cssi/SciSciGPT-SciSciNet huggingface dataset:
Developmental dysplasia of the hip

1. Blaise A. Nemeth, MD, MS* 2. Vinay Narotam, MD† 1. *Associate Professor, Department of Orthopedics and Rehabilitation, University of Wisconsin School of Medicine and Public Health, Madison, WI. 2. †Assistant Professor, Department of Orthopaedics, University of North Carolina School of Medicine, Chapel Hill, NC. * Abbreviations: AVN: : avascular necrosis DDH: : developmental dysplasia of the hip Early detection of developmental dysplasia of the hip is essential because restoration of the normal relationship of the femoral head and acetabulum increases the likelihood of normal development. Pediatricians must be aware of the American Academy of Pediatrics guidelines for early detection. After completing this article, readers should be able to: 1. Acknowledge the spectrum of hip pathology included in developmental dysplasia of the hip (DDH). 2. Identify newborns at risk for DDH. 3. Diagnose hip dislocations by using appropriate physical examination maneuvers. 4. Appropriately use imaging modalities to screen for DDH in infants who have normal or equivocal physical findings. 5. Recognize the presentation of hip dislocation in the older child. Developmental dysplasia of the hip (DDH) encompasses the spectrum of hip abnormalities involving the relationship between the femoral head and the acetabulum during early growth and development. A hip may be dislocated at rest, dislocatable (but in a normal position at rest), subluxed (incomplete contact between the femoral head and acetabulum), subluxable (incomplete contact induced with provocative maneuvers), or appear normal on physical examination yet have an abnormally shaped acetabulum or femoral head radiographically. The previously used term, “congenital hip dislocation,” has been abandoned in recognition of this spectrum, acknowledging as well the fact that a child may have normal examination findings at birth but progress to dislocation later in life. Strictly speaking, the term DDH does not apply to abnormal development of the hip due to other diseases, such as cerebral palsy, Legg-Calve-Perthes disease, or slipped capital femoral epiphysis, in which “hip dysplasia” is a sufficient term, nor does the term include traumatic dislocation. In addition, the term “teratologic dislocation” is reserved …
A transmission electron microscopy study of the mechanisms of strengthening in heat-treated Co-Cr-Mo-C alloys

Microstructures produced in the Co-Cr-Mo-C alloy H.S.21 were observed by transmission electron microscopy in cast specimens following solutionizing at 1230°C and aging at 650°C and in low-carbon wrought specimens following solutionizing and aging at 650°C and 750°C. In all cases, aging was found to promote the formation of fcc stacking faults and to cause an initial martensitic transformation from the fcc phase to a heavily faulted hep structure. Precipitate formation was observed in hcp areas of the cast material after 20 h at 650°C and in hcp areas of wrought material after 20 h at 750°C. Prolonged aging at 750°C produced a transformation in the hcp structure of wrought specimens, with a relatively fault-free structure replacing the heavily faulted martensitic form. Interruption of fcc slip by both fcc stacking faults and bands of hcp phase was found to be the principal strengthening mechanism activated by aging. Precipitate formation in the hcp plays an increasingly significant role as aging time is increased. This microstructural information is used to explain the observed tensile properties of these alloys after the heat treatments mentioned.
Luminescence lifetime distribution in amorphous semiconductors

The fate of an isolated electron-hole pair created by light on a close pair of localized tail states is described at low temperatures by the geminate function P(R) which is the probability density to recombine radiatively at a separation R. The function P(R) has a maximum at R = Rc ≡ (a/2) ln (v0τ0) (v0 and 1/τ0 are, respectively, the characteristic frequencies of phonon-assisted hopping and of radiative recombination and α is the localization length) and a long tail for R > Rc. It was suggested that P(R) gives the distribution of the logarithms of radiative lifetimes in the limit of small generation rates G when the average distance between photocarriers is n−1/3 ≫ Rc in steady state. The present work shows that a second quite narrow peak should appear in the distribution of lifetimes corresponding to recombination at R ⋍ n−1/3/2. A two peak structure in the luminescence lifetime distribution should occur in semiconductors having small hopping rates due to polaron effects, leading to small Rc. In a-Si:H, Rc is relatively large so that typically Rc
Management of sarcomatoid salivary duct carcinoma of the submandibular gland duct with coexisting seropositive human immunodeficiency virus.

