Showing papers by "Monash University published in 1968"

Studies in perception

Abstract: Even the most cursory study of the academic psychologist as a species will reveal that his life-cycle falls into four natural phases.

Visual orientation during and after lateral head, body, and trunk tilt

Abstract: Visual judgments of orientation were investigated during (effect) and after (aftereffect) different body postures. In Experiment 1 four trained Ss made apparent verticality (AV) judgments before and after 2 min in each of seven orientations: head tilt left and right, body tilt left and right, trunk tilt left and right and a control condition with head ’and body upright. The aftereffect was significant for all postures excepting trunk tilt left and the control. The aftereffect from head tilt was greater than that from the same degree of body tilt, and that in the trunk tilt condition was in the same direction as’ predicted from neck stimulation. In Experiment 2, 30 Ss made AV judgments during tilt in the same seven postures. The E-phenomenon resulted from both head and body tilts, and an effect was found for trunk tilt in the direction predicted from neck stimulation. The results are discussed in terms of the otolith, neck, and trunk receptor systems.

Fine structure of nerve fibres in smooth muscle of the vas deferens in normal and reserpinized rats.

Abstract: IT is evident from Thaemert's1 review that the intra-axonal granular vesicles are generally considered to be the site of storage of catecholamines in autonomic nerves. It has also been shown2–7 that reserpine has a depleting effect on these amine stores in both peripheral and central nervous systems. No quantitative data on the effect of reserpine on various types of granular vesicles have been published, so a study of the effect of this drug on the nerve fibres of the vas deferens of the rat was undertaken.

Autogenetic reflex effects of slow or steady stretch of the calf muscles in man.

Abstract: In a relaxed subject, slight, slow or maintained stretch of the calf muscles, produced by ankle movement or by pressure on the Achilles tendon, reduces the amplitude of the reflex contraction that can be elicited from these muscles by a standard brief electrical stimulation of sensory fibres in the posterior tibial nerve. A slow stretch applied when the subject is strongly contracting the arm muscles, as in Jendrassik's manoeuvre, results in an increase in electrically induced reflex contraction of calf muscles and often there is also a maintained reflex contraction of these muscles opposing the applied stretch. These results are discussed in relation to the possible roles of outflow from primary and secondary spindle endings in altering motoneurone excitability.

The fine structure of the immature human testis in hypogonadotrophic hypogonadism

Abstract: The ultrastructural appearance of the immature human testis was studied in biopsies from 3 patients with hypogonadotrophic hypogonadism. The immature Sertoli cells exhibit an unusual gradation in nucleolar structure and differ from the adult Sertoli cell in the amount and distribution of lipid, agranular and granular endoplasmic reticulum. The cell junctions present between adjacent immature Sertoli cells have an unusual form and their distribution contrasts with that in the adult state. These differences are discussed in relationship to pubertal maturation.

Solids mixing in fluidized beds

Abstract: The movement of solids associated with the rise of a single gas bubble in an incipiently fluidized bed has been determined. The bulk volume, measured at the porosity of incipient fluidization, of tracer solid which is transported across the original interface between undyed glass spheres in the upper region and dyed glass spheres (tracer solid) in the lower region, is approximately 30% of the bubble volume. The measurements relate to bubble volumes from 14 to 200 ml. in a glass column, 4 in. diam. Solids used were glass spheres of diameter 380 μ. The profile created when a bubble rises through a layer of fluidized tracer solids into the fluidized solids above the tracer layer has been approximately determined. The distance by which the solids were displaced upward, due to the passage of the bubble, was found to be greater than would have been the case if the behavior were that of a sphere in an inviscid liquid.

Prostaglandins and toad spinal cord responses.

Abstract: PROSTAGLANDINS have a wide distribution in the vertebrate body and have been shown to be pharmacologically active on many types of vertebrate tissues. Evidence that these compounds have a neurohumoral role is suggested by several findings. Prostaglandins are widely distributed in the central nervous system1, and in the rat cerebral cortex they are localized in synaptic vesicles2. They are released from the feline cortex3 and possibly cerebellum and ventricles4,5. In addition, prostaglandins have effects on the central nervous system of cats and chickens6,7. We decided to investigate the effects of prostaglandins on the isolated toad spinal cord because the preparation is convenient for studying direct actions of drugs on a neuronal pool. Furthermore, prostaglandins are released from the frog spinal cord on stimulation of the hind limbs8, suggesting that they are involved in synaptic transmission in amphibians.

