NASA Astrophysics Data System (ADS)
Silberman, Donn
2006-08-01
Much work has been done in efforts to reach students in the K-12 grades to encourage them to learn about optics and related sciences and technologies. One goal of these efforts is to develop the future optical scientists and engineers to carry on the work of this and related societies. One main obstacle is to create low costs novel and effective hands-on optical components and systems for these students to use and from which to get excited. Students at different grade levels and abilities are receptive to different kinds of components and systems and this must be taken into account when preparing for outreach programs. There are, however, some guiding principles which can be used throughout the various levels, including making sure the components and systems are good examples and not marginal. Small telescopes or microscopes that use poor quality optics which provide poor quality images do more to discourage young students from going into the sciences than if they never had the experience at all. Some examples of both poor and good quality optical components and systems that will be described and demonstrated include: lenses, telescopes, microscopes, diffraction gratings, Kaleidoscopes, Fresnel Lenses, polarization filters and liquid crystals. The figures in this paper are in color and best viewed on-line or printed with a good color printer.
Image quality on the Kuiper Airborne Observatory. I - Results of the first flight series
NASA Technical Reports Server (NTRS)
Elliot, J. L.; Dunham, E. W.; Baron, R. L.; Watts, A. W.; Kruse, S. E.; Rose, W. C.; Gillespie, C. M., Jr.
1989-01-01
The NASA Kuiper Airborne Observatory (KAO) was flown three times during June and July, 1984 in order to study the causes of the poor seeing obtained with the 0.9-m telescope. High-speed pressure and temperature sensors were placed in the telescope cavity. Several thousand stellar images were recorded under various flight and optical configurations. It is found that the long-exposure image size is affected by telescope tracking errors, imperfect optics, poor optical alignment, telescope and instrument vibration, thermal fluctuations in the telescope cavity, and density fluctuations in the shear layer that forms the boundary between the cavity air and outside air. Possible ways to improve the quality of the images are discussed.
Beam collimation and focusing and error analysis of LD and fiber coupling system based on ZEMAX
NASA Astrophysics Data System (ADS)
Qiao, Lvlin; Zhou, Dejian; Xiao, Lei
2017-10-01
Laser diodde has many advantages, such as high efficiency, small volume, low cost and easy integration, so it is widely used. Because of its poor beam quality, the application of semiconductor laser has also been seriously hampered. In view of the poor beam quality, the ZEMAX optical design software is used to simulate the far field characteristics of the semiconductor laser beam, and the coupling module of the semiconductor laser and the optical fiber is designed and optimized. And the beam is coupled into the fiber core diameter d=200µm, the numerical aperture NA=0.22 optical fiber, the output power can reach 95%. Finally, the influence of the three docking errors on the coupling efficiency during the installation process is analyzed.
Optical aberrations, retinal image quality and eye growth: Experimentation and modeling
NASA Astrophysics Data System (ADS)
Tian, Yibin
2007-12-01
Retinal image quality is important for normal eye growth. Optical aberrations are of interest for two reasons: first, they degrade retinal images; second, they might provide some cues to defocus. Higher than normal ocular aberrations have been previously associated with human myopia. However, these studies were cross-sectional in design, and only reported aberrations in terms of root mean square (RMS) errors of Zernike coefficients, a poor metric of optical quality. This dissertation presents results from investigations of ocular optical aberrations, retinal image quality and eye growth in chicks and humans. A number of techniques were utilized, including Shack-Hartmann aberrometry, high-frequency A-scan ultrasonography, ciliary nerve section (CNX), photorefractive keratectomy (PRK) as well as computer simulations and modeling. A technique to extract light scatter information from Shack-Hartmann images was also developed. The main findings of the dissertation are summarized below. In young chicks, most ocular aberrations decreased with growth in both normal and CNX eyes, and there were diurnal fluctuations in some aberrations. Modeling suggested active reduction in higher order aberrations (HOAs) during early development. Although CNX eyes manifested greater than normal HOAs, they showed near normal growth. Retinal image degradation varied greatly among individual eyes post-PRK in young chicks. Including light scatter information into analyses of retinal image quality better estimated the latter. Albino eyes showed more severe retinal image degradation than normal eyes, due to increased optical aberrations and light scatter, but their growth was similar to those of normal eyes, implying that they are relatively insensitive to retina image quality. Although the above results questioned the influence of optical aberrations on early ocular growth, some optical quality metrics, derived from optical aberrations data, could predict how much the eyes of young chicks subsequently elongated. The performance of some focus measures was very poor when non-defocus aberrations exceeded a certain level; presumably, these non-defocus aberrations might interfere with the eye's ability to interpret defocus. In anisomyopic human adults, more myopic eyes had larger anterior and vitreous chambers, greater astigmatism, and more positive spherical aberration. However, compared to isometropes, only interocular differences in spherical equivalent refractive errors were significantly increased.
Center for the Integration of Optical Computing
1993-10-15
medium-high-speed two- beam coupling that could be used in systems as an all- optical interconnect. The basis of our studies was the fact that operating at...to investigate near-band edge photorefractivity for optical interconnects, at least when used at small beam ratio or in phase conjugate resonators. I...field pattern a mess. Their poor beam quality makes laser diode arrays ill suited for many applications, such as launching intense light into single
Challenges in the management of glaucoma in developing countries.
Butt, Nadeem Hafeez; Ayub, Muhammad Hammad; Ali, Muhammad Hassaan
2016-01-01
Glaucoma is the most common optic neuropathy characterized by normal to raised intraocular pressure (IOP), visual field defects, loss of retinal nerve fiber layer, thinning of the neuroretinal rim, and cupping of the optic disc. IOP reduction by medical, laser, or surgical therapies remains the only clinically proven treatment of glaucoma. The challenges in glaucoma management are diverse. They include early detection and diagnosis, setting of appropriate target IOP, choice of treatment, monitoring of quality of life and sight, and compliance with the treatment. Early diagnosis can be made by assessing optic nerve structure using imaging devices and optic nerve function through perimetry. Reducing IOP and controlling its fluctuations are considered to be the most important factors in limiting progression of glaucoma. Selection of the best suitable therapy out of medical, surgical, or laser treatment options is yet another management challenge. Patients suffering from glaucoma experience poor quality of life owing to the diagnosis itself, functional visual loss, inconvenience and cost of treatment, and side effects of treatment. All these factors lead to poor compliance, adherence, and persistence to treatment, and further progression of the disease. It is, therefore, important that ophthalmologists keep all the aforementioned factors in mind when managing patients with glaucoma.
2004-07-29
coherent coupling in large element arrays . 16 Characterisation of Picosecond Pulses Propagating through a Semiconductor Optical Amplifier...Effect is used. QSCE is widely used in optical intensity and phase modula- Oiz et • to tors [i]. The speed of reverse-biased devices is po- tentially...such devices generally have poor beam quality . The out-of- phase mode is In fact typically favoured in these devices because of the better
NASA Astrophysics Data System (ADS)
Cohen, Lori A.
1995-12-01
Kodak Optical Products has embarked on a journey that will ultimately lead to manufacturing excellence and total customer satisfaction. With quality as our compass we have already obtained ISO 9001 and Manufacturing Resource Planning (MRP) II certifications. Seeking and attaining these certifications enabled us to understand and enhance fundamentals relative to the operation of our business. This has provided a solid foundation from which we can launch continuous improvement activities. Now we continue our journey to such destinations as 10X reduction in both defects and cycle time, measuring and reducing our cost of poor quality, and upgrading our quality information system. Our presentation will emphasize our 10X improvement process and how it applies to high-volume production of precision plastic optics.
STS-107 Debris Characterization Using Re-entry Imaging
NASA Technical Reports Server (NTRS)
Raiche, George A.
2009-01-01
Analysis of amateur video of the early reentry phases of the Columbia accident is discussed. With poor video quality and little theoretical guidance, the analysis team estimated mass and acceleration ranges for the debris shedding events observed in the video. Camera calibration and optical performance issues are also described.
Dark Skies Preservation through Responsible Lighting: the IYL2015 Quality Lighting Kit
NASA Astrophysics Data System (ADS)
Walker, Constance E.
2015-01-01
Poor quality lighting not only impedes astronomy research, but creates safety issues, affects human circadian sensitivities, disrupts ecosystems, and wastes more than a few billion dollars/year of energy in the USA alone. The United Nations-sanctioned the International Year of Light in 2015 (IYL2015) is providing an opportunity to increase public awareness of dark skies preservation, quality lighting and energy conservation. The Education and Public Outreach (EPO) group at the National Optical Astronomy Observatory (NOAO) has received a small grant through the International Astronomical Union (IAU) to produce official 'Quality Lighting Teaching Kits' for the IYL2015 cornerstone theme, 'Cosmic Light'. These kits will emphasize the use of proper optical design in achieving quality lighting that promotes both energy efficiency and energy conservation of an endangered natural resource, our dark skies. The concepts and practice of 'quality lighting' will be explored through demonstrations, hands-on/minds-on activities, formative assessment probes, and engineering design projects that explore basic principles of optics and the physics of light. The impact of the kits will be amplified by providing professional development using tutorial videos created at NOAO and conducting question and answer sessions via Google+ Hangouts for the outreach volunteers. The quality lighting education program will leverage NOAO EPO's work in the last ten years on lighting and optics education (e.g., the IAU 'Dark Skies Africa', APS 'Dark Skies Yuma' and 'Hands-On Optics' programs). NOAO's partners are CIE (International Commission on Illumination), IDA (International Dark-Sky Association) and SPIE (International Society for Optics and Photonics), as well as the IAU Office of Astronomy for Development, Galileo Teacher Training Program, Universe Awareness, and Global Hands-on Universe. Their networks will disseminate the program and kits to formal and informal audiences worldwide. The impact sought is a change in knowledge, attitude, and behavior in each community by learning how to light responsibly, improving the quality of life in 'illuminating' ways.
High speed color imaging through scattering media with a large field of view
NASA Astrophysics Data System (ADS)
Zhuang, Huichang; He, Hexiang; Xie, Xiangsheng; Zhou, Jianying
2016-09-01
Optical imaging through complex media has many important applications. Although research progresses have been made to recover optical image through various turbid media, the widespread application of the technology is hampered by the recovery speed, requirement on specific illumination, poor image quality and limited field of view. Here we demonstrate that above-mentioned drawbacks can be essentially overcome. The realization of high speed color imaging through turbid media is successfully carried out by taking into account the media memory effect, the point spread function, the exit pupil of the optical system, and the optimized signal to noise ratio. By retrieving selected speckles with enlarged field of view, high quality image is recovered with a responding speed only determined by the frame rates of the image capturing devices. The immediate application of the technique is expected to register static and dynamic imaging under human skin to recover information with a wearable device.
NASA Astrophysics Data System (ADS)
Fan, Yingmin; Wang, Jingwei; Cai, Lei; Mitra, Thomas; Hauschild, Dirk; Zah, Chung-En; Liu, Xingsheng
2018-02-01
High power diode lasers (HPDLs) offer the highest wall-plug efficiency, highest specific power (power-to-weight ratio), arguably the lowest cost and highest reliability among all laser types. However, the poor beam quality of commercially HPDLs is the main bottleneck limiting their direct applications requiring high brightness at least in one dimension. In order to expand the applications of HPDLs, beam shaping and optical design are essential. In this work, we report the recent progresses on maximizing applications of HPDLs by synergizing diode laser light source and beam shaping micro-optics. Successful examples of matching of diode laser light sources and beam shaping micro-optics driving new applications are presented.
NASA Astrophysics Data System (ADS)
Jermyn, Michael; Ghadyani, Hamid; Mastanduno, Michael A.; Turner, Wes; Davis, Scott C.; Dehghani, Hamid; Pogue, Brian W.
2013-08-01
Multimodal approaches that combine near-infrared (NIR) and conventional imaging modalities have been shown to improve optical parameter estimation dramatically and thus represent a prevailing trend in NIR imaging. These approaches typically involve applying anatomical templates from magnetic resonance imaging/computed tomography/ultrasound images to guide the recovery of optical parameters. However, merging these data sets using current technology requires multiple software packages, substantial expertise, significant time-commitment, and often results in unacceptably poor mesh quality for optical image reconstruction, a reality that represents a significant roadblock for translational research of multimodal NIR imaging. This work addresses these challenges directly by introducing automated digital imaging and communications in medicine image stack segmentation and a new one-click three-dimensional mesh generator optimized for multimodal NIR imaging, and combining these capabilities into a single software package (available for free download) with a streamlined workflow. Image processing time and mesh quality benchmarks were examined for four common multimodal NIR use-cases (breast, brain, pancreas, and small animal) and were compared to a commercial image processing package. Applying these tools resulted in a fivefold decrease in image processing time and 62% improvement in minimum mesh quality, in the absence of extra mesh postprocessing. These capabilities represent a significant step toward enabling translational multimodal NIR research for both expert and nonexpert users in an open-source platform.
The Quality Lighting Teaching Kit: Educating the Public about the Dark Side of IYL2015
NASA Astrophysics Data System (ADS)
Walker, Constance Elaine; Pompea, Stephen M.; Levy, Rebecca
2015-08-01
The UN-sanctioned International Year of Light in 2015 (IYL2015) is providing an opportunity to increase public awareness of dark skies preservation, quality lighting and energy conservation. The Education and Public Outreach (EPO) group at the U.S. National Optical Astronomy Observatory (NOAO) has received a grant through the IAU to produce official “Quality Lighting Teaching Kits” for the IYL2015 cornerstone theme, “Cosmic Light”. These kits will emphasize the use of proper optical design in achieving quality lighting that promotes both energy efficiency and energy conservation of an endangered natural resource: our dark skies. Poor quality lighting not only impedes astronomy research, but creates safety issues, affects human circadian sensitivities, disrupts ecosystems, and wastes billions of dollars/year in energy consumption and carbon emissions.The concepts and practices of “quality lighting” will be explored through problem-based learning (e.g., engineering design), hands-on/minds-on activities, demonstrations, and formative and summative assessment probes. The impact of the kits will be amplified by providing professional development using tutorial videos created at NOAO and conducting question and answer sessions via Google+ Hangouts for program participants. The Quality Lighting Teaching Kit will leverage ten years of work by NOAO’s EPO team in developing programs on lighting and optics education (e.g., the NSF-funded “Hands on Optics”, IAU “Dark Skies Africa” and Arizona Public Service Foundation’s “Dark Skies Yuma” programs).NOAO’s partners are the International Society for Optics and Photonics (SPIE), International Commission on Illumination (CIE), International Dark-Sky Association (IDA), and IAU Office of Astronomy for Development, with sponsorship from the IAU and The Optical Society (OSA). Along with astronomy education centers (NUCLIO and Universe Awareness), the networks will disseminate kits to formal and informal audiences worldwide. The impact sought is a change in knowledge, attitude, and behavior in each community by learning how to light responsibly, improving the quality of life in “illuminating” ways.
Thermal/structural/optical integrated design for optical sensor mounted on unmanned aerial vehicle
NASA Astrophysics Data System (ADS)
Zhang, Gaopeng; Yang, Hongtao; Mei, Chao; Wu, Dengshan; Shi, Kui
2016-01-01
With the rapid development of science and technology and the promotion of many local wars in the world, altitude optical sensor mounted on unmanned aerial vehicle is more widely applied in the airborne remote sensing, measurement and detection. In order to obtain high quality image of the aero optical remote sensor, it is important to analysis its thermal-optical performance on the condition of high speed and high altitude. Especially for the key imaging assembly, such as optical window, the temperature variation and temperature gradient can result in defocus and aberrations in optical system, which will lead to the poor quality image. In order to improve the optical performance of a high speed aerial camera optical window, the thermal/structural/optical integrated design method is developed. Firstly, the flight environment of optical window is analyzed. Based on the theory of aerodynamics and heat transfer, the convection heat transfer coefficient is calculated. The temperature distributing of optical window is simulated by the finite element analysis software. The maximum difference in temperature of the inside and outside of optical window is obtained. Then the deformation of optical window under the boundary condition of the maximum difference in temperature is calculated. The optical window surface deformation is fitted in Zernike polynomial as the interface, the calculated Zernike fitting coefficients is brought in and analyzed by CodeV Optical Software. At last, the transfer function diagrams of the optical system on temperature field are comparatively analyzed. By comparing and analyzing the result, it can be obtained that the optical path difference caused by thermal deformation of the optical window is 138.2 nm, which is under PV ≤1 4λ . The above study can be used as an important reference for other optical window designs.
The effects of optical sensor-tissue separation in endocavitary photoplethysmography.
Patel, Zaibaa; Thaha, Mohamed A; Kyriacou, Panayiotis A
2018-06-12
<i>Objective:</i> Intestinal anastomotic failure that occurs mainly due to ischaemia is a serious risk in colorectal cancer patients undergoing surgery. Surgeons continue to rely on subjective methods such as visual inspection to assess intestinal viability during surgery and there are no clinical tools to directly monitor viability postoperatively. A dual wavelength, reflectance optical sensor has been developed for continuous and dynamic monitoring of intestinal viability via the intestinal lumen. Maintaining direct contact between the sensor and the inner intestinal wall can be difficult in an intraluminal design, therefore impacting on signal acquisition and quality. This paper investigates the effect of direct contact versus variable distances between the sensor and the tissue surface of the buccal mucosa as a surrogate. <i>Approach:</i> The <i>in-vivo</i> study involved 20 healthy volunteers to measure the effect of optical sensor-tissue distances on the ability to acquire photoplethysmography signals and their quality. Signals were acquired from the buccal mucosa at five optical sensor-tissue distances. <i>Main results:</i> Distances between 0 mm (contact) to 5 mm were the most optimal, producing signals of high quality and signal-to-noise ratio, resulting in reliable estimations of the blood oxygen saturation. Distances exceeding 5 mm compromised the acquired signals, and were of poor quality, thereby unreliably estimating the blood oxygen saturation. <i>Significance:</i> The developed optical sensor proved to be reliable for acquiring photoplethysmography signals for cases where distances between the optical sensor-tissue may arise during the assessment of intraluminal intestinal viability. © 2018 Institute of Physics and Engineering in Medicine.
Assessment of different methods to estimate bovine colostrum quality on farm.
Bartens, M-C; Drillich, M; Rychli, K; Iwersen, M; Arnholdt, T; Meyer, L; Klein-Jöbstl, D
2016-09-01
To evaluate two different hydrometers and an optical and a digital Brix refractometer for the assessment of bovine colostrum quality, in terms of accuracy and precision compared with the measurement of IgG concentrations using radial immunodiffusion (RID), and to evaluate the reliability and repeatability of the Brix refractometers. To determine reliability and repeatability, 145 colostrum samples were tested by two independent observers twice, using the optical and digital Brix refractometers. A further 193 colostrum samples from Holstein cows were collected on one commercial dairy farm at first milking and tested with two hydrometers and an optical and digital Brix refractometer. An aliquot of each sample was frozen for RID measurement of IgG concentrations and samples were classified as poor (≤50 g IgG/L) or good (>50 g IgG/L) quality colostrum. Intraclass correlation coefficients (ICC) were used to determine inter- and intra-observer reliability and repeatability. Optimised cut-off values for the four devices were determined using receiver operating characteristics (ROC) analysis with the RID results as the reference. Using these cut-offs, sensitivities and specificities for determining good quality colostrum were calculated. The ICC for inter-observer reliability was 0.98 for the optical Brix refractometer, and for intra-observer repeatability was 0.97 and 0.98 for the optical and the digital Brix refractometers, respectively. For the 193 colostrum samples, 67 (34.7%) had concentrations of IgG ≤50 g/L determined by RID. Optimised cut-off values evaluated by ROC analysis were higher for all devices compared with manufacturer reference or previously published values. Using these values, the sensitivities for the two hydrometers, and the optical and the digital Brix refractometers were 0.73, 0.71, 0.56 and 0.79, respectively; specificities were 0.72, 0.61, 0.90 and 0.69, respectively. The Brix refractometers provided the most accurate assessment of colostrum quality of the devices evaluated, and demonstrated excellent precision in terms of repeatability. To provide optimal health for newborn calves, a sufficient intake of good quality colostrum is essential. The Brix refractometers provide rapid, convenient tools for classification of colostrum quality.
Nonlinear filtering for character recognition in low quality document images
NASA Astrophysics Data System (ADS)
Diaz-Escobar, Julia; Kober, Vitaly
2014-09-01
Optical character recognition in scanned printed documents is a well-studied task, where the captured conditions like sheet position, illumination, contrast and resolution are controlled. Nowadays, it is more practical to use mobile devices for document capture than a scanner. So as a consequence, the quality of document images is often poor owing to presence of geometric distortions, nonhomogeneous illumination, low resolution, etc. In this work we propose to use multiple adaptive nonlinear composite filters for detection and classification of characters. Computer simulation results obtained with the proposed system are presented and discussed.
Optical properties of the mouse eye
Geng, Ying; Schery, Lee Anne; Sharma, Robin; Dubra, Alfredo; Ahmad, Kamran; Libby, Richard T.; Williams, David R.
2011-01-01
The Shack-Hartmann wavefront sensor (SHWS) spots upon which ocular aberration measurements depend have poor quality in mice due to light reflected from multiple retinal layers. We have designed and implemented a SHWS that can favor light from a specific retinal layer and measured monochromatic aberrations in 20 eyes from 10 anesthetized C57BL/6J mice. Using this instrument, we show that mice are myopic, not hyperopic as is frequently reported. We have also measured longitudinal chromatic aberration (LCA) of the mouse eye and found that it follows predictions of the water-filled schematic mouse eye. Results indicate that the optical quality of the mouse eye assessed by measurement of its aberrations is remarkably good, better for retinal imaging than the human eye. The dilated mouse eye has a much larger numerical aperture (NA) than that of the dilated human eye (0.5 NA vs. 0.2 NA), but it has a similar amount of root mean square (RMS) higher order aberrations compared to the dilated human eye. These measurements predict that adaptive optics based on this method of wavefront sensing will provide improvements in retinal image quality and potentially two times higher lateral resolution than that in the human eye. PMID:21483598
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sontheimer, Tobias, E-mail: tobias.sontheimer@helmholtz-berlin.de; Schnegg, Alexander; Lips, Klaus
2013-11-07
By employing electron paramagnetic resonance spectroscopy, transmission electron microscopy, and optical measurements, we systematically correlate the structural and optical properties with the deep-level defect characteristics of various tailored periodic Si microhole arrays, which are manufactured in an easily scalable and versatile process on nanoimprinted sol-gel coated glass. While tapered microhole arrays in a structured base layer are characterized by partly nanocrystalline features, poor electronic quality with a defect concentration of 10{sup 17} cm{sup −3} and a high optical sub-band gap absorption, planar polycrystalline Si layers perforated with periodic arrays of tapered microholes are composed of a compact crystalline structure and amore » defect concentration in the low 10{sup 16} cm{sup −3} regime. The low defect concentration is equivalent to the one in planar state-of-the-art solid phase crystallized Si films and correlates with a low optical sub-band gap absorption. By complementing the experimental characterization with 3-dimensional finite element simulations, we provide the basis for a computer-aided approach for the low-cost fabrication of novel high-quality structures on large areas featuring tailored opto-electronic properties.« less
Satellite remote sensing of air quality in winter of Lanzhou
NASA Astrophysics Data System (ADS)
Wang, Dawei; Han, Tao; Jiang, Youyan; Li, Lili; Ren, Shuyuan
2018-03-01
Fine particulate matter (aerodynamic diameters of less than 2.5 μm, PM2.5) air pollution has become one of the global environmental problem, endangering the existence of residents living, climate, and public health. Estimation Particulate Matter (aerodynamic diameters of less than 10 μm, PM10) concentration and aerosol absorption was the key point in air quality and climate studies. In this study, we retrieve the Aerosol Optical Depth (AOD) from the Earth Observing System (EOS) and the Moderate Resolution Imaging Spectroradiometer (MODIS), and PM2.5, PM10 in winter on 2014 and 2015, using Extended Dense Dark Vegetation Algorithm and 6S radiation model to analysis the correlation. The result showed that at the condition of non-considering the influence of primary pollutants, the correlation of two Polynomials between aerosol optical depth and PM2.5 and PM10 was poor; taking the influence of the primary pollutants into consideration, the aerosol optical depth has a good correlation with PM2.5 and PM10. The version of PM10 by aerosol optical depth is higher than that of PM2.5, so the model can be used to realize the high precision inversion of winter PM10 in Lanzhou.
Gram-scale synthesis of single-crystalline graphene quantum dots with superior optical properties.
Wang, Liang; Wang, Yanli; Xu, Tao; Liao, Haobo; Yao, Chenjie; Liu, Yuan; Li, Zhen; Chen, Zhiwen; Pan, Dengyu; Sun, Litao; Wu, Minghong
2014-10-28
Graphene quantum dots (GQDs) have various alluring properties and potential applications, but their large-scale applications are limited by current synthetic methods that commonly produce GQDs in small amounts. Moreover, GQDs usually exhibit polycrystalline or highly defective structures and thus poor optical properties. Here we report the gram-scale synthesis of single-crystalline GQDs by a facile molecular fusion route under mild and green hydrothermal conditions. The synthesis involves the nitration of pyrene followed by hydrothermal treatment in alkaline aqueous solutions, where alkaline species play a crucial role in tuning their size, functionalization and optical properties. The single-crystalline GQDs are bestowed with excellent optical properties such as bright excitonic fluorescence, strong excitonic absorption bands extending to the visible region, large molar extinction coefficients and long-term photostability. These high-quality GQDs can find a large array of novel applications in bioimaging, biosensing, light emitting diodes, solar cells, hydrogen production, fuel cells and supercapacitors.
An Algorithm for Pedestrian Detection in Multispectral Image Sequences
NASA Astrophysics Data System (ADS)
Kniaz, V. V.; Fedorenko, V. V.
2017-05-01
The growing interest for self-driving cars provides a demand for scene understanding and obstacle detection algorithms. One of the most challenging problems in this field is the problem of pedestrian detection. Main difficulties arise from a diverse appearances of pedestrians. Poor visibility conditions such as fog and low light conditions also significantly decrease the quality of pedestrian detection. This paper presents a new optical flow based algorithm BipedDetet that provides robust pedestrian detection on a single-borad computer. The algorithm is based on the idea of simplified Kalman filtering suitable for realization on modern single-board computers. To detect a pedestrian a synthetic optical flow of the scene without pedestrians is generated using slanted-plane model. The estimate of a real optical flow is generated using a multispectral image sequence. The difference of the synthetic optical flow and the real optical flow provides the optical flow induced by pedestrians. The final detection of pedestrians is done by the segmentation of the difference of optical flows. To evaluate the BipedDetect algorithm a multispectral dataset was collected using a mobile robot.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Walker, Bennett N., E-mail: bennett.walker@fda.hhs.gov; Office of Device Evaluation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993; James, Robert H.
Glare, glistenings, optical defects, dysphotopsia, and poor image quality are a few of the known deficiencies of intraocular lenses (IOLs). All of these optical phenomena are related to light scatter. However, the specific direction that light scatters makes a critical difference between debilitating glare and a slightly noticeable decrease in image quality. Consequently, quantifying the magnitude and direction of scattered light is essential to appropriately evaluate the safety and efficacy of IOLs. In this study, we introduce a full-angle scanning light scattering profiler (SLSP) as a novel approach capable of quantitatively evaluating the light scattering from IOLs with a nearlymore » 360° view. The SLSP method can simulate in situ conditions by controlling the parameters of the light source including angle of incidence. This testing strategy will provide a more effective nonclinical approach for the evaluation of IOL light scatter.« less
Direct composite fillings: an optical coherence tomography and microCT investigation
NASA Astrophysics Data System (ADS)
Negrutiu, Meda L.; Sinescu, Cosmin; Borlea, Mugurel V.; Manescu, Adrian; Duma, Virgil F.; Rominu, Mihai; Podoleanu, Adrian G.
2015-03-01
The treatment of carious lesions requires removal of affected dental tissue thus creating cavities that are to be filled with dedicated materials. There are several methods known which are used to assess the quality of direct dental restorations, but most of them are invasive. Optical tomographic techniques are of particular importance in the medical imaging field, because these techniques can provide non-invasive diagnostic images. Using an en-face version of OCT, we have recently demonstrated real time thorough evaluation of quality of dental fillings. The major aim of this study was to analyses the optical performance of adhesives modified with zirconia particles in different concentrations in order to improve the contrast of OCT imaging of the interface between the tooth structure, adhesive and composite resin. The OCT investigations were validated by micro CT using synchrotron radiation. The OCT Swept Source is a valuable investigation tool for the clinical evaluation of class II direct composite restorations. The unmodified adhesive layer shows poor contrast on regular OCT investigations. Adding zirconia particles to the adhesive layer provides a better scattering which allows a better characterization and quantification of direct restorations.
In situ optical water-quality sensor networks - Workshop summary report
Pellerin, Brian A.; Bergamaschi, Brian A.; Horsburgh, Jeffery S.
2012-01-01
Advanced in situ optical water-quality sensors and new techniques for data analysis hold enormous promise for furthering scientific understanding of aquatic systems. These sensors measure important biogeochemical parameters for long deployments, enabling the capture of data at time scales over which they vary most meaningfully. The high-frequency, real-time water-quality data they generate provide opportunities for early warning of water-quality deterioration, trend detection, and science-based decision support. However, developing networks of optical sensors in freshwater systems that report reliable and comparable data across and between sites remains a challenge to the research and monitoring community. To address this, the U. S. Geological Survey (USGS) and the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) convened a joint 3-day workshop (June 8-10, 2011) at the National Conservation Training Center in Shepardstown, West Virginia, to explore ways to coordinate development of standards and applications for optical sensors, and improve handling, storing, and analyzing the continuous data they produce. The workshop brought together more than 60 scientists, program managers, and vendors from universities, government agencies, and the private sector. Several important outcomes emerged from the presentations and breakout sessions. There was general consensus that making intercalibrated measurements requires that both manufacturers and users better characterize and calibrate the sensors under field conditions. For example, the influence of suspended particles, highly colored water, and temperature on optical sensors remains poorly understood, but consistently accounting for these factors is critical to successful deployment and for interpreting results in different settings. This, in turn, highlights the lack of appropriate standards for sensor calibrations, field checks, and characterizing interferences, as well as methods for data validation, treatment, and analysis of resulting measurements. Participants discussed a wide range of logistical considerations for successful sensor deployments, including key physical infrastructure, data loggers, and remote-communication techniques. Tools to manage, assure, and control quality, and explore large streams of continuous water-quality data are being developed by the USGS, CUAHSI, and other organizations, and will be critical to making full use of these highfrequency data for research and monitoring.
Effect of Number of Zones on Subjective Vision in Concentric Bifocal Optics.
Legras, Richard; Rio, David
2015-11-01
To evaluate the influence of the number of concentric zones of a center-near bifocal optics on the subjective quality of vision. Twenty-two subjects scored with a five-item continuous grading scale the quality of vision of calculated images (i.e., three high-contrast 20/50 letters) viewed through their best sphero-cylindrical correction and a 3-mm pupil to limit the impact of their aberrations. Through-focus images were calculated from -4 to +2 diopters (D), each 0.25 D, in the presence of center-near bifocal optics (Add 2.5 D) varying by their number of concentric zones (from 2 to 20). To compare the results obtained with these profiles, we calculated the area under the (through-focus) curve (AUC) higher than 2 out of 5 (i.e., limit between a poor and a fair image quality, considered as the limit of acceptability). This value was normalized by the naked eye condition and divided into distance, intermediate, and near AUC. The results showed large interindividual variations. Distance AUC remained quite similar whatever the profile, near AUC decreased with the number of concentric zones, and intermediate AUC rose with the number of concentric zones. With 10 and 20 concentric zones, diffraction phenomenon induced constructive interferences at intermediate proximities and destructive interferences at distance and near proximities. To balance distance, intermediate, and near quality of vision, a number of zones between 8 and 10 should be chosen. If the subject does not need intermediate quality of vision, then a profile with two to five zones should be favored.
Coaxial fundus camera for opthalmology
NASA Astrophysics Data System (ADS)
de Matos, Luciana; Castro, Guilherme; Castro Neto, Jarbas C.
2015-09-01
A Fundus Camera for ophthalmology is a high definition device which needs to meet low light illumination of the human retina, high resolution in the retina and reflection free image1. Those constraints make its optical design very sophisticated, but the most difficult to comply with is the reflection free illumination and the final alignment due to the high number of non coaxial optical components in the system. Reflection of the illumination, both in the objective and at the cornea, mask image quality, and a poor alignment make the sophisticated optical design useless. In this work we developed a totally axial optical system for a non-midriatic Fundus Camera. The illumination is performed by a LED ring, coaxial with the optical system and composed of IR of visible LEDs. The illumination ring is projected by the objective lens in the cornea. The Objective, LED illuminator, CCD lens are coaxial making the final alignment easily to perform. The CCD + capture lens module is a CCTV camera with autofocus and Zoom built in, added to a 175 mm focal length doublet corrected for infinity, making the system easily operated and very compact.
Ion beam sputter coatings for laser technology
NASA Astrophysics Data System (ADS)
Ristau, Detlev; Gross, Tobias
2005-09-01
The initial motivation for the development of Ion Beam Sputtering (IBS) processes was the need for optical coatings with extremely low optical scatter losses for laser gyros. Especially, backscattering of the gyro-mirrors couples the directional modes in the ring resonator leading to the lock in effect which limits the sensitivity of the gyro. Accordingly, the first patent on IBS was approved for an aircraft company (Litton) in 1978. In the course of the rapid development of the IBS-concept during the last two decades, an extremely high optical quality could be achieved for laser coatings in the VIS- and NIR-spectral region. For example, high reflecting coatings with total optical losses below 1 ppm were demonstrated for specific precision measurement applications with the Nd:YAG-laser operating at 1.064 μm. Even though the high quality level of IBS-coatings had been confirmed in many applications, the process has not found its way into the production environment of most optical companies. Major restrictions are the relatively low rate of the deposition process and the poor lateral homogeneity of the coatings, which are related to the output characteristics of the currently available ion sources. In the present contribution, the basic principles of IBS will be discussed in the context of the demands of modern laser technology. Besides selected examples for special applications of IBS, aspects will be presented for approaches towards rapid manufacturing of coatings and the production of rugate filters on the basis of IBS-techniques.
NASA Astrophysics Data System (ADS)
Sahoo, Sujit Kumar; Tang, Dongliang; Dang, Cuong
2018-02-01
Large field of view multispectral imaging through scattering medium is a fundamental quest in optics community. It has gained special attention from researchers in recent years for its wide range of potential applications. However, the main bottlenecks of the current imaging systems are the requirements on specific illumination, poor image quality and limited field of view. In this work, we demonstrated a single-shot high-resolution colour-imaging through scattering media using a monochromatic camera. This novel imaging technique is enabled by the spatial, spectral decorrelation property and the optical memory effect of the scattering media. Moreover the use of deconvolution image processing further annihilate above-mentioned drawbacks arise due iterative refocusing, scanning or phase retrieval procedures.
Large Aperture "Photon Bucket" Optical Receiver Performance in High Background Environments
NASA Technical Reports Server (NTRS)
Vilnrotter, Victor A.; Hoppe, D.
2011-01-01
The potential development of large aperture groundbased "photon bucket" optical receivers for deep space communications, with acceptable performance even when pointing close to the sun, is receiving considerable attention. Sunlight scattered by the atmosphere becomes significant at micron wavelengths when pointing to a few degrees from the sun, even with the narrowest bandwidth optical filters. In addition, high quality optical apertures in the 10-30 meter range are costly and difficult to build with accurate surfaces to ensure narrow fields-of-view (FOV). One approach currently under consideration is to polish the aluminum reflector panels of large 34-meter microwave antennas to high reflectance, and accept the relatively large FOV generated by state-of-the-art polished aluminum panels with rms surface accuracies on the order of a few microns, corresponding to several-hundred micro-radian FOV, hence generating centimeter-diameter focused spots at the Cassegrain focus of 34-meter antennas. Assuming pulse-position modulation (PPM) and Poisson-distributed photon-counting detection, a "polished panel" photon-bucket receiver with large FOV will collect hundreds of background photons per PPM slot, along with comparable signal photons due to its large aperture. It is demonstrated that communications performance in terms of PPM symbol-error probability in high-background high-signal environments depends more strongly on signal than on background photons, implying that large increases in background energy can be compensated by a disproportionally small increase in signal energy. This surprising result suggests that large optical apertures with relatively poor surface quality may nevertheless provide acceptable performance for deep-space optical communications, potentially enabling the construction of cost-effective hybrid RF/optical receivers in the future.
Multi-Sensor Fusion of Infrared and Electro-Optic Signals for High Resolution Night Images
Huang, Xiaopeng; Netravali, Ravi; Man, Hong; Lawrence, Victor
2012-01-01
Electro-optic (EO) image sensors exhibit the properties of high resolution and low noise level at daytime, but they do not work in dark environments. Infrared (IR) image sensors exhibit poor resolution and cannot separate objects with similar temperature. Therefore, we propose a novel framework of IR image enhancement based on the information (e.g., edge) from EO images, which improves the resolution of IR images and helps us distinguish objects at night. Our framework superimposing/blending the edges of the EO image onto the corresponding transformed IR image improves their resolution. In this framework, we adopt the theoretical point spread function (PSF) proposed by Hardie et al. for the IR image, which has the modulation transfer function (MTF) of a uniform detector array and the incoherent optical transfer function (OTF) of diffraction-limited optics. In addition, we design an inverse filter for the proposed PSF and use it for the IR image transformation. The framework requires four main steps: (1) inverse filter-based IR image transformation; (2) EO image edge detection; (3) registration; and (4) blending/superimposing of the obtained image pair. Simulation results show both blended and superimposed IR images, and demonstrate that blended IR images have better quality over the superimposed images. Additionally, based on the same steps, simulation result shows a blended IR image of better quality when only the original IR image is available. PMID:23112602
Multi-sensor fusion of infrared and electro-optic signals for high resolution night images.
Huang, Xiaopeng; Netravali, Ravi; Man, Hong; Lawrence, Victor
2012-01-01
Electro-optic (EO) image sensors exhibit the properties of high resolution and low noise level at daytime, but they do not work in dark environments. Infrared (IR) image sensors exhibit poor resolution and cannot separate objects with similar temperature. Therefore, we propose a novel framework of IR image enhancement based on the information (e.g., edge) from EO images, which improves the resolution of IR images and helps us distinguish objects at night. Our framework superimposing/blending the edges of the EO image onto the corresponding transformed IR image improves their resolution. In this framework, we adopt the theoretical point spread function (PSF) proposed by Hardie et al. for the IR image, which has the modulation transfer function (MTF) of a uniform detector array and the incoherent optical transfer function (OTF) of diffraction-limited optics. In addition, we design an inverse filter for the proposed PSF and use it for the IR image transformation. The framework requires four main steps: (1) inverse filter-based IR image transformation; (2) EO image edge detection; (3) registration; and (4) blending/superimposing of the obtained image pair. Simulation results show both blended and superimposed IR images, and demonstrate that blended IR images have better quality over the superimposed images. Additionally, based on the same steps, simulation result shows a blended IR image of better quality when only the original IR image is available.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aseev, P., E-mail: pavel.aseev@isom.upm.es, E-mail: gacevic@isom.upm.es; Gačević, Ž., E-mail: pavel.aseev@isom.upm.es, E-mail: gacevic@isom.upm.es; Calleja, E.
2016-06-20
Series of GaN nanowires (NW) with controlled diameters (160–500 nm) and heights (420–1100 nm) were homoepitaxially grown on three different templates: GaN/Si(111), GaN/AlN/Si(111), and GaN/sapphire(0001). Transmission electron microscopy reveals a strong influence of the NW diameter on dislocation filtering effect, whereas photoluminescence measurements further relate this effect to the GaN NWs near-bandgap emission efficiency. Although the templates' quality has some effects on the GaN NWs optical and structural properties, the NW diameter reduction drives the dislocation filtering effect to the point where a poor GaN template quality becomes negligible. Thus, by a proper optimization of the homoepitaxial GaN NWs growth, the propagationmore » of dislocations into the NWs can be greatly prevented, leading to an exceptional crystal quality and a total dominance of the near-bandgap emission over sub-bandgap, defect-related lines, such as basal stacking faults and so called unknown exciton (UX) emission. In addition, a correlation between the presence of polarity inversion domain boundaries and the UX emission lines around 3.45 eV is established.« less
Automatic retinal interest evaluation system (ARIES).
Yin, Fengshou; Wong, Damon Wing Kee; Yow, Ai Ping; Lee, Beng Hai; Quan, Ying; Zhang, Zhuo; Gopalakrishnan, Kavitha; Li, Ruoying; Liu, Jiang
2014-01-01
In recent years, there has been increasing interest in the use of automatic computer-based systems for the detection of eye diseases such as glaucoma, age-related macular degeneration and diabetic retinopathy. However, in practice, retinal image quality is a big concern as automatic systems without consideration of degraded image quality will likely generate unreliable results. In this paper, an automatic retinal image quality assessment system (ARIES) is introduced to assess both image quality of the whole image and focal regions of interest. ARIES achieves 99.54% accuracy in distinguishing fundus images from other types of images through a retinal image identification step in a dataset of 35342 images. The system employs high level image quality measures (HIQM) to perform image quality assessment, and achieves areas under curve (AUCs) of 0.958 and 0.987 for whole image and optic disk region respectively in a testing dataset of 370 images. ARIES acts as a form of automatic quality control which ensures good quality images are used for processing, and can also be used to alert operators of poor quality images at the time of acquisition.
A simple optical model to estimate suspended particulate matter in Yellow River Estuary.
Qiu, Zhongfeng
2013-11-18
Distribution of the suspended particulate matter (SPM) concentration is a key issue for analyzing the deposition and erosion variety of the estuary and evaluating the material fluxes from river to sea. Satellite remote sensing is a useful tool to investigate the spatial variation of SPM concentration in estuarial zones. However, algorithm developments and validations of the SPM concentrations in Yellow River Estuary (YRE) have been seldom performed before and therefore our knowledge on the quality of retrieval of SPM concentration is poor. In this study, we developed a new simple optical model to estimate SPM concentration in YRE by specifying the optimal wavelength ratios (600-710 nm)/ (530-590 nm) based on observations of 5 cruises during 2004 and 2011. The simple optical model was attentively calibrated and the optimal band ratios were selected for application to multiple sensors, 678/551 for the Moderate Resolution Imaging Spectroradiometer (MODIS), 705/560 for the Medium Resolution Imaging Spectrometer (MERIS) and 680/555 for the Geostationary Ocean Color Imager (GOCI). With the simple optical model, the relative percentage difference and the mean absolute error were 35.4% and 15.6 gm(-3) respectively for MODIS, 42.2% and 16.3 gm(-3) for MERIS, and 34.2% and 14.7 gm(-3) for GOCI, based on an independent validation data set. Our results showed a good precision of estimation for SPM concentration using the new simple optical model, contrasting with the poor estimations derived from existing empirical models. Providing an available atmospheric correction scheme for satellite imagery, our simple model could be used for quantitative monitoring of SPM concentrations in YRE.
NASA Astrophysics Data System (ADS)
Luo, Zhenfei; Wu, Zhiming; Wang, Tao; Xu, Xiangdong; Li, Weizhi; Li, Wei; Jiang, Yadong
2012-09-01
O-poor and O-rich thermochromic vanadium oxide (VOX) nanostructured thin films were prepared by applying reactive direct current magnetron sputtering and post-annealing in oxygen ambient. UV-visible spectrophotometer and spectroscopic ellipsometry were used to investigate the optical properties of films. It was found that, when the O-poor VOX thin film underwent semiconductor-to-metal transition, the values of optical conductivity and extinction coefficient in the visible region increased due to the existence of occupied band-gap states. This noticeable feature, however, was not observed for the O-rich film, which showed a similar optical behavior with the stoichiometric crystalline VO2 films reported in the literatures. Moreover, the O-poor VOX film exhibits consistent variations of transmission values in the visible/near-infrared region when it undergoes semiconductor-to-metal transition.
NASA Astrophysics Data System (ADS)
Wang, Xin; Wang, Cuiluan; Wu, Xia; Zhu, Lingni; Jing, Hongqi; Ma, Xiaoyu; Liu, Suping
2017-02-01
Based on the high-speed development of the fiber laser in recent years, the development of researching 915 nm semiconductor laser as main pumping sources of the fiber laser is at a high speed. Because the beam quality of the laser diode is very poor, the 915 nm laser diode is generally based on optical fiber coupling module to output the laser. Using the beam-shaping and fiber-coupling technology to improve the quality of output beam light, we present a kind of high-power and high-brightness semiconductor laser module, which can output 13.22 W through the optical fiber. Based on 915 nm GaAs semiconductor laser diode which has output power of 13.91 W, we describe a thoroughly detailed procedure for reshaping the beam output from the semiconductor laser diode and coupling the beam into the optical fiber of which the core diameter is 105 μm and the numerical aperture is 0.18. We get 13.22 W from the output fiber of the module at 14.5 A, the coupling efficiency of the whole module is 95.03% and the brightness is 1.5 MW/cm2 -str. The output power of the single chip semiconductor laser module achieves the advanced level in the domestic use.
Li, Dongming; Sun, Changming; Yang, Jinhua; Liu, Huan; Peng, Jiaqi; Zhang, Lijuan
2017-04-06
An adaptive optics (AO) system provides real-time compensation for atmospheric turbulence. However, an AO image is usually of poor contrast because of the nature of the imaging process, meaning that the image contains information coming from both out-of-focus and in-focus planes of the object, which also brings about a loss in quality. In this paper, we present a robust multi-frame adaptive optics image restoration algorithm via maximum likelihood estimation. Our proposed algorithm uses a maximum likelihood method with image regularization as the basic principle, and constructs the joint log likelihood function for multi-frame AO images based on a Poisson distribution model. To begin with, a frame selection method based on image variance is applied to the observed multi-frame AO images to select images with better quality to improve the convergence of a blind deconvolution algorithm. Then, by combining the imaging conditions and the AO system properties, a point spread function estimation model is built. Finally, we develop our iterative solutions for AO image restoration addressing the joint deconvolution issue. We conduct a number of experiments to evaluate the performances of our proposed algorithm. Experimental results show that our algorithm produces accurate AO image restoration results and outperforms the current state-of-the-art blind deconvolution methods.
Li, Dongming; Sun, Changming; Yang, Jinhua; Liu, Huan; Peng, Jiaqi; Zhang, Lijuan
2017-01-01
An adaptive optics (AO) system provides real-time compensation for atmospheric turbulence. However, an AO image is usually of poor contrast because of the nature of the imaging process, meaning that the image contains information coming from both out-of-focus and in-focus planes of the object, which also brings about a loss in quality. In this paper, we present a robust multi-frame adaptive optics image restoration algorithm via maximum likelihood estimation. Our proposed algorithm uses a maximum likelihood method with image regularization as the basic principle, and constructs the joint log likelihood function for multi-frame AO images based on a Poisson distribution model. To begin with, a frame selection method based on image variance is applied to the observed multi-frame AO images to select images with better quality to improve the convergence of a blind deconvolution algorithm. Then, by combining the imaging conditions and the AO system properties, a point spread function estimation model is built. Finally, we develop our iterative solutions for AO image restoration addressing the joint deconvolution issue. We conduct a number of experiments to evaluate the performances of our proposed algorithm. Experimental results show that our algorithm produces accurate AO image restoration results and outperforms the current state-of-the-art blind deconvolution methods. PMID:28383503
Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna
2016-01-01
In this paper, the influence of the rotating polarization-preserved optical feedback on the chaos synchronization of a vertical-cavity surface-emitting laser (VCSEL) is investigated experimentally. Two VCSELs' polarization modes (XP) and (YP) are gradually rotated and re-injected back into the VCSEL. The anti-phase dynamics synchronization of the two polarization modes is evaluated using the cross-correlation function. For a fixed optical feedback, a clear relationship is found between the cross-correlation coefficient and the polarization angle θp. It is shown that high-quality anti-phase polarization-resolved chaos synchronization is achieved at higher values of θp. The maximum value of the cross-correlation coefficient achieved is -0.99 with a zero time delay over a wide range of θp beyond 65° with a poor synchronization dynamic at θp less than 65°. Furthermore, it is observed that the antiphase irregular oscillation of the XP and YP modes changes with θp. VCSEL under the rotating polarization optical feedback can be a good candidate as a chaotic synchronization source for a secure communication system.
In vivo imaging in the oral cavity by endoscopic optical coherence tomography.
Walther, Julia; Schnabel, Christian; Tetschke, Florian; Rosenauer, Tobias; Golde, Jonas; Ebert, Nadja; Baumann, Michael; Hannig, Christian; Koch, Edmund
2018-03-01
The common way to diagnose hard and soft tissue irregularities in the oral cavity is initially the visual inspection by an experienced dentist followed by further medical examinations, such as radiological imaging and/or histopathological investigation. For the diagnosis of oral hard and soft tissues, the detection of early transformations is mostly hampered by poor visual access, low specificity of the diagnosis techniques, and/or limited feasibility of frequent screenings. Therefore, optical noninvasive diagnosis of oral tissue is promising to improve the accuracy of oral screening. Considering this demand, a rigid handheld endoscopic scanner was developed for optical coherence tomography (OCT). The novelty is the usage of a commercially near-infrared endoscope with fitting optics in combination with an established spectral-domain OCT system of our workgroup. By reaching a high spatial resolution, in vivo images of anterior and especially posterior dental and mucosal tissues were obtained from the oral cavity of two volunteers. The convincing image quality of the endoscopic OCT device is particularly obvious for the imaging of different regions of the human soft palate with highly scattering fibrous layer and capillary network within the lamina propria. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).
The Recovery of Optical Quality after Laser Vision Correction
Jung, Hyeong-Gi
2013-01-01
Purpose To evaluate the optical quality after laser in situ keratomileusis (LASIK) or serial photorefractive keratectomy (PRK) using a double-pass system and to follow the recovery of optical quality after laser vision correction. Methods This study measured the visual acuity, manifest refraction and optical quality before and one day, one week, one month, and three months after laser vision correction. Optical quality parameters including the modulation transfer function, Strehl ratio and intraocular scattering were evaluated with a double-pass system. Results This study included 51 eyes that underwent LASIK and 57 that underwent PRK. The optical quality three months post-surgery did not differ significantly between these laser vision correction techniques. Furthermore, the preoperative and postoperative optical quality did not differ significantly in either group. Optical quality recovered within one week after LASIK but took between one and three months to recover after PRK. The optical quality of patients in the PRK group seemed to recover slightly more slowly than their uncorrected distance visual acuity. Conclusions Optical quality recovers to the preoperative level after laser vision correction, so laser vision correction is efficacious for correcting myopia. The double-pass system is a useful tool for clinical assessment of optical quality. PMID:23908570
Bergamaschi, Brian A.; Kalve, Erica; Guenther, Larry; Mendez, Gregory O.; Belitz, Kenneth
2005-01-01
The ability to rapidly, reliably, and inexpensively characterize sources of dissolved organic material (DOM) in watersheds would allow water management agencies to more quickly identify problems in water sources, and to more efficiently allocate water resources by, for example, permitting real-time identification of high-quality water suitable for ground-water recharge, or poor-quality water in need of mitigation. This study examined the feasibility of using easily measurable intrinsic optical properties' absorbance and fluorescence spectra, as quantitative indicators of DOM sources and, thus, a predictor of water quality. The study focused on the Santa Ana River Basin, in southern California, USA, which comprises an area of dense urban development and an area of intense dairy production. Base flow in the Santa Ana Basin is primarily tertiary treated wastewater discharge. Available hydrologic data indicate that urban and agricultural runoff degrades water quality during storm events by introducing pathogens, nutrients, and other contaminants, including significant amounts of DOM. These conditions provide the basis for evaluating the use of DOM optical properties as a tracer of DOM from different sources. Sample spectra representing four principal DOM sources were identified among all samples collected in 1999 on the basis of basin hydrology, and the distribution of spectral variability within all the sample data. A linear mixing model provided quantitative estimates of relative endmember contribution to sample spectra for monthly, storm, and diurnal samples. The spectral properties of the four sources (endmembers), Pristine Water, Wastewater, Urban Water, and Dairy Water, accounted for 94 percent of the variability in optical properties observed in the study, suggesting that all important DOM sources were represented. The scale and distribution of the residual spectra, that not explained by the endmembers, suggested that the endmember spectra selected did not adequately represent Urban Water base flow. However, model assignments of sources generally agreed well with those expected, based on sampling location and hydrology. The results suggest that with a fuller characterization of the endmember spectra, analysis of optical properties will provide rapid quantitative estimates of the relative contribution of DOM sources in the Santa Ana Basin.
Vandermeer, G; Chamy, Y; Pisella, P-J
2018-02-01
Dry eye is defined by a tear film instability resulting in variable but systematic fluctuations in quality of vision. Variability in optical quality can be demonstrated using a double pass aberrometer such as the Optical Quality Analyzing System, Visiometrics (OQAS). The goal of this work is to compare fluctuations in objective quality of vision measured by OQAS between treatment with normal saline eye drops and treatment with carmellose 0.5% and hyaluronic acid 0.1% (Optive Fusion [OF], Allergan) in patients with moderate dry eye syndrome. Optical quality was measured by evaluating the variations in the Optical Scattering Index (OSI) over 20seconds using the OQAS. Inclusion criteria were dry eye syndrome with an ocular surface disease index (OSDI) score >23 treated only with artificial tears. The patients were their own controls: OF in one eye and normal saline in the fellow eye. The choice of the subject eye and control eye was determined in a randomized fashion. OSI variations were measured in each eye before instillation, 5minutes and 2hours after instillation. The primary endpoint was OSI fluctuation over 20seconds of measurement. Secondary endpoints were the number of blinks and patient preference (preferred eye). Preliminary results were obtained on 19 patients. Average OSDI score was 36.8. Visual acuity was 10/10 with no significant difference between the two eyes. Prior to instillation, there was no significant difference between "normal saline" and "OF" eyes in terms of OSI, OSI variability or number of blinks. In the normal saline eye, there were no significant variations in mean OSI, OSI variability, OSI slope, or number of blinks. However, in the "OF" eye, there was a significant variation between initial and 2-hour OSI variability (0.363 versus 0.204, P<0.05), the average slope of OSI (0.04 versus 0.01, P<0.05) and the number of blinks (4.2 versus 2.8, P<0.05). Among the patients, 65% preferred the OF eye, 24% did not have a preference, and 11% preferred the normal saline eye. Objective quality of vision measured by OQAS is an interesting parameter for evaluating the effectiveness of a lacrimal substitute. The purpose of artificial tears is, among other things, to provide comfort and a reduction of dry eye symptoms such as poor quality of vision. This study demonstrates that 0.5% carmellose and 0.1% hyaluronic acid allowed better stabilization of the tear film and thus a significant improvement in the quality of vision compared to normal saline. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Vandermeer, G; Chamy, Y; Pisella, P-J
2018-03-01
Dry eye is defined by a tear film instability resulting in variable but systematic fluctuations in the quality of vision. Variability in optical quality can be demonstrated using a double pass aberrometer such as the OQAS (Optical Quality Analyzing System, Visiometrics). The goal of this work is to compare fluctuations in objective quality of vision measured by OQAS between treatment with normal saline eye drops and treatment with carmellose 0.5% and hyaluronic acid 0.1% (Optive Fusion [OF], Allergan) in patients with moderate dry eye syndrome. Optical quality was measured by evaluating the variations in the Optical Scattering Index (OSI) over 20seconds using the OQAS. Inclusion criteria were dry eye syndrome with an Ocular Surface Disease Index (OSDI) score>23 treated only with artificial tears. The patients were their own controls: OF in one eye and normal saline in the fellow eye. The choice of the subject eye and control eye was determined in a randomized fashion. OSI variations were measured in each eye before instillation, 5minutes and 2hours after instillation. The primary endpoint was OSI fluctuation over 20seconds of measurement. Secondary endpoints were the number of blinks and patient's preference (preferred eye). Preliminary results were obtained on 19 patients. Average OSDI score was 36.8. Visual acuity was 10/10 with no significant difference between the two eyes. Prior to instillation, there was no significant difference between "normal saline" and "OF" eyes in terms of OSI, OSI variability or number of blinks. In the normal saline eye, there was no significant variation in mean OSI, OSI variability, OSI slope, or number of blinks. However, in the "OF" eye, there was a significant variation between initial and 2-hour OSI variability (0.363 versus 0.204; P<0.05), the average slope of OSI (0.04 versus 0.01; P<0.05) and the number of blinks (4.2 versus 2.8; P<0.05). Sixty-five percent of patients preferred the OF eye, 24% did not have a preference, and 11% preferred the normal saline eye. Objective quality of vision measured by OQAS is an interesting parameter for evaluating the effectiveness of a lacrimal substitute. The purpose of artificial tears is, among other things, to provide comfort and a reduction of dry eye symptoms such as poor quality of vision. This study demonstrates that 0.5% carmellose and 0.1% hyaluronic acid allowed better stabilization of the tear film and thus a significant improvement in the quality of vision compared to normal saline. Copyright © 2018 Elsevier Masson SAS. All rights reserved.
Ultrasonic grinding of optical materials
NASA Astrophysics Data System (ADS)
Cahill, Michael; Bechtold, Michael; Fess, Edward; Stephan, Thomas; Bechtold, Rob
2017-10-01
Hard ceramic optical materials such as sapphire, ALON, Spinel, PCA, or Silicon Carbide can present a significant challenge in manufacturing precision optical components due to their tough mechanical properties. These are also the same mechanical properties that make them desirable materials when used in harsh environments. Slow processing speeds, premature tool wear, and poor surface quality are common results of the tough mechanical properties of these materials. Often, as a preparatory stage for polishing, the finish of the ground surface greatly influences the polishing process and the resulting finished product. To overcome these challenges, OptiPro Systems has developed an ultrasonic assisted grinding technology, OptiSonic, which has been designed for the precision optics and ceramics industry. OptiSonic utilizes a custom tool holder designed to produce oscillations, in microns of amplitude, in line with the rotating spindle. A software package, IntelliSonic, is integral to the function of this platform. IntelliSonic can automatically characterize tooling during setup to identify and select the ideal resonant peak which to operate at. Then, while grinding, IntelliSonic continuously adjusts the output frequency for optimal grinding efficiency while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more precise surface. Utilizing a variety of instruments, tests have proven to show a reduction in force between tool and part by up to 50%, while increasing the surface quality and reducing tool wear. This paper will present the challenges associated with these materials and solutions created to overcome them.
From optics to attention: visual perception in barn owls.
Harmening, Wolf M; Wagner, Hermann
2011-11-01
Barn owls are nocturnal predators which have evolved specific sensory and morphological adaptations to a life in dim light. Here, some of the most fundamental properties of spatial vision in barn owls are reviewed. The eye with its tubular shape is rigidly integrated in the skull so that eye movements are very much restricted. The eyes are oriented frontally, allowing for a large binocular overlap. Accommodation, but not pupil dilation, is coupled between the two eyes. The retina is rod dominated and lacks a visible fovea. Retinal ganglion cells form a marked region of highest density that extends to a horizontally oriented visual streak. Behavioural visual acuity and contrast sensitivity are poor, although the optical quality of the ocular media is excellent. A low f-number allows high image quality at low light levels. Vernier acuity was found to be a hyperacute percept. Owls have global stereopsis with hyperacute stereo acuity thresholds. Neurons of the visual Wulst are sensitive to binocular disparities. Orientation based saliency was demonstrated in a visual-search experiment, and higher cognitive abilities were shown when the owl's were able to use illusory contours for object discrimination.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna
2016-01-15
In this paper, the influence of the rotating polarization-preserved optical feedback on the chaos synchronization of a vertical-cavity surface-emitting laser (VCSEL) is investigated experimentally. Two VCSELs' polarization modes (XP) and (YP) are gradually rotated and re-injected back into the VCSEL. The anti-phase dynamics synchronization of the two polarization modes is evaluated using the cross-correlation function. For a fixed optical feedback, a clear relationship is found between the cross-correlation coefficient and the polarization angle θ{sub p}. It is shown that high-quality anti-phase polarization-resolved chaos synchronization is achieved at higher values of θ{sub p}. The maximum value of the cross-correlation coefficient achievedmore » is −0.99 with a zero time delay over a wide range of θ{sub p} beyond 65° with a poor synchronization dynamic at θ{sub p} less than 65°. Furthermore, it is observed that the antiphase irregular oscillation of the XP and YP modes changes with θ{sub p}. VCSEL under the rotating polarization optical feedback can be a good candidate as a chaotic synchronization source for a secure communication system.« less
NASA Astrophysics Data System (ADS)
Hooper, Abigail R.; Boffa, Christopher C.; Sarkas, Harry W.; Cureton, Kevin
2015-08-01
When building an optical system, optical fabricators and designers meticulously choose the glass types for their application knowing that each one will have different chemical, thermal and mechanical properties. As the requirements for new optical systems have grown more demanding, the range of available glass types has vastly expanded and the specifications on the produced products have grown tighter. In an attempt to simplify processes and streamline consumable purchases, optical polishing houses often rely on one polishing slurry to manage these vast array of glass types. An unforeseen consequence of these practices can be a reduction in productivity by reduced removal rate, poor yields and frequent rework all translating into higher costs and reduced profitability. In this paper, the authors will examine the impact slurry pH has on glass types of different compositions and chemical, thermal and mechanical properties when using a double-sided polishing process. Experiments will use material removal rate, surface quality, and surface figure to provide insight into improving process control for differing glass types. Further guidance will be provided on how simple on-site monitoring and adjustment can deliver improved profitability on challenging substrates.
Glaucoma management in patients with osteo-odonto-keratoprosthesis (OOKP): the Singapore OOKP Study.
Kumar, Rajesh S; Tan, Donald T H; Por, Yong-Ming; Oen, Francis T; Hoh, Sek-Tien; Parthasarathy, Anand; Aung, Tin
2009-01-01
To report diagnostic modalities and treatment options for glaucoma in eyes with osteo-odonto keratoprosthesis (OOKP). Eyes that underwent OOKP were evaluated for glaucoma at the time of the first postoperative visit, then at 1 and 3 months after the procedure, and thereafter every 6 months. All eyes underwent stereo-biomicroscopic optic nerve head (ONH) assessment, kinetic (Goldmann perimetry) and automated static visual field testing, ONH photography, Heidelberg retina tomograph, scanning laser polarimetery (GDx), and optical coherence tomography. Treatment of glaucoma was also reviewed. Average follow-up period was 19.1 (range: 5 to 31) months. Of the 15 eyes that underwent OOKP, 5 eyes had preexisting glaucoma. None of the other 10 eyes developed glaucoma after OOKP. ONH photography and visual field testing were the most reliable methods to assess status of the disease, whereas Heidelberg retina tomograph and optical coherence tomography could be performed with reasonable reproducibility and quality; GDx imaging was poor. All patients with glaucoma were treated with oral acetazolamide 500 mg twice a day. Transscleral cyclophotocoagulation was performed in 3 eyes at stage 2 of OOKP surgery. Progression of glaucoma was noted in 2 eyes on the basis of optic disc photographs and automated perimetry. Visual field testing and optic disc assessment with optic disc photographs seem to be effective methods to monitor eyes with OOKP for glaucoma. Treatment strategies include oral medications to lower intraocular pressure and cyclophotocoagulation.
Zhang, Pan; Lou, Peian; Chang, Guiqiu; Chen, Peipei; Zhang, Lei; Li, Ting; Qiao, Cheng
2016-04-05
Poor sleep quality and depression negatively impact the health-related quality of life of patients with type 2 diabetes, but the combined effect of the two factors is unknown. This study aimed to assess the interactive effects of poor sleep quality and depression on the quality of life in patients with type 2 diabetes. Patients with type 2 diabetes (n = 944) completed the Diabetes Specificity Quality of Life scale (DSQL) and questionnaires on sleep quality and depression. The products of poor sleep quality and depression were added to the logistic regression model to evaluate their multiplicative interactions, which were expressed as the relative excess risk of interaction (RERI), the attributable proportion (AP) of interaction, and the synergy index (S). Poor sleep quality and depressive symptoms both increased DSQL scores. The co-presence of poor sleep quality and depressive symptoms significantly reduced DSQL scores by a factor of 3.96 on biological interaction measures. The relative excess risk of interaction was 1.08. The combined effect of poor sleep quality and depressive symptoms was observed only in women. Patients with both depressive symptoms and poor sleep quality are at an increased risk of reduction in diabetes-related quality of life, and this risk is particularly high for women due to the interaction effect. Clinicians should screen for and treat sleep difficulties and depressive symptoms in patients with type 2 diabetes.
Pandey, Shweta; Bajaj, Bhupender Kumar; Wadhwa, Ankur; Anand, Kuljeet Singh
2016-09-01
Poor sleep quality contributes to the inferior quality of life of patients with Parkinson's disease (PD) despite appropriate treatment of motor symptoms. The literature about the impact of sleep quality on quality of life of patients with PD is as yet sparse. One hundred patients of PD diagnosed as per UK Brain Bank criteria were assessed for severity and stage of PD using UPDRS and modified Hoehn &Yahr scales. The quality of sleep was assessed by Pittsburgh Sleep Quality Index and excessive daytime somnolence (EDS) was evaluated using Epworth Sleepiness Scale. Parkinson's Disease Questionnaire -39 (PDQ-39) was used to determine quality of life of the patients. Comorbid depression and anxiety were assessed using Inventory of Depressive Symptoms-Self Rated and Hamilton Anxiety Rating Scale. Pearson's correlation and multiple linear regressions were used to analyze relation of sleep quality with quality of life of patients. Fifty patients had poor sleep quality. EDS was present in only 9 patients. Co-morbid depression and anxiety were present in 52 and 34 patients respectively. While the motor severity assessed by UPDRS-III was observed to adversely affect quality of life, it did not negatively impact quality of sleep. Higher score on UPDRS-total and UPDRS IV suggesting advanced disease correlated with poor sleep quality. Depression and anxiety were significantly more frequent in patients with poor sleep quality (p<0.01). Patients with poor sleep quality had worse quality of life (r=0.338, p<0.05). Depression and anxiety were also observed to have significant negative impact on quality of life of PD patients (p<0.01). Poor sleep quality was not found to be an independent predictor of quality of life using multiple linear regression analysis. Poor sleep quality along with comorbid depression, anxiety and advanced stage of disease is associated with poor quality of life. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Sanginés, R.; Abundiz-Cisneros, N.; Hernández Utrera, O.; Diliegros-Godines, C.; Machorro-Mejía, R.
2018-03-01
In this work, we present a thorough study on the relation between the plasma emission and the change of the silicon nitride thin films refractive index. Thin films were grown by reactive magnetron direct current sputtering technique and deposited onto silicon wafers at different fluxes of Ar and N2 and at different working pressures. This procedure, at certain deposition parameters, produced poor quality films, i.e. films with refractive index other than pure Si3N4 films. The emission of the plasma was interrogated in real time by means of optical emission spectroscopy (OES) observing at the vicinity of the trget location. In addition, optical properties of the films were measured by in situ ellipsometric-spectroscopy and then correlated with OES observations. Changes in the film refractive index could be deduced from changes in plasma emission applying a principal component analysis.
Odontological light-emitting diode light-curing unit beam quality.
de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira
2015-05-01
The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF = 1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF = 0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.
Odontological light-emitting diode light-curing unit beam quality
NASA Astrophysics Data System (ADS)
de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira
2015-05-01
The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF=1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF=0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.
Effect of laser incidence angle on cut quality of 4 mm thick stainless steel sheet using fiber laser
NASA Astrophysics Data System (ADS)
Mullick, Suvradip; Agrawal, Arpit Kumar; Nath, Ashish Kumar
2016-07-01
Fiber laser has potential to outperform the more traditionally used CO2 lasers in sheet metal cutting applications due to its higher efficiency, better beam quality, reliability and ease of beam delivery through optical fiber. It has been however, reported that the higher focusability and shorter wavelength are advantageous for cutting thin metal sheets up to about 2 mm only. Better focasability results in narrower kerf-width, which leads to an earlier flow separation in the flow of assist gas within the kerf, resulting in uncontrolled material removal and poor cut quality. However, the advarse effect of tight focusability can be taken care by shifting the focal point position towards the bottom surface of work-piece, which results in a wider kerf size. This results in a more stable flow within the kerf for a longer depth, which improves the cut quality. It has also been reported that fiber laser has an unfavourable angle of incidence during cutting of thick sections, resulting in poor absorption at the metal surface. Therefore, the effect of laser incidence angle, along with other process parameters, viz. cutting speed and assist gas pressure on the cut quality of 4 mm thick steel sheet has been investigated. The change in laser incidence angle has been incorporated by inclining the beam towards and away from the cut front, and the quality factors are taken as the ratio of kerf width and the striation depth. Besides the absorption of laser radiation, beam inclination is also expected to influence the gas flow characteristics inside the kerf, shear force phenomena on the molten pool, laser beam coupling and laser power distribution at the inclined cut surface. Design of experiment has been used by implementing response surface methodology (RSM) to study the parametric dependence of cut quality, as well as to find out the optimum cut quality. An improvement in quality has been observed for both the inclination due to the combined effect of multiple phenomena.
Conformation of ionizable poly Para phenylene ethynylene in dilute solutions
Wijesinghe, Sidath; Maskey, Sabina; Perahia, Dvora; ...
2015-11-03
The conformation of dinonyl poly para phenylene ethynylenes (PPEs) with carboxylate side chains, equilibrated in solvents of different quality is studied using molecular dynamics simulations. PPEs are of interest because of their tunable electro-optical properties, chemical diversity, and functionality which are essential in wide range of applications. The polymer conformation determines the conjugation length and their assembly mode and affects electro-optical properties which are critical in their current and potential uses. The current study investigates the effect of carboxylate fraction on PPEs side chains on the conformation of chains in the dilute limit, in solvents of different quality. The dinonylmore » PPE chains are modeled atomistically, where the solvents are modeled both implicitly and explicitly. Dinonyl PPEs maintained a stretched out conformation up to a carboxylate fraction f of 0.7 in all solvents studied. The nonyl side chains are extended and oriented away from the PPE backbone in toluene and in implicit good solvent whereas in water and implicit poor solvent, the nonyl side chains are collapsed towards the PPE backbone. Thus, rotation around the aromatic ring is fast and no long range correlations are seen within the backbone.« less
Conformation of ionizable poly Para phenylene ethynylene in dilute solutions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wijesinghe, Sidath; Maskey, Sabina; Perahia, Dvora
The conformation of dinonyl poly para phenylene ethynylenes (PPEs) with carboxylate side chains, equilibrated in solvents of different quality is studied using molecular dynamics simulations. PPEs are of interest because of their tunable electro-optical properties, chemical diversity, and functionality which are essential in wide range of applications. The polymer conformation determines the conjugation length and their assembly mode and affects electro-optical properties which are critical in their current and potential uses. The current study investigates the effect of carboxylate fraction on PPEs side chains on the conformation of chains in the dilute limit, in solvents of different quality. The dinonylmore » PPE chains are modeled atomistically, where the solvents are modeled both implicitly and explicitly. Dinonyl PPEs maintained a stretched out conformation up to a carboxylate fraction f of 0.7 in all solvents studied. The nonyl side chains are extended and oriented away from the PPE backbone in toluene and in implicit good solvent whereas in water and implicit poor solvent, the nonyl side chains are collapsed towards the PPE backbone. Thus, rotation around the aromatic ring is fast and no long range correlations are seen within the backbone.« less
Labhart, T; Petzold, J; Helbling, H
2001-07-01
Many insects exploit the polarization pattern of the sky for compass orientation in navigation or cruising-course control. Polarization-sensitive neurones (POL1-neurones) in the polarization vision pathway of the cricket visual system have wide visual fields of approximately 60 degrees diameter, i.e. these neurones integrate information over a large area of the sky. This results from two different mechanisms. (i) Optical integration; polarization vision is mediated by a group of specialized ommatidia at the dorsal rim of the eye. These ommatidia lack screening pigment, contain a wide rhabdom and have poor lens optics. As a result, the angular sensitivity of the polarization-sensitive photoreceptors is very wide (median approximately 20 degrees ). (ii) Neural integration; each POL1-neurone receives input from a large number of dorsal rim photoreceptors with diverging optical axes. Spatial integration in POL1-neurones acts as a spatial low-pass filter. It improves the quality of the celestial polarization signal by filtering out cloud-induced local disturbances in the polarization pattern and increases sensitivity.
Automated assembly of camera modules using active alignment with up to six degrees of freedom
NASA Astrophysics Data System (ADS)
Bräuniger, K.; Stickler, D.; Winters, D.; Volmer, C.; Jahn, M.; Krey, S.
2014-03-01
With the upcoming Ultra High Definition (UHD) cameras, the accurate alignment of optical systems with respect to the UHD image sensor becomes increasingly important. Even with a perfect objective lens, the image quality will deteriorate when it is poorly aligned to the sensor. For evaluating the imaging quality the Modulation Transfer Function (MTF) is used as the most accepted test. In the first part it is described how the alignment errors that lead to a low imaging quality can be measured. Collimators with crosshair at defined field positions or a test chart are used as object generators for infinite-finite or respectively finite-finite conjugation. The process how to align the image sensor accurately to the optical system will be described. The focus position, shift, tilt and rotation of the image sensor are automatically corrected to obtain an optimized MTF for all field positions including the center. The software algorithm to grab images, calculate the MTF and adjust the image sensor in six degrees of freedom within less than 30 seconds per UHD camera module is described. The resulting accuracy of the image sensor rotation is better than 2 arcmin and the accuracy position alignment in x,y,z is better 2 μm. Finally, the process of gluing and UV-curing is described and how it is managed in the integrated process.
Estimated Under-Five Deaths Associated with Poor-Quality Antimalarials in Sub-Saharan Africa
Renschler, John P.; Walters, Kelsey M.; Newton, Paul N.; Laxminarayan, Ramanan
2015-01-01
Many antimalarials sold in sub-Saharan Africa are poor-quality (falsified, substandard, or degraded), and the burden of disease caused by this problem is inadequately quantified. In this article, we estimate the number of under-five deaths caused by ineffective treatment of malaria associated with consumption of poor-quality antimalarials in 39 sub-Saharan countries. Using Latin hypercube sampling our estimates were calculated as the product of the number of private sector antimalarials consumed by malaria-positive children in 2013; the proportion of private sector antimalarials consumed that were of poor-quality; and the case fatality rate (CFR) of under-five malaria-positive children who did not receive appropriate treatment. An estimated 122,350 (interquartile range [IQR]: 91,577–154,736) under-five malaria deaths were associated with consumption of poor-quality antimalarials, representing 3.75% (IQR: 2.81–4.75%) of all under-five deaths in our sample of 39 countries. There is considerable uncertainty surrounding our results because of gaps in data on case fatality rates and prevalence of poor-quality antimalarials. Our analysis highlights the need for further investigation into the distribution of poor-quality antimalarials and the need for stronger surveillance and regulatory efforts to prevent the sale of poor-quality antimalarials. PMID:25897068
Matsuda, Risa; Kohno, Takashi; Kohsaka, Shun; Fukuoka, Ryoma; Maekawa, Yuichiro; Sano, Motoaki; Takatsuki, Seiji; Fukuda, Keiichi
2017-02-01
Poor sleep quality contributes to the development of various cardiovascular conditions. However, its real-world prevalence among cardiovascular inpatients and association with psychological disturbance is unknown. This study aimed to assess the prevalence of poor sleep quality and its association with depression and anxiety in cardiovascular patients, and explored whether sex and cardiovascular comorbidities modified these associations. A total of 1071 patients hospitalized for a broad spectrum of cardiovascular diseases at a single university hospital were assessed (790 men, mean age 64±14years). We assessed sleep quality during their index hospitalization period using the Pittsburgh Sleep Quality Index (PSQI); poor sleep quality was defined as PSQI>5. Depression and anxiety were assessed with the Hospital Anxiety and Depression Scale (HADS). The median PSQI score was 5.0 [3.0-7.0], and 461 inpatients (43%) had poor sleep quality. Multivariate regression analysis adjusting for patient background, medical risk factors, and laboratory data revealed that poor sleep quality was associated with higher HADS subscores for depression (HADS-depression; odds ratio [OR]: 1.09, 95% confidence interval [CI]: 1.03-1.15) and anxiety (HADS-anxiety; OR: 1.17, 95% CI: 1.11-1.24). Poor sleep quality was associated with markedly higher HADS-depression among women than men (p value for interaction: 0.008). The association between poor sleep quality and HADS-anxiety was more significant among patients without coronary artery diseases (p value for interaction: 0.017). Poor sleep quality was highly prevalent and associated with depression and anxiety in cardiovascular patients. These associations may be modified by sex and the presence of coronary artery diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Walker, Constance E.; M, Pompea, Stephen
2018-01-01
Poor quality lighting impedes astronomy research and our right to see a starry night sky. It creates safety issues, affects human circadian sensitivities, disrupts ecosystems, and wastes billions of dollars/year in energy consumption. It also leads to excess carbon emissions. How do you change the mindset of society that is used to turning night into day? You educate the next generation on quality lighting.As an outcome of the International Year of Light 2015, the National Optical Astronomy Observatory’s Education and Public Outreach group has produced a Quality Lighting Teaching (QLT) Kit. The kits are designed around problem-based learning scenarios. The kit’s six activities allow students to address real lighting problems that relate to wildlife, sky glow, aging eyes, energy consumption, safety, and light trespass. The activities are optimized for 11-14 year olds but can be expanded to younger and older. All materials are in both English and Spanish. Most of the activities can be done within in a few minutes during class or afterschool and as stations or as stand-alones. Everything you need for the six activities is included in the kit. Tutorial videos on how to do the activities can be found at www.noao.edu/education/qltkit.php. Ninety-two out of one hundred kits have been distributed in thirty-two countries through SPIE (the International Society for Optical Engineering), CIE (the International Commission on Illuminations), OSA (the Optical Society), IDA (the International Dark Sky Association), and the IAU OAD–Office of Astronomy Development. Successful feedback is promoting a choice between commercializing the kit or gaining further grants to build more kits. A plan is being considered to distribute kits to observatories around the world, hence helping to reduce the effects of one of the three threats to observational astronomy through awareness and action.
