Conference Posters

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7703

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Start date: 2013Has files: Yes

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Now showing 1 - 10 of 36
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    Environmental drivers of antimicrobial resistance – cadmium contamination & antibiotic resistance in soil samples from a rural airstrip.
    (2023-12-05) Heydari A; Kim N; Biggs P; Horswell J; Gielen G; Siggins A; Bromhead C; Palmer B
    Environmental contamination with both inorganic and organic compounds is a growing problem globally. In this study we investigated links between heavy metal contamination of soil and selection for antibiotic resistance in soil bacteria. Soil samples taken at 10 m intervals along the length of a 70 m transect of a rural airstrip used for aerial topdressing located in Belmont Regional Park near Wellington were analysed for heavy metal content and resistance profiles of heterotrophic bacteria cultured were characterised. A gradient of cadmium contamination (a known contaminant of superphosphate fertiliser) ranging from 1.14 to 7.20 mg kg-1 of dry soil was detected in the samples. Total bacterial counts were significantly reduced at the most heavily contaminated subsites, with >60% of isolates resistant to 0.01 mM CdCl2. The ratio of antibiotic resistant isolates to total CFU was significantly higher at the most contaminated compared to the least contaminated subsite for five common antibiotics. Metagenomic analysis of total DNA from three subsites showed significantly different profiles at all taxonomic levels. This suggests environmental contamination with heavy metals may be a significant and under-appreciated driver of selection for antimicrobial resistance.
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    Prevalence of liver fluke on West Coast farms of the South Island of New Zealand sampled in the autumn and spring of consecutive lactations
    (2021-07-19) Dowling A; Pomroy W; Howe L; Scott I; Lawrence K
    The aim of this study was to determine the occurrence of Fasciola hepatica infection in dairy cows in this West Coast of the South Island using an ELISA of bulk milk samples (n=430) collected on one of two occasions during March (autumn) 2017 and again in October (spring). All samples were analysed using the IDEXX Fasciolosis Verification kit which estimates the infection level in the herd in 4 categories; >50% infestation (strong); 20-50% infestation (medium); <20% infestation (low); no infection. A subset (n=99) were tested twice with a one week interval to determine repeatability. A short survey was also posted to each supplier with 157 completed. Of the 430 farms tested 133 (31%) were negative, 49 (11%) had a low infestation, 62 (14%) had a medium infestation and 186 (43%) had a strong infestation. GIS mapping of the farm locations indicated geographic grouping of farms with more severe fluke infestations. The 99 samples tested twice substantially agreed (Kappa = 0.7). Farms tested in both autumn and spring (n= 369) moderately agreed (Kappa 0.43) with an overall decrease in the spring. From the survey 85% of farmers were aware of liver fluke on their farm during the last 5 years and 70% treated their cows with a flukicide during the dry period (winter) including 92% of the farms that tested negative. This study indicates fasciolosis is common in this region with a disturbing number with a high prevalence in their herds. It also showed a decrease from autumn to following spring levels.
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    Acceptability of LGBTQ-Affirmative Cognitive Behavioral Group Therapy for Youth: Results from a Pilot Study
    (2023-04-01) Seager van Dyk I; Layland EK; Soulliard ZA; Pachankis JE
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    A genetic approach to identify amino acids in Gcn1 required for Gcn2 activation (poster)
    (8/09/2022) Schiemann A; Gottfried S; Sattlegger E
    The General Amino Acid Control stress signalling pathway allows cells to sense and overcome starvation. One of the major players in this pathway is the protein kinase Gcn2 found in all eukaryotic cells. Activation of Gcn2 leads to phosphorylation of the alpha subunit of eukaryotic translation initiation factor (eIF2α), which then leads to the re-programming of the cell’s gene transcription and translation profile, and ultimately allowing cells to cope with and overcome starvation. For sensing starvation, Gcn2 must directly bind to its effector protein Gcn1. This interaction is mediated via a region in Gcn1 called the RWD binding domain (RWDBD). Overexpression of the RWDBD alone impairs Gcn2 activation through disrupting endogenous Gcn1-Gcn2 interaction, hampering eIF2α phosphorylation, and consequently cells cannot overcome starvation and fail to grow.  This dominant negative phenotype is dependent on Arg-2259 in RWDBD.  Taking advantage of this phenotype in yeast, we here found that the dominant negative phenotype was reverted by each of four amino acid substitutions, K2270A, R2289A, R2297A, and K2301A.  This correlated with increased eIF2α phosphorylation levels, suggesting their relevance for Gcn2 activation.  All but Lys-2270 are fully surface exposed, suggesting that these amino acids may directly contact Gcn2.  We also found amino acid substitutions that enhanced the dominant negative phenotype of the overexpressed RWDBD, and correlated with further reduction in eIF2α-P levels.  Our findings suggest that two helices in Gcn1 constitute at least one Gcn2 contact point.
