cssi/SciSciGPT-SciSciNet huggingface dataset:
Can nano-photonic silicon circuits become an INTRA-chip interconnect technology?

Surprisingly, nano-photonic silicon has already emerged as a commercial INTER-chip optical communications technology. This was made possible by Silicon-on-Insulator (SOI), technology, which integrates many of the optical communications components directly in silicon CMOS chips. Intel and Luxtera have both announced > 10Gb/sec optical modulators, integrated into Silicon. All the other customarily required opto-electronic components; detectors, waveguides, splitters, couplers, filters, etc., are fully executed in CMOS designs, as well. Continuous wave optical power is provided from off-chip, just as dc power is currently provided from off-chip. The initial commercial applications are optical 10Gb/s Ethernet, Infiniband, and other INTER-chip, communications applications. The question to be addressed in this talk, is whether silicon nano-photonics can now make the final jump, to INTRA-chip optical interconnects?
Organometallic vapor phase epitaxial growth of (Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P and its heterostructures

Low pressure organometallic vapor-phase epitaxial growth of Ga/sub 0.5/In/sub 0.5/P and (Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P is examined. Epitaxial layers of bulk materials are characterized using photoluminescence, electroreflectance, Raman scattering spectroscopy, and surface morphology studies to determine lattice match and optimum growth conditions. Lattice matching at the growth temperature produces featureless growth surfaces, while lattice matching at room temperatures results in minimum photoluminescence linewidth but cracked surfaces due to tensile strain during growth. Raman scattering spectra of the quaternary reveal a three mode structure, with spectral peaks due to GaP-like, InP-like, and AIP-like LO phonons. Heterostructures are investigated including quantum shifts from a series of superlattices. These materials are incorporated in double-heterostructure lasers and single-quantum-well laser with graded-index separate confinement heterostructure. >
The synthesis of dichlorobis(2,2′-bipyridyl)ruthenium(II)

Abstract A new synthesis of cis -[Ru(bipy) 2 Cl 2 ] is presented starting from [Ru(bipy)py 4 ] 2+ . Also, a method for obtaining cis-trans mixtures of [Ru(bipy) 2 Cl 2 ] is described. During conversion of trans [Ru(bipy) 2 py 2 ] 2+ to [Ru(bipy) 2 Cl 2 ] isomerization is found to occur.
Formation of photochromic spiropyran polymer brushes via surface-initiated, ring-opening metathesis polymerization: reversible photocontrol of wetting behavior and solvent dependent morphology changes.

In this article, we described a method for the formation of photochromic polymer brushes grafted from oxide surfaces using surface-initiated ring-opening metathesis polymerization of spiropyran-based monomers in the presence of second generation Grubbs catalyst. The growth of the polymer film, as monitored by ellipsometry and atomic force microscopy (AFM), is strongly influenced by the initial concentrations of the catalyst and monomer, as well as reaction time. These densely packed and highly smooth polymer films were successfully used as surfaces with switchable color and wettability using light as the external stimulus. The relatively nonpolar spiropyran can be switched to a polar, zwitterionic merocyanine isomer (with a larger dipole moment) using light of the appropriate wavelength. This process is reversible and can be switched back using visible light. The spiropyran-merocyanine photoinduced isomerization gives a reversible contact angle change up to 15° for smooth Si/SiO2 substrate under sequentia...
Japanese MBAs: Frontrunners in the Multinationalisation of Japanese Business

As Japanese firms become more involved in foreign operations, they need more personnel skilled in international business. Firms try to obtain such skilled personnel mainly by sending their employees to the United States for MBA degrees. Foreign‐trained Japanese businessmen are currently estimated to be more than 10,000 in number.
The influence of acculturation on drug and alcohol use in a sample of adolescents.

This article reports on the associations between acculturation and substance use among 198 ninth-grade Southern California adolescents (mean age = 13.8 years). Substance use measures included 30-day (current) and lifetime use of alcohol and other drugs. Acculturation was measured using the Acculturation, Habits, and Interests Multicultural Scale for Adolescents (AHIMSA) acculturation scale, a multi-dimensional acculturation scale yielding four acculturation strategy scores. Linear regression analyses evaluated the association between acculturation on alcohol and drug use, adjusting for several covariates. Results revealed that the assimilation acculturation strategy was significantly, but negatively associated with current alcohol use, especially among males. The separation acculturation strategy was significantly and positively associated with current alcohol use, especially among females. Marginalization was associated with greater risk for lifetime alcohol and drug use, especially among males, and a greater risk of current drug use among females. The social influence covariates were predictive of both current and lifetime alcohol and drug use. Future studies should incorporate multidimensional acculturation scales in adolescent substance use to understand how different acculturation strategies impact different populations.
Molecular-field approximation for Josephson-coupled superconducting arrays in a magnetic field

A molecular-field approximation is developed for two-dimensional or three-dimensional Josephson- or proximity-coupled superconducting arrays in an applied magnetic field. The molecular-field transition temperature T/sub c/(H) is found to map onto the highest energy of an electron in a tight-binding band in the presence of a magnetic field (a problem treated by Hofstadter). T/sub c/(H) is thus periodic in H with complex substructure, some of which has been observed experimentally.
Sensitive ammonia gas sensors fabricated using biologically assembled copper sulfide

