504 research outputs found
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Atmospheric observations of the water vapour continuum in the near-infrared windows between 2500 and 6600 cm-1
Water vapour continuum absorption is potentially important for both closure of the Earth's energy budget and remote sensing applications. Currently, there are significant uncertainties in its characteristics in the near-infrared atmospheric windows at 2.1 and 1.6 µm. There have been several attempts to measure the continuum in the laboratory; not only are there significant differences amongst these measurements, but there are also difficulties in extrapolating the laboratory data taken at room temperature and above to temperatures more widely relevant to the atmosphere. Validation is therefore required using field observations of the real atmosphere. There are currently no published observations in atmospheric conditions with enough water vapour to detect a continuum signal within these windows or where the self-continuum component is significant. We present observations of the near-infrared water vapour continuum from Camborne, UK, at sea level using a Sun-pointing, radiometrically calibrated Fourier transform spectrometer in the window regions between 2000 and 10 000 cm−1. Analysis of these data is challenging, particularly because of the need to remove aerosol extinction and the large uncertainties associated with such field measurements. Nevertheless, we present data that are consistent with recent laboratory datasets in the 4 and 2.1 µm windows (when extrapolated to atmospheric temperatures). These results indicate that the most recent revision (3.2) of the MT_CKD foreign continuum, versions of which are widely used in atmospheric radiation models, requires strengthening by a factor of ∼5 in the centre of the 2.1 µm window. In the higher-wavenumber window at 1.6 µm, our estimated self- and foreign-continua are significantly stronger than MT_CKD. The possible contribution of the self- and foreign-continua to our derived total continuum optical depth is estimated by using laboratory or MT_CKD values of one, to estimate the other. The obtained self-continuum shows some consistency with temperature-extrapolated laboratory data in the centres of the 4 and 2.1 µm windows. The 1.6 µm region is more sensitive to atmospheric aerosol and continuum retrievals and therefore more uncertain than the more robust results at 2.1 and 4 µm. We highlight the difficulties in observing the atmospheric continuum and make the case for additional measurements in both the laboratory and field and discuss the requirements for any future field campaign
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Can measurements of the near-infrared solar spectral irradiance be reconciled? A new ground-based assessment between 4000-10000 cm-1
The near-infrared solar spectral irradiance (SSI) is of vital importance for understanding the Earth’s radiation budget, and in Earth observation applications. Differences between previously published solar spectra (including the commonly-used ATLAS3 spectrum) reach up to 10% at the low-wavenumber end of the 4000-10000 cm-1 (2.5 – 1 μm) spectral region. The implications for the atmospheric sciences are significant, since this spectral region contains 25% of the incoming total solar irradiance. This work details an updated analysis of the CAVIAR SSI, featuring additional analysis techniques and an updated uncertainty budget using a Monte Carlo method. We report good consistency with ATLAS3 in the 7000-10000 cm-1 region where there is confidence in these results due to agreement with other spectra, but ~7% lower in the 4000-7000 cm-1 region, in general agreement with several other analyses
Towards diagnostic conversational profiles of patients presenting with dementia or functional memory disorders to memory clinics
Objective: This study explores whether the profile of patients' interactional behaviour in memory clinic conversations with a doctor can contribute to the clinical differentiation between functional memory disorders (FMD) and memory problems related to neurodegenerative diseases.
Methods: Conversation Analysis of video recordings of neurologists' interactions with patients attending a specialist memory clinic. "Gold standard" diagnoses were made independently of CA findings by a multi-disciplinary team based on clinical assessment, neuropsychological testing and brain imaging.
Results: Two discrete conversational profiles for patients with memory complaints emerged, including (i) who attends the clinic (i.e., whether or not patients are accompanied), and (ii) patients' responses to neurologists' questions about memory problems, such as difficulties with compound questions and providing specific and elaborated examples and frequent "I don't know" responses.