Herring, Matthew P; Monroe, Derek C; Kline, Christopher E; O'Connor, Patrick J; MacDonncha, Ciaran
2018-03-05
Physical activity (PA) can improve sleep quality, low energy, and fatigue. Though poor sleep quality may induce feelings of low energy and fatigue, the potential moderating effect of sleep quality on associations between PA and feelings of energy and fatigue among adolescents is unknown. Thus, this study examined the moderating effect of sleep quality on associations between PA frequency and feelings of energy and fatigue among adolescents in Ireland. Adolescents (N = 481; 281 males, 200 females) aged 15.1 ± 1.7 years self-reported PA frequency, feelings of energy and fatigue, and sleep quality (September to December 2015). Two-way ANCOVAs examined variation in feelings of energy and fatigue according to the interaction of PA and sleep quality. Standardized mean difference (d) quantified the magnitude of differences. Poor sleepers with low PA reported greater feelings of fatigue compared to normal sleepers with low PA (d = 1.02; 95% CI 0.60, 1.44), and poor sleepers with moderate PA reported greater feelings of fatigue compared to normal sleepers with moderate PA (d = 0.50; 0.17, 0.82). Poor sleepers with low PA reported greater feelings of fatigue compared to both poor sleepers with moderate PA (d = 0.44; 0.05, 0.83) and poor sleepers with high PA (d = 0.87; 0.46, 1.28). Poor sleepers with moderate PA reported greater feelings of fatigue compared to poor sleepers with high PA (d = 0.52; 0.14, 0.91). Poor sleep did not moderate the association between PA and feelings of energy. Sleep quality moderates the association between PA frequency and feelings of fatigue. Fatigue symptoms improve as PA frequency increases among adolescents with poor sleep quality.
Adaptive optics retinal imaging in the living mouse eye
Geng, Ying; Dubra, Alfredo; Yin, Lu; Merigan, William H.; Sharma, Robin; Libby, Richard T.; Williams, David R.
2012-01-01
Correction of the eye’s monochromatic aberrations using adaptive optics (AO) can improve the resolution of in vivo mouse retinal images [Biss et al., Opt. Lett. 32(6), 659 (2007) and Alt et al., Proc. SPIE 7550, 755019 (2010)], but previous attempts have been limited by poor spot quality in the Shack-Hartmann wavefront sensor (SHWS). Recent advances in mouse eye wavefront sensing using an adjustable focus beacon with an annular beam profile have improved the wavefront sensor spot quality [Geng et al., Biomed. Opt. Express 2(4), 717 (2011)], and we have incorporated them into a fluorescence adaptive optics scanning laser ophthalmoscope (AOSLO). The performance of the instrument was tested on the living mouse eye, and images of multiple retinal structures, including the photoreceptor mosaic, nerve fiber bundles, fine capillaries and fluorescently labeled ganglion cells were obtained. The in vivo transverse and axial resolutions of the fluorescence channel of the AOSLO were estimated from the full width half maximum (FWHM) of the line and point spread functions (LSF and PSF), and were found to be better than 0.79 μm ± 0.03 μm (STD)(45% wider than the diffraction limit) and 10.8 μm ± 0.7 μm (STD)(two times the diffraction limit), respectively. The axial positional accuracy was estimated to be 0.36 μm. This resolution and positional accuracy has allowed us to classify many ganglion cell types, such as bistratified ganglion cells, in vivo. PMID:22574260
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pierson, W.J. Jr.
1990-08-15
Wind reports by data buoys are used to demonstrate that these reports have in the past provided useful values for the synoptic scale winds and that at present these reports provide very reliable values for the synoptic scale winds. Past studies of wind reports by ships have revealed that the data are of poor quality, but the causes for this poor quality are not identified. Examples of the poor quality of wind data from ships are obtained by comparing ship reports with buoy reports and comparing reports of different kinds of ships with each other. These comparisons identify many differentmore » reasons for the poor quality of wind data from ships. Suggestions are made for improving the quality of ship data. The consequences of the poor quality of ship winds are described in terms of the effects on weather and wave forecasts. The implications for remotely sensed winds are discussed.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peterson, Ruth C.; Kurucz, Robert L.; Ayres, Thomas R., E-mail: peterson@ucolick.org
2017-04-01
The Fe i spectrum is critical to many areas of astrophysics, yet many of the high-lying levels remain uncharacterized. To remedy this deficiency, Peterson and Kurucz identified Fe i lines in archival ultraviolet and optical spectra of metal-poor stars, whose warm temperatures favor moderate Fe i excitation. Sixty-five new levels were recovered, with 1500 detectable lines, including several bound levels in the ionization continuum of Fe i. Here, we extend the previous work by identifying 59 additional levels, with 1400 detectable lines, by incorporating new high-resolution UV spectra of warm metal-poor stars recently obtained by the Hubble Space Telescope Imagingmore » Spectrograph. We provide gf values for these transitions, both computed as well as adjusted to fit the stellar spectra. We also expand our spectral calculations to the infrared, confirming three levels by matching high-quality spectra of the Sun and two cool stars in the H -band. The predicted gf values suggest that an additional 3700 Fe i lines should be detectable in existing solar infrared spectra. Extending the empirical line identification work to the infrared would help confirm additional Fe i levels, as would new high-resolution UV spectra of metal-poor turnoff stars below 1900 Å.« less
NASA Astrophysics Data System (ADS)
Peterson, Ruth C.; Kurucz, Robert L.; Ayres, Thomas R.
2017-04-01
The Fe I spectrum is critical to many areas of astrophysics, yet many of the high-lying levels remain uncharacterized. To remedy this deficiency, Peterson & Kurucz identified Fe I lines in archival ultraviolet and optical spectra of metal-poor stars, whose warm temperatures favor moderate Fe I excitation. Sixty-five new levels were recovered, with 1500 detectable lines, including several bound levels in the ionization continuum of Fe I. Here, we extend the previous work by identifying 59 additional levels, with 1400 detectable lines, by incorporating new high-resolution UV spectra of warm metal-poor stars recently obtained by the Hubble Space Telescope Imaging Spectrograph. We provide gf values for these transitions, both computed as well as adjusted to fit the stellar spectra. We also expand our spectral calculations to the infrared, confirming three levels by matching high-quality spectra of the Sun and two cool stars in the H-band. The predicted gf values suggest that an additional 3700 Fe I lines should be detectable in existing solar infrared spectra. Extending the empirical line identification work to the infrared would help confirm additional Fe I levels, as would new high-resolution UV spectra of metal-poor turnoff stars below 1900 Å.
Growth of Acousto-Optic Crystals for Applications in Infrared Region of Spectrum
2005-04-30
Acousto - optic (AO) modulators, deflectors, filters offer convenience, reliability, compact size and fast speed in regulation of optical beams. So far...extremely low acousto - optic figure of merit, which automatically results in high requirements on driving electric power and poor diffraction efficiency. It
Evaluation of the quality of generic polymethylmethacrylate intraocular lenses marketed in India.
Combe, R; Watkins, R; Brian, G
2001-04-01
To determine the quality of single-piece, allpolymethylmethacrylate (PMMA) Intraocular lenses (IOLs) from eght generic manufacturers marketing their product in India. This assessment of quality was made with respect to compliance with internationa standards for the manufacture of IOLs, specifically those parameters most likely to affect patient postoperat ve visual acuity and the long-term biocompatibility of the implanted lens. Ten IOLs from each of eight manufacturers were purchased randomly from commercial retail outlets in India. Each IOL, in a masked fashion, had its physical dimensions, optical performance and cosmetic appearance assessed, using the methods prescribed in ISO 11979-2 and 11979-3. Validation of manufacturing process controls were determined by statistical process contro techniques. Four IOLs from each manufacturer were also tested for the presence of unpolymerized PMMA using gas chromatography. Only lenses from two IOL manufacturers complied with the optical and mechanical standards. All other manufacturers' lenses failed one or more of these tests. Intraocular lenses from only two producers met with surface quality and bulk homogeneity standards. All others exhibited defects such as surface contamination and scratches, poor polishing, and chipped or rough positioning holes. Lenses from two producers exhibited high levels of methylmethacrylate monomer (MMA). Non-clinical grade PMMA starting material may have been used in the manufacture of IOLs by some producers. Critical manufacturing defects occurred in the IOLs from five of the eight producers tested. Only one manufacturer's IOLs met all specifications, and on statistical analysis demonstrated good manufacturing process contro with respect to the properties tested. With the widespread acceptance of IOL implantation in developing countries, such as India, it is essential that in the rush to make this the norm, the quality of implants used not be overlooked.
Minimally invasive surgery: only as good as the picture.
Drury, Nigel E.; Pollard, Rebecca; Dyer, Jonathan P.
2004-01-01
BACKGROUND: In minimally invasive surgery, there is increased reliance on real-time 2-dimensional images. The fibre-optic light lead is one of the most frequently damaged elements of the 'imaging chain', leading to a poor quality picture. METHODS: Light leads with a honeycomb projection were connected to a light source and the resulting beam directed at a sheet of paper. Darkened sectors with diminished or absent light transmission were recorded. RESULTS: All suitable light leads in routine use were examined. A mean of 22.2% (SD 7.8%) of the projection had diminished or absent light transmission. CONCLUSION: Sub-optimal endoscopic equipment was in routine use. PMID:15005945
Exploring Gender Difference in Sleep Quality of Young Adults: Findings from a Large Population Study
Fatima, Yaqoot; Doi, Suhail A.R.; Najman, Jake M.; Mamun, Abdullah Al
2016-01-01
Objectives To explore if gender difference in sleep quality is due to higher prevalence of depression in females, and whether socio-demographic and lifestyle factors have a differential effect on sleep quality in males and females. Methods Youth self-reports and the Pittsburgh Sleep Quality Index were used to assess sleep quality and associated risk factors. Logistic regression analyses were used to analyze the association between various risk factors and poor sleep quality. Results Reports from 3,778 young adults (20.6±0.86 years) indicate a higher prevalence of poor sleep quality in females than males (65.1% vs. 49.8%). It seems that gender difference in poor sleep is independent of depression, socio-demographics, and lifestyle factors, since the higher odds of poor sleep quality in females was robust to adjust for depression, socio-demographics, and lifestyle factors (OR: 1.53, 95% CI: 1.23–1.90). Lifestyle factors (eg, smoking) (OR 1.91; 95% CI 1.05–3.46) were associated with sleep quality in only males. Conclusion Our findings indicate that female vulnerability to poor sleep quality should be explored beyond psycho-social disparities. Perhaps, exploring if the female predisposition to poor sleep quality originates at the biological level could lead to the answer. PMID:28188139
Osonoi, Yusuke; Mita, Tomoya; Osonoi, Takeshi; Saito, Miyoko; Tamasawa, Atsuko; Nakayama, Shiho; Someya, Yuki; Ishida, Hidenori; Kanazawa, Akio; Gosho, Masahiko; Fujitani, Yoshio; Watada, Hirotaka
2015-06-18
While poor sleep quality can worsen cardiovascular risk factors such as glucose and lipid profiles in patients with type 2 diabetes mellitus (T2DM), the relationship between sleep quality and atherosclerosis remains largely unknown. The aim of this study was to examine this relationship. The study participants comprised 724 Japanese T2DM outpatients free of history of cardiovascular diseases. The relationships between sleep quality (assessed by the Pittsburgh Sleep Quality Index (PSQI)) and various clinical and laboratory parameters were investigated. The mean PSQI was 5.1 ± 3.0 (±SD). Patients were divided into three groups based on the total PSQI score; subjects with good sleep quality (n = 462), average sleep quality (n = 185), and poor sleep quality (n = 77). In the age/gender-adjusted model, patients with poor sleep quality tended to be obese, evening type and depressed. However, other lifestyles showed no significant trends. Alanine aminotransferase, fasting blood glucose, HbA1c, systolic blood pressure, urinary albumin excretion, and brachial-ankle pulse wave velocity (baPWV) tended to be higher in patients with poor sleep quality. High baPWV was the only parameter that correlated with poor sleep in a model adjusted for several other lifestyle factors. Our study indicates that poor sleep quality in T2DM patients correlates with increased arterial wall stiffness, a marker of atherosclerosis and a risk factor for cardiovascular diseases.
Smith, Simon Squire; Kozak, Nahum; Sullivan, Karen Anne
2012-03-01
Loneliness and low mood are associated with significant negative health outcomes including poor sleep, but the strength of the evidence underlying these associations varies. There is strong evidence that poor sleep quality and low mood are linked, but only emerging evidence that loneliness and poor sleep are associated. To independently replicate the finding that loneliness and poor subjective sleep quality are associated and to extend past research by investigating lifestyle regularity as a possible mediator of relationships, since lifestyle regularity has been linked to loneliness and poor sleep. Using a cross-sectional design, 97 adults completed standardized measures of loneliness, lifestyle regularity, subjective sleep quality and mood. Loneliness was a significant predictor of sleep quality. Lifestyle regularity was not a predictor of, nor associated with, mood, sleep quality or loneliness. This study provides an important independent replication of the association between poor sleep and loneliness. However, the mechanism underlying this link remains unclear. A theoretically plausible mechanism for this link, lifestyle regularity, does not explain the relationship between loneliness and poor sleep. The nexus between loneliness and poor sleep is unlikely to be broken by altering the social rhythm of patients who present with poor sleep and loneliness.
Domínguez-Vicent, Alberto; Esteve-Taboada, Jose Juan; Recchioni, Alberto; Brautaset, Rune
2018-05-01
To assess the power profile and in vitro optical quality of scleral contact lenses with different powers as a function of the optical aperture. The mini and semiscleral contact lenses (Procornea) were measured for five powers per design. The NIMO TR-1504 (Lambda-X) was used to assess the power profile and Zernike coefficients of each contact lens. Ten measurements per lens were taken at 3- and 6-mm apertures. Furthermore, the optical quality of each lens was described in Zernike coefficients, modulation transfer function, and point spread function (PSF). A convolution of each lens PSF with an eye-chart image was also computed. The optical power fluctuated less than 0.5 diopters (D) along the optical zone of each lens. However, the optical power obtained for some lenses did not match with its corresponding nominal one, the maximum difference being 0.5 D. In optical quality, small differences were obtained among all lenses within the same design. Although significant differences were obtained among lenses (P<0.05), these showed small impact in the image quality of each convolution. Insignificant power fluctuations were obtained along the optical zone measured for each scleral lens. Additionally, the optical quality of both lenses has showed to be independent of the lens power within the same aperture.
Katagiri, Ryoko; Asakura, Keiko; Kobayashi, Satomi; Suga, Hitomi; Sasaki, Satoshi
2014-01-01
Although workers with poor sleep quality are reported to have problems with work performance, few studies have assessed the association between dietary factors and sleep quality using validated indexes. Here, we examined this association using information acquired from validated questionnaires. A total of 3,129 female workers aged 34 to 65 years were analyzed. Dietary intake was assessed using a self-administered diet history questionnaire (DHQ), and subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). The relationship between the intake of several food groups and nutrients and sleep quality was examined using multivariable logistic regression models. The effect of eating habits on sleep quality was also examined. Poor sleep quality was associated with low intake of vegetables (p for trend 0.002) and fish (p for trend 0.04) and high intake of confectionary (p for trend 0.004) and noodles (p for trend 0.03) after adjustment for potential confounding factors (age, body mass index, physical activity, depression score, employment status, alcohol intake and smoking status). Poor sleep quality was also significantly and positively associated with consumption of energy drinks and sugar-sweetened beverages, skipping breakfast, and eating irregularly. In addition, poor sleep quality was significantly associated with high carbohydrate intake (p for trend 0.03). A low intake of vegetables and fish, high intake of confectionary and noodles and unhealthy eating habits were independently associated with poor sleep quality. Poor sleep quality was also associated with high carbohydrate intake in free-living Japanese middle-aged female workers.
Are we doing enough to prevent poor-quality antimalarial medicines in the developing world?
Walker, Erin J; Peterson, Gregory M; Grech, James; Paragalli, Evie; Thomas, Jackson
2018-05-15
Malaria is a deadly parasitic disease that affects more than 3 billion people worldwide, in predominantly resource-poor countries. Despite malaria being preventable and treatable, a large number of adults and children, mostly in Africa, die from this disease each year. One contributor to needless morbidity and mortality is the production and distribution of poor-quality antimalarial medicines; indeed, it is estimated that over 122,000 deaths of children under 5 years of age in sub-Saharan countries were caused by poor-quality antimalarial medicines, in 2013 alone. Poor-quality medicines include those that are deliberately falsified for monetary gain and may contain incorrect amounts or even no active ingredients at all, as well as products that are inadequate due to poor compliance to conventional quality standards and medicines that have degraded over time. Across a number of studies it has been reported that 4-92% of antimalarials tested are poor quality. This represents a massive risk to the population subjected to the use of these medicines, in the form of more severe and prolonged illness, additional costs to individuals who already have very little money, and lack of confidence in treatments. The continuing circulation of poor-quality medicines results from a number of factors, including insufficient regulatory capacity in susceptible countries, inadequate funding to perform regulatory functions, poor coordination between regulatory authorities, and inefficient import/export control systems. To combat the distribution of poor-quality medicines a number of organisations have developed guidelines for the procurement of antimalarials, and programs to educate consumers about the risks of poor-quality medicines and incentivise retailers to identify and report falsified medicines. The development of new technologies to quickly identify poor-quality medicines in the field is also essential, and some significant advances have been made. There has been considerable improvement in the delivery of high-quality antimalarials to those who need them; however, there is still an urgent need for a collective response by the international community, political leaders, regulatory bodies, and pharmaceutical companies. This should include political commitment for enhanced research and development funding, such as for new innovative track-and-trace field devices, and international efforts to strengthen and harmonise drug regulation practices.
Coherent Beam Combining of Fiber Amplifiers via LOCSET (Postprint)
2012-07-10
load on final optics , and atmospheric turbulence compensation [20]. More importantly, tiled array systems are being investigated for extension to...compactness, near diffraction limited beam quality, superior thermal- optical properties, and high optical to optical conversion efficiencies. Despite...including: compactness, near diffraction limited beam quality, superior thermal- optical properties, and high optical to optical conversion efficiencies
Baker, Fiona C; Wolfson, Amy R; Lee, Kathryn A
2009-06-01
To investigate factors associated with poor sleep quality and daytime sleepiness in women living in the United States. Data are presented from the National Sleep Foundation's 2007 Sleep in America Poll that included 959 women (18-64 years of age) surveyed by telephone about their sleep quality, daytime sleepiness, and sociodemographic, health, and lifestyle factors. Poor sleep quality was reported by 27% and daytime sleepiness was reported by 21% of respondents. Logistic multivariate regression analyses revealed that poor sleep quality and daytime sleepiness were both independently associated with poor health, having a sleep disorder, and psychological distress. Also, multivariate analyses showed that women who consumed more caffeinated beverages and those who had more than one job were more likely to report poor sleep quality but not daytime sleepiness. Daytime sleepiness, on the other hand, was independently associated with being black/African American, younger, disabled, having less education, and daytime napping. Poor sleep quality and daytime sleepiness are common in American women and are associated with health-related, as well as sociodemographic, factors. Addressing sleep-related complaints in women is important to improve their daytime functioning and quality of life.
UV-Green Iridescence Predicts Male Quality during Jumping Spider Contests
Lim, Matthew L. M.; Li, Daiqin
2013-01-01
Animal colour signals used in intraspecies communications can generally be attributed to a composite effect of structural and pigmentary colours. Notably, the functional role of iridescent coloration that is ‘purely’ structural (i.e., absence of pigments) is poorly understood. Recent studies reveal that iridescent colorations can reliably indicate individual quality, but evidence of iridescence as a pure structural coloration indicative of male quality during contests and relating to an individual’s resource-holding potential (RHP) is lacking. In age- and size-controlled pairwise male-male contests that escalate from visual displays of aggression to more costly physical fights, we demonstrate that the ultraviolet-green iridescence of Cosmophasis umbratica predicts individual persistence and relates to RHP. Contest initiating males exhibited significantly narrower carapace band separation (i.e., relative spectral positions of UV and green hues) than non-initiators. Asymmetries in carapace and abdomen brightness influenced overall contest duration and escalation. As losers retreated upon having reached their own persistence limits in contests that escalated to physical fights, losers with narrower carapace band separation were significantly more persistence. We propose that the carapace UV-green iridescence of C. umbratica predicts individual persistence and is indicative of a male’s RHP. As the observed UV-green hues of C. umbratica are ‘pure’ optical products of a multilayer reflector system, we suggest that intrasexual variations in the optical properties of the scales’ chitin-air-chitin microstructures are responsible for the observed differences in carapace band separations. PMID:23573210
UV-green iridescence predicts male quality during jumping spider contests.
Lim, Matthew L M; Li, Daiqin
2013-01-01
Animal colour signals used in intraspecies communications can generally be attributed to a composite effect of structural and pigmentary colours. Notably, the functional role of iridescent coloration that is 'purely' structural (i.e., absence of pigments) is poorly understood. Recent studies reveal that iridescent colorations can reliably indicate individual quality, but evidence of iridescence as a pure structural coloration indicative of male quality during contests and relating to an individual's resource-holding potential (RHP) is lacking. In age- and size-controlled pairwise male-male contests that escalate from visual displays of aggression to more costly physical fights, we demonstrate that the ultraviolet-green iridescence of Cosmophasis umbratica predicts individual persistence and relates to RHP. Contest initiating males exhibited significantly narrower carapace band separation (i.e., relative spectral positions of UV and green hues) than non-initiators. Asymmetries in carapace and abdomen brightness influenced overall contest duration and escalation. As losers retreated upon having reached their own persistence limits in contests that escalated to physical fights, losers with narrower carapace band separation were significantly more persistence. We propose that the carapace UV-green iridescence of C. umbratica predicts individual persistence and is indicative of a male's RHP. As the observed UV-green hues of C. umbratica are 'pure' optical products of a multilayer reflector system, we suggest that intrasexual variations in the optical properties of the scales' chitin-air-chitin microstructures are responsible for the observed differences in carapace band separations.
The effect of zolpidem on sleep quality, stress status, and nondipping hypertension.
Huang, Yuli; Mai, Weiyi; Cai, Xiaoyan; Hu, Yunzhao; Song, Yuanbin; Qiu, Ruofeng; Wu, Yanxian; Kuang, Jian
2012-03-01
Poor sleep quality and stress status have previously been shown to be closely associated with higher activation of the sympathetic nervous system and to be independent predictors of nondipping hypertension. This study aimed to evaluate the effects of the non-hypotensive sedative zolpidem on sleep quality, stress status, and nondipping hypertension. A total of 103 nondippers were defined as poor or good sleepers by the Pittsburgh Sleep Quality Index. They were randomized to receive zolpidem or placebo treatment for 30 days. Stress status was assessed by the Perceived Stress Scale, and levels of epinephrine and norepinephrine were examined to investigate the underlying mechanisms. Poor sleepers treated with zolpidem for 30 days showed significant improvements in sleep quality and stress levels (P<0.01). More nondippers were converted to dippers in the group of poor sleepers treated with zolpidem (11 of 22 patients, 50.0%) than in the placebo (2 of 23, 8.7%) (P<0.01). Epinephrine and norepinephrine levels were significantly reduced in poor sleepers treated with zolpidem (P<0.05). The results of this study suggest that zolpidem can improve sleep quality and stress status, and can convert nondippers with poor sleep quality into dippers. It may be an option for treating nondipping hypertensive patients with poor sleep quality. Copyright © 2011 Elsevier B.V. All rights reserved.
Current issues in determining dietary protein quality and metabolic utilization
USDA-ARS?s Scientific Manuscript database
In resource-limited settings, poor dietary quality has a marked negative impact on health, especially during the sensitive periods of pregnancy and first 2 years of life (the first 1000 days) when stunting, poor development and increased risk of later disease develop. Protein quality is often poor o...
Newton, Tamara L; Burns, Vicki Ellison; Miller, James J; Fernandez-Botran, G Rafael
2016-05-01
A marital status of divorced or separated, as opposed to married, predicts increased risk of health problems, but not for all persons. Focusing on one established health risk that has been linked with divorce--poor subjective sleep quality--the present cross-sectional study examined whether a history of physical intimate partner victimization (IPV) helps identify divorced women at potentially greater risk of health problems. Community midlife women with divorce histories, all of whom were free of current IPV, reported on their past month sleep quality and lifetime IPV. The predicted odds of poor sleep quality were significantly greater for women with, versus without, IPV histories. This held after adjusting for socioemotional, medical, or sociodemographic risks. A dose-response relationship between IPV chronicity and poor quality sleep was observed. IPV history may help identify divorced women at increased risk of poor quality sleep and, more broadly, poor health. © The Author(s) 2015.
Wolniczak, Isabella; Cáceres-DelAguila, José Alonso; Palma-Ardiles, Gabriela; Arroyo, Karen J; Solís-Visscher, Rodrigo; Paredes-Yauri, Stephania; Mego-Aquije, Karina; Bernabe-Ortiz, Antonio
2013-01-01
Internet can accelerate information exchange. Social networks are the most accessed especially Facebook. This kind of networks might create dependency with several negative consequences in people's life. The aim of this study was to assess potential association between Facebook dependence and poor sleep quality. A cross sectional study was performed enrolling undergraduate students of the Universidad Peruana de Ciencias Aplicadas, Lima, Peru. The Internet Addiction Questionnaire, adapted to the Facebook case, and the Pittsburgh Sleep Quality Index, were used. A global score of 6 or greater was defined as the cutoff to determine poor sleep quality. Generalized linear model were used to determine prevalence ratios (PR) and 95% confidence intervals (95%CI). A total of 418 students were analyzed; of them, 322 (77.0%) were women, with a mean age of 20.1 (SD: 2.5) years. Facebook dependence was found in 8.6% (95% CI: 5.9%-11.3%), whereas poor sleep quality was present in 55.0% (95% CI: 50.2%-59.8%). A significant association between Facebook dependence and poor sleep quality mainly explained by daytime dysfunction was found (PR = 1.31; IC95%: 1.04-1.67) after adjusting for age, sex and years in the faculty. There is a relationship between Facebook dependence and poor quality of sleep. More than half of students reported poor sleep quality. Strategies to moderate the use of this social network and to improve sleep quality in this population are needed.
A statistical study of the relationship between surface quality and laser induced damage
NASA Astrophysics Data System (ADS)
Turner, Trey; Turchette, Quentin; Martin, Alex R.
2012-11-01
Laser induced damage of optical components is a concern in many applications in the commercial, scientific and military market sectors. Numerous component manufacturers supply "high laser damage threshold" (HLDT) optics to meet the needs of this market, and consumers pay a premium price for these products. While there's no question that HLDT optics are manufactured to more rigorous standards (and are therefore inherently more expensive) than conventional products, it is not clear how this added expense translates directly into better performance. This is because the standard methods for evaluating laser damage, and the underlying assumptions about the validity of traditional laser damage testing, are flawed. In particular, the surface and coating defects that generally lead to laser damage (in many laserparameter regimes of interest) are widely distributed over the component surface with large spaces in between them. As a result, laser damage testing typically doesn't include enough of these defects to achieve the sample sizes necessary to make its results statistically meaningful. The result is a poor correlation between defect characteristics and damage events. This paper establishes specifically why this is the case, and provides some indication of what might be done to remedy the problem.
Tom, Sarah E; Berenson, Abbey B
2013-01-01
Prior studies have not examined the role of psychosocial stress in the relationship between poor sleep quality and obesity among women of lower socioeconomic status (SES). We tested the following hypotheses in a sample of reproductive-age women of lower SES: 1) Poor sleep quality is related to increased risk of obesity, and 2) psychosocial stress confounds this association between poor sleep quality and obesity. A total of 927 women age 16 to 40 years attending public health clinics in Southeastern Texas provided information on the Pittsburgh Sleep Quality Index and sociodemographic and health characteristics, including the Perceived Stress Scale. Height, weight, and waist circumference (WC) were measured in clinic. A series of models examined the associations between sleep disturbance, perceived stress, and weight outcomes, accounting for potential confounding factors. Nearly 30% of women were overweight, and 35% were obese. Half of women had a WC of greater than 35 inches. Most women had poor sleep quality and high levels of stress. Sleep quality and perceived stress were not related to body mass index category or WC in models that adjusted for age and race/ethnicity. Adjusting for potential confounding factors did not alter results. Perceived stress did not modify the association between sleep quality and weight outcomes. Poor sleep quality and psychosocial stress were not related to weight in reproductive-aged women of lower SES. However, poor sleep quality, high stress, overweight, and obesity were common in this group. Copyright © 2013 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.
New ultra metal-poor stars from SDSS: follow-up GTC medium-resolution spectroscopy
NASA Astrophysics Data System (ADS)
Aguado, D. S.; Allende Prieto, C.; González Hernández, J. I.; Rebolo, R.; Caffau, E.
2017-07-01
Context. The first generation of stars formed in the Galaxy left behind the chemical signatures of their nucleosynthesis in the interstellar medium, visible today in the atmospheres of low-mass stars that formed afterwards. Sampling the chemistry of those low-mass provides insight into the first stars. Aims: We aim to increase the samples of stars with extremely low metal abundances, identifying ultra metal-poor stars from spectra with modest spectral resolution and signal-to-noise ratio (S/N). Achieving this goal involves deriving reliable metallicities and carbon abundances from such spectra. Methods: We carry out follow-up observations of faint, V > 19, metal-poor candidates selected from SDSS spectroscopy and observed with the Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) at GTC. The SDSS and follow-up OSIRIS spectra were analyzed using the FERRE code to derive effective temperatures, surface gravities, metallicities and carbon abundances. In addition, a well-known extremely metal-poor star has been included in our sample to calibrate the analysis methodology. Results: We observed and analyzed five metal-poor candidates from modest-quality SDSS spectra. All stars in our sample have been confirmed as extremely metal-poor stars, in the [Fe/H] < -3.3 regime. We report the recognition of J173403+644632, a carbon-enhanced ultra metal-poor dwarf star with [Fe/H] = -4.3 and [C/Fe] = + 3.1. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma. Programme ID GTC2E-16A and ID GTC65-16B.
Association of suicidal ideation with poor sleep quality among Ethiopian adults.
Gelaye, Bizu; Okeiga, Joseph; Ayantoye, Idris; Berhane, Hanna Y; Berhane, Yemane; Williams, Michelle A
2016-12-01
The objective of this study was to examine the extent to which poor sleep quality is associated with suicidal ideation among Ethiopian adults. A cross-sectional study was conducted among 1054 adults attending outpatient clinical facilities in Ethiopia. Standardized questionnaires were utilized to collect data on demographics, sleep quality, lifestyle, and depression status. Depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9), while the Pittsburgh Sleep Quality Index (PSQI) questionnaire was utilized to assess sleep quality. Multivariate logistic regression models were fit to estimate adjusted odds ratio (AOR) and 95 % confidence intervals (95 % CI). The prevalence of suicidal ideation was 24.3 % while poor sleep quality (PSQI global score of >5 vs. ≤5) was endorsed by 60.2 % of participants. After adjustment for confounders including depression, poor sleep quality was associated with more than 3-fold increased odds of suicidal ideation (AOR = 3.59; 95 % CI 2.34-5.51). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 20 % increased odds for suicidal ideation, even after adjusting for depression (AOR = 1.20; 95 % CI 1.14-1.27). Participants with both poor sleep quality and depression had much higher odds (AOR = 23.22, 95 % CI 14.10-38.28) of suicidal ideation as compared with those who had good sleep quality and no depression although inferences from this analysis are limited due to the wide 95 % CI. Suicidal ideation and poor sleep quality are highly prevalent. Individuals with poor sleep quality have higher odds of suicidal ideation. If confirmed, mental health services need to address sleep disturbances seriously to prevent suicidal episodes.
Association of Suicidal Ideation with Poor Sleep Quality among Ethiopian Adults
Gelaye, Bizu; Okeiga, Joseph; Ayantoye, Idris; Berhane, Hanna Y.; Berhane, Yemane; Williams, Michelle A.
2016-01-01
Objective To examine the extent to which poor sleep quality is associated with suicidal ideation among Ethiopian adults. Methods A cross-sectional study was conducted among 1,054 adults attending outpatient clinical facilities in Ethiopia. Standardized questionnaires were utilized to collect data on demographics, sleep quality, lifestyle, and depression status. Depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9), while the Pittsburgh Sleep Quality Index (PSQI) questionnaire was utilized to assess sleep quality. Multivariate logistic regression models were fit to estimate adjusted odds ratio (AOR) and 95% confidence intervals (95%CI). Results The prevalence of suicidal ideation was 24.3% while poor sleep quality (PSQI global score of > 5vs. ≤5) was endorsed by 60.2% of participants. After adjustment for confounders including depression, poor sleep quality was associated with more than 3-fold increased odds of suicidal ideation (AOR=3.46; 95%CI 2.27–5.26). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 20% increased odds for suicidal ideation, even after adjusting for depression (AOR=1.20; 95%CI 1.14–1.27). Participants with both poor sleep quality and depression had much higher odds (AOR=24.9, 95% CI 15.2–40.8) of suicidal ideation as compared with those who had good sleep quality and no depression although inferences from this analysis are limited due to the wide 95%CI. Conclusion Suicidal ideation and poor sleep quality are highly prevalent. Individuals with poor sleep quality have higher odds of suicidal ideation. If confirmed, mental health services need to address sleep disturbances seriously to prevent suicidal episodes. PMID:27771845
Study of generic quality of life in patients operated on for post-prostatectomy incontinence.
Holm, Henriette Veiby; Fosså, Sophie D; Hedlund, Hans; Dahl, Alv A
2013-09-01
The relationship between urological and psychosocial variables, and generic quality of life in patients operated on for post-prostatectomy incontinence has hardly been studied, and our aim was to investigate this relationship. Patients who had an artificial urinary sphincter AMS800 (n = 100) implanted between January 2002 and June 2010 were invited to complete a mailed questionnaire covering demographic data including work ability, urinary and sexual function, anxiety/depression, and generic quality of life. Poor quality of life was defined as a score <40 on either the physical or the mental Short Form 12 summary scales. Of 85 compliant patients, 30 (35%) reported poor generic quality of life and 55 (65%) reported better quality of life at a median follow-up time of 26 months (range 6-104 months). The poor quality of life group showed significantly more overall urinary and sexual problems, and more men had undergone surgical revisions compared with the better quality of life group. Levels of anxiety and depression were significantly higher, and work ability was lower in the poor quality of life group. In multivariate logistic regression models, increased level of depression and impaired work ability, inability to reach orgasm, and not recommending the operation remained significantly associated with poor quality of life. Poor generic quality of life after surgery for post-prostatectomy incontinence is more strongly associated with reduced work ability and depression rather than urinary and sexual problems. © 2013 The Japanese Urological Association.
Martin, Laura E; Pollack, Lauren; McCune, Ashley; Schulte, Erica; Savage, Cary R; Lundgren, Jennifer D
2015-10-30
This study aimed to determine if obese adults with poor versus good sleep quality demonstrate reduced self-regulatory capacity and different patterns of neural activation when making impulsive monetary choices. Six obese, good quality sleepers (M age=44.7 years, M BMI=38.1 kg/m(2)) were compared to 13 obese, poor quality sleepers (M age=42.6, M BMI=39.2 kg/m(2)) on sleep and eating behavior and brain activation in prefrontal and insular regions while engaging in a delay discounting task during functional magnetic resonance imaging (fMRI). Poor quality sleepers demonstrated significantly lower brain activation in the right inferior frontal gyrus, right middle frontal gyrus, and bilateral insula when making immediate and smaller (impulsive) monetary choices compared to the baseline condition. Behaviorally, poor compared to good quality sleepers reported higher scores in the night eating questionnaire. Obese adults with poor sleep quality demonstrate decreased brain activation in multiple regions that regulate cognitive control and interceptive awareness, possibly reducing self-regulatory capacity when making immediately gratifying decisions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Mei, Shuang; Wang, Yudan; Wen, Guojun; Hu, Yang
2018-05-03
Increasing deployment of optical fiber networks and the need for reliable high bandwidth make the task of inspecting optical fiber connector end faces a crucial process that must not be neglected. Traditional end face inspections are usually performed by manual visual methods, which are low in efficiency and poor in precision for long-term industrial applications. More seriously, the inspection results cannot be quantified for subsequent analysis. Aiming at the characteristics of typical defects in the inspection process for optical fiber end faces, we propose a novel method, “difference of min-max ranking filtering” (DO2MR), for detection of region-based defects, e.g., dirt, oil, contamination, pits, and chips, and a special model, a “linear enhancement inspector” (LEI), for the detection of scratches. The DO2MR is a morphology method that intends to determine whether a pixel belongs to a defective region by comparing the difference of gray values of pixels in the neighborhood around the pixel. The LEI is also a morphology method that is designed to search for scratches at different orientations with a special linear detector. These two approaches can be easily integrated into optical inspection equipment for automatic quality verification. As far as we know, this is the first time that complete defect detection methods for optical fiber end faces are available in the literature. Experimental results demonstrate that the proposed DO2MR and LEI models yield good comprehensive performance with high precision and accepted recall rates, and the image-level detection accuracies reach 96.0 and 89.3%, respectively.
Sawah, Mohomad Al; Ruffin, Naeemah; Rimawi, Mohammad; Concerto, Carmen; Aguglia, Eugenio; Chusid, Eileen; Infortuna, Carmenrita; Battaglia, Fortunato
2015-09-01
A cross-sectional survey administered to first- and second-year podiatric medical students aimed to investigate the effect of coffee intake, energy drink consumption, and perceived stress on sleep quality in medical students during their preclinical studies. Ninety-eight of 183 students contacted (53.6%) completed a questionnaire comprising standard instruments measuring sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth Sleepiness scale), and perceived stress (ten-item Perceived Stress Scale). Furthermore, we investigated coffee and energy drink consumption. Logistic regression was conducted to identify factors associated with poor sleep quality and the relation between sleep quality and academic performance (grade point average). High prevalences of poor sleep quality, excessive daytime sleepiness, and perceived stress were reported. In addition, higher odds of developing poor sleep quality were associated with coffee and energy drink intake, perceived stress, and excessive daytime sleepiness. The total Pittsburgh Sleep Quality Index score was inversely correlated with grade point average. First- and second-year podiatric medical students have poor sleep quality. Further research is needed to identify effective strategies to reduce stress and decrease coffee and energy drink intake to minimize their negative effect on sleep quality and academic performance in podiatric medical students.
Overcoming Presbyopia by Manipulating the Eyes' Optics
NASA Astrophysics Data System (ADS)
Zheleznyak, Leonard A.
Presbyopia, the age-related loss of accommodation, is a visual condition affecting all adults over the age of 45 years. In presbyopia, individuals lose the ability to focus on nearby objects, due to a lifelong growth and stiffening of the eye's crystalline lens. This leads to poor near visual performance and affects patients' quality of life. The objective of this thesis is aimed towards the correction of presbyopia and can be divided into four aims. First, we examined the characteristics and limitations of currently available strategies for the correction of presbyopia. A natural-view wavefront sensor was used to objectively measure the accommodative ability of patients implanted with an accommodative intraocular lens (IOL). Although these patients had little accommodative ability based on changes in power, pupil miosis and higher order aberrations led to an improvement in through-focus retinal image quality in some cases. To quantify the through-focus retinal image quality of accommodative and multifocal IOLs directly, an adaptive optics (AO) IOL metrology system was developed. Using this system, the impact of corneal aberrations in regard to presbyopia-correcting IOLs was assessed, providing an objective measure of through-focus retinal image quality and practical guidelines for patient selection. To improve upon existing multifocal designs, we investigated retinal image quality metrics for the prediction of through-focus visual performance. The preferred metric was based on the fidelity of an image convolved with an aberrated point spread function. Using this metric, we investigated the potential of higher order aberrations and pupil amplitude apodization to increase the depth of focus of the presbyopic eye. Thirdly, we investigated modified monovision, a novel binocular approach to presbyopia correction using a binocular AO vision simulator. In modified monovision, different magnitudes of defocus and spherical aberration are introduced to each eye, thereby taking advantage of the binocular visual system. Several experiments using the binocular AO vision simulator found modified monovision led to significant improvements in through-focus visual performance, binocular summation and stereoacuity, as compared to traditional monovision. Finally, we addressed neural factors, affecting visual performance in modified monovision, such as ocular dominance and neural plasticity. We found that pairing modified monovision with a vision training regimen may further improve visual performance beyond the limits set by optics via neural plasticity. This opens the door to an exciting new avenue of vision correction to accompany optical interventions. The research presented in this thesis offers important guidelines for the clinical and scientific communities. Furthermore, the techniques described herein may be applied to other fields of ophthalmology, such as childhood myopia progression.
Machado-Duque, Manuel Enrique; Echeverri Chabur, Jorge Enrique; Machado-Alba, Jorge Enrique
2015-01-01
Quality of sleep and excessive daytime sleepiness (EDS) affect cognitive ability and performance of medical students. This study attempts to determine the prevalence of EDS, sleep quality, and assess their association with poor academic performance in this population. A descriptive, observational study was conducted on a random sample of 217 medical students from the Universidad Tecnológica de Pereira, who completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire and the Epworth sleepiness scale. Sociodemographic, clinic and academic variables were also measured. Multivariate analyses for poor academic performance were performed. The included students had a mean age of 21.7±3.3 years, of whom 59.4% were men. Almost half (49.8%) had EDS criteria, and 79.3% were poor sleepers (PSQI ≥ 5), while 43.3% had poor academic performance during the last semester. The bivariate analysis showed that having used tobacco or alcohol until intoxicated, fairly bad subjective sleep quality, sleep efficiency < 65%, and being a poor sleeper were associated with increased risk of low performance. Sleep efficiency < 65% was statistically associated with poor academic performance (P=.024; OR = 4.23; 95% CI, 1.12-15.42) in the multivariate analysis. A poor sleep quality determined by low efficiency was related to poor academic achievement at the end of semester in medical students. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.
Changes in sleep quality with age-a 36-year follow-up study of Finnish working-aged adults.
Hublin, Christer; Lehtovirta, Mikko; Partinen, Markku; Koskenvuo, Markku; Kaprio, Jaakko
2017-10-19
Long-term follow-up data on changes in sleep quality among middle-aged adults is scarce. We assessed sleep quality in a population-based cohort (n = 4847) of twins born between 1945 and 1957 during a follow-up of 36 years, with four measurement points in 1975, 1981, 1990 and 2011. Sleep quality was categorized as sleeping well, fairly well, fairly poorly or poorly. The mean age at the beginning of follow-up was 24.0, and at the end was 60.3 years. Of all the adults, 71.1% slept well or fairly well at each time-point throughout the follow-up and 0.5% poorly or fairly poorly. The proportion of those sleeping poorly or fairly poorly increased linearly over time; 3.5% among both sexes at the start, and 15.5% among men and 20.9% among women at the end of the follow-up. The last survey indicated a strong association between self-rated health and sleep quality: sleeping poorly or fairly poorly was reported 15 times more frequently by those rating their health as fairly poor than by those rating their health as very good. There was a strong association between indicators of depression and poor sleep. Although many studies have reported increasing frequencies in sleep problems, our results, based on a long-term cohort study, indicate that the majority of people sleep well or fairly well. Sleep quality declines with age, but only a very small fraction of the adults in this long follow-up consistently slept poorly. © 2017 European Sleep Research Society.
Pristine Survey : High-Resolution Spectral Analyses of New Metal-poor Stars
NASA Astrophysics Data System (ADS)
Venn, Kim; Starkenburg, Else; Martin, Nicolas; Kielty, Collin; Youakim, Kris; Arnetsen, Anke
2018-06-01
The Pristine survey (Starkenburg et al. 2017) is a new and very successful metal-poor star survey. Combining high-quality narrow-band CaHK CFHT/MegaCam photometry with existing broadband photometry from SDSS, then very metal-poor stars have been found as confirmed from low-resolution spectroscopy (Youakim et al. 2017). Furthermore, we have extended this survey towards the Galactic bulge in a pilot program to test the capabilities in the highly crowded and (inhomogeneously) extincted bulge (Arentsen et al. 2018). High resolution spectral follow-up analyses have been initiated at the CFHT with Espadons (V<15) and the Gemini/GRACES long optical fibre that also feeds the Espadons spectrograph (15
Wolniczak, Isabella; Cáceres-DelAguila, José Alonso; Palma-Ardiles, Gabriela; Arroyo, Karen J.; Solís-Visscher, Rodrigo; Paredes-Yauri, Stephania; Mego-Aquije, Karina; Bernabe-Ortiz, Antonio
2013-01-01
Objectives Internet can accelerate information exchange. Social networks are the most accessed especially Facebook. This kind of networks might create dependency with several negative consequences in people’s life. The aim of this study was to assess potential association between Facebook dependence and poor sleep quality. Methodology/Principal Findings A cross sectional study was performed enrolling undergraduate students of the Universidad Peruana de Ciencias Aplicadas, Lima, Peru. The Internet Addiction Questionnaire, adapted to the Facebook case, and the Pittsburgh Sleep Quality Index, were used. A global score of 6 or greater was defined as the cutoff to determine poor sleep quality. Generalized linear model were used to determine prevalence ratios (PR) and 95% confidence intervals (95%CI). A total of 418 students were analyzed; of them, 322 (77.0%) were women, with a mean age of 20.1 (SD: 2.5) years. Facebook dependence was found in 8.6% (95% CI: 5.9%–11.3%), whereas poor sleep quality was present in 55.0% (95% CI: 50.2%–59.8%). A significant association between Facebook dependence and poor sleep quality mainly explained by daytime dysfunction was found (PR = 1.31; IC95%: 1.04–1.67) after adjusting for age, sex and years in the faculty. Conclusions There is a relationship between Facebook dependence and poor quality of sleep. More than half of students reported poor sleep quality. Strategies to moderate the use of this social network and to improve sleep quality in this population are needed. PMID:23554978
Bullying as a risk for poor sleep quality among high school students in China.
Zhou, Ying; Guo, Lan; Lu, Ci-yong; Deng, Jian-xiong; He, Yuan; Huang, Jing-hui; Huang, Guo-liang; Deng, Xue-qing; Gao, Xue
2015-01-01
To determine whether involvement in bullying as a bully, victim, or bully-victim was associated with a higher risk of poor sleep quality among high school students in China. A cross-sectional study was conducted. A total of 23,877 high school students were surveyed in six cities in Guangdong Province. All students were asked to complete the adolescent health status questionnaire, which included the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) and bullying involvement. Descriptive statistics were used to evaluate sleep quality and the prevalence of school bullying. Multi-level logistic regression analyses were conducted to examine the association between being victimized and bullying others with sleep quality. Among the 23,877 students, 6,127 (25.66%) reported having poor sleep quality, and 10.89% reported being involved in bullying behaviors. Of the respondents, 1,410 (5.91%) were pure victims of bullying, 401 (1.68%) were bullies and 784 (3.28%) were bully-victims. Frequently being involved in bullying behaviors (being bullied or bullying others) was related to increased risks of poor sleep quality compared with adolescents who were not involved in bullying behaviors. After adjusting for age, sex, and other confounding factors, the students who were being bullied (OR=2.05, 95%CI=1.81-2.32), bullied others (OR=2.30, 95%CI=1.85-2.86) or both (OR=2.58, 95%CI=2.20-3.03) were at a higher risk for poor sleep quality. Poor sleep quality among high school students is highly prevalent, and school bullying is prevalent among adolescents in China. The present results suggested that being involved in school bullying might be a risk factor for poor sleep quality among adolescents.
Bullying as a Risk for Poor Sleep Quality among High School Students in China
Lu, Ci-yong; Deng, Jian-xiong; Huang, Jing-hui; Huang, Guo-liang; Deng, Xue-qing; Gao, Xue
2015-01-01
Objective To determine whether involvement in bullying as a bully, victim, or bully-victim was associated with a higher risk of poor sleep quality among high school students in China. Methods A cross-sectional study was conducted. A total of 23,877 high school students were surveyed in six cities in Guangdong Province. All students were asked to complete the adolescent health status questionnaire, which included the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) and bullying involvement. Descriptive statistics were used to evaluate sleep quality and the prevalence of school bullying. Multi-level logistic regression analyses were conducted to examine the association between being victimized and bullying others with sleep quality. Results Among the 23,877 students, 6,127 (25.66%) reported having poor sleep quality, and 10.89% reported being involved in bullying behaviors. Of the respondents, 1,410 (5.91%) were pure victims of bullying, 401 (1.68%) were bullies and 784 (3.28%) were bully-victims. Frequently being involved in bullying behaviors (being bullied or bullying others) was related to increased risks of poor sleep quality compared with adolescents who were not involved in bullying behaviors. After adjusting for age, sex, and other confounding factors, the students who were being bullied (OR=2.05, 95%CI=1.81-2.32), bullied others (OR=2.30, 95%CI=1.85-2.86) or both (OR=2.58, 95%CI=2.20-3.03) were at a higher risk for poor sleep quality. Conclusions Poor sleep quality among high school students is highly prevalent, and school bullying is prevalent among adolescents in China. The present results suggested that being involved in school bullying might be a risk factor for poor sleep quality among adolescents. PMID:25811479
Fidalgo, Bruno M R; Crabb, David P; Lawrenson, John G
2015-05-01
To evaluate methodological and reporting quality of diagnostic accuracy studies of perimetry in glaucoma and to determine whether there had been any improvement since the publication of the Standards for Reporting of Diagnostic Accuracy (STARD) guidelines. A systematic review of English language articles published between 1993 and 2013 reporting the diagnostic accuracy of perimetry in glaucoma. Articles were appraised for methodological quality using the 14-item Quality assessment tool for diagnostic accuracy studies (QUADAS) and evaluated for quality of reporting by applying the STARD checklist. Fifty-eight articles were appraised. Overall methodological quality of these studies was moderate with a median number of QUADAS items rated as 'yes' equal to nine (out of a maximum of 14) (IQR 7-10). The studies were often poorly reported; median score of STARD items fully reported was 11 out of 25 (IQR 10-14). A comparison of the studies published in 10-year periods before and after the publication of the STARD checklist in 2003 found quality of reporting had not substantially improved. Methodological and reporting quality of diagnostic accuracy studies of perimetry is sub-optimal and appears not to have improved substantially following the development of the STARD reporting guidance. This observation is consistent with previous studies in ophthalmology and in other medical specialities. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.
Is there a link between hospital profit and quality?
Cleverley, W O; Harvey, R K
1992-09-01
In industrial firms, high perceived quality in products or services leads to high return on investment. The link between high quality and high profit is more difficult to document for healthcare products and services. An even more important question for healthcare managers is whether there is a link between poor-quality services and low profitability. A study of a small sample of HCFA high-mortality hospitals shows that poor quality hospitals are less profitable. Although the demand for the products and services of poor-quality hospitals is relatively strong, such hospitals are underinvested in assets and understaffed, the study shows.
Throughput of Coded Optical CDMA Systems with AND Detectors
NASA Astrophysics Data System (ADS)
Memon, Kehkashan A.; Umrani, Fahim A.; Umrani, A. W.; Umrani, Naveed A.
2012-09-01
Conventional detection techniques used in optical code-division multiple access (OCDMA) systems are not optimal and result in poor bit error rate performance. This paper analyzes the coded performance of optical CDMA systems with AND detectors for enhanced throughput efficiencies and improved error rate performance. The results show that the use of AND detectors significantly improve the performance of an optical channel.
Poor Sleep Quality is Independently Associated with Physical Disability in Older Adults
Chien, Meng-Yueh; Chen, Hsi-Chung
2015-01-01
Study Objective: We aimed to evaluate the association between sleep quality and physical disability in community-dwelling older adults. Methods: There were 213 community-dwelling adults (76 men and 137 women) aged 65 years and above participated into this investigation. The Groningen Activity Restriction Scale and the Pittsburgh Sleep Quality Index were utilized to evaluate physical disability and subjective sleep quality, respectively. Global functional capacity was measured by the 6-minute walk test (6MWT). The Mini Mental State Examination and the Chinese Geriatric Depression Screening Scale were used to evaluate cognitive function and depression. Results: Univariate analysis revealed a correlation between physical disability and poor sleep quality, older age, 2 or more comorbidities, depression, functional capacity, and poor cognitive function. However, in the multivariate analyses, depression failed to show significant association with physical disability. In contrast, an independent association was observed between poor sleep quality and physical disability (OR = 2.03; 95% CI: 1.02–4.05). Conclusions: In community-dwelling older adults, subjective poor sleep was significantly associated with physical disability, even after controlling for the effects of other established risk factors. Citation: Chien MY, Chen HC. Poor sleep quality is independently associated with physical disability in older adults. J Clin Sleep Med 2015;11(3):225–232. PMID:25515275
Requirements model for an e-Health awareness portal
NASA Astrophysics Data System (ADS)
Hussain, Azham; Mkpojiogu, Emmanuel O. C.; Nawi, Mohd Nasrun M.
2016-08-01
Requirements engineering is at the heart and foundation of software engineering process. Poor quality requirements inevitably lead to poor quality software solutions. Also, poor requirement modeling is tantamount to designing a poor quality product. So, quality assured requirements development collaborates fine with usable products in giving the software product the needed quality it demands. In the light of the foregoing, the requirements for an e-Ebola Awareness Portal were modeled with a good attention given to these software engineering concerns. The requirements for the e-Health Awareness Portal are modeled as a contribution to the fight against Ebola and helps in the fulfillment of the United Nation's Millennium Development Goal No. 6. In this study requirements were modeled using UML 2.0 modeling technique.
Statistical corruption in Beijing's air quality data has likely ended in 2012
NASA Astrophysics Data System (ADS)
Stoerk, Thomas
2016-02-01
This research documents changes in likely misreporting in official air quality data from Beijing for the years 2008-2013. It is shown that, consistent with prior research, the official Chinese data report suspiciously few observations that exceed the politically important Blue Sky Day threshold, a particular air pollution level used to evaluate local officials, and an excess of observations just below that threshold. Similar data, measured by the US Embassy in Beijing, do not show this irregularity. To document likely misreporting, this analysis proposes a new way of comparing air quality data via Benford's Law, a statistical regularity known to fit air pollution data. Using this method to compare the official data to the US Embassy data for the first time, I find that the Chinese data fit Benford's Law poorly until a change in air quality measurements at the end of 2012. From 2013 onwards, the Chinese data fit Benford's Law closely. The US Embassy data, by contrast, exhibit no variation over time in the fit with Benford's Law, implying that the underlying pollution processes remain unchanged. These findings suggest that misreporting of air quality data for Beijing has likely ended in 2012. Additionally, I use aerosol optical density data to show the general applicability of this method of detecting likely misreporting in air pollution data.
Musa, Nor Asma; Moy, Foong Ming; Wong, Li Ping
2018-05-31
This study aimed to determine the prevalence and factors associated with poor sleep quality among secondary school teachers in the state of Selangor, Malaysia. This was a cross sectional study, conducted in two phases. Phase I tested the reliability of the Pittsburgh Sleep Quality Index in the Malay language (M-PSQI), whereas Phase II determined the prevalence and factors associated with poor sleep quality where a total of 1871 secondary school teachers were studied. Participants were recruited using multistage sampling. Self-administered questionnaire was used to collect data on socio-demographic and teaching characteristics, comorbidities and characteristics of sleep. The M-PSQI was used to measure sleep quality. The Depression Anxiety Stress Scale-21 was used to measure mental health status. Results showed that the M-PSQI had a good internal consistency and moderate reliability. The prevalence of poor sleep quality was 61 (95% CI: 54-67) %. Total teaching hours/day, depression and stress were significantly associated with poor sleep quality in the univariate analysis, while only stress (OR 1.04; 95% CI 1.02-1.05%) remained significant in the multivariate analyses. In conclusion, stress level of the secondary school teachers should be reduced to improve sleep quality.
A study on the sleep quality of incoming university students.
Cheng, Shu Hui; Shih, Chi-Chen; Lee, I Hui; Hou, Yi-Wen; Chen, Kao Chin; Chen, Kow-Tong; Yang, Yen Kuang; Yang, Yi Ching
2012-05-30
This study was designed to examine the prevalence and the risk factors of poor sleep quality in 4318 incoming university students in Taiwan. The test battery comprised a self-administered structured questionnaire, including items related to personal medical history and lifestyle habits, the Measurement of Support Functions (MSF), Pittsburgh Sleep Quality Index (PSQI), Chinese Internet Addiction Scale-Revision (CIAS-R), neuroticism subscale of the Maudsley Personality Inventory (MPI), and the 12-item Chinese Health Questionnaire (CHQ-12). Of the total study population, 2360 students (54.7%) were classified into the poor sleep quality group, as defined by a PSQI score ≥6. Based on the results of multivariate logistic regression analysis, poor sleep quality was significantly associated with undergraduate students, female gender, skipping breakfast, tea drinking, a higher tendency toward internet addition, poor social support, higher neuroticism, and higher CHQ scores. Poor sleep quality is prevalent among incoming university students in Taiwan, and more work is needed on the identification of the factors influencing poor sleep, and in providing systematic education in the importance of sleep and time management skills to university students. Copyright © 2012 Elsevier Ltd. All rights reserved.
[Cognitive disorders in patients with chronic mercury intoxication].
Katamanova, E V; Shevchenko, O I; Lakhman, O L; Denisova, I A
2014-01-01
To assess severity of cognitive disorders in chronic mercury intoxication, the authors performed claster and discrimination analysis of neuropsychologic and neurophysiologic research data from workers exposed to mercury during long length of service, from patients with early and marked stages of chronic mercurial intoxication. Cognitive disorders in chronic mercurial intoxication have three severity degrees, in the light degree disorders patients demonstrate lower amplitude of cognitive evoked potentials, poor long-term memory and associative thinking. Moderate cognitive disorders are characterized by decreased visual, long-term memory, concentration of attention, poor optic and spatial gnosis. Marked cognitive disorders with chronic mercurial intoxication present with more decreased long-term, short-term, picturesque memory, poor intellect, optic and spatial gnosis and associative thinking.
The impact of sleep and psychiatric symptoms on alcohol consequences among young adults.
Miller, Mary Beth; Van Reen, Eliza; Barker, David H; Roane, Brandy M; Borsari, Brian; McGeary, John E; Seifer, Ronald; Carskadon, Mary A
2017-03-01
Independent lines of research have documented links between psychiatric symptoms and poor sleep quality, psychiatric symptoms and alcohol use, and alcohol use and poor sleep quality. The current study examined the synergistic effect of poor sleep quality and psychiatric symptoms on alcohol-related consequences in heavy-drinking young adults. Matriculating college students reporting at least one heavy drinking episode over the first nine weeks of the semester (N=385, 52% female) were categorized as experiencing 'good' (n=280) versus 'poor' sleep quality (n=105) and screening 'positive' (n=203) or 'negative' (n=182) for a psychiatric disorder. Sleep quality was assessed using the Pittsburgh Sleep Quality Index; psychiatric diagnosis was assessed using the Psychiatric Diagnostic Screening Questionnaire; and alcohol-related consequences were assessed using the Brief Young Adult Alcohol Consequences Questionnaire. General linear models were used to examine the main effects and interaction between sleep quality and psychiatric symptoms on alcohol-related consequences. Sleep quality moderated the association between psychiatric screen and alcohol-related consequences among heavy-drinking college students, such that psychiatric symptoms were associated with more alcohol-related consequences in the context of poor sleep quality. The combination of poor sleep quality and psychiatric symptoms is associated with increased alcohol-related consequences among heavy-drinking college students. Given the significant interaction between these symptoms, healthcare providers are encouraged to screen for the presence of sleep and psychiatric disorders among heavy-drinking young adults and to provide empirically-supported treatments as appropriate. Copyright © 2016 Elsevier Ltd. All rights reserved.
Teles, Mariza Alves Barbosa; Barbosa, Mirna Rossi; Vargas, Andréa Maria Duarte; Gomes, Viviane Elizângela; Ferreira, Efigênia Ferreira e; Martins, Andréa Maria Eleutério de Barros Lima; Ferreira, Raquel Conceição
2014-05-15
Workers in Primary Health Care are often exposed to stressful conditions at work. This study investigated the association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers. This cross-sectional study included all 797 Primary Health Care workers of a medium-sized city, Brazil: doctors, nurses, nursing technicians and nursing assistants, dentists, oral health technicians, and auxiliary oral hygienists, and community health workers. Data were collected by interviews. Quality of life was assessed using the WHOQOL-BREF; general quality of life, as well as the physical, psychological, social and environmental domains were considered, with scores from 0 to 100. Higher scores indicate a better quality of life. Poor quality of life was defined by the lowest quartiles of the WHOQOL score distributions for each of the domains. Adverse psychosocial work conditions were investigated by the Effort-Reward Imbalance model. Associations were verified using multiple logistic regression. Poor quality of life was observed in 117 (15.4%) workers. Workers with imbalanced effort-reward (high effort/low reward) had an increased probability of general poor quality of life (OR = 1.91; 1.07–3.42), and in the physical (OR = 1.62; 1.02–2.66), and environmental (OR = 2.39; 1.37–4.16) domains; those with low effort/low reward demonstrated a greater probability of poor quality of life in the social domain (OR = 1.82; 1.00–3.30). Workers with overcommitment at work had an increased likelihood of poor quality of life in the physical (OR = 1.55, 1.06–2.26) and environmental (OR = 1.69; 1.08–2.65) domains. These associations were independent of individual characteristics, job characteristics, lifestyle, perception of general health, or psychological and biological functions. There is an association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers.
2014-01-01
Background Workers in Primary Health Care are often exposed to stressful conditions at work. This study investigated the association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers. Methods This cross-sectional study included all 797 Primary Health Care workers of a medium-sized city, Brazil: doctors, nurses, nursing technicians and nursing assistants, dentists, oral health technicians, and auxiliary oral hygienists, and community health workers. Data were collected by interviews. Quality of life was assessed using the WHOQOL-BREF; general quality of life, as well as the physical, psychological, social and environmental domains were considered, with scores from 0 to 100. Higher scores indicate a better quality of life. Poor quality of life was defined by the lowest quartiles of the WHOQOL score distributions for each of the domains. Adverse psychosocial work conditions were investigated by the Effort-Reward Imbalance model. Associations were verified using multiple logistic regression. Results Poor quality of life was observed in 117 (15.4%) workers. Workers with imbalanced effort-reward (high effort/low reward) had an increased probability of general poor quality of life (OR = 1.91; 1.07–3.42), and in the physical (OR = 1.62; 1.02–2.66), and environmental (OR = 2.39; 1.37–4.16) domains; those with low effort/low reward demonstrated a greater probability of poor quality of life in the social domain (OR = 1.82; 1.00–3.30). Workers with overcommitment at work had an increased likelihood of poor quality of life in the physical (OR = 1.55, 1.06–2.26) and environmental (OR = 1.69; 1.08–2.65) domains. These associations were independent of individual characteristics, job characteristics, lifestyle, perception of general health, or psychological and biological functions. Conclusions There is an association between adverse psychosocial work conditions and poor quality of life among Primary Health Care workers. PMID:24884707
NASA Astrophysics Data System (ADS)
Huntington, S. T.; Jarvis, S. P.
2003-05-01
Scanning near field optical microscopy (SNOM) probes are typically tapered optical fibers with metallic coatings. The tip diameters are generally in excess of 300 nm and thus provide poor topographical resolution. Here we report on the attachment multiwalled carbon nanotubes to the probes in order to substantially enhance the topographical resolution, without adversely affecting the optical resolution.
Production of Optical Quality Free Standing Diamond Wafer
2008-05-19
Title : Production of Optical Quality Free Standing Diamond Wafer Prime Contractor : Onyx Optics, Inc. 6551 Sierra Lane Dublin, Ca 94568...www.onyxoptics.com Program Manager : Helmuth Meissner Onyx Optics, Inc. 6551 Sierra Lane Dublin, CA 94568 Email: hmeissner@onyxoptics.com Ph: 925...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Onyx Optics, Inc. 6551 Sierra Lane Dublin, Ca 94568 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING
NASA Astrophysics Data System (ADS)
Mignani, A. G.; Ciaccheri, L.; Mencaglia, A. A.; Diaz-Herrera, N.; Garcia-Allende, P. B.; Ottevaere, H.; Thienpont, H.; Attilio, C.; Cimato, A.; Francalanci, S.; Paccagnini, A.; Pavone, F. S.
2009-01-01
Absorption spectroscopy in the wide 200-1700 nm spectral range is carried out by means of optical fiber instrumentation to achieve a digital mapping of liquids for the prediction of important quality parameters. Extra virgin olive oils from Italy and lubricant oils from turbines with different degrees of degradation were considered as "case studies". The spectral data were processed by means of multivariate analysis so as to obtain a correlation to quality parameters. In practice, the wide range absorption spectra were considered as an optical signature of the liquids from which to extract product quality information. The optical signatures of extra virgin olive oils were used to predict the content of the most important fatty acids. The optical signatures of lubricant oils were used to predict the concentration of the most important parameters for indicating the oil's degree of degradation, such as TAN, JOAP anti-wear index, and water content.
Lo, Catherine Mei-Han; Lee, Paul H
2014-03-01
Poor sleep in later life is a global issue that reduces many individuals' quality of life (QOL). The purpose of this pilot study was to test the feasibility and effects of a simplified tai chi exercise intervention on sleep quality and QOL among Chinese community-dwelling older adults with poor sleep quality. This single-group, descriptive feasibility study included 34 individuals with poor sleep quality who agreed to participate in a 12-week tai chi intervention. Twenty-six individuals completed the program (23.5% dropout rate). Older adults with poor sleep quality who completed the intervention showed significant improvement in the Medical Outcomes Study Short Form-36 mental component and the Pittsburgh Sleep Quality Index global and component scores. The low recruitment and attendance and high dropout rates might be associated with participants' age, gender, and sleep quality. Further long-term studies are required to examine the potential effects of the tai chi intervention. [Journal of Gerontological Nursing, 40(3), 46-52.]. Copyright 2014, SLACK Incorporated.
Poor sleep quality is independently associated with physical disability in older adults.
Chien, Meng-Yueh; Chen, Hsi-Chung
2015-03-15
We aimed to evaluate the association between sleep quality and physical disability in community-dwelling older adults. There were 213 community-dwelling adults (76 men and 137 women) aged 65 years and above participated into this investigation. The Groningen Activity Restriction Scale and the Pittsburgh Sleep Quality Index were utilized to evaluate physical disability and subjective sleep quality, respectively. Global functional capacity was measured by the 6-minute walk test (6MWT). The Mini Mental State Examination and the Chinese Geriatric Depression Screening Scale were used to evaluate cognitive function and depression. Univariate analysis revealed a correlation between physical disability and poor sleep quality, older age, 2 or more comorbidities, depression, functional capacity, and poor cognitive function. However, in the multivariate analyses, depression failed to show significant association with physical disability. In contrast, an independent association was observed between poor sleep quality and physical disability (OR = 2.03; 95% CI: 1.02-4.05). In community-dwelling older adults, subjective poor sleep was significantly associated with physical disability, even after controlling for the effects of other established risk factors. © 2014 American Academy of Sleep Medicine.
Wang, Lan; Qin, Peng; Zhao, Yunshan; Duan, Shengyun; Zhang, Qing; Liu, Ying; Hu, Yueling; Sun, Juan
2016-10-30
Medical students face new challenges at the beginning of college life, such as being responsible for oneself, an unfamiliar environment, social obligations, and academic stress, all of which influence or even heavily change their sleep quality and life, leading to sleep-related problems to some degree. This study investigated the relationship between sleep quality and behavior among students at the Inner Mongolia Medical University in China. Self-administered questionnaires were used to collect information on sociodemographic characteristics and lifestyle habits. The Pittsburgh Sleep Quality Index was also used. A total of 6044 and 6085 students completed the questionnaires in 2011 and 2013. According to the index, 27.8% (1694) of students had poor sleep quality with major risk factors being poor academic performance and interpersonal relationships in 2013. Among others, regular exercise less than three times a week, skipping breakfast, and studying in higher grades were associated with poor sleep quality. These results will help university administrators understand the risk factors of poor sleep quality among students, which can be improved through individual efforts, and provide adequate counseling and systematic education to improve their behavior and lifestyle. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Vision rehabilitation interventions following mild traumatic brain injury: a scoping review.
Simpson-Jones, Mary E; Hunt, Anne W
2018-04-10
To broadly examine the literature to identify vision interventions following mild traumatic brain injury. Objectives are to identify: (1) evidence-informed interventions for individuals with visual dysfunction after mild traumatic brain injury; (2) professions providing these interventions; (3) gaps in the literature and areas for further research. A scoping review was conducted of four electronic databases of peer-reviewed literature from the databases earliest records to June 2017. Articles were included if the study population was mild traumatic brain injury/concussion and a vision rehabilitation intervention was tested. Two independent reviewers screened articles for inclusion, extracted data, and identified themes. The initial search identified 3111 records. Following exclusions, 22 articles were included in the final review. Nine studies evaluated optical devices, such as corrective spectacles, contact lenses, prisms, or binasal occlusion. Two studies assessed vision therapy. Ten studies examined vision therapy using optical devices. One study investigated hyperbaric oxygen therapy. Optometrists performed these interventions in most of the studies. Future research should address quality appraisal of this literature, interventions that include older adult and pediatric populations, and interdisciplinary interventions. There are promising interventions for vision deficits following mild traumatic brain injury. However, there are multiple gaps in the literature that should be addressed by future research. Implications for Rehabilitation Mild traumatic brain injury may result in visual deficits that can contribute to poor concentration, headaches, fatigue, problems reading, difficulties engaging in meaningful daily activities, and overall reduced quality of life. Promising interventions for vision rehabilitation following mild traumatic brain injury include the use of optical devices (e.g., prism glasses), vision or oculomotor therapy (e.g., targeted exercises to train eye movements), and a combination of optical devices and vision therapy. Rehabilitation Professionals (e.g., optometrists, occupational therapists, physiotherapists) have an important role in screening for vision impairments, recommending referrals appropriately to vision specialists, and/or assessing and treating functional vision deficits in individuals with mild traumatic brain injury.
Thin film processing of photorefractive BaTiO3
NASA Technical Reports Server (NTRS)
Schuster, Paul R.
1993-01-01
During the period covered by this report, October 11, 1991 through October 10, 1992, the research has progressed in a number of different areas. The sol-gel technique was initially studied and experimentally evaluated for depositing films of BaTiO3. The difficulties with the precursors and the poor quality of the films deposited lead to the investigation of pulsed laser deposition as an alternative approach. The development of the pulsed laser deposition technique has resulted in continuous improvements to the quality of deposited films of BaTiO3. The initial depositions of BaTiO3 resulted in amorphous films, however, as the pulsed laser deposition technique continued to evolve, films were deposited in the polycrystalline state, then the textured polycrystalline state, and most recently heteroepitaxial films have also been successfully deposited on cubic (100) oriented SrTiO3 substrates. A technique for poling samples at room temperature and in air is also undergoing development with some very preliminary but positive results. The analytical techniques, which include x-ray diffraction, ferroelectric analysis, UV-Vis spectrophotometry, scanning electron microscopy with x-ray compositional analysis, optical and polarized light microscopy, and surface profilometry have been enhanced to allow for more detailed evaluation of the samples. In the area of optical characterization, a pulsed Nd:YAG laser has been incorporated into the experimental configuration. Now data can also be acquired within various temporal domains resulting in more detailed information on the optical response of the samples and on their photorefractive sensitivity. The recent establishment of collaborative efforts with two departments at Johns Hopkins University and the Army Research Lab at Fort Belvoir has also produced preliminary results using the metallo-organic decomposition technique as an alternative method for thin film processing of BaTiO3. RF and DC sputtering is another film deposition approach that should be initiated in the near future. Other techniques for optical characterization, which may even allow for intragrannular (within single grains) investigations, are also being considered.
Functional Near-Infrared Spectroscopy Signals Measure Neuronal Activity in the Cortex
NASA Technical Reports Server (NTRS)
Harrivel, Angela; Hearn, Tristan
2013-01-01
Functional near infrared spectroscopy (fNIRS) is an emerging optical neuroimaging technology that indirectly measures neuronal activity in the cortex via neurovascular coupling. It quantifies hemoglobin concentration ([Hb]) and thus measures the same hemodynamic response as functional magnetic resonance imaging (fMRI), but is portable, non-confining, relatively inexpensive, and is appropriate for long-duration monitoring and use at the bedside. Like fMRI, it is noninvasive and safe for repeated measurements. Patterns of [Hb] changes are used to classify cognitive state. Thus, fNIRS technology offers much potential for application in operational contexts. For instance, the use of fNIRS to detect the mental state of commercial aircraft operators in near real time could allow intelligent flight decks of the future to optimally support human performance in the interest of safety by responding to hazardous mental states of the operator. However, many opportunities remain for improving robustness and reliability. It is desirable to reduce the impact of motion and poor optical coupling of probes to the skin. Such artifacts degrade signal quality and thus cognitive state classification accuracy. Field application calls for further development of algorithms and filters for the automation of bad channel detection and dynamic artifact removal. This work introduces a novel adaptive filter method for automated real-time fNIRS signal quality detection and improvement. The output signal (after filtering) will have had contributions from motion and poor coupling reduced or removed, thus leaving a signal more indicative of changes due to hemodynamic brain activations of interest. Cognitive state classifications based on these signals reflect brain activity more reliably. The filter has been tested successfully with both synthetic and real human subject data, and requires no auxiliary measurement. This method could be implemented as a real-time filtering option or bad channel rejection feature of software used with frequency domain fNIRS instruments for signal acquisition and processing. Use of this method could improve the reliability of any operational or real-world application of fNIRS in which motion is an inherent part of the functional task of interest. Other optical diagnostic techniques (e.g., for NIR medical diagnosis) also may benefit from the reduction of probe motion artifact during any use in which motion avoidance would be impractical or limit usability.
