(Table 1) Peak intensities and stable carbon and oxygen isotope ratios of various diagenetic carbonates of ODP Site 128-799

Abundant and various diagenetic carbonates were recovered from a 1084-m-thick, Quaternary to lower Miocene section at ODP Site 799 in the Japan Sea. Petrographic, XRD, SEM, EDS-chemical, and isotopic analyses revealed wide variations in occurrence and textural relations and complex mineralogy and chemistry. Diagenetic carbonates include calcite, calcium-rich rhodochrosite, iron- and manganese-rich magnesite, iron- and manganese-rich dolomite and ankerite, and iron- and manganeserich lansfordite (hydrous Mg-carbonate). Rhodochrosite commonly occurs as small, solid nodules and semi-indurated, thin layers in bioturbated, mottled sediments of Units I and II (late Miocene to Quaternary). Lansfordite occurs as unindurated nodules and layers in Unit II (late Miocene and Pliocene), whereas magnesite forms indurated beds a few centimeters thick in slightly bioturbated-to-faintly laminated sediments of Unit III (middle and late Miocene). Some rhodochrosite nodules have dark-colored, pyritic cores, and some pyrite-rhodochrosite nodules are overgrown by and included within magnesite beds. Dolomite and ankerite tend to form thick beds (>10 cm) in bedded to laminated sediments of Units III, IV, and V (early to late Miocene). Calcite occurs sporadically throughout the Site 799 sediments. The d18O values of carbonates and the interstitial waters, and the measured geothermal gradient indicate that almost all of the Site 799 carbonates are not in isotopic equilibrium with the ambient waters, but were precipitated in the past when the sediments were at shallower depths. Depths of precipitation obtained from the d18O of carbonates span from 310 to 510 mbsf for magnesite and from 60 to 580 mbsf for dolomite-ankerite. Rhodochrosite and calcite are estimated to have formed within sediments at depths shallower than 80 mbsf. Diagenetic history in the Site 799 sediments have been determined primarily by the environment of deposition; in particular, by the oxidation-reduction state of the bottom waters and the alkalinity level of the interstitial waters. Under the well-oxygenated bottom-water conditions in the late Miocene and Pliocene, manganese initially accumulated on the seafloor as hydrogenous oxides and subsequently was mobilized and reprecipitated as rhodochrosite within the shallow sulfate-reduction, sub-oxic zone. Precipitation of lansfordite occurred in the near-surface sediments with abundant organic carbon and an extremely high alkalinity during the latest Miocene and Pliocene. The lansfordite was transformed to magnesite upon burial in the depth interval 310 to 510 mbsf. Dolomite first precipitated at shallow depths in Mn-poor, anoxic, moderately biocalcareous sediments of early to late Miocene. With increasing temperature and depth, the dolomite recrystallized and reequilibrated with ambient waters at depths below about 400 mbsf.

Trace element composition of IODP Site 304-U1309 and 305-U1309 (Table A2)

IODP Site U1309 was drilled at Atlantis Massif, an oceanic core complex, at 30°N on the Mid-Atlantic Ridge (MAR). We present the results of a bulk rock geochemical study (major and trace elements) carried out on 228 samples representative of the different lithologies sampled at this location. Over 96% of Hole U1309D is made up of gabbroic rocks. Diabases and basalts cross-cut the upper part of the section; they have depleted MORB compositions similar to basalts sampled at MAR 30°N. Relics of mantle were recovered at shallow depth. Mantle peridotites show petrographic and geochemical evidence of extensive melt-rock interactions. Gabbroic rocks comprise: olivine-rich troctolites (> 70% modal olivine) and troctolites having high Mg# (82-89), high Ni (up to 2300 ppm) and depleted trace element compositions (Yb 0.06-0.8 ppm); olivine gabbros and gabbros (including gabbronorites) with Mg# of 60-86 and low trace element contents (Yb 0.125-2.5 ppm); and oxide gabbros and leucocratic dykes with low Mg# (< 50), low Ni (~65 ppm) and high trace element contents (Yb up to 26 ppm). Troctolites and gabbros are amongst the most primitive and depleted oceanic gabbroic rocks. The main geochemical characteristics of Site U1309 gabbroic rocks are consistent with a formation as a cumulate sequence after a common parental MORB melt, although (lack of systematic) downhole variations indicate that the gabbroic series were built by multiple magma injections. In detail, textural and geochemical variations in olivine-rich troctolites and gabbronorites suggest chemical interaction (assimilation?) between the parental melt and the intruded lithosphere. Site U1309 gabbroic rocks do not represent the complementary magmatic product of 30°N volcanics, although they sample the same mantle source. The bulk trace element composition of Site U1309 gabbroic rocks is similar to primitive MORB melt compositions; this implies that there was no large scale removal of melts from this gabbro section. The occurrence of such a large magmatic sequence implies that a high magmatic activity is associated with the formation of Atlantis Massif. Our results suggest that almost all melts feeding this magmatic system stays trapped into the intruded lithosphere.

