Showing papers by "University of Melbourne published in 1992"

Political participation and democracy in Britain

Abstract: Why do some people involve themselves in politics and others not? Which issues are they concerned with? What do they get out of it? Answering such questions is fundamental to understanding political life and the workings of liberal democracies. This book presents the results of one of the most extensive surveys ever undertaken on the levels and patterns of political involvement in Britain. It is based on the findings of a sample survey of nearly 1,600 people across England, Scotland and Wales as well as a further 1,600 men and women and nearly 300 leaders in six specially selected and contrasting communities. These people were asked about the extent to which they had taken political action, particularly at a local level, and the authors found higher levels of participation than previous research has revealed. They analyse these findings in terms of age, gender, social class and education and look at the reactions of local leaders to the efforts people make to influence them.

The Prevention and Treatment of Osteoporosis

Abstract: OSTEOPOROSIS is one of the most important disorders associated with aging.1 , 2 More than 1.5 million Americans have fractures related to osteoporosis each year, with attendant pain, deformity, and loss of independence. The annual cost to the U.S. health care system is at least $10 billion.1 , 2 Because of the aging of the population and increases over time in the incidence of fractures, these already huge costs will more than double over the next 30 years3 unless a comprehensive program of prevention and treatment is initiated soon. The most important preventable cause of fractures is low bone mass. During the course of . . .

The CLP( ℛ ) language and system

Abstract: The CLP( ℛ ) programming language is defined, its underlying philosophy and programming methodology are discussed, important implementation issues are explored in detail, and finally, a prototype interpreter is described.CLP( ℛ ) is designed to be an instance of the Constraint Logic Programming Scheme, a family of rule-based constraint programming languages defined by Jaffar and Lassez. The domain of computation ℛ of this particular instance is the algebraic structure consisting of uninterpreted functors over real numbers. An important property of CLP( ℛ )is that the constraints are treated uniformly in the sense that they are used to specify the input parameters to a program, they are the only primitives used in the execution of a program, and they are used to describe the output of a program.Implementation of a CLP language, and of CLP( ℛ ) in particular, raises new problems in the design of a constraint-solver. For example, the constraint solver must be incremental in the sense that solving additional constraints must not entail the resolving of old constraints. In our system, constraints are filtered through an inference engine, an engine/solver interface, an equation solver and an inequality solver. This sequence of modules reflects a classification and prioritization of the classes of constraints. Modules solving higher priority constraints are isolated from the complexities of modules solving lower priority constraints. This multiple-phase solving of constraints, together with a set of associated algorithms, gives rise to a practical system.

Crop Ecology: Productivity and Management in Agricultural Systems

Abstract: Preface Part I. Farming Systems and Their Biological Components: 1. Agricultural systems 2. Trophic chains 3. Community concepts 4. Genetic resources 5. Development Part II. Physical and Chemical Environments: 6. Aerial environment 7. Soil resources Part III. Production Processes: 8. Nitrogen processes 9. Water relations 10. Photosynthesis 11. Respiration and partitioning Part IV. Resource Management: 12. Soil management 13. Strategies and tactics for rainfed agriculture 14. Water management in irrigated agriculture 15. Energy and labor Part V. Farming, Then, Now and in the Future: 16. Evolution of wheat farming systems in southern Australia 17. Technological change in high-yield agriculture 18. The future of agriculture Species list Conversions and constants useful in crop ecology Index.

The long-term effects of visible light on the eye

Abstract: • The relationship between exposure to sunlight and senile cataract, age-related macular degeneration, pterygium, and climatic droplet keratopathy was examined in 838 watermen who work on the Chesapeake Bay. The presence and severity of lenticular, corneal, and macular changes were assessed by either clinical examination or from stereo macular photographs. From detailed exposure histories, ocular exposure was estimated for three bands of visible radiation—violet (400 to 450 nm), blue (400 to 500 nm), or all visible (400 to 700 nm)—as well as for UV-A (320 to 340 nm) and UV-B (290 to 320 nm). The results with each band of visible radiation were similar. Neither cortical nor nuclear cataract was associated with ocular exposure to blue or all visible radiation, but pterygium and climatic droplet keratopathy were more common with higher exposures. Compared with age-matched controls, patients with advanced age-related macular degeneration (geographic atrophy or disciform scarring) had significantly higher exposure to blue or visible light over the preceding 20 years (odds ratio, 1.36 [1.00 to 1.85]) but were not different in respect to exposure to UV-A or UV-B. These data suggest that high levels of exposure to blue or visible light may cause ocular damage, especially later in life, and may be related to the development of age-related macular degeneration.

