MHC class II and invariant chain biosynthesis and transport during maturation of human precursor dendritic cells

Dendritic cells (DC) are highly potent activators of the immune response. The precise mechanisms that give rise to the DC phenotype are not known. To investigate the mechanisms that contribute to the generation of the DC phenotype, precursor DC were freshly isolated from human blood and allowed to mature in vitro. These matured DC showed the phenotypical and functional characteristics of DC. Analysis of the MHC class II and invariant chain (li) biosynthesis revealed that upon maturation, class II synthesis was induced whereas li synthesis was significantly up-regulated. In mature DC, despite the presence of large amounts of li, export of MHC class II molecules from the endoplasmic reticulum was incomplete, up to 4 h after biosynthesis. Thus, MHC class II-li synthesis and transport in DC is highly regulated during maturation of DC. Analysis of the regulatory mechanisms may contribute to a better understanding of antigen-presenting capacities during the differentiation of DC.     

Chip-package codesign of a low-power 5-GHz RF front end

Future high-performance wireless communication applications such as wireless local area networks (WLANs) around 5 GHz require low-power and highly integrated transceiver solutions. The integration of the RF front end especially poses a great challenge in these applications, as traditional front-end implementations require a large number of external passive components. In this paper, we present the single-package integration of complete transceivers based on a thin-film multichip module (MCM) technology with integrated passives. The MCM substrate is a a common carrier onto which different ICs are mounted. passive components such as RF bandpass filters, inductors, capacitors, and resistors are directly integrated into the MCM substrate with the use of the multilayer structure of the MCM technology. The “system-on-a-package” approach is illustrated with a voltage-controlled oscillator for Digital European Cordless Telephone (DECT) applications and a 5-GHz WLAN front end. These examples indicate that this approach yields a compact low-power implementation of complete transceivers for high-performance wireless applications     

Combined CFD and Experimental Approach for Determination of the Surface Heat Transfer Coefficient During Thermal Processing of Eggs

A combined Computational Fluid Dynamics (CFD) and experimentally based approach is presented for determining the surface heat transfer coefficient acting at the shell when processing intact eggs. The methodology comprises (1) determining the contour of eggs from digital photographs, (2) generating a computational geometry, and (3) predicting the transient temperature profiles in eggs filled with a conductive heating medium. CFD profiles were compared with experimentally observed data, and the surface heat transfer coefficient was obtained through an optimization procedure. Agar gel was used as a model system, having properties very similar to those of water. The approach eliminates unknown factors such as natural convection, which is expected to occur in real eggs.     

A new approach to combine texture compression and filtering

Texture mapping has been widely used to improve the quality of 3D rendered images. To reduce the storage and bandwidth impact of texture mapping, compression systems are commonly used. To further increase the quality of the rendered images, texture filtering is also often adopted. These two techniques are generally considered to be independent. First, a decompression step is executed to gather texture samples, which is then followed by a separate filtering step. We have investigated a system based on linear transforms that merges both phases together. This allows more efficient decompression and filtering at higher compression ratios. This paper formally presents our approach for any linear transformation, how the commonly used discrete cosine transform can be adapted to this new approach, and how this method can be implemented in real time on current-generation graphics cards using shaders. Through reuse of the existing hardware filtering, fast magnification and minification filtering is achieved. Our implementation provides fully anisotropically filtered samples four to six times faster than an implementation using two separate phases for decompression and filtering. Additionally, our transform-based compression also provides increased and variable compression ratios over standard hardware compression systems at a comparable or better quality level.     

Exploring the role of content knowledge in teacher design conversations

This study investigated the role of content knowledge in conversations of kindergarten teachers during collaborative curriculum design of learning material for technology‐enhanced learning. Two teams of teachers received support from an early literacy expert during these design activities. Resulting conversations were analyzed on technological pedagogical content knowledge, explicated reasoning, and the contributions of expert support. This study found that in explicating content knowledge and pedagogical content knowledge, teachers set goals and deliberated on strategies and activities that would be most appropriate for their students. Technological content knowledge and technological pedagogical content knowledge were explicated most during deliberations on practical concerns; these mainly revolved around optimizing the affordances of technology. This study contributes to understanding and supporting the pedagogical design capacity of teachers.     

