64 research outputs found

    Advances on the modeling of the time evolution of dynamic aperture of hadron circular accelerators

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    Determining a model for the time scaling of the dynamic aperture of a circular accelerator is a topic of strong interest and intense research efforts in accelerator physics. The motivation arises in the possibility of finding a method to reliably extrapolate the results of numerical simulations well beyond what is currently possible in terms of CPU time. In earlier work, a proposal for a model based on Nekhoroshev theorem and Kolmogorov-Arnold-Moser theory was made. This model has been studied in detail and proved successful in describing the evolution of the dynamic aperture in numerical simulations, however a number of shortcomings had been identified and new models are proposed in this paper, which solve the observed issues. The new models have been benchmarked against numerical simulations for a simple system, the 4D H\ue9non map, as well as a realistic, non-linear representation of the beam dynamics in the LHC at 6.5 TeV providing in both cases excellent results

    Strain Accomodation in the Footwall of the Rubys Inn Thrust Fault, Hillsdale Canyon, Southern Utah

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    The Rubys Inn thrust fault in southern Utah has produced several styles of deformation in its footwall. This project describes four exceptionally well exposed examples of strain accommodation, including a mountain-scale, ductile footwall drag fold, cataclastic flexural slip between bedding surfaces of differing competencies, plastically deformed petrified wood within the zone of flexural slip, and cataclastic shear expressed as deformation bands. Such examples show how various lithologies can be deformed into a wide array of structures during a single deformation event. Furthermore, some of these structures result in changes in permeability, which are important for those interested in subsurface fluid flow

    Is null-point reconnection important for solar flux emergence?

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    The role of null-point reconnection in a 3D numerical MHD model of solar emerging flux is investigated. The model consists of a twisted magnetic flux tube rising through a stratified convection zone and atmosphere to interact and reconnect with a horizontal overlying magnetic field in the atmosphere. Null points appear as the reconnection begins and persist throughout the rest of the emergence, where they can be found mostly in the model photosphere and transition region, forming two loose clusters on either side of the emerging flux tube. Up to 26 nulls are present at any one time, and tracking in time shows that there is a total of 305 overall, despite the initial simplicity of the magnetic field configuration. We find evidence for the reality of the nulls in terms of their methods of creation and destruction, their balance of signs, their long lifetimes, and their geometrical stability. We then show that due to the low parallel electric fields associated with the nulls, null-point reconnection is not the main type of magnetic reconnection involved in the interaction of the newly emerged flux with the overlying field. However, the large number of nulls implies that the topological structure of the magnetic field must be very complex and the importance of reconnection along separators or separatrix surfaces for flux emergence cannot be ruled out.Comment: 26 pages, 12 figures. Added one referenc

    Field and Petrographic Analysis of the Indian Peak-Caliente Caldera Complex at Condor and English Canyons in Eastern Nevada

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    The Indian Peak-Caliente Caldera Complex, or IPCCC, is an ideal site to study how large-scale tectonic forces can influence mineralogy on a local scale. This research was completed and compiled by the Tectonics and Mineralogy classes at Southern Utah University during a joint class field study and subsequent laboratory analyses. During the field trip, the main focuses were to observe caldera collapse relationships and ignimbrite features and to collect samples at Condor Canyon and English Canyon, two sites near the border between Nevada and Utah within the IPCCC. After the field trip, the Tectonics class completed a detailed literature review of the overall tectonic evolution of the region while the Mineralogy students petrographically analyzed the collected samples. This report provides a summary of the results, including mineralogical descriptions; an interpretation of a piece-meal, or piston-like, collapse of the caldera complex; and a connection between the local geology and the regional tectonic setting

    Investigation of excited 0+ states in 160Er populated via the (p, t) two-neutron transfer reaction

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    Many efforts have been made in nuclear structure physics to interpret the nature of low-lying excited 0+ states in well-deformed rare-earth nuclei. However, one of the difficulties in resolving the nature of these states is that there is a paucity of data. In this work, excited 0+ states in the N = 92 nucleus 160Er were studied via the 162Er(p, t)160Er two-neutron transfer reaction, which is ideal for probing 0+ → 0+ transitions, at the Maier-Leibnitz-Laboratorium in Garching, Germany. Reaction products were momentum-analyzed with a Quadrupole-3-Dipole magnetic spectrograph. The 0+2 state was observed to be strongly populated with 18% of the ground state strength

