scholarly journals The heat-tension ratio in prolonged tetanic contractions

1931 ◽  
Vol 108 (759) ◽  
pp. 522-537 ◽  
Keyword(s):  
Lactic Acid ◽  
Heat Production ◽  
Acid Formation ◽  
The Absolute ◽  
Do So

It was found by Hartree and Hill (1921) that in tetanic contractions of various durations the relation between heat liberated and duration of stimulus soon becomes linear; from the slope of the curve relating the two variables the absolute values of the heat production were calculated, per centimetre length of muscle, per gramme weight of tension maintained, per second of stimulus, in contractions at various temperatures. No observations, however, were made with tetani longer than 2 seconds. The isometric time coefficients of lactic acid formation and of phosphagen breakdown (subsequently denoted, following Meyerhof, by the symbols K 2 ( I .) and K 2 ( P ) respectively) have been determined by various workers and summarised by Meyerhof (1930, pp. 102, 234, etc.). Recently, however, the existence of delayed lactic acid formation following a tetanus, long maintained by embden and his school, has been confirmed by Meyerhof and his collaborators (1931), who failed to do so in several previous investigations. Lundsgaard (1931) also has found that the anaerobic delayed lactic acid formation following a 5-second tetanus may be over one-half of the total lactic acid set free. When there is a delayed lactic acid formation amounting to as much as, or more than, 100 per cent. of that occurring during the contraction proper, it is obvious that the values of K 2 ( I .) and K 2 ( P ) lack significance unless the time from the end of the stimulus at which the chemical determinations are made is specified. The older chemical investigations mentioned thus require revision, which has been given in a recent paper by Meyerhof and Schulz (1931).

scholarly journals The absolute value of the isometric heat coefficient TI/H in a muscle twitch, and the effect of stimulation and fatigue

1928 ◽  
Vol 103 (723) ◽  
pp. 163-170 ◽  
Keyword(s):  
Lactic Acid ◽  
Heat Production ◽  
Muscle Length ◽  
Mean Value ◽  
Sartorius Muscle ◽  
Muscle Twitch ◽  
Absolute Value ◽  
The Subject ◽  
The Absolute ◽  
Initial Heat

It is not technically possible to determine directly the lactic acid set free in a sing1e muscle twitch. It is necessary to calculate it from the initial heat production, or from the tension developed. The anaerobic liberation of 1 gramme of lactic acid in musc1e is accompanied, according to Meyerhof, by the production of 385 calories of heat (1). This 1eads to the equation:- 1 gramme-cm.(heat) ≡ 6·14 × 10 -8 gramme lactic acid. (I) The isometric coefficient of lactic acid, defined for a twitch or a series of twitches by the equation* K m =(grammes tension developed) (cms. muscle length)/(grammes lactic acid produced), has been the subject of much investigations by meyerhof and his colleagues (2, 3, 4, 5). Matsuoka, for the frog's sartorius muscle in Ringer's solutions, found a mean value of 1·05 × 10 8 (variation 0·69 to 1·36). Meyerhof and Lohmann, for frog's gastrocnemius, gave 1·40 × 10 8 as a mean, while Meyerhof and Suchulz gave 1·43 × 10 8 (variation 1·12 to 1·66). In the gastrocnemius, however, the fibres are not straight, and do not run parallel to the muscle length; consequently it is necessary to mutiply (see Mashino(6), A. V. Hill(7)) the value so found by a factor of roughly 0·63 to allow for the skew disposition of the fibres. This gives, when corrected, 0·9 × 10 8 for the gastrocnemius, so that taking account of the value 1·05 × 10 8 found by Matsuoka for the sartorius, the round figure 1 × 10 8 may be accepted. This leads to the equation:- 1 gramme-cm.(tension-length) ≡ 10 -8 gramme lactic acid.

scholarly journals Recovery heat in muscular contraction without lactic acid formation

1931 ◽  
Vol 108 (757) ◽  
pp. 279-301 ◽  
Keyword(s):  
Acetic Acid ◽  
Oxygen Consumption ◽  
Lactic Acid ◽  
Muscular Contraction ◽  
Acid Formation ◽  
Anaerobic Conditions ◽  
Spontaneous Breakdown ◽  
Rate Of Oxygen Consumption ◽  
Resting Muscle

In a comparison of muscles poisoned with mono-iodo-acetic acid (IAA) in the presence and in the absence of oxygen respectively, Lundsgaard (1930) found:- (1) That the spontaneous breakdown of phosphagen in poisoned resting muscle is much more rapid under anaerobic conditions. (2) That the onset of the characteristic contracture produced by IAA is accompanied always by an increase in the rate of oxygen consumption.

