cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
De-Noising via Wavelet Transforms Using Steerable Filters
Creators: name: Laine, Andrew F.
name: Chang, Chun-Ming
Publisher: name: Columbia University
Year: 1995
Subjects: Biomedical engineering

description: Feature extraction remains an important part of low-level vision. Traditional oriented filters have been effective tools to identify features, such as lines and edges. Steerable filters, which can be adjusted at arbitrary orientation, have made decisions of feature orientations more precise. Combined with a pyramid structure of a multiscale representation, these filters can provide a reliable and efficient tool for image analysis. This paper takes advantage of multiscale steerable filters in the context of de-noising. First a set of novel filters  are designed, that decompose the frequency plane into distinct directional bands. Next, we identify the dominant direction and strength at each point of an image from quadrature pairs of steerable filters. A nonlinear threshold function is then applied to the filtered coefficients to suppress noise. The denoised image is restored from coefficients modified at each level of transform space. We demonstrate the benefits of multiscale steerable filters for de-noising  and show that it can greatly reduce noise while preserving image features. Two examples are presented to verify the efficacy of the technique.
Mechanisms behind the neurotoxicity of 2C-I and 25I-NBOMe drugs
Creators: name: Gil-Martins, E.
name: Cagide, F.
name: Borer, A.
name: Barbosa, D. J.
name: Martins, D.
name: Fernandes, C.
name: Remião, F.
name: Borges, F.
name: Silva, R.
Publisher: name: Scientific Letters
Year: 2023

description: Background: New Psychoactive Substances (NPS) pose significant health and legal risks worldwide. At the end of 2021, the European Monitoring Centre for Drugs and Drug Addiction was monitoring 886 NPS, 106 of them phenethylamines [1]. Phenethylamine derivatives include 2,5-dimethoxyphenethylamine-based (2C) and N-benzylphenethylamine-based (NBOMe) drugs, widely known for their psychedelic effects. However, their toxicological profile remains poorly characterized [2,3]. Objective: To address this gap, 2C-I (2-(4-iodo-2,5-dimethoxyphenyl)ethanamine) and its corresponding NBOMe derivative (2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine) were synthesized and their neurotoxic profile evaluated, elucidating potential mechanistic pathways involved in drug-induced cytotoxicity. Methods: 2C-I and 25I-NBOMe were synthesized and structurally characterized by nuclear magnetic resonance and mass spectrometry techniques. Neuronal SH-SY5Y cells differentiated into a dopaminergic phenotype and primary rat cortical neurons, which were exposed to the drugs for 24 hours, were used for the in vitro experiments. Drugs’ neurotoxicity and the impact of MAO-mediated inhibition on drug-induced cytotoxicity were evaluated using the neutral red uptake assay. The capacity of the drugs to generate free radicals was estimated using the DCFH-DA probe and their impact on the intracellular GSH and ATP levels were assessed using the DTNB-reductase-recycling and the ATP bioluminescence assays, respectively. Changes in the mitochondrial membrane potential were investigated using the JC-1 probe. The chromatographic hydrophobicity index (CHI) of the drugs was also evaluated by Fast-Gradient RP-HPLC. Results: Both drugs exhibited a concentration-dependent neurotoxic effect, with 25I-NBOMe being more cytotoxic than its counterpart, which supports the drugs’ lipophilicity data. MAO inhibition had no significant impact on drug-induced cytotoxicity. No significant changes in ROS production were observed for both drugs, but a significant decrease in intracellular GSH and ATP levels, and significant mitochondrial membrane depolarization was detected. Conclusions: The introduction of a NBOMe substituent significantly increased all the evaluated neurotoxic effects, demonstrating the high potential of these drugs to induce severe adverse reactions.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Audio-walks: Moving digital learning off-screen and into balance
Creators: name: Poitras Pratt, Yvonne
Publisher: name: Office of Teaching & Learning
Year: 2022
Subjects: subject: Indigenous Education
subject: Indigeneity
subject: learning environment
subject: virtual learning
subject: wellbeing
subject: self-care
subject: audiowalk
subject: audiobooks
subject: wisdom
subject: Indigenous Ways of Knowing
subject: lifelong learning
subject: Werklund School of Education Online Pedagogy Series Vignettes

description: As an Indigenous scholar who teaches undergraduate and graduate-level Indigenous education courses, I often challenge myself to bring Indigenous pedagogy and practices, both theoretical and praxis-based, into my classes (see Louie et al., 2017; Poitras Pratt, 2020). In the context of what has been life-altering physical, emotional, and psychological challenges over the past several years, I have placed an increased focus on the collective wellbeing of students as a requisite priority. With public health restrictions as a factor in how and where we teach, educators and students alike have had to face not only hours of screentime but also any lingering anxieties they might have had in using digital technologies. In this vignette, I share my own attempt at bringing a greater sense of wellbeing and balance into my online teaching and learning spaces by introducing you to my emerging practice of audio-walks. My hope is that you will see how Indigenizing principles can support the use of digital technologies to achieve a more balanced learning environment.
Interactive wavelet processing and techniques applied to digital mammography
Creators: name: Koren, Iztok
name: Laine, Andrew F.
name: Taylor, Fred
name: Lewis, Michael
Publisher: name: Columbia University
Year: 1996
Subjects: Biomedical engineering

