Differential associations of hypoxia, sleep fragmentation, and depressive symptoms with cognitive dysfunction in obstructive sleep apnea
- Alomri, Ridwan, Kennedy, Gerard, Wali, Siraj, Ahejaili, Faris, Robinson, Stephen
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Ahejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Sleep Vol. 44, no. 4 (2021), p.
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- Description: Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete cessation of breathing during sleep and increased effort to breathe. This study examined patients who underwent overnight polysomnographic studies in a major sleep laboratory in Saudi Arabia. The study aimed to determine the extent to which intermittent hypoxia, sleep disruption, and depressive symptoms are independently associated with cognitive impairments in OSA. In the sample of 90 participants, 14 had no OSA, 30 mild OSA, 23 moderate OSA, and 23 severe OSA. The findings revealed that hypoxia and sleep fragmentation are independently associated with impairments of sustained attention and reaction time (RT). Sleep fragmentation, but not hypoxia, was independently associated with impairments in visuospatial deficits. Depressive symptoms were independently associated with impairments in the domains of sustained attention, RT, visuospatial ability, and semantic and episodic autobiographical memories. Since the depressive symptoms are independent of hypoxia and sleep fragmentation, effective reversal of cognitive impairment in OSA may require treatment interventions that target each of these factors. © Sleep Research Society 2020. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Ahejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Sleep Vol. 44, no. 4 (2021), p.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete cessation of breathing during sleep and increased effort to breathe. This study examined patients who underwent overnight polysomnographic studies in a major sleep laboratory in Saudi Arabia. The study aimed to determine the extent to which intermittent hypoxia, sleep disruption, and depressive symptoms are independently associated with cognitive impairments in OSA. In the sample of 90 participants, 14 had no OSA, 30 mild OSA, 23 moderate OSA, and 23 severe OSA. The findings revealed that hypoxia and sleep fragmentation are independently associated with impairments of sustained attention and reaction time (RT). Sleep fragmentation, but not hypoxia, was independently associated with impairments in visuospatial deficits. Depressive symptoms were independently associated with impairments in the domains of sustained attention, RT, visuospatial ability, and semantic and episodic autobiographical memories. Since the depressive symptoms are independent of hypoxia and sleep fragmentation, effective reversal of cognitive impairment in OSA may require treatment interventions that target each of these factors. © Sleep Research Society 2020. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
Outfoxing the fox : effect of prey odor on fox behavior in a pastoral landscape
- Andrewartha, Tim, Evans, Maldwyn, Batson, William, Manning, Adrian, Barton, Philip
- Authors: Andrewartha, Tim , Evans, Maldwyn , Batson, William , Manning, Adrian , Barton, Philip
- Date: 2021
- Type: Text , Journal article
- Relation: Conservation Science and Practice Vol. 3, no. 12 (2021), p.
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- Description: Invasive mammalian predators have had a devastating effect on native species globally. The European red fox (Vulpes vulpes) is one such species where it has been introduced in Australia. A novel but unexplored tactic to reduce the impact of mammalian predators is the use of unrewarded prey odors to undermine the effectiveness of olfactory hunting behavior. To test the viability of unrewarded prey odors in an applied setting we investigated how foxes responded to the odors of three different prey species. We used the odors of two locally extinct native Australian marsupials; the eastern quoll (a smaller carnivore) and eastern bettong (a fungivore), and the European rabbit, an introduced herbivore. Conducting our research over a period of 3 weeks in a pastoral environment in South-eastern Australia, we used video observations of foxes' behaviors, as they encountered the different odors. We found a reduction in the number of fox visits to bettong odors in the third week. In contrast, we observed a sustained number of visits to rabbit odors. Foxes also spent more time investigating rabbit odors and displayed longer durations of vigilance behavior at quoll odors. Our results support the hypothesis that the exposure of wild foxes to unrewarded odors of novel prey species can reduce their interest in these odors, which might translate to a reduction in predation pressure. Our results also suggest, however, that olfactory pre-exposure may not be as effective at reducing fox interest in a competitor species' odor. © 2021 The Authors. Conservation Science and Practice published by Wiley Periodicals LLC. on behalf of Society for Conservation Biology
- Authors: Andrewartha, Tim , Evans, Maldwyn , Batson, William , Manning, Adrian , Barton, Philip
- Date: 2021
- Type: Text , Journal article
- Relation: Conservation Science and Practice Vol. 3, no. 12 (2021), p.
- Full Text:
- Reviewed:
- Description: Invasive mammalian predators have had a devastating effect on native species globally. The European red fox (Vulpes vulpes) is one such species where it has been introduced in Australia. A novel but unexplored tactic to reduce the impact of mammalian predators is the use of unrewarded prey odors to undermine the effectiveness of olfactory hunting behavior. To test the viability of unrewarded prey odors in an applied setting we investigated how foxes responded to the odors of three different prey species. We used the odors of two locally extinct native Australian marsupials; the eastern quoll (a smaller carnivore) and eastern bettong (a fungivore), and the European rabbit, an introduced herbivore. Conducting our research over a period of 3 weeks in a pastoral environment in South-eastern Australia, we used video observations of foxes' behaviors, as they encountered the different odors. We found a reduction in the number of fox visits to bettong odors in the third week. In contrast, we observed a sustained number of visits to rabbit odors. Foxes also spent more time investigating rabbit odors and displayed longer durations of vigilance behavior at quoll odors. Our results support the hypothesis that the exposure of wild foxes to unrewarded odors of novel prey species can reduce their interest in these odors, which might translate to a reduction in predation pressure. Our results also suggest, however, that olfactory pre-exposure may not be as effective at reducing fox interest in a competitor species' odor. © 2021 The Authors. Conservation Science and Practice published by Wiley Periodicals LLC. on behalf of Society for Conservation Biology
Regulation of the rabbit's once-daily pattern of nursing : A circadian or hourglass-dependent process?
- Apel, Sabine, Hudson, Robyn, Coleman, Grahame, Rodel, Heiko, Kennedy, Gerard
- Authors: Apel, Sabine , Hudson, Robyn , Coleman, Grahame , Rodel, Heiko , Kennedy, Gerard
- Date: 2020
- Type: Text , Journal article
- Relation: Chronobiology International Vol. 37, no. 8 (2020), p. 1151-1162
- Full Text:
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- Description: The European rabbitOryctolagus cuniculushas an unusual pattern of nursing behavior. After giving birth in a nursery burrow (or laboratory nest box), the mother immediately leaves the young and only returns to nurse for a few minutes once approximately every 24 h. It has been assumed this schedule, like a variety of other functions in the rabbit, is under circadian control. This assumption has been largely based on findings from mothers only permitted restricted access to their young once every 24 h. However, in nature and in the laboratory, mothers with free access to young show nursing visits with a periodicity shorter than 24 h, that does not correspond to other behavioral and physiological rhythms entrained to the prevailing 24 h light/dark (LD) cycle. To investigate how this unusual, apparently non-circadian pattern might be regulated, we conducted two experiments using female Dutch-belted rabbits housed individually in cages designed to automatically register feeding activity and nest box visits. In Experiment 1 we recorded the behavior of 17 mothers with free access to their young under five different LD cycles with long photo and short scotoperiods, spanning the limits of entrainment of the rabbit's circadian system. Whereas feeding rhythms were entrained by LD cycles within the rabbit's circadian range of entrainment, nursing visits showed a consistently shorter periodicity regardless of the LD regimen, largely independent of the circadian system. In Experiment 2 we tested further 12 mothers under more conventional LD 16:8 cycles but "trained" by having access to the nest box restricted to 1 h at the same time each day for the first 7 d of nursing. Mothers were then allowed free access either when their young were left in the box (n= 6), or when the litter had been permanently removed (n= 6). Mothers with pups still present returned to nurse them on the following days according to a similarly advancing pattern to the mothers of Experiment 1 despite the previous 7 d of "training" to an experimentally enforced 24 h nursing schedule as commonly used in previous studies of rabbit maternal behavior. Mothers whose pups had been removed entered the box repeatedly several times on the first day of unrestricted access, but on subsequent days did so only rarely, and at times of day apparently unrelated to the previously scheduled access. We conclude that the pattern of the rabbit's once-daily nursing visits has a periodicity largely independent of the circadian system, and that this is reset at each nursing. When nursing fails to occur nest box visits cease abruptly, with mothers making few or no subsequent visits. Together, these findings suggest that the rabbit's once-daily pattern of nursing is regulated by an hourglass-type process with a period less than 24 h that is reset at each nursing, rather than by a circadian oscillator. Such a mechanism might be particularly adaptive for rhythms of short duration that should end abruptly with a sudden change in context such as death or weaning of the young.
