Abstract Candida albicans is a commensal fungal pathogen that grows in yeast and hyphal forms in the human gut. C. albicans causes mucosal and cutaneous diseases that can result in significant mortality following systematic infections and it also exhibits drug resistance. Zebrafish have been an excellent model to investigate C. albicans infections because of their transparency and the availability of many transgenic lines. However, there is a limitation in using zebrafish as a model because the fish embryos cannot survive at 37°C therefore it is not suitable for studying Candida infections at physiological relevant human body temperature. In this thesis, the normal embryonic development of Arabian killifish (A. dispar) is investigated, revealing that embryogenesis was divided into 32 stages based on diagnostic patterns of development. A. dispar can also found to tolerate a wide range of temperatures and salinities. This suggests that A. dispar could be developed as a novel model to investigate host-pathogen interactions. The tolerance of A. dispar to high temperatures may in part be attributable to brown pigment cells with a highly fluorescent character that may have developed to allow the fish to adapt to live within extreme environmental conditions with strong sunlight and a wide range of temperatures (Chapter 3). In terms of Candida infections, this study examined A. dispar as a model to test C. albicans pathogenicity. The survival of A. dispar embryos following Candida infection showed a dose dependent relationship. We also found that A. dispar can survive longer than zebrafish after infection. Furthermore, C. albicans cells were observed to undergo a transition from yeast to hyphae at 37°C. An investigation of the ability of mutant strains of C. albicans with defects in cell wall mannosylation revealed a significant impact on virulence, host mortality, and the fishes’ immune response. The present study found that although the deletion of O- and N-mannan from the cell wall of C. albicans, affected fungal burden (attenuation), and the survival of the infected embryos per se was significantly decreased in the infections of the mutant strains compared to the WT. This data confirms the importance of the mannosylation state of the cell wall in triggering an immune recognition event (Chapter 4). A. dispar is also shown to be suitable for studying the effectiveness of 3 | P a g e antifungals. Fluconazole treatment of infected embryos and eggs promoted greater rates of survival at high doses, alongside a significant reduction of C. albicans CFUs (Chapter 4). When looking at the Candida-host interaction, we directly observed phagocytosed yeast cells within macrophages. Various detection methods were used to follow macrophages and neutrophils including Western blotting, immunostaining and histological staining (Sudan black and FITC-tyramide) allowing the monitoring of the time course of the immune cells. A biphasic response of macrophages was detected by L-plastin Western blotting, suggesting activation of two different type of macrophage: activated macrophage (M1) and alternative macrophage (M2). We also assayed reactive oxygen species (ROS) within infected embryos using a fluorescent probe (H2DCFDA), revealing the accumulation of the fluorescent probe at the sites of infection. Quantitative and qualitative analyses of the oxidative and immune response using the H2DCFDA and qPCR were also accomplished within A. dispar embryos after infection with both the WT and mutant strains of Candida albicans (WT, pmr1∆, mnt1-mnt2∆, and och1∆). The results confirmed that the mutant strains did not activate a host oxidative stress response nor immune cell accumulation when compared to WT, suggesting that the immune response is less activated against these mutants. Finally, a new transgenic line of A. dispar fish was developed using Betaactin-DsR-LoxP-GFP. The new transgenic A. dispar is suggested to be an ideal model for real time observation of host-pathogen interactions and for investigation of molecular functions of the immune response. Overall these results improve our understanding of the use of a new transparent fish model to study fungal pathogenesis and demonstrates the potential advantages of using this species in future studies of bacterial, fungal and viral pathogens at a physiologically relevant temperature for human infection. Such a model could lead us to investigate in more depth the key interactions between pathogens and their host and permit the screening and development of new antifungal therapies (that might target the pathogens directly or target the host immune system). View full metadata
This study aims to identify the anxiety pregnant women have of dying, in the light of some Demographic variables in Bethlehem (age, residence, and the mother's job). The descriptive method was used in this study. To achieve the study purposes, the researchers developed a questionnaire as a tool of study, which consisted of (19) paragraphs ,after been verified of its validity & stability.
