Benthic Algae of Lake Erie (1865-2006): A Review of Assemblage Composition, Ecology, and Causes and Consequences of Changing Abundance

Peer-reviewed literature and published reports were used to summarize knowledge of benthic algal assemblage composition and ecology in Lake Erie, and causes and consequences of temporal variation in algal abundance. Macroalgal assemblages in rocky littoral and soft substrate habitats have been reasonably well described and studied, as has the epiphyte/metaphyte assemblage associated with rocky littoral macroalgae. In contrast, little information exists for non-epiphytic microalgae in littoral habitat. During the period when algal records were reported (1865-2006), the rocky littoral macroalgal assemblage was often dominated by the chlorophyte genera Cladophora and Ulothrix and the rhodophyte Bangia, whereas the charophytes Chara and Nitella were most abundant in littoral soft substrate. In addition to substrate effects, assemblage composition varied as a function of depth, temperature, light levels, and nutrient concentrations. Under certain conditions, macroalgal taxa appeared to outcompete and exclude other taxa from littoral habitat. However, these organisms have also facilitated increased algal diversity by supporting epiphytes/metaphytes. In Lake Erie, significant temporal change in benthic algal abundance has been associated with: 1) eutrophication (prior to 1972), 2) oligotrophication following the Great Lakes Water Quality Agreement (1972-1985), and 3) invasion by Dreissena mussels (1986-2006). Increasingly eutrophic conditions were reflected by high abundance and frequent shoreline fouling by Cladophora, declining charophyte (such as Chara, Nitella) abundance, and invasion of rocky littoral habitat by euryhaline Bangia. Subsequent indicators of oligotrophication included declining Cladophora abundance, and increased diatom abundance in deepwater habitat. Effects of filter-feeding Dreissena (such as increased water clarity, phosphorus excretion) were likely causes for Cladophora resurgence in the 1990s, and likely contributed to return of Chara and Nitella to formerly occupied habitat. Algal assemblages clearly reflect environmental conditions in aquatic ecosystems. To accurately assess present and future conditions in Lake Erie, continued study of all benthic assemblages is recommended, with greater attention directed toward microalgae in littoral habitat than has occurred in the past

Benthic Algae of Lake Erie (1865-2006): A Review of Assemblage Composition, Ecology, and Causes and Consequences of Changing Abundance

Author Institution: Department of Natural Resource Ecology and Management, Iowa State UniversityAuthor Institution: Department of Biological Sciences, Bowling Green State UniversityPeer-reviewed literature and published reports were used to summarize knowledge of benthic algal assemblage composition and ecology in Lake Erie, and causes and consequences of temporal variation in algal abundance. Macroalgal assemblages in rocky littoral and soft substrate habitats have been reasonably well described and studied, as has the epiphyte/metaphyte assemblage associated with rocky littoral macroalgae. In contrast, little information exists for non-epiphytic microalgae in littoral habitat. During the period when algal records were reported (1865-2006), the rocky littoral macroalgal assemblage was often dominated by the chlorophyte genera Cladophora and Ulothrix and the rhodophyte Bangia, whereas the charophytes Chara and Nitella were most abundant in littoral soft substrate. In addition to substrate effects, assemblage composition varied as a function of depth, temperature, light levels, and nutrient concentrations. Under certain conditions, macroalgal taxa appeared to outcompete and exclude other taxa from littoral habitat. However, these organisms have also facilitated increased algal diversity by supporting epiphytes/metaphytes. In Lake Erie, significant temporal change in benthic algal abundance has been associated with: 1) eutrophication (prior to 1972), 2) oligotrophication following the Great Lakes Water Quality Agreement (1972-1985), and 3) invasion by Dreissena mussels (1986-2006). Increasingly eutrophic conditions were reflected by high abundance and frequent shoreline fouling by Cladophora, declining charophyte (such as Chara, Nitella) abundance, and invasion of rocky littoral habitat by euryhaline Bangia. Subsequent indicators of oligotrophication included declining Cladophora abundance, and increased diatom abundance in deepwater habitat. Effects of filter-feeding Dreissena (such as increased water clarity, phosphorus excretion) were likely causes for Cladophora resurgence in the 1990s, and likely contributed to return of Chara and Nitella to formerly occupied habitat. Algal assemblages clearly reflect environmental conditions in aquatic ecosystems. To accurately assess present and future conditions in Lake Erie, continued study of all benthic assemblages is recommended, with greater attention directed toward microalgae in littoral habitat than has occurred in the past

