3,267 research outputs found

    Electromagnetic and corpuscular emission from the solar flare of 1991 June 15: Continuous acceleraton of relativistic particles

    Get PDF
    Data on X-,γ-ray, optical and radio emission from the 1991 June 15 solar flare are considered. We have calculated the spectrum of protons that producesγ-rays during the gradual phase of the flare. The primary proton spectrum can be described as a Bessel-function-type up to 0.8 GeV and a power law with the spectral index ≈3 from 0.8 up to 10 GeV or above. We have also analyzed data on energetic particles near the Earth. Their spectrum differed from that of primary protons producingγ-ray line emission. In the gradual phase of the flare additional pulses of energy release occurred and the time profiles of cm-radio emission andγ-rays in the 0.8–10 MeV energy band and above 50 MeV coincided. A continuous and simultaneous stochastic acceleration of the protons and relativistic electrons at the gradual phase of the flare is considered as a natural explanation of the data

    Cosmic ray tables - Asymptotic directions, variational coefficients and cut-off rigidities IQSY instruction manual no. 10

    Get PDF
    Cosmic ray deflections in geomagnetic field, variational coefficients, and diurnal intensity variations - table

    Forecasting basketball players’ performance using sparse functional data

    Get PDF
    Statistics and analytic methods are becoming increasingly important in basketball. In particular, predicting players’ performance using past observations is a considerable challenge. The purpose of this study is to forecast the future behavior of basketball players. The available data are sparse functional data, which are very common in sports. So far, however, no forecasting method designed for sparse functional data has been used in sports. A methodology based on two methods to handle sparse and irregular data, together with the analogous method and functional archetypoid analysis is proposed. Results in comparison with traditional methods show that our approach is competitive and additionally provides prediction intervals. The methodology can also be used in other sports when sparse longitudinal data are available

    Neurofilaments form flexible bundles during neuritogenesis in culture and in mature axons in situ

    Get PDF
    Neurofilaments (NFs) undergo cation-dependent phospho-mediated associations with each other and other cytoskeletal elements that support axonal outgrowth. Progressive NF-NF associations generate a resident, bundled population that undergoes exchange with transporting NFs. We examined the properties of bundled NFs. Bundles did not always display a fully linear profile but curved and twisted at various points along the neurite length. Bundles retracted faster than neurites and retracted bundles did not expand following extraction with Triton, indicating that they coiled passively rather than due to pressure from the cell. Bundles consisted of helically wound NFs, which may provide flexibility necessary for turning of growing axons during pathfinding. Interactions between NFs and other cytoskeletal elements may be disrupted en masse during neurite retraction or regionally during remodeling. It is suggested that bundles within long axons that cannot be fully retracted into the soma could provide maintain proximal support yet still allow more distal flexibility for remodeling and changing direction during pathfinding

    Fetal MRI in management of complicated meconium ileus: Prenatal and surgical imaging

    Get PDF
    Objective To review fetal MRI cases surgically proven to have meconium ileus (MI) and obstruction, describe the common fetal MRI findings that distinguish cases of complicated MI, and to compare these findings with surgical images and perinatal outcomes. Method We performed a retrospective review of all fetal MRI examinations and the corresponding medical record from our tertiary care children's hospital over an 18‐month period. Postnatal management and outcomes were reviewed for these patients, and those patients with surgical or postmortem diagnosis of complicated MI were included in the study. Results Our analysis revealed 7 cases. In this cohort, 3 imaging features of the fetal bowel were repeatedly seen: gradient appearance of intraluminal bowel contents, abnormally localized meconium signal, and collapsed appearance of the colon on MRI. Surgical diagnoses confirmed MI. All live‐born infants underwent surgical repair. Conclusion Fetal MRI should be included in the diagnostic algorithm of any pregnancy where fetal bowel obstruction is suspected to better risk stratify patients

    Toward a descriptive model of solar particles in the heliosphere

    Get PDF
    During a workshop on the interplanetary charged particle environment held in 1987, a descriptive model of solar particles in the heliosphere was assembled. This model includes the fluence, composition, energy spectra, and spatial and temporal variations of solar particles both within and beyong 1 AU. The ability to predict solar particle fluences was also discussed. Suggestions for specific studies designed to improve the basic model were also made

    Public interest in hyaluronic acid injections for knee osteoarthritis in the United States and Europe: An international Google Trends analysis

    Get PDF
    BACKGROUND: Hyaluronic acid injections remain a common nonsurgical alternative for the treatment of knee osteoarthritis despite limited clinical evidence and varying global recommendations regarding its use. We used the Google Trends tool to provide a quantitative analysis of public interest in hyaluronic acid injections for knee osteoarthritis in the United States and Europe. METHODS: We customized Google Trends parameters to obtain search data from January 2009 to December 2019 in both the United States and Europe. Combinations of arthritis , osteoarthritis , hyaluronic acid , knee arthritis , knee osteoarthritis , and knee injection were entered into the Google Trends tool, and trend analyses were performed. RESULTS: The models generated to describe public interest in hyaluronic acid for knee injections in both the United States and Europe showed increased Google queries as time progressed ( CONCLUSIONS: Our results indicate a significant increase in Google queries related to hyaluronic acid injections for knee osteoarthritis since 2009 in both the United States and Europe. Our models suggest that despite mixed evidence supporting its use, orthopedic surgeons should expect continued public interest in hyaluronic acid for knee osteoarthritis. The results of our study may help to prepare surgeons for patient inquiries, inform the creation of evidence-based shared decision-making tools, and direct future research

    Motif Statistics and Spike Correlations in Neuronal Networks

    Get PDF
    Motifs are patterns of subgraphs of complex networks. We studied the impact of such patterns of connectivity on the level of correlated, or synchronized, spiking activity among pairs of cells in a recurrent network model of integrate and fire neurons. For a range of network architectures, we find that the pairwise correlation coefficients, averaged across the network, can be closely approximated using only three statistics of network connectivity. These are the overall network connection probability and the frequencies of two second-order motifs: diverging motifs, in which one cell provides input to two others, and chain motifs, in which two cells are connected via a third intermediary cell. Specifically, the prevalence of diverging and chain motifs tends to increase correlation. Our method is based on linear response theory, which enables us to express spiking statistics using linear algebra, and a resumming technique, which extrapolates from second order motifs to predict the overall effect of coupling on network correlation. Our motif-based results seek to isolate the effect of network architecture perturbatively from a known network state
    corecore