Effects of P300-based BCI use on reported presence in a virtual environment

Brain-computer interfaces (BCIs) are becoming more and more popular as an input device for virtual worlds and computer games. Depending on their function, a major drawback is the mental workload associated with their use and there is significant effort and training required to effectively control them. In this paper, we present two studies assessing how mental workload of a P300-based BCI affects participants" reported sense of presence in a virtual environment (VE). In the first study, we employ a BCI exploiting the P300 event-related potential (ERP) that allows control of over 200 items in a virtual apartment. In the second study, the BCI is replaced by a gaze-based selection method coupled with wand navigation. In both studies, overall performance is measured and individual presence scores are assessed by means of a short questionnaire. The results suggest that there is no immediate benefit for visualizing events in the VE triggered by the BCI and that no learning about the layout of the virtual space takes place. In order to alleviate this, we propose that future P300-based BCIs in VR are set up so as require users to make some inference about the virtual space so that they become aware of it,which is likely to lead to higher reported presence

Multimodal Retinal Vessel Analysis in CADASIL Patients

Purpose To further elucidate retinal findings and retinal vessel changes in Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) patients by means of high resolution retinal imaging. Methods 28 eyes of fourteen CADASIL patients and an equal number of control subjects underwent confocal scanning laser ophthalmoscopy (cSLO), spectral-domain optical coherence tomography (SD-OCT), retinal nerve fibre layer (RNFL) measurements, fluorescein and indocyanine angiography. Three vessel measurement techniques were applied: RNFL thickness, a semiautomatic software tool based on cSLO images and manual vessel outlining based on SD- OCT. Results Mean age of patients was 56.2±11.6 years. Arteriovenous nicking was present in 22 (78.6%) eyes and venous dilation in 24 (85.7%) eyes. Retinal volume and choroidal volume were 8.77±0.46 mm3 and 8.83±2.24 mm3. RNFL measurements showed a global increase of 105.2 µm (Control group: 98.4 µm; p = 0.015). Based on semi-automatic cSLO measurements, maximum diameters of arteries and veins were 102.5 µm (106.0 µm; p = 0.21) and 128.6 µm (124.4 µm; p = 0.27) respectively. Manual SD-OCT measurements revealed significantly increased mean arterial 138.7 µm (125.4 µm; p<0.001) and venous 160.0 µm (146.9; p = 0.003) outer diameters as well as mean arterial 27.4 µm (19.2 µm; p<0.001) and venous 18.3 µm (15.7 µm; p<0.001) wall thicknesses in CADASIL patients. Conclusions The findings reflect current knowledge on pathophysiologic changes in vessel morphology in CADASIL patients. SD-OCT may serve as a complementary tool to diagnose and follow-up patients suffering from cerebral small-vessel diseases

Effect of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on N-turnover, the N2_{2}O reductase-gene nosZ and N2_{2}O:N2_{2} partitioning from agricultural soils

Nitrification inhibitors (NIs) have been shown to reduce emissions of the greenhouse gas nitrous oxide (N$_{2}$O) from agricultural soils. However, their N$_{2}$O reduction efficacy varies widely across different agro-ecosystems, and underlying mechanisms remain poorly understood. To investigate effects of the NI 3,4-dimethylpyrazole-phosphate (DMPP) on N-turnover from a pasture and a horticultural soil, we combined the quantification of N$_{2}$ and N$_{2}$O emissions with $^{15}$N tracing analysis and the quantification of the N$_{2}$O-reductase gene (nosZ) in a soil microcosm study. Nitrogen fertilization suppressed nosZ abundance in both soils, showing that high nitrate availability and the preferential reduction of nitrate over N$_{2}$O is responsible for large pulses of N$_{2}$O after the fertilization of agricultural soils. DMPP attenuated this effect only in the horticultural soil, reducing nitrification while increasing nosZ abundance. DMPP reduced N$_{2}$O emissions from the horticultural soil by >50% but did not affect overall N$_{2}$ + N$_{2}$O losses, demonstrating the shift in the N$_{2}$O:N$_{2}$ ratio towards N$_{2}$ as a key mechanism of N$_{2}$O mitigation by NIs. Under non-limiting NO$_{3}$$^{-}$ availability, the efficacy of NIs to mitigate N$_{2}$O emissions therefore depends on their ability to reduce the suppression of the N$_{2}$O reductase by high NO$_{3}$$^{-}$ concentrations in the soil, enabling complete denitrification to N$_{2}$

