Adding thermal information to multisensory input in simulated environments
- Authors: Van Doorn, George , Richardson, Barry , Symmons, Mark , Wells, Jonathan
- Date: 2009
- Type: Text , Journal article
- Relation: International Journal of Intelligent Defence Support Systems Vol. 2, no. 4 (2009 2009), p. 350-362
- Full Text: false
- Reviewed:
- Description: Although simulated environments are improved by adding sensory information, temperature is one input that has rarely featured in them. Here we report findings from experiments that examine the efficacy of adding temperature information to the multimodal complex known to be of benefit in simulations. In the first experiment, Peltier tiles added thermal information to the kinesthetic feedback given by a hand-worn exoskeletal device and this increased ratings for 'presence' during interactions with simulated objects. In an experiment in which exploratory movements across surfaces of differing temperatures were either active or passive-guided, the degree of 'coldness' felt at the fingertip was reported as less intense when movement was active, suggesting that intentionality of movement plays a role in the attenuation of the thermal stimulus. Other work reported here suggests that the perception of temperature is not influenced by a simultaneously presented colour. For example, the perception of coldness is not enhanced when it is processed in conjunction with a blue colour. We discuss the potential value of thermal information within the context of the hypothesis that presence in simulated environments is enhanced by multisensory inputs that include redundant information.
Air temperature and the incidence of fall-related hip fracture hospitalisations in older people
- Authors: Turner, R. M. , Hayen, Andrew , Dunsmuir, William , Finch, Caroline
- Date: 2011
- Type: Text , Journal article
- Relation: Osteoporosis International Vol. 22, no. 4 (2011), p. 1183-1189
- Relation: http://purl.org/au-research/grants/nhmrc/565900
- Full Text:
- Reviewed:
- Description: Observation-driven Poisson regression models were used to investigate mean daily air temperature and fall-related hip fracture hospitalisations. After adjustment for season, day-of-week effects, long-term trend and autocorrelation, hip fracture rates are higher in both males and females aged 75+ years when there is a lower air temperature. This study investigated whether there was an association between fall-related hip fracture hospitalisations and air temperature at a day-to-day level, after accounting for seasonal trend and autocorrelation. Observation-driven Poisson regression models were used to investigate mean daily air temperature and fall-related hip fracture hospitalisations for the period 1 July 1998 to 31 December 2004, inclusive, in the Sydney region of New South Wales, Australia, which has a population of 4 million people. Lower daily air temperature was significantly associated with higher fall-related hip fracture hospitalisations in 75+-year-olds: men aged 75-84 years, rate ratio (RR) for a 1A degrees C increase in temperature of 0.98 with 95% confidence interval (0.96, 0.99), men 85+ years RR = 0.98 (0.96, 1.00), women 75-84 years RR = 0.99 (0.98, 1.00), women 85+ years RR = 0.98 (0.97, 0.99). Moreover, there were fewer hospitalisations on weekends compared to weekdays ranging from RR = 0.81 (0.73, 0.90) in women aged 65-74 years to RR = 0.89 (0.80, 0.98) in men aged 85+ years. After adjustment for season, day-of-week effects, long-term trend and autocorrelation, fall-related hip fracture hospitalisation rates are higher in both males and females aged 75+ years when there is a lower air temperature.
Assuring crop protection in the face of climate change through an understanding of herbicide metabolisms and enhanced weed control strategies
- Authors: Jabran, Khawar , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2020
- Type: Text , Book chapter
- Relation: Crop protection under changing climate Chapter 2 p. 17-56
- Full Text: false
- Reviewed:
- Description: The prevention and management of weeds have been difficult throughout the history of food production. We are now entering into a new era where new challenges are arising more rapidly due in part to the rapid population growth, which places an unprecedented demand upon both natural and agricultural ecosystems to fulfil food, fibre, and feed for at least another two billion people by 2050. Climatic change is associated with a higher frequency of extreme weather events, and it is generally agreed that this will have a drastic impact on ecosystem productivity and biodiversity. The present world atmospheric temperature has increased by 1.0 °C since 1900 with half of this rise coming in the past 30 years. Crop production is directly affected by the direct effects of climate change (temperature and water stress) and indirect effects of increased competition from weeds and other pest species. In a field situation, crop plants are inevitably surrounded by an assemblage of C3 and C4 plants, and a considerable variation in the growth response of weeds to climate change have been reported. In this chapter, we present an overview of the impact of temperature rise, carbon dioxide increase, and changed rainfall patterns on weed composition, distribution, abundance, and our current approaches to weed management. There is a high risk that some weed species will shift their range with the change in temperature and precipitation patterns. The efficacy of chemical weed control depends on the environmental conditions before, during and after the herbicide application. The changes in physiology, morphology, and anatomy of plants will result in altered weed growth, crop-weed competition, and herbicide efficacy under elevated temperature and/or carbon dioxide. Global warming may increase the risk of evolution of nontarget site resistance mechanisms against herbicides in the weed plants and thus decrease herbicide efficacy. The anticipated actions in these areas are also discussed in the end which may enhance our understanding of the impact of climate change on the practice and future of weed management and crop production.
