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Residency, movement patterns, behavior and demographics of reef manta rays in Komodo National Park
Get PDFBackground
The reef manta ray (Mobula alfredi) is a globally threatened species and an iconic tourist attraction for visitors to Indonesia’s Komodo National Park (NP). In 2013, manta ray fishing was banned in Komodo NP and its surroundings, preceding the nationwide manta ray protection in 2014. Over a decade ago, a previous acoustic telemetry study demonstrated that reef manta rays had high fidelity to sites within the park, while more recent photo-identification data indicated that some individuals move up to 450 km elsewhere. Characterization of manta ray demographics, behavior, and a focused assessment on site use of popular tourism locations within the park is vital to assist the Komodo NP Management Authority formulate appropriate manta ray conservation and management policies.
Methods
This study uses a long-term library (MantaMatcher.org) of photo-identification data collected by researchers and citizen scientists to investigate manta ray demographics and habitat use within the park at four sites frequented by tour operators: Cauldron, Karang Makassar, Mawan, and Manta Alley. Residency and movements of manta rays were investigated with maximum likelihood analyses and Markov movement models.
Results
A total of 1,085 individual manta rays were identified from photographs dating from 2013 to 2018. In general, individual manta rays displayed a higher affinity to specific sites than others. The highest re-sighting probabilities came from the remote southern site, Manta Alley. Karang Makassar and Mawan are only ~5 km apart; however, manta rays displayed distinct site affinities. Exchange of individuals between Manta Alley and the two central sites (~35.5 km apart) occurred, particularly seasonally. More manta rays were recorded traveling from the south to the central area than vice versa. Female manta rays were more mobile than males. Similar demographic groups used Karang Makassar, Mawan, and Manta Alley for foraging, cleaning, cruising, or courtship activities. Conversely, a higher proportion of immature manta rays used the northern site, Cauldron, where foraging was commonly observed. Fishing gear-related injuries were noted on 56 individuals (~5%), and predatory injuries were present on 32 individuals (~3%). Tourism within the park increased from 2014 to 2017, with 34% more dive boats per survey at Karang Makassar and Mawan.
Discussion
The Komodo NP contains several distinct critical habitats for manta rays that encompass all demographics and accommodate seasonal manta ray movements. While the present study has not examined population trends, it does provide foundational data for such work. Continued research into manta ray abundance, long-range movements, and identifying and protecting other critical aggregation areas within the region is integral to securing the species’ recovery. We provide management recommendations to limit undue pressure on manta rays and their critical habitats from tourism
Genomic, morphological, and biochemical analyses of a multi-metal resistant but multi-drug susceptible strain of Bordetella petrii from hospital soil
Get PDFContamination of soil by antibiotics and heavy metals originating from hospital facilities has emerged as a major cause for the development of resistant microbes. We collected soil samples surrounding a hospital effluent and measured the resistance of bacterial isolates against multiple antibiotics and heavy metals. One strain BMCSI 3 was found to be sensitive to all tested antibiotics. However, it was resistant to many heavy metals and metalloids like cadmium, chromium, copper, mercury, arsenic, and others. This strain was motile and potentially spore-forming. Whole-genome shotgun assembly of BMCSI 3 produced 4.95 Mb genome with 4,638 protein-coding genes. The taxonomic and phylogenetic analysis revealed it, to be a Bordetella petrii strain. Multiple genomic islands carrying mobile genetic elements; coding for heavy metal resistant genes, response regulators or transcription factors, transporters, and multi-drug efflux pumps were identified from the genome. A comparative genomic analysis of BMCSI 3 with annotated genomes of other free-living B. petrii revealed the presence of multiple transposable elements and several genes involved in stress response and metabolism. This study provides insights into how genomic reorganization and plasticity results in evolution of heavy metals resistance by acquiring genes from its natural environment
Declining pollination success reinforces negative climate and fire change impacts in a serotinous, fire-killed plant
