cssi/SciSciGPT-SciSciNet huggingface dataset:
Online learning with social computing based interest sharing

Communities on the Internet are highly self-organizing, dynamic, and ubiquitous. One objective of peers in such a community is sharing common interests, even when compromising privacy. This paper presents a model for peers on the Internet that allows them to discover their common interests in terms of sets of frequently visited URLs. This model assists online learning by automatically presenting users with URLs related to what they are currently browsing, thus saving users’ time searching for additional information and helping to educate them on the current topic. To implement the model and collect test data, FireShare was developed as a plugin for the popular Web browser Firefox. Data was collected and analyzed on the number of discovered frequently visited URL sets, relevancy of mined association rules, and the overhead FireShare imposes on a network. While FireShare favorably validated the proposed model, analysis of the submitted test data shows high potential for success with future versions.
Physical mapping of loci in the distal half of the short arm of the human X chromosome: implications for the spreading of X-chromosome inactivation.

The relative order of 11 loci in the distal half of the short arm of the human X chromosome was examined using a panel of somatic cell hybrids containing structurally rearranged X chromosomes. The results show that the gene for phosphoribosylpyrophosphate synthetase 2 (PRPS2) is located betweenZFX (zinc finger protein, X-linked) andSTS (steroid sulfatase). The results also confirm the localization ofZFX distal toPOLA (α-DNA polymerase). Previous studies have shown thatSTS andZFX escape X-inactivation whereasPOLA undergoes inactivation. Evaluation ofPRPS2 expression in somatic cell hybrids containing inactive human X chromosomes showed thatPRPS2 undergoes X-inactivation. These results provide further evidence for interspersion of loci that do and do not undergo X-inactivation on the human X chromosome.
Human LBP-32/MGR is a Repressor of the P450scc in Human Choriocarcinoma Cell Line JEG-3

Steroid hormones regulate a wide range of physiologic functions in humans. The cholesterol side-chain cleavage enzyme P450scc regulates the initial step of biosynthesis of all steroid hormones. We investigated the expression of P450scc by studying a potential regulator of P450scc, LBP-32/MGR. Using a Northern blot, we found that LBP-32/MGR mRNA was expressed mainly in the human placenta. Using radiation hybrid mapping, we identified LBP-32/MGR on human chromosome 2p25. Recombinant LBP-32/MGR protein bound preferentially to a DNA fragment from the promoter of P450scc in vitro and exhibited clear nuclear localization in transfected cells. Luciferase reporter gene assays showed that LBP-32/MGR specifically repressed transcriptional activation of the human P450scc promoter. Because placental P450scc expression is essential for pregnancy and steroid biosynthesis, the placental expression and transcriptional repressor activity of LBP-32/MGR in JEG-3 cells suggest it has a role as a transcriptional modulator of steroid biosynthesis.
Socioeconomic and Racial Differences in Treatment for Breast Cancer at a Low-Volume Hospital

Purpose Population-based studies have revealed higher mortality among breast cancer patients treated in low-volume hospitals. Other studies have demonstrated disparities in race and socioeconomic status (SES) in breast cancer survival. The purpose of our study was to determine whether nonwhite or low-SES patients are disproportionately treated in low-volume hospitals.
Overlooked care transitions: an opportunity to reduce acute care use in ESRD.

A major goal of United States health care reform is to reduce hospital readmissions. In 2012, approximately 18% of Medicare patients discharged from the hospital were readmitted within 30 days ([1][1]). According to one estimate, readmissions cost the Medicare program >$17 billion in 2004 ([2][2]).
Symbolic threat and social dominance among liberals and conservatives: SDO reflects conformity to political values

Three studies tested the effects of symbolic threat to group values and strength of ingroup (political party) identification on social dominance orientation (SDO), a measure of tolerance for social hierarchies. In Studies 1 and 3, conservative participants were made to feel as though their group’s values were either threatened or not threatened by liberals prior to completing theSDOmeasure.InStudies 2and 3,liberalparticipants were made tofeelas thoughtheirgroup’svalues were either threatened or not threatened by conservatives prior to completing the SDO measure. Results demonstrated that high ingroup (political party) identification was associated with high SDO scores for threatened conservatives, and with low SDO for threatened liberals. These findings suggest that in response to symbolic threat, SDO can shift in directions consistent with protecting the ingroup’s identity. Copyright # 2009 John Wiley & Sons, Ltd.
Phenanthrene binding and sorption to dissolved and to mineral-associated humic acid

Abstract Phenanthrene, a three ring aromatic hydrocarbon, was used as a model substrate to distinguish between binding and sorption to dissolved and to mineral-associated humic acid (HA), with an emphasis on its implication to bioavailability. Binding was analyzed by a fluorescence quenching technique using Aldrich HA and HAs derived from compost, loamy and clay loamy soils. Measurements were made both in buffered water and in a mineral medium to be used later in a bioavailability study. Sorption of phenanthrene to mineral-associated HA was analyzed in batch experiments. Mineral–HA complexes were prepared with goethite, hematite, and Ca2+- and Cu2+-montmorillonite. Interaction of HA with clay minerals was greater at low pH and was dependent on the mineral type. Sorption of phenanthrene to these complexes was substantially higher at lower pH and higher when the HA was associated with montmorillonite rather than goethite or hematite. Binding coefficients (Kb(oc)) obtained for dissolved HA were at least an order of magnitude higher than sorption coefficients (Kp(oc)) obtained for mineral-associated HA. Both binding and sorption coefficient values were substantially higher for Aldrich HA. This work emphasizes the need for a detailed sorption study before conducting well controlled bioavailability experiments.
Hyperbolic umbilic and E 6 diffraction catastrophes associated with the secondary rainbow of oblate water drops: observations with laser illumination

