Plant–Soil Feedback Effects Altered by Aboveground Herbivory Explain Plant Species Abundance in the Landscape

Relatively little is known about how plant–soil feedbacks (PSFs) may affect plant growth in field conditions where factors such as herbivory may be important. Using a potted experiment in a grassland, we measured PSFs with and without aboveground insect herbivory for 20 plant species. We then compared PSF values to plant landscape abundance. Aboveground herbivory had a large negative effect on PSF values. For 15 of 20 species, PSFs were more negative with herbivory than without. This occurred because plant biomass on “home” soils was smaller with herbivory than without. PSF values with herbivory were correlated with plant landscape abundance, whereas PSF values without herbivory were not. Shoot nitrogen concentrations suggested that plants create soils that increase nitrogen uptake, but that greater shoot nitrogen values increase herbivory and that the net effect of positive PSF and greater aboveground herbivory is less aboveground biomass. Results provided clear evidence that PSFs alone have limited power in explaining species abundances and that herbivory has stronger effects on plant biomass and growth on the landscape. Our results provide a potential explanation for observed differences between greenhouse and field PSF experiments and suggest that PSF experiments need to consider important biotic interactions, like aboveground herbivory, particularly when the goal of PSF research is to understand plant growth in field conditions

Light-induced changes in fatty acid profiles of specific lipid classes in several freshwater phytoplankton species

We tested the influence of two light intensities [40 and 300 µmol PAR / (m² s)] on the fatty acid composition of three distinct lipid classes in four freshwater phytoplankton species. We chose species of different taxonomic classes in order to detect potentially similar reaction characteristics that might also be present in natural phytoplankton communities. From samples of the bacillariophyte Asterionella formosa, the chrysophyte Chromulina sp., the cryptophyte Cryptomonas ovata and the zygnematophyte Cosmarium botrytis we first separated glycolipids (monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol), phospholipids (phosphatidylcholine, phosphatidylethanol-amine, phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine) as well as non-polar lipids (triacylglycerols), before analyzing the fatty acid composition of each lipid class. High variation in the fatty acid composition existed among different species. Individual fatty acid compositions differed in their reaction to changing light intensities in the four species. Although no generalizations could be made for species across taxonomic classes, individual species showed clear but small responses in their ecologically-relevant omega-3 and omega-6 polyunsaturated fatty acids in terms of proportions and of per carbon quotas. Knowledge on how lipids like fatty acids change with environmental or culture conditions is of great interest in ecological food web studies, aquaculture and biotechnology, since algal lipids are the most important sources of omega-3 long-chain polyunsaturated fatty acids for aquatic and terrestrial consumers, including human

D-Terms, Unification, and the Higgs Mass

We study gauge extensions of the MSSM that contain non-decoupling D-terms, which contribute to the Higgs boson mass. These models naturally maintain gauge coupling unification and raise the Higgs mass without fine-tuning. Unification constrains the structure of the gauge extensions, limiting the Higgs mass in these models to roughly less than 150 GeV. The D-terms contribute to the Higgs mass only if the extended gauge symmetry is broken at energies of a few TeV, leading to new heavy gauge bosons in this mass range.Comment: 30+1 pages, 7 figure

Unhiding the audiovisual past at Columbia University Libraries

As part of a larger hidden collections initiative, Columbia University Libraries initiated plans in 2018 to digitize their unique audiovisual holdings over seven years. In order to meet an ambitious target within a limited timeframe, staff across divisions and departments had to collaboratively develop shared workflows and efficiencies to maximize output while ensuring a high level of quality. Due to the unique challenges of working with audio and video collections, this collaborative effort was truly unprecedented in the history of Columbia Libraries. This project represented an excellent opportunity to test new functionalities of our locally developed digital asset management system Hyacinth and find robust methods to improve digital curation and preservation using tools like Archivematica digital preservation system. The scope of the project required that we develop efficiencies in our cataloging and metadata enhancement workflows including task automation in OpenRefine, sync metadata between systems including our Voyager ILS and Hyacinth, and plan for new initiatives such as the implementation of a rights management module and integration of crosswalks to ArchivesSpace. One additional outcome of the project’s first year is a deeper analysis of project statistics and workflows using project management methods to inform the future development and planning of the project for years 2-7. This presentation will examine the development of these shared workflows across curatorial, preservation, metadata, and digital technology units, challenges overcome, and lessons learned

