julilili42/papers huggingface dataset:
Methods Towards Invasive Human Brain Computer Interfaces
2004-12-01

During the last ten years there has been growing interest in the development of Brain Computer Interfaces (BCIs). The field has mainly been driven by the needs of completely paralyzed patients to communicate. With a few exceptions, most human BCIs are based on extracranial electroencephalography (EEG). However, reported bit rates are still low. One reason for this is the low signal-to-noise ratio of the EEG [14]. We are currently investigating if BCIs based on electrocorticography (ECoG) are a viable alternative. In this paper we present the method and examples of intracranial EEG recordings of three epilepsy patients with electrode grids placed on the motor cortex. The patients were asked to repeatedly imagine movements of two kinds, e.g., tongue or finger movements. We analyze the classifiability of the data using Support Vector Machines (SVMs) [16, 19] and Recursive Channel Elimination (RCE) [10].
The Impact of the Micro-Lightguide O2C for the Quantification of Tissue Ischemia in Diabetic Foot Ulcers
2004-12-01

OBJECTIVE—Tissue oxygen supply is crucial for wound healing. Especially in diabetic foot lesions, the chances for healing are mainly dependent on the presence or absence of ischemia. This study investigates the impact of the tissue O2 analysis system “O2C” for noninvasive quantification of tissue oxygenation in diabetic foot ulcer patients. RESEARCH DESIGN AND METHODS—O2C assessed relative blood flow (flow), flow velocity (velo), and hemoglobin concentration (rHb) and hemoglobin oxygenation (SO2) at 2 and 6 mm depth (means ± SE). 1) Measurements were performed on intact skin of the forefoot and forearm of 20 healthy volunteers on 2 consecutive days. 2) Parameters were assessed on intact skin of the forefoot of diabetic foot ulcer patients (n = 14). 3) Measurements were performed directly at the wound site in diabetic patients (n = 14). RESULTS—1) Flow, velo, rHb, and SO2 at 2 and 6 mm depth were not significantly different when measured at 2 consecutive days. 2) There were no significant differences between diabetic subjects and healthy volunteers. Only flow in 6 mm depth was significantly higher in diabetic subjects (75 ± 13 vs. 51 ± 0.4 arbitrary units [AU], P &amp;lt; 0.05). When diabetic foot ulcer patients were split into healers and nonhealers, initial readings of SO2 at 2 mm (32 ± 6 vs. 44 ± 3%, P &amp;lt; 0.05) and flow in 6 mm (28 ± 1 vs. 51 ± 0.6 AU, P &amp;lt; 0.05) were significantly reduced in nonhealers compared with control subjects, whereas in healers flow in 6 mm (70 ± 0.6 vs. 51 ± 0.6 AU, P &amp;lt; 0.05) was significantly higher than that in control subjects. 3) Initial SO2, rHb, flow, and velo were significantly lower in nonhealing compared with healing wounds. CONCLUSIONS—O2C is a new reliable and valid method for noninvasive measurement of tissue oxygenation and microvascular blood flow in patients with diabetic foot ulcers.
The Impact of ATP-Sensitive K+ Channel Subtype Selectivity of Insulin Secretagogues for the Coronary Vasculature and the Myocardium
2004-12-01

Insulin secretagogues (sulfonylureas and glinides) increase insulin secretion by closing the ATP-sensitive K+ channel (KATP channel) in the pancreatic β-cell membrane. KATP channels subserve important functions also in the heart. First, KATP channels in coronary myocytes contribute to the control of coronary blood flow at rest and in hypoxia. Second, KATP channels in the sarcolemma of cardiomyocytes (sarcKATP channels) are required for adaptation of the heart to stress. In addition, the opening of sarcKATP channels and of KATP channels in the inner membrane of mitochondria (mitoKATP channels) plays a central role in ischemic preconditioning. Opening of sarcKATP channels also underlies the ST-segment elevation of the electrocardiogram, the primary diagnostic tool for initiation of lysis therapy in acute myocardial infarction. Therefore, inhibition of cardiovascular KATP channels by insulin secretagogues is considered to increase cardiovascular risk. Electrophysiological experiments have shown that the secretagogues differ in their selectivity for the pancreatic over the cardiovascular KATP channels, being either highly selective (∼1,000×; short sulfonylureas such as nateglinide and mitiglinide), moderately selective (10–20×; long sulfonylureas such as glibenclamide [glyburide]), or essentially nonselective (&amp;lt;2×; repaglinide). New binding studies presented here give broadly similar results. In clinical studies, these differences are not yet taken into account. The hypothesis that the in vitro selectivity of the insulin secretagogues is of importance for the cardiovascular outcome of diabetic patients with coronary artery disease needs to be tested.
Biosynthetic Gene Cluster of the Herbicide Phosphinothricin Tripeptide from Streptomyces viridochromogenes Tu494
2004-12-01

