3,026 research outputs found
Anisotropic Pâwave attenuation measured from a multiâazimuth surface seismic reflection survey
A system of aligned vertical fractures produces azimuthal variations in stacking velocity and amplitude variation with offset, characteristics often reported in seismic reflection data for hydrocarbon exploration. Studies of associated attenuation anisotropy have been mostly theoretical, laboratory or vertical seismic profiling based. We used an 11 commonâmidpointâlong portion of each of four marine surfaceâseismic reflection profiles, intersecting each other at 45° within circa 100 m of a common location, to measure the azimuthal variation of effective attenuation, Qâ1eff and stacking velocity, in a shallow interval, about 100 m thick, in which consistently orientated vertical fracturing was expected due to an underlying salt diapirism. We found qualitative and quantitative consistency between the azimuthal variation in the attenuation and stacking velocity, and published amplitude variation with offset results. The 135° azimuth line showed the least apparent attenuation (1000 Qâ1eff= 16 ± 7) and the fastest stacking velocity, hence we infer it to be closest to the fracture trend: the orthogonal 45° line showed the most apparent attenuation (1000Qâ1eff= 52 ± 15) and slowest stacking velocity. The variation of Qâ1eff with azimuth Ï is well fitted by 1000Qâ1eff= 34 â 18cos[2(Ï+40°)] giving a fracture direction of 140 ± 23° (±1SD, derived from âbootstrappingâ fits to all 114 combinations of individual commonâmidpoint/azimuth measurements), compared to 134 ± 47° from published amplitude variation with offset data. The effects of shortâwindow spectral estimation and choices of spectral ratio bandwidth and offset ranges used in attenuation analysis, individually give uncertainties of up to ±13° in fracture direction. This magnitude of azimuthal variation can be produced by credible crack geometries (e.g., dry cracks, radius 6.5 m, aspect ratio 3 Ă 10â5, crack density 0.2) but we do not claim these to be the actual properties of the interval studied, because of the lack of well control (and its consequences for the choice of theoretical model and host rock physical properties) and the small number of azimuths available here
Knowledge and information needs of informal caregivers in palliative care : a qualitative systematic review
Objectives: To review current understanding of the knowledge and information needs
of informal caregivers in palliative settings. Data sources: Seven electronic databases
were searched for the period January 1994âNovember 2006: Medline, CINAHL, PsychINFO,
Embase, Ovid, Zetoc and Pubmed using a meta-search engine (MetalibÂź).
Key journals and reference lists of selected papers were hand searched. Review methods:
Included studies were peer-reviewed journal articles presenting original research.
Given a variety of approaches to palliative care research, a validated systematic review
methodology for assessing disparate evidence was used in order to assign scores to
different aspects of each study (introduction and aims, method and data, sampling,
data analysis, ethics and bias, findings/results, transferability/generalizability, implications
and usefulness). Analysis was assisted by abstraction of key details of study into
a table. Results: Thirty-four studies were included from eight different countries. The
evidence was strongest in relation to pain management, where inadequacies in caregiver
knowledge and the importance of education were emphasized. The significance
of effective communication and information sharing between patient, caregiver and
service provider was also emphasized. The evidence for other caregiver knowledge
and information needs, for example in relation to welfare and social support was
weaker. There was limited literature on non-cancer conditions and the care-giving
information needs of black and minority ethnic populations. Overall, the evidence
base was predominantly descriptive and dominated by small-scale studies, limiting
generalizability. Conclusions: As palliative care shifts into patientsâ homes, a more rigorously
researched evidence base devoted to understanding caregivers knowledge
and information needs is required. Research design needs to move beyond the current
focus on dyads to incorporate the complex, three-way interactions between patients,
service providers and caregivers in end-of-life care setting
Effects of temperature and glycerol and methanol-feeding profiles on the production of recombinant galactose oxidase in Pichia pastoris
Optimization of protein production from methanol-induced Pichia pastoris cultures is necessary to ensure high productivity rates and high yields of recombinant proteins. We investigated the effects of temperature and different linear or exponential methanol-feeding rates on the production of recombinant Fusarium graminearum galactose oxidase (EC 1.1.3.9) in a P. pastoris Mut+ strain, under regulation of the AOX1 promoter. We found that low exponential methanol feeding led to 1.5-fold higher volumetric productivity compared to high exponential feeding rates. The duration of glycerol feeding did not affect the subsequent product yield, but longer glycerol feeding led to higher initial biomass concentration, which would reduce the oxygen demand and generate less heat during induction. A linear and a low exponential feeding profile led to productivities in the same range, but the latter was characterized by intense fluctuations in the titers of galactose oxidase and total protein. An exponential feeding profile that has been adapted to the apparent biomass concentration results in more stable cultures, but the concentration of recombinant protein is in the same range as when constant methanol feeding is employed. (c) 2014 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 30:728-735, 201