Background: Sarcomatoid salivary duct carcinoma of the submandibular gland is extremely rare. This paper highlights the impact of surgery and adjuvant radiation therapy on the outcome of this disease. Methods: A 59-year-old man with human immunodeficiency virus presented with a painless, rapidly growing left neck mass. Biopsy followed by surgical excision of the left submandibular gland revealed sarcomatoid salivary duct carcinoma of the submandibular gland duct with perineural invasion and close margins, for which he underwent adjuvant radiotherapy. Post-operative positron emission tomography and computed tomography revealed no residual or metastatic disease. Pathological analysis of tumour–node–metastasis staging revealed a T 2 N 0 M 0 (stage II) tumour. Results: The patient tolerated his treatment without serious acute or long-term side effects. There was no evidence of disease on comprehensive examination or on positron emission tomography or computed tomography scans at the 4.6-year follow up. Conclusion: Surgery followed by adjuvant radiotherapy provided practical locoregional control with acceptable toxicity. Further detailed case reports are warranted to optimise the management of this rare malignancy.
On the structure of Co4(CO)12 in solution

Abstract 59Co chemical shifts have been measured for a number of chemical compounds utilizing a Varian NMR spectrometer with crossed-coil technique at a fixed radio frequency of 10 Mc. It is suggested that this technique will be a valuable aid, particularly in studying the complex molecular structures of the cobalt carbonyls. The chemical shifts and line widths observed at room temperature for solutions of Co2(CO)8 and for Co4(CO)12 in n-hexane are reported. The ratio of the intensities of the two resonances in CO4(CO)12 is approx. 3:1. This strongly suggests that neither the D2d structure nor intramolecular transformations between three different structures, but the C3v structure originally proposed by Corradini (1) is correct for Co4(CO)12 in both the crystal and solution at room temperature.
Abstraction of Hydrogen from Methanol by Hydroxyl Radical in Subcritical and Supercritical Water

Reactions involving hydrogen abstraction by hydroxyl radical are an important class of reactions in subcritical and supercritical oxidation in water. However, the rates of individual hydrogen abstraction reactions are not available in the literature at the high temperatures and pressures necessary for near-critical or supercritical water oxidation. Here we present the measurements of the hydrogen abstraction from methanol by hydroxyl radical in water at temperatures from ambient to 390 °C and at 250 bar. •OH was generated by pulse radiolysis and the kinetics determined by monitoring the growth of the nitrohydroxycyclohexadienyl radical. The measured bimolecular rate constants show Arrhenius temperature dependence from ambient temperature through the supercritical region. The experimental rate constants for hydrogen abstraction from methanol by hydroxyl radical are significantly higher than the values used by a variety of researchers who have attempted to model oxidation of methanol in supercritical water ...
Smoothness of inertial manifolds

The theory of invariant manifolds plays an important role in the study of dynamics of nonlinear systems in finite dimensional or infinite dimensional spaces. Such invariant manifolds include stable manifolds, unstable manifolds, and center manifolds, see Pliss [36], for example. Recently the theory of inertial manifolds has been developed for some dissipative evolution equations. The inertial manifold introduced by Foias, Sell, and Ttmam [ 141 is a finite dimensional Lipschitz invariant manifold attracting solutions exponentially. One of the important properties of inertial manifolds is that they contain the global attractors. Thus, the study of dynamics of infinite dimensional nonlinear systems can be reduced to the study of dynamics of flows on the inertial manifold, which, in turn, is described by the dynamics of an ordinary differential equation. There are extensive works on this subject. See, for example, Constantin [3], Constantin, Foias, Nicolaenko,
The absence of Verb‐movement and the role of C: Some negative constructions in Shakespeare

The paper lists and discusses all occurrences of an infrequent construction in Shakespearean English, namely one where not precedes (rather than follows) the finite main verb, without the auxiliary do to support the negation. This construction has been neglected or, when it is mentioned, has been left unexplained in traditional grammar. I show that in all these constructions a CP is overtly present. Thus, rather than being an anomaly, the construction provides insight into the clause structure: when a CP is included, an IP is not always present (for the verb to move to across not) and agreement is checked through covert features attraction to C.
On the Self-Energy and the Electromagnetic Field of the Electron

The charge distribution, the electromagnetic field and the self-energy of an electron are investigated. It is found that, as a result of Dirac's positron theory, the charge and the magnetic dipole of the electron are extended over a finite region; the contributions of the spin and of the fluctuations of the radiation field to the self-energy are analyzed, and the reasons that the self-energy is only logarithmically infinite in positron theory are given. It is proved that the latter result holds to every approximation in an expansion of the self-energy in powers of $\frac{{e}^{2}}{\mathrm{hc}}$. The self-energy of charged particles obeying Bose statistics is found to be quadratically divergent. Some evidence is given that the "critical length" of positron theory is as small as $\frac{h}{(\mathrm{mc})}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{exp}(\frac{\ensuremath{-}hc}{{e}^{2}})$.
Pressor Responses to Central Angiotensin II, Prostaglandin E1 and Prostaglandin E2

The effects of ovarian steroids on baseline blood pressure and on changes of mean arterial pressure in response to centrally administered angiotensin II, prostaglandin E1, and prostaglandin E2 were examined. Ovariectomized rats treated with estradiol or progesterone showed no change of resting blood pressures relative to oil-treated, ovariectomized controls. Intracerebroventricular injections of prostaglandin E1, prostaglandin E2 or angiotensin II produced significant elevations of arterial pressure of oil-treated rats. Either estradiol or progesterone treatment significantly attenuated pressor responses to prostaglandin E1 but not to prostaglandin E2 or angiotensin II injections. The duration of the blood pressure increase of estradiol-treated rats in response to angiotensin II was reduced when the animals did not have access to drinking water during the pressure monitoring session but not when water was available. These results’suggest that the effects of ovarian steroids in modulating pressor responses are dependent on the particular factors which initiate the pressure increases. Possible mechanisms underlying this ovarian-steroid action are discussed.
Relativistic positron creation using ultraintense short pulse lasers.

