Localization with ghost elimination of emitters via time-delay-of-arrival measurements

This paper investigates the theoretical requirements for unique localization of multiple emitters using time delay of arrival(TDoA) subjected to the data-association problem. Specifically, an examination is carried out to find the necessary fundamental requirements to solve the so-called ghost node problem pertaining to sensor arrays.

Localization with ghost elimination of emitters via time-of-arrival measurements

This paper looks at the theoretical conditions underpinning unique localization of synchronized multiple emitters using Time-of-Arrival measurements subjected to the data-association problem. The necessary fundamental requirements to solve the so-called ghost node problem associated with sensor arrays are examined. We derive a measurement bound for ideal situations and the underlying concepts are illustrated via simulations.

Mohair research update 19 : incisor teeth, mohair production and Angora goat management

Goats and other ruminants have two successive dentitions, the deciduous dentition (n = 20) and permanent dentition (n = 32). Upper incisors are absent and are replaced by a very thick connective tissue pad (palate) against which the lower incisors close.

Migrant stones : stonewalling with ghost muscle

A series of events: workshop in the collective memory and response to the stones of SW Vic, followed by a stone walling workshop led by professional stone wallers, and the construction of a permanent section of stone wall on the foreshore of Lake Bolac.

Analysis of growth and stable isotopes in teeth of male Australian fur seals reveals interannual variability in prey resources

To detect and monitor long-term ecosystem responses to environmental variability, managers must utilize reliable and quantitative techniques to predict future ecosystem responses. Canine teeth from 67 male Australian fur seals (aged 2-19 yr), collected at Seal Rocks, between 1967 and 1976, were measured for relative growth within the dentine growth layer groups (GLGs), as an index of body growth. Fluctuations in relative growth were apparent during 1956-1971, suggesting interannual variation in prey resources within Bass Strait. These were positively correlated with the Southern Oscillation Index and negatively with the Indian Ocean Subtropical Dipole, both on a 2 yr lag. The observed delay may reflect the time required for the nutrient cascade to filter through to the predominantly benthic prey of Australian fur seals. Stable isotope analysis (?15N/?13C) was also used to investigate whether fluctuations in growth were associated with differences in diet. Relative growth was found to be negatively correlated with ?15N, suggesting years of greater resource availability may be associated with individuals consuming proportionally more prey biomass of lower isotopic value. This study demonstrates that fluctuations in the dentine GLGs of male Australian fur seals are related to environmental parameters, suggesting variation in body growth is mediated by changes in prey resources

Ghost muscle: stonewalling teams past and present

An imaginative arts project inspired by the Volcanic Plains region of Western Victoria will be showcased in Warrnambool this week where participants will also be able to experience the art of dry stone walling. The aim is to imagine the life of the stones and to re-perform and experience what it might have been like to work alongside a team of stonewallers from the late 1800's out in the fields producing about 30 meters of wall per day. This imaginary archaeology provides lesson in the doing of our ongoing relationship to the land and to place and place-making.

Teeth Tales: a community-based child oral health promotion trial with migrant families in Australia

OBJECTIVES: The Teeth Tales trial aimed to establish a model for child oral health promotion for culturally diverse communities in Australia. DESIGN: An exploratory trial implementing a community-based child oral health promotion intervention for Australian families from migrant backgrounds. Mixed method, longitudinal evaluation. SETTING: The intervention was based in Moreland, a culturally diverse locality in Melbourne, Australia. PARTICIPANTS: Families with 1-4-year-old children, self-identified as being from Iraqi, Lebanese or Pakistani backgrounds residing in Melbourne. Participants residing close to the intervention site were allocated to intervention. INTERVENTION: The intervention was conducted over 5 months and comprised community oral health education sessions led by peer educators and follow-up health messages. OUTCOME MEASURES: This paper reports on the intervention impacts, process evaluation and descriptive analysis of health, knowledge and behavioural changes 18 months after baseline data collection. RESULTS: Significant differences in the Debris Index (OR=0.44 (0.22 to 0.88)) and the Modified Gingival Index (OR=0.34 (0.19 to 0.61)) indicated increased tooth brushing and/or improved toothbrushing technique in the intervention group. An increased proportion of intervention parents, compared to those in the comparison group reported that they had been shown how to brush their child's teeth (OR=2.65 (1.49 to 4.69)). Process evaluation results highlighted the problems with recruitment and retention of the study sample (275 complete case families). The child dental screening encouraged involvement in the study, as did linking attendance with other community/cultural activities. CONCLUSIONS: The Teeth Tales intervention was promising in terms of improving oral hygiene and parent knowledge of tooth brushing technique. Adaptations to delivery of the intervention are required to increase uptake and likely impact. A future cluster randomised controlled trial would provide strongest evidence of effectiveness if appropriate to the community, cultural and economic context. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12611000532909).

Human threats to sandy beaches: a meta-analysis of ghost crabs illustrates global anthropogenic impacts

Beach and coastal dune systems are increasingly subjected to a broad range of anthropogenic pressures that on many shorelines require significant conservation and mitigation interventions. But these interventions require reliable data on the severity and frequency of adverse ecological impacts. Such evidence is often obtained by measuring the response of 'indicator species'.Ghost crabs are the largest invertebrates inhabiting tropical and subtropical sandy shores and are frequently used to assess human impacts on ocean beaches. Here we present the first global meta-analysis of these impacts, and analyse the design properties and metrics of studies using ghost-crabs in their assessment. This was complemented by a gap analysis to identify thematic areas of anthropogenic pressures on sandy beach ecosystems that are under-represented in the published literature.Our meta-analysis demonstrates a broad geographic reach, encompassing studies on shores of the Pacific, Indian, and Atlantic Oceans, as well as the South China Sea. It also reveals what are, arguably, two major limitations: i) the near-universal use of proxies (i.e. burrow counts to estimate abundance) at the cost of directly measuring biological traits and bio-markers in the organism itself; and ii) descriptive or correlative study designs that rarely extend beyond a simple 'compare and contrast approach', and hence fail to identify the mechanistic cause(s) of observed contrasts.Evidence for a historically narrow range of assessed pressures (i.e., chiefly urbanisation, vehicles, beach nourishment, and recreation) is juxtaposed with rich opportunities for the broader integration of ghost crabs as a model taxon in studies of disturbance and impact assessments on ocean beaches. Tangible advances will most likely occur where ghost crabs provide foci for experiments that test specific hypotheses associated with effects of chemical, light and acoustic pollution, as well as the consequences of climate change (e.g. species range shifts).

Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis

SIQUEIRA JR. et al. Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod., v. 104, n. 1, p. 122-130, 2007.

ESR dating of pleistocene mammal teeth and its implications for the biostratigraphy and geological evolution of the coastal plain, Rio Grande do Sul, southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)