cssi/SciSciGPT-SciSciNet huggingface dataset:
Free radical formation by antitumor quinones

Quinones are among the most frequently used drugs to treat human cancer. All of the antitumor quinones can undergo reversible enzymatic reduction and oxidation, and form semiquinone and oxygen radicals. For several antitumor quinones enzymatic reduction also leads to formation of alkylating species but whether this involves reduction to the semiquinone or the hydroquinone is not always clear. The antitumor activity of quinones is frequently linked to DNA damage caused by alkylating species or oxygen radicals. Some other effects of the antitumor quinones, such as cardiotoxicity and skin toxicity, may also be related to oxygen radical formation. The evidence for a relationship between radical formation and the biological activity of the antitumor quinones is evaluated.
Advances in scientific visualization

This paper discusses scientific visualization of scalar and vector fields, particularly relating to clouds and climate modeling. One cloud rendering method applies a 3-D texture to cloudiness contour surfaces, to simulate a view from outer space. The texture is advected by the wind flow, so that it follows the cloud motion. Another technique simulates multiple scattering of incident light from the sun and sky. This paper also presents a simulation of the microscopic cross-bridge motion which powers muscle contraction. It was rendered by ray-tracing contour surfaces of summed Gaussian ellipsoids approximating the actin and myosin protein shapes.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Confocal imaging of the retrograde tracer fluoro-gold using a non-ultraviolet laser

Until now, Fluoro-gold confocal imaging has been problematic because it requires an ultraviolet laser. We describe here a practical method to visualize Fluoro-gold in a confocal laser scanning microscope without an ultraviolet laser through an immunofluorescence procedure using antibodies against Fluoro-gold.
Through the prism of the metaphor: A reflection of the actuality of Kant's philosophy

This essay examines the significance of Kant's transcendental philosophy by focusing on the central metaphors used in his works. The four metaphors singled out here are those of (a) the Copernican turn, (b) the land of truth and the ocean of illusion, (c) the starry heavens and the moral law, and (d) of perpetual peace. The author emphasizes the strong and the weak points of Kant's philosophy that these metaphors reveals, and argues that these central metaphors work together and point toward the two essential concerns of Kant's entire philosophical opus: (1) an active role of the creative subject in all forms of human experience, and (2) the boundaries of the subject's creativity. Further reflection should not only reveal some other metaphors and their role in Kant's philosophy, but also clarify how he himself understand the nature of metaphors: Are metaphors the expression of our creativity, or of the limitations of our creativity?.
Mapping Surface Currents and Waves with Interferometric Synthetic Aperture Radar in Coastal Waters: Observations of Wave Breaking in Swell-Dominant Conditions*

Airborne and spaceborne interferometric synthetic aperture radars (InSARs) produce surface velocity measurements at very high spatial resolutions over a large area. The data allow construction of the velocity strain field for highlighting ocean surface processes such as wave breaking and rip currents. Also, coherence between signals from two interferometric channels is a descriptor of the correlation condition of the surface roughness that scatters back the radar signals and it is an indication of the ocean surface turbulence. Wave breaking is a major turbulence source causing surface roughness decorrelation, thus the coherence parameter serves as an independent means for detecting wave breaking. The results of breaking detection using roughness decorrelation and critical local acceleration are comparable. In this paper, the breaking fraction in swell-dominant mixed seas along a cross-shore transect is compared with several steepness parameters characterizing different length scales of surface waves. The highest correlation coefficient (from 0.90 to 0.99) is between the breaking fraction and windsea mean square slope contributed primarily by short waves. This result reinforces the previous field observations showing that the length scales of breaking waves are much shorter than the energetic components near the spectral peak, although dominant waves and the associated wave group modulation are important in triggering the breaking process. The large spatial coverage of airborne or spaceborne operation further offers the opportunity to investigate evolution of the surface wave spectrum in high spatial (subkilometer) resolution. This capability is very useful for monitoring the coastal wave and current environment.
Hydrothermal synthesis and characterization of an unusual polyoxovanadium borate cluster: structure of Rb4[(VO)6{ {B10O16(OH)6} }2] · 0.5H2O

Abstract The hydrothermal reaction of RbVO3, (NH4)2B4O7 · 4H2O, ethylenediamine (en), and H2O in a mole ratio of 1:8:2:135 heated at 170°C for 5 days produces pale green crystals of the novel polyoxovanadium borate cluster compound Rb4[(VO)6{B10O16(OH)6}2] · 0.5H2O (1) which contains [V6B20O38(OH)12]4− clusters, each cluster comprising a nearly hexagonal ring of six trans-edge-sharing VO5 square pyramids capped on each side by a B10O16(OH)68− triangle. The [V6B20O38(OH)12]4− clusters are separated in the solid state by Rb+ cations. Magnetic susceptibility and valence sum calculations indicate that all six of the vanadium atoms in the cluster are in the 4+ oxidation state.
Annealing and structure studies on Tl-2223 and Tl-1223 crystals

Abstract Single crystals with nominal stoichiometry Tl 2 Ca 2 Ba 2 Cu 3 O 10 (Tl-2223) and TlCa 2 Ba 2 Cu 3 O 9 (Tl-1223) have been annealed in flowing oxygen or nitrogen and the complete crystal structure determined by least-squares refinement of Mo Kα x-ray diffraction data. Small atomic displacements are found after the anneals that are consistent with a model in which small amounts of Tl 1+ present in the TlO layer are subsequently reversibly oxidized/reduced during mild oxygen/nitrogen anneals to Tl 3+ . Despite substantial changes in oxygen content in the TlO layers with annealing, Meissner data show very modest shifts in the superconducting transition temperature, suggesting little change in the carrier concentration in the CuO 2 planes.
The anatomy of protein beta-sheet topology.

