cssi/SciSciGPT-SciSciNet huggingface dataset:
Using the unconventional stellar aspect (USA) experiment on ARGOS to determine atmospheric parameters by x-ray occultation

The Unconventional Stellar Aspect (USA) experiment is a multi-purpose experiment built around an X-ray sensor viewing celestial sources. The objectives include both basic research in X-ray astronomy and exploration of applied uses of X-ray sensors in space. The applied uses depend in large part upon exploiting understanding of celestial X-ray point sources. The experiment was launched on February 23, 1999 from Vandenberg AFB, CA aboard the Advanced Research and Global Observation Satellite (ARGOS). USA operated from April 1999 to November 2000. It consists of two proportional counters mounted in a two-axis gimbal for offset pointing from the nadir-pointed ARGOS. We present an overview of the experiment and then describe how it is used to provide a new atmospheric diagnostic that takes the form of redundant sets of atmospheric column density determinations. The data analyzed are energy-resolved photon extinction curves of X-ray celestial sources occulted by the Earth's atmosphere. As each X-ray source is occulted by the mesosphere and lower thermosphere (80-160 km), the density profile is derived from the extinction curve and temperature is derived from the scale height; limited composition information may be derived from the energy- dependence of extinction. These data are compared to standard atmospheric models. This research is the first to study the neutral atmosphere using X-ray source occultations, and complements UV airglow remote sensing techniques used aboard ARGOS that are insensitive to nighttime neutral density.
Comparison of two-dimensional and three-dimensional models for profile simulation of poly-Si etching of finite length trenches

The development of two-dimensional (2D) profile simulators for fabrication of microelectronics features has significantly progressed during the past few years and now enables modeling of etch profile evolution for many different plasma processing conditions. Increasingly complex devices which have three-dimensional (3D) (that is, asymmetric) structures are now being designed. These structures require improved dimensionality in profile simulators to capture their most important features. Under many conditions, such as circular via etching, two-dimensional profile simulators can be used to address 3D structures. A legitimate issue is to what degree these 2D approaches can indeed be applied to truly 3D structures. In this article, we present results from a 3D profile simulator for the purpose of comparing profiles for innately 3D features to results obtained from a 2D profile simulation. It has been found that profiles obtained from the 3D simulators exhibit greater sidewall sloping in three-plane corners than predicted by the 2D simulator. The implication to process design is that a greater degree of overetching will be required to clear these corners than predicted by the 2D simulators. Asymmetries as well as the angular spread of the ion flux distribution are examined to determine their role in 3D profile evolution.
Stability of reconstituted parecoxib for injection with commonly used diluents

Summary Objective: The purpose of this study was to evaluate the effect of diluent type, storage conditions and the nature of package on the stability of reconstituted Parecoxib sodium for injection (PSI). Methods: Parecoxib sodium for injection is a lyophilized product for single use. It is intended for the management of acute pain. Six diluent types were initially evaluated for physical compatibility with PSI. Reconstituted PSI was visually inspected at 8, 24 and 48 h after reconstitution with 0·9% sodium chloride injection (NS), lactated ringers injection (LR), bacteriostatic 0·9% NaCl injection (BNS), lactated ringers and 5% dextrose injection (LR + D5W), 5% dextrose injection (D5W), and 5% dextrose + 0·45% NaCl injection (D5W + 1/2NS). Reconstituted PSI, stored in glass vials and glass or plastic syringes at 5° and 25°C, under 500 lx light intensity for 48 h or subjected to freeze-thaw cycles, were tested for chemical stability by high-performance liquid chromatography (HPLC). Results: The PSI reconstituted with NS, BNS, D5W, and D5W + 1/2NS met visual acceptance criteria and showed almost no (<0·5% total) degradation under all storage conditions. No significant differences were seen between storage in glass vials or polypropylene/glass syringes. PSI reconstituted with LR and LR + D5W showed visual precipitation in many vials which was confirmed by the decrease in the HPLC assay values at all time points. The needlelike crystals (precipitate), analyzed by Infrared Spectroscopy and Scanning Electron Microscopy–Energy Dispersive Spectrometry (SEM–EDS) analyses, were identified as the free acid form of the active drug. Conclusion: PSI is stable after reconstitution, with NS, BNS, D5W, and D5W + 1/2NS, when stored at room temperature in glass vials or glass/plastic syringes for up to 48 h* LR and LR + D5W are not recommended for reconstitution because of crystallization of the drug (free acid).
Apples and oranges: mixed lineage acute leukemia.

In this issue of Blood , Rubnitz and colleagues from St Jude Children's Research Hospital provide important information concerning the immunophenotypic, cytogenetic, gene expression, and response to therapy characteristics of 35 patients with so-called mixed lineage leukemia. Identification of
The X-ray Structure of the Type II Secretion System Complex Formed by the N-terminal Domain of EpsE and the Cytoplasmic Domain of EpsL of Vibrio cholerae.

