Evidence for suppressed mid-Holocene northeastern Australian monsoon variability from coral luminescence

Summer monsoon rainfall in northeastern (NE) Australia exhibits substantial interannual variability resulting in highly variable river flows. The occurrence and magnitude of these seasonal river flows are reliably recorded in modern inshore corals as luminescent lines. Here we present reconstructed annual river flows for two ~120 year mid-Holocene windows based on luminescence measurements from five cores obtained from three separate coral colonies. We were able to cross-date the luminescence signatures in four cores from two of the colonies, providing confidence in the derived reconstruction. Present-day NE Australian rainfall and river flow are sensitive to El Niño–Southern Oscillation (ENSO) variability, with La Niña (El Niño) events typically associated with wetter (drier) monsoon seasons. Thus, our replicated and annually resolved coral records provide valuable insights into the northern Australian summer monsoon and ENSO variability at a key period (6 ka) when greenhouse gas levels and ice sheet cover were comparable to the preindustrial period but orbital forcing was different. Average modern and mid-Holocene growth characteristics were very similar, suggesting that sea surface temperatures off NE Australia at 6 kyr were also close to present values. The reconstructed river flow record suggests, however, that the mid-Holocene Australian summer monsoon was weaker, less variable from year to year (possibly indicative of reduced ENSO variability), and characterized by more within-season flood pulses than present. In contrast to today, the delivery of moisture appears to have been dominated by eastward propagating convective coupled waves associated with the Madden-Julian Oscillation

Aspects of Two-Photon Physics at Linear e+e- Colliders

We discuss various reactions at future e+e- and gamma-gamma colliders involving real (beamstrahlung or backscattered laser) or quasi--real (bremsstrahlung) photons in the initial state and hadrons in the final state. The production of two central jets with large pT is described in some detail; we give distributions for the rapidity and pT of the jets as well as the di--jet invariant mass, and discuss the relative importance of various initial state configurations and the uncertainties in our predictions. We also present results for `mono--jet' production where one jet goes down a beam pipe, for the production of charm, bottom and top quarks, and for single production of W and Z bosons. Where appropriate, the two--photon processes are compared with annihilation reactions leading to similar final states. We also argue that the behaviour of the total inelastic gamma-gamma cross section at high energies will probably have little impact on the severity of background problems caused by soft and semi--hard (`minijet') two--photon reactions. We find very large differences in cross sections for all two--photon processes between existing designs for future e+e- colliders, due to the different beamstrahlung spectra; in particular, both designs with >1 events per bunch crossing exist.Comment: 51 pages, 13 figures(not included

Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $\gamma p$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

Paralytic shellfish toxins in the xanthid crab Atergatis floridus collected from Australian coral reefs

One hundred and nine specimens of Atergatis floridus (Xanthidae) were collected from coral reefs of the Capricorn Group in the southern region of the Great Barrier Reef, Queensland, Australia. Sixty-five acidified 70% ethanol extracts of whole crabs contained detectable toxicity, quantified with an assay which defines 1 mouse unit (MU) as the intraperitoneal dose which kills a 20 g mouse in 15 min. The most toxic extract contained 3838 MU (108 MUg of crab), which exceeds the suggested human lethal dose. Chromatography and electrophoresis detected toxins similar to the paralytic shellfish toxins (PSTs), namely saxitoxin, neosaxitoxin and gonyautoxins 1 and 2. All of the purified toxins exhibited pharmacoloģical activity consistent with that exhibited by the PSTs. No more than two of these toxins were present in any extract. Statistical analysis demonstrated there were geographic and temporal patterns in the variation of crude toxicity levels. Combined foregut contents from 42 of the crabs comprised fish, crustacean and algal remains, from which 279 MU were extracted from 1.4 g of material (= 199 MUg

Apparent relationships between toxins elaborated by the cyanobacterium Trichodesmium erythraeum and those present in the flesh of the narrow-barred Spanish mackerel Scomberomorus commersoni