We measure up to $2\ifmmode\times\else\texttimes\fi{}{10}^{10}$ positrons per steradian ejected out the back of $\ensuremath{\sim}\mathrm{mm}$ thick gold targets when illuminated with short ($\ensuremath{\sim}1\text{ }\text{ }\mathrm{ps}$) ultraintense ($\ensuremath{\sim}1\ifmmode\times\else\texttimes\fi{}{10}^{20}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$) laser pulses. Positrons are produced predominately by the Bethe-Heitler process and have an effective temperature of 2--4 MeV, with the distribution peaking at 4--7 MeV. The angular distribution of the positrons is anisotropic. Modeling based on the measurements indicate the positron density to be $\ensuremath{\sim}{10}^{16}\text{ }\text{ }\mathrm{\text{positrons}}/{\mathrm{cm}}^{3}$, the highest ever created in the laboratory.
Characterization of a phenobarbital-inducible dog liver cytochrome P450 structurally related to rat and human enzymes of the P450IIIA (steroid-inducible) gene subfamily.

Abstract A cytochrome P450 called PBD-1 isolated from liver microsomes of an adult male Beagle dog treated with phenobarbital (PB) is structurally and functionally similar to members of the P450IIIA gene subfamily in rat and human liver microsomes. The sequence of the first 28 amino-terminal residues of PBD-1 is identical in 15 and 20 positions, respectively, to the P450IIIA forms P450p from rat and P450NF (and HLp) from human. Upon immunoblot analysis, anti-PBD-1 IgG recognizes PCNa (P450p) and PCNb (PB/PCN-E) from rat, P450NF from human, and two proteins in liver microsomes from both untreated and PB-treated dogs. Similarly, anti-PCNb IgG cross-reacts with PBD-1 and with at least one protein in microsomes from untreated dogs and two proteins in microsomes from PB-treated dogs. P450IIIA-form marker steroid 6β-hydroxylase activities increase 2.5-fold upon PB-treatment of dogs and are selectively inhibited by anti-PBD-1 IgG. NADPH-dependent triacetyloleandomycin (TAO) complex formation and erythromycin demethylase, also marker activities for P450IIIA forms from rats and humans, increase 4- and 5-fold in dog liver microsomes upon PB treatment, whereas immunochemically reactive PBD-1 is induced 3-fold. In microsomes from PB-treated dogs, 5 mg anti-PBD-1 IgG/nmol P450 inhibits greater than 75 and 50% of TAO complex formation and erythromycin demethylase activity, respectively. TAO complex formation is not inhibited by chloramphenicol, a selective inhibitor of the major PB-inducible dog liver cytochrome P450, PBD-2. These data suggest that PBD-1 or another immunochemically related form is responsible for a major portion of macrolide antibiotic metabolism by microsomes from PB-treated dogs and for steroid 6β-hydroxylation by microsomes from both untreated and PB-treated dogs. Major species differences were noted, however, in the apparent Km for 6β-hydroxylation of androstenedione by liver microsomes from untreated rats (24 μ m ), humans (380 μ m ), and untreated dogs (4700 μ m ).
A comparison of the analgetic potency of some analgesics as measured by the “flinch-jump” procedure

The effects of various doses of morphine, dl-methadone, nalorphine, codeine, meperidine and saline on the “flinch-jump” thresholds of rats were measured by a procedure described previously. While none of the drugs influenced the “flinch” threshold, the group slopes of elevation of “jump” thresholds were significant for all drugs studied. In order of potency as revealed by this method, nalorphine ranked with morphine and methadone, while codeine and meperidine were less potent, suggesting that the procedure may be useful as a screening test for analgesic drugs.
Nanostructured photoactive films synthesized by a flame aerosol reactor

A flame aerosol reactor (FLAR) system was used to deposit nanostructured photocatalytic films of titanium dioxide with well controlled morphologies. Nanoparticles were generated in the aerosol phase and then deposited onto a water-cooled substrate via thermophoresis. Two important parameters that influenced film characteristics were the titanium precursor feed rate and substrate temperature, through their effect on particle sintering dynamics on the substrate. The size of the particles as they arrived at the substrate was controlled by varying the titanium precursor feed rate. When the size was below ∼8 nm, sintering was completed in the time available to obtain films with columnar nanostructures. Larger particle sizes resulted in granular, particulate films. The temperature of the substrate was also an important parameter as it controlled the sintering rate and the resultant crystal phase of the film. The thickness of the films was controlled by varying the precursor feed rate and deposition time. The performance of the as-synthesized photocatalytic films was established by measuring the resultant photocurrents. Well sintered columnar morphologies and thicker films (in the range of 40–900 nm) resulted in the largest photocurrents. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Health hazard assessment of chlorinated dioxins and dibenzofurans contained in human milk