Here, we present a systematic analysis of the open-faced beta-sheet topologies in a set of non-redundant protein domain structures; in particular, we focus on the topological diversity of four-stranded beta-sheet motifs. Of the 96 topologies that are possible for a four-stranded beta-sheet, 42 were identified in known protein structures. Of these, four account for 50% of the structures that we have studied. Two sets of the topologies that were not observed may represent the section of the topological space that is not readily accessible to proteins on either thermodynamic or kinetic grounds. The first set contains topologies with alternating parallel and antiparallel beta-ladders. Their rare occurrence reflects the expectation that it is energetically unfavorable to match different hydrogen bonding patterns. The polypeptide chains in the second set of topologies go through convoluted paths and are expected to experience great kinetic frustrations during the folding processes. A knowledge of the potential causes for the topological preference of small beta-sheets also helps us to understand the topological properties of larger beta-sheet structures which frequently contain four-stranded motifs. The notion that protein topologies can only be taken from a confined and discrete space has important implications for structural genomics.
Large amplitude collective motion

Abstract There are many phenomena in nuclear physics that depend on large changes of the nuclear shape. This includes spectroscopic properties, hindered transitions, and particle decay processes. Here I survey these properties and also give a brief summary of the microscopic theories for shape dynamics, emphasizing the key role of the pairing interaction. A simplified model of the dynamics, the hopping model, treats only the pairing, but reproduces more sophisticated generator coordinate calculations and has been been extrensively applied to the different physical phenomena.
A molecular theory of cartilage viscoelasticity

Recent work on the subject of cartilage mechanics has begun to focus on the relationship between the microscopic structure of cartilage and its macroscopic mechanical properties (Bader et al., Biochem. Biophys. Acta, 1116 (1992) 147-154; Buschmann, PhD Thesis, Massachusetts Institute of Technology, 1992; Kovach, Biophys. Chem., 53 (1995) 181-187; Lai et al., J. Biochem. Eng., 113 (1991) 245-248; Armstrong and Mow, J. Bone Jt. Surg., 64A (1982) 88; Jackson and James, Biorheology, 19 (1982) 317-330). This paper reviews recent theoretical developments and presents a comprehensive explanation of the viscoelastic properties of cartilage in terms of molecular structure. In doing this, a closed form hybrid solution to the non-linear, cylindrical Poisson-Boltzmann equation is developed to describe the charge-dependent component of the equilibrium elasticity arising from polysaccharide charge (Benham, J. Chem. Phys., 79 (4) (1983) 1969-1973; Einevoll and Hemmer, J. Phys. Chem., 89 (1) (1988) 474-484; Fixman, J. Chem. Phys., 70 (11) (1979) 4995-5001; Ramanathan and Woodburg, J. Chem. Phys., 82 (3) (1985) 1482-1491; Wennerstrom et al., J. Chem. Phys., 76 (9) (1982) 4665-4670). This solution agrees with numerical solutions found in the literature (Buschmann, PhD Thesis, Massachusetts Institute of Technology, 1992). The charge-independent, entropic contribution to the equilibrium elasticity is explained in a manner similar to that recently presented for concentrated proteoglycan solution (Kovach, Biophys. Chem., 53 (1995) 181-187). This approach exploits a lattice model of the solution, subject to a Bragg-Williams type approximation to derive the volume dependence of polysaccharide configuration entropy (Flory, Principles of Polymer Chemistry, Cornell University Press, Ithaca, NY, 1953; Huggins, Some properties of Solutions of Long-chain Compounds, 1941, pp. 151-157; Stanley, Introduction to Phase Transitions and Critical Phenomena, Oxford University Press, Oxford, 1971). Together, these two contributions accurately reproduce the experimentally determined osmotic pressure of cartilage as previously determined by Maroudas (Maroudas and Bannon, Biorheology, 18 (1981) 619-632). The time-dependent, or creep, phenomena which cartilage exhibits when subject to mechanical load is explained in terms of frictional drag on the polysaccharide chain monomers in terms of a Kirkwood-Riseman type model (Kirkwood and Riseman, J. Chem. Phys., 16 (6) (1948) 573-579). This approach is shown to accurately predict the hydraulic permeability of cartilage as previously determined by Maroudas (Madouras, Ann. Rheum. Dis., 34 (suppl. 3) (1975) 77). By use of a quasi-static approximation (neglecting inertial effects) the time-dependent response to a uniform compressive force is determined and also found to be in good agreement with experimental values from the literature.
Reputation from nested activities