Cinematic virtual reality for anxiety management in mechanically ventilated patients: a feasibility and pilot study

Background Mechanically ventilated patients experience anxiety for many reasons. Pharmacological treatments such as benzodiazepines are commonly employed to manage anxiety; however, these therapies often cause undesired side effects. Additional therapies for anxiety management are needed. We sought to determine whether cell phone-based virtual reality therapy could feasibly be used for anxiety management in mechanically ventilated patients. Methods Mechanically ventilated subjects underwent at least one session of virtual reality therapy in which they were shown a cinematic video of an outdoor green space or blue space with 360° visual range of motion. Goal session duration was 5 minutes. The primary outcome was incidence of predefined patient safety events, including self-extubation and accidental removal of tubes or lines. Results Ten subjects underwent a total of 18 virtual reality sessions. Fifteen sessions lasted the planned 5 minutes, one session was extended at participant request, and two sessions were terminated early at participant request. There were no occurrences of the predefined safety events, and no occurrences of cybersickness. Use of a visual analog scale to measure anxiety level was feasible for this pilot study, demonstrating feasibility of this scale for future, larger scale studies. Conclusions Virtual reality therapy shows potential as a means of managing anxiety in patients undergoing mechanical ventilation, and further rigorous exploration with this protocol is feasible

Making Software into a Program: Columbia University Libraries' Hyacinth User Group

This presentation, delivered at the 2019 meeting of the Digital Library Forum, highlights the work of the Hyacinth User Group at Columbia University Libraries. The group has members from many divisions of the library including Application Development, Cataloging, Digital Collections, Institutional Repository and Digital Conversion. These staff members have come together to administer Hyacinth, Columbia’s metadata and content management application. This presentation focuses on two case studies that show the value such an administrative group can bring to the shared use of software - implementing relatedness statements and managing controlled vocabularies. In the case of relatedness statements, the group navigated the varied expressions of relatedness required by different library divisions avoiding collisions and blocks to future development. Shared management of controlled vocabularies has required the group to produce robust documentation and develop clear user permissions to prevent alteration of terms as well as a remediation process for safely removing erroneous terms from the system and records. In the pursuit of these projects, we have seen the vital need for software developers and metadata practitioners to work together. Each has a unique perspective of the problems at hand. The developers have created a powerful tool to organize and publish metadata to numerous websites and digital collections. The Hyacinth User Group has developed the policies and communication flows to ensure the application’s diverse group of users can wield that tool effectively and efficiently

Future Proof: Preserving and Providing Access to Columbia's Audio Visual Collections

As part of a larger hidden collections initiative, in 2018, Columbia University Libraries embarked on a seven year project to digitize their unique audiovisual holdings. In order to meet an ambitious target within a limited timeframe, staff across divisions and departments had to collaboratively develop shared workflows and efficiencies to maximize output while ensuring a high level of quality. Due to the unique challenges of working with analog film/video collections, this collaborative effort was truly unprecedented in the history of Columbia Libraries. This project represented an excellent opportunity to test new functionalities of our locally developed digital asset management system Hyacinth and find robust methods to improve digital curation and preservation using tools like Archivematica digital preservation system. The scope of the project required that we develop efficiencies in our cataloging and metadata enhancement workflows including task automation in OpenRefine, sync both published and unpublished metadata between systems including our Voyager ILS and Hyacinth, and plan for an exponential increase in how digital media collections would be used by both patrons and staff. This presentation will examine the development, implementation, and lessons learned of these cross-departmental workflows as they pertain to the complex landscape of large-scale digital media preservation and access within research libraries