Kissing Bug

Illustration of man running while holding suitcase; Man carrying gun and dragging woman in pursuit of man in suithttps://scholarsjunction.msstate.edu/cht-sheet-music/7729/thumbnail.jp

The genetic architecture underlying prey-dependent performance in a microbial predator

Natural selection should favour generalist predators that outperform specialists across all prey types. Two genetic solutions could explain why intraspecific variation in predatory performance is, nonetheless, widespread: mutations beneficial on one prey type are costly on another (antagonistic pleiotropy), or mutational effects are prey-specific, which weakens selection, allowing variation to persist (relaxed selection). To understand the relative importance of these alternatives, we characterised natural variation in predatory performance in the microbial predator Dictyostelium discoideum. We found widespread nontransitive differences among strains in predatory success across different bacterial prey, which can facilitate stain coexistence in multi-prey environments. To understand the genetic basis, we developed methods for high throughput experimental evolution on different prey (REMI-seq). Most mutations (~77%) had prey-specific effects, with very few (~4%) showing antagonistic pleiotropy. This highlights the potential for prey-specific effects to dilute selection, which would inhibit the purging of variation and prevent the emergence of an optimal generalist predator

How does climate change impact berry fruit quality?

Berry fruits consumption has increased dramatically over the last decade due to its remarkable flavor and well-known health benefits. The demand for high-quality berry fruits and sustainable production methods is increasing globally, challenging breeders to develop modern berry cultivars that fulfill all desired characteristics. Nowadays, to improve fruits sensorial and nutritive characteristics as well as enhanced fruit quality traits and climate change adaptation are the main objectives of breeding programs. Our aim is the identification of metabolic biomarkers associated with climate change, involved in fruit quality by using metabolomic tools. In addition, multivariate statistical analyses were applied to outline the genetic and environmental factors controlling the accumulation of quality-related metabolites, both for the organoleptic and nutritional characteristics of this highly appreciated fruit. To better understand how environment influence fruit metabolome, we study the metabolomic profiles of mature fruit from four raspberry and black currant commercial cultivars grown in different European locations (Germany, Poland, Norway and Scotland). Our result suggests that environment has a strong impact on primary metabolites and volatiles, such us increase in β-ionone due to high radiation in raspberry fruit or vitamin C accumulation according to differences between day and night temperatures in black currant fruits. Besides, both cultivars appear to be better adapted to North Europe growing conditions, for example they favor the accumulation of SSC and organic acids. Further, we corroborate the impact of environmental factors have on fruit flavor and nutritional value and how metabolomic approaches are suitable for assessing fruit quality.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Mutant resources for functional genomics in Dictyostelium discoideum using REMI-seq technology

Background Genomes can be sequenced with relative ease, but ascribing gene function remains a major challenge. Genetically tractable model systems are crucial to meet this challenge. One powerful model is the social amoeba Dictyostelium discoideum, a eukaryotic microbe widely used to study diverse questions in the cell, developmental and evolutionary biology. Results We describe REMI-seq, an adaptation of Tn-seq, which allows high throughput, en masse, and quantitative identification of the genomic site of insertion of a drug resistance marker after restriction enzyme-mediated integration. We use REMI-seq to develop tools which greatly enhance the efficiency with which the sequence, transcriptome or proteome variation can be linked to phenotype in D. discoideum. These comprise (1) a near genome-wide resource of individual mutants and (2) a defined pool of ‘barcoded’ mutants to allow large-scale parallel phenotypic analyses. These resources are freely available and easily accessible through the REMI-seq website that also provides comprehensive guidance and pipelines for data analysis. We demonstrate that integrating these resources allows novel regulators of cell migration, phagocytosis and macropinocytosis to be rapidly identified. Conclusions We present methods and resources, generated using REMI-seq, for high throughput gene function analysis in a key model system

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure