cssi/SciSciGPT-SciSciNet huggingface dataset:
Explorations of the origins of the reverse anomeric effect of the monosaccharides using the QVBMM (molecular mechanics) force field

Abstract The molecular modeling program STR3DI32.EXE, and its molecular mechanics module, QVBMM, were used to simulate and evaluate the stereo-electronic effects in the pyranoid analogs of the derivatives of monosaccharides that are known to display the reverse anomeric effect. This study has confirmed the importance of bond dipoles, particularly hydrogen bonding, in these effects. This study also holds considerable implications for unraveling the chemistry of glycoside formation and hydrolysis.
The Vanishing Native Reappears in the College Curriculum

(1991). The Vanishing Native Reappears in the College Curriculum. Change: The Magazine of Higher Learning: Vol. 23, No. 2, pp. 19-23.
Microchannel Plates for the UVCS and SUMER Instruments on the SOHO Satellite

The microchannel plates for the detectors in the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) and UVCS (Ultraviolet Coronograph Spectrometer) instruments aboard the Solar Orbiting Heliospheric Observatory (SOHO) mission to be launched in late 1995 are described. A low resistance Z stack of microchannel plates (MCP's) is employed in a detector format of 27 mm x 10 mm using a multilayer cross delay line anode (XDL) with 1024 x 360 digitized pixels. The MCP stacks provide gains of greater than 2 x 10(exp 7) with good pulse height distributions (as low as 25% FWHM) under uniform flood illumination. Background rates of approx. 0.6 event cm(exp -2) sec(exp -1) are obtained for this configuration. Local counting rates up to about 800 events/pixel/sec have been achieved with little drop of the MCP gain. MCP preconditioning results are discussed, showing that some MCP stacks fail to have gain decreases when subjected to a high flux UV scrub. Also, although the bare MCP quantum efficiencies are close to those expected (10%), we found that the long wavelength response of KBr photocathodes could be substantially enhanced by the MCP scrubbing process. Flat field images are characterized by a low level of MCP fixed pattern noise and are stable. Preliminary calibration results for the instruments are shown.
Subharmonic functions in n-connected domains

Abstract In this paper we investigate some of the properties of harmonic and subharmonic functions defined on n -connected domain G . In particular, we study the behavior of subharmonic functions at every point of the boundary of G . We prove that if f is subharmonic and u f is the least harmonic majorant of f then the lim sup taken along the normal to the boundary of G of f(z) P(z, x) converges to the singular part of the boundary measure of u f evaluated at x . The result is true for every x belonging to the boundary of G .
Effect of para substituents on the rate of bond shift in arylcyclooctatetraenes.

The rate constants for bond shift (kBS) in phenylcyclooctatetraene (1b) and its p-nitro and p-methoxy analogues (1a and 1c, respectively) in THF-d8 were determined by dynamic NMR spectrometry to be identical, but kBS is eight times greater at 280 K relative to 1b when the para substituent is cyclooctatetraenyldipotassium (22-/2K+). These results are discussed in the context of (a) possible intrinsically small substituent effects (as determined by 13C chemical shifts in the ground state (GS)) for 1a−c and (b) differences in steric interactions and resonance stabilization between the ground and BS transition state (TS). The latter factor was modeled by employing HF/3-21G(*) ab initio molecular orbital calculations of the GS and ring inversion TS. It is concluded that kBS is unchanged in 1a−c because the potentially greater π interaction in the BS TS is counterbalanced by a greater degree of twist between the aryl and COT rings resulting from increased steric hindrance relative to the GS. However, π interact...
Scheduling jobs across geo-distributed datacenters

With growing data volumes generated and stored across geo-distributed datacenters, it is becoming increasingly inefficient to aggregate all data required for computation at a single datacenter. Instead, a recent trend is to distribute computation to take advantage of data locality, thus reducing the resource (e.g., bandwidth) costs while improving performance. In this trend, new challenges are emerging in job scheduling, which requires coordination among the datacenters as each job runs across geo-distributed sites. In this paper, we propose novel job scheduling algorithms that coordinate job scheduling across datacenters with low overhead, while achieving near-optimal performance. Our extensive simulation study with realistic job traces shows that the proposed scheduling algorithms result in up to 50% improvement in average job completion time over the Shortest Remaining Processing Time (SRPT) based approaches.
Properties of high performance concrete systems incorporating large amounts of high-lime fly ash

Abstract This research was undertaken to evaluate the engineering properties of high-lime (ASTM Class C) fly ash concretes. An air-entrained reference concrete mixture without fly ash was proportioned to have 28-day compressive strength of 41 MPa. Additionally, concrete mixtures were also proportioned to have cement replacement with Class C fly ash in the range of 0–70% by weight. For each concrete mixture, specimens were made to evaluate compressive strength, tensile strength, flexural strength, modulus of elasticity, shrinkage, abrasion resistance, air permeability, water permeability, chloride ion permeability, air-void parameters, freezing and thawing durability, and salt scaling resistance, of hardened concrete. The results of this study established that high-performance concrete incorporating Class C fly ash at 30% cement replacement can be proportioned for high-strength applications. In general, concrete mixtures up to 50% cement replacement with fly ash showed satisfactory performance with respect to strength and physical durability properties appropriate for structural applications.
Early and intermediate-term (10-year) results of surgery for univentricular atrioventricular connection (“single ventricle”)