description: We present an interactive scheme for processing of digital mammograms relying upon a steerable dyadic wavelet transform. Coefficients of the translation and rotation-invariant transform are interactively processed before an inverse transform is applied. Analysis is carried out at dyadic scales and along arbitrary orientations. Local orientation is computed at each level of scale and spatial position and formulated into criteria for including or excluding specific orientations for contrast enhancement and  enhancing locally radiating structures. Transform coefficients that were selected for contrast enhancement are modified by a piecewise linear enhancement function. The presented scheme is flexible enough to enable efficient position, scale, and orientation based interactive processing and analysis.
Work Injuries and Mental Health Problems
Creators: name: Granger, Steven
Publisher: name: Haskayne School of Business
Year: 2022
Subjects: subject: Cognition
subject: Depression
subject: Life events
subject: Mental health
subject: Safety
subject: Work injuries
subject: Business Administration--Management
subject: Psychology--Industrial

description: Work injuries and mental health problems continue to inflict hardship on workers while imposing severe costs on organizations. Yet no comprehensive attempt to summarize the relationship between work injuries and mental health problems exists despite evidence of their association. Further, theoretical development of the relationship between work injuries and mental health problems has stalled in recent years. I address these issues by conducting three studies to explain the association between work injuries and mental health problems, conditions shaping and mechanisms underlying this association, and the expected trajectory of mental health problems prior to and following a work injury. Study 1 is the first comprehensive meta-analysis to look at the relationship between work injuries and mental health problems, ordering effects (i.e., work injuriesmental health problems, mental health problemswork injuries), and key conditions. Study 1 indicates the association between work injuries and mental health problems is small but robust, with larger effect sizes emerging when mental health problems are measured following a work injury as opposed to preceding a work injury. Study 2 examines cognitive mechanisms linking work injuries and mental health, as well as a key social condition distinguishing the work injury-mental health problems relationship using data from the Canadian Longitudinal Study of Aging (Raina et al., 2009). Study 2 results suggest maladaptive cognitions link prior work injury with later mental health problems, and memory-related issues link prior mental health problems with later work injury. Further, some evidence emerged for the role of social support mitigating the relationship between prior work injury and later mental health problems, but not vice versa. Finally, Study 3 examines the relationship between work injuries and mental health over time through an intensive longitudinal survey of young workers. Results from this study indicate that young workers tend to be resilient when confronting a work injury, with minor initial differences in mental health. Altogether, the results from these studies have important implications for occupational health and safety initiatives surrounding the prevention, recovery, and reporting of work injuries and mental health problems.
Toxicity of amphetamine-type drugs in rat cardiomyocyte cells involves oxidative stress and the formation of acidic vesicular organelles
Creators: name: Valente, M. J.
name: Araújo, A. M.
name: Carvalho, F.
name: Carvalho, M.
Publisher: name: Scientific Letters
Year: 2023

description: Background: Synthetic cathinones (SCs) are recreational psychoactive substances with pharmacological properties resembling those of classical amphetamines, such as 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) [1]. Although the use of SCs has been linked to adverse health outcomes, including myocardial infarction and sudden cardiac deaths [2], the underlying cardiotoxic mechanisms are still unknown. Objective: This study evaluates the potential in vitro cardiotoxicity mechanisms of two commonly abused SCs, 3,4-methylenedioxypyrovalerone (MDPV) and 3,4-methylenedioxymethcathinone (methylone), and compares them with those obtained for MDMA. Methods: The H9c2 cell line was exposed for 24 hours to a wide range of concentrations (0.01-15 mM for MDPV; 0.01-20 mM for MDMA and methylone). The cytotoxic response was measured through the MTT assay and the role of oxidative stress was evaluated through the production of reactive oxygen and nitrogen species (ROS/RNS). The formation of acidic vesicular organelles (AVOs) was also evaluated by fluorescence microscopy in cells exposed to EC30 or EC60 of each drug. Results: All compounds decreased cell viability in a concentration-dependent manner. MDPV and MDMA were the most toxic drugs (EC50 1.76, 1.86 mM, respectively), while methylone was the least cardiotoxic derivative (EC50 3.30 mM; p<0.0001 vs. EC50 MDMA; p<0.0001 vs. overall fit MDMA). MDMA triggered ROS/RNS production only at 0.8 mM (p<0.0001 vs. control) and MDPV only at 1.6 and 3 mM (p<0.01 vs. control). In contrast, methylone demonstrated a significant increase for all concentrations between 0.05 mM (p<0.0001 vs. control) and 12 mM (p<0.05 vs. control). All drugs prompted the formation of AVOs in a concentration-dependent manner. Conclusions: Our findings are the first to show that SCs cause in vitro cardiotoxicity, and that oxidative stress and autophagy may play a role in these events. Further research is needed to explore the underlying molecular mechanisms.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Vortices on Orbifolds
Creators: name: Kimura, Taro
name: Nitta, Muneto
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The Abelian and non-Abelian vortices on orbifolds are investigated based on the moduli matrix approach, which is a powerful method to deal with the BPS equation. The moduli space and the vortex collision are discussed through the moduli matrix as well as the regular space. It is also shown that a quiver structure is found in the Kahler quotient, and a half of ADHM is obtained for the vortex theory on the orbifolds as the case before orbifolding.
description: 25 pages, 4 figures; references added
Protocol for a scoping review of precision technologies for cattle monitoring
Creators: name: Besler, Brendon
name: Mojabi, Pedram
name: Murphy, James E
name: Wang, Zefang
name: Baker, Ryan
name: Pearson, Jennifer
name: Fear, Elise
Publisher: name: Libraries and Cultural Resources
Year: 2022
Subjects: Scoping review
Precision livestock farming
Veterinary medicine
Precision technology

description: Scoping Review Protocol
description: Livestock farming has increased in complexity considerably due to the increased demand for animal products combined with a decreasing number of farmers and ranchers. To meet this challenge, Precision Livestock Farming (PLF) aims to develop fully automated tools that continuously monitor animals, such as cattle. Ineffective cattle management can have significant animal welfare implications, as well as financial consequences for both farmers and the economy because of the size of this substantial industry globally. To our knowledge, no scoping review with explicit published search protocol has broadly examined PLF technologies for both beef and dairy cattle to identify gaps in current research.
Segmentation of Masses Using Continuous Scale Representations
Creators: name: Laine, Andrew F.
name: Huda, Walter
name: Harris, John
name: Chen, Dongwei
Publisher: name: Columbia University
Year: 1996
Subjects: Biomedical engineering

description: Many image processing and computer vision algorithms are surprisingly fragile when it comes to choosing various parameters and thresholds. There have been no good solutions to setting the proper value of the scale parameter in regularization networks. Local adaptation is needed in these networks to make them less brittle. Using an assumption of zero-mean, additive Gaussian noise, it can be shown that the scale parameter for edge detection problems should be proportional to the variance of any additive noise. However, these assumptions are too restrictive for most purposes, including digital mammography. More promising methods from Bayesian analysis are under investigation for setting the scale and other parameters by standard regularization-based methods. The Laplacian filter is a popular edge detector in image processing. However, knowledge of the feature size is necessary when choosing the proper scale for detection. It is common to make some assumptions about feature characteristics. For example, we can assume that microcalcifications in mammograms occur within finer scales of analysis since these features are characterized by small, high-contrast spots. Unfortunately, it is more difficult to make such general assumptions for masses in mammograms since they may assume distinct shapes and sizes, e.g., spiculated, round, or irregular. Thus, it is necessary to to identify an "optimal" scale for representation of masses. Once detected, their regions can be labeled to provide an area of local support for multiscale feature enhancement, including reinforcement of the "halo" effect, to assist in the visibility of masses. In this paper, we describe a method to segment a mass from its background using a continuous multiscale analysis. First, a suspicious region is identified, which may or may not contain a lesion. Next, the region is used as a matched filter to select a wavelet basis. A soft threshold is then applied. If the selected region contains a feature, the mammographic feature is segmented from its background for further processing.
Evaluation of the systemic oxidative stress status upon in vivo exposure to tramadol and tapentadol
Creators: name: Cardoso, C.
name: Dinis-Oliveira, R. J.
name: Leal, S.
name: Barbosa, J.
name: Faria, J.
Publisher: name: Scientific Letters
Year: 2023

description: Background: Tramadol and tapentadol are synthetic centrally acting analgesic opioids, used in the treatment of moderate to severe pain [1]. Despite their optimized therapeutic and safety profiles, these compounds are associated with adverse effects, namely CNS and respiratory depression, abuse and dependence [2, 3]. Oxidative stress is one of the main toxicity mechanisms triggered by opioids [1, 4, 5]. Objective: The aim of this study was to evaluate putative systemic oxidative stress changes induced by a therapeutic dose of tramadol and tapentadol. Methods: Three groups of Wistar rats (9 animals each) were administered intraperitoneally with 50 mg/kg tramadol/tapentadol during 8 alternate days, while the control group was treated with saline solution [1]. Serum total antioxidant capacity and ROS/RNS levels were determined through spectrophotometry, whilst serum cysteine and homocysteine levels were quantified through ELISA, with commercial kits, according to the manufacturers’ instructions. Statistical data analysis was performed through an Analysis of Variance (ANOVA), followed by Dunnett’s multiple comparison’s test. Results: An increase in ROS/RNS levels was observed in tramadol (*p<0.05) and tapentadol (***p<0.001) groups. However, regarding the antioxidant concentration, no significant differences were found. A statistically significant decrease in the concentration of cysteine was observed in the tramadol-administered group (*p<0.05). Furthermore, a statistically significant increase in the concentration of homocysteine was evident in the tapentadol-administered group (*p<0.05). Conclusions: The increase in ROS/RNS levels demonstrates that tramadol and tapentadol cause oxidative stress, with no changes in the total antioxidant capacity. However, as cysteine may have an antioxidant effect, the decrease in its serum levels may indicate that tramadol affects the levels of adjuvant antioxidants [6]. Since high levels of homocysteine causes oxidative stress, the increase in its serum concentration indicates that tapentadol induces oxidative stress [7]. In conclusion, tramadol and tapentadol must have a controlled prescription given their potential oxidative toxicity.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Peasants, Movements, and Survival of Democracy in Haiti and Nicaragua
Creators: name: Vernet, Ricardo
Publisher: name: Arts
Year: 2022
Subjects: subject: Democracy
subject: Peasant
subject: Movements
subject: Authoritarianism
subject: Party
subject: Political Science
subject: FOS: Political science

