Non-Linear Langevin and Fractional Fokker-Planck Equations for Anomalous Diffusion by Levy Stable Processes

The~numerical solutions to a non-linear Fractional Fokker--Planck (FFP) equation are studied estimating the generalized diffusion coefficients. The~aim is to model anomalous diffusion using an FFP description with fractional velocity derivatives and Langevin dynamics where L\'{e}vy fluctuations are introduced to model the effect of non-local transport due to fractional diffusion in velocity space. Distribution functions are found using numerical means for varying degrees of fractionality of the stable L\'{e}vy distribution as solutions to the FFP equation. The~statistical properties of the distribution functions are assessed by a generalized normalized expectation measure and entropy and modified transport coefficient. The~transport coefficient significantly increases with decreasing fractality which is corroborated by analysis of experimental data.Comment: 20 pages 7 figure

NUMERICAL AND THEORETICAL INVESTIGATIONS OF FRACTIONAL DIFFERENTIAL EQUATIONS

Fractional calculus has been recently received huge attention from Mathematicians and engineers due to its importance in many real-life applications such as: fluid mechanics, electromagnetic, acoustics, chemistry, biology, physics and material sciences. In this thesis, we present numerical algorithms for solving fractional IVPs and system of fractional IVPs where two types of fractional derivatives are used: Caputo-Fabrizio, and Atangana-Baleanu-Caputo derivatives. These algorithms are developed based on modified Adams-Bashforth method. In addition, we discuss the theoretical solution of special class of fractional IVPs. Several examples are discussed to illustrate the efficiency and accuracy of the present schemes

Climate sensitivity to land use changes over the City of Brussels

Prompted with the ongoing and projected climate change, a wide range of cities have committed, not only to mitigate greenhouse gas emissions but also to implement different climate change adaptation measures. These measures serve to ensure the wellbeing of the urban population. In practice, however, the planning of realistic adaptation measures is a complex process. Prior to starting such endeavor, it may therefore be useful to explore the maximum potential benefit that can be gained through adaptation measures. In this work, simple, extreme yet realistic adaptation measures are proposed in terms of changes in albedo and vegetation fraction. The impact of these land-use scenarios is explored by use of the land surface model SURFEX on the summer climate in terms of heat waves and the urban heat island for the city of Brussels. This is done for different periods in the future using the greenhouse gas scenario RCP8.5

