cssi/SciSciGPT-SciSciNet huggingface dataset:
On setting a pressure datum when computing incompressible flows

SUMMARY The conventional approach to set the pressure level in a finite element discretization of an enclosed, steady, incompressible flow is to discard a continuity residual and set the associated pressure basis function coefficient to a desired value. Two issues surrounding this setting of a pressure datum are explored. First, it is shown that setting a boundary traction at a single node, in lieu of a Dirichlet velocity condition, is a preferred alternative for use with pressure-stabilized finite element methods. Second, it is shown that setting a pressure datum can slow or even stop the convergence of a GMRES-based iterative solver; though by some appearances a solution may appear to be converged, significant local errors in the velocity may exist. Under such circumstances it is preferable to solve the consistent singular system of equations, rather than setting a pressure datum. It is shown that GMRES converges in such cases, implicitly setting a pressure level that is determined from the initial guess. Copyright © 1999 John Wiley & Sons, Ltd. 1. BACKGROUND There has been a long history of research on proper and useful representations of the pressure field in finite element computations of incompressible flows. This prior research has resulted in conventional approaches involving mixed-order interpolation with the Galerkin finite element method (GFEM) and newer approaches employing equal-order interpolation with stabilized methods. Irrespective of the approach employed for computation, the solution of an incompressible flow within an enclosed domain contains a hydrostatic pressure mode that causes the pressure field to be indeterminant with respect to an arbitrary constant. Accommodating this simple effect is straightforward when employing classical GFEM techniques in conjunction with direct solution methods, but some important issues associated with the hydrostatic pressure mode when using newer finite element implementations, and when using iterative solution methods are discussed below. The relationship between the hydrostatic pressure mode and mass continuity of an incompressible fluid was clearly elucidated by Sani et al. [1,2] and Engelman et al. [3]. Following their work, our starting point is the statement of global mass conservation
Metacognitive awareness of event-based prospective memory

This study examined people's ability to predict and postdict their performance on an event-based prospective memory task. Using nonfocal cues, one group of participants predicted their success at finding animal words and a different group predicted their ability to find words with a particular syllable in it. The authors also administered a self-report questionnaire on everyday prospective and retrospective memory failures. Based on the different strategies adopted by the two groups and correlations among the dependent variables, the authors concluded that people do have a basic awareness of their prospective memory abilities, but that this awareness is far from accurate. The importance of metamemory concerning one's prospective memory is discussed in terms of how it influences the strategies that people might choose for actually completing their various everyday intentions.
Does movement toward better environments always benefit a population

Abstract We study the effects of advection along environmental gradients on logistic reaction–diffusion models for population growth. The local population growth rate is assumed to be spatially inhomogeneous, and the advection is taken to be a multiple of the gradient of the local population growth rate. It is also assumed that the boundary acts as a reflecting barrier to the population. We show that the effects of such advection depend crucially on the shape of the habitat of the population: if the habitat is convex, the movement in the direction of the gradient of the growth rate is always beneficial to the population, while such advection could be harmful for certain non-convex habitats.
A teaching model for the use of computers in direct practice

The purpose of this brief report is twofold: to provide one teaching approach designed to help students and clinicians use the computing facilities available in their agencies to aid their clinical practice, and to highlight issues central to this training. The teaching model presented is based on a four-step process: Using the computer as a tool, the student moves through the process of identifying relevant practice based questions, to operationalizing these questions, to analyzing the data collected, and finally to interpreting and applying the results. This teaching innovation and our positive experience with it offers further support for the place of computers in a clinical practice curriculum and serves as a useful reference to other individuals, institutions, or agencies that are planning to offer similar training.
Interactions between Cardiac Glycosides and Sodium/Potassium-ATPase: Three-Dimensional Structure−Activity Relationship Models for Ligand Binding to the E2-Pi Form of the Enzyme versus Activity Inhibition†

Sodium/potassium-ATPase (Na/K-ATPase) is a transmembrane enzyme that utilizes energy gained from ATP hydrolysis to transport sodium and potassium ions across cell membranes in opposite directions against their chemical and electrical gradients. Its transport activity is effectively inhibited by cardiac glycosides, which bind to the extracellular side of the enzyme and are of significant therapeutic value in the treatment of congestive heart failure. To determine the extent to which high-affinity binding of cardiac glycosides correlates with their potency in inhibiting pump activity, we determined experimentally both the binding affinities and inhibitory potencies of a series of 37 cardiac glycosides using radioligand binding and ATPase activity assays. The observed variations in key structural elements of these compounds correlating with binding and inhibition were analyzed by comparative molecular similarity index analysis (CoMSIA), which allowed a molecular level characterization and comparison of drug−...
Traffic performance characterisation of a personal radiocommunication system