Copper sulfide-based ammonia (NH3) gas sensors were assembled using a genetically modified viral template. Glutamic acid residues on the filament-shaped bioscaffold surface facilitated the synthesis of nanocrystalline Cu1.8S. Each device comprised a network of biological materials decorated with a nonstoichiometric semiconductor. These chemiresistive devices had high sensitivity to NH3 concentrations from 10 to 80 ppm under room-temperature operation. Response times greater than 15 min were observed. These results demonstrate the potential of biotemplated materials for sensitive gas detection at room temperature.
Feedback sensitivity of the rat hypothalamo-pituitary-adrenal axis and its capacity to adjust to exogenous corticosterone

Chronic stress causing elevated morning (AM) corticosterone (B) concentrations of 2-8 micrograms B/dl does not appear to inhibit subsequent activity in the hypothalamic-pituitary-adrenal (HPA) axis, a surprising finding in view of the known depression in AM basal ACTH by only 3 micrograms B/dl in adrenalectomized rats. To distinguish between the possibilities that either intact rats are less sensitive to B feedback than adrenalectomized rats, or that chronic stress facilitates responses in the HPA axis, we elevated basal B levels in young male rats with slow-release B pellets in the absence of stress. Between 4-6 days after implantation of B pellets at three doses that elevated basal AM (diurnal trough) plasma B to approximately 1.2, 4, and 10 micrograms/dl, we studied basal ACTH and B at trough (AM) and peak evening (PM) times of the diurnal cycle, as well as the responses to the stress of restraint and blood collection from the tail at each time of day. We also determined mean daily plasma B, insulin, a...
Development and application of a reversed-phase high-performance liquid chromatographic method for quantitation and characterization of a Chikungunya virus-like particle vaccine

To effectively support the development of a Chikungunya (CHIKV) virus-like particle (VLP) vaccine, a sensitive and robust high-performance liquid chromatography (HPLC) method that can quantitate CHIKV VLPs and monitor product purity throughout the manufacturing process is needed. We developed a sensitive reversed-phase HPLC (RP-HPLC) method that separates capsid, E1, and E2 proteins in CHIKV VLP vaccine with good resolution. Each protein component was verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry (MS). The post-translational modifications on the viral glycoproteins E1 and E2 were further identified by intact protein mass measurements with liquid chromatography-mass spectrometry (LC-MS). The RP-HPLC method has a linear range of 0.51-12 μg protein, an accuracy of 96-106% and a precision of 12% RSD, suitable for vaccine product release testing. In addition, we demonstrated that the RP-HPLC method is useful for characterizing viral glycoprotein post-translational modifications, monitoring product purity during process development and assessing product stability during formulation development.
Tetrahydroisoquinoline alkaloids of the Mexican columnar cactus Pachycereus Weberi

Abstract Eight tetrahydroisoquinoline alkaloids have been crystallized and identified from the nonphenolic and phenolic extracts of the giant Mexican cereoid cactus, Pachycereus weberi (Coult.) Br. and R. The identities were established as 5,6,7-trimethoxy-1,2,3,4- tetrahydroisoquinoline (nortehuanine) 1; 7,8-dimethoxy-1,2,3,4-tetrahydroisoquinoline (lemaireocercine) 2; 7-methoxy-1, 2,3,4-tetrahydroisoquinoline (weberidine) 3; 5,6,7,8-tetramethoxy-1,2,3,4-tetrahydroisoquinoline (weberine) 4; 6,7- dimethoxy-1,2,3,4-tetrahydroisoquinoline (heliamine) 5; 2-methyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (N- methylheliamine or oxymethyl-corypalline) 6; 2-methyl-5,6,7-trimethoxy-1,2,3,4-tetrahydroisoquinoline (tehuanine) 7; and 1,2-dimethyl-6,7-dimethoxy-8-hydroxy-1,2,3,4-tetrahydroisoquinoline (pellotine) 8. Compounds 1- 4 have not been identified previously as natural compounds, while compounds 5-8 are previously known cactus alkaloids.
Thermochemistry of rare-earth trifluorides II. Estimation of standard enthalpies of formation

Using the most recent crystallographic data, the Born-Lande equation was employed to calculate lattice energies of the rare-eath trifluorides. The excellent agreement ( (1) and the Born-Lande calculational routine, all the unmeasured enthalpies of formation, (Δ H o f (MX 3 , c, 298.15 K), can be estimated. The magnitude of the monotonic change of Δ H o f (MX 3 ) for the rare-earth trihalides series (14 4f electrons) is comparable to the energy change between Sc and Ti in which only one 3d electron is added. This energy change is consistent with the chemical evidence that the electrons in the f-orbitals of rare earths contribute negligibly to the bonding.
A cognitive-behavioral group treatment of bulimia

This study evaluated a cognitive behavioral group treatment with bulimics. All 13 participants met the DSM-III-R criteria for bulimia nervosa. A multiple baseline design was used with three groups that received the same treatment. The duration of baseline varied for each group: 2, 6, and 10 weeks. The two primary dependent variables were daily self-reports of binging and purging. Five additional outcome measures were used to provide corroboration and to assess broader psychopathology and cognitive changes. Significant reductions in binging and purging occurred between baseline and the end of treatment and between baseline and three weeks post discharge. When data from one outlier were eliminated, those reductions were also maintained at three months post discharge. The five additional variables also showed consistent and meaningful clinical improvements. The results support the value of using a cognitive behavioral approach in group treatment with bulimics.
Albuminuria predicting outcome in diabetes: incidence of microalbuminuria in Asia-Pacific Rim.