Gram-negative bacteria use type II secretion systems for the transport of virulence factors and hydrolytic enzymes through the outer membrane. These sophisticated multi-protein complexes reach from the pore in the outer membrane via the pseudopilins in the periplasm and a multi-protein inner-membrane sub-complex, to an ATPase in the cytoplasm. The human pathogen Vibrio cholerae uses such a secretion machinery, called the Eps-system, for the export of its major virulence factor cholera toxin into the intestinal tract of the human host. Here, we describe the 2.4 A structure of the hetero-tetrameric complex of the N-terminal domain of the ATPase EpsE and the cytoplasmic domain of the inner membrane protein EpsL, which constitute the major cytoplasmic components of the Eps-system. A stable fragment of EpsE in complex with the cytoplasmic domain of EpsL was identified via limited proteolysis and facilitated the crystallization of the complex. This first structure of a complex between two different proteins of the type II secretion system reveals that the N-terminal domain of EpsE and the cytoplasmic domain of EpsL form a hetero-tetramer, in which EpsL is the central dimer and EpsE binds on the periphery. The dimer of EpsL in this complex is very similar to the dimer seen in the crystal structure of the native cytoplasmic domain of EpsL, suggesting a possible physiological relevance despite a relatively small 675 A2 buried solvent accessible surface. The N-terminal domain of EpsE, which forms a compact domain with an alpha+beta-fold, places its helix alpha2 in a mostly hydrophobic cleft between domains II and III of EpsL burying 1700 A2 solvent accessible surface. This extensive interface involves several residues whose hydrophobic or charged nature is well conserved and is therefore likely to be of general importance in type II secretion systems.
Context, tissue plasticity, and cancer: Are tumor stem cells also regulated by the microenvironment?

Lest we forget, within every higher organism, there are literally billions of cells with identical genetic information that serve as constituents of the different tissues and organs. Given that genetic information is the same in all cells, including the stem cells, by definition, cells in higher organisms do not possess a sense of place or purpose by themselves. Therefore, in order for each organ to operate successfully within the context of the organism, all cells must be integrated into an architectural and signaling framework such that each cell knows exactly which commands to execute at any given time. Success at this daunting task leads to homeostasis, while failure results in a spectrum of dysfunctions, including cancer. How do organisms achieve this remarkable feat, and how does each cell in return know what to do within the tissues?
Long-term follow-up of patients operated on for recurrent carotid stenosis

Abstract We reviewed our experience with 29 operations for recurrent carotid stenosis in 27 patients who underwent both their primary carotid endarterectomy and their reoperations at our institution. These 27 patients represent 4% of the 667 patients who underwent primary carotid endarterectomies at our institution and who are included in our carotid follow-up registry. Reoperation was prompted by recurrent symptoms in 19/29 (65.5%) cases. Comparison of long-term stroke prevention in those patients who did (84% at 5 years, 78.6% at 10 years) and did not (90.3% at 5 years, 83.6% at 10 years) develop recurrent stenosis requiring reoperation revealed no statistically significant difference ( p = 0.48) when measured from the time of primary operation. The perioperative stroke and death rates for reoperation (3.4% and 0%) were acceptable. We conclude that with our acceptably low perioperative stroke morbidity (3.4%), surgery for recurrent carotid stenosis in symptomatic patients or in asymptomatic patients with high-grade (≥ 75%) stenosis maintains the durable stroke prevention offered by primary carotid endarterectomy. (J VASC SURG 1991;13:121-7.)
An Ecological Risk Assessment Framework for Effects of Onsite Wastewater Treatment Systems and Other Localized Sources of Nutrients on Aquatic Ecosystems

ABSTRACT An ecological risk assessment framework for onsite wastewater treatment systems and other localized sources of nutrients is presented, including problem formulation, characterization of exposure, characterization of effects, and risk characterization. The framework is most pertinent to the spatial scale of residential treatment systems located adjacent to small ponds, streams, or lagoons and some parts of shallow estuaries. Freshwater and estuarine ecosystems are distinguished based on differences in nutrient dynamics. Phosphorus exposure is the major determinant of phytoplankton production in most North American lakes. Nitrate can be directly toxic to aquatic biota such as amphibians. In shallow estuaries or lagoons, nitrogen is the primary stressor, which can be directly toxic to vegetation or can interact with biota to produce secondary stressors (limited light penetration, oxygen limitation, reduction in habitat, or reduction in forage vegetation or prey). Algal production, macrophyte product...
Quantitative extraction of thymine-thymine dimer from a large excess of thymine by preparative liquid chromatography

Abstract Extremely small amounts of thymine-thymine dimer can be extracted from thymine solutions using overloaded elution and shaving a narrow fraction at the front of the overloaded, later eluting thymine band. A two- or three-step procedure, involving the concentration and reinjection of the collected fraction, permits the preparation of solutions in which the ratio of the concentrations of the dimer and the monomer is close to unity compared with less than 1:25 000 in the original samples. The theory of non-linear chromatography and the semi-ideal model permits the accurate prediction of the location of the trace component band and the determination of the appropriate time to start and stop collection of the enriched fraction.
Unified total syntheses of fawcettimine class alkaloids: fawcettimine, fawcettidine, lycoflexine, and lycoposerramine B.

