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Your search keyword '"Freitas, João P."' showing total 11 results
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11 results on '"Freitas, João P."'

1. Regression models for binary data with scale mixtures of centered skew-normal link functions

Author

de Freitas, João Victor B. and Azevedo, Caio L. N.

Subjects
Statistics - Methodology
Abstract

For the binary regression, the use of symmetrical link functions are not appropriate when we have evidence that the probability of success increases at a different rate than decreases. In these cases, the use of link functions based on the cumulative distribution function of a skewed and heavy tailed distribution can be useful. The most popular choice is some scale mixtures of skew-normal distribution. This family of distributions can have some identifiability problems, caused by the so-called direct parameterization. Also, in the binary modeling with skewed link functions, we can have another identifiability problem caused by the presence of the intercept and the skewness parameter. To circumvent these issues, in this work we proposed link functions based on the scale mixtures of skew-normal distributions under the centered parameterization. Furthermore, we proposed to fix the sign of the skewness parameter, which is a new perspective in the literature to deal with the identifiability problem in skewed link functions. Bayesian inference using MCMC algorithms and residual analysis are developed. Simulation studies are performed to evaluate the performance of the model. Also, the methodology is applied in a heart disease data.

Published
2024

2. Bayesian inference for scale mixtures of skew-normal linear models under the centered parameterization

Author

de Freitas, João Victor B. and Azevedo, Caio L. N.

Subjects
Statistics - Methodology
Abstract

In many situations we are interested in modeling real data where the response distribution, even conditionally on the covariates, presents asymmetry and/or heavy/light tails. In these situations, it is more suitable to consider models based on the skewed and/or heavy/light tailed distributions, such as the class of scale mixtures of skew-normal distributions. The classical parameterization of this distributions may not be good due to the some inferential issues when the skewness parameter is in a neighborhood of 0, then, the centered parameterization becomes more appropriate. In this paper, we developed a class of scale mixtures of skew-normal distributions under the centered parameterization, also a linear regression model based on them was proposed. We explore a hierarchical representation and set up a MCMC scheme for parameter estimation. Furthermore, we developed residuals and influence analysis tools. A Monte Carlo experiment is conducted to evaluate the performance of the MCMC algorithm and the behavior of the residual distribution. The methodology is illustrated with the analysis of a real data set.

