julilili42/papers huggingface dataset:
The BCI competition III: validating alternative approaches to actual BCI problems
2006-06-01

A brain-computer interface (BCI) is a system that allows its users to control external devices with brain activity. Although the proof-of-concept was given decades ago, the reliable translation of user intent into device control commands is still a major challenge. Success requires the effective interaction of two adaptive controllers: the user's brain, which produces brain activity that encodes intent, and the BCI system, which translates that activity into device control commands. In order to facilitate this interaction, many laboratories are exploring a variety of signal analysis techniques to improve the adaptation of the BCI system to the user. In the literature, many machine learning and pattern classification algorithms have been reported to give impressive results when applied to BCI data in offline analyses. However, it is more difficult to evaluate their relative value for actual online use. BCI data competitions have been organized to provide objective formal evaluations of alternative methods. Prompted by the great interest in the first two BCI Competitions, we organized the third BCI Competition to address several of the most difficult and important analysis problems in BCI research. The paper describes the data sets that were provided to the competitors and gives an overview of the results.
Neural Representations of Self versus Other: Visual-Spatial Perspective Taking and Agency in a Virtual Ball-tossing Game
2006-06-01

Abstract Human self-consciousness relies on the ability to distinguish between oneself and others. We sought to explore the neural correlates involved in self-other representations by investigating two critical processes: perspective taking and agency. Although recent research has shed light on the neural processes underlying these phenomena, little is known about how they overlap or interact at the neural level. In a two-factorial functional magnetic resonance imaging (fMRI) experiment, participants played a ball-tossing game with two virtual characters (“avatars”). During an active/agency (ACT) task, subjects threw a ball to one of the avatars by pressing a button. During a passive/nonagency (PAS) task, they indicated which of the other avatars threw the ball. Both tasks were performed from a first-person perspective (1PP), in which subjects interacted from their own perspective, and a third-person perspective (3PP), in which subjects interacted from the perspective of an avatar with another location in space. fMRI analyses revealed overlapping activity in medial prefrontal regions associated with representations of one's own perspective and actions (1PP and ACT), and overlapping activity in temporal-occipital, premotor, and inferior frontal, as well as posterior parietal regions associated with representation of others' perspectives and actions (3PP and PAS). These findings provide evidence for distinct neural substrates underlying representations of the self and others and provide support for the idea that the medial prefrontal cortex crucially contributes to a neural basis of the self. The lack of a statistically significant interaction suggests that perspective taking and agency represent independent constituents of self-consciousness.
Immunologic and Clinical Responses after Vaccinations with Peptide-Pulsed Dendritic Cells in Metastatic Renal Cancer Patients
2006-06-01

Abstract A phase I trial was conducted to evaluate the feasibility, safety, and efficacy of a dendritic cell–based vaccination in patients with metastatic renal cell carcinoma (RCC). Autologous mature dendritic cells derived from peripheral blood monocytes were pulsed with the HLA-A2-binding MUC1 peptides (M1.1 and M1.2). For the activation of CD4+ T-helper lymphocytes, dendritic cells were further incubated with the PAN-DR-binding peptide PADRE. Dendritic cell vaccinations were done s.c. every 2 weeks for four times and repeated monthly until tumor progression. After five dendritic cell injections, patients additionally received three injections weekly of low-dose interleukin-2 (1 million IE/m2). The induction of vaccine-induced T-cell responses was monitored using enzyme-linked immunospot and Cr release assays. Twenty patients were included. The treatment was well tolerated with no severe side effects. In six patients, regression of the metastatic sites was induced after vaccinations with three patients achieving an objective response (one complete response, two partial responses, two mixed responses, and one stable disease). Additional four patients were stable during the treatment for up to 14 months. MUC1 peptide–specific T-cell responses in vivo were detected in the peripheral blood mononuclear cells of the six patients with objective responses. Interestingly, in patients responding to the treatment, T-cell responses to antigens not used for vaccinations, such as adipophilin, telomerase, or oncofetal antigen, could be detected, indicating that epitope spreading might occur. This study shows that MUC1 peptide–pulsed dendritic cells can induce clinical and immunologic responses in patients with metastatic RCC. (Cancer Res 2006; 66(11): 5910-8)
Brain-computer interface research at the university of south Florida cognitive psychophysiology laboratory: the P300 speller
2006-06-01

