cssi/SciSciGPT-SciSciNet huggingface dataset:
A Comparison of Reliability of Soil Cadmium Determination by Standard Spectrometric Methods

Inductively coupled plasma emission spectrometry (ICP-OES) is the most common method for determination of soil Cd, yet spectral and matrix interferences affect measurements at the available analytical wavelengths for this metal. This study evaluated the severity of the interference over a range of total soil Cd by comparing ICP-OES and inductively coupled plasma mass spectrometry (ICP-MS) measurements of Cd in acid digests. Using the emission at 226.5 nm, ICP-OES was generally unable to quantify soil Cd at low (near-background) levels and gave unreliable values compared with ICP-MS. Using the line at 228.8 nm, a marked positive bias in Cd measurement (relative to the 226.5 nm measurement) was attributable to arsenic (As) interference even at soil As concentrations below 10 mg kg. This spectral interference in ICP-OES was severe in As-contaminated orchard soils, giving a false value for soil total Cd near 2 mg kg when soil As was 100 to 150 mg kg. In attempting to avoid these ICP emission-specific interferences, this study evaluated a method to estimate total soil Cd using 1 M HNO extraction followed by determination of Cd by flame atomic absorption (FAA), either with or without preconcentration of Cd using an Aliquat-heptanone extractant. The 1 M HNO extracted an average of 82% of total soil Cd. The FAA method had no significant interferences and estimated the total Cd concentrations in all soils tested with acceptable accuracy. For Cd-contaminated soils, the Aliquat-heptanone preconcentration step was not necessary, as FAA sensitivity was adequate for quantification of extractable soil Cd and reliable estimation of total soil Cd.
Desiccant-Induced Esophageal Obstruction: An Emerging Patient Safety Issue

A desiccant is a hygroscopic substance that absorbs water to preserve and protect products from the effects of moisture over time, often used with supplements and medications. They may have similar appearance, size, and shape to the desired medication or supplement. We present a case of an esophageal foreign body obstruction caused by unintentional ingestion of a desiccant. A 75-year-old man with history of GERD complicated by esophageal stricture presented with 24 hours of solid-phase dysphagia, which began after taking vitamins without any unusual ingestion. Upper endoscopy revealed a cylindrically shaped foreign body in the distal esophagus, approximately 2.0 x 1.0 x 1.0 cm in size, which was removed with a Roth net (US Endoscopy, Mentor, OH) and identified as a pill bottle desiccant (Figure 1). An underlying distal esophageal stricture was discovered and dilated with resolution of symptoms.
Non-clastogenicity in mouse bone marrow of fructose/lysine and other sugar/amino acid browning products with in vitro genotoxicity.

Heated sugar/amino acid reaction mixtures, known to contain products that are clastogenic and/or mutagenic to cells in vitro, were evaluated for clastogenic activity in mouse bone marrow using the erythrocyte micronucleus assay. Heated (i.e. browned) fructose/lysine reaction mixtures were also evaluated in the Salmonella his-reversion assay and the Chinese hamster ovary (CHO) cell chromosomal aberration assay to confirm and extend previous in vitro observations. Significant mutagenicity of fructose/lysine mixtures was observed in Salmonella typhimurium strains TA100, TA2637, TA98 and TA102, with greater activity in mixtures heated at pH 10 than at pH 7. S-9 decreased the activity in strains TA100, TA2637 and TA98, but increased the activity in strain TA102. Both pH 7 and pH 10 reaction mixtures of the fructose/lysine browning reaction were highly clastogenic in CHO cells. Heated mixtures of fructose and lysine, and of glucose or ribose with lysine, histidine, tryptophan or cysteine, did not increase the frequency of micronucleated erythrocytes in mice when administered by the oral route. This indicates the absence of chromosomal aberrations in erythrocyte precursor cells, and indicates that the genotoxic components of the browned mixtures are not absorbed and distributed to bone marrow cells in amounts sufficient to induce micronuclei when given orally. Because sugar/amino acid browning reactions occur commonly in heated foods, it is important to evaluate further the in vivo genotoxicity of browning products in cell populations other than bone marrow.
Obstructive non-woven fiber barriers for reducing red-winged blackbird damage to sweet corn

Abstract Red-winged blackbirds (Agelaius phoeniceus L.) annually destroy substantial amounts of sweet corn (Zea mays L.) during the summer. No-choice feeding trials were conducted to assess the efficacy of spraying sweet corn ears with obstructive polymer fibers (ethylene vinyl acetate, EVA) as a means of reducing damage by blackbirds. Experiments were conducted with captive blackbirds and standing sweet corn between 18 September and 10 October 1997 and 1998. Relative to control ears, fiber treatment reduced the percentage of ears with husk damage by 10–12% (P
EVIDENCE FOR THE REACTION OF A LONG-LIVED MONOTYPIC SPECIES OF IODINE IN THE GAS PHASE

