cssi/SciSciGPT-SciSciNet huggingface dataset:
TU‐C‐BRB‐03: Hazards of a Tungsten Multi‐Leaf Collimator in Proton Beam Therapy

Purpose: Charged particle therapy, especially proton therapy is a growing treatment modality worldwide. A direct transfer of the MLC technology to proton therapy seems intuitively straightforward as leakage radiation is not a concern. On the other hand, neutron production and induced radioactivity in tungstenMLC are critical issues that are the subjects of the present study. Methods: We have performed a study with FLUKA Monte Carlo simulation, of the neutron generation, ambient dose equivalent (H*(10)), and activation of a typical tungstenMLC and compared with those obtained from a brass aperture used for proton therapy. Results: With the tungstenMLC, the secondary neutrondose to patient is at least 1.6 times higher than that from the brass aperture. This may lead to an increase on the risk of secondary cancer. The buildup of activity in MLC (30 patients per day) is about 3.4 times higher than that for the brass aperture at the end of 40‐day treatment. The residual activity decreases by a factor of 2 after 40 days of MLC cooling, but still is about 7600 times higher than the activity for the brass aperture. The utilization of the MLC at the end of the operation cycle will require prolonged storage for cooling due to W‐181 and Ta‐179. There are also risks of MLC electronic malfunctioning associated with the soft error caused by secondary neutrons. The tritium production in tungstenMLC as a result of its daily use in the clinic is also estimated. Conclusions: MLC could be an efficient way for beam shaping, an efficient cost reduction option for proton therapy. However, tungstenMLC does not seem to be suitable for proton therapy. Usage of tungsten MCL in clinic will create unnecessary risks associated with the secondary neutrons and induced radioactivity for patients and staff.
Stress Annealing in Vacuum Deposited Copper Films

An apparatus has been built for the measurement of mechanical stress in vacuum deposited films. A study of the stress changes during pulse annealing has been made with copper films deposited at several substrate temperatures between -150°C and +75°C. The annealing spectrum shows a prominent peak centred near room temperature which matches a resistance annealing peak in similar films and also in cold worked copper. The fall of tensile stress in this region suggests a vacancy mechanism. The theory of Murbach and Wilman for the behaviour of initial stress with temperature is not supported by these results.
Effects of chlordane and methylmercury on the metabolism of carbaryl and carbofuran in rats

Abstract Methylmercury hydroxide pretreatments (10 mg/kg/day for 2 days) decreased hepatic microsomal cytochrome P-450 levels and mixed function oxidase activity over twofold, while chlordane pretreatments (20 mg/kg/day for 2 days) induced the oxidative enzymes nearly twofold. Methylmercury hydroxide pretreatments also decreased microsomal hydroxylation reactions of carbaryl and carbofuran to form 4-hydroxy carbaryl, N-hydroxymethyl carbaryl and 3-hydroxy carbofuran. Chlordane pretreatments increased hydroxylation rates at these positions and also increased the amount of carbamate-14C equivalents detected in the water-extractable fraction. When chlordane and methylmercury hydroxide were administered simultaneously the effects balanced out so that carbamate metabolism using microsomes from this group was similar to controls. In whole animal metabolism studies, chlordane pretreatment increased the rate of urinary elimination of carbaryl and carbofuran equivalents. Methylmercury hydroxide, unexpectedly, also increased urinary excretion of both carbamate equivalents and possible mechanisms involved in the enhancement of urinary excretion are investigated. Chlordane and methylmercury hydroxide pretreatment did not qualitatively alter microsomal or urinary carbamate metabolites, although some quantitative differences were observed.
Synthesis, assembly, and characterization of monolayer protected gold nanoparticle films for protein monolayer electrochemistry.

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently incorporated into film assemblies that serve as adsorption platforms for protein monolayer electrochemistry (PME). PME is utilized as the model system for studying electrochemical properties of redox proteins by confining them to an adsorption platform at a modified electrode, which also serves as a redox partner for electron transfer (ET) reactions. Studies have shown that gold nanoparticle film assemblies of this nature provide for a more homogeneous protein adsorption environment and promote ET without distance dependence compared to the more traditional systems modified with alkanethiol self-assembled monolayers (SAM).1-3 In this paper, MPCs functionalized with hexanethiolate ligands are synthesized using a modified Brust reaction4 and characterized with ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and proton (1H) nuclear magnetic resonance (NMR). MPC films are assembled on SAM modified gold electrode interfaces by using a "dip cycle" method of alternating MPC layers and dithiol linking molecules. Film growth at gold electrode is tracked electrochemically by measuring changes to the double layer charging current of the system. Analogous films assembled on silane modified glass slides allow for optical monitoring of film growth and cross-sectional TEM analysis provides an estimated film thickness. During film assembly, manipulation of the MPC ligand protection as well as the interparticle linkage mechanism allow for networked films, that are readily adaptable, to interface with redox protein having different adsorption mechanism. For example, Pseudomonas aeruginosa azurin (AZ) can be adsorbed hydrophobically to dithiol-linked films of hexanethiolate MPCs and cytochrome c (cyt c) can be immobilized electrostatically at a carboxylic acid modified MPC interfacial layer. In this report, we focus on the film protocol for the AZ system exclusively. Investigations involving the adsorption of proteins on MPC modified synthetic platforms could further the understanding of interactions between biomolecules and man-made materials, and consequently aid the development of biosensor schemes, ET modeling systems, and synthetic biocompatible materials.5-8
Measurements of electron density profiles using an angular filter refractometera)