We describe current efforts to implement and improve P300-BCI communication tools. The P300 Speller first described by Farwell and Donchin (in 1988) adapted the so-called oddball paradigm (OP) as the operating principle of the brain-computer interface (BCI) and was the first P300-BCI. The system operated by briefly intensifying each row and column of a matrix and the attended row and column elicited a P300 response. This paradigm has been the benchmark in P300-BCI systems, and in the past few years the P300 Speller paradigm has been solidified as a promising communication tool. While promising, we have found that some people who have amyotrophic lateral sclerosis (ALS) would be better suited with a system that has a limited number of choices, particularly if the 6 x 6 matrix is difficult to use. Therefore, we used the OP to implement a four-choice system using the commands: Yes, No, Pass, and End; we also used three presentation modes: auditory, visual, and auditory and visual. We summarize results from both paradigms and also discuss obstacles we have identified while working with the ALS population outside of the laboratory environment.
BCI meeting 2005-workshop on clinical issues and applications
2006-06-01

This paper describes the outcome of discussions held during the Third International BCI Meeting at a workshop charged with reviewing and evaluating the current state of and issues relevant to brain-computer interface (BCI) clinical applications. These include potential BCI users, applications, validation, getting BCIs to users, role of government and industry, plasticity, and ethics.
Does Red Noise Increase or Decrease Extinction Risk? Single Extreme Events versus Series of Unfavorable Conditions
2006-06-01

Recent theoretical studies have shown contrasting effects of temporal correlation of environmental fluctuations (red noise) on the risk of population extinction. It is still debated whether and under which conditions red noise increases or decreases extinction risk compared with uncorrelated (white) noise. Here, we explain the opposing effects by introducing two features of red noise time series. On the one hand, positive autocorrelation increases the probability of series of poor environmental conditions, implying increasing extinction risk. On the other hand, for a given time period, the probability of at least one extremely bad year ("catastrophe") is reduced compared with white noise, implying decreasing extinction risk. Which of these two features determines extinction risk depends on the strength of environmental fluctuations and the sensitivity of population dynamics to these fluctuations. If extreme (catastrophic) events can occur (strong noise) or sensitivity is high (overcompensatory density dependence), then temporal correlation decreases extinction risk; otherwise, it increases it. Thus, our results provide a simple explanation for the contrasting previous findings and are a crucial step toward a general understanding of the effect of noise color on extinction risk.
Internalizing Agency of Self-Action: Perception of One's Own Hand Movements Depends on an Adaptable Prediction About the Sensory Action Outcome
2006-06-01

Extensive work on learning in reaching and pointing tasks has demonstrated high degrees of plasticity in our ability to optimize goal-directed motor behavior. However, studies focusing on the perceptual awareness of our own actions during motor adaptation are still rare. Here we present the first simultaneous investigation of sensorimotor adaptation on both levels, i.e., action and action perception. We hypothesized that self-action perception relies on internal predictions about the sensory action outcome that are updated in a way similar to that of motor control. Twenty human subjects performed out-and-back pointing movements that were fed back visually. Feedback was initially presented in spatiotemporal correspondence with respect to the actual finger position, but later rotated by a constant angle. When distorted feedback was applied repetitively, subjects' perceived pointing direction shifted in the direction of the trajectory rotation. A comparable perceptual reinterpretation was observed in control trials without visual feedback, indicating that subjects learned to predict the new visual outcome of their actions based on nonvisual, internal information. The perception of the world, however, remained unchanged. The changes in perception of one's own movements were accompanied by adaptive changes in motor performance of the same amount, i.e., a secondary motor compensation opposite to the direction of the imposed visual rotation. Our results show that the perception of one's own actions depends on adaptable internal predictions about the sensory action outcome, allowing us to attribute new sensory consequences of our actions to our own agency. Furthermore, they indicate that the updated sensory prediction can be used to optimize motor control.
Cartilage repair on magnesium scaffolds used as a subchondral bone replacement
2006-06-01

Abstract Despite the availability of surgical and non‐surgical techniques, the repair of articular cartilage lesions remains a current clinical problem. Especially for the treatment of large osteochondral cartilage defects, the replacement of the subchondral bone plate is a crucial step for optimal cartilage repair. However, no artificial implant material can yet fully restore the properties of the subchondral bone plate. For optimal cartilage tissue repair, mechanical stability for the first two months is essential. Subsequently, a rapid degradation process of the implant material would allow optimal supply of nutrition to the regenerating tissue. To this end, we investigated whether the implantation of an open porous degradable scaffold made of a magnesium alloy (AZ91) could serve as a sufficient temporary replacement of the subchondral bone plate. The results show that this alloy degrades too rapid in vivo to allow sufficient cartilage repair above the scaffold. However, the surrounding cartilage tissue was not negatively affected by the rapid degradation process and new bone formation was observed at the rim of the degrading implant. In conclusion, magnesium scaffolds degrade in vivo but the initial high corrosion rate must be reduced to allow the formation of an appropriate cartilage tissue. Future research will therefore be directed to optimized alloys and additional coating with magnesium fluorides or calcium phosphates like hydroxyapatite.
Classifying EEG and ECoG signals without subject training for fast BCI implementation: comparison of nonparalyzed and completely paralyzed subjects
2006-06-01

We summarize results from a series of related studies that aim to develop a motor-imagery-based brain-computer interface using a single recording session of electroencephalogram (EEG) or electrocorticogram (ECoG) signals for each subject. We apply the same experimental and analytical methods to 11 nonparalysed subjects (eight EEG, three ECoG), and to five paralyzed subjects (four EEG, one ECoG) who had been unable to communicate for some time. While it was relatively easy to obtain classifiable signals quickly from most of the nonparalyzed subjects, it proved impossible to classify the signals obtained from the paralyzed patients by the same methods. This highlights the fact that though certain BCI paradigms may work well with healthy subjects, this does not necessarily indicate success with the target user group. We outline possible reasons for this failure to transfer.
Hospital Volume and Neonatal Mortality Among Very Low Birth Weight Infants
2006-06-01

BACKGROUND. Very low birth weight infants (&amp;lt;1500 g) are at increased mortality risk. Data on the impact of NICU volume are sparse, in comparison with those on the level of care. We hypothesized that neonatal mortality would be higher in small NICUs (&amp;lt;36 very low birth weight admissions per year) than in large NICUs, with adjustment for volume of the delivery unit. METHODS. We analyzed population-based data from a quality assurance program in Lower Saxony (Germany). Perinatal data for almost all very low birth weight infants born in 1991 to 1999 (n = 7745) were available. Analyses were restricted to infants born at 24 to 30 weeks (n = 4379). Data validation procedures, univariate data analyses, and logistic regression models based on general estimating equations were performed. RESULTS. Neonatal mortality among infants admitted to NICUs was 12.2% in small NICUs and 10.2% in large NICUs. The mortality rate in small NICUs was increased significantly. Compared with infants from large delivery hospitals (&amp;gt;1000 births per year) and large NICUs, the adjusted odds ratio was 1.94 for neonates for whom both units were small, 1.75 for those from large delivery units but small neonatal units, and 1.16 for those for whom only the NICU was large. Stratification according to gestational age revealed the greatest impact on mortality for infants of &amp;lt;29 weeks. CONCLUSIONS. Results suggest that creating larger perinatal centers may improve perinatal health care. The volume of the NICU was associated more strongly with 28-day mortality than was the volume of the delivery hospital, and it had the largest impact on survival for infants of &amp;lt;29 weeks.
Digital soil mapping in Germany—a review
2006-06-01

