cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular modeling study of the permeability-selectivity trade-off in polymeric and microporous membranes

A permeability−selectivity trade-off is observed in kinetic (diffusion-based) separations, such as oxygen/nitrogen, on polymeric and inorganic microporous membrane materials. Some materials are inherently better than others in the trade-off, but the molecular-level reasons are not clear. In this paper, we employed a molecular modeling approach to study the oxygen/nitrogen separation and provide insight into optimizing the pore characteristics (geometry, material of construction) for separation performance. The pore models were abstract, with features representative of different microporous or polymeric materials. They comprised three-dimensional atomistic models of unidirectional pores with diameters <5 A; various aspects of the pore geometry and material of construction were varied. Oxygen and nitrogen were modeled as rigid dimers, and the Lennard-Jones (LJ) potential was used to model the gas−pore site interactions. Free energy calculations and transition-state theory were used to predict the permeation...
The relation of vitamin D intake to the age of the infant at the time of eruption of the first deciduous incisor

Summary The ages at eruption of the first deciduous lower central incisor of groups of healthy infants with carefully controlled diets having relatively low, intermediate, and high amounts of supplementary vitamin D were compared. The incisors of twenty-two infants given the intermediate vitamin D intake, from 300 to 400 units daily, showed the earliest mean age at eruption, 24.68 weeks. The incisors of seventeen infants with a low vitamin D intake, from 135 to 270 units daily, were delayed in their eruption, appearing at a mean age of 28.29 weeks. Incisors of six infants with a high vitamin D intake, over 1,800 units daily, also seemed delayed in their eruption, appearing at a mean age of 27.16 weeks; however, this is less conclusive because of the small number of infants in this group. In an effort to determine whether early or late eruption is more nearly normal, the dental eruption data of six infants who had the 300- to 400-unit intake but who were subject to illnesses were presented. Although the group is small, the mean age of incisor eruption, 29.0 weeks, seemed to indicate that illness delays tooth eruption and that the earlier eruption age is more nearly normal. The response of dental eruption to variation in vitamin D intake tends to parallel the responses of linear growth and mineral retention to the same influence during infancy.
Improved method for the automated determination of E 0 for lithography SPC

The clearing dose, E0 is a commonly used parameter for measuring lithography process stability. Unfortunately, it is often difficult to accurately determine E0 utilizing the common technique of visual inspection. In this work, we outline an automated technique for the determination of E0 that is suitable for the volume manufacturing environment. This technique takes advantage of the ability of currently available automated film thickness metrology tools to take a large volume of resist thickness data over a range of exposure energies. The resulting contrast curve is then sliced to isolate the linear region, regressed, and extrapolated to generate a value for E0 that is suitable for use in process control. This algorithm is reduced to computer code and tuned for optimum performance. Regression statistics indicate that this type of fit is quite robust, with R2 values typically in excess of 0.95. Capability studies show the repeatability of this method to be far superior to traditional techniques, with single wafer reproducibility well below 1mJ/cm2. This improved method for the determination of E0 enjoys the benefits of accuracy and automation as compared to traditional visual methods. In addition to presenting the technique described above, we show the correlation of the new technique with induced process 'drifts,' thereby demonstrating its usefulness as a process monitor.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
UV Perturbations in Brane Gas Cosmology

We consider the effect of the ultraviolet (UV) or short wavelength modes on the background of brane gas cosmology. We find that the string matter sources are negligible in the UV and that the evolution is given primarily by the dilaton perturbation. We also find that the linear perturbations are well behaved and the predictions of brane gas cosmology are robust against the introduction of linear perturbations. In particular, we find that the stabilization of the extra dimensions (moduli) remains valid in the presence of dilaton and string perturbations.
Influence of small amounts of Fe and V on the synthesis and stability of Ti3SiC2

Abstract Polycrystalline bulk samples of (Ti1-yMey)3SiC2, where Me=Fe or V and y=0.01 to 0.1, were fabricated by reactive hot isostatic pressing of a mixture of Ti, C (graphite), SiC and Fe or V at 1450°C for 4 h under a pressure of 60 MPa. X-ray diffraction and scanning electron microscopy of the fully dense samples have shown that small amounts of Fe and V interfere with the reaction between Ti, C and SiC leading to the presence of SiC, TiCx, as well as different Fe and V-containing phases in the final microstructures. The presence of these impurity phases also reduces the temperature at which Ti3SiC2 decomposes. The decomposition is manifested by the formation of a network of pores when the samples are annealed at 1600°C, a temperature at which pure Ti3SiC2 is thermally stable. The concentration threshold for this decomposition is as low as 1 at%.
An estimation approach to extract multimedia information in distributed steganographic images

