The purpose of this study was to investigate the effect of using synchronous and asynchronous communication tools in online group activities to develop collaborative learning skills. An experimental study was implemented on a sample of faculty of education students in Mansoura University. The sample was divided into two groups, a group studied using synchronous communication tools, and the othe...

Aiming to offer a framework for blended learning to the teaching of proof theory, the present paper describes an interactive tutorial, called TryLogic, teaching how to solve logical conjectures either by proofs or refutations. The paper also describes the integration of our infrastructure with the Virtual Learning Environment Moodle through the IMS Learning Tools Interoperability specification,...

With the advent of object oriented database systems, there is an urgent need to define methodologies and tools for mapping conceptual schemes into object oriented ones. The evolution and the diversity of OO models on the one hand, and the increase of user needs on the other hand, ar the two factors that make these tools require important flexibility properties, that is to say easiness in mainte...

In this paper, we investigate the robust stability problem of a class of LTI discrete uncertain singularly perturbed time-delay systems. If the singular perturbation parameter of these systems is sufficiently small, they can be separated into two reduced-order subsystems, the slow subsystem and fast subsystem. Two stability criteria for the slow and fast subsystem of the uncertain system are th...

although more than 98% of the human genome is transcribed, most of these transcripts are not translated into proteins. rather, they are considered as non-coding rnas. micrornas (mirnas) are very short non-coding rnas approximately 22 nucleotides in length which regulate many key processes of cells such as growth, proliferation, differentiation, cell cycle, apoptosis (programmed cell death) and ...

We describe a three-dimensional human-computer interface for neurosurgical visualization. The interface is based on the two-handed physical manipulation of hand-held tools, or "props", in free space. These user interface "props" facilitate transfer of the user's skills for manipulating tools with two hands to the operation of a user interface for visualizing 3D medical images, without need for ...

Users of hand tools expect that tools after ergonomic changes in design will require less muscular activity and cause fewer musculoskeletal disorders than conventional tools. Reports on evaluation of ergonomic design changes in hand tools are controversial. In this study, we measured the effect of changes in tool design with physiological cost of performance and subjective ratings in a simulate...

Recent publications estimate the prevalence of human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) exceeds 50%, and this rate is likely higher among older patients. Cognitive impairment may impact medication adherence, and symptomatic impairment has been linked to all-cause mortality providing some impetus for early detection. There are currently insufficient data to i...