Effect of selected environmental factors on the seed germination of the invasive species Polygala myrtifolia (Polygalaceae) in Australia
- Authors: Roberts, Natalie , Moloney, Katrina , Monie, Kristin , Florentine, Singarayer
- Date: 2023
- Type: Text , Journal article
- Relation: Australian Journal of Botany Vol. 71, no. 6 (2023), p. 286-295
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- Description: Context. Polygala myrtifolia L. has become a significant environmental weed in Australia, where it has invaded coastal ecosystems in temperate regions and there is a high risk of extensive further spread. Knowledge of seed-germination behaviour is essential to understand the potential future impact of this species. Aims. We investigated the effects of selected environmental factors and dormancy on P. myrtifolia seed germination and emergence to improve management strategies. Methods. Seeds were exposed to light, temperature, pH, salinity, osmotic potential and burial depth treatments to assess germination responses, dormancy and viability. Key results. Non-dormant seeds readily germinated to high percentages (93.0–95.0%) under specific day–night temperatures of 25°C–15°C regardless of light conditions and across all soil pH (75.0–100.0%). Salinities were tolerated up to 100 mM NaCl (70.0% germination) before sharply declining. Germination reduced from 98.3% to 40.0% at osmotic potentials of
Effect of temperature and plasticizer molecular size on moisture diffusion of plasticized-starch biopolymer
- Authors: Chaudhary, Deeptangshu , Adhikari, Benu
- Date: 2010
- Type: Text , Journal article
- Relation: Starch Vol. 62, no. 7 (2010), p. 364-372
- Full Text: false
- Reviewed:
- Description: Using starch pellets as precursor for traditional edible food packaging for making thermoformed products is an excellent idea. We report here the complex water migration behaviour of starch pellets as influenced by plasticizer type and concentration at various temperatures. The evidence for synergistic interaction between plasticizers and water within starch is shown by the reduced effective moisture diffusivities and moisture migration fluxes at different overall plasticizer concentrations. In addition, the effective moisture diffusivities showed stronger dependence on moisture concentration and the plasticizer molecular weight even though the moisture flux was comparable. The drying process was characterized by two effective diffusion coefficients (D 1, D2) and interestingly, the coefficients were an order of significance apart. Peleg model was investigated for predicting the drying behaviour and it is shown that the Peleg constants k1 and k 2 increase with temperature. k2, a material structure parameter, showed variation by addition of plasticizers, indicating that plasticizers were able to modify fundamental structure; and xylitol showed greater average k2 values than glycerol. Further, k1, a moisture diffusivity parameter, was affected by temperature and Arrhenius relationship was used for activation energy values for k1 of plasticized starch. It is shown that compared to starch and water, presence of plasticizer had many order of significance higher k1 and confirm the hypothesis that plasticizers can 'lock' in water within the new structure. Xylitol showed better stability in controlling moisture diffusivities and migration fluxes as compared to glycerol. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.
