (CD) to elucidate the structures of human high density (HDL) and low density (LDL) serum lipoproteins.
Epinephrine-chlortetracycline induced arrhythmia in the isolated rat heart.

SummaryThe effect of chlortetracycline-HC1 on the isolated rat heart is practically identical with the effect of a known chelating agent, tetrasodium versenate. This effect can be reversed temporarily by Mn++. Thus, chlortetracycline seems to cause irregularities in the isolated rat heart by chelation of the co-factor of cholinesterase which inactivates this enzyme and permits acetylcholine to accumulate and to exert its inhibitory effect on the heart. The co-factor of cardiac cholines-terase may be Mn++.
Formation of U(V) in a molten fluoride salt at 550–650°C by reaction of gaseous UF6 with dissolved UF4

Abstract The reaction of gaseous UF 6 with UF 4 dissolved in molten LiFBeF 2 ThF 4 (72-16-12 mole%) was studied over the temperature range 550–650°C. Chemical and spectrophotometric evidence showed that U(V) was formed in the salt according to the reaction UF 6( g ) + UF 4( d ) = 2UF 5( d ) , in which ( g ) and ( d ) denote gas and dissolved species, respectively. The studies were conducted using gold apparatus, since gold was the only material found to be inert to both gaseous UF 6 and dissolved UF 5 . When UF 5 was present in low concentrations, it disproportionated slowly according to the reverse of the above reaction; the rate was second-order with respect to the UF 5 concentration. The results indicated that, when UF 5 was present in high concentrations, its vaporization from the salt and subsequent disproportionation in the vapor phase were significant. Under all conditions studied, however, the pressure of uranium-containing species in the vapor phase was less than 0·004 atm.
Biofiltration control of hydrogen sulfide. 2. Kinetics, biofilter performance, and maintenance.

The kinetics of H2S oxidation in a biofilter were evaluated and the reaction rates determined to be first-order at low concentrations ( 400 ppm), and fractional-order in the intermediate concentration range for H2S in the inlet waste gas. The overall performance of the biofilter system and changes in compost properties were investigated for 200 days of operation. The compost biofilter showed good buffering capacities to variations in gas flow rate and pollutant (H2S) loading impacts. Hydrogen sulfide removal efficiencies exceeding 99.9% were consistently observed. System acidification and sulfate accumulation were identified as inhibitors of required biological activity. Routine washing of the compost effectively mitigated these deficiencies. System upset was determined to be caused by compost dry-out or system overloading. Methods were developed to provide for recovery of contaminated filter material.
Environmental Sex Determination: Interaction of Temperature and Genotype in a Fish

Sex determination in an atherinid fish, the Atlantic silverside (Menidia menidia), is under the control of both genotype and temperature during a specific period of larval development. The sex ratios of the progeny of different females are variable and differ in their responsiveness to temperature. This demonstrates that sex ratio in fishes that normally have separate sexes can be influenced by the environment.
The chemistry and catalysis of the toluene hydrodealkylation reaction: I. The specific activities and selectivities of Group VIIB and Group VIII metals supported on alumina

Abstract The catalytic hydrodealkylation of alkylaromatics is a reaction of continued industrial interest. In this and the following paper, investigations of the chemistry and catalysis of the hydrodealkylation reaction over supported metals are reported. The first paper will discuss the specific activities and selectivities of alumina-supported Group VIIB and Group VIII metals for the model reaction of toluene and hydrogen to produce benzene and methane. The relative specific activities (rates per surface metal atom) of the metals for benzene formation at 380 °C are: Ni, 1000; Rh, 329; Ir, 177; Os, 69; Ru, 47; Pt, 9; Pd, 2; Re, 1. The selectivities (molecules benzene formed per toluene molecule reacted) of these metals are: Pd, 1.0; Rh, 0.98; Pt, 0.96; Ir, 0.95; Ni, 0.94; Os, 0.93; Re, 0.85; Ru, 0.82. The dependence of rate on the partial pressures of hydrogen and toluene over these metals are reported for the first time. For hydrogen the dependence of rate on partial pressure varies from −0.39 for Pd to 1.65 for Re. The dependence of rate on toluene partial pressure varies from −0.17 for Re to 0.47 for Pt and Pd. The magnitudes and periodic trends of these kinetic parameters are found to be substantially different from the periodic trends of these metals previously observed for other CC bond breaking reactions such as ethane hydrogenolysis. Where possible the results of this present study are compared to those of other workers. For example, the specific activities of Rh and Pd reported here are in good agreement with results previously reported, but differ substantially for the specific activities of Ru and Pt. In agreement with this study, the previous studies point to rhodium as the most active noble metal for the toluene hydrodealkylation reaction.
An evaluation of Rb-Sr dating of pseudotachylyte: Structural-chemical models and the role of fluids

