Improvement of near infrared body fat sensing at 45-degree source-detector position angle

2016 ◽  
Author(s):  
Fatin Hamimi Mustafa ◽  
Peter W Jones ◽  
Jacqueline Huvanandana ◽  
Alistair L McEwan
Keyword(s):  
Body Fat ◽  
Near Infrared ◽  
Position Angle ◽  
Detector Position

scholarly journals Field methods in the evaluation of obesity in children and adolescents

2009 ◽  
Vol 9 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Míriam Akemi Sampei ◽  
Dirce Maria Sigulem
Keyword(s):  
Body Mass Index ◽  
Body Composition ◽  
Waist Circumference ◽  
Body Fat ◽  
Direct Relationship ◽  
Near Infrared ◽  
Field Methods ◽  
Large Samples ◽  
Infrared Methods ◽  
Better Than

In large samples, the methods for obtaining information on obesity need to be simple, inexpensive and reasonably accurate. This review deals with articles focusing on various field methods for the evaluation of body composition. The Bioimpedance and Near Infrared methods are simple to execute but their advantage in relation to Body Mass Index is obscure. Although the Bioimpedance and near infrared methods provide estimates of fat content, they may be no better than waist circumference measurements. The latter does not distinguish body fat but points to a more direct relationship concerning health risk. Regardless of the advantages, waist circumference continues to be under discussion: there is a lack of standardization and no reference populations or cutoff points have been established. No perfect method exists, but the number of errors could be reduced, if care were taken in drawing up protocols, standardization, and the analysis of sample properties.

scholarly journals Evaluation of Measurement Sites for Noninvasive Blood Glucose Sensing with Near-Infrared Transmission Spectroscopy

1999 ◽  
Vol 45 (9) ◽  
pp. 1621-1627 ◽  
Author(s):  
Jason J Burmeister ◽  
Mark A Arnold
Keyword(s):  
Blood Glucose ◽  
Body Fat ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Glucose Sensing ◽  
Infrared Transmission ◽  
Signal To Noise ◽  
Lower Lip ◽  
Percentage Of Body Fat ◽  
Noise Ratio

Abstract Six putative measurement sites were evaluated for noninvasive sensing of blood glucose by first-overtone near-infrared spectroscopy. The cheek, lower lip, upper lip, nasal septum, tongue, and webbing tissue between the thumb and forefinger were examined. These sites were evaluated on the basis of their chemical and physical properties as they pertain to the noninvasive measurement of glucose. Critical features included the effective optical pathlength of aqueous material within the tissue and the percentage of body fat within the optical path. Aqueous optical paths of 5 mm are required to measure clinically relevant concentrations of glucose in the first-overtone region. All of the tested sites met this requirement. The percentage of body fat affects the signal-to-noise ratio of the measurement and must be minimized for reliable glucose sensing. The webbing tissue contains a considerable amount of fat tissue and is clearly the worse measurement site. All other sites possess substantially less fat, with the least amount of fat in tongue tissue. For this reason, the tongue provides spectra with the highest signal-to-noise ratio and is, therefore, the site of choice on the basis of spectral quality.

Validity of Near-Infrared Interactance for Estimating Relative Body Fat in Female High School Gymnasts

1997 ◽  
Vol 18 (07) ◽  
pp. 531-537 ◽  
Author(s):  
D. Smith ◽  
G. Johnson ◽  
J. Stout ◽  
T. Housh ◽  
D. Housh ◽  
...  
Keyword(s):  
High School ◽  
Body Fat ◽  
Near Infrared ◽  
Female High School

scholarly journals Shadows and asymmetries in the T Tauri disk HD 143006: evidence for a misaligned inner disk

2018 ◽  
Vol 619 ◽  
pp. A171 ◽  
Author(s):  
M. Benisty ◽  
A. Juhász ◽  
S. Facchini ◽  
P. Pinilla ◽  
J. de Boer ◽  
...  
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Scattered Light ◽  
Three Dimensional ◽  
Angular Separation ◽  
Position Angle ◽  
Disk Model ◽  
Disk Structure ◽  
T Tauri ◽  
Western Side