A novel diagnostic technique, angular filter refractometry (AFR), has been developed to characterize high-density, long-scale-length plasmas relevant to high-energy-density physics experiments. AFR measures plasma densities up to 1021 cm−3 with a 263-nm probe laser and is used to study the plasma expansion from CH foil and spherical targets that are irradiated with ∼9 kJ of ultraviolet (351-nm) laser energy in a 2-ns pulse. The data elucidate the temporal evolution of the plasma profile for the CH planar targets and the dependence of the plasma profile on target radius for CH spheres.
Formation of HNK-1 Determinants and the Glycosaminoglycan Tetrasaccharide Linkage Region by UDP-GlcUA:Galactose β1,3-Glucuronosyltransferases

While expression-cloning enzymes involved in heparan sulfate biosynthesis, we isolated a cDNA that encodes a protein 65% identical to the UDP-GlcUA:glycoprotein β1,3-glucuronosyltransferase (GlcUAT-P) involved in forming HNK-1 carbohydrate epitopes (3OSO3GlcUAβ1,3Gal-) on glycoproteins. The cDNA contains an open reading frame coding for a protein of 335 amino acids with a predicted type II transmembrane protein orientation. Cotransfection of the cDNA with HNK-1 3-O-sulfotransferase produced HNK-1 carbohydrate epitopes in Chinese hamster ovary (CHO) cells and COS-7 cells. In vitro, a soluble recombinant form of the enzyme transferred GlcUA in β-linkage to Galβ1,3/4GlcNAcβ-O-naphthalenemethanol, which resembles the core oligosaccharide on which the HNK-1 epitope is assembled. However, the enzyme greatly preferred Galβ1,3Galβ-O-naphthalenemethanol, a disaccharide component found in the linkage region tetrasaccharide in chondroitin sulfate and heparan sulfate. During the course of this study, a human cDNA clone was described that was thought to encode UDP-GlcUA:Galβ1,3Gal-R glucuronosyltransferase (GlcUAT-I), involved in the formation of the linkage region of glycosaminoglycans (Kitagawa, H., Tone, Y., Tamura, J., Neumann, K. W., Ogawa, T., Oka, S., Kawasaki, T., and Sugahara, K. (1998) J. Biol. Chem.273, 6615–6618). The deduced amino acid sequences of the CHO and human cDNAs are 95% identical, suggesting that they are in fact homologues of the same gene. Transfection of a CHO cell mutant defective in GlcUAT-I with the hamster cDNA restored glycosaminoglycan assembly in vivo, confirming its identity. Interestingly, transfection of the mutant with GlcUAT-P also restored glycosaminoglycan synthesis. Thus, both GlcUAT-P and GlcUAT-I have overlapping substrate specificities. However, the expression of the two genes was entirely different, with GlcUAT-I expressed in all tissues tested and GlcUAT-P expressed only in brain. These findings suggest that, in neural tissues, GlcUAT-P may participate in both HNK-1 and glycosaminoglycan production.
Thermosolutal convection in a floating zone: the case of an unstable solute gradient

Abstract The influence of laminar thermosolutal convection on solute segregation and heat transfer in the floating zone crystal growth of a dilute binary alloy is considered. The solute gradient is assumed to be destabilizing, and the thermal gradient is assumed perpendicular to it. The evolution of non-linear states from the critical points predicted by linear theory is studied. For vanishing thermal Rayleigh numbers, two solutions, corresponding to upflow and downflow at the meniscus, are obtained. The presence of side heating establishes upflow as the preferential direction; the downflow solution is found to persist for low thermal Rayleigh numbers. Flow and heat transfer for high thermal Rayleigh numbers are also computed.
The study of interfaces of epitaxial Ag films on (001) GaAs

Abstract The interface structures of Ag films on (001) GaAs substrates with and without an Fe buffer, grown by molecular-beam epitaxy technique, were investigated with transmission electron microscopy. Although both epitaxial films are (001) orientated, cross-sectional observation reveals different in-plane orientation relationships. The buffer-free Ag film holds an orientation relationship of (001) Ag (001) GaAs, [100] Ag [100] GaAs, whereas the relation for the Fe-buffered Ag film is (001) Ag (001) Fe (001) GaAs, [100] Ag [110] Fe [110] GaAs. Lattice images do not reveal any significant reaction layer between the films and GaAs substrates. The rough GaAs surface does not affect the nucleation and growth of Fe and Ag films significantly, but can induce misfit dislocations in Ag films. The observed orientation relationships of films are discussed with respect to the effects of pre-cleaning, lattice mismatch, and possible surface structure and reconstruction of the GaAs surface.
Fine structure in elastic-electron-yield spectra at transition-metal core energies