One hundred sixteen patients with "single ventricle" underwent 147 operations between 1967 and July 1982, with an actuarial survival rate (hospital deaths are included in all actuarials) at 10 years of 66%. One hospital death (2%) occurred after 45 primary "classic" shunting operations, and the 10-year actuarial survival was 85%. There were no hospital deaths after atrial septectomy or pulmonary artery banding, and the 10-year actuarial survival rate after these as initial procedures was 76% and 74%, respectively. Thirteen of 36 patients (36%) who underwent ventricular septation between 1967 and November 1, 1983, died in hospital. Among the 13 with the ideal morphologic characteristics of double inlet left ventricle without major associated cardiac anomalies, and without the need for valve replacement or a valved extracardiac conduit, there were no hospital deaths and a late survival rate of 77% (confidence limits 59 to 90%). Sixteen of 73 patients (22%), including those with tricuspid atresia, undergoing the Fontan-type procedure between 1967 and November 1, 1983, died in hospital. Multivariate analysis indicates that cardiac morphologic patterns other than tricuspid atresia are risk factors for hospital death in this group. The 10-year actuarial survival rate among the 73 patients was 71%, but only 1 death (associated with reoperation) occurred more than 2 months after operation. Ninety-seven percent of all surviving patients are in New York Heart Association functional class I or II, as are 100% of those who underwent septation and 96% of those who underwent the Fontan-type procedure.
The maximum size of a partial 3-spread in a finite vector space over GF(2)

Let n ≥ 3 be an integer, let Vn(2) denote the vector space of dimension n over GF(2), and let c be the least residue of n modulo 3. We prove that the maximum number of 3-dimensional subspaces in Vn(2) with pairwise intersection {0} is $${\frac{2^n-2^c}{7}-c}$$ for n ≥ 8 and c = 2. (The cases c = 0 and c = 1 have already been settled.) We then use our results to construct new optimal orthogonal arrays and (s, k, λ)-nets.
UPS in the Central Office; A TelCo engineer's perspective

The telecommunications industry is evolving toward a more distributed system architecture. Stored Program Controlled switching machines will interface with feature processors so new services can be integrated into the network. This is expected to reduce the financial outlays, and lead times previously expended to implement hardware dependent new features. Additionally, computerized Operational Support Systems are increasingly utilized for system testing, troubleshooting, and switch administration. Most of the computers used for these purposes are AC powered. The "Real time" nature of telephone service, the Volitile nature of some computer memory elements, and the necessity of system reliability accentuate the need for uninterruptible power. Accordingly, these systems are being deployed for use in the central office. For the moment, it appears that UPS is a technology more germane to the data processing side of the business, since this is where it evolved. This paper is intended to point out features which make an UPS system more utile to a telephone engineer or Operations Manager. Some features already exist in a few UPS systems, and some do not. Obviously, the systems best suited to the needs of the telecommunications customer, will enjoy a larger share of that market. Though highly developed, there are design alterations which could make UPS systems better suited to the central office environment.
The β-tubulin-encoding gene from Microbotryum violaceum: unusual in a variety of ways

The β-tubulin gene of Microbotryum violaceum was sought originally for its potential use in improving the transformation of this organism. The gene was cloned and its nucleotide sequence was determined. The gene was predicted to encode a 444-residue protein with strong sequence similarity to other β-tubulins. The coding region was 2.85 kb, much larger than the corresponding genes from other organisms. This was due to the large number of introns in this gene, as determined by comparison of the cDNA sequence with that for the genomic clone. This gene contained 14 introns, which is the most introns in a β-tubulin-encoding gene yet reported for any organism. Intron position comparisons between the M. violaceum gene and those from β-tubulin genes of other organisms revealed a striking result, since 10 of the 14 introns were unique. An additional feature of the gene's organization was an unusually long 5′ untranslated region, predicted to be nearly 1 kb in length. The possible significance of these unusual features of genetic structure is discussed.
Cranial shape and correlated characters in crocodilian evolution.

Crocodilians show a high degree of cranial variation and convergence throughout their 80 million-year fossil record that complicates their phylogenetic reconstruction. Conflicting phylogenetic results from different data partitions and character homoplasies typify crocodilian phylogeny, and differences between molecular and morphological phylogenetic hypotheses are believed to be associated with the slender-snout skull shape of Gavialis gangeticus and Tomistoma schlegelii. Slender-snout skulls are one of five identified eusuchian cranial ecomorph shape categories (ESCs) thought to reflect functional or ecological specialization. This paper tested the effect of transitions among general, blunt and slender ESCs on cranial character-state distributions in phylogeny using the concentrated changes test. In addition, ‘tree-free’ character compatibility analysis of character independence was conducted on the morphological character matrix to determine if character correlations are observed independent of specific tree topologies. Results suggest cranial ESCs do affect cranial character-state gains in phylogeny. Concentrated changes identify a broad suite of character-state changes that significantly correlate with transitions to slender, general and blunt ESCs on morphological, molecular and combined-data tree topologies, but numbers of correlated characters for each category differ according to topology. Character compatibility analysis results do not mirror the concentrated changes test results and reflect hierarchically distributed support throughout the data. As cranial ESCs affect character-state transitions, it is possible that nonphylogenetic variables could affect inferences of crocodilian phylogeny by affecting cranial morphology.
Human Neutrophils Use the Myeloperoxidase-Hydrogen Peroxide-Chloride System to Chlorinate but Not Nitrate Bacterial Proteins during Phagocytosis

