Correlation of soft palate length with velum obstruction and severity of obstructive sleep apnea syndrome.

PubMed

Lim, Ju-Shin; Lee, Jae Woo; Han, Chun; Kwon, Jang-Woo

2018-06-01

Our aim in this study was to analyze whether soft palate length and velum obstruction during sleep are correlated and to determine the effects of related parameters on obstructive sleep apnea syndrome (OSAS) severity. We used computed tomography to measure soft palate length and drug-induced sleep endoscopy (DISE) to evaluate velum obstruction severity. Patients also underwent polysomnography (PSG) for evaluation of OSAS severity. A retrospective cohort of 67 patients with OSAS treated between May 1st, 2013 and July 31st, 2016 was analyzed. Each patient underwent DISE, PSG, and computed tomography. Using DISE, velum obstruction was categorized by the VOTE classification method. Using computed tomography, soft palate length was measured as the length of the posterior nasal spine to the uvula. Correlations of velum obstruction in DISE and PSG parameters (obstructive apnea, hypopnea, apnea hypopnea index (AHI), respiratory effort related arousal (RERA), respiratory disturbance index (RDI), baseline SaO 2 , and minimum SaO 2 ) with soft palate length were also analyzed. Among the 67 patients, the average PNS-U length was 39.90±4.19mm. Length was significantly different by age but not by other demographic characteristics such as sex, past history, or BMI. DISE revealed a statistically significant difference of velum obstruction degree; the cutoff value for PNS-U was 39.47mm. The PSG results, obstructive apnea, AHI, RDI, baseline SaO 2 , and minimum SaO 2 were correlated with PNS-U length, while other results such as hypopnea and RERA showed no correlation. Analysis of soft palate length showed that increased PNS-U length was associated with higher rates of obstructive apnea, AHI, and RDI as assessed by PSG. In contrast, lower baseline SaO 2 and minimum SaO 2 values were seen by PSG; more severe velum obstruction was seen by DISE. We propose that when a soft palate is suspected in OSAS, computed tomography measurement of soft palate length is a valid method for

Correlation between Visible Length of the Iris and the Length of the Maxillary Central Incisor Using Digital Image Analysis- A Pilot Study.

PubMed

Rohini; Hemalatha; Chander, Gopi Naveen; Anitha, Kuttae Viswanathan

2017-02-01

Complete denture therapy is one such modality where science and art goes hand in hand. Selection of artificial teeth for completely edentulous patients is not easy in the absence of pre extraction records, because till date concrete guidelines do not exist. The purpose of this study was to determine if a correlation existed between the visible length of the iris and the length of the maxillary central incisor to potentially provide a guide for teeth selection. A total of 20 Indian dental students consented to participate in the pilot study. Standardized digital images of the face revealing the eyes and component of teeth on smiling was captured using a digital camera. The digital measurements of the visible iris length (medial aperture height, tangential to iris) and the length of the maxillary central incisor from the zenith to the incisal edge were analysed using Adobe Photoshop creative cloud software. The data was statistically evaluated and results were tabulated. Karl Pearson's Coefficient of Correlation was utilized to detect if any association existed between the two variables. The mean value of length of central incisor was 10.39 mm and the mean value of the visible length of iris was found to be 12.9 mm. A Pearson correlation analysis revealed an r-value <0.3 indicating minimal association between the two variables with a p-value >0.01 (.322). On inference, the correlation between the visible iris length and that of maxillary central incisor were unable to produce a strong positive statistical association. However, an association factor between the two has been obtained. Deduction of 2.5 mm from the dimension of visible iris length will help in attaining the length of artificial maxillary central incisor tooth.

Morphology and Length Correlated in Terminal Flushes of Longleaf Pine Saplings

Treesearch

R.M. Allen; N.M. Scarbrough

1970-01-01

In longleafpine (Pinuspalustris Mill.) saplings growing in southern Mississippi the length of the first or spring flush was significantly correlated with that of the second flush; the correlation of length between flushes two and three was also statistically significant. The correlations were due more to similarities in internode elongation than to node number. Flush...

Correlation Length of Energy-Containing Structures in the Base of the Solar Corona

NASA Astrophysics Data System (ADS)

Abramenko, V.; Zank, G. P.; Dosch, A. M.; Yurchyshyn, V.

2013-12-01

An essential parameter for models of coronal heating and fast solar wind acceleration that relay on the dissipation of MHD turbulence is the characteristic energy-containing length of the squared velocity and magnetic field fluctuations transverse to the mean magnetic field inside a coronal hole (CH) at the base of the corona. The characteristic length scale defines directly the heating rate. Rather surprisingly, almost nothing is known observationally about this critical parameter. Currently, only a very rough estimate of characteristic length was obtained based on the fact that the network spacing is about 30000 km. We attempted estimation of this parameter from observations of photospheric random motions and magnetic fields measured in the photosphere inside coronal holes. We found that the characteristic length scale in the photosphere is about 600-2000 km, which is much smaller than that adopted in previous models. Our results provide a critical input parameter for current models of coronal heating and should yield an improved understanding of fast solar wind acceleration. Fig. 1-- Plotted is the natural logarithm of the correlation function of the transverse velocity fluctuations u^2 versus the spatial lag r for the two CHs. The color code refers to the accumulation time intervals of 2 (blue), 5 (green), 10 (red), and 20 (black) minutes. The values of the Batchelor integral length λ the correlation length ς and the e-folding length L in km are shown. Fig. 2-- Plot of the natural logarithm of the correlation function of magnetic fluctuations b^2 versus the spatial lag r. The insert shows this plot with linear axes.

Can we predict body height from segmental bone length measurements? A study of 3,647 children.

PubMed

Cheng, J C; Leung, S S; Chiu, B S; Tse, P W; Lee, C W; Chan, A K; Xia, G; Leung, A K; Xu, Y Y

1998-01-01

It is well known that significant differences exist in the anthropometric data of different races and ethnic groups. This is a cross-sectional study on segmental bone length based on 3,647 Chinese children of equal sex distribution aged 3-18 years. The measurements included standing height, weight, arm span, foot length, and segmental bone length of the humerus, radius, ulna, and tibia. A normality growth chart of all the measured parameters was constructed. Statistical analysis of the results showed a very high linear correlation of height with arm span, foot length, and segmental bone lengths with a correlation coefficient of 0.96-0.99 for both sexes. No differences were found between the right and left side of all the segmental bone lengths. These Chinese children were found to have a proportional limb segmental length relative to the trunk.

Youth Baseball Pitching Stride Length: Normal Values and Correlation With Field Testing.

PubMed

Fry, Karl E; Pipkin, Andrew; Wittman, Kelcie; Hetzel, Scott; Sherry, Marc

Pitching biomechanical analysis has been recommended as an important component of performance, injury prevention, and rehabilitation. Normal values for youth pitching stride length have not been established, leading to application of normative values found among professional pitchers to youth pitchers. The average youth pitching stride length will be significantly less than that of college and professional pitchers. There will be a positive correlation between stride length, lower extremity power, balance, and pitching experience. Prospective cohort study. Level 3. Ninety-two youth baseball pitchers (aged 9-14 years) met the inclusion/exclusion criteria and completed the study. Stride length was recorded using a Dartfish video system over 3 maximal effort pitches. Both intra- and interrater reliability was calculated for the assessment of stride length. Double-leg vertical jump, single-leg stance time, leg length, weight, age, and pitching experience were also recorded. Mean (SD) stride length was 66.0% (7.1%) of height. Stride length was correlated ( P < 0.01) with vertical jump (0.38), pitching experience (0.36), and single-leg balance (0.28), with excellent intra- and interrater reliability (0.985 or higher). No significant correlations between stride length and body weight, leg length, or age existed. There was a significant difference between youth pitching stride length and the current published norms for older and more elite throwers. There was a positive correlation between stride length and lower extremity power, pitching experience, and single-leg balance. Two-dimensional analysis of stride length allows for the assessment of pitching biomechanics in a practical manner. These values can be used for return to pitching parameters after an injury and designing injury prevention and performance programs.

Youth Baseball Pitching Stride Length: Normal Values and Correlation With Field Testing

PubMed Central

Fry, Karl E.; Pipkin, Andrew; Wittman, Kelcie; Hetzel, Scott; Sherry, Marc

2016-01-01

Background: Pitching biomechanical analysis has been recommended as an important component of performance, injury prevention, and rehabilitation. Normal values for youth pitching stride length have not been established, leading to application of normative values found among professional pitchers to youth pitchers. Hypotheses: The average youth pitching stride length will be significantly less than that of college and professional pitchers. There will be a positive correlation between stride length, lower extremity power, balance, and pitching experience. Study Design: Prospective cohort study. Level of Evidence: Level 3. Methods: Ninety-two youth baseball pitchers (aged 9-14 years) met the inclusion/exclusion criteria and completed the study. Stride length was recorded using a Dartfish video system over 3 maximal effort pitches. Both intra- and interrater reliability was calculated for the assessment of stride length. Double-leg vertical jump, single-leg stance time, leg length, weight, age, and pitching experience were also recorded. Results: Mean (SD) stride length was 66.0% (7.1%) of height. Stride length was correlated (P < 0.01) with vertical jump (0.38), pitching experience (0.36), and single-leg balance (0.28), with excellent intra- and interrater reliability (0.985 or higher). No significant correlations between stride length and body weight, leg length, or age existed. Conclusions: There was a significant difference between youth pitching stride length and the current published norms for older and more elite throwers. There was a positive correlation between stride length and lower extremity power, pitching experience, and single-leg balance. Clinical Relevance: Two-dimensional analysis of stride length allows for the assessment of pitching biomechanics in a practical manner. These values can be used for return to pitching parameters after an injury and designing injury prevention and performance programs. PMID:27864504

Correlation between morphometry of the suprascapular notch and anthropometric measurements of the scapula.

PubMed

Polguj, M; Jędrzejewski, K S; Podgórski, M; Topol, M

2011-05-01

The concept of the study was to find the correlation between the morphometry of the suprascapular notch and basic anthropometric measurements of the human scapula. The measurements of the human scapulae included: morphological length and width, maximal width and length projection of scapular spine, length of acromion, and maximal length of the coracoid process. The glenoid cavity was measured in two perpendicular directions to evaluate its width and length. The width-length scapular and glenoid cavity indexes were calculated for every bone. In addition to standard anthropometric measurements two other measurements were defined and evaluated for every suprascapular notch: maximal depth (MD) and superior transverse diameter (STD). The superior transverse suprascapular ligament was completely ossified in 7% of cases. Ten (11.6%) scapulae had a discrete notch. In the studied material, in 21 (24.4%) scapulae the MD was longer than the STD. Two (2.3%) scapulae had equal maximal depth and superior transverse diameter. In 47 (57.7%) scapulae the superior transverse diameter was longer than the maximal depth. There was no statistically significant difference between anthropometric measurements in the group with higher MD and the group with higher STD. The maximal depth of the suprascapular notch negatively correlated with the scapular width-length index. The maximal depth of the scapular notch correlated with the morphological length of the scapulae.

Measurement of Telomere Length in Colorectal Cancers for Improved Molecular Diagnosis

PubMed Central

Le Balc’h, Eric; Grandin, Nathalie; Demattei, Marie-Véronique; Guyétant, Serge; Tallet, Anne; Ouaissi, Mehdi; Lecomte, Thierry

2017-01-01

All tumors have in common to reactivate a telomere maintenance mechanism to allow for unlimited proliferation. On the other hand, genetic instability found in some tumors can result from the loss of telomeres. Here, we measured telomere length in colorectal cancers (CRCs) using TRF (Telomere Restriction Fragment) analysis. Telomeric DNA content was also quantified as the ratio of total telomeric (TTAGGG) sequences over that of the invariable Alu sequences. In most of the 125 CRCs analyzed, there was a significant diminution in telomere length compared with that in control healthy tissue. Only 34 tumors exhibited no telomere erosion and, in some cases, a slight telomere lengthening. Telomere length did not correlate with age, gender, tumor stage, tumor localization or stage of tumor differentiation. In addition, while telomere length did not correlate with the presence of a mutation in BRAF (V-raf murine sarcoma viral oncogene homolog B), PIK3CA (phosphatidylinositol 3-kinase catalytic subunit), or MSI status, it was significantly associated with the occurrence of a mutation in KRAS. Interestingly, we found that the shorter the telomeres in healthy tissue of a patient, the larger an increase in telomere length in the tumor. Our study points to the existence of two types of CRCs based on telomere length and reveals that telomere length in healthy tissue might influence telomere maintenance mechanisms in the tumor. PMID:28850092

Measurement of Telomere Length in Colorectal Cancers for Improved Molecular Diagnosis.

PubMed

Balc'h, Eric Le; Grandin, Nathalie; Demattei, Marie-Véronique; Guyétant, Serge; Tallet, Anne; Pagès, Jean-Christophe; Ouaissi, Mehdi; Lecomte, Thierry; Charbonneau, Michel

2017-08-29

All tumors have in common to reactivate a telomere maintenance mechanism to allow for unlimited proliferation. On the other hand, genetic instability found in some tumors can result from the loss of telomeres. Here, we measured telomere length in colorectal cancers (CRCs) using TRF (Telomere Restriction Fragment) analysis. Telomeric DNA content was also quantified as the ratio of total telomeric (TTAGGG) sequences over that of the invariable Alu sequences. In most of the 125 CRCs analyzed, there was a significant diminution in telomere length compared with that in control healthy tissue. Only 34 tumors exhibited no telomere erosion and, in some cases, a slight telomere lengthening. Telomere length did not correlate with age, gender, tumor stage, tumor localization or stage of tumor differentiation. In addition, while telomere length did not correlate with the presence of a mutation in BRAF (V-raf murine sarcoma viral oncogene homolog B), PIK3CA (phosphatidylinositol 3-kinase catalytic subunit), or MSI status, it was significantly associated with the occurrence of a mutation in KRAS. Interestingly, we found that the shorter the telomeres in healthy tissue of a patient, the larger an increase in telomere length in the tumor. Our study points to the existence of two types of CRCs based on telomere length and reveals that telomere length in healthy tissue might influence telomere maintenance mechanisms in the tumor.

Relating Vegetation Aerodynamic Roughness Length to Interferometric SAR Measurements

NASA Technical Reports Server (NTRS)

Saatchi, Sassan; Rodriquez, Ernesto

1998-01-01

In this paper, we investigate the feasibility of estimating aerodynamic roughness parameter from interferometric SAR (INSAR) measurements. The relation between the interferometric correlation and the rms height of the surface is presented analytically. Model simulations performed over realistic canopy parameters obtained from field measurements in boreal forest environment demonstrate the capability of the INSAR measurements for estimating and mapping surface roughness lengths over forests and/or other vegetation types. The procedure for estimating this parameter over boreal forests using the INSAR data is discussed and the possibility of extending the methodology over tropical forests is examined.

Automated Defect and Correlation Length Analysis of Block Copolymer Thin Film Nanopatterns

PubMed Central

Murphy, Jeffrey N.; Harris, Kenneth D.; Buriak, Jillian M.

2015-01-01

Line patterns produced by lamellae- and cylinder-forming block copolymer (BCP) thin films are of widespread interest for their potential to enable nanoscale patterning over large areas. In order for such patterning methods to effectively integrate with current technologies, the resulting patterns need to have low defect densities, and be produced in a short timescale. To understand whether a given polymer or annealing method might potentially meet such challenges, it is necessary to examine the evolution of defects. Unfortunately, few tools are readily available to researchers, particularly those engaged in the synthesis and design of new polymeric systems with the potential for patterning, to measure defects in such line patterns. To this end, we present an image analysis tool, which we have developed and made available, to measure the characteristics of such patterns in an automated fashion. Additionally we apply the tool to six cylinder-forming polystyrene-block-poly(2-vinylpyridine) polymers thermally annealed to explore the relationship between the size of each polymer and measured characteristics including line period, line-width, defect density, line-edge roughness (LER), line-width roughness (LWR), and correlation length. Finally, we explore the line-edge roughness, line-width roughness, defect density, and correlation length as a function of the image area sampled to determine each in a more rigorous fashion. PMID:26207990

Assessment of passive muscle elongation using Diffusion Tensor MRI: Correlation between fiber length and diffusion coefficients.

PubMed

Mazzoli, Valentina; Oudeman, Jos; Nicolay, Klaas; Maas, Mario; Verdonschot, Nico; Sprengers, Andre M; Nederveen, Aart J; Froeling, Martijn; Strijkers, Gustav J

2016-12-01

In this study we investigated the changes in fiber length and diffusion parameters as a consequence of passive lengthening and stretching of the calf muscles. We hypothesized that changes in radial diffusivity (RD) are caused by changes in the muscle fiber cross sectional area (CSA) as a consequence of lengthening and shortening of the muscle. Diffusion Tensor MRI (DT-MRI) measurements were made twice in five healthy volunteers, with the foot in three different positions (30° plantarflexion, neutral position and 15° dorsiflexion). The muscles of the calf were manually segmented on co-registered high resolution anatomical scans, and maps of RD and axial diffusivity (AD) were reconstructed from the DT-MRI data. Fiber tractography was performed and mean fiber length was calculated for each muscle group. Significant negative correlations were found between the changes in RD and changes in fiber length in the dorsiflexed and plantarflexed positions, compared with the neutral foot position. Changes in AD did not correlate with changes in fiber length. Assuming a simple cylindrical model with constant volume for the muscle fiber, the changes in the muscle fiber CSA were calculated from the changes in fiber length. In line with our hypothesis, we observed a significant positive correlation of the CSA with the measured changes in RD. In conclusion, we showed that changes in diffusion coefficients induced by passive muscle stretching and lengthening can be explained by changes in muscle CSA, advancing the physiological interpretation of parameters derived from skeletal muscle DT-MRI. Copyright © 2016 John Wiley & Sons, Ltd.

Cubic law with aperture-length correlation: implications for network scale fluid flow

NASA Astrophysics Data System (ADS)

Klimczak, Christian; Schultz, Richard A.; Parashar, Rishi; Reeves, Donald M.

2010-06-01

Previous studies have computed and modeled fluid flow through fractured rock with the parallel plate approach where the volumetric flow per unit width normal to the direction of flow is proportional to the cubed aperture between the plates, referred to as the traditional cubic law. When combined with the square root relationship of displacement to length scaling of opening-mode fractures, total flow rates through natural opening-mode fractures are found to be proportional to apertures to the fifth power. This new relationship was explored by examining a suite of flow simulations through fracture networks using the discrete fracture network model (DFN). Flow was modeled through fracture networks with the same spatial distribution of fractures for both correlated and uncorrelated fracture length-to-aperture relationships. Results indicate that flow rates are significantly higher for correlated DFNs. Furthermore, the length-to-aperture relations lead to power-law distributions of network hydraulic conductivity which greatly influence equivalent permeability tensor values. These results confirm the importance of the correlated square root relationship of displacement to length scaling for total flow through natural opening-mode fractures and, hence, emphasize the role of these correlations for flow modeling.

RVUs poorly correlate with measures of surgical effort and complexity

PubMed Central

Shah, Dhruvil R.; Bold, Richard J.; Yang, Anthony D.; Khatri, Vijay P.; Martinez, Steve R.; Canter, Robert J.

2014-01-01

Background The relationship between procedural relative value units (RVUs) for surgical procedures and other measures of surgeon effort are poorly characterized. We hypothesized that RVUs would poorly correlate with quantifiable metrics of surgeon effort. Methods Using the 2010 ACS-NSQIP database, we selected 11 primary CPT codes associated with high volume surgical procedures. We then identified all patients with a single reported procedural RVU who underwent non-emergent, inpatient general surgical operations. We used linear regression to correlate length of stay, operative time, overall morbidity, frequency of serious adverse events (SAEs), and mortality with RVUs. We used multivariable logistic regression using all pre-operative NSQIP variables to determine other significant predictors of our outcome measures. Results Among 14,481 patients, RVUs poorly correlated with individual length of stay (R2=0.05), operative time (R2=0.10), and mortality (R2=0.35). There was a moderate correlation between RVUs and SAEs (R2 =0.79), and RVUs and overall morbidity (R2=0.75). However, among low to mid-level RVU procedures (11 to 35) there was a poor correlation between SAEs (R2=0.15), overall morbidity (R2=0.05), and RVUs. On multivariable analysis, RVUs were significant predictors of operative time, length of stay, and SAEs (OR 1.06, 95%CI: 1.05–1.07), but RVUs were not a significant predictor of mortality (OR 1.02, 95%CI: 0.99–1.05) Conclusion For common, index general surgery procedures, the current RVU assignments poorly correlate with certain metrics of surgeon work, while moderately correlating with others. Given the increasing emphasis on measuring and tracking surgeon productivity, more objective measures of surgeon work and productivity should be developed. PMID:24953983

Bunch Length Measurements at JLab FEL

DOE Office of Scientific and Technical Information (OSTI.GOV)

P. Evtushenko; J. L. Coleman; K. Jordan

2006-09-01

The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years. This diagnostic can be used only in the pulsed beam mode. It is our goal to run FEL with CW beam and 74.85 MHz micropulse repetition rate. Hence it is very desirable to have the possibility of doing the bunch length measurements when running CW beam with any micropulse frequency. We use a Fourier transform infrared interferometer, which is essentially a Michelson interferometer, to measuremore » the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides the bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with the data obtained by the Martin-Puplett interferometer. Results of the two diagnostics are usually agree within 15%. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.« less

Carotid-Femoral Pulse Wave Velocity: Impact of Different Arterial Path Length Measurements

PubMed Central

Sugawara, Jun; Hayashi, Koichiro; Yokoi, Takashi; Tanaka, Hirofumi

2009-01-01

Background Carotid-femoral pulse wave velocity (PWV) is the most established index of arterial stiffness. Yet there is no consensus on the methodology in regard to the arterial path length measurements conducted on the body surface. Currently, it is not known to what extent the differences in the arterial path length measurements affect absolute PWV values. Methods Two hundred fifty apparently healthy adults (127 men and 123 women, 19-79 years) were studied. Carotid-femoral PWV was calculated using (1) the straight distance between carotid and femoral sites (PWVcar–fem), (2) the straight distance between suprasternal notch and femoral site minus carotid arterial length (PWV(ssn–fem)-(ssn–car)), (3) the straight distance between carotid and femoral sites minus carotid arterial length (PWV(car–fem)-(ssn–car)), and (4) the combined distance from carotid site to the umbilicus and from the umbilicus to femoral site minus carotid arterial length (PWV(ssn–umb–fem)-(ssn–car)). Results All the calculated PWV were significantly correlated with each other (r=0.966-0.995). PWV accounting for carotid arterial length were 16-31% lower than PWVcar–fem. PWVcar–fem value of 12 m/sec corresponded to 8.3 m/sec for PWV(ssn–fem)-(ssn–car), 10.0 m/sec for PWV(car–fem)-(ssn–car), and 8.9 m/sec for PWV(ssn–umb–fem)-(ssn–car). Conclusion Different body surface measurements used to estimate arterial path length would produce substantial variations in absolute PWV values. PMID:20396400

Reversal modes in FeCoNi nanowire arrays: Correlation between magnetostatic interactions and nanowires length

NASA Astrophysics Data System (ADS)

Samanifar, S.; Almasi Kashi, M.; Ramazani, A.; Alikhani, M.

2015-03-01

FeCoNi nanowire arrays (175 nm in diameter and lengths ranging from 5 to 40 μm) were fabricated into nanopores of hard-anodized aluminum oxide templates using pulsed ac electrodeposition technique. Increasing the length had no considerable effect on the composition and crystalline characteristics of Fe47Co38Ni15 nanowires (NWs). By eliminating the dendrites formed at the bottom of the pores, we report a careful investigation on the effect of magnetostatic interactions on magnetic properties and the effect of nanowire length on reversal modes. Hysteresis loop measurements indicated that increasing the length decreases coercivity and squareness values. On the other hand, first-order reversal curve measurements show a linear correlation between the magnetostatic interactions and length of NWs. Comparing reversal modes of the NWs both experimentally and theoretically using angular dependence of coercivity, we find that when L≤22 μm, a vortex domain wall mode is only occurred. When L>22 μm, a non-monotonic behavior indicates a transition from the vortex to transverse domain wall propagation. As a result, a critical length was found above which the transition between the reversal modes is occurred due the enhanced interactions. The transition angle also shifts toward a lower angle as the length increases. Moreover, with increasing length from 22 to 31 μm, the single domain structure of NWs changes to a pseudo single domain state. A multidomain-like behavior is also found for the longest NWs length.

Measuring digit lengths with 3D digital stereophotogrammetry: A comparison across methods.

PubMed

Gremba, Allison; Weinberg, Seth M

2018-05-09

We compared digital 3D stereophotogrammetry to more traditional measurement methods (direct anthropometry and 2D scanning) to capture digit lengths and ratios. The length of the second and fourth digits was measured by each method and the second-to-fourth ratio was calculated. For each digit measurement, intraobserver agreement was calculated for each of the three collection methods. Further, measurements from the three methods were compared directly to one another. Agreement statistics included the intraclass correlation coefficient (ICC) and technical error of measurement (TEM). Intraobserver agreement statistics for the digit length measurements were high for all three methods; ICC values exceeded 0.97 and TEM values were below 1 mm. For digit ratio, intraobserver agreement was also acceptable for all methods, with direct anthropometry exhibiting lower agreement (ICC = 0.87) compared to indirect methods. For the comparison across methods, the overall agreement was high for digit length measurements (ICC values ranging from 0.93 to 0.98; TEM values below 2 mm). For digit ratios, high agreement was observed between the two indirect methods (ICC = 0.93), whereas indirect methods showed lower agreement when compared to direct anthropometry (ICC < 0.75). Digit measurements and derived ratios from 3D stereophotogrammetry showed high intraobserver agreement (similar to more traditional methods) suggesting that landmarks could be placed reliably on 3D hand surface images. While digit length measurements were found to be comparable across all three methods, ratios derived from direct anthropometry tended to be higher than those calculated indirectly from 2D or 3D images. © 2018 Wiley Periodicals, Inc.

Measurements of the Influence of Integral Length Scale on Stagnation Region Heat Transfer

NASA Technical Reports Server (NTRS)

Vanfossen, G. James; Ching, Chang Y.

1994-01-01

The purpose was twofold: first, to determine if a length scale existed that would cause the greatest augmentation in stagnation region heat transfer for a given turbulence intensity and second, to develop a prediction tool for stagnation heat transfer in the presence of free stream turbulence. Toward this end, a model with a circular leading edge was fabricated with heat transfer gages in the stagnation region. The model was qualified in a low turbulence wind tunnel by comparing measurements with Frossling's solution for stagnation region heat transfer in a laminar free stream. Five turbulence generating grids were fabricated; four were square mesh, biplane grids made from square bars. Each had identical mesh to bar width ratio but different bar widths. The fifth grid was an array of fine parallel wires that were perpendicular to the axis of the cylindrical leading edge. Turbulence intensity and integral length scale were measured as a function of distance from the grids. Stagnation region heat transfer was measured at various distances downstream of each grid. Data were taken at cylinder Reynolds numbers ranging from 42,000 to 193,000. Turbulence intensities were in the range 1.1 to 15.9 percent while the ratio of integral length scale to cylinder diameter ranged from 0.05 to 0.30. Stagnation region heat transfer augmentation increased with decreasing length scale. An optimum scale was not found. A correlation was developed that fit heat transfer data for the square bar grids to within +4 percent. The data from the array of wires were not predicted by the correlation; augmentation was higher for this case indicating that the degree of isotropy in the turbulent flow field has a large effect on stagnation heat transfer. The data of other researchers are also compared with the correlation.

Pressure and Flow Rate Changes During Contrast Injections in Cerebral Angiography: Correlation to Reflux Length.

PubMed

Kovarovic, Brandon; Woo, Henry H; Fiorella, David; Lieber, Baruch B; Sadasivan, Chander

2018-03-01

Cerebral angiography involves the antegrade injection of contrast media through a catheter into the vasculature to visualize the region of interest under X-ray imaging. Depending on the injection and blood flow parameters, the bolus of contrast can propagate in the upstream direction and proximal to the catheter tip, at which point contrast is said to have refluxed. In this in vitro study, we investigate the relationship of fundamental hemodynamic variables to this phenomenon. Contrast injections were carried out under steady and pulsatile flow using various vessel diameters, catheter sizes, working fluid flow rates, and injection rates. The distance from the catheter tip to the proximal edge of the contrast bolus, called reflux length, was measured on the angiograms; the relation of this reflux length to different hemodynamic parameters was evaluated. Results show that contrast reflux occurs when the pressure distal to the catheter tip increases to be greater than the pressure proximal to the catheter tip. The ratio of this pressure difference to the baseline flow rate, called reflux resistance here, was linearly correlated to the normalized reflux length (reflux length/vessel diameter). Further, the ratio of blood flow to contrast fluid momentums, called the Craya-Curtet number, was correlated to the normalized reflux length via a sigmoid function. A sigmoid function was also found to be representative of the relationship between the ratio of the Reynolds numbers of blood flow to contrast and the normalized reflux length. As described by previous reports, catheter based contrast injections cause substantial increases in local flow and pressure. Contrast reflux should generally be avoided during standard antegrade angiography. Our study shows two specific correlations between contrast reflux length and baseline and intra-injection parameters that have not been published previously. Further studies need to be conducted to fully characterize the phenomena and to

Inflatable penile prosthesis implant length with baseline characteristic correlations: preliminary analysis of the PROPPER study

PubMed Central

Henry, Gerard; Karpman, Edward; Brant, William; Jones, LeRoy; Khera, Mohit; Kohler, Tobias; Christine, Brian; Rhee, Eugene; Kansas, Bryan; Bella, Anthony J.

2017-01-01

Background “Prospective Registry of Outcomes with Penile Prosthesis for Erectile Restoration” (PROPPER) is a large, multi-institutional, prospective clinical study to collect, analyze, and report real-world outcomes for men implanted with penile prosthetic devices. We prospectively correlated co-morbid conditions and demographic data with implanted penile prosthesis size to enable clinicians to better predict implanted penis size following penile implantation. We present many new data points for the first time in the literature and postulate that radical prostatectomy (RP) is negatively correlated with penile corporal length. Methods Patient demographics, medical history, baseline characteristics and surgical details were compiled prospectively. Pearson correlation coefficient was generated for the correlation between demographic, etiology of ED, duration of ED, co-morbid conditions, pre-operative penile length (flaccid and stretched) and length of implanted penile prosthesis. Multivariate analysis was performed to define predictors of implanted prosthesis length. Results From June 2011 to June 2017, 1,135 men underwent primary implantation of penile prosthesis at a total of 11 study sites. Malleable (Spectra), 2-piece Ambicor, and 3-piece AMS 700 CX/LGX were included in the analysis. The most common patient comorbidities were CV disease (26.1%), DM (11.1%), and PD (12.4%). Primary etiology of ED: RP (27.4%), DM (20.3%), CVD (18.0%), PD (10.3%), and Priapism (1.4%), others (22.6%). Mean duration of ED is 6.2¡À4.1 years. Implant length was weakly negatively correlated with White/Caucasian (r=−0.18; P<0.01), history of RP (r=−0.13; P<0.01), PD as comorbidity (r=−0.16; P<0.01), venous leak (r=−0.08; P<0.01), and presence of stress incontinence (r=−0.13; P<0.01). Analyses showed weak positive correlations with Black/AA (r=0.32; P<0.01), CV disease as primary ED etiology (r=0.08; P<0.01) and pre-operative stretched penile length (r=0.18; P<0.01). There

Two- and three-dimensional CT measurements of urinary calculi length and width: a comparative study.

PubMed

Lidén, Mats; Thunberg, Per; Broxvall, Mathias; Geijer, Håkan

2015-04-01

The standard imaging procedure for a patient presenting with renal colic is unenhanced computed tomography (CT). The CT measured size has a close correlation to the estimated prognosis for spontaneous passage of a ureteral calculus. Size estimations of urinary calculi in CT images are still based on two-dimensional (2D) reformats. To develop and validate a calculus oriented three-dimensional (3D) method for measuring the length and width of urinary calculi and to compare the calculus oriented measurements of the length and width with corresponding 2D measurements obtained in axial and coronal reformats. Fifty unenhanced CT examinations demonstrating urinary calculi were included. A 3D symmetric segmentation algorithm was validated against reader size estimations. The calculus oriented size from the segmentation was then compared to the estimated size in axial and coronal 2D reformats. The validation showed 0.1 ± 0.7 mm agreement against reference measure. There was a 0.4 mm median bias for 3D estimated calculus length compared to 2D (P < 0.001), but no significant bias for 3D width compared to 2D. The length of a calculus in axial and coronal reformats becomes underestimated compared to 3D if its orientation is not aligned to the image planes. Future studies aiming to correlate calculus size with patient outcome should use a calculus oriented size estimation. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Stability of measures from children's interviews: the effects of time, sample length, and topic.

PubMed

Heilmann, John; DeBrock, Lindsay; Riley-Tillman, T Chris

2013-08-01

The purpose of this study was to examine the reliability of, and sources of variability in, language measures from interviews collected from young school-age children. Two 10-min interviews were collected from 20 at-risk kindergarten children by an examiner using a standardized set of questions. Test-retest reliability coefficients were calculated for 8 language measures. Generalizability theory (G-theory) analyses were completed to document the variability introduced into the measures from the child, session, sample length, and topic. Significant and strong reliability correlation coefficients were observed for most of the language sample measures. The G-theory analyses revealed that most of the variance in the language measures was attributed to the child. Session, sample length, and topic accounted for negligible amounts of variance in most of the language measures. Measures from interviews were reliable across sessions, and the sample length and topic did not have a substantial impact on the reliability of the language measures. Implications regarding the clinical feasibility of language sample analysis for assessment and progress monitoring are discussed.

Distance and Cable Length Measurement System

PubMed Central

Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

2009-01-01

A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

Different behaviour-body length correlations in two populations of juvenile three-spined stickleback (Gasterosteus aculeatus).

PubMed

De Winter, Gunnar; Martins, Henrique Ramalho; Trovo, Rafael Arnoni; Chapman, Ben B

2016-01-01

Behavioural variation among individuals has received a lot of attention by behavioural ecologists in the past few years. Its causes and consequences are becoming vast areas of research. The origin and maintenance of individual variation in behaviour within and among populations is affected by many facets of the biotic and abiotic environment. Here, two populations of lab-reared juvenile three-spined sticklebacks (Gasterosteus aculeatus) are tested for three behaviours (boldness, exploration, and sociability). Given the identical rearing conditions, the only difference between these populations is the parental habitat. In both populations, correlations between behaviour and body length are found. Interestingly, these differ between the populations. In one population body length was negatively correlated with exploratory behaviour, while in the other one body length correlated negatively with sociability. Considering the identical environment these juvenile fish were exposed to, these findings suggest a potential (epi)genetic foundation for these correlations and shows that, in three-spined sticklebacks, the proximate basis for correlations between body length and behaviour appears quite malleable. Copyright © 2015 Elsevier B.V. All rights reserved.

[Renal length measured by ultrasound in adult mexican population].

PubMed

Oyuela-Carrasco, J; Rodríguez-Castellanos, F; Kimura, E; Delgado-Hernández, R; Herrera-Félix, J P

2009-01-01

Renal length estimation by ultrasound is an important parameter in clinical evaluation of kidney disease and healthy donors. Changes in renal volume may be a sign of kidney disease. Correct interpretation of renal length requires the knowledge of normal limits, these have not been described for Latin American population. To describe normal renal length (RL) by ultrasonography in a group of Mexican adults. Ultrasound measure of RL in 153 healthy Mexican adults stratified by age. Describe the association of RL to several anthropometric variables. A total of 77 males and 76 females were scanner. The average age for the group was 44.12 +/- 15.44 years. The mean weight, body mass index (BMI) and height were 68.87 +/- 11.69 Kg, 26.77 +/- 3.82 kg/m2 and 160 +/- 8.62 cm respectively. Dividing the population by gender, showed a height of 166 +/- 6.15 cm for males and 154.7 +/- 5.97 cm for females (p =0.000). Left renal length (LRL) in the whole group was 105.8 +/- 7.56 mm and right renal length (RRL) was 104.3 +/- 6.45 mm (p = 0.000.) The LRL for males was 107.16 +/- 6.97 mm and for females was 104.6 +/- 7.96 mm. The average RRL for males was 105.74 +/- 5.74 mm and for females 102.99 +/- 6.85 mm (p = 0.008.) We noted that RL decreased with age and the rate of decline accelerates alter 60 years of age. Both lengths correlated significantly and positively with weight, BMI and height. The RL was significantly larger in males than in females in both kidneys (p = 0.036) in this Mexican population. Renal length declines after 60 years of age and specially after 70 years.

PBMC telomerase activity, but not leukocyte telomere length, correlates with hippocampal volume in major depression

PubMed Central

Wolkowitz, Owen M.; Mellon, Synthia H.; Lindqvist, Daniel; Epel, Elissa S.; Blackburn, Elizabeth H.; Lin, Jue; Reus, Victor I.; Burke, Heather; Rosser, Rebecca; Mahan, Laura; Mackin, Scott; Yang, Tony; Weiner, Michael; Mueller, Susanne

2015-01-01

Accelerated cell aging, indexed in peripheral leukocytes by telomere length and in peripheral blood mononuclear cells (PBMCs) by telomerase activity, has been reported in several studies of major depressive disorder (MDD). However, the relevance of these peripheral measures for brain indices that are presumably more directly related to MDD pathophysiology is unknown. In this study, we explored the relationship between PBMC telomerase activity and leukocyte telomere length and magnetic resonance imaging-estimated hippocampal volume in un-medicated depressed individuals and healthy controls. We predicted that, to the extent peripheral and central telomerase activity are directly related, PBMC telomerase activity would be positively correlated with hippocampal volume, perhaps due to hippocampal telomerase-associated neurogenesis, neuroprotection or neurotrophic facilitation, and that this effect would be clearer in individuals with increased PBMC telomerase activity, as previously reported in un-medicated MDD. We did not have specific hypotheses regarding the relationship between leukocyte telomere length and hippocampal volume, due to conflicting reports in the published literature. We found, in 25 un-medicated MDD subjects, that PBMC telomerase activity was significantly positively correlated with hippocampal volume; this relationship was not observed in 18 healthy controls. Leukocyte telomere length was not significantly related to hippocampal volume in either group (19 unmedicated MDD subjects and 17 healthy controls). Although the nature of the relationship between peripheral telomerase activity and telomere length and the hippocampus is unclear, these preliminary data are consistent with the possibility that PBMC telomerase activity indexes, and may provide a novel window into, hippocampal neuroprotection and/or neurogenesis in MDD. PMID:25773002

Correlation of cord blood telomere length with birth weight.

PubMed

Lee, Siew-Peng; Hande, Prakash; Yeo, George Sh; Tan, Ene-Choo

2017-09-08

Intrauterine growth restriction affects 3% of newborns; and the lightest 10% of whom are classified as small for gestational age (SGA). These low-birth weight newborns are at increased risk of neonatal morbidity such as hypoxia and hypoglycaemia. In later life, they are at higher risk of several age-related diseases such as cardiovascular and metabolic disorders and dementia. As having short telomeres is also associated with these diseases, we tested if these newborns might already start with shorter telomeres at birth. Relative telomere lengths were determined using quantitative real-time PCR in cord blood samples from 195 newborns of Chinese ancestry. Based on the telomere length normalised to a single copy gene and a reference DNA sample as internal control, we found statistically significant correlations between relative telomere length and both unadjusted and gestational age-adjusted birth weight, with the lighter newborns having shorter telomeres. The SGA birth weight group comprising the bottom 10% of the samples also had the shortest telomeres compared to the medium and heaviest birth weight groups. Our results indicate that there is reduction of cord blood telomere length for newborns with lower birth weight.

Effects of energy chirp on bunch length measurement in linear accelerator beams

NASA Astrophysics Data System (ADS)

Sabato, L.; Arpaia, P.; Giribono, A.; Liccardo, A.; Mostacci, A.; Palumbo, L.; Vaccarezza, C.; Variola, A.

2017-08-01

The effects of assumptions about bunch properties on the accuracy of the measurement method of the bunch length based on radio frequency deflectors (RFDs) in electron linear accelerators (LINACs) are investigated. In particular, when the electron bunch at the RFD has a non-negligible energy chirp (i.e. a correlation between the longitudinal positions and energies of the particle), the measurement is affected by a deterministic intrinsic error, which is directly related to the RFD phase offset. A case study on this effect in the electron LINAC of a gamma beam source at the Extreme Light Infrastructure-Nuclear Physics (ELI-NP) is reported. The relative error is estimated by using an electron generation and tracking (ELEGANT) code to define the reference measurements of the bunch length. The relative error is proved to increase linearly with the RFD phase offset. In particular, for an offset of {{7}\\circ} , corresponding to a vertical centroid offset at a screen of about 1 mm, the relative error is 4.5%.

Systematic correlation of environmental exposure and physiological and self-reported behaviour factors with leukocyte telomere length.

PubMed

Patel, Chirag J; Manrai, Arjun K; Corona, Erik; Kohane, Isaac S

2017-02-01

It is hypothesized that environmental exposures and behaviour influence telomere length, an indicator of cellular ageing. We systematically associated 461 indicators of environmental exposures, physiology and self-reported behaviour with telomere length in data from the US National Health and Nutrition Examination Survey (NHANES) in 1999-2002. Further, we tested whether factors identified in the NHANES participants are also correlated with gene expression of telomere length modifying genes. We correlated 461 environmental exposures, behaviours and clinical variables with telomere length, using survey-weighted linear regression, adjusting for sex, age, age squared, race/ethnicity, poverty level, education and born outside the USA, and estimated the false discovery rate to adjust for multiple hypotheses. We conducted a secondary analysis to investigate the correlation between identified environmental variables and gene expression levels of telomere-associated genes in publicly available gene expression samples. After correlating 461 variables with telomere length, we found 22 variables significantly associated with telomere length after adjustment for multiple hypotheses. Of these varaibales, 14 were associated with longer telomeres, including biomarkers of polychlorinated biphenyls([PCBs; 0.1 to 0.2 standard deviation (SD) increase for 1 SD increase in PCB level, P  < 0.002] and a form of vitamin A, retinyl stearate. Eight variables associated with shorter telomeres, including biomarkers of cadmium, C-reactive protein and lack of physical activity. We could not conclude that PCBs are correlated with gene expression of telomere-associated genes. Both environmental exposures and chronic disease-related risk factors may play a role in telomere length. Our secondary analysis found no evidence of association between PCBs/smoking and gene expression of telomere-associated genes. All correlations between exposures, behaviours and clinical factors and changes in

Length and Dimensional Measurements at NIST

PubMed Central

Swyt, Dennis A.

2001-01-01

This paper discusses the past, present, and future of length and dimensional measurements at NIST. It covers the evolution of the SI unit of length through its three definitions and the evolution of NBS-NIST dimensional measurement from early linescales and gage blocks to a future of atom-based dimensional standards. Current capabilities include dimensional measurements over a range of fourteen orders of magnitude. Uncertainties of measurements on different types of material artifacts range down to 7×10−8 m at 1 m and 8 picometers (pm) at 300 pm. Current work deals with a broad range of areas of dimensional metrology. These include: large-scale coordinate systems; complex form; microform; surface finish; two-dimensional grids; optical, scanning-electron, atomic-force, and scanning-tunneling microscopies; atomic-scale displacement; and atom-based artifacts. PMID:27500015

The Association of Visit Length and Measures of Patient-Centered Communication in HIV Care

PubMed Central

Epstein, Lauren; Lee, Yoojin; Rogers, William; Beach, Mary Catherine; Wilson, Ira B.

2011-01-01

Introduction Patient centered clinical communication may be associated with longer encounters. Methods We used the General Medical Interaction Analysis System (GMIAS) to code transcripts of routine outpatient visits in HIV care, and create 5 measures of patient-centeredness. We defined visit length as number of utterances. To better understand properties of encounters reflected in these measures, we conducted a qualitative analysis of the 15 longest and 15 shortest visits. Results All 5 measures were significantly associated with visit length (P<.05, rank order correlations .21 to .44). In multivariate regressions, association of patient centeredness with visit length was attenuated for 4 measures, and increased for 1; two were no longer statistically significant (p>0.05). Black and Hispanic race were associated with shorter visits compared with white race. Some of the longest visits featured content that could be considered extraneous to appropriate care. Conclusion Patient centeredness is weakly related to visit length, but may reflect inefficient use of time in long encounters. Practice Implications Efforts to make visits more patient centered should focus on improving dialogue quality and efficient use of time, not on making visits longer. Shorter visits for Black and Hispanic patients could contribute to health disparities related to race and ethnicity. PMID:21592716

Admission Norton scale scores (ANSS) correlate with rehabilitation outcome and length in elderly patients following hip arthroplasty.

PubMed

Justo, Dan; Vislapu, Natalia; Shvedov, Victor; Fickte, Marina; Danylesko, Alexander; Kimelman, Polina; Merdler, Charlotte; Lerman, Yaffa

2011-01-01

We sought to determine if ANSS used for evaluating pressure sore risk also correlate with rehabilitation outcome and length following hip arthroplasty in elderly patients. This was a retrospective study conducted in a geriatric rehabilitation department during 2009. ANSS, admission albumin serum levels, mini-mental state examination (MMSE) scores, discharge walking functional independence measure (FIM) scores, and rehabilitation length were studied. The final cohort included 201 patients: 160 (79.6%) females and 41 (20.4%) males. Mean age was 82.7±6.5 years. Mean discharge walking FIM score was 5.2±0.9. Mean length of rehabilitation was 19.9±7.8 days. ANSS correlated with discharge walking FIM scores (r=0.28; p=0.002), and with length of rehabilitation (r=-0.22; p=0.014) following adjustment for age, admission albumin serum levels, and MMSE scores. Linear regression analysis showed that ANSS were associated with the discharge walking FIM scores (p<0.0001) and rehabilitation length (p=0.027) independent of age, admission albumin serum levels, gender, type of hip surgery, and the appearance of pressure sores. We conclude that the Norton scoring system may be used for predicting the outcome and the duration of rehabilitation in elderly patients following hip arthroplasty. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

In vivo fascicle length measurements via B-mode ultrasound imaging with single vs dual transducer arrangements.

PubMed

Brennan, Scott F; Cresswell, Andrew G; Farris, Dominic J; Lichtwark, Glen A

2017-11-07

Ultrasonography is a useful technique to study muscle contractions in vivo, however larger muscles like vastus lateralis may be difficult to visualise with smaller, commonly used transducers. Fascicle length is often estimated using linear trigonometry to extrapolate fascicle length to regions where the fascicle is not visible. However, this approach has not been compared to measurements made with a larger field of view for dynamic muscle contractions. Here we compared two different single-transducer extrapolation methods to measure VL muscle fascicle length to a direct measurement made using two synchronised, in-series transducers. The first method used pennation angle and muscle thickness to extrapolate fascicle length outside the image (extrapolate method). The second method determined fascicle length based on the extrapolated intercept between a fascicle and the aponeurosis (intercept method). Nine participants performed maximal effort, isometric, knee extension contractions on a dynamometer at 10° increments from 50 to 100° of knee flexion. Fascicle length and torque were simultaneously recorded for offline analysis. The dual transducer method showed similar patterns of fascicle length change (overall mean coefficient of multiple correlation was 0.76 and 0.71 compared to extrapolate and intercept methods respectively), but reached different absolute lengths during the contractions. This had the effect of producing force-length curves of the same shape, but each curve was shifted in terms of absolute length. We concluded that dual transducers are beneficial for studies that examine absolute fascicle lengths, whereas either of the single transducer methods may produce similar results for normalised length changes, and repeated measures experimental designs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measurement of clavicular length and shortening after a midshaft clavicular fracture: Spatial digitization versus planar roentgen photogrammetry.

PubMed

Stegeman, Sylvia A; de Witte, Pieter Bas; Boonstra, Sjoerd; de Groot, Jurriaan H; Nagels, Jochem; Krijnen, Pieta; Schipper, Inger B

2016-08-01

Clavicular shortening after fracture is deemed prognostic for clinical outcome and is therefore generally assessed on radiographs. It is used for clinical decision making regarding operative or non-operative treatment in the first 2weeks after trauma, although the reliability and accuracy of the measurements are unclear. This study aimed to assess the reliability of roentgen photogrammetry (2D) of clavicular length and shortening, and to compare these with 3D-spatial digitization measurements, obtained with an electromagnetic recording system (Flock of Birds). Thirty-two participants with a consolidated non-operatively treated two or multi-fragmented dislocated midshaft clavicular fracture were analysed. Two observers measured clavicular lengths and absolute and proportional clavicular shortening on radiographs taken before and after fracture consolidation. The clavicular lengths were also measured with spatial digitization. Inter-observer agreement on the radiographic measurements was assessed using the Intraclass Correlation Coefficient (ICC). Agreement between the radiographic and spatial digitization measurements was assessed using a Bland-Altman plot. The inter-observer agreement on clavicular length, and absolute and proportional shortening on trauma radiographs was almost perfect (ICC>0.90), but moderate for absolute shortening after consolidation (ICC=0.45). The Bland-Altman plot compared measurements of length on AP panorama radiographs with spatial digitization and showed that planar roentgen photogrammetry resulted in up to 37mm longer and 34mm shorter measurements than spatial digitization. Measurements of clavicular length on radiographs are highly reliable between observers, but may not reflect the actual length and shortening of the clavicle when compared to length measurements with spatial digitization. We recommend to use proportional shortening when measuring clavicular length or shortening on radiographs for clinical decision making. Copyright �

From Concrete to Abstract in the Measurement of Length

NASA Astrophysics Data System (ADS)

Stephanou, Andreas; Fisher, William P., Jr.

2013-09-01

The concatenation of units of length is widely viewed as the paradigmatic expression of fundamental measurement. Survey, assessment, and test scores in educational and psychological measurement are often interpreted in ways that assume a concatenation of units to have been established, even though these assumptions are rarely stated or tested. A concatenation model for measurement is shown to be equivalent to a Rasch model: any two units of measurement placed end to end must together be of the same length as either one of them added to itself. This additive principle and a concatenation model of measurement together serve as a heuristic guide for organizing two experimental approaches to calibrating instruments for measuring length. The capacity to reproduce the unit of measurement from theory with no need for repeated empirical calibration experiments, as in the geometrical bisection of the line and the resultant halving of the length measure, is highlighted as essential to demonstrating a thorough understanding of the construct.

