Changes in dominance of dipteran families on Coral Sea cays over ten years during a period of substantial vegetation change
- Authors: Rich, Deborah , Greenslade, Penelope , Bickel, Dan
- Date: 2014
- Type: Text , Journal article
- Relation: Northern Territory Naturalist Vol. 25, no. (2014), p. 64-76
- Full Text: false
- Reviewed:
- Description: The habitat on the Coringa-Herald group of coral cays within the northern Coral Sea underwent profound change after about 2000 because of extensive dieback of the dominant forest trees. This work summarises surveys on these cays in 1995, 1996, 1997 and 2007, in order to understand the effect on the native insect fauna of the introduced biological control agent, the non-specific predatory ladybird beetle Cryptolaemus montrouzieri (Coleoptera: Coccinellidae), that was liberated to control scale insects (Hemiptera: Coccidae) whose infestation was responsible for the dieback of the forest trees. This paper documents the families of Diptera (flies) collected on the surveys and it records changes in presence and abundance of Chloropidae, Phoridae, Sarcophagidae, Canacidae, Lonchaeidae and Chironomidae sampled in pitfall traps and yellow pans. Despite some differences in collecting methods and seasons between surveys, there is evidence of substantial changes in the presence and relative abundance of these families. The decline of several families on Coringa Cay and on North East Herald Cay between 1995/96 and 2007 could be the result of a trophic cascade of species loss following tree dieback. One of the most conspicuous changes was that Chloropidae increased on North East Herald Cay between 1997 and 2007 following increases in populations of scale insects, but chloropids are not thought to have had a direct role in the control of scale insects.
Comparison of two methods for the isolation of phytolith occluded carbon from plant material
- Authors: Parr, Jeffrey , Sullivan, Leigh
- Date: 2014
- Type: Text , Journal article
- Relation: Plant and Soil Vol. 374, no. 1-2 (2014), p. 45-53
- Full Text: false
- Reviewed:
- Description: Background and aims: Phytolith occluded carbon (PhytOC) is of interest for isotope studies, dating of sediments and the capture and storage of carbon. Many methodologies have been used for the isolation of phytoliths from plant material; however, there are wide disparities in the PhytOC contents when determined by different methodologies. In this study we examine the utility of the two main methods used for quantifying PhytOC. Methods: These methods are: (1) a microwave digestion followed by a Walkley-Black digestion, and (2) H2SO4/H2O2. Results: Method (1) produced PhytOC values over 50 times higher than those acquired by method (2). SEM examination indicated that the differences were likely due to shattering of the phytoliths by method (2) allowing consumption by the acid and peroxide of PhytOC. Conclusion: These results indicate that for the samples analysed here: 1] the modified microwave method allowed the total PhytOC to be measured, 2] the H2SO4/H2O2 method allowed the PhytOC within the tightly packed silica matrix to be measured, and 3] the PhytOC retained within the phytolith cavities could possibly be calculated by subtracting 2] from 1]. For the samples analysed here most of the PhytOC resided in the phytolith cavities. © 2013 Springer Science+Business Media Dordrecht.
Effects of hypoxia and hypercapnia on human HRV and respiratory sinus arrhythmia
- Authors: Brown, Stephen , Barnes, Matthew , Mündel, Toby
- Date: 2014
- Type: Text , Journal article
- Relation: Acta Physiologica Hungarica Vol. 101, no. 3 (2014), p. 263-272
- Full Text: false
- Reviewed:
- Description: Hypercapnia increase minute ventilation (V'E) with little effect on heart rate (HR), whereas hypoxia may increase HR without affecting V'E. However, the effects of hypercania and hypoxia on both heart rate variability (HRV) and the clustering of the heart beats during spontaneous breathing (respiratory sinus arrhythmia -RSA) are not clear. "From abstract"
Enhanced methane hydrate storage using sodium dodecyl sulfate and coal
- Authors: Hao, Shu-Qing , Kim, Sungho , Qin, Yong , Fu, Xue-Hai
- Date: 2014
- Type: Text , Journal article
- Relation: Environmental Chemistry Letters Vol. 12, no. 2 (2014), p. 341-346
- Full Text: false
- Reviewed:
- Description: A potential solution to reduce global warming is to store greenhouse gases. Greenhouse gas storage has been recently improved using several materials and techniques. However, the actual storage capacity is slow, limited, and costly. Here, we tested the use of an accelerating agent, sodium dodecyl sulfate, and coal to produce methane hydrate for methane storage. Experiments of storing methane gas in coal samples have been carried out under high pressures, 4 or 6 MPa, and low temperature of 273.15 K. Results reveal that sodium dodecyl sulfate improved the rate up to 58.26 cm3/min and the capacity up to 179.97 volume at standard temperature and pressure per unit volume of coal. This finding shows that sodium dodecyl sulfate is efficient to accelerate the formation of methane hydrate. We also found that storage capacity increased with pressure. We conclude that our method allows a gas storage capacity higher than any other medium materials reported previously. © 2013 Springer-Verlag Berlin Heidelberg.
