Dynamics of Temporal and Spatial Transmission of Vaccine-derived Poliovirus (VDPV) in the Democratic Republic of Congo from 2018 to 2023 | Chapter 10 | Medical Science: Recent Advances and Applications Vol. 2

Background: Vaccine-derived polioviruses (VDPVs) are rare forms of poliovirus that have evolved genetically from the attenuated virus present in oral polio vaccine (OPV). This process occurs during widespread human-to-human transmission in populations with low immunity, or after prolonged replication in the intestines of immunodeficient individuals following vaccination. The Democratic Republic of Congo (DRC) has been facing outbreaks of VDPV since 2017. These wild poliovirus variants are responsible for poliomyelitis, which is in the process of eradication. The following lines show the evolution of VDPV cases across the country in order to understand their chronological dynamics and seasonal influence.

Aim: The study aims to analyze the temporal and spatial dynamics of vaccine-derived poliovirus (VDPV) transmission in the Democratic Republic of Congo from 2018 to 2023.

Methods: A cross-sectional study was conducted on VDPV and reported in the DRC from 2018 to 2023. Maps of the spatial dynamics of VDPV cases were produced from attack rates with QGIS® (3.22.8). As for temporal dynamics, time series were decomposed and presented in the form of graphs showing the chronological evolution of VDPV cases and their seasonal trend, using R.4.0 software package.

Results: A total of 1196 Cases of VDPV types 1, 2 and 3 were recorded in the biological confirmation databases of the INRB and the Expanded Program of Immunization during the study period across 25 provinces. The eastern part of the country reports the most cases. The general trend is upwards, with a peak in 2022 of 527 cases, whereas in 2021 there was a notable drop of 31 cases. The study of the spatiotemporal dynamics of VDPV cases in the DRC (2018 - 2023) highlights a convincing fact, which is spatial heterogeneity. This would be linked to climatic and environmental factors. Analysis of the temporal breakdown suggests a seasonal pattern, with peaks between the months of September and December, considered to be rainy periods in some provinces. Moreover, in endemic countries and areas, PVS has a seasonal pattern that varies according to geographical region. In tropical or semi-tropical regions, PV circulation tends to be cyclical and is often associated with the rainy season.

Conclusion: This study of the temporal and spatial dynamics of VDPV has shown the extent of variant poliovirus epidemics and their heterogeneous distribution in the DRC. During the 6 years of the study (2018 - 2023), almost all the Health Zones were hit by VDPV epidemics. The eastern part was the most impacted. The seasonal component is well marked suggesting a rise in detection in the rainy season and during pivotal periods of climate change. This analysis highlights the contribution of the seasonal component to poliovirus circulation; the variation in relative humidity according to season and health zones can partly explain fluctuations in the number of VDPV cases. This result opens the way to taking into account the seasonal component of PV transmission.

 

Author (s) Details

Jean Blaise Yobo Iyala
Institut Régional de Santé Publique (IRSP), Université Abomey-Calavi (UAC), Ouidah, Bénin, Programme Elargi de Vaccination (PEV), Kinshasa, Congo and Institut One Health Pour l’Afrique (INOHA), Université de Kinshasa, Kinshasa, Congo.

 

Comlan Cyriaque Degbey
Institut Régional de Santé Publique (IRSP), Université Abomey-Calavi (UAC), Ouidah, Bénin.

 

N’Kpingou Nadakou
Institut Régional de Santé Publique (IRSP), Université Abomey-Calavi (UAC), Ouidah, Bénin.

 

Ounoussa Tapha
Institut Régional de Santé Publique (IRSP), Université Abomey-Calavi (UAC), Ouidah, Bénin.

 

Eveline Soclo
Institut Régional de Santé Publique (IRSP), Université Abomey-Calavi (UAC), Ouidah, Bénin.

 

Moise Gimiko
Programme Elargi de Vaccination (PEV), Kinshasa, Congo.

