Alguns aspectos sociológicos dos sistemas formais de comunicação do conhecimento

Embora as origens dos sistemas formais de transmissão do conhecimento se percam na névoa dos tempos, é certo que eles se achavam nas mãos dos governantes, comumente reis ou sacerdotes. Descobrimentos como os dos sumérios e egípcios, relativos às cheias e vazantes dos grandes rios, tão importantes para a Agricultura, eram transmitidos pela tradição oral, e, se registrados, o eram no maior segredo

A kinetic model of single and clustered IP3 receptors in the absence of Ca2+ feedback

Ca2+ liberation through inositol 1,4,5- trisphosphate receptor (IP3R) channels generates complex patterns of spatiotemporal cellularCa(2+) signals owing to the biphasic modulation of channel gating by Ca2+ itself. These processes have been extensively studied in Xenopus oocytes, where imaging studies have revealed local Ca2+ signals ("puffs'') arising from clusters of IP3R, and patch-clamp studies on isolated oocyte nuclei have yielded extensive data on IP3R gating kinetics. To bridge these two levels of experimental data, we developed an IP3R model and applied stochastic simulation and transition matrix theory to predict the behavior of individual and clustered IP(3)Rchannels. The channel model consists of four identical, independent subunits, each of which has an IP3- binding site together with one activating and one inactivating Ca2+- binding site. The channel opens when at least three subunits undergo a conformational change to an "active'' state after binding IP3 and Ca2+. The model successfully reproduces patch- clamp data; including the dependence of open probability, mean open duration, and mean closed duration on [IP3] and [Ca2+]. Notably, the biexponential distribution of open- time duration and the dependence of mean open time on [Ca2+] are explained by populations of openings involving either three or four active subunits. As a. rst step toward applying the single IP3R model to describe cellular responses, we then simulated measurements of puff latency after step increases of [IP3]. Assuming that stochastic opening of a single IP3R at basal cytosolic [Ca2+] and any given [IP3] has a high probability of rapidly triggering neighboring channels by calcium- induced calcium release to evoke a puff, optimal correspondence with experimental data of puff latencies after photorelease of IP3 was obtained when the cluster contained a total of 40 - 70 IP(3)Rs

Assessment innovation and student experience: a new assessment challenge and call for a multi-perspective approach to assessment research

The impact of innovative assessment on student experience in higher education is a neglected research topic. This represents an important gap in the literature given debate around the marketization of higher education, international focus on student satisfaction measurement tools and political calls to put students at the heart of higher education in the UK. This paper reports on qualitative findings from a research project examining the impact of assessment preferences and familiarity on student attainment and experience. It argues that innovation is defined by the student, shaped by diverse assessment experiences and preferences and therefore its impact is difficult to predict. It proposes that future innovations must explore assessment choice mechanisms which allow students to shape their own assessments. Cultural change and staff development will be required to achieve this. To be accepted, assessment for student experience must be viewed as a complementary layer within a complex multi perspective model of assessment which also embraces assessment of learning, assessment for learning and assessment for life long learning. Further research is required to build a meta theory of assessment to enhance the synergies between these alternative approaches and to minimise tensions between them

Stratified University Strategies: The Shaping of Institutional Legitimacy in a Global Perspective

Globalizing forces have both transformed the higher education sector and made it increasingly homogenous. Growing similarities among universities have been attributed to isomorphic pressures to ensure and/or enhance legitimacy by imitating higher education institutions that are perceived as successful internationally, particularly universities that are highly ranked globally (Cantwell & Kauppinen, 2014; DiMaggio and Powell, 1983). In this study, we compared the strategic plans of 78 high-ranked, low-ranked, and unranked universities in 33 countries in 9 regions of the world. In analyzing the plans of these 78 universities, the study explored patterns of similarity and difference in universities' strategic positioning according to Suchman's (1995) 3 types of legitimacy: cognitive, pragmatic, and moral. We found evidence of stratified university strategies in a global higher education landscape that varied by institutional status. In offering a corrective to neoinstitutional theory, we suggest that patterns of globalization are mediated by status-based differences in aspirational behavior (Riesman, 1958) and "old institutional" forces (Stinchcombe, 1997) that contribute to differently situated universities pursuing new paths in seeking to build external legitimacy.18 month embargo; published online: 13 Sep 2018This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Effects of carbohydrate and caffeine ingestion on performance during a rugby union simulation protocol