Principals usually try to elicit the quality and behavior of agents from their performance. While sometimes success or failure in production does not provide accurate information about the agents, there may be activities not directly related to production that constitute a more precise signal. I show that, when agents face reputation concerns, introducing these activities after a success improves efficiency, while introducing them after a failure reduces efficiency. Hence, nesting activities in the right way may offer a cheap toolbox to provide incentives. As an illustration, I consider a model where reputation concerns drive the hiring decisions of managers in a firm and I show how scapegoating, an activity “nested” after failures in production, generates inefficiencies. While hiring efficient workers increases the probability of success, hiring less efficient workers provides a buffer against reputation loses from failures, since managers can blame them more easily.
Evaluating the evolution of process specific degradation signatures around impact craters

The pristine morphologies created during an impact event comprise a template for constraining how various environmental parameters influence the mechanics of crater formation. Identification of pristine morphologies used in defining and/or evaluating models of crater formation can be complicated or precluded, however, by the effects of post-formation degradation. Field and/or remote examination of simple, unglaciated impact craters on the Earth (e.g., Meteor Crater, Arizona, and Roter Kamm crater, Namibia) can yield results that help to define characteristic degradation signatures for use in placing first-order constraints on the number and intensity of processes that have been active. In turn, the presence of a suite of these degradation signatures can be used to define the amount and style of crater degradation that has taken place, thereby providing a tool for possible distinction between pristine versus secondary, post-formation characteristics.
Effects of mecamylamine, nicotine, atropine and physostigmine on the phencyclidine-induced behavioral toxicity.

Abstract Phencyclidine (PCP) has multifaceted actions on the cholinergic functions, including interaction with the central and peripheral cholinergic receptors. Therefore, to evaluate the possible involvement of the nicotinic and muscarinic acetylcholine (ACh) receptors during the behavioral toxicity of PCP, influence of various cholinergic modifiers on the PCP-induced behavioral effects in male Swiss mice was studied. PCP-induced (45 μmol/kg, IP) behavioral toxicity (circular movements, side-to-side head movements, and hyperactivity leading to convulsions) was blocked by pretreating the animals with secondary- or tertiaryamino-cholinergic modifiers, mecamylamine (ME; 14.9 and 29.9 μmol/kg), nicotine (NI; 12.3 and 30.8 μmol/kg) and physostigmine (PH; 0.16 and 0.31 μmol/kg). NI at 1.5 μmol/kg significantly potentiated the PCP-induced convulsions. Atropine (AT; 14.4 and 28.8 μmol/kg) pretreatments shortened the onset of circular movements. The locomotor activity of PCP (16.4 μmol/kg) was blocked by ME, NI, and PH. AT at 7.2 μmol/kg significantly potentiated the PCP-locomotion by 62%. These observations indicated that the behavioral actions of PCP, at least in part, are mediated by the central nicotinic and muscarinic ACh receptors. The involvement of cholinergic receptors in conjunction with the dopaminergic actions of PCP during these behaviors also has been discussed.
Environmental pollutant Cd2+ biphasically and differentially regulates myosin light chain kinase and phospholipid/Ca2+-dependent protein kinase

Cd2+ was found to mimic effectively, potentiate and antagonize the stimulatory action of Ca2+ on myosin light chain kinase (MLCK) and phospholipid-sensitive Ca2+-dependent protein kinase (PL-Ca-PK, or protein kinase C). PL-Ca-PK, however, was slightly less sensitive to Cd2+ regulation than was MLCK. Cd2+ also biphasically regulates (i.e., stimulation followed by inhibition) phosphorylation, in the homogenates of the rat caudal artery, of myosin light chain and other endogenous proteins catalyzed by MLCK and PL-Ca-PK. The activation by Cd2+ of MLCK was inhibited by anticalmodulins (e.g., R-24571), whereas the inhibition by a higher Cd2+ concentration of MLCK and PL-Ca-PK was reversed by thiol agents (e.g., cysteine). The present findings may provide one mechanism underlying the vascular toxicity of Cd2+, a major environmental pollutant.
An empirical study of moral reasoning among managers

Current research in moral development suggests that there are two distinct modes of moral reasoning, one based on a morality of justice, the other based on a morality of care. The research presented here examines the kinds of moral reasoning used by managers in work-related conflicts. Twenty men and twenty women were randomly selected from the population of first level managers in a Fortune 100 industrial corporation. In open-ended interviews each participant was asked to describe a situation of moral conflict in her or his work life. The results indicated a clearly preferred mode of moral reasoning among the participants who described moral conflicts. Nearly all of these predominated with a justice orientation. These findings suggest that a correlation between gender and preferred mode may be context specific.
Convex relaxations of chance constrained optimization problems

In this paper we develop convex relaxations of chance constrained optimization problems in order to obtain lower bounds on the optimal value. Unlike existing statistical lower bounding techniques, our approach is designed to provide deterministic lower bounds. We show that a version of the proposed scheme leads to a tractable convex relaxation when the chance constraint function is affine with respect to the underlying random vector and the random vector has independent components. We also propose an iterative improvement scheme for refining the bounds.
Fixed-diameter polyethylene cuffs applied to the rat sciatic nerve induce a painful neuropathy: ultrastructural morphometric analysis of axonal alterations

