AN ASSESSMENT OF SPEED-STRENGTH ABILITIES IN YOUNG MEN

INTRODUCTION Muscle strength is one of the most important factors in sport performance and other human activities -in this case it concerns the physical preparation of military pilots, particularly in order to develop the +Gz toleration. The study was designed to establish the parameters of speed-strength abilities of upper and lower extremities in young men. It allows us to find out the relationships between age, body mass, speed and muscle strength in order to improve the efficiency of weight training. METHODS One hundred young men (cadet-pilots) participated in the study. They were divided into two main groups: middle aviation school students (n=21; 16.0±1.1 years of age, 173.4±5.3 cm body height, 63.8±10.2 kg body weight) and the Polish Air-Force Academy students (n=79; 20.9±1.4 years of age, 178.0±5.7 cm b.h., 73.3±7.3 kg b.m.). In order to estimate the basic speed-strength parameters of upper and lower extremities both groups performed bench press and squats. Exercises were provided on a computerized stand (locally made) under isokinetic (co = 0.2 radIs) and isotonic (M = 20 Nxm) conditions. The subjects performed three trials with maximal effort to estimate the maximal speed (MS) and the maximal torque (MT) developed in the exercise. Descriptive statistics for each parameter as well as the t-test and Pearson's correlation matrix were used (

PROGRAMMED STRENGTH TRAINING USING A COMPUTERIZED ISOTONIC STAND

One of the very important tasks of the theory and practice of modern training is searching for new methods, in order to improve the efficiency of the training process. Nowadays muscle strength seems to be the most significant factor which influences performance in different kinds of sport. On the other hand development of the strength level is particularly difficult among highperformance athletes. The aim of this paper is to present computer-controlled strength training using a special stand for museie strength training and diagnostics. The stand consists of three main sub-assembles: -mechanical part (steel bedplate, bar with replaceable holders, bench for exercises). -hydraulic resistance module, -efectronic part (valve controller, AlC converter, PC 486/100). A special computer program allows force stabilization in the full range of motion (isotonic resistance) and registration of the basic parameters of movement. The computer-controlled training program includes three basic strength training methods: -repetition (50-80% RM, 4-8 series, 1020 reps); -maximal efforts (90-100% RM, 1-5 series, 1-3 reps); -speed-strength (40-45% RM, 4-8 series, 8-12 reps). Besides these methods the user could exercise according to his (or her) individual program. There are four main indices describing training loads, which can be controlled: resistance, number of series, number of reps and rest periods. Various popular exercises as: bench press, seated press, squats, both-or one-hand pulls, biceps curl. bent over row, etc. can be performed on the stand. The computer program enables registration of the force and displacement of the bar and on this base calculation maximal and mean values of several important parameters of the workout: mechanical power, velocity of the bar, work per rep(s). set(s) and unit(s). The initial resistance is established during the special trials, assessing the speedstrength abilities of the user, and changes of training loads are accomplished automatically, according to achieved results in these trials. The computer-controlled strength training performed on the isotonic stand is designed for both, beginners and highperformance athletes. The equipment can be used under field or laboratory conditions, because it is very safe, not noisy and not too large. REFERENCES Ariel G., Penny M., Saar D.. Selinger A. (1990): Computer-controlled strength training program for the U.S. National Women's Volleyball Team. COTO Research Center. Abstract form. Eliasz J. (1993): Trening sity mi~sniowej w pilee r~cznej (Strength training in handball) Sport Wyczynowy 9/10:21-28. Kannus P. (1994): Isokinetic evaluation of muscular performance: Implications for museie testing and rehabilitation. Int. Journal of Sports Medicine 15. Suppt. 1:S11-18. Kemp M. (1989): Strength training principles. Modem Athlete and Coach 27:11-12. Pauletto B. (1991): Strength training for coaches. Human Kinetics. Champaign IL. Zatsiorsky V.M. (1995): Science and Practice of Strength Training. Human Kinetics. Champaign IL

Menin regulates the serine biosynthetic pathway in Ewing sarcoma

Developmental transcription programs are epigenetically regulated by multiâ protein complexes, including the meninâ and MLLâ containing trithorax (TrxG) complexes, which promote gene transcription by depositing the H3K4me3 activating mark at target gene promoters. We recently reported that in Ewing sarcoma, MLL1 (lysine methyltransferase 2A, KMT2A) and menin are overexpressed and function as oncogenes. Small molecule inhibition of the meninâ MLL interaction leads to loss of menin and MLL1 protein expression, and to inhibition of growth and tumorigenicity. Here, we have investigated the mechanistic basis of meninâ MLLâ mediated oncogenic activity in Ewing sarcoma. Bromouridine sequencing (Bruâ seq) was performed to identify changes in nascent gene transcription in Ewing sarcoma cells, following exposure to the meninâ MLL interaction inhibitor MIâ 503. Meninâ MLL inhibition resulted in early and widespread reprogramming of metabolic processes. In particular, the serine biosynthetic pathway (SSP) was the pathway most significantly affected by MIâ 503 treatment. Baseline expression of SSP genes and proteins (PHGDH, PSAT1, and PSPH), and metabolic flux through the SSP were confirmed to be high in Ewing sarcoma. In addition, inhibition of PHGDH resulted in reduced cell proliferation, viability, and tumor growth in vivo, revealing a key dependency of Ewing sarcoma on the SSP. Loss of function studies validated a mechanistic link between menin and the SSP. Specifically, inhibition of menin resulted in diminished expression of SSP genes, reduced H3K4me3 enrichment at the PHGDH promoter, and complete abrogation of de novo serine and glycine biosynthesis, as demonstrated by metabolic tracing studies with 13Câ labeled glucose. These data demonstrate that the SSP is highly active in Ewing sarcoma and that its oncogenic activation is maintained, at least in part, by meninâ dependent epigenetic mechanisms involving trithorax complexes. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144706/1/path5085_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144706/2/path5085.pd