cssi/SciSciGPT-SciSciNet huggingface dataset:
Mutations in the N-Terminal Domains of Nectin-1 and Nectin-2 Reveal Differences in Requirements for Entry of Various Alphaherpesviruses and for Nectin-Nectin Interactions

Nectin-1 and nectin-2 are related molecules that can function with different specificities as entry receptors for mammalian alphaherpesviruses through interaction with viral glycoprotein D (gD). The normal function of members of the nectin family is to mediate cell-cell adhesion through homotypic and heterotypic nectin-nectin interactions in cadherin-based adherens junctions. We examined mutations in three equivalent regions of the N-terminal V-like domains of nectin-1 and nectin-2 to test the effects on entry of various alphaherpesviruses, nectin-nectin interactions, and interactions of the mutant nectins with gD. Mutations in region I previously shown to severely impair herpes simplex virus (HSV) entry activity, but not pseudorabies virus (PRV) or bovine herpesvirus 1 (BHV-1) entry, did not reduce homotypic trans interactions for either nectin-1 or nectin-2 or binding of nectin-3 to nectin-1. Mutations in region II, patterned after a reported single-nucleotide polymorphism in nectin-2, enhanced intracellular accumulation of both nectin-1 and nectin-2 and had a deleterious effect on all of the activities under study. Mutations in region III previously shown to reduce homotypic trans interactions of nectin-2 impaired the entry of PRV and BHV-1 when introduced into either nectin-1 or nectin-2, but only the nectin-2 mutation reduced HSV entry activity. Binding of nectin-1 to nectin-3 was not affected. Effects of the nectin-1 and nectin-2 mutations on interactions with gD did not necessarily correlate with entry activity of the mutant receptors. We can conclude that structural requirements for HSV entry, PRV and BHV-1 entry, and homotypic and heterotypic trans interactions are all different despite the previously reported ability of HSV and HSV gD to inhibit trans interactions.
Bacteriorhodopsin overview of fundamentals and applications

Bacteriorhodopsin (BR) is a light transducing photochromic protein in the purple membrane of a salt-loving microorganism that inhabits salt marshes. It has strong absorption in a broad region of the visible spectrum. The B- state in the photocycle can be considered to be the ground state, which has absorption maxima at 570 nm. Perhaps, the most intriguing features of this organic photopolymer are its extraordinary stability in the chemical, thermal and photochemical sense, its large optical nonlinearity, dynamic nature, durability, real-time holographic recording capabilities, and information storage potential. Furthermore, BR-doped polymer film can be fabricated for a large-scale application, whereas photorefractive crystals like BSO or KNSBM cannot be grown easily to the same dimension as BR. Hence, BR's potential in optical system includes transient dynamic applications of an M-type hologram and 3D optical memories of a branched photocycle that shows a great promise for data storage and retrieval due to its high capacity. The major advantages of this organic photopolymer include high density, low cost, low weight and portability which are a projected requirement for the Air Force and commercial applications.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Night-to-night variability of polysomnography in children with suspected obstructive sleep apnea.

Abstract Objectives: To determine whether a single polysomnographic night was a valid measure of obstructive sleep apnea syndrome (OSAS) in children with symptoms of sleep-disordered breathing. Study design: The night-to-night variability of respiratory and sleep parameters was measured prospectively in 30 snoring children aged 1.6 to 11.3 years (mean ± SD, 4.1 ± 2) by using 2 nocturnal polysomnograms performed 7 to 27 days apart (14 ± 5 days). Results: The mean of the respiratory variables including apnea index, apnea/hypopnea index, arterial oxygen saturation, and end-tidal partial pressure of carbon dioxide were not significantly different from night to night. Among the sleep parameters, there was no significant night-to-night difference in sleep efficiency, arousal index, percent rapid eye movement, or percent of slow wave sleep. Only the percentage of stage 2 was significantly different between the nights. The polysomnographic clinical diagnosis remained the same on both nights for all children, although the disease severity differed slightly in 2 patients. Conclusions: There is little clinically significant night-to-night variability in pediatric polysomnography, and no first-night effect. These data suggest that a single polysomnographic night is an adequate measure of the OSAS in children with symptoms of sleep-disordered breathing. (J Pediatr 2002;140:589-94.)
Yeast alcohol dehydrogenase II.

Abstract Many lines of evidence support the existence of a new alcohol dehydrogenase in yeast. The new enzyme showed a broad spectrum of activity with various alcohols, ethanol having the highest activity. Its properties in many respects appear to be different from the classical alcohol dehydrogenase, and the new enzyme is more able to oxidize the higher alcohols. Its physical properties also appear to be different, as indicated by the manner in which the two enzymes could be separated during the purification procedure. In other important respects the properties of the two enzymes are similar. Both are inhibited by o-phenanthroline, a property which Vallee and Hoch (10) believe is due to the presence of zinc in the enzymes. Both are readily inactivated by compounds which destroy or tie up sulfhydryl groups. The enzyme was purified over 1000-fold from the starting autolyzate, and the data seem to suggest that it is free from classical alcohol dehydrogenase.
Not all types of asynchrony are created equal.

