680 research outputs found
Sun glint estimation in marine satellite images: a comparison of results from calculation and radiative transfer modeling
The intensity and location of Sun glint in two Medium Resolution Imaging Spectrometer (MERIS) images was modeled using a radiative transfer model that includes elevation features as well as the slope of the sea surface. The results are compared to estimates made using glint flagging and correction approaches used within standard atmospheric correction processing code. The model estimate gives a glint pattern with a similar width but lower peak level than any current method, or than that estimated by a radiative transfer model with surfaces that include slope but not height. The MERIS third reprocessing recently adopted a new slope statistics model for Sun glint correction; the results show that this model is an outlier with respect to both the elevation model and other slope statistics models and we recommend that its adoption should be reviewed
Fluorescent analysis of photosynthetic microbes and Polycyclic Aromatic Hydrocarbons linked to optical remote sensing
Fluorescence analysis, being a non-invasive technique, has become one of the most powerful and widely used techniques for microbiologists and chemists to study various types of sample from photosynthetic microbes to hydrocarbons. The work reported here focuses on experimental results of fluorescent features of photosynthetic microbial species (cyanobacteria) and also five different crude oil samples. The cyanobacteria samples were collected from the Baltic Sea at the end of July 2011 and were associated with cyanobacterial bloom events, and the crude oil samples were from various oil spill events. The aim of the study was to find fluorescent biosignatures of cyanobacteria (initially a species specific to the Baltic Sea) and the fingerprints of crude oil; oil spills can be difficult to differentiate from biogenic films when using Synthetic Aperture Radar (SAR) or sunglint contaminated optical imagery. All samples were measured using a Perkin Elmer LS55 Luminescence spectrometer over a broad range of excitation and emission wavelength from ultraviolet (UV) to near infrared (NIR). The results are presented in Excitation Emission Matrices (EEMs) that exhibit the fluorescent features of each sample. In the EEM of the seawater sample containing cyanobacteria, there is an intense emission peak from tryptophan with fluorescent excitation and emission peaks at 285 and 345 nm respectively. In addition, fluorescent signatures of phycocyanin and chlorophyll-a are present with excitation and emission centre wavelengths at 555 nm, 645 nm and 390 nm, 685 nm, respectively. Additionally, the fluorescence signatures of Polycyclic Aromatic Hydrocarbons (PAHs) are present in the EEMs of crude oil samples with excitation and emission peaks at 285 nm and 425 nm. This study underpins further research on how to distinguish cyanobacteria species by their fluorescence signatures and the potential role that PAHs play in detection of cyanobacteria fluorescence features
Automating biomedical data science through tree-based pipeline optimization
Over the past decade, data science and machine learning has grown from a
mysterious art form to a staple tool across a variety of fields in academia,
business, and government. In this paper, we introduce the concept of tree-based
pipeline optimization for automating one of the most tedious parts of machine
learning---pipeline design. We implement a Tree-based Pipeline Optimization
Tool (TPOT) and demonstrate its effectiveness on a series of simulated and
real-world genetic data sets. In particular, we show that TPOT can build
machine learning pipelines that achieve competitive classification accuracy and
discover novel pipeline operators---such as synthetic feature
constructors---that significantly improve classification accuracy on these data
sets. We also highlight the current challenges to pipeline optimization, such
as the tendency to produce pipelines that overfit the data, and suggest future
research paths to overcome these challenges. As such, this work represents an
early step toward fully automating machine learning pipeline design.Comment: 16 pages, 5 figures, to appear in EvoBIO 2016 proceeding
Kinetics, quantitative analysis and radioimmunolocalization using indium-111-HMFG1 monoclonal antibody in patients with breast cancer.