Correlation and agreement of a digital and conventional method to measure arch parameters.

PubMed

Nawi, Nes; Mohamed, Alizae Marny; Marizan Nor, Murshida; Ashar, Nor Atika

2018-01-01

The aim of the present study was to determine the overall reliability and validity of arch parameters measured digitally compared to conventional measurement. A sample of 111 plaster study models of Down syndrome (DS) patients were digitized using a blue light three-dimensional (3D) scanner. Digital and manual measurements of defined parameters were performed using Geomagic analysis software (Geomagic Studio 2014 software, 3D Systems, Rock Hill, SC, USA) on digital models and with a digital calliper (Tuten, Germany) on plaster study models. Both measurements were repeated twice to validate the intraexaminer reliability based on intraclass correlation coefficients (ICCs) using the independent t test and Pearson's correlation, respectively. The Bland-Altman method of analysis was used to evaluate the agreement of the measurement between the digital and plaster models. No statistically significant differences (p > 0.05) were found between the manual and digital methods when measuring the arch width, arch length, and space analysis. In addition, all parameters showed a significant correlation coefficient (r ≥ 0.972; p < 0.01) between all digital and manual measurements. Furthermore, a positive agreement between digital and manual measurements of the arch width (90-96%), arch length and space analysis (95-99%) were also distinguished using the Bland-Altman method. These results demonstrate that 3D blue light scanning and measurement software are able to precisely produce 3D digital model and measure arch width, arch length, and space analysis. The 3D digital model is valid to be used in various clinical applications.

Modification of cervical length after cervical pessary insertion: correlation weeks of gestation.

PubMed

Mendoza, Manel; Goya, Maria; Gascón, Andrea; Pratcorona, Laia; Merced, Carme; Rodó, Carlota; Valle, Leonor; Romero, Azahar; Juan, Miquel; Rodríguez, Alberto; Muñoz, Begoña; Santacruz, Bele N; Carreras, Elena; Cabero, Luis

2017-07-01

To observe the modifications in cervical length (CL) in patients with and without cervical pessary (Arabin® ASQ 65/25/32) and correlate these modifications with gestational age at delivery. Prospective study of asymptomatic singleton pregnancies (PECEP-Trial) between weeks 20 + 0 and 23 + 6 with maternal short cervix (<25 mm) randomised into two groups: expectant management and cervical pessary. This study included 380 pregnant women: 190 with pessary and 190 without pessary. Mean CL in both groups at the time of randomisation showed no statistically-significant differences (pessary group: 19.0 mm and management group: 19.0 mm; p = 0.9). Mean CL measured after randomisation was 15.4 mm in patients of the expectant management group and 21.5 mm in the pessary group. These differences were statistically significant (p < 0.0001). When means at randomisation and at the second measurement were compared, CL had decreased by 3.6 mm in the expectant management group and increased by 2.6 mm in the pessary group; this difference was statistically significant (p < 0.0001). Coefficients of correlation showed that among patients of both groups with the same CL at 20 weeks of gestation, those with a pessary gave birth later. Insertion of an Arabin cervical pessary increased CL in asymptomatic patients with a short cervix, which correlated with shorter gestational age at delivery. The cervical pessary halted the progressive decrease in CL, which correlated with longer gestational age at delivery.

Concordance and interchangeability of biometric measurements of ocular axial length in patients awaiting cataract surgery.

PubMed

Martín-Serrano, María José; Roman-Ortiz, Carmen; Villa-Sáez, M Luz; Labrador-Castellanos, M Purificación; Blanco-Carrasco, Rosario; Lozano-Ballesteros, Felicidad; Pedraza-Martín, Carmen; José-Herrero, M Teresa San; López-Ropero, Ana M; Tenías Burillo, José María

2014-01-01

To estimate in patients awaiting cataract surgery the concordance and interchangeability of axial eye length measurements performed with the aid of various biometric methods (optical or ultrasonic) by different operators (nurses) at different times during the period prior to surgery. We selected 182 consecutive eyes from 91 patients.Ocular axial length was measured with the aid of 2 methods (IOLMaster® and Ocuscan®) by 9 randomly allocated technicians at 2 different times during the waiting period. The concordance between measurements was evaluated by means of the intraclass correlation coefficient (ICC); the interchangeability of the results was assessed with Bland Altman plots and Passing and Bablok regression. The measurements were consistent between biometric methods (ICC 0.975, 95% confidence interval [CI] 0.968 to 0.980) and measurement dates (ICC 0.996, 95% CI 0.995 to 0.997). Interobserver agreement was more heterogeneous (ICC range 0.844 to 0.998). No systematic errors were observed among the various biometric methods and measurement dates. Because measurement of axial length in phakic patients may be technician-dependent, the technician's experience should be noted in the protocols of ophthalmology services.

Validity of plant fiber length measurement : a review of fiber length measurement based on kenaf as a model

Treesearch

James S. Han; Theodore Mianowski; Yi-yu Lin

1999-01-01

The efficacy of fiber length measurement techniques such as digitizing, the Kajaani procedure, and NIH Image are compared in order to determine the optimal tool. Kenaf bast fibers, aspen, and red pine fibers were collected from different anatomical parts, and the fiber lengths were compared using various analytical tools. A statistical analysis on the validity of the...

Association between objectively measured physical activity, chronic stress and leukocyte telomere length.

PubMed

von Känel, Roland; Bruwer, Erna J; Hamer, Mark; de Ridder, J Hans; Malan, Leoné

2017-10-01

Physical activity (PA) attenuates chronic stress and age-related and cardiovascular disease risks, whereby potentially slowing telomere shortening. We aimed to study the association between seven-day objectively measured habitual PA, chronic stress and leukocyte telomere length. Study participants were African (N.=96) and Caucasian (N.=107) school teachers of the Sympathetic activity and Ambulatory Blood Pressure in Africans study. All lifestyle characteristics (including PA) were objectively measured. The general health questionnaire and serum cortisol were assessed as psychological and physical measures of chronic stress. Leukocyte telomere length was measured using the quantitative real-time polymerase chain reaction. Africans had significantly shorter telomeres (P<.0001) and greater psychological distress (P=0.001) than Caucasians, whereas no group difference was seen for cortisol levels. Higher age (ß=-0.28 [-0.40, -0.16, P≤0.000), higher alcohol consumption (ß=-0.21 [-0.36, -0.08], P=0.003) and increased central obesity (ß=-0.17 [-0.30, -0.03], P=0.017) were all significantly associated with shorter telomeres. Habitual PA of different intensity was not significantly associated with markers of chronic stress or telomere length. However, more time spent with light intensity PA time was significantly and independently correlated with lower waist circumference (r=-0.21, P=0.004); in turn, greater waist circumference was significantly associated shorter telomeres (β=-0.17 [-0.30, -0.03], P=0.017). Habitual PA of different intensity was not directly associated with markers of chronic stress and leukocyte telomere length in this biethnic cohort. However, our findings suggest that light intensity PA could contribute to lowered age-related disease risk and healthy ageing by facilitating maintenance of a normal waist circumference.

Establishment of a Method to Measure Length of the Ulnar Nerve and Standardize F-wave Values in Clinically Normal Beagles

PubMed Central

HIRASAWA, Shun; SHIMIZU, Miki; MARUI, Yuumi; KISHIMOTO, Miori; OKUNO, Seiichi

2014-01-01

We designed a new method of measuring the length of the ulnar nerve and determining standard values for F-wave parameters of the ulnar nerve in clinically normal beagles. Nerve length must be precisely measured to determine F-wave latency and conduction velocity. The length of the forelimb has served as the length of the ulnar nerve for F-wave assessments, but report indicates that F-wave latency is proportional to the length of the pathway traveled by nerve impulses. Therefore, we measured the surface distance from a stimulus point to the spinous process of the first thoracic vertebra (nerve length 1) and the anterior horn of the scapula (nerve length 2) as landmarks through the olecranon and the shoulder blade acromion. The correlation coefficients between the shortest F-wave latency and the length of nerves 1, 2 or the forelimb were 0.61, 0.7 and 0.58. Nerve length 2 generated the highest value. Furthermore, the anterior horn of the scapula was easily palpated in any dog regardless of well-fed body. We concluded that nerve length 2 was optimal for measuring the length of the ulnar nerve. PMID:25649942

On the correlation between bond-length change and vibrational frequency shift in halogen-bonded complexes

NASA Astrophysics Data System (ADS)

Wang, Weizhou; Zhang, Yu; Ji, Baoming; Tian, Anmin

2011-06-01

The C-Hal (Hal = Cl, Br, or I) bond-length change and the corresponding vibrational frequency shift of the C-Hal stretch upon the C-Hal ⋯Y (Y is the electron donor) halogen bond formation have been determined by using density functional theory computations. Plots of the C-Hal bond-length change versus the corresponding vibrational frequency shift of the C-Hal stretch all give straight lines. The coefficients of determination range from 0.94366 to 0.99219, showing that the correlation between the C-Hal bond-length change and the corresponding frequency shift is very good in the halogen-bonded complexes. The possible effects of vibrational coupling, computational method, and anharmonicity on the bond-length change-frequency shift correlation are discussed in detail.

Quantum discord length is enhanced while entanglement length is not by introducing disorder in a spin chain.

PubMed

Sadhukhan, Debasis; Roy, Sudipto Singha; Rakshit, Debraj; Prabhu, R; Sen De, Aditi; Sen, Ujjwal

2016-01-01

Classical correlation functions of ground states typically decay exponentially and polynomially, respectively, for gapped and gapless short-range quantum spin systems. In such systems, entanglement decays exponentially even at the quantum critical points. However, quantum discord, an information-theoretic quantum correlation measure, survives long lattice distances. We investigate the effects of quenched disorder on quantum correlation lengths of quenched averaged entanglement and quantum discord, in the anisotropic XY and XYZ spin glass and random field chains. We find that there is virtually neither reduction nor enhancement in entanglement length while quantum discord length increases significantly with the introduction of the quenched disorder.

Quark ensembles with the infinite correlation length

NASA Astrophysics Data System (ADS)

Zinov'ev, G. M.; Molodtsov, S. V.

2015-01-01

A number of exactly integrable (quark) models of quantum field theory with the infinite correlation length have been considered. It has been shown that the standard vacuum quark ensemble—Dirac sea (in the case of the space-time dimension higher than three)—is unstable because of the strong degeneracy of a state, which is due to the character of the energy distribution. When the momentum cutoff parameter tends to infinity, the distribution becomes infinitely narrow, leading to large (unlimited) fluctuations. Various vacuum ensembles—Dirac sea, neutral ensemble, color superconductor, and BCS state—have been compared. In the case of the color interaction between quarks, the BCS state has been certainly chosen as the ground state of the quark ensemble.

Can insertion length for a double-lumen endobronchial tube be predicted?

PubMed

Dyer, R A; Heijke, S A; Russell, W J; Bloch, M B; James, M F

2000-12-01

It has been suggested that the appropriate length of insertion for double-lumen tubes can be estimated by external measurement. This study examined the accuracy of external measurement in estimating the actual length of insertion required in 130 patients. It also examined the relationship between the length inserted and the patient's height in 126 patients and their weight in 125 patients. Although there was a fair correlation between the measured external length and the final inserted length (r = 0.61), the 95% confidence intervals of slope and intercept allowed a large variation and the prediction was too wide to be clinically useful. Height was reasonably well correlated with the final length (r = 0.51) but an equally wide 95% confidence interval rendered it of little clinical value. There was no correlation between weight and final tube length. It is concluded that external measurement alone is not adequate to predict a clinically acceptable position of the double-lumen tube.

Sectional Aluminum Poles Improve Length Measurements in Standing Trees

Treesearch

Joe P. McClure

1968-01-01

The use of sectional aluminum poles to measure lengths in standing trees can reduce bias and improve measurement precision. The method has been tested extensively under a variety of field conditions by Forest Survey crews in the Southeast. Over 16,000 trees with lengths up to 120 feet have been measured over the past 5 years.

[Ultrasonographic evaluation of the uterine cervix length remaining after LOOP-excision].

PubMed

Robert, A-L; Nicolas, F; Lavoué, V; Henno, S; Mesbah, H; Porée, P; Levêque, J

2014-04-01

To assess whether there is a correlation between the length of a conization specimen and the length of the cervix measured by vaginal ultrasonography after the operation Prospective observational study including patients less than 45 years with measurement of cervical length before and the day of the conization, and measuring the histological length of the specimen. Among the 40 patients enrolled, the average ultrasound measurements before conization was 26.9 mm (± 4.9 mm) against 18.1mm (± 4.4mm) after conization with a mean difference of 8.8mm (± 2.4mm) (difference statistically significant P<.0001). The extent of histological specimen was 9 mm (± 2.2mm) on average. A correlation between ultrasound and histological measurements with a correlation coefficient R=0.85 was found statistically significant (P<0.0001). Moreover, the rate of cervix length remove by loop-excision in our series is 33% (± 8.5%). A good correlation between the measurements of the specimen and the cervical ultrasound length before and after conization was found, as a significant reduction in cervical length after conization. The precise length of the specimen should be known in case of pregnancy and the prevention of prematurity due to conization rests on selected indications and efficient surgical technique. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Fiber Length Measurement In Pulp And Paper Industry

NASA Astrophysics Data System (ADS)

Piirainen, Raili A.

1986-10-01

For the pulp and paper maker, product quality and production costs are the major factors that determine profitability. Quality has to be high enough to satisfy the customer and costs low enough to maintain competitiveness. Accurate and readily available fiber length information is fast becoming one of the most important control factors to achieve these targets. Measurement of fiber length has been difficult and time consuming in the past --- appli-cation to production almost impossible due to the historical nature of the data. The Kajaani fiber length analyzer has revolutionized fiber length analysis. Even more accurate than the microscopic method and infinitely faster than mechanical classifiers, such as Bauer McNett or Clark classifiers, the Kajaani analyzer opens new horizons for the paper maker. The Kajaani method is an optical method and is based on the ability of fibers to change the direction of light polarization. With no critical sample preparation, the results are ready in a few minutes. During this time, the analyzer counts and measures over 3000 individual fibers. Results are printed out either in graphic or numerical form. Some of the typical applications of the Kajaani fiber length analyzer are to determine hardwood/softwood ratios in pulp and paper mills both in brownstock and stock preparation areas, to predict strength properties of mechanical pulp based on the fiber length information, to measure the coarseness of the fibers, to evaluate screening and refining processes and to check the quality of purchased pulp.

Correlation of bond strength with surface roughness using a new roughness measurement technique.

PubMed

Winkler, M M; Moore, B K

1994-07-01

The correlation between shear bond strength and surface roughness was investigated using new surface measurement methods. Bonding agents and associated resin composites were applied to set amalgam after mechanically roughening its surface. Surface treatments were noe (as set against glass), 80 grit, and 600 grit abrasive paper. Surface roughness (R(a) as measured parallel and perpendicular (+) to the direction of the polishing scratches and true profile length were measured. A knife-edge was applied (rate = 2.54 mm/min) at the bonding agent/amalgam interface of each sample until failure. Coefficients of determination for mean bond strength vs either roughness (R(a), of profile length were significantly higher for measurements in parallel directions than for those measurements in (+) directions. The shear bond strength to set amalgam for a PENTA-containing adhesives system (L.D. Caulk Division) was not significantly different from that of a PENTA-free adhesive (3M Dental Products Division), even though PENTA has been reported to increase bond strength to nonprecious metals. The shear bond strength of resin composite to amalgam is correlated to surface roughness when it is measured parallel to the polishing scratches. This correlation is significantly lower when surface roughness is measured in the typical manner, perpendicular to the polishing scratches.

Correlation of normal-range FMR1 repeat length or genotypes and reproductive parameters.

PubMed

Maslow, Bat-Sheva L; Davis, Stephanie; Engmann, Lawrence; Nulsen, John C; Benadiva, Claudio A

2016-09-01

This study aims to ascertain whether the length of normal-ranged CGG repeats on the FMR1 gene correlates with abnormal reproductive parameters. We performed a retrospective, cross-sectional study of all FMR1 carrier screening performed as part of routine care at a large university-based fertility center from January 2011 to March 2014. Correlations were performed between normal-range FMR1 length and baseline serum anti-Müllerian hormone (AMH), cycle day 3 follicle stimulating hormone (FSH), ovarian volumes (OV), antral follicle counts (AFC), and incidence of diminished ovarian reserve (DOR), while controlling for the effect of age. Six hundred three FMR1 screening results were collected. One subject was found to be a pre-mutation carrier and was excluded from the study. Baseline serum AMH, cycle day 3 FSH, OV, and AFC data were collected for the 602 subjects with normal-ranged CGG repeats. No significant difference in median age was noted amongst any of the FMR1 repeat genotypes. No significant correlation or association was found between any allele length or genotype, with any of the reproductive parameters or with incidence of DOR at any age (p > 0.05). However, subjects who were less than 35 years old with low/low genotype were significantly more likely to have below average AMH levels compared to those with normal/normal genotype (RR 3.82; 95 % CI 1.38-10.56). This large study did not demonstrate any substantial association between normal-range FMR1 repeat lengths and reproductive parameters.

Measurement of Trap Length for an Optical Trap

NASA Technical Reports Server (NTRS)

Wrbanek, Susan Y.

2009-01-01

The trap length along the beam axis for an optical trap formed with an upright, oil-immersion microscope was measured. The goals for this effort were twofold. It was deemed useful to understand the depth to which an optical trap can reach for purposes of developing a tool to assist in the fabrication of miniature devices. Additionally, it was desired to know whether the measured trap length favored one or the other of two competing theories to model an optical trap. The approach was to trap a microsphere of known size and mass and raise it from its initial trap position. The microsphere was then dropped by blocking the laser beam for a pre-determined amount of time. Dropping the microsphere in a free-fall mode from various heights relative to the coverslip provides an estimate of how the trapping length changes with depth in water in a sample chamber on a microscope slide. While it was not possible to measure the trap length with sufficient precision to support any particular theory of optical trap formation, it was possible to find regions where the presence of physical boundaries influenced optical traps, and determine that the trap length, for the apparatus studied, is between 6 and 7 m. These results allow more precise control using optical micromanipulation to assemble miniature devices by providing information about the distance over which an optical trap is effective.

Quantifying precision of in situ length and weight measurements of fish

USGS Publications Warehouse

Gutreuter, S.; Krzoska, D.J.

1994-01-01

We estimated and compared errors in field-made (in situ) measurements of lengths and weights of fish. We made three measurements of length and weight on each of 33 common carp Cyprinus carpio, and on each of a total of 34 bluegills Lepomis macrochirus and black crappies Pomoxis nigromaculatus. Maximum total lengths of all fish were measured to the nearest 1 mm on a conventional measuring board. The bluegills and black crappies (85–282 mm maximum total length) were weighed to the nearest 1 g on a 1,000-g spring-loaded scale. The common carp (415–600 mm maximum total length) were weighed to the nearest 0.05 kg on a 20-kg spring-loaded scale. We present a statistical model for comparison of coefficients of variation of length (Cl ) and weight (Cw ). Expected Cl was near zero and constant across mean length, indicating that length can be measured with good precision in the field. Expected Cw decreased with increasing mean length, and was larger than expected Cl by 5.8 to over 100 times for the bluegills and black crappies, and by 3 to over 20 times for the common carp. Unrecognized in situ weighing errors bias the apparent content of unique information in weight, which is the information not explained by either length or measurement error. We recommend procedures to circumvent effects of weighing errors, including elimination of unnecessary weighing from routine monitoring programs. In situ weighing must be conducted with greater care than is common if the content of unique and nontrivial information in weight is to be correctly identified.

Dynamic leg length asymmetry during gait is not a valid method for estimating mild anatomic leg length discrepancy.

PubMed

Leporace, Gustavo; Batista, Luiz Alberto; Serra Cruz, Raphael; Zeitoune, Gabriel; Cavalin, Gabriel Armondi; Metsavaht, Leonardo

2018-03-01

The purpose of this study was to test the validity of dynamic leg length discrepancy (DLLD) during gait as a radiation-free screening method for measuring anatomic leg length discrepancy (ALLD). Thirty-three subjects with mild leg length discrepancy walked along a walkway and the dynamic leg length discrepancy (DLLD) was calculated using a motion analysis system. Pearson correlation and paired Student t -tests were applied to calculate the correlation and compare the differences between DLLD and ALLD (α = 0.05). The results of our study showed DLLD is not a valid method to predict ALLD in subjects with mild limb discrepancy.

Novel measurements of the length of the subglottic airway in infants and young children.

PubMed

Sirisopana, Metee; Saint-Martin, Christine; Wang, Ning Nan; Manoukian, John; Nguyen, Lily H P; Brown, Karen A

2013-08-01

To date, the lengths of the subglottic and tracheal airway segments have been measured from autopsy specimens. Images of the head and neck obtained from computerized tomography (CT) provide an alternate method. Our objective in this study was to identify anatomic landmarks from CT scans in infants and young children to estimate the lengths of the subglottic and tracheal airway segments and to correlate these lengths with age. We performed a retrospective analysis of CT images of the neck for various diagnostic indications in children ≤3 years. We obtained planes of reconstruction at the level of the vocal cords (VCs), cricoid cartilage, and carina (C) which were parallel to each other and perpendicular to sagittal long axis of the trachea. The lengths of the subglottic airway (LengthSG) and total length of the laryngotracheal airway (LengthVC-C) were measured from the distance between, respectively, the VC versus cricoid cartilage and the VC versus C planes of reconstruction. Tracheal length was then calculated as the difference between LengthVC-C and LengthSG. Fifty-six children met the inclusion criteria. There were 29 boys. The median weight was 10.7 kg (range 3.1-19.0 kg). Regression analysis yielded mean LengthSG (mm) = 7.8 + 0.03·corrected age (months), r(2) = 0.07, P = 0.056; lower and upper 95% confidence interval for β = 0.03 were -0.001 and 0061. The mean LengthSG was 8.4 mm with an SD of 1.4 mm. The 95th percentile for LengthSG was 10.8 mm, and the 5% to 95% interquartile range was 4.9 mm. The estimate for the 95% confidence interval of the 95th percentile was between 10.2 and 11.3 mm. The LengthVC-C increased with age: mean LengthVC-C (cm) = 5.3 + 0.05·corrected age (months), r(2) = 0.7, P < 0.001. Tracheal length also increased with age: mean tracheal length (cm) = 4.5 + 0.05·corrected age (months), r(2) = 0.6, P < 0.001. We report a novel estimate method for the lengths of the airway segments between the VC and C in 56 infants and young children

Estimation of Kubo number and correlation length of fluctuating magnetic fields and pressure in BOUT + + edge pedestal collapse simulation

NASA Astrophysics Data System (ADS)

Kim, Jaewook; Lee, W.-J.; Jhang, Hogun; Kaang, H. H.; Ghim, Y.-C.

2017-10-01

Stochastic magnetic fields are thought to be as one of the possible mechanisms for anomalous transport of density, momentum and heat across the magnetic field lines. Kubo number and Chirikov parameter are quantifications of the stochasticity, and previous studies show that perpendicular transport strongly depends on the magnetic Kubo number (MKN). If MKN is smaller than one, diffusion process will follow Rechester-Rosenbluth model; whereas if it is larger than one, percolation theory dominates the diffusion process. Thus, estimation of Kubo number plays an important role to understand diffusion process caused by stochastic magnetic fields. However, spatially localized experimental measurement of fluctuating magnetic fields in a tokamak is difficult, and we attempt to estimate MKNs using BOUT + + simulation data with pedestal collapse. In addition, we calculate correlation length of fluctuating pressures and Chirikov parameters to investigate variation correlation lengths in the simulation. We, then, discuss how one may experimentally estimate MKNs.

Record length requirement of long-range dependent teletraffic

NASA Astrophysics Data System (ADS)

Li, Ming

2017-04-01

This article contributes the highlights mainly in two folds. On the one hand, it presents a formula to compute the upper bound of the variance of the correlation periodogram measurement of teletraffic (traffic for short) with long-range dependence (LRD) for a given record length T and a given value of the Hurst parameter H (Theorems 1 and 2). On the other hand, it proposes two formulas for the computation of the variance upper bound of the correlation periodogram measurement of traffic of fractional Gaussian noise (fGn) type and the generalized Cauchy (GC) type, respectively (Corollaries 1 and 2). They may constitute a reference guideline of record length requirement of traffic with LRD. In addition, record length requirement for the correlation periodogram measurement of traffic with either the Schuster type or the Bartlett one is studied and the present results about it show that both types of periodograms may be used for the correlation measurement of traffic with a pre-desired variance bound of correlation estimation. Moreover, real traffic in the Internet Archive by the Special Interest Group on Data Communication under the Association for Computing Machinery of US (ACM SIGCOMM) is analyzed in the case study in this topic.

[Shushu (ancient Chinese numerology) in Lingshu: Gudu (Miraculous Pivot: Bone-Length Measurement)].

PubMed

Zhuo, Lian-Shi

2010-10-01

Lingshu: Gudu (Miraculous Pivot: Bone-Length Measurement) is compared with literatures concerning the Shushu (ancient Chinese numerology) of the Qin Dynasty (221 B. C. - 206 B. C. ) and the Han Dynasty (206 B. C.-220 A. D.) in this article. And it is discovered that "the number of heaven and earth" in Yijing (The Book of Change) was implied in the bone-length measurement. The theory of Shushu is hidden in the sized of head, neck, chest, abdomen, back and 4 extremities according to the measurement. The meaning of establishment of bone-length measurement, which is found to have universality, laid in setting down the measurement of meridians. And it is the origin of the proportional measurement of locating acupoints. Checked with the theory of Shushu, errors in the description of bone-length measurement could also be found in Lingshu: Gudu (Miraculous Pivot: Bone-Length Measurement) of the present edition, which is helpful for the modern study on the measurement.

A comparison of correlation-length estimation methods for the objective analysis of surface pollutants at Environment and Climate Change Canada.

PubMed

Ménard, Richard; Deshaies-Jacques, Martin; Gasset, Nicolas

2016-09-01

An objective analysis is one of the main components of data assimilation. By combining observations with the output of a predictive model we combine the best features of each source of information: the complete spatial and temporal coverage provided by models, with a close representation of the truth provided by observations. The process of combining observations with a model output is called an analysis. To produce an analysis requires the knowledge of observation and model errors, as well as its spatial correlation. This paper is devoted to the development of methods of estimation of these error variances and the characteristic length-scale of the model error correlation for its operational use in the Canadian objective analysis system. We first argue in favor of using compact support correlation functions, and then introduce three estimation methods: the Hollingsworth-Lönnberg (HL) method in local and global form, the maximum likelihood method (ML), and the [Formula: see text] diagnostic method. We perform one-dimensional (1D) simulation studies where the error variance and true correlation length are known, and perform an estimation of both error variances and correlation length where both are non-uniform. We show that a local version of the HL method can capture accurately the error variances and correlation length at each observation site, provided that spatial variability is not too strong. However, the operational objective analysis requires only a single and globally valid correlation length. We examine whether any statistics of the local HL correlation lengths could be a useful estimate, or whether other global estimation methods such as by the global HL, ML, or [Formula: see text] should be used. We found in both 1D simulation and using real data that the ML method is able to capture physically significant aspects of the correlation length, while most other estimates give unphysical and larger length-scale values. This paper describes a proposed

Variability of interconnected wind plants: correlation length and its dependence on variability time scale

NASA Astrophysics Data System (ADS)

St. Martin, Clara M.; Lundquist, Julie K.; Handschy, Mark A.

2015-04-01

The variability in wind-generated electricity complicates the integration of this electricity into the electrical grid. This challenge steepens as the percentage of renewably-generated electricity on the grid grows, but variability can be reduced by exploiting geographic diversity: correlations between wind farms decrease as the separation between wind farms increases. But how far is far enough to reduce variability? Grid management requires balancing production on various timescales, and so consideration of correlations reflective of those timescales can guide the appropriate spatial scales of geographic diversity grid integration. To answer ‘how far is far enough,’ we investigate the universal behavior of geographic diversity by exploring wind-speed correlations using three extensive datasets spanning continents, durations and time resolution. First, one year of five-minute wind power generation data from 29 wind farms span 1270 km across Southeastern Australia (Australian Energy Market Operator). Second, 45 years of hourly 10 m wind-speeds from 117 stations span 5000 km across Canada (National Climate Data Archive of Environment Canada). Finally, four years of five-minute wind-speeds from 14 meteorological towers span 350 km of the Northwestern US (Bonneville Power Administration). After removing diurnal cycles and seasonal trends from all datasets, we investigate dependence of correlation length on time scale by digitally high-pass filtering the data on 0.25-2000 h timescales and calculating correlations between sites for each high-pass filter cut-off. Correlations fall to zero with increasing station separation distance, but the characteristic correlation length varies with the high-pass filter applied: the higher the cut-off frequency, the smaller the station separation required to achieve de-correlation. Remarkable similarities between these three datasets reveal behavior that, if universal, could be particularly useful for grid management. For high

Relationship between photoreceptor outer segment length and visual acuity in diabetic macular edema.

PubMed

Forooghian, Farzin; Stetson, Paul F; Meyer, Scott A; Chew, Emily Y; Wong, Wai T; Cukras, Catherine; Meyerle, Catherine B; Ferris, Frederick L

2010-01-01

The purpose of this study was to quantify photoreceptor outer segment (PROS) length in 27 consecutive patients (30 eyes) with diabetic macular edema using spectral domain optical coherence tomography and to describe the correlation between PROS length and visual acuity. Three spectral domain-optical coherence tomography scans were performed on all eyes during each session using Cirrus HD-OCT. A prototype algorithm was developed for quantitative assessment of PROS length. Retinal thicknesses and PROS lengths were calculated for 3 parameters: macular grid (6 x 6 mm), central subfield (1 mm), and center foveal point (0.33 mm). Intrasession repeatability was assessed using coefficient of variation and intraclass correlation coefficient. The association between retinal thickness and PROS length with visual acuity was assessed using linear regression and Pearson correlation analyses. The main outcome measures include intrasession repeatability of macular parameters and correlation of these parameters with visual acuity. Mean retinal thickness and PROS length were 298 mum to 381 microm and 30 microm to 32 mum, respectively, for macular parameters assessed in this study. Coefficient of variation values were 0.75% to 4.13% for retinal thickness and 1.97% to 14.01% for PROS length. Intraclass correlation coefficient values were 0.96 to 0.99 and 0.73 to 0.98 for retinal thickness and PROS length, respectively. Slopes from linear regression analyses assessing the association of retinal thickness and visual acuity were not significantly different from 0 (P > 0.20), whereas the slopes of PROS length and visual acuity were significantly different from 0 (P < 0.0005). Correlation coefficients for macular thickness and visual acuity ranged from 0.13 to 0.22, whereas coefficients for PROS length and visual acuity ranged from -0.61 to -0.81. Photoreceptor outer segment length can be quantitatively assessed using Cirrus HD-OCT. Although the intrasession repeatability of PROS

Young Children's Understandings of Length Measurement: Evaluating a Learning Trajectory

ERIC Educational Resources Information Center

Szilagyi, Janka; Clements, Douglas H.; Sarama, Julie

2013-01-01

This study investigated the development of length measurement ideas in students from prekindergarten through 2nd grade. The main purpose was to evaluate and elaborate the developmental progression, or levels of thinking, of a hypothesized learning trajectory for length measurement to ensure that the sequence of levels of thinking is consistent…

Two Point Space-Time Correlation of Density Fluctuations Measured in High Velocity Free Jets

NASA Technical Reports Server (NTRS)

Panda, Jayanta

2006-01-01

Two-point space-time correlations of air density fluctuations in unheated, fully-expanded free jets at Mach numbers M(sub j) = 0.95, 1.4, and 1.8 were measured using a Rayleigh scattering based diagnostic technique. The molecular scattered light from two small probe volumes of 1.03 mm length was measured for a completely non-intrusive means of determining the turbulent density fluctuations. The time series of density fluctuations were analyzed to estimate the integral length scale L in a moving frame of reference and the convective Mach number M(sub c) at different narrow Strouhal frequency (St) bands. It was observed that M(sub c) and the normalized moving frame length scale L*St/D, where D is the jet diameter, increased with Strouhal frequency before leveling off at the highest resolved frequency. Significant differences were observed between data obtained from the lip shear layer and the centerline of the jet. The wave number frequency transform of the correlation data demonstrated progressive increase in the radiative part of turbulence fluctuations with increasing jet Mach number.

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC..., App. C Appendix C to Part 622—Fish Length Measurements ER17AP13.000 ER17AP13.001 ...

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC..., App. C Appendix C to Part 622—Fish Length Measurements ER17AP13.000 ER17AP13.001 ...

Slip length measurement of gas flow.

PubMed

Maali, Abdelhamid; Colin, Stéphane; Bhushan, Bharat

2016-09-16

In this paper, we present a review of the most important techniques used to measure the slip length of gas flow on isothermal surfaces. First, we present the famous Millikan experiment and then the rotating cylinder and spinning rotor gauge methods. Then, we describe the gas flow rate experiment, which is the most widely used technique to probe a confined gas and measure the slip. Finally, we present a promising technique using an atomic force microscope introduced recently to study the behavior of nanoscale confined gas.

Measurement of Debye length in laser-produced plasma.

NASA Technical Reports Server (NTRS)

Ehler, W.

1973-01-01

The Debye length of an expanded plasma created by placing an evacuated chamber with an entrance slit in the path of a freely expanding laser produced plasma was measured, using the slab geometry. An independent measurement of electron density together with the observed value for the Debye length also provided a means for evaluating the plasma electron temperature. This temperature has applications in ascertaining plasma conductivity and magnetic field necessary for confinement of the laser produced plasma. Also, the temperature obtained would be useful in analyzing electron-ion recombination rates in the expanded plasma and the dynamics of the cooling process of the plasma expansion.

Predicted singers' vocal fold lengths and voice classification-a study of x-ray morphological measures.

PubMed

Roers, Friederike; Mürbe, Dirk; Sundberg, Johan

2009-07-01

Students admitted to the solo singing education at the University of Music Dresden, Germany have been submitted to a detailed physical examination of a variety of factors with relevance to voice function since 1959. In the years 1959-1991, this scheme of examinations included X-ray profiles of the singers' vocal tracts. This material of 132 X-rays of voice professionals was used to investigate different laryngeal morphological measures and their relation to vocal fold length. Further, the study aimed to investigate if there are consistent anatomical differences between singers of different voice classifications. The study design used was a retrospective analysis. Vocal fold length could be measured in 29 of these singer subjects directly. These data showed a strong correlation with the anterior-posterior diameter of the subglottis and the trachea as well as with the distance from the anterior contour of the thyroid cartilage to the anterior contour of the spine. These relations were used in an attempt to predict the 132 singers' vocal fold lengths. The results revealed a clear covariation between predicted vocal fold length and voice classification. Anterior-posterior subglottic-tracheal diameter yielded mean vocal fold lengths of 14.9, 16.0, 16.6, 18.4, 19.5, and 20.9mm for sopranos, mezzo-sopranos, altos, tenors, baritones, and basses, respectively. The data support the assumption that there are consistent anatomical laryngeal differences between singers of different voice classifications, which are of relevance to pitch range and timbre of the voice.

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix C to Part 622—Carapace...

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix C to Part 622—Carapace...

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix C to Part 622—Carapace...

Information content versus word length in random typing

NASA Astrophysics Data System (ADS)

Ferrer-i-Cancho, Ramon; Moscoso del Prado Martín, Fermín

2011-12-01

Recently, it has been claimed that a linear relationship between a measure of information content and word length is expected from word length optimization and it has been shown that this linearity is supported by a strong correlation between information content and word length in many languages (Piantadosi et al 2011 Proc. Nat. Acad. Sci. 108 3825). Here, we study in detail some connections between this measure and standard information theory. The relationship between the measure and word length is studied for the popular random typing process where a text is constructed by pressing keys at random from a keyboard containing letters and a space behaving as a word delimiter. Although this random process does not optimize word lengths according to information content, it exhibits a linear relationship between information content and word length. The exact slope and intercept are presented for three major variants of the random typing process. A strong correlation between information content and word length can simply arise from the units making a word (e.g., letters) and not necessarily from the interplay between a word and its context as proposed by Piantadosi and co-workers. In itself, the linear relation does not entail the results of any optimization process.

Boundary slip and wetting properties of interfaces: correlation of the contact angle with the slip length.

PubMed

Voronov, Roman S; Papavassiliou, Dimitrios V; Lee, Lloyd L

2006-05-28

Correlations between contact angle, a measure of the wetting of surfaces, and slip length are developed using nonequilibrium molecular dynamics for a Lennard-Jones fluid in Couette flow between graphitelike hexagonal-lattice walls. The fluid-wall interaction is varied by modulating the interfacial energy parameter epsilonr=epsilonsfepsilonff and the size parameter sigmar=sigmasfsigmaff, (s=solid, f=fluid) to achieve hydrophobicity (solvophobicity) or hydrophilicity (solvophilicity). The effects of surface chemistry, as well as the effects of temperature and shear rate on the slip length are determined. The contact angle increases from 25 degrees to 147 degrees on highly hydrophobic surfaces (as epsilonr decreases from 0.5 to 0.1), as expected. The slip length is functionally dependent on the affinity strength parameters epsilonr and sigmar: increasing logarithmically with decreasing surface energy epsilonr (i.e., more hydrophobic), while decreasing with power law with decreasing size sigmar. The mechanism for the latter is different from the energetic case. While weak wall forces (small epsilonr) produce hydrophobicity, larger sigmar smoothes out the surface roughness. Both tend to increase the slip. The slip length grows rapidly with a high shear rate, as wall velocity increases three decades from 100 to 10(5) ms. We demonstrate that fluid-solid interfaces with low epsilonr and high sigmar should be chosen to increase slip and are prime candidates for drag reduction.

Serum Concentration of Leptin in Pregnant Adolescents Correlated with Gestational Weight Gain, Postpartum Weight Retention and Newborn Weight/Length.

PubMed

Sámano, Reyna; Martínez-Rojano, Hugo; Chico-Barba, Gabriela; Godínez-Martínez, Estela; Sánchez-Jiménez, Bernarda; Montiel-Ojeda, Diana; Tolentino, Maricruz

2017-09-27

Introduction : Gestational weight gain is an important modifiable factor known to influence fetal outcomes including birth weight and adiposity. Leptin is normally correlated with adiposity and is also known to increase throughout pregnancy, as the placenta becomes a source of leptin synthesis. Several studies have reported positive correlations between cord blood leptin level and either birthweight or size for gestational age, as well as body mass index (BMI). Objective : To determine the correlation of prenatal leptin concentration in pregnant adolescents with their gestational weight gain, postpartum weight retention, and weight/length of their newborn. Methods : A cohort study was conducted on pregnant Mexican adolescents from Gestational Week 26-28 to three months postpartum ( n = 168 mother-child dyads). An anthropometric assessment was made of each pregnant adolescent, and the serum level of leptin and the intake of energy were determined. The newborn was evaluated each month during postpartum. Clinical records were reviewed to obtain sociodemographic data. Bivariate correlations, tests for repeating measurements and logistic regression models were performed. Results : Leptin concentration gradually increased during the third trimester of pregnancy. At Gestation Week 36, leptin level correlated with gestational weight gain. When comparing adolescents that had the lowest and highest concentration of leptin, the former presented a mean of 6 kg less in gestational weight gain (inter-subject leptin concentration, p = 0.001; inter-subject energy intake, p = 0.497). Leptin concentration and gestational weight gain exerted an effect on the weight of the newborn (inter-subject leptin concentration for Week 32, p = 0.024; inter-subject gestational weight gain, p = 0.011). Newborn length was associated with leptin concentration at Week 28 (leptin effect, p = 0.003; effect of gestational weight gain, p = 0.722). Conclusions : Pregnant adolescents with leptin

Serum Concentration of Leptin in Pregnant Adolescents Correlated with Gestational Weight Gain, Postpartum Weight Retention and Newborn Weight/Length

PubMed Central

Sámano, Reyna; Martínez-Rojano, Hugo; Godínez-Martínez, Estela; Sánchez-Jiménez, Bernarda; Montiel-Ojeda, Diana; Tolentino, Maricruz

2017-01-01

Introduction: Gestational weight gain is an important modifiable factor known to influence fetal outcomes including birth weight and adiposity. Leptin is normally correlated with adiposity and is also known to increase throughout pregnancy, as the placenta becomes a source of leptin synthesis. Several studies have reported positive correlations between cord blood leptin level and either birthweight or size for gestational age, as well as body mass index (BMI). Objective: To determine the correlation of prenatal leptin concentration in pregnant adolescents with their gestational weight gain, postpartum weight retention, and weight/length of their newborn. Methods: A cohort study was conducted on pregnant Mexican adolescents from Gestational Week 26–28 to three months postpartum (n = 168 mother–child dyads). An anthropometric assessment was made of each pregnant adolescent, and the serum level of leptin and the intake of energy were determined. The newborn was evaluated each month during postpartum. Clinical records were reviewed to obtain sociodemographic data. Bivariate correlations, tests for repeating measurements and logistic regression models were performed. Results: Leptin concentration gradually increased during the third trimester of pregnancy. At Gestation Week 36, leptin level correlated with gestational weight gain. When comparing adolescents that had the lowest and highest concentration of leptin, the former presented a mean of 6 kg less in gestational weight gain (inter-subject leptin concentration, p = 0.001; inter-subject energy intake, p = 0.497). Leptin concentration and gestational weight gain exerted an effect on the weight of the newborn (inter-subject leptin concentration for Week 32, p = 0.024; inter-subject gestational weight gain, p = 0.011). Newborn length was associated with leptin concentration at Week 28 (leptin effect, p = 0.003; effect of gestational weight gain, p = 0.722). Conclusions: Pregnant adolescents with leptin

A paired-laser photogrammetric method for in situ length measurement of benthic fishes

USGS Publications Warehouse

Rizzo, Austin A.; Welsh, Stuart A.; Thompson, Patricia A.

2017-01-01

Photogrammetry, a technique to obtain measurements from photographs, may be a valid method for measuring lengths of rare, threatened, or endangered species. Photogrammetric methods of measurement are nonintrusive and reduce the possibility of physical damage or physiological stress associated with the capture and handling of individuals. We evaluated precision and accuracy of photogrammetric length measurements relative to board measurements of Greenside Darters Etheostoma blennioides and Variegate Darters E. variatum in an aquarium and applied photogrammetry in a field study of the Diamond Darter Crystallaria cincotta, a federally listed endangered species. Digital photographs were taken of each individual using a waterproof camera equipped with two parallel lasers. Photogrammetric length measurements were digitized with ImageJ software. Agreement between board and photogrammetric measurements were high for Greenside and Variegate darters. The magnitude of differences was small between direct and photogrammetric measurements, ranging from 0.6% to 3.1%, depending on the species measured and the type of measurement taken. These results support photogrammetry as a useful method for obtaining length measurements of benthic stream fishes. Photogrammetric methods allowed for length measurements and an assessment of length frequency of 199 Diamond Darters, informative data for management that could not be collected with conventional measuring-board methods.

Slip length measurement of confined air flow on three smooth surfaces.

PubMed

Pan, Yunlu; Bhushan, Bharat; Maali, Abdelhamid

2013-04-02

An experimental measurement of the slip length of air flow close to three different solid surfaces is presented. The substrate was driven by a nanopositioner moving toward an oscillating glass sphere glued to an atomic force microscopy (AFM) cantilever. A large separation distance was used to get more effective data. The slip length value was obtained by analyzing the amplitude and phase data of the cantilever. The measurements show that the slip length does not depend on the oscillation amplitude of the cantilever. Because of the small difference among the slip lengths of the three surfaces, a simplified analysis method was used. The results show that on glass, graphite, and mica surfaces the slip lengths are 98, 234, and 110 nm, respectively.

Implementation of a flow-dependent background error correlation length scale formulation in the NEMOVAR OSTIA system

NASA Astrophysics Data System (ADS)

Fiedler, Emma; Mao, Chongyuan; Good, Simon; Waters, Jennifer; Martin, Matthew

2017-04-01

OSTIA is the Met Office's Operational Sea Surface Temperature (SST) and Ice Analysis system, which produces L4 (globally complete, gridded) analyses on a daily basis. Work is currently being undertaken to replace the original OI (Optimal Interpolation) data assimilation scheme with NEMOVAR, a 3D-Var data assimilation method developed for use with the NEMO ocean model. A dual background error correlation length scale formulation is used for SST in OSTIA, as implemented in NEMOVAR. Short and long length scales are combined according to the ratio of the decomposition of the background error variances into short and long spatial correlations. The pre-defined background error variances vary spatially and seasonally, but not on shorter time-scales. If the derived length scales applied to the daily analysis are too long, SST features may be smoothed out. Therefore a flow-dependent component to determining the effective length scale has also been developed. The total horizontal gradient of the background SST field is used to identify regions where the length scale should be shortened. These methods together have led to an improvement in the resolution of SST features compared to the previous OI analysis system, without the introduction of spurious noise. This presentation will show validation results for feature resolution in OSTIA using the OI scheme, the dual length scale NEMOVAR scheme, and the flow-dependent implementation.

Measuring g with a classroom pendulum using changes in the pendulum string length

NASA Astrophysics Data System (ADS)

Oliveira, V.

2016-11-01

This frontline presents a simple apparatus for measuring the acceleration of gravity using a classroom pendulum. Instead of the traditional method where the pendulum period is measured as a function of its length, here the period is measured as a function of changes in the pendulum string length. The major advantage of this method is that students can measure these changes with a greater accuracy than measuring the total pendulum length.

Recovering refractive index correlation function from measurement of tissue scattering phase function (Conference Presentation)

NASA Astrophysics Data System (ADS)

Rogers, Jeremy D.

2016-03-01

Numerous methods have been developed to quantify the light scattering properties of tissue. These properties are of interest in diagnostic and screening applications due to sensitivity to changes in tissue ultrastructure and changes associated with disease such as cancer. Tissue is considered a weak scatterer because that the mean free path is much larger than the correlation length. When this is the case, all scattering properties can be calculated from the refractive index correlation function Bn(r). Direct measurement of Bn(r) is challenging because it requires refractive index measurement at high resolution over a large tissue volume. Instead, a model is usually assumed. One particularly useful model, the Whittle-Matern function includes several realistic function types such as mass fractal and exponential. Optical scattering properties for weakly scattering media can be determined analytically from Bn(r) by applying the Rayleigh-Gans-Debye (RGD) or Born Approximation, and so measured scattering properties are used to fit parameters of the model function. Direct measurement of Bn(r) would provide confirmation that the function is a good representation of tissue or help in identifying the length scale at which changes occur. The RGD approximation relates the scattering phase function to the refractive index correlation function through a Fourier transform. This can be inverted without approximation, so goniometric measurement of the scattering can be converted to Bn(r). However, geometric constraints of the measurement of the phase function, angular resolution, and wavelength result in a band limited measurement of Bn(r). These limits are discussed and example measurements are described.

Bond Length Equalization with molecular aromaticity-A new measurement of aromaticity.

PubMed

Shen, Chen-Fei; Liu, Zi-Zhong; Liu, Hong-Xia; Zhang, Hui-Qing

2018-05-08

A new method to measure the amount of aromaticity is presented through the process of Bond Length Equalization (BLE). Degree of Aromaticity (DOA), a two-dimensional intensive quantity including geometric and energetic factors, as a new measurement of aromaticity is proposed. The unique characteristic of DOA and the formation of DOA will be displayed. The calculation of the geometrical optimization, DOA, Nucleus Independent Chemical Shifts (NICS) and Ring Stretching Vibration Raman Spectroscopy Frequency (RSVRSF) for the aromatic ring molecules - G n H n m (G = C, Si, Ge, n = 3, 5-8, m = +1, -1, 0, +1, +2) were calculated using the method of Density Functional Theory (DFT). The correlation between radius angle and molecular energy is absolute quadratic in the process of BLE. As the increasing of the number of ring atoms, the value of DOA decreasing gradually, the aromaticity decreased gradually, which was a same conclusion as NICS and RSVRSF concluded. Copyright © 2018 Elsevier B.V. All rights reserved.

Finger length ratio (2D:4D) correlates with physical aggression in men but not in women.

PubMed

Bailey, Allison A; Hurd, Peter L

2005-03-01

Finger length ratio (2D:4D) is a sexually dimorphic trait. Men have relatively shorter second digits (index fingers) than fourth digits (ring fingers). Smaller, more masculine, digit ratios are thought to be associated with either higher prenatal testosterone levels or greater sensitivity to androgens, or both. Men with more masculine finger ratios are perceived as being more masculine and dominant by female observers, and tend to perform better in a number of physical sports. We hypothesized that digit ratio would correlate with propensity to engage in aggressive behavior. We examined the relationship between trait aggression, assayed using a questionnaire, and finger length ratio in both men and women. Men with lower, more masculine, finger length ratios had higher trait physical aggression scores (r(partial) = -0.21, N = 134, P = 0.028). We found no correlation between finger length ratio and any form of aggression in females. These results are consistent with the hypothesis that testosterone has an organizational effect on adult physical aggression in men.

A comparison of two methods for measuring vessel length in woody plants.

PubMed

Pan, Ruihua; Geng, Jing; Cai, Jing; Tyree, Melvin T

2015-12-01

Vessel lengths are important to plant hydraulic studies, but are not often reported because of the time required to obtain measurements. This paper compares the fast dynamic method (air injection method) with the slower but traditional static method (rubber injection method). Our hypothesis was that the dynamic method should yield a larger mean vessel length than the static method. Vessel length was measured by both methods in current year stems of Acer, Populus, Vitis and Quercus representing short- to long-vessel species. The hypothesis was verified. The reason for the consistently larger values of vessel length is because the dynamic method measures air flow rates in cut open vessels. The Hagen-Poiseuille law predicts that the air flow rate should depend on the product of number of cut open vessels times the fourth power of vessel diameter. An argument is advanced that the dynamic method is more appropriate because it measures the length of the vessels that contribute most to hydraulic flow. If all vessels had the same vessel length distribution regardless of diameter, then both methods should yield the same average length. This supports the hypothesis that large-diameter vessels might be longer than short-diameter vessels in most species. © 2015 John Wiley & Sons Ltd.

Vibration transfer mobility measurements using maximum length sequences

NASA Astrophysics Data System (ADS)

Singleton, Herbert L.