Published
2024

5. Effect of Asymptomatic and Symptomatic COVID-19 on Acute Ischemic Stroke Revascularization Outcomes

Author

Strambo, Davide, Marto, João Pedro, Ntaios, George, Nguyen, Thanh N., Michel, Patrik, Herzig, Roman, Członkowksa, Anna, Demeestere, Jelle, Yassin Mansour, Ossama, Georgiopoulos, Georgios, Nogueira, Raul G., Salerno, Alexander, Wegener, Susanne, Baumgartner, Philipp, Cereda, Carlo W., Bianco, Giovanni, Beyeler, Morin, Arnold, Marcel, Carrera, Emmanuel, Machi, Paolo, Altersberger, Valerian, Bonati, Leo, Gensicke, Henrik, Bolognese, Manuel, Peters, Nils, Wetzel, Stephan, Magriço, Marta, Nuno Ramos, João, Sargento-Freitas, João, Machado, Rita, Maia, Carolina, Machado, Egídio, Paiva-Nunes, Ana, Ferreira, Patrícia, Pinho-e-Melo, Teresa, Carvalho-Dias, Mariana, Paula, André, Alberto Correia, Manuel, Castro, Pedro, Azevedo, Elsa, Albuquerque, Luís, Nuno-Alves, José, Ferreira-Pinto, Joana, Meira, Torcato, Pereira, Liliana, Rodrigues, Miguel, Araújo, André, Rodrigues, Marta, Rocha, Mariana, Pereira-Fonseca, Ângelo, Ribeiro, Luís, Varela, Ricardo, Cappellari, Manuel, Zivelonghi, Cecilia, Sajeva, Giulia, Zini, Andrea, Gentile, Mauro, Forlivesi, Stefano, Migliaccio, Ludovica, Sessa, Maria, Pezzini, Alessandro, Sangalli, Davide, Zedde, Marialuisa, Pascarella, Rosario, Diamanti, Susanna, Beretta, Simone, Schwarz, Ghil, Frisullo, Giovanni, Marcheselli, Simona, Seners, Pierre, Sabben, Candice, Escalard, Simon, Piotin, Michel, Maier, Benjamin, Charbonnier, Guillaume, Vuillier, Fabrice, Legris, Loic, Cuisenier, Pauline, Vodret, Francesca R., Marnat, Gaultier, Liegey, Jean-Sebastien, Sibon, Igor, Flottmann, Fabian, Broocks, Gabriel, Gloyer, Nils-Ole, Bohmann, Ferdinand O., Hendrik Schaefer, Jan, Nolte, Christian H., Audebert, Heinrich, Siebert, Eberhard, Sykora, Marek, Lang, Wilfried, Ferrari, Julia, Mayer-Suess, Lukas, Knoflach, Michael, Gizewski, Elke-Ruth, Stolp, Jeffrey, Stolze, Lotte J., Coutinho, Jonathan M., Nederkoorn, Paul J., van-den-Wijngaard, Ido, de Meris, Joke, Lemmens, Robin, De Raedt, Sylvie, Vandervorst, Fenne, Pierre Rutgers, Matthieu, Guilmot, Antoine, Dusart, Anne, Bellante, Flavio, Calleja-Castaño, Patricia, Ostos, Fernando, Gonzalez-Ortega, Guillermo, Martín-Jiménez, Paloma, García-Madrona, Sebastian, Cruz-Culebras, Antonio, Vera, Rocio, Matute, Maria-Consuelo, Fuentes, Blanca, Alonso-de-Leciñana, María, Rigual, Ricardo, Díez-Tejedor, Exuperio, Pérez-Sánchez, Soledad, Montaner, Joan, Díaz-Otero, Fernando, Perez de la Ossa, Natalia, Flores-Pina, Belén, Muñoz-Narbona, Lucia, Chamorro, Angel, Rodríguez-Vázquez, Alejandro, Renú, Arturo, Ayo-Martin, Oscar, Hernandez-Fernandez, Francisco, Segura, Tomas, Tejada-Meza, Herbert, Hlaing, Thant, See, Isaiah, Simister, Robert, Werring, David J., Saxhaug Kristoffersen, Espen, Nordanstig, Annika, Jood, Katarina, Rentzos, Alexandros, Šimůnek, Libor, Krajíčková, Dagmar, Krajina, Antonín, Mikulík, Robert, Cviková, Martina, Vinklárek, Jan, Školoudík, David, Roubec, Martin, Hurtikova, Eva, Hrubý, Rostislav, Ostry, Svatopluk, Skoda, Ondrej, Pernicka, Marek, Kočí, Lubomír, Eichlová, Zuzana, Jíra, Martin, Kovář, Martin, Panský, Michal, Mencl, Pavel, Paloušková, Hana, Tomek, Aleš, Janský, Petr, Olšerová, Anna, Šrámek, Martin, Havlíček, Roman, Malý, Petr, Trakal, Lukáš, Fiksa, Jan, Slovák, Matěj, Karliński, Michał, Nowak, Maciej, Sienkiewicz-Jarosz, Halina, Bochynska, Anna, Wrona, Pawel, Homa, Tomasz, Sawczynska, Katarzyna, Slowik, Agnieszka, Wlodarczyk, Ewa, Wiącek, Marcin, Tomaszewska-Lampart, Izabella, Sieczkowski, Bartosz, Bartosik-Psujek, Halina, Bilik, Marta, Bandzarewicz, Anna, Dorobek, Malgorzata, Zielińska-Turek, Justyna, Nowakowska-Kotas, Marta, Obara, Krystian, Urbanowski, Paweł, Budrewicz, Sławomir, Guziński, Maciej, Świtońska, Milena, Rutkowska, Iwona, Sobieszak-Skura, Paulina, Łabuz-Roszak, Beata, Dębiec, Aleksander, Staszewski, Jacek, Stępień, Adam, Zwiernik, Jacek, Wasilewski, Grzegorz, Tiu, Cristina, Terecoasă, Elena-Oana, Radu, Razvan-Alexandru, Negrila, Anca, Dorobat, Bogdan, Panea, Cristina, Tiu, Vlad, Petrescu, Simona, Özcan-Özdemir, Atilla, Mahmoud, Mostafa, El-Samahy, Hussam, Abdelkhalek, Hazem, Al-Hashel, Jasem, Ibrahim Ismail, Ismail, Salmeen, Athari, Ghoreishi, Abdoreza, Sabetay, Sergiu, Gross, Hana, Klein, Piers, Abdalkader, Mohamad, Jabbour, Pascal, El Naamani, Kareem, Tjoumakaris, Stavropoula, Abbas, Rawad, Mohamed, Ghada-A., Chebl, Alex, Min, Jiangyong, Hovingh, Majesta, Tsai, Jenny, Khan, Muhib-A., Nalleballe, Krishna, Onteddu, Sanjeeva, Masoud, Hesham E., Michael, Mina, Kaur, Navreet, Maali, Laith, Abraham, Michael, Khandelwal, Priyank, Bach, Ivo, Ong, Melody, Babici, Denis, Khawaja, Ayaz-M., Hakemi, Maryam, Rajamani, Kumar, Cano-Nigenda, Vanessa, Arauz, Antonio, Amaya, Pablo, Llanos, Natalia, Arango, Akemi, Vences, Miguel A., Barrientos, José-Domingo, Caetano, Rayllene, Targa, Rodrigo, Scollo, Sergio, Yalung, Patrick, Nagendra, Shashank, Gaikwad, Abhijit, and Seo, Kwon-Duk

