Symplectic bifurcation theory for integrable systems

This paper develops a symplectic bifurcation theory for integrable systems in dimension four. We prove that if an integrable system has no hyperbolic singularities and its bifurcation diagram has no vertical tangencies, then the fibers of the induced singular Lagrangian fibration are connected. The image of this singular Lagrangian fibration is, up to smooth deformations, a planar region bounded by the graphs of two continuous functions. The bifurcation diagram consists of the boundary points in this image plus a countable collection of rank zero singularities, which are contained in the interior of the image. Because it recently has become clear to the mathematics and mathematical physics communities that the bifurcation diagram of an integrable system provides the best framework to study symplectic invariants, this paper provides a setting for studying quantization questions, and spectral theory of quantum integrable systems.Comment: 42 pages, 19 figure

Accurate Phase Calibration for Digital Beam-Forming in Multi-Transceiver HF Radar System

The TIGER-3 radar is being developed as an “all digital” radar with 20 integrated digital transceivers, each connected to a separate antenna. Using phased array antenna techniques, radiated power is steered towards a desired direction based on the relative phases within the array elements. This paper proposes an accurate phase measurement method to calibrate the phases of the radio output signals using Field Programmable Gate Array (FPGA) technology. The method sequentially measures the phase offset between the RF signal generated by each transceiver and a reference signal operated at the same frequency. Accordingly, the transceiver adjusts its phase in order to align to the reference phase. This results in accurately aligned phases of the RF output signals and with the further addition of appropriate phase offsets, digital beamforming (DBF) can be performed steering the beam in a desired direction. The proposed method is implemented on a Virtex-5 VFX70T device. Experimental results show that the calibration accuracy is of 0.153 degrees with 14 MHz operating frequency

Synthesize and characterization of artificial human bone developed by using nanocomposite

The combination of biopolymers with bioceramics plays vital role in development of artificial bone. Hydroxyapatite is extensively used as a material in prosthetic bone repair and replacement. In this paper synthesis of Hydroxyapatite- Polymethyl methacrylate – Zirconia (Hap-PMMA-ZrO2) composite by using powder metallurgy technique. The mechanical, morphological, In-vitro biocompatibility and tribological properties were characterized by universal testing machine, micro-vickers hardness tester, high resolution transmission electron microscope (HR-TEM), MTT assay and pin-on-disc setup. In-vitro cytotoxicity test on HeLa cell lines shows cell viability constant when doses concentration increases so material found non-toxic. Results show that micro Vickers hardness i.e. 520 approximately matches with natural human bone i.e. 400. Compressive strength is less as compared to human bone because of powder metallurgy route used for fabrication and is 74 MPa. Density of proposed composite artificial human bone i.e. 1.52 g/cc is less as compared to natural bone i.e. 2.90 g/cc. The Hap-PMMA-ZrO2 composite will be good biomaterials for bone repair and replacement wor

Rise in alanine aminotransferase after HCV treatment is a highly sensitive screen for treatment failure

Nucleic acid testing to confirm sustained virological response (SVR) after HCV therapy is technical, often expensive, and frequently unavailable where disease prevalence is highest. Alternative surrogate biomarkers merit evaluation. In a short-treatment trial in Vietnam (SEARCH-1; n = 52) we analysed how changes in alanine transaminase (ΔALT) and aspartate transaminase (ΔAST), from end of treatment (EOT) to EOT + 12 weeks, related to SVR, defined as HCV RNA 0 IU/L was 98.1% (89.9 - 99.9%) sensitive and 35.8% (27.3 - 45.1%) specific. A rise in ALT or AST after HCV therapy is a highly sensitive screen for treatment failure in mild liver disease. This finding could reduce costs and complexity of managing HCV

L^{2}-restriction bounds for eigenfunctions along curves in the quantum completely integrable case

We show that for a quantum completely integrable system in two dimensions,the $L^{2}$-normalized joint eigenfunctions of the commuting semiclassical pseudodifferential operators satisfy restriction bounds ofthe form $\int_{\gamma} |\phi_{j}^{\hbar}|^2 ds = {\mathcal O}(|\log \hbar|)$ for generic curves $\gamma$ on the surface. We also prove that the maximal restriction bounds of Burq-Gerard-Tzvetkov are always attained for certain exceptional subsequences of eigenfunctions.Comment: Correct some typos and added some more detail in section

Cathelicidin suppresses lipid accumulation and hepatic steatosis by inhibition of the CD36 receptor.

