659 research outputs found

    Current Concepts Imaging in COVID-19 and the Challenges for Low and Middle Income Countries

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    With nearly 3,800,000 cases and 270,000 deaths reported worldwide, COVID-19 is a global pandemic unlike any we have seen in our lifetimes (1). As early as 1995, the WHO was warning of a global infectious disease crisis, citing 30 new infectious diseases emerging in the past 20 years, loss of antibiotic effectiveness, low rates of immunization, poverty, and inadequate investment in public health contributing to the more than 17 million people dying each year from infectious diseases, principally in Low and Middle Income countries (LMIC) (2). Unlike previous infectious diseases, at the time of this writing over 63% of the total reported cases of COVID-19 are in 6 High Income Countries (HIC): USA, Italy, Spain, France, Germany and the UK. Information concerning the imaging findings in COVID-19 has been rapidly disseminated from the centers first affected by the pandemic. This article attempts to summarize the current state of knowledge regarding the imaging findings in COVID-19, focusing on pulmonary findings, and offer recommendation for the use of imaging for diagnosis and surveillance of COVID-19, particularly in LMIC

    pp-Process simulations with a modified reaction library

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    We have performed pp-process simulations with the most recent stellar (n,γ)(n,\gamma) cross sections from the "Karlsruhe Astrophysical Database of Nucleosynthesis in Stars" project (version v0.2, http://nuclear-astrophysics.fzk.de/kadonis). The simulations were carried out with a parametrized supernova type II shock front model (``γ\gamma process'') of a 25 solar mass star and compared to recently published results. A decrease in the normalized overproduction factor could be attributed to lower cross sections of a significant fraction of seed nuclei located in the Bi and Pb region around the NN=126 shell closure.Comment: 5 pages, 1 figure Proceedings "Nuclear Physics in Astrophysics NPA-III", Dresden/Germany (2007

    Penerapan Teori Backward Recursive Untuk Menentukan Jumlah Tenaga Kerja Dan Gaji Pada PT Xyz

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    Metode yang digunakan dalam penelitian ini adalah penggunaan Program Dinamik dengan perhitungan mundur (backward recursive) model matematis : fi(Si,Xi) = ri(Si,Xi) + f(i − 1)(S(i − 1),X(i − 1)) dimana i = nomor tahap (i = 1, 2, ..., n), Xi = variabel keputusan pada tahap i, Si= keadaan pada tahap i, ri (Si,Xi) = keputusan pada tahap i, fi, (Si,Xi)= keputusan optimal dari tahap 1 sampai i, fi−1 (Si−1,Xi−1 )= keputusan optimal dari tahap i sampai 1. Data yang digunakan dalam penelitian ini merupakan data sekunder yang diperoleh dengan cara mengumpulkan data dari Perusahaan. Dengan menggunakan teori Program Dinamik perhitungan mundur maka jumlah jam kerja efektif 573.460 jam dapat dioptimalkan menjadi 468.714,27 jam dengan jumlah tenaga kerja (orang) yang dibutuhkan setiap bulan pada tahun 2011 adalah 152 orang/ bulan. Biaya yang dikeluarkan untuk kebutuhan tenaga kerja sebesar Rp 3.976.509.219 dengan menggunakan program dinamik dapat dioptimalkan menjadi Rp 3.236.431.421,94

    Magneto-optical trapping of bosonic and fermionic neon isotopes and their mixtures: isotope shift of the ^3P_2 to ^3D_3 transition and hyperfine constants of the ^3D_3 state of Ne-21

