164 research outputs found

    Cauchy's infinitesimals, his sum theorem, and foundational paradigms

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    Cauchy's sum theorem is a prototype of what is today a basic result on the convergence of a series of functions in undergraduate analysis. We seek to interpret Cauchy's proof, and discuss the related epistemological questions involved in comparing distinct interpretive paradigms. Cauchy's proof is often interpreted in the modern framework of a Weierstrassian paradigm. We analyze Cauchy's proof closely and show that it finds closer proxies in a different modern framework. Keywords: Cauchy's infinitesimal; sum theorem; quantifier alternation; uniform convergence; foundational paradigms.Comment: 42 pages; to appear in Foundations of Scienc

    ЧУТЛИВІСТЬ МІКРООРГАНІЗМІВ, ВИДІЛЕНИХ З ПАТОЛОГІЧНОГО МАТЕРІАЛУ, ДО АНТИМІКРОБНИХ ПРЕПАРАТІВ

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    Excessive and uncontrolled use of antibiotics commonly results in the emergence of antimicrobial resistance (AMR). Therefore, the main aim of these studies was to determine the antibiotic susceptibility of microorganisms isolated from the pathological material. The article describes the susceptibility of isolated strains to the following antibiotics: ampicillin, amoxicillin, oxacillin, ofloxacin, streptomycin, cefazolin, gentamicin, amikacin, amoxiclav, erythromycin, enrofloxacin, lincomycin, tetracycline, doxycycline, vancomycin, rifampicin, ciprofloxacin, norfloxacin, tylosin, nitrofurantoin, polymyxin B. During the study of six Escherichia coli and three Salmonella enteritidis strains, it was ascertained that they demonstrated different susceptibility to the studied antibiotics, in particular, only two E. coli isolates, which is 33,3 %, were resistant to streptomycin, 50 % of the isolated strains were susceptible. When determining the susceptibility, it was established that all isolated E. coli isolates were resistant to cefazolin, vancomycin, oxacillin, and 83,3 % were resistant to amoxicillin, ampicillin, vancomycin, amoxiclav, rifampicin. 33,3 % of Salmonella enteritidis isolates were moderately susceptible to streptomycin, amoxicillin, and ampicillin, and 66,7 % were sensitive to ciprofloxacin, norfloxacin, and enrofloxacin. All isolated S. enteritidis strains were found to be resistant to cefazolin, tylosin, vancomycin, oxacillin, lincomycin, and erythromycin, 100 % susceptible to ciprofloxacin, amikacin, and ofloxacin and 68,7 % moderately susceptible to amoxicillin and gentamicin.Надмірне та безконтрольне використання антибіотиків часто приводить до виникнення антибіотикорезистентності. Тому основна мета цих досліджень полягала у визначенні чутливості до антибіотиків мікроорганізмів, виділених з патматеріалу. У статті наведене визначення чутливості виділених штамів до таких антибіотиків: ампіциліну, амоксициліну, оксациліну, офлоксацину, стрептоміцину, цефазоліну, гентаміцину, амікацину, амоксиклаву, еритроміцину, енрофлоксацину, лінкоміцину, тетрацикліну, доксицикліну, ванкоміцину, рифампіцину, ципрофлоксацину, норфлоксацину, тилозину, нітрофурантоїну, поліміксину В. При дослідженні шести щтамів ‒ Esсherichia coli та трьох Salmonella enteritidis, встановлено, що вони проявляли різну чутливість до досліджуваних антибіотиків, зокрема резистентними до стрептоміцину виявились лише два ізоляти E. coli, що складає 33,3 %, чутливими було 50 % виділених штамів. При визначенні чутливості встановлено, що всі виділені ізоляти E. coli були стійкими до цефазоліну, ванкоміцину, оксациліну, а 83,3 % стійкими до амоксациліну, ампіциліну, ванкоміцину, амоксиклаву, рифампіцину. 33,3 % виділених ізолятів S. enteritidis були помірно-чутливими до стрептоміцину, амоксациліну, ампіциліну, а 66,7 % ‒ чутливими до ципрофлоксацину, норфлоксацину та енрофлоксацину. Встановлено, що всі виділені штами S. enteritidis були стійкими до цефазоліну, тилозину, ванкоміцину, оксациліну, лінкоміцину та еритроміцину, 100 % чутливими до ципрофлоксацину, амікацину та офлоксацину та 68,7 % помірно-чутливими до амоксациліну та гентаміцину

    Physics of B_c mesons

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    In the framework of potential models for heavy quarkonium the mass spectrum for the system (bˉc\bar b c) is considered. Spin-dependent splittings, taking into account a change of a constant for effective coulomb interaction between the quarks, and widths of radiative transitions between the (bˉc\bar b c) levels are calculated. In the framework of QCD sum rules, masses of the lightest vector BcB_c^* and pseudoscalar BcB_c states are estimated, scaling relation for leptonic constants of heavy quarkonia is derived, and the leptonic constant fBcf_{B_c} is evaluated. The BcB_c decays are considered in the framework of both the potential models and the QCD sum rules, where the significance of Coulomb-like corrections is shown. The relations, following from the approximate spin symmetry for the heavy quarks in the heavy quarkonium, are analysed for the form factors of the semileptonic weak exclusive decays of BcB_c. The BcB_c lifetime is evaluated with the account of the corrections to the spectator mechanism of the decay, because of the quark binding into the meson. The total and differential cross sections of the BcB_c production in different interactions are calculated. The analytic expressions for the fragmentational production cross sections of BcB_c are derived. The possibility of the practical BcB_c search in the current and future experiments at electron-positron and hadron colliders is analysed.Comment: 81 page, latex, ihep.sty is required and attached in the end of the file after \end{document}, figures are not availabl