Evaluation of sleep quality in subjects with chronic nononcologic pain.
Covarrubias-Gomez, Alfredo; Mendoza-Reyes, Jonathan J
2013-08-01
A survey conducted by the National Sleep Foundation found that 20% of Americans have sleep disorders and 45% experience chronic pain. Several authors evaluated the interrelationship between these functions using various instruments such the Pittsburgh Sleep Quality Index (PSQI) and identified that 34% of subjects in the general population have a poor quality of sleep, but there are few studies that assess the quality of sleep in patients with chronic pain of nonmalignant origin. We undertook this study to evaluate the quality of sleep using the PSQI in patients with chronic pain unrelated to cancer. We conducted a clinical, nonrandomized, uncontrolled, descriptive, and prospective study, applying the PSQI through a direct one-time interview to 311 subjects with chronic pain unrelated to cancer. According to the categorization of the PSQI between good and poor sleepers, 89% of the subjects were poor sleepers (n = 276). There are significant differences in pain intensity according to the categorization of the PSQI, with a higher intensity shown in the "poor sleepers" (analysis of variance [ANOVA], P = .030). Using a linear regression model to estimate the curve, a higher score is rated on the PSQI global score (ANOVA, P = .000, R(2) = .46) with the increase of the intensity of the pain. We conclude that "poor sleepers" or those who considered their sleep as "poor quality" have significantly higher pain intensity. This suggests that intensity of pain plays a role in evaluating the quality of sleep in the subjective perception of sleep and instruments that assess quality.
de Carlo, Talisa E; Chin, Adam T; Bonini Filho, Marco A; Adhi, Mehreen; Branchini, Lauren; Salz, David A; Baumal, Caroline R; Crawford, Courtney; Reichel, Elias; Witkin, Andre J; Duker, Jay S; Waheed, Nadia K
2015-11-01
To evaluate the ability of optical coherence tomography angiography to detect early microvascular changes in eyes of diabetic individuals without clinical retinopathy. Prospective observational study of 61 eyes of 39 patients with diabetes mellitus and 28 control eyes of 22 age-matched healthy subjects that received imaging using optical coherence tomography angiography between August 2014 and March 2015. Eyes with concomitant retinal, optic nerve, and vitreoretinal interface diseases and/or poor-quality images were excluded. Foveal avascular zone size and irregularity, vessel beading and tortuosity, capillary nonperfusion, and microaneurysm were evaluated. Foveal avascular zone size measured 0.348 mm² (0.1085-0.671) in diabetic eyes and 0.288 mm² (0.07-0.434) in control eyes (P = 0.04). Foveal avascular zone remodeling was seen more often in diabetic than control eyes (36% and 11%, respectively; P = 0.01). Capillary nonperfusion was noted in 21% of diabetic eyes and 4% of control eyes (P = 0.03). Microaneurysms and venous beading were noted in less than 10% of both diabetic and control eyes. Both diabetic and healthy control eyes demonstrated tortuous vessels in 21% and 25% of eyes, respectively. Optical coherence tomography angiography was able to image foveal microvascular changes that were not detected by clinical examination in diabetic eyes. Changes to the foveal avascular zone and capillary nonperfusion were more prevalent in diabetic eyes, whereas vessel tortuosity was observed with a similar frequency in normal and diabetic eyes. Optical coherence tomography angiography may be able to detect diabetic eyes at risk of developing retinopathy and to screen for diabetes quickly and noninvasively before the systemic diagnosis is made.
ERIC Educational Resources Information Center
Busler, Jessica; Kirk, Claire; Keeley, Jared; Buskist, William
2017-01-01
Across three phases, we investigated college students' perceptions of poor college teaching to develop a typology of poor teaching behaviors. In Phase 1, students generated a list of qualities representative of poor teaching. In Phase 2, another group of students assigned behavioral correspondents to these qualities, resulting in a list of 15 poor…
Combating poor-quality anti-malarial medicines: a call to action.
Bassat, Quique; Tanner, Marcel; Guerin, Philippe J; Stricker, Kirstin; Hamed, Kamal
2016-06-01
The circulation of poor-quality medicines continues to undermine the fight against many life-threatening diseases. Anti-malarial medicines appear to have been particularly compromised and present a major public health threat in malaria-endemic countries, negatively affecting individuals and their communities. Concerted collaborative efforts are required from global, regional and national organizations, involving the public and private sectors, to address the problem. While many initiatives are underway, a number of unmet needs deserve urgent and increased multisector attention. At the global level, there is a need for an international public health legal framework or treaty on poor-quality medicines, with statutes suitable for integration into national laws. In addition, increased international efforts are required to strengthen the governance of global supply chains and enhance cooperation between national medicine regulation authorities and law enforcement bodies. Increased investment is needed in innovative technologies that will enable healthcare teams to detect poor-quality medicines at all levels of the supply chain. At the regional level, a number of initiatives would be beneficial-key areas are standardization, simplification, and reciprocal recognition of registration processes and development of quality control capacity in regional centres of excellence that are better aligned with public health needs; improved surveillance methods and creation of a framework for compulsory and transparent reporting of poor-quality medicines; additional support for national medicine regulation authorities and other national partner authorities; and an increase in support for regional laboratories to boost their capabilities in detecting poor-quality medicines. It is vital that all stakeholders involved in efforts against poor-quality anti-malarial medicines extend and strengthen their actions in these critical areas and thus effectively support global health development and malaria elimination programmes.
Severe Air Pollution in New Delhi View by NASA MISR
2016-11-16
New Delhi, India's capital city, is currently suffering though a period of particularly poor air quality. In early November 2016, monitors at various locations in the area posted air quality index measurements as high as the 900s (the most severe ranking, "hazardous," is any air quality index measurement over 300). Thousands of schools have been closed, and a survey by the Associate Chambers of Commerce and Industry of India reports that 10 percent of the city's workers called in sick due to air-pollution-related health issues. According to several published news reports, the extreme air pollution may be due to a combination of nearby agricultural burning after harvest, urban construction and solid-waste burning, as well as remnants of firecracker smoke and additional car emissions after the celebration of Diwali, the Hindu festival of lights, on October 30. The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite passed over the region on Saturday, Nov. 5, 2016, at around 11:05 a.m. local time. At left is an image acquired from MISR's vertical viewing camera. The Himalayas stretch across the northern portion of the image. This towering mountain range tends to concentrate pollution in the region immediately to the south, including New Delhi, by preventing pollutants from blowing northwards. New Delhi, whose location is indicated on the image, is under a patch of especially thick haze. At 6:00 a.m. local time on that date, the U.S. Mission India NowCast Air Quality Index for New Delhi was reported at 751, more than twice the threshold for hazardous air quality. At right, a map of aerosol optical depth is superimposed on the image. Optical depth is a quantitative measure of the abundance of aerosols (tiny particles in the atmosphere). Optical depths for the area around New Delhi have not been calculated because the haze is so thick that the algorithm has classified the area as a cloud. In the region immediately surrounding the thick haze, optical depths approach 1.0. An optical depth of 1.0 means that only about 37 percent of direct sunlight reaches the surface due to interactions with particles in the atmosphere. These data were acquired during Terra orbit 89805. Other MISR data are available through the NASA Langley Research Center; for more information, go to https://eosweb.larc.nasa.gov/project/misr/misr_table. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, California, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's Goddard Space Flight Center, Greenbelt, Maryland. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center, Hampton, Virginia. JPL is a division of the California Institute of Technology in Pasadena. http://photojournal.jpl.nasa.gov/catalog/PIA21100
An adaptive optics imaging system designed for clinical use.
Zhang, Jie; Yang, Qiang; Saito, Kenichi; Nozato, Koji; Williams, David R; Rossi, Ethan A
2015-06-01
Here we demonstrate a new imaging system that addresses several major problems limiting the clinical utility of conventional adaptive optics scanning light ophthalmoscopy (AOSLO), including its small field of view (FOV), reliance on patient fixation for targeting imaging, and substantial post-processing time. We previously showed an efficient image based eye tracking method for real-time optical stabilization and image registration in AOSLO. However, in patients with poor fixation, eye motion causes the FOV to drift substantially, causing this approach to fail. We solve that problem here by tracking eye motion at multiple spatial scales simultaneously by optically and electronically integrating a wide FOV SLO (WFSLO) with an AOSLO. This multi-scale approach, implemented with fast tip/tilt mirrors, has a large stabilization range of ± 5.6°. Our method consists of three stages implemented in parallel: 1) coarse optical stabilization driven by a WFSLO image, 2) fine optical stabilization driven by an AOSLO image, and 3) sub-pixel digital registration of the AOSLO image. We evaluated system performance in normal eyes and diseased eyes with poor fixation. Residual image motion with incremental compensation after each stage was: 1) ~2-3 arc minutes, (arcmin) 2) ~0.5-0.8 arcmin and, 3) ~0.05-0.07 arcmin, for normal eyes. Performance in eyes with poor fixation was: 1) ~3-5 arcmin, 2) ~0.7-1.1 arcmin and 3) ~0.07-0.14 arcmin. We demonstrate that this system is capable of reducing image motion by a factor of ~400, on average. This new optical design provides additional benefits for clinical imaging, including a steering subsystem for AOSLO that can be guided by the WFSLO to target specific regions of interest such as retinal pathology and real-time averaging of registered images to eliminate image post-processing.
Sleep quality and correlates of poor sleep in patients with rheumatoid arthritis.
Løppenthin, K; Esbensen, B A; Jennum, P; Østergaard, M; Tolver, A; Thomsen, T; Midtgaard, J
2015-12-01
The objective of this study is to examine sleep quality and correlates of poor sleep in patients with rheumatoid arthritis (RA). Five hundred patients with RA were recruited from a rheumatology outpatient clinic and included in this cross-sectional study. Sleep quality and disturbances were assessed using the Pittsburgh Sleep Quality Index (PSQI). Other instruments included the Multidimensional Fatigue Inventory, the Epworth Sleepiness Scale, and the Health Assessment Questionnaire. Disease activity was assessed according to disease activity score DAS28-CRP-based. Complete scores on PSQI were obtained from 384 patients (77 %). In those, the prevalence of poor sleep (PSQI >5) was 61 %, and the mean global PSQI score was 7.54 (SD 4.17). A linear association was found between poor sleep and mental fatigue, reduced activity related to fatigue, physical fatigue, and general fatigue. Mental fatigue and general fatigue were independently associated with sleep quality, sleep latency, sleep duration, sleep efficiency, and daytime dysfunction. However, in the linear multivariate analysis, only general fatigue 1.06 (95 % CI 1.03-1.09) and mental fatigue 1.03 (95 % CI 1.01-1.05) were found to be significant correlates for reporting poor sleep. This study shows that a majority of patients with RA experience poor sleep and that general fatigue and mental fatigue are associated with poor sleep.
Hansen, Anne Helen; Lian, Olaug S
2016-04-04
To test the association between self-rated health and self-rated degree of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), and CFS/ME patients' assessment of quality of primary care, specialist care and coordination of care. Cross-sectional study. Self-reported questionnaire data from women members of The Norwegian ME Association obtained in 2013. 431 women with CFS/ME aged 16-73 years. The participants' assessment of quality in primary care, specialist care and in coordination of care (good/very good or poor/very poor). Main explanatory variables: self-rated health and self-rated degree of CFS/ME. Quality of care was rated poor by 60.6% in primary care, by 47.7% in specialist care, and by 71.2% regarding coordination of care. Poorer self-rated health increased the probability of rating quality in primary care poor, particularly among women 40 years and over (OR 2.38, 95% CI 1.63 to 3.49), women with university education (OR 2.57, CI 1.68 to 3.94), and owing to less frequent general practitioner (GP) visits (OR 2.46, CI 1.60 to 3.78). Poorer self-rated health increased the probability of rating quality poor in specialist care (OR 1.38, CI 1.05 to 1.82), but not in coordination of care. A more severe CFS/ME was associated with a higher probability of rating quality in primary care poor (OR 0.61, CI 0.38 to 0.93). Frequent visitors and those with a long GP relationship were less likely to report primary care quality as poor. A large proportion of women with CFS/ME rated quality of care poor/very poor in primary care, specialist care and in coordination of care. The dissatisfaction was higher for primary care than for specialist care. Overall, poorer self-rated health and a more severe CFS/ME were associated with lower quality scores in primary and specialist care, but not in coordination of care. Healthcare services, as assessed by women with CFS/ME, do have a large potential for improvement. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Castro-Marrero, Jesús; Zaragozá, Maria C; González-Garcia, Sergio; Aliste, Luisa; Sáez-Francàs, Naia; Romero, Odile; Ferré, Alex; Fernández de Sevilla, Tomás; Alegre, José
2018-05-16
Non-restorative sleep is a hallmark symptom of chronic fatigue syndrome/myalgic encephalomyelitis. However, little is known about self-reported sleep disturbances in these subjects. This study aimed to assess the self-reported sleep quality and its impact on quality of life in a Spanish community-based chronic fatigue syndrome/myalgic encephalomyelitis cohort. A prospective cross-sectional cohort study was conducted in 1,455 Spanish chronic fatigue syndrome/myalgic encephalomyelitis patients. Sleep quality, fatigue, pain, functional capacity impairment, psychopathological status, anxiety/depression and health-related quality of life were assessed using validated subjective measures. The frequencies of muscular, cognitive, neurological, autonomic and immunological symptom clusters were above 80%. High scores were recorded for pain, fatigue, psychopathological status, anxiety/depression, and low scores for functional capacity and quality of life, all of which correlated significantly (all p < 0.01) with quality of sleep as measured by the Pittsburgh Sleep Quality Index. Multivariate regression analysis showed that after adjusting for age and gender, the pain intensity (odds ratio, 1.11; p <0.05), psychopathological status (odds ratio, 1.85; p < 0.001), fibromyalgia (odds ratio, 1.39; p < 0.05), severe autonomic dysfunction (odds ratio, 1.72; p < 0.05), poor functional capacity (odds ratio, 0.98; p < 0.05) and quality of life (odds ratio, 0.96; both p < 0.001) were significantly associated with poor sleep quality. These findings suggest that this large chronic fatigue syndrome/myalgic encephalomyelitis sample presents poor sleep quality, as assessed by the Pittsburgh Sleep Quality Index, and that this poor sleep quality is associated with many aspects of quality of life. © 2018 European Sleep Research Society.
Mind wandering, sleep quality, affect and chronotype: an exploratory study.
Carciofo, Richard; Du, Feng; Song, Nan; Zhang, Kan
2014-01-01
Poor sleep quality impairs cognition, including executive functions and concentration, but there has been little direct research on the relationships between sleep quality and mind wandering or daydreaming. Evening chronotype is associated with poor sleep quality, more mind wandering and more daydreaming; negative affect is also a mutual correlate. This exploratory study investigated how mind wandering and daydreaming are related to different aspects of sleep quality, and whether sleep quality influences the relationships between mind wandering/daydreaming and negative affect, and mind wandering/daydreaming and chronotype. Three surveys (Ns = 213; 190; 270) were completed with Chinese adults aged 18-50, including measures of sleep quality, daytime sleepiness, mind wandering, daydreaming, chronotype and affect (positive and negative). Higher frequencies of mind wandering and daydreaming were associated with poorer sleep quality, in particular with poor subjective sleep quality and increased sleep latency, night-time disturbance, daytime dysfunction and daytime sleepiness. Poor sleep quality was found to partially mediate the relationships between daydreaming and negative affect, and mind wandering and negative affect. Additionally, low positive affect and poor sleep quality, in conjunction, fully mediated the relationships between chronotype and mind wandering, and chronotype and daydreaming. The relationships between mind wandering/daydreaming and positive affect were also moderated by chronotype, being weaker in those with a morning preference. Finally, while daytime sleepiness was positively correlated with daydream frequency, it was negatively correlated with a measure of problem-solving daydreams, indicating that more refined distinctions between different forms of daydreaming or mind wandering are warranted. Overall, the evidence is suggestive of a bi-directional relationship between poor sleep quality and mind wandering/daydreaming, which may be important in attempts to deal with sleep problems and improve sleep quality. These findings and further research on this topic may also have implications for definitions and theories of mind wandering and daydreaming.
Mind Wandering, Sleep Quality, Affect and Chronotype: An Exploratory Study
Carciofo, Richard; Du, Feng; Song, Nan; Zhang, Kan
2014-01-01
Poor sleep quality impairs cognition, including executive functions and concentration, but there has been little direct research on the relationships between sleep quality and mind wandering or daydreaming. Evening chronotype is associated with poor sleep quality, more mind wandering and more daydreaming; negative affect is also a mutual correlate. This exploratory study investigated how mind wandering and daydreaming are related to different aspects of sleep quality, and whether sleep quality influences the relationships between mind wandering/daydreaming and negative affect, and mind wandering/daydreaming and chronotype. Three surveys (Ns = 213; 190; 270) were completed with Chinese adults aged 18–50, including measures of sleep quality, daytime sleepiness, mind wandering, daydreaming, chronotype and affect (positive and negative). Higher frequencies of mind wandering and daydreaming were associated with poorer sleep quality, in particular with poor subjective sleep quality and increased sleep latency, night-time disturbance, daytime dysfunction and daytime sleepiness. Poor sleep quality was found to partially mediate the relationships between daydreaming and negative affect, and mind wandering and negative affect. Additionally, low positive affect and poor sleep quality, in conjunction, fully mediated the relationships between chronotype and mind wandering, and chronotype and daydreaming. The relationships between mind wandering/daydreaming and positive affect were also moderated by chronotype, being weaker in those with a morning preference. Finally, while daytime sleepiness was positively correlated with daydream frequency, it was negatively correlated with a measure of problem-solving daydreams, indicating that more refined distinctions between different forms of daydreaming or mind wandering are warranted. Overall, the evidence is suggestive of a bi-directional relationship between poor sleep quality and mind wandering/daydreaming, which may be important in attempts to deal with sleep problems and improve sleep quality. These findings and further research on this topic may also have implications for definitions and theories of mind wandering and daydreaming. PMID:24609107
Advances in molecular dynamics simulation of ultra-precision machining of hard and brittle materials
NASA Astrophysics Data System (ADS)
Guo, Xiaoguang; Li, Qiang; Liu, Tao; Kang, Renke; Jin, Zhuji; Guo, Dongming
2017-03-01
Hard and brittle materials, such as silicon, SiC, and optical glasses, are widely used in aerospace, military, integrated circuit, and other fields because of their excellent physical and chemical properties. However, these materials display poor machinability because of their hard and brittle properties. Damages such as surface micro-crack and subsurface damage often occur during machining of hard and brittle materials. Ultra-precision machining is widely used in processing hard and brittle materials to obtain nanoscale machining quality. However, the theoretical mechanism underlying this method remains unclear. This paper provides a review of present research on the molecular dynamics simulation of ultra-precision machining of hard and brittle materials. The future trends in this field are also discussed.
Metals Electroprocessing in Molten Salts
NASA Technical Reports Server (NTRS)
Sadoway, D. R.
1985-01-01
The present study seeks to explain the poor quality of solid electrodeposits in molten salts through a consideration of the effects of fluid flow of the electrolyte. Transparent cells allow observation of electrolyte circulation by a laser schlieren optical technique during the electrodeposition of solid zinc from the molten salt electrolyte, ZnCl2 - LiCl-KCl. Experimental variables are current, density, electrolyte composition, and cell geometry. Based on the results of earlier electrodeposition studies as well as reports in the literature, these parameters are identified as having the primary influence on cell performance and deposit quality. Experiments are conducted to measure the fluid flow patterns and the electrochemical cell characteristics, and to correlate this information with the morphology of the solid electrodeposit produced. Specifically, cell voltage, cell current, characteristic time for dendrite evolution, and dendrite growth directions are noted. Their relationship to electrolyte flow patterns and the morphology of the resulting electrodeposit are derived. Results to date indicate that laser schlieren imaging is capable of revealing fluid flow patterns in a molten salt electrolyte.
Analysis of optical scheme for medium-range directed energy laser weapon system
NASA Astrophysics Data System (ADS)
Jabczyński, Jan K.; Kaśków, Mateusz; Gorajek, Łukasz; Kopczyński, Krzysztof
2017-10-01
The relations between range of operation and aperture of laser weapon system were investigated, taking into account diffraction and technical limitations as beam quality, accuracy of point tracking, technical quality of optical train, etc. As a result for the medium ranges of 1 - 2 km we restricted the analysis to apertures not wider than 150 mm and the optical system without adaptive optics. To choose the best laser beam shape, the minimization of aperture losses and thermooptical effects inside optics as well as the effective width of laser beam in far field should be taken into account. We have analyzed theoretically such a problem for the group of a few most interesting from that point of view profiles including for reference two limiting cases of Gaussian beam and `top hat' profile. We have found that the most promising is the SuperGaussian profile of index p = 2 for which the surfaces of beam shaper elements can be manufactured in the acceptable cost-effective way and beam quality does not decrease noticeably. Further, we have investigated the thermo-optic effects on the far field parameters of Gaussian and `top hat' beams to determine the influence of absorption in optical elements on beam quality degradation. The simplified formulae were derived for beam quality measures (parameter M2 and Strehl ratio) which enables to estimate the influence of absorption losses on degradation of beam quality.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Menapace, J A; Schaffers, K I; Bayramian, A J
2008-02-26
Advanced magnetorheological finishing (MRF) techniques have been applied to Ti:sapphire crystals to compensate for sub-millimeter lattice distortions that occur during the crystal growing process. Precise optical corrections are made by imprinting topographical structure onto the crystal surfaces to cancel out the effects of the lattice distortion in the transmitted wavefront. This novel technique significantly improves the optical quality for crystals of this type and sets the stage for increasing the availability of high-quality large-aperture sapphire and Ti:sapphire optics in critical applications.
Ng, Michael F Y; Stevenson, J Howard
2011-04-01
The aim of this study was to investigate the outcome and cost-effectiveness of good and poor quality photographs accompanying the electronic referrals for suspected skin malignancies. A retrospective study of 100 patients, divided into 2 groups, 50 with good quality photographs and 50 with poor quality photographs. Patients with no digital images, or who failed to attend, or patients with incomplete notes were excluded from the study. The treatment pathway, waiting times, and estimated cost between the 2 groups were compared. Good photographs were more likely to be treated at the 1-Stop Clinic (P = 0.05). Good images had a better positive predictive value than poor quality images (62.55% vs. 42.86%). Good quality images are more accurate than poor quality images in triaging of patients, and thus more effective in facilitating the treatment of malignant lesions timely. Good quality photographs allow a delayed appropriate treatment of benign lesions. This increases the safety for patients in a queue in a rationed health care system, and improves patient flow.
Method to improve optical parametric oscillator beam quality
Smith, Arlee V.; Alford, William J.; Bowers, Mark S.
2003-11-11
A method to improving optical parametric oscillator (OPO) beam quality having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.
The maladies of water and war: addressing poor water quality in Iraq.
Zolnikov, Tara Rava
2013-06-01
Water is essential in providing nutrients, but contaminated water contributes to poor population health. Water quality and availability can change in unstructured situations, such as war. To develop a practical strategy to address poor water quality resulting from intermittent wars in Iraq, I reviewed information from academic sources regarding waterborne diseases, conflict and war, water quality treatment, and malnutrition. The prevalence of disease was high in impoverished, malnourished populations exposed to contaminated water sources. The data aided in developing a strategy to improve water quality in Iraq, which encompasses remineralized water from desalination plants, health care reform, monitoring and evaluation systems, and educational public health interventions.
ERIC Educational Resources Information Center
Valentino, Rachel
2018-01-01
Publicly funded pre-K is often touted as a means to narrow achievement gaps, but this goal is less likely to be achieved if poor and/or minority children do not, at a minimum, attend equal quality pre-K as their non-poor, non-minority peers. In this paper, I find large "quality gaps" in public pre-K between poor, minority students and…
Testing vision with angular and radial multifocal designs using Adaptive Optics.
Vinas, Maria; Dorronsoro, Carlos; Gonzalez, Veronica; Cortes, Daniel; Radhakrishnan, Aiswaryah; Marcos, Susana
2017-03-01
Multifocal vision corrections are increasingly used solutions for presbyopia. In the current study we have evaluated, optically and psychophysically, the quality provided by multizone radial and angular segmented phase designs. Optical and relative visual quality were evaluated using 8 subjects, testing 6 phase designs. Optical quality was evaluated by means of Visual Strehl-based-metrics (VS). The relative visual quality across designs was obtained through a psychophysical paradigm in which images viewed through 210 pairs of phase patterns were perceptually judged. A custom-developed Adaptive Optics (AO) system, including a Hartmann-Shack sensor and an electromagnetic deformable mirror, to measure and correct the eye's aberrations, and a phase-only reflective Spatial Light Modulator, to simulate the phase designs, was developed for this study. The multizone segmented phase designs had 2-4 zones of progressive power (0 to +3D) in either radial or angular distributions. The response of an "ideal observer" purely responding on optical grounds to the same psychophysical test performed on subjects was calculated from the VS curves, and compared with the relative visual quality results. Optical and psychophysical pattern-comparison tests showed that while 2-zone segmented designs (angular & radial) provided better performance for far and near vision, 3- and 4-zone segmented angular designs performed better for intermediate vision. AO-correction of natural aberrations of the subjects modified the response for the different subjects but general trends remained. The differences in perceived quality across the different multifocal patterns are, in a large extent, explained by optical factors. AO is an excellent tool to simulate multifocal refractions before they are manufactured or delivered to the patient, and to assess the effects of the native optics to their performance. Copyright © 2016 Elsevier Ltd. All rights reserved.
Coordinating standards and applications for optical water quality sensor networks
Bergamaschi, B.; Pellerin, B.
2011-01-01
Joint USGS-CUAHSI Workshop: In Situ Optical Water Quality Sensor Networks; Shepherdstown, West Virginia, 8-10 June 2011; Advanced in situ optical water quality sensors and new techniques for data analysis hold enormous promise for advancing scientific understanding of aquatic systems through measurements of important biogeochemical parameters at the time scales over which they vary. High-frequency and real-time water quality data also provide the opportunity for early warning of water quality deterioration, trend detection, and science-based decision support. However, developing networks of optical sensors in freshwater systems that report reliable and comparable data across and between sites remains a challenge to the research and monitoring community. To address this, the U.S. Geological Survey (USGS) and the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI), convened a 3-day workshop to explore ways to coordinate development of standards and applications for optical sensors, as well as handling, storage, and analysis of the continuous data they produce.
NASA Astrophysics Data System (ADS)
Goldberg, Kenneth A.; Naulleau, Patrick P.; Bokor, Jeffrey; Chapman, Henry N.
2002-07-01
As the quality of optical systems for extreme ultraviolet lithography improves, high-accuracy wavefront metrology for alignment and qualification becomes ever more important. To enable the development of diffraction-limited EUV projection optics, visible-light and EUV interferometries must work in close collaboration. We present a detailed comparison of EUV and visible-light wavefront measurements performed across the field of view of a lithographic-quality EUV projection optical system designed for use in the Engineering Test Stand developed by the Virtual National Laboratory and the EUV Limited Liability Company. The comparisons reveal that the present level of RMS agreement lies in the 0.3-0.4-nm range. Astigmatism is the most significant aberration component for the alignment of this optical system; it is also the dominant term in the discrepancy, and the aberration with the highest measurement uncertainty. With EUV optical systems requiring total wavefront quality in the (lambda) EUV/50 range, and even higher surface-figure quality for the individual mirror elements, improved accuracy through future comparisons, and additional studies, are required.
Imaging Pancreatic Cancer Using Bioconjugated InP Quantum Dots
Yong, Ken-Tye; Ding, Hong; Roy, Indrajit; Law, Wing-Cheung; Bergey, Earl J.; Maitra, Anirban; Prasad, Paras N.
2009-01-01
In this paper, we report the successful use of non-cadmium based quantum dots (QDs) as highly efficient and non-toxic optical probes for imaging live pancreatic cancer cells. Indium phosphide (core)-zinc sulphide (shell), or InP/ZnS, QDs with high quality and bright luminescence were prepared by a hot colloidal synthesis method in non-aqueous media. The surfaces of these QDs were then functionalized with mercaptosuccinic acid to make them highly dispersible in aqueous media. Further bioconjugation with pancreatic cancer specific monoclonal antibodies, such as anti-claudin 4 and anti-prostate stem cell antigen (anti-PSCA), to the functionalized InP/ZnS QDs, allowed specific in vitro targeting of pancreatic cancer cell lines (both immortalized and low passage ones). The receptor mediated delivery of the bioconjugates was further confirmed by the observation of poor in vitro targeting in non-pancreatic cancer based cell lines which are negative for the claudin-4-receptor. These observations suggest the immense potential of InP/ZnS QDs as non-cadmium based safe and efficient optical imaging nanoprobes in diagnostic imaging, particularly for early detection of cancer. PMID:19243145
Imaging pancreatic cancer using bioconjugated InP quantum dots.
Yong, Ken-Tye; Ding, Hong; Roy, Indrajit; Law, Wing-Cheung; Bergey, Earl J; Maitra, Anirban; Prasad, Paras N
2009-03-24
In this paper, we report the successful use of non-cadmium-based quantum dots (QDs) as highly efficient and nontoxic optical probes for imaging live pancreatic cancer cells. Indium phosphide (core)-zinc sulfide (shell), or InP/ZnS, QDs with high quality and bright luminescence were prepared by a hot colloidal synthesis method in nonaqueous media. The surfaces of these QDs were then functionalized with mercaptosuccinic acid to make them highly dispersible in aqueous media. Further bioconjugation with pancreatic cancer specific monoclonal antibodies, such as anticlaudin 4 and antiprostate stem cell antigen (anti-PSCA), to the functionalized InP/ZnS QDs, allowed specific in vitro targeting of pancreatic cancer cell lines (both immortalized and low passage ones). The receptor-mediated delivery of the bioconjugates was further confirmed by the observation of poor in vitro targeting in nonpancreatic cancer based cell lines which are negative for the claudin-4-receptor. These observations suggest the immense potential of InP/ZnS QDs as non-cadmium-based safe and efficient optical imaging nanoprobes in diagnostic imaging, particularly for early detection of cancer.
MERIS Retrieval of Water Quality Components in the Turbid Albemarle-Pamlico Sound Estuary, USA
Biological, geophysical and optical field observations carried out in the Neuse River Estuary, North Carolina, USA were used to develop a semi-empirical optical algorithm for assessing inherent optical properties associated with water quality components (WQCs). Three wavelengths ...
Sleep quality in long haul truck drivers: A study on Iranian national data.
Sadeghniiat-Haghighi, Khosro; Yazdi, Zohreh; Kazemifar, Amir-Mohammad
2016-08-01
Iran has a high rate of road traffic accidents. Poor quality of sleep brings about loss of attention, which is an important cause of road traffic accidents particularly in monotonous roads. The causes of poor quality of sleep in occupational drivers are multifactorial. The objective of the present study was to assess the prevalence of poor sleep quality among occupational drivers with rotating work schedules and analyze its different risk factors. 2200 professional long-haul truck drivers who had been referred to the Occupational Health Clinic for routine education course were invited. We obtained data from eight provinces from various parts of Iran during 2012-2013. Data were collected using a questionnaire including questions about demographic and job characteristics. Pittsburg Sleep Quality Index (PSQI) was used to assess drivers' sleep quality. Mean working (driving) time was (9.3±2.5) hours daily and (55.5 ± 18.29) hours weekly. About 23.5% of the drivers reported history of smoking, 14.5% had low job satisfaction and 60% had irregular work schedule. 16.4% of drivers had an accidents leading to injury during the past five years. The mean PSQI score was 4.2 ± 2.7; 54% had a PSQI>5 (poor quality of sleep). Multivariate logistic regression showed that smoking, job satisfaction, history of accidents, shift work and work hours per day were the most important risk factors for poor sleep quality. Results obtained from the current study showed a high prevalence of poor quality of sleep among professional drivers. It warrants more attention to this significant problem using some measures to improve working conditions in professional drivers, as well as health promotion interventions.
Age and gender effects on the prevalence of poor sleep quality in the adult population.
Madrid-Valero, Juan J; Martínez-Selva, José M; Ribeiro do Couto, Bruno; Sánchez-Romera, Juan F; Ordoñana, Juan R
Sleep quality has a significant impact on health and quality of life and is affected, among other factors, by age and sex. However, the prevalence of problems in this area in the general population is not well known. Therefore, our objective was to study the prevalence and main characteristics of sleep quality in an adult population sample. 2,144 subjects aged between 43 and 71 years belonging to the Murcia (Spain) Twin Registry. Sleep quality was measured by self-report through the Pittsburgh Sleep Quality Index (PSQI). Logistic regression models were used to analyse the results. The prevalence of poor sleep quality stands at 38.2%. Univariate logistic regression analyses showed that women were almost twice as likely as men (OR: 1.88; 95% confidence interval [95%CI]: 1.54 to 2.28) to have poor quality of sleep. Age was directly and significantly associated with a low quality of sleep (OR: 1.05; 95%CI: 1.03 to 1.06). The prevalence of poor sleep quality is high among adults, especially women. There is a direct relationship between age and deterioration in the quality of sleep. This relationship also appears to be more consistent in women. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.
Peltzer, Karl; Phaswana-Mafuya, Nancy
2017-07-19
This study aims to estimate the association between visual impairment and low vision and sleep duration and poor sleep quality in a national sample of older adults in South Africa. A national population-based cross-sectional Study of Global Ageing and Adults Health (SAGE) wave 1 was conducted in 2008 with a sample of 3840 individuals aged 50 years or older in South Africa. The interviewer-administered questionnaire assessed socio-demographic characteristics, health variables, sleep duration, quality, visual impairment, and vision. Results indicate that 10.0% of the sample reported short sleep duration (≤5 h), 46.6% long sleep (≥9 h), 9.3% poor sleep quality, 8.4% self-reported and visual impairment (near and/or far vision); and 43.2% measured low vision (near and/or far vision) (0.01-0.25 decimal) and 7.5% low vision (0.01-0.125 decimal). In fully adjusted logistic regression models, self-reported visual impairment was associated with short sleep duration and poor sleep quality, separately and together. Low vision was only associated with long sleep duration and poor sleep quality in unadjusted models. Self-reported visual impairment was related to both short sleep duration and poor sleep quality. Population data on sleep patterns may want to include visual impairment measures.
Yarbrough, Wendell G; Sewell, Andrew; Tickle, Erin; Rhinehardt, Eric; Harkleroad, Rod; Bennett, Marc; Johnson, Deborah; Wen, Li; Pfeiffer, Matthew; Benegas, Manny; Morath, Julie
2014-12-01
Hospital leaders lack tools to determine the financial impact of poor patient outcomes and adverse events. To provide health-care leaders with decision support for investments to improve care, we created a tool, the Healthcare Quality Calculator (HQCal), which uses institution-specific financial data to calculate impact of poor patient outcomes or quality improvement on present and future margin. Excel and Web-based versions of the HQCal were based on a cohort study framework and created with modular components including major drivers of cost and reimbursement. The Healthcare Quality Calculator (HQCal) compares payment, cost, and profit/loss for patients with and without poor outcomes or quality issues. Cost and payment information for groups with and without quality issues are used by the HQCal to calculate profit or loss. Importantly, institution-specific payment and cost data are used to calculate financial impact and attributable cost associated with poor patient outcomes, adverse events, or quality issues. Because future cost and reimbursement changes can be forecast, the HQCal incorporates a forward-looking component. The flexibility of the HQCal was demonstrated using surgical site infections after abdominal surgery and postoperative surgical airway complications. The Healthcare Quality Calculator determines financial impact of poor patient outcomes and the benefit of initiatives to improve quality. The calculator can identify quality issues that would provide the largest financial benefit if improved; however, it cannot identify specific interventions. The calculator provides a tool to improve transparency regarding both short- and long-term financial consequences of funding, or failing to fund, initiatives to close gaps in quality or improve patient outcomes.
Lin, Pei-Chen; Chen, Chung-Hey; Pan, Shung-Mei; Pan, Chih-Hong; Chen, Chiou-Jong; Chen, Yao-Mei; Hung, Hsin-Chia; Wu, Ming-Tsang
2012-11-01
To investigate the effects of shift work schedules on sleep quality and mental health in female nurses in south Taiwan. This study recruited 1,360 female registered nurses in the Kaohsiung area for the first survey, and among them, 769 nurses had a rotation shift schedule. Among the 769 rotation shift work nurses, 407 completed another second survey 6-10 months later. Data collection included demographic variables, work status, shift work schedule, sleep quality (Pittsburgh Sleep Quality Index), and mental health (Chinese Health Questionnaire-12). Nurses on rotation shift had the poor sleep quality and mental health compared to nurses on day shift. The nurses on rotation shift had a relatively higher OR of reporting poor sleep quality and poor mental health (OR, 2.26; 95% CI, 1.57-3.28; and OR, 1.91; 95% CI, 1.39-2.63, respectively). Additionally, rotation shift nurses who had ≥2 days off after their most recent night shifts showed significantly improved sleep quality and mental health (PSQI decreased of 1.23 and CHQ-12 decreased of 0.86, respectively). Comparison of sleep quality between the first and second surveys showed aggravated sleep quality only in nurses who had an increased frequency of night shifts. Female nurses who have a rotation shift work schedule tend to experience poor sleep quality and mental health, but their sleep quality and mental health improve if they have ≥2 days off after their most recent night shifts. This empirical information is useful for optimizing work schedules for nurses.
Objective measurement of the optical image quality in the human eye
NASA Astrophysics Data System (ADS)
Navarro, Rafael M.
2001-05-01
This communication reviews some recent studies on the optical performance of the human eye. Although the retinal image cannot be recorded directly, different objective methods have been developed, which permit to determine optical quality parameters, such as the Point Spread Function (PSF), the Modulation Transfer Function (MTF), the geometrical ray aberrations or the wavefront distortions, in the living human eye. These methods have been applied in both basic and applied research. This includes the measurement of the optical performance of the eye across visual field, the optical quality of eyes with intraocular lens implants, the aberrations induced by LASIK refractive surgery, or the manufacture of customized phase plates to compensate the wavefront aberration in the eye.
The prevalence and association of stress with sleep quality among medical students.
Almojali, Abdullah I; Almalki, Sami A; Alothman, Ali S; Masuadi, Emad M; Alaqeel, Meshal K
2017-09-01
Medical students tend to reduce their sleep, in an effort to adjust and cope with their workload and stressful environment. This study estimated the prevalence of and the relationship between poor sleep quality and stress among medical students. This cross-sectional study was conducted using a stratified random sample of male and female medical students in King Saud bin Abdulaziz University for Health Sciences in Riyadh, Saudi Arabia. A self-administered questionnaire was distributed to assess sleep quality using the Pittsburgh Sleep Quality Index, and the stress level by using the Kessler Psychological Distress Scale. A high prevalence of poor sleep quality (76%) and stress (53%) were found, with a statistically significant association (p<0.001). Logistic regression indicated that students who are not suffering from stress are less likely to have poor sleep quality (OR=0.28, p<0.001), and the risk of having poor sleep quality is almost four times higher in students whose cumulative grade point average (GPA) is less than 4.25 (OR=3.83, p=0.01). The study documents a statistically significant association between stress and poor sleep quality. A recommendation for the management of medical college is to establish academic counseling centers focusing in promoting good sleep hygiene and strengthening students' study skills and coping with their stressful environment. Copyright © 2017 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.
Pérez Bartolomé, Francisco; Martínez de la Casa, Jose María; Camacho Bosca, Irene; Sáenz-Francés, Federico; Aguilar Munoa, Soledad; Martín Juan, Alberto; Garcia-Feijoo, Julian
2018-01-01
To examine interrelations between corneal biomechanics, ocular biometric variables and optic disc size (ODS), lamina cribosa depth (LCD) or thickness (LCT) in a healthy population. In a cross-sectional case-control study, the following measurements were made in 81 eyes of 81 participants: axial length, anterior chamber depth, lens thickness, and central corneal thickness using the optical biometer Lenstar LS900; and corneal hysteresis (CH), corneal resistance factor (CRF), Goldman-correlated intraocular pressure (IOPg), and corneal-compensated IOP (IOPcc) using the Ocular Response Analyzer. Serial horizontal enhanced depth imaging optical coherence tomography (EDI OCT) B-scans of the optic nerve head were obtained in each participant. Mean ODS, mean LCD, and mean LCT were measured in 11 equally spaced horizontal B-scans, excluding the LC insertion area under Bruch's membrane and scleral rim. LCD was measured in 74 of 81 eyes (91.36%); LCT in 60/81 (75.3%); ODS in 81/81 (100%). CRF was poorly, but significantly, correlated with LCT (Pearson's R = 0.264; P = 0.045). IOPcc, IOPg, CH, and ocular biometrics variables were poorly (non-significantly) correlated with LCD, LCT, and ODS. CRF was poorly but directly correlated with LCT. No association was detected between CH or ocular biometric variables and ODS, LCD, or LCT.
Poor housing quality: Prevalence and health effects.
Baker, Emma; Lester, Laurence H; Bentley, Rebecca; Beer, Andrew
2016-01-01
Housing is a central component of productive, healthy, and meaningful lives, and a principle social determinant of health and well-being. Surprisingly, though, evidence on the ways that housing influences health in Australia is poorly developed. This stems largely from the fact that the majority of the population are accommodated in good quality housing. The dominance of a "good housing paradigm" means that households living in poor quality and unhealthy housing are doubly disadvantaged-by the quality of their housing and because policy makers in Australia do not acknowledge the health effects of housing. In this article, we examine the relationship between health outcomes and quality of housing. We base our analysis on data from the Household Income and Labour Dynamics in Australia (HILDA) survey, a panel dataset that is representative across Australia. We find a sizeable, policy-important, and to date under-acknowledged cohort of Australians whose health is influenced by poor-condition dwellings.
Sleep hygiene education: efficacy on sleep quality in working women.
Chen, Pao-Hui; Kuo, Hung-Yu; Chueh, Ke-Hsin
2010-12-01
Although sleep hygiene education represents a promising approach for patients with poor sleep quality, little research has been devoted in understanding the sleep hygiene behavior and knowledge of working women. The purpose of this study was to investigate the efficacy of a short-term sleep hygiene education program on working women with poor sleep quality. This pilot study was a prospective and an exploratory intervention study. The intervention was tested on 37 selected working women with poor sleep quality in the community. The Pittsburgh Sleep Quality Index (score > 5) was used to identify working women with poor sleep quality. After a pretest to assess sleep quality, researchers implemented a 5-week sleep hygiene education program that addressed good sleep environments/habits, emotional stress, the influence of diet/alcohol/tobacco on sleep, exercise, and alternative therapies. Tests administered midway through the program and after program completion provided the data used to analyze effective sleep quality changes. Results showed sleep hygiene education to improve participant sleep quality significantly (p < .001). The sleep quality of all participants improved over both the 3- and the 5-week education program. The six components of the Pittsburgh Sleep Quality Index (i.e., subjective sleep quality, sleep latency, sleep duration, sleep disturbances, use of sleeping medication, and daytime dysfunction) also improved. A brief and effective sleep hygiene education program delivered by a nurse can improve sleep quality in working women with sleeping problems.
Davison, Karen M.; Gondara, Lovedeep; Kaplan, Bonnie J.
2017-01-01
Background: To address nutrition-related population mental health data gaps, we examined relationships among food insecurity, diet quality, and perceived mental health. Methods: Stratified and logistic regression analyses of respondents aged 19–70 years from the Canadian Community Health Survey, Cycle 2.2 were conducted (n = 15,546). Measures included the Household Food Security Survey Module, diet quality (i.e., comparisons to the Dietary Reference Intakes, Healthy Eating Index), perceived mental health (poor versus good), sociodemographics, and smoking. Results: In this sample, 6.9% were food insecure and 4.5% reported poor mental health. Stratified analysis of food security and mental health status by age/gender found associations for poor diet quality, protein, fat, fibre, and several micronutrients (p-values < 0.05); those who were food insecure tended to have higher suboptimal intakes (p-values < 0.05). After adjustment for covariates, associations in relation to mental health emerged for food insecurity (OR = 1.60, 95% CI 1.45–1.71), poor diet quality (1.61, 95% CI 1.34–1.81), and suboptimal intakes of folate (OR = 1.58, 95% CI 1.17–1.90) and iron (OR = 1.45, 95% CI 1.23–1.88). Conclusions: Population approaches that improve food security and intakes of high quality diets may protect people from poor mental health. PMID:28335418
Davison, Karen M; Gondara, Lovedeep; Kaplan, Bonnie J
2017-03-14
To address nutrition-related population mental health data gaps, we examined relationships among food insecurity, diet quality, and perceived mental health. Stratified and logistic regression analyses of respondents aged 19-70 years from the Canadian Community Health Survey, Cycle 2.2 were conducted ( n = 15,546). Measures included the Household Food Security Survey Module, diet quality (i.e., comparisons to the Dietary Reference Intakes , Healthy Eating Index), perceived mental health (poor versus good), sociodemographics, and smoking. In this sample, 6.9% were food insecure and 4.5% reported poor mental health. Stratified analysis of food security and mental health status by age/gender found associations for poor diet quality, protein, fat, fibre, and several micronutrients ( p -values < 0.05); those who were food insecure tended to have higher suboptimal intakes ( p -values < 0.05). After adjustment for covariates, associations in relation to mental health emerged for food insecurity (OR = 1.60, 95% CI 1.45-1.71), poor diet quality (1.61, 95% CI 1.34-1.81), and suboptimal intakes of folate (OR = 1.58, 95% CI 1.17-1.90) and iron (OR = 1.45, 95% CI 1.23-1.88). Population approaches that improve food security and intakes of high quality diets may protect people from poor mental health.
Hetzel, Manuel W; Page-Sharp, Madhu; Bala, Nancy; Pulford, Justin; Betuela, Inoni; Davis, Timothy M E; Lavu, Evelyn K
2014-01-01
Poor-quality life-saving medicines are a major public health threat, particularly in settings with a weak regulatory environment. Insufficient amounts of active pharmaceutical ingredients (API) endanger patient safety and may contribute to the development of drug resistance. In the case of malaria, concerns relate to implications for the efficacy of artemisinin-based combination therapies (ACT). In Papua New Guinea (PNG), Plasmodium falciparum and P. vivax are both endemic and health facilities are the main source of treatment. ACT has been introduced as first-line treatment but other drugs, such as primaquine for the treatment of P. vivax hypnozoites, are widely available. This study investigated the quality of antimalarial drugs and selected antibiotics at all levels of the health facility supply chain in PNG. Medicines were obtained from randomly sampled health facilities and selected warehouses and hospitals across PNG and analysed for API content using validated high performance liquid chromatography (HPLC). Of 360 tablet/capsule samples from 60 providers, 9.7% (95% CI 6.9, 13.3) contained less, and 0.6% more, API than pharmacopoeial reference ranges, including 29/37 (78.4%) primaquine, 3/70 (4.3%) amodiaquine, and one sample each of quinine, artemether, sulphadoxine-pyrimethamine and amoxicillin. According to the package label, 86.5% of poor-quality samples originated from India. Poor-quality medicines were found in 48.3% of providers at all levels of the supply chain. Drug quality was unrelated to storage conditions. This study documents the presence of poor-quality medicines, particularly primaquine, throughout PNG. Primaquine is the only available transmission-blocking antimalarial, likely to become important to prevent the spread of artemisinin-resistant P. falciparum and eliminating P. vivax hypnozoites. The availability of poor-quality medicines reflects the lack of adequate quality control and regulatory mechanisms. Measures to stop the availability of poor-quality medicines should include limiting procurement to WHO prequalified products and implementing routine quality testing.
Hetzel, Manuel W.; Page-Sharp, Madhu; Bala, Nancy; Pulford, Justin; Betuela, Inoni; Davis, Timothy M. E.; Lavu, Evelyn K.
2014-01-01
Background Poor-quality life-saving medicines are a major public health threat, particularly in settings with a weak regulatory environment. Insufficient amounts of active pharmaceutical ingredients (API) endanger patient safety and may contribute to the development of drug resistance. In the case of malaria, concerns relate to implications for the efficacy of artemisinin-based combination therapies (ACT). In Papua New Guinea (PNG), Plasmodium falciparum and P. vivax are both endemic and health facilities are the main source of treatment. ACT has been introduced as first-line treatment but other drugs, such as primaquine for the treatment of P. vivax hypnozoites, are widely available. This study investigated the quality of antimalarial drugs and selected antibiotics at all levels of the health facility supply chain in PNG. Methods and Findings Medicines were obtained from randomly sampled health facilities and selected warehouses and hospitals across PNG and analysed for API content using validated high performance liquid chromatography (HPLC). Of 360 tablet/capsule samples from 60 providers, 9.7% (95% CI 6.9, 13.3) contained less, and 0.6% more, API than pharmacopoeial reference ranges, including 29/37 (78.4%) primaquine, 3/70 (4.3%) amodiaquine, and one sample each of quinine, artemether, sulphadoxine-pyrimethamine and amoxicillin. According to the package label, 86.5% of poor-quality samples originated from India. Poor-quality medicines were found in 48.3% of providers at all levels of the supply chain. Drug quality was unrelated to storage conditions. Conclusions This study documents the presence of poor-quality medicines, particularly primaquine, throughout PNG. Primaquine is the only available transmission-blocking antimalarial, likely to become important to prevent the spread of artemisinin-resistant P. falciparum and eliminating P. vivax hypnozoites. The availability of poor-quality medicines reflects the lack of adequate quality control and regulatory mechanisms. Measures to stop the availability of poor-quality medicines should include limiting procurement to WHO prequalified products and implementing routine quality testing. PMID:24828338
Duncan, Mitch J.; Kline, Christopher E.; Vandelanotte, Corneel; Sargent, Charli; Rogers, Naomi L.; Di Milia, Lee
2014-01-01
Background The independent and combined influence of smoking, alcohol consumption, physical activity, diet, sitting time, and sleep duration and quality on health status is not routinely examined. This study investigates the relationships between these lifestyle behaviors, independently and in combination, and health-related quality of life (HRQOL). Methods Adult members of the 10,000 Steps project (n = 159,699) were invited to participate in an online survey in November-December 2011. Participant socio-demographics, lifestyle behaviors, and HRQOL (poor self-rated health; frequent unhealthy days) were assessed by self-report. The combined influence of poor lifestyle behaviors were examined, independently and also as part of two lifestyle behavior indices, one excluding sleep quality (Index 1) and one including sleep quality (Index 2). Adjusted Cox proportional hazard models were used to examine relationships between lifestyle behaviors and HRQOL. Results A total of 10,478 participants provided complete data for the current study. For Index 1, the Prevalence Ratio (p value) of poor self-rated health was 1.54 (p = 0.001), 2.07 (p≤0.001), 3.00 (p≤0.001), 3.61 (p≤0.001) and 3.89 (p≤0.001) for people reporting two, three, four, five and six poor lifestyle behaviors, compared to people with 0–1 poor lifestyle behaviors. For Index 2, the Prevalence Ratio (p value) of poor self-rated health was 2.26 (p = 0.007), 3.29 (p≤0.001), 4.68 (p≤0.001), 6.48 (p≤0.001), 7.91 (p≤0.001) and 8.55 (p≤0.001) for people reporting two, three, four, five, six and seven poor lifestyle behaviors, compared to people with 0–1 poor lifestyle behaviors. Associations between the combined lifestyle behavior index and frequent unhealthy days were statistically significant and similar to those observed for poor self-rated health. Conclusions Engaging in a greater number of poor lifestyle behaviors was associated with a higher prevalence of poor HRQOL. This association was exacerbated when sleep quality was included in the index. PMID:24714564
Duncan, Mitch J; Kline, Christopher E; Vandelanotte, Corneel; Sargent, Charli; Rogers, Naomi L; Di Milia, Lee
2014-01-01
The independent and combined influence of smoking, alcohol consumption, physical activity, diet, sitting time, and sleep duration and quality on health status is not routinely examined. This study investigates the relationships between these lifestyle behaviors, independently and in combination, and health-related quality of life (HRQOL). Adult members of the 10,000 Steps project (n = 159,699) were invited to participate in an online survey in November-December 2011. Participant socio-demographics, lifestyle behaviors, and HRQOL (poor self-rated health; frequent unhealthy days) were assessed by self-report. The combined influence of poor lifestyle behaviors were examined, independently and also as part of two lifestyle behavior indices, one excluding sleep quality (Index 1) and one including sleep quality (Index 2). Adjusted Cox proportional hazard models were used to examine relationships between lifestyle behaviors and HRQOL. A total of 10,478 participants provided complete data for the current study. For Index 1, the Prevalence Ratio (p value) of poor self-rated health was 1.54 (p = 0.001), 2.07 (p≤0.001), 3.00 (p≤0.001), 3.61 (p≤0.001) and 3.89 (p≤0.001) for people reporting two, three, four, five and six poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. For Index 2, the Prevalence Ratio (p value) of poor self-rated health was 2.26 (p = 0.007), 3.29 (p≤0.001), 4.68 (p≤0.001), 6.48 (p≤0.001), 7.91 (p≤0.001) and 8.55 (p≤0.001) for people reporting two, three, four, five, six and seven poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. Associations between the combined lifestyle behavior index and frequent unhealthy days were statistically significant and similar to those observed for poor self-rated health. Engaging in a greater number of poor lifestyle behaviors was associated with a higher prevalence of poor HRQOL. This association was exacerbated when sleep quality was included in the index.
2014-01-01
Background Poor quality medicines threaten the lives of millions of patients and are alarmingly common in many parts of the world. Nevertheless, the global extent of the problem remains unknown. Accurate estimates of the epidemiology of poor quality medicines are sparse and are influenced by sampling methodology and diverse chemical analysis techniques. In order to understand the existing data, the Antimalarial Quality Scientific Group at WWARN built a comprehensive, open-access, global database and linked Antimalarial Quality Surveyor, an online visualization tool. Analysis of the database is described here, the limitations of the studies and data reported, and their public health implications discussed. Methods The database collates customized summaries of 251 published anti-malarial quality reports in English, French and Spanish by time and location since 1946. It also includes information on assays to determine quality, sampling and medicine regulation. Results No publicly available reports for 60.6% (63) of the 104 malaria-endemic countries were found. Out of 9,348 anti-malarials sampled, 30.1% (2,813) failed chemical/packaging quality tests with 39.3% classified as falsified, 2.3% as substandard and 58.3% as poor quality without evidence available to categorize them as either substandard or falsified. Only 32.3% of the reports explicitly described their definitions of medicine quality and just 9.1% (855) of the samples collected in 4.6% (six) surveys were conducted using random sampling techniques. Packaging analysis was only described in 21.5% of publications and up to twenty wrong active ingredients were found in falsified anti-malarials. Conclusions There are severe neglected problems with anti-malarial quality but there are important caveats to accurately estimate the prevalence and distribution of poor quality anti-malarials. The lack of reports in many malaria-endemic areas, inadequate sampling techniques and inadequate chemical analytical methods and instrumental procedures emphasizes the need to interpret medicine quality results with caution. The available evidence demonstrates the need for more investment to improve both sampling and analytical methodology and to achieve consensus in defining different types of poor quality medicines. PMID:24712972
A micro-vibration generated method for testing the imaging quality on ground of space remote sensing
NASA Astrophysics Data System (ADS)
Gu, Yingying; Wang, Li; Wu, Qingwen
2018-03-01
In this paper, a novel method is proposed, which can simulate satellite platform micro-vibration and test the impact of satellite micro-vibration on imaging quality of space optical remote sensor on ground. The method can generate micro-vibration of satellite platform in orbit from vibrational degrees of freedom, spectrum, magnitude, and coupling path. Experiment results show that the relative error of acceleration control is within 7%, in frequencies from 7Hz to 40Hz. Utilizing this method, the system level test about the micro-vibration impact on imaging quality of space optical remote sensor can be realized. This method will have an important applications in testing micro-vibration tolerance margin of optical remote sensor, verifying vibration isolation and suppression performance of optical remote sensor, exploring the principle of micro-vibration impact on imaging quality of optical remote sensor.
Modeling of the laser beam shape for high-power applications
NASA Astrophysics Data System (ADS)
Jabczyński, Jan K.; Kaskow, Mateusz; Gorajek, Lukasz; Kopczyński, Krzysztof; Zendzian, Waldemar
2018-04-01
Aperture losses and thermo-optic effects (TOE) inside optics as well as the effective beam width in far field should be taken into account in the analysis of the most appropriate laser beam profile for high-power applications. We have theoretically analyzed such a problem for a group of super-Gaussian beams taking first only diffraction limitations. Furthermore, we have investigated TOE on far-field parameters of such beams to determine the influence of absorption in optical elements on beam quality degradation. The best compromise gives the super-Gaussian profile of index p = 5, for which beam quality does not decrease noticeably and the thermo-optic higher order aberrations are compensated. The simplified formulas were derived for beam quality metrics (parameter M2 and Strehl ratio), which enable estimation of the influence of heat deposited in optics on degradation of beam quality. The method of dynamic compensation of such effect was proposed.
Poor sleep quality is associated with a negative cognitive bias and decreased sustained attention.
Gobin, Christina M; Banks, Jonathan B; Fins, Ana I; Tartar, Jaime L
2015-10-01
Poor sleep quality has been demonstrated to diminish cognitive performance, impair psychosocial functioning and alter the perception of stress. At present, however, there is little understanding of how sleep quality affects emotion processing. The aim of the present study was to determine the extent to which sleep quality, measured through the Pittsburg Sleep Quality Index, influences affective symptoms as well as the interaction between stress and performance on an emotional memory test and sustained attention task. To that end, 154 undergraduate students (mean age: 21.27 years, standard deviation = 4.03) completed a series of measures, including the Pittsburg Sleep Quality Index, the Sustained Attention to Response Task, an emotion picture recognition task and affective symptom questionnaires following either a control or physical stress manipulation, the cold pressor test. As sleep quality and psychosocial functioning differ among chronotypes, we also included chronotype and time of day as variables of interest to ensure that the effects of sleep quality on the emotional and non-emotional tasks were not attributed to these related factors. We found that poor sleep quality is related to greater depressive symptoms, anxiety and mood disturbances. While an overall relationship between global Pittsburg Sleep Quality Index score and emotion and attention measures was not supported, poor sleep quality, as an independent component, was associated with better memory for negative stimuli and a deficit in sustained attention to non-emotional stimuli. Importantly, these effects were not sensitive to stress, chronotype or time of day. Combined, these results suggest that individuals with poor sleep quality show an increase in affective symptomatology as well as a negative cognitive bias with a concomitant decrease in sustained attention to non-emotional stimuli. © 2015 European Sleep Research Society.
Mesfin, Eyob Abera; Taye, Binyam; Belay, Getachew; Ashenafi, Aytenew; Girma, Veronica
2017-10-01
Quality laboratory service is an essential component of health care system but in Sub-Saharan Africa such as Ethiopia, laboratories quality system remains weak due to several factors and it needs more attention to strengthen its capacity and quality system. A cross sectional study was conducted using a questionnaire to assess factors affecting the quality of laboratory service at private and public health institutions in Addis Ababa. A total of 213 laboratory professionals participated in the study and 131 (61.5%) participants had bachelor degree. Majority, 133 (62.4%), of the professionals did not attend any work related training. Seventy five (35.2%) respondents believed that their laboratories did not provide quality laboratory services and the major reported factors affecting provision of quality services were shortage of resources (64.3%), poor management support (57.3%), poor equipment quality (53.4%), high workload (41.1%), lack of equipment calibration (38.3%) and lack of knowledge (23.3%). Moreover logistic regression analysis showed that provision of quality laboratory service was significantly associated with result verification (AOR=9.21, 95% CI=2.26, 37.48), internal quality control (AOR= 6.11, 95% CI=2.11, 17.70), turnaround time (AOR=5.11, 95% CI=1.94, 13.46), shortage of equipment (AOR=7.76, 95% CI=2.55, 23.66), communication with clinicians (AOR=3.24, 95% CI=1.25, 8.41) and lack of job description (AOR=3.67, 95% CI=1.319, 10.22). In conclusion, the major factors that affecting the quality of laboratory service were associated with poor human resource management, poor resources provision, poor management commitment, ineffective communication system and lack of well-established quality management system.
Taye, Binyam; Belay, Getachew; Ashenafi, Aytenew; Girma, Veronica
2017-01-01
Background Quality laboratory service is an essential component of health care system but in Sub-Saharan Africa such as Ethiopia, laboratories quality system remains weak due to several factors and it needs more attention to strengthen its capacity and quality system. Methodology A cross sectional study was conducted using a questionnaire to assess factors affecting the quality of laboratory service at private and public health institutions in Addis Ababa. Results A total of 213 laboratory professionals participated in the study and 131 (61.5%) participants had bachelor degree. Majority, 133 (62.4%), of the professionals did not attend any work related training. Seventy five (35.2%) respondents believed that their laboratories did not provide quality laboratory services and the major reported factors affecting provision of quality services were shortage of resources (64.3%), poor management support (57.3%), poor equipment quality (53.4%), high workload (41.1%), lack of equipment calibration (38.3%) and lack of knowledge (23.3%). Moreover logistic regression analysis showed that provision of quality laboratory service was significantly associated with result verification (AOR=9.21, 95% CI=2.26, 37.48), internal quality control (AOR= 6.11, 95% CI=2.11, 17.70), turnaround time (AOR=5.11, 95% CI=1.94, 13.46), shortage of equipment (AOR=7.76, 95% CI=2.55, 23.66), communication with clinicians (AOR=3.24, 95% CI=1.25, 8.41) and lack of job description (AOR=3.67, 95% CI=1.319, 10.22). Conclusion In conclusion, the major factors that affecting the quality of laboratory service were associated with poor human resource management, poor resources provision, poor management commitment, ineffective communication system and lack of well-established quality management system. PMID:29075171
The Maladies of Water and War: Addressing Poor Water Quality in Iraq
2013-01-01
Water is essential in providing nutrients, but contaminated water contributes to poor population health. Water quality and availability can change in unstructured situations, such as war. To develop a practical strategy to address poor water quality resulting from intermittent wars in Iraq, I reviewed information from academic sources regarding waterborne diseases, conflict and war, water quality treatment, and malnutrition. The prevalence of disease was high in impoverished, malnourished populations exposed to contaminated water sources. The data aided in developing a strategy to improve water quality in Iraq, which encompasses remineralized water from desalination plants, health care reform, monitoring and evaluation systems, and educational public health interventions. PMID:23597360
Tang, Yunzhao; Meng, Lingling; Li, Daiqing; Yang, Min; Zhu, Yanjuan; Li, Chenguang; Jiang, Zhenhuan; Yu, Ping; Li, Zhu; Song, Hongna; Ni, Changlin
2014-01-01
Copious evidence from epidemiological and laboratory studies has revealed that sleep status is associated with glucose intolerance, insulin resistance, thus increasing the risk of developing type 2 diabetes. The aim of this study was to reveal the interaction of sleep quality and sleep quantity on glycemic control in patients with type 2 diabetes mellitus. From May 2013 to May 2014, a total of 551 type 2 diabetes patients in Tianjin Metabolic Diseases Hospital were enrolled. Blood samples were taken to measure glycosylated hemoglobin (HbA1c), and all the patients completed the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) questionnaire to evaluate their sleep status. "Good sleep quality" was defined as PQSI <5, "average sleep quality" was defined as PQSI 6-8, and "poor sleep quality" was defined as PQSI >8. Poor glycemic control was defined as HbA1c ≥7%. Sleep quantity was categorized as <6, 6-8, and >8 hours/night. Short sleep time was defined as sleep duration <6 hours/night. In the poor glycemic control group, the rate of patients who had insufficient sleep was much higher than that in the other group (χ(2) = 11.16, P = 0.037). The rate of poor sleep quality in poor glycemic control group was much greater than that in the average control group (χ(2) = 9.79, P = 0.007). After adjusted by gender, age, body mass index, and disease duration, the adjusted PSQI score's OR was 1.048 (95% CI 1.007-1.092, P = 0.023) for HbA1c level. The sleep duration's OR was 0.464 (95% CI 0.236-0.912, P = 0.026) for HbA1c level. One-way analysis of variance showed that the poor sleep quality group had the highest homeostasis model assessment-insulin resistance (P < 0.01). Inadequate sleep, in both quality and quantity, should be regarded as a plausible risk factor for glycemic control in type 2 diabetes. Poor sleep might bring much more serious insulin resistance and could be the reason for bad glycemic control. A good night's sleep should be seen as a critical health component tool in the prevention and treatment of type 2 diabetes. It is important for clinicians to target the root causes of short sleep duration and/or poor sleep quality.
NASA Technical Reports Server (NTRS)
Sun, Xiaoli; Davidson, Frederic M.
1990-01-01
A newly developed 220 Mbps free-space 4-ary pulse position modulation (PPM) direct detection optical communication system is described. High speed GaAs integrated circuits were used to construct the PPM encoder and receiver electronic circuits. Both PPM slot and word timing recovery were provided in the PPM receiver. The optical transmitter consisted of an AlGaAs laser diode (Mitsubishi ML5702A, lambda=821nm) and a high speed driver unit. The photodetector consisted of a silicon avalanche photodiode (APD) (RCA30902S) preceded by an optical interference filter (delta lambda=10nm). Preliminary tests showed that the self-synchronized PPM receiver could achieve a receiver bit error rate of less than 10(exp -6) at 25 nW average received optical signal power or 360 photons per transmitted information bit. The relatively poor receiver sensitivity was believed to be caused by the insufficient electronic bandwidth of the APD preamplifier and the poor linearity of the preamplifier high frequency response.
Bio-geo-optical data collected in the Neuse River Estuary, North Carolina, USA were used to develop a semi-empirical optical algorithm for assessing inherent optical properties associated with water quality components (WQCs). Three wavelengths (560, 665 and 709 nm) were explored ...
Rabin, Alon; Einstein, Ofira; Kozol, Zvi
2018-05-01
To explore the association between ankle dorsiflexion (DF) range of motion (ROM), and hip abductor muscle strength, to visually-assessed quality of movement during jump-landing. Cross-sectional. Gymnasium of participating teams. 37 female volleyball players. Quality of movement in the frontal-plane, sagittal-plane, and overall (both planes) was visually rated as "good/moderate" or "poor". Weight-bearing Ankle DF ROM and hip abductor muscle strength were compared between participants with differing quality of movement. Weight-bearing DF ROM on both sides was decreased among participants with "poor" sagittal-plane quality of movement (dominant side: 50.8° versus 43.6°, P = .02; non-dominant side: 54.6° versus 45.9°, P = .01), as well as among participants with an overall "poor" quality of movement (dominant side: 51.8° versus 44.0°, P < .01; non-dominant side: 56.5° versus 45.1°, P < .01). Weight-bearing ankle DF on the non-dominant side was decreased among participants with a "poor" frontal-plane quality of movement (53.9° versus 46.0°, P = .02). No differences in hip abductor muscle strength were noted between participants with differing quality of movement. Visual assessment of jump-landing can detect differences in quality of movement that are associated with ankle DF ROM. Clinicians observing a poor quality of movement may wish to assess ankle DF ROM. Copyright © 2018 Elsevier Ltd. All rights reserved.
Menadione degrades the optical quality and mitochondrial integrity of bovine crystalline lenses
Olsen, Kenneth W.; Bantseev, Vladimir
2011-01-01
Purpose The crystalline lens is a unique cellular organ that performs metabolic processes while maintaining transparency for optical functionality. Mitochondria play a role in providing cells with aerobic respiration necessary for these metabolic processes. Using menadione, a mitochondria-specific inhibitor of the quinone family, and bovine lenses in vitro, this study was undertaken to determine whether a relationship exists between mitochondrial function and optical function. Methods Bovine lenses were treated with 50 μM, 200 μM, 600 μM, and 1,000 μM menadione and lens optical function, assessed as optical quality, was observed over 9 days. Confocal micrographs of mitochondria in superficial secondary fiber cells were also analyzed in 50 μM, 200 μM, and 600 μM menadione-treated lenses over 48 h. Results A decrease in lens optical quality was observed in a dose-dependent manner within 24 h for the 200 µM- (p=0.0422), 600 µM- (p<0.0001), and 1,000 μM- (p<0.0001) treated lenses. No change in optical quality was observed for the 50 μM-treated lenses. Analysis of confocal micrographs indicated a trend of shorter mitochondria for 200 μM- and 600 µM-treated lenses with time and analysis of the distributions of mitochondrial lengths indicated a relative increase in the number of shorter mitochondria with higher doses of, and longer exposures to, menadione. Conclusions The data show that menadione has a detrimental effect on mitochondrial integrity and this change is associated with degradation of optical quality, suggesting a possible link between mitochondrial function and optical function. PMID:21283527
Menadione degrades the optical quality and mitochondrial integrity of bovine crystalline lenses.
Olsen, Kenneth W; Bantseev, Vladimir; Choh, Vivan
2011-01-26
The crystalline lens is a unique cellular organ that performs metabolic processes while maintaining transparency for optical functionality. Mitochondria play a role in providing cells with aerobic respiration necessary for these metabolic processes. Using menadione, a mitochondria-specific inhibitor of the quinone family, and bovine lenses in vitro, this study was undertaken to determine whether a relationship exists between mitochondrial function and optical function. Bovine lenses were treated with 50 μM, 200 μM, 600 μM, and 1,000 μM menadione and lens optical function, assessed as optical quality, was observed over 9 days. Confocal micrographs of mitochondria in superficial secondary fiber cells were also analyzed in 50 μM, 200 μM, and 600 μM menadione-treated lenses over 48 h. A decrease in lens optical quality was observed in a dose-dependent manner within 24 h for the 200 µM- (p=0.0422), 600 µM- (p<0.0001), and 1,000 μM- (p<0.0001) treated lenses. No change in optical quality was observed for the 50 μM-treated lenses. Analysis of confocal micrographs indicated a trend of shorter mitochondria for 200 μM- and 600 µM-treated lenses with time and analysis of the distributions of mitochondrial lengths indicated a relative increase in the number of shorter mitochondria with higher doses of, and longer exposures to, menadione. The data show that menadione has a detrimental effect on mitochondrial integrity and this change is associated with degradation of optical quality, suggesting a possible link between mitochondrial function and optical function.
Indoor Air Quality in Schools: Clean Air Is Good Business.
ERIC Educational Resources Information Center
Guarneiri, Michele A.
2003-01-01
Describes the effect of poor indoor air quality (IAQ) on student health, the cost of safeguarding good IAQ, the cause of poor IAQ in schools, how to tell whether a school has an IAQ problem, and how the U.S. Environmental Protection Agency can help schools improve indoor air quality though the use of their free "Indoor Air Quality Tools for…
Factors associated with health-related quality of life among operating engineers.
Choi, Seung Hee; Redman, Richard W; Terrell, Jeffrey E; Pohl, Joanne M; Duffy, Sonia A
2012-11-01
Because health-related quality of life among blue-collar workers has not been well studied, the purpose of this study was to determine factors associated with health-related quality of life among Operating Engineers. With cross-sectional data from a convenience sample of 498 Operating Engineers, personal and health behavioral factors associated with health-related quality of life were examined. Multivariate linear regression analysis revealed that personal factors (older age, being married, more medical comorbidities, and depression) and behavioral factors (smoking, low fruit and vegetable intake, low physical activity, high body mass index, and low sleep quality) were associated with poor health-related quality of life. Operating Engineers are at risk for poor health-related quality of life. Underlying medical comorbidities and depression should be well managed. Worksite wellness programs addressing poor health behaviors may be beneficial.
Biological interaction between sleep quality and depression in type 2 diabetes.
Zhao, J; Li, X-L; Han, K; Tao, Z-Q; Wu, Z-M
2016-07-01
To explore the interaction of sleep quality and depression among patients with type 2 diabetes mellitus (T2DM). With multistage cluster sampling, the living quality of all participants was investigated. The indicator of interaction was calculated according to the delta method and non-conditional logistic regression model. There were 944 residents involved in the final analysis including 365 males and 579 females. The average age was (64 ± 10.2) years. The rate of poor sleep quality and poor sleep quality combined depression were 33.6% and 40.1%, respectively. Due to poor sleep quality and depression in patients with T2DM, the combined interaction index was 2.48 (95% CI 1.44-4.29), the relative excess risk was 3.42 (95% CI 2.16-4.67), and the attributable proportion was 0.51 (95% CI 0.32-0.70). An additive interaction rather than a multiplicative interaction of poor sleep quality and depression in affecting the quality of life was found in T2DM patients. When both factors existed at the same time, the interaction effect of these 2 factors was greater than the sum of the two factors.
Kruger, Daniel J; Kodjebacheva, Gergana D; Cupal, Suzanne
2017-08-01
After inadequate official response to community concerns over water quality following changes in Flint's municipal water supply, this study sought evidence for a relationship between water quality and community mental health. The Speak to Your Health Community Survey is a community-based participatory component of the health surveillance system in Genesee County, Michigan. This cross-sectional survey recruits participants from every residential Census Tract of the county and strives for demographic representativeness. Respondents (n=834) rated their tap water quality (taste, smell, appearance) as poor (36%), fair (18%), good (20%), very good (17%), and excellent (10%). They rated their sleep quality as poor (12%), fair (28%), good (39%), very good (18%), and excellent (4%), and had an average (SD) sleep length of 408(90) minutes. Controlling for age, sex, years of education, and whether respondents were African American and Hispanic/Latino/a, lower perceived tap water quality was associated with lower sleep quality and shorter sleep length. Results indicate that adverse health conditions related to the water crisis extend beyond lead poisoning in children and include deterioration of sleep conditions among adult residents. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.
Denhaerynck, Kris; Huynh-Do, Uyen; Binet, Isabelle; Hadaya, Karine; De Geest, Sabina
2017-01-01
Background Poor sleep quality (SQ) is common after solid organ transplantation; however, very little is known about its natural history. We assessed the changes in SQ from pre- to 3 years post-transplant in adult heart, kidney, liver and lung recipients included in the prospective nation-wide Swiss Transplant Cohort Study. We explored associations with selected variables in patients suffering persistent poor SQ compared to those with good or variable SQ. Methods Adult single organ transplant recipients enrolled in the Swiss Transplant Cohort Study with pre-transplant and at least 3 post-transplant SQ assessment data were included. SQ was self-reported pre-transplant (at listing), then at 6, 12, 24 and 36 months post-transplant. A single SQ item was used to identify poor (0–5) and good sleepers (6–10). Between organ groups, SQ was compared via logistic regression analysis with generalized estimating equations. Within the group reporting persistently poor SQ, we used logistic regression or Kaplan-Meier analysis as appropriate to check for differences in global quality of life and survival. Results In a sample of 1173 transplant patients (age: 52.1±13.2 years; 65% males; 66% kidney, 17% liver, 10% lung, 7% heart) transplanted between 2008 and 2012, pre- transplant poor SQ was highest in liver (50%) and heart (49%) recipients. Overall, poor SQ decreased significantly from pre-transplant (38%) to 24 months post-transplant (26%) and remained stable at 3 years (29%). Patients reporting persistently poor SQ had significantly more depressive symptomatology and lower global quality of life. Conclusion Because self-reported poor SQ is related to poorer global quality of life, these results emphasize the need for further studies to find suitable treatment options for poor SQ in transplant recipients. PMID:29020112
Sorghum response to foliar application of phosphorus and potassium with saline water irrigation
USDA-ARS?s Scientific Manuscript database
Increasing demand for fresh water resources for urban and industrial uses is leading to limited availability of better quality water for crop irrigation. Therefore, crop response to poor quality irrigation water (ex: saline water), and strategies to mitigate the negative effects of poor quality irri...