2005-09-01

Vibration transfer mobility measurements are required under Federal Transit Administration guidelines when developing detailed predictions of ground-borne vibration for rail transit systems. These measurements typically use a large instrumented hammer to generate impulses in the soil. These impulses are measured by an array of accelerometers to characterize the transfer mobility of the ground in a localized area. While effective, these measurements often make use of heavy, custom-engineered equipment to produce the impulse signal. To obtain satisfactory signal-to-noise ratios, it is necessary to generate multiple impulses to generate an average value, but this process involves considerable physical labor in the field. To address these shortcomings, a transfer mobility measurement system utilizing a tactile transducer and maximum length sequences (MLS) was developed. This system uses lightweight off-the-shelf components to significantly reduce the weight and cost of the system. The use of MLS allows for adequate signal-to-noise ratio from the tactile transducer, while minimizing the length of the measurement. Tests of the MLS system show good agreement with the impulse-based method. The combination of the cost savings and reduced weight of this new system facilitates transfer mobility measurements that are less physically demanding, and more economical when compared with current methods.

ATLAS-3 correlative measurement opportunities with UARS and surface observations

NASA Technical Reports Server (NTRS)

Harrison, Edwin F.; Denn, Fred M.; Gibson, Gary G.

1995-01-01

The third ATmospheric Laboratory for Applications and Science (ATLAS-3) mission was flown aboard the Space Shuttle launched on November 3, 1994. The mission length was approximately 10 days and 22 hours. The ATLAS-3 Earth-viewing instruments provided a large number of measurements which were nearly coincident with observations from experiments on the Upper Atmosphere Research Satellite (UARS). Based on ATLAS-3 instrument operating schedules, simulations were performed to determine when and where correlative measurements occurred between ATLAS and UARS instruments, and between ATLAS and surface observations. Results of these orbital and instrument simulations provide valuable information for scientists to compare measurements between various instruments on the two satellites and at selected surface sites.

The impact of precise robotic lesion length measurement on stent length selection: ramifications for stent savings.

PubMed

Campbell, Paul T; Kruse, Kevin R; Kroll, Christopher R; Patterson, Janet Y; Esposito, Michele J

2015-09-01

Coronary stent deployment outcomes can be negatively impacted by inaccurate lesion measurement and inappropriate stent length selection (SLS). We compared visual estimate of these parameters to those provided by the CorPath 200® Robotic PCI System. Sixty consecutive patients who underwent coronary stent placement utilizing the CorPath System were evaluated. The treating physician assessed orthogonal images and provided visual estimates of lesion length and SLS. The robotic system was then used for the same measures. SLS was considered to be accurate when visual estimate and robotic measures were in agreement. Visual estimate SLSs were considered to be "short" or "long" if they were below or above the robotic-selected stents, respectively. Only 35% (21/60) of visually estimated lesions resulted in accurate SLS, whereas 33% (20/60) and 32% (19/60) of the visually estimated SLSs were long and short, respectively. In 5 cases (8.3%), 1 less stent was placed based on the robotic lesion measurement being shorter than the visual estimate. Visual estimate assessment of lesion length and SLS is highly variable with 65% of the cases being inaccurately measured when compared to objective measures obtained from the robotic system. The 32% of the cases where lesions were visually estimated to be short represents cases that often require the use of extra stents after the full lesion is not covered by 1 stent [longitudinal geographic miss (LGM)]. Further, these data showed that the use of the robotic system prevented the use of extra stents in 8.3% of the cases. Measurement of lesions with robotic PCI may reduce measurement errors, need for extra stents, and LGM. Copyright © 2015 Elsevier Inc. All rights reserved.

Length-free near infrared measurement of newborn malnutrition

NASA Astrophysics Data System (ADS)

Mustafa, Fatin Hamimi; Bek, Emily J.; Huvanandana, Jacqueline; Jones, Peter W.; Carberry, Angela E.; Jeffery, Heather E.; Jin, Craig T.; McEwan, Alistair L.

2016-11-01

Under-nutrition in neonates can cause immediate mortality, impaired cognitive development and early onset adult disease. Body fat percentage measured using air-displacement-plethysmography has been found to better indicate under-nutrition than conventional birth weight percentiles. However, air-displacement-plethysmography equipment is expensive and non-portable, so is not suited for use in developing communities where the burden is often the greatest. We proposed a new body fat measurement technique using a length-free model with near-infrared spectroscopy measurements on a single site of the body - the thigh. To remove the need for length measurement, we developed a model with five discrete wavelengths and a sex parameter. The model was developed using air-displacement-plethysmography measurements in 52 neonates within 48 hours of birth. We identified instrumentation required in a low-cost LED-based screening device and incorporated a receptor device that can increase the amount of light collected. This near-infrared method may be suitable as a low cost screening tool for detecting body fat levels and monitoring nutritional interventions for malnutrition in neonates and young children in resource-constrained communities.

On the saturation of the refractive index structure function. II - Influence of the correlation length on astronomical 'seeing'

NASA Technical Reports Server (NTRS)

Venkatakrishnan, P.

1987-01-01

A physical length scale in the wavefront corresponding to the parameter (r sub 0) characterizing the loss in detail in a long exposure image is identified, and the influence of the correlation scale of turbulence as r sub 0 approaches this scale is shown. Allowing for the effect of 2-point correlations in the fluctuations of the refractive index, Venkatakrishnan and Chatterjee (1987) proposed a modified law for the phase structure function. It is suggested that the departure of the phase structure function from the 5/3 power law for length scales in the wavefront approaching the correlation scale of turbulence may lead to better 'seeing' at longer wavelengths.

An Imaging System for Automated Characteristic Length Measurement of Debrisat Fragments

NASA Technical Reports Server (NTRS)

Moraguez, Mathew; Patankar, Kunal; Fitz-Coy, Norman; Liou, J.-C.; Sorge, Marlon; Cowardin, Heather; Opiela, John; Krisko, Paula H.

2015-01-01

The debris fragments generated by DebriSat's hypervelocity impact test are currently being processed and characterized through an effort of NASA and USAF. The debris characteristics will be used to update satellite breakup models. In particular, the physical dimensions of the debris fragments must be measured to provide characteristic lengths for use in these models. Calipers and commercial 3D scanners were considered as measurement options, but an automated imaging system was ultimately developed to measure debris fragments. By automating the entire process, the measurement results are made repeatable and the human factor associated with calipers and 3D scanning is eliminated. Unlike using calipers to measure, the imaging system obtains non-contact measurements to avoid damaging delicate fragments. Furthermore, this fully automated measurement system minimizes fragment handling, which reduces the potential for fragment damage during the characterization process. In addition, the imaging system reduces the time required to determine the characteristic length of the debris fragment. In this way, the imaging system can measure the tens of thousands of DebriSat fragments at a rate of about six minutes per fragment, compared to hours per fragment in NASA's current 3D scanning measurement approach. The imaging system utilizes a space carving algorithm to generate a 3D point cloud of the article being measured and a custom developed algorithm then extracts the characteristic length from the point cloud. This paper describes the measurement process, results, challenges, and future work of the imaging system used for automated characteristic length measurement of DebriSat fragments.

Leukocyte Telomere Length in Major Depression: Correlations with Chronicity, Inflammation and Oxidative Stress - Preliminary Findings

PubMed Central

Wolkowitz, Owen M.; Mellon, Synthia H.; Epel, Elissa S.; Lin, Jue; Dhabhar, Firdaus S.; Su, Yali; Reus, Victor I.; Rosser, Rebecca; Burke, Heather M.; Kupferman, Eve; Compagnone, Mariana; Nelson, J. Craig; Blackburn, Elizabeth H.

2011-01-01

Background Depression is associated with an unusually high rate of aging-related illnesses and early mortality. One aspect of “accelerated aging” in depression may be shortened leukocyte telomeres. When telomeres critically shorten, as often occurs with repeated mitoses or in response to oxidation and inflammation, cells may die. Indeed, leukocyte telomere shortening predicts early mortality and medical illnesses in non-depressed populations. We sought to determine if leukocyte telomeres are shortened in Major Depressive Disorder (MDD), whether this is a function of lifetime depression exposure and whether this is related to putative mediators, oxidation and inflammation. Methodology Leukocyte telomere length was compared between 18 unmedicated MDD subjects and 17 controls and was correlated with lifetime depression chronicity and peripheral markers of oxidation (F2-isoprostane/Vitamin C ratio) and inflammation (IL-6). Analyses were controlled for age and sex. Principal Findings The depressed group, as a whole, did not differ from the controls in telomere length. However, telomere length was significantly inversely correlated with lifetime depression exposure, even after controlling for age (p<0.05). Average telomere length in the depressed subjects who were above the median of lifetime depression exposure (≥9.2 years' cumulative duration) was 281 base pairs shorter than that in controls (p<0.05), corresponding to approximately seven years of “accelerated cell aging.” Telomere length was inversely correlated with oxidative stress in the depressed subjects (p<0.01) and in the controls (p<0.05) and with inflammation in the depressed subjects (p<0.05). Conclusions These preliminary data indicate that accelerated aging at the level of leukocyte telomeres is proportional to lifetime exposure to MDD. This might be related to cumulative exposure to oxidative stress and inflammation in MDD. This suggest that telomere shortening does not antedate depression and is

Automatic interface measurement and analysis. [shoreline length of Alabama using LANDSAT imagery

NASA Technical Reports Server (NTRS)

Faller, K. H.

1975-01-01

A technique for detecting and measuring the interface between two categories in classified scanner data is described together with two application demonstrations. Measurements were found to be accurate to 1.5% root mean square error on features of known length while comparison of measurements made using the technique on LANDSAT data to opisometer measurements on 1:24,000 scale maps shows excellent agreement. Application of the technique to two frames of LANDSAT data classified using a two channel, two class classifier resulted in a computation of 64 km annual decrease in shoreline length. The tidal shoreline of a portion of Alabama was measured using LANDSAT data. Based on the measurement of this portion, the total tidal shoreline length of Alabama is estimated to be 1313 kilometers.

Diffusion length measurements using the scanning electron microscope. [in semiconductor devices

NASA Technical Reports Server (NTRS)

Weizer, V. G.

1975-01-01

A measurement technique employing the scanning electron microscope is described in which values of the true bulk diffusion length are obtained. It is shown that surface recombination effects can be eliminated through the application of highly doped surface field layers. The influence of high injection level effects and low-high junction current generation on the resulting measurement was investigated. Close agreement is found between the diffusion lengths measured by this method and those obtained using a penetrating radiation technique.

Importance of cervical length in dysmenorrhoea aetiology.

PubMed

Zebitay, Ali G; Verit, Fatma F; Sakar, M Nafi; Keskin, Seda; Cetin, Orkun; Ulusoy, A Ibrahim

2016-05-01

The objective of this prospective case-control study was to determine whether uterine corpus and cervical length measurements have a role in dysmenorrhoea aetiology in virgins. Patients with severe primary dysmenorrhoea with visual analog scale scores of ≥7 composed the dysmenorrhoea group (n = 51), while the control group (n = 51) was of women with painless menstrual cycles or with mild pain. Longitudinal and transverse axes of the uterine cervix and uterine corpus were measured. Correlation between severity of dysmenorrhoea and uterine cervix and corpus axes was calculated. Longitudinal and transverse axes of uterine cervix as well as uterine cervix volume were significantly higher in the dysmenorrhoea group compared to the controls. There was a significant positive correlation between severity of dysmenorrhoea and the length of cervical longitudinal and transverse axes and uterine cervical volume. Our findings reveal longer cervical length and greater cervical volume in young virgin patients with dysmenorrhoea and severe pain compared to those with no or less pain.

Measurement of cochlear length using the 'A' value for cochlea basal diameter: A feasibility study.

PubMed

Deep, Nicholas L; Howard, Brittany E; Holbert, Sarah O; Hoxworth, Joseph M; Barrs, David M

2017-07-01

To determine whether the cochlea basal diameter (A value) measurement can be consistently and precisely obtained from high-resolution temporal bone imaging for use in cochlear length estimation. A feasibility study at a tertiary referral center was performed using the temporal bone CTs of 40 consecutive patients. The distance from the round window to the lateral wall was measured for each cochlea by two independent reviewers, a neuroradiologist and an otolaryngologist. The interrater reliability was calculated using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. Forty patients (19 males, 21 females) for a total of 80 cochleae were included. Interrater reliability on the same ear had a high level of agreement by both the ICC and the Bland-Altman plot. ICCs were 0.90 (95% CI: 0.82, 0.94) for the left ear and 0.96 (95% CI: 0.92, 0.98) for the right ear. Bland-Altman plot confirmed interrater reliability with all 96% of measurements falling within the 95% limits of agreement. Measurement between the round window and lateral cochlear wall can be consistently and reliably obtained from high-resolution temporal bone CT scans. Thus, it is feasible to utilize this method to estimate the cochlear length of patients undergoing cochlear implantation.

Observers' measurements in premetric electrodynamics: Time and radar length

NASA Astrophysics Data System (ADS)

Gürlebeck, Norman; Pfeifer, Christian

2018-04-01

The description of an observer's measurement in general relativity and the standard model of particle physics is closely related to the spacetime metric. In order to understand and interpret measurements, which test the metric structure of the spacetime, like the classical Michelson-Morley, Ives-Stilwell, Kennedy-Thorndike experiments or frequency comparison experiments in general, it is necessary to describe them in theories, which go beyond the Lorentzian metric structure. However, this requires a description of an observer's measurement without relying on a metric. We provide such a description of an observer's measurement of the fundamental quantities time and length derived from a premetric perturbation of Maxwell's electrodynamics and a discussion on how these measurements influence classical relativistic observables like time dilation and length contraction. Most importantly, we find that the modification of electrodynamics influences the measurements at two instances: the propagation of light is altered as well as the observer's proper time normalization. When interpreting the results of a specific experiment, both effects cannot be disentangled, in general, and have to be taken into account.

Which Anthropometric Measure Best Correlates with Neonatal Fat Mass at Birth?

PubMed

Dubnov-Raz, Gal; Gal, Moran; Landau-Helman, Yeela; Biderman, Lihi; Nir, Romy; Maayan-Metzger, Ayala

2016-07-01

Objective Body composition provides additional information than weight alone. There is currently no accepted anthropometric measure of adiposity in infants, yet weight and length data allow calculations of a wide array of indices. The study objective was to identify the anthropometric index which best correlates with neonatal adiposity, by examining the associations between neonatal fat mass and several anthropometric indices of newborn infants. Study Design The sum of skinfolds (SSF), birth weight, and birth length were measured in 94 healthy infants (58% males) born at term to healthy mothers. Several anthropometric indices were calculated, and their relationship with SSF was assessed using linear regression adjusting for gestational age and sex. Results SSF at birth was significantly higher in females compared with males (20.7 ± 3.3 vs. 18.8 ± 4.1 mm, p = 0.019). Birth weight, birth weight-for-gestational-age percentile, birth weight percentile, and weight/length ratio had the highest associations with SSF, yet R (2) values were very low, ranging from 16 to 18%. Body mass index (BMI), BMI percentile, ponderal index, and the symmetry index had even lower associations. Conclusion No anthropometric measure can confidently assess fat mass in infants at birth, in accordance with previous research. When body composition data are needed, they should be directly measured. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Estimation of axial curvature of anterior sclera: correlation between axial length and anterior scleral curvature as affected by angle kappa.

PubMed

Lee, Sang-Mok; Choi, Hyuk Jin; Choi, Heejin; Kim, Mee Kum; Wee, Won Ryang

2016-10-07

BACKGROUND: Though the development and fitting of scleral contact lenses are expanding steadily, there is no simple method to provide scleral metrics for scleral contact lens fitting yet. The aim of this study was to establish formulae for estimation of the axial radius of curvature (ARC) of the anterior sclera using ocular biometric parameters that can be easily obtained with conventional devices. A semi-automated stitching method and a computational analysis tool for calculating ARC were developed by using the ImageJ and MATLAB software. The ARC of all the ocular surface points were analyzed from the composite horizontal cross-sectional images of the right eyes of 24 volunteers; these measurements were obtained using anterior segment optical coherence tomography for a previous study (AS-OCT; Visante). Ocular biometric parameters were obtained from the same volunteers with slit-scanning topography and partial coherence interferometry. Correlation analysis was performed between the ARC at 8 mm to the axis line (ARC[8]) and other ocular parameters (including age). With ARC obtained on several nasal and temporal points (7.0, 7.5, 8.0, 8.5, and 9.0 mm from the axis line), univariate and multivariate linear regression analyses were performed to develop a model for estimating ARC with the help of ocular biometric parameters. Axial length, spherical equivalent, and angle kappa showed correlations with temporal ARC[8] (tARC[8]; Pearson's r = 0.653, -0.579, and -0.341; P = 0.001, 0.015, and 0.015, respectively). White-to-white corneal diameter (WTW) and anterior chamber depth (ACD) showed correlation with nasal ARC[8] (nARC[8]; Pearson's r = -0.492 and -0.461; P = 0.015 and 0.023, respectively). The formulae for estimating scleral curvatures (tARC, nARC, and average ARC) were developed as a function of axial length, ACD, WTW, and distance from the axis line, with good determinant power (72 - 80 %; SPSS ver. 22.0). Angle kappa showed strong

Complex transition metal hydrides: linear correlation of countercation electronegativity versus T-D bond lengths.

PubMed

Humphries, T D; Sheppard, D A; Buckley, C E

2015-06-30

For homoleptic 18-electron complex hydrides, an inverse linear correlation has been established between the T-deuterium bond length (T = Fe, Co, Ni) and the average electronegativity of the metal countercations. This relationship can be further employed towards aiding structural solutions and predicting physical properties of novel complex transition metal hydrides.

Correlation of HAMP gene polymorphisms and expression with the susceptibility and length of hospital stays in Taiwanese children with Kawasaki disease

PubMed Central

Lu, Hsing-Fang; Wong, Henry Sung-Ching; Yu, Hong-Ren; Kuo, Hsing-Chun; Huang, Fu-Chen; Lo, Mao-Hung; Hsieh, Kai-Sheng; Chen, Su-Fen; Chang, Wei-Chiao; Kuo, Ho-Chang

2017-01-01

Kawasaki disease (KD) is a form of systemic vasculitis. Regarding its pathogenesis, HAMP gene encoding hepcidin, which is significant for iron metabolism, has a vital function. In this study, we recruited a total of 381 KD patients for genotyping. Data from 997 subjects (500 subjects from cohort 1; 497 subjects from cohort 2) were used for analysis. Using TaqMan allelic discrimination, we determined five tag SNPs (rs916145, rs10421768, rs3817623, rs7251432, and rs2293689). Treatment outcome data related to such clinical phenotypes as coronary artery lesions (CAL), coronary artery aneurysms (CAA), and intravenous immunoglobulin (IVIG) effects were also collected. Furthermore, we measured plasma hepcidin levels with an enzyme-linked immunosorbent assay. We found that HAMP gene polymorphism (rs7251432, and rs2293689) was significantly correlated with KD risk and that plasma hepcidin levels both before and after IVIG treatment had a significantly positive correlation with length of hospital stays (R = 0.217, p = 0.046 and R = 0.381, p < 0.0001, respectively). In contrast, plasma hepcidin levels has a negative correlation with KD patients’ albumin levels (R = −0.27, p < 0.001) prior to IVIG treatment. This study's findings indicate that HAMP might have a role in the disease susceptibility, as well as its expressions correlated length of hospital stays, and albumin levels in Taiwanese children with KD. PMID:28881695

An automated A-value measurement tool for accurate cochlear duct length estimation.

PubMed

Iyaniwura, John E; Elfarnawany, Mai; Ladak, Hanif M; Agrawal, Sumit K

2018-01-22

There has been renewed interest in the cochlear duct length (CDL) for preoperative cochlear implant electrode selection and postoperative generation of patient-specific frequency maps. The CDL can be estimated by measuring the A-value, which is defined as the length between the round window and the furthest point on the basal turn. Unfortunately, there is significant intra- and inter-observer variability when these measurements are made clinically. The objective of this study was to develop an automated A-value measurement algorithm to improve accuracy and eliminate observer variability. Clinical and micro-CT images of 20 cadaveric cochleae specimens were acquired. The micro-CT of one sample was chosen as the atlas, and A-value fiducials were placed onto that image. Image registration (rigid affine and non-rigid B-spline) was applied between the atlas and the 19 remaining clinical CT images. The registration transform was applied to the A-value fiducials, and the A-value was then automatically calculated for each specimen. High resolution micro-CT images of the same 19 specimens were used to measure the gold standard A-values for comparison against the manual and automated methods. The registration algorithm had excellent qualitative overlap between the atlas and target images. The automated method eliminated the observer variability and the systematic underestimation by experts. Manual measurement of the A-value on clinical CT had a mean error of 9.5 ± 4.3% compared to micro-CT, and this improved to an error of 2.7 ± 2.1% using the automated algorithm. Both the automated and manual methods correlated significantly with the gold standard micro-CT A-values (r = 0.70, p < 0.01 and r = 0.69, p < 0.01, respectively). An automated A-value measurement tool using atlas-based registration methods was successfully developed and validated. The automated method eliminated the observer variability and improved accuracy as compared to manual

Relationship between hamstring length and gluteus maximus strength with and without normalization.

PubMed

Lee, Dong-Kyu; Oh, Jae-Seop

2018-01-01

[Purpose] This study assessed the relationship between hamstring length and gluteus maximus (GM) strength with and without normalization by body weight and height. [Subjects and Methods] In total, 34 healthy male subjects volunteered for this study. To measure GM strength, subjects performed maximal hip joint extension with the knee joints flexed to 90° in the prone position. GM strength was normalized for body weight and height. [Results] GM strength with normalization was positively correlated with hamstring length, whereas GM strength without normalization was negatively correlated with hamstring length. [Conclusion] The normalization of GM strength by body weight and height has the potential to lead to more appropriate conclusions and interpretations about its correlation with hamstring length. Hamstring length may be related to GM strength.

Sociodemographic correlates and family aggregation of leukocyte telomere length in adults and children from Mesoamerica.

PubMed

Flannagan, Kerry S; Jansen, Erica C; Rozek, Laura S; Rentschler, Katie M; Roman, Ana Victoria; Ramirez-Zea, Manuel; Villamor, Eduardo

2017-05-06

Telomere length is a biomarker of cumulative stress and inflammation related to chronic disease risk. We examined the associations of leukocyte telomere length (LTL) with sociodemographic and anthropometric variables and estimated LTL family aggregation in Central America, a region with a high burden of chronic disease where LTL has not been studied. We conducted a cross-sectional study of 174 school age children and their parents in the capital cities of Belize, Honduras, Nicaragua, Costa Rica, Panama, and the city of Tuxtla-Gutierrez in Mexico. We measured LTL by quantitative PCR in DNA extracted from whole blood. We compared the distribution of LTL by categories of sociodemographic and anthropometric characteristics using linear regression. Family aggregation was estimated with correlation coefficients and intraclass correlations. In mothers, LTL was inversely associated with age (P, trend < .0001) and positively associated with height (P = .0002). Among fathers, LTL was inversely associated with food insecurity (P, trend = .0004). In children, boys had 0.10 log units shorter LTL than girls (95% CI: -0.17, -0.03; P = .004). LTL was inversely associated with parental education (P, trend = .01) and positively associated with paternal age at birth (P, trend < .0001), maternal LTL (P, trend = .007), and paternal LTL (P, trend = .02). LTL varied significantly by country of origin among all family members. Aggregation was greatest between children and their mothers, and mostly occurred at the country, rather than family, level. LTL is associated with age and height in women; food insecurity in men; and sex, parental education, parental LTL, and paternal age at birth among children. © 2016 Wiley Periodicals, Inc.

Gestational length assignment based on last menstrual period, first trimester crown-rump length, ovulation, and implantation timing.

PubMed

Mahendru, Amita A; Wilhelm-Benartzi, Charlotte S; Wilkinson, Ian B; McEniery, Carmel M; Johnson, Sarah; Lees, Christoph

2016-10-01

Understanding the natural length of human pregnancy is central to clinical care. However, variability in the reference methods to assign gestational age (GA) confound our understanding of pregnancy length. Assignation from ultrasound measurement of fetal crown-rump length (CRL) has superseded that based on last menstrual period (LMP). Our aim was to estimate gestational length based on LMP, ultrasound CRL, and implantation that were known, compared to pregnancy duration assigned by day of ovulation. Prospective study in 143 women trying to conceive. In 71 ongoing pregnancies, gestational length was estimated from LMP, CRL at 10-14 weeks, ovulation, and implantation day. For each method of GA assignment, the distribution in observed gestational length was derived and both agreement and correlation between the methods determined. Median ovulation and implantation days were 16 and 27, respectively. The gestational length based on LMP, CRL, implantation, and ovulation was similar: 279, 278, 276.5 and 276.5 days, respectively. The distributions for observed gestational length were widest where GA was assigned from CRL and LMP and narrowest when assigned from implantation and ovulation day. The strongest correlation for gestational length assessment was between ovulation and implantation (r = 0.98) and weakest between CRL and LMP (r = 0.88). The most accurate method of predicting gestational length is ovulation day, and this agrees closely with implantation day. Prediction of gestational length from CRL and known LMP are both inferior to ovulation and implantation day. This information could have important implications on the routine assignment of gestational age.

Variability of interconnected wind plants: correlation length and its dependence on variability time scale

DOE PAGES

St. Martin, Clara M.; Lundquist, Julie K.; Handschy, Mark A.

2015-04-02

The variability in wind-generated electricity complicates the integration of this electricity into the electrical grid. This challenge steepens as the percentage of renewably-generated electricity on the grid grows, but variability can be reduced by exploiting geographic diversity: correlations between wind farms decrease as the separation between wind farms increases. However, how far is far enough to reduce variability? Grid management requires balancing production on various timescales, and so consideration of correlations reflective of those timescales can guide the appropriate spatial scales of geographic diversity grid integration. To answer 'how far is far enough,' we investigate the universal behavior of geographic diversity by exploring wind-speed correlations using three extensive datasets spanning continents, durations and time resolution. First, one year of five-minute wind power generation data from 29 wind farms span 1270 km across Southeastern Australia (Australian Energy Market Operator). Second, 45 years of hourly 10 m wind-speeds from 117 stations span 5000 km across Canada (National Climate Data Archive of Environment Canada). Finally, four years of five-minute wind-speeds from 14 meteorological towers span 350 km of the Northwestern US (Bonneville Power Administration). After removing diurnal cycles and seasonal trends from all datasets, we investigate dependence of correlation length on time scale by digitally high-pass filtering the data on 0.25–2000 h timescales and calculating correlations between sites for each high-pass filter cut-off. Correlations fall to zero with increasing station separation distance, but the characteristic correlation length varies with the high-pass filter applied: the higher the cut-off frequency, the smaller the station separation required to achieve de-correlation. Remarkable similarities between these three datasets reveal behavior that, if universal, could be particularly useful for grid management. For high

Measurements of slip length for flows over graphite surface with gas domains

NASA Astrophysics Data System (ADS)

Li, Dayong; Wang, Yuliang; Pan, Yunlu; Zhao, Xuezeng

2016-10-01

We present the measurements of slip lengths for the flows of purified water over graphite surface covered with surface nanobubbles or nano/micropancakes, which can be produced after using high temperature water to replace low temperature water. The slip length values measured on bare graphite surface, nano/micropancake or nanobubble covered graphite surfaces are about 8 nm, 27 nm, and 63 nm, respectively. Our results indicate that the gaseous domains formed at the solid-liquid interface, including surface nanobubbles and nano/micropancakes, could act as a lubricant and significantly increase slip length.

Measurement of the digit lengths and the anogenital distance in mice.

PubMed

Manno, Francis Anthony Michael

2008-01-28

In humans, research has demonstrated the ratio of the 2nd to 4th digit lengths (2D:4D) are: (i) sexually dimorphic with males having a lower ratio than females, the latter having near equidistant lengths [J. Manning, D. Scutt, J. Wilson, & D. Lewis-Jones, (1998). The ratio of 2nd to 4th digit length: a predictor of sperm numbers and concentrations of testosterone, luteinizing hormone and oestrogen. Hum Reprod. 13(11):3000-3004], and are theorized to be (ii) determined in utero during gestational development [J. Manning, & P. Bundred, (2000). The ratio of 2nd to 4th digit length: a new predictor of disease predisposition? Med Hypotheses. 54(5):855-857], and (iii) correlated with prenatal androgen levels [J. Manning, & P. Bundred, (2000). The ratio of 2nd to 4th digit length: a new predictor of disease predisposition? Med Hypotheses. 54(5):855-857; J. Manning, R. Trivers, D. Singh, & R. Thornhill, (1999). The mystery of female beauty. Nature. 399:214-215; T. Williams, M. Pepitone, S. Christensen, B. Cooke, A. Huberman, N. Breedlove, et al., (2000). Finger-length ratios and sexual orientation: measuring people's finger patterns may reveal some surprising information. Nature. 404:455-456]. These phenotypes correspond to the hormonal effects of testosterone (i.e. androgens) in utero in both sexes. In mice, testosterone in utero is associated in males and females with the anogenital distance (AGD), a phenotype where AGD is greater in males and females contiguous with two males (2M) have a masculinized AGD phenotype whereas those juxtaposed to fewer males, one or zero (1M or 0M), have a more feminine phenotype, i.e. shorter AGD [F. vom Saal, & F. Bronson, (1980). Sexual characteristics of adult female mice are correlated with their blood testosterone levels during prenatal development. Science. 208:597-599; R. Gandelman, F. vom Saal, & J. Reinisch, (1977). Contiguity to male foetuses affects morphology and behaviour of female mice. Nature. 266:722-724; A. Hotchkiss, & J

Correlations between psychometric schizotypy, scan path length, fixations on the eyes and face recognition.

PubMed

Hills, Peter J; Eaton, Elizabeth; Pake, J Michael

2016-01-01

Psychometric schizotypy in the general population correlates negatively with face recognition accuracy, potentially due to deficits in inhibition, social withdrawal, or eye-movement abnormalities. We report an eye-tracking face recognition study in which participants were required to match one of two faces (target and distractor) to a cue face presented immediately before. All faces could be presented with or without paraphernalia (e.g., hats, glasses, facial hair). Results showed that paraphernalia distracted participants, and that the most distracting condition was when the cue and the distractor face had paraphernalia but the target face did not, while there was no correlation between distractibility and participants' scores on the Schizotypal Personality Questionnaire (SPQ). Schizotypy was negatively correlated with proportion of time fixating on the eyes and positively correlated with not fixating on a feature. It was negatively correlated with scan path length and this variable correlated with face recognition accuracy. These results are interpreted as schizotypal traits being associated with a restricted scan path leading to face recognition deficits.

Effect of genomic long-range correlations on DNA persistence length: from theory to single molecule experiments.

PubMed

Moukhtar, Julien; Faivre-Moskalenko, Cendrine; Milani, Pascale; Audit, Benjamin; Vaillant, Cedric; Fontaine, Emeline; Mongelard, Fabien; Lavorel, Guillaume; St-Jean, Philippe; Bouvet, Philippe; Argoul, Françoise; Arneodo, Alain

2010-04-22

Sequence dependency of DNA intrinsic bending properties has been emphasized as a possible key ingredient to in vivo chromatin organization. We use atomic force microscopy (AFM) in air and liquid to image intrinsically straight (synthetic), uncorrelated (hepatitis C RNA virus) and persistent long-range correlated (human) DNA fragments in various ionic conditions such that the molecules freely equilibrate on the mica surface before being captured in a particular conformation. 2D thermodynamic equilibrium is experimentally verified by a detailed statistical analysis of the Gaussian nature of the DNA bend angle fluctuations. We show that the worm-like chain (WLC) model, commonly used to describe the average conformation of long semiflexible polymers, reproduces remarkably well the persistence length estimates for the first two molecules as consistently obtained from (i) mean square end-to-end distance measurement and (ii) mean projection of the end-to-end vector on the initial orientation. Whatever the operating conditions (air or liquid, concentration of metal cations Mg(2+) and/or Ni(2+)), the persistence length found for the uncorrelated viral DNA underestimates the value obtained for the straight DNA. We show that this systematic difference is the signature of the presence of an uncorrelated structural intrinsic disorder in the hepatitis C virus (HCV) DNA fragment that superimposes on local curvatures induced by thermal fluctuations and that only the entropic disorder depends upon experimental conditions. In contrast, the WLC model fails to describe the human DNA conformations. We use a mean-field extension of the WLC model to account for the presence of long-range correlations (LRC) in the intrinsic curvature disorder of human genomic DNA: the stronger the LRC, the smaller the persistence length. The comparison of AFM imaging of human DNA with LRC DNA simulations confirms that the rather small mean square end-to-end distance observed, particularly for G

Comparison of Standardized Clinical Evaluation of Wounds Using Ruler Length by Width and Scout Length by Width Measure and Scout Perimeter Trace

PubMed Central

Langemo, Diane; Spahn, James; Spahn, Thomas; Pinnamaneni, V. Chowdry

2015-01-01

ABSTRACT The study objective was to examine precision in wound measurement using a recently Food and Drug Administration-approved Scout (WoundVision, LLC, Indianapolis, Indiana) device to measure wound length (L) and width (W). Wound perimeter and a ruler measurement of L and W were also made. Images of 40 actual patient wounds were measured using the Scout device. All 3 techniques (length, width, perimeter) demonstrated acceptable within and between reader precision; however, the best precision was in wound perimeter measurement. PMID:25679463

Direct Measurement of Lateral Correlations under Controlled Nanoconfinement

NASA Astrophysics Data System (ADS)

Kékicheff, P.; Iss, J.; Fontaine, P.; Johner, A.

2018-03-01

Lateral correlations along hydrophobic surfaces whose separation can be varied continuously are measured by x-ray scattering using a modified surface force apparatus coupled with synchrotron radiation, named SFAX. A weak isotropic diffuse scattering along the equatorial plane is revealed for mica surfaces rendered hydrophobic and charge neutral by immersion in cationic surfactant solutions at low concentrations. The peak corresponds to a lateral surface correlation length ξ ≈12 nm , without long-range order. These findings are compatible with the atomic force microscopy imaging of a single surface, where adsorbed surfactant stripes appear surrounded by bare mica zones. Remarkably, the scattering patterns remain stable for gap widths D larger than the lateral period but change in intensity and shape (to a lesser extent) as soon as D <ξ . This evolution codes for a redistribution of counterions (counterion release from antagonistic patches) and the associated new x-ray labeling of the patterns. The redistribution of counterions is also the key mechanism to the long-range electrostatic attraction between similar, overall charge-neutral walls, reported earlier.

Predictive value of cervical length measurement and fibronectin testing in threatened preterm labor.

PubMed

van Baaren, Gert-Jan; Vis, Jolande Y; Wilms, Femke F; Oudijk, Martijn A; Kwee, Anneke; Porath, Martina M; Oei, Guid; Scheepers, Hubertina C J; Spaanderman, Marc E A; Bloemenkamp, Kitty W M; Haak, Monique C; Bolte, Antoinette C; Bax, Caroline J; Cornette, Jérôme M J; Duvekot, Johannes J; Nij Bijvanck, Bas W A; van Eyck, Jim; Franssen, Maureen T M; Sollie, Krystyna M; Vandenbussche, Frank P H A; Woiski, Mallory; Grobman, William A; van der Post, Joris A M; Bossuyt, Patrick M M; Opmeer, Brent C; Mol, Ben W J

2014-06-01

To estimate the performance of combining cervical length measurement with fetal fibronectin testing in predicting delivery in women with symptoms of preterm labor. We conducted a prospective nationwide cohort study in all 10 perinatal centers in The Netherlands. Women with symptoms of preterm labor between 24 and 34 weeks of gestation with intact membranes were included. In all women, qualitative fibronectin testing (0.050-microgram/mL cutoff) and cervical length measurement were performed. Logistic regression was used to predict spontaneous preterm delivery within 7 days after testing. A risk less than 5%, corresponding to the risk for women with a cervical length of at least 25 mm, was considered as low risk. Between December 2009 and August 2012, 714 women were enrolled. Fibronectin results and cervical length were available for 665 women, of whom 80 (12%) delivered within 7 days. Women with a cervical length of at least 30 mm or with a cervical length between 15 and 30 mm with a negative fibronectin result were at low risk (less than 5%) of spontaneous delivery within 7 days. Fibronectin testing in case of a cervical length between 15 and 30 mm additionally classified 103 women (15% of the cohort) as low risk and 36 women (5% of the cohort) as high risk. Cervical length measurement, combined with fetal fibronectin testing in case of a cervical length between 15 and 30 mm, improves identification of women with a low risk to deliver spontaneously within 7 days. II.

Precise fiber length measurement using harmonic detection of phase-locked cavity modes

NASA Astrophysics Data System (ADS)

Terra, Osama

2018-06-01

In this paper, precise length measurements of optical fibers are performed by employing harmonic detection of the pulse-train frequency of a passively mode-locked fiber laser. This frequency is proportional to the length of the laser cavity in which the measured fiber is installed. Our proposed technique enables length measurement of long fibers from 1 to 40 km with precision from 0.4 to 8 mm and short fibers of few meters with precision as low as 26 μm. Such superior precision is achieved not only by the selection of higher harmonics of up to 1410, but also by the careful control of the wavelength at which the passive mode-locking occur, because of the broadband nature of the used gain medium.

Measuring Clearance Mechanics Based on Dynamic Leg Length

ERIC Educational Resources Information Center

Khamis, Sam; Danino, Barry; Hayek, Shlomo; Carmeli, Eli

2018-01-01

The aim of this study was to quantify clearance mechanics during gait. Seventeen children diagnosed with hemiplegic cerebral palsy underwent a three-dimensional gait analysis evaluation. Dynamic leg lengths were measured from the hip joint center to the heel, to the ankle joint center and to the forefoot throughout the gait cycle. Significant…

Estimation of Total Length of Femur from its Proximal and Distal Segmental Measurements of Disarticulated Femur Bones of Nepalese Population using Regression Equation Method.

PubMed

Khanal, Laxman; Shah, Sandip; Koirala, Sarun

2017-03-01

Length of long bones is taken as an important contributor for estimating one of the four elements of forensic anthropology i.e., stature of the individual. Since physical characteristics of the individual differ among different groups of population, population specific studies are needed for estimating the total length of femur from its segment measurements. Since femur is not always recovered intact in forensic cases, it was the aim of this study to derive regression equations from measurements of proximal and distal fragments in Nepalese population. A cross-sectional study was done among 60 dry femora (30 from each side) without sex determination in anthropometry laboratory. Along with maximum femoral length, four proximal and four distal segmental measurements were measured following the standard method with the help of osteometric board, measuring tape and digital Vernier's caliper. Bones with gross defects were excluded from the study. Measured values were recorded separately for right and left side. Statistical Package for Social Science (SPSS version 11.5) was used for statistical analysis. The value of segmental measurements were different between right and left side but statistical difference was not significant except for depth of medial condyle (p=0.02). All the measurements were positively correlated and found to have linear relationship with the femoral length. With the help of regression equation, femoral length can be calculated from the segmental measurements; and then femoral length can be used to calculate the stature of the individual. The data collected may contribute in the analysis of forensic bone remains in study population.

Research on the measurement technology of effective arm length of swing arm profilometer

NASA Astrophysics Data System (ADS)

Chen, Lin; Jing, Hongwei; Wei, Zhongwei; Li, Jie; Cao, Xuedong

2014-09-01

When the swing arm profilometer(SAP) measuring the mirror, the effective arm length of SAP which haves an obvious influence on the measurement results of the mirror surface shape needs to be measured accurately. It requires the measurement uncertainty of the effective arm length to reach 10μm in order to meet the measurement requirements, in this paper, we present a kind of technology based on laser tracker to measure the effective arm length of SAP. When the swing arm rotates around the shaft axis of swing arm rotary stage, the probe and two laser tracker balls form three sections of circular arc around the shaft axis of swing arm rotary stage in space. Laser tracker tracks and measures the circular arcs of two laser tracker balls, the center coordinates of the circular plane of circular arc can be calculated by data processing. The linear equation that passes through the two center coordinates is the equation of the shaft axis of rotary stage, the vertical distance from the probe to the shaft axis of rotary stage which can be calculated refer to the equation from the point to the line is the effective arm length. After Matlab simulation, this measurement method can meet the measurement accuracy.

Automatic measurement of pennation angle and fascicle length of gastrocnemius muscles using real-time ultrasound imaging.

PubMed

Zhou, Guang-Quan; Chan, Phoebe; Zheng, Yong-Ping

2015-03-01

Muscle imaging is a promising field of research to understand the biological and bioelectrical characteristics of muscles through the observation of muscle architectural change. Sonomyography (SMG) is a technique which can quantify the real-time architectural change of muscles under different contractions and motions with ultrasound imaging. The pennation angle and fascicle length are two crucial SMG parameters to understand the contraction mechanics at muscle level, but they have to be manually detected on ultrasound images frame by frame. In this study, we proposed an automatic method to quantitatively identify pennation angle and fascicle length of gastrocnemius (GM) muscle based on multi-resolution analysis and line feature extraction, which could overcome the limitations of tedious and time-consuming manual measurement. The method started with convolving Gabor wavelet specially designed for enhancing the line-like structure detection in GM ultrasound image. The resulting image was then used to detect the fascicles and aponeuroses for calculating the pennation angle and fascicle length with the consideration of their distribution in ultrasound image. The performance of this method was tested on computer simulated images and experimental images in vivo obtained from normal subjects. Tests on synthetic images showed that the method could identify the fascicle orientation with an average error less than 0.1°. The result of in vivo experiment showed a good agreement between the results obtained by the automatic and the manual measurements (r=0.94±0.03; p<0.001, and r=0.95±0.02, p<0.001). Furthermore, a significant correlation between the ankle angle and pennation angle (r=0.89±0.05; p<0.001) and fascicle length (r=-0.90±0.04; p<0.001) was found for the ankle plantar flexion. This study demonstrated that the proposed method was able to automatically measure the pennation angle and fascicle length of GM ultrasound images, which made it feasible to investigate

Reproducibility of telomere length assessment: an international collaborative study.

PubMed

Martin-Ruiz, Carmen M; Baird, Duncan; Roger, Laureline; Boukamp, Petra; Krunic, Damir; Cawthon, Richard; Dokter, Martin M; van der Harst, Pim; Bekaert, Sofie; de Meyer, Tim; Roos, Goran; Svenson, Ulrika; Codd, Veryan; Samani, Nilesh J; McGlynn, Liane; Shiels, Paul G; Pooley, Karen A; Dunning, Alison M; Cooper, Rachel; Wong, Andrew; Kingston, Andrew; von Zglinicki, Thomas

2015-10-01

Telomere length is a putative biomarker of ageing, morbidity and mortality. Its application is hampered by lack of widely applicable reference ranges and uncertainty regarding the present limits of measurement reproducibility within and between laboratories. We instigated an international collaborative study of telomere length assessment: 10 different laboratories, employing 3 different techniques [Southern blotting, single telomere length analysis (STELA) and real-time quantitative PCR (qPCR)] performed two rounds of fully blinded measurements on 10 human DNA samples per round to enable unbiased assessment of intra- and inter-batch variation between laboratories and techniques. Absolute results from different laboratories differed widely and could thus not be compared directly, but rankings of relative telomere lengths were highly correlated (correlation coefficients of 0.63-0.99). Intra-technique correlations were similar for Southern blotting and qPCR and were stronger than inter-technique ones. However, inter-laboratory coefficients of variation (CVs) averaged about 10% for Southern blotting and STELA and more than 20% for qPCR. This difference was compensated for by a higher dynamic range for the qPCR method as shown by equal variance after z-scoring. Technical variation per laboratory, measured as median of intra- and inter-batch CVs, ranged from 1.4% to 9.5%, with differences between laboratories only marginally significant (P = 0.06). Gel-based and PCR-based techniques were not different in accuracy. Intra- and inter-laboratory technical variation severely limits the usefulness of data pooling and excludes sharing of reference ranges between laboratories. We propose to establish a common set of physical telomere length standards to improve comparability of telomere length estimates between laboratories. © The Author 2014. Published by Oxford University Press on behalf of the International Epidemiological Association.

Scale and time dependence of serial correlations in word-length time series of written texts

NASA Astrophysics Data System (ADS)

Rodriguez, E.; Aguilar-Cornejo, M.; Femat, R.; Alvarez-Ramirez, J.

2014-11-01

This work considered the quantitative analysis of large written texts. To this end, the text was converted into a time series by taking the sequence of word lengths. The detrended fluctuation analysis (DFA) was used for characterizing long-range serial correlations of the time series. To this end, the DFA was implemented within a rolling window framework for estimating the variations of correlations, quantified in terms of the scaling exponent, strength along the text. Also, a filtering derivative was used to compute the dependence of the scaling exponent relative to the scale. The analysis was applied to three famous English-written literary narrations; namely, Alice in Wonderland (by Lewis Carrol), Dracula (by Bram Stoker) and Sense and Sensibility (by Jane Austen). The results showed that high correlations appear for scales of about 50-200 words, suggesting that at these scales the text contains the stronger coherence. The scaling exponent was not constant along the text, showing important variations with apparent cyclical behavior. An interesting coincidence between the scaling exponent variations and changes in narrative units (e.g., chapters) was found. This suggests that the scaling exponent obtained from the DFA is able to detect changes in narration structure as expressed by the usage of words of different lengths.

Importance of the Correlation between Width and Length in the Shape Analysis of Nanorods: Use of a 2D Size Plot To Probe Such a Correlation.

PubMed

Zhao, Zhihua; Zheng, Zhiqin; Roux, Clément; Delmas, Céline; Marty, Jean-Daniel; Kahn, Myrtil L; Mingotaud, Christophe

2016-08-22

Analysis of nanoparticle size through a simple 2D plot is proposed in order to extract the correlation between length and width in a collection or a mixture of anisotropic particles. Compared to the usual statistics on the length associated with a second and independent statistical analysis of the width, this simple plot easily points out the various types of nanoparticles and their (an)isotropy. For each class of nano-objects, the relationship between width and length (i.e., the strong or weak correlations between these two parameters) may suggest information concerning the nucleation/growth processes. It allows one to follow the effect on the shape and size distribution of physical or chemical processes such as simple ripening. Various electron microscopy pictures from the literature or from the authors' own syntheses are used as examples to demonstrate the efficiency and simplicity of the proposed 2D plot combined with a multivariate analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of various digital processing algorithms on the measurement accuracy of endodontic file length.

PubMed

Kal, Betül Ilhan; Baksi, B Güniz; Dündar, Nesrin; Sen, Bilge Hakan

2007-02-01

The aim of this study was to compare the accuracy of endodontic file lengths after application of various image enhancement modalities. Endodontic files of three different ISO sizes were inserted in 20 single-rooted extracted permanent mandibular premolar teeth and standardized images were obtained. Original digital images were then enhanced using five processing algorithms. Six evaluators measured the length of each file on each image. The measurements from each processing algorithm and each file size were compared using repeated measures ANOVA and Bonferroni tests (P = 0.05). Paired t test was performed to compare the measurements with the true lengths of the files (P = 0.05). All of the processing algorithms provided significantly shorter measurements than the true length of each file size (P < 0.05). The threshold enhancement modality produced significantly higher mean error values (P < 0.05), while there was no significant difference among the other enhancement modalities (P > 0.05). Decrease in mean error value was observed with increasing file size (P < 0.05). Invert, contrast/brightness and edge enhancement algorithms may be recommended for accurate file length measurements when utilizing storage phosphor plates.

Penile length and circumference: an Indian study.

PubMed

Promodu, K; Shanmughadas, K V; Bhat, S; Nair, K R

2007-01-01

Apprehension about the normal size of penis is a major concern for men. Aim of the present investigation is to estimate the penile length and circumference of Indian males and to compare the results with the data from other countries. Results will help in counseling the patients worried about the penile size and seeking penis enlargement surgery. Penile length in flaccid and stretched conditions and circumference were measured in a group of 301 physically normal men. Erected length and circumference were measured for 93 subjects. Mean flaccid length was found to be 8.21 cm, mean stretched length 10.88 cm and circumference 9.14 cm. Mean erected length was found to be 13.01 cm and erected circumference was 11.46 cm. Penile dimensions are found to be correlated with anthropometric parameters. Insight into the normative data of penile size of Indian males obtained. There are significant differences in the mean penile length and circumference of Indian sample compared to the data reported from other countries. Study need to be continued with a large sample to establish a normative data applicable to the general population.

The elementary school teachers’ ability in the length measurement

NASA Astrophysics Data System (ADS)

Julie, Hongki

2017-09-01

The purpose of this study was to describe the elementary school teachers' mathematical ability (1) to develop students’ activities which constructed longer than, shorter than, and as long as concepts, (2) to develop students’ activities which constructed standard unit on the length measurement, and (3) to develop a problem which used by student to construct why a conversion activity on the unit of the length was useful in the daily life after they have participated in the Realistic Mathematics Education (RME) workshops. Curry and Outhread said if teachers knew more about the growth of students’ conceptual understanding of the length, they would be better able to teach that topic [4]. Therefore, in the workshop, teachers were asked to learn more on the stages of the measurement teaching and learning process and why each stage was important. This capability was described by the results of a test which was content of four problems given to teachers after they have attended the workshop. Research subjects in this study were 14 elementary school teachers at Yogyakarta. The results of the study were as follows: (1) only four of 14 teachers who had the first ability; (2) all teachers had the second ability; and (3) all the teachers did not have the third ability.

Fetal kidney length as a useful adjunct parameter for better determination of gestational age.

PubMed

Ugur, Mete G; Mustafa, Aynur; Ozcan, Huseyin C; Tepe, Neslihan B; Kurt, Huseyin; Akcil, Emre; Gunduz, Reyhan

2016-05-01

To determine the validity of fetal kidney length and amniotic fluid index (AFI) in labor dating.  This prospective study included 180 pregnant women followed up in the outpatient clinic at the Department of Obstetrics and Gynecology, Gaziantep University, Turkey, between January 2014 and January 2015. The gestational age (GA) was estimated by early fetal ultrasound measures and last menstrual period. Routine fetal biometric parameters, fetal kidney length, and amniotic fluid index were measured. We studied the correlation between fetal kidney length, amniotic fluid index, and gestational age.  The mean gestational age depending on last menstrual period and early ultrasound was 31.98±4.29 (24-39 weeks). The mean kidney length was 35.66±6.61 (19-49 mm). There was a significant correlation between gestational age and fetal kidney length (r=0.947, p=0.001). However, there was a moderate negative correlation between GA and AFI. Adding fetal kidney length to the routine biometrics improved the effectiveness of the model used to estimate GA (R2=0.965 to R2=0.987).  Gestational age can be better predicted by adding fetal kidney length to other routine parameters.

