Sprinting

The system has recently been used with success for inspection of 11 inclined nozzle welds during the R1 SPRINT project at Vattenfall Ringhals, Sweden during the summer 1997. At the moment a full system and personal qualification is prepared for inspection of the pressurizer spray nozzle weld at Vattenfall Ringhals, block 2 at May, 1998. 

The process is rather like a sprint race, with all ions leaving the starting line at the same time. However, unlike a normal race, the result is always the same viz., the ions arrive at the finish (collector or detector) in procession and strictly in the order of increasing m/z values. Ions of the smallest m/z values arrive first, followed successively by others of increasing m/z value. 

Interim results from the SPRINT-1 phase 2 trial of boceprevir (SCH 503034) have been released. In subjects who received boceprevir plus interferon-a and ribavirin, viral RNA loads were suppressed at week 12 in between 70 and 79% of subjects infected with genotype 1 HCV, compared with only 34% in the interferon-o/ ribavirin standard of care arm (www.sch-plough.com/schering plough/news/release. jsp releaseID = 1064540). However, it is not yet known if this enhanced early response will translate into sustained response. 

In view of the two types of fibers in skeletal muscle and of the various energy sources described above, it is of interest to compare their involvement in a sprint (eg, 100 meters) and in the marathon (42.2 km just over 26 miles) (Table 49—11). 

AMP. PFK-1 is activated by AMP, Pj, and NH3. Attesting to the efficiency of these processes, the flux through glycolysis can increase as much as 1000-fold during a sprint. 

Skeletal muscle functions under both aerobic (resting) and anaerobic (eg, sprinting) conditions, so both aerobic and anaerobic glycolysis operate, depending on conditions. 

Two major types of muscle fibers are found in humans white (anaerobic) and red (aerobic). The former are particularly used in sprints and the latter in prolonged aerobic exercise. During a sprint, muscle uses creatine phosphate and glycolysis as energy sources in the marathon, oxidation of fatty acids is of major importance during the later phases. Nonmuscle cells perform various types of mechanical work carried out by the structures constituting the cytoskeleton. These strucmres include actin filaments (microfilaments), micrombules (composed primarily of a- mbulin and p-mbulin), and intermediate filaments. The latter include keratins, vimentin-like proteins, neurofilaments, and lamins. 

Collomp, K., Ahmaidi, S., Chatard, J. C., Audran, M., and Prefaut, C., Benefits of caffeine ingestion on sprint performance in trained and untrained swimmers, International Journal of Applied Physiology, 64, 377, 1992. 

Here t, is still a ratio of a viscosity to a modulus, as in the spring-dashpot model of Figure 1, but each sprint has the same (shear) modulus, pRTfM and the steady-flow viscosity T] of equation (16) is the sum of the viscosities of the individual submolecules. Molecular theories are discussed more fully in Section X. 

SPRINT RA 25 is a transnational collaborative project among seven laboratories, each from a different Member State of the EEC. These laboratories are ... 

Direct calorimetry Energy expenditure can be measured from the heat lost by an individual, which is the same as that produced. All the energy used in the daily activities of the body is released as heat. For example, the mechanical energy expended walking to work, sprinting for the train or running a marathon is converted into heat. The method used for measuring heat production is known as direct calorimetry (Box 2.1). The individual lives in a... 

Data from Passmore Durnin (1955) Ekblom (1992) Durnin Passmore (1967) and Astrand Rodahl (1986). For the sprint see Margaria et at. (1966). 

The rate of glycolysis from glycogen during sprinting in a young adult male is about 50 pmol/g tissue per min, i.e. an increase of more than 1000-fold (see Chapters 3 and 13). 

Figure 13.4 Electron micrographs of the different fibres in different athletes. The fibre composition (type I and type II) of two selected top athletes, (a) A swimmer, whose speciality is the 50 metre crawl sprint, (b) A professional world-class cyclist of the roller type, (c) and (d) Cryostat sections of the swimmer s and cyclist s vastus lateralis stained for myosin ATPase, after preincubation at pH 4.3. Type I fibres stain dark, type II fibres remain unstained, (c) Almost all of the swimmer s fibres are type II. (d) Almost all of the cyclist s fibres are type I. Photographs kindly provided by Professor Hans Hoppeler, Department of Anatomy, University of Bern, Switzerland. Published in Strength and Power in Sport, ed. P.V. Komi, Blackwell Science (1992), pp.39-63.

A fuel is a compound that leads to generation of ATP from ADP and P, (Figure 13.17). The fuels used by muscle differ according to fibre, the type of activity and the conditions under which the activity takes place. For example, in athletics, the fuel used varies according to the particular event, from the 100 m sprint to the marathon. 

This pathway makes a minor contribution to ATP generation, especially during a 10 km race, but may be significant in the sprint to the tape (wire)... 

During very brief but very high-intensity exercise (sprinting, running upstairs), when there is not sufficient time for the arterioles to dilate to permit increased blood flow to the muscle. 

Only two fuels are used during the 100 m sprint - glycogen and phosphocreatine. The glycogen is converted exclusively to lactic acid. Both fuels contribute to the generation of ATP. The evidence for this observation is that the maximum activity of phos-phorylase, can generate about 3 units of ATP. However, the maximum rate at which ATP can be utilised is about 10 units (Hultman et al. 1990 ... 

In the 5 and 10 km events, phosphocreatine will be used perhaps at the beginning of the event, but especially during the final sprint to the tape when ATP/ADP concentration decreases. 

Most team games (e.g. soccer, rugby, hockey, football) and some individual sports (e.g. squash, tennis) involve intermittent high-intensity bursts of exercise interspersed with rest periods (i.e. mostly less intense periods), although the whole period of activity can be very long. These are known as multiple sprint sports. In experiments that involved a study of short bursts of activity followed by short rest periods, repeated for 30 minutes, the increase in blood... 

Figure 13.21 (a) Metabolic processes used to generate ATP during a short burst of physical activity. A short burst is, for example, a short sprint in a soccer game, a short game in a tennis match. 

Table 13.11 Content of glycogen and concentration of phosphocreatine, ATP and Lactate in muscle before and after sprinting/ strength training exercises...

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