We present yield spectra of electrons elastically backscattered from surfaces of NiO, Cr/sub 2/O/sub 3/, and Cu. The chromium- and nickel-oxide surfaces show fine structure above the 2p core excitation energies of the transition metals. The fine structure extends above the core threshold for at least 100 eV and is periodic in the free momentum of an excited 2p core electron at energies well above the bottom of the conduction band. We interpret the structure in terms of a model based on final-state interference of the excited electron. Accurate recovery of nearest-neighbor atomic distances may require consideration of multiple scattering.
Crystal Structures of EF-G–Ribosome Complexes Trapped in Intermediate States of Translocation

Introduction: One of the most critical and complex steps of protein synthesis is the coupled translocation of mRNA and tRNAs (mRNA and tRNAs) through the ribosome, catalyzed by the guanosine triphosphatase (GTPase) elongation factor EF-G. Although several of the main steps have been identified, the underlying molecular mechanisms of translocation are poorly understood. A central question is how structural rearrangements in the ribosome are coupled to movement of mRNA and tRNA. Methods: We trapped and crystallized complexes of Thermus thermophilus ribosomes bound with EF-G, mRNA, and tRNA, using the antibiotic fusidic acid (which prevents release of EF-G after GTP hydrolysis) or the nonhydrolyzable GTP analog GDPNP, in intermediate states of translocation. Their crystal structures were determined to resolutions from 3.5 to 4.1 A. Results: The structures of the fusidic acid complex (Fus) and two GDPNP complexes (GDPNP-I and GDPNP-II) reveal conformational changes occurring during intermediate states of translocation, including large-scale (15° to 18°) rotation of the 30 S subunit head and 3° to 5° rotation of the 30 S body. In all complexes, the tRNA acceptor end has moved from the 50 S subunit P site to the 50 S E site, while the anticodon stem loop (ASL) and mRNA move with the head of the 30 S subunit to positions between the P and E sites, forming chimeric pe*/E intermediate states. The elongated, mobile domain IV of EF-G moves to contact the head of the 30 S subunit and the backbone of the mRNA. Two universally conserved bases of 16 S rRNA that intercalate between bases of the mRNA may act as “pawls” of a translocational ratchet. In the GDPNP complexes, structuring of the conserved switch loop I segment, which was disordered in previous structures, completes the cage that encloses GDPNP and fixes the relative geometry of EF-G domains I, III, and V. In the Fus complex, the position of fusidic acid overlaps that of switch loop I, stabilizing contacts between domains I and III that are normally made by the structured switch loop. Conclusion: Our structures capture intermediate states of the rate-limiting step of translocation, in which movement of the tRNA ASL and mRNA is coupled to rotational movement of the 30 S subunit head. Slippage of the translational reading frame during reverse rotation of the head during translocation may be prevented by intercalation of bases C1397 and A1503 of 16 S rRNA, which project from the body of the 30 S subunit, between mRNA bases. The antibiotic fusidic acid appears to stabilize binding of EF-G to the ribosome in the GDP state by mimicking the structure of the conserved core of switch loop I of EF-G in the GTP state.
Constant-volume constraint and many-body forces in the Nilsson model

It is shown that the Nilsson prescription for calculating equilibrium deformations of nuclei under the constraint of constant volume may be interpreted in terms of a Hartree mean-field approximation applied to nucleons interacting via many-body forces. Such an interaction is obtained in closed form, having a Taylor expansion beginning with the familiar quadrupole-quadrupole interaction, and then successively adding three-body, four-body, etc., terms. Since the interaction is not uniquely determined, two interesting forms are discussed. One, having both monopole and quadrupole parts, has a Hartree field identical to the Nilsson potential. The other, which is purely quadrupole, permits a generalization to all orders of a result obtained by Moszkowski for small deformations. The scalar many-body interaction naturally explains the nonscalar effective two-body interactions used in random-phase approximation calculations of deformed nuclei.
The increased use of diagnostic procedures in patients with acute myocardial infarction: a community-wide perspective

• As part of a community-wide study examining time trends in the incidence and case-fatality rates of 3263 patients hospitalized with validated acute myocardial infarction (MI) during the years 1975,1978,1981, and 1984, we examined changes over time in the use of various noninvasive and invasive diagnostic tests during hospitalization for acute MI. In terms of the noninvasive procedures, exercise testing before hospital discharge increased from only 0.1% of patients in 1975 to 40.3% in 1984, while use of echocardiography (2.5%, 1975; 15.3%, 1984), Holter monitoring (1.0%, 1975; 34.0%, 1984), and radionuclide ventriculography (2.6%, 1975; 52.7%, 1984) also increased dramatically. Concerning the invasive procedures, use of coronary arteriography in patients with acute MI increased from 3.1% in 1975 to 9.8% in 1984. A more striking increase was noted in the use of pulmonary artery catheterization (7.2%, 1975; 19.9%, 1984). Examination of patient characteristics associated with the use of these tests demonstrated that the increased use of these diagnostic procedures was not due to changes in the clinical characteristics of patients hospitalized with acute MI; rather, it was the result of changes in physician practice patterns. If the practice patterns seen in this community-based study are similar to those seen throughout the United States, the charges for these diagnostic tests in 1984 are estimated to approach 600 million dollars. Given current interest in cost-containment and evaluation of clinical practices, these results suggest the need for further observational studies and clinical trials to assess the cost-effectiveness of these diagnostic tests. To assess the cost-effectiveness, it will be necessary to determine if the use of these tests improves the short-term or long-term prognosis of patients hospitalized with acute MI. ( Arch Intern Med 1987;147:1729-1732)
Weak-acid uncouplers of oxidative phosphorylation. Mechanism of action on thin lipid membranes

