The influence of surface forces on thin film drainage between a fluid drop and a flat solid

An experiment is described in which a mica surface is driven towards a mercury drop immersed in aqueous electrolyte. Under appropriate conditions, hydrodynamic pressure in the aqueous film creates a classical dimple in the mercury drop. The use of optical interferometry and video recording to monitor the shape of the drop and the thickness of the aqueous film with sub-nanometre resolution yields a high density of precise data showing the formation and evolution of the dimple as the film drains. Variation of electrical potential applied to the mercury phase allows control of the surface forces acting between the drop and the mica surface, so that the effect of surface forces on the film drainage process is highlighted. It is found that the film thickness at the centre of the dimple and the lateral extent of the dimple are not significantly affected by surface forces. On the other hand, the minimum film thickness at the edge of the dimple is sensitive even to weak surface forces. Since this minimum film thickness is a major determinant of the film drainage rate, it is shown that surface forces have an important effect on the overall drainage process.

The influence of cover on nesting Red-capped Plovers: a trade-off between thermoregulation and predation risk?

 Some ground-nesting birds adopt a mixed strategy of nesting in the open, or under cover (e.g. vegetation). This may represent a trade-off between thermally favourable nest sites (covered) and those that enable the early detection and avoidance of predators (open). This study examined whether such a trade-off exists for Redcapped Plover Charadrius ruficapillus, whose eggs are preyed upon principally by Little Raven Corvus mellori. For real and artificial nests, nest temperatures under cover (real, 25.9 ± 0.1°C; false, 16.2 ± 0.5°C) were cooler than those in the open (real, 26.8 ± 0.1°C; false, 17.4 ± 0.9°C). Covered nests had more visual obstructions than open nests (covered, 65.5% ± 11.4%; open, 7.4% ± 2.8%) and a standardised measure of incubator escape distance, initiated by experimental human approaches, indicated incubators fled open nests at longer distances than for covered nests. Nests under cover showed a slightly (non-significant) higher probability of surviving one day (Daily Survival Rate [DSR] = 0.978) than those in the open (DSR = 0.950). For false nests containing model eggs, covered nests exhibited better survival to 10 days compared with open nests (20.4% vs. 4.7%). Thus, covered nests are associated with enhanced thermal environments and egg survival, but predators can approach the incubator more closely. Overall, the proposed trade-off between thermal and predation risks associated with nest sites appears to exist and explains the ongoing occurrence of nests in open and covered locations.

The influence of stocking rate and mixed grazing of Angora goats and Merino sheep on animal and pasture production in southern Australia. 4. Gastrointestinal parasitism

Gastrointestinal nematodes limit the growth, production and welfare of goats but there are few reliable sources of information for recommending management practices across flocks. The effects of animal species (Angora goat, Merino sheep, mixed-grazed goats and mixed-grazed sheep at the ratio of 1:1) and stocking rate (SR: 7.5, 10, 12.5 animals/ha) on gastrointestinal parasitism were determined in a replicated experiment on improved annual temperate pastures in southern Australia, from 1981 to 1984. Detailed monitoring of gastrointestinal nematodes was undertaken on animals before, during (five times per year) and at the conclusion of studies using faecal strongyle egg counts (WEC) and total worm counts. Sheep had a greater proportion of nematodes as Teladorsagia spp. and goats a greater incidence of Trichostrongylus spp. Both goats and sheep developed resistance to Nematodirus spp. during the experiment. WEC was similar in goats and sheep at the start of the experimental period but, thereafter, was consistently greater in goats than in sheep. While WEC was highly related to total worm count, the regressions for sheep and goats were different. Increasing the SR increased the WEC of goats and mixed-grazed goats but not of sheep. During the experiment, WEC declined at 7 and 10 animals/ha but increased at 12.5/ha. Mixed grazing with goats provided beneficial effects for sheep at all stocking rates, but the effects for goats were dependent on the stocking rate, being beneficial at 7.5 and 10/ha but harmful at 12.5/ha. The WEC of separately grazed goats were generally higher than the WEC of mixed grazed goats. The WEC of mixed sheep were lower than those of separately grazed sheep. During the experiment, the WEC of mixed grazed sheep declined faster than the WEC of separately grazed sheep but the WEC of separately grazed goats at 12.5/ha and of mixed grazed goats at 10 and 12.5/ha increased. Under the environmental and pastoral conditions examined, Angora wether goats should not be grazed at SR above those recommended for wether sheep. In the present study, the impact of gastrointestinal-nematode infections in goats was reduced at lower SR. Further, mixed grazing of Angora wether goats with wether sheep at or below the recommended SR resulted in reduced gastrointestinal parasitism for both sheep and goats, compared with monospecific grazing conditions. Goats did not represent a gastrointestinal-nematode hazard to sheep. © 2014 CSIRO.

