scholarly journals Overall Bone Structure as Assessed by Slice-by-Slice Profile

2019 ◽  
Vol 46 (4) ◽  
pp. 343-348 ◽  
Author(s):  
Eli Amson

Abstract Quantifying the inner structure of bones is central to various analyses dealing with the phenotypic evolution of animals with an ossified skeleton. Computed tomography allows to assess the repartition of bone tissue within an entire skeletal element. Two parameters of importance for such analyses are the global compactness (Cg) and total cross-sectional area (Tt.Ar). However, no open-source, time-efficient methods are available to acquire these parameters for whole bones. A methodology to assess the variation of these parameters along a profile following one of the studied bone’s anatomical axes is also wanting. Here I present an ImageJ macro and associated R script to automatically acquire Cg and Tt.Ar along an axis of the skeletal element of interest using a slice-by-slice approach. No manual segmentation is required and several bones can be present on the analysed scan, as long as the bone of interest is isolated and the largest element on each slice. While some bias might be involved by the automatic acquisition, semi-automatic slice exclusion and correction procedures can be used to efficiently account for it. As a test case, µCT-data was gathered for the mid-lumbar vertebra of over 70 mammals. The two evaluated correction procedures proved to perform equally well, with a slight advantage for the one relying on the exclusion of local outliers. The presented macro allows to efficiently build a dataset concerned with the quantification of bone inner structure. The code being readily available, further improvement of the methodology and adjustment to particular needs can be easily performed.

2014 ◽  
Vol 22 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Mikołaj Knaflewski ◽  
Alina Kałużewicz ◽  
Wenjing Chen ◽  
Anna Zaworska ◽  
Włodzimierz Krzesiński

AbstractGreen spear yield of 16 asparagus cultivars originating from six countries was assessed from 2011 to 2013. There were considerable differences in total, marketable and early yields between the cultivars. The quality of harvested spears also varied remarkably. On average, the highest mean total and marketable yields from 3 years of investigation came from Dutch cultivars ‘Gijnlim’ and ‘Cumulus’ and German cv. ‘Mondeo’. The lowest yields were found in New Zealand cultivars ‘Pacific Challenger’ and ‘Pacific 2000’. The greatest mean marketable spear weight was recorded for ‘Cumulus’, whereas the smallest spear weight was obtained from ‘Pacific 2000’, ‘H666’ and ‘NJ 953’. Cultivars ‘Gijnlim’, ‘Cumulus’ and ‘Mondeo’ produced the highest early yields, while ‘Pacific 2000’ and ‘Pacific Challenger’ produced the lowest. In order to determine the dependence between summer stalks size of tested cultivars in the preceding year and their yields in the following year, regression equations and their correlation coefficients were estimated. The size of summer stalks was expressed as plant growth index, which was the multiplication of height and total cross-sectional area of summer stalks. There was a significant and positive correlation between plant growth index of tested cultivars and their yields in the next vegetation period. The correlation coefficients between these two parameters amounted to 0.62 and 0.68 in 2011/2012 and 2012/2013, respectively


2010 ◽  
Vol 26 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Marc Vierhaus ◽  
Arnold Lohaus ◽  
Indra Shah

This investigation focuses on the question whether assessments of the development of internalizing behavior from childhood to adolescence are affected by the kind of research design (longitudinal versus cross-sectional). Two longitudinal samples of 432 second-graders and 366 fourth graders participated in a longitudinal study with subsequent measurements taken 1, 2, and 3 years later. A third sample consisting of 849 children covering the same range of grades participated in a cross-sectional study. The results show that the development of internalizing symptoms in girls – but not in boys – varies systematically with the research design. In girls, there is a decrease of internalizing symptoms (especially between the first two timepoints) in the longitudinal assessment, which may reflect, for example, the influence of strain during the first testing situation. Both longitudinal trajectories converge to a common trajectory from grade 2 to grade 7 when controlling for this “novelty-distress effect.” Moreover, when we control this effect, the slight but significant decrease characterizing the common trajectory becomes similar to the one obtained in the cross-sectional study. Therefore, trajectories based on longitudinal assessments may suggest more changes with regard to internalizing symptoms over time than actually take place, while trajectories based on cross-sectional data may be characterized by an increased level of internalizing symptoms. Theoretical and practical implications of these results are discussed.


