julilili42/papers huggingface dataset:
The Impact of Catechol-O-Methyltransferase and Dopamine D4 Receptor Genotypes on Neurophysiological Markers of Performance Monitoring
2007-12-19

Dynamic adaptations of one's behavior by means of performance monitoring are a central function of the human executive system, that underlies considerable interindividual variation. Converging evidence from electrophysiological and neuroimaging studies in both animals and humans hints at the importance of the dopaminergic system for the regulation of performance monitoring. Here, we studied the impact of two polymorphisms affecting dopaminergic functioning in the prefrontal cortex [catechol- O -methyltransferase (COMT) Val108/158Met and dopamine D4 receptor (DRD4) single-nucleotide polymorphism (SNP)-521] on neurophysiological correlates of performance monitoring. We applied a modified version of a standard flanker task with an embedded stop-signal task to tap into the different functions involved, particularly error monitoring, conflict detection and inhibitory processes. Participants homozygous for the DRD4 T allele produced an increased error-related negativity after both choice errors and failed inhibitions compared with C -homozygotes. This was associated with pronounced compensatory behavior reflected in higher post-error slowing. No group differences were seen in the incompatibility N2, suggesting distinct effects of the DRD4 polymorphism on error monitoring processes. Additionally, participants homozygous for the COMT Val allele, with a thereby diminished prefrontal dopaminergic level, revealed increased prefrontal processing related to inhibitory functions, reflected in the enhanced stop-signal-related components N2 and P3a. The results extend previous findings from mainly behavioral and neuroimaging data on the relationship between dopaminergic genes and executive functions and present possible underlying mechanisms for the previously suggested association between these dopaminergic polymorphisms and psychiatric disorders as schizophrenia or attention deficit hyperactivity disorder.
MRI Findings in Deep and Generalized Morphea (Localized Scleroderma)
2007-12-19

Imaging features of morphea are not specific and usually overlap with those of other disorders involving the skin, fascia, and musculature, such as some types of fasciitis, myositis, and so forth. Nevertheless, the imaging features of morphea reflect pathomorphologic changes of this rare disorder and enable a complete assessment of the disease extent, including depth of infiltration and disease activity.
Perturbation theory of Coulomb gauge Yang-Mills theory within the first order formalism
2007-12-19

Perturbative Coulomb gauge Yang-Mills theory within the first order formalism is considered. Using a differential equation technique and dimensional regularization, analytic results for both the ultraviolet divergent and finite parts of the two-point functions at one-loop order are derived. It is shown how the non-ultraviolet divergent parts of the results are finite at spacelike momenta with kinematical singularities on the light-cone and subsequent branch cuts extending into the timelike region.
Systematic Variation of Off-Resonance Prepulses for Clinical Magnetization Transfer Contrast Imaging at 0.2, 1.5, and 3.0 Tesla
2007-12-19

The increased MT effect at a higher field strength can partly compensate the specific absorption rate related problems in MTC applications. It is shown that for flip angles of 700 degrees to 900 degrees and offset frequencies of 1000 Hz to 1500 Hz, high quality MTR maps could be obtained at an acceptable level of direct saturation for all field strengths. Furthermore, if the better signal-to-noise ratio at higher magnetic fields is taken into account, quality of MTR maps of the head and the knee at 3.0 T was clearly improved compared with lower fields under optimized and comparable conditions.
Processing of inconsistent emotional information: an fMRI study
2007-12-19

Previous studies investigating the anterior cingulate cortex (ACC) have relied on a number of tasks which involved cognitive control and attentional demands. In this fMRI study, we tested the model that ACC functions as an attentional network in the processing of language. We employed a paradigm that requires the processing of concurrent linguistic information predicting that the cognitive costs imposed by competing trials would engender the activation of ACC. Subjects were confronted with sentences where the semantic content conflicted with the prosodic intonation (CONF condition) randomly interspaced with sentences which conveyed coherent discourse components (NOCONF condition). We observed the activation of the rostral ACC and the middle frontal gyrus when the NOCONF condition was subtracted from the CONF condition. Our findings provide evidence for the involvement of the rostral ACC in the processing of complex competing linguistic stimuli, supporting theories that claim its relevance as a part of the cortical attentional circuit. The processing of emotional prosody involved a bilateral network encompassing the superior and medial temporal cortices. This evidence confirms previous research investigating the neuronal network that supports the processing of emotional information.
Dissociable Roles of the Superior Temporal Sulcus and the Intraparietal Sulcus in Joint Attention: A Functional Magnetic Resonance Imaging Study
2007-12-20

