cssi/SciSciGPT-SciSciNet huggingface dataset:
Recombinant human parainfluenza virus type 2 with mutations in V that permit cellular interferon signaling are not attenuated in non-human primates

The HPIV2 V protein inhibits type I interferon (IFN) induction and signaling. To manipulate the V protein, whose coding sequence overlaps that of the polymerase-associated phosphoprotein (P), without altering the P protein, we generated an HPIV2 virus in which P and V are expressed from separate genes (rHPIV2-P+V). rHPIV2-P+V replicated like HPIV2-WT in vitro and in non-human primates. HPIV2-P+V was modified by introducing two separate mutations into the V protein to create rHPIV2-L101E/L102E and rHPIV2-Delta122-127. In contrast to HPIV2-WT, both mutant viruses were unable to degrade STAT2, leaving virus-infected cells susceptible to IFN. Neither mutant, nor HPIV2-WT, induced significant amounts of IFN-beta in infected cells. Surprisingly, neither rHPIV2-L101E/L102E nor rHPIV2-Delta122-127 was attenuated in two species of non-human primates. This indicates that loss of HPIV2's ability to inhibit IFN signaling is insufficient to attenuate virus replication in vivo as long as IFN induction is still inhibited.
Learning disabled children's problem solving: Identifying mental processes underlying intelligent performance

Abstract Learning disabled and nondisabled children's “thinking aloud” protocols were analyzed from a picture arrangement task. Protocols were analyzed at three levels: (a) global mental processing and task performance, (b) groupings of subroutines that function as heuristic processes, and (c) groupings of subroutines that function as strategies. Although learning disabled and nondisabled children were comparable in global mental processing and task performance, learning disabled children had difficulty in the heuristic subroutine of problem representation and deleting irrelevant information. In addition, nondisabled children were superior to learning disabled children in using strategy subroutines that relate to evaluation, systematic problem solving, feedback, and pattern extraction. A stepwise regression analysis suggested that learning disabled children's overall mental processing was best predicted by a heuristic, whereas nondisabled children's overall mental processing was best predicted by specific strategy subroutines. Theoretical and educational implications of the results were discussed.
Using Touch-Screen Technology, Apps, and Blogs To Engage and Sustain High School Students' Interest in Chemistry Topics

As part of an outreach program, we integrated chemistry apps with blogging to enhance the learning experience of students in and outside the classroom. Our outreach program involved college mentors who participated in the development and implementation of chemistry lessons alongside the classroom teacher. Three technology-rich modules that focused on molecules, balancing equations, and nuclear chemistry were taught to high school students. Feedback-oriented and interactive lessons through apps with blogging were used to engage the students with the instructors as well as their peers. The combination of blogging with interactive apps increased student involvement and sustained their interests in the chemistry topics covered by the modules. The students were divided into experimental and control groups. The experimental groups were required to use the blog, where students viewed the questions and uploaded their answers and comments. The control group did not have access to the blog during the modules. Perfo...
Validity of sampling error as a cause of noncorrelation

BACKGROUND. Sampling error is a common explanation of noncorrelation in women whose Papanicolaou (Pap) tests show high-grade intraepithelial lesions (HSIL) but whose follow-up cervical biopsies show only cervical intraepithelial neoplasia (CIN) 1, koilocytosis, or reactive/inflammatory changes. The purpose of this study was to demonstrate the validity of sampling error in this setting by determining the proportion of negative colposcopic cervical biopsies in women with HSIL who subsequently undergo cone/loop electrode excision procedure (LEEP) biopsies or repeat cervical biopsies that confirm the diagnosis of high-grade CIN (HGCIN). METHODS. In all, 368 cases of HSIL were retrieved from the computerized database from January 1, 2003 to December 31, 2005. Follow-up was obtained as part of routine quality assurance/quality control activities including cytologic-histologic correlation. RESULTS. A total of 368 HSIL Pap diagnoses were retrieved. Of the 254 cases that were followed up by cervical biopsy, 146 showed HGCIN in the biopsy. Of the remaining 108 patients whose cervical biopsies failed to demonstrate HGCIN, 47 had a subsequent procedure, either cone/LEEP, cervical biopsy, or repeat Pap test. Cone biopsy/LEEP was performed in 34 cases (72.3%) with a diagnosis of HGCIN in 19. Repeat cervical biopsy was performed in 9 cases (19.1%) with HGCIN diagnosed in 5. Repeat Pap test was performed in 4 cases (8.5%) with HSIL diagnosed in 2. CONCLUSIONS. In the population of women with HSIL by Pap test followed up by cervical biopsy with or without subsequent cone/LEEP, there was a discordant cervical biopsy rate for HGCIN of 43%. In the subgroup of women with HSIL by Pap test followed up by cervical biopsy and subsequent cone/LEEP or repeat cervical biopsy, the proportion of women with negative colposcopic cervical biopsy and subsequent histology-proven HGCIN was 56%. These figures justify sampling error as a valid cause of noncorrelation in women with HSIL followed up by cervical biopsy alone. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.
latin american peasant studies in a “postcolonial” era

This paper outlines a series of connected, but discontinuous traditions in the Study of Latin American peasantries and argues for the continuing importance of peasant studies for an understanding of Latin American fields of power
Signals and pathways controlling regulatory T cells

