Increased fluvial runoff terminated inorganic aragonite precipitation on the Northwest Shelf of Australia during the early Holocene.

Inorganic precipitation of aragonite is a common process within tropical carbonate environments. Across the Northwest Shelf of Australia (NWS) such precipitates were abundant in the late Pleistocene, whereas present-day sedimentation is dominated by calcitic bioclasts. This study presents sedimentological and geochemical analyses of core data retrieved from the upper 13 meters of IODP Site U1461 that provide a high-resolution sedimentary record of the last ~15 thousand years. Sediments that formed from 15 to 10.1 ka BP are aragonitic and characterised by small needles (<5 µm) and ooids. XRF elemental proxy data indicate that these sediments developed under arid conditions in which high marine alkalinity favoured carbonate precipitation. A pronounced change of XRF-proxy values around 10.1 ka BP indicates a transition to a more humid climate and elevated fluvial runoff. This climatic change coincides with a shelf-wide cessation of inorganic aragonite production and a switch to carbonate sedimentation dominated by skeletal calcite. High ocean water alkalinity due to an arid climate and low fluvial runoff therefore seems to be a prerequisite for the formation of shallow water aragonite-rich sediments on the NWS. These conditions are not necessarily synchronous to interglacial periods, but are linked to the regional hydrological cycle.

Patient-targeted Googling and social media: a cross-sectional study of senior medical students.

BACKGROUND: Social media and Internet technologies present several emerging and ill-explored issues for a modern healthcare workforce. One issue is patient-targeted Googling (PTG), which involves a healthcare professional using a social networking site (SNS) or publicly available search engine to find patient information online. The study's aim was to address a deficit in data and knowledge regarding PTG, and to investigate medical student use of SNSs due to a close association with PTG. METHOD: The authors surveyed final year medical students at the Otago Medical School, University of Otago in January 2016. A subset completed focus groups that were analysed using thematic analysis to identify key themes relating to students' attitudes towards PTG, and reasons why they might engage in PTG. RESULTS: Fifty-four students completed the survey (response rate = 65.1%), which showed that PTG was uncommon (n = 9, 16.7%). Attitudes were varied and context dependent. Most participants saw problems with PTG and favoured more explicit guidance on the issue (n = 29, 53.7%). SNS usage was high (n = 51, 94.4%); participants were concerned by the content of their SNS profiles and who they were connecting with online. Participants showing high SNS use were 1.83 times more likely to have conducted PTG than lower use groups. CONCLUSIONS: The diverse attitudes uncovered in this study indicated that teaching or guidelines could be useful to healthcare professionals considering PTG. Though ethically problematic, PTG may be important to patient care and safety. The decision to conduct PTG should be made with consideration of ethical principles and the intended use of the information.

Australian shelf sediments reveal shifts in Miocene Southern Hemisphere westerlies.

Global climate underwent a major reorganization when the Antarctic ice sheet expanded ~14 million years ago (Ma) (1). This event affected global atmospheric circulation, including the strength and position of the westerlies and the Intertropical Convergence Zone (ITCZ), and, therefore, precipitation patterns (2-5). We present new shallow-marine sediment records from the continental shelf of Australia (International Ocean Discovery Program Sites U1459 and U1464) providing the first empirical evidence linking high-latitude cooling around Antarctica to climate change in the (sub)tropics during the Miocene. We show that Western Australia was arid during most of the Middle Miocene. Southwest Australia became wetter during the Late Miocene, creating a climate gradient with the arid interior, whereas northwest Australia remained arid throughout. Precipitation and river runoff in southwest Australia gradually increased from 12 to 8 Ma, which we relate to a northward migration or intensification of the westerlies possibly due to increased sea ice in the Southern Ocean (5). Abrupt aridification indicates that the westerlies shifted back to a position south of Australia after 8 Ma. Our midlatitude Southern Hemisphere data are consistent with the inference that expansion of sea ice around Antarctica resulted in a northward movement of the westerlies. In turn, this may have pushed tropical atmospheric circulation and the ITCZ northward, shifting the main precipitation belt over large parts of Southeast Asia (4).

Low-frequency hearing preceded the evolution of giant body size and filter feeding in baleen whales.

Living baleen whales (mysticetes) produce and hear the lowest-frequency (infrasonic) sounds among mammals. There is currently debate over whether the ancestor of crown cetaceans (Neoceti) was able to detect low frequencies. However, the lack of information on the most archaic fossil mysticetes has prevented us from determining the earliest evolution of their extreme acoustic biology. Here, we report the first anatomical analyses and frequency range estimation of the inner ear in Oligocene (34-23 Ma) fossils of archaic toothed mysticetes from Australia and the USA. The cochlear anatomy of these small fossil mysticetes resembles basilosaurid archaeocetes, but is also similar to that of today's baleen whales, indicating that even the earliest mysticetes detected low-frequency sounds, and lacked ultrasonic hearing and echolocation. This suggests that, in contrast to recent research, the plesiomorphic hearing condition for Neoceti was low frequency, which was retained by toothed mysticetes, and the high-frequency hearing of odontocetes is derived. Therefore, the low-frequency hearing of baleen whales has remained relatively unchanged over the last approximately 34 Myr, being present before the evolution of other signature mysticete traits, including filter feeding, baleen and giant body size.

New Miocene Fossils and the History of Penguins in Australia.

