Paleoreconstruction of estuarine sediments reveal human-induced weakening of coastal carbon sinks

Human activities in coastal areas frequently cause loss of benthic macrophytes (e.g. seagrasses) and concomitant increases in microalgal production through eutrophication. Whether such changes translate into shifts in the composition of sediment detritus is largely unknown, yet such changes could impact the role these ecosystems play in sequestrating CO 2. We reconstructed the sedimentary records of cores taken from two sites within Botany Bay, Sydney - the site of European settlement of Australia - to look for human-induced changes in dominant sources of detritus in this estuary. Cores covered a period from the present day back to the middle Holocene (~6000 years) according to 210Pb profiles and radiocarbon ( 14C) dating. Depositional histories at both sites could not be characterized by a linear sedimentation rate; sedimentation rates in the last 30-50 years were considerably higher than during the rest of the Holocene. C : N ratios declined and began to exhibit a microalgal source signature from around the time of European settlement, which could be explained by increased nutrient flows into the Bay caused by anthropogenic activity. Analysis of stable isotopic ratios of 12C/ 13C showed that the relative contribution of seagrass and C 3 terrestrial plants (mangroves, saltmarsh) to detritus declined around the time of rapid industrial expansion (~1950s), coinciding with an increase in the contribution of microalgal sources. We conclude that the relative contribution of microalgae to detritus has increased within Botany Bay, and that this shift is the sign of increased industrialization and concomitant eutrophication. Given the lower carbon burial efficiencies of microalgae (~0.1%) relative to seagrasses and C 3 terrestrial plants (up to 10%), such changes represent a substantial weakening of the carbon sink potential of Botany Bay - this occurrence is likely to be common to human-impacted estuaries, and has consequences for the role these systems play in helping to mitigate climate change. © 2011 Blackwell Publishing Ltd.

Not just for romance: applications of speed dating in social work education

In this article we address how a contemporary adaptation of the 'speed dating' model was used for educational purposes with two cohorts of social work students. We outline the dimensions of 'speed dating' as a contemporary social phenomenon, then address how this model relates specifically to groupwork process, and can be used to facilitate social work student learning. The curriculum for two classroom group activities using the 'speed dating' model are outlined, the first to develop university level study skills, the second for debriefing field placement learning experiences. Finally we examine why the 'speed dating' metaphor was successful in provoking a playful yet constructively creative space for students to engage in groupwork process.

1-14C-Linoleic Acid distrubution in various tissue lipids of guinea pigs following an oral dose

A recent study on the metabolism of 1-¹⁴C-α-linolenic acid in the guinea pig revealed that the fur had the highest specific activity of all tissues examined, 48 h after dosing. The present study investigated the pattern of tissue lipid labeling following an oral dose of 1-¹⁴C-linoleic acid after the animals had been dosed for the same time as above. Guinea pigs were fed one of two diets with a constant linoleic acid content (18% total fatty acids) and a different content of α-linolenic acid (0.3 or 17.3%) from weaning for 3 wk and 1-¹⁴C-linoleic acid was given orally to each animal for 48 h prior to sacrifice. The most highly labeled tissues (dpm/mg of linoleic acid) were liver, followed by brain, lung and spleen, heart, kidney and adrenal and intestines, in both diet groups. The liver had almost a three-fold higher specific activity than skin and fur which was more extensively labeled than the adipose and carcass. Approximately two-thirds of the label in skin plus fur was found in the fur which, because of a low lipid mass, would indicate that the fur was highly labeled. All tissues derived from animals on the diet with the low α-linolenic acid level were significantly more labeled than the tissues from the animals on the high α-linolenic acid diet, by a factor of 1.5 to 3. The phospholipid fraction was the most highly labeled fraction in the liver, free fatty acids were the most labeled fraction in skin & fur, while triacyglycerols were the most labeled in the carcass and adipose tissue. In these tissues, more than 90% of the radioactivity was found in fatty acids with 2-double bonds in the tissue lipids. These data indicate that the majority of label found in guinea pig tissues 48 h after dosing was still associated with a fatty acid fraction with 2-double bonds, which suggests there was little metabolism of linoleic acid to more highly unsaturated fatty acids in this time frame. In this study, the labeling of guinea pig tissues with linoleic acid, 48 h after dosing, was quite different from the labeling with α-linolenic acid reported previously. The retention of the administered radioactivity from ¹⁴C-linoleic acid in the whole body lipids was 1.6 times higher in the group fed the low α-linolenic acid diet (diet contained a total of 1.8 g PUFA/100 g diet)compared with the group fed the high α-linolenic acid diet (diet contained 3.6 g PUFA/100 g diet). The lack of retention of ¹⁴C-labeled lipids in the whole body would be consistent with an increased rate of β-oxidation of the labeled fatty acid on the diet rich in PUFA, a result supported by other studies using direct measurement of labeled carbon dioxide.

