Coleção de Artigos Acadêmicos

URI permanente para esta coleçãohttps://repositorio.insper.edu.br/handle/11224/3227

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Evaluation of artifacts produced by cannulated and solid-core screws using magnetic resonance imaging and computed tomography
(2026) Cassanego, Guilherme Rech; Rahal, Sheila Canevese; Santos, Tauan Silva Gouveia; Silva, Jeana Pereira da; Santos, Diogo Borges Renó dos; Mamprim, Maria Jaqueline; Carbonari, Marcelo José; Siqueira, Rafael Cerântola
This study aimed to evaluate, using both magnetic resonance imaging (MRI) and computed tomography (CT), the imaging artifacts associated with two types of titanium screws—cannulated and solid—from three different manufacturers, implanted in the canine humeral condyle. Three groups were established: G1 – 3.5 × 30 mm solid cortical screws and partially threaded cannulated screws; G2 – 3.5 × 28 mm solid cortical screws and 3.5 × 26 mm fully threaded conical compression cannulated screws; and G3 – 3.5 × 30 mm solid screws and 3.0 × 26 mm fully threaded conical compression cannulated screws. MRI evaluation was performed using SE DP/T2, Turbo 3D T1, STIR, and fast FLAIR sequences, while CT evaluation used transverse images. On MRI, solid screws produced more discrete and localized artifacts, mainly as peri-implant signal void/blooming with minimal geometric distortion and mild limitation of cortical and articular surface assessment. In contrast, cannulated screws generated larger areas of signal loss, especially in Turbo 3D T1 and fat-suppressed STIR/FLAIR sequences, although humeral condyle evaluation remained feasible. On CT, solid screws exhibited more pronounced metallic artifacts (beam hardening, streaks, mild blooming) compared with cannulated screws; however, these artifacts did not prevent assessment of peri-implant structures. Artifact measurements on MRI (Turbo 3D T1) and CT were higher for cannulated screws in G1 and G2, whereas in G3 solid screw produced greater artifact. In conclusion, both design and material composition of the screw significantly influence image quality, highlighting the importance of considering these factors when selecting the screw and planning imaging protocols.
Biomechanical comparison of three locking plate constructs for stabilization of a femoral segmental defect model in cats
(2026) Carbonari, Marcelo José; Coris, Jeniffer Gabriela Figueroa; Rahal, Sheila Canevese; Pereira, César Augusto M.; Cassanego, Guilherme Rech; Wei, Teng Hsiang; Caldeira, Fátima Maria C.
This study biomechanically evaluated three titanium locking plate constructs for stabilizing a segmental defect model that simulated a comminuted femoral shaft fracture in cats. Four groups were formed: G1 – single locking plate; G2 – plate-rod construct; G3 – dual plate in an orthogonal configuration; and G4 – intact bone. G1 used 16-hole locking plate with bicortical screws placed in holes 1, 3, 7, 10, 14, and 16. In G2, an intramedullary pin was included, with monocortical screws in the same positions. In G3, screws were placed as in G1, except that monocortical screws were used in holes 7 and 10. Additionally, an 8-hole plate was applied in orthogonal configuration, with monocortical screws placed in holes 1, 3, 6, and 8. All constructs underwent cyclic eccentric axial compression, followed by destructive testing, except G4, which was tested only destructively. During cyclic testing, stiffness did not differ between G2 and G3, while G1 exhibited lower stiffness. Deformation measured with Gauge 1 (16-hole plate) was greatest in G1, with no significant difference between G2 and G3. Deformation measured with Gauge 2 (intramedullary pin and orthogonal plate) was greater in G2 than in G3. In destructive testing, stiffness did not differ between G1 and G2, or between G2 and G3. Maximum force and displacement did not differ among Groups 1, 2 and 3. Group 4 differ from other groups for these variables. In conclusion, both the locking plate–rod construct and the dual titanium locking plate demonstrated similar stiffness, but locking plate–rod configuration exhibited greater deformation.
Who gets the Better Deal in Marriage? Examining Racial Differences in Brazilian Marriage Market
(2025) Duque, Daniel; França, Michael; Mendonca, Milena
This paper studies women’ marriage market in Brazil, investigating socioeconomic disparities and their trends in marriage outcomes. Relying on nationally representative data from the National Household Sample Survey (PNAD) covering 2002 to 2024, we analyze the association between marital status and these variables, as well as patterns of assortative mating by examining the educational and productivity pairing within couples. The results indicate that higher educational attainment among women is associated with a greater likelihood of being married, but, after accounting for education and age, black and mixed-race women continue to exhibit lower marriage rates relative to white counterparts. The analysis also reveals a strong persistence of educational assortment among spouses, but black and mixed-race women have lower quality husbands, even with sociodemographic controls, with non-consistent trends towards more or less inequality. We also show that a similar pattern arises across parental education, with black women from highly educated parents having lower marriage outcomes. Together, these findings advance the understanding of how economic sorting in the marriage market can reinforce broader patterns of racial and educational inequality in Brazil.
Subway expansion, job accessibility improvements, and home value appreciation in four global cities: Considering both local and network effects
(2022) Adriano Borges Costa; ADRIANO BORGES FERREIRA DA COSTA; Ramos, Camila; Zheng, Siqi
We explore the potential of incorporating accessibility analysis in addressing the impact of subway expansions on the real estate market. We first demonstrate that by using increases in accessibility to jobs as a continuous treatment variable, rather than adopting a binary station dummy approach, we achieve better goodness-of-fit in a quasiexperimental econometric analysis. Furthermore, accessibility measures allow the exploration of impacts beyond the local effects around new subway stations, shedding light on a network impact that has been largely overlooked to date. To increase the external validity of our findings, we apply the same analysis to the cities of Santiago (Chile), Sao Paulo (Brazil), Singapore, and Barcelona (Spain). and then explore the emergent patterns. We argue that the integration of urban economics and transportation analysis via the use of accessibility measures constitutes an innovation in the empirical approach commonly adopted in the literature. The use of such measures in causal empirical studies on transportation impacts can yield more robust and comprehensive results and capture nuanced spatial heterogeneity effects.
