An analytical study of the crossing and throwing steps and the distances of pulling and extending the arm of elite javelin throwers and their relationship to achieve menthe researcherAbstract : The javelin throw event is one of the distinguished events in athletics, and it requires physical capabilities and special movement capabilities in addition to some physical specifications. Approximate or final throwing phase.The importance of research is highlighted by the continuous interest in sports achievements and the continuation of the process of developing them, and the importance of kinetic analysis in revealing the most important weaknesses of shooters, and the importance of biomechanical variables, especially the last throwing steps, the distance of withdrawal and the extension of the throwing arm during the throwing.The research problem revolved around the importance of identifying some numerical values of the biomechanical variables and their relationship to achievement, focusing on the weaknesses that the Iraqi spear thrower suffers from in the pre-throwing stage of force preparation, and working on analyzing these molecules and applying them to improve technical performance.And the failure to use motor analysis and identify weaknesses with high accuracy, in addition to the lack of interest by the trainers in the characteristics of the values of the biomechanical variables affecting each other in order to program their training programs in order to achieve their goals as quickly as possible and with the least effort.The aim of the research is to identify the most important biomechanical variables related to the stage of preparing the force, which is the speed of the last throwing step and the speed of the penultimate scissor crossing step and the decrease between the speed of these two steps and the distance of pulling and extending the throwing arm and the relationship between these variables with the achievement of the Iraqi elite spear throwers.The researcher used the descriptive approach and correlational relationships in her current study because it is appropriate to the nature of the problem of the study. The research community consisted of elite Iraqi players who are advanced in javelin throwing, and their number is (6) shooters. They took a comprehensive enumeration method. The test was conducted on the research sample in the stadium of the College of Physical Education and Sports Sciences / University of Kufa in preparation for the championship. The Iraqi clubs have the third round, giving each shooter six attempts as in the official races, and the best attempt was taken as an achievement for the analysis, and two analysis cameras (CASIO FH13.5) were used at a speed of 120 frames per second, and the analysis was done with the analysis program (Kenova). After analyzing and discussing the results, the researcher concluded that there is a relationship A direct correlation between the length and speed and the distance of the throwing arm with the achievement and an inverse correlation between the steps and the time of the steps and the difference between the two speeds and the distance of the stretch with the achievement.
دراسة تحليلية لخطوتي التقاطع والرمي ومسافتي السحب والمد لذراع رماة الرمح النخبة وعلاقتها بالانجاز
last crossover steps - pull distance - javelin throw
Publication Date
Mon Apr 06 2020
Journal Name
August
INFLUENCE OF SOME FACTOR ON SOMATIC EMBRYOS INDUCTION
AND GERMINATION OF DATE PALM CV BARHI BY USING CELL
SUSPENSION CULTURE TECHNIQUE
This study was done to examine different concentrations of mercuric chloride (Hgcl2) for Explants sterilization and different
concentration of NAA) mg/L with 2iP for their effect on initiation primary callus and subsequent embryogenesis in Phoenix
dactyliferae cultivar Barhi. Leaf primordial and shoot tips were excised from 2-3 years old offshoot. The result showed that
contamination percentage decreased with an increase in concentration of Hgcl2 for two explants where in the control (0.0)%
gave highest value 75% and 62.5% of contamination for leaf primordial and shoot tip respectively while the addition (0.1)%
gave a significant decrease 37.5 and 0% for explants respectively. The Explants were inoculated onto Murashiege and Skoog
1962 (MS) medium supplemented with 2iP 3mg/L and containing 0
25
50 or 100 mg/L of NAA
the addition (50) mg/L of NAA
gave highest value 68.8% in percentage of callus initiation with significant difference from addition 0% gave lowest value
(18.8)%
as well Explants of shoot tip gave significant difference was 53.1% while leaf primordial gave 28.1%
Primary callus
was transferred to fresh MS medium containing (0
5
10 and 20) mg/L of NAA with 3mg/L 2iP
Results were recorded after 12
weeks. A highest value of embryonic callus induction percentage or fresh weight and dry weight 87.5% or 1.56g and 0.47g for
the character respectively for the treat 20 mg/L while control treatment 0.0 gave the lowest value 12.5% or 0.37g and 0.14g for
same character respectively. Inoculated 1g fresh biomass into a 250 ml Erlenmeyer flask containing 50 ml MS liquid medium
supplemented with NAA 20mg/L and agitated at 150 rpm by shaker to making suspension culture the measurements of
packed cell volume ( pcv) or fresh and dry weight taken weekly for 12 weeks
maximum values were reached in the eighth week
of PCV and fresh weight but the dry weight reached to highest value in seventh week
then the curve began to decline
gradually until it reached stability in the last two weeks. The cell suspension was Diluted to different initial cell density of 100
500
10000
50000 and 100000 cells /ml with hemocytometer. The initial cell number of (10000) cells gave significant different
of plating efficiency PE (11.6)% while (100) cells gave lowest value 1.8% of PE.