206 research outputs found
The Compositional Structure of Bayesian Inference
Bayes\u27 rule tells us how to invert a causal process in order to update our beliefs in light of new evidence. If the process is believed to have a complex compositional structure, we may observe that the inversion of the whole can be computed piecewise in terms of the component processes. We study the structure of this compositional rule, noting that it relates to the lens pattern in functional programming. Working in a suitably general axiomatic presentation of a category of Markov kernels, we see how we can think of Bayesian inversion as a particular instance of a state-dependent morphism in a fibred category. We discuss the compositional nature of this, formulated as a functor on the underlying category and explore how this can used for a more type-driven approach to statistical inference
L'engagement du père Georges-Henri Lévesque dans la modernité canadienne-française, 1932-1962 : contribution à l'histoire intellectuelle du catholicisme et de la modernité au Canada français
Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2015-2016Entre 1932 et 1962, l'engagement du père Georges-Henri Lévesque, o.p., dans la modernité canadienne-française se décline sur quatre plans principaux: modernité économique, modernité sociale, modernité épistémologique et modernité culturelle. À chacun de ces plans correspond un épisode plus ou moins conflictuel de la carrière intellectuelle du père Lévesque. Dans cette thèse, nous analysons ces épisodes en les inscrivant dans la tension générale entre l'Église et la société moderne depuis la Révolution française. Face aux changements qui affectent le Canada français à compter de la Crise des années 1930, l'engagement du dominicain consiste surtout en un effort de résolution des contradictions apparentes de la modernité. Dans la crise économique des années 1930, Lévesque se fait promoteur de la coopération pour conjuguer les intérêts individuels au bien de la collectivité. Sur le plan social, anticipant le divorce de l'Église et de la société canadienne-française, il défend la non-confessionnalité des coopératives comme un moyen de les réconcilier. Doyen de la Faculté des sciences sociales de l'Université Laval à partir de 1938, il s'efforce de distinguer la science sociale de la doctrine sociale catholique pour mieux les unir en vue d'une action proprement catholique sur la société canadienne-française. Membre de la Commission royale d'enquête sur l'avancement des arts, des lettres et des sciences au Canada au tournant des années 1950, le père Lévesque distingue entre nationalisme et patriotisme pour mieux repenser la référence nationale canadienne-française en fonction des impératifs de la modernité culturelle. À travers l'analyse de ces moments marquants, nous tentons non seulement de mieux comprendre l'évolution de la pensée de Georges-Henri Lévesque, mais aussi de mettre au jour les stratégies qu'il déploie pour faire valoir ses idées dans l'entrelacs épineux des champs clérical, universitaire et politique dans lequel il se trouve engagé. Au fil de ce récit se révèle une sensibilité religieuse résolument optimiste, tournée vers l'avenir et valorisant l'engagement de tous les croyants hic et nunc en fonction d'une analyse rationnelle du monde contemporain.Between 1932 and 1962, Father Georges-Henri Lévesque’s, O.P., implication in French Canadian modern society was based on four main fronts: economic, social, epistemological and cultural modernity. Each of these fronts corresponds to a more or less conflictual period in Father Lévesque’s intellectual career. These periods will be analysed by interpreting them in the context of the general tensions between the Church and modern society since the French Revolution. Faced with the changes that affected French Canada since the Great Depression, Father Lévesque’s efforts consisted mainly in resolving the apparent contradictions of the modern era. During the economic crisis of the 1930s, Lévesque promoted the co-operative movement as a way of reconciling individual interests for the greater good of the community. On the social front, anticipating the separation of French Canadian society from the Church, Lévesque supported neutral (non-confessionnelles) co-operative organisations as a way of reunifying both sides. Dean of Laval University’s Faculty of Social Sciences as of 1938, Lévesque strived to differentiate social sciences from religious instruction in the interest of better uniting both teachings. This was done in the hope of attempting to solve problems afflicting French Canadian society in a most Catholic manner. Member of the Royal Commission on