Abstract Weak-acid uncouplers of oxidative phosphorylation such as p -trifluoromethoxycarbonylcyanidephenylhydrazone, tetrachloro-2-trifluoromethylbenzimidazole, m -chlorocarbonylcyanidephenylhydrazone, and 2,4-dinitrophenol can increase the conductance of thin lipid membranes by several orders of magnitude. In this high conductance state these membranes appear to be ideally selectively permeable to H + or OH − . We suggest, however, that the primary charge carrier in the membrane is neither H + or OH − , but rather a dimer formed between the undissociated and dissociated form of the weak acid, and we show that all of the data on the action of these weak acids on thin lipid membranes are consistent with this picture.
The relationship between quantum and classical correlation in games

Abstract Quantum games have been argued to differ from classical games by virtue of the quantum-mechanical phenomenon of entanglement. We formulate a baseline of classical correlation – which takes two forms according as signals added to the game are or are not required to be independent of chance moves in the underlying game. We show that independence is a necessary condition for the addition of quantum signals to have a different effect from the addition of classical signals.
The effects of the social context on performance evaluations

Abstract The study is designed to test the impact of group composition variables on the supervisor's ratings of subordinates. In a laboratory study subjects play the role of supervisors evaluating the performance of their subordinates. The information about subordinate performance is constructed such that one subordinate performs poorly while two others perform well. The poor performer is represented as being high or low in group social skills and high or low in group leadership skills as rated by the other group members, creating a 2 × 2 design (the two good performers are portrayed as being average in social and leadership skills). The supervisor rates the poor performer more positively and the good performers more negatively when the poor performer is high in social and/or leadership skills than when he or she is low on these factors. A field study using critical incidents demonstrates that less severe responses are directed toward a popular group member. Implications of these findings for theory and practice are discussed.
Calpain Mediates Epithelial Cell Microvillar Effacement by Enterohemorrhagic Escherichia Coli

A member of the attaching and effacing (AE) family of pathogens, enterohemorrhagic Escherichia coli (EHEC) induces dramatic changes to the intestinal cell cytoskeleton, including effacement of microvilli. Effacement by the related pathogen enteropathogenic E. coli (EPEC) requires the activity of the Ca+2-dependent host protease, calpain, which participates in a variety of cellular processes, including cell adhesion and motility. We found that EHEC infection results in an increase in epithelial (CaCo-2a) cell calpain activity and that EHEC-induced microvillar effacement was blocked by ectopic expression of calpastatin, an endogenous calpain inhibitor, or by pretreatment of intestinal cells with a cell-penetrating version of calpastatin. In addition, ezrin, a known calpain substrate that links the plasma membrane to axial actin filaments in microvilli, was cleaved in a calpain-dependent manner during EHEC infection and lost from its normal locale within microvilli. Calpain may be a central conduit through which EHEC and other AE pathogens induce enterocyte cytoskeletal remodeling and exert their pathogenic effects.
Surface plasmon dispersion for very small metallic spheres: A quantum mechanical formulation

We have derived a pair of matrix equations describing the surface plasmon dispersion for a very small spherical metal particle, using the quantum mechanical random-phase approximation (RPA). The surface of the sphere is represented by an infinite spherical potential well for the conduction electrons and the positive ions are assumed to be uniformly distributed into a “jellium”. The dispersion relation is obtained as the condition that a solution of the RPA integral equation for charge fluctuation would exist for the particle.
Psychopathology as Disability

Bergner, following an earlier article by Ossorio, has proposed that psychopathology be defined as a deficit in the ability to engage in deliberate action or to participate in the social practices of the community. Several criticisms of this definition are offered.
Depth of anesthesia.

Purpose of reviewThe present review article provides a summary of the recent literature evaluating the technology for monitoring depth of anesthesia and patient outcomes associated with its use.Recent findingsThe tentative and controversial findings of a 2006 study suggesting a correlation of mortal
Evolution of ion-charge-state distributions in an electron-beam ion trap

We present measurements and calculations of the evolution of the ion-charge-state distributions in an electron-beam ion trap. Direct measurements of the charge-state distributions are made with an ion extraction system. The data are used to test our computer model, which solves the set of coupled nonlinear differential equations for the energy and charge balance for all ionic species. The model is used to assess the importance of various processes in establishing the charge-state distribution.
New species of Prepseudatrichia Kelsey, 1969 from Thailand (Diptera, Scenopinidae)

A new species of Prepseudatrichia Kelsey, 1969 (Prepseudatrichia tiger sp. n.) is described from Thailand, the first record of the genus from the Oriental region. A key to world species of Prepseudatrichia is given.
Coupling of adenylate cyclase to lipolysis in permeabilized adipocytes: direct evidence that an antilipolytic effect of insulin is independent of adenylate cyclase.