Dear Editor,We read with interest the articleentitled, ‘‘Asynchrony, neural drive,ventilator variability and COMFORT:NAVA versus pressure support inpediatric patients’’ [1]. The authorsfound that the use of NeurallyAdjusted Ventilatory Assist (NAVA)improved patient-ventilator syn-chrony and patient comfort comparedto pressure support whether deter-mined by the treating physician oroptimized by means of protocolizedadjustments in trigger sensitivity,inspiratory rise time and terminationcriteria, airway pressure and appliedPEEP.First, we appreciate the citation ofour previous work entitled ‘‘Neurallytriggered breaths reduce trigger delayand improve ventilator response timesin ventilated infants with bronchioli-tis’’ [2]. However, the commentary onour work is not accurate. We com-pared NAVA to volume supportrather than pressure support, and itwas in human infants with bronchi-olitis, not in a mechanical lungmodel. This difference is importantbecause few studies have been pub-lished examining the use of NAVA inpediatric patients.Second, in their study, the authorslimited their documentation ofasynchrony to autotriggered, double-triggered and non-triggered breaths(types of trigger asynchrony) as wellas an asynchrony index. In a morerecent study that used the samemethodology as our infant study, wealso found that the use of NAVAsigniﬁcantly reduced the overallincidence of asynchrony, particularlytrigger asynchrony in a recoveringlung injury animal model. However,we also found that the incidence ofﬂow asynchrony, short cycles andmore common with neurally triggeredbreaths than with pneumatically trig-gered breaths [3]. Flow asynchronyoccurs if ventilator ﬂow does notequal patient ﬂow. This type ofasynchrony can be detrimental topatients because it can lead to auto-PEEP and other types of asynchrony.Short cycles may be viewed graphi-cally as double triggering and aredeﬁned as inspiratory time less thanhalf the mean inspiratory time. Theseasynchronous breaths can result fromimproperly set termination criteriasuch that the ventilator inspiratorytime ends before the patient’s inspi-ratory effort is complete. The loss ofventilator support during inspirationcan result in increased work ofbreathing. Expiratory asynchrony, inparticular shortened expiratory time,can also promote air trapping andauto-PEEP [4]. We believe that thesetypes of asynchrony should not beoverlooked, as all types of asyn-chrony can lead to prolonged durationof ventilation [5].
Picomole analysis of glutathione, glutathione disulfide, glutathione S-sulfonate, and cysteine S-sulfonate by high-performance liquid chromatography.

Abstract A method for simultaneous detection of picomole quantities of glutathione (GSH), glutathione disulfide (GSSG), glutathione S -sulfonate (GSSO 3 H), and cysteine S -sulfonate (CYSSO 3 H) by high-performance liquid chromatography has been developed. Compounds are separated by anion-exchange chromatography using a citric acid buffer system, and then derivatized postcolumn using o -phthalaldehyde with 2-mercaptoethanol, heated to 70°C, and detected by fluorescence. The compounds elute with retention times of 12.5 min for GSH, 27.5 min for CYSSO 3 H, 29.8 min for GSSG, and 33.0 minutes for GSSO 3 H, with detection limits of 10, 200, 10, and 50 pmol, respectively. Recoveries are 103% for GSH, 102% for GSSG, 100% for CYSSO 3 H, and 96% for GSSO 3 H. Determination of target compounds in cells is described.
Synthesis, reactions and structure of bromo(η5-diphenylphosphinylcyclopentadienyl)nickel(II) dimer

Abstract The reaction of diphenylphosphinylcyclopentadienylthallium (1) with NiBr2·2DME has produced Ni2(η5-C5H4PPh2)2Br2 (2) in quantitative yield. A reaction of 2 with methyl-lithium affords Ni2(η5-C5H4PPh2)2(CH3)2 (3) in high yield. Both 2·0.5CH2Cl2 and 3 have been characterized by means of single crystal X-ray diffraction studies and shown to be homobimetallic, with cyclic dimeric structures. Each ligand bridges two metal centers via P coordination to one and η5-coordination of the cyclopentadienyl moiety to a second Ni2+. Each nickel atom is thus formally five-coordinate with average bonding parameters of Ni–Centroid (Cp), Ni–P, and Ni–X of 1.760(5), 2.154(5), Br: 2.301(8) A (2) and 1.769(5), 2.113(5), CH3: 1.944(1) A (3). The P–Ni–X angles are compressed in 3 compared to 2 by an average of 4°.
All the Way with Gauss-Bonnet and the Sociology of Mathematics

