cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Novel insights into healthy humans’ faecal carriage of enterococci: Enterococcus lactis is as a dominant highly bacteriocinogenic species
Creators: name: Almeida-Santos, A. C.
name: Duarte, B.
name: Teixeira, M. J.
name: Tedim, A. P.
name: Novais, C.
name: Peixe, L.
name: Freitas, A. R.
Publisher: name: Scientific Letters
Year: 2023

description: Background: Enterococcus lactis (Elts) [former Enterococcus faecium (Efm) clade-B] has been greatly associated with human colonization, but its epidemiology is unknown since this reclassification [1]. We aimed to assess the contemporary faecal carriage of enterococci species among healthy-humans (HH) in Portugal and get novel insights about Efm/Elts differences. Methods: Fifty-one faecal samples (29-women/22-men;18-85/~45-years) from HH in Northern Portugal (February-July 2022) were processed by enrichment/selection steps with/without ampicillin, vancomycin or linezolid. Efm, Elts and other species were identified by PCR [2, 3] and antibiotic-susceptibility by disk-diffusion/broth-microdilution (EUCAST/CLSI). Representatives/sample (n=40) were characterized by Whole-Genome-Sequencing/CGE-tools, including a homemade bacteriocins(bac) database. Qualitative bacteriocin production/sensitivity was performed in sequenced Efm/Elts and selected clinical VREfm (vancomycin-resistant-Efm) and Elts (all-against-all) using the soft-agar-overlay technique. Results: All samples carried Enterococcus (n=337), with most containing Elts-73% (p<0.05) and/or E.faecalis (Efs)-61% and variable occurrence for Efm-45%, E.hirae-16%, and/or other species (<2%). Samples (24% multidrug-resistant) included isolates resistant to erythromycin [73%;erm(B)/msr(C)], tetracycline [63%;tet(M)/tet(L)], high-level-streptomycin (22%;ant(6)-Ia/str), chloramphenicol (12%;cat/fexA/fexB/optrA/poxtA), quinupristin-dalfopristin (12%), high-level-gentamycin [4%;aac(6’)-Ie-aph(2’’)-Ia] and linezolid (4%-optrA/poxtA;MIC50/MIC90 4-mg/L). Acquired linezolid-resistance genes were detected in two samples: optrA (one E. thailandicus; MIC=8-mg/L) and optrA+poxtA (ST128-Efm; MIC=8-16-mg/L). Typical bacteriocins and plasmids from clinical Efm/Efs were scarce. Elts (2-5 bac; 100%-bac-genes+) and Efm (0-9; 71%-bac+) shared bacteriocins (e.g.,entP/entQ) contrasting with others exclusive of Efs (0-2;22%-bac+). No isolate could inhibit all or be inhibited by all, but the ones with more bacteriocins were less inhibited. Most Efm/Elts showed no activity against each other but ~30%/each inhibited most strains tested, including VREfm. Conclusions: Elts is one predominant enterococci gut species that would be misidentified as Efm without an accurate Efm/Elts distinction. Elts co-exist with Efm in the intestine, but specific Efm/Elts inhibiting most strains tested may contribute to microbiota restoration after antibiotic treatments. Linezolid-resistance genes finding is worrisome, suggesting an environmental/food-chain role in this acquisition since they were not described in enterococci from Portuguese hospitals before.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Population Psychiatric Medication Prescription Rates Following a Terrorist Attack
Creators: name: DiMaggio, Charles J.
name: Galea, Sandro
name: Madrid, Paula
Publisher: name: Columbia University
Year: 2007
Subjects: Public health

description: Introduction: While several population-based studies have documented behavioral health disturbances following terrorist attacks, a number of mental health service utilization analyses published thus far have presented conflicting conclusions. Problem:  Our purpose was to determine if mental health service utilization increased following a terrorist attack by assessing changes in psychoactive drug prescription rates. Methods: We measured the rate of selective serotonin reuptake inhibitor (SSRI) prescriptions among New York State Medicaid enrollees before and after the terrorist attacks of September 11, 2001, and assessed the association between geographic proximity to the events and changes in the rate of SSRI prescriptions around September 11, 2001 Results:  From September to December 2001, among individuals residing within 3 miles of the WTC site, there was an 18.2% increase in the SSRI prescription rate compared to the previous 8 month period (p=0.0011).  While there was a 9.3% increase for non-New York City residents, this change was not statistically significant (p=0.74). Conclusions:  We conclude that there was a quantifiable increase in the dispensing of psychoactive drugs following the terrorist attacks of September 11, 2001 and that this effect varied  in response to geographic proximity to the events. These findings build on the growing body of knowledge on the pervasive effects of disasters and terrorist events for population health and demonstrate the need to include mental and behavioral health as key components of surge capacity and public health response to mass traumas.
Traveltime tomography for land seismic data
Creators: name: Law, Bernard Ki-Yun
Publisher: name: Science
Year: 2022
Subjects: subject: Seismic Processing
subject: Velocity estimation
subject: Tomographic Algorithms
subject: Education--Mathematics
subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Computer Science