Background and objectivesObesity is a global epidemic which increases the risk of the metabolic syndrome. Cathelicidin (LL-37 and mCRAMP) is an antimicrobial peptide with an unknown role in obesity. We hypothesize that cathelicidin expression correlates with obesity and modulates fat mass and hepatic steatosis.Materials and methodsMale C57BL/6 J mice were fed a high-fat diet. Streptozotocin was injected into mice to induce diabetes. Experimental groups were injected with cathelicidin and CD36 overexpressing lentiviruses. Human mesenteric fat adipocytes, mouse 3T3-L1 differentiated adipocytes and human HepG2 hepatocytes were used in the in vitro experiments. Cathelicidin levels in non-diabetic, prediabetic and type II diabetic patients were measured by enzyme-linked immunosorbent assay.ResultsLentiviral cathelicidin overexpression reduced hepatic steatosis and decreased the fat mass of high-fat diet-treated diabetic mice. Cathelicidin overexpression reduced mesenteric fat and hepatic fatty acid translocase (CD36) expression that was reversed by lentiviral CD36 overexpression. Exposure of adipocytes and hepatocytes to cathelicidin significantly inhibited CD36 expression and reduced lipid accumulation. Serum cathelicidin protein levels were significantly increased in non-diabetic and prediabetic patients with obesity, compared with non-diabetic patients with normal body mass index (BMI) values. Prediabetic patients had lower serum cathelicidin protein levels than non-diabetic subjects.ConclusionsCathelicidin inhibits the CD36 fat receptor and lipid accumulation in adipocytes and hepatocytes, leading to a reduction of fat mass and hepatic steatosis in vivo. Circulating cathelicidin levels are associated with increased BMI. Our results demonstrate that cathelicidin modulates the development of obesity

Vanishing Twist near Focus-Focus Points

We show that near a focus-focus point in a Liouville integrable Hamiltonian system with two degrees of freedom lines of locally constant rotation number in the image of the energy-momentum map are spirals determined by the eigenvalue of the equilibrium. From this representation of the rotation number we derive that the twist condition for the isoenergetic KAM condition vanishes on a curve in the image of the energy-momentum map that is transversal to the line of constant energy. In contrast to this we also show that the frequency map is non-degenerate for every point in a neighborhood of a focus-focus point.Comment: 13 page

Generalizability assessment of AI models across hospitals in a low-middle and high income country

The integration of artificial intelligence (AI) into healthcare systems within low-middle income countries (LMICs) has emerged as a central focus for various initiatives aiming to improve healthcare access and delivery quality. In contrast to high-income countries (HICs), which often possess the resources and infrastructure to adopt innovative healthcare technologies, LMICs confront resource limitations such as insufficient funding, outdated infrastructure, limited digital data, and a shortage of technical expertise. Consequently, many algorithms initially trained on data from non-LMIC settings are now being employed in LMIC contexts. However, the effectiveness of these systems in LMICs can be compromised when the unique local contexts and requirements are not adequately considered. In this study, we evaluate the feasibility of utilizing models developed in the United Kingdom (a HIC) within hospitals in Vietnam (a LMIC). Consequently, we present and discuss practical methodologies aimed at improving model performance, emphasizing the critical importance of tailoring solutions to the distinct healthcare systems found in LMICs. Our findings emphasize the necessity for collaborative initiatives and solutions that are sensitive to the local context in order to effectively tackle the healthcare challenges that are unique to these regions

