11 research outputs found
The “Little White Lie:” An Exercise to Explore the Relevance of Diversity Curriculum
Compared to the previous decade, fewer incoming college students see racism as a major problem in America (Sax et al. 2001). While there are many complex variables that contribute to persistent racism, we argue that forms of both overt and covert racism are in part perpetuated by our language. This paper offers a concrete example of how educators in business schools in Jesuit institutions of higher education can infuse justice/social responsibility into our curricula (Spitzer 2010). The classroom activity, as described, is designed for a traditional face-to-face undergraduate classroom. Grounded in the principles of Ignatian pedagogy, this exercise provides a practical tool to contextualize the power of language of today’s Millennial college student, surfacing the connotations of power and privilege, while supporting student experience, reflection, and action
Spatiotemporal assessment of airborne pollen in the urban environment: The pollenscape of Thessaloniki as a case study.
Pollen is indispensable for life. But, as it may trigger allergic reactions, it can become a biological pollutant, thus requiring monitoring. In urban ecosystems, this is usually done with sampling at rooftop level; exposure to allergenic pollen at ground level is largely unknown. Using the Hirst-type methodology, we explore here how the qualitative, quantitative and phenological features of airborne pollen change horizontally, in different sites of the urban environment, and vertically, when pollen sources are primarily local. We sampled for two years in Thessaloniki, Greece, at six near-ground stations (at 1.5 m) and one at rooftop-level (30 m high). There was a large variability in quantitative pollen features among stations, but Urticaceae, Cupressaceae, Platanus, Pinaceae, and Quercus were the five most abundantly represented taxa in the air, both near the ground and at rooftop level, exceeding there an annual pollen integral of 1000 grains m−3. We found height to have a clear effect on pollen concentration: near the ground, it was three times higher for the entire pollen spectrum and up to 11 times higher for individual taxa. Assuming an exponential decay of pollen with distance from the ground, we calculated pollen concentration for the entire spectrum to decline to half the near-ground value every 19 m and at higher rates for individual taxa. Pollen season also varied largely among stations; a semi-natural station, next to a peri-urban forest, differed from the purely urban stations in having higher pollen concentration and shorter pollen season. For only two taxa, Urticaceae and Cupressaceae, pollen concentrations exceeded thresholds associated with high risk for more than 5% of the year. We conclude that pollen is far from homogeneously distributed within the urban environment, and that height has a strong effect on the low-altitude vertical profile of pollen. At an applied level, this study provides necessary information for more efficient monitoring of airborne pollen and for designing and managing urban green spaces, particularly under the current climate change and the associated higher demand for urban green
Imprinting statistically sound conclusions for gut microbiota in comparative animal studies: A case study with diet and teleost fishes
Despite the technical progress in high-throughput sequencing technologies, defining the sample size which is capable of yielding representative inferences in metabarcoding analysis still remains debatable. The present study addresses the influence of individual variability in assessing dietary effects on fish gut microbiota parameters and estimates the biological sample size that is sufficient to imprint a statistically secure outcome. European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) were fed three alternative animal protein diets and a fishmeal control diet. Gut microbiota data from 12 individuals per diet, derived from Illumina sequencing of the V3–V4 region of the 16S rRNA gene, were randomized in all possible combinations of n-1 individuals. Results in this study showcased that increasing the sample size can limit the prevalence of individuals with high microbial load on the outcome and can ensure the statistical confidence required for an accurate validation of dietary-induced microbe shifts. Inter-individual variability was evident in the four dietary treatments where consequently misleading inferences arose from insufficient biological replication. These findings have critical implications for the design of future metabarcoding studies and highlight the urgency in selecting an adequate sample size able to safely elucidate the dietary effects on fish gut microbial communities. © 2020 Elsevier Inc
Configuration of gut microbiota structure and potential functionality in two teleosts under the influence of dietary insect meals