description: The standard class perspectives of democratization claim a strong bourgeoisie and organized working class are more likely to foster democracies than the large peasantry. This dissertation tests this assertion in Haiti and Nicaragua, two large agricultural societies which experienced transitions to democracy in the early 1990s. In Haiti, the peasant-backed movement acceded to power after overthrowing the Duvalier regime, but the movement was overthrown in a bloody coup orchestrated by the bourgeois opposition with the help of the army. Nicaragua experienced a similar crisis roughly around the same period when a popular revolutionary movement finally dislodged the Somoza regime from power. But unlike Haiti, movement actors seized power immediately after the fall of the dictatorship and made gradual concessions to the bourgeois opposition. In February 1990, the movement was defeated after ten years of in power by a coalition of parties. When does peasant-backed movements succeed in building democracies? This dissertation investigates the factors that explain the divergence in the trajectory of the transition in Haiti and Nicaragua. The dissertation shows that transitions in the context of large agricultural societies tended to be complicated by the size of the movement. Large peasant backed movements were naturally predisposed to seek majority rule because such move was consistent with their strategic interests. Large peasant-backed movements were naturally predisposed to seek majority rule because this was consistent with their strategic interests. The dissertation argues that two conditions acted as a kind of antidote against this, the institutionalization of the movement prior the transition and the context of the international environment. Where these conditions were met, sectoral elites tended to make democratic political rather than relying on mass power to impose their will on the opposition. Thus, democracy is not destined to fail where large peasant-backed movements accede to power.
An Interpretive Description of New Graduate Nurses’ Transition into Professional Practice
Creators: name: McDonald, Stephanie Ann
Publisher: name: Nursing
Year: 2022
Subjects: subject: new nurse(s)
subject: nurse graduate
subject: newly qualified nurse
subject: newly graduated nurse
subject: socialization
subject: transition
subject: Nursing
subject: FOS: Health sciences

description: Background. Newly graduated nurses (NGNs) have one of the highest turnover rates within the nursing profession, leaving their first job or the profession altogether within the first 12 months of professional practice. Not only is this costly to the healthcare system, but high turnover causes significant instability within the workforce, which affects the safety and quality of patient care. Also, NGNs are an essential human resource for addressing the nursing shortage. Understanding why high turnover is occurring among NGNs, is vital for the future stability of the nursing profession. Aim. The aim of this research was to explore the experiences of bachelor prepared nurses during the first year of nursing employment. A gap in the literature was identified, as recent studies have focused on socialization tactics based on NGN research from the earlier 2000s. As healthcare is constantly changing, it is important to understand what NGNs are experiencing at the current time. Thus, the findings from this study can inform clinical practice, leading to improved transition and socialization of NGN into professional practice. Method. An interpretive description research design was utilised to understand the phenomenon. Ten NGN study participants, who graduated within the last 18 months, were interviewed. Data was analyzed using thematic analysis and an interpretative description was developed and used to inform clinical practice. Findings. NGN transition remains a highly complex and nuanced process. Three broad categories emerged: NGN disposition, collegial supports, and work environment. The findings offer a contemporary and expanded understanding of NGNs’ transition experiences.
Does paraquat exposure affect peroxisomal enzyme activities in trout?
Creators: name: Resende, A. D.
name: Lobo-Da-Cunha, A.
name: Rocha, E.
Publisher: name: Scientific Letters
Year: 2023

