Validation of Subject Specific Computed Tomography-based Finite Element Models of the Human Proximal Tibia using Full-field Experimental Displacement Measurements from Digital Volume Correlation

Quantitative computed tomography-based finite element (QCT-FE) modeling is a computational tool for predicting bone’s response to applied load, and is used by musculoskeletal researchers to better understand bone mechanics and their role in joint health. Decisions made at the modeling stage, such as the method for assigning material properties, can dictate model accuracy. Predictions of surface strains/stiffness from QCT-FE models of the proximal tibia have been validated against experiment, yet it is unclear whether these models accurately predict internal bone mechanics (displacement). Digital volume correlation (DVC) can measure internal bone displacements and has been used to validate FE models of bone; though, its use has been limited to small specimens. The objectives of this study were to 1) establish a methodology for high-resolution peripheral QCT (HR-pQCT) scan acquisition and image processing resulting in low DVC displacement measurement error in long human bones, and 2) apply different density-modulus relationships and material models from the literature to QCT-FE models of the proximal tibia and identify those approaches which best predicted experimentally measured internal bone displacements and related external reaction forces, with highest explained variance and least error. Using a modified protocol for HR-pQCT, DVC displacement errors for large scan volumes were less than 19μm (0.5 voxels). Specific trabecular and cortical models from the literature were identified which resulted in the most accurate QCT-FE predictions of internal displacements (RMSE%=3.9%, R2>0.98) and reaction forces (RMSE%=12.2%, R2=0.78). This study is the first study to quantify experimental displacements inside a long human bone using DVC. It is also the first study to assess the accuracy of QCT-FE predicted internal displacements in the tibia. Our results indicate that QCT-FE models of the tibia offer reasonably accurate predictions of internal bone displacements and reaction forces for use in studying bone mechanics and joint health

Oral capecitabine as an alternative to i.v. 5-fluorouracil-based adjuvant therapy for colon cancer: safety results of a randomized, phase III trial

Background: Oral capecitabine achieves a superior response rate with an improved safety profile compared with bolus 5-fluorouracil-leucovorin (5-FU/LV) as first-line treatment for patients with metastatic colorectal cancer. We report here the results of a large phase III trial investigating adjuvant oral capecitabine compared with 5-FU/LV (Mayo Clinic regimen) in Dukes' C colon cancer. Patients and methods: Patients aged 18-75 years with resected Dukes' C colon carcinoma were randomized to receive 24 weeks of treatment with either oral capecitabine 1250 mg/m2 twice daily, days 1-14 every 21 days (n = 993), or i.v. bolus 5-FU 425 mg/m2 with i.v. leucovorin 20 mg/m2 on days 1-5, repeated every 28 days (n = 974). Results: Patients receiving capecitabine experienced significantly (P <0.001) less diarrhea, stomatitis, nausea/vomiting, alopecia and neutropenia, but more hand-foot syndrome than those receiving 5-FU/LV. Fewer patients receiving capecitabine experienced grade 3 or 4 neutropenia, febrile neutropenia/sepsis and stomatitis (P <0.001), although more experienced grade 3 hand-foot syndrome than those treated with 5-FU/LV (P <0.001). Capecitabine demonstrates a similar, favorable safety profile in patients aged <65 years or ≥65 years old. Conclusions: Based on its improved safety profile, capecitabine has the potential to replace 5-FU/LV as standard adjuvant treatment for patients with colon cancer. Efficacy results are expected to be available in 2004. Keywords: Adjuvant treatment, capecitabine, chemotherapy, colorectal cance

Depth concentrations of deuterium ions implanted into some pure metals and alloys

Pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd-alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25 keV deuterium ions at fluences in the range (1.2{\div}2.3)x1022 D+/m2. The post-treatment depth distributions of deuterium ions were measured 10 days and three months after the implantation using Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS). Comparison of the obtained results allowed to make conclusions about relative stability of deuterium and hydrogen gases in pure metals and diluted Pd alloys. Very high diffusion rates of implanted deuterium ions from V and Pd pure metals and Pd alloys were observed. Small-angle X-ray scattering revealed formation of nanosized defects in implanted corundum and titanium.Comment: 12 pages, 9 figure

