Factors influencing population dynamics in island and mainland populations of the Swamp Antechinus (Antechinus minimus)

Simultaneously analysing demographic processes of small mammals living in different ecological contexts may help to understand mechanisms that influence the growth and decline of these populations. The size and demography of swamp antechinus (Antechinus minimus) populations located in a coastal mainland habitat and on a small offshore island in south-eastern Australia were investigated. Large demographic differences occurred between the two ecosystems, with the island population density often 100 times greater than that on the mainland. The swamp antechinus in the mainland habitat was influenced by extrinsic climatic forces, with juvenile recruitment, individual body mass and overall population size being affected by rainfall, a factor likely to influence food availability for the species. However, the island population did not appear to be affected by drought to the same degree where allochthonous marine nutrient inputs may have offset any drought-induced reduction in primary production. Significantly greater juvenile recruitment in the island habitats combined with restricted emigration and potentially reduced predation and interspecific competition are likely to be responsible for the high population densities on the island. Although island populations appear robust, future conservation efforts should focus on mainland populations given the genetic deficiencies in the island populations.

Second Life and the role of educators as regulators

Regulation, governance and harms stemming from the use of virtual worlds and other Massive Multi Media Online Role Playing Games (MMMORPGs) in higher education, are poorly understood and under-researched issues. Second Life, developed by Linden Labs, provides users with a series of generic ‘terms of service’ and codes of conduct, yet place the bulk of responsibility on individual users or groups to report misbehaviour or develop their own behavioural codes, enforcement procedures and punishments suited to their particular needs. There is no guidebook to assist users in the processes of risk identification and management. As such, the various benefits of MMMORPG technologies could be offset by the risks to users and user-groups from a range of possible harms, including the impact of actual or perceived violence within teaching and learning settings.

While cautioning against the direct translation of real-world regulatory principles into the governance of virtual worlds, this paper suggests theoretical and practical guidance on these issues can be taken from recent criminological developments. Using Lawrence Lessig’s (1999) landmark work on cyber-regulation as a starting point, this paper examines the literature on video-game violence to illustrate the need for educators show awareness of both real and perceived risks in virtual worlds as a core element of an emerging educational pedagogy. We identify how the multiple roles of the virtual-world educator become useful in framing this pedagogy to improve student learning, to dispel myths about the risks of immersive technologies and advocate for their adoption and acceptance in the educational community.

The cost-effectiveness of removing television advertising of high-fat and/or high-sugar food and beverages to Australian children

Objective: To model the health benefits and cost-effectiveness of banning television (TV) advertisements in Australia for energy-dense, nutrient-poor food and beverages during children's peak viewing times.

Methods: Benefits were modelled as changes in body mass index (BMI) and disability-adjusted life years (DALYs) saved. Intervention costs (AUD$) were compared with future health-care cost offsets from reduced prevalence of obesity-related health conditions. Changes in BMI were assumed to be maintained through to adulthood. The comparator was current practice, the reference year was 2001, and the discount rate for costs and benefits was 3%. The impact of the withdrawal of non-core food and beverage advertisements on children's actual food consumption was drawn from the best available evidence (a randomized controlled trial of advertisement exposure and food consumption). Supporting evidence was found in ecological relationships between TV advertising and childhood obesity, and from the effects of marketing bans on other products. A Working Group of stakeholders provided input into decisions surrounding the modelling assumptions and second-stage filters of 'strength of evidence', 'equity', 'acceptability to stakeholders', 'feasibility of implementation', 'sustainability' and 'side-effects'.

Results: The intervention had a gross incremental cost-effectiveness ratio of AUD$ 3.70 (95% uncertainty interval (UI) $2.40, $7.70) per DALY. Total DALYs saved were 37 000 (95% UI 16 000, 59 000). When the present value of potential savings in future health-care costs was considered (AUD$ 300m (95% UI $130m, $480m), the intervention was 'dominant', because it resulted in both a health gain and a cost offset compared with current practice.

Conclusions: Although recognizing the limitations of the available evidence, restricting TV food advertising to children would be one of the most cost-effective population-based interventions available to governments today. Despite its economic credentials from a public health perspective, the initiative is strongly opposed by food and advertising industries and is under review by the current Australian government.

Economic evaluation of skin cancer prevention in Australia

Objectives
Australia has the highest incidence of skin cancer in the world, despite prevention campaigns being implemented since the early 1980s. This study assesses the cost-effectiveness of a skin cancer prevention program (named SunSmart) since it was introduced, together with its potential cost-effectiveness as an upgraded and ongoing national program.

