Distributed search based on self-indexed compressed text

Query response times within a fraction of a second in Web search engines are feasible due to the use of indexing and caching techniques, which are devised for large text collections partitioned and replicated into a set of distributed-memory processors. This paper proposes an alternative query processing method for this setting, which is based on a combination of self-indexed compressed text and posting lists caching. We show that a text self-index (i.e., an index that compresses the text and is able to extract arbitrary parts of it) can be competitive with an inverted index if we consider the whole query process, which includes index decompression, ranking and snippet extraction time. The advantage is that within the space of the compressed document collection, one can carry out the posting lists generation, document ranking and snippet extraction. This significantly reduces the total number of processors involved in the solution of queries. Alternatively, for the same amount of hardware, the performance of the proposed strategy is better than that of the classical approach based on treating inverted indexes and corresponding documents as two separate entities in terms of processors and memory space.     

Institutional experience of PTH evaluation on fine-needle washing after aspiration biopsy to locate hyperfunctioning parathyroid tissue

Assaying parathyroid hormone (PTH) in the washing liquid after fine-needle aspiration biopsy (FNAB) seems to be a valid approach to locate parathyroid tissue. PTH-FNAB was evaluated in 47 patients with a clinical picture of primary hyper-parathyroidism (PHP) and ultrasonography (US) suggestive of parathyroid lesion. The patients were subdivided into two groups on the basis of the absence or presence of US thyroid alterations. The result of PTH-FNAB was compared with those of cytology, scintigraphy and, in 24 patients, surgical outcome. PTH-FNAB samples with a value higher than that recorded in the serum and higher than our institutional cut-off were deemed to be probable samples of parathyroid tissue. Cytology proved diagnostic for benign thyroid lesions, non-diagnostic for thyroid lesions, hyperplastic parathyroid tissue, undetermined or malignant thyroid lesions and other lesions in 45%, 30%, 17%, 4%, and 4% of cases, respectively. In 47% of cases, PTH-FNAB indicated that the sample had been taken in parathyroid tissue. In patients without US alterations, the diagnostic accuracy of PTH-FNAB was greater than that of scintigraphy. After surgery, comparison between the results of PTH-FNAB and scintigraphy, in terms of positive predictive value (PPV), revealed the superiority of PTH-FNAB; PPV was 94% for FNAB and 71% for scintigraphy, while sen-sitivity was 83% and 69%, respectively. PTH-FNAB evaluation after FNAB appears to be more diagnostic than cytology and scintigraphy. Of all the procedures used, PTH-FNAB appears to be the method of choice when the target is US suggestive and reachable. PTH-FNAB appears to be a useful method of guiding surgical intervention.     

Biofouling of crypts of historical and architectural interest at La Plata Cemetery (Argentina)

Cemeteries are part of the cultural heritage of urban communities, containing funerary crypts and monuments of historical and architectural interest. Efforts aimed at the conservation of these structures must target not only the abiotic stresses that cause their destruction, such as light and humidity, but also biofouling by biotic agents. The purpose of this study was to assess the development of biofouling of several historically and architecturally valuable crypts at La Plata Cemetery (Argentina). Samples obtained from the biofilms, lichens, and fungal colonies that had developed on the marble surfaces and cement mortar of these crypts were analyzed by conventional microbiological techniques and by scanning electron microscopy. The lichens were identified as Caloplaca austrocitrina, Lecanora albescens, Xanthoparmelia farinosa and Xanthoria candelaria, the fungi as Aspergillus sp., Penicillium sp., Fusarium sp., Candida sp. and Rhodotorula sp., and the bacteria as Bacillus sp. and Pseudomonas sp. The mechanisms by which these microorganisms cause the aesthetic and biochemical deterioration of the crypts are discussed.     

The impact of funding on research collaboration: Evidence from a developing country

In this paper we evaluate the impact of research grants on the amount of collaboration among scientific researchers in Argentina. We find a positive and significant impact of funding on collaboration which is measured in terms of the number of co-authors for publications in peer-reviewed journals. Our identification strategy is based on comparing collaboration indicators for researchers with financially supported projects with those of a control group of researchers who submitted projects that were accepted in terms of quality, but not supported because of shortage of funds. We obtain consistent results by using different non-experimental techniques including difference-in-differences models combined with propensity score matching algorithms.     