Albuminuria predicting outcome in diabetes: Incidence of microalbuminuria in Asia–Pacific Rim. Microalbuminuria is not an unusual finding in the general population, even in individuals without diabetes, hypertension, or cardiovascular risk factors. Prevalence studies in the United States, such as NHANES III, reported an overall incidence of microalbuminuria in 22,244 patients, with and without diabetes, of 7.8%. In those individuals with diabetes, the prevalence was 28.8%. Even in patients without diabetes, cardiovascular disease, or abnormal serum creatinine levels, the prevalence of microalbuminuria was still 5.1%. Similarly, a large Dutch study of 41,000 participants demonstrated a 7% incidence of microalbuminuria. In those individuals with diabetes, the microalbuminuria rate was 16%. Thus, in both the United States and Europe, prevalence studies indicate that microalbuminuria is not uncommon. In southeast Asia and the western Pacific, the incidence of type 2 diabetes is rapidly escalating. It is expected that by 2025 the major prevalence of type 2 diabetes in the world will not be in North America or Europe but in Asia–Pacific Rim. Consequently, there is great interest in evaluating the incidence of microalbuminuria in this region. In the Microalbuminuria Prevalence Study (MAPS) the prevalence of macroalbuminuria was noted to be 18.8% and microalbuminuria 39.8% in a total of 6800 hypertensive diabetic adult patients from 10 Asian countries. Thus, there is important evidence that the substantial prevalence of microalbuminuria and macroalbuminuria in the Pacific region indicates an impending pandemic of diabetic cardiovascular and renal disease.
Linear stability of high-speed mixing layers

Abstract A newly developed spectral compressible linear stability code (SPECLS) is presented for analysis of shear flow stability and applied to high-speed boundary layers and free shear flows. The formulation utilizes the first application of a staggered mesh for a compressible flow analysis by a spectral technique and a multi-domain spectral discretization (MDSPD) option to resolve highly irregular structures. An order of magnitude less number of points is needed for equivalent accuracy in disturbance growth rates compared to calculations by a finite difference formulation, and a factor of three fewer points is required by the MDSPD relative to a single-domain spectral discretization (SPSPD). The mean flow in this study consists of two parallel gases, one of which is quiescent. A sudden appearance of multiple supersonic modes is found to occur near Mach 3. Their existence has not been observed in past studies. This occurence is attributed to the boundary conditions which impose zero perturbations (reflecting boundary conditions) of all disturbances in the far field. The condition is imposed sufficiently far that subsonic disturbances are unaffected (i.e., results match the case of an unbounded free shear layer). However, at approximately Mach 2 there are radiating solutions (supersonic disturbances) both above and below the shear region. The imposed “wall” far-field condition causes a multiplicity of higher supersonic modes at Mach numbers exceeding two. The issue of relevance in studying the stability of a free shear flow is the impact of transition on fuel-air mixing efficiency in scramjet combustors. The bounded free shear layer in this study is the proper analogue of this situation. In particular the observation of a pronounced drop in mixing efficiency as Mach number is increased may be related to these multiple modes which have very low growth rates relative to the subsonic disturbances which predominate at low Mach numbers. At M ∞ = 3 it is found that increasing the temperature of the quiescent gas relative to the injected gas in the mixing layer inhibits the development of these supersonic modes for low streamwise wave numbers. Verification of the method will be given for the case of boundary layers using an existing finite difference compressible stability code, and by comparison with analytical results obtained for free shear flows.
1524 GASTROESOPHAGEAL REFLUX (GER) TO THE PROXIMAL ESOPHAGUS IN NEWBORN INFANTS

GER and aspiration may be associated with apnea and may aggravate chronic lung disease in some infants but there is little information on GER in the newborn. We studied GER to the proximal (rather than distal) esophagus since this would detect refluxed material that might reach the larynx and its chemoreceptors or be aspirated. We studied 9 infants without clinical GER or risk factors felt to increase GER. The gastric pH was <4 in all patients. The tip of the probe was placed at the level of the 1st or 2nd thoracic vertebra. All babies were fed dextrose water to maintain a low gastric pH and were positioned supine or on their sides for the duration of the study. Gestational age ranged from 25-41 wks., birthweight 780-3920 g and postconceptional age 34.4-48.8 wks. Results (mean±SD): When compared with published data of GER to the distal esophagus in older children, GER to the proximal esophagus in newborns is a much more frequent event.
Submonolayer growth in the presence of defect sites

Submonolayer epitaxy in the presence of defect sites on the substrate is studied by means of a level-set method. Here, island nucleations occur by the creation of dimers and defect-monomer pairs. We present results for the scaled island size distribution (ISD) for growth with different densities for both random and regularly positioned defects. The dynamics show that for large D/F and defect density, all islands are nucleated at the defect sites in the very early stages of growth. We use scaling ideas to show that a gamma distribution can suitably describe the ISD. � 2004 Elsevier B.V. All rights reserved.
Evidence for a capping enzyme with specificity for the trypanosome spliced leader RNA.