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    Exploring root traits associated with increased yield under water deficit in perennial ryegrass (Lolium perenne L.) germplasm of Mediterranean and European origins.
    (2015-10) Huassion S; Matthew C; Naeem M; Easton HS
    Exploring root traits associated with increased yield under water deficit in perennial ryegrass (Lolium perenne L.) germplasm of Mediterranean and European origins Sajjad Hussain1, Cory Matthew2, Muhammad Naeem3, H. Sydney Easton4 1Plant Genetic Resources Institute, National Agricultural Research Center, Islamabad, Pakistan, 2Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand, 3Federal Seed Certification and Registration Department, Islamabad, Pakistan, 4AgResearch, Palmerston North, New Zealand. Contact: shmalik25@hotmail.com Introduction Perennial ryegrass (Lolium perenne L.) is now one of the most widely used forage grass species in temperate pastoral agriculture and in recent years breeding for improved performance in summer drought conditions has become a focus. Germplasm of Spanish origin has been widely used in New Zealand plant breeding (Stewart, 2006), but another possibility that has attracted comparatively little research to date is introgression of summer dormant germplasm of North African origin with material of European origin. Methods Plants of a New Zealand-bred perennial ryegrass cultivar “Grasslands Samson”, a summer dormant Australian cultivar “Medea” developed in the 1960’s from germplasm of Mediterranean origin (Silsbury, 1961), and the F1 and F2 progenies of the two parents were compared during summer 2010-11 in a glasshouse study at Palmerston North, New Zealand. The experiment compared rooting behavior and herbage yield of the two cultivars and studied the pattern of inheritance of those traits to F1 and F2 progeny. Plants grown in 100 cm lengths of soil-filled PVC pipes were initially bottom-watered in 200 liter drums and then drought was imposed by gradually lowering the water table until plants survived on water retained in the soil profile. At a concluding destructive harvest, herbage yield (DW) and tiller number (TN) were recorded, while total root mass (Rt), coarse root mass (Rc) fine root mass (Rf) and gravimetric soil moisture % (SMC) were all measured for three soil depths (0-30, 30-60 and below 60 cm). From these data root:shoot ratio (R:S), deep root (below 30 cm): shoot ratio (DR:S), an index of deep rooting (% total root below 30 cm, IDR), and DW/(0.2 – SMC) as an index of efficient water use (IEWU) were derived. Results and Discussion Medea exhibited deep rooting compared to Grasslands Samson indicated by higher R:S, DR:S and IDR, that had never been studied since its release in Australia. However, it had lower IWU, 83% lower DW and 87% lower TN than Grasslands Samson – a characteristic of Mediterranean origin pasture species. On the question of introgressing root traits of Medea to Grasslands Samson: in the F1 generation, some plants surpassed Medea for some root traits (eg DR:S and IDR), while F2 plants were similar to Grasslands Samson parents, However, within Grasslands Samson itself some plants showed high IEWU. Conclusion Introgression of Medea genes into Grasslands Samson will not be straight forward. However, direct selection for maintenance of growth under moderate water deficit with reduced soil moisture extraction per unit DW is an immediate option for improving drought tolerance in perennial ryegrass, providing the trait proves sufficiently heritable. Stewart AV (2006) Genetic origins of perennial ryegrass (Lolium perenne) for New Zealand Pastures. Pp11-20 In: Breeding for success: diversity in action, (ed, CF. Mercer) Proceedings of the 13th Australasian Plant Breeding Conference, Christchurch, NZ. Silsbury JH (1961) A study of dormancy, survival and other characteristics in Lolium perenne L. at Adelaide, SA. Aust. J. Ag. Res.12:1-9.
