Virtual reality in posturography.

Balance dysfunctions are common, especially among elderly people. Present methods for the diagnosis and evaluation of severity of dysfuntion have limited value. We present a system that makes it easy to implement different visual and mechanical perturbations for clinical investigations of balance and visual-vestibular interaction. The system combines virtual reality visual stimulation with force platform posturography on a moving platform. We evaluate our contruction's utility in a classification task between 33 healthy controls and 77 patients with Ménière's disease, using a series of tests with different visual and mechanical stimuli. Responses of patients and controls differ significantly in parameters computed from stabilograms. We also show that the series of tests achieves a classification accuracy slightly over 80% between controls and patients.     

The Deuterium Isotope Effect as a Tool to Investigate Enzyme Catalysis: Proton-Transfer Control Mechanisms in Cytochrome c Oxidase

Cytochrome c oxidase is a membrane-bound redox-driven proton pump. The coupling of the exergonic electron-transfer reactions from cytochrome c to oxygen to proton translocation across the membrane requires control of internal electron- and proton-transfer reactions. In this work, we focus on the kinetics of electron and proton transfer during those reaction steps that are coupled to proton pumping in cytochrome c oxidase. The results show that during the first pumping step (peroxy → oxoferryl transition), proton transfer regulates intramolecular electron transfer. The proton transfer takes place in two steps: (1) Internal proton transfer from a protonatable group, proposed to be Glu(I-286), in the so-called D-pathway, to an oxygen intermediate at the binuclear center (τ ≅ 100 μs); (2) Rapid re-protonation of Glu(I-286) from the bulk solution (τ < 100 μs). Only after proton uptake from solution the last (fourth) electron is transferred “one step closer” towards the binuclear center (from Cu_A to heme a). During the second proton-pumping step (oxoferryl → oxidized), this electron is transferred to the binuclear center, linked to the uptake of a proton through the D-pathway. The electron-transfer rate displays a kinetic-isotope effect (k_H/k_D) of 6 ± 1 (in a pH range in which the pH dependence of the rate is small), which indicates that the electron transfer is rate-limited by the proton transfer. The entry into the D-pathway (around Asp(I-132)) is composed of a cluster of negatively-charged amino acid residues together with a number of histidines, forming a so-called proton-collecting antenna designed to allow rapid protonation of groups within the proton-transfer pathway.     

Absence of snapshot memory of the target view interferes with place navigation learning by rats in the water maze.

Contribution of visual and nonvisual mechanisms to spatial behavior of rats in the Morris water maze was studied with a computerized infrared tracking system, which switched off the room lights when the S entered the inner circular area of the pool with an escape platform. 10 naive male rats trained under light–dark (LD) conditions found the escape platform more slowly than 10 male rats trained in permanent light (LT). After group members were swapped, the LT-pretrained rats found under LD conditions the same target faster and eventually approached latencies attained during LT navigation. Performance of LD-trained rats deteriorated in permanent darkness (PD) but improved with continued PD training. Thus LD navigation improves gradually by procedural learning (extrapolation of the start-target azimuth into the zero-visibility zone) but remains impaired by lack of immediate visual feedback rather than by absence of the snapshot memory of the target view. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving the Safety and Efficiency of Materials Transfer at a Construction Site by Using an Elevator

The aim of this study was to compare materials transfer at a construction site, either by carrying manually or by using an elevator. Data were collected at a construction site by using two methods: continuous automatic collection of data on the use of the elevator, and measuring and observing the transportation of some products when different delivery systems were used. Health and safety risks were at their highest when transporting products manually at construction sites. Risks decrease when vertical (an elevator) and horizontal (a wheeled device) transportation tools are used. A similar improvement as in health and safety risks can be seen in efficiency results: The working time needed with the elevator was 41% of the purely manual handling time. When wheeled devices were used, the transportation time was decreased to 16%. The early use of a permanent elevator succeeded well and its capacity was large enough. The effective use of the elevator and wheeled devices require that pathways are in better condition than normally.     

Biocompatibility of highly macroporous ceramic scaffolds: cell adhesion and morphology studies

Hydroxyapatite porous scaffolds can be used for tissue engineering applications since they can serve as templates for cell adhesion, proliferation and ultimately for tissue repair. One way to address this issue is to evaluate the cell adhesion using several characterization techniques namely, cytotoxicity assays and cell visualization. On the other hand, when using highly macroporous scaffolds some techniques may not be adequate for evaluation, such as MTT. In this work, cytotoxicity assay (MTS), scanning electron microscopy (SEM) and Confocal laser scanning microscopy (CLSM) were used to evaluate cell adhesion in highly macroporous hydroxyapatite scaffolds. It was possible to observe that some techniques were not suitable to evaluate cell adhesion. In addition, it was shown that for this kind of scaffolds, confocal laser scanning microscopy is a powerful tool for cell adhesion and proliferation evaluation.     

