Female site fidelity of the Mealy Mountain caribou herd (Rangifer tarandus caribou) in Labrador

The Mealy Mountain caribou population of southeastern Labrador is listed as threatened. Site fidelity - the philopatric tendency of an animal to remain in or return to the same site - has often been suspected in sedentary caribou like the Mealy Mountain, but rarely has been examined. Philopatric behaviours are important because fidelity sites may then receive priority protection from human disturbance. To describe and document site fidelity for the Mealy Mountain herd, satellite telemetry data from 12 collared adult females during three years was examined. The mean distance between locations in consecutive years of tracking the individual caribou was calculated and an annual profile of site fidelity generated. This profile illustrated that the lowest inter-year distances occurred during calving, when caribou returned to within 39 km (2005-06) and 11.5 km (2006-07) of the previous year's location, and during post-calving, when the mean distance was 7.7 km (2005-06). Spring snow depths were substantially greater in 2007 and appeared to weaken calving site fidelity. This spatial information may serve as a basis for detecting anthropogenic effects on woodland caribou

When and How to Support Renewables?—Letting the Data Speak

Low-carbon energy technologies are pivotal for decarbonising our economies up to 2050 while ensuring secure and affordable energy. Consequently, innovation that reduces the cost of low-carbon energy would play an important role in reducing transition costs. We assess the two most prominent innovation policy instruments (i) public research, development and demonstration (RD&D) subsidies and (ii) public deployment policies. Our results indicate that both deployment and RD&D coincide with increasing knowledge generation and the improved competitiveness of renewable energy technologies. We find that both support schemes together have a greater effect that they would individually, that RD&D support is unsurprisingly more effective in driving patents and that timing matters. Current wind deployment based on past wind RD&D spending coincides best with wind patenting. If we look into competitiveness we find a similar picture, with the greatest effect coming from deployment. Finally, we find significant cross-border effects, especially for winddeployment. Increased deployment in one country coincides with increased patenting in nearby countries. Based on our findings we argue that both deployment and RD&D support are needed to create innovation in renewable energy technologies. However, we worry that current support is unbalanced. Public spending on deployment has been two orders of magnitude larger (in 2010 about €48 billion in the five largest EU countries in 2010) than spending on RD&D support (about €315 million). Consequently, basing the policy mix more on empirical evidence could increase the efficiency of innovation policy targeted towards renewable energy technologies

Population dynamics of reintroduced elk (Cervus elaphus) in eastern North America

Studies that focus on identifying factors that influence reintroduction success have often taken an individual population approach; however, investigating multiple populations can provide additional insight. The overall objective of this research was to emphasize the value of using within- and among-population approaches to identifying factors that influence the population dynamics of a reintroduced species. Elk (Cervus elaphus), a species that was extirpated from eastern North America during the late 1800s, has been reintroduced to portions of its former range over the past century through several initiatives. Today, there are several established populations across eastern regions of the USA and Canada, for which extensive monitoring data are available, creating an opportunity to investigate reintroduction success. I aimed to use these data to identify factors associated with changes in the survival and population growth rates of 10 reintroduced elk populations across eastern North America. More specifically, I: (1) performed a literature review detailing the history of elk reintroduction in eastern North America over the past century, (2) identified factors associated with the variation in population growth rates (reintroduction success) for 10 reintroduced elk populations using an among-population approach, (3) identified and assessed how climate affected the population growth rates of 7 reintroduced elk populations, and (4) investigated direct causes of mortality (predation and train collisions) associated with a single elk population experiencing low population growth. Although the number of successful elk restoration attempts has increased over the past century, there has been substantial variation in population growth rates among reintroductions. Major iv causes of elk mortality in restored populations differed between the pre- to post-acclimation phases of reintroduction. Population growth rates were negatively related to the percentage of coniferous forest within elk population range, suggesting that expansive areas of coniferous forests in eastern North America may represent sub-optimal elk habitat. The Burwash elk population in Ontario had low growth rate compared to most other populations reintroduced into eastern North America. Predation and train collisions were the most important source of mortality for this population. The number of annual elk-train collisions, as well as their locations, were monitored and recorded over 14 years. Collision locations were highly sitespecific and were positively correlated to the proximity of bends in the railway. By relating the number of annual elk-train collisions to various climate factors, I found that collision rates were positively related to snow depth. By analyzing field camera data, I found that elk used the railway mostly during the fall and spring, when elk commonly travel to and from wintering grounds. However, by examining VHF telemetry locations, I determined that elk were closer to the railway in winter than in any other season. Railways likely are perceived by elk as easy travel corridors, especially in the winter, and deep snow might prevent escape from oncoming trains. Black bear (Ursus americanus) and wolves (Canis lupus) were the major predators of elk in the Burwash population. White-tailed deer (Odocoileus virginianus), elk (Cervus elaphus), and moose (Alces alces), were the ungulate prey species available to both predators. To determine if predators prefer one ungulate species over another, and to identify which predator species is likely to have a greater impact on elk survival, I investigated predator diets. To compare rates of v ungulate use by predators in relation to prey availability, I calculated the relative abundance of each ungulate species. I found that wolves used juvenile and adult elk as their primary ungulate prey in greater proportions in comparison to their availability. Bears on the other hand, tended to use all ungulate species in proportion to their availability. Climate is well known to affect ungulate population dynamics; however, several factors (e.g.: density, predator presence), can govern the response. Relating the annual growth rates of 7 elk populations to various climate factors I found that responses were population specific. Increased annual snow fall was associated with declines in population growth rates for 2 of the 7 populations assessed and only 1 population responded negatively to increased summer temperatures. Climate likely interacts with other environmental variables to influence fluctuations in annual population growth rates which warrants further investigation. The results of this research will contribute to informed planning of future elk reintroductions and should support development through improved management. In addition, this research highlights the importance of using within- and among- populations approaches to investigating factors that influence elk reintroduction success.Doctor of Philosophy (Ph.D.) in Boreal Ecolog