Methods
The reduction in melanoma incidence attributable to SunSmart was modelled as the primary end-point. Historical expenditures on SunSmart were obtained from representative Australian states in three latitude zones. Melanoma incidence rates from these states were used to model key health outcomes. Non-melanoma skin cancer was modelled separately based on national survey results.

Results
We estimate that SunSmart has averted 28,000 disability-adjusted life-years (DALYs), equivalent to 22,000 life-years saved, in the state of Victoria since its introduction in 1988, as well as saving money from cost offset in skin cancer management (dominant). An upgraded national program for the next 20 years is estimated to avert 120,000 DALYs, with associated reductions in the use of health care resources. It remains a dominant intervention in which every dollar invested in SunSmart will return an estimated AU$2.30.

Conclusions
This study demonstrates that a sustained modest investment in skin cancer control is likely to be an excellent value for money.

Economic evaluation of a skin cancer prevention program in Australia : past achievements and future prospects

Objectives
Australia has the highest incidence of skin cancer in the world. Skin cancer prevention campaigns have been implemented in Australia for over two decades. The most notable is under the brand name, SunSmart. The aim of the current study is to assess the cost-effectiveness of SunSmart in the past and the potential cost-effectiveness of an ongoing national SunSmart program with optimal investment in the future.

Methods
An economic evaluation from a health sector perspective was conducted using the reduction in skin cancer incidence attributable to the SunSmart program modelled as the primary end-point. Historical SunSmart program expenditures were obtained from three representative states in three latitude zones, covering different levels of UVR exposure. Melanoma incidence rates from the three representative state cancer registers were used to model the health outcomes. Program effectiveness was assessed by the comparison between the well-resourced SunSmart state (Victoria) and the under-invested states (New South Wales and Queensland). Non-Melanoma Skin Cancer (NMSC) was modelled based on national survey results. 2003 was chosen as the reference year and future costs/outcomes over a 20 year time horizon were discounted at 3%.
The future level of investment in a national SunSmart was chosen to strengthen current practice by increasing current investment to a realistic and achievable level. This conservative increase in investment (expressed as ‘$ per capita’) reflected the investment level that has been achieved in Victoria over sustained periods. To model the potential cost-effectiveness of an upgraded national SunSmart program, a conservative approach was taken, whereby the same magnitude of effectiveness from 1988 to 2003 was applied to future skin cancer incidence.

Results
SunSmart in Victoria has saved 22,300 life-years, averted 27,900 disability-adjusted life-years(DALYs)(discounted) since its introduction in 1988 and achieved an incremental cost-effectiveness ratio (ICER) of $AUD 680 per life-year saved (LYS) and $AUD 540 per DALY averted. When the cost-offset from the estimated reduction in skin cancer treatment costs were taken into account, SunSmart achieved ‘dominance’. The net cost of SunSmart in the past was an estimated saving of $AUD 93 million. An upgraded national SunSmart for the next 20 years would save 91,000 life-years and avert 122,000 DALYs (discounted), involving an increased investment level from the current $AUD 0.07 per capita to the historical average of $AUD 0.28 per capita. The ICER for the upgraded SunSmart program was estimated at $AUD 940 per LYS and $AUD 700 per DALY averted. When the cost-offset is included, the program achieves dominance with a cost saving of $AUD 115 million – an estimated $AUD 2.32 return for every dollar invested between 2003 and 2022.

Conclusions
This study demonstrates that a sustained modest investment in skin cancer control is likely to be excellent value-for-money. While the available data base is certainly not prefect, key parameters would have to change dramatically for this conclusion to be challenged.

Modeling of advanced high strength steels with the realistic microstructure–strength relationships

The objective of the work is to consider the first-order effects of the realistic microstructure morphology in the macroscale modeling of the multiphase Advanced High Strength Steels (AHSS). Instead of using constitutive equations at macroscale, the strength–microstructure relationship is studied in the forms of micromechanical and multiscale models that do not make considerable simplifications with regard to the microscale geometry and topology. The trade-off between the higher computational time and the higher accuracy has been offset with a stochastic approach in the construction of the microscale models. The multiphase composite effects of AHSS microstructure is considered in realistic microstructural models that are stochastically built from AHSS micrographs. Computational homogenization routines are used to couple micro and macroscale and resultant stress–strain relations are compared for models built with the simplified and idealized geometries of the microstructure. The results from this study show that using a realistic representation of the microstructure, either for DP or TRIP steel, could improve the accuracy of the predicted stress and strain distribution. The resultant globally averaged effective stress and strain fields from realistic microstructure model were able to accurately capture the onset of the plastic instability in the DP steel. It is shown that the macroscale mechanical behavior is directly affected by the level of complexities in the microscale models. Therefore, greater accuracy could be achieved if these stochastic realistic microstructures are used at the microscale models.