Shining the light on sunshine: a systematic review of the influence of sun exposure on type 2 diabetes mellitus-related outcomes

Prospective observational studies uniformly link vitamin D deficiency with the incidence of type 2 diabetes mellitus (T2DM), yet trials supplementing participants at risk of T2DM with vitamin D to reduce progression to T2DM have yielded inconsistent results. Inconsistencies between supplementation trials may be due to insufficient dosing or small sample sizes. Observational studies may also have reported spurious associations due to uncontrolled confounding by lifestyle or genetic factors. Alternatively, observational and intervention studies may not be entirely comparable. Observational studies show an association between higher vitamin D status, which is predominantly derived from sun exposure, and decreased incidence of T2DM. Trials intervene with vitamin D supplementation, and therefore may be missing alternate causes of the effect of sun exposure, as seen in observational studies. We propose that sun exposure may be the driving force behind the associations seen in observational studies; sun exposure may have additional benefits beyond increasing serum 25-hydroxyvitamin D (25OHD) levels. We performed an electronic literature search to identify articles that examined associations between sun exposure and T2DM and/or glucose metabolism. A best evidence synthesis was then conducted using outcomes from analyses deemed to have high methodological quality. Ten eligible full-text articles were identified, yielding 19 T2DM-related outcomes. The best evidence analysis considered 11 outcomes which were grouped into six outcome types: T2DM, fasting glucose, glucose tolerance, fasting insulin, insulin secretion and insulin sensitivity. There was moderate evidence to support a role of recreational sun exposure in reducing odds of T2DM incidence. High-level evidence was lacking; evidence presented for other outcomes was of low or insufficient level. This review highlights significant gaps in research pertaining to sun exposure and T2DM-related outcomes. Further research is encouraged as we aim to identify novel preventative strategies for T2DM.

The influence of non-climate predictors at local and landscape resolutions depends on the autecology of the species

Species distribution models have come under criticism for being too simplistic for making robust future forecasts, partly because they assume that climate is the main determinant of geographical range at large spatial extents and coarse resolutions, with non-climate predictors being important only at finer scales. We suggest that this paradigm might be obscured by species movement patterns. To explore this we used contrasting kangaroo (family Macropodidae) case studies: two species with relatively small, stable home ranges (Macropus giganteus and M.robustus) and three species with more extensive, adaptive ranging behaviour (M.antilopinus, M.fuliginosus and M.rufus). We predicted that non-climate predictors will be most influential to model fit and predictive performance at local spatial resolution for the former species and at landscape resolution for the latter species. We compared residuals autocovariate - boosted regression tree (RAC-BRT) model statistics with and without species-specific non-climate predictors (habitat, soil, fire, water and topography), at local- and landscape-level spatial resolutions (5 and 50km). As predicted, the influence of non-climate predictors on model fit and predictive performance (compared with climate-only models) was greater at 50 compared with 5km resolution for M.rufus and M.fuliginosus and the opposite trend was observed for M.giganteus. The results for M.robustus and M.antilopinus were inconclusive. Also notable was the difference in inter-scale importance of climate predictors in the presence of non-climate predictors. In conclusion, differences in autecology, particularly relating to space use, may contribute to the importance of non-climate predictors at a given scale, not model scale per se. Further exploration of this concept across a range of species is encouraged and findings may contribute to more effective conservation and management of species at ecologically meaningful scales. © 2014 Ecological Society of Australia.

