cssi/SciSciGPT-SciSciNet huggingface dataset:
The retentive capacity of rebonded retainers to enamel

Twenty-one whole, extracted canines and castings that had been bonded and tested to failure in a previous study were used as samples for this study.’ The designs that were retested had been previously illustrated.’ The teeth had been mounted in improved dental stone (Velmix, Kerr Manufacturing Co., Romulus, Mich.) in copper tubing 1% inches in diameter and 11% inches high. Linden2 reported’that fluid diffuses from the pulp through the dentin and enamel in vitro. To provide for similar hydration of the sample teeth, each root apex was removed and a hole through the mounting stone allowed storage water to penetrate the pulp chamber. The samples were stored in distilled water containing thymol, as suggested by Silverstone.’ After 1 year of storage, the residual composite resin was removed from the lingual surface of the tooth with a 12-bladed carbide finishing bur. The surface was then polished with oil-free pumice and examined visually to determine if all the composite resin had been removed. The castings (Fig. 1) were cleaned with a hand chisel, a high-speed composite resin finishing bur, and an air brush (Paasche Air Brush Co., Chicago, Ill.). The teeth were returned to the distilled water/thymol solution for an additional 6 months. For rebonding, the teeth were cleaped with oil-free pumice, rinsed in tap water, and dried with a commercial hair dryer (Sears, Roebuck & Co., Chicago, Ill.). The lingual surface was etched for 1 minute with 35% phosphoric acid (Adaptic, Johnson and Johnson, East Windsor, N. J.), as recommended by the manufacturer,
Associations of health risk factors and chronic illnesses with life dissatisfaction among U.S. adults: the Behavioral Risk Factor Surveillance System, 2006.

Abstract Objective To estimate the prevalence of life dissatisfaction and assess its associations with health risk factors and chronic illnesses in adults. Methods Data from the Behavioral Risk Factor Surveillance System in 2006 (n = 341,140) were analyzed. Odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated using logistic regression analyses. Results The prevalence of life dissatisfaction was estimated to be 5.0% among adults. People with one, two, and three health risk factors were, respectively, 2.2 (95% CI: 2.0–2.5), 3.7 (95% CI: 3.2–4.2), and 5.8 (95% CI: 4.6–7.4) times more likely to report life dissatisfaction than those without (P Conclusions Clustering of health risk factors or chronic illnesses was associated with life dissatisfaction independently of self-rated health and other established correlates.
Optical Techniques For In-Situ, Real-Time Detection Of Laser-Induced Damage

We are building an optical laboratory in which three complementary optical techniques: Raman scattering, sur-face second harmonic generation and photoluminescence, will be used to observe in-situ, in real-time the cumulative structural changes that occur during repeated illumination of solid surfaces. Such changes may be beneficial as in sem-iconductor processing but in general are detrimental, as in laser-induced damage of optical components. The evolution of stress, crystallinity, surface electronic properties and of the type and number of defects will be correlated with the appearance of damage spots during illumination sequences with below threshold pulses. From this, the mechanisms of multiple pulse damage will emerge and prediction of failure in components will become possible.
Tissue Culture as a Hostile Environment: Identifying Conditions for Breast Cancer Progression Studies

The cell culture environment (substrate, atmosphere, and medium) can have a significant influence on the characteristics of cells that propagate from clinical samples. In this issue of Cancer Cell, Ince and colleagues report improved conditions for the culture of primary human breast epithelial cells. They demonstrate that, when cells cultured using the new conditions are experimentally transformed, they are more tumorigenic, form tumor xenografts that closely resemble human breast ductal adenocarcinoma, and are more metastatic compared to cells cultured under standard conditions similarly transformed. This suggests that pre-existing differences in cell culture can modulate the tumor phenotype.
In situ formation of three-dimensional TiC reinforcements in Ti-TiC composites

Three-dimensional, single-crystal reinforcements of TiC were producedin situ during manufacture of Ti-TiC composites. The composites, containing 40 to 50 vol pct TiC, were produced using standard casting procedures. The presence of aluminum in Ti-TiC composites showed enhanced strength without loss of ductility at room and elevated temperatures. Aluminum additions were found to solid solution strengthen the Ti matrix and increase the strength of the TiC phase. The morphology of the TiC, which was controlled by processing parameters, influenced the properties of the Ti-TiC composites investigated. Refinement of the secondary dendrite arm spacing of the three-dimensional (3-D) TiC particles was found to dramatically improve the ultimate tensile strength (UTS) and ductility of the Ti-TiC composites.
Context‐oriented instructional design for course transformation

Colleagues from Virginia Tech and Mzuzu University personnel worked together to redesign an online master's degree program to fit Malawi's needs.
Effective incentives for domestic market sales and exports

This paper develops and employs an estimating procedure to measure the net effect of economic policies in providing incentives for domestic market production and sales, as reflected through observed price divergences. Employing direct comparisons of international and domestic prices over a wide range of products, estimates are made for Brazil of implicit tariffs, implicit nominal protection and effective protection for domestic market sales. While the welfare costs of protection are substantial, the observed structure of effective protection is seen to favor those industries where there is still some scope for further import substitution. The available evidence also suggests that Brazilian trade policies protect physical and human capital to the detriment of those activities providing the greatest usee of unskilled labor. Using the same effective incentives estimating framework, estimates are made of effective rates of export promotion. It is seen that in many instances the discrimination against exports imposed in the form of anti-export biases through the constellation of commercial policies is considerable.
Cotranslational disassembly of a cowpea strain (Cc) of TMV: evidence that viral RNA-protein interactions at the assembly origin block ribosome translocation in vitro.