description: Full wave form inversion (FWI) uses the full recorded wavefield to determine the physical properties of the subsurface. Due to the lack of wide aperture and low-frequency data, a reliable low-frequency starting velocity model is often required. A velocity model derived from pre-stack depth migration (PSDM) is typically used as the starting model for FWI. Iterative PSDM is an expensive process, and it also requires a velocity macro model. Traveltime tomography methods are efficient algorithms to construct a smooth velocity model using refraction and reflection traveltimes. However, with limitations caused by acquisition constraints, data quality and assumptions used in traveltime tomography methods, the velocity model determined by these methods can be sub-optimal and results in degradation in the depth image. In this thesis, I address several strategies to improve tomography and to incorporate error measurements from refraction and reflection waveforms into the tomographic inversion kernels. My goal is to help to alleviate the inherent limitations in traveltime tomography methods.
Vaccination Navigation, Access, and Hesitancy Among Refugees in Calgary, AB: A Scoping Review Protocol
Creators: name: Aghajafari, Fariba
name: Ness, Alyssa
name: McClurg, Caitlin
name: Wall, Laurent
name: Pooladi-Darvish, Arshya
Publisher: name: Community Health Sciences
Year: 2022
Subjects: Refugee
COVID-19
vaccine hesitancy
vaccine access

description: Funded by the Foundation for Advancing Family Medicine-Co-RIG II Grant
description: Background: The COVID-19 vaccines provide between 80—95% protection against the disease and to reach herd immunity, between 70-83% of the population needs to be vaccinated. Access, as well as hesitancy, to vaccine can affect reaching this target. Refugees and new immigrants are at higher risk of being infected with COVID-191,3, and they may have inequitable access to vaccine. To overcome the inequity to access vaccine and addressing hesitancy in refugees and new immigrants, various outreach programs have been implemented globally 2,3,4,5,6. Objectives: The aim of this scoping review is to explore the model of delivery of Covid-19 vaccination and other common infectious disease vaccinations in newcomers and refugee populations. Method: Articles will be included if they were published in the year 2000 or later, focused on vaccine or immunization delivery, programs, initiatives, or policies among refugees, immigrants, migrants, asylum seekers or newcomers; or addressed vaccine hesitancy; and occurred during epidemic or endemic times. Study designs included in this scoping review will be randomized controlled trials or observational studies. MEDLINE, Ovid Healthstar, OVID Embase, OVID Medline, Web of Science, Scopus, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Science Direct, Academic Search Complete, Google Scholar, Social Work Abstracts, and JSTOR databases were searched using controlled vocabulary terms and keywords for the following concepts: Covid-19 and major immunizations generally administered on a schedule, vaccines OR immunizations, refugees, asylum seekers, newcomers and immigrants. Grey literature was searched using Google’s site search feature for relevant news articles or social media, as well as non-government organization (NGO) and intergovernmental organization (IGO) websites for information specific to those organizations. Articles from academic databases will be exported to COVIDENCE followed by two rounds of screening, including the initial title/abstract review, followed by full text screening. Conflicts will be resolved by the Primary Investigator. Grey Literature will be collected in an excel spreadsheet and included to inform the background and discussion.
Order alpha_s^2 magnetic penguin correction for B decay to light mesons
Creators: name: Kim, C. S.
name: Yoon, Yeo Woong
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We compute the order alpha_s^2 correction to the matrix element of magnetic penguin operator for B meson decaying to light mesons within the QCD factorization framework. We explicitly show that the soft and collinear divergences are canceled out, so that the validity of QCD factorization is confirmed. We present the result of the calculation in complete analytic forms. The result is also applied to B -> K pi decays, and we find that the order alpha_s^2 correction of magnetic penguin operator can considerably reduce the coefficient of penguin amplitude a^c_{4,I}. The reduction is stronger for the imaginary part.
description: 19 pages, 5 figures, appendix added, typos fixed, published version
Evaluating Yoga Therapy for Irritable Bowel Syndrome
Creators: name: D'Silva, Adrijana
Publisher: name: Cumming School of Medicine
Year: 2022
Subjects: subject: Irritable bowel syndrome
subject: Yoga
subject: Meditation
subject: Telehealth
subject: Virtual healthcare
subject: Gastroenterologist
subject: Health Sciences
subject: Public Health

