XXII.—A Quantitative Study of Spermatozoan Nucleus Length in Drosophila melanogaster (Meig).

1964 ◽  
Vol 68 (4) ◽  
pp. 327-335
Author(s):  
N. S. Sidhu
Keyword(s):  
Drosophila Melanogaster ◽  
Quantitative Study ◽  
Coefficient Of Variation ◽  
Logarithmic Transformation ◽  
Quantitative Variation ◽  
Length Variation ◽  
Preparation Technique ◽  
Squash Preparation ◽  
Factors Affecting ◽  
High Coefficient

SynopsisA squash-preparation technique for the measurement of nucleus lengths in permanent preparations of the spermatozoa of Drosophila melanogaster is described. Prefixation gave longer nuclei, but the degree of pressure used in making the squash did not affect nucleus length. Variation in nucleus length between the spermatozoa of a male was fairly high (coefficient of variation 14 per cent). Smaller, though significant, differences existed between means of males within culture bottles, but there were no significant differences between means of duplicate culture bottles. There was a little evidence of heterogeneity of within-male variances. A logarithmic transformation of data before analysis was indicated. These observations provide a hitherto missing background for planning experiments in quantitative variation designed to throw light on genetic and other factors affecting the dimensions of Drosophila spermatozoa.

scholarly journals Ground Reaction Forces of Dressage Horses Performing the Piaffe

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 436 ◽  
Author(s):  
Hilary Mary Clayton ◽  
Sarah Jane Hobbs
Keyword(s):  
Coefficient Of Variation ◽  
Three Dimensional ◽  
Individual Variability ◽  
The Other ◽  
Ground Reaction Forces ◽  
High Coefficient ◽  
Reaction Forces

The piaffe is an artificial, diagonally coordinated movement performed in the highest levels of dressage competition. The ground reaction forces (GRFs) of horses performing the piaffe do not appear to have been reported. Therefore, the objective of this study was to describe three-dimensional GRFs in ridden dressage horses performing the piaffe. In-ground force plates were used to capture fore and hindlimb GRF data from seven well-trained dressage horses. Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs (7.39 ± 0.99 N/kg vs. 6.41 ± 0.64 N/kg; p < 0.001) with vertical impulse showing a trend toward higher forelimb values. Peak longitudinal forces were small with no difference in the magnitude of braking or propulsive forces between fore and hindlimbs. Peak transverse forces were similar in magnitude to longitudinal forces and were mostly directed medially in the hindlimbs. Both the intra- and inter-individual variability of longitudinal and transverse GRFs were high (coefficient of variation 25–68%). Compared with the other diagonal gaits of dressage horses, the vertical GRF somewhat shifted toward the hindlimbs. The high step-to-step variability of the horizontal GRF components is thought to reflect the challenge of balancing on one diagonal pair of limbs with no forward momentum.

scholarly journals Experimental study on the factors affecting torque of beam-type implant torque wrenches

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hiroki Shiba ◽  
Yuji Sato ◽  
Junichi Furuya ◽  
Tokiko Osawa ◽  
Akio Isobe ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Leading Edge ◽  
Beam Width ◽  
Factors Affecting ◽  
Tightening Force ◽  
Torque Wrench ◽  
Screw Breakage ◽  
Beam Type ◽  
Accuracy And Repeatability ◽  
Excellent Accuracy

Abstract Background Screw breakage and loosening are the most common mechanical complications associated with implant treatment, and they may occur due to excess or inadequate screw tightening torque. When fastening and fixing the implant superstructure, screws are tightened using a torque wrench, which is essential for an accurate tightening force. However, the characteristics of the torque wrench have not been fully verified. Therefore, we aimed to clarify the factors affecting the torque with a focus on beam-type torque wrenches, which are the main types of wrenches. Methods The torque values generated by beam-type torque wrenches from eight manufacturers were measured using a torque gauge. To investigate the influence of the location of the beam relative to the scale, measurements were performed with a scale aligned with the trailing edge, center, and leading edge of the beam respectively. Additionally, measurements were taken at 90°, 60°, and 30° to examine the effect of the angle at which the examiner read the torque value. Under each condition, a single examiner applied the recommended torque to each manufacturer's screws five times in a clockwise direction. The average measured torque, standard deviation, bias, and coefficient of variation were calculated and compared accordingly. Results Wrenches from six manufacturers demonstrated excellent accuracy for measurements at the center of the beam (bias within ± 4%). For measurements at 90°, equipments from five manufacturers displayed excellent accuracy (bias within ± 7%), and seven showed excellent repeatability (coefficient of variation ≤ 2%). Conclusion The scale should be aligned with the center of the beam and read from 90° while using a torque wrench. The accuracy and repeatability torques generated by the wrenches differed according to the manufacturer, scale width, scale line width, beam width, and distance between the scale and beam center. Based on these results, we suggest that a torque wrench must be selected after determining the difference in the structure of the torque wrench.