The influence of follower cultural orientation on attitudinal responses towards transformational leadership: evidence from the Chinese hospitality industry

In addition to extending the empirical investigation of the relationship between transformational leadership and follower affective commitment to the Chinese hospitality industry, this study makes a theoretical contribution by investigating the influence of individually held cultural values on this relationship. Building on previous research which has examined whether collectivism moderates the transformational leadership/affective commitment relationship, this study investigates the moderating effects of two additional cultural value orientations, namely power distance and uncertainty avoidance. Hierarchical regression analysis was utilized to analyse survey data from 398 employees of four Chinese hotels in Zhejiang Province. In addition to finding a positive relationship between transformational leadership and affective commitment, data analysis revealed that followers low in power distance exhibited higher levels of affective commitment when working under a transformational leader than those high in power distance. In addition, followers high in uncertainty avoidance and collectivism exhibited greater commitment when working under a transformational leader than those low in uncertainty avoidance and collectivism. These findings clearly indicate the importance of within-country cultural differences to the effectiveness of leaders in the workplace. © 2014 © 2013 Taylor & Francis.

Understanding the effectiveness of cathodic protection under disbonded coatings

© 2015 Elsevier Ltd. All rights reserved. Factors affecting the effectiveness of cathodic protection under disbonded coatings were studied using a partially covered two dimensional electrode array that simulates a crevice under a disbonded coating and allows for the mapping of electrochemical currents under the influence of cathodic protection (CP). This technique enabled the study of the effects of major factors, including crevice gap size, solution conductivity and applied CP potential on the distribution and evolution of CP currents over the electrode array surface. The effect of each of these factors on the overall current distribution profile has been explained using a new electrochemical model. This model suggests that, despite the detrimental effect of cathodic shielding, the steel under disbonded areas could still be protected, independent of the crevice geometry and solution resistivity, by means of concentration polarization instead of direct electrochemical polarization. A set of conditions for maintaining CP potentials more negative than -850 mVCSE along disbonded coating areas was deduced from the proposed model and validated against potential profiles available in the literature. The possible practical implications of the current mapping technique used in this study for developing in-situ CP monitoring sensors has also been discussed.

The influence of remuneration structures on financial reporting quality: evidence from Australia

This cross-sectional study investigates the influence of a company's remuneration structure on managers' opportunistic behaviour. The findings support the proposed hypothesis that a higher level of compliance with Remuneration Principle 8-ASX Corporate Governance Council) is associated with a lower level of earnings management. The findings support the efficient functioning of the ASX proposed remuneration structure. This cross-sectional study investigates the influence of remuneration structures on financial reporting quality, based on a sample of companies listed on the Australian Securities Exchange (ASX). Compliance with Remuneration Principle eight issued by ASX (providing recommendations on formation, operation and disclosure of remuneration committees) is expected to improve financial reporting quality represented by a decreased level of earnings management. This study expands the corporate governance literature by examining an under-researched mechanism to address the agency problem. Earnings management, as a consequence of the agency problem, is measured using the level of absolute discretionary accruals. In this study, we use the modified Jones model to measure the level of discretionary accruals and the existence of reduced earnings management. The study is conducted using a random sample of 214 firm-year observations selected from the ASX listed companies. Our findings show a higher level of compliance with the principle on remuneration is associated with lower levels of earnings management. The findings support the efficient functioning of the ASX-proposed remuneration structure in reducing earnings manipulations.