 

Fabrice Mawa
Programme Elargi de Vaccination (PEV), Kinshasa, Congo and Comité des Opérations d’Urgence POLIO (COUP), Kinshasa, Congo.

 

Chaltin Ambanga
Programme Elargi de Vaccination (PEV), Kinshasa, Congo.

 

Riziki Yogolelo
Institut National des Recherches Biomédicales (INRB), Kinshasa, Congo.

 

Désiré Ekanga
Ministère de la Santé Publique Hygiène et Prévention, Kinshasa, Congo.

 

Jean Claude Onema
Ministère de la Santé Publique Hygiène et Prévention, Kinshasa, Congo.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/msraa/v2/5113

Dynamic and Physical Processes Associated with Orographic Precipitation in a Conditionally Unstable, Low-cape and High-speed Wind | Chapter 7 | Geography, Earth Science and Environment: Research Highlights Vol. 4

 Orographic effects on precipitation in a conditionally unstable, low convective available potential energy (CAPE), and high-speed wind are investigated by a series of systematic two- and three-dimensional idealized numerical experiments. Sensitivity experiments are performed with a flow with low CAPE to assess the evolution of orographic precipitation in an environment similar to that observed in tropical cyclones, which, unexpectedly, show that precipitation is nearly doubled compared to that with high CAPE. The heavy rain production in the low CAPE case is explained by the following microphysical processes: (1) warm-rain formation processes (auto-conversion and accretion) are more effective, and (2) strong downdraft and advection-induced evaporation tend to deplete precipitation before reaching the ground, which overcomes the intense rain production via graupel and snow melting in high CAPE case. Overall, both in 2D and 3D high-wind simulations, the pattern of the precipitation distribution resembles the bell-shaped mountain profile with the maximum located over the mountain peak, which may be applicable to climate prediction of orographic precipitation.

 

Author (s) Details

 

Yuh-Lang Lin
North Carolina A&T State University, Greensboro, North Carolina, USA.

 

Gökhan Sever
Argonne National Laboratory, Lemont, Illinois, USA.

 

Please see the book here:- https://doi.org/10.9734/bpi/geserh/v4/4126

Design and Development of a Dynamic Boot Loader for Loading an Operating System: An Update | Chapter 6 | Research Updates in Mathematics and Computer Science Vol. 1

 The purpose of this paper is to design a dynamic boot loader which removes the BIOS dependency and allows user to boot from USB without changing CMOS settings. Boot Loader is the crucial program that loads the operating system in memory and initializes the system. In today’s world people are constantly on the move and portable system are in demand specially the USB devices due to its portability and accessibility compared to CD/DVD drives. To boot from USB, the user needs to change the boot order and choose the USB to start the booting process from USB. The available boot process is static which is dependent on user changing the BIOS settings. The USB is devised as plug and play portable system with puppy Linux and newly developed dynamic boot loader. The device is experimented on a computer machine with 8 GB RAM, i5 processor, 64-bit Operating system and windows 7 and observed that nearly 50% reduction in booting time i.e., the time spent in changing the boot order is eliminated compared to the static boot loader. The time spent in the BIOS is dependent on the user knowledge in changing the boot priority. The portable system allows the user to work in ease in any environment with minimum requirement of Windows XP and USB 2.0 compatible system. Since the OS runs from the USB and not dependent on the operating system of the machine, the proposed design achieves security for the data stored as well as make the environment secure. The kernel image can be customized as per the requirement of the user. This will greatly improve the loading time of the OS to the host machine.

Author(s) Details:

Alycia Sebastian,
Department of Information Technology, Al Zahra College for Women, Oman.

