julilili42/papers huggingface dataset:
Predictive Coding or Evidence Accumulation? False Inference and Neuronal Fluctuations
2010-03-26

Perceptual decisions can be made when sensory input affords an inference about what generated that input. Here, we report findings from two independent perceptual experiments conducted during functional magnetic resonance imaging (fMRI) with a sparse event-related design. The first experiment, in the visual modality, involved forced-choice discrimination of coherence in random dot kinematograms that contained either subliminal or periliminal motion coherence. The second experiment, in the auditory domain, involved free response detection of (non-semantic) near-threshold acoustic stimuli. We analysed fluctuations in ongoing neural activity, as indexed by fMRI, and found that neuronal activity in sensory areas (extrastriate visual and early auditory cortex) biases perceptual decisions towards correct inference and not towards a specific percept. Hits (detection of near-threshold stimuli) were preceded by significantly higher activity than both misses of identical stimuli or false alarms, in which percepts arise in the absence of appropriate sensory input. In accord with predictive coding models and the free-energy principle, this observation suggests that cortical activity in sensory brain areas reflects the precision of prediction errors and not just the sensory evidence or prediction errors per se.
Heart Rate Turbulence to Guide Treatment for Prevention of Sudden Death
2010-03-26

Heart rate turbulence (HRT) denotes the baroreflex-mediated short-term oscillation of cardiac cycle lengths after spontaneous ventricular premature complexes. The physiological pattern of HRT consists of brief heart rate acceleration followed by more gradual heart rate deceleration before the heart rate returns to baseline. Physiological mechanisms of HRT are complex and require an intact interplay between both sympathetic and parasympathetic nervous systems. The strong and independent prognostic value of HRT in identifying postinfarction patients at high risk for death has been validated in six retrospective and three prospective studies together enrolling more than 8000 patients. This evidence qualifies HRT as a promising tool for selection of patients who might benefit from implantation of a cardioverter-defibrillator. Moreover, HRT predicts poor outcome in patients with heart failure. It is not only correlated with a patient's clinical status, but also recovers when heart failure treatment, including beta-blockers, angiotensin-converting enzyme inhibitors, or cardiac resynchronization therapy, is effective. Therefore, HRT might also be used as a treatment target to guide pharmacotherapy of heart failure.
Anchoring the deficit of the anchor deficit: dyslexia or attention?
2010-03-26

Abstract In the anchoring deficit hypothesis of dyslexia ( Trends Cogn. Sci ., 2007; 11 : 458–465), it is proposed that perceptual problems arise from the lack of forming a perceptual anchor for repeatedly presented stimuli. A study designed to explicitly test the specificity of the anchoring deficit for dyslexia is presented. Four groups, representing all combinations of reading skills (high or low) and attention (high or low), were given a time estimation task in which a standard tone was compared with tones of varying length. Poor readers showed problems only if they had limited attentional skills as well, while poor readers with good attention were unaffected. It is concluded that a single deficit in time estimation is not sufficient to cause reading deficits. Copyright © 2010 John Wiley &amp; Sons, Ltd.
A model for temporal features of visual sensations evoked by a subretinal electrode array for restoration of vision
2010-03-26

Purpose: Subretinal microphotodiode-arrays (MPDAs) have the potential to restore vision in patients suffering from degenerative retinal diseases such as Retinitis Pigmentosa. Experiments with patients taking part in clinical studies revealed the feasibility of electrically evoking visual sensations (phosphenes). Here we present results delivered by a model which reproduces implant-evoked activity distributions of retinal ganglion cells (RGC), considering activity spread in the retinal network as well as frequency dependent RGC-adaptation. Methods: Input to the model was a movie-file representing two parallel rotating white bars. Width of the bars was 20x100 pixels with 20 pixels distance on a 100x100 pixels black background. Parameters for timing were set such that the output allowed recognizing form, number, speed and orientation of input stimuli. Retinal activity parameters from previous experiments were regarded in order to quantify spread of network activation in the retina and amplitude of RGC-activity. RGC-activity furthermore underwent frequency dependent adaptation. Results: RGC activity patterns conveyed a satisfactory motion picture quality in this model when electrodes were activated with sufficiently high frequencies between 5Hz and 10Hz, assuming an input frame rate of 10–20 frames per second. High stimulation frequencies allowed continuous evaluation of position and speed of the stimuli, however visual sensations faded quickly within only few seconds after onset of the movie. RGC activity was not subject to adaptation if the stimulation frequency remained below 2Hz. Therefore slowly moving objects still were recognizable at low stimulation frequencies, but movement speed of the rotating bar - stimulus could no longer be realistically estimated. Conclusions: Simulation of realistic approximations to visual sensations as evoked by subretinal MPDAs is subject to a number of assumptions made during model development. However model outputs sufficiently reproduced critical attributes of input stimuli. Also, disappearance of the sensations was in principal agreement with reports from clinical study patients carrying the subretinal MPDA.
ChemInform Abstract: Thienopyridone Antibacterials. Part 5. Synthesis of Some N(7)‐Azacyclohexyl‐4‐oxothieno[2,3‐b]pyridine‐5‐carboxylic Acids and Related Congeners.
2010-03-26