description: Background: Irritable bowel syndrome (IBS) is a chronic disease of the brain-gut axis. Mind-body therapies such as yoga target the central nervous system, autonomic nervous system, immune and endocrine systems involved in the brain-gut axis to improve IBS symptoms and other patient outcomes such as mental health and quality of life. Virtually delivered yoga programming has not been tested nor have the experiences of participants in these programs been explored. Further, we are unaware of the beliefs and attitudes of IBS patients and gastroenterologists towards yoga. Objectives: This thesis had four objectives and they were to: 1) identify patients’ attitudes, subjective norms, perceived behavioural control for yoga, and underlying beliefs and intentions to practice yoga; 2) identify gastroenterologists’ attitudes, perceived supports, barriers and facilitators and intention to recommend a yoga program as part of routine medical care for patients with IBS; 3) explore the feasibility and efficacy of an eight-week virtual yoga program on IBS symptom severity and other patient-reported outcomes compared to an advice-only control group; and 4) explore and describe participants’ experiences in a virtual yoga program, and its impact. Methods: Using mixed-methods, cross-sectional surveys were used to answer aims 1 and 2. A randomized clinical trial answered objective 3 and semi-structured interviews answered objective 4. Results: Patients (N=109) reported controllability, self-efficacy, and affective attitude predicted their intention to practice yoga. Gastroenterologists (N=79) reported they were ten times more likely to recommend yoga if they agreed yoga improves IBS symptoms, however, most were not recommending yoga due to lack of confidence and scientific evidence. The randomized controlled trial (N=79) found virtually delivered yoga was safe, feasible, and efficacious in improving IBS symptoms, quality of life, stress, and fatigue. The interviews revealed the participants had overwhelmingly positive experiences in the program. Conclusions: Virtually delivered yoga programming is acceptable, safe, feasible, and efficacious in the treatment of IBS. Future research is needed to explore how virtually delivered yoga may be positioned as a therapy in the management of IBS.
IS THE ACCELERATED EXPANSION OF THE UNIVERSE RESPONSIBLE FOR THE EMERGENCE OF THE FINE-STRUCTURE CONSTANT (1/137)?
Creators: name: RECCHIA, ARCANGELO
Publisher: name: Zenodo
Year: 2024
Subjects: subject: Particle physics
subject: Physical cosmology
subject: Astrophysics
subject: Theoretical physics
subject: Atomic physics
subject: Quantum physics
subject: planck constant
subject: observable universe
subject: fine structure constant

description: In this contribution, it is shown how the fine-structure constant emerges when two systems interact, one of which, light, perceives the universe as static due to not experiencing the passage of time, while the other, matter, experiences accelerated expansion. In this way, the fine-structure constant can be related to the rate of expansion of the universe; alpha can be expressed through the ratio to the fourth power of the theoretical radius R(uT)=13,6 Gly of the universe to the measured radius R(uI) = 46,5 Gly. 

                                                                       alpha = (13,6 Gly/46,5 Gly)^4 = 1/137                                                      (1.21)

From the equation (1.21), it is clear that, since the rate of expansion of the universe has not remained constant over time, the value of the fine-structure constant must also have changed (unless there is over time a proportional variation of the speed of light c), as have other physical constants and quantities. This implies that physical laws have not remained unchanged throughout the history of the universe. Regarding the spatial variation of alpha, the issue is more complex and falls outside the scope of this work.
Harmonic Analysis on Quantum Complex Hyperbolic Spaces
Creators: name: Bershtein, Olga
name: Kolisnyk, Yevgen
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Algebra (math.QA)
subject: Functional Analysis (math.FA)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 17B37, 20G42, 81R50, 33D45, 42C10

description: In this paper we obtain some results of harmonic analysis on quantum complex hyperbolic spaces. We introduce a quantum analog for the Laplace-Beltrami operator and its radial part. The latter appear to be second order $q$-difference operator, whose eigenfunctions are related to the Al-Salam-Chihara polynomials. We prove a Plancherel type theorem for it.
Local Thermometry of Neutral Modes on the Quantum Hall Edge
Creators: name: Venkatachalam, Vivek
name: Hart, Sean
name: Pfeiffer, Loren
name: West, Ken
name: Yacoby, Amir
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A system of electrons in two dimensions and strong magnetic fields can be tuned to create a gapped 2D system with one dimensional channels along the edge. Interactions among these edge modes can lead to independent transport of charge and heat, even in opposite directions. Measuring the chirality and transport properties of these charge and heat modes can reveal otherwise hidden structure in the edge. Here, we heat the outer edge of such a quantum Hall system using a quantum point contact. By placing quantum dots upstream and downstream along the edge of the heater, we can measure both the chemical potential and temperature of that edge to study charge and heat transport, respectively. We find that charge is transported exclusively downstream, but heat can be transported upstream when the edge has additional structure related to fractional quantum Hall physics.
description: 24 pages, 18 figures
Insights into the phylogeny, resistome, virulome and host adaptation from Gardnerella genome analysis
Creators: name: Teixeira, P.
name: Sousa, M.
name: Grosso, F.
name: Ribeiro, T.
name: Peixe, L.
Publisher: name: Scientific Letters
Year: 2023