scholarly journals Hybrid dysgenesis-induced quantitative variation on the X chromosome of Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 124 (3) ◽  
pp. 627-636
Author(s):  
C Q Lai ◽  
T F Mackay
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Quantitative Traits ◽  
Natural Populations ◽  
Quantitative Variation ◽  
Hybrid Dysgenesis ◽  
X Chromosomes ◽  
Bristle Number ◽  
Seven Generations ◽  
Polygenic Variation

Abstract To determine the ability of the P-M hybrid dysgenesis system of Drosophila melanogaster to generate mutations affecting quantitative traits, X chromosome lines were constructed in which replicates of isogenic M and P strain X chromosomes were exposed to a dysgenic cross, a nondysgenic cross, or a control cross, and recovered in common autosomal backgrounds. Mutational heritabilities of abdominal and sternopleural bristle score were in general exceptionally high-of the same magnitude as heritabilities of these traits in natural populations. P strain chromosomes were eight times more mutable than M strain chromosomes, and dysgenic crosses three times more effective than nondysgenic crosses in inducing polygenic variation. However, mutational heritabilities of the bristle traits were appreciable for P strain chromosomes passed through one nondysgenic cross, and for M strain chromosomes backcrossed for seven generations to inbred P strain females, a result consistent with previous observations on mutations affecting quantitative traits arising from nondysgenic crosses. The new variation resulting from one generation of mutagenesis was caused by a few lines with large effects on bristle score, and all mutations reduced bristle number.

Environmental factors affecting the quantity of alcohol dehydrogenase in Drosophila melanogaster

Nature ◽  
1979 ◽  
Vol 280 (5722) ◽  
pp. 517-518 ◽  
Author(s):  
BRYAN CLARKE ◽  
ROBERT G. CAMFIELD ◽  
ALISON M. GALVIN ◽  
CHRISTOPHER R. PITTS
Keyword(s):  
Drosophila Melanogaster ◽  
Environmental Factors ◽  
Alcohol Dehydrogenase ◽  
Factors Affecting

scholarly journals Factors Affecting the Meaning in Life of Teachers

Pedagogika ◽  
2020 ◽  
Vol 139 (3) ◽  
pp. 52-72
Author(s):  
Suyatno ◽  
Dholina Inang Pambudi ◽  
Ganis Amurdawati ◽  
Wantini ◽  
Mei Vita Romadon Ningrum
Keyword(s):  
Quantitative Study ◽  
Meaning In Life ◽  
Policy Makers ◽  
Factors Affecting ◽  
East Kalimantan ◽  
Self Actualization ◽  
Self Transcendence ◽  
And Training

This study aims to investigate the various models that affect the meaning in life of teachers. This is a quantitative study with data randomly obtained from a sample of 100 teachers at East Kalimantan, Indonesia. The results showed that self-actualization and self-transcendence are crucial factors which have an impact on the meaning in life of teachers. The policy makers need to utilize the results from this study to design various programs and training for the development of meaning in life of teachers.

scholarly journals MOLECULAR POPULATION GENETICS OF THE ALCOHOL DEHYDROGENASE GENE REGION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 114 (4) ◽  
pp. 1165-1190
Author(s):  
Charles F Aquadro ◽  
Susan F Desse ◽  
Molly M Bland ◽  
Charles H Langley ◽  
Cathy C Laurie-Ahlberg
Keyword(s):  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Sequence Variation ◽  
Natural Populations ◽  
Restriction Map ◽  
Length Variation ◽  
Eastern United States ◽  
Chromosome Inversion ◽  
Frequency Spectra ◽  
Adh Activity

ABSTRACT Variation in the DNA restriction map of a 13-kb region of chromosome ll including the alcohol dehydrogenase structural gene (Adh) was examined in Drosophila melanogaster from natural populations. Detailed analysis of 48 D. melanogaster lines representing four eastern United States populations revealed extensive DNA sequence variation due to base substitutions, insertions and deletions. Cloning of this region from several lines allowed characterization of length variation as due to unique sequence insertions or deletions [nine sizes; 21-200 base pairs (bp)] or transposable element insertions (several sizes, 340 bp to 10.2 kb, representing four different elements). Despite this extensive variation in sequences flanking the Adh gene, only one length polymorphism is clearly associated with altered Adh expression (a copia element approximately 250 bp 5′ to the distal transcript start site). Nonetheless, the frequency spectra of transposable elements within and between Drosophila species suggests they are slightly deleterious. Strong nonrandom associations are observed among Adh region sequence variants, ADH allozyme (Fast vs. Slow), ADH enzyme activity and the chromosome inversion ln(2L)t. Phylogenetic analysis of restriction map haplotypes suggest that the major twofold component of ADH activity variation (high vs. low, typical of Fast and Slow allozymes, respectively) is due to sequence variation tightly linked to and possibly distinct from that underlying the allozyme difference. The patterns of nucleotide and haplotype variation for Fast and Slow allozyme lines are consistent with the recent increase in frequency and spread of the Fast haplotype associated with high ADH activity. These data emphasize the important role of evolutionary history and strong nonrandom associations among tightly linked sequence variation as determinants of the patterns of variation observed in natural populations.