A recently proposed personal radiocommunication system is described. The system, which is intended to provide a low-cost mobile radiotelephone service, employs a novel radio link architecture that combines features of centralised and distributed control. Consumers would typically purchase two transceivers, one for a vehicle, the other for the home. The latter unit interfaces with the public switched telephone network through an ordinary modular coupling. Two types of payload radio channels are used, local direct and repeater. Users gain access to these channels by successfully completing a specified exchange of command messages on supervisory channels used in a random access mode. An analytical model was developed to characterise traffic performance and a simulation of the proposed system's traffic characteristics was undertaken. Both are described in the paper. Predicted performance characteristics are presented.
The Development and Validation of an Entrance Examination in a Mexican University

A review of the literature reveals no published research on the use of college entrance examinations in Mexico. A validity study on a locally developed college entrance examination at the Autonomous University of Chihuahua, Mexico was conducted on the entire freshman class entering the college of Accounting and Business Administration. The entrance examination scores, secondary school grades, Beta IQs, and other variables were subjected to multiple regression analysis to predict university grade point average (GPA). Results indicated that all 13 variables combined accounted for only 20% of the total variance in the criterion measure with only two variables, mathematics and secondary school grades, explaining most of the total variance. A critical analysis of the entrance examination and the university selection procedures is discussed and contrasted with data from United States colleges.
Nonreciprocity Noise in Fiber Gyroscopes and Measurement of Fiber Dispersion

It has been shown previously (1) that the dispersion term in the Fresnel drag coefficient can be detected using a moving single mode fiber as the beam path. This letter reports on the results of a study of optical noise sources in fiber gyroscopes as well as on determining the dispersion term with higher accuracy.
Ammonia Neurotoxicity and the Mitochondrial Permeability Transition

Ammonia is a neurotoxin that predominantly affects astrocytes. Disturbed mitochondrial function and oxidative stress, factors implicated in the induction of the mitochondrial permeability transition (MPT), appear to be involved in the mechanism of ammonia neurotoxicity. We have recently shown that ammonia induces the MPT in cultured astrocytes. To elucidate the mechanisms of the MPT, we examined the role of oxidative stress and glutamine, a byproduct of ammonia metabolism. The ammonia-induced MPT was blocked by antioxidants, suggesting a causal role of oxidative stress. Direct application of glutamine (4.5–7.0 mM) to cultured astrocytes increased free radical production and induced the MPT. Treatment of astrocytes with the mitochondrial glutaminase inhibitor, 6-diazo-5-oxo-L-norleucine, completely blocked free radical formation and the MPT, suggesting that high ammonia concentrations in mitochondria resulting from glutamine hydrolysis may be responsible for the effects of glutamine. These studies suggest that oxidative stress and glutamine play major roles in the induction of the MPT associated with ammonia neurotoxicity.
Traveling waves in a simple population model involving growth and death

The structure of solutions to a simple spatially dependent population model involving growth and death is investigated. Two forms of motility of the population are considered: (1) random motion only modeled by a Fickian law, and (2) a directed component of motion (chemotaxis), included in addition to the random motion. Under certain growth conditions a traveling wave of constant speed is approached. This speed can be increased by the addition of the chemotaxis with a corresponding increase in the asymptotic population. Development of initial conditions into a wave is illustrated numerically.
RELIABILITY AND VALIDITY EVIDENCE FOR THE EARLI LITERACY PROBES

The purpose of this study was to examine the reliability and validity of scores from six early literacy probes developed for use with preschool-age children. The literacy probes were administered to 84 preschoolers at three time points over a 6-month period. Also, a criterion measure of early literacy skills was administered to a subset of students. Results indicated that the probes demonstrate adequate reliability for screening decisions, moderate to strong concurrent relationships with a criterion measure, and developmentally appropriate changes in children's early literacy skills over time. These results add to the growing body of evidence supporting the technical adequacy of general outcome measurement for use in monitoring the progress of preschoolers' academic skill development. © 2009 Wiley Periodicals, Inc.
The association of inadequate mid-pregnancy weight gain and preterm birth in twin pregnancies

The association of inadequate mid-pregnancy weight gain and preterm birth in twin pregnancies
Surface complexation of methylated arsenates by hydrous oxides

Abstract The adsorption of methyl arsenate and dimethyl arsenate on hydrous ferric oxide and activated alumina was measured as a function of pH, ionic strength and sorbate-sorbent ratio by the bottle-point method and the characteristics of the two oxide surfaces were determined by surface titration. Adsorption decreased with increasing pH while it was only weakly dependent on ionic strength. The results were interpreted in terms of the triple-layer surface complexation model by assuming that arsenicals formed inner-sphere complexes with the oxide surface. A satisfactory interpretation of results could be made by modifying the triple-layer model to include surface sites of two different adsorption energies. Attempts to model adsorption considering a homogeneous surface were unsatisfactory.
Phosphorylation of mitogen-activated protein kinase in cultured rat cortical glia by stimulation of metabotropic glutamate receptors