I was stimulated to write this story by the discussion in The American Mathematical Monthly between Peter Hilton and Jean Pederson on the one hand and Branko Grunbaum and G. C. Shephard on the other hand [HP] [GS]. The discussion as well as my story involves the Euler-Poincare Number, alias the Euler Characteristic. The discussion centers on whether the Euler-Poincare Number should be discussed in a historical way without mentioning the vast and dramatic generalization and depth of understanding that this most interesting invariant has acquired in this century. My position in this discussion is that Topology should not be viewed as an advanced subject whose theorems and concepts should be avoided until graduate school. Rather it is the study of continuity, and thus underlies the most basic geometric results. In this paper I show how the basic concept of angle leads naturally to the basic topological ideas of degree of mapping and of the EulerPoincare Number. My stozy spans the history of mathematics. It concerns what may be the most widely known non-obvious theorem of mathematics and it contains the same stunning generalization that characterizes the recent history of the Euler-Poincare number. In fact, it concerns one of the most important and earliest of the applications of the Euler-Poincare number. It shows the fickleness of mathematical fame, it shows the unreasonable power of unreasonable points of view, and it shows how easy it is for mathematicians to miss and forget beautiful and important theorems as well as simple and revealing points of view. This is a history of the Gauss-Bonnet theorem as I see it. I am not a mathematical historian. I quote only secondary sources or first hand papers that I quickly scanned, and I did not conduct any thorough interviews. Nonetheless, I am writing this history because I have contributed the last sentence to it (for the moment). I especially want to acknowledge the help of Hans Samelson. His scholarship greatly altered the thrust of earlier versions of this paper. He discovered Satz VI. He informed me of many points in this history; about Gauss' work, Descartes work, and Hopf's work. And he was a student of Hopf who generalized the GaussBonnet theorem himself.
Delayed-type hypersensitivity reaction to the meta-cresol component of insulin.

Background Reactions to recombinant human insulin preparations occur at a rate of 2.4%. Although most have been traced to immunological reactions to the insulin, recent reports suggest that some adverse reactions can occur to the nonmedicinal excipients or preservatives of commercially available insulin preparations. Objectives To investigate a localized delayed cutaneous reaction to human insulin. Methods Intradermal and patch testing were performed on a patient to evaluate sensitivity to commercial human insulins, meta -cresol, and other sensitizers. Results Patch test results were positive to the meta -cresol preservative. Conclusions This is the first report, to our knowledge, of a reaction to meta -cresol in commercial preparations of insulin. This reaction should be considered in the differential diagnosis of adverse reactions to insulin injections.
Living by the Numbers

Quantitation of an article's worth by the impact of the journal in which it appears is a path to undermining scientific enterprise. Through a process analogous to rating medical care, rating journals can lead to loss of research effort in the most challenging questions. A paper should be evaluated on its own impact, not by some arbitrary score for the journal as a whole.
Employing topographical height map in colonic polyp measurement and false positive reduction

CT colonography (CTC) is an emerging minimally invasive technique for screening and diagnosing colon cancers. Computer aided detection (CAD) techniques can increase sensitivity and reduce false positives. Inspired by the way radiologists detect polyps via 3D virtual fly-through in CTC, we borrowed the idea from geographic information systems to employ topographical height map in colonic polyp measurement and false positive reduction. After a curvature based filtering and a 3D CT feature classifier, a height map is computed for each detection using a ray-casting algorithm. We design a concentric index to characterize the concentric pattern in polyp height map based on the fact that polyps are protrusions from the colon wall and round in shape. The height map is optimized through a multi-scale spiral spherical search to maximize the concentric index. We derive several topographic features from the map and compute texture features based on wavelet decomposition. We then send the features to a committee of support vector machines for classification. We have trained our method on 394 patients (71 polyps) and tested it on 792 patients (226 polyps). Results showed that we can achieve 95% sensitivity at 2.4 false positives per patient and the height map features can reduce false positives by more than 50%. We compute the polyp height and width measurements and correlate them with manual measurements. The Pearson correlations are 0.74 (p=0.11) and 0.75 (p=0.17) for height and width, respectively.
Open letter to the volcanology, geochemistry and petrology section

As incoming president-elect of this section, I welcome suggestions from members. Because of the strong overlap of interests with those of the Geological Society of America, Geochemical Society, Meteoritical Society, and Mineralogical Society of America, I am particularly interested in maintaining appropriate coordination. Ideas for themes of sessions at the annual meetings would be welcome, along with offers of help in organization. I am concerned about the high costs of meetings but suspect that there is no way of cutting costs except to go to a state university and use dormitory facilities. Any ideas about locations for meetings would be useful for discussion. There is considerable duplication of papers given at the Lunar and Planetary Science Conference and the American Geophysical Union meetings. Should there be discussion about combining the LPSC with the AGU Spring Meeting? Can research budgets continue to cover the approximately $1000 needed for two conferences? Is any member concerned about publications? Even in the best run organizations there can be administrative problems; do you have any concerns? If you would like to nominate anyone for an award, please send appropriate information. Thank you.
Partner time sharing at the Submillimeter Array

The Submillimeter Array (SMA) is an 8-element interferometer which operates in the 180-700 GHz range located atop Mauna Kea in Hawaii. It is a collaborative project between the Smithsonian Astrophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) and is funded by the Smithsonian Institution and the Academia Sinica. The University of Hawaii (UH) receives a fixed percentage of all time on the telescopes of Mauna Kea. As such, the observing time at the SMA is shared among these partners at the SAO:ASIAA:UH levels of 72:15:13. The nature of interferometric observing makes keeping track of these partner shares challenging. Since a typical successful interferometric observation could last anywhere from 3-10 hours for it to have sufficient uv-coverage, it does not necessarily make sense to divide the observing time up simply by counting hours. In this talk I will summarize the strategy devised at the SMA for keeping track of partner time shares as well as the tools used to make these numbers transparent to all affiliations.
Insight into the treatment of vulvar pain: a survey of clinicians.