The importance of phase dynamics in generation of coherent structures

In magnetically confined plasmas (MCP), the transport of heat and particles is determined by collisional and anomalous processes caused by turbulence. A collective effort has been put into modelling the turbulent transport in plasmas using various drift wave (DW) models. However, it is evident that large-scale phenomena have a significant impact on overall transport. Heat transport can be mediated by coherent structures such as streamers and blobs through the formation of avalanche-like events that are intermittent in nature, i.e., localized in time but of large amplitude. Furthermore, at the same time, there are structures such as zonal flows (ZF) and GAMs that are non-linearly generated and mitigate turbulent transport by shearing turbulent eddies. A common denominator for these large-scale structures is the synchronization of smaller scale modes or events to a coherent structure, where phases align in a localized region of space and time. Interestingly, phase synchronization is prevalent in many other fields, such as biological clocks, physiological organisms, and chemical reactors. The dynamical evolution of amplitude and phases have been investigated through simplified equations derived from the Hasegawa - Wakatani (HW) system, where effects of synchronization are studied.Theoretical studies often deal with the amplitudes of the fluctuating quantities and assume that the phases are randomly distributed according to the random phase approximation (RPA) and thus disregard the dynamics of the phases [1,2]. In this approximation, dynamical amplitudes have a slow variation compared to the rapid change of the phases, which are distributed uniformly over a $2 \pi$ interval [3]. There have been a few general approaches to the randomness in turbulence: the RPA, the diagrammatic method by Wyld and the cumulant expansions, with the aim of systematically characterizing intermittent behavior. Unless a specific case is studied, the diagrammatic method has a drawback since there is no consistent small expansion parameter and no normalization procedure available. Moreover, the intuitive picture of the RPA approach is tempting and is thus widely adopted in turbulence theory. The underlying assumption of randomness in the RPA for the phases of Fourier modes in nonlinearly interacting waves cannot be justified since the phases as well as the amplitudes evolve due to non-linear interactions that act on the same time scales for both. Thus, the phases cannot be randomized faster than the amplitudes, see further discussion in Refs. [4,5]. Understanding the generation of coherent structures and the effects of these structures on transport and turbulence is therefore of crucial importance. In regard to plasma dynamics, simplified models are of interest, assuming an expansion of the state in amplitude and phase, i.e., $\phi \sim \phi_0 \exp(i \theta)$, the basic dynamical equations yield one dynamical equation for the amplitude and one for the phase for each field in the model. In previous papers, models using the passive advected scalar [6] and the Burgers equation [1] where it was found that under certain conditions, the RPA assumption can be invalidated using a phase dependent force and the locking of phases may increase the energy transfer to other modes. The assumption of a fully stochastic phase state of the turbulence is more relevant for high values of scale separation with the energy spectrum following a $k^{−7/2}$ decay rate. The dynamic of the three-body interactions between the phases in the non-linear Burgers’ turbulence shows that the phases lock intermittently. This is due to the k dependence of the coupling strength in the non-linear term which reduces strongly for high-k range due to the dampening effect of the dissipation which does not allow locking of the phases of the small scales. For lower scale dependence the asynchronized and synchronized phases differ significantly, and one could expect the formation of coherent modulations in the latter case. Moreover, the HW have been studied [7] and the work on the predator-prey model of DW – ZF dynamics, it is observed that synchronization may be transferred between the two populations [8].In this work, we investigate the role of phase dynamics for turbulent fluctuations in a set of direct numerical simulation (DNS) of homogeneous Taylor-Green driven turbulence, simple 2D rotating turbulence flow. The model is the forced incompressible magnetohydrodynamic (MHD) equations. It should be noted that in the study of coupled oscillators describing chemical reactors, the Kuramoto model has been established, and it has been shown that synchronization occurs when a certain threshold is exceeded. In this case the system is strongly forced to generate a vortex and where the phase locking between close neighbours can be quantified

Inter-Linkage between FDI, Imports and Exchange Rate: An Empirical Evidence from Pakistan

Foreign Direct Investment (FDI) is a very important phenomenon of the millennium. It is considered a substitute and complementary for trade. Numerous researches regarding FDI and imports have been conducted, and contradictory results on complex relationship between FDI and Imports are found. The vector error correction model (VECM) and linear hypothesis testing have been applied by considering exchange rate as supplement for better and accurate modelling. The results of the study indicated short run as well as highly significant long run relationship among all variables under study. For imports causality runs from FDI to imports indicating FDI to be complementary variable for imports. Govt needs to implement policies which must boost up exports but curtail imports burden. In order to generate employment and reduce the balance of payments problems, it is therefore, suggested that government should opt and encourage FDI policies relevant to export oriented industries like manufacturing and production sectors along with the exploration of natural resources. Policies should aim to encourage FDI in industrial sector where the surge in import bill is compensated with export performance of the firms. Keywords: Foreign Direct Investment, Imports, Exchange rate and VECM

Assessment Of Predictive Value Of Serum Uric Acid Levels For Low Birth Weight In Pre-Eclampsia

OBJECTIVE: To assess the diagnostic accuracy of raised serum uric acid level in females with pre-eclampsia, in predicting low birth weight. SUBJESTS & METHODS: Cross sectional study carried out at Gynecology Department, FGSH Poly Clinic, Islamabad & duration of study was 6 months from July 21, 2021 to Jan 20, 2022. A total of 225 Preeclampsia pregnant female were clinically examined and included in the study. Blood sample were collected for serum uric acid and followed till the birth of the baby. RESULTS: The  study  included  age  ranged  from  18  up  to  40  years.  Average age was 28.69years +5.01SD. Sensitivity & specificity of uric acid level in Serum in diagnosis of low birth weight are 85.71%  and  81.42%  respectively while  it  has  positive  predictive & negative predictive value  of  51.43% &  96.13% respectively.  Diagnostic accuracy of uric acid level in serum was 82.22%. CONCLUSION: Uric acid level in serum is of great diagnostic and prognostic importance in women with pre-eclampsia & helps in predicting low birth weight