Abstract Polyethylene cuffs of varying inner diameters were applied to the rat sciatic or sural nerve with the aim of inducing a standardized nerve injury, as assessed by morphometric analyses of fiber-size spectrum alterations, associated with behavioral manifestations of neuropathic pain. The temporal sequence of axonal degeneration and regeneration was examined in parallel with behavioral analyses of pain initiation and recovery over a 6-week postoperative (PO) period. Cuffs of 0.028–0.030″ inner diameter loosely enclosed sciatic nerves of young rats and elicited relatively uniform axonal degeneration and ‘pain’. Large myelinated axons underwent an early and sustained numerical depletion. Both the thinly myelinated and unmyelinated axon populations were initially diminished, but later rose to levels significantly greater than control values, likely the result of: (1) demyelination, (2) early stages of remyelination, (3) regenerative sprouting, and/or (4) collateral sprouting of undamaged unmyelinated axons. Pathological alterations of the injured nerve included edematous swelling, hypertrophy of the perineurial sheath, infiltration of fibroblasts and collagen into the intraneurial compartment, increasing interaxonal space and decreasing order and density of axonal packing. Animals displayed maximal pain-related behaviors, including gait and postural asymmetries and hypersensitivity to mechanical compression and cold, during the 2nd week PO and had largely recovered by ∼ 4 weeks PO. Consistent behavioral manifestations of pain were achieved over a wide range of fiber spectrum alteration; however, with the largest cuffs or ‘bracelets’ used in this study, a substantial axonal fiber spectrum change was produced without inducing pain-related behavior, suggesting that decrement in the number of myelinated axons was not always sufficient to elicit pain. Similar morphometric and pathological results were achieved with sural neuropathy after 0.010″ ID cuffs and 14 days PO survival. Considering the lack of correlation between axonal alterations and pain, modification in the local intraneurial microenvironment at the site of injury may be a key component of peripheral pain mechanisms; these include changes in the biochemical milieu, increased intraneurial pressure, and altered nociceptor sensitivity or impulse propagation in the relatively intact unmyelinated axon population.
Advanced IX projection photolithography

Pattern techniques in the semiconductor industry are driven by the need to improve cost/performance per bit. The key to reducing cost per bit and improving performance is increased density. Tighter photolithography ground rules (smaller images with reduced line width and registration tolerances) are primary sources of increased density. Enhanced ground rules coupled with larger wafers are certain to form the basis for the next generation of VLSI chips. The trend toward tighter ground rules and larger wafers is causing many semiconductor manufacturers to migrate away from IX projection tools, the workhorses of present-day production lines, to step and repeat exposure tools. The higher numerical aperture of step and repeat tools, coupled with chip-by-chip focus, guarantees improved resolution compared to today’s IX projection tools. The price paid for increased numerical aperture is reduced field size and, subsequently, reduced throughput and higher exposure cost per wafer. Ideally, it would be preferable to improve the resolution of the IX projection tool/process to make it competitive with the step and repeat tool, while maintaining the high throughput of IX systems. Effective use of shorter exposure (< 350 nm) wavelengths in IX systems is the key to extending resolution capability.
Let's not throw the baby out with the bathwater: The catharsis hypothesis revisited1

Boys between the ages of 9 and 10 participated in one of three experimental activities. One involved movement and aggression, the second movement devoid of aggression, and the third minimal movement of a nonaggressive nature. Aggressive fantasy decreased in the aggressive movement and minimal movement groups but increased in the nonaggressive movement group. The results are consistent with a cathartic view of the functional relationship between aggressive behavior and aggressive fantasy when the effects of movement and completion of an aggressive response are considered. This study supports the notion that the enactment of an aggressive goal response is essential to the occurrence of a cathartic effect and points up the importance of controlling for movement in investigations of the relationship between aggressive fantasy and aggressive behavior. An additional, exploratory investigation of daydreaming suggests that children who are high in aggressive fantasy are likely to daydream more frequently than children low in aggressive fantasy.
Sphingolipids as Bioactive Regulators of Thrombin Generation

Sphingolipids contribute to modulation of two opposing cell processes, cell growth and apoptotic cell death; ceramide and sphingosine promote the latter and sphingosine-1-phosphate triggers the former. Thrombin, a pro-inflammatory protease that is regulated by the blood coagulation cascade, exerts similar effects depending on cell type. Here we report a new mechanism for cross-talk between sphingolipid metabolism and thrombin generation. Sphingosine and sphinganine, but not ceramide or sphingosine-1-phosphate, down-regulated thrombin generation on platelet surfaces (IC(50) = 2.4 and 1.4 microm for sphingosine and sphinganine, respectively) as well as in whole plasma clotting assays. Thrombin generation was also inhibited by glucosylsphingosine, lysosphingomyelin, phytosphingosine, and primary alkylamines with >10 carbons. Acylation of the amino group ablated anticoagulant activities. Factor Va was required for the anticoagulant property of sphingosine because prothrombin activation was inhibited by sphingosine, sphinganine, and stearylamine in the presence but not in the absence of factor Va. Sphingosine did not inhibit thrombin generation when Gla-domainless factor Xa was used in prothrombinase assays, whereas sphingosine inhibited activation of Gla-domainless prothrombin by factor Xa/factor Va in the absence of phospholipids (IC(50) = 0.49 microm). Fluorescence spectroscopy studies showed that sphingosine binds to fluorescein-labeled factor Xa and that this interaction required the Gla domain. These results imply that sphingosine disrupts interactions between factor Va and the Gla domain of factor Xa in the prothrombinase complex. Thus, certain sphingolipids may be bioactive lipid mediators of thrombin generation such that certain sphingolipid metabolites may modulate proteases that affect cell growth and death, blood coagulation, and inflammation.
Extending Greene's theorem to directed graphs

