Threshold dynamics in mathematical models for mosquito- and rodent-borne diseases with seasonality

The Ph.D. thesis investigates the impact of the periodicity of weather on the spread of malaria, Zika fever, and Lassa fever by applying non-autonomous compartmental population models with time-dependent (periodic) parameters. The dynamics of the system is characterized by the basic reproduction number ($\mathcal{R}_0$) of periodic compartmental models, defined as the spectral radius of an integral operator acting on the space of continuous periodic functions, and it has also been shown that the reproduction number is a threshold parameter with respect to disease extinction or persistence. Our aim is to show that the disease-free periodic solution of our newly established models is globally asymptotically stable if $\mathcal{R}_0 1$, there exists at least one positive $\omega$-periodic solution. We provide numerical studies and give examples to describe what kind of parameter changes might trigger the periodic recurrence of the disease

Applied Basic Science of the Auricular Cartilage

Cartilage is an essential component of human body, and it is present in any region of the body. Auricular cartilages play an essential role in esthetic aspect and shape of the face. Therefore, comprehensive understanding of the applied basic science of the cartilage of the ear is essential to understand the pathophysiology of diseases that occur in this region, how much it is resistant to infections and invasion by malignancies and how postsurgical and postinfection healing happen

A mathematical model for the spread of Varroa mites in honeybee populations: two simulation scenarios with seasonality

We formulate and study a mathematical model for a honeybee colony infected with Varroa mites which describes the parallel phenomena of the spread of both the mites and the virus transmitted by them. We extend our previous model by including infected forager bees and considering model parameters as time-periodic functions. Firstly, we study the autonomous model and show the stability of equilibria. We present two simulation scenarios to study the impact of seasonality on the spread of Varroa mites and the disease they carry. Numerical studies are given to show how the parameter changes might lead to the colony's failure

The Profile of Head CT Scan Findings in Patients at Sebha Medical Center, Libya

Background: Computerized tomography (CT) is one of the most widely available and used methods of imaging. There are no known results published to show the most frequent findings on CT Scans of head in Sebha Medical Center in South Libya or the incidence of the different findings detected on the scans done in our region.Objectives: To study the characteristics of patients who underwent CT scan of head in our center, to investigate the most common findings in these patients, and to describe the distribution of the findings in relation to patients’ age and sex.Materials and Methods: This was a retrospective observational descriptive study that involved reviewing the CT scans of 255 patients who underwent Head CT in our center in the period between the 8th of March 2015 and 9th of April 2015. The collected data were analyzed using SPSS program (version 20).Results: Patients’ age ranged from one month to 89 years of age. Almost equal numbers of male and females were found (129 and 126 respectively). Sixty eight percent of the cases had normal scans. The most common abnormalities were: brain infarction (11.2%), brain edema (6.1%), intracerebral hemorrhage (4.7%) and hydrocephalus (3.6%). Other findings were: skull fractures (3.2%), subdural hematomas (3.2%), masses (1.8%), subarachnoid hemorrhage (1.1%) and intraventricular hemorrhage (1.1%).Conclusion: Most of the cases that undergo CT scan of head in south Libya have no detectable abnormalities by CT. The most common abnormalities seen are: infarctions (both old and new ones), brain edema, intracerebral hemorrhage and hydrocephalus.Keywords: Head CT, South Libya, infarctions, intracerebral hemorrhage, intraventricular hemorrhage, subdural hematoma, skull fracture, brain edema, hydrocephalus, intracranial masses

A Mathematical Model for Zika Virus Infection and Microcephaly Risk Considering Sexual and Vertical Transmission

We establish a compartmental model for Zika virus disease transmission, with particular attention paid to microcephaly, the main threat of the disease. To this end, we consider separate microcephaly-related compartments for affected infants, as well as the role of asymptomatic carriers, the influence of seasonality and transmission through sexual contact. We determine the basic reproduction number of the corresponding time-dependent model and time-constant model and study the dependence of this value on the mosquito-related parameters. In addition, we demonstrate the global stability of the disease-free periodic solution if R01. We fit our model to data from Colombia between 2015 and 2017 as a case study. The fitting is used to figure out how sexual transmission affects the number of cases among women as well as the number of microcephaly cases. Our sensitivity analyses conclude that the most effective ways to prevent Zika-related microcephaly cases are preventing mosquito bites and controlling mosquito populations, as well as providing protection during sexual contact

Ankylosing spondylitis: a case report with review of literature

Background: Ankylosing spondylitis is a relatively common worldwide chronic inflammatory disease that usually affects spine, sacroiliac joints in addition to peripheral joints and affects multiple other tissues, which can progress to bony fusion of the spine.Objective: To fill the gap of the absence of a published description of this condition in Libyan patients and to compare of the clinical presentation and other aspect of the condition in a Libyan patient with what is known worldwide.Materials and Methods: A case report of a 60 year old Libyan male who has Ankylosing spondylitis and then review the available literature.Results: The patient has been having a chronic low back pain and stiffness for the last 26 years. His symptoms are most severe in morning and improve with movement. He developed stiffness and limitation of movement of the neck and restriction of movements of the shoulder and hips. Examination showed kyphosis and limited neck movement and decreased chest expansion. His score on Bath Ankylosing Spondylitis Disease Activity Index is 6. His x-rays showed bamboo spine appearance of spine and osteoarthritis in both shoulder joints and hip joints. His presentation fits both European Spondyloarthropathy Study Group diagnostic criteria for spondyloarthropathies and the modified New York Criteria.Conclusion: Our Libyan patient shows a classical clinical and radiological picture of the condition and the diagnostic criteria and severity index could be applied easily to his cases.Keywords: Ankylosing spondylitis, Spondyloarthritis, back pain, back stiffness, bamboo spin

Management of Infrastructure For Water and Petroleum Demand in KSA By GIS

The purpose of this paper  is showing, how Geographical  Information Systems (GIS ) can be used to support infrastructure  planners and analyst  on water and petroleum demand of a local area in the Kingdom of Saudi Arabia (KSA). The first part of this work  discusses the issue of analysis, design and creating  the geodatabase system  of KSA land and infrastructure  using Stylus Studio XML editor, describing the components of the whole system of Subareas in Saudi  Arabia  affecting local infrastructure  planning and analyzing which include of specific  area and facilities management. The second part defines the creation of the GIS  application of the discussed field having the GIS  functions of the infrastructure discusses the  geodatabase of the application of GIS  In infrastructure   in Saudi Arabia districts. The third part defines the  results of the statistics analysis populations  in the Subareas, specify the relation between water resources and the elevations of subareas, the data of the layers of roads, railroads existing in Saudi Arabia  specially in the eastern area where most petroleum s wells are found.   Using Google earth to show the elevation of the subareas and the relation with the water resources. Three groups of GIS  forms was produced  they are the geodatabase of the Saudi Arabia (area, subareas and main cities) ,water resources  layers (water  in land , water  area and land cover ) , roads, railroads  and elevations layers. The main contribution in the paper, discussed the infrastructure and the  results of the statistics analysis populations  in the subareas, specify the relation between water resources and the elevations of subareas of the data layers of roads, railroads existing in Saudi Arabia, especially in the eastern area where most petroleum's wells are found production and exploration of  petroleum including the geodatabase of wells of petroleum distributed in Saudi Arabia  finding the locations using Google earth map, satellites to locate the areas of producing petroleum. Keywords: GIS, Water in land , Water area, Railroad, Elevation ,XML Schema