918 research outputs found
An S2 Fluorescence Model for Interpreting High-Resolution Cometary Spectra. I. Model Description and Initial Results
A new versatile model providing S2 fluorescence spectrum as a function of
time is developed with the aim of interpreting high resolution cometary
spectra. For the S2 molecule, it is important to take into account both
chemical and dynamic processes because S2 has a short lifetime and is confined
in the inner coma where these processes are most important. The combination of
the fluorescence model with a global coma model allows for the comparison with
observations of column densities taken through an aperture and for the analysis
of S2 fluorescence in different parts of the coma. Moreover, the model includes
the rotational structure of the molecule. Such a model is needed for
interpreting recent high spectral resolution observations of cometary S2. A
systematic study of the vibrational-rotational spectrum of S2 is undertaken,
including relevant effects, such as non-equilibrium state superposition and the
number density profile within the coma due to dynamics and chemistry, to
investigate the importance of the above effects on the scale length and
abundance of S2 in comets.Comment: 20 pages, 7 figure
Control System for the Holifield Radioactive Ion Beam Facility
A new accelerator control system is being impfemented as part of the development of the Holifield Radioactive Ion Beam Facility (HRIBF), a first generation radioactive ion beam (RIB) facility. The pre-existing accelerator control systems are based on 1970's technology and addition or alteration of controls is cumbersome and costly. A new, unified control system for the cyclotron and tandem accelerators. the RIB injector, ion sources, and accelerator beam lines is based on a commercial product from Vista Control Systems. Inc. Several other accelerator facilities. as well as numerous industrial sites, are now using this system. The control system is distributed over a number of computers which communicate over Ethernet and is easily extensible. Presently. implementation at the HRIBF is based on VAXNMS. VAX/ELN, VME, and Allen-Bradley PLCS programmable logic controller architectures. Expansion to include UMX platforms and CAMAC hardware support is planned. Operator interface is via X-terminals. The system has proven to be quite powerful, yet it has been easy to implement with a small staff. A Vista users group has resulted in shared software to implement specific controls. This paper details present system features and future implementations at the HRIBF
Rotational cooling of heteronuclear molecular ions with ^1-Sigma, ^2-Sigma, ^3-Sigma and ^2-Pi electronic ground states
The translational motion of molecular ions can be effectively cooled
sympathetically to translational temperatures below 100 mK in ion traps through
Coulomb interactions with laser-cooled atomic ions. The ro-vibrational degrees
of freedom, however, are expected to be largely unaffected during translational
cooling. We have previously proposed schemes for cooling of the internal
degrees of freedom of such translationally cold but internally hot
heteronuclear diatomic ions in the simplest case of ^1-Sigma electronic ground
state molecules. Here we present a significant simplification of these schemes
and make a generalization to the most frequently encountered electronic ground
states of heteronuclear molecular ions: ^1-Sigma, ^2-Sigma, ^3-Sigma and ^2-Pi.
The schemes are relying on one or two laser driven transitions with the
possible inclusion of a tailored incoherent far infrared radiation field.Comment: 16 pages, 13 figure
Microscope and microĂą camera assessment of Schneiderian membrane perforation via transcrestal sinus floor elevation: A randomized ex vivo study
ObjectiveWe sought to assess the effectiveness of using a microscope and nonĂą invasive camera for assessing sinus membrane perforations during transcrestal sinus floor elevation (TSFE).Materials and methodsFive fresh human cadaver heads corresponding to eight maxillary sinuses (six bilateral and two unilateral) underwent 4 TSFEs per sinus (a total of 32 single site elevations). Each elevation was randomly assigned to receive a three or sixĂÂ mm membrane elevation height (MEH). A microscope and microĂą camera were used to assess the sinus membrane perforation. Afterwards, radiological and clinical membrane perforation assessments were performed. The statistical analysis results are expressed using the means, standard deviations, range values of the residual ridge height (RRH), residual ridge width (RRW), sinus membrane thickness (SMT) and incidence of perforation (IoP). Generalized linear methods were used to test for the correlation of RRH and MEH to the microscope and microĂą camera perforation assessments and the correlation of microscope and microĂą camera assessments with the postĂą operative CBCT and crestal liquid evaluation.ResultsThe cumulative percentage of IoP was 40.62%, (23.07% with 3ĂÂ mm MEH, and 76.92% with 6ĂÂ mm MEH, pĂÂ <ĂÂ 0.05). The perforation assessed using either the microscope or microĂą camera coincided with the postĂą operative CBCT and crestal liquid assessment in 87.55% sites. No significant correlation was found between the microscope or microĂą camera assessments with RRH or MEH.ConclusionApplication of a microscope and microĂą camera during transcrestal sinus floor elevation may allow the detection of the integrity of the Schneiderian membrane with greater than 85% accuracy in this ex vivo model.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149727/1/clr13453.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149727/2/clr13453_am.pd
Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near the Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air and Ice Cores
In this study, we report measurements of CFC-12 (CCl2F2) in firn air and in air extracted from shallow ice cores from three Antarctic sites. The firn air data are consistent with the known atmospheric history of CFC-12. In contrast, some of the ice core samples collected near the firn-ice transition exhibit anomalously high CFC-12 levels. Together, the ice core and firn air data provide evidence for the presence of modern air entrapped in the shallow ice core samples that likely contained open pores at the time of collection. We propose that this is due to closure of the open pores after drilling, entrapping modern air and resulting in elevated CFC-12 mixing ratios. Our results reveal that open porosity can exist below the maximum depth at which firn air samples can be collected, particularly at sites with lower accumulation rates. CFC-12 measurements demonstrate that post-drilling closure of open pores can lead to a change in the composition of bubble air in shallow ice cores through purely physical processes. The results have implications for investigations involving trace gas composition of bubbles in shallow ice cores collected near the firn-ice transition
Overarching Priorities for Health and Care Research in the United Kingdom: A Coproduced Synthesis of James Lind Alliance âTop 10sâ
Introduction: James Lind Alliance (JLA) Priority Setting Partnerships (PSPs) produce âTop 10â lists of health and care research priorities through a structured, shared decisionâmaking process with patients or service users, carers and health or care professionals who identify questions that are most important to them. To date, over 150 PSPs in different areas of health and care have published research priorities. Some PSPs share similar priorities, which could be combined, promoted and addressed through collaborative research to increase value and reduce research waste. Aim: The aim of this study was to identify overarching themes common to JLA PSP priorities across different areas of health and care. Methods: Our analysis included âTop 10â research priorities produced by UKâbased JLA PSPs between 2016 and 2020. The priorities were coded deductively by the Health Research Classification System (HRCS) health category and research activity. We then carried out online workshops with patients, service users and carers to generate new codes not already captured by this framework. Within each code, multistakeholder inductive thematic analysis was used to identify overarching themes, defined as encompassing priorities from three or more PSPs covering two or more health categories. We used codesign methods to produce an interactive tool for end users to navigate the overarching themes. Results: Five hundred and fifteen research priorities from 51 PSPs were included in our analysis. The priorities together encompassed 20 of 21 HRCS health categories, the most common being âgeneric health relevanceâ (22%), âmental healthâ (18%) and âmusculoskeletalâ (14%). We identified 89 overarching themes and subthemes, which we organised into a hierarchy with seven topâlevel themes: quality of life, caregivers and families, causes and prevention, screening and diagnosis, treatment and management, services and systems and social influences and impacts. Conclusion: There are many overarching themes common to research priorities across multiple areas of health and care. To facilitate new research and research funding, we have developed an interactive tool to help researchers, funders and patients or service users to explore these priority topics. This is freely available to download online. Patient or Public Contribution: Patients or service users and carers were involved throughout the study, including deciding the aims, designing the study, analysing priorities to identify themes, interpreting and reporting the findings
Studies on the maize cold tolerance tests in the MartonvĂĄsĂĄr phytotron
The climatic conditions in Hungary and in the countries to which seed is exported
makes the study of maize cold tolerance and constant improvements in the cold tolerance
of MartonvĂĄsĂĄr hybrids especially important. An improvement in the early spring cold
tolerance of maize would allow it to be grown in more northern areas with a cooler
climate, while on traditional maize-growing areas the profitability of maize production
could be improved by earlier sowing, leading to a reduction in transportation and drying
costs and in diseases caused by Fusarium sp. The recognition of this fact led MartonvĂĄsĂĄr
researchers to start investigating this subject nearly four decades ago. The phytotron has
