Bayesian hierarchical modelling of bacteria growth

Bacterial growth models are commonly used in food safety. Such models permit the prediction of microbial safety and the shelf life of perishable foods. In this paper, we study the problem of modelling bacterial growth when we observe multiple experimental results under identical environmental conditions. We develop a hierarchical version of the Gompertz equation to take into account the possibility of replicated experiments and we show how it can be fitted using a fully Bayesian approach. This approach is illustrated using experimental data from Listeria monocytogenes growth and the results are compared with alternative models. Model selection is undertaken throughout using an appropriate version of the deviance information criterion and the posterior predictive loss criterion. Models are fitted using WinBUGS via R2WinBUGS

Cuaderno de obra digital y control administrativo en ejecución de obras públicas en una entidad de Huamalíes, 2023

El presente proyecto de investigación fue desarrollado en el departamento de Huánuco, en la Provincia de Huamalíes con el objetivo de determinar la relación que existe entre el cuaderno de obra digital y el control administrativo en ejecución de obras públicas en una entidad de Huamalíes, 2023. La investigación desarrollada fue de enfoque cuantitativo tipo básica, de diseño no experimental, transversal, descriptivo y correlacional, de método hipotético deductivo. La población estará compuesta por 57 trabajadores, la muestra fue censal. La técnica utilizada fue la encuesta y como instrumento el cuestionario, de este último, se elaboró dos cuestionarios, uno por cada variable, durante la prueba piloto se evidenció que el instrumento para la primera variable tiene una fiabilidad de 0.836, mientras que para la segunda variable es de 0.935, asimismo el 78.95% de la población respecto a la primera variable, consideran que su uso es aceptable y el 73.68% respecto a la segunda variable, lo consideran aceptable. Con una población >50 y los resultados de la prueba de normalidad, se dedujo que son pruebas no paramétricas, mediante la correlación de Pearson, se obtuvo como resultados: r = .692 y p<0.001, infiriendo que existe una relación positiva media entre las variables. Los resultados reflejaron la correlación de la variable cuaderno de obra digital con las dimensiones control de calidad, control de producción y control de personal de obra

Bayesian modelling of bacterial growth for multiple populations

Bacterial growth models are commonly used for the prediction of microbial safety and the shelf life of perishable foods. Growth is affected by several environmental factors such as temperature, acidity level and salt concentration. In this study, we develop two models to describe bacterial growth for multiple populations under both equal and different environmental conditions. Firstly, a semi-parametric model based on the Gompertz equation is proposed. Assuming that the parameters of the Gompertz equation may vary in relation to the running conditions under which the experiment is performed, we use feed forward neural networks to model the influence of these environmental factors on the growth parameters. Secondly, we propose a more general model which does not assume any underlying parametric form for the growth function. Thus, we consider a neural network as a primary growth model which includes the influencing environmental factors as inputs to the network. One of the main disadvantages of neural networks models is that they are often very difficult to tune which complicates fitting procedures. Here, we show that a simple, Bayesian approach to fitting these models can be implemented via the software package WinBugs. Our approach is illustrated using real experimental Listeria Monocytogenes growth data

Jet Diffusion versus JetGPT -- Modern Networks for the LHC

We introduce two diffusion models and an autoregressive transformer for LHC physics simulations. Bayesian versions allow us to control the networks and capture training uncertainties. After illustrating their different density estimation methods for simple toy models, we discuss their advantages for Z plus jets event generation. While diffusion networks excel through their precision, the transformer scales best with the phase space dimensionality. Given the different training and evaluation speed, we expect LHC physics to benefit from dedicated use cases for normalizing flows, diffusion models, and autoregressive transformers.Comment: 37 pages, 17 figure

Planar cell polarity: the Dachsous/Fat system contributes differently to the embryonic and larval stages of Drosophila.

