Zephyr bioharness in de praktijk

Een te hoge fysieke belasting bij (top)sporters en brandweerpersoneel kan op de lange termijn leiden tot overbelasting. In het revalidatie proces kan het de terugkeer naar het veld vertragen. Daarom is het nauwkeurig monitoren van de fysieke belasting erg belangrijk. Het Zephyr BioHarness lijkt hiervoor een geschikt instrument omdat het in staat is om verschillende fysiologische variabelen tegelijkertijd te meten. In dit rapport worden vier projecten besproken waarin de fysieke belasting gemeten is met het Zephyr BioHarness: (I) effect van veldgrootte op de belasting bij jonge talentvolle voetballers van FC Groningen, (II) overeenkomsten in belasting tussen oefeningen/sporten en uitrukken bij de professionele brandweer, (III) overeenkomsten tussen geplande belasting van fysiotherapeuten met daadwerkelijk belasting bij veldrevalidatie na een blessure (IV) validatie van Zensorium Tinké

sklvq:Scikit Learning Vector Quantization

The sklvq package is an open-source Python implementation of a set of learning vector quantization (LVQ) algorithms. In addition to providing the core functionality for the GLVQ, GMLVQ, and LGMLVQ algorithms, sklvq is distinctive by putting emphasis on its modular and customizable design. Not only resulting in a feature-rich implementation for users but enabling easy extensions of the algorithms for researchers. The theory behind this design is described in this paper. To facilitate adoptions and inspire future contributions, sklvq is publicly available on Github (under the BSD license) and can be installed through the Python package index (PyPI). Next to being well-covered by automated testing to ensure code quality, it is accompanied by detailed online documentation. The documentation covers usage examples and provides an in-depth API including theory and scientific references

Biosynthesis of lanthionine-constrained agonists of G protein-coupled receptors

The conformation with which natural agonistic peptides interact with G protein-coupled receptor(s) (GPCR(s)) partly results from intramolecular interactions such as hydrogen bridges or is induced by ligand-receptor interactions. The conformational freedom of a peptide can be constrained by intramolecular cross-links. Conformational constraints enhance the receptor specificity, may lead to biased activity and confer proteolytic resistance to peptidic GPCR agonists. Chemical synthesis allows to introduce a variety of cross-links into a peptide and is suitable for bulk production of relatively simple lead peptides. Lanthionines are thioether bridged alanines of which the two alanines can be introduced at different distances in chosen positions in a peptide. Thioether bridges are much more stable than disulfide bridges. Biosynthesis of lanthionine-constrained peptides exploiting engineered Gram-positive or Gram-negative bacteria that contain lanthionine-introducing enzymes constitutes a convenient method for discovery of lanthionine-stabilized GPCR agonists. The presence of an N-terminal leader peptide enables dehydratases to dehydrate serines and threonines in the peptide of interest after which a cyclase can couple the formed dehydroamino acids to cysteines forming (methyl)lanthionines. The leader peptide also guides the export of the formed lanthionine-containing precursor peptide out of Gram-positive bacteria via a lanthipeptide transporter. An engineered cleavage site in the C-terminus of the leader peptide allows to cleave off the leader peptide yielding the modified peptide of interest. Lanthipeptide GPCR agonists are an emerging class of therapeutics of which a few examples have demonstrated high efficacy in animal models of a variety of diseases. One lanthipeptide GPCR agonist has successfully passed clinical Phase Ia.</p

Having Fun in Learning Formal Specifications

There are many benefits in providing formal specifications for our software. However, teaching students to do this is not always easy as courses on formal methods are often experienced as dry by students. This paper presents a game called FormalZ that teachers can use to introduce some variation in their class. Students can have some fun in playing the game and, while doing so, also learn the basics of writing formal specifications in the form of pre- and post-conditions. Unlike existing software engineering themed education games such as Pex and Code Defenders, FormalZ takes the deep gamification approach where playing gets a more central role in order to generate more engagement. This short paper presents our work in progress: the first implementation of FormalZ along with the result of a preliminary users' evaluation. This implementation is functionally complete and tested, but the polishing of its user interface is still future work