Individual and medical characteristics of adults presenting to an urban emergency department in Ghana
Background: The aims of this study were to characterize the patients seeking acute care for injury and noninjury complaints in an urban Emergency Department in Ghana in order to 1) inform the curriculum of the newly developed Emergency Medicine resident training program 2) improve treatment processes, and 3) direct future community-wide injury prevention policiesStudy Design: A prospective cross-sectional survey of patients 18 years or older seeking care in an urban Accident and Emergency Center (AEC) was conducted between 7/13/2009 and 7/30/2009. Questionnaires were administered by trained research staff and each survey took 10-15 minutes to complete. Patients were asked questions regarding demographics, overall health and chief complaint.Results: 254 patients were included in the sample. Participantsâ chief complaints were classified as either medical or injury-related. Approximately one third (38%) of patients presented with injuries and 62% presented for medical complaints. The most common injury at presentation was due to a road traffic injury, followed by falls and assault/fight. The most common medical presentation was abdominal pain followed by difficulty breathing and fainting/ blackout. Only 13% arrived to AEC by ambulance and 51% were unable to ambulate at the time of presentation.Conclusion: Approximately one-third of non-fatal adult visits were for acute injury. Future research should focus on developing surveillance systems for both medical and trauma patients. Physicians that are specifically trained to manage both the acutely injured patient and the medical patient will serve this population well given the variety of patients that seek care at the AEC.Keywords: Emergency Medicine, Injury, Surveillance, Ghana, Characteristic
Speech rhythm: a metaphor?
Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep âprominence gradientâ, i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a âstress-timedâ language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow âsyntagmatic contrastâ between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and that it is this analogical process which allows speech to be matched to external rhythms
The dental implications of bisphosphonates and bone disease
The document attached has been archived with permission from the Australian Dental Association. An external link to the publisherâs copy is included.In 2002/2003 a number of patients presented to the South Australian Oral and Maxillofacial Surgery Unit with unusual non-healing extraction wounds of the jaws. All were middle-aged to elderly, medically compromised and on bisphosphonates for bone pathology. Review of the literature showed similar cases being reported in the North American oral and maxillofacial surgery literature. This paper reviews the role of bisphosphonates in the management of bone disease. There were 2.3 million prescriptions for bisphosphonates in Australia in 2003. This group of drugs is very useful in controlling bone pain and preventing pathologic fractures. However, in a small number of patients on bisphosphonates, intractable, painful, non-healing exposed bone occurs following dental extractions or denture irritation. Affected patients are usually, but not always, over 55 years, medically compromised and on the potent nitrogen containing bisphosphonates, pamidronate (Aredia/Pamisol), alendronate (Fosamax) and zolendronate (Zometa) for nonosteoporotic bone disease. Currently, there is no simple, effective treatment and the painful exposed bone may persist for years. The main complications are marked weight loss from difficulty in eating and severe jaw and neck infections. Possible preventive and therapeutic strategies are presented although at this time there is no evidence of their effectiveness. Dentists must ask about bisphosphonate usage for bone disease when recording medical histories and take appropriate actions to avoid the development of this debilitating condition in their patients
Oral cancer awareness amongst hospital nursing staff: a pilot study
<p>Abstract</p> <p>Background</p> <p>Oral cancer is as prevalent as cervical and testicular cancer in the United Kingdom. Nursing staff provide the oral health care for the patient population in hospital. Admission to hospital provides a 'window of opportunity' for oral cancer 'screening' via an oral health check during nursing clerking. This study aimed to investigate whether nursing staff are aware of risk factors for oral cancer, its clinical signs, and could therefore provide a 'screening' service for oral cancer.</p> <p>Method</p> <p>Through the use of a questionnaire we assessed 121 nursing staff on oral health check behaviour and attitudes; their knowledge of risk factors for oral cancer; their understanding of common clinical signs of oral cancer; and their undergraduate and postgraduate training in oral health and oral cancer.