TOMADA DE DECISÃO E RISCO: A CONTRIBUIÇÃO DOS MATEMÁTICOS E ESTATÍSTICOS

No passado  para tomar decisões frente à incerteza do futuro, os seres humanos consultavam os oráculos, os céus e até vísceras de animais. Entretanto, com o passar dos anos, cientistas de várias áreas, principalmente da matemática e estatística, realizaram muitos estudos, demonstrando que a incerteza poderia ser medida através do cálculo de probabilidades anteriormente desconhecidas de fatos empíricos da realidade.  As pessoas começaram a perceber então, que o futuro não era apenas um capricho dos deuses e que os homens não teriam de ser passíveis perante a natureza. Dessa forma, as ciências da matemática e da probabilidade contribuíram de maneira significativa para o estudo sobre tomada de decisão e risco. Sendo assim, o principal objetivo do presente artigo é apresentar as contribuições de alguns matemáticos e estatísticos para a compreensão do risco e o processo de tomada de decisão

The effect of loss aversion and entitlement on cheating: An online experiment

We investigate how loss aversion and entitlement influence lying. We conduct an online experiment with a cheating task in which participants draw and report a number. Participants can cheat by reporting a different number to earn a higher payoff. We vary whether participants perform (or not) a real effort task to generate their endowment before the cheating task to evoke a sense of entitlement, and whether participants can cheat for an additional gain or to avoid a loss using a 2 (earned/not earned endowment) × 2 (loss/gain) design. We find no effect of loss aversion on cheating and only weak evidence of a prior stage of real effort on lying behavior. Furthermore, we find a correlation between real effort task performance and lying, but only in the gain domain. This is the first study to look at how entitlement affects cheating behavior in both the gain and loss domains

Coordination of student teams focused on project management processes

Engineering learning processes are expected to develop technical and transversal competencies on students that are demanded by the engineering professional bodies. The need for the development of competencies raised an incremental interest in applying innovative approaches in Engineering education. One of the methodologies used in this context is Project-Based Learning (PBL). At the University of Brasilia, a course degree in Production Engineering was created having as a main reference the Project-Based Learning (PBL) approach. The use of PBL implies a change of behavior of teachers who play a main role of facilitators of competencies development, and of the students, who learn in a collaborative way, working with others in teams. Students’ working in team and developing a project during a semester will require effective coordination models. The objective of this paper is to propose a model of coordination among students’ teams based on project management knowledge. Furthermore, a qualitative approach is applied to evaluate the application of this model during one semester. The results show that a coordination model for student teams developing projects is important to support their learning process, which is not solely dependent on students, as teachers/tutors have an important role before, during and at the end of the project. The tutor is especially important, as he/she is responsible for supporting the teams in several project management dimensions. This is an essential support for students to know how to manage the team, communicate, define goals, carry out the activities on time, plan the milestones and understand the impact of their decisions. These competencies are also part of student learning and are an important part of engineering education

Effect of photobiomodulation on the viability of osteoblasts and fibroblasts submitted to alendronate sodium or zoledronic acid: an in vitro study