- Description: This work was supported by the Australian Federal Government via a Postgraduate PhD Scholarship for Sabibe Apel [APA SA 1].
- Authors: Apel, Sabine , Hudson, Robyn , Coleman, Grahame , Rodel, Heiko , Kennedy, Gerard
- Date: 2020
- Type: Text , Journal article
- Relation: Chronobiology International Vol. 37, no. 8 (2020), p. 1151-1162
- Full Text:
- Reviewed:
- Description: The European rabbitOryctolagus cuniculushas an unusual pattern of nursing behavior. After giving birth in a nursery burrow (or laboratory nest box), the mother immediately leaves the young and only returns to nurse for a few minutes once approximately every 24 h. It has been assumed this schedule, like a variety of other functions in the rabbit, is under circadian control. This assumption has been largely based on findings from mothers only permitted restricted access to their young once every 24 h. However, in nature and in the laboratory, mothers with free access to young show nursing visits with a periodicity shorter than 24 h, that does not correspond to other behavioral and physiological rhythms entrained to the prevailing 24 h light/dark (LD) cycle. To investigate how this unusual, apparently non-circadian pattern might be regulated, we conducted two experiments using female Dutch-belted rabbits housed individually in cages designed to automatically register feeding activity and nest box visits. In Experiment 1 we recorded the behavior of 17 mothers with free access to their young under five different LD cycles with long photo and short scotoperiods, spanning the limits of entrainment of the rabbit's circadian system. Whereas feeding rhythms were entrained by LD cycles within the rabbit's circadian range of entrainment, nursing visits showed a consistently shorter periodicity regardless of the LD regimen, largely independent of the circadian system. In Experiment 2 we tested further 12 mothers under more conventional LD 16:8 cycles but "trained" by having access to the nest box restricted to 1 h at the same time each day for the first 7 d of nursing. Mothers were then allowed free access either when their young were left in the box (n= 6), or when the litter had been permanently removed (n= 6). Mothers with pups still present returned to nurse them on the following days according to a similarly advancing pattern to the mothers of Experiment 1 despite the previous 7 d of "training" to an experimentally enforced 24 h nursing schedule as commonly used in previous studies of rabbit maternal behavior. Mothers whose pups had been removed entered the box repeatedly several times on the first day of unrestricted access, but on subsequent days did so only rarely, and at times of day apparently unrelated to the previously scheduled access. We conclude that the pattern of the rabbit's once-daily nursing visits has a periodicity largely independent of the circadian system, and that this is reset at each nursing. When nursing fails to occur nest box visits cease abruptly, with mothers making few or no subsequent visits. Together, these findings suggest that the rabbit's once-daily pattern of nursing is regulated by an hourglass-type process with a period less than 24 h that is reset at each nursing, rather than by a circadian oscillator. Such a mechanism might be particularly adaptive for rhythms of short duration that should end abruptly with a sudden change in context such as death or weaning of the young.
- Description: This work was supported by the Australian Federal Government via a Postgraduate PhD Scholarship for Sabibe Apel [APA SA 1].
Global lessons from successful rhinoceros conservation in Nepal
- Aryal, Achyut, Acharya, Krishna, Shrestha, Uttam Babu, Dhakal, Maheshwar, Raubenhiemer, David, Wright, Wendy
- Authors: Aryal, Achyut , Acharya, Krishna , Shrestha, Uttam Babu , Dhakal, Maheshwar , Raubenhiemer, David , Wright, Wendy
- Date: 2017
- Type: Text , Journal article
- Relation: Conservation Biology Vol. 31, no. 6 (2017), p. 1494-1497
- Full Text:
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- Authors: Aryal, Achyut , Acharya, Krishna , Shrestha, Uttam Babu , Dhakal, Maheshwar , Raubenhiemer, David , Wright, Wendy
- Date: 2017
- Type: Text , Journal article
- Relation: Conservation Biology Vol. 31, no. 6 (2017), p. 1494-1497
- Full Text:
- Reviewed:
Lack of effectiveness of 13-valent pneumococcal conjugate vaccination against pneumococcal carriage density in Papua New Guinean infants
- Britton, Kathryn, Pickering, Janessa, Pomat, William, de Gier, Camilla, Greenhill, Andrew
- Authors: Britton, Kathryn , Pickering, Janessa , Pomat, William , de Gier, Camilla , Greenhill, Andrew
- Date: 2021
- Type: Text , Journal article
- Relation: Vaccine Vol. 39, no. 38 (2021), p. 5401-5409
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- Description: Background: Papua New Guinea (PNG) introduced the 13-valent pneumococcal conjugate vaccine (PCV13) in 2014, with administration at 1, 2, and 3 months of age. PCV13 has reduced or eliminated carriage of vaccine types in populations with low pneumococcal carriage prevalence, carriage density and serotype diversity. This study investigated PCV13 impact on serotype-specific pneumococcal carriage prevalence, density, and serotype diversity in PNG infants, who have some of the highest reported rates of pneumococcal carriage and disease in the world. Methods: Nasopharyngeal swabs were collected at 1, 4 and 9 months of age from PCV13-vaccinated infants (n = 57) and age-/season-matched, unvaccinated infants (at approximately 1 month, n = 53; 4 months, n = 57; 9 months, n = 52). Serotype-specific pneumococcal carriage density and antimicrobial resistance genes were identified by qPCR and microarray. Results: Pneumococci were present in 89% of swabs, with 60 different serotypes and four non-encapsulated variants detected. Multiple serotype carriage was common (47% of swabs). Vaccine type carriage prevalence was similar between PCV13-vaccinated and unvaccinated infants at 4 and 9 months of age. The prevalence of non-vaccine type carriage was also similar between cohorts, with non-vaccine types present in three-quarters of samples (from both vaccinated and unvaccinated infants) by 4 months of age. The median pneumococcal carriage density was high and similar at each age group (~7.0 log10 genome equivalents/mL). PCV13 had no effect on overall pneumococcal carriage density, vaccine type density, non-vaccine type density, or the prevalence of antimicrobial resistance genes. Conclusion: PNG infants experience dense and diverse pneumococcal colonisation with concurrent serotypes from 1 month of age. PCV13 had no impact on pneumococcal carriage density, even for vaccine serotypes. The low prevalence of vaccine serotypes, high pneumococcal carriage density and abundance of non-vaccine serotypes likely contribute to the lack of PCV13 impact on carriage in PNG infants. Indirect effects of the infant PCV programs are likely to be limited in PNG. Alternative vaccines with broader coverage should be considered. © 2021 The Authors. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Andrew Greenhill" is provided in this record**
- Authors: Britton, Kathryn , Pickering, Janessa , Pomat, William , de Gier, Camilla , Greenhill, Andrew
- Date: 2021
- Type: Text , Journal article
- Relation: Vaccine Vol. 39, no. 38 (2021), p. 5401-5409
- Full Text:
- Reviewed:
- Description: Background: Papua New Guinea (PNG) introduced the 13-valent pneumococcal conjugate vaccine (PCV13) in 2014, with administration at 1, 2, and 3 months of age. PCV13 has reduced or eliminated carriage of vaccine types in populations with low pneumococcal carriage prevalence, carriage density and serotype diversity. This study investigated PCV13 impact on serotype-specific pneumococcal carriage prevalence, density, and serotype diversity in PNG infants, who have some of the highest reported rates of pneumococcal carriage and disease in the world. Methods: Nasopharyngeal swabs were collected at 1, 4 and 9 months of age from PCV13-vaccinated infants (n = 57) and age-/season-matched, unvaccinated infants (at approximately 1 month, n = 53; 4 months, n = 57; 9 months, n = 52). Serotype-specific pneumococcal carriage density and antimicrobial resistance genes were identified by qPCR and microarray. Results: Pneumococci were present in 89% of swabs, with 60 different serotypes and four non-encapsulated variants detected. Multiple serotype carriage was common (47% of swabs). Vaccine type carriage prevalence was similar between PCV13-vaccinated and unvaccinated infants at 4 and 9 months of age. The prevalence of non-vaccine type carriage was also similar between cohorts, with non-vaccine types present in three-quarters of samples (from both vaccinated and unvaccinated infants) by 4 months of age. The median pneumococcal carriage density was high and similar at each age group (~7.0 log10 genome equivalents/mL). PCV13 had no effect on overall pneumococcal carriage density, vaccine type density, non-vaccine type density, or the prevalence of antimicrobial resistance genes. Conclusion: PNG infants experience dense and diverse pneumococcal colonisation with concurrent serotypes from 1 month of age. PCV13 had no impact on pneumococcal carriage density, even for vaccine serotypes. The low prevalence of vaccine serotypes, high pneumococcal carriage density and abundance of non-vaccine serotypes likely contribute to the lack of PCV13 impact on carriage in PNG infants. Indirect effects of the infant PCV programs are likely to be limited in PNG. Alternative vaccines with broader coverage should be considered. © 2021 The Authors. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Andrew Greenhill" is provided in this record**
Interleukin-6 inhibition of peroxisome proliferator-activated receptor alpha expression is mediated by JAK2- and PI3K-induced STAT1/3 in HepG2 hepatocyte cells
- Chew, Guatsiew, Myers, Stephen, Shu-Chien, A. C., Muhammad, Tengku
- Authors: Chew, Guatsiew , Myers, Stephen , Shu-Chien, A. C. , Muhammad, Tengku
- Date: 2014
- Type: Text , Journal article
- Relation: Molecular and Cellular Biochemistry Vol. 388, no. 1-2 (2014), p. 25-37
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- Description: Interleukin-6 (IL-6) is the major activator of the acute phase response (APR). One important regulator of IL-6-activated APR is peroxisome proliferator-activated receptor alpha (PPAR
- Authors: Chew, Guatsiew , Myers, Stephen , Shu-Chien, A. C. , Muhammad, Tengku
- Date: 2014
- Type: Text , Journal article
- Relation: Molecular and Cellular Biochemistry Vol. 388, no. 1-2 (2014), p. 25-37
- Full Text:
- Reviewed:
- Description: Interleukin-6 (IL-6) is the major activator of the acute phase response (APR). One important regulator of IL-6-activated APR is peroxisome proliferator-activated receptor alpha (PPAR
Incorporating time-delays in S-System model for reverse engineering genetic networks
- Chowdhury, Ahsan, Chetty, Madhu, Nguyen, Vinh
- Authors: Chowdhury, Ahsan , Chetty, Madhu , Nguyen, Vinh
- Date: 2013
- Type: Text , Journal article
- Relation: BMC Bioinformatics Vol. 14, no. (2013), p. 1-22
- Full Text:
- Reviewed:
- Description: Background In any gene regulatory network (GRN), the complex interactions occurring amongst transcription factors and target genes can be either instantaneous or time-delayed. However, many existing modeling approaches currently applied for inferring GRNs are unable to represent both these interactions simultaneously. As a result, all these approaches cannot detect important interactions of the other type. S-System model, a differential equation based approach which has been increasingly applied for modeling GRNs, also suffers from this limitation. In fact, all S-System based existing modeling approaches have been designed to capture only instantaneous interactions, and are unable to infer time-delayed interactions. Results In this paper, we propose a novel Time-Delayed S-System (TDSS) model which uses a set of delay differential equations to represent the system dynamics. The ability to incorporate time-delay parameters in the proposed S-System model enables simultaneous modeling of both instantaneous and time-delayed interactions. Furthermore, the delay parameters are not limited to just positive integer values (corresponding to time stamps in the data), but can also take fractional values. Moreover, we also propose a new criterion for model evaluation exploiting the sparse and scale-free nature of GRNs to effectively narrow down the search space, which not only reduces the computation time significantly but also improves model accuracy. The evaluation criterion systematically adapts the max-min in-degrees and also systematically balances the effect of network accuracy and complexity during optimization. Conclusion The four well-known performance measures applied to the experimental studies on synthetic networks with various time-delayed regulations clearly demonstrate that the proposed method can capture both instantaneous and delayed interactions correctly with high precision. The experiments carried out on two well-known real-life networks, namely IRMA and SOS DNA repair network in Escherichia coli show a significant improvement compared with other state-of-the-art approaches for GRN modeling.
- Authors: Chowdhury, Ahsan , Chetty, Madhu , Nguyen, Vinh
- Date: 2013
- Type: Text , Journal article
- Relation: BMC Bioinformatics Vol. 14, no. (2013), p. 1-22
- Full Text:
- Reviewed:
- Description: Background In any gene regulatory network (GRN), the complex interactions occurring amongst transcription factors and target genes can be either instantaneous or time-delayed. However, many existing modeling approaches currently applied for inferring GRNs are unable to represent both these interactions simultaneously. As a result, all these approaches cannot detect important interactions of the other type. S-System model, a differential equation based approach which has been increasingly applied for modeling GRNs, also suffers from this limitation. In fact, all S-System based existing modeling approaches have been designed to capture only instantaneous interactions, and are unable to infer time-delayed interactions. Results In this paper, we propose a novel Time-Delayed S-System (TDSS) model which uses a set of delay differential equations to represent the system dynamics. The ability to incorporate time-delay parameters in the proposed S-System model enables simultaneous modeling of both instantaneous and time-delayed interactions. Furthermore, the delay parameters are not limited to just positive integer values (corresponding to time stamps in the data), but can also take fractional values. Moreover, we also propose a new criterion for model evaluation exploiting the sparse and scale-free nature of GRNs to effectively narrow down the search space, which not only reduces the computation time significantly but also improves model accuracy. The evaluation criterion systematically adapts the max-min in-degrees and also systematically balances the effect of network accuracy and complexity during optimization. Conclusion The four well-known performance measures applied to the experimental studies on synthetic networks with various time-delayed regulations clearly demonstrate that the proposed method can capture both instantaneous and delayed interactions correctly with high precision. The experiments carried out on two well-known real-life networks, namely IRMA and SOS DNA repair network in Escherichia coli show a significant improvement compared with other state-of-the-art approaches for GRN modeling.