Systematic Assessment of Maps as Source Information in Landscape-change Research

A methodology is proposed for systematic map assessment to contribute to landscape-change research. Two major topic areas are dealt with, namely: content, quality and usefulness of landscape information on different maps; and methods used in the spatial conversion of maps into digital systems (e.g. geographical information systems). The major focus is on information about physical landscape characteristics (e.g. land cover) and land uses. The approach was tested using a sequence of nine large- and medium-scale basic maps of the island of Ruissalo in SW Finland from between 1690 and 1998. Fundamental differences were found in the thematic consistency of landscape information, mainly related to the scale, purpose and generalization of landscape information on different maps. Spatial matching was tested for a set of three old maps using four image rectification functions. The results showed that spatial matching of old maps is difficult, and success in rectification is influenced by many factors. Evaluation and selective transformation of landscape information from maps and the use of supportive information from other sources can assist in landscape-change analysis based on map sequences.     

Investigating the fermentation of cocoa by correlating denaturing gradient gel electrophoresis profiles and near infrared spectra

Raw cocoa has an astringent, unpleasant taste and flavour, and has to be fermented, dried and roasted in order to obtain the characteristic cocoa flavour and taste. During the fermentation microbial activity outside the cocoa beans induces biochemical and physical changes inside the beans. The process is complex involving activity of several different groups of microorganisms which bring about numerous biochemical and physical changes inside the beans. Due to the complexity of these processes no thorough investigations of the interactions between the microbial activities on the outside of the beans and the chemical processes inside the beans have been carried out previously. Recently it has been shown that Denaturing Gradient Gel Electrophoresis (DGGE) offers an efficient tool for monitoring the microbiological changes taking place during the fermentation of cocoa. Near Infrared (NIR) spectroscopy has previously been used to determine various components in cocoa beans, offering a rapid alternative compared to traditional analytical methods for obtaining knowledge about changes in the chemical composition of the cocoa beans during fermentation. During a number of cocoa fermentations bean samples were taken with 24 h intervals to be dried and analysed by NIR. Cocoa pulp samples taken simultaneously during the same fermentations have previously been characterised using DGGE [Nielsen, D.S., Teniola, O.D., Ban-Koffi, L., Owusu, M., Andersson, T., Holzapfel, W.H. (2007). The microbiology of Ghanaian cocoa fermentations analysed using culture dependent and culture-independent methods. International Journal of Food Microbiology 114, 168-186.]. Here we report the first study where microbiological changes during the fermentation determined using DGGE are correlated to changes inside the beans determined by NIR using multivariate data analysis. Following data pre-processing (baseline correction followed by Co-shift correction or Correlation Optimised Warping) the DGGE spectra were analysed using Principal Component Analysis (PCA). A clear grouping according to fermentation time was seen demonstrating the microbial succession taking place during the fermentation. Subsequently the DGGE spectra were correlated to the NIR spectra using Partial Least Squares regression models (PLS2). Correlations of 0.87 (bacterial derived DGGE spectra) and 0.81 (yeast derived DGGE spectra) were obtained indicating the relationship between the microbial activities in the pulp and the (bio)chemical changes inside the beans. By comparing the X-block loadings of the PLS2 models and the DGGE spectra it was possible to directly link several microbial species with changes in the NIR spectra and consequently also with changes inside the beans.     

Tilting the Balance: Therapeutic Prospects of CD83 as a Checkpoint Molecule Controlling Resolution of Inflammation

Chronic inflammatory diseases and transplant rejection represent major challenges for modern health care. Thus, identification of immune checkpoints that contribute to resolution of inflammation is key to developing novel therapeutic agents for those conditions. In recent years, the CD83 (cluster of differentiation 83) protein has emerged as an interesting potential candidate for such a “pro-resolution” therapy. This molecule occurs in a membrane-bound and a soluble isoform (mCD83 and sCD83, respectively), both of which are involved in resolution of inflammation. Originally described as a maturation marker on dendritic cells (DCs), mCD83 is also expressed by activated B and T cells as well as regulatory T cells (Tregs) and controls turnover of MHC II molecules in the thymus, and thereby positive selection of CD4⁺ T cells. Additionally, it serves to confine overshooting (auto-)immune responses. Consequently, animals with a conditional deletion of CD83 in DCs or regulatory T cells suffer from impaired resolution of inflammation. Pro-resolving effects of sCD83 became evident in pre-clinical autoimmune and transplantation models, where application of sCD83 reduced disease symptoms and enhanced allograft survival, respectively. Here, we summarize recent advances regarding CD83-mediated resolution of inflammatory responses, its binding partners as well as induced signaling pathways, and emphasize its therapeutic potential for future clinical trials.