Abstract Previous imaging work has shown that the superior temporal sulcus (STS) region and the intraparietal sulcus (IPS) are specifically activated during the passive observation of shifts in eye gaze [Pelphrey, K. A., Singerman, J. D., Allison, T., & McCarthy, G. Brain activation evoked by perception of gaze shifts: The influence of context. Neuropsychologia, 41, 156-170, 2003; Hoffman, E. A., & Haxby, J. V. Distinct representations of eye gaze and identity in the distributed human neural system for face perception. Nature Neuroscience, 3, 80-84, 2000; Puce, A., Allison, T., Bentin, S., Gore, J. C., & McCarthy, G. Temporal cortex activation in humans viewing eye and mouth movements. Journal of Neuroscience, 18, 2188-2199, 1998; Wicker, B., Michel, F., Henaff, M. A., & Decety, J. Brain regions involved in the perception of gaze: A PET study. Neuroimage, 8, 221-227, 1998]. Are the same brain regions also involved in extracting gaze direction in order to establish joint attention? In an event-related functional magnetic resonance imaging experiment, healthy human subjects actively followed the directional cue provided by the eyes of another person toward an object in space or, in the control condition, used a nondirectional symbolic cue to make an eye movement toward an object in space. Our results show that the posterior part of the STS region and the cuneus are specifically involved in extracting and using detailed directional information from the eyes of another person to redirect one's own gaze and establish joint attention. The IPS, on the other hand, seems to be involved in encoding spatial direction and mediating shifts of spatial attention independent of the type of cue that triggers this process.
Octahedral Coordination Compounds of the Ni, Pd, Pt Triad
2007-12-20

Aiming high: The coordination of the tin ligand stanna-closo-dodecaborate at Ni, Pd, and Pt results in the formation of compounds with high negative charges. These complexes contain metal centers with high coordination numbers and in high formal oxidation states. In the case of the platinum derivative, a far upfield chemical shift in the 195Pt NMR spectrum (δ=−7724 ppm) was observed.
Opposite Signs of Capacitive Microsensor Signals upon Exposure to the Enantiomers of Methyl Propionate Compounds
2007-12-20

Capacitive chemical sensors, coated with modified cyclodextrins, provide antipode signals upon exposure to the enantiomers of methyl propionate compounds, thus allowing an unambiguous determination of the enantiomer identity (see graphic). The dielectric coefficients of the enantiomer–receptor complexes significantly differ, so that this simple sensor technique can be used to detect the subtle effects of different molecular orientations. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z704346_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
ChemInform Abstract: Chalcogenone C:E Compounds
2007-12-20

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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.
Opposite Signs of Capacitive Microsensor Signals upon Exposure to the Enantiomers of Methyl Propionate Compounds
2007-12-20

Kapazitive chemische Sensoren, die mit modifizierten Cyclodextrinen beschichtet sind, erzeugen antipodale Signale für die Enantiomere von Methylpropionaten und ermöglichen so eine eindeutige Bestimmung der Art des Enantiomers (siehe Diagramm). Die Dielektrizitätkoeffizienten der Enantiomer-Rezeptor-Komplexe unterscheiden sich deutlich, sodass diese einfache Sensortechnik dazu genutzt werden kann, die schwach ausgeprägten Effekte unterschiedlicher Molekülorientierungen zu detektieren.
Reduced saccadic resilience and impaired saccadic adaptation due to cerebellar disease
2007-12-21