ОПРЕДЕЛЕНИЕ ВИДОВОГО СОСТАВА АНТОЦИАНОВ ЦВЕТКОВ Сatharanthus

Using the reversed phase high performance liquid chromatography with diode-array and mass-spectrometric (in ESI mode) detection, a composition of Catharanthus roseum petals was established. After the acid hydrolysis, all five anthocyanidins were found to be different comparing to the ordinary anthocyanidins from Vitis vinifera fruits. The anthocyanins were elucidated to be 7-O-methyl derivatives of delphinidin, cyanidin, petunidin, peonidin and malvidin by the analysis of retention in RP HPLC, mass- and UV-visible spectra. The anthocyanins were characterized with UV-visible spectra, having the same fixtures as the set of non-methylated (in position 7) anthocyanin with hypsochromic (4 nm) of spectral maxima. The absorption bands for 7-methlcyanidin and 7-methylpeonidin aglycons and derivatives were indistinguishable while for the set of 7-methydelphinidin, 7-methypetunidin and 7-methylnalvidin (hirsutidin) a consecutive shift of absorption maxima by approximately 1 – 1.5 nm was found. The same was true for non-methylates at position 7 derivatives. The analysis of retention of anthocyanins of the flowers including the comparison with the retention of Mangifera indica skin anthocyanins, mass- and UV-visible spectra indicated that a minor set of anthocyanins included two sets of derivatives. The minor compounds were found to be 3-galactosides for samples under investigation, while the set of the major anthocyanins was represented by 3-rhamnosilgalactosides. Indeed, though through mass-spectra it was not possible to differentiate 3-rhamnosylgalatosides and 3-(p-coumaroylgalactosides) because of m/z coincidence, the retention difference between the two found anthocyanins sets as well as UV-visible spectra excluded the latter type of derivatives.Key words: anthocyanins, HPLC, 7-O-methyl derivatives of delphinidin, cyanidin, petunidin, peonidin and malvidin, 3-galactosides, 3-phamnosylgalactosides, UV-vis spectra, mass-spectrometric detection.(Russian)DOI: http://dx.doi.org/10.15826/analitika.2019.23.1.001V.I. Deineka1, Y.Y. Kulchenko1, А.N. Sidorov1, I.P. Blinova1, S.М. Varushkina1, L.А. Deineka1, Anh Thi Ngoc Vu2 1Belgorod National Research University, Pobeda str., 85, Belgorod, 308015,Russian Federation2 RUDN University, Miklukho-Maklaya str. 6, Moscow, 117198, Russian FederationС использованием обращенно-фазовой высокоэффективной жидкостной хроматографии с диодно-матричным и масс-спектрометрическим детектированием исследован видовой состав антоцианов цветков Catharanthus roseum. После кислотного гидролиза антоцианов по характерному изменению электронных спектров поглощения и по изменению удерживания было установлено, что все пять антоцианидинов цветков фиолетового цвета отличаются от пяти наиболее часто встречающихся в природе (в виде гликозидов) антоцианидинов однотипным дополнительным метилированием. Направление метилирования по гидроксильной группе в положении 7 флавилиевого скелета было определено при анализе изменения параметров электронных спектров поглощения; таким образом, антоцианы цветков катарантуса построены на пяти необычных антоцианидинах, – являясь производными 7-метилдельфинидина, 7-метилцианидина, 7-метилпетунидина, 7 метилпеонидина (розинидина) и 7 метилмальвидина (хирсутидина). Сопоставление масс-спектрометрических данных, электронных спектров поглощения и параметров удерживания антоцианов цветков Catharanthus roseum указывают на присутствие в экстрактах лепестках цветков 3-рамозилгалактозидов указанных антоцианидинов, к которым добавляются (в меньшем количестве) 3-галактозиды.Ключевые слова: антоцианы, 7-метилированные антоцианы, обращенно-фазовая ВЭЖХDOI: http://dx.doi.org/10.15826/analitika.2019.23.1.00

The impact of albendazole treatment on the incidence of viral- and bacterial-induced diarrhea in school children in southern Vietnam: study protocol for a randomized controlled trial

Anthelmintics are one of the more commonly available classes of drugs to treat infections by parasitic helminths (especially nematodes) in the human intestinal tract. As a result of their cost-effectiveness, mass school-based deworming programs are becoming routine practice in developing countries. However, experimental and clinical evidence suggests that anthelmintic treatments may increase susceptibility to other gastrointestinal infections caused by bacteria, viruses, or protozoa. Hypothesizing that anthelmintics may increase diarrheal infections in treated children, we aim to evaluate the impact of anthelmintics on the incidence of diarrheal disease caused by viral and bacterial pathogens in school children in southern Vietnam.This is a randomized, double-blinded, placebo-controlled trial to investigate the effects of albendazole treatment versus placebo on the incidence of viral- and bacterial-induced diarrhea in 350 helminth-infected and 350 helminth-uninfected Vietnamese school children aged 6-15 years. Four hundred milligrams of albendazole, or placebo treatment will be administered once every 3 months for 12 months. At the end of 12 months, all participants will receive albendazole treatment. The primary endpoint of this study is the incidence of diarrheal disease assessed by 12 months of weekly active and passive case surveillance. Secondary endpoints include the prevalence and intensities of helminth, viral, and bacterial infections, alterations in host immunity and the gut microbiota with helminth and pathogen clearance, changes in mean z scores of body weight indices over time, and the number and severity of adverse events.In order to reduce helminth burdens, anthelmintics are being routinely administered to children in developing countries. However, the effects of anthelmintic treatment on susceptibility to other diseases, including diarrheal pathogens, remain unknown. It is important to monitor for unintended consequences of drug treatments in co-infected populations. In this trial, we will examine how anthelmintic treatment impacts host susceptibility to diarrheal infections, with the aim of informing deworming programs of any indirect effects of mass anthelmintic administrations on co-infecting enteric pathogens.ClinicalTrials.gov: NCT02597556 . Registered on 3 November 2015