proved an excellent tool for studying and improving the cold tolerance of maize. The
review will give a brief summary of the results achieved in the field of maize cold
tolerance in the MartonvĂĄsĂĄr institute in recent decades
Engaging with issues of emotionality in mathematics teacher education for social justice
This article focuses on the relationship between social justice, emotionality and mathematics teaching in the context of the education of prospective teachers of mathematics. A relational approach to social justice calls for giving attention to enacting socially-just relationships in mathematics classrooms. Emotionality and social justice in teaching mathematics variously intersect, interrelate or interweave. An intervention, usng creative action methods, with a cohort of prospective teachers addressing these issues is described to illustrate the connection between emotionality and social justice in the context of mathematics teacher education. Creative action methods involve a variety of dramatic, interactive and experiential tools that can promote personal and group engagement and embodied reflection. The intervention aimed to engage the prospective teachers with some key issues for social justice in mathematics education through dialogue about the emotionality of teaching and learning mathematics. Some of the possibilities and limits of using such methods are considered
Assessment of somatosensory function and self-harm in adolescents
Importance: Self-harm is a risk factor for suicide in adolescents, with the prevalence highest in young people in group and residential care programs. Although no established risk factors for self-harm exist, adolescents who self-harm may have decreased pain sensitivity, but this has not been systematically investigated.
Objective To assess somatosensory function using quantitative sensory testing (QST) in children and adolescents living in care grouped by the number of episodes of self-harm in the past year and compare their somatosensory profiles with community control participants to investigate associations with the incidence or frequency of self-harm.
Design, Setting, and Participants: Recruitment for this cross-sectional study began January 2019 and ended March 2020. Exclusion criteria included intellectual disability (intelligence quotient <70), autism spectrum disorder, or recent serious injury. Children and adolescents aged 12 to 17 years with no underlying health conditions were recruited from local authority residential care settings in Glasgow, UK, and schools and youth groups in London and Glasgow, UK. The volunteer sample of 64 participants included adolescents ages 13 to 17 years (34 [53%] females; 50 [78%] living in residential care; mean [SD] age, 16.34 [1.01] years) with varying incidents of self-harm in the past year (no episodes, 31 [48%]; 1-4 episodes, 12 [19%]; and â„5 episodes, 2 [33%]).
Exposures: Participants were tested using a standardized QST protocol to establish baseline somatosensory function.
Main Outcomes and Measures: Associations between somatosensory sensitivity, incidence and frequency of self-harm, residential status, age, gender, and prescription medication were calculated. Secondary outcomes assessed whether self-harm was associated with specific types of tests (ie, painful or nonpainful).
Results: A total of 64 participants ages 13 to 17 years completed testing (mean [SD] age, 16.3 [1.0] years; 34 [53%.] females and 30 [47%] males; 50 [78%] living in group homes). Adolescents with 5 or more self-harm incidences showed significant pain hyposensitivity compared with community control participants after adjusting for age, gender, and prescription drug use (SH group with 5 or more episodes vs control: â1.03 [95% CI,ââ1.47 to â0.60]; Pâ<â.001). Hyposensitivity also extended to nonpainful stimuli, similarly adjusted (SH group with 5 or more episodes vs control: â1.73; 95% CI, â2.62 to â0.84; Pâ<â.001). Pressure pain threshold accounted for most of the observed variance (31.1% [95% CI, 10.5% to 44.7%]; Pâ<â.001).
Conclusions and Relevance: The findings of this study suggest that sensory hyposensitivity is a phenotype of Adolescents who self-harm and that pressure pain threshold has clinical potential as a quick, inexpensive, and easily interpreted test to identify adolescents at increased risk of repeated self-harm
Atmospheres from very low-mass stars to extrasolar planets
Within the next few years, several instruments aiming at imaging extrasolar
planets will see first light. In parallel, low mass planets are being searched
around red dwarfs which offer more favorable conditions, both for radial
velocity detection and transit studies, than solar-type stars. We review recent
advancements in modeling the stellar to substellar transition. The revised
solar oxygen abundances and cloud models allow to reproduce the photometric and
spectroscopic properties of this transition to a degree never achieved before,
but problems remain in the important M-L transition characteristic of the
effective temperature range of characterizable exoplanets.Comment: submitted to Memorie della Societa Astronomica Italian
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