Context. While planet formation is thought to occur early in the history of a protoplanetary disk, the presence of planets embedded in disks, or of other processes driving disk evolution, might be traced from their imprints on the disk structure. Aims. We study the morphology of the disk around the T Tauri star HD 143006, located in the ~5–11 Myr-old Upper Sco region, and we look for signatures of the mechanisms driving its evolution. Methods. We observed HD 143006 in polarized scattered light with VLT/SPHERE at near-infrared (J-band, 1.2 μm) wavelengths, reaching an angular resolution of ~0.037′′ (~6 au). We obtained two datasets, one with a 145 mas diameter coronagraph, and the other without, enabling us to probe the disk structure down to an angular separation of ~0.06′′ (~10 au). Results. In our observations, the disk of HD 143006 is clearly resolved up to ~0.5′′ and shows a clear large-scale asymmetry with the eastern side brighter than the western side. We detect a number of additional features, including two gaps and a ring. The ring shows an overbrightness at a position angle (PA) of ~140°, extending over a range in position angle of ~60°, and two narrow dark regions. The two narrow dark lanes and the overall large-scale asymmetry are indicative of shadowing effects, likely due to a misaligned inner disk. We demonstrate the remarkable resemblance between the scattered light image of HD 143006 and a model prediction of a warped disk due to an inclined binary companion. The warped disk model, based on the hydrodynamic simulations combined with three-dimensional radiative transfer calculations, reproduces all major morphological features. However, it does not account for the observed overbrightness at PA ~ 140°. Conclusions. Shadows have been detected in several protoplanetary disks, suggesting that misalignment in disks is not uncommon. However, the origin of the misalignment is not clear. As-yet-undetected stellar or massive planetary companions could be responsible for them, and naturally account for the presence of depleted inner cavities.

scholarly journals Association Among SF36 Quality of Life Measures and Nutrition, Hospitalization, and Mortality in Hemodialysis

2001 ◽  
Vol 12 (12) ◽  
pp. 2797-2806 ◽  
Author(s):  
Kamyar Kalantar-Zadeh ◽  
Joel D. Kopple ◽  
Gladys Block ◽  
Michael H. Humphreys
Keyword(s):  
Quality Of Life ◽  
Clinical Outcomes ◽  
Body Fat ◽  
Near Infrared ◽  
Short Form ◽  
Two Dimensions ◽  
Maintenance Hemodialysis ◽  
Obese Patients ◽  
Risk Of Death

ABSTRACT. Patients on maintenance hemodialysis (MHD) often show substantial reductions in quality of life (QoL). The SF36 (Short Form with 36 questions), a well-documented, self-administered QoL scoring system that includes eight independent scales and two main dimensions, has been widely used and validated. In 65 adult outpatients on MHD, the SF36 and its scales and dimensions, scored as a number between 0 and 100, and the nutritional and inflammatory state measured by subjective global assessment, near-infrared (NIR) body fat, body mass index (BMI), and pertinent laboratory values, including hemoglobin, albumin, and C-reactive protein were assessed. Twelve-month prospective hospitalization rates and mortality were used as the clinical outcomes. Multivariate (case-mix) adjusted correlation coefficients were statistically significant between SF36 scores and serum albumin and hemoglobin concentrations. There were significant inverse correlations between SF36 scores and the BMI and NIR body fat percentage. Hypoalbuminemic, anemic, and obese patients on MHD had a worse QoL. Prospective hospitalizations correlated significantly with the SF36 total score and its two main dimensions (rbetween −0.28 and −0.40). The Cox proportional regression relative risk of death for each 10 unit decrease in SF36 was 2.07 (95% CI, 1.08 to 3.98;P= 0.02). Of the eight components and two dimensions of the SF36, the Mental Health dimension and the SF36 total score had the strongest predictive value for mortality. Thus, in patients on MHD the SF36 appears to have significant associations with measures of nutritional status, anemia, and clinical outcomes, including prospective hospitalization and mortality. Even though obesity, unlike undernutrition, is not generally an indicator of poor outcome in MHD, the SF36 may detect obese patients on MHD at higher risk for morbidity and mortality.

scholarly journals Compact gaseous accretion disk in Keplerian rotation around MWC 147

2019 ◽  
Vol 623 ◽  
pp. A38
Author(s):  
Edward Hone ◽  
Stefan Kraus ◽  
Claire L. Davies ◽  
Alexander Kreplin ◽  
John D. Monnier ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Accretion Disk ◽  
Near Infrared ◽  
Geometric Model ◽  
Rotational Velocity ◽  
Kinematic Model ◽  
Position Angle ◽  
Central Star ◽  
Be Stars ◽  
The Continuum