Abstract This study examined whether the concentrations of chlorinated dibenzo-p-dioxins and dibenzofurans in human milk and their subsequent intake by the nursing infant may exceed the recommended intake values currently employed by the United States Environmental Protection Agency and the United States Public Health Services Centers for Disease Control. Data was utilized from populations known historically and by isomer-specific analysis of adipose tissue and milk samples to have different levels of exposure to these contaminants. These included northern and southern Vietnam, and the United States. Based on a number of assumptions, these calculations suggested that some nursing infants present in southern Vietnam during and shortly after herbicide spraying, may have consumed, and are continuing to consume, amounts of these contaminants that are greater than currently recommended intake values. Although concentrations of these compounds in samples from the United States are lower, they are still near or greater than the recommended amounts. Analysis of data from northern Vietnam indicate that nursing infants here are exposed to amounts of TCDD equivalents that are below employed standards. However, interpretation of these numbers varies considerably depending on whether the standard from the EPA or CDC is chosen; the latter value for allowable intake being approximately 100-fold higher than the former. Further study is needed to determine if there is any real short- or long-term clinical risk to the nursing infants in these populations.
Two dimensional Yang-Mills theory via stochastic differential equations

Abstract The equation of parallel transport is given meaning in the quantized two dimensional Euclidean Yang-Mills theory by interpreting it as a stochastic differential equation in the complete axial gauge. The expectation of products of Wilson loops is evaluated using the stochastic differential calculus and a method of Bralic. Euclidean invariance of the theory is proven.
Statistical analysis of water-quality data containing multiple detection limits II: S-language software for nonparametric distribution modeling and hypothesis testing

Analysis of low concentrations of trace contaminants in environmental media often results in left-censored data that are below some limit of analytical precision. Interpretation of values becomes complicated when there are multiple detection limits in the data-perhaps as a result of changing analytical precision over time. Parametric and semi-parametric methods, such as maximum likelihood estimation and robust regression on order statistics, can be employed to model distributions of multiply censored data and provide estimates of summary statistics. However, these methods are based on assumptions about the underlying distribution of data. Nonparametric methods provide an alternative that does not require such assumptions. A standard nonparametric method for estimating summary statistics of multiply-censored data is the Kaplan-Meier (K-M) method. This method has seen widespread usage in the medical sciences within a general framework termed ''survival analysis'' where it is employed with right-censored time-to-failure data. However, K-M methods are equally valid for the left-censored data common in the geosciences. Our S-language software provides an analytical framework based on K-M methods that is tailored to the needs of the earth and environmental sciences community. This includes routines for the generation of empirical cumulative distribution functions, prediction or exceedance probabilities, and related confidence limits computation. Additionally, our software contains K-M-based routines for nonparametric hypothesis testing among an unlimited number of grouping variables. A primary characteristic of K-M methods is that they do not perform extrapolation and interpolation. Thus, these routines cannot be used to model statistics beyond the observed data range or when linear interpolation is desired. For such applications, the aforementioned parametric and semi-parametric methods must be used.
Preiser's disease: Identification of two patterns

Abstract Purpose: A large series of patients with Preiser's disease was reviewed to compare 2 potentially different categories of this disorder: complete versus partial vascular impairment of the scaphoid bone as determined by magnetic resonance imaging (MRI). Methods: Nineteen patients with Preiser's disease were identified retrospectively from 2 institutions. Using MRI criteria, 2 disease patterns were identified: diffuse necrosis and/or ischemia of the scaphoid (type 1 disease, 11 cases) and segmental vascular impairment of the scaphoid (type 2 disease, 8 cases). Risk factors for osteonecrosis, treatment methods, and serial radiographs were reviewed in all cases. Sixteen patients were examined for the purpose of this study at an average follow-up of 25 months. Results: MRI signal changes of necrosis and/or ischemia involved 100% of the scaphoid in type 1 cases and on average approximately 42% in type 2 cases (range, 33% to 66%). In type 1 cases, regardless of the treatment used, the scaphoid typically fragmented and collapsed. In type 2 cases, scaphoid architecture was altered minimally after similar treatment methods. A history of wrist trauma was significantly more common in type 2 cases, and the results of treatment were generally better in this group of patients (mean Mayo modified wrist scores, 86 vs 58 points). Conclusions: This study supports the concept of 2 patterns of scaphoid involvement in Preiser's disease. Type 1 cases are characterized by MRI signal changes of necrosis and/or ischemia involving the entire scaphoid bone. Patients in this group have a propensity for scaphoid deterioration. Type 2 cases have MRI signal changes involving only part of the scaphoid. These patients commonly report a history of wrist trauma, show fewer tendencies toward scaphoid fragmentation, and may have a more favorable clinical outcome.
Effective feedback content for tutoring complex skills