Nasal bone length in human fetuses by X-ray.

PubMed

Moura, Felipe Nobre; Fernandes, Pablo Lourenco; de Oliveira Silva-Junior, Geraldo; Gomes de Souza, Margareth Maria; Mandarim-de-Lacerda, Carlos Alberto

2008-07-01

To construct a normal range for the prenatal nasal bone length (NBL) in Brazilians irrespective to the knowledge of the ethnic genetic background. We studied 35 human fetuses (20 males, 15 females) ranging from 14 to 22 weeks of gestation. Gestational age (GA), crown-rump length (CRL), foot length (FL) and body mass (BM) were measured. The X-ray of the head lateral view was made with the specimens placed directly on the film and the NBL was measured. The NBL was correlated with the GA, the CRL, the FL, and the BM using log-transformed data and the allometric model log y=log a+b log x. Correlations of the NBL growth with GA, CRL, FL, and BM were positive and significant (P<0.05), but NBL vs. BM showed the smallest R indicating this correlation as of little practical use. No sexual dimorphism in the NBL growth in the second trimester fetuses was observed. The NBL grew with positive allometry relative to GA, CRL and BM, but it was allometrically slightly negative relative to the FL in both genders. The NBL be allometrically positive against GA, CRL and BM means the bone grew with growth rates higher than those indices in the period analyzed, but not against FL. NBL could be considered an auxiliary measurement in the assessment of the 2nd trimester fetal development because its strong correlation with GA, CRL and FL, even when nothing is known about the ethnicity of the population.

Lifetime and diffusion length measurements on silicon material and solar cells

NASA Technical Reports Server (NTRS)

Othmer, S.; Chen, S. C.

1978-01-01

Experimental methods were evaluated for the determination of lifetime and diffusion length in silicon intentionally doped with potentially lifetime-degrading impurities found in metallurgical grade silicon, impurities which may be residual in low-cost silicon intended for use in terrestrial flat-plate arrays. Lifetime measurements were made using a steady-state photoconductivity method. Diffusion length determinations were made using short-circuit current measurements under penetrating illumination. Mutual consistency among all experimental methods was verified, but steady-state photoconductivity was found preferable to photoconductivity decay at short lifetimes and in the presence of traps. The effects of a number of impurities on lifetime in bulk material, and on diffusion length in cells fabricated from this material, were determined. Results are compared with those obtained using different techniques. General agreement was found in terms of the hierarchy of impurities which degrade the lifetime.

Sella size and jaw bases - Is there a correlation???

PubMed

Neha; Mogra, Subraya; Shetty, Vorvady Surendra; Shetty, Siddarth

2016-01-01

Sella turcica is an important cephalometric structure and attempts have been made in the past to correlate its dimensions to the malocclusion. However, no study has so far compared the size of sella to the jaw bases that determine the type of malocclusion. The present study was undertaken to find out any such correlation if it exists. Lateral cephalograms of 110 adults consisting of 40 Class I, 40 Class II, and 30 Class III patients were assessed for the measurement of sella length, width, height, and area. The maxillary length, mandibular ramus height, and body length were also measured. The sella dimensions were compared among three malocclusion types by one-way ANOVA. Pearson correlation was calculated between the jaw size and sella dimensions. Furthermore, the ratio of jaw base lengths and sella area were calculated. Mean sella length, width and area were found to be greatest in Class III, followed by Class I and least in Class II though the results were not statistically significant. 3 out of 4 measured dimensions of sella, correlated significantly with mandibular ramus and body length each. However, only one dimension of sella showed significant correlation with maxilla. The mandibular ramus and body length show a nearly constant ratio to sella area (0.83-0.85, 0.64-0.65, respectively) in all the three malocclusions. Thus, mandible has a definite and better correlation to the size of sella turcica.

Experience of the fibrotest for measuring cotton fiber length and strength properties

USDA-ARS?s Scientific Manuscript database

The Fibrotest is a device developed by Textechno for measuring cotton fiber length and strength properties. The Fibrotest provides abundant information, including more than 20 length and strength parameters in absolute and relative modes, and displays fibrogram, load-elongation curve, and fiber bea...

Bunch Length Measurements at the JLab FEL Using Coherent Transition and Synchrotron Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavel Evtushenko; James Coleman; Kevin Jordan

2006-05-01

The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years [1]. This diagnostic can be used only in the pulsed beam mode. It is our goal to run the FEL with CW beam and a 74.85 MHz micropulse repetition rate, which, with the 135 pC nominal bunch charge corresponds to the beam average current of 10 mA. Hence it is very desirable to have the possibility of making bunch length measurements when running CW beammore » with any micropulse frequency. We use a Fourier transform infrared (FTIR) interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with data obtained using the Martin-Puplett interferometer [1]. Results of the two diagnostics agree within 15 %. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.« less

Bunch Length Measurements at the JLab FEL Using Coherent Transition and Synchrotron Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evtushenko, P.; Coleman, J.; Jordan, K.

2006-11-20

The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years. This diagnostic can be used only in the pulsed beam mode. It is our goal to run the FEL with CW beam and a 74.85 MHz micropulse repetition rate, which, with the 135 pC nominal bunch charge corresponds to the beam average current of 10 mA, Hence it is very desirable to have the possibility of making bunch length measurements when running CW beam withmore » any micropulse frequency. We use a Fourier transform infrared (FTIR) interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with data obtained using the Martin-Puplett interferometer. Results of the two diagnostics agree within 15 %. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.« less

Intra- and Interobserver Variability of Cochlear Length Measurements in Clinical CT.

PubMed

Iyaniwura, John E; Elfarnawany, Mai; Riyahi-Alam, Sadegh; Sharma, Manas; Kassam, Zahra; Bureau, Yves; Parnes, Lorne S; Ladak, Hanif M; Agrawal, Sumit K

2017-07-01

The cochlear A-value measurement exhibits significant inter- and intraobserver variability, and its accuracy is dependent on the visualization method in clinical computed tomography (CT) images of the cochlea. An accurate estimate of the cochlear duct length (CDL) can be used to determine electrode choice, and frequency map the cochlea based on the Greenwood equation. Studies have described estimating the CDL using a single A-value measurement, however the observer variability has not been assessed. Clinical and micro-CT images of 20 cadaveric cochleae were acquired. Four specialists measured A-values on clinical CT images using both standard views and multiplanar reconstructed (MPR) views. Measurements were repeated to assess for intraobserver variability. Observer variabilities were evaluated using intra-class correlation and absolute differences. Accuracy was evaluated by comparison to the gold standard micro-CT images of the same specimens. Interobserver variability was good (average absolute difference: 0.77 ± 0.42 mm) using standard views and fair (average absolute difference: 0.90 ± 0.31 mm) using MPR views. Intraobserver variability had an average absolute difference of 0.31 ± 0.09 mm for the standard views and 0.38 ± 0.17 mm for the MPR views. MPR view measurements were more accurate than standard views, with average relative errors of 9.5 and 14.5%, respectively. There was significant observer variability in A-value measurements using both the standard and MPR views. Creating the MPR views increased variability between experts, however MPR views yielded more accurate results. Automated A-value measurement algorithms may help to reduce variability and increase accuracy in the future.

Foot length, chest and head circumference measurements in detection of Low birth weight neonates in Mekelle, Ethiopia: a hospital based cross sectional study.

PubMed

Hadush, Marta Yemane; Berhe, Amanuel Hadgu; Medhanyie, Araya Abrha

2017-04-21

Low birth weight (Birth weight < 2500 g) is a leading cause of prenatal and neonatal deaths. The early identification of Low birth weight (LBW) neonates is essential for any comprehensive initiative to improve their chance of survival. However, a large proportion of births in developing countries take place at home and birth weight statistics are not available. Therefore, there is a need to develop simple, inexpensive and practical methods to identify low birth weight (LBW) neonates soon after birth. This is a hospital based cross sectional study. Four hundred twenty two (422) live born neonates were included and anthropometric measurements were carried out within 24 h of birth by three trained nurses. Birth weight was measured by digital scale. Head and chest circumference were measured by using non extendable measuring tape and foot length with hard transparent plastic ruler. Data was entered into SPSS version 20 for analysis. Characteristics of study participants were analyzed using descriptive statistics such as frequency and percentage for categorical data and mean and standard deviation for continuous data. Correlation with birth weight using Pearson's correlation coefficient and linear regression were used to identify the association between dependent and independent variables. Receiver operating characteristic (ROC) curve was used to evaluate accuracy of the anthropometric measurements to predict LBW. The prevalence of low birth weight was found to be 27%. All anthropometric measurements had a positive correlation with birth weight, chest circumference attaining the highest correlation with birth weight (r = 0.85) and foot length had the weakest correlation (r = 0.74). Head circumference had the highest predictive value for birth weight (AUC = 0.93) followed by Chest circumference (AUC = 0.91). A cut off point of chest circumference 30.15 cm had 84.2% sensitivity, 85.4% specificity and diagnostic accuracy (P < 0.001). A cut off

Within arm's reach: Measuring forearm length to assess growth patterns in captive bonobos and chimpanzees.

PubMed

Behringer, Verena; Stevens, Jeroen M G; Kivell, Tracy L; Neufuss, Johanna; Boesch, Christophe; Hohmann, Gottfried

2016-09-01

Bonobos and chimpanzees are known to differ in various morphological traits, a dichotomy that is sometimes used as an analogy for evolutionary splits during human evolution. The aim of our study was to measure the forearm length of immature and adult bonobos and adult chimpanzees to assess the extent of age-related changes of forearm length in bonobos and sex-dimorphism in bonobos and chimpanzees. As a proxy of somatic growth we measured forearm length of captive bonobos and chimpanzees ranging in age from 1 to 55 years. Measures were taken from subjects inserting their arms into a transparent Plexiglas® tube, a novel technique facilitating repeated measures of nonanesthetized apes in captivity. Measures from adult females (>12 years) showed that bonobos exceed chimpanzees in terms of forearm length and that sexual dimorphism in forearm length is pronounced in chimpanzees, but not in bonobos. Forearm length increased significantly with chronological age in bonobos. Validation tests revealed that the device generates useful data on morphometric dimensions. In most primates, sexual dimorphism in body size is male-biased and the differences in forearm length in chimpanzees follow this trend. Given that males of the two species did not differ in forearm length, the absence/presence of sexual dimorphism of this trait must be due to differences in somatic growth in females. Our novel method offers an alternative to obtain morphometric measures and facilitates longitudinal studies on somatic growth. Am J Phys Anthropol 161:37-43, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A New Frequency-Domain Method for Bunch Length Measurement

NASA Astrophysics Data System (ADS)

Ferianis, M.; Pros, M.

1997-05-01

A new method for bunch length measurements has been developed at Elettra. It is based on a spectral observation of the synchrotron radiation light pulses. The single pulse spectrum is shaped by means of an optical process which gives the method an increased sensitivity compared to the usual spectral observations. Some simulations have been carried out to check the method in non-ideal conditions. The results of the first measurements are also presented.

Reliability of length measurements collected by community nurses and health volunteers in rural growth monitoring and promotion services.

PubMed

Laar, Matilda E; Marquis, Grace S; Lartey, Anna; Gray-Donald, Katherine

2018-02-17

Length measurements are important in growth, monitoring and promotion (GMP) for the surveillance of a child's weight-for-length and length-for-age. These two indices provide an indication of a child's risk of becoming wasted or stunted, and are more informative about a child's growth than the widely used weight-for-age index (underweight). Although the introduction of length measurements in GMP is recommended by the World Health Organization, concerns about the reliability of length measurements collected in rural outreach settings have been expressed by stakeholders. Our aim was to describe the reliability and challenges associated with community health personnel measuring length for rural outreach GMP activities. Two reliability studies (A and B), using 10 children less than 24 months each, were conducted in the GMP services of a rural district in Ghana. Fifteen nurses and 15 health volunteers (HV) with no prior experience in length measurements were trained. Intra- and inter-observer technical error of measurement (TEM), average bias from expert anthropometrist, and coefficient of reliability (R) of length measurements were assessed and compared across sessions. Observations and interviews were used to understand the ability and experiences of health personnel with measuring length at outreach GMP. Inter-observer TEM was larger than intra-observer TEM for both nurses and HV at both sessions and was unacceptably (compared to error standards) high in both groups at both time points. Average biases from expert's measurements were within acceptable limits, however, both groups tended to underestimate length measurements. The R for lengths collected by nurses (92.3%) was higher at session B compared to that of HV (87.5%). Length measurements taken by nurses and HV, and those taken by an experienced anthropometrist at GMP sessions were of moderate agreement (kappa = 0.53, p < 0.0001). The reliability of length measurements improved after two refresher

Ozone Correlative Measurements Workshop

NASA Technical Reports Server (NTRS)

Hilsenrath, E. (Editor)

1985-01-01

A study was conducted to determine the necessary parameters for the correlation of data on Earth ozone. Topics considered were: (1) measurement accuracy; (2) equipment considerations (SBUV); and (3) ground based measurements to support satellite data.

Reducing trial length in force platform posturographic sleep deprivation measurements

NASA Astrophysics Data System (ADS)

Forsman, P.; Hæggström, E.; Wallin, A.

2007-09-01

Sleepiness correlates with sleep-related accidents, but convenient tests for sleepiness monitoring are scarce. The posturographic test is a method to assess balance, and this paper describes one phase of the development of a posturographic sleepiness monitoring method. We investigated the relationship between trial length and accuracy of the posturographic time-awake (TA) estimate. Twenty-one healthy adults were kept awake for 32 h and their balance was recorded, 16 times with 30 s trials, as a function of TA. The balance was analysed with regards to fractal dimension, most common sway amplitude and time interval for open-loop stance control. While a 30 s trial allows estimating the TA of individual subjects with better than 5 h accuracy, repeating the analysis using shorter trial lengths showed that 18 s sufficed to achieve the targeted 5 h accuracy. Moreover, it was found that with increasing TA, the posturographic parameters estimated the subjects' TA more accurately.

Vocal tract length and formant frequency dispersion correlate with body size in rhesus macaques.

PubMed

Fitch, W T

1997-08-01

Body weight, length, and vocal tract length were measured for 23 rhesus macaques (Macaca mulatta) of various sizes using radiographs and computer graphic techniques. linear predictive coding analysis of tape-recorded threat vocalizations were used to determine vocal tract resonance frequencies ("formants") for the same animals. A new acoustic variable is proposed, "formant dispersion," which should theoretically depend upon vocal tract length. Formant dispersion is the averaged difference between successive formant frequencies, and was found to be closely tied to both vocal tract length and body size. Despite the common claim that voice fundamental frequency (F0) provides an acoustic indication of body size, repeated investigations have failed to support such a relationship in many vertebrate species including humans. Formant dispersion, unlike voice pitch, is proposed to be a reliable predictor of body size in macaques, and probably many other species.

Efficient measurement of point-to-set correlations and overlap fluctuations in glass-forming liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berthier, Ludovic; Charbonneau, Patrick; Department of Physics, Duke University, Durham, North Carolina 27708

Cavity point-to-set correlations are real-space tools to detect the roughening of the free-energy landscape that accompanies the dynamical slowdown of glass-forming liquids. Measuring these correlations in model glass formers remains, however, a major computational challenge. Here, we develop a general parallel-tempering method that provides orders-of-magnitude improvement for sampling and equilibrating configurations within cavities. We apply this improved scheme to the canonical Kob-Andersen binary Lennard-Jones model for temperatures down to the mode-coupling theory crossover. Most significant improvements are noted for small cavities, which have thus far been the most difficult to study. This methodological advance also enables us to study amore » broader range of physical observables associated with thermodynamic fluctuations. We measure the probability distribution of overlap fluctuations in cavities, which displays a non-trivial temperature evolution. The corresponding overlap susceptibility is found to provide a robust quantitative estimate of the point-to-set length scale requiring no fitting. By resolving spatial fluctuations of the overlap in the cavity, we also obtain quantitative information about the geometry of overlap fluctuations. We can thus examine in detail how the penetration length as well as its fluctuations evolve with temperature and cavity size.« less

Ultrashort electron bunch length measurement with diffraction radiation deflector

NASA Astrophysics Data System (ADS)

Xiang, Dao; Huang, Wen-Hui

2007-01-01

In this paper, we propose a novel method to measure electron bunch length with a diffraction radiation (DR) deflector which is composed of a DR radiator and three beam position monitors (BPMs). When an electron beam passes through a metallic aperture which is tilted by 45 degrees with respect to its trajectory, backward DR that propagates perpendicular to the beam’s trajectory is generated which adds a transverse deflection to the beam as a result of momentum conservation. The deflection is found to be largely dependent on the bunch length and could be easily observed with a downstream BPM. Detailed investigations show that this method has wide applicability, high temporal resolution, and great simplicity.

Bunch Length Measurements at the ATF Damping Ring in April 2000

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bane, K.L.F.; /SLAC; Naito, T.

We want to accurately know the energy spread and bunch length dependence on current in the ATF damping ring. One reason is to know the strength of the impedance: From the energy spread measurements we know whether or not we are above the threshold to the microwave instability, and from the energy spread and bunch length measurements we find out the extent of potential-well bunch lengthening (PWBL). Another reason for these measurements is to help in our understanding of the intra-beam scattering (IBS) effect in the ATF. The ATF as it is now, running below design energy and with themore » wigglers turned off, is strongly affected by IBS. To check for consistency with IBS theory of, for example, the measured vertical beam size, we need to know all dimensions of the beam, including the longitudinal one. But beyond this practical reason for studying IBS, IBS is currently a hot research topic at many accelerators around the world (see e.g. Ref. [1]), and the effect in actual machines is not well understood. Typically, when comparing theory with measurements fudge factors are needed to get agreement (see e.g. Ref. [1]). With its strong IBS effect, the ATF is an ideal machine for studying IBS, and an indispensable ingredient for this study is a knowledge of the longitudinal phase space of the beam. The results of earlier bunch lengthening measurements in the ATF can be found in Refs. [2]-[4]. Measurements of current dependent effects, especially bunch length measurements using a streak camera, can be difficult to perform accurately. For example, space charge in the camera itself can lead to systematic errors in the measurement results. It is important the results be accurate and reproducible. In the measurements of both December 1998[3] and December 1999[4], by using light filters, the authors first checked that space charge in the streak camera was not significant. And then the Dec 99 authors show that their results agree with those Dec 98, i.e. on the dates of the two

Correlating Corneal Biomechanics and Ocular Biometric Properties with Lamina Cribrosa Measurements in Healthy Subjects.

PubMed

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.

Two independent measurements of Debye lengths in doped nonpolar liquids.

PubMed

Prieve, D C; Hoggard, J D; Fu, R; Sides, P J; Bethea, R

2008-02-19

Electric current measurements were performed between 2.5 cm x 7.5 cm parallel-plate electrodes separated by 1.2 mm of heptane doped with 0-15% w/w poly(isobutylene succinimide) (PIBS) having a molecular weight of about 1700. The rapid (microsecond) initial charging of the capacitor can be used to infer the dielectric constant of the solution. The much slower decay of current arising from the polarization of electrodes depends on the differential capacitance of the diffuse clouds of charge carriers accumulating next to each electrode and on the ohmic resistance of the fluid. Using the Gouy-Chapman model for the differential capacitance, Debye lengths of 80-600 nm were deduced that decrease with increasing concentration of PIBS. Values of the Debye lengths were confirmed by performing independent measurements of double-layer repulsion between a 6 microm polystyrene (PS) latex sphere and a PS-coated glass plate using total internal reflection microscopy in the same solutions. The charge carriers appear to be inverted PIBS micelles having apparent Stokes diameters of 20-40 nm. Dynamic light scattering reveals a broad distribution of sizes having an intensity-averaged diameter of 15 nm. This smaller size might arise (1) from overestimating the electrophoretic mobility of micelles by treating them as point charges or (2) because charged micelles are larger on average than uncharged micelles. When Faradaic reactions and zeta potentials on the electrodes can be neglected, such current versus time experiments yield values for the Debye length and ionic strength with less effort than force measurements. To obtain the concentration of charge carriers from measurements of conductivity, the mobility of the charge carriers must be known.

Effect of e-learning on quality of cervical-length measurements.

PubMed

van Os, M A; van der Ven, A J; Bloemendaal, P M; Pajkrt, E; de Groot, C J M; Mol, B W J; Haak, M C

2015-09-01

To assess the effect of implementation of a newly developed e-learning module on the quality of cervical-length measurements. With the introduction of cervical-length (CL) measurement in a research setting, a CL measurement e-learning module (CLEM) was developed with the purpose to enhance the knowledge and skills of experienced ultrasonographers. CLEM was designed specifically for ultrasonographers who perform ultrasound in a general obstetrical practice but who do not regularly perform CL measurements. CLEM consists of five theoretical questions and three caliper-placement tests to learn the CL measurement technique. The quality of the CL measurements of CLEM participants was compared with images of non-participants using a CL measurement image score (CIS), defined as the sum of six items which assess the quality of the image. Each CLEM participant submitted five CL images and the images of non-CLEM participants were selected randomly from an ultrasound database. The CIS of the CLEM participants (n = 61) were significantly higher than those of non-CLEM participants (n = 23) (164.9 vs 155.6, respectively; P = 0.03). Visualization of the internal os and positioning of the calipers on the internal and external ora were found to have significantly higher CIS among the CLEM participants than among the non-CLEM participants (P = 0.001 and P < 0.001, respectively). Introducing CLEM may improve the quality of CL measurements obtained by trained and untrained sonographers. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Noninvasive measurement of dynamic correlation functions

NASA Astrophysics Data System (ADS)

Uhrich, Philipp; Castrignano, Salvatore; Uys, Hermann; Kastner, Michael

2017-08-01

The measurement of dynamic correlation functions of quantum systems is complicated by measurement backaction. To facilitate such measurements we introduce a protocol, based on weak ancilla-system couplings, that is applicable to arbitrary (pseudo)spin systems and arbitrary equilibrium or nonequilibrium initial states. Different choices of the coupling operator give access to the real and imaginary parts of the dynamic correlation function. This protocol reduces disturbances due to the early-time measurements to a minimum, and we quantify the deviation of the measured correlation functions from the theoretical, unitarily evolved ones. Implementations of the protocol in trapped ions and other experimental platforms are discussed. For spin-1 /2 models and single-site observables we prove that measurement backaction can be avoided altogether, allowing for the use of ancilla-free protocols.

Desert bird associations with broad-scale boundary length: Applications in avian conservation

USGS Publications Warehouse

Gutzwiller, K.J.; Barrow, W.C.

2008-01-01

1. Current understanding regarding the effects of boundaries on bird communities has originated largely from studies of forest-non-forest boundaries in mesic systems. To assess whether broad-scale boundary length can affect bird community structure in deserts, and to identify patterns and predictors of species' associations useful in avian conservation, we studied relations between birds and boundary-length variables in Chihuahuan Desert landscapes. Operationally, a boundary was the border between two adjoining land covers, and broad-scale boundary length was the total length of such borders in a large area. 2. Within 2-km radius areas, we measured six boundary-length variables. We analysed bird-boundary relations for 26 species, tested for assemblage-level patterns in species' associations with boundary-length variables, and assessed whether body size, dispersal ability and cowbird-host status were correlates of these associations. 3. The abundances or occurrences of a significant majority of species were associated with boundary-length variables, and similar numbers of species were related positively and negatively to boundary-length variables. 4. Disproportionately small numbers of species were correlated with total boundary length, land-cover boundary length and shrubland-grassland boundary length (variables responsible for large proportions of boundary length). Disproportionately large numbers of species were correlated with roadside boundary length and riparian vegetation-grassland boundary length (variables responsible for small proportions of boundary length). Roadside boundary length was associated (positively and negatively) with the most species. 5. Species' associations with boundary-length variables were not correlated with body size, dispersal ability or cowbird-host status. 6. Synthesis and applications. For the species we studied, conservationists can use the regressions we report as working models to anticipate influences of boundary-length changes

Maximum step length: relationships to age and knee and hip extensor capacities.

PubMed

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2007-07-01

Maximum Step Length may be used to identify older adults at increased risk for falls. Since leg muscle weakness is a risk factor for falls, we tested the hypotheses that maximum knee and hip extension speed, strength, and power capacities would significantly correlate with Maximum Step Length and also that the "step out and back" Maximum Step Length [Medell, J.L., Alexander, N.B., 2000. A clinical measure of maximal and rapid stepping in older women. J. Gerontol. A Biol. Sci. Med. Sci. 55, M429-M433.] would also correlate with the Maximum Step Length of its two sub-tasks: stepping "out only" and stepping "back only". These sub-tasks will be referred to as versions of Maximum Step Length. Unimpaired younger (N=11, age=24[3]years) and older (N=10, age=73[5]years) women performed the above three versions of Maximum Step Length. Knee and hip extension speed, strength, and power capacities were determined on a separate day and regressed on Maximum Step Length and age group. Version and practice effects were quantified and subjective impressions of test difficulty recorded. Hypotheses were tested using linear regressions, analysis of variance, and Fisher's exact test. Maximum Step Length explained 6-22% additional variance in knee and hip extension speed, strength, and power capacities after controlling for age group. Within- and between-block and test-retest correlation values were high (>0.9) for all test versions. Shorter Maximum Step Lengths are associated with reduced knee and hip extension speed, strength, and power capacities after controlling for age. A single out-and-back step of maximal length is a feasible, rapid screening measure that may provide insight into underlying functional impairment, regardless of age.

Microscopic optical path length difference and polarization measurement system for cell analysis

NASA Astrophysics Data System (ADS)

Satake, H.; Ikeda, K.; Kowa, H.; Hoshiba, T.; Watanabe, E.

2018-03-01

In recent years, noninvasive, nonstaining, and nondestructive quantitative cell measurement techniques have become increasingly important in the medical field. These cell measurement techniques enable the quantitative analysis of living cells, and are therefore applied to various cell identification processes, such as those determining the passage number limit during cell culturing in regenerative medicine. To enable cell measurement, we developed a quantitative microscopic phase imaging system based on a Mach-Zehnder interferometer that measures the optical path length difference distribution without phase unwrapping using optical phase locking. The applicability of our phase imaging system was demonstrated by successful identification of breast cancer cells amongst normal cells. However, the cell identification method using this phase imaging system exhibited a false identification rate of approximately 7%. In this study, we implemented a polarimetric imaging system by introducing a polarimetric module to one arm of the Mach-Zehnder interferometer of our conventional phase imaging system. This module was comprised of a quarter wave plate and a rotational polarizer on the illumination side of the sample, and a linear polarizer on the optical detector side. In addition, we developed correction methods for the measurement errors of the optical path length and birefringence phase differences that arose through the influence of elements other than cells, such as the Petri dish. As the Petri dish holding the fluid specimens was transparent, it did not affect the amplitude information; however, the optical path length and birefringence phase differences were affected. Therefore, we proposed correction of the optical path length and birefringence phase for the influence of elements other than cells, as a prerequisite for obtaining highly precise phase and polarimetric images.

Correlations of Clinical and Laboratory Measures of Balance in Older Men and Women: The MOBILIZE Boston Study

PubMed Central

Nguyen, Uyen-Sa D.T.; Kiel, Douglas P.; Li, Wenjun; Galica, Andrew M.; Kang, Hyun Gu; Casey, Virginia A.; Hannan, Marian T.

2012-01-01

Objective Impaired balance is associated with falls in older adults. However, there is no accepted gold standard on how balance should be measured. Few studies have examined measures of postural sway and clinical balance concurrently in large samples of community-dwelling older adults. We examined the associations among four types of measures of laboratory- and clinic-based balance in a large population-based cohort of older adults. Methods We evaluated balance measures in the MOBILIZE Boston Study (276 men, 489 women, 64–97 years). Measures included: (1) laboratory-based anteroposterior (AP) path length and average sway speed, mediolateral (ML) average sway and root-mean-square, and area of ellipse postural sway; (2) Short Physical Performance Battery (SPPB); (3) Berg Balance Scale; and (4) one-leg stand. Spearman Rank Correlation Coefficients (r) were assessed among the balance measures. Results Area of ellipse sway was highly correlated with the ML sway measures (r >0.9, p < 0.0001), and sway speed was highly correlated with AP sway (r=0.97, p < 0.0001). The Berg Balance Scale was highly correlated with SPPB (r=0.7, p<0.001), and one-leg stand (r=0.8, p<0.001). Correlations between the laboratory- and clinic-based balance measures were low but statistically significant (0.2 < r < 0.3, p<0.0001). Conclusion Clinic-based balance measures, and laboratory-based measures comparing area of ellipse with ML sways or sway speed with AP sway, are highly correlated. Clinic- with laboratory-based measures are less correlated. As both laboratory- and clinic-based measures inform balance in older adults but are not highly correlated with each other, future work should investigate the differences. PMID:22745045

Predictive formula for the length of tibial tunnel in anterior crucitate ligament reconstruction.

PubMed

Chernchujit, Bancha; Barthel, Thomas

2009-12-01

The anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon bone graft is a common procedure in orthopedics. One challenging problem found is a graft-tunnel mismatch. Previous studies have reported the mathematic formula to predict the tibial angle length and angle to avoid graft-tunnel mismatch but these formulas have shown limited predictability. To propose a predictive formula for the length of tibial tunnel and to examine its predictability. Thirty six patients (26 males, 14 females) with ACL injury were included in this study. The preoperativemedial proximal tibial angle was measured. Intraoperatively, the tibial tunnel length and tibial entry point were measured. The postoperative coronal and saggital angle of tibial tunnel were measured from knee radiograph. The data were analysed by using trigonometry correlation and formulate the predictive formula of tibial tunnel length. We found that tibial tunnel length (T) has trigonometric correlation between the location of tibial tunnel entry point (w), coronal angle of tibial tunnel (b), saggital angle of tibial tunnel (a) and the medial proximal tibial slope (c) by using this formula T = Wcos(c)tan(b)/sin(a) This proposed predictive formula can well predict the length of the tibial tunnel at preoperative period to avoid graft-tunnel mismatch.

A new sampling method for fibre length measurement

NASA Astrophysics Data System (ADS)

Wu, Hongyan; Li, Xianghong; Zhang, Junying

2018-06-01

This paper presents a new sampling method for fibre length measurement. This new method can meet the three features of an effective sampling method, also it can produce the beard with two symmetrical ends which can be scanned from the holding line to get two full fibrograms for each sample. The methodology was introduced and experiments were performed to investigate effectiveness of the new method. The results show that the new sampling method is an effective sampling method.

Mineralogic correlates of fibrosis in chrysotile miners and millers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Churg, A.; Wright, J.L.; DePaoli, L.

1989-04-01

To determine which mineral parameters relate to the degree of interstitial fibrosis (asbestosis) in the lungs of chrysotile miners and millers, we graded fibrosis histologically and correlated fibrosis grades with fiber concentration and mean size, surface area, and mass, and with total sample fiber length, surface area, and mass in 21 cases. A positive correlation of fibrosis grade with tremolite concentration and a lesser correlation with chrysotile concentration was found for whole lungs, specific sites within lungs, and, for tremolite, single microscopic fields. No correlations were found for measures of chrysotile fiber size, surface area, or mass, but tremolite meanmore » fiber length, aspect ratio, and surface area were, surprisingly, negatively correlated with fibrosis grade. Measures based on total rather than on mean case or site parameters failed to show correlations with fibrosis. We conclude that: (1) degree of pulmonary fibrosis reflects fiber concentration at both a bulk and a microscopic level; (2) mean fiber length and parameters related to mean fiber length also correlate with fibrosis grade, but, contrary to predictions from animal studies, this correlation is negative, suggesting that short fibers may be more important in the genesis of pulmonary fibrosis than is commonly believed; (3) there is no evidence that parameters such as total fiber length, surface area, or mass provide predictors of degree of fibrosis.« less

Standardisation of crown-rump length measurement.

PubMed

Ioannou, C; Sarris, I; Hoch, L; Salomon, L J; Papageorghiou, A T

2013-09-01

Correct estimation of gestational age is essential for any study of ultrasound biometry and for everyday clinical practice. However, inconsistency in pregnancy dating may occur through differences in measurement methods or errors during measurement. In the INTERGROWTH-21(st) Project, pregnancies are dated by the last menstrual period, provided that it is certain and associated with a regular menstrual cycle, and the gestational age by dates concurs with a first-trimester ultrasound crown-rump length (CRL) estimation. Hence, there was a need to standardise CRL measurement methodology across the study sites in this international, multicentre project to avoid systematic differences in dating. To achieve uniformity we undertook the following steps: the ultrasound technique was standardised by disseminating an illustrated, operating manual describing CRL plane landmarks and calliper application, and posters describing the correct acquisition technique were disseminated for quick reference. To ensure that all ultrasonographers understood the methodology, they forwarded a log-book to the INTERGROWTH-21(st) Ultrasound Coordinating Unit, containing the answers to a written test on the manual material and five images of a correctly acquired CRL. Interpretation of CRL was also standardised by ensuring that the same CRL regression formula was used across all study sites. These methods should minimise potential systematic errors in dating associated with pooling data from different health institutions, and represent a model for standardising CRL measurement in future studies. © 2013 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2013 RCOG.

Measurement of molecular length of self-assembled monolayer probed by localized surface plasmon resonance

NASA Astrophysics Data System (ADS)

Ito, Juri; Kajikawa, Kotaro

2016-02-01

We propose a method to measure the variation of the molecular length of self-assembled monolayers (SAMs) when it is exposed to solutions at different pH conditions. The surface immobilized gold nanospheres (SIGNs) shows strong absorption peak at the wavelengths of 600-800 nm when p-polarized light is illuminated. The peak wavelength depends on the length of the gap distance between the SIGNs and the substrate. The gap is supported by the SAM molecules. According to the analytical calculation based on multiple expansion, the relation between the peak wavelength of the SIGN structures and the gap distance is calculated, to evaluate the molecular length of the SAM through the optical absorption spectroscopy for the SIGN structures. The molecular length of the SIGN structure was measured in air, water, acidic, and basic solutions. It was found that the molecular lengths are longer in acidic solutions.

Correlation of pressure measurements with angiographic characteristics predisposing to hemorrhage and steal in cerebral arteriovenous malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norbash, A.M.; Marks, M.P.; Lane, B.

1994-05-01

To determine whether there is a physiologic explanation for the predisposition of patients with certain angiographic characteristics to symptoms of hemorrhage and steal. Superselective transcatheter feeding arterial pressure and mean arterial pressure measurements were obtained before embolotherapy in 32 patients with cerebral arteriovenous malformations. Pressures were correlated with previously described angioarchitectural characteristics predisposing to hemorrhage and steal. These included size of the arteriovenous malformation, feeding artery length, venous drainage pattern, and angiomatous change. The feeding arterial pressure and feeding arterial pressure/mean arterial pressure ratios were significantly decreased in patients with angiomatous change. Feeding arterial pressure and feeding arterial pressure/mean arterialmore » pressure ratios progressively decreased as lesions went from peripheral, to mixed, to central venous drainage. A trend for lower feeding arterial pressure was also demonstrated with greater feeding pedicle length. A statistically significant correlation could not be demonstrated between feeding arterial pressure or feeding arterial pressure/mean arterial pressure ratios and size of the arteriovenous malformation, hemorrhage, or symptoms of steal. Feeding arterial pressure measurements help provide a physiologic basis for the relationship between certain angiographic characteristics and hemorrhage and steal symptoms in patients with arteriovenous malformation. 27 refs., 1 fig.« less

Measurement of the length of pedestrian crossings and detection of traffic lights from image data

NASA Astrophysics Data System (ADS)

Shioyama, Tadayoshi; Wu, Haiyuan; Nakamura, Naoki; Kitawaki, Suguru

2002-09-01

This paper proposes a method for measurement of the length of a pedestrian crossing and for the detection of traffic lights from image data observed with a single camera. The length of a crossing is measured from image data of white lines painted on the road at a crossing by using projective geometry. Furthermore, the state of the traffic lights, green (go signal) or red (stop signal), is detected by extracting candidates for the traffic light region with colour similarity and selecting a true traffic light from them using affine moment invariants. From the experimental results, the length of a crossing is measured with an accuracy such that the maximum relative error of measured length is less than 5% and the rms error is 0.38 m. A traffic light is efficiently detected by selecting a true traffic light region with an affine moment invariant.

The Importance of Parameter Variances, Correlations Lengths, and Cross-Correlations in Reactive Transport Models: Key Considerations for Assessing the Need for Microscale Information (Invited)

NASA Astrophysics Data System (ADS)

Reimus, P. W.

2010-12-01

A process-oriented modeling approach is implemented to examine the importance of parameter variances, correlation lengths, and especially cross-correlations in contaminant transport predictions over large scales. It is shown that the most important consideration is the correlation between flow rates and retardation processes (e.g., sorption, matrix diffusion) in the system. If flow rates are negatively correlated with retardation factors in systems containing multiple flow pathways, then characterizing these negative correlation(s) may have more impact on reactive transport modeling than microscale information. Such negative correlations are expected in porous-media systems where permeability is negatively correlated with clay content and rock alteration (which are usually associated with increased sorption). Likewise, negative correlations are expected in fractured rocks where permeability is positively correlated with fracture apertures, which in turn are negatively correlated with sorption and matrix diffusion. Parameter variances and correlation lengths are also shown to have important effects on reactive transport predictions, but they are less important than parameter cross-correlations. Microscale information pertaining to contaminant transport has become more readily available as characterization methods and spectroscopic instrumentation have achieved lower detection limits, greater resolution, and better precision. Obtaining detailed mechanistic insights into contaminant-rock-water interactions is becoming a routine practice in characterizing reactive transport processes in groundwater systems (almost necessary for high-profile publications). Unfortunately, a quantitative link between microscale information and flow and transport parameter distributions or cross-correlations has not yet been established. One reason for this is that quantitative microscale information is difficult to obtain in complex, heterogeneous systems, so simple systems that lack the

Measurement of Two-Plasmon-Decay Dependence on Plasma Density Scale Length

NASA Astrophysics Data System (ADS)

Haberberger, D.

2013-10-01

An accurate understanding of the plasma scale-length (Lq) conditions near quarter-critical density is important in quantifying the hot electrons generated by the two-plasmon-decay (TPD) instability in long-scale-length plasmas. A novel target platform was developed to vary the density scale length and an innovative diagnostic was implemented to measure the density profiles above 1021 cm-3 where TPD is expected to have the largest growth. A series of experiments was performed using the four UV (351-nm) beams on OMEGA EP that varied the Lq by changing the radius of curvature of the target while maintaining a constant Iq/Tq. The fraction of laser energy converted to hot electrons (fhot) was observed to increase rapidly from 0.005% to 1% by increasing the plasma scale length from 130 μm to 300 μm, corresponding to target diameters of 0.4 mm to 8 mm. A new diagnostic was developed based on refractometry using angular spectral filters to overcome the large phase accumulation in standard interferometric techniques. The angular filter refractometer measures the refraction angles of a 10-ps, 263-nm probe laser after propagating through the plasma. An angular spectral filter is used in the Fourier plane of the probe beam, where the refractive angles of the rays are mapped to space. The edges of the filter are present in the image plane and represent contours of constant refraction angle. These contours are used to infer the phase of the probe beam, which are used to calculate the plasma density profile. In long-scale-length plasmas, the diagnostic currently measures plasma densities from ~1019 cm-3 to ~2 × 1021 cm-3. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944. In collaboration with D. H. Edgell, S. X. Hu, S. Ivancic, R. Boni, C. Dorrer, and D. H. Froula (Laboratory for Laser Energetics, U. of Rochester).

Is socioeconomic status associated with biological aging as measured by telomere length?

PubMed

Robertson, Tony; Batty, G David; Der, Geoff; Fenton, Candida; Shiels, Paul G; Benzeval, Michaela

2013-01-01

It has been hypothesized that one way in which lower socioeconomic status (SES) affects health is by increasing the rate of biological aging. A widely used marker of biological aging is telomere length. Telomeres are structures at the ends of chromosomes that erode with increasing cell proliferation and genetic damage. We aimed to identify, through systematic review and meta-analysis, whether lower SES (greater deprivation) is associated with shorter telomeres. Thirty-one articles, including 29 study populations, were identified. We conducted 3 meta-analyses to compare the telomere lengths of persons of high and low SES with regard to contemporaneous SES (12 study populations from 10 individual articles), education (15 study populations from 14 articles), and childhood SES (2 study populations from 2 articles). For education, there was a significant difference in telomere length between persons of high and low SES in a random-effects model (standardized mean difference (SMD) = 0.060, 95% confidence interval (CI): 0.002, 0.118; P = 0.042), although a range of sensitivity analyses weakened this association. There was no evidence for an association between telomere length and contemporaneous SES (SMD = 0.104, 95% CI: -0.027, 0.236; P = 0.119) or childhood SES (SMD = -0.037, 95% CI: -0.143, 0.069; P = 0.491). These results suggest weak evidence for an association between SES (as measured by education) and biological aging (as measured by telomere length), although there was a lack of consistent findings across the SES measures investigated here. © The Author 2012. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

The Correlation between Angle Kappa and Ocular Biometry in Koreans

PubMed Central

Choi, Se Rang

2013-01-01

Purpose To investigate normative angle kappa data and to examine whether correlations exist between angle kappa and ocular biometric measurements (e.g., refractive error, axial length) and demographic features in Koreans. Methods Data from 436 eyes (213 males and 223 females) were analyzed in this study. The angle kappa was measured using Orbscan II. We used ocular biometric measurements, including refractive spherical equivalent, interpupillary distance and axial length, to investigate the correlations between angle kappa and ocular biometry. The IOL Master ver. 5.02 was used to obtain axial length. Results The mean patient age was 57.5 ± 12.0 years in males and 59.4 ± 12.4 years in females (p = 0.11). Angle kappa averaged 4.70 ± 2.70 degrees in men and 4.89 ± 2.14 degrees in women (p = 0.48). Axial length and spherical equivalent were correlated with angle kappa (r = -0.342 and r = 0.197, respectively). The correlation between axial length and spherical equivalent had a negative correlation (r = -0.540, p < 0.001). Conclusions Angle kappa increased with spherical equivalent and age. Thus, careful manipulation should be considered in older and hyperopic patients when planning refractive or strabismus surgery. PMID:24311927

Composition dependence of charge and magnetic length scales in mixed valence manganite thin films

PubMed Central

Singh, Surendra; Freeland, J. W.; Fitzsimmons, M. R.; Jeen, H.; Biswas, A.

2016-01-01

Mixed-valence manganese oxides present striking properties like the colossal magnetoresistance, metal-insulator transition (MIT) that may result from coexistence of ferromagnetic, metallic and insulating phases. Percolation of such phase coexistence in the vicinity of MIT leads to first-order transition in these manganites. However the length scales over which the electronic and magnetic phases are separated across MIT which appears compelling for bulk systems has been elusive in (La1−yPry)1−xCaxMnO3 films. Here we show the in-plane length scale over which charge and magnetism are correlated in (La0.4Pr0.6)1−xCaxMnO3 films with x = 0.33 and 0.375, across the MIT temperature. We combine electrical transport (resistance) measurements, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), and specular/off-specular x-ray resonant magnetic scattering (XRMS) measurements as a function of temperature to elucidate relationships between electronic, magnetic and morphological structure of the thin films. Using off-specular XRMS we obtained the charge-charge and charge-magnetic correlation length of these LPCMO films across the MIT. We observed different charge-magnetic correlation length for two films which increases below the MIT. The different correlation length shown by two films may be responsible for different macroscopic (transport and magnetic) properties. PMID:27461993

Utilization of coincidence criteria in absolute length measurements by optical interferometry in vacuum and air

NASA Astrophysics Data System (ADS)

Schödel, R.

2015-08-01

Traceability of length measurements to the international system of units (SI) can be realized by using optical interferometry making use of well-known frequencies of monochromatic light sources mentioned in the Mise en Pratique for the realization of the metre. At some national metrology institutes, such as Physikalisch-Technische Bundesanstalt (PTB) in Germany, the absolute length of prismatic bodies (e.g. gauge blocks) is realized by so-called gauge-block interference comparators. At PTB, a number of such imaging phase-stepping interference comparators exist, including specialized vacuum interference comparators, each equipped with three highly stabilized laser light sources. The length of a material measure is expressed as a multiple of each wavelength. The large number of integer interference orders can be extracted by the method of exact fractions in which the coincidence of the lengths resulting from the different wavelengths is utilized as a criterion. The unambiguous extraction of the integer interference orders is an essential prerequisite for correct length measurements. This paper critically discusses coincidence criteria and their validity for three modes of absolute length measurements: 1) measurements under vacuum in which the wavelengths can be identified with the vacuum wavelengths, 2) measurements under air in which the air refractive index is obtained from environmental parameters using an empirical equation, and 3) measurements under air in which the air refractive index is obtained interferometrically by utilizing a vacuum cell placed along the measurement pathway. For case 3), which corresponds to PTB’s Kösters-Comparator for long gauge blocks, the unambiguous determination of integer interference orders related to the air refractive index could be improved by about a factor of ten when an ‘overall dispersion value,’ suggested in this paper, is used as coincidence criterion.

Measurement of turbulent electron temperature fluctuations on the ASDEX Upgrade tokamak using correlated electron cyclotron emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freethy, S. J., E-mail: simon.freethy@ipp.mpg.de; Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; Conway, G. D.

2016-11-15

Turbulent temperature fluctuations are measured on the ASDEX Upgrade tokamak using pairs of closely spaced, narrow-band heterodyne radiometer channels and a standard correlation technique. The pre-detection spacing and bandwidth of the radiometer channel pairs is chosen such that they are physically separated less than a turbulent correlation length, but do not overlap. The radiometer has 4 fixed filter frequency channels and two tunable filter channels for added flexibility in the measurement position. Relative temperature fluctuation amplitudes are observed in a helium plasma to be δT/T = (0.76 ± 0.02)%, (0.67 ± 0.02)%, and (0.59 ± 0.03)% at normalised toroidal fluxmore » radius of ρ{sub tor} = 0.82, 0.75, and 0.68, respectively.« less

Integration of length and curvature in haptic perception.

PubMed

Panday, Virjanand; Tiest, Wouter M Bergmann; Kappers, Astrid M L

2014-01-24

We investigated if and how length and curvature information are integrated when an object is explored in one hand. Subjects were asked to explore four types of objects between thumb and index finger. Objects differed in either length, curvature, both length and curvature correlated as in a circle, or anti-correlated. We found that when both length and curvature are present, performance is significantly better than when only one of the two cues is available. Therefore, we conclude that there is integration of length and curvature. Moreover, if the two cues are correlated in a circular cross-section instead of in an anti-correlated way, performance is better than predicted by a combination of two independent cues. We conclude that integration of curvature and length is highly efficient when the cues in the object are combined as in a circle, which is the most common combination of curvature and length in daily life.

Improved cutback method measuring beat-length for high-birefringence optical fiber by fitting data of photoelectric signal

NASA Astrophysics Data System (ADS)

Shi, Zhi-Dong; Lin, Jian-Qiang; Bao, Huan-Huan; Liu, Shu; Xiang, Xue-Nong

2008-03-01

A photoelectric measurement system for measuring the beat length of birefringence fiber is set up including a set of rotating-wave-plate polarimeter using single photodiode. And two improved cutback methods suitable for measuring beat-length within millimeter range of high birefringence fiber are proposed through data processing technique. The cut length needs not to be restricted shorter than one centimeter so that the auto-cleaving machine is freely used, and no need to carefully operate the manually cleaving blade with low efficiency and poor success. The first method adopts the parameter-fitting to a saw-tooth function of tried beat length by the criterion of minimum square deviations, without special limitation on the cut length. The second method adopts linear-fitting in the divided length ranges, only restrict condition is the increment between different cut lengths less than one beat-length. For a section of holey high-birefringence fiber, we do experiments respectively by the two methods. The detecting error of beat-length is discussed and the advantage is compared.

Correlation Between Transperineal 3-Dimensional Ultrasound Measurements of Levator Hiatus and Female Sexual Function.

PubMed

Aydin, Serdar; Bakar, Rabia Zehra; Arioğlu Aydin, Çağri; Ateş, Seda

The aim of this study is to investigate the association of sexual functions with levator hiatus biometry measurements and levator ani muscle defect. In 62 heterosexual, sexually active premenopausal women without pelvic floor disorders or urinary incontinence, 3-dimensional transperineal ultrasound imaging was used. Two 3-dimensional volumes were recorded, one at rest and one on Valsalva maneuver. Levator biometry measurements and levator defect were evaluated in an axial plane. Sexual function was assessed by a validated questionnaire, Female Sexual Function Index (FSFI). The primary outcome measure was correlation of sexual functions with the levator hiatus area, transverse and anteroposterior diameters, levator ani muscle thickness, vaginal length, and changes in measurements with Valsalva and levator defect. Forty-two women (67.7%) had low total FSFI scores (<26.55). Levator defect rates were similar in female sexual dysfunction (7/42, 16.7%) and women without female sexual dysfunction (5/20, 25%). The FSFI was negatively and weakly correlated with Δhiatal anteroposterior diameter (r = -0.33, P < 0.009) in the study population. There was a weak and inverse correlation between Δhiatal anteroposterior diameter and arousal (r = -0.35, P < 0.002), desire (r = -0.38, P < 0.001), and orgasm (r = -0.33, P < 0.007). Pain and lubrication did not correlate with any measurement. Hiatal area and diameters at rest are not related to sexual functions. Changes in anteroposterior diameter of the levator hiatus during Valsalva, which may be a sign of pelvic floor laxity or levator muscle weakness, are weakly associated with sexual functions, particularly desire, arousal, and orgasm domains.

Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

USGS Publications Warehouse

Bonilla, Manuel G.; Mark, Robert K.; Lienkaemper, James J.