2005 ◽  
Vol 2 (2) ◽  
pp. 79
Author(s):  
Mohd Khairul Mohd Salleh ◽  
Mohamad Syukri Suhaili ◽  
Zuhani Ismail ◽  
Zaiki Awang

A simple design of a metallic circular cross-sectional air-filled cavity is presented. Two probes of varied lengths are used to excite TE112-mode wave into the cavity to give a resonant frequency of 5.86 GHz. The experiments show that the resonant frequency of the cavity resonator decreases as the lengths of the probes are increased. The shortest probe in the range of study gives the closest resonant frequency to the one desired.


Author(s):  
Jong Hak Lee ◽  
Jong Eun Kim ◽  
Chang Su Park ◽  
Nam Il Kim ◽  
Jang Won Moon ◽  
...  

Abstract In this work, a slightly unetched gate hard mask failure was analyzed by nano probing. Although unetched hard mask failures are commonly detected from the cross sectional view with FIB or FIB-TEM and planar view with the voltage contrast, in this case of the very slightly unetched hard mask, it was difficult to find the defects within the failed area by physical analysis methods. FIB is useful due to its function of milling and checking from the one region to another region within the suspected area, but the defect, located under contact was very tiny. So, it could not be detected in the tilted-view of the FIB. However, the state of the failure could be understood from the electrical analysis using a nano probe due to its ability to probe contact nodes across the fail area. Among the transistors in the fail area, one transistor’s characteristics showed higher leakage current and lower ON current than expected. After physical analysis, slightly remained hard mask was detected by TEM. Chemical processing was followed to determine the gate electrode (WSi2) connection to tungsten contact. It was also proven that when gate is floated, more leakage current flows compared to the state that the zero voltage is applied to the gate. This was not verified by circuit simulation due to the floating nodes.


Author(s):  
Ruoliang Tang ◽  
Jay M. Kapellusch ◽  
Andrew S. Merryweather ◽  
Matthew S. Thiese ◽  
Kurt T. Hegmann ◽  
...  

Low back pain (LBP) is a common health problem and a major cause of lost productivity in workplaces. Manual materials handling (MMH) jobs have traditionally been regarded as risk factor for LBP. Compared to two-handed lifting, one-handed lifting has received little attention in both epidemiological and biomechanical research. In addition, one frequent complaint of the revised NIOSH lifting equation (RNLE) has been the lack of capability to directly evaluate one-handed lifting. Modifications have been proposed by the European Union, however their efficacy and influence have not yet been evaluated. This cross-sectional study provided objective survey of the MMH jobs, especially the one-handed lifting performed in manufacturing industry and investigated the outcomes of three proposed methods to address one-handed lifting using RNLE approach. Preliminary results suggest that workers with some one-handed lifting are associated with higher physical exposure. However, the increase was more significant among those who perform primarily one-handed lifting.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Olga-Cecilia Vargas-Pinilla ◽  
Eliana-Isabel Rodríguez-Grande

AbstractThe protocol established for taking hand grip dynamometry measurements determines that the patient must be in a sitting position. This protocol cannot be applied due to the patient’s conditions in some cases, such as abdominal surgery, musculoskeletal spine or hip injuries. The purpose was to determine the reproducibility and level of agreement between the Handgrip dynamometry in supine position with the elbow flexed or extended, and the one measured in the sitting position, the design was a descriptive cross-sectional study. The population were young apparently healthy between 18 and 30 years of age (N = 201). Handgrip measurement was performed on both upper limbs in a sitting position with a flexed elbow, a supine position with a flexed elbow, and supine position with the elbow extended. Reproducibility was nearly perfect in all positions (ICC 0.95–0.97). Regarding the level of agreement for the comparison between sitting and supine positions with a flexed elbow, an average difference of − 0.406. For supine position with an extended elbow and supine position with a flexed elbow, the average difference was − 1.479. Considering the results, clinicians or researchers can choose any of the positions evaluated herein and obtain reliable results as long as the standardization process is followed.


