Automatic labelling of topic models learned from Twitter by summarisation

Latent topics derived by topic models such as Latent Dirichlet Allocation (LDA) are the result of hidden thematic structures which provide further insights into the data. The automatic labelling of such topics derived from social media poses however new challenges since topics may characterise novel events happening in the real world. Existing automatic topic labelling approaches which depend on external knowledge sources become less applicable here since relevant articles/concepts of the extracted topics may not exist in external sources. In this paper we propose to address the problem of automatic labelling of latent topics learned from Twitter as a summarisation problem. We introduce a framework which apply summarisation algorithms to generate topic labels. These algorithms are independent of external sources and only rely on the identification of dominant terms in documents related to the latent topic. We compare the efficiency of existing state of the art summarisation algorithms. Our results suggest that summarisation algorithms generate better topic labels which capture event-related context compared to the top-n terms returned by LDA. © 2014 Association for Computational Linguistics.

Phytoplankton-bacteria coupling under elevated CO2 levels: a stable isotope labelling study, 2010

The potential impact of rising carbon dioxide (CO2) on carbon transfer from phytoplankton to bacteria was investigated during the 2005 PeECE III mesocosm study in Bergen, Norway. Sets of mesocosms, in which a phytoplankton bloom was induced by nutrient addition, were incubated under 1x (~350 µatm), 2x (~700 µatm), and 3x present day CO2 (~1050 µatm) initial seawater and sustained atmospheric CO2 levels for 3 weeks. 13C labelled bicarbonate was added to all mesocosms to follow the transfer of carbon from dissolved inorganic carbon (DIC) into phytoplankton and subsequently heterotrophic bacteria, and settling particles. Isotope ratios of polar-lipid-derived fatty acids (PLFA) were used to infer the biomass and production of phytoplankton and bacteria. Phytoplankton PLFA were enriched within one day after label addition, whilst it took another 3 days before bacteria showed substantial enrichment. Group-specific primary production measurements revealed that coccolithophores showed higher primary production than green algae and diatoms. Elevated CO2 had a significant positive effect on post-bloom biomass of green algae, diatoms, and bacteria. A simple model based on measured isotope ratios of phytoplankton and bacteria revealed that CO2 had no significant effect on the carbon transfer efficiency from phytoplankton to bacteria during the bloom. There was no indication of CO2 effects on enhanced settling based on isotope mixing models during the phytoplankton bloom, but this could not be determined in the post-bloom phase. Our results suggest that CO2effects are most pronounced in the post-bloom phase, under nutrient limitation.

Changes in [18F]Fluoro-2-deoxy-D-glucose incorporation induced by doxorubicin and anti-HER antibodies by breast cancer cells modulated by co-treatment with metformin and its effects on intracellular signalling

Peer reviewed

Changes in [18F]Fluoro-2-deoxy-D-glucose incorporation induced by doxorubicin and anti-HER antibodies by breast cancer cells modulated by co-treatment with metformin and its effects on intracellular signalling

Peer reviewed

Changes in [18F]Fluoro-2-deoxy-D-glucose incorporation induced by doxorubicin and anti-HER antibodies by breast cancer cells modulated by co-treatment with metformin and its effects on intracellular signalling

Peer reviewed

From labelling to social aid for immigrants in the 21st Century

Migration is as old as humanity, but since the 1990s migration flows in Western Europe have led to societies that are not just multicultural but so-called «super-diverse». As a result, Western towns now have very complex social structures, with amongst others large amounts of small immigrant communities that are in constant change. In this paper we argue that for social workers to be able to offer adequate professional help to non-native residents in town, they will need balanced view of ‘culture’ and of the role culture plays in social aid. Culture is never static, but is continually changing. By teaching social workers about how to look at cultural backgrounds of immigrant groups and about the limitations of then role that culture plays in communication, they will be better equipped to provide adequate aid and will contribute to making various groups grow towards each other and to avoid people thinking in terms of ‘out-group-homogeneity’. Nowadays, inclusion is a priority in social work that almost every social worker supports. Social workers should have an open attitude to allow them to approach every individual as a unique person. They will see the other person as the person they are, and not as a part of a specific cultural group. Knowledge about the others makes them see the cultural heterogeneity in every group. The social sector, though, must be aware not to fall into the trap of the ‘inclusion mania’! This will cause the social deprivation of a particular group to be forgotten. An inclusive policy requires an inclusive society. Otherwise, this could result in even more deprivation of other groups, already discriminated against. Emancipation of deprived people demands a certain target-group policymaking. Categorized aid will raise efficiency of working with immigrants and of acknowledging the cultural identity of the non-natives group. It will also create the possibility to work on fighting social deprivation, in which most immigrants can be found.

