226 research outputs found
Exploring the role of regenerative and permaculture-informed Agriculture in promoting sustainable food systems: evidence from North America
No full textThis thesis explores approaches to make food systems more sustainable in North America and Newfoundland and Labrador (NL) using regenerative and permaculture methods, by addressing the growing challenges of soil degradation, climate variability, and dependence on imported food. It includes two main parts: a scoping review of 84 articles (from 1994 to 2024) on permaculture’s contribution to food security in North America and a qualitative study based on twenty semi-structured interviews with farmers, NGOs, and government officials in NL. The scoping review identifies six main themes: soil health and land management, water management, biodiversity, animal integration, energy and built systems, and community and economy, revealing widespread ecological and social benefits but persistent policy and market barriers. The qualitative study identifies how farmers in NL adopt regenerative practices like composting, livestock integration, cover cropping, and biochar application, but is constrained by the Crownland policy, environmental degradation, policy misalignment and limited institutional support. These studies show that practices focused on circular use and regeneration can improve ecological resilience, enable communities, and support local food systems. This connects ideas from the circular economy, agroecology, and political ecology. The thesis suggests practical ways to create policies that fit local needs and promote fairer, more sustainable food systems in NL and beyond
PBDE contamination in Newfoundland: exploring the interconnections between environmental pathways, sociobehavioral insights, and public health impacts
No full textPolybrominated diphenyl ethers (PBDEs) are widely used flame retardants that pose serious environmental and public health risks, especially for coastal communities dependent on marine resources. This thesis provides an integrated assessment of PBDE contamination in Newfoundland, examining emissions from a coastal legacy landfill in comparison to a modern landfill, and investigating the pathways into the marine ecosystem and the resulting impacts on human health. The study contributes to understanding PBDE contamination by offering a comprehensive assessment of environmental pathways, socio-behavioral factors, and public health impacts, with a particular focus on the influence of sociodemographic factors on seafood consumption patterns and risk perception. Geographic Information System (GIS) mapping characterized the spatial distribution of landfills and potential contaminant pathways, revealing potential routes for PBDEs to enter the marine environment. Elevated PBDE levels were identified in certain marine species, highlighting the ongoing presence of these chemicals. To assess bioaccumulation potential, trophic magnification models were utilized, indicating the potential for PBDEs to concentrate in higher levels of the food web. Community surveys revealed a disconnect between public awareness of pollutants and sustainable waste management practices, with sociodemographic factors, including age, education, and income level, significantly influencing both awareness and behavior. This study specifically examines the influence of these sociodemographic factors on seafood consumption patterns and risk perception. Furthermore, dietary exposure assessments, utilizing hazard quotients based on seafood consumption data, highlighted potential health risks for vulnerable populations, with estimated exposures exceeding established safety thresholds. This interdisciplinary approach not only addresses regional challenges but also offers a globally relevant framework for mitigating
persistent organic pollutants in similar settings. By bridging environmental monitoring, behavioral insights, and health risk assessments, the research provides actionable solutions for policymakers and public health practitioners worldwide. These findings underscore the need for integrated mitigation strategies in coastal regions to minimize PBDE contamination and protect public health. This research provides a transferable framework, advocating for sustainable landfill management practices, targeted community-level interventions to promote proper waste disposal and reduce reliance on contaminated seafood, and robust public health monitoring to assess and mitigate risks.Includes bibliographical references (pages 150-179
Reducing food waste through behavioral economics at the consumption level: evidence from a scoping review and an interventional study
No full textApproximately one-third of all food produced globally, around 1.3 billion tonnes, is wasted each
year. In high-income countries, much of this waste occurs at the consumption stage, in households,
restaurants, and institutional settings. In Canada, food waste accounts for over $60 billion annually.
This thesis investigates the potential of behavioural economics, specifically nudging, as a strategy
to reduce food waste through two integrated research components. The first is a four-week
intervention conducted in a restaurant in St. John's, NL. The intervention implemented three
nudging strategies to encourage customers to reduce waste. Food waste was measured daily
through leftover weight and takeout container usage. Results showed a reduction in plate waste
and an increase in the number of takeout boxes used. Findings demonstrated that low-cost and
non-intrusive nudges can positively influence consumer behavior in food service settings.