Interspecific variations in the faecal microbiota of Procellariiform seabirds
- Authors: Dewar, Meagan , Arnould, John , Krause, Lutz , Dann, Peter , Smith, Stuart
- Date: 2014
- Type: Text , Journal article
- Relation: FEMS Microbiology Ecology Vol. 89, no. 1 (2014), p. 47-55
- Full Text: false
- Reviewed:
- Description: Despite the enormous amount of data available on the importance of gut microbiota in vertebrates (especially mammals), there is no information available on the microbiota of seabirds. Procellariiformes are long-lived seabirds that consume a diet high in lipids and are characterised by their ability to produce and store large amount of stomach oils through the partial digestion of prey (with the exception of the Pelecanoididae). Examining the faecal microbiota of three Procellariiform species (short-tailed shearwater, common diving petrel and fairy prion) provided a unique opportunity to not only characterise the gastrointestinal (GI) microbial composition of seabirds but to also examine the influence of stomach oils on the microbial community. The results indicated that Procellariiform seabirds host a highly diverse community of faecal microorganisms, dominated by three phyla (Firmicutes, Proteobacteria and Bacteroidetes) and that each species has its own species-specific GI microbiota. In addition, significant differences were observed in the microbial communities of oil-producing and non-oil-producing seabirds. This study is the first whole-community examination and classification of the faecal microbiota of Procellariiform seabirds.
Looking forward through the past: Identification of 50 priority research questions in palaeoecology
- Authors: Mills, Keely
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Ecology Vol. 102, no. 1 (2014), p. 256-267
- Full Text: false
- Reviewed:
- Description: Priority question exercises are becoming an increasingly common tool to frame future agendas in conservation and ecological science. They are an effective way to identify research foci that advance the field and that also have high policy and conservation relevance. To date, there has been no coherent synthesis of key questions and priority research areas for palaeoecology, which combines biological, geochemical and molecular techniques in order to reconstruct past ecological and environmental systems on time-scales from decades to millions of years. We adapted a well-established methodology to identify 50 priority research questions in palaeoecology. Using a set of criteria designed to identify realistic and achievable research goals, we selected questions from a pool submitted by the international palaeoecology research community and relevant policy practitioners. The integration of online participation, both before and during the workshop, increased international engagement in question selection. The questions selected are structured around six themes: human–environment interactions in the Anthropocene; biodiversity, conservation and novel ecosystems; biodiversity over long time-scales; ecosystem processes and biogeochemical cycling; comparing, combining and synthesizing information from multiple records; and new developments in palaeoecology. Future opportunities in palaeoecology are related to improved incorporation of uncertainty into reconstructions, an enhanced understanding of ecological and evolutionary dynamics and processes and the continued application of long-term data for better-informed landscape management. Synthesis. Palaeoecology is a vibrant and thriving discipline, and these 50 priority questions highlight its potential for addressing both pure (e.g. ecological and evolutionary, methodological) and applied (e.g. environmental and conservation) issues related to ecological science and global change.