The researchers distributed questionnaires, and then analyzed them. Results illustrated that the levels of anxiety pregnant women in Bethlehem had of dying was average, with a mean total score of (3.11), and with a standard deviation that had the total score of (0.476). Results also illustrated statistical differences in the pregn
... Show MoreWestern Scholars have criticized al the material on the point of reliability . Some have taken the unduly Sceptical view that nothing is to be trusted except Quran . The present study is based on opposing view that at least the material in the early biographers is to be accepted as true , except where there are particular reasons for thinking that an anecdote has been distorted ( or invented ) through legal or political motives. It is also assumed that most of the background material culled from a large number of vaired works , is sound . This standpoint .I would claim , leads to a coherent view of Muhammad's life and achievement.
This research means a study (the impact of the Arab-Islamic environment on contemporary painting, the artist Abd al-Rahman al-Suleiman as a model). The research falls into two axes: the first: the theoretical axis, and the second: the applied axis. The first axis dealt with an introduction that contained: (the research problem, its importance, its goal, its limits, and the definition of terms). This research aims to uncover (the impact of the Arab-Islamic environment on contemporary painting, and the artist Suleiman was a model). And the research limits spatially: Saudi Arabia, and temporally: 2010-2014. This theme included two topics: The first: the characteristics of the Saudi environment and its impact on art. The second: the s
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The research deals with the lyrical introduction in the commentary of Tarfa bin al-Abd as a formative system characterized by flexibility and richness of imagination, which achieved a formative treatment and a unique construction within the structures of the structural and semantic language. I dealt with the poetic verses represented by the lyrical introduction as a formative hypothesis, basing its goal on a methodological framework distributed on the problem that was summarized by the following question: Is it possible to look at the poetic pattern within the pre-Islamic poem / hanging blinking as a model, in its plastic dimensions and to identify the stylistic treatment that achieves the formation space within the poetic text. The rese
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This research dealt with the subject of negotiation skills of employees in public relations departments which is one of many skills supposed to be available to these employees. These skills combined help in the success of the job of public relations departments; and give them an important and vital role within the roles distributed in the departments of any government institution wither is governmental or non-governmental.
Negotiation is a skill that requires intelligence, tact, culture, information, intuition, and knowing to use the means of communication to access the information that is useful in reaching satisfactory results
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The operative system of theatrical performance depends on the construction of the scenographic space, as it constitutes the most aesthetic effect of the recipient, and the body of the theatrical discourse that contains the signs of the show, and it comes as an embodiment of the directing vision of the show director, so most of the world directors resorted to attention to the output treatment to establish the scenographic space, and thus it possesses a contrast in The embodiment of the directing vision according to the stylistic and hermeneutical dimension of the director, so the two researchers found the importance of studying the topic, and the study came under the title (Directing Treatments of the Scenographic Space in the Iraqi Theat
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In the present article, we implement the new iterative method proposed by Daftardar-Gejji and Jafari (NIM) [V. Daftardar-Gejji, H. Jafari, An iterative method for solving nonlinear functional equations, J. Math. Anal. Appl. 316 (2006) 753-763] to solve two problems; the first one is the problem of spread of a non-fatal disease in a population which is assumed to have constant size over the period of the epidemic, and the other one is the problem of the prey and predator. The results demonstrate that the method has many merits such as being derivative-free, overcome the difficulty arising in calculating Adomian polynomials to handle the nonlinear terms in Adomian Decomposition Method (ADM), does not require to calculate Lagrange multiplier a
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The study of improved model for measuring the total nuclear fusion cross section characteristics the D-D reaction may play an important role in deciding or determining the hot plasma parameters such as mean free path , the reaction rate , reactivity and energy for emitted neutrons or protons in our work we see the it is necessary to modify the empirical formulas included the total cross section in order to arrive or achieve good agreement with the international publish result.
Abstract:
Saudi Arabia and United States long relation could present an important
subject to understand alliance kind in international relations types. We trying
in this study to diagnose and analyze the Saudi Arabia and United States
model to find balance and unbalance statues and its influence on the
directions of Saudi Arabia foreign policy positions.
We divided the study in two parts, each part have many sections. The
first part deal with the historian emergence of Saudi Arabia state and its
development in three stages including its foreign relations with regions and
international powers. While the second part was dedicated in analyzing and
understanding the mechanism and active facts that drawing the Sa