description: inducing the intracellular formation of reactive oxygen species with consequent cellular damage [1,2]. Paraquat is a potent herbicide that can be highly toxic for fish, causing morphological and biochemical alterations in several organs [3,4]. Objective: Since activity of peroxisomal enzymes is implicated in the reactive oxygen species and xenobiotic metabolisms [5], a subacute exposure of brown trout (Salmo trutta f. fario) to a waterborne relevant environmental concentration of paraquat was performed to verify if some peroxisomal enzymes, particularly from the liver and kidney, would be significantly altered. Methods: Immature (1-year-old) brown trouts were exposed to 0.3 mg/L of paraquat for 7 and 15 days; concentration was renewed every 2-3 days. Ten fish were collected on day 0 of the experience as control. At the end of the exposure period, ten animals from each group, paraquat and control, were collected. The catalase, d-amino acid oxidase, and urate oxidase enzyme activities were measured spectrophotometrically in liver and renal homogenates. Statistical analysis recurred to one-way ANOVA. Results: The liver's enzyme activities did not differ significantly between the control and paraquat groups after 7 and 15 days of exposure. In the kidney, urate oxidase was not detectable, and no statistical differences were found between the control and paraquat groups. During the experiment, however, both control and exposed groups showed increased catalase activity while decreasing d-amino acid oxidase activity. Conclusions: At the tested concentration, paraquat did not affect the studied peroxisomal enzymes in the liver and kidney. Notably, there were changes over time, warning that captivity or experimental stress influenced the enzyme activities. This aspect deserves further study. Moreover, research with other concentrations and targets should be done to refine the assessment of paraquat’s toxicological potential for peroxisomes.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Knights of the Post: Professional Perjurers in Early Modern England, circa 1550–1700
Creators: name: Storkova, Hana
Publisher: name: Arts
Year: 2022
Subjects: subject: early modern
subject: knights of the post
subject: perjurers
subject: professional perjurers
subject: Elizabethan
subject: Stuart
subject: legal system
subject: England
subject: History
subject: History--European
subject: Law
subject: FOS: Law

description: Historians have long been aware that several aspects of the early modern English legal system were prone to manipulation and misuse, though some of these remain unstudied or barely acknowledged. One such topic is the interference of the knights of the post, about whom historians know very little except that they were professional perjurers in early modern England. This thesis uses late sixteenth and seventeenth century sources to reconstruct who the knights of the post were, what courts they operated in, what perjuries they provided, and how individuals in early modern England attempted to deter them, ultimately seeking to determine how much of an impact these professional perjurers had on the legal system. These “knights” were ascertained to be well-trained professional criminals, primarily active in the common law courts but also in the criminal justice system, who continued to subvert justice despite numerous attempts to stop them. Given their widespread influence, historians need to take into account the knights of the post and their actions when studying the early modern English legal system.
Visualization of mammograms via fusion of enhanced features
Creators: name: Koren, Iztok
name: Laine, Andrew F.
name: Smith, Suzanne
name: Nickoloff, Edward Lee
name: Taylor, Fred
Publisher: name: Columbia University
Year: 1999
Subjects: Biomedical engineering
Breast--Radiography
Contrast-enhanced magnetic resonance imaging

description: Image enhancement in mammography is typically concerned with either general visibility of all features or conspicuity of a specific sign of malignancy. We describe a synthesis of the two approaches through fusion of locally enhanced microcalcifications, circumscribed masses, and stellate lesions. Both local processing and image fusion are performed within a single wavelet transform framework which contributes to the computational efficiency of the method. The algorithm not only allows for efficient combination of specific features of importance, but also provides a flexible framework for incorporation of distinct enhancement methods and their independent optimization.
Clinical and toxicological effects of GLP-1 agonists
Creators: name: Teixeira, M. J.
name: Dias Da Silva, D.
Publisher: name: Scientific Letters
Year: 2023

description: Background: Glucagon-like peptide-1 receptor (GLP-1) agonists have been investigated and applied for the treatment of type 2 diabetes mellitus (T2DM) and obesity due to their ability to increase glucose-dependent insulin secretion. However, due to their recent therapeutic use, less is known in what concerns the long-term toxicological effects of these medicines. Objective: Herein, we compiled the available information on the clinical and toxicological effects of GLP-1 agonists. Methods: A literature search was carried out in PubMed (U.S. National Library of Medicine) to find relevant articles dealing with the clinical and toxicology effects of GLP-1 agonists, without a limiting period and placing a special focus on clinical studies. Results: All GLP-1 agonists increase hyperglycaemia-induced insulin secretion, suppressing glucagon secretion in hyperglycaemia or euglycaemia, slowing down gastric empty, preventing large post-meal glycaemic increments, and reducing caloric intake and body weight [1]. In addition, GLP-1 agonists are claimed to have pleiotropic effects on the cardiovascular system, which might be of particular relevance for patients with T2DM and/or obese, as these individuals are at increased cardiovascular disease risk and display poorer recover from cardiovascular deleterious events, compared to controls [2]. GLP-1 agonists seem to have side effects on pancreas and thyroid, but current evidence does not show a cause-effect association between these drugs and the development of pancreatitis, pancreatic cancer, or thyroid cancer. The use of these drugs, mainly exenatide, has been associated with acute kidney injury, as well as local reactions in injection site [3]. Conclusions: GLP-1 agonists are a newly and widely recommended class of glucose-lowering agents with the ability to lower plasma glucose comparable to insulin regimens, but with a lower risk of hypoglycaemia and the added benefit of weight loss. More clinical trials and pharmacovigilance information are however needed to clarify the cardiovascular and overall safety profile of GLP-1 agonists.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Immigration, Integration, and Intersectoral Partnership: A Critical Examination of Introductory Winter Sport Programmes for Newcomers to Canada
Creators: name: Barrick, Simon John
Publisher: name: Kinesiology
Year: 2022
Subjects: subject: immigration
subject: integration
subject: winter sport
subject: Canada
subject: Canadian identity
subject: qualitative research
subject: inclusion
subject: multiculturalism
subject: race and ethnicity
subject: Education--Social Sciences
subject: Recreation
subject: Sociology
subject: FOS: Sociology

