julilili42/papers huggingface dataset:
Detection and removal of stimulation artifacts in electroencephalogram recordings
2011-08-01

Stimulation artifacts are short-duration, high-amplitude spikes which can be observed in electroencephalogram (EEG) recordings whenever surface functional electrical stimulation (FES) is applied during recordings. Stimulation artifacts are of non-physiologic origin and hence have to be removed before analysis of the EEG can take place. In this paper, algorithms for the detection and removal of stimulation artifacts are presented. The algorithms require only little computational resources and can be applied online, while signals are recorded. Therefore, the algorithms are suitable for applications such as online control of FES based neuroprostheses by a brain-computer interface. Tests are performed with datasets recorded from two subjects for artifact durations ranging from 0.5 ms to 10 ms. After application of the artifact removal algorithms the signal-to-noise ratio of the reconstructed signals ranges from 15 dB to 45 dB, depending on the duration of artifacts and the type of algorithm.
Anthropometric within-country Inequality and the Estimation of Skill Premia with Anthropometric Indicators
2011-08-01

Summary We provide a literature review of anthropometric studies of within-country inequality. Then we discuss the relationship between skill premia and inequality indicators based on height variation. Skill premia describe the wage gap between an unskilled and a skilled building worker, while height CVs (coefficient of height variation) display the variance in net nutrition. We find that the two measures are correlated and that CV values are suitable to estimate skill premia. We supplement the existing literature by an additional tool, namely the estimation of skill premia based on the coefficient of height variation.
Does Teaching Method Affect Students’ Perceptions Regarding Communication Patterns in Pediatric Dentistry? A Comparison of Lecture and Video Methods
2011-08-01

The purpose of this study was to determine whether dental students’ perceptions regarding six communication patterns for use in pediatric dentistry differed depending on whether they were taught by lecturing or by video‐based teaching. Prior to the introduction of interpersonal skills in a clinical course in pediatric dentistry, four consecutive cohorts of students (n=107) in a German dental school were divided equally into two groups. Group one (n=57) was taught by video sequences and group two (n=50) by conventional lecture. Six communication patterns were presented: involvement of the child's toy(s), speaking in positive phrases, mentioning a personal aspect, recalling positive behavior of the patient, addressing fear verbally, and complimenting the patient. Immediately after the presentation, students were asked by means of a questionnaire about their assessment of and intentions regarding the clinical application of the communication patterns presented. After completion of the course, they were asked about the communication patterns that had been used. There were significant differences for three communication patterns in favor of video‐based teaching (p&lt;0.05); there were no significant differences regarding the intention for clinical application and the actual clinical application. In this study, students perceived differences between video‐based teaching and lecturing regarding ease of use, but they did not seem to benefit from one method over the other regarding clinical application.
Scuba-Dive-Related Changes in Heart Rate in Children
2011-08-01

The purpose of this study was to monitor heart rate (HR) and rhythm during open water SCUBA dives. Nine children performed 25-min open water SCUBA dives to 8 m depth. Before, during and after these dives, ECG was recorded. Compared with predive heart rate, heart rate declined by -24 ± 8% (range -36%; -15%) during the dive. In some children a further decline in HR was observed within the last minutes of the dive. Older and taller subjects and those with a high initial HR showed a more pronounced decline in HR. Furthermore singular supraventricular and ventricular extrasystoles were observed in some children. Immersion as well as facial and skin cooling presumably account for the initial decline in heart rate. A further drop in HR within the last minutes of the dive might be related to mild hypothermia. Single supraventricular and ventricular extrasystoles might occur in healthy children during dives.
In vitro study of titanium nitride electrodes for neural stimulation
2011-08-01