Distributed image steganography (DIS) (Y.S. Wu et al., 2004) is a new method of concealing secret information in several host images, leaving smaller traces than conventional steganographic techniques, and requiring a collection of affected images for secret information retrieval. Fusion system designs of the future will require enhanced security measures for distributed data communication. DIS, compared to other conventional steganographic techniques, can improve security and information hiding capacity because DIS leaves reduced signatures of hidden information in host images. The open literature does not offer effective detection methods and countermeasures for DIS, indicating that it can be potentially usable to criminals for unchallenged covert communication over the Internet and fusion architectures. In this paper, we explore a new information extraction method for both detecting and reversing DIS method by considering images as pseudo-random processes. The key idea is to estimate secret image as a random process, which is corrupted by a noise source (i.e. host image). The secret images may be nonlinear, non-Gaussian and non- stationary in nature, and can be disclosed by using some estimation techniques such as Kalman filtering. Our proposed method demonstrates great promise to reveal a secret image. Consequently, it is useful for intelligence gathering and information extraction in steganographic - images produced by DIS.
5-Ethynyl-2(1H)-pyrimidinone: Aldehyde oxidase-activation to 5-ethynyluracil, a mechanism-based inactivator of dihydropyrimidine dehydrogenase

Abstract 5-Ethynyluracil is a potent mechanism-based inactivator of dihydropyrimidine dehydrogenase (DPD, EC 1.3.1.2) in vitro (Porter et al., J Biol Chem 267 : 5236–5242, 1992) and in vivo (Spector et al., Biochem Pharmacol , 46 : 2243–2248, 1993. 5-Ethynyl-2(1 H )-pyrimidinone was rapidly oxidized to 5-ethynyluracil by aldehyde oxidase. The substrate efficiency ( k cat / K m ) was 60-fold greater than that for N -methylnicotinamide. In contrast, xanthine oxidase oxidized 5-ethynyl-2(1 H )-pyrimidinone to 5-ethynyluracil with a substrate efficiency that was only 0.02% that of xanthine. Because 5-ethynyl-2(1 H )-pyrimidinone did not itself inactivate purified DPD in vitro and aldehyde oxidase is predominately found in liver, we hypothesized that 5-ethynyl-2(1 H )-pyrimidinone could be a liver-specific inactivator of DPD. We found that 5-ethynyl-2(1 H )-pyrimidinone administered orally to rats at 2 μg/kg inactivated DPD in all tissues studied. Although 5-ethynyl-2(1 H )-pyrimidinone produced slightly less inactivation than 5-ethynyluracil, the two compounds showed fairly similar patterns of inactivation of DPD in these tissues. At doses of 20 μg/kg, however, 5-ethynyl-2-pyrimidinone and 5-ethynyluracil produced equivalent inactivation of DPD. Thus, 5-ethynyl-2(1 H )-pyrimidinone appeared to be an efficient, but not highly liver-selective prodrug of 5-ethynyluracil.
Tyrosine kinase inhibitors: A clinical perspective

Cancer treatment has so far been restricted to cytotoxic and hormonal agents. These have been of limited value in their efficacy and their toxicity profile. A new era of targeted therapies is rapidly evolving. A key target being actively pursued is the receptor tyrosine kinase. Several compounds that inhibit this target are in preclinical and clinical development. These compounds broadly fall into two categories: monoclonal antibodies and small-molecule inhibitors. The common targets are epidermal growth factor receptor, Bcr-Abl tyrosine kinase, vascular endothelial growth factor, fibroblast growth factor receptor, and platelet-derived growth factor. Two of these compounds, trastuzumab and imatinib mesylate, have been approved by the US Food and Drug Administration for use in specific indications. Other uses are being tested, such as imatinib for gastrointestinal stromal tumor. These compounds will alter cancer care as adjuncts to currently available treatment options.
Studies of 125I trace labeling of immunoglobulin G by chloramine-T.

Detailed studies of the parameters which effect the trace iodination of IgG with 125I, at levels of 1 atom/4000–10,000 moles IgG, using chloramine-T, are described. The following observations were noted: (1) The reactions, (a) the formation of ‘active iodine’ (H2OI+) and, (b) the incorporation of ‘active iodine’ into protein, that comprise the over-all iodination of proteins have been studied separately and together. (2) With IgG, pH, 7·0 and 2° were optimal and reproducible for both reactions (a) and (b), and for the over-all reaction. Among the parameters which were found to influence the individual and over-all reactions and which were studied to establish optimal conditions were the concentrations of oxidant, iodide, and protein as well as pH, time, temperature, ionic strength, and particular batch of protein. (3) Different proteins and separate lots of the same protein show variable amounts of residues which are oxidized prior to the incorporation of iodine. (4) No differences in the immunochemical precipitation characteristics were detected between untreated IgG and IgG iodinated by the present method. (5) Calculations of the distribution of IgG species, iodinated at a level of 1 atom iodine per 4000–10,000 moles IgG, shows the population of iodinated molecules to be essentially homogeneous and in all likelihood, monosubstituted. (6) Typical conditions for labeling IgG at a level of approximately 1 atom iodine/5000 molecules IgG are described in detail.
A Spectroscopic Survey of Metallic Species Abundances in the Lunar Atmosphere

