Activation of toll-like receptor 2 through TLR2-LRR binding synthetic peptides

Bacterial sepsis and systemic inflammatory immune responses continue to be major causes of illness and death despite extensive research into the development of antimicrobial agents. There is a need for novel therapeutic reagents designed to modulate these responses. Toll-like receptor 2 plays a key role in the development of innate and adaptive immune responses to microbial products that interact with the receptor\u27s extracellular leucine-rich repeat ligand-binding domain. In a preliminary study, five peptides were synthesized that bound to the leucine-rich repeat region of Toll-like receptor 2 (TLR2). We tested the hypothesis that the novel TLR 2 leucine rich repeat binding peptides affects TLR2-mediated immune function by examining the ability of the five peptides to induce the maturation of bone marrow derived-dendritic cells in vitro. The dendritic cells were cultured in the presence of the peptides and maturation was determined through flow cytometry and cytokine analysis. We discovered that dendritic cells produced interleukin-6 to the JT1 leucine-rich repeat binding peptide. Some activation of the MHC class II dendritic cell maturation marker was observed in response to peptide JT1. Our results indicate that the JT1 synthetic toll-like receptor 2 leucine rich repeat binding peptide induces maturation of bone marrow derived dendritic cells in vitro

The perception of second-order motion

In this thesis the notion of an independent non-linear channel for the perception of second- order motion is investigated. An examination of speed discrimination thresholds for first- and second-order bars and edges showed no differences in the patterns of response over changes in the temporal and spatial parameters of the stimuli. The higher thresholds for second-order stimuli may be accounted for by appealing to the properties of their noise carriers. In a study of the direction of motion in reversed-phi stimuli, it was shown that luminance and contrast defined stimuli could elicit both forwards and reversed motion. The forwards motion in the contrast defined stimulus cannot be explained by the operation of a first- or second-order channel. Perception of motion direction in the contrast defined stimulus was dependent upon the characteristics of the noise carrier. Similar dependencies were observed when noise was added to the first-order stimulus. When the effect of carrier is taken into account, both types of stimulus show similar patterns of response over spatial and temporal frequency. Modulation depth tuning curves for the detection of motion direction in stimuli where motion was defined by contrast and luminance microstructure were also investigated. Luminance microstructure can affect perceived contrast in contrast defined motion and also in static noise pattems. This implies that some early non-linearity exists in the human visual system. The filtering and rectification approach to recovery of the second-order motion should be highly effecfive at recovering the modulant. However, an estimate of the size of the non-linearity shows that only a relatively small distortion was necessary to account for the modulation depth tuning curves. The results from this thesis indicate that the carrier is crucial to the perception of second- order motion. Differences in response to first- and second-order motion may depend upon properties of the stimuli rather than the operation of separate mechanisms. It is argued that the results cast some doubt over the notion of a second-order channel. A number of alternatives are discussed

Expression Dependence in the Perception of Facial Identity

We recognise familiar faces irrespective of their expression. This ability, crucial for social interactions, is a fundamental feature of face perception. We ask whether this constancy of facial identity may be compromised by changes in expression. This, in turn, addresses the issue of whether facial identity and expression are processed separately or interact. Using an identification task, participants learned the identities of two actors from naturalistic (so-called ambient) face images taken from movies. Training was either with neutral images or their expressive counterparts, perceived expressiveness having been determined experimentally. Expressive training responses were slower and more erroneous than neutral training responses. When tested with novel images of the actors that varied in expressiveness, neutrally trained participants gave slower and less accurate responses to images of high compared with low expressiveness. These findings clearly demonstrate that facial expressions impede the processing and learning of facial identity. Because this expression dependence is consistent with a late bifurcation model of face processing, in which changeable facial aspects and identity are coded in a common framework, it suggests that expressions are a part of facial identity representation. </jats:p

