Development of the Murine Periodontium. I. Role of Basement Membrane in Formation of a Mineralized Tissue on the Developing Root Dentin Surface

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141263/1/jper0095.pd

A Neuroergonomics Approach to Mental Workload, Engagement and Human Performance

The assessment and prediction of cognitive performance is a key issue for any discipline concerned with human operators in the context of safety-critical behavior. Most of the research has focused on the measurement of mental workload but this construct remains difficult to operationalize despite decades of research on the topic. Recent advances in Neuroergonomics have expanded our understanding of neurocognitive processes across different operational domains. We provide a framework to disentangle those neural mechanisms that underpin the relationship between task demand, arousal, mental workload and human performance. This approach advocates targeting those specific mental states that precede a reduction of performance efficacy. A number of undesirable neurocognitive states (mind wandering, effort withdrawal, perseveration, inattentional phenomena) are identified and mapped within a two-dimensional conceptual space encompassing task engagement and arousal. We argue that monitoring the prefrontal cortex and its deactivation can index a generic shift from a nominal operational state to an impaired one where performance is likely to degrade. Neurophysiological, physiological and behavioral markers that specifically account for these states are identified. We then propose a typology of neuroadaptive countermeasures to mitigate these undesirable mental states

Insertional Inactivation of Binding Determinants of Streptococcus Crista CC5A Using Tn916

Intermicrobial binding plays an important role in the ecology of the oral cavity because itrepresents one mechanism by which specific bacteria colonize dental plaque. The formation of“corncobs”, a morphologically distinct microbial unit composed of Streptococcus crista andFusobacterium nucleatum, is a highly specific binding interaction that depends on the presence ofpolar tufts of fimbriae on the streptococci. We have used a genetic approach to examine the role ofstreptococcal cell surface components involved in the binding of S. crista to F. nucleatum. Suchbinding may be an important component of corncob formation. A method for the genetictransformation of S. crista was used to transfer the broad host range transposon, Tn916, into thebacteria. Cells were grown to early log phase in brain heart infusion broth containing 10% fetalcalf serum. The competent cells were mixed with purified DNA from pDL916, a plasmidconstruct consisting of Tn916 and the streptococcal/Escherichia coli shuttle vector pDL278. Over300 transformants were screened for a reduction in binding to F. nucleatum. Five of thetransformants showed a change in binding ranging from 59% to 29% of the positive controlvalues. Southern blots revealed that the binding-deficient transformants contained the Tn916element integrated into one of 4 different sites in the chromosome. The transposon, integrated into4 different sites, appeared to be stable in the absence of selective pressure. Based on thesefindings, it appears that some strains of S. crista are naturally competent and that insertionalinactivation methods can be used to facilitate the study of binding receptors in this group of oralstreptococci

Accounting Program Assessment: Exit Interviews of Graduating Seniors

Exit interviews of university graduating seniors have been used to a very limited extent when evaluating academic programs.  It is our belief that developing and implementing an exit interview plan stimulates faculty dialog and improves ongoing feedback for department program assessment.  From 2001 to 2007, the Accounting Department at Towson University has conducted exit interviews with all graduating seniors as part of the annual internal department assessment activities.  The exit interviews have served to assist the Department of Accounting in evaluating its performance as judged by the students served.  The positive comments assist to reinforce the quality activities of the department, while the negative comments permit the department to become aware of areas of perceived weakness that are in need of improvement.   By receiving annual feedback from a valuable, relevant source, the department is able to continuously monitor, adjust, and improve its performance

Linear & Nonl. optics checks diring LHC injection tests

In early LHC commissioning, linear and “higher-order” polarity checks were performed for one octant per beam, by launching suitable free betatron oscillations and then inverting a magnet-circuit polarity or strength. Circuits tested included trim quadrupoles, skew quadrupoles, lattice sextupoles, sextupole spool-pieces, Landau octupoles, and skew sextupoles. A nonzero momentum offset was introduced to enhance the measurement quality. The lowintensity single-pass measurements proved sufficiently sensitive to verify the polarity and the amplitude of (almost) all circuits under investigation, as well as the alignment of some individual trim quadrupoles. A systematic polarity inversion detected by this measurement helped to pin down the origin of observed dispersion errors. Later, the periodic “ring dispersion” was reconstructed from the full first-turn trajectory of an injected off-momentum beam, by removing, at each location, the large incoming dispersion mismatch, forward-propagated via the optics model. Various combinations of inverted trim quadrupoles were considered in this model until reaching a good agreement of reconstructed dispersion and prediction

Large-scale variations in ozone and polar stratospheric clouds measured with airborne lidar during formation of the 1987 ozone hole over Antarctica

A joint field experiment between NASA and NOAA was conducted during August to September 1987 to obtain in situ and remote measurements of key gases and aerosols from aircraft platforms during the formation of the ozone (O3) hole over Antarctica. The ER-2 (advanced U-2) and DC-8 aircraft from the NASA Ames Research Center were used in this field experiment. The NASA Langley Research Center's airborne differential absorption lidar (DIAL) system was operated from the DC-8 to obtain profiles of O3 and polar stratospheric clouds in the lower stratosphere during long-range flights over Antarctica from August 28 to September 29, 1987. The airborne DIAL system was configured to transmit simultaneously four laser wavelengths (301, 311, 622, and 1064 nm) above the DC-8 for DIAL measurements of O3 profiles between 11 to 20 km ASL (geometric altitude above sea level) and multiple wavelength aerosol backscatter measurements between 11 to 24 km ASL. A total of 13 DC-8 flights were made over Antarctica with 2 flights reaching the South Pole. Polar stratospheric clouds (PSC's) were detected in multiple thin layers in the 11 to 21 km ASL altitude range with each layer having a typical thickness of less than 1 km. Two types of PSC's were found based on aerosol backscattering ratios: predominantly water ice clouds (type 2) and clouds with scattering characteristics consistent with binary solid nitric acid/water clouds (type 1). Large-scale cross sections of O3 distributions were obtained. The data provides additional information about a potentially important transport mechanism that may influence the O3 budget inside the vortex. There is also some evidence that strong low pressure systems in the troposphere are associated with regions of lower stratospheric O3. This paper discusses the spatial and temporal variations of O3 inside and outside the polar vortex region during the development of the O3 hole and relates these data to other measurements obtained during this field experiment