Infrared Receptors in the Facial Pits of the Australian Python Morelia spilotes

Abstract: There is a series of pits in the scales of the rostrum and posterior portion of the lower lips in some pythons and boas. In the Australian python Morelia spilotes, these pits are innervated by the maxillary and mandibular branches of the trigeminal nerve. Structural and neurophysiological evidence indicate that in the pits there are receptors that function as detectors of radiant heat flux.

Relevance of a freshwater cytherid (Crustacea, Ostracoda) to the continental drift hypothesis.

Abstract: BIOLOGISTS concerned with an examination of the continental drift hypothesis usually begin by assuming-biological continuity for their test organisms. This being granted, taxonomic assessments and the resultant biogeographic patterns, especially those of the faunas of southern continents, should provide useful tests for the validity of the hypothesis from a biological point of view—as long as suitable test organisms are used.

Brachial Arterial Blood Pressure in the Lateral Recumbent Position during Pregancy

Abstract: Summary Brachial arterial blood pressures measured by sphygmomanometry fall significantly in most non-pregnant and normal pregnant women when they turn from the supine to right or left lateral recumbent positions. These changes are most marked in the second trimester of pregnancy. This finding is in contrast with the rise in brachial arterial blood pressure and relief of adverse symptoms that occur when pregnant women who develop the supine hypotensive syndrome are turned into a lateral position. Possible mechanisms to account for these blood pressure changes are discussed.

Pupillary changes and reaction time with varied stimulus uncertainty

Abstract: In a reaction-time task, an increase in stimulus uncertainty led to increased RT. This was achieved by varying the number of possible sensory modalities for the signal, changing the length or variability of a warning foreperiod, and concurrently presenting masking noise. At the highest levels of uncertainty, concurrently-monitored pupillary dilation showed an overall flattening of associated response peaks, together with a rise in baseline levels. There was also evidence of expectancy phenomena with nonoccurring, anticipated signals.

Apparent head position as a basis for a visual aftereffect of prolonged head tilt

Abstract: A possible explanation of the visual spatial aftereffect following head tilt with eyes closed is that it is an outcome of a proprioceptive aftereffect of head position. If the upright head is apparently tilted then it might be expected that a vertical line in a dark room would also be apparently tilted. This explanation predicts that the direction and magnitude of the visual and proprioceptive aftereffects would correspond. The second of two experiments showed that the trends of the two aftereffects as a function of head tilt angle were different. It was concluded that the visual aftereffect cannot be explained in terms of a proprioceptive aftereffect.

A criticism of the diffraction theory of some geometrical illusions

Abstract: Chung Chiang (1968) invoked diffraction in the eye to explain Poggendorff’s illusion and extended the discussion to account for other geometrical illusions produced by intersecting lines. But diffraction in the eye cannot account for the displacement and rotation of lines assumed by Chung to produce Poggendorff’s illusion. And even if displacement and rotation do occur, the theory does not account for all illusions of the type considered. I am grateful to R. H. Day and M. Coltheart for critically reading a draft of this paper.

Involvement of neck proprioceptive system in visual after-effect from prolonged head tilt.

Abstract: Judgements of object orientation after prolonged head tilt differ relative to those made before tilt. This visual spatial after-effect was investigated with lateral head tilt relative to the uprigh...

Organomercury compounds. VII. Complexes of arylmercuric halides with bidentate ligands

