DPP-4 inhibitor dose selection according to manufacturer specifications:A Contemporary Experience From UK General Practice

Recently, 2 dipeptidyl peptidase-4 (DPP-4) inhibitors, sitagliptin and saxagliptin, adjusted dosing specification from creatinine clearance to glomerular filtration rate, more typically reported in routine laboratory tests. This cross-sectional study examines all DPP-4 inhibitor initiations that require dose adjustment and the dose selection using data from UK general practice. Results indicate that 34% of patients taking a nonlinagliptin DPP-4 inhibitor were given a higher dose and 11% a lower dose than specified in the Summary of Product Characteristics. This reinforces the deviation from Summary of Product Characteristics prescription of DPP-4 inhibitors identified in earlier studies despite improvement in compatibility with routine reporting. (C) 2019 The Authors. Published by Elsevier Inc

Exposure to point-of-sale displays and changes in susceptibility to smoking: findings from a cohort study of school students

Aims To investigate the association between frequency of visiting shops and noticing of tobacco point-of-sale (PoS) displays and the development of susceptibility to smoking, or smoking uptake, in secondary school students. Design Two surveys of a school based cohort study carried out in 2011 and 2012. Settings Nottinghamshire, UK. Participants A total of 2270 children aged 11–16 years from eight schools in Nottinghamshire. Measurements We investigated changes in susceptibility to smoking and smoking status in relation to frequency of visiting shops and noticing PoS displays and number of tobacco brands recognized, controlling for a range of potential confounders. Susceptibility to smoking was defined using a set of three questions covering intentions to try smoking, to smoke within the next year and likelihood of smoking if a best friend offered a cigarette. For the analysis we used multinomial logistic regression. Findings Among non-susceptible never smokers, noticing PoS displays more frequently was associated independently with an increased risk of becoming susceptible to smoking [adjusted relative risk ratio (RRR) = 1.74; 99% confidence interval (CI) = 1.13–2.69], but was not associated with smoking uptake. Recognizing a higher number of brands among non-susceptible never smokers doubled the risk of becoming susceptible to smoking and of becoming a smoker, but this did not have a significant effect on transition to smoking among susceptible never smokers. Frequency of noticing tobacco PoS displays was not associated significantly with smoking uptake among those who were susceptible never smokers at baseline. Conclusions Noticing tobacco point-of-sale displays more often and recognizing a higher number of tobacco brands is associated with an increased risk of becoming susceptible to smoking among adolescents in the United Kingdom, and recognizing a higher number of brands is associated positively with an increased risk of smoking uptake