Dietary intake of fiber and decreased risk of cancers of the colon and rectum: Evidence from the combined analysis of 13 case-control studies

Abstract: BACKGROUND Colorectal cancer is a major public health problem in both North America and western Europe, and incidence and mortality rates are rapidly increasing in many previously low-risk countries. It has been hypothesized that increased intakes of fiber, vitamin C, and beta carotene could decrease the risk of colorectal cancer. PURPOSE The objective of this study was to examine the effects of fiber, vitamin C, and beta-carotene intakes on colorectal cancer risk in a combined analysis of data from 13 case-control studies previously conducted in populations with differing colorectal cancer rates and dietary practices. The study was designed to estimate risks in the pooled data, to test the consistency of the associations across the studies, and to examine interactions of the effects of the nutrients with cancer site, sex, and age. METHODS Original data records for 5287 case subjects with colorectal cancer and 10,470 control subjects without disease were combined. Logistic regression analysis was used to estimate relative risks and confidence intervals for intakes of fiber, vitamin C, and beta carotene, with the effects of study, sex, and age group being adjusted by stratification. RESULTS Risk decreased as fiber intake increased; relative risks were 0.79, 0.69, 0.63, and 0.53 for the four highest quintiles of intake compared with the lowest quintile (trend, P < .0001). The inverse association with fiber is seen in 12 of the 13 studies and is similar in magnitude for left- and right-sided colon and rectal cancers, for men and for women, and for different age groups. In contrast, after adjustment for fiber intake, only weak inverse associations are seen for the intakes of vitamin C and beta carotene. CONCLUSION This analysis provides substantive evidence that intake of fiber-rich foods is inversely related to risk of cancers of both the colon and rectum. IMPLICATIONS If causality is assumed, we estimate that risk of colorectal cancer in the U.S. population could be reduced about 31% (50,000 cases annually) by an average increase in fiber intake from food sources of about 13 g/d, corresponding to an average increase of about 70%.

Estimating two-dimensional frequencies by matrix enhancement and matrix pencil

Abstract: A new method, called the matrix enhancement and matrix pencil (MEMP) method, is presented for estimating two-dimensional (2-D) frequencies. In the MEMP method, an enhanced matrix is constructed from the data samples, and then the matrix pencil approach is used to extract out the 2-D sinusoids from the principal eigenvectors of the enhanced matrix. The MEMP method yields the estimates of the 2-D frequencies efficiently, without solving the roots of a 2-D polynomial or searching in a 2-D space. It is shown that the MEMP method can be faster than a 2-D FFT method if the number of the 2-D sinusoids is much smaller than the data set. Simulation results are provided to show that the accuracy of the MEMP method can be very close to the Cramer-Rao lower bound. >

Leading the self-managing school

Abstract: Part 1 A new context and an updated model for self-management: the new realities in education updating the model what we now know about leadership. Part 2 Leadership in the self-managing school: cultural leadership - creating and sustaining a culture of excellence strategic leadership - taking charge of the agenda educational leadership - nurturing a learning community responsive leadership - coming to terms with accountability. Part 3 Transforming our schools: transforming the system - avoiding the perils of restructuring schools in transition - a vision for the 1990s.

Spectrofluorimetric assessment of the surface hydrophobicity of proteins.

Abstract: The equilibrium binding of the apolar fluorescent dye 1-anilinonaphthalene-8-sulphonate (ANS) to bacteriorhodopsin, BSA, chicken egg lysozyme, ovalbumin, porcine somatotrophin (PST) and bovine pancreatic ribonuclease (RNAase) was quantitatively evaluated using Scatchard- and Klotz-plot analyses. On the basis of the average association constant for ANS binding sites (Ka), the proteins could be ranked in order of surface hydrophobicity as: Bacteriorhodopsin greater than BSA greater than ovalbumin greater than PST greater than lysozyme greater than RNAase. The number of protein-ANS binding sites was determined as 54, 10, 3, 1, 2 and 1 respectively. The ANS-based assessment of the surface hydrophobicity of these proteins was generally in agreement with the average hydrophobicity based on amino acid sequence [Bigelow (1967) J. Theor. Biol. 16, 187-211], except for results with PST and ovalbumin. The proteins were also analysed by reversed-phase h.p.l.c. using C1 and C8 columns. There was no significant correlation between ANS and reversed-phase-h.p.l.c. assessment of hydrophobicity, with the results obtained by h.p.l.c. being dependent upon the column used. ANS-based measurement of surface hydrophobicity appears to be the most appropriate means for assessing proteins such as to reflect their overall three-dimensional structure in solution.

