Mitigating impacts of climate change in stream food webs

AbstractUnderstanding the effects of changing climates on the processes which support aquatic biodiversity is of critical importance for managing aquatic ecosystems. This research used an experimental approach to determine whether there are potential ecological surprises in terms of threshold relationships between climate and critical aquatic processes. These results were then placed in the context of the potential for riparian replanting to mitigate against these impacts.A review was carried out of climate change experiments in freshwaters, and revealed that the vast majority of studies have failed to take into account predicted increases in the frequency of extreme events (such as heatwaves) on biota. In order to include these components of changes in climate, a methodology was developed for downscaling global circulation models of climate change to generate realistic temperature data to use as an experimental treatment. Stream communities from the field were brought into experimental flumes and warmed according to the predictions of the down-scaled climate change models. Experiments were run for six weeks and responses were measured for basal processes (algal productivity and carbon dynamics) and aquatic invertebrate communities. Basal processes showed relatively small responses to the changed temperature regime, and appear to be relatively resistant for warming on the scale predicted under climate change scenarios for the next century. Aquatic invertebrate communities did show some responses, but these tended to be in terms of changes in size structure withion particular taxa rather than major impacts on patterns of biodiversity.The largest effects were seen for emerging adults of aquatic insects, were all species in the community responded in some way to our 2100 climate change treatment. Responses were species- and sex-specific. Males of all mayfly species emerged faster under 2100 temperatures compared to 1990-2000 temperatures. For the mayfly Ulmerophlebia pipinna (Leptophlebiidae), this implied a change in the sex ratio that could potentially compromise populations and, ultimately, lead to local extinctions. Furthermore, our results show a decrease in the overall community body size (average across taxa) due to a shift from bigger to smaller species.These results are in accord with the ecological rules dealing with the temperature-size relationships (in particular, Bergmann’s rule). Studies of streams in the field revealed that riparian vegetation did cool stream temperatures, and that the presence of riparian vegetation, ideally with extensive vegetation cover across the catchment, did appear to maintain higher diversity and abundance in stream invertebrate communities. Therefore it seems that restoring riparian vegetation does represent an effective means of adaptation to changing climates for temperate south eastern Australian freshwaters.Please cite this report as: Thompson, RM, Beardall, J, Beringer, J, Grace, M, Sardina, P 2013 Mitigating impacts of climate change on stream food webs: impacts of elevated temperature and CO2 on the critical processes underpinning resilience of aquatic ecosystems National Climate Change Adaptation Research Facility, Gold Coast, pp.136.Understanding the effects of changing climates on the processes which support aquatic biodiversity is of critical importance for managing aquatic ecosystems. This research used an experimental approach to determine whether there are potential ecological surprises in terms of threshold relationships between climate and critical aquatic processes. These results were then placed in the context of the potential for riparian replanting to mitigate against these impacts.A review was carried out of climate change experiments in freshwaters, and revealed that the vast majority of studies have failed to take into account predicted increases in the frequency of extreme events (such as heatwaves) on biota. In order to include these components of changes in climate, a methodology was developed for downscaling global circulation models of climate change to generate realistic temperature data to use as an experimental treatment. Stream communities from the field were brought into experimental flumes and warmed according to the predictions of the down-scaled climate change models. Experiments were run for six weeks and responses were measured for basal processes (algal productivity and carbon dynamics) and aquatic invertebrate communities. Basal processes showed relatively small responses to the changed temperature regime, and appear to be relatively resistant for warming on the scale predicted under climate change scenarios for the next century. Aquatic invertebrate communities did show some responses, but these tended to be in terms of changes in size structure withion particular taxa rather than major impacts on patterns of biodiversity.The largest effects were seen for emerging adults of aquatic insects, were all species in the community responded in some way to our 2100 climate change treatment. Responses were species- and sex-specific. Males of all mayfly species emerged faster under 2100 temperatures compared to 1990-2000 temperatures. For the mayfly Ulmerophlebia pipinna (Leptophlebiidae), this implied a change in the sex ratio that could potentially compromise populations and, ultimately, lead to local extinctions. Furthermore, our results show a decrease in the overall community body size (average across taxa) due to a shift from bigger to smaller species.These results are in accord with the ecological rules dealing with the temperature-size relationships (in particular, Bergmann’s rule). Studies of streams in the field revealed that riparian vegetation did cool stream temperatures, and that the presence of riparian vegetation, ideally with extensive vegetation cover across the catchment, did appear to maintain higher diversity and abundance in stream invertebrate communities. Therefore it seems that restoring riparian vegetation does represent an effective means of adaptation to changing climates for temperate south eastern Australian freshwaters

