Composite Finite Elements for Elliptic Boundary Value Problems with Discontinuous Coefficients

In this paper, we will introduce composite finite elements for solving elliptic boundary value problems with discontinuous coefficients. The focus is on problems where the geometry of the interfaces between the smooth regions of the coefficients is very complicated. On the other hand, efficient numerical methods such as, e.g., multigrid methods, wavelets, extrapolation, are based on a multi-scale discretization of the problem. In standard finite element methods, the grids have to resolve the structure of the discontinuous coefficients. Thus, straightforward coarse scale discretizations of problems with complicated coefficient jumps are not obvious. In this paper, we define composite finite elements for problems with discontinuous coefficients. These finite elements allow the coarsening of finite element spaces independently of the structure of the discontinuous coefficients. Thus, the multigrid method can be applied to solve the linear system on the fine scale. We focus on the construction of the composite finite elements and the efficient, hierarchical realization of the intergrid transfer operators. Finally, we present some numerical results for the multigrid method based on the composite finite elements (CFE-MG

Online monitoring the isomerization of an azobenzene-based dendritic bolaamphiphile using ion mobility-mass spectrometry

Ion mobility-mass spectrometry was used to obtain detailed information about the kinetics of the light-induced cis/trans isomerization process of a new supramolecular azobenzene-based bolaamphiphile. Further experiments revealed that the investigated light-induced structural transition dramatically influences the aggregation behaviour of the molecule

Identification of Quantitative Trait Loci for Flowering Time in a Field-Grown \u3cem\u3eLolium Perene x Lolium Multiflorum\u3c/em\u3e Mapping Population

Perennial ryegrass (L. perenne) and annual, or Italian, ryegrass (L. multiflorum) are considered to be separate species by the seed trade, and are used and bred for distinct purposes. However, the two species are cross-fertile. Seed producers rely on the different flowering times of the two species to produce pure seed. Flowering times can overlap, leading to genetic mixing. Contamination of perennial ryegrass seed lots with annual types is an expensive problem for grass seed producers in western Oregon, USA

A five-year observance of changes in the cardiovascular risk profile in 505 HIV-positive individuals

Purpose: Since the introduction of antiretroviral therapy (ART) and the extension of life expectancy, HIV-infected persons have shown an increasing number of cardiovascular events. The reduction of cardiovascular risk factors becomes a new challenge in HIV care. One of the main objectives of the HIV&HEART study is to examine the development of cardiovascular risk factors and treatment of cardiovascular diseases. Methods: This study is an on-going, prospective, regional multicentre trial that was conducted to analyse the frequency and clinical course of cardiac disorders as well as cardiovascular risk factors in HIV-infected patients. 505 HIV-infected outpatients were recruited at baseline (BL) and re-examined during 5-year follow up (5YFU). Results: 84% of 505 eligible HIV-infected patients were male. The average age was 44.3±9.5 years at BL. The proportion of ART-treated patients increased from 85.7% at BL to 96.4% at 5YFU. During the 5-year observation period mean cardiovascular risk detected by Framingham score increased from 6% at BL to 10% at 5YFU. Even after adjusting for age there was a difference in the Framingham score of 2%. Between BL and 5YFU systolic blood pressure increased from 128.4±19.8 mmHg to 138.3±19.9 mmHg in spite of an intensified use of antihypertensive drugs, from 11.9% at BL to 24.0% at 5YFU. The rate of participants with adiposity, characterised by a BMI>30, increased from 7.9% at BL to 11.2% at 5YFU. Lipid-lowering therapy was applied in 10.3% of the patients at BL and in 13.9% at 5YFU. Triglycerides (TAG)≥200 mg/dl reduced from 38.9% at BL to 36.8% at 5YFU; in contrast cholesterol values≥200 mg/dl elevated from 57.8% to 61.8%. The same trend was observed in HDL≤40 mg/dl. Here we found a change from 29.2% versus 31.3%. Doing regular sports elevated from 1.9% to 3.3%. The count of smokers increased for 2.8% and also mean pack-years changes from 24 to 26.5 pack-years. Conclusion: During a 5-year period the cardiovascular risk in Framingham score increased disproportionately high in this HIV-infected cohort even after adjusting for age. There was an increasing blood pressure although an elevated use of antihypertensive therapy. There was also a tendency of elevating BMI and an increasing trend in smoking behavior. As protective facts, we found a tendency in doing sports and a decreasing TAG value during intensifying lipid-lowering therapy. Cardiovascular risk was increasing, in spite of interventions

