The threat of state sponsored Cyber attacks in Canada: to serve and protect

This Masters of Global Affairs project has been constructed for the use as a piece contributing to policy recommendations for the Canadian Federal government on their response to handling state-sponsored cyber attacks on critical national infrastructure (CNI) in Canada. Throughout this project an exploration is undertaken to understand the means of attacks that Canada has faced since the millennium, as well as to see what defense and security measures were of use, and what security measures were under-utilized. By exploring these attacks to Canada’s CNI, clarification on improvements for the federal government on its future state of cyber defense become available. This project will also look to shape policy recommendations that can be considered in further national security agenda creation as well as governmental policies affecting domestic, and global governance on cyber attacks

Community assembly by limiting similarity vs. competitive hierarchies: testing the consequences of dispersion of individual traits

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102206/1/jec12181.pd

Field-based effects of allelopathy in invaded tallgrass prairie

Allelopathic phytochemicals have been linked to invasion success, but their role in the invasion process remains unclear. Toxicity effects demonstrated with lab bioassays may be neutralized in soils, and their role in population expansion can be intertwined with nonallelopathic processes that also influence dispersal and establishment. Here, we use greenhouse experiments to test the soil-based impacts of invasive fine fescue (Festuca rubra L.) on recruitment in tallgrass prairie. Fescue roots release the growth inhibitor m-tyrosine. Using root washes and fescue-conditioned soils to mimic field potency, we determined allelopathic impacts on recruitment, including intraspecific limitation. We also tested whether nonallelopathic factors (propagule pressure, disturbance, and fertility) influence invasion into constructed fescue and prairie mesocosms, and whether root washes inhibit arbuscular mycorrhizal (AM) fungi. We observed significant negative effects of fescue soils and root washes on germination and seedling survival, including on fescue itself. Mesocosm invasion, however, was determined more by nonallelopathic mechanisms (propagule pressure and rapid growth). In prairie mesocosms, fescue invasion was higher than its own understory, with no effects of disturbance or fertility. Tallgrass species had difficulty establishing in all environments, regardless of propagule pressure. Impacts on AM fungal hyphal length and spore production were insignificant. Our results suggest that nonallelopathic traits may be sufficient to explain fescue invasion, with allelopathy likely emerging as a final "coup de grâce" for recruiting native grasses once dominance has been attained. Allelopathic species, including fine fescue, may thus not necessarily be invasive unless nonallelopathic traits facilitate establishment prior to the accumulation of soil-based toxins

Nitrogen addition enhances terrestrial phosphorous retention in grassland mesocosms

Nitrogen (N) and phosphorus (P) are fundamental for plant biomass production in grasslands, are often co-limiting, and have become major freshwater pollutants. By factorially applying gradients of N and P to field-based grassland mesocosms, we tested for saturating thresholds of plant uptake as nutrients increase and whether simultaneous and potentially additive growing-season demand reduces flows of dissolved nutrients to subsurface leachate. We quantified the seasonality of nutrient losses, differences in uptake by functional group (grasses, forbs), the impacts of increasing nutrients on root:shoot ratios, and contrasted vegetated and unvegetated treatments to isolate edaphic influences. Overall, most added nutrients were retained by plants and soil–80% for N and 99% for P. Co-limitation dynamics were powerful but asymmetrical with N additions reducing P in leachate, but P having little influence on N. N retention was primarily influenced by season—most N was lost prior to peak biomass when plant demand was presumably lower. Nutrients reduced root:shoot ratios by increasing foliage but with no detectable effect on retention, possible because root biomass remained unchanged. Similarly, there was no impact of functional group on nutrient loss. Despite substantial plant uptake, leachate concentrations of N and P still exceeded regional levels for safe drinking water and prevention of algal blooms. This work reveals how nutrient co-limitation can accelerate the capture of P by N in grasslands, indicating that plant uptake can significantly reduce dissolved subsurface nutrients. However, the offseason flows of N and the failure to meet regional water-quality standards despite capture levels as high as 99% reveal that vegetative-based solutions to nutrient capture by grasslands are important but likely insufficient without complimentary measures that reduce inputs

Evaluation of the University of Victoria Earth System Climate Model version 2.10 (UVic ESCM 2.10)

The University of Victoria Earth system climate model of intermediate complexity has been a useful tool in recent assessments of long-term climate changes including paleo-climate modelling. Since the last official release of the UVic ESCM 2.9, and the two official updates during the last decade, a lot of model development has taken place in multiple groups. The new version 2.10 of the University of Victoria Earth System Climate Model (UVic ESCM), to be used in the 6th phase of the coupled model intercomparison project (CMIP6), presented here combines and brings together multiple model developments and new components that have taken place since the last official release of the model. To set the foundation of its use, we here describe the UVic ESCM 2.10 and evaluate results from transient historical simulations against observational data. We find that the UVic ESCM 2.10 is capable of reproducing well changes in historical temperature and carbon fluxes, as well as the spatial distribution of many ocean tracers, including temperature, salinity, phosphate and nitrate. This is connected to a good representation of ocean physical properties. For the moment, there remain biases in ocean alkalinity and dissolved inorganic carbon, which will be addressed in the next updates to the model

Nonswelling thiol-yne crosslinked hydrogel materials as cytocompatible soft tissue scaffolds

A key drawback of hydrogel materials for tissue engineering applications is their characteristic swelling response, which leads to a diminished mechanical performance. However, if a solution can be found to overcome such limitations, there is a wider application for these materials. Herein, we describe a simple and effective way to control the swelling and degradation rate of nucleophilic thiol-yne poly(ethylene glycol) (PEG) hydrogel net- works using two straightforward routes: using multiarm alkyne and thiol terminated PEG precursors or introducing a thermores- ponsive unit into the PEG network while maintaining their robust mechanical properties. In situ hydrogel materials were formed in under 10 min in PBS solution at pH 7.4 without the need for an external catalyst by using easily accessible precursors. Both pathways resulted in strong tunable hydrogel materials (compressive strength values up to 2.4 MPa) which could effectively encapsulate cells, thus highlighting their potential as soft tissue scaffoldsPostprint (published version