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Prenyl Transfer to Aromatic Substrates in the Biosynthesis of Aminocoumarins, Meroterpenoids and Phenazines: The ABBA Prenyltransferase Family.
2010-03-26

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Phosphinothricin‐Tripeptide Biosynthesis: An Original Version of Bacterial Secondary Metabolism?
2010-03-26

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Diffusion Tensor Imaging in a Human PET/MR Hybrid System
2010-03-27

Diffusion tensor imaging may be combined with simultaneous PET data acquisition, offering additional important morphologic and functional information for treatment planning in patients with brain tumors.
Colour and spatial cue for action: Subliminal colour cue effects motor behaviour
2010-03-28

We addressed two important implications from Millner and Goodel's theory on dissociation of vision for perception and for action. i)Colour processing in the Ventral stream is not integrated in the visual guidance of body movements; ii) The access of colour information to motor systems is obligatory based on visual awareness. To address the first notion we employed a Redundant-target paradigm in which subjects reacted to spatial, colour or combination of both (redundant) targets. Further, our subjects reacted to isoluminant coloured targets preceded by subliminal incongruent ones. A second condition without subliminal priming target was compared against the first one. The observed Reaction time gain is interpreted as resulting from combined sensory information in reaching some decision criterion. We also show that stimuli blocked from awareness (subliminal cues) are able to delay the fast motor responses. Overall, the results are inconsistent with the theory of independent action and perception pathways and provide behavioural evidence for interactions between ventral and dorsal streams.
Titanium surfaces structured with regular geometry—material investigations and cell morphology
2010-03-29

Abstract Mathematical modeling of the cell–material contact demands a thorough characterization of both the material surface and the cellular reaction. In earlier investigations we used stochastic material surfaces for this purpose. Also, other groups working on the same or similar subject used such stochastically structured material surfaces. In continuation of this work we now use fine‐structured material surfaces with well‐defined regular geometry because a stepwise and systematic variation of the structural parameters of geometrically defined surfaces makes it easier to find the characteristic parameters for modeling the cell–material interface. To begin with, we used grooves with rectangular profiles and cubic pillars. The grooves were etched in silicon by dry etching and then were sputter coated with 100 nm titanium. Arrays of cubic photo resist pillars with vertical side walls in different dimensions were obtained by a photolithographic process and were also sputter coated with 100 nm titanium. The samples were characterized by SEM and electrochemical methods. Human osteoblastic cells MG‐63 (ATCC, LGC promochem, Manassas, USA) were cultured in Dulbecco's modified eagle medium with 10% fetal calf serum (FCS) at 37 °C and 5% CO 2 . MG‐63 cells grown on microstructures within 24 h were visualized by SEM. We observed that cells on the grooved surfaces grew along the grooves mainly adhering to the horizontal edges of the material surface, whereas on the pillar structures the cells lie on the top of the pillars and are well spread. But the direction of spreading on the pillars is also determined by the horizontal and vertical edges of the surface structure. Copyright © 2010 John Wiley &amp; Sons, Ltd.
Association of Lower Plasma Fetuin-A Levels With Peripheral Arterial Disease in Type 2 Diabetes
2010-03-29

