251 research outputs found

    Web Based Supervisor Supervisee Project Matching System

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    This study aims to develop a web-based supervisor-supervisee matching system to automatically match relevant research area topics and lecturers with students' knowledge and skills. The web-based supervisor-supervisee matching system is often used in educational organizations due to its effectiveness in facilitating and enhancing the monitoring of the supervision of project papers. To develop such system, there has been a combination of both the general methodology on one hand, and Nunamaker's system research process approach lo develop the system, on the other hand. The data used in this study was drawn from time tables and students' achievement records provided by the UUM IT faculty. Finally, data analysis was done following the development of the system which was based on the matching algorithm suggested in this paper. The algorithm was found to be good as it proved to have an accuracy of 81.39%, suggesting the efficiency and feasibility of the system

    Cardiovascular diseases related to ionizing radiation : the risk of low-dose exposure (Review)

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    Traditionally, non-cancer diseases are not considered as health risks following exposure to low doses of ionizing radiation. Indeed, non-cancer diseases are classified as deterministic tissue reactions, which are characterized by a threshold dose. It is judged that below an absorbed dose of 100 mGy, no clinically relevant tissue damage occurs, forming the basis for the current radiation protection system concerning non-cancer effects. Recent epidemiological findings point, however, to an excess risk of non-cancer diseases following exposure to lower doses of ionizing radiation than was previously thought. The evidence is the most sound for cardiovascular disease (CVD) and cataract. Due to limited statistical power, the dose-risk relationship is undetermined below 0.5 Gy; however, if this relationship proves to be without a threshold, it may have considerable impact on current low‑dose health risk estimates. In this review, we describe the CVD risk related to low doses of ionizing radiation, the clinical manifestation and the pathology of radiation-induced CVD, as well as the importance of the endothelium models in CVD research as a way forward to complement the epidemiological data with the underlying biological and molecular mechanisms

    Variable clinical phenotype in TBK1 mutations: case report of a novel mutation causing primary progressive aphasia and review of the literature

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    TBK1 mutations are a recently discovered cause of disorders in the frontotemporal dementia (FTD)-amyotrophic lateral sclerosis (ALS) spectrum. We describe a novel L683* mutation, predicted to cause a truncated protein and therefore be pathogenic, in a patient presenting with nonfluent variant primary progressive aphasia (PPA) at the age of 65. Her disease progressed over the following years, leading to her being mute and wheelchair bound seven years into her illness. Brain imaging showed asymmetrical left-sided predominant atrophy affecting the frontal, insular and temporal cortices as well as the striatum in particular. Review of the literature found 60 different nonsense, frameshift, deletion or splice site mutations, including the newly described mutation, with data on clinical diagnosis available in 110 people: 58% of the cases presented with an ALS syndrome, 16% with an FTD-ALS overlap, 19% with a cognitive presentation (including behavioural variant FTD (bvFTD) and PPA) and 4% with atypical parkinsonism. Age at onset (AAO) data was available in 75 people: mean (standard deviation) AAO was 57.5 (10.3) in those with ALS, which was significantly younger than those with a cognitive presentation (AAO = 65.1 (10.5), p = 0.008), or atypical parkinsonism (AAO = 68.3 (8.7), p = 0.021), with a trend compared with the FTD-ALS group (AAO = 61.9 (7.0), p=0.065); there was no significant difference in AAO between the other groups. In conclusion, clinical syndromes across the whole FTD-ALS-atypical parkinsonism spectrum have been reported in conjunction with mutations in TBK1. It is therefore important to include TBK1 on future gene panels for each of these disorders, and to suspect such mutations particularly when there are multiple different phenotypes in the same family

    The development of language levels in children with intellectual disabilities

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    تهدف هذه الدراسة إلى تقديم تصور واضح حول النماذج المختلفة لاكتساب مستويات اللغة للأطفال المعاقين عقليا من ذوي الاحتياجات الخاصة. ولتحقيق ذلك قامت الباحثتان بمراجعة بعض الأدبيات والدراسات السابقة التي تناولت هذا الموضوع.  وباستخدام المنهج الوصفي المقارن بين التطور الطبيعي للأطفال العاديين والأطفال من ذوي الإعاقة العقلية بتتبع نمو مستويات اللغة والمتمثلة في المستوى الفونولوجي، المستوى النحوي، المستوى الدلالي والمستوى البراغماتي لديهم. واتضح من خلال المقارنة بين الفئتين من الأطفال، بأن الأطفال المعاقين عقليا يتبعون نفس المبادئ العالمية فيما يتعلق باكتساب مستويات اللغة الأربعة لكن مع وجود حالات تأخير مختلفة لديهم مقارنة بالأطفال العاديين.This study aims to provide a clear conception of the different models of acquisition of language levels for children with intellectual disabilities with special needs. To achieve this, the two researchers reviewed some of the literature and previous studies that addressed this topic. And using the descriptive comparative approach between the normal development of normal children and mentally handicapped children by following the growth of the language levels represented in the phonological level, the grammatical level, the semantic level and their pragmatic level. And it became clear by comparing the two groups of children, that mentally handicapped children follow the same universal principles regarding the acquisition of the four language levels, but with different lags than they have compared to normal children

