Repeated long-term sub-concussion impacts induce motor dysfunction in rats : a potential rodent model
- Authors: Lavender, Andrew , Rawlings, Samuel , Warnock, Andrew , McGonigle, Terry , Hiles-Murison, Bailey , Nesbit, Michael , Lam, Virginie , Hackett, Mark , Fitzgerald, Melinda , Takechi, Ryusuke
- Date: 2020
- Type: Text , Journal article
- Relation: Frontiers in Neurology Vol. 11, no. (2020), p.
- Full Text:
- Reviewed:
- Description: Whilst detrimental effects of repeated sub-concussive impacts on neurophysiological and behavioral function are increasingly reported, the underlying mechanisms are largely unknown. Here, we report that repeated sub-concussion with a light weight drop (25 g) in wild-type PVG rats for 2 weeks does not induce detectable neuromotor dysfunction assessed by beamwalk and rotarod tests. However, after 12 weeks of repeated sub-concussion, the rats exhibited moderate neuromotor dysfunction. This is the first study to demonstrate development of neuromotor dysfunction following multiple long-term sub-concussive impacts in rats. The outcomes may offer significant opportunity for future studies to understand the mechanisms of sub-concussion-induced neuropsychological changes. © Copyright © 2020 Lavender, Rawlings, Warnock, McGonigle, Hiles-Murison, Nesbit, Lam, Hackett, Fitzgerald and Takechi.
Short-term gain and long-term pain: Lessons learnt from the control of Lachnagrostis filiformis (fairy grass) in Victoria, Australia
- Authors: Warnock, Andrew , Florentine, Singarayer , Graz, Patrick , Westbrooke, Martin
- Date: 2012
- Type: Text , Journal article
- Relation: Weed Biology and Management Vol. 12, no. 4 (December 2012), p. 156-167
- Full Text: false
- Reviewed:
- Description: The indigenous Lachnagrostis filiformis colonized extensive areas of dry lake beds in Victoria, Australia, during the drought from 1997 to 2009. Large numbers of the plants' detached seed heads disperse in the wind, lodging against nearby housing, fences and other obstacles. This accumulation of material creates a fire hazard, degrades townships' aesthetics and presents a nuisance to the communities of lake-side towns. This study aimed to examine the effects of various control methods on L.?filiformis in the short and long term. Although herbicide applications, slashing, grazing and burning were found to be effective in controlling the blown L.?filiformis seed heads in the short term, they failed to prevent subsequent reinvasion and can increase its abundance in the long term. The late application of herbicide resulted in an increase in the foliage cover and seed-head biomass of L.?filiformis by up to 37% and 150%, respectively, in the year following the treatment application. The results from this study highlight how management focused on achieving short-term goals, without consideration of the successional trajectory after implementation, can not only fail but be counter-productive in the long term. In order to achieve sustainable management, the fundamental ecological processes that promote the establishment and persistence of the weed need to be addressed.
Controlling Lachnagrostis filiformis (Fairy grass) on dry lake beds in western Victoria, Australia
- Authors: Warnock, Andrew
- Date: 2009
- Type: Text , Thesis , PhD
- Full Text:
- Description: The indigenous grass Lachnagrostis filiformis (Fairy grass) has colonised extensive areas of dry lakebeds in western Victoria, Australia during the current (1997-) drought. Large numbers of the plants' detached seed heads disperse in the wind and lodge against housing, fences, railway lines and other obstacles ... In this study, late season application of Glyphosate based herbicide, slashing, seed broadcasting of Atriplex australasica and Puccinellia perlaxa, grazing and burning were examined ... The results highlight how weed management aimed at achieving short-term goals, without controlling the ecological processes that promote weeds establishment and persistence, can be counter productive in the long-term.