Comparing Graphical and Verbal Representations of Measurement Error In Test Score Reports

Research has shown that many educators do not understand the terminology or displays used in test score reports and that measurement error is a particularly challenging concept. We investigated graphical and verbal methods of representing measurement error associated with individual student scores. We created four alternative score reports, each constituting an experimental condition, and randomly assigned them to research participants. We then compared comprehension and preferences across the four conditions. In our main study, we collected data from 148 teachers. For comparison, we studied 98 introductory psychology students. Although we did not detect statistically significant differences across conditions, we found that participants who reported greater comfort with statistics tended to have higher comprehension scores and tended to prefer more informative displays that included variable-width confidence bands for scores. Our data also yielded a wealth of information regarding existing misconceptions about measurement error and about score-reporting conventions.     

Using profile expansion techniques to alleviate the new user problem

Collaborative Filtering techniques have become very popular in the last years as an effective method to provide personalized recommendations. They generally obtain much better accuracy than other techniques such as content-based filtering, because they are based on the opinions of users with tastes or interests similar to the user they are recommending to. However, this is precisely the reason of one of its main limitations: the cold-start problem. That is, how to recommend new items, not yet rated, or how to offer good recommendations to users they have not information about. For example, because they have recently joined the system. In fact, the new user problem is particularly serious, because an unsatisfied user may stop using the system before it could even collect enough information to generate good recommendations. In this article we tackle this problem with a novel approach called “profile expansion”, based on the query expansion techniques used in Information Retrieval. In particular, we propose and evaluate three kinds of techniques: item-global, item-local and user-local. The experiments we have performed show that both item-global and user-local offer outstanding improvements in precision, up to 100%. Moreover, the improvements are statistically significant and consistent among different movie recommendation datasets and several training conditions.     

Revisions to rationality: the translation of ‘new knowledges’ into policy under the Coalition Government

This article gives an account of the use of knowledges from emerging scientific fields in education and youth policy making under the Coalition government (2010–15) in the UK. We identify a common process of ‘translation’ and offer three illustrations of policy-making in the UK that utilise diverse knowledges produced in academic fields (neuroscience, network theory and well-being). This production of ‘new knowledges’ in policy contexts allows for the identification of sites of policy intervention. This process of translation underlies a series of diverse revisions of the rational subject of policy. Collectively, these revisions amount to a change in policy-making and the emergence of a different subject of neoliberal policy. This subject is not an excluded alterity to an included rational subject of neoliberalism, but a ‘plastic subject’ characterised by its multiplicity. The plastic subject does not contradict the rational subject as central to neoliberal policy-making, but diversifies it.     

Cultural discontinuity between home and school and American Indian and Alaska Native children's achievement

An assumption of culture-based education with respect to American Indian and Alaska Native (AI/AN) children is that discontinuity between home and school cultures is responsible for educational underachievement. Using data from the 2009 round of the National Indian Education Study, a subset of the larger National Assessment of Education Progress (NAEP), the author constructed a measure of cultural discontinuity and examined its relationship to AI/AN students' Grade 4 and 8 reading and mathematics achievement. Contrary to the cultural discontinuity hypothesis, there is no statistically significant negative relationship when the culture of the home is discontinued at school. On the Grade 4 NAEP reading assessment, in particular, cultural discontinuity was positively associated with students' achievement, net of both student- and school-level controls. Findings suggest that the assumptions of culture-based education may be overstated, though longitudinal data are still needed to be able to make causal claims.     

Transitions in the manifestations of the research culture of Spanish universities

Universities must adapt to the challenges of social competitiveness and its new demands but there is still little evidence of how these changes are perceived by the academics. This paper provides insight on this matter and analyses the research culture of five Spanish universities from the perspective of the different academic bodies. A qualitative methodology was employed in the study based on 43 in-depth interviews with institutional leaders (vice-rectors and managers), responsible for research activity, (directors of research centres) and individual researchers (doctoral and postdoctoral researchers). The results point to a clear change in the institutional mission that moves from an institutional model where teaching and research cohabitate together towards another where research activity intensifies. The manifestations of the new research culture is characterised by the quest for efficiency and competitiveness at all levels and bodies. Despite the changes in the university model, participants perceive that the traditional and new models coexist and affect the university structure, the functioning of the centres and departments and the dynamics of the research teams which causes dissatisfaction of the researchers that in this context have to deal with the increasing pressure to publish and obtain external funding to assure ‘survival’. The research culture is also characterised as one that moves towards the scarcity of support measures for training, the confusion perceived between the political discourse and academic practice and the attempt to reposition the university in a social context, through redefining its role and fostering transfer activities.