Abstract The first results of an ongoing effort to search for new species in the lunar atmosphere are presented. The observations in terms of the degree to which atomic metal abundances in the lunar atmosphere are stoichiometric, that is, proportional to surface abundances (as the Na:K ratio is), are discussed. Na and K are the only atmospheric constituents to have been observed from Earth, but Apollo sample returns established that a variety of species are more abundant in the lunar surface than either Na or K. Simple stoichiometric arguments (i.e., assuming atmospheric production proportional to surface abundance) predict that relatively abundant lunar surface constituents such as Si, Al, Ca, Mg, Fe, and Ti should be more abundant in the lunar atmosphere than either Na or K. The 2.7-m coude and 2.1-m cassegrain echelle spectrographs at the University of Texas McDonald Observatory were used to investigate this hypothesis by searching for solar resonant scattering lines of nine metallic species between 3700 and 9700 A. Spectra were taken 20 arcsec above the apparent subsolar limb of the Moon near quarter phase on 30 July 1994 and 10–12 March 1995. Upper limits were obtained for the first time for the abundant lunar surface species Si, Al, Ca, Fe, and Ti, as well as Ba and the alkalis Li, Rb, and Cs. In the cases of Si, Ca, Fe, and Ti, the derived upper limits are more than an order of magnitude lower than the simple stoichiometric model predicts. The upper limits for Li and Al are less constraining. The Ba, Rb, and Cs upper limits lead to the conclusion that those species are not stoichiometrically overabundant above the detection threshold in the atmosphere. It is concluded that the stoichiometric Na:K ratio is peculiar in that the mechanism(s) that produce the lunar Na and K atmosphere somehow favor those atomic species over many more or comparably abundant lunar surface species.
Infinite Dilution Activity Coefficients and Miscibility Using a Modified Static Total Pressure Method

This paper presents a modified static total pressure method coupled with appropriate data analysis procedures which provide infinite dilution activity coefficients (γ∞) and solubility (xsat) for volatile organic compounds in water. A large, calibrated vapor space minimizes the impact of noncondensable compounds. The degassed solute is micrometered incrementally into the cell containing water. The meterings continue into the two-liquid-phase region. This results in a discontinuous P,z curve. The number of measurements taken for each experimental composition are greater than the number required to establish equilibrium. Data reconciliation methods accounting for the errors allow use of all measurements to provide estimates of γ∞ and xsat. Experimental design methods testing the impact of experimental errors, potential sources of bias, and the number and volume of the solute meterings verify the accuracy and precision of the resultant γ∞ and xsat values. Experimental results for acetone + water and experimen...
Farm Labor Issues and Policies: Discussion

Tonight the Immigration and Naturalization Service (INS) will apprehend 2,500 aliens who are illegally in the United States. Perhaps twice that number will elude "La Migra," the name used by the Mexicans, who comprise 90% of all apprehensions, to describe the Border Patrol. This cat-and-mouse game is played along the border every day, yielding almost 1 million apprehensions and perhaps 2 million illegal entries into the United States each year. Many aliens are apprehended several times, and others come to the United States only for seasonal jobs; but the INS estimates that the stock of illegal aliens is increasing by 500,000 persons annually. Illegal immigration is a major unresolved national dilemma. Despite five blue ribbon studies and Senate passage (81-18) of the Simpson-Mazzoli Immigration Reform and Control Act of 1982 (S.2222/H.R.6514) on 17 August 1982, most observers believe that immigration reform will continue to be blocked in Congress. One reason immigration is so difficult to reform is that there is little logical and relevant immigration research available to dispel myths and to guide policy makers toward a consensus.
On the analysis and design of CUSUM-Shewhart control schemes

In recent years cumulative sum (CUSUM) control charts have become increasingly popular as an alternative to Shewhart's control charts. These charts use sequentially accumulated information in order to detect out-of-control conditions. They are philosophically related to procedures of sequential hypothesis testing (the relation being similar to that existing between Shewhart's charts and classical procedures for hypothesis testing). In the present paper we present a new approach to design of CUSUM-Shewhart control schemes and analysis of the associated run length distributions (under the assumption that the observations correspond to a sequence of independent and identically distributed random variables). This approach is based on the theory of Markov chains and it enables one to analyze the ARL (Average Run Length), the distribution function of the run length, and other quantities associated with a CUSUM-Shewhart scheme. In addition, it enables one to analyze situations in which out-of-target conditions are not present initially, but rather appear after a substantial period of time during which the process has operated in on-target mode (steady state analysis). The paper also introduces an APL package, DARCS, for design, analysis, and running of both one- and two-sided CUSUM-Shewhart control schemes and gives several examples of its application.
Dynein is the motor for retrograde axonal transport of organelles