A new view of the Pella churches in terms of dating and analysis : the typological context

As published in the final reports by the College of Wooster and Sydney University, the dating and analysis of the excavated remains of the three churches and their associated finds at Pella, Jordan, display some puzzling aspects. This paper argues that, in these reports, two of the churches appear to have been dated up to a century later than they should have been, while the suggested date for the third now appears too early. This article examines the problem in the context of a new architectural and theological typology of churches in the East Mediterranean from the 4th to 6th centuries AD.

Child maltreatment in stepfamilies : the impact of mother's dating behaviour

This thesis explored the relative utility of evolutionary and ecological theories to understand under which conditions children in non-biological families are most at risk of childmaltreatment.  The study revealed that single-mothers have complex needs and stressors, which may increase their vulnerability and impact on decisions made in selection of partners.

Orally administered [14C]DPA and [14C]DHA are metabolised differently to [14C]EPA in rats

Previous studies have revealed that C20 PUFA are significantly less oxidised to CO2 in whole-body studies compared with SFA, MUFA and C18 PUFA. The present study determined the extent to which three long-chain PUFA, namely 20 : 5n-3 EPA, 22 : 5n-3 docosapentaenoic acid (DPA) and 22 : 6n-3 DHA, were catabolised to CO2 or, conversely, incorporated into tissue lipids. Rats were administered a single oral dose of 2·5 μCi [1-14C]DPA, [1-14C]EPA, [1-14C]DHA or [1-14C]oleic acid (18 : 1n-9; OA), and were placed in a metabolism chamber for 6 h where exhaled 14CO2 was trapped and counted for radioactivity. Rats were euthanised after 24 h and tissues were removed for analysis of radioactivity in tissue lipids. The results showed that DPA and DHA were catabolised to CO2 significantly less compared with EPA and OA (P< 0·05). The phospholipid (PL) fraction was the most labelled for all three n-3 PUFA compared with OA in all tissues, and there was no difference between C20 and C22 n-3 PUFA in the proportion of label in the PL fraction. The DHA and DPA groups showed significantly more label than the EPA group in both skeletal muscle and heart. In the brain and heart tissue, there was significantly less label in the cholesterol fraction from the C22 n-3 PUFA group compared with the C20 n-3 PUFA group. The higher incorporation of DHA and DPA into the heart and skeletal muscle, compared with EPA, suggests that these C22 n-3 PUFA might play an important role in these tissues.

On-line dating; is a digital kiss and virtual wink the new way of finding love?

In 2007, I asked for a show of hands of people who ‘might consider online dating as a way of finding a partner’. Not a single hand went up and the lecture theatre was stony silent. The same question, some five years later resulted in a significant show of hands and a buzz of chatter. Something had changed and perceptions around online dating had shifted. Nielsen Research last year found most Australians (51 per cent) had either tried online dating or would consider doing so. RSVP and eHarmony claim to have 2 million members and more than 4 million people have apparently joined RSVP since it was launched 17 years ago. Online dating is experiencing significant growth in Asia as well, with the number of new web services (some, like ‘Muslima’, are tightly focused) growing exponentially. Online dating is a global phenomenon. This paper will use current media studies research literature and data from conversations with university students in Australia and Indonesia to explore how the changing world of online dating is helping/hindering young people as they shape and develop identity, represent themselves in the virtual world and ultimately, how they find love on line.

Online dating

Communication, Digital Media and Everyday Life uses stories to explain the journey from ‘new media in communication’ to ‘digital media is communication’ and provide students with a thorough introduction to communication and media theory and practice. It recognises that for generations Y and Z, ‘digital media’ is now embedded into most aspects of everyday life and integrated into contemporary communication as much as speaking, reading and writing.