Efeitos De Variações Sazonais E Métodos De Coleta Sobre A Composição Mineral De Própolis De Colmeias De Apis Mellifera Linnaeus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The effects of seasonal variations and the methods of collection of propolis produced by Africanized honey bees Apis mellifera Linnaeus, 1758, on the composition of constituent minerals such as magnesium (Mg), zinc (Zn), iron (Fe), sodium (Na), calcium (Ca), copper (Cu), and potassium (K) were evaluated. Propolis was harvested from 25 beehives by scraping or by means of propolis collectors (screen, “intelligent” collector propolis [ICP], lateral opening of the super [LOS], and underlay method). During the one-year study, the propolis produced was harvested each month, ground, homogenized, and stored in a freezer at -10 ºC. Seasonal analyses of the mineral composition were carried out by atomic absorption spectrophotometry and the results were evaluated by analysis of variance (ANOVA), followed by Tukey-Kramer’s test to compare the mean values (p<0.05). The results showed that seasonal variations influence the contents of 5 minerals (Mg, Fe, Na, Ca, and Cu), and the propolis harvesting method affects the contents of 4 minerals (Mg, Zn, Fe, and Ca). © 2016, Instituto Internacional de Ecologia. All rights reserved.762396401CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

HISTÓRIA E HISTORIOGRAFIA DA EDUCAÇÃO NO ESTADO DO PARANÁ: TRAJETÓRIAS E PERSPECTIVAS

Review of the book: ORLANDO, Evelyn de Almeida; MACHADO JR., Cláudio de Sá (Orgs.). História da Educação no Paraná: caminhos da pesquisa e do ensino. Porto Alegre, RS: Editora Fi, 2020. &nbsp;Reseña del libro: ORLANDO, Evelyn de Almeida; MACHADO JR., Cláudio de Sá (Orgs.). História da Educação no Paraná: caminhos da pesquisa e do ensino. Porto Alegre, RS: Editora Fi, 2020.Resenha da obra: ORLANDO, Evelyn de Almeida; MACHADO JR., Cláudio de Sá (Orgs.). História da Educação no Paraná: caminhos da pesquisa e do ensino. Porto Alegre, RS: Editora Fi, 2020

Hydrology of the Colorado Tailings Area, Butte, MT

During the past 7 to 8 years, the Colorado Tailings have been the site of numerous studies on potential heavy metal contribution to Silver Bow Creek (SBC). Three years ago the Montana Department of State Lands-Abandoned Mine Lands Bureau (DSL-AML) initiated, through the Montana Bureau of Mines and Geology (MBMG), a study of reclamation and removal alternatives for this site. Since that time the tailings have received increased interest with the placement of SBC on the Environmental. Protection Agency\u27s Superfund. Numerous studies predate the ongoing Superfund and MBMG studies, with contradictory results. Loading rates in SBC have been reported to vary from 0 to 36 lb/day for copper and 300 to 320 lb/day for zinc from above to below the tailings (4). Since the initiation of the MBMG study, numerous changes have taken place upstream which complicate comparisons with historic data; those being the Anaconda Minerals Company zero discharge for the Weed Concentrator and the suspension of mining in Butte. Results from the MBMG study show a substantial degradation of ground water quality from outside (upgradient) of the tailings through the tailings, as do surface water results, but to a lesser degree, from above to below the tailings.

Evaluation of Motor Changes and Toxicity of Insecticides Fipronil and Imidacloprid in Africanized Honey Bees (Hymenoptera: Apidae)

Honey bees are important pollinators and are essential in beekeeping. Honey bees get exposed to systemic pesticides while foraging in contaminated fields, and it is important to know the toxicity (LD50) and evaluate the impacts of bees’ exposure to these molecules. Fipronil and imidacloprid are systemic pesticides widely used in Brazil and other countries. The objective of this study was to determine the LD50 (24 hours) and evaluate motor changes in Africanized honey bee foragers exposed to lethal and sublethal doses of fipronil and imidacloprid. To determine the LD50, foraging honey bees were exposed by ingestion and contact to five doses of fipronil (Regent 800WG®) and imidacloprid (Appalus 200SC®) insecticides. After 24 hours of exposure, the number of dead bees was counted, and the results were subjected to probit analysis. The motor activity of bees exposed by ingestion or contact to LD50 and sublethal doses (1/500th of the LD50) of both pesticides was assessed 4 hours after exposure using a behavioral observation box. The ingestion and contact with LD50 of fipronil were 0.0528±0.0090 and 0.0054±0.0041 μg/bee, respectively; the ingestion and contact with LD50 of imidacloprid were 0.0809±0.0135 and 0.0626±0.0080 μg/bee, respectively. Bees exposed to lethal and sublethal doses of both insecticides experienced significant motor alterations compared to the control, except for exposure to sublethal doses of fipronil by contact. Fipronil and imidacloprid are highly toxic and promote motor changes in bees. Thus, it is important to establish management methods to reduce pollinators’ exposure to these pesticides

Investigação de mecanismos da determinação e da diferenciação sexual dependente de temperatura em zebrafish (Danio rerio) e em duas espécies de tartarugas marinhas (Caretta caretta e Eretmochelys imbricata)

