cssi/SciSciGPT-SciSciNet huggingface dataset:
Parallel electric fields in mixing hot and cold plasmas in the auroral downward current region: Double layers and ambipolar fields

[1] Using a 2.5-D parallel particle-in-cell simulation of a plasma of long length parallel to an ambient magnetic field Bo, we study the processes involved in determining the distribution of an applied electric potential drop parallel to Bo. The simulated plasma consists of both hot and cold plasmas of the magnetospheric and ionospheric origins, respectively. The former plasma is at a higher positive potential with respect to the latter, and thus the simulation results are relevant to the auroral downward current regions. The parallel processing enables us to simulate a long system with the magnetic field-aligned dimension Lz ∼ 8192 λdo, where λdo is the plasma Debye length. We find that when the initially empty simulation box accumulates sufficient plasma supplied from hot plasma from the top and cold plasma from the bottom, a density cavity forms at the interface between the hot and cold plasmas. A part of the applied potential drop occurs in the cavity as a double layer (DL), while the rest of it as ambipolar fields supported by the density gradient in the hot plasma density on the high-potential side (HPS) of the DL. The DL propagates upward. The HPS of the DL is rich in large-amplitude electron holes. At later times in the evolution of plasma and fields as the DL reaches the top boundary, we find that a major part of the applied potential is distributed over long distances giving only a weak ambipolar type of parallel electric fields. Then again the distributed potential evolves into localized potential drops like in a stack of multiple double layers. The double layers and associated cavities emerge from low-frequency and long-wavelength oscillations in the presence of very hot ions. Parallel currents in the plasma seem to be the only source of free energy for driving the oscillations. We report the evolution of the electron velocity distribution functions as the potential distribution evolves.
In Situ Spectroscopic Investigation of the Molecular and Electronic Structures of SiO2 Supported Surface Metal Oxides

Groups 5−7 transition metal oxides (V2O5, Nb2O5, Ta2O5, CrO3, MoO3, WO3, Re2O7) were anchored on a SiO2 support via incipient wetness impregnation and calcination. The molecular and electronic structures of the dehydrated supported metal oxides and the SiO2 support were determined by combined in situ Raman, IR, and UV−vis spectroscopy under dehydrated conditions. In situ Raman characterization reveals that the supported metal oxides are only present as surface species below the maximum dispersion limit (where crystalline metal oxide nanoparticles are absent). In situ IR analysis shows that the surface metal oxides anchor to the SiO2 support at Si−OH and adjacent Si−O−Si sites. The corresponding in situ UV−vis diffuse reflectance spectroscopy indicates that the dehydrated surface metal oxide species are present as isolated structures. Isotopic D2O−H2O exchange demonstrates that the dehydrated surface MOx species possess the MO oxo functionality but no MOH bonds. The number of MO oxo bonds was found to be r...
Fetal Heart Rate Monitoring Casebook: Checkmark Fetal Heart Rate Pattern and Normal Neonatal Outcome

BACKGROUND: A checkmark pattern of the fetal heart rate (FHR) had been seen in association with hypoxia in human and animal fetuses. CASE: We report a checkmark pattern in a fetus of a 26-year-old primigravida who underwent induction of labor at term. Scalp pH was 7.32. Comprehensive ultrasound examination revealed normal results. The neonate was born in satisfactory condition. Apgar scores were 7 and 10 at 1 at 5 minutes of life, respectively. CONCLUSION: Checkmark FHR pattern may be a benign finding; however, if it is detected, it should be closely monitored.
Using a prototype voxel for visualizing volumetric data

We present a method for visualizing volumetric data such as NMI or CAT-scan data that makes use of a data structure called the prototype voxel to create images very quickly on common workstation screens. The algorithm speeds up the standard process of casting rays through the volume data by precomputing a great deal of direction and interpolation information, assuming that all voxels are the same size and shape (which is normally the case for medical data sets). As rays are cast, this information, stored in the prototype voxel, is merely looked up when needed rather than being recomputed repeatedly. The prototype voxel must be computed only once for each data configuration; subsequent data sets which use the same size and shape of voxel can use the same prototype voxel information to speed rendering. This algorithm trades memory for speed: it uses 20 to 50 megabytes of memory (already becoming commonly available in modern workstations) for its speed improvements.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Genetic interactions involving five or more genes contribute to a complex trait in yeast.

Recent research suggests that genetic interactions involving more than two loci may influence a number of complex traits. How these ‘higher-order’ interactions arise at the genetic and molecular levels remains an open question. To provide insights into this problem, we dissected a colony morphology phenotype that segregates in a yeast cross and results from synthetic higher-order interactions. Using backcrossing and selective sequencing of progeny, we found five loci that collectively produce the trait. We fine-mapped these loci to 22 genes in total and identified a single gene at each locus that caused loss of the phenotype when deleted. Complementation tests or allele replacements provided support for functional variation in these genes, and revealed that pre-existing genetic variants and a spontaneous mutation interact to cause the trait. The causal genes have diverse functions in endocytosis (END3), oxidative stress response (TRR1), RAS-cAMP signalling (IRA2), and transcriptional regulation of multicellular growth (FLO8 and MSS11), and for the most part have not previously been shown to exhibit functional relationships. Further efforts uncovered two additional loci that together can complement the non-causal allele of END3, suggesting that multiple genotypes in the cross can specify the same phenotype. Our work sheds light on the complex genetic and molecular architecture of higher-order interactions, and raises questions about the broader contribution of such interactions to heritable trait variation.
The use of gelatin capsules for ingestion of formula in dietary treatment of maternal phenylketonuria.