Vesicular organelles in axons of nerve cells are transported along microtubules either toward their plus ends (fast anterograde transport) or toward their minus ends (retrograde transport). Two microtubule-based motors were previously identified by examining plastic beads induced to move along microtubules by cytosol fractions from the squid giant axon: (i) an anterograde motor, kinesin, and (ii) a retrograde motor, which is characterized here. The retrograde motor, a cytosolic protein previously termed HMW1, was purified from optic lobes and extruded axoplasm by nucleotide-dependent microtubule affinity and release; microtubule gliding was used as the assay of motor activity. The following properties of the retrograde motor suggest that it is cytoplasmic dynein: (i) sedimentation at 20-22 S with a heavy chain of Mr greater than 200,000 that coelectrophoreses with the alpha and beta subunits of axonemal dynein, (ii) cleavage by UV irradiation in the presence of ATP and vanadate, and (iii) a molecular structure resembling two-headed dynein from axonemes. Furthermore, bead movement toward the minus end of microtubules was blocked when axoplasmic supernatants were treated with UV/vanadate. Treatment of axoplasmic supernatant with UV/vanadate also blocks the retrograde movement of purified organelles in vitro without changing the number of anterograde moving organelles, indicating that dynein interacts specifically with a subgroup of organelles programmed to move toward the cell body. However, purified optic lobe dynein, like purified kinesin, does not by itself promote the movement of purified organelles along microtubules, suggesting that additional axoplasmic factors are necessary for retrograde as well as anterograde transport.
The effect of phosphor K x-rays on the MTF of rare-earth screens

The LSF’s and MTF’s of two high resolution rare‐earth screen‐film combinations were measured at two beam qualities. The two beam qualities were chosen to provide x‐ray spectral distributions either above or below the K‐edge of the screen phosphor. The LSF’s were found to be photon energy dependent. This energy dependence is attributed to the generation and reabsorption of phosphorK x‐rays resulting in a broadening of the LSF.
Structural basis for a hand-like site in the calcium sensor CatchER with fast kinetics.

Calcium ions, which are important signaling molecules, can be detected in the endoplasmic reticulum by an engineered mutant of green fluorescent protein (GFP) designated CatchER with a fast off-rate. High resolution (1.78–1.20 A) crystal structures were analyzed for CatchER in the apo form and in complexes with calcium or gadolinium to probe the binding site for metal ions. While CatchER exhibits a 1:1 binding stoichiometry in solution, two positions were observed for each of the metal ions bound within the hand-like site formed by the carboxylate side chains of the mutated residues S147E, S202D, Q204E, F223E and T225E that may be responsible for its fast kinetic properties. Comparison of the structures of CatchER, wild-type GFP and enhanced GFP confirmed that different conformations of Thr203 and Glu222 are associated with the two forms of Tyr66 of the chromophore which are responsible for the absorbance wavelengths of the different proteins. Calcium binding to CatchER may shift the equilibrium for conformational population of the Glu222 side chain and lead to further changes in its optical properties.
The Mirror Neuron System: A Neural Substrate for Methods in Stroke Rehabilitation:

Mirror neurons found in the premotor and parietal cortex respond not only during action execution, but also during observation of actions being performed by others. Thus, the motor system may be activated without overt movement. Rehabilitation of motor function after stroke is often challenging due to severity of impairment and poor to absent voluntary movement ability. Methods in stroke rehabilitation based on the mirror neuron system--action observation, motor imagery, and imitation--take advantage of this opportunity to rebuild motor function despite impairments, as an alternative or complement to physical therapy. Here the authors review research into each condition of practice, and discuss the relevance of the mirror neuron system to stroke recovery.
College student learning from televised versus conventional classroom lectures: A controlled experiment

In a controlled experiment, students in two sections of introductory sociology were exposed either to conventional classroom lectures or to the same lectures broadcast live in an adjacent room on a television monitor. Except for the first round of six lectures, when technical problems appeared to have lowered test performance by the experimental groups, learning under the two lecturing modes was statistically equivalent. Self-reported class attendance, also, seemed to have been unaffected by lecturing modes. This study confirms the general pattern of results from a number of prior, albeit less rigorously designed, studies of live vs. televised lecture courses.
Current Ethical Issues in Child and Adolescent Psychotherapy

Core ethical principles for the conduct of psychotherapy with children and adolescents transcend times, trends, and jurisdictions. Advances in technology, variations in state law, and the evolution of federal law should stimulate consideration of how these ethical principles apply to new situations; however, the guiding compass remains the psychotherapist's obligation to create and protect the integrity of the psychotherapeutic space to provide the child or adolescent the freedom to identify, examine, explore, and hopefully resolve the issues that bring one to treatment. Boundaries, privacy, confidentiality, and the patient's autonomy are components of this space. Together, they reflect a basic respect for the patient central to professional conduct and essential to any effective treatment process.
Cyberspace meets brick and mortar: an investigation into how students engage in peer to peer feedback using both cyberlearning and physical infrastructures

Cyberlearning infrastructures are increasingly being integrated into physical classrooms and are often used by online classes as an outright replacement for the physical classroom. In Spring 2009, The Educational Game Design Class, taught at the University of Colorado Boulder, employed a cyberlearning infrastructure enabling students to run and even download classmate assignment submissions before the homework deadline. This cyberlearning infrastructure, called the Scalable Game Design Arcade, also allowed students to give feedback on other students' assignments. Analysis of data from the Scalable Game Design Arcade indicates that students used the online infrastructure to play and appraise fellow students' games. Interestingly however, data suggests that most students preferred to give feedback verbally in-person during class; data also indicates that in-class feedback was the most effective in terms of getting students to improve and resubmit their assignments.
Collisional deactivation rates for A 2Σ+ (ν′ = 1) state of OH