Insect meals are considered promising, eco-friendly, alternative ingredients for aquafeed. Considering the dietary influence on establishment of functioning gut microbiota, the effect of the insect meal diets on the microbial ecology should be addressed. The present study assessed diet-and species-specific shifts in gut resident bacterial communities of juvenile reared Dicentrarchus labrax and Sparus aurata in response to three experimental diets with insect meals from three insects (Hermetia illucens, Tenebrio molitor, Musca domestica), using high-throughput Illumina sequencing of the V3–V4 region of the 16S rRNA gene. The dominant phyla were Firmicutes, Proteobacteria and Actinobacteria in all dietary treatments. Anaerococcus sp., Cutibacterium sp. and Pseudomonas sp. in D. labrax, and Staphylococcus sp., Hafnia sp. and Aeromonas sp. in S. aurata were the most enriched shared species, following insect-meal inclusion. Network analysis of the dietary treatments highlighted diet-induced changes in the microbial community assemblies and revealed unique and shared microbe-to-microbe interactions. PICRUSt-predicted Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly differentiated, including genes associated with metabolic pathways. The present findings strengthen the importance of diet in microbiota configuration and underline that different insects as fish feed ingredients elicit species-specific differential responses of structural and functional dynamics in gut microbial communities. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Plant flowering mirrored in airborne pollen seasons? Evidence from phenological observations in 14 woody taxa
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The effect of natural disturbances on forest biodiversity: an ecological synthesis
Disturbances alter biodiversity via their specific characteristics, including severity and extent in the landscape, which act at different temporal and spatial scales. Biodiversity response to disturbance also depends on the community characteristics and habitat requirements of species. Untangling the mechanistic interplay of these factors has guided disturbance ecology for decades, generating mixed scientific evidence of biodiversity responses to disturbance. Understanding the impact of natural disturbances on biodiversity is increasingly important due to human-induced changes in natural disturbance regimes. In many areas, major natural forest disturbances, such as wildfires, windstorms, and insect outbreaks, are becoming more frequent, intense, severe, and widespread due to climate change and land-use change. Conversely, the suppression of natural disturbances threatens disturbance-dependent biota. Using a meta-analytic approach, we analysed a global data set (with most sampling concentrated in temperate and boreal secondary forests) of species assemblages of 26 taxonomic groups, including plants, animals, and fungi collected from forests affected by wildfires, windstorms, and insect outbreaks. The overall effect of natural disturbances on α-diversity did not differ significantly from zero, but some taxonomic groups responded positively to disturbance, while others tended to respond negatively. Disturbance was beneficial for taxonomic groups preferring conditions associated with open canopies (e.g. hymenopterans and hoverflies), whereas ground-dwelling groups and/or groups typically associated with shady conditions (e.g. epigeic lichens and mycorrhizal fungi) were more likely to be negatively impacted by disturbance. Across all taxonomic groups, the highest α-diversity in disturbed forest patches occurred under moderate disturbance severity, i.e. with approximately 55% of trees killed by disturbance. We further extended our meta-analysis by applying a unified diversity concept based on Hill numbers to estimate α-diversity changes in different taxonomic groups across a gradient of disturbance severity measured at the stand scale and incorporating other disturbance features. We found that disturbance severity negatively affected diversity for Hill number q = 0 but not for q = 1 and q = 2, indicating that diversity-disturbance relationships are shaped by species relative abundances. Our synthesis of α-diversity was extended by a synthesis of disturbance-induced change in species assemblages, and revealed that disturbance changes the β-diversity of multiple taxonomic groups, including some groups that were not affected at the α-diversity level (birds and woody plants). Finally, we used mixed rarefaction/extrapolation to estimate biodiversity change as a function of the proportion of forests that were disturbed, i.e. the disturbance extent measured at the landscape scale. The comparison of intact and naturally disturbed forests revealed that both types of forests provide habitat for unique species assemblages, whereas species diversity in the mixture of disturbed and undisturbed forests peaked at intermediate values of disturbance extent in the simulated landscape. Hence, the relationship between α-diversity and disturbance severity in disturbed forest stands was strikingly similar to the relationship between species richness and disturbance extent in a landscape consisting of both disturbed and undisturbed forest habitats. This result suggests that both moderate disturbance severity and moderate disturbance extent support the highest levels of biodiversity in contemporary forest landscapes