Previous observations of oblate drops of water illuminated perpendicular to their axis of symmetry exhibit catastrophe patterns near the primary-rainbow scattering angle [see, e.g., Appl. Opt. 30, 3468 (1991). The present research concerns observation of diffraction catastrophes near the secondary-rainbow scattering angle under similar experimental conditions. Illumination with laser light exhibits similar caustic structures in the secondary rainbow including the hyperbolic umbilic focal section and the E6 or symbolic umbilic focal section. The range of drop aspect ratios explored includes aspect ratios as small as those found for freely falling drops in air as well as highly flattened drops. The new features of the secondary rainbow occur for highly flattened drops.
International accounting research: An analysis of thirty-two years from the international journal of accounting

Abstract This study provides a thirty-two year historical perspective of international accounting research by presenting an analysis of the articles that have appeared in the International Journal of Accounting (formerly, the International Journal of Accounting, Education, and Research) and related monographs during the time period 1965 through 1996. The International Journal of Accounting was chosen for this study because it has the longest continuous history of published research in international accounting. It consists of six sections following the introduction. The second section analyzes all 768 articles that have been published in the journal and related monographs. The next three sections analyze the 263 articles devoted to the European region, the 183 articles devoted to the pacific region, and the 126 articles devoted to countries classified by the World Bank (1990) as economically developing, respectively. The analyses in each section classify the articles by research methodology, country, subject, time periods, and authors. The last section contains the conclusion. A completed annotated bibliography of all 768 articles with indexes by author, topic, country, and methodology is available on disk from the author.
Multiplexing BGP sessions with BGP-Mux

This paper describes a BGP-session multiplexer called BGP-Mux, which provides stable, on-demand access to global BGP route feeds. This gateway allows arbitrary and even transient client BGP connections to be provisioned and torn down on demand without affecting globally visible BGP sessions. BGP-Mux provides two capabilities: (1) the ability for a client network to receive multiple unfiltered routes per destination from a set of upstream ASes; and (2) the ability to provision BGP sessions without introducing global instability. Several applications could benefit from these features:
Fabrication of reconfigurable photonic bandgap-MEMS waveguide device

We present the development of a fabrication technique for a semiconductor-based photonic crystal (PhC) nano-membrane device with reconfigurable active waveguides using micro-electro-mechanical systems (MEMS) technology. This device can be used as a basic building block for optoelectronic integrated circuits that can be reprogrammed for different functionalities such as switches, modulators, time delay lines, resonators, etc. The device is fabricated three-dimensionally on GaAs/Al x1 GaAs/Al x2 GaAs epitaxial layers on a GaAs substrate. The device has a top PhC membrane layer structure composed of hexagonal holes in a triangular lattice. Below that, a separate suspended bridge layer can insert a line of posts into the PhC holes to create a defect line. This MEMS feature can generate/cancel a section of the waveguide in the PhC platform, or (by partial removal) it can change the dispersion of the waveguide. Therefore, the same structure can be used as different types of devices. In this paper, we will discuss detailed fabrication processes for such a multi-layer 3D device structure, including e-beam lithography, inductively coupled plasma reactive ion etching, and multiple steps of regular photolithography and selective wet chemical etching. The unique processing sequence allows us to fabricate the multi-layer 3D device structure from one top surface without regrowth, wafer bonding, or access from the back surface. This simplifies the device processing and reduces the fabrication cost.
Use of a percutaneous septal occlusion device to exclude a juxta-renal pseudoaneurysm of the abdominal aorta

Abdominal aortic pseudoaneurysm is an uncommon, but challenging condition. The most common etiologies are either trauma or iatrogenic repair via open surgery, endovascular aortic cuff, and exclusion via placement of coils has been described. We describe a case of a juxta-renal aortic pseudoaneurysm following aorto-bi-iliac bypass grafting that was successfully excluded by endovascular placement of a percutaneous septal occlusion device.
The energy-integral method: application to one-phase hyperbolic Stefan problems

Abstract This paper presents an approximate mathematical technique utilizing the energy-integral method for solving the planar solidification problem of a pure liquid metal occupying the infinite half-space. Assuming a time-dependent relaxation model for the energy flux results in a hyperbolic differential equation for the thermal field which is solved under suitable conditions of both local thermodynamic equilibrium and thermal dynamical compatibility on the interface displacement. In fact, analytical expressions are derived when (a) surface temperature is prescribed; or (b) heat flux at the surface boundary is given. Comparisons of these expressions with corresponding results pertinent to parabolic Stefan problems are made; and finally all the solutions are presented in graphical form.
The Cattleya Fly, (Isosoma) Eurytoma Orchidearum Westwood