ABSTRACT The antibiotic phosphinothricin tripeptide (PTT) consists of two molecules of l -alanine and one molecule of the unusual amino acid phosphinothricin (PT) which are nonribosomally combined. The bioactive compound PT has bactericidal, fungicidal, and herbicidal properties and possesses a C—P—C bond, which is very rare in natural compounds. Previously uncharacterized flanking and middle regions of the PTT biosynthetic gene cluster from Streptomyces viridochromogenes Tü494 were isolated and sequenced. The boundaries of the gene cluster were identified by gene inactivation studies. Sequence analysis and homology searches led to the completion of the gene cluster, which consists of 24 genes. Four of these were identified as undescribed genes coding for proteins that are probably involved in uncharacterized early steps of antibiotic biosynthesis or in providing precursors of PTT biosynthesis (phosphoenolpyruvate, acetyl-coenzyme A, or l -alanine). The involvement of the genes orfM and trs and of the regulatory gene prpA in PTT biosynthesis was analyzed by gene inactivation and overexpression, respectively. Insight into the regulation of PTT was gained by determining the transcriptional start sites of the pmi and prpA genes. A previously undescribed regulatory gene involved in morphological differentiation in streptomycetes was identified outside of the left boundary of the PTT biosynthetic gene cluster.
Assessing the Reliability of a Digital Preparation Assistant System Used in Dental Education
2004-12-01

Use of a digital preparation assistant system may improve considerably the quality of preclinical dental education, provided the system works reliably. Thus, the purpose of this pilot study was to quantitatively assess the reliability of a new preclinical digital preparation assistant system (PREPassist, KaVo, Germany). The system was used to repeatedly scan four different unprepared and four different prepared teeth both with and without repositioning. Corresponding measurements were made to quantify accuracy, repeatability, and reproducibility. This was done by estimating the measurement error. Based on this estimation, respective limits of agreement were calculated. We used these ranges, along with assessments of the measurement's accuracy, to judge whether the results satisfy our expectations for clinically acceptable measurements. For preclinical laboratory instruction, the results indicate an acceptable accuracy (mean accuracy of 89 μm) of the measurements. This assessment applies as well to repeatability, given by the range of the respective limits of agreement (range &lt;200 μm). However, in the case of reproducibility, the limits revealed discrepancies of practical importance (range &gt;200 μm). Reproducibility of tooth repositioning in the available mounting device is unacceptable for preclinical laboratory instruction because of the observed range &gt;200 μm. Thus, there is a need for the manufacture of new and more reliable mounting devices because reproducibility procedures are mostly encountered in preclinical instruction in restorative techniques. In contrast to reproducibility, accuracy and repeatability are acceptable for practical purposes. Balancing advantages and disadvantages, we conclude that, in general, the PREPassist system delivers reliable results.
Regulation of the expression of 5‐lipoxygenase–activating protein/5‐lipoxygenase and the synthesis of leukotriene B4 in osteoarthritic chondrocytes: Role of transforming growth factor β and eicosanoids
2004-12-01