Maternal phenylketonuria (PKU) represents a high risk for birth defects, including mental retardation, in offspring. Thus, it could cancel gains represented by the prevention of PKU-induced mental retardation in the current generation. Effective dietary treatment of maternal PKU pregnancies could avoid this potentially tragic occurrence. However, dietary compliance is often difficult because a necessary component of the diet, medical nutritional formulas, often have an unpleasant taste and odour. We treated the second pregnancy of a phenylketonuric women who had required extended hospitalization during her first pregnancy because of poor formula tolerance, and who had similar difficulty in the second pregnancy. To alleviate this problem, we developed a system whereby she could pack the formula into gelatin capsules for ingestion. Packing and ingestion of 20 capsules required less than 30 minutes three times a day. With capsules her blood phenylalanine level was almost always within the recommended range of 120–360 µmol/L (2–6 mg/dl) and hospitalization was not required. The phenylalanine content of the capsules was easily accommodated by a small reduction in allowable food. Other amino acid levels, including tyrosine and other essential nutrient levels, were normal. We believe that using gelatin capsules for formula ingestion can be very beneficial in the management of maternal PKU pregnancies and could be extended to the dietary treatment of other inborn errors of metabolism.
Thermodynamics and Kinetics of Hydrogen Evolution in Hydrogenated Amorphous Silicon Films

The enthalpy (endothermic) of hydrogen evolution from p-type (boron doped) amorphous silicon with 17 at. % H was 4.8, 10.3, 15.8 and 17.3 kJ/g, the evolution temperature was 585, 606, 625 and 644 °C and the entropy of evolution was 5.6, 11.7, 17.5 and 18.9 J/g.K at heating rates of 5, 10, 20 and 30 °C/min respectively. That the enthalpy and entropy increased with heating rate means that the evolution involves not only Si-H bond breaking, but also Si-Si bond breaking and other defect formation. The Si-Si bond breaking and defect formation were enhanced at high heating rates, which caused high rates of hydrogen evolution. For n-type (phosphorous-doped) and intrinsic amorphous silicon with 25 and 23 at. % H respectively, the enthalpy and entropy of hydrogen evolution were higher than the p-type case, due to severe defect formation resulting from the higher hydrogen content. The activation energy of hydrogen evolution was 1.38, 2.5 and 4 kJ/g for the p-type, intrinsic and n-type materials respectively. Crystallization which occurred at temperatures higher than hydrogen evolution, was delayed for the amorphous silicon film in a higher disordered state after hydrogen evolution, suggesting that hydrogen evolution influenced the crystallization process.
A high-throughput model for fat graft assessment.

Background and Objectives Current fat-graft animal models require weeks, to months, for results. The purpose of this study was to develop a model for the rapid identification of adipocyte protectants, using apoptosis-specific fluorescence. The goal of our model was to predict long-term fat graft survival within a 10-day period. Study Design/Materials and Methods Human fat was obtained from liposuction aspirates, washed with saline, and centrifuged at 200g. The fat was then treated with one of four agents: P188, polyethylene glycol (PEG 8000), lipoic acid (LA), or saline control. Fat lobules were explanted over a 10-day period, and then at six weeks. The explanted fat was measured for apoptosis. Samples were weighed, sent for histology, measured for DNA content, and examined using confocal microscopy. Results Fat-grafts demonstrated variable apoptosis over the 10-day period. P188 and LA treated samples demonstrated 11–28% less apoptosis during early engraftment than saline treated controls. This early reduction in apoptosis correlated to a ∼20% reduction in reabsorption by weight six weeks later. P188 and LA samples demonstrated three-times higher DNA content by PICO green analysis when compared to saline controls. PEG 8000 treated samples demonstrated 11% more apoptosis than saline. PEG 8000 treated samples demonstrated an approximately 10% higher level of reabsorption by weight, and two-times higher levels of DNA. Histology of treated samples at six weeks showed architecturally normal fat in P188 and LA treated fat; whereas PEG 8000 had high levels of inflammatory infiltrates, and saline had large amounts of fibrosis. Conclusions This model of fat-grafting and early apoptosis can be used to screen agents and grafting methods and predict long-term graft survival. We show that levels of apoptosis within ten days correlate with weight, DNA, and histology, at six weeks. Using this model, long-term adipocyte survival and graft take can be predicted during the first 10 days post-implantation. Lasers Surg. Med. 41:738–744, 2009. © 2009 Wiley-Liss, Inc.
Herpes Simplex Skin Infection in Mice.

