49 research outputs found
Multiphysics simulation tools for designing motors for traction applications in hybrid and electric vehicles
Motor manufacturers are facing a difficult challenge in designing traction motors for the latest generation of hybrid and all-electric vehicles. The efficiency with which these motors can perform is critical, as it impacts on the vehicle range and battery life. Many of the issues involved in the motor design have a complex nature which requires multiple fields of physics such as electromagnetics (EM), mechanics and thermal analysis. All these physics are usually interdependent and have to be considered collectively in order to obtain optimal performance for a particular scenario. This paper presents a multiphysics simulation tool that was implemented to address this situation. The Opera FEA software suite [1] was developed to include a multiphysics analysis that can link several EM, thermal and stress analyses. Opera’s Machines Environment (parameterised template software for designing motors and generators) has been extended to allow easy setup of coupled multiphysics analyses such as EM to thermal and EM to stress. In order to further facilitate the coupling of different analyses, a link to the Python programming language was embedded in Opera FEA software. The embedded Python facility offers options to perform certain post-processing operations during the solving stage and hence allow data transfer between different stages of the multiphysics analysis. It also extends Opera’s capabilities to interact with other FEA software
Developing an Agent-Based Model for Haplodrassus rufipes (Araneae: Gnaphosidae), a Generalist Predator Species of Olive Tree Pests: Conceptual Model Outline
Olive growing has been facing major sustainability challenges due to intensification,
resulting in an increased use of pesticides and fertilizers and, consequently, in the depletion of
natural resources and loss of biodiversity and landscape values. This has created an urgent need to
develop models for managing complex agroecosystems that integrate factors affecting food quality,
sustainability and biodiversity, providing a supporting technique to understand the consequences
of agricultural management for ecosystem services. We are developing an advanced agent-based
simulation (ABS) applied to olive groves to model the effects of farming practices on the abundance
of olive pest predators. ABS is a modeling technique where agents represent animals (predator
arthropods, in our case) acting in their environment. Our model is based on an ABS system developed
by Aarhus University, the ALMaSS, which comprises highly detailed farm management and spatial
structures to construct dynamic landscapes where agents operate. In this work, we present the
conceptual model for one of the selected species, Haplodrassus rufipes (Araneae: Gnaphosidae.info:eu-repo/semantics/publishedVersio
Building a system of computational models to simulate natural pest control
A limitação natural de pragas é um serviço de ecossistema que deve ser promovido nos
sistemas agrícolas, já que pode ser usada como alternativa, ou complementarmente, à aplicação
de pesticidas. Consiste no consumo das pragas pelos seus inimigos naturais e pode ser
promovida através do estabelecimento de componentes paisagísticas que forneçam, a estes
inimigos das pragas, alimento alternativo e refúgio, para além da aplicação de práticas agrícolas
sustentáveis. No entanto, o delineamento de uma estratégia eficaz de limitação natural de
pragas está dependente da caracterização detalhada dos comportamentos dos animais que
fazem parte dessa cadeia trófica, nomeadamente, das pragas e dos seus predadores, o que pode
ser feito através de simulações computacionais. Neste contexto, e no âmbito do projeto
OLIVESIM, estamos a construir um sistema de modelos para simular a biologia e o
comportamento de duas espécies de artrópodes (1) a mosca-da-azeitona, Bactrocera oleae
(Rossi), praga chave da oliveira, e (2) a aranha de solo, Haplodrassus rufipes (Lucas), um dos
potenciais predadores da praga, e as suas interações com a paisagem selecionada para realizar
este estudo, localizada na região de Trás-os-Montes (Mirandela, Portugal) e caracterizada
fundamentalmente por olival tradicional. Para isso, está a ser utilizado o sistema ALMaSS
(Animal, Landscape and Man Simulation System), que recebe inputs diários de variáveis
climáticas e também de ações de gestão agrícola, e que é calibrado com dados sobre abundância
quantitativa e qualitativa de animais. Neste simpósio focamo-nos nestes dois modelos,
mostrando também o estado atual deste trabalho.Natural pest control is an ecosystem service that should be promoted in agricultural
systems, as it can be used as an alternative or complementary to pesticide application. It consists
in increasing the populations of natural pest enemies by establishing landscape components
that provide them with alternative food and refuge, and by applying sustainable agricultural
practices. However, the design of an effective strategy for natural pest control depends on the
detailed characterization of the behaviour of animals that are part of this trophic chain, namely
pests and their predators, which can be done through computational simulations. In this
context, and in the scope of project OLIVESIM, we are building a system of models to simulate
the biology and behaviours of two species (1) the olive fly, Bactrocera oleae (Rossi), key pest of
the olive tree, and (2) a ground spider, Haplodrassus rufipes (Lucas), one of the potential
predators of the pest, and their interactions with the landscape selected to carry out this study,
located in the region of Trás-os-Montes (Mirandela, Portugal) and characterized primarily by
traditional olive groves. For this, the ALMaSS (Animal, Landscape and Man Simulation System)
system is being used, which receives daily inputs of climatic variables and agricultural
management actions, and which is calibrated with data on quantitative and qualitative
abundance of animals. In this symposium, we focus on the models for these two animal species,
