cssi/SciSciGPT-SciSciNet huggingface dataset:
Case 46: A Longstanding Tracheostomy

A 3-year-old child has been in the ICU for 1 month. She has a tracheostomy and is breathing spontaneously. The tracheostomy is kept in place by a tie around her neck. She was involved in a major trauma and sustained a head injury, hemothorax, and lacerated liver. She is now scheduled for a laparotomy for the exclusion of possible sepsis in the abdomen.
The Effects of Paired versus Sequential Stimulation on Speech Recognition Outcomes of Adult Cochlear Implant Recipients.

PURPOSE Cochlear implant (CI) sound-processing strategies are important to the overall success of a CI recipient. This study aimed to determine the effects of 2 Advanced Bionics (AB) CI-processing strategies, Optima-S and Optima-P, on speech recognition outcomes in adult CI users. METHODS A retrospective chart review was completed at a tertiary academic medical center. Seventeen post-lingually deafened adult CI users (median age = 58.6 years; age range: 23.5-78.9 years) with long-term use of a paired sound-processing strategy (Optima-P) were reprogrammed with a sequential strategy (Optima-S). Demographic data and speech recognition scores with pre- and post-intervention analyses were collected and compared with respect to the 95% confidence interval for common CI word and sentence recognition tests. RESULTS Using Optima-S sound-processing strategy, all patients (100%) performed equivalent or better on word and sentence testing than with Optima-P. More specifically, 17.6, 41.2, and 58.8% of the patients performed above the 95% confidence interval for speech recognition conditions of monosyllabic words, sentences in quiet, and sentences in noise, respectively. All patients (100%) selected Optima-S as their preferred strategy for future CI use. CONCLUSION Speech recognition performance with Optima-S processing strategy was stable or improved compared to results with Optima-P in all tested conditions, and subjective preference of Optima-S was selected by all patients. Given these results, CI clinicians should consider programming AB CI users with Optima-S sound-processing strategy to optimize overall speech recognition performance.
Automatic Solution of the System of Equations of the Equivalent Radius of the Distribution Ellipses of Dielectric Materials for the Recognition of Gold Nanoparticles

The presented research is aimed at developing scientific and technical bases for conducting mathematical modeling of nanostructured physical objects of small dimensions. The sensitivity of identification of biologically active nanoparticles of metallic gold to cancer cells is considered based on the results of differentiation of the equivalent radii of intersection of ellipses of the distribution of statistical values of the peaks of Raman spectra together with the XY equations. A method is proposed for the automatic solution of a multidimensional system of nonlinear differential equations for the intersection of ellipsoids of Raman spectrograms of dielectric materials with and without gold nanoparticles. When solving the problem of increasing the accuracy and speed of recognition of gold nanoparticles on the surface of the fibers, the polarization of laser radiation along and across the fibers was taken into account. When solving the system using nonlinear quadratic and XY differential equations of the equivalent radii of the ellipses of the distribution, a high accuracy of R0 and R1 is obtained up to 10-15.
Axiology-Based Valuation Modeling for Human-Centered Decision Making in Building Planning and Design

AbstractUnderstanding and assessing the value of building systems to stakeholders and the impacts of decision making on this value has become a national imperative. However, there is still a lack o...
An overview of aerospace gas turbine technology of relevance to the development of the automotive gas turbine engine

Technology areas related to gas turbine propulsion systems with potential for application to the automotive gas turbine engine are discussed. Areas included are: system steady-state and transient performance prediction techniques, compressor and turbine design and performance prediction programs and effects of geometry, combustor technology and advanced concepts, and ceramic coatings and materials technology.
Inverse Modeling of Coastal Tides

Abstract : The principal goal of this project is to develop efficient, relocatable, tidal data assimilation schemes that make use of all available information, including data (e.g., altimetry, current moorings, coastal radar) and dynamics to constrain barotropic and internal tides (especially tidal currents) in coastal areas and shallow seas. A secondary objective is to develop a better understanding of how uncertainties and approximations in the hydrodynamic equations limit the degree to which particular data types (e.g., spatially dense estimates of tidal elevations from altimetry, or surface currents from coastal radar) can constrain tidal currents and elevations in shallow water environments. I have three objectives in the current project period. The first is to adapt the computationally intensive methods developed by Egbert, Bennett, and Foreman [1994] for inverse tidal modeling at the global scale, into a relocatable inversion package that may be routinely applied to smaller scale (regional/coastal) barotropic tidal modeling. The second objective is to apply these methods to study tidal currents off the west coast of North America, with particular emphasis on the Oregon coastal zone where extensive current meter and coastal radar data are available. A third objective is to begin development of methods for tidal inversion in a three-dimensional stratified ocean. These methods will be tested on coastal radar and current meter data from the Oregon coast.
Tubal ligation as part of family planning in India