Objective The purpose of this investigation was to determine practice patterns among clinicians who frequently treat patients with vulvar pain syndromes. Study design A cross-sectional survey was distributed to providers in the United States whose names were on a referral list of clinicians that care for women with vulvar pain (National Vulvodynia Association, Silver Springs, MD). The survey included 2 clinical vignettes. Clinicians were asked to report what treatments they would use to treat women with generalized vulvodynia and localized vulvodynia. Data were analyzed with descriptive statistics. A comparison of categoric data was accomplished with the Fisher's exact test. Results Surveys were mailed to 327 providers; 167 completed surveys were returned, for an overall response rate of 51%. The most commonly used treatment for vulvodynia was tricyclic antidepressants. There was no difference in the use of physical therapy, estrogens, injected or topical steroids, interferon, or laser therapy to treat generalized and localized vulvodynia. Respondents were more likely to use tricyclic antidepressants ( P P P P P =.007) for the clinical scenario that represented generalized vulvodynia than they were for the scenario that represented localized vulvodynia. Most clinicians reported screening for vaginal infections, and many clinicians perform colposcopy and/or vulvar biopsy. Respondents recommend a variety of lifestyle modifications in the treatment of vulvodynia. Conclusion Clinicians use a wide variety of treatments for vulvar pain and use different therapies for variants of vulvodynia.
Fraternity Membership and Sexual Aggression: An Examination of Mediators of the Association

Abstract Objective: This prospective study examined attitudes (ie, hostility toward women, acceptance of rape myths), peer influences (ie, peer pressure to have sex, peer approval of forced sex), and risky behaviors (ie, high-risk alcohol use, number of sexual partners) as possible mediators of the association between fraternity membership and sexual aggression. Participants: The sample included 424 males recruited as freshmen from a large state university in the southeastern United States. Methods: Respondents completed survey measures in their first, second, and third years of enrollment at the university. Results: Path analyses revealed that the prospective effect of fraternity membership on sexual aggression was mediated by high-risk alcohol use. Conclusions: The findings indicate that high-risk alcohol use accounts for much of the association between fraternity membership and sexual aggression.
The effect of gold on platinum oxidation in homogeneous Au–Pt electrocatalysts

Abstract Oxidation of Au–Pt thin films was carried out in ambient air at room temperature and characterized by X-ray photoelectron spectroscopy. The homogeneous films were prepared by RF co-sputtering with concentrations varying from Au 9 Pt 91 to Au 89 Pt 11 and compared to pure Pt and Au thin films. Spectral deconvolution of the Au 4 f and Pt 4 f core levels revealed linear peak shifts for both the Au–Au and Pt–Pt bonding components as a function of alloy mixture and metallic component peak asymmetry that remained constant for all alloy stoichiometries. The predominant oxidation products were PtO and PtO 2 and were characterized by stable core level binding energies for all films. A gradual decline in the Pt–O x products and corresponding levels of elemental oxygen was observed with increasing Au content but was similar in proportion to the metallic Pt components. Based on these results, variations in Pt oxide phases and/or concentration do not appear to contribute to enhanced electrocatalytic activity for oxygen reduction observed for the intermediate alloy stoichiometries.
Human Cep192 Is Required for Mitotic Centrosome and Spindle Assembly

As cells enter mitosis, centrosomes dramatically increase in size and ability to nucleate microtubules. This process, termed centrosome maturation, is driven by the accumulation and activation of gamma-tubulin and other proteins that form the pericentriolar material on centrosomes during G2/prophase. Here, we show that the human centrosomal protein, Cep192 (centrosomal protein of 192 kDa), is an essential component of the maturation machinery. Specifically, we have found that siRNA depletion of Cep192 results in a complete loss of functional centrosomes in mitotic but not interphase cells. In mitotic cells lacking Cep192, microtubules become organized around chromosomes but rarely acquire stable bipolar configurations. These cells contain normal numbers of centrioles but cannot assemble gamma-tubulin, pericentrin, or other pericentriolar proteins into an organized PCM. Alternatively, overexpression of Cep192 results in the formation of multiple, extracentriolar foci of gamma-tubulin and pericentrin. Together, our findings support the hypothesis that Cep192 stimulates the formation of the scaffolding upon which gamma-tubulin ring complexes and other proteins involved in microtubule nucleation and spindle assembly become functional during mitosis.
Fast-neutron flux measurement with a lithium-drifted germanium detector

