115 resultados para covalent and non-covalent interactions

em Deakin Research Online - Australia


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Cross-strand pair correlations are calculated for residue pairs in antiparallel β-sheet for two cases: pairs whose backbone atoms are hydrogen bonded together (H-bonded site) and pairs which are not (non-H-bonded site). The statistics show that this distinction is important. When glycine is located on the edge of a sheet, it shows a 3:1 preference for the H-bonded site. Thestrongest observed correlations are for pairs of disulfide-bonded cystines, many of which adopt a close-packed conformation with each cystine in a spiral conformation of opposite chirality to its partner. It is likely that these pairs are a signature for the family of small, cystine-rich proteins. Most other strong positive and negative correlations involve charged and polar residues. It appears that electrostatic compatibility is the strongest factor affecting pair correlation. Significant correlations are observed for β- and γ-branched residues inthe non-H-bonded site. An examination of the structures showsa directionality in side chain packing. There is a correlation between (1) the directionality in the packing interactions of non-H-bonded β- and γ-branched residue pairs, (2) the handedness of the observed enantiomers of chiral β-branched side chains, and (3) the handedness of the twist of β-sheet. These findings have implications for the formation of β-sheets during protein folding and the mechanism by which the sheet becomes twisted

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Immobilization of catechol derivatives on GC electrode surfaces can be performed by in situ generation and reduction of nitrocatechol. We present the oxidative nitration of catechol in the presence of nitrous acid followed by electrochemically reduction of the generated nitro aromatic group to the corresponding amine group and its conversion to diazonium cation at the electrode surface to yield a surface covalently modified with catechol. In this manner, some derivatives of catechol can be immobilized on the electrode surface. Whole of the process is carried out in Triethylammonium acetate ionic liquid as an inert and neutral medium (pH∼7.0). Surface coverage can be easily controlled by the applied potential, time and concentration of catechol. After modification, the electrochemical features of modified surface have been studied. Also modified GC electrode exhibited remarkable catalytic activity in the oxidation of NADH. The catalytic currents were proportional to the concentration of NADH over the range 0.01-0.80 mM. This condition can be used for modification of GC surfaces by various aromatic molecules for different application such as design of sensors and biosensors. © 2014 Elsevier Ltd. All rights reserved.

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BACKGROUND: Dementia residential facilities can be described as traditional or non-traditional facilities. Non-traditional facilities aim to utilise principles of environmental design to create a milieu that supports persons experiencing cognitive decline. This study aimed to compare these two environments in rural Australia, and their influence on residents' occupational engagement. METHODS: The Residential Environment Impact Survey (REIS) was used and consists of: a walk-through of the facility; activity observation; interviews with residents and employees. Thirteen residents were observed and four employees interviewed. Resident interviews did not occur given the population diagnosis of moderate to severe dementia. Descriptive data from the walk-through and activity observation were analysed for potential opportunities of occupational engagement. Interviews were thematically analysed to discern perception of occupational engagement of residents within their facility. RESULTS: Both facilities provided opportunities for occupational engagement. However, the non-traditional facility provided additional opportunities through employee interactions and features of the physical environment. Interviews revealed six themes: Comfortable environment; roles and responsibilities; getting to know the resident; more stimulation can elicit increased engagement; the home-like experience and environmental layout. These themes coupled with the features of the environment provided insight into the complexity of occupational engagement within this population. CONCLUSION: This study emphasises the influence of the physical and social environment on occupational engagement opportunities. A non-traditional dementia facility maximises these opportunities and can support development of best-practice guidelines within this population.

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By definition, a driver mutation confers a growth advantage to the cancer cell in which it occurs, while a passenger mutation does not: the former is usually considered as the engine of cancer progression, while the latter is not. Actually, the effects of a given mutation depend on the genetic background of the cell in which it appears, thus can differ in the subclones that form a tumor. In addition to cell-autonomous effects generated by the mutations, non-cell-autonomous effects shape the phenotype of a cancer cell. Here, we review the evidence that a network of biological interactions between subclones drives cancer cell adaptation and amplifies intra-tumor heterogeneity. Integrating the role of mutations in tumor ecosystems generates innovative strategies targeting the tumor ecosystem's weaknesses to improve cancer treatment.

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Numerous theories have been formulated in an attempt to explain the psychological differences between violent offenders and non-offenders. Constructs that have emerged as salient in such scholarship include anger expression, social problem solving, locus of control, attitudes toward women, impulsivity and temper. Although a considerable amount of sound research has been conducted into 'violent offending' per se, in general terms, research into family and domestic violence is yet to be as methodologically and theoretically rigorous. In an attempt to link these areas of work, and to identify the risk factors (or 'criminogenic needs') of specific sub-groups of male offenders, this research compared: (I) property offenders, (2) those who had been· 'violent against strangers', (3) those who had been 'violent against intimates' and (4) non-offenders. In an effort to address one of the shortcomings of prior research, potentially confounding variables such as age, education level cultural identity, and socio-economic status were controlled for in an effort to arrive at more meaningful representations of each offender group's specific psychological deficits and abundances. A number of differences were highlighted between the groups, but few of these remained after demographic
covariates were controlled for. This paper details the nature of these differences, while also proposing that future studies adopt a similar methodology.