Activation of metabotropic glutamate receptors (mGluRs) in glia results in significant physiological effects for both the glia and the neighboring neurons; but in many cases, the mGluR subtypes and signal transduction mechanisms mediating these effects have not been determined. In this study, we report that mGluR activation in primary cultures of rat cortical glia results in tyrosine phosphorylation of several proteins, including p44/p42 mitogen-activated protein kinases, also referred to as extracellular signal-regulated kinases (ERK1/2). Incubation of glial cultures with the general mGluR agonist 1-aminocyclopentane-1S,3R-dicarboxylate and the mGluR group I-selective agonists (RS)-3,5-dihydroxyphenylglycine (DHPG) and L-quisqualate resulted in increased tyrosine phosphorylation of ERK1/2. The group II-selective agonist (2S,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl)glycine and group III-selective agonist L(+)-2-amino-4-phosphonobutyric acid had no effect on tyrosine phosphorylation. DHPG-induced ERK1/2 phosphorylation could be inhibited by an antagonist that acts at group I or group II mGluRs but not by antagonists for group II and group III mGluRs. Protein kinase C (PKC) activators also induced ERK1/2 phosphorylation, but the PKC inhibitor bisindolylmaleimide I did not inhibit DHPG-induced ERK1/2 phosphorylation at a concentration that inhibited the response to phorbol 12,13-dibutyrate. These data suggest that mGluR activation of ERK1/2 in cultured glia is mediated by group I mGluRs and that this effect is independent of PKC activation. Furthermore, immunoblots with antibodies against various mGluR subtypes show expression of mGluR5, but no other mGluRs in our cultures. Taken together, these results suggest that mGluR5 stimulation results in tyrosine phosphorylation of ERK1/2 and other glial proteins.
Liver invasion of the duodenum due to hepatocellular carcinoma.

m c T 9 s c A man with hepatocellular carcinoma (HCC) presented with upper-gastrointestinal bleeding for the fifth time n 7 months and new-onset severe nausea and vomiting. Over the ast year, the patient had undergone transarterial chemoemboliation as well as radiotherapy with concurrent capecitabine (Xeoda; Genetech, San Francisco, CA) for treatment of HCC. Prior pper endoscopies showed a pyloric channel ulceration with nuerous interventional attempts to control bleeding, including pinephrine injection and endoscopic clipping, and angiographic oiling of branches of the gastroduodenal artery, left gastric artery, nd left hepatic artery. A biopsy obtained 5 months before the resentation revealed fibrinopurulent debris in addition to large typical cells with relatively abundant eosinophilic cytoplasm that eacted with the hepatocyte paraffin 1 (Hep Par 1) antibody (a onoclonal antibody to hepatocyte mitochondria) (Figure A, 0 ). On upper endoscopy, a large mass was seen penetrating the yloric channel wall and occupying more than 90% of the lumen, ausing gastric outlet obstruction. After clearing the debris, the ass appeared to be relatively normal-appearing liver and upon robing was firm (Figure B). A computed tomography scan after ndoscopy showed a large, rapidly expanding hepatocellular carinoma (arrowheads) and a pointed hepatic wedge in the location of he pyloric channel (arrow) (Figure C). The patient was transiioned to palliative care and died approximately 1 month later. irect invasion of HCC into the gastrointestinal lumen typically hows a fungating mass consistent with malignancy. This case hows normal-appearing liver that was pushed through the duoenal wall by an enlarging HCC. The incidence of hepatocellular carcinoma is increasing in any countries, and surveillance for at-risk populations is recmmended. Gastric or small-bowel involvement of HCC is rare1 and first was described in 1987 in the setting of a duodenal bleeding mass.2 The most common presentation is gastrointesinal bleeding, and survival is poor.3 Hep Par 1 is a monoclonal antibody that reacts with hepatocytes but not bile duct and nonparenchymal liver cells.4 Hep Par 1 can be used to differentiate alignant cells of hepatocyte origin (HCC) from other malignanies including cholangiocarcinoma and metastatic carcinomas. he sensitivity and specificity of Hep Par 1 for HCC was 82.1% and 3.3%, respectively, in one study.5 Although Hep Par 1 is a highly pecific marker in HCC, positive results have been reported in ases of cholangiocarcinoma4 and nonhepatic tumors.3
The strict time lower bound and optimal schedules for parallel prefix with resource constraints

Prefix computation is a basic operation at the core of many important applications, e.g., some of the Grand Challenge problems, circuit design, digital signal processing, graph optimizations, and computational geometry. In this paper, we present new and strict time-optimal parallel schedules for prefix computation with resource constraints under the concurrent-read-exclusive-write (CREW) parallel random access machine (PRAM) model. For prefix of N elements on p processors (p independent of N) when N>p(p+1)/2, we derive Harmonic Schedules that achieve the strict optimal time (steps), [2(N-1)/(p+1)]. We also derive Pipelined Schedules that have better program-space efficiency than the Harmonic Schedule, yet only require a small constant number of steps more than the optimal time achieved by the Harmonic Schedule, Both the Harmonic Schedules and the Pipelined Schedules are simple and easy to implement. For prefix of N elements on p processors (p independent of N) where N/spl les/p(p+1)/2, the Harmonic Schedules are not time-optimal. For these cases, we establish an optimization method for determining key parameters of time-optimal schedules, based on connections between the structure of parallel prefix and Pascal's triangle. Using the derived parameters, we devise an algorithm to construct such schedules. For a restricted class of values of N and p, we prove that the constructed schedules are strictly time-optimal. We also give strong empirical evidence that our algorithm constructs strict time optimal schedules for all cases where N/spl les/p(p+1)/2.
John Barlow: Mitral valve prolapse

