352 research outputs found

    Progress on the Use of Combined Analog and Photon Counting Detection for Raman Lidar

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    The Atmospheric Radiation Measurement (ARM) program Raman Lidar (CARL) was upgraded in 2004 with a new data system that provides simultaneous measurements of both the photomultiplier analog output voltage and photon counts. The so-called merge value added procedure (VAP) was developed to combine the analog and count-rate signals into a single signal with improved dynamic range. Earlier versions of this VAP tended to cause unacceptably large biases in the water vapor mixing ratio during the daytime as a result of improper matching between the analog and count-rate signals in the presence of elevated solar background levels. We recently identified several problems and tested a modified version of the merge VAP by comparing profiles of water vapor mixing ratio derived from CARL with simultaneous sonde data over a six month period. We show that the modified merge VAP significantly reduces the daytime bias, and results in mean differences that are within approximately 1% for both nighttime and daytime measurements

    The Relationship Between Investments in Intangible Resources and Liquidation for Financially Distressed Firms

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    Working with a sample of manufacturing and non-manufacturing firms that filed for bankruptcy protection between 1980 and 2009, the current study examines the relationship between investments in intangibles and the likelihood that the bankrupt firm will either be reorganized or face liquidation. Results for the manufacturing sub-sample show that R&D is the only significant variable associated with liquidation. Over-investment in R&D appears to increase the likelihood of liquidation. Similarly, results for the non-manufacturing sub-sample show that over-investment in advertising appears to increase the likelihood of liquidation. Our conclusion is that firms that are forced to liquidate are often guilty of over-investing in intangible assets

    CART Raman Lidar Aerosol and Water Vapor Measurements in the Vicinity of Clouds

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    Aerosol and water vapor profiles acquired by the Raman lidar instrument located at the Climate Research Facility (CRF) at Southern Great Plains (SGP) provide data necessary to investigate the atmospheric variability in the vicinity of clouds near the top of the planetary boundary layer (PBL). Recent CARL upgrades and modifications to the routine processing algorithms afforded the necessarily high temporal and vertical data resolutions for these investigations. CARL measurements are used to investigate the behavior of aerosol backscattering and extinction and their correlation with water vapor and relative humidity

    Arteriovenous Fistula Rescues Radial Forearm Phalloplasty: A Case Report on Patients with Microvascular Obstruction

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    Radial forearm free flap phalloplasty (RFFFP) is the most common surgery performed for genital reconstruction of female-to-male transgender patients. However, up to 19% require anastomotic re-exploration. The postoperative creation of an arteriovenous fistula (AVF) to bypass obstruction and salvage RFFFP was first reported in 1996 and has subsequently been reported by 1 high-volume center in Belgium. Methods: Here, we present 2 cases in which intraoperative microvascular obstruction threatened the viability of the RFFF of transgender phalloplasty patients. In each patient, an AVF was created between the radial artery and cephalic vein in the distal flap either after being transferred out of the operating room, as has previously been described, or during initial operation. Results: In both cases, the creation of a distal AVF salvaged the neophallus. Importantly, the patient that had been transferred out of the operating room before reintervention suffered partial flap necrosis compared with no flap loss in the patient who had an AVF created during initial surgery. One AVF was ligated 18 days postoperative, whereas the other was never formally closed. Conclusions: These cases demonstrate that AVF can be reliably used for RFFFP salvage both intraoperatively and for reintervention. They also suggest that earlier detection of persistent vascular compromise and utilization of AVF can further minimize flap loss. Finally, in contrast with the prior explanation of this technique, timing of AVF ligation may be less critical than previously described. Microsurgeons are reminded that this technique may save complicated flaps in the uncommon case of microcirculatory flap obstruction

    Charge-charge interactions are key determinants of the pK values of ionizable groups in ribonuclease Sa (pI=3.5) and a basic variant (pI=10.2)

