222 research outputs found

    New disease outbreak affects two dominant sea urchin species associated with Australian temperate reefs

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    Diseases of sea urchins have been implicated in dramatic transitions of marine ecosystems. Although no definitive causal agent has been found for many of these outbreaks, mostare hypothesised to be waterborne and bacterial. Here we show the first report of a novel diseaseaffecting at least 2 species of urchins off the south-eastern coast of Australia. The aetiologicalagent, identified via a range of molecular techniques, immuno-histology and inoculation experi-ments, was found to be the opportunistic pathogen Vibrio anguillarum . The disease appears to betemperature-dependent, with a faster transmission rate and increase in prevalence during ex -perimental trials conducted at higher temperatures. Furthermore, analysis of long-term field datasuggests that it may have already reached epidemic proportions. With the increases in ocean temperatures brought about by climate change, this novel urchin disease may pose a severe problem for the organisms associated with the temperate reefs off Australia and/or the ecosystemas a whole.Diseases of sea urchins have been implicated in dramatic transitions of marine ecosystems. Although no definitive causal agent has been found for many of these outbreaks, mostare hypothesised to be waterborne and bacterial. Here we show the first report of a novel diseaseaffecting at least 2 species of urchins off the south-eastern coast of Australia. The aetiologicalagent, identified via a range of molecular techniques, immuno-histology and inoculation experi-ments, was found to be the opportunistic pathogen Vibrio anguillarum . The disease appears to betemperature-dependent, with a faster transmission rate and increase in prevalence during ex -perimental trials conducted at higher temperatures. Furthermore, analysis of long-term field datasuggests that it may have already reached epidemic proportions. With the increases in ocean temperatures brought about by climate change, this novel urchin disease may pose a severe problem for the organisms associated with the temperate reefs off Australia and/or the ecosystemas a whole

    The Effect of Pollen on Coral Health

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    Corals are facing a range of threats, including rises in sea surface temperature and ocean acidification. Some now argue that keeping corals ex situ (in aquaria), may be not only important but necessary to prevent local extinction, for example in the Florida Reef Tract. Such collections or are already becoming common place, especially in the Caribbean, and may act as an ark, preserving and growing rare or endangered species in years to come. However, corals housed in aquaria face their own unique set of threats. For example, hobbyists (who have housed corals for decades) have noticed seasonal mortality is commonplace, incidentally following months of peak pollen production. So, could corals suffer from hay fever? If so, what does the future hold? In short, the answer to the first question is simple, and it is no, corals cannot suffer from hay fever, primarily because corals lack an adaptive immune system, which is necessary for the diagnosis of such an allergy. However, the threat from pollen could still be real. In this review, we explore how such seasonal mortality could play out. We explore increases in reactive oxygen species, the role of additional nutrients and how the microbiome of the pollen may introduce disease or cause dysbiosis in the holobiont

    Effects of environmental temperature on oviposition behavior in three blow fly species of forensic importance

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    A number of factors are known to affect blow fly behavior with respect to oviposition. Current research indicates that temperature is the most significant factor. However temperature thresholds for oviposition in forensically important blow flies have not been well studied. Here, the oviposition behavior of three species of forensically important blow fly species (Calliphora vicina, Calliphora vomitoria and Lucilia sericata,) was studied under controlled laboratory conditions over a range of temperatures (10 to 40°C). Lower temperature thresholds for oviposition of 16°C and 17.5°C were established for C. vomitoria and L. sericata respectively, whilst C. vicina continued to lay eggs at 10°C. C. vomitoria and L. sericata both continued to lay eggs at 40°C, whilst the highest temperature at which oviposition occurred in C. vicina was 35°C. Within these thresholds there was considerable variation in the number of surviving pupae, with a general pattern of a single peak within the range of temperatures at which eggs were laid, but with the pattern being much less distinct for L. sericataN/

    Seeking Optimum System Settings for Physical Activity Recognition on Smartwatches