Abstract Rates for rotational transfer, vibrational crossover, and electronic quenching have been determined for specific rotational levels, N ′, of A 2 Σ + , ν′ = 1, OH radicals in the presence of N 2 and O 2 quenching gases. Measurements of total rates of depletion of specific rotational levels, rates of energy transfer out of the ν′ = 1 state, and fluorescence spectra were made at room temperature utilizing a low-pressure OH flow system. Total rates of depletion and rotational transfer rates for N 2 and O 2 quenching gases show a weak dependence upon N ′. The N 2 quenching rates for these processes and for vibrational crossover were faster than the O 2 rates. Conversely, the O 2 rates for electronic quenching were greater than the N 2 rates.
Simulation of edge plasmas in DIII-D double-null configurations

We present fluid model simulation results for the edge plasma in the DIII-D tokamak with unbalanced double-null magnetic configurations, including cross field drifts. Input parameters are typical of low-power operation in DIII-D. For high-recycling the plasma tends to be detached from all divertor plates. Midplane plasma and electric field profiles are relatively insensitive to the magnetic imbalance. Divertor heat flux profiles exhibit sharp peaks due to cross-field drifts when the ion grad-B drift direction is away from the x-point toward the magnetic axis.
N-Butyldeoxynojirimycin inhibits murine melanoma cell ganglioside metabolism and delays tumor onset

Aberrant ganglioside metabolism is linked to tumor progression. Since ganglioside depletion reduced tumorigenicity of MEB4 murine melanoma cells, we studied N-butyldeoxynojirimycin (NB-DNJ), an imino sugar administered orally to inhibit glucosylceramide (GlcCer) synthase in patients with glycosphingolipid storage diseases, for effects on MEB4 melanoma tumor cell ganglioside metabolism, cell biology, and tumorigenesis. Here we show that 50 μM NB-DNJ reduced MEB4 cell GlcCer synthase activity (by 70%), ganglioside synthesis (by 61%), and shedding (by 37%) while ceramide concentrations and cell viability were unaffected. Partial ganglioside depletion caused a delay in tumor onset but not in tumor incidence, possibly because of rapid (48 h) ganglioside recovery. The delay in tumor development by NB-DNJ treatment of MEB4 cells provides further support for the concept of tumor cell ganglioside metabolism as a therapeutic target in cancer.
Competitive Pairing and the Chemistry of Coadsorbed Hydrogen and Halogens on Ge(100)

Abstract : The chemistry of coadsorbed H and X (X=Cl, Br) on semiconductor surfaces is important in epitaxial growth of silicon from chlorosilanes and of Si(x)Ge(l-x) alloys, in hydrogenating/ halogenating cycles in atomic layer epitaxy, and also provides an interesting model system, yet has received little attention to date. We have investigated the interaction of HCl and HBr with Ge(100) by temperature-programmed desorption, and find that H2, HCl and HBr each desorb with near-first-order kinetics near 570-590 K and that GeC12 and GeBr2 desorb with near-second-order kinetics near 675 K and 710 K, respectively. Analysis of the desorption kinetics of H2 and HX leads to the conclusion that adsorbed H and X atoms pair preferentially in a qualitatively similar way as H atoms adsorbed alone on Ge(100)2xl or Si(100)2xl and that pairing of H+X occurs in competition with pairing of H+H.
Flow Cytometric Changes That Precede Cancer: Premalignant Gastrointestinal Disease

Abnormalities in cellular DNA content and proliferative rate are observed not only in cancer, but may be seen in premalignant disease as part of the multistep process of progression towards malignancy during carcinogenesis. Flow cytometry can be used to document these premalignant changes. Several gastrointestinal diseases provide good models for studying these abnormalities as early detectors which may select those patients at greatest risk for progression to cancer.
Thin-layer chromatography of sucrose esters and mixtures of raffinose and sucrose☆

Abstract The technique of qualitative and quantitative silica gel chromatography on glass strips has been adapted to separate mixtures of sucrose esters, and sucrose and raffinose. Solvent mixtures are described which give rapid, definitive separations of these compounds. The separated components can be eluted from the silica gel and measured for sucrose content by the colorimetric procedure of Roe.
ANG II signaling in vasa recta pericytes by PKC and reactive oxygen species