ESTIMATION OF UNCERTAINTY IN MEASUREMENT OF DOSE EQUIVALENT AT LABORATORY LEVEL USING CASO4 :Dy-BASED TLD BADGE SYSTEM IN INDIA

2019 ◽  
Vol 188 (2) ◽  
pp. 135-147 ◽  
Author(s):  
S M Pradhan ◽  
D Datta ◽  
Munir S Pathan ◽  
Kshama Srivastava ◽  
T Palani Selvam
Keyword(s):  
Coefficient Of Variation ◽  
Whole Body ◽  
Dose Equivalent ◽  
Radiation Quality ◽  
Variance Model ◽  
Factors Affecting ◽  
Uncertainty In Measurement ◽  
Photon Dose ◽  
Combined Uncertainty ◽  
Quality Coefficient

Abstract The objective of this paper is to estimate the combined uncertainty in the measurement of dose equivalent at laboratory level using CaSO4:Dy-based thermoluminescent dosemeter badge system by including variations in the components of the system. The variability of performance of the system is analysed using random effects one way analysis of variance model. The model enables estimation of the overall variance of the performance of the sampled population. The population in the study comprises all possible indicated dose equivalents on irradiation of dosemeters to a specific dose equivalent and radiation quality. Coefficient of variation and combined uncertainty at 95% level of confidence in the measurement of Hp(10) due to S-Cs radiation quality are found to be 6.6 and 14.3%, respectively, at the dose level of 5.31 mSv. The above parameters in the measurement of in-use quantity, i.e. whole body dose or photon dose equivalent are found to be 7.4 and 16.4%, respectively. The performance of the monitoring system on relative response has been observed to be satisfactory. Various factors affecting the variability of performance of the system are identified for further improvement in coefficient of variation.

Alginate hydrogel – candidate support for cell transplantation

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Piotr Woźniak ◽  
Marek Kozicki ◽  
Janusz M. Rosiak ◽  
Jacek Przybylski ◽  
Malgorzata Lewandowska-Szumieł
Keyword(s):  
Cell Transplantation ◽  
Quantitative Study ◽  
Alginate Hydrogel ◽  
Human Cartilage ◽  
Factors Affecting ◽  
Hydrogel Beads ◽  
Encapsulated Cells ◽  
Candidate Support

AbstractHuman cartilage derived cells were encapsulated in alginate hydrogel beads. Viability of the cells was determined using both qualitative (microscopy) and quantitative (MTT and NR assays) examination. Microscopy indicated that encapsulated cells remained viable during the 7-days experiment. The quantitative tests failed to give reliable results. Possible factors affecting the results of the quantitative study are discussed.

Genetic correlations for reproductive and growth traits in rabbits

2020 ◽  
Vol 100 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Rym Ezzeroug ◽  
Rafik Belabbas ◽  
Maria José Argente ◽  
Ali Berbar ◽  
Samir Diss ◽  
...  
Keyword(s):  
Litter Size ◽  
Coefficient Of Variation ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
High Coefficient ◽  
Genetic And Phenotypic Correlations ◽  
The Common ◽  
Large Coefficient ◽  
Size At Birth

The objective of this study was to obtain heritability estimates for reproductive (litter size at birth, number born alive, litter size at weaning) and growth traits (individual weaning weight, individual weight at the end of the fattening period), then determine the genetic correlation between them in a synthetic rabbit line. A total of 805 females, 3242 parities, and 18 472 growth records were measured from 2006 to 2017. A pentavariate animal model was used with reproductive and growth traits. Heritability ranged from 0.025 to 0.126 for reproductive traits and from 0.033 to 0.059 for growth traits. These traits showed a large coefficient of variation (from 32% to 56% for reproductive traits and from 21% to 28% for growth traits). The repeatability of reproductive traits was low and the common litter effect for growth traits was the most important component of total variance. The genetic and phenotypic correlations between reproductive and growth traits were high and negative, especially with weight at weaning (−0.848, −0.922, and −0.854 for litter size at birth, number born alive, and litter size at weaning, respectively). In conclusion, because of the high negative correlation between reproductive and growth traits, both reproductive and growth traits should be selected in independent lines and the response to selection should be due mainly to the high coefficient of variation of the traits.

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