Physical activity in non-frail and frail older adults

Introduction: Physical activity (PA) is important for healthy ageing. Better insight into objectively measured PA levels in older adults is needed, since most previous studies employed self-report measures for PA assessment, which are associated with overestimation of PA. Aim: This study aimed to provide insight in objectively measured indoor and outdoor PA of older adults, and in PA differences by frailty levels. Methods: Data were collected among non-frail (N = 74) and frail (N = 10) subjects, aged 65 to 89 years. PA, measured for seven days with accelerometers and GPS-devices, was categorized into three levels of intensity (sedentary, light, and moderate-to-vigorous PA). Results: Older adults spent most time in sedentary and light PA. Subjects spent 84.7%, 15.1% and 0.2% per day in sedentary, light and moderate-to-vigorous PA respectively. On average, older adults spent 9.8 (SD 23.7) minutes per week in moderate-to-vigorous activity, and 747.0 (SD 389.6) minutes per week in light activity. None of the subjects met the WHO recommendations of 150 weekly minutes of moderate-to-vigorous PA. Age-, sex- and health status-adjusted results revealed no differences in PA between non-frail and frail older adults. Subjects spent significantly more sedentary time at home, than not at home. Non-frail subjects spent significantly more time not at home during moderate-to-vigorous activities, than at home. Conclusions: Objective assessment of PA in older adults revealed that most PA was of light intensity, and time spent in moderate-to-vigorous PA was very low. None of the older adults met the World Health Organization recommendations for PA. These levels of MVPA are much lower than generally reported based on self-reported PA. Future studies should employ objective methods, and age specific thresholds for healthy PA levels in older adults are needed. These results emphasize the need for effective strategies for healthy PA levels for the growing proportion of older adults

FDG-PET combined with learning vector quantization allows classification of neurodegenerative diseases and reveals the trajectory of idiopathic REM sleep behavior disorder

Background and Objectives 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) combined with principal component analysis (PCA) has been applied to identify disease-related brain patterns in neurodegenerative disorders such as Parkinson’s disease (PD), Dementia with Lewy Bodies (DLB) and Alzheimer’s disease (AD). These patterns are used to quantify functional brain changes at the single subject level. This is especially relevant in determining disease progression in idiopathic REM sleep behavior disorder (iRBD), a prodromal stage of PD and DLB. However, the PCA method is limited in discriminating between neurodegenerative conditions. More advanced machine learning algorithms may provide a solution. In this study, we apply Generalized Matrix Learning Vector Quantization (GMLVQ) to FDG-PET scans of healthy controls, and patients with AD, PD and DLB. Scans of iRBD patients, scanned twice with an approximate 4 year interval, were projected into GMLVQ space to visualize their trajectory. Methods We applied a combination of SSM/PCA and GMLVQ as a classifier on FDG-PET data of healthy controls, AD, DLB, and PD patients. We determined the diagnostic performance by performing a ten times repeated ten fold cross validation. We analyzed the validity of the classification system by inspecting the GMLVQ space. First by the projection of the patients into this space. Second by representing the axis, that span this decision space, into a voxel map. Furthermore, we projected a cohort of RBD patients, whom have been scanned twice (approximately 4 years apart), into the same decision space and visualized their trajectories. Results The GMLVQ prototypes, relevance diagonal, and decision space voxel maps showed metabolic patterns that agree with previously identified disease-related brain patterns. The GMLVQ decision space showed a plausible quantification of FDG-PET data. Distance traveled by iRBD subjects through GMLVQ space per year (i.e. velocity) was correlated with the change in motor symptoms per year (Spearman’s rho =0.62, P=0.004). Conclusion In this proof-of-concept study, we show that GMLVQ provides a classification of patients with neurodegenerative disorders, and may be useful in future studies investigating speed of progression in prodromal disease stages