1,560 research outputs found

    Structure of the magnetoionic medium around the FR Class I radio galaxy 3C 449

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    The goal of this work is to constrain the strength and structure of the magnetic field associated with the environment of the radio source 3C 449, using observations of Faraday rotation, which we model with a structure function technique and by comparison with numerical simulations. We assume that the magnetic field is a Gaussian, isotropic random variable and that it is embedded in the hot intra-group plasma surrounding the radio source. For this purpose, we present detailed rotation measure images for the polarized radio source 3C 449, previously observed with the Very Large Array at seven frequencies between 1.365 and 8.385 GHz. We quantify the statistics of the magnetic-field fluctuations by deriving rotation measure structure functions, which we fit using models derived from theoretical power spectra. We quantify the errors due to sampling by making multiple two-dimensional realizations of the best-fitting power spectrum.We also use depolarization measurements to estimate the minimum scale of the field variations. We then make three-dimensional models with a gas density distribution derived from X-ray observations and a random magnetic field with this power spectrum. Under these assumptions we find that both rotation measure and depolarization data are consistent with a broken power-law magnetic-field power spectrum, with a break at about 11 kpc and slopes of 2.98 and 2.07 at smaller and larger scales respectively. The maximum and minimum scales of the fluctuations are around 65 and 0.2 kpc, respectively. The average magnetic field strength at the cluster centre is 3.5 +/-1.2 micro-G, decreasing linearly with the gas density within about 16 kpc of the nucleus.Comment: 19 pages; 14 figures; accepted for publication on A&A. For a high quality version use ftp://ftp.eso.org/pub/general/guidetti

    Clinical survey of neurosensory side-effects of mandibular parasymphyseal bone harvesting

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    The aim of the present survey was to assess neurosensory disturbances and/or tooth-pulp sensitivity losses after mandibular parasymphyseal bone-harvesting procedures. Twenty-eight harvesting areas in 16 patients were surveyed. Mucosal and skin sensitivity of the chin/lower lip, divided into four regions, were determined via Pointed-Blunt and Two-Point-Discrimination Tests. Pulp sensitivity of the mandibular teeth from the left second bicuspid to the right second bicuspid was tested by cold vitality preoperatively and 12 months postoperatively. Teeth were grouped according to sensitivity alterations and distance from the harvesting defects, as measured on CT scans, and statistically significant differences sought. At 12 months, 29% of preoperatively vital cuspids overlying the harvesting defects revealed pulp-sensitivity losses; no patient reported anaesthesia or analgesia; hypoaesthesia was present in 4% (8 sites; 2 patients), hypoalgesia was present in 3% (5 sites; 2 patients) and Two-Point-Discrimination Tests yielded pathologic responses in 5% of tested areas (10 sites; 4 patients). Teeth with and without pulp sensitivity changes were statistically indistinguishable regarding distances between root apices or mental foramen and the harvesting defect. The loss of pulp sensitivity in any tooth cannot be predicted simply on the basis of the distance between its apex and the harvesting osteotomy line

    Cerebral hemodynamics on MR perfusion images before and after bypass surgery in patients with giant intracranial aneurysms