- Description: 2003008252
Effects of ultrasound on glass transition temperature of freeze-dried pear (Pyrus pyrifolia) using DMA thermal analysis
- Authors: Islam, Nahidul , Zhang, Min , Liu, Huihua , Xinfeng, Cheng
- Date: 2015
- Type: Text , Journal article
- Relation: Food and Bioproducts Processing Vol. 94, no. (2015), p. 229-238
- Full Text: false
- Reviewed:
- Description: The effect of ultrasound pretreatment at various power (360 W, 600 W and 960 W, frequency 20 kHz) on the glass transition temperature of freeze dried pear (Pyrus pyrifolia) has been studied. DMA temperature plots were divided into four sections (A - glassy region, B - transition region, C - Rubbery plateau region and D - terminal region) with the aim to analyze their properties changed with sonication. Under the same freeze drying condition, with the increase in ultrasonic power, dried pear showed higher glass transition in terms of storage modulus, loss modulus and loss tangent peak. Also a decrease in a
Environmental factors affecting the germination and emergence of white horehound (Marrubium vulgare L.) : A weed of arid-zone areas
- Authors: Javaid, Muhammad , Florentine, Singarayer , Ali, Hafiz , Chauhan, Bhagirath
- Date: 2018
- Type: Text , Journal article
- Relation: Rangeland Journal Vol. 40, no. 1 (2018), p. 47-54
- Full Text: false
- Reviewed:
- Description: White horehound (Marrubium vulgare L.), is a troublesome weed of arid zones, particularly in cropping and grazing areas. Understanding the seed ecology of white horehound is relevant to its management. The present study investigated the effects of temperature, light, osmotic potential, salinity, pH, and seeding depth on seed germination and seedling emergence of white horehound. Seeds germinated over a wide range of temperatures, with highest germination (100%) occurring at 25/20°C in either 12-h alternating light/dark or complete darkness. Germination decreased from 92% to 10% as the osmotic potential decreased from 0 to minus 0.6MPa and germination was completely inhibited at minus 0.8MPa. Increasing concentration of sodium chloride (salinity) from 50 to 150mM reduced germination from 68% to 11% but was completely inhibited at 200mM. Germination was not limited by variation of pH in solutions of pH 5 to pH 10. Maximum germination (99%) occurred at pH 7, but slightly decreased (90%) in acidic or alkaline media. Surface located seeds were highly germinable (87%) where seedling emergence significantly declined as seeding depth increased from 0.5 to 3cm. Nil seedling emergence was occurred at 4cm burial depth. Light significantly affected germination, time to 50% germination, mean germination time and germination index. Increasing osmotic and salinity stress both significantly increased the time to start germination, time to 50% germination, mean germination time, but decreased germination index. Burial depth adversely affected seedling emergence with surface located seedlings emerging earlier (4.2 days) compared with 20 days for seeds buried at 3cm. Results suggest that effective management of white horehound should consider targeting surface located seeds in combination with tools that induce minimal soil disturbance, particularly in relatively non-saline environments.
Factors affecting seed germination of feather fingergrass (Chloris virgata)
- Authors: Fernando, Nimesha , Humphries, Talia , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2016
- Type: Text , Journal article
- Relation: Weed Science Vol. 64, no. 4 (2016), p. 605-612
- Full Text: false
- Reviewed:
- Description: Laboratory experiments were carried out to determine the effect of several environmental factors on seed germination of feather fingergrass, one of the most significant emerging weeds in warm regions of the world. Seed germination occurred over a broad range of temperatures (17/7, 25/10, and 30/20 C), but germination being highest at alternating temperatures of 30/20 C under both 12 h light/12 h dark and 24 h dark conditions. Although seed germination was favored by light, some seeds were capable of germinating in the dark. Increasing salt stress decreased seed germination until complete inhibition was reached at 250-mM sodium chloride. Germination decreased from 64 to 0.7% as osmotic potential decreased from 0 to -0.4 MPa, and was completely inhibited at -0.6 MPa. Higher seed germination (>73%) was observed in the range of pH 6.4 to 8 than the other tested pH levels. Heat shock had a significant effect on seed germination. Germination of seeds placed at 130 C for 5 min was completely inhibited for both dry and presoaked seeds. The results of this study will help to develop protocols for managing feather fingergrass, and to thus avoid its establishment as a troublesome weed in economically important cropping regions.
Factors effecting the germination and emergence of a rangeland weed European heliotrope (Heliotropium europaeum L.)