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This study examined the validity and reliability of survey items measuring one-week recall of physical activity (PA) and examined differences by weight status. A sub-aim of the study was to objectively assess the intensity of activity that most closely matches self-report. A questionnaire was administered to adults twice, three days apart. It was again administered after subjects wore a MTI/CSA accelerometer for seven days (n = 118). Several metabolic equivalent (MET) thresholds were applied to the accelerometer data. Agreement between test and re- test estimates of sufficient physical activity for health benefits (150 min/week) was high (% agreement > 90%). Correlations (rho) between total reported PA (mins/day) and accelerometer data were 0.29 (p < 0.05) among men and 0.25 (p < 0.05) among women. Among men, self- reported duration of moderate PA (3-5.9 METS) and accelerometer data were significantly correlated (rho = 0.40, p < 0.01), with no differences by weight status. Among women, a significant relationship was found only for those who were not overweight (rho = 0.52, p < 0.001). A significant correlation between self-reported duration of vigorous PA (6+ METS) and accelerometer data was only found for overweight men (rho = 0.40, p < 0.05). When lower MET thresholds were applied to the accelerometer data, women's reported duration of moderate-intensity PA was most strongly correlated with moderate PA (accelerometer) defined as 2.0-5.9 METS (rho = 0.39, p < 0.01). The recall instrument provides a consistent measure of physical activity and validation coefficients were similar to those obtained for other physical activity recall questionnaires. However, the ability to measure PA by self-report may vary by weight status.

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Sociocultural messages about the ideal body build have been studied predominantlyamong White adolescent girls. In the current study we examined the relationships between perceived sociocultural influences, body image concerns, and body change strategies among 47 (22 boys and 25 girls) Indigenous Australian adolescents. These relationships were compared to those from 47 non-Indigenous adolescents (predominantly from an Anglo-Saxon background), who were matched on gender, age, and school grade. Overall, the sociocultural influences were found to be associated with body image concerns and body change strategies among both cultural groups. The only exception was that the sociocultural influences were not associated with the Indigenous girls levels of body dissatisfaction or body image importance. These findings are discussed in relation to past studies of White and Black girls.

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Under the Federal Government's CLERP 9 legislation, expected at the time of writing to come into force in July 2004, personal liability will be introduced for the first time under the continuous disclosure regime. Individuals who are 'involved' in a failure to immediately disclose materially price sensitive information to the market will be subject to a civil penalty, in addition to the company being liable. According to the author, the introduction of personal liability per se is not contentious and indeed is a favourable change; what is questionable, however, is whether 'involvement' in a contravention is the appropriate test for imposing personal liability in relation to breaches of the continuous disclosure provisions. Based on the case law to date on the meaning of 'involved', there is particular uncertainty as to whether an individual would need to have actual knowledge that non-disclosed information is 'materially price sensitive' in order to satisfy the test of 'involved' in the context of continuous disclosure, or whether mere knowledge that the information has not been disclosed would be sufficient. This uncertainty arises due to the vague concept of 'essential matters' which the courts have developed as a test for what degree of knowledge a person needs to have in order to be 'involved'. The author argues that all the confusion as to what 'involved' means could be addressed by removing the word 'essential' from the dialogue, so that the test of 'involvement' would simply be based on whether the particular person had actual knowledge of each of the factual elements constituting the offence.

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In 2004 The High Court handed down a number of decisions concerning detention imposed for purposes allegedly unrelated to punishment. This paper outlines the way the Federal Constitution restricts (and also facilitates) the imposition of "non punitive detention" by our governments. Such laws (as passed by the Federal Legislature) are constitutionally valid provided they can be characterised as falling within a legislative head of power under  section 51 off he Constitution. The power to detain for non punitive purposes can be reposed by the Legislature in the either the Executive or Judicial arms of government. Detention by the Executive is non punitive (and therefore does not offend the separation of powers) even though it involves a deprivation of liberty, provided it is imposed for “legitimate non punitive purposes”.  Legitimacy is in turn determined by reference to the section 51 heads of power. Detention for non punitive purposes by the judicial arm of government is constitutionally valid provided that (i) a “judicial process ” is adopted and (ii) (arguably) there is some link (albeit tenuous) with a previous finding of criminal guilt. The continuing existence of the “constitutional immunity ”from being detained by other than judicial order identified by the High Court in its 1992 decision in Lim v Minister for Immigration is called into question.