In digitonin-permeabilized adipocyte suspensions, adenylate cyclase activation was analyzed by an in situ assay and compared to lipolytic activity which was determined under essentially identical assay conditions. This approach permitted direct comparison of the regulatory responses of these two processes. Adenylate cyclase was activated by isoproterenol in permeabilized adipocytes, but digitonin caused a decrease in sensitivity to the β-agonist. On the other hand, activation of adenylate cyclase by forskolin and NaF was unaffected by digitonin. Inhibition of isoproterenol-activated adenylate cyclase by propranolol was also unaffected by digitonin. These observations are consistent with a partial uncoupling by digitonin of the interaction between occupied β-adrenergic receptors and the stimulatory GTP-binding component (N8). Despite permeabilization, adenylate cyclase activity retained the capability to activate the lipolytic pathway. Activation of adenylate cyclase and lipolysis by isoproterenol was firs...
Impact of a single-day multidisciplinary clinic on the management of patients with liver tumours.

Purpose Multidisciplinary cancer clinics may improve patient care. We examined how a single-day multidisciplinary liver clinic (mdlc) affected care recommendations for patients compared with the recommendations provided before presentation to the mdlc. Methods We analyzed the demographic and clinicopathologic data of 343 patients assessed in the Johns Hopkins Liver Tumor Center from 2009 to 2012, comparing imaging and pathology interpretation, diagnosis, and management plan between the outside provider (osp) and the mdlc. Results Most patients were white (n = 259, 76%); median age was 60 years; and 146 were women (43%). Outside providers referred 182 patients (53%); the rest were self-referred. Patients travelled median of 83.4 miles (interquartile range: 42.7–247 miles). Most had already undergone imaging ( n = 338, 99%) and biopsy ( n = 194, 57%) at the osp, and a formal management plan had been formulated for about half ( n = 168, 49%). Alterations in the interpretation of imaging occurred for 49 patients (18%) and of biopsy for 14 patients (10%). Referral to the mdlc resulted in a change of diagnosis in 26 patients (8%), of management plan in 70 patients (42%), and of tumour resectability in 7 patients (5%). Roughly half the patients ( n = 174,51%) returned for a follow-up, and 154 of the returnees (89%) received treatment, primarily intraarterial therapy ( n = 88, 57%), systemic chemotherapy ( n = 60, 39%), or liver resection ( n = 32, 21%). Enrollment in a clinical trial was proposed to 34 patients (10%), and 21 of the 34 (62%) were accrued. Conclusion Patient assessment by our multidisciplinary liver clinic had a significant impact on management, resulting in alterations to imaging and pathology interpretation, diagnosis, and management plan. The mdlc is an effective and convenient means of delivering expert opinion about the diagnosis and management of liver tumours.
Prediction of Maintenance Dose Required to Attain a Desired Drug Concentration at Steady-state From a Single Determination of Concentration After an Initial Dose

Strong correlations have been reported between drug concentrations at steady-state and a single drug concentration determined sometime after an initial dose for lithium, nortriptyline, Imipramine, desipramine, choramphenicol and theophylline. The mathematical basis of these relationships suggests that a one point method for predicting steady-state drug concentrations and individual dosing requirements should be widely applicable to most drugs and should be valid for patients having a wide range of drug half-lives.
Use of the Aurelia Metamorphosis Test System to detect subtle effects of selected hydrocarbons and petroleum oil

Abstract The Aurelia Metamorphosis Test System was devised to use simple Aurelia polyps as indicator organisms for the detection of subtle effects of petroleum-related hydrocarbons and of Alaskan crude petroleum oil (ACPO) on developmental processes involved in strobilation initiation, differentiation of ephyrae, and genetic modification expressed through cloning. Compounds tested were ACPO, aniline, anthracene, benzanthracene, benzene, benzo[a]pyrene, biphenyl, cresol, naphthalene, perylene, phenol and pyrene. Gross morphology of the ephyrae (patterning, numbers and appearance of structures), statolith and mematocyst numbers, and pulsing behavior were recorded using the light microscope. Selected ephyrae with teratological malformations were studied with the scanning electron microscope and swimming behavior was observed visually. The variety of subtle developmental, behavioral and genetic effects due to marine hydrocarbons detected using the Aurelia Metamorphosis Test System demonstrated that this test system could be used as an early warning system to detect subtle effects of other marine pollutants.
Cognitive Acrobatics in the Construction of Worker–mother Identity

This study uses dialectical theory to explore the interaction of worker identity (perceived financial need and job/career identity) and intensive mothering expectations in mothers’ identity construction. This study is based on extensive interviews with 98 at-home, part-time employed and full-time employed mothers of one or more pre-school children from the Midwestern United States. The narrative analysis reveals that mothers embrace intensive mothering expectations. Because of these cultural expectations, mothers must modify either societal mothering expectations or worker expectations in order to construct an integrated worker–mother identity. We found that while at-home mothers can embrace intensive mothering expectations, employed mothers engage in cognitive acrobatics to manage the tension between employment and the dominant mothering ideology.
Description and comparison of a new cleaning method of diatom frustules for light and electron microscope studies