Rb-Sr geochronometry has been used in several studies in an effort to date pseudotachylyte and therefore the fault hosting the pseudotachylyte and the tectonism that produced the faulting. The usual procedure has been the “thin-slab” technique, which in metamorphic rocks involves construction of an isochron using whole rock analyses of adjacent but compositionally different slices of rock, and is based on the assumption of isotopic equilibrium between the slices. In attempts to date pseudotachylyte, analyses have been obtained using a pseudotachylyte vein and the immediately adjacent host rock. Such studies commonly yield: 1) apparent ages with high errors owing to small a small range of Rb/Sr values or to “scatterchron” data; 2) host rocks not plotting on the same isochron or scatterchron defined by the pseudotachylyte; 3) apparent dates that are inconsistent with other estimates of the time of faulting; or 4) apparent ages that are not independently constrained. These studies commonly fail to record the type of pseudotachylyte vein utilized; injection veins are commonly larger and more obvious targets for collecting but are likely to yield geologically meaningless dates. A Rb-Sr geochronometric study of pseudotachylyte from the North Cascade Mountains, Washington, reveals: 1) an apparent age older than the likely age of the pseudotachylyte; 2) pseudotachylyte and host rock chemical and isotopic characteristics indicating that the pseudotachylyte was not the result of bulk melting of normal schist; and 3) metasomatism prior to pseudotachylyte formation likely affected both the protolith and what is now the host rock. In light of previous studies, the new data, and related information regarding fault-related metasomatism, three closed system models and one open system model for pseudotachylyte formation are proposed. These models make specific predictions regarding apparent whole rock-pseudotachylyte dates, microstructural features, and the relationship between the whole-rock pseudotachylyte date and the whole rock-biotite Rb-Sr dates in the same rock. The models suggests pseudotachylyte-host rock dating is unlikely to produce real ages of pseudotachylyte formation. Worse, because many pseudotachylytes apparently form during cooling and uplift, the technique will instead yield a seemingly reasonable but geologically meaningless date. Certain approaches to the problem, including a microstructural analysis coupled with a whole rock-biotite age on the same rock, may yield an actual age of pseudotachylyte formation, but the assumptions made heretofore about the behavior of the Rb-Sr system at the time of pseudotachylyte formation are questionable.
Optimal quality adaptation for MPEG-4 fine-grained scalable video

Dynamic behavior of the Internet's transmission resources makes it difficult to provide perceptually good quality of streaming video. MPEG-4 Fine-Grained Scalable coding is proposed to deal with this problem by distributing the data in enhancement layers over a wide range of bit rates. However, encoded video also exhibits significant data rate variability to provide a consistent quality video. We are, therefore, faced with the problem of trying to accommodate the mismatch between the available bandwidth variability and the encoded video variability. In this paper, we investigate quality adaptation of the layered VBR video generated by MPEG-4 FGS. Our goal is to develop a quality adaptation scheme that maximizes perceptual video quality through minimizing quality variation while at the same time increasing the usage of available bandwidth. We develop an optimal adaptation scheme and an online heuristic based on whether the network conditions are known a priori. Experimental results show that the online heuristic as well as the optimal adaptation algorithm provide consistent video quality when used over both TFRC and TCP.