Abstract The use of lithium-drifted germanium detectors for fast-neutron flux measurement has been investigated. The proposed detection mechanism is observation of the internal conversion electrons emitted during the de-excitation of the 691 KeV 0 + state in 72 Ge following excitation via fast-neutron scattering. A 4.0 cm 3 (approx.) planar Ge(Li) detector has been calibrated for neutron flux measurements over the energy range E n = 700−5000 keV. The absolute efficiency for this detector (ratio of neutrons detected to neutrons incident on the detector) has been determined to be (8.2±0.5) × 10 −4 at E n = 1500 keV which is about 10% of the full-energy peak efficiency for 1332 keV 60 Co gamma rays. Cross-sections for excitation of the 691 keV 0 + state in 72 Ge via neutron scattering have been extracted from the measured efficiency function. These cross-sections can be used to calculate efficiency functions for other detectors. Insensitivity to thermal neutrons, gamma-ray discrimination capability and stability are among the desirable features of this type of fast-neutron detector. Submicrosecond timing is not possible because of the isomeric nature of the 691 keV 0 + state in 72 Ge. While Ge(Li) detectors suffer radiation damage from fast-neutron bombardment, the detector used for these measurements withstood an integrated dose exceeding 10 10 neutrons/cm 2 without serious deterioration of its performance.
Extending pre-silicon delay models for post-silicon tasks: Validation, diagnosis, delay testing, and speed binning

All post-silicon tasks - validation, diagnosis, delay testing, and speed-binning - must be carried out by applying vectors to actual chips, and capturing and analyzing responses. Yet, vectors used must be generated and analyzed using pre-silicon models of the circuit. Three comprehensive industrial studies demonstrate that existing approaches for generating such vectors are inadequate, and one major weakness is that existing delay models either do not capture process variations or do not capture advanced delay phenomenon that significantly affect delays. Hence, existing models underestimate the worst case delay leading to selection of non-critical paths and generation of vectors that do not invoke worst case delays. In this paper, we propose a simple notion of bounding approximation and show how it can extend any existing delay model to also capture process variations and to eliminate any underestimation. The main question we investigate is how best to use this approach to select paths and generate or evaluate vectors for post silicon tasks. In particular, we study whether it is better to use this approach to bound simple pin-to-pin delay models or more advanced delay models. At the level of timing analysis, bounded versions of pin-to-pin delay models have lower run-time complexity but looser bounds. However, we conduct path selection for delay testing and vector generation for delay validation and show that bounded versions of more advanced delay models are significantly more efficient in terms of validation cost and runtime complexity.
Electrophysiology of Connection Current Spikes

Connection to a 60-Hz or other voltage source can result in cardiac dysrhythmias, a startle reaction, muscle contractions, and a variety of other physiological responses. Such responses can lead to injury, especially if significant ventricular cardiac dysrhythmias occur, or if a person is working at some height above ground and falls as a result of a musculoskeletal response. Physiological reactions are known to relate to intensity and duration of current exposure. The connection current that flows is a function of the applied voltage at the instant of connection, and the electrical impedance encountered by the voltage source in contact with the skin or other body tissues. In this article we describe a rarely investigated phenomenon, namely a contact, or connection, current spike that is many times higher than the steady-state current. This current spike occurs when an electrical connection is made at a non-zero voltage time in a sine wave or other waveform. Such current spikes may occur when electronic or manual switching or connecting of conductors occurs in electronic instrumentation connected to a patient. These findings are relevant to medical devices and instrumentation and to electrical safety in general.
Accurate Lattice Constant and Mismatch Measurements of SiC Heterostructures by X-Ray Multiple-Order Reflections

High-resolution X-ray diffraction (HRXRD) combined with other diffraction techniques is applied to characterize 3C SiC epilayers hoteroepitaxially grown on atomically flat mesas on 4H and 6H SiC substrates. Small-beam rocking curve scan and reciprocal mapping show extremely high crystalline perfection and homogeneity of the ideally grown 3C-SiC epilayers. Accurate lattice measurements based on X-ray multiple-order reflections reveal that: 1) no misorientation between the (0001) lattice planes across the 4H/3C or 6H/3C interface is detected, confirming the 2D nucleation mechanism of the 3C epilayer from a flat coherent interface; 2) in-plane substrate/epilayer lattice mismatch always exists, but the 3C epilayers do not correspond to a completely relaxed cubic structure, indicating that the epilayers are partially strained; 3) lattice mismatch varies for different regions, implying a complicated strain relaxation mechanism of 3C epilayers on various mesas.
An investigation into microstructure and mechanical properties of cold sprayed 7075 Al deposition

Abstract Cold spray deposition is well known to produce a highly deformed microstructure with large strain gradients across the individual particles composing the deposited layer. This study investigates the relationship between the as-deposited cold spray microstructure and the resulting local and coating-scale mechanical properties of 7075 aluminum powder deposited onto wrought 7075 aluminum substrates via high pressure cold spray. Local mechanical property variations were probed using nanoindentation and correlated with microstructural characterization conducted via various microscopy techniques. 7075 Aluminum powder particles experienced high deformation rates during impact, resulting in local microstructural variations, specifically grain size and dislocation densities, between particle interfaces and their interiors. Consequently, an average 0.5 GPa increase in nanohardness was observed in particle interface regions. This increase in hardness was concluded to be primarily the result of grain refinement promoted by local dynamic recrystallization, rather than from an increase in local dislocation density causing strain hardening behavior. Examination of the coating revealed a decrease in hardness and an increase in local grain size with increasing distance from the substrate. The effects of these microstructural variations on the quality of the deposition were also evaluated by tensile pull-off and three lug shear testing.
Feedback Effects in Combined Fast-Scan Cyclic Voltammetry-Scanning Electrochemical Microscopy