Language Models for Ancient Greek

Το BERT είναι ένα προ-εκπαιδευμένο Γλωσσικό Μοντέλο το οποίο αναπτύχθηκε από την ομάδα της Google AI Language το 2018, που πετυχαίνει κορυφαίες επιδόσεις σε πολλά προβλήματα Επεξερασίας Φυσικής Γλώσσας. Είναι ένα επαναστατικό μοντέλο που μπο- ρεί να χρησιμοποιηθεί για την επίλυση σχεδόν οποιουδήποτε προβλήματος απατεί διαχείριση φυσικής γλώσσας. Ήδη, έχει εφαρμοσθεί με επιτυχία σε πληθώρα γλωσσών πέρα από τα Αγγλικά, όπως Γαλλικά, Ισπανικά, αλλά ακόμη και σε Ελληνικά και Λατινικά. Ο στόχος αυτής της πτυχιακής ήταν η δημιουργία ενός Γλωσσικού Μοντέλου για την Αρχαία Ελληνική γλώσσα βασισμένο σε μια αρχιτεκτονική τύπου BERT, και στη συνέχεια η εφαρμογή του σε κάποιο πρόβλημα, συγκεκριμένα στην αναγώριση ετικετών μέρους του λόγου. Υπήρχαν δύο βασικά βήματα που έπρεπε να πραγματοποιηθούν για να αναπτυ- χθεί το μοντέλο. Αρχικά, υπήρξε το κομμάτι της συλλογής δεδομένων, και στη συνέχεια η εκπαίδευση ενός γλωσσικού μοντέλου με τα δεδομένα που αποκτήθηκαν. Όσον αφορά το κομμάτι της συλλογής δεδομένων, πραγματοποιήθηκε αρκετή έρευνα προκειμένου να βρεθούν διαθέσιμες στο κοινό πηγές με δεδομένα απλού κειμένου, αλλά δεν βρέθηκαν πολλά. Συνολικά, ο όγκος των δεδομένων που μπορέσαμε να συλλέξουμε ήταν λίγο μικρότερος από 450 MB. Αυτό ήταν ένα σημαντικό πρόβλημα, καθώς τα πε- ρισσότερα μοντέλα που βασίζονται σε αρχιτεκτονική BERT είχαν εκπαιδευτεί με όγκους δεδομένων της κλίμακας των 30-50 GB. Όσον αφορά το κομμάτι της εκπαίδευσης, η προ-εκπαίδευση και το μοντέλο RoBERTa επιλέχθηκαν ως πλαίσιο για το Μοντέλο της Αρχαίας Ελληνικής Γλώσσας, αφού έχουν επιδείξει καλύτερες επιδόσεις από άλλες παραλλαγές του BERT. Ο στόχος εκπαίδευσης ήταν αυτός του Masked Language Modeling με δυναμική μάσκα. Απροσδόκητα, τα αποτελέσματα είχαν δύο πλευρές. Από την μία πλευρά, το Γλωσσικό Μοντέλο αδυνατούσε να μάθει εις βάθος την Αρχαία Ελληνική Γλώσσα διότι δεν εκπαιδευόταν με αρκετά δεδομένα. Δοκιμάστηκαν πολλές ιδέες, όπως η μείωση του μεγέθους του μοντέλου και ο συντονισμός των υπερπαραμέτρων με μπαεσιανή βελτιστοποίηση, αλλά καμία δεν έδωσε καλά αποτελέσματα. Από την άλλη πλευρά, όταν το εφαρμόσαμε στο πρόβλημα αναγνώρισης ετικετών μέρους του λόγου, τα αποτέσματα είναι αρκετά καλά, κάτι το οποίο συνιστά πως το μοντέλο είχε όντως κατανοήσει ορισμένες πτυχές της Αρχαίας Ελληνικής Γλώσσας. Ρίχνοντας μια ματιά στις καμπύλες εκπαίδευσης, μπορούμε να δούμε ότι το μοντέλο σίγουρα μαθαίνει κάτι, καθώς η αντικειμενική συνάρτηση συνεχίζει να μειώνεται, μέχρι ένα σημείο στο οποίο συγκλίνει. Πιστεύουμε ότι αυτή η συμπεριφορά οφείλεται στην έλλειψη ενός πολύ μεγαλύτερου σώματος δεδομένων. Εάν διατεθούν περισσότερα δεδομένα στο μέλλον, σίγουρα θα άξιζε να δοκιμαστεί ξανά αυτή η προσέγγιση. Γι' αυτό τον λόγο, ο κώδικας για τη λήψη των δεδομένων και την εκπαίδευση ενός μοντέλου διατίθεται στη ηλεκτρονική διεύθυνση https://github.com/AndrewSpano/BSc-Thesis.BERT is a pre-trained Language Model introduced by Google AI Language in 2018, that manages to achieve state-of-the-art results on many downstream tasks. It is a revolutionary model that can be used to tackle almost any NLP task. It has also been successfully applied to other languages apart from English, such as French, Spanish and even Greek and Latin. The goal of this thesis was to create a Language Model for the Ancient Greek language based on a BERT-like architecture, and then fine-tune it to some downstream task, specifically Part-of-Speech tagging. There were two main steps that needed to be taken in order to develop the model. First, there was the data collection part, and then training a language model with the data acquired. Regarding the data collection part, a lot of research was done in order to find publicly available sources with plain-text data, but not much was found. In total, the amount of data that we were able to collect was a bit less than 450 MB. This was a major problem, as most BERT-like models had been trained on corpora in the scale of 30-50 GB. Regarding the training part, the RoBERTa pre-training and model were chosen as a frame- work for the Ancient Greek Language Model, since it had demonstrated better performance than other variants. The training objective was that of Masked Language Modelling with dynamic masking. Unexpectedly, the results were two-fold. One the one hand, the Language Model kept underfitting due to the fact that it wasn’t seeing enough data. Many ideas were tried such as reducing the model size and tuning the hyperparameters with bayesian optimization, but none yielded good results. On the other hand, when fine-tuning for PoS Tagging, the results were reasonably good, which suggests that the Language Model has learnt important aspects of the Ancient Greek language. By taking a look at the training curves, we can see that the model is definitely learning something as the loss keeps decreasing, up until a point where it converges. We strongly believe that this underfitting effect is due to the lack of a much larger corpora. If more data is made available in the future, it would be definitely worth trying out again this approach. That’s why the code for downloading the data and training a model is made available at https://github.com/AndrewSpano/BSc-Thesis