Abstract Digital soil mapping as a tool to generate spatial soil information provides solutions for the growing demand for high‐resolution soil maps worldwide. Even in highly developed countries like Germany, digital soil mapping becomes essential due to the decreasing, time‐consuming, and expensive field surveys which are no longer affordable by the soil surveys of the individual federal states. This article summarizes the present state of soil survey in Germany in terms of digitally available soil data, applied digital soil mapping, and research in the broader field of pedometrics and discusses future perspectives. Based on the geomorphologic conditions in Germany, relief is a major driving force in soil genesis. This is expressed by the digital–soil mapping research which highlights the great importance of digital terrain attributes in combination with information on parent material in soil prediction. An example of digital soil mapping using classification trees in Thuringia is given as an introduction in digital soil‐class mapping based on correlations to environmental covariates within the scope of the German classification system.
Distribution and genesis of Fahlerden (Albeluvisols) in Germany
2006-06-01

Abstract Fahlerden dominate large areas of the young and old moraine landscapes of N and E Germany. Fahlerden (part of Fahlerden corresponds to Albeluvisols) and their transitional subtypes are supposed to have a higher intensity of clay illuviation than Parabraunerden (Luvisols). Besides this macroscopic feature reflecting periglacial influence, micromorphological features such as lenticular platy microstructure, vesicles, and fragments of clay coatings in Bt streaks document the initiation of Fahlerde genesis, which began in the Late Glacial. A model of Fahlerde genesis chronologically connects sedimentological and periglacial processes, vegetation development, and soil‐forming processes like decalcification, clay illuviation, and humification. The classification criterion of larger differences in clay contents between E and Bt horizons to distinguish Fahlerden from Parabraunerden needs to be reconsidered, because most Fahlerden have developed in stratified parent material in periglacially influenced landscapes. The interpretation of a soil data base listing data of both soil types distributed in Brandenburg demonstrates that the difference in clay contents between E and Bt horizons may even be smaller in Fahlerden than in Parabraunerden.
Therapies for the treatment of type 2 diabetes mellitus based on incretin action.
2006-06-01

Orally ingested glucose leads to a much higher insulin response than intravenous glucose leading to identical postprandial plasma glucose excursions. This phenomenon, termed ''incretin effect'' comprises up to 60% of the postprandial insulin secretion and is diminished in type 2 diabetes. The gastrointestinal hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) promote the incretin effect. Type 2 diabetes is characterized by an incretin defect: while GIP does not stimulate insulin secretion, GLP-1 action is still preserved under supraphysiological concentrations. GLP-1 stimulates insulin secretion only under hyperglycaemic conditions, therefore it does not cause hypoglycaemia. Furthermore, GLP-1 inhibits glucagon secretion and delays gastric emptying. In vitro and animal data demonstrated that GLP-1 increases beta cell mass by stimulating islet cell neogenesis and by inhibiting apoptosis of islets. The improvement of beta cell function can be indirectly observed from the increased insulin secretory capacity of humans receiving GLP-1. In contrast to GIP, GLP-1 may represent an attractive therapeutic method for type 2 diabetes due to its multiple effects also including the simulation of satiety in the central nervous system by acting as transmitter or by crossing the blood brain barrier. Native GLP-1 is degraded rapidly upon intravenous or subcutaneous administration and is therefore not feasible for routine therapy. Long-acting GLP-1 analogs (e.g. Liraglutide) and exendin-4 (Exenatide, Byetta) that are resistant to degradation, called ''incretin mimetics'' are approved (Exenatide, Byetta) or in clinical trials. DPP-4-inhibitors (e.g. Vildagliptin), Sitagliptin and Saxagliptin) that inhibit the enzyme DPP-4 responsible for incretin degradation are also under study.
Melanin Protects Choroidal Blood Vessels against Light Toxicity
2006-06-01

