44 research outputs found
Joint Elastic Side-Scattering Lidar and Raman Lidar Measurements of Aerosol Optical Properties in South East Colorado
We describe an experiment, located in south-east Colorado, USA, that measured
aerosol optical depth profiles using two Lidar techniques. Two independent
detectors measured scattered light from a vertical UV laser beam. One detector,
located at the laser site, measured light via the inelastic Raman
backscattering process. This is a common method used in atmospheric science for
measuring aerosol optical depth profiles. The other detector, located
approximately 40km distant, viewed the laser beam from the side. This detector
featured a 3.5m2 mirror and measured elastically scattered light in a bistatic
Lidar configuration following the method used at the Pierre Auger cosmic ray
observatory. The goal of this experiment was to assess and improve methods to
measure atmospheric clarity, specifically aerosol optical depth profiles, for
cosmic ray UV fluorescence detectors that use the atmosphere as a giant
calorimeter. The experiment collected data from September 2010 to July 2011
under varying conditions of aerosol loading. We describe the instruments and
techniques and compare the aerosol optical depth profiles measured by the Raman
and bistatic Lidar detectors.Comment: 34 pages, 16 figure
The Proportion of Endometrial Tumours Associated with Lynch Syndrome (PETALS): a prospective cross-sectional study
This is the final version. Available on open access from the Public Library of Science via the DOI in this recordBackground: Lynch syndrome (LS) predisposes to endometrial (EC), colorectal and other cancers through inherited pathogenic variants affecting mismatch-repair (MMR) genes. Diagnosing LS in women with EC can reduce subsequent cancer mortality through colonoscopic surveillance and aspirin chemoprevention; it also enables cascade testing of relatives. A growing consensus supports LS screening in EC, however, the expected proportion of test-positives and optimal testing strategy is uncertain. Previous studies from insurance-based healthcare systems were limited by narrow selection criteria, failure to apply reference standard tests consistently and poor conversion to definitive testing. The aim of this study was to establish the prevalence of LS and the diagnostic accuracy of LS testing strategies in an unselected EC population.
Methods and Findings: This was a prospective cross-sectional study carried out at a large UK gynaecological cancer centre between October/2015 and January/2017. Women diagnosed with EC or atypical hyperplasia (AH) were offered LS testing. Tumours underwent MMR immunohistochemistry (IHC), microsatellite instability (MSI) and targeted MLH1-methylation testing. Women <50 years, with strong family histories and/or indicative tumour molecular features underwent MMR germline sequencing. Somatic MMR sequencing was performed when indicative molecular features were unexplained by LS or MLH1-hypermethylation. The main outcome measures were the prevalence of LS in an unselected EC population and the diagnostic accuracy of clinical and tumour testing strategies for risk stratifying women with EC for MMR germline sequencing.
In total, 500 women participated in the study; only 2 (<1%) declined. Germline sequencing was indicated and conducted for 136 and 135 women, respectively. 16/500 women (3.2%, 95% CI 1.8% to 5.1%) had LS and 11 more (2.2%) had MMR variants of uncertain significance. Restricting testing to age <50 years, indicative family history (revised Bethesda guidelines or Amsterdam-II criteria) or endometrioid histology alone would have missed 9 (56%), 11 (69%) or 12 (75%), and 5 (31%) of the 16 cases of LS, respectively. In total 132/500 tumours were MMR-deficient by IHC, of which 83/132 (63%) had MLH1-hypermethylation and 16/49 (33%) of the remaining patients had LS (16/132 with MMR-deficiency, 12%). MMR-IHC with targeted MLH1-methylation testing was more discriminatory for LS than MSI/methylation testing, with 100% versus 56.3% (16/16 versus 9/16) sensitivity (p=0.016) and equal 97.5% (468/484) specificity. 64% MSI-H and 73% MMR-deficient tumours unexplained by LS or MLH1-hypermethylation had somatic MMR-mutations. The main limitation of the study was failure to conduct MMR germline sequencing for the whole study population, which means that the sensitivity and specificity of tumour triage strategies for LS detection may be over-estimated, although the risk of LS in women with no clinical or tumour predictors is expected to be extremely low.
Conclusions: In this study, we observed that age, family history and histology are imprecise clinical correlates of LS-EC. IHC outperformed MSI for tumour triage, and reliably identified both germline and somatic MMR mutations. The 3.2% proportion of LS-EC is similar to colorectal cancer, supporting unselected screening of EC for LS.
High Frequency Communications Features Highs and Lows
As cyber threats continue to grow, so does the reality that digital satellite communications can be degraded and denied either through digital or electromagnetic means. If these capabilities are compromised, however, high frequency radio provides a means to continue communicating even beyond the line of sight by leveraging the ionosphere to refract radio signals back to earth
Lactobacillus gasseri Causing Bilateral Empyema
Lactobacilli are common commensal bacteria found in the gastrointestinal and genitourinary tract. Although they are usually thought to be nonpathogenic, there have been several cases that demonstrate severe infections caused by these microorganisms. This is a case of a 49-year-old male with previously undiagnosed type two diabetes mellitus who presented with a 3-month history of cough and was found to have right sided Lactobacillus gasseri empyema for which he underwent video-assisted thoracoscopic surgery (VATS) with chest tube placement. He subsequently developed a left sided pleural empyema for which the aspiration also grew out L. gasseri. The patient made a complete recovery and was seen for four months in follow-up after his initial presentation
Effect of Gibberellic Acid on Ipomoea Batatas Regeneration From Meristem Culture.
The elongation of the explants is one of the crucial aspects in developing protocols for regeneration of sweet potato from meristem culture. In order to promote elongation and accelerate explant development, gibberellic acid (GA3) was added to the culture medium. Experimental results were strongly influenced by the cultivars employed. The effect of GA3 was to promote multiple shoot growth and elongation of cv. Mãe de FamÃlia; on the other hand, the addition of GA3 had no effect on explant growth in cv. Coração Alado
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Imaging techniques utilizing optical fibers and tomography
Two-dimensional, time-dependent images generated by neutrons, gamma rays, and x-rays incident on fast scintillators are relayed to streak and video cameras over optical fibers. Three dimensions, two spatial and one temporal, have been reduced to two, one in space and time utilizing sampling methods permitting reconstruction of a time-dependent, two-dimensional image subsequent to data recording. The manner in which the sampling is done optimized the ability to reconstruct the image via a maximization of entropy algorithm. This method uses four linear fiber optic arrays typically 30 meters long and up to 35 elements each. A further refinement of this technique collapses the linear array information into four single fibers by wavelength multiplexing. This permits economical transmission of the data over kilometer distances to the recording equipment