Abstract Cotranslational disassembly of mixed rod-length populations of tobacco mosaic virus (TMV; vulgare, common or, U1 strain), reveals a reproducible, significant reduction in the level of expression of the intermediate-sized, subgenomic 12-RNA when compared with conventional total viral RNA preparations. I2-RNA encodes a 30-kDa protein, and recent evidence suggests that I2-RNA is unusual in that it lacks a 5′-cap structure. In TMV vulgare, the assembly origin is located within the 30-kDa protein-coding region. To resolve which of these structural features might be responsible for the decline in 30-kDa gene expression from packaged 12-RNAs, the products encoded in vitro by packaged or naked genomic and subgenomic RNAs from two strains of TMV, vulgare and a cowpea strain (Cc or Sunn-hemp mosaic virus), were compared. The results indicate that strong coat protein-RNA interactions, presumed to occur at the assembly origin, dictate the site at which translocation of 80 S ribosomes is inhibited. The implications of this conclusion for virus infection in vivo are discussed.
Aequorin-expressing mammalian cell lines used to report Ca2+ mobilization

Mammalian cells that stably express jellyfish aequorin have been used to report activation of Ca2+ mobilization by cell-surface receptors. Expression of aequorin cDNA (pAEQ) was driven by the cytomegalovirus (CMV) promoter in CHO-K1 and 293 cells. Clonal isolates were obtained which express high levels of apo-aequorin protein, the Ca(2+)-dependent luminescence of which is generated by treatment of living cells with the coelenterate luciferin, coelenterazine. Transient expression of aequorin in COS cells results in even greater abundance of luminescent protein. Aequorin protein is lost from digitonin-permeabilized cells to the same extent and at the same rate as lactate dehydrogenase (LDH), indicating cytosolic location of the indicator. Aequorin expressing cells treated with agonists of endogenous receptors were used in luminescence measurements to demonstrate that the reporter lines offer a highly sensitive and robust means of assaying changes in the concentration of cytosolic Ca2+ ion. Transient co-expression of the substance P receptor in aequorin reporter cells was also performed to demonstrate the feasibility of using this convenient and sensitive assay system for large scale screening of ligands that activate cell surface receptors coupled to increases in intracellular Ca2+.
Variations on Invariance or Some Unpleasant Nonparametric Arithmetic: Comment

Chalfant and Zhang (CZ) have recently discussed in this journal the issue of invariance of some nonparametric results in production and consumption analysis. The invariance is related to the fact that some nonparametric results depend on the scaling of prices and quantities. CZ see this as an "unpleasant" drawback of the corresponding nonparametric approaches. Also, they claim that they found a solution that "solves the invariance problem" (Chalfant and Zhang, p. 1164). This comment has two objectives. First, it shows that the invariance problem is a generic problem that is not specific to nonparametric analysis. As such, it seems inappropriate to associate the "unpleasant invariance" problem with some nonparametric methods. Second, while CZ are correct in pointing out the "invariance problem," contrary to their claim, they did not solve it.
Constructing phantom heads for radiation research.

Abstract We have described the construction of a phantom head which consisted of a human skull encased in a plastic “skin” made in the shape of the human head. Soft tissue was simulated effectively when the plastic head-shaped container was filled with water. Plastic foam was used to exclude the water from the passages that, in the head, normally are filled with air. Phantoms of this type are ideally suited for many types of investigation of the x-radiation used in dentistry.
Misreporting of Total Energy Intake in Older Men and Women

Misreporting of total energy intake occurs frequently in dietary studies. Relatively few studies have been performed in older individuals who may be vulnerable to obesity and its associated health risks. In the present study, we examined misreporting of total energy intake by comparing self-reported food intake, measured by 3-day food diaries, to energy expenditure, measured with the doubly labeled water technique, in a relatively large sample of older men (n = 39) and women (n = 43). An additional objective was to identify potential predictors of misreporting, including body composition, fitness as assessed by peak VO2, and sociodemographic characteristics such as gender, living arrangement, education, and income. In general, men and women underreported total energy intake. The magnitude of the underreporting, as measured by percent difference between reported intake and measured total energy expenditure, was comparable between the sexes. Body mass index, waist circumference, and fat mass were significant correlates of underreporting of total energy intake, with heavier individuals underreporting more than leaner individuals. Among the demographic variables, living arrangement was a significant determinant of misreporting of total energy intake in older people. Individuals in marriage-like living arrangements underreported their total energy intake to a greater extent than married individuals. However, the magnitude of misreporting by those living alone did not differ from that of married individuals. The results of the present study highlight the need to examine misreporting of total energy intake in older individuals, who are more prone to obesity and its health risks.
Tumour promotor induces plasminogen activator