Blooms of cyanobacteria in a temperate Australian lagoon system post and prior to European settlement
- Cook, Perran, Jennings, Miles, Holland, Daryl, Beardall, John, Briles, Christy, Zawadzki, Atun, Doan, Phuong, Mills, Keely, Gell, Peter
- Authors: Cook, Perran , Jennings, Miles , Holland, Daryl , Beardall, John , Briles, Christy , Zawadzki, Atun , Doan, Phuong , Mills, Keely , Gell, Peter
- Date: 2016
- Type: Text , Journal article
- Relation: Biogeosciences Vol. 13, no. 12 (2016), p. 3677-3686
- Full Text:
- Reviewed:
- Description: Blooms of noxious N2 fixing cyanobacteria such as Nodularia spumigena are a recurring problem in some estuaries; however, the historic occurrence of such blooms in unclear in many cases. Here we report the results of a palaeoecological study on a temperate Australian lagoon system (the Gippsland Lakes) where we used stable isotopes and pigment biomarkers in dated cores as proxies for eutrophication and blooms of cyanobacteria. Pigment proxies show a clear signal, with an increase in cyanobacterial pigments (echinenone, canthaxanthin and zeaxanthin) in the period coinciding with recent blooms. Another excursion in these proxies was observed prior to the opening of an artificial entrance to the lakes in 1889, which markedly increased the salinity of the Gippsland Lakes. A coincident increase in the sediment organic-carbon content in the period prior to the opening of the artificial entrance suggests that the bottom waters of the lakes were more stratified and hypoxic, which would have led to an increase in the recycling of phosphorus. After the opening of the artificial entrance, there was a ∼60-year period with low values for the cyanobacterial proxies as well as a low sediment organic-carbon content suggesting a period of low bloom activity associated with the increased salinity of the lakes. During the 1940s, the current period of re-eutrophication commenced, as indicated by a steadily increasing sediment organic-carbon content and cyanobacterial pigments. We suggest that increasing nitrogen inputs from the catchment led to the return of hypoxia and increased phosphorus release from the sediment, which drove the re-emergence of cyanobacterial blooms. © 2016 Author(s).
- Authors: Cook, Perran , Jennings, Miles , Holland, Daryl , Beardall, John , Briles, Christy , Zawadzki, Atun , Doan, Phuong , Mills, Keely , Gell, Peter
- Date: 2016
- Type: Text , Journal article
- Relation: Biogeosciences Vol. 13, no. 12 (2016), p. 3677-3686
- Full Text:
- Reviewed:
- Description: Blooms of noxious N2 fixing cyanobacteria such as Nodularia spumigena are a recurring problem in some estuaries; however, the historic occurrence of such blooms in unclear in many cases. Here we report the results of a palaeoecological study on a temperate Australian lagoon system (the Gippsland Lakes) where we used stable isotopes and pigment biomarkers in dated cores as proxies for eutrophication and blooms of cyanobacteria. Pigment proxies show a clear signal, with an increase in cyanobacterial pigments (echinenone, canthaxanthin and zeaxanthin) in the period coinciding with recent blooms. Another excursion in these proxies was observed prior to the opening of an artificial entrance to the lakes in 1889, which markedly increased the salinity of the Gippsland Lakes. A coincident increase in the sediment organic-carbon content in the period prior to the opening of the artificial entrance suggests that the bottom waters of the lakes were more stratified and hypoxic, which would have led to an increase in the recycling of phosphorus. After the opening of the artificial entrance, there was a ∼60-year period with low values for the cyanobacterial proxies as well as a low sediment organic-carbon content suggesting a period of low bloom activity associated with the increased salinity of the lakes. During the 1940s, the current period of re-eutrophication commenced, as indicated by a steadily increasing sediment organic-carbon content and cyanobacterial pigments. We suggest that increasing nitrogen inputs from the catchment led to the return of hypoxia and increased phosphorus release from the sediment, which drove the re-emergence of cyanobacterial blooms. © 2016 Author(s).
Chemical characterization of MEA degradation in PCC pilot plants operating in Australia
- Cruickshank, Alicia, Verheyen, Vincent, Adeloju, Samuel, Meuleman, Erik, Chaffee, Alan, Cottrell, Aaron, Feron, Paul
- Authors: Cruickshank, Alicia , Verheyen, Vincent , Adeloju, Samuel , Meuleman, Erik , Chaffee, Alan , Cottrell, Aaron , Feron, Paul
- Date: 2013
- Type: Text , Journal article
- Relation: Energy Procedia Vol. 37, no. (2013), p. 877-882
- Full Text:
- Reviewed:
- Description: An important step towards commercial scale post-combustion CO2 capture from coal-fired power stations is understanding solvent degradation. Laboratory scale trials have identified three main solvent degradation pathways for 30% MEA: oxidative degradation, carbamate polymerization and formation of heat stable salts. This paper probes the semi-volatile organic compounds produced from a single batch of 30% MEA which was used to capture CO2 from a black coal-fired power station (Tarong, Queensland, Australia) for approximately 700 hours, followed by 500 hours at the brown coal-fired power station (Loy Yang, Victoria, Australia). Comparisons are made between the compounds identified in this aged solvent system with MEA degradation reactions described in literature. Most of semi-volatile compounds tentatively identified by GC/MS have previously been reported in laboratory scale degradation trials. Our preliminary results show low levels of degradation products were present in samples after its use in the pilot plant at Tarong (black coal) and consequent 13 months storage, but much higher concentrations were later found in the same solvent during its at use in the pilot plant at Loy Yang Power (brown coal). Further work includes identifying the cause of poor GC/MS repeatability and investigating the relative rates of reactions described in literature. The impact of inorganic anions and dissolved metals on MEA degradation will also be explored.
- Authors: Cruickshank, Alicia , Verheyen, Vincent , Adeloju, Samuel , Meuleman, Erik , Chaffee, Alan , Cottrell, Aaron , Feron, Paul
- Date: 2013
- Type: Text , Journal article
- Relation: Energy Procedia Vol. 37, no. (2013), p. 877-882
- Full Text:
- Reviewed:
- Description: An important step towards commercial scale post-combustion CO2 capture from coal-fired power stations is understanding solvent degradation. Laboratory scale trials have identified three main solvent degradation pathways for 30% MEA: oxidative degradation, carbamate polymerization and formation of heat stable salts. This paper probes the semi-volatile organic compounds produced from a single batch of 30% MEA which was used to capture CO2 from a black coal-fired power station (Tarong, Queensland, Australia) for approximately 700 hours, followed by 500 hours at the brown coal-fired power station (Loy Yang, Victoria, Australia). Comparisons are made between the compounds identified in this aged solvent system with MEA degradation reactions described in literature. Most of semi-volatile compounds tentatively identified by GC/MS have previously been reported in laboratory scale degradation trials. Our preliminary results show low levels of degradation products were present in samples after its use in the pilot plant at Tarong (black coal) and consequent 13 months storage, but much higher concentrations were later found in the same solvent during its at use in the pilot plant at Loy Yang Power (brown coal). Further work includes identifying the cause of poor GC/MS repeatability and investigating the relative rates of reactions described in literature. The impact of inorganic anions and dissolved metals on MEA degradation will also be explored.