Role of angiotensin II in the hypertension induced by renal artery stenosis

Identical degrees of renal artery stenosis were induced in 5 dogs on two separate occasions; once during continuous inhibition of angiotensin I converting enzyme with enalapril, and once with the dogs untreated. Arterial pressure rose about 25 mm Hg during 3 days of stenosis in untreated dogs, due to increased total peripheral resistance. When the dogs were treated with enalapril, blood pressure had risen 14.5 ± 3.4 mm Hg 24 hours after stenosis due to a 35% increase in cardiac output while total peripheral resistance fell by 16%. By the third day, blood pressure had returned to pre-stenosis levels, cardiac output was close to normal and total peripheral resistance had increased. The stenosis on the renal artery increased the resistance to blood flow of the kidneys in both untreated and enalapril treated dogs. This increase in kidney resistance in the untreated dogs accounted for about 30% of the change in total peripheral resistance. In the enalapril treated dogs, the increased kidney resistance helped offset the vasodilatation in the rest of the vasculature. These results suggest that angiotensin II mediated vasoconstriction of nonrenal vascular beds was responsible for about ⅔ of the hypertension following renal artery stenosis, and the resistance of the stenosis responsible for about ⅓.

Why do Gull-billed Terns Gelochelidon nilotica feed on fiddler crabs Uca tangeri in Guinea-Bissau?

Gull-billed Terns Gelochelidon nilotica wintering in Guinea Bissau mainly fed on fiddler crabs Uca tangeri and were occasionally seen feeding on fish and locusts. As fiddler crabs have a low energy content, terns need a large gross intake to meet daily energy demands. Fiddler crabs also have a low ratio of digestible flesh to exoskeleton, and therefore tern food intake may be limited by gut capacity. Activity budgets of Gullbilled Terns feeding on fiddler crabs showed that a considerable part of the time was spent resting. The duration of resting intervals increased with energy intake and was positively correlated with the metabolisable energy content of the crab eaten, suggesting that resting periods were required for a proper digestion. The poor quality of fiddler crabs was offset by high capture rates. So daily energy expenditure of the terns could easily be met by feeding on fiddler crabs. Even when resting pauses were included in foraging time, foraging for only 1.5 hours on fiddler crabs satisfied the terns’ daily energy demands. Instead, feeding on energy-rich fish would require about 2.5 hours to satisfy daily energy demands. Compared to the more specialised piscivorous Little Tern Sternula albifrons and Sandwich Tern Sterna sandvicensis, capture rate of fish was poor in Gull-billed Terns. From an energetic point of view, wintering Gull-billed Terns feeding on fiddler crabs seem to have an easy living in Guinea Bissau.

Bipolar II disorder : a review

Objectives: To review the current knowledge of bipolar II disorder.

Methods: Literature was reviewed after conducting a Medline search and a hand search of relevant literature.

Results: Bipolar II disorder is a common disorder, with a prevalence of approximately 3–5%. Distinct clinical features of bipolar II disorder have been described. The key to diagnosis is the recognition of past hypomania, while depression is the typical presenting feature of the illness. This is responsible for a significant rate of missed diagnosis, and consequent management according to unipolar guidelines. It is unclear if bipolar II disorder is over-represented amongst resistant depression populations and if abrupt offset of antidepressant action is a phenomenon over represented in bipolar II disorder, reflecting induction of predominantly depressive cycling. A few mood-stabilizer studies available provide provisional suggestion of utility. A supportive role for psychosocial therapies is suggested, however, there is a sparsity of published studies specific to bipolar II disorder cohorts. A small number of short-term antidepressant trials have suggested efficacy, however, compelling long-term maintenance data is absent.

Conclusions: An emerging literature on the specific clinical signature and management of the disorder exists, however, this is disproportionately small relative to the epidemiology and clinical significance of the disorder.

Climate change regulation : implications for business executives

Purpose – The purpose of this paper is to provide an overarching conceptual decision model that delineates the major issues and decisions associated with carbon regulations that will allow executives to better understand the potential regulatory schemes and implications that may be imposed in the near future.
Design/methodology/approach – The authors use the extant literature as the foundation to develop a conceptual model of the decisions pertaining to climate change regulation that face business executives today.
Findings – This paper suggests four major categories of issues that must be addressed in any climate change regulatory scheme. These include: “scope” – will carbon emission management systems be global or regional; “who pays” – will the consumer or will the supply chain be responsible for the cost of their emissions; “market or compliance-based mechanisms” – will the CO2 emissions system be market-based or a compliance-based regulatory system; and “criteria” – how can credence of the remedy be established – what is necessary for a business initiative to qualify for as a creditable carbon offset?
Research limitations/implications – This paper offers a framework that categories the fundamental decisions that must be made in any climate change regulation. This framework may be useful in advancing research into any of the four categories of decisions and their implications on commerce and the environment. This paper is designed to be managerially useful and in that way does limit its ability to specifically advance many dimensions of research.
Practical implications – The paper offers executives for a simple model of the decisions that must be made to craft an effective climate change regulatory scheme. In addition, it suggests how these decisions may create exploitable economic opportunities for innovative and proactive firms.
Originality/value – This paper adds value to the debate by clarifying the decisions that must be addressed in any climate change regulation scheme.

