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Identifying the dead after mass disasters is a crucial part of grieving. Here’s how forensic experts do it
No full textAs Russian forces withdraw from parts of Ukraine, reports have emerged of thousands dead and mass graves holding unknown numbers of bodies..
Flies, maggots and methamphetamine: how insects can reveal drugs and poisons at crime scenes.
No full textThe oldest book of zoology was published on clay tablets more than 3,600 years ago, and reported the names of 396 types of wild animals known at the time. Ten of them were different kinds of fly..
Comparison of auditory steady-state responses with conventional audiometry in older adults
Get PDFBehavioral measures, such as pure-tone audiometry (PTA), are commonly used to determine hearing thresholds, however, PTA does not always provide reliable hearing information in difficult to test individuals. Therefore, objective measures of hearing sensitivity that require little-to-no active participation from an individual are needed to facilitate the detection and treatment of hearing loss in difficult to test people. Investigation of the reliability of the auditory steady-state response (ASSR) for measuring hearing thresholds in older adults is limited. This study aimed to investigate if ASSR can be a reliable, objective measure of frequency specific hearing thresholds in older adults. Hearing thresholds were tested at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz in 50 participants aged between 60 and 85 years old, using automated PTA and ASSR. Hearing thresholds obtained from PTA and ASSR were found to be significantly correlated (p < .001) in a cohort consisting of participants with normal hearing or mild hearing loss. ASSR thresholds were significantly higher as compared to PTA thresholds, but for the majority of cases the difference remained within the clinically acceptable range (15 dB). This study provides some evidence to suggest that ASSR can be a valuable tool for estimating objective frequency-specific hearing thresholds in older adults and indicate that ASSR could be useful in creating hearing treatment plans for older adults who are unable to complete behavioral PTA. Further research on older adults is required to improve the methodological features of ASSR to increase consistency and reliability, as well as minimize some of the limitations associated with this technique
Parent and child mental health during COVID-19 in Australia: The role of pet attachment
Get PDFRestrictions, social isolation, and uncertainty related to the global COVID-19 pandemic have disrupted the ways that parents and children maintain family routines, health, and wellbeing. Companion animals (pets) can be a critical source of comfort during traumatic experiences, although changes to family routines, such as those caused by COVID-19, can also bring about challenges like managing undesirable pet behaviours or pet-human interactions. We aimed to examine the relationship between pet attachment and mental health for both parents and their children during the COVID-19 pandemic in Australia. A total of 1,034 parents living with a child under 18 years and a cat or dog completed an online cross-sectional survey between July and October 2020. Path analysis using multivariate linear regression was conducted to examine associations between objective COVID-19 impacts, subjective worry about COVID-19, human-pet attachment, and mental health. After adjusting for core demographic factors, stronger pet-child attachment was associated with greater child anxiety (parent-reported, p < .001). Parent-pet attachment was not associated with self-reported psychological distress (p = .42), however, parents who reported a strong emotional closeness with their pet reported greater psychological distress (p = .002). Findings highlight the role of pets during times of change and uncertainty. It is possible that families are turning to animals as a source of comfort, during a time when traditional social supports are less accessible. Alternatively, strong pet attachment is likely to reflect high levels of empathy, which might increase vulnerability to psychological distress. Longitudinal evidence is required to delineate the mechanisms underpinning pet attachment and mental health
Bioturbation by echidna (Tachyglossus aculeatus) in a forest habitat, south-western Australia
Get PDFBioturbation by digging animals is important for key forest ecosystem processes such as soil turnover, decomposition, nutrient cycling, water infiltration, seedling recruitment, and fungal dispersal. Despite their widespread geographic range, little is known about the role of the short-beaked echidna (Tachyglossus aculeatus) in forest ecosystems. We measured the density and size of echidna diggings in the Northern Jarrah Forest, south-western Australia, to quantify the contribution echidna make to soil turnover. We recorded an overall density of 298 echidna diggings per hectare, 21% of which were estimated to be less than 1 month old. The average size of digs was 50 ± 25 mm in depth and 160 ± 61 mm in length. After taking into account seasonal digging rates, we estimated that echidnas turn over 1.23 tonnes of soil ha−1 year−1 in this forest, representing an important role in ecosystem dynamics. Our work contributes to the growing body of evidence quantifying the role of these digging animals as critical ecosystem engineers. Given that the echidna is the only Australian digging mammal not severely impacted by population decline or range reduction, its functional contribution to health and resilience of forest ecosystems is increasingly important due to the functional loss of most Australian digging mammals