1984-01-01

In order to refine correlations of surface-wave magnitude, fault rupture length at the ground surface, and fault displacement at the surface by including the uncertainties in these variables, the existing data were critically reviewed and a new data base was compiled. Earthquake magnitudes were redetermined as necessary to make them as consistent as possible with the Gutenberg methods and results, which make up much of the data base. Measurement errors were estimated for the three variables for 58 moderate to large shallow-focus earthquakes. Regression analyses were then made utilizing the estimated measurement errors.The regression analysis demonstrates that the relations among the variables magnitude, length, and displacement are stochastic in nature. The stochastic variance, introduced in part by incomplete surface expression of seismogenic faulting, variation in shear modulus, and regional factors, dominates the estimated measurement errors. Thus, it is appropriate to use ordinary least squares for the regression models, rather than regression models based upon an underlying deterministic relation in which the variance results primarily from measurement errors.Significant differences exist in correlations of certain combinations of length, displacement, and magnitude when events are grouped by fault type or by region, including attenuation regions delineated by Evernden and others.Estimates of the magnitude and the standard deviation of the magnitude of a prehistoric or future earthquake associated with a fault can be made by correlating Ms with the logarithms of rupture length, fault displacement, or the product of length and displacement.Fault rupture area could be reliably estimated for about 20 of the events in the data set. Regression of Ms on rupture area did not result in a marked improvement over regressions that did not involve rupture area. Because no subduction-zone earthquakes are included in this study, the reported results do not apply to such

Is short stature associated with short cervical length?

PubMed

Gagel, Caroline K; Rafael, Timothy J; Berghella, Vincenzo

2010-10-01

We sought to estimate if there is a correlation between maternal height and cervical length in women at high risk for preterm birth. We studied a retrospective cohort of women with singleton gestation and risk factors for preterm birth. Maternal height was categorized as short (<157.5 cm) or not short stature (≥157.5 cm). Cervical length at 14 to 24 weeks was evaluated. Primary outcomes were incidence of initial cervical length <30 mm and incidence of shortest cervical length <25 mm. Four hundred sixteen women met the inclusion criteria. Twenty-two (22.6%) of the short women and 79 (24.5%) of the nonshort women had an initial cervical length <30 mm ( P = 0.81). Twenty-two (23.7%) of the short women and 104 (32.2%) of the nonshort women had a cervical length <25 mm for shortest cervical length measurement ( P = 0.15). In women with singleton gestation and risk factors for preterm birth, no statistically significant relationship exists between maternal height and initial or shortest cervical length. © Thieme Medical Publishers.

Relationship between Achilles tendon length and running performance in well-trained male endurance runners.

PubMed

Ueno, Hiromasa; Suga, Tadashi; Takao, Kenji; Tanaka, Takahiro; Misaki, Jun; Miyake, Yuto; Nagano, Akinori; Isaka, Tadao

2018-02-01

This study aimed to determine the relationship between Achilles tendon (AT) length and running performance, including running economy, in well-trained endurance runners. We also examined the reasonable portion of the AT related to running performance among AT lengths measured in three different portions. The AT lengths at three portions and cross-sectional area (CSA) of 30 endurance runners were measured using magnetic resonance imaging. Each AT length was calculated as the distance from the calcaneal tuberosity to the muscle-tendon junction of the soleus, gastrocnemius medialis (GM AT ), and gastrocnemius lateralis, respectively. These AT lengths were normalized with shank length. The AT CSA was calculated as the average of 10, 20, and 30 mm above the distal insertion of the AT and normalized with body mass. Running economy was evaluated by measuring energy cost during three 4-minutes submaximal treadmill running trials at 14, 16, and 18 km/h, respectively. Among three AT lengths, only a GM AT correlated significantly with personal best 5000-m race time (r=-.376, P=.046). Furthermore, GM AT correlated significantly with energy cost during submaximal treadmill running trials at 14 km/h and 18 km/h (r=-.446 and -.429, respectively, P<.05 for both), and a trend toward such significance was observed at 16 km/h (r=-.360, P=.050). In contrast, there was no correlation between AT CSA and running performance. These findings suggest that longer AT, especially GM AT , may be advantageous to achieve superior running performance, with better running economy, in endurance runners. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Stern potential and Debye length measurements in dilute ionic solutions with electrostatic force microscopy.

PubMed

Kumar, Bharat; Crittenden, Scott R

2013-11-01

We demonstrate the ability to measure Stern potential and Debye length in dilute ionic solution with atomic force microscopy. We develop an analytic expression for the second harmonic force component of the capacitive force in an ionic solution from the linearized Poisson-Boltzmann equation. This allows us to calibrate the AFM tip potential and, further, obtain the Stern potential of sample surfaces. In addition, the measured capacitive force is independent of van der Waals and double layer forces, thus providing a more accurate measure of Debye length.

Bunch length measurement at the Fermilab A0 photoinjector using a Martin-Puplett interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurman-Keup, Randy; Fliller, Raymond Patrick; Kazakevich, Grigory

2008-05-01

We present preliminary measurements of the electron bunch lengths at the Fermilab A0 Photoinjector using a Martin-Puplett interferometer on loan from DESY. The photoinjector provides a relatively wide range of bunch lengths through laser pulse width adjustment and compression of the beam using a magnetic chicane. We present comparisons of data with simulations that account for diffraction distortions in the signal and discuss future plans for improving the measurement.

Sonographic measurement of abdominal esophageal length as a diagnostic tool in gastroesophageal reflux disease in infants.

PubMed

Dehdashti, Hamid; Dehdashtian, Masoud; Rahim, Fakher; Payvasteh, Mehrdad

2011-01-01

This study was conducted to provide sonographic measurements of the abdominal esophagus length in neonates and infants with and without gastroesophageal reflux disease (GERD) and to investigate its diagnostic value. GERD severity was also evaluated and correlated with esophageal length. It is a prospective case-control study. This prospective case-control study comprised 235 neonates and infants (120 without reflux and 115 with reflux). There were 40 children without reflux in each of three age categories: less than 1 month, 1-6 months, and 6-12 months. Of the children with reflux, 40 were less than 1 month old; 37, 1-6 months; and 38, 6-12 months. The abdominal esophagus was measured from its entrance into the diaphragm to the base of gastric folds in fed infants. GERD was sonographically diagnosed and confirmed by a barium meal. The number of refluxes during a 10-min period were recorded. Neonates and infants with reflux had a significantly shorter abdominal esophagus than subjects without reflux: the mean difference in neonates, 4.65 mm; 1-6 months, 4.57 mm; 6-12 months, 3.61 mm. Children with severe reflux had a shorter esophagus compared with those with mild and moderate reflux only in the neonate group. Therefore, thinking of GERD and carefully looking for its symptoms is necessary to avoid unnecessary utilization of healthcare resources in children with severe reflux.

Usefulness of telomere length in DNA from human teeth for age estimation.

PubMed

Márquez-Ruiz, Ana Belén; González-Herrera, Lucas; Valenzuela, Aurora

2018-03-01

Age estimation is widely used to identify individuals in forensic medicine. However, the accuracy of the most commonly used procedures is markedly reduced in adulthood, and these methods cannot be applied in practice when morphological information is limited. Molecular methods for age estimation have been extensively developed in the last few years. The fact that telomeres shorten at each round of cell division has led to the hypothesis that telomere length can be used as a tool to predict age. The present study thus aimed to assess the correlation between telomere length measured in dental DNA and age, and the effect of sex and tooth type on telomere length; a further aim was to propose a statistical regression model to estimate the biological age based on telomere length. DNA was extracted from 91 tooth samples belonging to 77 individuals of both sexes and 15 to 85 years old and was used to determine telomere length by quantitative real-time PCR. Our results suggested that telomere length was not affected by sex and was greater in molar teeth. We found a significant correlation between age and telomere length measured in DNA from teeth. However, the equation proposed to predict age was not accurate enough for forensic age estimation on its own. Age estimation based on telomere length in DNA from tooth samples may be useful as a complementary method which provides an approximate estimate of age, especially when human skeletal remains are the only forensic sample available.

Dual tunneling-unit scanning tunneling microscope for length measurement based on crystalline lattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, H.; Higuchi, T.; Nishioki, N.

1997-01-01

A dual tunneling-unit scanning tunneling microscope (DTU STM) was developed for nm order length measurement with wide scan range. The crystalline lattice of highly oriented pyrolitic graphite (HOPG) was used as reference scale. A reference unit was set up on top of a test unit. The reference sample holder and the probe tip of test unit were attached to one single XY scanner on either surface, while the test sample holder was open. This enables simultaneous acquisition of wide images of HOPG and test sample. The length in test sample image was measured by counting the number of HOPG lattices.more » An inchworm actuator and an impact drive mechanism were introduced to roughly position probe tips. The XY scanner was designed to be elastic to eliminate image distortion. Some comparison experiments using two HOPG chips were carried out in air. The DTU STM is confirmed to be a stable and more powerful device for length measurement which has nanometer accuracy when covering a wide scan range up to several micrometers, and is capable of measuring comparatively large and heavy samples. {copyright} {ital 1997 American Vacuum Society.}« less

Arm span and ulnar length are reliable and accurate estimates of recumbent length and height in a multiethnic population of infants and children under 6 years of age.

PubMed

Forman, Michele R; Zhu, Yeyi; Hernandez, Ladia M; Himes, John H; Dong, Yongquan; Danish, Robert K; James, Kyla E; Caulfield, Laura E; Kerver, Jean M; Arab, Lenore; Voss, Paula; Hale, Daniel E; Kanafani, Nadim; Hirschfeld, Steven

2014-09-01

Surrogate measures are needed when recumbent length or height is unobtainable or unreliable. Arm span has been used as a surrogate but is not feasible in children with shoulder or arm contractures. Ulnar length is not usually impaired by joint deformities, yet its utility as a surrogate has not been adequately studied. In this cross-sectional study, we aimed to examine the accuracy and reliability of ulnar length measured by different tools as a surrogate measure of recumbent length and height. Anthropometrics [recumbent length, height, arm span, and ulnar length by caliper (ULC), ruler (ULR), and grid (ULG)] were measured in 1479 healthy infants and children aged <6 y across 8 study centers in the United States. Multivariate mixed-effects linear regression models for recumbent length and height were developed by using ulnar length and arm span as surrogate measures. The agreement between the measured length or height and the predicted values by ULC, ULR, ULG, and arm span were examined by Bland-Altman plots. All 3 measures of ulnar length and arm span were highly correlated with length and height. The degree of precision of prediction equations for length by ULC, ULR, and ULG (R(2) = 0.95, 0.95, and 0.92, respectively) was comparable with that by arm span (R(2) = 0.97) using age, sex, and ethnicity as covariates; however, height prediction by ULC (R(2) = 0.87), ULR (R(2) = 0.85), and ULG (R(2) = 0.88) was less comparable with arm span (R(2) = 0.94). Our study demonstrates that arm span and ULC, ULR, or ULG can serve as accurate and reliable surrogate measures of recumbent length and height in healthy children; however, ULC, ULR, and ULG tend to slightly overestimate length and height in young infants and children. Further testing of ulnar length as a surrogate is warranted in physically impaired or nonambulatory children. © 2014 American Society for Nutrition.

Tendon length and joint flexibility are related to running economy.

PubMed

Hunter, Gary R; Katsoulis, Konstantina; McCarthy, John P; Ogard, William K; Bamman, Marcas M; Wood, David S; Den Hollander, Jan A; Blaudeau, Tamilane E; Newcomer, Bradley R

2011-08-01

The purpose of study was to determine whether quadriceps/patella and Achilles tendon length and flexibility of the knee extensors and plantar flexors are related to walking and running economy. Twenty-one male distance runners were subjects. Quadriceps/patella and Achilles tendon length were measured by magnetic resonance imaging; body composition was measured DXA; oxygen uptake at rest while seated, walking (3 mph), and running (6 and 7 mph) were measured by indirect calorimetry; knee and ankle joint flexibility were measured by goniometry; and leg lengths were measured by anthropometry while seated. Correlations were used to identify relationships between variables of interest. Net VO2 (exercise VO2 - rest VO2) for walking (NVOWK) and running at 6 and 7 mph (NVO6 and NVO7, respectively) was significantly related to Achilles tendon length (r varying from -0.40 to -0.51, P all < 0.04). Achilles tendon cross section was not related to walking or running economy. Quadriceps/patella tendon length was significantly related to NVO7 (r = -0.43, P = 0.03) and approached significance for NVO6 (r = -0.36, P = 0.06). Flexibility of the plantar flexors was related to NVO7 (+0.38, P = 0.05). Multiple regression showed that Achilles tendon length was independently related to NVO6 and NVO7 (partial r varying from -0.53 to -0.64, all P < 0.02) independent of lower leg length, upper leg length, quadriceps/patella tendon length, knee extension flexibility, or plantarflexion flexibility. These data support the premise that longer lower limb tendons (especially Achilles tendon) and less flexible lower limb joints are associated with improved running economy.

Measuring correlations in non-separable vector beams using projective measurements

NASA Astrophysics Data System (ADS)

Subramanian, Keerthan; Viswanathan, Nirmal K.

2017-09-01

Doubts regarding the completeness of quantum mechanics as raised by Einstein, Podolsky and Rosen(EPR) have predominantly been resolved by resorting to a measurement of correlations between entangled photons which clearly demonstrate violation of Bell's inequality. This article is an attempt to reconcile incompatibility of hidden variable theories with reality by demonstrating experimentally a violation of Bell's inequality in locally correlated systems whose two degrees of freedom, the spin and orbital angular momentum, are maximally correlated. To this end we propose and demonstrate a linear, achromatic modified Sagnac interferometer to project orbital angular momentum states which we combine with spin projections to measure correlations.

Internal fracture heterogeneity in discrete fracture network modelling: Effect of correlation length and textures with connected and disconnected permeability field

NASA Astrophysics Data System (ADS)

Frampton, A.; Hyman, J.; Zou, L.

2017-12-01

Analysing flow and transport in sparsely fractured media is important for understanding how crystalline bedrock environments function as barriers to transport of contaminants, with important applications towards subsurface repositories for storage of spent nuclear fuel. Crystalline bedrocks are particularly favourable due to their geological stability, low advective flow and strong hydrogeochemical retention properties, which can delay transport of radionuclides, allowing decay to limit release to the biosphere. There are however many challenges involved in quantifying and modelling subsurface flow and transport in fractured media, largely due to geological complexity and heterogeneity, where the interplay between advective and dispersive flow strongly impacts both inert and reactive transport. A key to modelling transport in a Lagrangian framework involves quantifying pathway travel times and the hydrodynamic control of retention, and both these quantities strongly depend on heterogeneity of the fracture network at different scales. In this contribution, we present recent analysis of flow and transport considering fracture networks with single-fracture heterogeneity described by different multivariate normal distributions. A coherent triad of fields with identical correlation length and variance are created but which greatly differ in structure, corresponding to textures with well-connected low, medium and high permeability structures. Through numerical modelling of multiple scales in a stochastic setting we quantify the relative impact of texture type and correlation length against network topological measures, and identify key thresholds for cases where flow dispersion is controlled by single-fracture heterogeneity versus network-scale heterogeneity. This is achieved by using a recently developed novel numerical discrete fracture network model. Furthermore, we highlight enhanced flow channelling for cases where correlation structure continues across

Bunch Length Measurements Using CTR at the AWA with Comparison to Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neveu, N.; Spentzouris, L.; Halavanau, A.

In this paper we present electron bunch length measurements at the Argonne Wakefield Accelerator (AWA) photoinjector facility. The AWA accelerator has a large dynamic charge density range, with electron beam charge varying between 0.1 nC - 100 nC, and laser spot size diameter at the cathode between 0.1 mm - 18 mm. The bunch length measurements were taken at different charge densities using a metallic screen and a Michelson interferometer to perform autocorrelation scans of the corresponding coherent transition radiation (CTR). A liquid helium-cooled 4K bolometer was used to register the interferometer signal. The experimental results are compared with OPAL-Tmore » numerical simulations.« less

A Correlation Between Length of Strong-Shear Neutral Lines and Total X-Ray Brightness in Active Regions

NASA Technical Reports Server (NTRS)

Falconer, D. A.

1997-01-01

From a sample of 7 MSFC vector magnetograms,of active regions and 17 Yohkoh SXT soft X-ray images of these active regions, we have found that the total x-ray brightness of an entire active region is correlated with the total length of neutral lines on which the magnetic field is both strong (less than 250 G) and strongly sheared (shear angle greater than 75 deg) in the same active region. This correlation, if not fortuitous, is additional evidence of the importance of strong-shear strong-field neutral lines to strong heating in active regions.

Electrical Conductivity through a Single Atomic Step Measured with the Proximity-Induced Superconducting Pair Correlation

DOE PAGES

Kim, Howon; Lin, Shi -Zeng; Graf, Matthias J.; ...

2016-09-08

Local disordered nanostructures in an atomically thick metallic layer on a semiconducting substrate play significant and decisive roles in transport properties of two-dimensional (2D) conductive systems. We measured the electrical conductivity through a step of monoatomic height in a truly microscopic manner by using as a signal the superconducting pair correlation induced by the proximity effect. The transport property across a step of a one-monolayer Pb surface metallic phase, formed on a Si(111) substrate, was evaluated by inducing the pair correlation around the local defect and measuring its response, i.e., the reduced density of states at the Fermi energy usingmore » scanning tunneling microscopy. We found that the step resistance has a significant contribution to the total resistance on a nominally flat surface. Our study also revealed that steps in the 2D metallic layer terminate the propagation of the pair correlation. Furthermore, superconductivity is enhanced between the first surface step and the superconductor–normal-metal interface by reflectionless tunneling when the step is located within a coherence length.« less

Electrical Conductivity through a Single Atomic Step Measured with the Proximity-Induced Superconducting Pair Correlation.

PubMed

Kim, Howon; Lin, Shi-Zeng; Graf, Matthias J; Miyata, Yoshinori; Nagai, Yuki; Kato, Takeo; Hasegawa, Yukio

2016-09-09

Local disordered nanostructures in an atomically thick metallic layer on a semiconducting substrate play significant and decisive roles in transport properties of two-dimensional (2D) conductive systems. We measured the electrical conductivity through a step of monoatomic height in a truly microscopic manner by using as a signal the superconducting pair correlation induced by the proximity effect. The transport property across a step of a one-monolayer Pb surface metallic phase, formed on a Si(111) substrate, was evaluated by inducing the pair correlation around the local defect and measuring its response, i.e., the reduced density of states at the Fermi energy using scanning tunneling microscopy. We found that the step resistance has a significant contribution to the total resistance on a nominally flat surface. Our study also revealed that steps in the 2D metallic layer terminate the propagation of the pair correlation. Superconductivity is enhanced between the first surface step and the superconductor-normal-metal interface by reflectionless tunneling when the step is located within a coherence length.

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2013 CFR

2013-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2014 CFR

2014-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2012 CFR

2012-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

The Length of a Pestle: A Class Exercise in Measurement and Statistical Analysis.

ERIC Educational Resources Information Center

O'Reilly, James E.

1986-01-01

Outlines the simple exercise of measuring the length of an object as a concrete paradigm of the entire process of making chemical measurements and treating the resulting data. Discusses the procedure, significant figures, measurement error, spurious data, rejection of results, precision and accuracy, and student responses. (TW)

Influence of eye rotation on peripheral eye length measurement obtained with a partial coherence interferometry instrument.

PubMed

Verkicharla, Pavan K; Suheimat, Marwan; Mallen, Edward A H; Atchison, David A

2014-01-01

The eye rotation approach for measuring peripheral eye length leads to concern about whether the rotation influences results, such as through pressure exerted by eyelids or extra-ocular muscles. This study investigated whether this approach is valid. Peripheral eye lengths were measured with a Lenstar LS 900 biometer for eye rotation and no-eye rotation conditions (head rotation for horizontal meridian and instrument rotation for vertical meridian). Measurements were made for 23 healthy young adults along the horizontal visual field (± 30°) and, for a subset of eight participants along the vertical visual field (± 25°). To investigate the influence of the duration of eye rotation, for six participants measurements were made at 0, 60, 120, 180 and 210 s after eye rotation to ± 30° along horizontal and vertical visual fields. Peripheral eye lengths were not significantly different for the conditions along the vertical meridian (F1,7 = 0.16, p = 0.71). The peripheral eye lengths for the conditions were significantly different along the horizontal meridian (F1,22 = 4.85, p = 0.04), although not at individual positions (p ≥ 0.10) and were not important. There were no apparent differences between the emmetropic and myopic groups. There was no significant change in eye length at any position after maintaining position for 210 s. Eye rotation and no-eye rotation conditions were similar for measuring peripheral eye lengths along horizontal and vertical visual field meridians at ± 30° and ± 25°, respectively. Either condition can be used to estimate retinal shape from peripheral eye lengths. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

Salivary progesterone and cervical length measurement as predictors of spontaneous preterm birth.

PubMed

Maged, Ahmed M; Mohesen, Mohamed; Elhalwagy, Ahmed; Abdelhafiz, Ali

2015-07-01

To evaluate the efficacy of salivary progesterone, cervical length measurement in predicting preterm birth (PTB). Prospective observational study included 240 pregnant women with gestational age (GA) 26-34 weeks classified into two equal groups; group one are high risk for PTB (those with symptoms of uterine contractions or history of one or more spontaneous preterm delivery or second trimester abortion) and group 2 are controls. There was a highly significant difference between the two study groups regarding GA at delivery (31.3 ± 3.75 in high risk versus 38.5 ± 1.3 in control), cervical length measured by transvaginal ultrasound (24.7 ± 8.6 in high risk versus 40.1 ± 4.67 in control) and salivary progesterone level (728.9 ± 222.3 in high risk versus 1099.9 ± 189.4 in control; p < 0.001). There was a statistically significant difference between levels of salivary progesterone at different GA among the high risk group (p value 0.035) but not in low risk group (p value 0.492). CL measurement showed a sensitivity of 71.5% with 100% specificity, 100% PPV, 69.97% NPV and accuracy of 83%, while salivary progesterone showed a sensitivity of 84% with 90% specificity, 89.8% PPV, 85.9% NPV and accuracy of 92.2%. The measurement of both salivary progesterone and cervical length are good predictors for development of PTB.

Precision measurement of the n-3He incoherent scattering length using neutron interferometry.

PubMed

Huber, M G; Arif, M; Black, T C; Chen, W C; Gentile, T R; Hussey, D S; Pushin, D A; Wietfeldt, F E; Yang, L

2009-05-22

We report the first measurement of the low-energy neutron-(3)He incoherent scattering length using neutron interferometry: b_{i};{'} = (-2.512 +/- 0.012 stat +/- 0.014 syst) fm. This is in good agreement with a recent calculation using the AV18 + 3N potential. The neutron-(3)He scattering lengths are important for testing and developing nuclear potential models that include three-nucleon forces, effective field theories for few-body nuclear systems, and neutron scattering measurements of quantum excitations in liquid helium. This work demonstrates the first use of a polarized nuclear target in a neutron interferometer.

Preparation and measurement of FBG-based length, temperature, and vibration sensors

NASA Astrophysics Data System (ADS)

Mikel, Bretislav; Helan, Radek; Buchta, Zdenek; Jelinek, Michal; Cip, Ondrej

2016-12-01

We present system of structure health measurement by optical fiber sensors based on fiber Bragg gratings. Our system is focused to additionally install to existing buildings. We prepared first set-up of the system to monitoring of the nuclear power plant containment shape deformation. The presented system can measure up to several tens of sensors simultaneously. Each sensor contains optical fiber grating to measurement of change of length and the other independed fiber grating to monitor the temperature and the other ineligible effects.

Allometric relationships among body mass, MUZZLE-tail length, and tibia length during the growth of Wistar rats.

PubMed

Santiago, Hildemberg Agostinho Rocha de; De Pierro, Lucas Rodolfo; Reis, Rafael Menezes; Caluz, Antônio Gabriel Ricardo Engracia; Ribeiro, Victor Barbosa; Volpon, José Batista

2015-11-01

To investigate allometric relationships among body mass (BM), muzzle-tail length (MTL), and tibia length (TL) in Wistar rats and establish their growth rate change parameters. Eighteen male and 18 female Wistar rats were studied from the 3rd to the 21st week of age. BM, MTL, and TL were measured daily, and relative growth was compared using allometry. A positive correlation between BM and MTL (p<0.05) and BM and TL (p<0.05) was observed. Males and females showed comparable curves; however, females had turning points at a younger age. The allometric relationship between BM and MTL presented a regular increase until reaching a mass of 351 g (males) and 405 g (females). BM and TL showed an initial increase until 185 g (males) and 182 g (females), and then reached a plateau that finished at 412 g (males) and 334 g (females), to display another increase. The allometric relationship of body mass with animal length and tibia length was comparable for male and female rats, with female rats maturing earlier. Animal longitudinal growth occurred in a single stage. In contrast, tibia length depicted two stages of accelerated growth with an intermediate period of deceleration.

Roughness Length as a Measure of the Effects of a Vegetative Windbreak

NASA Astrophysics Data System (ADS)

Kenny, W.; Maurer, K.; Bohrer, G.

2012-12-01

Vegetative windbreaks are often used as barriers to block the dispersion of particulate matter, particularly around agricultural facilities. Windbreaks and narrow forest strips alter the wind pattern and affect dispersion of particles and aerosols that are carried across. Our observations during two field campaigns, conducted near animal feeding lots where large flumes of dust are advected across edge-of-field windbreaks, suggest that sensible heat flux greatly affects the interaction between the flow and the windbreak. We used measurements at multiple heights upwind and downwind of the windbreak to calculate the background roughness length and the effective roughness length of the windbreak. While the flow is not fully adjusted at the wake of the windbreak, we use measurements at different times of the day as a sensitivity analysis to the strength of the buoyancy term within the theoretical surface similarity equation that includes the effects of the wind break. Clearly, calculated roughness length downwind of the windbreak is much greater than upwind of the windbreak, but as SHF increases, the difference in roughness length across the windbreak decreases indicating a decrease in the overall effect of the windbreak on flow. Our findings indicate that as SHF increases, windbreaks may not be able to play much of a role in affecting the dispersion of particulate matter, as the overall effects of windbreaks diminish.

Direct measurement of the plasma screening length and surface potential near the lunar terminator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, J.

1977-05-01

Direct measurement of the lunar dayside surface potential and screening length has been made by the suprathermal ion detector experiment (Side) near the terminator. In a region 20degree--30degree from the terminator at the Apollo 14 and 15 sites the surface potential is found to be approximately 50 V negative, and the screening length to be about 1 km. This value of the screening length is more than 2 orders of magnitude greater than the solar wind 'Debye' length. The strong negative surface potential in this region may be due to enhanced temperature and density of the solar wind plasma.

Direct measurement of the plasma screening length and surface potential near the lunar terminator

NASA Technical Reports Server (NTRS)

Benson, J.

1977-01-01

Direct measurement of the lunar dayside surface potential and screening length has been made by the suprathermal ion detector experiment (Side) near the terminator. In a region 20-30 deg from the terminator at the Apollo 14 and 15 sites the surface potential is found to be approximately 50 V negative, and the screening length to be about 1 km. This value of the screening length is more than 2 orders of magnitude greater than the solar wind 'Debye' length. The strong negative surface potential in this region may be due to enhanced temperature and density of the solar wind plasma.

[Comparative study of cone-beam CT and spiral CT in measuring the length of styloid process].

PubMed

Song, Y S; Liu, L F

2018-06-19

Objective: To compare the difference of measuring the length of styloid process between spiral CT with high resolution and cone-beam CT(CBCT). Methods: Five specimens (including 5 pairs of styloid processes) were selected randomly from the Anatomy Laboratory of Otolaryngology Department, all the specimens underwent spiral CT with high resolution and cone-beam CT retrospectively.With the original DICOM data, the styloid processes were shown in one plate by multiple plate reconstruction technique, and later the length of styloid processes of each specimen were measured separately by software NNT Viewer (to CBCT) or Osrix (to spiral CT with high resolution). Results: The length of styloid processes measured by CBCT and spiral CT was (26.8±5.5) mm and (27.1±5.4) mm respectively, and there was no statistical difference between the two groups. Conclusion: In respect of measuring the length of styloid process, the CBCT has the same value in clinical practice comparing to spiral CT with high resolution.

Correlation lengths in hydrodynamic models of active nematics.

PubMed

Hemingway, Ewan J; Mishra, Prashant; Marchetti, M Cristina; Fielding, Suzanne M

2016-09-28

We examine the scaling with activity of the emergent length scales that control the nonequilibrium dynamics of an active nematic liquid crystal, using two popular hydrodynamic models that have been employed in previous studies. In both models we find that the chaotic spatio-temporal dynamics in the regime of fully developed active turbulence is controlled by a single active scale determined by the balance of active and elastic stresses, regardless of whether the active stress is extensile or contractile in nature. The observed scaling of the kinetic energy and enstrophy with activity is consistent with our single-length scale argument and simple dimensional analysis. Our results provide a unified understanding of apparent discrepancies in the previous literature and demonstrate that the essential physics is robust to the choice of model.

Pairing versus quarteting coherence length

NASA Astrophysics Data System (ADS)

Delion, D. S.; Baran, V. V.

2015-02-01

We systematically analyze the coherence length in even-even nuclei. The pairing coherence length in the spin-singlet channel for the effective density-dependent delta (DDD) and Gaussian interaction is estimated. We consider in our calculations bound states as well as narrow resonances. It turns out that the pairing gaps given by the DDD interaction are similar to those of the Gaussian potential if one renormalizes the radial width to the nuclear radius. The correlations induced by the pairing interaction have, in all considered cases, a long-range character inside the nucleus and a decrease towards the surface. The mean coherence length is larger than the geometrical radius for light nuclei and approaches this value for heavy nuclei. The effect of the temperature and states in the continuum is investigated. Strong shell effects are put in evidence, especially for protons. We generalize this concept to quartets by considering similar relations, but between proton and neutron pairs. The quartet coherence length has a similar shape, but with larger values on the nuclear surface. We provide evidence of the important role of proton-neutron correlations by estimating the so-called alpha coherence length, which takes into account the overlap with the proton-neutron part of the α -particle wave function. It turns out that it does not depend on the nuclear size and has a value comparable to the free α -particle radius. We have shown that pairing correlations are mainly concentrated inside the nucleus, while quarteting correlations are connected to the nuclear surface.

[Measurement of screw length through drilling technique in osteosynthesis of the proximal humerus fractures].

PubMed

Avcı, Cem Coşkun; Gülabi, Deniz; Sağlam, Necdet; Kurtulmuş, Tuhan; Saka, Gürsel

2013-01-01

This study aims to investigate the efficacy of screw length measurement through drilling technique on the reduction of intraarticular screw penetration and fluoroscopy time in osteosynthesis of proximal humerus fractures. Between January 2008 and June 2012, 98 patients (34 males, 64 females; mean age 64.4 years; range 35 to 81 years) who underwent osteosynthesis using locking anatomical proximal humerus plates (PHILOS) in our clinic with the diagnosis of Neer type 2, 3 or 4 were included. Two different surgical techniques were used to measure proximal screw length in the plate and patients were divided into two groups based on the technique used. In group 1, screw length was determined by a 3 mm blunt tipped Kirschner wire without fluoroscopic control. In group 2, bilateral fluoroscopic images for each screw at least were obtained. Intraarticular screw penetration was detected in five patients (10.6%) in group 1, and in 19 patients (37.3%) in group 2. The mean fluoroscopic imaging time was 10.6 seconds in group 1 and 24.8 seconds in group 2, indicating a statistically significant difference. Screw length measurement through the drilling technique significantly reduces the intraarticular screw penetration and fluoroscopy time in osteosynthesis of proximal humerus fractures using PHILOS plates.

Entanglement measures based on observable correlations

NASA Astrophysics Data System (ADS)

Luo, Shunlong

2008-06-01

By regarding quantum states as communication channels and using observable correlations quantitatively expressed by mutual information, we introduce a hierarchy of entanglement measures that includes the entanglement of formation as a particular instance. We compare the maximal and minimal measures and indicate the conceptual advantages of the minimal measure over the entanglement of formation. We reveal a curious feature of the entanglement of formation by showing that it can exceed the quantum mutual information, which is usually regarded as a theoretical measure of total correlations. This places the entanglement of formation in a broader scenario, highlights its peculiarity in relation to pure-state ensembles, and introduces a competing definition with intrinsic informational significance.

Image scale measurement with correlation filters in a volume holographic optical correlator

NASA Astrophysics Data System (ADS)

Zheng, Tianxiang; Cao, Liangcai; He, Qingsheng; Jin, Guofan

2013-08-01

A search engine containing various target images or different part of a large scene area is of great use for many applications, including object detection, biometric recognition, and image registration. The input image captured in realtime is compared with all the template images in the search engine. A volume holographic correlator is one type of these search engines. It performs thousands of comparisons among the images at a super high speed, with the correlation task accomplishing mainly in optics. However, the inputted target image always contains scale variation to the filtering template images. At the time, the correlation values cannot properly reflect the similarity of the images. It is essential to estimate and eliminate the scale variation of the inputted target image. There are three domains for performing the scale measurement, as spatial, spectral and time domains. Most methods dealing with the scale factor are based on the spatial or the spectral domains. In this paper, a method with the time domain is proposed to measure the scale factor of the input image. It is called a time-sequential scaled method. The method utilizes the relationship between the scale variation and the correlation value of two images. It sends a few artificially scaled input images to compare with the template images. The correlation value increases and decreases with the increasing of the scale factor at the intervals of 0.8~1 and 1~1.2, respectively. The original scale of the input image can be measured by estimating the largest correlation value through correlating the artificially scaled input image with the template images. The measurement range for the scale can be 0.8~4.8. Scale factor beyond 1.2 is measured by scaling the input image at the factor of 1/2, 1/3 and 1/4, correlating the artificially scaled input image with the template images, and estimating the new corresponding scale factor inside 0.8~1.2.

Understanding the amplitudes of noise correlation measurements

USGS Publications Warehouse

Tsai, Victor C.

2011-01-01

Cross correlation of ambient seismic noise is known to result in time series from which station-station travel-time measurements can be made. Part of the reason that these cross-correlation travel-time measurements are reliable is that there exists a theoretical framework that quantifies how these travel times depend on the features of the ambient noise. However, corresponding theoretical results do not currently exist to describe how the amplitudes of the cross correlation depend on such features. For example, currently it is not possible to take a given distribution of noise sources and calculate the cross correlation amplitudes one would expect from such a distribution. Here, we provide a ray-theoretical framework for calculating cross correlations. This framework differs from previous work in that it explicitly accounts for attenuation as well as the spatial distribution of sources and therefore can address the issue of quantifying amplitudes in noise correlation measurements. After introducing the general framework, we apply it to two specific problems. First, we show that we can quantify the amplitudes of coherency measurements, and find that the decay of coherency with station-station spacing depends crucially on the distribution of noise sources. We suggest that researchers interested in performing attenuation measurements from noise coherency should first determine how the dominant sources of noise are distributed. Second, we show that we can quantify the signal-to-noise ratio of noise correlations more precisely than previous work, and that these signal-to-noise ratios can be estimated for given situations prior to the deployment of seismometers. It is expected that there are applications of the theoretical framework beyond the two specific cases considered, but these applications await future work.

Normative data for penile length in Turkish newborns.

PubMed

Kutlu, Alev Oğuz

2010-01-01

Local normative data for penile size will aid physicians in clinical practice. There are no studies on stretched penile length (SPL) in newborn Turkish boys. To establish normative data for SPL of newborn Turkish boys and compare these with data from different countries. 514 newborn Turkish boys, who were not small for gestational age (SGA) or premature, were included in this cross-sectional study. SPLs of the newborns were measured by the same investigator. The correlations between SPL and gestational age, weight, length, and head circumference were evaluated. The 3(rd) percentile value for SPL was found as 3.00 cm in these Turkish newborns. Positive correlations were shown between SPL and height (r=0.240, p<0.001), weight (r=0.251, p<0.001), and head circumference (r=0.235, p<0.001). Multiple linear regression analysis showed that SPL positively correlated with height and head circumference (p=0.021 and p= 0.042, respectively). This is the largest study on SPL in newborns from our country. This normative data can be used in clinical practice for defining micropenis.

Gibbs measures with memory of length 2 on an arbitrary-order Cayley tree

NASA Astrophysics Data System (ADS)

Akın, Hasan

In this paper, we consider the Ising-Vanniminus model on an arbitrary-order Cayley tree. We generalize the results conjectured by Akın [Chinese J. Phys. 54(4), 635-649 (2016) and Int. J. Mod. Phys. B 31(13), 1750093 (2017)] for an arbitrary-order Cayley tree. We establish the existence and a full classification of translation-invariant Gibbs measures (TIGMs) with a memory of length 2 associated with the model on arbitrary-order Cayley tree. We construct the recurrence equations corresponding to the generalized ANNNI model. We satisfy the Kolmogorov consistency condition. We propose a rigorous measure-theoretical approach to investigate the Gibbs measures with a memory of length 2 for the model. We explain if the number of branches of the tree does not change the number of Gibbs measures. Also, we try to determine when the phase transition does occur.

Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

USGS Publications Warehouse

Bonilla, M.G.; Mark, R.K.; Lienkaemper, J.J.

1984-01-01

In order to refine correlations of surface-wave magnitude, fault rupture length at the ground surface, and fault displacement at the surface by including the uncertainties in these variables, the existing data were critically reviewed and a new data base was compiled. Earthquake magnitudes were redetermined as necessary to make them as consistent as possible with the Gutenberg methods and results, which necessarily make up much of the data base. Measurement errors were estimated for the three variables for 58 moderate to large shallow-focus earthquakes. Regression analyses were then made utilizing the estimated measurement errors. The regression analysis demonstrates that the relations among the variables magnitude, length, and displacement are stochastic in nature. The stochastic variance, introduced in part by incomplete surface expression of seismogenic faulting, variation in shear modulus, and regional factors, dominates the estimated measurement errors. Thus, it is appropriate to use ordinary least squares for the regression models, rather than regression models based upon an underlying deterministic relation with the variance resulting from measurement errors. Significant differences exist in correlations of certain combinations of length, displacement, and magnitude when events are qrouped by fault type or by region, including attenuation regions delineated by Evernden and others. Subdivision of the data results in too few data for some fault types and regions, and for these only regressions using all of the data as a group are reported. Estimates of the magnitude and the standard deviation of the magnitude of a prehistoric or future earthquake associated with a fault can be made by correlating M with the logarithms of rupture length, fault displacement, or the product of length and displacement. Fault rupture area could be reliably estimated for about 20 of the events in the data set. Regression of MS on rupture area did not result in a marked improvement

Tyre contact length on dry and wet road surfaces measured by three-axial accelerometer

NASA Astrophysics Data System (ADS)

Matilainen, Mika; Tuononen, Ari

2015-02-01

We determined the tyre contact length on dry and wet roads by measuring the accelerations of the inner liner with a three-axial accelerometer. The influence of the tyre pressure, driving velocity, and tread depth on the contact length was studied in both types of road surface conditions. On dry asphalt the contact length was almost constant, regardless of the driving velocity. On wet asphalt the presence of water could be detected even at low driving velocities (e.g. 20 km/h for a worn tyre) as the contact length began to decrease from that found in the dry asphalt situation. In addition to improving the performance of active safety systems and driver warning systems, the contact length information could be beneficial for classifying and studying the aquaplaning behaviour of tyres.

Episiotomy increases perineal laceration length in primiparous women.

PubMed

Nager, C W; Helliwell, J P

2001-08-01

The aim of this study was to determine the clinical factors that contribute to posterior perineal laceration length. A prospective observational study was performed in 80 consenting, mostly primiparous women with term pregnancies. Posterior perineal lacerations were measured immediately after delivery. Numerous maternal, fetal, and operator variables were evaluated against laceration length and degree of tear. Univariate and multivariate regression analyses were performed to evaluate laceration length and parametric clinical variables. Nonparametric clinical variables were evaluated against laceration length by the Mann-Whitney U test. A multivariate stepwise linear regression equation revealed that episiotomy adds nearly 3 cm to perineal lacerations. Tear length was highly associated with the degree of tear (R = 0.86, R(2) = 0.73) and the risk of recognized anal sphincter disruption. None of 35 patients without an episiotomy had a recognized anal sphincter disruption, but 6 of 27 patients with an episiotomy did (P <.001). Body mass index was the only maternal or fetal variable that showed even a slight correlation with laceration length (R = 0.30, P =.04). Episiotomy is the overriding determinant of perineal laceration length and recognized anal sphincter disruption.

Head circumference, leg length and its association with dementia among older adult population in Singapore.

PubMed

Chang, Sherilyn; Ong, Hui Lin; Abdin, Edimansyah; Vaingankar, Janhavi Ajit; Jeyagurunathan, Anitha; Shafie, Saleha; Mahendran, Rathi; Subramaniam, Mythily; Chong, Siow Ann

2017-12-01

Head circumference and leg length serve as reliable proxy indicators of early-life environment. Research studies have shown that these anthropometric measurements are associated with cognitive impairment and dementia among older adults. The aim of the present study was to assess the associations between dementia with head circumference and leg length among the older adult population in Singapore. This study also aimed to examine the sociodemographic correlates of these anthropometric measurements. Data were collected from 2565 older adults aged 60 years and above, in a population study on the Well-being of the Singapore Elderly. Head circumference and leg length measurements were obtained, and sociodemographic information was recorded. Dementia diagnosis was made using the 10/66 dementia algorithm. Anthropometric measurements were first stratified into quarters, and then logistic regression analysis was used to examine factors associated with head circumference and leg length, as well as to examine the association between dementia with these measurements. Sociodemographic correlates of head circumference and leg length include age, gender, ethnicity and education level. Smaller head circumference was independently associated with higher odds of 10/66 dementia (OR = 2.173-2.709). When the regression analysis was stratified by gender, the association was found only in the male sample. Leg length was not significantly associated with dementia after controlling for sociodemographic variables. Smaller head circumference is independently associated with dementia among older adults in Singapore. Findings from this study suggest that risk factors for dementia begin their influence in early life. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

The golden ratio of nasal width to nasal bone length.

PubMed

Goynumer, G; Yayla, M; Durukan, B; Wetherilt, L

2011-01-01

To calculate the ratio of fetal nasal width over nasal bone length at 14-39 weeks' gestation in Caucasian women. Fetal nasal bone length and nasal width at 14-39 weeks' gestation were measured in 532 normal fetuses. The mean and standard deviations of fetal nasal bone length, nasal width and their ratio to one another were calculated in normal fetuses according to the gestational age to establish normal values. A positive and linear correlation was detected between the nasal bone length and the gestational week, as between the nasal width and the gestational week. No linear growth pattern was found between the gestational week and the ratio of nasal width to nasal bone length, nearly equal to phi, throughout gestation. The ratio of nasal width to nasal bone length, approximately equal to phi, can be calculated at 14-38 weeks' gestation. This might be useful in evaluating fetal abnormalities.

Relationship between the surrogate anthropometric measures, foot length and chest circumference and birth weight among newborns of Sarlahi, Nepal.

PubMed

Mullany, L C; Darmstadt, G L; Khatry, S K; Leclerq, S C; Tielsch, J M

2007-01-01

Classification of infants into low birth weight (LBW, <2500 g) or very low birth weight (VLBW, <2000 g) categories is a crucial step in targeting interventions to high-risk infants. To compare the validity of chest circumference and foot length as surrogate anthropometric measures for the identification of LBW and VLBW infants. Newborn infants (n=1640) born between March and June 2004 in 30 Village Development Committees of Sarlahi district, Nepal. Chest circumference, foot length and weight (SECA 727, precise to 2 g) of newborns were measured within 72 h after birth. The sensitivity, specificity and predictive values for a range of cutoff points of the anthropometric measures were estimated using the digital scale measurements as the gold standard. Among LBW infants (469/1640, 28.6%), chest circumference measures <30.3 cm were 91% sensitive and 83% specific. Similar levels of sensitivity for foot length were achieved only with considerable loss of specificity (<45%). Foot length measurements <6.9 cm were 88% sensitive and 86% specific for the identification of VLBW infants. Chest circumference was superior to foot length in classification of infants into birth weight categories. For the identification of VLBW infants, foot length performed well, and may be preferable to chest circumference, as the former measure does not require removal of infant swaddling clothes. In the absence of more precise direct measures of birth weight, chest circumference is recommended over foot length for the identification of LBW infants.

Interpretation of scanning electron microscope measurements of minority carrier diffusion lengths in semiconductors

NASA Technical Reports Server (NTRS)

Flat, A.; Milnes, A. G.

1978-01-01

In scanning electron microscope (SEM) injection measurements of minority carrier diffusion lengths some uncertainties of interpretation exist when the response current is nonlinear with distance. This is significant in epitaxial layers where the layer thickness is not large in relation to the diffusion length, and where there are large surface recombination velocities on the incident and contact surfaces. An image method of analysis is presented for such specimens. A method of using the results to correct the observed response in a simple convenient way is presented. The technique is illustrated with reference to measurements in epitaxial layers of GaAs. Average beam penetration depth may also be estimated from the curve shape.

An Anthropometric Study of Cranio-Facial Measurements and Their Correlation with Vertical Dimension of Occlusion among Saudi Arabian Subpopulations.

PubMed

Majeed, Muhammed Irfan; Haralur, Satheesh B; Khan, Muhammed Farhan; Al Ahmari, Maram Awdah; Al Shahrani, Nourah Falah; Shaik, Sharaz

2018-04-15

Determining and restoring physiological vertical dimension of occlusion (VDO) is the critical step during complete mouth rehabilitation. The improper VDO compromises the aesthetics, phonetics and functional efficiency of the prosthesis. Various methods are suggested to determine the accurate VDO, including the facial measurements in the clinical situations with no pre-extraction records. The generalisation of correlation between the facial measurements to VDO is criticised due to gender dimorphism and racial differences. Hence, it is prudent to verify the hypothesis of facial proportion and correlation of lower third of the face to remaining craniofacial measurements in different ethnic groups. The objective of the study was to evaluate the correlation of craniofacial measurements and OVD in the Saudi-Arabian ethnic group. Total of 228 participants from Saudi-Arabian Ethnic group were randomly recruited in this cross-sectional study. Fifteen craniofacial measurements were recorded with modified digital Vernier callipers, and OVD was recorded at centric occlusion. The obtained data were analysed by using the Spearman's correlation and linear regression analysis. The Mean OVD in male participants was higher (69.25 ± 5.54) in comparison to female participants (57.41 ± 5.32). The craniofacial measurement of Exocanthion-right labial commissure and the Mesial wall of the right external auditory canal-orbitale lateral had a strong positive correlation with VDO. The strong correlation was recorded with a trichion-upper border of right eyebrow line and trichion-Nasion only in males. Meanwhile, the length of an auricle recorded the positive correlation in female participants. Being simple and non-invasive technique, craniofacial measurements and linear equations could be routinely utilised to determine VDO.

A new Ultra Precision Interferometer for absolute length measurements down to cryogenic temperatures

NASA Astrophysics Data System (ADS)

Schödel, R.; Walkov, A.; Zenker, M.; Bartl, G.; Meeß, R.; Hagedorn, D.; Gaiser, C.; Thummes, G.; Heltzel, S.

2012-09-01

A new Ultra Precision Interferometer (UPI) was built at Physikalisch-Technische Bundesanstalt. As its precursor, the precision interferometer, it was designed for highly precise absolute length measurements of prismatic bodies, e.g. gauge blocks, under well-defined temperature conditions and pressure, making use of phase stepping imaging interferometry. The UPI enables a number of enhanced features, e.g. it is designed for a much better lateral resolution and better temperature stability. In addition to the original concept, the UPI is equipped with an external measurement pathway (EMP) in which a prismatic body can be placed alternatively. The temperature of the EMP can be controlled in a much wider range compared to the temperature of the interferometer's main chamber. An appropriate cryostat system, a precision temperature measurement system and improved imaging interferometry were established to permit absolute length measurements down to cryogenic temperature, demonstrated for the first time ever. Results of such measurements are important for studying thermal expansion of materials from room temperature towards less than 10 K.

Correlation of root dentin thickness and length of roots in mesial roots of mandibular molars.

PubMed

Dwivedi, Shweta; Dwivedi, Chandra Dhar; Mittal, Neelam

2014-09-01

The purpose of this study was to analyze the relation of tooth length and distal wall thickness of mesial roots in mandibular molars at different locations (ie, 2 mm below the furcation and at the junction between the middle and apical third). Forty-five mandibular first molars were taken, and the length of each tooth was measured. Then, specimens were divided into three groups according to their length: group I-long (24.2 mm ± 1.8), group II-medium (21 mm ± 1.5) and group III-short (16.8 mm ± 1.8). mesial root of each marked at two levels - at 2 mm below the furcation as well as at junction of apical and middle third of roots. The minimum thickness of the distal root dentine associated with the buccal and lingual canals of the mesial roots was measured, The distance between the buccal and lingual canals and the depth of concavity in the distal surface of the mesial roots were also measured. Statistical analysis was performed by using analysis of variance and the Student-Newman-Keuls test. The minimum thickness of the distal wall of the mesiobuccal canal was significantly different (P < .001) between groups 1 (long) and 3 (short). Distal wall thickness of the mesiobuccal root and distal concavity of the mesial root of mandibular first molars were found to be thinner in longer teeth compared with shorter teeth. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Correlation between length and tilt of lipid tails

NASA Astrophysics Data System (ADS)

Kopelevich, Dmitry I.; Nagle, John F.

2015-10-01

It is becoming recognized from simulations, and to a lesser extent from experiment, that the classical Helfrich-Canham membrane continuum mechanics model can be fruitfully enriched by the inclusion of molecular tilt, even in the fluid, chain disordered, biologically relevant phase of lipid bilayers. Enriched continuum theories then add a tilt modulus κθ to accompany the well recognized bending modulus κ. Different enrichment theories largely agree for many properties, but it has been noticed that there is considerable disagreement in one prediction; one theory postulates that the average length of the hydrocarbon chain tails increases strongly with increasing tilt and another predicts no increase. Our analysis of an all-atom simulation favors the latter theory, but it also shows that the overall tail length decreases slightly with increasing tilt. We show that this deviation from continuum theory can be reconciled by consideration of the average shape of the tails, which is a descriptor not obviously includable in continuum theory.

Measurement of the length of pedestrian crossings from image data

NASA Astrophysics Data System (ADS)

Uddin, Mohammad S.; Shioyama, Tadayoshi

2004-10-01

A computer vision based new method for the measurement of the length of pedestrian crossings using a single camera is described. The main objective of this research is to develop a travel aid for the blind people. In a crossing, the usual black road surface is painted with constant width periodic white bands. In Japan, this width is 45 cm. The crossing region as well as its length is detected using this concept. At first, the crossing direction is determined from the power spectrum using fast Fourier transform. The periodic white and black bands are detected using integration along the crossing direction and then differentiation of the integral data perpendicular to crossing. This detection may be erroneous due to adverse effects of the neighboring region of crossing, as the intensity of the whole image is used for bands detection. To remove the neighboring effects, the crossing region is extracted. Then the crossing bands are detected from the image intensity using the crossing region only. Experiment is performed using 32 real road scenes with pedestrian crossing. The rms error is found 2.28 m. The technique determines the crossing length with good accuracy for crossings marked clearly with white paintings as well as fine image resolution.

