scholarly journals Influence of Load and Phase of Contraction on Lateral Symmetries in Flywheel Squats

Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 111
Author(s):  
Darjan Smajla ◽  
Darjan Spudić ◽  
Nejc Šarabon
Keyword(s):  
Sample Size ◽  
Reference Point ◽  
Peak Force ◽  
Lower Limbs ◽  
Large Sample Size ◽  
Physically Active ◽  
Wide Range ◽  
Left And Right ◽  
The Mean ◽  
Functional Movements

Assessment of lateral symmetries (LS) of lower limbs has been widely investigated. However, there are no studies about LS during exposure to high eccentric and concentric loads during flywheel (FW) squats. A total of 422 young, physically active participants performed squats on an FW device with different equidistant loads (0.05, 0.125 and 0.2 kg∙m2). The mean and peak force of the left and right leg were assessed for the concentric and eccentric contaction phase. LS values were calculated for each load and phase of squat. Our results showed that the absolute mean and peak force of the concentric and eccentric phase of contraction had excellent reliability, while LS values were more reliable when eccentric force was used for their calculation. Mean and peak forces were increased with the higher FW load. In general, we found a decrease in LS values in the concentric phase of contraction with the higher load. Moreover, values of LS are similar to a wide range of other functional movements. Nevertheless, symmetrical force application during squatting on a FW device should be satisfied regardless of the FW load. Due to the large sample size, our results are valuable as a reference point when athletes are evaluated during training.

Walking on five legs: investigating tail use during slow gait in kangaroos and wallabies

2015 ◽  
Vol 63 (3) ◽  
pp. 192 ◽  
Author(s):  
Rebekah S. Dawson ◽  
Natalie M. Warburton ◽  
Hazel L. Richards ◽  
Nick Milne
Keyword(s):  
Comparative Analysis ◽  
Swing Phase ◽  
Lower Limbs ◽  
Relative Movement ◽  
Joint Angles ◽  
Video Recordings ◽  
Constant Height ◽  
Wide Range ◽  
The Mean ◽  
Tail Use

Pentapedal locomotion is the use of the tail as a fifth leg during the slow gait of kangaroos. Although previous studies have informally noted that some smaller species of macropodines do not engage in pentapedal locomotion, a systematic comparative analysis of tail use during slow gait across a wide range of species in this group has not been done. Analysis of relative movement of the pelvis, tail, and joint angles of the lower limbs during slow gait, using 2D landmark techniques on video recordings, was carried out on 16 species of Macropodinae. We also compared the relative lengthening of the tibia using crural index (CI) to test whether hindlimb morphology was associated with pentapedal locomotion. Pentapedal locomotion was characterised by three features: the presence of the ‘tail repositioning phase’, the constant height of the pelvis and the stationary placement of the distal tail on the ground during the hindlimb swing phase. The mean CI of pentapedal species was significantly greater than that of non-pentapedal species (1.71 versus 1.36; P < 0.001). This lends support to the hypothesis that the use of pentapedal locomotion is associated with the relative lengthening of the hindlimb, which in turn is associated with body size and habitat preference within the Macropodinae.

KG²B, a world-wide inter-laboratory benchmark of low permeability measurement and modelling

2020 ◽  
Author(s):  
Christian David
Keyword(s):  
Sample Size ◽  
Gas Permeability ◽  
Good Practice ◽  
Pore Fluid ◽  
Low Permeability ◽  
Unexpected Result ◽  
Experimental Conditions ◽  
Blind Test ◽  
Wide Range ◽  
The Mean