ANG II constricts descending vasa recta (DVR) through Ca(2+) signaling in pericytes. We examined the role of PKC DVR pericytes isolated from the rat renal outer medulla. The PKC blocker staurosporine (10 microM) eliminated ANG II (10 nM)-induced vasoconstriction, inhibited pericyte cytoplasmic Ca(2+) concentration ([Ca(2+)](cyt)) elevation, and blocked Mn(2+) influx into the cytoplasm. Activation of PKC by either 1,2-dioctanoyl-sn-glycerol (10 microM) or phorbol 12,13-dibutyrate (PDBu; 1 microM) induced both vasoconstriction and pericyte [Ca(2+)](cyt) elevation. Diltiazem (10 microM) blocked the ability of PDBu to increase pericyte [Ca(2+)](cyt) and enhance Mn(2+) influx. Both ANG II- and PDBu-induced PKC stimulated DVR generation of reactive oxygen species (ROS), measured by oxidation of dihydroethidium (DHE). The effect of ANG II was only significant when ANG II AT(2) receptors were blocked with PD-123319 (10 nM). PDBu augmentation of DHE oxidation was blocked by either TEMPOL (1 mM) or diphenylene iodonium (10 microM). We conclude that ANG II and PKC activation increases DVR pericyte [Ca(2+)](cyt), divalent ion conductance into the cytoplasm, and ROS generation.
Topological singularities in cortical orientation maps: the sign theorem correctly predicts orientation column patterns in primate striate cortex

Optical imaging methods have revealed the spatial arrangement of orientation columns across striate cortex, usually summarized in terms of two measurements at each cortical location: (i) a ‘best’ stimulus orientation, corresponding to the stimulus orientation that elicits a maximal response, and (ii) the magnitude of the response to the best orientation. This mapping has been described as continuous except at a set of singular points (also termed ‘vortices’ or ‘pinwheels’. Although prior work has shown that vortex patterns qualitatively similar to those observed in visual area 17 of the Macaque cortex can be produced by either band-pass or low-pass filtering of random vector fields, there has been to date little further topological characterization of the structure of cortical vortex patterns. Nevertheless, much theoretical work has been done in other disciplines on mappings analogous to the cortical orientation map. In particular, a recent theorem in the optics literature, termed the sign principle, stat...
Photodeposition of polydiacetylene thin films for photonic applications in 1-g and in microgravity

Polydiacetylenes are a unique class of highly conjugated organic polymers that are of interest for both electronic and photonic applications. Many of these applications require high quality thin polydiacetylene films, i.e., films possessing minimal impurities and inhomogeneities, uniform thicknesses, and few defects such as light scattering centers. The growth of such films is not trivial. Photodeposition from solution is a novel process, discovered in our laboratory, which shows excellent potential for producing high quality polydiacetylene films, superior to those grown by conventional techniques. The basic method is quite simple; a diacetylene monomer solution is irradiated with UV light through quartz, glass, or other transparent substrate and a thin polydiacetylene film results. During the course of this process thermal density gradients arise due to uneven heat generation throughout the monomer solution. These gradients can then, under the influence of gravity, give rise to buoyancy-driven convection. Additionally, changes in monomer concentration may induce solutal convection. This convection affects transport of material to and from the growing polydiacetylene film, and thus affects the dynamics of the growth process, and thereby also the microstructure, morphology, and properties of the film. Evidence of this is seen when the films are viewed under a microscope; they exhibit small particles of solid polymer which form in the bulk solution, get transported by convection to the surface of the growing film, and become embedded. Also convection tends to cause the film thicknesses to be less uniform, and may even affect the molecular orientation of the films. We have been actively studying the fundamental science of diacetylene polymerization in solution and polydiacetylene film photodeposition from solution, including the kinetics, mechanism, and photo-chemistry of the process, and the nature and properties of the films obtained. Initial results of this work have just been published in J. Am. Chem. Soc. The thrust of our research is to investigate in detail, both in 1-g and in low-g, the effects of convection (and the lack thereof) on this novel and interesting reaction.
Peer Interactions and Social Acceptance of Elementary-Age Children with Severe Disabilities in an Inclusive School.

Although there has been much attention paid to the social relationships of students with severe disabilities in integrated environments, few studies depict the kinds of interactions that can be expected in mainstreamed classrooms. Such information is important for designing classroom ecologies and interventions that will maximize developmental opportunities for all students. Eight children with severe disabilities and eight nonhandicapped peers were observed in their regular elementary school classrooms. Students with severe disabilities received more social approaches than they made. These interactions tended to be receiving assistance, although talk, play, and physical affection were also prevalent. Over the school year the number of interactions declined; however, the pattern (proportions of different types of interaction) became more typical (like those of nonhandicapped peers). Acceptance was measured by sociometric nomination, revealing that some of the students with severe disabilities were very po...
Bufferless optical Clos switches for data centers

A bufferless optical Clos switch called PetaX is designed to provide high-bandwidth data exchange for data center networks. PetaX combines the best features of electronics and optics and achieves good performance with low complexity.
I just made love: the system and the subject of experience

Experience has become increasingly relevant to the field of HCI in recent decades and a number of approaches have been drawn from multiple disciplines to engage this rich and elusive topic. In this work, we provide a critical interpretative account of the experience of using a sexually oriented social media website called I Just Made Love. We do this by critically interpreting the traces of interaction, user data populating the site, to understand the role of the systemic structures that shape the subject of interaction and in turn the experience. We approach this experience from the perspective of the subject of interaction as opposed to the user and introduce some benefits of such a strategy. Through our insights and discussion, we explore how design choices at IJML contribute to certain types of sexual performances and intimate experiences.
Human immunodeficiency virus type 1 nucleocapsid protein reduces reverse transcriptase pausing at a secondary structure near the murine leukemia virus polypurine tract.