Although the effects of herpes simplex virus have been extensively studied in many laboratory animals, only a few reports have appeared in the literature concerning the local skin response in these animals following injection with herpes simplex virus. The formation of a local lesion in the skin of mice, guinea pigs, and rabbits has been described previously. Following inoculation of herpes simplex virus into the scarified
Diverging Racial Trends in Neonatal Infantile Hemangioma Diagnoses, 1979–2006

Nationally representative historical trends in neonatal infantile hemangioma (IH) diagnosis have not been previously assessed. Using the National Hospital Discharge Survey (NHDS), trends in IH diagnoses were assessed according to race and sex. Findings confirmed prior research that female and white newborns are more likely to be diagnosed with IH, and a statistically significant increase in IH diagnoses was observed in white, but not in nonwhite, infants.
DNA microarray analysis of the expression profiles of luteinized granulosa cells as a function of ovarian reserve.

Abstract Objective: To examine the expression profiles of luteinized granulosa cells isolated from women with normal or diminished ovarian reserve undergoing in vitro fertilization. Design: Expression profiling by complementary DNA microarray analysis. Setting: Women undergoing in vitro fertilization-embryo transfer in a university-based fertility clinic. Patient(s): Eighteen women with normal or decreased ovarian reserve. Intervention(s): All patients were given gonadotropin stimulation in preparation for IVF with granulosa cells isolated at the time of follicular aspiration. Main Outcome Measure(s): Expression profiles of luteinized granulosa cells isolated from each woman were determined by using DNA microarray analysis. Result(s): Changes in patterns of gene expression in granulosa cells were observed between women with normal and diminished ovarian reserve. These genes included several anonymous expressed sequence tags and also expressed sequence tags that correspond to known genes. Conclusion(s): Expression profiling of granulosa cells by DNA microarray may yield signature patterns that reflect the status of ovarian reserve and the competence of granulosa cells.
A century of enzyme kinetic analysis, 1913 to 2013

This review traces the history and logical progression of methods for quantitative analysis of enzyme kinetics from the 1913 Michaelis and Menten paper to the application of modern computational methods today. Following a brief review of methods for fitting steady state kinetic data, modern methods are highlighted for fitting full progress curve kinetics based upon numerical integration of rate equations, including a re-analysis of the original Michaelis-Menten full time course kinetic data. Finally, several illustrations of modern transient state kinetic methods of analysis are shown which enable the elucidation of reactions occurring at the active sites of enzymes in order to relate structure and function.
Estimation of Manning's roughness coefficient distribution for hydrodynamic model using remotely sensed land cover features

This research explores the potential of remote sensing techniques to derive distributed Manning's roughness coefficient (Manning's n) for the use in hydrodynamic models for numerical simulation of open channel flow in natural channels and flood plains. Normalized Difference Vegetation Index (NDVI) based land use land cover (LU/LC) data was generated using the Landsat 5 Thematic Mapper (TM) and Advance Land Observing Satellite (ALOS) Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) imagery. Manning's n were obtained from published literature for different features in flood plains and correlated with the remote sensing derived LU/LC features. CCHE2D model, developed by the National Center for Computational Hydroscience and Engineering (NCCHE), at The University of Mississippi, for simulating two dimensional depth-averaged unsteady flow and sediment transport was used to validate the remote sensing derived distributed Manning's n for channel flow calculation. Results obtained from this research indicate that satellite imagery derived LU/LC data has potential to be used to improve hydrodynamic model simulation by providing distributed Manning's roughness coefficient for respective model domains.
Absorption of Ultrasonic Waves by Various Gases

Absorption coefficient for ultrasonic waves in C${\mathrm{O}}_{2}$, ${\mathrm{N}}_{2}$, ${\mathrm{H}}_{2}$ and He.---A beam of ultrasonic waves with a frequency of 612 kilocycles from an oscillating quartz crystal was passed through a mixture of gas and air, contained in a brass absorption tube with ends covered by thin celluloid films. The design of the tube greatly reduced the effect of resonance and allowed the use of two different lengths of absorbing gas, leaving the geometrical arrangement of openings and absorbing screens the same. The emergent beam was allowed to fall upon another quartz crystal which had a natural frequency very nearly equal to the frequency of the waves and which was connected to the grid of a triode. The intensity of the received signal was measured by a previously calibrated vacuum tube voltmeter. A logarithmic decrease in the transmitted energy with increase in the percentage of the gas in the mixture was found with C${\mathrm{O}}_{2}$, ${\mathrm{N}}_{2}$O, ${\mathrm{H}}_{2}$, and He. The increase in the absorption coefficient (${\mathrm{cm}}^{\ensuremath{-}1}$) at 612 kilocycles when air was replaced by a mixture containing 1 percent by volume of the gas was found for C${\mathrm{O}}_{2}$ to be 0.029; for ${\mathrm{N}}_{2}$O, 0.034, for ${\mathrm{H}}_{2}$, 0.014, for He, 0.0025. For argon mixtures no absorption was observed.Reflection of ultrasonic wave by a thin celluloid film. The fractional part of the beam which was transmitted by the films at the ends of the absorption tube, increased with increase in percentage of C${\mathrm{O}}_{2}$ and ${\mathrm{N}}_{2}$O but decreased with increase in percentage of ${\mathrm{H}}_{2}$ and He, agreeing qualitatively with Rayleigh's theory.
Electron-Beam-Based Sources of Ultrashort X-ray Pulses