Although the systolic click was first mentioned in the medical literature in 1887, it was not until the investigations of John Barlow and his colleagues in the 1960s that it became linked to the mitral valve and mitral valve prolapse identified as the cause. Mitral valve prolapse is currently the most commonly diagnosed cardiac valvular abnormality. Significant complications may occur with mitral valve prolapse, though most patients are asymptomatic. However, a number of issues persist regarding mitral valve prolapse, especially with respect to the mitral valve prolapse syndrome, a term which has been applied to patients who develop a variety of symptoms, including chest pain, shortness of breath, fatigue, lightheadedness, syncope, palpitations, anxiety, and panic attacks.
Training endoscopists to recognize the stigmata of hemorrhage in bleeding ulcers.

Correctly assessing the stigmata of recent hemorrhage is critical to providing appropriate endoscopic and medical management in patients with bleeding ulcers. However, the task of training endoscopists to recognize stigmata in ulcers is particularly difficult, for a number of reasons. First, the source of bleeding must be located, and this may be difficult when blood is present or the patient is unstable; second, the ulcer base must be completely examined, sometimes requiring target irrigation or manipulation of the surrounding folds with a device; third, the presence or absence of stigmata must be recognized; and finally, the stigma must be accurately identified. A major problem is that even expert endoscopists and investigators in the field of hemostasis have not achieved a consensus on definitions of stigmata. Nonetheless, the available data suggest that endoscopists can be trained to identify stigmata with reasonable consistency
Attorneys Fees in Class Action Settlements: An Empirical Study

Study of two comprehensive class action case data sets covering 1993-2002 shows that the amount of client recovery is overwhelmingly the most important determinant of the attorneys' fee award. Even in cases in which the courts engage in the lodestar calculation (the product of reasonable hours and a reasonable hourly rate), the client's recovery generally explains the pattern of awards better than the lodestar. Thus, the time and expense of a lodestar calculation may be wasteful. We also find no robust evidence that either recoveries for plaintiffs or fees of their attorneys increased over time. The mean fee award in common fund cases is well below the widely-quoted one-third figure, constituting 21.9 percent of the recovery across all cases for a comprehensive data set of published cases. A scaling effect exists: fees constitute a lower percent of the client's recovery as the client's recovery increases. Fees are also correlated with risk: the presence of high risk is associated with a higher fee, while low risk cases generate below-average fees. Fees as a percent of class recovery were found to be higher in federal than state court. The presence of "soft" relief (such as injunctive relief or coupons) has no material effect on the fee, whether or not the soft relief was calculated in the quantified benefit for the class used as the basis for computing the attorney's fee. The study also addressed costs and expenses. Like fees, these displayed significant scale effects. The paper proposes a simple methodology by which courts can evaluate the reasonableness of fee requests.
Use of complementary medications among older adults with cancer

BACKGROUND Little is known about complementary medication use among older adults with cancer, particularly those undergoing chemotherapy. The purpose of this study was to evaluate the prevalence of complementary medication use and to identify factors associated with its use among older adults with cancer.
Direct, in-scanner, aerial image sensing

With feature sizes now less than one half of the wavelength of the actinic radiation, determining the intensity distribution in the aerial image has become both more critical because of the low k1 factors used and more challenging because of the limitations of scalar diffraction theory. Here we describe ways of measuring in situ the intensity distribution generated at the wafer surface by the wafer exposure tool ('scanner' or 'stepper') and that eliminate the delays and vagaries of resist processing. Some early results show a 2D image generated by an aerial image sensor loaded into an unmodified 193nm scanner. Nominal feature sizes are down to 67nm. One additional advantage of this technique over the slower alternative of SEM viewing of the resist image is the gray-scale of the intensity image from the sensor. Applications can include assurance of the correctness of the stepper-mask combination, verification and development of the modeling of the aerial image (including the effect of resolution enhancing techniques) and the qualification of incoming masks.
Hydrogen and Helium Leak Rates from Micromachined Orifices