2021 ◽  
Vol 9 (1) ◽  
pp. 88
Author(s):  
Marco Petti ◽  
Sara Pascolo ◽  
Silvia Bosa ◽  
Nadia Busetto

The prism of the Lignano tidal inlet was approximately constant over the last forty years, although the section width has halved. This has led to questions concerning the factors that most influence the tidal prism, and on the applicability of the well-known A–P relationship. A conceptual scheme of the sea–channel–lagoon system has been used to perform a sensitivity analysis of different parameters that characterize both the basin and the inlet cross-section. A 2D hydrodynamic model has been applied to evaluate the prism and compare it to the one derived by a static method, which is the basis of the analytical derivation of the A–P linkage. Three regimes have been found in the prism variability as a function of the basin extension: a linear static regime between prism and basin area; an asymptotic regime in which the prism depends only on the basin bottom friction; and an intermediate one. In addition, the roles of the inlet and channel sizes on the prism value have been investigated. The results, compared to the empirical relationships between the prism and the inlet cross-section, show that a variation in the cross-sectional area does not always corresponds to a change in tidal prism.


1984 ◽  
Vol 5 ◽  
pp. 95-99 ◽  
Author(s):  
B. J. McInnes ◽  
W. F. Budd

The dynamic state of the West Antarctic ice sheet has been termed the grand problem of glaciology. An attempt is presented to assess it by simulating the observed ice thickness and ice velocities along a cross-section from ice stream B (Ross Sea) to Pine Island Glacier (Pine Island Bay) with a numerical model developed from the one described by Budd and McInnes (1978). A kinematic analysis with topographical and regime data from various sources shows the mass fluxes observed near the grounding line of the Ross Ice Shelf to be of the order expected for steady-state balance. Deformation of the ice accounts for only a small fraction of the observed flow there. Simulations (to be described in detail elsewhere) with the Budd/McInnes surging mechanism can approximate the existing ice thickness as a post-surge feature but fail to reproduce the high balance velocities. Both these velocities and the existing ice-thickness profile are simulated successfully as a state of steady sliding, with parameterizations involving the ice thickness above that corresponding to buoyancy and realistically assumed longitudinal strain-rates. A range of results is presented to illustrate the sensitivity of the simulation to changes in various parameters.


Galaxies ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 55 ◽  
Author(s):  
Rajendra P. Gupta

We have developed a cosmological model by allowing the speed of light c, gravitational constant G and cosmological constant Λ in the Einstein filed equation to vary in time, and solved them for Robertson-Walker metric. Assuming the universe is flat and matter dominant at present, we obtain a simple model that can fit the supernovae 1a data with a single parameter almost as well as the standard ΛCDM model with two parameters, and which has the predictive capability superior to the latter. The model, together with the null results for the variation of G from the analysis of lunar laser ranging data determines that at the current time G and c both increase as dG/dt = 5.4GH0 and dc/dt = 1.8cH0 with H0 as the Hubble constant, and Λ decreases as dΛ/dt = −1.2ΛH0. This variation of G and c is all what is needed to account for the Pioneer anomaly, the anomalous secular increase of the moon eccentricity, and the anomalous secular increase of the astronomical unit. We also show that the Planck’s constant ħ increases as dħ/dt = 1.8ħH0 and the ratio D of any Hubble unit to the corresponding Planck unit increases as dD/dt = 1.5DH0. We have shown that it is essential to consider the variation of all the physical constants that may be involved directly or indirectly in a measurement rather than only the one whose variation is of interest.


2016 ◽  
Vol 23 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Dunja Perić ◽  
Paul A. Bartley ◽  
Lawrence Davis ◽  
Ali Ulvi Uzer ◽  
Cahit Gürer

AbstractLignin is a coproduct of biofuel and paper industries, which exhibits binding qualities when mixed with water. Lignin is an ideal candidate for a sustainable stabilization of unpaved roads. To this end, an experimental program was devised and carried out to quantify effects of lignin on compaction and early age shear strength behaviors of sand. Samples were prepared by mixing a particular type of coproduct called calcium lignosulfonate (CaL) with sand and water. Based on the extensive analyses of six series of strength tests, it was found that a normalized cohesion increased with an increasing normalized areas ratio. Normalizations were carried out by dividing the cohesion and area ratio by gravimetric CaL content whereby the area ratio was obtained by dividing the portion of the cross-sectional area occupied with lignosulfonate-water (CaL-W) paste by the total cross-sectional area. While the increase in the normalized cohesion eventually leveled out, the cohesion peaked at 6% of CaL. Thus, sand-CaL-water (S-CaL-W) mixes sustained larger shear stresses than dry sand for a range of normal stresses below the limiting normal stress. Consequently, the early age behavior indicates that adding CaL-W to sand is clearly beneficial in the near-surface applications in dry sand.


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