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    A genome-wide scan of positive selection signature using Ovine Infinium® HD SNP BeadChip in two Romney lines, selected for resistance or resilience to nematodes
    (3/07/2017) Yan J; Dukkipati VSR; Blair HT; Biggs PJ; Hamie JC; Greer A
    A study was undertaken to identify selection signatures associated with resistance to gastrointestinal nematodiasis in sheep. Ninety-three Romney sheep from two selection lines (resistant or resilient) were genotyped using the Ovine Infinium® HD SNP BeadChip, and extended haplotype homozygosity (EHH) and site-specific extended haplotype homozygosity (EHHS) analyses were undertaken. In total, 224 SNPs (147 in EHH and 77 in EHHS) were found to be significant (p <0.0001). Preliminary exploration of 10 SNPs found them to be located within two previously identified QTLs, namely LATRICH_2 and FECGEN, which were associated with nematode larval count and faecal egg count, respectively.
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    Engaging in spaces: How mature distance students fit study into their homes and lives
    (2/07/2013) Kahu ER
    In order to fit study around family and work, a third of mature aged tertiary students in New Zealand study by distance. By enabling students to study when and where they want, distance study is said to overcome the barriers of space and time. But space and time must still be found and the blurring of the physical boundaries between study and home creates new challenges. While much has been written about how distance students juggle time, little has considered how they manage space; yet it is often the availability of an appropriate learning space that determines not just when and where they study, but the quality of their engagement. This qualitative study, following 19 mature aged distance students and their families through their first semester, examines how the students carved learning spaces from their busy lives, the nature of those spaces, and the impact this had on their engagement. For some, a space without other people was the essential characteristic and they achieved this through either a physical separation strategy such as studying at work, or a temporal separation strategy such as studying only when children were at school. For others, isolation was a barrier to their engagement and they gravitated to shared living spaces. Individual lifeload, context, and personal preference mean there are no right or wrong choices, but family support is a critical influence on the success of different strategies.
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    Characterising the drinking water microbiome on campgrounds in New Zealand
    (23/10/2012) Phiri BJ; Biggs PJ; Prattley DJ; Stevenson MA; Rainey PB; French NP
    Whole-genome, 16S and 18S ribosomal RNA (rRNA) analyses combined with conventional isolation techniques are being applied to profile microbial community DNA associated with drinking water on campgrounds. The current study has a serial cross-sectional design and is being conducted on 15 campgrounds that are situated across New Zealand (Figure 1) and are managed by the Department of Conservation (DOC). Preliminary results generally show low Escherichia coli counts in water, suggesting minimal faecal contamination, and a low proportion of faecal samples were positive for Campylobacter and Giardia.
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    Differential gene expression in earthworms exposed to different concentrations of Cadmium
    (Conference organisers, 29/06/2018) Thunders M; Dharmadasa P; Kim N
    Introduction. Cadmium (Cd) is a common contaminant found in many foods, accumulates throughout life and, in high doses, is a significant health hazard for humans. Cadmium is of interest because its concentration in agricultural soils has become elevated over time; with dietary intake in Western countries often close to tolerable limits. Analysis of change in gene expression in response to environmental stressors could potentially aid in risk assessment and biomarker development for human studies. Eisenia fetida are commonly used in ecotoxicological studies. Object. To look at the impact of cadmium concentration on gene expression through comparative analysis of transcriptome data from E. fetida exposed to zero, low, medium and high doses of cadmium. Methods. Artificial soil was spiked with three different Cd solutions [...]
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