HMFG1 tumour associated monoclonal antibody IgG1 and F(ab')2 fragments were radiolabelled with indium-111 and used to study patients with breast cancer. In vitro and in vivo stability of the radiolabelled antibodies was shown to be satisfactory. Thirty patients with primary breast cancer underwent tumour resection and quantitative evaluation of the radioactivity in the tumour and normal tissues following administration of specific and non-specific antibodies. The mean tumour uptake of HMFG1 F(ab')2 fragments at 24 h was significantly higher (P less than 0.05) than the intact IgG but at 48 h there was no difference. The mean tumour uptake with the specific antibody was higher than the non-specific antibody of the same subclass (P less than 0.05). Lymph node metastases showed higher antibody uptake than the corresponding primary tumours (P less than 0.05). Fifteen patients with primary or metastatic breast cancer were investigated by external body scintigraphy using HMFG1 F(ab')2 fragments. Successful localisation was observed in approximately 50% of the primary and metastatic lesions with no false positive results. All the patients had observable concentration of 111In in the liver (20% of the injected dose), the kidneys and the spleen. Following i.v. administration, F(ab')2 fragments cleared from the blood more rapidly than the intact IgG. We conclude that HMFG1 F(ab')2 fragments can localise specifically and faster than intact IgG in breast cancer but the sensitivity of the radioimmunoscintigraphy is relatively low. This method needs further improvement before becoming clinically useful for detecting and staging breast cancer
Midwife-led debriefing after operative birth: four to six year follow-up of a randomised trial [ISRCTN24648614]
BACKGROUND: There is little evidence that single-session debriefing is effective in reducing adverse mental health outcomes after trauma. Few trials have included long-term follow-up, but two also suggest possible negative effects of debriefing. We aimed to assess longer-term maternal health outcomes in a trial of midwife-led debriefing following an operative birth, given that findings at six months could not rule out a possible adverse effect of debriefing. METHODS: Four to six years after participating in a midwife-led trial of debriefing following an operative birth, 1039/1041 women were mailed a questionnaire containing the Edinburgh Postnatal Depression Scale (EPDS) and the SF-36 health status measure. RESULTS: Responses were obtained from 534 women (51.4%). Responders from the two trial groups remained comparable 4–6 years postpartum. No significant differences on maternal health outcomes were found between the trial groups. CONCLUSION: In the longer term, maternal health status was neither positively nor adversely affected by the experience of debriefing, despite a hint of adverse effects at six months postpartum. Short debriefing interventions have not proven effective in improving mental health outcomes for women following childbirth
March - forthcoming). Building bridges for collaborative digital reference between libraries and museums through an examination of reference in special collections. Journal of Academic Librarianship. Building Bridges for Collaborative Digital Reference be
ABSTRACT While a growing number of the digital reference services in libraries have become part of collaborative reference networks, other entities that serve similar information-seeking needs such as special collections and museums have not joined these networks, even though they are answering an increasing number of questions from off-site patrons via the Internet. This article examines the differences between questions asked electronically of traditional reference services and those asked of special collections services; it further explores how a better understanding of digital reference in special collections will facilitate the development of the tools and models needed to create a bridge between digital human intermediation at general academic libraries, special collections, and museums
Inhomogeneous magnetization in dipolar ferromagnetic liquids
At high densities fluids of strongly dipolar spherical particles exhibit
spontaneous long-ranged orientational order. Typically, due to demagnetization
effects induced by the long range of the dipolar interactions, the
magnetization structure is spatially inhomogeneous and depends on the shape of
the sample. We determine this structure for a cubic sample by the free
minimization of an appropriate microscopic density functional using simulated
annealing. We find a vortex structure resembling four domains separated by four
domain walls whose thickness increases proportional to the system size L. There
are indications that for large L the whole configuration scales with the system
size. Near the axis of the mainly planar vortex structure the direction of the
magnetization escapes into the third dimension or, at higher temperatures, the
absolute value of the magnetization is strongly reduced. Thus the orientational
order is characterized by two point defects at the top and the bottom of the
sample, respectively. The equilibrium structure in an external field and the
transition to a homogeneous magnetization for strong fields are analyzed, too.Comment: 17 postscript figures included, submitted to Phys. Rev.
