901 research outputs found

    Facile synthesis of 7-alkyl-1,2,3,4-tetrahydro-1,8-naphthyridines as arginine mimetics using a Horner-Wadsworth-Emmons-based approach

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    Integrin inhibitors based on the tripeptide sequence Arg-Gly-Asp (RGD) are potential therapeutics for the treatment of idiopathic pulmonary fibrosis (IPF). Herein, we describe an expeditious three-step synthetic sequence of Horner-Wadsworth-Emmons olefination, diimide reduction, and global deprotection to synthesise cores for these compounds in high yields (63-83% over 3 steps) with no need for chromatography. Key to this transformation is the phosphoramidate protecting group, which is stable to metalation steps

    Aiming Higher: Results from a State Scorecard on Health System Performance, 2014

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    The Commonwealth Fund's Scorecard on State Health System Performance, 2014, assesses states on 42 indicators of health care access, quality, costs, and outcomes over the 2007–2012 period, which includes the Great Recession and precedes the major coverage expansions of the Affordable Care Act. Changes in health system performance were mixed overall, with states making progress on some indicators while losing ground on others. In a few areas that were the focus of national and state attention—childhood immunizations, hospital readmissions, safe prescribing, and cancer deaths— there were widespread gains. But more often than not, states exhibited little or no improvement. Access to care deteriorated for adults, while costs increased. Persistent disparities in performance across and within states and evidence of poor care coordination highlight the importance of insurance expansions, health care delivery reforms, and payment changes in promoting a more equitable, highquality health system

    Sex differences in spatial abilities: Methodological problems in Hoffman et al.

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    Hoffman et al. (1) claimed to provide evidence that “nurture” (i.e., residing in a patrilineal vs. matrilineal tribe in India) critically affects sex differences in spatial abilities. Unfortunately, their conclusion is undermined by major problems with their measures of spatial ability and sex equality. The first and biggest problem is with their measure of spatial abilities. “Spatial abilities” are a complex cognitive domain, with facets ranging from location memory (favoring women) to navigation in 3D virtual space (favoring men) (2). The puzzle used by Hoffman et al. (1) is similar to the Object Assembly subtest of the Wechsler Adult Intelligence Scale (3); sex differences on this task are extremely small (d = 0.10), at least 10-fold smaller than those found for spatial measures showing the largest sex differences. It is odd that Hoffman et al. (1) chose to investigate sex differences with this kind of sex-insensitive task. The second problem is the lack of a control task. The insensitivity of the task used by Hoffman et al. (1) suggests that their finding that men outperform women in a patrilineal tribe but not a matrilineal tribe is not related to sex differences in spatial abilities per se but to other factors instead. Education, as they noted, is likely one of these. The use of a cognitive control task tapping nonspatial abilities would have allowed for an assessment of the specificity of the effect, but, unfortunately, such a task was not included. Third, defining sex equality as matrilineality is problematic, because cross-cultural studies generally show that equality (a multidimensional construct) is not systematically correlated with descent system (4). From the descriptions of Hoffman et al. (1), it appears that women in the matrilineal Khasi have more economic power and better education, but this ignores other sex equality dimensions, such as positions of political and religious leadership, domestic authority, and autonomy. Without such measures, it is unclear whether the Khasi are, in fact, more sexegalitarian than the Karbi. Furthermore, a recent 53-nation cross-cultural study has shown that sex differences favoring men on validated, reliable, multi-item spatial measures are positively associated with United Nation indices of sex development and empowerment (5), a pattern opposite to that reported by Hoffman et al. (1). For all these reasons, the study by Hoffman et al. (1) failed to support their conclusions

    America's Underinsured: A State-by-State Look at Health Insurance Affordability Prior to the New Coverage Expansions

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    The Affordable Care Act insurance reforms seek to expand coverage and to improve the affordability of care and premiums. Before the implementation of the major reforms, data from U.S. census surveys indicated nearly 32 million insured people under age 65 were in households spending a high share of their income on medical care. Adding these "underinsured" people to the estimated 47.3 million uninsured, the state share of the population at risk for not being able to afford care ranged from 14 percent in Massachusetts to 36 percent to 38 percent in Idaho, Florida, Nevada, New Mexico, and Texas. Nationally, more than half of people with low incomes and 20 percent of those with middle incomes were either underinsured or uninsured in 2012. The report provides state baselines to assess changes in coverage and affordability and compare states as insurance expansions and market reforms are implemented.

