1,928 research outputs found

    Pain modulation by illusory body rotation: A new way to disclose the interaction between the vestibular system and pain processing

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    Background Clinical and experimental evidence advocates a structural and functional link between the vestibular and other sensory systems. For instance, visuo‐vestibular and vestibular–somatosensory interactions have been widely reported. However, whether visual inputs carrying vestibular information can modulate pain is not yet clear. Recent evidence using natural vestibular stimulation or moving visual stimuli, points at an unspecific effect of distraction. Methods By using immersive virtual reality (VR), we created a new way to prompt the vestibular system through the vision of static visual cues, studying the possible interaction with pain. Twenty‐four healthy participants were visually immersed in a virtual room which could appear with five different degrees of rotation in the sagittal axis, either towards the right, left or with no rotation. Participants' heat pain thresholds and subjective reports of perceived body rotation, sense of presence and attention were measured. Results ‘Being’ in a tilted room induced the sensation of body rotation in our participants, even though they were always in an upright position. We also found that rotating the visual scenario can modulate the participants' pain thresholds, determining a significant increase when a left tilt is displayed. In addition, a positive correlation between the perceived body midline rotation and pain threshold was found when the virtual room was titled 15 degrees toward the left. Importantly, all VR conditions were found to be equally distractive. Conclusions Vestibular information present in static visual cues can modulate experimentally‐induced acute pain according to a side‐dependent manner and bypassing supramodal attentional mechanisms. These findings may help refining pain management approaches based on multimodal stimulation. Significance This study explored how the visualization of static environments in immersive virtual reality can lead to pain threshold modulation through the activation of the vestibular system. Immersion into rotated virtual environments led to the illusory sensation of body rotation, and this sensation was found to be related with a modulation of pain perception. Possible analgesic effects due to distraction could be ruled out. These results expand our current knowledge about how the visual, vestibular and somatosensory (pain) systems interact. These findings may influence future pain treatment strategies based on multisensory stimulation

    Satellite Selection Methodology for Horizontal Navigation and Integrity Algorithms

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    With the new upcoming GNSS constellation in the future it might no longer be possible to use all satellites in view for navigation due to limited tracking channels. This is in particular true in the context of Advanced Receiver Autonomous Integrity Monitoring (ARAIM), where the use of dual frequency is favorable to mitigate ionospheric disturbances. To address the issues of limited channels we propose two different satellites selection strategies adapted for Horizontal ARAIM in this paper. First a bare geometric approach which comes with almost no additional computation effort at the cost of less stable results. And second a heuristic optimization which improves selection results significantly while adding additional computational effort. Both approaches are compared to brute force selected best sets in terms of resulting protection levels, computational cost and achieved ARAIM availability. Results show the general applicability of both presented selection methods in Horizontal ARAIM. Using limited sets instead of all satellites in view can still provide global availability. Depending on the method more or less satellites are necessary to ensure sufficiently small and stable protection levels

    The Distribution of Active Galactic Nuclei in Clusters of Galaxies

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    We present a study of the distribution of AGNs in clusters of galaxies with a uniformly selected, spectroscopically complete sample of 35 AGNs in eight clusters of galaxies at z = 0.06 → 0.31. We find that the 12 AGNs with L_X > 10^42 ergs s^-1 in cluster members more luminous than a rest-frame M_+R 10^41 ergs s^-1 do not show evidence for greater central concentration than inactive cluster members, nor evidence for a different kinematic or substructure distribution. As we do see clear differences in the spatial and kinematic distributions of the blue Butcher-Oemler and red cluster galaxy populations, any difference in the AGN and inactive galaxy population must be less distinct than that between these two pairs of populations. Comparison of the AGN fraction selected via X-ray emission in this study to similarly selected AGNs in the field indicates that the AGN fraction is not significantly lower in clusters, contrary to AGNs identified via visible wavelength emission lines, but similar to the approximately constant radio-selected AGN fraction in clusters and the field. We also find significant evidence for variation in the AGN fraction between clusters and explore the dependence of cluster AGN fraction on redshift, velocity dispersion, amount of cluster substructure, and fraction of Butcher-Oemler galaxies. While we see weak evidence for several trends, there are several correlations between these four parameters in our small sample of eight clusters that preclude identification of which one(s) most strongly influence the cluster AGN fraction

