Is there a real diagnostic impact of elastosonography and contrast-enhanced ultrasonography in the management of thyroid nodules?

Ultrasonography(US) and the new applications US elastography(USE) and contrast-enhanced US(CEUS) are used in the screening of thyroid nodules,for which fine-needle aspiration biopsy(FNAB) is the best single diagnostic test.The aim of the study was to compare the sensitivity,specificity,positive predictive value(PPV),and accuracy of the four examinations in nodules with cytological and histological diagnoses.The study used data from US,FNAB,USE(elasticity(ELX 2/1) index),and CEUS(Peak index and time to peak(TTP) index) evaluated in 73 thyroid nodules in 63 consecutive patients likely to undergo surgery.Cytological-histological correlation was available for 38 nodules.No correlation emerged between nodule size and cytological results.A significant(P=0.03) positive correlation between cumulative US findings and cytological results was found.In addition,significant correlations between cumulative US findings and cytology(P=0.02) and between cumulative US findings and histology(P<0.0001) were found.US showed the best specificity and PPV,and FNAB the best sensitivity.There was no significant difference in the ELX 2/1 index,Peak index,or TTP index among nodules subdivided according to cytological scores.No significant correlation was found between ELX 2/1 index,Peak index,and TTP index,on the one hand,and nodule size,US cumulative findings,cytology,and histology on the other hand.The sensitivity of the ELX 2/1 index was high,but its specificity was very low.The accuracy and PPV of USE were lower than those of the other procedures.Only the correlation between Peak index and cumulative US findings reached a value close to significance.Our ultimate aim is to minimise unnecessary thyroidectomy.US and FNAB continue to play a central diagnostic role.The use of a US score showed high specificity and PPV.The specificity of FNAB was low in this selected series because of the numbers of indeterminate cytological responses.USE and CEUS are innovative techniques that need to be standardized.The ELX 2/1 index,Peak index,and TTP index seem to be unrelated to histology.The best statistical data on USE and CEUS concerned their sensitivity and PPV,respectively.At present,USE and CEUS are too time-consuming and of limited utility in selecting patients for surgery.     

Orchids in the Roman culture and iconography: Evidence for the first representations in antiquity

Orchids have fascinated humans since ancient times. Not only the particular morphology of their flowers and hypogean organs, but also their reproductive biology have inspired myths, legends and popular traditions in many cultures, all around the world. Despite these facts, their representations on ancient artefacts have never been described in the scientific literature. No clear data exist for Eastern culture, and in Western countries, the first certain representations of orchids in art date back to the XV-XVI century CE. This paper documents different identifications of orchids on Roman monuments changing the common belief that these plants first appeared in art more recently. Floral elements of Cephalanthera spp., Spiranthes spiralis (L.) Chevall, of Orchis tridentata Scop., and of other orchids were observed in different architectonical elements (cornices and ceilings) throughout the Roman period, and in the external frieze of the Ara Pacis monument (I century CE). These representations seem to refer to a symbolism of fertility and sexuality, and their absence in medieval time can be explained only considering religion influences.     

The influence of causal knowledge on the willingness to change attitude towards climate change: results from an empirical study

ABSTRACT

Climate change is one of the significant global challenges currently facing humanity. Even though its seriousness seems to be common knowledge among the public, the reaction of individuals to it has been slow and uncertain. Many studies assert that simply knowing about climate change is not enough to generate people’s behavioural response. They claim, indeed, that in some cases scientific literacy can even obstruct behavioural response instead. However, recent surveys show a rather poor understanding of climate dynamics and argue that lack of knowledge about causal relationships within climate dynamics can hinder behavioural response, since the individual is not able to understand his/her role as causal agent and therefore doesn’t know how to take proper action. This study starts from the hypothesis that scientific knowledge focused on clarifying climate dynamics can make people understand not only dynamics themselves, but also their interactive relationship with the environment. Teaching materials on climate change based on such considerations were designed and implemented in a course for secondary-school students with the aim of investigating whether this kind of knowledge had an influence on students’ willingness to adopt pro-environmental behaviours. Questionnaires were delivered for testing the effect of the teaching experience on knowledge and behaviour.     

Enhancing web page classification through image-block importance analysis

We present a term weighting approach for improving web page classification, based on the assumption that the images of a web page are those elements which mainly attract the attention of the user. This assumption implies that the text contained in the visual block in which an image is located, called image-block, should contain significant information about the page contents. In this paper we propose a new metric, called the Inverse Term Importance Metric, aimed at assigning higher weights to important terms contained into important image-blocks identified by performing a visual layout analysis. We propose different methods to estimate the visual image-blocks importance, to smooth the term weight according to the importance of the blocks in which the term is located. The traditional TFxIDF model is modified accordingly and used in the classification task. The effectiveness of this new metric and the proposed block evaluation methods have been validated using different classification algorithms.     