A review of various methods for generation of ultrashort X-ray pulses using relativistic electron beam from conventional accelerators is presented. Both spontaneous and coherent emission of electrons are considered.
Stress compounds in tobacco callus infiltrated by Pseudomonas solanacearum

Abstract Two sesquiterpenoids, phytuberin and phytuberol, have been identified in tobacco callus infiltrated by Pseudomonas solanacearum .
Impact of axillary lymph node dissection on breast cancer outcome in clinically node negative patients: a systematic review and meta-analysis.

BACKGROUND: The regional lymph node control and survival impact of axillary dissection in breast cancer has been the subject of multiple randomized trials, with various results. This study reviews and conducts a meta-analysis of contemporary trials of axillary dissection in patients with early stage breast cancer. METHODS: A systematic MEDLINE review identified 3 randomized trials published between January 2000 and January 2007 of axillary dissection versus no dissection in clinically lymph node negative early stage breast cancer patients. A fourth trial of axillary radiotherapy versus no axillary treatment was also identified and included in this review. Meta-analyses were performed for survival, axillary recurrence, metastatic disease, and ipsilateral breast recurrence. RESULTS: All trials reported a higher rate of axillary recurrence (1.5%-3%, median follow-up 5-15 years) in the absence of axillary dissection or radiotherapy. Overall survival was similar with and without definitive axillary treatment in 3 of the 4 trials, with an increased rate of nonbreast cancer-related death in the observation arm of the fourth trial. Meta-analyses found no significant difference in overall survival (odds ratio [OR] 1.55; 95% confidence interval [CI], 0.74-3.24), metastases (OR 0.91; 95% CI, 0.65-1.29), or ipsilateral breast recurrence (OR 1.11; 95% CI, 0.68-1.83) associated with axillary treatment. A significantly lower rate of axillary recurrence was seen after lymphadenectomy (OR 0.28; 95% CI, 0.11-0.73, P<.01). CONCLUSIONS: Axillary dissection does not confer a survival benefit in the setting of early stage clinically lymph node negative breast cancer. Although the rate of axillary failure was increased in the absence of dissection, the absolute risk was found to be extremely low. Cancer 2009. © 2009 American Cancer Society.
On generalized plus-constructions of Eilenberg–Mac Lane spaces

Abstract A GEM is an infinite loop space which is weakly equivalent to a product of Eilenberg–Mac Lane spaces. In this paper, the fiber of any f-localization map of a GEM is shown to be a GEM again. Using this result, we compute explicitly the p-local and p-torsion generalized plus-constructions of abelian Eilenberg–Mac Lane spaces. We also prove some arithmetic square results to compute the generalized plus-construction of Eilenberg–Mac Lane spaces in general.
Short Duration Needle Trap Sampling with Gas Chromatography Analysis to Determine Nearly Instantaneous Concentrations of Selected Organic Vapor Contaminants

Needle trap device samplers were used for rapid (60 s) quantitative sampling of short-term exposure limit (STEL) and peak exposure standard concentrations using a manually operated pump to collect small volume (10 mL) gas phase samples containing methylene chloride, benzene, toluene, and tetrachloroethylene vapors. Solventless introduction of chemical samples for gas chromatography analysis with flame ionization detection yielded linear results (R2 > 0.99) for vapor standard mixtures of the four target analytes ranging from 10% to 200% of their respective nominal STEL or peak exposure standard concentrations. Needle trap samplers showed ≥86% recovery (as GC-FID peak area responses) following 14-day storage at room temperature compared to the same samplers analyzed immediately, with better recovery values observed with shorter storage (≥95% at room temperature for seven days, except for methylene chloride) or with storage at 4°C. Calibration for quantitation of concentrations of benzene, toluene, and tetra...
An Enactive Characterization of Pretend Play

This paper presents the result of an empirical study of 32 adult dyads (i.e. groups of two people) engaged in pretend play. Our analysis indicates that participatory sense-making plays a key role in the success of pretend play sessions. We use the cognitive science theory of enaction as a theoretical lens to analyze the empirical data given its robust conceptual framework for describing participatory sense-making. We present here five enactive characteristics of pretend play that appear to be necessary and sufficient for the emergence and maintenance of successful pretend play -- mental preparation, meaning building, narrative enaction, narrative deepening, and flow maintenance. This enactive formalization is used to propose a computational model of pretend play that can be used to design an agent capable of playing in real time with human users.
HSV-1 thymidine kinase negative vaccine: pathogenicity, protection, and perils.