Feedback during learning is critical for evaluating new skills. Computer-based tutoring systems have the potential to detect errors and to guide students by providing informative feedback, but few studies have evaluated the real impact of different types of feedback. This article presents results of such a study using the Geometry Tutor for building geometry proofs. It was found that feedback about the goal structure of geometry problems led to better performance than feedback about the reasons for error or than simply being told that an error had occurred. This goal feedback allows students to correct the incorrect action more often than other types of feedback. Also, the goal feedback group continued to deal advantageously with problems when the feedback was subsequently removed. A simulation model, based on Anderson's (1983) ACT* theory and an analogical learning system, presents a preliminary model of the effects of these different feedback types. The model indicates that the advantage of goal-directed feedback is a reflection of its immediate application to the problem, whereas feedback about reasons for the error does not provide any direction to the correct error. According to the model, the feedback allows the student to construct a correct representation of the goal tree involved in various types of proofs more readily than feedback that is not immediately relevant to the current problem.
An adaptive discrete-velocity model for the shallow water equations

A new approach to solving the shallow water equations is presented. This involves using discrete velocities of an adaptive nature in a finite volume context. The origin of the discrete-velocity space and the magnitudes of the discrete-velocities are both spatially and temporally variable. The near-equilibrium flow method of Nadiga and Pullin is used to arrive at a robust second-order (in both space and time) scheme-the adaptive discrete velocity (ADV) scheme-which captures hydraulic jumps with no oscillations. The flow over a two-dimensional ridge, over a wide range of undisturbed upstream Froude numbers prove the robustness and accuracy of the scheme. A comparison of the interaction of two circular vortex patches in the presence of bottom topography as obtained by the ADV scheme and a semi-Lagrangian scheme more than validates the new scheme in two dimensions.
Silver and carbon ink-jet printing to create an amplitude and phase controlled THz metasurface

Controlling the amplitude and phase response of an optical device was once thought to be constrained by the bulk material properties of that device. Demonstrations of metamaterials and metasurfaces have shifted this paradigm. We show that the amplitude and phase of a transmitted THz signal through an array of V-shaped antennas can be controlled by varying the conductivity and geometry of the V-shaped structures. These structures are created using conductive silver and resistive carbon ink deposited by a consumer ink-jet printer.
Autoregression quantiles and related rank score processes for generalized random coefficient autoregressive processes

Abstract Regression quantiles were developed by Koenker and Bassett (Econometrica 46 (1978), 33–50); they provide natural and extremely useful counterparts of the sample quantiles in general linear models. The regression rank scores were introduced by Gutenbrunner and Jureckova (Ann. Statist. 8 (1992), 305–329) as dual variables to regression quantiles. Koul and Saleh (Ann. Statist. 23 (1995), 670–689) developed the procedures based on the regression quantiles of Koenker and Bassett (Econometrica 46 (1978), 33–50) and the regression rank scores of Gutenbrunner and Jureckova Ann. Statist. 8 (1992), 305–329 in linear regression to the pth-order autoregression models. In this paper, we further develop and investigate the analogs of these procedures to a larger class of processes and derive a test for a bilinear model without estimating the bilinear coefficient and the autoregression constants.
The Historical Development of the Content of Consumer Education: An Examination of Selected High School Texts, 1938–1978

This study was designed to determine which topics historically have been most frequently considered to be a part of consumer education and to identify changes over time in the coverage of particular topics. Fifteen selected high school consumer education texts published over a 40-year period were examined and their contents classified into 50 topic categories. Overall, it was found that there was substantial variation among the texts in the topics included and in the length of coverage given to them. While a small group of topics was covered in all of the books, only limited evidence was found for a developing consensus about many other areas. It also appears that the content of consumer education textbooks was relatively unresponsive to economic and social changes over the 40-year period.
Accelerated calendar and pulse life analysis of lithium-ion cells

Abstract Sandia National Laboratories has been studying calendar and pulse discharge life of prototype high-power lithium-ion cells as part of the Advanced Technology Development (ATD) Program. One of the goals of ATD is to establish validated accelerated life test protocols for lithium-ion cells in the hybrid electric vehicle application. In order to accomplish this, aging experiments have been conducted on 18650-size cells containing a chemistry representative of these high-power designs. Loss of power and capacity are accompanied by increasing interfacial impedance at the cathode. These relationships are consistent within a given state-of-charge (SOC) over the range of storage temperatures and times. Inductive models have been used to construct detailed descriptions of the relationships between power fade and aging time and to relate power fade, capacity loss and impedance rise. These models can interpolate among the different experimental conditions and can also describe the error surface when fitting life prediction models to the data.
CS-US temporal relations in blocking.

