cssi/SciSciGPT-SciSciNet huggingface dataset:
High-temperature defect structure of Nb-doped LaCrO3

Abstract Electrical conductivity and Seebeck measurements on LaCr0.98Nb0.02CrO3 show that the defect structure of the material is mainly controlled by the extrinsic electrons formed by the Nb donors through the electronic compensation process. The experimental results also indicate that this material conducts electricity via a small polaron mechanism with an electron mobility around 0.004–0.01 cm2/V sec between 1100 and 1300°C.
MicroRNAs in facial development.

Cranial neural crest cell migration is a prerequisite for normal craniofacial morphogenesis in animals. A new study shows that the movement of a specific subset of cranial neural crest cells is exquisitely sensitive to concentrations of a microRNA that targets platelet-derived growth factor receptor alpha mRNA.
A renaissance in engineering PhD education

This paper addresses the role of engineering PhD education and its relationship to innovation and technology, and the need to reconsider how we educate PhD engineers. Much of the effort on engineering education in the last two decades focused on undergraduate education with a few exceptions that relate to masterdegree programs. Doctoral education in engineering prepares the next generation faculty, researchers, and technology leaders and warrants our attention. Whilst current education has been largely responsible for technological advances, there is a need for a new model of engineering PhD education that prepares renaissance engineers. This paper focuses on the doctoral education and its role in the USA; however, the issues addressed are universal among the countries that offer PhD degrees in engineering.
Spontaneous and vaccine induced AFP-specific T cell phenotypes in subjects with AFP-positive hepatocellular cancer

We are investigating the use of Alpha Fetoprotein (AFP) as a tumor rejection antigen for hepatocellular carcinoma (HCC). We recently completed vaccination of 10 AFP+/HLA-A2.1+ HCC subjects with AFP peptide-pulsed autologous dendritic cells (DC). There were increased frequencies of circulating AFP-specific T cells and of IFNgamma-producing AFP-specific T cells after vaccination. In order to better understand the lack of association between immune response and clinical response, we have examined additional aspects of the AFP immune response in patients. Here, we have characterized the cell surface phenotype of circulating AFP tetramer-positive CD8 T cells and assessed AFP-specific CD4 function. Before vaccination, HCC subjects had increased frequencies of circulating AFP-specific CD8 T cells with a range of naive, effector, central and effector memory phenotypes. Several patients had up-regulated activation markers. A subset of patients was assessed for phenotypic changes pre- and post-vaccination, and evidence for complete differentiation to effector or memory phenotype was lacking. CD8 phenotypic and cytokine responses did not correlate with level of patient serum AFP antigen (between 74 and 463,040 ng/ml). Assessment of CD4+ T cell responses by ELISPOT and multi-cytokine assay did not identify any spontaneous CD4 T cell responses to this secreted protein. These data indicate that there is an expanded pool of partially differentiated AFP-specific CD8 T cells in many of these HCC subjects, but that these cells are largely non-functional, and that a detectable CD4 T cell response to this secreted oncofetal antigen is lacking.
Early postoperative appearance of radiofrequency lesions on magnetic resonance imaging.

ABSTRACTELEVEN PATIENTS WHO underwent stereotactic radiofrequency lesions in the central nervous system had magnetic resonance imaging follow-up within 72 hours of surgery to determine the early appearance of their lesions. Eight patients with severe tremor, one with chronic pain, and two with dysto
Properties of the reversible nonoxidative vanillate/4-hydroxybenzoate decarboxylase from Bacillus subtilis.

Bacillus subtilis (ATCC 6051) reversibly decarboxylates vanillate and 4-hydroxybenzoate under both aerobic and anoxic conditions. Thus, we have identified on the basis of gene sequence homology wit...
Fibrinolytic enzyme(s) in western diamondback rattlesnake (Crotalus atrox) venom

Abstract Western diamondback rattlesnake ( Crotalus atrox ) venom has been shown to have significant fibrinolytic activity and no visible fibrinogen clotting activity. The fibrinolytic enzyme(s) estimated by fibrin plate assay, exhibited optimal activity at pH 7·5. Molecular sieve chromatography on Sephadex G-100 revealed that fibrinolytic activity was equally distributed between two protein peaks having mol. wts of 60,000 and 21,500.
Detection of Uric Acid Stones in the Ureter Using Low- and Conventional-dose Computed Tomography