For neural stimulation, reliable high density charge transfer into tissue is required. One electrode material for these applications is titanium nitride (TiN). In this paper, a method for lifetime analysis of TiN electrodes is discussed. Our method significantly differs from open literature. The tests were run for much longer durations. Special attention was paid to the optical appearance and electrode voltage response to different input current pulses. According to our investigations, TiN electrodes are able to deliver at most 0.2 mC/cm(2) charge density for square shaped electrodes with 50 μm × 50 μm dimensions in safe operation, which is less compared to previous reports. The safe operation window for TiN was confirmed to be ± 1 V in terms of electrode potential with the counter electrode considered as reference. We found that the shape of the waveform does not affect electrode lifetime. Our measurements show that rectangular voltage waveforms inject the most amount of charge into the electrodes compared to other shapes. This makes rectangular electrode voltage signals optimal for highest charge injection at a given lifetime. In our case with square electrodes, the absolute electrode potential is found to be the more important parameter in electrode lifetime, compared to Helmholtz capacitor voltage drop.
Emulating human observers with bayesian binning
2011-08-01

Natural body movements arise in the form of temporal sequences of individual actions. During visual action analysis, the human visual system must accomplish a temporal segmentation of the action stream into individual actions. Such temporal segmentation is also essential to build hierarchical models for action synthesis in computer animation. Ideally, such segmentations should be computed automatically in an unsupervised manner. We present an unsupervised segmentation algorithm that is based on Bayesian Binning (BB) and compare it to human segmentations derived from psychophysical data. BB has the advantage that the observation model can be easily exchanged. Moreover, being an exact Bayesian method, BB allows for the automatic determination of the number and positions of segmentation points. We applied this method to motion capture sequences from martial arts and compared the results to segmentations provided by humans from movies that showed characters that were animated with the motion capture data. Human segmentation was then assessed by an interactive adjustment paradigm, where participants had to indicate segmentation points by selection of the relevant frames. Results show a good agreement between automatically generated segmentations and human performance when the trajectory segments between the transition points were modeled by polynomials of at least third order. This result is consistent with theories about differential invariants of human movements.
Phase plane based identification of fetal heart rate patterns
2011-08-01

Using a phase plane analysis (PPA) of the spatial spread of trajectories of the fetal heart rate and its time-derivative we characterize the fetal heart rate patterns (fHRP) as defined by Nijhuis. For this purpose, we collect 22 fetal magnetocardiogram using a 151 SQUID system from 22 low-risk fetuses in gestational ages ranging from 30 to 37 weeks. Each study lasted for 30 minutes. After the attenuation of the maternal cardiac signals, we identify the R waves using an adaptive Hilbert transform approach and calculate the fetal heart rate. On these datasets, we apply the proposed approach and the traditionally used approaches such as standard deviation of the normal to normal intervals (SDNN) and root mean square of the successive difference (RMSSD). Heart rate patterns are scored by an expert using Nijhuis criteria and revealed A, B, and D patterns. A receiver operator characteristic (ROC) curve is used to assess the performance of the metric to differentiate the different patterns. Results showed that only PPA was able to differentiate all pairs of fHRP with high performance.
Conduction velocity of the uterine contraction in serial magnetomyogram (MMG) data: Event based simulation and validation
2011-08-01

We propose a novel approach to calculate the conduction velocity (CV) of the uterine contraction bursts in magnetomyogram (MMG) signals measured using a multichannel SQUID array. For this purpose, we partition the sensor coordinates into four different quadrants and identify the contractile bursts using a previously proposed Hilbert-wavelet transform approach. If contractile burst is identified in more than one quadrant, we calculate the center of gravity (CoG) in each quadrant for each time point as the sum of the product of the sensor coordinates with the Hilbert amplitude of the MMG signals normalized by the sum of the Hilbert amplitude of the signals over all sensors. Following this we compute the delay between the CoGs of all (six) possible quadrant pairs combinations. As a first step, we validate this approach by simulating a stochastic model based on independent second-order autoregressive processes (AR2) and we divide them into 30 second disjoint windows and insert burst activity at specific time instances in preselected sensors. Also we introduce a lag of 5 ± 1 seconds between different quadrants. Using our approach we calculate the CoG of the signals in a quadrant. To this end, we compute the delay between CoGs obtained from different quadrants and show that our approach is able to reliably capture the delay incorporated in the model. We apply the proposed approach to 19 serial MMG data obtained from two subjects and show an increase in the CV as the subjects approached labor.
T-cell epitope prediction based on self-tolerance
2011-08-01