Sex-Specific Differences in Essential Lipid Requirements of Daphnia magna

Sex-specific differences in nutritional requirements may crucially influence the performances of the sexes, which may have implications for sexual reproduction and thus is of great ecological and evolutionary interest. In the freshwater model species Daphnia magna, essential lipid requirements have been extensively studied. Dietary deficiencies in sterols and polyunsaturated fatty acids (PUFA) have been shown to constrain somatic growth and parthenogenetic reproduction of female Daphnia. In contrast, nutrient requirements of male Daphnia have not been studied yet. Supplementation experiments were conducted to investigate differences in sterol (cholesterol) and PUFA (eicosapentaenoic acid, EPA) requirements between female and male D. magna. Thresholds for sterol-limited juvenile growth were higher in females than in males, suggesting that females are more susceptible to dietary sterol deficiencies than males. Sex-specific differences in maximum somatic growth rates were evident primarily in the presence of dietary EPA; females could not exploit their generally higher growth potential in the absence of dietary PUFA. However, the thresholds for EPA-limited growth did not differ between sexes, suggesting that both sexes have similar dietary EPA requirements during juvenile growth. During a life history experiment, the gain in body dry mass was higher in females than in males, irrespective of food treatment. In both sexes, the gain in body dry mass increased significantly upon EPA supplementation, indicating that both sexes benefited from dietary EPA supply also later in life. However, the positive effects of EPA supplementation were most pronounced for female reproduction-related traits (i.e., clutch sizes, egg dry masses, and total dry mass investment in reproduction). The high maternal investment in reproduction resulted in a depletion of nutrients in female somata. In contrast, the comparatively low paternal investment in reproduction allowed for the accumulation of nutrients in male somata. We conclude that males are generally less susceptible to dietary nutrient deficiencies than females, because they can rely more on internal body stores. Our data suggest that the performances of the sexes are differentially influenced by lipid-mediated food quality, which may have consequences for sexual reproduction and thus the production of resting eggs and the maintenance of Daphnia populations

Inelastic quantum transport in superlattices: success and failure of the Boltzmann equation

Electrical transport in semiconductor superlattices is studied within a fully self-consistent quantum transport model based on nonequilibrium Green functions, including phonon and impurity scattering. We compute both the drift velocity-field relation and the momentum distribution function covering the whole field range from linear response to negative differential conductivity. The quantum results are compared with the respective results obtained from a Monte Carlo solution of the Boltzmann equation. Our analysis thus sets the limits of validity for the semiclassical theory in a nonlinear transport situation in the presence of inelastic scattering.Comment: final version with minor changes, to appear in Physical Review Letters, sceduled tentatively for July, 26 (1999

Microengineered Hollow Graphene Tube Systems Generate Conductive Hydrogels with Extremely Low Filler Concentration

The fabrication of electrically conductive hydrogels is challenging as the introduction of an electrically conductive filler often changes mechanical hydrogel matrix properties. Here, we present an approach for the preparation of hydrogel composites with outstanding electrical conductivity at extremely low filler loadings (0.34 S m-1, 0.16 vol %). Exfoliated graphene and polyacrylamide are microengineered to 3D composites such that conductive graphene pathways pervade the hydrogel matrix similar to an artificial nervous system. This makes it possible to combine both the exceptional conductivity of exfoliated graphene and the adaptable mechanical properties of polyacrylamide. The demonstrated approach is highly versatile regarding porosity, filler material, as well as hydrogel system. The important difference to other approaches is that we keep the original properties of the matrix, while ensuring conductivity through graphene-coated microchannels. This novel approach of generating conductive hydrogels is very promising, with particular applications in the fields of bioelectronics and biohybrid robotics