Objective To determine the ability of low- and conventional-dose computed tomography (CT) in identification of uric acid stones, which are of lower density than calcium oxalate stones. Materials and Methods Uric acid stones (3, 5, and 7 mm) were randomly placed in human cadaveric ureters and scanned using conventional 140-mAs and low-dose 70-, 50-, 30-, 15-, 7.5-, and 5-mAs settings. A single-blinded radiologist reviewed a total of 523 scanned stone images. Sensitivity and specificity were compared among different settings and stone sizes. Results Imaging using 140-, 70-, 50-, 30-, 15-, 7.5-, and 5-mAs settings resulted in 97%, 97%, 96%, 93%, 83%, 83%, and 69% sensitivity and 92%, 92%, 91%, 89%, 88%, 91%, and 94% specificity, respectively. There was a significant difference in sensitivity between 140 mAs and 15, 7.5, and 5 mAs ( P = .011, P = .011, and P P Conclusion Both low- and conventional-dose CTs demonstrate excellent sensitivity and specificity for the detection of ureteral uric acid stones. However, low-dose CT at ≤15 mAs resulted in reduced detection of uric acid stones.
Noble gases and coupled heat/fluid flow modeling for evaluating hydrogeologic conditions of volcanic island aquifers

summary Understanding groundwater conditions in the upland parts of volcanic island aquifers is critical for sustainable groundwater development in these resource-limited environments. Yet groundwater conditions in such settings are generally difficult to characterize because of sparse well drilling (high cost and/or limited access). Information needed for resource evaluation includes upland depth to water, recharge rate, and aquifer permeability. In this study, noble-gas recharge temperatures and coupled heat/fluid flow modeling are used to indirectly infer these groundwater conditions. Mosteiros Basin on Fogo Island of the Cape Verde archipelago was selected as a representative volcanic island aquifer. Simulation results are calibrated to water-table altitude and temperature data, along with indirect information provided by noble and dissolved gases. Results of numerical modeling are most sensitive to recharge rates and hydraulic conductivity, less sensitive to basal heat flux, and not sensitive to porosity and thermal conductivity. Simulation results show that only a relatively narrow range of combined recharge values (12–25% of precipitation) and hydraulic conductivity (10 � 8 –10 � 7 ms
The ionization behavior of retinoic acid in aqueous environments and bound to serum albumin.

The ionization behavior of retinoic acid (RA) in an aqueous phase and when bound to bovine serum albumin was studied. Titrations of RA in the various phases were followed by monitoring the red shift in the absorption maximum of RA that occurred upon deprotonation. The apparent pK of RA was dependent on the concentration of this compound. At the concentration range 6–20 μM, the pK of RA in water had a value of approximately 8.0. As the concentration was decreased in the range 1–6 μM, the value of the pK decreased continuously. The lowest pK observed was approximately 6.0. It was concluded that RA in an aqueous phase at concentrations in the μM range, forms micelles, and that the values of the pK of RA monomers and micelles in water are 9.5.
Affinity Enhancement Pretargeting: Synthesis and Testing of a 99mTc-Labeled Bivalent MORF

Pretargeting with bivalent effectors capable of bridging antitumor antibodies (affinity enhancement pretargeting) has been reported to provide superior results by affinity enhancement. Phosphorodiamidate morpholinos (MORFs) and other DNA analogues used for pretargeting are ideally suited as bivalent effectors since they are easily synthesized and the distance between binding regions, a determinant of binding, may be adjusted simply by lengthening the chain. We have shown by surface plasmon resonance that bivalent MORFs will provide superior affinity enhancement provided that suitable spacing exists between the binding regions. The goals of this study were to synthesize a bivalent MORF with a MAG3 group attached for technetium-99m (99mTc) radiolabeling, investigate whether the bivalent MORF showed improved cell accumulation in culture compared to its corresponding monovalent MORF and compare biodistributions in normal mice and in pretargeted tumored mice. An excess of an amine derivatized 18 mer MORF with ...
Rapid, pulse counting low‐energy electron diffraction instrument

A low‐energy electron diffraction instrument has been constructed which allows one to visually observe a LEED pattern, record the pattern photographically and obtain immediate, quantitative intensity data from several diffraction beams in 5–10 s. The instrument operates at incident beam currents of a few picoamperes eliminating electron beam damage effects. This paper describes the design and construction of this new LEED instrument and reports on the operating parameters of sensitivity, signal‐to‐noise, image distortion, and angular resolution.
A bat rabies isolate with an unusually short incubation period

Abstract Rabies viruses from two types of bats were inoculated intracerebrally into laboratory mice. The reactions of the mice differed markedly. Those inoculated with virus from a Mexican freetail bat, Tadarida brasiliensis mexicana , died a violent death after an incubation of 4 to 5 days. The pathology was marked, with much neuronal destruction noted. Those mice inoculated with virus from a vampire bat, Desmodus rotundus , died after incubation periods similar to those noted after inoculation of common “street” viruses, i.e., 7 days or more. The pathology corresponded to the limited amount usually seen after death from “street” virus.
Vibration fringes by phase stepping on an electronic speckle pattern interferometer: an analysis

A detailed analysis of the vibration fringes obtained by phase stepping on a time-averaged electronic speckle pattern interferometer is presented. It is shown that the contrast of the fringes remains relatively high for any phase step between 30° and 180° for low electronic noise and fringe density. Also, for the four-phase-stepped method, the vibration fringes have the same contrast as that of the π-phase-shift method except that the high-frequency speckles are smoothed. The contrast of the fringes obtained with extra phase steps along with incoherent superimposition is shown to be higher than the single- or four-phase-step method. Both theory and experimental results are presented.
Optic-Flow-Based Collision Avoidance

Flying in and around caves, tunnels, and buildings demands more than one sensing modality. This article presented an optic-flow- based approach inspired by flying insects for avoiding lateral collisions. However, there were a few real-world scenarios in which optic flow sensing failed. This occurred when obstacles on approach were directly in front of the aircraft. Here, a simple sonar or infrared sensor can be used to trigger a quick transition into the hovering mode to avoid the otherwise fatal collision. Toward this end, we have demonstrated a fixed-wing prototype capable of manually transitioning from conventional cruise flight into the hovering mode. The prototype was then equipped with an IMU and a flight control system to automate the hovering process. The next step in this research is to automate the transition from cruise to hover flight.
Reply to comment on “The structure of monolayer SiO 2 on Mo(1 1 2): A 2-D [Si O Si] network or isolated [SiO 4 ] units?”