T-cell epitopes, i.e., peptides capable of inducing a T-cell mediated immune response, represent suitable components for vaccines against infectious diseases and cancer. The development of accurate T-cell epitope prediction methods is thus of great interest to immunologists and the pharmaceutical industry. Whether a particular peptide is a T-cell epitope depends on the availability of (a) an MHC molecule capable of presenting the peptide on the cell surface and (b) a suitable T cell. In order to ensure self-tolerance of the immune system, T cells reactive to self-peptides are eliminated via negative selection processes. The composition of the T-cell repertoire thus depends on the host proteome. These complex dependencies along with a lack of data render T-cell epitope prediction a rather challenging problem. It is commonly reduced to the simpler MHC binding prediction problem.
The influence of removal of primary tumor on incidence and phenotype of circulating tumor cells in primary breast cancer
2011-08-01

Recent studies have shown that the detection of circulating tumor cells (CTC) pre- and postoperatively in the peripheral blood of primary breast cancer patients may be an indicator for poor survival. This study aimed to investigate the influence of removal of the primary tumor on incidence and phenotype of circulating tumor cells in primary breast cancer.
Detection of motor planning and suppression with the help of electroencephalography
2011-08-01

The aim of this study was to investigate, if it is possible to detect brain activity related to motor planning and suppression with the help of Electroencephalograms (EEG), the ultimate goal being, to simultaneously measure EEG and functional magnetic resonance imaging (fMRI). Towards this end we engaged a delayed response task from an earlier fMRI study, thereby ensuring, as a first step, that the results of both EEG and fMRI would be directly comparable. Motor preparatory signals were recorded in seven subjects using 10-20-system fMRI compatible EEG equipment. The a and p frequency bands of the EEG recordings were analyzed first individually and then on the group level. Using a non-parametric statistical test, significant clusters relating to motor planning were mainly found over the motor and posterior parietal cortex of the right hemisphere. Activity corresponding with motor suppression was exhibited over the parietal and occipital cortex, located mainly medially for the lower p band (13-20 Hz) and extended towards the right hemisphere for the a band. Active regions corresponded well to the ones revealed in our previous fMRI study. Simultaneous EEG and fMRI of this task in the future could thus provide us with combined information on timing (EEG), locality (fMRI) and activity characteristics (both) during motor planning and suppression.
Standard ERG equipment can be used to monitor functionality of retinal implants
2011-08-01

Identifying whether or not a retinal implant has malfunctioned after implantation is crucial for safety and efficacy testing in preclinical animal studies and clinical testing in human volunteers. Technical failure can lead to charge injection to areas other than the retina leading to a misjudgment of safety considerations or psychophysical results. This study assessed the feasibility of using standard ERG recordings for the detection of failure of a subretinal implant in-situ using a porcine model. Corneally recorded potentials were compared before and after introduction of damage to the implant leading to failure to deliver charges to the retina. The recorded signal decreased by up to 173% following induced damage to the implant. This shows that standard ERG equipment can be used to monitor if a malfunction occurred in animal testing and can also be applicable in clinical trials.
Deutschland als Weltmeister der Steuerliteratur? Fallstudie einer Legende
2011-08-01

Abstract This paper analyzes the production of tax literature in Germany empirically. It provides evidence to reject the argument made by politicians and the media that Germany produces three quarters of the global tax literature. It also finds that regarding the length of the tax code and the actual costs of declaring taxes, Germany is middle of the class globally. Using a case study, the paper analyzes the motives of authors of tax literature. The evidence shows that most publications are not motivated by generating knowledge, but by self-marketing, lobbying, and personal satisfaction. Overall, publications on a specific topic follow a pattern of decreasing (rather than increasing) quality over time. These repeated publications without generation of incremental knowledge are due to the organization of the market for publications in Germany, but unrelated to features of the tax system.
Four new kaempferol glycosides from the leaves of Brugmansia suaveolens
2011-08-01