Abstract The purpose of this note is to prove a theorem on acyclic digraphs, conjectured by Linial ( J. Combin. Theory Ser. A , 30 (1981), 331–334), which includes Greene's theorem ( J. Combin. Theory Ser. A , 20 (1976), 69–79) on decompositions of a partially ordered set into antichains.
Genetic utility of natural history museum specimens: endangered fairy shrimp (Branchiopoda, Anostraca)

We examined the potential utility of museum specimens as a source for genetic analysis of fairy shrimp. Because of loss of their vernal pool habitat, some fairy shrimp (including Branchinecta sandiegonensis and Branchinecta lynchi) are listed as threatened or endangered in Southern California by the United States Fish and Wildlife Service. Management of those species requires extensive population genetics studies and the resolution of important genetic complexity (e.g. possible hybridization between endangered and non-endangered species). Regulations mandating deposition of specimens of listed species have resulted in thousands of specimens accessioned into the Natural History Museum of Los Angeles County that have been preserved in a variety of solutions. We subsampled those specimens, as well as other Anostraca with known collection and preservation histories, to test their potential for genetic analysis by attempting DNA extraction and amplification for mt16SrDNA. Fixation and preservation in not denatured ethanol had a far greater sequencing success rate than other (and unknown) fixatives and preservatives. To maximize scientific value we recommend field preservation in 95% not denatured ethanol (or, if pure ethanol is unavailable, high-proof drinking spirits, e.g. Everclear™, or 151 proof white rum), followed by storage in 95% not denatured ethanol.
Membrane lipid rafts, master regulators of hematopoietic stem cell retention in bone marrow and their trafficking

Cell outer membranes contain glycosphingolipids and protein receptors, which are integrated into glycoprotein microdomains, known as lipid rafts, which float freely in the membrane bilayer. These structures have an important role in assembling signaling molecules (e.g., Rac-1, RhoH and Lyn) together with surface receptors, such as the CXCR4 receptor for α-chemokine stromal-derived factor-1, the α4β1-integrin receptor (VLA-4) for vascular cell adhesion molecule-1 and the c-kit receptor for stem cell factor, which together regulate several aspects of hematopoietic stem/progenitor cell (HSPC) biology. Here, we discuss the role of lipid raft integrity in the retention and quiescence of normal HSPCs in bone marrow niches as well as in regulating HSPC mobilization and homing. We will also discuss the pathological consequences of the defect in lipid raft integrity seen in paroxysmal nocturnal hemoglobinuria and the emerging evidence for the involvement of lipid rafts in hematological malignancies.
Exploit the scale of big data for data privacy: An efficient scheme based on distance-preserving artificial noise and secret matrix transform

In this paper we show that the extensive results in blind/non-blind channel identification developed within the community of signal processing in communications can play an important role in guaranteeing big data privacy. It is widely believed that the sheer scale of big data makes most conventional data privacy techniques ineffective for big data. In contrast to this pessimistic common belief, we propose a scheme that exploits the sheer scale to guarantee privacy. This scheme uses jointly artificial noise and secret matrix transform to scramble the source data. Desirable data utility can be supported because the noise and the transform preserve some important geometric properties of the source data. With a comprehensive privacy analysis, we use the blind/non-blind channel identification theories to show that the secret transform matrix and the source data can not be estimated from the scrambled data. The artificial noise and the sheer scale of big data are critical for this purpose. Simulations of collaborative filtering are conducted to demonstrate the proposed scheme.
N1-(substituted) pantothenamides, antimetabolites of pantothenic acid

Abstract A series of analogs with the general structure N 1 -(substituted) pantothenamide has been prepared and studied in several microbiological systems. Certain of these derivatives were inhibitory to growth of lactic acid bacteria at concentrations as low as 6 μg/ml and to Escherichia coli at levels as low as 0.6 μg/ml. In Lactobacillus arabinosus and Pediococcus cerevisiae the analogs were competitively reversed by pantothenic acid with inhibition indices between 30 and 300. Inhibition of growth by the analogs in E. coli is of particular interest since previous potential pantothenic acid antimetabolites have been relatively inactive for this microorganism.
The skin penetration cell: a design update

Abstract Existing in vitro skin penetration cells based on the Franz cell were assessed for: (a) uniformity of stirring; and (b) receptor phase volume. Based on the results of these experiments two flow-through in vitro penetration cells were designed to meet the following specifications: (a) small receptor phase volumes; (b) instantaneous stirring; (c) variable skin surface areas; and (d) compatibility with current stirring apparatus.
Structures of Lithiated Lysine and Structural Analogues in the Gas Phase: Effects of Water and Proton Affinity on Zwitterionic Stability†