1 For a tetrahedral of [SiO4], the asymmetrical vibrations of Si–O should always be IR active. Unfortunately, these modes were assumed to be IR inactive in Refs. [5,6]. 2 In Refs. [5,6], TO modes were calculated and compared with those obtained from IRAS using p-polarized and grazing incidence IR light [3– 6]. However, it is well-established that for dielectric thin films only the TO mode is observed in transmission and reflection IR using normal incident light. On the other hand both the TO and LO modes are observed with grazing incident light, with the intensity of the LO mode increasing with an increase in the grazing angle [10,13–18]. Furthermore, the intensity of the LO mode is enhanced significantly using p-polarized light [16]. For an ultra-thin oxide film on a metallic substrate, the intensity of the LO mode has been shown to be enhanced and the TO mode concomitantly reduced First, in response to the above Comment [1] it is important to consider the following experimental observations: (i) high resolution electron energy loss spectroscopy (HREELS) [2] and infrared reflection adsorption spectroscopy (IRAS) [3–6] show intense asymmetric vibrational modes related to Si–O–Mo (1048 cm 1 in HREELS and 1056–1059 cm 1 in IRAS), whereas no active asymmetric vibrational modes related to Si–O–Si (1176 cm 1 in HREELS and 1200–1250 cm 1 in IRAS) are in evidence for SiO2(1 ML)/Mo(112), (see Fig. 1). These data indicate the absence of Si–O–Si species, i.e. the presence of isolated [SiO4] units [2], or that the axis of the bonding in the Si– O–Si moities are essentially parallel to the substrate surface. Regarding the latter point, however, off-specular HREELS [7] shows no evidence for an asymmetric vibrational feature related to Si–O–Si in SiO2(1 ML)/Mo(112); (ii) ultraviolet photoelectron spectroscopy (UPS) shows only a single feature at a binding energy of 10.5 eV, corresponding to an oxygen species in the Si–O–Mo linkage, with no evidence of a feature at or near 11.5 eV related to the oxygen species in the Si–O–Si linkage [4]; (Note that there should be two oxygen species, Si–O–Mo and Si–O–Si, in the 2-D network.) (iii) a detailed STM investigation of SiO2(1 ML)/Mo(112) [7] shows a single spot in each c(2 · 2) unit and/or four spots (one clearly distinct from the other three) with a (1 · 1) arrangement. In particular the one distinct spot in each c(2 · 2) unit is inconsistent with the proposed 2-D network model but is consistent with the isolated [SiO4] structure.
A model of charge transport and electromechanical transduction in ionic liquid-swollen Nafion membranes

Abstract Ionomeric polymer transducers (sometimes called “ionic polymer–metal composites,” or “IPMCs”) are a class of electroactive polymers that are able to operate as distributed electromechanical actuators and sensors. Traditionally, these transducers have been fabricated using water-swollen Nafion membranes. This work seeks to overcome the hydration dependence of these transducers by replacing water with an ionic liquid. In the current work, two ionic liquids are studied as diluents for ionomeric polymer transducers based on Nafion membranes. The two ionic liquids used are 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMI-Tf) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-Im). These two ionic liquids were chosen for their low viscosity and high conductivity. Furthermore, although many of the physical properties of the two ionic liquids are similar, the EMI-Tf ionic liquid is water miscible whereas the EMI-Im ionic liquid is hydrophobic. These important similarities and differences facilitated investigations of the interactions between the ionic liquids and the Nafion polymer. This paper examines the mechanisms of electromechanical transduction in ionic liquid-swollen transducers based on Nafion polymer membranes. Specifically, the morphology and relevant ion associations within these membranes are investigated by the use of small-angle X-ray scattering (SAXS), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. These results reveal that the ionic liquid interacts with the membrane in much the same way that water does, and that the counterions of the Nafion polymer are the primary charge carriers in the ionic liquid-swollen films. The results of these analyses are compared to the macroscopic transduction behavior in order to develop a molecular/morphological model of the charge transport mechanism responsible for electromechanical coupling in these membranes.
ras mutations in human leukemia and related disorders.

