Extraction and Quantification of Atrazine

Undergraduate Basi

Shaping our literate lives: Examining the role of literacy experiences in shaping positive literacy identities of doctoral students

The purpose of this study was to examine the ways in which literacy histories and present literacy experiences of doctoral students shaped their literacy identities. Data were collected through surveys, interviews, and visual identity representations. This paper focuses on the literacy stories of two doctoral students with positive literacy identities. Findings suggest that participants valued literacy as a social learning experience from an early age through higher education. These social experiences with reading and writing can take many forms and can be embraced in various home and school contexts. Additionally, these findings highlight the need for schools to create and nurture such experiences across all grade levels, through multiple forums, which may lead to positive literacy identities

Comparison of boreal ecosystem model sensitivity to variability in climate and forest site parameters

Ecosystem models are useful tools for evaluating environmental controls on carbon and water cycles under past or future conditions. In this paper we compare annual carbon and water fluxes from nine boreal spruce forest ecosystem models in a series of sensitivity simulations. For each comparison, a single climate driver or forest site parameter was altered in a separate sensitivity run. Driver and parameter changes were prescribed principally to be large enough to identify and isolate any major differences in model responses, while also remaining within the range of variability that the boreal forest biome may be exposed to over a time period of several decades. The models simulated plant production, autotrophic and heterotrophic respiration, and evapotranspiration (ET) for a black spruce site in the boreal forest of central Canada (56°N). Results revealed that there were common model responses in gross primary production, plant respiration, and ET fluxes to prescribed changes in air temperature or surface irradiance and to decreased precipitation amounts. The models were also similar in their responses to variations in canopy leaf area, leaf nitrogen content, and surface organic layer thickness. The models had different sensitivities to certain parameters, namely the net primary production response to increased CO2 levels, and the response of soil microbial respiration to precipitation inputs and soil wetness. These differences can be explained by the type (or absence) of photosynthesis-CO2 response curves in the models and by response algorithms of litter and humus decomposition to drying effects in organic soils of the boreal spruce ecosystem. Differences in the couplings of photosynthesis and soil respiration to nitrogen availability may also explain divergent model responses. Sensitivity comparisons imply that past conditions of the ecosystem represented in the models\u27 initial standing wood and soil carbon pools, including historical climate patterns and the time since the last major disturbance, can be as important as potential climatic changes to prediction of the annual ecosystem carbon balance in this boreal spruce forest

Role of Farmer Knowledge in Agroecosystem Science: Rice Farming and Amphibians in the Philippines

Rice (Oryza sativa) agriculture provides food and economic security for nearly half of the world’s population. Rice agriculture is intensive in both land and agrochemical use. However, rice fields also provide aquatic resources for wildlife, including amphibians. In turn, some species may provide ecosystem services back to the farmers working in the rice agroecosystem. The foundation for understanding the complexity of agroecosystem–human relationships requires garnering information regarding human perceptions and knowledge of the role of biodiversity in these rice agroecosystems. Understanding farmer knowledge and perceptions of the ecosystem services provided by wildlife in their fields, along with their understanding of the risks to wildlife associated with agrochemical exposure, can inform biodiversity preservation efforts. In June and July 2014, we used focus groups and structured and semi-structured interviews that engaged 22 individuals involved in rice agriculture operations in Laguna, Philippines, a village close to the International Rice Research Institute in Los Baños, Philippines, to learn more about farmer perceptions and knowledge of amphibians in their rice fields. We found that many, though not all farm workers (managers, tenants, and laborers) noted declines in amphibian populations over time, expressed how they incorporated frogs and toads (Anura) into their daily lives, and recognized the value of amphibians as ecosystem service providers. Specifically, farmers noted that amphibians provide pest-management through consumption of rice pests, act as biomonitors for pesticide-related health outcomes, and provide a local food and economic resource. Some farmers and farm workers noted the general cultural value of listening to the “frogs sing when it rains.” Overall, our findings demonstrate that farmers have an understanding of the value of amphibians in their fields. Future efforts can support how engagement with farmers and farm workers to evaluate the value of wildlife in their fields can lead to directed education efforts to support biodiversity conservation in agroecosystems

Boreal forest CO2 exchange and evapotranspiration predicted by nine ecosystem process models: Intermodel comparisons and relationships to field measurements