The generation of extracellular oxidants by neutrophils has been widely investigated, but knowledge about the chemical reactions that occur in the phagolysosome, the cellular compartment that kills pathogens, is more limited. One important pathway may involve the production of potent halogenating agents such as hypochlorous acid (HOCl) by the myeloperoxidase-hydrogen peroxide-halide system. However, explorations of the oxidation chemistry of phagolysosomes have been hampered by the organelle's inaccessibility. To overcome this limitation, we recovered Escherichia coli that had been internalized by human neutrophils. We then analyzed the bacterial proteins for 3-chlorotyrosine, a stable marker of damage by HOCl. Mass spectrometric analysis revealed that levels of 3-chlorotyrosine in E. coli proteins increased markedly after the bacteria were internalized by human neutrophils. This increase failed to occur in E. coli exposed to neutrophils deficient in NADPH oxidase or myeloperoxidase, implicating H(2)O(2) and myeloperoxidase in the halogenation reaction. The extent of protein chlorination by normal neutrophils paralleled bacterial killing. Our observations support the view that the phagolysosome of human neutrophils uses the myeloperoxidase-hydrogen peroxide-chloride system to chlorinate bacterial proteins. In striking contrast, human neutrophils failed to nitrate bacterial proteins unless the medium was supplemented with 1 mm nitrite, and the level of nitration was low. Protein chlorination associated with bacterial killing was unaffected by the presence of nitrite in the medium. Nitration required NADPH oxidase but appeared to be independent of myeloperoxidase, suggesting that neutrophils can nitrate proteins through a pathway that requires nitrite but is independent of myeloperoxidase.
NaCl doping and the conductivity of agar phantoms

Abstract A recipe for manipulating the conductivity of agar impedance-imaging phantoms through their NaCl (salt) content is reexamined. The conductivities at frequencies 100 kHz and below are characterized for phantoms created with the recipe. The data are compared against the recipe's predictive formula for conductivity as a function of salt content. Based on analysis of the data a modified version of the conductivity formula is generated. The modified predictive formula better approximates the observed NaCl dependence of conductivity in phantoms with salt concentrations under 0.1 M. The experimental data also provide verification for the asymptotic dependence of contact impedance on frequency and phantom conductivity. The results of these experiments will be helpful in better constructing agar phantoms to electrical specifications for future impedance-imaging experiments.
Introduction to Permutation and Resampling-Based Hypothesis Tests

A resampling-based method of inference -- permutation tests -- is often used when distributional assumptions are questionable or unmet. Not only are these methods useful for obvious departures from parametric assumptions (e.g., normality) and small sample sizes, but they are also more robust than their parametric counterparts in the presences of outliers and missing data, problems that are often found in clinical child and adolescent psychology research. These methods are increasingly found in statistical software programs, making their use more feasible. In this article, we use an application-based approach to provide a brief tutorial on permutation testing. We present some historical perspectives, describe how the tests are formulated, and provide examples of common and specific situations under which the methods are most useful. Finally, we demonstrate the utility of these methods to clinical and adolescent psychology by examining four recent articles employing these methods.
Multilevel atomicity—a new correctness criterion for database concurrency control

Multilevel atomicity, a new correctness criteria for database concurrency control, is defined. It weakens the usual notion of serializability by permitting controlled interleaving among transactions. It appears to be especially suitable for applications in which the set of transactions has a natural hierarchical structure based on the hierarchical structure of an organization. A characterization for multilevel atomicity, in terms of the absence of cycles in a dependency relation among transaction steps, is given. Some remarks are made concerning implementation.
Pyruvate flux into resealed ghosts from human erythrocytes

