Distortional buckling of I-beams by finite element method

Distortional buckling, unlike the usual lateral-torsional buckling in which the cross-section remains rigid in its own plane, involves distortion of web in the cross-section. This type of buckling typically occurs in beams with slender web and stocky flanges. Most of the published studies assume the web to deform with a cubic shape function. As this assumption may limit the accuracy of the results, a fifth order polynomial is chosen here for the web displacements. The general line-type finite element model used here has two nodes and a maximum of twelve degrees of freedom per node. The model not only can predict the correct coupled mode but also is capable of handling the local buckling of the web.

Phase diagram of the one-dimensional Holstein model of spinless fermions

The one-dimensional Holstein model of spinless fermions interacting with dispersionless phonons is studied using a new variant of the density matrix renormalization group. By examining various low-energy excitations of finite chains, the metal-insulator phase boundary is determined precisely and agrees with the predictions of strong coupling theory in the antiadiabatic regime and is consistent with renormalization group arguments in the adiabatic regime. The Luttinger liquid parameters, determined by finite-size scaling, are consistent with a Kosterlitz-Thouless transition.

The individual within the group: Balancing the need to belong with the need to be different

Many theorists have wrestled with the notion of how people balance their need to be included in social groups with their need to be different and distinctive. This question is particularly salient to researchers from the social identify perspective, who have traditionally viewed individual differentiation within groups as being inimical to group identification. In this article we present a number of strategies that people can use to balance their need to belong and their need to be different, without violating social identity principles. First, drawing from optimal distinctiveness theory, we discuss 4 ways in which the need for belonging and the need to be different can be resolved by maximizing group distinctiveness. We then discuss 4 ways in which it is possible to achieve individual differentiation within a group at the same time demonstrating group identification. These strategies are discussed and integrated with reference to recent empirical research and to the social identity perspective.

Evaluation of the effectiveness of enrichment for a group of captive squirrel monkeys (Saimiri sciureus) using time-lapse recording and instantaneous scan sampling

One aim of providing enrichment to captive animals is to promote the expression of behavioural patterns similar to their wild conspecifics. We evaluated the effectiveness of four types of simple feeding enrichment, using surveillance cameras to record the behaviour of 11 captive squirrel monkeys housed in a single enclosure at Alma Park Zoo in Brisbane, Australia. The enrichment involved differences in presentation (whole/chopped) and distribution (localised/scattered) of fruit and vegetables that were part of the normal diet of these animals. Distinguishing between individual squirrel monkeys was not possible from the videos, so Instantaneous Scan Sampling was used to record the numbers of animals performing particular behaviours every 15 minutes over the 24 hour period as well as every 5 minutes for the hour following provision of enrichment. This provided an estimation of the percentage of time spent by the group in various activities. As a result of the enrichment, the activity budget of the group more closely approximated that of wild squirrel monkeys. However on a number of occasions where the enrichment required the squirrel monkeys to work to obtain their food (whole fruit and vegetables), a number of individuals became aggressive towards the zookeepers. This result highlights the variation in responses of individual animals towards enrichment and indicates that in enclosures with large numbers of animals, the response of each individual should be evaluated in addition to the overall benefit of the enrichment for the group. Furthermore, this variation also suggests that it may be beneficial to provide the animals with choices of enrichment as opposed to providing single forms of enrichment that may only be effective for a proportion of the animals in the enclosure, and may even result in undesirable responses from some individuals.

Changes in social identity when joining a new group: The role of individual-level and group-level adaptation processes

While classic intergroup theories have specified the processes explaining situational shifts in social identification, the processes whereby social identities change more profoundly and become integrated within the self have to be proposed. To this aim, the present studies investigate the processes by which group members integrate a new social identity as they are joining a new group. Combining a social identity approach and stress and coping models, this research tests if social factors (i.e., needs satisfied by fellow group members, social support), have an impact on the adaptation strategies group members use to deal with the novelty of the situation and to fit into their new group (seeking information & adopting group norms vs. disengaging). These strategies, in turn, should predict changes in level of identification with the new social group over time, as well as enhanced psychological adjustment. These associations are tested among university students over the course of their first academic year (Study 1), and among online gamers joining a newly established online community (Study 2). Path analyses provide support for the hypothesised associations. The results are discussed in light of recent theoretical developments pertaining to intraindividual changes in social identities and their integration in the self.

