198 research outputs found
The Experience of using Facebook as an Educational Tool
Social Networking Sites (SNS) such as Facebook are widely used by student populations and are increasingly used by the population generally. Researchers have considered the benefits of using SNS for educational purposes. This qualitative study involved interviews with seven academic members of staff at one UK university who currently use
Facebook in their teaching. The study provides a unique insight into the views of teaching staff who use Facebook in their classroom, gaining an understanding of their experience and views of using SNS as part of their teaching
Pathogenicity of Botryosphaeria species isolated from declining grapevines in sub tropical regions of Eastern Australia
From 2002 to 2004, vines from 11 vineyards in the Hunter Valley region and from 4 vineyards in Mudgee (New South Wales, Australia) were inspected for foliar and wood symptoms of Eutypa dieback and Botryosphaeria canker. Eutypa lata was not isolated, however species of Botryosphaeria were frequently isolated from dead and declining spurs, cordons and trunks. Two species conforming to the anamorphs of Diplodia and Fusicoccum were isolated. Cultures on PDA producing a yellow pigment, and hyaline aseptate conidia (14-23.5 x 8-13 μm in size) were identified as B. lutea. Cultures with dark brown, 1-septate, ornamented conidia (15-25 x 8-14 μm in size) at maturity were identified as B. obtusa. Pathogenicity tests were conducted on detached green shoots, detached one-year-old canes and glasshouse-grown grapevines. In all situations, disease symptoms were reproduced and Koch’s postulates were fulfilled. The results demonstrate the potential of B. obtusa and B. lutea as primary pathogens of Vitis vinifera.
The influence of participant characteristics on the relationship between cuff pressure and level of blood flow restriction
Purpose: Previous investigations to establish factors influencing the blood flow restriction (BFR) stimulus have determined cuff pressures required for complete arterial occlusion, which does not reflect the partial restriction prescribed for this training technique. This study aimed to establish characteristics that should be accounted for when prescribing cuff pressures required for partial BFR. Methods: Fifty participants were subjected to incremental blood flow restriction of the upper and lower limbs by proximal pneumatic cuff inflation. Popliteal and brachial artery diameter, blood velocity and blood flow was assessed with Doppler ultrasound. Height, body mass, limb circumference, muscle–bone cross-sectional area, adipose thickness (AT) and arterial blood pressure were measured and used in different models of hierarchical linear regression to predict the pressure at which 60 % BFR (partial occlusion) occurred. Results: Combined analysis revealed a difference in cuff pressures required to elicit 60 % BFR in the popliteal (111 ± 12 mmHg) and brachial arteries (101 ± 12 mmHg). MAP (r = 0.58) and AT (r = −0.45) were the largest independent determinants of lower and upper body partial occlusion pressures. However, greater variance was explained by upper and lower limb regression models composed of DBP and BMI (48 %), and arm AT and DBP (30 %), respectively. Conclusion: Limb circumference has limited impact on the cuff pressure required for partial blood flow restriction which is in contrast to its recognised relationship with complete arterial occlusion. The majority of the variance in partial occlusion pressure remains unexplained by the predictor variables assessed in the present study
The genome sequence of the biocontrol fungus Metarhizium anisopliae and comparative genomics of Metarhizium species.
Background: Metarhizium anisopliae is an important fungal biocontrol agent of insect pests of agricultural crops. Genomics can aid the successful commercialization of biopesticides by identification of key genes differentiating closely related species, selection of virulent microbial isolates which are amenable to industrial scale production and formulation and through the reduction of phenotypic variability. The genome of Metarhizium isolate ARSEF23 was recently published as a model for M. anisopliae, however phylogenetic analysis has since re-classified this isolate as M. robertsii. We present a new annotated genome sequence of M. anisopliae (isolate Ma69) and whole genome comparison to M. robertsii (ARSEF23) and M. acridum (CQMa 102).Results: Whole genome analysis of M. anisopliae indicates significant macrosynteny with M. robertsii but with some large genomic inversions. In comparison to M. acridum, the genome of M. anisopliae shares lower sequence homology. While alignments overall are co-linear, the genome of M. acridum is not contiguous enough to conclusively observe macrosynteny. Mating type gene analysis revealed both MAT1-1 and MAT1-2 genes present in M. anisopliae suggesting putative homothallism, despite having no known teleomorph, in contrast with the putatively heterothallic M. acridum isolate CQMa 102 (MAT1-2) and M. robertsii isolate ARSEF23 (altered MAT1-1). Repetitive DNA and RIP analysis revealed M. acridum to have twice the repetitive content of the other two species and M. anisopliae to be five times more RIP affected than M. robertsii. We also present an initial bioinformatic survey of candidate pathogenicity genes in M. anisopliae.Conclusions: The annotated genome of M. anisopliae is an important resource for the identification of virulence genes specific to M. anisopliae and development of species- and strain- specific assays. New insight into the possibility of homothallism and RIP affectedness has important implications for the development of M. anisopliae as a biopesticide as it may indicate the potential for greater inherent diversity in this species than the other species. This could present opportunities to select isolates with unique combinations of pathogenicity factors, or it may point to instability in the species, a negative attribute in a biopesticide
Machine-checking the universal verifiability of ElectionGuard
ElectionGuard is an open source set of software components and specifications from Microsoft designed to allow the modification of a number of different e-voting protocols and products to produce public evidence (transcripts) which anyone can verify. The software uses ElGamal, homomorphic tallying and sigma protocols to enable public scrutiny without adversely affecting privacy. Some components have been formally verified (machine-checked) to be free of certain software bugs but there was no formal verification of their cryptographic security.