Seasonal and interannual variation in vegetation composition : Implications for survey design and data interpretation
- Authors: Schultz, Nick , Reid, Nick , Lodge, Greg , Hunter, John
- Date: 2014
- Type: Text , Journal article
- Relation: Austral Ecology Vol. 39, no. 7 (2014), p. 755-766
- Full Text: false
- Reviewed:
- Description: Understanding how vegetation composition varies with season and interannual climate variability is important for any ecological research that uses vegetation data derived from surveys for the basis of inference. Misunderstanding this variation can influence land management and planning decisions, leading to poor implementation of biodiversity offsetting mechanisms, for example. We monitored plots (400 m2) grazed by livestock paired with adjacent ungrazed plots in derived native pastures four times a year over 2.5 years on the North-West Slopes of New South Wales. Species density in plots varied greatly with season and interannual rainfall. Highest species density was recorded in spring, though species density in summer was not significantly lower, nor was a spring–summer peak in species density evident in the 2009 drought. Surveys in spring 2008 had the highest species density, and recorded only 60–72% of the total species recorded at each site over 2.5 years. Variation in the proportion of total site diversity represented in combinations of two or three surveys was large, though the best combinations comprised surveys from spring and summer in years of above-average rainfall, either from the same spring-summer, or from different years. Compositional differences among sites were much greater than within sites, showing that differences among sites related to broad environmental gradients were not overwhelmed by seasonal and interannual variability in site composition. When grazing was excluded, there was no evidence of competitive exclusion by the dominant grasses, and no directional shift in composition. The implications of these findings for ecological research depend on the question being addressed: if capturing a large proportion of site diversity is important, then surveys must be carefully timed, or repeat surveys must be conducted. Single surveys did not effectively capture site diversity for use in biodiversity offsetting, and the timing of repeat surveys was critical.
Age-related differences revealed in australian fur seal arctocephalus pusillus doriferus gut microbiota
- Authors: Smith, Stuart , Chalker, Andrea , Dewar, Meagan , Arnould, John
- Date: 2013
- Type: Text , Journal article
- Relation: FEMS Microbiology Ecology Vol. 86, no. 2 (2013), p. 246-255
- Full Text: false
- Reviewed:
- Description: The gut microbiota of Australian fur seals (Arctocephalus pusillus doriferus) was examined at different age classes using fluorescent in situ hybridisation (FISH) and 16S rRNA gene pyrosequencing. The FISH results indicated that in the fur seal groups, the predominant phyla are Firmicutes (22.14-67.33%) followed by Bacteroidetes (3.11-15.45%) and then Actinobacteria (1.4-5.9%) consistent with other mammals. Phylum Proteobacteria had an initial abundance of 1.8% in the 2-month-old pups, but < 1% of bacterial numbers for the other fur seal age groups. Significant differences did occur in the abundance of Clostridia, Lactobacilli and Bifidobacteria between 2 months pups and 9 months pups and adult fur seals. Results from the 16S rRNA gene pyrosequencing supported the FISH data and identified significant differences in the composition of Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, Verrucomicrobia and Fusobacteria at all ages. Class Clostridia in phylum Firmicutes dominates the microbiota of the 2 months and 9 months seal pups, whilst class Bacilli dominates the 6 months pups. In addition, a high level of dissimilarity was observed between all age classes. This study provides novel insight into the gut microbiota of Australian fur seals at different age classes. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.
Identification of observed factors that predict bather water-immersions at beaches
- Authors: Morgan, Damian , Ozanne-Smith, Joan
- Date: 2013
- Type: Text , Journal article
- Relation: Ocean and Coastal Management Vol. 84, no. (2013), p. 180-183
- Full Text: false
- Reviewed:
- Description: Coastal managers require accurate and relevant visitor information to manage visitor's leisure and recreation experiences. The study reports the development of a predictive model of bather water-immersions at selected beaches in Victoria, Australia for the daily peak-bathing period. Criterion variable data were collected over two summer periods to provide external validation. Predictor variables were observed on site or from secondary data. Results showed a statistically significant model meeting the required assumptions: Adjusted R2 = 0.65: F2, 292 = 270.50, p < 0.001; R2 95% CI: 0.58 to 0.71. Significant predictor variables were daily maximum air temperature and level of service (no service, toilet/water, or kiosk/club). Further research is required to assess the model generalisability to other beach locations and time frames
Koalas Phascolarctos cinereus in Framlingham Forest, south-west Victoria : Introduction, translocation and the effects of a bushfire
- Authors: Wallis, Robert
- Date: 2013
- Type: Text , Journal article
- Relation: Victorian Naturalist Vol. 130, no. 1 (2013), p. 37-40
- Full Text: false
- Reviewed:
- Description: Koalas were introduced into Framlingham Forest, south-west Victoria, in 1971 and the population grew rapidly. By the 1990s the forest was suffering severe defoliation and many trees preferred by Koalas had been over-browsed. In 1998/99 around 1100 Koalas were captured, the males sterilised and animals translocated to other suitable habitats in western Victoria. Some habitat restoration was subsequently undertaken. In 2007 a deliberately lit fire destroyed most eucalypt foliage and many Koalas were killed or burned and removed by wildlife carers and DSE staff. A survey in 2011 found only two Koalas in the area. A Koala management plan for Framlingham Forest has been prepared.
