Unraveling sources of stimulus control in a temporal discrimination task

In temporal discriminations tasks, more than one stimulus may function as a time marker. We studied two of them in a matching-to-sample task, the sample keylight and the houselight that signaled the intertrial interval (ITI). One group of pigeons learned a symmetrical matching-to-sample task with two samples (2 s or 18 s of a center keylight) and two comparisons (red and green side keys), whereas another group of pigeons learned an asymmetrical matching-to-sample task with three samples (2 s, 6 s, and 18 s) and two comparisons (red and green). In the asymmetrical task, 6-s and 18-s samples shared the same comparison. In a subsequent retention test, both groups showed a preference for the comparison associated with the longer samples, a result consistent with the hypothesis that pigeons based their choices on the duration elapsed since the offset of the houselight (i.e., sample duration + retention interval). Results from two no-sample tests further corroborated the importance of the ITI illumination as a time marker: When the ITI was illuminated, the proportion of choices correlated positively with the retention interval; when the ITI was darkened, choices fell to random levels. However, the absolute value of choice proportions suggested that the sample stimulus was also a time marker. How multiple stimuli acquire control over behavior and how they combine remains to be worked out.     

Multilateral agencies and higher education reform in Latin America

During the last decade, the debate over higher education took up a significant space on the agendas of various international agencies, including multilateral development banks and other intergovernmental agencies. This fact points to the importance of the subject within a broader discussion that refers to national development projects and their articulation within the new international economic and political order. In this context, the purpose of this article is to discern the principal lines of argument at work and their implications for the transformation of higher education in Latin America. To this end, we have chosen four cases that we consider relevant for the region: The United Nations Education, Science and Cultural Organization (UNESCO), the World Bank, the Economic Commission for Latin America and the Caribbean (ECLA) and the Interamerican Development Bank (IADB). In the first part of the text we characterize the particularities of each of these organizations, highlighting their relation with the processes of educational change. In the second, we approach the subject of the recommendations made by the multilateral agencies on change in the higher education systems in the world and, particularly, in the Latin American region.     

Challenging neo-liberalism,building democracy: creating the Citizen School in Porto Alegre,Brazil

In this article, we situate the processes of educational policy and reform into their larger socio-political context. We describe the ways in which a set of policies has had what seem to be extensive and long lasting effects because the policies are coherently linked to larger dynamics of social transformation and to a coherent strategy that aims to change the mechanisms of the state and the rules of participation in the formation of state policies. We describe and analyse the policies of the ‘Popular Administration’ in Porto Alegre, Brazil. We specifically focus on the ‘Citizen School’ and on proposals that are explicitly designed to radically change both the municipal schools and the relationship between communities, the state and education. This set of policies and the accompanying processes of implementation are constitutive parts of a clear and explicit project aimed at constructing not only a better school for the excluded, but also a larger project of radical democracy. The reforms being built in Porto Alegre are still in formation, but we argue that they have crucial implications for how we might think about the politics of education policy and its dialectical role in social transformation.     

To learn and to construct knowledge in the context of work with adult education: a Portuguese case study

Work contexts are frequently referred to as spaces of learning and production of individual and/or collective knowledge. In such contexts specific dynamics are developed which cause the processes of learning and of knowledge production to have particularities. This paper aims at accounting for some dynamics that are associated with those processes, based on the main results of an ethnographic study on the adult educator team of a Portuguese local development association. The research identified ways of working/action rules based on the learning and knowledge production processes in the association. Mutual help, the reformulation and collectivization of practice, reflection in and about the action, and the negotiation of meaning about the practice are some of the mechanisms identified. The study also highlights how those dynamics of knowledge and learning and ways of doing may contribute to a practice which is closer to the needs of the adults to whom this team offers its education and training services.     