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    We have magneto-optically trapped all three stable neon isotopes, including the rare Ne-21, and all two-isotope combinations. The atoms are prepared in the metastable ^3P_2 state and manipulated via laser interaction on the ^3P_2 to ^3D_3} transition at 640.2nm. These cold (T = 1mK) and environmentally decoupled atom samples present ideal objects for precision measurements and the investigation of interactions between cold and ultracold metastable atoms. In this work, we present accurate measurements of the isotope shift of the ^3P_2 to ^3D_3 transition and the hyperfine interaction constants of the ^3D_3 state of Ne-21. The determined isotope shifts are (1625.9\pm0.15)MHz for Ne-20 to Ne-22, (855.7\pm1.0)MHz for Ne-20 to Ne-21, and (770.3\pm1.0)MHz for Ne-21 to Ne-22. The obtained magnetic dipole and electric quadrupole hyperfine interaction constants are A(^3D_3)= (-142.4\pm0.2)MHz and B(^3D_3)=(-107.7\pm1.1)MHz, respectively. All measurements give a reduction of uncertainty by about one order of magnitude over previous measurements

    Experimental (n,γ\gamma) cross sections of the p-process nuclei 74^{74}Se and 84^{84}Sr

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    The nucleosynthesis of elements beyond iron is dominated by the s and r processes. However, a small amount of stable isotopes on the proton-rich side cannot be made by neutron capture and are thought to be produced by photodisintegration reactions on existing seed nuclei in the so-called "p process". So far most of the p-process reactions are not yet accessible by experimental techniques and have to be inferred from statistical Hauser-Feshbach model calculations. The parametrization of these models has to be constrained by measurements on stable proton-rich nuclei. A series of (n,γ\gamma) activation measurements, related by detailed balance to the respective photodisintegrations, were carried out at the Karlsruhe Van de Graaff accelerator using the 7^7Li(p,n)7^7Be source for simulating a Maxwellian neutron distribution of kT= 25 keV. First results for the experimental (n,γ\gamma) cross sections of the light p nuclei 74^{74}Se and 84^{84}Sr are reported. These experimental values were used for an extrapolation to the Maxwellian averaged cross section at 30 keV, 30_{30}, yielding 271±\pm15 mb for 74^{74}Se, and 300±\pm17 mb for the total capture cross section of 84^{84}Sr. The partial cross section to the isomer in 85^{85}Sr was found to be 190±\pm10 mb.Comment: 10 pages, 5 figure

    On the alpha activity of natural tungsten isotopes

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    The indication for the alpha decay of 180-W with a half-life T1/2=1.1+0.8-0.4(stat)+-0.3(syst)x10^18 yr has been observed for the first time with the help of the super-low background 116-CdWO_4 crystal scintillators. In conservative approach the lower limit on half-life of 180-W has been established as T1/2>0.7x10^18 yr at 90% C.L. Besides, new T1/2 bounds were set for alpha decay of 182-W, 183-W, 184-W and 186-W at the level of 10^20 yr.Comment: 16 pages, 8 figures, accepted in Phys. Rev.

    Performance Scores in General Practice: A Comparison between the Clinical versus Medication-Based Approach to Identify Target Populations

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    CONTEXT: From one country to another, the pay-for-performance mechanisms differ on one significant point: the identification of target populations, that is, populations which serve as a basis for calculating the indicators. The aim of this study was to compare clinical versus medication-based identification of populations of patients with diabetes and hypertension over the age of 50 (for men) or 60 (for women), and any consequences this may have on the calculation of P4P indicators. METHODS: A comparative, retrospective, observational study was carried out with clinical and prescription data from a panel of general practitioners (GPs), the Observatory of General Medicine (OMG) for the year 2007. Two indicators regarding the prescription for statins and aspirin in these populations were calculated. RESULTS: We analyzed data from 21.690 patients collected by 61 GPs via electronic medical files. Following the clinical-based approach, 2.278 patients were diabetic, 8,271 had hypertension and 1.539 had both against respectively 1.730, 8.511 and 1.304 following the medication-based approach (% agreement = 96%, kappa = 0.69). The main reasons for these differences were: forgetting to code the morbidities in the clinical approach, not taking into account the population of patients who were given life style and diet rules only or taking into account patients for whom morbidities other than hypertension could justify the use of antihypertensive drugs in the medication-based approach. The mean (confidence interval) per doctor was 33.7% (31.5-35.9) for statin indicator and 38.4% (35.4-41.4) for aspirin indicator when the target populations were identified on the basis of clinical criteria whereas they were 37.9% (36.3-39.4) and 43.8% (41.4-46.3) on the basis of treatment criteria. CONCLUSION: The two approaches yield very "similar" scores but these scores cover different realities and offer food for thought on the possible usage of these indicators in the framework of P4P programmes