- Description: 2003011109
Molecular data contradicts historical records and cautions translocation of the Lord Howe Island masked owl
- Authors: Hogan, Fiona , Campbell, Catriona , Harrison, Katharine , Milledge, David , Cooke, Raylene
- Date: 2013
- Type: Text , Journal article
- Relation: Biological Conservation Vol. 159, no. (2013), p. 313-320
- Full Text: false
- Reviewed:
- Description: Masked owls, reputedly all of the Tasmanian race (Tyto novaehollandiae castanops) were introduced onto Lord Howe Island (LHI) in the 1920s in an attempt to control the black rat (Rattus rattus). This attempt, however, has been unsuccessful and a co-eradication of the rats and masked owls has been planned to reduce the threat to endemic species and breeding seabirds on the island. As the Tasmanian masked owl is considered endangered, translocation of LHI masked owls to Tasmania has been suggested. Before translocation is considered the ancestry of the LHI masked owl needs to be confirmed, as LHI masked owls are typically smaller and paler than individuals occurring in Tasmania. Here we sequenced three sections of mitochondrial gene regions: cytochrome b, ATP6 and ND3 to assess the provenance of the LHI masked owl and screened a suite of microsatellite loci isolated from the barn owl (Tyto alba) to assess contemporary divergence. Phylogenetic analysis revealed two clades, one exhibited by individuals from LHI and south-eastern mainland Australia and the second by those from Tasmania. Cross species amplification of microsatellite loci was successful, with 18 loci polymorphic. Genotypic data revealed significant sub-structuring between LHI, south-eastern mainland Australia and Tasmania. Data presented here indicate that the south-eastern mainland masked owl was introduced to LHI and subsequently reproduced. The genetic integrity of the LHI masked owl population is therefore questionable and as such LHI individuals may not be suitable for translocation to Tasmania.
Reliable genotyping of the koala (Phascolarctos cinereus) using DNA isolated from a single faecal pellet
- Authors: Wedrowicz, Faye , Karsa, Mawar , Mosse, Jennifer , Hogan, Fiona
- Date: 2013
- Type: Text , Journal article
- Relation: Molecular Ecology Resources Vol. 13, no. 14 (2013), p. 634-641
- Full Text: false
- Reviewed:
- Description: Abstract The koala, an Australian icon, has been added to the threatened species list. Rationale for the listing includes proposed declines in population size, threats to populations (e.g. disease) and loss and fragmentation of habitat. There is now an urgent need to obtain accurate data to assess the status of koala populations in Australia, to ensure the long-term viability of this species. Advances in genetic techniques have enabled DNA analysis to study and inform the management of wild populations; however, sampling of individual koalas is difficult in tall, often remote, eucalypt forest. The collection of faecal pellets (scats) from the forest floor presents an opportunistic sampling strategy, where DNA can be collected without capturing or even sighting an individual. Obtaining DNA via noninvasive sampling can be used to rapidly sample a large proportion of a population; however, DNA from noninvasively collected samples is often degraded. Factors influencing DNA quality and quantity include environmental exposure, diet and methods of sample collection, storage and DNA isolation. Reduced DNA quality and quantity can introduce genotyping errors and provide inaccurate DNA profiles, reducing confidence in the ability of such data to inform management/conservation strategies. Here, we present a protocol that produces a reliable individual koala genotype from a single faecal pellet and highlight the importance of optimizing DNA isolation and analysis for the species of interest. This method could readily be adapted for genetic studies of mammals other than koalas, particularly those whose diet contains high proportions of volatile materials that are likely to induce DNA damage.
