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)     

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.     

Scale-up of manufacturing of printed enzyme electrodes for enzymatic power source applications

Production of printable enzymatic power sources was scaled up from laboratory to roll-to-roll (R2R) pilot production. The anode and cathode enzymes were glucose oxidase (GOx) and laccase, respectively. The best laboratory-scale cells had a maximum power and energy density of 1.4 ± 0.1 µW cm^?2 and 5.5 ± 0.2 µWh cm^?2, respectively. These values are 5 and 28 times higher compared to our previously published values. The R2R-produced cells had a maximum power and energy density of 0.40 ± 0.03 µW cm^?2 and 0.6 ± 0.1 µWh cm^?2, respectively. This is 11 % of the best laboratory manufactured cells. It is suspected that the decrease in electrochemical performance originates from the lower mediator amount and higher drying temperature than that of the laboratory produced cells. However, the trials conducted in this work showed that printed enzymatic active layers can be fabricated and dried with a rotary screen-printing machine in R2R process. Hence, fully printed GOx//laccase power sources could be produced from R2R on a large scale for printed electronics applications.     

(+)-Dehydroabietic Acid,an Abietane-Type Diterpene,Inhibits Staphylococcus aureus Biofilms in Vitro

Potent drugs are desperately needed to counteract bacterial biofilm infections, especially those caused by gram-positive organisms, such as Staphylococcus aureus. Moreover, anti-biofilm compounds/agents that can be used as chemical tools are also needed for basic in vitro or in vivo studies aimed at exploring biofilms behavior and functionability. In this contribution, a collection of naturally-occurring abietane-type diterpenes and their derivatives was tested against S. aureus biofilms using a platform consisting of two phenotypic assays that have been previously published by our group. Three active compounds were identified: nordehydroabietylamine (1), (+)-dehydroabietic acid (2) and (+)-dehydroabietylamine (3) that prevented biofilm formation in the low micromolar range, and unlike typical antibiotics, only 2 to 4-fold higher concentrations were needed to significantly reduce viability and biomass of existing biofilms. Compound 2, (+)-dehydroabietic acid, was the most selective towards biofilm bacteria, achieving high killing efficacy (based on log Reduction values) and it was best tolerated by three different mammalian cell lines. Since (+)-dehydroabietic acid is an easily available compound, it holds great potential to be used as a molecular probe in biofilms-related studies as well as to serve as inspirational chemical model for the development of potent drug candidates.     

Lignin and lignin derivatives as components in biobased hot melt adhesives

Hot melt adhesives (HMAs) are formulated for the first time with different lignins as major components, and the developed HMA formulations were tested for gluing paperboard. The best formulations showed equal or even better bond strength compared to a commercial HMA reference. A maximum bond strength of 16.1 N was achieved with a formulation of oxidized cellulose acetate, organosolv lignin, and triethyl citrate, whereas the bond strength of the commercial HMA reference was 10.5 N. The performance was adjusted via the selection of lignin, the formulation, and chemical modification. Lignin modification was not necessary but provided further possibilities for adjusting the properties for different products (reversible vs irreversible adhesive seams) and also for producing plasticizer-free formulations. Modification with tall oil fatty acids enabled the formulation of fully biobased HMAs without any external plasticizer and provided a bond strength as high as high as 8.9 N. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47983.     

Numerical modelling of cold compaction of metal powder

A finite element programme has been developed for the analysis of porosity and stress distributions in a powder compact, based on rate-independent finite strain plasticity theory. The strain hardening versions of the Gurson model (J. Engng. Mater. Technol., 1977, 99, 2-15), the more recent FKM model (J. Mech. Phys. Solids, 1992, 40(5), 1139-1162), developed by Fleck, Kuhn and McMeeking, and a combination of the two models are used. The friction between the mould wall and the metal powder is modelled by a combination of Coulomb friction and a constant friction shear stress, since Coulomb friction is not realistic at high normal pressures. The finite element programme has been used to study the effects of friction, compaction method, and material parameters. Analyses for powder compacts of various geometries are presented to illustrate the method.