In four trace-conditioning experiments with rats, the influence on the blocking of differences between the blocking cue–unconditioned stimulus (US) and the blocked cue–US trace intervals was explored. Experiment 1 demonstrated blocking despite the blocked cue’s having a shorter trace interval than the blocking cue in both elemental (Phase 1) and compound (Phase 2) training. In Experiment 2, blocking was attenuated when the blocked cue had a longer trace interval than did the blocking cue in both elemental and compound training. In Experiments 3 and 4, the trace intervals of the two cues during compound training were matched (i.e., unlike in Experiments 1 and 2, neither had temporal priority). Blocking was attenuated when the blocking cue trace interval in the elemental phase was shorter (Experiment 3) or longer (Experiment 4) than the compound cue trace during compound training. The findings indicate that subjects encode interstimulus intervals, and they further suggest that cue competition is greatest when the competing cues have the same temporal information as the US.
What can we learn from dijets? A systematic study at RHIC with VNI/BMS

Abstract We present a systematic study of dijet suppression at RHIC using the VNI/BMS parton cascade. We examine the medium modification of the dijet asymmetry A j and the energy distribution within the dijets (jet-shape). Understanding the sensitivity of these observables to properties of the deconfined medium and to experimental factors is vital if dijets are to be useful for QCD tomography. VNI/BMS provides a controllable test-bed with sufficient complexity to model jet modification without confounding results with fluctuations from hydrodynamics and hadronization. Dijets are examined under the modification of: the jet transport coefficient qhat; the path length of leading and sub-leading jets; jet cone angle and the jet-medium interaction mechanism. We find that A j is very sensitive to the distance traveled by the secondary jet, the jet shape is dominated by qhat and the nature of the interaction mechanism.
Plasma surface interaction experimental facility (PISCES) for materials and edge physics studies

PISCES is a laboratory research facility at UCLA for the study of plasma material interactions in continuous operation at particle and heat fluxes expected in advanced fusion experiments and in reactors. The PISCES plasma has parameters similar to the edge plasma in tokamaks and the halo plasma in tandem mirrors. The 10 cm diameter plasma is generated by a reflex arc discharge from a large area La-Mo disc cathode. The plasma from this H, D, or He discharge transports along the 2–4 kG magnetic field to produce a high density (1013 cm−3), low energy (< 10 eV) plasma. Alternatively, the ions can be extracted and accelerated along the magnetic field by a very low energy acceleration-deceleration system to produce a plasma with 50–500 eV ion energy and a density of about 1012 cm−3. Differential pumping in the baffled chamber and plasma pumping during operation maintain the neutral pressure at about 10 −4 Torr in the target region. Initial operation has produced continuous cold hydrogen plasmas for hours at a time with densities in excess of 1013 cm−3. The three major foci of PISCES experimental work include: materials and coatings behavior under continuous plasma bombardment to high fluence; plasma and neutral gas effects important in the vicinity of the plasma interface with in-vessel components and the gas ducting and pumping systems; and the development, testing, and calibration of gas ducting and pumping systems; and the development, testing, and calibration of diagnostics to be used in long pulse plasma material interaction programs on confinement experiments. The continuous, controllable operation and moderately high heat fluxes (50–125 W/cm2) possible in PISCES permit high fluence investigations on edge plasma physics and materials interactions. Initial plasma operation, experimental investigations, and the capabilities of PISCES will be discussed.
Variability in β-adrenergic receptor response in the vasculature: Role of receptor polymorphism ☆ ☆☆

β-adrenergic receptors (βARs) are important in determining vascular tone. Stimulation of β2ARs in the vasculature produces vasodilatation, which acts to counteract the vasoconstriction produced by endogenous sympathetic agonists. Impaired vasodilatation occurs in human hypertension and in Blacks. It is now clear that receptor polymorphism may contribute to some of the variability seen in vascular response. β2AR haplotypes determine the desensitization response to chronic agonist exposure in vivo and result in altered vasodilatory responses. (J Allergy Clin Immunol 2002;110:S318-21.)
Mitochondrial DNA replication in sea urchin oocytes.

Mitochondrial DNA (mtDNA) replicative intermediates from Strongylocentrotus purpuratus oocytes were isolated by ethidium bromide-CsCl density gradient centrifugation and examined by electron microscopy after formamide spreading. In some experiments, the mtDNA was radioactively labeled by exposing isolated oocytes to [3H]thymidine. Oocyte mtDNA replication appears to follow the displacement loop model outlined in mouse L cells. There are differences in detail. The frequency of D-loop DNA is much lower in oocytes, suggesting that the relative holding time at the D-loop stage is shorter. Duplex synthesis on the displaced strand occurs early and with multiple initiations. The frequency of totally duplex replicative forms, or Cairns' forms, is the highest reported for mtDNA. The differences may be related to the fact that oocyte mtDNA replication occurs in the absence of cell division and need not be coordinated with a cell cycle. Molecules with expanded D loops banded in the intermediate region between the lower and upper bands in an ethidium bromide-CsCl gradient, supporting the notion that displacement replication proceeds on a closed circular template which is subject to nicking-closing cycles. In mature sea urchin eggs, replicative forms are absent and virtually all the mtDNA is stored as clean circular duplexes. Some novel structural variants of superhelical circular DNA (molecules with denaturation loops and double branch-migrated replicative forms) are reported.
Inhibition of Plasmodium sporozoites infection by targeting the host cell