The second component is a scoping review that examines the global literature on behavioral
interventions to reduce food waste at the consumer level. The review identifies a range of
strategies, including portion design, incentives and social norm messaging, and summarizes their
effectiveness across different settings (e.g., households, restaurants, cafeterias). This research
provides practical implications for academic scientists, policymakers, food service providers, and
sustainability advocates
Multilevel Governance for Climate Change Adaptation in Food Supply Chains
No full textThe vulnerability of food supply chains to climate change is higher compared to other
industries due to its dependency on climatic conditions, temperature and water supply. As a
robust response to the vulnerability of food supply chains, it is essential to find ways of
linking the concepts of sustainable development, climate change adaptation and risk
governance into one paradigm. The risk governance of food supply chains is conducted by
and across both private and public spheres. Hence, in this chapter, we introduce a dual system
of governance to match the objectives of climate change adaptation, and discuss the
multiplicity and potential integration of both corporate-led private governance and public
governance based on the authority of governments and their institutions. The aim of this
chapter is to highlight climate change adaptation in relation to the practices of risk
governance of the food supply chains within a multilevel framework of private and public
policies. It explores the outlook of climate change adaptation in food supply chains, probing
the extent to which governance should be framed as an inter-governmental issue, a
national/local issue, an upstream supply chain issue or a downstream supply chain issue. The
study is carried out by delving into the international adaptation literature with focus on
different levels of framing the food supply chain and its adaptation to climate. We conclude
that it is important to marry the efficiency of food businesses with the attainment of wider
societal objectives such as sustainable development, climate change adaptation and food
security, in order to increase resilience of the overall food system.peerReviewe
Total pelvic exenteration in leiomyosarcoma - A case report
No full textLocally advanced high-grade leiomyosarcomas (LMS) with visceral involvement are difficult to manage. Here, we present a case of locally advanced high-grade sarcoma where total pelvic exenteration was undertaken to achieve complete cytoreduction. A 54-year-old lady with a prior history of hysterectomy and bilateral salpingoophorectomy done 8 years back for heavy menstrual bleeding presented to us with an abdomino-pelvic mass. Magnetic resonance imaging of the abdomen suggested large heterogeneous pelvic mass displacing urinary bladder anteriorly and abutting recto-sigmoid posteriorly with no luminal involvement. There was bilateral hydronephrosis. Computed tomography of the thorax revealed no evidence of metastatic disease. A review of previous biopsy and a repeat ultrasound-guided biopsy from the pelvic mass done at our institute suggested spindle-cell neoplasm. In view of pelvis confined disease in a young woman with well-preserved general condition, decision for surgical excision was taken. She underwent total pelvic exenteration with en bloc removal of mass, bladder, and involved portion of recto-sigmoid as the disease was infiltrating both the bladder and the recto-sigmoid. Her postoperative course was turbulent, but she recovered fully and was discharged 20 days after surgery. The operative specimen histopathology revealed high-grade LMS. She received four cycles of adjuvant chemotherapy and thereafter was kept on follow-up. Although she was clinically doing well, her general condition never improved beyond Eastern cooperative oncology Group 2. She also had persistent depressive symptoms. After 14 months of completion of treatment, she recurred with a huge abdominal disease. In view of her general condition and huge disease volume, decision was taken for supportive care only. LMS in advanced stages are difficult to manage. Even after aggressive management with radical exenterative surgery and chemotherapy, we could achieve only temporary control of locally advanced LMS
Novel Approaches for Offline Data-Driven Evolutionary Multiobjective Optimization
No full textMost multiobjective evolutionary algorithms (MOEAs) assume that analytical functions or simulation models are available while solving a multiobjective optimization problem (MOP). However, in some cases we must start with data and build approximation models known as surrogates that are later used to solve the MOP by an MOEA. These types of problems are called data-driven MOPs. This
thesis is devoted to solving so-called offline data-driven MOPs that are particularly challenging as no new data is available during the optimization process.
The author first presents approaches to utilize the uncertainty in the prediction of Kriging or Gaussian process (GP) surrogates as additional objectives. However, these approaches increase the complexity of the MOP being solved. Hence, the author proposes probabilistic selection approaches that can be embedded in a decomposition-based MOEA without further analytical derivations.
These approaches utilize Monte Carlo sampling and kernel density estimation to calculate the probability of selection criterion of the MOEA and later select individuals based on them. Next, the author proposes an interactive optimization framework that utilizes decision maker’s preferences for uncertainties in addition to preferences for objective values. The framework was further extended to use probabilistic selection approaches for a decomposition-based MOEA and a custom reference vector adaptation technique to consider uncertainty in the solutions during the adaptation process.
Building GPs with all the provided data becomes computationally expensive when the size of the data is large. Hence, the author finally proposes treed GP surrogates for multiobjective optimization (TGP-MO). They can be built with a relatively low computational cost and have a good accuracy exclusively in the regions around the optimal solutions. This thesis provides multiple novel approaches
and detailed experimental studies for solving offline data-driven MOPs with decision support that will enhance real-world problem-solving capabilities.
Keywords: metamodelling, surrogates, Pareto optimality, Kriging, Gaussian processes, evolutionary algorithm, decision making, uncertainty, interactive methods, preference informationunknown accessibilityei tietoa saavutettavuudest
Disinfection By-Products in Public Drinking Water Systems in Newfoundland and Labrador (Canada): A Population-Based Study for Assessment of the Environmental Health Risks
No full text
Odds ratio-based group sequential analysis for joint binomial and inverse binomial sampling
No full textABSTRACT: We consider two treatment comparison in a clinical trial setup where the responses from one treatment are a priori known for a fixed number of individuals and patients are allocated in a groupsequential way for the other treatment using inverse sampling. We consider the odds ratio as the measure of treatment difference at the end of each group, where for the calculation of odds ratios we consider the full data on one treatment, which are a priori known, and the available data on the other treatment up to that point of time. We have calculated the optimal number of index subjects for inverse sampling and examine the effects of different type I and type II error spending functions on group sequential testing in this context. The methodology is illustrated by using a real data set
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