In the article by Eraso et al. (1), circulating fetuin-A was lower in subjects with type 2 diabetes and an ankle brachial index (ABI) <0.9 compared with individuals with higher ABI. Furthermore, in an unadjusted model circulating fetuin-A correlated positively with ABI. It was concluded that low circulating fetuin-A may serve as a biomarker of peripheral arterial disease (PAD). This conclusion is only weakly supported by the data. It is very important to know that in the study by Eraso et al. (1), subjects with any clinical evidence of cardiovascular disease (CVD) were excluded. Considering that ...
Alterations in Ceramide Concentration and pH Determine the Release of Reactive Oxygen Species by Cftr-Deficient Macrophages on Infection
2010-03-30

Abstract We recently demonstrated that the accumulation of ceramide in Cftr-deficient epithelial cells is important for the pathophysiology of CF. However, the role of ceramide in other lung cells, particularly lung macrophages, requires definition. In this study, we report that ceramide is accumulated in Cftr-deficient lung macrophages. Alveolar macrophages contain a vesicle population, which is stained with LysoSensor probes but not by tetramethylrhodamine dextran. These vesicles, presumably secretory lysosomes, exhibit a higher pH in Cftr-deficient macrophages than the corresponding vesicles in lung macrophages isolated from wild-type (WT) mice. Alkalinization of these vesicles in Cftr-deficient macrophages correlates with a failure of the macrophages to respond to infection with various Pseudomonas aeruginosa strains by acutely activating acid sphingomyelinase, releasing ceramide, forming ceramide-enriched membrane platforms that serve to cluster gp91phox, and, most importantly, releasing reactive oxygen species (ROS). In contrast, these events occur rapidly in WT lung macrophages postinfection. Inhibiting ROS in WT macrophages prevents the killing of P. aeruginosa. These findings provide evidence for a novel pH-controlled pathway from acid sphingomyelinase activation via ceramide and clustering of gp91phox to the release of ROS in lung macrophages.
Adrenaline-induced colonic K+secretion is mediated by KCa1.1 (BK) channels
2010-03-30

Colonic epithelial K(+) secretion is a two-step transport process with initial K(+) uptake over the basolateral membrane followed by K(+) channel-dependent exit into the lumen. In this process the large-conductance, Ca(2+)-activated K(Ca)1.1 (BK) channel has been identified as the only apparent secretory K(+) channel in the apical membrane of the murine distal colon. The BK channel is responsible for both resting and Ca(2+)-activated colonic K(+) secretion and is up-regulated by aldosterone. Agonists (e.g. adrenaline) that elevate cAMP are potent activators of distal colonic K(+) secretion. However, the secretory K(+) channel responsible for cAMP-induced K(+) secretion remains to be defined. In this study we used the Ussing chamber to identify adrenaline-induced electrogenic K(+) secretion. We found that the adrenaline-induced electrogenic ion secretion is a compound effect dominated by anion secretion and a smaller electrically opposing K(+) secretion. Using tissue from (i) BK wildtype (BK(+/+)) and knockout (BK(/)) and (ii) cystic fibrosis transmembrane regulator (CFTR) wildtype (CFTR(+/+)) and knockout (CFTR(/)) mice we were able to isolate the adrenaline-induced K(+) secretion. We found that adrenaline-induced K(+) secretion: (1) is absent in colonic epithelia from BK(/) mice, (2) is greatly up-regulated in mice on a high K(+) diet and (3) is present as sustained positive current in colonic epithelia from CFTR(/) mice. We identified two known C-terminal BK alpha-subunit splice variants in colonic enterocytes (STREX and ZERO). Importantly, the ZERO variant known to be activated by cAMP is differentially up-regulated in enterocytes from animals on a high K(+) diet. In summary, these results strongly suggest that the adrenaline-induced distal colonic K(+) secretion is mediated by the BK channel and probably involves aldosterone-induced ZERO splice variant up-regulation.
A New Group of Aromatic Prenyltransferases in Fungi, Catalyzing a 2,7-Dihydroxynaphthalene 3-Dimethylallyl-transferase Reaction
2010-03-30

