61 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
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 interâannual 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, continentâwide rabbit abundances. We show that rabbit abundance in Australia is highly variable in space and time, being driven primarily by interâannual variation in temperature and precipitation in concert with the prevalence of a nonâpathogenic virus. Moreover, we show that interâannual variation in local spatial abundances can be mapped effectively at a continental scale using highly resolved spatiotemporal predictors, allowing âhotspotsâ of persistently high rabbit abundance to be identified. Importantly, crossâvalidated model performance was fair to excellent within and across distinct climate zones. Longâterm monitoring data for invasive species can be used to map fineâscale 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 nearâterm 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
Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (DArT)
The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 ÎŒg.g -1 , and ranged from 1.06 ÎŒg.g -1 for the triploid Nanica (Cavendish group) to 19.24 ÎŒg.g -1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 ÎŒg.g -1). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank
Beyond Refugia: New insights on Quaternary climate variation and the evolution of biotic diversity in tropical South America
Hafferâs (Science 165: 131â137, 1969) Pleistocene refuge theory has provided motivation for 50 years of investigation into the connections between climate, biome dynamics, and neotropical speciation, although aspects of the orig- inal theory are not supported by subsequent studies. Recent advances in paleocli- matology suggest the need for reevaluating the role of Quaternary climate on evolutionary history in tropical South America. In addition to the many repeated large-amplitude climate changes associated with Pleistocene glacial-interglacial stages (~40 kyr and 100 kyr cyclicity), we highlight two aspects of Quaternary climate change in tropical South America: (1) an east-west precipitation dipole, induced by solar radiation changes associated with Earthâs precessional variations (~20 kyr cyclicity); and (2) periods of anomalously high precipitation that persisted for centuries-to-millennia (return frequencies ~1500 years) congruent with cold âHeinrich eventsâ and cold Dansgaard-Oeschger âstadialsâ of the North Atlantic region. The spatial footprint of precipitation increase due to this North Atlantic forcing extended across almost all of tropical South America south of the equator. Combined, these three climate modes present a picture of climate change with different spatial and temporal patterns than envisioned in the original Pleistocene refuge theory. Responding to these climate changes, biomes expanded and contracted and became respectively connected and disjunct. Biome change undoubtedly influenced biotic diversification, but the nature of diversification likely was more complex than envisioned by the original Pleistocene refuge theory. In the lowlands, intermittent forest expansion and contraction led to species dispersal and subsequent isolation, promoting lineage diversification. These pulses of climate-driven biotic interchange profoundly altered the composition of regional species pools and triggered new evolutionary radiations. In the special case of the tropical Andean forests adjacent to the Amazon lowlands, new phylogenetic data provide abundant evidence for rapid biotic diversification during the Pleistocene. During warm interglacials and intersta- dials, lowland taxa dispersed upslope. Isolation in these disjunct climate refugia led to extinction for some taxa and speciation for others.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155561/1/Baker2020.pdfDescription of Baker2020.pdf : Main articl
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