The total syntheses of the lycopodium alkaloids fawcettimine, fawcettidine, lycoflexine, and lycoposerramine B have been accomplished through an efficient, unified, and stereocontrolled strategy that relies on a Diels–Alder reaction to construct the cis-fused 6,5-carbocycles with one all-carbon quaternary center. Access to the enantioselective syntheses of both antipodes of those alkaloids can be achieved by kinetic resolution of the earliest intermediate via a Sharpless asymmetric dihydroxylation (Sharpless AD). Compared to existing approaches to these alkaloids, our synthetic route possesses superior stereocontrol over the C-4 and C-15 stereogenic centers as well as allowing for more functional variation on the 6-membered ring.
Monitoring and Predicting El Niño Invasions

Abstract Southern Oscillation indices (differences in sea level atmospheric pressure between Easter Island and Darwin, Australia, and between Juan Fernandez Island and Darwin) were treated so as to emphasize interannual changes and considered for monitoring unusual equatorial Pacific ocean-atmosphere developments and certain of their consequences (e.g., El Nino invasions). It now appears that their trends can be used to predict activity of El Nino intensity several months in advance.
The Leader Polypeptide of Theiler's Murine Encephalomyelitis Virus Is Required for the Assembly of Virions in Mouse L Cells

Deletion of the entire leader polypeptide of the GDVII strain of Theiler's murine encephalomyelitis virus (TMEV) results in the production of an attenuated virus that grows in baby hamster kidney (BHK) cells but cannot grow at all in mouse L-929 cells. This study examined the reasons for the failure of dl-L, the GDVII variant that lacks the leader polypeptide, to grow in mouse cells. At low multiplicities of infection, it was difficult to detect any viral proteins in mouse cells. However, levels of positive- and negative-strand RNA molecules were only moderately reduced in these infections. Viral RNA showed no major defect in translatability, as the mutant viral RNA was nearly as efficient as that of the wild-type (WT) virus in directing protein synthesis in vitro in assays using extracts prepared from mouse L cells. Viral protein synthesis was detected in dl-L-infected mouse cells as multiplicities of infection were increased and approached the levels observed in WT infections. Despite this, there was a total lack of virus production in high-multiplicity infections, and this was found to correlate with the failure of viral proteins and early virion precursors to assemble into virions in mouse cells. Thus, the inability of dl-L to grow in mouse cells reflects complex effects on various stages of the virus infection but is primarily a defect in virus assembly.
Effects of acute tobacco abstinence in adolescent smokers compared with nonsmokers.

Abstract Purpose Abstinence effects such as nicotine withdrawal and mood changes contribute to the maintenance of cigarette smoking in adult smokers, and emerging reports on adolescent smokers suggest they may experience similar subjective effects when deprived. This study aimed to prospectively document tobacco abstinence-induced changes during the first 48 hours of abstinence in adolescent smokers compared with nonsmokers, to distinguish effects distinct from typical adolescent lability. Methods Fifty-seven adolescent smokers and 44 adolescent nonsmokers were assessed during a 48-hour inpatient session. Characteristic nicotine withdrawal symptoms, cravings for cigarettes, and mood symptoms were measured at 13 time points following initiation of abstinence. Results The only abstinence-related effects observed were changes in craving for tobacco and feelings of anger. Tobacco craving increased and peaked quickly following initiation of abstinence and displayed a slight decrease toward the end of the 48-hour abstinence period, while anger symptoms peaked after a more prolonged abstinence. Overall, smokers' symptoms and cravings were positively associated with amount of daily smoking but not with reports of dependence or biological measures of extent of use. Conclusions We observed that among adolescent smokers, the primary effects associated with abstinence from cigarettes are relatively minimal, and include a heightened and persistent craving to smoke and increases in anger. Although smokers had greater negative mood symptoms compared with nonsmokers, the presence and severity of most of these symptoms appear to be minimally altered by abstinence and not associated with dependency or biological indicators of amount of tobacco use.
The iron(II)/reductant (DH2)-induced activation of dioxygen for the demethylation of N-methylanilines: Reaction mimic for the cytochrome P-450/reductase system

Abstract Several iron(II) complexes [Fe II L x ; Fe II (DPAH) 2 (DPAH 2 = 2,6-dicarboxyl pyridine), Fe II (PA) 2 (PAH = picolinic acid) and Fe II (bpy) 2 2+ (bpy = 2,2′-bipyridine)] in combination with a reductant [ D H 2 ; PhNHNHPh (mimic of dihydroflavin)] catalytically activate O 2 (1 atm) for the demethylation of N -methylanilines [PhN(CH 3 ) 2 , PhNH(CH 3 )]. This chemistry, which appears to involve a Fenton-like intermediate [ L x Fe IV OOH( D H) (1c)], mimics that of the cytochrome P-450 monooxygenase/reductase proteins.
Solution Conformation of the N-(Deoxyguanosin-8-yl)-1-aminopyrene ([AP]dG) Adduct Opposite dC in a DNA Duplex†