Hydrogen is widely in use in rocket propulsion systems, and as such, leakage of hydrogen from high-pressure fuel tanks requires accurate quantie cation. Safety concerns have led to the practice of conducting leak tests with helium (an inert gas) and to try to infer the hydrogen leak rates from helium data, often employing assumptions of essentially isentropic e ow processes and choked leak orie ces. The experimental study sought to quantify precisely the relationships between hydrogen and helium leak rates for various types of leaks. Simulated leak sources were fabricated by micromachining leaks or holes of prescribed shapes and cross-sectional areas in silicon wafers, utilizing the processes of photolithography and deep reactive ion etching. Dual thermal conductivity detectors were used to evaluate helium and hydrogen leak rates and to quantify differences in discharge coefe cients among the various microorie ces. Based on this quantie cation, the standard helium signature test procedure was found to underpredict hydrogen leak rates, in some cases signie cantly, if the corresponding helium tests are conducted at much lower pressures than those at which hydrogen leak rates are sought. Nomenclature Aorie ce = effective cross-sectional area of leak source DC = discharge coefe cient representing dissipation [Eq. (3)] dhyd = orie ce hydraulic diameter Kn = Knudsen number, ¸=L L = characteristic length m = molecular mass of gas species P m = mass e ow rate p = static pressure pt = stagnation pressure R = gas constant, <=m < = universal gas constant Red = Reynolds number .ΩUd/=π Tt = stagnation temperature U = bulk velocity ° = ratio of specie c heats, cp=cv ¸ = mean free path π = absolute viscosity Ω = gas density
Mechanical properties of formcoke after reaction in CO2 and COCO2 environments

The mechanical properties of a special formcoke were studied after reaction in CO2 and in COCO2 mixtures. The effects of iron- and potassium-catalyzed gasification were also investigated. The Young's elastic modulus, fracture toughness and fracture surface energy were all observed to decrease with increasing amounts of reaction of the formcoke. These properties were observed to be strongly correlated to the final bulk density rather than to the particular reaction conditions.
A People’s Method(ology) A Dialogical Approach

This is a critical dialogue between graduate student and activists in the discipline of sociology. Critical approaches to the essential question of critical race studies are discussed and evaluated in terms of their ability to develop a theory and praxis for changing the structural and cultural inequalities that constitute the enduring legacy of the colonial project and slavery. Conventional sociological methodologies as well as combative epistemologies and pedagogies, suffer from an inability to inform and be informed by real world movements for social justice and thus are limited in their applicability beyond the ivory tower.Through a Freirean critical dialogue the possibility for a human method of mobilization emerges that has the potential for aiding with the liberation struggles of all oppressed peoples. The authors hope that this dialogue will be taken up by other peoples in other places to further their quest for social justice.
Statistical cost Analysis Re-Revisited: Reply

The issues raised by Maddala and Roberts go well beyond the question of whether pseudo-data analysis is useful empirically. It is unfortunate that their paper was not written in response to the first translog application by Christensen, Jorgenson, and Lau. This would allow separation of questions unique to pseudo-data analysis from the questions aimed more generally at the translog and other generalized functional forms. In this reply I shall attempt to separate these two questions, showing that a major portion of Maddala and Roberts' concerns relates essentially to the approximation characteristics of generalized functional forms, irrespective of the type of data used for estimation. These issues are examined in Section II. In Section III we discuss Maddala and Roberts' raising of the important question of optimal sample design and functional form, noting that there is no necessity to use orthogonal price variation and the translog function. Finally, we address in Section IV the claim that direct use of process models in place of its statistical cost function approximation is to be preferred in policy and modeling exercises.
An improved parachute drogue system for monitoring currents in the deep ocean

Abstract A parachute drogue is described that can quickly be assembled and easily launched at sea. An anchored buoy, which provides a reference from which drogue trajectories can be determined is also described and methods for launching are outlined. This buoy, which can be moored in several kilometers depth, will extend to the deep ocean the use of drogue monitoring techniques capable of defining wind driven currents and their short-term periodicities.
Anterior pituitary adenylate cyclase: stimulation by dopamine and other monoamines.

Abstract Adenylate cyclase activity of homogenates of anterior pituitary from rat, rabbit and monkey was stimulated by dopamine, other amine neurotransmitters and Gpp(NH)p. The concentration of dopamine for half-maximal stimulation of activity was 2–5 μM. Studies with selective agonists and antagonists indicated the presence of dopamine receptors and β-adrenergic receptors coupled to adenylate cyclase in anterior pituitary. In addition, histamine stimulated activity in rabbit and monkey, but not in rat, anterior pituitary.
Phenomenology of one-dimensional quantum liquids beyond the low-energy limit.

We consider the zero temperature behavior of dynamic response functions of 1D systems near edges of support in the momentum-energy plane $(k,\ensuremath{\omega})$. The description of the singularities of dynamic response functions near an edge $\ensuremath{\epsilon}(k)$ is given by the effective Hamiltonian of a mobile impurity moving in a Luttinger liquid. For Galilean-invariant systems, we relate the parameters of such an effective Hamiltonian to the properties of the function $\ensuremath{\epsilon}(k)$. This allows us to express the exponents which characterize singular response functions of spinless bosonic or fermionic liquids in terms of $\ensuremath{\epsilon}(k)$ and Luttinger liquid parameters for any $k$. For an antiferromagnetic Heisenberg spin-$1/2$ chain in a zero magnetic field, $SU(2)$ invariance fixes the exponents from purely phenomenological considerations.
Brevetoxin metabolism and elimination in the Eastern oyster (Crassostrea virginica) after controlled exposures to Karenia brevis.