L’impact de la technologie d’information sur la performance des universités et la réussite des étudiants

Improving the quality of education is a priority for most developing countries. Policy makers generally agree that such improvements can bring about productive structural change and stimulate long-term economic growth. Governments face the challenge of identifying effective and technological ways to use their limited resources and improve the quality of education. Indeed, these resources are manifested in information technology, which has grown at an accelerated rate in recent decades, significantly impacting on the way universities operate and forcing them to rethink the way they conceptualize their teaching strategies. Information technology can provide universities with powerful strategic and tactical tools which, if properly applied and used, could bring great advantages in promoting and strengthening their competitiveness. Information technology is a means to facilitate communication and exchange of information as well as to facilitate knowledge sharing between different actors in the university. This is why universities invest in and govern their information technology assets and practices. At this level, information technology can be used to improve collaboration and networking among faculty, students and administrative officials, as it removes barriers to real-time communication and effective information sharing. As the existing literature illustrates, information technology appears to have positive correlations with improved academic performance and student success. The purpose of this paper is to examine the impact of information technology on academic performance and student success and to describe the factors that affect this impact.L'amélioration de la qualité de l’enseignement est une priorité pour la plupart des pays en développement. Les responsables politiques s'accordent généralement à dire que de telles améliorations peuvent entraîner des changements productifs structurels et stimuler la croissance économique à long terme. Les gouvernements font face au défi d'identifier des moyens efficaces et technologiques, d'utiliser leurs ressources limitées et d'améliorer la qualité de l'enseignement. En effet, ces ressources se manifestent dans les technologies d’information qui ont connu une croissance accélérée au cours des dernières décennies, ce qui a eu un impact considérable sur le mode de fonctionnement des universités et les a obligés à repenser la manière dont elles conceptualisent leurs stratégies d’enseignement. La technologie d’information peut fournir aux universités, s'elles sont correctement appliquées et utilisées, pourraient apporter de grands avantages dans la promotion et le renforcement de leur compétitivité de puissants outils stratégiques et tactiques qui, s'ils sont bien appliqués et utilisés, pourraient apporter des avantages concurrentiels dans la promotion et le renforcement de leur compétitivité. La technologie d’information est un moyen permettant de faciliter la communication et l'échange des informations ainsi que de faciliter le partage des connaissances entre les différents acteurs de l’université. C'est la raison pour laquelle les universités investissent dans leurs actifs et pratiques des technologies d’information et les gouvernent. À ce niveau, les technologies d’information peuvent servir à améliorer la collaboration et à créer des réseaux entre les enseignants, les étudiants et les fonctionnaires de l’administration, puisqu’elles éliminent les obstacles à la communication en temps réel et au partage efficace des informations. Comme l'illustre la littérature existante, la technologie d’information semble présenter des corrélations positives avec l'amélioration des performances universitaire et la réussite des étudiants. L'objectif du présent article est d'examiner l’impact de la technologie d’information sur la performance universitaire et la réussite des étudiants et de décrire les facteurs qui affectent cet impact

Allergic disease, corticosteroid use, and risk of Hodgkin lymphoma: A United Kingdom nationwide case-control study.

BACKGROUND: Immunodeficiency syndromes (acquired/congenital/iatrogenic) are known to increase Hodgkin lymphoma (HL) risk, but the effects of allergic immune dysregulation and corticosteroids are poorly understood. OBJECTIVE: We sought to assess the risk of HL associated with allergic disease (asthma, eczema, and allergic rhinitis) and corticosteroid use. METHODS: We conducted a case-control study using the United Kingdom Clinical Practice Research Datalink (CPRD) linked to hospital data. Multivariable logistic regression investigated associations between allergic diseases and HL after adjusting for established risk factors. Potential confounding or effect modification by steroid treatment were examined. RESULTS: One thousand two hundred thirty-six patients with HL were matched to 7416 control subjects. Immunosuppression was associated with 6-fold greater odds of HL (adjusted odds ratio [aOR], 6.18; 95% CI, 3.04-12.57), with minimal change after adjusting for steroids. Any prior allergic disease or eczema alone was associated with 1.4-fold increased odds of HL (aOR, 1.41 [95% CI, 1.24-1.60] and 1.41 [95% CI, 1.20-1.65], respectively). These associations decreased but remained significant after adjustment for steroids (aOR, 1.25 [95% CI, 1.09-1.43] and 1.27 [95% CI, 1.08-1.49], respectively). There was no effect modification by steroid use. Previous steroid treatment was associated with 1.4-fold greater HL odds (aOR, 1.38; 95% CI, 1.20-1.59). CONCLUSIONS: In addition to established risk factors (immunosuppression and infectious mononucleosis), allergic disease and eczema are risk factors for HL. This association is only partially explained by steroids, which are associated with increased HL risk. These findings add to the growing evidence that immune system malfunction after allergic disease or immunosuppression is central to HL development

