Atmospheric conditions of extreme precipitation events in western Turkey for the period 2006–2015

This paper investigates the precipitation types and background physical mechanisms of extreme precipitation events (EPEs) over western Turkey during the period 2006–2015. The EPEs are described as the precipitation values above the 90th percentile obtained from the hourly precipitation dataset, which has high spatial resolution. Precipitation types associated with EPEs are identified by using radar outputs and the Lamb weather type (LWT) approach. It is found that EPEs occurred more frequently in the Marmara and Aegean regions during autumn and winter months. In Marmara, mainly 21&thinsp;%, 17&thinsp;%, and 15&thinsp;% of total autumn EPEs show convective, cyclonic, and sea-effect precipitation characteristics, respectively. While convective EPEs are seen more commonly in the southern portions, cyclonic and sea-effect-originated EPEs mainly affect the southwest and northeastern parts of Marmara. Among these three precipitation types, convective mechanisms generally produce more intense daily precipitation (66.1&thinsp;mm on average) in the Marmara Region under the proper synoptic conditions (high-pressure center over the Balkan Peninsula and low-pressure center over the eastern Mediterranean). Based on the hourly observations, convective types of extreme precipitation (EP) show two peak values during afternoon and evening times of the day and are linked to diurnal heating. In terms of the Aegean Region, cyclone-originated EP, which includes 65&thinsp;% of the total winter EPEs, is more common in the whole territory and reaches its peak value during the early hours of the day.</p

Increasing student engagement through virtual interactions: how?

Our ongoing research is focusing on identifying and taxonomising the elements and the factors that affect learner engagement with virtual worlds when hybrid virtual learning models are used. Our main hypothesis links learner engagement with interactions, both in the virtual world and in the physical classroom. In order to examine this subject, there is an elaboration on and consideration of aspects such as the learners’ prior experiences in the use of virtual worlds, their preconceptions about using them as a learning tool and the impact that the instructional designers’ choices have on enhancing the opportunities for interactions. In this paper, we examine the impact that the orientation process has on university students who study computer science and have almost no experience in the use of virtual worlds. Our findings suggest that the orientation process contributed positively to students’ smooth induction and that resulted in having meaningful and engaging interactions. Furthermore, students’ simultaneous coexistence in both environments eliminated the drawbacks of each educational approach and broadened the network of interactions

Epigenetic Silencing of Host Cell Defense Genes Enhances Intracellular Survival of the Rickettsial Pathogen Anaplasma phagocytophilum

Intracellular bacteria have evolved mechanisms that promote survival within hostile host environments, often resulting in functional dysregulation and disease. Using the Anaplasma phagocytophilum–infected granulocyte model, we establish a link between host chromatin modifications, defense gene transcription and intracellular bacterial infection. Infection of THP-1 cells with A. phagocytophilum led to silencing of host defense gene expression. Histone deacetylase 1 (HDAC1) expression, activity and binding to the defense gene promoters significantly increased during infection, which resulted in decreased histone H3 acetylation in infected cells. HDAC1 overexpression enhanced infection, whereas pharmacologic and siRNA HDAC1 inhibition significantly decreased bacterial load. HDAC2 does not seem to be involved, since HDAC2 silencing by siRNA had no effect on A. phagocytophilum intracellular propagation. These data indicate that HDAC up-regulation and epigenetic silencing of host cell defense genes is required for A. phagocytophilum infection. Bacterial epigenetic regulation of host cell gene transcription could be a general mechanism that enhances intracellular pathogen survival while altering cell function and promoting disease

A Qualitative Study About The Sustainable Usage Of Online Learning Environments | Çevrimiçi Öğrenme Ortamlarının Sürdürülebilir Kullanımına Ilişkin Nitel Bir Çalışma

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