Abstract The term short‐term saccadic adaptation (STSA) captures our ability to unconsciously move the endpoint of a saccade to the final position of a visual target that has jumped to a new location during the saccade. STSA depends on the integrity of the cerebellar vermis. We tested the hypothesis that STSA reflects the working of a cerebellar mechanism needed to avoid ‘fatigue’, a gradual drop in saccade amplitude during a long series of stereotypic saccades. To this end we compared the kinematics of saccades of 14 patients suffering from different forms of cerebellar disease with those of controls in two tests of STSA and a test of saccadic resilience. Controls showed an increase in saccade amplitude (SA) for outward adaptation, prompted by outward target shifts, due to an increase in saccade duration (SD) in the face of constant peak velocity (PV). The decrease in SA due to inward adaptation was, contrariwise, accompanied by a drop in PV and SD. Whereas patients with intact vermis did not differ from controls, those with vermal pathology lacked outward adaptation: SD remained constant, as did SA and PV. In contrast, vermal patients demonstrated a significant decrease in SA, paralleled by a decrease in PV but mostly unaltered SD in the inward adaptation experiment as well as in the resilience test. These findings support the notion that inward adaptation is at least partially based on uncompensated fatigue. On the other hand, outward adaptation reflects an active mechanism for the compensation of fatigue, residing in the cerebellum.
Towards the improvement of the synthesis of novel 4(5)-aryl-5(4)-heteroaryl-2-thio-substituted imidazoles and their p38 MAP kinase inhibitory activity
2007-12-21

A series of 2-alkylsulfanyl-4-(4-fluorophenyl)-5-(2-aminopyridin-4-yl)-substituted imidazoles was prepared and interaction possibilities of the 2-thioether moiety with phosphate/ribose binding pockets of p38 MAP kinase were investigated. Introduction of the alkyl/benzyl amino function at the pyridine moiety was carried out via nucleophilic substitution or via palladium catalyzed aryl-C-N-bond formation.
Speech-in-noise intelligibility does not correlate with efferent olivocochlear reflex in humans with normal hearing
2007-12-25

For optimum measurement of CS, the study was restricted to subjects (n =49) with valid DPOAE down to primary tone levels L1=47/L2 =20 dB SPL. Average SRT was -6.66 dB (-4.50 to -7.65 dB, SD 0.63 dB). CS increased with decreasing primary tone levels, with mean absolute CS values in the range of 0.6-6 dB SPL. Test-retest repeatability was good. Statistical evaluation revealed no significant relationship between SI and CS of DPOAE.
Hypoxia Inducible Factor (HIF)-1 Coordinates Induction of Toll-Like Receptors TLR2 and TLR6 during Hypoxia
2007-12-26

Taking together, these studies reveal coordinated induction of TLR2 and TLR6 during hypoxia and suggest tissue hypoxia in transcriptional adaptation of innate immune responses during acute infection or inflammation.
Diagnostic value of nodule palpation in onchocerciasis
2007-12-26

Nodule palpation is the major diagnostic tool for determining the prevalence of infection in areas of the African Programme for Onchocerciasis Control (APOC) and is recommended for identifying communities at risk and selecting them for mass drug administration. The diagnostic value of palpation, however, has not been quantified in terms of sensitivity and predictive values. We derive these measures from the probability that a nodule is palpable, which has been estimated by stochastic simulations from an extensive pre-control database. We show that nodule palpation is only reliable in highly endemic areas and that false-positive diagnoses can lead to considerable misclassifications of regions where endemicity is actually low. Its diagnostic precision is poor because of large intra- and inter-individual variability. The findings underline the need for further development of available diagnostics that allow long-term monitoring when endemicity declines.
Genetic variability in the SNCA gene influences α‐synuclein levels in the blood and brain
2007-12-27

Genetic variability in the promoter and 3′ region of the SNCA gene coding α‐synuclein modulates the risk to develop sporadic Parkinson's disease (PD). Whether this is mediated by regulating a‐synuclein expression levels remains unknown. Therefore, we analyzed levels of α‐synuclein in blood and human post mortem brain tissue including the substantia nigra using quantitative real‐time reverse transcriptase‐ polymerase chain reaction and enzyme linked immu‐nosorbent assay in vivo . Single nucleotide polymor‐phism (SNP) rs356219, a tagging SNP for a disease‐ associated haplotype in the 3′ region of the SNCA gene, has a significant effect on SNCA mRNA levels in the substantia nigra and the cerebellum. Further, the “protective” genotype 259/259 of the PD‐associated promoter repeat NACP‐Repl is associated with lower protein levels in blood than genotypes 261/261, 259/261, and 259/263. In conclusion, we provide evidence that a‐synuclein levels are influenced by genetic variability in the promoter and 3′ region of the SNCA gene in vivo .—Fuchs, J., Tichopad, A., Golub, Y., Munz, M., Schweitzer, K. J., Wolf, B., Berg, D., Mueller, J. C., Gasser, T. Genetic variability in the SNCA gene influences α‐synuclein levels in the blood and brain. FASEB J . 22, 1327–1334 (2008)
Tight Link Between Our Sense of Limb Ownership and Self-Awareness of Actions
2007-12-28