Primary inoculation of mice and rabbits with an avirulent HSV-1 thymidine kinase negative (TK −) mutant reduced keratitis, mortality, and superinfection of the trigeminal ganglion (TG) as measured by cocultivation and iontophoresis-induced ocular shedding following ocular challenge with HSV-1 McKrae and W strains. However species differences were demonstrated; with complete protection in rabbits, and incomplete protection in mice. In mice, BUDR/autoradiography and restriction enzyme analysis identified both HSV-1 McKrae and W strains as having super infected the TG, established latency and reactivated. Also, the avirulent TK negative inoculating strain was altered to a virulent TK positive strain through possible in vivo selection, mutation &/or host-modification, and possible in vivo recombination with the virulent challenge strains. We conclude that lower species differences require that potential HSV-1 vaccines be tested in non-human primates prior to clinical trials, and that a DNA-free subunit herpes...
Can Dataflow Subsume Von Neumann Computing

We explore the question: “What can a von Neumann processor borrow from dataflow to make it more suitable for a multiprocessor?” Starting with a simple, “RISC-like” instruction set, we show how to change the underlying processor organization to make it multithreaded. Then, we extend it with three instructions that give it a fine-grained, dataflow capability. We call the result P-RISC, for “Parallel RISC.” Finally, we discuss memory support for such multiprocessors. We compare our approach to existing MIMD machines and to other dataflow machines.
Drawing a Better Line: UTI Possidetis and the Borders of New States

It is now conventional wisdom that the proliferation of ethnic-based violence constitutes the greatest threat to public order and human rights since the lifting of the Iron Curtain. The eruption of hatreds, whether suppressed or ignored for a half century or newly arisen, has unleashed centrifugal forces that are pulling states apart from Africa to Europe to South and Central Asia. To date, the response of the effective decision makers in the international community has been ambiguous and inconstant: the United Nations member states reiterate the importance of the unity of all states, but they accept accomplished breakups after the fact, all the while insisting on the protection of minorities within states. Political philosophers struggle with the circumstances under which secession and dissolution are desirable; international law declares the lack of either a blanket right to, or prohibition against, secession and seemingly relegates its achievement to a pure power calculus.
Social injustice, human rights-based education and citizens’ direct action to promote social transformation in the Philippines:

This article opens with a proposed framework for human rights education (HRE), which synthesizes ideas drawn from Zinn’s people’s history, Sen’s theory of justice and Freire’s critical pedagogy. A ...
Effects of university affiliation and "school spirit" on color preferences: Berkeley versus Stanford.

The ecological valence theory (EVT) posits that preference for a color is determined by people’s average affective response to everything associated with it (Palmer & Schloss, Proceedings of the National Academy of Sciences, 107, 8877–8882, 2010). The EVT thus implies the existence of sociocultural effects: Color preference should increase with positive feelings (or decrease with negative feelings) toward an institution strongly associated with a color. We tested this prediction by measuring undergraduates’ color preferences at two rival universities, Berkeley and Stanford, to determine whether students liked their university’s colors better than their rivals did. Students not only preferred their own colors more than their rivals did, but the degree of their preference increased with self-rated positive affect (“school spirit”) for their university. These results support the EVT’s claim that color preference is caused by learned affective responses to associated objects and institutions, because it is unlikely that students choose their university or develop their degree of school spirit on the basis of preexisting color preferences.
Feasibility of clofarabine cytoreduction before allogeneic transplant conditioning for refractory AML

To control disease before allogeneic hematopoietic cell transplantation (HCT) for relapsed/refractory AML, we used clofarabine cytoreduction. Seventeen patients received clofarabine 30–40 mg/m2 i.v. daily for 5 days with plans to initiate conditioning during the nadir, 14 days later. Bone marrow biopsy 12 days after clofarabine showed effective cytoreduction (that is,<20% cellularity with <10% blasts) in 10 of 17 patients (59%). Ineffective cytoreduction correlated with lower PFS (3.8 vs 6.4 months; HR=2.7, 95% CI=1.10–14.29, P=0.035) and OS (5.1 vs 16.6 months; HR=2.5, 95% CI=0.98–12.17, P=0.053). Significant toxicities before HCT, attributable to clofarabine, were grade 1–2 hyperbilirubinemia (18%); grade 1–2 (59%) or grade 3–4 (18%) transaminitis; and grade 1–2 (18%) creatinine elevation. Sixteen patients proceeded to HCT infusion 22 days (median) after initiation of clofarabine. Day 100 and 2-year transplant-related mortality were 6 and 36%. Nine patients relapsed. One year PFS and OS were 25 and 38%, respectively. Two patients are alive in remission at 18 and 52 months. Clofarabine cytoreduction followed by immediate HCT is feasible with acceptable toxicity and TRM. Outcomes for this cohort of patients with refractory AML remain poor and we are studying this approach in a prospective manner.
Analytical model for sub-diffusive light reflection and the application to spatial frequency-domain imaging

We present here an analytical model describing light reflectance at an arbitrary source-detector separation covering both sub-diffusive and diffusion regimes for forward-peaked scattering media such as biological tissue. The model incorporates the small-angle scattering approximation (SAA) to radiative transfer for sub-diffusive light reflectance at a source-detector separation less than one single scattering length where the details of the phase function of light scattering dominate. The performance of the model is verified by Monte Carlo simulations. We also present the application of this analytical model in spatial frequency-domain imaging, in particular, when the spatial frequency is pushed below the reduced scattering coefficient.
False feedback inhibition of aromatic amino acid biosynthesis by β-2-thienylalanine