Capping of the pre-mRNA 5′ end by addition a monomethylated guanosine cap (m7G) is an essential and the earliest modification in the biogenesis of mRNA. The reaction is catalyzed by three enzymes: triphosphatase, guanylyltransferase, and (guanine N-7) methyltransferase. Whereas this modification occurs co-transcriptionally in most eukaryotic organisms, trypanosomatid protozoa mRNAs acquire the m7G cap by trans-splicing, which entails the transfer of the capped spliced leader (SL) from the SL RNA to the mRNA. Intriguingly, the genomes of all trypanosomatid protozoa sequenced to date possess two distinct proteins with the signature motifs of guanylyltransferases: TbCGM1 and the previously characterized TbCE1. Here we provide biochemical evidence that TbCgm1 is a capping enzyme. Whereas RNAi-induced downregulation of TbCe1 had no phenotypic consequences, we found that TbCGM1 is essential for trypanosome viability and is required for SL RNA capping. Furthermore, consistent with co-transcriptional addition of the m7G cap, chromatin immunoprecipitation revealed recruitment of TbCgm1 to the SL RNA genes.
Feasibility of Cyclic CO2 Injection for Light-Oil Recovery

In this paper field performance trends are presented for cyclic CO{sub 2} injection in light-oil sandstone reservoirs. Results indicate that the mass of CO{sub 2} injected is the best predictor of stimulated oil production rate and ultimate incremental recovery. The correlations enhance understanding of the single-well process, improve reservoir selection criteria, and suggest operational guidelines.
Equalization of the Complex Reflection Coefficients for the Parallel and Perpendicular Polarizations of an Absorbing Substrate Coated by a Transparent Thin Film

By coating an absorbing substrate of complex refractive index n 2 − jk 2 with a transparent thin film of certain refractive index n 1 and (normalized) thickness ζ, the complex reflection coefficients R p and R s for the p and s polarizations can be equalized (R p = R s) at a given angle of incidence φ. Consequently, such a film-substrate system reflects incident monochromatic light without any change of polarization, for all incident polarizations. The constraint on n 1,n 2 and k 2, such that R p = R s at a given φ, is studied numerically and graphically. The constraint is found to be virtually independent of φ, and a highly accurate, φ-free, analytical approximation is determined. The associated film thickness ζ and the polarization-independent intensity reflectance R of the film-substrate system are examined as functions of the optical constants. ζ is also found to be virtually invariant with φ, and a highly accurate explicit expression that specifies its dependence on n 1,n 2 and k 2 is given. ℜ has an...
The outs and ins of transposition: from Mu to Kangaroo

Transposons are ubiquitous in prokaryotic and eukaryotic organisms and are major determinants of genome structure. Transposition — the movement of discrete segments of DNA without a requirement for homology — occurs by a handful of mechanisms that are used over and over again in different combinations. Understanding these mechanisms provides an important key to unlocking the secrets of genome organization and evolution.
Scaling relations for hadron charge exchange continuum scattering from carbon

Abstract Two scaling relations, familiar from analyses of electron scattering and successful over limited kinematic ranges for hadron scattering, are applied to 45 charge exchange spectra from beams of protons and pions on carbon. As with scattering without charge exchange, the conditions that underlie scaling analyses of quasifree scattering are in doubt for intermediate energy hadron beams, and scaling analyses are tests of strong assumptions. Scaling for charge exchange reactions is found in the sense that scaled responses for both beam species and all beam energies are in near agreement over a limited but useful range of momentum transfers, especially at small energy losses where nucleon dynamic effects are strong.
Temperature dependence of phase-conjugate response times of semiconductor-doped glasses

Direct experimental evidence shows that the low-power optical phase-conjugation efficiencies and decay times of semiconductor-doped glasses are strongly influenced by the sample temperature. The decay time of the phase-conjugate signal is found to be a single exponential at room temperature and a biexponential at 100 K. A mechanism that is commensurate with the experimental data is discussed.
Electrochemical analysis of cyclopentadienylmetal carbonyl dimer complexes: Insight into the design of hydrogen-producing electrocatalysts

Abstract Four organometallic compounds of the type [Cp2M2(CO)n] (M = Fe, Ru, Mo, W) were evaluated electrochemically to probe the impact of variations in metal composition on ability to catalyze the deprotonation of weak acids, for the evolution of molecular hydrogen. The tungsten and molybdenum complexes undergo a less negative initial reduction, but provide no improvement for overpotential of dihydrogen evolution compared to iron when using 4-tert-butylphenol (pKa = 27.5) as a proton source Catalysis is thought to occur via protonation of the anions formed from the reduction of the dimers studied. The W-based anion catalyst represents the first example of a W-based organometallic hydrogen-producing electrocatalyst.
Role of the Triplet State in the Photoreduction of Chlorophyll