Schiavetti, Benedetta; Wynendaele, Evelien; De Spiegeleer, Bart; Mbinze, Geremie J; Kalenda, Nicodème; Marini, Roland; Melotte, Vera; Hasker, Epco; Meessen, Bruno; Ravinetto, Raffaella; Van der Elst, Josiane; Mutolo Ngeleka, Daniel
2018-03-01
Poor-quality medicines are a threat to public health in many low- and middle-income countries, and prospective surveys are needed to inform corrective actions. Therefore, we conducted a cross-sectional survey on a sample of products used for children and available in the private market in Kinshasa, Democratic Republic Congo: amoxicillin (AX) and artemether/lumefantrine (AL), powders for suspension, and paracetamol (PC) tablets 500 mg. Overall, 417 products were covertly purchased from 61 wholesalers. To obtain a representative sample, the products were weighted on their market shares and a subset of 239 samples was randomly extracted to undergo in-depth visual inspection locally, and they were chemically assessed at two accredited laboratories in Belgium. Samples were defined of "poor-quality" if they failed to comply with at least one specification of the International Pharmacopoeia (for AL) or United States Pharmacopoeia 37 (for AX and PC). Results are reported according to the Medicine Quality Assessment Reporting Guideline. The visual inspection detected nonconformities in the aspects of antimalarial powders for suspension, and poor-quality labels across all medicine types. According to chemical analysis, 27.2% samples were of poor quality and 59.5% of AL samples were underdosed in artemether. Poor quality was more frequent for locally manufactured antimalarials (83.3%, P = 0.021; 86.4%, P = 0.022) and PC (4.8%, P = 0.000). The poor quality of the surveyed products may decrease the treatment's efficacy and favor the development of resistances to antimalarials. It is hoped that these findings may guide the corrective actions of the Democratic Republic of Congo Regulatory Authority, which was the main partner in the research.
Poor Sleep Quality, Antepartum Depression and Suicidal Ideation among Pregnant Women
Gelaye, Bizu; Addae, Gifty; Neway, Beemnet; Larrabure-Torrealva, Gloria T.; Qiu, Chunfang; Stoner, Lee; Fernandez, Miguel Angel Luque; Sanchez, Sixto E.; Williams, Michelle A.
2016-01-01
Objective To evaluate the independent and combined associations of maternal self-reported poor sleep quality and antepartum depression with suicidal ideation during the third trimester Methods A cross-sectional study was conducted among 1,298 pregnant women (between 24 and 28 gestational weeks) attending prenatal clinics in Lima, Peru. Antepartum depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9). The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to assess sleep quality. Multivariate logistical regression procedures were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) after adjusting for putative confounders. Results Approximately, 17% of women were classified as having poor sleep quality (defined using the recommended criteria of PSQI global score of >5 vs. ≤5). Further, the prevalence of antepartum depression and suicidal ideation were 10.3% and 8.5%, respectively in this cohort. After adjusting for confounders including depression, poor sleep quality was associated with a 2.81-fold increased odds of suicidal ideation (OR=2.81; 95% CI 1.78–4.45). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 28% increase in odds for suicidal ideation, even after adjusting for depression (OR=1.28; 95% CI 1.15–1.41). The odds of suicidal ideation was particularly high among depressed women with poor sleep quality (OR=13.56 95% CI 7.53–24.41) as compared with women without either risk factor. Limitations This cross-sectional study utilized self-reported data. Causality cannot be inferred, and results may not be fully generalizable. Conclusion Poor sleep quality, even after adjusting for depression, is associated with antepartum suicidal ideation. Our findings support the need to explore sleep-focused interventions for pregnant women. PMID:27930912
Poor sleep quality, antepartum depression and suicidal ideation among pregnant women.
Gelaye, Bizu; Addae, Gifty; Neway, Beemnet; Larrabure-Torrealva, Gloria T; Qiu, Chunfang; Stoner, Lee; Luque Fernandez, Miguel Angel; Sanchez, Sixto E; Williams, Michelle A
2017-02-01
To evaluate the independent and combined associations of maternal self-reported poor sleep quality and antepartum depression with suicidal ideation during the third trimester METHODS: A cross-sectional study was conducted among 1298 pregnant women (between 24 and 28 gestational weeks) attending prenatal clinics in Lima, Peru. Antepartum depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9). The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to assess sleep quality. Multivariate logistical regression procedures were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) after adjusting for putative confounders. Approximately, 17% of women were classified as having poor sleep quality (defined using the recommended criteria of PSQI global score of >5 vs. ≤5). Further, the prevalence of antepartum depression and suicidal ideation were 10.3% and 8.5%, respectively in this cohort. After adjusting for confounders including depression, poor sleep quality was associated with a 2.81-fold increased odds of suicidal ideation (OR=2.81; 95% CI 1.78-4.45). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in a 28% increase in odds for suicidal ideation, even after adjusting for depression (OR=1.28; 95% CI 1.15-1.41). The odds of suicidal ideation was particularly high among depressed women with poor sleep quality (OR=13.56 95% CI 7.53-24.41) as compared with women without either risk factor. This cross-sectional study utilized self-reported data. Causality cannot be inferred, and results may not be fully generalizable. Poor sleep quality, even after adjusting for depression, is associated with antepartum suicidal ideation. Our findings support the need to explore sleep-focused interventions for pregnant women. Copyright © 2016 Elsevier B.V. All rights reserved.
Impact of weak social ties and networks on poor sleep quality: A case study of Iranian employees.
Masoudnia, Ebrahim
2015-12-01
The poor sleep quality is one of the major risk factors of somatic, psychiatric and social disorders and conditions as well as the major predictors of quality of employees' performance. The previous studies in Iran had neglected the impacts of social factors including social networks and ties on adults sleep quality. Thus, the aim of the current research was to determine the relationship between social networks and adult employees' sleep quality. This study was conducted with a correlational and descriptive design. Data were collected from 360 participants (183 males and 177 females) who were employed in Yazd public organizations in June and July of 2014. These samples were selected based on random sampling method. In addition, the measuring tools were the Pittsburgh Sleep Quality Index (PSQI) and Social Relations Inventory (SRI). Based on the results, the prevalence rate of sleep disorder among Iranian adult employees was 63.1% (total PSQI>5). And, after controlling for socio-demographic variables, there was significant difference between individuals with strong and poor social network and ties in terms of overall sleep quality (p<.01), subjective sleep quality (p<.01), habitual sleep efficiency (p<.05), and daytime dysfunction (p<.01). The results also revealed that the employees with strong social network and ties had better overall sleep quality, had the most habitual sleep efficiency, and less daytime dysfunction than employees with poor social network and ties. It can be implied that the weak social network and ties serve as a risk factor for sleep disorders or poor sleep quality for adult employees. Therefore, the social and behavioral interventions seem essential to improve the adult's quality sleep. Copyright © 2015 Elsevier B.V. All rights reserved.
Bani-Issa, Wegdan; Al-Shujairi, Arwa M; Patrick, Linda
2018-04-01
To estimate the relationship of sleep quality with health-related quality of life (HRQOL) in persons with diabetes mellitus type 2 (DMT2) living in the United Arab Emirates (UAE). DMT2 is an epidemic health condition in the UAE that has enormous impacts on heath, and consequent effects on HRQOL. However, because of an absence of screening for quality of sleep, people with DMT2 who experience poor sleep are likely to go untreated, which may compound the distressing impacts of DMT2 on their HRQOL. This is a cross-sectional quantitative research design. A sample of 268 participants with DMT2 were recruited from community healthcare settings in the UAE using cluster sampling. Participants completed questionnaires, including the Pittsburgh Sleep Quality Index (PSQI) and the World Health Organization HRQOL. Data analysis used descriptive and correlational statistics. Of the 268 participants, 34% identified as "poor sleepers" and 55% had poor HRQOL. Poor sleepers showed significantly lower scores for HRQOL than good sleepers. The global PSQI scores were found to be independently predictive of global HRQOL. Subjective perceptions of sleep quality, the use of sleep medications and impaired daytime functioning were the variables found to have the highest correlations with global HRQOL and its four domains. This study found that people with DMT2 who indicate experiencing poor quality sleep are more likely to show a negative correlation with HRQOL. Additional research is needed to investigate how poor sleep may impact the health of people with DMT2. Findings suggest that assessment of sleep quality should be an essential component of diabetes care. Understanding sleep practices may aid public health practitioners and other healthcare providers in the design of culturally appropriate interventions to improve sleep quality in persons with DMT2. © 2017 John Wiley & Sons Ltd.
Dietary intake and risk factors for poor diet quality among children in Nova Scotia.
Veugelers, Paul J; Fitzgerald, Angela L; Johnston, Elizabeth
2005-01-01
Public health policies promote healthy nutrition but evaluations of children's adherence to dietary recommendations and studies of risk factors of poor nutrition are scarce, despite the importance of diet for the temporal increase in the prevalence of childhood obesity. Here we examine dietary intake and risk factors for poor diet quality among children in Nova Scotia to provide direction for health policies and prevention initiatives. In 2003, we surveyed 5,200 grade five students from 282 public schools in Nova Scotia, as well as their parents. We assessed students' dietary intake (Harvard's Youth Adolescent Food Frequency Questionnaire) and compared this with Canadian food group and nutrient recommendations. We summarized diet quality using the Diet Quality Index International, and used multilevel regression methods to evaluate potential child, parental and school risk factors for poor diet quality. In Nova Scotia, 42.3% of children did not meet recommendations for milk products nor did they meet recommendations for the food groups 'Vegetables and fruit' (49.9%), 'Grain products' (54.4%) and 'Meat and alternatives' (73.7%). Children adequately met nutrient requirements with the exception of calcium and fibre, of which intakes were low, and dietary fat and sodium, of which intakes were high. Skipping meals and purchasing meals at school or fast-food restaurants were statistically significant determinants of poor diet. Parents' assessment of their own eating habits was positively associated with the quality of their children's diets. Dietary intake among children in Nova Scotia is relatively poor. Explicit public health policies and prevention initiatives targeting children, their parents and schools may improve diet quality and prevent obesity.
Course for undergraduate students: analysis of the retinal image quality of a human eye model
NASA Astrophysics Data System (ADS)
del Mar Pérez, Maria; Yebra, Ana; Fernández-Oliveras, Alicia; Ghinea, Razvan; Ionescu, Ana M.; Cardona, Juan C.
2014-07-01
In teaching of Vision Physics or Physiological Optics, the knowledge and analysis of the aberration that the human eye presents are of great interest, since this information allows a proper evaluation of the quality of the retinal image. The objective of the present work is that the students acquire the required competencies which will allow them to evaluate the optical quality of the human visual system for emmetropic and ammetropic eye, both with and without the optical compensation. For this purpose, an optical system corresponding to the Navarro-Escudero eye model, which allows calculating and evaluating the aberration of this eye model in different ammetropic conditions, was developed employing the OSLO LT software. The optical quality of the visual system will be assessed through determinations of the third and fifth order aberration coefficients, the impact diagram, wavefront analysis, calculation of the Point Spread Function and the Modulation Transfer Function for ammetropic individuals, with myopia or hyperopia, both with or without the optical compensation. This course is expected to be of great interest for student of Optics and Optometry Sciences, last courses of Physics or medical sciences related with human vision.
An improved methodology for heliostat testing and evaluation at the Plataforma Solar de Almería
NASA Astrophysics Data System (ADS)
Monterreal, Rafael; Enrique, Raúl; Fernández-Reche, Jesús
2017-06-01
The optical quality of a heliostat basically quantifies the difference between the scattering effects of the actual solar radiation reflected on its optical surface, compared to the so called canonical dispersion, that is, the one reflected on an optical surface free of constructional errors (paradigm). However, apart from the uncertainties of the measuring process itself, the value of the optical quality must be independent of the measuring instrument; so, any new measuring techniques that provide additional information about the error sources on the heliostat reflecting surface would be welcome. That error sources are responsible for the final optical quality value, with different degrees of influence. For the constructor of heliostats it will be extremely useful to know the value of the classical sources of error and their weight on the overall optical quality of a heliostat, such as facets geometry or focal length, as well as the characteristics of the heliostat as a whole, i.e., its geometry, focal length, facets misalignment and also the possible dependence of these effects with mechanical and/or meteorological factors. It is the goal of the present paper to unfold these optical quality error sources by exploring directly the reflecting surface of the heliostat with the help of a laser-scanner device and link the result with the traditional methods of heliostat evaluation at the Plataforma Solar de Almería.
Demir Zencirci, Ayten; Arslan, Sümeyye
2011-01-01
Aim To assess the relationship between sleep quality and demographic variables, morning-evening type, and burnout in nurses who work shifts. Methods We carried out a cross-sectional self-administered study with forced choice and open-ended structured questionnaires – Pittsburg Sleep Quality Index, Morningness-eveningness Questionnaire, and Maslach Burnout Inventory. The study was carried out at Gazi University Medicine Faculty Hospital of Ankara on 524 invited nurses from July to September 2008, with a response rate of 89.94% (n = 483). Descriptive and inferential statistics were applied to determine the risk factors of poor sleep quality. Results Most socio-demographic variables did not affect sleep quality. Participants with poor sleep quality had quite high burnout levels. Most nurses who belonged to a type that is neither morning nor evening had poor sleep quality. Nurses who experienced an incident worsening their sleep patterns (P < 0.001) and needlestick or sharp object injuries (P = 0.010) in the last month had poor sleep quality. The subjective sleep quality and sleep latency points of evening types within created models for the effect of burnout dimensions were high. Conclusions Nurses working consistently either in the morning or at night had better sleep quality than those working rotating shifts. Further studies are still needed to develop interventions that improve sleep quality and decrease burnout in nurses working shifts. PMID:21853548
Molecular Beam Epitaxy Growth of High Crystalline Quality LiNbO3
NASA Astrophysics Data System (ADS)
Tellekamp, M. Brooks; Shank, Joshua C.; Goorsky, Mark S.; Doolittle, W. Alan
2016-12-01
Lithium niobate is a multi-functional material with wide reaching applications in acoustics, optics, and electronics. Commercial applications for lithium niobate require high crystalline quality currently limited to bulk and ion sliced material. Thin film lithium niobate is an attractive option for a variety of integrated devices, but the research effort has been stagnant due to poor material quality. Both lattice matched and mismatched lithium niobate are grown by molecular beam epitaxy and studied to understand the role of substrate and temperature on nucleation conditions and material quality. Growth on sapphire produces partially coalesced columnar grains with atomically flat plateaus and no twin planes. A symmetric rocking curve shows a narrow linewidth with a full width at half-maximum (FWHM) of 8.6 arcsec (0.0024°), which is comparable to the 5.8 arcsec rocking curve FWHM of the substrate, while the film asymmetric rocking curve is 510 arcsec FWHM. These values indicate that the individual grains are relatively free of long-range disorder detectable by x-ray diffraction with minimal measurable tilt and twist and represents the highest structural quality epitaxial material grown on lattice mismatched sapphire without twin planes. Lithium niobate is also grown on lithium tantalate producing high quality coalesced material without twin planes and with a symmetric rocking curve of 193 arcsec, which is nearly equal to the substrate rocking curve of 194 arcsec. The surface morphology of lithium niobate on lithium tantalate is shown to be atomically flat by atomic force microscopy.
Kanagasabai, Thirumagal; Ardern, Chris I
2015-01-01
Sleep is vital for cardiometabolic health, but a societal shift toward poor sleep is a prominent feature of many modern cultures. Concurrently, factors such as diet and lifestyle have also changed and may mediate the relationship between sleep quality and cardiometabolic health. Objectives were to explore (1) the interrelationship and (2) mediating effect of inflammation, oxidative stress, and antioxidants on sleep quality and cardiometabolic health. Cross-sectional data from the US National Health and Nutritional Examination Survey 2005-06 (≥20 y; N = 2,072) was used. Cardiometabolic health was defined as per the Joint Interim Statement; overall sleep quality was determined from six sleep habits and categorized as good, fair, poor, and very poor. Fair quality sleepers had optimal inflammation, oxidative stress, and antioxidant levels. Inflammation was above the current clinical reference range across all sleep quality categories, while oxidative stress was only within the clinical reference range for fair sleep quality. Selected sleep quality-cardiometabolic health relationships were mediated by inflammation, oxidative stress, and antioxidants and were moderated by sex. Our results provide initial evidence of a potential role for inflammation, oxidative stress, and antioxidants in the pathway between poor sleep quality-cardiometabolic decline. Further prospective research is needed to confirm our results.
Sleep and its association with aggression among prisoners: Quantity or quality?
Barker, Lyndsie Fiona; Ireland, Jane L; Chu, Simon; Ireland, Carol A
2016-01-01
The current paper aims to examine the association between self-reported sleep quality and quantity and how these relate to aggression motivation and hostile cognition in a male prisoner sample. The cognitive component of sleep, namely perception, is consequently a variable of particular interest and one neglected by previous research. Two independent studies are presented. The first comprised 95 adult male prisoners who completed a sleep quality index along with measures of implicit and explicit aggression. The second study extended this to consider aggression motivation and hostile attribution biases using a sample of 141 young male adult prisoners. In study one, sleep quantity and indicators of sleep quality were found not to associate with aggression whereas the perception of poor sleep did; those perceiving poor sleep quality were more likely than those perceiving good sleep to report they had perpetrated aggression in the previous week and to report higher levels of implicit aggression. Study two found that while increased indicators of poor sleep quality were associated with lower prosocial attribution tendencies and higher levels of reactive and proactive aggression, sleep quantity was not associated. The perception of poor quality sleep was important; those perceiving poor sleep were more likely to report higher levels of reactive and proactive aggression than those reporting good sleep. Collectively the studies highlight the importance of accounting for the perception of sleep quality as an important cognitive component in understanding the association between sleep and aggression. Copyright © 2016 Elsevier Ltd. All rights reserved.
Poor sleep quality and insufficient sleep of a collegiate student-athlete population.
Mah, Cheri D; Kezirian, Eric J; Marcello, Brandon M; Dement, William C
2018-06-01
Poor and inadequate sleep negatively impact cognitive and physical functioning and may also affect sports performance. The study aim is to examine sleep quality, sleep duration, and daytime sleepiness in collegiate student-athletes across a wide range of sports. Questionnaire. University setting. 628 athletes across 29 varsity teams at Stanford University. Athletes completed a questionnaire inquiring about sleep quality via a modified Pittsburgh Sleep Quality Index (PSQI), sleep duration, and daytime sleepiness via Epworth Sleepiness Scale. Sleep quality on campus and while traveling for competition was rated on a 10-point scale. Collegiate athletes were classified as poor sleepers (PSQI 5.38 ± 2.45), and 42.4% of athletes experience poor sleep quality (reporting PSQI global scores >5). Athletes reported lower sleep quality on campus than when traveling for competition (7.1 vs 7.6, P< .001). Inadequate sleep was demonstrated by 39.1% of athletes that regularly obtain <7 hours of sleep on weekdays. Fifty-one percent of athletes reported high levels of daytime sleepiness with Epworth scores ≥10. Teen student-athletes in the first and second year of college reported the highest mean levels of daytime sleepiness. Greater total sleep time was associated with daytime functioning including lower frequency of difficulty waking up for practice or class (P< .001) and lower frequency of trouble staying awake during daily activities (P< .001). Collegiate athletes frequently experience poor sleep quality, regularly obtain insufficient sleep, and commonly exhibit daytime sleepiness. Copyright © 2018 National Sleep Foundation. All rights reserved.
Fluidized Bed Sputtering for Particle and Powder Metallization
2013-04-01
Introduction Small particles are often added to material systems to modify mechanical, dielectric, optical, or other properties . However, the particle...the poor mechanical properties of the wax degrade the bulk mechanical properties of the composite material . Thin metal coatings on the catalyst...to create precisely tailored optical properties . Alternating layers of ceramic and metal thin films can be designed to create optical filters that
Power amplification for petawatt Ti: Sapphire lasers: New strategies for high fluence pumping
NASA Astrophysics Data System (ADS)
Canova, F.; Chambaret, J.-P.
2006-06-01
One of the major bottlenecks when we pump large Ti:Sapphire crystals, to reach Petawatt level laser amplification, is the careful control of the spatial energy distribution of Nd:Glass pump lasers. Commercially available nanosecond Nd:Glass and Nd:YAG lasers exhibit poor spatial profile quality especially in the near and in the intermediate field, which can lead to local hot spots, responsible of damages in crystals, and parasitic transverse lasing enhancement, strongly dependent on the profile of the pump beam . For these reasons, it is mandatory to keep the pump beam intensity profile as flat as possible on the pumped crystal. To guarantee the best pumping conditions we are investigating the combined use of DOE (diffractive optical elements) and optical smoothing techniques. In parallel we are starting a study on laser induced damages mechanisms in crystal. With DOE and microlens arrays we plan to guarantee to the beam a supergaussian shape. Simulation and first experiments with both optical systems show that a flat top spatial profile with less than 10% fluctuations and a 8th order supergaussian is possible with the present technology.Optical smoothing will keep the beam free of hot spots. We especially focused on the smoothing techniques involving optical fibers. This is the first time to our knowledge that this technique is applied to the pumping beams for Ti:Sapphire systems. A deep study of laser-crystal interaction will allow us to fully understand the damages created by hot spots. The knowledge of the phenomena involved in laser damages on Ti:Sapphire is mandatory to control the pumping processes and thresholds. In conclusion, mixing the advantages of these different approaches to overcome this bottleneck will allow us to amplify in a safety way femtosecond laser beams to the Petawatt level using Ti:Sapphire crystals.
The interactive effects of housing and neighbourhood quality on psychological well-being.
Jones-Rounds, McKenzie L; Evans, Gary W; Braubach, Matthias
2014-02-01
Many individuals are subject to the physically and mentally detrimental effects of living in substandard housing and inadequate neighbourhoods. We propose that better physical neighbourhood quality can partially offset some of the negative effects of poor housing quality on psychological well-being. Interviews and questionnaires were used to collect data in a cross-sectional study of housing quality, the state of the surrounding environment, and individual health and well-being for 5605 European adults from the Large Analysis and Review of European housing and health Status conducted by WHO in eight European cities. Multilevel random coefficient modelling was used to statistically analyse the main and interactive effects of housing quality and neighbourhood quality on psychological well-being. Socioeconomic status, employment status, gender and marital status were included as statistical controls. Substandard housing quality and poor neighbourhood quality each contribute to lower psychological well-being. Furthermore better neighbourhood quality buffers against the negative effects of poor housing quality on psychological well-being. These results fill a gap in research concerning the ability of neighbourhood quality to amplify or attenuate housing quality impacts on well-being.
Mhaskar, Rahul; Djulbegovic, Benjamin; Magazin, Anja; Soares, Heloisa P.; Kumar, Ambuj
2011-01-01
Objectives To assess whether reported methodological quality of randomized controlled trials (RCTs) reflect the actual methodological quality, and to evaluate the association of effect size (ES) and sample size with methodological quality. Study design Systematic review Setting Retrospective analysis of all consecutive phase III RCTs published by 8 National Cancer Institute Cooperative Groups until year 2006. Data were extracted from protocols (actual quality) and publications (reported quality) for each study. Results 429 RCTs met the inclusion criteria. Overall reporting of methodological quality was poor and did not reflect the actual high methodological quality of RCTs. The results showed no association between sample size and actual methodological quality of a trial. Poor reporting of allocation concealment and blinding exaggerated the ES by 6% (ratio of hazard ratio [RHR]: 0.94, 95%CI: 0.88, 0.99) and 24% (RHR: 1.24, 95%CI: 1.05, 1.43), respectively. However, actual quality assessment showed no association between ES and methodological quality. Conclusion The largest study to-date shows poor quality of reporting does not reflect the actual high methodological quality. Assessment of the impact of quality on the ES based on reported quality can produce misleading results. PMID:22424985
The Beam Characteristics of High Power Diode Laser Stack
NASA Astrophysics Data System (ADS)
Gu, Yuanyuan; Fu, Yueming; Lu, Hui; Cui, Yan
2018-03-01
Direct diode lasers have some of the most attractive features of any laser. They are very efficient, compact, wavelength versatile, low cost, and highly reliable. However, the full utilization of direct diode lasers has yet to be realized. However, the poor quality of diode laser beam itself, directly affect its application ranges, in order to better use of diode laser stack, need a proper correction of optical system, which requires accurate understanding of the diode laser beam characteristics. Diode laser could make it possible to establish the practical application because of rectangular beam patterns which are suitable to make fine bead with less power. Therefore diode laser cladding will open a new field of repairing for the damaged machinery parts which must contribute to recycling of the used machines and saving of cost.
Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio)
Yilmaz, Ozlem; Patinote, Amélie; Nguyen, Thao Vi; Com, Emmanuelle; Lavigne, Regis; Pineau, Charles; Sullivan, Craig V.; Bobe, Julien
2017-01-01
Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine. PMID:29145436
Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio).
Yilmaz, Ozlem; Patinote, Amélie; Nguyen, Thao Vi; Com, Emmanuelle; Lavigne, Regis; Pineau, Charles; Sullivan, Craig V; Bobe, Julien
2017-01-01
Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine.
Optical quality in central serous chorioretinopathy.
Lee, Kyungmin; Sohn, Joonhong; Choi, Jong Gil; Chung, Sung Kun
2014-12-02
To assess optical quality and intraocular scattering using the Optical Quality Analysis System (OQAS) in central serous chorioretinopathy (CSC) and to determine the effects of retinal changes on optical quality. This was a prospective, case-control study. Participants were 29 patients with diagnosis of CSC. The control group consisted of the patients' unaffected eyes. Initial logMAR visual acuity, central macular thickness (by spectral domain optical coherence tomography), and optical quality parameters including modulation transfer function (MTF) cutoff frequency, Strehl (2-dimensional) ratio, and OQAS values at 100%, 20%, and 9% contrast levels were investigated. Objective scattering index (OSI) at 4.0-mm pupil size was assessed in both eyes by using the OQAS. After 3 months of treatment, which included observation and focal laser or injections of antivascular endothelial growth factor, every CSC-affected eye was followed. Main outcome measures were differences between clinical parameters of the CSC-affected eye and those of the control eye and changes in those parameters according to the clinical course of CSC over 3 months. In CSC-affected eyes, the MTF cutoff was significantly reduced (P = 0.01), and OSI was significantly increased (P = 0.03). As macular thickness decreased, OSI decreased but did not become normalized compared to the control eye, nor was it statistically significantly correlated with central macular thickness change. Retinal change affected optical quality and intraocular scatter. Therefore, when the severity of a cataract is assessed using the OQAS, retinal status should be considered when interpreting OQAS values. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Marital quality, health, and aging: gender equity?
Umberson, Debra; Williams, Kristi
2005-10-01
Recent research shows that poor marital quality adversely affects trajectories of physical health over time and that these adverse effects are similar for men and women. These studies test the possibility of gender differences in vulnerability to poor marital quality, but they fail to take into account possible gender differences in exposure to poor marital quality. We present longitudinal evidence to show that although the impact of marital quality on physical health trajectories may be similar for married men and women, generally lower levels of marital quality experienced by women may translate into a sustained disadvantage for the health of married women over the life course. These findings frame the call for renewed theoretical work on gender and marriage that takes into account both gender similarity in response to marital quality as well as gender differences in the experience of marriage over the life course.
Marital Quality, Health, and Aging: Gender Equity?
Umberson, Debra; Williams, Kristi
2011-01-01
Recent research shows that poor marital quality adversely affects trajectories of physical health over time and that these adverse effects are similar for men and women. These studies test the possibility of gender differences in vulnerability to poor marital quality, but they fail to take into account possible gender differences in exposure to poor marital quality. We present longitudinal evidence to show that although the impact of marital quality on physical health trajectories may be similar for married men and women, generally lower levels of marital quality experienced by women may translate into a sustained disadvantage for the health of married women over the life course. These findings frame the call for renewed theoretical work on gender and marriage that takes into account both gender similarity in response to marital quality as well as gender differences in the experience of marriage over the life course. PMID:16251580
Shift Work and Sleep Quality Among Urban Police Officers
Fekedulegn, Desta; Burchfiel, Cecil M.; Charles, Luenda E.; Hartley, Tara A.; Andrew, Michael E.; Violanti, John M.
2016-01-01
Objective The aim of the study was to examine association of shift work with sleep quality in police officers. Methods Data were obtained from the Buffalo Cardio-Metabolic Occupational Police Stress study (n =363). An electronic work history database was used to define shift as day, afternoon, or night for three durations: past month, 1 year, and 15 years. Sleep quality was determined using the Pittsburgh Sleep Quality Index. Results The overall prevalence of poor sleep quality was 54%; 44% for day, 60% for afternoon, and 69% for night shift. Poor sleep quality was 70% more prevalent among night-shift officers (P <0.001) and 49% higher among those on the afternoon shift (P =0.003) relative to officers working on the day shift. Conclusions Night and evening work schedules are associated with elevated prevalence of poor sleep quality among police officers. PMID:26949891
Shift Work and Sleep Quality Among Urban Police Officers: The BCOPS Study.
Fekedulegn, Desta; Burchfiel, Cecil M; Charles, Luenda E; Hartley, Tara A; Andrew, Michael E; Violanti, John M
2016-03-01
The aim of the study was to examine association of shift work with sleep quality in police officers. Data were obtained from the Buffalo Cardio-Metabolic Occupational Police Stress study (n = 363). An electronic work history database was used to define shift as day, afternoon, or night for three durations: past month, 1 year, and 15 years. Sleep quality was determined using the Pittsburgh Sleep Quality Index. The overall prevalence of poor sleep quality was 54%; 44% for day, 60% for afternoon, and 69% for night shift. Poor sleep quality was 70% more prevalent among night-shift officers (P < 0.001) and 49% higher among those on the afternoon shift (P = 0.003) relative to officers working on the day shift. Night and evening work schedules are associated with elevated prevalence of poor sleep quality among police officers.
Sky Quality Meter measurements in a colour-changing world
NASA Astrophysics Data System (ADS)
Sánchez de Miguel, A.; Aubé, M.; Zamorano, J.; Kocifaj, M.; Roby, J.; Tapia, C.
2017-05-01
The Sky Quality Meter (SQM) has become the most common device used to track the evolution of the brightness of the sky from polluted regions to first-class astronomical observatories. A vast database of SQM measurements already exists for many places in the world. Unfortunately, the SQM operates over a wide spectral band and its spectral response interacts with the sky's spectrum in a complex manner. This is why the optical signals are difficult to interpret when the data are recorded in regions with different sources of artificial light. The brightness of the night sky is linked in a complex way to ground-based light emissions, while taking into account atmospheric-induced optical distortion as well as spectral transformation from the underlying ground surfaces. While the spectral modulation of the sky's radiance has been recognized, it still remains poorly characterized and quantified. The impact of the SQM's spectral characteristics on sky-brightness measurements is analysed here for different light sources, including low- and high-pressure sodium lamps, PC-amber and white LEDs, metal halide and mercury lamps. We show that a routine conversion of radiance to magnitude is difficult, or rather impossible, because the average wavelength depends on actual atmospheric and environment conditions, the spectrum of the source and device-specific properties. We correlate SQM readings with both the Johnson astronomical photometry bands and the human system of visual perception, assuming different lighting technologies. These findings have direct implications for the processing of SQM data and for their improvement and/or remediation.
MTF measurements on real time for performance analysis of electro-optical systems
NASA Astrophysics Data System (ADS)
Stuchi, Jose Augusto; Signoreto Barbarini, Elisa; Vieira, Flavio Pascoal; dos Santos, Daniel, Jr.; Stefani, Mário Antonio; Yasuoka, Fatima Maria Mitsue; Castro Neto, Jarbas C.; Linhari Rodrigues, Evandro Luis
2012-06-01
The need of methods and tools that assist in determining the performance of optical systems is actually increasing. One of the most used methods to perform analysis of optical systems is to measure the Modulation Transfer Function (MTF). The MTF represents a direct and quantitative verification of the image quality. This paper presents the implementation of the software, in order to calculate the MTF of electro-optical systems. The software was used for calculating the MTF of Digital Fundus Camera, Thermal Imager and Ophthalmologic Surgery Microscope. The MTF information aids the analysis of alignment and measurement of optical quality, and also defines the limit resolution of optical systems. The results obtained with the Fundus Camera and Thermal Imager was compared with the theoretical values. For the Microscope, the results were compared with MTF measured of Microscope Zeiss model, which is the quality standard of ophthalmological microscope.
Zalvidea; Colautti; Sicre
2000-05-01
An analysis of the Strehl ratio and the optical transfer function as imaging quality parameters of optical elements with enhanced focal length is carried out by employing the Wigner distribution function. To this end, we use four different pupil functions: a full circular aperture, a hyper-Gaussian aperture, a quartic phase plate, and a logarithmic phase mask. A comparison is performed between the quality parameters and test images formed by these pupil functions at different defocus distances.
Recording high quality speech during tagged cine-MRI studies using a fiber optic microphone.
NessAiver, Moriel S; Stone, Maureen; Parthasarathy, Vijay; Kahana, Yuvi; Paritsky, Alexander; Paritsky, Alex
2006-01-01
To investigate the feasibility of obtaining high quality speech recordings during cine imaging of tongue movement using a fiber optic microphone. A Complementary Spatial Modulation of Magnetization (C-SPAMM) tagged cine sequence triggered by an electrocardiogram (ECG) simulator was used to image a volunteer while speaking the syllable pairs /a/-/u/, /i/-/u/, and the words "golly" and "Tamil" in sync with the imaging sequence. A noise-canceling, optical microphone was fastened approximately 1-2 inches above the mouth of the volunteer. The microphone was attached via optical fiber to a laptop computer, where the speech was sampled at 44.1 kHz. A reference recording of gradient activity with no speech was subtracted from target recordings. Good quality speech was discernible above the background gradient sound using the fiber optic microphone without reference subtraction. The audio waveform of gradient activity was extremely stable and reproducible. Subtraction of the reference gradient recording further reduced gradient noise by roughly 21 dB, resulting in exceptionally high quality speech waveforms. It is possible to obtain high quality speech recordings using an optical microphone even during exceptionally loud cine imaging sequences. This opens up the possibility of more elaborate MRI studies of speech including spectral analysis of the speech signal in all types of MRI.
Lohsoonthorn, Vitool; Khidir, Hazar; Casillas, Gardenia; Lertmaharit, Somrat; Tadesse, Mahlet G.; Pensuksan, Wipawan C.; Rattananupong, Thanapoom; Gelaye, Bizu; Williams, Michelle A.
2012-01-01
Purpose Poor sleep and heavy use of caffeinated beverages have been implicated as risk factors for a number of adverse health outcomes. Caffeine consumption and use of other stimulants are common among college students globally. However, to our knowledge, no studies have examined the influence of caffeinated beverages on sleep quality of college students in Southeast Asian populations. We conducted this study to evaluate the patterns of sleep quality; and to examine the extent to which poor sleep quality is associated with consumption of energy drinks, caffeinated beverages and other stimulants among 2,854 Thai college students. Methods A questionnaire was administered to ascertain demographic and behavioral characteristics. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep habits and quality. Chi-square tests and multivariate logistic regression models were used to identify statistically significant associations. Results Overall, the prevalence of poor sleep quality was found to be 48.1%. A significant percent of students used stimulant beverages (58.0%). Stimulant use (OR 1.50; 95%CI 1.28-1.77) was found to be statistically significant and positively associated with poor sleep quality. Alcohol consumption (OR 3.10; 95% CI 1.72-5.59) and cigarette smoking (OR 1.43; 95% CI 1.02-1.98) also had statistically significant association with increased daytime dysfunction. In conclusion, stimulant use is common among Thai college students and is associated with several indices of poor sleep quality. Conclusion Our findings underscore the need to educate students on the importance of sleep and the influences of dietary and lifestyle choices on their sleep quality and overall health. PMID:23239460
Quality of recovery after anaesthesia measured with QoR-40: a prospective observational study.
Guimarães-Pereira, Luís; Costa, Maria; Sousa, Gabriela; Abelha, Fernando
2016-01-01
QoR-40, a 40-item questionnaire on quality of recovery from anaesthesia, has been shown to measure health status after surgery. Our aim was to evaluate the incidence of poor quality of recovery in our Post Anaesthesia Care Unit and to compare their QoR-40 scores before surgery and 3 months later. A prospective observational study was conducted in adult patients consecutively admitted from 18 June to 12 July 2012. The follow-up period was 3 months. We exclude patients submitted to cardiac surgery, neurosurgery, obstetric surgery and with a mini-mental state examination test score lower than 25. The primary endpoint was quality of recovery measured with the validated Portuguese for Portugal version of the QoR-40 before surgery (T0), 24h after surgery (T1) and 3 months after (T2). A total of 114 patients completed the study. Mean QoR-40 score was 169 and patients with poor quality of recovery were identified if their QoR-40 score was lesser than 142. This occurred in 26 patients (24%). Global median scores for patients with poor quality of recovery were lower at T0 (121 vs. 184, p<0.001), at T1 (120 vs. 177, p<0.001) and at T2 (119 vs. 189, p<0.001). Patients with poor quality of recovery had lower quality of life. This fact may allow earlier and more effective interventions, in order to improve quality of life after surgery. Beside its utility after surgery, QoR-40 may be important prior to surgery to identify patients who will develop a poor quality of recovery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.
[Quality of recovery after anaesthesia measured with QoR-40: a prospective observational study].
Guimarães-Pereira, Luís; Costa, Maria; Sousa, Gabriela; Abelha, Fernando
2016-01-01
QoR-40, a 40-item questionnaire on quality of recovery from anaesthesia, has been shown to measure health status after surgery. Our aim was to evaluate the incidence of poor quality of recovery in our Post Anaesthesia Care Unit and to compare their QoR-40 scores before surgery and 3 months later. A prospective observational study was conducted in adult patients consecutively admitted from 18 June to 12 July 2012. The follow-up period was 3 months. We exclude patients submitted to cardiac surgery, neurosurgery, obstetric surgery and with a mini-mental state examination test score lower than 25. The primary endpoint was quality of recovery measured with the validated Portuguese for Portugal version of the QoR-40 before surgery (T0), 24h after surgery (T1) and 3 months after (T2). A total of 114 patients completed the study. Mean QoR-40 score was 169 and patients with poor quality of recovery were identified if their QoR-40 score was lesser than 142. This occurred in 26 patients (24%). Global median scores for patients with poor quality of recovery were lower at T0 (121 vs. 184, p<0.001), at T1 (120 vs. 177, p<0.001) and at T2 (119 vs. 189, p<0.001). Patients with poor quality of recovery had lower quality of life. This fact may allow earlier and more effective interventions, in order to improve quality of life after surgery. Beside its utility after surgery, QoR-40 may be important prior to surgery to identify patients who will develop a poor quality of recovery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.
Poor sleep quality, depression and hope before breast cancer surgery.
Mansano-Schlosser, Thalyta Cristina; Ceolim, Maria Filomena; Valerio, Teresa D
2017-04-01
This study aims to identify the predictors of poor sleep quality and the associations between depression, hope and sleep in a sample of 156 women with breast cancer prior to surgery. The care and treatment of breast cancer is among the most important scientific challenges in public health. Sleep disturbances and depression are the important complaint of cancer patients. However, they are often neglected. Patients diagnosed with breast cancer also experience prejudice, fear of death, suffering, mutilation, fear of lymphedema, as well as feelings of social devaluation leading to hopelessness Several studies point to hope as an effective strategy to help patients cope with difficulties and achieve their goals, especially patients with cancer. This is a report of baseline data extracted from a longitudinal study. Pittsburgh Sleep Quality Index, Beck Depression Inventory, and the Herth Hope Index. Data were analyzed with the Spearman's Rank Correlation test and Multiple Logistic Regression analysis. The majority of women had tumors in initial stages (78.7%), reported poor sleep quality (58.9%), and had moderate to severe or severe depression (27.2%). Significant correlations were found between hope and depression (Spearman r=-0.4341), and between sleep quality and depression (Spearman r=0.3938). Significant associations were found between poor sleep quality and pain, symptoms of menopause and depression. Depression and symptoms of menopause were independent predictors of poor sleep quality. The evaluation of sleep quality, depression and hope should be implemented in clinical practice. Increased hope lessens depression and may positively affect sleep quality, all of which improves quality of life for women with breast cancer. Copyright © 2016 Elsevier Inc. All rights reserved.
Association between Personality Traits and Sleep Quality in Young Korean Women
Kim, Han-Na; Cho, Juhee; Chang, Yoosoo; Ryu, Seungho
2015-01-01
Personality is a trait that affects behavior and lifestyle, and sleep quality is an important component of a healthy life. We analyzed the association between personality traits and sleep quality in a cross-section of 1,406 young women (from 18 to 40 years of age) who were not reporting clinically meaningful depression symptoms. Surveys were carried out from December 2011 to February 2012, using the Revised NEO Personality Inventory and the Pittsburgh Sleep Quality Index (PSQI). All analyses were adjusted for demographic and behavioral variables. We considered beta weights, structure coefficients, unique effects, and common effects when evaluating the importance of sleep quality predictors in multiple linear regression models. Neuroticism was the most important contributor to PSQI global scores in the multiple regression models. By contrast, despite being strongly correlated with sleep quality, conscientiousness had a near-zero beta weight in linear regression models, because most variance was shared with other personality traits. However, conscientiousness was the most noteworthy predictor of poor sleep quality status (PSQI≥6) in logistic regression models and individuals high in conscientiousness were least likely to have poor sleep quality, which is consistent with an OR of 0.813, with conscientiousness being protective against poor sleep quality. Personality may be a factor in poor sleep quality and should be considered in sleep interventions targeting young women. PMID:26030141
Optical properties of doped sol-gel silica glasses
NASA Astrophysics Data System (ADS)
King, Terence A.
1994-01-01
Sol-gel optical composites were developed and characterized for potential applications in optics, lasers, nonlinear optics, and optoelectronics. Post-doped xerogels were index matched by in-situ polymerization of monomers to form inorganic-organic composites of low scatter and high optical quality. Characterization of the microstructure was made by visible and IR absorption and Raman Spectroscopy and optical quality by attenuation and scatter measurement. Doping techniques were optimized using hypercritical drying and vacuum impregnation and doping distribution monitored by laser-induced fluorescence. One-tenth wavelength surfaces were formed by novel optical polishing. Organic molecular dopants were tested in laser and nonlinear systems. Initial third harmonic generation and Z-scan measurements have shown the potential for saturable absorption and optical limiting.
An adaptive optics imaging system designed for clinical use
Zhang, Jie; Yang, Qiang; Saito, Kenichi; Nozato, Koji; Williams, David R.; Rossi, Ethan A.
2015-01-01
Here we demonstrate a new imaging system that addresses several major problems limiting the clinical utility of conventional adaptive optics scanning light ophthalmoscopy (AOSLO), including its small field of view (FOV), reliance on patient fixation for targeting imaging, and substantial post-processing time. We previously showed an efficient image based eye tracking method for real-time optical stabilization and image registration in AOSLO. However, in patients with poor fixation, eye motion causes the FOV to drift substantially, causing this approach to fail. We solve that problem here by tracking eye motion at multiple spatial scales simultaneously by optically and electronically integrating a wide FOV SLO (WFSLO) with an AOSLO. This multi-scale approach, implemented with fast tip/tilt mirrors, has a large stabilization range of ± 5.6°. Our method consists of three stages implemented in parallel: 1) coarse optical stabilization driven by a WFSLO image, 2) fine optical stabilization driven by an AOSLO image, and 3) sub-pixel digital registration of the AOSLO image. We evaluated system performance in normal eyes and diseased eyes with poor fixation. Residual image motion with incremental compensation after each stage was: 1) ~2–3 arc minutes, (arcmin) 2) ~0.5–0.8 arcmin and, 3) ~0.05–0.07 arcmin, for normal eyes. Performance in eyes with poor fixation was: 1) ~3–5 arcmin, 2) ~0.7–1.1 arcmin and 3) ~0.07–0.14 arcmin. We demonstrate that this system is capable of reducing image motion by a factor of ~400, on average. This new optical design provides additional benefits for clinical imaging, including a steering subsystem for AOSLO that can be guided by the WFSLO to target specific regions of interest such as retinal pathology and real-time averaging of registered images to eliminate image post-processing. PMID:26114033
Optical Computers and Space Technology
NASA Technical Reports Server (NTRS)
Abdeldayem, Hossin A.; Frazier, Donald O.; Penn, Benjamin; Paley, Mark S.; Witherow, William K.; Banks, Curtis; Hicks, Rosilen; Shields, Angela
1995-01-01
The rapidly increasing demand for greater speed and efficiency on the information superhighway requires significant improvements over conventional electronic logic circuits. Optical interconnections and optical integrated circuits are strong candidates to provide the way out of the extreme limitations imposed on the growth of speed and complexity of nowadays computations by the conventional electronic logic circuits. The new optical technology has increased the demand for high quality optical materials. NASA's recent involvement in processing optical materials in space has demonstrated that a new and unique class of high quality optical materials are processible in a microgravity environment. Microgravity processing can induce improved orders in these materials and could have a significant impact on the development of optical computers. We will discuss NASA's role in processing these materials and report on some of the associated nonlinear optical properties which are quite useful for optical computers technology.
Nano-optomechanics with optically levitated nanoparticles
NASA Astrophysics Data System (ADS)
Neukirch, Levi P.; Vamivakas, A. Nick
2015-01-01
Nano-optomechanics is a vibrant area of research that continues to push the boundary of quantum science and measurement technology. Recently, it has been realised that the optical forces experienced by polarisable nanoparticles can provide a novel platform for nano-optomechanics with untethered mechanical oscillators. Remarkably, these oscillators are expected to exhibit quality factors approaching ?. The pronounced quality factors are a direct result of the mechanical oscillator being freed from a supporting substrate. This review provides an overview of the basic optical physics underpinning optical trapping and optical levitation experiments, it discusses a number of experimental approaches to optical trapping and finally outlines possible applications of this nano-optomechanics modality in hybrid quantum systems and nanoscale optical metrology.
Hu, Song; Yao, Jian; Liu, Meng; Luo, Ai-Ping; Luo, Zhi-Chao; Xu, Wen-Cheng
2016-05-16
The ultrafast time-stretch microscopy has been proposed to enhance the temporal resolution of a microscopy system. The optical source is a key component for ultrafast time-stretch microscopy system. Herein, we reported on the gain-guided soliton fiber laser with high-quality rectangle spectrum for ultrafast time-stretch microscopy. By virtue of the excellent characteristics of the gain-guided soliton, the output power and the 3-dB bandwidth of the stable mode-locked soliton could be up to 3 mW and 33.7 nm with a high-quality rectangle shape, respectively. With the proposed robust optical source, the ultrafast time-stretch microscopy with the 49.6 μm resolution and a scan rate of 11 MHz was achieved without the external optical amplification. The obtained results demonstrated that the gain-guided soliton fiber laser could be used as an alternative high-quality optical source for ultrafast time-stretch microscopy and will introduce some applications in fields such as biology, chemical, and optical sensing.
Longmore, Monica A.; Manning, Wendy D.; Giordano, Peggy C.; Copp, Jennifer E.
2014-01-01
Examining longitudinal data from the Toledo Adolescent Relationships Study (TARS) (n = 927), we assessed associations between physical victimization by an intimate partner, indicators of poor relationship quality, and depressive symptoms among young adult men and women in casually dating, exclusively dating, cohabiting, and marital relationships. In zero-order models, we found that physical victimization increased depressive symptoms. In multivariate models, victimization was a risk factor for depressive symptoms with the inclusion of prior depressive symptoms, family factors reflecting the intergenerational transmission of violence, sociodemographic background, and relationship characteristics including union status. Yet with the additional inclusion of indicators of poor relational quality, victimization was not a significant predictor of depressive symptoms. Arguing and poor communication influenced victimization and depressive symptoms. The associations between victimization and depressive symptoms did not differ by gender, nor were the effects of poor relationship quality on depressive symptoms conditional on gender. Thus, depressive symptoms are similarly responsive to intimate partner victimization, and for both women and men these associations were not significant with the inclusion of indicators of poor relationship quality. Findings underscored that victimization often occurs within relationship contexts characterized by a range of negative dynamics; thus multifaceted relationship-centered prevention and intervention efforts are likely to be more useful than those focusing only on negative messages about the use of aggression with an intimate partner. PMID:25131276
Examining asthma quality of care using a population-based approach
Klomp, Helena; Lawson, Joshua A.; Cockcroft, Donald W.; Chan, Benjamin T.; Cascagnette, Paul; Gander, Laurie; Jorgenson, Derek
2008-01-01
Background Asthma accounts for considerable burden on health care, but in most cases, asthma can be controlled. Quality-of-care indicators would aid in monitoring asthma management. We describe the quality of asthma care using a set of proposed quality indicators. Methods We performed a retrospective cross-sectional study using health databases in Saskatchewan, a Canadian province with a population of about 1 million people. We assessed 6 quality-of-care indicators among people with asthma: admission to hospital because of asthma; poor asthma control (high use of short-acting β-agonists, admission to hospital because of asthma or death due to asthma); no inhaled corticosteroid use among patients with poor control; at least moderate inhaled corticosteroid use among patients with poor control; high inhaled corticosteroid use and use of another preventer medication among patients with poor control; and any main preventer use among patients with poor control. We calculated crude and adjusted rates with 95% confidence intervals. We tested for differences using the χ2 test for proportions and generalized linear modelling techniques. Results In 2002/03, there were 24 616 people aged 5–54 years with asthma in Saskatchewan, representing a prevalence of 3.8%. Poor symptom control was observed in 18% of patients with asthma. Among those with poor control, 37% were not dispensed any inhaled corticosteroids, and 40% received potentially inadequate doses. Among those with poor control who were dispensed high doses of inhaled corticosteroids, 26% also used another preventer medication. Hospital admissions because of asthma were highest among those aged 6–9 years and females aged 20–44 years. Males and those in adult age groups (predominantly 20–44 years) had worse quality of care for 4 indicators examined. Interpretation Suboptimal asthma management would be improved through increased use of inhaled corticosteroids and preventer medications, and reduced reliance on short-acting β-agonist medications as recommended by consensus guidelines. PMID:18390944
Schiavetti, Benedetta; Wynendaele, Evelien; De Spiegeleer, Bart; Mbinze, Geremie J.; Kalenda, Nicodème; Marini, Roland; Melotte, Vera; Hasker, Epco; Meessen, Bruno; Ravinetto, Raffaella; Van der Elst, Josiane; Mutolo Ngeleka, Daniel
2018-01-01
Abstract. Poor-quality medicines are a threat to public health in many low- and middle-income countries, and prospective surveys are needed to inform corrective actions. Therefore, we conducted a cross-sectional survey on a sample of products used for children and available in the private market in Kinshasa, Democratic Republic Congo: amoxicillin (AX) and artemether/lumefantrine (AL), powders for suspension, and paracetamol (PC) tablets 500 mg. Overall, 417 products were covertly purchased from 61 wholesalers. To obtain a representative sample, the products were weighted on their market shares and a subset of 239 samples was randomly extracted to undergo in-depth visual inspection locally, and they were chemically assessed at two accredited laboratories in Belgium. Samples were defined of “poor-quality” if they failed to comply with at least one specification of the International Pharmacopoeia (for AL) or United States Pharmacopoeia 37 (for AX and PC). Results are reported according to the Medicine Quality Assessment Reporting Guideline. The visual inspection detected nonconformities in the aspects of antimalarial powders for suspension, and poor-quality labels across all medicine types. According to chemical analysis, 27.2% samples were of poor quality and 59.5% of AL samples were underdosed in artemether. Poor quality was more frequent for locally manufactured antimalarials (83.3%, P = 0.021; 86.4%, P = 0.022) and PC (4.8%, P = 0.000). The poor quality of the surveyed products may decrease the treatment’s efficacy and favor the development of resistances to antimalarials. It is hoped that these findings may guide the corrective actions of the Democratic Republic of Congo Regulatory Authority, which was the main partner in the research. PMID:29313479
Retinal projections in the electric catfish (Malapterurus electricus).
Ebbesson, S O; O'Donnel, D
1980-01-01
The poorly developed visual system of the electric catfish was studied with silver-degeneration methods. Retinal projections were entirely contralateral to the hypothalamic optic nucleus, the lateral geniculate nucleus, the dorsomedial optic nucleus, the pretectal nuclei including the cortical nucleus, and the optic tectum. The small size and lack of differentiation of the visual system in the electric catfish suggest a relatively small role for this sensory system in this species.
High quality adaptive optics zoom with adaptive lenses
NASA Astrophysics Data System (ADS)
Quintavalla, M.; Santiago, F.; Bonora, S.; Restaino, S.
2018-02-01
We present the combined use of large aperture adaptive lens with large optical power modulation with a multi actuator adaptive lens. The Multi-actuator Adaptive Lens (M-AL) can correct up to the 4th radial order of Zernike polynomials, without any obstructions (electrodes and actuators) placed inside its clear aperture. We demonstrated that the use of both lenses together can lead to better image quality and to the correction of aberrations of adaptive optics optical systems.
Kobashi, Hidenaga; Kamiya, Kazutaka; Yanome, Kyohei; Igarashi, Akihito; Shimizu, Kimiya
2013-01-01
To assess the longitudinal changes in optical quality including intraocular scattering in normal eyes and eyes with short tear breakup time (TBUT). We prospectively examined twenty eyes of 20 healthy subjects, and age-matched twenty eyes of 20 short TBUT subjects. The modulation transfer function (MTF) cutoff frequency, the Strehl ratio, and the objective scattering index (OSI) were quantitatively assessed using an Optical Quality Analysis System. We investigated the changes in these variables measured consecutively at the initial examination, 5, and 10 seconds without blinking. We also compared these variables in eyes with short TBUT with those in normal eyes. No significant differences in the MTF cutoff frequency, Strehl ratio, or OSI were detected over a 10-second period in normal eyes. These variables also became significantly degraded even over a 5-second period in eyes with short TBUT (p<0.01). We found significant differences in these variables at 5 and 10 seconds (p<0.05), but none immediately after the blink between normal and short TBUT eyes. Optical quality including intraocular scattering deteriorated significantly with time in eyes with short TBUT, whereas we found significant differences over a 10-second period in normal eyes. Eyes with short TBUT showed greater deterioration in optical quality after the blink than normal eyes. The longitudinal assessment of optical quality may be effective in distinguishing eyes with short TBUT from normal eyes.
Sleep quality subtypes and obesity.
Magee, Christopher A; Reddy, Prasuna; Robinson, Laura; McGregor, Alisha
2016-12-01
Poor sleep quality could be a risk factor for obesity. This article utilized a person-centered approach to investigate whether distinct sleep quality subtypes were associated with obesity directly, and indirectly via physical activity. The sample included 8,932 Australian employees who participated in the Household, Income and Labor Dynamics in Australia Survey. Structured interviews and self-report questionnaires collected information on sleep quality, obesity, and relevant demographic, health, and work-related variables. Latent class analysis identified distinct subtypes of sleep quality. General linear modeling examined the associations of sleep quality subtypes with body mass index (BMI) and waist circumference. Multicategorical mediation models examined indirect paths linking sleep quality classes with obesity via physical activity. Five distinct sleep quality subtypes were identified: Poor Sleepers (20.0%), Frequent Sleep Disturbances (19.2%), Minor Sleep Disturbances (24.5%), Long Sleepers (9.6%), and Good Sleepers (26.7%). BMI, waist circumference, and physical activity differed among the sleep quality subtypes, with similar results observed for males and females. For example, Poor Sleepers had the highest BMIs, followed by Frequent Sleep Disturbances and Minor Sleep Disturbances; Long Sleepers and Good Sleepers had the lowest BMIs. Mediation analyses indicated that low levels of physical activity linked the Poor Sleep, Frequent Sleep Disturbance, and Long Sleep classes with higher BMI. These results provide new insights into the nature of sleep quality in employees. In particular, distinct sleep quality patterns had differing associations with measures of obesity, suggesting the need for tailored workplace interventions. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Muñoz-Pareja, Maritza; Loch, Mathias Roberto; Dos Santos, Hellen Geremias; Sakay Bortoletto, Maira Sayuri; Durán González, Alberto; Maffei de Andrade, Selma
The prevalence of poor sleep quality in men and women ≥ 40 years old from the VIGICARDIO Study was determined, and sociodemographic, health, lifestyle and social capital factors associated with poor sleep quality were identified. A population-based study conducted in 2011 among 1,058 non-institutionalised individuals randomly selected from Cambé, Paraná State, Brazil. Logistic regression was used to evaluate the association between sleep quality and sociodemographic, health, lifestyle and social capital factors in men and women. The prevalence of poor sleep quality was 34% in men and 44% in women. Having bad/regular self-rated health status was a factor associated with poor sleep quality in men (OR: 1.79; 95% CI: 1.17-2.72) and women (OR: 2.43; 95% CI: 1.68-3.53). Being obese (OR: 1.67; 95% CI: 1.13-2.46), having depression (OR: 2.09; 95% CI: 1.41-3.13) and presenting temporal orientation difficulties (OR: 1.95; 95% CI: 1.08-3.52) were associated factors in women. Difficulty to understand what is explained (OR: 2.18; 95% CI: 1.16-4.09) and alcohol abuse (OR: 1.85; 95% CI: 1.21-2.83) were associated factors in men. Factors affecting sleep quality are different for men and for women. These factors should be taken into consideration when devising activities that promote good sleep quality, with a view to improving their effectiveness. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.
New options for optical quality tolerances
NASA Astrophysics Data System (ADS)
Aikens, Dave
2017-11-01
The optics community has long recognized the problems of misinterpretation of the surface quality specification and the potential for conflict1-2. Finally in 2017 there are new versions of the ISO and ANSI standards for surface imperfection tolerances which provide vastly improved alternatives to the existing options, especially the use of the US Military standard for specifying optical quality tolerances. This paper will review the existing standards in common use for specifying surface imperfections, and then describe in detail the new versions of the ISO and ANSI standards which are available in 2017. The details of the notations and inspection methods for each of the optics specifications will be provided, and the differences between the various alternatives will be discussed.
Kenney, Shannon R; Lac, Andrew; Labrie, Joseph W; Hummer, Justin F; Pham, Andy
2013-11-01
Poor mental health, sleep problems, drinking motivations, and high-risk drinking are prevalent among college students. However, research designed to explicate the interrelationships among these health risk behaviors is lacking. This study was designed to assess the direct and indirect influences of poor mental health (a latent factor consisting of depression, anxiety, and stress) to alcohol use and alcohol-related consequences through the mediators of global sleep quality and drinking motives in a comprehensive model. Participants were 1,044 heavy-drinking college students (66.3% female) who completed online surveys. A hybrid structural equation model tested hypotheses involving relations leading from poor mental health to drinking motives and poorer global sleep quality to drinking outcomes. Results showed that poor mental health significantly predicted all four subscales of drinking motivations (social, coping, conformity, and enhancement) as well as poor sleep. Most of the drinking motives and poor sleep were found to explain alcohol use and negative alcohol consequences. Poor sleep predicted alcohol consequences, even after controlling for all other variables in the model. The hypothesized mediational pathways were examined with tests of indirect effects. This is the first study to assess concomitantly the relationships among three vital health-related domains (mental health, sleep behavior, and alcohol risk) in college students. Findings offer important implications for college personnel and interventionists interested in reducing alcohol risk by focusing on alleviating mental health problems and poor sleep quality.
Knowlden, Adam P; Burns, Maranda; Harcrow, Andy; Shewmake, Meghan E
2016-03-16
Poor sleep quality is a significant public health problem. The role of nutrition in predicting sleep quality is a relatively unexplored area of inquiry. The purpose of this study was to evaluate the capacity of 10 food choice categories, sleep confounding beverages, and psychological distress to predict the sleep quality of college students. A logistic regression model comprising 10 food choice variables (healthy proteins, unhealthy proteins, healthy dairy, unhealthy dairy, healthy grains, unhealthy grains, healthy fruits and vegetables, unhealthy empty calories, healthy beverages, unhealthy beverages), sleep confounding beverages (caffeinated/alcoholic beverages), as well as psychological distress (low, moderate, serious distress) was computed to determine the capacity of the variables to predict sleep quality (good/poor). The odds of poor sleep quality were 32.4% lower for each unit of increased frequency of healthy proteins consumed (p<0.001; OR=0.676), 14.1% lower for each unit of increased frequency of healthy dairy food choices consumed (p=0.024; OR=0.859), 13.1% higher for each unit of increased frequency of empty calorie food choices consumed (p=0.003; OR=1.131), and 107.3% higher for those classified in the moderate psychological distress (p=0.016; OR=2.073). Collectively, healthy proteins, healthy dairy, unhealthy empty calories, and moderate psychological distress were moderately predictive of sleep quality in the sample (Nagelkerke R2=23.8%). Results of the study suggested higher frequency of consumption of healthy protein and healthy dairy food choices reduced the odds of poor sleep quality, while higher consumption of empty calories and moderate psychological distress increased the odds of poor sleep quality.
Sekine, M; Tatsuse, T; Cable, N; Chandola, T; Marmot, M
2014-09-01
This study aimed to evaluate (i) whether work, family, behavioral and sleep quality characteristics differ among individuals with different time in bed (TIB), and (ii) whether and how much the U-shaped associations between TIB and health can be explained by these characteristics. Participants were 3510 employees (2371 males and 1139 females) aged 20-65 years working in local government in Japan. They completed a questionnaire regarding work, family, and behavioral characteristics. Sleep quality and physical and mental functioning were evaluated using the Pittsburgh Sleep Quality Index and the Short Form 36. High job demands, long work hours, and high work-family conflict were more prevalent among those with short TIB. Those with long TIB had daily drinking habits. Whereas those with short TIB had poor sleep, mainly due to poor subjective sleep quality and daytime dysfunction, those with long TIB had poor sleep, mainly due to long sleep latency, poor sleep efficiency and sleep disturbances. The U-shaped associations between TIB and poor physical and mental health, with the best health observed in those spending ~8 h in bed, weakened considerably after adjustment for sleep quality, followed by work and family characteristics. After adjusting for behavioral characteristics and long-standing illnesses, the associations hardly changed. The U-shaped associations between TIB and health may be explained by U-shaped associations between TIB and poor sleep and psychosocial stress in work and family life. Copyright © 2014 Elsevier B.V. All rights reserved.
Marital Quality as a Moderator of the Effects of Poor Vision on Quality of Life Among Older Adults
2011-01-01
Objectives. This study assessed the moderating role of marital quality in the effects of subjective and objective vision on functional limitations, social isolation, and depressive symptomatology. Method. Data from 738 married older adults drawn from a probability-based representative sample of elders residing in the United States were used. Assessments included subjective and objective vision, marital quality variables (relationship satisfaction, supportive spouse behaviors, and free time spent with one’s spouse), and three aspects of quality of life (functional limitations, social isolation, and depressive symptomatology). Results. Moderated regression analyses found that relationship satisfaction and supportive spouse behaviors moderated the effects of poor self-reported vision on functional limitations and depressive symptoms and the effects of poor visual acuity on functional limitations. As hypothesized, poorer vision was unrelated to functional limitations and depressive symptoms in more satisfying marriages but predicted higher levels of both outcomes in less satisfying marriages. Contrary to expectations, higher levels of supportive spouse behaviors were associated with more functional limitations in respondents who reported poorer subjective and objective vision. Discussion. A marriage that is highly satisfying can mitigate the adverse effects of poor vision on functional limitations and depressive symptomatology in late life. The moderating role of supportive spouse behaviors in the link between poor vision and quality of life is less intuitive, however. Whereas relationship satisfaction may operate as a traditional buffer in the context of poor vision, supportive spouse behaviors may increase in response to or be ineffective in this context. PMID:21840838
Evans, Subhadra; Djilas, Vesna; Seidman, Laura C; Zeltzer, Lonnie K; Tsao, Jennie C I
2017-09-01
Sleep problems have been identified as a potential antecedent of chronic pain and pain-related disability in pediatric populations. In adult studies, affect has been implicated in these relationships. This study sought to better understand the relationships between sleep quality, negative and positive affect, and pain and functioning in children with chronic pain. Participants included 213 children and adolescents (aged 7-17 years) presenting to a tertiary pain clinic with chronic pain. Children completed questionnaires measuring sleep quality, positive and negative affect, pain intensity, and functional disability. Results indicated that 74% of children reported disordered sleeping and that poor sleep quality was significantly associated with increased pain, disability, negative affect, and decreased positive affect. Our hypotheses were partially supported, with negative affect (but not positive affect) mediating the relationship between poor sleep and increased pain; and positive as well as negative affect mediating the relationship between poor sleep and increased functional disability. There was no evidence for affect as a moderator. This study adds to the growing literature demonstrating the effect of poor sleep quality on children's pain and functioning, highlighting the need to develop further longitudinal research to confirm the causal roles of these variables. This article examines the relationship between poor sleep quality, affect (negative as well as positive), pain, and disability in children with chronic pain. The findings have the potential to better understand the processes involved in how poor sleep may lead to increased pain and pain-related disability. Copyright © 2017 American Pain Society. All rights reserved.
Optic disc coloboma in two nigerian siblings: Case report and review of literature.
Babalola, Y O; Olawoye, O O; Idam, P O
2017-11-01
We report two cases of bilateral asymmetric optic disc coloboma (ODC) in siblings. The index patient is a 9-year-old Nigerian girl with severe cognitive deficit who presented with a poor vision of 3 years' duration. She had a history of childhood febrile convulsions and delayed developmental milestones. Her visual acuity could not be assessed because she had a cognitive deficit and expressive aphasia. Ocular examination revealed a very large excavated right optic disc with only a strip of remnant neuro-retinal rim superiorly, and a smaller left optic disc with inferior disc excavation, superior wedge of the pink neuro-retinal rim as well as a temporal optic disc pit. No systemic features of syndromes associated with ODCs and intellectual disability were present in both patients. The younger sibling an 8-year-old girl later presented to the eye clinic with a 5-month history of poor vision in the left eye. Ocular examination revealed visual acuity of 6/6 in the right eye and counting fingers in the left eye. Dilated binocular indirect ophthalmoscopy revealed a right large excavated colobomatous disc and a left small disc with infero-temporal disc coloboma.
Reconstructing the 1935 Columbia River Gorge: A Topographic and Orthophoto Experiment
NASA Astrophysics Data System (ADS)
Fonstad, M. A.; Major, J. H.; O'Connor, J. E.; Dietrich, J. T.
2017-12-01
The last decade has seen a revolution in the mapping of rivers and near-river environments. Much of this has been associated with a new type of photogrammetry: structure from motion (SfM) and multi-view stereo techniques. Through SfM, 3D surfaces are reconstructed from nonstructured image groups with poorly calibrated cameras whose locations need not be known. Modern SfM imaging is greatly improved by careful flight planning, well-planned ground control or high-precision direct georeferencing, and well-understood camera optics. The ease of SfM, however, begs the question: how well does it work on archival photos taken without the foreknowledge of SfM techniques? In 1935, the Army Corps of Engineers took over 800 vertical aerial photos for a 160-km-long stretch of the Columbia River Gorge and adjacent areas in Oregon and Washington. These photos pre-date completion of three hydroelectric dams and reservoirs in this reach, and thus provide rich information on the historic pre-dam riverine, geologic, and cultural environments. These photos have little to no metadata associated with them, such as camera calibration reports, so traditional photogrammetry techniques are exceeding difficult to apply. Instead, we apply SfM to these archival photos, and test the resulting digital elevation model (DEM) against lidar data for features inferred to be unchanged in the past 80 years. Few, if any, of the quality controls recommended for SfM are available for these 1935 photos; they are scanned paper positives with little overlap taken with an unknown optical system in high altitude flight paths. Nevertheless, in almost all areas, the SfM analysis produced a high quality orthophoto of the gorge with low horizontal errors - most better than a few meters. The DEM created looks highly realistic, and in many areas has a vertical error of a few meters. However, the vertical errors are spatially inconsistent, with some wildly large, likely because of the many poorly constrained links in the image analysis chain. Nevertheless, products from this experiment are still highly useful, especially the orthophotographs. In areas where supplementary terrain data can be gleaned, the DEM products may also be useful for further analysis.
NASA Astrophysics Data System (ADS)
McCarthy, M. C.; Raffuse, S. M.; Dewinter, J. L.; Lurmann, F.; Craig, K. J.; Fruin, S.
2010-12-01
Current methods for estimating acute exposure to high levels of air pollution (e.g., particles, CO, NOx, aldehydes) during fire events require spatial interpolation over the study area using concentrations at central air quality monitors to represent the population of interest. This may inaccurately represent the magnitude of exposure because pollutant concentrations vary widely depending on the location of the fire plume, vertical mixing, and prevailing winds dispersing the pollutant. Remotely sensed datasets, such as aerosol optical depth (AOD) from the NASA MODIS instrument, can provide greater spatial coverage than ground-based air quality monitors. Past studies have shown positive correlations between AOD, a measure of aerosols in an atmospheric column, and ground-level measurements of PM2.5 and PM10 concentrations. However, current standard AOD products are not sufficient for assessing intra-urban variability due to the low spatial resolution (e.g., 10x10 km for MODIS) of datasets. In addition such products typically perform poorly with very dense smoke in the atmosphere and over reflective, semi-arid land surfaces such as southern California. A highly resolved AOD product (500m resolution) was developed for southern California during the October 2007 fires using radiance data obtained from the National Aeronautics and Space Administration (NASA) MODIS instrument. AOD was calculated at 0.55µm wavelength using a unique algorithm tailored to the southern California region and for an atmosphere dominated by biomass burning aerosols. The AOD product was compared with column measurements of AOD from surface-based AERONET sites. AOD was not predictive of surface PM during the October 2007 fires when compared to surface PM concentrations throughout southern California; R-square correlation coefficients were low. However, the relationship varied during the time period studied: correlations were weak early in the event (0.02) but improved during the later days of the event (0.3). Heavy dust episodes early in the fire event were poorly represented by the biomass-specific aerosol optical properties model. In addition, lofted smoke plumes from active fires did not mix down to the surface, resulting in high AOD column estimates and low surface PM concentrations. The aerosol was more dispersed later in the event; elevated surface PM concentrations were coincident with moderate AOD values. The case study demonstrates the challenges in using remote measurements in quantifying surface concentrations during active fire events in areas of complex terrain.
Mhaskar, Rahul; Djulbegovic, Benjamin; Magazin, Anja; Soares, Heloisa P; Kumar, Ambuj
2012-06-01
To assess whether the reported methodological quality of randomized controlled trials (RCTs) reflects the actual methodological quality and to evaluate the association of effect size (ES) and sample size with methodological quality. Systematic review. This is a retrospective analysis of all consecutive phase III RCTs published by eight National Cancer Institute Cooperative Groups up to 2006. Data were extracted from protocols (actual quality) and publications (reported quality) for each study. Four hundred twenty-nine RCTs met the inclusion criteria. Overall reporting of methodological quality was poor and did not reflect the actual high methodological quality of RCTs. The results showed no association between sample size and actual methodological quality of a trial. Poor reporting of allocation concealment and blinding exaggerated the ES by 6% (ratio of hazard ratio [RHR]: 0.94; 95% confidence interval [CI]: 0.88, 0.99) and 24% (RHR: 1.24; 95% CI: 1.05, 1.43), respectively. However, actual quality assessment showed no association between ES and methodological quality. The largest study to date shows that poor quality of reporting does not reflect the actual high methodological quality. Assessment of the impact of quality on the ES based on reported quality can produce misleading results. Copyright © 2012 Elsevier Inc. All rights reserved.
Thermodynamic reactivity, growth and characterization of mercurous halide crystals
NASA Technical Reports Server (NTRS)
Singh, N. B.; Gottlieb, M.; Henningsen, T.; Hopkins, R. H.; Mazelsky, R.; Singh, M.; Glicksman, M. E.; Paradies, C.
1992-01-01
Thermodynamic calculations were carried out for the Hg-X-O system (X = Cl, Br, I) to identify the potential sources of contamination and relative stability of oxides and oxy-halide phases. The effect of excess mercury vapor pressure on the optical quality of mercurous halide crystal was studied by growing several mercurous chloride crystals from mercury-rich composition. The optical quality of crystals was examined by birefringence interferometry and laser scattering studies. Crystals grown in slightly mercury-rich composition showed improved optical quality relative to stoichiometric crystals.
NASA Technical Reports Server (NTRS)
Hulcher, Anthony Bruce; McGowan, David M.; Grimsley, Brian W.; Johnston, Norman J.; Gordon, Gail H. (Technical Monitor)
2001-01-01
Two 61-cm-diameter eight-ply quasi-isotropic IM7/PEEK cylindrical shells were fabricated by automated fiber placement the NASA Langley Research Center using only infrared radiant heat to preheat the substrate and incoming composite uni-tape. The shells were characterized by ultrasonic c-scans for overall consolidation quality, and by optical microscopy and acid digestion for void content. Compression tests were also performed. Although the material used in the study was of generally poor quality due to numerous splits and dry fiber regions, the process was able to achieve a net reduction in void content in the as-placed component. Microscopy of the composite shells revealed well-consolidated, void-free interfaces. The two cylinders were then tested in uni-axial compression in a 1334 kN-capacity hydraulic test machine until buckling occurred. A geometrically nonlinear finite element analysis was conducted, and the differences between the predicted and measured values were 18.0 and 25.8%, respectively. Inclusion of measured imperfections of the cylinder into the analysis is expected to reduce these differences.
Wei, Fu; Nie, Guanghui; Zhou, Bo; Wang, Liang; Ma, Yifei; Peng, Suwan; Ou, Songfeng; Qin, Jian; Zhang, Li'e; Li, Shu; Zou, Ruosi; Zeng, Xiaoyun; Zhang, Zhiyong; Zou, Yunfeng
2017-08-01
Poor sleep quality is an important symptom of many medical or psychiatric disorders. However, the impact of cooking oil fumes (COFs) on sleep quality has not been studied. This population-based cross-sectional study was conducted to examine the association between COFs of Chinese household cooking and sleep quality. Individual sleep quality assessment was completed in 2197 participants with an average age of 37.52 years, through Pittsburgh Sleep Quality Index (PSQI). Information about their cooking practice were also collected by self-reported questionnaire. As an internal biomarker of COFs, urinary 1-hydroxypyrene (1-HOP) (n = 562) was further measured using high-performance liquid chromatography. Binary logistic regression models were performed to evaluate the association between exposure to COFs and individual sleep quality. We found that, subjective poor kitchen ventilation, preheating oil to smoking, and cooking for over 30 minutes were positively associated with overall poor sleep quality (global PSQI score >5) [odds ratio (OR) = 1.75, 95% confidence interval (CI) = 1.43-2.16; 1.25, (1.03-1.52); 1.42, (1.15-1.76), respectively]. After adjusting for potential confounders, subjective poor kitchen ventilation still tend to increase the risk of long sleep latency, sleep disturbances, and daytime dysfunction [OR = 1.37, 95% CI = 1.09-1.73; 1.91, (1.39-2.61); 1.54, (1.23-1.93), respectively]. Similar results were observed in participants who preheated oil to smoking [OR = 1.36, 95% CI = 1.08-1.72; 1.55, (1.14-2.14); 1.25, (1.02-1.55), respectively] and cooked for over 30 minutes [OR = 1.34, 95% CI = 1.05-1.72; 1.46, (1.03-2.06); 1.36, (1.08-1.72), respectively]. Furthermore, high urinary 1-HOP level was also positively associated with overall poor sleep quality (OR = 2.30, 95% CI = 1.31-4.05). The results indicated that exposure to COFs from Chinese household cooking may be a risk factor for poor sleep quality among middle-aged Chinese population. Copyright © 2017 Elsevier Ltd. All rights reserved.
Rodrigues, Alex Rua; Trufelli, Damila Cristina; Fonseca, Fernando; de Paula, Larissa Carvalho; Giglio, Auro Del
2016-12-01
To assess which laboratory and clinical factors are associated with fatigue in patients with terminal cancer. We evaluated 51 patients with advanced incurable solid tumors using the Chalder Fatigue Questionnaire (CFQ) and the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) scale for fatigue; the Pittsburgh Sleep Quality Index (PSQI-BR) for sleep quality; the Hospital Anxiety and Depression Scale (HADS) for anxiety and depression; the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire, Version 3.0 (QLQ C-30); and Functional Assessment of Cancer Therapy (FACT) for quality of life. We also analyzed several inflammatory markers and the modified Glasgow prognostic score (mGPS). We observed severe fatigue in 19 (38%) patients (FACIT-F score >36). There was a significant correlation between fatigue as evaluated by the CFQ and quality of sleep and between the CFQ mental fatigue subscale scores and TNF-α level. When fatigue was evaluated using the FACIT-F scale, we observed a significant association between fatigue and anxiety/depression, quality of sleep, mGPS, and hemoglobin levels. Fatigue measured both with the CFQ and FACIT-F scale correlated with poor quality of life according to the EORTC QLQ C-30. In patients with advanced cancer, fatigue is a common symptom associated with the presence of inflammation, poor quality of sleep, depression/anxiety, and poor quality of life. © The Author(s) 2015.