This paper is a preliminary account of studies of the life history and control of the Cattlcya Fly, Eurytoma orchidearum Westwood, which has become the most serious pest of the Cattleya group of orchids cultivated in the greenhouses of the United States. The durations of the several stages of the insect are given, and total three and one-half to five months for the complete life cycle of an individual. Suggestions for control involve two methods; removal of all infested growths, and semiweekly dusting for a period of five months with a nicotine-impregnated dust mixed according to the following formula: Kaolin 50 parts Hydrated lime 20 parts Dusting tobacco dust (containing 1 per cent nicotine) ...25 parts 40 per cent nicotine sulphate 5 parts
Structural energetics of thin coherently strained metallic overlayers

Understanding of the growth, stability, and structural properties of coherently strained metal overlayers has achieved considerable importance because of the recent discovery of unique interfacial electronic states and catalytic properties of such systems. The structural stability of coherently strained metal films grown on a substrate composed of a different and lattice-mismatched metal is determined via atomistic calculations. An equilibrium energy balance criterion is used, which is evaluated with a Monte Carlo annealing optimization procedure in which the structural energy of the bimetallic system is obtained using the embedded atom method. The stability of coherently strained (100) bimetallic structures chosen from combinations of the fcc metals Ag, Au, Cu, Ni, Pd, and Pt has been studied. The predicted critical thicknesses agree remarkably well with experimental results, but disagree quantitatively with the continuum models.
Porous Carbon Supports Prepared by Ultrasonic Spray Pyrolysis for Direct Methanol Fuel Cell Electrodes

Carbon powders composed of porous micrometer-sized spheres were synthesized from simple organic salt precursors using ultrasonic spray pyrolysis (USP). These materials were tested as catalyst supports for a direct methanol fuel cell (DMFC) catalyst and as pore formers in a membrane electrode assembly (MEA). The effect of these materials on unit cell performance was evaluated and compared to traditional Vulcan XC-72 carbon nanoparticle powder. USP provides a simple and facile way to prepare porous carbons with various morphologies and pore sizes. In exploring these new morphologies of carbon, two types of micrometer-sized spherical porous carbons were tested as pore-forming additives for both the anode catalyst (i.e., PtRu/C for methanol oxidation) and the cathode catalyst (i.e., Pt/C for O2 reduction). The anode catalyst mixture of PtRu/Vulcan and PtRu/PC-I (weight ratio 2:1, 33 wt % PC-I) showed the highest performance improvement and is attributed to the synergic effect of two carbons (PC-I and Vulcan X...
Modelling of strain histories for memory integral fluids in steady axisymmetric flows

Abstract A path line tracking procedure is derived which determines the strain history of infinitesimal material elements in steady axisymmetric flow. Path line tracking requires a pointwise knowledge of the kinematics as it is gained in numerical calculations (or may be available from measurements). Tabulated values of density as a function of position are also required. Path line tracking then interpolates spatial positions along path lines at residence times ( t — t ′), magnitude of velocity, velocity gradient normal to the path line, and slope of path line at time t . This knowledge is then condensed into the time dependent Finger strain components C −1 ( t ′, t ) for a given material element in steady axisymmetric flow. The tracking is applicable to compressible flows of arbitrarily large strains, since the strain history C −1 is determined for a material point (infinitesimal material element). Path line tracking avoinds differentials in space, except when determining the shear strain and when interpolating between the given point values of velocity. The method is tested in a specific example (planar stagnation flow) and it is applied to modelling of processing flows.
Sustainability of algal biofuel production using integrated renewable energy park (IREP) and algal biorefinery approach

Abstract Algal biomass can provide viable third generation feedstock for liquid transportation fuel. However, for a mature commercial industry to develop, sustainability as well as technological and economic issues pertinent to algal biofuel sector must be addressed first. This viewpoint focuses on three integrated approaches laid out to meet these challenges. Firstly, an integrated algal biorefinery for sequential biomass processing for multiple high-value products is delineated to bring in the financial sustainability to the algal biofuel production units. Secondly, an integrated renewable energy park (IREP) approach is proposed for amalgamating various renewable energy industries established in different locations. This would aid in synergistic and efficient electricity and liquid biofuel production with zero net carbon emissions while obviating numerous sustainability issues such as productive usage of agricultural land, water, and fossil fuel usage. A ‘renewable energy corridor’ rich in multiple energy sources needed for algal biofuel production for deploying IREPs in the United States is also illustrated. Finally, the integration of various industries with algal biofuel sector can bring a multitude of sustainable deliverables to society, such as renewable supply of cheap protein supplements, health products and aquafeed ingredients. The benefits, challenges, and policy needs of the IREP approach are also discussed.
796 DEVELOPMENTAL DELAY IN CHILDREN EXPOSED TO CHLORIDE DEFICIENT FORMULA