&lt;p&gt;A benchmark of low permeability measurements has been organized by the Geosciences and Environment Laboratory at University Cergy-Pontoise over the period 2015-2018. The objective of this benchmark was to measure or estimate through modelling the permeability of a single material, selected for its low permeability. A wide range of different approaches were covered, classified into (i) direct measurement methods, including steady-state, transient pulse and oscillatory techniques and (ii) models using microstructural data obtained from imaging or porosimetry techniques. At the beginning, 30 laboratories in 8 different countries volunteered to participate, and at the end results from 24 labs were collected which is remarkable.&lt;/p&gt;&lt;p&gt;The selected rock was the Grimsel granodiorite (Switzerland), so the benchmark was called &amp;#8220;KG&amp;#178;B&amp;#8221;, which means &amp;#8220;K for Grimsel Granodiorite Benchmark&amp;#8221;. Two fresh cores with diameter 85 mm and about one meter long each were provided by colleagues from ETH Z&amp;#252;rich. The cores were drilled in the Swiss Grimsel test site, an underground research laboratory in hard rock, at a distance between 4 and 6 meters from the tunnel, away from the EDZ. The cores were cut into small pieces (between 2 and 10 cm long) and sent to the participants. The porosity of the Grimsel Granodiorite is less than 1%, and the permeability is in the 10&lt;sup&gt;-18&lt;/sup&gt; m&amp;#178; range.&lt;/p&gt;&lt;p&gt;The expected outcomes of the benchmark were: (i) to compare the results for each method separately and (ii) between the different methods/models, (iii) to assess the precision of each method, (iv) to study the influence of experimental conditions, especially sample size and the nature of pore fluid, (v) to gather information on the know-how in each laboratory, and finally (vi) to suggest good practice for low permeability measurements.&lt;/p&gt;&lt;p&gt;The benchmark was designed as a blind test, i.e. the results from each lab were not known by the other labs except for the organizers. A dedicated website [1] was constantly updated to allow the participants to follow the progression of the benchmark. It took about three years to manage the benchmark, collect all the data, complete the dataset analysis and publish the results [2,3]. The results collected allowed us to discuss the influence of pore-fluid, measurement method, sample size and pressure sensitivity, as well as the relevance of various models for permeability estimation. The most striking and unexpected result was that regardless of the method used, the mean gas permeability was higher than the mean liquid permeability by a factor approximately 2.&lt;/p&gt;&lt;p&gt;As an introduction to the session, our aim is to show how conducting such a benchmarking exercise can help to answer the questions raised by the session: - How repeatable are permeability measurements, and how dependent are they on the apparatuses and methods? - Which experimental pitfalls exist, what are the underlying assumptions and how might they impact permeability? - Can we define standard experimental procedures to improve permeability measurements in low permeability materials?&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;ul&gt;&lt;li&gt;[1] https://labo.u-cergy.fr/~kg2b&lt;/li&gt; &lt;li&gt;[2] &lt;em&gt;Geophys. J. Int.&lt;/em&gt;, 215, 799-824, doi: 10.1093/gji/ggy304, 2018.&lt;/li&gt; &lt;li&gt;[3] &lt;em&gt;Geophys. J. Int.&lt;/em&gt;, 215, 825-843, doi: 10.1093/gji/ggy305, 2018.&lt;/li&gt; &lt;/ul&gt;

scholarly journals Discriminating Between Second-Order Model With/Without Interaction Base on Central Tendency Estimation

2021 ◽  
Vol 4 (3) ◽  
pp. 47-63
Author(s):  
Owhondah P.S. ◽  
Enegesele D. ◽  
Biu O.E. ◽  
Wokoma D.S.A.
Keyword(s):  
Regression Model ◽  
Sample Size ◽  
Large Data ◽  
Second Order ◽  
Data Sets ◽  
Large Sample Size ◽  
Order Model ◽  
Data Set ◽  
The Mean ◽  
Better Than

The study deals with discriminating between the second-order models with/without interaction on central tendency estimation using the ordinary least square (OLS) method for the estimation of the model parameters. The paper considered two different sets of data (small and large) sample size. The small sample size used data of unemployment rate as a response, inflation rate and exchange rate as the predictors from 2007 to 2018 and the large sample size was data of flow-rate on hydrate formation for Niger Delta deep offshore field. The〖 R〗^2, AIC, SBC, and SSE were computed for both data sets to test for adequacy of the models. The results show that all three models are similar for smaller data set while for large data set the second-order model centered on the median with/without interaction is the best base on the number of significant parameters. The model’s selection criterion values (R^2, AIC, SBC, and SSE) were found to be equal for models centered on median and mode for both large and small data sets. However, the model centered on median and mode with/without interaction were better than the model centered on the mean for large data sets. This study shows that the second-order regression model centered on median and mode are better than the model centered on the mean for large data set, while they are similar for smaller data set. Hence, the second-order regression model centered on median and mode with or without interaction are better than the second-order regression model centered on the mean.