Combined NMR-molecular mechanics computational studies were undertaken on the C{sup 8}-deoxyguanosine adduct formed by the carcinogen 1-nitropyrene embedded in the d(C5-[AP]G6-C7){center_dot}d(G16-C17-G18) sequence context in a 11-mer duplex, with dC opposite the modified deoxyguanosine. The exchangeable and nonexchangeable protons of the aminopyrene moiety and the nucleic acid were assigned following analysis of two-dimensional NMR data sets in H{sub 2}O and D{sub 2}O solution. There was a general broadening of several proton resonances for the three nucleotide d(G15-C17-G18) segment positioned opposite the [AP]dG6 lesion site resulting in weaker NOEs involving these protons in the adduct duplex. The solution conformation of the [AP]dG{center_dot}dC 11-mer duplex has been determined by incorporating intramolecular and intermolecular proton-proton distances defined by upper and lower bounds deduced from NOESY spectra as restraints in molecular mechanics computations in torsion angle space. 73 refs., 8 figs., 2 tabs.
Translation and Dilation Invariance in Orthogonal Wavelets

Abstract A multiresolution analysis for an orthogonal family of wavelets is usually not translation invariant. A concept of weak translation invariance is introduced and shown to hold for a class of Meyer wavelets and in fact characterizes this class. Other operators such as dilation, differentiation, and convolution are shown to have similar invariance properties for the same class.
Overdose of Etizolam: The Abuse and Rise of a Benzodiazepine Analog

Author(s): O'Connell, Charles W; Sadler, Charlotte A; Tolia, Vaishal M; Ly, Binh T; Saitman, Alec M; Fitzgerald, Robert L
Quantitative quantum dynamics calculation of H2 + CH3 -> H + CH4 reaction

We report in this paper quantum dynamics calculation of state-selected reaction probabilities for a benchmark chemical reaction H2 + CH3 → H + CH4 on an ab initio potential energy surface. The quantum dynamics calculation is based on the recently developed semirigid vibrating rotor target (SVRT) model and involves six degrees of freedom. The present result is the first such high-level quantum dynamics calculation of microscopic reaction probability for a chemical reaction between two molecules with at least one of the reagents being larger than a diatomic molecule.
Correlation Analysis of Rate Constants for Dechlorination by Zero-Valent Iron

Dehalogenation is among the most important processes involved in contaminant fate, but despite all the work that has been done on the kinetics of dehalogenation, there are few linear free energy relationships (LFERs) that can be used to explain or predict rates of dehalogenation by environmental reductants. Previously, we summarized kinetic data for dehalogenation of chlorinated alkanes and alkenes by zero-valent iron (Fe0) and showed that correlation analysis of these data with published two-electron reduction potentials did not give a simple relationship. In this study, we report successful LFERs based on estimated lowest unoccupied molecular orbital (LUMO) energies calculated from semiempirical (AM1 and PM3) and ab initio methods (6-31G*) and one-electron reduction potentials. Solvation effects can be modeled with COSMO and incorporated into semiempirical estimates of ELUMO, but this did not improve the correlation with k. The best LFER (log k = −5.7−1.5 ELUMO) explains 83% of the variability in surfac...
Improved monochromatic imaging spectrometer.

Distortion inherent to a previously described system for acquisition of two-dimensional monochromatic spatial images is described. A solution is offered in the form of an improved instrument. The system uses a Czerny–Turner monochromator for spectral discrimination and a charge-coupled device (CCD) as the detector. A second Czerny–Turner monochromator, with identical dimensions, is added to correct the distortion, albeit with a slight loss in spatial resolution. With the earlier uncorrected arrangement, spatial resolution was on the order of 0.1 mm vertically and 0.3 mm horizontally, with a magnification of 0.52. With the same magnification, the new, corrected system offers spatial resolution of 0.1 mm vertically and 0.4 mm horizontally.
Immunologic consequences of intraocular implantation of retinal pigment epithelial allografts

Abstract Immune rejection is a major concern for potential therapeutic RPE transplantation. The purpose of this study is to determine the pattern and consequences of immune responses to intraocular retinal pigment epithelial (RPE) allografts. RPE allografts which derive from C57BL/6 newborn mice were implanted into the subretinal space (SR), anterior chamber (AC) and subconjunctival space (SCon) of the eyes of adult BALB/c mice. After implantation, clinical, histological and immunological examinations were conducted. Results revealed that RPE allografts implanted into SR and AC had a prolonged survival which is associated with a suppression of donor-specific delayed hypersensitivity (DH) for at least 12 days. In contrast, similar RPE grafts implanted into the SCon induced conventional DH and grafts were rejected. Moreover, previously healthy intraocular RPE grafts were rejected 2 weeks after a donor-specific challenge and rejection was accomplished with extensive cell infiltration which subsequently damaged intraocular tissue of the host eye. These results suggested that intraocular RPE allografts enjoyed immune privilege and induced a down-regulation of immune responses. However, this privilege is not absolute and static—DH was able to emerge and grafts were rejected in a cell-mediated fashion.
THE MORPHOLOGY OF THE BUD AND THE DEVELOPMENT OF THE LEAVES OF VIBURNUM RUFIDULUM