The aerial invertebrate fauna of subantarctic Macquarie Island
- Authors: Hawes, Timothy , Greenslade, Penelope
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Biogeography Vol. 40, no. 8 (2013), p. 1501-1511
- Full Text: false
- Reviewed:
- Description: Aim: The extent and diversity of invertebrate aerial dispersal both on remote islands and in polar regions has long been of interest to biogeographers. We therefore monitored the airborne dispersal of insects and other micro- and macroinvertebrates to and on Macquarie Island in order to assess (1) the magnitude and composition of local aerial dispersal activity by the island's invertebrate fauna, and (2) the potential for exotic arrival and establishment. Location: Macquarie Island. Methods: Two robust wind-traps were run year-round on Macquarie Island from 1991 to 1994 to collect airborne insects and other micro- and macroinvertebrates. Results: More than 3000 invertebrates were caught in these traps over the sampling period in the most comprehensive aerial survey of subantarctic invertebrates to date. Representatives of seven orders of Insecta were captured: Psocoptera, Thysanoptera, Hemiptera, Coleoptera, Diptera, Lepidoptera and Hymenoptera. Other taxa captured included other arthropods (Arachnida and Collembola) but also terrestrial Gastropoda. Evidence of possible long-distance dispersal (LDD) was limited to two exotic catches (one species of Collembolon, and one species of Thysanoptera). The abundance and composition of indigenous invertebrates caught in the traps indicates that the frequency of short-distance dispersal (SDD) movements on the island far exceeds that which had previously been realized. Main conclusions: More than half the total catch (53%) was of flightless (i.e. passively dispersed) invertebrates, with 84% of them flightless in one of the two traps. The extent of passive dispersal movements is consistent, with most invertebrates being widely distributed at a whole-island scale. Aerial dispersal may act as a conduit for non-indigenous arrivals but this occurs infrequently. Other explanations for exotic species in traps are equally likely. The implications of these findings are discussed in relation to terrestrial invertebrate biogeography. © 2013 Blackwell Publishing Ltd.
- Description: 2003011217
The rare collembolan genus, Temeritas (Symphypleona: Sminthuridae), in southern Australia : Systematics, distribution and conservation status
- Authors: Greenslade, Penelope
- Date: 2013
- Type: Text , Journal article
- Relation: Victorian Naturalist Vol. 130, no. 1 (2013), p. 45-48
- Full Text: false
- Reviewed:
- Description: A brief summary of the genus Temeritas is given with distributions of the four described Australian species and records of other species in the genus. A spelling correction is documented for the Western Australian species and a new name for the Victorian species is formally proposed here as the original name is preoccupied. Characters that distinguish Temeritas from allied genera are noted and the conservation status of the three southern species and Collembola in general are discussed.
- Description: 2003011110
Ecology of Heard Island Diptera
- Authors: Greenslade, Penelope , Vernon, Philippe , Smith, Derek
- Date: 2012
- Type: Text , Journal article
- Relation: Polar Biology Vol. 35, no. 6 (2012), p. 841-850
- Full Text: false
- Reviewed:
- Description: Phenology, distribution and abundance of three Diptera species on Heard Island were investigated to provide baseline data for monitoring the effect on climate change on populations. Five vegetation types at two localities were sampled in two different years, firstly in the summer of 1987–1988 at Atlas Cove and secondly at Spit Bay over 12 months from summer 1992 to summer 1993. Pitfall traps and soil core extractions were operated in summer at both localities and pitfalls alone for 12 months from Spit Bay. The wingless Anatalanta aptera was the most abundant species in traps at Atlas Cove with most individuals collected from Poa tussock grassland, half as many from Pringlea and Azorella vegetation and fewest with a significantly higher level of asymmetry in the large katepisternal setae, from Azorella and Fellfield. Calycopteryx moseleyi was the most abundant fly in traps at Spit Bay, and A. maritima was the least abundant at both localities. Monthly pitfall catches from 1992–1993 indicated that A. aptera was active in most months of the year apart from winter, females early in the season and males active throughout the summer; teneral individuals only detected in January. C. moseleyi was more strongly seasonal with peak adult numbers occurring in January. Amalopteryx maritima was least seasonal in activity. Asymmetry in A. aptera suggests that it was at the limit of its ecological tolerance in Fellfield and Azorella on Heard Island. Changes caused by climate warming or invasive species are mooted.