Criteria for Blood Vessel Discrimination

Introduction The diagnostic potential of optical coherence tomography (OCT) in neurological diseases is intensively discussed. Besides the sectional view of the retina, modern OCT scanners produce a simultaneous top-view confocal scanning laser ophthalmoscopy (cSLO) image including the option to evaluate retinal vessels. A correct discrimination between arteries and veins (labeling) is vital for detecting vascular differences between healthy subjects and patients. Up to now, criteria for labeling (cSLO) images generated by OCT scanners do not exist. Objective This study reviewed labeling criteria originally developed for color fundus photography (CFP) images. Methods The criteria were modified to reflect the cSLO technique, followed by development of a protocol for labeling blood vessels. These criteria were based on main aspects such as central light reflex, brightness, and vessel thickness, as well as on some additional criteria such as vascular crossing patterns and the context of the vessel tree. Results and Conclusion They demonstrated excellent inter-rater agreement and validity, which seems to indicate that labeling of images might no longer require more than one rater. This algorithm extends the diagnostic possibilities offered by OCT investigations

Iatrogene Netzhautdefekte nach intravitrealer operativer Medikamenteneingabe

Hintergrund Intravitreale operative Medikamenteneingaben (IVOM) stellen einen der häufigsten Eingriffe in der Medizin dar. Das Risikoprofil ist gering. Neben intraokularen Drucksteigerungen zählen insbesondere erregerbedingte Endophthalmitiden, Glaskörperblutungen und rhegmatogene Netzhautablösungen zu den gängigen Komplikationen. Darüber hinaus wurden auch einzelne Fälle von Linsenverletzungen sowie peripheren Netzhautdefekten und Makulaforamina in Assoziation mit vitreoretinalen Traktionen beschrieben. In der hier vorliegenden Fallserie berichten wir über scharfe iatrogene Netzhaut- bzw. Makulaverletzungen. Methoden Multizentrische Fallsammlung von IVOM-Patienten mit iatrogenen Netzhautdefekten, retrospektiv über den Zeitraum 2016 bis 2023. Ergebnisse Es konnten 9 Fälle (72 Jahre ± 8,1, 3 Augen pseudophak) mit einem iatrogenen retinalen Trauma nach IVOM zur Therapie einer neovaskulären altersbedingten Makuladegeneration (nAMD) dokumentiert werden. Während in 6 Fällen scharfe Verletzungen innerhalb der Makula vorlagen, waren die Läsionen in den anderen Fällen extramakulär lokalisiert. Schlussfolgerungen Iatrogene Netzhaut- und Makulaverletzungen sind seltene Komplikationen im Rahmen der IVOM und bei sachgemäßer Durchführung insbesondere mit Blick auf die Kanülenverwendung und die Wahl des Limbusabstands vermeidbar

Treatment with Octreotide in Patients with Well-Differentiated Neuroendocrine Tumors of the Ileum: Prognostic Stratification with Ga-68-DOTA-TATE Positron Emission Tomography

