Fixed Point Methods in Convex Minimization for Large Data

So-called first order methods are widely used in machine learning methods involving big data because of their conceptual and algorithmic simplicity. The central problem in this paper is the optimization problem x0 ∈ arg min_{x∈C} f (x) on a suitable convex and closed domain C ⊆ R^n stemming from a machine learning problem based on training data X := {d^(i), y^(i)}^{N}_{i=1} whereby the objective function is a regularized mean square error. Here, the objective function belongs to the important class of convex functions of the form, f (x) = (1/2) x^T Q x + q^T x + c, where q ∈ R^n and Q is a positive semi-definite (n×n)-matrix. The minimization problem above is seen as an equivalent system of nonlinear equations. Indeed, the problem min_{x∈C} f (x), is equivalent to a fixed-point problem T (x) = x for a projection operator T : C → C, T (x) := P_C (I − α∇f )(x), a contraction operator for which the Banach Contraction Principle applies (P_C :R^n → C being the orthogonal projection operator). In the concrete, it appears that x = T (x) if and only if ∇f (x) = 0. The fixed point iteration scheme in the Banach Contraction Principle amounts, due to the form of the contraction T , to the widely used gradient descent algorithm for the minimization problem

Hunger, academic performance, and the moderating role of social support in Canadian youth

1.7 million young Canadians experience hunger on a regular basis. Youth who experience hunger are more likely to underperform in school which in turn can lead to negative outcomes and trajectories that impact their long-term health, wellbeing, and ability to succeed in adult life. Public health interventions require an evidence base to address this phenomenon. This thesis will therefore provide observational epidemiological data to describe whether social supports, as a potential point of intervention, act as modifiers of relationships between hunger and the relative ability of adolescents to perform well in school. This study consists of two components: firstly, a contemporary descriptive analysis of the distribution of hunger within Canadian youth, and second, an evaluation of the relationship between hunger and academic performance among Canadian youth, and the potential moderating role of social support along this pathway. All analyses were conducted using the 2018 cycle of the Canadian Health Behaviour in School-aged Children (HBSC) study. Results from this study will be important theoretically and also provide foundational evidence in support of integrated efforts to support youth in academic and community settings

Spotting Potential Threats: A Tool to Inform the Proactive Management of Invasive Insects on a Regional Scale

Invasive insects present a complex modern global crisis with the potential to have dire consequences. Proactive management is considered the most effective management approach, but conservation managers often face many barriers to engagement. This study introduces a tool for managers to identify invasive insects that hold the potential to expand their range northwards on a regional scale. The tool utilizes community science, horizon scanning, and a mixture of peer-reviewed and grey literature. It is applied using a case study on the potential for Lycorma delicatula, the spotted lanternfly (SLF), to spread to the Niagara Region of Ontario, Canada. The findings affirm that the SLF demonstrates an ability to spread to the Niagara Region due to the proximity of recently established populations, the warming effects of climate change, and viable invasion pathways. The tool demonstrates the potential to be used by managers to identify other range-expanding insects and inform proactive management

Beatty Mill account book

William Beatty, a native of County Tyrone, Ireland, settled in the Thorold area in 1835. He may have first operated a grist mill in Port Robinson. His next venture was a tannery in Thorold. With his two sons, William Jr. and James Hughes Beatty they began the Beatty sawmill operations around 1850 in nearby Grantham Township. The two operations were in close proximity to one another. The saw mill was located in Grantham Township near Lock 21 of the second Welland Canal. In 1863 the Beatty’s acquired the timber rights on a parcel of land measuring 234 square miles near Parry Sound. William Jr. managed the lumber business of the new Parry Sound Mills and James supervised the transportation operations. Shipbuilder Melancthon Simpson built several ships for the Beatty family business. They include the steamers Waubuno (1865), Cumberland (1871) and Manitoba (1871) and the propeller Asia (1873). The ships were built at Simpson’s yards in St. Catharines, Port Robinson and Thorold. In 1875, the mill was sold to Gillespie & McLean, and afterwards to McCleary & McLean. The Beatty family went on to concentrate their business in the shipping / transportation industry as well as the creation and expansion of the town of Parry Sound.The Beatty Mill account book (1869-1875) includes the names of many local businesses, including: Lybster Cotton Mill, James Norris, Wesleyan Methodist Church John Abbey, George N. Oile [Oille], William Parnall, Thorold Post, Parry Sound Mills, and Lewis Shickluna

