130 research outputs found

    A Q-Learning-Based Approach for Simple and Multi-Agent Systems

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    This study proposes different machine learning-based solutions to both single and multi-agent systems, took place on a 2-D simulation platform, namely, Robocode. This dynamic and programmable platform allows agents to interact with the environment and each other by employing a variety of battling strategies. Q-Learning is one of the leading and popular machine learning-based solutions to be applied to such a problem. However, especially for continued spaces, the control problem gets deeper. Essentially, one of the main drawbacks of reinforcement learning (RL) is to design an appropriate reward function that the function can be described by only employing few parameters for simple tasks, whereas estimating the goal of the reward function may be a challenging problem. Recent studies prove that neural network-based approaches can handle these challenges and achieve to learn control strategies from 2-D or 1-D data. Besides those problems of RL algorithms for single robots, once the number of robots increases and the systems need to behave as multi-agent systems, the overall design requirements become more complex. Accordingly, the proposed system is validated by considering different battle scenarios. The performance of the Q-Learning-based system and the supervised learning techniques are compared by employing different scenarios for this problem. Results reveal the superiority of the ANN-based approach over other methods

    Ocular morbidities of premature children with mild or no retinopathy of prematurity

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    SUMMARY: Küçükevcilioğlu M, Mutlu FM, Sarıcı SÜ. Ocular morbidities of premature children with mild or no retinopathy of prematurity. Turk J Pediatr 2015; 57: 129-135. This study reports the ocular and neurologic outcomes at 3 years of age of preterm children with mild or no retinopathy of prematurity (ROP). We were able to compile data from the medical records of 119 out of 585 (20.3%) children with mild and no ROP, who were screened between March 1999 and March 2012. There were 52 children with mild ROP and 67 with no ROP. In terms of ROP-related risk factors, the mild ROP and no ROP groups showed significant differences in birth weight (p<0.001) and gestational age (p<0.001), as well as in the presence of mechanical ventilation (p=0.04), respiratory distress syndrome (p=0.003), blood transfusion (p=0.006) and sepsis (p=0.024). However, both groups seemed identical in terms of the distribution of refractive errors, presence of strabismus, presence of unfavorable structural or functional outcome, and presence of neurologic sequelae. In particular, the high incidence of neurologic morbidity (100%) in subjects with very poor vision suggested a clear correlation

    Familial mediterranean fever with neonatal onset: case report

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    Familial Mediterranean fever (FMF) is an autosomal recessively inherited disorder characterized by recurrent fever and attacks of abdominal pain, chest pain, and joint pain. Attacks of recurrent fever and serositis are encountered clinically. Attacks may present either with only one symptom or many simultaneous symptoms. Although most of the patients are diagnosed clinically above the age of 2, those cases who are diagnosed before 2 years of age and with clinical course of isolated fever are believed to have a more serious course and tend to develop amyloidosis. In this article, a case who was admitted first on the 22nd day of life and later diagnosed to have FMF with recurrent attacks of isolated fever and no other focus is presented. We emphasize that FMF may present as early as in the first month of life, and it should be considered in cases presenting with fever of unknown origin and misdiagnosed to have late neonatal sepsis or occult bacteremia at this age group

    Dynamic nuclear polarization of spherical nanoparticles

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Spherical silica nanoparticles of various particle sizes (∼10 to 100 nm), produced by a modified Stoeber method employing amino acids as catalysts, are investigated using Dynamic Nuclear Polarization (DNP) enhanced Nuclear Magnetic Resonance (NMR) spectroscopy. This study includes ultra-sensitive detection of surface-bound amino acids and their supramolecular organization in trace amounts, exploiting the increase in NMR sensitivity of up to three orders of magnitude via DNP. Moreover, the nature of the silicon nuclei on the surface and the bulk silicon nuclei in the core (sub-surface) is characterized at atomic resolution. Thereby, we obtain unique insights into the surface chemistry of these nanoparticles, which might result in improving their rational design as required for promising applications, e.g. as catalysts or imaging contrast agents. The non-covalent binding of amino acids to surfaces was determined which shows that the amino acids not just function as catalysts but become incorporated into the nanoparticles during the formation process. As a result only three distinct Q-types of silica signals were observed from surface and core regions. We observed dramatic changes of DNP enhancements as a function of particle size, and very small particles (which suit in vivo applications better) were hyperpolarized with the best efficiency. Nearly one order of magnitude larger DNP enhancement was observed for nanoparticles with 13 nm size compared to particles with 100 nm size. We determined an approximate DNP penetration-depth (∼4.2 or ∼5.7 nm) for the polarization transfer from electrons to the nuclei of the spherical nanoparticles. Faster DNP polarization buildup was observed for larger nanoparticles. Efficient hyperpolarization of such nanoparticles, as achieved in this work, can be utilized in applications such as magnetic resonance imaging (MRI).DFG, GRK 1524, Self-Assembled Soft-Matter Nanostructures at Interface

    Hyperbilirubinemia due to minor blood group (anti-E) incompatibility in a newborn: A case report

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    In addition to Rh and ABO incompatibilities subgroup incompatibilities may rarely play a role among the causes of hemolytic anemia and indirect hyperbilirubinemia in newborns. The most common minor blood group antigens that cause blood incompatibility between the mother and baby are C, c, E, e, Kell, Duffy, Diego, Kidd and MNSs antigens. In this article, a newborn in whom hyperbilirubinemia due to anti-E minor blood group incompatibility developed and was treated with phototherapy succesfully is presented and minor blood group incompatibilities due to anti-E are reviewed