INFECTION of chick embryo fibroblasts with Rous sarcoma virus (RSV) induces a cell-specified plasminogen activator1. Induction occurs with transforming viruses but not with lytic viruses or with oncornaviruses which are not themselves transforming2. Similarly, many mammalian cell lines and embryo cultures transformed with either viruses or chemical carcinogens may be high producers of plasminogen activator in contrast to their untransformed counterparts3–6. A correlation has been demonstrated between production of plasminogen activator and various features of the transformed phenotype, such as cell locomotion, morphology and loss of anchorage-dependent growth4,7. Several established cell lines which are not highly tumorigenic or transformed by the usual criteria are, however, active producers of plasminogen activator; there are examples also of transformed or tumorigenic cell lines which do not produce significant levels of plasminogen activator3,8–10.
Integrated circuit interfaces between nuclear instrument module and emitter coupled logic levels

Abstract Two simple high-speed interfaces using integrated circuits are described. They provide conversion between nuclear instrument module and emitter coupled logic levels. Rise times and fall times are
Mineral Distributions in Milling Fractions of Low Phytic Acid Wheat

Low phytic acid (LPA) wheat (Triticum aestivum L.) is one approach to improving nutritional quality of wheat by reducing the major storage form of P and increasing the level of inorganic P (Pi), which is more readily absorbed by humans and other monogastric animals. A LPA mutant of wheat, designated Js-12-LPAwas isolated following mutagenesis. LPA and wild-type (WT) sib selections of hard red spring wheat families with the pedigree ‘Grandin’*4/Js-12-LPA were grown in replicated field trials in 2003 and 2004. Grain was milled on an experimental mill, and the distribution of P, phytic acid P (PAP), and Pi was measured in milling fractions. Mineral concentrations also were determined. LPA selections had elevated concentrations of Pi and Mg in flour fractions. The concentration of Pi in LPA flour was three times the concentration in WT flour, and Mg concentration in LPA flour was 25% greater than in WT flour. Therefore, P and Mg in LPAwheat appear to be redistributed within the kernel. The increase in Pi is similar to that observed for other LPA mutants and should improve the mineral nutrition of monogastric animals fed whole grain LPA wheat. As most wheat is milled for flour and bran, the detailed distribution of minerals in the LPAwheat should assist geneticists and nutritionists in assessing the value of this mutation.
Highly active surfaces for CO oxidation on Rh, Pd, and Pt

Studies show that the rate of CO oxidation on Pt-group metals at temperatures between 450 and 600 K and pressures between 1 and 300 Torr increases markedly with an increase in the O2/CO ratio above 0.5. The catalytic surfaces, formed at discrete O2/CO ratios >0.5, exhibit rates 2–3 orders of magnitude greater than those rates observed for stoichiometric reaction conditions and similar reactant pressures or previously in ultrahigh vacuum studies at any reactant conditions and extrapolate to the collision limit of CO in the absence of mass transfer limitations. The O2/CO ratios required to achieve these so-called ‘‘hyperactive’’ states (where the reaction probabilities of CO are thought to approach unity) for Rh, Pd, and Pt relate directly to the adsorption energies of oxygen, the heats of formation of the bulk oxides, and the metal particle sizes. Auger spectroscopy and X-ray photoemission spectroscopy reveal that the hyperactive surfaces consist of approximate 1 ML of surface oxygen. In situ polarization modulation reflectance absorption infrared spectroscopy measurements coupled with no detectable adsorbed CO. In contrast, under stoichiometric O2/CO conditions and similar temperatures and pressures, Rh, Pd, and Pt are essentially saturated with chemisorbed CO and exhibit far less activity for CO oxidation. � 2007 Elsevier B.V. All rights reserved.
CaNAT1, a Heterologous Dominant Selectable Marker for Transformation of Candida albicans and Other Pathogenic Candida Species

A dominant selectable marker for Candida albicans and other Candida species, which confers resistance to nourseothricin, was characterized. In a heterologous promoter system and a recyclable cassette, the marker efficiently permitted deletion and complementation of C. albicans genes. Neither growth nor filamentous development was affected in strains expressing this marker.
The Distributional Effects of Minority-Protective Judicial Review