showing the current state of this work.info:eu-repo/semantics/publishedVersio
Detection of Hepatic Drug Metabolite-Specific T-Cell Responses Using a Human Hepatocyte, Immune Cell Coculture System
Drug-responsive T-cells are activated with the parent compound or metabolites, often via different pathways (pharmacological interaction and hapten). An obstacle to the investigation of drug hypersensitivity is the scarcity of reactive metabolites for functional studies and the absence of coculture systems to generate metabolites in situ. Thus, the aim of this study was to utilize dapsone metabolite-responsive T-cells from hypersensitive patients, alongside primary human hepatocytes to drive metabolite formation, and subsequent drug-specific T-cell responses. Nitroso dapsone-responsive T-cell clones were generated from hypersensitive patients and characterized in terms of cross-reactivity and pathways of T-cell activation. Primary human hepatocytes, antigen-presenting cells, and T-cell cocultures were established in various formats with the liver and immune cells separated to avoid cell contact. Cultures were exposed to dapsone, and metabolite formation and T-cell activation were measured by LC-MS and proliferation assessment, respectively. Nitroso dapsone-responsive CD4+ T-cell clones from hypersensitive patients were found to proliferate and secrete cytokines in a dose-dependent manner when exposed to the drug metabolite. Clones were activated with nitroso dapsone-pulsed antigen-presenting cells, while fixation of antigen-presenting cells or omission of antigen-presenting cells from the assay abrogated the nitroso dapsone-specific T-cell response. Importantly, clones displayed no cross-reactivity with the parent drug. Nitroso dapsone glutathione conjugates were detected in the supernatant of hepatocyte immune cell cocultures, indicating that hepatocyte-derived metabolites are formed and transferred to the immune cell compartment. Similarly, nitroso dapsone-responsive clones were stimulated to proliferate with dapsone, when hepatocytes were added to the coculture system. Collectively, our study demonstrates the use of hepatocyte immune cell coculture systems to detect in situ metabolite formation and metabolite-specific T-cell responses. Similar systems should be used in future diagnostic and predictive assays to detect metabolite-specific T-cell responses when synthetic metabolites are not available
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Optimizing the Protection of Cattle against Escherichia coli O157: H7 Colonization through Immunization with Different Combinations of H7 Flagellin, Tir, Intimin-531 or EspA
Enterohemorrhagic Escherichia coli (EHEC) are important human pathogens, causing hemorrhagic colitis and hemolytic uraemic syndrome in humans. E. coli O157:H7 is the most common serotype associated with EHEC infections worldwide, although other non-O157 serotypes cause life-threatening infections. Cattle are a main reservoir of EHEC and intervention strategies aimed at limiting EHEC excretion from cattle are predicted to lower the risk of human infection. We have previously shown that immunization of calves with recombinant versions of the type III secretion system (T3SS)-associated proteins EspA, intimin and Tir from EHEC O157:H7 significantly reduced shedding of EHEC O157 from experimentally-colonized calves, and that protection could be augmented by the addition of H7 flagellin to the vaccine formulation. The main aim of the present study was to optimize our current EHEC O157 subunit vaccine formulations by identifying the key combinations of these antigens required for protection. A secondary aim was to determine if vaccine-induced antibody responses exhibited cross-reactive potential with antigens from other EHEC serotypes. Immunization with EspA, intimin and Tir resulted in a reduction in mean EHEC O157 shedding following challenge, but not the mean proportion of calves colonized. Removal of Tir resulted in more prolonged shedding compared with all other groups, whereas replacement of Tir with H7 flagellin resulted in the highest levels of protection, both in terms of reducing both mean EHEC O157 shedding and the proportion of colonized calves. Immunization of calves with recombinant EHEC O157 EspA, intimin and Tir resulted in the generation of antibodies capable of cross-reacting with antigens from non-O157 EHEC serotypes, suggesting that immunization with these antigens may provide a degree of cross-protection against other EHEC serotypes. Further studies are now required to test the efficacy of these vaccines in the field, and to formally test the cross-protective potential of the vaccines against other non-O157 EHEC
Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial
Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome
The Animal Landscape and Man Simulation System (ALMaSS): a history, design, and philosophy
This article is the first article in the new topical RIO journal collection for ALMaSS. This editorial introduces ALMaSS, its history, component parts and philosophy, and forms a first access point for those interested in knowing more. It is written from my own personal perspective as the instigator and main developer for the system, effectively as the ‘father’ of ALMaSS
ALMaSS Landscape and Farming Simulation: software classes and methods
This article describes the landscape model for the Animal Landscape and Man Simulation System (ALMaSS). The article itself provides an overall description of the software classes and functions, with examples of use. In addition, there are links for code access, executable directory and code documentation for the model. These provide access to model details. The descriptions cover the landscape class, its internal data, and the class hierarchy primarily associated with the landscape simulation. They also cover the timing and scheduling of actions and provide an overview of the landscape class interface. The Farm and Farm Manager classes responsible for simulating farming activities are presented together with descriptions of crop classes for crop management and weather and calendar classes