During 1978-1979, more than 20,000 infants may have been exposed to chloride-deficient formula (CDF). A number of these children were noted to suffer from severe metabolic alterations, principally hypochloremic metabolic alkalosis (HMA). The present study examined 21 children who were exposed to CDF and developed HMA. Pediatric records were reviewed, medical and feeding histories were obtained from the parents, and children were administered the Bayley Scales of Infant Development (BSID). The range of age at testing was 13 to 29 months (mean=23.2). The Bayley Mental Development Index (MDI) ranged from 67 to 127 (mean=98.5) Length of exclusive use of CDF without supplementation with solids or other milk/formula (LENEXC) had a significant negative correlation with MDI (r=-.55, p=.01). When length of exclusive use of CDF, age of onset of CDF use and age at testing were entered into a multiple regression analysis, LENEXC remained associated with MDI (R2=.39, p<.05). Sixteen of these children were re-examined at ages ranging from 40 to 51 months (mean=43.8) using the McCarthy Scales of Children's Abilities. There was a significant negative correlation between LENEXC and the perceptual-performance scale (r=-.51, p<.05) and between LENEXC and the motor scale (r=-.52, p<.05). These data raise concern about the long-term outcome of these children.
Arithmetic difficulties in females With the fragile X premutation

Females with the fragile X full mutation have been reported to have difficulty learning mathematics. Women with the fragile X premutation often give a history of mathematics difficulties in themselves especially with higher level math. In order to evaluate whether women with the premutation have difficulty with math, we asked women with both the fragile X premutation and full mutation to complete the Wide Range Achievement Test-3. For the group of 39 women with the fragile X premutation, the median standard score on the Arithmetic portion was 93, which was significantly lower (P = 0.001) than the median of the standardized norm of 100. Only nine of the women had Arithmetic scores at or above the 50th centile, while over half of the women had standard scores at or above the 50th centile in Reading and Spelling. The eight women with the full mutation also had lower Arithmetic scores than Reading and Spelling scores. These data suggest that mathematics may be an area of relative weakness for the women with the premutation as well as the full mutation. This possibility should be evaluated further by using other measures. This information is important both for counseling purposes and to understand whether a mathematics deficit is evidence of low expression of the FMR1 gene in the premutation state.
Effect of large particles on the augmentation of wall friction in vertical pneumatic and hydraulic transport in a turbulent fluid

This paper is concerned with prediction of the augmentation of wall friction by large particles (Fp) over that assuming turbulent flow in a pipe without particles (F f ) for vertical pneumatic and hydraulic transport in a turbulent fluid. Our measure of this is the value of the ratio F p /F f . Equations 29 and 32 are derived initially for predicting F p /F f for large particle "parallel" flow pneumatic transport based on the supposition that the particle phase friction factor (f p ) is solely a function of the Froude number, (gD) 1/2 /v where g is the gravitational acceleration, D is the tube diameter, and v is the particle phase velocity. The Froude number, gD/v 2 , is used to derive eq 40, its counterpart for hydraulic transport. These equations are shown to be qualitatively reliable and inconsistent only with the existence of a particle-free zone near the wall observed in experiments for large particle transport. To satisfy this requirement, f p is additionally assumed to be a function of the turbulence response parameter, t R /t e where t R is the particle relaxation time, and t e , the lifetime of the most energetic turbulent eddy. Equations 34 and 41 are our final correlating equations for F p /F f for pneumatic and hydraulic transport, respectively. When t R /t e is large, the particle-wall friction coefficient (f p ) goes to zero to conform with theory and experimental observations.
A quadtree approach to domain decomposition for spatial interpolation in grid computing environments

Spatial interpolation is widely used in geographical information systems to create continuous surfaces from discrete data points. The creation of such surfaces, however, can involve considerable computation, especially when large problems are addressed, because of the need to search for neighbors on which to base interpolation calculations. Computational Grids provide the computing resources to tackle spatial interpolation in a timely way. The objective of this paper is to investigate the use of domain decomposition for a distributed inverse-distance-weighted spatial interpolation algorithm; the algorithm runs using the Globus Toolkit (GT) in a heterogeneous Grid computing environment. The interpolation algorithm is modified for implementation in the Grid by using a quadtree to spatially index and adaptively decompose the interpolation problem to balance processing loads. In addition, the GT allows the distributed algorithm to couple multiple machines, potentially of different architectures, to dynamically schedule the decomposed sub-problems through Globus services and protocols (e.g., resource management, data transfer). Experiments are conducted to test how well this distributed IDW interpolation algorithm scales to heterogeneous grid computing environments using irregularly distributed geographical data sets.
Abstract 3427A: Focal fractionated irradiation induces specific malignancies in a dose-dependent manner in Nf1 mutant mice