The clinical association of an increased incidence of acute myelogenous leukemia (AML) with previous chemoradiotherapy, the detection of specific karyotypic changes in these secondary (therapy-induced) cases of AML and the discovery of increasing levels of oncogene-specific RNA in leukemia cells suggest that one potential site of action of environmental agents might be the proto-oncogenes in human hematopoietic stem cells. The location of human proto-oncogenes at the sites of chromosome breaks and/or translocations in cells from some patients with leukemia or lymphoma is a striking observation. These data stimulated research into the mechanism of activation of specific oncogenes that change the biology of human hematopoietic cells. Recent investigations have focused upon several areas that might alter cell biology including: 1) translocation and/or inversion of chromosome fragments containing a proto-oncogene to a location where other gene sequences can stimulate oncogene activation, 2) replication of copy number of proto-oncogenes or increased transcriptional activity and 3) point mutation in proto-oncogenes leading to a structurally altered protein. The third area of research has recently received significant attention with respect to the potential role of three ras genes (c-Harvey-rar, c-Kirsten-ras and N-ras) in human leukemias and myelodysplastic syndromes. Recent studies have proposed a model for leukemogenic transformation of human hematopoietic cells by the product of a mutated ras oncogene. Mutations at codons 12, 13 or 61 of the first exon of its 4.7 Kb of DNA (for c-Ha-rar) have been described. Other data revealing an absence of such mutations in the ras genes of many human leukemias and the absence of detectable transcription of ras genes in many alkylating agent-associated cases of AML, suggest that while ras mutations may be involved in some settings, there are probably multiple genetic pathways to leukemogenic transformation of human hematopoietic cells.
Neuroblastoma: management, recurrence, and follow-up.

Neuroblastoma is a neoplasm that affects infants and children with significant mortality and morbidity. Efforts at population-based screening have increased disease detection, but have failed to reduce mortality. The clinical behavior is highly variable, depending on the patient's age, disease stage, and histopathologic findings. Research also has identified molecular markers that are useful in predicting disease aggressiveness and prognosis. By categorizing patients into risk groups, it is possible to optimize treatment and follow-up strategies. Low-risk patients may be amenable to observation or surgery alone, whereas multidisciplinary treatment protocols are needed in those with advanced disease and relapses. Although outcomes of patients with advanced disease remain poor, novel developments in research and treatment protocols are ongoing and hold promise to improved outcomes.
Whole-body MR angiography using variable density sampling and dual-injection bolus-chase acquisition

Conventional bolus-chase acquisition generates peripheral runoff images using a single injection of the contrast material. Low spatial resolution, small slice coverage and venous contamination are major problems especially in the distal stations. A technique is presented herein in which whole-body magnetic resonance angiography is performed using a dual-contrast-injection four-station acquisition protocol. Bolus sharing was performed between two stations: the abdomen and calf stations share the first bolus injection, while the thorax and thigh stations share the second bolus injection. The combination of variable density sampling and elliptical centric acquisition order was applied to the abdomen and thorax stations. The scan time was extended to generate high spatial resolution arterial phase images with broad slice coverage for the calf and thigh stations. The feasibility of this technique was demonstrated using phantom and in vivo human volunteer studies.
Chlamydia trachomatis does not bind to αβ1 integrins to colonize a human endometrial epithelial cell line cultured in vitro

Abstract Chlamydia trachomatis is the leading cause of bacterially acquired sexually transmitted diseases in the United States and Europe. As an obligate intracellular pathogen, this bacterium must invade epithelial cells in order to survive and grow. Thus, multiple strategies probably exist for initial binding of chlamydiae to their target cells. Since a variety of bacteria have exploited integrins to colonize tissues, and a precedent existed for the involvement of extracellular matrix components in chlamydial attachment, this study first analyzed, by flow cytometry, integrins expressed by the human endometrial epithelial cell line HEC-1B. The genital cells were then exposed to monoclonal antibodies directed against those integrins and assayed for chlamydial attachment and inclusion development. Monoclonal antibodies bound to the and/or β1 subunit of classic integrin receptors displayed by HEC-1B cells were not able to prevent colonization and infection of the epithelial cells by a genital isolate of C. trachomatis.
Apparent vascular occlusion on cranial TOF MRA with peripheral presaturation technique.

OBJECTIVE Improvement in the visibility and accurate representation of intracranial vessels may be achieved on cranial time-of-flight (TOF) MR angiography (MRA) when the signal intensity of orbital and superficial fat is suppressed. This may be accomplished by placement of spatial radiofrequency presaturation bands along the periphery of the head. The objective of this study was to evaluate the potential for this peripheral presaturation technique to result in a spurious appearance of vascular occlusion. MATERIALS AND METHODS Three-dimensional TOF MRA of the head was performed in three patients. Flow-compensated spoiled gradient echo images were acquired in the transaxial plane, using the peripheral presaturation technique. The MRA acquisitions were then subsequently repeated in each patient following retraction of the peripheral presaturation bands. A phantom study was also performed to assess the slice profile of the presaturation bands. RESULTS There was absence of flow-related enhancement, indicating apparent vascular occlusion, involving one carotid siphon in each patient on initial MRA images. Following lateral retraction and/or removal of presaturation bands, the carotid siphons were documented to be patent, with normal caliber and flow-related enhancement demonstrated. Image analysis and phantom experiments indicate this vascular pseudoocclusion is due to proximity of the lateral presaturation band to the lateral aspect of the petrous segment of the internal carotid artery. In this location, there is inadvertent saturation of flowing spins due to imperfections in the presaturation band slice profile. CONCLUSION The use of peripheral presaturation bands for cranial TOF MRA is useful for improving vascular depiction. However, patent vessels may occasionally demonstrate an absent signal intensity, suggesting occlusion when this technique is used. Awareness of this diagnostic pitfall is important so that serious misdiagnosis does not occur.
Age modulates the effect of COMT genotype on delay discounting behavior