SUMMARY A general review is made of some of the methods commonly used by phyto-planktologists in preparing and cleaning siliceous diatom frustules for light and electron microscopy. A comparatively simple and safe method using potassium persulphate and oven heating is described. Procedures for rinsing and mounting field samples are also included.
Cretaceous pollen and spore assemblages from Northern Alaska

Abstract The Kuk Inlet and Meade River coals and associated sediments from the Corwin Formation of Alaska contain certain plant microfossils that are similar to those described from upper Lower Cretaceous sediments of Siberia and others that resemble ones that have been recovered from Lower Cretaceous deposits in western Canada. No angiospermous pollen has been encountered in the samples for either the Kuk Inlet or Meade River sections. The pollen grains and spores from the Tuluvak tongue of the Prince Creek Formation, near Umiat, are generally different from the plant microfossils recovered from the other two sections studied. In addition, the Umiat assemblage consists of about 3% angiospermous pollen. Similar percentages of this pollen are present in Siberian sediments of Cenomanian age. Invertebrate macro- and microfossils from marine equivalents of the Tuluvak tongue suggest a Coniacian to Santonian age for the Umiat deposit.
Control of tryptophan oxygenase and formamidase activity in the gerbil

Abstract 1. 1. Mongolian gerbil tryptophan oxygenase activity is essentially undetectable in the untreated animal, is not increased by stress or glucocorticoid administration, but rises significantly following injection of pharmacological doses of tryptophan. 2. 2. Increased apoenzyme conjugation and inhibition by actinomycin D and cycloheximide characterize the tryptophan-induced increase. 3. 3. Gerbil formamidase activity is significant in the untreated animal and the level is not altered by stress, glucocorticoids, or tryptophan. Formamidase activity develops more slowly in the perinatal gerbil than in the young rat. 4. 4. Important differences between the rat and gerbil with regard to these enzymes are emphasized.
Determination of residual stresses in thin sheet titanium aluminide composites

Residual stresses in Ti3Al/SiC composites have been measured using two methods. The compressive residual stresses in the fibers were inferred from measurements of the change in their length when the matrix was entirely removed by etching. The stresses were found to vary substantially from fiber to fiber. The longitudinal and transverse stresses in the matrix were measured by X-ray diffraction. Repeated measurements were made as the outer layer of alloy was removed by electropolishing as far as the first row of fibers. In one composite of lower fiber volume fraction, the matrix stresses were thus found to be approximately uniform throughout the specimen. In a higher volume fraction material, on the other hand, the matrix stresses increased significantly with depth from the outer surface: the longitudinal matrix stresses among the fibers were found to be about 60 pct larger than they were on the specimen surface. The implications of these measurements for processing and reliability of thin sheet titanium aluminide composites are discussed.
Acute internalization of gap junctions in vascular endothelial cells in response to inflammatory mediator-induced G-protein coupled receptor activation

During the inflammatory response, activation of G-protein coupled receptors (GPCRs) by inflammatory mediators rapidly leads to inhibition of gap junction intercellular communication (GJIC); however, the steps that lead to this inhibition are not known. Combining high-resolution fluorescence microscopy and functional assays, we found that activation of the GPCRs PAR-1 and ETA/B by their natural inflammatory mediator agonists, thrombin and endothelin-1, resulted in rapid and acute internalization of gap junctions (GJs) that coincided with the inhibition of GJIC followed by increased vascular permeability. The endocytosis protein clathrin and the scaffold protein ZO-1 appeared to be involved in GJ internalization, and ZO-1 was partially displaced from GJs during the internalization process. These findings demonstrate that GJ internalization is an efficient mechanism for modulating GJIC in inflammatory response.
Stimulus pulse number effect on lingual vibrotactile thresholds

The present pilot investigation was designed to study the effects of pulse number on lingual vibrotactile thresholds when two different contactor sizes were employed. The results suggested that a temporal summation effect occurs with an increase in pulse repetition rate and contactor size. These findings are indicative of a need for future work involving summation measures as a basis for investigating the neurological integrity of the lingual sensory system.
The effect of homonymy on learning correctly articulated versus misarticulated words.

Purpose The goal of the current study was to examine the effect of homonymy (learning a second meaning for a known word form vs. learning a novel meaning and novel word form) and articulation accur...
“… or is the question of being at once the most basic and the most concrete?” On the ambitions and responsibilities of contemporary American philosophy

At its centennial in 2001, the American Philosophical Association bravely proclaimed: “Philosophy Matters.” But does it? It won’t unless it reaches the concreteness of everyday life. To do so was Martin Heidegger’s ambition, and one can read Saul Kripke’s books as an attempt to get mainstream American philosophy beyond its abstractions. At length, Kripke’s efforts, on one reading, failed while Heidegger’s remained incomplete. A theory of commodification can get us closer to the things that matter to us in everyday life.
High prevalence of cobalamin deficiency in elderly outpatients.