National Development in the Arts, Letters and Sciences in Canada in the early 1950s, Father Lévesque made the distinction between nationalism and patriotism, in turn provoking the transformation of French Canadian nationalism according to the imperatives of cultural modernity. Through the analysis of these defining moments, this thesis not only tries to improve understanding of the evolution of Father George-Henri Lévesque’s thought, but also to bring light to the strategies he used to implement his ideas in the context of the sensitive, interweaved clerical, academic and political fields he was engaged in. Throughout the dissertation, Father Lévesque’s religious sensibility is analysed. It is an optimistic, forward-looking approach valuing the involvement of all believers, hic et nunc, based on the rational analysis of the contemporary world
Reflect on this
Abstract In this article we reflect on reflection. To do this, we share examples of pedagogic approaches used in undergraduate performance programmes at York St Joh
Cheater Detection in SPDZ Multiparty Computation
In this work we revisit the SPDZ multiparty computation protocol by Damgård et al. for securely computing a function in the presence of an unbounded number of dishonest parties. The SPDZ protocol is distinguished by its fast performance. A downside of the SPDZ protocol is that one single dishonest party can enforce the computation to fail, meaning that the honest parties have to abort the computation without learning the outcome, whereas the cheating party may actually learn it. Furthermore, the dishonest party can launch such an attack without being identified to be the cheater. This is a serious obstacle for practical deployment: there are various reasons for why a party may want the computation to fail, and without cheater detection there is little incentive for such a party not to cheat. As such, in many cases, the protocol will actually fail to do its job. In this work, we enhance the SPDZ protocol to allow for cheater detection: a dishonest party that enforces the protocol to fail will be identified as being the cheater. As a consequence, in typical real-life scenarios, parties will actually have little incentive to cheat, and if cheating still takes place, the cheater can be identified and discarded and the computation can possibly be re-done, until it succeeds. The challenge lies in adding this cheater detection feature to the original protocol without increasing its complexity significantly. In case no cheating takes place, our new protocol is as efficient as the original SPDZ protocol which has no cheater detection. In case cheating does take place, there may be some additional overhead, which is still reasonable in size though, and since the cheater knows he will be caught, this is actually unlikely to occur in typical real-life scenarios
Hepatitis B virus infection among different sex and age groups in Pakistani Punjab
<p>Abstract</p> <p>Background</p> <p>Hepatitis B virus (HBV) infection is a serious health problem in the developing countries including Pakistan. Various risk factors are responsible for the spread of this infectious disease. Prevalence of HBV infection in apparently suspected individual of Punjab province of Pakistan was analyzed during January 2008 to December 2010. Current study was aimed to investigate the epidemiology and risk factors of HBV infection.</p> <p>Methodology</p> <p>Four thousand eight hundred and ninety patients suffering from chronic liver disease were screened for the presence of HBV DNA using qualitative Real Time PCR methodology to confirm their status of infection. A predesigned standard questionnaire was filled for all the patients that included information about the possible risk factors.</p> <p>Results</p> <p>A total of 4890 ELISA positive patients were screened for Hepatitis B virus infection. Of these 3143 were positive for HBV, includes 68.15% males and 31.85% females. Male were observed to be more frequently infected as compared to the female with a positivity ratio of 2.14: 1. The rate of infection increases with the passage of time in the course of three years. Highest frequency of infection was found in the age of 21-30 was 34.93% followed by 23.83% in 31-40. Only (13.39%) were belonging to the age group 11-20 year. The rate of infection declines with increasing age as shown by age groups 41-50 (16.13%) and 51-60 (7.09%). While children aged 0-10 and very old >60 age groups were very less frequently 1.49% and 1.65% infected respectively. Important risk factors contributing to HBV spread include barber risk (23.60%), blood transfusion (4.04%), History of injection 26.19%, Reuse of syringes 26.60%, dental risk (11.20%) and surgical procedure (4.26%). Among the entire respondents trend sharing personal items was very common. History of injection, barber risk, surgery and dental procedure and reuse of syringes appear as major risk factors for the transmission.