description: Background: Gardnerella spp. is often seen as evidence of vaginal pathologies, although members of this genus can also be found in the urinary and vaginal microbiota of asymptomatic women [1,2], making its role in the urogenital tract unclear. Objective: To assess phylogenomic and functional analysis of Gardnerella genus. Resistance (ARGs) and virulence genes (Vg) was also explored to unveil their role in health and urogenital disease development. Methods:Twenty-nine Gardnerella isolates from urine (U, n=22) and vaginal swabs (VSn=7) of women [24 asymptomatic, 5 with overactive bladder (OAB)] were identified by cpn60 and WGS (NovaSeq 6000; Illumina). Together with118 genomes from public databases (from U (n=35), VS (n=82) blood (n=1), and unknown samples (n=2)), we used TYGS platform and fastANI for species identification. Phylogenomic and pangenome analyses were performed using anvi’o v7.1 and Roary. Vg were annotated with COG and KEGG databases, and ARGs with AMRFinder Plus. Vg presence/absence outoputs were analyzed with R. Results: 4 species and 10 genomic species were identified, 41% of the collection being comprised by G. vaginalis. ANI and dDDH values are insufficient for distinguishing Gardnerella species. Pangenome was composed by4537 gene clusters and the core genome of by 514. Differences in carbohydrates and amino acid metabolism and absence of correlation of functions with human body sites or disease were observed. The virulome and Gardnerellaspecies/genomospecies exhibit are intertwined. ARG to aminoglycosides (aph(3')-Ia), macrolides (mefA, msrD, ermX), tetracyclines (tetM, tetL), lincosamide and streptogramins (lsaC) were detected in several isolates. Open pangenomes were observed in G. vaginalis, G. leopoldii, G. swidsinskii and GG3. Conclusions: Gardnerella comprises 4 species and 10 genomic species. Core genome analysis, ANI and dDDH are recommended for appropriate species assignment. Gardnerella species/genomospecies are associated with a particular set of VFs and metabolic functions. ARGs with clinical relevance were also observed in different Gardnerella species.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Application of low-cost waste material from the petroleum industry in wastewater treatment and polymer composites
Creators: name: Eshraghian, Afrooz
Publisher: name: Schulich School of Engineering
Year: 2022
Subjects: subject: Asphaltene
subject: Clay
subject: Polymer composite
subject: Wastewater
subject: Dielectric
subject: Methyl orange
subject: Rheology
subject: Dispersion
subject: Carbon nanotube
subject: Engineering--Chemical
subject: Engineering--Environmental
subject: Materials Science
subject: Psychology--Experimental

description: In this thesis, diverse applications of solid petroleum waste, including asphaltene and clay, are discussed. As part of this thesis, it is hypothesized that asphaltene and clay interact with polymers and pollutants in wastewater. By interacting with pollutants, they can adsorb pollutants, and by interacting with polymers, they can disperse in polymers, and thus can be used as adsorbents for wastewater treatment and as fillers in polymer composites. To use asphaltene for adsorbing pollutants from wastewater, it is hypothesized that asphaltene functionalization will change the surface properties of asphaltene, leading to enhanced adsorption. Acid-treated asphaltene is used as an adsorbent for the removal of methyl orange from wastewater. Modified asphaltene has a large surface area and oxygen and nitrogen functionalities, leading to 96% removal of MO from 20 mg/L MO solution. Moreover, the Freundlich isotherm model, pseudo-second-order, and intraparticle diffusion models describe the adsorption process very well. In addition, the asphaltene can be easily regenerated using ethanol, and the removal percent is still 64% after five cycles.The second part investigates the compatibility of different asphaltenes, with different polymers including polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), and polycarbonate (PC). By careful choice of the polarity of asphaltene-polymer pairs, mixing technique, and melt viscosity of the polymer, the dispersion of asphaltenes and final properties of composite materials can be tuned. For example, at 2.5 wt.% of asphaltene, more polar asphaltene showed 26% and 177% larger asphaltene agglomerates in PP and PS, respectively, than the less polar asphaltene. In the third part of this thesis, clay functionalization is hypothesized to improve clay-polymer interactions. Thus, the effect of nanoclay, representative of clay waste from petroleum industry, on dielectric properties in the X-band (8.2-12.4 GHz) of synthesized nitrogen-doped carbon nanotube (N-CNT)/nanoclay/ polyvinylidene fluoride (PVDF) nanocomposites is investigated. The incorporation of nanoclay improves the dielectric properties, i.e., the dissipation factor of N-CNT/PVDF nanocomposites. For instance, incorporation of 0.5 wt% nanoclay into N-CNT/PVDF nanocomposite at 1.0 wt% N-CNT loading results in 61% and 57% reduction in the dissipation factor and agglomeration area ratio, indicating improved N-CNT dispersion in PVDF.
Dietary replacement of fishmeal with polychaete meal (Alitta virens) impacts European seabass acute stress response
Creators: name: Costa, R. S.
name: Monteiro, M.
name: Thoresen, L.
name: Kousoulaki, K.
name: Valente, L. M. P.
Publisher: name: Scientific Letters
Year: 2023