Abstract 1. 1. In Escherichia coli , β-2-thienylalanine drastically inhibited protein synthesis within 5 min. Shikimic acid reversed the inhibition non-competitively. The non-competitive nature of the inhibition was confirmed both by measuring the internal concentration of thienylalanine and by estimating it from the rate of thienylalanine incorporation into protein. 2. 2. The 3-deoxy- d - arabino -heptulusonic acid 7-phosphate (DAHP) synthetase normally inhibited by phenylalanine is the principal one present in exponentially growing cells in minimal medium. It was strongly inhibited by thienylalanine. There was no inhibition of the tyrosine-controlled DAHP synthetase. 3. 3. A mutant selected for resistance to thienylalanine had a normal amount of DAHP synthetase. About half of the enzyme was the tyrosine-repressible species, and the other half was insensitive to inhibition by phenylalanine or tyrosine, or repression by tyrosine or tryptophan. 4. 4. The K m for phenylalanine with phenylalanyl-RNA synthetase was 6·10 −6 M. The K i for thienylalanine inhibition of phenylalanine activation was approx. 2·10 −4 M. Although thienylalanine was incorporated into protein, transfer of thienylalanine to transfer RNA by the phenylalanyl-RNA synthetase could not be demonstrated in vitro . 5. 5. The data indicate that false feedback inhibition of the phenylalanine-sensitive DAHP synthetase was responsible for the immediate inhibition of protein synthesis by thienylalanine.
Surface Enrichment in a Miscible Polymer Blend: An Experimental Test of Self-Consistent Field and Long-Wavelength Approximation Models

Neutron reflectivity (NR) and low-energy forward recoil spectrometry (LE-FRES) were used to study surface enrichment in miscible blends of deuterated polystyrene, d-PS, and poly(styrene-co-4-bromostyrene), PBr0.049S, having a 0.049 mole fraction of 4-bromostyrene units. The d-PS component was found to segregate preferentially to the polymer blend/air interface, whereas no enrichment of either component was detected at the polymer blend/silicon interface. The experimental values of the surface concentration, φ1, and the surface excess, z*, of d-PS were interpreted using both the theory of Schmidt and Binder (SB) (J. Phys. II (Paris) 1985, 46, 1631) and the self-consistent field (SCF) approach of Genzer et al. (Phys. Rev. E 1994, 50, 2373). Although both SB and SCF models were found to be in good qualitative agreement with the experimentally measured values of φ1 and z*, we demonstrate that the latter proves to be in better quantitative agreement with the experimental results. Moreover, a comparison of the ...
Optoelectronic neural dendritic tree processing with electron-trapping materials

We show that under simultaneous illumination of pulsed blue light and constant IR light the dynamic responses of electron-trapping materials could be employed to implement optically controlled neural dendritic responses. The importance of neurocomputing with biology-oriented spiking neurons and the role played by dendritic trees are discussed. Computer simulations of dendritic responses in biological neuron and experimental results of electron-trapping material dynamics are presented. These results show that electron-trapping materials are well suited for implementing optically controlled dendritic responses for use in large-scale biology-oriented optoelectronic spiking neural networks.
Testing of cold scaled bed modeling for fluidized-bed combustors

Abstract The purpose of this study was to determine whether cold scaled models with scaled particles give the correct hydrodynamic predictions for the gas and solids in an actual hot atmospheric pressure fluidized-bed combustor. Continuity equations and momentum balance equations of the gas and solid particles in fluidized beds were used in developing four dimensionless scaling groups which were utilized in sizing four different fluidized beds. Pressure fluctuations data collected from the different beds we are compared. Auto-correlation plots of the pressure fluctuations from one bed when compared with its scaled counterpart were observed to be of the proper scaled frequency. The fluctuations were of the same magnitude when scaled but the magnitudes were not statistically significant.
Hepatoblastoma in an equine fetus.

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Oncogenic H-Ras increases glucose metabolism with an induction of glucose transporter GLUT1 and hexokinase 2 expression

INTRODUCTION: Oncogenic Ras supports the development of cancer cells by activating pathways that stimulate growth and prevent apoptosis. Increased glucose metabolism is a hallmark of cellular transformation. The profiles of glucose transporter (GLUT) and/or hexokinase (HK) family members may be altered to more efficiently utilize glucose after mutant Ras transformation. HK1 and 2 mitochondrial localization have been associated with alterations in apoptosis sensitivities.
Human Neutrophil Elastase Induces Hypersecretion of Mucin from Well-Differentiated Human Bronchial Epithelial Cells in Vitro via a Protein Kinase Cδ-Mediated Mechanism