Sediment and physical record of ODP Site 178-1095

Sediments recovered from a drift deposit lying along the Pacific margin of the Antarctic Peninsula, (ODP Leg 178, Site 1095) provide a physical record of the Antarctic Circumpolar Current since late Miocene time. Determination of the strength of the magnetic fabric, anisotropy of magnetic susceptibility, provides a proxy for current strength. Fabric strength declines throughout the record from high values in the late Miocene; a pronounced step occurs between 5.0 and 5.5 Ma, and values decrease more gradually since about 3.0 Ma. The mass accumulation rate of terrigenous sediment derived from the Antarctic Peninsula indicates stabilization of the Antarctic Peninsula Ice Cap prior to about 8.5 Ma.

Biostratigraphy and average linear sedimentation rate and accumulation rate of ODP Site 159-959 (Table 1)

Reconstructing the long-term evolution of organic sedimentation in the eastern Equatorial Atlantic (ODP Leg 159) provides information about the history of the climate/ocean system, sediment accumulation, and deposition of hydrocarbon-prone rocks. The recovery of a continuous, 1200 m long sequence at ODP Site 959 covering sediments from Albian (?) to the present day (about 120 Ma) makes this position a key location to study these aspects in a tropical oceanic setting. New high resolution carbon and pyrolysis records identify three main periods of enhanced organic carbon accumulation in the eastern tropical Atlantic, i.e. the late Cretaceous, the Eocene-Oligocene, and the Pliocene-Pleistocene. Formation of Upper Cretaceous black shales off West Africa was closely related to the tectonosedimentary evolution of the semi-isolated Deep Ivorian Basin north of the Côte d'Ivoire-Ghana Transform Margin. Their deposition was confined to certain intervals of the last two Cretaceous anoxic events, the early Turonian OAE2 and the Coniacian-Santonian OAE3. Organic geochemical characteristics of laminated Coniacian-Santonian shales reveal peak organic carbon concentrations of up to 17% and kerogen type I/II organic matter, which qualify them as excellent hydrocarbon source rocks, similar to those reported from other marginal and deep sea basins. A middle to late Eocene high productivity period occurred off equatorial West Africa. Porcellanites deposited during that interval show enhanced total organic carbon (TOC) accumulation and a good hydrocarbon potential associated with oil-prone kerogen. Deposition of these TOC-rich beds was likely related to a reversal in the deep-water circulation in the adjacent Sierra Leone Basin. Accordingly, outflow of old deep waters of Southern Ocean origin from the Sierra Leone Basin into the northern Gulf of Guinea favored upwelling of nutrient-enriched waters and simultaneously enhanced the preservation potential of sedimentary organic matter along the West African continental margin. A pronounced cyclicity in the carbon record of Oligocene-lower Miocene diatomite-chalk interbeds indicates orbital forcing of paleoceanographic conditions in the eastern Equatorial Atlantic since the Oligocene-Miocene transition. A similar control may date back to the early Oligocene but has to be confirmed by further studies. Latest Miocene-early Pliocene organic carbon deposition was closely linked to the evolution of the African trade winds, continental upwelling in the eastern Equatorial Atlantic, ocean chemistry and eustatic sea level fluctuations. Reduction in carbonate carbon preservation associated with enhanced carbon dissolution is recorded in the uppermost Miocene (5.82-5.2 Ma) section and suggests that the latest Miocene carbon record of Site 959 documents the influence of corrosive deep waters which formed in response to the Messinian Salinity Crisis. Furthermore, sea level-related displacement of higher productive areas towards the West African shelf edge is indicated at 5.65, 5.6, 5.55, 5.2, 4.8 Ma. In view of humid conditions in tropical Africa and a strong West African monsoonal system around the Miocene-Pliocene transition, the onset of pronounced TOC cycles at about 5.6 Ma marks the first establishment of upwelling cycles in the northern Gulf of Guinea. An amplification in organic carbon deposition at 3.3 Ma and 2.45 Ma links organic sedimentation in the tropical eastern Equatorial Atlantic to the main steps of northern hemisphere glaciation and testifies to the late Pliocene transition from humid to arid conditions in central and western African climate. Aridification of central Africa around 2.8 Ma is not clearly recorded at Site 959. However, decreased and highly fluctuating carbonate carbon concentrations are observed from 2.85 Ma on that may relate to enhanced terrigenous (eolian) dilution from Africa.