Get PDFClimate change projections predict that Mediterranean-type ecosystems (MTEs) are becoming hotter and drier and that fires will become more frequent and severe. While most plant species in these important biodiversity hotspots are adapted to hot, dry summers and recurrent fire, the Interval Squeeze framework suggests that reduced seed production (demographic shift), reduced seedling establishment after fire (post fire recruitment shift), and reduction in the time between successive fires (fire interval shift) will threaten fire killed species under climate change. One additional potential driver of accelerated species decline, however, has not been considered so far: the decrease in pollination success observed in many ecosystems worldwide has the potential to further reduce seed accumulation and thus population persistence also in these already threatened systems. Using the well-studied fire-killed and serotinous shrub species Banksia hookeriana as an example, we apply a new spatially implicit population simulation model to explore population dynamics under past (1988–2002) and current (2003–2017) climate conditions, deterministic and stochastic fire regimes, and alternative scenarios of pollination decline. Overall, model results suggest that while B. hookeriana populations were stable under past climate conditions, they will not continue to persist under current (and prospective future) climate. Negative effects of climatic changes and more frequent fires are reinforced by the measured decline in seed set leading to further reduction in the mean persistence time by 12–17%. These findings clearly indicate that declining pollination rates can be a critical factor that increases further the pressure on the persistence of fire-killed plants. Future research needs to investigate whether other fire-killed species are similarly threatened, and if local population extinction may be compensated by recolonization events, facilitating persistence in spatially structured meta-communities
Antimicrobial susceptibility and genomic analysis of Histophilus somni isolated from cases of bovine respiratory disease in Autralian feedlot cattle
No full textHistophilus somni is a prevalent commensal organism of the upper respiratory tract of cattle and a major causative agent of bovine respiratory disease (BRD) and other syndromes including myocarditis and infectious thromboembolic meningoencephalitis. This study investigated the antimicrobial susceptibility and phylogenetic relationships of H. somni isolates obtained from lung, heart, and other tissues at post-mortem as well as nasal mucosa swabs from cases of BRD in Australian feedlots (2004–2019). Broth microdilution Minimal Inhibitory Concentration (MIC) assays were determined for 19 antimicrobials using three different media (CLSI approved Veterinary Fastidious Medium [VFM], Mueller-Hinton fastidious broth medium supplemented with yeast extract [MHF-Y] and Columbia Broth [CB] supplemented with 5% lysed horse blood). For all antimicrobials, MICs obtained using CB medium were identical or within 1 dilution step of the MICs obtained for VFM and MHF-Y media. Therefore, CB may be a suitable medium for H. somni antimicrobial susceptibility testing similar to MHF-Y medium. None of the 70 Australian H. somni isolates exhibited resistance to antimicrobials with CLSI breakpoints including those commonly used in the treatment of BRD in Australia (first-line tetracyclines [chlortetracycline and oxytetracycline], second-line macrolides [tulathromycin], and third-line extended-spectrum cephalosporin [ceftiofur]). Whole-genome sequence analysis of 65 H. somni isolates for genomic single nucleotide polymorphism differences identified four phylogenetic clusters, each containing isolates from different Australian states, feedlots and tissue sources that clustered together. These findings demonstrate limited genetic diversity and the absence of significant antimicrobial resistance among Australian isolates of H. somni isolated from feedlot cattle
Chiming for the Clime: 'GLocal' dynamics and aesthetic trends in climate change poetry
Get PDFThis creative dissertation comprises a critical study of climate change poetry and a poetry collection in which I illustrate some of the influences that place my poetry in this growing body of work. Climate change poetry has emerged recently in response to calls from prominent climate activists to poets to contribute an emotional spark towards climate action. The poems that have emerged in answer to these calls manifest aesthetic innovations, such as verse journalism, which I discuss as defining characteristics of climate change poetry.
The exegesis has two main foci. First, I discuss Andrew Motion’s poetry to argue that the “integrated lyric” perspective that climate change poets, including myself, work with is contingent on the artistic representation of the climate crisis as a ‘glocal’ experience. To illustrate further, I analyse representative climate change poems from the Global North and South to examine the crosscurrent of diverging and intersecting emphases and approaches in the way poets address climate change. Second, I draw on Ramazani’s concept of “intergeneric poetry” to discuss recent climate change poems. I propose that “news poetry” and “docupoetry” (two aspects of verse journalism) are key genre defining characteristics of climate change poetry.
My creative component manifests influences from Ghanaian folklore, the news media and classical mythology to envisage the climate crisis as a global conundrum rather than the anthropogenic excesses of just a few people. I call my artistic approach the “Poetics of Interactivity.”