description: Sport participation is popularly constructed as a key aspect of integration for newcomers into their new countries of residence. These claims, however, are critiqued by sport and migration researchers. While newcomer sport participation is receiving increasing scholarly interest, lived experiences of newcomers in introductory winter sport programmes and the (in)efficacy of such programmes remains underexplored. Winter sports hold a central place within Canadian culture and identity, making the intersection between winter sport, immigration, integration, and Canadian identity a timely topic of investigation. I approached this research from a relativist ontological as well as interpretivist and social constructionist epistemological perspectives. The overarching purpose was to explore the realities of designing and implementing introductory winter sport programmes as well as the lived experiences of newcomer participants. First, six Canadian Intro to Sport programmes involving newcomers were examined using an interpretivist, qualitative research design. Results from this study were incorporated into designing the WinSport Newcomers Programme (WNP), an intersectoral community partnership comprising sport administrators, settlement service practitioners from three separate organizations, and me. I adopted a qualitative case study research design to explore the lived experiences of WNP participants and their parents as well as the (in)efficacy of the WNP as an intersectoral community partnership. Results illuminated the value of winter sport participation for newcomers to Canada as well as various challenges facing the sustainability of newcomer winter sport participation. The WNP represents a maturing intersectoral community partnership that has excelled at introducing newcomers to Canadian winter sports. Yet, various weaknesses (e.g., collaborators negotiating job-related time pressures) are obstructing the collaboration’s effectiveness. Together, the results critique and identify shortcomings in newcomer introductory winter sport programmes, while also offering important insights into how newcomer introductory winter sport programmes may be designed to foster positive outcomes.
Border identification of echocardiograms via multiscale edge detection and shape modeling
Creators: name: Laine, Andrew F.
name: Zong, Xuli
Publisher: name: Columbia University
Year: 1996
Subjects: Biomedical engineering

description: An algorithm for endocardial and epicardial border identification of the left ventricle in 2-D short-axis echocardiographic images is presented. Our approach relies on shape modeling of endocardial and epicardial boundaries and prominent border information extracted from image sequences. The algorithm consists of four steps; wavelet-based edge detection, border segment extraction, border reconstruction, and boundary smoothing. Wavelet maximum representation of edges, dynamic shape modeling and matched filtering techniques are utilized to determine the center point of the left ventricle, and carry out feature extraction of border segments to better approximate endocardial and epicardial boundaries. The algorithm can reliably estimate the center point of the left ventricle, and also determine both endocardial and epicardial boundaries. Myocardial boundary identification is autonomous requiring no human input for initial estimation of boundary locations. Sample experimental results are shown for endocardial and epicardial border identification in 2-D short-axis echocardiograms.
Isolation, characterization and assessment of the photoprotective effect of two fungal melanins
Creators: name: Olaizola, Carolina
Publisher: name: University of British Columbia
Year: 2012

description: Melanins are a diverse group of pigmented biopolymers present in living organisms at all phylogenetic levels. Properties such as light scattering and absorption through a wide range of wavelengths, and scavenging of free radicals are common to all melanins, and render them as molecules having the capacity to protect against UV damage. Fungal melanins are more chemically diverse than animal melanin, and have radioprotective properties. In this research, I isolated melanins from the basidiomycete Agaricus bisporus and the ascomycete Grosmannia clavigera, and assessed their photoprotective effect in human skin cells. Both fungal melanins differed in physicochemical characteristics and functional groups evidenced by infrared spectral analyses. Differences in the evaluated bioactivity were also observed. Agaricus bisporus melanin behaved similar to synthetic DOPA melanin, significantly enhancing cell viability measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in human dermal fibroblasts irradiated with a high dose of ultraviolet B (UVB). Agaricus bisporus melanin also effectively reduced the amount of reactive oxygen species (ROS) induced by UVB in these cells. Measurements of light transmission at 315 nm of melanin solutions suggest that the observed photoprotective effect was likely to be due to a UV filter effect. No photoprotection was observed in cells exposed to UVB in the presence of Grosmannia clavigera melanin. Unlike synthetic DOPA melanin, both fungal melanins were potentially cytotoxic for human dermal fibroblasts. My results suggest that differences observed in the fungal melanin bioactivity are possibly linked to differences in their chemistry and optical properties.
From mixed valence to the Kondo lattice regime
Creators: name: Kumar, Pramod
name: Vidhyadhiraja, N. S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Many heavy fermion materials are known to crossover from the Kondo lattice regime to the mixed-valent regime or vice-versa as a function of pressure or doping. We study this crossover theoretically by employing the periodic Anderson model within the framework of the dynamical mean field theory. Changes occurring in the dynamics and transport across this crossover are highlighted. As the valence is decreased (increased) relative to the Kondo lattice regime, the Kondo resonance broadens significantly, while the lower (upper) Hubbard band moves closer to the Fermi level. The resistivity develops a two peak structure in the mixed valent regime: a low temperature coherence peak and a high temperature 'Hubbard band' peak. These two peaks merge yielding a broad shallow maximum upon decreasing the valence further. The optical conductivity, likewise exhibits an unusual absorption feature (shoulder) in the deep mid-infrared region, which grows in intensity with decreasing valence. The involvement of the Hubbard bands in dc transport, and of the effective f-level in the optical conductivity are shown to be responsible for the anomalous transport properties. A two-band hybridization-gap model, which neglects incoherent effects due to many-body scattering, commonly employed to understand the optical response in these materials is shown to be inadequate, especially in the mixed-valent regime. Comparison of theory with experiment carried out for (a) dc resistivities of CeRhIn5, Ce2Ni3Si5, CeFeGe3 and YbIr2Si2; (b) pressure dependent resistivity of YbInAu2 and CeCu6; and (c) optical conductivity measurements in YbIr2Si2 yields excellent agreement.
description: 24 pages,12 figures,accepted in J.Phys.: Condens. Matter
Optimality and Sustainability of Delayed Impulsive Harvesting
Creators: name: Lawson, Jennifer Lynn
Publisher: name: Science
Year: 2022
Subjects: subject: Delays
subject: Impulsive Harvesting
subject: Optimal Harvesting
subject: Logistic Equation
subject: Impulsive Delayed Harvesting
subject: Population Dynamics
subject: Education--Mathematics