Cervical Length in Patients at Risk for Placenta Accreta.

PubMed

Rac, Martha W F; McIntire, Donald D; Wells, C Edward; Moschos, Elysia; Twickler, Diane D

2017-07-01

To evaluate cervical length measurements in women with placenta accreta compared to women with a nonadherent low-lying placenta or placenta previa and evaluate this relationship in terms of vaginal bleeding, preterm labor, and preterm birth. We conducted a retrospective cohort study between 1997 and 2011 of gravidas with more than 1 prior cesarean delivery who had a transvaginal ultrasound examination between 24 and 34 weeks for a low-lying placenta or placenta previa. Cervical length was measured from archived images in accordance with national guidelines by a single investigator, who was blinded to outcomes and ultrasound reports. The diagnosis of placental accreta was based on histologic confirmation. For study purposes, preterm birth was defined as less than 36 weeks, and cervical lengths of 3 cm or less were considered short. Standard statistical analyses were used. A total of 125 patients met inclusion criteria. The cohort was divided into patients with (n = 43 [34%]) and without (n = 82 [66%]) placenta accreta and stratified by gestational age at the ultrasound examinations. Women with placenta accreta had shorter cervical length measurements during their 32- to 34-week ultrasound examinations (mean ± SD, 3.23 ± 0.98 versus 3.95 ± 1.0 cm; P < .01) and were more likely to have a short cervix of 3 cm or less (P = .001). However, these findings did not correlate with the degree of invasion (P = .3), or higher rates of vaginal bleeding and preterm labor (P = .19) resulting in preterm birth before 36 weeks (P = .64). Women with placenta accreta had shorter cervical lengths at 32 to 34 weeks than women with a nonadherent low-lying placenta or placenta previa, but this finding did not correlate with a higher risk of vaginal bleeding or preterm labor resulting in preterm birth before 36 weeks. © 2017 by the American Institute of Ultrasound in Medicine.

Effects of tubing length and coupling method on hearing threshold and real-ear to coupler difference measures.

PubMed

Gustafson, Samantha; Pittman, Andrea; Fanning, Robert

2013-06-01

This tutorial demonstrates the effects of tubing length and coupling type (i.e., foam tip or personal earmold) on hearing threshold and real-ear-to-coupler difference (RECD) measures. Hearing thresholds from 0.25 kHz through 8 kHz are reported at various tubing lengths for 28 normal-hearing adults between the ages of 22 and 31 years. RECD values are reported for 14 of the adults. All measures were made with an insert earphone coupled to a standard foam tip and with an insert earphone coupled to each participant's personal earmold. Threshold and RECD measures obtained with a personal earmold were significantly different from those obtained with a foam tip on repeated measures analyses of variance. One-sample t tests showed these differences to vary systematically with increasing tubing length, with the largest average differences (7-8 dB) occurring at 4 kHz. This systematic examination demonstrates the equal and opposite effects of tubing length on threshold and acoustic measures. Specifically, as tubing length increased, sound pressure level in the ear canal decreased, affecting both hearing thresholds and the real-ear portion of the RECDs. This demonstration shows that when the same coupling method is used to obtain the hearing thresholds and RECD, equal and accurate estimates of real-ear sound pressure level are obtained.

Bilateral step length estimation using a single inertial measurement unit attached to the pelvis

PubMed Central

2012-01-01

Background The estimation of the spatio-temporal gait parameters is of primary importance in both physical activity monitoring and clinical contexts. A method for estimating step length bilaterally, during level walking, using a single inertial measurement unit (IMU) attached to the pelvis is proposed. In contrast to previous studies, based either on a simplified representation of the human gait mechanics or on a general linear regressive model, the proposed method estimates the step length directly from the integration of the acceleration along the direction of progression. Methods The IMU was placed at pelvis level fixed to the subject's belt on the right side. The method was validated using measurements from a stereo-photogrammetric system as a gold standard on nine subjects walking ten laps along a closed loop track of about 25 m, varying their speed. For each loop, only the IMU data recorded in a 4 m long portion of the track included in the calibrated volume of the SP system, were used for the analysis. The method takes advantage of the cyclic nature of gait and it requires an accurate determination of the foot contact instances. A combination of a Kalman filter and of an optimally filtered direct and reverse integration applied to the IMU signals formed a single novel method (Kalman and Optimally filtered Step length Estimation - KOSE method). A correction of the IMU displacement due to the pelvic rotation occurring in gait was implemented to estimate the step length and the traversed distance. Results The step length was estimated for all subjects with less than 3% error. Traversed distance was assessed with less than 2% error. Conclusions The proposed method provided estimates of step length and traversed distance more accurate than any other method applied to measurements obtained from a single IMU that can be found in the literature. In healthy subjects, it is reasonable to expect that, errors in traversed distance estimation during daily monitoring

Measures and models for angular correlation and angular-linear correlation. [correlation of random variables

NASA Technical Reports Server (NTRS)

Johnson, R. A.; Wehrly, T.

1976-01-01

Population models for dependence between two angular measurements and for dependence between an angular and a linear observation are proposed. The method of canonical correlations first leads to new population and sample measures of dependence in this latter situation. An example relating wind direction to the level of a pollutant is given. Next, applied to pairs of angular measurements, the method yields previously proposed sample measures in some special cases and a new sample measure in general.

[Correlations of telomere length changing and pathogeny of keratoconus].

PubMed

Wang, Jiao-jiao; Li, Shao-wei; Wang, Yi-qiang; Wang, Ye; Zhong, Wen-xian; Zang, Xin-jie

2009-08-01

To study telomere length, senescence-associated-beta-galactosidase (SA-beta-galactosidase) and senescence marker protein-30 (SMP-30) in the stromal cells of keratoconus or normal corneas respectively, aiming finding the association of these indexes with the phenotype of keratoconus. Experiment research. 37 keratoconus lesions corneas were removed from 32 keratoconus patients who were operated in Shangdong Eye Institute between January 2006 and December 2006, and 20 normal corneas were collected from eye bank. The keratoconus corneas ages were from 13 to 34 years [mean ages (19 + or - 5) years] and the control group consists of 20 normal corneas donor ages from 9 to 30 years [mean ages (19 + or - 4) years]. And there was no statistical difference of ages between keratoconus and normal corneas. Southern blot method was utilized to detect telomere length of genomic DNA. SA-beta-galactosidase was detected by 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) staining method respectively in keratoconus and normal corneas. Isolated mRNA from keratoconus and normal corneas were reverse-transcribed to cDNA and SMP-30 was detected using PCR with specific primers (sense: 5' ccg tgg atg cct ttg act at 3'; anti-sense: 5' caa ctt cat gc tgct ttg ga 3'). To compare normal corneas and keratoconus corneas by histopathological study. Statistical analysis by t test. The telomere length in stromal cells in keratoconus corneas were from 10.29 to 14.12 kb, mean (11.54 + or - 1.41) kb, while that of normal corneas were from 12.64 to 15.32 kb, mean (13.45 + or - 0.99) kb. The difference of telomere length in stromal cells of keratoconus and normal corneas reached a statistical significant level (t = 4.753, P < 0.05). That means the telomere length of keratoconus stroma was shorter than that of normal corneal stroma. Light microscopy revealed that collagen fibers in keratoconus corneal stroma were arranged in an irregular manner. Cells density in keratoconus stroma appeared lower

Final bubble lengths for aqueous foam coarsened in a horizontal cylinder

NASA Astrophysics Data System (ADS)

Sebag, V.; Roth, A. E.; Durian, D. J.

2011-12-01

We report on length statistics measured for bubbles in the equilibrium bamboo state, achieved by the coarsening of aqueous foam in long cylindrical tubes, such that the soap films are all flat and perpendicular to the axis of the tube. The average bubble length is found to be 0.88 times the tube diameter, independent of variation of the liquid filling fraction by a factor of nearly three. The actual distribution is well-approximated by a shifted Rayleigh form, with a minimum bubble size of 0.28 tube diameters. And, perhaps surprisingly, no correlations are found in the lengths of neighboring bubbles. The observed length distribution agrees with that of Fortes et al. for short bubbles, but not for long bubbles.

Air method measurements of apple vessel length distributions with improved apparatus and theory

Treesearch

Shabtal Cohen; John Bennink; Mel Tyree

2003-01-01

Studies showing that rootstock dwarfing potential is related to plant hydraulic conductance led to the hypothesis that xylem properties are also related. Vessel length distribution and other properties of apple wood from a series of varieties were measured using the 'air method' in order to test this hypothesis. Apparatus was built to measure and monitor...

Universal and idiosyncratic characteristic lengths in bacterial genomes

NASA Astrophysics Data System (ADS)

Junier, Ivan; Frémont, Paul; Rivoire, Olivier

2018-05-01

In condensed matter physics, simplified descriptions are obtained by coarse-graining the features of a system at a certain characteristic length, defined as the typical length beyond which some properties are no longer correlated. From a physics standpoint, in vitro DNA has thus a characteristic length of 300 base pairs (bp), the Kuhn length of the molecule beyond which correlations in its orientations are typically lost. From a biology standpoint, in vivo DNA has a characteristic length of 1000 bp, the typical length of genes. Since bacteria live in very different physico-chemical conditions and since their genomes lack translational invariance, whether larger, universal characteristic lengths exist is a non-trivial question. Here, we examine this problem by leveraging the large number of fully sequenced genomes available in public databases. By analyzing GC content correlations and the evolutionary conservation of gene contexts (synteny) in hundreds of bacterial chromosomes, we conclude that a fundamental characteristic length around 10–20 kb can be defined. This characteristic length reflects elementary structures involved in the coordination of gene expression, which are present all along the genome of nearly all bacteria. Technically, reaching this conclusion required us to implement methods that are insensitive to the presence of large idiosyncratic genomic features, which may co-exist along these fundamental universal structures.

Soybean cell enlargement oscillates with a temperature-compensated period length of ca. 24 min

NASA Technical Reports Server (NTRS)

Morre, D. J.; Pogue, R.; Morre, D. M.

2001-01-01

Rate of enlargement of epidermal cells from soybean, when measured at intervals of 1 min using a light microscope equipped with a video measurement system, oscillated with a period length of about 24 min. This oscillation parallels the 24-min periodicity observed for the oxidation of NADH by the external plasma membrane NADH oxidase. The increase in length was not only non-linear, but intervals of rapid increase in area alternated with intervals of rapid decrease in area. The length of the period was temperature compensated, and was approximately the same when measured at 14, 24 and 34 degrees C even though the rate of cell enlargement varied over this same range of temperatures. These observations represent the first demonstration of an oscillatory growth behavior correlated with a biochemical activity where the period length of both is independent of temperature (temperature compensated) as is the hallmark of clock-related biological phenomena.

Relationship between the surrogate anthropometric measures, foot length and chest circumference and birth weight among newborns of Sarlahi, Nepal

PubMed Central

Mullany, LC; Darmstadt, GL; Khatry, SK; LeClerq, SC; Tielsch, JM

2008-01-01

Background Classification of infants into low birth weight (LBW, <2500 g) or very low birth weight (VLBW, <2000 g) categories is a crucial step in targeting interventions to high-risk infants. Objective To compare the validity of chest circumference and foot length as surrogate anthropometric measures for the identification of LBW and VLBW infants. Subjects and setting Newborn infants (n = 1640) born between March and June 2004 in 30 Village Development Committees of Sarlahi district, Nepal. Design Chest circumference, foot length and weight (SECA 727, precise to 2 g) of newborns were measured within 72 h after birth. The sensitivity, specificity and predictive values for a range of cutoff points of the anthropometric measures were estimated using the digital scale measurements as the gold standard. Results Among LBW infants (469/1640, 28.6%), chest circumference measures <30.3 cm were 91% sensitive and 83% specific. Similar levels of sensitivity for foot length were achieved only with considerable loss of specificity (<45%). Foot length measurements <6.9 cm were 88% sensitive and 86% specific for the identification of VLBW infants. Conclusion Chest circumference was superior to foot length in classification of infants into birth weight categories. For the identification of VLBW infants, foot length performed well, and may be preferable to chest circumference, as the former measure does not require removal of infant swaddling clothes. In the absence of more precise direct measures of birth weight, chest circumference is recommended over foot length for the identification of LBW infants. Sponsorship The National Institute of Child Health and Human Development; the Saving Newborn Lives Initiative, Save the Children – US and the Office of Heath and Nutrition, United States Agency for International Development (see Acknowledgements). PMID:16885929

Persistence length measurements from stochastic single-microtubule trajectories.

PubMed

van den Heuvel, M G L; Bolhuis, S; Dekker, C

2007-10-01

We present a simple method to determine the persistence length of short submicrometer microtubule ends from their stochastic trajectories on kinesin-coated surfaces. The tangent angle of a microtubule trajectory is similar to a random walk, which is solely determined by the stiffness of the leading tip and the velocity of the microtubule. We demonstrate that even a single-microtubule trajectory suffices to obtain a reliable value of the persistence length. We do this by calculating the variance in the tangent trajectory angle of an individual microtubule. By averaging over many individual microtubule trajectories, we find that the persistence length of microtubule tips is 0.24 +/- 0.03 mm.

Limb length inequality: clinical implications for assessment and intervention.

PubMed

Brady, Rebecca J; Dean, John B; Skinner, T Marc; Gross, Michael T

2003-05-01

The purpose of this paper is to review relevant literature concerning limb length inequalities in adults and to make recommendations for assessment and intervention based on the literature and our own clinical experience. Literature searches were conducted in the MEDLINE, PubMed, and CINAHL databases. Limb length inequality and common classification criteria are defined and etiological factors are presented. Common methods of detecting limb length inequality include direct (tape measure methods), indirect (pelvic leveling), and radiological techniques. Interventions include shoe inserts or external shoe lift therapy for mild cases. Surgery may be appropriate in severe cases. Little agreement exists regarding the prevalence of limb length inequality, the degree of limb length inequality that is considered clinically significant, and the reliability and validity of assessment methods. Based on correlational studies, the relationship between limb length inequality and orthopaedic pathologies is questionable. Stronger support for the link between low back pain (LBP) and limb length inequality is provided by intervention studies. Methods involving palpation of pelvic landmarks with block correction have the most support for clinical assessment of limb length inequality. Standing radiographs are suggested when clinical assessment methods are unsatisfactory. Clinicians should exercise caution when undertaking intervention strategies for limb length inequality of less than 5 mm when limb length inequality has been identified with clinical techniques. Recommendations are provided regarding intervention strategies.

Measuring retinal blood flow in rats using Doppler optical coherence tomography without knowing eyeball axial length

PubMed Central

Liu, Wenzhong; Yi, Ji; Chen, Siyu; Jiao, Shuliang; Zhang, Hao F.

2015-01-01

Purpose: Doppler optical coherence tomography (OCT) is widely used for measuring retinal blood flow. Existing Doppler OCT methods require the eyeball axial length, in which empirical values are usually used. However, variations in the axial length can create a bias unaccounted for in the retinal blood flow measurement. The authors plan to develop a Doppler OCT method that can measure the total retinal blood flow rate without requiring the eyeball axial length. Methods: The authors measured the retinal blood flow rate using a dual-ring scanning protocol. The small and large scanning rings entered the eye at different incident angles (small ring: 4°; large ring: 6°), focused on different locations on the retina, and detected the projected velocities/phase shifts along the probing beams. The authors calculated the ratio of the projected velocities between the two rings, and then used this ratio to estimate absolute flow velocity. The authors tested this method in both Intralipid phantoms and in vivo rats. Results: In the Intralipid flow phantom experiments, the preset and measured flow rates were consistent with the coefficient of determination as 0.97. Linear fitting between preset and measured flow rates determined the fitting slope as 1.07 and the intercept as −0.28. In in vivo rat experiments, the measured average total retinal blood flow was 7.02 ± 0.31μl/min among four wild-type rats. The authors’ measured flow rates were consistent with results in the literature. Conclusions: By using a dual-ring scanning protocol with carefully controlled incident angle difference between the two scanning rings in Doppler OCT, the authors demonstrated that it is feasible to measure the absolute retinal blood flow without knowing the eyeball axial length. PMID:26328984

Measuring retinal blood flow in rats using Doppler optical coherence tomography without knowing eyeball axial length.

PubMed

Liu, Wenzhong; Yi, Ji; Chen, Siyu; Jiao, Shuliang; Zhang, Hao F

2015-09-01

Doppler optical coherence tomography (OCT) is widely used for measuring retinal blood flow. Existing Doppler OCT methods require the eyeball axial length, in which empirical values are usually used. However, variations in the axial length can create a bias unaccounted for in the retinal blood flow measurement. The authors plan to develop a Doppler OCT method that can measure the total retinal blood flow rate without requiring the eyeball axial length. The authors measured the retinal blood flow rate using a dual-ring scanning protocol. The small and large scanning rings entered the eye at different incident angles (small ring: 4°; large ring: 6°), focused on different locations on the retina, and detected the projected velocities/phase shifts along the probing beams. The authors calculated the ratio of the projected velocities between the two rings, and then used this ratio to estimate absolute flow velocity. The authors tested this method in both Intralipid phantoms and in vivo rats. In the Intralipid flow phantom experiments, the preset and measured flow rates were consistent with the coefficient of determination as 0.97. Linear fitting between preset and measured flow rates determined the fitting slope as 1.07 and the intercept as -0.28. In in vivo rat experiments, the measured average total retinal blood flow was 7.02 ± 0.31 μl/min among four wild-type rats. The authors' measured flow rates were consistent with results in the literature. By using a dual-ring scanning protocol with carefully controlled incident angle difference between the two scanning rings in Doppler OCT, the authors demonstrated that it is feasible to measure the absolute retinal blood flow without knowing the eyeball axial length.

Measuring retinal blood flow in rats using Doppler optical coherence tomography without knowing eyeball axial length

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Wenzhong; Yi, Ji; Chen, Siyu

Purpose: Doppler optical coherence tomography (OCT) is widely used for measuring retinal blood flow. Existing Doppler OCT methods require the eyeball axial length, in which empirical values are usually used. However, variations in the axial length can create a bias unaccounted for in the retinal blood flow measurement. The authors plan to develop a Doppler OCT method that can measure the total retinal blood flow rate without requiring the eyeball axial length. Methods: The authors measured the retinal blood flow rate using a dual-ring scanning protocol. The small and large scanning rings entered the eye at different incident angles (smallmore » ring: 4°; large ring: 6°), focused on different locations on the retina, and detected the projected velocities/phase shifts along the probing beams. The authors calculated the ratio of the projected velocities between the two rings, and then used this ratio to estimate absolute flow velocity. The authors tested this method in both Intralipid phantoms and in vivo rats. Results: In the Intralipid flow phantom experiments, the preset and measured flow rates were consistent with the coefficient of determination as 0.97. Linear fitting between preset and measured flow rates determined the fitting slope as 1.07 and the intercept as −0.28. In in vivo rat experiments, the measured average total retinal blood flow was 7.02 ± 0.31μl/min among four wild-type rats. The authors’ measured flow rates were consistent with results in the literature. Conclusions: By using a dual-ring scanning protocol with carefully controlled incident angle difference between the two scanning rings in Doppler OCT, the authors demonstrated that it is feasible to measure the absolute retinal blood flow without knowing the eyeball axial length.« less

Calcaneotalar ratio: a new concept in the estimation of the length of the calcaneus.

PubMed

David, Vikram; Stephens, Terry J; Kindl, Radek; Ang, Andy; Tay, Wei-Han; Asaid, Rafik; McCullough, Keith

2015-01-01

Maintaining the calcaneal length after calcaneal fractures is vital to restoring the normal biomechanics of the foot, because it acts as an important lever arm to the plantarflexors of the foot. However, estimation of the length of the calcaneus to be reconstructed in comminuted calcaneal fractures can be difficult. We propose a new method to reliably estimate the calcaneal length radiographically by defining the calcaneotalar length ratio. A total of 100 ankle radiographs with no fracture in the calcaneus or talus taken in skeletally mature patients were reviewed by 6 observers. The anteroposterior lengths of the calcaneus and talus were measured, and the calcaneotalar length ratio was determined. The ratio was then used to estimate the length of the calcaneus. Interobserver reliability was determined using Cronbach's α coefficient and Pearson's correlation coefficient. The mean length of the calcaneus was 75 ± 0.6 mm, and the mean length of the talus was 59 ± 0.5 mm. The calcaneotalar ratio was 1.3. Using this ratio and multiplying it by the talar length, the mean average estimated length of the calcaneus was within 0.7 mm of the known calcaneal length. Cronbach's α coefficient and Pearson's correlation coefficient showed excellent interobserver reliability. The proposed calcaneotalar ratio is a new and reliable method to radiographically estimate the normal length of the calcaneus when reconstructing the calcaneus. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Pendulum test measure correlates with gait parameters in children with cerebral palsy.

PubMed

Lotfian, M; Mirbagheri, M M; Kharazi, M R; Dadashi, F; Nourian, R; Irani, A; Mirbagheri, A

2016-08-01

Individuals with cerebral palsy (CP) usually suffer from different impairments including gait impairment and spasticity. Spastic hypertonia is a defining feature of spasticity and manifests as a mechanical abnormality. The objective of this study was to determine the relationship between spastic hypertonia and gait impairments in spastic children with CP, addressing an important controversial issue. Spastic hypertonia was quantified using the pendulum test. The gait impairments were evaluated using the motion capture system in a gait laboratory. Our results showed significant correlations among gait parameters; i.e. walking speed, step length, and the pendulum test measures. This indicates that neuromuscular abnormalities are associated with spasticity and may contribute to gait impairments. The clinical implication is that the impaired gait in children with CP may be improved with the treatment of neuromuscular abnormalities.

Comparison of stethoscope bell and diaphragm, and of stethoscope tube length, for clinical blood pressure measurement.

PubMed

Liu, Chengyu; Griffiths, Clive; Murray, Alan; Zheng, Dingchang

2016-06-01

This study investigated the effect of stethoscope side and tube length on auscultatory blood pressure (BP) measurement. Thirty-two healthy participants were studied. For each participant, four measurements with different combinations of stethoscope characteristics (bell or diaphragm side, standard or short tube length) were each recorded at two repeat sessions, and eight Korotkoff sound recordings were played twice on separate days to one experienced listener to determine the systolic and diastolic BPs (SBP and DBP). Analysis of variance was carried out to study the measurement repeatability between the two repeat sessions and between the two BP determinations on separate days, as well as the effects of stethoscope side and tube length. There was no significant paired difference between the repeat sessions and between the repeat determinations for both SBP and DBP (all P-values>0.10, except the repeat session for SBP using short tube and diaphragm). The key result was that there was a small but significantly higher DBP on using the bell in comparison with the diaphragm (0.66 mmHg, P=0.007), and a significantly higher SBP on using the short tube in comparison with the standard length (0.77 mmHg, P=0.008). This study shows that stethoscope characteristics have only a small, although statistically significant, influence on clinical BP measurement. Although this helps understand the measurement technique and resolves questions in the published literature, the influence is not clinically significant.

Comparison of stethoscope bell and diaphragm, and of stethoscope tube length, for clinical blood pressure measurement

PubMed Central

Griffiths, Clive; Murray, Alan; Zheng, Dingchang

2016-01-01

Objective This study investigated the effect of stethoscope side and tube length on auscultatory blood pressure (BP) measurement. Methods Thirty-two healthy participants were studied. For each participant, four measurements with different combinations of stethoscope characteristics (bell or diaphragm side, standard or short tube length) were each recorded at two repeat sessions, and eight Korotkoff sound recordings were played twice on separate days to one experienced listener to determine the systolic and diastolic BPs (SBP and DBP). Analysis of variance was carried out to study the measurement repeatability between the two repeat sessions and between the two BP determinations on separate days, as well as the effects of stethoscope side and tube length. Results There was no significant paired difference between the repeat sessions and between the repeat determinations for both SBP and DBP (all P-values>0.10, except the repeat session for SBP using short tube and diaphragm). The key result was that there was a small but significantly higher DBP on using the bell in comparison with the diaphragm (0.66 mmHg, P=0.007), and a significantly higher SBP on using the short tube in comparison with the standard length (0.77 mmHg, P=0.008). Conclusion This study shows that stethoscope characteristics have only a small, although statistically significant, influence on clinical BP measurement. Although this helps understand the measurement technique and resolves questions in the published literature, the influence is not clinically significant. PMID:26741415

Shared genetic determinants of axial length and height in children: the Guangzhou twin eye study.

PubMed

Zhang, Jian; Hur, Yoon-Mi; Huang, Wenyong; Ding, Xiaohu; Feng, Ke; He, Mingguang

2011-01-01

To describe the association between axial length (AL) and height and to estimate the extent to which shared genetic or environmental factors influence this covariance. Study participants were recruited from the Guangzhou Twin Registry. Axial length was measured using partial coherence laser interferometry. Height was measured with the participants standing without shoes. We computed twin pairwise correlations and cross-twin cross-trait correlations between AL and height for monozygotic and dizygotic twins and performed model-fitting analyses using a multivariate Cholesky model. The right eye was arbitrarily selected to represent AL of participants. Five hundred sixty-five twin pairs (359 monozygotic and 206 dizygotic) aged 7 to 15 years were available for analysis. Phenotypic correlation between AL and height was 0.46 but decreased to 0.19 after adjusting for age, sex, and age × sex interaction. Bivariate Cholesky model-fitting analyses revealed that 89% of phenotypic correlation was due to shared genetic factors and 11% was due to shared random environmental factors, which includes measurement error. Covariance of AL and height is largely attributable to shared genes. Given that AL is a key determinant of myopia, further work is needed to confirm gene sharing between myopia and stature.

Length-weight and length-length relationships of common carp (Cyprinus carpio L.) in the middle and southern Iraq provinces

NASA Astrophysics Data System (ADS)

Al-jebory, Taymaa A.; Das, Simon K.; Usup, Gires; Bakar, Y.; Al-saadi, Ali H.

2018-04-01

In this study, length-weight and length-length relationships of common carp (Cyprinus carpio L.) in the middle and southern Iraq provinces were determined. Fish specimens were procured from seven provinces from July to December, 2015. A negative and positive allometric growth pattern was obtained, where the total length (TL) ranged from 25.60 cm to 33.53 cm, and body weight (BW) ranged from 700 g to 1423 g. Meanwhile, the lowest of 1.03 and highest of 3.54 in "b" value was recorded in group F and group C, respectively. Therefore, Fulton condition factor (K) range from 2.57 to 4.94. While, relative condition factor (Kn) was in the ranged of 0.95 to 1.01. A linear relationship between total length (TL) and standard length (SL) among the provinces for fish groups was obtained. The variances in "b" value ranged from 0.10 to 0.93 with correlation coefficient (r2) of 0.02 to 0.97. This research could be used as a guide to study the ecology and biology of common Carp (Cyprinus carpio L.) in the middle and southern Iraq provinces.

Applicability of Mixing Length Theory to a Turbulent Vortex System

NASA Technical Reports Server (NTRS)

Ragsdale, Robert G.

1961-01-01

The ability of mixing length theory to correlate vortex data is evaluated. Expressions are derived for eddy diffusivity by applying the techniques of von Karman and Prandtl which have been established for pipe flow. Total and static pressures were measured from the outer radius to the exhaust-nozzle radius of a vortex generator for a range of mass flows. These data are combined with Navier-Stokes solutions for this region of a compressible vortex to determine turbulent Reynolds numbers. The Reynolds number is related to Prandtl and Karman functions for various assumed boundary conditions, and the experimental data are used to determine the usefulness of these expressions. The following conclusions were reached: (1) Mixing length functions developed by applying von Karman's similarity hypothesis to vortex motion correlate the data better than do Prandtl functions obtained with the assumption that mixing length is proportional to radius. (2) Some of the expressions developed do not adequately represent the experimental data. (3) The data are correlated with acceptable scatter by evaluating the fluid radial inertia at the outer boundary and the shear stress at the inner boundary. The universal constant K was found to be 0.04 to 0.08, rather than the value of 0.4 which is accepted for rectilinear flow. (4) The data are best correlated by a modified Karman expression which includes an effect of radial inertia, as well as shear stress, on eddy diffusivity.

The accuracy of three-dimensional fused deposition modeling (FDM) compared with three-dimensional CT-Scans on the measurement of the mandibular ramus vertical length, gonion-menton length, and gonial angle

NASA Astrophysics Data System (ADS)

Savitri, I. T.; Badri, C.; Sulistyani, L. D.

2017-08-01

Presurgical treatment planning plays an important role in the reconstruction and correction of defects in the craniomaxillofacial region. The advance of solid freeform fabrication techniques has significantly improved the process of preparing a biomodel using computer-aided design and data from medical imaging. Many factors are implicated in the accuracy of the 3D model. To determine the accuracy of three-dimensional fused deposition modeling (FDM) models compared with three-dimensional CT scans in the measurement of the mandibular ramus vertical length, gonion-menton length, and gonial angle. Eight 3D models were produced from the CT scan data (DICOM file) of eight patients at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Indonesia, Cipto Mangunkusumo Hospital. Three measurements were done three times by two examiners. The measurements of the 3D CT scans were made using OsiriX software, while the measurements of the 3D models were made using a digital caliper and goniometry. The measurement results were then compared. There is no significant difference between the measurements of the mandibular ramus vertical length, gonion-menton length, and gonial angle using 3D CT scans and FDM 3D models. FDM 3D models are considered accurate and are acceptable for clinical applications in dental and craniomaxillofacial surgery.

Weighted network analysis of high-frequency cross-correlation measures

NASA Astrophysics Data System (ADS)

Iori, Giulia; Precup, Ovidiu V.

2007-03-01

In this paper we implement a Fourier method to estimate high-frequency correlation matrices from small data sets. The Fourier estimates are shown to be considerably less noisy than the standard Pearson correlation measures and thus capable of detecting subtle changes in correlation matrices with just a month of data. The evolution of correlation at different time scales is analyzed from the full correlation matrix and its minimum spanning tree representation. The analysis is performed by implementing measures from the theory of random weighted networks.

Analytical model and error analysis of arbitrary phasing technique for bunch length measurement

NASA Astrophysics Data System (ADS)

Chen, Qushan; Qin, Bin; Chen, Wei; Fan, Kuanjun; Pei, Yuanji

2018-05-01

An analytical model of an RF phasing method using arbitrary phase scanning for bunch length measurement is reported. We set up a statistical model instead of a linear chirp approximation to analyze the energy modulation process. It is found that, assuming a short bunch (σφ / 2 π → 0) and small relative energy spread (σγ /γr → 0), the energy spread (Y =σγ 2) at the exit of the traveling wave linac has a parabolic relationship with the cosine value of the injection phase (X = cosφr|z=0), i.e., Y = AX2 + BX + C. Analogous to quadrupole strength scanning for emittance measurement, this phase scanning method can be used to obtain the bunch length by measuring the energy spread at different injection phases. The injection phases can be randomly chosen, which is significantly different from the commonly used zero-phasing method. Further, the systematic error of the reported method, such as the influence of the space charge effect, is analyzed. This technique will be especially useful at low energies when the beam quality is dramatically degraded and is hard to measure using the zero-phasing method.

Assessing Children's Understanding of Length Measurement: A Focus on Three Key Concepts

ERIC Educational Resources Information Center

Bush, Heidi

2009-01-01

In this article, the author presents three different tasks that can be used to assess students' understanding of the concept of length. Three important measurement concepts for students to understand are transitive reasoning, use of identical units, and iteration. In any teaching and learning process it is important to acknowledge students'…

Small-Angle Neutron Scattering Studies of Magnetic Correlation Lengths in Nanoparticle Assemblies

NASA Astrophysics Data System (ADS)

Majetich, Sara

2009-03-01

Small-angle neutron scattering (SANS) measurements of ordered arrays of surfactant-coated magnetic nanoparticle reveal characteristic length scales associated with interparticle and intraparticle magnetic ordering. The high degree of uniformity in the monodisperse nanoparticle size and spacing leads to a pronounced diffraction peak and allows for a straightforward determination of these length scales [1]. There are notable differences in these length scales depending on the particle moment, which depends on the material (Fe, Co, Fe3O4) and diameter, and also on whether the metal particle core is surrounded by an oxide shell. For 8.5 nm particles containing an Fe core and thick Fe3O4 shell, evidence of a spin flop phase is seen in the magnetite shell when a field is applied , but not when the shell thickness is ˜0.5 nm [2]. 8.0 nm particles with an e-Co core and 0.75 nm CoO shell show no exchange bias effects while similar particles with a 2 nm thick shell so significant training effects below 90 K. Polarized SANS studied of 7 nm Fe3O4 nanoparticle assemblies show the ability to resolve the magnetization components in 3D. [4pt] [1] M. Sachan, C. Bonnoit, S. A. Majetich, Y. Ijiri, P. O. Mensah-Bonsu, J. A. Borchers, and J. J. Rhyne, Appl. Phys. Lett. 92, 152503 (2008). [0pt] [2] Yumi Ijiri, Christopher V. Kelly, Julie A. Borchers, James J. Rhyne, Dorothy F. Farrell, Sara A. Majetich, Appl. Phys. Lett. 86, 243102-243104 (2005). [0pt] [3] K. L. Krycka, R. Booth, J. A. Borchers, W. C. Chen, C. Conlon, T. Gentile, C. Hogg, Y. Ijiri, M. Laver, B. B. Maranville, S. A. Majetich, J. Rhyne, and S. M. Watson, Physica B (submitted).

Multitime correlators in continuous measurement of qubit observables

NASA Astrophysics Data System (ADS)

Atalaya, Juan; Hacohen-Gourgy, Shay; Martin, Leigh S.; Siddiqi, Irfan; Korotkov, Alexander N.

2018-02-01

We consider multitime correlators for output signals from linear detectors, continuously measuring several qubit observables at the same time. Using the quantum Bayesian formalism, we show that for unital (symmetric) evolution in the absence of phase backaction, an N -time correlator can be expressed as a product of two-time correlators when N is even. For odd N , there is a similar factorization, which also includes a single-time average. Theoretical predictions agree well with experimental results for two detectors, which simultaneously measure noncommuting qubit observables.

Measurement of intact-core length of atomizing liquid jets by image deconvolution

NASA Technical Reports Server (NTRS)

Woodward, Roger; Burch, Robert; Kuo, Kenneth; Cheung, Fan-Bill

1993-01-01

The investigation of liquid jet breakup and spray development is critical to the understanding of combustion phenomena in liquid propellant rocket engines. Much work has been done to characterize low-speed liquid jet breakup and dilute sprays, but atomizing jets and dense sprays have yielded few quantitative measurements due to their high liquid load fractions and hence their optical opacity. Focus was on a characteristic of the primary breakup process of round liquid jets, namely the length of the intact-liquid core. The specific application considered is that of shear-coaxial-type rocket engine injectors in which liquid oxygen is injected through the center post while high velocity gaseous hydrogen is injected through a concentric annulus, providing a shear force to the liquid jet surface. Real-time x ray radiography, capable of imaging through the dense two-phase region surrounding the liquid core, is used to make the measurements. The intact-liquid-core length data were obtained and interpreted using two conceptually different methods to illustrate the effects of chamber pressure, gas-to-liquid momentum ratio, and cavitation.

Measurement of intact-core length of atomizing liquid jets by image deconvolution

NASA Astrophysics Data System (ADS)

Woodward, Roger; Burch, Robert; Kuo, Kenneth; Cheung, Fan-Bill

1993-11-01

The investigation of liquid jet breakup and spray development is critical to the understanding of combustion phenomena in liquid propellant rocket engines. Much work has been done to characterize low-speed liquid jet breakup and dilute sprays, but atomizing jets and dense sprays have yielded few quantitative measurements due to their high liquid load fractions and hence their optical opacity. Focus was on a characteristic of the primary breakup process of round liquid jets, namely the length of the intact-liquid core. The specific application considered is that of shear-coaxial-type rocket engine injectors in which liquid oxygen is injected through the center post while high velocity gaseous hydrogen is injected through a concentric annulus, providing a shear force to the liquid jet surface. Real-time x ray radiography, capable of imaging through the dense two-phase region surrounding the liquid core, is used to make the measurements. The intact-liquid-core length data were obtained and interpreted using two conceptually different methods to illustrate the effects of chamber pressure, gas-to-liquid momentum ratio, and cavitation.

Correlators in simultaneous measurement of non-commuting qubit observables

NASA Astrophysics Data System (ADS)

Atalaya, Juan; Hacohen-Gourgy, Shay; Martin, Leigh S.; Siddiqi, Irfan; Korotkov, Alexander N.

We consider simultaneous continuous measurement of non-commuting qubit observables and analyze multi-time correlators 〈i κ1 (t1) ^i κN (tN) 〉 for output signals i κ (t) from the detectors. Both informational (''spooky'') and phase backactions from cQED-type measurements with phase-sensitive amplifiers are taken into account. We find an excellent agreement between analytical results and experimental data for two-time correlators of the output signals from simultaneous measurement of qubit observables σx and σφ =σx cosφ +σy sinφ . The correlators can be used to extract small deviations of experimental parameters, e.g., phase backaction and residual Rabi frequency. The multi-time correlators are important in analysis of Bacon-Shor error correction/detection codes, operated with continuous measurements.

Eddy Correlation Flux Measurement System (ECOR) Handbook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, DR

2011-01-31

The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration.

Transvaginal ultrasonographic measurement of cervical length in asymptomatic high-risk women with a short cervical length in the previous pregnancy.

PubMed

Crane, J M G; Hutchens, D

2011-07-01

To determine if asymptomatic women at high risk of preterm delivery who had a short cervical length in their previous pregnancy and delivered at term are at increased risk of having a short cervical length in their next pregnancy, and whether they are at increased risk of preterm birth. This retrospective cohort study included high-risk (those with a history of spontaneous preterm birth, uterine anomaly or excisional treatment for cervical dysplasia) asymptomatic women who were pregnant with a singleton gestation delivering between April 2003 and March 2010, who had had a previous pregnancy and who had transvaginal ultrasonographic cervical length measurement performed at 16-30 weeks' gestation in both pregnancies. Comparison was among women who had a short cervical length (< 3.0 cm) in their previous pregnancy but delivered at term in that pregnancy (Short Term Group), women with a history of a normal cervical length (≥ 3.0 cm) in their previous pregnancy delivering at term (Long Term Group), and women who had a short cervical length (< 3.0 cm) in their previous pregnancy delivering preterm (Short Preterm Group). Primary outcomes were spontaneous preterm birth at < 37 weeks' gestation and cervical length. Secondary outcomes were spontaneous preterm birth at < 35 weeks and < 32 weeks, low birth weight, maternal outcomes and neonatal morbidity. A total of 62 women were included. Women in the Short Term Group were more likely to have a short cervical length in their next pregnancy compared with those in the Long Term Group (10/23 (43.5%) vs. 4/26 (15.4%), respectively) but not as likely as women in the Short Preterm Group (9/13 (69.2%); P=0.003). Women in the Short Term Group were not at an increased risk of spontaneous preterm birth at < 37 weeks in the next pregnancy compared with women in the Long Term Group (2/23 (8.7%) vs. 2/26 (7.7%), respectively), but women in the Short Preterm Group were at an increased risk (6/13 (46.2%); P<0.0001). Compared with women in

Mean bond-length variations in crystals for ions bonded to oxygen

PubMed Central

2017-01-01

Variations in mean bond length are examined in oxide and oxysalt crystals for 55 cation configurations bonded to O2−. Stepwise multiple regression analysis shows that mean bond length is correlated to bond-length distortion in 42 ion configurations at the 95% confidence level, with a mean coefficient of determination (〈R 2〉) of 0.35. Previously published correlations between mean bond length and mean coordination number of the bonded anions are found not to be of general applicability to inorganic oxide and oxysalt structures. For two of 11 ions tested for the 95% confidence level, mean bond lengths predicted using a fixed radius for O2− are significantly more accurate as those predicted using an O2− radius dependent on coordination number, and are statistically identical otherwise. As a result, the currently accepted ionic radii for O2− in different coordinations are not justified by experimental data. Previously reported correlation between mean bond length and the mean electronegativity of the cations bonded to the oxygen atoms of the coordination polyhedron is shown to be statistically insignificant; similar results are obtained with regard to ionization energy. It is shown that a priori bond lengths calculated for many ion configurations in a single structure-type leads to a high correlation between a priori and observed mean bond lengths, but a priori bond lengths calculated for a single ion configuration in many different structure-types leads to negligible correlation between a priori and observed mean bond lengths. This indicates that structure type has a major effect on mean bond length, the magnitude of which goes beyond that of the other variables analyzed here.

Relationship between axial length of the emmetropic eye and the age, body height, and body weight of schoolchildren.

PubMed

Selović, Alen; Juresa, Vesna; Ivankovic, Davor; Malcic, Davor; Selović Bobonj, Gordana

2005-01-01

This report assesses the relationship of axial length of emmetropic (without refractive error) eyes to age, height, and weight in 1,600 Croatian schoolchildren. Axial eye lengths were determined by an ultrasonic eye biometry (A scan). Axial length of both eyes increases with age, height, and weight but shows a closer correlation to height and weight than to age. Boys have a significantly longer axial eye length than girls (P < 0.01). Boys or girls of similar or nearing body height and body weight and with emmetropic eyes have close linear measures of anatomic eye structures within their sex, regardless their age. Body height demonstrates the closest correlation to the growth and development of the emmetropic eye. Copyright 2005 Wiley-Liss, Inc.

Influence of the length of institutionalization on older adults' postural balance and risk of falls: a transversal study.

PubMed

Batista, Wagner Oliveira; Alves Junior, Edmundo de Drummond; Porto, Flávia; Pereira, Fabio Dutra; Santana, Rosimere Ferreira; Gurgel, Jonas Lírio

2014-01-01

to ascertain the influence of the length of institutionalization on older adults' balance and risk of falls. to evaluate the risk of falls, the Berg Balance Scale and the Timed Get Up and Go test were used; and for measuring postural balance, static stabilometry was used, with acquisition of the elliptical area of 95% and mean velocities on the x and y axes of center of pressure displacement. Parametric and nonparametric measures of association and comparison (α<0.05) were used. there was no significant correlation between the length of institutionalization and the tests for evaluation of risk of falling, neither was there difference between groups and within subgroups, stratified by length of institutionalization and age. In the stabilometric measurements, there was a negative correlation between the parameters analyzed and the length of institutionalization, and difference between groups and within subgroups. this study's results point to the difficulty of undertaking postural control tasks, showing a leveling below the clinical tests' reference scores. In the stabilometric behavior, one should note the reduction of the parameters as the length of institutionalization increases, contradicting the assumptions. This study's results offer support for the development of a multi-professional model for intervention with the postural control and balance of older adults living in homes for the aged.

Single-Camera-Based Method for Step Length Symmetry Measurement in Unconstrained Elderly Home Monitoring.

PubMed

Cai, Xi; Han, Guang; Song, Xin; Wang, Jinkuan

2017-11-01

single-camera-based gait monitoring is unobtrusive, inexpensive, and easy-to-use to monitor daily gait of seniors in their homes. However, most studies require subjects to walk perpendicularly to camera's optical axis or along some specified routes, which limits its application in elderly home monitoring. To build unconstrained monitoring environments, we propose a method to measure step length symmetry ratio (a useful gait parameter representing gait symmetry without significant relationship with age) from unconstrained straight walking using a single camera, without strict restrictions on walking directions or routes. according to projective geometry theory, we first develop a calculation formula of step length ratio for the case of unconstrained straight-line walking. Then, to adapt to general cases, we propose to modify noncollinear footprints, and accordingly provide general procedure for step length ratio extraction from unconstrained straight walking. Our method achieves a mean absolute percentage error (MAPE) of 1.9547% for 15 subjects' normal and abnormal side-view gaits, and also obtains satisfactory MAPEs for non-side-view gaits (2.4026% for 45°-view gaits and 3.9721% for 30°-view gaits). The performance is much better than a well-established monocular gait measurement system suitable only for side-view gaits with a MAPE of 3.5538%. Independently of walking directions, our method can accurately estimate step length ratios from unconstrained straight walking. This demonstrates our method is applicable for elders' daily gait monitoring to provide valuable information for elderly health care, such as abnormal gait recognition, fall risk assessment, etc. single-camera-based gait monitoring is unobtrusive, inexpensive, and easy-to-use to monitor daily gait of seniors in their homes. However, most studies require subjects to walk perpendicularly to camera's optical axis or along some specified routes, which limits its application in elderly home monitoring

The ergonomic relevance of anthropometrical proportions. Part I: body length measures.

PubMed

Küchmeister, Gerd; Behrenbruch, Kay; Ursula, Pieper; Leyk, Dieter

2009-06-01

Anthropometrical findings about proportions of the human body have a long tradition; most of them, however, are rather theoretical. To improve this situation a pragmatic and applicable definition of proportions, normal as well as deviating, is needed. The purpose of this paper is to set up three proportion types for body length measures: leggy-normal-stocky, and their rate in the population of adults in an industrial society (Germany). Based on queries of an actual anthropometrical database metrical limits for these three types are suggested regarding their influence on the most important body length measures in standing and sitting positions. The number of cases with normal proportions is about 60%, leggy and stocky types both reaching up to 20%. The metrical limits are proposed in order to account for differences between those proportion types which are relevant for ergonomics. When solving complex multidimensional design tasks (e.g. workplaces, vehicle interior design, personal equipment) users of anthropometrical data who do not have the opportunity to work with multivariate databases need supplementary information about the proportions of the human body. For this reason such supplementary information concerning proportions is being given here by physiological anthropologists. The application of the findings presented is exemplified in scenarios of ergonomic relevance.

Universality of modulation length and time exponents.

PubMed

Chakrabarty, Saurish; Dobrosavljević, Vladimir; Seidel, Alexander; Nussinov, Zohar

2012-10-01

We study systems with a crossover parameter λ, such as the temperature T, which has a threshold value λ(*) across which the correlation function changes from exhibiting fixed wavelength (or time period) modulations to continuously varying modulation lengths (or times). We introduce a hitherto unknown exponent ν(L) characterizing the universal nature of this crossover and compute its value in general instances. This exponent, similar to standard correlation length exponents, is obtained from motion of the poles of the momentum (or frequency) space correlation functions in the complex k-plane (or ω-plane) as the parameter λ is varied. Near the crossover (i.e., for λ→λ(*)), the characteristic modulation wave vector K(R) in the variable modulation length "phase" is related to that in the fixed modulation length "phase" q via |K(R)-q|[proportionality]|T-T(*)|(νL). We find, in general, that ν(L)=1/2. In some special instances, ν(L) may attain other rational values. We extend this result to general problems in which the eigenvalue of an operator or a pole characterizing general response functions may attain a constant real (or imaginary) part beyond a particular threshold value λ(*). We discuss extensions of this result to multiple other arenas. These include the axial next-nearest-neighbor Ising (ANNNI) model. By extending our considerations, we comment on relations pertaining not only to the modulation lengths (or times), but also to the standard correlation lengths (or times). We introduce the notion of a Josephson time scale. We comment on the presence of aperiodic "chaotic" modulations in "soft-spin" and other systems. These relate to glass-type features. We discuss applications to Fermi systems, with particular application to metal to band insulator transitions, change of Fermi surface topology, divergent effective masses, Dirac systems, and topological insulators. Both regular periodic and glassy (and spatially chaotic behavior) may be found in

Vocal tract length and acoustics of vocalization in the domestic dog (Canis familiaris).

PubMed

Riede, T; Fitch, T

1999-10-01

The physical nature of the vocal tract results in the production of formants during vocalisation. In some animals (including humans), receivers can derive information (such as body size) about sender characteristics on the basis of formant characteristics. Domestication and selective breeding have resulted in a high variability in head size and shape in the dog (Canis familiaris), suggesting that there might be large differences in the vocal tract length, which could cause formant behaviour to affect interbreed communication. Lateral radiographs were made of dogs from several breeds ranging in size from a Yorkshire terrier (2.5 kg) to a German shepherd (50 kg) and were used to measure vocal tract length. In addition, we recorded an acoustic signal (growling) from some dogs. Significant correlations were found between vocal tract length, body mass and formant dispersion, suggesting that formant dispersion can deliver information about the body size of the vocalizer. Because of the low correlation between vocal tract length and the first formant, we predict a non-uniform vocal tract shape.

Extracting p Λ scattering lengths from heavy ion collisions

NASA Astrophysics Data System (ADS)

Shapoval, V. M.; Erazmus, B.; Lednicky, R.; Sinyukov, Yu. M.

2015-09-01

The source radii previously extracted by the STAR Collaboration from the p -Λ ⊕p ¯-Λ ¯ and p ¯-Λ ⊕p -Λ ¯ correlation functions measured in 10% most central Au+Au collisions at top Relativistic Heavy Ion Collider (RHIC) energy, √{sN N}=200 GeV, differ by a factor of 2. The probable reason for this is the neglect of residual correlation effect in the STAR analysis. In the present paper we analyze baryon correlation functions within the Lednický and Lyuboshitz analytical model, extended to effectively account for the residual correlation contribution. Different analytical approximations for such a contribution are considered. We also use the averaged source radii extracted from hydrokinetic model (HKM) simulations to fit the experimental data. In contrast to the STAR experimental study, the calculations in HKM show both p Λ and p Λ ¯ radii to be quite close, as expected from theoretical considerations. Using the effective Gaussian parametrization of residual correlations we obtain a satisfactory fit to the measured baryon-antibaryon correlation function with the HKM source radius value 3.28 fm. The baryon-antibaryon spin-averaged strong interaction scattering length is also extracted from the fit to the experimental correlation function.

Relating quantum coherence and correlations with entropy-based measures.

PubMed

Wang, Xiao-Li; Yue, Qiu-Ling; Yu, Chao-Hua; Gao, Fei; Qin, Su-Juan

2017-09-21

Quantum coherence and quantum correlations are important quantum resources for quantum computation and quantum information. In this paper, using entropy-based measures, we investigate the relationships between quantum correlated coherence, which is the coherence between subsystems, and two main kinds of quantum correlations as defined by quantum discord as well as quantum entanglement. In particular, we show that quantum discord and quantum entanglement can be well characterized by quantum correlated coherence. Moreover, we prove that the entanglement measure formulated by quantum correlated coherence is lower and upper bounded by the relative entropy of entanglement and the entanglement of formation, respectively, and equal to the relative entropy of entanglement for all the maximally correlated states.