</p> <p>Conclusion</p> <p>Male were more frequently exposed to the risk factors as compared to female. Similarly the younger age group had high rate of infection as compared to the children's and the older age groups. Reuse of syringes', barber risk and History of injection were main risk identified during the present study. To lower HBV transmission rate Government should take aggressive steps towards massive awareness and vaccination programs to decrease the burden of HBV from the Punjab province of Pakistan.</p
Liver Volumetry Plug and Play: Do It Yourself with ImageJ
AB - BACKGROUND: A small remnant liver volume is an important risk factor for posthepatectomy liver failure and can be predicted accurately by computed tomography (CT) volumetry using radiologic image analysis software. Unfortunately, this software is expensive and usually requires support by a radiologist. ImageJ is a freely downloadable image analysis software package developed by the National Institute of Health (NIH) and brings liver volumetry to the surgeon's desktop. We aimed to assess the accuracy of ImageJ for hepatic CT volumetry. METHODS: ImageJ was downloaded from http://www.rsb.info.nih.gov/ij/ . Preoperative CT scans of 15 patients who underwent liver resection for colorectal cancer liver metastases were retrospectively analyzed. Scans were opened in ImageJ; and the liver, all metastases, and the intended parenchymal transection line were manually outlined on each slice. The area of each selected region, metastasis, resection specimen, and remnant liver was multiplied by the slice thickness to calculate volume. Volumes of virtual liver resection specimens measured with ImageJ were compared with specimen weights and calculated volumes obtained during pathology examination after resection. RESULTS: There was an excellent correlation between the volumes calculated with ImageJ and the actual measured weights of the resection specimens (r(2) = 0.98, p < 0.0001). The weight/volume ratio amounted to 0.88 +/- 0.04 (standard error) and was in agreement with our earlier findings using CT-linked radiologic software. CONCLUSION: ImageJ can be used for accurate hepatic CT volumetry on a personal computer. This application brings CT volumetry to the surgeon's desktop at no expense and is particularly useful in cases of tertiary referred patients, who already have a proper CT scan on CD-ROM from the referring institution. Most likely the discrepancy between volume and weight results from exsanguination of the liver after resectio
Flavonoid and lignan intake in relation to bladder cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study
Item does not contain fulltextBACKGROUND: There is growing evidence of the protective role of dietary intake of flavonoids and lignans on cancer, but the association with bladder cancer has not been thoroughly investigated in epidemiological studies. We evaluated the association between dietary intakes of total and subclasses of flavonoids and lignans and risk of bladder cancer and its main morphological type, urothelial cell carcinoma (UCC), within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. METHODS: A cohort of 477 312 men and women mostly aged 35-70 years, were recruited in 10 European countries. At baseline, dietary flavonoid and lignan intakes were estimated using centre-specific validated questionnaires and a food composition database based on the Phenol-Explorer, the UK Food Standards Agency and the US Department of Agriculture databases. RESULTS: During an average of 11 years of follow-up, 1575 new cases of primary bladder cancer were identified, of which 1425 were UCC (classified into aggressive (n=430) and non-aggressive (n=413) UCC). No association was found between total flavonoid intake and bladder cancer risk. Among flavonoid subclasses, significant inverse associations with bladder cancer risk were found for intakes of flavonol (hazard ratio comparing fifth with first quintile (HRQ5-Q1) 0.74, 95% confidence interval (CI): 0.61-0.91; P-trend=0.009) and lignans (HRQ5-Q1 0.78, 95% CI: 0.62-0.96; P-trend=0.046). Similar results were observed for overall UCC and aggressive UCC, but not for non-aggressive UCC. CONCLUSIONS: Our study suggests an inverse association between the dietary intakes of flavonols and lignans and risk of bladder cancer, particularly aggressive UCC
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
- …