Cryo-EM and the elucidation of new macromolecular structures: Random Conical Tilt revisited

Cryo-Electron Microscopy (cryo-EM) of macromolecular complexes is a fundamental structural biology technique which is expanding at a very fast pace. Key to its success in elucidating the three-dimensional structure of a macromolecular complex, especially of small and non-symmetric ones, is the ability to start from a low resolution map, which is subsequently refined with the actual images collected at the microscope. There are several methods to produce this first structure. Among them, Random Conical Tilt (RCT) plays a prominent role due to its unbiased nature (it can create an initial model based on experimental measurements). In this article, we revise the fundamental mathematical expressions supporting RCT, providing new expressions handling all key geometrical parameters without the need of intermediate operations, leading to improved automation and overall reliability, essential for the success of cryo-EM when analyzing new complexes. We show that the here proposed RCT workflow based on the new formulation performs very well in practical cases, requiring very few image pairs (as low as 13 image pairs in one of our examples) to obtain relevant 3D maps.We thank Dr. Llorca for his support during the acquisition of the C3b images and Dr. Shaikh for his support in the use of Spider for the RCT reconstructions. The authors would like to acknowledge economical support from the Spanish Ministry of Economy and Competitiveness through grants AIC-A-2011-0638 and BIO2013-44647-R, the Comunidad de Madrid through grant CAM (S2010/BMD-2305), as well as a postdoctoral Juan de la Cierva grant with reference JCI-2011-10185 to Javier Vargas. Vahid Abrishami is a holder of La Caixa scholarship and C.O.S. Sorzano is recipient of a Ramon y Cajal fellowship

IMPORTANCE OF IMPLEMENTING OPTIMAL LEARNING MANAGEMENT SYSTEMS FOR E LEARNING IN HIGHER EDUCATION Citation download: (BibTeX) (ris) (plaintext) IMPORTANCE OF IMPLEMENTING OPTIMAL LEARNING MANAGEMENT SYSTEMS FOR E LEARNING IN HIGHER EDUCATION

Over the last few years online education has shown a significant boom in Higher Education Institutions. Every day more and more universities are implementing their educational programs through this mode, offering opportunities for those people who cannot carry out their studies face to face. This educational mode offers a series of advantages, to highlight some of them for example, access to materials and content at any time and at any place, all that is needed is a computer and a connection to Internet; the students have an active role in their process of learning, meaning that they are not restricted recipients of information, but that it is part of their formative process; there is an authentic management of knowledge among students (exchange of ideas, opinions, practices, experiences); and feedback. After the analysis of different solutions, it's important to find the effects of how the correct selection of a learning management system make an impact in the academic performance of students, comparing, the needs of student use, the ease of the user interface, management, design, etc. [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] Abstract Over the last few years online education has shown a significant boom in Higher Education Institutions. Every day more and more universities are implementing their educational programs through this mode, offering opportunities for those people who cannot carry out their studies face to face. This educational mode offers a series of advantages, to highlight some of them for example, access to materials and content at any time and at any place, all that is needed is a computer and an Internet connection; the students have an active role in their process of learning, meaning that they are not restricted recipients of information, but that it is part of their formative process; there is an authentic management of knowledge among students (exchange of ideas, opinions, practices, experiences); and feedback. Derived from the above, the number of students who carry out their studies under this educational mode has increased significantly, generating in Higher Education Institutions the need to acquire the appropriate technological infrastructure and the implementation of the most suitable Learning Management Systems (LMS) to fulfill the academic needs in this mode. In this sense, this research paper a comparative analysis is carried out between learning management systems with private software (Blackboard and WebCT) and of open source software (Moodle, Dokeos and Claroline). The parameters for comparison employed in this research, are the installation, personalization of the environment, functionality, resources management, groups and profiles, functionalities of Web 2.0 and the management of courses, in order to determine the optimum informatics solution for the implementation of educational programs in the mode of online education at the Computer Science Faculty of Mazatlan at the Autonomous University of Sinaloa. After the analysis of different solutions, it's important to find the effects of how the correct selection of a learning management system make an impact in the academic performance of students, comparing, the needs of student use, the ease of the user interface, management, design, etc

Cryo-EM and the elucidation of new macromolecular structures: Random Conical Tilt revisited

6 p.-2 fig. Sorzano, Carlos Oscar S. et al.Cryo-Electron Microscopy (cryo-EM) of macromolecular complexes is a fundamental structural biology technique which is expanding at a very fast pace. Key to its success in elucidating the threedimensional structure of a macromolecular complex, especially of small and non-symmetric ones, is the ability to start from a low resolution map, which is subsequently refined with the actual images collected at the microscope. There are several methods to produce this first structure. Among them, Random Conical Tilt (RCT) plays a prominent role due to its unbiased nature (it can create an initial model based on experimental measurements). In this article, we revise the fundamental mathematical expressions supporting RCT, providing new expressions handling all key geometrical parameters without the need of intermediate operations, leading to improved automation and overall reliability, essential for the success of cryo-EM when analyzing new complexes. We show that the here proposed RCT workflow based on the new formulation performs very well in practical cases, requiring very few image pairs (as low as 13 image pairs in one of our examples) to obtain relevant 3D maps.The authors would like to acknowledge economical support from the Spanish Ministry of Economy and Competitiveness through grants AICA-2011-0638 and BIO2013-44647-R, the Comunidad de Madrid through grant CAM (S2010/BMD-2305), as well as a postdoctoral Juan de la Cierva grant with reference JCI-2011-10185 to Javier Vargas.Peer reviewe