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    Physical activity recognition (PAR) using wearable devices can provide valued information regarding an individual's degree of functional ability and lifestyle. In this regards, smartphone-based physical activity recognition is a well-studied area. Research on smartwatch-based PAR, on the other hand, is still in its infancy. Through a large-scale exploratory study, this work aims to investigate the smartwatch-based PAR domain. A detailed analysis of various feature banks and classification methods are carried out to find the optimum system settings for the best performance of any smartwatch-based PAR system for both personal and impersonal models. To further validate our hypothesis for both personal (The classifier is built using the data only from one specific user) and impersonal (The classifier is built using the data from every user except the one under study) models, we tested single subject validation process for smartwatch-based activity recognition.Comment: 15 pages, 2 figures, Accepted in CVC'1

    Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system

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    <p>Abstract</p> <p>Background</p> <p>Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production) to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB) are vital for autochthonous carbon fixation. The level of <it>in situ </it>production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO<sub>2 </sub>concentrations (370, 600, and 1000 ppmv), temperature (6°C, 12°C, and 18°C) and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (<it>Hydrobia ulvae, Corophium volutator </it>and <it>Hediste diversicolor) </it>in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness.</p> <p>Results</p> <p>The effects of elevated CO<sub>2 </sub>concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity.</p> <p>Conclusions</p> <p>Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore, these effects would be sufficient to affect the net metabolic balance of the coastal ecosystem, with important implications for system ecology and sustainable exploitation.</p

    EVALUATION OF RELATIONSHIPS BETWEEN REPORTED RESILIENCE AND SOLDIER OUTCOMES, Report #2: Positive Performance Outcomes in Officers (Promotions, Selections, & Professions)

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    This technical report presents an analysis of reported resilience and psychological health among the U.S. Army’s Officer Corps. The focus of the current report is on linking resilience and psychological health (hereafter referred to as R/PH) to objective outcomes associated with high job performance. Specifically, this report examines the statistical relationships between officer R/PH - as measured by the Army’s Global Assessment Tool (GAT) - and promotions to Brigadier General, early (below zone) Field Grade Officer promotions, selections for command / key billet assignments, and officers who serve in career fields that require terminal professional degrees (e.g., medical doctors, dentists, lawyers, etc). Results show that officers who have been promoted to Brigadier General are more emotionally and socially fit than their peers who have not received a promotion to Brigadier General. These officers are more engaged with their work, have higher levels of organizational trust and friendship, report lower levels of loneliness, are more optimistic, and report higher levels of positive affect and lower levels of negative affect. Each of these findings is in line with our expectations regarding R/PH and job performance, and the findings comport with a substantial body of work in the academic literature. Additionally, analysis of R/PH for officers promoted early resulted in findings similar to above. In particular, those who have been promoted below zone report higher levels of work engagement, friendship, organizational trust, optimism, and coping abilities. In short, these officers score higher on the GAT dimensions of Emotional and Social Fitness than their peers who were not promoted early (“due course” officers). Similar results were found for officers selected for command for key billet assignments. They are also more emotionally and socially fit than their peers who were not selected for command (more engaged with their work, have higher levels of organizational trust and friendship, are less lonely, are more optimistic, and report higher levels of positive affect and lower levels of negative affect). There are no practical differences in R/PH between officers serving in career fields that require terminal professional degrees and other officers serving in “line” career fields (rank-matched analysis, Captain - Colonel). In light of academic literature on the subject, this finding is somewhat surprising as it suggests that advanced professional education / training alone may not influence (or be influenced by) R/PH. When taken together, the findings above strongly suggest there is a relationship between reported resilience and psychological health and outcomes associated with high job performance, but we are currently unable to determine causality. Stated differently, we do not know if the reported R/PH contributed to the performance outcomes, or if the high job performance outcomes contributed to the reported R/PH. Further data collection and analysis over the next 12-24 months will broaden our understanding of the relationships