Perceived duration increases with contrast, but only a little

Recent adaptation studies provide evidence for early visual areas playing a role in duration perception. One explanation for the pronounced duration compression commonly found with adaptation is that it reflects adaptation-driven stimulus-specific reduction in neural activity in early visual areas. If this level of stimulus-associated neural activity does drive duration, then we would expect a strong effect of contrast on perceived duration as electrophysiological studies shows neural activity in early visual areas to be strongly related to contrast. We employed a spatially isotropic noise stimulus where the luminance of each noise element was independently sinusoidally modulated at 4 Hz. Participants matched the perceived duration of a high (0.9) or low (0.1) contrast stimulus to a previously presented standard stimulus (600ms, contrast = 0.3). To achieve perceptually equivalent durations, the low contrast stimulus had to be presented for longer than the high contrast stimulus. This occurred when we controlled for stimulus size and when we adjusted for individual differences in perceived temporal frequency. Further, we show that the effect cannot be explained by shifts in perceived onset and offset and is not explained by a simple contrast-driven response bias. The direction of our results is clearly consistent with the idea that level of neural activity drives duration. However, the magnitude of the effect (~10% duration difference over a 0.9 to 0.1 contrast reduction) is in marked contrast to the larger duration distortions that can be found with repetition suppression and the oddball effect; particularly when these may be associated with smaller differences in neural activity than that expected from our contrast difference. Taken together, these results indicate that level of stimulus-related neural activity in early visual areas is unlikely to provide a general mechanism for explaining differences in perceived duration

Measuring the Impact of Cognitive Behavioral Coaching with Nonverbal Immediacy on the Self-Efficacy of Undergraduate Students in STEM Courses

A quasi-experimental study explored whether the practice of cognitive behavioral coaching with an intentional focus on nonverbal immediacy has an impact on the self-efficacy of undergraduate students taking college-level STEM (Science, Technology, Engineering, and Mathematics) courses. A positive impact to self-efficacy for students who receive the coaching intervention was anticipated. The research took place at a public research university located in the Midwest. Subjects included students who were required to work with a success coach as a condition of their enrollment and/or financial aid eligibility. Information obtained included perception of nonverbal immediacy of the coaches and self-efficacy of the student, as determined by existing assessments called, Nonverbal Immediacy Scale – Observers and Self-Efficacy for Learning Form – Abridged version. Success coaches provided the coaching intervention to students through a prescribed protocol of at least four face-to-face meetings throughout the semester with regular contact via email and phone. Students participated in the coaching interventions as mentees. Students received support by coaches to supplement their academic pursuits. Paired t-Tests (see Table 7) did not confirm that there was a significant difference between the pre-assessment scores, and the post-assessment scores; therefore, the null hypotheses were not rejected

Deciding on race:A diffusion model analysis of race-categorisation

AbstractIt has long been known that a person’s race can affect their decisions about people of another race; an observation that clearly taps into some deep societal issues. However, in order to behave differently in response to someone else’s race, you must first categorise that person as other-race. The current study investigates the process of race-categorisation. Two groups of participants, Asian and Caucasian, rapidly classified facial images that varied from strongly Asian, through racially intermediate, to strongly Caucasian. In agreement with previous findings, there was a difference in category boundary between the two groups. Asian participants more frequently judged intermediate images as Caucasian and vice versa. We fitted a decision model, the Ratcliff diffusion model, to our two choice reaction time data. This model provides an account of the processes thought to underlie binary choice decisions. Within its architecture it has two components that could reasonably lead to a difference in race category boundary, these being evidence accumulation rate and a priori bias. The latter is the expectation or prior belief that a participant brings to the task, whilst the former indexes sensitivity to race-dependent perceptual cues. Whilst we find no good evidence for a difference in a priori bias between our two groups, we do find evidence for a difference in evidence accumulation rate. Our Asian participants were more sensitive to Caucasian cues within the images than were our Caucasian participants (and vice versa). These results support the idea that differences in perceptual sensitivity to race-defining visual characteristics drive differences in race categorisation. We propose that our findings fit with a wider view in which perceptual adaptation plays a central role in the visual processing of own and other race

Flux-ratio anomalies from discs and other baryonic structures in the Illustris simulation

The flux ratios in the multiple images of gravitationally lensed quasars can provide evidence for dark matter substructure in the halo of the lensing galaxy if the flux ratios differ from those predicted by a smooth model of the lensing galaxy mass distribution. However, it is also possible that baryonic structures in the lensing galaxy, such as edge-on discs, can produce flux-ratio anomalies. In this work, we present the first statistical analysis of flux-ratio anomalies due to baryons from a numerical simulation perspective. We select galaxies with various morphological types in the Illustris simulation and ray-trace through the simulated halos, which include baryons in the main lensing galaxies but exclude any substructures, in order to explore the pure baryonic effects. Our ray-tracing results show that the baryonic components can be a major contribution to the flux-ratio anomalies in lensed quasars and that edge-on disc lenses induce the strongest anomalies. We find that the baryonic components increase the probability of finding high flux-ratio anomalies in the early-type lenses by about 8% and by about 10 - 20% in the disc lenses. The baryonic effects also induce astrometric anomalies in 13% of the mock lenses. Our results indicate that the morphology of the lens galaxy becomes important in the analysis of flux-ratio anomalies when considering the effect of baryons, and that the presence of baryons may also partially explain the discrepancy between the observed (high) anomaly frequency and what is expected due to the presence of subhalos as predicted by the CDM simulations.Comment: 16 pages, 11 figures, accepted by MNRA