Globally, plant-soil feedbacks are weak predictors of plant abundance

Plant-soil feedbacks (PSFs) have been shown to strongly affect plant performance under controlled conditions, and PSFs are thought to have far reaching consequences for plant population dynamics and the structuring of plant communities. However, thus far the relationship between PSF and plant species abundance in the field is not consistent. Here, we synthesize PSF experiments from tropical forests to semiarid grasslands, and test for a positive relationship between plant abundance in the field and PSFs estimated from controlled bioassays. We meta-analyzed results from 22 PSF experiments and found an overall positive correlation (0.12 <= r over bar <= 0.32) between plant abundance in the field and PSFs across plant functional types (herbaceous and woody plants) but also variation by plant functional type. Thus, our analysis provides quantitative support that plant abundance has a general albeit weak positive relationship with PSFs across ecosystems. Overall, our results suggest that harmful soil biota tend to accumulate around and disproportionately impact species that are rare. However, data for the herbaceous species, which are most common in the literature, had no significant abundance-PSFs relationship. Therefore, we conclude that further work is needed within and across biomes, succession stages and plant types, both under controlled and field conditions, while separating PSF effects from other drivers (e.g., herbivory, competition, disturbance) of plant abundance to tease apart the role of soil biota in causing patterns of plant rarity versus commonness

Environmental heterogeneity modulates the effect of plant diversity on the spatial variability of grassland biomass

Plant productivity varies due to environmental heterogeneity, and theory suggests that plant diversity can reduce this variation. While there is strong evidence of diversity effects on temporal variability of productivity, whether this mechanism extends to variability across space remains elusive. Here we determine the relationship between plant diversity and spatial variability of productivity in 83 grasslands, and quantify the effect of experimentally increased spatial heterogeneity in environmental conditions on this relationship. We found that communities with higher plant species richness (alpha and gamma diversity) have lower spatial variability of productivity as reduced abundance of some species can be compensated for by increased abundance of other species. In contrast, high species dissimilarity among local communities (beta diversity) is positively associated with spatial variability of productivity, suggesting that changes in species composition can scale up to affect productivity. Experimentally increased spatial environmental heterogeneity weakens the effect of plant alpha and gamma diversity, and reveals that beta diversity can simultaneously decrease and increase spatial variability of productivity. Our findings unveil the generality of the diversity-stability theory across space, and suggest that reduced local diversity and biotic homogenization can affect the spatial reliability of key ecosystem functions.EEA Santa CruzFil: Daleo, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Marinas y Costeras (IIMyC); Argentina.Fil: Alberti, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Marinas y Costeras (IIMyC); Argentina.Fil: Chaneton, Enrique J. Universidad de Buenos Aires. Facultad de Agronomía; Argentina.Fil: Chaneton, Enrique J. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA); Argentina.Fil: Iribarne, Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Marinas y Costeras (IIMyC); Argentina.Fil: Tognetti, Pedro M. Universidad de Buenos Aires. Facultad de Agronomía; Argentina.Fil: Tognetti, Pedro M. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA); Argentina.Fil: Bakker, Jonathan D. University of Washington. School of Environmental and Forest Sciences; Estados UnidosFil: Borer, Elizabeth T. University of Minnesota. Department of Ecology, Evolution & Behavior; Estados UnidosFil: Bruschetti, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Marinas y Costeras (IIMyC); Argentina.Fil: MacDougall, Andrew S. University of Guelph.Department of Integrative Biology; CanadáFil: Pascual, Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Marinas y Costeras (IIMyC); Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Hautier, Yann. Utrecht University. Department of Biology. Ecology and Biodiversity Group; Países Bajo

The Zero Emissions Commitment Model Intercomparison Project (ZECMIP) contribution to C4MIP: Quantifying committed climate changes following zero carbon emissions

The amount of additional future temperature change following a complete cessation of CO2 emissions is a measure of the unrealized warming to which we are committed due to CO2 already emitted to the atmosphere. This “zero emissions commitment” (ZEC) is also an important quantity when estimating the remaining carbon budget – a limit on the total amount of CO2 emissions consistent with limiting global mean temperature at a particular level. In the recent IPCC Special Report on Global Warming of 1.5 ∘C, the carbon budget framework used to calculate the remaining carbon budget for 1.5 ∘C included the assumption that the ZEC due to CO2 emissions is negligible and close to zero. Previous research has shown significant uncertainty even in the sign of the ZEC. To close this knowledge gap, we propose the Zero Emissions Commitment Model Intercomparison Project (ZECMIP), which will quantify the amount of unrealized temperature change that occurs after CO2 emissions cease and investigate the geophysical drivers behind this climate response. Quantitative information on ZEC is a key gap in our knowledge, and one that will not be addressed by currently planned CMIP6 simulations, yet it is crucial for verifying whether carbon budgets need to be adjusted to account for any unrealized temperature change resulting from past CO2 emissions. We request only one top-priority simulation from comprehensive general circulation Earth system models (ESMs) and Earth system models of intermediate complexity (EMICs) – a branch from the 1 % CO2 run with CO2 emissions set to zero at the point of 1000 PgC of total CO2 emissions in the simulation – with the possibility for additional simulations, if resources allow. ZECMIP is part of CMIP6, under joint sponsorship by C4MIP and CDRMIP, with associated experiment names to enable data submissions to the Earth System Grid Federation. All data will be published and made freely available