description: Background: Reducing the incorporation of fisheries-derived ingredients in aquafeeds is a major trend to support aquaculture’s sustainable growth. Due to its high protein content and biochemical composition, polychaete meal (PM) is emerging as a viable alternative to fishmeal and potential functional ingredient [1]. Objective: This study aimed to evaluate the physiological response of Dicentrarchus labrax (European seabass) to acute stress, after feeding with diets containingincreasing levels of PM (Alitta virens). Methods: A fishmeal-based diet (FM, control) and three diets containing PM at 2.5% (PM2.5), 5% (PM5), and 10% (PM10), to replace 10-40% of fishmeal, were fed to seabass juveniles for 93 days. Upon trial conclusion, fish underwent a stress challenge: 1-minute air exposure followed by 5-minute overcrowding. After 1 hour of recovery, plasma and liver samples were collected. Plasma metabolite levels, immune parameters and liver oxidative status of stressed fish were compared to those of non-stressed fish (n = 18). Results: Stress induced a significant increase in all biomarkers analyzed, regardless of the dietary treatment. Plasma glucose levels were significantly higher in fish fed PM10 compared to fish fed FM, independently of stress. Accordingly, cortisol levels were not affected by diet. Although basal plasma lactate levels were unaffected by diet, levels after stress were significantly higher in fish fed PM2.5 compared to fish fed FM. PM also impacted liver redox status. In relation to the control, basal GST activity was significantly higher in fish fed PM diets, as was glutathione content in fish fed PM2.5 and PM5. Nonetheless, differences among dietary groups were no longer observed after stress. Conclusions: Our results suggest dietary replacement of fishmeal with PM can modulate European seabass acute stress response. For further insight into the impact of PM on fish robustness, other oxidative stress biomarkers and innate immunity parameters will be analyzed and discussed.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Ecological correlates and community-wide consequences of spider sociality
Creators: name: Guevara, Jennifer Carlota
Publisher: name: University of British Columbia
Year: 2012

description: Understanding the suite of ecological conditions that favor sociality —the tendency of organisms to form groups and cooperate— is key to understanding the origin, maintenance and contribution of social groups to biodiversity. The ecological dynamics of sociality can in turn have many consequences that feed back to influence the way species use the available resources, interact with other species, and persist in nature. The causes and consequences of sociality thus arise from the interplay of organisms and ecological processes. My thesis includes three studies that provide insight into some of the ecological processes that influence sociality and in turn the consequences that sociality may have in resource use and community structure. In the first study (Chapter 2), I use ecological niche modeling to predict the geographical distribution of social and subsocial New World Anelosimus spiders and explore their ecological correlates across latitude and elevation. Using a comparative approach, I further show that elevational patterns are strongly associated with differences in climatic conditions between social systems. In the next study (Chapter 3), I explore the role of group living and cooperation in resource use in a natural community of Anelosimus spiders of similar body size, but with behaviors ranging from near-solitary to fully social. I conduct surveys of prey capture in four sympatric Anelosimus species in Brazil and find that level of sociality and cooperation greatly shape resource use and act to separate different species into different ecological niches. Finally, I conduct feeding experiments to analyze in more detail the emergent patterns of resource use in two sympatric spiders with similar level of sociality but different body size (Chapter 4). I find that differences in resource use arise through differences in foraging efficiency emerging from the interplay of sociality and individual traits (e.g. body size). My thesis highlights the importance of ecological processes in the broad-scale spatial distribution of sociality and its potential consequences in resource use, community structure and ultimately the maintenance of local diversity. These studies also emphasize the work that remains to be done in such exciting area of research.
Spatial analytic approaches to explaining the trends and patterns of drug overdose deaths
Creators: name: DiMaggio, Charles J.
name: Bucciarelli, Angela
name: Tardiff, Kenneth J.
name: Vlahov, David
name: Galea, Sandro
Publisher: name: Columbia University
Year: 2008
Subjects: Public health

description: To effectively utilize and interpret spatial analyses, substance use researchers, public health practitioners and policy makers should be familiar with some of the available data analytic techniques, each of which comes with advantages and drawbacks. In this chapter we first discuss three cluster detection tools and their associated software applications. We then present a Bayesian hierarchical approach, briefly reviewing its theoretical underpinnings, commonly used models, and how inferences may be drawn a sample-based posterior distribution. We demonstrate the use of each approach on a set of substance abuse mortality data, comparing the results across the four tools. Our empiric illustration, considers the role of neighborhood-level socioeconomic status (SES) in explaining opiate-related overdose deaths in New York City. We end with a discussion of the implications of the choice of technique and software on interpreting spatial analyses of substance abuse and conclude that the choice of a method will be driven by the question to be answered, data and software availability and the intended audience or context in which the research is being conducted.
Probing Primordial Non-Gaussianity with Weak Lensing Minkowski Functionals
Creators: name: Shirasaki, Masato
name: Yoshida, Naoki
name: Hamana, Takashi
name: Nishimichi, Takahiro
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the cosmological information contained in the Minkowski Functionals (MFs) of weak gravitational lensing convergence maps. We show that the MFs provide strong constraints on the local type primordial non-Gaussianity parameter f_NL. We run a set of cosmological N-body simulations and perform ray-tracing simulations of weak lensing, to generate 100 independent convergence maps of 25 deg^2 field-of-view for f_NL = -100, 0 and 100. We perform a Fisher analysis to study the degeneracy among other cosmological parameters such as the dark energy equation of state parameter w and the fluctuation amplitude sigma_8. We use fully nonlinear covariance matrices evaluated from 1000 ray-tracing simulations. For the upcoming wide-field observations such as Subaru Hyper Suprime-Cam survey with the proposed survey area of 1500 deg^2, the primordial non-Gaussianity can be constrained with a level of f_NL ~ 80 and w ~ 0.036 by weak lensing MFs. If simply scaled by the effective survey area, a 20000 deg^2 lensing survey using Large Synoptic Survey Telescope will give constraints of f_NL ~ 25 and w ~ 0.013. We show that these constraints can be further improved by a tomographic method using source galaxies in multiple redshift bins.
description: 12 pages, 3 figures, To appear in ApJ
IS THE ACCELERATED EXPANSION OF THE UNIVERSE RESPONSIBLE FOR THE EMERGENCE OF THE FINE-STRUCTURE CONSTANT (1/137)?
Creators: name: RECCHIA, ARCANGELO
Publisher: name: Zenodo
Year: 2025
Subjects: subject: Particle physics
subject: Physical cosmology
subject: Astrophysics
subject: Theoretical physics
subject: Atomic physics
subject: Quantum physics
subject: planck constant
subject: observable universe
subject: fine structure constant