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    Preoperative assessment of the anatomy and dynamics of cerebral circulation for patients with giant intracranial aneurysm can improve both outcome prediction and therapeutic approach. The aim of our study was to use perfusion MR imaging to evaluate cerebral hemodynamics in such patients before and after extraintracranial high-flow bypass surgery. METHODS: Five patients with a giant aneurysm of the intracranial internal carotid artery underwent MR studies before, 1 week after, and 1 month after high-flow bypass surgery. We performed MR and digital subtraction angiography, and conventional and functional MR sequences (diffusion and perfusion). Surgery consisted of middle cerebral artery (MCA)-internal carotid artery bypass with saphenous vein grafts (n = 4) or MCA-external carotid artery bypass (n = 1). RESULTS: In four patients, MR perfusion study showed impaired hemodynamics in the vascular territory supplied by the MCA of the aneurysm side, characterized by significantly reduced mean cerebral blood flow (CBF), whereas mean transit time (MTT) and regional cerebral blood volume (rCBV) were either preserved, reduced, or increased. After surgery, angiography showed good canalization of the bypass graft. MR perfusion data obtained after surgery showed improved cerebral hemodynamics in all cases, with a return of CBF index (CBFi), MTT, and rCBV to nearly normal values. CONCLUSION: Increased MTT with increased or preserved rCBV can be interpreted as a compensatory vasodilatory response to reduced perfusion pressure, presumably from compression and disturbed flow in the giant aneurysmal sac. When maximal vasodilation has occurred, however, the brain can no longer compensate for diminished perfusion by vasodilation, and rCBV and CBFi diminish. Bypass surgery improves hemodynamics, increasing perfusion pressure and, thus, CBFi. Perfusion MR imaging can be used to evaluate cerebral hemodynamics in patients with intracranial giant aneurysm.BACKGROUND AND PURPOSE: Preoperative assessment of the anatomy and dynamics of cerebral circulation for patients with giant intracranial aneurysm can improve both outcome prediction and therapeutic approach. The aim of our study was to use perfusion MR imaging to evaluate cerebral hemodynamics in such patients before and after extraintracranial high-flow bypass surgery. METHODS: Five patients with a giant aneurysm of the intracranial internal carotid artery underwent MR studies before, 1 week after, and 1 month after high-flow bypass surgery. We performed MR and digital subtraction angiography, and conventional and functional MR sequences (diffusion and perfusion). Surgery consisted of middle cerebral artery (MCA)-internal carotid artery bypass with saphenous vein grafts (n = 4) or MCA-external carotid artery bypass (n = 1). RESULTS: In four patients, MR perfusion study showed impaired hemodynamics in the vascular territory supplied by the MCA of the aneurysm side, characterized by significantly reduced mean cerebral blood flow (CBF), whereas mean transit time (MTT) and regional cerebral blood volume (rCBV) were either preserved, reduced, or increased. After surgery, angiography showed good canalization of the bypass graft. MR perfusion data obtained after surgery showed improved cerebral hemodynamics in all cases, with a return of CBF index (CBFi), MTT, and rCBV to nearly normal values. CONCLUSION: Increased MTT with increased or preserved rCBV can be interpreted as a compensatory vasodilatory response to reduced perfusion pressure, presumably from compression and disturbed flow in the giant aneurysmal sac. When maximal vasodilation has occurred, however, the brain can no longer compensate for diminished perfusion by vasodilation, and rCBV and CBFi diminish. Bypass surgery improves hemodynamics, increasing perfusion pressure and, thus, CBFi. Perfusion MR imaging can be used to evaluate cerebral hemodynamics in patients with intracranial giant aneurysm

    RSA, CMJ, Leger, 10m sprint responses to Pre-season training in semi-Professional Soccer Players

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    Aim: The aim of this study was to analyze RSA, CMJ, Leger, 10m sprint responses to Pre-season Training in Semi-Professional Soccer Players (SPSP). Considering that numerous studies1,2 highlighted the combination of high levels of physical, technical and tactical skills during a soccer match, the cure of physical training pose a particular attention on training load that generally increases up to 2.4 times during the pre-season period compared with the in-season3. Methods: Six SPSP (age: 23±7yr; BMI: 23.3±1.8) were requested to perform aerobic training over an 8-week period on alternate days with the functional strength training sessions and sprint training drills as prescribed by the coaches and strength and conditioning staff. Repeated Sprint Ability (RSA, Total Time –TT- and percentage of fatigue index -%FI), Leger, 10m sprint and Counter Mouvement Jump (CMJ) tests, were performed before and after pre-season soccer training. ANOVA for repeated measures was conducted to assess differences (p<0.05) with respect to pre seasonal training. Correlation was calculated between the percentage of variation (Δ) of each test. Results: Compared to the values recorded before the pre-season, improvement of Leger (3%) and %FI (17.6%) and a deterioration of TT (10%), 10m sprint (0.2%) and CMJ (2.4%) were found. In addition, we have found a main effect between before and after pre-seasonal training in TT (F(1,4)=60.2; p=0.001) and Leger (F(1,5)=25; p<0.005). ΔCMJ showed very large correlation with ΔLeger (r=-0.88) and nearly perfect with Δ%FI (r=0.93); while ΔLeger was largely correlated with Δ%FI (r=-0.69). Conclusions: Given that the cure of the physical preparation is considered as an important element in order to influence the final soccer game result, this study want to be useful information for the coach in order to maximize the best physical condition of the whole team relative to the beginning of the regular season