The epidermal patterns of all three larval instars (L1-L3) ofDrosophilaare made by one unchanging set of cells. The seven rows of cuticular denticles of all larval stages are consistently planar polarised, some pointing forwards, others backwards. In L1 all the predenticles originate at the back of the cells but, in L2 and L3, they form at the front or the back of the cell depending on the polarity of the forthcoming denticles. We find that, to polarise all rows, the Dachsous/Fat system is differentially utilised; in L1 it is active in the placement of the actin-based predenticles but is not crucial for the final orientation of the cuticular denticles, in L2 and L3 it is needed for placement and polarity. We find Four-jointed to be strongly expressed in the tendon cells and show how this might explain the orientation of all seven rows. Unexpectedly, we find that L3 that lack Dachsous differ from larvae lacking Fat and we present evidence that this is due to differently mislocalised Dachs. We make some progress in understanding how Dachs contributes to phenotypes of wildtype and mutant larvae and adults.This work was generously supported by the Wellcome Trust: a Project Grant [086986] and, later, two successive Investigator Awards, [096645 and 107060] awarded to P.A.L., as well as [100986] to D.S. P.S. thanks Fundaçã o para a Ciência e a Tecnologia and the Cambridge Philosophical Society for research studentships.This is the final version of the article. It first appeared from The Company of Biologists via https://doi.org/10.1242/bio.01715

Conspiring to decolonise language teaching and learning: reflections and reactions from a reading group

Within the spirit of conspiration, this article brings together contributions from participants of the PhD-led UCL Reading and React Group ‘Colonialism(s), Neoliberalism(s) and Language Teaching and Learning’, which ran in 2019/20. Weaving together various perspectives, the article centres on the dialogic nature of the decolonial enterprise and challenges the colonial concept of monologic authorial voice. Across the reflections on participants’ own engagements with questions of decolonising language teaching and learning, we pull together three threads: the inherent coloniality of the concepts that shape the very disciplines we seek to decolonise; the need to place decolonial efforts within broader contexts and to be sceptical of projects claiming to have completed the work of decolonising language teaching and learning; and the affordances and limitations offered to us by our positionalities, which the reflexivity of the conspirational encounter has allowed us to explore in some depth. The article closes with a reflection on the process of writing this article, and with the assertion that decolonising the curriculum is a multifaceted and open-ended process of dialogue and conspiration between practitioners and researchers alike

Collective autobiographical reflexivity on active and compassionate citizenship in the COVID-19 crisis

Since the outbreak of the coronavirus pandemic, socio-economic inequalities have become exacerbated and COVID-19 related hate crimes have increased. This paper explores how citizenship education might be reimagined in response to this context, with the vision of rebuilding a more equitable and compassionate society. By using a collective autobiographical writing approach, this study documented six different autobiographical reflexivities of citizenship education scholars who were from different parts of the world: China, South Korea, the Philippines, the United States, Nepal and the United Kingdom. It also observed the way the pandemic played out in the location where they were situated during the research as well as how it played out in their countries of origin, and further, how it affected the civic development in each context. The scholars\u27 range of autobiographical expressions resulted in insights for developing a type of citizenship education, namely, education for active and compassionate citizenship

Ice Particle Impacts on a Moving Wedge

This work presents the results of an experimental study of ice particle impacts on a moving wedge. The experiment was conducted in the Adverse Environment Rotor Test Stand (AERTS) facility located at Penn State University. The wedge was placed at the tip of a rotating blade. Ice particles shot from a pressure gun intercepted the moving wedge and impacted it at a location along its circular path. The upward velocity of the ice particles varied from 7 to 12 meters per second. Wedge velocities were varied from 0 to 120 meters per second. Wedge angles tested were 0 deg, 30 deg, 45 deg, and 60 deg. High speed imaging combined with backlighting captured the impact allowing observation of the effect of velocity and wedge angle on the impact and the post-impact fragment behavior. It was found that the pressure gun and the rotating wedge could be synchronized to consistently obtain ice particle impacts on the target wedge. It was observed that the number of fragments increase with the normal component of the impact velocity. Particle fragments ejected immediately after impact showed velocities higher than the impact velocity. The results followed the major qualitative features observed by other researchers for hailstone impacts, even though the reduced scale size of the particles used in the present experiment as compared to hailstones was 4:1