16,281 research outputs found
Incorporation of Nitrogen into Organics Produced by Fischer-Tropsch Type Chemistry
Laboratory simulations have demonstrated that hydrothermal systems have the potential to produce a range of organic compounds through Fischer-Tropsch type (FTT) chemistry. The distribution of products depends on several factors, including the abundance and composition of feed-stock molecules, reaction temperature, and the physical and chemical characteristics of catalytic materials included in the reactions. The majority of studies per-formed to date have focused solely on inclusion of CO2 or CO and H2 as the carbon, oxygen and hydrogen sources, which limits the possible products to hydro-carbons, alcohols and carboxylic acids. A few studies have included nitrogen in the form of ammonia, which led to the production of amino acids and nitrogenous bases; and a separate suite of studies included sulfur as sulfide minerals or H2S, which yielded products such as thiols and amino acids. Although these demonstrations provide compelling evidence that FTT reactions can produce compounds of interest for the origins of life, such reactions have been conducted under a very limited range of conditions and the synthetic reaction mechanisms have generally not been well-characterized. As a consequence, it is difficult to extrapolate these results to geologic systems or to evaluate how variations in reactant compositions would affect the distribution of products over time. We have begun a series of laboratory experiments that will incorporate a range of precursor molecules in varying compositions to determine how these variables affect the relative amounts and speciation of life-essential elements in organic molecules produced under FTT conditions. In the present work, we focus on systems containing C, H, O and N
Understanding person acquisition using an interactive activation and competition network
Face perception is one of the most developed visual skills that humans display, and recent work has attempted to examine the mechanisms involved in face perception through noting how neural networks achieve the same performance. The purpose of the present paper is to extend this approach to look not just at human face recognition, but also at human face acquisition. Experiment 1 presents empirical data to describe the acquisition over time of appropriate representations for newly encountered faces. These results are compared with those of Simulation 1, in which a modified IAC network capable of modelling the acquisition process is generated. Experiment 2 and Simulation 2 explore the mechanisms of learning further, and it is demonstrated that the acquisition of a set of associated new facts is easier than the acquisition of individual facts in isolation of one another. This is explained in terms of the advantage gained from additional inputs and mutual reinforcement of developing links within an interactive neural network system. <br/
Assessing the barriers and enablers to the implementation of the diagnostic radiographer musculoskeletal X‑ray reporting service within the NHS in England: a systematic literature review
Introduction
The United Kingdom (UK) government’s healthcare policy in the early 1990s paved the way adoption
of the skills mix development and implementation of diagnostic radiographers’ X-ray reporting service. Current
clinical practice within the public UK healthcare system reflects the same pressures of increased demand in patient
imaging and limited capacity of the reporting workforce (radiographers and radiologists) as in the 1990s. This study
aimed to identify, define and assess the longitudinal macro, meso, and micro barriers and enablers to the implementation
of the diagnostic radiographer musculoskeletal X-ray reporting service in the National Healthcare System (NHS)
in England.
Methods
Multiple independent databases were searched, including PubMed, Ovid MEDLINE; Embase; CINAHL,
and Google Scholar, as well as journal databases (Scopus, Wiley), healthcare databases (NHS Evidence Database;
Cochrane Library) and grey literature databases (OpenGrey, GreyNet International, and the British Library EthOS
depository) and recorded in a PRISMA flow chart. A combination of keywords, Boolean logic, truncation, parentheses and wildcards with inclusion/exclusion criteria and a time frame of 1995–2022 was applied. The literature
was assessed against Joanna Briggs Institute’s critical appraisal checklists. With meta-aggregation to synthesize each paper, and coded using NVivo, with context grouped into macro, meso, and micro-level sources and categorised
into subgroups of enablers and barriers.
Results The wide and diverse range of data (n = 241 papers) identified barriers and enablers of implementation,
which were categorised into measures of macro, meso, and micro levels, and thematic categories of context, culture,
environment, and leadership.