Impact of contact lens zone geometry and ocular optics on bifocal retinal image quality
Bradley, Arthur; Nam, Jayoung; Xu, Renfeng; Harman, Leslie; Thibos, Larry
2014-01-01
Purpose To examine the separate and combined influences of zone geometry, pupil size, diffraction, apodisation and spherical aberration on the optical performance of concentric zonal bifocals. Methods Zonal bifocal pupil functions representing eye + ophthalmic correction were defined by interleaving wavefronts from separate optical zones of the bifocal. A two-zone design (a central circular inner zone surrounded by an annular outer-zone which is bounded by the pupil) and a five-zone design (a central small circular zone surrounded by four concentric annuli) were configured with programmable zone geometry, wavefront phase and pupil transmission characteristics. Using computational methods, we examined the effects of diffraction, Stiles Crawford apodisation, pupil size and spherical aberration on optical transfer functions for different target distances. Results Apodisation alters the relative weighting of each zone, and thus the balance of near and distance optical quality. When spherical aberration is included, the effective distance correction, add power and image quality depend on zone-geometry and Stiles Crawford Effect apodisation. When the outer zone width is narrow, diffraction limits the available image contrast when focused, but as pupil dilates and outer zone width increases, aberrations will limit the best achievable image quality. With two-zone designs, balancing near and distance image quality is not achieved with equal area inner and outer zones. With significant levels of spherical aberration, multi-zone designs effectively become multifocals. Conclusion Wave optics and pupil varying ocular optics significantly affect the imaging capabilities of different optical zones of concentric bifocals. With two-zone bifocal designs, diffraction, pupil apodisation spherical aberration, and zone size influence both the effective add power and the pupil size required to balance near and distance image quality. Five-zone bifocal designs achieve a high degree of pupil size independence, and thus will provide more consistent performance as pupil size varies with light level and convergence amplitude. PMID:24588552
Association of Poor Subjective Sleep Quality with Suicidal Ideation among Pregnant Peruvian Women
Gelaye, Bizu; Barrios, Yasmin V.; Zhong, Qiu-Yue; Rondon, Marta B.; Borba, Christina P.C.; Sánchez, Sixto E.; Henderson, David C.; Williams, Michelle A.
2015-01-01
Objective To examine the independent and joint relationships of poor subjective sleep quality, and antepartum depression with suicidal ideation among pregnant women. Methods A cross-sectional study was conducted among 641 pregnant women attending prenatal care clinics in Lima, Peru. Antepartum depression and suicidal ideation were assessed using the Patient Health Questionnaire-9 (PHQ-9) scale. Antepartum subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Logistic regression procedures were performed to estimate odds ratios (aOR) and 95% confidence intervals (95% CI) adjusted for confounders. Results Overall, the prevalence of suicidal ideation in this cohort was 16.8% and poor subjective sleep quality was more common among women endorsing suicidal ideation as compared to their counterparts who did not (47.2%vs.24.8%, p<0.001). After adjustment for confounders including maternal depression, poor subjective sleep quality (defined using the recommended criteria of PSQI global score of >5vs. ≤5) was associated with a 1.7-fold increased odds of suicidal ideation (aOR=1.67; 95%CI 1.02–2.71). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in an 18% increase in odds for suicidal ideation, even after adjusting for depression (aOR=1.18; 95%CI 1.08–1.28). Women with both poor subjective sleep quality and depression had a 3.5-fold increased odds of suicidal ideation (aOR=3.48; 95%CI 1.96–6.18) as compared with those who had neither risk factor. Conclusion Poor subjective sleep quality was associated with increased odds of suicidal ideation. Replication of these findings may promote investments in studies designed to examine the efficacy of sleep-focused interventions to treat pregnant women with sleep disorders and suicidal ideation. PMID:25983188
Sleep Duration and Quality in Pregnant Women: A Cross-Sectional Survey in China.
Xu, Xianglong; Liu, Dengyuan; Zhang, Zhangyi; Sharma, Manoj; Zhao, Yong
2017-07-20
Objectives: Good maternal health and fetal development require sufficient and good quality of sleep during pregnancy. This study investigated sleep duration and quality in pregnant women, assessing factors with possibly influence on sleep. Method: A cross-sectional survey was conducted on pregnant women between June and August in 2015 in 16 hospitals in five provinces in China. A total of 2345 pregnant women aged 18 years and older were surveyed. Insufficient sleeping duration was defined as sleeping of less than 7 h per day. Excessive sleep duration was defined as sleeping of more than 9 h per day. Results: A total of 561 (23.9%) participants reported insufficient sleeping duration, whereas 485 (20.9%) claimed excessive sleep duration. A total of 358 (15.2%) of pregnant women reported problems regarding sleep quality. Compared to pregnant women with sufficient sleeping duration, those with insufficient sleeping duration were prone to have poor sleep quality, whereas those with excessive sleeping duration featured low possibility of poor sleep quality. High-risk groups of insufficient sleep duration include women of Han nationality, with siblings, in their first trimester of pregnancy, receiving care in low-capacity/quality hospital settings, and with daily or 1-3 days of secondhand smoke exposure. High-risk groups of excessive sleep duration include women living in rural areas, unemployed, in their third trimester of pregnancy, and receiving care in medium-capacity/quality hospital settings. High-risk groups of poor sleep quality include women of non-Han nationality, low income level, in their third trimester of pregnancy, and with insufficient sleep duration. Conclusions: Insufficient/excessive sleep duration and poor sleep quality commonly occur during pregnancy in China. Findings provide a better understanding of the influencing factors of insufficient/excessive sleep duration and poor quality of sleep. These findings have some implications for future interventions on sleep among pregnant women.
Sleep Duration and Quality in Pregnant Women: A Cross-Sectional Survey in China
Liu, Dengyuan; Zhang, Zhangyi; Zhao, Yong
2017-01-01
Objectives: Good maternal health and fetal development require sufficient and good quality of sleep during pregnancy. This study investigated sleep duration and quality in pregnant women, assessing factors with possibly influence on sleep. Method: A cross-sectional survey was conducted on pregnant women between June and August in 2015 in 16 hospitals in five provinces in China. A total of 2345 pregnant women aged 18 years and older were surveyed. Insufficient sleeping duration was defined as sleeping of less than 7 h per day. Excessive sleep duration was defined as sleeping of more than 9 h per day. Results: A total of 561 (23.9%) participants reported insufficient sleeping duration, whereas 485 (20.9%) claimed excessive sleep duration. A total of 358 (15.2%) of pregnant women reported problems regarding sleep quality. Compared to pregnant women with sufficient sleeping duration, those with insufficient sleeping duration were prone to have poor sleep quality, whereas those with excessive sleeping duration featured low possibility of poor sleep quality. High-risk groups of insufficient sleep duration include women of Han nationality, with siblings, in their first trimester of pregnancy, receiving care in low-capacity/quality hospital settings, and with daily or 1–3 days of secondhand smoke exposure. High-risk groups of excessive sleep duration include women living in rural areas, unemployed, in their third trimester of pregnancy, and receiving care in medium-capacity/quality hospital settings. High-risk groups of poor sleep quality include women of non-Han nationality, low income level, in their third trimester of pregnancy, and with insufficient sleep duration. Conclusions: Insufficient/excessive sleep duration and poor sleep quality commonly occur during pregnancy in China. Findings provide a better understanding of the influencing factors of insufficient/excessive sleep duration and poor quality of sleep. These findings have some implications for future interventions on sleep among pregnant women. PMID:28726747
Fabrication of Silica Ultra High Quality Factor Microresonators
Maker, Ashley J.; Armani, Andrea M.
2012-01-01
Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the quality factor (Q) of the cavity, can be in excess of 500ns for cavities with Q factors above 100 million. As a result of their low material losses, silica microcavities have demonstrated some of the longest photon lifetimes to date1-2. Since a portion of the circulating light extends outside the resonator, these devices can also be used to probe the surroundings. This interaction has enabled numerous experiments in biology, such as single molecule biodetection and antibody-antigen kinetics, as well as discoveries in other fields, such as development of ultra-low-threshold microlasers, characterization of thin films, and cavity quantum electrodynamics studies.3-7 The two primary silica resonant cavity geometries are the microsphere and the microtoroid. Both devices rely on a carbon dioxide laser reflow step to achieve their ultra-high-Q factors (Q>100 million).1-2,8-9 However, there are several notable differences between the two structures. Silica microspheres are free-standing, supported by a single optical fiber, whereas silica microtoroids can be fabricated on a silicon wafer in large arrays using a combination of lithography and etching steps. These differences influence which device is optimal for a given experiment. Here, we present detailed fabrication protocols for both types of resonant cavities. While the fabrication of microsphere resonant cavities is fairly straightforward, the fabrication of microtoroid resonant cavities requires additional specialized equipment and facilities (cleanroom). Therefore, this additional requirement may also influence which device is selected for a given experiment. Introduction An optical resonator efficiently confines light at specific wavelengths, known as the resonant wavelengths of the device. 1-2 The common figure of merit for these optical resonators is the quality factor or Q. This term describes the photon lifetime (τo) within the resonator, which is directly related to the resonator's optical losses. Therefore, an optical resonator with a high Q factor has low optical losses, long photon lifetimes, and very low photon decay rates (1/τo). As a result of the long photon lifetimes, it is possible to build-up extremely large circulating optical field intensities in these devices. This very unique property has allowed these devices to be used as laser sources and integrated biosensors.10 A unique sub-class of resonators is the whispering gallery mode optical microcavity. In these devices, the light is confined in circular orbits at the periphery. Therefore, the field is not completely confined within the device, but evanesces into the environment. Whispering gallery mode optical cavities have demonstrated some of the highest quality factors of any optical resonant cavity to date.9,11 Therefore, these devices are used throughout science and engineering, including in fundamental physics studies and in telecommunications as well as in biodetection experiments. 3-7,12 Optical microcavities can be fabricated from a wide range of materials and in a wide variety of geometries. A few examples include silica and silicon microtoroids, silicon, silicon nitride, and silica microdisks, micropillars, and silica and polymer microrings.13-17 The range in quality factor (Q) varies as dramatically as the geometry. Although both geometry and high Q are important considerations in any field, in many applications, there is far greater leverage in boosting device performance through Q enhancement. Among the numerous options detailed previously, the silica microsphere and the silica microtoroid resonator have achieved some of the highest Q factors to date.1,9 Additionally, as a result of the extremely low optical loss of silica from the visible through the near-IR, both microspheres and microtoroids are able to maintain their Q factors over a wide range of testing wavelengths.18 Finally, because silica is inherently biocompatible, it is routinely used in biodetection experiments. In addition to high material absorption, there are several other potential loss mechanisms, including surface roughness, radiation loss, and contamination loss.2 Through an optimization of the device size, it is possible to eliminate radiation losses, which arise from poor optical field confinement within the device. Similarly, by storing a device in an appropriately clean environment, contamination of the surface can be minimized. Therefore, in addition to material loss, surface scattering is the primary loss mechanism of concern.2,8 In silica devices, surface scattering is minimized by using a laser reflow technique, which melts the silica through surface tension induced reflow. While spherical optical resonators have been studied for many years, it is only with recent advances in fabrication technologies that researchers been able to fabricate high quality silica optical toroidal microresonators (Q>100 million) on a silicon substrate, thus paving the way for integration with microfluidics.1 The present series of protocols details how to fabricate both silica microsphere and microtoroid resonant cavities. While silica microsphere resonant cavities are well-established, microtoroid resonant cavities were only recently invented.1 As many of the fundamental methods used to fabricate the microsphere are also used in the more complex microtoroid fabrication procedure, by including both in a single protocol it will enable researchers to more easily trouble-shoot their experiments. PMID:22805153
ERIC Educational Resources Information Center
Gilbert, Steven P.; Weaver, Cameron C.
2010-01-01
Both sleep deprivation and poor sleep quality are prominent in American society, especially in college student populations. Sleep problems are often a primary disorder rather than secondary to depression. The purpose of the present study was to determine if sleep deprivation and/or poor sleep quality in a sample of nondepressed university students…
Pedagogy, Accountability, and Perceptions of Quality by Type of Higher Education in Egypt and Jordan
ERIC Educational Resources Information Center
Assaad, Ragui; Badawy, Eslam; Krafft, Caroline
2016-01-01
A number of reasons have been proposed for the poor quality of higher education in the Arab world, including the poor incentive structures of public higher education institutions. The expansion of private higher education has been hailed as an important part of enhancing incentives and thus improving education quality. However, it is not clear…
Measuring the Cost of Quality in Higher Education: A Faculty Perspective
ERIC Educational Resources Information Center
Ruhupatty, LeRoy; Maguad, Ben A.
2015-01-01
Most critical activities in colleges and universities are driven by financial considerations. It is thus important that revenues are found to support these activities or ways identified to streamline costs. One way to cut cost is to improve the efficiency of schools to address the issue of poor quality. In this paper, the cost of poor quality in…
The role of optical flow in automated quality assessment of full-motion video
NASA Astrophysics Data System (ADS)
Harguess, Josh; Shafer, Scott; Marez, Diego
2017-09-01
In real-world video data, such as full-motion-video (FMV) taken from unmanned vehicles, surveillance systems, and other sources, various corruptions to the raw data is inevitable. This can be due to the image acquisition process, noise, distortion, and compression artifacts, among other sources of error. However, we desire methods to analyze the quality of the video to determine whether the underlying content of the corrupted video can be analyzed by humans or machines and to what extent. Previous approaches have shown that motion estimation, or optical flow, can be an important cue in automating this video quality assessment. However, there are many different optical flow algorithms in the literature, each with their own advantages and disadvantages. We examine the effect of the choice of optical flow algorithm (including baseline and state-of-the-art), on motionbased automated video quality assessment algorithms.
Comans, Tracy A; Currin, Michelle L; Brauer, Sandra G; Haines, Terry P
2011-01-01
To identify factors contributing to reduced quality of life and increased caregiver strain in an older population referred to a community rehabilitation team and to recommend service delivery models. Analytical cross-sectional study arising from baseline assessments from 107 subjects drawn from a randomised controlled trial of community rehabilitation service delivery models. A community rehabilitation team based in Brisbane, Queensland, Australia. Primary outcome variables include quality of life (EQ-5D & VAS) and Carer Strain Index. Predictor variables include participation in functional activities, history of falls, number of medications, number of co-morbidities, depression, environmental hazards, physical function and nutrition. Association between variables assessed using linear regression. Major factors contributing to reduced quality of life were having reduced participation in daily activities, depression, and having poor vision. Having poor nutrition and no longer driving also contributed to poor quality of life. The major factor contributing to increased caregiver strain was reduced participation in daily activities by the older person. Community rehabilitation services working with older populations must adopt models of care that screen for and address a wide range of factors that contribute to poor quality of life and caregiver strain.
Micro-optical fabrication by ultraprecision diamond machining and precision molding
NASA Astrophysics Data System (ADS)
Li, Hui; Li, Likai; Naples, Neil J.; Roblee, Jeffrey W.; Yi, Allen Y.
2017-06-01
Ultraprecision diamond machining and high volume molding for affordable high precision high performance optical elements are becoming a viable process in optical industry for low cost high quality microoptical component manufacturing. In this process, first high precision microoptical molds are fabricated using ultraprecision single point diamond machining followed by high volume production methods such as compression or injection molding. In the last two decades, there have been steady improvements in ultraprecision machine design and performance, particularly with the introduction of both slow tool and fast tool servo. Today optical molds, including freeform surfaces and microlens arrays, are routinely diamond machined to final finish without post machining polishing. For consumers, compression molding or injection molding provide efficient and high quality optics at extremely low cost. In this paper, first ultraprecision machine design and machining processes such as slow tool and fast too servo are described then both compression molding and injection molding of polymer optics are discussed. To implement precision optical manufacturing by molding, numerical modeling can be included in the future as a critical part of the manufacturing process to ensure high product quality.
Guest Editorial Precision Surface Metrology
NASA Astrophysics Data System (ADS)
Wyant, James C.
1984-08-01
During the past two decades there have been many changes in precision surface metrology. The introduction of the laser and the large computer during the 1960s and 1970s produced many changes in testing capabilities and requirements. Several commercial interferometers became available in the 1970s, enabling people who were not necessarily experts in interferometry to use interferometers to produce better optics. Since both buyers and sellers could test optics, the quality of the optics manufactured and sold improved greatly. If a person ordered 1/10 wave optics, he would probably get 1/10 wave or better optics; if he got optics of lower quality, he would know it, and he could prove it and return it.
Atmospheric turbulence and sensor system effects on biometric algorithm performance
NASA Astrophysics Data System (ADS)
Espinola, Richard L.; Leonard, Kevin R.; Byrd, Kenneth A.; Potvin, Guy
2015-05-01
Biometric technologies composed of electro-optical/infrared (EO/IR) sensor systems and advanced matching algorithms are being used in various force protection/security and tactical surveillance applications. To date, most of these sensor systems have been widely used in controlled conditions with varying success (e.g., short range, uniform illumination, cooperative subjects). However the limiting conditions of such systems have yet to be fully studied for long range applications and degraded imaging environments. Biometric technologies used for long range applications will invariably suffer from the effects of atmospheric turbulence degradation. Atmospheric turbulence causes blur, distortion and intensity fluctuations that can severely degrade image quality of electro-optic and thermal imaging systems and, for the case of biometrics technology, translate to poor matching algorithm performance. In this paper, we evaluate the effects of atmospheric turbulence and sensor resolution on biometric matching algorithm performance. We use a subset of the Facial Recognition Technology (FERET) database and a commercial algorithm to analyze facial recognition performance on turbulence degraded facial images. The goal of this work is to understand the feasibility of long-range facial recognition in degraded imaging conditions, and the utility of camera parameter trade studies to enable the design of the next generation biometrics sensor systems.
NASA Astrophysics Data System (ADS)
Kazadzis, Stelios; Kouremeti, Natalia; Nyeki, Stephan; Gröbner, Julian; Wehrli, Christoph
2018-02-01
The World Optical Depth Research Calibration Center (WORCC) is a section within the World Radiation Center at Physikalisches-Meteorologisches Observatorium (PMOD/WRC), Davos, Switzerland, established after the recommendations of the World Meteorological Organization for calibration of aerosol optical depth (AOD)-related Sun photometers. WORCC is mandated to develop new methods for instrument calibration, to initiate homogenization activities among different AOD networks and to run a network (GAW-PFR) of Sun photometers. In this work we describe the calibration hierarchy and methods used under WORCC and the basic procedures, tests and processing techniques in order to ensure the quality assurance and quality control of the AOD-retrieved data.
Tuning optical radiation for visual and nonvisual impact
NASA Astrophysics Data System (ADS)
Royer, Michael P.
2011-12-01
Spectral tuning---the allocation of radiant energy emitted by a lamp---is a fundamental element of illuminating engineering. Proper placement of optical radiation allows for reduced energy consumption, increased brightness perception, and improved color rendition. It can also result in lamps that have a greater impact on nonvisual human functions such as circadian rhythms, sleep, mood, and cognition. For an architectural lighting system, careful consideration must be given to all of these areas; recent advancements in understanding nonvisual photoreception must be balanced with the traditional emphasis on visual quality and energy efficiency. The three research projects described herein investigated spectral tuning by examining the effects of optical radiation or seeking ideal spectral power distributions. In all three cases, emphasis was placed on developing an architectural lighting system based on red, green, and blue (RGB) light emitting diodes (LEDs) that is capable of providing maximum stimulation to nonvisual systems while maintaining visual quality standards. In particular, the elderly were considered as a target population because they have an increased risk of developing disorders linked to illumination deficits. The three endeavors can be summarized as follows: Light Therapy for Seniors in Long-term Care AIM: To examine the effect of optical radiation on circadian rhythms, sleep, mood, and cognition for frail elderly in a long-term care environment. METHODOLOGY: A double-blind, placebo-controlled clinical trial of light therapy was conducted using circadian-effective short-wavelength (blue) optical radiation to treat a sample of residents recruited for participation without bias for existing medical diagnoses. KEY FINDINGS: Light therapy treatment improved cognitive functioning compared to placebo but no changes were detected in nighttime sleep statistics, reports of daytime sleepiness, circadian rhythms, or depression inventory parameters. Perceived Brightness of Trichromatic Light Sources AIM: To examine the effect of tuning optical radiation on brightness perception for younger (18-25 years of age) and older (50 years of age or older) observers. METHODOLOGY: Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli. The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. KEY FINDINGS: Light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by any current model of human vision or theory of brightness perception including Scotopic to Photopic or Cirtopic to Photopic ratio theory, prime color theory, correlated color temperature, photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are used, especially those with a peak wavelength shorter than 450 nm. Optimizing RGB LED Mixtures AIM: To investigate potential tradeoffs between luminous efficacy, nonvisual efficacy, and color quality of RGB LED mixtures when the peak wavelength and full with half maximum of the primaries are varied. To identify mixtures suitable for architectural lighting which provide increased circadian stimulation. METHODOLOGY: Software to calculate the properties of RGB LED mixtures matching the chromaticity of blackbody radiation was developed using Microsoft Excel and Visual Basic. Excel Solver was used to perform a series of optimization routines, identifying high-performing mixtures that were then compared to traditional lamps. KEY FINDINGS: Trichromatic mixtures suitable for architectural interiors can outperform traditional lamps when luminous efficacy, nonvisual efficacy, and color quality are considered simultaneously. However, misplacement of radiant energy can result in poor performing trichromatic systems. When radiant energy is manipulated, tradeoffs may occur between luminous efficacy, nonvisual efficacy, and color quality.
Jiang, Yu; Cui, Changyong; Ge, Hua; Guan, Suzhen; Lian, Yulong; Liu, Jiwen
2016-04-01
Occupational stress and the serotonin receptor (5-HTR) play a key role in the regulation of sleep quality. Previous studies on the relationship between work-related stress, 5-HTR2A polymorphism, and sleep complaints found that 5-HTR2A modulates the response of the hypothalamic-pituitary-adrenal axis to stress and the maintenance of circadian rhythm. However, the effect of 5-HTR2A polymorphism and occupational stress on sleep quality has not been reported. The present study investigated the effects of 5-HTR2A genotypes, occupational stress, and gene-environment interactions on the sleep quality. Using a three-stage stratified sampling method, 1181 participants were recruited. Then, according to the study exclusion criteria, 810 subjects remained eligible. Finally, because some of subjects did not agree to being involved in this study, 700 workers were included. Of 700 workers finally included in the study, 251 had poor sleep quality based on the Pittsburgh Sleep Quality Index. The 5-HTR2A genotypes were determined with the SNaPshot single nucleotide polymorphism assay. Occupational stress was assessed with the Occupational Stress Inventory-Revised questionnaire. 5-HTR2A genotype was significantly associated with sleep quality. The CT genotype of rs1923884 was detected at a higher frequency among individuals with low sleep efficiency; the AA genotype of rs2070040 was associated with long sleep duration and more daytime dysfunction; and the CC genotype of rs6313 was linked to long sleep latency and duration and poor sleep quality. A high level of occupational stress was linked to higher risk of poor sleep quality than low or moderate levels (odds ratio [OR] = 12.55, 95% confidence interval [CI]: 7.02-22.43). A crossover analysis demonstrated an occupational stress × 5-HTR2A interaction. Compared to participants with low occupational stress and a CT/TT genotype, those with high occupational stress and a CC genotype had a higher risk of poor sleep quality (OR = 7.93, 95% CI: 3.41-18.43), whereas those with low occupational stress and a CC genotype had a lower risk of poor sleep quality (OR = 1.53, 95% CI: 1.07-2.19). Occupational stress and 5-HTR2A genotypes in workers are associated both independently and in combination with increased risk of poor sleep quality. Our data provide evidence that occupational stress contributes to the risk of poor sleep quality through interaction with 5-HTR2A gene polymorphism. Copyright © 2016 Elsevier B.V. All rights reserved.
Sleep Quality Among Pharmacy Students
Clark, Andraya; Woolley, Thomas W.; Saunders, Amy
2015-01-01
Objective. To determine the quality of sleep among pharmacy students in the didactic portion of the curriculum at one school of pharmacy. Methods. The study consisted of an anonymous, voluntary survey that included the Pittsburgh Sleep Quality Index (PSQI), a self-rated instrument that measures sleep habits for a month. Results. The survey was completed by 253 students. Students in the lower grade point average (GPA) category had higher scores on 2 of 7 components of the PSQI and on the global score. Poor sleep quality, indicated by a global PSQI score of greater than 5, was reported by 140 students. The rate of poor sleeping was higher among students in the lower GPA category. Conclusion. Poor sleep quality was pervasive among surveyed pharmacy students in the didactic portion of the pharmacy school curriculum, especially among those with lower GPAs. PMID:25741025
Direct multiangle solution for poorly stratified atmospheres
Vladimir Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao
2012-01-01
The direct multiangle solution is considered, which allows improving the scanning lidar-data-inversion accuracy when the requirement of the horizontally stratified atmosphere is poorly met. The signal measured at zenith or close to zenith is used as a core source for extracting optical characteristics of the atmospheric aerosol loading. The multiangle signals are used...
Wavefront measurement using computational adaptive optics.
South, Fredrick A; Liu, Yuan-Zhi; Bower, Andrew J; Xu, Yang; Carney, P Scott; Boppart, Stephen A
2018-03-01
In many optical imaging applications, it is necessary to correct for aberrations to obtain high quality images. Optical coherence tomography (OCT) provides access to the amplitude and phase of the backscattered optical field for three-dimensional (3D) imaging samples. Computational adaptive optics (CAO) modifies the phase of the OCT data in the spatial frequency domain to correct optical aberrations without using a deformable mirror, as is commonly done in hardware-based adaptive optics (AO). This provides improvement of image quality throughout the 3D volume, enabling imaging across greater depth ranges and in highly aberrated samples. However, the CAO aberration correction has a complicated relation to the imaging pupil and is not a direct measurement of the pupil aberrations. Here we present new methods for recovering the wavefront aberrations directly from the OCT data without the use of hardware adaptive optics. This enables both computational measurement and correction of optical aberrations.
Method of fabricating optical waveguides by ion implantation doping
Appleton, B.R.; Ashley, P.R.; Buchal, C.J.
1987-03-24
A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO/sub 3/ crystals are implanted with high concentrations of Ti dopant at ion energies of about 360 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000/degree/C produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguiding properties.
Effects of tear film dynamics on quality of vision.
Koh, Shizuka; Tung, Cynthia I; Inoue, Yasushi; Jhanji, Vishal
2018-06-15
The precorneal tear film is maintained by blinking and exhibits different phases in the tear cycle. The tear film serves as the most anterior surface of the eye and plays an important role as a first refractive component of the eye. Alterations in tear film dynamics may cause both vision-related and ocular surface-related symptoms. Although the optical quality associated with the tear film dynamics previously received little attention, objective measurements of optical quality using wavefront sensors have enabled us to quantify optical aberrations induced by the tear film. This has provided an objective method for assessing reduced optical quality in dry eye; thus, visual disturbances were included in the definition of dry eye disease in the 2007 Dry Eye Workshop report. In addition, sequential measurements of wavefront aberrations have provided us with valuable insights into the dynamic optical changes associated with tear film dynamics. This review will focus on the current knowledge of the mechanisms of wavefront variations that are caused by different aspects of tear film dynamics: specifically, quality, quantity and properties of the tear film, demonstrating the respective effects of dry eye, epiphora and instillation of eye drops on the quality of vision. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Predictors of dietary quality in low-income pregnant women: a path analysis.
Fowles, Eileen R; Bryant, Miranda; Kim, SungHun; Walker, Lorraine O; Ruiz, Roberta Jeanne; Timmerman, Gayle M; Brown, Adama
2011-01-01
Despite the potential importance of nutrition to pregnancy outcomes, little is known about the factors influencing dietary quality, especially during the first trimester. The aim of this study was to examine the relationships of distress (an index of depression and stress), social support, and eating habits with dietary quality in low-income pregnant women. A cross-sectional design and path analytic methods was used in a clinic-based sample of low-income women (n = 118) in their first trimester of pregnancy. Women completed questionnaires and received training on estimating food portion sizes. Three 24-hour dietary recalls were collected over 2 weeks. Overall dietary quality was assessed using the Dietary Quality Index-Pregnancy. The final path model fit well (comparative fit index [CFI] = .97, root mean square error of approximation [RMSEA] = .05) and revealed that distress had a direct effect on poor eating habits (β = .36) and a direct (β = -.23) and indirect effect on dietary quality (β = -.30). Poor eating habits had a direct effect on dietary quality (β = -.18). Social support had no effect on dietary quality. Age had significant direct effects on education (β = .39) and nutritional knowledge (β = .18) and an indirect effect on dietary quality (total effect, β = .19). Maternal age, education, and nutritional knowledge did not have significant effects on psychosocial variables. Psychosocial distress and poor eating habits contributed to inadequate dietary quality. Assessing for depression, stress, poor eating habits, and overall dietary quality during the crucial first trimester may identify women needing more intensive dietary monitoring and intervention throughout pregnancy.
Erdal, Erik P; Mitra, Debanjali; Khangulov, Victor S; Church, Stephen; Plokhoy, Elizabeth
2017-03-01
Background Despite advances in clinical chemistry testing, poor blood sample quality continues to impact laboratory operations and the quality of results. While previous studies have identified the preanalytical causes of lower sample quality, few studies have examined the economic impact of poor sample quality on the laboratory. Specifically, the costs associated with workarounds related to fibrin and gel contaminants remain largely unexplored. Methods A quantitative survey of clinical chemistry laboratory stakeholders across 10 international regions, including countries in North America, Europe and Oceania, was conducted to examine current blood sample testing practices, sample quality issues and practices to remediate poor sample quality. Survey data were used to estimate costs incurred by laboratories to mitigate sample quality issues. Results Responses from 164 participants were included in the analysis, which was focused on three specific issues: fibrin strands, fibrin masses and gel globules. Fibrin strands were the most commonly reported issue, with an overall incidence rate of ∼3%. Further, 65% of respondents indicated that these issues contribute to analyzer probe clogging, and the majority of laboratories had visual inspection and manual remediation practices in place to address fibrin- and gel-related quality problems (55% and 70%, respectively). Probe maintenance/replacement, visual inspection and manual remediation were estimated to carry significant costs for the laboratories surveyed. Annual cost associated with lower sample quality and remediation related to fibrin and/or gel globules for an average US laboratory was estimated to be $100,247. Conclusions Measures to improve blood sample quality present an important step towards improved laboratory operations.
Lo, Catherine M H; Lee, Paul H
2012-06-18
Sleep disturbance is a complex health problem in ageing global populations decreasing quality of life among many older people. Geographic, cultural, and ethnic differences in sleep patterns have been documented within and between Western and Asian populations. The aim of this study was to explore sleep problems among Hong Kong seniors by examining the prevalence of poor sleep quality, the relationship between sleep quality and health-related quality of life, and associated factors of good sleepers in different age groups. This cross-sectional study used convenience sampling and gathered data during face-to-face interviews. Older community-dwelling individuals (n = 301) were recruited in community centres in 2010. The Pittsburgh Sleep Quality Index and Medical Outcomes Study Short Form-36 were used to measure sleep quality and health-related quality of life. The Medical Outcomes Study Short Form-36 domain scores were compared between good and bad sleepers and between long and short sleepers using Hotelling's T-Square test. SF-36 domain scores were placed into a logistic regression model that controlled for significant demographic variables (gender, educational level, perceived health). Most (77.7%) participants were poor sleepers. Participants who had global Pittsburgh Sleep Quality Index scores <5 and slept ≥5.5 h/night had better health-related quality of life. Vitality, emotional role, physical functioning, and bodily pain domain scores were associated factors of good sleepers in different age groups. This study found a strong negative association between sleep deprivation (poor quality, short duration) and health-related quality of life. Associated factors for good sleep quality in later life differ among age groups in relation to universal age-related changes, and should be addressed by social policies and health-care programmes.
ERIC Educational Resources Information Center
Tchoghandjian, Aurelie; Fernandez, Carla; Colin, Carole; El Ayachi, Ikbale; Voutsinos-Porche, Brigitte; Fina, Frederic; Scavarda, Didier; Piercecchi-Marti, Marie-Dominique; Intagliata, Dominique; Ouafik, L'Houcine; Fraslon-Vanhulle, Caroline; Figarella-Branger, Dominique
2009-01-01
Pilocytic astrocytomas are WHO grade I gliomas that occur predominantly in childhood. They share features of both astroglial and oligodendroglial lineages. These tumours affect preferentially the cerebellum (benign clinical course) and the optic pathway, especially the hypothalamo-chiasmatic region (poor prognosis). Understanding the molecular…
OPTICAL REMOTE SENSING FOR AIR QUALITY MONITORING
The paper outlines recent developments in using optical remote sensing (ORS) instruments for air quality monitoring both for gaseous pollutants and airborne particulate matter (PM). The U.S. Environmental Protection Agency (EPA) has been using open-path Fourier transform infrared...
Wind, Astrid de; Burr, Hermann; Pohrt, Anne; Hasselhorn, Hans Martin; Van der Beek, Allard Johan; Rugulies, Reiner
2017-07-01
The aims of this article are to (1) determine whether and to what extent general perceived health and quality of supervision predict voluntary early retirement pension (VERP) and (2) assess whether quality of supervision modifies the association between general perceived health and VERP. Employees aged 49-64 years who participated in the Danish Work Environment Cohort Study in 2000 were selected. Their questionnaire data about health and work were linked to register data on social transfer payments, among others VERP, from 2001 to 2012 in the Danish Register for Evaluation of Marginalization ( N=1167). Cox proportional hazards analyses were performed to identify the prospective association of general perceived health and quality of supervision on VERP. Relative excess risks due to interaction (RERIs) were calculated to assess whether quality of supervision modified the association between health and VERP. Employees with poor health at baseline had an increased risk of VERP during follow-up (hazard ratio [HR]=1.23; 95% confidence interval [CI] 1.02-1.49). Quality of supervision at baseline was not associated to VERP during follow-up (HR=1.04; 95% CI 0.90-1.21). There was no statistically significant interaction of poor health and poor quality of supervision with regard to risk of VERP (RERI=-0.33; 95% CI -1.79 to 1.14). This study did not support the notion that quality of supervision buffers the association between poor health and VERP. Future research is needed to determine whether other aspects of supervision, for example supervisors' opportunities to effectuate workplace adjustments, may modify the association of poor health and VERP.
de Wind, Astrid; Burr, Hermann; Pohrt, Anne; Hasselhorn, Hans Martin; Van der Beek, Allard Johan; Rugulies, Reiner
2017-01-01
Objectives: The aims of this article are to (1) determine whether and to what extent general perceived health and quality of supervision predict voluntary early retirement pension (VERP) and (2) assess whether quality of supervision modifies the association between general perceived health and VERP. Methods: Employees aged 49–64 years who participated in the Danish Work Environment Cohort Study in 2000 were selected. Their questionnaire data about health and work were linked to register data on social transfer payments, among others VERP, from 2001 to 2012 in the Danish Register for Evaluation of Marginalization (N=1167). Cox proportional hazards analyses were performed to identify the prospective association of general perceived health and quality of supervision on VERP. Relative excess risks due to interaction (RERIs) were calculated to assess whether quality of supervision modified the association between health and VERP. Results: Employees with poor health at baseline had an increased risk of VERP during follow-up (hazard ratio [HR]=1.23; 95% confidence interval [CI] 1.02–1.49). Quality of supervision at baseline was not associated to VERP during follow-up (HR=1.04; 95% CI 0.90–1.21). There was no statistically significant interaction of poor health and poor quality of supervision with regard to risk of VERP (RERI=−0.33; 95% CI −1.79 to 1.14). Conclusions: This study did not support the notion that quality of supervision buffers the association between poor health and VERP. Future research is needed to determine whether other aspects of supervision, for example supervisors’ opportunities to effectuate workplace adjustments, may modify the association of poor health and VERP. PMID:28381121
Sleep Quality and Nocturnal Sleep Duration in Pregnancy and Risk of Gestational Diabetes Mellitus.
Cai, Shirong; Tan, Sara; Gluckman, Peter D; Godfrey, Keith M; Saw, Seang-Mei; Teoh, Oon Hoe; Chong, Yap-Seng; Meaney, Michael J; Kramer, Michael S; Gooley, Joshua J
2017-02-01
To examine the influence of maternal sleep quality and nocturnal sleep duration on risk of gestational diabetes mellitus (GDM) in a multiethnic Asian population. A cohort of 686 women (376 Chinese, 186 Malay, and 124 Indian) with a singleton pregnancy attended a clinic visit at 26-28 weeks of gestation as part of the Growing Up in Singapore Towards healthy Outcomes mother-offspring cohort study. Self-reported sleep quality and sleep duration were assessed using the Pittsburgh Sleep Quality Index (PSQI). GDM was diagnosed based on a 75-g oral glucose tolerance test administered after an overnight fast (1999 WHO criteria). Multiple logistic regression was used to model separately the associations of poor sleep quality (PSQI score > 5) and short nocturnal sleep duration (<6 h) with GDM, adjusting for age, ethnicity, maternal education, body mass index, previous history of GDM, and anxiety (State-Trait Anxiety Inventory score). In the cohort 296 women (43.1%) had poor sleep quality and 77 women (11.2%) were categorized as short sleepers; 131 women (19.1%) were diagnosed with GDM. Poor sleep quality and short nocturnal sleep duration were independently associated with increased risk of GDM (poor sleep, adjusted odds ratio [OR] = 1.75, 95% confidence interval [CI] 1.11 to 2.76; short sleep, adjusted OR = 1.96, 95% CI 1.05 to 3.66). During pregnancy, Asian women with poor sleep quality or short nocturnal sleep duration exhibited abnormal glucose regulation. Treating sleep problems and improving sleep behavior in pregnancy could potentially reduce the risk and burden of GDM. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
Adolescent Sleepiness: Causes and Consequences.
Hansen, Shana L; Capener, Dale; Daly, Christopher
2017-09-01
Insufficient sleep duration and poor sleep quality are common among adolescents. The multidimensional causes of insufficient sleep duration and poor sleep quality include biological, health-related, environmental, and lifestyle factors. The most common direct consequence of insufficient and/or poor sleep quality is excessive daytime sleepiness, which may contribute to poor academic performance, behavioral health problems, substance use, and drowsy driving. Evaluation of sleepiness includes a detailed sleep history and sleep diary, with polysomnography only required for the assessment of specific sleep disorders. Management involves encouraging healthy sleep practices such as having consistent bed and wake times, limiting caffeine and electronics at night before bed, and eliminating napping, in addition to treating any existing sleep or medical disorders. [Pediatr Ann. 2017;46(9):e340-e344.]. Copyright 2017, SLACK Incorporated.
SLEEP QUALITY AND ITS ASSOCIATION WITH PSYCHOLOGICAL SYMPTOMS IN ADOLESCENT ATHLETES
Gomes, Gabriel Cordeiro; dos Passos, Muana Hiandra Pereira; Silva, Hítalo Andrade; de Oliveira, Valéria Mayaly Alves; Novaes, Wbinayara Alves; Pitangui, Ana Carolina Rodarti; de Araújo, Rodrigo Cappato
2017-01-01
ABSTRACT Objective: To verify the prevalence of poor sleep quality and its association with personal characteristics and symptoms of depression, anxiety and stress in amateur adolescent athletes. Methods: 309 adolescent athletes aged between 10 and 19 years were enrolled. Data collection included: a structured questionnaire, with personal information; the Pittsburgh Sleep Quality Index (PSQI); and the Depression, Anxiety and Stress Scale (DASS-21). Results are described in mean and standard deviation (numeric variables) and absolute and relative frequencies (categorical variables). For the inferential analysis, Student’s t-test and chi-square test were performed, in addition to Poisson regression. Prevalence ratios (PR) were calculated in a 95% confidence interval (95%CI). Results: The mean age of participants was 14.1±2.1, being 13.8±2.0 and 15.0±2.1, respectively, for those with good and poor sleep quality. Poor sleep quality was recorded in 28.2% (n=87), depression in 26.9% (n=83) and anxiety/stress in 40.1% (n=124). Poor sleep quality was associated with ages between 15 and 19 years (PR 1.24; 95%CI 1.14-1.37), overweight (PR 1.12; 95%CI 1.01-1.24) and psychological symptoms of depression (PR 1.23; 95%CI 1.08-1.40) and anxiety/stress (PR 1.16; 95%CI 1.04-1.28). Conclusions: The presence of overweight and psychological symptoms and the age over 15 years were risk factors for increasing the likelihood of poor sleep quality in adolescent athletes. PMID:28977294
Cheng, Tuck Seng; Loy, See Ling; Cheung, Yin Bun; Cai, Shirong; Colega, Marjorelee T.; Godfrey, Keith M.; Chong, Yap-Seng; Tan, Kok Hian; Shek, Lynette Pei-Chi; Lee, Yung Seng; Lek, Ngee; Chan, Jerry Kok Yen; Chong, Mary Foong-Fong; Yap, Fabian
2017-01-01
Plasma 25-hydroxyvitamin D (25OHD) deficiency, poor sleep quality, and night-time eating, have been independently associated with adverse pregnancy outcomes, but their inter-relationships are yet to be evaluated. We aimed to investigate the associations between maternal plasma 25OHD status and sleep quality and circadian eating patterns during pregnancy. Data on pregnant women (n = 890) from a prospective cohort (Growing Up in Singapore Towards healthy Outcomes) were analyzed. Plasma 25OHD concentration was measured, while the Pittsburgh sleep quality index (PSQI) and 24-h dietary recall were administered to women at 26–28 weeks’ gestation. Plasma 25OHD status was defined as sufficient (>75 nmol/L), insufficient (50–75 nmol/L), or deficient (<50 nmol/L). Poor sleep quality was defined by a total global PSQI score >5. Predominantly day-time (pDT) and predominantly night-time (pNT) were defined according to consumption of greater proportion of calories (i.e., >50%) from 07:00–18:59 and from 19:00–06:59, respectively. After adjustment for confounders, women with plasma 25OHD deficiency had higher odds of poor sleep quality (odds ratio (OR) 3.49; 95% confidence interval (CI) 1.84–6.63) and pNT eating (OR: 1.85; 95% CI 1.00–3.41) than those who were 25OHD sufficient. Our findings show the association of maternal plasma 25OHD deficiency with poor sleep quality and pNT eating at mid-pregnancy. PMID:28353643
Hollow core waveguide as mid-infrared laser modal beam filter
DOE Office of Scientific and Technical Information (OSTI.GOV)
Patimisco, P.; Giglio, M.; Spagnolo, V.
2015-09-21
A novel method for mid-IR laser beam mode cleaning employing hollow core waveguide as a modal filter element is reported. The influence of the input laser beam quality on fiber optical losses and output beam profile using a hollow core waveguide with 200 μm-bore size was investigated. Our results demonstrate that even when using a laser with a poor spatial profile, there will exist a minimum fiber length that allows transmission of only the Gaussian-like fundamental waveguide mode from the fiber, filtering out all the higher order modes. This essentially single mode output is preserved also when the waveguide is bentmore » to a radius of curvature of 7.5 cm, which demonstrates that laser mode filtering can be realized even if a curved light path is required.« less
Reliability of Semiconductor Laser Packaging in Space Applications
NASA Technical Reports Server (NTRS)
Gontijo, Ivair; Qiu, Yueming; Shapiro, Andrew A.
2008-01-01
A typical set up used to perform lifetime tests of packaged, fiber pigtailed semiconductor lasers is described, as well as tests performed on a set of four pump lasers. It was found that two lasers failed after 3200, and 6100 hours under device specified bias conditions at elevated temperatures. Failure analysis of the lasers indicates imperfections and carbon contamination of the laser metallization, possibly from improperly cleaned photo resist. SEM imaging of the front facet of one of the lasers, although of poor quality due to the optical fiber charging effects, shows evidence of catastrophic damage at the facet. More stringent manufacturing controls with 100% visual inspection of laser chips are needed to prevent imperfect lasers from proceeding to packaging and ending up in space applications, where failure can result in the loss of a space flight mission.
Chen, Binyao; Gao, Enting; Chen, Haoyu; Yang, Jianling; Shi, Fei; Zheng, Ce; Zhu, Weifang; Xiang, Dehui; Chen, Xinjian; Zhang, Mingzhi
2016-01-01
To investigate the profile and determinants of retinal optical intensity in normal subjects using 3D spectral domain optical coherence tomography (SD OCT). A total of 231 eyes from 231 healthy subjects ranging in age from 18 to 80 years were included and underwent a 3D OCT scan. Forty-four eyes were randomly chosen to be scanned by two operators for reproducibility analysis. Distribution of optical intensity of each layer and regions specified by the Early Treatment of Diabetic Retinopathy Study (ETDRS) were investigated by analyzing the OCT raw data with our automatic graph-based algorithm. Univariate and multivariate analyses were performed between retinal optical intensity and sex, age, height, weight, spherical equivalent (SE), axial length, image quality, disc area and rim/disc area ratio (R/D area ratio). For optical intensity measurements, the intraclass correlation coefficient of each layer ranged from 0.815 to 0.941, indicating good reproducibility. Optical intensity was lowest in the central area of retinal nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer and photoreceptor layer, except for the retinal pigment epithelium (RPE). Optical intensity was positively correlated with image quality in all retinal layers (0.553<β<0.851, p<0.01), and negatively correlated with age in most retinal layers (-0.362<β<-0.179, p<0.01), except for the RPE (β = 0.456, p<0.01), outer nuclear layer and photoreceptor layer (p>0.05). There was no relationship between retinal optical intensity and sex, height, weight, SE, axial length, disc area and R/D area ratio. There was a specific pattern of distribution of retinal optical intensity in different regions. The optical intensity was affected by image quality and age. Image quality can be used as a reference for normalization. The effect of age needs to be taken into consideration when using OCT for diagnosis.
A community-based cross-sectional study of sleep quality in middle-aged and older adults.
Zhang, Hui-Shan; Li, Yuan; Mo, Hai-Yun; Qiu, De-Xing; Zhao, Jing; Luo, Jia-Li; Lin, Wei-Quan; Wang, Jia-Ji; Wang, Pei-Xi
2017-04-01
Sleep quality has been widely studied among western countries. However, there is limited population-based evidence on insomnia in Chinese adult populations, especially in middle-aged and older adults. The aims of present study are to (1) examine the prevalence of poor sleep among Chinese middle-age and older adults, (2) compare the Pittsburgh Sleep Quality Index (PSQI) seven domain scores across different physical health statuses, (3) explore factors associated with insomnia. A cross-sectional survey was conducted using a multi-instrument questionnaire. In total, 1563 residents aged 45 or older in the community were interviewed. The Chinese version of the PSQI was used to assess sleep quality while poor sleep was defined as a total PSQI score >5. Socio-demographic, lifestyle and physical health data were also collected. The prevalence of poor sleep among adults aged over 45 years was 20.67 %. Clusters logistic regression analysis identified that migrant workers, single marital status, lower education level, no physical exercise, illness within 2 weeks, and a higher total number of chronic diseases contribute to increased risk of poor sleep (P < 0.05). Among three clusters, physical health has the biggest independent contribution on sleep quality. Our results indicated that poor sleep was common in middle-aged and older adults. It was associated with identity of migrant worker, education level, exercise, illness within 2 weeks and number of chronic disease. Being ill within 2 weeks and having more chronic diseases were the major physical health-related factors contributing to poor sleep in the middle-aged and older people. Physical health may be a major determinant in sleep quality.
Asthma-specific health-related quality of life of people in Great Britain: A national survey.
Upton, Jane; Lewis, Carine; Humphreys, Emily; Price, David; Walker, Samantha
2016-11-01
Although the ultimate goal of asthma treatment is to improve asthma-specific Health-Related Quality-Of-Life (HRQOL), in the UK population this is insufficiently studied. National asthma-specific HRQOL data is needed to inform strategies to address this condition. To benchmark asthma-specific HRQOL in a national survey of adults with asthma, and explore differences in this measure within subsections of the population. We analysed answers to the Marks Asthma Quality-of-Life Questionnaire (AQLQ-M) from a representative sample of 658 adults with asthma. Respondents answered asthma-specific questions to assess control, previous hospital admissions, asthma attacks and an indicator of severity. Higher scores indicate poorer HRQOL (maximum = 60). The highest quintile formed a subgroup 'Poor HRQOL'. Data were weighted to correct for any biases caused by differential non-response. Chi-square analyses were used to determine differences between good and poor quality of life and regression analyses performed to determine what factors are associated with poor HRQOL. The response rate was 49%. AQLQ-M median (IQR) scores were 5 (2-13) for the total sample (poor HRQOL = 21, good HRQOL = 3). Significant differences between good and poor HRQOL were observed in smoking status, SES, employment status and co-morbidities, but no differences were found between age groups. Those with poorly controlled asthma were significantly more likely to have poor HRQOL, ≥1 breathing related hospital admission or ≥1 asthma attack. This article provides benchmarking data on asthma-specific HRQOL. Improved strategies are needed to target interventions towards people experiencing poor HRQOL.
A test of vegetation-related indicators of wetland quality in the prairie pothole region
Kantrud, H.A.; Newton, W.E.
1996-01-01
This study was part of an effort by the U.S. Environmental Protection Agency to quantitatively assess the environmental quality or 'health' of wetland resources on regional and national scales. During a two-year pilot study, we tested selected indicators of wetland quality in the U.S. portion of the prairie pothole region (PPR). We assumed that the amount of cropland versus non-cropland (mostly grassland) in the plots containing these basins was a proxy for their quality. We then tested indicators by their ability to discriminate between wetlands at the extremes of that proxy. Amounts of standing dead vegetation were greater in zones of greater water permanence. Depth of litter was greater in zones of greater water permanence and in zones of basins in poor-quality watersheds. Amounts of unvegetated bottom were greater in basins in poor-quality watersheds; lesser amounts occurred in all wetlands during a wetter year. Greater amounts of open water occurred during a wetter year and in zones of greater water permanence. When unadjusted for areas (ha) of communities, plant taxon richness was higher in wet-meadow and shallow-marsh zones in good-quality watersheds than in similar zones in poor-quality watersheds. Wet-meadow zones in good-quality watersheds had greater numbers of native perennials than those in poor-quality watersheds. This relation held when we eliminated all communities in good-quality watersheds larger than the largest communities in poor-quality watersheds from the data set. We conclude that although amounts of unvegetated bottom and plant taxon richness in wet-meadow zones were useful indicators of wetland quality during our study, the search for additional such indicators should continue. The value of these indicators may change with the notoriously unstable hydrological conditions in the PPR. Most valuable would be indicators that could be photographed or otherwise remotely sensed and would remain relatively stable under various hydrological conditions. An ideal set of indicators could detect the absence of stressors, as well as the presence of structures or functions, of known value to major groups of organisms.
Kilohertz Pulse Repetition Frequency Slab Ti:sapphire Lasers with High Average Power (10 W)
NASA Astrophysics Data System (ADS)
Wadsworth, William J.; Coutts, David W.; Webb, Colin E.
1999-11-01
High-average-power broadband 780-nm slab Ti:sapphire lasers, pumped by a kilohertz pulse repetition frequency copper vapor laser (CVL), were demonstrated. These lasers are designed for damage-free power scaling when pumped by CVL s configured for maximum output power (of order 100 W) but with poor beam quality ( M 2 300 ). A simple Brewster-angled slab laser side pumped by a CVL produced 10-W average power (1.25-mJ pulses at 8 kHz) with 4.2-ns FWHM pulse duration at an absolute efficiency of 15% (68-W pump power). Thermal lensing in the Brewster slab laser resulted in multitransverse mode output, and pump absorption was limited to 72% by the maximum doping level for commercially available Ti:sapphire (0.25%). A slab laser with a multiply folded zigzag path was therefore designed and implemented that produced high-beam-quality (TEM 00 -mode) output when operated with cryogenic cooling and provided a longer absorption path for the pump. Excessive scattering of the Ti:sapphire beam at the crystal surfaces limited the efficiency of operation for the zigzag laser, but fluorescence diagnostic techniques, gain measurement, and modeling suggest that efficient power extraction ( 15 W TEM 00 , 23% efficiency) from this laser would be possible for crystals with an optical quality surface polish.
ERIC Educational Resources Information Center
Manning, Matthew; Garvis, Susanne; Fleming, Christopher; Wong, Gabriel T. W.
2017-01-01
Poor quality early childhood education and care (ECEC) can be detrimental to the development of children as it could lead to poor social, emotional, educational, health, economic, and behavioural outcomes. The lack of consensus as to the strength of the relationship between teacher qualification and the quality of the early childhood learning…
Update to the Propagation and Establishment of Aquatic Plants Handbook
2005-03-01
decades or even longer. In the interim these reservoirs provide relatively poor aquatic habitat and water quality. Unvegetated aquatic ecosystems are also...establishment or reestab- lishment of aquatic plant communities. Many reservoirs without aquatic plants suffer from poor water quality (high nutrients...serve as a food source for waterfowl and other aquatic wildlife, improve water clarity and quality (James and Barko 1990), reduce rates of
A patient survey of sleep quality in the Intensive Care Unit.
Little, A; Ethier, C; Ayas, N; Thanachayanont, T; Jiang, D; Mehta, S
2012-04-01
Patients in the Intensive Care Unit (ICU) experience qualitative and quantitative sleep disruption leading to sleep deprivation and adverse sequelae. Patient-related factors, environmental factors, and health-support techniques contribute to sleep disruption. This quality improvement study examines potential factors contributing to poor sleep in the ICU. Medical and surgical patients who spent at least one night in one of two academic Canadian ICUs were asked to complete a questionnaire that explored quality and quantity of sleep, factors contributing to poor sleep, and suggested modifications to improve sleep in the ICU. Patient demographics as well as admission data were recorded. Study population was 116 patients (63 M:53 F). Mean age was 55.5 ± 18.1 years and APACHE II score 16.0 ± 7.9. 45.7% were mechanically ventilated, and 68.9% received intravenous sedatives and/or analgesics. Sleep quality in the ICU was rated as poor/very poor by 59% of patients compared to 24% at home; the 5 most frequently cited reasons for this were noise, pain, light, loud talking, and intravenous catheters. Patients suggested the following nocturnal modifications: closing doors/blinds, no unnecessary interruptions, sleeping pills, and dimmed lights. No significant correlations were found between perceived sleep quality and illness severity or mechanical ventilation. Patients who received intravenous sedatives reported better sleep quality (P<0.01). Patients commonly report poor sleep in the ICU related to environmental factors that are potentially modifiable.
Marital quality and diabetes: results from the Health and Retirement Study.
Whisman, Mark A; Li, Angela; Sbarra, David A; Raison, Charles L
2014-08-01
Poor marital quality is associated with many different indicators of poor health, including immunologic and metabolic responses that have relevance for distal disease outcomes such as diabetes. We conducted this study to evaluate whether poor marital quality was associated with the prevalence of diabetes in a population-based sample of Americans over the age of 50. Participants were married adults from the 2006 (N = 3,898) and 2008 (N = 3,452) waves of the Health and Retirement Study. Participants completed an interview and a self-report questionnaire, and current use of diabetes medication and glycosylated hemoglobin obtained from blood spot samples were used to index diabetes status. Marital quality was assessed with items regarding perceived frequency of positive and negative exchanges with partner. Decreasing frequency of positive exchanges and increasing frequency of negative exchanges with one's spouse were associated with higher prevalence of diabetes among men, but not women at both waves; gender significantly moderated the associations between partner exchanges and diabetes status for the 2006 data. The association between frequency of partner exchanges and diabetes status generally remained significant in men after accounting for demographic characteristics and other risk factors (obesity, hypertension, low physical activity). Poor marital quality as operationalized by rates of positive and negative partner exchanges was associated with increased prevalence of diabetes in men. These results are consistent with prior work on marriage and health, and suggest that poor marital quality may be a unique risk factor for diabetes.
Effect of early trauma on the sleep quality of euthymic bipolar patients.
Aubert, E; Jaussent, I; Olié, E; Ducasse, D; Azorin, J M; Bellivier, F; Belzeaux, R; Bougerol, T; Etain, B; Gard, S; Henry, C; Kahn, J P; Leboyer, M; Loftus, J; Passerieux, C; Lopez-Castroman, J; Courtet, Ph
2016-12-01
Poor quality of sleep is frequent in euthymic bipolar patients and conveys worse clinical outcomes. We investigated the features of euthymic bipolar patients associated with poor sleep quality, with a focus on the effect of childhood trauma. 493 euthymic patients with DSM-IV-defined bipolar disorders were recruited in FondaMental Advanced Centers of Expertize for Bipolar Disorders (FACE-BD) between 2009 and 2014. Clinical variables were recorded. Subjective sleep quality and history of childhood trauma were respectively measured by the Pittsburgh Sleep Quality Index (PSQI) and the Childhood Trauma Questionnaire (CTQ). Poor sleepers were older, less professionally active, had significantly higher anxiety levels, took more anxiolytic drugs and did endorse more suicide attempts and suicidal ideas than good sleepers after adjusting for anxiety levels and age. Emotional abuse was associated with poor sleep quality after adjustment for BMI, age, professional activity, and bipolar disorders (BD) type (OR=1.83; 95% CI [1.30; 3.10]; p=0.02). However, this association was lost after adjustment for anxiety levels, anxiolytic treatment and suicide ideation/attempts. The main limitation was the type of sleep assessment, which only measured the subjective part of sleep complaints. A history of emotional abuse might underlie sleep problems in many bipolar patients but anxiety seems to act as a confounding factor in this relationship. New studies are needed to elucidate the role of childhood maltreatment on poor sleep among bipolar patients. Copyright © 2016 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yu, S; Hristov, D; Phillips, T
Purpose: Transperineal ultrasound imaging is attractive option for imageguided radiation therapy as there is no need to implant fiducials, no extra imaging dose, and real time continuous imaging is possible during treatment. The aim of this study is to verify the tracking accuracy of a commercial ultrasound system under treatment conditions with a male pelvic phantom. Methods: A CT and ultrasound scan were acquired for the male pelvic phantom. The phantom was then placed in a treatment mimicking position on a motion platform. The axial and lateral tracking accuracy of the ultrasound system were verified using an independent optical trackingmore » system. The tracking accuracy was evaluated by tracking the phantom position detected by the ultrasound system, and comparing it to the optical tracking system under the conditions of beam on (15 MV), beam off, poor image quality with an acoustic shadow introduced, and different phantom motion cycles (10 and 20 second periods). Additionally, the time lag between the ultrasound-detected and actual phantom motion was investigated. Results: Displacement amplitudes reported by the ultrasound system and optical system were within 0.5 mm of each other for both directions and all conditions. The ultrasound tracking performance in axial direction was better than in lateral direction. Radiation did not interfere with ultrasound tracking while image quality affected tracking accuracy. The tracking accuracy was better for periodic motion with 20 second period. The time delay between the ultrasound tracking system and the phantom motion was clinically acceptable. Conclusion: Intrafractional prostate motion is a potential source of treatment error especially in the context of emerging SBRT regimens. It is feasible to use transperineal ultrasound daily to monitor prostate motion during treatment. Our results verify the tracking accuracy of a commercial ultrasound system to be better than 1 mm under typical external beam treatment conditions.« less
All-Optical Wavelength-Path Service With Quality Assurance by Multilayer Integration System
NASA Astrophysics Data System (ADS)
Yagi, Mikio; Tanaka, Shinya; Satomi, Shuichi; Ryu, Shiro; Asano, Shoichiro
2006-09-01
In the future all-optical network controlled by generalized multiprotocol label switching (GMPLS), the wavelength path between end nodes will change dynamically. This inevitably means that the fiber parameters along the wavelength path will also vary. This variation in fiber parameters influences the signal quality of high-speed-transmission system (bit rates over 40 Gb/s). Therefore, at a path setup, the fiber-parameter effect should be adequately compensated. Moreover, the path setup must be completed fast enough to meet the network-application demands. To realize the rapid setup of adequate paths, a multilayer integration system for all-optical wavelength-path quality assurance is proposed. This multilayer integration system is evaluated in a field trial. In the trial, the GMPLS control plane, measurement plane, and data plane coordinated to maintain the quality of a 40-Gb/s wavelength path that would otherwise be degraded by the influence of chromatic dispersion. It is also demonstrated that the multilayer integration system can assure the signal quality in the face of not only chromatic dispersion but also degradation in the optical signal-to-noise ratio by the use of a 2R regeneration system. Our experiments confirm that the proposed multilayer integration system is an essential part of future all-optical networks.
Lee, Joo Eun; Jang, Sung In; Ju, Yeong Jun; Kim, Woorim; Lee, Hyo Jung; Park, Eun Cheol
2017-07-01
Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011-2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or short sleep duration in the previous year. A generalized estimating equation was used to analyze the data. High mobile phone addiction (mobile phone addiction score > 20) increased the risk of poor sleep quality but not short sleep duration. We suggest that consistent monitoring and effective intervention programs are required to prevent mobile phone addiction and improve adolescents' sleep quality. © 2017 The Korean Academy of Medical Sciences.
2017-01-01
Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011–2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or short sleep duration in the previous year. A generalized estimating equation was used to analyze the data. High mobile phone addiction (mobile phone addiction score > 20) increased the risk of poor sleep quality but not short sleep duration. We suggest that consistent monitoring and effective intervention programs are required to prevent mobile phone addiction and improve adolescents' sleep quality. PMID:28581275
Jansen van Rensburg, Jacoba J M; Maree, Johanna E; van Belkum, Corrien
2013-02-01
Quality of life is an ill-defined term, as it means different things to different people. Quality of life has been well researched, especially with respect to people with cancer, but not necessarily from the perspective of the patient, and also, not in Third World, resource-poor countries. The objective of this study was to explore quality of life from the perspective of palliative care patients managed at a palliative care clinic serving a resource-poor community in Tshwane, South Africa. An exploratory, qualitative phenomenological study was conducted. The target population for this study was all patients managed at a palliative care clinic serving a resource-poor community in Tshwane. Self-report data were gathered by means of in-depth interviews. The data were analyzed using a template analysis style as well as content analysis using open coding. Data analysis was done concurrently with data gathering. Data saturation was reached after 10 interviews (n = 10). Three themes arose from the data: factors that had a positive influence on quality of life, factors that had a negative influence on quality of life, and experience of quality of life. Work played the most important role in quality of life whereas only one participant linked symptom control with quality of life. Experiencing symptoms, rejection, and stigmatization had a negative influence on quality of life. Friends and religion played a significant role and added to quality of life. Life was a daily struggle for survival. Poverty was so overwhelming that quality of life was primarily measured in terms of the ability to buy food and other basic commodities.
Sharkey, Joseph R; Johnson, Cassandra M; Dean, Wesley R
2011-07-22
The authors examined the associations of household food insecurity and other characteristics with fair-to-poor general health, poor physical health, and frequent mental distress among 1,367 rural and urban women in Texas. The 2006 Brazos Valley Community Health Assessment provided data on demographic characteristics, economic risk factors, health-related quality of life, household food insecurity, and geographic residence. Multivariable logistic regression models were estimated for the three health-related quality of life measures: fair-to-poor health, poor physical health, and frequent mental distress, adjusting for confounding variables. Having less than 12 years of education, not being employed full-time, and being household food insecure were independently significantly associated with increased odds for all health-related quality of life outcomes. Rural residence and being nonwhite were associated with fair-to-poor general health, but not physical or mental health. Results from the separate urban and rural models indicated that household food insecurity was associated with fair-to-poor general health among rural women, not among urban women. Poverty and being nonwhite were also associated with increased odds of reporting fair-to-poor general health, but were significant only among urban women. These results emphasize the need for health promotion and policy efforts to consider household food access and availability as part of promoting healthful food choices and good physical and mental health among women, especially rural women.
Menopause is associated with self-reported poor sleep quality in women without vasomotor symptoms.
Hung, Hao-Chang; Lu, Feng-Hwa; Ou, Horng-Yih; Wu, Jin-Shang; Yang, Yi-Ching; Chang, Chih-Jen
2014-08-01
The aim of this study was to investigate the relationship between menopause and self-reported sleep quality in Chinese women without vasomotor symptoms. Cross-sectional data were collected from a decoded database of the National Cheng Kung University Hospital. Menopause was defined as absence of menses for at least 12 months or a history of hysterectomy and oophorectomy. Self-reported sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). A higher global PSQI score indicates poorer self-reported sleep quality, and a global PSQI score greater than 5 differentiates poor sleepers from good sleepers. Of the 1,088 women recruited, 353 (32.4%) were in postmenopause status. Postmenopausal women had higher mean (SD) global PSQI scores (8.0 [3.3] vs. 6.1 [2.2], P < 0.001) and a greater prevalence of poor sleepers (73.1% vs. 60.8%, P < 0.001) compared with premenopausal women. Multivariate linear regression analysis showed that menopause (β = 1.532; 95% CI, 1.135 to 1.949; P < 0.001) and snoring (β = 0.764; 95% CI, 0.299 to 1.228; P = 0.001) were positively associated with global PSQI scores, whereas long sleep duration (β = -0.791; 95% CI, -1.113 to -0.468; P < 0.001) was negatively associated with global PSQI scores. Multivariate logistic regression analyses showed that menopause (odds ratio, 1.453; 95% CI, 1.030 to 2.051; P < 0.05), long sleep duration (odds ratio, 0.545; 95% CI, 0.418 to 0.710; P < 0.001), and snoring (odds ratio, 2.022; 95% CI, 1.312 to 3.116; P = 0.001) were independent predictors of poor sleepers. Postmenopausal women without vasomotor symptoms have significantly higher global PSQI scores and a higher risk of being poor sleepers than premenopausal women. In addition, menopause and snoring are associated with an increased risk of poor self-reported sleep quality independently of cardiometabolic factors and lifestyle, whereas long sleep duration is associated with a decreased risk of poor self-reported sleep quality.
Research in the Optical Sciences
1994-02-01
Gain Asymmetry and the Generation of New Frequencies2 "’ When a stable coherent beam is injected into a VCSEL that is lasing just above threshold, we... optical microscope was developed and tested. High quality single-crystal layers of beryllium were grown on germanium by molecular beam epitaxy (MBE... OPTICAL ELEWENTS FOR X-UV WAVELENGTHS FALCO AND SLAUGHTEM indicate an increase in crystalline quality as T is increased. However, samples deposited at
Sleep quality at 3 months postpartum considering maternal age: A comparative study.
Wen, Shih-Yi; Ko, Yi-Li; Jou, Hei-Jen; Chien, Li-Yin
2018-03-01
Poor sleep quality is related to old age among the general population, but few studies have focused on postpartum women of advanced maternal age. The present study aimed to describe and compare sleep quality between women younger or older than 35 years of age at 3 months postpartum, and to examine the related factors. A cross-sectional survey was conducted with 160 postpartum women who had given birth at a teaching hospital in Taiwan. The participants were assigned to two groups according to age (≥35 years, n=80; and 20-34 years, n=80). Sleep quality was measured using the Pittsburgh Sleep Quality Index with a cut-off score of 5. The prevalence of poor sleep quality at 3 months postpartum was higher in older mothers (61.6%) than in younger mothers (38.4%, p<0.01). Multiple logistic regression revealed that poor sleep quality was positively correlated with the severity of postpartum physical symptoms, lack of exercise, and room-sharing with infants. After adjustment for those variables, older mothers were three times more likely to have poor sleep quality than younger mothers (odds ratio=3.08; 95% confidence interval 1.52-6.23). Health care providers should pay attention to sleep problems among postpartum women, especially mothers of advanced maternal age. In particular, health care providers should evaluate sleep quality among postpartum women, instruct them not to share the bed with their infants at night, perform exercise, and manage their postpartum physical symptoms to improve the sleep quality. Copyright © 2018 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.
High quality optically polished aluminum mirror and process for producing
NASA Technical Reports Server (NTRS)
Lyons, III, James J. (Inventor); Zaniewski, John J. (Inventor)
2005-01-01
A new technical advancement in the field of precision aluminum optics permits high quality optical polishing of aluminum monolith, which, in the field of optics, offers numerous benefits because of its machinability, lightweight, and low cost. This invention combines diamond turning and conventional polishing along with india ink, a newly adopted material, for the polishing to accomplish a significant improvement in surface precision of aluminum monolith for optical purposes. This invention guarantees the precise optical polishing of typical bare aluminum monolith to surface roughness of less than about 30 angstroms rms and preferably about 5 angstroms rms while maintaining a surface figure accuracy in terms of surface figure error of not more than one-fifteenth of wave peak-to-valley.
High quality optically polished aluminum mirror and process for producing
NASA Technical Reports Server (NTRS)
Lyons, III, James J. (Inventor); Zaniewski, John J. (Inventor)
2002-01-01
A new technical advancement in the field of precision aluminum optics permits high quality optical polishing of aluminum monolith, which, in the field of optics, offers numerous benefits because of its machinability, lightweight, and low cost. This invention combines diamond turning and conventional polishing along with india ink, a newly adopted material, for the polishing to accomplish a significant improvement in surface precision of aluminum monolith for optical purposes. This invention guarantees the precise optical polishing of typical bare aluminum monolith to surface roughness of less than about 30 angstroms rms and preferably about 5 angstroms rms while maintaining a surface figure accuracy in terms of surface figure error of not more than one-fifteenth of wave peak-to-valley.
A Comparison of Spectacles Purchased Online and in UK Optometry Practice.
Alderson, Alison J; Green, Alison; Whitaker, David; Scally, Andrew J; Elliott, David B
2016-10-01
To compare spectacles bought online with spectacles from optometry practices. Thirty-three participants consisting of single vision spectacle wearers with either a low (N = 12, mean age 34 ± 14 years) or high prescription (N = 11, mean age 28 ± 9 years) and 10 presbyopic participants (mean age 59 ± 4 years) wearing progressive addition lenses (PALs) purchased 154 pairs of spectacles online and 154 from UK optometry practices. The spectacles were compared via participant-reported preference, acceptability, and safety; the assessment of lens, frame, and fit quality; and the accuracy of the lens prescriptions to international standard ISO 21987:2009. Participants preferred the practice spectacles (median ranking 4th, IQR 1-6) more than online (6th, IQR 4-8; Mann-Whitney U = 7345, p < 0.001) and practice PALs (median ranking 2nd, IQR 1-4) were particularly preferred (online 6.5th, IQR 4-9, Mann-Whitney U = 455, p < 0.001). Of those deemed unacceptable and unsafe, significantly more were bought online (unacceptable: online 43/154 vs. practice 15/154, Fisher's exact p = 0.0001; unsafe: online 14/154 vs. practice 5/154, Fisher's exact p = 0.03). Participants preferred spectacles from optometry practice rather than those bought online, despite lens quality and prescription accuracy being similar. A greater number of online spectacles were deemed unsafe or unacceptable because of poor spectacle frame fit, poor cosmetic appearance, and inaccurate optical centration. This seems particularly pertinent to PAL lenses, which are known to increase falls risk. Recommendations are made to improve both forms of spectacle provision.
Fernandez, Facundo M.; Hostetler, Dana; Powell, Kristen; Kaur, Harparkash; Green, Michael D.; Mildenhall, Dallas C.; Newton, Paul N.
2012-01-01
Throughout history, poor quality medicines have been a persistent problem, with periodical crises in the supply of antimicrobials, such as fake cinchona bark in the 1600s and fake quinine in the 1800s. Regrettably, this problem seems to have grown in the last decade, especially afflicting unsuspecting patients and those seeking medicines via on-line pharmacies. Here we discuss some of the challenges related to the fight against poor quality drugs, and counterfeits in particular, with an emphasis on the analytical tools available, their relative performance, and the necessary workflows needed for distinguishing between genuine, substandard, degraded and counterfeit medicines. PMID:21107455
Sleep habits, mental health, and the metabolic syndrome in law enforcement officers.
Yoo, Hyelim; Franke, Warren D
2013-01-01
To assess the association of sleep characteristics and mental health with the metabolic syndrome (MetS) in law enforcement officers (LEOs). Sleep duration (≤6, >6-<8, ≥8 hours/night), sleep quality ("good," "poor"), mental health (stress, burnout, depression), and MetS components were compared in 106 LEOs. The prevalence of MetS was 33%. After covariate adjustment including the mental health measures, long sleep duration was associated with MetS (odds ratio = 4.89, 95% confidence interval = 1.32 to 18.13), whereas sleep quality was not. LEOs with short sleep duration or poor sleep quality reported more stress, burnout, and depression symptoms. In LEOs, sleep duration is more strongly associated with the occurrence of MetS than sleep quality, independent of mental health. Nevertheless, short sleep duration and poor sleep quality may affect mental health in LEOs.
Sanchez, Sixto E.; Islam, Suhayla; Zhong, Qiu-Yue; Gelaye, Bizu; Williams, Michelle A.
2016-01-01
Objectives To examine the associations of Intimate partner violence (IPV) with stress-related sleep disturbance (measured using the Ford Insomnia Response to Stress Test [FIRST]) and poor sleep quality (measured using the Pittsburgh Sleep Quality Index [PSQI]) during early pregnancy. Methods This cross-sectional study included 634 pregnant Peruvian women. In-person interviews were conducted in early pregnancy to collect information regarding IPV history, and sleep traits. Adjusted odds ratios (aOR) and 95% confidence intervals (95%CIs) were calculated using logistic regression procedures. Results Lifetime IPV was associated with a 1.54-fold increased odds of stress-related sleep disturbance (95% CI: 1.08–2.17) and a 1.93-fold increased odds of poor sleep quality (95% CI: 1.33–2.81). Compared with women experiencing no IPV during lifetime, the aOR (95% CI) for stress-related sleep disturbance associated with each type of IPV were: physical abuse only 1.24 (95% CI: 0.84–1.83), sexual abuse only 3.44 (95%CI: 1.07–11.05), and physical and sexual abuse 2.51 (95% CI: 1.27–4.96). The corresponding aORs (95% CI) for poor sleep quality were: 1.72 (95% CI: 1.13–2.61), 2.82 (95% CI: 0.99–8.03), and 2.50 (95% CI: 1.30–4.81), respectively. Women reporting any IPV in the year prior to pregnancy had increased odds of stress-related sleep disturbance (aOR = 2.07; 95% CI: 1.17–3.67) and poor sleep quality (aOR = 2.27; 95% CI: 1.30–3.97) during pregnancy. Conclusion Lifetime and prevalent IPV exposures are associated with stress-related sleep disturbance and poor sleep quality during pregnancy. Our findings suggest that sleep disturbances may be important mechanisms that underlie the lasting adverse effects of IPV on maternal and perinatal health. PMID:27023005
Method of fabricating optical waveguides by ion implantation doping
Appleton, Bill R.; Ashley, Paul R.; Buchal, Christopher J.
1989-01-01
A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO.sub.3 crystals are implanted with high concentrations of Ti dopant at ion energies of about 350 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000.degree. C. produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality single crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguides properties.
Optical design of multi-multiple expander structure of laser gas analysis and measurement device
NASA Astrophysics Data System (ADS)
Fu, Xiang; Wei, Biao
2018-03-01
The installation and debugging of optical circuit structure in the application of carbon monoxide distributed laser gas analysis and measurement, there are difficult key technical problems. Based on the three-component expansion theory, multi-multiple expander structure with expansion ratio of 4, 5, 6 and 7 is adopted in the absorption chamber to enhance the adaptability of the installation environment of the gas analysis and measurement device. According to the basic theory of aberration, the optimal design of multi-multiple beam expander structure is carried out. By using image quality evaluation method, the difference of image quality under different magnifications is analyzed. The results show that the optical quality of the optical system with the expanded beam structure is the best when the expansion ratio is 5-7.