Reaction to trauma: a cognitive processing model.

Abstract: We integrated existing cognitive processing models of posttrauma reactions into a longitudinal model. Data were obtained after a multiple shooting in a city office block. The subject group comprised 158 office workers who were in the building at the time of the shootings. The methodology of this research was a repeated measures survey, with data collection at 4, 8, and 14 months posttrauma. Measures included the Impact of Events Scale (IES) and the Symptom Checklist-90-Revised. A path analysis was performed with the IES as an indication of cognitive processing. Intrusion and avoidance were shown to mediate between exposure to trauma and symptom development. Intrusion was also found to be negatively related to subsequent symptom levels. The findings provide provisional support for a cognitive processing model.

Nitrergic transmission: nitric oxide as a mediator of non-adrenergic, non-cholinergic neuro-effector transmission.

Abstract: SUMMARY 1. The possibility that transmission at some non-adrenergic, non-cholinergic (NANC) neuro-effector junctions is mediated by nitric oxide (NO) arose from the discoveries that NO mediated the effects of nitrovasodilator drugs and that endothelium-derived relaxing factor (EDRF) was NO or a NO-yielding substance. 2. NO donated by nitrovasodilator drugs or formed by endothelial cells activates soluble guanylate cyclase in smooth muscle and the consequent increase in cyclic guanosine monophosphate (cGMP) results in relaxation. The relaxations produced by stimulation of some NANC nerves are also due to a rise in cGMP. 3. The biosynthesis of NO by oxidation of a terminal guanidino nitrogen of l-arginine is inhibited by some NG-substituted analogues of l-arginine. These substances block EDRF formation by NO synthase and endothelium-dependent vasodilatation, and the blockade is overcome by l-arginine 4. NANC relaxations in some tissues are blocked by NG-substituted analogues of l-arginine and restored by l-arginine. Other agents that affect endothelium-dependent vasodilator responses produce corresponding changes in responses to stimulation of these NANC nerves. Such observations indicate that transmission is mediated by NO: we have termed this mode of transmission nitrergic. 5. There is evidence for nitrergic innervation of smooth muscle in the gastrointestinal tract, genitourinary system, trachea and some blood vessels (penile and cerebral arteries). 6. The recognition of a mediator role for NO in neurotransmission calls for reconsideration of previously accepted generalizations about mechanisms of transmission. 7. Studies on nitrergic transmission will provide new insights into physiological control mechanisms and pathophysiological processes and may lead to new therapeutic developments.

Conformal weights of RSOS lattice models and their fusion hierarchies

Abstract: The finite-size corrections, central charges c and conformal weights Δ of L-state restricted solid-on-solid lattice models and their fusion hierarchies are calculated analytically This is achieved by solving special functional equations, in the form of inversion identity hierarchies, satisfied by the commuting row transfer matrices at critically The results are all obtained in terms of Rogers dilogarithms The RSOS models exhibit two distinct critical regimes For the regime III/IV critical line, we find c = [3p/(p + 2)][1 − 2(p + 2)/r(r − p)] where L = r − 1 is the number of heights and p = 1, 2, … is the fusion level The conformal weights are given by a generalized Kac formula Δ = {[rt − (r − p)s]2 − p2}/ 4pr(r − p) + (s0 − 1)(p − s0 + 1)/ 2p(p + 2) where s = 1, 2, …, r − 1; t = 1, 2, …, r − p − 1; 1 ⩽ s0 ⩽ p + 1 and s0 − 1 = ±(t − s) mod 2p For p = 1, 2, these models are described by the unitary minimal conformal series and the discrete superconformal series, respectively For the regime I/II critical line, we obtain c = 2(N − 1)/(N + 2) and Δ = l(l + 2)/4(N + 2) − m2/4N for the conformal weights, independent of the fusion level p, where N = L − 1, l = 0, 1, …, N and m = −l, −l + 2, …, l − 2, l In this critical regime the models are described by ZN parafermion theories