Abstract In rural South India, a survey was done to determine the attitudes toward salpingectomy as a means of birth control. Selection of 200 women was made from hospital records; 146 of the selected women were interviewed. The women under study were up to 9 years post tubal ligation. Educational status was noted to be higher in these patients and their husbands than in the general population. Physical complaints in 27 per cent of the women did not change the favorable attitudes of the women. There was favorable discussion of the operation with neighbors and friends by 97 per cent of the women and 98 per cent would urge others to undergo the operation. Note is made of other studies showing less favorable attitudes after vasectomy and after use of IUD. A plea is made, therefore, for inclusion of salpingectomy in programs of birth control.
Frequency and Circadian Timing of Eating May Influence Biomarkers of Inflammation and Insulin Resistance Associated with Breast Cancer Risk

Emerging evidence suggests that there is interplay between the frequency and circadian timing of eating and metabolic health. We examined the associations of eating frequency and timing with metabolic and inflammatory biomarkers putatively associated with breast cancer risk in women participating in the National Health and Nutrition Examination 2009-2010 Survey. Eating frequency and timing variables were calculated from 24-hour food records and included (1) proportion of calories consumed in the evening (5 pm-midnight), (2) number of eating episodes per day, and (3) nighttime fasting duration. Linear regression models examined each eating frequency and timing exposure variable with C-reactive protein (CRP) concentrations and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Each 10 percent increase in the proportion of calories consumed in the evening was associated with a 3 percent increase in CRP. Conversely, eating one additional meal or snack per day was associated with an 8 percent reduction in CRP. There was a significant interaction between proportion of calories consumed in the evening and fasting duration with CRP (p = 0.02). A longer nighttime fasting duration was associated with an 8 percent lower CRP only among women who ate less than 30% of their total daily calories in the evening (p = 0.01). None of the eating frequency and timing variables were significantly associated with HOMA-IR. These findings suggest that eating more frequently, reducing evening energy intake, and fasting for longer nightly intervals may lower systemic inflammation and subsequently reduce breast cancer risk. Randomized trials are needed to validate these associations.
Human papillomavirus infection in human immunodeficiency virus-seropositive women.

Objective: To compare the prevalence of human papillomavirus (HPV) infections in women who are seropositive and seronegative for human immunodeficiency virus (HIV), and to determine if associations between HPV and cervical disease are altered in HIV-seropositive women. Methods: In this cross-sectional study, 344 HIV-seropositive and 325 HIV-seronegative women underwent colpbscopy and HPV DNA testing. Results: Human immunodeficiency virus-seropositive women were more likely than HIV-seronegative women to have HPV DNA of any type detected (60 versus 36%, P P P P Conclusion: Human papillomavirus infections are more common among HIV-seropositive women at all levels of immunosuppression. However, relationships between HIV and HPV are complex and cannot be explained completely by an increased susceptibility to new HPV infections in the immunosuppressed patient.
Chirped Laser Dispersion Spectroscopy for Remote Sensing of Methane

A new near-IR chirped laser dispersion spectroscopy system operating at 1.65µm is presented. We demonstrate its application to remote sensing of methane in the atmosphere.
New FATB thioesterases from a high‐laurate Cuphea species: Functional and complementation analyses

The New World genus Cuphea is a rich source of genes encoding enzymes specialized for seed-specific synthesis of short- and medium-chain fatty acids (FA). We isolated and characterized two new acyl-acyl carrier protein (ACP) thioesterase (TE) cDNA, CcFATB1 and CcFATB2, from developing seeds of C. calophylla var. mesostemon. Cuphea calophylla is one of several species in the genus specializing in the synthesis of lauric acid (12:0). Phylogenetic clustering classified CcFATB1 and CcFATB2 as medium- and long-chain FATB TE, respectively. Gene expression analysis indicated that CcFATB1 was seed specific and CcFATB2 was ubiquitous. Overexpression of CcFATB1 in developing seeds of Arabidopsis partially redirected FA synthesis toward medium-chain FA (12:0, 14:0, and 16:0). Laurate synthesis was preferentially increased by co-expressing CcFATB1 and CwKAS A1, a medium-chain-specific ketoacyl-ACP synthase (KAS) from another 12:0-rich species, C. wrightii. Overexpression of CcFATB1 cDNA complemented the low-palmitate (16:0) but not the low-stearate (18:0) phenotype in leaves and seeds of an Arabidopsis fatb-2 mutant, whereas CcFATB2 restored both long-chain FA. The investigated Cuphea species provide a diverse source of seed-specific FATB and KAS genes for combinatorial manipulation of medium-chain FA content in oilseed plants.
Postprandial disruption of migrating myoelectric complex in dogs. Hormonal versus extrinsic nervous factors.