Conclusion
The literature since 1995 has reframed the debates on implementation of the radiographer reporting
role and has been instrumental in shaping clinical practice. There has been clear influence upon both meso (professional
body) and macro-level (governmental/health service) policies and guidance, that have shaped change
at micro-level NHS Trust organisations. There is evidence of a shift in culturally intrenched legacy perspectives within and between different meso-level professional bodies around skills mix acceptance and role boundaries. This
has helped shape capacity building of the reporting workforce. All of which have contributed to conceptual understandings of the skills mix workforce within modern radiology services
A survey of the NHS reporting radiographer workforce in England
Introduction: At present there is no national register of the population size and scope of reporting radiographers in England. This makes operational workforce and succession planning for sustainable healthcare services in the National Health Service England (NHSE) difficult, affecting implementing NHSE policies and priorities such as 50% of X-rays reported by reporting radiographers and decreasing reporting Turnaround Times (TATs). This survey aimed to establish the workforce population employed as reporting radiographers in NHSE.
Methods: An online anonymous seven question survey was distributed on social media and at the UK Imaging and Oncology Congress. Participant criteria included NHSE radiology staff (diagnostic radiographer, reporting radiographer, radiology manager, imaging superintendent modality lead, consultant radiologist, etc.) or a student diagnostic radiographer working within an NHSE trust. The survey recorded the participant's NHSE region (North Western, North Eastern and Yorkshire, Midlands, East of England, London, South Eastern and South Western regions), Integrated Care Systems (ICS), NHSE Trust, hospital, the amount of reporting radiographers and trainees employed, the Agenda for Change (AfC) job banding and imaging modality reported (X-ray, CT, MRI, NM, PET, DEXA). The data analysis applied descriptive statistics for estimating patterns and trends in the distribution of data (English region, AfC banding and imaging modality).
Results: Responses were received from all seven of the NHSE regions (n=36/43 ICSs). The data demonstrated a larger workforce in the north of England than in the south, with employment at a range of AfC bandings from 5-8. The imaging modalities reported by radiographers in England demonstrated X-ray (n=34), the most reported imaging examination by region, and Nuclear Medicine (n=3) the least, with evidence of clinical reporting for CT (n=20), MRI (n=18), DEXA (n=16), Mammography (n=13) and fluoroscopy (n=12) being completed by radiographers in England.
Conclusion: The findings for England (n=704 reporters; n=142 trainees) provide an estimate based on the response rate of the current reporting radiographer workforce across the NHSE regions, and their contribution to the skills mix radiology reporting service delivery. It is hoped future surveys will provide ongoing workforce estimates for the diagnostic radiographer reporting workforce in NHSE to support workforce transformation and sustainability plans for the radiography profession and to meet government healthcare targets and priorities
The inexorable resistance of inertia determines the initial regime of drop coalescence
Drop coalescence is central to diverse processes involving dispersions of
drops in industrial, engineering and scientific realms. During coalescence, two
drops first touch and then merge as the liquid neck connecting them grows from
initially microscopic scales to a size comparable to the drop diameters. The
curvature of the interface is infinite at the point where the drops first make
contact, and the flows that ensue as the two drops coalesce are intimately
coupled to this singularity in the dynamics. Conventionally, this process has
been thought to have just two dynamical regimes: a viscous and an inertial
regime with a crossover region between them. We use experiments and simulations
to reveal that a third regime, one that describes the initial dynamics of
coalescence for all drop viscosities, has been missed. An argument based on
force balance allows the construction of a new coalescence phase diagram
Perceived barriers and facilitators to female condoms among UK based healthcare professionals
Objectives: The female condom (FC) is an effective strategy against sexually transmitted infections (STIs) in susceptible women and men who have sex with men. FCs are the only female-initiated dual protection method that protects against both STIs and unintended pregnancy. As healthcare professionals (HCPs) are a key element in the promotion of contraceptive use, it is important to examine attitudes toward FCs among this group.
Study participants: 15 male and female HCPs aged between 22-57 years recruited from sexual and reproductive health settings located in Brighton, London, and Glasgow. Sampling method: purposive sampling with targeted advertisements (newsletters and bulletins).
Study design: face-to-face and telephone interviews with sexual health HCPs. Main outcome measure: potential barriers and facilitators to FCs in the UK. Data were analysed thematically to identify common views and perspectives.