Factors Driving Consumers' Continuous Usage of Online Grocery Shopping Platforms in the Post-Pandemic Era

The purpose of our research is to explore several factors that influence consumers' intention to continue using online grocery services or platforms after the Covid-19 pandemic. We conducted a field survey of 314 Canadian consumers who use online grocery services. Our study draws from the Theory of Planned Behavior and the Expectation-Confirmation Theory, and we incorporated the constructs of Perceived Risk and Trust into the proposed theoretical framework to deepen understanding in the area. Based on these frameworks, we formulated fifteen hypotheses. This study investigates factors that influence consumers' continued use of online grocery services. The study highlights the significant influence of perceived usefulness, trust, attitude, and perceived risk in the model. The results also show that perceived risk plays a crucial role in participants' decisions to continue to use online grocery services. We explored the effects of demographic variables such as age (Generation), gender, employment, and income level on the relationship between intention and continued intention. Additionally, the results show that consumers' intention to use online grocery services differ before Covid-19, during, and after the pandemic. Finally, our findings can help retailers tailor their marketing strategies to enhance online grocery service adoption

Letters by Thomas Elwyn to his brother William, 1805, 1812

Thomas Langdon Elwyn (c. 1776-1816) was born in Canterbury, England. He graduated from Oxford University in 1794 and emigrated to the United States the following year. Elwyn married Elizabeth Langdon, who was the daughter of John Langdon, a New Hampshire statesman.Three letters written by Thomas Elwyn in Portsmouth, New Hampshire to his brother William in England, 1805-1812. Two of the letters were written in 1812 and mention the War of 1812 between Britain and the United States. The first letter is dated at Portsmouth [New Hampshire], March 14, 1805, and is addressed to George’s Coffee House, Temple Bar, London. The letter is four pages. Elwyn writes about his work publishing an anonymous pamphlet titled “Letter to a Federalist” defending Thomas Jefferson and his Administration against Federalist critics. Although he did not put his name to it “the feds discovered the author and everything was sought for to abuse me personally”. He writes about the praise and criticism he received since its publication but is very pleased with his work, noting that “the facility with which I write is amazing to myself…my elegance of language, admirable choice of words, and great power of commanding the attention may enrich me very greatly”. Elwyn had sent a copy of this publication to President Jefferson and later received a letter from the President thanking him for his support. The second letter is dated at Portsmouth, January 25, 1812, and is addressed to W.B. Elwyn, Barrister at Law, Bristol, England. The letter is four pages. Elwyn writes about a possible reunion with his brother in England but notes that “I will never…take my family from this place whilst Mr. Langdon [his father-in-law] lives. They shall at least stay to assuage the pains and enliven the last dull scenes of his life”. He goes on to tell his brother not to emigrate, despite the disappointment that this will cause Elwyn and his family. This is because of the political state of the country. There is “no talk but of war within the walls of Congress. An act already passed for raising 25,000 additional regulars. Another nearly so far embodying 50,000 volunteers. 1,900,000 appropriated for the purchases of munitions of war. The President speaking of nothing but resistance to the hostility of Britain. Yet no one alarmed—not a thought of war in the minds of anyone but Congress”. Elwyn also writes that although he is still a Federalist, he has decided to abandon American public life. The third letter is dated at Portsmouth, December 10, 1812 and is addressed to W.B. Elwyn, Barrister at Law, Bristol, England. The letter is four pages and mostly discusses the war. He writes that “There are so many difficulties in the way of writing in the present unhappy relations of our two countries, that I shall beg you to do towards me as I shall towards you—write whenever you have an opportunity, always think of me with affection and confidence in my regard and let us flatter ourselves that we all continue in good health and shall one day be recompensed for the painful alienation we suffer”. Elwyn writes that he lives as quietly as possible and his property has not been severely injured by the war. He adds that “England has behaved admirably in most respects since the war began. Prejudice and passion subside every day. As manly a war as you will on the drumbeaters in Canada—no sniveling, pitiful submission, no contempt, but for heaven’s sake, no burnings, no wanton destruction and cruelty. This would unite all parties against you…Recollect we are a free country and the reluctance of a great potion of our people to engage at all in the war. This will account for the ridiculous management of our Canada expeditions.