Increased expression of telomere-regulating genes in endurance athletes with long leukocyte telomeres
- Denham, Joshua, O'Brien, Brendan, Prestes, Priscilla, Brown, Nicholas, Charchar, Fadi
- Authors: Denham, Joshua , O'Brien, Brendan , Prestes, Priscilla , Brown, Nicholas , Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Applied Physiology Vol. 120, no. 2 (2015), p. 148-158
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
- Full Text:
- Reviewed:
- Description: Leukocyte telomeres shorten with age, and excessive shortening is associated with age-related cardiometabolic diseases. Exercise training may prevent disease through telomere length maintenance although the optimal amount of exercise that attenuates telomere attrition is unknown. Furthermore, the underlying molecular mechanisms responsible for the enhanced telomere maintenance observed in endurance athletes is poorly understood. We quantified the leukocyte telomere length and analyzed the expression of telomere-regulating genes in endurance athletes and healthy controls (both n = 61), using quantitative PCR. We found endurance athletes have significantly longer (7.1%, 208-416 nt) leukocyte telomeres and upregulated TERT (2.0-fold) and TPP1 (1.3-fold) mRNA expression compared with controls in age-adjusted analysis. The telomere length and telomere-regulating gene expression differences were no longer statistically significant after adjustment for resting heart rate and relative (V) over dotO(2 max) (all P > 0.05). Resting heart rate emerged as an independent predictor of leukocyte telomere length and TERT and TPP1 mRNA expression in stepwise regression models. To gauge whether volume of exercise was associated with leukocyte telomere length, we divided subjects into running and cycling tertiles (distance covered per week) and found individuals in the middle and highest tertiles had longer telomeres than individuals in the lowest tertile. These data emphasize the importance of cardiorespiratory fitness and exercise training in the prevention of biological aging. They also support the concept that moderate amounts of exercise training protects against biological aging, while higher amounts may not elicit additional benefits.
- Authors: Denham, Joshua , O'Brien, Brendan , Prestes, Priscilla , Brown, Nicholas , Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Applied Physiology Vol. 120, no. 2 (2015), p. 148-158
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
- Full Text:
- Reviewed:
- Description: Leukocyte telomeres shorten with age, and excessive shortening is associated with age-related cardiometabolic diseases. Exercise training may prevent disease through telomere length maintenance although the optimal amount of exercise that attenuates telomere attrition is unknown. Furthermore, the underlying molecular mechanisms responsible for the enhanced telomere maintenance observed in endurance athletes is poorly understood. We quantified the leukocyte telomere length and analyzed the expression of telomere-regulating genes in endurance athletes and healthy controls (both n = 61), using quantitative PCR. We found endurance athletes have significantly longer (7.1%, 208-416 nt) leukocyte telomeres and upregulated TERT (2.0-fold) and TPP1 (1.3-fold) mRNA expression compared with controls in age-adjusted analysis. The telomere length and telomere-regulating gene expression differences were no longer statistically significant after adjustment for resting heart rate and relative (V) over dotO(2 max) (all P > 0.05). Resting heart rate emerged as an independent predictor of leukocyte telomere length and TERT and TPP1 mRNA expression in stepwise regression models. To gauge whether volume of exercise was associated with leukocyte telomere length, we divided subjects into running and cycling tertiles (distance covered per week) and found individuals in the middle and highest tertiles had longer telomeres than individuals in the lowest tertile. These data emphasize the importance of cardiorespiratory fitness and exercise training in the prevention of biological aging. They also support the concept that moderate amounts of exercise training protects against biological aging, while higher amounts may not elicit additional benefits.
Soil reconstruction after mining fails to restore soil function in an Australian arid woodland
- Duncan, Corrine, Good, Megan, Sluiter, Ian, Cook, Simon, Schultz, Nick
- Authors: Duncan, Corrine , Good, Megan , Sluiter, Ian , Cook, Simon , Schultz, Nick
- Date: 2020
- Type: Text , Journal article
- Relation: Restoration Ecology Vol. 28, no. S1 (2020), p. A35-A43
- Full Text:
- Reviewed:
- Description: The biogeochemical properties of soils drive ecosystem function and vegetation dynamics, and hence soil restoration after mining should aim to reinstate the soil properties and hydrological dynamics of remnant ecosystems. The aim of this study is to assess soil structure in two vegetation types in an arid ecosystem, and to understand how these soil properties compare to a reconstructed soil profile after mining. In an arid ecosystem in southeast Australia, soil samples were collected at five depths (to 105 cm) from remnant woodland and shrubland sites, and sites either disturbed or totally reconstructed after mining. We assessed soil physico-chemical properties and microbial activity. Soils in the remnant arid ecosystem had coarse-textured topsoils that overlay clay horizons, which allows water to infiltrate and avoid evaporation, but also slows drainage to deeper horizons. Conversely, reconstructed soils had high sand content at subsoil horizons and high bulk density and compaction at surface layers (0–20 cm). Reconstructed soils had topsoils with higher pH and electrical conductivity. The reconstructed soils did not show increased microbial activity with time since restoration. Overall, the reconstructed soil horizons were not organized in a way that allowed rainfall infiltration and water storage, as is imperative to arid-zone ecosystem function. Future restoration efforts in arid ecosystems should focus on increasing sand content of soils near the surface, to reduce evaporative water loss and improve soil quality and plant health. © 2020 Society for Ecological Restoration
- Authors: Duncan, Corrine , Good, Megan , Sluiter, Ian , Cook, Simon , Schultz, Nick
- Date: 2020
- Type: Text , Journal article
- Relation: Restoration Ecology Vol. 28, no. S1 (2020), p. A35-A43
- Full Text:
- Reviewed:
- Description: The biogeochemical properties of soils drive ecosystem function and vegetation dynamics, and hence soil restoration after mining should aim to reinstate the soil properties and hydrological dynamics of remnant ecosystems. The aim of this study is to assess soil structure in two vegetation types in an arid ecosystem, and to understand how these soil properties compare to a reconstructed soil profile after mining. In an arid ecosystem in southeast Australia, soil samples were collected at five depths (to 105 cm) from remnant woodland and shrubland sites, and sites either disturbed or totally reconstructed after mining. We assessed soil physico-chemical properties and microbial activity. Soils in the remnant arid ecosystem had coarse-textured topsoils that overlay clay horizons, which allows water to infiltrate and avoid evaporation, but also slows drainage to deeper horizons. Conversely, reconstructed soils had high sand content at subsoil horizons and high bulk density and compaction at surface layers (0–20 cm). Reconstructed soils had topsoils with higher pH and electrical conductivity. The reconstructed soils did not show increased microbial activity with time since restoration. Overall, the reconstructed soil horizons were not organized in a way that allowed rainfall infiltration and water storage, as is imperative to arid-zone ecosystem function. Future restoration efforts in arid ecosystems should focus on increasing sand content of soils near the surface, to reduce evaporative water loss and improve soil quality and plant health. © 2020 Society for Ecological Restoration
Description of a robust interception trap for collecting airborne arthropods in climatically challenging regions
- Farrow, Roger, Greenslade, Penelope
- Authors: Farrow, Roger , Greenslade, Penelope
- Date: 2013
- Type: Text , Journal article
- Relation: Antarctic Science Vol. 25, no. 5 (2013), p. 657-662
- Full Text:
- Reviewed:
- Description: An interception trap to collect airborne arthropods under extreme weather conditions is described. The trap, constructed from durable materials, is operated by wind pressure. It consists of a funnel of fine brass gauze mounted inside a cylinder of stainless steel that rotates into the wind on a mast at 1.5 m from the ground. The gauze funnel terminates in a removable, propanol-filled, collecting bottle into which airborne material accumulates. The counterbalanced cylinder rotates around a central shaft on roller bearings and faces into the wind. Two traps were successfully operated continuously for four and five years, respectively, on sub-Antarctic Macquarie Island and have collected large numbers of airborne arthropods and other biological material over this period. © 2013 Antarctic Science Ltd.