Abstract The metabolism and elimination of brevetoxins were examined in the Eastern oyster ( Crassostrea virginica ) following controlled exposures to Karenia brevis cultures in the laboratory. After a 2-day exposure period (∼62 million cells/oyster), elimination of brevetoxins and their metabolites was monitored by using liquid chromatography/mass spectrometry (LC/MS). Composite toxin in oyster extracts was measured by in vitro assay (i.e. cytotoxicity, receptor binding, and ELISA). Of the parent algal toxins, PbTx-1 and PbTx-2 were not detectable by LC/MS in K. brevis -exposed oysters. PbTx-3 and PbTx-9, which are accumulated directly from K. brevis and through metabolic reduction of PbTx-2 in the oyster, were at levels initially (after exposure) of 0.74 and 0.49 μg equiv./g, respectively, and were eliminated largely within 2 weeks after dosing. PbTx-7 and PbTx-10, the reduced forms of PbTx-1, were non-detectable. Conjugative brevetoxin metabolites identified previously in field-exposed oysters were confirmed in the laboratory-exposed oysters. Cysteine conjugates of PbTx-1 and PbTx-2, and their sulfoxides, were in the highest abundance, as apparent in LC/MS ion traces, and were detectable for up to 6 months after dosing. Composite toxin measurements by in vitro assay also reflected persistence (up to 6 months) of brevetoxin residues in the oyster. Levels of cysteine conjugates, as determined by LC/MS, were well correlated with those of composite toxin, as measured by ELISA, throughout depuration. Composite toxin levels by cytotoxicity assay were well correlated with those by receptor binding assay. Cysteine–PbTx conjugates are useful LC/MS determinants of brevetoxin exposure and potential markers for composite toxin in the Eastern oyster.
Rainfall anomaly prediction using statistical downscaling in a multimodel superensemble over tropical South America

This study addresses the predictability of rainfall variations over South America and the Amazon basin. A primary factor leading to model inaccuracy in precipitation forecasts is the coarse resolution data utilized by coupled models during the training phase. By using MERRA reanalysis and statistical downscaling along with the superensemble methodology, it is possible to obtain more precise forecast of rainfall anomalies over tropical South America during austral fall. Selective inclusion (and exclusion) of member models also allows for increased accuracy of superensemble forecasts. The use of coupled atmospheric–ocean numerical models to predict the rainfall anomalies has had mixed results. Improvement in individual member models is also possible on smaller spatial scales and in regions where substantial topographical changes were not handled well under original model initial conditions. The combination of downscaling and superensemble methodologies with other research methods presents the potential opportunity for increased accuracy not only in seasonal forecasts but on shorter temporal scales as well.
Synthesis of substituted 2-methyl-3-(3,4-dimethoxy/dihydroxyphenylethyl)4-quinazolones as possible antiparkinson drugs

Several substituted 2-methyl-3-(3,4-dimethoxy/dihydroxyphenylethyl)-4-quinazolones were synthesized as possible antiparkinsonism agents. The structure of these compounds were confirmed by their elemental and spectral analysis.
Digital Processing Of Low Resolution Halftone Images

Perspectives of a few challenging problems in the digital processing of low resolution halftone images are presented. The topics covered include screen selection, tonal reproduction control, and the scaling and resolution conversion of halftone images. Particular emphasis is placed on a new method of digital scaling and resolution conversion of electronically stored low resolution halftone images. Several simulation examples are given.
Correlation of CHADS2 and CHA2DS2-VASc Scores with Transesophageal Echocardiography Risk Factors for Thromboembolism in a Multiethnic United States Population with Nonvalvular Atrial Fibrillation

Background The aims of this study were to evaluate the relationship of the CHA 2 DS 2 -VASc score and risk categories with transesophageal echocardiographic (TEE) risk factors for thromboembolism and to compare the CHA 2 DS 2 -VASc and CHADS 2 risk stratification schemes with respect to their ability to predict these risk factors in a multiethnic US population with nonvalvular atrial fibrillation. Methods Transesophageal echocardiograms of 167 patients (mean age, 66.3 ± 11.6 years; 146 men [87%]; 100 whites [60%]; 40 Hispanics [24%]; 27 blacks [16%]) with nonvalvular atrial fibrillation were retrospectively reviewed for smoke, sludge, thrombus, and left atrial appendage (LAA) emptying velocity ≤20 cm/sec. The patients' CHA 2 DS 2 -VASc and CHADS 2 risk scores and categories were also calculated. Results Any LAA abnormality, smoke, sludge, thrombus, and abnormal LAA emptying velocity were present in 45%, 38%, 13%, 3%, and 22% of patients, respectively. Heart failure ( P P P = .013 for age 65–74 vs ≤64 years), and diabetes ( P = .019) were independent predictors of LAA abnormalities, while ethnicity was not. The prevalence of TEE risk factors for thromboembolism increased with increasing CHA 2 DS 2 -VASc score and risk category. The CHADS 2 risk categories of 35 patients (21%) were upgraded by the CHA 2 DS 2 -VASc scheme. Using the latter scheme, fewer patients were classified as at intermediate risk compared with the CHADS 2 system (21 [13%] vs 46 [28%]). Patients classified as at low risk by either scheme had almost no TEE risk factors. Of 30 intermediate-risk patients by CHADS 2 score upgraded to high risk using CHA 2 DS 2 -VASc score, eight (27%) had at least one TEE risk factor for thromboembolism. C-statistics, sensitivity, and specificity for predicting any LAA abnormality were 0.607 (95% confidence interval, 0.549–0.665), 92.0%, and 28.9% for CHA 2 DS 2 -VASc score and 0.685 (95% confidence interval, 0.615–0.755), 81.3%, and 54.2% for CHADS 2 score. Conclusions CHA 2 DS 2 -VASc score is associated with TEE risk factors for thromboembolism in a multiethnic US population. Compared with CHADS 2 score, it has increased sensitivity, decreased specificity, and lower ability for predicting TEE risk factors in this population.
Subfecundity: a prenatal risk factor for adults but not for adolescents.