Abstract Objective To explore the modulation of 5‐lipoxygenase–activating protein (FLAP) and 5‐lipoxygenase (5‐LOX) expression in human osteoarthritic (OA) chondrocytes, their relative implications in leukotriene B 4 (LTB 4 ) production, the effect of different factors on this system, and the influence of increased LTB 4 production on the synthesis of catabolic factors of cartilage. Methods FLAP and 5‐LOX expression and LTB 4 production were monitored following treatment with transforming growth factor β1 (TGFβ1; 5 ng/ml) and 1,25‐dihydroxyvitamin D 3 (1,25[OH] 2 D 3 ; 50 n M ) alone or in combination with selective or nonselective cyclooxygenase (COX) inhibitors, naproxen (90 μg/ml), NS‐398 (10 μ M ), or FR122047 (5 μ M ), or a dual inhibitor of COX/5‐LOX activity, licofelone (2.6 μ M ). LTB 4 , prostaglandin E 2 (PGE 2 ), and matrix metalloprotease 1 (MMP‐1) production were measured by specific enzyme‐linked immunosorbent assays, nitric oxide by the Griess reaction, and FLAP and 5‐LOX expression by quantitative polymerase chain reaction. Results Human OA chondrocytes expressed both FLAP and 5‐LOX. TGFβ1 and/or 1,25(OH) 2 D 3 induced a rapid and marked enhancement (∼4–13‐fold) in FLAP messenger RNA (mRNA) levels, which was associated with a subsequent and late increase in LTB 4 production and PGE 2 synthesis. Treatment with COX inhibitors in the absence or presence of TGFβ1 and 1,25(OH) 2 D 3 induced a rapid increase in LTB 4 production; this response was mediated by the sustained and significant ( P &lt; 0.01) up‐regulation (∼1.5‐fold) of 5‐LOX mRNA levels. Conversely, treatment with licofelone showed no effect on 5‐LOX but significantly reduced FLAP expression levels. Coincubation of licofelone with TGFβ1 plus 1,25(OH) 2 D 3 did not affect FLAP or 5‐LOX levels. In the presence of TGFβ1 plus 1,25(OH) 2 D 3 , naproxen, but not licofelone, induced MMP‐1 production and both drugs decreased nitric oxide levels. Conclusion Both the eicosanoids PGE 2 and LTB 4 are important cofactors in regulating FLAP/5‐LOX expression; the inhibition of PGE 2 up‐regulates 5‐LOX while down‐regulating FLAP gene expression, and LTB 4 appears to be an up‐regulating factor on the 5‐LOX gene. Importantly, nonsteroidal antiinflammatory drugs up‐regulate the synthesis of LTB 4 , supporting the shunt hypothesis from COX to 5‐LOX. We also demonstrated that LTB 4 likely contributes to the up‐regulation of important catabolic factors involved in the pathophysiology of OA, such as MMP.
ON THE REPRESENTATION, LEARNING AND TRANSFER OF SPATIO-TEMPORAL MOVEMENT CHARACTERISTICS
2004-12-01

In this paper we present a learning-based approach for the modeling of complex movement sequences. Based on the method of Spatio-Temporal Morphable Models (STMMs) we derive a hierarchical algorithm that, in a first step, identifies automatically movement elements in movement sequences based on a coarse spatio-temporal description, and in a second step models these movement primitives by approximation through linear combinations of learned example movement trajectories. We describe the different steps of the algorithm and show how it can be applied for modeling and synthesis of complex sequences of human movements that contain movement elements with a variable style. The proposed method is demonstrated on different applications of movement representation relevant for imitation learning of movement styles in humanoid robotics.
BCL‐2‐induced glioma cell invasiveness depends on furin‐like proteases
2004-12-01

Abstract Migration and invasion are prerequisites for the neoplastic phenotype of malignant glioma. Ectopic expression of BCL‐2 enhances migration and invasion of glioma cells and promotes their synthesis of transforming growth factor‐β 2 (TGF‐β 2 ). We here report that BCL‐2‐expressing cells show enhanced expression and activity of the proprotein convertase, furin, which processes metalloproteinases (MMP) and TGF‐β. Consistent with a biological role for a BCL‐2‐dependent increase in furin‐like protease (FLP) activity, BCL‐2‐expressing cells exhibit enhanced MMP activity. Both a pseudosubstrate furin inhibitor, decanoyl‐Arg‐Val‐Lys‐Arg‐chloromethylketone (dec‐RVKR‐cmk), or alpha 1‐anti‐trypsin Portland (PDX), a recombinant furin‐inhibitory protein, suppress constitutive and BCL‐2‐mediated MMP activity and invasion. This inhibition is not overcome by TGF‐β or hepatocyte growth factor (HGF). A neutralizing TGF‐β antibody attenuates, but not abrogates, the invasive properties conferred by exogenous expression of BCL‐2, whereas the MMP inhibitor o‐phenantroline (o‐PA) abolishes the pro‐invasive action of BCL‐2. Exogenous HGF results in enhanced, and expression of dominant‐negative ezrin in reduced, FLP activity, and dec‐RVKR‐cmk blunts the HGF‐induced expression of mature TGF‐β 2 . Consequently, HGF and BCL‐2 family proteins use a furin‐dependent pathway to promote invasion via TGF‐β and MMP in human malignant glioma cells and the pro‐invasive properties of TGF‐β require furin‐ dependent MMP activity.
Gene shuffling‐generated and natural variants of the tomato resistance gene Cf‐9 exhibit different auto‐necrosis‐inducing activities in Nicotiana species
2004-12-01