Brugmansia suaveolens (Humb. & Bonpl. ex Willd.) Bercht. & C. Presl (Syn. Datura suaveolens; Common name: Angel's trumpet) is a flouring shrub of Solanaceae family and it is native from coastal regions of the rainforest in Southeast Brazil. This plant has been investigated due to its inflammatory and wound healing activities [1] and mainly due to the presence of alkaloids [2]. Nevertheless, only few studies related the characterization of flavonoid glycosides [3]. This prompted us to investigate the ethanolic extract prepared from its leaves.
On the genesis of multinational foreign affiliate networks
2011-08-01

Multinational enterprises (MNEs) develop their networks of foreign affiliates gradually over time. Instead of exploring all profitable opportunities immediately, they first establish themselves in their home countries and then enter new markets stepwise. We argue that this behavior is driven by uncertainty concerning a firm's success in new markets. After entry, the firm collects information which is used to update its beliefs about its performance in a market. As conditions in different markets are correlated, the information gathered in one of them can also be used to update beliefs elsewhere – with the degree of correlation depending on issues such as the geographical or cultural distance between markets. This correlated learning may render it optimal to enter markets sequentially – investment in market A is only followed by entry in market B if the firm was sufficiently successful in A. The prediction that firms start their expansion in markets that are closer to their home base and then proceed step by step is supported by our empirical analysis, which features the universe of foreign affiliates held by German multinationals. Based on a rich set of benchmark estimates and sensitivity checks, we identify correlated learning across markets beyond alternative explanations as a key driver of gradualism in the genesis of MNEs' foreign affiliate networks.
A novel pathway of cGMP
2011-08-01

Background Cardiac atrial natriuretic peptide (ANP) regulates arterial blood pressure, moderates cardiomyocyte growth, and stimulates angiogenesis and metabolism. ANP binds to the transmembrane guanylyl cyclase (GC) receptor, GCA to exert its diverse functions. This involves a cGMPdependent signaling pathway preventing pathological [Ca]i raises in myocytes. In chronic cardiac hypertrophy, however, ANP levels are markedly increased and GC-A/cGMP responses to ANP are blunted due to receptor desensitization.
Antitumor activity of zoledronic acid in primary breast cancer cells determined by the ATP tumor chemosensitivity assay
2011-08-01

The NeoAzure study has demonstrated that the use of the bisphosphonate zole-dronate in the neoadjuvant setting increases the rate of complete response in primary breast cancer and therefore indicates direct antitumor activity (Coleman et al. 2010). The purpose of this study was to compare the antitumor effect of zolendronic acid with standard chemotherapy in primary breast cancer cells using ATP-tumor chemosensitivity assay (ATP-TCA).
A novel suicide gene-expressing oncolytic measles vaccine virus for the treatment of hepatocellular carcinoma
2011-08-01

Introduction: Despite tremendous efforts in the search for new therapies, a truly efficient cure for hepatocellular carcinoma (HCC) is not available. Oncolytic viruses are promising agents under investigation as new cancer therapeutics. These replication competent viruses selectively infect and kill cancer cells. To enhance cell killing, oncolytic viruses can be engineered to express suicide genes which convert non-toxic substances (prodrugs) into toxic metabolites.
The Clinical Registry of Uterine Sarcomas of the University Women's Clinic and the Comprehensive Cancer Center Tübingen
2011-08-01

Uterine sarcomas comprise a heterogeneous group of diseases with different pathology appearance, clinical course and natural history. They account for only 3% of all uterine malignancies. Due to the rareness of the disease and lack of prospective randomized trials, guidelines of therapeutic management are nonexistent. Therefore our working group aimed to establish a clinical registry of all women that undergo treatment for uterine sarcomas at our institution.
Different effects of the herbal combination STW 5 in small and large intestine of rats
2011-08-01