Abstract Young maternal age is associated with an increased incidence of low birth weight and prematurity; controlling for sociodemographic factors reduces the significance of this relationship. We hypothesized that this is partly because in a sociodemographically homogeneous population the adverse effects of maternal subfecundity on fetal growth confound the relationship between maternal age and infant outcome. To test this hypothesis, we studied the reproductive histories of 90 adolescent ( r = 0.40; p p = 0.02). Our findings demonstrate that it is important that adult controls for adolescent pregnancy studies have voluntarily postponed conception.
Native azurin and its Ni(II) derivative: a resonance Raman study.

Abstract Resonance Raman spectra are reported for native Cu(II) Pseudomonas aeruginosa azurin and its Ni(II) substituted derivative. The spectrum of the native azurin includes a low frequency feature and bands in the first overtone region not previously reported. The spectrum of the Ni(II) derivative exhibits three major peaks in the metal-ligand stretching region shifted to lower frequency relative to the M-L peaks in the spectrum of native azurin. Resonance enhanced ligand modes are observed which indicate that at least two of the ligands in Ni(II) azurin (cysteine and at least one histidine) are the same as in native azurin. The data also suggest that the disposition of ligands about the metal may be more nearly tetrahedral in the Ni(II) derivative than in native azurin.
The networking philosopher's problem

While computer networking is an exciting research field, we are far from having a clear understanding of the core concepts and questions that define our discipline. This position paper, a summary of a talk I gave at the CoNext'10 Student Workshop, captures my current frustrations and hopes about the field.
Topological Theory of Entanglement : A Polymer Chain and a Fixed Barrier. : III. Numerical Results

Explicit expressions of γ α 2 , d 0 and δ α are derived and they are computed numerically as functions of N , the polymerization number and r , the distance between the center of mass of a polymer chain and a fixed barrier. The frictional coefficient ζ of the center of mass is also computed as a function of N and r based on the expression derived in the second paper of this series and it is shown that ζ of an entangling polymer chain takes, at \(r{\approx}\frac{1}{2}\sqrt{N}b\), its maximum value which is 20∼50% larger than that of a “free” chain.
Simulations of Heat Transport During Transient Electrostatic Discharge Events in a Sub-Micron Transistor

The thermal problem associated with the transient electrostatic discharge phenomena in sub-micron silicon transistors is fast becoming a major reliability concern in IC packages. Currently, Fourier diffusion and some simple models based on the solution to the phonon Boltzmann transport equation (BTE) are used to predict failure (melting of silicon) in these transistors. In this study, a more comprehensive model, based on the phonon BTE and incorporating considerable details of phonon physics, is proposed and used to study the ESD problem. Transient results from the model reveal very significant discrepancies when compared to results from the other models in the literature.Copyright © 2004 by ASME
A methodology for analyzing the temporal evolution of novice programs based on semantic components

Empirical studies of novice programming typically rely on code solutions or test responses as the basis of their analyses. While such data can provide insight into novice programming knowledge, they say little about the programming processes in which novices engage. For those interested in improving novice programming environments, a key research question arises: How can we collect and analyze data on novice programming that will enable us (a) to analyze and compare the programming processes promoted by alternative novice programming environments, and (b) ultimately to build better novice programming environments? To address this question, we have collected a large video corpus of novices as they construct code solutions in various versions of ALVIS Live! [17], a novice programming environment. Through detailed post-hoc analyses of our video corpus, we have developed a methodology for compiling the moment-by-moment evolution of novice code solutions. Based on an analysis of a model code solution's key semantic components, our methodology enables researchers to document, on a second-by-second basis, (a) what part of a code solution a programmer is focusing on, and (b) where the semantic feedback provided by the programming environment is helping. Although it is time and labor intensive, our methodology provides researchers with a standard set of data and representations for comparing the programming processes promoted by alternative programming environments.
Clustering of metal atoms in organic media. 9. High-activity Ni/MgO catalysts prepared by metal vapor methods. Surface area and particle size effects