Doubly resonant optical nanoantenna arrays for polarization resolved measurements of surface-enhanced Raman scattering

We report that rhomb-shaped metal nanoantenna arrays support multiple plasmonic resonances, making them favorable bio-sensing substrates. Besides the two localized plasmonic dipole modes associated with the two principle axes of the rhombi, the sample supports an additional grating-induced surface plasmon polariton resonance. The plasmonic properties of all modes are carefully studied by far-field measurements together with numerical and analytical calculations. The sample is then applied to surface-enhanced Raman scattering measurements. It is shown to be highly efficient since two plasmonic resonances of the structure were simultaneously tuned to coincide with the excitation and the emission wave- length in the SERS experiment. The analysis is completed by measuring the impact of the polarization angle on the SERS signal.Comment: 13 pages, 5 figure

Bio-IGCC with CCS as a long-term mitigation option in a coupled energy-system and land-use model

This study analyses the impact of techno-economic performance of the BIGCC process and the effect of different biomass feedstocks on the technology's long term deployment in climate change mitigation scenarios. As the BIGCC technology demands high amounts of biomass raw material it also affects the land-use sector and is dependent on conditions and constraints on the land-use side. To represent the interaction of biomass demand and supply side the global energy-economy-climate model ReMIND is linked to the global land-use model MAgPIE. The link integrates biomass demand and price as well as emission prices and land-use emissions. Results indicate that BIGCC with CCS could serve as an important mitigation option and that it could even be the main bioenergy conversion technology sharing 33% of overall mitigation in 2100. The contribution of BIGCC technology to long-term climate change mitigation is much higher if grass is used as fuel instead of wood, provided that the grass-based process is highly efficient. The capture rate has to significantly exceed 60 % otherwise the technology is not applied. The overall primary energy consumption of biomass reacts much more sensitive to price changes of the biomass than to technoeconomic performance of the BIGCC process. As biomass is mainly used with CCS technologies high amounts of carbon are captured ranging from 130 GtC to 240 GtC (cumulated from 2005-2100) in different scenarios

Discrimination between pathogenic and non-pathogenic E. coli strains by means of Raman microspectroscopy

Bacteria can be harmless commensals, beneficial probiotics, or harmful pathogens. Therefore, mankind is challenged to detect and identify bacteria in order to prevent or treat bacterial infections. Examples are identification of species for treatment of infection in clinics and E. coli cell counting for water quality monitoring. Finally, in some instances, the pathogenicity of a species is of interest. The main strategies to investigate pathogenicity are detection of target genes which encode virulence factors. Another strategy could be based on phenotypic identification. Raman spectroscopy is a promising phenotypic method, which offers high sensitivities and specificities for the identification of bacteria species. In this study, we evaluated whether Raman microspectroscopy could be used to determine the pathogenicity of E. coli strains. We used Raman spectra of seven non-pathogenic and seven pathogenic E. coli strains to train a PCA-SVM model. Then, the obtained model was tested by identifying the pathogenicity of three additional E. coli strains. The pathogenicity of these three strains could be correctly identified with a mean sensitivity of 77%, which is suitable for a fast screening of pathogenicity of single bacterial cells. [Figure not available: see fulltext.]. © 2020, The Author(s)

Lithium-to-calcium ratios in Modern, Cenozoic, and Paleozoic articulate brachiopod shells

Li/Ca ratios in modern brachiopod shells generally correlate inversely with growth temperature, ranging from ∼20 µmol/mol at 30°C to ∼50 µmol/mol at 0°C with no apparent interspecific offsets. Causes of the temperature effect on Li/Ca ratios are not yet understood. Cenozoic brachiopod Li/Ca ratios average ∼30 µmol/mol, similar to the average observed in modern brachiopods. Relatively constant Li/Ca ratios for Eocene to Pleistocene nonluminescent brachiopod shells, consistent with previous observations of Cenozoic planktonic foraminifera, support the conclusion of little variation in Cenozoic seawater Li/Ca. Nonluminescent portions of Permian and Carboniferous brachiopods have Li/Ca ratios substantially lower (generally <10 µmol/mol) than modern, Cenozoic, or Devonian samples. Mass balance considerations, constrained by δ18O of brachiopods, suggest that low Li concentrations in Permo-Carboniferous seawater could be the result of a lower flux of dissolved Li from the continents and/or a higher flux of Li from seawater to clastic marine sediments. Nonluminescent Devonian brachiopods from a single hand specimen have Li/Ca ratios around 70% of the modern average. These Li/Ca ratios can be explained by either somewhat higher temperature with constant seawater Li/Ca, somewhat lower seawater Li/Ca at constant temperature, or a combination of slightly elevated temperature and slightly lower seawater Li/Ca