Herbal medicinal products belong to the most successful treatment options in irritable bowel syndrome (IBS), a functional disorder of the gastrointestinal tract which is still not completely understood in its pathogenesis. The aetiology includes disturbed mechanical transport, caused by hyper- or hypomotility of intestinal smooth muscles. For the herbal combination STW 5 (Iberogast®), the influence on spontaneous and induced contractions of ring preparations from murine jejunum, ileum and colon was determined in an organ bath device.
Biosensors Paving the Way to Understanding the Interaction between Cadmium and the Estrogen Receptor Alpha
2011-08-02

Cadmium is a toxic heavy metal ubiquitously present in the environment and subsequently in the human diet. Cadmium has been proposed to disrupt the endocrine system, targeting in particular the estrogen signaling pathway already at environmentally relevant concentrations. Thus far, the reports on the binding affinity of cadmium towards human estrogen receptor alpha (hERα) have been contradicting, as have been the reports on the in vivo estrogenicity of cadmium. Hence, the mode of interaction between cadmium and the receptor remains unclear. Here, we investigated the interaction between cadmium and hERα on a molecular level by applying a novel, label-free biosensor technique based on reflectometric interference spectroscopy (RIfS). We studied the binding of cadmium to hERα, and the conformation of the receptor following cadmium treatment. Our data reveals that cadmium interacts with the ligand binding domain (LBD) of the ERα and affects the conformation of the receptor. However, the binding event, as well as the induced conformation change, greatly depends on the accessibility of the cysteine tails in the LBD. As the LBD cysteine residues have been reported as targets of post-translational modifications in vivo, we present a hypothesis according to which different cellular pools of ERα respond to cadmium differently. Our proposed theory could help to explain some of the previously contradicting results regarding estrogen-like activity of cadmium.
PK11195, A Specific Ligand of the Peripheral Benzodiazepine Receptor, May Protect Pancreatic Beta-cells from Cytokine-induced Cell Death
2011-08-02

We cultured isolated islets from human or porcine origin in the presence or absence of IL1 and TNFα and studied cytoprotective effects of two structurally different PBR ligands. Storage of pig or human islets in the presence of cytokines significantly lowered the fraction of vital beta-cells. Compared with cytokine incubations PK11195 alone or in combination with cytokines was effective to prevent cytokine induced cell death. The data indicate that cold storage in the presence of PK11195 may further protect beta-cells from cytokine induced cell death. This ligand may be helpful to preserve beta-cell survival before transplantation.
Increased Alpha (8–12 Hz) Activity during Slow Wave Sleep as a Marker for the Transition from Implicit Knowledge to Explicit Insight
2011-08-03

Abstract The number reduction task (NRT) allows us to study the transition from implicit knowledge of hidden task regularities to explicit insight into these regularities. To identify sleep-associated neurophysiological indicators of this restructuring of knowledge representations, we measured frequency-specific power of EEG while participants slept during the night between two sessions of the NRT. Alpha (8–12 Hz) EEG power during slow wave sleep (SWS) emerged as a specific marker of the transformation of presleep implicit knowledge to postsleep explicit knowledge (ExK). Beta power during SWS was increased whenever ExK was attained after sleep, irrespective of presleep knowledge. No such EEG predictors of insight were found during Sleep Stage 2 and rapid eye movement sleep. These results support the view that it is neuronal memory reprocessing during sleep, in particular during SWS, that lays the foundations for restructuring those task-related representations in the brain that are necessary for promoting the gain of ExK.
Prediction model for the incidence and prevalence of type 1 diabetes in childhood and adolescence: evidence for a cohort-dependent increase within the next two decades in Germany
2011-08-03

In comparison to observations made in the past, the risk of disease rises even faster than expected: The younger the child, the quicker the increase of the cohort-age-specific IR and the higher the risk for T1D during lifetime.