229 research outputs found

    Was the GLE on May 17, 2012 linked with the M5.1-class flare the first in the 24th solar cycle?

    Full text link
    On May 17, 2012 an M5.1-class flare exploded from the sun. An O-type coronal mass ejection (CME) was also associated with this flare. There was an instant increase in proton flux with peak at 100\geq 100 MeV, leading to S2 solar radiation storm level. In about 20 minutes after the X-ray emission, the solar particles reached the Earth.It was the source of the first (since December 2006) ground level enhancement (GLE) of the current solar cycle 24. The GLE was detected by neutron monitors (NM) and other ground based detectors. Here we present an observation by the Tupi muon telescopes (Niteroi, Brazil, 220.9S22^{0}.9 S, 430.2W43^{0}.2 W, 3 m above sea level) of the enhancement of muons at ground level associated with this M5.1-class solar flare. The Tupi telescopes registered a muon excess over background 20%\sim 20\% in the 5-min binning time profile. The Tupi signal is studied in correlation with data obtained by space-borne detectors (GOES, ACE), ground based neutron monitors (Oulu) and air shower detectors (the IceTop surface component of the IceCube neutrino observatory). We also report the observation of the muon signal possibly associated with the CME/sheath striking the Earth magnetosphere on May 20, 2012. We show that the observed temporal correlation of the muon excess observed by the Tupi muon telescopes with solar transient events suggests a real physical connection between them. Our observation indicates that combination of two factors, the low energy threshold of the Tupi muon telescopes and the location of the Tupi experiment in the South Atlantic Anomaly region, can be favorable in the study and detection of the solar transient events. Our experiment provides new data complementary to other techniques (space and ground based) in the study of solar physics.Comment: 9 pages, 10 figure

    Analysis of angular reading distortions of photographic images

    Get PDF
    CONTEXTUALIZAÇÃO: A biofotogrametria é uma técnica difundida na área da saúde e, apesar dos cuidados metodológicos, há distorções nas leituras angulares das imagens fotográficas.\ud OBJETIVO: Mensurar o erro das medidas angulares em imagens fotográficas com diferentes resoluções digitais em um objeto com ângulos pré-demarcados.\ud MÉTODOS: Utilizou-se uma esfera de borracha com 52 cm de circunferência. O objeto foi previamente demarcado com ângulos de 10º, 30º, 60º e 90º, e os registros fotográficos foram realizados com o eixo focal da câmera a três metros de distância e perpendicular ao objeto, sem utilização de zoom óptico e com resolução de 3, 5 e 10 Megapixels (Mp). Todos os registros fotográficos foram armazenados, e os valores angulares foram analisados por um experimentador previamente treinado, utilizando o programa ImageJ. As aferições das medidas foram realizadas duas vezes, com intervalo de 15 dias entre elas. Posteriormente, foram calculados os valores de acurácia, erro relativo e em graus, precisão e Coeficiente de Correlação Intraclasse (ICC).\ud RESULTADOS: Quando analisado o ângulo de 10º, a média da acurácia das medidas foi maior para os registros com resolução de 3 Mp em relação às resoluções de 5 e 10 Mp. O ICC foi considerado excelente para as três resoluções de imagem analisadas e, em relação aos ângulos analisados nos registros fotográficos, pôde-se verificar maior acurácia, menor erro relativo e em graus e maior precisão para o ângulo de 90º, independentemente da resolução da imagem.\ud CONCLUSÃO: Os registros fotográficos realizados com a resolução de 3 Mp proporcionaram medidas de maiores valores de acurácia e precisão e menores valores de erro, sugerindo ser a resolução mais adequada para gerar imagem de ângulos de 10º e 30º.Background: Although photogrammetry is a widespread technique in the health field, despite of the methodological efforts distortions in the angular readings of the images are common. Objective: To measure the error of angular measurements in photo images with different digital resolutions in an object with pre-determined angles. Method: We used a rubber ball with 52 cm in circumference. The object was previously marked with angles of 10 degrees, 30 degrees, 60 degrees and 90 degrees degrees. The photographic records were performed with the focal axis of the camera perpendicular and three meters away from the object, without the use of optical zoom and a resolution of 3, 5 and 10 Megapixels (Mp). All photographic records were stored and a previously trained experimenter using the computer program Image J analyzed the angular values of each photo. The measurements were performed twice within a fifteen-days interval. Subsequently, we calculated the accuracy, relative error and error in degrees values, precision and the Intraclass Correlation Coefficient (ICC). Results: When analyzing the angle of 10 degrees, the average accuracy of measurements was higher for those records of 3 Mp resolution compared to 5 and 10 Mp resolutions. The ICC was considered excellent for all resolutions. With regards to the analyzed angles in photographic records, it was possible to verify that the 90-degree angle photographs were more accurate, had lower relative error and error in degrees, and were more precise, regardless of image resolution. Conclusion: The photographs records that were taken with a 3 Mp resolution provided great accuracy and precision measurements and lower errors values, suggesting to be the proper resolution to generate image of angles of 10 degrees and 30 degrees

    Impact of Glycemic and Blood Pressure Variability on Surrogate Measures of Cardiovascular Outcomes in Type 2 Diabetic Patients