The structures of lithiated lysine, ornithine, and related molecules, both with and without a water molecule, are investigated using both density functional theory and blackbody infrared radiative dissociation experiments. The lowest-energy structure of lithiated lysine without a water molecule is nonzwitterionic; the metal ion interacts with both nitrogen atoms and the carbonyl oxygen. Structures in which lysine is zwitterionic are higher in energy by more than 29 kJ/mol. In contrast, the singly hydrated clusters with the zwitterionic and nonzwitterionic forms of lysine are more similar in energy, with the nonzwitterionic form more stable by only approximately 7 kJ/mol. Thus, a single water molecule can substantially stabilize the zwitterionic form of an amino acid. Analogous molecules that have methyl groups attached to either the N-terminus (NMeLys) or the side-chain amine (Lys(Me)) have proton affinities greater than that of lysine. In the lithiated clusters with a water molecule attached, the zwitterionic forms of NMeLys and Lys(Me) are calculated to be approximately 4 and approximately 11 kJ/mol more stable than the nonzwitterionic forms, respectively. Calculations of the potential-energy pathway for interconversion between the different forms of lysine in the lithiated complex indicate multiple stable intermediates with an overall barrier height of approximately 83 kJ/mol between the lowest-energy nonzwitterionic form and the most accessible zwitterionic form. Experimentally determined binding energies of water are similar for all these complexes and range from 57 to 64 kJ/mol. These results suggest that loss of a water molecule from the lysine complexes is both energetically and entropically favored compared to interconversion between the nonzwitterionic and zwitterionic structures. Comparisons to calculated binding energies of water to the various structures show that the experimental results are most consistent with the nonzwitterionic forms.
Weak convergence of bounded influence regression estimates with applications to repeated significance testing

Abstract We obtained weak convergence results for bounded influence regression M-estimates and apply the results to sequential clinical trials, with special reference to repeated significance tests in the two-sample problem with covariates.
Effect of Further Processing and Storage of Mechanically Deboned Chicken on Proximate Composition, Thiamin, Riboflavin and TBA Values

Mechanically deboned chicken (MDC), and its further processed products, frankfurters (FK) and bolognas (BG), were evaluated for proximate composition, thiamin, riboflavin and TBA values following processing and storage. Vitamin concentrations were found stable in MDC stored at 2°C for 2 days or at – 18°C for 180 days. The processing of FK and BG reduced the vitamin levels by0–12% on a dry weight basis. Storage of FK and BG for 42 days at 2°C or 180 days at – 18°C had no measurable effect on vitamin content. TBA values were generally low except their increases were significant in the salted MDC held at – 18°C. Proximate composition varied among products but was not affected by storage time and temperature.
Insulin Stimulates Phosphatidylinositol 3‐Kinase Activity in Rat Neuronal Primary Cultures

We investigated the effect of insulin on phosphatidylinositol (PtdIns) 3-kinase (PtdIns 3-kinase) activity in neuronal cultures to determine if this enzyme is involved with the neurotrophic actions of insulin. Insulin caused a concentration-dependent increase in PtdIns 3-kinase activity in anti-phosphotyrosine immunoprecipitates. The kinase activity was able to phosphorylate PtdIns, PtdIns 4-phosphate, and PtdIns 4,5-bisphosphate. In intact neurons, a 10-min 1 mM insulin treatment in the presence of [32P]orthophosphate increased the levels of both 3-[32P]PtdIns phosphate and 3,4-[32P]PtdIns bisphosphate by 55 and 193%, respectively. This increase was associated with an increase in neurite outgrowth mediated by insulin. Our results indicate that insulin treatment of neuronal cells in primary culture increases PtdIns 3-kinase activity and the formation of the unique D-3-phosphorylated phosphoinositides, suggesting that growth factor-mediated neuronal growth may include the formation of novel phosphoinositide 3-phosphate phospholipids.
Effects of genetic diabetes and zinc nutriture on in vivo cell-mediated immunity in the mouse

ABSTRACF To examine whether an abnormal zinc status contributes significantly to the impaired in vivo cell-mediated immunity of the genetically diabetic C57BL/KsJ db/db mouse, we measured specific cytotoxicity of spleen cells from db/db and heterozygous (db/m) and homozygous (m/m) control mice fed either zinc-deficient (2 mg/kg) or zinc-adequate (20 mg/kg) semipurified diets. Low serum and femur zinc concentrations were seen after 4 wk in all mice fed the zinc-deficient diet, but impaired cytotoxicity was not seen until later in control mice fed that diet. In contrast, db/db mice fed zinc-adequate diets bad diminished spleen weights and markedly impaired cytotoxicity by 4 wk. These mice had normal serum and only mildly decreased femur zinc concentrations. We, therefore, found no evidence to suggest that the mildly altered zinc status of db/db mice fed zincadequate diets is a major factor contributing to their markedly impairedin vivo cell-mediated immunity. Am J C/in Nuir 1986;43:263-27 1.
Measuring And Changing The Values Of Accounting Students