    Reinvestigating the Environmental Kuznets Curve (EKC) hypothesis by a composite model constructed on the Armey curve hypothesis with government spending for the US States

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    This study reinvestigates the EKC hypothesis for US states with a new methodology that differs from all previous empirical studies using traditional EKC models. To this aim, this methodology, for the first time, unifies two seemingly different but strongly interrelated hypotheses (models), namely the Armey curve (AC) and traditional EKC models, into one single composite model. The rationale for creating this composite model is twofold. First, the functional propositions of these two hypotheses are depicted with inverted U-shaped curves. Second, they also have economically interrelated-causal relationships. This means that rising government spending (through the AC hypothesis) increases real GDP per capita (RGDPPC) and, consequently, increases in RGDPPC (through the EKC hypothesis) increase CO2 emissions. The composite model created may also allow US state policymakers to determine a single maximum spending level that will maximize or minimize CO2 emissions. Empirical findings indicate that the composite model is capable of testing the EKC hypothesis for 7 US states. Additionally, for 7 US states, maximum spending level was calculated to be around 15% of their RGDPPCs. Hence, with this calculated spending level, policymakers of these states may be able to determine-adjust their golden spending levels so as not to cause environmental degradation and declines in GDP. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature

    Investigation on malondialdehyde, s100b and advanced oxidation protein product levels in significant hyperbilirubinemia and the effect of intensive phototherapy on these parameter

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    Background: The parameters of oxidative stress [advanced oxidation protein products (AOPPs), malondialdehyde (MDA), and S100B] and the effect of intensive phototherapy (PT) on these parameters have not been studied extensively in newborns with significant hyperbilirubinemia (SH). We aimed to measure the levels of MDA, S100B, and AOPPs in newborns with SH, and to compare newborns with healthy control newborns without hyperbilirubinemia on the basis of these parameters of oxidative stress. In addition, we investigated the effect of intensive PT on these parameters during the treatment of SH and report our findings for the first time in the literature. Methods: The study was performed in newborns (n = 62) who underwent intensive PT because of SH. Newborns without jaundice constituted the control group (n = 30). Both groups were compared with respect to demographic characteristics and biochemical (laboratory) parameters including MDA, AOPPs, and S100B. MDA, AOPPs, and S100B were also compared before and after intensive PT in the PT group. In the study group, a correlation analysis of demographic characteristics; MDA, AOPP, and S100B values; and changes occurring in MDA, AOPPs, and S100B values due to the effect of intensive PT was performed. Results: Serum total bilirubin, S100B, and MDA levels in the PT group before performing PT were significantly higher than those in the control group. In newborns receiving PT serum total bilirubin, MDA and AOPP levels decreased significantly after intensive PT. In correlation analysis, a statistically significant negative correlation was found only between the amount of billrubin decrease with PT and AOPP levels after PT in the study group. Conclusion: Whether the significant decrease in MDA levels, which was higher prior to PT, is due to the decrease in serum bilirubin levels or due to the effect of intensive PT itself remains to be determined in further studies. The decrease in AOPP levels after PT implies that intensive PT has protective effects on oxidative stress. Copyright (C) 2014, Taiwan Pediatric Association. Published by Elsevier Taiwan LLC. All rights reserved

    Investigation of the relationship between cord clamping time and risk of hyperbilirubinemia

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    Background: Although the relationship between umbilical cord clamping time and various parameters such as hemoglobin (Hb) levels, iron deficiency, and risk of neonatal jaundice has previously been studied, to the best of our knowleadge there have been no studies investigating the relationship between cord clamping time and the risk of significant hyperbilirubinemia. We aimed to investigate the relationship between the time of umbilical cord clamping and transcutaneous bilirubin (TcB) measurements made on various postnatal hours, Hb and serum total bilirubin (STB) levels measured on postnatal 4th day, and the risk of development of significant hyperbilirubinemia requiring phototherapy treatment. Methods: Eligible newborns were divided into two groups on the basis of the time of cord clamping: those clamped late (60 seconds or more; Group I) and those clamped early (less than 60 seconds; Group II). Groups were compared with respect to the parameters of cord Hb, postnatal TcB measurements at 6th, 48th, 96th and 168th hours, and 96th hour Hb, STB and direct bilirubin levels. Results: TcB levels at the 96th and 168th hour were significantly higher in Group I when compared to Group II (p < 0.001 and p < 0.001, respectively). The 96th hour STB level was significantly higher in Group I when compared to Group II (p < 0.001). The need of phototherapy requirement was higher in Group I when compared to Group II (p=0.001). Increase in cord blood Hb for each 1 gr/dl caused a 3.94-fold increased risk in the requirement of phototherapy treatment. Cord clamping time showed statistically significant positive correlations with both cord blood and 96th hour venous Hb levels, with both 96th hour and 168th hour TcB levels, and with 96th hour STB levels. Conclusions: Newborns whose cords are clamped late should be followed up closely with respect to high postnatal bilirubin levels and other risks associated with significant hyperbilirubinemia requiring phototherapy treatment
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