Drivers constraints and the future of off-site manufacture in Australia.

Much has been written on Off-site Manufacture (OSM) in construction, particularly regarding the perceived benefits and barriers to implementation. However, very little understanding of the state of OSM in the Australian construction industry exists. A ‘scoping study' has recently been undertaken to determine the ‘state-of-the-art’ of OSM in Australia. This involved several industry workshops, interviews and case studies across four major states of Australia. The study surveyed a range of suppliers across the construction supply-chain, incorporating the civil, commercial and housing segments of the market. This revealed that skills shortages and lack of adequate OSM knowledge are generally the greatest issues facing OSM in Australia. The drivers and constraints that emerged from the research were, in large measure, consistent with those found in the US and UK, although some Australian anomalies are evident, such as the geographical disparity of markets. A comparative analysis with similar studies in the UK and US is reported, illustrating both the drivers and constraints confronting the industry in Australia. OSM uptake into the future is however dependent on many factors, not least of which is a better understanding of the construction process and its associated costs.

Risk-based approach to the management of on-site wastewater treatment facilities

Background On-site wastewater treatment system (OWTS) siting, design and management has traditionally been based on site specific conditions with little regard to the surrounding environment or the cumulative effect of other systems in the environment. The general approach has been to apply the same framework of standards and regulations to all sites equally, regardless of the sensitivity, or lack thereof, to the receiving environment. Consequently, this has led to the continuing poor performance and failure of on-site systems, resulting in environmental and public health consequences. As a result, there is increasing realisation that more scientifically robust evaluations in regard to site assessment and the underlying ground conditions are needed. Risk-based approaches to on-site system siting, design and management are considered the most appropriate means of improvement to the current standards and codes for on-site wastewater treatment systems. The Project Research in relation to this project was undertaken within the Gold Coast City Council region, the major focus being the semi-urban, rural residential and hinterland areas of the city that are not serviced by centralised treatment systems. The Gold Coast has over 15,000 on-site systems in use, with approximately 66% being common septic tank-subsurface dispersal systems. A recent study evaluating the performance of these systems within the Gold Coast area showed approximately 90% were not meeting the specified guidelines for effluent treatment and dispersal. The main focus of this research was to incorporate strong scientific knowledge into an integrated risk assessment process to allow suitable management practices to be set in place to mitigate the inherent risks. To achieve this, research was undertaken focusing on three main aspects involved with the performance and management of OWTS. Firstly, an investigation into the suitability of soil for providing appropriate effluent renovation was conducted. This involved detailed soil investigations, laboratory analysis and the use of multivariate statistical methods for analysing soil information. The outcomes of these investigations were developed into a framework for assessing soil suitability for effluent renovation. This formed the basis for the assessment of OWTS siting and design risks employed in the developed risk framework. Secondly, an assessment of the environmental and public health risks was performed specifically related the release of contaminants from OWTS. This involved detailed groundwater and surface water sampling and analysis to assess the current and potential risks of contamination throughout the Gold Coast region. Additionally, the assessment of public health risk incorporated the use of bacterial source tracking methods to identify the different sources of fecal contamination within monitored regions. Antibiotic resistance pattern analysis was utilised to determine the extent of human faecal contamination, with the outcomes utilised for providing a more indicative public health assessment. Finally, the outcomes of both the soil suitability assessment and ground and surface water monitoring was utilised for the development of the integrated risk framework. The research outcomes achieved through this project enabled the primary research aims and objects to be accomplished. This in turn would enable Gold Coast City Council to provide more appropriate assessment and management guidelines based on robust scientific knowledge which will ultimately ensure that the potential environmental and public health impacts resulting from on-site wastewater treatment is minimised. As part of the implementation of suitable management strategies, a critical point monitoring program (CPM) was formulated. This entailed the identification of the key critical parameters that contribute to the characterised risks at monitored locations within the study area. The CPM will allow more direct procedures to be implemented, targeting the specific hazards at sensitive areas throughout Gold Coast region.