IN 1948, Krasnovsky reported1 that chlorophyll can be photochemically reduced, in dry pyridine, by ascorbic acid. The product is a pink pigment. The quantum yield of the reaction was not measured; but indirect evidence2 indicates that it was of the order of magnitude of 10−2. The reaction is reversible; the green colour of the solution returns slowly on standing, or more rapidly if a suitable oxidant is added. The regeneration of chlorophyll is never complete; part of it being converted into phaeophytin. This and analogous photochemical reactions were studied extensively, in subsequent years3, by Krasnovsky and Evstigneev et al. They have adopted the view that the reversible photoreduction of chlorophyll plays an essential part in photosynthesis and in chlorophyll-sensitized reactions in vitro.
Stress and Immune Dysfunction in Gulf War Veteransa

: The role of stress and immunological abnormalities, as well as the neuroendocrine regulation of these two variables, in illnesses in Gulf War veterans (GWVs) is unknown. Many GWV patients complain of skin and joint problems, that is, disorders that may have a common immunological basis. Post-traumatic stress disorder (PTSD), an anxiety disorder associated with chronic stress, is diagnosed in approximately 10% of the Alabama GWVs. Chronic stress can lead to a reduced capacity to resist disease. Recent work suggests that a dysregulated balance of cytokines produced by T helper cells of the immune system can play a significant role in stress-related illnesses. Indeed, a balanced immune response (cell-mediated and humoral immunity) is an important defense mechanism, and cytokines can regulate this balance. It is therefore plausible that stress-induced changes in hormones (such as cortisol and catecholamines) and cytokines, both of which have been implicated in altering levels of cellular or humoral immunity, may play a role in GWV illnesses.
High and low molecular weight fractions of humic and fulvic acids

The present investigation was initiated to study molecular weight fractionation of humic compounds isolated from surface samples of an Ultisol (Red Yellow Pc lzolic soil) and a Spodosol (Podzol), using fine (mol. wt. cutoff 3500) and coarse (mol. wt. cutoff 12000) dialysis membranes and sephadex gel filtration. Characterization of the humic fractions was conducted by elemental analysis and infrared spectroscopy. The results confirmed that fulvic acid (FA) was higher in ash and elemental content than humic acid (HA). With careful purification the amount of ash was found to be reduced to a minimum, but not to zero. Sephadex gel filtration revealed that fine HA (obtained with fine membranes) was composed of smaller amounts of HA-I (high mol. wt.) and large amounts of HA-II (low mol. wt. fraction). Coarse HA (obtained with coarse membranes) had almost equal amounts of HA-I and HA-II. Fine or coarse FA yielded only low molecular weight components after elution through sephadex. Infrared spectra of the humic fractions were indicative for the presence of phosphoglyceric acid as a possible constituent of the low molecular weight fraction of humic compounds.
Deriving surface ultraviolet radiation from CERES surface and atmospheric radiation budget: Methodology

[1] We describe an algorithm that retrieves the surface UVB (280–315 nm) and UVA (315–400 nm) irradiances from the Surface and Atmosphere Radiation Budget (SARB) product of Clouds and the Earth's Radiant Energy System (CERES). The SARB product we use here routinely calculates the vertical profiles of shortwave, longwave, and window channel irradiances with inputs of retrievals from imagers collocated with CERES. The top of the atmosphere broadband irradiance from SARB is constrained by CERES broadband irradiance. The shortwave spectrum in the SARB calculation is divided into 15 bands, and the two ultraviolet spectral bands, band 5 (298.5–322.5 nm) and band 6 (322.5–357.5 nm), are used to generate surface UVB and UVA irradiances. In this study, we develop a set of ratio lookup tables to derive surface UVB and UVA irradiances from SARB band 5 and band 6 outputs. We show that the ratio of band 5 to UVB irradiance is sensitive to total column ozone, solar zenith angle, surface albedo, and the atmospheric profile in cloud-free conditions; in cloudy conditions, the ratio of band 5 to UVB irradiance is also sensitive to cloud optical depth and height. Additionally, we show that the ratio of band 6 to UVA irradiance is sensitive to solar zenith angle, surface albedo, and cloud optical depth. We also derive a UV index from the UVB irradiance. Our algorithm may be applied at any surface elevation or surface type, including snow and ice. Surface UV irradiances derived from the lookup table that we created agree well with those computed by the high-resolution, multistream radiative transfer code, with differences ranging from −10% to +4% for UVB and UVA irradiances. The relative differences for the UV index are higher, ranging from −26% to +16%.
Abstract IA18: Mapping cancer origins

