770 research outputs found
Momentum Cogging at the Fermilab Booster
The Fermilab booster has an intensity upgrade plan called the Proton
Improvement plan (PIP). The flux throughput goal is 2E17 protons/hour which is
almost double the current operation at 1.1E17 protons/hour. The beam loss in
the machine is going to be an issue. The booster accelerates beam from 400 MeV
to 8GeV and extracts to The Main Injector (MI). Cogging is the process that
synchronizes the extraction kicker gap to the MI by changing radial position of
the beam during the cycle. The gap creation occurs at about 700MeV which is
6msec into the cycle. The variation of the revolution frequency from cycle to
cycle is larger at lower energy and it is hard to control by changing the
radial position because of aperture limitations. Momentum cogging is able to
move the gap creation earlier by using dipole correctors and radial position
feedback, and controlling the revolution frequency and radial position at the
same time. The new cogging is going to save energy loss and aperture. The
progress of the momentum cogging system development is going to be discussed in
this paper.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012)
20-25 May 2012, New Orleans, Louisian
SCOPE - A Scientific Compound Object Publishing and Editing System
This paper presents the SCOPE (Scientific Compound Object Publishing and Editing) system which is designed to enable scientists to easily author, publish and edit scientific compound objects. Scientific compound objects enable scientists to encapsulate the various datasets and resources generated or utilized during a scientific experiment or discovery process, within a single compound object, for publishing and exchange. The adoption of ānamed graphsā to represent these compound objects enables provenance information to be captured via the typed relationships between the components. This approach is also endorsed by the OAI-ORE initiative and hence ensures that we generate OAI-ORE-compliant Scientific Compound Objects. The SCOPE system is an extension of the Provenance Explorer tool ā which enables access-controlled viewing of scientific provenance trails. Provenance Explorer provided dynamic rendering of RDF graphs of scientific discovery processes, showing the lineage from raw data to publication. Views of different granularity can be inferred automatically using SWRL (Semantic Web Rules Language) rules and an inferencing engine. SCOPE extends the Provenance Explorer tool and GUI by: 1) Adding an embedded web browser that can be used for incorporating objects discoverable via the Web; 2) Representing compound objects as Named Graphs, that can be saved in RDF, TriX, TriG or as an Atom syndication feed; 3) Enabling scientists to attach Creative Commons Licenses to the compound objects to specify how they may be re-used; 4) Enabling compound objects to be published as Fedora Object XML (FOXML) files within a Fedora digital library
Structural diversity in the AdoMet radical enzyme superfamily
AdoMet radical enzymes are involved in processes such as cofactor biosynthesis, anaerobic metabolism, and natural product biosynthesis. These enzymes utilize the reductive cleavage of S-adenosylmethionine (AdoMet) to afford l-methionine and a transient 5ā²-deoxyadenosyl radical, which subsequently generates a substrate radical species. By harnessing radical reactivity, the AdoMet radical enzyme superfamily is responsible for an incredible diversity of chemical transformations. Structural analysis reveals that family members adopt a full or partial Triose-phosphate Isomerase Mutase (TIM) barrel protein fold, containing core motifs responsible for binding a catalytic [4Feā4S] cluster and AdoMet. Here we evaluate over twenty structures of AdoMet radical enzymes and classify them into two categories: ātraditionalā and āThiC-likeā (named for the structure of 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase (ThiC)). In light of new structural data, we reexamine the ātraditionalā structural motifs responsible for binding the [4Feā4S] cluster and AdoMet, and compare and contrast these motifs with the ThiC case. We also review how structural data combine with biochemical, spectroscopic, and computational data to help us understand key features of this enzyme superfamily, such as the energetics, the triggering, and the molecular mechanisms of AdoMet reductive cleavage. This article is part of a Special Issue entitled: Radical SAM Enzymes and Radical Enzymology.Wellcome Trust (London, England) (091162/Z/10/Z)National Science Foundation (U.S.) (NSF Grant MCB-0543833)Howard Hughes Medical Institute (Investigator
Physician associate graduates in England: a cross-sectional survey of work careers.