Chinese Men and "Leftover Women" : How do Chinese Men Position Themselves in Relation to the Concept of Labelling Women as "Leftover"?

In recent years there has been a resurgence of gender inequality in China. Today, women are pressured to get married by the state and their social surroundings, as they told if they remain unmarried and have the "three highs"; high age, education and salary, they will become leftovers on the marriage market. Previous research on the concept of labelling women as "leftover" has 4 shown that labelling women as "leftover" can have several different negative impacts. In this thesis, both the theory of masculine hegemony and the theory of symbolic interaction have been used. The concept creates a hegemonic masculinity as it is a normative practice that promotes the subordination of women. However, as the concept is based on the notion that all Chinese men, or at least those of relevant social standing, would find the "three highs" undesirable, it is relevant to see how Chinese men in fact do position themselves in relation to the hegemonic masculinity on an individual level. In symbolic interaction, the concept of gender is created through social construction when people attach special meanings to the sex of a person, a process which is called "doing gender". Therefore symbolic interaction is used to see what special meaning Chinese men attach to women having the "three highs" and masculine hegemony to put their answers into a larger context. If it could be shown that Chinese men do not comply with the hegemonic masculinity, Chinese women would not have to feel obliged to adjust to the hegemonic masculinity and thereby making it easier for them to pursue higher education, high paying jobs and marrying at a later age. However, as this thesis is a qualitative study, and therefore a limited number of data subjects, the generalizability of the result should not be exaggerated. The interviews that were conducted for this thesis showed that the data subjects were familiar with the concept and that they considered it to be natural for there to be women China labelled as "leftover". Nevertheless, in relation to their own marital choices, the data subjects did not attach the negative meaning as set out by the hegemonic masculinity, a result which to some extent was confirmed by the data subjects’ experiences and other control questions. The result is interesting, and enforces Connell and MesserSchmidt’s theory, that even though a hegemonic masculinity is normative, not everyone has to comply with it. As the cornerstone of the concept is that Chinese men find women with the "three highs" undesirable, the result of the study shows that there is a need for the concept to be further examined and questioned.

Assessment of the quality of sample labelling for clinical research

Objective: To assess the quality of the labels for clinical trial samples through current regulations, and to analyze its potential correlation with the specific characteristics of each sample. Method: A transversal multicenter study where the clinical trial samples from two third level hospitals were analyzed. The eleven items from Directive 2003/94/EC, as well as the name of the clinical trial and the dose on the label cover, were considered variables for labelling quality. The influence of the characteristics of each sample on labelling quality was also analyzed. Outcome: The study included 503 samples from 220 clinical trials. The mean quality of labelling, understood as the proportion of items from Appendix 13, was of 91.9%. Out of these, 6.6% did not include the name of the sample in the outer face of the label, while in 9.7% the dose was missing. The samples with clinical trial-type samples presented a higher quality (p < 0.049), blinding reduced their quality (p = 0.017), and identification by kit number or by patient increased it (p < 0.01). The promoter was the variable which introduced the highest variability into the analysis. Conclusions: The mean quality of labelling is adequate in the majority of clinical trial samples. The lack of essential information in some samples, such as the clinical trial code and the period of validity, is alarming and might be the potential source for dispensing or administration errors.

Cerebrotendinous xanthomatosis with bradyphrenia and psychiatric disorders: a case with 18F-FDG PET imaging and a literature review