    Markerless monocular tracking system for guided external eye surgery

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    This paper presents a novel markerless monocular tracking system aimed at guiding ophthalmologists during external eye surgery. This new tracking system performs a very accurate tracking of the eye by detecting invariant points using only textures that are present in the sclera, i.e., without using traditional features like the pupil and/or cornea reflections, which remain partially or totally occluded in most surgeries. Two known algorithms that compute invariant points and correspondences between pairs of images were implemented in our system: Scalable Invariant Feature Transforms (SIFT) and Speed Up Robust Features (SURF). The results of experiments performed on phantom eyes show that, with either algorithm, the developed system tracks a sphere at a 360◦ rotation angle with an error that is lower than 0.5%. Some experiments have also been carried out on images of real eyes showing promising behavior of the system in the presence of blood or surgical instruments during real eye surgery. © 2014 Elsevier Ltd. All rights reserved.Monserrat Aranda, C.; Rupérez Moreno, MJ.; Alcañiz Raya, ML.; Mataix, J. (2014). Markerless monocular tracking system for guided external eye surgery. Computerized Medical Imaging and Graphics. 38(8):785-792. doi:10.1016/j.compmedimag.2014.08.001S78579238

    Conducting a drought-specific THIRA (Threat and Hazard Identification and Risk Assessment): A powerful tool for integrating all-hazard mitigation and drought planning efforts to increase drought mitigation quality

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    In the United States, drought is the second costliest natural disaster, which leads to the need for increased drought mitigation efforts over time. However, drought planning has lagged behind other hazard mitigation efforts, which is likely due to the lack of a national drought planning policy. Although the Federal Emergency Management Agency (FEMA) requires all jurisdictions have a hazard mitigation plan (HMP) to receive pre-disaster mitigation funds, drought has only recently been a requirement in HMPs. In 2012, Nebraska witnessed its worse drought in recent history, which exposed the gaps in drought planning effectiveness at all jurisdictional levels. To address potential drought planning gaps, we developed, conducted, and evaluated a Threat and Hazard Identification and Risk Assessment (THIRA), a FEMA risk assessment process, which solely focused on drought. This drought-specific THIRA consisted of a one-day workshop in which stakeholders and agency experts from the Platte River Basin in Nebraska worked collaboratively to determine the necessary resources for successfully managing a worst-case drought scenario in the region. We analyzed the findings of this workshop and compared them against the current drought planning activities in the Platte River Basin and found that the current drought planning activities would not be effective against a worst-case drought, in terms of reducing drought vulnerability and increasing preparedness and response efforts. Our use of a drought-specific THIRA and drought plan evaluation provides both a quality process to increase drought mitigation efforts and a process to strengthen the integration between stand-alone drought plans and hazard mitigation plans

    Evidence for rapid, tide-related shifts in the microbiome of the coral Coelastrea aspera

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    Shifts in the microbiome of the intertidal coral Coelastrea aspera (formally known as Goniastrea aspera) from Phuket, Thailand were noted over the course of a four day period of spring tides. During this time corals were naturally exposed to high temperatures, intense solar radiation, sub-aerial exposure and tidally-induced water fluxes. Analysis of the 16S microbiome highlighted that the corals harbored both ‘core and/or stable’ communities and those which appeared to be more ‘transient and/or sporadic’. Abundances of the transient or sporadic associates were likely to have been governed by tidally-induced variations in mucus thickness and water fluxes. The core or more stable members may have been key factors in determining coral health, although more research is needed to confirm the exact function they play in this regard. Similar to other studies, strong shifts in the bacterial community were observed, even over the short temporal scale examined here. However, we also show significant differences in the timing of these shifts between the two age-groups of corals studied. More rapid changes (within two days of sub-aerial exposure) occurred within the 4y old colonies, but a slightly delayed response was observed in the 10y old colonies, whereby the microbial associates only changed after 4 days. We hypothesize that these shifts are age related and could be influenced by the observed baseline differences in the microbiome of the 4 and 10 year old corals, bacteria-bacteria interactions, and/or host energetics

    On the complexity of resource-bounded logics

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    We revisit decidability results for resource-bounded logics and use decision problems for vector addition systems with states (VASS) to characterise the complexity of (decidable) model-checking problems. We show that the model-checking problem for the logic RB+-ATL is 2EXPTIME-complete by using recent results on alternating VASS. In addition, we establish that the model-checking problem for RBTL is decidable and has the same complexity as for RBTL* (the extension of RBTL with arbitrary path formulae), namely EXPSPACE-complete, proving a new decidability result as a by-product of the approach. Finally, we establish that the model-checking problem for RB+-ATL* is decidable by a reduction to parity games, and show how to synthesise values for resource parameters
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