2,723 research outputs found
The role of Ruditapes philippinarum glutathione transferases in the metabolism of microcystin-LR
No full textNo abstracts are to be cited without prior reference to the author. Glutathione transferases (GSTs) are phase II enzymes involved in the microcystin (MC) induced detoxication processes. In this study we analyze and compare the metabolism of MC-LR by the cytosolic GSTs from gills and hepatopancreas of Ruditapes philippinarum. Cytosolic GSTs were purified by glutathione (GSH)–agarose affinity chromatography from exposed and non-exposed bivalves to MC-LR (100 µg/L) representing the inducible and constitutive (Basal) GST fractions, respectively. For each mixture, we examined the in vitro cytosolic GST inhibition efficiency of the conjugation of CDNB to GSH by MC-LR and characterize the inhibition mechanism. Results support the important role of GST enzymes in detoxification of MCs in bivalve mollusk
Development and evaluation of a novel low-cost sensor-based knee flexion angle measurement system
No full textBackground
Knee injuries play a large part of musculoskeletal traumas in sporting activities and the
rehabilitation can require a long period, for both the patients and the specialists, to restore
healthy condition. A reliable, portable and low cost system that could allow quick, simple
and effective measures of knee flexion angles, would greatly improve the evaluation of
the rehabilitation process and the subsequent planning procedure, with meaningful
reduction of the recovery time and cost.
Methods
It is proposed a novel tool for the non-stop measurements of the knee flexion angles,
based on the adoption of an elastic sensor embedded in an easy-to-realize wearable
kneepad. We fully characterized this tool in terms of accuracy, repeatability and
reliability of the measure, and validated it against the gold-standard Vicon.
Results
Our tool demonstrated good reproducibility and repeatability among testers (mean Range
of measures = 5.82° ± 1.93°) and high accuracy (root mean square error <1.28°), together
with a good reliability (Intraclass Correlation Coefficient between 0.80 and 0.91).
Conclusions
The proposed tool demonstrates good performances, is portable, cheap, easy to use, and
allows automatic measurements, so to be a valuable system for accurate non-stop
measurement of knee angles
Transcriptional responses of glutathione transferase genes in Ruditapes philippinarum exposed to microcystin-LR
No full textNo abstracts are to be cited without prior reference to the author. Microcystins (MCs) are potent hepatotoxins produced by bloom-forming species of toxic cyanobacteria. Among these, MC-LR is the most commonly found and toxic variant. Bivalves, due to their benthic and sedentary mode of life, are one of the most threatened organisms by these environmental stressors. Glutathione transferases (GSTs) play a major role in cellular defense against MCs toxicity. The aim of this study was to compare the relative changes of gene expression of the different GSTs isoforms in mollusc bivalves exposed to MCs. The time-dependent changes of relative transcription abundance of several GST isoforms in parallel with enzymatic activity of total GST were investigated in gills and hepatopancreas of Ruditapes philippinarum exposed to dissolved MC-LR. The relative changes of gene expression and enzyme activity were analyzed by quantitative real-time PCR and colorimetric assays respectively. We found that MC-LR could affect the transcriptional activities of these detoxification enzymes in gills and hepatopancreas of the tested bivalves. Most GST isoforms showed differential response profiles depending on the concentrations of MC-LR and exposure times for clams. These results highlight the important role of GSTs in counteracting the potential deleterious effects induced by MCs in bivalve
Combination of classifiers using the fuzzy integral for uncertainty identification and subject specific optimization - application to brain-computer interface
No full textIn this paper we propose a framework for combination of classifiers using fuzzy measures and integrals that
aims at providing researchers and practitioners with a simple and structured approach to deal with two issues
that often arise in many pattern recognition applications: (i) the need for an automatic and user-specific selection
of the best performing classifier or, better, ensemble of classifiers, out of the available ones; (ii) the
need for uncertainty identification which should result in an abstention rather than an unreliable decision. We
evaluate the framework within the context of Brain-Computer Interface, a field in which abstention and intersubject
variability have a remarkable impact. Analysis of experimental data relative to five subjects shows that
the proposed system is able to answer such need
Describing different brain computer interface systems through a unique model: a UML implementation
