Reading Comprehension in Latin America: Difficulties and Possible Interventions.

Reading comprehension (RC) is below the international standard in many countries of Latin America (LA). Here we review factors that might be associated with failure in RC of the first language in LA. Then we present interventions reporting beneficial impact on RC in typically developing students from English-speaking countries and discuss their possible applicability in LA. We conclude that research-based pedagogical interventions are currently available to promote RC at school and may be suitable to implement in LA in order to improve RC.

Position of Correct Option and Distractors Impacts Responses to Multiple-Choice Items: Evidence From a National Test.

Even though the impact of the position of response options on answers to multiple-choice items has been investigated for decades, it remains debated. Research on this topic is inconclusive, perhaps because too few studies have obtained experimental data from large-sized samples in a real-world context and have manipulated the position of both correct response and distractors. Since multiple-choice tests' outcomes can be strikingly consequential and option position effects constitute a potential source of measurement error, these effects should be clarified. In this study, two experiments in which the position of correct response and distractors was carefully manipulated were performed within a Chilean national high-stakes standardized test, responded by 195,715 examinees. Results show small but clear and systematic effects of options position on examinees' responses in both experiments. They consistently indicate that a five-option item is slightly easier when the correct response is in A rather than E and when the most attractive distractor is after and far away from the correct response. They clarify and extend previous findings, showing that the appeal of all options is influenced by position. The existence and nature of a potential interference phenomenon between the options' processing are discussed, and implications for test development are considered.

Proteomic analysis of oligodendrogliomas expressing a mutant isocitrate dehydrogenase-1.

Gliomas are primary tumors of the human central nervous system with unknown mechanisms of progression. Isocitrate dehydrogenase-1 (IDH1) mutation is frequent in diffuse gliomas such as oligodendrogliomas. To gain insights into the physiopathology of oligodendrogliomas that have a better prognosis than other diffuse gliomas, we combined microdissection, 2-D DIGE and MS/MS focusing on proteome alterations associated with IDH1 mutation. We first compared tumor tissues (TT) and minimally infiltrated parenchymal tissues (MIT) of four IDH1-mutated oligodendrogliomas to verify whether proteins specific to oligodendroglioma tumor cells could be identified from one patient to another. This study resulted in identification of 68 differentially expressed proteins, with functions related to growth of tumor cells in a nervous parenchyma. We then looked for proteins distinctly expressed in TT harboring either mutant (oligodendrogliomas, n=4) or wild-type IDH1 (oligodendroglial component of malignant glio-neuronal tumors, n=4). This second analysis resulted in identification of distinct proteome patterns composed of 42 proteins. Oligodendrogliomas with a mutant IDH1 had noteworthy enhanced expression of enzymes controlling aerobic glycolysis and detoxification, and anti-apoptosis proteins. In addition, the mutant IDH1 migrated differently from the wild-type IDH1 form. Comparative proteomic analysis might thus be suitable to identify proteome alterations associated with a well-defined mutation.