The key to the future lies in the past: Insights from grain legume domestication and improvement should inform future breeding strategies
Get PDFCrop domestication is a co-evolutionary process that has rendered plants and animals significantly dependent on human interventions for survival and propagation. Grain legumes have played an important role in the development of Neolithic agriculture some 12,000 years ago. Despite being early companions of cereals in the origin and evolution of agriculture, the understanding of grain legume domestication has lagged behind that of cereals. Adapting plants for human use has resulted in distinct morpho-physiological changes between the wild ancestors and domesticates, and this distinction has been the focus of several studies aimed at understanding the domestication process and the genetic diversity bottlenecks created. Growing evidence from research on archeological remains, combined with genetic analysis and the geographical distribution of wild forms, has improved the resolution of the process of domestication, diversification and crop improvement. In this review, we summarize the significance of legume wild relatives as reservoirs of novel genetic variation for crop breeding programs. We describe key legume features, which evolved in response to anthropogenic activities. Here, we highlight how whole genome sequencing and incorporation of omics-level data have expanded our capacity to monitor the genetic changes accompanying these processes. Finally, we present our perspective on alternative routes centered on de novo domestication and re-domestication to impart significant agronomic advances of novel crops over existing commodities. A finely resolved domestication history of grain legumes will uncover future breeding targets to develop modern cultivars enriched with alleles that improve yield, quality and stress tolerance
Industrial action in Western Australia's public sector essential services
Get PDFWorkers in essential services professions protect the safety, health or welfare of a community. Any disruption to the operation of essential services can mean that communities are unable to function effectively. For this reason, additional complications arise when people working in essential fields look to take industrial action. This thesis reflects on the often-competing interests of protecting essential service workers’ liberty to take industrial action (or right to strike) while upholding the life, safety, health or welfare of the community. The purpose of this thesis is to consider whether essential service workers in Western Australia’s Public Sector have sufficient freedom to access their right to strike; or if legislation is overly restrictive in this regard. Secondary purposes to this thesis include consideration of whether Australia’s Federal industrial relations system is more facilitative than Western Australia’s industrial relations system for essential service workers taking industrial action, and, whether some essential service professions should have greater limitations than others when taking industrial action. These issues will be addressed in light of the industrial situation for professions such as policing, teaching, firefighting and nursing. A macro assessment of the historical and present approaches to industrial action taken by essential service professions in Western Australia and Australia will be presented. The macro assessment suggests that industrial actions by core essential services is rarely taken, and, when done, it is reactive and the outcome of sustained frustrations over pay and working conditions. A comparative analysis of Australia’s compliance with international labour obligations on this issue highlights several shortcomings in Western Australia’s labour laws. These shortcomings mean that there is a need for Western Australia to enhance its proactive dispute resolution mechanisms to facilitate better access to the right to strike, and to bring domestic laws into better compliance with international obligations
Structure formation and identification in geometrically driven soft matter systems
Get PDFSubdividing space through interfaces leads to many space partitions that are relevant to soft matter self-assembly. Prominent examples include cellular media, e.g. soap froths, which are bubbles of air separated by interfaces of soap and water, but also more complex partitions such as bicontinuous minimal surfaces.
Using computer simulations, this thesis analyses soft matter systems in terms of the relationship between the physical forces between the system’s constituents and the structure of the resulting interfaces or partitions. The focus is on two systems, copolymeric self-assembly and the so-called Quantizer problem, where the driving force of structure formation, the minimisation of the free-energy, is an interplay of surface area minimisation and stretching contributions, favouring cells of uniform thickness.
In the first part of the thesis we address copolymeric phase formation with sharp interfaces. We analyse a columnar copolymer system “forced” to assemble on a spherical surface, where the perfect solution, the hexagonal tiling, is topologically prohibited. For a system of three-armed copolymers, the resulting structure is described by solutions of the so-called Thomson problem, the search of minimal energy configurations of repelling charges on a sphere. We find three intertwined Thomson problem solutions on a single sphere, occurring at a probability depending on the radius of the substrate.