Tuning Ionic and Electronic Conductivities in the "Hollow" Perovskite { en}MAPbI₃

The recently developed family of 3D halide perovskites with general formula (A)1-x(en)x(M)1-0.7x(I)3-0.4x (A = MA, FA; M = Pb2+, Sn2+ en = ethylenediammonium), often referred to as "hollow"perovskites, exhibits exceptional air stability and crystallizes in the high symmetry α phase at room temperature. These properties are counterintuitive, considering that these structures include the large divalent en cation charge-compensated by vacancies of Pb cations and I anions. Moreover, the understanding of their transport behavior is incomplete. To provide new insights into the ionic and electronic transport properties of these "hollow"perovskites, we performed DC polarization experiments and ab initio calculations on the {en}MAPbI3 material. We observe large variations of ionic and electronic conductivities with en concentration, which can be explained by charge and site arguments in conjunction with trapping effects. The latter is reflected by the increase of the activation energies for iodide ion transport with higher en content that we observe from both experimental and computational results. The connection between these transport phenomena and the stability of "hollow"perovskite materials and devices is discussed. </p

Alternative Organic Spacers for More Efficient Perovskite Solar Cells Containing Ruddlesden-Popper Phases

The halide perovskite Ruddlesden-Popper (RP) phases are a homologous layered subclass of solution-processable semiconductors that have aroused great attention, especially for developing long-term solar photovoltaics. They are defined as (A′)2(A)n-1PbnX3n+1 (A′ = spacer cation, A = cage cation, and X = halide anion). The orientation control of low-temperature self-assembled thin films is a fundamental issue associated with the ability to control the charge carrier transport perpendicular to the substrate. Here we report new chemical derivatives designed from a molecular perspective using a novel spacer cation 3-phenyl-2-propenammonium (PPA) with conjugated backbone as a low-temperature strategy to assemble more efficient solar cells. First, we solved and refined the crystal structures of single crystals with the general formula (PPA)2(FA0.5MA0.5)n-1PbnI3n+1 (n = 2 and 3, space group C2) using X-ray diffraction and then used the mixed halide (PPA)2(Cs0.05(FA0.88MA0.12)0.95)n-1Pbn(I0.88Br0.12)3n+1 analogues to achieve more efficient devices. While forming the RP phases, multiple hydrogen bonds between PPA and inorganic octahedra reinforce the layered structure. For films we observe that as the targeted layer thickness index increases from n = 2 to n = 4, a less horizontal preferred orientation of the inorganic layers is progressively realized along with an increased presence of high-n or 3D phases, with an improved flow of free charge carriers and vertical to substrate conductivity. Accordingly, we achieve an efficiency of 14.76% for planar p-i-n solar cells using PPA-RP perovskites, which retain 93.8 ± 0.25% efficiency with encapsulation after 600 h at 85 °C and 85% humidity (ISOS-D-3)