Conclusion: Specific communicative difficulties are characteristic of the interaction patterns of patients with a neurodegenerative pathology. Those difficulties are manifest in memory clinic interactions with neurologists, thereby helping to differentiate patients with dementia from those with FMD. Practical implications: Our findings demonstrate that conversational profiles based on patients' contributions to memory clinic encounters have diagnostic potential to assist the screening and referral process from primary care, and the diagnostic service in secondary care
Lessons from Laparoscopic Liver Surgery: A Nine-Year Case Series
Objective. This series describes a developing experience in laparoscopic liver surgery presenting results from 40 procedures including right hemihepatectomy, left lateral lobectomy, and microwave ablation therapy. Methods. Forty patients undergoing laparoscopic liver surgery between September 1997 and November 2006 were included. The data set includes: operative procedure and duration, intraoperative blood loss, conversion to open operation rates, length of hospital stay, complications, mortality, histology of lesions/resection margins, and disease recurrence. Results. Mean age of patient: 59 years, 17/40 male, 23/40 female, 23/40 of lesions were benign, and 17/40 malignant. Operations included: laparoscopic anatomical resections n = 15, nonanatomical resections n = 11, microwave ablations n = 8 and deroofing of cysts n = 7. Median anaesthetic time: 120 minutes (range 40–240), mean blood loss 78 mL and 1/40 conversions to open. Median resection margins were 10 mm (range 1–14) and median length of stay 3 days (range 1–10). Operative and 30-day mortality were zero with no local disease recurrence. Conclusion. Laparoscopic liver surgery appears safe and effective and is associated with reduced hospital stay. Larger studies are required to confirm it is oncologically sound
From Rags to Riches: Assessing poverty and vulnerability in urban Nepal
Urbanisation brings with it rapid socio-economic change with volatile livelihoods and unstable ownership of assets. Yet, current measures of wealth are based predominantly on static livelihoods found in rural areas. We sought to assess the extent to which seven common measures of wealth appropriately capture vulnerability to poverty in urban areas. We then sought to develop a measure that captures the characteristics of one urban area in Nepal. We collected and analysed data from 1,180 households collected during a survey conducted between November 2017 and January 2018 and designed to be representative of the Kathmandu valley. A separate survey of a sub set of households was conducted using participatory qualitative methods in slum and non-slum neighbourhoods. A series of currently used indices of deprivation were calculated from questionnaire data. We used bivariate statistical methods to examine the association between each index and identify characteristics of poor and non-poor. Qualitative data was used to identify characteristics of poverty from the perspective of urban poor communities which were used to construct an Urban Poverty Index that combined asset and consumption focused context specific measures of poverty that could be proxied by easily measured indicators as assessed through multivariate modelling. We found a strong but not perfect association between each measure of poverty. There was disagreement when comparing the consumption and deprivation index on the classification of 19% of the sample. Choice of short-term monetary and longer-term capital approaches accounted for much of the difference. Those who reported migrating due to economic necessity were most likely to be categorised as poor. A combined index was developed to capture these dimension of poverty and understand urban vulnerability. A second version of the index was constructed that can be computed using a smaller range of variables to identify those in poverty. Current measures may hide important aspects of urban poverty. Those who migrate out of economic necessity are particularly vulnerable. A composite index of socioeconomic status helps to capture the complex nature of economic vulnerability
Self-similar Solutions to a Kinetic Model for Grain Growth
We prove the existence of self-similar solutions to the Fradkov model for
two-dimensional grain growth, which consists of an infinite number of
nonlocally coupled transport equations for the number densities of grains with
given area and number of neighbours (topological class). For the proof we
introduce a finite maximal topological class and study an appropriate
upwind-discretization of the time dependent problem in self-similar variables.
We first show that the resulting finite dimensional differential system has
nontrivial steady states. Afterwards we let the discretization parameter tend
to zero and prove that the steady states converge to a compactly supported
self-similar solution for a Fradkov model with finitely many equations. In a
third step we let the maximal topology class tend to infinity and obtain
self-similar solutions to the original system that decay exponentially.