Constitutional theorists usually assume that minority-protective judicial review leads to outcomes more favorable to the protected minority and less favorable to the majority. Our analysis highlights three e ects of judicial review that complicate, and sometimes undermine, this conventional wisdom. First, judicial review can induce a shift from a separating equilibrium|in which pro-majority leaders and pro-minority leaders pursue di erent policies|to a semiseparating or pooling equilibrium in which pro-minority leaders sometimes mimic pro-majority leaders by adopting the most antiminority policy that the judiciary would uphold. Second, if judicial validation of anti-minority policies is probabilistic rather than certain, pro-majority leaders may propose even more extreme anti-minority policies in order to deter pro-minority leaders from mimicking. Third, if voters cannot directly observe policy outcomes, then minority-protective judicial review may create incentives for a leader to signal (or conceal) her type by provoking judicial reversal. These e ects can sometimes nullify, or even reverse, the assumed relationship between minority-protective judicial review and pro-minority outcomes. When such reversal occurs, majoritarian democrats should favor minority-protective judicial review, while those concerned with protecting unpopular minorities should oppose it.
Antioxidant Diet Protects Against Emphysema, but Increases Mortality in Cigarette Smoke-Exposed Mice

Oxidative stress plays an important role in cigarette smoke-induced lung inflammation and emphysema. We produced an enriched diet by adding freeze-dried fruits and vegetables and additional supplements to the 8604 Teklad Rodent Diet, a standard rodent diet. In this study, we examined the effects of the antioxidant-enriched diet on cigarette smoke-induced lung inflammation and emphysema. CH3/HeN mice were fed either a regular diet or the supplemented diet. These mice were exposed to filtered air, a low concentration of cigarette smoke (total particulate matter: 100 mg/m3) or a high concentration of cigarette smoke (total particulate matter: 250 mg/m3) for 6 h/day, 5 days/week for total 16 weeks. Surprisingly, increased mortality (53%) was observed in the high concentration of cigarette smoke-exposed mice fed the antioxidant diet compared to the high concentration of cigarette smoke-exposed mice that were fed a regular diet (13%). The necropsy analysis revealed nasal passage obstruction due to mucous plugging in cigarette smoke-exposed mice on the antioxidant diet. However, the antioxidant diet significantly reduced neutrophilic inflammation and emphysema in the high concentration of cigarette smoke-exposed mice as compared to the regular diet /high concentration of cigarette smoke controls. The antioxidant capacity in the bronchoalveolar fluid or oxidative damage to the lung tissue was not affected by the antioxidant diet. Pro-MMP-2, MMP-2, and MMP-9 activity did not correlate with the protective effects of AOD on cigarette smoke-induced emphysema. These data suggest that the antioxidant diet reduced cigarette smoke-induced inflammation and emphysema, but increased mortality in the obligate nose-breathing mice.
FTIR spectroscopic measurement of halogenated compounds produced during fire suppression tests of two halon replacements

Abstract During full-scale fire suppression tests using HFC-227ea and HCFC Blend A, the Fourier transform infrared spectroscopic method was used to monitor the gas composition of the air in a 121 m 3 test compartment. These agents were observed to produce halogenated compounds during the tests. The production of the halogenated gas compounds depended on the type and concentration of the agents and on the size and extinguishment time of the test fires. Quantitative analysis of infrared spectra indicated that the concentrations of the halogenated compounds were at dangerous levels during suppression. Safety measures should be taken to prevent persons from being exposed to these toxic gas compounds and to minimize potential corrosion damage to equipment.
Anisotropy of gain in nanowire lasers

We investigate the polarization properties of wurtzite GaN nanowire-based lasers. In particular, we emphasize the different orientations of the polarization of the lowest transitions in thick and thin nanowires.
Detecting Climate Signals Using Space–Time EOFs

Estimates of the amplitudes of the forced responses of the surface temperature field over the last century are provided by a signal processing scheme utilizing space‐time empirical orthogonal functions for several combinations of station sites and record intervals taken from the last century. These century-long signal fingerprints come mainly from energy balance model calculations, which are shown to be very close to smoothed ensemble average runs from a coupled ocean‐atmosphere model (Hadley Centre Model). The space‐ time lagged covariance matrices of natural variability come from 100-yr control runs from several well-known coupled ocean‐atmosphere models as well as a 10 000-yr run from the stochastic energy balance climate model (EBCM). Evidence is found for robust, but weaker than expected signals from the greenhouse [amplitude ;65% of that expected for a rather insensitive model (EBCM: 2.38C)], volcanic (also about 65% DT23CO2 expected amplitude), and even the 11-yr component of the solar signal (a most probable value of about 2.0 times that expected). In the analysis the anthropogenic aerosol signal is weak and the null hypothesis for this signal can only be rejected in a few sampling configurations involving the last 50 yr of the record. During the last 50 yr the full strength value (1.0) also lies within the 90% confidence interval. Some amplitude estimation results based upon the (temporally smoothed) Hadley fingerprints are included and the results are indistinguishable from those based on the EBCM. In addition, a geometrical derivation of the multiple regression formula from the filter point of view is provided, which shows how the signals ‘‘not of interest’’ are removed from the data stream in the estimation process. The criteria for truncating the EOF sequence are somewhat different from earlier analyses in that the amount of the signal variance accounted for at a given level of truncation is explicitly taken into account.
Endoscopic pancreatic cystogastrostomy using the Nd:YAG laser