</p> <p>Results</p> <p>Over 80% thought oral health checks were important although only 49% performed this task regularly; approximately 70% identified smoking as a risk factor but less than 30% identified alcohol. Awareness of the clinical signs of oral cancer was low with 21% identifying white patches, 15% identifying ulceration and only 2% identifying red patches despite their malignant potential. Nurses within 3 years of qualification were significantly better at recognising risk factors for oral cancer than their colleagues, identifying a need for continuing postgraduate education on oral health and oral cancer. Sixty-one percent of nursing staff received oral healthcare as an undergraduate with 34 percent receiving postgraduate training.</p> <p>Conclusion</p> <p>An oral health check upon admission to hospital provides an opportunity for nurses to 'screen' for oral diseases including oral cancer and allows nurses a greater role in total patient care. Nurses' awareness of oral cancer risk factors and clinical signs was, however, poor. This study highlights a need for improved education of nurses on oral cancer to make the oral health check on admission viable for oral cancer screening.</p
Physics of Neutron Star Crusts
The physics of neutron star crusts is vast, involving many different research
fields, from nuclear and condensed matter physics to general relativity. This
review summarizes the progress, which has been achieved over the last few
years, in modeling neutron star crusts, both at the microscopic and macroscopic
levels. The confrontation of these theoretical models with observations is also
briefly discussed.Comment: 182 pages, published version available at
<http://www.livingreviews.org/lrr-2008-10
Beyond Volume: The Impact of Complex Healthcare Data on the Machine Learning Pipeline
From medical charts to national census, healthcare has traditionally operated
under a paper-based paradigm. However, the past decade has marked a long and
arduous transformation bringing healthcare into the digital age. Ranging from
electronic health records, to digitized imaging and laboratory reports, to
public health datasets, today, healthcare now generates an incredible amount of
digital information. Such a wealth of data presents an exciting opportunity for
integrated machine learning solutions to address problems across multiple
facets of healthcare practice and administration. Unfortunately, the ability to
derive accurate and informative insights requires more than the ability to
execute machine learning models. Rather, a deeper understanding of the data on
which the models are run is imperative for their success. While a significant
effort has been undertaken to develop models able to process the volume of data
obtained during the analysis of millions of digitalized patient records, it is
important to remember that volume represents only one aspect of the data. In
fact, drawing on data from an increasingly diverse set of sources, healthcare
data presents an incredibly complex set of attributes that must be accounted
for throughout the machine learning pipeline. This chapter focuses on
highlighting such challenges, and is broken down into three distinct
components, each representing a phase of the pipeline. We begin with attributes
of the data accounted for during preprocessing, then move to considerations
during model building, and end with challenges to the interpretation of model
output. For each component, we present a discussion around data as it relates
to the healthcare domain and offer insight into the challenges each may impose
on the efficiency of machine learning techniques.Comment: Healthcare Informatics, Machine Learning, Knowledge Discovery: 20
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Oral cancer awareness of undergraduate medical and dental students
<p>Abstract</p> <p>Background</p> <p>The incidence of oral cancer is increasing in the United Kingdom. Early detection of oral cancers makes them more amenable to treatment and allows the greatest chance of cure. Delay in presentation and/or referral has a significant effect on the associated morbidity and mortality. Lack of general medical practitioner and general dental practitioner oral cancer knowledge has been shown to contribute to delays in referral and treatment. The aim of this study was to investigate the oral cancer awareness of future general medical and general dental practitioners by assessing undergraduate medical and dental students' knowledge of prevention and early detection of oral cancer.</p> <p>Method</p> <p>Questionnaires were delivered to undergraduate medical and dental students at the University of Dundee, assessing oral examination habits, delivery of advice on oral cancer risk factors, knowledge of oral cancer risk factors and clinical appearance, preferred point of referral and requests for further information.</p> <p>Results</p> <p>Undergraduate medical students were less likely to examine patients' oral mucosa routinely and less likely to advise patients about risk factors for oral cancer. Medical students identified fewer oral cancer risk factors. In particular alcohol use was identified poorly. Medical students also identified fewer oral changes associated with oral cancer. Erythroplakia and erythroleukoplakia were identified poorly. Medical students felt less well informed regarding oral cancer. 86% and 92% of undergraduate medical and dental students respectively requested further information about oral cancer.</p> <p>Conclusion</p> <p>This study highlights the need for improved education of undergraduate medical and dental students regarding oral cancer.</p
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