Chiesura, Gabriele; Luyckx, Geert; Voet, Eli; Lammens, Nicolas; Van Paepegem, Wim; Degrieck, Joris; Dierick, Manuel; Van Hoorebeke, Luc; Vanderniepen, Pieter; Sulejmani, Sanne; Sonnenfeld, Camille; Geernaert, Thomas; Berghmans, Francis
2015-01-01
Quality of embedment of optical fibre sensors in carbon fibre-reinforced polymers plays an important role in the resultant properties of the composite, as well as for the correct monitoring of the structure. Therefore, availability of a tool able to check the optical fibre sensor-composite interaction becomes essential. High-resolution 3D X-ray Micro-Computed Tomography, or Micro-CT, is a relatively new non-destructive inspection technique which enables investigations of the internal structure of a sample without actually compromising its integrity. In this work the feasibility of inspecting the position, the orientation and, more generally, the quality of the embedment of an optical fibre sensor in a carbon fibre reinforced laminate at unit cell level have been proven. PMID:25961383
Comparison of ground based indices (API and AQI) with satellite based aerosol products.
Zheng, Sheng; Cao, Chun-Xiang; Singh, Ramesh P
2014-08-01
Air quality in mega cities is one of the major concerns due to serious health issues and its indirect impact to the climate. Among mega cities, Beijing city is considered as one of the densely populated cities with extremely poor air quality. The meteorological parameters (wind, surface temperature, air temperature and relative humidity) control the dynamics and dispersion of air pollution. China National Environmental Monitoring Centre (CNEMC) started air pollution index (API) as of 2000 to evaluate air quality, but over the years, it was felt that the air quality is not well represented by API. Recently, the Ministry of Environmental Protection (MEP) of the People's Republic of China (PRC) started using a new index "air quality index (AQI)" from January 2013. We have compared API and AQI with three different MODIS (MODIS - Moderate Resolution Imaging SpectroRadiometer, onboard the Terra/Aqua satellites) AOD (aerosol optical depth) products for ten months, January-October, 2013. The correlation between AQI and Aqua Deep Blue AOD was found to be reasonably good as compared with API, mainly due to inclusion of PM2.5 in the calculation of AQI. In addition, for every month, the correlation coefficient between AQI and Aqua Deep Blue AOD was found to be relatively higher in the month of February to May. According to the monthly average distribution of precipitation, temperature, and PM10, the air quality in the months of June-September was better as compared to those in the months of February-May. AQI and Aqua Deep Blue AOD show highly polluted days associated with dust event, representing true air quality of Beijing. Copyright © 2013 Elsevier B.V. All rights reserved.
Tracing the influence of land-use change on water quality and coral reefs using a Bayesian model.
Brown, Christopher J; Jupiter, Stacy D; Albert, Simon; Klein, Carissa J; Mangubhai, Sangeeta; Maina, Joseph M; Mumby, Peter; Olley, Jon; Stewart-Koster, Ben; Tulloch, Vivitskaia; Wenger, Amelia
2017-07-06
Coastal ecosystems can be degraded by poor water quality. Tracing the causes of poor water quality back to land-use change is necessary to target catchment management for coastal zone management. However, existing models for tracing the sources of pollution require extensive data-sets which are not available for many of the world's coral reef regions that may have severe water quality issues. Here we develop a hierarchical Bayesian model that uses freely available satellite data to infer the connection between land-uses in catchments and water clarity in coastal oceans. We apply the model to estimate the influence of land-use change on water clarity in Fiji. We tested the model's predictions against underwater surveys, finding that predictions of poor water quality are consistent with observations of high siltation and low coverage of sediment-sensitive coral genera. The model thus provides a means to link land-use change to declines in coastal water quality.
Fortune, Brad; Reynaud, Juan; Cull, Grant; Burgoyne, Claude F.; Wang, Lin
2014-01-01
Purpose To evaluate the effect of age on optic nerve axon counts, spectral-domain optical coherence tomography (SDOCT) scan quality, and peripapillary retinal nerve fiber layer thickness (RNFLT) measurements in healthy monkey eyes. Methods In total, 83 healthy rhesus monkeys were included in this study (age range: 1.2–26.7 years). Peripapillary RNFLT was measured by SDOCT. An automated algorithm was used to count 100% of the axons and measure their cross-sectional area in postmortem optic nerve tissue samples (N = 46). Simulation experiments were done to determine the effects of optical changes on measurements of RNFLT. An objective, fully-automated method was used to measure the diameter of the major blood vessel profiles within each SDOCT B-scan. Results Peripapillary RNFLT was negatively correlated with age in cross-sectional analysis (P < 0.01). The best-fitting linear model was RNFLT(μm) = −0.40 × age(years) + 104.5 μm (R2 = 0.1, P < 0.01). Age had very little influence on optic nerve axon count; the result of the best-fit linear model was axon count = −1364 × Age(years) + 1,210,284 (R2 < 0.01, P = 0.74). Older eyes lost the smallest diameter axons and/or axons had an increased diameter in the optic nerve of older animals. There was an inverse correlation between age and SDOCT scan quality (R = −0.65, P < 0.0001). Simulation experiments revealed that approximately 17% of the apparent cross-sectional rate of RNFLT loss is due to reduced scan quality associated with optical changes of the aging eye. Another 12% was due to thinning of the major blood vessels. Conclusions RNFLT declines by 4 μm per decade in healthy rhesus monkey eyes. This rate is approximately three times faster than loss of optic nerve axons. Approximately one-half of this difference is explained by optical degradation of the aging eye reducing SDOCT scan quality and thinning of the major blood vessels. Translational Relevance Current models used to predict retinal ganglion cell losses should be reconsidered. PMID:24932430
Association between sleep quality and nurse productivity among Korean clinical nurses.
Park, Eunok; Lee, Hyo Young; Park, Claire Su-Yeon
2018-06-01
To determine the association between sleep quality and nurse productivity. Although poor sleep quality may decrease nurses' productivity, the association between the two has not yet been evaluated in the literature. A cross-sectional survey was completed in May 2014 by 188 nurses working in acute hospitals in South Korea using the Pittsburgh Sleep Quality Index. Descriptive statistics, t tests, ANOVA, Pearson's correlation, and stepwise multiple regression were conducted for data analysis. The prevalence of poor sleep quality was high (79.8%). Among the components of sleep quality, sleep disturbances (β = -0.19) and subjective sleep quality (β = -0.16) were determined to be statistically significant predictive factors of nurse productivity, in addition to shift work (β = -0.20) and age (β = 0.32). Poor sleep quality may lead to lower nurse productivity. Nurse leaders and executives should consider measures to improve nurses' sleep quality and enhance nurse productivity. Steps that need to be considered include longer intervals between shift-work cycles, clockwise scheduling order, a longer break time after night shift work, allowing nurses to nap before / during a night shift, and providing a worksite healthy sleep programme. © 2018 John Wiley & Sons Ltd.
USDA-ARS?s Scientific Manuscript database
NHANES data indicate that two-thirds of U.S. adults consume less than the RDA for Mg. A low Mg intake or status has been associated with poor quality sleep and inflammatory stress. Thus, 100 adults (22 males and 78 females) older than 51 yr with a Pittsburgh Sleep Quality Index (PSQI) higher than 5 ...
Aspheric glass lens modeling and machining
NASA Astrophysics Data System (ADS)
Johnson, R. Barry; Mandina, Michael
2005-08-01
The incorporation of aspheric lenses in complex lens system can provide significant image quality improvement, reduction of the number of lens elements, smaller size, and lower weight. Recently, it has become practical to manufacture aspheric glass lenses using diamond-grinding methods. The evolution of the manufacturing technology is discussed for a specific aspheric glass lens. When a prototype all-glass lens system (80 mm efl, F/2.5) was fabricated and tested, it was observed that the image quality was significantly less than was predicted by the optical design software. The cause of the degradation was identified as the large aspheric element in the lens. Identification was possible by precision mapping of the spatial coordinates of the lens surface and then transforming this data into an appropriate optical surface defined by derived grid sag data. The resulting optical analysis yielded a modeled image consistent with that observed when testing the prototype lens system in the laboratory. This insight into a localized slope-error problem allowed improvements in the fabrication process to be implemented. The second fabrication attempt, the resulting aspheric lens provided remarkable improvement in the observed image quality, although still falling somewhat short of the desired image quality goal. In parallel with the fabrication enhancement effort, optical modeling of the surface was undertaken to determine how much surface error and error types were allowable to achieve the desired image quality goal. With this knowledge, final improvements were made to the fabrication process. The third prototype lens achieved the goal of optical performance. Rapid development of the aspheric glass lens was made possible by the interactive relationship between the optical designer, diamond-grinding personnel, and the metrology personnel. With rare exceptions, the subsequent production lenses were optical acceptable and afforded reasonable manufacturing costs.
YouTube provides irrelevant information for the diagnosis and treatment of hip arthritis.
Koller, Ulrich; Waldstein, Wenzel; Schatz, Klaus-Dieter; Windhager, Reinhard
2016-10-01
YouTube is increasingly becoming a key source for people to satisfy the need for additional information concerning their medical condition. This study analyses the completeness of accurate information found on YouTube pertaining to hip arthritis. The present study analyzed 133 YouTube videos using the search terms: hip arthritis, hip arthritis symptoms, hip arthritis diagnosis, hip arthritis treatment and hip replacement. Two quality assessment checklists with a scale of 0 to 12 points were developed to evaluate available video content for the diagnosis and the treatment of hip arthritis. Videos were grouped into poor quality (grade 0-3), moderate quality (grade 4-7) and excellent quality (grade 8-12), respectively. Three independent observers assessed all videos using the new grading system and independently scored all videos. Discrepancies regarding the categories were clarified by consensus discussion. For intra-observer reliabilities, grading was performed at two occasions separated by four weeks. Eighty-four percent (n = 112) had a poor diagnostic information quality, 14% (n = 19) a moderate quality and only 2% (n = 2) an excellent quality, respectively. In 86% (n = 114), videos provided poor treatment information quality. Eleven percent (n = 15) of videos had a moderate quality and only 3% (n = 4) an excellent quality, respectively. The present study demonstrates that YouTube is a poor source for accurate information pertaining to the diagnosis and treatment of hip arthritis. These finding are of high relevance for clinicians as videos are going to become the primary source of information for patients. Therefore, high quality educational videos are needed to further guide patients on the way from the diagnosis of hip arthritis to its proper treatment.
Nicotine dependence and sleep quality in young adults.
Dugas, E N; Sylvestre, M P; O'Loughlin, E K; Brunet, J; Kakinami, L; Constantin, E; O'Loughlin, J
2017-02-01
More cigarette smokers report poor sleep quality than non-smokers, but the association between nicotine dependence (ND) and sleep quality has not been well-characterized. The objective of this study was to describe the associations among frequency and intensity of cigarette smoking, ND symptoms, and sleep quality in young adults. Data on past-year smoking frequency, number of cigarettes smoked in the past month, five ND indicators (i.e., withdrawal, craving, self-medication symptoms, mFTQ, ICD-10 criteria for tobacco dependence), and sleep quality (measured with the Pittsburgh Sleep Quality Index (PSQI)) were collected in 2011-12 in self-report questionnaires completed by 405 young adult smokers (mean age 24 (0.6) years; 45% male; 45% daily smokers) participating in a longitudinal investigation of the natural course of ND. Associations between indicators of cigarette smoking, ND symptoms, and sleep quality were examined in multivariable logistic regression analyses controlling for age, sex, mother's education, and alcohol use. Thirty-six percent of participants reported poor sleep quality (PSQI>5). Higher cigarette consumption (OR(95% CI), 1.03(1.001-1.05)) but not frequency of past-year smoking, more frequent withdrawal symptoms (1.05(1.004-1.10)), more frequent cravings (1.05(1.004-1.10)), higher mFTQ scores (1.14(1.02-1.27)), and endorsing more ICD-10 criteria for tobacco dependence (1.19(1.04-1.36)) were also associated with poor sleep quality. Cigarette smoking and ND symptoms are associated with poor sleep quality in young adult smokers. Advice from practitioners to cut back on number of cigarettes smoked per day and treatment of ND symptoms may improve sleep quality in young adult smokers. Copyright © 2016 Elsevier Ltd. All rights reserved.
Wavefront control of large optical systems
NASA Technical Reports Server (NTRS)
Meinel, Aden B.; Meinel, Marjorie P.; Breckinridge, J. B.
1990-01-01
Several levels of wavefront control are necessary for the optimum performance of very large telescopes, especially segmented ones like the Large Deployable Reflector. In general, the major contributors to wavefront error are the segments of the large primary mirror. Wavefront control at the largest optical surface may not be the optimum choice because of the mass and inaccessibility of the elements of this surface that require upgrading. The concept of two-stage optics was developed to permit a poor wavefront from the large optics to be upgraded by means of a wavefront corrector at a small exit pupil of the system.
Cavity-Enhanced Optical Readout of a Single Solid-State Spin
NASA Astrophysics Data System (ADS)
Sun, Shuo; Kim, Hyochul; Solomon, Glenn S.; Waks, Edo
2018-05-01
We demonstrate optical readout of a single spin using cavity quantum electrodynamics. The spin is based on a single trapped electron in a quantum dot that has a poor branching ratio of 0.43. Selectively coupling one of the optical transitions of the quantum dot to the cavity mode results in a spin-dependent cavity reflectivity that enables spin readout by monitoring the reflected intensity of an incident optical field. Using this approach, we demonstrate spin-readout fidelity of 0.61. Achieving this fidelity using resonance fluorescence from a bare dot would require 43 times improvement in photon collection efficiency.
Diffractive optical element in materials testing
NASA Astrophysics Data System (ADS)
Silvennoinen, Raimo V. J.; Peiponen, Kai-Erik
1998-09-01
The object of this paper is to present a sensor based on diffractive optics that can be applied for the materials testing. The present sensor, which is based on the use of a computer-generated hologram (CGH) exploits the holographic imagery. The CGH-sensor was introduced for inspection of surface roughness and flatness of metal surfaces. The results drawn out by the present sensor are observed to be in accordance with the experimental data. Together with the double exposure holographic interferometry (DEHI) and digital electronic speckle pattern interferometry (DSPI) in elasticity inspection, the sensor was applied for the investigations of surface quality of opaque fragile materials, which are pharmaceutical compacts. The optical surface quality was observed to be related to the porosity of the pharmaceutical tablets. The CGH-sensor was also applied for investigations of optical quality of thin films as PLZT ceramics and coating of pharmaceutical compacts. The surfaces of PLZT samples showed fluctuations in optical curvature, and wedgeness for all the cases studied. For pharmaceutical compacts, the optical signals were observed to depend to a great extent on the optical constants of the coatings and the substrates, and in addition to the surface porosity under the coating.
Development and evaluation of optical fiber NH3 sensors for application in air quality monitoring
NASA Astrophysics Data System (ADS)
Huang, Yu; Wieck, Lucas; Tao, Shiquan
2013-02-01
Ammonia is a major air pollutant emitted from agricultural practices. Sources of ammonia include manure from animal feeding operations and fertilizer from cropping systems. Sensor technologies with capability of continuous real time monitoring of ammonia concentration in air are needed to qualify ammonia emissions from agricultural activities and further evaluate human and animal health effects, study ammonia environmental chemistry, and provide baseline data for air quality standard. We have developed fiber optic ammonia sensors using different sensing reagents and different polymers for immobilizing sensing reagents. The reversible fiber optic sensors have detection limits down to low ppbv levels. The response time of these sensors ranges from seconds to tens minutes depending on transducer design. In this paper, we report our results in the development and evaluation of fiber optic sensor technologies for air quality monitoring. The effect of change of temperature, humidity and carbon dioxide concentration on fiber optic ammonia sensors has been investigated. Carbon dioxide in air was found not interfere the fiber optic sensors for monitoring NH3. However, the change of humidity can cause interferences to some fiber optic NH3 sensors depending on the sensor's transducer design. The sensitivity of fiber optic NH3 sensors was found depends on temperature. Methods and techniques for eliminating these interferences have been proposed.
Siegrist, Johannes; Wahrendorf, Morten; von dem Knesebeck, Olaf; Jürges, Hendrik; Börsch-Supan, Axel
2007-02-01
Given the challenge of a high proportion of older employees who retire early from work we analyse associations of indicators of a poor psychosocial quality of work with intended premature departure from work in a large sample of older male and female employees in 10 European countries. Baseline data from the 'Survey of Health, Ageing and Retirement in Europe' (SHARE) were obtained from 3523 men and 3318 women in 10 European countries. Data on intended early retirement, four measures of well-being (self-rated health, depressive symptoms, general symptom load, and quality of life), and quality of work (effort-reward imbalance; low control at work) were obtained from structured interviews and questionnaires. Country-specific and total samples are analysed, using logistic regression analysis. Poor quality of work is significantly associated with intended early retirement. After adjustment for well-being odds ratios (OR) of effort-reward imbalance [OR 1.72 (1.43-2.08)] and low control at work [OR 1.51 (1.27-1.80)] on intended early retirement are observed. Poor quality of work and reduced well-being are independently associated with the intention to retire from work. The consistent association of a poor psychosocial quality of work with intended early retirement among older employees across all European countries under study calls for improved investments into better quality of work, in particular increased control and an appropriate balance between efforts spent and rewards received at work.
Impact of image quality on OCT angiography based quantitative measurements.
Al-Sheikh, Mayss; Ghasemi Falavarjani, Khalil; Akil, Handan; Sadda, SriniVas R
2017-01-01
To study the impact of image quality on quantitative measurements and the frequency of segmentation error with optical coherence tomography angiography (OCTA). Seventeen eyes of 10 healthy individuals were included in this study. OCTA was performed using a swept-source device (Triton, Topcon). Each subject underwent three scanning sessions 1-2 min apart; the first two scans were obtained under standard conditions and for the third session, the image quality index was reduced using application of a topical ointment. En face OCTA images of the retinal vasculature were generated using the default segmentation for the superficial and deep retinal layer (SRL, DRL). Intraclass correlation coefficient (ICC) was used as a measure for repeatability. The frequency of segmentation error, motion artifact, banding artifact and projection artifact was also compared among the three sessions. The frequency of segmentation error, and motion artifact was statistically similar between high and low image quality sessions (P = 0.707, and P = 1 respectively). However, the frequency of projection and banding artifact was higher with a lower image quality. The vessel density in the SRL was highly repeatable in the high image quality sessions (ICC = 0.8), however, the repeatability was low, comparing the high and low image quality measurements (ICC = 0.3). In the DRL, the repeatability of the vessel density measurements was fair in the high quality sessions (ICC = 0.6 and ICC = 0.5, with and without automatic artifact removal, respectively) and poor comparing high and low image quality sessions (ICC = 0.3 and ICC = 0.06, with and without automatic artifact removal, respectively). The frequency of artifacts is higher and the repeatability of the measurements is lower with lower image quality. The impact of image quality index should be always considered in OCTA based quantitative measurements.
Nakakubo, Sho; Makizako, Hyuma; Doi, Takehiko; Tsutsumimoto, Kota; Lee, Sangyoon; Lee, Sungchul; Hotta, Ryo; Bae, Seongryu; Suzuki, Takao; Shimada, Hiroyuki
2017-11-01
The purpose of the present study was to examine whether the combination of subjective sleep quality and physical activity is associated with cognitive performance among community-dwelling older adults. Cross-sectional data on 5381 older adults who participated in part of the National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes were analyzed. We assessed general cognitive impairment using the Mini-Mental State Examination, and also assessed story memory, attention, executive function and processing speed using the National Center for Geriatrics and Gerontology Functional Assessment Tool. Physical activity was assessed using two questionnaires, and participants were categorized as active or inactive. Sleep quality was assessed using the Pittsburgh Sleep Quality Index, and participants were categorized as having poor (PS) or good sleep quality (GS). Participants in the inactive + PS group had worse performances than those in the active + GS group in all cognitive measures (Mini-Mental State Examination: P = 0.008, story memory: P = 0.007, other cognitive measures: P < 0.001), and also had worse performances than those in the inactive + GS and active + PS groups in the trail-making test, part B, and the symbol digit substitution test (P < 0.001, respectively). Additionally, participants in the inactive + GS group had worse performances than in the active + GS in the trail-making test, part B, and the symbol digit substitution test (P = 0.002 and P = 0.001, respectively). Inactivity and poor sleep quality were associated with poor cognitive performance among community-dwelling older adults. The combination of poor sleep quality and physical inactivity also worsened cognitive performance. Geriatr Gerontol Int 2017; 17: 1823-1828. © 2017 Japan Geriatrics Society.
Electroforming of optical tooling in high-strength Ni-Co alloy
NASA Astrophysics Data System (ADS)
Stein, Berl
2003-05-01
Plastic optics are often mass produced by injection, compression or injection-compression molding. Optical quality molds can be directly machined in appropriate materials (tool steels, electroless nickel, aluminum, etc.), but much greater cost efficiency can be achieved with electroformed modl inserts. Traditionally, electroforming of optical quality mold inserts has been carried out in nickel, a material much softer than tool steels which, when hardened to 45 - 50 HRc usually exhibit high wear resistance and long service life (hundreds of thousands of impressions per mold). Because of their low hardness (< 20 HRc), nickel molds can produce only tens of thousands of parts before they are scrapped due to wear or accidental damage. This drawback prevented their wider usage in general plastic and optical mold making. Recently, NiCoForm has developed a proprietary Ni-CO electroforming bath combining the high strength and wear resistance of the alloy with the low stress and high replication fidelity typical of pure nickel electroforming. This paper will outline the approach to electroforming of optical quality tooling in low stress, high strength Ni-Co alloy and present several examples of electroformed NiColoy mold inserts.
Multiwavelength digital holography for polishing tool shape measurement
NASA Astrophysics Data System (ADS)
Lédl, Vít.; Psota, Pavel; Václavík, Jan; Doleček, Roman; Vojtíšek, Petr
2013-09-01
Classical mechano-chemical polishing is still a valuable technique, which gives unbeatable results for some types of optical surfaces. For example, optics for high power lasers requires minimized subsurface damage, very high cosmetic quality, and low mid spatial frequency error. One can hardly achieve this with use of subaperture polishing. The shape of the polishing tool plays a crucial role in achieving the required form of the optical surface. Often the shape of the polishing tool or pad is not known precisely enough during the manufacturing process. The tool shape is usually premachined and later is changed during the polishing procedure. An experienced worker could estimate the shape of the tool indirectly from the shape of the polished element, and that is why he can achieve the required shape in few reasonably long iterative steps. Therefore the lack of the exact tool shape knowledge is tolerated. Sometimes, this indirect method is not feasible even if small parts are considered. Moreover, if processes on machines like planetary (continuous) polishers are considered, the incorrect shape of the polishing pad could extend the polishing times extremely. Every iteration step takes hours. Even worse, polished piece could be wasted if the pad has a poor shape. The ability of the tool shape determination would be very valuable in those types of lengthy processes. It was our primary motivation to develop a contactless measurement method for large diffusive surfaces and demonstrate its usability. The proposed method is based on application of multiwavelength digital holographic interferometry with phase shift.
NASA Astrophysics Data System (ADS)
Ma, Y.; Liu, S.
2017-12-01
Accurate estimation of surface evapotranspiration (ET) with high quality is one of the biggest obstacles for routine applications of remote sensing in eco-hydrological studies and water resource management at basin scale. However, many aspects urgently need to deeply research, such as the applicability of the ET models, the parameterization schemes optimization at the regional scale, the temporal upscaling, the selecting and developing of the spatiotemporal data fusion method and ground-based validation over heterogeneous land surfaces. This project is based on the theoretically robust surface energy balance system (SEBS) model, which the model mechanism need further investigation, including the applicability and the influencing factors, such as local environment, and heterogeneity of the landscape, for improving estimation accuracy. Due to technical and budget limitations, so far, optical remote sensing data is missing due to frequent cloud contamination and other poor atmospheric conditions in Southwest China. Here, a multi-source remote sensing data fusion method (ESTARFM: Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model) method will be proposed through blending multi-source remote sensing data acquired by optical, and passive microwave remote sensors on board polar satellite platforms. The accurate "all-weather" ET estimation will be carried out for daily ET of the River Source Region in Southwest China, and then the remotely sensed ET results are overlapped with the footprint-weighted images of EC (eddy correlation) for ground-based validation.
Bio-optical water quality dynamics observed from MERIS in Pensacola Bay, Florida
Observed bio-optical water quality data collected from 2009 to 2011 in Pensacola Bay, Florida were used to develop empirical remote sensing retrieval algorithms for chlorophyll a (Chla), colored dissolved organic matter (CDOM), and suspended particulate matter (SPM). Time-series ...
ERIC Educational Resources Information Center
Lorber, Michael F.; Egeland, Byron
2009-01-01
Developmental models and previous findings suggest that early parenting is more strongly associated with externalizing problems in early childhood than it is in adolescence. In this article, the authors address whether the association of poor-quality infancy parenting and externalizing problems "rebounds" in adulthood. Poor-quality infancy…
ERIC Educational Resources Information Center
Concepcion, Tessa; Barbosa, Clarita; Vélez, Juan Carlos; Pepper, Micah; Andrade, Asterio; Gelaye, Bizu; Yanez, David; Williams, Michelle A.
2014-01-01
Objectives: To evaluate whether daytime sleepiness, poor sleep quality, and morningness and eveningness preferences are associated with common mental disorders (CMDs) among college students. Methods: A total of 963 college students completed self-administered questionnaires that collected information about sociodemographic characteristics, sleep…
Numerical simulation of deformation and figure quality of precise mirror
NASA Astrophysics Data System (ADS)
Vit, Tomáš; Melich, Radek; Sandri, Paolo
2015-01-01
The presented paper shows results and a comparison of FEM numerical simulations and optical tests of the assembly of a precise Zerodur mirror with a mounting structure for space applications. It also shows how the curing of adhesive film can impact the optical surface, especially as regards deformations. Finally, the paper shows the results of the figure quality analysis, which are based on data from FEM simulation of optical surface deformations.
Tomperi, Jani; Leiviskä, Kauko
2018-06-01
Traditionally the modelling in an activated sludge process has been based on solely the process measurements, but as the interest to optically monitor wastewater samples to characterize the floc morphology has increased, in the recent years the results of image analyses have been more frequently utilized to predict the characteristics of wastewater. This study shows that the traditional process measurements or the automated optical monitoring variables by themselves are not capable of developing the best predictive models for the treated wastewater quality in a full-scale wastewater treatment plant, but utilizing these variables together the optimal models, which show the level and changes in the treated wastewater quality, are achieved. By this early warning, process operation can be optimized to avoid environmental damages and economic losses. The study also shows that specific optical monitoring variables are important in modelling a certain quality parameter, regardless of the other input variables available.
Retinitis and optic neuritis in a child with chickenpox: case report and review of literature.
Tappeiner, Christoph; Aebi, Christoph; Garweg, Justus G
2010-12-01
In immunocompetent individuals, necrotizing retinopathy is a rare complication of chickenpox. Herein, we report on a 3-year-old immunocompetent boy who developed retinitis and optic neuritis 3 days after the onset of chickenpox and compare the findings to published cases. Since macula and optic nerve were affected, visual acuity remained poor. An early diagnosis and treatment of ocular manifestations in chickenpox is imperative for the preservation of a residual visual function and prevention of blinding secondary complications.
A Tiered Analytical Approach for Investigating Poor Quality Emergency Contraceptives
Monge, María Eugenia; Dwivedi, Prabha; Zhou, Manshui; Payne, Michael; Harris, Chris; House, Blaine; Juggins, Yvonne; Cizmarik, Peter; Newton, Paul N.; Fernández, Facundo M.; Jenkins, David
2014-01-01
Reproductive health has been deleteriously affected by poor quality medicines. Emergency contraceptive pills (ECPs) are an important birth control method that women can use after unprotected coitus for reducing the risk of pregnancy. In response to the detection of poor quality ECPs commercially available in the Peruvian market we developed a tiered multi-platform analytical strategy. In a survey to assess ECP medicine quality in Peru, 7 out of 25 different batches showed inadequate release of levonorgestrel by dissolution testing or improper amounts of active ingredient. One batch was found to contain a wrong active ingredient, with no detectable levonorgestrel. By combining ultrahigh performance liquid chromatography-ion mobility spectrometry-mass spectrometry (UHPLC-IMS-MS) and direct analysis in real time MS (DART-MS) the unknown compound was identified as the antibiotic sulfamethoxazole. Quantitation by UHPLC-triple quadrupole tandem MS (QqQ-MS/MS) indicated that the wrong ingredient was present in the ECP sample at levels which could have significant physiological effects. Further chemical characterization of the poor quality ECP samples included the identification of the excipients by 2D Diffusion-Ordered Nuclear Magnetic Resonance Spectroscopy (DOSY 1H NMR) indicating the presence of lactose and magnesium stearate. PMID:24748219
QUALITY OF LIFE AND HEALTH SELF-PERCEPTION IN CHILDREN WITH POOR SCHOOL PERFORMANCE.
Rezende, Bárbara Antunes; Lemos, Stela Maris Aguiar; Medeiros, Adriane Mesquita de
2017-01-01
To examine the association between quality of life and health self-perception of children with poor school performance, considering sociodemographic factors. An analytical, observational, cross-sectional study was conducted with 99 children aged 7 to 12 years receiving specialized educational assistance. Parents and legal guardians answered questions concerning the sociodemographic profile. For an assessment of the quality of life and proposed domains (autonomy, functioning, leisure, and family), the children completed the Autoquestionnarie Qualité de Vie Enfant Imagé (AUQEI) and answered a question concerning their self-perceived health. Data were analyzed using multiple linear regression, considering a 5% significance level. Among the evaluated children, 69 (69.7%) male participants with mean age of 8.7±1.5, 27% self-assessed their health status as poor/very poor, and 36.4% of the children reported having impaired quality of life. As for the domains assessed by AUQEI, there was statistical significance in the associations between family with age, autonomy with economic classification, and leisure and functioning with self-perceived health. The quality of life of children with academic underachievement is associated with their health self-perception and sociodemographic characteristics.
A method of rapidly evaluating image quality of NED optical system
NASA Astrophysics Data System (ADS)
Sun, Qi; Qiu, Chuankai; Yang, Huan
2014-11-01
In recent years, with the development of technology of micro-display, advanced optics and the software and hardware, near-to-eye display ( NED) optical system will have a wide range of potential applications in the fields of amusement and virtual reality. However, research on the evaluating image quality of this kind optical system is comparatively lagging behind. Although now there are some methods and equipment for evaluation, they can't be applied in commercial production because of their complex operation and inaccuracy. In this paper, an academic method is proposed and a Rapid Evaluation System (RES) is designed to evaluate the image of optical system rapidly and exactly. Firstly, a set of parameters that eyes are sensitive to and also express the quality of system should be extracted and quantized to be criterion, so the evaluation standards can be established. Then, some parameters can be detected by RES consisted of micro-display, CCD camera and computer and so on. By process of scaling, the measuring results of the RES are exact and creditable, relationship between object measurement, subjective evaluation and the RES will be established. After that, image quality of optical system can be evaluated just by detecting parameters of that. The RES is simple and the results of evaluation are exact and keeping with human vision. So the method can be used not only for optimizing design of optical system, but also for evaluation in commercial production.
Kleindienst, Roman; Kampmann, Ronald; Stoebenau, Sebastian; Sinzinger, Stefan
2011-07-01
The performance of optical systems is typically improved by increasing the number of conventionally fabricated optical components (spheres, aspheres, and gratings). This approach is automatically connected to a system enlargement, as well as potentially higher assembly and maintenance costs. Hybrid optical freeform components can help to overcome this trade-off. They merge several optical functions within fewer but more complex optical surfaces, e.g., elements comprising shallow refractive/reflective and high-frequency diffractive structures. However, providing the flexibility and precision essential for their realization is one of the major challenges in the field of optical component fabrication. In this article we present tailored integrated machining techniques suitable for rapid prototyping as well as the fabrication of molding tools for low-cost mass replication of hybrid optical freeform components. To produce the different feature sizes with optical surface quality, we successively combine mechanical machining modes (ultraprecision micromilling and fly cutting) with precisely aligned direct picosecond laser ablation in an integrated fabrication approach. The fabrication accuracy and surface quality achieved by our integrated fabrication approach are demonstrated with profilometric measurements and experimental investigations of the optical performance.
Optical parametric osicllators with improved beam quality
Smith, Arlee V.; Alford, William J.
2003-11-11
An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.
Developing a more useful surface quality metric for laser optics
NASA Astrophysics Data System (ADS)
Turchette, Quentin; Turner, Trey
2011-02-01
Light scatter due to surface defects on laser resonator optics produces losses which lower system efficiency and output power. The traditional methodology for surface quality inspection involves visual comparison of a component to scratch and dig (SAD) standards under controlled lighting and viewing conditions. Unfortunately, this process is subjective and operator dependent. Also, there is no clear correlation between inspection results and the actual performance impact of the optic in a laser resonator. As a result, laser manufacturers often overspecify surface quality in order to ensure that optics will not degrade laser performance due to scatter. This can drive up component costs and lengthen lead times. Alternatively, an objective test system for measuring optical scatter from defects can be constructed with a microscope, calibrated lighting, a CCD detector and image processing software. This approach is quantitative, highly repeatable and totally operator independent. Furthermore, it is flexible, allowing the user to set threshold levels as to what will or will not constitute a defect. This paper details how this automated, quantitative type of surface quality measurement can be constructed, and shows how its results correlate against conventional loss measurement techniques such as cavity ringdown times.
Senol, Vesile; Soyuer, Ferhan; Guleser, Gulsum Nihal; Argun, Mahmut; Avsarogullari, Levent
2014-12-01
Sleep adequacy is one of the major determinants of a successful professional life. The aim of this study is to determine the sleep quality of emergency health workers and analyze its effects on their professional and social lives. The study was carried out on 121 voluntary emergency health workers in 112 Emergency Aid Stations in Kayseri, Turkey, in 2011. The data was collected through the Socio-Demographics Form and the Pittsburgh Sleep Quality Index (PSQI) and analyzed via SPSS 18.00. The statistical analysis involved percentage and frequency distributions, mean±standard deviations, a chi-square test, correlations, and logistic regression analysis. The mean score of the participants according to the Pittsburgh Sleep Quality Index was 4.14±3.09, and 28.9% of participants had poor sleep quality. Being single and being a woman accounted for 11% (p=0.009, 95% CI: 0.111-0.726) and 7% (p=0.003, 95% CI: 0.065-0.564) of poor sleep quality respectively. There was a positive correlation between sleep quality scores and negative effects on professional and social life activities. Negative effects on professional activities included increased loss of attention and concentration (40.0%, p=0,016), increased failure to take emergency actions (57.9%, p=0.001), reduced motivation (46.2%, p=0.004), reduced performance (41.4%, p=0.024), and low work efficiency (48.1%, p=0.008). Poor sleep quality generally negatively affected the daily life of the workers (51.6%, p=0.004), restricted their social life activities (45.7%, p=0.034), and caused them to experience communication difficulties (34.7%, p=0.229). One third of the emergency health workers had poor sleep quality and experienced high levels of sleep deficiency. Being a woman and being single were the most important factors in low sleep quality. Poor sleep quality continuously affected daily life and professional life negatively by leading to a serious level of fatigue, loss of attention-concentration, and low levels of motivation, performance and efficiency.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sivakumar, R; Janardhan, N; Bhavani, P
Purpose: To compare the plan quality and performance of Simultaneous Integrated Boost (SIB) Treatment plan between Seven field (7F) and Nine field(9F) Intensity Modulated Radiotherapies and Single Arc (SA) and Dual Arc (DA) Volumetric Modulated Arc Therapy( VMAT). Methods: Retrospective planning study of 16 patients treated in Elekta Synergy Platform (mlci2) by 9F-IMRT were replanned with 7F-IMRT, Single Arc VMAT and Dual Arc VMAT using CMS, Monaco Treatment Planning System (TPS) with Monte Carlo simulation. Target delineation done as per Radiation Therapy Oncology Protocols (RTOG 0225&0615). Dose Prescribed as 70Gy to Planning Target Volumes (PTV70) and 61Gy to PTV61 inmore » 33 fraction as a SIB technique. Conformity Index(CI), Homogeneity Index(HI) were used as analysis parameter for Target Volumes as well as Mean dose and Max dose for Organ at Risk(OAR,s).Treatment Delivery Time(min), Monitor unit per fraction (MU/fraction), Patient specific quality assurance were also analysed. Results: A Poor dose coverage and Conformity index (CI) was observed in PTV70 by 7F-IMRT among other techniques. SA-VMAT achieved poor dose coverage in PTV61. No statistical significance difference observed in OAR,s except Spinal cord (P= 0.03) and Right optic nerve (P=0.03). DA-VMAT achieved superior target coverage, higher CI (P =0.02) and Better HI (P=0.03) for PTV70 other techniques (7F-IMRT/9F-IMRT/SA-VMAT). A better dose spare for Parotid glands and spinal cord were seen in DA-VMAT. The average treatment delivery time were 5.82mins, 6.72mins, 3.24mins, 4.3mins for 7F-IMRT, 9F-IMRT, SA-VMAT and DA-VMAT respectively. Significance difference Observed in MU/fr (P <0.001) and Patient quality assurance pass rate were >95% (Gamma analysis (Γ3mm, 3%). Conclusion: DA-VAMT showed better target dose coverage and achieved better or equal performance in sparing OARs among other techniques. SA-VMAT offered least Treatment Time than other techniques but achieved poor target coverage. DA-VMAT offered shorter delivery time than 7F-IMRT and 9F-IMRT without compromising the plan quality.« less
Emotional memory processing is influenced by sleep quality.
Tempesta, Daniela; De Gennaro, Luigi; Natale, Vincenzo; Ferrara, Michele
2015-07-01
The recall of emotional memory is enhanced after sleep and is hindered by sleep deprivation. We used an emotional memory task to assess whether poor sleep quality, as well as sleep deprivation, may influence the accuracy of memory recognition, but also the affective tone associated with the memory. Seventy-five subjects, divided into poor sleeper (PS), good sleeper (GS), and sleep deprivation (SD) groups, completed two recall (R) sessions: R1, 1 h after the encoding phase; and R2, after one night of sleep for PS and GS groups and after one night of sleep deprivation for the SD group. During the encoding phase, the participants rated valence and arousal of 90 pictures. During R1 and R2, the participants first made a yes/no memory judgment of the 45 target pictures intermingled with 30 non-target pictures, then rated valence and arousal of each picture. Recognition accuracy was higher for the PS and GS groups compared to the SD group for all pictures. Emotional valence of the remembered pictures was more negative after sleep deprivation and poor quality sleep, while it was preserved after a good sleep. These results provide the first evidence that poor sleep quality negatively affects emotional valence of memories, within the context of preserved emotional memory consolidation. It is suggested that low sleep quality and lack of sleep may impose a more negative affective tone to memories. The reported effects are not to be ascribed to depressive mood, but to a specific influence of poor sleep quality. Copyright © 2015 Elsevier B.V. All rights reserved.
Wu, Xiaoyan; Tao, Shuman; Zhang, Yukun; Zhang, Shichen; Tao, Fangbiao
2015-01-01
To test the independent and interactive associations of physical activity (PA) and screen time (ST) with self-reported mental health and sleep quality among Chinese college students. Data were collected in October, 2013. The gender, age, residential background, body mass index (BMI), perceived family economy and perceived study burden were obtained from a total of 4747 college students (41.6% males and 58.4% females). The outcomes were self-reported PA status, ST, anxiety, depression, psychopathological symptoms and sleep quality. Analyses were conducted with logistic regression models. Overall, 16.3%, 15.9% and 17.3% of the students had psychological problems, such as anxiety, depression and psychopathological symptoms, respectively. The prevalence of poor sleep quality was 9.8%. High ST was significantly positively associated with anxiety (OR=1.38, 95%CI: 1.15-1.65), depression (OR=1.76, 95%CI: 1.47-2.09), psychopathological symptoms (OR=1.69, 95%CI: 1.43-2.01) and poor sleep quality (OR=1.32, 95%CI: 1.06-1.65). High PA was insignificantly negatively associated with anxiety, depression, psychopathological symptoms and poor sleep. Low PA and high ST were independently and interactively associated with increased risks of mental health problems and poor sleep quality (p<0.05 for all). Interventions are needed to reduce ST and increase PA in the lifestyles of young people. Future research should develop and measure the impacts of interventions and their potential consequences on sleep, health, and well being.
Absolute Infrared Intensities and Interstellar Ice Abundances- From Neutrals to Ions
NASA Astrophysics Data System (ADS)
Gerakines, Perry
Infrared (IR) telescopes, such as Spitzer and SOFIA, have revealed a rich variety of chemical species trapped in interstellar ices. However, quantifying the abundances of these species has been difficult because some molecules, such as formaldehyde (H2CO), and some ions, such as ammonium (NH4+), have poorly-known IR optical parameters, such as band strengths and optical constants. In the case of NH4+, the most widely used band-intensity values are from a mere two measurements published over a decade ago. Those two experiments cannot be repeated or checked as the original publication provided no information on reaction temperature, heating rate, spectral resolution, and so forth, and the two authors are no longer active in the field. Moreover, neither kinetic data nor statistics on the two measurements were provided, clearly an unsatisfactory situation. Exacerbating the problem is that NH4+ is sometimes used as a check on the IR spectral intensities of other ions, such as OCN- (cyanate), which has its own checkered past. We propose to correct these problems associated with abundance determinations of selected interstellar ices. We will combine two recent successful efforts from our laboratory and measure band intensities for NH4+ and OCN-, as well as HCOO- (formate). To unravel the interstellar formate band requires that we also properly determine its spectral baseline to distinguish from co-absorbing species, primarily formaldehyde (H2CO). Since the latter also has, at best, poorly-determined IR absolute intensities, we will measure them at multiple temperatures and ice phases for this project. This work will build on our recent success in deriving optical constants from IR spectra for interstellar hydrocarbon and nitrile ices (Hudson et al., 2014a, 2014b), and in generating NH4+ in situ for a study of Jupiter's atmosphere (Loeffler and Hudson, 2015). As a bonus, the proposed measurements also will enable the determination of band-strengths for such ions as CN-, NO3-, HS-, and ClO4-. High-quality IR intensities of neutral covalently-bonded ice molecules have been measured and published by our team. We now propose to make the transition to ions.
Imaging quality evaluation method of pixel coupled electro-optical imaging system
NASA Astrophysics Data System (ADS)
He, Xu; Yuan, Li; Jin, Chunqi; Zhang, Xiaohui
2017-09-01
With advancements in high-resolution imaging optical fiber bundle fabrication technology, traditional photoelectric imaging system have become ;flexible; with greatly reduced volume and weight. However, traditional image quality evaluation models are limited by the coupling discrete sampling effect of fiber-optic image bundles and charge-coupled device (CCD) pixels. This limitation substantially complicates the design, optimization, assembly, and evaluation image quality of the coupled discrete sampling imaging system. Based on the transfer process of grayscale cosine distribution optical signal in the fiber-optic image bundle and CCD, a mathematical model of coupled modulation transfer function (coupled-MTF) is established. This model can be used as a basis for following studies on the convergence and periodically oscillating characteristics of the function. We also propose the concept of the average coupled-MTF, which is consistent with the definition of traditional MTF. Based on this concept, the relationships among core distance, core layer radius, and average coupled-MTF are investigated.
Analysis of nonreciprocal noise based on mode splitting in a high-Q optical microresonator
NASA Astrophysics Data System (ADS)
Yang, Zhaohua; Xiao, Yarong; Huo, Jiayan; Shao, Hui
2018-01-01
The whispering gallery mode optical microresonator offers a high quality factor, which enables it to act as the core component of a high sensitivity resonator optic gyro; however, nonreciprocal noise limits its precision. Considering the Sagnac effect, i.e. mode splitting in high-quality optical micro-resonators, we derive the explicit expression for the angular velocity versus the splitting amount, and verify the sensing mechanism by simulation using finite element method. Remarkably, the accuracy of the angular velocity measurement in the whispering gallery mode optical microresonator with a quality factor of 108 is 106 °/s. We obtain the optimal coupling position of the novel angular velocity sensing system by detecting the output transmittance spectra of different vertical coupling distances and axial coupling positions. In addition, the reason for the nonreciprocal phenomenon is determined by theoretical analysis of the evanescent distribution of a tapered fiber. These results will provide an effective method and a theoretical basis for suppression of the nonreciprocal noise.
ISTC Projects from RFNC-VNIIEF Devoted to Improving Laser Beam Quality
NASA Astrophysics Data System (ADS)
Starikov, F.; Kochemasov, G.
Information is given about the Projects # 1929 and # 2631 supported by ISTC and concerned with improving laser beam quality and interesting for adaptive optics community. One of them, Project # 1929 has been recently finished. It has been devoted to development of an SBS phase conjugation mirror of superhigh conjugation quality employing the kinoform optics for high-power lasers with nanosecond scale pulse duration. With the purpose of reaching ideal PC fidelity, the SBS mirror includes the raster of small lenses that has been traditionally used as the lenslet in Shack-Hartmann wavefront sensor in adaptive optics. The second of them, Project # 2631, is concerned with the development of an adaptive optical system for phase correction of laser beams with wavefront vortex. The principles of operation of modern adaptive systems are based on the assumption that the phase is a smooth continuous function in space. Therefore the solution of the Project tasks will assume a new step in adaptive optics.
Shen, Chan; Sambamoorthi, Usha
2012-01-01
The authors of this study examined the association between health-related quality of life and financial barriers to care, defined as not getting the needed care due to cost considerations. To better understand health-related quality of life among women veterans, the authors compared women veterans to women non-veterans. The authors conducted cross-sectional analyses using data from the 2009 Behavioral Risk Factor Surveillance System survey. The authors assessed four health-related quality of life measures: (1) general health; (2) physical health; (3) mental health; and (4) functional status. The authors performed multinomial logistic regressions to examine the relationship between financial barriers to receiving healthcare and health-related quality of life measures after controlling for other independent variables. The authors included women veterans not in active military duty (N = 3,747) and a matched sample of women non-veterans (N = 3,747), selected using a propensity score method so that they would have distributions of demographic and socioeconomic characteristics similar to those of the veterans. Overall, 14% of women reported financial barriers. Women who reported financial barriers to receiving healthcare were more likely to have poor health-related quality of life in all four dimensions than those who did not report such barriers. Compared to women non-veterans, women veterans did not differ in reported financial barriers but were more likely to report poor health-related quality of life. Reporting financial barriers to receiving needed healthcare was significantly associated with poor health-related quality of life among women. Veteran status was also significantly associated with poor health-related quality of life. These findings suggest the need for healthcare policy makers and practitioners to align emerging new models of healthcare delivery to improve health-related quality of life for women veterans.
2015-01-01
Ensuring that artemisinin-containing antimalarials (ACAs) are of good quality is a key component of effective malaria treatment. There are concerns that a high proportion of ACAs are falsified or substandard, though estimates are rarely based on representative data. During a nationally representative survey in Tanzania, ACAs were purchased from private retail drug outlets, and the active pharmaceutical ingredient (API) was measured. All 1,737 ACAs contained the labeled artemisinin derivative, with 4.1% being outside the 85–115% artemisinin API range defined as acceptable quality. World Health Organization (WHO) prequalified drugs had 0.1 times the odds of being poor quality compared with non-prequalified ACAs for the artemisinin component. When partner components of combination therapies were also considered, 12.1% were outside the acceptable API range, and WHO prequalified ACAs had 0.04 times the odds of being poor quality. Although the prevalence of poor quality ACAs was lower than reported elsewhere, the minority of samples found to be substandard is a cause for concern. Improvements in quality could be achieved by increasing the predominance of WHO prequalified products in the market. Continued monitoring of quality standards is essential. PMID:25897065
NASA Technical Reports Server (NTRS)
Frese, Erich A.; Chiragh, Furqan L.; Switzer, Robert; Vasilyev, Aleksey A.; Thomes, Joe; Coyle, D. Barry; Stysley, Paul R.
2018-01-01
Flight quality solid-state lasers require a unique and extensive set of testing and qualification processes, both at the system and component levels to insure the laser's promised performance. As important as the overall laser transmitter design is, the quality and performance of individual subassemblies, optics, and electro-optics dictate the final laser unit's quality. The Global Ecosystem Dynamics Investigation (GEDI) laser transmitters employ all the usual components typical for a diode-pumped, solid-state laser, yet must each go through their own individual process of specification, modeling, performance demonstration, inspection, and destructive testing. These qualification processes and results for the laser crystals, laser diode arrays, electro-optics, and optics, will be reviewed as well as the relevant critical issues encountered, prior to their installation in the GEDI flight laser units.
Santos, Ana R; Costa, Miguel Â; Schwartz, Christian; Alves, Dalila; Figueira, João; Silva, Rufino; Cunha-Vaz, Jose G
2018-06-01
To identify baseline optical coherence tomography morphologic characteristics predicting the visual response to anti-vascular endothelial growth factor therapy in diabetic macular edema. Sixty-seven patients with diabetic macular edema completed a prospective, observational study (NCT01947881-CHARTRES). All patients received monthly intravitreal injections of Lucentis for 3 months followed by PRN treatment and underwent best-corrected visual acuity measurements and spectral domain optical coherence tomography at Baseline, Months 1, 2, 3, and 6. Visual treatment response was characterized as good (≥10 letters), moderate (5-10 letters), and poor (<5 or letters loss). Spectral domain optical coherence tomography images were graded before and after treatment by a certified Reading Center. One month after loading dose, 26 patients (38.80%) were identified as good responders, 19 (28.35%) as Moderate and 22 (32.83%) as poor responders. There were no significant best-corrected visual acuity and central retinal thickness differences at baseline (P = 0.176; P = 0.573, respectively). Ellipsoid zone disruption and disorganization of retinal inner layers were good predictors for treatment response, representing a significant risk for poor visual recovery to anti-vascular endothelial growth factor therapy (odds ratio = 10.96; P < 0.001 for ellipsoid zone disruption and odds ratio = 7.05; P = 0.034 for disorganization of retinal inner layers). Damage of ellipsoid zone, higher values of disorganization of retinal inner layers, and central retinal thickness decrease are good predictors of best-corrected visual acuity response to anti-vascular endothelial growth factor therapy.
NASA Astrophysics Data System (ADS)
Fu, Sen; Du, Jindan; Song, Yiwei; Gao, Tianyu; Zhang, Daqing; Wang, Yongzhi
2017-11-01
In space laser communication, optical antennas are one of the main components and the precision of optical antennas is very high. In this paper, it is based on the R-C telescope and it is carried out that the design and simulation of optical lens and supporting truss, according to the parameters of the systems. And a finite element method (FEM) was used to analyze the deformation of the optical lens. Finally, the Zernike polynomial was introduced to fit the primary mirror with a diameter of 250mm. The objective of this study is to determine whether the wave-front aberration of the primary mirror can meet the imaging quality. The results show that the deterioration of the imaging quality caused by the gravity deformation of primary and secondary mirrors. At the same time, the optical deviation of optical antenna increase with the diameter of the pupil.
Microfluidic point-of-care diagnostics for resource-poor environments
NASA Astrophysics Data System (ADS)
Laksanasopin, Tassaneewan; Chin, Curtis D.; Moore, Hannah; Wang, Jennifer; Cheung, Yuk Kee; Sia, Samuel K.
2009-05-01
Point-of-care (POC) diagnostics have tremendous potential to improve human health in remote and resource-poor settings. However, the design criteria for diagnostic tests appropriate in settings with limited infrastructure are unique and challenging. Here we present a custom optical reader which quantifies silver absorbance from heterogeneous immunoassays. The reader is simple and low-cost and suited for POC diagnostics.
Georges Sagnac: A life for optics
NASA Astrophysics Data System (ADS)
Darrigol, Olivier
2014-12-01
Georges Sagnac is mostly known for the optical effect in rotating frames that he demonstrated in 1913. His scientific interests were quite diverse: they included photography, optical illusions, X-ray physics, radioactivity, the blue of the sky, anomalous wave propagation, interferometry, strioscopy, and acoustics. An optical theme nonetheless pervaded his entire œuvre. Within optics, an original theory of the propagation of light motivated most of his investigations, from an ingenious explanation of the Fresnel drag, through the discovery of the Sagnac effect, to his quixotic defense of an alternative to relativity theory. Optical analogies efficiently guided his work in other domains. Optics indeed was his true passion. He saw himself as carrying the torch of the two great masters of French optics, Augustin Fresnel and Hippolyte Fizeau. In this mission he overcame his poor health and labored against the modernist tide, with much success originally and bitter isolation in the end. xml:lang="fr"
Separate and Joint Associations of Shift Work and Sleep Quality with Lipids.
Charles, Luenda E; Gu, Ja K; Tinney-Zara, Cathy A; Fekedulegn, Desta; Ma, Claudia C; Baughman, Penelope; Hartley, Tara A; Andrew, Michael E; Violanti, John M; Burchfiel, Cecil M
2016-06-01
Shift work and/or sleep quality may affect health. We investigated whether shift work and sleep quality, separately and jointly, were associated with abnormal levels of triglycerides, total cholesterol (TC), and low-and high-density lipoprotein cholesterol in 360 police officers (27.5% women). Triglycerides, TC, and high-density lipoprotein were analyzed on the Abbott Architect; low-density lipoprotein was calculated. Shift work was assessed using City of Buffalo payroll work history records. Sleep quality (good, ≤ 5; intermediate, 6-8; poor, ≥ 9) was assessed using the Pittsburgh Sleep Quality Index questionnaire. A shift work + sleep quality variable was created: day plus good sleep; day plus poor sleep; afternoon/night plus good; and poor sleep quality. Mean values of lipid biomarkers were compared across categories of the exposures using analysis of variance/analysis of covariance. Shift work was not significantly associated with lipids. However, as sleep quality worsened, mean levels of triglycerides and TC gradually increased but only among female officers (age- and race-adjusted p = 0.013 and 0.030, respectively). Age significantly modified the association between sleep quality and TC. Among officers ≥ 40 years old, those reporting poor sleep quality had a significantly higher mean level of TC (202.9 ± 3.7 mg/dL) compared with those reporting good sleep quality (190.6 ± 4.0 mg/dL) (gender- and race-adjusted p = 0.010). Female officers who worked the day shift and also reported good sleep quality had the lowest mean level of TC compared with women in the other three categories (p = 0.014). Sleep quality and its combined influence with shift work may play a role in the alteration of some lipid measures.
Loneliness and sleep quality: dyadic effects and stress effects.
Segrin, Chris; Burke, Tricia J
2015-01-01
The aims of this investigation are to determine whether loneliness is associated with a person's own sleep quality and sleep quality of their partner, and to test stress as a potential mediator. Participants were 255 couples in married (75%) or cohabiting relationships who completed self-report measures of loneliness, sleep quality, stress, and depression. Results of Actor-Partner Interdependence analyses replicated findings in the literature showing an association between loneliness and poor sleep quality. The more lonely a male participant was, the lower his partner's sleep quality. In addition, the more lonely participants were, the higher they rated their partner's sleep disturbance. There were significant indirect effects of loneliness on poor sleep quality through increased stress, even after controlling for depression.
Sleep Quality Improvement During Cognitive Behavioral Therapy for Anxiety Disorders.
Ramsawh, Holly J; Bomyea, Jessica; Stein, Murray B; Cissell, Shadha H; Lang, Ariel J
2016-01-01
Despite the ubiquity of sleep complaints among individuals with anxiety disorders, few prior studies have examined whether sleep quality improves during anxiety treatment. The current study examined pre- to posttreatment sleep quality improvement during cognitive behavioral therapy (CBT) for panic disorder (PD; n = 26) or generalized anxiety disorder (GAD; n = 24). Among sleep quality indices, only global sleep quality and sleep latency improved significantly (but modestly) during CBT. Sleep quality improvement was greater for treatment responders, but did not vary by diagnosis. Additionally, poor baseline sleep quality was independently associated with worse anxiety treatment outcome, as measured by higher intolerance of uncertainty. Additional intervention targeting sleep prior to or during CBT for anxiety may be beneficial for poor sleepers.
Management of source and drinking-water quality in Pakistan.
Aziz, J A
2005-01-01
Drinking-water quality in both urban and rural areas of Pakistan is not being managed properly. Results of various investigations provide evidence that most of the drinking-water supplies are faecally contaminated. At places groundwater quality is deteriorating due to the naturally occurring subsoil contaminants or to anthropogenic activities. The poor bacteriological quality of drinking-water has frequently resulted in high incidence of waterborne diseases while subsoil contaminants have caused other ailments to consumers. This paper presents a detailed review of drinking-water quality in the country and the consequent health impacts. It identifies various factors contributing to poor water quality and proposes key actions required to ensure safe drinking-water supplies to consumers.
NASA Astrophysics Data System (ADS)
Moon, Jiwon; Kim, Minbi; Lim, Jeong Sik; Kim, Joonghan
2018-06-01
Density functional theory (DFT) and time-dependent DFT calculations were performed to elucidate the electronic and optical properties of 2-R-naphthol[2,3-d]oxaphospholes (R-NOPs). On the basis of the calculated results, the poor π overlap between the 3pz orbital of P atom and the 2pz orbitals of other atoms and increasing polarity of P atom result in a reduced energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital. When these two effects are considered simultaneously, the absorption energies obtained for the S1 state can be below 3.00 eV according to replace the P atom of oxaphosphole ring by As atom (increasing the poor π overlap) and change the functional groups (increasing polarity). The origin of these two effects is the inherent size of the 3p orbital of P atom. The role of P atom in the control of the electronic and optical properties of R-NOPs is clearly elucidated.
Faria-Ribeiro, Miguel; Amorim-de-Sousa, Ana; González-Méijome, José M
2018-05-01
To investigate the separated and combined influences of inner zone (IZ) diameter and effective add power of dual-focus contact lenses (CL) in the image quality at distance and near viewing, in a functional accommodating model eye. Computational wave-optics methods were used to define zonal bifocal pupil functions, representing the optic zones of nine dual-focus centre-distance CLs. The dual-focus pupil functions were defined having IZ diameters of 2.10 mm, 3.36 mm and 4.00 mm, with add powers of 1.5 D, 2.0 D and 2.5 D (dioptres), for each design, that resulted in a ratio of 64%/36% between the distance and treatment zone areas, bounded by a 6 mm entrance pupil. A through-focus routine was implemented in MATLAB to simulate the changes in image quality, calculated from the Visual Strehl ratio, as the eye with the dual-focus accommodates, from 0 to -3.00 D target vergences. Accommodative responses were defined as the changes in the defocus coefficient, combined with a change in fourth and sixth order spherical aberration, which produced a peak in image quality at each target vergence. Distance viewing image quality was marginally affected by IZ diameter but not by add power. Near image quality obtained when focussing the image formed by the near optics was only higher by a small amount compared to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.28 ± 0.02, 0.23 ± 0.02 and 0.22 ± 0.02, for the small, medium and larger IZ diameters, respectively. On the other hand, near image quality predicted by focussing the image formed by the distance optics was considerably lower relatively to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.15 ± 0.01, 0.38 ± 0.00 and 0.54 ± 0.01, for the small, medium and larger IZ diameters, respectively. During near viewing through dual-focus CLs, image quality depends on the diameter of the most inner zone of the CL, while add power only affects the range of clear focus when focussing the image formed by the CL near optics. When only image quality gain is taken into consideration, medium and large IZ diameters designs are most likely to promote normal accommodative responses driven by the CL distance optics, while a smaller IZ diameter design is most likely to promote a reduced accommodative response driven by the dual-focus CL near optics. © 2018 The Authors Ophthalmic & Physiological Optics © 2018 The College of Optometrists.
Rayward, Anna T; Duncan, Mitch J; Brown, Wendy J; Plotnikoff, Ronald C; Burton, Nicola W
2017-08-01
This study aimed to identify how different patterns of physical activity, sleep duration and sleep quality cluster together, and to examine how the identified clusters differ in terms of socio-demographic and health characteristics. Participants were adults from Brisbane, Australia, aged 42-72 years who reported their physical activity, sleep duration, sleep quality, socio-demographic and health characteristics in 2011 (n=5854). Two-step Cluster Analyses were used to identify clusters. Cluster differences in socio-demographic and health characteristics were examined using chi square tests (p<0.05). Four clusters were identified: 'Poor Sleepers' (31.2%), 'Moderate Sleepers' (30.7%), 'Mixed Sleepers/Highly Active' (20.5%), and 'Excellent Sleepers/Mixed Activity' (17.6%). The 'Poor Sleepers' cluster had the highest proportion of participants with less-than-recommended sleep duration and poor sleep quality, had the poorest health characteristics and a high proportion of participants with low physical activity. Physical activity, sleep duration and sleep quality cluster together in distinct patterns and clusters of poor behaviours are associated with poor health status. Multiple health behaviour change interventions which target both physical activity and sleep should be prioritised to improve health outcomes in mid-aged adults. Copyright © 2017 Elsevier B.V. All rights reserved.
Diabetic nephropathy: a strong predictor of sleep quality in hemodialysis patients.
Edalat-Nejad, Mahnaz; Jafarian, Nahid; Yousefichaijan, Parsa
2014-07-01
Sleep complaints are common in hemodialysis (HD) patients. Sleep quality (SQ) is a predictor of quality of life and mortality risk in HD. The aim of this study was to examine factors that may have a role in SQ. In this cross-sectional analytic study, 138 end-stage renal disease patients receiving maintenance HD for >3 months were included. The Pittsburgh Sleep Quality Index (PSQI) was used to measure individual's SQ. Patients with a global PSQI score >5 were assumed as poor sleepers. Eighty-eight patients (64%) were classified as poor sleepers. Poor sleepers were older and more likely had diabetes. They had significantly higher serum ferritin and calcium levels and lower serum parathyroid hormone level (all P-values <0.05). The global PSQI score was positively correlated with age, serum calcium level and presence of diabetes as the underlying cause of renal failure. In the multi-variable binary regression model, presence of diabetes (Odds Ratio (OR) = 3.67, P = 0.008) and body pain (OR = 1.182, P = 0.014) were the significant independent predictors for poor SQ. Poor SQ was common among our HD patients, especially among diabetic cases and, therefore, there is a need to pay more attention to the care of this subgroup with regard to the diagnosis and management of sleep complaints.
NASA Astrophysics Data System (ADS)
Keene, Samuel T.; Cerussi, Albert E.; Warren, Robert V.; Hill, Brian; Roblyer, Darren; Leproux, AnaÑ--s.; Durkin, Amanda F.; O'Sullivan, Thomas D.; Haghany, Hosain; Mantulin, William W.; Tromberg, Bruce J.
2013-03-01
Instrument equivalence and quality control are critical elements of multi-center clinical trials. We currently have five identical Diffuse Optical Spectroscopic Imaging (DOSI) instruments enrolled in the American College of Radiology Imaging Network (ACRIN, #6691) trial located at five academic clinical research sites in the US. The goal of the study is to predict the response of breast tumors to neoadjuvant chemotherapy in 60 patients. In order to reliably compare DOSI measurements across different instruments, operators and sites, we must be confident that the data quality is comparable. We require objective and reliable methods for identifying, correcting, and rejecting low quality data. To achieve this goal, we developed and tested an automated quality control algorithm that rejects data points below the instrument noise floor, improves tissue optical property recovery, and outputs a detailed data quality report. Using a new protocol for obtaining dark-noise data, we applied the algorithm to ACRIN patient data and successfully improved the quality of recovered physiological data in some cases.
INDOOR AIR PURIFICATION VIA LOW-ENERGY, IN-SITU REGENERATED SILICA-TITANIA COMPOSITES - PHASE I
“Sick building syndrome,” used to describe acute negative health effects linked to time spent in a building, has been related to poor indoor air quality. Similarly, poor aircraft cabin air quality has been identified as a cause of negative health effects on pilots and fli...
Brown, G C; Shields, J A; Augsburger, J J; Serota, F T; Koch, P
1981-03-01
The clinical course and ophthalmic manifestations of an eight year old child with acute undifferentiated leukemia and unilateral blindness secondary to leukemic optic nerve head infiltration are described. At autopsy the involved nerve head and peripapillary retina demonstrated massive leukemic cell infiltration and hemorrhagic necrosis. This manifestation of leukemia is quite uncommon and prognosis for life in such cases is poor with existing methods of therapy.
HYPERSPECTRAL REMOTE SENSING OF WATER QUALITY PARAMETERS FOR LARGE RIVERS IN THE OHIO RIVER BASIN
Optical indicators of water quality have the potential of enhancing the abilities of resource managers to monitor water bodies in a timely and cost-effective manner. However, the degree to which optical indicators are useful may depend on their applicability to data collected fr...
Wilbanks, Bryan A; Geisz-Everson, Marjorie; Boust, Rebecca R
2016-09-01
Clinical documentation is a critical tool in supporting care provided to patients. Sound documentation provides a picture of clinical events that can be used to improve patient care. However, many other uses for clinical documentation are equally important. Such documentation informs clinical decision support tools, creates a legal record of patient care, assists in financial reimbursement of services, and serves as a repository for secondary data analysis. Conversely, poor documentation can impair patient safety and increase malpractice risk exposure by reflecting poor or inaccurate information that ultimately may guide patient care decisions.Through an examination of anesthesia-related closed claims, a descriptive qualitative study emerged, which explored the antecedents and consequences of documentation quality in the claims reviewed. A secondary data analysis utilized a database generated by the American Association of Nurse Anesthetists Foundation closed claim review team. Four major themes emerged from the analysis. Themes 1, 2, and 4 primarily describe how poor documentation quality can have negative consequences for clinicians. The third theme primarily describes how poor documentation quality that can negatively affect patient safety.
Van Veen, M M; Karsten, J; Lancel, M
2017-01-01
Studies investigating sleep and personality disorders consistently demonstrate a relation between personality disorders characterized by behavioral disinhibition and/or emotional dysregulation (traditionally termed cluster B personality disorders) and poor sleep. This finding is in line with previous studies associating insomnia with impulsive behavior, since this is a core characteristic of both antisocial and borderline personality disorder. The current study investigates a group (n = 112) of forensic psychiatric inpatients with antisocial or borderline personality disorder or traits thereof. Subjective sleep characteristics and impulsivity were assessed with the Pittsburgh Sleep Quality Index, the Sleep Diagnosis List, and the Barratt Impulsiveness Scale, respectively. More than half of the patients (53.6%) report poor sleep quality and 22.3% appears to suffer from severe chronic insomnia. Both poor sleep quality and chronic insomnia are significantly associated with self-reported impulsivity, in particular with attentional impulsiveness. This association was not significantly influenced by comorbid disorders. Actively treating sleep problems in these patients may not only improve sleep quality, mental health, and physical well-being, but may also have impact on impulsivity-related health risks by increasing self-control.
Deoxyribonucleic acid (DNA)-based optical materials
NASA Astrophysics Data System (ADS)
Grote, James G.; Heckman, Emily M.; Hagen, Joshua A.; Yaney, Perry P.; Subramanyam, Guru; Clarson, Stephen J.; Diggs, Darnell E.; Nelson, Robert L.; Zetts, John S.; Hopkins, F. Kenneth; Ogata, Naoya
2004-12-01
Optical materials for waveguiding applications must possess the desired optical and electromagnetic properties for optimal device performance. Purified deoxyribonucleic acid (DNA), derived from salmon sperm, has been investigated for use as an optical waveguide material. In this paper we present the materials processing and optical and electromagnetic characterization of this purified DNA to render a high quality, low loss optical waveguide material.
Quality of Sleep and its Relationship to Quality of Life in Hemodialysis Patients
Parvan, Kobra; lakdizaji, Sima; Roshangar, Fariborz; Mostofi, Mahtab
2013-01-01
Introduction: Despite many advances in the treatment of chronic renal failure, the quality of sleep in patients who suffer from this disease is at the risk. The high prevalence of sleep disorders in hemodialysis patients, which is concomitant with physical, behavioral, and psychological problems, has always affected these patients' quality of life (QOL). This study aimed to determine the relationship between quality of sleep and quality of life in hemodialysis patients. Methods: By using a descriptive and correlational design, this study was conducted on 245 hemodialysis patients in 2012. Patients were selected by convenience sampling from the hemodialysis ward of four training hospitals of Tabriz and Maragheh. Quality of sleep was measured by the Pittsburgh Sleep Quality Index (PSQI), and the quality of life for patients was measured by the Kidney Disease Quality Of Life questionnaire (KDQOL-SF). Results: 83.3% of hemodialysis patients had poor quality of sleep. Poor quality of life was significantly associated with poor quality of sleep. There was a significant negative correlation between global PSQI and important aspects of quality of life including physical health, symptoms and problems, the impact of kidney disease on daily life, burden of kidney disease, mental health, social support, and sexual function. Conclusion: The low quality of sleep in hemodialysis patients has an effect on the deterioration of their quality of life. Therefore, training, counseling, and advocacy programs should be developed to improve the patients' quality of sleep and quality of life, especially those with lower education level and income, and older people. PMID:25276738
Sleep quality and quality of life in female shift-working nurses.
Shao, Ming-Fen; Chou, Yu-Ching; Yeh, Mei-Yu; Tzeng, Wen-Chii
2010-07-01
This paper is a report of a study of the factors that influence sleep quality and quality of life among shift-working nurses and the relationship between their sleep quality and quality of life. Although shift-working nurses strive to adapt their life schedules to shift rotations, they tend to suffer from severe sleep disturbances and increased rates of cancer, cardiovascular diseases, digestive disease and irregular menstrual cycles. Poor sleep is also associated with medical errors and occupational injuries. A cross-sectional study was conducted in 2008 with a convenience sample of 435 female nurses from five regional hospitals in Taiwan. Data were collected on sleep quality and quality of life using the Pittsburgh Sleep Quality Index and World Health Organization Quality of Life Instrument-BREF Taiwan version respectively. Data were analysed using descriptive statistics, independent t-tests, analysis of variance and Pearson correlations. The majority of female shift workers (57%) had global sleep-quality scores > or = 5, indicating poor sleep and all mean scores in four domains of the quality-of-life measure were statistically significantly lower than those of females in Taiwan's general population. Scores for poor sleep quality and quality of life were related to premenstrual dysphoria, occupational injury, illness and medication use. In addition, the associations between scores on the sleep-quality and quality-of-life scales were statistically significantly inversely correlated. Advice should be included in both undergraduate programmes and continuing education to help nurses to recognize and improve their own sleep quality and life quality managers should create a supportive environment to encourage shift-working nurses to engage in healthy behaviours.
Assessment of physical and mental health in male university students with varying sleep habits.
Matsumoto, Yuuki; Toyomasu, Kouji; Uchimura, Naohisa
2011-01-01
Healthy sleep habits entail not only sleeping for a sufficient period (quantity) but also regularity of the sleep cycle and getting sound sleep (quality). University students often have erratic schedules that cause irregular sleep patterns even though sleep durations remain relatively constant. This study compared the physical and mental health of 90 male university students with different sleep habits. We created sleep habit scales using the Tokyo Metropolitan Institute for Neuroscience life habits inventory (TMIN-LHI; Miyashita, 1994) by performing a factor analysis and classifying sleeping habits based on regularity, quality, and quantity. Four types of sleep habits were identified by cluster analysis; good sleep was characterized by regular and high quality sleep but of relatively short sleep duration; long sleep was regular and relatively long but of low quality; short sleep was of high quality but short and irregular, while poor sleep was irregular, of low quality, and relatively long. The good sleep group had a significantly lower average waist circumference, and lower systolic and diastolic blood pressure. The long and poor sleep groups, which both had low quality sleep, scored lower than the national standard on the mental component summary (MCS) calculated from the Social Functioning-36 (SF-36) short-form health survey. Furthermore, the average MCS score of the poor sleep group was significantly lower than that of any other sleep habit group. Subjects with poor sleep also scored lowest on the Self-rating Depression Scale (SDS). In addition, the short and poor sleep groups were prone to glucose or lipid metabolism disorders. Maintaining good physical and mental health without sound sleep and a regular sleep cycle is difficult, even if sleeping hours are kept constant. Therefore, we included the assessment of regularity and quality in addition to hours of sleep in order to develop appropriate sleep guidelines for improved physical and mental health.
Chandola, Tarani; Zhang, Nan
2018-01-01
Abstract Background There is little evidence on whether becoming re-employed in poor quality work is better for health and well-being than remaining unemployed. We examined associations of job transition with health and chronic stress-related biomarkers among a population-representative cohort of unemployed British adults. Methods A prospective cohort of 1116 eligible participants aged 35 to 75 years, who were unemployed at wave 1 (2009/10) of the UK Household Longitudinal Study, were followed up at waves 2 (2010/11) and 3 (2011/12) for allostatic load biomarkers and self-reported health. Negative binomial and multiple regression models estimated the association between job adversity and these outcomes. Results Compared with adults who remained unemployed, formerly unemployed adults who transitioned into poor quality jobs had higher levels of overall allostatic load (0.51, 0.32–0.71), log HbA1c (0.06, <0.001–0.12), log triglycerides (0.39, 0.22–0.56), log C-reactive protein (0.45, 0.16–0.75), log fibrinogen (0.09, 0.01–0.17) and total cholesterol to high-density lipoprotein (HDL) ratio (1.38, 0.88–1.88). Moreover, physically healthier respondents at wave 1 were more likely to transition into good quality and poor quality jobs after 1 year than those who remained unemployed. Conclusions Formerly unemployed adults who transitioned into poor quality work had greater adverse levels of biomarkers compared with their peers who remained unemployed. The selection of healthier unemployed adults into these poor quality or stressful jobs was unlikely to explain their elevated levels of chronic stress-related biomarkers. Job quality cannot be disregarded from the employment success of the unemployed, and may have important implications for their health and well-being. PMID:29024973
Roalf, David R.; Quarmley, Megan; Elliott, Mark A.; Satterthwaite, Theodore D.; Vandekar, Simon N.; Ruparel, Kosha; Gennatas, Efstathios D.; Calkins, Monica E.; Moore, Tyler M.; Hopson, Ryan; Prabhakaran, Karthik; Jackson, Chad T.; Verma, Ragini; Hakonarson, Hakon; Gur, Ruben C.; Gur, Raquel E.