A form of impulsivity, the tendency to choose immediate over delayed rewards (delay-discounting) has been associated with a single nucleotide polymorphism (SNP) in the catechol-O-methyltransferase (COMT) gene (COMTval 158 met; rs4680). However, the existing data regarding the nature of this association are in conflict. We have previously reported that adults homozygous for valine (val) at the COMTval 158 met SNP demonstrate greater delay-discounting than do methionine (met) allele carriers (Boettiger et al., J Neurosci 27:14383–14391, 2007). In contrast, a recent study of adolescent males found that those with the met/met genotype demonstrate greater delay-discounting than do val-allele carriers (Paloyelis et al., Neuropsychopharmacology 35:2414–2426, 2010). Based on reported age-related changes in frontal dopamine function and COMT expression, we hypothesized that the association of COMT genotype with delay-discounting behavior is modulated by age from late adolescence to young adulthood. To test this hypothesis, we genotyped late adolescents (18–21 years; n = 72) and adults (22–40 years; n = 70) for the COMTval 158 met polymorphism, measured their delay-discounting behavior, and tested for an interaction between age group and COMT genotype. This cross-sectional study found that age modulates COMTval 158 met genotype effects on delay-discounting behavior. Among met-carriers, delay-discounting was negatively correlated with age from late adolescence to adulthood, while among val/val individuals delay-discounting was positively correlated with age across this range. These results confirm our previous finding of enhanced delay-discounting among val/val adults relative to met-allele carriers, and help reconcile existing literature. We propose a single U-shaped model of the relationship between frontal DA levels and impulsive choice that accounts for both adolescent and adult data.
Specific acetylation of essential lysine residues in malonyl-CoA decarboxylase

Abstract 1. 1. Malonyl-CoA decarboxylase from the uropygial gland of goose was inactivated by treatment with low concentrations of acetic anhydride in Tris-acetate buffer. 2. 2. The degree of inactivation depended on the concentration of the reagent and time of incubation. 3. 3. Treatment of the enzyme with [1- 14 C]acetic anhydride resulted in covalent attachment of the label exclusively to the decarboxylase protomer. 4. 4. Evidence is presented that the label incorporated into the protein was exclusively in N -ϵ-acetyllysine. Graphical analysis suggested that acetylation of about two lysine residues/subunit would be required for complete inactivation of the enzyme. 5. 5. Malonyl-CoA. acetyl-CoA, propionyl-CoA and methylmalonyl-CoA afforded partial protection to the enzyme against inactivation by acetic anhydride. 6. 6. 3'-Dephosphomalonyl-CoA was found to be an alternate substrate for the enzyme with approximately the same K m and V values as for malonyl-CoA. 7. 7. This alternate substrate also partially protected the enzyme from inactivation, whereas adenine nucleotides with 2'-, 3'-, or 5'-phosphates did not protect the enzyme. 8. 8. These results suggest that a lysine residue acetylated by acetic anhydride is essential for the enzyme activity and that it is probably at or near the active site. The results are consistent with the suggestion that the enzyme is composed of four identical subunits.
Testing Math Competency in Introductory Economics

In this paper, I examine how a math-competency requirement affects student performance in an introductory economics course. Students were given a basic math-competency quiz at the beginning of the semester. Those who did not pass could receive remedial-math tutoring and retake the competency quiz. The results of this study indicate that students who passed the math-competency quiz, regardless of the number of attempts, performed significantly better in the class than students who did not attain basic math skills.
Metal-silicate silicon isotope fractionation in enstatite meteorites and constraints on Earth's core formation

article Silicon has long been considered a possible light element in Earth's core. If differences in 30 Si/ 28 Si ratios between metal (core) and silicate (mantle and crust) can be quantified, silicon isotopes may be used to constrain the amount of this element in the core, and in so doing elucidate the conditions that attended Earth's differentiation. We investigate Si-isotope fractionation between metal and silicate in metal-rich enstatite meteorites as an analogue for Earth's differentiation. We report here a 5 to 6‰ difference in the 30 Si/ 28 Si ratio between Si in metal and Si in silicate in the aubrites (enstatite achondrites) Mount Egerton and Norton County. The meteorites are believed to have derived from enstatite chondrites by melting and thermal metamorphism with final equilibration at 1200 and 1130±80 K, respectively. Using the measured silicate-metal Si-isotope fractionation in these rocks we obtain a temperature dependence for fractionation of Δ30Sisilicatemetal = 7:64 × 10 6 F0:47 1σ ðÞ T2 , in agreement with independent experimental and theoretical determinations. The measured silicate-metal fractionation suggests a ∼0.8‰ difference in the 30 Si/ 28 Si ratio between Earth's core and mantle at P/T conditions relevant to core formation. Our results, based on thermodynamic calculations for Si solubility in iron-rich metal and the measured Si-isotopic silicate-metal fractionation, imply at least ∼6 wt.% Si in the core (depending on the exact Δ
Data locality-based mesh partitioning methods for dataflow machines