R. Endean, S. A. Monks, J. K. Griffith and L. E. Llewellyn. Apparent relationships between toxins elaborated by the cyanobacterium Trichodesmium erythraeum and those present in the flesh of the narrow-barred Spanish mackerel Scomberomorus commersoni. Toxicon 31, 1155-1165, 1993.-The marine cyanobacterium Trichodesmium erythraeum contains toxic water-soluble material that produces signs in mice similar to those produced by water-soluble extracts of the flesh of a specimen of pelagic fish Scomberomorus commersoni from a batch that had been implicated in a poisoning resembling ciguatera. Extracts of water-soluble material from both the cyanobacterium and the fish contained toxins that were chromatographically indistinguishable. A peptide and an alkaloid were detected in partially purified extracts of the water-soluble material. In addition to this material toxic lipid-soluble material was present in some batches of T. erythraeum. Elution of this material with 9:1 chloroform: methanol using column chromatography produced material that was chromatographically indistinguishable from ciguatoxin-like material from S. commersoni and produced signs in mice similar to those produced by this material. Elution of the lipid-soluble material with 97:3 chloroform: methanol yielded a toxin resembling in its chromatographic and toxic properties a scaritoxin-like substance from S. commersoni. Other toxins with Rf values lying between that of the ciguatoxin-like material and that of the scaritoxin-like material were also detected in extracts of T. erythraeum. It is postulated that T. erythraeum is the progenitor of major toxins carried by some ciguateric fish and that water-soluble toxins released into the ambient sea water by T. erythraeum may constitute a health hazard for humans

Flourishing Interventions 2.0: a practical guide to student development

This chapter presents a practical guide for the development of flourishing students. Flourishing is defined as a positive psychological state characterised by positive emotions, engagement, positive relationships, meaning and accomplishments with various positive work/life outcomes. Within an academic setting, recent research has alluded to the relationship between flourishing students and academic performance. Similarly, flourishing students were less likely to procrastinate, had higher levels of self-control, adopted a mastery-approach towards their goals and reported higher levels of academic performance. Further, flourishing students has a higher probability to experience fruitful and rewarding careers. Therefore, it is imperative to equip students with the necessary skills to enhance flourishing early in their academic careers. This chapter aims to present the theoretical implications of flourishing as well as to provide a practical approach towards developing flourishing students

Variation in the toxins present in ciguateric narrow-barred Spanish mackerel, Scomberomorus commersoni

R. Endean, J. K. Griffith, J. J. Robins, L. E. Llewellyn and S. A. Monks. Variation in the toxins present in ciguateric narrow-barred Spanish mackerel, Scomberomorus commersoni. Toxicon 31, 723-732, 1993.-Water-soluble and lipid-soluble toxins present in six specimens of Scomberomorus commersoni captured in subtropical Queensland were compared with those detected in a specimen studied earlier. All specimens were from batches that had been involved in human poisonings. All specimens contained significant amounts of potent water-soluble toxins, the most important of which in terms of contribution to the lethal potency of fish flesh was unidentified toxic material which tested positively for alkaloids. All specimens contained lipid-soluble toxins including ciguatoxin-like and scaritoxin-like material, the latter usually predominating. Amounts of water-soluble toxins with lethal potencies ranging from 14.9 MU to 115 MU/100 g of flesh and of lipid-soluble toxins with lethal potencies ranging from 8.8 MU to 39.9 MU/100 g of flesh were found. (A mouse unit, MU, is the minimum amount of toxic material expressed in g required to kill a 20 g mouse within 24 hr following i.p. injection.) The lethal potency of water-soluble toxins per g of fish exceeded that of lipid-soluble toxins per g of fish for five of the seven specimens of S. commersoni now investigated. Based on a lethal dose to humans of 2500 MU all fishes contained lethal amounts of toxic material. The relative amounts of water-soluble and lipid-soluble toxins present in the flesh of a specimen of S. commersoni were altered by different cooking procedures

Positive psychological interventions aimed at managing territorial behaviours within the organisational context

ownership for the purpose of claiming, maintaining or protecting an individual’s target of ownership. Very limited research exists regarding evidence-based positive psychological intervention strategies aimed at the management of territorial behaviours within organisational contexts. The aim of this chapter is to present the theoretical implications of territoriality as well as to provide evidence-based intervention strategies, from a positive psychology perspective, towards managing territorial behaviours within the organisational context. Keywords Positive psychological interventions Psychological ownership Territoriality Infringement Possessio

Positive journal writing across multi-cultural contexts: a protocol for practice

The purpose of this chapter is to offer a self-directed, evidence-based, positive psychological intervention protocol for positive journaling. Specifically, the chapter proposes that effective positive journaling interventions require at least four distinct phases: (1) exposure to a range of positive emotions and discussion of these emotions in context; (2) offering an initial guided/structured writing intervention over three days in the form of a ‘positive journal’; (3) follow up support and discussion of the intervention to evaluate suitability; and finally (4) if appropriate, directing the client towards self-directed ‘ownership’ of this tool by encouraging the maintenance of a regular positive journal practice. In recommending this protocol, the present chapter draws upon extant qualitative and quantitative studies in support of positive writing, as well as highlighting its potential value across multi-cultural contexts. Also offered is a theoretical reflection upon the ways in which such a tool might be further developed to incorporate broader aspects of the field of positive psychology, beyond positive emotions, such as self-compassion or character strengths