We investigated the use of Ga-68-DOTA-Tyr(3)-octreotate (Ga-68-DOTA-TATE) positron emission tomography (PET) and standardized uptake values (SUVs) to predict the effectiveness of treatment with the somatostatin analogue octreotide acetate (Sandostatin LAR) in patients with neuroendocrine tumors (NETs). Thirty patients with well-differentiated NETs of the ileum (grades G1 and G2) were studied with Ga-68-DOTA-TATE. The average SUV of a 50% isocontour volume of interest covering the lesion with maximum uptake (SUVmean) and the maximum SUV (SUVmax) were determined. Patients were followed up, and the time to progression was recorded. Twenty-one patients showed progressive disease at the end of the study;nine patients had stable disease. The median progression-free survival (PFS) was 51.0 weeks (95% confidence interval [CI] 26.4-75.6). A cutoff for the SUVmax of 29.4 and for the SUVmean of 20.3 could separate between patients with a long PFS (69.0 weeks; 95% CI 9.8-128.2) and a short PFS (26.0 weeks; 95% CI 8.7-43.3) response to octreotide acetate therapy. Patients with high radiotracer uptake had significantly higher PFS with a 2.9-fold higher chance for stable disease after 45 weeks;however, the prognostic performance of SUVmax on an individual basis was poor, with a sensitivity of 75% and a specificity of 64%. SUVmax and SUVmean of NET tumor lesions in Ga-68-DOTA-TATE PET are important prognostic indices for predicting the response to therapy with octreotide acetate

Anti-hLAMP2-antibodies and dual positivity for anti-GBM and MPO-ANCA in a patient with relapsing pulmonary-renal syndrome

Background Pulmonary-renal syndrome associated with anti-glomerular basement membrane (GBM) antibodies, also known as Goodpasture's syndrome, is a rare but acute and life-threatening condition. One third of patients presenting as anti-GBM antibody positive pulmonary-renal syndrome or rapidly progressive glomerulonephritis are also tested positive for anti-neutrophil cytoplasmic antibodies (ANCA). Whilst anti-GBM disease is considered a non-relapsing condition, the long-term course of double-positive patients is less predictable. Case Presentation We report a patient with such dual positivity, who presented with pulmonary hemorrhage, crescentic glomerulonephritis and membranous nephropathy. Plasmapheresis in combination with immunosuppresive therapy led to a rapid remission but the disease relapsed after two years. The serum of the patient was tested positive for antibodies to human lysosomal membrane protein 2 (hLAMP2), a novel autoantigen in patients with active small-vessel vasculitis (SVV). The anti-hLAMP2 antibody levels correlated positively with clinical disease activity in this patient. Conclusion We hypothesize that this antibody may indicate a clinical course similar to ANCA-associated vasculitis in double-positive patients. However, this needs to be confirmed on comprehensive patient cohorts

Review of the BCI Competition IV

The BCI competition IV stands in the tradition of prior BCI competitions that aim to provide high quality neuroscientific data for open access to the scientific community. As experienced already in prior competitions not only scientists from the narrow field of BCI compete, but scholars with a broad variety of backgrounds and nationalities. They include high specialists as well as students. The goals of all BCI competitions have always been to challenge with respect to novel paradigms and complex data. We report on the following challenges: (1) asynchronous data, (2) synthetic, (3) multi-class continuous data, (4) session-to-session transfer, (5) directionally modulated MEG, (6) finger movements recorded by ECoG. As after past competitions, our hope is that winning entries may enhance the analysis methods of future BCIs.BMBF, 01IB001A, LOKI - Lernen zur Organisation komplexer Systeme der Informationsverarbeitung - Lernen im Kontext der SzenenanalyseBMBF, 01GQ0850, Bernstein Fokus Neurotechnologie - Nichtinvasive Neurotechnologie für Mensch-Maschine InteraktionEC/FP7/224631/EU/Tools for Brain-Computer Interaction/TOBIEC/FP7/216886/EU/Pattern Analysis, Statistical Modelling and Computational Learning 2/PASCAL2BMBF, 01GQ0420, Verbundprojekt: Bernstein-Zentrum für Neural Dynamics, Freiburg - CNDFBMBF, 01GQ0761, Bewegungsassoziierte Aktivierung - Dekodierung bewegungsassoziierter GehirnsignaleBMBF, 01GQ0762, Bewegungsassoziierte Aktivierung - Gehirn- und Maschinenlerne