THE RAPIDLY increasing literature on the leaf and bud has been reviewed recently by Foster (1936a, 1928), Avery (1933), Schuiepp (1929), Zimmerman (1928), and others. The need for additional information is apparent to most workers, but there is some difference of opinion concerning the relative values of the various methods of study. Troll (1935) thought that ontogenetic studies are of relatively little valuethat the comparative study of a wide range of adult forms ("typological method") is of greater importance. On the other hand, Foster (1936a) pointed out that in developing our knowledge of the leaf " it would seem obvious that a sound and well balanced morphological treatment must attempt to relate the facts of development impartially to the form and structure of the adult organ." The " typological method " as an approach to the problem of foliar morphology is useful, but it seems that conclusions based upon such studies can hardly be considered trustworthy until comparative data concerning the growth processes of organs are assembled and correlated with the comparative studies of adult form. The value of a knowledge of the various histogenetic processes that occur in a leaf was recognized as early as 1872 by Lund, whose neglected monograph has been brought to the attention of modern workers (Foster, 1936b); and among recent investigators histogenetic studies have been and are being increasingly used in the interpretation of floral structures (Gregoire, 1935c; Newman, 1936). This report deals with the morphology of the bud and with the developmental behavior of the leaves of Viburnum rufidulum Raf., particularly with respect to the type, origin, and duration of meristems. The genus Viburnum (Tourn.) L. provides a good source of material for comparative foliar studies. Among the various species are some with highly specialized cataphylls (V. Opuluis L.), some with cataphylls lacking (V. Lantana L.), and others which seem to represent a position intermediate between these two extremes (V. rufidulum Raf., V. Lentago L.). Some species (V. Opulus) have lobed leaves with stipular appendages, others have leaves with entire margins and stipular appendages lacking. While this study will deal only with the structure and development of the foliar organs of Viburnum rufidulum, it is hoped that comparative studies can be made at an early date with V. Opulus (highly specialized cataphylls) and V. Lantana (naked buds). The researches of Cross (1937), Foster (1935a), and Schiiepp (1929) show that in some cases the foliar organs of plants with highly specialized cataphylls
Temperature programmed desorption at high pressures

Abstract The equations for temperature programmed desorption (TPD) are analyzed as a function of pressure in order to explore the dependences of rate and equilibrium parameters on conditions and to examine experimental conditions necessary to determine these parameters. For first order kinetics with coverage independent parameters, the peak shifts to higher temperatures with increasing pressures and becomes nearly symmetric and independent of heating rate as equilibrium adsorption is approached. Integration of the TPD spectrum with high pumping speeds then yields the equilibrium adsorption isobar directly. For dissociative adsorption the initially symmetric peaks become more asymmetric as equilibrium is approached. Numerical simulation indicates that a single binding state can exhibit structure in TPD when the adsorbate approaches equilibrium only at high temperatures. Experimental conditions necessary to determine parameters are discussed.
Photolytic debromination pathway of polybrominated diphenyl ethers in hexane by sunlight

The objective of this work is to identify the photolytic debromination pathways of polybrominated diphenyl ethers (PBDEs). Thirteen PBDEs (BDEs 209, 208, 207, 206, 196, 183, 154, 153, 100, 99, 85, 47 and 28) in hexane were individually exposed to sunlight for up to 64 h. A total of 180 PBDEs were screened and 74 BDE debromination products were detected. The disappearance rate constant increased exponentially with increasing number of bromines. While no evident difference in debromination preference among ortho, meta and para bromines was found for heavier congeners, the vulnerability rank order was meta ≥ ortho > para for the lighter congeners (≤8 Br). The total molar mass of PBDEs continuously decreased during sunlight exposure, indicating PBDEs were transformed to non-PBDE compounds. A stochastic least squares debromination pathway model was developed to simulate the reactions and determine the yields to extend the results beyond the experimental observations.
Adjoint perturbation method applied to two-stream radiative transfer

Abstract This paper describes a computationally efficient method for solving the plane parallel equation of radiative transfer for the two-stream fluxes based on the adjoint perturbation formulation. Analytical results for the perturbed fluxes are presented for a single layer atmosphere containing both solar and thermal sources. Simple linear and exponential corrections to the base state fluxes are explored. For the solar radiative transfer problem, the exponential form of the perturbation correction can accommodate deviations exceeding 400% in the base state optical properties while maintaining accuracy to within a few percent. For thermal radiative transfer, the linear form of perturbation relation is the more accurate, but unlike the solar problem, deviations from the base state optical properties must remain relatively small (less than 20%) if the errors in the computed fluxes are to remain within a few percent of the true fluxes. The method is applied to the calculation of broadband solar fluxes in a layer of scatterers embedded in an absorbing gas, where the absorption is modeled via the k-distribution method.
Identification of factors influencing implementation of construction robotics

The objective of this paper is to describe major factors influencing the robotization of construction processes, and to provide a model based on fuzzy set theory for feasibility analysis of robots. Major factors influencing implementation of construction robots are described. The primary factors driving the adoption of robotics in construction are identified as: (1) need-based feasibility, (2) technological feasibility, and (3) economic feasibility. In order to concentrate on processes which have potential and exclude those processes which are not strong candidates for automation, brainstorming sessions were held with various parties involved in construction to examine feasibility of construction processes for automation. The participants were asked to consider construction processes from the heavy and highway, building and industrial construction areas.
TIME COURSE OF PHOTOREACTIVATION OF UV‐INDUCED CHROMOSOMAL ABERRATIONS AND LETHAL DAMAGE IN INTERPHASE XENOPUS CELLS