Summary Tomato Cf genes encode membrane‐bound proteins with extracellular leucine‐rich repeats, and confer resistance to the fungal tomato pathogen Cladosporium fulvum , and a hypersensitive response (HR) to C. fulvum ‐derived race‐specific elicitors. Several Cf genes, including Cf ‐ 4 and Cf ‐ 9 , are members of the highly homologous Hcr9 ( h omologues of C . fulvum r esistance gene Cf ‐ 9 ) gene family. Hcr9 s evolve mainly by sequence exchange between paralogues, by which novel Cf genes may be generated. To mimic this aspect of natural evolution, we generated chimeras between multiple Hcr9 s in vitro by gene shuffling. The shufflants were tested for novel specificities by transient expression in Nicotiana benthamiana . Many shufflants induced an HR in the absence of fungal elicitors and were designated auto‐activators. We also identified two natural Hcr9 auto‐activators in the wild tomato species Lycopersicon peruvianum , which induced an HR upon expression in N. benthamiana . The Hcr9 auto‐activators exhibit different auto‐necrosis‐inducing specificities in five selected species of the Nicotiana genus, and they were shown to function in the same signalling pathway as Cf ‐ 9 . Auto‐activating alleles of nucleotide binding site–leucine‐rich repeat genes and the protein kinase Pto were previously described. The auto‐activators described here, belonging to the Cf ‐like structural class of resistance genes, shed light on this important phenotype and may be used as tools to unravel the mechanisms by which this class of resistance proteins function.
Is there a role of visual cortex in spatial hearing?
2004-12-01

Abstract The integration of auditory and visual spatial information is an important prerequisite for accurate orientation in the environment. However, while visual spatial information is based on retinal coordinates, the auditory system receives information on sound location in relation to the head. Thus, any deviation of the eyes from a central position results in a divergence between the retinal visual and the head‐centred auditory coordinates. It has been suggested that this divergence is compensated for by a neural coordinate transformation, using a signal of eye‐in‐head position. Using functional magnetic resonance imaging, we investigated which cortical areas of the human brain participate in such auditory–visual coordinate transformations. Sounds were produced with different interaural level differences, leading to left, right or central intracranial percepts, while subjects directed their gaze to visual targets presented to the left, to the right or straight ahead. When gaze was to the left or right, we found the primary visual cortex (V1/V2) activated in both hemispheres. The occipital activation did not occur with sound lateralization per se , but was found exclusively in combination with eccentric eye positions. This result suggests a relation of neural processing in the visual cortex and the transformation of auditory spatial coordinates responsible for maintaining the perceptual alignment of audition and vision with changes in gaze direction.
Dependence of penetration depth, microwave surface resistance and energy gap of MgB2 thin films on their normal-state resistivity
2004-12-01

The dependences of magnetic field penetration depth at zero temperature λ(0), microwave surface resistance Rs and π-band energy gap at zero temperature Δπ(0) on the normal-state resistivity right above the critical temperature, ρ0, were studied for MgB2 thin films prepared by different techniques by employing a sapphire resonator technique. We found that the zero-temperature penetration depth λ(0) data could be well fitted by yielding a London penetration depth λL of 34.5 nm, where ξ0 is the coherence length, and is the mean free path determined from ρ0. The surface resistance Rs at 15 and 20 K increases roughly linearly with ρ0. The observed increase of Δπ(0) with ρ0 and the decrease of Tc indicate the expected effects of interband impurity scattering within an extended BCS approach. The low values of Rs and λ(0) in conjunction with the large coherence length for epitaxial films are potentially attractive for applications in electronics and microwave technology.
Homophilic interactions of chick neurofascin in trans are important for neurite induction
2004-12-01