    GRAVITY: the Calibration Unit

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    We present in this paper the design and characterisation of a new sub-system of the VLTI 2nd generation instrument GRAVITY: the Calibration Unit. The Calibration Unit provides all functions to test and calibrate the beam combiner instrument: it creates two artificial stars on four beams, and dispose of four delay lines with an internal metrology. It also includes artificial stars for the tip-tilt and pupil guiding systems, as well as four metrology pick-up diodes, for tests and calibration of the corresponding sub-systems. The calibration unit also hosts the reference targets to align GRAVITY to the VLTI, and the safety shutters to avoid the metrology light to propagate in the VLTI-lab. We present the results of the characterisation and validtion of these differrent sub-units.Comment: 12 pages, 11 figures. Proceeding of SPIE 9146 "Optical and Infrared Interferometry IV

    The Arclight vs. traditional ophthalmoscope:a cross-over trial

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    BACKGROUND/OBJECTIVES: To compare skill acquisition of the new, cost-effective Arclight ophthalmoscope, with the traditional ophthalmoscope (TO), in medical students with no prior experience of ophthalmoscopy. SUBJECTS/METHODS: University of Dundee medical students took part in a cross-over trial. Students were divided into two groups and were alternately taught each device using a video tutorial. In period one, Group A was taught the TO first; Group B was taught the Arclight. They were then assessed using simulated objective, structured, clinical, examinations, examining four model heads with lettered fundal photographs of varying sizes of font. Groups crossed over following a 2-week washout period and were taught the second device and reassessed. A questionnaire was distributed to ascertain students’ opinions and preferences. RESULTS: Forty medical students participated. Overall, 92.5% of students performed better with the Arclight, irrespective of cross-over trial period. The mean difference in score in period one of the cross-over trial was 16.77 (95% CI: 11.63–21.93), with students performing better with the Arclight (p < 0.0001). The mean difference in score in period two was 8.02 (95% CI: 4.52–11.52), with students performing better with the Arclight (p < 0.0001). In addition, performance with the TO improved by 52.9% following initial exposure to the Arclight. The Arclight was the preferred device by 82.5% of students, and 82.5% of students would choose this device for future practice. CONCLUSION: Students performed better with and preferred the Arclight ophthalmoscope. The Arclight could be considered as a suitable alternative to the TO used for training medical students

    The GRAVITY metrology system: modeling a metrology in optical fibers

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    GRAVITY is the second generation VLT Interferometer (VLTI) instrument for high-precision narrow-angle astrometry and phase-referenced interferometric imaging. The laser metrology system of GRAVITY is at the heart of its astrometric mode, which must measure the distance of 2 stars with a precision of 10 micro-arcseconds. This means the metrology has to measure the optical path difference between the two beam combiners of GRAVITY to a level of 5 nm. The metrology design presents some non-common paths that have consequently to be stable at a level of 1 nm. Otherwise they would impact the performance of GRAVITY. The various tests we made in the past on the prototype give us hints on the components responsible for this error, and on their respective contribution to the total error. It is however difficult to assess their exact origin from only OPD measurements, and therefore, to propose a solution to this problem. In this paper, we present the results of a semi-empirical modeling of the fibered metrology system, relying on theoretical basis, as well as on characterisations of key components. The modeling of the metrology system regarding various effects, e.g., temperature, waveguide heating or mechanical stress, will help us to understand how the metrology behave. The goals of this modeling are to 1) model the test set-ups and reproduce the measurements (as a validation of the modeling), 2) determine the origin of the non-common path errors, and 3) propose modifications to the current metrology design to reach the required 1nm stability.Comment: 20 pages, 19 figures. Proceeding of SPIE 9146 "Optical and Infrared Interferometry IV
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