Power efficiency became an important factor in High Performance Computing (HPC). FPGA-based dataflow machines are the best candidates for power efficient computing, because of the maximized memory bandwidth utilization, and user-defined optimal caching. However, input data streams are required with optimized data locality. This paper focuses on the possibilities of novel mesh partitioning techniques, which provide partitions with better data locality.
The Medium Creation and the Message

The article reviews the book "The Transformation of American Industrial Relations," by Thomas A. Kochan, Harry C. Katz, and Robert B. McKersie.
College broadcasting courses: Two symposia

At some time in the future it may be that broadcasting will become a profession with an agreed upon preparatory course of study. At the present time, not only is there a lack of uniformity in cours...
Optimal stochastic flow control in a high speed virtual circuit

The author addresses the problem of flow control in a high-speed network. The network is modeled as a single virtual circuit consisting of several queues in tandem. Traffic from other queues is modeled as cross-traffic that reduces the available capacity at each queue. A fluid-flow model of the virtual circuit is employed, where the cross-traffic at each queue is a random process consisting of a Markov sequence of values, with shifts in value occurring at points of time described by a pure birth process. Shifts in cross-traffic are assumed to occur only occasionally, so that the control can be considered in the context of a single shift occurring at time zero. The problem of finding the network access control that minimizes the expected delay due to backlogs is shown to be an isoperimetric problem, and the form of the solution is found. Under the additional assumption that shifts in cross-traffic at a queue take on a sequence of independent values, the solution of the Euler equation is shown to have a very simple form. The results are illustrated with a numerical example. >
A comprehensive stability analysis of a cracked beam subjected to follower compression

Abstract A comprehensive analysis of the stability of a cracked beam subjected to a follower compressive load is presented. The beam is fixed at its left end and restrained by a translational spring at its right end. The vibration analysis on such cracked beam is conducted to identify the critical compression load for flutter or buckling instability based on the variation of the fist two resonant frequencies of the beam. Besides, the effect of the crack's intensity and location on the buckling or flutter compressive load is studied through comprehensive mechanics analysis. It is hoped that this research may provide a benchmark on the stability analysis of cracked structures in engineering applications, especially for structures subjected to follower compressive load.
Neutrophils are essential for containment of Vibrio cholerae to the intestine during the proinflammatory phase of infection

Cholera is classically considered a noninflammatory diarrheal disease, in comparison to invasive enteric organisms, although there is a low-level proinflammatory response during early infection with Vibrio cholerae and a strong proinflammatory reaction to live attenuated vaccine strains. Using an adult mouse intestinal infection model, this study examines the contribution of neutrophils to host defense to infection. Nontoxigenic El Tor O1 V. cholerae infection is characterized by the upregulation of interleukin-6 (IL-6), IL-10, and macrophage inflammatory protein 2 alpha in the intestine, indicating an acute innate immune response. Depletion of neutrophils from mice with anti-Ly6G IA8 monoclonal antibody led to decreased survival of mice. The role of neutrophils in protection of the host is to limit the infection to the intestine and control bacterial spread to extraintestinal organs. In the absence of neutrophils, the infection spread to the spleen and led to increased systemic levels of IL-1β and tumor necrosis factor alpha, suggesting the decreased survival in neutropenic mice is due to systemic shock. Neutrophils were found not to contribute to either clearance of colonizing bacteria or to alter the local immune response. However, when genes for secreted accessory toxins were deleted, the colonizing bacteria were cleared from the intestine, and this clearance is dependent upon neutrophils. Thus, the requirement for accessory toxins in virulence is negated in neutropenic mice, which is consistent with a role of accessory toxins in the evasion of innate immune cells in the intestine. Overall, these data support that neutrophils impact disease progression and suggest that neutrophil effectiveness can be manipulated through the deletion of accessory toxins.
Carboxyl-terminal determinants of Abelson protein important for lymphoma induction.

