312 research outputs found

    Towards an International Height Reference System: insights from the Colorado geoid experiment using AUSGeoid computation methods

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    We apply the AUSGeoid data processing and computation methodologies to data provided for the International Height Reference System (IHRS) Colorado experiment as part of the International Association of Geodesy Joint Working Groups 0.1.2 and 2.2.2. This experiment is undertaken to test a range of different geoid computation methods from international research groups with a view to standardising these methods to form a set of conventions that can be established as an IHRS. The IHRS can realise an International Height Reference Frame to be used to study physical changes on and within the Earth. The Colorado experiment study site is much more mountainous (maximum height 4401 m) than the mostly flat Australian continent (maximum height 2228 m), and the available data over Colorado are different from Australian data (e.g. much more extensive airborne gravity coverage). Hence, we have tested and applied several modifications to the AUSGeoid approach, which had been tailored to the Australian situation. This includes different methods for the computation of terrain corrections, the gridding of terrestrial gravity data, the treatment of long-wavelength errors in the gravity anomaly grid and the combination of terrestrial and airborne data. A new method that has not previously been tested is the application of a spherical harmonic high-pass filter to residual anomalies. The results indicate that the AUSGeoid methods can successfully be used to compute a high accuracy geoid in challenging mountainous conditions. Modifications to the AUSGeoid approach lead to root-mean-square differences between geoid models up to ~ 0.028 m and agreement with GNSS-levelling data to ~ 0.044 m, but the benefits of these modifications cannot be rigorously assessed due to the limitation of the GNSS-levelling accuracy over the computation area

    Visual Properties of Transgenic Rats Harboring the Channelrhodopsin-2 Gene Regulated by the Thy-1.2 Promoter

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    Channelrhodopsin-2 (ChR2), one of the archea-type rhodopsins from green algae, is a potentially useful optogenetic tool for restoring vision in patients with photoreceptor degeneration, such as retinitis pigmentosa. If the ChR2 gene is transferred to retinal ganglion cells (RGCs), which send visual information to the brain, the RGCs may be repurposed to act as photoreceptors. In this study, by using a transgenic rat expressing ChR2 specifically in the RGCs under the regulation of a Thy-1.2 promoter, we tested the possibility that direct photoactivation of RGCs could restore effective vision. Although the contrast sensitivities of the optomotor responses of transgenic rats were similar to those observed in the wild-type rats, they were enhanced for visual stimuli of low-spatial frequency after the degeneration of native photoreceptors. This result suggests that the visual signals derived from the ChR2-expressing RGCs were reinterpreted by the brain to form behavior-related vision

    Elevated intracranial pressure associated with hypermetabolism in isolated head trauma

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    Both metabolic rate and protein catabolism are known to increase following severe head trauma, but the etiology of this hypermetabolism is unknown. To further investigate the problem, we studied the metabolism of 17 patients with indirect calorimetry who had severe craniocerebral trauma only and who required ICP monitoring for management. Patients were studied daily and immediately after ICP spikes greater than 20 mmHg, prior to treatment with hyperventilation, osmotic diuretics, or barbiturates. Oxygen consumption (VO 2 ) was correlated with ICP. Two groups of patients were identified. Group I patients were treated with hyperventilation and osmotic diuretics while Group II patients additionally received cerebral metabolic depressants. Group I had a significant correlation coefficent between VO 2 and ICP. Significant hypercatabolism early in the post trauma period was demonstrated by increased urine urea nitrogen. Our observations suggest that in patients with craniocerebral trauma, elevated ICP is associated with increased oxygen consumption, protein catabolism and systemic hypermetabolism. Cerebral metabolic depressants blunted increases in VO 2 which were seen with elevated ICP.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41650/1/701_2005_Article_BF01402895.pd

    Polycomb Group Protein Bmi1 Is Required for Growth of RAF Driven Non-Small-Cell Lung Cancer

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    Background: We have previously described a RAF oncogene driven transgenic mouse model for non small cell lung cancer (NSCLC). Here we examine whether tumor initiation and growth requires the stem cell self-renewal factor Bmi1. Principal Findings: In order to evaluate Bmi1 function in NSCLC two founder lines that differ in incidence and latency of tumor formation were compared. Ablation of Bmi1 expression in both lines had a dramatically decreased tumor growth. As the line with shorter latency matched the life span of Bmi1 knock out mice, these mice were chosen for further study. The absence of Bmi1 did not decrease the number of tumor initiation in these mice as only the size and not the number of tumors decreased. Reduction in tumor growth resulted from an increase in cell death and decrease in cell cycle progression that corresponded with up-regulation of the p16 INK4a and p19 ARF. Significance: The data identifies Bmi1 as an important factor for expansion but not initiation of RAF driven NSCLC