The rapid development of noninvasive diagnostic imaging methods during the past 10 years has improved our ability to detect pancreatic pseudocysts and has allowed for better definition of their natural history.l,2 As many as 40% of the acute pseudocysts may regress spontaneously within the first 4 to 6 weeks after detection2,3; those that do not regress have a high incidence of significant complications2 and, thus, require intervention. However, considerable controversy still exists about the proper surgical management of pseudocysts. All the standard approaches carry a significant risk of morbidity and mortality, especially when performed early in the development of the pseudocyst. ,4-6 New methods of management are being applied with variable success. These include percutaneous aspiration,7.8 percutaneous drainage,9 and endoscopic drainage using electrocautery4,lO,l1 or the argon laserY This report describes the successful endoscopic use of the Nd:YAG laser to decompress two acute, symptomatic, pancreatic pseudocysts.
A case of artifactual rebreathing

Abstract This case report describes artifactual rebreathing due to a defect in a capnometer tubing and examines some common etiologies of true rebreathing.
Rescaled-range and power spectrum analyses on well-logging data

SUMMARY Fractal theory and related developments have significantly enlightened our understanding of many natural phenomena and led to an upsurge in research efforts in many different disciplines. This has unfortunately caused some ambiguities, misunderstandings, and even misuses in the published literature concerning some new concepts in fractal theory and their actual implementations. As new applications and ideas arise almost daily, it is important to present the methods in a common framework to minimize further confusion. In this paper, we scrutinize and compare two of the most frequently applied methods for characterizing fractal time-series, namely the rescaled-range (R/S) and the power spectrum method, and describe their proper applications in wire line well-logging data. We outline the problems related to applications of these two methods. Based on numerical analysis on fractional Gaussian noise (fGn) and fractional Brownian motion (fBm), we demonstrate the clear necessity to distinguish between fGn-like and fBm-like data series. For fBm-like data series, the use of their successive increments is proposed against using various other alternatives in R/S analysis in order to make the estimated Hurst exponent (Hu) comparable with the global scaling exponent (H) from power spectrum analysis. We argue that well-logging data are generally analogous to fBm, and thus we use their incremental series rather than raw well data themselves to estimate Hu when applying R/S. We also reveal a connection between the transient zone length in the R/S technique and the shortest-wavelength that can be included for a linear regression in the power spectrum method.
Electron-positron annihilation: Statistical and thermodynamic considerations

Abstract Lightcone considerations suggest that, in e+e− annihilation, the hadronic matter is initially created within a spatial volume in the c.m. frame of the order of E−3, where E 2 is the colliding beam energy. Its implications, within the statistical thermodynamic descriptions of Fermi and Landau, are conjectured. A distinctive result is that the multiplicity for e+e− annihilation is a constant.
Complications of donor apheresis

A decreasing blood donor pool in the presence of increasing blood transfusion demands has resulted in the need to maximally utilize each blood donor. This has led to a trend in the increasing use of automated blood collections. While apheresis donation shares many reactions and injuries with whole blood donation, because of the differences, unique complications also exist. Overall, evidence in the literature suggests that the frequency of reactions to apheresis donation is less than that seen in whole blood donation, though the risk of reactions requiring hospitalization is substantially greater. The most common apheresis-specific reaction is hypocalcemia due to citrate anticoagulation, which, while usually mild, has the potential for severely injuring the donor. Other reactions to apheresis donation are uncommon (e.g., hypotension) or rare (e.g., air embolism). More worrisome, and in need of additional study, are the long-term effects of apheresis donation. Recent evidence suggests that repeated apheresis platelet donations may adversely effect thrombopoiesis as well as bone mineralization. Granulocyte donation has also been implicated in unexpected long-term consequences.
Simulation modeling and optimization using ProModel

The ProModel Optimization Suite is a powerful yet easy-to-use simulation tool for modeling all types of manufacturing systems ranging from small job shops and machining cells to large mass production, flexible manufacturing systems, and supply chain systems. ProModel is a Windows based application with an intuitive graphical interface and object-oriented modeling constructs that eliminate the need for programming. It combines the flexibility of a general-purpose simulation language with the convenience of a data-driven simulator. The ProModel Optimization Suite includes an optimization tool called SimRunner that performs sophisticated "what-if" analysis by running automatic factorial design of experiments on the model, providing the best answer possible. This paper provides an overview of the ProModel Optimization Suite and presents its modeling, analysis, and optimization capabilities.
Declarative symbolic pure-logic model checking

Model checking, a technique for findings errors in systems, involves building a formal model that describes possible system behaviors and correctness conditions, and using a tool to search for model behaviors violating correctness properties. Existing model checkers are well-suited for analyzing control-intensive algorithms (e.g. network protocols with simple node state). Many important analyses, however, fall outside the capabilities of existing model checkers. Examples include checking algorithms with complex state, distributed algorithms over all network topologies, and highly declarative models. This thesis addresses the problem of building an efficient model checker that overcomes these limitations. The work builds on Alloy, a relational modeling language. Previous work has defined the language and shown that it can be analyzed by translation to SAT. The primary contributions of this thesis include: a modeling paradigm for describing complex structures in Alloy; significant improvements in scalability of the analyzer; and improvements in usability of the analyzer via addition of a debugger for overconstraints. Together, these changes make model-checking practical for important new classes of analyses. While the work was done in the context of Alloy, some techniques generalize to other verification tools. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
Effects of slight anisotropy on surface waves