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    The pK values of the titratable groups in ribonuclease Sa (RNase Sa) (pI=3.5), and a charge-reversed variant with five carboxyl to lysine substitutions, 5K RNase Sa (pI=10.2), have been determined by NMR at 20 °C in 0.1 M NaCl. In RNase Sa, 18 pK values and in 5K, 11 pK values were measured. The carboxyl group of Asp33, which is buried and forms three intramolecular hydrogen bonds in RNase Sa, has the lowest pK (2.4), whereas Asp79, which is also buried but does not form hydrogen bonds, has the most elevated pK (7.4). These results highlight the importance of desolvation and charge–dipole interactions in perturbing pK values of buried groups. Alkaline titration revealed that the terminal amine of RNase Sa and all eight tyrosine residues have significantly increased pK values relative to model compounds. A primary objective in this study was to investigate the influence of charge–charge interactions on the pK values by comparing results from RNase Sa with those from the 5K variant. The solution structures of the two proteins are very similar as revealed by NMR and other spectroscopic data, with only small changes at the N terminus and in the α-helix. Consequently, the ionizable groups will have similar environments in the two variants and desolvation and charge–dipole interactions will have comparable effects on the pK values of both. Their pK differences, therefore, are expected to be chiefly due to the different charge–charge interactions. As anticipated from its higher net charge, all measured pK values in 5K RNase are lowered relative to wild-type RNase Sa, with the largest decrease being 2.2 pH units for Glu14. The pK differences (pKSa−pK5K) calculated using a simple model based on Coulomb's Law and a dielectric constant of 45 agree well with the experimental values. This demonstrates that the pK differences between wild-type and 5K RNase Sa are mainly due to changes in the electrostatic interactions between the ionizable groups. pK values calculated using Coulomb's Law also showed a good correlation (R=0.83) with experimental values. The more complex model based on a finite-difference solution to the Poisson–Boltzmann equation, which considers desolvation and charge–dipole interactions in addition to charge–charge interactions, was also used to calculate pK values. Surprisingly, these values are more poorly correlated (R=0.65) with the values from experiment. Taken together, the results are evidence that charge–charge interactions are the chief perturbant of the pK values of ionizable groups on the protein surface, which is where the majority of the ionizable groups are positioned in proteins.This work was supported by grants GM-37039 and GM-52483 from the National Institutes of Health (USA), grants BE-1060 and BE-1281 from the Robert A. Welch Foundation, and a grant PB-93-06777 to M.R. from the Dirección General de Investigación Cientı́fica y Técnica (Spain

    The effectiveness of schemes that refine referrals between primary and secondary care - the UK experience with glaucoma referrals: the Health Innovation & Education Cluster (HIEC) Glaucoma Pathways Project

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    Objectives: A comparison of glaucoma referral refinement schemes (GRRS) in the UK during a time period of considerable change in national policy and guidance. Design: Retrospective multisite review. Setting: The outcomes of clinical examinations by optometrists with a specialist interest in glaucoma (OSIs) were compared with optometrists with no specialist interest in glaucoma (non-OSIs). Data from Huntingdon and Nottingham assessed non-OSI findings, while Manchester and Gloucestershire reviewed OSI findings. Participants: 1086 patients. 434 patients were from Huntingdon, 179 from Manchester, 204 from Gloucestershire and 269 from Nottingham. Results: The first-visit discharge rate (FVDR) for all time periods for OSIs was 14.1% compared with 36.1% from non-OSIs (difference 22%, CI 16.9% to 26.7%; p<0.001). The FVDR increased after the April 2009 National Institute for Health and Clinical Excellence (NICE) glaucoma guidelines compared with pre-NICE, which was particularly evident when pre-NICE was compared with the current practice time period (OSIs 6.2–17.2%, difference 11%, CI −24.7% to 4.3%; p=0.18, non-OSIs 29.2–43.9%, difference 14.7%, CI −27.8% to −0.30%; p=0.03). Elevated intraocular pressure (IOP) was the commonest reason for referral for OSIs and non-OSIs, 28.7% and 36.1%, respectively, of total referrals. The proportion of referrals for elevated IOP increased from 10.9% pre-NICE to 28.0% post-NICE for OSIs, and from 19% to 45.1% for non-OSIs. Conclusions: In terms of ‘demand management’, OSIs can reduce FVDR of patients reviewed in secondary care; however, in terms of ‘patient safety’ this study also shows that overemphasis on IOP as a criterion for referral is having an adverse effect on both the non-OSIs and indeed the OSIs ability to detect glaucomatous optic nerve features. It is recommended that referral letters from non-OSIs be stratified for risk, directing high-risk patients straight to secondary care, and low-risk patients to OSIs

    An Association of Cancer Physicians' strategy for improving services and outcomes for cancer patients.

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    The Association of Cancer Physicians in the United Kingdom has developed a strategy to improve outcomes for cancer patients and identified the goals and commitments of the Association and its members.The ACP is very grateful to all of its members who have expressed views on the development of the strategy and to the sponsors of our workshops and publications, especially Cancer Research UK and Macmillan Cancer SupportThis is the final version of the article. It was first available from Cancer Intelligence via http://dx.doi.org/10.3332/ecancer.2016.60
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