description: Optimal and sustainable management of natural resources requires knowledge about the behaviour of mathematical models of harvesting under many different types of conditions. In this thesis, the effects of delays on the optimality and sustainability of harvesting models are studied, with a particular focus on delayed impulsive harvesting models. We begin by considering delays within a continuous harvesting model and derive sufficient conditions for stability of harvesting models with general growth and harvesting rate. We also derive maximum sustainable yields for models with both logistic and Gompertz growth, and show that they are delay dependent. Then we consider the main object of the thesis, a logistic differential equation subject to impulsive delayed harvesting, where the deduction information is a function of the population size at the time of one of the previous impulses. A close connection to the dynamics of high-order difference equations is used to conclude that while the inclusion of a delay in the impulsive condition does not impact the optimality of the yield, sustainability may be highly affected and is once again delay-dependent. Maximum and other types of yields are explored, and sharp stability tests are obtained for the model, as well as explicit sufficient conditions. It is also shown that persistence of the solution is not guaranteed for all positive initial conditions, and extinction in finite time is possible, as is illustrated in the simulations. The results of this thesis imply that delays within harvesting should be kept short to maintain the sustainability of resources.
Quantification of right and left ventricular function with real-time three-dimensional ultrasound
Creators: name: Angelini, Elsa D.
name: Laine, Andrew F.
name: Donis, Joshua
name: Gersony, Deborah
name: Homma, Shunichi
Publisher: name: Columbia University
Year: 2001
Subjects: Biomedical engineering
Echocardiography

description: Presents a study for validation of real-time three-dimensional ultrasound as a diagnostic tool in patients with primary pulmonary hypertension. Dynamic analysis of the heart is performed via quantification of right and left ventricle volumes. Segmentation of ventricular cavities is performed via a deformable-model for a set of  denoised frames spread over an entire cardiac cycle. Spatio-temporal denoising is carried out by brushlet analysis that has been optimized by incorporating space and time coherence. in. texture characterization. Quantitative measures for right and left ventricular ejection fraction are compared to clinical MRI of the same patients.
In silico study of (thio)xanthones-mediated P-glycoprotein activation
Creators: name: Veiga-Matos, J.
name: Dos Santos, D. J. V. A.
name: Sousa, E.
name: Prieto Vicente, M.
name: Remião, F.
name: Silva, R.
Publisher: name: Scientific Letters
Year: 2023