Our aim was to determine the mechanism whereby the jejunoileum regulates postprandial gastroduodenal motility. Five dogs were prepared with a proximal jejunal infusion catheter and with gastric manometry catheters and serosal intestinal electrodes for recording gastric and intestinal motility. After two weeks, fasted dogs were studied during jejunal infusion of either isosmolar NaCl (154 mM) or isosmolar mixed nutrient solution (50% Meritene) on four separate days each. After completion of these baseline studies, the dogs underwent a model of autotransplantation of the entire jejunoileum (extrinsic denervation, disruption of intrinsic neural continuity with proximal duodenum). Two weeks later, identical studies as before were repeated with the now “autotransplanted” jejunoileum. Before transplantation, infusion of NaCl did not interrupt the characteristic interdigestive migrating motor complex either in the gastroduodenum or in the jejunoileum. However, infusion of nutrients interrupted the migrating motor complex both in the gastroduodenum and jejunoileum for the duration of the infusion (5 hr). After autotransplantation of the jejunoileum, the migrating motor complex continued to occur in the gastroduodenum and in the jejunoileum during infusion of NaCl, but the migrating motor complex cycled independently in each region without any temporal coordination. Jejunal infusion of nutrients interrupted the MMC in both regions for the duration of infusion (5 hr). Because inhibition of the gastroduodenal and jejunoileal migrating motor complex continued to occur during infusion of nutrients into the transplanted jejunum, we concluded that jejunoileal regulation of postprandial inhibition of interdigestive motility in the stomach and duodenum is mediated by hormonal factors and does not require intrinsic neural continuity.
Resistive Switching in Bulk Silver Nanowire–Polystyrene Composites

Traditionally, bulk nanocomposites of electrically conducting particles and insulating polymers have been categorized as either insulating or conducting when the nanoparticle concentration is below or above the percolation threshold, respectively. Meanwhile, thin-film polymer nanocomposites can exhibit resistive switching behavior appropriate for digital memory applications. Here, we present the first report of reversible resistive switching in bulk, glassy polymer nanocomposites. At compositions close to the electrical percolation threshold measured at low voltage, silver nanowire-polystyrene nanocomposites demonstrate reversible resistive switching with increasing voltage at room temperature. Nanocomposites with compositions outside of this range exhibit either irreversible switching, or no switching at all. We propose that resistive switching in these materials is the result of the field-induced formation of silver filaments that bridge adjacent nanowire clusters, extending the percolation network and decreasing the sample’s bulk resistivity. These findings break from the usual dichotomy of insulating or conducting properties in polymer nanocomposites and could inspire new devices that capitalize on this responsive behavior in these versatile materials.
First-principles study of phase stability of BN under pressure

Abstract The structural and energetic properties of three phases of boron nitride, the graphite-like hexagonal phase ( h -BN), the cubic phase ( c -BN), and the wurtzite phase ( w -BN) have been studied using first-principles pseudopotential calculations. Calculated cohesive energies reveal that c -BN is lower in energy than h -BN by 0.08 eV/atom, in good agreement with the experimental value of 0.17 eV/atom. w -BN is predicted to become a denser phase than c -BN at 16 GPa, in good agreement with experimental observation of a transition from h -BN to w -BN at P >12.5 GPa. The calculated energetic results together with empirical rules on crystal growth provide a good understanding for phase stability and transformation of boron nitride under pressure.
Dynamics of Pool Boiling on Plain and Nanotube Coated Silicon Surfaces

Saturated pool boiling experiments are conducted over silicon substrates with and without Multi-walled Carbon Nanotubes (MWCNT) with PF-5060 as the test fluid. Micro-fabricated thin film thermocouples located on the substrate acquire surface temperature fluctuation data at 1 kHz frequency. The high frequency surface temperature data is analyzed for the presence of chaotic dynamics. The shareware code, TISEAN© is used in analysis of the temperature time-series. Results show the presence of low-dimensional deterministic chaos, near Critical Heat Flux (CHF) and in some parts of the Fully Developed Nucleate Boiling (FDNB) regime. Some evidence of chaotic dynamics is also obtained for the film boiling regimes. Singular value decomposition is employed to generate pseudo-phase plots of the attractor. In contrast to previous studies involving multiple nucleation sites, the pseudo-phase plots show the presence of multi-fractal structure at high heat fluxes and in the film boiling regime. An estimate of invariant quantities such as correlation dimensions and Lyapunov exponents reveals the change in attractor geometry with heat flux levels. No significant impact of surface texturing is visible in terms of the invariant quantities.Copyright © 2010 by ASME
Agrin-Induced Postsynaptic-like Apparatus in Skeletal Muscle Fibersin Vivo

We find that when extrajunctional regions of denervated soleus muscles in adult rats are transfected with cDNA encoding rat agrin isoform Y4Z8, which is normally secreted by motor neurons at adult neuromuscular junctions, the myofibers express and secrete the neural agrin. Muscle fibers in the vicinity of transfection form at their surface specialized areas having extracellular, plasma membrane, and cytoplasmic protein aggregates, narrow and deep plasma membrane infoldings, and an accumulation of myonuclei, all of which are characteristic of the postsynaptic apparatus at neuromuscular junctions. We conclude that at ectopic neuromuscular junctions that form in the extrajunctional region of denervated adult soleus muscles after implantation of a foreign nerve, a single neural-derived factor, agrin, is sufficient not only to cause protein aggregation in the early stages of postsynaptic apparatus formation, as predicted by the agrin hypothesis, but also to bring about changes in conformation of the muscle fiber surface and distribution of organelles which appear as the apparatus reaches maturity.
Evaluation of the Jebson hand function test for use in patients with rheumatoid arthritis