A monotypic long-lived radioactive iodine of123I or125I resulting from the123I or125Xe(EC)125I nuclear transformation, respectively, is described. The iodine species has the characteristics thought peculiar to the hydrated halogen that participates in certain concerted termolecular halogen-halogen reactions. The reaction leading to123ICl or125ICl in gas phase substrates of Cl2, NOCl, HCl and CCl4 was studied.
Cytochrome oxidase subunit II gene is adjacent to an initiator methionine tRNA gene in soybean mitochondrial DNA

The nucleotide sequence of the cytochrome oxidase subunit II (COII) gene from soybean mitochondria reveals a high degree of sequence conservation to other plant COII sequences. The greatest homology is to pea (97.9%) and the homology extends for some distance both 5′ and 3′ from the gene. Upstream from the breakpoint in homology with the pea sequence there is a tRNA gene identified as the initiator methionine by homology to known plant tRNA genes. The COII coding sequence appears to be present at a single location in the soybean mitochondrial genome, however some portion of the 5′ flanking region is repeated at other sites in the genome. The transcription from the cloned region is complex and is complicated by the presence of the repeated sequence.
Heuristics, tools, and systems for evaluating Internet information: helping users assess a tangled Web

This paper discusses facilitated Internet evaluation, explores heuristics, tools and systems that have been developed to help users evaluate Internet information. Delineates a taxonomy for these systems, and offers descriptive information and sample tools representative of each category.
Structural Determinants of Tau Aggregation Inhibitor Potency

Small-molecule Tau aggregation inhibitors are under investigation as potential therapeutic agents against Alzheimer disease. Many such inhibitors have been identified in vitro, but their potency-driving features, and their molecular targets in the Tau aggregation pathway, have resisted identification. Previously we proposed ligand polarizability, a measure of electron delocalization, as a candidate descriptor of inhibitor potency. Here we tested this hypothesis by correlating the ground state polarizabilities of cyanine, phenothiazine, and arylmethine derivatives calculated using ab initio quantum methods with inhibitory potency values determined in the presence of octadecyl sulfate inducer under reducing conditions. A series of rhodanine analogs was analyzed as well using potency values disclosed in the literature. Results showed that polarizability and inhibitory potency directly correlated within all four series. To identify putative binding targets, representative members of the four chemotypes were added to aggregation reactions, where they were found to stabilize soluble, but SDS-resistant Tau species at the expense of filamentous aggregates. Using SDS resistance as a secondary assay, and a library of Tau deletion and missense mutants as targets, interaction with cyanine was localized to the microtubule binding repeat region. Moreover, the SDS-resistant phenotype was completely dependent on the presence of octadecyl sulfate inducer, but not intact PHF6/PH6* hexapeptide motifs, indicating that cyanine interacted with a species in the aggregation pathway prior to nucleus formation. Together the data suggest that flat, highly polarizable ligands inhibit Tau aggregation by interacting with folded species in the aggregation pathway and driving their assembly into soluble but highly stable Tau oligomers. Background: Mechanistic insight into small-molecule Tau aggregation inhibitors is needed for their advancement as therapeutic agents. Results: Structure-activity relationship analysis identified polarizability as a common descriptor of inhibitor potency. Conclusion: Flat, highly polarizable ligands stabilize soluble oligomeric complexes at the expense of filamentous aggregates. Significance: The findings suggest a basis for rational improvement of ligand potency, whereas maintaining bioavailability.
Effect of ring-constrained phenylpropyloxyethylamines on sigma receptors

A series of ring-constrained phenylpropyloxyethylamines, partial opioid structure analogs and derivatives of a previously studied sigma (σ) receptor ligand, was synthesized and evaluated at σ and opioid receptors for receptor selectivity. The results of this study identified several compounds with nanomolar affinity at both σ receptor subtypes. Compounds 6 and 9 had the highest selectivity for both σ receptor subtypes, compared to μ opioid receptors. In addition, compounds 6 and 9 significantly reduced the convulsive effects of cocaine in mice, which would be consistent with antagonism of σ receptors.
Blurring the boundary: convergence of factory and service processes

Purpose – In order to emphasize the universality of operations management concepts, this paper develops an integrative view of the similarities and continuities between “services products” and operations; and “goods products” and factory operations. The purpose of this paper is to move toward a better understanding of the impact of this convergence.Design/methodology/approach – By reviewing the literature and trade press examples of evolution in both manufacturing and services businesses, it develop a model for understanding the observed phenomena.Findings – This paper finds that services operations are continually adopting the characteristics of traditional manufacturing as they seek to grow and gain increased profitability through economies of scale. At the same time, traditional manufacturing/factory operations continually seek to differentiate themselves by offering more services such as customization, flexibility, and just‐in‐time; without giving up their economies of scale. As goods and services pro...
Quantum Effects Strongly Influence the Surface Premelting of Ice

Clear evidence is presented that quantum effects in the motion of the H2O molecules strongly influence the surface premelting of ice. To reveal this behavior, structural and dynamical properties of the ice surface below the melting point were calculated using quantum molecular dynamics with an ab initio based force field. The quantum calculations predict the existence of a quasi-liquid-phase that extends for approximately 10 A into the bulk, in agreement with the values obtained by optical ellipsometry experiments. Importantly, surface disorder in the topmost layers of the quantum ice persists at temperatures that are about 10−20 °C lower than its classical counterpart, indicating that the surface premelting of ice may largely be a result of quantum effects over a wide range of temperatures.
The electrophoretic mobility of cholesterol.