- Authors: Humphries, Talia , Graz, Friedrich , Florentine, Singarayer
- Date: 2018
- Type: Text , Journal article
- Relation: Rangeland Journal Vol. 40, no. 6 (2018), p. 583-590
- Full Text: false
- Reviewed:
- Description: European heliotrope (Heliotropium europaeum L.) is an important weed in semiarid and arid Australia, due to its toxicity to livestock and its ability to out-compete crops for water and soil nutrients. It is an ephemeral species populations appear in high densities when conditions are favourable, but seeds remain dormant in the soil seedbank for extended periods of time. This study aimed to identify environmental factors that promoted the germination of this weed and factors that de-vitalise seeds. Seeds were collected from the Australian semiarid zone, at Nanya Research Station, New South Wales. The effects on seed germination and seedling emergence of H. europaeum of alternating temperature, photoperiod, drought, salinity, pH range, heat shock combined with smoke exposure, and burial depth were investigated. The highest germination rate was observed under the highest temperature regime, 30/20°C, under a photoperiod of 12 h light and 12 h dark. The weed germinated under moderate osmotic stress, but the highest germination occurred in the control treatment (no osmotic stress). The effect of salinity and pH on percentage germination was not significant. The effect of the heat shock and smoke treatment significantly reduced seed germination, with germination inhibited when seeds were exposed to 100°C for 3 min. Burial depth had a significant effect on seedling emergence, with a burial depth of 0.5 cm reducing the germination by
Germination ecology of hairy fleabane (Conyza bonariensis) and its implications for weed management
- Authors: Loura, Deepak , Sahil , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2020
- Type: Text , Journal article
- Relation: Weed Science Vol. 68, no. 4 (Jul 2020), p. 411-417
- Full Text: false
- Reviewed:
- Description: Hairy fleabane [Conyza bonariensis(L.) Cronquist] is a problematic weed in Australian no-till cropping systems. Consequently, a study was conducted to examine the effect of temperature, light, salt stress, osmotic stress, burial depth, and sorghum crop residue on germination and emergence in two populations (C and W: collected from chick pea [Cicer arietinumL.] and wheat [Triticum aestivumL.] fields, respectively) ofC. bonariensis. Both populations were able to germinate over a wide range of alternating day/night temperatures (15/5 to 35/25 C); however, the C population had optimum (and similar) germination over the range of 20/10 and 30/20 C, while the W population showed maximum germination at 25/15 C. A negative relationship was observed between osmotic potential and germination, with 31% and 14% germination of the C and W populations at -0.6 MPa, respectively. These observations suggest that population C was more tolerant to higher osmotic potentials than population W. Seeds of both populations germinated when exposed to a wide range of sodium chloride levels (NaCl, 0 to 200 mM); however, beyond 200 mM NaCl, no germination was observed in either population. Maximum germination of the C (70%) and W (41%) populations was observed on the soil surface with no emergence from a burial depth of 1 cm. The application of sorghum residue at an amount of 6,000 kg ha(-1)reduced emergence of the C and W populations by 55% and 58%, respectively, compared with the no-residue treatment. Knowledge gained from this study suggests that the following strategies could be used for more efficacious management ofC. bonariensis: (1) a shallow-tillage operation to bury weed seeds in conventional tillage systems, and (2) retention of sorghum residue on the soil surface in no-till systems.
Illusory upward self-motion results in a decrease in perceived room temperature
- Authors: Seno, Takeharu , Van Doorn, George
- Date: 2013
- Type: Text , Journal article
- Relation: Psychology (Irvine) Vol. 4, no. 11 (2013), p. 823-826
- Full Text:
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- Description: Purpose: Stationary observers often experience illusory self-motion (vection) when they are exposed to large patterns of optic flow. The effect of different temperatures on the strength of vection was investigated. Method: Eleven participants were exposed to visual stimuli that induced illusory motion (up, down) in three room temperatures (26°C - 27°C, 21°C - 22°C, 5°C - 6°C). Participants rated (a) the vection magnitude, and (b) the room temperature (twice; before and after vection). Results: Upward vection was rated as stronger than downward vection in the 26°C - 27°C temperature. In addition, after experiencing upward and downward vection, subjective ratings of room temperature decreased and increased, respectively, when the room temperature was 26°C - 27°C. This effect was not observed when the room was 5°C - 6°C. Conclusion: These results suggest that a cross modal association exists between the direction “up” and 26°C - 27°C temperatures.