Space-crossing : community-based data forwarding in mobile social networks under the hybrid communication architecture

In this paper, we study two tightly coupled issues, space-crossing community detection and its influence on data forwarding in mobile social networks (MSNs). We propose a communication framework containing the hybrid underlying network with access point (AP) support for data forwarding and the base stations for managing most of control traffic. The concept of physical proximity community can be extended to be one across the geographical space, because APs can facilitate the communication among long-distance nodes. Space-crossing communities are obtained by merging some pairs of physical proximity communities. Based on the space-crossing community, we define two cases of node local activity and use them as the input of inner product similarity measurement. We design a novel data forwarding algorithm Social Attraction and Infrastructure Support (SAIS), which applies similarity attraction to route to neighbor more similar to destination, and infrastructure support phase to route the message to other APs within common connected components. We evaluate our SAIS algorithm on real-life datasets from MIT Reality Mining and University of Illinois Movement (UIM). Results show that space-crossing community plays a positive role in data forwarding in MSNs. Based on this new type of community, SAIS achieves a better performance than existing popular social community-based data forwarding algorithms in practice, including Simbet, Bubble Rap and Nguyen's Routing algorithms.

"I can sit on the beach and punt through my mobile phone" : the influence of physical and online environments on the gambling risk behaviours of young men.

Gambling is rapidly emerging as an important public health issue, with gambling products causing considerable health and social harms to individuals, families and communities. Whilst researchers have raised concerns about online wagering environments, few studies have sought to explore how factors within different gambling environments (both online and land-based) may be influencing the wagering, and more broadly the gambling risk behaviours of young men. Using semi-structured interviews with 50 Australian men (20-37 years) who gambled on sport, we explored the ways in which online and land-based environments may be risk-promoting settings for gambling. This included the appeal factors associated with gambling in these environments, factors that encouraged individuals to gamble, and factors that encouraged individuals to engage in different, and more harmful types of gambling. Interviews were conducted over the course of a year (April 2015 - April 2016). We identified a number of situational and structural factors that promoted risky gambling environments for young men. In the online environment, gambling products had become exceedingly easy to access through mobile technologies, with young men subscribing to multiple accounts to access industry promotions. The intangibility of money within online environments impacted upon risk perceptions. In land-based environments, the social rituals associated with peer group behaviour and sport influenced risky patterns of gambling. The presence of both gambling and alcohol in pub environments led individuals to gamble more than they normally would, and on products that they would not normally gamble on. Land-based venues also facilitated access to multiple forms of gambling under the one roof. We identified a number of factors in both land and online environments that when combined, created risk-promoting settings for gambling among young men. By exploring these contextual conditions that give rise to gambling harm, we are better able to advocate for effective public health responses in creating environments that prevent harmful gambling.

Age and gender differences in the influence of social support on mental health : a longitudinal fixed-effects analysis using 13 annual waves of the HILDA cohort

OBJECTIVES: Perceived social support is associated with better mental health. There has been limited attention to how these relationships are modified by age and gender. We assessed this topic using 13 years of cohort data. STUDY DESIGN: Prospective cohort study. METHODS: The outcome was the Mental Health Inventory-5 (MHI-5), a reliable and valid screening instrument for mood disorders. The main exposure was a social support scale composed of 10 items. We used longitudinal fixed-effects regression modelling to investigate within-person changes in mental health. Analytic models controlled for within-person sources of bias. We controlled for time-related factors by including them into regression modelling. RESULTS: The provision of higher levels of social support was associated with greater improvements in mental health for people aged under 30 years than for older age groups. The mental health of females appeared to benefit slightly more from higher levels of social support than males. Improvements in the MHI-5 were on a scale that could be considered clinically significant. CONCLUSIONS: The benefits of social support for young people may be connected to age-related transitions in self-identity and peer friendship networks. Results for females may reflect their tendency to place greater emphasis on social networks than males.