Hysterectomy fractions in New South Wales, 1971-2006

Hysterectomy fractions by age group for particular periods are of interest for: estimating proper population denominators for calculation of disease and procedure rates affecting the cervix and uterus; estimating the target population for Pap test programs, and response rates; and as a way of displaying the cumulative consequences of hysterectomies in a population. Hysterectomy fractions for populations can be determined by direct inquiry via a representative sample survey, or, as in this study, from prior hysterectomy rates of the cohorts of women which compose each age bracket. Hysterectomy data 1979-93 were obtained from the hospital In-patients Statistics Collection (ISC) which covers both public and private hospitals in NSW. Annual population denominators of women were obtained from Census data. Data were modelled by Poisson regression, using five.-year age group (15-greater than or equal to 85 years), annual period, and five-year birth cohort (APC model). Forward- and back-projection of the period effects were undertaken. The resultant NSW hysterectomy fractions by age and period are consistent with fractions obtained from modelled hysterectomy rates for Western Australia (1980-84), and fractions from national representative sample surveys (1989/90 and 1995) for younger women, but not for women aged greater than or equal to 70 years in 1995, which revealed higher hysterectomy fractions than modelled hysterectomy data would suggest. Hysterectomy fractions for NSW women by five-year age group for quinquennia centred on 1971 to 2006 are provided.

Dental set-vice provision in private general practice for an insured population in New South Wales, Australia

Objective To determine patterns of dental set-vices provided to a cohort of the insured population 18 years and over, in private general practice in New South Wales, Australia. Basic research design A cohort study using the person-years method and Poisson regression for analysis. Setting Data were derived from claims records submitted by members of a health insurance fund (Government Employees Health Fund-GEHF) for rebates during the study period 1 January 1992-31 December 1995. Participants There were 133,467 members aged 18 years and over from New South Wales. Main outcome measures To determine, by age group, for those members who used private general practice and made a claim (referred to as 'patients') the annual number of visits, total number of services received per year and number of services received at a visit, Results The mean number of visits per patient was 2.4 per year with patients under 45 years making fewer visits than the 45-54 age group reference category. Mean number of services utilised per patient-year was 5.9, with services provided increasing from 3.5 for the 18-24-year-old group, reaching a plateau of approximately 6.2 for those aged 45 years or more. The number of services received per visit was 2.4 and there were no differences by age. Service mix was dominated by restorative (35%), diagnostic (27%), and preventive services (18%); with age specific variations observed. Conclusions Age was found to be an important determinant in the use of dental services, independent of membership duration and gender.

'You can criticise because you care': How attributions affect responses to ingroup and outgroup critics

There are times when people feel compelled to stand up and articulate their group's shortcomings, an act that carries with it enormous social risks. Indeed, a mechanistic reading of social identity theory might lead one to believe that ingroup critics are doomed to face hostility because they are attacking a fundamental part of people's self-concept. But often ingroup critics are doing more than attacking their group — they are trying to incite positive change. Criticism is the cornerstone of protest, and it is difficult to imagine how a group can be reinvigorated, reinvented, or reformed without some process of critical self-reflection. Thus, although the ingroup critic might create tension within the group, it is possible that internal criticism could be seen by other group members as beneficial in terms of promoting positive change and stimulating innovation, creativity, and flexibility in decision making. In this talk I examine the 'identity rules' that ingroup critics need to follow to avoid defensiveness, and look at empirical evidence of how factors such as language, the intergroup context, and choice of audience shape people's attributions regarding criticism and their subsequent evaluations of critics.