Abstract 1. 1. Cholesterol suspensions were subjected to continuous particle electrophoresis and were found to show an electrophoretic migration. This phenomenon was studied further to determine the comparative extent of the migration and the factors influencing it. 2. 2. Cholesterol migrated to the same extent as stearic acid but farther than phosphatidyl ethanolamine, cardiolipin, phosphatidyl serine or phosphatidyl choline. Cholesteryl esters exhibited only about one-half the mobility of cholesterol. Mixtures of cholesterol with other lipids showed mobilities intermediate between the mobilities of their individual components. 3. 3. The electrokinetic properties of cholesterol were dependent on the presence of polyatomic anions and differed with two methods of preparation. 4. 4. The result suggest that there is an adsorption of ions, particularly anions, to cholesterol. The degree of adsorption is influenced by the availability of the hydroxyl group of cholesterol and the surface nature of the cholesterol.
Styles of parenting among parents of young gifted children

There has been little research on styles of parenting among parents of young gifted children. This lack of information about parenting styles makes it difficult to develop an effective parent component for preschool progress for the gifted. This study compared the attitudes, values, and behavior of 39 parents of young gifted and nongifted children. The results indicated that while there were many similarities among these two groups of upper‐middle‐class parents, parents of the gifted tended to spend considerably more time with their child on school related activities, they were more likely to report unconditional love for their child while being more willing to encourage their child to be independent.
Tracking Invasive Land Covers in India or Why Our Landscapes Have Never Been Modern

The effects of rationalization and bureaucratization on the landscape are myriad and contradictory. The unforeseen environmental consequences resulting from modern planning create new geographies far beyond those of the planner’s design. This article explores the land-cover effects of state-sponsored modernization efforts in the semiarid Godwar region of Rajasthan, India. Using satellite imagery, historical data, household production information, and the discourse of state planners, the research described here explores the land covers that result from agricultural intensification, biodiversity preservation, and resource conservation in postindependence development. The study demonstrates that through these efforts, state planners have attempted to physically partition those land uses seen as “social” from those seen as “natural” and thereby enforce a modernist purification of land covers. Despite these efforts—indeed, because of them—hybrid and “impure” land covers, which mix social and natural characteri...
A systematic approach to vertebral hemangioma

Vertebral hemangiomas (VHs) are a frequent and often incidental finding on computed tomography (CT) and magnetic resonance (MR) imaging of the spine. When their imaging appearance is "typical" (coarsened vertical trabeculae on radiographic and CT images, hyperintensity on T1- and T2-weighted MR images), the radiological diagnosis is straightforward. Nonetheless, VHs might also display an "atypical" appearance on MR imaging because of their histological features (amount of fat, vessels, and interstitial edema). Although the majority of VHs are asymptomatic and quiescent lesions, they can exhibit active behaviors, including growing quickly, extending beyond the vertebral body, and invading the paravertebral and/or epidural space with possible compression of the spinal cord and/or nerve roots ("aggressive" VHs). These "atypical" and "aggressive" VHs are a radiological challenge since they can mimic primary bony malignancies or metastases. CT plays a central role in the workup of atypical VHs, being the most appropriate imaging modality to highlight the polka-dot appearance that is representative of them. When aggressive VHs are suspected, both CT and MR are needed. MR is the best imaging modality to characterize the epidural and/or soft-tissue component, helping in the differential diagnosis. Angiography is a useful imaging adjunct for evaluating and even treating aggressive VHs. The primary objectives of this review article are to summarize the clinical, pathological, and imaging features of VHs, as well as the treatment options, and to provide a practical guide for the differential diagnosis, focusing on the rationale assessment of the findings from radiography, CT, and MR imaging.
Characterization of house fly microsomal mixed function oxidases: Inhibition by juvenile hormone I and piperonyl butoxide

Abstract The microsomal mixed function oxidase system of the house fly ( Musca domestica [L.]) was characterized with respect to N -demethylation of p -chloromethylaniline, O -demethylation of methoxyresorufin, epoxidation of aldrin and the formation of a metabolite-cytochrome P -450 complex during oxidation of piperonyl butoxide (PB). The inhibition of these reactions by juvenile hormone I ( E,E cis methyl 10, 11-epoxy-7-ethyl-3,11-dimethyl-2,6-tricecadienoate JH-I) was competitive for the N -demethylase, epoxidase and the formation of the PB metabolite-complex. Non-competitive inhibition was observed for the O -demethylase. The inhibition of these reactions by JH-I provides evidence that the mixed function oxidase system participates in the degradation of juvenile hormone, and that the juvenile hormone-like properties of PB and other methylenedioxyphenyl compounds are derived from their inhibition of this degradation. The PB metabolite-cytochrome P -450 complex has 2 absorbance maxima in the reduced form (427 and 455 nm), and a single absorbance maximum in the oxidized form (438 nm). pH affected the extinction of the 427 and 455 nm absorbance bands. The pH equilibrium point was 8.3 for the reduced PB metabolite complex, and 9.5 for ethylisocyanide. In addition, the PB metabolite complex could be generated in vivo.
μCT‐Based Measurement of Cortical Bone Graft‐to‐Host Union