Abstract The kinetics of pyruvate transport across the isolated red blood cell membrane were studied by a simple and precise spectrophotometric method: following the oxidation of NADH via lactate dehydrogenase trapped within resealed ghosts. The initial rate of pyruvate entry was linear. Influx was limited by saturation at high pyruvate concentration. Pyruvate influx was greatly stimulated by increasing ionic strength in the outer but not the inner aqueous compartment. The K m ranged from 15.0 mM at μ = 0.05 to 3.7 mM at μ = 0.01 , while the V went from 0.611 · 10 -15 to 0.137 · 10 -15 mol · min -1 · ghost -1 . Ionic strength was shown to affect the translocation step and not pyruvate binding. The energy of activation of pyruvate flux into resealed ghosts was 25 kcal/mol, similar to that found in intact red blood cells. Inhibitors of pyruvate influx included such anions as thiocyanate, chloride, bicarbonate, α-cyanocinnamate, salicylate and ketomalonate (but not acetate); noncompetitive inhibitors were phloretin, 1-fluoro-2,4-dinitrobenzene, 4-acetamido-4′-isothiocyanate-stilbene-2,2′-disulfonic acid and o-phenanthroline/CuSO4 mixtures. The last reagent, known to induce disulfide links in certain membrane proteins, blocked the ionic strength stimulation of pyruvate influx in this study.
Estradiol Supplementation Enhances Submaximal Feed-Forward Drive of Growth Hormone (GH) Secretion by Recombinant Human GH-Releasing Hormone-1,44-Amide in a Putatively Somatostatin-Withdrawn Milieu

To test the clinical hypothesis that an estrogen-enriched milieu enhances GHRH action, we administered placebo (Pl) and estradiol-17β (E2) orally for 23 d to six postmenopausal women in a prospectively randomized, double-masked, within-subject crossover design with 6 wk intervening. The GHRH stimulation protocol entailed consecutive iv infusion of l-arginine and a single iv pulse of saline or one of five randomly ordered doses of recombinant human GHRH-1,44-amide (0.03, 0.1, 0.3, 1.0, or 3.0 μg/kg) in a total of 12 separate morning, fasting sessions. GH secretion was monitored by sampling blood every 10 min for 6 h; chemiluminescence assay of GH concentrations; deconvolution analysis of stimulated GH release; and nonlinear dose-response reconstruction. Supplementation with E2, compared with Pl: 1) increased (mean ± sem) E2 concentrations from 18 ± 3 (Pl) to 164 ± 12 pg/ml (to convert to picomoles per liter, multiply by 3.57) (P < 0.001); 2) decreased IGF-I concentrations from 181 ± 14 to 120 ± 11 μg/liter...
Sex differences in clinical presentation and response in panic disorder: pooled data from sertraline treatment studies

Objective. Gender differences in clinical presentation and response to sertraline treatment were examined for patients diagnosed with DSM-III-R panic disorder with or without agoraphobia. Method. Data was pooled from 4 double-blind, placebo-controlled outpatient studies (males, N = 335; females, N = 338). Two were 12-week fixed-dose studies (sertraline 50 mg vs. 100 mg vs. 200 mg) and 2 were 10-week flexible-dose studies (sertraline 50–200 mg). Primary outcome measures consisted of the Clinical Global Impression-Improvement scale (CGI-I) and change in panic attack frequency. Results. The clinical presentation of panic disorder was similar except that men reported an earlier age of onset, shorter duration of illness, and significantly more frequent history of alcohol and/or substance dependence/abuse. Sertraline was significantly more effective than placebo in both women and men on the 2 primary outcome measures. When between-sex efficacy was compared, women achieved significantly greater improvement than men on panic frequency and CGI-I, but had equivalent improvement on all other measures. There was no significant between-sex difference in study completion rates, or in adverse event profiles. Conclusions. There was a modest but consistent trend for women to show superior efficacy at the end of acute sertraline treatment. This gender effect only occasionally achieved significance, and must be confirmed by future treatment research.
Hormone replacement therapy alters insulin sensitivity in young women with premature ovarian failure

In this study, we report the effects of cyclic hormone replacement therapy on carbohydrate metabolism in six women with premature ovarian failure. Using tolbutamide-modified iv glucose tolerance tests patients were evaluated during three different intervals of their second treatment cycle: no hormone replacement, estradiol-only (E2-only) replacement, and E2-plus-medroxyprogesterone acetate (MPA) replacement. Insulin sensitivity and glucose effectiveness were derived using insulin and glucose levels obtained from tolbutamide-modified iv glucose tolerance tests and analyzed with the minimal model computer program. The mean insulin sensitivity (x 10(-4)/min/microU.ml) significantly decreased from 4.0 +/- 0.8 during no hormone replacement and 3.8 +/- 0.8 during E2-only replacement to 2.6 +/- 0.5 (x 10(-4)/min/microU/ml) during E2-plus-MPA replacement (P < 0.005). Glucose effectiveness did not change as a function of the phase of hormone replacement therapy. These findings indicate a significant decrease in sensitivity to insulin associated with MPA treatment but no observable change in insulin sensitivity during the E2-only phase of cyclic steroid replacement therapy in young women. Our results support the hypothesis that impairment of insulin-mediated glucose uptake during the luteal phase of the menstrual cycle is due to increased progesterone secretion.
Near-infrared photoacoustic diagnostics in biomedicine: analysis of thermal safety and light-tissue interactions