Background and Objectives: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid-storage disease caused by mutations in the CYP27A1. The purpose of this study is to determine the clinical characteristics, neuroimaging and mutation detect in a family with CTX systematically. Methods: Collecting history materials and detecting the routine clinical biochemical tests and imaging examination, and for the first time taking the whole body positron emission tomography (PET)-CT examination for probed in the world to research abnormal metabolism activities in CTX. To observe the effect of treatment with chenodeoxycholic acid (CDCA) and stains before and after the intervention, using serum lipid level detection and neuropsychological evaluation. Genetic testing was carried out to screen the nine exons and exon-intron boundaries about 200-300bq of CYP27A1. Results: A 37-year-old woman with typical clinical characteristics of CTX. Magnetic resonance imaging (MRI) of brain showed bilateral lesions in the dentate nucleus of the cerebellum, then, PET images revealed multiple abnormal hypermetabolism areas at distal tendon, and multifocal areas of hypometabolism in bilateral sides of cerebellar hemispheres, the frontal lobe and temporal lobe. Histopathology reveals accumulation of xanthoma cells and dispersed lipid crystal clefts in xanthomas. In genetic analysis, it shown an insertion of cytosine (77-78insC) located in the first exon of CYP27A1 in the proband. Conclusions: We found that a Chinese patient presented a typical clinical feature of CTX along with clear correlation on both structural and functional imaging had a novel mutation in the CYP27A1 gene.

16α-[18F]-fluoro-17ß-oestradiol ([18F]FES): A biomarker for imaging oestrogen receptor expression with positron emission tomography (PET)

International audience

Estudo combinado de PET com [11C]PiB e [18F]FDG na avaliação de doença de Alzheimer

A doença de Alzheimer (DA) têm-se constituído, nos últimos anos, num sério problema de saúde pública nas sociedades ocidentais, um reflexo de uma população cada vez mais envelhecida fruto da melhoria geral da assistência médica e das mudanças demográficas daí decorrentes. Tratando-se uma doença neurodegenerativa a DA conduz à perda de diversas faculdades cognitivas e carateriza-se pela redução progressiva de tamanho e número das células cerebrais, a par da formação de emaranhados neurofibrilares (NFTs) no seu interior e placas de β-amilóide (Aβ) no espaço exterior. Na última década, o diagnóstico da DA ganhou um importante aliado com a possibilidade de realização de Tomografia por Emissão de Positrões (PET) com o radiofármaco [11C]PiB que apresenta afinidade pelas placas de Aβ. Recentemente, foi também possível aumentar a confiança deste diagnóstico complementando-o com a avaliação do metabolismo cerebral da glicose através da sua conjugação, no mesmo protocolo PET com a [18F]FDG. No que concerne à realidade portuguesa, o ICNAS, uma unidade orgânica de investigação da Universidade de Coimbra focada na Utilização Biomédica das Ciências Nucleares, que inclui na sua estrutura uma unidade de produção radiofarmacêutica com ciclotrão, é um local privilegiado para a realização de PET cerebral com [11C]PiB. Desde Abril de 2012 até Julho de 2014 foram já realizados 107 estudos com [11C]PiB, dos quais 37 fizeram parte de estudos sequenciais onde o mesmo doente realizou o estudo combinado com [11C]PiB e [18F]FDG.

Exposição à radiação em exames de corpo inteiro de 18F-FDG PET-TC

O sistema de PET-TC resulta da combinação de duas modalidades de imagem médica: a Tomografia Computorizada (TC), que permite obter imagens anatómicas precisas, e a Tomografia por Emissão de Positrões (PET), que oferece imagens moleculares do corpo humano. Num exame hibrido de PET-TC, para além da exposição interna, o doente é também submetido a uma exposição externa devida à irradiação do mesmo por uma fonte externa, referente à aquisição dos dados de TC. Como tal, o exame de PET-TC tem associado um aumento da exposição para o doente [Huang, 2009], pelo que normalmente os scans de TC são adquiridos com baixa dose [Nunes,2011]. Pretende-se com este trabalho, estabelecer um método capaz de estimar a dose efetiva em exames de corpo inteiro de 18F-FDG PET-TC, uma vez que existem diversos métodos para realizar análise dosimétrica dos exames individuais de PET e de TC, e comparar os valores obtidos com os valores utilizados em outros países. Foram recolhidos dados de 24 pacientes que efetuaram exames de corpo inteiro de PET-TC com 18F-FDG no ICNAS, por questões de saúde e por necessidade própria, com o intuito de estimar a dose efetiva associada a esses exames. Para estimar a dose efetiva referente ao exame de TC recorreu-se ao valor de DLP, fornecido pelo equipamento de TC com controlo de qualidade em dia, e ao método dos coeficicientes de dose efetiva normalizados, proposto pela CE, obtendo-se um valor de dose de 4.75 mSv. A dose efetiva do exame de PET foi calculada com base nos valores da atividade no momento de aquisição das imagens e em coeficientes de dose para a PET, obtendo-se um valor de dose de 4.77 mSv. Concluiu-se que para os pacientes sujeitos ao exame de corpo inteiro de 18F-FDG PET-TC, foi registado um valor de dose de 9.47 mSv de dose efetiva. Este valor de dose efetiva para os exames de PET-TC é significativamente mais baixo comparativamente aos valores registados em vários estudos internacionais (13.65 mSv, 14.3 mSv, 18.85 mSv, 24.8 mSv, 25 mSv, 32.18 mSv), dos quais apenas no estudo de Brix um dos hospitais estudados regista um valor ligeiramente inferior, de 8.5 mSv. Com este estudo foi possível determinar o valor de exposição à radiação a que os pacientes do ICNAS se encontram sujeitos em exames de corpo inteiro de 18F-FDG PET-TC considerando as duas modalidades de imagem médica.