Background and Purpose— Hemiparetic stroke patients with disturbed awareness for their motor weakness (anosognosia for hemiparesis/-plegia [AHP]) may exhibit further abnormal attitudes toward or perceptions of the affected limb(s). The present study investigated the clinical relationship and the anatomy of such abnormal attitudes and AHP. Methods— In a new series of 79 consecutively admitted acute stroke patients with right brain damage and hemiparesis/ -plegia, different types of abnormal attitudes toward the hemiparetic/plegic limb (asomatognosia, somatoparaphrenia, anosodiaphoria, misoplegia, personification, kinaesthetic hallucinations, supernumerary phantom limb) were investigated. Results— Ninty-two percent of the patients with AHP showed additional “disturbed sensation of limb ownership” (DSO) for the paretic/plegic limb. The patients had the feeling that their contralesional limb(s) do not belong to their body or even belong to another person. Analysis of lesion location revealed that the right posterior insula is a crucial structure involved in these phenomena. Conclusions— DSO for hemiparetic/-plegic limbs and AHP are tightly linked both clinically and anatomically. The right posterior insula seems to be a crucial structure involved in the genesis of our sense of limb ownership and self-awareness of actions.
Marker Removal in Staphylococci via Cre Recombinase and Different lox Sites
2007-12-29

ABSTRACT Allelic replacement in staphylococci is frequently aided by antibiotic resistance markers that replace the gene(s) of interest. In multiply modified strains, the number of mutated genes usually correlates with the number of selection markers in the strain's chromosome. Site-specific recombination systems are capable of eliminating such markers, if they are flanked by recombinase recognition sites. In this study, a Cre- lox setting was established that allowed the efficient removal of resistance genes from the genomes of Staphylococcus carnosus and S. aureus . Two cassettes conferring resistance to erythromycin or kanamycin were flanked with wild-type or mutant lox sites, respectively, and used to delete single genes and an entire operon. After transformation of the cells with a newly constructed cre expression plasmid (pRAB1), genomic eviction of the resistance genes was observed in approximately one out of ten candidates analyzed and subsequently verified by PCR. Due to its thermosensitive origin of replication, the plasmid was then easily eliminated at nonpermissive temperatures. We anticipate that the system presented here will prove useful for generating markerless deletion mutants in staphylococci.
Photophysics and Nonlinear Optical Properties of Tetra- and Octabrominated Silicon Naphthalocyanines
2007-12-29

The effect of the number of bromide substituents on the photophysical and nonlinear optical properties of the tetrabrominated naphthalocyanine Br4(tBu2PhO)4NcSi[OSi(Hex)3]2 (1) and the octabrominated naphthalocyanine Br8NcSi[OSi(Hex)3]2 (2) has been investigated through various spectroscopic techniques. Absorption and emission of 1 and 2 have been studied at room temperature and 77 K to determine the spectral properties of the ground and the excited states and the lifetimes and quantum yields of formation of the excited states. There is a moderate increase of the quantum yield of the triplet excited-state formation (PhiT = 0.10 vs 0.13) and a decrease of the triplet excited-state lifetime (tauT approximately 70 vs 50 mus) from 1 to 2. These can be attributed to the stronger heavy atom effect produced by the larger number of peripheral bromide substituents in 2 considering that an excited state with a triplet manifold is involved in the excitation dynamics of both complexes 1 and 2. The quantum yields of the singlet oxygen formation (PhiDelta) upon irradiation of 1 and 2 at 355 nm were also evaluated, and a value of PhiDelta(1) = PhiDelta(2) = 0.16 was obtained. In addition to that, octabrominated complex 2 displays a larger decrease of nonlinear optical transmission for nanosecond pulses at 532 nm with respect to the tetrabrominated complex 1. The nanosecond Z-scan experiments reveal that 1 and 2 exhibit both a reverse saturable absorption and a nonlinear refraction at 532 nm. However, both the sign and the magnitude of the nonlinear refraction change from 1 to 2. For picosecond Z-scan in the visible spectral region, these two complexes exhibit only reverse saturable absorption, and the excited-state absorption cross-section increases at longer wavelengths.
SIGMA MESON PRODUCTION IN HEAVY ION COLLISIONS AT INTERMEDIATE ENERGIES
2007-12-30