Evaluation of structural bone grafts risk of failure requires noninvasive quantitative predictors of functional strength. We hypothesized that a quantitative graft-to-host union biometric would correlate significantly with biomechanical properties as a surrogate for the risk of fracture. To test this, we developed a novel algorithm to compute the union between host callus and graft, which was termed the union ratio. We compared the union ratio of live autografts to devitalized allografts implanted into the mid-diaphysis of mouse femurs for 6 and 9 wk. Surprisingly, the autograft union ratio decreased from 0.228 ± 0.029 at 6 wk to 0.15 ± 0.011 at 9 wk (p < 0.05) and did not correlate with the torsional properties of the autografts . The allograft union ratio was 0.105 ± 0.023 at 6 wk but increased to 0.224 ± 0.029 at 9 wk (p < 0.05). As a single variable, the union ratio correlated significantly with ultimate torque (R 2 = 0.58) and torsional rigidity (R 2 = 0.51) of the allografts. Multivariable regression analyses of allografts that included the union ratio, the graft bone volume, the maximum and minimum polar moment of inertia, and their first-order interaction terms with the union ratio as independent variables resulted in significant correlations with the ultimate torque and torsional rigidity (adjusted R 2 = 0.80 and 0.89, respectively). These results suggest that, unlike live autografts, the union between the devitalized allograft and host contributes significantly to the strength of grafted bone. The union ratio has important clinical implications as a novel biometric for noninvasive assessment of functional strength and failure risk.
Glare spot image calculations for a spherical particle illuminated by a tightly focused beam

A theoretical model is presented for coherent imaging of a spherical aerosol particle illuminated by an arbitrary incident electromagnetic field propagating obliquely with respect to the imaging system axis (i.e., off-axis imaging). Analytical simplification of the theoretical development is presented for the important special case of plane-wave illumination. The modeling technique uses the arbitrary beam theory, presented by the authors in an earlier paper [ J. Appl. Phys.64, 1632 ( 1979)], to calculate the external electromagnetic field resulting from the interaction of the incident field with the aerosol particle. Scalar diffraction theory is used to propagate the dominant electric field component through the imaging lens and to the image plane. Glare spot calculations generated by using the theoretical model are presented for both opaque and transparent particles with size parameters (ratios of circumference to wavelength) ≈ 94 illuminated by both off-axis focused-beam- and plane-wave-incident fields. For transparent aerosols in this size range, the glare spot images are dominated by the specular reflection peak and the edge glare spot that results from light incident at grazing angles. Glare spot experimental data obtained for tightly focused pulsed laser (λ = 610–630 nm, tpulse ≈ 150 fs, 2w0 ≈ 20 μm) illumination of 70-μm-diameter water droplets showed qualitative agreement with beam calculations performed with the theoretical model. Theoretical images corresponding to partial-wave-resonance conditions showed a radial shift in the location of the glare spot peaks as well as an increase in glare spot intensities.
Estimates of suspended-sediment flux and bedform activity on the inner portion of the Eel continental shelf

Energetic waves, strong bottom currents, and relatively high rates of sediment discharge from the Eel River combined to produce large amounts of suspended-sediment transport on the inner continental shelf near the Eel River during the winter of 1995–1996. Bottom-boundary-layer (BBL) measurements at a depth of ∼50 m using the GEOPROBE tripod showed that the strongest near-bottom flows (combined wave and current speeds of over 1 m/s) and highest sediment concentrations (exceeding 2 g/l at ∼1.2 m above the bed) occurred during two storms, one in December 1995 and the other in February 1996. Discharge from the Eel River during these storms was estimated at between 2 and 4×103 m3/s. Suspended-sediment flux (SSF) was measured 1.2 m above the bed and calculated throughout the BBL, by applying the tripod data to a shelf sediment-transport model. These results showed initially northward along-shelf SSF during the storms, followed by abrupt and persistent southward reversals. Along-shelf flux was more pronounced during and after the December storm than in February. Across-shelf SSF over the entire measurement period was decidedly seaward. This seaward transport could be responsible for surficial deposits of recent sediment on the outer shelf and upper continental slope in this region. Sediment ripples and larger bedforms were observed in the very fine to fine sand at 50-m depth using a sector-scanning sonar mounted on the tripod. Ripple wavelengths estimated from the sonar images were about 9 cm, which compared favorably with photographs of the bottom taken with a camera mounted on the tripod. The ripple patterns were stable during periods of low combined wave–current bottom stresses, but changed significantly during high-stress events, such as the February storm. Two different sonic altimeters recorded changes in bed elevation of 10 to 20 cm during the periods of measurement. These changes are thought to have been caused principally by the migration of low-amplitude, long-wavelength sand waves into the measurement area.
PARAMETRIC MODELS OF HURRICANE-GENERATED WINDS, WAVES AND CURRENTS IN DEEP WATER