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Purpose: Secondary malignant neoplasms (SMNs) are a severe late complication of radiotherapy (RT). However little is known regarding the influence of radiation dose or genetic factors on this risk. Mutations in the NF1 tumor suppressor gene cause neurofibromatosis type I (NF1), and clinical observations suggest that affected persons are at increased risk of developing radiation-induced SMNs. NF1 encodes a GTPase activating protein that negatively regulates Ras signaling networks. We administered fractionated cranial irradiation (CI) to heterozygous Nf1 mutant (Nf1+/−) mice in an effort to accurately model common human SMNs. Materials and Methods: 121 C57BL6-Sv129 Nf1+/− and control wild-type (WT) mice were assigned to one of three CI treatment regimens: 0 Gy, 15 Gy (5 daily doses of 3 Gy), or 30 Gy (10 daily doses of 3 Gy). Results: Mice were observed for 18 months after CI or until they developed signs of disease requiring euthanasia. Kaplan-Meier analyses and log-rank tests demonstrate that Nf1 heterozygosity and radiotherapy are independently associated with significantly greater risks of death after CI (p <, respectively). Whereas 15 Gy and 30 Gy CI are associated with similar rates of death in Nf1+/− mice, there was a remarkable difference in the disease spectrum at each dose. Myeloid malignancies were more likely to arise in Nf1+/− mice that received 15 Gy of CI, compared to Nf1+/− mice that received 30 Gy CI or any wildtype mice. By contrast, Nf1+/− mice receiving 30 Gy of CI succumbed to solid tumors such as squamous cell carcinoma (SCC) or sarcomas developing in the radiation field. These radiation-induced tumors arose at a significantly increased incidence in Nf1+/− mice receiving 30 Gy compared to Nf1+/− mice receiving 15 Gy and all wildtype mice. Cultured radiation-induced tumor cells show hyperactive Ras signaling in response to growth factor stimulation, and are sensitive to inhibitors of the mTOR-S6 kinase signaling pathway in vitro. Conclusion: Nf1+/− mice provide a sensitized genetic background for investigating radiation-induced SMNs. Importantly, these mice develop many of the most common SMNs found in human patients. Nf1+/− mice develop predominately hematologic abnormalities at the 15 Gy dose, while solid tumors predominate at 30 Gy, suggesting that radiation dose thresholds exist for hematologic and non-hematologic cancers. Radiation-induced solid tumors display aberrant Ras signaling and are dependent on downstream signaling for survival in culture. The ability to administer focal fractionated radiation to mice will facilitate studies addressing the pathogenesis of common SMNs and for testing preventive and therapeutic strategies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3427A.
Deep Imaging of the Field of the High-Redshift Radio Source 4C 23.56

We present deep infrared and optical imaging of a 1.25 arcmin2 field centered on the giant (~0.5 Mpc) high-redshift (z = 2.479) ultra-steep-spectrum radio source 4C 23.56. The optical/infrared continuum morphology of the host galaxy is asymmetric, with strong color gradients and an enormous biconical emission-line nebula. The morphology of 4C 23.56 is best described by a dusty galaxy illuminated by a beam from an active galactic nucleus that is scattered into our line of sight. We determine the K' band number counts in the field to a limit of K' = 22.5 mag and find a marginally significant excess of objects with K' = 19-21 mag, compared to other K' band surveys. Spectral energy distributions (SEDs) of 117 objects in the field are constructed from aperture photometry in five bands (U', NB, V, I, and K'). From the SEDs we distinguish three subsets of objects as possible candidates for z ~ 2.48 companions: emission-line galaxies, very red galaxies, and flat-spectrum star-forming galaxies. The field has nine candidate objects with line emission in a narrow band centered on the redshifted Ly? line, compared to an expected number of at most three foreground [O II] emitters that could mimic Ly? sources. We find a high density of faint, very red objects with I-K' > 4 mag in the field, including two with I-K' > 6 mag.
Folate binding site of flavin-dependent thymidylate synthase

The DNA nucleotide thymidylate is synthesized by the enzyme thymidylate synthase, which catalyzes the reductive methylation of deoxyuridylate using the cofactor methylene-tetrahydrofolate (CH2H4folate). Most organisms, including humans, rely on the thyA- or TYMS-encoded classic thymidylate synthase, whereas, certain microorganisms, including all Rickettsia and other pathogens, use an alternative thyX-encoded flavin-dependent thymidylate synthase (FDTS). Although several crystal structures of FDTSs have been reported, the absence of a structure with folates limits understanding of the molecular mechanism and the scope of drug design for these enzymes. Here we present X-ray crystal structures of FDTS with several folate derivatives, which together with mutagenesis, kinetic analysis, and computer modeling shed light on the cofactor binding and function. The unique structural data will likely facilitate further elucidation of FDTSs’ mechanism and the design of structure-based inhibitors as potential leads to new antimicrobial drugs.
Sequence of the V. parahaemolyticus Gene for Cytoplasmic N, N'-Diacetylchitobiase and Homology with Related Enzymes