Hausdorff spectrum of harmonic measure

For every non-elementary hyperbolic group, we show that for every random walk with finitely supported admissible step distribution, the associated entropy equals the drift times the logarithmic volume growth if and only if the corresponding harmonic measure is comparable with Hausdorfff measure on the boundary. Moreover, we introduce one parameter family of probability measures which interpolates a Patterson-Sullivan measure and the harmonic measure, and establish a formula of Hausdorff spectrum (multifractal spectrum) of the harmonic measure. We also give some finitary versions of dimensional properties of the harmonic measure

Retail Price and Point of Sale Display of Tobacco in the UK: A Descriptive Study of Small Retailers

Background: Since the implementation of the 2002 Tobacco Advertising and Promotion Act, point-of-sale (PoS) tobacco displays are one of few remaining means of communication between the tobacco industry and customers in the UK. This study aimed to explore the characteristics of tobacco displays in a UK city, and particularly to assess the tobacco prices and promotional offers, types and pack sizes on display. Methods: Digital pictures of PoS displays were taken in 117 small retail shops in Nottingham in mid 2010. Data were analysed using Windows Photo Gallery software and SPSS version 16. Results: Just over half (52%) of cigarette packs on display were packs of 20, and 43 % packs of 10. Cigarette prices differed substantially between brands, ranging from £4.19 to £6.85 for 20-packs, and from £2.12 to £3.59 for 10-packs. Forty four percent of cigarette packs and 40 % of RYO (Roll-Your-Own) tobacco pouches, almost exclusively lower priced brands, were displayed with a pricemark, implying a promotional price offer. Eighty percent of 20-pack cigarette brand or brand variants on sale were priced below the EU-defined Most Popular Price Category (MPPC) for the UK in 2010; 45 % were priced below the Weighted Average Price (WAP), which replaced the MPPC in 2011. Conclusion: PoS displays communicate value by displaying a high proportion of lower cost brands, and smaller and hence lower-cost packs, and by displaying price discounts on packs. The MPPC substantially overestimated the prices at whic

The relation between cigarette price and hand-rolling tobacco consumption in the UK: an ecological study

OBJECTIVES: Cigarette price increases reduce smoking prevalence but as a tobacco control policy are undermined by the availability of lower cost alternatives such as hand-rolling tobacco. The aim of this descriptive study is to explore time trends in the price of manufactured cigarettes and hand-rolling tobacco, and in the numbers of people who smoke these products, over recent years in the UK. SETTINGS AND PARTICIPANTS: UK. OUTCOME MEASURES: Trends in the most popular price category (MPPC) data for cigarettes and hand-rolling tobacco from 1983 to 2012 adjusted for inflation using the Retail Price Index, and trends in smoking prevalence and the proportion of smokers using hand-rolling tobacco from 1974 to 2010. RESULTS: After adjustment for inflation, there was an increase in prices of manufactured cigarettes and hand-rolling tobacco between 1983 and 2012. Between 1974 and 2010, the prevalence of smoking fell from 45% to 20%, and the estimated total number of smokers from 25.3 to 12.4 million. However the number of people smoking hand-rolling tobacco increased from 1.4 to 3.2 million, and MPPC cigarette price was strongly correlated with number of people smoking hand-rolling tobacco. CONCLUSIONS: Although the ecological study design precludes conclusions on causality, the association between increases in manufactured cigarette price and the number of people smoking hand-rolling tobacco suggests that the lower cost of smoking hand-rolling tobacco encourages downtrading when cigarette prices rise. The magnitude of this association indicates that the lower cost of hand-rolling tobacco seriously undermines the use of price as a tobacco control measure