SUMMARY We present a complete ray theory for the calculation of surface-wave observables from anisotropic phase-velocity maps. Starting with the surface-wave dispersion relation in an anisotropic earth model, we derive practical dynamical ray-tracing equations. These equations allow calculation of the observables phase, arrival angle and amplitude in a ray theoretical framework. Using perturbation theory, we also obtain approximate expressions for these observables. We assess the accuracy of the first-order approximations by using both theories to make predictions on a sample anisotropic phasevelocity map. A comparison of the two methods illustrates the size and type of errors which are introduced by perturbation theory. Perturbation theory phase and arrivalangle predictions agree well with the exact calculation, but amplitude predictions are poor. Many previous studies have modelled surface-wave propagation using only isotropic structure, not allowing for anisotropy. We present hypothetical examples to simulate isotropic modelling of surface waves which pass through anisotropic material. Synthetic data sets of phase and arrival angle are produced by ray tracing with exact ray theory on anisotropic phase-velocity maps. The isotropic models obtained by inverting synthetic anisotropic phase data sets produce deceptively high variance reductions because the eVects of anisotropy are mapped into short-wavelength isotropic structure. Inversion of synthetic arrival-angle data sets for isotropic models results in poor variance reductions and poor recovery of the isotropic part of the anisotropic input map. Therefore, successful anisotropic phase-velocity inversions of real data require the inclusion of both phase and arrival-angle measurements.
Explaining how brain stimulation can evoke memories

An unexplained phenomenon in neuroscience is the discovery that electrical stimulation in temporal neocortex can cause neurosurgical patients to spontaneously experience memory retrieval. Here we provide the first detailed examination of the neural basis of stimulation-induced memory retrieval by probing brain activity in a patient who reliably recalled memories of his high school (HS) after stimulation at a site in his left temporal lobe. After stimulation, this patient performed a customized memory task in which he was prompted to retrieve information from HS and non-HS topics. At the one site where stimulation evoked HS memories, remembering HS information caused a distinctive pattern of neural activity compared with retrieving non-HS information. Together, these findings suggest that the patient had a cluster of neurons in his temporal lobe that help represent the "high school-ness" of the current cognitive state. We believe that stimulation here evoked HS memories because it altered local neural activity in a way that partially mimicked the normal brain state for HS memories. More broadly, our findings suggest that brain stimulation can evoke memories by recreating neural patterns from normal cognition.
Embarrassingly parallel jobs are not embarrassingly easy to schedule on the grid

Embarrassingly parallel applications represent an important workload in today's grid environments. Scheduling and execution of this class of applications is considered mostly a trivial and well-understood process on homogeneous clusters. However, while grid environments provide the necessary computational resources, associated resource heterogeneity represents a new challenge for efficient task execution for these types of applications across multiple resources. This paper presents a set of examples illustrating how execution characteristics of individual tasks, and consequently a job, are affected by the choice of task execution resources, task invocation parameters, and task input data attributes. It is the aim of this work to highlight this relationship between an application and an execution resource to promote development of better metascheduling techniques for the grid. By exploiting this relationship, application throughput can be maximized, also resulting in higher resource utilization. In order to achieve such benefits, a set of job scheduling and execution concerns is derived leading toward a computational pipeline for scheduling embarrassingly parallel applications in grid environments.
Fluid‐Borne entities in the impeller stream of a rushton turbine

The breakage or disintegration of suspended entities by energetic fluid motions in stirred tanks is an essential aspect of many operations in the chemical process industries. However, the hydrodynamic inhomogeneity of such tanks makes it extremely difficult to characterize the stresses experienced in any simple manner. This work provides a determination of both the location and the frequency of interaction of spherical fluid-borne entities with the discharge of a Rushton turbine. These data show how both particle size and impeller speed affect the severity of the exposure, setting the groundwork for improved descriptions of the dynamic behaviour of the particle size distribution in a wide variety of dispersed-phase processes.
Potential biomarker for early risk assessment of prostate cancer.