The nucleotide sequence of the gene encoding the cytoplasmic N, N'-diacetylchitobiase [EC 3.2.1.14] from Vibrio parahaemolyticus (ATCC #27969) has been determined. The deduced peptide sequence of this unusual beta-hexosaminidase surprisingly shows minimum evolutionary relationship to two other reported N, N'-diacetylchitobiases from vibrios, except in highly conserved regions which are also homologous to lysosomal beta-hexosaminidases from eukaryotes including humans. In contrast, the two other beta-hexosaminidases from vibrios with reported sequences are much more closely related to each other. This novel 85 kDa cytoplasmic glycosyl hydrolase with restricted specificity participates in the high level utilization of chitin-derived 2-deoxy-2-acetamido-D-glucose (GlcNAc) by vibrios as one of two parallel pathways for the metabolism of N,N'-diacetylchitobiose [Bassler, B.L., Yu, C., Lee, Y.C., and Roseman, S. (1991) J. Biol. Chem. 266, 24276-24286]. These pathways use chitin-binding proteins for the adherence of the bacterial chitinase to the substrate, and an extracellular chitinase and a periplasmic chitodextrinase to produce N,N'-diacetylchitobiose. The V. parahaemolyticus cytoplasmic N,N'-diacetyl-chitobiase reported herein appears to be a unique protein, lacking a signal sequence, and genetically distant from other known chitinoclastic beta-N,N'-diacetyl-hexosaminidases. This is consistent with its limited substrate specificity to small GlcNAc terminated oligosaccharides and its cytoplasmic rather than periplasmic localization.
Abnormal myocardial capillary perfusion with normal coronary arteries and valvular heart disease

Abstract The demonstration of normal coronary arteries at cardiac catheterization has been considered adequate definition of normal myocardial perfusion. To examine this, we have utilized intracoronary injections of technetium-99 m labeled albumin microspheres in 11 patients with valvular heart disease, and in 13 patients with chest pain syndrome or constrictive pericarditis. Eight patients with valvular heart disease had large, patchy, irregular perfusion deficits noted on the scintiphotos. Only one of thirteen control patients had a perfusion deficit. Caution, therefore, must be used in attributing such perfusion deficits to atherosclerotic disease when valvular disease is present.
Beyond structuralism and voluntarism: The politics and discourse of Progressive school reform, 1890–1930

"When the school introduces and trains each child of society into membership within ... community [life], saturating him with the spirit of service, and providing him with the instruments of effective self-direction, we shall have the deepest and best guarantee of a larger society which is worthy, lovely, and harmonious."' So wrote John Dewey in The School and Society, one of the earliest and most fundamental texts of what was to become the Progressive movement in education. Inspired by Dewey's vision, a wide range of educators, parents, and community leaders came together during the late nineteenth and early twentieth centuries in an impassioned crusade to transform American public schooling. They set out to reduce drastically the size of local school boards and to dismantle structures of "patronage democracy" that then pervaded educational administration. They also implemented, among a host of curricular and pedagogical initiatives, new courses of study in "character education" and "civics." These programs, overlooked today by virtually all educational historians of the period, sought to create a new type of "democratic character," one equipped for responsible citizenship in the new "national community" that was emerging.
Student Speech Rights and the Special Characteristics of the School Environment

Since the Tinker decision, the Supreme Court has maintained that student First Amendment rights are modified by the “special characteristics of the school environment.” The nature of these characteristics, however, has not been adequately investigated. The author proposes seven characteristics of schools that are relevant to speech rights: (a) the age of students, (b) attendance requirements, (c) multiple school constituencies, (d) heightened safety considerations, (e) the need for public accountability, (f) the school-associated nature of much student speech, and (g) the need to promote educational goals. A preliminary examination of these characteristics leads to a complex picture of student rights. In the face of such complexity, the author proposes that if speech rights are to be limited because of educational concerns, they must be limited in a way that is itself educational.
Catalytic Decomposition of Ethylene on Nickel

THE mechanism of the hydrogenation of ethylene on nickel has been studied intensively for at least thirty years; but there is still little agreement as to the exact nature of the intermediates present on the metal surface during the reaction. On the other hand, examination of the chemisorption and dissociation of ethylene on nickel in the absence of gaseous hydrogen has been slight and mostly confined to ambient temperatures1,2. This is surprising as the products and mechanism of ethylene dissociation can play an important part in hydrogenation, exchange and other reactions.
Evaluating whether changes in utilization of hospital outpatient services contributed to lower Medicare readmission rate.

Objective Descriptive analysis comparing changes in hospital inpatient readmissions to emergency department visits and observation stays that occurred within 30 days of an inpatient stay.
Co-localisation of NADPH diaphorase activity and GABA immunoreactivity in local circuit neurones in the medial prefrontal cortex (mPFC) of the rat

This study provides evidence that neurones in the medial prefrontal cortex of the rat (mPFC areas 24b, 25, and 32) containing strong NADPH diaphorase reactivity also contain GABA immunoreactivity. Also demonstrated is the co-localisation of NADPH diaphorase activity with immunoreactivity for the neuronal isoform of nitric oxide synthase (nNOS) in mPFC neurones. Qualitative and quantitative analyses in the light and electron microscopes indicate that strongly NADPH diaphorase reactive cells are a subpopulation of GABAergic local circuit neurones and constitute a very small proportion (0.6-1.1%) of neurones in rat mPFC. These results suggest that NADPH diaphorase reactive cells in rat mPFC can influence neural activity via GABA-mediated and NO-mediated mechanisms.
Ab initio cluster-model study of the electronic ground-state and photoemission properties of NiN 2 and NiCO: Models for chemisorption