Summary Induction of specific immune tolerance to grafts remains the sought-after standard following transplantation. Defined by expression of the Foxp3 (forkhead box protein 3) transcription factor, the regulatory T-cell (Treg) lineage has been noted to exert potent immunoregulatory functions that contribute to specific graft tolerance. In this review, we discuss the known signals and pathways which govern Treg development, both in the thymus and in peripheral sites, as well as lineage maintenance and homeostasis. In particular, we highlight the roles of T-cell receptor signaling, CD28 costimulation, and signals through phosphatidyl inositol 3-kinase (PI3K) and related metabolic pathways in multiple aspects of Treg biology.
Interhemispheric and Intrahemispheric Control of Emotion: A Focus on Unilateral Brain Damage.

Neocortical contributions to emotional processing are discussed. First, parameters critical to the neuropsychological study of emotion are examined: interhemispheric (right, left) and intrahemispheric (anterior, posterior) factors, processing mode (expression, perception), and communication channel (facial, prosodic, lexical). Second, neuropsychological theories of emotion are described: right-hemisphere and valence hypotheses. Third, experimental studies of right-brain-damaged, left-brain-damaged, and normal adults are reviewed, on the basis of mode and channel, with a focus on stroke. Findings support right cerebral hemispheric dominance for emotion, regardless of valence and channel, and are more consistent for perception than expression. When lesion site is a factor, posterior sites are important for perception and anterior ones for expression. Finally, clinical implications are suggested for aphasia rehabilitation and for assessment of affect in neurological disorders.
Importance of timing of gestational exposure to methotrexate for its teratogenic effects when used in setting of misdiagnosis of ectopic pregnancy.

Objective To report a case of embryopathy due to misadministration of methotrexate in the setting of suspected ectopic pregnancy that resulted in a different pattern of malformations than is typically seen with methotrexate. Design Case report. Setting Community hospital. Patient(s) A 30-year-old primigravida women exposed to methotrexate (50 mg/m 2 ) at 5 6/7 weeks' gestation. Intervention(s) The patient underwent amniocentesis because of abnormal results at the first-trimester genetic screening (low levels of pregnancy associated plasma protein A and hCG) and fetal echocardiogram because of single umbilical artery. Main Outcome Measure(s) Fetal anomalies. Result(s) The fetus was found to have a single umbilical artery, tetralogy of Fallot, and a "horseshoe lung," despite administration of high doses of folic acid. The pregnancy ultimately ended with fetal demise at 30 weeks. Conclusion(s) As medical management of ectopic pregnancy becomes more common, practitioners should be cautious about the potential teratogenic effects in unrecognized intrauterine pregnancies and be able to diagnose the myriad defects, including cardiac anomalies, that could result from such exposure.
The formation of hurricane Humberto (2001): The importance of extra-tropical precursors

The authors examine the formation of hurricane Humberto (2001) in the Atlantic basin. Precursor disturbances originating in the extratropics appear critical for inducing tropical cyclogenesis. One precursor near the tropopause arose during the development of hurricane Erin on 7 September and could be tracked continuously for 12 days until 1200 UTC 19 September. A fully explicit numerical simulation with the PSU/NCAR mesoscale model produces a generally realistic evolution of the developing storm during a 4-day period beginning 0000 UTC 19 September. Diagnostics of the simulations reveal that moderate vertical shear was crucial for organizing convection, and this shear was enhanced on the periphery of an upper-level vortex, within a lower- to mid-tropospheric baroclinic zone. Downdraughts and evaporative cooling produced a rearward propagating bore that organized new convection in a notably moistened environment with small CAPE. Vorticity generation maximized near 1 km above mean sea level and the vortex built upward with time. This evolution contrasts markedly with ‘downward development’ conceptual models of tropical cyclogenesis and points to the crucial need for observations in the lower troposphere before depression formation. Convective-scale dynamics were governed by intense convective cores which produced most of the diabatic heating and lower-tropospheric vertical vorticity. They were constrained by vertical shear to populate the downshear-left quadrant of the vortex, and therefore their collective behaviour was organized despite being quasi-random within the favoured region. Ultimately, the shear that helped organize the convection in the developing depression hampered Humberto's subsequent intensification. Copyright © 2006 Royal Meteorological Society
Acceptability of tobacco cessation interventions in the pediatric emergency department.

Objectives:To assess the acceptability to parents and staff of providing a brief tobacco cessation intervention incorporating the first 2 A's of the Clinical Practice Guideline on Treating Tobacco Use and Dependence (Ask and Advise) + fax referral to a state tobacco quitline from the emergency depar
Theory of Paraelectric Resonance and Relaxation

The theory of paraelectric resonance (PER) and relaxation is reformulated to allow a consistent treatment of dynamic lattice processes, even in the case when coupling to the lattice is strong. A simple model Hamiltonian is used and certain response functions are calculated without using perturbation theory. It is shown that the main effect of the strong lattice coupling at low temperatures is to induce a renormalization of the tunneling parameter of the paraelectric dipoles. The structure of phonon sidebands in PER is discussed. The theory predicts a strong transfer of intensity from the PER lines to the sidebands above a certain characteristic temperature. A treatment is given of paraelectric relaxation using the same techniques. A calculation of the temperature dependence of dipole-lattice relaxation time agrees well with experiment with adjustment of two parameters.
Comparison of theoretical and simulation-based predictions of grain-boundary Kapitza conductance in silicon