Frequency and Tense Use in French

1998 ◽  
Vol 12 ◽  
pp. 43-60 ◽  
Author(s):  
Arie Molendijk ◽  
Henriette E. de Swart
Keyword(s):  
General Rule ◽  
Concrete Situation ◽  
Dependent Frequency ◽  
Temporal Relationships ◽  
The Absolute ◽  
Do So

Abstract. This paper deals wilh the use of Ihe passé simple and the imparfait of French in frequentative sentences. It is argued that frequency implies sentence-internal quantification, meaning that frequentative sentences report just one (complex) eventuality. This claim is related to the fact that, as far as establishing temporal relationships between eventualities is concerned, sentences containing frequency adverbs behave like sentences that don't imply quantification at all. So they may establish all kinds of temporal relationships between eventualities. Given the claims put forward in this paper about the temporal meaning of the passe* simple and the imparfait (Molendijk 1990), it naturally follows that, as a general rule, frequency adverbs combine with both tenses. But they do not always do so under exactly the same circumstances. In this regard, a distinction can be made between dependent frequency adverbs {tout le temps 'all the time' etc.), which imply reference to a contextually determinable concrete situation, and independent ones (toujours 'always', etc.), which may be used without any reference to such a situation. This distinction helps us to understand, for instance, why dependent frequency adverbs do not easily combine with the 'absolute' (non-narrative) passe simple, whereas they do combine with the imparfait and the 'narrative' passé simple.

Lactic Acid Formation

Science ◽  
1938 ◽  
Vol 88 (2282) ◽  
pp. 10-10
Keyword(s):  
Lactic Acid ◽  
Acid Formation

scholarly journals Lactic Acid Formation and Carbon Dioxide Fixation

Nature ◽  
1957 ◽  
Vol 180 (4594) ◽  
pp. 1053-1053 ◽  
Author(s):  
D. A. BARBER
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Carbon Dioxide Fixation ◽  
Acid Formation

Tennant's Struggle with a “Desperate Task”

1942 ◽  
Vol 35 (3) ◽  
pp. 199-208
Author(s):  
Graham Frisbee
Keyword(s):  
William James ◽  
Face To Face ◽  
The Absolute ◽  
The Universe ◽  
Do So

In his essay, “On God and the Absolute,” F. H. Bradley declares that the “assertor of an imperfect God is, whether he knows it or not, face to face with a desperate task or a forlorn alternative. He must try to show (how I cannot tell) that the entire rest of the Universe, outside his limited God, is known to be still weaker and more limited. Or he must appeal to us to follow our Leader blindly and, for all we know, to a common and overwhelming defeat.” The appeal of the second course, even when it is set forth in the spirited and heroic manner of William James, cannot survive a full realization of what is involved in such a prospect. It is not surprising, therefore, to find that most of the more sober-minded theologians who hold the idea of a limited God attempt to do so in the first form suggested by Bradley. F. R. Tennant belongs to this group. And it is his attempt to accomplish the “desperate task” that we propose to examine.

scholarly journals Lactic acid formation in muscle extracts

1929 ◽  
Vol 23 (3) ◽  
pp. 583-586 ◽  
Author(s):  
David Stiven
Keyword(s):  
Lactic Acid ◽  
Acid Formation

scholarly journals Metabolism of propane-1:2-diol infused into the rumen of sheep

1972 ◽  
Vol 27 (3) ◽  
pp. 553-560 ◽  
Author(s):  
J. L. Clapperton ◽  
J. W. Czerkawski
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Energy Metabolism ◽  
Heat Production ◽  
Volatile Fatty Acids ◽  
Carbon Dioxide Production ◽  
Total Volatile

1. Propane-1:2-diol (loog/d) was infused through a cannula into the rumen of sheep receiving a ration of hay and dried grass. The concentration of volatile fatty acids, propanediol, lactic acid and of added polyethylene glycol, and the pH of the rumen contents were measured. The energy metabolism of the sheep was also determined.2. Most of the propanediol disappeared from the rumen within 4 h of its infusion. The infusion of propanediol resulted in a 10% decrease in the concentration of total volatile acids; the concentration of acetic acid decreased by about 30%, that of propionic acid increased by up to 60% and there was no change in the concentration of butyric acid.3. The methane production of the sheep decreased by about 9% after the infusion of propanediol and there were increases in the oxgyen consumption, carbon dioxide production and heat production of the animals; each of these increases was equivalent to about 40% of the theoretical value for the complete metabolism of 100 g propanediol.4. It is concluded that, when propanediol is introduced into the rumen, a proportion is metabolized in the rumen and a large proportion is absorbed directly. Our thanks are due to Dr J. H. Moore for helpful discussions, to Mr D. R. Paterson, Mr J. R. McDill and Mr C. E. Park for looking after the animals and to Miss K. M. Graham, Miss A. T. McKay and Mrs C. E. Ramage for performing the analyses.

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