In an earlier study on minus-strand DNA synthesis catalyzed by murine leukemia virus reverse transcriptase, we described a prominent pause site near the polypurine tract (J. Guo, W. Wu, Z. Y. Yuan, K. Post, R. J. Crouch, and J. G . Levin, Biochemistry 34:5018-5029, 1995). We now report that pausing at this site is due to a stem-loop structure in the RNA template, formed by interaction of a number of bases in the polypurine tract, including the six G's, and a 3' sequence which includes four C's. Addition of human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein to reverse transcriptase reactions reduces pausing by approximately 8- to 10-fold and stimulates synthesis of full-length DNA. Thus, NC functions as an accessory protein during elongation of minus-strand DNA and increases the efficiency of DNA synthesis, in this case, by apparently destabilizing a region of secondary structure in the template. Since NC is associated with genomic RNA in the viral core and is likely to be part of a viral replication complex, these results suggest that NC may also promote efficient DNA synthesis during virus replication. Mutational analysis indicates that the features of HIV-1 NC which are important for reduction of pausing include the basic amino acids flanking the first zinc finger, the zinc fingers, and the cysteine and aromatic amino acids within the fingers. These findings suggest that reverse transcription might be targeted by drugs which inactivate the zinc fingers of HIV-1 NC.
Melatonin Supplements for Aging

AbstractTo The Editor: For many years physiologists considered the pineal gland, lodged deep within the brain, a vestigial organ which was merely an anatomical remnant of a primary sensory system. However, over the past decade scientists have come to recognize melatonin, a product of the pineal gland, as a “master hormone” involved in the control of biological rhythms (Ebadi, 1984; Erlich & Apuzzo, 1985; Foley et al., 1986; Reiter, 1991) and more recently, it has been suggested that melatonin acts at a cellular level to regulate the genetic switching occurring in the cells throughout the body which promotes the aging process (Kloeden et al., 1990). Consequently, melatonin has been suspected as having anti-aging properties (Nair et al., 1986; Armstrong & Redman, 1991; Pierpaoli & Maestroni, 1987; Trentini et al., 1991) and the progressive decline in melatonin secretion with age (Nair et al., 1986; Sack et al., 1986; Thomas & Miles, 1989) led to the hypothesis that aging may be secondary to progressive pine...
A Link between Secretion and Pre-mRNA Processing Defects in Saccharomyces cerevisiae and the Identification of a Novel Splicing Gene, RSE1

Secretory proteins in eukaryotic cells are transported to the cell surface via the endoplasmic reticulum (ER) and the Golgi apparatus by membrane-bounded vesicles. We screened a collection of temperature-sensitive mutants of Saccharomyces cerevisiae for defects in ER-to-Golgi transport. Two of the genes identified in this screen were PRP2, which encodes a known pre-mRNA splicing factor, and RSE1, a novel gene that we show to be important for pre-mRNA splicing. Both prp2-13 and rse1-1 mutants accumulate the ER forms of invertase and the vacuolar protease CPY at restrictive temperature. The secretion defect in each mutant can be suppressed by increasing the amount of SAR1, which encodes a small GTPase essential for COPII vesicle formation from the ER, or by deleting the intron from the SAR1 gene. These data indicate that a failure to splice SAR1 pre-mRNA is the specific cause of the secretion defects in prp2-13 and rse1-1. Moreover, these data imply that Sar1p is a limiting component of the ER-to-Golgi transport machinery and suggest a way that secretory pathway function might be coordinated with the amount of gene expression in a cell.
A Systematic Review of Dietary Assessment Tools for Children Age 11 Years and Younger

Dietary assessment tools are useful in nutritional epidemiology for identifying dietary patterns in both children and adults. Most commonly, dietary assessment methods include 24-hour recalls, food...
Functional brain mapping and its applications to neurosurgery.

FUNCTIONAL BRAIN MAPPING may be useful for both preoperative planning and intraoperative neurosurgical decision making. “Gold standard” functional studies such as direct electrical stimulation and recording are complemented by newer, less invasive techniques such as functional magnetic resonance imaging. Less invasive techniques allow more areas of the brain to be mapped in more subjects (including healthy subjects) more often (including pre- and postoperatively). Expansion of the armamentarium of tools allows convergent evidence from multiple brain mapping techniques to bear on pre- and intraoperative decision making. Functional imaging techniques are used to map motor, sensory, language, and memory areas in neurosurgical patients with conditions as diverse as brain tumors, vascular lesions, and epilepsy. In the future, coregistration of high resolution anatomic and physiological data from multiple complementary sources will be used to plan more neurosurgical procedures, including minimally invasive procedures. Along the way, new insights on fundamental processes such as the biology of tumors and brain plasticity are likely to be revealed.
Zero forcing number: Results for computation and comparison with other graph parameters

The zero forcing number of a graph is the minimum size of a zero forcing set. This parameter is useful in the minimum rank/maximum nullity problem, as it gives an upper bound to the maximum nullity. Results for determining graphs with extreme zero forcing numbers, for determining the zero forcing number of graphs with a cut-vertex, and for determining the zero forcing number of unicyclic graphs are presented.
Location, location, location! Demonstrating the mnemonic benefit of the Method of Loci.