Although prior research has consistently shown that personal values influence behavior, limited research and curricular activity have been conducted with respect to the role of personal values in accounting. This purpose of this paper is to propose a methodology that accounting programs can use to measure the personal values of students. Specifically, we examine the Muser and Orke Typology for measuring personal values. Using students from a comprehensive, private university in the Midwest, we discuss the administration of the instrument and the evaluation of the results. The paper concludes with a detailed description of how accounting programs can apply this methodology to change students’ values toward a desired goal.
Diffusion‐controlled reaction. VI. Radiation graft polymerization of 4‐vinylpyridine to polyethylene

The radiation-initiated graft polymerization of 4-vinylpyridine to high-density polyethylene was studied over a wide range of reaction conditions of radiation intensity I, monomer concentration M1, and polymer film thickness L. The conditions included both diffusion-free and diffusion-controlled graft polymerizations. The results corroborate our previous theoretical predictions on the effect of I, M1, and L on the experimental grafting rate. The grafting rate is inverse first order in L for diffusion-controlled reaction and independent of L for diffusion-free reaction. The dependence of grafting rate on radiation intensity decreases from 1/2 to 1/4 order for diffusion-controlled reaction. Diffusion control results in a decrease in the dependence of rate on monomer concentration. The observed decrease is somewhat greater than theoretically predicted.
Do teachers think that methods are dead

This paper examines Block's (2001) claim that whereas the notion of method no longer plays a significant role in the thinking of applied linguists, it still plays a vital role in the thinking of teachers. In order to assess Block's claim, four sources of data on teachers' beliefs were examined—two direct sources of data: (1) interviews with questions directly addressing teachers' opinions on the concept of method and (2) discussion board postings on the topic of post-method, and two indirect sources: (3) language learning/teaching autobiographies and (4) teaching journals. The evidence from the data suggests that teacher interest in methods is determined by how far methods provide options in dealing with particular teaching contexts. Rather than playing a vital role in teacher thinking, teacher attitude towards methods is highly pragmatic. In the light of this evidence, implications for teacher education are considered.
Iterative control of dynamics-coupling-caused errors in piezoscanners during high-speed AFM operation

This paper addresses the compensation of the dynamics-coupling effect in piezoscanners used for positioning in atomic force microscopes (AFMs). Piezoscanners are used to position the AFM probe, relative to the sample, both parallel to the sample surface (x and y axes) and perpendicular to the sample surface (z axis). In this paper, we show that dynamics-coupling from the scan axes (x and y axes) to the perpendicular z axis can generate significant positioning errors during high-speed AFM operation, i.e., when the sample is scanned at high speed. We use an inversion-based iterative control approach to compensate for this dynamics-coupling effect. Convergence of the iterative approach is investigated and experimental results show that the dynamics-coupling-caused error can be reduced, close to the noise level, using the proposed approach. Thus, the main contribution of this paper is the development of an approach to substantially reduce the dynamics-coupling-caused error and thereby, to enable high-speed AFM operation.
Three-Dimensional Evaluation of Aortic Valve Annular Shape in Children With Bicuspid Aortic Valves and/or Aortic Coarctation Compared With Controls.

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality, occurring in 1% to 2% of the general population. Adults with degenerative aortic valve (AV) disease have been shown to have an elliptical shaped AV annulus. The goal of this study was to investigate the shape of the aortic annulus in children with BAV, coarctation of the aorta (CoA) with or without BAV, and normal controls with trileaflet AVs using 3-dimensional echocardiography (3DE). We reviewed echocardiograms of children with isolated BAV (n = 40), CoA (n = 26), and controls (n = 40) that included 3DE of the AV. Eccentricity index (EI) was defined as the ratio between the smaller and larger annular dimension. ΔD was defined as the difference between the larger and smaller annular dimension. Patients with BAV had an eccentric AV annulus compared with controls (BAV EI 0.85 ± 0.05 and control EI 0.96 ± 0.03; p <0.001). Subjects with CoA also had a more eccentric annulus than controls regardless of AV morphology (CoA 0.84 ± 0.06; p <0.001). EI was not associated with somatic growth parameters or gender. Among all patients with BAV, AV dysfunction was associated with fusion of the right and noncoronary (R-N) cusps (p <0.001), but there was no association between valve dysfunction and EI. ΔD was higher in both the BAV and CoA groups compared with the control group (BAV 3.4 ± 1.9 mm, CoA 2.8 ± 1.8 mm, and control 0.6 ± 0.4 mm; p <0.001 each). Although there was no significant correlation of ΔD with age in the control group during childhood, ΔD increased with age in the BAV and CoA groups. In conclusion, children with BAV and/or CoA have an elliptical shaped AV annulus by 3DE, which is independent of age, gender, or body surface area. AV annular eccentricity may lead to inaccurate measurement of AV annular size if measured by 2DE alone. Considering AV annular eccentricity when balloon sizing the annulus before valvuloplasty may help improve interventional results in some patients.
The association of neighborhood characteristics with sleep duration and daytime sleepiness.

