Fast branching algorithm for Cluster Vertex Deletion

In the family of clustering problems, we are given a set of objects (vertices of the graph), together with some observed pairwise similarities (edges). The goal is to identify clusters of similar objects by slightly modifying the graph to obtain a cluster graph (disjoint union of cliques). Hueffner et al. [Theory Comput. Syst. 2010] initiated the parameterized study of Cluster Vertex Deletion, where the allowed modification is vertex deletion, and presented an elegant O(2^k * k^9 + n * m)-time fixed-parameter algorithm, parameterized by the solution size. In our work, we pick up this line of research and present an O(1.9102^k * (n + m))-time branching algorithm

Theoretical Sensitivity Analysis for Quantitative Operational Risk Management

We study the asymptotic behavior of the difference between the values at risk VaR(L) and VaR(L+S) for heavy tailed random variables L and S for application in sensitivity analysis of quantitative operational risk management within the framework of the advanced measurement approach of Basel II (and III). Here L describes the loss amount of the present risk profile and S describes the loss amount caused by an additional loss factor. We obtain different types of results according to the relative magnitudes of the thicknesses of the tails of L and S. In particular, if the tail of S is sufficiently thinner than the tail of L, then the difference between prior and posterior risk amounts VaR(L+S) - VaR(L) is asymptotically equivalent to the expectation (expected loss) of S.Comment: 21 pages, 1 figure, 4 tables, forthcoming in International Journal of Theoretical and Applied Finance (IJTAF

Event-related desynchronization related to the anticipation of a stimulus providing knowledge of results

In the present paper, event-related desynchronization (ERD) in the alpha and beta frequency bands is quantified in order to investigate the processes related to the anticipation of a knowledge of results (KR) stimulus. In a time estimation task, 10 subjects were instructed to press a button 4 s after the presentation of an auditory stimulus. Two seconds after the response they received auditory or visual feedback on the timing of their response. Preceding the button press, a centrally maximal ERD is found. Preceding the visual KR stimulus, an ERD is present that has an occipital maximum. Contrary to expectation, preceding the auditory KR stimulus there are no signs of a modalityspecific ERD. Results are related to a thalamo-cortical gating model which predicts a correspondence between negative slow potentials and ERD during motor preparation and stimulus anticipation

Rassendiscriminatie... tenslotte is het verboden bij de wet

Contains fulltext : 3767.pdf (publisher's version ) (Open Access

SIRIUS: decomposing isotope patterns for metabolite identification†

Motivation: High-resolution mass spectrometry (MS) is among the most widely used technologies in metabolomics. Metabolites participate in almost all cellular processes, but most metabolites still remain uncharacterized. Determination of the sum formula is a crucial step in the identification of an unknown metabolite, as it reduces its possible structures to a hopefully manageable set

Desynchronization during anticipatory attention for an upcoming stimulus: A comparative EEG/MEG study

Objectives: Our neurophysiological model of anticipatory behaviour (e.g. Acta Psychol 101 (1999) 213; Bastiaansen et al., 1999a) predicts an activation of (primary) sensory cortex during anticipatory attention for an upcoming stimulus. In this paper we attempt to demonstrate this by means of event-related desynchronization (ERD). Methods: Five subjects performed a time estimation task, and were informed about the quality of their time estimation by either visual or auditory stimuli providing Knowledge of Results (KR). EEG and MEG were recorded in separate sessions, and ERD was computed in the 8± 10 and 10±12 Hz frequency bands for both datasets. Results: Both in the EEG and the MEG we found an occipitally maximal ERD preceding the visual KR for all subjects. Preceding the auditory KR, no ERD was present in the EEG, whereas in the MEG we found an ERD over the temporal cortex in two of the 5 subjects. These subjects were also found to have higher levels of absolute power over temporal recording sites in the MEG than the other subjects, which we consider to be an indication of the presence of a `tau' rhythm (e.g. Neurosci Lett 222 (1997) 111). Conclusions: It is concluded that the results are in line with the predictions of our neurophysiological model

High prevalence of missed information related on bone health in orthogeriatric patients with fragility fractures of the pelvis-an institutional register-based analysis