Impact of load ramping on power transformer dissolved gas analysis
- Authors: Cui, Huize , Yang, Liuging , Li, Shengtao , Qu, Guanghao , Wang, Hao , Abu-Siada, Ahmed , Islam, Syed
- Date: 2019
- Type: Text , Journal article
- Relation: IEEE Access Vol. 7, no. (2019), p. 170343-170351
- Full Text:
- Reviewed:
- Description: Dissolved gas in oil analysis (DGA) is one of the most reliable condition monitoring techniques, which is currently used by the industry to detect incipient faults within the power transformers. While the technique is well matured since the development of various offline and online measurement techniques along with various interpretation methods, no much attention was given so far to the oil sampling time and its correlation with the transformer loading. A power transformer loading is subject to continuous daily and seasonal variations, which is expected to increase with the increased penetration level of renewable energy sources of intermittent characteristics, such as photovoltaic (PV) and wind energy into the current electricity grids. Generating unit transformers also undergoes similar loading variations to follow the demand, particularly in the new electricity market. As such, the insulation system within the power transformers is expected to exhibit operating temperature variations due to the continuous ramping up and down of the generation and load. If the oil is sampled for the DGA measurement during such ramping cycles, results will not be accurate, and a fault may be reported due to a gas evolution resulting from such temporarily loading variation. This paper is aimed at correlating the generation and load ramping with the DGA measurements through extensive experimental analyses. The results reveal a strong correlation between the sampling time and the generation/load ramping. The experimental results show the effect of load variations on the gas generation and demonstrate the vulnerabilities of misinterpretation of transformer faults resulting from temporary gas evolution. To achieve accurate DGA, transformer loading profile during oil sampling for the DGA measurement should be available. Based on the initial investigation in this paper, the more accurate DGA results can be achieved after a ramping down cycle of the load. This sampling time could be defined as an optimum oil sampling time for transformer DGA.
Influence of selected environmental factors on seed germination and seedling survival of the arid zone invasive species tobacco bush (Nicotiana glauca R. Graham)
- Authors: Florentine, Singarayer , Weller, Sandra , Graz, Patrick , Westbrooke, Martin , Florentine, Arunthathy , Javaid, Muhammad , Fernando, Nimesha , Chauhan, Bhagirath , Dowling, Kim
- Date: 2016
- Type: Text , Journal article
- Relation: Rangeland Journal Vol. 38, no. 4 (2016), p. 417-425
- Full Text: false
- Reviewed:
- Description: Tobacco bush (Nicotiana glauca R. Graham) is an aggressive invading species, which is active after disturbances such as high rainfall events and flooding. Past studies have focussed on population dynamics and allelopathic effects associated with the species, but little is known about its seed ecology. To address this dearth of information, this study aimed to investigate: (i) the effect of various stress factors (temperature, light, osmotic potential, salt stress, heat-shock, a combination of heat-shock and smoke, pH buffer, and burial depth of seed) on seed germination and seedling emergence, and (ii) factors affecting the fate of seedlings. The results show that N. glauca was able to germinate over a broad range of temperatures with highest seed germination occurring at 30/20°C with 12h of light and 12h of dark conditions. Seed germination was greatest (89%) when seeds were placed on the soil surface and emergence decreased considerably as planting depth increased from 0.5 to 1.5cm. Water stress greatly reduced seed germination (58% germination at osmotic potentials below -0.2 MPa) and germination was completely inhibited at water potentials of -0.4 to -0.6 MPa. Although increasing salinity reduced the seed germination of this invasive species, N. glauca seed was able to germinate in both alkaline (81% at pH 10) and acidic (80% at pH 4) conditions. The trial on the effect of seed age and field seed burial on seed germination showed a slight decline in seed germination after 120 days of burial compared with non-buried seeds. Further, the combined effect of heat-shock and smoke effectively inhibited the germination of N. glauca seeds; however, our study shows that seedlings of N. glauca can withstand heat-shock of up to 130°C. Studies such as this will assist in the development of control strategies to prevent the spread of this invasive species into arid landscapes. © 2016 Australian Rangeland Society.