Ultimately, this dissertation concludes that the call for poets to respond to climate change has produced a significant body of work that manifests unique generic character. My creative component contributes to this new genre, merging some of its characteristic features with my own artistic idioms
Negentropism: An ecological theory of value
Get PDFI will contend here that it is possible, using concepts taken from the natural sciences, to point to a feature of living beings and natural phenomena that provides a fundamental locus of value. It is hoped that this method of locating value will help to ‘bridge the gap’ between economic and ecological concerns. I will discuss existing theories about the value of nature and outline an alternative theory of value that is based on the observable tendency for living things to work against the wider universe’s tendency toward entropy and increased disorder over time. These states-of-affairs in nature are objective and, in some cases, measurable, and I contend that they provide a foundation for moral value. I propose that the concept of negentropy – or negative entropy – can provide a measure of the value in living things and the things created by living things, including the products of human labour. I will investigate the suitability of a ‘negentropic’ theory of value as a basis for economic and ethical decision-making
Healthcare choices following mild traumatic brain injury in Australia
Get PDFBackground
Accurate data on the types of healthcare people seek in the early stages following mild traumatic brain injury (mTBI) in Australia is lacking. We sought to investigate the types of healthcare people seek following mTBI, including seeking no care at all; ascertain the demographic, pre- and peri-injury factors, and symptom characteristics associated with the care that people access; and examine whether choice of care is associated with symptomatic recovery and quality of life.
Methods
An online retrospective survey of Australians aged 18 to 65 years who had experienced a self-reported ‘concussion’ (mTBI) within the previous 18 months. Types of healthcare accessed were investigated, as well as those who did not seek any care. Data were analysed using frequency and percentages, chi-squared tests and logistic regression models.
Results
A total of 201 respondents had experienced a self-reported ‘concussion’ but 21.4% of the respondents did not seek any care. Of the 183 respondents who sought healthcare, 52.5% attended a hospital Emergency Department, 41.0% attended a general practitioner and 6.6% accessed sports-based care. Compared to their counterparts, those who had a lower level of education (p = 0.001), had experienced previous mTBI (p = 0.045) or previous mental health issues (p = 0.009) were less likely to seek healthcare, whilst those who had experienced loss of consciousness (p = 0.014), anterograde (p = 0.044) or retrograde (p = 0.009) amnesia, and symptoms including drowsiness (p = 0.005), nausea (p = 0.040), and feeling slow (p = 0.031) were more likely to seek care. Those who did not seek care were more likely to recover within one month (AOR 4.90, 95%CI 1.51 – 15.89, p = 0.008), albeit the relatively large 95%CI warrants careful interpretation. Compared to seeking care, not seeking care was not found to be significantly associated with symptom resolution nor quality of life (p > 0.05).
Conclusions
This study provides unique insight into factors associated with healthcare utilisation in the early stages following mTBI, as well as outcomes associated with choice of care, including not seeking care. Delivering targeted community education on the signs and symptoms of mTBI, and the advantages of seeking care following injury is an important step forward in the management of this challenging condition
‘A day that unites the nation': contesting historical narratives in national day discussions
No full textNational days often represent unifying narratives about nation-states. Recent calls for historical redress within settler-colonial nations, however, have been based on redefinitions of triumphalist historical narratives, incorporating darker histories of colonialisation’s ongoing effects. This has resulted in controversy about national days, especially in Australia (celebrated on the anniversary of British colonisation). Discussions about Australia's national day may show us if, and how, these competing historical narratives can be integrated into a unified national story. A critical discursive examination of Australian news media articles demonstrated the ways historical narratives were deployed to construct competing understandings of the national day’s meaning. Analysis showed how the narrative of colonisation as a force for cultural advancement was used to justify celebrating the current date. In contrast, acknowledging and reckoning with the past was positioned as crucial to moving forward, and, correspondingly, that changing the date was necessary. Respecifying the historical narrative in this way brought together a more complex, nation-building story unifying Indigenous peoples, settlers, and newer migrants in celebrating the (new?) national day. Such reimagined national stories offer potential ‘golden futures’, but risk allowing nations to continue to avoid reckoning with their dark histories, and, especially, the connection of these to present-day inequalities
Analog control circuit designs for a class of Continuous-Time Adaptive Fault-Tolerant control systems
No full textThis article is concerned with the robust adaptive fault-tolerant control (FTC) circuit designs for a class of continuous-time disturbed systems. A circuit realization method is investigated to convert the robust adaptive FTC control schemes into analog control circuits. An adaptive compensation control scheme against state-dependent and partially bounded actuator faults and disturbances is first developed to demonstrate the approach clearly, then its equivalent control circuits are implemented by using the circuit theory. Compared with simulation results achieved by MATLAB and professional circuit simulation software, the effectiveness of the proposed robust adaptive FTC circuits is validated by a rocket fairing system and a Chua’s circuit system