University of Porto 8 articles published in JoVE Behavior Eye Movements in Visual Duration Perception: Disentangling Stimulus from Time in Predecisional Processes Dinis Catronas1, Nathércia Lima Torres1, Susana Silva1 1Center for Psychology at the University of Porto, Faculty of Psychology and Educational Sciences, University of Porto We present a protocol that employs eye tracking to monitor eye movements during an interval comparison (duration perception) task based on visual events. The aim is to provide a preliminary guide to separate oculomotor responses to duration perception tasks (comparison or discrimination of time intervals) from responses to the stimulus itself. Medicine A Minimally Invasive Model of Aortic Stenosis in Swine Rui Cerqueira*1,2, Liliana Moreira-Costa*1, Evangelia Beslika1,3, André Leite-Moreira1, Joana Silva3,4, Paula A. da Costa Martins3, Adelino Leite-Moreira1,2, André Lourenço1, Pedro Mendes-Ferreira1 1UnIC@RISE, Department of Surgery and Physiology, Faculty of Medicine, University of Porto, 2Department of Cardiothoracic Surgery, Hospital Universitário de São João, 3CARIM School for Cardiovascular Diseases, Maastricht University, 4Mirabilis Therapeutics This protocol describes a minimally invasive surgical procedure for ascending aortic banding in swine. Environment Quantification and Whole Genome Characterization of SARS-CoV-2 RNA in Wastewater and Air Samples José Gonçalves1,2,3, Priscilla Gomes da Silva4,5,6, Tom Koritnik3, Martin Bosilj3, Andrés Torres-Franco1,2, Israel Diaz1,2, Elisa Rodriguéz1,2, Eva Marcos2,3, João R. Mesquita4,5, Pedro García-Encina1,2 1Institute of Sustainable Processes, University of Valladolid, 2Department of Chemical Engineering and Environmental Technology, University of Valladolid, 3Department of Public Health Microbiology, National Laboratory of Health, Environment and Food, 4ICBAS - School of Medicine and Biomedical Sciences, Porto University, 5Epidemiology Research Unit (EPIUnit), Instituto de Saúde Pública da Universidade do Porto, 6Laboratório para a Investigação Integrativa e Translacional em Saúde Populacional (ITR) This protocol aims to quantify SARS-CoV-2 RNA in wastewater and air samples to be used for wastewater-based epidemiology studies and to assess the exposure risk to SARS-CoV-2 in indoor and outdoor aerosols. This protocol also describes a tiled amplicon long-template sequencing approach for SARS-CoV-2 whole genome characterization. Cancer Research Yeast As a Chassis for Developing Functional Assays to Study Human P53 Paola Monti1, Bartolomeo Bosco2, Sara Gomes3, Lucilia Saraiva*3, Gilberto Fronza*1, Alberto Inga*2 1Mutagenesis and Cancer Prevention Unit, Ospedale Policlinico San Martino, 2Department CIBIO, University of Trento, 3LAQV/REQUIMTE, Laboratory of Microbiology, Faculty of Pharmacy, University of Porto Presented here are four protocols to construct and exploit yeast Saccharomyces cerevisiae reporter strains to study human P53 transactivation potential, impacts of its various cancer-associated mutations, co-expressed interacting proteins, and the effects of specific small molecules. Bioengineering Comparable Decellularization of Fetal and Adult Cardiac Tissue Explants as 3D-like Platforms for In Vitro Studies Ana C. Silva1,2,3,4, Maria J. Oliveira1,2,5, Todd C McDevitt4,6, Mário A. Barbosa1,2,3, Diana S. Nascimento1,2, Perpétua Pinto-do-Ó1,2,3 1i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 2INEB - Instituto de Engenharia Biomédica, Universidade do Porto, 3Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4Gladstone Institute of Cardiovascular Disease, 5Faculty of Medicine, University of Porto, 6University of California San Francisco The cardiac extracellular matrix (ECM) is a complex network of molecules that orchestrate key processes in tissues and organs while enduring physiological remodeling throughout life. Standardized decellularization of fetal and adult hearts permits comparative experimental studies of both tissues in a 3D context by capturing native architecture and biomechanical properties. Neuroscience Modified Roller Tube Method for Precisely Localized and Repetitive Intermittent Imaging During Long-term Culture of Brain Slices in an Enclosed System Benjamin B. Fixman*1, Isaac W. Babcock*1, Laurie S. Minamide*1, Alisa E. Shaw1, Marina I. Oliveira da Silva1,2, Avery M. Runyan1, Michael T. Maloney1,3, Jeffrey J. Field1, James R. Bamburg1 1Department of Biochemistry and Molecular Biology and Molecular, Cellular and Integrated Neuroscience Program, Colorado State University, 2IBMC-Instituto de Biologia Molecular e Celular, i3S-Instituto de Investigaçãoe Inovação em Saúde, ICBAS, Universidade do Porto, 3Denali Therapeutics Presented here is a modified roller tube method for culturing and intermittent high-resolution imaging of rodent brain slices over many weeks with precise repositioning on photoetched coverslips. Neuronal viability and slice morphology are well maintained. Applications of this fully enclosed system using viruses for cell-type specific expression are provided. Developmental Biology A Standardized Approach for Multispecies Purification of Mammalian Male Germ Cells by Mechanical Tissue Dissociation and Flow Cytometry Ana C. Lima*1,2,3,4, Min Jung*1, Jannette Rusch1, Abul Usmani1, Alexandra M. Lopes3,4, Donald F. Conrad1 1Department of Genetics, Washington University School of Medicine, 2Graduate Program in Areas of Basic and Applied Biology (GABBA), Abel Salazar Institute of Biomedical Sciences, University of Porto, 3Instituto de Investigação e Inovação em Saúde, University of Porto, 4IPATIMUP - Instituto de Patologia e Imunologia Molecular da Universidade do Porto, 5Department of Pathology & Immunology, Washington University School of Medicine This work describes the standardization of a method to obtain purified germ cell populations from testicular tissue of different mammalian species. It is a straightforward protocol that combines mechanical testis dissociation, staining with Hoechst-33342 and propidium iodide, and FACS sorting, with wide applications in comparative studies of male reproductive biology. Biology Analysis of Cell Suspensions Isolated from Solid Tissues by Spectral Flow Cytometry Sandrine Schmutz1, Mariana Valente2,3,4,5, Ana Cumano2, Sophie Novault1 1Flow Cytometry Core Facility, Center for Translational Research-Technical Core, Institut Pasteur, 2Unit for Lymphopoiesis, Immunology Department, INSERM U1223, University Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Institut Pasteur, 3Stem-Cell Microenvironments in Repair/Regeneration Team, Instituto de Investigação e Inovação em Saúde (i3s), INEB - Instituto de Engenharia Biomédica, 4ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 5Stem Cells and Regenerative Medicine Team, UMRS 1166, ICAN - Institute of Cardiometabolism And Nutrition, UPMC - Université Pierre et Marie Curie - Paris 6, INSERM This article describes spectral cytometry, a new approach in flow cytometry that uses the shapes of emission spectra to distinguish fluorochromes. An algorithm replaces compensations and can treat auto-fluorescence as an independent parameter. This new approach allows for the proper analysis of cells isolated from solid organs.