Abstract The carboxyl-terminal region of the Abelson protein is not absolutely required for Abelson virus transformation. However, Abelson virus strains encoding proteins missing portions of this region have a reduced ability to transform lymphoid cells in vitro and in vivo. One such strain, called P90A, is unique in that P90A-injected mice almost always develop tumors containing highly oncogenic variants that encode new forms of Abelson protein. In this work, we have examined the mechanism by which these variants are generated and used the variants to identify carboxyl-terminal protein sequences important for the induction of Abelson disease. Analysis of mice injected with helper-free P90A virus stocks demonstrates that the variants are generated during viral replication in vivo, probably as a consequence of error-prone reverse transcription. The sequence of the P90A viral genome reveals that a 19-base deletion is responsible for synthesis of the truncated Abelson protein. As a consequence of this mutation, 167 carboxyl-terminal amino acids normally found in the wild-type protein have been replaced by 33 amino acids derived from an alternative reading frame. Site-directed mutants show that the combination of the deletion and the P90A carboxyl terminus is required for the generation of variants. Thus, the particular structure of the P90A protein, not the specific residues lost or gained, alters the transforming potential of the Abelson protein. Finally, the sequence of the variants encoding smaller Abelson proteins reveals that as few as 452 v-abl-encoded amino acids are required for rapid induction of Abelson disease.
Dynamic vehicle routing with moving demands - Part I: Low speed demands and high arrival rates

We introduce a dynamic vehicle routing problem in which demands arrive uniformly on a segment and via a temporal Poisson process. Upon arrival, the demands translate perpendicular to the segment in a given direction and with a fixed speed. A service vehicle, with speed greater than that of the demands, seeks to serve these translating demands. For the existence of any stabilizing policy, we determine a necessary condition on the arrival rate of the demands in terms of the problem parameters: (i) the speed ratio between the demand and service vehicle, and (ii) the length of the segment on which demands arrive. Next, we propose a novel policy for the vehicle that involves servicing the outstanding demands as per a translational minimum Hamiltonian path (TMHP) through the moving demands. We derive a sufficient condition on the arrival rate of the demands for stability of the TMHP-based policy, in terms of the problem parameters. We show that in the limiting case in which the demands move much slower than the service vehicle, the necessary and the sufficient conditions on the arrival rate are within a constant factor.
Cholinergic Modulation of Associative Memory Function in a Realistic Computational Model of Piriform Cortex

A detailed biophysical model of piriform cortex developed with the GENESIS simulation package shows associative memory properties such as completion. This model allows analysis of how the neuromodulatory effects of acetylcholine influence cortical associative memory function. Experiments in brain slice preparations demonstrate that acetylcholine causes selective suppression of synaptic transmission at excitatory intrinsic fiber synapses in piriform cortex [1]. When applied during learning in the model, this selective cholinergic suppression prevents interference between overlapping patterns of afferent input, allowing separate and distinct learning of input stimuli.
Studies of the chemical modifications of wool and their effects on the wool–water relationship. Part II. Wool‐water relationships of modified and unmodified wool

The wool–water relationships of the modified wools prepared as described in Part I of this series have been studied. The drained water content of fabric and the solution isotherms and diffusion constants of water vapor into untreated and modified wools have been measured. Most of the treated wool fabrics showed considerable decreases in the drained water contents compared with the untreated wool. However, the degree of improvement depended markedly on the conditions of modification, particularly with the styrene grafted materials. In some cases values close to those of a comparable polypropylene fabric were found. The sorption isotherms also showed that the modifications reduced, substantially in some cases, the regains even when calculated on the wool content only. The diffusion constants were difficult to measure because of the heats of sorption causing temperature changes during the sorption; however, at lower regains this effect could be corrected. It was found that both the direct chemical modification and the grafted wools showed a diffusion behavior which was more characteristic of hydrophobic materials in that the diffusion constants tended to decrease with increasing concentration. At low humidities the diffusion constants were larger than in the untreated wool, but at higher humidities lower diffusivities were found with the modified wools.
High small-signal modulation bandwidth and narrow linewidth microdisk lasers

In this report, microdisk lasers with -3dB small-signal modulation bandwidths in excess of 17 GHz are demonstrated. Linewidth of these lasers are also measured and a minimum linewidth of 85 MHz is achieved.
Frequent Users of Rural Primary Care: Comparisons With Randomly Selected Users

BACKGROUND Frequent users of primary care have not been adequately characterized. The unique characteristics of this population was sought--why they come so often, what their care costs, and whether psychosocial factors play a role in their high utilization of health care. METHODS The billing system of a rural primary care clinic was used to find the frequency of visits for all patients attending the clinic for the previous 12 months. The 211 most frequent visitors were selected. A comparison group of 250 patients was drawn from the billing records using a random number generator. Charts were reviewed to compare diagnoses (by frequency), number of procedures, amount billed for care, amount received from those billings, number of psychotropic medications prescribed, and response to medication. A subgroup of each group was interviewed to confirm chart review findings and to inquire about personal reasons for coming to the clinic. RESULTS Compared with patients who were random users, patients who were frequent users were more likely to come from the younger and older age groups, they averaged significantly more emergency department visits and visits to other specialists (P < 0.0001), and they had more mental health problems diagnosed (P < 0.01). Significantly more frequent users were insured by Medicaid and fewer were insured by Medicare. They had more detailed office visits and more laboratory tests. They received twice as much psychotherapy and had a higher percentage of problem-focused office visits. Chart audits and interviews of selected patients revealed that many nonmedical reasons were related to visits in addition to psychosocial stressors. CONCLUSIONS Nonmedical factors are important among the most frequent users of a primary care clinic. Proposals to improve care for frequent users should consider the psychosocial needs of this population.
Stiffness discrimination with visual and proprioceptive cues