Five fungal genomes from the Ascomycota (sac fungi) were found to contain a gene with sequence similarity to a recently discovered small group of bacterial prenyltransferases that catalyze the C-prenylation of aromatic substrates in secondary metabolism. The genes from Aspergillus terreus NIH2624, Botryotinia fuckeliana B05.10 and Sclerotinia sclerotiorum 1980 were expressed in Escherichia coli, and the resulting His(8)-tagged proteins were purified and investigated biochemically. Their substrate specificity was found to be different from that of any other prenyltransferase investigated previously. Using 2,7-dihydroxynaphthalene (2,7-DHN) and dimethylallyl diphosphate as substrates, they catalyzed a regiospecific Friedel-Crafts alkylation of 2,7-DHN at position 3. Using the enzyme of A. terreus, the K(m) values for 2,7-DHN and dimethylallyl diphosphate were determined as 324 +/- 25 microM and 325 +/- 35 microM, respectively, and k(cat) as 0.026 +/- 0.001 s(-1). A significantly lower level of prenylation activity was found using dihydrophenazine-1-carboxylic acid as aromatic substrate, and only traces of products were detected with aspulvinone E, flaviolin, or 4-hydroxybenzoic acid. No product was formed with l-tryptophan, l-tyrosine, or 4-hydroxyphenylpyruvate. The genes for these fungal prenyltransferases are not located within recognizable secondary metabolic gene clusters. Their physiological function is yet unknown.
Online Anomaly Detection under Adversarial Impact
2010-03-31

Security analysis of learning algorithms is gaining increasing importance, especially since they have become target of deliberate obstruction in certain applications. Some security-hardened algorithms have been previously proposed for supervised learning; however, very little is known about the behavior of anomaly detection methods in such scenarios. In this contribution, we analyze the performance of a particular method— online centroid anomaly detection—in the presence of adversarial noise. Our analysis addresses three key security-related issues: derivation of an optimal attack, analysis of its efficiency and constraints. Experimental evaluation carried out on real HTTP and exploit traces confirms the tightness of our theoretical bounds. 1
Isotope shift measurements in the 2s1/2→ 2p3/2transition of Be+and extraction of the nuclear charge radii for7, 10, 11Be
2010-03-31

Abstract\\nshift measurements in the 2s 1/2 ? 2p 3/2 transition of Be + and extraction of the nuclear charge radii for 7, 10, 11 Be Abstract. We have performed isotope shift measurements in the 2s 1/2 ? 2p 3/2 transition of Be + ions using advanced collinear laser spectroscopy with two counterpropagating laser beams. Measurements involving a frequency comb for laser stabilization and absolute frequency determination allowed us to determine the isotope shifts with an accuracy of 2 MHz. From the isotope shifts between 9 Be and 7, 10, 11 Be, high-accuracy mass shift calculations and the charge radius of the reference isotope 9 Be we determined nuclear charge radii for the isotopes 7, 10 Be and the one-neutron halo nucleus 11 Be. The results are compared to nuclear-structure calculations using the Fermionic Molecular Dynamics model which reproduce well the general trend of the radii. Decreasing charge radii from 7 Be to 10 Be are explained by the cluster structure of the nuclei. The increase from 10 Be to 11 Be is mainly caused by the halo neutron by which the 10 Be core moves relative to the center of mass. Polarization of the 10 Be core has only a small influence on the charge radius.
Altered Expression of Metallothionein-I and -II and Their Receptor Megalin in Inherited Photoreceptor Degeneration
2010-03-31

Induction of metallothionein-I and -II occurs in the RP models studied and correlates with glial activation. The progressive loss of megalin suggests that transport of metallothionein-I+II into the degenerating photoreceptors (from e.g., Müller cells), could be impaired, potentially limiting the actions of these metallothioneins.
Laparoscopic Roux-en-Y Hepaticojejunostomy in Children with Long Common Pancreaticobiliary Channel: Surgical Technique and Functional Outcome
2010-03-31

The laparoscopic approach for pathology of pancreaticobiliary ducts might be a new alternative for surgical treatment in infants and children. It can also be performed in cases with choledochal cyst involving the hepatic ducts and for reresection of remnants of CBD.
Recovery of mechano-electrical transduction in rat cochlear hair bundles after postnatal destruction of the stereociliar cross-links
2010-03-31