Influence of various environmental factors on seed germination and seedling emergence of a noxious environmental weed: Green Galenia (Galenia pubescens)
- Authors: Mahmood, Ako , Florentine, Singarayer , Chauhan, Bhagirath , McLaren, David , Palmer, Grant , Wright, Wendy
- Date: 2016
- Type: Text , Journal article
- Relation: Weed Science Vol. 64, no. 3 (2016), p. 486-494
- Full Text: false
- Reviewed:
- Description: Green galenia is a South African woody prostrate perennial that was first recorded in Australia in the early 1900s and has since become a serious threat to indigenous temperate grasslands and surrounding agricultural areas. Laboratory and field based experiments were conducted to examine the effect of environmental factors on the germination and viability of green galenia seed. It was shown that green galenia was able to germinate over a broad range of temperatures, but short bursts (5 min) of high temperatures (80 C to 120 C replicating possible exposures to a fire) reduced seed germination. Seed germination was positively favored by light, declined rapidly in darkness, and decreased by >80% at a depth of only 0.5 cm in soil. Water stress greatly reduced seed germination (45% germination at osmotic potentials below -0.2 MPa). Germination was completely inhibited at water potentials of -0.4 to -1.0 MPa. This species is moderately tolerant to salinity, with over 50% of seeds germinating at low levels of salinity (60 mM NaCl), and moderate germination (49%) occurring at 120 mM NaCl, it can germinate well in both alkaline (pH 10-83%) and acidic (pH 4-80%) conditions. The results of this study have contributed to our understanding of the germination and emergence of green galenia, and this will assist in developing tools and strategies for the long term management of this noxious weed in Victoria and other parts of Australia. Nomenclature: Green galenia, Galenia pubescens (Eckl. & Zeyh.) Druce.
Late Quaternary paleolimnology of Onepoto maar, Auckland, New Zealand : Implications for the drivers of regional paleoclimate
- Authors: Augustinus, Paul , Cochran, Ursula , Kattel, Giri , D'Costa, Donna , Shane, Phil
- Date: 2012
- Type: Text , Journal article
- Relation: Quaternary International Vol. 253, no. (2012), p. 18-31
- Full Text: false
- Reviewed:
- Description: A high-resolution record of lacustrine environments spanning ca. 30-9calkaBP was obtained from Onepoto maar, northern North Island, New Zealand. The multi-proxy record of environmental change is constrained by tephrochronology and AMS 14C ages and provides evidence for episodes of rapid environmental change during the Last Glacial Coldest Period (LGCP: 28.5-18calkaBP) and Late Glacial-Interglacial Transition (LGIT) from northern New Zealand. The Onepoto pollen record indicates that the LGCP was cold, dry and windy in the Auckland region with vegetation dominated by herbs and grasses in a beech forest mosaic. At the same time the diatom record indicates oligotrophic conditions with low lakes levels and turbulence whilst cladocerans indicate low water temperatures. The inference of cold, dry and windy conditions during the LGCP is supported by geochemical evidence for increased sediment influx, charcoal and CO 2 limiting conditions for terrestrial macrophytes. Rapid climate amelioration and forest expansion after ca. 18calkaBP corresponds with reduced sediment influx, diatom and cladoceran-inferred higher lake levels indicating increasing moisture availability and temperature. Diatom flora indicates that an oligotrophic, circumneutral lake was becoming established during the LGIT but conditions were still variable. Between ca. 13.8 and 12.5calkaBP two brief drier and possibly cooler episodes are apparent (ca. 13.8-13.2 and 13-12.5calkaBP) followed by a warm phase combined with generally stable high lake levels between ca. 12.5 and 10.5calkaBP. Subsequently the lake water chemistry became more alkaline and eutrophic, possibly because sea level had risen high enough by this time to influence ground water chemistry. © 2011 Elsevier Ltd and INQUA.
Managing consequences of climate-driven species redistribution requires integration of ecology, conservation and social science
- Authors: Bonebrake, Timothy , Brown, Christopher , Bell, Johann , Blanchard, Julia , Chauvenet, Alienor , Champion, Curtis , Chen, I-Ching , Clark, Timothy , Colwell, Robert , Danielsen, Finn , Dell, Anthony , Donelson, Jennifer , Evengård, Birgitta , Ferrier, Simon , Frusher, Stewart , Garcia, Raquel , Griffis, Roger , Hobday, Alistair , Jarzyna, Marta , Lee, Emma , Lenoir, Jonathan , Linnetved, Hlif , Martin, Victoria , McCormack, Phillipa , McDonald, Jan , McDonald-Madden, Eve , Mitchell, Nicola , Mustonen, Tero , Pandolfi, John , Pettorelli, Nathalie
- Date: 2018
- Type: Text , Journal article
- Relation: Biological Reviews Vol. 93, no. 1 (2018), p. 284-305
- Full Text:
- Reviewed:
- Description: Climate change is driving a pervasive global redistribution of the planet's species. Species redistribution poses new questions for the study of ecosystems, conservation science and human societies that require a coordinated and integrated approach. Here we review recent progress, key gaps and strategic directions in this nascent research area, emphasising emerging themes in species redistribution biology, the importance of understanding underlying drivers and the need to anticipate novel outcomes of changes in species ranges. We highlight that species redistribution has manifest implications across multiple temporal and spatial scales and from genes to ecosystems. Understanding range shifts from ecological, physiological, genetic and biogeographical perspectives is essential for informing changing paradigms in conservation science and for designing conservation strategies that incorporate