description: In this contribution, it is shown how the fine-structure constant emerges when two systems interact, one of which, light, perceives the universe as static due to not experiencing the passage of time, while the other, matter, experiences accelerated expansion. In this way, the fine-structure constant can be related to the rate of expansion of the universe; α can be expressed through the ratio to the fourth power of the theoretical radius R(uT)=13.6-13.8 Gly of the universe to the measured radius R(uI) = 46.5 Gly. 

                                                                         α = (13,6 Gly/46,5 Gly)^4 = 1/137                                                      (1.21)

From the equation (1.21), it is clear that, since the rate of expansion of the universe has not remained constant over time, the value of the fine-structure constant must also have changed (unless there is over time a proportional variation of the speed of light c), as have other physical constants and quantities. This implies that physical laws have not remained unchanged throughout the history of the universe. Regarding the spatial variation of α, the issue is more complex and falls outside the scope of this work.
An Adaptive Kernel Layer Deep Neural Network for Remote Sensing Imageries
Creators: name: Al Shoura, Tariq
Publisher: name: Schulich School of Engineering
Year: 2022
Subjects: subject: Deep Learning
subject: Machine Learning
subject: Image Processing
subject: Remote Sensing Images
subject: Change Detection
subject: Computer Science
subject: Engineering

description: Convolutional neural networks in recent years have become wildly utilized for the various applications that deal with images, going through different architectures and development to improve their capabilities for features extraction in order to yield better results in deep learning methods. Since images are vital resources that are used to represent various sceneries; multi-temporal images are an important tool used to monitor the changes that happen to those sceneries, which is required for multiple fields such as urban planning and disaster assessment, and with the rapid development of technology, very high-resolution (VHR) images from various sources are now more available, requiring analysis of the convolutional networks for larger images, and further developments to enhance their performance, so that they can process the large amount of data and identify any changes more efficiently. This thesis proposes the utilization of adaptive kernels layer (AKL) in order to extract features from large images, where the layer has been designed to maximize spectral information while retaining the spatial resolution of the information, discussing the benefits gained from utilizing it, and comparing it to other popular feature selection methods in image change detection applications. This thesis also examines and provides models used to generate the change image by utilizing machine learning (ML) models, mainly convolutional neural networks (CNN) and long shortterm memory (LSTM).
Formation of Heavy Meson Bound States by Two Nucleon Pick-up Reactions
Creators: name: Ikeno, N.
name: Yamagata-Sekihara, J.
name: Nagahiro, H.
name: Jido, D.
name: Hirenzaki, S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We develop a model to evaluate the formation rate of the heavy mesic nuclei in the two nucleon pick-up reactions, and apply it to the $^6$Li target cases for the formation of heavy meson-$α$ bound states, as examples. The existence of the quasi-deuteron in the target nucleus is assumed in this model. It is found that the mesic nuclei formation in the recoilless kinematics is possible even for heavier mesons than nucleon in the two nucleon pick-up reactions. We find the formation rate of the meson-$α$ bound states can be around half of the elementary cross sections at the recoilless kinematics with small distortions.
description: 1 table, 10 figures, 8 pages
Improving the Performance of DNN-based Software Services using Automated Layer Caching
Creators: name: Abedi, Mohammadamin
Publisher: name: Schulich School of Engineering
Year: 2022
Subjects: subject: Software Performance
subject: Caching
subject: Deep Neural Networks
subject: Systems Performance
subject: Machine Learning
subject: Computer Science

description: Deep Neural Networks (DNNs) have become an essential component in many application domains including web-based services. A variety of these services require high throughput and (close to) real-time features, for instance, to respond or react to users' requests or to process a stream of incoming data on time. However, the trend in DNN design is toward larger models with many layers and parameters to achieve more accurate results. Although these models are often pre-trained, the computational complexity in such large models can still be relatively significant, hindering low inference latency. Implementing a caching mechanism is a typical software engineering solution for speeding up a service response time. However, traditional caching is often not suitable for DNN-based services. In this thesis, we propose an end-to-end automated solution to improve the performance of DNN-based services in terms of their computational complexity and inference latency. Our caching method adopts the ideas of self-distillation of DNN models and early exits. The proposed solution is an automated online layer caching mechanism that allows early exiting of a large model during inference time if the cache model in one of the early exits is confident enough for final prediction. One of the main contributions of this thesis is that we have implemented the idea as an online caching, meaning that the cache models do not need access to training data and perform solely based on the incoming data at run-time, making it suitable for applications using pre-trained models. Our experiments results on two downstream tasks (face and object classification) show that, on average, caching can reduce the computational complexity of those services up to 58\% (in terms of FLOPs count) and improve their inference latency up to 46\% with low to zero reduction in accuracy.
Economic assessment and optimization of forest biomass supply chain for heat generation in a district heating system
Creators: name: Akhtari, Shaghaygh
Publisher: name: University of British Columbia
Year: 2012