- Description: C1
- Authors: Farrow, Roger , Greenslade, Penelope
- Date: 2013
- Type: Text , Journal article
- Relation: Antarctic Science Vol. 25, no. 5 (2013), p. 657-662
- Full Text:
- Reviewed:
- Description: An interception trap to collect airborne arthropods under extreme weather conditions is described. The trap, constructed from durable materials, is operated by wind pressure. It consists of a funnel of fine brass gauze mounted inside a cylinder of stainless steel that rotates into the wind on a mast at 1.5 m from the ground. The gauze funnel terminates in a removable, propanol-filled, collecting bottle into which airborne material accumulates. The counterbalanced cylinder rotates around a central shaft on roller bearings and faces into the wind. Two traps were successfully operated continuously for four and five years, respectively, on sub-Antarctic Macquarie Island and have collected large numbers of airborne arthropods and other biological material over this period. © 2013 Antarctic Science Ltd.
- Description: C1
Morphological and physiological adaptations to waterlogging by Eucalyptus seedlings from the semi-arid Pilbara, Western Australia
- Florentine, Singarayer, Fox, John
- Authors: Florentine, Singarayer , Fox, John
- Date: 2002
- Type: Text , Journal article
- Relation: The Journal of the Royal Society of Western Australia Vol. 85, no. (2002), p. 61-70
- Full Text:
- Reviewed:
- Description: This study was undertaken to investigate the adaptation to long term waterlogging of semi-arid eucalyptus species. Long-term waterlogging of Eucalyptus victrix seedlings significantly increases seedling stem diameter. Flooding reduces photosynthesis, transpiration and stomatal conductance. Flooding does not increase shoot fresh or dry weight of 4-, 8- or 17- week old seedlings. Leaf emergence may be stimulated for flooded seedlings compared with unflooded seedlings. Root dry weight is not significantly greater for 17- week old flooded plants than 13- week old seedlings. We suggest that maintenance of a high root/shoot ratio is a drought adaptation. Furthermore, a comparative study of flood tolerance in semi-arid eucalypt species suggests that those species intolerant of flooding seldom express morphological adaptations and fail to recover from physiological damage. Flooding significantly reduced the transpiration rate and stomatal conduct of all three species. Diurnal transpiration, stomatal conductance and leaf water potential of E. terminalis and E. leucophloia were significantly different between treatment (flooding) and control seedlings.
- Description: C1
- Description: 2003000132
- Authors: Florentine, Singarayer , Fox, John
- Date: 2002
- Type: Text , Journal article
- Relation: The Journal of the Royal Society of Western Australia Vol. 85, no. (2002), p. 61-70
- Full Text:
- Reviewed:
- Description: This study was undertaken to investigate the adaptation to long term waterlogging of semi-arid eucalyptus species. Long-term waterlogging of Eucalyptus victrix seedlings significantly increases seedling stem diameter. Flooding reduces photosynthesis, transpiration and stomatal conductance. Flooding does not increase shoot fresh or dry weight of 4-, 8- or 17- week old seedlings. Leaf emergence may be stimulated for flooded seedlings compared with unflooded seedlings. Root dry weight is not significantly greater for 17- week old flooded plants than 13- week old seedlings. We suggest that maintenance of a high root/shoot ratio is a drought adaptation. Furthermore, a comparative study of flood tolerance in semi-arid eucalypt species suggests that those species intolerant of flooding seldom express morphological adaptations and fail to recover from physiological damage. Flooding significantly reduced the transpiration rate and stomatal conduct of all three species. Diurnal transpiration, stomatal conductance and leaf water potential of E. terminalis and E. leucophloia were significantly different between treatment (flooding) and control seedlings.
- Description: C1
- Description: 2003000132
- Florentine, Singarayer, Milberg, Per, Di Stefano, Julian, Westbrooke, Martin, Graz, Patrick
- Authors: Florentine, Singarayer , Milberg, Per , Di Stefano, Julian , Westbrooke, Martin , Graz, Patrick
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Arid Environments Vol. 121, no. October (2015), p. 7-14
- Full Text:
- Reviewed:
- Description: Australian arid vegetation has evolved within highly variable environments characterised by low rainfall and sporadic fire events. Episodic high rainfall events are a significant factor in plant species recruitment, but their unpredictability makes them difficult to study. We report on the response of vascular plants to a major rainfall event and flood in an arid region of south-eastern Australia. Fire that occurred two months before the flood was incorporated into the study. Paired fenced and unfenced plots were established at control locations and also in areas that had been either flooded, burnt, or flooded and burnt. Objectives were to quantify the long-term effects of fire, flood and vertebrate herbivory, and their interactions, on vegetation composition, plant life forms and species diversity. We found that relative to controls (i) there was a significant effect of flooding on vegetation composition, (ii) changes in life form abundance were driven by flooding and grazing, (iii) there was a strong positive relationship between grazer exclusion and species diversity that was maintained over time and (iv) there was little effect of fire. Understanding the long-term effects of both natural disturbances and vertebrate herbivory will benefit plant conservation in the arid zone. © 2015 Elsevier Ltd.
Association of genetic variation with systolic and diastolic blood pressure among African Americans: the Candidate Gene Association Resource study
- Fox, Ervin, Young, J. Hunter, Li, Yali, Dreisbach, Albert, Charchar, Fadi
- Authors: Fox, Ervin , Young, J. Hunter , Li, Yali , Dreisbach, Albert , Charchar, Fadi
- Date: 2011
- Type: Text , Journal article
- Relation: Human molecular genetics Vol. 20, no. 11 (June 2011), p. 2273
- Full Text:
- Reviewed:
- Description: The prevalence of hypertension in African Americans (AAs) is higher than in other US groups; yet, few have performed genome-wide association studies (GWASs) in AA. Among people of European descent, GWASs have identified genetic variants at 13 loci that are associated with blood pressure. It is unknown if these variants confer susceptibility in people of African ancestry. Here, we examined genome-wide and candidate gene associations with systolic blood pressure (SBP) and diastolic blood pressure (DBP) using the Candidate Gene Association Resource (CARe) consortium consisting of 8591 AAs. Genotypes included genome-wide single-nucleotide polymorphism (SNP) data utilizing the Affymetrix 6.0 array with imputation to 2.5 million HapMap SNPs and candidate gene SNP data utilizing a 50K cardiovascular gene-centric array (ITMAT-Broad-CARe [IBC] array). For Affymetrix data, the strongest signal for DBP was rs10474346 (P= 3.6 × 10−8) located near GPR98 and ARRDC3. For SBP, the strongest signal was rs2258119 in C21orf91 (P= 4.7 × 10−8). The top IBC association for SBP was rs2012318 (P= 6.4 × 10−6) near SLC25A42 and for DBP was rs2523586 (P= 1.3 × 10−6) near HLA-B. None of the top variants replicated in additional AA (n = 11 882) or European-American (n = 69 899) cohorts. We replicated previously reported European-American blood pressure SNPs in our AA samples (SH2B3, P= 0.009; TBX3-TBX5, P= 0.03; and CSK-ULK3, P= 0.0004). These genetic loci represent the best evidence of genetic influences on SBP and DBP in AAs to date. More broadly, this work supports that notion that blood pressure among AAs is a trait with genetic underpinnings but also with significant complexity.