changing population connectivity and advance adaptation to climate change. Species redistributions present challenges for human well-being, environmental management and sustainable development. By synthesising recent approaches, theories and tools, our review establishes an interdisciplinary foundation for the development of future research on species redistribution. Specifically, we demonstrate how ecological, conservation and social research on species redistribution can best be achieved by working across disciplinary boundaries to develop and implement solutions to climate change challenges. Future studies should therefore integrate existing and complementary scientific frameworks while incorporating social science and human-centred approaches. Finally, we emphasise that the best science will not be useful unless more scientists engage with managers, policy makers and the public to develop responsible and socially acceptable options for the global challenges arising from species redistributions. © 2017 Cambridge Philosophical Society **Please note that there are multiple authors for this article therefore only the name of the first 30 including the now Federation University Australia affiliate “Emma Lee” is provided in this record**
Seed germination response of a potential rangeland weed Psilocaulon granulicaule to selected environmental conditions
- Authors: Ranaweera, Rekha , Weller, Sandra , Florentine, Singarayer
- Date: 2020
- Type: Text , Journal article
- Relation: Australian Journal of Botany Vol. 68, no. 5 (2020), p. 363-368
- Full Text: false
- Reviewed:
- Description: Studies show that just over 620 non-native naturalised plant species have been recorded within the Australian rangelands, some of which have a capacity to cause significant impacts on rangeland flora and grazing activity. Although Psilocaulon granulicaule (Haw.), Schwantes is listed as a highly invasive environmental weed species, there has been no previous research into its seed ecology. Therefore, this study was conducted to investigate the effects of temperature, light, pH, water stress, heat-shock, and salinity on the germination of P. granulicaule. In this study, four temperature regimes covering four different day and night temperature variations (17-7°C, 25-15°C, 30-25°C and 40-30°C) and two light regimes (12-h light-12-h dark, 24-h dark) were investigated. The effects of pH, water stress, heat-shock and salinity were investigated, using pH buffers, polyethylene glycol solutions, three heat shock events under four temperatures and a range of NaCl solutions. These tests were conducted under the identified optimum temperature range (25/15°C) and light regime for seed germination. The results showed that both temperature and photoperiod significantly influenced the germination rate, with 94.2% germination in the 25-15°C range under a 12-h light-12-h dark regime. Higher temperatures (30-40°C) reduced seed germination to <58% germination in both light regimes (57.5%, 12-h light-12-h dark; 54.17%, 24-h dark). The highest germination rates were observed in low pH solutions, high moisture levels, low heat-shocks and low salinity. The study showed that this species is sensitive to environmental factors such as temperature, light, pH, moisture, heat shock and salinity, suggesting that these factors can be used as critical indicators to guide effective management practices to address this weed problem. Given that seeds are sensitive to radiant heat, burning could be used as a tool to effectively manage this species. © 2020 CSIRO.
Statistical calibration of long-term reanalysis data for australian fire weather conditions
- Authors: Biswas, Soubhik , Chand, Savin , Dowdy, Andrew , Wright, Wendy , Foale, Cameron , Zhao, Xiaohui , Deo, A
- Date: 2022
- Type: Text , Journal article
- Relation: Journal of Applied Meteorology and Climatology Vol. 61, no. 6 (2022), p. 729-758
- Full Text: false
- Reviewed:
- Description: Reconstructed weather datasets, such as reanalyses based on model output with data assimilation, often show systematic biases in magnitude when compared with observations. Postprocessing approaches can help adjust the distribution so that the reconstructed data resemble the observed data as closely as possible. In this study, we have compared various statistical bias-correction approaches based on quantile–quantile matching to correct the data from the Twentieth Century Reanalysis, version 2c (20CRv2c), with observation-based data. Methods included in the comparison utilize a suite of different approaches: a linear model, a median-based approach, a nonparametric linear method, a spline-based method, and approaches that are based on the lognormal and Weibull distributions. These methods were applied to daily data in the Australian region for rainfall, maximum temperature, relative humidity, and wind speed. Note that these are the variables required to compute the forest fire danger index (FFDI), widely used in Australia to examine dangerous fire weather conditions. We have compared the relative errors and performances of each method across various locations in Australia and applied the approach with the lowest mean-absolute error across multiple variables to produce a reliable long-term biascorrected FFDI dataset across Australia. The spline-based data correction was found to have some benefits relative to the other methods in better representing the mean FFDI values and the extremes from the observed records for many of the cases examined here. It is intended that this statistical bias-correction approach applied to long-term reanalysis data will help enable new insight on climatological variations in hazardous phenomena, including dangerous wildfires in Australia extending over the past century. © 2022 American Meteorological Society.