Natural convection inside dome shaped enclosures

In the present paper the analysis of heat transfer and free convective motion have been carried out numerically for dome shaped enclosures. The solution method is based on the finite element technique with the frontal solver and is used to examine the flow parameters and the heat transfer characteristics inside dome shaped enclosures of various offsets. In formulating the solution a general conic equation is considered to represent the dome of circular, elliptical, parabolic and hyperbolic shapes. The numerical results indicate that the circular and elliptical shapes of dome give higher heat transfer rate and offset of the dome effects convective heat transfer quite significantly. However, beyond 0.3 top dome offset, the change in overall heat transfer rate is not significant. In addition, the convective phenomenon influenced by a dome shaped cover results in establishing a secondary core region even at a moderate Rayleigh number when compared with an equivalent rectangular enclosure. A good comparison between the present numerical predictions and the previous published data is achieved.

Natural convection in domed porous enclosures : non-darcian flow

The natural-convection flow and associated heat transfer in a fluid-saturated porous medium have been investigated using the generalized porous medium approach for a dome-shaped enclosure. Many new features have been predicted with the connective heat transfer and the shape of the top dome cover. The solutions are obtained for a wide range of Darcy and Rayleigh numbers for different offsets and eccentricities of the top dome covers. The detailed parametric study reveals that there is a significant change in heat transfer rate when the offset is between 0.2 and 0.4. Different shapes of conic section, such as circular, elliptical, parabolic, and hyperbolic are used for the top dome cover, and their effects on natural convection and heat transfer rates are studied.

Natural convection in heat generating oval porous enclosurse : a non-darcian model

This paper presents a series of numerical simulations dealing with the problem of natural convection flows and associated heat transfer in an enclosure filled with a fluid-saturated porous medium. The analysis is based on the finite element technique and incorporates the Brinkman-extended Darcy model for an oval enclosure. The numerical results obtained for a modified Rayleigh number, Ra, Darcy number, Da, offset, E, and eccentricity, e, are presented and discussed. The numerical predictions for a square enclosure compared well with published data. It is found that any increase in Da or Ra results in a higher fluid velocity that is responsible for shifting the core of the flow. Moreover, at higher ovality (E = 0.5), asymmetric flow is observed even at the lower range of Rayleigh number (Ra ⩽ 20), which may be attributed to the effect of curved isothermal wall.

Numerical investigation of natural convection inside complex enclosures

In this article, the analyses of heat transfer and free convective motion have been carried out numerically for various structures. The solution is based on a finite element method with the frontal solver to examine the flow parameters and heat transfer characteristics. Several dome configurations--such as flat, inclined, and dome shapes--are considered for the top of the enclosure. A general conic equation is considered to represent the dome as circular, elliptical, parabolic, or hyperbolic shape. The findings from this study indicate that the convective phenomenon is greatly influenced by the shape of the top cover dome and tends to form a secondary core even at a moderate Rayleigh number when compared with an equivalent rectangular enclosure. In addition, the circular and elliptical shapes of the dome give higher heat transfer rate. The effect of various "offset" of the dome and inclined roof on convective heat transfer is also found to be quite significant. However, beyond 0.3 of offset of the top cover for the dome and inclined roof, the change in overall heat transfer rate is minimal. The heat transfer coefficients of dome shaped and inclined roof enclosures are given and discussed.

How potent is fiscal policy in Australia?

This article examines the efficacy of fiscal policy in Australia, focusing on the relationship between changes in the economy’s consolidated fiscal imbalance and private sector saving over recent decades. We first examine the macroeconomic significance of the offset coefficient between public and private savings, whose size effectively determines the effectiveness of fiscal activism. The approach innovatively suggests that these estimates simultaneously reflect Ricardian and other non-Keynesian explanations of private consumption, such as the lifecycle and permanent income theories. Econometric estimation of the offset coefficient for Australia over the period 1980–2008 yields values between 0.75 and near unity, which imply a small or near-zero fiscal multiplier, and that running budget surpluses to lift national saving is ineffective.