Abstract: The complexes, C6F5HgXL2 [X = Br or C1; L2 = 2,2'-bipyridyl (bipy), 1,l0-phenanthroline (phen), 3,4,7,8-tetramethyl-1,l0-phenanthroline (tmp), or 2,9-dimethyl-1,l0-phenanthroline (dmp)], C6Cl5HgClL2 (L, = phen, tmp, or dmp), and PhHgClL2 (L2 = phen or tmp), have been prepared, but attempts to prepare PhHgCl bipy or complexes of phenylmercuric bromide were unsuccessful. Evidence that the complexes contain four coordinate mercury has been obtained from infrared spectroscopy. All complexes, except C6Cl5HgCl phen, C6Cl5HgCl dmp, and PhHgCl tmp, undergo complete or partial disproportionation reactions, 2RHgXL2 → L2HgX2 +R2HgL2 (or R2Hg + L2), in boiling benzene. Although disproportionation or low solubility precludes solution studies on the majority of the derivatives, it has been shown that C6F5HgX dmp complexes are monomeric in acetone and that PhHgCl phen undergoes dissociation, PhHgCl phen + PhHgCl + phen, in this solvent. Four-coordinate complexes of mercuric halides with neutral ligands, L,HgX, (L = a neutral unidentate or L, = a neutral bidentate ligand; X = C1, Br, or I), are well kno~n,l-~ but analogous complexes of organomercuric halides, viz. RHgXL,, were unknown prior to this investigation. Reactions of organomercuric halides with ligands generally result in disproportionation, the corresponding diorganomercurial and mercuric halide complex being f~rmed.~-~ In some cases intermediate complexes RHgL+X- have been i~olated~,~ or detected in soluti~n,~-~~ and a 1 : 1 complex of unknown structure between pyridine and cis-2- * Part VI, J. organomet. Chem., in press. Preliminary communications for Part VII: Canty, A. J., Deacon, G. B., and Felder, P. W., Inorg. nzlcl. Chem. Lett., 1967,3,263; Deacon, G. B., and Canty, A. J., Inorg. %ucl. Chem. Lett., 1968, 4, 128. t Chemistry Department, Monash University, Clayton, Vie. 3168. Evans, R. C., Mann, F. G., Peiser, H. S., and Purdie, D., J. chem. Soc., 1940, 1209. Cass, R. C., Coates, G. E., and Hayter, R. G., J. chem. Soc., 1955, 4007. Coates, G. E., and Ridley, D., J. chem. Soc., 1964, 166. Coates, G. E. "Organometallic Compounds." 2nd. Edn, pp. 78-82. (Methuen: London 1960.) Seyferth, D., and Towe, R. H., Inorg. Chem., 1962, 1, 185. Coates, G. E., and Lauder, A., J. chem. Soc., 1965, 1857. Brodersen, K., Chem. Ber., 1957, 90, 2703. Schwarzenbach, G., and Schellenberg, &I., Helv. chim. Acta, 1965, 48, 28. Goggin, P. L., and Woodward, L. A., Trans. Faraday Soc., 1962, 58, 1495. Dessy, R. E., Budde, W. L., and Woodruff, C., J. Am. chem. Soc., 1962, 84, 1172. Aust. J. Chem., 1968, 21, 1757-67

Confounding of psychophysical errors and sensory effects in adjustment measures of spatial aftereffects

Abstract: Measurements of a stereoscopic spatial aftereffect using the method of adjustment without bracketing show that the linear regression of vertical adjustments on starting positions differs between pretests and posttests. The results are given an explanati n in terms of two variables: rapid dissipation of the aftereffect and psychophysical adjustment errors. The implications of the results are discussed.

Empire migration to canada, australia and new zealand, 1910–1929*

Abstract: The fact remains that while our expenditure is upon an unprecedented colossal scale, the result judging by the results achieved before the war when economic conditions within the United Kingdom did not furnish the urgent incentive to emigration which prevails at the moment, is utterly inadequate.

The Influence of Small Additions of Silver on the Structure and Properties of Aged Aluminum Alloys

Abstract: 1. Small additions of silver can exert marked effects on the structure and properties of several aluminum alloys. It is believed that so-called trace elements effects such as this will assume increasing importance in the future because, in many alloy systems, the combinations of major alloying elements have been investigated. 2. The most significant effects of silver additions are observed in alloys based on the Al-Zn-Mg system. On the basis of endurance lives in a range of environments, the stress-corrosion resistance of Al-Zn-Mg-Cu alloys is increased while still maintaining a high level of strength. The addition of silver has been shown to increase the threshold stress for stress-corrosion cracking in an industrial atmosphere but this has not been confirmed for alternate immersion tests in a NaCl solution. Overall, the effects of silver are most marked if the addition of silver is made in conjunction with minor modifications to certain other alloying elements, and a higher ageing temperature is used (e.g. 165°C). 3. There is evidence that the stress-corrosion resistance of welded Al-Zn-Mg alloys is increased if silver is added to the parent metal or solely to the filler rod. 4. Silver additions may modify the structure and properties of aged Al-Mg and Al-Cu-Mg alloys (providing the Mg: Cu ratio is sufficiently high). One possible practical implication of these results is that silver may increase the elevated temperature stability of certain Al-Cu-Mg alloys and preliminary results have been obtained for one experimental composition. 5. From the fundamental viewpoint, it is considered that the effects of silver on the precipitation processes in certain aluminum alloys arise because of an interaction between silver atoms, magnesium atoms, and vacant lattice sites. The interaction is believed to modify the nucleation processes of the particular precipitates although the mechanisms differ depending on the alloy concerned. In alloys based on the Al-Zn-Mg system, silver stimulates nucleation of the existing precipitate whereas silver promotes the formation of a different precipitate in a wide range of Al-Cu-Mg alloys.