    Get PDF
    OBJECTIVE—The effect of glycemic variability (GV) on cardiovascular risk has not been fully clarified in type 2 diabetes. We evaluated the effect of GV, blood pressure (BP), and oxidative stress on intima-media thickness (IMT), left ventricular mass index (LVMI), flow-mediated dilation (FMD), and sympathovagal balance (low frequency [LF]/high frequency [HF] ratio) in 26 type 2 diabetic patients (diabetes duration 4.41 6 4.81 years; HbA1c 6.70 6 1.25%) receiving diet and/or metformin treatment, with no hypotensive treatment or complications. RESEARCH DESIGN AND METHODS—Continuous glucose monitoring (CGM) data were used to calculate mean amplitude of glycemic excursion (MAGE), continuous overall net glycemic action (CONGA)-2, mean blood glucose (MBG), mean postprandial glucose excursion (MPPGE), and incremental area under the curve (IAUC). Blood pressure (BP), circadian rhythm, and urinary 15-F2t-isoprostane (8-iso-prostaglandin F2a [PGF2a]) were also evaluated. Subjects were divided into dipper (D) and nondipper (ND) groups according to DBP. RESULTS—IMT and LVMIwere increased inNDversusD(0.7760.08 vs. 0.6860.13 [P=0.04] and 67 6 14 vs. 55 6 11 [P = 0.03], respectively). MBG, MAGE, and IAUC were significantly associated with LF/HF ratio at night (r = 0.50, P = 0.01; r = 0.40, P = 0.04; r = 0.41, P = 0.04, respectively), MPPGE was negatively associated with FMD (r =20.45, P = 0.02), andCONGA-2was positively associatedwith LVMI (r=0.55, P=0.006).TheDsystolic BP was negatively associated with IMT (r =20.43, P = 0.03) andwith LVMI (r =20.52, P = 0.01). Urinary 8-iso-PGF2a was positively associated with LVMI (r = 0.68 P , 0.001). CONCLUSIONS—An impaired GV and BP variability is associated with endothelial and cardiovascular damage in short-term diabetic patients with optimal metabolic control. Oxidative stress is the only independent predictor of increased LV mass and correlates with glucose and BP variability

    Maximum voluntary clenching and unilateral chewing in patients with mild-moderate TMD

    Get PDF
    Temporomandibular disorders (TMD) consist of a number of clinical problems that involve the masticatory muscles, the temporomandibular joint and associated structures. The aim of the study was to quantitatively compare electromyographic (EMG) parameters of patients with mild-moderate TMD and healthy subjects. Twenty patients with mild-moderate TMD (5 men, 15 women, 22–56 y) and 19 healthy subjects (9 men, 10 women, 21–49 y) were analyzed. sEMG of the left and right masseter and temporalis anterior muscles was recorded using a wireless device (TMJoint, BTS, Italy). Each subject performed a 5 s-maximum voluntary contraction (MVC) with the teeth in intercuspal position (CLENCH), and one with two 10 mm-thick cotton rolls positioned on the mandibular second premolars/first molars (COT). EMG activity was further recorded during unilateral, right and left, gum chewing. EMG potentials of both MVC and chewing were standardized as percentages of the potentials obtained during COT recording [1]. During MVC, EMG activities were less symmetric and had a larger torque component in TMD patients than in healthy subjects (muscular asymmetry: 10.4±9.1% vs 4.4±4.2%, Student’s t-test, p=0.013; torque: 9.8±10.9% vs 4.4±4.0%, p=0.047). During chewing, all healthy subjects had a good coordination between masseter and temporalis contractions, with a prevalent activity of the working-side muscles. Among TMD patients, instead, 9 subjects performed at least one of their unilateral chewing tests with an altered muscular coordination. EMG activity of TMD patients was less coordinated than that of healthy subjects, with a larger variability between chewing cycles (Hotelling’s ellipse area: 2275±2734% vs 1010±845%, Student’s t-test, p=0.061). sEMG analysis could be a useful tool to detect functionally altered stomatognathic muscular coordination. Dote ricerca: FSE, Regione Lombardi

    Which patellofemoral joint imaging features are associated with patellofemoral pain? Systematic review and meta-analysis

    Get PDF
    Objectives: To review the association between patellofemoral joint (PFJ) imaging features and patellofemoral pain (PFP). Design: A systematic review of the literature from AMED, CiNAHL, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PEDro, EMBASE and SPORTDiscus was undertaken from their inception to September 2014. Studies were eligible if they used magnetic resonance imaging (MRI), computed tomography (CT), ultrasound (US) or x-ray (XR) to compare PFJ features between a PFP group and an asymptomatic control group in people < 45 years of age. A pooled meta-analysis was conducted and data was interpreted using a best evidence synthesis. Results: Forty studies (all moderate to high quality) describing 1,043 people with PFP and 839 controls were included. Two features were deemed to have a large standardised mean difference (SMD) based on meta-analysis: an increased MRI bisect offset at 0° knee flexion under load (0.99; 95% CI: 0.49, 1.49) and an increased CT congruence angle at 15° knee flexion, both under load (1.40 95% CI: 0.04, 2.76) and without load (1.24; 95% CI: 0.37,2.12). A medium SMD was identified for MRI patella tilt and patellofemoral contact area. Limited evidence was found to support the association of other imaging features with PFP. A sensitivity analysis showed an increase in the SMD for patella bisect offset at 0° knee flexion (1.91; 95% CI: 1.31,2.52) and patella tilt at 0° knee flexion (0.99; 95% CI: 0.47,1.52) under full weight bearing. Conclusion: Certain PFJ imaging features were associated with PFP. Future interventional strategies may be targeted at these features
    corecore