We then investigate the formation of amorphous and crystalline structures in the Quantizer system, a particulate model with an energy functional without surface tension that favours spherical cells of equal size. We find that quasi-static equilibrium cooling allows the Quantizer system to crystallise into a BCC ground state, whereas quenching and non-equilibrium cooling, i.e. cooling at slower rates then quenching, leads to an approximately hyperuniform, amorphous state. The assumed universality of the latter, i.e. independence of energy minimisation method or initial configuration, is strengthened by our results. We expand the Quantizer system by introducing interface tension, creating a model that we find to mimic polymeric micelle systems: An order-disorder phase transition is observed with a stable Frank-Caspar phase.
The second part considers bicontinuous partitions of space into two network-like domains, and introduces an open-source tool for the identification of structures in electron microscopy images. We expand a method of matching experimentally accessible projections with computed projections of potential structures, introduced by Deng and Mieczkowski (1998). The computed structures are modelled using nodal representations of constant-mean-curvature surfaces. A case study conducted on etioplast cell membranes in chloroplast precursors establishes the double Diamond surface structure to be dominant in these plant cells. We automate the matching process employing deep-learning methods, which manage to identify structures with excellent accuracy
The relationship among avian influenza, gut microbiota and chicken immunity: An updated overview
Get PDFThe alimentary tract in chickens plays a crucial role in immune cell formation and immune challenges, which regulate intestinal flora and sustain extra-intestinal immunity. The interaction between pathogenic microorganisms and the host commensal microbiota as well as the variety and integrity of gut microbiota play a vital role in health and disease conditions. Thus, several studies have highlighted the importance of gut microbiota in developing immunity against viral infections in chickens. The gut microbiota (such as different species of Lactobacillus, Blautia Bifidobacterium, Faecalibacterium, Clostridium XlVa, and members of firmicutes) encounters different pathogens through different mechanisms. The digestive tract is a highly reactive environment, and infectious microorganisms can disturb its homeostasis, resulting in dysbiosis and mucosal infections. Avian influenza viruses (AIV) are highly infectious zoonotic viruses that lead to severe economic losses and pose a threat to the poultry industry worldwide. AIV is a challenging virus that affects gut integrity, disrupts microbial homeostasis and induces inflammatory damage in the intestinal mucosa. H9N2 AIV infection elevates the expression of proinflammatory cytokines, such as interferon (IFN-γ and IFNα) and interleukins (IL-17A and IL-22), and increases the proliferation of members of proteobacteria, particularly Escherichia coli. On the contrary, it decreases the proliferation of certain beneficial bacteria, such as Enterococcus, Lactobacillus and other probiotic microorganisms. In addition, H9N2 AIV decreases the expression of primary gel-forming mucin, endogenous trefoil factor family peptides and tight junction proteins (ZO-1, claudin 3, and occludin), resulting in severe intestinal damage. This review highlights the relationship among AIV, gut microbiota and immunity in chicken
Ontogeny can provide insight into the roles of natural and sexual selection in cricket cuticular hydrocarbon evolution
No full textThe often complex cocktails of hydrocarbon compounds found on the cuticles of insects can serve both naturally and sexually selected functions, contributing to an individual's ability to withstand water loss and attract mating partners. However, whether natural and sexual selection act synergistically or antagonistically on a species' cuticular hydrocarbon (CHC) profile remains unclear. Here, we examined the ontogeny of the CHC profile in a species of cricket, Teleogryllus oceanicus, while manipulating humidity during development. We predicted that juvenile crickets should produce only those compounds that contribute to desiccation resistance, while those compounds contributing specifically to male attractiveness should be produced only at sexual maturity. Further, if attractive CHCs come at a cost to desiccation resistance as predicted by some models of sexual selection, then males reared under low humidity should be constrained to invest less in attractive CHCs. Crickets reared under low humidity produced more long-chain methyl-branched alkanes, alkenes and alkadienes than did crickets reared under high humidity. The abundance of n-alkanes was unaffected by humidity treatment. Sexual dimorphism in the CHC profile was not apparent until adult emergence and became exaggerated 10 days after emergence, when crickets were sexually mature. Males produced more of the same compounds that were increased in both sexes under low humidity, but the humidity treatment did not interact with sex in determining CHC abundance. The data suggest that CHC profiles which protect crickets from desiccation might have synergistic effects on male attractiveness, as there was no evidence to suggest males trade-off a CHC profile produced in response to low humidity for one associated with sexual signalling