Continuous quantum measurement with independent detector cross correlations.

PubMed

Jordan, Andrew N; Büttiker, Markus

2005-11-25

We investigate the advantages of using two independent, linear detectors for continuous quantum measurement. For single-shot measurement, the detection process may be quantum limited if the detectors are twins. For weak continuous measurement, cross correlations allow a violation of the Korotkov-Averin bound for the detector's signal-to-noise ratio. The joint weak measurement of noncommuting observables is also investigated, and we find the cross correlation changes sign as a function of frequency, reflecting a crossover from incoherent relaxation to coherent, out of phase oscillations. Our results are applied to a double quantum-dot charge qubit, simultaneously measured by two quantum point contacts.

Cosmological velocity correlations - Observations and model predictions

NASA Technical Reports Server (NTRS)

Gorski, Krzysztof M.; Davis, Marc; Strauss, Michael A.; White, Simon D. M.; Yahil, Amos

1989-01-01

By applying the present simple statistics for two-point cosmological peculiar velocity-correlation measurements to the actual data sets of the Local Supercluster spiral galaxy of Aaronson et al. (1982) and the elliptical galaxy sample of Burstein et al. (1987), as well as to the velocity field predicted by the distribution of IRAS galaxies, a coherence length of 1100-1600 km/sec is obtained. Coherence length is defined as that separation at which the correlations drop to half their zero-lag value. These results are compared with predictions from two models of large-scale structure formation: that of cold dark matter and that of baryon isocurvature proposed by Peebles (1980). N-body simulations of these models are performed to check the linear theory predictions and measure sampling fluctuations.

Multifunctional optical correlator for picosecond ultraviolet laser pulse measurement

DOE PAGES

Rakhman, Abdurahim; Wang, Yang; Garcia, Frances; ...

2014-01-01

A compact optical correlator system that measures both the autocorrelation between two infrared (IR) lights and the cross-correlation between an IR and an ultraviolet (UV) light using a single nonlinear optical crystal has been designed and experimentally demonstrated. The rapid scanning of optical delay line, switching between auto and cross-correlations, crystal angle tuning, and data acquisition and processing are all computer controlled. Pulse widths of an IR light from a mode-locked laser are measured by the correlator and the results are compared with a direct measurement using a high-speed photodetector system. The correlator has been used to study the parametermore » dependence of the pulse width of a macropulse UV laser designed for laser-assisted hydrogen ion (H-) beam stripping for the Spallation Neutron Source at Oak Ridge National Laboratory.« less

Ultrasound cervical length measurement in prediction of labor induction outcome.

PubMed

Kehila, M; Abouda, H S; Sahbi, K; Cheour, H; Chanoufi, M Badis

2016-05-17

Induction of labor is one of the most common procedures in modern obstetrics, with an incidence of approximately 20% of all deliveries. Not all of these inductions result in vaginal delivery; some lead to cesarean sections, either for emergency reasons or for failed induction. That's why, It seems necessary to outline strategies for the improvement of the success rate of induced deliveries. Traditionally, the identification of women in whom labor induction is more likely to be successful is based on the Bishop score. However, several studies have shown it to be subjective, with high variation and a poor predictor of the outcome of labor induction. Transvaginal sonography for cervical measurement can be a more objective criterion in assessing the success of labor induction. Many studies have been done recently to compare cervical measurement and Bishop Score in labor induction.This paper reviewed the literature that evaluated sonographic cervical length measurement to predict induction of labor outcome.

Image correlation microscopy for uniform illumination.

PubMed

Gaborski, T R; Sealander, M N; Ehrenberg, M; Waugh, R E; McGrath, J L

2010-01-01

Image cross-correlation microscopy is a technique that quantifies the motion of fluorescent features in an image by measuring the temporal autocorrelation function decay in a time-lapse image sequence. Image cross-correlation microscopy has traditionally employed laser-scanning microscopes because the technique emerged as an extension of laser-based fluorescence correlation spectroscopy. In this work, we show that image correlation can also be used to measure fluorescence dynamics in uniform illumination or wide-field imaging systems and we call our new approach uniform illumination image correlation microscopy. Wide-field microscopy is not only a simpler, less expensive imaging modality, but it offers the capability of greater temporal resolution over laser-scanning systems. In traditional laser-scanning image cross-correlation microscopy, lateral mobility is calculated from the temporal de-correlation of an image, where the characteristic length is the illuminating laser beam width. In wide-field microscopy, the diffusion length is defined by the feature size using the spatial autocorrelation function. Correlation function decay in time occurs as an object diffuses from its original position. We show that theoretical and simulated comparisons between Gaussian and uniform features indicate the temporal autocorrelation function depends strongly on particle size and not particle shape. In this report, we establish the relationships between the spatial autocorrelation function feature size, temporal autocorrelation function characteristic time and the diffusion coefficient for uniform illumination image correlation microscopy using analytical, Monte Carlo and experimental validation with particle tracking algorithms. Additionally, we demonstrate uniform illumination image correlation microscopy analysis of adhesion molecule domain aggregation and diffusion on the surface of human neutrophils.

Measuring the nose in septorhinoplasty patients: ultrasonographic standard values and clinical correlations.

PubMed

Stenner, Markus; Koopmann, Mario; Rudack, Claudia

2017-02-01

Although septorhinoplasty is the most commonly performed operation in plastic surgery, and the surgical plan as well as its outcome is directly related to the configuration of the anatomical structures in the nose, these are not routinely assessed preoperatively. The aim of our study was to evaluate the nasal soft tissue and cartilaginous structures by means of high-resolution ultrasonography to set up clinical correlations and standard values. We examined 44 patients before septorhinoplasty by high-resolution ultrasonography in noncontact mode. All pictures were quantitatively evaluated by measuring 13 lengths and 4 ratios. All patients underwent a rhinomanometry measuring the nasal air flow. Besides others, men as well as older patients have a significantly thicker alar cartilage. Patients with thinner alar cartilages have a significantly smaller interdomal distance as well as significantly thinner upper lateral cartilages. The soft tissue above the bony dorsum was significantly thicker in older patients. Younger patients have significantly thicker soft tissue in relation to their cartilage. Patients with thicker soft tissue and thinner cartilage have a smaller tip. The interdomal distance and the thickness of the cartilaginous septum significantly correlated with the nasal air flow. We set up standard values of nasal structures in septorhinoplasty patients which can be used as reference values. By judging cartilage and soft tissue characteristics preoperatively, relevant factors for distinct procedures could be analyzed and the surgical steps can be better planned. Visualization by ultrasonography enables the surgeon to achieve treatment goals in a more predictable fashion.

Photogrammetric Correlation of Face with Frontal Radiographs and Direct Measurements.

PubMed

Negi, Gunjan; Ponnada, Swaroopa; Aravind, N K S; Chitra, Prasad

2017-05-01

Photogrammetry is a science of making measurements from photographs. As cephalometric analysis till date has focused mainly on skeletal relationships, photogrammetry may provide a means to reliably assess and compare soft tissue and hard tissue measurements. To compare and correlate linear measurements taken directly from subject's faces and from standardized frontal cephalometric radiographs and to correlate them with standardized frontal facial photographs of Indian population and to obtain mean values. A cross-sectional study was conducted on 30 subjects of Indian origin. Frontal cephalograms and standardized frontal photographs were obtained from subjects in the age group of 18- 25 years. Vernier calipers were used to obtain facial measurements directly. Photographs and radiographs were uploaded and measured using Nemoceph software. Analogous cephalometric, photographic and direct measurements were compared by one-way ANOVA to assess Pearson correlation coefficients for 12 linear measurements (6 vertical, 6 horizontal). Bonferroni post-hoc test was done for pair wise comparison. Among all measurements used, O R -O L (orbitale right-orbitale left) showed a high correlation r = 0.76, 0.70, 0.71. There was moderate correlation with En R -En L (endocanthion rt - endocanthion lt) r 2 = 0.62, 0.68, 0.68. Highly significant correlation was evident with N-Sn, En R -En L and Ag R -Ag L with p<0.001. A statistically significant correlation was found between photographic, radiographic and direct measurements. Therefore, photogrammetry has proven to be an alternative diagnostic tool that can be used in epidemiologic studies when there is a need for a simple, basic, non-invasive and cost-effective method.

Comparison of Calculations and Measurements of the Off-Axis Radiation Dose (SI) in Liquid Nitrogen as a Function of Radiation Length.

DTIC Science & Technology

1984-12-01

radiation lengths. The off-axis dose in Silicon was calculated using the electron/photon transport code CYLTRAN and measured using thermal luminescent...various path lengths out to 2 radiation lengths. The cff-axis dose in Silicon was calculated using the electron/photon transport code CYLTRAN and measured... using thermal luminescent dosimeters (TLD’s). Calculations were performed on a CDC-7600 computer at Los Alamos National Laboratory and measurements

Direct measurements of fluorine atom concentration, gain length and small signal gain in an hydrogen fluoride overtone laser

NASA Astrophysics Data System (ADS)

Wisniewski, Charles F.; Hewett, Kevin B.; Manke, Gerald C., II; Randall Truman, C.; Hager, Gordon D.

2003-03-01

Experimental techniques have been developed to directly measure the concentration of fluorine atoms, the gain length and the small signal gain in a hydrogen fluoride 5 cm slit nozzle laser. A gas phase titration technique was utilized to measure the fluorine atom concentration using HCl as the titrant. The gain length was measured using a pitot probe to locate the interface of the primary flow with the high Mach number shroud flows. A tunable diode laser was utilized to perform small signal gain measurements on HF overtone ( ν=2→0) transitions.

Exploring the spatial heterogeneity of terraced landscapes using LiDAR: the Slope Local Length of Auto-Correlation (SLLAC).

NASA Astrophysics Data System (ADS)

Sofia, Giulia; Marinello, Francesco; Tarolli, Paolo

2014-05-01

Length of Auto-Correlation", or SLLAC map. The SLLAC map texture is characterized by the presence of peculiar elongated fibers that change depending on the landscape morphology, and on the type of terracing system. The differences in texture can be measured, and they can be used to discriminate terraced areas from more natural ones. Given the raising importance of these landscapes, the proposed procedure can offer an important and promising tool to explore the spatial heterogeneity of terraced sites.

Evaluation of telomere length in human cardiac tissues using cardiac quantitative FISH.

PubMed

Sharifi-Sanjani, Maryam; Meeker, Alan K; Mourkioti, Foteini

2017-09-01

Telomere length has been correlated with various diseases, including cardiovascular disease and cancer. The use of currently available telomere-length measurement techniques is often restricted by the requirement of a large amount of cells (Southern-based techniques) or the lack of information on individual cells or telomeres (PCR-based methods). Although several methods have been used to measure telomere length in tissues as a whole, the assessment of cell-type-specific telomere length provides valuable information on individual cell types. The development of fluorescence in situ hybridization (FISH) technologies enables the quantification of telomeres in individual chromosomes, but the use of these methods is dependent on the availability of isolated cells, which prevents their use with fixed archival samples. Here we describe an optimized quantitative FISH (Q-FISH) protocol for measuring telomere length that bypasses the previous limitations by avoiding contributions from undesired cell types. We have used this protocol on small paraffin-embedded cardiac-tissue samples. This protocol describes step-by-step procedures for tissue preparation, permeabilization, cardiac-tissue pretreatment and hybridization with a Cy3-labeled telomeric repeat complementing (CCCTAA) 3 peptide nucleic acid (PNA) probe coupled with cardiac-specific antibody staining. We also describe how to quantify telomere length by means of the fluorescence intensity and area of each telomere within individual nuclei. This protocol provides comparative cell-type-specific telomere-length measurements in relatively small human cardiac samples and offers an attractive technique to test hypotheses implicating telomere length in various cardiac pathologies. The current protocol (from tissue collection to image procurement) takes ∼28 h along with three overnight incubations. We anticipate that the protocol could be easily adapted for use on different tissue types.

Measuring (subglacial) bedform orientation, length, and longitudinal asymmetry - Method assessment.

PubMed

Jorge, Marco G; Brennand, Tracy A

2017-01-01

Geospatial analysis software provides a range of tools that can be used to measure landform morphometry. Often, a metric can be computed with different techniques that may give different results. This study is an assessment of 5 different methods for measuring longitudinal, or streamlined, subglacial bedform morphometry: orientation, length and longitudinal asymmetry, all of which require defining a longitudinal axis. The methods use the standard deviational ellipse (not previously applied in this context), the longest straight line fitting inside the bedform footprint (2 approaches), the minimum-size footprint-bounding rectangle, and Euler's approximation. We assess how well these methods replicate morphometric data derived from a manually mapped (visually interpreted) longitudinal axis, which, though subjective, is the most typically used reference. A dataset of 100 subglacial bedforms covering the size and shape range of those in the Puget Lowland, Washington, USA is used. For bedforms with elongation > 5, deviations from the reference values are negligible for all methods but Euler's approximation (length). For bedforms with elongation < 5, most methods had small mean absolute error (MAE) and median absolute deviation (MAD) for all morphometrics and thus can be confidently used to characterize the central tendencies of their distributions. However, some methods are better than others. The least precise methods are the ones based on the longest straight line and Euler's approximation; using these for statistical dispersion analysis is discouraged. Because the standard deviational ellipse method is relatively shape invariant and closely replicates the reference values, it is the recommended method. Speculatively, this study may also apply to negative-relief, and fluvial and aeolian bedforms.

Nonlocal correlations in a macroscopic measurement scenario

NASA Astrophysics Data System (ADS)

Kunkri, Samir; Banik, Manik; Ghosh, Sibasish

2017-02-01

Nonlocality is one of the main characteristic features of quantum systems involving more than one spatially separated subsystem. It is manifested theoretically as well as experimentally through violation of some local realistic inequality. On the other hand, classical behavior of all physical phenomena in the macroscopic limit gives a general intuition that any physical theory for describing microscopic phenomena should resemble classical physics in the macroscopic regime, the so-called macrorealism. In the 2-2-2 scenario (two parties, with each performing two measurements and each measurement having two outcomes), contemplating all the no-signaling correlations, we characterize which of them would exhibit classical (local realistic) behavior in the macroscopic limit. Interestingly, we find correlations which at the single-copy level violate the Bell-Clauser-Horne-Shimony-Holt inequality by an amount less than the optimal quantum violation (i.e., Cirel'son bound 2 √{2 } ), but in the macroscopic limit gives rise to a value which is higher than 2 √{2 } . Such correlations are therefore not considered physical. Our study thus provides a sufficient criterion to identify some of unphysical correlations.

Reexamining the iconic dihadron correlation measurement demonstrating jet quenching

NASA Astrophysics Data System (ADS)

Nattrass, Christine

2018-03-01

Early measurements at the BNL Relativistic Heavy Ion Collider (RHIC) demonstrated jet quenching through the suppression of pairs of high momentum hadrons. These dihadron correlations have a large correlated background. As understanding of the background improved, it was recognized in the field that a significant term was omitted from the background and several dihadron correlation results were quantitatively and qualitatively incorrect. The original measurements demonstrating jet quenching have not been revisited. These measurements are repeated in this paper in a kinematic range similar to the original measurement using publicly available data, applying current knowledge about the background. The new results are qualitatively consistent with the previous results, demonstrating complete suppression of the away side within uncertainties.

Lateral column length in adult flatfoot deformity.

PubMed

Kang, Steve; Charlton, Timothy P; Thordarson, David B

2013-03-01

In adult acquired flatfoot deformity, it is unclear whether the lateral column length shortens with progression of the deformity, whether it is short to begin with, or whether it is short at all. To our knowledge, no previous study has examined the lateral column length of patients with adult acquired flatfoot deformity compared to a control population. The purpose of our study was to compare the lateral column length in patients with and without adult acquired flatfoot deformity to see if there was a significant difference. The study was a retrospective radiographic review of 2 foot and ankle fellowship-trained orthopaedic surgeons' patients with adult flatfoot deformity. Our study population consisted of 75 patients, 85 feet (28 male, 57 female) with adult flatfoot deformity with a mean age of 64 (range, 23-93). Our control population consisted of 57 patients and 70 feet (23 male, 47 female) without flatfoot deformity with a mean age of 61 (range, 40-86 years). Weightbearing anteroposterior (AP) and lateral foot radiographs were analyzed for each patient, and the following measurements were made: medial and lateral column lengths, talonavicular uncoverage angle, talus-first metatarsal angle, calcaneal pitch angle, and medial and lateral column heights. An unpaired t test was used to analyze the measurements between the groups. Ten patients' radiographs were remeasured, and correlation coefficients were obtained to assess the reliability of the measuring techniques. For the flatfoot group, the mean medial and lateral column lengths on the AP radiograph were 108.6 mm and 95.8 mm, respectively; the mean talo-navicular uncoverage angle was 26.2 degrees; and the mean talus-first metatarsal angle was 20.0 degrees. In the control group, the mean medial and lateral column lengths on the AP radiograph were 108.8 mm and 96.5 mm, respectively; the mean talo-navicular uncoverage angle was 8.2 degrees; and the mean talus-first metatarsal angle was 7.7 degrees. On the lateral

Indirect measurement of three-photon correlation in nonclassical light sources

NASA Astrophysics Data System (ADS)

Ann, Byoung-moo; Song, Younghoon; Kim, Junki; Yang, Daeho; An, Kyungwon

2016-06-01

We observe the three-photon correlation in nonclassical light sources by using an indirect measurement scheme based on the dead-time effect of photon-counting detectors. We first develop a general theory which enables us to extract the three-photon correlation from the two-photon correlation of an arbitrary light source measured with detectors with finite dead times. We then confirm the validity of our measurement scheme in experiments done with a cavity-QED microlaser operating with a large intracavity mean photon number exhibiting both sub- and super-Poissonian photon statistics. The experimental results are in good agreement with the theoretical expectation. Our measurement scheme provides an alternative approach for N -photon correlation measurement employing (N -1 ) detectors and thus a reduced measurement time for a given signal-to-noise ratio, compared to the usual scheme requiring N detectors.

Enhancing robustness of multiparty quantum correlations using weak measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Uttam, E-mail: uttamsingh@hri.res.in; Mishra, Utkarsh, E-mail: utkarsh@hri.res.in; Dhar, Himadri Shekhar, E-mail: dhar.himadri@gmail.com

Multipartite quantum correlations are important resources for the development of quantum information and computation protocols. However, the resourcefulness of multipartite quantum correlations in practical settings is limited by its fragility under decoherence due to environmental interactions. Though there exist protocols to protect bipartite entanglement under decoherence, the implementation of such protocols for multipartite quantum correlations has not been sufficiently explored. Here, we study the effect of local amplitude damping channel on the generalized Greenberger–Horne–Zeilinger state, and use a protocol of optimal reversal quantum weak measurement to protect the multipartite quantum correlations. We observe that the weak measurement reversal protocol enhancesmore » the robustness of multipartite quantum correlations. Further it increases the critical damping value that corresponds to entanglement sudden death. To emphasize the efficacy of the technique in protection of multipartite quantum correlation, we investigate two proximately related quantum communication tasks, namely, quantum teleportation in a one sender, many receivers setting and multiparty quantum information splitting, through a local amplitude damping channel. We observe an increase in the average fidelity of both the quantum communication tasks under the weak measurement reversal protocol. The method may prove beneficial, for combating external interactions, in other quantum information tasks using multipartite resources. - Highlights: • Extension of weak measurement reversal scheme to protect multiparty quantum correlations. • Protection of multiparty quantum correlation under local amplitude damping noise. • Enhanced fidelity of quantum teleportation in one sender and many receivers setting. • Enhanced fidelity of quantum information splitting protocol.« less

The predictive value of quantitative fibronectin testing in combination with cervical length measurement in symptomatic women.

PubMed

Bruijn, Merel M C; Kamphuis, Esme I; Hoesli, Irene M; Martinez de Tejada, Begoña; Loccufier, Anne R; Kühnert, Maritta; Helmer, Hanns; Franz, Marie; Porath, Martina M; Oudijk, Martijn A; Jacquemyn, Yves; Schulzke, Sven M; Vetter, Grit; Hoste, Griet; Vis, Jolande Y; Kok, Marjolein; Mol, Ben W J; van Baaren, Gert-Jan

2016-12-01

The combination of the qualitative fetal fibronectin test and cervical length measurement has a high negative predictive value for preterm birth within 7 days; however, positive prediction is poor. A new bedside quantitative fetal fibronectin test showed potential additional value over the conventional qualitative test, but there is limited evidence on the combination with cervical length measurement. The purpose of this study was to compare quantitative fetal fibronectin and qualitative fetal fibronectin testing in the prediction of spontaneous preterm birth within 7 days in symptomatic women who undergo cervical length measurement. We performed a European multicenter cohort study in 10 perinatal centers in 5 countries. Women between 24 and 34 weeks of gestation with signs of active labor and intact membranes underwent quantitative fibronectin testing and cervical length measurement. We assessed the risk of preterm birth within 7 days in predefined strata based on fibronectin concentration and cervical length. Of 455 women who were included in the study, 48 women (11%) delivered within 7 days. A combination of cervical length and qualitative fibronectin resulted in the identification of 246 women who were at low risk: 164 women with a cervix between 15 and 30 mm and a negative fibronectin test (<50 ng/mL; preterm birth rate, 2%) and 82 women with a cervix at >30 mm (preterm birth rate, 2%). Use of quantitative fibronectin alone resulted in a predicted risk of preterm birth within 7 days that ranged from 2% in the group with the lowest fibronectin level (<10 ng/mL) to 38% in the group with the highest fibronectin level (>500 ng/mL), with similar accuracy as that of the combination of cervical length and qualitative fibronectin. Combining cervical length and quantitative fibronectin resulted in the identification of an additional 19 women at low risk (preterm birth rate, 5%), using a threshold of 10 ng/mL in women with a cervix at <15 mm, and 6 women at high risk

Estimation of diaphragm length in patients with severe chronic obstructive pulmonary disease.

PubMed

McKenzie, D K; Gorman, R B; Tolman, J; Pride, N B; Gandevia, S C

2000-11-01

In patients with advanced chronic obstructive pulmonary disease (COPD) diaphragm function may be compromised because of reduced muscle fibre length. Diaphragm length (L(Di)) can be estimated from measurements of transverse diameter of the rib cage (D(Rc)) and the length of the zone of apposition (L(Zapp)) in healthy subjects, but this method has not been validated in patients with COPD. Postero-anterior chest radiographs were obtained at total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV) in nine male patients with severe COPD (mean [S.D.]; FEV(1), 23 [6] %pred.; FRC, 199 [15] %pred.). Radiographs taken at TLC were used to identify the lateral costal insertions of the diaphragm (L(Zapp) assumed to approach zero at TLC). L(Di) was measured directly and also estimated from measurements of L(Zapp) and D(Rc) using a prediction equation derived from healthy subjects. The estimation of L(Di) was highly accurate with an intraclass correlation coefficient of 0.93 and 95% CI of approximately +/-8% of the true value. L(Di) decreased from 426 (64) mm at RV to 305 (31) mm at TLC. As there were only small and variable changes in D(Rc) across the lung volume range, most of the L(Di) changes occurred in the zone of apposition. Additional studies showed that measurements of L(Di) from PA and lateral radiographs performed at different lung volumes were tightly correlated. These results suggest that non-invasive measurements of L(Zapp) in the coronal plane (e.g. using ultrasonography) and D(Rc) (e.g. using magnetometers) can be used to provide an accurate estimate of L(Di) in COPD patients.

Effect of Crystal Defects on Minority Carrier Diffusion Length in 6H SiC Measured Using the Electron Beam Induced Current Method

NASA Technical Reports Server (NTRS)

Tabib-Azar, Massood

1997-01-01

We report values of minority carrier diffusion length in n-type 6H SiC measured using a planar Electron Beam Induced Current (EBIC) method. Values of hole diffusion length in defect free regions of n-type 6H SiC, with a doping concentration of 1.7El7 1/cu cm, ranged from 1.46 microns to 0.68 microns. We next introduce a novel variation of the planar method used above. This 'planar mapping' technique measured diffusion length along a linescan creating a map of diffusion length versus position. This map is then overlaid onto the EBIC image of the corresponding linescan, allowing direct visualization of the effect of defects on minority carrier diffusion length. Measurements of the above n-type 6H SiC resulted in values of hole diffusion length ranging from 1.2 micron in defect free regions to below 0.1 gm at the center of large defects. In addition, measurements on p-type 6H SiC resulted in electron diffusion lengths ranging from 1.42 micron to 0.8 micron.

Precise measurement of single-mode fiber lengths using a gain-switched distributed feedback laser with delayed optical feedback.

PubMed

Wada, Kenji; Matsukura, Satoru; Tanaka, Amaka; Matsuyama, Tetsuya; Horinaka, Hiromichi

2015-09-07

A simple method to measure single-mode optical fiber lengths is proposed and demonstrated using a gain-switched 1.55-μm distributed feedback laser without a fast photodetector or an optical interferometer. From the variation in the amplified spontaneous emission noise intensity with respect to the modulation frequency of the gain switching, the optical length of a 1-km single-mode fiber immersed in water is found to be 1471.043915 m ± 33 μm, corresponding to a relative standard deviation of 2.2 × 10(-8). This optical length is an average value over a measurement time of one minute under ordinary laboratory conditions.

A software program to measure the three-dimensional length of the spine from radiographic images: Validation and reliability assessment for adolescent idiopathic scoliosis.

PubMed

Berger, Steve; Hasler, Carol-Claudius; Grant, Caroline A; Zheng, Guoyan; Schumann, Steffen; Büchler, Philippe

2017-01-01

The aim of this study was to validate a new program which aims at measuring the three-dimensional length of the spine's midline based on two calibrated orthogonal radiographic images. The traditional uniplanar T1-S1 measurement method is not reflecting the actual three dimensional curvature of a scoliotic spine and is therefore not accurate. The Spinal Measurement Software (SMS) is an alternative to conveniently measure the true spine's length. The validity, inter- and intra-observer variability and usability of the program were evaluated. The usability was quantified based on a subjective questionnaire filled by eight participants using the program for the first time. The validity and variability were assessed by comparing the length of five phantom spines measured based on CT-scan data and on radiographic images with the SMS. The lengths were measured independently by each participant using both techniques. The SMS is easy and intuitive to use, even for non-clinicians. The SMS measured spinal length with an error below 2 millimeters compared to length obtained using CT scan datasets. The inter- and intra-observer variability of the SMS measurements was below 5 millimeters. The SMS provides accurate measurement of the spinal length based on orthogonal radiographic images. The software is easy to use and could easily integrate the clinical workflow and replace current approximations of the spinal length based on a single radiographic image such as the traditional T1-S1 measurement. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

Is radiographic measurement of bony landmarks reliable for lateral meniscal sizing?

PubMed

Yoon, Jung-Ro; Kim, Taik-Seon; Lim, Hong-Chul; Lim, Hyung-Tae; Yang, Jae-Hyuk

2011-03-01

The accuracy of meniscal measurement methods is still in debate. The authors' protocol for radiologic measurements will provide reproducible bony landmarks, and this measurement method of the lateral tibial plateau will correlate with the actual anatomic value. Controlled laboratory study. Twenty-five samples of fresh lateral meniscus with attached proximal tibia were obtained during total knee arthroplasty. Each sample was obtained without damage to the meniscus and bony attachment sites. The inclusion criterion was mild to moderate osteoarthritis in patients with mechanical axis deviation of less than 15°. Knees with lateral compartment osteoarthritic change or injured or degenerated menisci were excluded. For the lateral tibial plateau length measurements, the radiographic beam was angled 10° caudally at neutral rotation, which allowed differentiation of the lateral plateau cortical margins from the medial plateau. The transition points were identified and used for length measurement. The values of length were then compared with the conventional Pollard method and the anatomic values. The width measurement was done according to Pollard's protocol. For each knee, the percentage deviation from the anatomic dimension was recorded. Intraobserver error and interobserver error were calculated. The deviation of the authors' radiographic length measurements from anatomic dimensions was 1.4 ± 1.1 mm. The deviation of Pollard's radiographic length measurements was 4.1 ± 2.0 mm. With respect to accuracy-which represents the frequency of measurements that fall within 10% of measurements-the accuracy of authors' length was 98%, whereas for Pollard's method it was 40%. There was a good correlation between anatomic meniscal dimensions and each radiologic plateau dimensions for lateral meniscal width (R(2) = .790) and the authors' lateral meniscal length (R(2) = .823) and fair correlation for Pollard's lateral meniscal length (R(2) = .660). The reliability of each

Reexamining the iconic dihadron correlation measurement demonstrating jet quenching

DOE PAGES

Nattrass, Christine

2018-03-28

We report that early measurements at the BNL Relativistic Heavy Ion Collider (RHIC) demonstrated jet quenching through the suppression of pairs of high momentum hadrons. These dihadron correlations have a large correlated background. As understanding of the background improved, it was recognized in the field that a significant term was omitted from the background and several dihadron correlation results were quantitatively and qualitatively incorrect. The original measurements demonstrating jet quenching have not been revisited. These measurements are repeated in this paper in a kinematic range similar to the original measurement using publicly available data, applying current knowledge about the background.more » Finally, the new results are qualitatively consistent with the previous results, demonstrating complete suppression of the away side within uncertainties.« less

Applications of the first digit law to measure correlations.

PubMed

Gramm, R; Yost, J; Su, Q; Grobe, R

2017-04-01

The quasiempirical Benford law predicts that the distribution of the first significant digit of random numbers obtained from mixed probability distributions is surprisingly meaningful and reveals some universal behavior. We generalize this finding to examine the joint first-digit probability of a pair of two random numbers and show that undetectable correlations by means of the usual covariance-based measure can be identified in the statistics of the corresponding first digits. We illustrate this new measure by analyzing the correlations and anticorrelations of the positions of two interacting particles in their quantum mechanical ground state. This suggests that by using this measure, the presence or absence of correlations can be determined even if only the first digit of noisy experimental data can be measured accurately.

Reexamining the iconic dihadron correlation measurement demonstrating jet quenching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nattrass, Christine

We report that early measurements at the BNL Relativistic Heavy Ion Collider (RHIC) demonstrated jet quenching through the suppression of pairs of high momentum hadrons. These dihadron correlations have a large correlated background. As understanding of the background improved, it was recognized in the field that a significant term was omitted from the background and several dihadron correlation results were quantitatively and qualitatively incorrect. The original measurements demonstrating jet quenching have not been revisited. These measurements are repeated in this paper in a kinematic range similar to the original measurement using publicly available data, applying current knowledge about the background.more » Finally, the new results are qualitatively consistent with the previous results, demonstrating complete suppression of the away side within uncertainties.« less

Measurement of the Length of an Optical Trap

NASA Technical Reports Server (NTRS)

Wrbanek, Susan Y.

2010-01-01

NASA Glenn has been involved in developing optical trapping and optical micromanipulation techniques in order to develop a tool that can be used to probe, characterize, and assemble nano and microscale materials to create microscale sensors for harsh flight environments. In order to be able to assemble a sensor or probe candidate sensor material, it is useful to know how far an optical trap can reach; that is, the distance beyond/below the stable trapping point through which an object will be drawn into the optical trap. Typically, to measure the distance over which an optical trap would influence matter in a horizontal (perpendicular to beam propagation) direction, it was common to hold an object in one optical trap, place a second optical trap a known distance away, turn off the first optical trap, and note if the object was moved into the second trap when it was turned on. The disadvantage of this technique is that it only gives information of trap influence distance in horizontal (x y) directions. No information about the distance of the influence of the trap is gained in the direction of propagation of the beam (the z direction). A method was developed to use a time-of-flight technique to determine the length along the propagation direction of an optical trap beam over which an object may be drawn into the optical trap. Test objects (polystyrene microspheres) were held in an optical trap in a water-filled sample chamber and raised to a pre-determined position near the top of the sample chamber. Next, the test objects were released by blocking the optical trap beam. The test objects were allowed to fall through the water for predetermined periods of time, at the end of which the trapping beam was unblocked. It was noted whether or not the test object returned to the optical trap or continued to fall. This determination of the length of an optical trap's influence by this manner assumes that the test object falls through the water in the sample chamber at

Relating chamber measurements to eddy correlation measurements of methane flux

Treesearch

R.J. Clement; S.B. Verma; E.S. Verry

1995-01-01

Methane fluxes were measured using eddy correlation and chamber techniques during 1991 and 1997 at a peatland in north central Minnesota. Comparisons of the two techniques were made using averages of methane flux data available during 1-week periods. The seasonal patterns of fluxes measured by the two techniques compared well. Chamber flux, in 1991, was about 1.8 mg m...

Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

NASA Astrophysics Data System (ADS)

Gao, Long; Yu, Bo-Xiang; Ding, Ya-Yun; Zhou, Li; Wen, Liang-Jian; Xie, Yu-Guang; Wang, Zhi-Gang; Cai, Xiao; Sun, Xi-Lei; Fang, Jian; Xue, Zhen; Zhang, Ai-Wu; Lü, Qi-Wen; Sun, Li-Jun; Ge, Yong-Shuai; Liu, Ying-Biao; Niu, Shun-Li; Hu, Tao; Cao, Jun; Lü, Jun-Guang

2013-07-01

An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested in a variety of ways. The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

The Association Between Parental Mean Length of Utterance and Language Outcomes in Children With Disabilities: A Correlational Meta-Analysis.

PubMed

Sandbank, Micheal; Yoder, Paul

2016-05-01

The purpose of this correlational meta-analysis was to examine the association between parental utterance length and language outcomes in children with disabilities and whether this association varies according to other child characteristics, such as age and disability type. This association can serve as a starting point for language intervention practices for children with disabilities. We conducted a systematic search of 42 electronic databases to identify relevant studies. Twelve studies reporting on a total of 13 populations (including 257 participants) were identified. A random-effects model was used to estimate a combined effect size across all studies as well as separate effect sizes across studies in each disability category. The combined effect size across all studies suggests a weak positive association between parental input length and child language outcomes. However, subgroup analyses within disability categories suggest that this association may differ for children with autism. Results of 4 studies including 47 children with autism show that parental input length is strongly associated with positive language outcomes in this population. Present evidence suggests that clinicians should reconsider intervention practices that prescribe shorter, grammatically incomplete utterances, particularly when working with children with autism.

Foot length measurements of newborns of high and low risk pregnancies.

PubMed

Salge, Ana Karina Marques; Rocha, Érika Lopes; Gaíva, Maria Aparecida Munhoz; Castral, Thaíla Correa; Guimarães, Janaína Valadares; Xavier, Raphaela Maioni

2017-03-09

Comparing foot length measurements of newborns in high and low risk pregnancies at a public hospital in Goiânia, GO, Brazil. A cross-sectional study carried out between April, 2013 and May, 2015, with a sample consisting of 180 newborns; 106 infants of women from high-risk pregnancies and 74 of women from low-risk pregnancies. Data were descriptively analyzed. Foot length measurement was performed using a stiff transparent plastic ruler, graduated in millimeters. The length of both feet was measured from the tip of the hallux (big toe) to the end of the heel. A statistically significant relationship was found between the foot length and newborn's weight, between the cephalic and thoracic perimeters in the high-risk group and between the cephalic perimeter in the control group. There is a need for creating cut-off points to identify newborns with intrauterine growth disorders using foot length. Comparar as medidas do comprimento hálux-calcâneo de recém-nascidos em gestações de alto e baixo risco em um hospital público de Goiânia, GO. Estudo transversal, realizado no período de abril de 2013 a maio de 2015, cuja amostra constituiu-se de 180 recém-nascidos, 106 filhos de mulheres com gestação de alto risco e 74 de mulheres com gestação de baixo risco. Os dados foram analisados descritivamente. A medida do comprimento hálux-calcâneo foi realizada utilizando-se de régua plástica transparente rígida, graduada em milímetros. Foram medidos ambos os pés, aferindo-se o comprimento da ponta do hálux até a extremidade do calcâneo. Foi encontrada relação estatisticamente significante entre o comprimento hálux-calcâneo e o peso do recém-nascido, entre os perímetros cefálico e torácico no grupo de alto risco e entre o perímetro cefálico no grupo controle. Existe necessidade da criação de pontos de corte para identificar recém-nascidos com desvios de crescimento intrauterino utilizando-se do comprimento hálux-calcâneo. Comparar las mediciones

Distribution of Bell-inequality violation versus multiparty-quantum-correlation measures

NASA Astrophysics Data System (ADS)

Sharma, Kunal; Das, Tamoghna; Sen (de), Aditi; Sen, Ujjwal

Violation of a Bell inequality guarantees the existence of quantum correlations in a shared quantum state. A pure bipartite quantum state, having nonvanishing quantum correlation, always violates a Bell inequality. Such correspondence is absent for multipartite pure quantum states in the case of multipartite correlation function Bell inequalities with two settings at each site. We establish a connection between the monogamy of Bell-inequality violation and multiparty quantum correlations for shared multisite quantum states. We believe that the relation is generic, as it is true for a number of different multisite measures that are defined from radically different perspectives. Precisely, we quantify the multisite-quantum-correlation content in the states by generalized geometric measure, a genuine multisite entanglement measure, as well as three monogamybased multiparty-quantum-correlation measures, viz., 3-tangle, quantum-discord score, and quantum-work-deficit score. We find that generalized Greenberger-Horne-Zeilinger states and another single-parameter family of states, which we refer to as the special Greenberger-Horne-Zeilinger states, have the status of extremal states in such relations.

Distribution of Bell-inequality violation versus multiparty-quantum-correlation measures

NASA Astrophysics Data System (ADS)

Sharma, Kunal; Das, Tamoghna; SenDe, Aditi; Sen, Ujjwal

2016-06-01

Violation of a Bell inequality guarantees the existence of quantum correlations in a shared quantum state. A pure bipartite quantum state, having nonvanishing quantum correlation, always violates a Bell inequality. Such correspondence is absent for multipartite pure quantum states in the case of multipartite correlation function Bell inequalities with two settings at each site. We establish a connection between the monogamy of Bell-inequality violation and multiparty quantum correlations for shared multisite quantum states. We believe that the relation is generic, as it is true for a number of different multisite measures that are defined from radically different perspectives. Precisely, we quantify the multisite-quantum-correlation content in the states by generalized geometric measure, a genuine multisite entanglement measure, as well as three monogamy-based multiparty-quantum-correlation measures, viz., 3-tangle, quantum-discord score, and quantum-work-deficit score. We find that generalized Greenberger-Horne-Zeilinger states and another single-parameter family of states, which we refer to as the special Greenberger-Horne-Zeilinger states, have the status of extremal states in such relations.

The association of calcaneal spur length and clinical and functional parameters in plantar fasciitis.

PubMed

Kuyucu, Ersin; Koçyiğit, Figen; Erdil, Mehmet

2015-09-01

Plantar fasciitis (PF)is the most common cause of plantar heel pain. Despite many treatment alternatives for heel spur, the association of calcaneal spur size with clinical and functional parameters is inconclusive. The objective of this study to investigate the correlation of calcaneal spur length with clinical findings and functional status documented with Foot Function Index in patients with plantar fasciitis. We performed power analysis for the sample size estimation. 87 patients with PF were scrutinized to reach the estimated patient number 75. Computer-aided linear measurements were done for spur length from tip to base in milimeters. Perceived pain intensity was evaluated by visual analog scale (VAS). Patients were asked to rate the pain experienced on a 10-cm VAS. Foot function index was applied to the patients to evaluate pain, disability and activity limitation of the patients. Of the 75 participants, 24 were males (32%) and 51 were females (68%). The mean age was 47 ± 10 years (range 30-65 years). The mean calcaneal spur length was 3.86 ± 3.36 mm (range between 0 and 12.2). Calcaneal spur length was significantly correlated with age (p = 0.003), BMI (p = 0.029), symptom duration, (p = 0.001) VAS (p = 0.003), and FFI total score (p < 0.001). Our study demonstrated that length of the calcaneal spur is significantly correlated with age, BMI, symptom duration, perceived pain, FFI pain and disability subscores, and FFI total scores. The size of the calcaneal spur is an important parameter correlated with pain and functional scores in PF. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Cross-correlation measurements with the EJ-299-33 plastic scintillator

NASA Astrophysics Data System (ADS)

Bourne, Mark M.; Whaley, Jeff; Dolan, Jennifer L.; Polack, John K.; Flaska, Marek; Clarke, Shaun D.; Tomanin, Alice; Peerani, Paolo; Pozzi, Sara A.

2015-06-01

New organic-plastic scintillation compositions have demonstrated pulse-shape discrimination (PSD) of neutrons and gamma rays. We present cross-correlation measurements of 252Cf and mixed uranium-plutonium oxide (MOX) with the EJ-299-33 plastic scintillator. For comparison, equivalent measurements were performed with an EJ-309 liquid scintillator. Offline, digital PSD was applied to each detector. These measurements show that EJ-299-33 sacrifices a factor of 5 in neutron-neutron efficiency relative to EJ-309, but could still utilize the difference in neutron-neutron efficiency and neutron single-to-double ratio to distinguish 252Cf from MOX. These measurements were modeled with MCNPX-PoliMi, and MPPost was used to convert the detailed collision history into simulated cross-correlation distributions. MCNPX-PoliMi predicted the measured 252Cf cross-correlation distribution for EJ-309 to within 10%. Greater photon uncertainty in the MOX sample led to larger discrepancy in the simulated MOX cross-correlation distribution. The modeled EJ-299-33 plastic also gives reasonable agreement with measured cross-correlation distributions, although the MCNPX-PoliMi model appears to under-predict the neutron detection efficiency.

Measuring Scale Errors in a Laser Tracker’s Horizontal Angle Encoder Through Simple Length Measurement and Two-Face System Tests

PubMed Central

Muralikrishnan, B.; Blackburn, C.; Sawyer, D.; Phillips, S.; Bridges, R.

2010-01-01

We describe a method to estimate the scale errors in the horizontal angle encoder of a laser tracker in this paper. The method does not require expensive instrumentation such as a rotary stage or even a calibrated artifact. An uncalibrated but stable length is realized between two targets mounted on stands that are at tracker height. The tracker measures the distance between these two targets from different azimuthal positions (say, in intervals of 20° over 360°). Each target is measured in both front face and back face. Low order harmonic scale errors can be estimated from this data and may then be used to correct the encoder’s error map to improve the tracker’s angle measurement accuracy. We have demonstrated this for the second order harmonic in this paper. It is important to compensate for even order harmonics as their influence cannot be removed by averaging front face and back face measurements whereas odd orders can be removed by averaging. We tested six trackers from three different manufacturers. Two of those trackers are newer models introduced at the time of writing of this paper. For older trackers from two manufacturers, the length errors in a 7.75 m horizontal length placed 7 m away from a tracker were of the order of ± 65 μm before correcting the error map. They reduced to less than ± 25 μm after correcting the error map for second order scale errors. Newer trackers from the same manufacturers did not show this error. An older tracker from a third manufacturer also did not show this error. PMID:27134789

Simultaneous Water Vapor and Dry Air Optical Path Length Measurements and Compensation with the Large Binocular Telescope Interferometer

NASA Technical Reports Server (NTRS)

Defrere, D.; Hinz, P.; Downey, E.; Boehm, M.; Danchi, W. C.; Durney, O.; Ertel, S.; Hill, J. M.; Hoffmann, W. F.; Mennesson, B.;

Is measurement of cervical length an accurate predictive tool in women with a history of preterm delivery who present with threatened preterm labor?

PubMed

Melamed, N; Hiersch, L; Meizner, I; Bardin, R; Wiznitzer, A; Yogev, Y

2014-12-01

To determine whether sonographically measured cervical length is an effective predictive tool in women with threatened preterm labor and a history of past spontaneous preterm delivery. This was a retrospective cohort study of all women with singleton pregnancies who presented with preterm labor at less than 34 + 0 weeks' gestation and underwent sonographic measurement of cervical length in a tertiary medical center between 2007 and 2012. The accuracy of cervical length in predicting preterm delivery was compared between women with and those without a history of spontaneous preterm delivery. Women with risk factors for preterm delivery other than a history of preterm delivery were excluded from both groups. Overall, 1023 women who presented with preterm labor met the study criteria, of whom 136 (13.3%) had a history of preterm delivery (past-PTD group) and 887 (86.7%) had no risk factors for preterm delivery (low-risk group). The rate of preterm delivery was significantly higher for women with a history of preterm delivery (36.8% vs 22.5%; P < 0.001). Cervical length was significantly correlated with the examination-to-delivery interval in low-risk women (r = 0.32, P < 0.001) but not in women who had had a previous preterm delivery (r = 0.07, P = 0.4). On multivariable analysis, cervical length was independently associated with the risk of preterm delivery for women in the low-risk group but not for women with a history of previous preterm delivery. For women with previous preterm delivery who presented with threatened preterm labor, cervical length failed to distinguish between those who did and those who did not deliver prematurely (area under the receiver-operating characteristics curve range, 0.475-0.506). When using standardized thresholds, the sensitivity and specificity of cervical length for the prediction of preterm delivery were significantly lower in women with previous preterm delivery than in women with no risk factors for

SAW correlator spread spectrum receiver

DOEpatents

Brocato, Robert W

2014-04-01

A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n.times.m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.

Neural Measures of a Japanese Consonant Length Discrimination by Japanese and American English Listeners: Affects of Attention

PubMed Central

Hisagi, Miwako; Shafer, Valerie L.; Strange, Winifred; Sussman, Elyse S.

2015-01-01

This study examined automaticity of discrimination of a Japanese length contrast for consonants (miʃi vs. miʃʃi) in native (Japanese) and non-native (American-English) listeners using behavioral measures and the event-related potential (ERP) mismatch negativity (MMN). Attention to the auditory input was manipulated either away from the auditory input via a visual oddball task (Visual Attend), or to the input by asking the listeners to count auditory deviants (Auditory Attend). Results showed a larger MMN when attention was focused on the consonant contrast than away from it for both groups. The MMN was larger for consonant duration increments than decrements. No difference in MMN between the language groups was observed, but the Japanese listeners did show better behavioral discrimination than the American English listeners. In addition, behavioral responses showed a weak, but significant correlation with MMN amplitude. These findings suggest that both acoustic-phonetic properties and phonological experience affects automaticity of speech processing. PMID:26119918

On the chain length dependence of local correlations in polymer melts and a perturbation theory of symmetric polymer blends.

PubMed

Morse, David C; Chung, Jun Kyung

2009-06-14

The self-consistent field (SCF) approach to the thermodynamics of dense polymer liquids is based on the idea that short-range correlations in a polymer liquid are almost independent of how monomers are connected into polymers over larger scales. Some limits of this idea are explored in the context of a perturbation theory for symmetric polymer blends. We consider mixtures of two structurally identical polymers, A and B, in which the AB monomer pair interaction differs slightly from the AA and BB interactions by an amount proportional to a parameter alpha. An expansion of the free energy to first order in alpha yields an excess free energy of mixing per monomer of the form alphaz(N)phi(A)phi(B) in both lattice and continuum models, where z(N) is a measure of the number of intermolecular near neighbors per monomer in a one-component (alpha=0) reference liquid with chains of length N. The quantity z(N) decreases slightly with increasing N because the concentration of intramolecular near neighbors is slightly higher for longer chains, creating a slightly deeper intermolecular correlation hole. We predict that z(N)=z(infinity)[1+betaN(-1/2)], where N is an invariant degree of polymerization and beta=(6/pi)(3/2) is a universal coefficient. This and related predictions about the slight N dependence of local correlations are confirmed by comparison to simulations of a continuum bead-spring model and to published lattice Monte Carlo simulations. We show that a renormalized one-loop theory for blends correctly describes this N dependence of local liquid structure. We also propose a way to estimate the effective interaction parameter appropriate for comparisons of simulation data to SCF theory and to coarse-grained theories of corrections to SCF theory, which is based on an extrapolation of perturbation theory to the limit N-->infinity.

Correlation and agreement: overview and clarification of competing concepts and measures.

PubMed

Liu, Jinyuan; Tang, Wan; Chen, Guanqin; Lu, Yin; Feng, Changyong; Tu, Xin M

2016-04-25

Agreement and correlation are widely-used concepts that assess the association between variables. Although similar and related, they represent completely different notions of association. Assessing agreement between variables assumes that the variables measure the same construct, while correlation of variables can be assessed for variables that measure completely different constructs. This conceptual difference requires the use of different statistical methods, and when assessing agreement or correlation, the statistical method may vary depending on the distribution of the data and the interest of the investigator. For example, the Pearson correlation, a popular measure of correlation between continuous variables, is only informative when applied to variables that have linear relationships; it may be non-informative or even misleading when applied to variables that are not linearly related. Likewise, the intraclass correlation, a popular measure of agreement between continuous variables, may not provide sufficient information for investigators if the nature of poor agreement is of interest. This report reviews the concepts of agreement and correlation and discusses differences in the application of several commonly used measures.

Measuring short electron bunch lengths using coherent smith-purcell radiation

DOEpatents

Nguyen, Dinh C.

1999-01-01

A method is provided for directly determining the length of sub-picosecond electron bunches. A metallic grating is formed with a groove spacing greater than a length expected for the electron bunches. The electron bunches are passed over the metallic grating to generate coherent and incoherent Smith-Purcell radiation. The angular distribution of the coherent Smith-Purcell radiation is then mapped to directly deduce the length of the electron bunches.

Impact of chemotherapy on telomere-length in sporadic and familial breast cancer patients

PubMed Central

Benitez-Buelga, C.; Sanchez-Barroso, L.; Gallardo, M.; Apellániz-Ruiz, María; Inglada-Pérez, L.; Yanowski, K.; Carrillo, J.; Garcia-Estevez, L.; Calvo, I.; Perona, R.; Urioste, M.; Osorio, A.; Blasco, MA.; Rodriguez-Antona, C.; Benitez, J.