Stochastic modeling of the output power of photovoltaic generators in various weather conditions
- Authors: Batool, Munira , Islam, Syed , Shahnia, Farhad
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 Australasian Universities Power Engineering Conference, AUPEC 2016; Brisbane, Australia; 25th-28th September 2016 p. 1-5
- Full Text:
- Reviewed:
- Description: The intermittency of solar-powered energy sources prompt the uncertainty of load management. The influence of shading (whatever the reason may be) directly diminishes the feasible output power of the photovoltaic (PV) generators. The major causes of shading are the weather condition changes like the clouds, storms, and rains. Thereby, the dispatchable power for a distinct weather condition at an explicit time frame needs to be quantified. The stochastic modeling of a practical PV system has been performed in this paper. A step-by-step MATLAB-based algorithm is developed for tracking of dispatchable power limit using the Monte Carlo Principle. The proposed algorithm describes the weather condition as a function of cloud presence. The prescribed characteristics consist of the solar irradiance and the ambient temperature. The impact of weather changes on the output power of a PV system is evaluated by this algorithm. The results of this research are concluded by realistic data analysis taken from the Australian bureau of meteorology.
The effects of proteins and low molecular weight surfactants on spray drying of model sugar-rich foods: Powder production and characterisation
- Authors: Jayasundera, Mithila , Adhikari, Benu , Adhikari, Raju , Aldred, Peter
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 104, no. 2 (2011), p. 259-271
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- Description: The effects of proteins and low molecular weight surfactants (LMS) on spray drying and powder characteristics of model sugar-rich foods have been studied. Fructose and sucrose were selected as model sugar-rich foods and sodium caseinate (NaCas) was selected as a model protein. Sodium stearoyl lactylate (SSL) and Polysorbate 80 (Tween-80) were chosen as model ionic and non-ionic low molecular weight surfactants. The feed solutions for spray drying had 25% solid concentration in all. To achieve identical powder recoveries of the order of 80% much higher NaCas:fructose ratio (30:70) was required compared to NaCas:sucrose ratio (0.5:99.5) which corresponded to 7.89% and 0.13% of sodium caseinate (initial bulk concentration), respectively. There was no change in powder recovery when the SSL concentration was increased from 0.01% to 0.05% in fructose-NaCas-SSL solution and also addition of 0.01% Tween-80 into fructose-NaCas solution did not affect the powder recovery (76.7 ± 2.3%), however, it was slightly affected with the increase of Tween-80 to 0.05% (69.0 ± 1.9%). At NaCas concentration above critical micelle concentration of NaCas (3% w/w), the presence of up to 0.05% low molecular weight surfactants had either no effect or minimal effect on the surface coverage of the droplets/particles and also on the powder recovery depending on the nature of the low molecular weight surfactants. The surface protein coverage and the recovery of the powder in sucrose-protein systems were very sensitive in the presence of low molecular weight surfactants due to being below the critical micelle concentration of NaCas. SSL displaced 2.0% and 29.3% of proteins from the droplet surface of sucrose-NaCas-SSL, respectively, when its concentration was varied from 0.01% to 0.05% thereby reducing the powder recovery from 75.5% to 30%. The addition of 0.01% Tween-80 in sucrose-NaCas solution resulted in a 48.2 ± 1.5% reduction in powder recovery and at 0.05% concentration, it displaced a substantial amount of NaCas from the droplet surface and no powder was recovered. These phenomena are explained on the basis of surface-glass transition temperature, dynamic surface tension, nature of surfactants and glass transition temperature of sugars used. X-ray diffraction and scanning electron microscopy results showed that the powders of sucrose-NaCas, sucrose-NaCas with 0.01% SSL and all powders of fructose were amorphous. © 2010 Elsevier Ltd. All rights reserved.