IL-10 inhibits alloreactive cytotoxic T lymphocyte generation in vivo

In this report, we present evidence that the CTL response directed against MHC Class I allo-determinants can be inhibited as a result of IL-10 expression in vivo. The presence of localized IL-10 secretion at the site of allogeneic tumor cell challenge resulted in marked inhibition of the CTL response and allowed growth of the tumor in the allogeneic host. Using purified CD4+ T cells from mice immunized in the presence or absence of IL-10, we have shown that the loss of alloreactivity as a consequence of IL-10 expression results from the inhibition of CD4+ T cell function. The expression of either IL-2 or IFN-gamma with IL-10 locally at the time of allogeneic cell challenge completely restored CTL alloreactivity, suggesting that the action of IL-10 could be bypassed by providing helper T lymphocyte-derived cytokines of the Th1 type at the site of immunization. Inhibition of alloreactivity by IL-10 was observed using either purified macrophages or dendritic cells as APC in an in vitro assay. Thus, the expression of IL-10 following antigenic challenge (such as that observed in Th2-like immune responses) may profoundly limit the ability for generating functional CTL in vivo.     

The influence of training level on manual flight in connection to performance,scan pattern,and task load

This work focuses on the analysis of pilots’ performance during manual flight operations in different stages of training and their influence on gaze strategy. The secure and safe operation of air traffic is highly dependent on the individual performances of the pilots. Before becoming a pilot, he/she has to acquire a broad set of skills by training to pass all the necessary qualification and licensing standards. A basic skill for every pilot is manual control operations, which is a closed-loop control process with several cross-coupled variables. Even with increased automation in the cockpit, the manual control operations are essential for every pilot as a last resort in the event of automation failure. A key element in the analysis of manual flight operations is the development over time in relation to performance and visual perception. An experiment with 28 participants (including 11 certified pilots) was conducted in a Boeing 737 simulator. For defined flight phases, the dynamic time warping method was applied to evaluate the performance for selected criteria, and eye-tracking methodology was utilized to analyze the gaze-pattern development. The manipulation of workload and individual experience influences the performance and the gaze pattern at the same time. Findings suggest that the increase of workload has an increased influence on pilots depending on the flight phase. Gaze patterns from experienced pilots provide insights into the training requirements of both novices and experts. The connection between workload, performance and gaze pattern is complex and needs to be analyzed under as many differing conditions. The results imply the necessity to evaluate manual flight operations with respect to more flight phases and a detailed selection of performance indications.

     

Effects of Al:Si and (Al + Na):Si ratios on the properties of the international simple glass,part II: Structure

High-alumina containing high-level waste (HLW) will be vitrified at the Waste Treatment Plant at the Hanford Site. The resulting glasses, high in alumina, will have distinct composition-structure-property (C-S-P) relationships compared to previously studied HLW glasses. These C-S-P relationships determine the processability and product durability of glasses and therefore must be understood. The main purpose of this study is to understand the detailed structural changes caused by Al:Si and (Al + Na):Si substitutions in a simplified nuclear waste model glass (ISG, international simple glass) by combining experimental structural characterizations and molecular dynamics (MD) simulations. The structures of these two series of glasses were characterized by neutron total scattering and ²⁷Al, ²³Na, ²⁹Si, and ¹¹B solid-state nuclear magnetic resonance (NMR) spectroscopy. Additionally, MD simulations were used to generate atomistic structural models of the borosilicate glasses and simulation results were validated by the experimental structural data. Short-range (eg, bond distance, coordination number, etc) and medium-range (eg, oxygen speciation, network connectivity, polyhedral linkages) structural features of the borosilicate glasses were systematically investigated as a function of the degree of substitution. The results show that bond distance and coordination number of the cation-oxygen pairs are relatively insensitive to Al:Si and (Al + Na):Si substitutions with the exception of the B-O pair. Additionally, the Al:Si substitution results in an increase in tri-bridging oxygen species, whereas (Al + Na):Si substitution creates nonbridging oxygen species. Charge compensator preferences were found for Si-[NBO] (Na⁺), ^[3]B-[NBO] (Na⁺), ^[4]B (mostly Ca²⁺), ^[4]Al (nearly equally split Na⁺ and Ca²⁺), and ^[6]Zr (mostly Ca²⁺). The network former-BO-network former linkages preferences were also tabulated; Si-O-Al and Al-O-Al were preferred at the expense of lower Si-O-^[3]B and ^[3]B-O-^[3]B linkages. These results provide insights on the structural origins of property changes such as glass-transition temperature caused by the substitutions, providing a basis for future improvements of theoretical and computer simulation models.     

In situ, noninvasive characterization of superhydrophobic coatings

Light scattering was used to measure the time-dependent loss of air entrapped within a submerged microporous hydrophobic surface subjected to different environmental conditions. The loss of trapped air resulted in a measurable decrease in surface reflectivity and the kinetics of the process was determined in real time and compared to surface properties, such as porosity and morphology. The light-scattering results were compared with measurements of skin-friction drag, static contact angle, and contact-angle hysteresis. The in situ, noninvasive optical technique was shown to correlate well with the more conventional methods for quantifying surface hydrophobicity, such as flow slip and contact angle.     

Real-time simulation of time-of-flight sensors

Today’s time-of-flight (TOF) sensors measure full-range distance information by estimating the elapsed time between emission and receiving of active light in real-time. Such sensors are inexpensive, compact, and they have a high performance, which especially fits real-time applications, e.g. in the fields of automotive, robotics, 3D imaging, and visualization. The simulation of such sensors is an essential building block for hardware design and application development. Therefore, the simulation data must capture the major sensor characteristics.This paper introduces a simulation approach, which is motivated by physics, for the Photonic Mixing Device (PMD) sensor which is a specific type of time-of-flight sensor. Dynamic motion blurring and resolution artifacts such as flying pixels as well as the typical deviation error are prominent effects of real world systems. Flying pixels arise when an area of inhomogeneous depth is covered by a single PMD-pixel whereas the deviation error is based on the anharmonic properties of the optical signal. The modeling of these artifacts is essential for an authentic simulation approach. We present a detailed comparison between a real PMD-device and the simulation data regarding the sensor characteristics.The proposed algorithms are implemented in a hardware accelerated solution which makes use of the programmability of modern Graphics Processing Units (GPUs). This way, an interactive simulation feedback is provided for applications and further data processing. The simulation takes place in real-time and thus all required control mechanisms are accessible in real-time, too.     

High-level user interfaces for transfer function design with semantics

Many sophisticated techniques for the visualization of volumetric data such as medical data have been published. While existing techniques are mature from a technical point of view, managing the complexity of visual parameters is still difficult for non-expert users. To this end, this paper presents new ideas to facilitate the specification of optical properties for direct volume rendering. We introduce an additional level of abstraction for parametric models of transfer functions. The proposed framework allows visualization experts to design high-level transfer function models which can intuitively be used by non-expert users. The results are user interfaces which provide semantic information for specialized visualization problems. The proposed method is based on principal component analysis as well as on concepts borrowed from computer animation.