No full textAll the protocols currently implemented in brain computer interface (BCI) experiments are characterized by different structural and temporal entities. Moreover, due to the lack of a unique descriptive model for BCI systems, there is not a standard way to define the structure and the timing of a BCI experimental session among different research groups and there is also great discordance on the meaning of the most common terms dealing with BCI, such as trial, run and session. The aim of this paper is to provide a unified modeling language (UML) implementation of BCI systems through a unique dynamic model which is able to describe the main protocols defined in the literature (P300, mu-rhythms, SCP, SSVEP, fMRI) and demonstrates to be reasonable and adjustable according to different requirements. This model includes a set of definitions of the typical entities encountered in a BCI, diagrams which explain the structural correlations among them and a detailed description of the timing of a trial. This last represents an innovation with respect to the models already proposed in the literature. The UML documentation and the possibility of adapting this model to the different BCI systems built to date, make it a basis for the implementation of new systems and a mean for the unification and dissemination of resources. The model with all the diagrams and definitions reported in the paper are the core of the body language framework, a free set of routines and tools for the implementation, optimization and delivery of cross-platform BCI systems
Fast removal of cyanobacterial toxin microcystin-LR by a low-cytotoxic microgel-Fe(III) complex
No full textEutrophication has become a serious environmental threat throughout the world. In particular, the presence of cyanobacteria toxins, especially microcystins (MCs), has become a severe problem. Inhibition of Microcystis growth in water resources is the most effective way to reduce MCs, but it is a long-term investment. In the present study, a microgel-Fe(III) complex was developed for the fast removal of MC-LR. The microgel-Fe(III) characteristics and the MC-LR removal dynamics in Milli-Q water and natural water were evaluated. The removal efficiency negatively correlated to the initial MC-LR concentration and pH value (2.0-11.5), but the kinetics was not significantly influenced. The presence of natural organic matter (NOM) in water slightly reduced MC-LR removal using microgel-Fe(III). In addition, microgel-Fe(III) removed 98.99% of MC-LR in 12 min, while for activated carbon, it took 15-24 h to reach equilibrium. Furthermore, methanol was found to regenerate the microgel-Fe(III) after MC-LR removal for at least five regeneration cycles. Finally, the microgel-Fe(III) material was made into a membrane so that MCs could be removed by filtration. Therefore, microgel-Fe(III) is an effective technology and has a great potential in removing MC-LR from drinking water resources. (C) 2011 Elsevier Ltd. All rights reserved.Eutrophication has become a serious environmental threat throughout the world. In particular, the presence of cyanobacteria toxins, especially microcystins (MCs), has become a severe problem. Inhibition of Microcystis growth in water resources is the most effective way to reduce MCs, but it is a long-term investment. In the present study, a microgel-Fe(III) complex was developed for the fast removal of MC-LR. The microgel-Fe(III) characteristics and the MC-LR removal dynamics in Milli-Q water and natural water were evaluated. The removal efficiency negatively correlated to the initial MC-LR concentration and pH value (2.0-11.5), but the kinetics was not significantly influenced. The presence of natural organic matter (NOM) in water slightly reduced MC-LR removal using microgel-Fe(III). In addition, microgel-Fe(III) removed 98.99% of MC-LR in 12 min, while for activated carbon, it took 15-24 h to reach equilibrium. Furthermore, methanol was found to regenerate the microgel-Fe(III) after MC-LR removal for at least five regeneration cycles. Finally, the microgel-Fe(III) material was made into a membrane so that MCs could be removed by filtration. Therefore, microgel-Fe(III) is an effective technology and has a great potential in removing MC-LR from drinking water resources. (C) 2011 Elsevier Ltd. All rights reserved
Support vector machines to detect physiological patterns for EEG and EMG-based human-computer interaction:a review
No full textSupport vector machines (SVMs) are widely used classifiers for detecting physiological patterns in human-computer interaction (HCI). Their success is due to their versatility, robustness and large availability of free dedicated toolboxes. Frequently in the literature, insufficient details about the SVM implementation and/or parameters selection are reported, making it impossible to reproduce study analysis and results. In order to perform an optimized classification and report a proper description of the results, it is necessary to have a comprehensive critical overview of the applications of SVM. The aim of this paper is to provide a review of the usage of SVM in the determination of brain and muscle patterns for HCI, by focusing on electroencephalography (EEG) and electromyography (EMG) techniques. In particular, an overview of the basic principles of SVM theory is outlined, together with a description of several relevant literature implementations. Furthermore, details concerning reviewed papers are listed in tables and statistics of SVM use in the literature are presented. Suitability of SVM for HCI is discussed and critical comparisons with other classifiers are reported