There is a great need of new drugs against malaria because of the increasing spread of parasite resistance against the most commonly used drugs in the field. We found that monensin, a common veterinary antibiotic, has a strong inhibitory effect in Plasmodium berghei and Plasmodium yoelii sporozoites hepatocyte infection in vitro. Infection of host cells by another apicomplexan parasite with a similar mechanism of host cell invasion, Toxoplasma tachyzoites, was also inhibited. Treatment of mice with monensin abrogates liver infection with P. berghei sporozoites in vivo. We also found that at low concentrations monensin inhibits the infection of Plasmodium sporozoites by rendering host cells resistant to infection, rather than having a direct effect on sporozoites. Monensin effect is targeted to the initial stages of parasite invasion of the host cell with little or no effect on development, suggesting that this antibiotic affects an essential host cell component that is required for Plasmodium sporozoite invasion.
New nitrophenyl‐ and nitromethoxyphenyl‐substituted methylpolysiloxane stationary phases for capillary column gas chromatography

Nitrophenyl-, nitrophenylethyl-, dinitrophenylethyl-, and methoxynitrophen- ylethyl-substituted polysiloxanes (25-50% substitution) have been synthesized and evaluated as stationary phases in capillary column gas chromatography. Phases with 25% substitution and with ethylene spacers between the phenyl substituents and the polysiloxane backbone were found to provide high efficiencies, moderate thermal stabilities, and useful selectivities. Without flexible hydrocarbon spacers, the station- ary phases exhibited poor efficiencies. The 50% substituted phases generally provided narrower operational temperature ranges and lower efficiencies, and they were more difficult to immobilize by free radical crosslinking. Several methods of immobilization were evaluated, and a dynamic procedure with dicumylperoxide (DCP) was found to produce the best results for these nitrophenyl-containing phases. The enhancements in polarity resulting from the resonances of the nitrophenyl substituent groups pro- vided unique selectivities for specific applications involving aromatic compounds. The dinitrophenyl-containing phases showed, in addition, selectivity based on charge transfer complex formation.
Web-Based Instruction in Sport Management

Web-based courses are being adopted by academics in higher education, including by sport management instructors. While this adoption has progressed rapidly, there is a definite paucity of research on the effectiveness of Web-based instruction in the discipline of sport management. The purpose of the present study was to describe an online course in sport management that was delivered in the spring semester of 2001. Comparisons are made with another section of the same class that was taught using the conventional lecture format. Mixed methods, including a questionnaire, student assessments, and an instructor's log were used to report the findings of this particular research endeavour. Research conducted by Bennett, Henson, and Connaughton (2001) served as a framework for this particular inquiry. Bennett et al. (2001) surveyed one Web-based class and found participants were extremely pleased with their Web-based learning experience. Results from the present study indicated both similar outcomes and additional findings regarding student learning. For example, these students reported optimal satisfaction with their experience in the Webbased class, including the interaction that they received from the instructor of the class and the convenience of taking a class via the Internet. The results also indicated that these participants compared their experience in the online class quite favourably with their experiences in conventional courses. Additional noteworthy findings focused on student learning in the Web-based environment. When compared with the conventional sport management class, the Web-based students scored equally well on quizzes and examinations. Respondents also reported negative experiences with the Web-based quizzes and the lack of social interaction with class peers.
Dynamic power-performance adaptation of parallel computation on chip multiprocessors

Previous proposals for power-aware thread-level parallelism on chip multiprocessors (CMPs) mostly focus on multiprogrammed workloads. Nonetheless, parallel computation of a single application is critical in light of the expanding performance demands of important future workloads. This work addresses the problem of dynamically optimizing power consumption of a parallel application that executes on a many-core CMP under a given performance constraint. The optimization space is two-dimensional, allowing changes in the number of active processors and applying dynamic voltage/frequency scaling. We demonstrate that the particular optimum operating point depends nontrivially on the power-performance characteristics of the CMP, the application's behavior, and the particular performance target. We present simple, low-overhead heuristics for dynamic optimization that significantly cut down on the search effort along both dimensions of the optimization space. In our evaluation of several parallel applications with different performance targets, these heuristics quickly lock on a configuration that yields optimal power savings in virtually all cases.
Circleator: flexible circular visualization of genome-associated data with BioPerl and SVG.

Summary: Circleator is a Perl application that generates circular figures of genome-associated data. It leverages BioPerl to support standard annotation and sequence file formats and produces publication-quality SVG output. It is designed to be both flexible and easy to use. It includes a library of circular track types and predefined configuration files for common use-cases, including. (i) visualizing gene annotation and DNA sequence data from a GenBank flat file, (ii) displaying patterns of gene conservation in related microbial strains, (iii) showing Single Nucleotide Polymorphisms (SNPs) and indels relative to a reference genome and gene set and (iv) viewing RNA-Seq plots.
A Parametric Study of the Modified Model Reference Adaptive Control Scheme