In this study, we investigated the effect of ingesting carbohydrate alone or with caffeine on performance of a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced trial order, eight male rugby union forwards ingested either placebo or carbohydrate (1.2g center dot kg-1 body mass center dot h-1) before and during a rugby union-specific protocol, with pre-exercise caffeine ingestion (4mg center dot kg-1) before one of the carbohydrate trials (carbohydrate+caffeine). The intermittent exercise protocol included walking, jogging, and cruising at pre-determined intensities, simulated contact events, a sustained high-intensity test of speed and agility (Performance Test), and a 15-m sprint. Ratings of perceived exertion (RPE) were recorded every 5min and a motor skills test was performed after each 21-min block. Performance Test times were not significantly different between trials but the likelihood of 2% improvements for carbohydrate+caffeine over placebo and carbohydrate were 98% and 44%, respectively. For carbohydrate+caffeine, 15-m sprints were faster than for placebo (P=0.05) and the motor skills test was performed faster in the carbohydrate+caffeine trial than the carbohydrate and placebo trials (P0.05), while RPE was lower in the carbohydrate+caffeine trial than the carbohydrate and placebo trials (P0.05). The results indicate a likely benefit to rugby performance following co-ingestion of carbohydrate and caffeine

The research-teaching nexus: A case study of students' awareness, experiences and perceptions of research

This paper presents a case study of students' awareness, experiences and perceptions of research in a 'new' university in the UK. The findings are based on a questionnaire of almost 200 students and five small group interviews. Many of the students participating in this research perceived clear benefits to their learning from staff research, including being taught by enthusiastic staff, enhanced staff credibility, and the reflected glory of being taught by well-known researchers. However, they also perceived disadvantages, particularly with regard to staff availability, and did not believe that staff research should take priority over their needs as learners. They recognised that their awareness of the nature of research and the development of research skills increased most when they were actively involved in undertaking research projects. Several students also perceived benefits for future employment from their participation in research activities. The questionnaire has been used by several other universities around the world to benchmark their practices. © 2010 Taylor & Francis

Gene expression profiles derived from fine needle aspiration correlate with response to systemic chemotherapy in breast cancer

BACKGROUND: Drug resistance in breast cancer is a major obstacle to successful chemotherapy. In this study we used cDNA microarray technology to examine gene expression profiles obtained from fine needle aspiration (FNA) of primary breast tumors before and after systemic chemotherapy. Our goal was to determine the feasibility of obtaining representative expression array profiles from limited amounts of tissue and to identify those expression profiles that correlate with treatment response. METHODS: Repeat presurgical FNA samples were taken from six patients who were to undergo primary surgical treatment. Additionally, a group of 10 patients who were to receive neoadjuvant chemotherapy underwent two FNAs before chemotherapy (adriamycin 60 mg/m(2) and cyclophosphamide 600 mg/m(2)) followed by another FNA on day 21 after the first cycle. Total RNA was amplified with T7 Eberwine's procedure and labeled cDNA was hybridized onto a 7600-feature glass cDNA microarray. RESULTS: We identified candidate gene expression profiles that might distinguish tumors with complete response to chemotherapy from tumors that do not respond, and found that the number of genes that change after one cycle of chemotherapy was 10 times greater in the responding group than in the non-responding group. CONCLUSION: This study supports the suitability of FNA-derived cDNA microarray expression profiling of breast cancers as a comprehensive genomic approach for studying the mechanisms of drug resistance. Our findings also demonstrate the potential of monitoring post-chemotherapy changes in expression profiles as a measure of pharmacodynamic effect and suggests that these approaches might yield useful results when validated by larger studies

Data-Driven Modelling of the Inositol Trisphosphate Receptor (IPR) and its Role in Calcium-Induced Calcium Release (CICR)

We review the current state of the art of data-driven modelling of the inositol trisphosphate receptor (IPR). After explaining that the IPR plays a crucial role as a central regulator in calcium dynamics, several sources of relevant experimental data are introduced. Single ion channels are best studied by recording single-channel currents under different ligand concentrations via the patch-clamp technique. The particular relevance of modal gating, the spontaneous switching between different levels of channel activity that occur even at constant ligand concentrations, is highlighted. In order to investigate the interactions of IPRs, calcium release from small clusters of channels, so-called calcium puffs, can be used. We then present the mathematical framework common to all models based on single-channel data, aggregated continuous-time Markov models, and give a short review of statistical approaches for parameterising these models with experimental data. The process of building a Markov model that integrates various sources of experimental data is illustrated using two recent examples, the model by Ullah et al. and the “Park–Drive” model by Siekmann et al. (Biophys. J. 2012), the only models that account for all sources of data currently available. Finally, it is demonstrated that the essential features of the Park–Drive model in different models of calcium dynamics are preserved after reducing it to a two-state model that only accounts for the switching between the inactive “park” and the active “drive” modes. This highlights the fact that modal gating is the most important mechanism of ligand regulation in the IPR. It also emphasises that data-driven models of ion channels do not necessarily have to lead to detailed models but can be constructed so that relevant data is selected to represent ion channels at the appropriate level of complexity for a given application

Sprouty Proteins Inhibit Receptor-mediated Activation of Phosphatidylinositol-specific Phospholipase C

PLCγ03B3 binds Spry1 and Spry2. Overexpression of Spry decreased PLCγ03B3 activity and IP3 and DAG production, whereas Spry-deficient cells yielded more IP3. Spry overexpression inhibited T-cell receptor signaling and Spry1 null T-cells hyperproliferated with TCR ligation. Through action of PLCγ03B3, Spry may influence signaling through multiple receptors