Abstract Neurofascin is a member of the immunoglobulin superfamily involved in axon extension and fasciculation. Here we apply adenoviral short hairpin RNA (shRNA) expression in primary neurons, PC12–NIH/3T3 co‐cultures in combination with Luminex® assays, to demonstrate homophilic interactions of neurofascin for neurite outgrowth. An adenoviral vector was constructed for the expression of shRNA in primary tectal cells that inhibits gene expression similar to short interfering RNA. We demonstrate that after shRNA‐mediated knockdown neuronal neurofascin expression is important for neurite outgrowth on a neurofascin substrate. Neurite outgrowth assays reveal that neurite formation of PC12 cells is increased when neurofascin is overexpressed on both outgrowing PC12 cells and substrate NIH/3T3 cells, suggesting that neurofascin expression is also sufficient for neurite induction. Luminex technology for the analysis of protein–protein interactions showed homophilic binding of neurofascin to itself.
Risk and Protective Factors Related to Offending: Results from a Chinese Cohort Study
2004-12-01

Recent research has illustrated the importance of risk and protective factors on offending. The current study examines survey data from a sample of 81 offenders and 81 nonoffenders residing in Wuhan, China, in 1991/92 to determine how the accumulation of risk and protective factors in various domains differentiates offenders from nonoffenders. Specifically, we examine the importance of multiple causation and cumulative effects of risk and protective factors as they apply in a Chinese context. Results suggest that the risk and protective factor approach often used in studies of western offending also holds promise in studies of Chinese offending. Specifically, our findings support the importance of examining multiple causation and cumulative effects of risk and protective factors as related to offending. The findings also suggest that the risk and protective factors found to be important in China may be somewhat different to those identified through studies conducted in the West, illustrating the importance of recognising historical and cultural context in the risk and protective factor paradigm.
Metabolic Properties of Vasodilating β Blockers: Management Considerations for Hypertensive Diabetic Patients and Patients With the Metabolic Syndrome
2004-12-01

Type 2 diabetes and hypertension are both insulin‐resistant states that impose an excessive risk burden for future major cardiovascular events, including coronary heart disease, stroke, and heart failure. β‐adrenergic receptor antagonists are effective for the treatment of hypertension, but they are underused in diabetic patients because of possible adverse effects on carbohydrate and lipid metabolism, including insulin resistance, glucose intolerance, and dyslipidemia. Traditional β blockers, both nonselective and selective, are vasoconstrictive due to unopposed α 1 activity; however, vasodilating β blockers are not associated with these negative metabolic effects. This review discusses the background of insulin resistance and its link to diabetes and hypertension, emphasizing the role of vascular control by the renin‐angiotensin and sympathetic nervous systems on insulin sensitivity and glucose utilization. Clinical evidence is reviewed for the use of vasodilating β blockers in the treatment of hypertension and in reducing cardiovascular risk in the diabetic population.
Posttranscriptional regulation of the immediate‐early gene EGR1 by light in the mouse retina
2004-12-01

Abstract Synaptic plasticity is modulated by differential regulation of transcription factors such as EGR1 which binds to DNA via a zinc finger binding domain. Inactivation of EGR1 has implicated this gene as a key regulator of memory formation and learning. However, it remains puzzling how synaptic input can lead to an up‐regulation of the EGR‐1 protein within only a few minutes. Here, we show by immunohistochemical staining that the EGR‐1 protein is localized in synapses throughout the mouse retina. We demonstrate for the first time that two variants of Egr‐1 mRNA are produced in the retina by alternative polyadenylation, with the longer version having an additional 293 base pairs at the end of the 3′UTR. Remarkably, the use of the alternative polyadenylation site is controlled by light. The additional 3′UTR sequence of the longer variant displays an even higher level of phylogenetic conservation than the coding region of this highly conserved gene. Additionally, it harbours a cytoplasmic polyadenylation element which is known to respond to NMDA receptor activation. The longer version of the Egr‐1 mRNA could therefore rapidly respond to excitatory stimuli such as light or glutamate release whereas the short variant, which is predominantly expressed and contains the full coding sequence, lacks the regulatory elements for cytoplasmic polyadenylation in its 3′UTR.