Mapping of angiotensin II receptor subtype heterogeneity in rat brain

Abstract: Angiotensin II (Ang II) exerts a number of central actions on fluid and electrolyte homeostasis, autonomic activity, and neuroendocrine regulation. In order to evaluate likely sites where these actions are mediated, Ang II receptor binding was localized in rat brain by in vitro autoradiography with the aid of the antagonist analogue l25I-[Sar1, Ile8]Ang II. Two subtypes of Ang II receptor have been identified using recently developed peptide and nonpeptide antagonists. In the periphery, the receptor subtypes differ in distribution, second messenger coupling, and function. Brain Ang II receptor subtypes were therefore differentiated into AT-1 (type I) and AT-2 (type II) subtypes by using unlabelled nonpeptide antagonists specific for the two Ang II subtypes. AT-1 binding was determined to be that inhibited by Dup 753 (10 μM) and AT-2 binding to be that inhibited by PD 123177 (10 μM). The reducing agent dithiothreitol (DTT) decreased binding to AT-1 receptors and enhanced binding to AT-2 receptors. Many brain structures, such as the vascular organ of the lamina terminalis, subfornical organ, median preoptic nucleus, area postrema, nucleus of the solitary tract, and dorsal motor nucleus of the vagus, which are known to be related to the central actions of Ang II, contain exclusively AT-1 Ang II receptors. By contrast, the locus coeruleus, ventral and dorsal parts of lateral septum, superior colliculus and subthalamic nucleus, many nuclei of the thalamus, and nuclei of the inferior olive contain predominantly AT-2 Ang II receptors. The detailed binding characteristics of each subtype were determined by competition studies with a series of analogues of angiotensin and antagonists. The pharmacological specificity obtained in rat superior colliculus and the nucleus of the solitary tract agreed well with published data on AT-1 and AT-2 receptors, respectively. There was a high degree of correlation between the distribution of Ang II binding sites with published data on Ang II-immunoreactive fields and on the sites of Ang II-responsive neurons. The present study also reveals pharmacological heterogeneity of brain Ang II receptors. The subtype-specific receptor mapping described here is relevant to understanding the role of angiotensin peptides in the central nervous system and newly discovered central actions of nonpeptide Ang II receptor antagonists.

Associations between research and teaching in Australian higher education

Abstract: This article describes results of an empirical investigation of the relationship between research and undergraduate teaching in Australian higher education. Two research indexes (weighted number of publications, and number of research activities) were used. Scores on a Likert-type scale of reported commitment to teaching undergraduate students formed the main criterion of teaching effectiveness. This was supplemented by student ratings in one of the aggregate-level analyses. The results revealed typically no relation or a negative relation between teaching and research at the level of the individual and at the level of the department, across all subject areas. The only exceptions concerned one group of former colleges of education. Further analysis by staff self-rating of academic quality showed that there existed one group of staff, mainly in the universities, who were committed to teaching and highly active researchers. However, the data did not support a causal interpretation of the association. It is concluded that there is no evidence in these results to indicate the existence of a simple functional association between high research output and the effectiveness of undergraduate teaching. Some implications for policy and student course choice are discussed.

One parent, one language

Abstract: This volume examines the relationship between young children's degrees of bilingualism and features of the verbal input which these children receive from their parents. In particular, it seeks to explore the following question: to what extent are families who follow the 'one parent-one language' principle and whose children become active bilinguals this way, different from families who take the same approach but whose children never develop an active command of the minority language? Case studies of six first-born children growing up with German and English were done during the children's third year of life. The input the children received was examined for parents' consistency of language choice, parents' insistence that the children use the appropriate language, parents' sensitivity towards the children's interactional and attentional needs, and parents' orientation towards the teaching of formal aspects of the linguistic system. The findings support the notion that raising one's children bilingually according to the 'one parent-one language' principle involves great efforts on the side of the minority language-speaking parent. Importantly, they indicate that these efforts must be invested in the child's education turn-by-turn.

Identification of murine homologues of the Drosophila son of sevenless gene: potential activators of ras.

