University of New South Wales

About: University of New South Wales is a education organization based out in Sydney, New South Wales, Australia. It is known for research contribution in the topics: Population & Poison control. The organization has 51197 authors who have published 153634 publications receiving 4880608 citations. The organization is also known as: UNSW & UNSW Australia.

Anatomy of the serotonergic system.

Abstract: The serotonergic (5-hydroxytryptaminergic, 5-HT) system is one of the diffusively organized projection systems of the brain. Although the presence of serotonin itself was demonstrated in the brain more than thirty years ago’,* the full description of its neuronal localization and projections has only become possible with the availability of the histoflu~rescence’~~ and immunohistochemical’ techniques. Indeed it was only by the use of antibodies against serotonin that the detailed anatomy and topography of the serotonergic cells and their projections throughout the brain could be described. Therefore, the description of the 5-HT system below is based entirely on immunohistochemical data although some reference is made to other anatomical observations based on traditional neurohistological and histochemical techniques. The 5-HT system consists of a morphologically diverse group of neurons the cell bodies of which are located in the brainstem raphe nuclei and some regions of the reticular formation, and complex axonal systems which innervate virtually all regions of the central nervous system, but with particular density the cerebral cortex, limbic structures, basal ganglia, many regions of the brainstem and the gray matter of the spinal cord.’-’’ This review discusses, from a structural as well as hodological viewpoint, the organizational principles of the 5-HT system. Since several detailed reviews are available on the serotonergic system, the repetition of all data is largely avoided. Rather, a more salient description of the general features of the brainstem 5-HT neurons and their terminal fields is attempted. All investigators of the mammalian brain have agreed on the finding that the 5-HT system consists of two distinct subdivisions: a rostral division, with cell bodies localized in the midbrain and rostral pons and providing projections to the forebrain, and a caudal division, located primarily in the medulla oblongata, with major descending projections directed principally to the spinal cord.”.” Target areas within the brainstem itself and in the cerebellum are shared by these two divisions. The description given below is in part based on original experimental material (with particular reference to the human brain) prepared to illustrate the general morphology of the serotonergic neurons. For this reason, a brief description of the methodology used in our laboratory for the demonstration of the 5-HT neurons is given below.

Physiological factors associated with falls in an elderly population.

Abstract: OBJECTIVE: To determine whether a battery of 13 sensorimotor, vestibular, and visual tests discriminates between elderly fallers and elderly non-fallers. DESIGN: One-year prospective study. SETTING: Conducted at a 124-bed Hostel for Aged Persons, in Sydney, Australia. PARTICIPANTS: Ninety-five persons aged between 59 and 97 years (mean age 82.7 years) took part in the study. Of the 29 non-participants, four were ill, five were absent (on holidays, etc), and 20 declined. Residents were generally independent in activities of daily living although personal care assistance was available. RESULTS: Eighty-four participants were available for follow-up. In the follow-up year, 40 subjects experienced no falls, 11 subjects fell one time only, 33 residents fell on two or more occasions. There was a total of 145 falls. Discriminant function analysis identified proprioception in the lower limbs visual contrast sensitivity, ankle dorsiflexion strength, reaction time, and sway with the eyes closed as the variables that significantly discriminated between subjects who experienced multiple falls and subjects who experienced no falls or one fall only. This procedure correctly classified 79% of subjects into multiple faller or non-multiple faller groups. Quadriceps strength was poorer in the multiple fallers compared with the non-fallers and once-only fallers, although the difference was not statistically significant. There was little difference in the mean scores for the tests of vestibular function in the non-fallers, once-only fallers, and multiple fallers. CONCLUSION: It appears that this approach highlights some key physiological factors that predispose elderly individuals to falls. Language: en

Discrete particle simulation of particle–fluid flow: model formulations and their applicability

Abstract: The approach of combining computational fluid dynamics (CFD) for continuum fluid and the discrete element method (DEM) for discrete particles has been increasingly used to study the fundamentals of coupled particle–fluid flows. Different CFD–DEM models have been used. However, the origin and the applicability of these models are not clearly understood. In this paper, the origin of different model formulations is discussed first. It shows that, in connection with the continuum approach, three sets of formulations exist in the CFD–DEM approach: an original format set I, and subsequent derivations of set II and set III, respectively, corresponding to the so-called model A and model B in the literature. A comparison and the applicability of the three models are assessed theoretically and then verified from the study of three representative particle–fluid flow systems: fluidization, pneumatic conveying and hydrocyclones. It is demonstrated that sets I and II are essentially the same, with small differences resulting from different mathematical or numerical treatments of a few terms in the original equation. Set III is however a simplified version of set I. The testing cases show that all the three models are applicable to gas fluidization and, to a large extent, pneumatic conveying. However, the application of set III is conditional, as demonstrated in the case of hydrocyclones. Strictly speaking, set III is only valid when fluid flow is steady and uniform. Set II and, in particular, set I, which is somehow forgotten in the literature, are recommended for the future CFD–DEM modelling of complex particle–fluid flow.