2015-01-01
Background Diffusion tensor imaging (DTI) is applied in investigation of brain biomarkers for neurodevelopmental and neurodegenerative disorders. However, the quality of DTI measurements, like other neuroimaging techniques, is susceptible to several confounding factors (e.g. motion, eddy currents), which have only recently come under scrutiny. These confounds are especially relevant in adolescent samples where data quality may be compromised in ways that confound interpretation of maturation parameters. The current study aims to leverage DTI data from the Philadelphia Neurodevelopmental Cohort (PNC), a sample of 1,601 youths ages of 8–21 who underwent neuroimaging, to: 1) establish quality assurance (QA) metrics for the automatic identification of poor DTI image quality; 2) examine the performance of these QA measures in an external validation sample; 3) document the influence of data quality on developmental patterns of typical DTI metrics. Methods All diffusion-weighted images were acquired on the same scanner. Visual QA was performed on all subjects completing DTI; images were manually categorized as Poor, Good, or Excellent. Four image quality metrics were automatically computed and used to predict manual QA status: Mean voxel intensity outlier count (MEANVOX), Maximum voxel intensity outlier count (MAXVOX), mean relative motion (MOTION) and temporal signal-to-noise ratio (TSNR). Classification accuracy for each metric was calculated as the area under the receiver-operating characteristic curve (AUC). A threshold was generated for each measure that best differentiated visual QA status and applied in a validation sample. The effects of data quality on sensitivity to expected age effects in this developmental sample were then investigated using the traditional MRI diffusion metrics: fractional anisotropy (FA) and mean diffusivity (MD). Finally, our method of QA is compared to DTIPrep. Results TSNR (AUC=0.94) best differentiated Poor data from Good and Excellent data. MAXVOX (AUC=0.88) best differentiated Good from Excellent DTI data. At the optimal threshold, 88% of Poor data and 91% Good/Excellent data were correctly identified. Use of these thresholds on a validation dataset (n=374) indicated high accuracy. In the validation sample 83% of Poor data and 94% of Excellent data was identified using thresholds derived from the training sample. Both FA and MD were affected by the inclusion of poor data in an analysis of age, sex and race in a matched comparison sample. In addition, we show that the inclusion of poor data results in significant attenuation of the correlation between diffusion metrics (FA and MD) and age during a critical neurodevelopmental period. We find higher correspondence between our QA method and DTIPrep for Poor data, but we find our method to be more robust for apparently high-quality images. Conclusion Automated QA of DTI can facilitate large-scale, high-throughput quality assurance by reliably identifying both scanner and subject induced imaging artifacts. The results present a practical example of the confounding effects of artifacts on DTI analysis in a large population-based sample, and suggest that estimates of data quality should not only be reported but also accounted for in data analysis, especially in studies of development. PMID:26520775
Gerhart, James I; Burns, John W; Post, Kristina M; Smith, David A; Porter, Laura S; Burgess, Helen J; Schuster, Erik; Buvanendran, Asokumar; Fras, Anne Marie; Keefe, Francis J
2017-06-01
Poor sleep quality among people with chronic low back pain appears to be related to worse pain, affect, poor physical function, and pain catastrophizing. The causal direction between poor sleep and pain remains an open question, however, as does whether sleep quality exerts effects on low back pain differently across the course of the day. This daily diary study examined lagged temporal associations between prior night sleep quality and subsequent day pain, affect, physical function and pain catastrophizing, the reverse lagged temporal associations between prior day pain-related factors and subsequent night sleep quality, and whether the time of day during which an assessment was made moderated these temporal associations. Chronic low back pain patients (n = 105) completed structured electronic diary assessments five times per day for 14 days. Items included patient ratings of their pain, affect, physical function, and pain catastrophizing. Collapsed across all observations, poorer sleep quality was significantly related to higher pain ratings, higher negative affect, lower positive affect, poorer physical function, and higher pain catastrophizing. Lagged analyses averaged across the day revealed that poorer prior night sleep quality significantly predicted greater next day patient ratings of pain, and poorer physical function and higher pain catastrophizing. Prior poorer night sleep quality significantly predicted greater reports of pain, and poorer physical function, and higher pain catastrophizing, especially during the early part of the day. Sleep quality × time of day interactions showed that poor sleepers reported high pain, and negative mood and low function uniformly across the day, whereas good sleepers reported relatively good mornings, but showed pain, affect and function levels comparable to poor sleepers by the end of the day. Analyses of the reverse causal pathway were mostly nonsignificant. Sleep quality appears related not only to pain intensity but also to a wide range of patient mood and function factors. A good night's sleep also appears to offer only temporary respite, suggesting that comprehensive interventions for chronic low back pain not only should include attention to sleep problems but also focus on problems with pain appraisals and coping.
Li, Pengsheng; Huang, Yeen; Guo, Lan; Wang, Wanxin; Xi, Chuhao; Lei, Yiling; Luo, Min; Pan, Siyuan; Deng, Xueqing; Zhang, Wei-hong; Lu, Ciyong
2017-01-01
Objectives Recent studies have suggested that sexual minorities are more likely to have poor sleep quality. This study aims to explore sleep quality among sexual minority adolescents and examines the association between sexual minority status and sleep quality. Design Cross-sectional survey. Setting A total of 506 high schools in seven Chinese provinces. Participants A total of 150 822 students in grades 7–12 completed the questionnaires, and 123 459 students who reported being aware of their sexual orientation were included in analyses. Main outcome measures The Pittsburgh Sleep Quality Index, sexual attraction and school bullying victimisation. Results Of the 123 459 students who were analysed, 5.00% self-reported as sexual minorities. Only 26.67% of sexual minority students slept 8 or more hours/day, which is less than their heterosexual peers (35.70%; χ2=130.04, P<0.001). Of the total sample, 22.41% of the students reported poor sleep quality, and this prevalence was significantly higher in sexual minority students than in heterosexual students (32.56% vs 21.87%; χ2=281.70, P<0.001). After controlling for social demographics, lifestyle and depressive symptoms, sexual minority students had higher odds of poor sleep quality (adjusted OR=1.41, 95% CI 1.31 to 1.51) than their heterosexual peers. The indirect effect of school bullying victimisation (standardised β estimate=0.007, 95% CI 0.006 to 0.009) was significant, indicating that school bullying victimisation partially mediated the association between sexual minority status and sleep quality. Conclusions Our study suggested that poor sleep quality was common in sexual minority adolescents, and more attention should be paid to sleep problems in this population. Conducting interventions to reduce school bullying behaviours is an important step to improving sleep quality in sexual minority adolescents. Further, studies are warranted that focus on the risk factors and mechanisms of and interventions for sleep problems in sexual minority adolescents. PMID:29282258
Gerhart, James I.; Burns, John W.; Post, Kristina M.; Smith, David A.; Porter, Laura S.; Burgess, Helen J.; Schuster, Erik; Buvanendran, Asokumar; Fras, Anne Marie; Keefe, Francis J.
2016-01-01
Background Poor sleep quality among people with chronic low back pain appears to be related to worse pain, affect, poor physical function and pain catastrophizing. The causal direction between poor sleep and pain remains an open question, however, as does whether sleep quality exerts effects on low back pain differently across the course of the day. Purpose This daily diary study examined lagged temporal associations between prior night sleep quality and subsequent day pain, affect, physical function and pain catastrophizing, the reverse lagged temporal associations between prior day pain-related factors and subsequent night sleep quality, and whether the time of day during which an assessment was made moderated these temporal associations. Methods Chronic low back pain patients (n = 105) completed structured electronic diary assessments five times per day for 14 days. Items included patient ratings of their pain, affect, physical function and pain catastrophizing. Results Collapsed across all observations, poorer sleep quality was significantly related to higher pain ratings, higher negative affect, lower positive affect, poorer physical function and higher pain catastrophizing. Lagged analyses averaged across the day revealed that poorer prior night sleep quality significantly predicted greater next day patient ratings of pain, and poorer physical function and higher pain catastrophizing. Prior poorer night sleep quality significantly predicted greater reports of pain, and poorer physical function, and higher pain catastrophizing, especially during the early part of the day. Sleep Quality × Time of Day interactions showed that poor sleepers reported high pain, and negative mood and low function uniformly across the day, whereas good sleepers reported relatively good mornings, but showed pain, affect and function levels comparable to poor sleepers by the end of the day. Analyses of the reverse causal pathway were mostly nonsignificant. Conclusions Sleep quality appears related not only to pain intensity but also to a wide range of patient mood and function factors. A good night’s sleep also appears to offer only temporary respite, suggesting that comprehensive interventions for chronic low back pain not only should include attention to sleep problems but also focus on problems with pain appraisals and coping. PMID:27844327
NASA Technical Reports Server (NTRS)
Decker, A. J.; Stricker, J.
1985-01-01
Electronic heterodyne moire deflectometry and electronic heterodyne holographic interferometry are compared as methods for the accurate measurement of refractive index and density change distributions of phase objects. Experimental results are presented to show that the two methods have comparable accuracy for measuring the first derivative of the interferometric fringe shift. The phase object for the measurements is a large crystal of KD*P, whose refractive index distribution can be changed accurately and repeatably for the comparison. Although the refractive index change causes only about one interferometric fringe shift over the entire crystal, the derivative shows considerable detail for the comparison. As electronic phase measurement methods, both methods are very accurate and are intrinsically compatible with computer controlled readout and data processing. Heterodyne moire is relatively inexpensive and has high variable sensitivity. Heterodyne holographic interferometry is better developed, and can be used with poor quality optical access to the experiment.
Femtosecond laser micromachining of compound parabolic concentrator fiber tipped glucose sensors.
Hassan, Hafeez Ul; Lacraz, Amédée; Kalli, Kyriacos; Bang, Ole
2017-03-01
We report on highly accurate femtosecond (fs) laser micromachining of a compound parabolic concentrator (CPC) fiber tip on a polymer optical fiber (POF). The accuracy is reflected in an unprecedented correspondence between the numerically predicted and experimentally found improvement in fluorescence pickup efficiency of a Förster resonance energy transfer-based POF glucose sensor. A Zemax model of the CPC-tipped sensor predicts an optimal improvement of a factor of 3.96 compared to the sensor with a plane-cut fiber tip. The fs laser micromachined CPC tip showed an increase of a factor of 3.5, which is only 11.6% from the predicted value. Earlier state-of-the-art fabrication of the CPC-shaped tip by fiber tapering was of so poor quality that the actual improvement was 43% lower than the predicted improvement of the ideal CPC shape.
Femtosecond laser micromachining of compound parabolic concentrator fiber tipped glucose sensors
NASA Astrophysics Data System (ADS)
Hassan, Hafeez Ul; Lacraz, Amédée; Kalli, Kyriacos; Bang, Ole
2017-03-01
We report on highly accurate femtosecond (fs) laser micromachining of a compound parabolic concentrator (CPC) fiber tip on a polymer optical fiber (POF). The accuracy is reflected in an unprecedented correspondence between the numerically predicted and experimentally found improvement in fluorescence pickup efficiency of a Förster resonance energy transfer-based POF glucose sensor. A Zemax model of the CPC-tipped sensor predicts an optimal improvement of a factor of 3.96 compared to the sensor with a plane-cut fiber tip. The fs laser micromachined CPC tip showed an increase of a factor of 3.5, which is only 11.6% from the predicted value. Earlier state-of-the-art fabrication of the CPC-shaped tip by fiber tapering was of so poor quality that the actual improvement was 43% lower than the predicted improvement of the ideal CPC shape.
Scattering Removal for Finger-Vein Image Restoration
Yang, Jinfeng; Zhang, Ben; Shi, Yihua
2012-01-01
Finger-vein recognition has received increased attention recently. However, the finger-vein images are always captured in poor quality. This certainly makes finger-vein feature representation unreliable, and further impairs the accuracy of finger-vein recognition. In this paper, we first give an analysis of the intrinsic factors causing finger-vein image degradation, and then propose a simple but effective image restoration method based on scattering removal. To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues. Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration. Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy. PMID:22737028
Racial residential segregation and preterm birth: built environment as a mediator.
Anthopolos, Rebecca; Kaufman, Jay S; Messer, Lynne C; Miranda, Marie Lynn
2014-05-01
Racial residential segregation has been associated with preterm birth. Few studies have examined mediating pathways, in part because, with binary outcomes, indirect effects estimated from multiplicative models generally lack causal interpretation. We develop a method to estimate additive-scale natural direct and indirect effects from logistic regression. We then evaluate whether segregation operates through poor-quality built environment to affect preterm birth. To estimate natural direct and indirect effects, we derive risk differences from logistic regression coefficients. Birth records (2000-2008) for Durham, North Carolina, were linked to neighborhood-level measures of racial isolation and a composite construct of poor-quality built environment. We decomposed the total effect of racial isolation on preterm birth into direct and indirect effects. The adjusted total effect of an interquartile increase in racial isolation on preterm birth was an extra 27 preterm events per 1000 births (risk difference = 0.027 [95% confidence interval = 0.007 to 0.047]). With poor-quality built environment held at the level it would take under isolation at the 25th percentile, the direct effect of an interquartile increase in isolation was 0.022 (-0.001 to 0.042). Poor-quality built environment accounted for 35% (11% to 65%) of the total effect. Our methodology facilitates the estimation of additive-scale natural effects with binary outcomes. In this study, the total effect of racial segregation on preterm birth was partially mediated by poor-quality built environment.
Silva, Andressa; Queiroz, Sandra Souza; Winckler, Ciro; Vital, Roberto; Sousa, Ronnie Andrade; Fagundes, Vander; Tufik, Sergio; de Mello, Marco Túlio
2012-02-01
The objective of this study was to evaluate the sleep quality, sleepiness, chronotype and the anxiety level of Brazilian Paralympics athletes before the 2008 Beijing Paralympic Games. Cross-sectional study. Setting Exercise and Psychobiology Studies Center (CEPE) and Universidade Federal de São Paulo, an urban city in Brazil. A total of 27 Paralympics athletes of both genders (16 men and 11 women) with an average age of 28±6 years who practised athletics (track and field events) were evaluated. Sleep quality was evaluated using the Pittsburgh Scale and the Epworth Sleepiness Scale to evaluate sleepiness. Chronotype was determined by the Horne and Östberg questionnaire and anxiety through the State-Trait Anxiety Inventory. The evaluations were performed in Brazil 10 days before the competition. The study's results demonstrate that 83.3% of the athletes that presented excessive daytime sleepiness also had poor sleep quality. The authors noted that 71.4% were classified into the morning type and 72% of the athletes who presented a medium anxiety level also presented poor sleep quality. Athletes with poor sleep quality showed significantly lower sleep efficiency (p=0.0119) and greater sleep latency (p=0.0068) than athletes with good sleep quality. Athletes who presented excessive daytime sleepiness presented lower sleep efficiency compared to non-sleepy athletes (p=0.0241). The authors conclude that the majority of athletes presented poor sleep quality before the competition. This information should be taken into consideration whenever possible when scheduling rest, training and competition times.
Wright, Regina S; Waldstein, Shari R; Kuczmarski, Marie Fanelli; Pohlig, Ryan T; Gerassimakis, Constance S; Gaynor, Beatrice; Evans, Michele K; Zonderman, Alan B
2017-01-01
Poor diet quality contributes to morbidity, including poor brain health outcomes such as cognitive decline and dementia. African Americans and individuals living in poverty may be at greater risk for cognitive decrements from poor diet quality. Cross-sectional. Baltimore, MD, USA. Participants were 2090 African Americans and Whites (57 % female, mean age=47·9 years) who completed two 24 h dietary recalls. We examined cognitive performance and potential interactions of diet quality with race and poverty status using baseline data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Healthy Eating Index-2010 (HEI-2010) scores were calculated and interpreted using federal guidelines. A neurocognitive test battery was administered to evaluate cognitive function over several domains. Linear regression analyses showed that lower HEI-2010 scores were associated with poorer verbal learning and memory (P<0·05) after adjustment for covariates. Diet quality within the sample was poor. Significant interactions of HEI-2010 and poverty status (all P<0·05) indicated that higher diet quality was associated with higher performance on tests of attention and cognitive flexibility, visuospatial ability and perceptual speed among those below the poverty line. No significant race interactions emerged. Higher diet quality was associated with better performance on two measures of verbal learning and memory, irrespective of race and poverty status. Findings suggest that diet quality and cognitive function are likely related at the population level. Future research is needed to determine whether the association is clinically significant.
Electro-optics laboratory evaluation: Deutsch optical waveguide connectors
NASA Technical Reports Server (NTRS)
1980-01-01
A description of a test program evaluating the performance of an optical waveguide connector system is presented. Both quality and effectiveness of connections made in an optical fiber, performance of the equipment used and applicability of equipment and components to field conditions are reviewed.
Li, Heng; Zhang, Lei; Yang, Zhengfei; Huang, Zitong; Chen, Bihua; Li, Yongqin; Yu, Tao
2013-01-01
Objective. Untrained bystanders usually delivered suboptimal chest compression to victims who suffered from cardiac arrest in out-of-hospital settings. We therefore investigated the hemodynamics and resuscitation outcome of initial suboptimal quality of chest compressions compared to the optimal ones in a porcine model of cardiac arrest. Methods. Fourteen Yorkshire pigs weighted 30 ± 2 kg were randomized into good and poor cardiopulmonary resuscitation (CPR) groups. Ventricular fibrillation was electrically induced and untreated for 6 mins. In good CPR group, animals received high quality manual chest compressions according to the Guidelines (25% of animal's anterior-posterior thoracic diameter) during first two minutes of CPR compared with poor (70% of the optimal depth) compressions. After that, a 120-J biphasic shock was delivered. If the animal did not acquire return of spontaneous circulation, another 2 mins of CPR and shock followed. Four minutes later, both groups received optimal CPR until total 10 mins of CPR has been finished. Results. All seven animals in good CPR group were resuscitated compared with only two in poor CPR group (P < 0.05). The delayed optimal compressions which followed 4 mins of suboptimal compressions failed to increase the lower coronary perfusion pressure of five non-survival animals in poor CPR group. Conclusions. In a porcine model of prolonged cardiac arrest, even four minutes of initial poor quality of CPR compromises the hemodynamics and survival outcome. PMID:24364028
Jian, Yifan; Xu, Jing; Gradowski, Martin A.; Bonora, Stefano; Zawadzki, Robert J.; Sarunic, Marinko V.
2014-01-01
We present wavefront sensorless adaptive optics (WSAO) Fourier domain optical coherence tomography (FD-OCT) for in vivo small animal retinal imaging. WSAO is attractive especially for mouse retinal imaging because it simplifies optical design and eliminates the need for wavefront sensing, which is difficult in the small animal eye. GPU accelerated processing of the OCT data permitted real-time extraction of image quality metrics (intensity) for arbitrarily selected retinal layers to be optimized. Modal control of a commercially available segmented deformable mirror (IrisAO Inc.) provided rapid convergence using a sequential search algorithm. Image quality improvements with WSAO OCT are presented for both pigmented and albino mouse retinal data, acquired in vivo. PMID:24575347
Overview of microoptics: Past, present, and future
NASA Technical Reports Server (NTRS)
Veldkamp, Wilfrid B.
1993-01-01
Through advances in semiconductor miniaturization technology, microrelief patterns, with characteristic dimensions as small as the wavelength of light, can now be mass reproduced to form high-quality and low-cost optical components. In a unique example of technology transfer, from electronics to optics, this capability is allowing optics designers to create innovative optical components that promise to solve key problems in optical sensors, optical communication channels, and optical processors.
Analysis and modeling of atmospheric turbulence on the high-resolution space optical systems
NASA Astrophysics Data System (ADS)
Lili, Jiang; Chen, Xiaomei; Ni, Guoqiang
2016-09-01
Modeling and simulation of optical remote sensing system plays an unslightable role in remote sensing mission predictions, imaging system design, image quality assessment. It has already become a hot research topic at home and abroad. Atmospheric turbulence influence on optical systems is attached more and more importance to as technologies of remote sensing are developed. In order to study the influence of atmospheric turbulence on earth observation system, the atmospheric structure parameter was calculated by using the weak atmospheric turbulence model; and the relationship of the atmospheric coherence length and high resolution remote sensing optical system was established; then the influence of atmospheric turbulence on the coefficient r0h of optical remote sensing system of ground resolution was derived; finally different orbit height of high resolution optical system imaging quality affected by atmospheric turbulence was analyzed. Results show that the influence of atmospheric turbulence on the high resolution remote sensing optical system, the resolution of which has reached sub meter level meter or even the 0.5m, 0.35m and even 0.15m ultra in recent years, image quality will be quite serious. In the above situation, the influence of the atmospheric turbulence must be corrected. Simulation algorithms of PSF are presented based on the above results. Experiment and analytical results are posted.
Comparison of Dietary Quality Among Puerto Ricans Living in Massachusetts and Puerto Rico.
Lopez-Cepero, Andrea; Valencia, Alexandra; Jimenez, Julio; Lemon, Stephenie C; Palacios, Cristina; Rosal, Milagros C
2017-04-01
Puerto Ricans are burdened by nutrition-related diseases, with greater disease prevalence among Puerto Ricans residing in the continental U.S. compared to those in Puerto Rico (PR). However, little is known about diet quality of these two groups. To compare diet quality of Puerto Ricans in Massachusetts (MA) and PR. Puerto Rican patients from health centers in MA (n = 42) and PR (n = 52) completed a food frequency questionnaire. Diet quality was assessed with the Healthy Eating Index-2010 (HEI). Analysis included Mann-Whitney, Chi square and logistic and quantile regressions. 57.1 % of participants in MA and 19.6 % in PR had a poor diet. Adjusting for age and education, participants in MA were more likely to have a poor diet (OR 3.4; p = 0.02) and lower HEI scores than participants in PR. Diet quality among Puerto Ricans is poor, and is worse among mainland Puerto Ricans compared to islanders.
Dumpster Optics: teaching and learning optics without a kit
NASA Astrophysics Data System (ADS)
Donnelly, Judy; Magnani, Nancy; Robinson, Kathleen
2016-09-01
The Next Generation Science Standards (NGSS) and renewed emphasis on STEM education in the U.S. have resulted in the development of many educational kits for teaching science in general and optics in particular. Many teachers do not have funding to purchase kits and practical experience has shown that even costly kits can have poorly written and misleading instructions and may include experiments that would not work in a classroom. Dumpster Optics lessons are designed to use inexpensive, commonly found materials. All lessons have been field-tested with students. We will describe the development of the lessons, provide examples of field testing experiences and outline possible future activities.
Using the Cross-Correlation Function to Evaluate the Quality of Eddy-Covariance Data
NASA Astrophysics Data System (ADS)
Qi, Yongfeng; Shang, Xiaodong; Chen, Guiying; Gao, Zhiqiu; Bi, Xueyan
2015-11-01
A cross-correlation test is proposed for evaluating the quality of 30-min eddy-covariance data. Cross-correlation as a function of time lag is computed for vertical velocity paired with temperature, humidity, and carbon dioxide concentration. High quality data have a dominant peak at zero time lag and approach zero within a time lag of 20 s. Poor quality data have erratic cross-correlation functions, which indicates that the eddy flux may no longer represent the energy and mass exchange between the atmospheric surface layer and the canopy, and such data should be rejected in post-data analyses. Eddy-covariance data over grassland in July 2004 are used to evaluate the proposed test. The results show that 17, 29, and 36 % of the available data should be rejected because of poor quality measurements of sensible heat, latent heat, and CO2 fluxes, respectively. The rejected data mainly occurred on calm nights and day/night transitions when the atmospheric surface layer became stable or neutrally stratified. We found no friction velocity (u_*) threshold below which all data should be rejected, a test that many other studies have implemented for rejecting questionable data. We instead found that some data with low u_* were reliable, whereas other data with higher u_* were not. The poor quality measurements collected under less than ideal conditions were replaced by using the mean diurnal variation gap-filling method. The correction for poor quality data shifted the daily average CO2 flux by +0.34 g C m^{-2} day^{-1}. After applying the quality-control test, the eddy CO2 fluxes did not display a clear dependence on u_*. The results suggest that the cross-correlation test is a potentially valuable step in evaluating the quality of eddy-covariance data.
Sleep Quality in Medical Students; the Impact of Over-Use of Mobile Cell-Phone and Social Networks.
Mohammadbeigi, Abolfazl; Absari, Rozita; Valizadeh, Farzaneh; Saadati, Mohammadreza; Sharifimoghadam, Soroush; Ahmadi, Ali; Mokhtari, Mohsen; Ansari, Hossein
2016-01-01
Poor sleep quality is closely associated with lifestyle habits including use of mobile cell-phones.This study aimed to identify the relationship between sleep quality due to abuse in mobile cell-phones and engagement in social networks. This cross-sectional study was conducted on 380 undergraduate students selected by proportional stratified sampling in Qom, Iran in 2015. Data were collected by two standard questionnaire including Cell-Phone Over-Use Scale (COS) and Pittsburgh sleep quality questionnaire beside the status of usage in cell-phone social networks. T-test, chi-square, Pearson correlation coefficient and multivariate logistic regression were used in data analysis. The mean age of participants was 21.8 ±3.2 yr, 69.1% were female, and 11.7% were married. The mean of COS and sleep quality scores were 48.18 ±17.5 and 5.38 ±2.31, respectively. The prevalence of over-use of cell phone was 10.7% (CI 0.95; 8.8%, 12.6%) and the prevalence of poor sleep quality was 61.7% (CI 0.95; 57.1%, 66.3%). The mean of all aspects and total score of sleep quality showed a direct significant association by cell-phone addiction score except sleep duration score that was inversely. Based on multivariate analysis affected to cell-phone addiction, being male gender and studying in general physician level are the most important predictors of poor sleep quality. Over use of internet and social networks via smart phones is related to poor sleep quality and quantity. Predefined sport programs, educational, cultural, and interesting entertainment are the essential needs for all medical students. These interventions are more important especially for male students who have longer educational.
Super-light-weighted HB-Cesic® mirror cryogenic test
NASA Astrophysics Data System (ADS)
Devilliers, Christophe; Krödel, Matthias R.; Sodnik, Zoran; Robert, Patrick
2017-11-01
Future scientific space missions require ever more demanding large optics that work at cryogenic temperatures. In the frame of a Darwin assessment study conducted under ESA contract by TAS, the need of future very lightweight cryogenic mirrors with superior optical quality has been identified. Such mirrors need to be of size up to 3.5 m in diameter, with a mass of less than 250 kg (i.e. 25 kg/m2) and possess excellent optical quality at cryogenic temperature down to 40 K.
Design of freeform optics for an ophthalmological application
NASA Astrophysics Data System (ADS)
Sieber, Ingo; Yi, Allen; Li, Likai; Beckert, Erik; Steinkopf, Ralf; Gengenbach, Ulrich
2014-05-01
Optical freeform surfaces are gaining importance in different optical applications. A huge demand arises e.g. in the fields of automotive and medical engineering. Innovative systems often need high-quality and high-volume optics. Injectionmoulded polymer optics represents a cost-efficient solution. However, it has to be ensured that the tight requirements with respect to the system's performance are met by the replicated freeform optics. To reach this goal, it is not sufficient to only characterise the manufactured optics by peak-to-valley or rms data describing a deviation from the nominal surface. Instead, optical performance of the manufactured freeform optics has to be analysed and compared with the performance of the nominal surface. This can be done by integrating the measured surface data of the manufactured freeform optics into the optical simulation model. The feedback of the measured surface data into the model allows for a simulation of the optical performance of the optical subsystem containing the real freeform optics manufactured. Hence, conclusions can be drawn as to whether the specifications with respect to e.g. imaging quality are met by the real manufactured optics. This approach will be presented using an Alvarez-Humphrey optics as an example of a tuneable optics of an ophthalmological application. The focus of this article will be on design for manufacturing the freeform optics, the integration of the measured surface data into the optical simulation model, simulation of the optical performance, and analysis in comparison to the nominal surface.
Comparison of vision through surface modulated and spatial light modulated multifocal optics.
Vinas, Maria; Dorronsoro, Carlos; Radhakrishnan, Aiswaryah; Benedi-Garcia, Clara; LaVilla, Edward Anthony; Schwiegerling, Jim; Marcos, Susana
2017-04-01
Spatial-light-modulators (SLM) are increasingly used as active elements in adaptive optics (AO) systems to simulate optical corrections, in particular multifocal presbyopic corrections. In this study, we compared vision with lathe-manufactured multi-zone (2-4) multifocal, angularly and radially, segmented surfaces and through the same corrections simulated with a SLM in a custom-developed two-active-element AO visual simulator. We found that perceived visual quality measured through real manufactured surfaces and SLM-simulated phase maps corresponded highly. Optical simulations predicted differences in perceived visual quality across different designs at Far distance, but showed some discrepancies at intermediate and near.
Comparison of vision through surface modulated and spatial light modulated multifocal optics
Vinas, Maria; Dorronsoro, Carlos; Radhakrishnan, Aiswaryah; Benedi-Garcia, Clara; LaVilla, Edward Anthony; Schwiegerling, Jim; Marcos, Susana
2017-01-01
Spatial-light-modulators (SLM) are increasingly used as active elements in adaptive optics (AO) systems to simulate optical corrections, in particular multifocal presbyopic corrections. In this study, we compared vision with lathe-manufactured multi-zone (2-4) multifocal, angularly and radially, segmented surfaces and through the same corrections simulated with a SLM in a custom-developed two-active-element AO visual simulator. We found that perceived visual quality measured through real manufactured surfaces and SLM-simulated phase maps corresponded highly. Optical simulations predicted differences in perceived visual quality across different designs at Far distance, but showed some discrepancies at intermediate and near. PMID:28736655
Doped sesquioxide ceramic for eye-safe solid state laser materials
NASA Astrophysics Data System (ADS)
Kim, Woohong; Baker, Colin; Florea, Catalin; Frantz, Jesse; Villalobos, Guillermo; Shaw, Brandon; Bowman, Steve; O'Connor, Shawn; Sadowski, Bryan; Hunt, Michael; Aggalwar, Ishwar; Sanghera, Jasbinder
2013-03-01
In this paper, we present our recent results in the development of Ho3+ doped sesquioxides for eye-safe solid state lasers. We have synthesized optical quality Lu2O3 nanopowders doped with concentrations of 0.1, 1.0, 2.0, and 5% Ho3+. The powders were synthesized by a co-precipitation method beginning with nitrates of holmium and lutetium. The nanopowders were hot pressed into optical quality ceramic discs. The optical transmission of the ceramic discs is excellent, nearly approaching the theoretical limit. The optical, spectral and morphological properties as well as the lasing performance from highly transparent ceramics are presented.
Optical quality of the living cat eye
Bonds, A. B.
1974-01-01
1. The optical quality of the living cat eye was measured under conditions similar to those of cat retinal ganglion cell experiments by recording the aerial image of a nearly monochromatic thin line of light. 2. Experiments were performed to assess the nature of the fundal reflexion of the cat eye, which was found to behave essentially as a diffuser. 3. The optical Modulation Transfer Function (MTF) was calculated from the measured aerial linespread using Fourier mathematics; the MTF of a `typical' cat eye was averaged from data collected from ten eyes. 4. The state of focus of the optical system, the pupil size and the angle of the light incident on the eye were all varied to determine their effect on image quality. 5. By using an image rotator, the aerial linespread was measured for several orientations of the line; these measurements yielded an approximation of the two-dimensional pointspread completely characterizing the optical system. 6. Evidence is reviewed to show that the optical resolution of the cat, albeit some 3-5 times worse than that of human, appears to be better than the neural resolution of its retina and its visual system as a whole. PMID:4449081
Optical quality of the living cat eye.
Bonds, A B
1974-12-01
1. The optical quality of the living cat eye was measured under conditions similar to those of cat retinal ganglion cell experiments by recording the aerial image of a nearly monochromatic thin line of light.2. Experiments were performed to assess the nature of the fundal reflexion of the cat eye, which was found to behave essentially as a diffuser.3. The optical Modulation Transfer Function (MTF) was calculated from the measured aerial linespread using Fourier mathematics; the MTF of a ;typical' cat eye was averaged from data collected from ten eyes.4. The state of focus of the optical system, the pupil size and the angle of the light incident on the eye were all varied to determine their effect on image quality.5. By using an image rotator, the aerial linespread was measured for several orientations of the line; these measurements yielded an approximation of the two-dimensional pointspread completely characterizing the optical system.6. Evidence is reviewed to show that the optical resolution of the cat, albeit some 3-5 times worse than that of human, appears to be better than the neural resolution of its retina and its visual system as a whole.
Birch, Gabriel C.; Woo, Bryana L.; Sanchez, Andres L.; ...
2017-08-24
The evaluation of optical system performance in fog conditions typically requires field testing. This can be challenging due to the unpredictable nature of fog generation and the temporal and spatial nonuniformity of the phenomenon itself. We describe the Sandia National Laboratories fog chamber, a new test facility that enables the repeatable generation of fog within a 55 m×3 m×3 m (L×W×H) environment, and demonstrate the fog chamber through a series of optical tests. These tests are performed to evaluate system image quality, determine meteorological optical range (MOR), and measure the number of particles in the atmosphere. Relationships between typical opticalmore » quality metrics, MOR values, and total number of fog particles are described using the data obtained from the fog chamber and repeated over a series of three tests.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Birch, Gabriel C.; Woo, Bryana L.; Sanchez, Andres L.
The evaluation of optical system performance in fog conditions typically requires field testing. This can be challenging due to the unpredictable nature of fog generation and the temporal and spatial nonuniformity of the phenomenon itself. We describe the Sandia National Laboratories fog chamber, a new test facility that enables the repeatable generation of fog within a 55 m×3 m×3 m (L×W×H) environment, and demonstrate the fog chamber through a series of optical tests. These tests are performed to evaluate system image quality, determine meteorological optical range (MOR), and measure the number of particles in the atmosphere. Relationships between typical opticalmore » quality metrics, MOR values, and total number of fog particles are described using the data obtained from the fog chamber and repeated over a series of three tests.« less
Yaguchi, Shigeo; Nishihara, Hitoshi; Kambhiranond, Waraporn; Stanley, Daniel; Apple, David
2008-01-01
To investigate the surface light scatter and optical quality of AcrySof lenses (Alcon Laboratories, Inc., Fort Worth, TX) following simulated aging of 20 years. AcrySof lenses were exposed to exaggerated thermal conditions to simulate up to 20 years of aging and were tested for surface light scatter and optical quality (modulation transfer function). There were no significant differences from baseline for either the surface light scatter or optical quality of the lenses over time. The current study demonstrated that surface light scatter on AcrySof lenses did not increase under conditions simulating 20 years of aging. Because the simulated aging environment contained no protein, this work indirectly supports the finding that surface light scatter is due to the deposition of a biomaterial on the lens surface rather than changes in the material. Optical performance integrity of the test lenses was maintained under severe environmental conditions.
Quality of web-based information on cannabis addiction.
Khazaal, Yasser; Chatton, Anne; Cochand, Sophie; Zullino, Daniele
2008-01-01
This study evaluated the quality of Web-based information on cannabis use and addiction and investigated particular content quality indicators. Three keywords ("cannabis addiction," "cannabis dependence," and "cannabis abuse") were entered into two popular World Wide Web search engines. Websites were assessed with a standardized proforma designed to rate sites on the basis of accountability, presentation, interactivity, readability, and content quality. "Health on the Net" (HON) quality label, and DISCERN scale scores were used to verify their efficiency as quality indicators. Of the 94 Websites identified, 57 were included. Most were commercial sites. Based on outcome measures, the overall quality of the sites turned out to be poor. A global score (the sum of accountability, interactivity, content quality and esthetic criteria) appeared as a good content quality indicator. While cannabis education Websites for patients are widespread, their global quality is poor. There is a need for better evidence-based information about cannabis use and addiction on the Web.
Association between poor sleep, fatigue, and safety outcomes in Emergency Medical Services providers
Patterson, P. Daniel; Weaver, Matthew D.; Frank, Rachel C.; Warner, Charles W.; Martin-Gill, Christian; Guyette, Francis X.; Fairbanks, Rollin J.; Hubble, Michael W.; Songer, Thomas J.; Callaway, Clifton W.; Kelsey, Sheryl F.; Hostler, David
2011-01-01
Objective To determine the association between poor sleep quality, fatigue, and self-reported safety outcomes among Emergency Medical Services (EMS) workers. Methods We used convenience sampling of EMS agencies and a cross-sectional survey design. We administered the 19-item Pittsburgh Sleep Quality Index (PSQI), 11-item Chalder Fatigue Questionnaire (CFQ), and 44-item EMS Safety Inventory (EMS-SI) to measure sleep quality, fatigue, and safety outcomes, respectively. We used a consensus process to develop the EMS-SI, which was designed to capture three composite measurements of EMS worker injury, medical errors and adverse events (AE), and safety compromising behaviors. We used hierarchical logistic regression to test the association between poor sleep quality, fatigue, and three composite measures of EMS worker safety outcomes. Results We received 547 surveys from 30 EMS agencies (a 35.6% mean agency response rate). The mean PSQI score exceeded the benchmark for poor sleep (6.9, 95%CI 6.6, 7.2). Greater than half of respondents were classified as fatigued (55%, 95%CI 50.7, 59.3). Eighteen percent of respondents reported an injury (17.8%, 95%CI 13.5, 22.1), forty-one percent a medical error or AE (41.1%, 95%CI 36.8, 45.4), and 89% (95%CI 87, 92) safety compromising behaviors. After controlling for confounding, we identified 1.9 greater odds of injury (95%CI 1.1, 3.3), 2.2 greater odds of medical error or AE (95%CI 1.4, 3.3), and 3.6 greater odds of safety compromising behavior (95%CI 1.5, 8.3) among fatigued respondents versus non-fatigued respondents. Conclusions In this sample of EMS workers, poor sleep quality and fatigue is common. We provide preliminary evidence of an association between sleep quality, fatigue, and safety outcomes. PMID:22023164
Zawadzki, Matthew J; Graham, Jennifer E; Gerin, William
2013-02-01
We examined the mechanisms that underlie the observed relationships between loneliness and depressed mood and poor sleep quality in college students. This study was the first to investigate whether rumination and trait anxiety are psychological mechanisms that mediate this relationship. In Study 1 (n = 1,244), using factor analysis with cross-sectional data, we established that loneliness and rumination are distinct constructs. We then collected survey data in two cross-sectional samples (ns = 300 and 218) and one prospective (n = 334) sample to test whether rumination and anxiety were mediators of the relationship between loneliness and depressed mood and poor sleep quality. Structural equation modeling was used to test the proposed relationships. Participants completed self-report measures of loneliness, rumination, trait anxiety, depressed mood, and sleep quality. In addition, measures of hostility, neuroticism, negative affect, and tobacco use were also assessed and tested as mediators, while social support was assessed and tested as a moderator. Consistent across the three studies, we found that rumination and trait anxiety fully mediated the associations between loneliness and depressed mood as well as poor sleep quality; these relationships held after testing all other factors. This study helps explain how loneliness dynamics relate to poor health and suggests specific points of departure for the development of interventions.
Janssen, D; Zwartelé, R E; Doets, H C; Verdonschot, N
2010-01-01
Patients suffering from rheumatoid arthritis typically have a poor subchondral bone quality, endangering implant fixation. Using finite element analysis (FEA) an investigation was made to find whether a press-fit acetabular implant with a polar clearance would reduce interfacial micromotions and improve fixation compared with a standard hemispherical design. In addition, the effects of interference fit, friction, and implant material were analysed. Cups were introduced into an FEA model of a human pelvis with simulated subchondral bone plasticity. The models were loaded with a loading configuration simulating two cycles of normal walking, during which contact stresses and interfacial micromotions were monitored. Subsequently, a lever-out simulation was performed to assess the fixation strength of the various cases. A flattened cup with good bone quality produced the lowest interfacial micromotions. Poor bone decreased the fixation strength regardless of the geometry of the cup. Increasing the interference fit of the flattened cup compensated for the loss of fixation strength caused by poor bone quality. In conclusion, a flattened cup did not significantly improve implant fixation over a hemispherical cup in the case of poor bone quality. However, implant fixation can be optimized by increasing interference fit and avoiding inferior frictional properties and low-stiffness implants.
The 3C 279 Campaign of Winter 1999: A Gamma-Optical Correlation?
NASA Technical Reports Server (NTRS)
Hartman, R. C.; Villata, M.; Raiteri, C. M.; Sobrito, M.; DeFrancesco, G.; Ostorero, L.; Tosti, G.; Kurtanidze, O.; Nikolashvili, M.; Takalo, L.
2000-01-01
Preliminary results are presented from the gamma-optical campaign of January-February 1999 on 3C 279. During this period we obtained good optical sampling of the source, the best ever for a gamma-bright OVV quasar. Its large and fast variations have been compared with the gamma-ray fluxes obtained simultaneously by Energy Gamma Ray Experiment Telescope (EGRET), on Compton Gamma Ray Observatory (CGRO). Despite rather poor counting statistics in the gamma-ray data, a fair correlation is found, with the gamma variations following those in the optical by 3-4 days. This is the first time such a significant day-scale correlation has been observed between the optical and gamma emissions from a OVV quasar. Its implications are currently under study.
PRINTQUAL - a measure for assessing the quality of newspaper reporting of suicide.
John, Ann; Hawton, Keith; Lloyd, Keith; Luce, Ann; Platt, Stephen; Scourfield, Jonathan; Marchant, Amanda L; Jones, Phil A; Dennis, Mick S
2014-01-01
Many studies have demonstrated a relationship between newspaper reporting of actual or fictional suicides and subsequent suicidal behaviors. Previous measures of the quality of reporting lack consistency concerning which specific elements should be included and how they should be weighted. To develop an instrument, PRINTQUAL, comprising two scales of the quality (poor and good) of newspaper reporting of suicide that can be used in future studies of reporting. A first draft of the PRINTQUAL instrument was compiled, comprising items indicative of poor- and good-quality newspaper reporting based on guidelines and key sources of evidence. This was refined by team members and then circulated to a group of international experts in the field for further opinion and weighting of individual items. The final instrument comprised 19 items in the poor-quality scale and four in the good-quality scale. Following training, agreement between raters was acceptably high for most items (κ ≥ .75) except for three items for which agreement was still acceptable (κ ≥ .60). The PRINTQUAL instrument for assessing the quality of newspaper reporting of suicide appears appropriate for use in research and monitoring in future studies.
Alsaggaf, Mohammed A; Wali, Siraj O; Merdad, Roah A; Merdad, Leena A
2016-02-01
To determine sleep habits and sleep quality in medical students during their clinical years using validated measures; and to investigate associations with academic performance and psychological stress. In this cross-sectional study, medical students (n=320) were randomly selected from a list of all enrolled clinical-year students in a Saudi medical school from 2011-2012. Students filled a questionnaire including demographic and lifestyle factors, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Perceived Stress Scale. Students acquired on average, 5.8 hours of sleep each night, with an average bedtime at 01:53. Approximately 8% reported acquiring sleep during the day, and not during nighttime. Poor sleep quality was present in 30%, excessive daytime sleepiness (EDS) in 40%, and insomnia symptoms in 33% of students. Multivariable regression models revealed significant associations between stress, poor sleep quality, and EDS. Poorer academic performance and stress were associated with symptoms of insomnia. Sleep deprivation, poor sleep quality, and EDS are common among clinical years medical students. High levels of stress and the pressure of maintaining grade point averages may be influencing their quality of sleep.
Sleep quantity, quality, and insomnia symptoms of medical students during clinical years
Alsaggaf, Mohammed A.; Wali, Siraj O.; Merdad, Roah A.; Merdad, Leena A.
2016-01-01
Objectives: To determine sleep habits and sleep quality in medical students during their clinical years using validated measures; and to investigate associations with academic performance and psychological stress. Methods: In this cross-sectional study, medical students (n=320) were randomly selected from a list of all enrolled clinical-year students in a Saudi medical school from 2011-2012. Students filled a questionnaire including demographic and lifestyle factors, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Perceived Stress Scale. Results: Students acquired on average, 5.8 hours of sleep each night, with an average bedtime at 01:53. Approximately 8% reported acquiring sleep during the day, and not during nighttime. Poor sleep quality was present in 30%, excessive daytime sleepiness (EDS) in 40%, and insomnia symptoms in 33% of students. Multivariable regression models revealed significant associations between stress, poor sleep quality, and EDS. Poorer academic performance and stress were associated with symptoms of insomnia. Conclusion: Sleep deprivation, poor sleep quality, and EDS are common among clinical years medical students. High levels of stress and the pressure of maintaining grade point averages may be influencing their quality of sleep. PMID:26837401
A space satellite perspective to monitor water quality using ...
Good water quality is important for human health, economic development, and the health of our environment. Across the country, we face the challenge of degraded water quality in many of our rivers, lakes, coastal regions and oceans. The EPA National Rivers and Stream Assessment report found that more than half - 55 percent - of our rivers and streams are in poor condition for aquatic life. Likewise, the EPA Lakes Assessment found that 22 percent of our lakes are in poor condition for aquatic life. The reasons for unhealthy water quality are vast. Likewise, poor water quality has numerous impacts to ecosystems. One indicator, which trends during warm weather months, is the duration and frequency of harmful algal blooms. A healthy environment includes good water quality to support a rich and varied ecosystem, economic growth, and protects the health of the people in the community who rely on that water. Having the ability to monitor and provide timely response to harmful algal blooms would be one step in protecting the benefits people receive from good water quality (U.S. EPA 2010 and 2013). Published in the North American Lake Management Society-LakeLine Magazine.
Current Scenario of Spurious and Substandard Medicines in India: A Systematic Review
Khan, A. N.; Khar, R. K.
2015-01-01
Globally, every country is the victim of substandard or spurious drugs, which result in life threatening issues, financial loss of consumer and manufacturer and loss in trust on health system. The aim of this enumerative review was to probe the extent on poor quality drugs with their consequences on public health and the preventive measures taken by the Indian pharmaceutical regulatory system. Government and non-government studies, literature and news were gathered from journals and authentic websites. All data from 2000 to 2013 were compiled and interpreted to reveal the real story of poor quality drugs in India. For minimizing spurious/falsely-labelled/falsified/counterfeit drugs or not of standard quality drugs, there is urgent requirement of more stringent regulation and legal action against the problem. However, India has taken some preventive steps in the country to fight against the poor quality drugs for protecting and promoting the public health. PMID:25767312
USDA-ARS?s Scientific Manuscript database
Poor diet quality in childhood and adolescence is associated with adverse health outcomes throughout life, yet the dietary habits of American children and how they change across childhood and adolescence are unknown. This study sought to describe diet quality among children and adolescents by assess...
ERIC Educational Resources Information Center
Martin, Christopher; Solorzano, Cristian
2003-01-01
Claims that public education in Mexico is in severe crisis. Indicates the wealthy have opted out of public education and the poor are dropping out. Argues that reforms to address poor quality and inequalities are being sidestepped. Proposes a more inclusive educational approaches to provide quality education for all. (CAJ)
Lorber, Michael F; Egeland, Byron
2009-07-01
Developmental models and previous findings suggest that early parenting is more strongly associated with externalizing problems in early childhood than it is in adolescence. In this article, the authors address whether the association of poor-quality infancy parenting and externalizing problems "rebounds" in adulthood. Poor-quality infancy parenting was associated with externalizing problems at kindergarten and first grade (mother report) as well as at 23 and 26 years (self report). Infancy parenting was not significantly associated with either mothers' or youths' reports of externalizing problems at 16 years. These findings are consistent with the notion that poor-quality infancy parenting is a risk factor for externalizing problems in developmental periods for which externalizing behavior is most deviant.
Wavefront aberrations and retinal image quality in different lenticular opacity types and densities.
Wu, Cheng-Zhe; Jin, Hua; Shen, Zhen-Nv; Li, Ying-Jun; Cui, Xun
2017-11-10
To investigate wavefront aberrations in the entire eye and in the internal optics (lens) and retinal image qualities according to different lenticular opacity types and densities. Forty-one eyes with nuclear cataract, 33 eyes with cortical cataract, and 29 eyes with posterior subcapsular cataract were examined. In each group, wavefront aberrations in the entire eye and in the internal optics and retinal image quality were measured using a raytracing aberrometer. Eyes with cortical cataracts showed significantly higher coma-like aberrations compared to the other two groups in both entire eye and internal optic aberrations (P = 0.012 and P = 0.007, respectively). Eyes with nuclear cataract had lower spherical-like aberrations than the other two groups in both entire eye and internal optics aberrations (P < 0.001 and P < 0.001, respectively). In the nuclear cataract group, nuclear lens density was negatively correlated with internal spherical aberrations (r = -0.527, P = 0.005). Wavefront technology is useful for objective and quantitative analysis of retinal image quality deterioration in eyes with different early lenticular opacity types and densities. Understanding the wavefront optical properties of different crystalline lens opacities may help ophthalmic surgeons determine the optimal time to perform cataract surgery.
USDA-ARS?s Scientific Manuscript database
A multichannel hyperspectral imaging probe with 30 optic fibers covering the wavelength range of 550-1,650 nm and the light source-detector distances of 1.5-36 mm was recently developed for optical property measurement and quality evaluation of food products with flat or curved surface. This paper r...
A six sigma review of miniature optics alignment
NASA Astrophysics Data System (ADS)
Tesar, John
2009-08-01
The key to high quality optics is a set of guidelines. Create an understanding of the Criteria for Quality. Focus on understanding and controlling process variation. Examine verification and validation of methods. Take a view of the horizon as well as drilling down so you know when to put down the shovel.
Duncan, Dustin T.; Goedel, William C.; Mayer, Kenneth H.; Safren, Steven A.; Palamar, Joseph J.; Hagen, Daniel; Jean-Louis, Girardin
2017-01-01
Objectives The purpose of this study was to evaluate the prevalence of poor sleep health (ie, poor sleep quality and short sleep duration) in a sample of men who have sex with men (MSM). In addition, this study examined whether poor sleep health was associated with depressive symptoms, substance use, and sexual risk behaviors in this sample. Design Cross-sectional survey. Participants Broadcast advertisements were placed on a popular smartphone application for MSM in January 2016 to recruit users in the London metropolitan area (n = 202) to complete a Web-based survey, which included validated measures of sleep quality and duration. Measurements Poor sleep quality was defined based on self-report as very or fairly bad. Short sleep duration was defined as less than 7 hours each night. Regression models were used to assess associations between sleep variables and self-reported depressive symptoms, substance use, and sexual risk behaviors. Results About one-third (34.6%) of the respondents reported poor sleep quality and almost half (43.6%) reported sleeping less than 7 hours every night. Several poor sleep health variables were independently associated with depressive symptoms, substance use (eg, use of alcohol or marijuana), and condomless anal intercourse. For example, typical nightly sleep duration of less than 7 hours was associated with condomless receptive anal intercourse with a higher number of sexual partners (incidence rate ratio, 2.65; 95% confidence interval: 1.63–4.30; P < .001). Conclusion Sleep health promotion interventions should be developed for MSM, which may promote positive mental health as well as reduce substance use and sexual risk behaviors in this population. PMID:29073390
Duncan, Dustin T; Goedel, William C; Mayer, Kenneth H; Safren, Steven A; Palamar, Joseph J; Hagen, Daniel; Jean-Louis, Girardin
2016-12-01
The purpose of this study was to evaluate the prevalence of poor sleep health (ie, poor sleep quality and short sleep duration) in a sample of men who have sex with men (MSM). In addition, this study examined whether poor sleep health was associated with depressive symptoms, substance use, and sexual risk behaviors in this sample. Cross-sectional survey. Broadcast advertisements were placed on a popular smartphone application for MSM in January 2016 to recruit users in the London metropolitan area (n=202) to complete a Web-based survey, which included validated measures of sleep quality and duration. Poor sleep quality was defined based on self-report as very or fairly bad. Short sleep duration was defined as less than 7 hours each night. Regression models were used to assess associations between sleep variables and self-reported depressive symptoms, substance use, and sexual risk behaviors. About one-third (34.6%) of the respondents reported poor sleep quality and almost half (43.6%) reported sleeping less than 7 hours every night. Several poor sleep health variables were independently associated with depressive symptoms, substance use (eg, use of alcohol or marijuana), and condomless anal intercourse. For example, typical nightly sleep duration of less than 7 hours was associated with condomless receptive anal intercourse with a higher number of sexual partners (incidence rate ratio, 2.65; 95% confidence interval: 1.63-4.30; P<.001). Sleep health promotion interventions should be developed for MSM, which may promote positive mental health as well as reduce substance use and sexual risk behaviors in this population. Copyright \\© 2016 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.
Sun, Dong-Xiao; Li, Jin-Hua; Fang, Xuan; Chen, Xin-Ying; Fang, Fang; Chu, Xue-Ying; Wei, Zhi-Peng; Wang, Xiao-Hua
2014-07-01
In the present paper, we report the research on the effects of annealing temperature on the crystal quality and optical properties of ZnMgO films deposited by atom layer deposition(ALD). ZnMgO films were prepared on quartz substrates by ALD and then some of the samples were treated in air ambient at different annealing temperature. The effects of annealing temperature on the crystal quality and optical properties of ZnMgO films were characterized by X-ray diffraction (XRD), photoluminescence (PL) and ultraviolet-visible (UV-Vis) absorption spectra. The XRD results showed that the crystal quality of ZnMgO films was significantly improved when the annealing temperature was 600 degrees C, meanwhile the intensity of(100) diffraction peak was the strongest. Combination of PL and UV-Vis absorption measurements showed that it can strongly promote the Mg content increasing in ZnMgO films and increase the band gap of films. So the results illustrate that suitable annealing temperature can effectively improve the crystal quality and optical properties of ZnMgO films.
Schmidt, Roman; Engelhardt, Johann; Lang, Marion
2013-01-01
Optical microscopy has become a key technology in the life sciences today. Its noninvasive nature provides access to the interior of intact and even living cells, where specific molecules can be precisely localized by fluorescent tagging. However, the attainable 3D resolution of an optical microscope has long been hampered by a comparatively poor resolution along the optic axis. By coherent focusing through two objective lenses, 4Pi microscopy improves the axial resolution by three- to fivefold. This primer is intended as a starting point for the design and operation of a 4Pi microscope of type A.
Observation of fast scintillation of cryogenic PbI/sub 2/ with VLPCs
NASA Astrophysics Data System (ADS)
Moses, W. W.; Choong, W.-S.; Derenzo, S. E.; Bross, A. D.; Dysert, R.; Rykalin, V. V.; Shah, K. S.; Klugerman, M.
2004-10-01
At cryogenic temperatures (/spl sim/10 K), undoped lead iodide (PbI/sub 2/) has material and scintillation properties that are very attractive for positron emission tomography (PET). However, the PbI/sub 2/ emissions are quenched at temperatures >40 K, so close optical coupling between the scintillator and photodetector requires a photodetector that also operates at cryogenic temperatures. This suggests the visible light photon counter (VLPC), which operates at similar temperatures and combines high gain and high quantum efficiency. We proximity couple (0.001 in air gap) PbI/sub 2/ crystals with 1.0-2.5 mm dimensions to a 1 mm diameter VLPC and cool the system to 8.5 K. Signals with short (<10 ns) duration are observed. When excited with 511 keV photons, a coincidence timing resolution of 1.3 ns full-width at half-maximum is measured. While a clear photopeak is observed for 122 keV excitation, no clear photopeak is seen under 511 keV excitation (possibly due to the poor optical quality of the PbI/sub 2/ crystals). While the present configuration must be scaled-up considerably, a cryogenic PbI/sub 2//VLPC combination may eventually become the basis for a practical time-of-flight PET camera.
Research Note: Unmet Needs for Education of Primary School Children in Nigeria.
ERIC Educational Resources Information Center
Abidoye, Rotimi O.
1999-01-01
Surveyed 300 children and 300 teachers in Lagos, Nigeria to determine unmet needs for education. Reasons given for poor-quality education included poor teacher morale, poor parent cooperation, and poor child interest, the latter attributed to chronic malnutrition and illness. Suggestions were made for proper teacher training, adequate…
Production system with process quality control: modelling and application
NASA Astrophysics Data System (ADS)
Tsou, Jia-Chi
2010-07-01
Over the past decade, there has been a great deal of research dedicated to the study of quality and the economics of production. In this article, we develop a dynamic model which is based on the hypothesis of a traditional economic production quantity model. Taguchi's cost of poor quality is used to evaluate the cost of poor quality in the dynamic production system. A practical case from the automotive industry, which uses the Six-sigma DMAIC methodology, is discussed to verify the proposed model. This study shows that there is an optimal value of quality investment to make the production system reach a reasonable quality level and minimise the production cost. Based on our model, the management can adjust its investment in quality improvement to generate considerable financial return.
qF-SSOP: real-time optical property corrected fluorescence imaging
Valdes, Pablo A.; Angelo, Joseph P.; Choi, Hak Soo; Gioux, Sylvain
2017-01-01
Fluorescence imaging is well suited to provide image guidance during resections in oncologic and vascular surgery. However, the distorting effects of tissue optical properties on the emitted fluorescence are poorly compensated for on even the most advanced fluorescence image guidance systems, leading to subjective and inaccurate estimates of tissue fluorophore concentrations. Here we present a novel fluorescence imaging technique that performs real-time (i.e., video rate) optical property corrected fluorescence imaging. We perform full field of view simultaneous imaging of tissue optical properties using Single Snapshot of Optical Properties (SSOP) and fluorescence detection. The estimated optical properties are used to correct the emitted fluorescence with a quantitative fluorescence model to provide quantitative fluorescence-Single Snapshot of Optical Properties (qF-SSOP) images with less than 5% error. The technique is rigorous, fast, and quantitative, enabling ease of integration into the surgical workflow with the potential to improve molecular guidance intraoperatively. PMID:28856038
Impact of extended defects on optical properties of (1-101)GaN grown on patterned Si
NASA Astrophysics Data System (ADS)
Okur, S.; Izyumskaya, N.; Zhang, F.; Avrutin, V.; Metzner, S.; Karbaum, C.; Bertram, F.; Christen, J.; Morkoç, H.; Özgür, Ü.
2014-03-01
The optical quality of semipolar (1 101)GaN layers was explored by time- and polarization-resolved photoluminescence spectroscopy. High intensity bandedge emission was observed in +c-wing regions of the stripes as a result of better structural quality, while -c-wing regions were found to be of poorer optical quality due to basal plane and prismatic stacking faults (BSFs and PSFs) in addition to a high density of TDs. The high optical quality region formed on the +cwings was evidenced also from the much slower biexponential PL decays (0.22 ns and 1.70 ns) and an order of magnitude smaller amplitude ratio of the fast decay (nonradiative origin) to the slow decay component (radiative origin) compared to the -c-wing regions. In regard to defect-related emission, decay times for the BSF and PSF emission lines at 25 K (~ 0.80 ns and ~ 3.5 ns, respectively) were independent of the excitation density within the range employed (5 - 420 W/cm2), and much longer than that for the donor bound excitons (0.13 ns at 5 W/cm2 and 0.22 ns at 420 W/cm2). It was also found that the emission from BSFs had lower polarization degree (0.22) than that from donor bound excitons (0.35). The diminution of the polarization degree when photogenerated carriers recombine within the BSFs is another indication of the negative effects of stacking faults on the optical quality of the semipolar (1101)GaN. In addition, spatial distribution of defects in semipolar (1101)-oriented InGaN active region layers grown on stripe patterned Si substrates was investigated using near-field scanning optical microscopy. The optical quality of -c- wing regions was found to be worse compared to +c-wing regions due to the presence of higher density of stacking faults and threading dislocations. The emission from the +c-wings was very bright and relatively uniform across the sample, which is indicative of a homogeneous In distribution.
Recent developments in CO2 lasers
NASA Astrophysics Data System (ADS)
Du, Keming
1993-05-01
CO2 lasers have been used in industry mainly for such things as cutting, welding, and surface processing. To conduct a broad spectrum of high-speed and high-quality applications, most of the developments in industrial CO2 lasers at the ILT are aimed at increasing the output power, optimizing the beam quality, and reducing the production costs. Most of the commercial CO2 lasers above 5 kW are transverse-flow systems using dc excitation. The applications of these lasers are limited due to the lower beam quality, the poor point stability, and the lower modulation frequency. To overcome the problems we developed a fast axial- flow CO2 laser using rf excitation with an output of 13 kW. In section 2 some of the results are discussed concerning the gas flow, the discharge, the resonator design, optical effects of active medium, the aerodynamic window, and the modulation of the output power. The first CO2 lasers ever built are diffusion-cooled systems with conventional dc excited cylindrical discharge tubes surrounded by cooling jackets. The output power per unit length is limited to 50 W/m by those lasers with cylindrical tubes. In the past few years considerable increases in the output power were achieved, using new mechanical geometries, excitation- techniques, and resonator designs. This progress in diffusion-cooled CO2 lasers is presented in section 3.
NASA Technical Reports Server (NTRS)
Abdeldayem, Hossin; Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin; Witherow, William K.; Bank, Curtis; Shields, Angela; Hicks, Rosline; Ashley, Paul R.
1996-01-01
In this paper, we will take a closer look at the state of the art of polydiacetylene, and metal-free phthalocyanine films, in view of the microgravity impact on their optical properties, their nonlinear optical properties and their potential advantages for integrated optics. These materials have many attractive features with regard to their use in integrated optical circuits and optical switching. Thin films of these materials processed in microgravity environment show enhanced optical quality and better molecular alignment than those processed in unit gravity. Our studies of these materials indicate that microgravity can play a major role in integrated optics technology. Polydiacetylene films are produced by UV irradiation of monomer solution through an optical window. This novel technique of forming polydiacetylene thin films has been modified for constructing sophisticated micro-structure integrated optical patterns using a pre-programmed UV-Laser beam. Wave guiding through these thin films by the prism coupler technique has been demonstrated. The third order nonlinear parameters of these films have been evaluated. Metal-free phthalocyanine films of good optical quality are processed in our laboratories by vapor deposition technique. Initial studies on these films indicate that they have excellent chemical, laser, and environmental stability. They have large nonlinear optical parameters and show intrinsic optical bistability. This bistability is essential for optical logic gates and optical switching applications. Waveguiding and device making investigations of these materials are underway.
Act Consortium Drug Quality Project Team And The Impact Study Team
2015-06-01
Ensuring that artemisinin-containing antimalarials (ACAs) are of good quality is a key component of effective malaria treatment. There are concerns that a high proportion of ACAs are falsified or substandard, though estimates are rarely based on representative data. During a nationally representative survey in Tanzania, ACAs were purchased from private retail drug outlets, and the active pharmaceutical ingredient (API) was measured. All 1,737 ACAs contained the labeled artemisinin derivative, with 4.1% being outside the 85-115% artemisinin API range defined as acceptable quality. World Health Organization (WHO) prequalified drugs had 0.1 times the odds of being poor quality compared with non-prequalified ACAs for the artemisinin component. When partner components of combination therapies were also considered, 12.1% were outside the acceptable API range, and WHO prequalified ACAs had 0.04 times the odds of being poor quality. Although the prevalence of poor quality ACAs was lower than reported elsewhere, the minority of samples found to be substandard is a cause for concern. Improvements in quality could be achieved by increasing the predominance of WHO prequalified products in the market. Continued monitoring of quality standards is essential. © The American Society of Tropical Medicine and Hygiene.
A Comparison of Spectacles Purchased Online and in UK Optometry Practice
Alderson, Alison J.; Green, Alison; Whitaker, David; Scally, Andrew J.; Elliott, David B.
2016-01-01
ABSTRACT Purpose To compare spectacles bought online with spectacles from optometry practices. Methods Thirty-three participants consisting of single vision spectacle wearers with either a low (N = 12, mean age 34 ± 14 years) or high prescription (N = 11, mean age 28 ± 9 years) and 10 presbyopic participants (mean age 59 ± 4 years) wearing progressive addition lenses (PALs) purchased 154 pairs of spectacles online and 154 from UK optometry practices. The spectacles were compared via participant-reported preference, acceptability, and safety; the assessment of lens, frame, and fit quality; and the accuracy of the lens prescriptions to international standard ISO 21987:2009. Results Participants preferred the practice spectacles (median ranking 4th, IQR 1–6) more than online (6th, IQR 4–8; Mann-Whitney U = 7345, p < 0.001) and practice PALs (median ranking 2nd, IQR 1–4) were particularly preferred (online 6.5th, IQR 4–9, Mann-Whitney U = 455, p < 0.001). Of those deemed unacceptable and unsafe, significantly more were bought online (unacceptable: online 43/154 vs. practice 15/154, Fisher’s exact p = 0.0001; unsafe: online 14/154 vs. practice 5/154, Fisher’s exact p = 0.03). Conclusions Participants preferred spectacles from optometry practice rather than those bought online, despite lens quality and prescription accuracy being similar. A greater number of online spectacles were deemed unsafe or unacceptable because of poor spectacle frame fit, poor cosmetic appearance, and inaccurate optical centration. This seems particularly pertinent to PAL lenses, which are known to increase falls risk. Recommendations are made to improve both forms of spectacle provision. PMID:27536974
Electro-Optic Identification Research Program
2002-04-01
Electro - optic identification (EOID) sensors provide photographic quality images that can be used to identify mine-like contacts provided by long...tasks such as validating existing electro - optic models, development of performance metrics, and development of computer aided identification and
Applications for Freeforms Optics at NASA
NASA Technical Reports Server (NTRS)
West, Garrett J.; Howard, Joseph M.
2017-01-01
Review freeform optic applications as NASA. Describe design study results showing benefits of freeform optics to the instrument size, image quality, and field of view. Review areas of study and improvements needed to freeform manufacturing for future applications.
Novel, compact, and simple ND:YVO4 laser with 12 W of CW optical output power and good beam quality
NASA Astrophysics Data System (ADS)
Zimer, H.; Langer, B.; Wittrock, U.; Heine, F.; Hildebrandt, U.; Seel, S.; Lange, R.
2017-11-01
We present first, promising experiments with a novel, compact and simple Nd:YVO4 slab laser with 12 W of 1.06 μm optical output power and a beam quality factor M2 2.5. The laser is made of a diffusion-bonded YVO4/Nd:YVO4 composite crystal that exhibits two unique features. First, it ensures a one-dimensional heat removal from the laser crystal, which leads to a temperature profile without detrimental influence on the laser beam. Thus, the induced thermo-optical aberrations to the laser field are low, allowing power scaling with good beam quality. Second, the composite crystal itself acts as a waveguide for the 809 nm pump-light that is supplied from a diode laser bar. Pump-light shaping optics, e.g. fast- or slow-axis collimators can be omitted, reducing the complexity of the system. Pump-light redundancy can be easily achieved. Eventually, the investigated slab laser might be suitable for distortion-free high gain amplification of weak optical signals.
Natali, Pier Paolo; Montalto, Luigi; Daví, Fabrizio; Mengucci, Paolo; Ciriaco, Andrea; Paone, Nicola; Rinaldi, Daniele
2018-02-01
The tetragonal PbWO 4 (PWO) is one of the most important scintillating crystals, being used both in the Compact Muon Solenoid (CMS) experiment at the European Organization for Nuclear Research (CERN) and in the PANDA project at the Facility for Antiproton and Ion Research (FAIR). Light yield and other relevant scintillation properties depend, among many factors, also on the crystal mechanical quality. Accordingly, a detailed knowledge of crystal piezo-optic properties is a mandatory step toward understanding elasto-optic behavior and performing crystal quality control. In this paper, we evaluate for the first time, to the best of our knowledge, by means of both photoelastic and x-ray measurements, some components of the piezo-optic tensor; moreover, when the crystal is acted upon by a uniaxial stress, we obtain an evaluation for the rotation angle of the optic plane under stress as well as the photoelastic constant. These parameters are necessary to detect the residual stresses within the crystal, if any, and to give an overall quality measure. Such a methodology is in general suitable for any tetragonal crystals.
Low optical-loss facet preparation for silica-on-silicon photonics using the ductile dicing regime
NASA Astrophysics Data System (ADS)
Carpenter, Lewis G.; Rogers, Helen L.; Cooper, Peter A.; Holmes, Christopher; Gates, James C.; Smith, Peter G. R.
2013-11-01
The efficient production of high-quality facets for low-loss coupling is a significant production issue in integrated optics, usually requiring time consuming and manually intensive lapping and polishing steps, which add considerably to device fabrication costs. The development of precision dicing saws with diamond impregnated blades has allowed optical grade surfaces to be machined in crystalline materials such as lithium niobate and garnets. In this report we investigate the optimization of dicing machine parameters to obtain optical quality surfaces in a silica-on-silicon planar device demonstrating high optical quality in a commercially important glassy material. We achieve a surface roughness of 4.9 nm (Sa) using the optimized dicing conditions. By machining a groove across a waveguide, using the optimized dicing parameters, a grating based loss measurement technique is used to measure precisely the average free space interface loss per facet caused by scattering as a consequence of surface roughness. The average interface loss per facet was calculated to be: -0.63 dB and -0.76 dB for the TE and TM polarizations, respectively.
Nanomechanical control of optical field and quality factor in photonic crystal structures
NASA Astrophysics Data System (ADS)
Cotrufo, Michele; Midolo, Leonardo; Zobenica, Žarko; Petruzzella, Maurangelo; van Otten, Frank W. M.; Fiore, Andrea
2018-03-01
Actively controlling the properties of localized optical modes is crucial for cavity quantum electrodynamics experiments. While several methods to tune the optical frequency have been demonstrated, the possibility of controlling the shape of the modes has scarcely been investigated. Yet an active manipulation of the mode pattern would allow direct control of the mode volume and the quality factor and therefore of the radiative processes. In this work, we propose and demonstrate a nano-optoelectromechanical device in which a mechanical displacement affects the spatial pattern of the electromagnetic field. The device is based on a double-membrane photonic crystal waveguide which, upon bending, creates a spatial modulation of the effective refractive index, resulting in an effective potential well or antiwell for the optical modes. The change in the field pattern drastically affects the optical losses: large modulations of the quality factors and dissipative coupling rates larger than 1 GHz/nm are predicted by calculations and confirmed by experiments. This concept opens new avenues in solid-state cavity quantum electrodynamics in which the field, instead of the frequency, is coupled to the mechanical motion.
Image transport through a disordered optical fibre mediated by transverse Anderson localization.
Karbasi, Salman; Frazier, Ryan J; Koch, Karl W; Hawkins, Thomas; Ballato, John; Mafi, Arash
2014-02-25
Transverse Anderson localization of light allows localized optical-beam-transport through a transversely disordered and longitudinally invariant medium. Its successful implementation in disordered optical fibres recently resulted in the propagation of localized beams of radii comparable to that of conventional optical fibres. Here we demonstrate optical image transport using transverse Anderson localization of light. The image transport quality obtained in the polymer disordered optical fibre is comparable to or better than some of the best commercially available multicore image fibres with less pixelation and higher contrast. It is argued that considerable improvement in image transport quality can be obtained in a disordered fibre made from a glass matrix with near wavelength-size randomly distributed air-holes with an air-hole fill-fraction of 50%. Our results open the way to device-level implementation of the transverse Anderson localization of light with potential applications in biological and medical imaging.
Inspection of the interior surface of cylindrical vessels using optic fiber shearography
NASA Astrophysics Data System (ADS)
Liu, Bin; Wei, Quan; Tu, Jun; Arola, Dwayne D.; Zhang, Dongsheng
2017-09-01
In this study, a shearography system integrated with a coherent fiber-optic illumination and a fiber-optic imaging bundle is presented to inspect the quality of the interior surface of a cylindrical vessel for safety purposes. The specific optical arrangement is designed for the inspection of a certain area at a small working distance. The optical arrangement of the system was assembled and an aluminum honeycomb sample was evaluated to demonstrate the capability of the system. The important relationship between the image quality and the working distance, as well as the field of view, is discussed. The system has been applied for the inspection of the interior surface of a cylindrical vessel. The experimental results suggest that the shearography system integrated with optical and image fibers can effectively minimize the size of the inspection device and be capable of evaluating the interior surface of cylindrical structures.
de Man, H; Leenen, E J T M; van Knapen, F; de Roda Husman, A M
2014-09-01
Splash parks have been associated with infectious disease outbreaks as a result of exposure to poor water quality. To be able to protect public health, risk factors were identified that determine poor water quality. Samples were taken at seven splash parks where operators were willing to participate in the study. Higher concentrations of Escherichia coli were measured in water of splash parks filled with rainwater or surface water as compared with sites filled with tap water, independent of routine inspection intervals and employed disinfection. Management practices to prevent fecal contamination and guarantee maintaining good water quality at splash parks should include selection of source water of acceptable quality.
Controlled dehydration improves the diffraction quality of two RNA crystals.
Park, HaJeung; Tran, Tuan; Lee, Jun Hyuck; Park, Hyun; Disney, Matthew D
2016-11-03
Post-crystallization dehydration methods, applying either vapor diffusion or humidity control devices, have been widely used to improve the diffraction quality of protein crystals. Despite the fact that RNA crystals tend to diffract poorly, there is a dearth of reports on the application of dehydration methods to improve the diffraction quality of RNA crystals. We use dehydration techniques with a Free Mounting System (FMS, a humidity control device) to recover the poor diffraction quality of RNA crystals. These approaches were applied to RNA constructs that model various RNA-mediated repeat expansion disorders. The method we describe herein could serve as a general tool to improve diffraction quality of RNA crystals to facilitate structure determinations.
NASA Astrophysics Data System (ADS)
Hu, Feng; Zhou, Jin-peng; Wang, Xing-shu
2017-08-01
Aiming at the deficiency of the traditional postgraduate education mode for professional degree, such as the conflict between work and study, restricted supply and demand and poor efficiency of course teaching, the emergence of Massive Open Online Course (MOOC) which has large scale, online and open features can make up for the shortage of traditional professional degree postgraduate education mode by introducing MOOC teaching mode. However, it is still a fangle to integrate MOOC into the traditional postgraduate education for professional degree and there are no standard methods for reference in the construction of MOOC courses as well as the corresponding evaluations. In this paper, the construction method and practical experience of MOOC courses for professional degree postgraduate education are discussed in details, based on the MOOC course of Introduction to Engineering Optics. Firstly, the principle of MOOC course contents for professional degree postgraduate education is introduced from the aspects of students' demand, MOOC features and practical applications. Secondly, the optimization of MOOC teaching mode is discussed in order to improve the teaching quality and learning efficiency. Thirdly, in order to overcome the deficiency of current MOOC examination schemes, a novel MOOC evaluation scheme is proposed which is capable of assessing students' learning attitude as well as their ability and performance differences. Finally, a practical summary is given about how to integrate the MOOC teaching mode into the postgraduate education for professional degree, including the constructions of teaching team, course system as well as other factors. From the paper, we can conclude that the integration of MOOC teaching mode into the postgraduate education for professional degree will improve the teaching quality and efficiency.
A novel type of very long baseline astronomical intensity interferometer
NASA Astrophysics Data System (ADS)
Borra, Ermanno F.
2013-12-01
This article presents a novel type of very long baseline astronomical interferometer that uses the fluctuations, as a function of time, of the intensity measured by a quadratic detector, which is a common type of astronomical detector. The theory on which the technique is based is validated by laboratory experiments. Its outstanding principal advantages comes from the fact that the angular structure of an astronomical object is simply determined from the visibility of the minima of the spectrum of the intensity fluctuations measured by the detector, as a function of the frequency of the fluctuations, while keeping the spacing between mirrors constant. This would allow a simple setup capable of high angular resolutions because it could use an extremely large baseline. Another major interest is that it allows for a more efficient use of telescope time because observations at a single baseline are sufficient, while amplitude and intensity interferometers need several observations at different baselines. The fact that one does not have to move the telescopes would also allow detecting faster time variations because having to move the telescopes sets a lower limit to the time variations that can be detected. The technique uses wave interaction effects and thus has some characteristics in common with intensity interferometry. A disadvantage of the technique, like in intensity interferometry, is that it needs strong sources if observing at high frequencies (e.g. the visible). This is a minor disadvantage in the radio region. At high frequencies, this disadvantage is mitigated by the fact that, like in intensity interferometry, the requirements of the optical quality of the mirrors used are far less severe than in amplitude interferometry so that poor quality large reflectors (e.g. Cherenkov telescopes) can be used in the optical region.
Troxel, Wendy M; Booth, Marika; Buysse, Daniel J; Elliott, Marc N; Suskind, Anne M; Clemens, J Quentin; Berry, Sandra H
2014-12-15
To characterize the nature and impact of sleep disturbances on quality of life (QOL) in women with interstitial cystitis/bladder pain syndrome (IC/BPS). Participants were 3,397 women from a telephone probability survey who met IC/BPS symptom criteria. Sleep quality, duration, and IC/BPS nocturnal symptoms (i.e., trouble sleeping due to bladder pain, urgency, or needing to use the bathroom), general QOL (mental and physical health and sexual functioning), and IC/BPS QOL impairment were assessed via self-report during telephone interview. Over half of the sample reported poor sleep quality, sleep duration ≤ 6 hours, or trouble sleeping due to IC/BPS symptoms. After covariate adjustment, short sleep duration was significantly associated with greater IC/BPS QOL impairment (β = -0.04; p < 0.001) and poorer self-reported physical health (β = 1.86; p < 0.001). Poor sleep quality was significantly associated with greater IC/BPS QOL impairment (β = 0.06; p < 0.001), poorer self-reported physical health (β = -2.86; p < 0.001), and greater sexual dysfunction (β = -0.04; p < 0.05). IC/BPS nocturnal symptoms were significantly associated with greater IC/BPS impairment (β = 0.14; p < 0.001), poorer physical health (β = -2.76; p < 0.001) and mental health (β = 0.52; p < 0.01), and greater sexual dysfunction (β = -0.10; p < 0.001), after covariate adjustment. After further adjustment for IC/BPS nocturnal symptoms, we found that poor sleep quality and short sleep duration were independent correlates of poor self-reported physical health. Poor sleep quality and short sleep duration, as well as disorder-specific sleep disturbances, are highly prevalent in women with IC/BPS and are associated with poorer disease-specific and general QOL. © 2014 American Academy of Sleep Medicine.