Purpose. We have evaluated the Jebson hand function (JHF) test for use in patients with rheumatoid arthritis (RA). Methods. The JHF test was administered to 25 patients with RA. Results were compared to normative data and related to ability to perform activities of daily living (ADL), pain, and deformity. Results. The JHF test detects differences between patients with RA and normals; all components except for writing show correlations with ADL and deformity. There were no significant correlations with pain. Conclusions. The JHF test is a useful adjunct to evaluation of the hand in RA.
Atomic discourse in The Feynman Lectures on Physics

We examine the compromises that are actually made in modern scientific discourse concerning atoms. We conclude that even the ideals of clarity and consistency can be legitimately compromised in order to obtain other advantages.
CD results for 6 inch 250 mil PBS photoblanks for a 0.50 micron generation photomask process

This paper discusses work done at Intel to meet CD specifications for a 0.50 micron generation photomask process using 6' 250 mil photoblanks coated with PBS resist. Initial CD uniformity results indicated that the develop tool was the main source of non-uniformity. To reduce the contribution of the develop tool, two strategies were pursued simultaneously to ensure that the within-plate linewidth uniformity (3 sigma) of the etched CD's would be 50 nm. The first strategy was to improve the capability of the current developer and to determine if any write parameters could be modified to allow for more process latitude. The second strategy was to evaluate new developers and identify a possible replacement. Both of these strategies will be presented with accompanying results for CD uniformity of the developed and etched CD structures.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Dibromotrithiocarbonate Iniferter for Concurrent ATRP and RAFT Polymerization. Effect of Monomer, Catalyst, and Chain Transfer Agent Structure on the Polymerization Mechanism

An iniferter comprising a trithiocarbonate (TTC) moiety and two bromine chain ends was prepared and used to successfully conduct, independently or concurrently, atom transfer radical polymerization...
Need for escape protein by grazing cattle

Abstract Grazing cattle require rumen degradable protein to meet the needs of the microbial population and rumen undegradable protein to meet the productive needs of the animal. The need for rumen degradable protein is about 130 g kg−1 of digestible organic matter. However, when low-quality forage is consumed, rate of passage is reduced, microbial growth rate is reduced and conversion efficiency of microbial growth is reduced. This probably lowers the rumen degradable protein requirement. Escape protein is necessary to meet cattle requirements for growth or lactation. Microbial protein is usually adequate for animals at or near maintenance. The protein in both cool-season and warm-season grasses is highly degraded. Therefore, growing cattle and lactating cows responded to supplemental escape protein. Knowledge of the rumen degradable and undegradable protein contents of grazed forages is essential to more precisely predict animal performance and the animal response to protein supplements.
Single crystal neutron diffraction analysis of the cation distribution in the high-temperature phases α-Cu2−xS, α-Cu2−xSe, and α-Ag2Se

Abstract The distribution and thermal vibration of the mobile cations have been studied for α -Cu 2− x S (200°C), α -Cu 2− x Se (160, 210, and 360°C), and α -Ag 2 Se (135, 150, 200, and 300°C). Both α -Cu 2− x S and α -Cu 2− x Se, space group Fm3m, have an fcc anion array within which anharmonically-vibrating Cu atoms are displaced from the centers of the tetrahedra towards the vacant octahedral interstices. α -Ag 2 Se, space group Im3m, has Se in bcc packing and displays a cation distribution which is delocalized in channels along 〈100〉 similar to β-Ag 2 S. Local maxima in the Ag density occur in pairs about the center of the tetrahedral interstice.
The multivocality of a national myth: Memory and counter‐memories of Masada

(1995). The multivocality of a national myth: Memory and counter‐memories of Masada. Israel Affairs: Vol. 1, The Shaping of Israeli Identity: Myth, Memory and Trauma, pp. 110-128.
Prävention und Behandlung der Schambeinentzündung – ein unterschätztes Problem?

Zusammenfassung Die Schambeinentzundung findet sich bei diversen Sportarten als schmerzhaftes, oft chronisches Problem. Dabei ist das Krankheitsbild der Schambeinentzundung als Oberbegriff von diversen Pathologien am und um die Schambeingegend zu verstehen. Eine prazise Diagnostik ist wegen der zum Teil vorliegenden Komplexitat mit mehreren involvierten Strukturen und Pathologien nicht immer einfach. Kenntnisse der sportartspezifischen Bewegungsmuster mit den jeweiligen Belastungen bestimmen die praventiven Masnahmen und die Therapie. Gezielte praventive Masnahmen wie Kraftigung, Becken-Rumpfstabilisierung und Koordinationstraining zeigen oft eine positive Auswirkung. Die Behandlung ist primar konservativ, bei Chronifizierung konnen operative Interventionen notwendig sein. Speziell beim Spitzensportler.
Leukocyte subtypes in electroejaculates of spinal cord injured men