K. Siva Sankar,
Department of Information Technology, Noorul Islam Centre for Higher Education, Tamil Nadu, India.

Please see the link here: https://stm.bookpi.org/RUMCS-V1/article/view/13673

Keywords: Boot loader, dynamic, operating system, USB, open-source OS

Enhanced Model Based Algorithm to Reinforce PV System with Optimized Tracking Capability | Chapter 6 | Contemporary Perspective on Science, Technology and Research Vol. 4

To achieve a reliable and efficient system operation, this study presents an optimized algorithm which enhances the model-based (MB) tracking capability so as to overcome major deficiencies as discussed below. Photovoltaic (PV) power has become the most attractive choice among various renewable resources. However, one major challenge associated with PV interfacing is its intermittent output characteristic which varies dramatically with the operating conditions. Thus, designing an effective maximum power point tracking (MPPT) algorithm is a key aspect for optimizing PV system performance. Numerous MPPT algorithms have been proposed earlier having their own specific advantages. However, these are found to have two major limitations which have to be essentially addressed. Firstly, they become ineffective in the dynamic conditions where there is rapid change in environmental parameters like insolation and temperature. Secondly, they fail to discriminate between global and local peaks under partial shading conditions. Effectiveness of proposed tracking algorithm is tested by obtaining PV power characteristics under dynamic conditions where different parameters are varied alternately. On the basis of modified governing equations and incorporating the precised estimation of parameters, it predetermines the MPP analytically. First simulated results are obtained where it is tested for dynamic variations of all the three parameters. Then the experimental validation is carried out on a 2 KW installed panel where real time data is recorded through CR1000 data logger and environmental parameters are sensed with elements like pyranometer, humidity sensor, etc. Numerous experimental results are analyzed for tracked MPP in the dynamic conditions, which are then summarized in tabular forms. These are finally plotted and compared with simulated results to illustrate the effectiveness of proposed MB algorithm. Thus, it has been verified that MB algorithm is very efficient and effective for tracking not only in dynamically varying insolation or temperature but additionally it is equally capable for typical shaded panels also.

Author(s) Details:

Md. Ehtesham,
Department of Electrical and Electronics, Maulana Azad National Urdu University, Cuttack Campus, India.

Mohmmad Ahmad,
Department of Electrical Engineering, Rajkiya Engineering College, Bijnor, India.

Please see the link here: https://stm.bookpi.org/CPSTR-V4/article/view/13139

The Effects of Frequency and Pivot Flexibility on the Dynamic Properties of Tilting-Pad Journal Bearings | Chapter 04 | Research Developments in Science and Technology Vol. 5

 Tilting-pad journal bearings (TPJB) dynamic modelling must take into account the frequency dependency of the dynamic parameters, according to tribologists. Blades, impellers, and seals in industrial compressors, turbines, and other rotating devices cause instability, resulting in dominating vibratory frequencies that are often significantly different from rotational frequency. Though the literature has supplied relevant methodologies and numerical data, the design community does not have a complete grasp of the physics of TPJB frequency dependence, and theorists and experimentalists frequently disagree. This study is based on a single-pad, two-degree-of-freedom model that establishes a foundation for comprehending the various geometries and operating circumstances associated with frequency dependence for a complete bearing. The analytical results show that both stiffness and stiffness. The frequency dependency is principally connected with the pad rotational damping and the flexibility of the pivot contact region that provides support for the pad, as shown by and damping coefficients. This research aims to give insight into the role of pivot flexibility in conjunction with fluid film in order to assist analysts in reaching a consensus between theory and experiment.

This article is a revised and enlarged version of a paper delivered at the ASME 2019 Turbo Expo, which took place from June 17 to 21 in Phoenix, Arizona. The work was titled "On the Frequency Dependency of Tilting-Pad Journal Bearings" and has the number GT2019-90195.

Author(S) Details

Laurence F. Wagner
Rotor Bearing Solutions Intl. LLC, 5211 Mountainview Rd., Winston Salem, NC 27104, USA.

Paul E. Allaire
Rotor Bearing Solutions Intl. LLC, 5211 Mountainview Rd., Winston Salem, NC 27104, USA.

View Book:- https://stm.bookpi.org/RDST-V5/article/view/6865