description: This research investigates the feasibility of exploiting local forest biomass for district heat generation in Williams Lake, BC. The objectives of this research are (1) to examine the economic viability of delivering forest biomass to the gate of a potential heating plant, and (2) to find a cost-optimized supply chain for delivering biomass to the plant. Considering the impact of biomass availability on the design of the supply chain and the required logistics in the system makes this study distinctive from the previous research. To achieve the first objective, the annual total delivery cost of biomass to the plant, namely the material, handling, processing, and transportation costs, was calculated for supply chain options with and without terminal storages. The results of the feasibility study showed that depending on the distance of source points to the plant, the delivery cost of woodchips to the plant ranged from $2.19 GJ⁻¹ to $2.87 GJ⁻¹. However, the gap between supply and demand in some months indicated that the direct flow of woodchips from source points to the plant would not be always possible. To meet the demand in months with biomass shortage, forest biomass should be stored in a terminal storage although this could increase the total annual cost to $6.59 GJ⁻¹. At the same time, transferring all the plant’s demand via terminal storage would not seem economical since in the months with more supply than demand and also with good accessibility to the collection areas, the direct flow is possible. Using a mix of direct and indirect flows might provide the opportunity to deliver forest biomass to the plant at a lower cost. A linear programming model was used to minimize the total annual cost and to determine the optimal flow of biomass to the heating plant. The optimization results revealed that the optimal flow of biomass would cost $2.62 GJ⁻¹, which is less expensive than the current delivery cost of natural gas to the plant ($6.39 GJ⁻¹). Therefore, the use of forest biomass for energy generation might be economical depending upon the capital and operating costs of the energy conversion facility.
Vortex Tubes of Turbulent Solar Convection
Creators: name: Kitiashvili, I. N.
name: Kosovichev, A. G.
name: Mansour, N. N.
name: Lele, S. K.
name: Wray, A. A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Computational Physics (physics.comp-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Investigation of the turbulent properties of solar convection is extremely important for understanding the multi-scale dynamics observed on the solar surface. In particular, recent high-resolution observations have revealed ubiquitous vortical structures, and numerical simulations have demonstrated links between vortex tube dynamics and magnetic field organization and have shown the importance of vortex tube interactions in the mechanisms of acoustic wave excitation on the Sun. In this paper we investigate the mechanisms of the formation of vortex tubes in highly-turbulent convective flows near the solar surface by using realistic radiative hydrodynamic LES simulations. Analysis of data from the simulations indicates two basic processes of vortex tube formation: 1) development of small-scale convective instability inside convective granules, and 2) a Kelvin-Helmholtz type instability of shearing flows in intergranular lanes. Our analysis shows that vortex stretching during these processes is a primary source of generation of small-scale vorticity on the Sun.
description: submitted to Physica Scripta, 15 pages, 10 figures
Hydrological Frequency Analysis under Nonstationary Conditions
Creators: name: Vidrio-Sahagún, Cuauhtémoc Tonatiuh
Publisher: name: Schulich School of Engineering
Year: 2022
Subjects: subject: Hydrology
subject: Statistics
subject: FOS: Mathematics
subject: Engineering
subject: Engineering--Civil

description: The hydrological frequency analysis (HFA) evaluates the recurrence of extreme flow and precipitation events and guides water-related management and risk assessment. The conventional HFA assumes stationarity in the underlying process. However, climate change and other changes in the watersheds may induce nonstationarity in hydrometeorological variables. Under nonstationary scenarios, the nonstationary HFA (NS-HFA) is the theoretical choice. To implement the NS-HFA with more confidence, further understanding of the impacts of nonstationarity on the analysis and advancements of the existing approaches are desired.This dissertation, therefore, aimed to improve the understanding of the HFA under nonstationarity and advance the NS-HFA applications by: (a) investigating the impacts of ignoring the nonstationarity of different patterns and degrees in the stationary HFA (S-HFA); (b) examining the association between the nonstationarity characteristics and estimated flood hazards; (c) improving the determination of the NS-HFA model by proposing a novel procedure based on the decomposition of nonstationary stochastic processes; (d) enhancing the computational efficiency and numerical stability of the profile likelihood (PL) method, which is theoretically superior to other available methods for quantifying the uncertainty in the NS-HFA; and (e) comprehensively assessing the use of the Metastatistical approach and its simplified version to advance the NS-HFA from the perspectives of fitting efficiency, accuracy, and uncertainty. The results demonstrated that: (a) neglecting the nonstationarity in the S-HFA would lead to decreasing the accuracy and increasing the uncertainty of the analysis; (b) the nonstationarity patterns and degrees are strongly associated with the hydrological hazards; (c) the proposed decomposition-based approach based upon the theoretical decomposition of nonstationary stochastic processes advances the model determination in the NS-HFA from both theoretical and practical perspectives; (d) the proposed methods, which incorporate the classical regula-falsi numerical method and the generalized maximum likelihood principle, effectively reduce the computational burden and numerical instability of the PL method, and consequently facilitate its practical applications; and (e) compared to the NS-HFA based on the generalized extreme value distribution, the use of the simplified Metastatistical approach yields improved performance from various perspectives. Therefore, this dissertation improved the understanding of the HFA and advanced the NS-HFA for real-world applications.
Comparative analysis of the toxicity profile of eleven consumer-relevant nanomaterials in human intestinal and placental barrier cells
Creators: name: Pires, J.
name: Moreira, L.
name: Teixeira, J. P.
name: Fraga, S.
Publisher: name: Scientific Letters
Year: 2023