Abstract Background Neighborhood characteristics have been linked to health outcomes. Various mechanisms link neighborhoods and health outcomes; sleep patterns may be 1 contributor; however, little is known about the social determinants of disordered sleep. We examined the association of neighborhood characteristics with sleep duration and daytime sleepiness. Methods Participants (n = 801) enrolled as pairs (55 without pair), from 10 churches in the Stroke Health and Risk Education project; 760 were included for analysis (41 withdrew). Sleep duration (hours of sleep at night) and daytime sleepiness (adaptation of Berlin questionnaire; range, 0-3 [more daytime sleepiness]) were self-reported. Neighborhood characteristics included disadvantage, per capita violent crime (census tract level), and safety (self-reported and individual level). We fit generalized linear mixed models and multinomial and binomial logistic regression models to examine the associations between neighborhood characteristics and sleep outcomes while accounting for the clustering within churches and pairs, before and after adjustment for self-reported confounders (age, gender, income, education, body mass index, depressive symptoms, hypertension, and diabetes). Results The mean hours of sleep duration is 6.7 ± 1.2, and the mean daytime sleepiness is 0.8 ± 0.9. Neighborhood characteristics were not associated with sleep duration. Higher perceived neighborhood safety was associated with an 18.4% lower odds of daytime sleepiness in the unadjusted model (odds ratio, 0.82 [95% confidence interval, 0.69-0.96]). The association was attenuated in the fully adjusted model. Neighborhood disadvantage and violent crime were related to lower daytime sleepiness; however, associations were not statistically significant. Conclusion Self-reported neighborhood safety was associated with lower daytime sleepiness. Future exploration of the pathways linking neighborhood characteristics and sleep is warranted.
Complex FIR block adaptive digital filtering algorithm with independent adaptation of real and imaginary filter parameters

Complex signal representations are being frequently employed in various adaptive filtering applications such as wireless communications, beamforming, etc. In this paper, a novel complex optimum block adaptive algorithm with individual adaptation of parameters (Complex OBAI-LMS) is presented. The proposed technique effectively utilizes the degrees of freedom of the adaptive filter by individually adapting the real and imaginary components of the complex adaptive finite impulse response (FIR) filter coefficients employing optimally derived convergence factors. In addition, the convergence factors are updated at each block iteration. The formulation of the complex OBAI-LMS shows that the update vectors for the real and imaginary components of the adaptive filter coefficients are estimates of the Wiener solution at each iteration. Furthermore, the matrix inversion operation in the formulation is eliminated by processing the input signal in overlapping blocks and applying a matrix inversion lemma. The convergence properties of the complex OBAI-LMS are compared to the block implementation of the complex LMS algorithm in the estimation of a complex FIR filter. Simulation results show that the complex OBAI-LMS yields a significant improvement in convergence speed over the block complex LMS for different input training signals.
Micron-scale mapping of sulfur cycling across the oxycline of a cyanobacterial mat: a paired nanoSIMS and CARD-FISH approach.

The metabolic activities of microbial mats have likely regulated biogeochemical cycling over most of Earth's history. However, the relationship between metabolic activity and the establishment of isotopic geochemical gradients in these mats remains poorly constrained. Here we present a parallel microgeochemical and microbiological study of micron-scale sulfur cycling within hypersaline microbial mats from Guerrero Negro, Baja California Sur, Mexico. Dissolved sulfide within the mats was captured on silver discs and analyzed for its abundance and δ^(34)S isotopic composition using high-resolution secondary ion mass spectrometry (nanoSIMS). These results were compared to sulfide and oxygen microelectrode profiles. Two-dimensional microgeochemical mapping revealed well-defined laminations in sulfide concentration (on scales from 1 to 200 μm), trending toward increased sulfide concentrations at depth. Sulfide δ^(34)S decreased from ~+10‰ to −20‰ in the uppermost 3 mm and oscillated repeatedly between −10‰ and −30‰ down to a depth of 8 mm. These variations are attributed to spatially variable bacterial sulfate reduction within the mat. A parallel examination of the spatial distribution of known sulfate-reducing bacteria within the family Desulfobacteraceae was conducted using catalyzed reporter deposition fluorescence in situ hybridization. Significant concentrations of Desulfobacteraceae were observed in both oxic and anoxic zones of the mat and occurred in several distinct layers, in large aggregates and heterogeneously dispersed as single cells throughout. The spatial distribution of these microorganisms is consistent with the variation in sulfide concentration and isotopic composition we observed. The parallel application of the methodologies developed here can shed light on micron-scale sulfur cycling within microbially dominated sedimentary environments.
The Effects of Stimulus Dimension and Mode of Exploration on Original Thinking in Preschool Children.

This study was concerned with the effects of stimulus dimension (two vs. three dimensions), mode of exploration (visual or haptic), and the combination of these two variables on preschool children's responses to pattern meanings and unusual uses tasks of original thinking. Eighty children (aged 4 years 10 months to 5 years 5 months) were randomly assigned to four task conditions. To determine the construct validity of each type of stimulus presentation, four criteria were identified and examined. The findings indicated that in measuring original thinking, in terms of ideational fluency, presentation of tasks in 3-D yields higher scores than in 2-D form and that permitting visual and haptic exploration does afford higher scores than does use of visual only. That is, the 3-D in comparison with 2-D tasks generated more responses overall and more unique high quality responses in particular. Furthermore, the combination of 3-D with visual and haptic exploration is the only condition studied to meet all criteri...