2015-01-01

Purpose Recently, we observed that telomeres of BRCA1/2 mutation carriers were shorter than those of controls or sporadic breast cancer patients, suggesting that mutations in these genes might be responsible for this event. Given the contradictory results reported in the literature, we tested whether other parameters, such as chemotherapy, could be modifying telomere-length. Methods We performed a cross-sectional study measuring leukocyte telomere-length of 266 sporadic breasts cancer patients treated with first-line chemotherapy, with a median follow up of 240 days. Additionally, we performed both cross-sectional and longitudinal studies in a series of 236 familial breast cancer patients that included affected and non-affected BRCA1/2 mutation carriers. We have measured in leukocytes from peripheral blood: The telomere-length, percentage of short telomeres (<3Kb), telomerase activity levels and the annual telomere shortening speed. Results In sporadic cases we found that chemotherapy exerts a transient telomere shortening effect (around 2 years) that varies depending on the drug combination. In familial cases, only patients receiving treatment were associated with telomere shortening but they recovered normal telomere-length after a period of two years. Conclusion Chemotherapy affects telomere-length and should be considered in the studies that correlate telomere-length with disease susceptibility. PMID:25528024

Interferometer with Continuously Varying Path Length Measured in Wavelengths to the Reference Mirror

NASA Technical Reports Server (NTRS)

Ohara, Tetsuo (Inventor)

2016-01-01

An interferometer in which the path length of the reference beam, measured in wavelengths, is continuously changing in sinusoidal fashion and the interference signal created by combining the measurement beam and the reference beam is processed in real time to obtain the physical distance along the measurement beam between the measured surface and a spatial reference frame such as the beam splitter. The processing involves analyzing the Fourier series of the intensity signal at one or more optical detectors in real time and using the time-domain multi-frequency harmonic signals to extract the phase information independently at each pixel position of one or more optical detectors and converting the phase information to distance information.

The relationship-based care model: evaluation of the impact on patient satisfaction, length of stay, and readmission rates.

PubMed

Cropley, Stacey

2012-06-01

The objective of this study was to assess the impact of the implementation of the relationship-based care (RBC) model on patient satisfaction, length of stay, and readmission rates in hospitalized patients. RBC model promotes organizational viability in critical areas that measure success, inclusive of clinical quality, patient satisfaction, and robust financial standing. A retrospective secondary analysis of aggregate patient satisfaction data, length of stay, and readmission rates at a rural Texas hospital was reviewed for the years 2009 and 2010. This study compared preimplementation data for year 2009 with postimplementation data for year 2010. Data support the positive influential impact of RBC model. A negative correlation was noted with readmission rates and a concomitant positive correlation with length of stay. Overall satisfaction with nursing did not reveal a significant correlation to the new care model. RBC model supports a patient-centered, collaborative care environment, maximizing potential reimbursement.

Correlations between measurement time and different expansibility of the elastic tape on the rectus femoris and body sway index with plyometric exercise

PubMed Central

Yoon, Jung-Gyu

2018-01-01

[Purpose] The purpose of this study was to examine correlations between measurement time and different expansibility of the elastic tape on the rectus femoris and body sway index with plyometric exercise. [Subjects and Methods] The subjects of this study were 24 healthy men. C90 area, C90 angle, trace length, sway average velocity for body sway index were measured using a force plate by BT4. The collected data were analyzed using Kendall’s coefficient of concordance. [Results] All of body sway index on measuring follow up 24 hours after removing tape were significantly decreased than before and right after plyometric exercise. No significant correlations were found between body sway index and different expansibility of the elastic tape. [Conclusion] It appears that different expansibility of the elastic tape does not affect the ability to body sway index. Carry over effect of taping was verified on measuring follow up 24 hours after removing tape through the decreasing body sway index. PMID:29410564

Correlations between measurement time and different expansibility of the elastic tape on the rectus femoris and body sway index with plyometric exercise.

PubMed

Yoon, Jung-Gyu

2018-01-01

[Purpose] The purpose of this study was to examine correlations between measurement time and different expansibility of the elastic tape on the rectus femoris and body sway index with plyometric exercise. [Subjects and Methods] The subjects of this study were 24 healthy men. C90 area, C90 angle, trace length, sway average velocity for body sway index were measured using a force plate by BT4. The collected data were analyzed using Kendall's coefficient of concordance. [Results] All of body sway index on measuring follow up 24 hours after removing tape were significantly decreased than before and right after plyometric exercise. No significant correlations were found between body sway index and different expansibility of the elastic tape. [Conclusion] It appears that different expansibility of the elastic tape does not affect the ability to body sway index. Carry over effect of taping was verified on measuring follow up 24 hours after removing tape through the decreasing body sway index.

Cross-correlations between crude oil and agricultural commodity markets

NASA Astrophysics Data System (ADS)

Liu, Li

2014-02-01

In this paper, we investigate cross-correlations between crude oil and agricultural commodity markets. Based on a popular statistical test proposed by Podobnik et al. (2009), we find that the linear return cross-correlations are significant at larger lag lengths and the volatility cross-correlations are highly significant at all of the lag lengths under consideration. Using a detrended cross-correlation analysis (DCCA), we find that the return cross-correlations are persistent for corn and soybean and anti-persistent for oat and soybean. The volatility cross-correlations are strongly persistent. Using a nonlinear cross-correlation measure, our results show that cross-correlations are relatively weak but they are significant for smaller time scales. For larger time scales, the cross-correlations are not significant. The reason may be that information transmission from crude oil market to agriculture markets can complete within a certain period of time. Finally, based on multifractal extension of DCCA, we find that the cross-correlations are multifractal and high oil prices partly contribute to food crisis during the period of 2006-mid-2008.

Measuring short electron bunch lengths using coherent Smith-Purcell radiation

DOEpatents

Nguyen, D.C.

1999-03-30

A method is provided for directly determining the length of sub-picosecond electron bunches. A metallic grating is formed with a groove spacing greater than a length expected for the electron bunches. The electron bunches are passed over the metallic grating to generate coherent and incoherent Smith-Purcell radiation. The angular distribution of the coherent Smith-Purcell radiation is then mapped to directly deduce the length of the electron bunches. 8 figs.

Software-based measurement of thin filament lengths: an open-source GUI for Distributed Deconvolution analysis of fluorescence images

PubMed Central

Gokhin, David S.; Fowler, Velia M.

2016-01-01

The periodically arranged thin filaments within the striated myofibrils of skeletal and cardiac muscle have precisely regulated lengths, which can change in response to developmental adaptations, pathophysiological states, and genetic perturbations. We have developed a user-friendly, open-source ImageJ plugin that provides a graphical user interface (GUI) for super-resolution measurement of thin filament lengths by applying Distributed Deconvolution (DDecon) analysis to periodic line scans collected from fluorescence images. In the workflow presented here, we demonstrate thin filament length measurement using a phalloidin-stained cryosection of mouse skeletal muscle. The DDecon plugin is also capable of measuring distances of any periodically localized fluorescent signal from the Z- or M-line, as well as distances between successive Z- or M-lines, providing a broadly applicable tool for quantitative analysis of muscle cytoarchitecture. These functionalities can also be used to analyze periodic fluorescence signals in nonmuscle cells. PMID:27644080

Influence of the length of institutionalization on older adults' postural balance and risk of falls: a transversal study1

PubMed Central

Batista, Wagner Oliveira; Alves, Edmundo de Drummond; Porto, Flávia; Pereira, Fabio Dutra; Santana, Rosimere Ferreira; Gurgel, Jonas Lírio

2014-01-01

OBJECTIVE: to ascertain the influence of the length of institutionalization on older adults' balance and risk of falls. METHOD: to evaluate the risk of falls, the Berg Balance Scale and the Timed Get Up and Go test were used; and for measuring postural balance, static stabilometry was used, with acquisition of the elliptical area of 95% and mean velocities on the x and y axes of center of pressure displacement. Parametric and nonparametric measures of association and comparison (α<0.05) were used. RESULTS: there was no significant correlation between the length of institutionalization and the tests for evaluation of risk of falling, neither was there difference between groups and within subgroups, stratified by length of institutionalization and age. In the stabilometric measurements, there was a negative correlation between the parameters analyzed and the length of institutionalization, and difference between groups and within subgroups. CONCLUSION: this study's results point to the difficulty of undertaking postural control tasks, showing a leveling below the clinical tests' reference scores. In the stabilometric behavior, one should note the reduction of the parameters as the length of institutionalization increases, contradicting the assumptions. This study's results offer support for the development of a multi-professional model for intervention with the postural control and balance of older adults living in homes for the aged. PMID:25296149

Small intestinal growth measures are correlated with feed efficiency in market weight cattle, despite minimal effects of maternal nutrition during early to midgestation.

PubMed

Meyer, A M; Hess, B W; Paisley, S I; Du, M; Caton, J S

2014-09-01

We hypothesized that gestational nutrition would affect calf feed efficiency and small intestinal biology, which would be correlated with feed efficiency. Multiparous beef cows (n = 36) were individually fed 1 of 3 diets from d 45 to 185 of gestation: native grass hay and supplement to meet NRC recommendations (control [CON]), 70% of CON NEm (nutrient restricted [NR]), or a NR diet with a RUP supplement (NR+RUP) to provide similar essential AA as CON. After d 185 of gestation, cows were managed as a single group, and calf individual feed intake was measured with the GrowSafe System during finishing. At slaughter, the small intestine was dissected and sampled. Data were analyzed with calf sex as a block. There was no effect (P ≥ 0.33) of maternal treatment on residual feed intake, G:F, DMI, ADG, or final BW. Small intestinal mass did not differ (P ≥ 0.38) among treatments, although calf small intestinal length tended (P = 0.07) to be greater for NR than NR+RUP. There were no differences (P ≥ 0.20) in calf small intestinal density or jejunal cellularity, proliferation, or vascularity among treatments. Jejunal soluble guanylate cyclase mRNA was greater (P < 0.03) for NR+RUP than CON and NR. Residual feed intake was positively correlated (P ≤ 0.09) with small intestinal mass and relative mass and jejunal RNA content but was negatively correlated (P ≤ 0.09) with jejunal mucosal density and DNA concentration. Gain:feed was positively correlated (P ≤ 0.09) with jejunal mucosal density, DNA, protein, and total cells and was negatively correlated (P ≤ 0.05) with small intestinal relative mass, jejunal RNA, and RNA:DNA. Dry matter intake was positively correlated (P ≤ 0.09) with small intestinal mass, relative mass, length, and density as well as jejunal DNA and protein content, total cells, total vascularity, and kinase insert domain receptor and endothelial nitric oxide synthase 3 mRNA and was negatively correlated (P = 0.02) with relative small intestinal

Representative Elementary Length to Measure Soil Mass Attenuation Coefficient

PubMed Central

Borges, J. A. R.; Pires, L. F.; Costa, J. C.

2014-01-01

With increasing demand for better yield in agricultural areas, soil physical property representative measurements are more and more essential. Nuclear techniques such as computerized tomography (CT) and gamma-ray attenuation (GAT) have been widely employed with this purpose. The soil mass attenuation coefficient (μ s) is an important parameter for CT and GAT analysis. When experimentally determined (μ es), the use of suitable sized samples enable to evaluate it precisely, as well as to reduce measurement time and costs. This study investigated the representative elementary length (REL) of sandy and clayey soils for μ es measurements. Two radioactive sources were employed (241Am and 137Cs), three collimators (2–4 mm diameters), and 14 thickness (x) samples (2–15 cm). Results indicated ideal thickness intervals of 12–15 and 2–4 cm for the sources 137Cs and 241Am, respectively. The application of such results in representative elementary area (REA) evaluations in clayey soil clods via CT indicated that μ es average values obtained for x > 4 cm and source 241Am might induce to the use of samples which are not large enough for soil bulk density evaluations (ρ s). As a consequence, ρ s might be under- or overestimated, generating inaccurate conclusions about the physical quality of the soil under study. PMID:24672338

Influence of Landscape Coverage on Measuring Spatial and Length Properties of Rock Fracture Networks: Insights from Numerical Simulation

NASA Astrophysics Data System (ADS)

Cao, Wenzhuo; Lei, Qinghua

2018-01-01

Natural fractures are ubiquitous in the Earth's crust and often deeply buried in the subsurface. Due to the difficulty in accessing to their three-dimensional structures, the study of fracture network geometry is usually achieved by sampling two-dimensional (2D) exposures at the Earth's surface through outcrop mapping or aerial photograph techniques. However, the measurement results can be considerably affected by the coverage of forests and other plant species over the exposed fracture patterns. We quantitatively study such effects using numerical simulation. We consider the scenario of nominally isotropic natural fracture systems and represent them using 2D discrete fracture network models governed by fractal and length scaling parameters. The groundcover is modelled as random patches superimposing onto the 2D fracture patterns. The effects of localisation and total coverage of landscape patches are further investigated. The fractal dimension and length exponent of the covered fracture networks are measured and compared with those of the original non-covered patterns. The results show that the measured length exponent increases with the reduced localisation and increased coverage of landscape patches, which is more evident for networks dominated by very large fractures (i.e. small underlying length exponent). However, the landscape coverage seems to have a minor impact on the fractal dimension measurement. The research findings of this paper have important implications for field survey and statistical analysis of geological systems.

Role of Weak Measurements on States Ordering and Monogamy of Quantum Correlation

NASA Astrophysics Data System (ADS)

Hu, Ming-Liang; Fan, Heng; Tian, Dong-Ping

2015-01-01

The information-theoretic definition of quantum correlation, e.g., quantum discord, is measurement dependent. By considering the more general quantum measurements, weak measurements, which include the projective measurement as a limiting case, we show that while weak measurements can enable one to capture more quantumness of correlation in a state, it can also induce other counterintuitive quantum effects. Specifically, we show that the general measurements with different strengths can impose different orderings for quantum correlations of some states. It can also modify the monogamous character for certain classes of states as well which may diminish the usefulness of quantum correlation as a resource in some protocols. In this sense, we say that the weak measurements play a dual role in defining quantum correlation.

Axial length and proliferative diabetic retinopathy.

PubMed

Yang, Ko-Jen; Sun, Chi-Chin; Ku, Wan-Chen; Chuang, Lan-Hsin; Ng, Soh Ching; Chou, Kuei-Mei; Kuo, Sheng-Fong; Yeung, Ling

2012-04-01

To determine the correlation between axial length and diabetic retinopathy (DR) in patients with diabetes mellitus for 10 years or more. This study was a prospective, observational, cross-sectional study. Patients with diabetes for 10 years or more were included. We excluded eyes with any other significant ocular disease or any prior intraocular surgery, except uncomplicated cataract surgery. Only one eye of each patient was included as the study eye. The severity of DR was graded as no DR, non-proliferative DR (NPDR), or proliferative DR (PDR). Axial length was measured by A-scan ultrasound (10 MHz Transducer, AL-2000 Biometer/Pachymeter; Tomey, Phoenix, AZ). Univariate logistic regression models were used to evaluate the relationship between the dependent variables (any DR, PDR) and all potential risk factors. Axial length and other factors with p value <0.1 were included in multivariate logistic regression models. Backward selection based on the likelihood ratio statistic was used to select the final models. We included 166 eyes from 166 patients (93 female and 73 male; mean age, 68.8 years). The mean diabetes duration was 15.4 years. Fifty-four (32.5%) eyes had no DR, 72 (43.4%) eyes had NPDR, and 40 (24.1%) eyes had PDR. In univariate analysis, hypertension (p = 0.009), renal impairment (p = 0.079), and insulin use (p = 0.009) were associated with developing any DR. Hypertension (p = 0.042), renal impairment (p = 0.014), insulin use (p = 0.040), pseudophakia (p = 0.019), and axial length (p = 0.076) were associated with developing PDR. In multivariate analysis, hypertension (p = 0.005) and insulin use (p = 0.010) were associated with developing any DR. Hypertension (p = 0.020), renal impairment (p = 0.025), pseudophakia (p = 0.006), and axial length (p = 0.024) were associated with developing PDR. This observational study suggests an inverse relationship between axial length and the development of PDR in patients with diabetes for 10 years or more. No

Method for digital measurement of phase-frequency characteristics for a fixed-length ultrasonic spectrometer

NASA Astrophysics Data System (ADS)

Astashev, M. E.; Belosludtsev, K. N.; Kharakoz, D. P.

2014-05-01

One of the most accurate methods for measuring the compressibility of liquids is resonance measurement of sound velocity in a fixed-length interferometer. This method combines high sensitivity, accuracy, and small sample volume of the test liquid. The measuring principle is to study the resonance properties of a composite resonator that contains a test liquid sample. Ealier, the phase-locked loop (PLL) scheme was used for this. In this paper, we propose an alternative measurement scheme based on digital analysis of harmonic signals, describe the implementation of this scheme using commercially available data acquisition modules, and give examples of test measurements with accuracy evaluations of the results.

Large-scale parent–child comparison confirms a strong paternal influence on telomere length

PubMed Central

Nordfjäll, Katarina; Svenson, Ulrika; Norrback, Karl-Fredrik; Adolfsson, Rolf; Roos, Göran

2010-01-01

Telomere length is documented to have a hereditary component, and both paternal and X-linked inheritance have been proposed. We investigated blood cell telomere length in 962 individuals with an age range between 0 and 102 years. Telomere length correlations were analyzed between parent–child pairs in different age groups and between grandparent–grandchild pairs. A highly significant correlation between the father's and the child's telomere length was observed (r=0.454, P<0.001), independent of the sex of the offspring (father–son: r=0.465, P<0.001; father–daughter: r=0.484, P<0.001). For mothers, the correlations were weaker (mother–child: r=0.148, P=0.098; mother–son: r=0.080, P=0.561; mother–daughter: r=0.297, P=0.013). A positive telomere length correlation was also observed for grandparent–grandchild pairs (r=0.272, P=0.013). Our findings indicate that fathers contribute significantly stronger to the telomere length of the offspring compared with mothers (P=0.012), but we cannot exclude a maternal influence on the daughter's telomeres. Interestingly, the father–child correlations diminished with increasing age (P=0.022), suggesting that nonheritable factors have an impact on telomere length dynamics during life. PMID:19826452

Age Differences in Axial Length, Corneal Curvature, and Corneal Astigmatism in Marfan Syndrome with Ectopia Lentis

PubMed Central

Jing, Qinghe; Tang, Yating; Qian, Dongjin

2018-01-01

Purpose To investigate the differences in axial length, corneal curvature, and corneal astigmatism with age in patients with Marfan syndrome (MFS) and ectopia lentis. Methods A retrospective case series study was conducted. MFS patients with ectopia lentis were divided into groups according to age. Axial length, corneal curvature, and corneal astigmatism were measured. Results This study included 114 MFS patients (215 eyes) with a mean age of 19.0 ± 13.9 years. Axial length differed significantly across age groups in MFS patients (P < 0.001), whereas corneal curvature did not (P = 0.767). Corneal astigmatism was statistically significant throughout the MFS cohort (P = 0.009), but no significant difference was found in young MFS patients (P = 0.838). With increasing age, the orientation of the corneal astigmatism changed from with-the-rule astigmatism to against-the-rule or oblique astigmatism (P < 0.001). A linear correlation analysis showed weak correlations between age and axial length for both eyes and with corneal astigmatism for the left eye, but there was no correlation between age and corneal curvature. Conclusions In MFS, axial length varies with age, corneal curvature remains stable, and corneal astigmatism is higher in young patients and tends to shift toward against-the-rule or oblique astigmatism. Therefore, it is important to consider age when diagnosing MFS with ocular biometric data. PMID:29854424

Is DNA a worm-like chain in Couette flow? In search of persistence length, a critical review.

PubMed

Rittman, Martyn; Gilroy, Emma; Koohya, Hashem; Rodger, Alison; Richards, Adair

2009-01-01

Persistence length is the foremost measure of DNA flexibility. Its origins lie in polymer theory which was adapted for DNA following the determination of BDNA structure in 1953. There is no single definition of persistence length used, and the links between published definitions are based on assumptions which may, or may not be, clearly stated. DNA flexibility is affected by local ionic strength, solvent environment, bound ligands and intrinsic sequence-dependent flexibility. This article is a review of persistence length providing a mathematical treatment of the relationships between four definitions of persistence length, including: correlation, Kuhn length, bending, and curvature. Persistence length has been measured using various microscopy, force extension and solution methods such as linear dichroism and transient electric birefringence. For each experimental method a model of DNA is required to interpret the data. The importance of understanding the underlying models, along with the assumptions required by each definition to determine a value of persistence length, is highlighted for linear dichroism data, where it transpires that no model is currently available for long DNA or medium to high shear rate experiments.

Diffusion length measurements of thin GaAs solar cells by means of energetic electrons

NASA Technical Reports Server (NTRS)

Vonross, O.

1980-01-01

A calculation of the short circuit current density (j sub sc) of a thin GaAs solar cell induced by fast electrons is presented. It is shown that in spite of the disparity in thickness between the N-type portion of the junction and the P-type portion of the junction, the measurement of the bulk diffusion length L sub p of the N-type part of the junction is seriously hampered due to the presence of a sizable contribution to the j sub sc from the P-type region of the junction. Corrections of up to 50% had to be made in order to interpret the data correctly. Since these corrections were not amenable to direct measurements it is concluded that the electron beam method for the determination of the bulk minority carrier diffusion length, which works so well for Si solar cells, is a poor method when applied to thin GaAs cells.

Pi Bond Orders and Bond Lengths

ERIC Educational Resources Information Center

Herndon, William C.; Parkanyi, Cyril

1976-01-01

Discusses three methods of correlating bond orders and bond lengths in unsaturated hydrocarbons: the Pauling theory, the Huckel molecular orbital technique, and self-consistent-field techniques. (MLH)

Correlation between static radiographic measurements and intersegmental angular measurements during gait using a multisegment foot model.

PubMed

Lee, Dong Yeon; Seo, Sang Gyo; Kim, Eo Jin; Kim, Sung Ju; Lee, Kyoung Min; Farber, Daniel C; Chung, Chin Youb; Choi, In Ho

2015-01-01

Radiographic examination is a widely used evaluation method in the orthopedic clinic. However, conventional radiography alone does not reflect the dynamic changes between foot and ankle segments during gait. Multiple 3-dimensional multisegment foot models (3D MFMs) have been introduced to evaluate intersegmental motion of the foot. In this study, we evaluated the correlation between static radiographic indices and intersegmental foot motion indices. One hundred twenty-five females were tested. Static radiographs of full-leg and anteroposterior (AP) and lateral foot views were performed. For hindfoot evaluation, we measured the AP tibiotalar angle (TiTA), talar tilt (TT), calcaneal pitch, lateral tibiocalcaneal angle, and lateral talcocalcaneal angle. For the midfoot segment, naviculocuboid overlap and talonavicular coverage angle were calculated. AP and lateral talo-first metatarsal angles and metatarsal stacking angle (MSA) were measured to assess the forefoot. Hallux valgus angle (HVA) and hallux interphalangeal angle were measured. In gait analysis by 3D MFM, intersegmental angle (ISA) measurements of each segment (hallux, forefoot, hindfoot, arch) were recorded. ISAs at midstance phase were most highly correlated with radiography. Significant correlations were observed between ISA measurements using MFM and static radiographic measurements in the same segment. In the hindfoot, coronal plane ISA was correlated with AP TiTA (P < .001) and TT (P = .018). In the hallux, HVA was strongly correlated with transverse ISA of the hallux (P < .001). The segmental foot motion indices at midstance phase during gait measured by 3D MFM gait analysis were correlated with the conventional radiographic indices. The observed correlation between MFM measurements at midstance phase during gait and static radiographic measurements supports the fundamental basis for the use of MFM in analysis of dynamic motion of foot segment during gait. © The Author(s) 2014.

An apparatus to measure water optical attenuation length for LHAASO-MD

NASA Astrophysics Data System (ADS)

Li, Cong; Xiao, Gang; Feng, Shaohui; Wang, Lingyu; Li, Xiurong; Zuo, Xiong; Cheng, Ning; Wang, Hui; Gao, Bo; Duan, Zhihao; Liu, Jia; He, Huihai; Saeed, Mohsin; Lhaaso Collaboration

2018-06-01

The large high altitude air shower observatory (LHAASO) is being constructed at 4400 m a.s.l. in Daocheng, Sichuan Province, aiming to reveal the secrets of cosmic rays origin. And it has the largest surface muon detector array in the world. Due to the needs of calibration and construction of muon detector, we developed a water optical attenuation measurement device using an 8 m long water tank. The results are presented for filtered water at wavelength of 405 nm, which proves this apparatus can reach an accuracy of about 20% at 100 m. This apparatus has not only a high precision measurement of water attenuation length up to 100 m but is also very convenient to be used, which is crucial for water optical properties study during LHAASO detector construction.

NUTRIENT UPTAKE LENGTH, CHANNEL STRUCTURE, AND TRANSIENT STORAGE IN STREAMS DRAINING HARVESTED AND OLD GROWTH WATERSHEDS

EPA Science Inventory

Channel structure and transient storage were correlated with nutrient uptake length in streams draining old-growth and harvested watersheds in the Cascade Mountains of Oregon, and the redwood forests of northwestern California. Channel width and riparian canopy were measured at 1...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... remainder in inches or common or decimal fractions of the yard or foot except that a dimension of less than... dimension of less than 2 feet (60.96 cm) may be stated in inches. (4) For any commodity for which the... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch...

Exponential smoothing weighted correlations

NASA Astrophysics Data System (ADS)

Pozzi, F.; Di Matteo, T.; Aste, T.

2012-06-01

In many practical applications, correlation matrices might be affected by the "curse of dimensionality" and by an excessive sensitiveness to outliers and remote observations. These shortcomings can cause problems of statistical robustness especially accentuated when a system of dynamic correlations over a running window is concerned. These drawbacks can be partially mitigated by assigning a structure of weights to observational events. In this paper, we discuss Pearson's ρ and Kendall's τ correlation matrices, weighted with an exponential smoothing, computed on moving windows using a data-set of daily returns for 300 NYSE highly capitalized companies in the period between 2001 and 2003. Criteria for jointly determining optimal weights together with the optimal length of the running window are proposed. We find that the exponential smoothing can provide more robust and reliable dynamic measures and we discuss that a careful choice of the parameters can reduce the autocorrelation of dynamic correlations whilst keeping significance and robustness of the measure. Weighted correlations are found to be smoother and recovering faster from market turbulence than their unweighted counterparts, helping also to discriminate more effectively genuine from spurious correlations.

Androgyny: Concept, Measurement, Correlates and Antecedents.

ERIC Educational Resources Information Center

DeFronzo, James; Boudreau, Frances

This paper introduces the concept of psychological androgyny to sociologists, examines the ways in which androgyny has been measured and operationally defined by psychologists, and reviews available research concerning the antecedents and correlates of androgyny. The results of original research conducted with 622 students at the University of…

A Robust State Estimation Framework Considering Measurement Correlations and Imperfect Synchronization

DOE PAGES

Zhao, Junbo; Wang, Shaobu; Mili, Lamine; ...

2018-01-08

Here, this paper develops a robust power system state estimation framework with the consideration of measurement correlations and imperfect synchronization. In the framework, correlations of SCADA and Phasor Measurements (PMUs) are calculated separately through unscented transformation and a Vector Auto-Regression (VAR) model. In particular, PMU measurements during the waiting period of two SCADA measurement scans are buffered to develop the VAR model with robustly estimated parameters using projection statistics approach. The latter takes into account the temporal and spatial correlations of PMU measurements and provides redundant measurements to suppress bad data and mitigate imperfect synchronization. In case where the SCADAmore » and PMU measurements are not time synchronized, either the forecasted PMU measurements or the prior SCADA measurements from the last estimation run are leveraged to restore system observability. Then, a robust generalized maximum-likelihood (GM)-estimator is extended to integrate measurement error correlations and to handle the outliers in the SCADA and PMU measurements. Simulation results that stem from a comprehensive comparison with other alternatives under various conditions demonstrate the benefits of the proposed framework.« less

A Robust State Estimation Framework Considering Measurement Correlations and Imperfect Synchronization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Junbo; Wang, Shaobu; Mili, Lamine

Here, this paper develops a robust power system state estimation framework with the consideration of measurement correlations and imperfect synchronization. In the framework, correlations of SCADA and Phasor Measurements (PMUs) are calculated separately through unscented transformation and a Vector Auto-Regression (VAR) model. In particular, PMU measurements during the waiting period of two SCADA measurement scans are buffered to develop the VAR model with robustly estimated parameters using projection statistics approach. The latter takes into account the temporal and spatial correlations of PMU measurements and provides redundant measurements to suppress bad data and mitigate imperfect synchronization. In case where the SCADAmore » and PMU measurements are not time synchronized, either the forecasted PMU measurements or the prior SCADA measurements from the last estimation run are leveraged to restore system observability. Then, a robust generalized maximum-likelihood (GM)-estimator is extended to integrate measurement error correlations and to handle the outliers in the SCADA and PMU measurements. Simulation results that stem from a comprehensive comparison with other alternatives under various conditions demonstrate the benefits of the proposed framework.« less

Measurement of the full-field polymerization shrinkage and depth of cure of dental composites using digital image correlation.

PubMed

Li, Jianying; Fok, Alex S L; Satterthwaite, Julian; Watts, David C

2009-05-01

The aim of this study was to measure the full-field polymerization shrinkage of dental composites using optical image correlation method. Bar specimens of cross-section 4mm x 2mm and length 10mm approximately were light cured with two irradiances, 450 mW/cm(2) and 180 mW/cm(2), respectively. The curing light was generated with Optilux 501 (Kerr) and the two different irradiances were achieved by adjusting the distance between the light tip and the specimen. A single-camera 2D measuring system was used to record the deformation of the composite specimen for 30 min at a frequency of 0.1 Hz. The specimen surface under observation was sprayed with paint to produce sufficient contrast to allow tracking of individual points on the surface. The curing light was applied to one end of the specimen for 40s during which the painted surface was fully covered. After curing, the cover was removed immediately so that deformation of the painted surface could be recorded by the camera. The images were then analyzed with specialist software and the volumetric shrinkage determined along the beam length. A typical shrinkage strain field obtained on a specimen surface was highly non-uniform, even at positions of constant distance from the irradiation surface, indicating possible heterogeneity in material composition and shrinkage behavior in the composite. The maximum volumetric shrinkage strain of approximately 1.5% occurred at a subsurface distance of about 1mm, instead of at the irradiation surface. After reaching its peak value, the shrinkage strain then gradually decreased with increasing distance along the beam length, before leveling off to a value of approximately 0.2% at a distance of 4-5mm. The maximum volumetric shrinkage obtained agreed well with the value of 1.6% reported by the manufacturer for the composite examined in this work. Using irradiance of 180 mW/cm(2) resulted in only slightly less polymerization shrinkage than using irradiance of 450 mW/cm(2). Compared to the

Atmospheric correlation time measurements using coherent CO2 lidar

NASA Technical Reports Server (NTRS)

Ancellet, G. M.; Menzies, R. T.

1986-01-01

A pulsed TEA-CO2 lidar with coherent detection was used to measure the correlation time of backscatter from an ensemble of atmospheric aerosol particles which are illuminated by the pulsed radiation. The correlation time of the backscatter return signal is important in studies of atmospheric turbulence and its effects on optical propagation and backscatter. If the temporal coherence of the pulse is large enough, then the temporal coherence of the return signal is dominated by the turbulence and shear for a variety of interesting atmospheric conditions. Various techniques for correlation time measurement are discussed and evaluated.

On the importance of measurement error correlations in data assimilation for integrated hydrological models

NASA Astrophysics Data System (ADS)

Camporese, Matteo; Botto, Anna

2017-04-01

Data assimilation is becoming increasingly popular in hydrological and earth system modeling, as it allows us to integrate multisource observation data in modeling predictions and, in doing so, to reduce uncertainty. For this reason, data assimilation has been recently the focus of much attention also for physically-based integrated hydrological models, whereby multiple terrestrial compartments (e.g., snow cover, surface water, groundwater) are solved simultaneously, in an attempt to tackle environmental problems in a holistic approach. Recent examples include the joint assimilation of water table, soil moisture, and river discharge measurements in catchment models of coupled surface-subsurface flow using the ensemble Kalman filter (EnKF). One of the typical assumptions in these studies is that the measurement errors are uncorrelated, whereas in certain situations it is reasonable to believe that some degree of correlation occurs, due for example to the fact that a pair of sensors share the same soil type. The goal of this study is to show if and how the measurement error correlations between different observation data play a significant role on assimilation results in a real-world application of an integrated hydrological model. The model CATHY (CATchment HYdrology) is applied to reproduce the hydrological dynamics observed in an experimental hillslope. The physical model, located in the Department of Civil, Environmental and Architectural Engineering of the University of Padova (Italy), consists of a reinforced concrete box containing a soil prism with maximum height of 3.5 m, length of 6 m, and width of 2 m. The hillslope is equipped with sensors to monitor the pressure head and soil moisture responses to a series of generated rainfall events applied onto a 60 cm thick sand layer overlying a sandy clay soil. The measurement network is completed by two tipping bucket flow gages to measure the two components (subsurface and surface) of the outflow. By collecting

Measurement of q ˆ in Relativistic Heavy Ion Collisions using di-hadron correlations

DOE PAGES

Tannenbaum, M. J.

2017-06-06

The propagation of partons from hard scattering through the Quark Gluon Plasma produced in A+A collisions at RHIC and the LHC is represented in theoretical analyses by the transport coefficientmore » $$\\hat{q}$$ and predicted to cause both energy loss of the outgoing partons, observed as suppression of particles or jets with large transverse momentum p T, and broadening of the azimuthal correlations of the outgoing di-jets or di-hadrons from the outgoing parton-pair, which has not been observed. The widths of azimuthal correlations of di-hadrons with the same trigger particle p Tt and associated p Ta transverse momenta in p+p and Au+Au are so-far statistically indistinguishable as shown in recent as well as older di-hadron measurements and also with jet-hadron and hadron-jet measurements. The azimuthal width of the di-hadron correlations in p+p collisions, beyond the fragmentation transverse momentum, j T, is dominated by k T, the so-called intrinsic transverse momentum of a parton in a nucleon, which can be measured. The broadening should produce a larger k T in A+A than in p+p collisions. The present work introduces the observation that the k T measured in p+p collisions for di-hadrons with p Tt and p Ta must be reduced to compensate for the energy loss of both the trigger and away parent partons when comparing to the k T measured with the same di-hadron p Tt and p Ta in Au+Au collisions. This idea is applied to a recent STAR di-hadron measurement, with result <$$\\hat{q}$$L>=2.1±0.6 GeV 2. This is more precise but in agreement with a theoretical calculation of <$$\\hat{q}$$L>=14$$+42\\atop{-14}$$ GeV 2 using the same data. Assuming a length ≈7 fm for central Au+Au collisions the present result gives $$\\hat{q}$$≈0.30±0.09 GeV 2/fm, in fair agreement with the JET collaboration result from single hadron suppression of $$\\hat{q}$$≈1.2±0.3 GeV 2/fm at an initial time τ 0=0.6 fm/c in Au+Au collisions at √sNN=200 GeV.« less

Measurement of q ˆ in Relativistic Heavy Ion Collisions using di-hadron correlations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tannenbaum, M. J.

The propagation of partons from hard scattering through the Quark Gluon Plasma produced in A+A collisions at RHIC and the LHC is represented in theoretical analyses by the transport coefficientmore » $$\\hat{q}$$ and predicted to cause both energy loss of the outgoing partons, observed as suppression of particles or jets with large transverse momentum p T, and broadening of the azimuthal correlations of the outgoing di-jets or di-hadrons from the outgoing parton-pair, which has not been observed. The widths of azimuthal correlations of di-hadrons with the same trigger particle p Tt and associated p Ta transverse momenta in p+p and Au+Au are so-far statistically indistinguishable as shown in recent as well as older di-hadron measurements and also with jet-hadron and hadron-jet measurements. The azimuthal width of the di-hadron correlations in p+p collisions, beyond the fragmentation transverse momentum, j T, is dominated by k T, the so-called intrinsic transverse momentum of a parton in a nucleon, which can be measured. The broadening should produce a larger k T in A+A than in p+p collisions. The present work introduces the observation that the k T measured in p+p collisions for di-hadrons with p Tt and p Ta must be reduced to compensate for the energy loss of both the trigger and away parent partons when comparing to the k T measured with the same di-hadron p Tt and p Ta in Au+Au collisions. This idea is applied to a recent STAR di-hadron measurement, with result <$$\\hat{q}$$L>=2.1±0.6 GeV 2. This is more precise but in agreement with a theoretical calculation of <$$\\hat{q}$$L>=14$$+42\\atop{-14}$$ GeV 2 using the same data. Assuming a length ≈7 fm for central Au+Au collisions the present result gives $$\\hat{q}$$≈0.30±0.09 GeV 2/fm, in fair agreement with the JET collaboration result from single hadron suppression of $$\\hat{q}$$≈1.2±0.3 GeV 2/fm at an initial time τ 0=0.6 fm/c in Au+Au collisions at √sNN=200 GeV.« less

Single Molecule Bioelectronics and Their Application to Amplification-Free Measurement of DNA Lengths

PubMed Central

Gül, O. Tolga; Pugliese, Kaitlin M.; Choi, Yongki; Sims, Patrick C.; Pan, Deng; Rajapakse, Arith J.; Weiss, Gregory A.; Collins, Philip G.

2016-01-01

As biosensing devices shrink smaller and smaller, they approach a scale in which single molecule electronic sensing becomes possible. Here, we review the operation of single-enzyme transistors made using single-walled carbon nanotubes. These novel hybrid devices transduce the motions and catalytic activity of a single protein into an electronic signal for real-time monitoring of the protein’s activity. Analysis of these electronic signals reveals new insights into enzyme function and proves the electronic technique to be complementary to other single-molecule methods based on fluorescence. As one example of the nanocircuit technique, we have studied the Klenow Fragment (KF) of DNA polymerase I as it catalytically processes single-stranded DNA templates. The fidelity of DNA polymerases makes them a key component in many DNA sequencing techniques, and here we demonstrate that KF nanocircuits readily resolve DNA polymerization with single-base sensitivity. Consequently, template lengths can be directly counted from electronic recordings of KF’s base-by-base activity. After measuring as few as 20 copies, the template length can be determined with <1 base pair resolution, and different template lengths can be identified and enumerated in solutions containing template mixtures. PMID:27348011

Single Molecule Bioelectronics and Their Application to Amplification-Free Measurement of DNA Lengths.

PubMed

Gül, O Tolga; Pugliese, Kaitlin M; Choi, Yongki; Sims, Patrick C; Pan, Deng; Rajapakse, Arith J; Weiss, Gregory A; Collins, Philip G

2016-06-24

As biosensing devices shrink smaller and smaller, they approach a scale in which single molecule electronic sensing becomes possible. Here, we review the operation of single-enzyme transistors made using single-walled carbon nanotubes. These novel hybrid devices transduce the motions and catalytic activity of a single protein into an electronic signal for real-time monitoring of the protein's activity. Analysis of these electronic signals reveals new insights into enzyme function and proves the electronic technique to be complementary to other single-molecule methods based on fluorescence. As one example of the nanocircuit technique, we have studied the Klenow Fragment (KF) of DNA polymerase I as it catalytically processes single-stranded DNA templates. The fidelity of DNA polymerases makes them a key component in many DNA sequencing techniques, and here we demonstrate that KF nanocircuits readily resolve DNA polymerization with single-base sensitivity. Consequently, template lengths can be directly counted from electronic recordings of KF's base-by-base activity. After measuring as few as 20 copies, the template length can be determined with <1 base pair resolution, and different template lengths can be identified and enumerated in solutions containing template mixtures.

Measuring and modeling correlations in multiplex networks.

PubMed

Nicosia, Vincenzo; Latora, Vito

2015-09-01

The interactions among the elementary components of many complex systems can be qualitatively different. Such systems are therefore naturally described in terms of multiplex or multilayer networks, i.e., networks where each layer stands for a different type of interaction between the same set of nodes. There is today a growing interest in understanding when and why a description in terms of a multiplex network is necessary and more informative than a single-layer projection. Here we contribute to this debate by presenting a comprehensive study of correlations in multiplex networks. Correlations in node properties, especially degree-degree correlations, have been thoroughly studied in single-layer networks. Here we extend this idea to investigate and characterize correlations between the different layers of a multiplex network. Such correlations are intrinsically multiplex, and we first study them empirically by constructing and analyzing several multiplex networks from the real world. In particular, we introduce various measures to characterize correlations in the activity of the nodes and in their degree at the different layers and between activities and degrees. We show that real-world networks exhibit indeed nontrivial multiplex correlations. For instance, we find cases where two layers of the same multiplex network are positively correlated in terms of node degrees, while other two layers are negatively correlated. We then focus on constructing synthetic multiplex networks, proposing a series of models to reproduce the correlations observed empirically and/or to assess their relevance.

Effects of protocol step length on biomechanical measures in swimming.

PubMed

Barbosa, Tiago M; de Jesus, Kelly; Abraldes, J Arturo; Ribeiro, João; Figueiredo, Pedro; Vilas-Boas, João Paulo; Fernandes, Ricardo J

2015-03-01

The assessment of energetic and mechanical parameters in swimming often requires the use of an intermittent incremental protocol, whose step lengths are corner stones for the efficiency of the evaluation procedures. To analyze changes in swimming kinematics and interlimb coordination behavior in 3 variants, with different step lengths, of an intermittent incremental protocol. Twenty-two male swimmers performed n×di variants of an intermittent and incremental protocol (n≤7; d1=200 m, d2=300 m, and d3=400 m). Swimmers were videotaped in the sagittal plane for 2-dimensional kinematical analysis using a dual-media setup. Video images were digitized with a motion-capture system. Parameters that were assessed included the stroke kinematics, the segmental and anatomical landmark kinematics, and interlimb coordination. Movement efficiency was also estimated. There were no significant variations in any of the selected variables according to the step lengths. A high to very high relationship was observed between step lengths. The bias was much reduced and the 95%CI fairly tight. Since there were no meaningful differences between the 3 protocol variants, the 1 with shortest step length (ie, 200 m) should be adopted for logistical reasons.

Integrating voice evaluation: correlation between acoustic and audio-perceptual measures.

PubMed

Vaz Freitas, Susana; Melo Pestana, Pedro; Almeida, Vítor; Ferreira, Aníbal

2015-05-01

This article aims to establish correlations between acoustic and audio-perceptual measures using the GRBAS scale with respect to four different voice analysis software programs. Exploratory, transversal. A total of 90 voice records were collected and analyzed with the Dr. Speech (Tiger Electronics, Seattle, WA), Multidimensional Voice Program (Kay Elemetrics, NJ, USA), PRAAT (University of Amsterdam, The Netherlands), and Voice Studio (Seegnal, Oporto, Portugal) software programs. The acoustic measures were correlated to the audio-perceptual parameters of the GRBAS and rated by 10 experts. The predictive value of the acoustic measurements related to the audio-perceptual parameters exhibited magnitudes ranging from weak (R(2)a=0.17) to moderate (R(2)a=0.71). The parameter exhibiting the highest correlation magnitude is B (Breathiness), whereas the weaker correlation magnitudes were found to be for A (Asthenia) and S (Strain). The acoustic measures with stronger predictive values were local Shimmer, harmonics-to-noise ratio, APQ5 shimmer, and PPQ5 jitter, with different magnitudes for each one of the studied software programs. Some acoustic measures are pointed as significant predictors of GRBAS parameters, but they differ among software programs. B (Breathiness) was the parameter exhibiting the highest correlation magnitude. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Polarization-direction correlation measurement --- Experimental test of the PDCO methods

NASA Astrophysics Data System (ADS)

Starosta, K.; Morek, T.; Droste, Ch.; Rohoziński, S. G.; Srebrny, J.; Bergstrem, M.; Herskind, B.

1998-04-01

Information about spins and parities of excited states is crucial for nuclear structure studies. In ``in-beam" gamma ray spectroscopy the directional correlation (DCO) or angular distribution measurements are widely used tools for multipolarity assignment; although, it is known that neither of these methods is sensitive to electric or magnetic character of gamma radiation. Multipolarity of gamma rays may be determined when the results of the DCO analysis are combined with the results of linear polarization measurements. The large total efficiency of modern multidetector arrays allows one to carry out coincidence measurements between the polarimeter and the remaining detectors. The aim of the present study was to test experimentally the possibility of polarization-direction correlation measurements using the EUROGAM II array. The studied nucleus was ^164Yb produced in the ^138Ba(^30Si,4n) reaction at beam energies of 150 and 155 MeV. The angular correlation, linear polarization and direction-polarization correlation were measured for the strong transitions in yrast and non yrast cascades. Application of the PDCO analysis to a transition connecting a side band with the yrast band allowed one to rule out most of the ambiguities in multipolarity assignment occuring if one used angular correlations only.

Statistical measures of Planck scale signal correlations in interferometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogan, Craig J.; Kwon, Ohkyung

2015-06-22

A model-independent statistical framework is presented to interpret data from systems where the mean time derivative of positional cross correlation between world lines, a measure of spreading in a quantum geometrical wave function, is measured with a precision smaller than the Planck time. The framework provides a general way to constrain possible departures from perfect independence of classical world lines, associated with Planck scale bounds on positional information. A parametrized candidate set of possible correlation functions is shown to be consistent with the known causal structure of the classical geometry measured by an apparatus, and the holographic scaling of informationmore » suggested by gravity. Frequency-domain power spectra are derived that can be compared with interferometer data. As a result, simple projections of sensitivity for specific experimental set-ups suggests that measurements will directly yield constraints on a universal time derivative of the correlation function, and thereby confirm or rule out a class of Planck scale departures from classical geometry.« less

Direct measurement of sub-Debye-length attraction between oppositely charged surfaces.

PubMed

Kampf, Nir; Ben-Yaakov, Dan; Andelman, David; Safran, S A; Klein, Jacob

2009-09-11

Using a surface force balance with fast video analysis, we have measured directly the attractive forces between oppositely charged solid surfaces (charge densities sigma(+), sigma(-)) across water over the entire range of interaction, in particular, at surface separations D below the Debye screening length lambda(S). At very low salt concentration we find a long-ranged attraction between the surfaces (onset ca. 100 nm), whose variation at D

[The importance of handprint morphometry for determining the human body length].

PubMed

Grigor'eva, M A

2018-01-01

Handprint morphometry for the purpose of personality identification still remains a relatively novel approach. The methods employed for the measurements are not infrequently difficult to reproduce and therefore cause controversy. The objective of the present study was to introduce the system of methods for the measurement of handprints suitable for the reliable determination of the human body length. The study included the measurement of the size of 40 handprints left by124 adult subjects (52 men and 72 women). Two methods of the regression analysis, stepwise and forced inclusion, were applied to the combined group of handprints to select the equations with the high (R>0.800) coefficients of multiple correlation with the body length. 13 equations of multiple regression were obtained and analyzed. The standard error of estimating (SEE) varied from 4.30 to 5.19 cm. The best results were obtained with the equations constructed from the sizes I, II, and III of the rays without their distal phalanges. It was shown that the body length can be successfully reconstructed within the height range from 168 to 183 cm for men and from 157 to 176 cm for women. The examples of the use of the equations for the purpose of expertise of illegible and incomplete handprints are presented.

Normalized Movement Quality Measures for Therapeutic Robots Strongly Correlate With Clinical Motor Impairment Measures

PubMed Central

Celik, Ozkan; O’Malley, Marcia K.; Boake, Corwin; Levin, Harvey S.; Yozbatiran, Nuray; Reistetter, Timothy A.

2016-01-01

In this paper, we analyze the correlations between four clinical measures (Fugl–Meyer upper extremity scale, Motor Activity Log, Action Research Arm Test, and Jebsen-Taylor Hand Function Test) and four robotic measures (smoothness of movement, trajectory error, average number of target hits per minute, and mean tangential speed), used to assess motor recovery. Data were gathered as part of a hybrid robotic and traditional upper extremity rehabilitation program for nine stroke patients. Smoothness of movement and trajectory error, temporally and spatially normalized measures of movement quality defined for point-to-point movements, were found to have significant moderate to strong correlations with all four of the clinical measures. The strong correlations suggest that smoothness of movement and trajectory error may be used to compare outcomes of different rehabilitation protocols and devices effectively, provide improved resolution for tracking patient progress compared to only pre-and post-treatment measurements, enable accurate adaptation of therapy based on patient progress, and deliver immediate and useful feedback to the patient and therapist. PMID:20388607

ATLAS: An advanced PCR-method for routine visualization of telomere length in Saccharomyces cerevisiae.

PubMed

Zubko, Elena I; Shackleton, Jennifer L; Zubko, Mikhajlo K

2016-12-01

Measuring telomere length is essential in telomere biology. Southern blot hybridization is the predominant method for measuring telomere length in the genetic model Saccharomyces cerevisiae. We have further developed and refined a telomere PCR approach, which was rarely used previously (mainly in specific telomeric projects), into a robust method allowing direct visualisation of telomere length differences in routine experiments with S. cerevisiae, and showing a strong correlation of results with data obtained by Southern blot hybridization. In this expanded method denoted as ATLAS (A-dvanced T-elomere L-ength A-nalysis in S. cerevisiae), we have introduced: 1) set of new primers annealing with high specificity to telomeric regions on five different chromosomes; 2) new approach for designing reverse telomere primers that is based on the ligation of an adaptor of a fixed size to telomeric ends. ATLAS can be used at the scale of individual assays and high-throughput approaches. This simple, time/cost-effective and reproducible methodology will complement Southern blot hybridization and facilitate further progress in telomere research. Copyright © 2016 Elsevier B.V. All rights reserved.

Measuring Two-Event Structural Correlations on Graphs

DTIC Science & Technology

2012-08-01

2012 to 00-00-2012 4. TITLE AND SUBTITLE Measuring Two-Event Structural Correlations on Graphs 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ...by event simulation on the DBLP graph. Then we examine the efficiency and scala - bility of the framework with a Twitter network. The third part of...correlation pattern mining for large graphs. In Proc. of the 8th Workshop on Mining and Learning with Graphs, pages 119–126, 2010. [23] T. Smith. A

Simultaneous water vapor and dry air optical path length measurements and compensation with the large binocular telescope interferometer

NASA Astrophysics Data System (ADS)

Defrère, D.; Hinz, P.; Downey, E.; Böhm, M.; Danchi, W. C.; Durney, O.; Ertel, S.; Hill, J. M.; Hoffmann, W. F.; Mennesson, B.; Millan-Gabet, R.; Montoya, M.; Pott, J.-U.; Skemer, A.; Spalding, E.; Stone, J.; Vaz, A.

2016-08-01

The Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 microns). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI/MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illustrate the feasibility of our feedforward approach to stabilize the path length fluctuations seen by the LBTI nuller.

Subfoveal Choroidal Thickness and Axial Length in Preschool Children with Hyperopic Anisometropic Amblyopia.