scholarly journals Optimum sample size to estimate mean parasite abundance in fish parasite surveys

2018 ◽  
Vol 55 (1) ◽  
pp. 52-59 ◽  
Author(s):  
S. Shvydka ◽  
V. Sarabeev ◽  
V. D. Estruch ◽  
C. Cadarso-Suárez
Keyword(s):  
Sample Size ◽  
Sample Size Determination ◽  
Superior Performance ◽  
Size Determination ◽  
Optimum Sample Size ◽  
True Value ◽  
Wide Range ◽  
Precision Level ◽  
The Mean ◽  
Optimum Sample

Summary To reach ethically and scientifically valid mean abundance values in parasitological and epidemiological studies this paper considers analytic and simulation approaches for sample size determination. The sample size estimation was carried out by applying mathematical formula with predetermined precision level and parameter of the negative binomial distribution estimated from the empirical data. A simulation approach to optimum sample size determination aimed at the estimation of true value of the mean abundance and its confidence interval (CI) was based on the Bag of Little Bootstraps (BLB). The abundance of two species of monogenean parasites Ligophorus cephali and L. mediterraneus from Mugil cephalus across the Azov-Black Seas localities were subjected to the analysis. The dispersion pattern of both helminth species could be characterized as a highly aggregated distribution with the variance being substantially larger than the mean abundance. The holistic approach applied here offers a wide range of appropriate methods in searching for the optimum sample size and the understanding about the expected precision level of the mean. Given the superior performance of the BLB relative to formulae with its few assumptions, the bootstrap procedure is the preferred method. Two important assessments were performed in the present study: i) based on CIs width a reasonable precision level for the mean abundance in parasitological surveys of Ligophorus spp. could be chosen between 0.8 and 0.5 with 1.6 and 1x mean of the CIs width, and ii) the sample size equal 80 or more host individuals allows accurate and precise estimation of mean abundance. Meanwhile for the host sample size in range between 25 and 40 individuals, the median estimates showed minimal bias but the sampling distribution skewed to the low values; a sample size of 10 host individuals yielded to unreliable estimates.

scholarly journals Comparing interannual variability in three regional single-model initial-condition large ensembles (SMILEs) over Europe

2020 ◽  
Vol 11 (4) ◽  
pp. 1013-1031
Author(s):  
Fabian von Trentini ◽  
Emma E. Aalbers ◽  
Erich M. Fischer ◽  
Ralf Ludwig
Keyword(s):  
Sample Size ◽  
Interannual Variability ◽  
Climate Models ◽  
Heat Waves ◽  
Large Sample Size ◽  
Initial Condition ◽  
Single Model ◽  
Data Set ◽  
Large Ensembles ◽  
The Mean

Abstract. For sectors like agriculture, hydrology and ecology, increasing interannual variability (IAV) can have larger impacts than changes in the mean state, whereas decreasing IAV in winter implies that the coldest seasons warm more than the mean. IAV is difficult to reliably quantify in single realizations of climate (observations and single-model realizations) as they are too short, and represent a combination of external forcing and IAV. Single-model initial-condition large ensembles (SMILEs) are powerful tools to overcome this problem, as they provide many realizations of past and future climate and thus a larger sample size to robustly evaluate and quantify changes in IAV. We use three SMILE-based regional climate models (CanESM-CRCM, ECEARTH-RACMO and CESM-CCLM) to investigate downscaled changes in IAV of summer and winter temperature and precipitation, the number of heat waves, and the maximum length of dry periods over Europe. An evaluation against the observational data set E-OBS reveals that all models reproduce observational IAV reasonably well, although both under- and overestimation of observational IAV occur in all models in a few cases. We further demonstrate that SMILEs are essential to robustly quantify changes in IAV since some individual realizations show significant IAV changes, whereas others do not. Thus, a large sample size, i.e., information from all members of SMILEs, is needed to robustly quantify the significance of IAV changes. Projected IAV changes in temperature over Europe are in line with existing literature: increasing variability in summer and stable to decreasing variability in winter. Here, we further show that summer and winter precipitation, as well as the two summer extreme indicators mostly also show these seasonal changes.