Medical diagnostic devices based on photoacoustics represent an emerging area with significant potential for evaluation of brain injury and chemical agent exposure, as well as detection of pandemic diseases and cancer. However, few studies have addressed photothermal safety of these devices which emit high-power laser pulses to generate rapid, selective, yet non-destructive heating of subsurface structures. Towards elucidation of laser-tissue interactions and factors of safety for photothermal injury, we have developed a three-dimensional numerical model including light propagation, heat transfer and thermal damage algorithms. Literature surveys were performed to identify appropriate optical properties and the range of device exposure levels implemented in prior in vivo studies. Initial simulations provided model validation against results from the literature. Simulations were then performed based on breast tissue with discrete blood vessels irradiated by a train of laser pulses (10 Hz) at 800 and 1064 nm. For a constant exposure level, increasing beam diameter from 0.2 to 2.0 cm led to a factor of 2.5 increase in subsurface heat generation rates. Our preliminary modeling results indicate that for a 10 second tissue exposure under standard photoacoustic imaging conditions, irradiance-based safety limits should provide a factor of safety of 6 or greater over exposure levels that induce thermal coagulation. Opticalthermal modeling represents a powerful tool for elucidating photothermal effects relevant to the safety and effectiveness of photoacoustic systems.
Identification of the Rts 1 DNA fragment responsible for temperature sensitive growth of host cells harboring a drug resistance factor Rts 1

We have placed a kanamycin resistance SalI fragment (3.65 Kb) from the drug resistance factor Rts1 into pUC19 and pBR322. These chimeric plasmids containing the kanamycin resistance fragment from Rts1 cause temperature sensitive growth in E coli. The orientation of the kanamycin resistance fragment in the vector plasmids does not influence this phenotype.
Salt weathering: influence of evaporation rate, supersaturation and crystallization pattern

Micro- and macroscale experiments which document the dynamics of salt damage to porous stone have yielded data which expose weaknesses in earlier interpretations. Previously unexplained differences are found in crystal morphology, crystallization patterns, kinetics and substrate damage when comparing the growth of mirabilite (Na2SO4. 10H2O) and thenardite (Na2SO4) versus halite (NaCl). The crystallization pattern of sodium sulphate was strongly affected by relative humidity (RH), while a lesser RH effect was observed for sodium chloride. Macroscale experiments confirmed that mirabilite (crystallizing at RH > 50 per cent) and thenardite (crystallizing at RH < 50 per cent) tend to form subflorescence in highly localized areas under conditions of constant RH and temperature. This crystallization pattern was more damaging than that of halite, since halite tended to grow as efflorescence or by filling the smallest pores of the stone in a homogeneous fashion, a result which contradicts Wellman and Wilson's theoretical model of salt damage. Low RH promoted rapid evaporation of saline solutions and higher supersaturation levels, resulting in the greatest damage to the stone in the case of both sodium sulphate and sodium chloride crystallization. At any particular crystallization condition, sodium chloride tended to reach lower supersaturation levels (resulting in the crystallization of isometric crystals) and created negligible damage, while sodium sulphate reached higher supersaturation ratios (resulting in non-equilibrium crystal shapes), resulting in significant damage. ESEM showed no damage from sodium sulphate due to hydration. Instead, after water condensation on thenardite crystals, rapid dissolution followed by precipitation of mirabilite took place, resulting in stone damage by means of crystallization pressure generation. It is concluded that salt damage due to crystallization pressure appears to be largely a function of solution supersaturation ratio and location of crystallization. These key factors are related to solution properties and evaporation rates, which are constrained by solution composition, environmental conditions, substrate properties, and salt crystallization growth patterns. When combined with a critical review of salt damage literature, these experiments allow the development of a model which explains variations in damage related to combinations of different salts, substrates and environmental conditions.
Advances in size-exclusion separations of proteins and polymers by UHPLC

Abstract The separation of molecular compounds based on their capacity to access the intra-particle pore volume of chromatographic media, which is dictated by the relative size in solution of those compounds, has been commonly known as size-exclusion chromatography (SEC) or gel-permeation chromatography (GPC). Conventionally, these two terms have been applied to the analysis of biomolecules and polymers, respectively. Over the more than half-a-century history of size-based separations, there has been a series of advancements, starting from the earliest soft-gel particles and culminating within the past few years in the use of sub-2-µm particles in ultra-high-performance liquid chromatography (UHPLC). The intent of this review is to provide a concise synopsis of the advancements of both chromatography columns and instrumentation for protein and polymer size-based separations. Also, this review presents brief summaries of the application of UHPLC technology for these classes of analytes.
Impact of screening versus symptomatic measurement of deep vein thrombosis in a national quality improvement registry