Three parametric models are developed to estimate winds, waves, and currents generated by hurricanes in water depths greater than 100m. The models are derived from state of the art numerical models. Comparisons between the parametric models and their ancestors suggest that the parametric models perform well for the majority of storms. For example, the RMS difference among the models is 2 m/s for wind speed, 1m for significant wave height, and o cm/s for currents. These differences are well within the accuracy needed for operations and preliminary design.
Stability of steady state solutions to a hydrodynamic model of semiconductors

We discuss the stability of steady state solutions for a hydrodynamic model of semiconductors. We study the case where the doping profile is close to a positive constant and depends on the spacial variable x. We shall show that the steady state solution is asymptotically stable with respect to small perturbations in H2(R).© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Affiliation with deviant peers among children of substance dependent fathers from pre-adolescence into adolescence: associations with problem behaviors

Objective: Affiliation with delinquent peers has been shown to be a major risk factor for the development of antisocial and substance abuse behaviors in adolescence. However, little data are available concerning the developmental trajectories of deviant peer affiliation. Method: In this study, we have prospectively examined the density of deviant peers among the social networks of children of drug dependent fathers at age 10, and at 2 and 5 year follow-ups, and compared them with those of controls. Measures of internalizing and externalizing psychopathology were employed as time varying covariates, while socioeconomic status (SES) was used as a time invariant covariate. A pattern mixture analysis of missing data was conducted. Results: Using mixed effects models, we found significant main effects of time, group, externalizing psychopathology, and to lesser extent, SES on the magnitude of affiliation with deviant peers. Greater deviant peer affiliation among the high-risk children was found at each time point. Externalizing psychopathology augmented the magnitude of deviant peer affiliation in both high-risk and comparison children. Conclusion: Offspring of drug dependent fathers have heightened affiliation with deviant peers from pre-adolescence through mid-adolescence. This social developmental process may be a component of the familial risk for substance abuse and antisocial behaviors.
On higher‐order asymptotic factorization of non‐linear operators

Operator splitting for evolution equations which involve non-linear differential operators is investigated. The occurrence of third-orderaccurate multifactor splittings which are characterized by all-positive fractional steps and which involve at most four factors is discovered. This result is surprising, as a recent investigation by Sheng (1989), of evolution equations involving general linear operators, establishes that no third-orderaccurate factional-step splitting having all-positive fractional steps exists, regardless of the number of factors attempted. However, the present investigation indicates it is unlikely that Sheng's result has much bearing on the existence of positive-step splittings for non-linear equations. In addition to the result mentioned above, with n = 3, 4, 5, another case is exhibited of a non-linear equation which permits all-positive step, n-thorder splittings requiring only n + 1 factors. Indeed, a pathological case is examined of a partial differential equation with an annihilating operator which permits k-factor, nth-order splittings, for k > 1 and n > 1. Thus, for the non-linear case, one should expect only the unexpected. Finally, the idea of equivalent splittings for linear aganist non-linear equations is considered. For a particular equation, all splittings having five factors or less, which are obtained by considering a linearization are shown applicable also to the non-linear case. However, there exists a four-factor all-positive step splitting of the non-linear equation which is not discovered by the linearized approach.
Multi-cavity pressure control in the filling and packing stages of the injection molding process

Cavity pressure has been recognized as a critical process parameter for the injection molding of high quality plastic parts. Recent developments in injection molding process technology have enabled closed loop control of cavity pressure at one point in the mold. In this paper, a scheme is described that enables the simultaneous control of cavity pressure at multiple locations in both multi-gated parts and/or multi-cavity molds. This has been achieved by the addition of dynamic valves in the melt delivery system, each of which can be independently controlled to meter the flow and pressure of the polymeric melt to its portion of the mold. The development and capabilities of the control system are presented, demonstrating the feasibility of simultaneous multi-cavity pressure control in both the filling and packing stages of the injection molding process. A description of the ability of multi-cavity pressure control to improve process capability and molded part quality is presented in a companion paper.
Managing GRAIL: Getting to launch on cost, on schedule, and on spec

The Gravity Recovery And Interior Laboratory (GRAIL) mission launched September 2011. GRAIL is a Discovery Program mission with a project cost cap. Led by Principal Investigator (PI) Dr. Maria T. Zuber of MIT and managed by NASA's Jet Propulsion Laboratory, GRAIL will precisely map the gravitational field of the Moon to reveal its internal structure “from crust to core,” determine its thermal evolution, and extend this knowledge to other planets. Dr. Sally Ride leads education and public outreach. This paper summarizes development challenges and accomplishments. Critical success factors are discussed, including key personnel, technical margins, and schedule/cost management practices.1
Cancellation of equilibrium parity-violating currents

It has recently been shown that in a rotating equilibrium system there exist neutrino and antineutrino currents parallel to the rotation axis. This suggests that particles other than neutrinos can also develop equilibrium currents if parity-violating weak interactions are taken into account. This possibility is examined using quantum field theory at finite temperature, density, and angular velocity. Regularization and renormalization of such a theory are discussed. The result obtained is negative. It is found that in the model considered the equilibrium current vanishes in the lowest order of perturbation theory. This is a surprising result, since the existence of a nonzero current is not forbidden by the symmetries of the Lagrangian. The question naturally arising from this result is whether a nonzero current appears in higher orders of perturbation theory or in different models or there is some deep physical reason which makes the equilibrium current equal to zero for all particles except neutrinos.
Position-dependent theory of heterojunctions