Results: FCs were thought to be unacceptable to most women due to stigma, design, negative visual appeal, insertion difficulties and lack of familiarity. The perceived unavailability and higher cost of FCs, in comparison to male condoms, are major barriers to their use.
Conclusions: HCPs are reluctant to promote FCs, often due to the perceived social stigma surrounding FCs. Further education and promotion are needed to increase acceptability and correct usage. Future research needs to explore strategies to increase the acceptability of FCs among women, men who have sex with men and HCPs
Design data collection with Skylab/EREP microwave instrument S-193
There are no author-identified significant results in this report
The molecular environment of massive star forming cores associated with Class II methanol maser emission
Methanol maser emission has proven to be an excellent signpost of regions
undergoing massive star formation (MSF). To investigate their role as an
evolutionary tracer, we have recently completed a large observing program with
the ATCA to derive the dynamical and physical properties of molecular/ionised
gas towards a sample of MSF regions traced by 6.7 GHz methanol maser emission.
We find that the molecular gas in many of these regions breaks up into multiple
sub-clumps which we separate into groups based on their association
with/without methanol maser and cm continuum emission. The temperature and
dynamic state of the molecular gas is markedly different between the groups.
Based on these differences, we attempt to assess the evolutionary state of the
cores in the groups and thus investigate the role of class II methanol masers
as a tracer of MSF.Comment: 5 pages, 1 figure, IAU Symposium 242 Conference Proceeding
Factors Influencing Consumer Likelihood of Purchasing a Flexible-Fuel or Hybrid Automobile
Developing fuels and vehicles that reduce our reliance on fossil fuels has become a priority due to the threat of global climate change and desire for reduced dependence on oil imports. Flexible-fuel vehicles that can run on ethanol/gasoline blends of up to 85% ethanol and hybrid electric vehicles present two such opportunities. While production of both flexible-fuel and hybrid vehicles is increasing, there is still a great deal of uncertainty about how consumers will respond to these products. To address this uncertainty, data was collected through an online survey of automobile owners that asked respondents how likely they were to choose either a flexible-fuel or hybrid vehicle as their next vehicle. A bivariate probit model was used to jointly analyze responses to these two questions. The results show that, while there was some overlap in the factors correlated with perceived likelihood of choosing one of these two types of automobiles, there were also clear differences. These results should benefit policymakers, marketers and academics seeking a better understanding of the respective markets for these vehicles.flexible-fuel vehicles, ethanol, E85, hybrid electric vehicles, Demand and Price Analysis, Environmental Economics and Policy, Resource /Energy Economics and Policy,
The scale-adusted latent class model: Application to museum visitation
© 2010 Cognizant Comm. Corp. Preferences of tourists and visitors are varied in a number of markets, making it difficult for managers to understand how underlying segments might respond to changes in service offerings. Market segments differ in preferences for specific features, as well as how consistently they make their choices. In this article, we illustrate recent developments in choice modeling that allows for simultaneously modeling feature preferences and consistency of choice. We use the Scale-Adjusted Latent Class Model (SALCM) to better understand choices in the context of a research project conducted in collaboration with six major Australian museums involving a sample of 3,685 museum visitors. We identify three preference classes of museum-goers that explain preferences for levels of 26 museum attributes: Life Force (two thirds of visitors), Educated Thinkers, and Wealthy At-Homes. Our results indicate sensitivity to general entry prices, including preference for free entry or entry "by donation." Tours are preferred if smaller, lengthier, and conducted by paid museum staff. Not unexpectedly, the findings suggest that museums should cater for children, with some classes responding positively to providing supervised child areas. Most visitors prefer museums that are dynamic, offer new experiences, and regularly update permanent displays. However, the three classes identified have different overall experience preferences; for example, Educated Thinkers see museums as an educational opportunity, but Wealthy At-Homes prefer entertaining experiences. Incentives for return visits and cross-museum promotional offers are valued by the Life Force class, but have little effect on Educated Thinkers. The SALCM approach may be attractive to other areas of tourism analysis, especially where offerings contain many attributes and potential market segments are difficult to define and understand
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