    PROFIL WISATAWAN MUSEUM RADYA PUSTAKA SURAKARTA

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    Anggit Margaret, C9407031 2011. Profil Wisatawan Museum Radya Pustaka Surakarta. Program Studi Diploma III Usaha Perjalanan Wisata Fakultas Sastra Dan Seni Rupa Universitas Sebelas Maret Surakarta. Penelitian tugas akhir ini mengkaji tentang Profil Wisatawan di Museum Radya Pustaka Surakarta. Tujuan dari penelitian ini adalah untuk mengetahui dari daerah mana saja wisatawan yang berkunjung ke Museum Radya Pustaka, bagaimana ciri-ciri wisatawan yang berkunjung ke Museum Radya Pustaka serta harapan-harapan yang diinginkan wisatawan terhadap Museum Radya Pustaka. Penelitian dilakukan dengan metode kualitatif. Pengumpulan data dilakukan melalui wawancara dengan narasumber wisatawan yang berkujung di Museum Radya Pustaka Surakarta tempat penulis melakukan penelitian, serta studi pustaka dan studi dokumen guna menambah sumber data. Hasil penelitian menunjukkan bahwa (1) Sebagian besar wisatawan yang datang berasal dari Semarang sebesar 32%. (2) Mayoritas wisatawan yang berkunjung ke Museum Radya Pustaka berusia antara 17-25 tahun dan kebanyakan dari mereka adalah pelajar atau mahasiswa dengan prosentase 52%. (3) Sebagian besar wisatawan yang datang ke Museum Radya Pustaka adalah bertujuan untuk melakukan penelitian yaitu sebesar 34%. (4) Harapan wisatawan yang berkunjung terhadap kelangsungan Museum Radya Pustaka sebagian besar adalah agar ditingkatkan lagi pengelolaan dan keamanan museum, agar kejadian hilangnya benda-benda koleksi museum tidak terulang lagi dikemudian hari. Kesimpulan dari hasil penelitian ini bahwa wisatawan yang berkujung ke Museum Radya Pustaka Surakarta mayoritas berasal dari Semarang, mayoritas berusia 17-25 tahun dan kebanyakan dari mereka adalah berprofesi sebagai pelajar dan mahasiswa. Kebanyakan wisatawan yang datang bertujuan untuk melakukan penelitian, serta harapan wisatawan terhadap Museum Radya Pustaka adalah supaya lebih ditingkatkan lagi pengelolaan dan keamanan museum

    SARS-CoV-2-specific nasal IgA wanes 9 months after hospitalisation with COVID-19 and is not induced by subsequent vaccination

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    BACKGROUND: Most studies of immunity to SARS-CoV-2 focus on circulating antibody, giving limited insights into mucosal defences that prevent viral replication and onward transmission. We studied nasal and plasma antibody responses one year after hospitalisation for COVID-19, including a period when SARS-CoV-2 vaccination was introduced. METHODS: In this follow up study, plasma and nasosorption samples were prospectively collected from 446 adults hospitalised for COVID-19 between February 2020 and March 2021 via the ISARIC4C and PHOSP-COVID consortia. IgA and IgG responses to NP and S of ancestral SARS-CoV-2, Delta and Omicron (BA.1) variants were measured by electrochemiluminescence and compared with plasma neutralisation data. FINDINGS: Strong and consistent nasal anti-NP and anti-S IgA responses were demonstrated, which remained elevated for nine months (p < 0.0001). Nasal and plasma anti-S IgG remained elevated for at least 12 months (p < 0.0001) with plasma neutralising titres that were raised against all variants compared to controls (p < 0.0001). Of 323 with complete data, 307 were vaccinated between 6 and 12 months; coinciding with rises in nasal and plasma IgA and IgG anti-S titres for all SARS-CoV-2 variants, although the change in nasal IgA was minimal (1.46-fold change after 10 months, p = 0.011) and the median remained below the positive threshold determined by pre-pandemic controls. Samples 12 months after admission showed no association between nasal IgA and plasma IgG anti-S responses (R = 0.05, p = 0.18), indicating that nasal IgA responses are distinct from those in plasma and minimally boosted by vaccination. INTERPRETATION: The decline in nasal IgA responses 9 months after infection and minimal impact of subsequent vaccination may explain the lack of long-lasting nasal defence against reinfection and the limited effects of vaccination on transmission. These findings highlight the need to develop vaccines that enhance nasal immunity. FUNDING: This study has been supported by ISARIC4C and PHOSP-COVID consortia. ISARIC4C is supported by grants from the National Institute for Health and Care Research and the Medical Research Council. Liverpool Experimental Cancer Medicine Centre provided infrastructure support for this research. The PHOSP-COVD study is jointly funded by UK Research and Innovation and National Institute of Health and Care Research. The funders were not involved in the study design, interpretation of data or the writing of this manuscript

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    Fort McKay First Nation’s involvement in reclamation of Alberta’s oil sands development

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    Fort McKay is a Cree, Dene and MĂ©tis community situated in the epicentre of Alberta’s oil sands developments and the people of Fort McKay believe that this development is limiting their ability to carry out cultural activities within their Traditional Lands and that this has significant adverse effects on the maintenance of their cultural heritage. The Community has existed on their Traditional Lands for generations and places great value on the land and all that the land supports. Fort McKay has major concerns associated with both the “loss of land” and the condition of this land following mine closure and reclamation. The existing approved and proposed mine developments will ultimately occupy hundreds of thousand hectares of land and will not be fully reclaimed until the latter half of this century, with the likelihood that a further 10 to 20 years will be needed before the land can be certified as reclaimed. This means that the land occupied by these mines will be alienated from two to three generations of Fort McKay people. Fort McKay and the group of specialist consultants employed to work on behalf of the Community have worked closely with the Alberta government and oil sands developers to express the Community’s concerns and to push both industry and government to work towards meeting the immediate and long term objectives. Although Fort McKay cannot take credit for the recent improvements in mine closure regulation and performance, Fort McKay has certainly had a strong voice which has helped lead to a number of changes in approval conditions. Changes which we have seen over recent years include improved regulations for salvage and replacement of topsoil, recent changes to the management of fluid fine tailings and the requirement to initiate large scale trials of techniques to reclaim land to peat accumulating wetlands (fens and bogs). In the future, Fort McKay will continue to strive for faster reclamation that will restore the land to premining conditions, will seek the complete elimination of fluid fine tailings especially those which will be stored under a water cap in an end pit lake, will seek to ensure that acceptable water quality will be achieved within a reasonable timeframe following closure and will seek to ensure that the reclaimed landscape will support the full range of traditional uses including medicinal plants, berries, hunting, fishing and trapping.Non UBCUnreviewedOthe
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