Heterojunction band discontinuities determined by any of the traditional rigid-band models show discrepencies between theory and experiment of at least ±4 kT. In contrast, a new position-dependent model based on a more extensive study, (described briefly here) gives agreement with direct measurements to within ± 1kT. In addition, there is a strong correlation with the discontinuity values obtained from Schottky barrier height measurements, although – as expected – this correlation becomes poorer as the lattice or dielectric constant mismatch incieases. Banddiskontinuitaten von Heteroubergangen, die mit irgendeinem der traditionellen starren Bandmodelle bestimmt werden, ergeben Diskrepanzen zwischen Theorie und Experiment von wenigsten ±4 kT. Im Gegensatz dazu ergibt ein neues positionsabhangiges Modell (das hier kurz beschrieben wird) auf der Grundlage einer ausfuhrlicheren Untersuchung Ubereinstimmung mit direkten Messungen innerhalb ±1kT. Zusatzlich existiert eine strenge Korrelation mit den Diskontinuitatswerten, die aus Schottkybarrierenhohenmessungen erhalten werden, obwohl – wie erwartet – diese Korrelation schwacher wird, wenn die Gitteroder Dielektrizitatskonstanten-fehlanpassung wachst.
Eiger: A framework for the automated synthesis of statistical performance models

As processor architectures continue to evolve to increasingly heterogeneous and asymmetric designs, the construction of accurate performance models of execution time and energy consumption has become increasingly more challenging. Models that are constructed, are quickly invalidated by new features in the next generation of processors while many interactions between application and architecture parameters are often simply not obvious or even apparent. Consequently, we foresee a need for an automated methodology for the systematic construction of performance models of heterogeneous processors. The methodology should be founded on rigorous mathematical techniques yet leave room for the exploration and adaptation of a space of analytic models. Our current effort toward creating such an extensible, targeted methodology is Eiger. This paper describes the methodology implemented in Eiger, the specifics of Eiger's extensible implementation and the results of one scenario in which Eiger has been applied — the synthesis of performance models for use in the simulation-based design space exploration of Exascale architectures.
Differentiation of Physarum flavicomum: Metabolic patterns and the role of amino acids in the control of encystment

Haploid myxamoebae-swarm cells of Physarum flavicomum , grown in semidefined medium, differentiated in a nonnutrient salts solution to produce dormant microcysts. Over 90% of the original cell population converted to microcysts after 72 h of incubation. The intracellular content of protein, neutral hexose and RNA decreased significantly during encystment, but the DNA content was relatively stable. A change in metabolic patterns occurred during differentiation since encysting cells, but not growing cells, actively catabolized protein amino acids. Whether encystment progressed or not was determined by the extracellular availability of certain amino acids. The condition of amino acid imbalance and not glucose availability initiated the differentiation of the vegetative cells to microcysts. Only the branched chain aliphatic amino acids, leucine, isoleucine, and valine (in that order), were significant determinants of the encystment process. The compounds which inhibited encystment also inhibited intracellular proteolysis. Radioactive amino acids were actively taken up from the salts solution by encysting cells and incorporated into protein. Proteins formed in the early stages of encystment were degraded to a certain extent as encystment proceeded. However, [ 14 C]leucine-labeled proteins produced by encysting cells were degraded and catabolized less than those labeled with [ 14 C]isoleucine and [ 14 C]valine.
Detection and handling of MAC layer misbehavior in wireless networks

Wireless Medium Access Control (MAC) protocols such as IEEE 802.11 use distributed contention resolution mechanisms for sharing the wireless channel. In this environment, selfish hosts that fail to adhere to the MAC protocol may obtain an unfair share of the channel bandwidth. For example, IEEE 802.11 requires nodes competing for access to the channel to wait for a “backoff” interval, randomly selected from a specified range, before initiating a transmission. Selfish nodes may wait for smaller backoff intervals than well-behaved nodes, thereby obtaining an unfair advantage. We present modifications to the IEEE 802.11 protocol to simplify detection of such selfish hosts. We also present a correction scheme for penalizing selfish misbehavior. Simulation results indicate that our detection and correction schemes are successful in handling MAC layer misbehavior.
Knee injury in skiing A multifaceted approach

During the past four ski seasons, all 1,141 ski injuries which occurred in a large northern Vermont ski area were evaluated prospectively. Of these injuries, 21.6% involved knee ligaments and 18.6% involved sprains of the medial collateral ligament. Females sustained a disproportionately high incidence of Grade I medial collateral sprains, but suffered the more severe sprains at a rate similar to that of males. Individuals who were smaller, younger, less experienced, and less skilled sustained a higher incidence of Grade I injuries. Skiers suffering complete tears of the medial collateral ligament were no smaller, younger, or less skilled or experienced than our control population. Medial collateral sprains are produced primarily by external rotation and valgus forces. Two-mode release bindings are insensitive to several loading configurations which could produce knee sprains. Bindings which allow release in roll, shear, and twist at the heel, as well as twist at the toe and forward lean, appear to be necessary to protect the knee.
Evaluation of a preprimed microporous hollow-fiber membrane for rapid response neonatal extracorporeal membrane oxygenation:

Delays in initiating extracorporeal membrane oxygenation (ECMO) in the critically ill pediatric patient may lead to adverse outcomes. Maintaining a primed ECMO circuit can considerably reduce the initiation time. The predominant concerns precluding this practice are a decrease in oxygenator efficiency due to the saturation of microporous hollow fibers and compromised sterility when the oxygenator has been primed for 30 days. For institutions using a hollow-fiber oxygenator for ECMO, there are no data reporting pre-primed hollow-fiber oxygenator viability. This study reports the efficiency of oxygen transfer and the sterility of the Carmeda Minimax Plus (Medtronic, Inc, Minneapolis, MN) oxygenator after being crystalloid primed for 30 days. A total of 10 Minimax Plus oxygenators were tested for oxygen transfer in a laboratory setting utilizing fresh whole bovine blood. The control group (n=5) were tested immediately after priming. The test group (n=5) were oxygenators primed for 30 days with crystalloid so...
Network-based modular latent structure analysis.

Background High-throughput expression data, such as gene expression and metabolomics data, exhibit modular structures. Groups of features in each module follow a latent factor model, while between modules, the latent factors are quasi-independent. Recovering the latent factors can shed light on the hidden regulation patterns of the expression. The difficulty in detecting such modules and recovering the latent factors lies in the high dimensionality of the data, and the lack of knowledge in module membership.
Reconstitution of catecholamine-stimulated binding of guanosine 5'-O-(3-thiotriphosphate) to the stimulatory GTP-binding protein of adenylate cyclase.

The stimulatory GTP-binding protein (G,) of adenylate cyclase, purified from rabbit liver, and 0-adrenergic receptors, partially purified 1000-4000-fold from turkey erythrocyte plasma membranes, were coreconstituted into unilamellar phospholipid vesicles. The molar ratio of G, to receptors in the vesicles varied from 3 to 10 in different preparations, as measured by guanosine 5'-0-(3-(3sS)thio- triphosphate) ( (3SS)GTPyS) binding to G, and ('2sI)iodo- cyanopindolol binding to receptors. Activation of reconstituted G, by GTPyS was stimulated up to 10-fold by the addition of the @-adrenergic agonist (-)-isoproterenol. Activation was assayed functionally by reconstitution with the catalytic unit of adenylate cyclase. Because of the relative purity of this preparation, the quasi-irreversible binding of (3sS)GTPyS could also be measured in the vesicles and was shown to parallel the functional activation of G, under all conditions. Most of the assayable G, in the vesicles could interact with the receptors and undergo agonist-stimulated activation. Agonist-stimulated activation and (35S)GTPyS binding were complete in less than 3 min, even under suboptimal conditions,
Civic Community Approaches to Rural Development in the South: Economic Growth with Prosperity

and increasing rates of inconie inequalily. B~~ckecl by recent scholarship and grassroots n~ovements that suggest that both civic engagement and the presence of srnaller-scale, locally c.ontrolled cntespsihes can help determine whether comin~~nities prosper or tlecline, this paper explores the links between social struct~rre and rural clevelopment in the South. The goal is to expand our understanding of civic community theory as an alternative to the neoclassical economic motlel of clcvelopment. Using a local PI-oblem-solving framework. we suggest that a departure from the traditio~~al, neoclassical path of de\.elopment is in order. We conclucie that r~~ral policy makers must establish a role for civic community in the ru1.211 development process if they wish to pl-otccr the welfare of workers and cornm~~nities. while increa\ing the prospects of economic growth with prosperity. Kt,?. Wort1.c.: civic community. economic growth, rural development, social capital, Southern United States
Endometrial cancer in women 40 years old or younger.

Abstract Objective. The aim of this study was to characterize endometrial cancer in women 40 years of age and younger, with special attention toward body-mass index (BMI). Methods. A retrospective review of women age 40 and under with endometrial cancer was performed. Patients were identified via tumor registry data as well as a search of pathology department diagnoses over the dates 1980–1998. Data were abstracted regarding tumor grade and histology, stage, treatment, smoking, use of oral contraceptives, BMI, medical and family history, parity, and survival. Data were also collected with regard to uterine conservation and pregnancies following endometrial cancer diagnoses. Results. Ninety-five patients were identified. The age range was 24–40 years (median 37) with BMI ranging from 17.5 to 63.6 (median 28.4). Forty-eight patients (52%) were not obese, with BMI P = 0.04) and more likely to have high-risk histology ( P = 0.02). Of the 4 patients with high-risk histology (clear cell or serous papillary), all had BMI Conclusion. Women under 40 who are not obese are at higher risk of both advanced disease and high-risk histology. Further study at the molecular and genetic level is ongoing in our laboratory to determine whether the mechanism of disease is different in slender woman.
Critical Issues Literacy Connections between School and Home: How Should We Evaluate Them?