Depth versus surface: A critical review of subdural and depth electrodes in intracranial electroencephalographic studies

Intracranial electroencephalographic (IEEG) recording, using subdural electrodes (SDEs) and stereoelectroencephalography (SEEG), plays a pivotal role in localizing the epileptogenic zone (EZ). SDEs, employed for superficial cortical seizure foci localization, provide information on two-dimensional seizure onset and propagation. In contrast, SEEG, with its three-dimensional sampling, allows exploration of deep brain structures, sulcal folds, and bihemispheric networks. SEEG offers the advantages of fewer complications, better tolerability, and coverage of sulci. Although both modalities allow electrical stimulation, SDE mapping can tessellate cortical gyri, providing the opportunity for a tailored resection. With SEEG, both superficial gyri and deep sulci can be stimulated, and there is a lower risk of afterdischarges and stimulation-induced seizures. Most systematic reviews and meta-analyses have addressed the comparative effectiveness of SDEs and SEEG in localizing the EZ and achieving seizure freedom, although discrepancies persist in the literature. The combination of SDEs and SEEG could potentially overcome the limitations inherent to each technique individually, better delineating seizure foci. This review describes the strengths and limitations of SDE and SEEG recordings, highlighting their unique indications in seizure localization, as evidenced by recent publications. Addressing controversies in the perceived usefulness of the two techniques offers insights that can aid in selecting the most suitable IEEG in clinical practice

Impact of Vitamin C on Endothelial Function and Exercise Capacity in Patients with a Fontan Circulation

Objective.  To evaluate the impact of antioxidant therapy on functional health status in Fontan‐palliated patients. Design.  Prospective, randomized, double‐blind, placebo‐controlled trial. Patients.  Fifty‐three generally asymptomatic Fontan patients. Interventions.  Patients were randomized to receive either high‐dose ascorbic acid (vitamin C) or placebo for 4 weeks. Outcome Measures.  Peripheral vascular function, as measured with endothelium‐dependent digital pulse amplitude testing (EndoPAT), and exercise capacity were assessed before and after study drug treatment. Primary outcome measures included the EndoPAT index and peripheral arterial tonometry (PAT) ratio, both validated markers of vascular function. Secondary outcome measures included peak oxygen consumption and work. Results.  Twenty‐three vitamin C‐ and 21 placebo‐assigned subjects completed the protocol (83%). Median age and time from Fontan completion were 15 (interquartile range [IQR] 11.7–18.2) and 11.9 years (IQR 9.0–15.7), respectively. Right ventricular morphology was dominant in 30 (57%). Outcome measures were similar between groups at baseline. Among all subjects, vitamin C therapy was not associated with a statistical improvement in either primary or secondary outcome measures. In subjects with abnormal vascular function at baseline, compared with placebo, vitamin C therapy more frequently resulted in normalization of the EndoPAT index (45% vs. 17%) and PAT ratio (38% vs. 13%). Conclusions.  Short‐term therapy with vitamin C does not alter endothelial function or exercise capacity in an asymptomatic Fontan population overall. Vitamin C may provide benefit to a subset of Fontan patients with abnormal vascular function.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92126/1/j.1747-0803.2011.00605.x.pd

Combining ultra-high resolution ion-mobility spectrometry with cryogenic IR spectroscopy for the study of biomolecular ions

Double-resonance spectroscopic schemes in combination with cryogenic ion traps are the go-to techniques when isomer-specific high-resolution spectra are required for analysis of molecular ions. Their limitation lies in the requirement for well-resolved, isomer-specific absorption bands as well as in the potentially time-consuming steps to identify each isomer. We present an alternative approach where isomeric species are readily separated using ion mobility spectrometry (IMS) and selected prior cryogenic spectroscopic analysis. To date, most IMS approaches suffer from relatively low resolution, however, recent technological developments in the field of travelling-wave ion mobility using structures for lossless ion manipulation (SLIM) permit the use of extremely long drift paths, which greatly enhances the resolution. We demonstrate the power of combining this type of ultra-high resolution IMS with cryogenic vibrational spectroscopy by comparing mobility-resolved IR spectra of a disaccharide to those acquired using IR-IR double resonance. This new approach is especially promising for investigation of larger molecules where spectral congestion interferes with double resonance techniques