Histologically similar cancers respond differently to treatment. Consequently, significant populations of cancer patients continue to suffer morbidity and mortality while others with apparently similar tumors are cured. Understanding the biology that drives this heterogeneity is crucial if we are to develop effective treatments for all patients. Advanced genomic technologies have enabled us to divide cancer patients into distinct subgroups, often with different prognoses. However unmasking the mechanisms that generate these molecular subgroups has proven difficult, since their defining genetic alterations are often numerous, and the cellular origins of most cancers remain unknown. This talk will describe a series of recent and ongoing studies in which cross-species genomics approaches have been used to define the cellular and molecular origins of subgroups of brain tumors. By mapping regional and developmental patterns of human brain tumor subgroup gene expression in the developing mouse nervous system, it has been possible to identify variants of normal neural stem cells that share remarkably similar transcriptomes. These similarities in transcriptome reveal candidate cells of origin with a biologic ‘groundstate’ that is highly susceptible to transformation into the corresponding tumor type. Introduction of gene mutations into transcriptome-matched, but not other, normal mouse NSCs generated accurate tumor models of the corresponding human brain tumor subgroup. These models can then be used in high-throughput drug screens to identify subgroup specific treatments. Citation Format: Richard J. Gilbertson. Mapping cancer origins. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr IA18.
Circular Chloroplast Chromosomes: The Grand Illusion

If we could extract, purify, and visualize the intact DNA molecules from chloroplasts, what would those molecules look like? Most would expect to find circular DNA molecules the size of the chloroplast genome. By contrast, however, only a small fraction of the DNA obtained from chloroplasts is found
Design of a 4,600-cps alternator

TO PROVIDE EXCITATION for a magnetic amplifier operating at a 400-cps signal carrier frequency, a single-phase generator of at least 10 times carrier frequency was needed. This digest describes the design and test performance of a machine rated at 240 volts, 6 amperes at unity power factor, 4,600 cps, 158 poles, 3,500 rpm.
Modeling a central place system with interurban transport costs and complex rural hinterlands

Abstract Central place models have made important contributions to the theory of systems of cities by providing interesting insights to the hierarchical structure and location pattern of cities. However, they have been criticized for lack of economic foundations. Following the traditional central place framework, this paper develops a spatial equilibrium model of a system of cities, and emphasizes the spatial dimension of their hinterlands by modeling interurban transport costs and nonuniform two-dimensional rural areas. The model considers only two levels of cities in order to examine the mechanism of forming a central place structure. Given various sets of exogenous parameters pertaining to the production of agricultural and various industrial goods, people's consumption preferences and transportation technologies, the model is solved numerically, and response functions are estimated and analyzed. In the context of spatial equilibrium, we can explain what determines the number of cities, their sizes and location pattern, as well as the wage rates and prices of various goods in the system.
An atlas of selected beta-ray spectra and depth-dose distributions in lithium fluoride and soft tissue generated by a fast Monte Carlo-based sampling method

A method to generate depth-dose distributions due to beta radiation in LiF and soft tissue is proposed. In this method, the EGS4 Monte Carlo radiation transport code is initially used to generate a library of monoenergetic electron depth-dose distributions in the material for electron energies in the range of 10 keV to 5 MeV in 10 keV increments. A polynomial least-squares fit is applied to each distribution. In addition, a theoretical model is developed to generate beta-ray energy spectra of selected radionuclides. A standard Monte Carlo random sampling technique is then employed to sample the spectra and generate the depth-dose distributions in LiF and soft tissue. The proposed method has an advantage over more traditional methods in that the actual radiation transport in the media is performed only once for a set of monoenergetic cases and the beta depth-dose distributions are easily generated by sampling this previously-acquired database in a matter of minutes. This method therefore reduces the demand on computer resources and time. The method can be used to calculate depth-dose distribution due to any beta-emitting nuclide or combination of nuclides with up to ten beta components.
Recycling Endosomes Supply AMPA Receptors for LTP

Long-term potentiation (LTP) of synaptic strength, the most established cellular model of information storage in the brain, is expressed by an increase in the number of postsynaptic AMPA receptors. However, the source of AMPA receptors mobilized during LTP is unknown. We report that AMPA receptors are transported from recycling endosomes to the plasma membrane for LTP. Stimuli that triggered LTP promoted not only AMPA receptor insertion but also generalized recycling of cargo and membrane from endocytic compartments. Thus, recycling endosomes supply AMPA receptors for LTP and provide a mechanistic link between synaptic potentiation and membrane remodeling during synapse modification.
A Theory for the Neural Basis of Language Part 2: Simulation Studies of the Model.

A theory and corresponding model for the neural basis of language was presented in part 1 of this paper. Computer simulation studies of the proposed model are presented here. Processes demonstrated are (1) verbally directed recall of visual experience; (2) understanding of verbal information; (3) aspects of learning and forgetting; (4) the dependence of recognition and understanding on context; and (5) elementary concepts of sentence production. A particular choice of control functions for the model are described, and algorithms for all major computational processes are given. All programming was done in FORTRAN IV and executed on an IBM 360/65 computer.
Xe chemical shift tensor in silicalite and SSZ-24.