Exploring the causal effects of the built environment on travel behavior: a unique randomized experiment in Shanghai
(2022) Chen, Faan; ADRIANO BORGES FERREIRA DA COSTA
Experimental designs have been recognized as the gold standard for establishing causal mechanisms. However, the application of such designs is complicated by factors such as excessive costs, time consumption, ethical concerns, and political impossibility. Nevertheless, the Chinese government’s replacement housing efforts provide a unique randomized experiment for exploring the causal effects of the built environment on travel behavior. Accordingly, based on a large-scale survey on travel patterns under an experimental design in Shanghai, this study employs a two-step modeling approach, involving logit and Tobit models, to identify the built environment’s effects on auto ownership and vehicle kilometers traveled (VKT). We found that transit service improvements play a stronger role in reducing auto-drive than compact and diverse land-use characteristics. Increasing residential and employment density, as well as land-use mix, discourages car ownership, which in turn reduces VKT, but with lower elasticities than transportation system variables. The findings provide additional evidence and referential estimate for how land-use and transport strategies and policies designed to create a compact, mixed-use, and highly accessible built environment can be used in reducing auto driving. This study expands the VKT reduction elasticities’ database regarding the built environment across global spatial contexts, serving as a model for similar studies elsewhere in the world.
Rumo à COP30: a urgência de aterrissar e territorializar as negociações climáticas em Belém
(2025) Jacobi, Pedro Roberto; Machado, Hannah Arcuschin; Broetto, Valeriana Augusta; Corradi, Rodrigo
A COP30, a realizar-se em novembro em Belém, é vista como um momento decisivo diante da emergência climática. Em um contexto global de retrocessos ambientais, intensificação de conflitos armados e deslocamentos forçados, o Brasil assume papel de liderança sob desafios internos e externos. O artigo discute o cenário político e climático que antecede a conferência, destacando os entraves nacionais, regionais e internacionais que ameaçam a efetividade das negociações. Argumenta-se que, embora a COP30 não resolva todas as crises, ela representa uma oportunidade crítica para avançar com mais ambição e justiça climática.
Indicadores e capacidades institucionais na interseção saúde-ambiente: o índice de saúde ambiental infantojuvenil como dispositivo de ação pública intersetorial
(2025) Machado, Hannah Arcuschin; Menezes, Júlia Alves; Pedra, George Ulguim; Barros, Jocilene Dantas; Arcoverde, Gustavo Felipe Balué; Maluf Filho, Adalberto Felício; Guerra, Carlos Maurício da Fonseca; Ignotti, Eliane; Paula, Pedro do Carmo Baumgratz de; Moura, Danilo
O artigo apresenta o Índice de Saúde Ambiental Infantojuvenil enquanto ferramenta estratégica para fortalecer as políticas públicas de saúde e meio ambiente no Brasil. Em um contexto de desigualdades territoriais e exposições ambientais que afetam desproporcionalmente crianças e adolescentes, o índice oferece indicadores organizados em três dimensões – Exposição, Contexto e Saúde – permitindo identificar vulnerabilidades e orientar políticas públicas mais equitativas e integradas para cada um dos 5.570 municípios brasileiros. Detalha-se o processo metodológico de construção do índice, fundamentado em referências nacionais e internacionais, e validado por especialistas através do método Delphi. O índice se destaca pela compilação de dados de diversas fontes e pelo potencial de uso por gestores públicos e sociedade civil. Além disso, representa um dispositivo institucional que amplia capacidades estatais e articulações intersetoriais. Conclui-se que a iniciativa contribui para o enfrentamento das desigualdades socioambientais, promovendo uma ação pública orientada à população infantojuvenil e baseada em evidências.
A privacidade e o mercado de dados pessoais
(2016) Silveira, Sergio Amadeu; RODOLFO DA SILVA AVELINO; Souza, Joyce
O artigo apresenta a estrutura e a dinâmica do mercado de dados pessoais. Mostra a dimensão econômica do dado pessoal para a economia da informação. Apresenta as quatro camadas do mercado de dados: a coleta e armazenamento de informações; o processamento e a mineração de dados; a análise e a formação de amostras; e a modulação. Essas camadas se articulam e se misturam dependendo da organização das empresas que integram esse mercado. O artigo mostra ainda os elementos do mercado de dados no Brasil a partir de entrevistas realizadas com seus operadores. Por fim, indica a relevância do direito à privacidade para impor limites às atividades da economia da interceptação de dados.
Analytical definitions of connectivity, incidence and node matrices for t-struts tensegrity prisms
(2024) Paiva, Victor A.S.M.; Kurka, Paulo R.G.; Izuka, Jaime H.
Regular tensegrity prism modules are widely used by researchers. Numerous research articles combine them to form grids and towers under various assembly strategies. Most of them define connectivity and node matrices that satisfy their structures as a whole, but a general definition for the basic modules has not been formally reported. This paper formalizes sets of definitions for the connectivity, incidence, and node matrices that are valid for any tensegrity prism formed by four struts or more. The definitions are based on geometry and provide simple and general formulations by applying floor and ceiling operators. Both clockwise and counterclockwise rotated modules are covered.
Beyond the Agreement: Dilemmas in Contracting for the Transfer of Management Practices
(2022) SANDRO CABRAL; SERGIO GIOVANETTI LAZZARINI; Domingos, Fernando Deodato; RICARDO PAES DE BARROS

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