BACKGROUND. Catechol estrogen quinones (CEQ) derived from 4-hydroxyestrone (4-OHE1) and 4-hydroxyestradiol (4-OHE2) react with DNA to form depurinating—N7Gua and—N3Ade adducts. This damage leads to mutations that can initiate breast and prostate cancer. To determine whether this damage occurs in humans, urine samples from men with prostate cancer and benign urological conditions, and healthy controls were analyzed. The objective was determining whether any of the cancer patients had formed the depurinating 4-OHE1(E2)-1-N3Ade adducts. METHODS. The adducts were extracted from samples by using affinity columns equipped with a monoclonal antibody developed for detecting 4-OHE1(E2)-1-N3Ade adducts. Eluted extracts were separated by capillary electrophoresis with field-amplified sample stacking and/ or ultraperformance liquid chromatography. Absorption/luminescence spectroscopies and mass spectrometry were used to identify the adducts. RESULTS. 4-OHE1-1-N3Ade was detected at higher levels in samples from subjects with prostate cancer (n ¼ 7) and benign urological conditions (n ¼ 4) compared to healthy males (n ¼ 5). CONCLUSION. This is the first demonstration that CEQ-derived DNA adducts are present in urine samples from subjects with prostate cancer. Prostate 66: 1565–1571, 2006. # 2006 Wiley-Liss, Inc.
Superoxide dismutase activity and glutathione concentration during the calcium‐induced differentiation of Physarum polycephalum microplasmodia

Microplasmodia of Physarum polycephalum differentiate into spherules when the CaCI2 concentration of their nutrient medium is increased to 54mM (high- calcium). The salts starvation medium routinely used to induce differentiation contains 8mM CaCI2. This medium will not induce spherulation in the ab- sence of a calcium salt; no other metal is essential. High-calcium also induces the spherulation of a strain of Physarum that had not been previously ob- served to spherulate. The striking increase in superoxide dismutase activity (SOD) and the decrease in glutathione concentration (GSH) that are charac- teristic of salts-induced spherulation do not occur in salts media containing high-calcium. In the absence of calcium, no significant change in SOD is observed and very little change in GSH occurs. The immediate effect of the oxidative stress associated with spherulation may be the release of calcium stores into the cytosol. The parameters modulating this stress are, in turn, sensitive to exogenous calcium concentrations. Cellular differentiation is ultimately due to qualita- tive and quantitative alterations in gene expression. At present the nature of the mechanisms governing devel- opmental changes in gene expression remains obscure. Cytoplasmic fields, gradients, and morphogenetic deter- minants are widely believed to modulate the transition of embryonic tissues into differentiated cell types (Na- menwirth, 1974; Summerbell, 1979; Summerbell et al., 1973; Wolpert, 1978). Among the factors which appear to play a role in development are the metabolic and chemical gradients observed in developing organisms; these arise from regional variations in surfaceholume ratio and from differential vascularization of the embry- onic tissues (Boveri, 1901; Browder, 1980; Caplan and Ordahl, 1978; Child, 1915). The effects of metabolic gra- dients on development may be partly due to differential nutrient supply; however, there is also evidence that variations in molecular oxygen concentration play a role in the regulation of developmental processes (Jargiello and Caplan, 1983; Caplan and Koutroupas, 1973). The mechanism by which oxygen and its metabolites affect gene expression is presently unknown.
Host Protein Interactions with the 3′ End of Bovine Coronavirus RNA and the Requirement of the Poly(A) Tail for Coronavirus Defective Genome Replication

RNA viruses have 5' and 3' untranslated regions (UTRs) that contain specific signals for RNA synthesis. The coronavirus genome is capped at the 5' end and has a 3' UTR that consists of 300 to 500 nucleotides (nt) plus a poly(A) tail. To further our understanding of coronavirus replication, we have begun to examine the involvement of host factors in this process for two group II viruses, bovine coronavirus (BCV) and mouse hepatitis coronavirus (MHV). Specific host protein interactions with the BCV 3' UTR [287 nt plus poly(A) tail] were identified using gel mobility shift assays. Competition with the MHV 3' UTR [301 nt plus poly(A) tail] suggests that the interactions are conserved for the two viruses. Proteins with molecular masses of 99, 95, and 73 kDa were detected in UV cross-linking experiments. Less heavily labeled proteins were also detected in the ranges of 40 to 50 and 30 kDa. The poly(A) tail was required for binding of the 73-kDa protein. Immunoprecipitation of UV-cross-linked proteins identified the 73-kDa protein as the cytoplasmic poly(A)-binding protein (PABP). Replication of the defective genomes BCV Drep and MHV MIDI-C, along with several mutants, was used to determine the importance of the poly(A) tail. Defective genomes with shortened poly(A) tails consisting of 5 or 10 A residues were replicated after transfection into helper virus-infected cells. BCV Drep RNA that lacked a poly(A) tail did not replicate, whereas replication of MHV MIDI-C RNA with a deleted tail was detected after several virus passages. All mutants exhibited delayed kinetics of replication. Detectable extension or addition of the poly(A) tail to the mutants correlated with the appearance of these RNAs in the replication assay. RNAs with shortened poly(A) tails exhibited less in vitro PABP binding, suggesting that decreased interactions with the protein may affect RNA replication. The data strongly indicate that the poly(A) tail is an important cis-acting signal for coronavirus replication.
Evaluation of the Operational Multiscale Environment Model with Grid Adaptivity against the European Tracer Experiment