Here, we present a machine-checked proof of the verifiability guarantees of the transcripts produced and verified according to the ElectionGuard specification. We have also extracted an executable version of the verifier specification, which we proved to be secure, and used it to verify election transcripts produced by ElectionGuard. Our results show that our implementation is of similar efficiency to existing implementations
Models of spatiotemporal variation in rabbit abundance reveal management hot spots for an invasive species
First published: 25 January 2020The European rabbit (Oryctolagus cuniculus) is a notorious economic and environmental pest species in its invasive range. To better understand the population and range dynamics of this species, 41 years of abundance data have been collected from 116 unique sites across a broad range of climatic and environmental conditions in Australia. We analyzed this time series of abundance data to determine whether inter‐annual variation in climatic conditions can be used to map historic, contemporary, and potential future fluctuations in rabbit abundance from regional to continental scales. We constructed a hierarchical Bayesian regression model of relative abundance that corrected for observation error and seasonal biases. The corrected abundances were regressed against environmental and disease variables in order to project high spatiotemporal resolution, continent‐wide rabbit abundances. We show that rabbit abundance in Australia is highly variable in space and time, being driven primarily by inter‐annual variation in temperature and precipitation in concert with the prevalence of a non‐pathogenic virus. Moreover, we show that inter‐annual variation in local spatial abundances can be mapped effectively at a continental scale using highly resolved spatiotemporal predictors, allowing “hotspots” of persistently high rabbit abundance to be identified. Importantly, cross‐validated model performance was fair to excellent within and across distinct climate zones. Long‐term monitoring data for invasive species can be used to map fine‐scale spatiotemporal fluctuations in abundance patterns when accurately accounting for inherent sampling biases. Our analysis provides ecologists and pest managers with a clearer understanding of the determinants of rabbit abundance in Australia, offering an important new approach for predicting spatial abundance patterns of invasive species at the near‐term temporal scales that are directly relevant to resource management.Stuart C Brown, Konstans Wells, Emilie Roy-Dufresne, Susan Campbell, Brian Cooke, Tarnya Cox, Damien A. Fordha
The genome sequence of the biocontrol fungus Metarhizium anisopliae and comparative genomics of Metarhizium species
Metarhizium anisopliae is an important fungal biocontrol agent of insect pests of agricultural crops. Genomics can aid the successful commercialization of biopesticides by identification of key genes differentiating closely related species, selection of virulent microbial isolates which are amenable to industrial scale production and formulation and through the reduction of phenotypic variability. The genome of Metarhizium isolate ARSEF23 was recently published as a model for M. anisopliae, however phylogenetic analysis has since re-classified this isolate as M. robertsii. We present a new annotated genome sequence of M. anisopliae (isolate Ma69) and whole genome comparison to M. robertsii (ARSEF23) and M. acridum (CQMa 102)
Creation and Validation of the Spanish Durum Wheat Core Collection.
Spanish wheat (Triticum spp.) landraces have a considerable polymorphism, containing many unique alleles, relative to other collections. The existence of a core collection is a favored approach for breeders to efficiently explore novel variation and enhance the use of germplasm. In this study, the Spanish durum wheat (Triticum turgidum L.) core collection (CC) was created using a population structure–based method, grouping accessions by subspecies and allocating the number of genotypes among populations according to the diversity of simple sequence repeat (SSR) markers. The CC of 94 genotypes was established, which accounted for 17% of the accessions in the entire collection. An alternative core collection (CH), with the same number of genotypes per subspecies and maximizing the coverage of SSR alleles, was assembled with the Core Hunter software. The quality of both core collections was compared with a random core collection and evaluated using geographic, agromorphological, and molecular marker data not previously used in the selection of genotypes. Both core collections had a high genetic representativeness, which validated their sampling strategies. Geographic and agromorphological variation, phenotypic correlations, and gliadin alleles of the original collection were more accurately depicted by the CC. Diversity arrays technology (DArT) markers revealed that the CC included genotypes less similar than the CH. Although more SSR alleles were retained by the CH (94%) than by the CC (91%), the results showed that the CC was better than CH for breeding purposes
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