Abstract: Several findings suggest that signals from tyrosine kinases are transduced, at least in part, through ras proteins. These findings include (i) blockage of the transforming activity of constitutively active tyrosine kinases by inhibiting ras function and (ii) genetic screens in Caenorhabditis elegans and in Drosophila that identified ras genes as downstream effectors of tyrosine kinases. The recently isolated Drosophila gene Son of sevenless (Sos) is postulated to act as a positive regulatory link between tyrosine kinase and ras proteins by catalyzing exchange of GDP for GTP on ras protein. Such exchange proteins have been reported in extracts of mammalian cells but have not been previously characterized at a molecular level. As Sos appears to function in this role in Drosophila, we sought to isolate a vertebrate counterpart(s). We have characterized two widely expressed murine genes with a high degree of homology to Sos. Hybridization with human DNA and RNA indicates a high degree of conservation of these genes in other vertebrates.

Co-localization of nitric oxide synthase immunoreactivity and NADPH diaphorase staining in neurons of the guinea-pig intestine.

Abstract: Neuronal nitric oxide synthase (NOS), an enzyme capable of synthesizing nitric oxide, appears to be identical to neuronal NADPH diaphorase. The correlation was examined between NOS immunoreactivity and NADPH diaphorase staining in neurons of the ileum and colon of the guinea-pig. There was a one-to-one correlation between NOS immunoreactivity and NADPH diaphorase staining in all neurons examined; even the relative staining intensities obtained were similar with each technique. To determine whether pharmacological methods could be employed to demonstrate that NADPH diaphorase staining was due to the presence of NOS, tissue was pre-treated with NG-nitro-L-arginine, a NOS inhibitor, or L-arginine, a natural substrate of NOS. In these experiments on unfixed tissue, it was necessary to use dimethyl thiazolyl tetrazolium instead of nitroblue tetrazolium as the substrate for the NADPH diaphorase histochemical reaction. Neither treatment caused a significant decrease in the level of NADPH diaphorase staining, implying that arginine and NADPH interact at different sites on the enzyme.

The Tyranny of a Team Ideology

Abstract: People at work have been tyrannized by a team ideology based on the use of work groups as a key to effective organizational performance. The hegemony of this ideology has created an obsession with teams in workplaces governed by oppress ive stereotypes of what teams should be like and how they should behave. This paper examines four elements of the prevailing team ideology — the way work in groups is defined, links between individual motivation and organizational per formance, views of leadership, and the effects of power, conflict and emotion in work groups. Some alternative perspectives on team behaviour elucidate the ways in which the prevailing paradigm ultimately hinders groups and tyrannizes the individual team member — by camouflaging coercion and conflict with the appearance of consultation and cohesion. Examination of the limits and effects of the ideology provide the basis for an alternative understanding of the strengths, constraints and complexities of group work.

Evolution of sex determination and the Y chromosome: SRY -related sequences in marsupials

Abstract: IN mammals, testis determination is under the control of the testis-determining factor borne by the Y chromosome1,2. SRY, a gene cloned from the sex-determining region of the human Y chromosome, has been equated with the testis-determining factor in man3–5 and mouse6,7. We have used a human SRY probe to identify and clone related genes from the Y chromosome of two marsupial species. Comparisons of eutherian and metatherian Y-located SRY sequences suggest rapid evolution of these genes, especially outside the region encoding the DNA-binding HMG box. The SRY homologues, together with the mouse Ubely homologues8, are the first genes to be identified on the marsupial Y chromosome.

Franz Volhard Lecture. Renin-angiotensin system: a dual tissue and hormonal system for cardiovascular control.