Low ocular pigmentation and high long-term exposure to bright light are believed to increase the risk of developing age-related macular degeneration (ARMD). To investigate the role of pigmentation during bright light exposure, cell damage in retinae and choroids of pigmented and non-pigmented rats were compared. Pigmented Long Evans (LE) rats and non-pigmented (albino) Wistar rats were exposed to high intensity visible light from a cold light source with 140,000 lux for 30 min. Control animals of both strains were not irradiated. The animals had their pupils dilated to prevent light absorbance by iris pigmentation. 22 h after irradiation, the rats were sacrificed and their eyes enucleated. Posterior segments, containing retina and choroid, were prepared for light and electron microscopy. Twenty different sections of specified and equal areas were examined in every eye. In albino rats severe retinal damage was observed after light exposure, rod outer segments (ROS) were shortened and the thickness of the outer nuclear layer (ONL) was significantly diminished. Choriocapillaris blood vessels were obstructed. In wide areas the retinal pigment epithelium (RPE) was absent in albino rats after irradiation. In contrast, LE rats presented much less cell damage in the RPE and retina after bright light exposure, although intra-individual differences were observed. The thickness of the ONL was almost unchanged compared to controls. ROS were shortened in LE rats, but the effect was considerably less than that seen in the albinos. Only minimal changes were found in choroidal blood vessels of pigmented rats. The RPE showed certain toxic damage, but cells were not destroyed as in the non-pigmented animals. The number of melanin granules in the RPE of LE rats was reduced after irradiation. Ocular melanin protects the retina and choroid of pigmented eyes against light-induced cell toxicity. Physical protection of iris melanin, as possible in eyes with non-dilated pupils, does not seem to play a major role in our setup. Biochemical mechanisms, like reducing oxidative intracellular stress, are more likely to be responsible for melanin-related light protection in eyes with dilated lens aperture.
Nonlinear Transmission of a Tetrabrominated Naphthalocyaninato Indium Chloride
2006-06-01

The axially substituted complex chloro indium(III) 2-tetrabromo-3-tetra-(3,5-di-tert-butylphenyloxy)naphthalocyanine [Br4(tBu2PhO)4NcInCl (1); MW = 1996] has been synthesized for the first time, and its nonlinear transmission properties have been evaluated with the Z-scan technique in both open and closed aperture configurations at 532 nm for nanosecond pulsed radiation. The tetrabrominated complex 1 displayed a larger positive nonlinear absorption coefficient when compared to an analogous nonbrominated naphthalocyanine [(tBu2PhO)8NcInCl (2); MW = 2498]. The effect of the four Br atoms on the nonlinear optical behavior of 1 is evaluated, discussed, and compared with the nonlinear optical behavior of 2. It is shown that the bromination of the naphthalocyanine ring considerably improves the limiting properties of such a system when high-intensity radiations are produced by nanosecond laser pulses at 532 nm.
Expression of Human Endogenous Gammaretroviral Sequences in Endometriosis and Ovarian Cancer
2006-06-01

Endogenous retroviruses (ERVs) probably originate from ancient germ cell infections by exogenous retroviruses. A high expression of retroviruses in reproductive tissue increases the risk of viral transmission to germ line cells. We therefore investigated the expression of human ERVs (HERVs) in normal endometrium, endometriosis, normal ovaries, and ovarian cancer. Four real-time PCRs (QPCRs) for HERV-E, HERV-I/T, HERV-H, and HERV-W, respectively, and an expression control gene were used. HERV-E RNA expression was significantly higher in endometriotic tissue (average, SD) than in normal endometrium (average, SD), both measured as ratios versus control gene expression and as. HERV-E and HERV-W RNA were higher in normal ovarian tissue than in ovarian cancer. This illustrates that HERV expression is not automatically higher in malignant tissues. The other HERV PCRs did not show expression patterns as distinctive as HERVE and HERV-W in the two kinds of reproductive tissue. A small number of candidate HERV-E loci from which the transcription took place were identified by sequencing of amplimers. The role of HERV-E and HERV-W in endometriosis merits further investigation.
Consequences of Verteporfin Photodynamic Therapy on Choroidal Neovascular Membranes
2006-06-01

Photodynamic therapy induces selective vascular damage in choroidal neovascular membranes. The effectiveness and selectivity of this treatment, however, seem to be jeopardized by a rebound effect initiated by enhanced VEGF expression in retinal pigment epithelial cells.