Uncertainty quantification methods for neural networks pattern recognition

On-line monitoring techniques have attracted increasing attention as a promising strategy for improving safety, maintaining availability and reducing the cost of operation and maintenance. In particular, pattern recognition tools such as artificial neural networks are today largely adopted for sensor validation, plant component monitoring, system control, and fault-diagnostics based on the data acquired during operation. However, classic artificial neural networks do not provide an error context for the model response, whose robustness remains thus difficult to estimate. Indeed, experimental data generally exhibit a time/space-varying behaviour and are hence characterized by an intrinsic level of uncertainty that unavoidably affects the performance of the tools adopted and undermines the accuracy of the analysis. For this reason, the propagation of the uncertainty and the quantification of the so called margins of uncertainty in output are crucial in making risk-informed decision. The current study presents a comparison between two different approaches for the quantification of uncertainty in artificial neural networks. The first technique presented is based on the error estimation by a series association scheme, the second approach couples Bayesian model selection technique and model averaging into a unified framework. The efficiency of these two approaches are analysed in terms of their computational cost and predictive performance, through their application to a nuclear power plant fault diagnosis system

Robust on-line diagnosis tool for the early accident detection in nuclear power plants

© 2019 Any loss of coolant accident mitigation strategy is necessarily bound by the promptness of the break detection as well as the accuracy of its diagnosis. The availability of on-line monitoring tools is then crucial for enhancing safety of nuclear facilities. The requirements of robustness and short latency implied by the necessity for fast and effective actions are undermined by the challenges associated with break prediction during transients. This study presents a novel approach to tackle the challenges associated with the on-line diagnostics of loss of coolant accidents and the limitations of the current state of the art. Based on the combination of a set of artificial neural network architectures through the use of Bayesian statistics, it allows to robustly absorb different sources of uncertainty without requiring their explicit characterization in input. It provides the quantification of the output confidence bounds but also enhances of the model response accuracy. The implemented methodology allows to relax the need for model selection as well as to limit the demand for user-defined analysis parameters. A numerical case-study entailing a 220 MWe heavy-water reactor is analysed in order to test the efficiency of the developed computational tool

Pyrethrins In Soil and Water From Selected Pyrethrum Growing Areas In Nakuru County, Kenya

Introduction: Pyrethrum also known as Chrysanthemum is a plant from which compounds known as pyrethrins are derived. The pyrethrins have  been used for many years as insecticides. Incidentally due to their high instability they have slowly been replaced by synthetic pyrethroids.  Pyrethrins are generally regarded as safe compared to the pyrethroids. However, the amounts released into the environment have not been well documented especially in pyrethrum growing regions.Objective:  The aim of the study was to determine the concentration of pyrethrins that come from pyrethrum plants and released into the  environment through their use as insecticides, thus, into drinking water and soil, in pyrethrum growing regions in Kenya.Methodology: Quantification to amounts of pyrethrins from pyrethrum plants, in soil and water bodies in and around pyrethrum farms in Kiambogo and Naivasha (Nakuru County). The study was carried out using High Performance Liquid Chromatography (HPLC). Water samples (0.5L) were collected from the following water bodies: rivers, streams, dams, wells and boreholes near or within pyrethrum farms.Conclusion: It was established that, the quantity of pyrethrins present in water and soil samples werebelow detectable levels within the WHO recommended range. Hence safe for the environment,more so for the farmers and the people living around pyrethrum farms. Key words: Pyrethrum, pyrethrins, chromatography, water, soil

The Potential of Citizen-Driven Monitoring of Freshwater Snails in Schistosomiasis Research