- Authors: Fox, Ervin , Young, J. Hunter , Li, Yali , Dreisbach, Albert , Charchar, Fadi
- Date: 2011
- Type: Text , Journal article
- Relation: Human molecular genetics Vol. 20, no. 11 (June 2011), p. 2273
- Full Text:
- Reviewed:
- Description: The prevalence of hypertension in African Americans (AAs) is higher than in other US groups; yet, few have performed genome-wide association studies (GWASs) in AA. Among people of European descent, GWASs have identified genetic variants at 13 loci that are associated with blood pressure. It is unknown if these variants confer susceptibility in people of African ancestry. Here, we examined genome-wide and candidate gene associations with systolic blood pressure (SBP) and diastolic blood pressure (DBP) using the Candidate Gene Association Resource (CARe) consortium consisting of 8591 AAs. Genotypes included genome-wide single-nucleotide polymorphism (SNP) data utilizing the Affymetrix 6.0 array with imputation to 2.5 million HapMap SNPs and candidate gene SNP data utilizing a 50K cardiovascular gene-centric array (ITMAT-Broad-CARe [IBC] array). For Affymetrix data, the strongest signal for DBP was rs10474346 (P= 3.6 × 10−8) located near GPR98 and ARRDC3. For SBP, the strongest signal was rs2258119 in C21orf91 (P= 4.7 × 10−8). The top IBC association for SBP was rs2012318 (P= 6.4 × 10−6) near SLC25A42 and for DBP was rs2523586 (P= 1.3 × 10−6) near HLA-B. None of the top variants replicated in additional AA (n = 11 882) or European-American (n = 69 899) cohorts. We replicated previously reported European-American blood pressure SNPs in our AA samples (SH2B3, P= 0.009; TBX3-TBX5, P= 0.03; and CSK-ULK3, P= 0.0004). These genetic loci represent the best evidence of genetic influences on SBP and DBP in AAs to date. More broadly, this work supports that notion that blood pressure among AAs is a trait with genetic underpinnings but also with significant complexity.
Timing of snowmelt affects species composition via plant strategy filtering
- Good, Megan, Morgan, John, Venn, Susanna, Green, Peter
- Authors: Good, Megan , Morgan, John , Venn, Susanna , Green, Peter
- Date: 2019
- Type: Text , Journal article
- Relation: Basic and Applied Ecology Vol. 35, no. (2019), p. 54-62
- Full Text:
- Reviewed:
- Description: Plant strategy schemes aim to classify plants according to measurable traits and group species according to their shared evolutionary responses to selective pressures. In this way, it becomes possible to make meaningful comparisons among ecosystems and communities and to predict how plant communities might respond to changes in their environment. Here, we classified common alpine plants which occur in snowpatches (Early and Late snowmelt sites) and in adjacent vegetation (Snow-free sites which melt early in the growing season) using Grime's CSR plant strategy scheme. Alpine plant communities are largely driven by environmental filters associated with a relatively constant gradient of snowmelt timing. Since snow persistence influences the abiotic environment and plant assemblages alike, we hypothesised that these patterns would be reflected in community CSR scores. Weighted community CSR scores were clustered towards the stress-tolerator (S) corner of the triangular CSR space, and Snow-free communities were significantly more stress-tolerant than Early and Late snowmelt communities. This suggests that snowpatch communities are functionally distinct from surrounding vegetation when considering the major axes of plant variation identified by CSR theory. These results lend further support to the importance of the timing of snowmelt as a key filter, influencing how species and plant strategy types distribute themselves across the alpine landscape.
- Authors: Good, Megan , Morgan, John , Venn, Susanna , Green, Peter
- Date: 2019
- Type: Text , Journal article
- Relation: Basic and Applied Ecology Vol. 35, no. (2019), p. 54-62
- Full Text:
- Reviewed:
- Description: Plant strategy schemes aim to classify plants according to measurable traits and group species according to their shared evolutionary responses to selective pressures. In this way, it becomes possible to make meaningful comparisons among ecosystems and communities and to predict how plant communities might respond to changes in their environment. Here, we classified common alpine plants which occur in snowpatches (Early and Late snowmelt sites) and in adjacent vegetation (Snow-free sites which melt early in the growing season) using Grime's CSR plant strategy scheme. Alpine plant communities are largely driven by environmental filters associated with a relatively constant gradient of snowmelt timing. Since snow persistence influences the abiotic environment and plant assemblages alike, we hypothesised that these patterns would be reflected in community CSR scores. Weighted community CSR scores were clustered towards the stress-tolerator (S) corner of the triangular CSR space, and Snow-free communities were significantly more stress-tolerant than Early and Late snowmelt communities. This suggests that snowpatch communities are functionally distinct from surrounding vegetation when considering the major axes of plant variation identified by CSR theory. These results lend further support to the importance of the timing of snowmelt as a key filter, influencing how species and plant strategy types distribute themselves across the alpine landscape.
Herbicides have negligible effects on ants and springtails in an Australian wheat field
- Greenslade, Penelope, Reid, Ian, Packer, Ian
- Authors: Greenslade, Penelope , Reid, Ian , Packer, Ian
- Date: 2010
- Type: Text , Journal article
- Relation: Soil Biology and Biochemistry Vol. 42, no. 7 (2010), p. 1172-1175
- Full Text:
- Reviewed:
- Description: The effects of herbicides applied to a direct drilled and traditionally tilled wheat field on trap catches of the abundant Collembola and Formicidae were examined. Significantly higher abundances of Collembola and species richness of ants were found on the direct-drilled plots. A significant effect of the herbicides, bromoxynil (C7H3Br2NO) and hoegrass (diclofop-methyl), on the activity of two of the fourteen species of surface-dwelling Collembola was detected but no effect was observed on surface-active Formicidae. Jeannenotia stachi numbers were significantly more reduced on the direct-drilled compared to the traditionally tilled plot after herbicide treatment possibly because of higher predator abundance on the latter. In the short term, herbicides have a minimal effect on most species of surface-active arthropods although Collembola were more adversely affected than Formicidae. © 2010 Elsevier Ltd. All rights reserved.
- Authors: Greenslade, Penelope , Reid, Ian , Packer, Ian
- Date: 2010
- Type: Text , Journal article
- Relation: Soil Biology and Biochemistry Vol. 42, no. 7 (2010), p. 1172-1175
- Full Text:
- Reviewed:
- Description: The effects of herbicides applied to a direct drilled and traditionally tilled wheat field on trap catches of the abundant Collembola and Formicidae were examined. Significantly higher abundances of Collembola and species richness of ants were found on the direct-drilled plots. A significant effect of the herbicides, bromoxynil (C7H3Br2NO) and hoegrass (diclofop-methyl), on the activity of two of the fourteen species of surface-dwelling Collembola was detected but no effect was observed on surface-active Formicidae. Jeannenotia stachi numbers were significantly more reduced on the direct-drilled compared to the traditionally tilled plot after herbicide treatment possibly because of higher predator abundance on the latter. In the short term, herbicides have a minimal effect on most species of surface-active arthropods although Collembola were more adversely affected than Formicidae. © 2010 Elsevier Ltd. All rights reserved.
Blood and saliva-derived exomes from healthy Caucasian subjects do not display overt evidence of somatic mosaicism
- Hall, Nathan, Mamrot, Jared, Frampton, Chris, Read, Prue, Steele, Edward, Bischoff, Robert, Lindley, Robyn
- Authors: Hall, Nathan , Mamrot, Jared , Frampton, Chris , Read, Prue , Steele, Edward , Bischoff, Robert , Lindley, Robyn
- Date: 2020
- Type: Text , Journal article
- Relation: Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis Vol. 821, no. (2020), p.
- Full Text:
- Reviewed:
- Description: Somatic mosaicism is a normal occurrence during development in the tissues and organs. As part of establishing a “healthy population “(HP) background or base-line, we investigated whether such mosaicism can be routinely detected in the circulating DNA secured from a rigorously designed healthy human liquid biopsy clinical trial (saliva, blood). We deployed next generation (NG) whole exome sequencing (WES) at median exome coverage rates of 97.2 % (-to-30x) and 70.0 % (-to-100x). We found that somatic mosaicism is not detectable by such standard bulk WES sequencing assays in saliva and blood DNA in 24 normal healthy Caucasians of both sexes from 18 to 60 years of age. We conclude that for circulating DNA using standard WES no novel somatic mutational variants can be detected in protein-coding regions of normal healthy subjects. This implies that the extent within normal tissues of somatic mosaicism must be at a lower level, below the detection threshold, for these circulating DNA WES read depths. © 2020 The Author(s)
- Authors: Hall, Nathan , Mamrot, Jared , Frampton, Chris , Read, Prue , Steele, Edward , Bischoff, Robert , Lindley, Robyn
- Date: 2020
- Type: Text , Journal article
- Relation: Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis Vol. 821, no. (2020), p.