We present a comparison between molecular-dynamics (MD) simulation and theoretical calculations using input from wave-packet simulations of the Kapitza conductance of two different grain boundaries in silicon. We find that for a $\ensuremath{\Sigma}3(111)$ twin boundary with minimal disruption of the lattice, the Kapitza conductance is extremely high in contrast to previous results obtained for the $\ensuremath{\Sigma}29(001)$ grain boundary. Theoretical predictions based on input from wave-packet simulations appear to show reasonable agreement with MD results for the $\ensuremath{\Sigma}29(001)$ grain boundary but disagreement by a factor of about ten for the $\ensuremath{\Sigma}3(111)$ boundary. The origin of the apparent discrepancies is analogous to previously noted difficulties in comparing theoretical predictions to experimental measurements of the Kapitza conductance. We show why the apparent discrepancies are large when the interface phonon transmission is high and relatively small when the phonon transmission is low. We demonstrate how the theoretical predictions and MD simulation results can be compared in a consistent and meaningful way, thereby removing the apparent contradictions. These questions also are discussed in the important context of relating MD results to experimental observations.
Theory of FM laser oscillation

The paper presents a detailed analysis of FM laser oscillation which includes the effect of arbitrary atomic lineshape, saturation, and mode pulling. Such oscillation is achieved by means of an intracavity phase perturbation, and is a parametric oscillation wherein the laser modes oscillate with FM phases and nearly Bessel function amplitudes. One principal idea is that of the competition between different FM oscillations. The effect of the intracavity phase perturbation is to associate a set of sidebands with each of the previously free-running laser modes. While the free-running laser modes experienced their gain from essentially independent atomic populations, the competing FM oscillations to a large extent see the same atomic population; and in cases of interest the strongest of these oscillations is able to quench the competing weaker oscillations and establish the desired steady state condition. Results of the analysis include the following: threshold and power output, amplitudes and phases of all sidebands, frequency pulling of the entire oscillation, time domain behavior, distortion, super-mode conversion efficiency, and effect of mirror motion. Results of numerical application of the theory to a number of specific cases are given.
Production of superoxide radicals in glyoxysomal membranes from castor bean endosperm

Summary The production of superoxide free radicals (O 2 · - ) by NADH was investigated in glyoxysomal membranes from germinating castor bean ( Ricinus communis L., cv. Hale) endosperm purified by treatment with 0.1 M Na 2 CO 3 About 25 % of the NADH : cytochrome c reductase activity in glyoxysomal membranes was mediated by 0O 2 · - radicals induced by NADH. The rate of superoxide production by glyoxysomal membranes from castor bean endosperm (about 27 nmol O 2 · - x mg -1 protein x min -1 ) was the highest measured so far in peroxisomal membranes. Incubation of membranes with an antibody against whole glyoxysomal membrane proteins from castor bean endosperm produced an inhibition of about 40 % in the NADH-dependent O 2 · - -generation, whereas the O 2 · - -independent NADH : cytochrome c reductase activity was not affected. A superoxide dismutase isoenzyme was detected by native gel electrophoresis and characterized as a Mn-superoxide dismutase, and appeared to be a peripheral protein of glyoxysomal membranes. The NADH-induced generation of O 2 · - -radicals by glyoxysomal membranes from castor bean endosperm supports the idea that the production of superoxide is a common metabolic property of peroxisomal membranes. The possible function of Mn-superoxide dismutase in glyoxysomal membranes is discussed.
An implicit scheme for calculating time- and frequency-dependent flux limited radiation diffusion in one dimension

Abstract A flexible and accurate method for solving nonlinear time- and frequency-dependent flux-limited radiation diffusion and radiation-matter coupling problems in one dimension is developed. The method is based on converting the set of partial differential equations for the flux-limited multigroup diffusion approximation into a system of ordinary differential equations which are integrated by a generalized stiff equation solver. Unlike previous operator-splitting techniques which can introduce instabilities into the solution or which produce smooth but highly inaccurate solutions, this scheme provides a reliable accurate solution with reduced overall computational effort. The solutions describe both the streaming and diffusion limits of transport theory and are stable with time steps comparable to the changes in physical variables.
Affinity chromatography of pancreatic carboxypeptidases using a carboxypeptidase inhibitor from potatoes as ligand

Abstract A two-step purification scheme based on affinity chromatography has been developed for bovine and porcine carboxypeptidases A and B. Enzyme preparations of high purity are achieved from extracts of pancreatic acetone powder in less than 1 day by this procedure. The application of trypsin-treated extracts of pancreatic acetone powder to immobilized carboxypeptidase inhibitor from potatoes results in the specific retention of the target exopeptidases. After clution of the bound carboxypeptidases A and B at high pH, the resultant mixture of the two enzymes is resolved by chromatography on a column of ϵ-amino-n-caproyl- d -arginine-Sepharose 4B. Overall yields of 70–80% of the purified enzymes have been obtained with no cross-contamination of detectable tryptic or chymotryptic activities of the preparations.
Experimental and theoretical studies of the interaction of gas phase nitric acid and water with a self-assembled monolayer