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We address the blind equalization of finite-impulse-response (FIR), multiple-input multiple-output (MIMO) channels excited by constant modulus (CM) signals. It is known that the algorithms based on the constant modulus (CM) criterion can equalize an FIR MIMO channel that is irreducible and column-reduced. We show in this paper that the CM property of signals can be exploited to construct a zero-forcing equalizer for a non-irreducible and non-column-reduced channel. We also give a lower bound for the order of the equalizer. Simulation examples demonstrate the proposed result.

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This article presents a qualitative study of the indigenous Australian perspective on reconciliation with nonindigenous Australia, with a focus on the role of an apology for the oppression and violence perpetrated by nonindigenous Australians, and forgiveness on the part of indigenous Australians. A brief historical analysis of the relationship between Aborigines and waves of settlers is presented to demonstrate the extent of the wrong that was perpetrated against Aborigines and the need for social as well as practical reconciliation in the current context. It is argued that negotiated forgiveness is a concept that is pertinent to the discussion of reconciliation, because it requires a dialogue between the parties and ultimately for the wrongdoer to accept accountability and responsibility for offending actions, thereby opening the door for forgiveness and, ultimately, possible reconciliation. It is suggested that a first step in the required reconciliation dialogue is an apology, but the issue of who should give and receive an apology is a complex one. The issue of who should forgive and who should be forgiven is shown to be similarly complex. Qualitative analysis of interview data from 10 participants indicated that at this point in time, forgiveness might not be salient to the indigenous population, whose primary focus is more on the matter of an apology. This suggests that negotiated forgiveness and reconciliation will remain elusive goals until the matter of an apology is resolved.

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The crystal structure of the novel methylene-bridged tetraorganodistannoxane {[Ph(HO)SnCH2Sn(I)Ph]O}4 (1) depends on the solvent it is crystallised from and is controlled by hydrogen bridges and interhalogen interactions.


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Objectives:
To compare the injury profiles of the Indigenous population in New South Wales with that of the non-Indigenous population.
Design and setting:
Descriptive analysis of NSW Health data obtained from the Health Outcomes Information and Statistical Toolkit (HOIST) database. Hospitalisation data were collected for the period 1 July 1999 to 30 June 2003. Mortality data were collected for the period 1 January 1999 to 31 December 2002.
Main outcome measures:
Hospitalisation and death rates due to injury by age, sex, injury mechanism and Indigenous status. Rate ratios for comparison between Indigenous and non-Indigenous populations.
Results:
Rates of death from injury were higher for all age groups in the Indigenous population, except people older than 65 years. Indigenous people aged 25–44 years were twice as likely to be hospitalised as their non-Indigenous counterparts (rate ratio [RR], 2.09; 95% CI, 2.03–2.14), and five times as likely to be hospitalised for interpersonal violence (RR, 5.19; 95% CI, 4.98–5.40).
Conclusion:
The higher rates of injury-related hospitalisation and death in the Indigenous population in NSW are consistent with data reported for other parts of Australia. Of particular concern is the number of Indigenous deaths and hospitalisations due to interpersonal violence.

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Objective:
To quantify the burden of disease and injury for the Aboriginal and non-Aboriginal populations in the Northern Territory.

Design and setting:
Analysis of Northern Territory data for 1 January 1994 to 30 December 1998 from multiple sources.

Main outcome measures:
Disability-adjusted life-years (DALYs), by age, sex, cause and Aboriginality.

Results:
Cardiovascular disease was the leading contributor (14.9%) to the total burden of disease and injury in the NT, followed by mental disorders (14.5%) and malignant neoplasms (11.2%). There was also a substantial contribution from unintentional injury (10.4%) and intentional injury (4.9%). Overall, the NT Aboriginal population had a rate of burden of disease 2.5 times higher than the non-Aboriginal population; in the 35-54-year age group their DALY rate was 4.1 times higher. The leading causes of disease burden were cardiovascular disease for both Aboriginal men (19.1%) and women (15.7%) and mental disorders for both non-Aboriginal men (16.7%) and women (22.3%).

Conclusions:
A comprehensive assessment of fatal and non-fatal conditions is important in describing differentials in health status of the NT population. Our study provides comparative data to identify health priorities and facilitate a more equitable distribution of health funding.


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This paper examines aspects of knowledge management that are particularly important in the network of human service delivery agencies in Victoria. This network is characterised by four features: it is a cluster of networked organisations; professionals and others may act as knowledge brokers within and between organisations in the network; rapid change in both knowledge and organisation accentuates the importance of innovative knowledge and emergent organisation over and above routine instrumental knowledge within stable organisation; and consequently there is an underlying concern with dialogical rather than instrumental knowledge and its management, and particularly how it constitutes and is constituted by organisation. The paper describes the analytical tools that we consider particularly important in examining this situation – in particular, the distinction between instrumental and dialogical knowledge, and the role of knowledge brokers (and professionals as knowledge brokers). It concludes by relating this analysis to broader issues in organisation studies, and suggests paths for further examination of these issues.