This study compares the Weber fraction for human perception of stiffness among three conditions: vision, proprioceptive motion feedback, and their combination. To make comparisons between these feedback conditions, a novel haptic device was designed that senses the spring behavior through encoder and force measurements, and implements a controller to render linear virtual springs so that the stimuli displayed haptically could be compared with their visual counterparts. The custom-designed, torque-controlled haptic interface non-invasively controls the availability of proprioceptive motion feedback in unimpaired individuals using a virtual environment. When proprioception is available, the user feels an MCP joint rotation that is proportional to his or her finger force. When proprioception is not available, the actual finger is not allowed to move, but a virtual finger displayed graphically moves in proportion to the user's applied force. Visual feedback is provided and removed by turning on and off this graphical display. Weber fractions were generated from an experiment in which users examined pairs of springs and attempted to identify the spring with higher stiffness. To account for slight trial-to-trial variations in the relationship between force and position in the proprioceptive feedback conditions, our analysis uses measurements of the actual rendered stiffness, rather than the commanded stiffness. Results for 10 users give average Weber fractions of 0.056 for vision, 0.036 for proprioception, and 0.039 for their combination, indicating that proprioception is important for stiffness perception for this experimental setup. The long-term goal of this research is to motivate and develop methods for proprioception feedback to wearers of dexterous upper-limb prostheses.
Spaceborne observations of the 2000 Bezymianny, Kamchatka eruption: the integration of high-resolution ASTER data into near real-time monitoring using AVHRR

Abstract Since its launch in December 1999, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument has been observing over 1300 of the world's volcanoes during the day and night and at different times of the year. At the onset of an eruption, the temporal frequency of these regularly scheduled observations can be increased to as little as 1–3 days at higher latitudes. However, even this repeat time is not sufficient for near real-time monitoring, which is on the order of minutes to hours using poorer spatial resolution (>1 km/pixel) instruments. The eruption of Bezymianny Volcano (Kamchatkan Peninsula, Russia) in March 2000 was detected by the Alaska Volcano Observatory (AVO) and also initiated an increased observation frequency for ASTER. A complete framework of the eruptive cycle from April 2000 to January 2001 was established, with the Advanced Very High Resolution Radiometer (AVHRR) data used to monitor the large eruptions and produce the average yearly background state for the volcano. Twenty, nearly cloud-free ASTER scenes (2 days and 18 nights) show large thermal anomalies covering tens to hundreds of pixels and reveal both the actively erupting and restive (background) state of the volcano. ASTER short-wave infrared (SWIR) and thermal infrared (TIR) data were also used to validate the recovered kinetic temperatures from the larger AVHRR pixels, as well as map the volcanic products and monitor the thermal features on the summit dome and surrounding small pyroclastic flows. These anomalies increase to greater than 90 °C prior to a larger eruption sequence in October 2000. In addition, ASTER has the first multispectral spaceborne TIR capability, which allowed for the modeling of micrometer-scale surface roughness (vesicularity) on the active lava dome. Where coupled with ongoing operational monitoring programs like those at AVO, ASTER data become extremely useful in discrimination of small surface targets in addition to providing enhanced volcanic mapping capabilities.
An Analytical Solution to a Matrix Riemann-Hilbert Problem

The matrix Riemann-Hilbert problem relevant to the BGK model in the kinetic theory of gases is solved analytically.
Anxiety and spatial attention moderate the electrocortical response to aversive pictures

Aversive stimuli capture attention and elicit increased neural activity, as indexed by behavioral, electrocortical and hemodynamic measures; moreover, individual differences in anxiety relate to a further increased sensitivity to threatening stimuli. Evidence has been mixed, however, as to whether aversive pictures elicit increased neural response when presented in unattended spatial locations. In the current study, ERP and behavioral data were recorded from 49 participants as aversive and neutral pictures were simultaneously presented in spatially attended and unattended locations; on each trial, participants made same/different judgments about pictures presented in attended locations. Aversive images presented in unattended locations resulted in increased error rate and reaction time. The late positive potential (LPP) component of the ERP was only larger when aversive images were presented in attended locations, and this increase was positively correlated with self-reported state anxiety. Findings are discussed in regard to the sensitivity of ERP and behavioral responses to aversive distracters, and in terms of increased neural processing of threatening stimuli in anxiety.
Evaluation of a hospital medical library class for NICU nurses.

Abstract A library class was designed and offered to new nurses from the Neonatal Intensive Care Unit at the Children's Hospital of Michigan between 2003 and 2005. The class was intended to increase their knowledge of quality health information resources and to assist them with their smooth transition to a new health care organization. The goal of the library training class was to develop the nurses' awareness and knowledge of the library services and online resources on the organization Intranet and to improve their skills in finding reliable information related to patient care, patient parent education, and research. An evaluation study was conducted to assess the effectiveness of the library class. Although the findings demonstrated strengths of the library class, they also revealed some areas for improvement. The data gathered resulted in a number of recommendations regarding library instruction design and evaluation.