We report, for the first time, a theoretical prediction of the 129Xe nuclear magnetic resonance chemical shift tensor of xenon atom in a single crystal of silicalite at near-zero occupancy and the temperature dependence of the Xe NMR chemical shift tensor for the polycrystalline silicalite at maximum occupancy. The former is a measure of the sensitivity of the Xe tensor components to the local structure of the channels without Xe−Xe contributions. The latter is a measure of the sensitivity of the Xe−Xe tensor components to the Xe−Xe distributions, as determined by the Xe−Xe potential function in competition with the Xe−silicalite potential function. Both theoretical predictions can be compared against Xe NMR experiments: the first against the Xe spectra collected as a function of rotation of the single crystal about the three crystalline axes in a magnetic field, and the second against variable temperature Xe NMR studies (below room temperature) of polycrystalline silicalite at maximum Xe occupancy. With...
Psychopathology and personality characteristics of nonclinical compulsive checkers.

Abstract The study of compulsive behavior among individuals with no apparent psychopathology may provide useful information about the nature and genesis of such behavior. Recent studies have suggested important differences between nonclinical checkers and noncheckers which may be related to their checking behavior (Sher, Frost and Otto, 1983; Sher, Mann and Frost, 1984). The two studies reported here examined the extent to which nonclinical compulsive checkers display characteristics of personality and psychopathology which are related to obsessive-compulsive behavior. A number of important differences were found, most of which could not be attributed to general compulsiveness. These differences were consistent with the hypothesis that among nonclinical S s, checking behavior is a reaction to general distress and may represent attempts to reestablish control over the environment.
High-Performance Computing in High Schools?

If high-performance computing in community colleges seems odd, HPC in high schools is even stranger. This article will help readers grok the nature of the author's version of high school HPC.
Modeling Pipeline Driving Behaviors: Hidden Markov Model Approach

Driving behaviors at intersections are complex. At intersections, drivers face more traffic events than elsewhere and are thus exposed to more potential errors with safety consequences. Drivers make real-time responses in a stochastic manner. This study used hidden Markov models (HMMs) to model the driving behavior of through-going vehicles on major roads at intersections. Observed vehicle movement data were used to estimate the model. A single HMM was used to cluster movements when vehicles were close to the intersection. The reestimated clustered HMMs could more accurately predict vehicle movements compared with traditional car-following models.
Ambient Particulates Alter Vascular Function through Induction of Reactive Oxygen and Nitrogen Species

Previous studies have shown a link between inhaled particulate matter (PM) exposure in urban areas and susceptibility to cardiovascular diseases. Although an oxidative stress pathway is strongly implicated, the locus of generation of reactive oxygen species (ROS) and the mechanisms by which these radicals exert their effects remain to be characterized. To test the hypothesis that exposure to environmentally relevant inhaled concentrated ambient PM (CAPs) enhances atherosclerosis through induction of vascular ROS and reactive nitrogen species. High-fat chow fed apolipoprotein E –/– mice were exposed to CAPs of less than 2.5 mm (PM2.5) or filtered air (FA), for 6 h/day, 5 days/week, for 4 months in Manhattan, NY. Atherosclerotic lesions were analyzed by histomorphometricly. Vascular reactivity, superoxide generation, mRNA expression of NADPH (nicotinamide adenine dinucleotide phosphate, reduced) oxidase subunits, inducible nitric oxide synthase, endothelial nitric oxide synthase, and GTP cyclohydrolase I were also assessed. Manhattan PM2.5 CAPs were characterized by higher concentrations of organic and elemental carbon. Analysis of vascular responses revealed significantly decreased phenylephrine constriction in CAPs-exposed mice, which was restored by a soluble guanine cyclase inhibitor 1H[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one. Vascular relaxation to A23187, but not to acetylcholine, was attenuated in CAPs mice. Aortic expression of NADPH oxidase subunits (p47 phox and rac1) and iNOS were markedly increased, paralleled by increases in superoxide generation and extensive protein nitration in the aorta. The composite plaque area of thoracic aorta was significantly increased with pronounced macrophage infiltration and lipid deposition in the CAPs mice. CAPs exposure in Manhattan alters vasomotor tone and enhances atherosclerosis through NADPH oxidase dependent pathways.
Urban neighbourhood unemployment history and depressive symptoms over time among late middle age and older adults

Background Little is known about how a neighbourhood9s unemployment history may set the stage for depressive symptomatology. This study examines the effects of urban neighbourhood unemployment history on current depressive symptoms and subsequent symptom trajectories among residentially stable late middle age and older adults. Contingent effects between neighbourhood unemployment and individual-level employment status (ie, cross-level interactions) are also assessed. Methods Individual-level survey data are from four waves (2000, 2002, 2004 and 2006) of the original cohort of the nationally representative US Health and Retirement Study. Neighbourhoods are operationalised with US Census tracts for which historical average proportion unemployed between 1990 and 2000 and change in proportion unemployed between 1990 and 2000 are used to characterise the neighbourhood9s unemployment history. Hierarchical linear regressions estimate three-level (time, individual and neighbourhood) growth models. Results Symptoms in 2000 are highest among those residing in neighbourhoods characterised by high historical average unemployment beginning in 1990 and increasing unemployment between 1990 and 2000, net of a wide range of socio-demographic controls including individual-level employment status. These neighbourhood unemployment effects are not contingent upon individual-level employment status in 2000. 6-year trajectories of depressive symptoms decrease over time on average but are not significantly influenced by the neighbourhood9s unemployment history. Conclusions Given the current US recession, future studies that do not consider historical employment conditions may underestimate the mental health impact of urban neighbourhood context. The findings suggest that exposure to neighbourhood unemployment earlier in life may be consequential to mental health later in life.
A melding of educational strategies to enhance the introductory programming course