O objetivo deste estudo é avaliar o efeito da terapia de fotobiomodulação (TFBM) na viabilidade de osteoblastos e cultura de fibroblastos em diferentes concentrações de alendronato ou ácido zoledrônico. Duas linhagens celulares – células de camundongos semelhantes a osteoblastos (OSTEO 1) e fibroblastos de mucosa bucal humana (FMM1) – foram utilizadas. As células foram submetidas a diferentes concentrações de bisfosfonatos (1 μM, 10 μM e 100 μM de alendronato de sódio e 3 μM, 5 μM e 10 μM de ácido zoledrônico) por 24 horas. Em seguida, as culturas receberam TFBM. As irradiações foram aplicadas com laser de diodo (InGaAIP, 660 nm, 30 mW, spot 0,028 cm2) em modo contínuo, pontual e de contato, em duas densidades de energia: 5 J/cm2 (4,5 s) ou 10 J/cm2 (9s) com intervalos de 6 horas. A viabilidade celular foi determinada pelo ensaio de atividade mitocondrial (MTT) 24 h após a última irradiação. Os dados foram comparados pelo ANOVA One-Way, complementado pelo teste de Tukey (p < 0,05). O alendronato de sódio nas concentrações de 100 μM e 10 μM e o ácido zoledrônico na concentração de 10 μM apresentaram maior toxicidade a longo prazo. A viabilidade celular do grupo tratado com TFBM foi significativamente maior que a do grupo de controle negativo. O mesmo ocorreu com os osteoblastos tratados com as maiores concentrações do fármaco (5 e 10 μM), apesar de não atingir a viabilidade celular do grupo de controle positivo, apresentou maior viabilidade do que o controle negativo no qual as células não foram irradiadas. Nos grupos submetidos ao ácido zoledrônico, controles positivos apresentaram maior viabilidade celular. Concluímos que sob os parâmetros aplicados neste estudo, a TFBM, com uma densidade de energia de 5 J/cm2, foi capaz de reverter a toxicidade do alendronato sódico aplicado nas concentrações mais altas em ambos os tipos celulares, enquanto a toxicidade do ácido zoledrônico, independentemente de suas concentrações, foi não influenciada pela TFBM.The goal of this study is to evaluate the effect of photobiomodulation therapy (PBMT) on the viability of osteoblasts and cultured fibroblasts in different concentrations of alendronate or zoledronic acid. Two cell lines: osteoblast-like mouse cells (OSTEO 1) and human buccal mucosa fibroblast (FMM1) were used. Cells were submitted to different concentrations of bisphosphonates (1 μM, 10 μM, and 100 μM sodium alendronate and 3 μM, 5 μM and 10 μM zoledronic acid) for 24 hours. Next, the cultures received PBMT. The irradiations were applied with a diode laser (InGaAIP, 660 nm, 30 mW, spot 0.028 cm2) in continuous, punctual and contact mode at two energy densities: 5 J/cm2 (4.5 s) or 10 Jcm2 (9s) with 6 hours-intervals. Cell viability was determined by mitochondrial activity assay (MTT) 24 h after the last irradiation. The data were compared by the one way- ANOVA, complemented by the Tukey’s test (p < 0.05). Sodium alendronate at concentrations of 100 μM and 10 μM and zoledronic acid at 10 μM concentration showed higher long-term toxicity. The cellular viability of the PBMT treated group was significantly higher than that of the negative control group. The same occurred with the osteoblasts treated with the highest concentrations of the drug (5 and 10 μM), despite not reaching the cell viability of the positive control group, it presented greater viability than the negative control where the cells were not irradiated. In the groups submitted to zoledronic acid, positive controls presented greater cell viability. We concluded that under the parameters applied in this study, PBMT at an energy density of 5 J/cm2 was able to revert the toxicity of sodium alendronate applied at the higher concentrations in both cell types, whereas zoledronic acid toxicity, regardless of its concentrations, was not influenced by PBMT

TOMADA DE DECISÃO E RISCO: A CONTRIBUIÇÃO DOS MATEMÁTICOS E ESTATÍSTICOS

No passado  para tomar decisões frente à incerteza do futuro, os seres humanos consultavam os oráculos, os céus e até vísceras de animais. Entretanto, com o passar dos anos, cientistas de várias áreas, principalmente da matemática e estatística, realizaram muitos estudos, demonstrando que a incerteza poderia ser medida através do cálculo de probabilidades anteriormente desconhecidas de fatos empíricos da realidade.  As pessoas começaram a perceber então, que o futuro não era apenas um capricho dos deuses e que os homens não teriam de ser passíveis perante a natureza. Dessa forma, as ciências da matemática e da probabilidade contribuíram de maneira significativa para o estudo sobre tomada de decisão e risco. Sendo assim, o principal objetivo do presente artigo é apresentar as contribuições de alguns matemáticos e estatísticos para a compreensão do risco e o processo de tomada de decisão

Reclassification and treatment of odontogenic keratocysts: A cohort study

<div><p>Abstract: The odontogenic keratocyst (OKC) is a recurrent cyst that has been recently reclassified from an odontogenic tumor to an odontogenic cyst. The aim of the present study was to investigate its treatment and address issues related to its association with nevoid basal cell carcinoma syndrome (NBCCS). Lesions from the cohort of patients included in the present study consisted of 40 OKCs, of which 27 lesions were treated by enucleation (GE) and 13 underwent decompression (GD). Complementary treatment occurred in 38 (95%) lesions, of which 10 underwent isolated peripheral ostectomy (GO) and 28 underwent peripheral ostectomy combined with Carnoy's solution (GC). Thirteen lesions were associated with NBCCS (GS), while the others (n=27) were non-syndromic lesions (GnS). The recurrence-free periods (RFP) in the sample groups were compared using the Kaplan-Meier function and log-rank test at a significance level of 5% (p < 0.05) and were used to calculate the cumulative risk of recurrence (CRR) in each postoperative year. During the follow-up period, which had a mean of 43.5 months (range: 12–102 months), six (15%) recurrences were diagnosed. There was no significant difference among the RFP for the compared groups (p > 0.05) or increased CRR for the decompression (15.4%) over five years. Application of Carnoy's solution did not increase the efficacy of the peripheral ostectomy, but was related to a CRR of 0% for the syndromic lesions over five years. Therefore, 1) decompression did not increase the recurrence risk; 2) peripheral ostectomy demonstrated a similar efficacy as the combination with Carnoy's solution; 3) the association of NBCCS did not seem to significantly influence OKC recurrence; and 4) syndromic lesions seem to behave in the same manner as non-syndromic lesions when submitted to complementary treatments.</p></div