Classroom demonstrations of empirically supported learning and memory strategies have the potential to boost students’ knowledge about their own memory and convince them to change the way they approach memory tasks in and beyond the classroom. Students in a Human Learning and Memory course learned about the Method of Loci (MoL) mnemonic technique, then created and used their own Memory Palaces based on campus locations to remember a grocery list. Pretest to posttest improvements in memory for the serially recalled list, along with significant increases in self-reported use of MoL in daily life, suggest that this activity may improve knowledge and application of this powerful memory strategy. More broadly, these types of activities can strengthen undergraduates’ metacognitive sophistication.
Commentary to 'Non-invasive vesicoureteral reflux detection: Heating risk studies for a new device'

The standard evaluation of the child with febrile/symptomatic UTI has been renal bladder sonography and contrast VCUG. These studies have been performed to identify urological anomalies that place the child at risk for acquired renal injury, or at least morbidity from recurrent complicated UTIs. Among these anomalies, VUR remains the focus of our attention. Studies in the United States and Europe are questioning the utility of our standard diagnostic algorithm since (1) prenatal sonography detects most clinically significant GU anomalies before UTI happens, (2) the majority of children with a first febrile/symptomatic UTI are not at risk for recurrent UTI, and (3) the contemporary management of UTI and VUR has resulted in a significant reduction in the rates of acquired renal cortical scarring. In the absence of any serious problem for most children, the obvious question raised by skeptics is ‘Why subject children to invasive and costly studies when there is little to be gained?’. For pediatric urologists, sensitive to the fact that some children are at risk of significant renal scarring, the rationale remains equally obvious. And the debate continues. Newer diagnostic algorithms, such as the DMSA renal scan based ‘topedown approach’, or novel-imaging techniques may provide clinicians with a suitable compromise. The authors of this manuscript tested whether microwave warming of bladder urine could essentially ‘tag’ that urine so that reflux couldbedetectedbased ona rise in temperaturewithin the ureter. The entire technique is extracorporeal, thus avoiding catheterization, and avoids the need for radiation. Experimentation in humans should be safe and useful. The first question is, is this method safe? The authors claimed that the histological findings were probably caused
Effects of albumin and urea on hydrostatic edema in the perfused lung

Abstract Hydrostatic interstitial pulmonary edema was induced in isolated perfused canine lungs to evaluate the effects of treatment with osmotic agents. In 14 preparations after induced venous hypertension adding fluid weights of 20, 30, 40, or 60 g representing 33–100% of normal lobe weight, venous pressure was returned to levels of zero or below without additional treatment. Albumin (25 g) was added to 23 preparations and urea (10 g) added to 10 lungs prepared in a similar fashion. Reductions in pulmonary venous oxygen tension and effective compliance occurred at all levels of edema and persisted after release of venous constriction. Albumin improved venous PO 2 only after the minimal load but there was no significant effect on pulmonary compliance. No improvement in either parameter occurred after urea treatment. Significantly lower weights after albumin or urea treatment were noted after varied fluid loads but were not accompanied by proportional improvement in lung function. In the isolated lung preparation with no outlet for fluid excretion, the therapeutic effectiveness of osmotic agents alone is obviously limited, but the deleterious effects of hydrostatic interstitial edema are not readily reversed by addition of osmotic agents to the perfusate. The previously noted adverse effects of mannitol do not seem to be explained adequately on the basis of lower molecular weight alone since urea did not prove to be deleterious in this preparation.
The communication cost of selfishness

Computer scientists typically measure the computational requirements of multi-agent systems assuming that the agents behave as they should according to the rules. In particular, whenever an agent is asked about his private information (e. g., his personal preferences), the assumption is that he always responds truthfully. However, for applications with economic agents, the assumption of the agents being obedient is not acceptable. E.g., we cannot expect to model e-commerce without taking into account that agents will act selfishly given the price of an object and their own private valuation of the object. In economics, the field of mechanism design describes the properties that a multi-agent system must satisfy when the system-wide behavior depends on all of the agents' selfish behaviors. Agents' incentives can be manipulated by conditional payments and by deciding what information to make available to them. If agents are selfish, some tasks are impossible to achieve. E.g. it is impossible for a multi-agent system to allocate an object to the agent having the lowest private valuation for the object. However, even when the task is still achievable with selfish agents (perhaps using conditional payments), the computational requirements of the system might be significantly higher than the requirements with obedient agents. This dissertation analyses and characterizes this increase in computational requirements due to the selfishness of the agents. We find tight upper bounds on this "cost of selfishness" whenever possible. We present cases where there is no such cost, and cases where this cost is low. Finally, we present cases where the cost is high, but bounded, and cases where it is unbounded. Our analysis of the cost of selfishness is mainly in terms of communication requirements, but we also present results that are applicable for time and memory.