scholarly journals Varo y valgo de rodilla en cambios de dirección como factor de riesgo de lesión (Knee varus and valgus in sidecutting as injury risk factor)

Retos ◽  
2015 ◽  
pp. 176-177
Author(s):  
Adrián Feria Madueño ◽  
Moises De Hoyo Lora ◽  
Sergio Romero Boza ◽  
Jesús Mateo Cortés ◽  
Borja Sañudo Corrales
Keyword(s):  
Lower Limb ◽  
Injury Risk ◽  
Knee Injuries ◽  
Peak Force ◽  
Varus Knee ◽  
Transverse Axis ◽  
Physically Active ◽  
Valgus Angle ◽  
Injury Risk Factor ◽  
The Mean

La fuerza parcial soportada por los miembros inferiores en un eje transversal durante cambios de dirección parece ser determinante para la aparición de lesiones de rodilla. El objetivo de este estudio es conocer el genu varo y valgo soportado por la articulación durante cambios de dirección en sujetos físicamente activos. Cincuenta y seis sujetos participaron de manera voluntaria en el estudio (24.26 ± 2.3 años; altura = 1.79 ± 0.07 m; peso = 75.48 ± 13.71 kg; IMC = 24.16 ± 3.28 kg·m-2). Llevaron a cabo 3 cambios de dirección diferentes: 30º, 45º y 45º al mismo lado (45ml) de su pie dominante (cambio cerrado). Nuestros resultados nos indican que tanto la fuerza en valgo como en varo fue mayor en cambios a 30º (Valgo: 37.57 N SD±45.73; Varo: 721.92 N SD±250.52) respecto a cambios de 45º (Valgo: 27.89 N SD±50,92; Varo: 696.42 N SD±252,70), aunque estas diferencias no fueron estadísticamente significativas (p>0.05). En cuanto a los cambios cerrados, la fuerza media en valgo fue de 1890,01 N (SD±94,18). El valgo en cambios cerrados fue también mayor respecto al valgo en 30º como al valgo en 45º, aunque no significativamente (p=0.07). Por otro lado, los cambios cerrados producen una fuerza también mayor en valgo que en cambios abiertos (45º y 30º). Estudios posteriores deberían analizar el ángulo de varo y valgo en el cambio de dirección para relacionarlo con los niveles de fuerza ejercidos en ese eje.Palabras clave: valgo, varo, rodilla, cambios de dirección, riesgo de lesión.Abstract: The peak force of lower limb in transverse axis during sidecutting may determinate the develop of knee injuries. The aim of this study was to know the valgus and varus of the knee joint during sidecutting in physically active people. Fifty-six physically active people participated in the study voluntarily (24.26 ± 2.3 years; height = 1.79 ± 0.07 m; weight = 75.48 ± 13.71 kg; BMI = 24.16 ± 3.28 kg·m-2). They made three different sidecuttings: 30º, 45º and 45º in the same way (45 ml) from their dominant foot (closed sidecutting). Our results indicate that the peak force in valgus and varus was bigger in 30º sidecuttings (Valgus: 37.57 N SD±45.73; Varus: 721.92 N SD±250.52) than 45º sidecuttings (Valgus: 27.89 N SD±50,92; Varus: 696.42 N SD±252,70), although these differences were not statistically significant (p>0,05). In the closed sidecuttings, the mean force in valgus was 1890,01 N (SD±94,18). The valgus in closing sidecuttings was bigger than valgus in 30º and 45º sidecuttings too, although not statistically significant (p=0,07). On the other hand, closed sidecuttings produce a peak force bigger in valgus than open sidecuttings (30º and 45º). Subsequent studies must analyze the varus and valgus angle in the sidecutting to be compared with peak force in this axis. Key words: valgus, varus, knee, sidecutting, injury risk.