From ‘Bad’ to ‘Mad’: Labelling and Behaviour in Peter Shaffer’s Equus

The process of ‘labelling’ (whereby labels are socially imposed on a given behaviour by a given person) is an extensive and recurrent one in our society, as proved by the labelling of behaviours and people even into the literary text. In our analysis, we will try to show how applying one of two most different labels (psychopathic or psychotic) greatly influences our understanding of the existence of ‘evil’ or moral responsibility in the deeds of a person. To such end, we will use Peter Shaffer’s play Equus (1973), which requires both the characters in the play and the spectators to decide whether Alan Strang’s terrible crime is a result of evil or of insane behaviour: whether he is ‘mad’ or simply ‘bad’. We will try to evince the current social and cultural confusion between madness and evil, and how processes of medicalization or criminalization affect our understanding of those around us and those living in the books we read.

Evaluation of tumor recurrences after radical prostatectomy using 18F-Choline PET/CT and 3T multiparametric MRI without endorectal coil: a single center experience

The aim os this study is to evaluate and compare the utility of 18F-fluorocholine (18F-CH) PET/CT versus 3-Tesla multiparametric MRI (mpMRI) without endorectal coil to detect tumor recurrences in patients with biochemical relapse following radical prostatectomy (RP). Secondarily, to identify possible prognostic variables associated with mpMRI and 18F-CH PET/CT findings. Retrospective study of 38 patients who developed biochemical recurrence after RP between the years 2011 and 2015 at our institution. PET/CT and mpMRI were both performed within 30 days of each other in all patients. The PET/CT was reviewed by a nuclear medicine specialist while the mpMRI was assessed by a radiologist, both of whom were blinded to outcomes. The median prostate-specific antigen (PSA) value pre-MRI/PET-CT was 0.9 ng/mL (interquartile range 0.4–2.2 ng/mL). There were no differences in the detection rate between 18F-CH PET/CT and mpMRI for local recurrence (LR), lymph node recurrence (LNR) and bone metastases (BM). Separately, mpMRI and 18F-CH PET/CT were positive for recurrence in 55.2% and 52.6% of cases, respectively, and in 65.7% of cases when findings from both modalities were considered together. The detection of LR was better with combined mpMRI and choline PET/CT versus choline PET/CT alone (34.2% vs 18.4%, p = 0.04). Salvage treatment was modified in 22 patients (57.8%) based on the imaging findings. PSA values on the day of biochemical failure were significantly associated with mpMRI positivity (adjusted odds ratio (OR): 30.9; 95% confidence interval (CI): 1.5–635.8). Gleason score > 7 was significantly associated with PET/CT positivity (OR: 13.9; 95% CI: 1.5–125.6). A significant association was found between PSA doubling time (PSADT) (OR: 1.3; 95% CI: 1.0–1.7), T stage (OR: 21.1; 95% CI: 1.6–272.1), and LR. Multiparametric MRI and 18F-CH PET/CT yield similar detection rates for LR, LNR and pelvic BM. The combination of both imaging techniques provides a better LR detection versus choline PET/CT alone. The initially planned salvage treatment was modified in 57.8% of patients due to imaging findings. In addition to PSA values, Gleason score, T stage, and PSADT may provide valuable data to identify those patients that are most likely to benefit from undergoing both imaging procedures.