Mental health and socio-economic variations in Australian suicide

This paper investigates the relationship between suicide rates and prevalence of mental disorder and suicide attempts, across socio-economic status (SES) groups based on area of residence. Australian suicide data (1996-1998) were analysed in conjunction with area-based prevalences of mental disorder derived from the National Survey of Mental Health and Well-Being (1997). Poisson regression models of suicide risk included age, quintile of area-based SES, urban-rural residence, and country of birth (COB), with males and females analysed separately. Analysis focussed on the association between suicide and prevalences of (ICD-10) affective disorders, anxiety disorders, substance use disorders and suicide attempts by SES group. Prevalences of other psychiatric symptomatology, substance use problems, health service utilisation, stressful life-events and personality were also investigated. Significant increasing gradients were evident from high to low SES groups for prevalences of affective disorders, anxiety disorders (females only), and substance use disorders (males only); sub-threshold drug and alcohol problems and depression; and suicide attempts and suicide (males only). Prevalences of mental disorder, other sub-threshold mental health items and suicide attempts were significantly associated with suicide, but in most cases associations were reduced in magnitude and became statistically non-significant after adjustment for COB, urban-rural residence, and SES. For male suicide the relative risk (RR) in the lowest SES group compared to the highest was 1.40 (95% CI 1.29-1.52, p < 0.001) for all ages, and 1.46 (95% CI 1.27-1.67, p < 0.001) for male youth (20-34 years). This relationship was not substantially modified in males when regression models included prevalences of affective disorders, and other selected mental health variables and demographic factors. From a population perspective, SES remained significantly associated with suicide after controlling for the prevalence of mental disorders and other psychiatric symptomatology. Mental conditions and previous suicidal behaviour may play an intermediary role between SES and suicide, but this study suggests that an independent relationship between suicide and SES also exists. (c) 2005 Elsevier Ltd. All rights reserved.

Ecology, values, and objectivity: Advancing the debate

We add to current discussions about the interface between ecology, values, and objectivity by reporting on a novel Delphi-based study of the scientific reasoning employed by a group of eight ecologists as they collectively considered current ecological thinking. We rely on contextual empiricism, with its features of multiple ways of relating theory to reality and science as a social activity, to provide a richer understanding of scientific objectivity. This understanding recognizes the place and contributions of values and, in so doing, moves the discussion beyond whether or not science is value neutral.

Factors influencing organisational silence

Organisadonal silence is a recendy introduced area of business research that seeks to address why employees fail to express ideas, informadon and opinions that can effecdvely improve organisadonal effecdveness. In making a start to understand silence, the majority of frameworks have suggested that employees withhold valuable input from management because they believe that it is too personally cosdy to speak up, and/or management are unMkely to take acdon about their ideas or concerns. Because today's workforce are largely required to work in groups or teams, one of the primary aims of this paper is to provide a deeper understanding of this phenomenon by focusing on group process factors that are likely to drive silence. Research that consider the group perspecdve indicate that one's ingroup posidon (i,e,, pro to typicality), and the accumuladon of idiosyncrasy credits (i,e,, leeway to offer innovadve ideas) are likely to play a role in whether (or not) people speak up. For example, those on the periphery of the group or less prototypical group members may need to conform strenuously to group norms in order to improve their ingroup posidon. Similarly, those who have accrued few idiosyncrasy credits may need to conform to group expectadons in order to accumulate sufficient "resources" to deviate from group norms, and be taken seriously by other group members. Thus, the conceptual framework proposed is underpinned by the social idendty perspecdve as well as the nodon of idiosyncrasy credits.