Nitric acid in air is formed by atmospheric reactions of oxides of nitrogen and is removed primarily through deposition to surfaces, either as the gas or after conversion to particulate nitrate. Many of the surfaces and particles have organic coatings, but relatively little is known about the interaction of nitric acid with organic films. We report here studies of the interaction of gaseous HNO(3) with a self-assembled monolayer (SAM) formed by reacting 7-octenyltrichlorosilane [H(2)C=CH(CH(2))(6)SiCl(3)] with the surface of a germanium infrared-transmitting attenuated total reflectance (ATR) crystal that was coated with a thin layer of silicon oxide (SiO(x)). The SAM was exposed at 298 ± 2 K to dry HNO(3) in a flow of N(2), followed by HNO(3) in humid N(2) at a controlled relative humidity (RH) between 20-90%. For comparison, similar studies were carried out using a similar crystal without the SAM coating. Changes in the surface were followed using Fourier transform infared spectroscopy (FTIR). In the case of the SAM-coated crystal, molecular HNO(3) and smaller amounts of NO(3)(-) ions were observed on the surface upon exposure to dry HNO(3). Addition of water vapor led to less molecular HNO(3) and more H(3)O(+) and NO(3)(-) complexed to water, but surprisingly, molecular HNO(3) was still evident in the spectra up to 70% RH. This suggests that part of the HNO(3) observed was initially trapped in pockets within the SAM and shielded from water vapor. After increasing the RH to 90% and then exposing the film to a flow of dry N(2), molecular nitric acid was regenerated, as expected from recombination of protons and nitrate ions as water evaporated. The nitric acid ultimately evaporated from the film. On the other hand, exposure of the SAM to HNO(3) and H(2)O simultaneously gave only hydronium and nitrate ions. Molecular dynamics simulations of defective SAMs in the presence of HNO(3) and water predict that nitric acid intercalates in defects as a complex with a single water molecule that is protected by alkyl chains from interacting with additional water molecules. These studies are consistent with the recently proposed hydrophobic nature of HNO(3). Under atmospheric conditions, if HNO(3) is formed in organic layers on surfaces in the boundary layer, e.g. through NO(3) or N(2)O(5) reactions, it may exist to a significant extent in its molecular form rather than fully dissociated to nitrate ions.
Nebela tuberculata comb. nov. (Arcellinida), its History and Ultrastructure

SYNOPSIS. The name Nebela tuberculata comb. nov. is proposed for the testate ameba formerly known as Difflugia tuberculata (Wallich, 1864) Archer, 1867. The generic reassignment is based upon the test construction material which is shown, by electronmicrographs and X-ray diffraction, to be autogenous regular and irregular silicious rods. A brief history of the animal is recounted utilizing works of several authors who have encountered the ameba over the last century.
Spatially Adaptive Regression Splines and Accurate Knot Selection Schemes

Spline procedures have proven effective in estimating smooth functions. However, spline procedures based on stepwise addition and/or deletion have some drawbacks. They suffer from the knot compounding problem, making their performance suboptimal. Furthermore, due to computational complexity, spline procedures may not achieve their full potential. In this article, we propose a novel knot selection algorithm for regression spline estimation in nonparametric regression. The algorithm includes three new components: knot relocation, guided search, and local fitting. The local properties of the spline functions are used to efficiently implement the algorithm. Extensive simulation studies are performed to demonstrate the improvement of the new knot selection algorithm over the stepwise addition and deletion scheme, and the advantages of the spline procedure with the new knot selection scheme over alternative adaptive methods. In the simulations, our procedure achieves very competitive performance with alternativ...
A bacteriophage RNA polymerase transcribes through a Xenopus 5S RNA gene transcription complex without disrupting it

Conditions are described for programming with active transcription complexes essentially all the Xenopus 5S RNA genes added to an extract of Xenopus oocyte nuclei. We call this rate enhancement. Transcription by SP6 RNA polymerase of either strand of a Xenopus 5S RNA gene is unimpeded by the presence of a complete transcription complex associated with the internal control region of the gene. Furthermore, the transcription complex remains stably associated with the 5S RNA gene following multiple transits by the prokaryotic polymerase.
A test of the predictive dimensions model in spatial voting theory

We model correlated voter-candidate issue data within the framework of the Enelow-Hinich spatial model of predictive dimensions. The empirical consequences of this model of the issue data are surprising and allow for an indirect test of the Enelow-Hinich spatial model. The central prediction of the correlated data model we construct, which depends critically on the underlying spatial model, is tested with issue data from the 1980 NES pre-election interview. The test results are highly supportive of the model's predictions. We conclude both that the spatial model of predictive dimensions is empirically supported and that candidate spatial locations estimated by the model are not an artifact of correlated voter-candidate issue data.
Purification of a phospholipase C froM Bacillus cereus