Derivation and characterization of human embryonic stem cell lines from poor quality embryos.
Liu, Weiqiang; Yin, Yifei; Long, Xiaolin; Luo, Yumei; Jiang, Yonghua; Zhang, Wenhong; Du, Hongzi; Li, Shaoying; Zheng, Yuhong; Li, Qing; Chen, Xinjie; Liao, Baoping; Xiao, Guohong; Wang, Weihua; Sun, Xiaofang
2009-04-01
Poor quality embryos discarded from in vitro fertilization (IVF) laboratories are good sources for deriving human embryonic stem cell (hESC) lines. In this study, 166 poor quality embryos donated from IVF centers on day 3 were cultured in a blastocyst medium for 2 days, and 32 early blastocysts were further cultured in a blastocyst optimum culture medium for additional 2 days so that the inner cell masses (ICMs) could be identified and isolated easily. The ICMs of 17 blastocysts were isolated by a mechanical method, while those of the other 15 blastocysts were isolated by immunosurgery. All isolated ICMs were inoculated onto a feeder layer for subcultivation. The rates of ICM attachment, primary ICM colony formation and the efficiency of hESC derivation were similar between the ICMs isolated by the two methods (P>0.05). As a result, four new hESC lines were established. Three cell lines had normal karyotypes and one had an unbalanced Robertsonian translocation. All cell lines showed normal hESC characteristics and had the differentiation ability. In conclusion, we established a stable and effective method for hESC isolation and culture, and it was confirmed that the mechanical isolation was an effective method to isolate ICMs from poor embryos. These results further indicate that hESC lines can be derived from poor quality embryos discarded by IVF laboratories.
Mass Manufacturing Challenges For CPV Primary And Secondary Optics
NASA Astrophysics Data System (ADS)
Luce, Thomas; Cohen, Joel
2010-10-01
Crucial for the performance and longevity of CPV installations is the efficiency of the optics used. Low production cost and high performance are key for the economical success of a CPV concept. To be able to compete with existing energy sources, proven mass production methods as well as high performance materials have to be employed. The injection molding process is the ideal serial production process capable to deliver at the same time high part quantities, excellent part precision and repeatable part quality at low manufacturing cost. Primary and secondary optics require different materials to be applied. The Pros and Cons of these materials in terms of production properties and achievable part precision will be discussed. We will show quality results for primary Fresnel optics using PMMA and, alternatively Silicone on Glass. For secondary optics we will demonstrate the use of optical silicone lenses widely used for high power LED applications today. Optical grade silicone has an excellent environmental stability even when encountering high energy density levels. The experience of Eschenbach Optik in injection molding silicone optics shows that this material is a very cost competitive alternative for glass secondary optics providing both highest optical performance and precision.
Design of a multimodal fibers optic system for small animal optical imaging.
Spinelli, Antonello E; Pagliazzi, Marco; Boschi, Federico
2015-02-01
Small animals optical imaging systems are widely used in pre-clinical research to image in vivo the bio-distribution of light emitting probes using fluorescence or bioluminescence modalities. In this work we presented a set of simulated results of a novel small animal optical imaging module based on a fibers optics matrix, coupled with a position sensitive detector, devoted to acquire bioluminescence and Cerenkov images. Simulations were performed using GEANT 4 code with the GAMOS architecture using the tissue optics plugin. Results showed that it is possible to image a 30 × 30 mm region of interest using a fiber optics array containing 100 optical fibers without compromising the quality of the reconstruction. The number of fibers necessary to cover an adequate portion of a small animal is thus quite modest. This design allows integrating the module with magnetic resonance (MR) in order to acquire optical and MR images at the same time. A detailed model of the mouse anatomy, obtained by segmentation of 3D MRI images, will improve the quality of optical 3D reconstruction. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
Yang, Pei-Lin; Huang, Guey-Shiun; Tsai, Chien-Sung; Lou, Meei-Fang
2015-01-01
Poor sleep quality is a common health problem for coronary artery bypass graft patients, however few studies have evaluated sleep quality during the period immediately following hospital discharge. The aim of this study was to investigate changes in sleep quality and emotional correlates in coronary artery bypass graft patients in Taiwan at 1 week and 1 month after hospital discharge. We used a descriptive correlational design for this study. One week after discharge, 87 patients who had undergone coronary artery bypass surgery completed two structured questionnaires: the Pittsburgh Sleep Quality Index and the Hospital Anxiety and Depression Scale. Three weeks later (1 month after discharge) the patients completed the surveys again. Pearson correlations, t-tests, ANOVA and linear multiple regression analysis were used to analyze the data. A majority of the participants had poor sleep quality at 1 week (82.8%) and 1 month (66.7%) post-hospitalization, based on the global score of the Pittsburgh Sleep Quality Index. Despite poor sleep quality at both time-points the sleep quality at 1 month was significantly better than at 1-week post hospitalization. Poorer sleep quality correlated with older age, poorer heart function, anxiety and depression. The majority of participants had normal levels of anxiety at 1 week (69.0%) and 1 month (88.5%) as measured by the Hospital Anxiety and Depression Scale. However, some level of depression was seen at 1 week (78.1%) and 1 month (59.7%). Depression was a significant predictor of sleep quality at 1 week; at 1 month after hospital discharge both anxiety and depression were significant predictors of sleep quality. Sleep quality, anxiety and depression all significantly improved 1 month after hospital discharge. However, more than half of the participants continued to have poor sleep quality and some level of depression. Health care personnel should be encouraged to assess sleep and emotional status in patients after coronary artery bypass surgery and offer them appropriate management strategies to improve sleep and reduce anxiety and depression.
Yang, Pei-Lin; Huang, Guey-Shiun; Tsai, Chien-Sung; Lou, Meei-Fang
2015-01-01
Background Poor sleep quality is a common health problem for coronary artery bypass graft patients, however few studies have evaluated sleep quality during the period immediately following hospital discharge. Purpose The aim of this study was to investigate changes in sleep quality and emotional correlates in coronary artery bypass graft patients in Taiwan at 1 week and 1 month after hospital discharge. Methods We used a descriptive correlational design for this study. One week after discharge, 87 patients who had undergone coronary artery bypass surgery completed two structured questionnaires: the Pittsburgh Sleep Quality Index and the Hospital Anxiety and Depression Scale. Three weeks later (1 month after discharge) the patients completed the surveys again. Pearson correlations, t-tests, ANOVA and linear multiple regression analysis were used to analyze the data. Results A majority of the participants had poor sleep quality at 1 week (82.8%) and 1 month (66.7%) post-hospitalization, based on the global score of the Pittsburgh Sleep Quality Index. Despite poor sleep quality at both time-points the sleep quality at 1 month was significantly better than at 1-week post hospitalization. Poorer sleep quality correlated with older age, poorer heart function, anxiety and depression. The majority of participants had normal levels of anxiety at 1 week (69.0%) and 1 month (88.5%) as measured by the Hospital Anxiety and Depression Scale. However, some level of depression was seen at 1 week (78.1%) and 1 month (59.7%). Depression was a significant predictor of sleep quality at 1 week; at 1 month after hospital discharge both anxiety and depression were significant predictors of sleep quality. Conclusion Sleep quality, anxiety and depression all significantly improved 1 month after hospital discharge. However, more than half of the participants continued to have poor sleep quality and some level of depression. Health care personnel should be encouraged to assess sleep and emotional status in patients after coronary artery bypass surgery and offer them appropriate management strategies to improve sleep and reduce anxiety and depression. PMID:26291524
Socioeconomic, Family, and Pediatric Practice Factors Affecting the Level of Asthma Control
Bloomberg, Gordon R; Banister, Christina; Sterkel, Randall; Epstein, Jay; Bruns, Julie; Swerczek, Lisa; Wells, Suzanne; Yan, Yan; Garbutt, Jane M
2008-01-01
Background Multiple issues bear on effective control of childhood asthma. Objective To identify factors related to the level of asthma control in children receiving asthma care from community pediatricians. Patients and Methods Data for 362 children participating in an intervention study to reduce asthma morbidity were collected by telephone administered questionnaire. Level of asthma control (“well controlled,” partially controlled,” or “poorly controlled”) was derived from measures of recent impairment (symptoms, activity limitations, albuterol use) and the number of exacerbations in a 12 month period. Data also included demographic characteristics, asthma-related quality of life, pediatric management practices, and medication usage. Univariable and multivariable analyses were used to identify factors associated with poor asthma control and to explore the relationship between control and use of daily controller medications. Results Asthma was “well controlled” for 24% of children, “partially controlled” for 20%, and “poorly controlled” for 56%. Medicaid insurance (p=0.016), the presence of another family member with asthma (p=0.0168), and outside the home maternal employment, (p=0.025), were significant univariable factors associated with poor asthma control. Medicaid insurance had an independent association with poor control (OR 0.49, 95% CI 0.28-0.9). Seventy-six percent of children were reported by parents as receiving a daily controller medication. Comparison of guidelines recommended controller medication with level of control indicated that a higher step level of medication would have been appropriate for 74% of these children. Significantly lower overall quality of life scores were observed in both parents and children with poor control. (ANOVA, p<0.05) Conclusion Despite substantial use of daily controller medication, children with asthma continue to experience poorly controlled asthma and reduced quality of life. While Medicaid insurance and aspects of family structure are significant factors associated with poorly controlled asthma, attention to medication use and quality of life indicators may further reduce morbidity. PMID:19255010
The Longitudinal Association Between Poor Sleep Quality and Cyberbullying, Mediated by Anger.
Erreygers, Sara; Vandebosch, Heidi; Vranjes, Ivana; Baillien, Elfi; De Witte, Hans
2018-01-09
Adolescents tend to go to bed later and sleep less as they grow older, although their need for sleep stays the same throughout adolescence. Poor sleep has negative consequences on personal and interpersonal functioning, including increased aggressive tendencies. With adolescents' social life increasingly including interactions via digital media, these interactions may also become more aggressive when adolescents' sleep problems increase. One of the ways in which online aggression may be enacted is through cyberbullying. Although previous research has examined the role of sleep disruptions in offline bullying, the role of sleep in cyberbullying has not yet been addressed. Therefore, this study examines the longitudinal effect of poor sleep quality on later cyberbullying behavior. Thirteen- to fourteen-year-old adolescents completed self-report measures on sleep quality, anger, cyberbullying perpetration, and frequency of digital media use. Because one of the pathways through which sleep is proposed to be linked to aggression is an affective pathway, namely via angry affect, a mediation model of poor sleep quality predicting cyberbullying via feelings of anger was tested. Results from structural equation modeling and a bootstrap test indicated that poor sleep quality was indeed indirectly associated with later cyberbullying behavior through heightened feelings of anger, even when taking the effects of the use of digital media and previous cyberbullying behavior into account. This finding provides support for the proposed affective pathway linking sleep problems to aggression. As sleep problems and anger seem to play a predicting role in cyberbullying behavior, suggestions for cyberbullying intervention and prevention strategies are formulated.
Jeon, Hong Jin; Kim, Ji-Hae; Kim, Bin-Na; Park, Seung Jin; Fava, Maurizio; Mischoulon, David; Kang, Eun-Ho; Roh, Sungwon; Lee, Dongsoo
2014-12-01
Human error is defined as an unintended error that is attributable to humans rather than machines, and that is important to avoid to prevent accidents. We aimed to investigate the association between sleep quality and human errors among train drivers. Cross-sectional. Population-based. A sample of 5,480 subjects who were actively working as train drivers were recruited in South Korea. The participants were 4,634 drivers who completed all questionnaires (response rate 84.6%). None. The Pittsburgh Sleep Quality Index (PSQI), the Center for Epidemiologic Studies Depression Scale (CES-D), the Impact of Event Scale-Revised (IES-R), the State-Trait Anxiety Inventory (STAI), and the Korean Occupational Stress Scale (KOSS). Of 4,634 train drivers, 349 (7.5%) showed more than one human error per 5 y. Human errors were associated with poor sleep quality, higher PSQI total scores, short sleep duration at night, and longer sleep latency. Among train drivers with poor sleep quality, those who experienced severe posttraumatic stress showed a significantly higher number of human errors than those without. Multiple logistic regression analysis showed that human errors were significantly associated with poor sleep quality and posttraumatic stress, whereas there were no significant associations with depression, trait and state anxiety, and work stress after adjusting for age, sex, education years, marital status, and career duration. Poor sleep quality was found to be associated with more human errors in train drivers, especially in those who experienced severe posttraumatic stress. © 2014 Associated Professional Sleep Societies, LLC.
Del Brutto, Oscar H; Mera, Robertino M
2018-02-01
The burden of cerebral small vessel disease, sleep disorders, and chronic kidney disease is on the rise in remote rural settings. However, information on potential links between these conditions is limited. We aimed to assess the relationships between these conditions in community-dwelling older adults living in rural Ecuador. Atahualpa residents aged ≥60 years were offered a brain MRI. A venous blood sample was obtained for serum creatinine determination. Baseline interviews and procedures were directed to assess demographics, cardiovascular risk factors, and sleep quality. Using generalized structural equation modeling (GSEM), we assessed the associations between white matter hyperintensities (WMH) of vascular origin, sleep quality and kidney function, as well as the directions of the relationships between these variables. Of 423 candidates, 314 (74%) were enrolled. Moderate-to-severe WMH were noticed in 74 (24%) individuals, poor sleep quality in 101 (31%), and moderate-to-severe chronic kidney disease in 28 (9%). GSEM showed that the direction of the effect was from kidney function to WMH and from the latter to sleep quality. Of independent variables investigated, worse kidney function was associated with age, high glucose levels and male sex. WMH was associated with cholesterol blood levels, blood pressure, level of education and severe edentulism. Poor sleep quality was associated with poor physical activity. This population based study shows that chronic kidney disease is associated with increased severity of WMH, which, in turn, is associated with a poor sleep quality. Copyright © 2017 Elsevier B.V. All rights reserved.
Dragoman, Monica V; Simmons, Katharine B; Paulen, Melissa E; Curtis, Kathryn M
2017-02-01
To evaluate from the literature whether combined hormonal contraception (CHC), including combined oral contraception pills (COCs), transdermal patch, vaginal ring or combined injectables, have different effectiveness or failure rates by body weight or body mass index (BMI). We searched PubMed and the Cochrane Library databases for all articles in all languages published between inception and February 2016, for evidence relevant to body weight or BMI, CHC use and contraceptive effectiveness. The quality of each individual study was assessed using the system for evaluating evidence developed by the United States Preventive Services Task Force. From 2874 articles, we identified 15 reports for inclusion, all of fair to poor quality. Fourteen studies measured the association of obesity status and contraceptive failure among COC users. Three fair quality and one poor quality study reported increased COC failure among a heterogeneous population of overweight and obese women compared with normal weight women, while eight fair quality and two poor quality studies did not find an association. Two fair quality studies reported on contraceptive transdermal patches. One pooled analysis described a higher proportion of pregnancies among women using the patch who weighed ≥90 kg; another secondary analysis suggested BMI>30 was associated with increased failure. No studies directly compared contraceptive effectiveness using the combined vaginal ring or combined injectable. Current available evidence addressing the risk of CHC failure in obese compared to normal weight women is limited to fair and poor quality studies. Studies of COCs show mixed results, though absolute differences in COC failure by body weight and BMI are small. Based on limited evidence, it appears that increasing body weight and BMI may contribute to decreasing contraceptive patch effectiveness. Copyright © 2017. Published by Elsevier Inc.
Sanchez, Sixto E.; Martinez, Claudia; Oriol, Raphaelle A.; Yanez, David; Castañeda, Benjamín; Sanchez, Elena; Gelaye, Bizu; Williams, Michelle A.
2014-01-01
Objectives To evaluate sleep quality in relation to lifestyle characteristics including consumption of energy drinks and other caffeinated beverages among Peruvian college students. Methods A total of 2,458 college students were invited to complete a self-administered questionnaire that collected information about a variety of behaviors including consumption of energy drinks, caffeinated and alcoholic beverages. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Logistic regression procedures were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for poor sleep quality in relation to lifestyle characteristics. Results A total of 965 males and 1,493 female students were enrolled in the study. 52.0% of males and 58.4% of females experienced poor sleep quality (p=0.002). Females (OR=1.28; 95% CI 1.08–1.51) and those who reported consuming ≥ 3 stimulant beverages per week (OR=1.88; 95% CI 1.42–2.50) had higher odds of poor sleep quality. Students who consumed 1–19 alcoholic beverages monthly (OR=1.90; 95% CI 1.46–2.49) had a higher odds of long sleep latency. Consumption of ≥ 3 stimulant beverages per week was associated with daytime dysfunction due to sleep loss (OR=1.45; 95% CI 1.10–1.90), short sleep duration (OR= 1.49; 95% CI 1.14–1.94), and use of sleep medication (OR= 2.10; 95% CI 1.35–3.28). Conclusions Consumption of energy drinks, other caffeinated beverages and alcoholic beverages are risk factors of poor sleep quality. Increased awareness of these associations should promote interventions to improve students’ lifestyle habits, including consumption of alcoholic and caffeinated beverages, and overall health. PMID:25243056
Antisomnogenic cytokines, quality of life, and chronic rhinosinusitis: a pilot study.
Alt, Jeremiah A; Sautter, Nathan B; Mace, Jess C; Detwiller, Kara Y; Smith, Timothy L
2014-04-01
Sleep disturbance, reduced quality of life (QOL), and other components of "sickness behavior" in patients with chronic rhinosinusitis (CRS) are poorly understood. These complex changes in central behavior are due to the effects of immune mediators acting in the brain. We hypothesized that immune mediators that have been associated with CRS are also associated with sickness behavior, somnifacient complaints, and CRS disease-specific QOL. Pilot study. Twenty patients with CRS were prospectively enrolled and completed the Pittsburgh Sleep Quality Index (PSQI), disease-specific QOL, and olfactory instruments. Ethmoid mucosa was obtained and reverse transcription-polymerase chain reaction was performed for the cytokines interleukin (IL)-4, -13, and transforming growth factor-β (TGF-β). Average change in crossover threshold was calculated, and differences in gene expression were correlated with sleep quality, CRS-specific QOL, and disease severity. Patients with CRS reported overall poor sleep quality and poor CRS-specific QOL with significant correlations between them. Increased expression of TGF-β (r = -0.443; P = .050) and IL-4 (r = -0.548; P = .012) correlated with sleep dysfunction, whereas IL-13 expression was linearly associated with worse sleep quality (PSQI scores r = -0.417; P = .075). IL-4 and TGF-β expression was not associated with CRS disease severity or QOL, whereas significantly higher levels of IL-13 expression correlated with worse CRS disease severity and QOL. Patients with CRS exhibited behavioral changes commonly referred to as sickness behavior, which include poor sleep quality and reduced QOL. The upregulation of IL-4 and TGF-β may contribute to inflammatory brain-mediated effects on sleep quality, whereas IL-13 may be a pleiotropic signaling molecule influencing sleep, QOL, and CRS disease severity. 2b. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.
Familiality and clinical outcomes of sleep disturbances in major depressive and bipolar disorders.
Lai, Yin-Chieh; Huang, Ming-Chyi; Chen, Hsi-Chung; Lu, Ming-Kun; Chiu, Yi-Hang; Shen, Winston W; Lu, Ru-Band; Kuo, Po-Hsiu
2014-01-01
Sleep disturbances are frequently observed in major depressive (MDD) and bipolar disorder (BD). This study reported sleep profiles of patients and their relatives versus controls, and examined the familiality of sleep features in mood disorder families. We also evaluated the influences of sleep disturbance on patients' quality of life (QOL), functional impairment, and suicidality. We recruited 363 BD and 157 MDD patients, 521 first-degree relatives, and 235 healthy controls, which completed a diagnostic interview, Pittsburgh Sleep Quality Index (PSQI), and QOL questionnaire. The magnitude of heritability of sleep features was calculated and familiality was evaluated by mixed regression models and intraclass correlation coefficient (ICC). The associations between sleep problems and clinical outcomes were examined using multiple regression models. More than three-quarters of mildly-ill patients were classified as "poor sleepers". MDD patients had significantly worse sleep quality as compared to BD patients. Moderate but significant familial aggregation was observed in subjective sleep quality, sleep latency, disturbance, daytime dysfunction, and global score (ICC=0.10-0.21, P<.05). Significant heritability was found in sleep quality (0.45, P<.001) and sleep disturbance (0.23, P<.001). Patients with good sleep quality had better QOL and less functional impairment (P<.05) than poor sleepers. Poor sleep quality and nightmares further increased the risk for suicidal ideation (ORadj=2.8) and suicide attempts (ORadj=1.9-2.8). Subjectively measured sleep features demonstrated significant familiality. Poor sleep quality further impaired patients' daily function and QOL, in addition to increasing the risk of suicidality, and thus requires special attention in related clinical settings. Copyright © 2013 Elsevier Inc. All rights reserved.
Image quality testing of assembled IR camera modules
NASA Astrophysics Data System (ADS)
Winters, Daniel; Erichsen, Patrik
2013-10-01
Infrared (IR) camera modules for the LWIR (8-12_m) that combine IR imaging optics with microbolometer focal plane array (FPA) sensors with readout electronics are becoming more and more a mass market product. At the same time, steady improvements in sensor resolution in the higher priced markets raise the requirement for imaging performance of objectives and the proper alignment between objective and FPA. This puts pressure on camera manufacturers and system integrators to assess the image quality of finished camera modules in a cost-efficient and automated way for quality control or during end-of-line testing. In this paper we present recent development work done in the field of image quality testing of IR camera modules. This technology provides a wealth of additional information in contrast to the more traditional test methods like minimum resolvable temperature difference (MRTD) which give only a subjective overall test result. Parameters that can be measured are image quality via the modulation transfer function (MTF) for broadband or with various bandpass filters on- and off-axis and optical parameters like e.g. effective focal length (EFL) and distortion. If the camera module allows for refocusing the optics, additional parameters like best focus plane, image plane tilt, auto-focus quality, chief ray angle etc. can be characterized. Additionally, the homogeneity and response of the sensor with the optics can be characterized in order to calculate the appropriate tables for non-uniformity correction (NUC). The technology can also be used to control active alignment methods during mechanical assembly of optics to high resolution sensors. Other important points that are discussed are the flexibility of the technology to test IR modules with different form factors, electrical interfaces and last but not least the suitability for fully automated measurements in mass production.
Method for quantifying optical properties of the human lens
Loree, deceased, Thomas R.; Bigio, Irving J.; Zuclich, Joseph A.; Shimada, Tsutomu; Strobl, Karlheinz
1999-01-01
Method for quantifying optical properties of the human lens. The present invention includes the application of fiberoptic, OMA-based instrumentation as an in vivo diagnostic tool for the human ocular lens. Rapid, noninvasive and comprehensive assessment of the optical characteristics of a lens using very modest levels of exciting light are described. Typically, the backscatter and fluorescence spectra (from about 300- to 900-nm) elicited by each of several exciting wavelengths (from about 300- to 600-nm) are collected within a few seconds. The resulting optical signature of individual lenses is then used to assess the overall optical quality of the lens by comparing the results with a database of similar measurements obtained from a reference set of normal human lenses having various ages. Several metrics have been identified which gauge the optical quality of a given lens relative to the norm for the subject's chronological age. These metrics may also serve to document accelerated optical aging and/or as early indicators of cataract or other disease processes.
Method for quantifying optical properties of the human lens
Loree, T.R.; Bigio, I.J.; Zuclich, J.A.; Shimada, Tsutomu; Strobl, K.
1999-04-13
A method is disclosed for quantifying optical properties of the human lens. The present invention includes the application of fiberoptic, OMA-based instrumentation as an in vivo diagnostic tool for the human ocular lens. Rapid, noninvasive and comprehensive assessment of the optical characteristics of a lens using very modest levels of exciting light are described. Typically, the backscatter and fluorescence spectra (from about 300- to 900-nm) elicited by each of several exciting wavelengths (from about 300- to 600-nm) are collected within a few seconds. The resulting optical signature of individual lenses is then used to assess the overall optical quality of the lens by comparing the results with a database of similar measurements obtained from a reference set of normal human lenses having various ages. Several metrics have been identified which gauge the optical quality of a given lens relative to the norm for the subject`s chronological age. These metrics may also serve to document accelerated optical aging and/or as early indicators of cataract or other disease processes. 8 figs.
Searching for intermediate-mass black holes in extremely-metal poor galaxies
NASA Astrophysics Data System (ADS)
Mezcua, Mar
2016-09-01
Extremely metal-poor dwarf galaxies (XMPs) are star-forming, low-mass galaxies with metallicites highly sub-solar. Their regions of star formation could be triggered by the accretion of pristine gas from the cosmic web and harbour Population III stars. XMPs are thus ideal laboratories for searching for the seed black holes or intermediate-mass black holes (IMBHs) that populated the early Universe. The combination of X-ray, radio and optical observations offer the best tool for detecting such IMBHs in the local Universe. We propose Chandra observations of a sample of XMPs whose optical spectra indicate the possible presence of an active black hole of 1e4 - 1e6 Msun. The Chandra data could confirm this and yield the first detection of an IMBH in these type of galaxies.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lu, Xiaonan; Schreiber, Daniel K.; Neeway, James J.
Atom probe tomography (APT) is a novel analytical microscopy method that provides three dimensional elemental mapping with sub-nanometer spatial resolution and has only recently been applied to insulating glass and ceramic samples. In this paper, we have studied the influence of the optical absorption in glass samples on APT characterization by introducing different transition metal optical dopants to a model borosilicate nuclear waste glass (international simple glass). A systematic comparison is presented of the glass optical properties and the resulting APT data quality in terms of compositional accuracy and the mass spectra quality for two APT systems: one with amore » green laser (532 nm, LEAP 3000X HR) and one with a UV laser (355 nm, LEAP 4000X HR). These data were also compared to the study of a more complex borosilicate glass (SON68). The results show that the analysis data quality such as compositional accuracy and total ions collected, was clearly linked to optical absorption when using a green laser, while for the UV laser optical doping aided in improving data yield but did not have a significant effect on compositional accuracy. Comparisons of data between the LEAP systems suggest that the smaller laser spot size of the LEAP 4000X HR played a more critical role for optimum performance than the optical dopants themselves. The smaller spot size resulted in more accurate composition measurements due to a reduced background level independent of the material’s optical properties.« less
Stochastic analysis of 1D and 2D surface topography of x-ray mirrors
NASA Astrophysics Data System (ADS)
Tyurina, Anastasia Y.; Tyurin, Yury N.; Yashchuk, Valeriy V.
2017-08-01
The design and evaluation of the expected performance of new optical systems requires sophisticated and reliable information about the surface topography for planned optical elements before they are fabricated. The problem is especially complex in the case of x-ray optics, particularly for the X-ray Surveyor under development and other missions. Modern x-ray source facilities are reliant upon the availability of optics with unprecedented quality (surface slope accuracy < 0.1μrad). The high angular resolution and throughput of future x-ray space observatories requires hundreds of square meters of high quality optics. The uniqueness of the optics and limited number of proficient vendors makes the fabrication extremely time consuming and expensive, mostly due to the limitations in accuracy and measurement rate of metrology used in fabrication. We discuss improvements in metrology efficiency via comprehensive statistical analysis of a compact volume of metrology data. The data is considered stochastic and a new statistical model called Invertible Time Invariant Linear Filter (InTILF) is developed now for 2D surface profiles to provide compact description of the 2D data additionally to 1D data treated so far. The model captures faint patterns in the data and serves as a quality metric and feedback to polishing processes, avoiding high resolution metrology measurements over the entire optical surface. The modeling, implemented in our Beatmark software, allows simulating metrology data for optics made by the same vendor and technology. The forecast data is vital for reliable specification for optical fabrication, to be exactly adequate for the required system performance.
Sleep Disturbances among Persons Who Are Visually Impaired: Survey of Dog Guide Users.
ERIC Educational Resources Information Center
Fouladi, Massoud K.; Moseley, Merrick J.; Jones, Helen S.; Tobin, Michael J.
1998-01-01
A survey completed by 1237 adults with severe visual impairments found that 20% described the quality of their sleep as poor or very poor. Exercise was associated with better sleep and depression with poorer sleep. However, visual acuity did not predict sleep quality, casting doubt on the idea that restricted visual input (light) causes sleep…
Hydrology and Water Quality of Forested Lands in Eastern North Carolina
George M. Chescheir; M.E. Lebo; Devendra M. Amatya; J. Hughes; J.W. Gilliam; R. Wayne Skaggs; R.B. Hermann
2003-01-01
More than 100 site years of hydrology and water quality data spanning 25 years (1976-2000) were compiled from research and monitoring studies on forest stands with natural vegetation and tracts managed for timber production. A total of 41 watersheds located on poorly drained to very poorly drained soils on flat divides between coastal streams were included ranging in...
Selvi, Yavuz; Boysan, Murat; Kandeger, Ali; Uygur, Omer F; Sayin, Ayca A; Akbaba, Nursel; Koc, Basak
2018-08-01
The current study aimed at investigating the latent dimensional structure of sleep quality as indexed by the seven components of the Pittsburgh Sleep Quality Index (PSQI), as well as latent covariance structure between sleep quality, circadian preferences and depressive symptoms. Two hundred twenty-five patients with major depressive disorder (MDD), with an average age of 29.92 ± 10.49 years (aged between 17 and 63), participated in the study. The PSQI, Morningness-Eveningness Questionnaire (MEQ) and Beck Depression Inventory (BDI) were administered to participants. Four sets of latent class analyses were subsequently run to obtain optimal number of latent classes best fit to the data. Mixture models revealed that sleep quality is multifaceted in MDD. The data best fit to four-latent-class model: Poor Habitual Sleep Quality (PHSQ), Poor Subjective Sleep Quality (PSSQ), Intermediate Sleep Quality (ISQ), and Good Sleep Quality (GSQ). MDD patients classified into GSQ latent class (23.6%) reported the lowest depressive symptoms and were more prone to morningness diurnal preferences compared to other three homogenous sub-groups. Finally, the significant association between eveningness diurnal preferences and depressive symptomatology was significantly mediated by poor sleep quality. The cross-sectional nature of the study and the lack of an objective measurement of sleep such as polysomnography recordings was the most striking limitation of the study. We concluded sleep quality in relation to circadian preferences and depressive symptoms has a heterogeneous nature in MDD. Copyright © 2018. Published by Elsevier B.V.
Tataw, David Besong
2011-05-01
The author's purpose through this study was to document and analyze health provider perceptions of their social work environment and the state of pediatric care at Los Angeles County King/Drew Hospital and Medical Center in 2000, after the restructuring and downsizing of the hospital and its community clinics. The research results showed nurses and physicians reporting that both the quality of pediatric care and the provider social work environment were poor. Negative factors in the social work environment included: low employee morale, poorly staffed clinical teams, lack of professional autonomy, perceptions of low quality of care for pediatric patients, and interpersonal issues of poor communication and collaboration among providers. Providers also perceived a non-supportive work environment, sense of powerlessness, poor quality of work, lack of goal clarity from leadership, lack of fairness in leadership behavior, and an organizational leadership that is abandoning its core mission and values, thereby making it difficult for providers to carry out their professional functions. The author's findings in this study suggest a relationship between intra-role conflict, social employment environment and quality of care at King/Drew Medical Center in 2000. Lessons for practice are presented.
Nowakowski, Maciej; Sheehan, Matthew; Neal, Daniel; Goncharov, Alexander V.
2012-01-01
Conventional optical systems usually provide best image quality on axis, while showing unavoidable gradual decrease in image quality towards the periphery of the field. The optical system of the human eye is not an exception. Within a limiting boundary the image quality can be considered invariant with field angle, and this region is known as the isoplanatic patch. We investigate the isoplanatic patch of eight healthy eyes and measure the wavefront aberration along the pupillary axis compared to the line of sight. The results are used to discuss methods of ocular aberration correction in wide-field retinal imaging with particular application to multi-conjugate adaptive optics systems. PMID:22312578
Securing quality of camera-based biomedical optics
NASA Astrophysics Data System (ADS)
Guse, Frank; Kasper, Axel; Zinter, Bob
2009-02-01
As sophisticated optical imaging technologies move into clinical applications, manufacturers need to guarantee their products meet required performance criteria over long lifetimes and in very different environmental conditions. A consistent quality management marks critical components features derived from end-users requirements in a top-down approach. Careful risk analysis in the design phase defines the sample sizes for production tests, whereas first article inspection assures the reliability of the production processes. We demonstrate the application of these basic quality principles to camera-based biomedical optics for a variety of examples including molecular diagnostics, dental imaging, ophthalmology and digital radiography, covering a wide range of CCD/CMOS chip sizes and resolutions. Novel concepts in fluorescence detection and structured illumination are also highlighted.
Facial and bodily correlates of family background.
Boothroyd, Lynda G; Perrett, David I
2006-09-22
It has been suggested that absence of the father during early childhood has long-reaching effects on reproductive strategy and development of offspring. This paper reports two studies designed to investigate the physical characteristics of daughters associated with father absence. Study 1 used a facial averaging method to produce composite images of faces of women whose parents separated during their childhood (who were 'father absent'), women whose parents remained together, but had poor quality relationships and women whose parents were together and had good quality relationships. Images were then rated by male and female judges. Father absence and poor parental relationships were associated with apparent facial masculinity and reduced attractiveness in daughters. Poor parental relationships were also associated with reduced apparent health. Study 2 compared family background with body measurements and found that father absence or a poor quality relationship between parents were associated with body masculinity (high waist-to-hip ratio) and increased weight-for-height and adiposity. These results highlight the possibility of physical masculinization being associated with purported father absence 'effects'.
Application of psychometric theory to the measurement of voice quality using rating scales.
Shrivastav, Rahul; Sapienza, Christine M; Nandur, Vuday
2005-04-01
Rating scales are commonly used to study voice quality. However, recent research has demonstrated that perceptual measures of voice quality obtained using rating scales suffer from poor interjudge agreement and reliability, especially in the mid-range of the scale. These findings, along with those obtained using multidimensional scaling (MDS), have been interpreted to show that listeners perceive voice quality in an idiosyncratic manner. Based on psychometric theory, the present research explored an alternative explanation for the poor interlistener agreement observed in previous research. This approach suggests that poor agreement between listeners may result, in part, from measurement errors related to a variety of factors rather than true differences in the perception of voice quality. In this study, 10 listeners rated breathiness for 27 vowel stimuli using a 5-point rating scale. Each stimulus was presented to the listeners 10 times in random order. Interlistener agreement and reliability were calculated from these ratings. Agreement and reliability were observed to improve when multiple ratings of each stimulus from each listener were averaged and when standardized scores were used instead of absolute ratings. The probability of exact agreement was found to be approximately .9 when using averaged ratings and standardized scores. In contrast, the probability of exact agreement was only .4 when a single rating from each listener was used to measure agreement. These findings support the hypothesis that poor agreement reported in past research partly arises from errors in measurement rather than individual differences in the perception of voice quality.
Paediatric cerebrovascular CT angiography-towards better image quality.
Thust, Stefanie C; Chong, Wui Khean Kling; Gunny, Roxana; Mazumder, Asif; Poitelea, Marius; Welsh, Anna; Ederies, Ash; Mankad, Kshitij
2014-12-01
Paediatric cerebrovascular CT angiography (CTA) can be challenging to perform due to variable cardiovascular physiology between different age groups and the risk of movement artefact. This analysis aimed to determine what proportion of CTA at our institution was of diagnostic quality and identify technical factors which could be improved. a retrospective analysis of 20 cases was performed at a national paediatric neurovascular centre assessing image quality with a subjective scoring system and Hounsfield Unit (HU) measurements. Demographic data, contrast dose, flow rate and triggering times were recorded for each patient. Using a qualitative scoring system, 75% of studies were found to be of diagnostic quality (n=9 'good', n=6 'satisfactory') and 25% (n=5) were 'poor'. Those judged subjectively to be poor had arterial contrast density measured at less than 250 HU. Increased arterial opacification was achieved for cases performed with an increased flow rate (2.5-4 mL/s) and higher intravenous contrast dose (2 mL/kg). Triggering was found to be well timed in nine cases, early in four cases and late in seven cases. Of the scans triggered early, 75% were poor. Of the scans triggered late, less (29%) were poor. High flow rates (>2.5 mL/s) were a key factor for achieving high quality paediatric cerebrovascular CTA imaging. However, appropriate triggering by starting the scan immediately on contrast opacification of the monitoring vessel plays an important role and could maintain image quality when flow rates were lower. Early triggering appeared more detrimental than late.
The Effects of Poor Sleep Quality on Cognitive Function of Patients with Cirrhosis
Stewart, Charmaine A.; Auger, Robert; Enders, Felicity T. B.; Felmlee-Devine, Donna; Smith, Glenn E.
2014-01-01
Objectives: This study was conducted to assess the ill-defined relationship between sleep quality and multiple, specific domains of cognitive function in patients with cirrhosis. Methods: A comprehensive battery of neuropsychological tests (divided into six neurocognitive domains) and a standardized, validated measure of sleep quality (Pittsburgh Sleep Quality Index [PSQI]) were administered to patients with cirrhosis and without evidence of overt hepatic encephalopathy, recruited from liver transplant and advanced liver disease clinics (n = 34). An inflammatory bowel disease (IBD) control group (n = 23) was similarly recruited and evaluated to control for the secondary effect of a chronic illness on cognition. PSQI global and component scores were used to predict cognitive function in each neurocognitive domain, using linear regression Results: Global PSQI scores were significantly higher (indicating poorer sleep quality) in the cirrhosis group (median [range] = 10 [1-19]) than in IBD controls = 5 (1-14); p = 0.002). After controlling for age and education, short duration of sleep was associated with impaired memory for patients with cirrhosis; the use of soporific agents was associated with poor visual-perceptual function in patients with IBD. Conclusions: Poor sleep was associated with worsening of the already impaired cognitive function of patients with cirrhosis. Citation: Stewart CA; Auger R; Enders FTB; Felmlee-Devine D; Smith GE. The effects of poor sleep quality on cognitive function of patients with cirrhosis. J Clin Sleep Med 2014;10(1):21-26. PMID:24426816
The Web: Can We Make It Easier To Find Information?
ERIC Educational Resources Information Center
Maddux, Cleborne D.
1999-01-01
Reviews problems with the World Wide Web that can be attributed to human error or ineptitude, and provides suggestions for improvement. Discusses poor Web design, poor use of search engines, and poor quality control by search engines and directories. (AEF)
Dichromated-gelatin hologram process for improved optical quality
NASA Technical Reports Server (NTRS)
Stewart, W. C.
1975-01-01
Optical distortions are eliminated by use of wetting agency followed by sequential immersion in several alcohol-water baths of increasing alcohol concentration. Dehydration proceeds uniformly over surface of gelatin. Dried plate is free of optically-distorting thickness variations.
NASA Astrophysics Data System (ADS)
Kotb, Amer
2015-06-01
The modeling of all-optical logic XNOR gate is realized by a series combination of XOR and INVERT gates. This Boolean function is simulated by using Mach-Zehnder interferometers (MZIs) utilizing quantum-dots semiconductor optical amplifiers (QDs-SOAs). The study is carried out when the effect of amplified spontaneous emission (ASE) is included. The dependence of the output quality factor ( Q-factor) on signals and QDs-SOAs' parameters is also investigated and discussed. The simulation is conducted under a repetition rate of ˜1 Tb/s.
Liljas, A E M; Wannamethee, S G; Whincup, P H; Papacosta, O; Walters, K; Iliffe, S; Lennon, L T; Carvalho, L A; Ramsay, S E
2016-06-01
Hearing and vision problems are common in older adults. We investigated the association of self-reported sensory impairment with lifestyle factors, chronic conditions, physical functioning, quality of life and social interaction. A population-based cross-sectional study of participants of the British Regional Heart Study aged 63-85 years. A total of 3981 men (82% response rate) provided data. Twenty-seven per cent (n = 1074) reported hearing impairment including being able to hear with aid (n = 482), being unable to hear (no aid) (n = 424) and being unable to hear despite aid (n = 168). Three per cent (n = 124) reported vision impairment. Not being able to hear, irrespective of use of hearing aid, was associated with poor quality of life, poor social interaction and poor physical functioning. Men who could not hear despite hearing aid were more likely to report coronary heart disease (CHD) [age-adjusted odds ratios (ORs) 1.89 (95% confidence interval 1.36-2.63)]. Vision impairment was associated with symptoms of CHD including breathlessness [OR 2.06 (1.38-3.06)] and chest pain [OR 1.58 (1.07-2.35)]. Vision impairment was also associated with poor quality of life, poor social interaction and poor physical functioning. Sensory impairment is associated with poor physical functioning, poor health and poor social interaction in older men. Further research is warranted on pathways underlying these associations. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Human Stereopsis is not Limited by the Optics of the Well-focused Eye
Vlaskamp, Björn N.S.; Yoon, Geunyoung; Banks, Martin S.
2011-01-01
Human stereopsis—the perception of depth from differences in the two eyes’ images—is very precise: Image differences smaller than a single photoreceptor can be converted into a perceived difference in depth. To better understand what determines this precision, we examined how the eyes’ optics affects stereo resolution. We did this by comparing performance with normal, well-focused optics and with optics improved by eliminating chromatic aberration and correcting higher-order aberrations. We first measured luminance contrast sensitivity in both eyes and showed that we had indeed improved optical quality significantly. We then measured stereo resolution in two ways: by finding the finest corrugation in depth that one can perceive, and by finding the smallest disparity one can perceive as different from zero. Our optical manipulation had no effect on stereo performance. We checked this by redoing the experiments at low contrast and again found no effect of improving optical quality. Thus, the resolution of human stereopsis is not limited by the optics of the well-focused eye. We discuss the implications of this remarkable finding. PMID:21734272
Forget, Benoît-Claude; Ramaz, François; Atlan, Michaël; Selb, Juliette; Boccara, Albert-Claude
2003-03-01
We report new results on acousto-optical tomography in phantom tissues using a frequency chirp modulation and a CCD camera. This technique allows quick recording of three-dimensional images of the optical contrast with a two-dimensional scan of the ultrasound source in a plane perpendicular to the ultrasonic path. The entire optical contrast along the ultrasonic path is concurrently obtained from the capture of a film sequence at a rate of 200 Hz. This technique reduces the acquisition time, and it enhances the axial resolution and thus the contrast, which are usually poor owing to the large volume of interaction of the ultrasound perturbation.
Insomnia, Sleep Quality, and Quality of Life in Mild to Moderate Parkinson's Disease.
Shafazand, Shirin; Wallace, Douglas M; Arheart, Kristopher L; Vargas, Silvia; Luca, Corneliu C; Moore, Henry; Katzen, Heather; Levin, Bonnie; Singer, Carlos
2017-03-01
Sleep disorders are prevalent in Parkinson's disease but underreported in clinical settings. The contribution of sleep disorders to health-related quality of life (HRQOL) for patients with this degenerative neurological disease are not well known. To evaluate the impact of insomnia symptoms, obstructive sleep apnea (OSA), and poor sleep quality on HRQOL in a cohort of patients with idiopathic Parkinson's disease. We enrolled a convenience sample of 66 adults seen in the University of Miami Movement Disorders Clinic between July 2011 and June 2013. Participants completed validated questionnaires to determine insomnia symptoms, OSA risk, depression, anxiety, and HRQOL. All patients underwent unattended polysomnography to confirm OSA. Results were compared for those with and without insomnia symptoms. Principal component and regression analyses were performed to evaluate determinants of HRQOL. Participants were predominately Hispanic males with mild to moderate Parkinson's disease. Insomnia symptoms were reported for 46% of the study subjects. OSA (apnea-hypopnea index, ≥5) was noted in 47%, with a mean apnea-hypopnea index of 8.3 ± 11.0. Fairly bad to very bad sleep quality was reported by 21% of the participants. Insomnia (r = 0.71; P < 0.001), daytime sleepiness (r = 0.36; P = 0.003), depression symptoms (r = 0.44; P < 0.001), and anxiety symptoms (r = 0.33; P = 0.006) were significant correlates of poor sleep quality. OSA, severity of Parkinson's disease, and dopaminergic therapy were not. In the principal component analysis, sleep quality was a significant component of the "psychological factor" that in turn was a significant determinant of overall HRQOL. Insomnia symptoms, OSA, and subsequent poor sleep quality are prevalent in Parkinson's disease. In this single-center, exploratory study, we found that insomnia and poor sleep quality, but not OSA, play important roles in determining overall quality of life for patients with this disease. Clinical trial registered with www.clinicaltrials.gov (NCT02034357).
Robinson, Bret A.
2004-01-01
Biotic indices (indicators of water-quality conditions) were calculated from the macroinvertebrate data. Ephemeroptera, Plecoptera, Trichoptera Richness Index values calculated for 23 samples collected from 16 sites ranged from 5 to 15, with more than 75 percent of the values falling within the range of 7 to 11. Hilsenhoff Biotic Index scores and Invertebrate Community Index scores calculated for samples collected at three sites indicate that water quality at these sites ranged from good to poor. The one site with a poor water-quality index score had a small drainage area. The small drainage area and dry conditions during the sampling period may have contributed to the poor scores calculated for this site.
NASA Astrophysics Data System (ADS)
Lysaght, Patrick S.; Ybarra, Israel; Sax, Harry; Gupta, Gaurav; West, Michael; Doros, Theodore G.; Beach, James V.; Mello, Jim
2000-06-01
The continued growth of the semiconductor manufacturing industry has been due, in large part, to improved lithographic resolution and overlay across increasingly larger chip areas. Optical lithography continues to be the mainstream technology for the industry with extensions of optical lithography being employed to support 180 nm product and process development. While the industry momentum is behind optical extensions to 130 nm, the key challenge will be maintaining an adequate and affordable process latitude (depth of focus/exposure window) necessary for 10% post-etch critical dimension (CD) control. If the full potential of optical lithography is to be exploited, the current lithographic systems can not be compromised by incoming wafer quality. Impurity specifications of novel Low-k dielectric materials, plating solutions, chemical-mechanical planarization (CMP) slurries, and chemical vapor deposition (CVD) precursors are not well understood and more stringent control measures will be required to meet defect density targets as identified in the National Technology Roadmap for Semiconductors (NTRS). This paper identifies several specific poor quality wafer issues that have been effectively addressed as a result of the introduction of a set of flexible and reliable wafer back surface clean processes developed on the SEZ Spin-Processor 203 configured for processing of 200 mm diameter wafers. Patterned wafers have been back surface etched by means of a novel spin process contamination elimination (SpCE) technique with the wafer suspended by a dynamic nitrogen (N2) flow, device side down, via the Bernoulli effect. Figure 1 illustrates the wafer-chuck orientation within the process chamber during back side etch processing. This paper addresses a number of direct and immediate benefits to the MicraScan IIITM deep-ultraviolet (DUV) step-and-scan system at SEMATECH. These enhancements have resulted from the resolution of three significant problems: (1) back surface particle/residual contamination, (2) wafer flatness, and (3) control of contaminant materials such as copper (Cu). Data associated with the SpCE process, optimized for flatness improvement, particle removal, and Cu contamination control is presented in this paper, as it relates to excessive consumption of the usable depth of focus (UDOF) and comprehensive yield enhancement in photolithography. Additionally, data illustrating a highly effective means of eliminating copper from the wafer backside, bevel/edge, and frontside edge exclusion zone (0.5 mm - 3 mm), is presented. The data, obtained within the framework of standard and experimental copper/low-k device production at SEMATECH, quantifies the benefits of implementing the SEZ SpCE clean operation. Furthermore, this data confirms the feasibility of utilizing existing (non-copper) process equipment in conjunction with the development of copper applications by verifying the reliability and cost effectiveness of SpCE functionality.
Large optics for the National Ignition Facility
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baisden, P.
2015-01-12
The National Ignition Facility (NIF) laser with its 192 independent laser beams is not only the world’s largest laser, it is also the largest optical system ever built. With its 192 independent laser beams, the NIF requires a total of 7648 large-aperture (meter-sized) optics. One of the many challenges in designing and building NIF has been to carry out the research and development on optical materials, optics design, and optics manufacturing and metrology technologies needed to achieve NIF’s high output energies and precision beam quality. This paper describes the multiyear, multi-supplier, development effort that was undertaken to develop the advancedmore » optical materials, coatings, fabrication technologies, and associated process improvements necessary to manufacture the wide range of NIF optics. The optics include neodymium-doped phosphate glass laser amplifiers; fused silica lenses, windows, and phase plates; mirrors and polarizers with multi-layer, high-reflectivity dielectric coatings deposited on BK7 substrates; and potassium di-hydrogen phosphate crystal optics for fast optical switches, frequency conversion, and polarization rotation. Also included is a discussion of optical specifications and custom metrology and quality-assurance tools designed, built, and fielded at supplier sites to verify compliance with the stringent NIF specifications. In addition, a brief description of the ongoing program to improve the operational lifetime (i.e., damage resistance) of optics exposed to high fluence in the 351-nm (3ω) is provided.« less
de Vasconcelos, Hérica Cristina Alves; Fragoso, Luciana Vládia Carvalhêdo; Marinho, Niciane Bandeira Pessoa; de Araújo, Márcio Flávio Moura; de Freitas, Roberto Wagner Júnior Freire; Zanetti, Maria Lúcia; Damasceno, Marta Maria Coelho
2013-08-01
The current study investigated the correlation between anthropometric indicators and sleep quality among Brazilian university students using the Pittsburgh Sleep Quality Index. A cross-sectional assessment with 702 university students was conducted between March 2010 and June 2011. Results showed that cases of obesity were more frequent among students who were good sleepers. On the other hand, overweight and high cervical and abdominal circumference was most prominent among poor sleepers. Thus, apart from the damage caused by sleep disorders alone, additional risks due to the association between poor sleep quality and being overweight, central obesity, and increased cervical perimeter are highlighted.
Izugbara, Chimaraoke O; Wekesah, Frederick
2018-01-01
Abstract User priorities regarding quality care in contexts of medical pluralism are poorly documented. Drawing on group and individual interviews with women, we interrogate ideas of quality maternity care in the context of Nigeria’s medical pluralism. We found complex utilization patterns for conventional, complementary and alternative maternity care services as well as ideas of quality maternity care that stress effective coordination and integration of different typologies of maternity health services; socially sensitive and truthful providers; and socioeconomic, physical and parochial forms of safety. Informal providers were the commonly reported source of maternal health services in the study. Maternal health services in the country were also generally viewed as poor quality, characterized by pervasive abuse, quackery and lack of commitment to the needs and sensitivities of women. Convenience, availability and affordability of maternal health services, as well as sociocultural factors were major influences on women’s use of services. Results demonstrate the embeddedness of women’s quality of care notions in the vast socioeconomic inequities that typify Nigeria’s particular form of poorly regulated medical pluralism, raising need for strategies to strengthen the delivery, coordination and supervision of maternal health services in the country. PMID:29036530
Escamilla, Veronica; Calhoun, Lisa; Winston, Jennifer; Speizer, Ilene S
2018-02-01
Universal access to health care requires service availability and accessibility for those most in need of maternal and child health services. Women often bypass facilities closest to home due to poor quality. Few studies have directly linked individuals to facilities where they sought maternal and child health services and examined the role of distance and quality on this facility choice. Using endline data from a longitudinal survey from a sample of women in five cities in Kenya, we examine the role of distance and quality on facility selection for women using delivery, facility-based contraceptives, and child health services. A survey of public and private facilities offering reproductive health services was also conducted. Distances were measured between household cluster location and both the nearest facility and facility where women sought care. A quality index score representing facility infrastructure, staff, and supply characteristics was assigned to each facility. We use descriptive statistics to compare distance and quality between the nearest available facility and visited facility among women who bypassed the nearest facility. Facility distance and quality comparisons were also stratified by poverty status. Logistic regression models were used to measure associations between the quality and distance to the nearest facility and bypassing for each outcome. The majority of women bypassed the nearest facility regardless of service sought. Women bypassing for delivery traveled the furthest and had the fewest facility options near their residential cluster. Poor women bypassing for delivery traveled 4.5 km further than non-poor women. Among women who bypassed, two thirds seeking delivery and approximately 46% seeking facility-based contraception or child health services bypassed to a public hospital. Both poor and non-poor women bypassed to higher quality facilities. Our findings suggest that women in five cities in Kenya prefer public hospitals and are willing to travel further to obtain services at public hospitals, possibly related to free service availability. Over time, it will be important to examine service quality and availability in public sector facilities with reduced or eliminated user fees, and whether it lends itself to a continuum of care where women can visit one facility for multiple services reducing travel burden.
[Interaction between quality and duration of sleep on the prevalence of type 2 diabetes].
Zhang, Pan; Lou, Peian; Chang, Guiqiu; Zhang, Lei; Chen, Peipei; Li, Ting; Qiao, Cheng; Dong, Zongmei
2014-09-01
To explore the effects related to quality and duration of sleep and their interactions on the prevalence of type-2 diabetes (T2DM). 9 622 people aged 18 years and over were recruited for our cross-sectional study during March 2013 to May 2013. Unconditional logistic regression was used to analyze the relationship between quality and duration of sleep on T2DM. Bootstrap was used to calculate the relative excess risk of interaction (RERI), the attributable proportion (AP) of interaction and the synergy index (SI). 95% confidence intervals (CI) of RERI, AP and SI were estimated. Concerning the comparison between cases and controls on both individual and total scores, other scores were all significantly different (P < 0.01), except for two items (time for falling asleep and drugs for hypnosis). The prevalence of T2DM in volunteers with poor sleeping quality was higher than that in volunteers with good sleeping quality (P < 0.01). Individuals with sleep duration <6 hours had a higher prevalence of T2DM, when compared with individuals with sleep duration of 6-8 hours (P < 0.01). After adjusting for age, gender, level of education, occupation, family history of diabetes, status on cigarette smoking, alcohol intake, physical activities and body mass index (BMI), the prevalence of T2DM appeared the highest in those with poor sleeping quality and short duration (OR = 4.78, 95% CI:3.32-6.99; P < 0.01), when compared with those who had good sleep quality and 6-8 h sleep duration. The risk of T2DM still increased in people who had poor sleep or long duration (OR = 1.92, 95% CI:1.18-3.31; P < 0.01). Values of RERI, AP and SI (with 95% CI) were 2.33 (1.23-8.79), 0.67(0.21-0.83) and 6.87 (2.33-10.75), respectively, for the interaction between poor sleep quality and short sleep duration, while 0.33 (-0.12-1.13), 0.17 (-0.03-0.51), 1.56 (0.76-2.74) for the interaction between good sleep quality and long sleep duration. Our results suggested that there were additive interactions between poor quality and shorter duration of sleep.
A Nationwide Survey of the Quality of Antimalarials in Retail Outlets in Tanzania
Kaur, Harparkash; Goodman, Catherine; Thompson, Eloise; Thompson, Katy-Anne; Masanja, Irene; Kachur, S. Patrick; Abdulla, Salim
2008-01-01
Introduction Retail pharmaceutical products are commonly used to treat fever and malaria in sub-Saharan African countries. Small scale studies have suggested that poor quality antimalarials are widespread throughout the region, but nationwide data are not available that could lead to generalizable conclusions about the extent to which poor quality drugs are available in African communities. This study aimed to assess the quality of antimalarials available from retail outlets across mainland Tanzania. Methods and Findings We systematically purchased samples of oral antimalarial tablets from retail outlets across 21 districts in mainland Tanzania in 2005. A total of 1080 antimalarial formulations were collected including 679 antifol antimalarial samples (394 sulfadoxine/pyrimethamine and 285 sulfamethoxypyrazine/pyrimethamine), 260 amodiaquine samples, 63 quinine samples, and 51 artemisinin derivative samples. A systematic subsample of 304 products was assessed for quality by laboratory based analysis to determine the amount of the active ingredient and dissolution profile by following the published United States Pharmacopoeia (USP) monogram for the particular tablet being tested. Products for which a published analytical monogram did not exist were assessed on amount of active ingredient alone. Overall 38 or 12.2% of the samples were found to be of poor quality. Of the antifolate antimalarial drugs tested 13.4% were found to be of poor quality by dissolution and content analysis using high-performance liquid chromatography (HPLC). Nearly one quarter (23.8%) of quinine tablets did not comply within the tolerance limits of the dissolution and quantification analysis. Quality of amodiaquine drugs was relatively better but still unacceptable as 7.5% did not comply within the tolerance limits of the dissolution analysis. Formulations of the artemisinin derivatives all contained the stated amount of active ingredient when analysed using HPLC alone. Conclusions Substandard antimalarial formulations were widely available in Tanzania at the time of this study. No products were detected that did not contain any amount of the stated active ingredient. Quinine and sulfadoxine/pyrimethamine products were the most widely available and also the most likely to be of poor quality. Substandard products were identified in all parts of the country and were labeled as made by both domestic and international manufacturers. With the expansion of the retail pharmaceutical sector as a delivery channel for antimalarial formulations the need for regular nationwide monitoring of their quality will become increasingly important. PMID:18923672
A nationwide survey of the quality of antimalarials in retail outlets in Tanzania.
Kaur, Harparkash; Goodman, Catherine; Thompson, Eloise; Thompson, Katy-Anne; Masanja, Irene; Kachur, S Patrick; Abdulla, Salim
2008-01-01
Retail pharmaceutical products are commonly used to treat fever and malaria in sub-Saharan African countries. Small scale studies have suggested that poor quality antimalarials are widespread throughout the region, but nationwide data are not available that could lead to generalizable conclusions about the extent to which poor quality drugs are available in African communities. This study aimed to assess the quality of antimalarials available from retail outlets across mainland Tanzania. We systematically purchased samples of oral antimalarial tablets from retail outlets across 21 districts in mainland Tanzania in 2005. A total of 1080 antimalarial formulations were collected including 679 antifol antimalarial samples (394 sulfadoxine/pyrimethamine and 285 sulfamethoxypyrazine/pyrimethamine), 260 amodiaquine samples, 63 quinine samples, and 51 artemisinin derivative samples. A systematic subsample of 304 products was assessed for quality by laboratory based analysis to determine the amount of the active ingredient and dissolution profile by following the published United States Pharmacopoeia (USP) monogram for the particular tablet being tested. Products for which a published analytical monogram did not exist were assessed on amount of active ingredient alone. Overall 38 or 12.2% of the samples were found to be of poor quality. Of the antifolate antimalarial drugs tested 13.4% were found to be of poor quality by dissolution and content analysis using high-performance liquid chromatography (HPLC). Nearly one quarter (23.8%) of quinine tablets did not comply within the tolerance limits of the dissolution and quantification analysis. Quality of amodiaquine drugs was relatively better but still unacceptable as 7.5% did not comply within the tolerance limits of the dissolution analysis. Formulations of the artemisinin derivatives all contained the stated amount of active ingredient when analysed using HPLC alone. Substandard antimalarial formulations were widely available in Tanzania at the time of this study. No products were detected that did not contain any amount of the stated active ingredient. Quinine and sulfadoxine/pyrimethamine products were the most widely available and also the most likely to be of poor quality. Substandard products were identified in all parts of the country and were labeled as made by both domestic and international manufacturers. With the expansion of the retail pharmaceutical sector as a delivery channel for antimalarial formulations the need for regular nationwide monitoring of their quality will become increasingly important.
NASA Technical Reports Server (NTRS)
Coulbourn, W. C.; Egan, W. G. (Principal Investigator)
1973-01-01
The author has identified the following significant results. Attempts to correlate optical aircraft remote sensing of water quality with the optical data from the ERTS-1 satellite using calibrated imagery of Charlotte Amalie harbor, St. Thomas, Virgin Islands are reported. The harbor at Charlotte Amalie has a concentration of a number of factors affecting water quality: untreated sewage, land runoff, and sediment from navigation and dredging operations. Calibration procedures have been originated and applied to ERTS-1 and I2S camera imagery. The results indicate that the ERTS-1 and I2S imagery are correlated with optical in situ measurements of the harbor water. The aircraft green photographic and ERTS-1 MSS-4 bands have been found most suitable for monitoring the scattered light levels under the conditions of the investigation. The chemical parameters of the harbor water were found to be correlated to the optical properties for two stations investigated in detail. The biological properties of the harbor water (chlorophyll and carotenoids), correlate inversely with the optical data near the pollution sources compared to further away. Calibration procedures developed in this investigation were essential to the interpretation of the photographic and ERTS-1 photometric responses.
Patouillard, Edith; Goodman, Catherine A; Hanson, Kara G; Mills, Anne J
2007-11-07
There has been a growing interest in the role of the private for-profit sector in health service provision in low- and middle-income countries. The private sector represents an important source of care for all socioeconomic groups, including the poorest and substantial concerns have been raised about the quality of care it provides. Interventions have been developed to address these technical failures and simultaneously take advantage of the potential for involving private providers to achieve public health goals. Limited information is available on the extent to which these interventions have successfully expanded access to quality health services for poor and disadvantaged populations. This paper addresses this knowledge gap by presenting the results of a systematic literature review on the effectiveness of working with private for-profit providers to reach the poor. The search topic of the systematic literature review was the effectiveness of interventions working with the private for-profit sector to improve utilization of quality health services by the poor. Interventions included social marketing, use of vouchers, pre-packaging of drugs, franchising, training, regulation, accreditation and contracting-out. The search for published literature used a series of electronic databases including PubMed, Popline, HMIC and CabHealth Global Health. The search for grey and unpublished literature used documents available on the World Wide Web. We focused on studies which evaluated the impact of interventions on utilization and/or quality of services and which provided information on the socioeconomic status of the beneficiary populations. A total of 2483 references were retrieved, of which 52 qualified as impact evaluations. Data were available on the average socioeconomic status of recipient communities for 5 interventions, and on the distribution of benefits across socioeconomic groups for 5 interventions. Few studies provided evidence on the impact of private sector interventions on quality and/or utilization of care by the poor. It was, however, evident that many interventions have worked successfully in poor communities and positive equity impacts can be inferred from interventions that work with types of providers predominantly used by poor people. Better evidence of the equity impact of interventions working with the private sector is needed for more robust conclusions to be drawn.
Patouillard, Edith; Goodman, Catherine A; Hanson, Kara G; Mills, Anne J
2007-01-01
Background There has been a growing interest in the role of the private for-profit sector in health service provision in low- and middle-income countries. The private sector represents an important source of care for all socioeconomic groups, including the poorest and substantial concerns have been raised about the quality of care it provides. Interventions have been developed to address these technical failures and simultaneously take advantage of the potential for involving private providers to achieve public health goals. Limited information is available on the extent to which these interventions have successfully expanded access to quality health services for poor and disadvantaged populations. This paper addresses this knowledge gap by presenting the results of a systematic literature review on the effectiveness of working with private for-profit providers to reach the poor. Methods The search topic of the systematic literature review was the effectiveness of interventions working with the private for-profit sector to improve utilization of quality health services by the poor. Interventions included social marketing, use of vouchers, pre-packaging of drugs, franchising, training, regulation, accreditation and contracting-out. The search for published literature used a series of electronic databases including PubMed, Popline, HMIC and CabHealth Global Health. The search for grey and unpublished literature used documents available on the World Wide Web. We focused on studies which evaluated the impact of interventions on utilization and/or quality of services and which provided information on the socioeconomic status of the beneficiary populations. Results A total of 2483 references were retrieved, of which 52 qualified as impact evaluations. Data were available on the average socioeconomic status of recipient communities for 5 interventions, and on the distribution of benefits across socioeconomic groups for 5 interventions. Conclusion Few studies provided evidence on the impact of private sector interventions on quality and/or utilization of care by the poor. It was, however, evident that many interventions have worked successfully in poor communities and positive equity impacts can be inferred from interventions that work with types of providers predominantly used by poor people. Better evidence of the equity impact of interventions working with the private sector is needed for more robust conclusions to be drawn. PMID:17988396
Bonu, Sekhar; Rani, Manju; Bishai, David
2003-12-01
The study uses data from the Tanzania Human Resources Development Survey (1994) on willingness to pay (WTP) for desired quality of health care at lower-level health facilities to assess potential regressiveness of user fees - a disproportionately higher negative effect of user fees on utilization of health services among the poor compared with the rich. Despite reports of extensive bypassing of the lower-level health facilities in Tanzania, the WTP for quality health care at these health facilities is surprisingly large. WTP was lower among the poor, female and elderly respondents. Almost one-quarter of the poorest 40% of the population was not willing to pay even when the quality of services met their expectations. The results suggest that: the utilization of health services at lower-level health facilities can be increased by improving the quality of care; and the implementation of uniform user charges in the public facilities may be regressive, adversely affecting utilization among the poor, women and the elderly. An effective system of exemptions and waivers will be required for the very poor who may not be able to pay even when quality of services is improved. The findings of the study have policy implications for the Tanzanian government's recent attempts to expand cost-sharing through community health funds at lower-level health facilities, being introduced since 1998.
Sleep quality, fatigue and physical activity following a cancer diagnosis.
Humpel, N; Iverson, D C
2010-11-01
Research on physical activity for cancer survivors suggests a relationship with improved quality of life. The aim of this study was to explore if there was also a relationship of physical activity with sleep difficulties and fatigue, common effects of cancer and its treatments. Recruitment was by posters and flyers in medical waiting rooms and by letter of invitation. Thirty-two breast and 59 prostate cancer survivors completed the questionnaire. Poor sleep quality was reported by 57.8%. A greater proportion of breast cancer (36.7%) than prostate cancer survivors (15.5%) reported poor sleep latency, and sleep disturbance (48.4% vs. 17.2%). The mean minutes of moderate physical activity was lower among participants reporting poor sleep quality [F(1,89) = 11.36, P < 0.001]. A greater proportion of breast cancer (65.7%) than prostate cancer survivors (43.1%) reported high fatigue. Participants who reported no physical activity had significantly greater fatigue (M = 31) than those reporting high physical activity levels (M = 42). While at an early stage of research, results are suggestive of a relationship of physical activity with sleep problems among cancer survivors. Findings have implications for improving quality of life as poor sleep was associated with greater fatigue and regular physical activity shows promise as an aid to alleviating these problems. © 2009 The Authors. European Journal of Cancer Care © 2009 Blackwell Publishing Ltd.
Devkota, Bhuminand; Takahashi, Ken-Ichi; Matsuzaki, Shigenori; Matsui, Motozumi; Miyamoto, Akio; Yamagishi, Norio; Osawa, Takeshi; Hashizume, Tsutomu; Izaike, Yoshiaki; Miyake, Yoh-Ichi
2011-06-01
The present study investigated the basal levels and GnRH-induced responses of peripheral testosterone and estrogen in Holstein bulls with poor semen quality. On the basis of semen parameters, bulls (n=5) having poor semen quality were selected as experimental bulls, and good semen quality bulls (n=4) were used as control bulls. Both groups were treated intramuscularly once with GnRH (250 µg of fertirelin acetate). Blood samples were collected at -1 day (d), -30 min and 0 h (treatment) followed by every 30 min for 5 h and 1, 3 and 5 d post-GnRH treatment (PGT), and LH, testosterone and estradiol-17β (E(2)) concentrations were measured. The pretreatment concentrations were used as basal levels. The percentage increments based on the 0-h levels were calculated per bull for each sampling time until 5 h PGT, and differences were compared between the experimental and control groups. The PGT concentrations of testosterone and basal and PGT concentrations of E(2) were significantly lower in the experimental group. The testosterone increment in the experimental group was delayed and significantly lower from 1 to 5 h PGT than those in the control group. It can be suggested that bulls with poor semen quality have delayed and lower GnRH-induced testosterone response and may also have lower estrogen levels.
How nurse leaders can foster a climate of good governance.
Bassett, Sally; Westmore, Kathryn
2012-09-01
This article is the first in a series of four examining the components of good corporate governance. Poor governance can result in patients receiving poor quality care; all healthcare professionals, therefore, have a role in ensuring effective governance. This article discusses how an organisation's culture and leadership can contribute to good corporate governance. Nurse leaders can influence the culture of effective governance by building trust and respect and challenging the behaviours that led to poor quality care. The next article in this series will look at how an organisation's systems and processes can affect the effectiveness of its governance.
Ensuring long-term reliability of the data storage on optical disc
NASA Astrophysics Data System (ADS)
Chen, Ken; Pan, Longfa; Xu, Bin; Liu, Wei
2008-12-01
"Quality requirements and handling regulation of archival optical disc for electronic records filing" is released by The State Archives Administration of the People's Republic of China (SAAC) on its network in March 2007. This document established a complete operative managing process for optical disc data storage in archives departments. The quality requirements of the optical disc used in archives departments are stipulated. Quality check of the recorded disc before filing is considered to be necessary and the threshold of the parameter of the qualified filing disc is set down. The handling regulations for the staffs in the archives departments are described. Recommended environment conditions of the disc preservation, recording, accessing and testing are presented. The block error rate of the disc is selected as main monitoring parameter of the lifetime of the filing disc and three classes pre-alarm lines are created for marking of different quality check intervals. The strategy of monitoring the variation of the error rate curve of the filing discs and moving the data to a new disc or a new media when the error rate of the disc reaches the third class pre-alarm line will effectively guarantee the data migration before permanent loss. Only when every step of the procedure is strictly implemented, it is believed that long-term reliability of the data storage on optical disc for archives departments can be effectively ensured.
Selvi, Yavuz; Kandeger, Ali; Boysan, Murat; Akbaba, Nursel; Sayin, Ayca A; Tekinarslan, Emine; Koc, Basak O; Uygur, Omer F; Sar, Vedat
2017-10-01
Individuals who differ markedly by sleep chronotype, i.e., morning-type or evening-type also differ on a number of psychological, behavioral, and biological variables. Among several other psychological functions, dissociation may also lead to disruption and alteration of consciousness, which may facilitate dream-like experiences. Our study was aimed at an inquiry into the effects of individual biological rhythm differences on sleep quality and daytime sleepiness in conjunction with dissociative experiences. Participants were 372 undergraduate college students, completed a package of psychological instruments, including the Morningness-Eveningness Questionnaire, Dissociative Experiences Scale, Insomnia Severity Index, and Epworth Sleepiness Scale. Using logistic regression models, direct relations of pathological dissociation with sleepiness, sleep quality and circadian preferences were investigated. Poor sleep quality and sleepiness significantly contributed to the variance of dissociative symptomatology. Although there was no substantial linear association between circadian preferences and pathological dissociation, having evening-type preferences of sleep was indirectly associated with higher dissociation mediated by poor sleep quality. Poor sleep quality and daytime sleepiness seems to be significant antecedents of pathological dissociation. Sleep chronotype preferences underlie this relational pattern that chronobiological characteristics seem to influence indirectly on dissociative tendency via sleep quality. Copyright © 2017 Elsevier B.V. All rights reserved.
Ghazi Sherbaf, Farzaneh; Mojtahed Zadeh, Mahtab; Haghshomar, Maryam; Aarabi, Mohammad Hadi
2018-03-14
Psychiatric symptoms and motor impairment are major contributions to the poor quality of life in patients with Parkinson's disease (PD). Here, we applied a novel diffusion-weighted imaging approach, diffusion MRI connectometry, to investigate the correlation of quality of life, evaluated by Parkinson's Disease Questionnaire (PDQ39) with the white matter structural connectivity in 27 non-demented PD patients (disease duration of 5.3 ± 2.9 years, H and Y stage = 1.5 ± 0.6, UPDRS-III = 13.7 ± 6.5, indicating unilateral and mild motor involvement). The connectometry analysis demonstrated bilateral posterior limbs of the internal capsule (PLIC) with increased connectivity related to the higher quality of life (FDR = 0.027) in a multiple regression model. The present study suggests for the first time a neural basis of the quality of life in PD in the light of major determinants of poor quality of life in these patients: anxiety, depression, apathy and motor impairment. Results in our sample of non-demented PD patients with relatively mild motor impairment and no apparent sign of depression/anxiety also identify a unique and inexplicable association of the PLIC to the quality of life in PD patients.
Quality of life in inflammatory bowel disease patients: A cross-sectional study.
Habibi, Farzaneh; Habibi, Mohammad Emadoddin; Gharavinia, Ali; Mahdavi, Sadegh Baradaran; Akbarpour, Mohammad Javad; Baghaei, Abdolmehdi; Emami, Mohammad Hassan
2017-01-01
Inflammatory bowel disease (IBD) has a significant impact on health-related quality of life (HRQOL). This study aims to investigate the variables which can be attributed to HRQOL in IBD patients. Seventy-one patients filled in IBD questionnaire (IBDQ-32), Pittsburgh sleep quality index questionnaire, and sociodemographic questionnaire. Disease activity was assessed by Crohn's disease activity index (CDAI) and ulcerative colitis activity index (UCAI). The correlations of sleep quality, sociodemographic variables, and disease characteristics with IBDQ were investigated. IBDQ-32 mean score was lower in patients who had hospitalization ( P = 0.01), poor sleep quality ( P < 0.001), anemia ( P = 0.03), more severe disease ( P = 0.01), and those who had not consumed folic acid ( P = 0.01) relative to their counterparts. A multivariate regression analysis identified the predictors of decreased HRQOL as not consuming folic acid ( P = 0.008), poor sleep quality ( P = 0.014), and disease severity ( P = 0.043). Impaired HRQOL was significantly associated with poor sleep quality, lack of folic acid consumption, and disease severity in IBD patients. Therefore, evaluation of folic acid level and efficacy of its supplementation in prospective studies is recommended. Treatment of sleep disturbance with pharmacological agents and nonpharmacological methods should be kept in mind as well.
The interaction between sleep quality and academic performance.
Ahrberg, K; Dresler, M; Niedermaier, S; Steiger, A; Genzel, L
2012-12-01
Sleep quality has significant effects on cognitive performance and is influenced by multiple factors such as stress. Contrary to the ideal, medical students and residents suffer from sleep deprivation and stress at times when they should achieve the greatest amount of learning. In order to examine the relationship between sleep quality and academic performance, 144 medical students undertaking the pre-clinical board exam answered a survey regarding their subjective sleep quality (Pittsburgh sleep quality index, PSQI), grades and subjective stress for three different time points: semester, pre- and post-exam. Academic performance correlated with stress and sleep quality pre-exam (r = 0.276, p < 0.001 and r = 0.158, p < 0.03, note that low performance meant low sleep quality and high stress), however not with the stress or sleep quality during the semester and post-exam. 59% of all participants exhibited clinically relevant sleep disturbances (PSQI > 5) during exam preparation compared to 29% during the semester and 8% post-exam. This study shows that in medical students it is not the generally poor sleepers, who perform worse in the medical board exams. Instead students who will perform worse on their exams seem to be more stressed and suffer from poor sleep quality. However, poor sleep quality may negatively impact test performance as well, creating a vicious circle. Furthermore, the rate of sleep disturbances in medical students should be cause for intervention. Copyright © 2012 Elsevier Ltd. All rights reserved.
Chou, Yu-Tsung; Cheng, Hsiang-Ju; Wu, Jin-Shang; Yang, Yi-Ching; Chou, Chieh-Ying; Chang, Chih-Jen; Lu, Feng-Hwa
2018-06-18
The association of sleep duration/quality with nonalcoholic fatty liver disease (NAFLD) is inconclusive. Several important covariates were not adjusted concomitantly in some studies, and the severity of NAFLD was not considered. Furthermore, the gender impact of sleep duration or sleep quality on NAFLD remains unclear. We thus aimed to examine the association of sleep duration and quality with NAFLD by gender in a Taiwanese population. A total of 6663 subjects aged 18 years or more were enrolled. The severity of NAFLD was divided into mild, moderate, and severe degrees based on ultrasound findings. The sleep duration was classified into three groups: short (<6h), normal (6-8h), and long (>8h). Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality, and poor sleep quality was defined as a global PSQI score greater than 5. After adjustment for potential confounders, multinomial logistic regression showed that poor sleep quality was negatively associated with both mild and moderate-to-severe NAFLD in males, but sleep duration was not independently related to NAFLD. In females, sleep condition was not related to NAFLD. Poor sleep quality but not sleep duration was associated with a lower risk of not only moderate to severe but also mild NAFLD in males. In females, the association of sleep quality and duration with the risk of NAFLD was insignificant. Copyright © 2018 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.