    First Measurement of a Rapid Increase in the AGN Fraction in High-Redshift Clusters of Galaxies

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    We present the first measurement of the AGN fraction in high-redshift clusters of galaxies (z~0.6) with spectroscopy of one cluster and archival data for three additional clusters. We identify 8 AGN in all four of these clusters from the Chandra data, which are sensitive to AGN with hard X-ray (2-10keV) luminosity L_{X,H} > 10^43 erg/s in host galaxies more luminous than a rest frame M_R < -20 mag. This stands in sharp contrast to the one AGN with L_{X,H} > 10^43 erg/s we discovered in our earlier study of eight low-redshift clusters with z=0.06-0.31 (average z~0.2). Three of the four high-redshift cluster datasets are sensitive to nearly L_{X,H} > 10^42 erg/s and we identify seven AGN above this luminosity limit, compared to two in eight, low-redshift clusters. Based on membership estimates for each cluster, we determine that the AGN fraction at z~0.6 is f_A(L_X>10^42;M_R<-20) = 0.028 (+0.019/-0.012) and f_A(L_X>10^43;M_R<-20) = 0.020 (+0.012/-0.008). These values are approximately a factor of 20 greater than the AGN fractions in lower-redshift (average z~0.2) clusters of galaxies and represent a substantial increase over the factors of 1.5 and 3.3 increase, respectively, in the measured space density evolution of the hard X-ray luminosity function over this redshift range. Potential systematic errors would only increase the significance of our result. The cluster AGN fraction increases more rapidly with redshift than the field and the increase in cluster AGN indicates the presence of an AGN Butcher-Oemler Effect.Comment: ApJL Accepted, 5 pages, 2 figure

    Antimicrobial susceptibility profile and research of mec A and erm genes in coagulase-negative staphylococci isolated from platelet concentrates bags

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    In recent years, several studies have described the clinical impact of bacterial infection associated with transfusion of platelet concentrates (PCs). Among the blood components, PCs are responsible for the highest rates of bacterial contamination as well as septic transfusion reactions. We assessed antimicrobial susceptibility profile, resistance to methicillin (MRCoNS), and resistance to macrolides, lincosamides and streptogramins of group B (MLSB) of 16 coagulase-negative staphylococci (CoNS) isolates from an investigation in 691 PCs bags. We then compared conventional and automated phenotypic methods, disc diffusion test (DD) and VITEK(r) 2, respectively as well as phenotypic and genotypic methods (Polymerase Chain Reaction - PCR). All CoNS were susceptible to vancomycin. The disc diffusion test characterized 18.75% as MRCoNS and 37.5% with inducible resistance to MLSB (iMLSB), and with VITEK(r) 2, 6.3% and 31.25%, respectively. The mecA gene was detected in 18.75% and the erm gene in 31.25% of the isolates. In this study, we found equal percentage values between presence of the mecA gene by PCR and resistance to methicillin using cefoxitin by DD test, evidence of the erm gene by PCR, and iMLSB resistance by automation (VITEK(r) 2). Moreover, we identified three strains with beta-lactamase overproduction, and the occurrence of a bigger mistake was verified when automation was compared with DD test. And we observed that D-test was the most reliable for the detection of iMLSB resistance in Staphylococcus sp

    Modulation of pain threshold by virtual body ownership

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    Appropriate sensorimotor correlations can result in the illusion of ownership of exogenous body parts. Nevertheless, whether and how the illusion of owning a new body part affects human perception, and in particular pain detection, is still poorly investigated. Recent findings have shown that seeing one's own body is analgesic, but it is not known whether this effect is transferable to newly embodied, but exogenous, body parts. In recent years, results from our laboratory have demonstrated that a virtual body can be felt as one's own, provided realistic multisensory correlations

    What Color is My Arm? Changes in Skin Color of an Embodied Virtual Arm Modulates Pain Threshold