Abstract: BACKGROUND The renin-angiotensin system is both a circulating and a local tissue hormonal system. All components of the renin-angiotensin system have been found in important cardiovascular structures, including the heart, vessels, brain, kidney and adrenal gland. The angiotensin converting enzyme (ACE) is the final step in the enzymatic cascade of the renin-angiotensin system, which converts angiotensin in both the circulation and the tissues. IMPORTANCE OF ACE CATALYTIC SITES ACE is predominantly an ectoenzyme with a bilobed homodimer extracellular portion, a short transmembrane span and a small intracellular extension. ACE contains two catalytic sites, one on each lobe. There is evidence that these catalytic sites may differ in several properties and may have different conformational requirements. This raises the possibility that there may be different endogenous substrates for each site and it may be feasible to design more specific ACE inhibitors that inhibit only one catalytic site. CARDIOVASCULAR ROLE OF LOCAL RENIN-ANGIOTENSIN SYSTEM: The physiological cardiovascular functions of the tissue renin-angiotensin system may include regulation of regional blood flow, modulation of local sympathetic activity and interaction with the endothelium. There is increasing evidence that the local renin-angiotensin system may be involved in the maintenance of cardiovascular structure and repair. ACE is increased in many forms of vascular and cardiac hypertrophy and the administration of ACE inhibitors has led to regression of hypertrophy. Many of the beneficial effects of ACE inhibitors may be due to inhibition of the local renin-angiotensin system. ACE INHIBITION FOLLOWING MYOCARDIAL INJURY The local renin-angiotensin system may also be involved in the response to injury and in the inflammatory response. ACE is known to be increased in granulomas, it is expressed on monocytic macrophages and fibroblasts and many of the peptides involved in the inflammatory response (bradykinin, substance P, enkephalins) can act as ACE substrates. Following an acute myocardial infarct, ACE is increased in the myocardial scar and in the hypertrophying cardiac muscle. This provides a possible mechanism for the beneficial effect of ACE inhibitors in postmyocardial infarction trials. NON-CARDIOVASCULAR SYSTEM: Neither the function of the renin-angiotensin system in the brain and non-cardiovascular tissues nor its role in the pathophysiology of hypertension are known as yet.

A new portable sound processor for the University of Melbourne/Nucleus Limited multielectrode cochlear implant.

Abstract: A new processor, called the spectral maxima sound processor (SMSP), has been developed for the University of Melbourne/Nucleus Limited multielectrode cochlear implant. The SMSP analyses sound signals by means of a bandpass filterbank having 16 channels which are allocated tonotopically to the implanted electrodes. Every 4 ms, typically, the six channels with the largest amplitudes are selected, and six corresponding electrodes are activated. In an ongoing study the performance of the SMSP is being compared with that of the Mini Speech Processor (MSP). Some results of speech perception tests from the first two SMSP users are presented, in which scores for the recognition of vowels, consonants, and words all showed significant increases over the corresponding MSP scores.

Factors predicting postoperative sentence scores in postlinguistically deaf adult cochlear implant patients.

Abstract: A sample of 64 postlinguistically profoundly to totally deaf adult cochlear implant patients were tested without lipreading by means of the Central Institute for the Deaf (CID) sentence test 3 months postoperatively. Preoperative promontory stimulation results (thresholds, gap detection, and frequency discrimination), age, duration of profound deafness, cause of deafness, lipreading ability, postoperative intracochlear thresholds and dynamic ranges for electrical stimulation, depth of insertion of the electrode array into the scala tympani, and number of electrodes in use were considered as possible factors that might be related to the postoperative sentence scores. A multiple regression analysis with stepwise inclusion of independent variables indicated that good gap detection and frequency discrimination during preoperative promontory testing, larger numbers of electrodes in use, and greater dynamic ranges for intracochlear electrical stimulation were associated with better CID scores. The CID scores te...

Decision Problems for Groups — Survey and Reflections

Abstract: This is a survey of decision problems for groups, that is of algorithms for answering various questions about groups and their elements. The general objective of this area can be formulated as follows: Objective: To determine the existence and nature of algorithms which decide local properties — whether or not elements of a group have certain properties or relationships; global properties— whether or not groups as a whole possess certain properties or relationships.

A study of the fine scale motions of incompressible time-developing mixing layers

Abstract: This work is an extension of a project conducted at the previous CTR summer program and was reported by Chen et al. (1990). In that program, the geometry and topology of the dissipating motions in a variety of shear flows was examined. All data was produced by direct numerical simulations (DNS). The partial derivatives of the velocity field were determined at every grid point in the flow and various invariants and related quantities were computed from the velocity gradient tensor. Motions characterized by high rates of kinetic energy dissipation and high enstrophy were of particular interest. Scatter diagrams of the invariants were mapped out and interesting and unexpected patterns were seen. Each type of shear layer produced its own characteristic scatter plot. In the present project, attention is focused on the incompressible plane mixing layer, and the scatter diagrams are replaced with more useful joint probability density contours. Comparison of the topology of the dissipating motions of flows at different Reynolds numbers are made. Also, plane mixing layers at the same Reynolds number but with different initial conditions are compared.