    The Fine-structure Constant as a Probe of Chemical Evolution and AGB Nucleosynthesis in Damped Lyman-alpha Systems

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    Evidence from a large sample of quasar absorption-line spectra in damped Lyman-alpha systems has suggested a possible time variation of the fine structure constant alpha. The most statistically significant portion of this sample involves the comparison of Mg and Fe wavelength shifts using the many-multiplet (MM) method. However, the sensitivity of this method to the abundance of heavy isotopes, especially Mg, is enough to imitate an apparent variation in alpha in the redshift range 0.5 < z < 1.8. We implement recent yields of intermediate mass (IM) stars into a chemical evolution model and show that the ensuing isotope distribution of Mg can account for the observed variation in alpha provided the early IMF was particularly rich in intermediate mass stars (or the heavy Mg isotope yields from AGB stars are even higher than in present-day models). As such, these observations of quasar absorption spectra can be used to probe the nucleosynthetic history of low-metallicity damped Lyman-alpha systems in the redshift range 0.5 < z < 1.8. This analysis, in conjunction with other abundance measurements of low-metallicity systems, reinforces the mounting evidence that star formation at low metallicities may have been strongly influenced by a population of IM stars. Such IM stars have a significant influence on other abundances, particularly nitrogen. We constrain our models with independent measurements of N, Si, and Fe in damped Lyman-alpha systems as well as C/O in low-metallicity stars. In this way, we obtain consistent model parameters for this chemical-evolution interpretation of the MM method results.Comment: 38 pages, latex, 25 ps figures, as accepted in Ap

    Symbol Emergence in Cognitive Developmental Systems: a Survey

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    OAPA Humans use signs, e.g., sentences in a spoken language, for communication and thought. Hence, symbol systems like language are crucial for our communication with other agents and adaptation to our real-world environment. The symbol systems we use in our human society adaptively and dynamically change over time. In the context of artificial intelligence (AI) and cognitive systems, the symbol grounding problem has been regarded as one of the central problems related to symbols. However, the symbol grounding problem was originally posed to connect symbolic AI and sensorimotor information and did not consider many interdisciplinary phenomena in human communication and dynamic symbol systems in our society, which semiotics considered. In this paper, we focus on the symbol emergence problem, addressing not only cognitive dynamics but also the dynamics of symbol systems in society, rather than the symbol grounding problem. We first introduce the notion of a symbol in semiotics from the humanities, to leave the very narrow idea of symbols in symbolic AI. Furthermore, over the years, it became more and more clear that symbol emergence has to be regarded as a multifaceted problem. Therefore, secondly, we review the history of the symbol emergence problem in different fields, including both biological and artificial systems, showing their mutual relations. We summarize the discussion and provide an integrative viewpoint and comprehensive overview of symbol emergence in cognitive systems. Additionally, we describe the challenges facing the creation of cognitive systems that can be part of symbol emergence systems

    Identifying the needs for a web-based postpartum platform among parents of newborns and health care professionals: qualitative focus group study

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    Background: During the turbulent postpartum period, there is an urgent need by parents for support and information regarding the care for their infant. In the Netherlands, professional support is provided during the first 8 days postpartum and for a maximum of 8 hours a day. This care is delivered by maternity care assistants (MCAs). Despite the availability of this extensive care, a majority of women prefer to make use of a lesser amount of postpartum care. After this period, access to care is less obvious. Where parents are automatically offered care in the first 8 days after birth, they must request care in the period thereafter. To compensate for a possible gap in information transfer, electronic health (eHealth) can be a valuable, easily accessible addition to regular care. Objective: We explored the needs and preferred
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