Fetal sex affects expression of renin-angiotensin system components in term human decidua
- Authors: Wang, Yu , Pringle, Kirsty , Sykes, Shane , Marques, Francine , Morris, Brian , Zakar, Tamas , Lumbers, Eugenie
- Date: 2012
- Type: Text , Journal article
- Relation: Endocrinology Vol. 153, no. 1 (January 2012), p. 462-468
- Full Text: false
- Reviewed:
- Description: The maternal decidua expresses the genes of the renin-angiotensin system (RAS). Human decidua was collected at term either before labor (i.e. cesarean delivery) or after spontaneous labor. The mRNA for prorenin (REN), prorenin receptor (ATP6AP2), angiotensinogen (AGT), angiotensinconverting enzymes 1 and 2 (ACE1 and ACE2), angiotensin II type 1 receptor (AGTR1), and angiotensin 1-7 receptor (MAS1) were measured by quantitative real-time RT-PCR. Decidual explants were cultured in duplicate for 24 and 48 h, and all RAS mRNA, and the secretion of prorenin, angiotensin II, and angiotensin 1-7 was measured using quantitative real-time RT-PCR, ELISA, and radioimmunoassay, respectively. In the decidua collected before labor, REN mRNA levels were higher if the fetus was female. In addition, REN, ATP6AP2, AGT, and MAS1 mRNA abundance was greater in decidual explants collected from women carrying a female fetus, as was prorenin protein. After 24 h, ACE1 mRNA was higher in the decidual explants from women with a male fetus, whereas after 48 h, both ACE1 and ACE2 mRNA was higher in decidual explants from women with a female fetus. Angiotensin II was present in all explants, but angiotensin 1-7 levels often registered below the lower limits of sensitivity for the assay. After labor, decidua, when compared with nonlaboring decidua, demonstrated lower REN expression when the fetus was female. Therefore, the maternal decidual RAS is regulated in a sex-specific manner, suggesting that it may function differently when the fetus is male than when it is female.
- Description: C1
Field vaccination of sheep with a larval-specific antigen of the gastrointestinal nematode, Haemonchus contortus, confers significant protection against an experimental challenge infection
- Authors: Piedrafita, David , De Veer, Michael , Lydall, Jayne , Kraska, Troy , Elhay, Martin , Meeusen, Els
- Date: 2012
- Type: Text , Journal article
- Relation: Vaccine Vol. 30, no. 50 (2012), p. 7199-7204
- Full Text: false
- Reviewed:
- Description: The availability of effective vaccines would add a valuable tool to the management of gastrointestinal nematode infections in livestock. While some experimental vaccines have shown protection in laboratory trials, few have been tested in the field. In the present study, eight month old sheep kept on pasture were treated with anthelmintic 8 weeks before vaccination with a larval surface antigen of the nematode parasite, Haemonchus contortus, under a commercially acceptable protocol, i.e. 2 immunizations using a commercial adjuvant; they were then given a controlled challenge infection 4 weeks later in indoor pens. Vaccination of sheep with 4 increasing doses of antigen resulted in significant reductions of 61% and 27% in cumulative faecal egg counts in the two highest dose groups, and a 69% reduction in worm burden in the highest dose group. Blood loss, as determined by packed cell volume, was also significantly reduced in the highest dose group of sheep. One outlier sheep showed an unusual increase in egg count without a concomitant increase in worm burden compared to the control sheep, indicating a vaccine-induced stress response. Antigen-specific serum antibody levels steadily increased in sheep while on pasture and decreased when transported to indoor pens. No difference in antibody levels could be detected between vaccinated and unvaccinated sheep, but all showed increased antibody levels compared to uninfected control sheep kept in indoors pens for 2–3 months, suggesting sheep were sensitized to the larval antigen either from low dose pasture contamination or cross reaction with pasture-related antigens. The results of these studies confirm the protective properties of the larval surface antigen and its protective effect when vaccinations are performed in the field.