Abstract Phospholipase C activity present in the growth medium of Bacillus cereus was purified 20-fold by chromatography on polyethyleneimine-cellulose columns, or by treatment with protamine sulfate and subsequent chromatography on DEAE-cellulose columns. Purified enzyme preparations retained the ability to hydrolyze ethanolamine phosphoglycerides in the absence of choline phosphoglycerides. A typical preparation had a specific activity of about 9 μmoles/min per mg toward purified diacyl glycerophosphoryl ethanolamine and a specific activity of about 15–20 μmoles/ min per mg toward diacyl glycerophosphorylmonomethylethanolamine and diacyl glycerophosphoryl choline. Monoacyl glycerophosphate was not hydrolyzed under similar conditions.
Indicators of disciplinary differentiation : Interdisciplinary linkages and adoption rate of biological innovations

Two indicators regarded to reflect the status of disciplinary differentiation were assessed through citation analysis. Adoption of scientific innovations (publications utilizing new scientific information) and interdisciplinary linkages (percentage of total publications of single disciplines which are cross-referenced by other disciplines) were investigated in selected biological professions. Findings indicated: 1) a significant delay in the use of innovations and a significant difference in the emphasis of interdisciplinary linkages in several professions and disciplines; 2) faster adoption of innovations and greater interdisciplinary linkages in areas with broader disciplinary contents; 3) an inter-personal communication pattern; and 4) slower adoption in applied than in basic fields.
Cellular systems—I. stability of chemical systems

Abstract In this work, we attempt to formulate and partially resolve the “complexity vs. stability” problem in open chemical systems, in the framework of Lyapunov's second method. Sufficient conditions are given for stability of the steady state of a chemical system under structural perturbations caused by interactions among the chemical species in the system. As a byproduct of this analysis, we will show important properties of the self-inhibitory chemical systems, and establish the tolerance of the stability to a broad class of perturbations. Finally, biological open systems are exhibited in order to show the scope of our stability analysis.
Prognostic Significance of Coronary Calcific Deposits in Asymptomatic High-Risk Subjects

Abstract PURPOSE: To determine the predictive value of coronary calcifications for coronary heart disease events in high-risk, asymptomatic adults. PATIENTS AND METHODS: A prospective cohort study of 1,461 high-risk, asymptomatic subjects were followed for 55 months with a 98% success rate. Coronary risk factor assessment and cardiac fluoroscopy with digital subtraction enhancement were performed to determine the number of calcified coronary arteries. RESULTS: Fifty-eight percent of this cohort (852 subjects) had fluoroscopically detectable coronary calcification: 437 (30%) had calcium in one, 253 (17%) in two, and 162 (11%) in all three coronary vessels. There were 90 (6%) deaths, 35 (39%) attributable to coronary heart disease, and 43 (3%) nonfatal myocardial infarctions. Subjects with calcification in more than one major coronary artery were 2.2 times more likely to suffer coronary death or nonfatal infarction ( P = 0.001) than were subjects with one or no calcified arteries. Multivariable logistic regression analysis showed that only the number of calcified arteries, age, total cholesterol, history of diabetes, and left ventricular hypertrophy by electrocardiogram were associated independently with the incidence of coronary death or infarction in these subjects. CONCLUSIONS: Coronary calcification predicts coronary heart disease death or infarction in high-risk asymptomatic adults as well as do standard risk factors.
Logistic regression trees for initial selection of interesting loci in case-control studies

Modern genetic epidemiology faces the challenge of dealing with hundreds of thousands of genetic markers. The selection of a small initial subset of interesting markers for further investigation can greatly facilitate genetic studies. In this contribution we suggest the use of a logistic regression tree algorithm known as logistic tree with unbiased selection. Using the simulated data provided for Genetic Analysis Workshop 15, we show how this algorithm, with incorporation of multifactor dimensionality reduction method, can reduce an initial large pool of markers to a small set that includes the interesting markers with high probability.
Plutonium oxidation state distributions in the Pacific Ocean during 1980–1981

Abstract The concentration of plutonium and its oxidation state distribution have been measured as a function of depth at three locations in the North Pacific Ocean. Concentration profiles were similar to those observed in the same area during 1974 with primary maxima at depths of a few hundred meters below the surface and secondary maxima near the bottom. Oxidation state distribution profiles were similar at the three locations with plutonium about equally divided between the reduced and oxidized forms except near the bottom. There the oxidized form was more abundant and comprised ∼ 90% of the total plutonium. No major change in oxidation state occurred at the depths of the shallow concentration maxima suggesting that their formation and persistence were not dependent upon a redox change. The concentration maxima near the bottom coincided with the enhanced abundance of the poorly sorbed oxidized form suggesting that they resulted from the loss of oxidized plutonium from the sediments.
A Low-Power BiCMOS 4-Element Phased Array Receiver for 76–84 GHz Radars and Communication Systems

This paper presents a 76-84 GHz low-power 4- element phased array receiver built using a 0.13 μm BiCMOS process. The power consumption is reduced by using a single-ended design and alternating the amplifiers and phase shifter cells to result in a low noise figure at a low power consumption. A variable gain amplifier and an 11° trim bit are used to correct for the rms gain and phase errors at different operating frequencies. The phased array consumes 32 mW per channel and results in a gain of 10-19 dB at 76-84 GHz, a noise figure of 10.5 ±0.5 dB at 80 GHz and an rms gain and phase error <;0.8 dB and <;7.2 °, respectively, up to 81 GHz, and <;1.1 dB and 10.4° up to 84 GHz. The phased array also shows a channel to channel coupling of <; - 30 dB up to 84 GHz. To our knowledge, this work presents state-of-the-art on-chip performance at W-band frequencies.
Confocal Microscopy Analysis of Supercritical Fluid Impregnation of Polypropylene