description: Background: The growing number of items incorporating nanomaterials (NM) has prompted considerable concerns about human health and safety [1]. Metal nanoparticles, inorganic non-metallic, and carbon-based NM are among the types with the highest market volume [2]. Objective: The purpose of this study was to determine the effect of chemical composition [Ag, Au, TiO2, SiO2, and graphene oxide (nano_GO)], primary size (10, 30 and 60 nm AgNP and AuNP), crystal structure (TiO2NP rutile/anatase and anatase), and surface coating (citrate and PEGylated AuNP) on potential toxicity to human intestinal (Caco-2) and placental (BeWo b30) epithelial cells. Methods: Changes in cell morphology, metabolic activity, plasma membrane integrity, intracellular ROS and ATP levels, and DNA integrity were assessed to investigate their potential toxicity at 24 h after exposure. Results: In both barrier models, the toxicity profile was similar, however placentalwere more sensitive than intestinal epithelial cells. Overall, NM may be ranked for cytotoxicity as AgNP > nano_GO > AuNP ~ TiO2NP ~ SiO2NP, with the effects becoming more evident at greater concentrations. The influence of size was more pronounced for AgNP than for AuNP, with the smaller nanoparticles producing higher cytotoxic effects. The cytotoxicity of AuNP was prevented by PEG capping. AgNP and nano_GO exposure markedly raised the levels of ROS, indicating that oxidative stress may play a role in their cytotoxicity. Except for 10 nm AuNP, every NM tested markedly increased intracellular ATP levels. One interesting finding was that a higher cytotoxic potential did not necessarily equate to a higher genotoxic potential, since only AgNP (classified as positive) and anatase TiO2NP (classified as equivocal) caused DNA damage. Conclusions: Our findings alert to the potential risks associated with human barriers exposure to NM, where the physicochemical properties are important determinants of their toxicity. Additional research is needed for a deeper understanding of NM impact on human barriers.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)
Study of metal presence in the sediments of three different water bodies from the north of Portugal and its impact in Archaeal community
Creators: name: Torre, R.
name: Pinto, I.
name: Lage, O. M.
name: Noyer, M.
name: Almeida, E.
name: Cravo-Laureau, C.
name: Duran, R.
name: Antunes, S. C.
name: Catita, J.
Publisher: name: Scientific Letters
Year: 2023

description: Background: Human impact on the planet’s biomes has been rapidly increasing over the last decades [1]. In aquatic ecosystems, an active monitoring of the water and the sediments quality is already essential to assure its suitability for human use as well as to guarantee the health of the ecosystems [2, 3]. Objectives: This work focuses on the study of metals concentration in transitional water bodies (Ave estuary – 2 sites, Douro estuary – 3 sites; and Ria de Aveiro – 3 sites), and in the establishment of correlations with parameters to assess ecosystem’s health based on the analysis of the less studied domain, the Archaea. Methods: Sediment samples were collected from the three target ecosystems. Metals concentration (Cu, Mn, Ni, Zn, Pb, Cr, Cd, As) was determined by flame atomic absorption and Archaea profiling was performed by 16S rRNA gene sequencing. The database was normalized for statistical analysis, namely for univariate (correlation matrix), and multivariate analysis (PCA, HCA). Results: The characterization of Archaeal community revealed the presence of 12 phyla (and several unidentified sequences). Regarding metals, Ave2 (upstream), showed high values of Cu, Mn, Zn, Cr and As, in Douro sites Cu, Mn, Zn and As were detected while in Ria de Aveiro As was the most abundant metal. Higher microbial Amplicon Sequence Variant (ASV) richness and Shannon's diversity index are related to the three sites of Ria de Aveiro, including a saltern site (≈55 PSU), which is the more extreme environment of all the sampling locations. The statistical analysis showed that in general, metals negatively affected the biodiversity of Archaeal community, with copper and chromium being the most relevant. Conclusions: The archaeal community in these target ecosystems is influenced by the metals present in their sediments.
description: Scientific Letters, Vol. 1 No. Sup 1 (2023)