— Sets of G1, S, and G2 phase Xenopus cells were exposed to 15.0 Jm−2 UV and their ability to photoreactivate the induced cell killing (loss of colony forming ability) and chromosomal aberrations was determined as a function of time following the UV exposure. Most of the lesions induced in G1 cells that lead to cell death were converted to a non-photoreactivable state before the cells entered the S phase, while lesions leading to chromosomal aberrations were converted to a non-photoreactivable state as the cells entered the S phase. In S phase cells the UV-induced lesions leading to aberrations appeared to be converted to a non-photoreactivable state at a much faster rate than those leading to cell death. A significant fraction of the lesions induced in G2 cells, that lead to cell death, were converted to a non-photoreactivable state before the progeny of the exposed cells reached the next succeeding S phase. Few, if any, lesions were induced in G2 cells that were expressed as aberrations at the first mitosis following exposure. Some of the lesions induced in the G2 cells led to aberrations that were observable in the progeny that progressed to the second mitosis following exposure. These lesions were converted to a non-photoreactivable state as the progeny of the exposed G2 cells progressed through the first S phase following exposure. These results suggest that the intracellular mechanism which expresses photoreactivable UV-induced lesions as cell death is not identical to the mechanism which expresses such lesions as chromosomal aberrations, and the two mechanisms operate with different efficiencies in different phases of the cell cycle.
BRCA1 185delAG mutant protein, BRAt, up-regulates maspin in ovarian epithelial cells.

Abstract Objective Aggressive clinical course and difficult detection of ovarian cancer are major challenges to improving patient survival and necessitate avid investigation into more effective therapeutic approaches. Understanding early molecular and pathological changes in high risk patients, such as BRCA1 mutation carriers, can provide candidates for molecular profiling and novel targets for effective therapies. Methods Using a culture model system for normal human ovarian surface epithelial cells with and without the BRCA1 185delAG frameshift mutation for the truncated protein product, BRAt, we investigated the role of BRAt in enhanced chemosensitivity. We used MTS, Western immunoblot, semi-quantitative RT-PCR, luciferase reporter and siRNA assays, to identify novel downstream targets of BRAt that promote apoptosis following chemotherapeutic treatment. Results We identified maspin as a novel downstream target of BRAt. BRAt increases maspin expression with preferential nuclear localization of maspin. Further, Brat-mediated maspin expression is transcriptionally regulated through an AP1 site within the (−520) to (−297) region of the promoter. Lastly, BRAt, enhances chemosensitivity in normal ovarian surface epithelial cells through c-Jun by a mechanism that may involve maspin. Conclusions BRAt-mediated enhanced chemosensitivity correlates clinically with enhanced chemotherapeutic response in BRCA1 mutation carriers. BRAt-mediated maspin expression also correlates with improved prognostic outlook for ovarian tumors with high levels of nuclear maspin. Consequently, understanding early genotypic and phenotypic changes in the context of high risk disease may provide a better understanding of the mechanism of mutation-associated ovarian cancer and provide new targets for therapeutic intervention.
Solar oscillations with 13-day period

Reference is made to the solar observations made by Claverie et al. (1982) over a three-month period in the summer of 1981 which show oscillatory velocity with a period of 13.1 days and amplitude of 6.6 m/s. These investigators reject the possibility that they see the Doppler shift from a radial oscillation, because the amplitude is implausibly large. They also do not believe that their signal was induced by solar magnetic fields, since typical mean solar fields are too small. Photo-electric drift-scan measurements of the solar diameter and full-disk magnetograms taken at Kitt Peak National Observatory are examined here for evidence of variations corresponding to the velocity oscillations of the 13.1-day period. An upper limit on radius variations is reported which is a factor of six below the amplitude needed to explain the velocity observations as a radial oscillation. Attention is also given to the possible role of the rotation of large-scale surface magnetic features.
Pipe Flow Models of a Kentucky Limestone Aquifer

A digital computer program which simulates a limestone aquifer as a pipe network was written and compared with the Sinkhole Plain aquifer of west-central Kentucky. Model 1, which considers the flow in the network to be laminar, yielded values of head, flow in the network, and discharge at the bounding streams which are in reasonably good agreement with field observations. The over-all hydraulic conductivity of the aquifer appears to be about 5600 meinzers if the zone of active flow is 30 meters thick, but the northeastern portion of the aquifer probably has a higher transmissivity. The indicated location of the principal ground-water divide agrees well with data derived from wells and from tracing underground-water flows. A second model (Model 2) was constructed which considers flow in the network to be turbulent. Although this model yields values which differ from Model 1, the differences are too small to allow the mode of flow in the aquifer to be distinguished using observational data.
On the mechanism of a novel 3(2H)‐Furanone‐2(5H)‐furanone rearrangement

Transposition de l'acide anilino-3 dihydro-4,5 oxo-4 furoique-3 en le phenylamide de l'acide anilino-4 dihydro-2,5 oxo-2 furoique-3; isolation et etude cristallographique de l'intermediaire: phenylamide de l'acide dihydro-2,5 ethoxy-4 oxo-2 furoique-3
Olig1 function is required for remyelination potential of transplanted neural progenitor cells in a model of viral-induced demyelination