    Selected Endothelial Responses after Ionizing Radiation Exposure

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    Along with the development of novel chemotherapeutic agents, radiation therapy has revolutionized the prognosis of patients with various cancers. However, with a longer life expectancy, radiation treatment-related comorbidity, like cardiovascular diseases (CVDs), becomes an issue for cancer survivors. In addition, exposure to X-rays for medical diagnostics is dramatically increasing at the present times. A pressing question is whether or not exposure to these very low doses can cause health damage. Below 0.5 gray (Gy), an increased risk cannot be evidenced by epidemiology alone, and in vitro and in vivo mechanistic studies focused on the elucidation of molecular signaling pathways are needed. Given the critical role of the endothelium in normal vascular functions, a complete understanding of radiation-induced endothelial dysfunction is crucial. In this way, the current radiation protection system could be refined if needed, making it possible to more accurately assess the cardiovascular risk in the low-dose region. Finally, radiation-induced CVD, like CVD in general, is a progressive disorder that may take years to decades to manifest. Therefore, experimental studies are warranted to fulfill the urgent need to identify noninvasive biomarkers for an early detection and potential interventions—together with a healthy lifestyle—that may prevent or mitigate these adverse effects

    Selection Strategy of Small Mammalian Preys by the Common Genet Genetta Genetta between Natural and Anthropized Environments in Edough Forest Massif (Northeastern Algeria)

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    We analyzed fluctuations in of small mammals’ biodiversity through the winter diet of the common genet Genetta genetta (Linnaeus, 1958), to deduce the predator - adopted strategy according to the habitat conditions in which it occurs, particularly in anthropogenic environments. The field sampling was conducted during the 2020 winter season, in two contrasting environments of the Edough mountain range: natural site (Ain Boukal), and anthropized site (Bouzizi landfill). The analysis of 30 collected excrements in each of the two sites, allowed us to identify different food categories including small mammals. The result shows that the common genet is an excellent sampler of small mammals by consuming at least four taxonomic genera. The results also show that despite that the genet is a generalist predator with a wide food spectrum, the results show that it had exercised a selectivity on small mammals, preferentially on genera Apodemus which was abundant in the natural habitat. However, in the anthropized habitats, the genet was opportunistic feeding on waste and abundant small mammals, mainly for the genera Rattus

    Inflammatory cytokine release by vascular cells after X-irradiation

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    Non-conventional apoptotic response to ionising radiation mediated by N-methyl D-aspartate receptors in immature neuronal cells

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    During cortical development, N-methyl D-aspartate (NMDA) receptors are highly involved in neuronal maturation and synapse establishment. Their implication in the phenomenon of excitotoxicity has been extensively described in several neurodegenerative diseases due to the permissive entry of Ca2+ ions and massive accumulation in the intracellular compartment, which is highly toxic to cells. Ionising radiation is also a source of stress to the cells, particularly immature neurons. Their capacity to induce cell death has been described for various cell types either by directly damaging the DNA or indirectly through the generation of reactive oxygen species responsible for the activation of a battery of stress response effectors leading in certain cases, to cell death. In this study, in order to determine whether a link exists between NMDA receptors-mediated excitotoxicity and radiation-induced cell death, we evaluated radiation-induced cell death in vitro and in vivo in maturing neurons during the fetal period. Cell death induction was assessed by TUNEL, caspase-3 activity and DNA ladder assays, with or without the administration of dizocilpine (MK-801), a non-competitive NMDA receptor antagonist which blocks neuronal Ca2+ influx. To further investigate the possible involvement of Ca2+-dependent enzyme activation, known to occur at high Ca2+ concentrations, we examined the protective effect of a calpain inhibitor on cell death induced by radiation. Doses ranging from 0.2 to 0.6 Gy of X-rays elicited a clear apoptotic response that was prevented by the injection of dizocilpine (MK-801) or calpain inhibitor. These data demonstrate the involvement of NMDA receptors in radiation-induced neuronal death by the activation of downstream effectors, including calpain-related pathways. An increased apoptotic process elicited by radiation, occurring independently of the normal developmental scheme, may eliminate post-mitotic but immature neuronal cells and deeply impair the establishment of the neuronal network, which in the case of cortical development is critical for cognitive capacities

    Differential response to acute low dose radiation in primary and immortalized endothelial cells

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    Purpose : The low dose radiation response of primary human umbilical vein endothelial cells (HUVEC) and its immortalized derivative, the EA.hy926 cell line, was evaluated and compared. Material and methods: DNA damage and repair, cell cycle progression, apoptosis and cellular morphology in HUVEC and EA.hy926 were evaluated after exposure to low (0.05-0.5 Gy) and high doses (2 and 5 Gy) of acute X-rays. Results : Subtle, but significant increases in DNA double-strand breaks (DSB) were observed in HUVEC and EA.hy926 30 min after low dose irradiation (0.05 Gy). Compared to high dose irradiation (2 Gy), relatively more DSB/Gy were formed after low dose irradiation. Also, we observed a dose-dependent increase in apoptotic cells, down to 0.5 Gy in HUVEC and 0.1 Gy in EA.hy926 cells. Furthermore, radiation induced significantly more apoptosis in EA.hy926 compared to HUVEC. Conclusions : We demonstrated for the first time that acute low doses of X-rays induce DNA damage and apoptosis in endothelial cells. Our results point to a non-linear dose-response relationship for DSB formation in endothelial cells. Furthermore, the observed difference in radiation-induced apoptosis points to a higher radiosensitivity of EA.hy926 compared to HUVEC, which should be taken into account when using these cells as models for studying the endothelium radiation response

    Combined exposure to simulated microgravity and acute or chronic radiation reduces neuronal network integrity and survival

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    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of Xrays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight
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