The presence of mucus obstruction and neutrophil-predominant inflammation in several lung disorders, such as cystic fibrosis, suggests a relationship between neutrophils and excess mucus production. Mechanisms of human neutrophil elastase (HNE)-induced mucin secretion by well-differentiated normal human bronchial epithelial (NHBE) cells maintained in air/liquid interface culture were investigated. HNE increased mucin secretion in a concentration-dependent manner, with maximal stimulation (more than twofold) occurring within a short (15 minutes) time period. Mucins MUC5AC and MUC5B, but not MUC2, were released in response to HNE. Stimulation of mucin secretion required partial elastase enzymatic activity and did not appear to involve a soluble product released by the cells. HNE-stimulated secretion involved activation of protein kinase C (PKC), as HNE exposure rapidly provoked PKC enzymatic activity that was attenuated by the general PKC inhibitors calphostin C and bisindoylmaleimide I. Of the different isoforms, PKCα, δ, ζ, λ, ι, and e were constitutively expressed in NHBE cells while PKCβ, η, and μ were PMA-inducible. PKCδ was the only isoform to translocate from cytoplasm to membrane in response to HNE. Inhibition of PKCδ attenuated HNE-mediated mucin secretion. The results suggest HNE stimulation of mucin release by human airway epithelial cells involves intracellular activation of PKC, specifically the δ isoform.
Informational limits of neural circuits

With the growing amount of connectome data being gathered, it behooves us to develop systems-theoretic methods to analyze this data so as to provide insights into the function of neuronal circuits. Here, we develop models and compute capacities for gap junction synapses. We develop information-theoretic lower bounds on computation speed arising from limitations of anatomical connectivity and physical noise. For the nematode Caenorhabditis elegans, these bounds are predictive of biological timescales. Moreover, the hub-and-spoke architecture of C. elegans functional subcircuits are optimal under constraint on number of synapses.
Using simulation modeling to evaluate sentencing reform in California: choosing the future

Criminal sentencing reforms that have as their ostensible goal the protection of the public through the mechanism of selective incapacitation have proliferated in recent years. The most prominent of these types of reforms are the “Three Strikes” laws. Because these changes to sentencing policy work by extending the term of incarceration for affected offenders, rather than by changing the rate of incarceration, many years must pass before the effects of these kinds of changes can be measured and evaluated by conventional statistical methods. Data-validated dynamic systems simulation modeling offers the analyst an opportunity to evaluate prospectively the effects of such changes on prison populations. In addition to providing descriptive and evaluative information about the likely consequences of these reforms to the compositional dynamics of prison populations, dynamic systems simulation modeling also affords the analyst the opportunity to experiment upon the system to examine prospectively the likely effects of policy changes. In this paper, simulation models of the California criminal justice system are created and validated with historical data in order to provide a plausible baseline upon which to base future projections. Different policy scenarios are simulated to the year 2030 to assess experimentally the likely consequences to prison populations and to evaluate how well these policies target the “dangerous offenders” proponents that these policies promise to remove from society via incarceration.
HYLIFE-II: A Molten-Salt Inertial Fusion Energy Power Plant Design — Final Report

Enhanced safety and performance improvements have been made to the liquid-wall HYLIFE reactor, yielding the current HYLIFE-II conceptual design. Liquid lithium has been replaced with a neutronically thick array of flowing molten-salt jets (Li[sub 2]BeF[sub 4] or Flibe), which will not burn, has a low tritium solubility and inventory, and protects the chamber walls, giving a robust design with a 30-yr lifetime. The tritium inventory is 0.5 g in the molten salt and 140 g in the metal of the tube walls, where it is less easily released. The 5-MJ driver is a recirculating induction accelerator estimated to cost $570 million (direct costs). Heavy-ion targets yield 350 MJ, six times per second, to produce 940 MW of electrical power for a cost of 6.5 cents/kW[center dot]h. Both larger and smaller yields are possible with correspondingly lower and higher pulse rates. When scaled up to 1934 MW (electric), the plant design has a calculated cost of electricity of 4.5 cents/kW[center dot]h. The design did not take into account potential improved plant availability and lower operations and maintenance costs compared with conventional power plant experience, resulting from the liquid wall protection. Such improvements would directly lower the electricity cost figures. For example,more » if the availability can be raised from the conservatively assumed 75% to 85% and the annual cost of component replacement, operations, and maintenance can be reduced from 6% to 3% of direct cost, the cost of electricity would drop to 5.0 and 3.9 cents/kW[center dot]h for 1- and 2-GW (electric) cases. 50 refs., 15 figs., 3 tabs.« less
The effects of irradiation on alaryngeal voice of totally laryngectomized patients

The effects of radiation therapy on the ability of totally laryngectomized patients to produce voice and speech were examined using objective non-invasive methods. Moderate to severe losses were noted in patients producing voice with all types of alaryngeal modalities: tracheoesophageal, esophageal, and electrolaryngeal. Voice and speech losses were related to the impaired motility and vibratory capability of the esophageal wall and mucosa, to fibrosis of the submandibular region and to trismus. Tracheoesophageal and esophageal voice was recovered some weeks after completion of irradiation. No voice losses were observed in alaryngeal speakers who did not undergo voice restoration until after irradiation. All irradiated patients also showed various degrees of dysphagia during the treatment.
A Bayesian approach to modeling lost person behaviors based on terrain features in Wilderness Search and Rescue

