Discrete Integrable Systems and Geometric Numerical Integration

This thesis deals with discrete integrable systems theory and modified Hamiltonian equations in the field of geometric numerical integration. Modified Hamiltonians are used to show that symplectic schemes for Hamiltonian systems are accurate over long times. However, for nonlinear systems the series defining the modified Hamiltonian equation usually diverges. The first part of the thesis demonstrates that there are nonlinear systems where the modified Hamiltonian has a closed-form expression and hence converges. These systems arise from the theory of discrete integrable systems. Specifically, they arise as reductions of a lattice version of the Korteweg-de Vries (KdV) partial differential equation. We present cases of one and two degrees of freedom symplectic mappings, for which the modified Hamiltonian equations can be computed as a closed form expression using techniques of action-angle variables, separation of variables and finite-gap integration. These modified Hamiltonians are also given as power series in the time step by Yoshida's method based on the Baker-Campbell-Hausdorff series. Another example is a system of an implicit dependence on the time step, which is obtained by dimensional reduction of a lattice version of the modified KdV equation. The second part of the thesis contains a different class of discrete-time system, namely the Boussinesq type, which can be considered as a higher-order counterpart of the KdV type. The development and analysis of this class by means of the B{\"a}cklund transformation, staircase reductions and Dubrovin equations forms one of the major parts of the thesis. First, we present a new derivation of the main equation, which is a nine-point lattice Boussinesq equation, from the B{\"a}cklund transformation for the continuous Boussinesq equation. Second, we focus on periodic reductions of the lattice equation and derive all necessary ingredients of the corresponding finite-dimensional models. Using the corresponding monodromy matrix and applying techniques from Lax pair and $r$-matrix structure analysis to the Boussinesq mappings, we study the dynamics in terms of the so-called Dubrovin equations for the separated variables

Wireless resource virtualization: opportunities, challenges, and solutions

Wireless resource virtualization (WRV) is currently emerging as a key technology to overcome the major challenges facing the mobile network operators (MNOs) such as reducing the capital, minimizing the operating expenses, improving the quality of service, and satisfying the growing demand for mobile services. Achieving such conflicting objectives simultaneously requires a highly efficient utilization of the available resources including the network infrastructure and the reserved spectrum. In this paper, the most dominant WRV frameworks are discussed where different levels of network infrastructure and spectrum resources are shared between multiple MNOs. Moreover, we summarize the major benefits and most pressing business challenges of deploying WRV. We further highlight the technical challenges and requirements for ion and sharing of spectrum resources in next generation networks. In addition, we provide guidelines for implementing comprehensive solutions that are able to and share the spectrum resources in next generation network. The paper also presents an efficient algorithm for base station virtualization in long‐term evolution (LTE) networks to share the wireless resources between MNOs who apply different scheduling polices. The proposed algorithm maintains a high‐level of isolation and offers throughput performance gain. Copyright © 2016 John Wiley & Sons, Ltd. Wireless resource virtualization (WRV) is emerging as a key technology to reduce cost and increase the total network capacity by sharing wireless resources between multiple mobile operators. In this paper, we present the concepts, highlight the benefits, and discuss the technical challenges and requirements for ion and sharing of WRV in next generation networks. Furthermore, an efficient WRV approach for long‐term evolution base stations is proposed and evaluated

RISK FACTORS OF PERIODONTAL DISEASES AMONG YEMENI YOUNG DENTAL PATIENTS

Periodontal diseasesare chronic infectious diseases that lead to the inflammation of specialized tissues that surround and support the teeth. Many risk factors and risk indicators, associated with increased risk of periodontal disease, have been identified. Gender, age, education, tooth brushing habit, smoking, khat chewing and shamaa use were associated with periodontal status in Yemen. Accordingly, the aim of our study is to assess the prevalence and related risk factors for periodontal diseases  among Yemeni young dental patients in the faculty of dentistry Sanaa university.735 subjects (both males and females) and systemic free. Clinical examinations were performed including probing pocket depth, plaque index, gingival index and gingival recession. 110 Patients were less than 20 years and  9.1% healthy, 36.4% gingivitis, 22.7% generalized chronic periodontitis (GCP), 4.5% localized aggressive periodontitis (LAP), 27.3% generalized gingivitis with localized chronic periodontitis (LCP) and 0.0% generalized aggressive periodontitis (GAP). 625 Patients were more than 20 years and less than 29 years and 13.6% healthy, 8.7% gingivitis, 29.1% generalized chronic periodontitis (GCP), 2.7% localized aggressive periodontitis (LAP), 45.6% generalized gingivitis with localized chronic periodontitis (LCP) and 0.2% generalized aggressive periodontitis (GAP).Age, gender, education, tooth brushing habit, smoking, khat chewing and shamaa use habit were significantly (P ≤ 0.05) associated with periodontal status. The study confirmed various socio‑demographic risk factors/indictors associated with increased risk of periodontitis among Yemeni young dental patients. Peer Review History: Received 9 October 2017;   Revised 22 October; Accepted 28 October, Available online 15 November 2017 Academic Editor:  Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:        Reviewer's Comments: Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Dr. Emmanuel O. Olorunsola, Department of Pharmaceutics & Pharmaceutical Technology, University of Uyo, Nigeria, [email protected] Dr. Sabah Hussien El-Ghaiesh , Tanta University, Egypt, [email protected] Similar Articles: ETIOLOGY AND RISK FACTORS OF STOMATITIS AMONG YEMENI DENTURE WEARER