The ground state of the linear ${\mathrm{NiN}}_{2}$ cluster is found, from generalized valence-bond configuration-interaction calculations, to be a $^{1}\mathrm{\ensuremath{\Sigma}}^{+}$ state with a short Ni--N distance of 1.64 A\r{} and a Ni--${\mathrm{N}}_{2}$ dissociation energy of 0.8 eV. In this $^{1}\mathrm{\ensuremath{\Sigma}}^{+}$ state near the calculated equilibrium internuclear distance, the electronic wave function may be characterized as arising from a significant admixture of the Ni 3${d}^{10}$ configuration, and the bonding of the ${\mathrm{N}}_{2}$ molecule to the Ni atom may be characterized as ${\mathrm{N}}_{2}$ \ensuremath{\sigma} donation and Ni 3d\ensuremath{\pi} backward donation. Low-lying excited states ${(\mathrm{}}^{3}$${\ensuremath{\Sigma}}^{+}$, $^{3}\mathrm{\ensuremath{\Delta}}$, and $^{3})$ arising from the Ni 3${d}^{9}$4${s}^{1}$ configuration are also studied. Mulliken population analyses, dipole moments, and vibrational and photoemission properties are calculated. Parallel calculations are also performed for the linear NiCO molecule. The $^{1}\mathrm{\ensuremath{\Sigma}}^{+}$ states of both ${\mathrm{NiN}}_{2}$ and NiCO are good models for the chemisorption of ${\mathrm{N}}_{2}$ and CO on a Ni surface, with regard to the downward shift of the molecular stretching frequency in the interacting systems, the photoemission satellite structure, and the orientation of the dipole moments (with a net electron transfer from Ni to ${\mathrm{N}}_{2}$ or CO).
Locomotor stimulation produced by 3,4-methylenedioxymethamphetamine (MDMA) is correlated with dialysate levels of serotonin and dopamine in rat brain

(+/-)-3,4-Methylenedioxymethamphetamine (MDMA, or Ecstasy) is an illicit drug that evokes transporter-mediated release of monoamines, including serotonin (5-HT) and dopamine (DA). Here we monitored the effects of MDMA on neurochemistry and motor activity in rats, as a means to evaluate relationships between 5-HT, DA, and behavior. Male rats undergoing in vivo microdialysis were housed in chambers equipped with photobeams for measurement of ambulation (i.e., forward locomotion) and stereotypy (i.e., head weaving and forepaw treading). Microdialysis probes were placed into the n. accumbens, striatum or prefrontal cortex in separate groups of rats. Dialysate samples were assayed for 5-HT and DA by microbore HPLC-ECD. Rats received two i.v. injections of MDMA, 1 mg/kg followed by 3 mg/kg 60 min later; neurochemical and locomotor parameters were measured concurrently. MDMA produced dose-related elevations in extracellular 5-HT and DA in all regions, with the magnitude of 5-HT release always exceeding that of DA release. MDMA-induced ambulation was positively correlated with dialysate DA levels in all regions (P<0.05-0.0001) and with dialysate 5-HT in striatum and cortex (P<0.001-0.0001). Stereotypy was strongly correlated with dialysate 5-HT in all areas (P<0.001-0.0001) and with dialysate DA in accumbens and striatum (P<0.001-0.0001). These data support previous work and suggest the complex spectrum of behaviors produced by MDMA involves 5-HT and DA in a region- and modality-specific manner.
Quantitation of multiple gene expression by in situ hybridization autoradiography: accurate normalization using Bayes classifier.

In the method of in situ hybridization autoradiography, quantitative comparisons among multiple mRNA signals have proven difficult for many reasons, attributable both to technical factors (e.g. different probe specific activities) as well as to large differences in the patterns and levels of expression of different genes in pathologic states. Here we report a standardized normalization procedure for in situ hybridization autoradiography, employing a Bayes classifier, which permits the comparison of multiple mRNA probes. Autoradiograms of different probes in individual animals are first digitized and converted to units of radioactivity. Next, pixel-distribution histograms are generated for each mRNA signal. The Bayes classifier is then used to establish an optimal threshold to distinguish activated and non-activated pixels. This threshold also defines the minimal level of mRNA expression. The maximal mRNA signal is defined as the mean + 3 SD of the activated pixel distribution. We then use a linear transformation to convert each pixel from absolute activity to percentage of maximal mRNA signal for that particular probe. The normalized autoradiographic images can then be averaged to represent group trends and can be compared by standard statistical methods. We illustrate this normalization procedure using in situ hybridization autoradiography for three genes (GADD45, HSP70 and MAP2) expressed in the brains of rats studied at various recirculation times following transient (2 h) middle cerebral artery occlusion. The Bayes classifier is reviewed and its analytical application is presented. Step-by-step examples of intermediate steps are presented, construction of averaged data sets, and pixel-based statistical comparisons among expressed genes.
Evaluating associativity in CPU caches

The authors present new and efficient algorithms for simulating alternative direct-mapped and set-associative caches and use them to quantify the effect of limited associativity on the cache miss ratio. They introduce an algorithm, forest simulation, for simulating alternative direct-mapped caches and generalize one, which they call all-associativity simulation, for simulating alternative direct-mapped, set-associative, and fully-associative caches. The authors find that although all-associativity simulation is theoretically less efficient than forest simulation or stack simulation (a commonly used simulation algorithm), in practice it is not much slower and allows the simulation of many more caches with a single pass through an address trace. The authors also provide data and insight into how varying associatively affects the miss ratio. >
Update on molecular findings, management and outcome in low-grade gliomas