Objective: To measure the prevalence of cobalamin (vitamin B12) deficiency in geriatric outpatients as documented by both low serum cobalamin levels and elevations of serum methylmalonic acid and homocysteine and to determine the response to cobalamin treatment. Objective: Prospective study screening elderly subjects for cobalamin deficiency using radiodilution cobalamin assays as well as stable isotope dilution gas chromatography-mass spectrometry methylmalonic acid and homocysteine assays. In patients with serum cobalamin levels ≤300 pg/mL, the response to cobalamin treatment in the group with levels of methylmalonic acid and/or homocysteine >3 standard deviations (SD) above the mean for normals was compared with that of those without such elevations. Setting: Outpatient geriatric clinics at the VA Medical Center and University Health Sciences Center, Denver, CO. Patients: One-hundred and fifty-two consecutive outpatients, ages 65 to 99, were screened. Twenty-nine subjects with serum cobalamin levels ≤300 pg/mL were prospectively evaluated and treated with cobalamin. Main Outcome Measures: Cobalamin, methylmalonic acid, homocysteine, complete blood counts, neurologic examination, and neuropsychological testing. Results: The prevalence of cobalamin deficiency as defined by a serum cobalamin level ≤300 pg/mL and levels of serum methylmalonic acid and/or homocysteine elevated to >3 SD was 14.5% of the screened outpatients. A similar proportion of patients with low normal serum cobalamin levels (between 201 and 300 pg/mL) demonstrated elevated metabolites >3 SD (56%) compared with patients with low serum cobalamin levels (≤200 pg/mL) (62%). Cobalamin therapy caused a marked fall or complete correction of the elevated methylmalonic acid and homocysteine levels in each patient who was treated prospectively. Results for complete blood count, lactate dehydrogenase, bilirubin, baseline neurologic score, and baseline neuropsychologic scores did not differ in the group of patients with elevated metabolites compared with those with normal metabolites. The mean red cell volume fell significantly in the patients with elevated metabolites after 6 months of cobalamin treatment. One patient with elevated metabolites had marked improvement in his neurologic abnormalities after 6 months of cobalamin treatment. Conclusion: There was a high (14.5%) prevalence of cobalamin deficiency as demonstrated by elevations in serum methylmalonic acid and homocysteine in addition to low or low normal serum cobalamin levels in elderly outpatients. The serum cobalamin level was insensitive for screening since similar numbers of patients with low normal serum cobalamin levels of 201–300 pg/mL compared with patients with low cobalamin levels (≤200 pg/mL) had markedly elevated metabolites which fell with cobalamin treatment. Additional studies will be required to define the full clinical benefit from treatment with Cbl in elderly subjects. J Am Geriatr Soc 40:1197–1204, 1992
Transluminal extraction atherectomy for aortosaphenous vein graft stent restenosis.

The optimal strategy to manage in-stent saphenous vein graft (SVG) restenosis has not been studied. We present two cases in which transluminal extraction atherectomy (TEC) was used successfully for the treatment of SVG stent restenosis. TEC atherectomy may provide an alternative to conventional balloon angioplasty for such patients. © 1996 Wiley-Liss, Inc.
On the fire hazard in nuclear power plants

Abstract This work is an investigation of fire as a potential threat to the safety of a nuclear power plant. A qualitative description of ignition mechanisms and factors affecting the growth of fire (detection mechanisms, extinguishing efforts, etc.) is presented and an estimate of the frequency of fires in nuclear power plants is given. Variations of the Browns Ferry fire incident are analyzed probabilistically and the results of different models are compared. Finally, the effect of using water to extinguish the fire on the probability of core damage is studied, based on the Browns Ferry actual sequence of events.
The Fischer 344/NNiaHSd X Brown Norway/BiNia is a Better Model of Sarcopenia than the Fischer 344/NNiaHSd: a Comparative Analysis of Muscle Mass and Contractile Properties in Aging Male Rat Models

Sarcopenia, characterized by profound muscle atrophy and the loss of contractile function, contributes significantly to the development of frailty and functional impairment in older age. Although present in aging humans, rat models have failed to clearly demonstrate a similar degree of this age-associated loss of muscle mass and function. This investigation compared two models of rats raised specifically for aging studies, the Fischer 344/NNiaHSd (F344/N) and the Fischer 344/NNiaHSd X Brown Norway/BiNia (F344/NXBN), and sought to determine which model provides the most accurate representation of human sarcopenia. We found that aging had no effect on F344/N muscle mass or contractile function in the extensor digitorum longus (EDL) and soleus (SOL). Conversely, in the F344/NXBN model, aging was found to decrease EDL and SOL mass and contractile function. These changes were sufficient to satisfy the proposed criteria for the diagnosis of human sarcopenia based upon muscle mass and contractile function. Results indicate that the F344/NXBN provides a better model of the alterations seen in aging human muscle than the F344/N rat model.
Synthesis of barium titanate (BaTiO3) nanofibers via electrospinning