Os mecanismos de determinação sexual variam grandemente entre grupos de animais vertebrados. As tartarugas marinhas possuem a determinação sexual dependente da temperatura, sendo que, ao longo do tempo de incubação dos ovos, há o período termossensitivo no qual ocorre a diferenciação das gônadas. Assim como as tartarugas, alguns peixes também apresentam este tipo de determinação, sendo o zebrafish (Danio rerio) um modelo animal usado em diversas pesquisas em diferentes áreas que, apesar do amplo uso, ainda não possui as condições e mecanismos de diferenciação sexual totalmente elucidados. Além da temperatura, fatores genéticos e ambientais também podem atuar na diferenciação sexual nestas espécies. Esta dissertação teve duas etapas. Na primeira etapa foram padronizadas as técnicas de investigação do mecanismo de determinação sexual dependente da temperatura em zebrafish. Os resultados demonstram que o zebrafish passa primeiramente por uma fase de hermafroditismo juvenil antes da diferenciação sexual. A exposição a temperaturas controladas (24°C, 26°C, 28°C e 30°C) durante o período de desenvolvimento inicial induziu alterações nas taxas de eclosão e sobrevivência ao longo de 7 dias pós-fertilização, avaliados a partir de 4 horas pós-fertilização, bem como batimentos cardíacos de embriões com 24 e 48 horas pós-fertilização. Análises histológicas das gônadas demonstraram que as diferentes temperaturas avaliadas podem atrasar ou acelerar o processo de desenvolvimento sexual durante a fase inicial em relação aos animais mantidos à 28oC. Análises da proporção sexual demonstraram que temperaturas intermediárias (26 e 28°C) podem favorecer o desenvolvimento de uma maior proporção de machos. A segunda etapa teve como objetivo investigar aspectos do desenvolvimento sexual de duas espécies de tartarugas marinhas (Caretta caretta e Eretmochelys imbricata) a fim de contribuir para o entendimento dos mecanismos de determinação e diferenciação sexual e o estabelecimento de métodos que permitam a sexagem dos mesmos em distintas fases do desenvolvimento de forma mais prática e menos invasiva do que as utilizadas atualmente. Tartarugas marinhas filhotes ao nascerem já apresentam o sexo definido, tendo o grau de desenvolvimento diferente entre as espécies Caretta caretta e Eretmochelys imbricata, provavelmente devido ao menor tempo de incubação de C.caretta. Com a padronização das técnicas de ELISA foi demonstrado que kits para avaliação de hormônios sexuais humanos podem ser utilizados para quantificação de hormônios tanto para zebrafish quanto tartarugas marinhas. As análises da expressão de genes envolvidos no processo de diferenciação sexual estão em andamento.Mechanisms of sexual determination vary greatly among vertebrates. Sea turtles show temperature dependent sex determination with a thermosensitive period during egg incubation in which the gonad differentiation occurs. Like turtles, some fish also are temperature sensitive. Zebrafish (Danio rerio) is an animal model used in several areas of biomedical research that, despite its widespread use, whose sexual differentiation conditions and mechanisms are not fully elucidated. In addition to temperature, genetic and environmental factors may also play a role in the sexual differentiation of these species. This dissertation had two parts. In the first, the techniques for investigating the sex-dependent mechanism of sexual determination in zebrafish were standardized. Our results demonstrate that zebrafish first undergoes a stage of juvenile hermaphroditism prior to sexual differentiation. Exposure to controlled temperatures (24 ° C, 26 ° C, 28 ° C or 30 °C) during the initial developmental period starting at 4 hours post fertilization (hpf) significantly influenced hatching and survival rates over the first 7 days postfertilization (dpf). Embryonic heart rate at 24 and 48 hours post-fertilization were also impacted. Histological analyzes of the gonads demonstrated that different temperatures evaluated may delay or accelerate the process of sexual development during the initial phase compared to animals kept at 28°C. Analysis of the sex ratio has shown that intermediate temperatures (26 and 28 ° C) may favor the development of more males. The second part of this study aimed to investigate aspects of the sexual development of two species of sea turtles (Caretta caretta and Eretmochelys imbricata) in order to contribute to the understanding of the mechanisms of sexual determination and differentiation and the establishment of methods that allow the sexing of the same in phases of development in a more practical and less invasive way than those currently used. Sea turtles born to cubs already have the defined sex, having a different degree of development between the species Caretta caretta and Eretmochelys imbricata, probably due to the shorter incubation time of C.caretta. With the standardization of ELISA techniques, it has been shown that kits for the evaluation of human sex hormones can be used to quantify hormones for both zebrafish and sea turtles. Analysis of the expression of genes involved in the process of sexual differentiation is under way

Impressos, discursos e moralidade nos regimes autoritários instituídos no Brasil

Resenha da obra:COWAN, Benjamin A. Securing sex: morality and repression in the making of Cold War Brazil. Chapel Hill, NC: University of North Carolina Press, 2016