Fast-scan cyclic voltammetry at scan rates between 5 and 1000 V s-1 was performed at the tip of a scanning electrochemical microscope immersed in a solution of redox mediator. The effect of conducting and insulating substrates on the voltammetric signal was investigated as a function of scan rate and tip−substrate distance. It was found that diffusional interactions between the tip and the substrate are greatest at lower scan rates and on the reverse sweep of the voltammogram. At the fastest scan rates used, the tip could be brought to with 1 μm of the substrate without appreciable perturbation of the voltammogram. By selecting scan rates and tip−substrate distances such that feedback effects were negligible, it was possible to image the diffusion layer of a 10 μm Pt substrate electrode. With the tip placed 1 μm above a biological cell, tip−substrate diffusional interactions were greatly diminished at a scan rate of 100 V s-1 and absent at a scan rate of 1000 V s-1. These results suggest conditions can be...
Ionization of atoms by the spatial gradient of the pondermotive potential in a focused laser beam

Ionization of atoms by the spatial gradient of the pondermotive potential in a focused laser beam is investigated. Rydberg ions, formed during the interaction of noble gas atoms with an intense laser pulse, are used to probe the gradient field. Rydberg ion species with higher ionization potentials are produced at locations where the gradient field is largest. The measured Rydberg ion yields differ dramatically from estimates that ignore gradient-field ionization, but are in good agreement with predictions that include the effect.
Modeling Incident-Related Routing Decisions by Using a Nested Logit Structure

Unusual congestion that could be caused by an incident or other traffic problems is a major source of delay for drivers in urban areas. Real-time traffic information, the building block for advanced traveler information systems (ATIS), has a promising potential for alleviating such congestion by encouraging and assisting drivers to divert to less congested routes. Traffic information is envisioned to help more informed routing decisions in case of incident-related congestion. Drivers' routing decisions made when they are faced with such unusual congestion are investigated. The factors that influence these decisions are explored, including the effect of traffic information. A nested logit modeling structure is introduced. This model proved that the nested logit approach is superior than the simple multinomial logit in modeling the choice in cases of incident-related congestion. The model also showed that the decisions not to divert from the usual route and to divert but only around the location of the prob...
Early Germinative Ideas on the Origins of Infectious Disease

In his Pathways of Discovery essay “Infectious history” (14 Apr., p. [287][1]), Joshua Lederberg presents a perceptive and insightful overview of the historical background and progress in our understanding of infectious diseases that affect humans and animals. However, in view of the importance
Revision of the Career Maturity Inventory: The Adaptability Form

Initially administered in 1961, the Career Maturity Inventory (CMI) was the first paper-and-pencil measure of vocational development. The present research revised the CMI to reestablish its usefuln...
Documenting and Assessing the Role of Community Colleges in Developing Human Capital

The 21st century community college is an institution that espouses the values of open-access and high quality education. The literature is filled with research that documents the extent to which these institutions contribute to society and to human capital development. The purpose of this article is three-fold: First, to apply a human capital framework to the community college context; second, to describe efforts by several states to document and assess their community colleges' contributions to human capital development; and third, to raise research and policy issues related to improving assessment of that role. The article concludes by addressing future research and policy implications.
SHEAR STRENGTH OF HDPE GEOMEMBRANE/GEOSYNTHETIC CLAY LINER INTERFACES

A study of interface shear strengths between smooth and textured high density polyethylene (HDPE) geomembranes (GMs) and a woven/nonwoven needle-punched geosynthetic clay liner (GCL) is presented. Tests were performed using a large direct shear machine capable of measuring peak and large displacement (200 mm) shear strengths. The failure surface was located at the GM/GCL interface for all tests conducted, corresponding to a normal stress range of 1-486 kPa. Small positive pore pressures were measured for all interfaces at peak shear strength. Thus, the practice of preparing failure envelopes using total normal stress, instead of effective normal stress, appears to be conservative. Interface shear strengths for textured GMs placed against the nonwoven side of the GCL were higher than those corresponding to the woven side. By comparison, differences in peak shear strength for laminated and coextruded GM interfaces were relatively less. Limited tests showed that peak and large displacement shear strengths were independent of displacement rate and dependent on the shear direction of the GM. The quantity of extruded bentonite at the interfaces generally increased with normal stress and was less for nonwoven geotextile interfaces than for woven geotextile interfaces. Implications of the findings to the testing of GM/GCL interfaces and the characterization of GM/GCL interface shear strength are discussed.
A Neutralizing Monoclonal IgG1 Antibody of Platelet-Activating Factor Acetylhydrolase SsE Protects Mice against Lethal Subcutaneous Group A Streptococcus Infection