Physician associates (PAs) are a new healthcare professional group in the UK. While PAs have been known as a stable but flexible workforce in the USA for over 50 years, little is known about their career paths in the UK's NHS. A cross sectional online survey (January 2020 - May 2020) of graduates from the longest running UK PA course investigated stability and factors influencing job retention or movement. One-hundred and sixty-two (71%) graduates provided a full response. Descriptive analysis was by early graduates (2006-2013), mid-graduates (2014-2017) and recent graduates (2018-2020). Early and mid-graduates held their first jobs for a mean of 3 years. For early graduates, the longest held job was 11 years, with a mode of 7 years. Enjoyment of the work, learning opportunities and working with supportive consultants were the most highly rated factors in PA job retention
The āins and outsā of faecal microbiota transplant for recurrent Clostridium difficile diarrhoea at Wits Donald Gordon Medical Centre, Johannesburg, South Africa
Background. Clostridium difficile-associated diarrhoea (CDAD) is a potentially life-threatening condition that is becoming increasingly common. A persistent burden of this infectious illness has been demonstrated over the past 4 years at Wits Donald Gordon Medical Centre (WDGMC), Johannesburg, South Africa, through implementation of active surveillance of hospital-acquired infections as part of the infection prevention and control programme. Oral treatment with metronidazole or vancomycin is recommended, but there is a major problem with symptomatic recurrence after treatment. Replacement of normal flora by the administration of donor stool through colonoscopy or nasogastric/duodenal routes is becoming increasingly popular.Objectives. To identify risk factors for the development of CDAD in patients referred for faecal microbiota transplant (FMT) and evaluate the safety of administration of donor stool as an outpatient procedure, including via the nasogastric route.Methods. A retrospective record review of patients with recurrent CDAD referred for FMT at WDGMC between 1 January 2012 and 31 December 2016 was conducted.Results. Twenty-seven patients were identified, all of whom fulfilled the criteria for recurrent CDAD. One-third were aged >65 years, and the majority were female. The most common risk factors were prior exposure to antibiotics or proton-pump inhibitors and underlying inflammatory bowel disease. Three procedures were carried out as inpatients and 24 in the outpatient gastroenterology unit. At 4-week follow-up, all patients reported clinical resolution of their diarrhoea after a single treatment and there were no recurrences. The FMT procedure was associated with no morbidity (with particular reference to the risk of aspiration when administered via the nasogastric route) or mortality.Conclusions. This case series confirms that FMT is a safe and effective therapy for recurrent CDAD. In most cases it can be administered via the nasogastric route in the outpatient department. We propose that the recently published South African Gastroenterology Society guidelines be reviewed with regard to recommendations for the route of administration of FMT and hospital admission. Meticulous prescription practice by clinicians practising in hospitals and outpatient settings, with particular attention to antimicrobials and chronic medication, is urgently required to prevent this debilitating and potentially life-threatening condition
Taxonomy and phylogeny of mud owls (Annelida: Sternaspidae), including a new synonymy and new records from the Southern Ocean, North East Atlantic Ocean and Pacific Ocean: challenges in morphological delimitation
Species delimitation in sternaspid polychaetes is currently based on the morphology of a limited suite of characters, namely characters of the ventro-caudal shieldāa unique feature of the family. Sternaspid species description has increased rapidly in recent years; however, the validity of the shield as a diagnostic character has not been assessed through molecular means. This study performs the largest molecular taxonomy of Sternaspidae to date, using the nuclear gene 18S, and the mitochondrial genes 16S and cytochrome oxidase subunit I (COI) to assess phylogenetic relationships within the family, to reassess the placement of Sternaspidae within the wider polychaete tree and to investigate the effectiveness of the shield as a diagnostic morphological character. This study includes many new records and reports Sternaspis affinis Stimpson, 1864 from USA Pacific coastline and genetic connectivity between specimens identified as Sternaspis cf. annenkovae Salazar-Vallejo & Buzhinskaja, 2013 from off southeastern Australia and specimens identified as Sternaspis cf. williamsae Salazar-Vallejo & Buzhinskaja, 2013 from the northwestern Pacific. In addition, we investigate material identified as Sternaspis cf. scutata (Ranzani, 1817) in the English Channel and compare with S. scutata through both molecular and morphological means. We further perform a detailed morphological and molecular investigation of new sternaspid material collected from the Southern Ocean and Antarctic Peninsula and regard Sternaspis monroi Salazar-Vallejo, 2014 syn. n. as a junior synonym of Sternaspis sendalli Salazar-Vallejo, 2014, two species recently described from the region, raising questions concerning the validity of current morphological delimitation.Ā© The Author(s) 2019
Open Access
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made
Health promotion for mild frailty based on behaviour change: Perceptions of older people and service providers.
Mild frailty is common among older people, but it is potentially reversible with health promotion interventions. Behaviour change may be a key to preventing progression of frailty; however, we know little about what interventions work best and how a behaviour change approach would be perceived by this group. The aim of this study was to explore how mildly frail older people perceive health promotion based on behaviour change and what factors affect engagement with this approach. We conducted semi-structured interviews with 16 older people with mild frailty who received a pilot home-based behaviour change health promotion service, including a dyad of older person/family carer, and two service providers delivering the service in two diverse areas of South England. Interviews were audio-recorded, transcribed and thematically analysed. The concept of goal setting was acceptable to most participants, though the process of goal setting needed time and consideration. Goals on maintaining independence, monitoring of progress and receiving feedback were reported to increase motivation. Physical/mental capability and knowledge/perception of own needs were main determinants of the type of goals chosen by participants as well as the approach used by the project workers. Older people with complex needs benefited from care coordination, with a combination of goal setting and elements of social, practical and emotional support in varying proportions. Mildly frail older people responded well to a behaviour change approach to promote health and well-being. Further consideration is needed of the most effective strategies based on complexity of needs, and how to overcome barriers among people with cognitive impairment
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