Abstract Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) resulting in cumulative neurologic deficits associated with progressive myelin loss. We have previously shown that transplantation of neural progenitor cells (NPCs) into mice persistently infected with the JHM strain of mouse hepatitis virus (JHMV) results in enhanced differentiation into oligodendrocyte progenitor cells (OPCs) that is associated with remyelination and axonal sparing. The current study examines the contributions of the transcription factor Olig1 on NPC differentiation and remyelination. Under defined conditions, NPCs preferentially differentiate into oligodendroglia whereas NPCs isolated from Olig1-deficient ( Olig1 −/− ) mice exhibit enhanced differentiation into astrocytes. Transplantation of Olig1 −/− and Olig1 +/+ NPCs into JHMV-infected mice resulted in similar cell survival, proliferation, and selective migration to areas of demyelination. However, only recipients of wild type NPCs exhibited extensive remyelination compared to mice receiving Olig1 −/− NPCs. In vivo characterization of NPCs revealed that Olig1 +/+ NPCs preferentially differentiated into NG2-positive OPCs and formed processes expressing myelin basic protein that encircled axons. In contrast, the majority of transplanted Olig1 −/− NPCs differentiated into GFAP-positive cells consistent with the astrocyte lineage. These results indicate that exogenous NPCs contribute to improved clinical and histological outcome and this is associated with remyelination by this donor population. Further, these findings reveal that Olig1 function is required for the remyelination potential of NPCs after transplant, through specification and/or maintenance of oligodendroglial identity.
Keratan sulfate proteoglycan isolated from the estrogen-induced medullary bone in Japanese quail.

Abstract 1. 1. Two proteoglycans isolated from the femurs of quail actively producing medullary bone were separated using DEAE Bio-Gel A. 2. 2. The first to elute in the gradient was a keratan sulfate proteoglycan with an average buoyant density of 1.53 g/ml and a K av = 0.57 on Sepharose CL-4B. 3. 3. The second proteoglycan to elute contained chondroitin 4-sulfate. 4. 4. Apparently only the keratan sulfate proteoglycan is associated with the new medullary bone matrix.
The effect of boundary geometry on Hankel operators belonging to the trace ideals of Bergman spaces

The characterization of thosef for which the Hankel operatorsHf belongs to various trace ideals over Bergman spaces on pseudoconvex domains of finite type in complex dimension two is given. In particular, we determine how the cutoff values are affected by the boundary geometry.
Earthquake multiplets in the southeastern Solomon Islands

The 350-km stretch of the Solomon Islands trench that lies adjacent to the islands of Guadalcanal and San Cristobal has been the site of 10 large shallow earthquakes since 1966: June 15, 1966 doublet (M_s = 7.7,7.3), May 20, 21, 1977 quadruplet (M_s = 6.7,7.5,7.5,7.5), November 4,5, 1978 doublet (M_s = 6.9,7.1), and two single events on October 23, 1979 (M_s = 7.1) and February 7, 1984 (M_s = 7.7). Analyses of P-wave first-motions, aftershock distributions, P-wave-forms recorded at epicentral distances of 30° to 90° on the WWSSN, and 256 s-period Rayleigh-wave spectra obtained from the IDA and GDSN networks are used to examine the source characteristics of the events. The close temporal association and large size of earthquakes precluded collection of useful seismograms for the latter of the two 1966 events and the second and third events of the 1977 sequence. P-waveforms analyzed show smooth traces that can be modeled with simple trapezoidal source-time functions located at shallow (15–45 km) depths. Focal mechanisms are consistent with oblique subduction of the Indian plate beneath the Pacific plate at about N73°E. Estimates of seismic moment for individual events range from 0.2 to 2.3 × 10^(27) dyne-cm. Average stress drops of the sequences are estimated to range between 10 and 40 bars. This section of island arc may have ruptured in a similar sequence of earthquakes during the 1930's. Conversion of the cumulative seismic moment to displacement and averaging over 40 years suggests a convergence rate of about 4.5 cm year^(−1), about one half of the rates that have been assessed on the basis of seafloor magnetic lineations.
Rheological Changes During Gelation of High-Methoxyl Pectin/Fructose Dispersions: Effect of Temperature and Aging

Gels made with 0.5% and 1% pectin in 60% fructose, and a commercial sample exhibited macromolecular solution/weak gel behavior. Cooling the gels from 50–10°C increased storage (G') and loss moduli (G') of the gels. As the rate of cooling (10, 5.7, and 2.5°C/hr) a 1% pectin, 60% fructose, dispersion increased, the elasticity of the formed gel decreased; however, G' was not affected much by rate of cooling. During the first 24 hr, the changes in G'and G' were small. After 14 days storage at ambient temperature, G’values of gels increased substantially, while G' values increased slightly.
Photoactivated enediynes: targeted chimeras which undergo photo-Bergman cyclization

Chimeric enediynes composed of a photoactivatable warhead coupled either to a porphyrin or spiroalcohol have been prepared. The molecules underwent photoactivation to produce diaryl radicals paving the way for applications in targeted photodynamic therapy.
Autoimmune phenomena in ataxia telangiectasia.