Effect of outdoor site location on calculated I/O ratios

Motor vehicle emissions have been identified as one of the major contributors of fine and ultrafine particles (UFP) in urban areas. Schools located near major roads could potentially be exposed to high levels of UPFs and school classroom is an important microenvironment where significant exposure to UFPs is likely to occur. Most of the research conducted to date has investigated the relationship between indoor and outdoor particle number concentration (PNC) in schools based on one outdoor location, which may introduce a level of error when calculating the variation of total UPFs, and can result in the underestimation or overestimation of indoor to outdoor (I/O) ratio values.

Evaluation of the cost-effectiveness of strategies claiming to reduce the risk of surgical site infections following primary total hip arthroplasty

Background Total hip arthroplasty (THA) is a commonly performed procedure and numbers are increasing with ageing populations. One of the most serious complications in THA are surgical site infections (SSIs), caused by pathogens entering the wound during the procedure. SSIs are associated with a substantial burden for health services, increased mortality and reduced functional outcomes in patients. Numerous approaches to preventing these infections exist but there is no gold standard in practice and the cost-effectiveness of alternate strategies is largely unknown. Objectives The aim of this project was to evaluate the cost-effectiveness of strategies claiming to reduce deep surgical site infections following total hip arthroplasty in Australia. The objectives were: 1. Identification of competing strategies or combinations of strategies that are clinically relevant to the control of SSI related to hip arthroplasty 2. Evidence synthesis and pooling of results to assess the volume and quality of evidence claiming to reduce the risk of SSI following total hip arthroplasty 3. Construction of an economic decision model incorporating cost and health outcomes for each of the identified strategies 4. Quantification of the effect of uncertainty in the model 5. Assessment of the value of perfect information among model parameters to inform future data collection Methods The literature relating to SSI in THA was reviewed, in particular to establish definitions of these concepts, understand mechanisms of aetiology and microbiology, risk factors, diagnosis and consequences as well as to give an overview of existing infection prevention measures. Published economic evaluations on this topic were also reviewed and limitations for Australian decision-makers identified. A Markov state-transition model was developed for the Australian context and subsequently validated by clinicians. The model was designed to capture key events related to deep SSI occurring within the first 12 months following primary THA. Relevant infection prevention measures were selected by reviewing clinical guideline recommendations combined with expert elicitation. Strategies selected for evaluation were the routine use of pre-operative antibiotic prophylaxis (AP) versus no use of antibiotic prophylaxis (No AP) or in combination with antibiotic-impregnated cement (AP & ABC) or laminar air operating rooms (AP & LOR). The best available evidence for clinical effect size and utility parameters was harvested from the medical literature using reproducible methods. Queensland hospital data were extracted to inform patients’ transitions between model health states and related costs captured in assigned treatment codes. Costs related to infection prevention were derived from reliable hospital records and expert opinion. Uncertainty of model input parameters was explored in probabilistic sensitivity analyses and scenario analyses and the value of perfect information was estimated. Results The cost-effectiveness analysis was performed from a health services perspective using a hypothetical cohort of 30,000 THA patients aged 65 years. The baseline rate of deep SSI was 0.96% within one year of a primary THA. The routine use of antibiotic prophylaxis (AP) was highly cost-effective and resulted in cost savings of over $1.6m whilst generating an extra 163 QALYs (without consideration of uncertainty). Deterministic and probabilistic analysis (considering uncertainty) identified antibiotic prophylaxis combined with antibiotic-impregnated cement (AP & ABC) to be the most cost-effective strategy. Using AP & ABC generated the highest net monetary benefit (NMB) and an incremental $3.1m NMB compared to only using antibiotic prophylaxis. There was a very low error probability that this strategy might not have the largest NMB (<5%). Not using antibiotic prophylaxis (No AP) or using both antibiotic prophylaxis combined with laminar air operating rooms (AP & LOR) resulted in worse health outcomes and higher costs. Sensitivity analyses showed that the model was sensitive to the initial cohort starting age and the additional costs of ABC but the best strategy did not change, even for extreme values. The cost-effectiveness improved for a higher proportion of cemented primary THAs and higher baseline rates of deep SSI. The value of perfect information indicated that no additional research is required to support the model conclusions. Conclusions Preventing deep SSI with antibiotic prophylaxis and antibiotic-impregnated cement has shown to improve health outcomes among hospitalised patients, save lives and enhance resource allocation. By implementing a more beneficial infection control strategy, scarce health care resources can be used more efficiently to the benefit of all members of society. The results of this project provide Australian policy makers with key information about how to efficiently manage risks of infection in THA.