The Perceptions of Teenagers, Young Adults and Professionals in the participation of Bone Cancer Clinical Trials
The reasons why teenagers and young adults with cancer do, or do not, participate in clinical trials is not wholly understood. We explored the perceptions and experiences of young people with bone cancer, and health professionals involved in their care, with regard to participation in two clinical trials. We conducted semi-structured interviews using narrative inquiry with twenty-one young people aged 15 to 24 years and eighteen health professionals. New understandings emerged about perceptions of, and factors that influence participation in, clinical trials. These include perceptions about the importance and design of the clinical trial, communicating with young people in an age-specific manner, using language young people are comfortable with, support from family and peers and specialists in teenage and young adult cancer .care. We conclude that addressing these factors may increase acceptability of clinical trials and the trial design for teenagers and young adults with cancer and ultimately improve their participation. Qualitative research has an important role in making explicit the perceptions and practices that ensure trials are patient-centred, appropriate and communicated effectively to teenagers and young adults. Translating knowledge gained into routine practice, will go some way in ensuring that the disparities affecting this population are more fully understood.The reasons why teenagers and young adults with cancer do, or do not, participate in clinical trials is not wholly understood. We explored the perceptions and experiences of young people with bone cancer, and health professionals involved in their care, with regard to participation in two clinical trials. We conducted semi-structured interviews using narrative inquiry with twenty-one young people aged 15 to 24 years and eighteen health professionals. New understandings emerged about perceptions of, and factors that influence participation in, clinical trials. These include perceptions about the importance and design of the clinical trial, communicating with young people in an age-specific manner, using language young people are comfortable with, support from family and peers and specialists in teenage and young adult cancer .care. We conclude that addressing these factors may increase acceptability of clinical trials and the trial design for teenagers and young adults with cancer and ultimately improve their participation. Qualitative research has an important role in making explicit the perceptions and practices that ensure trials are patient-centred, appropriate and communicated effectively to teenagers and young adults. Translating knowledge gained into routine practice, will go some way in ensuring that the disparities affecting this population are more fully understood
Clinical psychologists’ use of reflection and reflective practice within clinical work
Previous research regarding reflective practice has considered the training and development of reflective skills; little attention has been paid to how these are used by clinicians in practice. This study aims to understand how clinical psychologists experience reflection and reflective practice in their day-to-day clinical role. Six practicing clinical psychologists in Singapore were interviewed regarding their experiences. The interviews were analysed using Interpretative Phenomenological Analysis. Participants experienced reflection and reflective practice in many ways. Reflection helped the participants understand themselves better and how they personally impacted their work. Reflection helped in understanding and engaging with clients; it was particularly important for the development of the therapeutic relationship, and when cases felt ‘stuck’. Finally, reflection helped participants understand their professional role as clinicians, and maintain professional and ethical standards. Whilst participants valued reflection and could describe the mechanisms they used to reflect, they struggled to define reflective practice and their own process of reflection. In conclusion, participants were able to describe how using reflection and reflective practice within their clinical work benefited them and their clients. Further investigation into this area is required, particularly focusing on the challenging issue of developing a clearer definition of reflective practice
Influenza and SARS-coronavirus activating proteases TMPRSS2 and HAT are expressed at multiple sites in human respiratory and gastrointestinal tracts.
The type II transmembrane serine proteases TMPRSS2 and HAT activate influenza viruses and the SARS-coronavirus (TMPRSS2) in cell culture and may play an important role in viral spread and pathogenesis in the infected host. However, it is at present largely unclear to what extent these proteases are expressed in viral target cells in human tissues. Here, we show that both HAT and TMPRSS2 are coexpressed with 2,6-linked sialic acids, the major receptor determinant of human influenza viruses, throughout the human respiratory tract. Similarly, coexpression of ACE2, the SARS-coronavirus receptor, and TMPRSS2 was frequently found in the upper and lower aerodigestive tract, with the exception of the vocal folds, epiglottis and trachea. Finally, activation of influenza virus was conserved between human, avian and porcine TMPRSS2, suggesting that this protease might activate influenza virus in reservoir-, intermediate- and human hosts. In sum, our results show that TMPRSS2 and HAT are expressed by important influenza and SARS-coronavirus target cells and could thus support viral spread in the human host
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