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    It has been demonstrated that visual inputs can modulate pain. However, the influence of skin color on pain perception is unknown. Red skin is associated to inflamed, hot and more sensitive skin, while blue is associated to cyanotic, cold skin. We aimed to test whether the color of the skin would alter the heat pain threshold. To this end, we used an immersive virtual environment where we induced embodiment of a virtual arm that was co-located with the real one and seen from a first-person perspective. Virtual reality allowed us to dynamically modify the color of the skin of the virtual arm. In order to test pain threshold, increasing ramps of heat stimulation applied on the participants' arm were delivered concomitantly with the gradual intensification of different colors on the embodied avatar's arm. We found that a reddened arm significantly decreased the pain threshold compared with normal and bluish skin. This effect was specific when red was seen on the arm, while seeing red in a spot outside the arm did not decrease pain threshold. These results demonstrate an influence of skin color on pain perception. This top-down modulation of pain through visual input suggests a potential use of embodied virtual bodies for pain therapy

    Wide-Field Chandra X-Ray Observations of AGN in Abell 85 & Abell 754

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    To better understand the mechanism or mechanisms that lead to AGN activity today, we measure the X-ray AGN fraction in a new sample of nearby clusters and examine how it varies with galaxy properties, projected cluster-centric radius, and cluster velocity dispersion. We present new wide-field Chandra X-ray Observatory observations of Abell 85, Abell 754 and the background cluster Abell 89B out to their virial radii. Out of seventeen X-ray sources associated with galaxies in these clusters, we classify seven as X-ray AGN with L_{X,B} > 10^{41} erg/s. Only two of these would be classified as AGN based on their optical spectra. We combine these observations with archival data to create a sample of X-ray AGN from six z < 0.08 clusters and find that 3.4+1.1/-0.8% of M_R 10^{41} erg/s. We find that more X-ray AGN are detected in more luminous galaxies and attribute this to larger spheriods in more luminous galaxies and increased sensitivity to lower Eddington-rate accretion from black holes in those spheroids. At a given X-ray luminosity limit, more massive black holes can be accreting less efficiently, yet still be detected. If interactions between galaxies are the principal drivers of AGN activity, then the AGN fraction should be higher in lower velocity dispersion clusters and the outskirts of clusters. However, the tendency of the most massive and early-type galaxies to lie in the centers of the richest clusters could dilute such trends. While we find no variation in the AGN fraction with projected cluster-centric radius, we do find that the AGN fraction increases significantly from 2.6+1.0/-0.8% in rich clusters to 10.0+6.2/-4.3% in those with lower velocity dispersions.Comment: Accepted by Astrophysical Journal, 17 pages using emulateapj.cls, 10 B & W Figures (degraded): Full resolution paper available at http://www.astronomy.ohio-state.edu/~sivakoff/AGN/XAGN_A85_A754.pd

    Gambaran Implementasi Regulasi Kawasan Tanpa Rokok Dalam Upaya Menurunkan Prevalensi Perokok Di Kabupaten Blitar

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    Blitar Regency already has a Regulation No. 1 of  2019 concerning Smoke-Freee Areas, carrying out technical capacity building for health workers in Stop Smoking Efforts (UBM) services. However, the number of smokers in Blitar Regency has not decreased, which is still 28.0%. This study aims to provide a descriptive description of the KTR regulations implemented by health facilities in Blitar Regency.  This is a type of quantitative research with a descriptive study with a cross-sectional design. The research material used was secondary data from KTR and Cigarette reports in Blitar Regency in 2022 for the PTM program. The number of smokers aged 10 - 18 years was 7678 people (4.47%) consisting of 81.61% male smokers and 18.39% female smokers. The number of schools that have implemented KTR is 894 (79.32%) and those that have not are 233 (20.68%). There are 3 clinics (12%) and 17 independent doctor practices (22.67%) that have implemented UBM. The results of the multiple linear regression test, both from the P value (Sig. 0.785) and the calculated F (0.244), both show that there is no significance between schools that have KTR or not and the number of smokers aged 10 - 18 years, P value > α 0.05 and F count < F table (3.47). The implementation of KTR in schools needs to be achieved up to 100% and also in other places where KTR is mandatory because the long-term goal is to reduce the prevalence of the number of smokers
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