- Full Text:
- Reviewed:
- Description: Somatic mosaicism is a normal occurrence during development in the tissues and organs. As part of establishing a “healthy population “(HP) background or base-line, we investigated whether such mosaicism can be routinely detected in the circulating DNA secured from a rigorously designed healthy human liquid biopsy clinical trial (saliva, blood). We deployed next generation (NG) whole exome sequencing (WES) at median exome coverage rates of 97.2 % (-to-30x) and 70.0 % (-to-100x). We found that somatic mosaicism is not detectable by such standard bulk WES sequencing assays in saliva and blood DNA in 24 normal healthy Caucasians of both sexes from 18 to 60 years of age. We conclude that for circulating DNA using standard WES no novel somatic mutational variants can be detected in protein-coding regions of normal healthy subjects. This implies that the extent within normal tissues of somatic mosaicism must be at a lower level, below the detection threshold, for these circulating DNA WES read depths. © 2020 The Author(s)
Insights from long-term shorebird monitoring for tracking change in ecological character of Australasian Ramsar sites
- Hansen, Birgita, Szabo, Judit, Fuller, Richard, Clemens, Robert, Rogers, Danny, Milton, David
- Authors: Hansen, Birgita , Szabo, Judit , Fuller, Richard , Clemens, Robert , Rogers, Danny , Milton, David
- Date: 2021
- Type: Text , Journal article
- Relation: Biological Conservation Vol. 260, no. (2021), p.
- Full Text:
- Reviewed:
- Description: The Ramsar Convention is the centrepiece of international efforts for wetland conservation, aiming to maintain the ecological character of wetlands through holistic ecosystem management. Here, we review studies on shorebird populations at individual Australasian Ramsar sites and compare these against original listings under Criterion 6 to determine if there have been potential changes in ecological character. One to 12 migratory shorebird species have declined at four New Zealand and 18 Australian Ramsar sites over a 12 to 36-year period, resulting in 22 species (at 13 sites) no longer reaching Criterion 6 thresholds for Ramsar designation. In addition, 10 species at six Australian sites had exceeded the Limits of Acceptable Change. Despite these concerning results, there were remarkably few published site-based determinations of listed shorebird species' trends (and even fewer that were ≤5 years old). This is especially surprising since shorebird populations are regularly monitored at 27 out of 35 Australasian Ramsar sites (listed on the basis of one or more shorebird species). Thus, despite the volume of data available for analysis, long-term shorebird monitoring provides only limited insights about Ramsar ecological character. The value of these data would be greatly enhanced through complementary monitoring of other ecological characters at sites, particularly where shorebird populations provide early warning signs of potential deterioration. The main impediment to achieving a good understanding of how Ramsar sites are changing in Australasia appears to be a lack of analysis and centralised system for data and analytics, rather than a lack of monitoring data. © 2021 Elsevier Ltd
- Authors: Hansen, Birgita , Szabo, Judit , Fuller, Richard , Clemens, Robert , Rogers, Danny , Milton, David
- Date: 2021
- Type: Text , Journal article
- Relation: Biological Conservation Vol. 260, no. (2021), p.
- Full Text:
- Reviewed:
- Description: The Ramsar Convention is the centrepiece of international efforts for wetland conservation, aiming to maintain the ecological character of wetlands through holistic ecosystem management. Here, we review studies on shorebird populations at individual Australasian Ramsar sites and compare these against original listings under Criterion 6 to determine if there have been potential changes in ecological character. One to 12 migratory shorebird species have declined at four New Zealand and 18 Australian Ramsar sites over a 12 to 36-year period, resulting in 22 species (at 13 sites) no longer reaching Criterion 6 thresholds for Ramsar designation. In addition, 10 species at six Australian sites had exceeded the Limits of Acceptable Change. Despite these concerning results, there were remarkably few published site-based determinations of listed shorebird species' trends (and even fewer that were ≤5 years old). This is especially surprising since shorebird populations are regularly monitored at 27 out of 35 Australasian Ramsar sites (listed on the basis of one or more shorebird species). Thus, despite the volume of data available for analysis, long-term shorebird monitoring provides only limited insights about Ramsar ecological character. The value of these data would be greatly enhanced through complementary monitoring of other ecological characters at sites, particularly where shorebird populations provide early warning signs of potential deterioration. The main impediment to achieving a good understanding of how Ramsar sites are changing in Australasia appears to be a lack of analysis and centralised system for data and analytics, rather than a lack of monitoring data. © 2021 Elsevier Ltd
DRfit : A Java tool for the analysis of discrete data from multi-well plate assays
- Hofmann, Andreas, Preston, Sarah, Cross, Megan, Herath, Dilrukshi, Simon, Anne, Gasser, Robin
- Authors: Hofmann, Andreas , Preston, Sarah , Cross, Megan , Herath, Dilrukshi , Simon, Anne , Gasser, Robin
- Date: 2019
- Type: Text , Journal article
- Relation: BMC Bioinformatics Vol. 20, no. (2019), p. 1-6
- Full Text:
- Reviewed:
- Description: Background: Analyses of replicates in sets of discrete data, typically acquired in multi-well plate formats, is a recurring task in many contemporary areas in the Life Sciences. The availability of accessible cross-platform data analysis tools for such fundamental tasks in varied projects and environments is an important prerequisite to ensuring a reliable and timely turnaround as well as to provide practical analytical tools for student training. Results: We have developed an easy-to-use, interactive software tool for the analysis of multiple data sets comprising replicates of discrete bivariate data points. For each dataset, the software identifies the replicate data points from a defined matrix layout and calculates their means and standard errors. The averaged values are then automatically fitted using either a linear or a logistic dose response function. Conclusions: DRfit is a practical and convenient tool for the analysis of one or multiple sets of discrete data points acquired as replicates from multi-well plate assays. The design of the graphical user interface and the built-in analysis features make it a flexible and useful tool for a wide range of different assays.
- Authors: Hofmann, Andreas , Preston, Sarah , Cross, Megan , Herath, Dilrukshi , Simon, Anne , Gasser, Robin
- Date: 2019
- Type: Text , Journal article
- Relation: BMC Bioinformatics Vol. 20, no. (2019), p. 1-6
- Full Text:
- Reviewed:
- Description: Background: Analyses of replicates in sets of discrete data, typically acquired in multi-well plate formats, is a recurring task in many contemporary areas in the Life Sciences. The availability of accessible cross-platform data analysis tools for such fundamental tasks in varied projects and environments is an important prerequisite to ensuring a reliable and timely turnaround as well as to provide practical analytical tools for student training. Results: We have developed an easy-to-use, interactive software tool for the analysis of multiple data sets comprising replicates of discrete bivariate data points. For each dataset, the software identifies the replicate data points from a defined matrix layout and calculates their means and standard errors. The averaged values are then automatically fitted using either a linear or a logistic dose response function. Conclusions: DRfit is a practical and convenient tool for the analysis of one or multiple sets of discrete data points acquired as replicates from multi-well plate assays. The design of the graphical user interface and the built-in analysis features make it a flexible and useful tool for a wide range of different assays.