Use of the Choquet Integral for Combination of Classifiers in P300 Based Brain-Computer Interface
No full textOne of the key issues in the development of braincomputer
interfaces (BCIs) is the improvement of their current
information transfer rate. In order to achieve that objective at
least two aspects of BCI design should be considered: classification
accuracy and protocol specification. In this paper we
show how combination of classifiers using fuzzy measures and
the Choquet integral can be applied to the context of EEG-based
BCI and study whether its use, together with an appropriate
application protocol, can lead to an increase in the information
transfer rate
Incremental Scannerless Generalized LR Parsing
No full textThe Scannerless Generalized LR (SGLR) parsing algorithm supports the development of composed languages seamlessly but does not support incremental parsing. The Incremental Generalized LR (IGLR) parsing algorithm, on the other hand, does not support the seamless composition of languages. This thesis presents the Incremental Scannerless Generalized LR (ISGLR) parsing algorithm and investigates the effects of combining the SGLR and IGLR parsing algorithms. While the algorithmic differences are orthogonal, the fact that scannerless parsing relies on non-deterministic parsing for disambiguation has a negative impact on incrementality. Nonetheless, we show that the ISGLR parsing algorithm performs better than the batch SGLR parsing algorithm in typical scenarios. On average, the ISGLR parser can reuse 99% of a previous parse result. When parsing from scratch, the ISGLR parser has a 24% run time overhead compared to the SGLR parser, but when parsing incrementally for changes that are smaller than 1% of the input size on average, it has a 9× speedup.Successor of https://doi.org/10.1145/3359061.3361085Computer Scienc
TOXIC EFFECTS OF MICROCYSTIN-LR ON MICE ERYTHROCYTES in vitro
No full textHaematological abnormalities have been verified in patients intoxicated by microcystins (MCs) in haemodialysis unit in Caruaru, Brazil, and 60 patients died. In our previous studies, obvious anemia has been determined in rabbit after in vivo exposure to microcystins. As to the cause of the anemia, except for hematopoiesis obstacles, we hypothesized that microcystins result in erythrocyte destruction. In the present study, Kunming mice erythrocytes in vitro were incubated with 1, 10, 100 and 1000 nM microcystin-LR at 37 degrees C. Lipid peroxidation, haemolysis, cell morphology, antioxidative response and some biochemical biomarkers were measured. The results showed that the level of lipid peroxidation significantly increased in microcystin-LR treatment groups. The level of glutathione and activities of glutathione peroxidase, glutathione-S-transferase and superoxide dismutase were significantly increased after incubation with microcystin-LR at 12, 24 and 48 h. Also, significant decreases in activities of acetylcholinesterase, Na+-K+-ATPase and Ca2+-Mg2+-ATPase were observed. Obvious increases of haemolysis were determined in 10, 100 and 1000 nM groups from 12 to 48 h. Additionally, abnormal erythrocytes with bleb-bing and notched cell membrane were observed in both 100 and 1000 nM groups. It is presumed that microcystin-LR triggers lipid peroxidation of erythrocytes and oxidative stress destroys the structure of cell membrane, leading to alterations of antioxidative enzymes and biochemical indicators. Our results demonstrate that in vitro exposure to microcystin-LR resulted in damage of mice erythrocytes.Haematological abnormalities have been verified in patients intoxicated by microcystins (MCs) in haemodialysis unit in Caruaru, Brazil, and 60 patients died. In our previous studies, obvious anemia has been determined in rabbit after in vivo exposure to microcystins. As to the cause of the anemia, except for hematopoiesis obstacles, we hypothesized that microcystins result in erythrocyte destruction. In the present study, Kunming mice erythrocytes in vitro were incubated with 1, 10, 100 and 1000 nM microcystin-LR at 37 degrees C. Lipid peroxidation, haemolysis, cell morphology, antioxidative response and some biochemical biomarkers were measured. The results showed that the level of lipid peroxidation significantly increased in microcystin-LR treatment groups. The level of glutathione and activities of glutathione peroxidase, glutathione-S-transferase and superoxide dismutase were significantly increased after incubation with microcystin-LR at 12, 24 and 48 h. Also, significant decreases in activities of acetylcholinesterase, Na+-K+-ATPase and Ca2+-Mg2+-ATPase were observed. Obvious increases of haemolysis were determined in 10, 100 and 1000 nM groups from 12 to 48 h. Additionally, abnormal erythrocytes with bleb-bing and notched cell membrane were observed in both 100 and 1000 nM groups. It is presumed that microcystin-LR triggers lipid peroxidation of erythrocytes and oxidative stress destroys the structure of cell membrane, leading to alterations of antioxidative enzymes and biochemical indicators. Our results demonstrate that in vitro exposure to microcystin-LR resulted in damage of mice erythrocytes
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