Group A Streptococcus (GAS) can cause life-threatening invasive infections, including necrotizing fasciitis. There are no effective treatments for severe invasive GAS infections. The platelet-activating factor (PAF) acetylhydrolase SsE produced by GAS is required for invasive GAS to evade innate immune responses and to invade soft tissues. This study determined whether the enzymatic activity of SsE is critical for its function in GAS skin invasion and inhibition of neutrophil recruitment and whether SsE is a viable target for immunotherapy for severe invasive GAS infections. An isogenic derivative of M1T1 strain MGAS5005 producing SsE with an S178A substitution (SsE(S178A)), an enzymatically inactive SsE mutant protein, was generated. This strain induced higher levels of neutrophil infiltration and caused smaller lesions than MGAS5005 in subcutaneous infections of mice. This phenotype is similar to that of MGAS5005 sse deletion mutants, indicating that the enzymatic activity of SsE is critical for its function. An anti-SsE IgG1 monoclonal antibody (MAb), 2B11, neutralized the PAF acetylhydrolase activity of SsE. Passive immunization with 2B11 increased neutrophil infiltration, reduced skin invasion, and protected mice against MGAS5005 infection. However, 2B11 did not protect mice when it was administered after MGAS5005 inoculation. MGAS5005 induced vascular effusion at infection sites at early hours after GAS inoculation, suggesting that 2B11 did not always have access to infection sites. Thus, the enzymatic activity of SsE mediates its function, and SsE has the potential to be included in a vaccine but is not a therapeutic target. An effective MAb-based immunotherapy for severe invasive GAS infections may need to target virulence factors that are critical for systemic survival of GAS.
Identification of performance limiting electrode using asymmetric cell configuration in vanadium redox flow batteries

Abstract In this study, the performance of a vanadium redox flow battery (VRFB) is investigated using asymmetric electrode configurations with raw and functionalized (i.e., acid-treated and heat-treated) electrodes. The use of heat-treated electrodes in both half-cells is chosen as the baseline case for comparison, as this configuration shows the best performance. When the positive electrode in the baseline case is replaced with a raw or acid-treated electrode, the voltage efficiency is found to be comparable to that of the baseline case. However, in the case where the negative electrode in the baseline case is replaced with a raw or acid-treated electrode, a significantly lower efficiency is observed, suggesting that the negative half-cell reactions limit the performance of a VRFB. To further investigate this observation, an additional analysis is performed using cyclic voltammetry. The reaction kinetics data suggests that the poor performance of the negative half-cell is not due to the slow kinetics, but rather stems from the fact that the reduction reaction in the negative half-cell occurs at a potential that is very close to the onset of hydrogen evolution. The formation of hydrogen gas bubbles blocks the reaction sites and suppresses the favorable effects of functionalization in the negative half-cell.
Optimization of multiple quantum well structures for waveguide electroabsorption modulators

A systematic approach for optimizing the performance of a multiple quantum well electroabsorption waveguide modulator is presented. The primary criterion of the modulator performance for digital and analog applications is taken to be the change of transmission Delta T at a given applied electric field. The design variables used to maximize Delta T include the device length (L), as well as the quantum well width and composition which determine the electroabsorption ( Delta alpha ) and the residual absorption ( alpha /sub 0/) at a given photon wavelength. Within the range of Delta T that can satisfy the system requirement, the L is then minimized to maximize the bandwidth. The effect of the guided wave index profile and the electrical properties of the p-i-n structure on the bandwidth and the drive voltage requirement is discussed. >
Interspecies Chimeric Sperm Lysins Identify Regions Mediating Species-Specific Recognition of the Abalone Egg Vitelline Envelope

Abstract Abalone sperm lysin is a nonenzymatic, 16-kDa protein that creates a hole in the egg vitelline envelope (VE) through which the sperm swims to fuse with the egg. The dissolution of isolated VE by lysin is species specific. Interspecies comparisons show that the most divergent region of lysin is the N-terminal segment of residues 1–12 which is always species-unique. The C-terminus and three internal segments are moderately variable between species, but not species unique. Analysis of nucleotide substitutions shows that lysin evolves rapidly by positive Darwinian selection, suggesting that there is adaptive value in altering its amino acid sequence. The results reported here, in which segments of lysin were exchanged between two species, prove by direct experimentation that the interspecies variable termini play major roles in the species-specific recognition between sperm lysin and the egg VE.
Fabrication and properties of composite holograms recorded in DMP-128 photopolymer

Special features of the photopolymer system DMP128 can be exploited to form composites comprising a supporting matrix derived from the photopolymer and a dispersed second phase. Examples of two composite types are described here; composites with a nematic liquid crystal and composites used as waveguides. The diffraction efficiency of holograms containing the liquid crystal can be rapidly changed by applying an electric field. Periodic structures can easily be incorporated in the waveguide composites.
Coherence imaging for early cancer detection

We have developed multiple spectroscopic coherence imaging methods to assess pre-cancerous states by isolating scattering signatures from specific tissue locations. We describe the basis, validation and development of the approaches and recent clinical results.
New concepts on the role of ubiquinone in the mitochondrial respiratory chain

Ubiquinone participates in the oxidation-reduction reactions of the mitochondrial respiratory chain. In addition, this molecule possesses the necessary properties to function as a hydrogen carrier, thereby stoichiometrically coupling proton translocation to respiration by a direct chemiosmotic mechanism. This review discusses recent experimental evidence and new concepts relating to ubiquinone function in the mitochondrial respiratory chain. Emphasis is placed on possible protonmotive mechanisms of ubiquinone function, recent evidence implicating stable forms of ubisemiquinone in the respiratory chain, and properties of the ubiquinone molecule which may relate to its biological function.
Geomorphic controls on mercury accumulation in soils from a historically mined watershed, Central California Coast Range, USA