- Description: Doctorate of Philosophy
Controlling wind blown Lachnagrostis filiformis (fairy grass) seed heads in western Victoria
- Authors: Warnock, Andrew , Florentine, Singarayer , Graz, Patrick , Westbrooke, Martin
- Date: 2009
- Type: Text , Conference paper
- Relation: Paper presented at Fourth Victorian Weed Conference : Plants behaving badly - in agriculture and the environment, Mercure Hotel, Geelong, Victoria : 7th-8th October 2009
- Full Text:
- Description: 2003007372
A unique weed problem — the control of fairy grass Lachnagrostis filiformis seedheads on Lake Learmonth in western Victoria
- Authors: Warnock, Andrew , Florentine, Singarayer , Graz, Patrick , Westbrooke, Martin
- Date: 2008
- Type: Text , Conference paper
- Relation: Paper presented at 16th Australian Weeds Conference: Weed management 2008 hot topics in the tropics, Cairns, Queensland : May 18th-22nd, 2008 p. 165-167
- Full Text:
- Description: The native fairy grass (Lachnagrostis filiformis (G. Forst.) Trin.) has colonised extensive areas of dry lake beds in western Victoria during the current drought. Large numbers of the plants’ detached mature panicles (seed heads) lodge against housing, fences, railway lines and other obstacles. This can be a fire hazard, degrades township aesthetics and creates a general nuisance to communities of lakeside towns. Current control measures are costly and only provide short-term solutions. A three-year study commencing in 2006 was designed to assess current and innovative control measures and develop a potential long-term management solution to the problem. Treatments applied to the bed of Lake Learmonth during the first year of the study included late-season glyphosate herbicide at two concentrations, late-season slashing, and seed broadcasting of two native species to reduce L. filiformis inflorescence biomass through competition. Slashing reduced L. filiformis inflorescence biomass and herbicide treatments successfully killed L. filiformis plants, while having no effect on germination of seed collected from sprayed plants. Although these treatments successfully limited the impact of L. filiformis on lakeside towns during the first year, the longer term efficiency is doubted. Treatment effects will be monitored over a further two years.
- Description: 2003006269
Does Geijera parviflora Lindl. (Rutaceae) facilitate understorey species in semi-arid Australia?
- Authors: Warnock, Andrew , Westbrooke, Martin , Florentine, Singarayer , Hurst, Cameron
- Date: 2007
- Type: Text , Journal article
- Relation: Rangeland Journal Vol. 29, no. 2 (2007), p. 207-216
- Full Text:
- Reviewed:
- Description: Species composition under tree canopies often differs from that of surrounding micro-environments. In arid and semi-arid zones, trees can be beneficial to understorey vegetation. This study examined zones of vegetation composition and soil physiochemical parameters associated with Geijera parviflora Lindl. The importance of shade, rainfall redistribution, seed bank and soil moisture were examined. Species abundance, soil moisture, seed bank composition, rainfall redistribution and soil nutrient concentration were measured under five randomly selected mature G. parviflora trees in south-western New South Wales, Australia. To complement the findings from this study, artificial shade plots were constructed in a canopy-free area and species abundance measured seven months after shade construction. The study demonstrated that G. parviflora was associated with zonation of understorey vegetation. Two zones of understorey vegetation were found in relation to G. parviflora: (i) under the tree canopy with high species diversity, and (ii) beyond the canopy, this community being dominated by Dissocarpus paradoxus throughout the year with Crassula colorata appearing after rainfall. The zone beyond the canopy also had lower soil nutrient concentrations. Soil moisture, nutrient concentration and the seed bank density were significantly higher under the canopy. However, the canopy reduced precipitation reaching the soil surface. The effects of the canopy on understorey species composition and soil moisture were enhanced after winter rainfall. Artificial shade increased species abundance and richness under a 90%-shading treatment. The results indicated that G. parviflora generated spatial heterogeneity over the broader plant community increasing species richness, abundance and diversity under the canopy. This emphasises the importance of arid zone trees in conserving understorey plant diversity. Shading, soil nutrient concentration and increased seed bank density and soil moisture appeared to be key influences on the plant communities under the canopy. © Australian Rangeland Society 2007.
- Description: C1
- Description: 2003004817