A Comparison of Physiological Demand between Self-Propelled and Motorized Treadmill Exercise

2018 ◽  
Vol 7 (4) ◽  
pp. 13-21
Author(s):  
Todd Backes ◽  
Charlene Takacs
Keyword(s):  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
Cardiopulmonary Exercise Testing ◽  
Mean Value ◽  
The Self ◽  
Mixing Chamber ◽  
Wide Range ◽  
The Subject ◽  
The Mean ◽  
Computer Controlled

There are a wide range of options for individuals to choose from in order to engage in aerobic exercise; from outdoor running to computer controlled and self-propelled treadmills. Recently, self-propelled treadmills have increased in popularity and provide an alternative to a motorized treadmill. Twenty subjects (10 men, 10 women) ranging in age from 19-23 with a mean of 20.4 ± 0.8 SD were participants in this study. The subjects visited the laboratory on three occasions. The purpose of the first visit was to familiarize the subject with the self-propelled treadmill (Woodway Curve 3.0). The second visit, subjects were instructed to run on the self-propelled treadmill for 3km at a self-determined pace. Speed data were collected directly from the self-propelled treadmill. The third visit used speed data collected during the self-propelled treadmill run to create an identically paced 3km run for the subjects to perform on a motorized treadmill (COSMED T150). During both the second and third visit, oxygen consumption (VO2) and respiratory exchange ratio (R) data were collected with COSMED’s Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system. The VO2 mean value for the self-propelled treadmill (44.90 ± 1.65 SE ml/kg/min) was significantly greater than the motorized treadmill (34.38 ± 1.39 SE ml/kg/min). The mean R value for the self-propelled treadmill (0.91 ± 0.01 SE) was significantly greater than the motorized treadmill (0.86 ± 0.01 SE). Our study demonstrated that a 3km run on a self-propelled treadmill does elicit a greater physiological response than a 3km run at on a standard motorized treadmill. Self-propelled treadmills provide a mode of exercise that offers increased training loads and should be considered as an alternative to motorized treadmills.

The way of value of Correlation of genomic DNA microsatellite loci and live weight of Chukchi reindeer

2020 ◽  
pp. 27-32
Author(s):  
V. Dodokhov ◽  
N. Pavlova ◽  
T. Rumyantseva ◽  
L. Kalashnikova
Keyword(s):  
Microsatellite Markers ◽  
Agricultural Production ◽  
Live Weight ◽  
Biodiversity Loss ◽  
Tribal Community ◽  
High Germination ◽  
Wide Range ◽  
The Mean ◽  
High Level ◽  
Dna Microsatellite

The article presents the genetic characteristic of the Chukchi reindeer breed. The object of the study was of the Chukchi reindeer. In recent years, the number of reindeer of the Chukchi breed has declined sharply. Reduced reindeer numbers could lead to biodiversity loss. The Chukchi breed of deer has good meat qualities, has high germination viability and is adapted in adverse tundra conditions of Yakutia. Herding of the Chukchi breed of deer in Yakutia are engaged only in the Nizhnekolymsky district. There are four generic communities and the largest of which is the agricultural production cooperative of nomadic tribal community «Turvaurgin», which was chosen to assess the genetic processes of breed using microsatellite markers: Rt6, BMS1788, Rt 30, Rt1, Rt9, FCB193, Rt7, BMS745, C 143, Rt24, OheQ, C217, C32, NVHRT16, T40, C276. It was found that microsatellite markers have a wide range of alleles and generally have a high informative value for identifying of genetic differences between animals and groups of animal. The number of identified alleles is one of the indicators of the genetic diversity of the population. The total number of detected alleles was 127. The Chukchi breed of deer is characterized by a high level of heterozygosity, and the random crossing system prevails over inbreeding in the population. On average, there were 7.9 alleles (Na) per locus, and the mean number of effective alleles (Ne) was 4.1. The index of fixation averaged 0.001. The polymorphism index (PIC) ranged from 0.217 to 0.946, with an average of 0.695.

