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.     

Characterization of the gonioapparent character of colored anodized titanium surfaces

We investigate the gonioapparent character of colored anodized titanium surfaces. In appropriate experimental conditions, the anodizing process generates a homogeneous oxide layer at the surface of the metal, with a thickness comparable with the visible wavelengths of light. The anodized metallic surfaces thus exhibit interferential colors, which depend on the thickness of the oxide layer and have the particularity to vary according to the illumination and observation directions. They are said to be gonioapparent. This article describes an experimental method to characterize these variations precisely. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 483–490, 2015     

Mnemonic organization and free recall in schizophrenia.

Investigated word-storage structure and processes of organization and retrieval in 17 young schizophrenics (mean age 26.5 yrs) and 13 normal Ss (mean age 25.7 yrs). Ss were required to establish a stable organization of 25 unrelated words through repeated, self-paced sortings into self-determined categories. Subsequently, they were asked for free recall of the words. The schizophrenics required significantly more trials to complete the sorting task, but once this was achieved they recalled as many words in equally regular order as the normals did. The groups did not differ in regard to organizational structure in the sortings as assessed by hierarchical structure analysis. It is concluded that a schizophrenic deficit of mnemonic organization is indicated, possibly due to difficulties in maintaining a stable system of categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modelling alarm management workflow in healthcare according to IHE framework by coloured Petri Nets

Ensuring patient safety in medical device networks by managing alarms and related clinical data is a life-critical issue. The Integrating the Healthcare Enterprise (IHE) initiative emerged to discuss and solve the interoperability and integration problems among medical information systems, vendors and users in order to improve patient care and healthcare system dependability. This paper models and analyzes the IHE Alarm Communication Management by using the Unified Modelling Language and Coloured Timed Petri nets. Aiming at generality, the model does not refer to a specific healthcare context but it is based on a general scheme where the message transactions are integrated with the nurse responses. In order to show the potentialities of the model, a real case study is simulated and different scenarios with different levels of workload are analyzed. The results illustrate that the model is able to provide support for structured and comprehensive analysis of the healthcare system management.     

Living cells of Staphylococcus aureus immobilized onto the capillary surface in electrochromatography: a tool for screening of biofilms

Microorganisms attach to nonliving surfaces in many natural, industrial, and medical environments, enveloped within extracellular polymeric substances. The result is a biofilm. Biofilms are reported to exist in 65-80% of bacterial infections refractory to host defenses and antibiotics therapy and are regarded as a central problem in present-day medical microbiology. Understanding of the parameters governing the interaction of antimicrobials with biofilms is thus of great interest in any attempt to increase biocide efficacy. In this work, study was made of the feasibility of using open tubular capillary electrochromatography (CEC) in bacterial biofilm studies with living cells. Staphylococcus aureus was selected as model bacterium. First, S. aureus was shown, under various conditions, to form a biofilm on the inner wall of a fused-silica capillary coated with poly(L-lysine). Optimal conditions for biofilm formation, such as bacterial concentration, growing time, and the stability of the ensemble, were preliminarily defined with conventional 96-microtiter well plates. Continuous flushing of the capillary with fresh cells meant that no growth medium was needed. The presence of biofilm in the capillary was confirmed by atomic force microscopy. Interactions between S. aureus biofilms and different antibiomicrobial agents were studied by capillary electrochromatography. The effect of five antibiotics (penicillin G, oxacillin, fusidic acid, rifampicin, vancomycin) on biofilms was examined in terms of retention factors and reduced mobilities of the antibiotics. The antibiotic susceptibility profile for S. aureus is similar as the result of minimal inhibitory concentrations registered on the 96-microtiter well plates for both planktonic and biofilm cells. The results show, for the first time, that bacterial biofilms can be studied by CEC. The technique allows highly efficient and easy characterization of interactions between S. aureus biofilms and potentially active antimicrobial compounds under different conditions. Reagent and cell consumption are minimal.     

Surface wear resistance of chemically or thermally stabilized earth-based materials

The paper is concerned with the wind erosion resistance of earth-based building materials. With the spatial extent of drylands likely to increase, this aspect will become ever more important for present settlements and the conservation of archaeological site. Experiments were conducted on a soil with high kaolin content, adding sand, hydraulic cements, lime and organic polymers or on the same earth modified by means of low (below ceramization) temperature heat treatment. The stabilization practices currently performed or tested are designed primarily to improve water stability and compressive strength of this class of humble materials. However, very little is known about the effects that these modifications actually produce on surface erosion resistance. An experimental set up designed to simulate the erosive effects of wind-borne particles is described. The experimental data obtained make it possible to clearly discriminate between the different types of material used and indicate that some of the most commonly used earth stabilization products actually have a negative effect on surface durability.     

Learning game for improving forklift drivers’ safety awareness

Cognition, Technology & Work - Forklift drivers in in-house logistics are at a high risk of occupational injuries. This study piloted a video-based learning game for forklift drivers, designed...     

Colostrum and milk protein rankings and ratios of importance to neonatal calf health using a proteomics approach

Administration of colostrum to the newborn calf before gut closure is pivotal to its health, because of the transfer of passive immunity. Traditionally, passive immunity has been attributed to the transfer of immunoglobulins although it is increasingly clear that multiple other factors contribute, including innate immune proteins, developmental factors, immunomodulatory factors, and the presence of cellular immunity. The objective of this study was to produce a comprehensive comparison of the bovine colostrum proteome and the milk proteome by applying 2-dimensional liquid chromatography-tandem mass spectrometry. Further, the objectives were to rank proteins mutually and generate protein ratios from the spectral counts of the 2 proteomes and ELISA to gain insight into which proteins could be of most relevance to neonatal calf health. To obtain an in-depth picture of the bovine colostrum and milk proteome, we compared the contents of different fractions from bovine colostrum and milk from our 2 previous studies. A total of 140 colostrum fluid-phase proteins and 103 milk fluid-phase proteins were detected. In the cellular fraction, 324 and 310 proteins were detected in colostrum and milk, respectively. In total, 514 proteins were detected, of which 162 were in the fluid phase. Of these, 50 proteins were exclusively seen in colostrum, 13 were exclusively seen in milk, and 99 were common to colostrum and milk. Ranking of proteins mutually and calculating protein ratios based on spectral counts and ELISA resulted in new information on how proteins were associated with the fluid or cellular fraction of the samples. Interestingly, despite lower counts/concentrations than the classical proteins such as immunoglobulins, β-lactoglobulin, and lactotransferrin, several proteins appeared in higher or similar colostrum:milk spectral count ratios as these. Using this approach indicated, for example, that osteopontin, haptoglobin, milk amyloid A, and gelsolin may be interesting molecules to study in detail in their relation to calf health. Although the sensitivity, identification, and ranking of proteins varied between the 2 methods, and proteome analysis clearly suffers from low sensitivity, we believe that this idea and approach of generating ratios and ranking proteins can contribute new information and perspectives on how to prioritize the importance of multiple proteins, beyond immunoglobulins, in relation to neonatal calf health.