Australia has a fossil record of penguins reaching back to the Eocene, yet today is inhabited by just one breeding species, the little penguin Eudyptula minor. The description of recently collected penguin fossils from the re-dated upper Miocene Port Campbell Limestone of Portland (Victoria), in addition to reanalysis of previously described material, has allowed the Cenozoic history of penguins in Australia to be placed into a global context for the first time. Australian pre-Quaternary fossil penguins represent stem taxa phylogenetically disparate from each other and E. minor, implying multiple dispersals and extinctions. Late Eocene penguins from Australia are closest to contemporaneous taxa in Antarctica, New Zealand and South America. Given current material, the Miocene Australian fossil penguin fauna is apparently unique in harbouring 'giant penguins' after they went extinct elsewhere; and including stem taxa until at least 6 Ma, by which time crown penguins dominated elsewhere in the southern hemisphere. Separation of Australia from Antarctica during the Palaeogene, and its subsequent drift north, appears to have been a major event in Australian penguin biogeography. Increasing isolation through the Cenozoic may have limited penguin dispersal to Australia from outside the Australasian region, until intensification of the eastwards-flowing Antarctic Circumpolar Current in the mid-Miocene established a potential new dispersal vector to Australia.

Web-based screening and brief intervention for hazardous drinking: a double-blind randomized controlled trial.

BACKGROUND: Strong evidence exists for the efficacy of screening and brief intervention for reducing hazardous drinking. However, problems have been highlighted with respect to its implementation in health-care systems, not least of which is a reluctance of some doctors to discuss alcohol proactively with their patients. AIMS: To determine the efficacy of a novel web-based screening and brief intervention (e-SBI) to reduce hazardous drinking. DESIGN: A double-blind randomized controlled trial. SETTING: A university student health service. PARTICIPANTS: A total of 167 students (17-26 years) were recruited in the reception area and completed a 3-minute web-based screen including the Alcohol Use Disorder Identification Test (AUDIT) questionnaire. Of these, 112 tested positive, and 104 (52 females) who consented to follow-up were included in the trial. MEASUREMENTS: Drinking frequency, typical occasion quantity, total volume, heavy episode frequency (females > 80 g ethanol, males > 120 g ethanol), number of personal problems, an academic problems score. INTERVENTION: Participants were randomized to 10-15 minutes of web-based assessment and personalized feedback on their drinking (intervention, n = 51) or to a leaflet-only control group (n = 53). FINDINGS: Mean baseline AUDIT scores for control and intervention groups were 16.6 (SD = 6.0) and 16.6 (SD = 5.7). At 6 weeks, participants receiving e-SBI reported significantly lower total consumption (geometric mean ratio = 0.74; 95% confidence interval: 0.56-0.96), lower heavy episode frequency (0.63; 0.42-0.92) and fewer personal problems (0.70; 0.54-0.91). At 6 months personal problems remained lower (0.76; 0.60-0.97), although consumption did not differ significantly. At 6 months, academic problems were lower in the intervention group relative to controls (0.72; 0.51-1.02). CONCLUSIONS: e-SBI reduced hazardous drinking among university students, to an extent similar to that found for practitioner-delivered brief interventions in the general population. e-SBI offers promise as a strategy to reduce alcohol-related harm in a way that is non-intrusive, appealing to the target group, and capable of being incorporated into primary care. Research is required to replicate the findings, to determine the duration of intervention effects, and to investigate the mechanisms by which the intervention operates.

An internet-based survey method for college student drinking research.

The purpose of this study was to describe and assess the utility of an Internet-based survey method for characterizing the alcohol consumption of college students. After extensive pilot research, a random sample of 1910 students aged 16-29 years was invited to complete a questionnaire, consisting of a series of web-pages linked to a relational database on a secure web-site. A branch structure allowed for tailoring of survey items by age and gender. The students received up to nine contacts, including a pre-notice letter with a token gift and an e-mail invitation (Phase 1), a reminder letter and e-mail message (Phase 2), and then telephone reminders and replacement access codes (Phase 3). Non-computer-users were offered a pen-and-paper alternative, making this a mixed-mode survey. The overall response to the survey was 82% (n = 1564). The median completion time was 16.7 min. Participants' comments showed high levels of satisfaction with the survey. Comparison of web (n = 1501) versus pen-and-paper completions (n = 63) revealed no modality effects. Technical problems addressed during the course of implementation included web-browser-operating system incompatibilities, and periodic network errors, although these resulted in little lost participation. Internet-based surveys are feasible for college student research and with carefully managed recruitment, can yield a high response.

Acceptability of various brief intervention approaches for hazardous drinking among university students.

AIMS: To determine the acceptability to university students of practitioner-delivered screening and brief intervention (SBI) versus a novel approach-web-based SBI (e-SBI). METHODS: A random sample of 1910 university students was invited to indicate their preferences for various brief intervention approaches in an internet survey. RESULTS: e-SBI was the most popular intervention. It was favoured by 81% of all students and 82% of hazardous drinkers. CONCLUSIONS: e-SBI is a promising approach for the reduction of hazardous drinking among young people.

Incentives to increase participation in an Internet survey of alcohol use: a controlled experiment.

AIMS: To examine the use of the Internet in a survey of drinking among students, and the effectiveness of incentives to encourage participation. METHODS: In a survey of drinking in university students, a random sample of 160 students were randomly assigned to one of four token incentive conditions. All received posted invitations, and reminders by e-mail and telephone. RESULTS: Overall response was 85% and did not differ significantly by incentive condition. CONCLUSION: Internet surveys are effective in obtaining alcohol use information from students. Minimal incentives may suffice if coupled with intensive follow-up.