Eighteen patients with ataxia telangiectasia were studied for evidence of autoimmune phenomena. Forty-five per cent (8/18) were positive for one or more of the following autoantibodies: antithyroglobulin, antismooth muscle, antiparietal cell, antistriated muscle, antitubular basement membrane, antimitochondria, antibile canaliculi, and anti-IgG. The similarity of certain of the clinical and laboratory features of patients with ataxia telangiectasia to those found in animals thymectomized at birth suggests that the thymus may play a role in the development of autoimmune phenomena, either directly or secondarily by predisposing to chronic infection with an as yet unknown agent.
Shell-model calculations for p-shell hypernuclei

Abstract The interpretation of hypernuclear γ-ray data for p-shell hypernuclei in terms of shell-model calculations that include the coupling of Λ- and Σ-hypernuclear states is briefly reviewed. Next, Li Λ 8 / Be Λ 8 and Li Λ 9 are considered, both to exhibit features of Λ–Σ coupling and as possible source of observed, but unassigned, hypernuclear γ-rays. Then, the feasibility of measuring the ground-state doublet spacing of Be Λ 10 , which, like Li Λ 9 , could be studied via the ( K − , π 0 γ ) reaction, is investigated. Structural information relevant to the population of states in these hypernuclei in recent ( e , e ′ K + ) studies is also given. Finally, the extension of the shell-model calculations to sd-shell hypernuclei is briefly considered.
Managerial decision-making under crisis: The role of emotion in an intuitive decision process

Abstract Today's manager is increasingly expected to make decisions based on paradigms that depart from traditional rationality and information processing models. This is particularly so under crisis conditions, where there is little time and information available for choice consideration. While the management literature has recently seen more empirical and theoretical support for intuition and tacit knowledge in the decision process, the role of emotion has not played a prominent role. This article advances management decision theory by proposing a conceptual model of managerial decision-making that underscores the role of emotions in an intuitive decision process under crisis conditions. The article holds particular salience to human resource managers, as they are the custodians of decisions made about people in the organization. These decisions, by definition, carry much weight in both ethical and financial terms, and their importance is magnified immeasurably under crisis conditions.
Controlled sintering for optimized debinding in powder injection moulding

Abstract A high temperature batch furnace has been constructed for real-time analysis of sample weight, compact temperature profile and evolved gas composition using various gas analysis methods. The furnace has digital mass flow controllers for atmosphere composition control. A separate precision dilatometer is used to provide dimensional change data. These analytical capabilities are controlled by a microprocessor coupled to a control computer which records the output from the various sensors. The long range goal is to develop an expert systems software to fully govern the thermal and atmosphere cycle in a closed-loop feedback mode. This will allow optimization of the sintering pathway for any material, processing objectives, and component geometry. In addition, the equipment will be used to investigate the debinding cycle of powder injection moulded (PIM) parts. By varying the heating rate, time at temperature, and atmosphere during the debinding cycle, the debinding mechanisms and rate controlling parameters can be identified. The goal of these experiments is to significantly lower the debinding time while maintaining compact integrity. A model for optimized processing is being developed in parallel with these experiments.
Evidence for LHRH-receptor expression in human airway epithelial (Calu-3) cells and its role in the transport of an LHRH agonist.

Purpose. To determine whether LHRH-receptor is expressed in Calu-3, a human bronchial epithelial cell line, and to further determine whether this receptor plays a role in the transport of deslorelin, an LHRH agonist.
Time to nail inflation

Commentary: NASA isn't going ahead with an experiment to look for signals of cosmic inflation, but that shouldn't discourage future attempts, says Lawrence Krauss
Interpreting linguistically quantified propositions

We discuss the idea of a linguistic quantifier and fuzzy set representations of these objects. We describe two formalisms for evaluating the truth of linguistically quantified propositions such as Most winter days are cold. the first approach is based upon a probabilistic interpretation and the second is based upon a logical interpretation, and uses a generalization of the “and” and “or” operations via OWA operators. We suggest an application of these quantified statements for the representation of the quotient operator in fuzzy relational data bases. © 1994 John Wiley & Sons, Inc.
Racial and ethnic differences in risk factors associated with suicidal behavior among young adults in the USA

Objective. The objectives of this study are to examine racial and ethnic differences in suicidal behaviour, its main risk factors, and the effect of the risk factors on suicidal behaviour in young adults in the United States.Design. Using nationally representative data (n = 10,585) from Add Health, we calculate the prevalence of suicidal behavior and associated risk factors for non-Hispanic White, non-Hispanic Black, and Hispanic youth (aged 18–26) using logistic regression models of suicidal ideation stratified by race.Results. Non-Hispanic White and Hispanic young adults have higher rates of suicidal ideation than their non-Hispanic Black counterparts, but racial/ethnic differences in attempts are not statistically significant. Non-Hispanic Whites and Hispanic young adults are more likely to possess key risk factors for suicide. With the exception of substance use variables (i.e. alcohol and marijuana use) which appear to be more conducive to suicidal ideation in non-Hispanic Black than in non-Hispanic ...