CFD analysis of air distribution in fluidised bed equipment

The unique features of the fluidised bed—excellent mixing capacity and high heat and mass transfer rates—are highly dependent on the quality of fluidisation resulting from the bubble characteristics of the fluidising gas, which to a large extent depend on the distributor design. In order to understand the fluidisation hydrodynamics of a fluidised bed operation, it is essential to assess how airflow is distributed through the equipment. This paper reports on the use of Computational Fluid Dynamics (CFD) as a numerical tool to enlarge this understanding. CFD simulations were performed for a Glatt GPCG-1 fluidised bed coater in which stainless steel woven wire mesh distributors are used as the standard distributor plates. Firstly, an experiment was set up in which the permeability and the inertial resistance of the investigated distributors were determined. Using these inputs, two types of boundary conditions, available in the CFD software Fluent, to model a porous medium such as a distributor, were compared. Furthermore, the CFD simulations were verified in the lab-scale fluidised bed unit using air mass flow rate, pressure drop and inner wall temperature recordings. As an unequal airflow inside the plenum of the GPCG-1 was found to occur, CFD was used as a design tool to investigate reactor configuration changes in order to obtain a more homogeneous airflow towards the distributor.     

Diffusion of radiation transmitted through dry and condensate covered transmitting materials

Next to the irradiation level, the extent to which the transmitted radiation is diffused, gains interest in the field of protected plant production and other kinds of solar collector systems. By means of a laboratory measuring unit, the diffusive behaviors of four transmitting materials, namely single glass (SG), low density polyethylene (LDPE), anti-drop condensation polyethylene (ADCPE) and diffusive polyethylene, were investigated in the dry state and when covered with condensate. Dry SG hardly diffused radiation and behaved as an optically smooth material. Due to their surface roughness and bulk heterogeneities, the LDPE film and the ADCPE film diffused about 50% of the transmitted radiation, while the diffusive polyethylene film diffused more than 80% of the transmitted radiation in the dry state. When covered with condensate, the diffuse fractions of the transmitted radiation of all four materials, except the ADCPE, were obviously enhanced. Wet SG and wet LDPE showed a similar diffusion pattern. Slightly more than 80% of the transmitted radiation was diffused by both materials. The diffusive polyethylene film remained the most diffusive transmitting material in the wet state. More than 90% of the transmitted radiation was diffused. About one quarter of the transmitted radiation was diffused at angles greater than 45°. None of the materials investigated in the dry as well as in the wet state approached a Lambertian diffusion pattern.     

The Precautionary Principle in a World of Digital Dependencies

As organizations become deperimeterized, a new paradigm in software engineering ethics becomes necessary. We can no longer rely on an ethics of consequences, but might instead rely on the precautionary principle, which lets software engineers focus on creating a more extensive moral framework.     

Plasmonic back contacts with non-ordered Ag nanostructures for light trapping in thin-film silicon solar cells

In this work, we investigate the light trapping of thin-film silicon solar cells which apply plasmonic Ag back contacts with non-ordered Ag nanostructures. The preparation, characterization and three-dimensional electromagnetic simulations of these back contacts with various distributions of non-ordered Ag nanostructures are presented. The measured reflectance spectra of the Ag back contacts with non-ordered nanostructures in air are well reproduced in reflectance spectra derived from the three-dimensional electromagnetic simulations of isolated nanostructures on Ag back contacts. The light–matter interaction of these nanostructures is given by localized surface plasmons and, thus, the measured diffuse reflectance of the back contacts is attributed to plasmon-induced light scattering. A significant plasmonic light-trapping effect in n-i-p substrate-type μc-Si:H thin-film solar cell prototypes which apply a Ag back contact with non-ordered nanostructures is identified when compared with flat reference solar cells.     

Multivalent carbohydrate recognition on a glycodendrimer-functionalized flow-through chip

Dendrimers were fitted out with up to eight mannose moieties by "click" chemistry. They were subsequently attached to aluminum oxide chips via a spacer that was linked to the dendrimer core; this resulted in a microarray of glycodendrimers. Binding of the glycodendrimers to the fluorescent lectins ConA and GNA was observable in real time. In a single experiment it was possible to observe the multivalency enhancement or cluster effect in the binding event. This effect was small for ConA, in agreement with its widely spaced binding sites, whereas it was large for GNA, with its twelve much more closely spaced binding sites. The dendrimer-fitted chip represents a valuable screening tool for multivalency effects. Furthermore kinetic and thermodynamic data on binding events can be deduced. Inhibition experiments are also possible with the system as was shown for ConA with alpha-methyl mannose as the inhibitor.