This is the first study that highlighted the amount of missed information related on bone health in orthogeriatric patients suffering fragility fractures of the pelvis and also evaluated its prevalence and differing etiology in the assessed patients, regarding osteoporosis and/or osteomalacia, based on laboratory and instrumental measurements. This evaluation should become a standardized procedure in the treatment of orthogeriatric patients presenting with a FFP. INTRODUCTION Fragility fractures of the pelvis (FFP) are common in orthogeriatric patients. Secondary fracture prevention regarding evaluation and treatment of an underlying osteoporosis or osteomalacia is still often neglected. The purpose of this study was to evaluate the amount of missed information related on bone health in older adult FFP patients, the prevalence of vitamin D deficiency in assessed patients, and if fracture type-dependent distribution patterns could be observed. METHODS A retrospective analysis of prospectively collected data of an institutional register was performed. Patients aged 80~years and older (n = 456) admitted with a FFP from 01/2003 until 12/2019 to a level I trauma center were included. RESULTS In 456 patients, FFP type II were leading (66.7%). Diagnostics were conducted in 37.1% of the patients regarding measurement of vitamin D levels and 21.7% regarding DXA measurements; vitamin D deficiency was observed in 62.7%, indicators for an underlying osteomalacia in 45.8%, and an osteoporosis in 46.5% of the assessed patients. CONCLUSION Although FFP are common and will increase, there is still a lack of secondary fracture prevention, starting with information related on bone health. In the assessed patients, a high prevalence of vitamin D deficiency was present, but no significant correlation between vitamin D level and type of fracture was observed. Ongoing education for varying etiology and specific treatment of these fractures is necessary, as surgical treatment was unified, but drug therapy remains different

Fibrin Glue Coating Limits Scar Tissue Formation around Peripheral Nerves

Scar tissue formation presents a significant barrier to peripheral nerve recovery in clinical practice. While different experimental methods have been described, there is no clinically available gold standard for its prevention. This study aims to determine the potential of fibrin glue (FG) to limit scarring around peripheral nerves. Thirty rats were divided into three groups: glutaraldehyde-induced sciatic nerve injury treated with FG (GA + FG), sciatic nerve injury with no treatment (GA), and no sciatic nerve injury (Sham). Neural regeneration was assessed with weekly measurements of the visual static sciatic index as a parameter for sciatic nerve function across a 12-week period. After 12 weeks, qualitative and quantitative histological analysis of scar tissue formation was performed. Furthermore, histomorphometric analysis and wet muscle weight analysis were performed after the postoperative observation period. The GA + FG group showed a faster functional recovery (6 versus 9 weeks) compared to the GA group. The FG-treated group showed significantly lower perineural scar tissue formation and significantly higher fiber density, myelin thickness, axon thickness, and myelinated fiber thickness than the GA group. A significantly higher wet muscle weight ratio of the tibialis anterior muscle was found in the GA + FG group compared to the GA group. Our results suggest that applying FG to injured nerves is a promising scar tissue prevention strategy associated with improved regeneration both at the microscopic and at the functional level. Our results can serve as a platform for innovation in the field of perineural regeneration with immense clinical potential.</p

Fibrin Glue Coating Limits Scar Tissue Formation around Peripheral Nerves

Scar tissue formation presents a significant barrier to peripheral nerve recovery in clinical practice. While different experimental methods have been described, there is no clinically available gold standard for its prevention. This study aims to determine the potential of fibrin glue (FG) to limit scarring around peripheral nerves. Thirty rats were divided into three groups: glutaraldehyde-induced sciatic nerve injury treated with FG (GA + FG), sciatic nerve injury with no treatment (GA), and no sciatic nerve injury (Sham). Neural regeneration was assessed with weekly measurements of the visual static sciatic index as a parameter for sciatic nerve function across a 12-week period. After 12 weeks, qualitative and quantitative histological analysis of scar tissue formation was performed. Furthermore, histomorphometric analysis and wet muscle weight analysis were performed after the postoperative observation period. The GA + FG group showed a faster functional recovery (6 versus 9 weeks) compared to the GA group. The FG-treated group showed significantly lower perineural scar tissue formation and significantly higher fiber density, myelin thickness, axon thickness, and myelinated fiber thickness than the GA group. A significantly higher wet muscle weight ratio of the tibialis anterior muscle was found in the GA + FG group compared to the GA group. Our results suggest that applying FG to injured nerves is a promising scar tissue prevention strategy associated with improved regeneration both at the microscopic and at the functional level. Our results can serve as a platform for innovation in the field of perineural regeneration with immense clinical potential.</p

Swiftly Computing Center Strings

Hufsky F, Kuchenbecker L, Jahn K, Stoye J, Böcker S. Swiftly Computing Center Strings. BMC Bioinformatics. 2011;12(1): 106