PVLSI (Pioneer Valley Life Sciences Institute) Posters - 2019

PVLSI (Pioneer Valley Life Sciences Institute) Posters - 2019https://scholarlycommons.libraryinfo.bhs.org/research_education/1014/thumbnail.jp

Effects of anthropogenic activities on the heavy metal levels in the clams and sediments in a tropical river

The present study aimed to assess the effects of anthropogenic activities on the heavy metal levels in the Langat River by transplantation of Corbicula javanica. In addition, potential ecological risk indexes (PERI) of heavy metals in the surface sediments of the river were also investigated. The correlation analysis revealed that eight metals (As, Co, Cr, Fe, Mn, Ni, Pb and Zn) in total soft tissue (TST) while five metals (As, Cd, Cr, Fe and Mn) in shell have positively and significantly correlation with respective metal concentration in sediment, indicating the clams is a good biomonitor of the metal levels. Based on clustering patterns, the discharge of dam impoundment, agricultural activities and urban domestic waste were identified as three major contributors of the metals in Pangsun, Semenyih and Dusun Tua, and Kajang, respectively. Various geochemical indexes for a single metal pollutant (geoaccumulation index (I geo), enrichment factors (EF), contamination factor (C f) and ecological risk (Er)) all agreed that Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn are not likely to cause adverse effect to the river ecosystem, but As and Pb could pose a potential ecological risk to the river ecosystem. All indexes (degree of contamination (C d), combined pollution index (CPI) and PERI) showed that overall metal concentrations in the tropical river are still within safe limit. River metal pollution was investigated. Anthropogenic activities were contributors of the metal pollution. Geochemical indexes showed that metals are within the safe limit

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p < 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)

RCIA: A New Ultralightweight RFID Authentication Protocol Using Recursive Hash

RFID is one of the most protuberant systems in the field of ubiquitous computing. Since RFID tags have limited computation capabilities, numerous ultralightweight authentication protocols have been proposed to provide privacy and security. However all the previously proposed ultralightweight mutual authentication protocols have some security apprehensions and are vulnerable to various desynchronization and full disclosure attacks. This paper proposes a new ultralightweight mutual authentication protocol to provide robust confidentiality, integrity, and authentication (RCIA) in a cost effective manner. RCIA introduces a new ultralightweight primitive recursive hash, which efficiently detects the message tempering and also avoids all possible desynchronization attacks. RCIA involves only bitwise operations such as XOR, AND, left rotation, and recursive hash. Performance evaluation illustrates that RCIA requires less resources on tag in terms of on-chip memory, communication cost, and computational operations

Integrated traffic grooming in converged data-optical networks

Optical dense wavelength division multiplexing (DWDM) has yielded unprecedented levels of bandwidth scalability. In order to exploit these gains, new converged multiservice transport setups have been evolved, most notably under the multiprotocol label switching (MPLS) and generalized MPLS (GMPLS) frameworks. These paradigms offer very efficient data-optical integration and enable a host of new service capabilities. As operators deploy these new technologies, the provisioning of "subwavelength" demands over wavelengths has become a crucial requirement, i.e., traffic engineering/grooming. This work addresses data-optical grooming in converged GMPLS networks. Here, novel integrated constraint-based routing algorithms are developed to provision subwavelength demands at both packet-switching and lightpath routing levels. Simulations indicate notable performance gains and resource efficiencies with the proposed schemes

Hardware complexity reduction in universal filtered multicarrier transmitter implementation

The inclusion of machine-type communication in the 5G technology has motivated the research community to explore new derivative waveforms of orthogonal frequency division multiplexing. Filter bank multicarrier, universal filtered multicarrier (UFMC), and generalized frequency division multiplexing techniques are under evaluation with respect to their suitability to 5G requirements. In addition to acceptable spectral performance, investigation on computational complexity reduction while addressing flexibility can help in the selection of suitable waveform among multiple options available for 5G. In this regard, based on analysis of computation involved in UFMC waveform construction, few reduced complexity solution for UFMC transmitter implementations are recently proposed. However, hardware-implementation-related issues have not been discussed in detail. In this paper, we have proposed reduced complexity hardware solutions for all three constituent blocks, i.e., inverse discrete Fourier transform (IDFT), finite impulse response (FIR) filter, and spectrum shifting blocks of a UFMC transmitter. For IDFT part, a reduced complexity IFFT solution using Radix-2 decimation in a time technique is presented, where more than 42% computations can be avoided. It is also shown that how five times less number of multipliers can be used in an FIR filter to simplify filter architecture. Finally, a highly efficient method is presented to compute spectrum shifting coefficients through small sized lookup table