Finally, we use the upwind discretization to compute self-similar solutions
numerically.Comment: 25 pages, several figure
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Sex-Biased Expression of Sex-Differentiating Genes FOXL2 and FGF9 in American Alligators, Alligator mississippiensis
Across amniotes, sex-determining mechanisms exhibit great variation yet the genes that govern sexual differentiation are largely conserved. Studies of evolution of sex-determining and sex- differentiating genes require an exhaustive characterization of functions of those genes such as FOXL2 and FGF9. FOXL2 is associated with ovarian development and FGF9 is known to play a role in testicular organogenesis in mammals and other amniotes. As a step toward characterization of the evolutionary history of sexual development, we measured expression of FOXL2 and FGF9 across three developmental stages and eight juvenile tissue types in male and female American alligators, Alligator mississippiensis. We report surprisingly high expression of FOXL2 before the stage of embryonic development when sex is determined in response to temperature and sustained and variable expression of FGF9 in juvenile male but not female tissue types. Novel characterization of gene expression in reptiles with temperature-dependent sex determination such as American alligators may inform the evolution of sex-determining and sex-differentiating gene networks as they suggest alternative functions from which the genes may have been exapted. Future functional profiling of sex-differentiating genes should similarly follow other genes and other species to enable a broad comparison across sex-determining mechanisms.Organismic and Evolutionary Biolog
"Of Mice and Measures": A Project to Improve How We Advance Duchenne Muscular Dystrophy Therapies to the Clinic
A new line of dystrophic mdx mice on the DBA/2J (D2) background has emerged as a candidate to study the efficacy of therapeutic approaches for Duchenne muscular dystrophy (DMD). These mice harbor genetic polymorphisms that appear to increase the severity of the dystropathology, with disease modifiers that also occur in DMD patients, making them attractive for efficacy studies and drug development. This workshop aimed at collecting and consolidating available data on the pathological features and the natural history of these new D2/mdx mice, for comparison with classic mdx mice and controls, and to identify gaps in information and their potential value. The overall aim is to establish guidance on how to best use the D2/mdx mouse model in preclinical studies
Assessing the impact of care farms on quality of life and offending: a pilot study among probation service users in England
OBJECTIVES: To assess the feasibility of conducting a cost-effectiveness study of using care farms (CFs) to improve quality of life and reduce reoffending among offenders undertaking community orders (COs). To pilot questionnaires to assess quality of life, connection to nature, lifestyle behaviours, health and social-care use. To assess recruitment and retention at 6 months and feasibility of data linkage to Police National Computer (PNC) reconvictions data and data held by probation services. DESIGN: Pilot study using questionnaires to assess quality of life, individually linked to police and probation data. SETTING: The pilot study was conducted in three probation service regions in England. Each site included a CF and at least one comparator CO project. CFs are working farms used with a range of clients, including offenders, for therapeutic purposes. The three CFs included one aquaponics and horticulture social enterprise, a religious charity focusing on horticulture and a family-run cattle farm. Comparator projects included sorting secondhand clothes and activities to address alcohol misuse and anger management. PARTICIPANTS: We recruited 134 adults (over 18) serving COs in England, 29% female. RESULTS: 52% of participants completed follow-up questionnaires. Privatisation of UK probation trusts in 2014 negatively impacted on recruitment and retention. Linkage to PNC data was a more successful means of follow-up, with 90% consenting to access their probation and PNC data. Collection of health and social-care costs and quality-adjusted life year derivation were feasible. Propensity score adjustment provided a viable comparison method despite differences between comparators. We found worse health and higher reoffending risk among CF participants due to allocation of challenging offenders to CFs, making risk of reoffending a confounder. CONCLUSIONS: Recruitment would be feasible in a more stable probation environment. Follow-up was challenging; however, assessing reconvictions from PNC data is feasible and a potential primary outcome for future studies
Community engagement interventions for communicable disease control in low- and lower- middle-income countries : evidence from a review of systematic reviews
BACKGROUND: Community engagement (CE) interventions include a range of approaches to involve communities in the improvement of their health and wellbeing. Working with communities defined by location or some other shared interest, these interventions may be important in assisting equity and reach of communicable disease control (CDC) in low and lower-middle income countries (LLMIC). We conducted an umbrella review to identify approaches to CE in communicable disease control, effectiveness of these approaches, mechanisms and factors influencing success. METHODS: We included systematic reviews that: i) focussed on CE interventions; ii) involved adult community members; iii) included outcomes relevant to communicable diseases in LLMIC; iv) were written in English. Quantitative results were extracted and synthesised narratively. A qualitative synthesis process enabled identification of mechanisms of effect and influencing factors. We followed guidance from the Joanna Briggs Institute, assessed quality with the DARE tool and reported according to standard systematic review methodology. RESULTS: Thirteen systematic reviews of medium-to-high quality were identified between June and July 2017. Reviews covered the following outcomes: HIV and STIs (6); malaria (2); TB (1); child and maternal health (3) and mixed (1). Approaches included: CE through peer education and community health workers, community empowerment interventions and more general community participation or mobilisation. Techniques included sensitisation with the community and involvement in the identification of resources, intervention development and delivery. Evidence of effectiveness of CE on health outcomes was mixed and quality of primary studies variable. We found: i) significantly reduced neonatal mortality following women's participatory learning and action groups; ii) significant reductions in HIV and other STIs with empowerment and mobilisation interventions with marginalised groups; iii) significant reductions in malaria incidence or prevalence in a small number of primary studies; iv) significant reductions in infant diarrhoea following community health worker interventions. Mechanisms of impact commonly occurred through social and behavioural processes, particularly: changing social norms, increasing social cohesion and social capacity. Factors influencing effectiveness of CE interventions included extent of population coverage, shared leadership and community control over outcomes. CONCLUSION: Community engagement interventions may be effective in supporting CDC in LLMIC. Careful design of CE interventions appropriate to context, disease and community is vital
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