Teachers’ response to curriculum change: balancing external and internal change forces

The present study investigates teachers’ perceptions of curriculum change targeting the expanded freedom teachers were given as curriculum developers in the implementation process of the 2006 school reform in Norway. The new curriculum marks a distinct shift, moving from a content-driven to a learning outcomes-driven curriculum. Policy makers expressed confidence in teachers’ professional autonomy: local curricula had to be designed in all subjects to meet the learning outcomes defined in the curriculum. This qualitative study uses focus group interviews and addresses teachers in primary and lower secondary school. Teachers do not see their expanded freedom as real freedom; their world is deeply contextualized and they see a gap between their experienced world and the intended world of the curriculum. What was communicated as extended freedom by policy makers is perceived as extended demands. In this initial phase the teachers place themselves in the position of respondents rather than being progressive change agents themselves.     

Writing to learn ecology: a study of three populations of college students

Being an ecologically literate citizen involves making decisions that are based on ecological knowledge and accepting responsibility for personal actions. Using writing-to-learn activities in college science courses, we asked students to consider personal dilemmas that they or others might have in response to how human choices can impact coastal dead zones around the world. We explored how undergraduate students (42 biology and 47 elementary education majors at a 4-year college and eight Native studies majors at a tribal college in the United States) identified their ecological dilemmas after reading about aquatic hypoxia. About 30% of the 4-year college students’s essays demonstrated a more ecologically literate understanding of hypoxia by the end of the study. The tribal college students improved their ecological literacy by 50%, albeit with a small sample size. Biology majors made more human-centered comments than the education majors. The Native American students often discussed trade-offs between quality of life and ecological consequences, and were classified as both human-centered and ecosystem-centered.     

Chemical characterization and AMS radiocarbon dating of the binder of a prehistoric rock pictograph at Tadrart Acacus, southern west Libya

The analysis of the amino acid (AA) content in fragments derived from a prehistoric rock pictograph (Lancusi rock shelter) at Tadrart Acacus, southern west Libya, revealed the presence of material containing peptides differing in solubility in hot acidic or alkaline solutions, as well as in AA composition and racemization. Water-soluble components were constituted of low molecular weight peptides with high racemization of aspartic acid and alanine, whereas the water insoluble material consisted of species of a more complex AA composition and a different degree of racemization. The proteinaceous materials were assumed to originate from matter that had undergone over time different diagenetic processes. The water insoluble peptide-containing material was separated from the rock substrate by acid hydrolysis, dried and the resulting residue submitted to radiocarbon analysis. Accelerator mass spectrometry (AMS) yielded an approximate age of 6145 ± 70 years B.P. (before present), which is consistent with archaeological inference and the climatic reconstruction of central Sahara. To our knowledge the present work represents the first attempt of direct radiocarbon dating of rock art in the Sahara desert.     

Understanding glocal learning spaces. An empirical study of languaging and transmigrant positions in the virtual classroom

The use of digital tools like computers and tablets in institutional learning arenas give rise to forms of flexibility where time and space boundaries become diffuse. Online learning sites are understood as being crucial today, especially in large parts of the Global North, where anyone anywhere potentially can become a student and have access to educational opportunities.

This study focuses on the analysis of recorded sessions, part of an ‘Italian for (adult) beginners' online course. Our interests relate to accounting for how students negotiate different language varieties, including modalities, and how communication in virtual learning settings enables both flexible participation trajectories and identity positions in and across the boundaries of time and space.

The sociocultural and dialogical analyses here are framed in terms of fluidity of ‘glocal' positions and (trans)languaging that emerge in and across time and space in Technology Mediated Communication. Our findings suggest that online environments support meaning-making where it is possible to identify alternative ways of (co)constructing and mediating learning. Such hybridity as well as the performative character of learning and identity display have important implications for online glocal communities.     

Soft-constrained inference for Named Entity Recognition

Much of the valuable information in supporting decision making processes originates in text-based documents. Although these documents can be effectively searched and ranked by modern search engines, actionable knowledge need to be extracted and transformed in a structured form before being used in a decision process. In this paper we describe how the discovery of semantic information embedded in natural language documents can be viewed as an optimization problem aimed at assigning a sequence of labels (hidden states) to a set of interdependent variables (textual tokens). Dependencies among variables are efficiently modeled through Conditional Random Fields, an indirected graphical model able to represent the distribution of labels given a set of observations. The Markov property of these models prevent them to take into account long-range dependencies among variables, which are indeed relevant in Natural Language Processing. In order to overcome this limitation we propose an inference method based on Integer Programming formulation of the problem, where long distance dependencies are included through non-deterministic soft constraints.