description: Background: P-glycoprotein (P-gp) is an efflux transporter located at the apical membrane of important barrier tissues, playing a crucial role in the detoxification of endobiotics and xenobiotics [1]. (Thio)xanthonic derivatives have been shown to be able of activating P-gp without increasing its expression, promoting an immediate increase in the amount of transported substrates. Thus, P-gp activation limits the intracellular accumulation of harmful P-gp substrates and, consequently, reduces their toxicity [2,3]. Objective: The aim of this study was to elucidate, in silico, by molecular docking analysis, the P-gp binding sites of different (thio)xanthonic derivatives previously reported as P-gp activators, and to correlate the in silico predictions with in vitro data reported in the literature. Methods: Molecular Operating Environment (MOE) software was used to build all the 3D-structures (with minimized energy) and Autodock Vina was used to perform the molecular docking analysis, to obtain the affinity energy between the human P-gp model [at the drug-binding pocket (DBP) and nucleotide binding domains (NBDs) 1 and 2] and P-gp activators. The best pose was visualized and the number and type of interactions of the evaluated compounds with specific P-gp residues was verified by using the BINANA software. Results: The molecular docking analysis revealed that most of P-gp activators preferentially bind to DBP or NBD1. Relatively to DBP, almost all P-gp activators bind to residues located in the modulators (M)-site. Furthermore, the evaluation of interactions between P-gp activators and P-gp residues indicated a pattern, since several P-gp activators shared the same hydrophobic contacts and other interactions (hydrogen-bonds and pi-pi, t-stacking and cation-pi interactions) with specific P-gp residues. Conclusions: The present study confirmed that (thio)xanthonic derivatives are capable of binding to P-gp, specifically at the M-site of the DBP and at the NBD1 and, therefore, these binding interactions may potentially be involved in (thio)xanthonic derivatives-mediated P-gp activation.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Multiscale Denoising and Enhancement of 3D Rotational X-ray Imaging for Percutaneous Vertebroplasty
Creators: name: Jin, Yinpeng
name: Angelini, Elsa D.
name: Mangla, Sundeep
name: Choi, In Sup
name: Kemkers, Richard
name: Timmer, Jan
name: Laine, Andrew F.
Publisher: name: Columbia University
Year: 2003
Subjects: Biomedical engineering

description: 3D rotational X-ray (3DRX) imaging has been suggested as an alternative to CT scans for evaluating percutaneous vertebroplasty procedures. We present in this study preliminary work on denoising and enhancement of 3DRX data sets with dyadic wavelet thresholding. Thresholding operators were tuned to accommodate for spatial variability of the anatomical features and the noise energy at each level of decomposition. Results are presented for three clinical data sets with quantitative measurements of contrast to noise ratio (CNR) and qualitative evaluation with three- dimensional rendering of vertebral bodies having cement fillings. Wavelet denoising demonstrated the efficient on enhancement of subtle vertebral edges and clearer delineation of the cement filling contours which improves the accuracy in clinical practice and helps to make 3DRX more competitive when compared to CT.
title: Entwicklung und Implementierung einer Windows-Applikation zur Erkennung von Werbeblöcken
Creators: name: Zink, Fabian
Publisher: name: FH Münster
Year: 2002
Subjects: subject: 004 Datenverarbeitung; Informatik

description: Die gesamte Diplomarbeit ist ein Demonstrationsmodell. Es gelang Algorithmen zu finden, mit denen man auf optischem Wege Unterschiede zwischen einer Werbesendung und dem normalen Fernsehprogramm erkennen konnte.
title: Framework for the development of resilience
title: Ways to develop resilience
titleType: AlternativeTitle
Creators: name: Bello, Jhonattan
Publisher: name: Office of Research
Year: 2022
Subjects: Resilience
Framework for the development of resilience
Framework
Development
Mental health

description: The strategies found in the study "Promoting resilience in post-secondary students: A case study" by Jhonattan Bello, were presented in a logical procedure to be implemented in the classroom. This framework represents the approach of instructors when they facilitated the promotion of resilience. The framework for the development of resilience starts with the creation of a safe environment with trusting relationships. Then spend some time finding the purpose or meaningful goal that will allow students and instructors to think about the path to follow and set some realistic expectations about the process to get there. Once students have focused on a meaningful goal and started the journey, many adversities will become more evident. Sharing stories and creating a plan that integrates the resources and experiences found in those stories will also become a crucial tool for the process of resilience. Instructors will support students all the time by modelling flexible thinking and showing ways to navigate the resources needed to succeed. This figure is a resulting piece from the "Emergent themes for the development of resilience" figure created by Jhonattan Bello
MRI Scan Time Reduction through K-Space Data Sharing in Combo Acquisitions with a Spin Echo Sequence
Creators: name: Mekle, Ralf
name: Wu, Ed X.
name: Laine, Andrew F.
Publisher: name: Columbia University
Year: 2001
Subjects: Biomedical engineering
Magnetic resonance imaging

description: We propose a technique to reduce scan time for magnetic resonance imaging (MRI) through sharing of k-space data between images. As a proof of concept, we ran simulations of MRI experiments based on Bloch equations using a spin echo sequence. We generated images of a realistic brain phantom containing the tissues: white matter, gray matter, and cerebrospinal fluid. A set of k-space data was acquired while varying two acquisition parameters: repetition time (TR) and echo time (TE). This data set was then used to reconstruct multiple images of different contrast. Customized variation of TR and TE allowed us to obtain different contrast weightings of signal values. We present results for 2-contrast and 3-contrast "combo" acquisitions and compare them with images from acquisitions with fixed TR and TE. Scan time reductions of 30%-52% were achieved. Artifacts stemming from non-uniform and tissue-dependent data weighting in the Fourier domain were minimized through systematic optimization of the order of phase encoding and of variation schemes for TR and TE. No obvious degradation of image quality and resolution was observed. In addition, we quantitatively analyzed preservation of contrast, image profiles of sharp tissue boundaries, and signal-to-noise-ratio.