Mechano-electrical transduction (MET) in the stereocilia of outer hair cells (OHCs) was studied in newborn Wistar rats using scanning electron microscopy to investigate the stereociliar cross-links, Nomarski laser differential interferometry to investigate stereociliar stiffness and by testing the functionality of the MET channels by recording the entry of fluorescent dye, FM1-43, into stereocilia. Preparations were taken from rats on their day of birth (P0) or 1–4 days later (P1–P4). Hair bundles developed from the base to the apex and from the inner to outer OHC rows. MET channel responses were detected in apical coil OHCs on P1. To study the possible recovery of MET after disrupting the cross-links, the same investigations were performed after the application of Ca 2+ chelator 1,2-bis(o-aminophenoxy)ethane- N , N , N ′, N ′-tetraacetic acid (BAPTA) and allowing the treated samples to recover in culture medium for 0–20 h. We found that the structure and function were abolished by BAPTA. In P0–P1 samples, structural recovery was complete and the open probability of MET channels reached control values. In P3–P4 samples, complete recovery only occurred in OHCs of the outermost row. Although our results demonstrate an enormous recovery potential of OHCs in the postnatal period, the structural component restricts the potential for therapy in patients.
Endocytic and Secretory Traffic in Arabidopsis Merge in the Trans-Golgi Network/Early Endosome, an Independent and Highly Dynamic Organelle
2010-04-01

Abstract Plants constantly adjust their repertoire of plasma membrane proteins that mediates transduction of environmental and developmental signals as well as transport of ions, nutrients, and hormones. The importance of regulated secretory and endocytic trafficking is becoming increasingly clear; however, our knowledge of the compartments and molecular machinery involved is still fragmentary. We used immunogold electron microscopy and confocal laser scanning microscopy to trace the route of cargo molecules, including the BRASSINOSTEROID INSENSITIVE1 receptor and the REQUIRES HIGH BORON1 boron exporter, throughout the plant endomembrane system. Our results provide evidence that both endocytic and secretory cargo pass through the trans-Golgi network/early endosome (TGN/EE) and demonstrate that cargo in late endosomes/multivesicular bodies is destined for vacuolar degradation. Moreover, using spinning disc microscopy, we show that TGN/EEs move independently and are only transiently associated with an individual Golgi stack.
Impact of Age on the Relationships of Brown Adipose Tissue With Sex and Adiposity in Humans
2010-04-01

OBJECTIVE Brown adipose tissue (BAT) regulates energy homeostasis and fat mass in mammals and newborns and, most likely, in adult humans. Because BAT activity and BAT mass decline with age in humans, the impact of BAT on adiposity may decrease with aging. In the present study we addressed this hypothesis and further investigated the effect of age on the sex differences in BAT activity and BAT mass. RESEARCH DESIGN AND METHODS Data from 260 subjects (98 with BAT and 162 study date–matched control subjects) who underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) under thermoneutral conditions were analyzed. BAT activity and BAT mass were determined in the upper body. RESULTS BAT activity and BAT mass were higher in female (1.59 ± 0.10 and 32 ± 5 g vs. 1.02 ± 0.10 and 18 ± 4 g, both P ≤ 0.0006) than in male subjects. In multivariate analyses, sex (P &amp;lt; 0.0001), age (P &amp;lt; 0.0001), and BMI (P = 0.0018) were associated independently with BAT activity. Interestingly, only in male subjects was there an interaction between BMI and age in determining BAT activity (P = 0.008) and BAT mass (P = 0.0002); BMI decreased with increasing BAT activity and BAT mass in the lowest age tertile (Spearman rank correlation coefficient rs = −0.38, P = 0.015 and rs = −0.37, P = 0.017, respectively), not in the higher age tertiles. Furthermore, BAT activity and mass differed between female and male subjects only in the upper two age tertiles (all P ≤ 0.09). CONCLUSIONS Our data corroborate that, in general, BAT activity and BAT mass are elevated in female subjects and in younger people. Importantly, we provide novel evidence that the impact of BAT activity and BAT mass on adiposity appears to decline with aging only in male subjects. Furthermore, while BAT activity and BAT mass only moderately decline with increasing age in female subjects, a much stronger effect is found in male subjects.