The validity of the claim by many studies that the damping and stiffness forces can be ignored when designing a model reference adaptive controller, is examined. For a simple plant, the sensitivity of the closed loop system to the inertial, damping, and stiffness nonlinearities are investigated, through a simulation analysis. It is shown that the closed loop system is sensitive to the changes in the inertial nonlinearities, and relatively insensitive to variations in the damping and stiffness forces. This supports the assumption made in many previous studies.
Recent progress in Cr/sup 4+/ lasers

Summary form only given. This talk first reviews recent results in cw and femtosecond performance of the Cr:forsterite and Cr:YAG lasers. Limitations on the performance of these lasers in terms of excited-state absorption and thermally enhanced nonradiative decay are emphasized. New hosts such as montecellite, YSO, and the scandium garnets are discussed. Diode-pumping experiments are reviewed, and possible reasons why diode pumping has not (yet) been successful are proposed. New laser architectures such as waveguide lasers based on composites of Cr:forsterite nanocrystals in a refractive-index-matched host are described.
On the Equilibrium Spectrum of Transient Waves in the Atmosphere

The spectrum of transient heat flux in the midlatitude troposphere has a maximum at a synoptic scale. The same is true of the transient energy. The wavenumber of these maxima can be explained by the theory of nonlinear baroclinic adjustment, which is also shown to predict the shape of the spectra. According to this theory, each zonal wave has a nonlinear threshold that bounds its growth, and the bounds are larger for longer waves. The most unstable wave grows and transports heat until it reaches its threshold, at which point it breaks and saturates, passing off excess energy to the next longer wave. The process repeats, with energy cascading upscale, until the total heat transport is sufficient to reduce the meridional temperature gradient down to a relatively constant equilibrium level, independent of forcing. Thus at higher forcings more heat must be transported and the cascade extends to longer scales. At equilibrium, the longest heat-transporting wave has not saturated but rather has been rendered linearly neutral by the reduction in the temperature gradient. Observations from the real atmosphere, and computations with a quasigeostrophic two-level model in a betaplane channel, corroborate the theory presented.
Measurement of oxidatively induced DNA damage and its repair, by mass spectrometric techniques

AbstractOxidatively induced damage caused by free radicals and other DNA-damaging agents generate a plethora of products in the DNA of living organisms. There is mounting evidence for the involvement of this type of damage in the etiology of numerous diseases including carcinogenesis. For a thorough understanding of the mechanisms, cellular repair, and biological consequences of DNA damage, accurate measurement of resulting products must be achieved. There are various analytical techniques, with their own advantages and drawbacks, which can be used for this purpose. Mass spectrometric techniques with isotope dilution, which include gas chromatography (GC) and liquid chromatography (LC), provide structural elucidation of products and ascertain accurate quantification, which are absolutely necessary for reliable measurement. Both gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS), in single or tandem versions, have been used for the measurement of numerous DNA pr...
Experimental investigation of Si IGBT short circuit capability at 200°C

This paper investigates the short-circuit capability and the failure mechanisms of Si trench gate field-stop IGBT under high temperature operation conditions through experiments. First, the test circuits are proposed for IGBT short circuit capability evaluation in different types of short circuit conditions. A hardware setup is built accordingly, and used to evaluate experimentally the IGBT short circuit failures caused by thermal destruction, thermal runaway and latch-up at both 25°C and 200°C. The critical short circuit time is given for high temperature operation under different short circuit conditions. The experimental results show that although the critical short circuit time is reduced at 200°C operation, it is still adequate for the protection circuit to shut down the devices safely. The Si trench gate field-stop IGBT exhibits good short circuit ruggedness at 200°C operation.
Reaction and Deactivation Pathways in Xylene Isomerization on Zirconia Modified by Tungsten Oxide

The effect of H2 on isomerization pathways and on the acid site density on WOx-ZrO2 catalysts was explored using kinetic measurements of acid-catalyzed o-xylene isomerization reactions. Initial o-xylene isomerization rates on WOx-ZrO2 at 523 K are proportional to the H2 concentration even though H atoms are not involved directly in reaction turnovers, as shown by the low deuterium content in the isomers formed from D2/o‐C8H10 mixtures. H2 chemisorption uptakes on WOx-ZrO2 and isomerization rates show a similar dependence on WOx surface density and structure, suggesting that Bronsted acid sites form via reductive processes that require H atoms from H2. This proposal is consistent with UV-visible spectra, which show the formation of reduced centers by H2; these centers correspond to the formation of acidic H ‐C species with charge compensation by WO ‐i 3 domains. The transients induced by the addition and removal of H2 (or O2) during xylene isomerization show that the formation of acid sites by H2 is reversible at reaction conditions and that H2 is involved in maintaining a steady-state density of acid sites. H2 also inhibits catalyst deactivation, apparently by reversing C‐H bond activation steps leading to the formation of strongly adsorbed unsaturated hydrocarbons. A sequence of elementary steps including isomerization, deactivation, and acid site formation pathways was found to describe accurately the observed effects of H2 and o-xylene on deactivation, reaction rates, and the results of o- 13 C8H10/o-C8H10 and D2/o-C8H10 exchange experiments. c ∞ 2000 Academic Press