Schistosomiasis is a tropical parasitic disease affecting more than 200 million people worldwide, predominantly in Africa. The World Health Organization recently highlighted the importance of targeted control of the freshwater snails acting as intermediate hosts for the parasites causing schistosomiasis. However, because of a shortage of trained experts and resources, detailed information on spatiotemporal snail distributions, which is needed for targeted control measures, is often missing. We explore the potential of citizen science to build these much-needed datasets through fine-grained, frequent snail sampling. We trained a network of 25 citizen scientists to weekly report on snail host abundances in 77 predefined water contact sites in and around Lake Albert (western Uganda). Snail abundance, together with marked GPS locations, water chemistry parameters, and photographs of the identified snails are recorded and submitted using the freely available mobile phone application KoBoToolbox. Trained researchers then engage in remote, semi-automatic validation of the submissions, after which there is an opportunity to provide targeted feedback to the citizen scientists. Five months after the operationalisation of the network, a total of 570 reports were submitted and personalized feedback was given, resulting in lasting improvements in subsequent reporting and snail genus identification. The preliminary results show the possibility of citizen science to independently obtain reliable data on the presence of schistosome snail hosts. We therefore argue that citizen-driven monitoring on a high spatiotemporal resolution could help to generate the much-needed data to support local targeted snail control measures in remote and/or resource-limited environments

Students Take Lead to Educate Faculty on the Use of Sex and Gender Terminology in Pre-clinical Courses

TOP WINNER Student leaders in the Lesbian, Gay, Bisexual and Transgender People in Medicine student run organization at the Medical College of Wisconsin noticed that curricular language around sex and gender was absent and/or incorrect in the pre-clinical medical school (M1/M2) courses. After reaching out to the M2 Endocrine/Repro Unit course director, students prepared a report to present to all M1/M2 Course Directors. Objectives: One goal of the report was to “educate the educators” so that faculty would have better understanding of the distinction between sex and gender. Ultimately this would translate to the students and improve overall future patient care. Methods: A presentation was developed and given at the quarterly M1/M2 course director meeting (Fall 2019). Information included statistics from the 2015 US Transgender Survey which underscored that ignorance surrounding sex versus gender terminology could result in an environment in which patients do not seek care. The student presentation comprehensively explained the definitions of sex, gender, cisgender and transgender. Course directors were given action items to evaluate their courses and afirm that terms were used appropriately. Student leaders provided contact information for faculty feedback. Conclusions/Impact: In February 2020, students reported of changes in some courses. For example, the M2 cardiovascular unit led off the session on women and heart disease with sex and gender definitions provided by students. Cardiovascular risks of hormonal therapy for transgender patients was included. Students noted that language around sex and gender in the M2 endocrine-repro unit was consistently correct (female not woman when discussing XX fetus). A M1 pharmacology lecture included the student\u27s definition slide as prelude to discussion of male/female differences in drug response. With little effort, students played an integral role in improving curricular content related to sex and gender medicine and further supporting the model that students are important drivers of change.https://jdc.jefferson.edu/sexandgenderhealth/1019/thumbnail.jp

Extent and Dynamics of Polymorphism in the Malaria Vaccine Candidate Plasmodium falciparum Reticulocyte-Binding Protein Homologue-5 in Kalifabougou, Mali

Reticulocyte-binding homologues (RH) are a ligand family that mediates merozoite invasion of erythrocytes in Plasmodium falciparum. Among the five members of this family identified so far, only P. falciparum reticulocyte-binding homologue-5 (PfRH5) has been found to be essential for parasite survival across strains that differ in virulence and route of host-cell invasion. Based on its essential role in invasion and early evidence of sequence conservation, PfRH5 has been prioritized for development as a vaccine candidate. However, little is known about the extent of genetic variability of RH5 in the field and the potential impact of such diversity on clinical outcomes or on vaccine evasion. Samples collected during a prospective cohort study of malaria incidence conducted in Kalifabougou, in southwestern Mali, were used to estimate genetic diversity, measure haplotype prevalence, and assess the within-host dynamics of PfRH5 variants over time and in relation to clinical malaria. A total of 10 nonsynonymous polymorphic sites were identified in the Pfrh5 gene, resulting in 13 haplotypes encoding unique protein variants. Four of these variants have not been previously observed. Plasmodium falciparum reticulocyte-binding homologue-5 had low amino acid haplotype (h = 0.58) and nucleotide (π = 0.00061) diversity. By contrast to other leading blood-stage malaria vaccine candidate antigens, amino acid differences were not associated with changes in the risk of febrile malaria in consecutive infections. Conserved B- and T-cell epitopes were identified. These results support the prioritization of PfRH5 for possible inclusion in a broadly cross-protective vaccine