Low-grade infiltrating gliomas in adults include diffuse astrocytoma, oligoastrocytoma and oligodendroglioma. The current gold standard diagnosis of these tumors relies on histological classification; however, emerging molecular abnormalities discovered in these tumors are playing an increasingly prominent part in the process of tumor diagnosis and, consequently, patient management. The frequency and clinical importance of tumor protein p53 (TP53) abnormalities, deletions involving chromosomes 1p and 19q, O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, abnormalities in the PTEN tumor suppressor gene and the BRAF oncogene, and isocitrate dehydrogenase (IDH) mutations have become better defined. Molecular markers have not, historically, had an important role in determining the course of treatment for patients with low-grade gliomas, but ongoing phase III clinical trials incorporate 1p deletion or 1p19q codeletion status-and future trials plan to incorporate MGMT promoter methylation status-as stratification factors. Future trials will need to incorporate IDH mutational status in addition to these factors. Ultimately, molecular marker assessment will, hopefully, improve the accuracy of tumor diagnosis and enhance the effectiveness of treatment to achieve improved patient outcomes.
A fast model of a multiple-pinhole SPECT imaging system

The Center for Gamma-Ray Imaging is developing a number of small-animal SPECT imaging systems. These systems consist of multiple stationary detectors, each of which has its own multiple-pinhole collimator. The location of the pinhole plates (i.e., magnification), the number of pinholes within each plate, as well the pinhole locations are all adjustable. The performance of the Bayesian ideal observer sets the upper limit on task performance and can be used to optimize imaging hardware, such as pinhole configurations. Markov-chain Monte Carlo techniques have been developed to compute the ideal observer but require complete knowledge of the statistics of both the imaging system (such as the noise) and the class of random objects being imaged, in addition to an accurate forward model connecting the object to the image. Ideal observer computations using Monte Carlo techniques are burdensome because the forward model must be simulated millions of times for each imaging system. We present an efficient technique for computing the Bayesian ideal observer for multiple-pinhole, small-animal SPECT systems that accounts for both the finite-size of the pinholes and the stochastic nature of the objects being imaged. This technique relies on an efficient, radiometrically correct forward model that maps an object to an image in less than 20 milliseconds. An analysis of the error of the forward model, as well as the results of a ROC study using the ideal observer test statistic is presented.
A flame emission technique for obtaining structural information from organic molecules

Abstract The use of an entrained air-hydrogen flame to obtain structural information of amines and alcohols was studied. Differences in emission intensities of CH, C2, and CN species indicate the possibility of qualitative analysis of organic compounds. A linear relationship was found to exist for members of different homologous series of amines and alcohols, when the intensity of CH emission was plotted vs. intensity of C2 or CN emission.
The maintenance assistant: work in progress

Abstract The Maintenance Assistant project at the Florida/Purdue Software Engineering Research Center seeks to develop methodologies and tools to aid in the complex tasks associated with making changes to software systems. Three broad approaches are currently being explored: dependency analysis involves capturing the dependencies between different entities in a software system and the development of tools to present and analyze these dependencies. Reverse engineering involves the identification or “recovery” of program requirements and/or design specifications that can aid in understanding and modifying it. Program change analysis involves methods for analyzing differences between two versions of a program in order to understand a change that has been made and detect possible maintenance-induced errors. A strength of the project has been the very close relationship with the industrial affiliates of the Software Engineering Research Center. It is hoped that these organizations will be able to apply the methodologies currently being explored in their own software projects and in tools to be used by their clients.
Does delayed perception of the onset of lactation shorten breastfeeding duration

This longitudinal study evaluated the impact of the timing of maternal perception of the onset of lactation on breastfeeding duration. Breastfeeding mothers who delivered a full-term infant were interviewed daily from day 1 postpartum until the onset of lactation. Women were recontacted to determine the duration of any breastfeeding at 6.7 months postpartum, and if necessary, at 16.2 months postpartum. Cox survival multivariate analyses indicated that among women planning to breastfeed for at least 6 months, those with onset of lactation < 72 hours postpartum were likely to breastfeed longer than their counterparts with a delayed onset of lactation. Median breastfeeding durations were 11.7 months and 3.4 months, respectively (p < 0.00001). Among women who intended to breastfeed for less than 6 months, the timing of the onset of lactation did not influence breastfeeding duration. All analyses controlled for body build, delivery method, employment status, education, parity, and maternal age. These findings suggest that a delayed onset of lactation is likely to be associated with a shorter breastfeeding duration. This relationship, however, was modified by the mother's intended breastfeeding duration.
Calcium-induced fusion of fusogenic wild carrot protoplasts

Rather than selecting for a chemical fusogen one can select for a fusogenic plant membrane (i.e., one that will fuse readily). Wild carrot suspension culture cells can be grown under conditions which cause the released protoplasts to have a high potential to fuse. Protoplast fusion is enhanced by calcium and inhibited by EGTA. When 10mM calcium (pH6.0) is added, fusion percentages of 60% are common. The mild fusion treatment appears to have no effect on callus regeneration and differentiation.