Quantitative analysis by renormalized entropy of invasive electroencephalograph recordings in focal epilepsy

Invasive electroencephalograph (EEG) recordings of ten patients suffering from focal epilepsy were analyzed using the method of renormalized entropy. Introduced as a complexity measure for the different regimes of a dynamical system, the feature was tested here for its spatio-temporal behavior in epileptic seizures. In all patients a decrease of renormalized entropy within the ictal phase of seizure was found. Furthermore, the strength of this decrease is monotonically related to the distance of the recording location to the focus. The results suggest that the method of renormalized entropy is a useful procedure for clinical applications like seizure detection and localization of epileptic foci.Comment: 10 pages, 5 figure

Does psychopathology at admission predict the length of inpatient stay in psychiatry? Implications for financing psychiatric services

Background: The debate on appropriate financing systems in inpatient psychiatry is ongoing. In this context, it is important to control resource use in terms of length of stay (LOS), which is the most costly factor in inpatient care and the one that can be influenced most easily. Previous studies have shown that psychiatric diagnoses provide only limited justification for explaining variation in LOS, and it has been suggested that measures such as psychopathology might be more appropriate to predict resource use. Therefore, we investigated the relationship between LOS and psychopathological syndromes or symptoms at admission as well as other characteristics such as sociodemographic and clinical variables. Methods: We considered routine medical data of patients admitted to the Psychiatric University Hospital Zurich in the years 2008 and 2009. Complete data on psychopathology at hospital admission were available in 3,220 inpatient episodes. A subsample of 2,939 inpatient episodes was considered in final statistical models, including psychopathology as well as complete datasets of further measures (e.g. sociodemographic, clinical, treatment-related and psychosocial variables). We used multivariate linear as well as logistic regression analysis with forward selection procedure to determine the predictors of LOS. Results: All but two syndrome scores (mania, hostility) were positively related to the length of stay. Final statistical models showed that syndromes or symptoms explained about 5% of the variation in length of stay. The inclusion of syndromes or symptoms as well as basic treatment variables and other factors led to an explained variation of up to 25%. Conclusions: Psychopathological syndromes and symptoms at admission and further characteristics only explained a small proportion of the length of inpatient stay. Thus, according to our sample, psychopathology might not be suitable as a primary indicator for estimating LOS and contingent costs. This might be considered in the development of future costing systems in psychiatry

A Novel Locus and Candidate Gene for Familial Developmental Dyslexia on Chromosome 4q

Objective: Developmental dyslexia is a highly heritable specific reading and writing disability. To identify a possible new locus and candidate gene for this disability, we investigated a four-generation pedigree where transmission of dyslexia is consistent with an autosomal dominant inheritance pattern. Methods: We performed genome wide array-based SNP genotyping and parametric linkage analysis and sequencing analysis of protein-coding exons, exon-intron boundaries and conserved extragenic regions within the haplotype cosegregating with dyslexia in DNA from one affected and one unaffected family member. Cosegregation was confirmed by sequencing all available family members. Additionally, we analyzed 96 dyslexic individuals who had previously shown positive LOD scores on chromosome 4q28 as well as an even larger sample (n = 2591). Results: We found a single prominent linkage interval on chromosome 4q, where sequence analysis revealed a nucleotide variant in the 3' UTR of brain expressed SPRY1 in the dyslexic family member that cosegregated with dyslexia. This sequence alteration might affect the binding efficiency of the IGF2BP1 RNA-binding protein and thus influence the expression level of the SPRY1 gene product. An analysis of 96 individuals from a cohort of dyslexic individuals revealed a second heterozygous variant in this gene, which was absent in the unaffected sister of the proband. An investigation of the region in a much larger sample further found a nominal p-value of 0.0016 for verbal short-term memory (digit span) in 2,591 individuals for a neighboring SNV. After correcting for the local number of analyzed SNVs, and after taking into account linkage disequilibrium, we found this corresponds to a p-value of 0.0678 for this phenotype. Conclusions: We describe a new locus for familial dyslexia and discuss the possibility that SPRY1 might play a role in the etiology of a monogenic form of dyslexia