The current state is a crime: Decolonizing experiential education on the Brock University campus

Indigenous ways of knowing and being have always been experiential. With this, our Canadian post-secondary institutions that have been working to grow experiential education and experiential learning opportunities have an obligation to acknowledge these Indigenous roots in order to avoid further appropriation. With two thirds of the Truth and Reconciliation Commission (TRC) of Canada’s 94 calls to action focused on education, including post-secondary, the Ontario Government has also recommended that post-secondary institutions in the province provide students with a minimum of two experiential learning opportunities within their academic courses by the time they graduate. This Participatory Action Research (PAR) project at Brock University was designed and executed in full collaboration with Indigenous peoples and looks at a campus with a focus on decolonization as well as experiential learning through an Appreciative Inquiry framework to best determine how experiential education can be decolonized. Using semi-structured interviews, focus groups, and institutional documents that speak to the current state of experiential learning as well as institutional strategic goals, ten themes were developed. These highlight settler tendencies, the current state of experiential education, recommendations for decolonization and an ideal future state, important approaches to consider when decolonizing as an individual and as a campus, cautions to heed, as well as values and emotions to consider. In order to decolonize experiential learning and the campus authentically, Indigenous voices must be and have been amplified in this process

It’s Time to Recognize Wikipedia as a Health Information Resource

Editorial: Patient Education ColumnWith more than 300 language editions, Wikipedia offers accessible health information written in plain language to a wide audience. Having survived more than twenty years, it is broadly considered the “grown-up” of the internet due to its sheer longevity and maturity. Along with evidence that Wikipedia is more reliable than widely believed, it has emerged as the most frequently accessed web site for health information despite a lingering stigma. Grounded in real-life examples of health events, the author reinforces Wikipedia as a tool for public health education. With wider acceptance of Wikipedia as a health information resource, existing opportunities for education, investment, and improvement of the world’s largest encyclopedia can be cultivated

Insufficient sleep, impaired sleep, and injury in Canadian adolescents: a cross-sectional analysis of the 2017/18 Health Behaviour in School-aged Children study

Background. Insufficient and impaired sleep are common in adolescents, and can impact their health and safety. One negative consequence of poor sleep is risks for unintentional injuries, yet evidence addressing this relationship among Canadian adolescents is limited in scope. In this study, we documented contemporary sleeping behaviours of Canadian adolescents and examined their relationship with risks for injuries. Methods. A cross-sectional study was employed, using records from the 2017/18 Canadian Health Behaviour in School-aged Children study (n=21,745). Participants’ usual sleep patterns, including insufficient sleep (on school and non-school days), impaired sleep, and daytime sleepiness, and annual reports of any and serious medically treated injury were obtained. Descriptive and hierarchical multivariable Poisson regression analyses were performed, with adjustment for potential confounders, and tests of interaction by age and gender. Results. Insufficient sleep, impaired sleep, and daytime sleepiness affected 11.3% to 35.3% of adolescents; these estimates varied by age and gender. Sleep indicators displayed modest, but consistent associations with risks for “any injury”, whereas sleep impairment and daytime sleepiness were the only meaningful and statistically significant risk factors for “serious injuries”, after adjustment for potential confounders. The analysis of interactions showed that boys with insufficient sleep on non-school days and impaired sleep had significantly higher injury risks compared to girls without poor sleep in these domains. Conclusion. Indicators of poor sleep affected up to one-third of Canadian adolescents, and were associated with risks for various types of injury. Sleep hygiene may act as a plausible focus for public health and prevention initiatives to mitigate injury risks

Analyzing Twitter Sentiment and Hype on Real Estate Market: A Topic Modeling Approach

This study examines the relation between sentiment and hype (intensity of coverage) on Twitter and the local housing market prices across 10 U.S. cities of the S&P/Shiller-Case Composite Home Price index from 2010 to 2021. Using Latent Dirichlet Allocation (LDA) topic modeling algorithm, we identify seven unique topics related to the housing market based on people's tweets: Households, Economic policy, Commercial real estate, Price and rate, Residential housing, Investing, and Future trends. We gather and analyze data on house price indexes, fundamental economic factors, and sentiment and hype scores for the discovered topics. The study finds that the sentiment of Price and rate, Residential housing, and Future trends are significantly and positively related to future house price changes. In contrast, the lags of sentiment of Commercial real estate and Investing have a negative relation with house price. Moreover, we document that hype scores not only have a positive relation with house price changes for all topics but also outperform sentiment scores for forecasting housing market prices. Overall, the study highlights the potential benefits of integrating social media data into existing economic models to gain a more comprehensive understanding of the factors driving fluctuations in the housing market