Abstract Trabulsi EJ, Shupp-Byrne D, Sedor J, Hirsch IH. Leukocytes subtypes in electroejaculates of spinal cord injured men. Arch Phys Med Rehabil 2002;83:31-4. Objectives: To determine the level of leukocytospermia and seminal leukocyte subtypes in men with spinal cord injury (SCI) and to compare the findings with those of fertile, able-bodied controls. Design: Prospective, controlled clinical trial. Setting: University infertility practice. Participants: Thirteen able-bodied fertile men age matched to 17 men with SCI seeking reproductive rehabilitation. Interventions: Vibratory stimulation and antegrade electroejaculation for SCI group; manual ejaculation for controls. Main Outcome Measures: Immunoperoxidase technique on a panel of antileukocyte monoclonal antibodies to obtain the leukocyte subpopulations: B cells, T cells, neutrophils, and macrophages. Immunohistochemical staining and scoring to obtain the mean number of leukocytes and spermatozoa per high power field. The ratios of leukocyte to sperm and leukocyte subtype to sperm were tabulated. Results: Total white blood cells, neutrophils, and macrophages in the SCI population were significantly higher than those in the ejaculates of controls. Although not significantly elevated, all the other evaluated subsets were higher in the SCI group then in the controls. Conclusions: Leukocytospermia appears to be a pervasive abnormality in the semen recovered from men with SCI. The SCI group had significant elevations of total seminal leukocytes after electroejaculation. Compared with controls, men with SCI had significantly more seminal neutrophils and macrophages. Asthenospermia, universally observed in men with SCI, may be attributable, among other causes, to leukocytospermia. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
A supportive clinic: Who comes, how often, and for what?

Abstract A description of the present treatment program in a supportive, aftercare psychiatric clinic is reported and the utilization in terms of kept appointments reviewed. In comparison with a previously reported group of TAC patients, the 346 patients in our study had a higher percentage of young, unemployed blacks referred from inpatient facilities, had thought or major affective disorders, and received antipsychotic medication. There was no statistically significant difference in the mean number of kept appointments according to diagnostic category. This was probably due to the selection of patients for the clinic who are chronically ill, socioeconomically deprived and have limited interpersonal, communication, and coping skills. Supportive group therapy during the waiting room period and activities therapy sessions were effective in facilitating patient-staff interaction and in supplementing the brief supportive individual psychotherapy.
Binding of nitrogen-containing bisphosphonates (N-BPs) to the Trypanosoma cruzi farnesyl diphosphate synthase homodimer.

Bisphosphonates (BPs) are a class of compounds that have been used extensively in the treatment of osteoporosis and malignancy-related hypercalcemia. Some of these compounds act through inhibition of farnesyl diphosphate synthase (FPPS), a key enzyme in the synthesis of isoprenoids. Recently, nitrogen-containing bisphosphonates (N-BPs) used in bone resorption therapy have been shown to be active against Trypanosoma cruzi, the parasite that causes American trypanosomiasis (Chagas disease), suggesting that they may be used as anti-trypanosomal agents. The crystal structures of TcFPPS in complex with substrate (isopentenyl diphosphate, IPP) and five N-BP inhibitors show that the C-1 hydroxyl and the nitrogen-containing groups of the inhibitors alter the binding of IPP and the conformation of two TcFPPS residues, Tyr94 and Gln167. Isothermal titration calorimetry experiments suggest that binding of the first N-BPs to the homodimeric TcFPPS changes the binding properties of the second site. This mechanism of binding of N-BPs to TcFPPS is different to that reported for the binding of the same compounds to human FPPS.
Effects of fluorine and chlorine on the gate oxide integrity of W/TiN/SiO2/Si metal–oxide–semiconductor structure

Abstract We investigate the effects of fluorine (F) and chorine (Cl) on the gate oxide integrity of W/TiN/SiO2 (3 nm)/Si metal–oxide–semiconductor (MOS) structure as a function of W deposition method and post-metal anneal (PMA) process. TiN films were prepared by chemical vapor deposition (CVD) using TiCl4 and NH3, while tungsten (W) electrodes were prepared by CVD using a WF6 precursor and by physical vapor deposition (PVD) using a W target. The amount of fluorine ([F]) prepared by CVD-W was two orders of magnitude higher than that prepared by PVD-W. The interface trap density (Dit) of MOS capacitor was lower with CVD-W than the one with PVD-W by a factor of two after PMA of 950 °C, resulting in the Dit in the mid-1010/eV cm−2 range. The higher Dit, fixed charges, and oxide trap charges were observed with PVD-W deposition on top of 30 nm-thick CVD-TiN, strongly suggesting damages at the SiO2/Si interface and SiO2 even after the rapid thermal anneal at 950 °C and following forming gas anneal. However, a noticeable degradation of gate oxide quality was observed with CVD-W by means of smaller breakdown field, charge to breakdown, and shorter lifetime. The reliability degradation was partially attributed to the Cl from the TiCl4 source, while more severe deterioration was assigned to the F from WF6 source after the PMA at 650 °C and above.
Crystallographic aspects of dislocation emission from a crack tip in an fcc metal