Comparative analysis of N95 respirators fit testing with commercially available and in house reagent

Background: Due to COVID-19, thousands of healthcare workers have been affected and have lost their lives in the line of duty. For the protection of healthcare workers, WHO and CDC have made standard guidelines and requirements for PPE use. N95 masks are amongst the most readily used PPE by healthcare professionals and it is highly recommended by OSHA that every make and model of N95 should go through a fit test at least once in a year.Method: A total of 30 randomly selected healthcare professionals (who were a regular user of N95 respiratory masks) were subjected to assess in-house (saccharin sodium benzoate) reagent for use for standard qualitative fit testing in our hospital. Threshold testing with the in-house reagent at three different concentrations was performed prior to establish participants\u27 sensitivity to the reagent. After successful completion of threshold testing, fit test was performed on participants wearing an N95 mask.Results: All the participants included in the study passed the sensitivity testing with three concentrations of the reagents, while it was concluded that the concentration of the in-house reagent that was well suited for the sensitivity testing was a concentration of 1g/dl saccharin with 10g/dl sodium benzoate. For fit testing 12g/dl was found to be more appropriate.Discussion: Our study provided a low cost solution to ensure safety of healthcare workers who are regular users of N95 masks following guidelines implemented by OSHA and CDC.Conclusion: The in-house test solution prepared was found to be equally sensitive to its commercially available counterpart

Socioeconomic deprivation and regional variation in Hodgkin's lymphoma incidence in the UK: a population-based cohort study of 10 million individuals.

OBJECTIVES: Hodgkin's lymphoma (HL) is the the most common cancer in teenagers and young adults. This nationwide study conducted over a 25-year period in the UK investigates variation in HL incidence by age, sex, region and deprivation to identify trends and high-risk populations for HL development. DESIGN: Population-based cohort study. SETTING: Clinical Practice Research Datalink (CPRD) electronic primary care records linked to Hospital Episode Statistics and Index of Multiple Deprivation data were used. PARTICIPANTS: Data on 10 million individuals in the UK from 1992 to 2016 were analysed. PRIMARY AND SECONDARY OUTCOME MEASURES: Poisson models were used to explore differences in HL incidence by age, sex, region and deprivation. Age-specific HL incidence rates by sex and directly age-standardised incidence rates by region and deprivation group were calculated. RESULTS: A total of 2402 new cases of HL were identified over 78 569 436 person-years. There was significant variation in HL incidence by deprivation group. Individuals living in the most affluent areas had HL incidence 60% higher than those living in the most deprived (incidence rate ratios (IRR) 1.60, 95% CI 1.40 to 1.83), with strong evidence of a marked linear trend towards increasing HL incidence with decreasing deprivation (p=<0.001). There was significant regional variation in HL incidence across the UK, which persisted after adjusting for age, sex and deprivation (IRR 0.80-1.42, p=<0.001). CONCLUSIONS: This study identified high-risk regions for HL development in the UK and observed a trend towards higher incidence of HL in individuals living in less deprived areas. Consistent with findings from other immune-mediated diseases, this study supports the hypothesis that an affluent childhood environment may predispose to development of immune-related neoplasms, potentially through fewer immune challenges interfering with immune maturation in early life. Understanding the mechanisms behind this immune dysfunction could inform prevention, detection and treatment of HL and other immune diseases