    Attacks based on malicious perturbations on image processing systems and defense methods against them

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    Systems implementing artificial intelligence technologies have become widespread due to their effectiveness in solving various applied tasks including computer vision. Image processing through neural networks is also used in securitycritical systems. At the same time, the use of artificial intelligence is associated with characteristic threats including disruption of machine learning models. The phenomenon of triggering an incorrect neural network response by introducing perturbations that are visually imperceptible to a person was first described and attracted the attention of researchers in 2013. Methods of attacks on neural networks based on malicious perturbations have been continuously improved, ways of disrupting the operation of neural networks in processing various types of data and tasks of the target model have been proposed. The threat of disrupting the functioning of neural networks through these attacks has become a significant problem for systems implementing artificial intelligence technologies. Thus, research in the field of countering attacks based on malicious perturbations is very relevant. This article describes current attacks, provides an overview and comparative analysis of such attacks on image processing systems based on artificial intelligence. Approaches to the classification of attacks based on malicious perturbations are formulated. Defense methods against such attacks are considered, their shortcomings are revealed. The limitations of the applied defense methods that reduce the effectiveness of counteraction to attacks are shown. Approaches and practical measures to detect and eliminate harmful disturbances are proposed

    Low-Temperature Polymorphic Phase Transition in a Crystalline Tripeptide L-Ala-L-Pro-Gly·H2O Revealed by Adiabatic Calorimetry

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    We demonstrate application of precise adiabatic vacuum calorimetry to observation of phase transition in the tripeptide l-alanyl-l-prolyl-glycine monohydrate (APG) from 6 to 320 K and report the standard thermodynamic properties of the tripeptide in the entire range. Thus, the heat capacity of APG was measured by adiabatic vacuum calorimetry in the above temperature range. The tripeptide exhibits a reversible first-order solid-to-solid phase transition characterized by strong thermal hysteresis. We report the standard thermodynamic characteristics of this transition and show that differential scanning calorimetry can reliably characterize the observed phase transition with <5 mg of the sample. Additionally, the standard entropy of formation from the elemental substances and the standard entropy of hypothetical reaction of synthesis from the amino acids at 298.15 K were calculated for the studied tripeptide.National Institute of Biomedical Imaging and Bioengineering (U.S.) (EB-003151)National Institute of Biomedical Imaging and Bioengineering (U.S.) (EB-001960)National Institute of Biomedical Imaging and Bioengineering (U.S.) (EB-002026

    Corrigendum to "European contribution to the study of ROS:A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)" [Redox Biol. 13 (2017) 94-162]

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    The European Cooperation in Science and Technology (COST) provides an ideal framework to establish multi-disciplinary research networks. COST Action BM1203 (EU-ROS) represents a consortium of researchers from different disciplines who are dedicated to providing new insights and tools for better understanding redox biology and medicine and, in the long run, to finding new therapeutic strategies to target dysregulated redox processes in various diseases. This report highlights the major achievements of EU-ROS as well as research updates and new perspectives arising from its members. The EU-ROS consortium comprised more than 140 active members who worked together for four years on the topics briefly described below. The formation of reactive oxygen and nitrogen species (RONS) is an established hallmark of our aerobic environment and metabolism but RONS also act as messengers via redox regulation of essential cellular processes. The fact that many diseases have been found to be associated with oxidative stress established the theory of oxidative stress as a trigger of diseases that can be corrected by antioxidant therapy. However, while experimental studies support this thesis, clinical studies still generate controversial results, due to complex pathophysiology of oxidative stress in humans. For future improvement of antioxidant therapy and better understanding of redox-associated disease progression detailed knowledge on the sources and targets of RONS formation and discrimination of their detrimental or beneficial roles is required. In order to advance this important area of biology and medicine, highly synergistic approaches combining a variety of diverse and contrasting disciplines are needed

    Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

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    Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a ZZ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 <pT<100< p_{\textrm{T}} < 100 GeV and in the pseudorapidity range 2.5<η<42.5 < \eta < 4. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb1^{-1}. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

    Study of the BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

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    The decay BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} is studied in proton-proton collisions at a center-of-mass energy of s=13\sqrt{s}=13 TeV using data corresponding to an integrated luminosity of 5 fb1\mathrm{fb}^{-1} collected by the LHCb experiment. In the Λc+K\Lambda_{c}^+ K^{-} system, the Ξc(2930)0\Xi_{c}(2930)^{0} state observed at the BaBar and Belle experiments is resolved into two narrower states, Ξc(2923)0\Xi_{c}(2923)^{0} and Ξc(2939)0\Xi_{c}(2939)^{0}, whose masses and widths are measured to be m(Ξc(2923)0)=2924.5±0.4±1.1MeV,m(Ξc(2939)0)=2938.5±0.9±2.3MeV,Γ(Ξc(2923)0)=0004.8±0.9±1.5MeV,Γ(Ξc(2939)0)=0011.0±1.9±7.5MeV, m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV}, where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt Λc+K\Lambda_{c}^{+} K^{-} sample. Evidence of a new Ξc(2880)0\Xi_{c}(2880)^{0} state is found with a local significance of 3.8σ3.8\,\sigma, whose mass and width are measured to be 2881.8±3.1±8.5MeV2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV} and 12.4±5.3±5.8MeV12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}, respectively. In addition, evidence of a new decay mode Ξc(2790)0Λc+K\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-} is found with a significance of 3.7σ3.7\,\sigma. The relative branching fraction of BΛc+ΛˉcKB^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} with respect to the BD+DKB^{-} \to D^{+} D^{-} K^{-} decay is measured to be 2.36±0.11±0.22±0.252.36 \pm 0.11 \pm 0.22 \pm 0.25, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages
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