Background Deep vein thrombosis (DVT) is a quality measure recorded by initiatives such as the National Surgical Quality Improvement Program (NSQIP). However, because surveillance-detected DVT rates may be higher than symptomatic DVT rates, we examined how differences in the method of DVT detection may affect the use of this quality measure. Methods Using the NSQIP database (2007-2009), we compared DVT rates of vascular (amputation, open aortic procedures, and lower extremity bypass) and nonvascular (prostatectomy, gastric bypass [GBP], and hip arthroplasty) operations. Using a predefined literature search strategy, we compared the incidence of DVT in NSQIP to the incidence of DVT reported in published literature, diagnosed by symptomatic status or by surveillance studies. Results Within NSQIP, the overall incidence of postoperative DVT was 0.7%. This varied from 0.3% after GBP to 1.8% after open aortic surgery. Across all procedures except amputation, the incidence of DVT in NSQIP was similar to the incidence of DVT reported in our literature survey of "symptomatic" DVTs. The relative rate (RR) of literature-derived symptomatic DVTs to NSQIP ranged from 0.7 for aortic cases (95% confidence interval [CI], 0.3-1.7) to 1.4 (95% CI, .7-3.1) for GBP. Overall, surveillance studies had 11.6 higher RR of DVT compared to NSQIP (95% CI, 10.5-13), ranging from 2.6 for GBP (95% CI, 1.4-5) to 14 .5 for hip arthroplasty (95% CI, 10.5-20). Conclusions The incidence of DVT reported in NSQIP is similar to the reported incidence of symptomatic DVT for many high-risk procedures but is much lower than rates of DVT reported in surveillance studies. Clear delineation of symptomatic vs surveillance detection of DVT would improve the usefulness of this measurement in quality improvement registries.
A Display Based On Switchable Zero Order Diffraction Grating Light Valves

A flat panel display technology has been conceived which utilizes a matrix of line addressable light valves back lighted with a partially collimated source. The basic pixel element of the display is an optical switch based on the zero order of diffraction by two aligned transmission phase gratings. The transmission of light is modulated by mechanic-ally displacing one grating with respect to the other by one-half of the grating period. The color transmitted by the light valve is controlled by the grating profile. Optical spectra of a large-scale prototype of the switchable light valve element are in good agreement with calculations according to simple diffraction theory. Technology for the construction of an optical switch of the desired size has been developed, with 85% of the area devoted to light transmission. The elements are one millimeter squares made of polyvinylidene fluoride (PVDF), a transparent, piezoelectric plastic. Gratings of nearly square profile with 3.8 micron period are produced in 9 micron films of PVDF by embossing at 4000 bars and 70A‚Â°C and show the expected optical transmission spectra. Mechanical displacement is produced by applying voltage to two sets of bending arms attached to either side of the movable element. The bending arms amplify motion due to piezoelectric strain. Nickel electrodes are patterned onto the PVDF film by photolithography and liftoff. Perforations around the movable element and the bending arms are etched through the film by reactive ion etching in oxygen, using patterned aluminum as a mask. Motion exceeding 2 microns has been observed, which is sufficient to operate the light valve.
ASTM Activities in Neutron Radiography

Neutron radiography emerged from the laboratory into an NDT environment that demanded standards for quality and performance. Many NDT areas were established before the advent of these standards. Neutron radiography, on the other hand, faced immediate pressure to produce standards in the shortest possible period of time. To further complicate matters, neutron radiography began its commercial life in high reliability aerospace applications which demanded rigid controls. In response to this obvious need the American Society for Testing and Materials has provided the formal mechanism for producing these standards since 1971 when Committee E-7 on Nondestructive Testing established section E07.01.02.
Clinical biochemical genetics in the twenty-first century

Genetic disorders are recognized to play an increasing role in pediatrics. Close to 10% of diseases among hospitalized children have been ascribed to Mendelian traits inherited as single gene defects, not a surprising figure considering that approximately 1000 inborn errors of metabolism (IEM) have been identified to date, primarily through the detection of endogenous metabolites abnormally accumulated in biological fluids and tissues. The laboratory discipline that covers the biochemical diagnosis of IEM is known as clinical biochemical genetics, and is defined as one concerned with the evaluation and diagnosis of patients and families with inherited metabolic disease, monitoring of treatment, and distinguishing heterozygous carriers from non-carriers by metabolite and enzymic analysis of physiological fluids and tissues. The biochemical genetics laboratory differs from the clinical chemistry laboratory in the extent of interpretation necessary to make its results meaningful to the clinician. While dramatic advances in molecular genetics have greatly changed the landscape of diagnostic options for many genetic disorders, a biochemical approach remains the dominant force for the diagnosis and monitoring of IEM. Owing to the stereotypical clinical presentation of many of these disorders, a major role of the biochemical genetics laboratory is to analyze ever more complex metabolic profiles to reach a preliminary diagnosis, which then needs to be confirmed by enzymic and/or molecular studies in vitro. Accordingly, the role of biochemical genetics in the pediatric practice of the 21st century is to provide a multicomponent screening process that can be divided into four major components: (i) at-risk screening (prenatal diagnosis); (ii) newborn screening (testing of presymptomatic patients); (iii) high-risk screening (testing of symptomatic patients); and (iv) postmortem screening (metabolic autopsy). The focus of our laboratory is to apply state-of-the-art technology such as tandem mass spectrometry to bring as many as possible IEM within the boundaries of newborn screening programs, and to investigate the role played by individual disorders in maternal complications of pregnancy, pediatric acute/fulminant liver failure, and sudden and unexpected death in early life.
Pineal sensitivity to pulsed static magnetic fields changes during the photoperiod