Nine ecosystem process models were used to predict CO2 and water vapor exchanges by a 150-year-old black spruce forest in central Canada during 1994–1996 to evaluate and improve the models. Three models had hourly time steps, five had daily time steps, and one had monthly time steps. Model input included site ecosystem characteristics and meteorology. Model predictions were compared to eddy covariance (EC) measurements of whole-ecosystem CO2exchange and evapotranspiration, to chamber measurements of nighttime moss-surface CO2release, and to ground-based estimates of annual gross primary production, net primary production, net ecosystem production (NEP), plant respiration, and decomposition. Model-model differences were apparent for all variables. Model-measurement agreement was good in some cases but poor in others. Modeled annual NEP ranged from −11 g C m−2 (weak CO2source) to 85 g C m−2 (moderate CO2 sink). The models generally predicted greater annual CO2sink activity than measured by EC, a discrepancy consistent with the fact that model parameterizations represented the more productive fraction of the EC tower “footprint.” At hourly to monthly timescales, predictions bracketed EC measurements so median predictions were similar to measurements, but there were quantitatively important model-measurement discrepancies found for all models at subannual timescales. For these models and input data, hourly time steps (and greater complexity) compared to daily time steps tended to improve model-measurement agreement for daily scale CO2 exchange and evapotranspiration (as judged by root-mean-squared error). Model time step and complexity played only small roles in monthly to annual predictions

Surgery Poster - 2019

Surgery Poster - 2019https://scholarlycommons.libraryinfo.bhs.org/research_education/1016/thumbnail.jp

Effects of Cowichan Lake water management on Vancouver Lamprey in British Columbia and identification of possible enhancement opportunities

Vancouver Lamprey (also known as Cowichan Lake Lamprey; Entosphenus macrostomus) is listed as a threatened species under the Species at Risk Act (SARA). This species is endemic to three interconnected lakes on Vancouver Island, British Columbia. Cowichan Lake, one of the lakes in which this species resides, is a water reservoir managed to meet the downstream conservation and anthropogenic needs of the watershed. Currently Cowichan Lake water levels and outflows to the Cowichan River are controlled in part by the water control weir at the outlet of Cowichan Lake. Recent droughts in the Cowichan River watershed have resulted in lower than normal summer water levels in the lake which has resulted in reduced outflows to the river as well as dewatering of alluvial fans and lake margins. These dewatered areas include Vancouver Lamprey critical habitat, which is protected under SARA. Protection of Vancouver Lamprey’s critical habitat from destruction was accomplished in February 2020 through a SARA critical habitat order made under subsections 58(4) and (5), which invoked the prohibition in subsection 58(1) against the destruction of the identified critical habitat. It is worth noting that protections under SARA apply to all aquatic species listed as extirpated, endangered or threatened regardless of whether the species is on federal or provincial lands. Decreased lake water levels potentially destroy critical habitat and negatively impact spawning and rearing for this species. Fisheries and Oceans Canada’s (DFO) Fish and Fish Habitat Protection Program (FFHPP) has requested that Science Branch provide science advice on the effect water management has on Vancouver Lamprey spawning and rearing habitat, as well as identification of other conservation issues and enhancement opportunities for critical habitat. The assessment and advice arising from this Canadian Science Advisory Secretariat (CSAS) Science Response (SR) process will be used to inform resource managers on the water management of Cowichan Lake and support the development of current and new water use policy. It may also inform future water management decisions related to the design/operation of the new weir. The specific objectives of this review are to: 1. Evaluate what range of water levels are required to provide maximum protection to Vancouver Lamprey and its critical habitat by life stage for adults (spawning), eggs (incubation), and ammocoetes (feeding and rearing), and when these water levels are required by the species for these life stages (i.e. biologically significant periods). 2. Evaluate how much critical habitat (in square meters or hectares) is being affected by lake draw downs, and at what lake elevations critical habitat starts being affected within the normal range of current water management (full supply level and zero storage with minimum release of 7.08 m3/s into the Cowichan River). 3. Identify conservation issues for Vancouver Lamprey and the types of potential enhancement or rehabilitation opportunities that may exist for this species in the Cowichan Lake watershed. 4. Examine and identify uncertainties in the data and methods. This Science Response results from the regional peer review of January 18, 2023 on the effects of Cowichan Lake water management on Vancouver Lamprey in British Columbia and identification of possible enhancement opportunities