Racism and anti-racism in Europe: a critical analysis of concepts and frameworks

The targets and expressions of racism vary across Europe. This article discusses the relevance of different descriptions and analyses of racism despite the different terms used in different countries such as ‘ethnic minority’, ‘foreigner’ or ‘black’ and different interpretations of which differences matter. It shows the significance of a cross-national European perspective on racism. There are important convergences across European countries in the discourses and practices of racism, particularly the distinction between ‘useful’ and ‘abusive’ migrants. A cross-European perspective can be an important inspiration for anti-racist struggles

Heterogeneous processes: Laboratory, field, and modeling studies

The efficiencies of chemical families such as ClO(x) and NO(x) for altering the total abundance and distribution of stratospheric ozone are controlled by a partitioning between reactive (active) and nonreactive (reservoir) compounds within each family. Gas phase thermodynamics, photochemistry, and kinetics would dictate, for example, that only about 1 percent of the chlorine resident in the lower stratosphere would be in the form of active Cl or ClO, the remainder existing in the reservoir compounds HCl and ClONO2. The consistency of this picture was recently challenged by the recognition that important chemical transformations take place on polar regions: the Airborne Antarctic Ozone Experiment (AAOE) and the Airborne Arctic Stratospheric Expedition (AASA). Following the discovery of the Antarctic ozone hole, Solomon et al. suggested that the heterogeneous chemical reaction: ClONO2(g)+HCl(s) yields Cl2(g)+HNO3(s) could play a key role in converting chlorine from inactive forms into a species (Cl2) that would rapidly dissociate in sunlight to liberate atomic chlorine and initiate ozone depletion. The symbols (s) and (g) denote solid phase, or adsorbed onto a solid surface, and gas phase, respectively, and represent the approach by which such a reaction is modeled rather than the microscopic details of the reaction. The reaction was expected to be most important at altitudes where PSC's were most prevalent (10 to 25 km), thereby extending the altitude range over which chlorine compounds can efficiently destroy ozone from the 35 to 45 km region (where concentrations of active chlorine are usually highest) to lower altitudes where the ozone concentration is at its peak. This chapter will briefly review the current state of knowledge of heterogeneous processes in the stratosphere, emphasizing those results obtained since the World Meteorological Organization (WMO) conference. Sections are included on laboratory investigations of heterogeneous reactions, the characteristics and climatology of PSC's, stratospheric sulfate aerosols, and evidence of heterogeneous chemical processing

The Efficacy of Vaginal Clindamycin for the Treatment of Abnormal Genital Tract Flora in Pregnancy

Objective: To assess the efficacy of 2% clindamycin vaginal cream (CVC) to treat bacterial vaginosis (BV) in pregnancy. Methods: A prospective, randomized, double-blind, placebo-controlled, tricenter study. Four hundred and four women with BV on Gram stain at their first antenatal clinic visit were randomized to receive a 3-day course of 2% CVC or placebo. The outcome was assessed using an intention to treat analysis at 3 weeks and 6 weeks post-treatment according to three different diagnostic methods based on five criteria (Gram stain and all four elements of clinical composite criteria: vaginal discharge, abnormal vaginal pH, clue cells, amine odor), three criteria (vaginal pH, clue cells, amine odor) or two criteria (clue cells and amine odor) to reflect stringency of diagnosis, historical precedence and government agency recommendations respectively. Results: Using five diagnostic criteria, 18% of CVC patients were cured and 70.8% either cured and/or improved compared to 1.6% and 12% of placebo patients respectively (p < 0.0001). Using three diagnostic criteria, 44.8% of CVC patients were cured and 77.3% were either cured and/or improved compared to 9.3% and 28.8% of placebo patients respectively (p < 0.0001). Using two diagnostic criteria, 75.0% of CVC patients were cured compared to 18.0% of placebo patients (p < 0.0001). Recurrence rates in those CVC patients successfully treated were approximately 6% at 6 weeks post baseline and 10% at 28 to 34 weeks gestation. Conclusions: A 3-day course of CVC appears to be well tolerated by the mother and statistically significantly more efficacious than placebo in the treatment of BV during the second trimester of pregnancy

Dispersion engineered As2S3 planar waveguides for broadband four-wave mixing based wavelength conversion of 40 Gb/s signals

We demonstrate broadband wavelength conversion of a 40 Gb/s return-to-zero signal using four-wave-mixing (FWM) in a dispersion engineered chalcogenide glass waveguide. The 6 cm long planar rib waveguide 2 μm wide was fabricated in a 0.87 μm thick film etched 350nm deep to correspond to a design where waveguide dispersion offsets the material leading to near-zero dispersion in the C-band and broadband phase matched FWM. The reduced dimensions also enhance the nonlinear coefficient to 9800 W-1km-1 at 1550 nm enabling broadband conversion in a shorter device. In this work, we demonstrate 80 nm wavelength conversions with 1.65 dB of power penalty at a bit-error rate of 10-9. Spectral measurements and simulations indicate extended broadband operation is possible