Celiac Disease in Kosovar Albanian Children: Evaluation of Clinical Features and Diagnosis

2020 ◽  
Vol 16 (3) ◽  
pp. 241-247
Author(s):  
Atifete Ramosaj-Morina ◽  
Alije Keka-Sylaj ◽  
Arbana Baloku Zejnullahu ◽  
Lidvana Spahiu ◽  
Virgjina Hasbahta ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Disease Onset ◽  
Clinical Manifestations ◽  
Gastrointestinal Symptoms ◽  
Dominant Mode ◽  
Primary School Children ◽  
Cross Sectional ◽  
Classical Form ◽  
Wide Range ◽  
The Mean

Background: Celiac disease is an immune-mediated disorder characterized by variable clinical manifestations, specific antibodies, HLA-DQ2/DQ8 haplotypes, and enteropathy. Objectives: The aim of this study was to present the clinical spectrum and patterns of celiac disease in Kosovar Albanian children. Methods: A cross-sectional retrospective study was performed with Albanian children aged 0-18 years, treated for celiac disease in the Pediatric Clinic, University Clinical Center of Kosovo from 2005 to 2016. Results: During the study period, 63 children were treated for celiac disease. The mean age at diagnosis was 5.5 years (SD ± 3.31). The mean age at celiac disease onset was 3.3 years (SD ± 2.02), while the mean delay from the first symptoms indicative of celiac disease to diagnosis was 2.2 years (SD ± 2.09). More than 70% of the patients were diagnosed in the first 7 years of life, mainly presented with gastrointestinal symptoms, while primary school children and adolescents mostly showed atypical symptoms (p<0.001). The classical form of celiac disease occurred in 78% of the cases. Sixty (95%) patients carried HLA-DQ2.5, DQ2.2 and/or HLA-DQ8 heterodimers, and only three of them tested negative. Conclusions: Kosovo, as the majority of developing countries, is still facing the classical form of celiac disease as the dominant mode of presentation; as a result, most children with other forms of the celiac disease remain undiagnosed. : Physicians should be aware of the wide range of clinical presentations and utilize low testing thresholds in order to prevent potential long-term problems associated with untreated celiac disease.

scholarly journals Planetary Nebulae in M31: Abundances, and comparison with bright Planetary Nebulae in the LMC

1997 ◽  
Vol 180 ◽  
pp. 475-476
Author(s):  
M. G. Richer ◽  
G. Stasińska ◽  
M. L. McCall
Keyword(s):  
Planetary Nebula ◽  
Luminosity Function ◽  
Large Population ◽  
Wavelength Region ◽  
Planetary Nebulae ◽  
Surprising Result ◽  
Population Synthesis ◽  
Abundance Distribution ◽  
Wide Range ◽  
The Mean

We have obtained spectra of 28 planetary nebulae in the bulge of M31 using the MOS spectrograph at the Canada-France-Hawaii Telescope. Typically, we observed the [O II] λ3727 to He I λ5876 wavelength region at a resolution of approximately 1.6 å/pixel. For 19 of the 21 planetary nebulae whose [OIII]λ5007 luminosities are within 1 mag of the peak of the planetary nebula luminosity function, our oxygen abundances are based upon a measured [OIII]λ4363 intensity, so they are based upon a measured electron temperature. The oxygen abundances cover a wide range, 7.85 dex < 12 + log(O/H) < 9.09 dex, but the mean abundance is surprisingly low, 12 + log(O/H)–8.64 ± 0.32 dex, i.e., roughly half the solar value (Anders & Grevesse 1989). The distribution of oxygen abundances is shown in Figure 1, where the ordinate indicates the number of planetary nebulae with abundances within ±0.1 dex of any point on the x-axis. The dashed line indicates the mean abundance, and the dotted lines indicate the ±1 σ points. The shape of this abundance distribution seems to indicate that the bulge of M31 does not contain a large population of bright, oxygen-rich planetary nebulae. This is a surprising result, for various population synthesis studies (e.g., Bica et al. 1990) have found a mean stellar metallicity approximately 0.2 dex above solar. This 0.5 dex discrepancy leads one to question whether the mean stellar metallicity is as high as the population synthesis results indicate or if such metal-rich stars produce bright planetary nebulae at all. This could be a clue concerning the mechanism responsible for the variation in the number of bright planetary nebulae observed per unit luminosity in different galaxies (e.g., Hui et al. 1993).

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