Context. The disks around some Herbig Be stars have been observed to be more compact than the expected dust sublimation radius for such objects. Highly refractory dust grains and optically thick gas emission have been proposed as possible explanations for this phenomenon. Aims. Previously, the “undersized” Herbig Be star MWC 147 was observed with interferometry, and the results indicated a presence of a compact gaseous disk based on the measured wavelength-dependence of near-infrared or mid-infrared visibilities. Our aim is to search for direct evidence for the presence of hot gas inside of the expected dust sublimation radius of MWC 147. Methods. By combining VLTI/AMBER spectro-interferometry (R = 12 000) with CRIRES spectroscopy (R = 100 000) we can both spectrally and spatially resolve the Brγ line-emitting gas around MWC 147. Additionally, using CHARA/CLIMB enables us to achieve baseline lengths up to 330 m, offering ~2 times higher angular resolution (and a better position angle coverage) than has previously been achieved with interferometry for MWC 147. To model the continuum we fit our AMBER and CLIMB measurements with a geometric model of an inclined Gaussian distribution as well as a ring model. We fit our high-resolution spectra and spectro-interferometric data with a kinematic model of a disk in Keplerian rotation. Results. Our interferometric visibility modelling of MWC 147 indicates the presence of a compact continuum disk with a close to face-on orientation. We model the continuum with an inclined Gaussian and a ring with a radius of 0.60 mas (0.39 au), which is well within the expected dust sublimation radius of 1.52 au. We detect no significant change in the measured visibilities across the Brγ line, indicating that the line-emitting gas is located in the same region as the continuum-emitting disk. Using our differential phase data we construct photocentre displacement vectors across the Brγ line, revealing a velocity profile consistent with a rotating disk. We fit our AMBER spectro-interferometry data with a kinematic model of a disk in Keplerian rotation, where both the line-emitting and continuum-emitting components of the disk originate from the same compact region close to the central star. The presence of line-emitting gas in the same region as the K-band continuum supports the interpretation that the K-band continuum traces an optically thick gas disk. Conclusions. Our spatially and spectrally resolved observations of MWC 147 reveal that the K-band continuum and Brγ emission both originate from a similar region which is 3.9 times more compact than the expected dust sublimation radius for the star; Brγ is emitted from the accretion disk or disk wind region and exhibits a rotational velocity profile. We conclude that we detect the presence of a compact, gaseous accretion disk in Keplerian rotation around MWC 147.

scholarly journals Highly structured disk around the planet host PDS 70 revealed by high-angular resolution observations with ALMA

2019 ◽  
Vol 625 ◽  
pp. A118 ◽  
Author(s):  
M. Keppler ◽  
R. Teague ◽  
J. Bae ◽  
M. Benisty ◽  
T. Henning ◽  
...  
Keyword(s):  
Near Infrared ◽  
Angular Resolution ◽  
Dust Emission ◽  
Mass Range ◽  
Position Angle ◽  
Circumstellar Disk ◽  
High Angular Resolution ◽  
Gas Kinematics ◽  
Hydrodynamical Simulations ◽  
Dust Ring

Context. Imaged in the gap of a transition disk and found at a separation of about 195 mas (~22 au) from its host star at a position angle of about 155°, PDS 70 b is the most robustly detected young planet to date. This system is therefore a unique laboratory for characterizing the properties of young planetary systems at the stage of their formation. Aims. We aim to trace direct and indirect imprints of PDS 70 b on the gas and dust emission of the circumstellar disk in order to study the properties of this ~5 Myr young planetary system. Methods. We obtained ALMA band 7 observations of PDS 70 in dust continuum and 12CO (3–2) and combined them with archival data. This resulted in an unprecedented angular resolution of about 70 mas (~8 au). Results. We derive an upper limit on circumplanetary material at the location of PDS 70 b of ~0.01 M⊕ and find a highly structured circumstellar disk in both dust and gas. The outer dust ring peaks at 0.65′′ (74 au) and reveals a possible second unresolved peak at about 0.53′′ (60 au). The integrated intensity of CO also shows evidence of a depletion of emission at ~0.2′′ (23 au) with a width of ~0.1′′ (11 au). The gas kinematics show evidence of a deviation from Keplerian rotation inside ≲0.8′′ (91 au). This implies a pressure gradient that can account for the location of the dust ring well beyond the location of PDS 70 b. Farther in, we detect an inner disk that appears to be connected to the outer disk by a possible bridge feature in the northwest region in both gas and dust. We compare the observations to hydrodynamical simulations that include a planet with different masses that cover the estimated mass range that was previously derived from near-infrared photometry (~5–9 MJup). We find that even a planet with a mass of 10 MJup may not be sufficient to explain the extent of the wide gap, and an additional low-mass companion may be needed to account for the observed disk morphology.

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