The effect of pulsed static magnetic fields on the rat pineal melatonin synthesis was studied at different times of the photoperiod. Exposure to magnetic fields during mid- or late dark phase significantly suppressed pineal N-acetyltransferase activity, the rate-limiting enzyme in melatonin synthesis, as well as the melatonin content in the pineal gland. These parameters were not influenced by magnetic fields when the exposure occurred early in the dark phase or during the day. These results suggest that the responsiveness of the pineal gland to magnetic field perturbations changes throughout the photoperiod.
Photomodulation spectroscopy of dangling bonds in doped and undoped a-Si:H

Abstract The energy levels and the effective correlation energy U eff of dangling bond defects in doped and undoped a Si:H were determined by the steady state and transient photomodulation spectroscopy. We found that in undoped a Si:H the two dangling bond levels (D ± ) are symmetrically located around midgap with U eff of 0.5 ± 0.1 eV, whereas in P(B) doped a Si:H the states D - (D + ) are pushed away from the conduction (valence) band toward midgap and U eff = 0.4 ± 0.1 eV .
Diminished cardiac vagal tone in schizophrenia: Associations to brain laterality and age of onset

We measured high-frequency (rapid) heart rate variability (HRV) from 24-hour Holter electrocardiograms to index cardiovagal tone in 23 patients with DSM-III-R schizophrenia or schizoaffective disorder. High-frequency HRV, quantitated by measuring the percent of successive normal interbeat intervals greater than 50 msec (PNN50), demonstrated a bimodal distribution: 11 of 23 patients had a PNN50 of ≥ 8.0 (mean value = 17.7 ± 11.0), and 12 had a PNN50 of ≤ 4.0 (mean value = 1.8 ± 1.0); no subject had a PNN50 value between 4.0 and 8.0. All 12 low cardiovagal tone patients (versus only 6/11 of the other patients) had a schizophrenia (not schizoaffective) diagnosis (p = .013). PNN50 was not associated with present age, gender, smoking, IQ scores, or symptomatology, but patients with lower cardiovagal tone did have a significantly later age of onset (20.5 ± 5.3 vs. 14.8 ± 2.8 years: p = .005). PNN50 subgroups also differed on dichotic listening measures of brain laterality. The low group failed to show left ear (right hemisphere) advantage for complex tones seen in the other patients and normal adults. They also showed larger right ear (left hemisphere) advantage for dichotic words than the other patients. This evidence of relative right hemisphere disadvantage in patients with low cardiovagal tone is consistent with findings linking autonomic nervous system and right hemisphere function. These findings also support the existence of subgroups of schizophrenia patients differing in autonomic activity, brain laterality, and clinical features.
Some aspects of the metabolic fate of 14C-labeled alanine and aspartic acid in the aging female mosquito, Aedes aegypti (L.) (Diptera: Culicidae)

Abstract 1. 1. Certain aspects of the metabolic fate of 14 C-labeled alanine and aspartic acid were studied in the adult female mosquito, Aedes aegypti (L.). 2. 2. Three tissue fractions were analyzed for radioactivity by liquid scintillation counting, amino acid fraction, lipid fraction and protein fraction; all three fractions revealed radioactivity. 3. 3. Mosquitoes were found to expire 14 CO 2 at a rather high rate shortly after uptake of the labeled compounds followed soon after by a sharp decline to alow but steady rate of release. 4. 4. Analysis of excreta revealed a very low activity indicating very little loss of 14 C by this route.
Programming and modification in the SHARE 709 system

Abstract : The SHARE 709 system permits the programmer to communicate with the machine and with itself entirely in a symbolic language. The compiler specifications including instruction format, pseudo operations, program library, and system and programmer-macro operation generators are described. The methods for handling symbolic input/output, symbolic debugging, and symbolic modification of a compiled program are discussed. (Author)
Properties of Gallium Nitride

Gallium nitride has many useful properties that include a large direct gap, high electrical and thermal conductivities, and nearly the hardness of sapphire. GaN decomposes at -100°C, can sustain high electron velocities and exhibit acoustoelectric effects. But two challenges remain: to make it conducting p-type and to synthesize the cubic phase in a large single crystal instead of the usual hexagonal structure.
Singular Pair Breaking in the Composite Fermi Liquid Description of the Half-Filled Landau Level

Fluctuations of the Chern-Simons gauge field in the composite Fermi liquid description of the half-filled Landau level are pair breaking in all angular momentum channels. For short-range electron-electron interactions these fluctuations are sufficiently strong to drive any T=0 pairing transition first order. For Coulomb interactions these fluctuations are weaker and a continuous transition is possible. {copyright} {ital 1999} {ital The American Physical Society }
Similarity of Synonymous Substitution Rates Across Mammalian Genomes

