Application of Item Response Theory to Mathematics High School Exams in Portugal

Item Response Theory (IRT) provides statistical models that relate an examinee’s response to a test item to an underlying latent trait that is measured by the items. Unlike classical test theory, IRT models focus on the responses to individual questions instead on the total score obtained in the test. In this paper we apply IRT models to the results of the quiz part of the first and second calls of mathematics exams accomplished by high school graduating students in Portugal, in the years 2008, 2009 and 2010. We concluded that the quiz part of the first call exams had a difficulty level lower than the students median ability, whereas the quiz part of the second call exams had a difficulty level higher than the students median ability

Pharmacological characterization of Solanum cernuum Vell.: 31-norcycloartanones with analgesic and anti-inflammatory properties

Cycloeucalenone (1) and 24-oxo-31-norcycloartanone (2) obtained from Solanum cernuum Vell. were assayed to explore their pharmacologic roles. Previous studies showed that (2) has selective activity against lung tumor cell line (NCIH460) which expresses high levels of COX-2, suggesting its role in inflammatory process, and also a link between chronic inflammation and cancer-associated process. Dichloromethane crude extract (DCE) significantly reduced writhing and stretching induced by 0.8 % acetic acid at a dose of 100, 300, and 600 mg/kg, po; oral administration of different doses of (1) and (2) also displayed significant analgesic and anti-inflammatory effects in the writhing acetic acid test (p < 0.0001). Selected oral doses of both compounds (100 and 50 mg/kg) were assayed in the carrageenan-induced paw edema model. Compound (2) showed significant activity during the early phase (1.5-6 h) and also in the late phase (48 h) (p < 0.01). The anti-nociceptive activity observed for the compounds (1) and (2) and DCE was found to be related to the inhibition of different mediators involved in inflammation and nociceptive process. Both compounds decrease COX-2 protein expression, although only compound (2) reached a significant response (p < 0.05 vs control). However, in vitro Sirtuin 1 activity and TNF-alpha production in THP-1 macrophages were not affected3179185Andalucia Government, Spain - Proyecto de Excelencia-Polfanat; Programa de Mestrado em Uso Racional de Medicamentos of the Universidade de Sorocaba (Brazil

Tuberculose, HIV e pobreza: tendência temporal no Brasil, Américas e mundo Tuberculosis, HIV, and poverty: temporal trends in Brazil, the Americas, and worldwide

OBJETIVO: Analisar a tendência temporal das taxas de prevalência, incidência e mortalidade por tuberculose, associada ou não com HIV, no Brasil, nas Américas e no mundo. MÉTODOS: Foram coletados os dados relacionados à tuberculose, com e sem coinfecção por HIV, entre 1990 e 2010, no Brasil, nas Américas e no mundo. As tendências foram estimadas por regressão linear. RESULTADOS: Foi identificada uma tendência de redução nas taxas de prevalência e mortalidade de tuberculose, que foi maior no Brasil e nas Américas que no mundo. Houve uma tendência crescente na incidência da coinfecção tuberculose/HIV e nas taxas de detecção de casos de tuberculose ativa e latente. Houve uma tendência de redução da incidência de tuberculose no Brasil, mas de aumento dessa no mundo. Houve uma correlação direta das taxas de incidência de tuberculose com as taxas de pobreza e as taxas de incidência de HIV. CONCLUSÕES: Desigualdades sociais e o advento da AIDS são os principais fatores que agravam a atual situação da tuberculose. Nesse contexto, abordagens metodológicas para a avaliação das ações de vigilância da tuberculose são bem-vindas, pois essas indicarão situações de dados de notificação da tuberculose que não reflitam a verdadeira incidência dessa doença.<br>OBJECTIVE: To analyze the temporal trends of the incidence and prevalence of tuberculosis, with and without HIV co-infection, as well as of the associated mortality, in Brazil, the Americas, and worldwide. METHODS: We collected data related to tuberculosis, with and without HIV co-infection, between 1990 and 2010, in Brazil, the Americas, and worldwide. Temporal trends were estimated by linear regression. RESULTS: We identified a trend toward a decrease in tuberculosis prevalence and mortality, and that trend was more pronounced in Brazil and the Americas than worldwide. There was also a trend toward an increase in the incidence of tuberculosis/HIV co-infection, as well as in the rates of detection of new cases of active and latent tuberculosis. The incidence of tuberculosis was found to trend downward in Brazil, whereas it trended upward worldwide. Tuberculosis incidence rates correlated positively with poverty rates and with HIV incidence rates. CONCLUSIONS: Social inequality and the advent of AIDS are the major factors that aggravate the current situation of tuberculosis. In this context, methodical approaches to the assessment of surveillance activities are welcome, because they will identify situations in which the reported tuberculosis data do not reflect the true incidence of this disease

Diastereoselective Synthesis of Biologically Active Cyclopenta[<i>b</i>]indoles

The cyclopenta­[<i>b</i>]­indole motif is present in several natural and synthetic biologically active compounds, being directly responsible for the biological effects some of them present. We described herein a three step sequence for the synthesis of cyclopenta­[<i>b</i>]­indoles with a great structural diversity. The method is based on an oxidative Michael addition of suitable indoles on the double bond of Morita–Baylis–Hillman adducts mediated by a hypervalent iodine reagent (IBX) to form β-ketoesters, which were chemoselectively reduced with NaBH₄ in THF to give the corresponding β-hydroxy-esters. The diastereoisomeric mixture was then treated with a catalytic amount of triflic acid (20 mol %) to give cyclopenta­[<i>b</i>]­indoles with overall yields ranging from 8 to 73% (for 2 steps). The acid-catalyzed cyclization step gave the required heterocycles, via an intramolecular Friedel–Crafts reaction, with high diastereoselectivity, where only the <i>trans</i> product was observed. A mechanistic study monitored by ESI-(+)-MS was also conducted to collect evidence about the mechanism of this reaction. The new molecules herein synthesized were also evaluated against a panel of human cancer cells demonstrating a promising antitumoral profile