The origin of counting: A study of the early meaning of ‘one’, ‘two’ and ‘three’ among Basque- and Spanish-speaking children

This study examines the beginning of the conceptual understanding of the first number-words and what role language can play in developing the notion of numbers. To that end, 2?- and 3?-year-old Basque and Spanish monolingual children's (N = 131) basic numeracy skills are analysed by means of two different experimental procedures: Give-N (in which children are requested to gather sets of objects) and How-Many (based on the ability to count collections). The paper accounts for differences as regards the performance in the Give-N procedure between children with different linguistic backgrounds. In accordance with previous research, this finding can be related to the dissimilar ways by which languages (Basque and Spanish, in this case) express grammatical number, supporting the idea that language plays a definite role in the emergence of the earliest set-size meanings of ‘one,’ ‘two,’ and ‘three’ number-words. Eventually, the work attempts to contribute to the growing body of evidence that shows that the meaning of the count-list appears from mapping numerals onto numerical cognitive representations produced by early core systems of numbers.     

Aqueous extracts from Tenebrio molitor larval and pupal stages inhibit early hepatocarcinogenesis in vivo

Journal of Zhejiang University-SCIENCE B - 肝细胞癌 (HCC) 具有复杂的肿瘤内异质性,...     

Black and white transparency: contradictions of a moral metaphor

Transparency has evolved from an individual, dangerous power in Plato to a desirable, collective property in the contemporary world. This paper intends to give a brief account of this long and somehow surprising path and extract some interesting consequences for economic and political activities, as well as for information technologies. Six literary masterpieces are used to highlight the contradictions and dangers entailed by the abuse of the fascinating metaphor of transparency. In the end, what is usually intended when demanding transparency from a corporation, a firm or a state is more (or more accessible) information about it, i.e., understandable and abundant black and white data. This means reporting, picturing, producing material, becoming apparent, which is precisely the contrary of being transparent. We don’t want to look through, but to look directly at. The question, then, is not transparency, but opacity: what do we need and want to see, and how is this going to be produced?     

A Survey of School/College Partnerships for Minority and Disadvantaged Students

This study focuses on comprehensive partnerships between K–12 schools and postsecondary institutions which were created to improve the precollege academic preparation, college enrollment, and postsecondary success of minority and disadvantaged students. The study identified those partnerships that had been in existence in the United States for more than five years and surveyed them utilizing a 12-item questionnaire designed to determine the following: (1) structural characteristics; (2) funding; (3) success in achieving their goals and objectives; and (4) data collected to measure success.During the course of study, key informants from each partnership were surveyed. Partnership research has been scant, in part due to the fact that school-college partnerships of this type are a fairly new development in education. The results of the surveys have contributed new information to the field on the characteristics of partnerships. Findings also indicated that a majority of these partnerships incorporated some of the important characteristics for success recommended in the available literature. The partnerships consider themselves to be at least somewhat successful in achieving their goals of improving high school preparation and college enrollments for minority and disadvantaged students. They are, however, less informed about the success of their participants in college, especially college retention and graduation. They are also less informed about the availability of financial resources for their college aspirants and appear only marginally committed to creating institutional change.     

Learning Metabolism by Problem‐Based Learning Through the Analysis of Health or Nutrition Articles from the Web in Biochemistry

Problem‐based learning using authentic material from the web was used to teach metabolism in a biochemistry course. In place of traditional lectures, students’ analyzed health or nutrition articles from newspapers and magazines, which were debatable from a scientific point of view, following the principles of problem‐based learning. A mixed method was used to assess the students’ perception, use of sources of information and web services while performing the task, and changes in self‐directed learning. Students’ perception was particularly positive. The majority stated that the methodology helped them to apply knowledge to real life and that they learned about the topic analyzed by their group. The perception that problem‐based learning promotes the ability to solve problems, critical thinking, and collaborative work is noteworthy. Tutors considered that teams identified the problem and concluded correctly, noticing students’ enthusiasm and motivation. The methodology also promoted scientific reading. More importantly, a significant improvement in self‐directed learning of the 2014 cohort was detected. This intervention suggests that this methodology is a valuable alternative to motive and promote self‐learning; representing an opportunity to shift the focus of instruction from the teacher to the student. The design of the activity and materials are described in detail. Also, limitations and solutions are discussed.