Abstract A metal vapor method was employed to prepare highly dispersed Ni metal catalysts (solvated metal atom dispersed = SMAD catalyst) supported on MgO. Compared with conventional Ni MgO compositions, the SMAD catalysts showed much greater activities for all reactions studied (hydrogenolysis of methylcyclopentane, MCP; hydrogenation/hydrogenolysis of toluene, TOL; methanation of carbon monoxide, CO; dehydration of isopropyl alcohol, IPA). These high activities for the SMAD catalysts are attributed to the high surface area of Ni on MgO and the high percentage of this Ni in a zero-valent state (“reduction degree”). Conventional methods for preparing Ni MgO catalysts did not yield nearly such favorable surface areas or reduction degrees. Nickel particle size effects were observed during hydrogenolysis studies of MCP and hydrogenation studies of TOL. These phenomena are explained by assuming the size of an active Ni particle to be largest for hydrogenolysis of MCP > hydrogenation of TOL > methanation of CO ∼- dehydrogenation of IPA.
Development of the Vault Particle as a Platform Technology

Vaults are naturally occurring nanoparticles found widely in eukaryotes. The particles can be produced in large quantities and are assembled in situ from multiple copies of the single structural protein following expression. Using molecular engineering, recombinant vaults can be functionally modified and targeted, and their contents can be controlled by packaging. Here, we review the development of engineered vaults as a platform for a wide variety of therapeutic applications and we examine future directions for this unique nanoparticle system.
Determination of mycophenolic acid and its phenol glucuronide metabolite in human plasma and urine by high-performance liquid chromatography

Simultaneous determination of mycophenolic acid (MPA) and mycophenolate phenol glucuronide (MPAG) in plasma and urine was accomplished by isocratic HPLC with UV detection. Plasma was simply deproteinated with acetonitrile and concentrated, whereas urine was diluted prior to analysis. Linearity was observed from 0.2 to 50 microg/ml for both MPA and MPAG in plasma and from 1 to 50 microg/ml of MPA and 5 to 2000 microg/ml MPAG in urine with extraction recovery from plasma greater than 70%. Detection limits using 0.25 ml plasma were 0.080 and 0.20 microg/ml for MPA and MPAG, respectively. The method is more rapid and simple than previous assays for MPA and MPAG in biological fluids from patients.
Potential value of diffusing capacity per liter of lung volume (DL/VA) for early detection of alveolar capillary defects.

In four healthy people, one man and three women, we showed that the diffusing capacity per unit alveolar volume during the test (DL/VA) tends to become constant when the lung volume during breathholding is above 80% total lung capacity. If more extensive studies confirm that, at lung volumes above 80%, values for DL/VA for healthy people fall within a narrower range than values for DL itself, then DL/VA may be the method of choice in detecting diseases affecting the alveolar capillaries at an early stage. We also confirmed that the 10 s single breath test is independent of possible regional inhomogeneities during breathholding.
A UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase is essential for viability in Drosophila melanogaster.

We report the first demonstration that the activity of a member of the UDP-GalNAc:polypeptideN-acetylgalactosaminyltransferase gene family is necessary for viability in Drosophila melanogaster. Expression of the wild-type recombinant pgant35A gene in COS7 cells resulted in in vitro activity against peptide and glycopeptide substrates, demonstrating that this gene encodes a biochemically active transferase. Previous mutagenesis studies identified recessive lethal mutations that were rescued by a genomic fragment containing thepgant35A gene; however, the presence of additional open reading frames within this fragment left open the possibility that another gene was responsible for rescue of the observed lethality. Here, we have determined the molecular nature of the mutations in three independent mutant alleles. Two of the mutant alleles contain premature stop codons within the coding region of pgant35A. The third mutant contains an arginine to tryptophan amino acid change, which, when expressed in COS7 cells, resulted in a dramatic reduction of transferase activity in vitro. PCR amplification of this gene from Drosophila cDNA panels and Northern analysis revealed that it is expressed throughout embryonic, larval, and pupal stages as well as in adult males and females. This study provides the first direct evidence for the involvement of a member of this conserved multigene family in eukaryotic development and viability.
Direct Detection of Residual Cyanide in Cassava Using Spectroscopic Techniques

Fluorescence, infrared, scanning electron microscopy (SEM), UV–visible, and X-ray diffraction (XRD) techniques have been applied to monitor the effect of processing mode on the residual cyanogens in cassava roots. The processed samplesʼ infrared spectra have shown that only the boiled sample contains residual cyanide. SEM micrographs have revealed that irregularly shaped granules of about 100-μm size contain cyanide, while spherical granules of about 10-μm size do not. X-ray diffraction patterns have shown that the intensities of peaks are not affected by the presence of cyanide in the cassava samples. Fluorescence and UV–visible studies have detected the presence of cyanide converted to cyanate in water used for soaking processes. The thermal behavior of cassava samples with respect to the cyanide content and the role of oxygen and different ions present in water used for soaking processes are also discussed.