Non-cancer mortality among people diagnosed with cancer (Australia)

Objective To investigate whether people diagnosed with cancer have an increased risk of death from non-cancer causes compared to the general population. Methods The non-cancer mortality of people diagnosed with cancer in Queensland (Australia) between 1982 and 2002 who had not died before 1 January 1993 was compared to the mortality of the total Queensland population, matching by age group and sex, and reporting by standardised mortality ratios. Results Compared to the non-cancer mortality in the general population, cancer patients (all cancers combined) were nearly 50% more likely to die of non-cancer causes (SMR = 149.9, 95% CI = [147-153]). This varied by cancer site. Overall melanoma patients had significantly lower non-cancer mortality, female breast cancer patients had similar non-cancer mortality to the general population, while increased non-cancer mortality risks were observed for people diagnosed with cervical cancer, colorectal cancer, prostate cancer, non-Hodgkin lymphoma and lung cancer. Conclusions Although cancer-specific death rates underestimate the mortality directly associated with a diagnosis of cancer, quantifying the degree of underestimation is difficult due to various competing explanations. There remains an important role for future research in understanding the causes of morbidity among cancer survivors, particularly those looking at both co-morbid illnesses and reductions in quality of life.

Response programming in dementia of the Alzheimer type: A kinematic analysis

Although planning is important for the functioning of patients with dementia of the Alzheimer Type (DAT), little is known about response programming in DAT. This study used a cueing paradigm coupled with quantitative kinematic analysis to document the preparation and execution of movements made by a group of 12 DAT patients and their age and sex matched controls. Participants connected a series of targets placed upon a WACOM SD420 graphics tablet, in response to the pattern of illumination of a set of light emitting diodes (LEDs). In one condition, participants could programme the upcoming movement, whilst in another they were forced to reprogramme this movement on-line (i.e. they were not provided with advance information about the location of the upcoming target). DAT patients were found to have programming deficits, taking longer to initiate movements; particularly in the absence of cues. While problems spontaneously programming a movement might cause a greater reliance upon on-line guidance, when both groups were required to guide the movement on-line, DAT patients continued to show slower and less efficient movements implying declining sensori-motor function; these differences were not simply due to strategy or medication status. (C) 1997 Elsevier Science Ltd.

Pulsed quadrature-phase squeezing of solitary waves in chi((2)) parametric waveguides

It is shown that coherent quantum simultons (simultaneous solitary waves at two different frequencies) can undergo quadrature-phase squeezing as they propagate through a dispersive chi((2)) waveguide. This requires a treatment of the coupled quantized fields including a quantized depleted pump field. A technique involving nonlinear stochastic parabolic partial differential equations using a nondiagonal coherent state representation in combination with an exact Wigner representation on a reduced phase space is outlined. We explicitly demonstrate that group-velocity matched chi((2)) waveguides which exhibit collinear propagation can produce quadrature-phase squeezed simultons. Quasi-phase-matched KTP waveguides, even with their large group-velocity mismatch between fundamental and second harmonic at 425 nm, can produce 3 dB squeezed bright pulses at 850 nm in the large phase-mismatch regime. This can be improved to more than 6 dB by using group-velocity matched waveguides.

Pediculus humanus capitis infestations in the community: A pilot study into transmission, treatment and factors affecting control

Head lice (Pediculus humanus capitis) infestations affect schoolchildren worldwide, creating social, economic and health consequences for families. Problems with self-detection, chronic infestations and classroom transmission are compounded by increasing resistance of the lice to pediculicides. Public health strategies are based on limited research and little is known about transmission dynamics. Mismanagement and transmission in the general community are blamed for control failure. The purpose of this study was to explore community head-lice experience in Brisbane, Australia, and to identify critical factors underlying control failure. A home-based pilot survey used physical examination to verify transmission and treatment patterns which were self-reported by a group of trace-contact families in addition to other unconnected participants. The survey was enlarged to further compare therapy outcomes and suspected risk factors. The findings reinforce those of previous studies - that children attending school and early childhood centres, and subsequently their families, are most at risk of contracting pediculosis capitis, and some may carry lice for years. First-line (pediculicidal) treatment and even additional physical methods of hand-picking and fine-toothed combing usually fail to eradicate lice quickly and completely (overall cure-rate 39 per cent, n = 84 cases). Failures were linked to hair characteristics. Public education alone may not control pediculosis. Accurate diagnosis requires considerable experience; a strong case exists for returning to institutional surveillance.