The University of South Alabama has for an extended period of time been committed to improving the introductory programming course for Computer Science. These efforts and their results have been supported by the National Science Foundation, assessed by numerous instruments, and have been disseminated in papers, workshops, and conference sessions. Specific topics of this dissemination have included the integration of lecture and laboratory experiences, the use of motivational strategies and affective objectives, student achievement and retention, the early use of professional practices in the curriculum, the development of student affect during the introductory course, the enhancement of laboratory experiences, the application of various learning theories in the classroom, and curriculum design. In contrast to these prior works which each focused on just a few specific issues, the purpose of this paper is to holistically discuss the set of effective strategies used in our introductory programming course and show how these diverse efforts can be melded together and jointly enhance and enliven the course. This set of strategies includes the integration of cognitive and affective course objectives; the use of concept maps and other visual instructional techniques and tools; the use of motivational strategies such as classroom discussion and student self-reflection; the integration of conceptual development and hands-on exercises in the classroom; the designing of course progress to match the students' zone of proximal development; the designing of course delivery methodologies to match the diversity of students' interests and learning styles; the inclusion of diverse strategies to integrate the "real world" into every component of the course; the strategic use of student surveys; and the integration of professional practices and student commitments to quality. A marked, consistent, and significant increase in student course completion rates has accompanied our implementation of these strategies
Tracking Vertex Flow and Model Adaptation for Three-Dimensional Spatiotemporal Face Analysis

Research in the areas of 3-D face recognition and 3-D facial expression analysis has intensified in recent years. However, most research has been focused on 3-D static data analysis. In this paper, we investigate the facial analysis problem using dynamic 3-D face model sequences. One of the major obstacles for analyzing such data is the lack of correspondences of features due to the variable number of vertices across individual models or 3-D model sequences. In this paper, we present an effective approach for establishing vertex correspondences using a tracking-model-based approach for vertex registration, coarse-to-fine model adaptation, and vertex motion trajectory (called vertex flow) estimation. We propose to establish correspondences across frame models based on a 2-D intermediary, which is generated using conformal mapping and a generic model adaptation algorithm. Based on our newly created 3-D dynamic face database, we also propose to use a spatiotemporal hidden Markov model (ST-HMM) that incorporates 3-D surface feature characterization to learn the spatial and temporal information of faces. The advantage of using 3-D dynamic data for face recognition has been evaluated by comparing our approach to three conventional approaches: 2-D-video-based temporal HMM model, conventional 2-D-texture-based approach (e.g., Gabor-wavelet-based approach), and static 3-D-model-based approaches. To further evaluate the usefulness of vertex flow and the adapted model, we have also applied a spatial-temporal face model descriptor for facial expression classification based on dynamic 3-D model sequences.
Implicit treatment of substrate and power-ground losses in return-limited inductance extraction

Full-wave analysis, based on rigorous solution of the differential or integral form of Maxwell's equations, is too slow for all but the smallest designs. Traditional on-chip extraction engines are, therefore, being pushed to extract inductance and provide accurate high-frequency interconnect modelling while maintaining computational efficiency and capacity. This paper describes further accuracy-improving enhancements to the commecial full-chip RLCK extraction engine, Assura RLCX[1], based on the return-limited inductance formulation. Specifically, we incorporate substrate losses due to eddy currents and power-ground losses while, based on design-driven assumptions, avoiding explicit extraction of the power-ground and substrate. Results are validated on small testcases where comparison with full-wave solution is practical.
Screening for obstructive sleep apnea in patients with bipolar I disorder: comparison between subjective and objective measures.

Objectives Many of the first-line screening tools for obstructive sleep apnea (OSA) may not be accurate in patients with bipolar disorder due to confounding factors, such as chronic depressive symptoms, weight gain, and sedation due to medications. In the present study, we assessed the feasibility of in-home screening for sleep apnea in patients with bipolar disorder and assessed the validity of a screening questionnaire versus an objective measure of apnea-hypopnea index (AHI). Methods A total of 28 subjects with bipolar I disorder (19 females,and nine males; mean age 41.7 ± 9.8 years) completed the Berlin Questionnaire for sleep apnea screening and their AHI was objectively measured with a portable in-home device. Results Eleven subjects (39%) had an AHI ≥ 5. The Berlin Questionnaire showed a poor positive and negative predictive value for identifying sleep apnea in patients with bipolar disorder. Conclusions While OSA may be relatively prevalent among patients with bipolar disorder, self-report screening tools used in clinical practice may be highly inaccurate for this population. In-home screening with a patient-operated monitoring device may be a valid and feasible alternative for patients with bipolar disorder.