    Effects of add-on ultramicronized n-palmitol ethanol amide in patients suffering of migraine with aura. a pilot study

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    Background: Palmitoyl ethanol amide (PEA) is an endogenously produced substance showing anti-nociceptive effect through both receptor and non-receptor mediated effects at the level of different cellular and tissue sites. This study showed the results of a single blind study that was conducted to evaluate both the safety and the efficacy of ultramicronized PEA (umPEA; 1,200 mg/day) for up 90 days in patients suffering of Migraine with Aura (MA) treated with NSAIDs. Methods: A total of 20 patients, 8 male (33-56-years, average 41.4 ± 7.8) and 12 female (19-61-years, average 38.5 ± 11.9) with MA were admitted to our observation and diagnosed according to ICHD-3 criteria, they received umPEA (1,200 mg/day) in combination with NSAIDs for up to 90 days. They were revaluated at 30, 60, and 90 days after treatment. Results: umPEA administration induced a statistically significant and time dependent pain relief. In particular, these effects were evident at 60 days (male P = 0.01189; female P = < 0.01) and they lasted until the end of the study (male P = 0.0066; female P = 0.01473). Conclusion: Although further studies are needed, our findings indicate that in patients suffering of MA treatment with umPEA had good efficacy and safety which candidate this compound as a therapeutic tool in pain migraine management

    Fantastic animals as an experimental model to teach animal adaptation

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    Background: Science curricula and teachers should emphasize evolution in a mannercommensurate with its importance as a unifying concept in science. The concept of adaptationrepresents a first step to understand the results of natural selection. We settled an experimentalproject of alternative didactic to improve knowledge of organism adaptation. Students wereinvolved and stimulated in learning processes by creative activities. To set adaptation in a historicframe, fossil records as evidence of past life and evolution were considered.Results: The experimental project is schematized in nine phases: review of previous knowledge;lesson on fossils; lesson on fantastic animals; planning an imaginary world; creation of an imaginaryanimal; revision of the imaginary animals; adaptations of real animals; adaptations of fossil animals;and public exposition. A rubric to evaluate the student's performances is reported. The projectinvolved professors and students of the University of Modena and Reggio Emilia and of the "G.Marconi" Secondary School of First Degree (Modena, Italy).Conclusion: The educational objectives of the project are in line with the National Indications ofthe Italian Ministry of Public Instruction: knowledge of the characteristics of living beings, themeanings of the term "adaptation", the meaning of fossils, the definition of ecosystem, and theparticularity of the different biomes. At the end of the project, students will be able to graspparticular adaptations of real organisms and to deduce information about the environment in whichthe organism evolved. This project allows students to review previous knowledge and to form theirpersonalities

    Using dual eye tracking to uncover personal gaze patterns during social interaction

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    We report the personal eye gaze patterns of people engaged in face-to-face getting acquainted conversation. Considerable differences between individuals are underscored by a stability of eye gaze patterns within individuals. Results suggest the existence of an eye-mouth gaze continuum. This continuum includes some people showing a strong preference for eye gaze, some with a strong preference for mouth gaze, and others distributing their gaze between the eyes and mouth to varying extents. Additionally, we found evidence of within-participant consistency not just for location preference but also for the duration of fixations upon the eye and mouth regions. We also estimate that during a 4-minute getting acquainted conversation mutual face gaze constitutes about 60% of conversation that occurs via typically brief instances of 2.2 seconds. Mutual eye contact ranged from 0-45% of conversation, via very brief instances. This was despite participants subjectively perceiving eye contact occurring for about 70% of conversation. We argue that the subjective perception of eye contact is a product of mutual face gaze instead of actual mutual eye contact. We also outline the fast activity of gaze movements upon various locations both on and off face during a typical face-to-face conversation
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