Given that a gene has a high (or low) synonymous substitution rate in one mammalian species, will it also have a high (or low) synonymous substitution rate in another mammalian species? Such similarities in the rate of synonymous substitution can reveal both selective pressures and neutral processes acting on mammalian gene sequences; however, the existence of such an effect has been a matter of disagreement. We resolve whether such synonymous substitution rate similarities exist using 7462 ortholog triplets aligned across rat, mouse, and human, a dataset two orders of magnitude larger than previous studies. We find that a gene’s synonymous substitution rate in the rat-mouse branch of the phylogeny is correlated with its rate in the branch connecting human and the rat-mouse ancestor. We confirm this for several different measures of synonymous substitution rate, including corrections for base composition and CpG dinucleotides, and we verify the results in the larger mouse-human-rat-dog phylogeny. This similarity of rates is most apparent for genes in which synonymous sites are well conserved across species, suggesting that a significant component of the effect is due to purifying selection. We observe rate correlations at a resolution as fine as a few hundred kilobases, and the genes with the most similar synonymous substitution rates are enriched for regulatory functions. Genes with above-average substitution rates also exhibit significant, though somewhat weaker, rate correlations, suggesting that some neutral processes may have persisted in the phylogeny as well.
“Blockers” do not block recall during tip-of-the-tongue states

Tip-of-the-Tongue experiences (TOTs) are often accompanied by incorrect answers (blockers) that come to mind persistently and seem to block recall. According to the blocking hypothesis, blockers cause retrieval difficulty during TOTs. We predicted that delay would allow participants to forget their blockers, and thereby enhance TOT resolution. In Experiment 1 participants were asked trivia questions and then retested on the ones that elicited TOTs, either immediately or after a delay. There was an incubation effect overall, with greater TOT resolution after a delay than on an immediate test. Contrary to the blocking hypothesis, however, delay did not enhance resolution of blocked TOTs more than non-blocked TOTs. In Experiment 2, during the retest, participants were reminded of their previous blockers on some questions, but the reminders did not affect TOT resolution. These findings suggest that blockers may be a side effect, not a cause, of retrieval difficulty during TOTs.
A network model of distributed and centralized systems of students

The body of knowledge in active and cooperative learning lacks an analytical model to determine the emergent patterns of distributed (active, student centered) and centralized (traditional, teacher centered) networks of students. To address the complexity of learning systems a network modeling approach based on Social Network Analysis and Ecological Network Analysis is proposed as an appropriate scientific construct for developing analytical techniques for studying and understanding learning systems. Models were developed, designed, and interpreted for two configurations, one with four actors and another with 16 actors. A preliminary analysis was performed on a 12 actor model to determine the optimal cluster size to maximize indirect effects within the system. In the future, network models can be utilized to further understand learning systems through network properties that are not directly observable. It is the aim of the authors to provide an additional lens to view, assess, and optimize student learning.
PARTITIONING AVERAGE AND HETEROTIC COMPONENTS OF DIRECT AND MATERNAL GENETIC EFFECTS ON GROWTH IN MICE USING CROSSFOSTERING TECHNIQUES

Crossfostering was performed using lines selected for increased 6-week body weight (H6) and increased 3-to 6-week postweaning gain (M16) and their reciprocal F1 crosses as nurse dams in the selected crossfostering group, and base population controls (C2, ICR) and their reciprocal F1 crosses in the control group. The offspring suckled were H6, M16 and F2 crosses in the selected group, and C2, ICR and their F2 crosses in the control group. Measurements taken on the individual offspring were body weights at birth (WB) and at 12, 21, 31, 42, and 63 days (W12, W21, W31, W42 and W63, respectively) and weight gains between adjacent ages (GB-12, G12–21, G21–31, G31–42 and G42–63, respectively). Least squares constants fitted to populations of genetic and nurse dams were used to calculate specific linear contrasts. Correlated responses to selection in average direct genetic effects were significant and positive for all traits examined in both H6 and M16, while the correlated responses in average maternal genetic effects were negative in M16 and negligible in H6. Selection response was primarily due to average direct genetic effects while the contribution of average maternal genetic effects was of secondary importance. The response in average direct genetic effects was smaller in M16 than in H6 through weaning (WB, W12 and W21), but was larger in M16 for postweaning weights (W31, W42 and W63). The correlated responses in average maternal genetic effects were consistently smaller in M16 than in H6. Direct heterosis was significant for all traits except for G12–21 and G42–63 in the control group, whereas maternal heterosis was significant for weight gains at early ages and for body weights. Direct heterosis tended to be larger than maternal heterosis in both selected and control crosses. Percent direct heterosis for body weight was larger in the selected crosses relative to the control crosses through 31 days of age, but the trend was reversed by 63 days. Percent maternal heterosis was consistently larger in the selected crosses.
Constrained stabilization of dynamic systems described by vector differential equations

This paper considers the stability and constrained stabilization of dynamic systems described by second or higher order vector differential equations. Such systems arise in various applications including electromechanical systems, aerodynamics, structural analysis, robotics and vibration systems, in which the stabilization and improved performance play a crucial role. Due to the fact that the coefficient matrices of vector differential systems have special structures, it is of particular interest to maintain their structural properties while performing the design. The class of Metzlerian matrices is used as a constraint in the stabilization problem. Specifically, we provide a simple method to construct a stable feedback control law such that the closed-loop system matrix has the desired eigenvalues and maintains its original block companion structure with Metzlerian blocks.