The value of a partnership between teachers and parents in the promotion of children's literacy appears self-evident. It symbolizes both the school's accountability to the community it serves and the complementary responsibility of families to support the school's agenda of empowering their children with the tools of civilization. Many parents and teachers across the world perceive, however, that there is something amiss with the relations between them. On the one hand, they share an interest in the literacy development of the same children, and in some sense, they subscribe to an implicit contract to share responsibility for promoting it. Yet, disagreement frequently arises about how this contract is to be executed in practice. In this eclectic review of research, I consider three complementary ways in which the nature of the connection between children's homes and the schools they attend can be problematized, each focusing on a different criterial dimension for evaluating the home-school connection: (a)...
A vertical dispersion model for solute exchange induced by underflow and periodic hyporheic flow in a stream gravel bed

[1] Interstitial flows in stream gravel beds are driven by stream slope and controlled by hydraulic conductivity (underflows) or induced by pressure differentials on the streambed surface (hyporheic flows). They enhance solute exchange between surface water and a streambed. To study the solute transport in a stream gravel bed, a 2-D transient advection–dispersion mass transfer model was formulated. The velocity field includes an underflow and a spatially periodic hyporheic flow, e.g., due to standing surface waves or bed forms. Two dimensionless scaling parameters emerged: R measures the relative strength of hyporheic flow to underflow in the streambed and λ is the ratio of dispersivity of the gravel bed to the pressure wavelength along the streambed. In the analysis of mass transfer of nonconservative substances into a streambed, an explicit 2-D analysis of interstitial flow is often undesirable. Therefore the numerical solutions for the 2-D concentration fields under periodic boundary conditions were reduced to 1-D vertical concentration profiles (by streamwise averaging of the solute concentrations). The profiles were matched to the solution of an unsteady vertical 1-D dispersion equation that introduces a depth variable “enhanced dispersion coefficient DE(y)” that lumps all forms of interstitial advective and dispersive transport in the streambed. Functions DE(y) were determined for many combinations of independent parameters by inverse modeling, and the dependence of DE(y) on the dimensionless parameters R and λ was determined from these results. Analytical relationships for DE(y, R, λ) have been proposed and validated against available experimental data. Knowledge of DE(y) allows the estimation of solute/mass transfer rates in streambeds under wavy boundary conditions, without explicit analysis of the interstitial flow. This is a distinct advantage for applications in stream water quality and/or pore water quality studies.
Improved detection of rotavirus shedding by polymerase chain reaction.

Abstract To improve identification of children excreting rotavirus a method for the amplification of rotavirus RNA by the polymerase chain reaction (PCR) was developed. The assay was compared with a solid-phase enzyme immunoassay in the detection of rotavirus shedding by infants in hospital during the winter peak of rotavirus infections. Forty children were studied in an intermediate care unit after transfer from intensive care units. Only two were admitted primarily because of diarrhoea; the other thirty-eight were admitted for management of various other disorders. Rotavirus shedding was detected by enzyme immunoassay in twenty of the infants, and nine of these (aged 1 week to 8 months) remained in hospital for more than 5 days after the initial detection of rotavirus and could be studied long term. Of 103 faecal samples from the nine infants, 60 (58%) contained rotavirus RNA detected by reverse-transcriptase (RT)/PCR, whereas only 37 (36%) were positive for rotavirus antigen by the immunoassay (χ 2 =10·3, p
Stable expression and characterization of N-terminal tagged recombinant human bone morphogenetic protein 15

Oocyte-derived growth factors are critically involved in multiple ovarian processes via paracrine actions. Although recombinant proteins have been applied to dissect the physiological functions of these factors, variation of activities among different protein preparations remains an issue. To further elucidate the roles of one of these growth factors, bone morphogenetic protein 15 (BMP15), in mediating oocyte-regulated molecular and cellular events and to explore its potential clinical application, we engineered the human BMP15 sequence to efficiently produce bioactive recombinant human BMP15 (rhBMP15). The proteolytic cleavage site of the hBMP15 precursor was optimized to facilitate the production of the mature protein, and a FLAG-tag was placed at the N-terminus of the mature region to ease purification and avoid potential interference of the tag with the cystine knot structure. The rhBMP15 protein was purified using anti-FLAG M2 affinity gel. Our results demonstrated that the N-terminal tagged rhBMP15 was efficiently processed in HEK-293 cells. Furthermore, the purified rhBMP15 could activate SMAD1/5/8 and induce the transcription of genes encoding cumulus expansion-related transcripts (Ptx3, Has2, Tnfaip6 and Ptgs2), inhibitory SMADs (Smad6 and Smad7), BMP antagonists (Grem1 and Fst), activin/inhibin βA (Inhba) and βB (Inhbb) subunits, etc. Thus, our rhBMP15 containing a genetically modified cleavage sequence and an N-terminal FLAG-tag can be efficiently produced, processed and secreted in a mammalian expression system. The purified rhBMP15 is also biologically active and very stable, and can induce the expression of a variety of mouse granulosa cell genes.