Demisability of GFRP and CFRP Components of Reentering Orbital Debris: Phase I Test Results

Observations of surviving reentry debris on the ground and research performed by Hyperschall Technologie Gttingen (HTG) [1] indicated that significantly more glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP) components survive reentry than current models predict. NASAs Orbital Debris Program Office conducted a series of tests to evaluate the accuracy of material demise models for reentering orbital debris used in NASAs Object Reentry Survival Analysis Tool (ORSAT) and Debris Assessment Software (DAS). Testing is planned in a multi-phase series to allow for quick quantification of results as well as refinement of methods resulting from lessons learned during early phases. The Phase 1 tests discussed here validated ORSAT models for homogeneous metals, provided an efficient quantification of composite material demisability properties like mass loss rate and overall time to demise, and identified potential failure modes, which are currently not well understood. Phase 2 tests will be used to further understand mass loss rates and modes of both thermal and mechanical failure in composite materials. The authors exposed 95 samples of aluminum, CFRP, Kevlar fiber-reinforced polymer, GFRP, and sheets of G10 fiberglass to conditions approximating the reentry environment using an inductively coupled plasma (ICP) torch facility. The cylindrical CFRP samples were exposed to the atmospheric pressure plasma, at both the end and the midpoint, to investigate the difference in demisability between parts with exposed edges, like panels, and parts with no edges, such as carbonoverwrapped pressure vessels (COPVs). In a non-oxidative environment, no composite materials demised within the 5-minute test time. In the oxidative, elevated heat flux environment, CFRP samples demised between 210 s and 270 s. For the first 100 s of insertion time, most of the mass loss was due to pyrolysis of resin, creating an approximately bi-linear mass-loss rate curve with time. In a non-oxidative environment, carbon filaments were observed to unravel from some of the CFRP end-burned samples; however, this effect did not seem to affect the overall time to demise for the samples significantly. These results indicate that both GFRP and CFRP components survive reentry with significantly more remaining mass than current models predict

The scientific case for magnetic field satellites

To make full use of modern magnetic data and the paleomagnetic record, we must greatly improve our understanding of how the geodynamo system works. It is clearly nonlinear, probably chaotic, and its dimensionless parameters cannot yet be reproduced on a laboratory scale. It is accessible only to theory and to measurements made at and above the earth's surface. These measurements include essentially all geophysical types. Gravity and seismology give evidence for undulations in the core-mantle boundary (CMB) and for temperature variations in the lower mantle which can affect core convection and hence the dynamo. VLBI measurements of the variations in the Chandler wobble and length of day are affected by, among other things, the electromagnetic and mechanical transfer of angular momentum across the CMB. Finally, measurements of the vector magnetic field, its intensity, or its direction, give the most direct access to the core dynamo and the electrical conductivity of the lower mantle. The 120 gauss coefficients of degrees up to 10 probably come from the core, with only modest interference by mantle conductivity and crustal magnetization. By contrast, only three angular accelerations enter the problem of angular momentum transfer across the CMB. Satellite measurements of the vector magnetic field are uniquely able to provide the spatial coverage required for extrapolation to the CMB, and to isolate and measure certain magnetic signals which to the student of the geodynamo represent noise, but which are of great interest elsewhere in geophysics. Here, these claims are justified and the mission parameters likely to be scientifically most useful for observing the geodynamo system are described

The Economic and Social Effects of Casino Development in Macau

This paper explores the economic impacts that took place in Macau after the gaming monopoly ended in 2002, as well as the resulting social effects to the local region. The broader research on casino gaming was analyzed, and was then compared to the social and economic impacts that took place in Macau. Specifically, economic indicators such as employment and GDP were evaluated, along with social issues such as problem gambling, crime, and educational attainment. Many countries, specifically Asian countries, are now entertaining the idea of introducing casinos to their local communities in an effort to try and replicate the type of economic growth that was experienced in Macau. The difficulty for these regional governments is trying to understand whether the results that took place in Macau are transferable to other Asian countries. This paper assists in answering this question, and details the unique variables that surrounded Macau’s casino development