66 research outputs found

    Axial Magnetic Field Effect on Taylor-Couette Flow

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    This study is interested in the effect of an axial magnetic field imposed on incompressible flow of electrically conductive fluid between two horizontal coaxial cylinders. The imposed magnetic field is assumed uniform and constant. The effect of heat generation due to viscous dissipation is also taken into account. The inner and outer cylinders are maintained at different uniform temperatures. The movement of the fluid is due to rotation of the cylinder with a constant speed. An exact solution of the equations governing the flow was obtained in the form of Bessel functions. A finite difference implicit scheme was used in the numerical solution. The velocity and temperature distributions were obtained with and without the magnetic field. The results show that for different values of the Hartmann number, the velocity between the two cylinders decreases as the Hartmann number increases. Also, it is found that by increasing the Hartmann number, the average Nusselt number decreases. On the other hand, the Hartmann number does not affect the temperature

    WEIBEL INSTABILITY IN A BI-MAXWELLIAN LASER FUSION PLASMA

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    We are interested in this paper to analyse the Weibel instability driven by the plasma temperature anisotropy in the corona of a high intense laser created plasma. The unperturbed electronic distribution function, of the anisotropic corona is supposed to be a bi

    Embalmed heads of the Celtic Iron Age in the south of France

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    Ancient texts described that one of the most impressive ritual practices of the Celts during the Iron Age was to remove the heads of enemies killed in battle and to embalm them for display in front of the victors dwellings. An archaeological settlement excavation site in Le Cailar, in southern France, has revealed a considerable number of examples of this practice. It was documented by Classical authors and later by the archaeological recording of iconographic representations and skeletal remains of human heads. Weapons were also exhibited alongside the severed heads. Here we report the results of chemical investigations for the characterization of the biomarkers of embalming that are likely to be present in eleven fragments of these human cranial remains. These results may lead to answers to some of the archaeometric questions related to the subject of embalming in 3rd century BC Transalpine Gaul, thus advancing the knowledge of these ritual practices, documented by Greek Classical authors as part of the wider research into the proto-historic societies of the Mediterranean coastal region

    Assessing the impact of university students’ involvement in the first year of Nurture-U: a national student wellbeing research project

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    This is the final version. Available on open access from BMC via the DOI in this recordAvailability of data and materials: Anonymised data is available from the corresponding author on reasonable request.Background Students experience lower levels of wellbeing than the general, age-matched population. A whole-university approach to mental health is encouraged, which must work for individuals from all backgrounds and experiences. Student input is vital in researching and designing these solutions. Nurture-U is a national, large-scale research project exploring better ways to support student wellbeing, with a Student Advisory Group (SAG) that feeds into project decision making. With the first year of the project now completed, we now critically review the processes and effectiveness of the SAG and how well the project is engaging and working with students. Methods Assessment of the SAG’s impact on the project, the student advisors, and the researchers was undertaken through a content analysis of team meetings and collection of advisor and researcher feedback using the Patient Engagement Quality Guidance Tool. Results 142 students worked on different tasks in the first year of the Nurture-U project. The SAG was involved in the project branding and marketing, and in the development and co-design of interventions and tools. They reported a positive experience, with involvement boosting confidence. They felt valued but reported not always knowing whether their input was implemented in final decisions. They also recommended different methods of providing feedback. Researchers found student input beneficial to communicate the viewpoint of a different generation and increase the relevance of the study, but also suggested improvements for communication between the research team and the student group. Conclusions This critical reflection of the SAG’s public advisor role in this large-scale research project was important in highlighting what worked well and areas to improve. As the project unfolds, we aim to adapt our methods of student input, increase the transparency of decision-making processes, and in turn increase student-led decision making within the project.Medical Research Council (MRC

    14 Examples of How LLMs Can Transform Materials Science and Chemistry: A Reflection on a Large Language Model Hackathon

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    Chemistry and materials science are complex. Recently, there have been great successes in addressing this complexity using data-driven or computational techniques. Yet, the necessity of input structured in very specific forms and the fact that there is an ever-growing number of tools creates usability and accessibility challenges. Coupled with the reality that much data in these disciplines is unstructured, the effectiveness of these tools is limited. Motivated by recent works that indicated that large language models (LLMs) might help address some of these issues, we organized a hackathon event on the applications of LLMs in chemistry, materials science, and beyond. This article chronicles the projects built as part of this hackathon. Participants employed LLMs for various applications, including predicting properties of molecules and materials, designing novel interfaces for tools, extracting knowledge from unstructured data, and developing new educational applications. The diverse topics and the fact that working prototypes could be generated in less than two days highlight that LLMs will profoundly impact the future of our fields. The rich collection of ideas and projects also indicates that the applications of LLMs are not limited to materials science and chemistry but offer potential benefits to a wide range of scientific disciplines

    Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

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    Background: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15–20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases. Methods: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded. Results: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5–528.7, P = 1.1 × 10−4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3–8.2], P = 2.1 × 10−4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1–2635.4], P = 3.4 × 10−3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3–8.4], P = 7.7 × 10−8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10−5). Conclusions: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old

    The Story of the Moving Islanders: Exploring Tuvaluan Migrants' Place Attachment and Sense of Belonging between the Homeland and the Host Land.

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    My PhD thesis focuses on the attachment of Tuvaluan immigrants to their homeland and the host land. It is motivated to understand the effect of migration on their place attachment and belonging, navigation across the island and ocean, and thoughts on climate change that threatens Tuvalu's continuity. I use place attachment theory because it is a useful theoretical lens to explore Tuvaluans' interrelationship with the homeland and the host land post-migration. I am particularly interested in understanding whether Tuvaluans' attachment to the homeland decays or persists post-migration and how they process their sense of belonging to New Zealand. The research uses mixed methods: a survey, Talanoa conversations (a Pacific storytelling approach) and participant observation from a three-month field trip to New Zealand in September – November 2019. My main findings indicate that the Tuvaluan participants keep a strong attachment to Tuvalu and develop an attachment to New Zealand. Attachment to both places does not exist in tension. Yet, certain variations reveal different degrees of personal, sociocultural and environmental struggles among some participants. The participants' attachment to Tuvalu is emotional, sociocultural, and nostalgic. Meanwhile, their attachment to New Zealand is mostly based on a functional place dependence, making Tuvalu the "home" and New Zealand the "house". Nevertheless, some participants' decaying attachment to Tuvalu becomes apparent due to socioeconomic and environmental pressures. Similarly, although New Zealand becomes the house or the home-away-from-home that provides safety and prospects, the participants experience socioeconomic and geographic challenges. These pressures and challenges in both loci lead to the emergence of solastalgia, a sense of alienation and stress. The research stresses that Tuvaluans are not mere future environmental refugees. Instead, they move and carry intricate transnational ties with the homeland they wish to preserve, embrace the alternative routes, and express their place attachment through social, cultural, and relational patterns

    Modélisation asymptotique d’une coque peu-profonde de Marguerre-von Kármán généralisée dans le cas dynamique

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    International audienceIn a recent work Gratie has generalized the classical Marguerre-von Kármán equations studied by Ciarlet and Paumier in [2], where only a portion of the lateral face is subjected to boundary conditions of von Kármán’s type and the remaining portion being free. She shows that the leading term of the asymptotic expansion is characterized by a two-dimensional boundary value problem. In this paper, we extend formally this study to dynamic case.Dans un travail récent Gratie [7] a généralisé les équations de Marguerre-von Kármán classiques étudiées par Ciarlet et Paumier dans [2], où une partie seulement de la face latérale est soumise à des conditions aux limites de type von Kármán et la partie restante étant libre. Elle montre que le terme dominant du développement asymptotique est caractérisé par un problème aux limites bi-dimensionnel. Dans ce travail, on étend formellement cette étude au cas dynamiqu

    Modélisation asymptotique d’une coque peu-profonde de Marguerre-von Kármán généralisée dans le cas dynamique

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    In a recent work Gratie has generalized the classical Marguerre-von Kármán equations studied by Ciarlet and Paumier in [2], where only a portion of the lateral face is subjected to boundary conditions of von Kármán’s type and the remaining portion being free. She shows that the leading term of the asymptotic expansion is characterized by a two-dimensional boundary value problem. In this paper, we extend formally this study to dynamic case.Dans un travail récent Gratie [7] a généralisé les équations de Marguerre-von Kármán classiques étudiées par Ciarlet et Paumier dans [2], où une partie seulement de la face latérale est soumise à des conditions aux limites de type von Kármán et la partie restante étant libre. Elle montre que le terme dominant du développement asymptotique est caractérisé par un problème aux limites bi-dimensionnel. Dans ce travail, on étend formellement cette étude au cas dynamiqu

    Numerical investigation of the stability in triangular lobed Taylor-Couette flow

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