The impregnation of a fluorescent probe [4-(hexadecylamino)-7-nitrobenz-2-oxa-1,3-diazole or NBD] into polypropylene from supercritical carbon dioxide is presented. Confocal microscopy was combined with traditional thermodynamic and spectroscopic studies to demonstrate distinct differences between supercritical fluid impregnation, solution coating, and solvent casting. The results show improved partitioning and distribution of the solute from supercritical solutions relative to conventional techniques.
P450cin Active Site Water: Implications for Substrate Binding and Solvent Accessibility

In P450cin Tyr81, Asp241, Asn242, two water molecules, and the substrate participate in a complex H-bonded network. The role of this H-bonded network in substrate binding and catalysis has been probed by crystallography, spectroscopy, kinetics, isothermal titration calorimetry (ITC), and molecular dynamics. In the Y81F mutant the substrate binds about 20-fold more weakly than WT while Vmax decreases by about 30%. Enhanced susceptibility of the heme to H2O2 destruction in Y81F suggests that this mutant favors the open, low-spin conformational state. Asn242 H-bonds directly with the substrate and replacing the former with Ala results in water taking the place of the missing Asn side chain. This mutant exhibits a 70% decrease in activity. Crystal structures and molecular dynamics simulations of substrate bound complexes show that solvent has more ready access to the active site, especially in the N242A mutant. This accounts for about 64% uncoupling of electron transfer from substrate hydroxylation. These data indicate the importance of the interconnected water network on substrate binding and the on the open/close conformational equilibrium both of which are critically important for maintaining high coupling efficiency.
Laplacian Eigenmaps for dimensionality reduction and data representation

One of the central problems in machine learning and pattern recognition is to develop appropriate representations for complex data. We consider the problem of constructing a representation for data lying on a low-dimensional manifold embedded in a high-dimensional space. Drawing on the correspondence between the graph Laplacian, the Laplace Beltrami operator on the manifold, and the connections to the heat equation, we propose a geometrically motivated algorithm for representing the high-dimensional data. The algorithm provides a computationally efficient approach to nonlinear dimensionality reduction that has locality-preserving properties and a natural connection to clustering. Some potential applications and illustrative examples are discussed.
Constraints on the mantle temperature gradient along the Southeast Indian Ridge from crustal structure and isostasy: implications for the transition from an axial high to an axial valley

SUMMARY Axial and ridge flank depths on the Southeast Indian Ridge (SEIR) systematically increase for 2500 km from 90 ◦ E to 120 ◦ E approaching the Australian-Antarctic Discordance. The SEIR also experiences an abrupt change in ridge axis morphology near 103 ◦ 30 � E with axial highs found to the west and axial valleys to the east. Since the spreading rate is constant throughout this region, these variations have been ascribed to an along-axis gradient in mantle temperature. A seismic refraction experiment provides information on the crustal thickness and seismic velocity structure of two segments with differing axial morphology. Segment P2, centred near 102 ◦ E with an axial high has a mean crustal thickness of 5.9 ± 0.2 km, while the mean crustal thickness is 5.3 ± 0.3 km at Segment S1 with an axial valley and centred near 109 ◦ 45 � E. Isostatic compensation of the difference in crustal thickness and density structure between the two segments only accounts for 33 m of the 198 m difference in average ridge flank depth between the two segments. The remaining depth difference must result from a difference in mantle density. Melt production models imply a mantle temperature difference of 11–13.5 ◦ C to produce the observed difference in crustal thickness. Isostatic compensation of the two segments requires that the resulting density difference must extend to about 300 km in the mantle. The transition in axial morphology along the SEIR is very abrupt occurring over a narrow zone within a single segment in which the transition is complete. If a linear mantle temperature gradient is assumed, the temperature difference across the transition segment is only 2.4 ◦ C. The change in axial morphology is accompanied by abrupt changes in other parameters including abyssal hill height, magnetic anomaly amplitude, layer 2a thickness and the presence or absence of an axial magma lens. The abrupt, coincident change in a number of parameters with a very small change in mantle temperature strongly suggests a threshold change between two distinctly different modes of crustal accretion. The trigger for the transition appears to be whether a steady-state crustal magma lens can be maintained.
Discrimination of retrograde from anterograde atrial activation using intracardiac electrogram waveform analysis.