Abstract Barium titanate nanofibers were synthesized by electrospinning utilizing sol–gel precursors. The electrospun polymer–ceramic composite fibers were heat treated to yield perovskite barium titanate fibers after annealing at 750 °C for 1 h. The morphology, microstructure and crystal structure were investigated by SEM, XRD and TEM. Typical fiber diameter was between 80 and 190 nm with fiber lengths exceeding 0.1 mm. This is the first time stand-alone electrospun complex oxide ferroelectric nanofibers are reported. Due to the high electric field of electrospinning (1–2 kV/cm) the electrochemistry is expected to have an impact on the ferroelectric nanofiber properties.
Gaseous Dynamics of the Rabbit Maxillary Sinus

To better understand the mechanisms underlying maxillary sinus function, the gas composition of the sinus antrum in spontaneously breathing and tracheotomized rabbits (n = 17) was compared. The gas composition of samples (n = 117) obtained from rabbit maxillary sinuses was determined by gas chromatography. Results demonstrated significant differences (P < .005) in sinus gas composition between nasal breathing and tracheotomized animals for oxygen (02) and carbon dioxide (CO2). In tracheotomized animals O2 levels decreased while CO2 levels increased markedly to suprasystemic levels. This unexpected finding may be due to reduced sinus blood flow and the effects of nasal versus tracheal respiration. We conclude that the gaseous dynamics and perhaps the function of the maxillary sinus vary under different respiratory conditions. A better understanding of these processes may lead to earlier diagnosis and the development of improved treatments for sinus disease.
Timing and tempo: Exploring the complex association between pubertal development and depression in African American and European American girls

The relative contribution of pubertal timing and tempo to the development of depression has not been tested in a large, representative sample, nor has the interface among pubertal maturation, depression, and race. Participants were a community-based sample of 2,450 girls from the Pittsburgh Girls Study (PGS) who were interviewed annually from ages 9 to 17 years. Pubertal timing and tempo were characterized as a unitary construct and also separately for pubic hair and breast development using child and maternal report. Depression symptoms were assessed annually. African-American females had higher depression symptoms and progressed through puberty earlier, but at a slower tempo than European American girls. Girls with earlier timing had higher levels of depression symptoms at age 10 years. Slower tempo was associated with higher depression symptoms at age 10, and faster tempo was associated with increases in depression from ages 10 to 13. As well, race moderated the associations among timing, tempo, and depression symptoms, and the association between race and depression was partially mediated by pubertal timing and tempo. Pubertal timing and tempo and race contribute to the developmental course of depression from early to late adolescence. The pattern of association varies as a function of the developmental window within which depression is assessed. Thus, repeated measures of depression symptoms and puberty across the span of pubertal development are necessary for exploring the relative importance of dimensions of pubertal development to depression etiology.
Seasonal and Interspecific Nutrient Mitigation Comparisons of Three Emergent Aquatic Macrophytes

ABSTRACT The purpose of this study was to measure both summer and winter nutrient mitigation efficiencies of three aquatic plants found in agricultural drainage ditches in the lower Mississippi River Basin. Mesocosms (1.25 × 0.6 × 0.8 m) were filled with sediment and planted with monocultures of one of three obligate wetland plant species, Typha latifolia, Thalia dealbata, and Sagittaria latifolia, or left nonvegetated to serve as controls. Mesocosms were amended with nitrate, ammonium, and phosphate over a 4-h hydraulic retention time, followed by an 8-h flushing with nonamended water to assess residual nutrient leaching in both summer and winter exposures. Significant interactions between vegetation type and season were noted for both nitrate and total inorganic phosphorus concentrations and loads. Future research will focus on altering hydraulic retention time for improved efficiency, as well as the specific contribution of microbial activity to nutrient mitigation.
Fuzzy queries in multimedia database systems

There are essential differences between multimedia databases (which may contain complicated objects, such as images), and traditional databases. These differences lead to interesting new issues, and in particular cause us to consider new typos of queries. Wr example, in a multimedia database it is reasonable and natural to ask for images that are somehow “similar to” some fixed image. Furthermore, there are different ways of obtaining and accessing information in a multimedia database than information in a traditional database. For example, in a multimedia database, it might be reasonable to have a query that asks for, say, the top 10 images that are similar to a fixed image. This is in contrast to a rolationnl database, where the answer to a query is simply a set, In this paper, we survey some new issues that arise for multimedia queries, with a particular focus on recent research by the author, developed in the context of the Garlic system at the IBM Almaden Research Center.
A knowledge and data base for software systems

The authors discuss a knowledge/data centered architecture for CASE (computer-aided software engineering) environments that has at its heart a knowledge and database management system (repository) on which all CASE tools rely for knowledge and data services. The repository has three entity kinds: objects, procedures, and rules. Data reside in the objects while knowledge resides in the procedures, rules, and special fields in the objects. The authors discuss why a third generation database management system, which incorporates data, object, and knowledge services, is a good choice for the knowledge manager. They use an object-oriented model of software systems to analyze the storage requirements of program documents in the repository and show how the procedures and rules can be used to efficiently maintain multiple software document representations. It is then shown how the repository can effectively support a software reuse library and reuse processes throughout the life-cycle. >