Cultivation ofSpirulina in sewage for poultry feed

Cellular and Molecular Life Sciences - A method for cultivatingSpirulina platensis in domestic raw sewage, coupled with pisciculture and water reclamation in an integrated recycling system, has...     

The mechanical response of isolated arteries to potassium

Zusammenfassung Die vasodilatatorische Wirkung der K⁺-Ionen wird bei Applikation von aussen auf Segmente der Art. facialis des Rindes, die in einer feuchten Kammer unter Druck gesetzt wurden, nachgewiesen. Die Befunde werden im Hinblick auf die Bedeutung des Kaliums für die Durchblutungsregulation im Muskel diskutiert.     

Intestinal vasodilatation after mechanical stimulation of the jejunal mucosa

Zusammenfassung Mechanische Reizung der Dünndarmmukosa bewirkt eine Zunahme in der gesamten Durchblutung des Dünndarms bei der Katze. Diese vermehrte Durchblutung wird nicht beeinflusst durch Denervierung und/oder Ganglienblockade.     

Liberation of mechanical tension by heating of collagen fibres

Zusammenfassung Die Wärmekontraktion der Collagenfaser kann durch ein Gewicht verhindert werden. Nach Entlastung gibt eine solche Faser bei Erwärmung eine maximale Wärmekontraktion (Schrumpfung). Das erklärt sich aus Spannungsmessungen mittels einer «isometrischen Methode». Erwärmung bis 62–65°C bewirkt nur einen Teil der Spannung. Die Restspannung wird erst erreicht, knapp bevor die Faser bereits zu erschlaffen beginnt. Die Restspannung erklärt, dass eine unbelastete Faser auch nach einer vorangehenden Erwärmung noch eine maximale Wärmekontraktion zeigt.     

Experimental hydrocephalus following mechanical increment of intraventricular pulse pressure

Summary Experimental hydrocephalus has been induced in lambs by artificial increase of the amplitude of intraventricular cerebrospinal fluid (CSF) oscillations related to arterial pulsations, without concominant changes of the mean CSF-pressure. The characteristics of this hydrocephalus demonstrate that the intraventricular CSF-pulsations can play a role in the genesis of ventricular dilatation. Such a method may be used to produce an original model of hydrocephalus independent of changes of CSF-circulation or absorption.This work was supported by grant of CNR.     

A mechanical study of the cat retractor bulbi muscle

Zusammenfassung Die mechanischen Eigenschaften des M. retractor bulbi in der Katze (Anstiegs- und Abfallzeiten der Einzelzuckung und der tetanischen Kontraktion und Fusionsfrequenz) liegen zwischen den Eigenschaften der schnellen und langsamen Zuckungsfasern des M. obliquus inferior.

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This investigation was supported by Public Health Service Program Project Research Grant No. NB 06038, General Research Support Grant No. 5 S01 FR-05566, and Research Career Program Award No. K3-NB-14,094 to Dr.Bach-y-Rita from the National Institute of Neurological Diseases and Blindness.     

Frequency-domain study of the mechanical response of living striated muscle

Summary Small-amplitude sinusoidal displacements, in the frequency rang 4–100 Hz, were applied to intact whole frog sartorius muscle whilst in a state of tetanus. At low frequencies the muscle, was observed to do oscillatory work, while at higher frequencies it tended towards elastic behaviour. Frequency-response plots obtained were compared with those from other muscle preparations. Results were interpreted in terms of mechano-chemical transduction properties of muscle.The authors wish to thank the Australian Research Grants Commission for provision of the laser, and L. I. Patterson for construction of the mechanical apparatus.     

Techniques of removing saponins from Mahua (Bassia longifolia) seed cake and its suitability as animal feed

Summary A new process of removing saponins from Mahua seed cake, a commonly available tree of genusBassia, has been developed. The processed cake when added to the rations of calves to the extent of 50% digestible crude protein replacement, had no adverse effect on growth rate of cross-bred dairy calves.     

Experimental study on the mechanical properties of rocks at high temperature

The mechanical properties of marble,limestone,and sandstone as well as the stress-strain curve,the varying characteristics of the peak strength,the peak strain and elastic modulus were studied by using the MTS810 Rock Mechanics Servo-controlled Testing System under the action of temperatures ranging from room temperature to 800℃.Results show that (1) the peak strength and elastic modulus of marble fluctuate at the temperature from normal to 400℃ ;and they decrease gradually over 400 ℃.(2) With the rise of t...     

Damage by ozone to the mechanical integrity of the protoplast plasmalemma

Summary Ozone acts on the plasmalemma as to weaken its mechanical properties. This results in the bursting of protoplasts.This work was carried ont with the help of a grant by the FCAC, Ministère de l'Education du Québec, Canada.     

Plant-sucking bugs can remove the contents of cells without mechanical damage

Summary A mirid and a coreid, feeding on a variety of plant tissues, evacuated the contents of cells up to 3.5 mm from the furthest penetration of their mouthparts. A pectinase occurred in the salivary glands of the mirid and an invertase in those of the coreid, but not vice versa. Cells in the mirid lesions were apparently emptied while the walls retained their shape, whereas coreid lesions showed an immediate inward collapse of cell walls and engorgement of intercellular spaces.14 October 1986Work based on the Biology Department of the University of Papua New Guinea, to which I am grateful for provision of facilities. I am especially grateful to Dr Elaine Brough for arranging the contacts and visits that made field observations and collection of materials possible.     

The mechanical and biochemical effects of pentoxifylline on the perfused rat heart

Perfusion of the isolated rat heart at constant heart rate and coronary flow with the inhibitor of cyclic nucleotide phosphodiesterase, pentoxifylline (10(-4) moles/l), produced no significant effect on the maximum rate and the peak of contraction, but increased the maximum rate of relaxation. cAMP level and cAMP-dependent protein kinase activity were increased in the absence of changes in cGMP. The results were identical in hearts of reserpinized rats.     

The mechanical and biochemical effects of pentoxifylline on the perfused rat heart

Summary Perfusion of the isolated rat heart at constant heart rate and coronary flow with the inhibitor of cyclic nucleotide phosphodiesterase, pentoxifylline (10^–4 moles/l), produced no significant effect on the maximum rate and the peak of contraction, but increased the maximum rate of relaxation. cAMP level and cAMP-dependent protein kinase activity were increased in the absence of changes in cGMP. The results were identical in hearts of reserpinized rats.This work was supported by grants from the Consejo Nacional de Investigaciones Cientificas y Técnicas and the Comisión de Investigaciones Científicas. Buenos Aires, Argentina.We thank Hoechst Laboratories for the partial support and Mrs Alicia R. Ramirez and María Prinzo for the excellent technical assistance.     

Effect of substrates on the mechanical performance of rhesus monkey papillary muscle

This study examines the effect of different substrates on mechanical performance of excised papillary muscles from rhesus monkeys which had been divided into a control group and an experimental group fed a high fat diet for 5 months prior to sacrifice. The results show that performance is affected by availabel substrate for both groups. The performance of the experimental group was depressed relative to control with the short chain fatty acid, butyrate (C4), producing a monotonically decreasing force-frequency response. Relative to the other mammals, isolated rhesus papillary muscles exhibited a protracted treppe which was sensitive to beta-adrenergic blockade with propranolol.