    Are Good Intentions Good Enough?: Informed Consent Without Trained Interpreters

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    OBJECTIVE: To examine the informed consent process when trained language interpreters are unavailable. BACKGROUND: Ensuring sufficient patient understanding for informed consent is especially challenging for patients with Limited English Proficiency (LEP). While US law requires provision of competent translation for LEP patients, such services are commonly unavailable. DESIGN AND PARTICIPANTS: Qualitative data was collected in 8 prenatal genetics clinics in Texas, including interviews and observations with 16 clinicians, and 30 Latina patients. Using content analysis techniques, we examined whether the basic criteria for informed consent (voluntariness, discussion of alternatives, adequate information, and competence) were evident for each of these patients, contrasting LEP patients with patients not needing an interpreter. We present case examples of difficulties related to each of these criteria, and compare informed consent scores for consultations requiring interpretation and those which did not. RESULTS: We describe multiple communication problems related to the use of untrained interpreters, or reliance on clinicians’ own limited Spanish. These LEP patients appear to be consistently disadvantaged in each of the criteria we examined, and informed consent scores were notably lower for consultations which occurred across a language barrier. CONCLUSIONS: In the absence of adequate Spanish interpretation, it was uncertain whether these LEP patients were provided the quality and content of information needed to assure that they are genuinely informed. We offer some low-cost practice suggestions that might mitigate these problems, and improve the quality of language interpretation, which is essential to assuring informed choice in health care for LEP patients

    Perceived economic self‑sufficiency: a countryand generation‑comparative approach

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    We thank Michael Camasso and Radha Jagannathan as well as Asimina Christoforou, Gerbert Kraaykamp, Fay Makantasi, Tiziana Nazio, Kyriakos Pierrakakis, Jacqueline O’Reilly and Jan van Deth for their contribution to the CUPESSE project (Seventh Framework Programme; Grant Agreement No. 61325). CUPESSE received additional funding from the Mannheim Centre for European Social Research (MZES) and the Field of Focus 4 “Self-Regulation and Regulation: Individuals and Organisations” at Heidelberg University. We further acknowledge helpful comments on this article by two anonymous reviewers. Julian Rossello provided valuable research assistance.Electronic supplementary material The online version of this article (https ://doi.org/10.1057/ s4130 4-018-0186-3) contains supplementary material, which is available to authorized users.Existing datasets provided by statistical agencies (e.g. Eurostat) show that the economic and financial crisis that unfolded in 2008 significantly impacted the lives and livelihoods of young people across Europe. Taking these official statistics as a starting point, the collaborative research project “Cultural Pathways to Economic Self-Sufficiency and Entrepreneurship in Europe” (CUPESSE) generated new survey data on the economic and social situation of young Europeans (18–35 years). The CUPESSE dataset allows for country-comparative assessments of young people’s perceptions about their socio-economic situation. Furthermore, the dataset includes a variety of indicators examining the socio-economic situation of both young adults and their parents. In this data article, we introduce the CUPESSE dataset to political and social scientists in an attempt to spark a debate on the measurements, patterns and mechanisms of intergenerational transmission of economic self-sufficiency as well as its political implications.CUPESSE project (Seventh Framework Programme; Grant Agreement No. 61325

    Unification of New Zealand's local vertical datums: iterative gravimetric quasigeoid computations

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    New Zealand uses 13 separate local vertical datums (LVDs) based on normal-orthometric-corrected precise geodetic levelling from 12 different tide-gauges. We describe their unification using a regional gravimetric quasigeoid model and GPS-levelling data on each LVD. A novel application of iterative quasigeoid computation is used, where the LVD offsets computed from earlier models are used to apply additional gravity reductions from each LVD to that model. The solution converges after only three iterations yielding LVD offsets ranging from 0.24 m to 0.58 m with an average standard deviation of 0.08 m. The so-computed LVD offsets agree, within expected data errors, with geodetically levelled height differences at common benchmarks between adjacent LVDs. This shows that iterated quasigeoid models do have a role in vertical datum unification

    Short-term triple therapy with azithromycin for Helicobacter pylori eradication: Low cost, high compliance, but low efficacy

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    <p>Abstract</p> <p>Background</p> <p>The Brazilian consensus recommends a short-term treatment course with clarithromycin, amoxicillin and proton-pump inhibitor for the eradication of <it>Helicobacter pylori </it>(<it>H. pylori)</it>. This treatment course has good efficacy, but cannot be afforded by a large part of the population. Azithromycin, amoxicillin and omeprazole are subsidized, for several aims, by the Brazilian federal government. Therefore, a short-term treatment course that uses these drugs is a low-cost one, but its efficacy regarding the bacterium eradication is yet to be demonstrated. The study's purpose was to verify the efficacy of <it>H. pylori </it>eradication in infected patients who presented peptic ulcer disease, using the association of azithromycin, amoxicillin and omeprazole.</p> <p>Methods</p> <p>Sixty patients with peptic ulcer diagnosed by upper digestive endoscopy and <it>H. pylori </it>infection documented by rapid urease test, histological analysis and urea breath test were treated for six days with a combination of azithromycin 500 mg and omeprazole 20 mg, in a single daily dose, associated with amoxicillin 500 mg 3 times a day. The eradication control was carried out 12 weeks after the treatment by means of the same diagnostic tests. The eradication rates were calculated with 95% confidence interval.</p> <p>Results</p> <p>The eradication rate was 38% per intention to treat and 41% per protocol. Few adverse effects were observed and treatment compliance was high.</p> <p>Conclusion</p> <p>Despite its low cost and high compliance, the low eradication rate does not allow the recommendation of the triple therapy with azithromycin as an adequate treatment for <it>H. pylori </it>infection.</p
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