Abstract The Operational Multiscale Environment Model with Grid Adaptivity (OMEGA) is a multiscale nonhydrostatic atmospheric simulation system based on an adaptive unstructured grid. The basic philosophy behind the OMEGA development has been the creation of an operational tool for real-time aerosol and gas hazard prediction. The model development has been guided by two basic design considerations in order to meet the operational requirements: 1) the application of an unstructured dynamically adaptive mesh numerical technique to atmospheric simulation, and 2) the use of embedded atmospheric dispersion algorithms. An important step in proving the utility and accuracy of OMEGA is the full-scale testing of the model using simulations of real-world atmospheric events and qualitative as well as quantitative comparisons of the model results with observations. The main objective of this paper is to provide a comprehensive evaluation of OMEGA against a major dispersion experiment in operational mode. Therefore, O...
Radiologic Imaging of SymptomatiC Ligamentum Flavum Thickening with and Without Ossification

Thickening of the ligamenta flava with and without ossification in the thoracic and lumbar regions is a frequent finding on CT scanning; however, it is not widely appreciated as a possible primary cause of compressive cord, cauda equina, and nerve-root symptoms. We present observations from a series of seven patients whose symptoms were caused exclusively or largely by thickened ligamenta flava in the thoracic and lumbar regions. The findings were best demonstrated on myelography. One of our cases had been missed on previous MR, as would be expected with the null signal of calcification. CT scanning necessitates an extended window to ensure discrimination of an ossified ligament from thecal metrizamide. Thickened ligamenta flava are often found in conjunction with degenerative disease and spinal stenosis at multiple levels and should not be ignored as a possible major contributing factor to the patient's symptoms. In addition, those patients with a secondary block from a thickened ligamentum flavum should be studied from above with C1-C2 puncture to rule out other levels of clinically significant disease. Attention to the particular findings of thickened ligamenta flava is important since surgical intervention must involve removal of the entire offending ligament(s); otherwise clinical symptoms may not be relieved.
Forging a Truly Utilitarian Copyright

In this Article, Professor Stadler uses the tool of art forgery to explore how far copyright law has strayed from the utilitarianism of the framers, who subscribed to a "moral sense" school of philosophy that elevated the interests of society over private interests, or "rights." When it comes to copyright law, she argues, utilitarianism is alive only in theory; in practice, utilitarianism has become a dead language that lawmakers speak when they engage in the practice of making copyright law. In demonstrating how we might forge a truly utilitarian copyright, Professor Stadler does what she terms the "utilitarian math": subtracting costs from benefits; weighing suffering against happiness; and finding the level of exclusivity that provides society with the greatest benefit. In the end, she argues, embracing utility requires us to engage in the heterodoxy of discriminating among types of authors on the basis of what they provide to society. Perversely, perhaps, it also requires us to withhold exclusivity from some authors - even those whose contributions we most value.
The hydrophobic effect, and fluctuations: The long and the short of it.

The hydrophobic effect, which is used to describe the aversion of oil for water or the affinity of oily objects for one another in water, plays an important role in diverse disciplines (1). For example, by segregating to the oil–water interface, amphiphilic molecules that possess both hydrophobic and hydrophilic groups can mitigate unfavorable oil–water interactions, thereby stabilizing emulsions and facilitating detergency. Because roughly half the amino acids, which form the basic building blocks of proteins, are hydrophobic, the hydrophobic effect also plays a central role in biophysics. Owing to its ubiquity and its multifaceted nature (2, 3), being able to accurately model the hydrophobic effect is both important and challenging. In PNAS, Vaikuntanathan et al. (4) provide important insights into the essential ingredients required in a minimal model of the hydrophobic effect. The hydrophobic effect characteristically manifests itself in very different ways at microscopic and macroscopic length scales (1). Macroscopically, the aversion of oil and water for one another is captured by the large surface tension associated with the oil–water interface. At this scale, the hydrophobic effect drives the minimization of the unfavorable interfacial area (for example, by the coalescence of oil droplets in water). Although the macroscopic hydrophobic effect is governed by the relatively straightforward physics of interfaces, it can nevertheless lead to complex phenomena, such as the nanobubble-mediated long-ranged forces between extended hydrophobic surfaces (5), or the assembly of anisotropic particles at curved interfaces (6). Interestingly, the thermodynamic driving force for such hydrophobic assembly, which is dictated by interfacial tension, decreases with increasing temperature. In contrast, at the molecular scale, the driving force for hydrophobic assembly famously increases with increasing temperature (1). In fact, whenever biomolecular assembly occurs upon increasing temperature, in seeming disregard for entropic considerations, the hydrophobic effect is often the first suspect. A classic … [↵][1]1To whom correspondence should be addressed. Email: amish.patel{at}seas.upenn.edu. [1]: #xref-corresp-1-1
Global convergence of the restricted broyden class of quasi-Newton algorithms on nonconvex functions with Goldstein line search

In this paper,the properties of Convergence of the restricted Broyden class of quasi-Newton algorithms on nonconvex functions with Goldstein line search is investigated and under certain condition the global convergence of the algorithms proved.