Geographical and temporal distribution of human giardiasis in Ontario, Canada

BACKGROUND: Giardia is the most frequently identified intestinal parasite in North America. Although information on geographical distribution of giardiasis is critical in identifying communities at high risk, little has been done in this area. Therefore, the objective of this study was to investigate the geographical and temporal distribution of human giardiasis in Ontario in order to identify possible high risk areas and seasons. Two spatial scales of analyses and two disease measures were used with a view to identifying the best of each in assessing geographical patterns of giardiasis in Ontario. Global Moran's I and Moran Local Indicators of Spatial Associations were used to test for evidence of global and local spatial clustering, respectively. RESULTS: There were seasonal patterns with summer peaks and a significant (P < 0.001) decreasing temporal trend. Significant (P < 0.05) global spatial clustering of high rates was observed at the Census Sub-division spatial scale but not at the Census Division scale. The Census Sub-division scale was a better scale of analyses but required spatial empirical Bayesian smoothing of the rates. A number of areas with significant local clustering of giardiasis rates were identified. CONCLUSIONS: The study identified spatial and temporal patterns in giardiasis distribution. This information is important in guiding decisions on disease control strategies. The study also showed that there is benefit in performing spatial analyses at more than one spatial scale to assess geographical patterns in disease distribution and that smoothing of disease rates for mapping in small areas enhances visualization of spatial patterns

Growth rates and the prevalence and progression of scoliosis in short-statured children on Australian growth hormone treatment programmes

STUDY DESIGN AND AIM: This was a longitudinal chart review of a diverse group (cohort) of patients undergoing HGH (Human Growth Hormone) treatment. Clinical and radiological examinations were performed with the aim to identify the presence and progression of scoliosis. METHODS AND COHORT: 185 patients were recruited and a database incorporating the age at commencement, dose and frequency of growth hormone treatment and growth charts was compiled from their Medical Records. The presence of any known syndrome and the clinical presence of scoliosis were included for analysis. Subsequently, skeletally immature patients identified with scoliosis were followed up over a period of a minimum four years and the radiologic type, progression and severity (Cobb angle) of scoliosis were recorded. RESULTS: Four (3.6%) of the 109 with idiopathic short stature or hormone deficiency had idiopathic scoliosis (within normal limits for a control population) and scoliosis progression was not prospectively observed. 13 (28.8%) of 45 with Turner syndrome had scoliosis radiologically similar to idiopathic scoliosis. 11 (48%) of 23 with varying syndromes, had scoliosis. In the entire cohort, the growth rates of those with and without scoliosis were not statistically different and HGH treatment was not ceased because of progression of scoliosis. CONCLUSION: In this study, there was no evidence of HGH treatment being responsible for progression of scoliosis in a small number of non-syndromic patients (four). An incidental finding was that scoliosis, similar to the idiopathic type, appears to be more prevalent in Turner syndrome than previously believed

SOSORT consensus paper: school screening for scoliosis. Where are we today?

This report is the SOSORT Consensus Paper on School Screening for Scoliosis discussed at the 4th International Conference on Conservative Management of Spinal Deformities, presented by SOSORT, on May 2007. The objectives were numerous, 1) the inclusion of the existing information on the issue, 2) the analysis and discussion of the responses by the meeting attendees to the twenty six questions of the questionnaire, 3) the impact of screening on frequency of surgical treatment and of its discontinuation, 4) the reasons why these programs must be continued, 5) the evolving aim of School Screening for Scoliosis and 6) recommendations for improvement of the procedure