Procuring OSM : base-line models of off-site manufacture business processes in Australia

A pressing cost issue facing construction is the procurement of off-site pre-manufactured assemblies. In order to encourage Australian adoption of off-site manufacture (OSM), a new approach to underlying processes is required. The advent of object oriented digital models for construction design assumes intelligent use of data. However, the construction production system relies on traditional methods and data sources and is expected to benefit from the application of well-established business process management techniques. The integration of the old and new data sources allows for the development of business process models which, by capturing typical construction processes involving OSM, provides insights into such processes. This integrative approach is the foundation of research into the use of OSM to increase construction productivity in Australia. The purpose of this study is to develop business process models capturing the procurement, resources and information flow of construction projects. For each stage of the construction value chain, a number of sub-processes are identified. Business Process Modelling Notation (BPMN), a mainstream business process modelling standard, is used to create base-line generic construction process models. These models identify OSM decision-making points that could provide cost reductions in procurement workflow and management systems. This paper reports on phase one of an on-going research aiming to develop a proto-type workflow application that can provide semi-automated support to construction processes involving OSM and assist in decision-making in the adoption of OSM thus contributing to a sustainable built environment.

Re-use of domain knowledge to provide confidence for adoption of off-site manufacturing for construction in Australia

Many construction industry decision-makers believe there is a lack of off-site manufacture (OSM) adoption for non-residential construction in Australia. Identification of construction business process was considered imperative in order to assist decision-makers to increase OSM utilisation. The premise that domain knowledge can be re-used to provide an intervention point in the construction process led a team of researchers to construct simple base-line process models for the complete construction process, segmented into six phases. Sixteen domain knowledge industry experts were asked to review the construction phase base-line models to answer the question “Where in the process illustrated by this base-line model phase is an OSM task?”. Through an iterative and generative process a number of off-site manufacture intervention points were identified and integrated into the process models. The re-use of industry expert domain knowledge provided suggestions for new ways to do basic tasks thus facilitating changes to current practice. It is expected that implementation of the new processes will lead to systemic industry change and thus a growth in productivity due to increased adoption of OSM.