The production of the sigma (σ) meson is investigated in the quantum molecular dynamics model for the p+A reactions with the nuclei A being 12 C , 40 Ca and 208 Pb at the incident proton energies E p = 1.50 GeV . The simulation results indicates a distinctive A dependence of the sigma production, that is, the increase of A is followed by an increase of the production cross-sections. The σ meson production in proton induced reactions is strongly medium-dependent, and the produced σ mesons decaying in a denser medium experience a stronger mass shift towards lower masses. This mass shift is an experimentally accessible observable in the final state pion pairs which did not suffer reabsorption by the surrounding nucleons. It is pointed out that the ratio of the simulation results of measurable σ mesons (in the form of two pions) cross-sections as a function of the sigma invariant-mass from various reactions opens the possibility to address experimentally the mass shift of the σ in a dense nuclear environment.
Some existence results for the Toda system on closed surfaces
2007-12-31

Given a compact closed surface \\Sigma , we consider the generalized Toda system of equations on \\Sigma : - \\Delta u_i = \\sum_{j=1}^2 \\rho_j a_{ij} \\left( \\frac{h_j e^{u_j}}{\\int_\\Sigma h_j e^{u_j} dV_g} - 1 \\right) for i = 1, 2 , where \\rho_1, \\rho_2 are real parameters and h_1, h_2 are smooth positive functions. Exploiting the variational structure of the problem and using a new minimax scheme we prove existence of solutions for generic values of \\rho_1 and for \\rho_2 &lt; 4 \\pi .
Successful Coil Embolization of a Ruptured Gastroduodenal Artery Aneurysm
2007-12-31

Aneurysms of the gastroduodenal artery are rare. Reported here is the case of a 60-year-old woman suffering from the covered rupturing of a twin aneurysm of the gastroduodenal artery. The patient presented herself in the surgical emergency unit with abdominal discomfort. Diagnostics showed free fluid in the abdominal cavity together with anemia of 9.9 g/dL. A computed tomography scan and an angiography revealed the covered rupturing of a twin aneurysm of the gastroduodenal artery, which was treated by endovascular coiling of the gastroduodenal and pancreaticoduodenal arteries. The patient's hemoglobin level remained stable after treatment, and she was released from the hospital after 18 days. Visceral artery aneurysms are rare. Although endovascular therapy is preferred in cases involving active bleeding, surgery remains the primary therapy in those cases in which bleeding becomes uncontrollable.
Stable discretization of scalar and constrained vectorial Perona–Malik equation
2007-12-31

We survey recent results on analysis and numerics of the scalar Perona–Malik equation. A vectorial Perona–Malik equation is introduced to evolve unit vector fields for directional diffusion. For both cases, scalar and vectorial, fully discrete schemes are proposed which fulfill a discrete energy law, and satisfy a discrete sphere constraint in the vectorial case. Computational experiments are provided to illustrate quantitative behaviors, and compare with scalar total variation flow and heat flow of p -harmonic maps.
How large is liquidity risk in an automated auction market?
2007-12-31

We introduce a new empirical methodology that models liquidity risk over short time periods for impatient traders who submit market orders. Using Value-at-Risk type measures, we quantify the liquidity risk premia for portfolios and individual stocks traded on the automated auction market Xetra. The specificity of our approach relies on the adequate econometric modelling of the potential price impact incurred by the liquidation of a portfolio. We study the sensitivity of liquidity risk towards portfolio size and traders' time horizon, and interpret its diurnal variation in the light of market microstructure theory.