cardiac Eiectrogram Waveform Analysis. The prevention 0/pacemaker-mediated tachycardias requires a safe, reliabie method for distinguishing retrograde from anterograde atrial activation by dual chamber pacemakers. Jn this study, a technique was developed to detect the morphoIogicaJ change that occurs in the waveform of the intra-afrial eiecfrogram during retrograde atriaJ activation. The method employed for waveform analysis is based upon statisticai correiation. In 19 patients undergoing eJectrophysioiogicaJ studies, atrial electrograms were recorded from bipolar endocardial electrodes during sinus rhythm and 1:1 retrograde atrial depolarization while undergoing right ventricular pacing. Data were digitally sampled at 750, 1,000, and 1,500 Hz. Templates of anterograde atrial depolarization were constructed by signai averaging waveforms from an initial sinus rhythm passage. These were used for analysis of anterograde depolarizations from a subsequent passage of sinus rhythm and a passage of known retrograde atrial depolarization. Jn all 19 cases, a patient-specijic threshold could be derived to separate anterograde from retrograde atrial depolarizations using 1,000 Hz and 1,500 Hz sampling rates. However, at a sampling rate of 750 Hz, separation o/an(erograde/rom retrograde atriaJ activation was possible in only 16/19 patients {84%}. We conclude that correlation waveform analysis of a suitably sampled atrial eJectrogram is a reliable method of discriminating retrograde atrial depolarization from anterograde atrial depolarization in intracardiac electrograms. (PACE, VoJ. 12, Octoher 1989}
Development of an implantable networked neuroprosthesis

Neuroprosthetic devices are powerful tools providing functional enhancement for individuals with central nervous system disorders, such as spinal cord injury and stroke. Life sustaining and enhancing independent functions such as breathing, standing, walking, grasping, reaching, micturition, and defecation have all been clinically demonstrated using neuroprostheses. Existing implanted neuroprosthetic systems utilize considerable external powering and signal processing, and each system must be customized to the specific application for which it is intended, severely limiting progress in the field and delaying the introduction of new technology to the end user. The networked neuroprosthetic system (NNPS) is based on a network of small implanted modules, distributed throughout the body, and linked to a centralized power source. The modules are connected through a network cable that distributes power to each module from a central rechargeable lithium-ion battery. Each module contains processing capabilities, communicates with other modules via the network cable, and is reprogrammable over the network using a central wireless transcutaneous link. The NNPS is extremely flexible and can be scaled to meet the technical needs of a broad range of neuroprosthetic applications through the selection of the appropriate modules providing the means for broader clinical application of neuroprostheses
Dominant Mutants of the Saccharomyces cerevisiae ASF1 Histone Chaperone Bypass the Need for CAF-1 in Transcriptional Silencing by Altering Histone and Sir Protein Recruitment

Transcriptional silencing involves the formation of specialized repressive chromatin structures. Previous studies have shown that the histone H3–H4 chaperone known as chromatin assembly factor 1 (CAF-1) contributes to transcriptional silencing in yeast, although the molecular basis for this was unknown. In this work we have identified mutations in the nonconserved C terminus of antisilencing function 1 (Asf1) that result in enhanced silencing of HMR and telomere-proximal reporters, overcoming the requirement for CAF-1 in transcriptional silencing. We show that CAF-1 mutants have a drastic reduction in DNA-bound histone H3 levels, resulting in reduced recruitment of Sir2 and Sir4 to the silent loci. C-terminal mutants of another histone H3–H4 chaperone Asf1 restore the H3 levels and Sir protein recruitment to the silent loci in CAF-1 mutants, probably as a consequence of the weakened interaction between these Asf1 mutants and histone H3. As such, these studies have identified the nature of the molecular defect in the silent chromatin structure that results from inactivation of the histone chaperone CAF-1.
Localized velocity anomalies in the lower mantle

Summary. Two localized regions of velocity heterogeneity in the lower mantle with scale lengths of 1000–2000 km and 2 per cent velocity contrasts are detected and isolated through comparison of S, ScS, P and PcP travel times and amplitudes from deep earthquakes in Peru, Bolivia, Argentina and the Sea of Okhotsk. Comparison of the relative patterns of ScS-S differential travel times and S travel-time residuals across North American WWSSN and CSN stations for the different source regions provides baselines for interpreting which phases have anomalous times. A region of low S and P velocities is located beneath Northern Brazil and Venezuela at depths of 1700–2700 km. This region produces S-wave delays of up to 4 s for signals from deep Argentine events recorded at eastern North American stations. The localized nature of the anomaly is indicated by the narrow bounds in azimuth (15°) and take-off angle (13°) of the arrivals affected by it. The long period S-waves encountering this anomaly generally show 30–100 per cent amplitude enhancement, while the short-period amplitudes show no obvious effect. The second anomaly is a high-velocity region beneath the Caribbean originally detected by Jordan and Lynn, who used travel times from deep Peruvian events. The data from Argentine and Bolivian events presented here constrain the location of the anomaly quite well, and indicate a possible short- and long-period S-wave amplitude diminution associated with it. When the travel-time data are corrected for the estimated effects of these two anomalies, a systematic regional variation in ScS-S station residuals is apparent between stations east of and west of the Rocky Mountains. One possible explanation of this is a long wavelength lateral variation in the shear velocity structure of the lower mantle at depths greater than 2000 km beneath North America.
Unified Approach for Uncertainty Analysis Using the AASHTO Mechanistic-Empirical Pavement Design Guide