Published
2024
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7. Comparison of bone mineral density between female amateur triathletes and nonathletes: A cross-sectional study

Author

Cruz Correa Netto Soares, Guilherme, Barbosa Junior, José Geraldo Gomes, Seffrin, Aldo, Vivan, Lavínia, Rosa de Freitas, João Victor, Costa, Gustavo De Conti Teixeita, de Lira, Claudio André Barbosa B, Vancini, Rodrigo Luiz, Weiss, Katja, Knechtle, Beat, and Andrade, Marilia Santos

Abstract

Purpose: Physical inactivity is considered an important risk factor for osteoporosis, however, some athletes performing extremely high training volumes can also develop bone mass loss. Moreover, the effect of total body mass or body surface area on bone mineral density remains controversial. Therefore, the aim of this study was to compare the absolute bone mineral density and bone mineral density adjusted to body surface area between amateur triathletes and nonactive women.Methods: Forty-two healthy women (23 amateur triathletes and 19 nonactive individuals) were evaluated for body composition using a dual-energy X-ray absorptiometry system.Results: Compared to nonactive women, amateur triathletes exhibited lower body mass index (p < 0.001), lower bone mineral density (p < 0.001), and body surface area (p < 0.001). However, bone mineral density adjusted by body surface area in the triathletes was higher than in the nonactive women (p = 0.03).Conclusion: These findings showed that amateur triathles presented lower absolute bone mineral density, but higher bone mineral density adjusted to body surface area. Future studies are recommended to identify if the higher bone mineral density adjusted to body surface area are associated with a lower bone fragility.

Published
2024
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9. Acute management of cerebral venous thrombosis: Indications, technique, and outcome of endovascular treatment in two high-volume centers

Author

Sousa, João André, Achutegui, Maider Iza, Juega-Mariño, Jesus, Requena, Manuel, Bernardo-Castro, Sara, Rodrigo-Gisbert, Marc, Rizzo, Federica, Olivé, Marta, Garcia-Tornel, Álvaro, Chaves, Ana Carolina, Rodriguez-Villatoro, Noelia, Muchada, Marian, Pagola, Jorge, Rodriguez-Luna, David, Rubiera, Marta, Martins, Ana Inês, Silva, Fernando, Veiga, Ricardo, Nunes, Cesar, Machado, Egídio, Diana, Francesco, de Dios, Marta, Hernández, David, Ribo, Marc, Molina, Carlos, Sargento-Freitas, João, and Tomasello, Alejandro

Abstract

Introduction After several uncontrolled studies and one randomized clinical trial, there is still uncertainty regarding the role of endovascular treatment (EVT) in cerebral venous thrombosis (CVT). This study aims to describe and assess different acute management strategies in the treatment of CVT.Methods We performed a retrospective analysis of an international two-center registry of CVT patients admitted since 2019. Good outcome was defined as a return to baseline modified Rankin scale at three months. We described and compared EVT versus no-EVT patients.Results We included 61 patients. Only one did not receive systemic anticoagulation. EVT was performed in 13/61 (20%) of the cases, with a median time from diagnosis to puncture of 4.5 h (1.25–28.5). EVT patients had a higher median baseline NIHSS [6 (IQR 2–17) vs 0 (0–2.7), p= 0.002)] and a higher incidence of intracerebral hemorrhage (53.8% vs 20.3%, p= 0.03). Recanalization was achieved in 10/13 (77%) patients. Thrombectomy was performed in every case with angioplasty in 7 out of 12 patients and stenting in 3 cases. No postprocedural complication was reported. An improvement of the median NIHSS from baseline to discharge [6 (2–17) vs 1(0–3.75); p< 0.001] was observed in EVT group. A total of 31/60 patients (50.8%) had good outcomes. Adjusting to NIHSS and ICH, EVT had a non-significant increase in the odds of a good outcome [aOR 1.42 (95%CI 0.73–2.8, p= 0.307)].Conclusions EVT in combination with anticoagulation was safe in acute treatment of CVT as suggested by NIHSS improvement. Selected patients may benefit from this treatment.

Published
2024
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11. Tratamento de fraturas patológicas tumorais diafisárias do úmero com haste intramedular rígida bloqueada estática – Experiência de 22 anos

Author

Moura, Diogo Lino, Alves, Filipe, Fonseca, Rúben, Freitas, João, and Casanova, José

Abstract

Estudo retrospetivo observacional em pacientes submetidos à fixação com haste intramedular de fratura patológica tumoral consumada ou iminente da diáfise do úmero em contexto de doença tumoral disseminada ao longo de 22 anos na mesma instituição.

Published
2024
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