Floodplain ants show a stronger response to an extensive flood than to variations in fallen-timber load
- Authors: Horrocks, Gregory , Cunningham, Shaun , O'Dowd, Dennis , Thomson, James , Mac Nally, Ralph
- Date: 2012
- Type: Text , Journal article
- Relation: Austral Ecology Vol. 37, no. 4 (2012), p. 518-528
- Full Text: false
- Reviewed:
- Description: Understanding how species respond to differences in resource availability is critical to managing biodiversity under the increasing pressures associated with climate change and growing human populations. Over the last century, the floodplain forests of Australia's largest river system, the Murray-Darling Basin, have been much affected by intensive harvesting of timber and firewood, and increasingly stressed by river regulation and, recently, an extended drought. Fallen timber - logs and shed branches - is known to play a key role in the ecology of several important species on these floodplains. Here, we monitored the response of the ant assemblages of a floodplain forest along the Murray River to a large-scale (34ha) experimental manipulation of fallen-timber load (0 to 80tha -1) over 4years. The forest was subjected to an incidental, extensive flood that enabled us to examine how two important stressors (timber removal and river regulation) affect ant assemblages. Ants showed little response to the proximity of fallen timber within plots, prior to the flood, or to different loads among plots, unlike other floodplain biota. After the flood, both ant abundance and species richness increased and species composition changed. However, this increase in species richness after flooding was less pronounced in plots with higher amounts of fallen timber. Managing river red gum forest using a mosaic of flood regimes, more representative of historical conditions, is likely to be the most effective way to maintain and enhance the diversity of ants and other biota on these important floodplains. © 2011 The Authors. Austral Ecology © 2011 Ecological Society of Australia.
Investigations into the thiamine and riboflavin content of malt and the effects of malting and roasting on their final content
- Authors: Hucker, Barry , Wakeling, Lara , Vriesekoop, Frank
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Cereal Science Vol.56, no.2 (2012), p.300-306
- Full Text: false
- Reviewed:
- Description: A simple and effective method for the analysis of thiamine (B1) and riboflavin (B2) vitamers, in unmalted and malted grains, by high performance liquid chromatography (HPLC) has been developed. This method makes use of trichloroacetic acid (TCA) as an extraction medium to effectively clean up the sample and analyze the vitamer content with high accuracy (R2 > 0.9992; %RSD < 5%). This method was employed in the routine analysis of a wide range of malted and unmalted grains, and it was found that lighter colored malts contain higher concentrations (2–5 times higher) of thiamine and riboflavin vitamers compared to darker colored malts. The malting process has no effect on the overall riboflavin content; however, both steeping and kilning processes cause increases in thiamine vitamer content. Roasting profiles show that thiamine and riboflavin vitamer concentrations are significantly effected when the temperature reaches 120 °C, which explains why roasted products have lower vitamer content than paler malts.
- Description: A simple and effective method for the analysis of thiamine (B
Is there a role for rare variants in DRD4 gene in the susceptibility for ADHD Searching for an effect of allelic heterogeneity
- Authors: Tovo-Rodrigues, Luciana , Rohde, Luis , Roman, Tatiana , Schmitz, Marcelo , Polanczyk, Guilherme , Zeni, Cristian , Marques, Francine , Contini, Veronica , Grevet, Eugenio , Belmonte-De-Abreu, Paulo , Bau, Claiton , Hutz, Mara
- Date: 2012
- Type: Text , Journal article
- Relation: Molecular Psychiatry Vol. 17, no. 5 (May 2012), p. 520-526
- Full Text: false
- Reviewed:
- Description: Although several studies have demonstrated an association between the 7-repeat (7R) allele in the 48-bp variable number of tandem repeats (VNTRs) in the exon 3 at dopamine receptor D4 (DRD4) gene and attention-deficit/ hyperactivity disorder (ADHD), others failed to replicate this finding. In this study, a total of 786 individuals with ADHD were genotyped for DRD4 exon 3 VNTR. All 7R homozygous subjects were selected for VNTR re-sequencing. Subjects homozygous for the 4R allele were selected paired by age, ancestry and disorder subtypes in order to have a sample as homogeneous as possible with 7R/7R individuals. Using these criteria, 103 individuals (66 with ADHD and 37 control individuals) were further investigated. An excess of rare variants were observed in the 7R alleles of ADHD patient when compared with controls (P = 0.031). This difference was not observed in 4R allele. Furthermore, nucleotide changes that predict synonymous and non-synonymous substitutions were more common in the 7R sample (P = 0.008 for total substitutions and P = 0.043 for non-synonymous substitutions). In silico prediction of structural/functional alterations caused by these variants have also been observed. Our findings suggest that not only repeat length but also DNA sequence should be assessed to better understand the role of DRD4 exon 3 VNTR in ADHD genetic susceptibility.
- Description: C1