This paper addresses the problem of uncertainty management for the Mechanistic-Empirical Pavement Design Guide (MEPDG). Specifically, development of an all-inclusive approach to uncertainty management in which model uncertainty and input parameter variability are taken into consideration is presented in this paper. A Gaussian process surrogate model is chosen in this paper as a potential model for the MEPDG design software, and model verification metrics are included to assess the ability of the surrogate model to predict MEPDG output. The construction of a surrogate model that emulates the MEPDG will reduce the computational expense for uncertainty analysis but will introduce another source of uncertainty. Uncertainty propagation of these major sources of uncertainty is performed for a case study. The relative effects of these three major sources of uncertainty are investigated, and the influences of these sources of uncertainty are discussed utilizing the results from the uncertainty propagation. Reliability analysis incorporates the proposed methodology to investigate the effect of these sources of uncertainty for a typical flexible pavement design. DOI: 10.1061/(ASCE)TE.1943-5436.0000355. © 2012 American Society of Civil Engineers. CE Database subject headings: Flexible pavements; Reliability; Uncertainty principles; Model verification; Pavement management; Design. Author keywords: Flexible pavements; Reliability; Uncertainty principles; Model verification; Pavement management.
Engineering Synechococcus elongatus PCC 7942 for Continuous Growth under Diurnal Conditions

Synechococcus elongatus strain PCC 7942 strictly depends upon the generation of photosynthetically derived energy for growth and is incapable of biomass increase in the absence of light energy. Obligate phototrophs' core metabolism is very similar to that of heterotrophic counterparts exhibiting diverse trophic behavior. Most characterized cyanobacterial species are obligate photoautotrophs under examined conditions. Here we determine that sugar transporter systems are the necessary genetic factors in order for a model cyanobacterium, Synechococcus elongatus PCC 7942, to grow continuously under diurnal (light/dark) conditions using saccharides such as glucose, xylose, and sucrose. While the universal causes of obligate photoautotrophy may be diverse, installing sugar transporters provides new insight into the mode of obligate photoautotrophy for cyanobacteria. Moreover, cyanobacterial chemical production has gained increased attention. However, this obligate phototroph is incapable of product formation in the absence of light. Thus, converting an obligate photoautotroph to a heterotroph is desirable for more efficient, economical, and controllable production systems.
Kinematics, U-Pb geochronology, and 40Ar/39Ar thermochronology of the Gold Hill shear zone, North Carolina: The Cherokee orogeny in Carolinia, Southern Appalachians

The Gold Hill shear zone is the most prominent pre-Carboniferous structure in the Southern Appalachian peri-Gondwanan tract of Carolinia. Common perception, based on indirect evidence, holds that it is an Acadian, dextral strike-slip shear zone. However, our recent structural and geochronologic studies directed at the shear zone indicate that it is a complex structure in both time and space. Structural studies in central North Carolina kinematically link deformation in the shear zone to regional shortening structures in both the hanging wall and footwall and indicate that there was a sinistral component to the deformation. Collectively, these structures constitute a regional sinistral transpressional system. We obtained nine new U-Pb zircon ages (Ediacaran–Devonian) and 12 new 40 Ar/ 39 Ar muscovite ages (Late Ordovician–Middle Mississippian); these data, in conjunction with the regional geology indicate that the shear zone has ∼12 km of stratigraphic throw and that the main motion on the zone was Late Ordovician. Collectively, geologic relations, structures, and the distribution of 40 Ar/ 39 Ar ages indicate that the shear zone was reactivated in the Late Devonian and the Middle Mississippian. The regional Late Ordovician–Silurian sinistral transpressive system, of which the Gold Hill shear zone is part, represents the most widespread tectonism documented in Carolinia; it overlaps in time with the Ordovician–Silurian Cherokee unconformity in Laurentian strata and Late Ordovician–Silurian suprasubduction-zone magmatism and metamorphism in peri-Laurentian rocks and consequently is considered a manifestation of the Southern Appalachian Cherokee orogeny, marking the accretion of Carolinia to Laurentia.
Economists, Crises and Cartoons

Economists have occasionally noticed the appearance of economists in cartoons produced for public amusement during crises. Yet the message behind such images has been less than fully appreciated. This paper provides evidence of such inattention in the context of the eighteenth century speculation known as the Mississippi Bubble. A cartoon in The Great Mirror of Folly imagines John Law in a cart that flies through the air drawn by a pair of beasts, reportedly chickens. The cart is not drawn by chickens, however, but by a Biblical beast whose forefather spoke to Eve about the consequences of eating from the tree of the knowledge. The religious image signifies the danger associated with knowledge. The paper thus demonstrates how images of the Mississippi Bubble focused on the hierarchy of knowledge induced by non-transparency. Many of the images show madness caused by alchemy, the hidden or "occult."
Concentration dependence in three-component systems in sedimentation equilibrium in buoyant density gradients

The data on the band widths and band shapes of several DNA's at various concentrations in sedimentation equilibrium in a CsCl density gradient have recently become available. In the present report, these literature data are treated in the following manner: (1) based on a theory of isotope-substitution, calculations are made of the molecular weights at infinite dilution, and (2) to explain the concentration dependence of band widths and band shapes, a theory of charge and hydration is put forth, and it is shown that by retaining the terms involving the charge of the macromolecules, it is possible to account for most of the concentration dependence.