In Wilderness Search and Rescue (WiSAR), the incident commander (IC) creates a probability distribution map of the likely location of the missing person. This map is important because it guides the IC in allocating search resources and coordinating efforts, but it often depends almost exclusively on the missing person profile, prior experience, and subjective judgment. We propose a Bayesian model that uses publicly available terrain features data to help model lost-person behaviors. This approach enables domain experts to encode uncertainty in their prior estimations and also makes it possible to incorporate human behavior data collected in the form of posterior distributions, which are used to build a first-order Markov transition matrix for generating a temporal, posterior predictive probability distribution map. The map can work as a base to be augmented by search and rescue workers to incorporate additional information. Using a Bayesian ? 2 test for goodness-of-fit, we show that the model fits a synthetic dataset well. This model also serves as a foundation for a larger framework that allows for easy expansion to incorporate additional factors such as season and weather conditions that affect the lost-person's behaviors.
Making Everyday Life Easier Using Dense Sensor Networks

Advances in hardware are enabling the creation of small, inexpensive devices and sensors. Hundreds or thousands of these devices can be connected using low-power multi-hop wireless networks. These networks foster a new class of ubiquitous computing applications called proactive computing. In proactive applications, computing occurs in the background without requiring human interaction; humans participate to access information or to modify control policies. This paper provides an overview of the application of a large wireless network of sensors to solve everyday problems in the workplace. It describes the implementation of one application that allows people in the workplace to easily find empty conference rooms (e.g., for impromptu meetings). Drawing on this experience, we identify technical challenges and possible directions for building dense networks of sensors that enable proactive computing.
Reactions of boron carbide and other boron compounds with carbon dioxide

In the reaction of boron-containing materials with carbon dioxide, most of them oxidise quite rapidly to form boron oxide, which itself reacts to give a volatile boron compound. The major part of the work concerns boron carbide, and the effects of temperature, pressure and additions of water vapour and carbon monoxide have been considered. Other materials investigated are ZrB2, TiB2, CrB2, BN, BSi9 and elemental boron.
Analytic expression for the electric potential in the plasma sheath

An expression for the spatial dependence of the electric potential in a collisionless and source-free planar plasma sheath is presented. This expression is derived by analogy with Child's law and approaches Child's law asymptotically as the potential drop phi /sub W/ across the sheath becomes large, mod e phi /sub W//kT/sub e/ mod >10/sup 4/. Here k is Boltzmann's constant, T/sub e/ is the electron temperature, and e is the electronic charge. Comparison with numerical solutions of the model equations indicates that the sheath thickness and potential variation predicted by this improved Child's law are accurate for mod e phi /sub W//kT/sub e/ mod >10. In contrast, the authors find that Child's law is accurate only when mod e phi /sub W//kT/sub e/ mod >10/sup 4/. >
Functional domains of the yeast regulatory protein GAL4

In the yeast Saccharomyces cerevisiae regulation of the galactose/melibiose regulon rests on a dosage-dependent functional interplay between the positive regulator of transcription, the GAL4 protein, and the negative regulator, GAL80 protein. We have used this interplay to select in vitro generated fusions between the yeast ADH1 promoter and GAL4 coding sequence that overproduce GAL4 protein, allowing the identification of GAL4 protein in crude extracts from yeast. One type of these constructions produces a GAL4 protein that lacks its normal NH2 terminus. This protein is unable to complement a gal4 lesion but still retains a domain that functionally antagonizes the negative regulatory protein. One defect in this truncated protein is its inability to be concentrated in the nucleus. However, the nuclear localization defect is complemented by full-length GAL4 protein. The truncated protein also appears to effect changes in the relative transcriptional levels of the structural genes. These observations imply that GAL4 protein consists of several domains, including ones for nuclear localization, interaction with the negative regulatory protein, and, possibly, separable transcriptional activation domains for the structural genes.
Processing Spatial-Keyword (SK) Queries in Geographic Information Retrieval (GIR) Systems

Location-based information contained in publicly available GIS databases is invaluable for many applications such as disaster response, national infrastructure protection, crime analysis, and numerous others. The information entities of such databases have both spatial and textual descriptions. Likewise, queries issued to the databases also contain spatial and textual components, for example, "Find shelters with emergency medical facilities in Orange County," or "Find earthquake-prone zones in Southern California." We refer to such queries as spatial-keyword queries or SK queries for short. In recent times, a lot of interest has been generated in efficient processing of SK queries for a variety of applications from Web-search to GIS decision support systems. We refer to systems built for enabling such applications as Geographic Information Retrieval (GIR) Systems. An example GIR system that we address in this paper is a search engine built on top of hundreds of thousands of publicly available GIS databases. Building a search engine over such large repositories is a challenge. One of the key aspects of such a search engine is the performance. In this paper, we propose a framework for GIR systems and focus on indexing strategies that can process SK queries efficiently. We show through experiments that our indexing strategies lead to significant improvement in efficiency of answering SK queries over existing techniques.