Abstract Historic Hg mining in the Cache Creek watershed in the Central California Coast Range has contributed to the downstream transport of Hg to the San Francisco Bay-Delta. Different aspects of Hg mobilization in soils, including pedogenesis, fluvial redistribution of sediment, volatilization and eolian transport were considered. The greatest soil concentrations (>30 mg Hg kg −1 ) in Cache Creek are associated with mineralized serpentinite, the host rock for Hg deposits. Upland soils with non-mineralized serpentine and sedimentary parent material also had elevated concentrations (0.9–3.7 mg Hg kg −1 ) relative to the average concentration in the region and throughout the conterminous United States (0.06 mg kg −1 ). Erosion of soil and destabilized rock and mobilization of tailings and calcines into surrounding streams have contributed to Hg-rich alluvial soil forming in wetlands and floodplains. The concentration of Hg in floodplain sediment shows sediment dispersion from low-order catchments (5.6–9.6 mg Hg kg −1 in Sulphur Creek; 0.5–61 mg Hg kg −1 in Davis Creek) to Cache Creek (0.1–0.4 mg Hg kg −1 ). These sediments, deposited onto the floodplain during high-flow storm events, yield elevated Hg concentrations (0.2–55 mg Hg kg −1 ) in alluvial soils in upland watersheds. Alluvial soils within the Cache Creek watershed accumulate Hg from upstream mining areas, with concentrations between 0.06 and 0.22 mg Hg kg −1 measured in soils ∼90 km downstream from Hg mining areas. Alluvial soils have accumulated Hg released through historic mining activities, remobilizing this Hg to streams as the soils erode.
Career Ladders and the Origins of Brokerage in Intra-organizational Networks

While we have ample empirical evidence linking brokerage in intraorganizational social networks to a variety of benefits, we know less about its origins. In this study, I examine the role of individual career history in creating brokerage. I hypothesize that individuals who follow career trajectories that are atypical in the organization will show greater propensity to interact across organizational and social distance than equally mobile individuals whose careers followed more conventional paths. Furthermore, I argue that bridging ties result from two social-capital based mechanisms – links with former co-workers and with “friends of friends” – as well as from human capital. Career history is recorded longitudinally for 30,000 employees in a large information technology firm over seven years; network position is measured using a unique data set of over 150 million electronic mail messages. Empirical results support the hypotheses that diverse – and especially atypical – careers have a causal effect on br...
A COMPARATIVE STUDY OF THE EFFECTS OF MALE AND FEMALE SEX HORMONES ON THE HUMAN VAGINAL SMEAR

Io mg. of testosterone and 1000 i.u. of estradiol, the vaginal smear was per′sistently atrophic in appearance, but when the estradiol dosage was raised to 5000 i.u. the smear assumed a follicular character. However, adjusting the ratio to 25 mg. and 5000 i.u. respectively resulted in a prompt return of the atrophic type of smear. Thi was maintained in spite of a subsequent eleva′tion of estradiol to 10,000 i.u. These findings would seem to indicate some degree of intersexual hormone neutralization. Th most attractive hypothesis to explain the action of male hormone in the female is (as Moore originally postulated) that it decreases the pituitary output of gonadotropic hormone in the same manner as estrin, thus affecting the ovary and secondary sex organs indirectly. Such a concept is well sub′stantiated by the reports of Salmon (16) and Papanicolaou (18).
MDCT has the potential to predict percutaneous coronary intervention outcome in swine model: microscopic validation:

BackgroundVolumes and sizes of dislodged coronary microemboli vary during PCI so their effects at the left ventricular (LV) and cellular levels cannot be quantified. Furthermore, biopsy for tissue characterization is not an option in PCI patients.PurposeTo characterize and validate microinfarct size, LAD territory where microinfarct were found using multidetector computed tomography (MDCT), histochemical staining and microscopy as a function of microemboli volumes and to scale the effects of microemboli volumes on LV function.Material and MethodsUnder X-ray guidance, a 3F catheter was inserted into LAD coronary artery of 14 pigs for delivering 16 mm3 or 32 mm3 of 40-120 μm microemboli. MDCT imaging/histochemical staining/ microscopy were performed 3 days later and used to characterize regional and global structural and functional changes in LV by threshold/planimetric methods.ResultsMDCT and ex-vivo methods were able to quantify microinfarct size and LAD territory where microinfarct was found as a functio...
The Value of Synergy

Many acquisitions and some large strategic investments are often justified with the argument that they will create synergy. In this paper, we consider the various sources of synergy and categorize them into operating and financial synergies. We then examine how best to value synergy in any investment and how sensitive this value is to different assumptions. We also look at how this synergy value should be divided between the parties (or companies) involved in the investment. We conclude with an empirical examination of how much synergy is actually created in corporate mergers, and how much is paid. Synergy, we conclude, is so seldom delivered in acquisitions because it is incorrectly valued, inadequately planned for and much more difficult to create in practice than it is to compute on paper.