Social Support and Minority Student-Athletes

Interpersonal relationships in the family are important to individuals, especially college students. A subgroup within the larger population of college students that calls for further examination is ethnic minority college student-athletes. The present study involved examining ethnic minority college student-athletes’ perceptions of social support they receive from their family as they attend a Predominantly White Institution (PWI). Findings indicated that student- athletes perceived various types of social support that they found beneficial to them both as student-athletes in general and as minority student-athletes in particular. Types of social support included emotional support, informational support, tangible assistance support, task appreciation support, and esteem support. Participants also offered advice to families for providing social support to student-athletes while in college. Practical applications of the findings, along with directions for future research are also discussed

A handbook for reconstructing 16th century Lutheran masses

A Handbook for Reconstructing 16th Century Lutheran Masses walks the reader through the process of creating a Mass as it might have been celebrated in the first century of Lutheranism in Germany. The handbook helps the reader navigate primary sources including church orders, chant books, and hymnals from the period. It also includes a summary of where to find chants for each part of the Mass and two case studies and appendixes showing hymn and chant assignments for the Mass as found in the primary sources

Queerness in French Baroque Opera: The Relationship Between Achilles and Patroclus in Jean Baptiste Lully’s Achille et Polyxène

The myth of Achilles has long been considered a narrative model for homosexual relationships. Jean-Baptiste Lully set the story of Achilles and Patroclus to music in the first act of his last opera, Achille et Polyxène. In 17th-century France, various queer men held positions of significant influence, including members of the royal family, such as Louis XIII and Philippe of Orléans. Another powerful queer man was Louis Joseph de Bourbon, the duc de Vendôme who was part of an influential group of libertines. Lully entered the service of the duc in 1685, when he was banished from court after he was caught in an affair with another man, Brunet. In Vendôme’s service, Lully collaborated with Jean Galbert de Campistron, a dramatist and the secretary to Vendôme, to write two operas. Achille et Polyxène was the second of these operas and the last Lully would work on. In the opera’s first act, Campistron’s text and Lully’s music work together to imply a romantic relationship between Achilles and Patroclus, which has been used to portray homosexuality since ancient Greece

How the Supreme Court\u27s Ruling in Endrew v. Douglas Will Affect Special Education

How the Supreme Court\u27s Ruling in Endrew v. Douglas Will Affect Special Educatio

BIMA N2H+ 1-0 mapping observations of L183 -- fragmentation and spin-up in a collapsing, magnetized, rotating, pre-stellar core

We have used the Berkeley-Illinois-Maryland Array (BIMA) to make deep N2H+ 1-0 maps of the pre-stellar core L183, in order to study the spatial and kinematic substructure within the densest part of the core. Three spatially and kinematically distinct clumps are detected, which we label L183-N1, L183-N2 and L183-N3. L183-N2 is approximately coincident with the submillimetre dust peak and lies at the systemic velocity of L183. Thus we conclude that L183-N2 is the central dense core of L183. L183-N1 and 3 are newly-discovered fragments of L183, which are marked by velocity gradients that are parallel to, but far stronger than, the velocity gradient of L183 as a whole, as detected in previous single-dish data. Furthermore, the ratio of the large-scale and small-scale velocity gradients, and the ratio of their respective size-scales, are consistent with the conservation of angular momentum for a rotating, collapsing core undergoing spin-up. The inferred axis of rotation is parallel to the magnetic field direction, which is offset from its long axis, as we have seen in other pre-stellar cores. Therefore, we propose that we have detected a fragmenting, collapsing, filamentary, pre-stellar core, rotating about its B-field, which is spinning up as it collapses. It will presumably go on to form a multiple protostellar system.Comment: 7 figures, 1 table, 21 pages, accepted for publication in Ap

Microbead-Based Biosensing in Microfluidic Devices

Microbeads are frequently used as a solid support to capture target analytes of interest, such as proteins and nucleic acids, from a biological sample. The integration of microbeads into microfluidic systems for biological testing is an area of growing interest. Such lab-on-chip systems are designed to integrate several functions of a conventional laboratory onto a single chip. As a platform to capture targets, beads offer several advantages over planar surfaces such as large surface areas to support biological interactions (increasing sensitivity), the availability of libraries of beads of various types from many vendors, and array-based formats capable of detecting multiple targets simultaneously (multiplexing). This dissertation describes the development and characterization of microbead-based biosensing devices. A customized hot embossing technique was used to stamp an array of microwells in a thin plastic substrate where appropriately functionalized agarose microbeads were selectively placed within a conduit. Functionalized quantum dot nanoparticles were pumped through the conduit and used as a fluorescent label to monitor binding to the bead. Three-dimensional finite element simulations were carried out to model the mass transfer and binding kinetics on the beads’ surfaces and within the porous beads. The theoretical predictions were critically compared and favorably agreed with experimental observations. A novel method of bead pulsation was shown to improve binding kinetics in porous beads. In addition, the dissertation discusses other types of bead arrays and demonstrates alternative bead-based target capture and detection strategies. This work enhances our understanding of bead-based microfluidic systems and provides a design and optimization tool for developers of point-of-care, lab-on-chip devices for medical diagnosis, food and water quality inspection, and environmental monitoring