Abstract Dislocations are observed to emit from crack tips in atomic simulations of fcc metals as Shockley partials. The crystallographic anisotropy associated with emission as partials relative to perfect dislocations is discussed. The stress intensity needed to emit a dislocation is derived in terms of both the anisotropic and the isotropic versions of a Peierls-like criterion posed by Rice et al. for dislocation emission and which invokes a critical emission force ΦIc. By systematically changing the orientation of the crystal relative to the crack coordinates, the behaviours of atomic models of embedded-atom method nickel are observed to change from emission to crack extension in a way that is quantitatively consistent with the combined predictions of the Rice et al. and Griffith criteria using a constant emission force ΦIc and the relevant surface enthalpies. Furthermore, using the value of ΦIc that best represents the single-crystal results, the predictions are also found to agree favourably with the...
A Becke3LYP/6-31G* Study of the Cope Rearrangements of Substituted 1,5-Hexadienes Provides Computational Evidence for a Chameleonic Transition State

B3LYP/6-31G* calculations have been performed on the chair Cope rearrangements of a wide variety of 1,5-hexadienes, substituted with cyano or with vinyl groups. In agreement with experimental data from the study of phenyl substituent effects, cyano and vinyl groups at C(2) and C(5) are found to provide cooperative lowering of the activation enthalpy, as are substituents at C(1), C(3), C(4), and C(6). In contrast, the stabilization of the transition structure by substituents at C(2) and C(4) or at C(1), C(3), and C(5) is predicted to be competitive, rather than cooperative. These findings are consistent with what Doering has termed a chameleonic transition state for the Cope rearrangement, one in which the relative importance of the cyclohexane-1,4-diyl and bis-allyl radical resonance contributors can be altered by substituents, depending on the carbons to which the substituents are attached. The computed bond lengths in the transition structures and the calculated and experimentally observed kinetic isoto...
Historicizing Chinese Science and Technology

In The Wealth and Poverty of Nations: Why Some Are So Rich and Some So Poor published in 1998, David S. Landes argued that culture was what made all the difference in world economic history. It was...
Using narrative in the study of school administration

The use of narrative, which has informed the study of teaching, has only been applied in a limited manner to studies focusing on school administrators. This study of the journal‐keeping practices of school principals provides a glimpse into the use of narrative as a possible methodological strategy for understanding the stories of administrators. It begins to define how personal values, political pressures, and organizational concerns are translated into actions that are intended to solve day‐to‐day school problems. It illuminates tacit knowledge of how administrators sort through their often chaotic lives. Implications of the study for future research are examined.
Immobilization of glucoamylase from Aspergillus niger on poly(ethylenimine)-coated non-porous glass beads

Abstract Glucoamylase (1,4-α- d -glucan glucohydrolase, EC 3.2.1.3) from A. niger was immobilized on cationic nonporous glass beads (13–44 μm) by electrostatic adsorption followed by rosslinking with glutaraldehyde. Over 80% of the enzyme's total soluble activity was expressed upon immobilization. d -Glucose production from maltodextrins was virtually complete, suggesting that the lack of pores can eliminate the problem of product reversion. Immobilized glucoamylase showed decreased stability upon heating, compared with the soluble enzyme .
Fractional destraction of coal-derived materials

Abstract The use of supercritical fluids to fractionate coal-derived distillate and residuum in a manner analogous to conventional fractional distillation is reported. Fractionation based upon volatility is observed when a fluid density gradient is established in the unit to promote reflux.
Song recognition by territorial male buntings (Passerin A)

Summary The songs of several closely related species of buntings were played to territorial, male painted buntings and indigo buntings, and the measure of their territorial responsiveness to songs and to dummies was taken as a measure of the birds' ability to distinguish their own song from those of other species. The painted buntings showed a high degree of responsiveness to songs and a dummy of their own species, but little or none to songs and dummies of indigo buntings, lazuli buntings, varied buntings, and orange-breasted buntings. The indigo buntings responded vigorously to songs of their own species, mildly to some lazuli bunting songs, but not to others, and not at all to painted bunting song. The spacing of the song figures, or the ‘tempo’ of the song, and the frequency range of the figures seem to be the most critical factors involved in song recognition. The actual shape of the song figures seems to be of relatively little importance to species recognition in the indigo bunting.
Bombardment-induced compositional change with alloys, oxides, oxysalts and halides III. The role of chemical driving forces☆

Abstract Recent experiments suggest that weak chemical driving forces play a role in bombarded targets even when, for reasons of extreme energy disparity, it might be difficult to understand why this should be so. With bombardment-induced segregation the driving force, assuming the process to resemble equilibrium segregation, is 0.06–0.52 eV atom −1 . We suggest that the segregation is the result of a certain fraction of the ballistic trajectories terminating near the target surface being followed by one or more low energy, chemically guided steps. With bombardment-induced mixing the driving force, according to Cheng et al., is typically 1.3 eV atom −1 or less. We propose a very similar model to that of segregation, namely ballistic trajectories with terminal steps which are chemically guided. Finally, with bombardment-induced decomposition, as when oxides lose oxygen or sulfates lose sulfur and oxyten, there appears to be a role for what are effectively phase changes in which the system appears to tolerate an energy increase of up to 0.7–0.8 eV atom −1 but not a larger amount. The changes, which resemble those analyzed by Fecht and Johnson, are aided by a number of factors, including amorphization, point-defect accumulation, volatility, diffusional transport and segregation. We tend to avoid in all cases a thermal spike type of argument, if only because the inequality (driving force) ⪆ kT must be obeyed.
Wireless network cloud: architecture and system requirements

With the growth of the mobile communication network, from second-generation to third-generation or fourth-generation networks, technologists in the mobile industry continue to consider advanced wireless network architectures that have the potential to reduce networking costs and provide increased flexibility with respect to network features. In this paper, we propose the wireless network cloud (WNC), a wireless system architecture for a wireless access network. This system makes use of emerging cloud-computing technology and various technologies involved with wireless infrastructure, such as software radio technology and remote radio head technology. Based on open information technology architecture, the WNC provides all the necessary transmission and processing resources for a wireless access network operating in a cloud mode. Note that it is useful to separate the hardware and software for different wireless standards and various services and business models, as well as to meet the new system requirements for emerging wireless technologies, such as collaborative processing at different scales of network use. We analyze several important system challenges involving computational requirements of virtual base stations, I/O throughput, and timing networks for synchronization. Based on current information technologies, we make several suggestions with respect to future system design.
Singing voice handicap and videostrobolaryngoscopy in healthy professional singers

Summary: Objectives. This study correlates the Singing Voice Handicap Index (SVHI) scores with videostrobolaryngoscopy in healthy professional singers as a measure of self-perceived vocal health versus actual pathology seen on examination. The objectivewas to measure the strength of self-assessment among professional singers and determine if there is a benefit of combining SVHI and videostrobolaryngoscopy for routine assessment of singers without an obvious singing voice problem. Study Design. Prospective cross-sectional study. Methods. Forty-seven singers were included in the study. Singers produced spoken and sung pitches during videostrobolaryngoscopy. Examinations were blindly rated by two independent fellowship-trained laryngologists who assessed vocal fold appearance and function. The correlation between SVHI scores and total pathologic findings seen on videostrobolaryngoscopy was analyzed using linear regression and serial t tests. Results. SVHI scores (mean of 22.45/144) were as expected for healthy singers. However, although all singers selfidentified as healthy, laryngeal abnormalities were relatively common. The interrater reliability of total pathologic findings between two laryngologists was 71% (P ¼ 0.006). Linear regression found no significant correlation (P ¼ 0.9602) between SVHI scores and videostrobolaryngoscopy findings. Conclusion. Greater than expected laryngeal pathology was seen in these professional singers, who identified themselves as healthy, which possibly indicates a minimal impact on their singing voice and/or perception of vocal health. These findings demonstrate that laryngeal appearance alone does not dictate nor fully explain the sound or apparent health of a professional singer. Sustaining good vocal health is complex, and even experienced singers may not reliably assess the presence of pathology.
WAFERS AND WAFER SEALS: HISTORY, MANUFACTURE, AND CONSERVATION

Summary Wafers are thin, flat, baked adhesive discs which were used for a variety of sealing and joining functions. In use as early as 1635, wafers were largely displaced by the end of the 19th century by pre-gummed envelopes and seal papers. Recipes for wafers called for fine white flour, isinglass, glair. yeast and a colorant, typically vermillion. Other pigments such as indigo, verdigris, gamboge and red lead were also used. The ingredients were mixed into a paste, diluted with a gum solution, and baked on a metal sheet, or between the faces of a ‘wafer iron’. After cooling, the wafers were cut out of the sheets by hand with round steel punches. Wafers were produced in different sizes for use as adhesive joins or for affixing paper-covered seals on deeds, indentures or other official documents, and are often mistaken for resinous (sealing) wax seals. The use of wafers for repair of torn paper and for mounting of photographs has been observed. The brittleness of wafers can result in breakage and loss, a...
Application of the END Theory to the H + D2→ HD + D Reaction†

We investigate time-delay effects in the formation of HD products when H projectiles collide with D 2 targets with a collision energy of 1.64 eV in the center-of-mass frame using the electron-nuclear dynamics (END) approach. Trajectories having target orientations within a 60° cone measured about the D-D bond are those that lead to the production of HD. In the impact-parameter regions that correspond to the formation of HD, we note a large change in the scattering angle of the HD product within a localized narrow region as a function of impact parameter. Calculated classical and semiclassical differential reaction cross sections are presented and compared to available experimental data. Finally, a coherent-state study of the vibrational modes for the product HD is presented.
Sex expression in fern gametophytes: Some evolutionary possibilities

Abstract I suggest that, in addition to possible advantages accruing from mate availability and outcrossing, control of sex expression by neighboring fern gametophytes may be either a result of parental manipulation of sibling altruism, or possibly of female allelopathic interactions with unrelated individuals. Basic to either model are size specific differences in allocations to maleness and femaleness, for which some evidence is presented, but neither model can be tested with present information.
Data Near Here: Bringing Relevant Data Closer to Scientists

Large scientific repositories risk losing value as their holdings expand, because scientists must work harder to locate particular datasets of interest. In an effort to resolve this issue, the Data Near Here application applies information retrieval techniques to dataset search.
Simulating snowmelt processes during rain-on-snow over a semi-arid mountain basin

In the Pacific Northwest of North America, significant flooding can occur during mid-winter rain-on-snow events. Warm, wet Pacific storms caused significant floods in the Pacific Northwest in February 1996, January 1997 and January 1998. Rapid melting of the mountain snow cover substantially augmented discharge during these flood events. An energy-balance snowmelt model is used to simulate snowmelt processes during the January 1997 event over a small headwater basin within the Reynolds Creek Experimental Watershed located in the Owyhee Mountains of southwestern Idaho, U.S.A. This sub-basin is 34% forested (12% fir, 22% aspen and 66% mixed sagebrush (primarily mountain big sagebrush)). Data from paired open and forested experimental sites were used to drive the model. Model-forcing data were corrected for topographic and vegetation canopy effects. The event was preceded by cold, stormy conditions that developed a significant snow cover over the sub-basin. The snow cover at sites protected by forest cover was slightly reduced, while at open sites significant snowmelt occurred. The warm, moist, windy conditions during the flooding event produced substantially higher melt rates in exposed areas, where sensible- and latent-heat exchanges contributed 60–90% of the energy for snowmelt. Simulated snow-cover development and ablation during the model run closely matched measured conditions at the two experimental sites. This experiment shows the sensitivity of snowmelt processes to both climate and land cover, and illustrates how the forest canopy is coupled to the hydrologic cycle in mountainous areas.
The effects of gravity darkening on the ultraviolet continuum polarization produced by circumstellar disks

We investigate the effects of gravity darkening on the UV continuum polarization produced by an axisymmetric disk that surrounds a rapidly rotating star. Although the model is a single scattering approximation, we do include the effects of attenuation (electron scattering plus hydrogen bound-free absorption) by the disk, using an approach similar to that of Sobolev (1963). Because of the gravity darkening of the star and the attenuation within the disk, the radiation field is not axially symmetric about the radius vector. This implies that the polarization source functions are no longer provided by the finite disk depolarization factors of Cassinelli, Nordsieck, & Murison (1987), which are functions of the intensity moments in a spherically symmetric atmosphere. We reformulate the polarization source functions using generalized intensity moment tensors (J, H(sub i), K(sub ij)) that are valid for an arbitrary radiation field and envelope geometry. We find that the polarization source functions are simplest when using intensity moments in the observer's reference frame. On the other hand, the intensity moments are most easily evaluated in the stellar reference frame. Using the rotation transformation properties of the generalized intensity moments, we relate the observer's moments to those evaluated in the stellar reference frame. Our procedure for determining the polarization source functions thus merely involves choosing a set of Euler angles for the coordinate rotations, and then evaluating the associated rotation matrix. The geometrical complications of polarization transfer are thus reduced to obtaining a coordinate rotation matrix.
Recent progress on the Poincaré conjecture and the classification of 3-manifolds

If M is a closed 3-manifold with trivial fundamental group, then is M diffeomorphic to S? The Poincare Conjecture is that the answer to this question is “Yes.” Developing tools to attack this problem formed the basis for much of the work in 3-dimensional topology over the last century, including for example, the proof of Dehn’s lemma and the loop theorem and the study of surgery on knots and links. In the 1980’s Thurston developed another approach to 3-manifolds, see [24] and [4]. He considered 3-manifolds with riemannian metrics of constant negative curvature −1. These manifolds, which are locally isometric to hyperbolic 3-space, are called hyperbolic manifolds. There are fairly obvious obstructions showing that not every 3-manifold can admit such a metric. Thurston formulated a general conjecture that roughly says that the obvious obstructions are the only ones; should they vanish for a particular 3-manifold then that manifold admits such a metric. His proof of various important special cases of this conjecture led him to formulate a more general conjecture about the existence of locally homogeneous metrics, hyperbolic or otherwise, for all manifolds; this is called Thurston’s Geometrization Conjecture for 3-manifolds. The statement of this conjecture is somewhat complicated, so it is deferred until Section 2. An important point is that Thurston’s Geometrization Conjecture includes the Poincare Conjecture as a very special case. In addition, Thurston’s conjecture has two advantages over the Poincare Conjecture: • It applies to all closed oriented 3-manifolds. • It posits a close relationship between topology and geometry in dimension three.
Integrating Science and Mathematics: Perceptions of Preservice and Practicing Elementary Teachers

One hundred and sixty-one undergraduate elementary education majors and sixty elementary teachers completed an eight-item questionnaire designed to assess their perceptions toward integrating science and mathematics in the elementary grades. The two groups of subjects differed significantly on their responses to five of the eight items. Chi square analyses suggest that practicing elementary teachers felt they had more background in mathematics and science, were more aware of curriculum materials in this area, did not think that integration was currently a common practice, and were more likely to indicate that there was not sufficient time in the school day to integrate the subjects. Preservice teachers were more likely to indicate that integrating the disciplines was preferred to teaching them separately. In addition to the analyses of data, a list of recommendations are provided for teachers, curriculum developers, and policy makers interested in advancing the concept of integrating science and mathematics in instruction.