cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Post-perihelion volatile production and release from Jupiter-family comet 45P/Honda-Mrkos-Pajdušáková
Creators: name: Dello Russo, Neil
name: Kawakita, Hideyo
name: Bonev, Boncho
name: Vervack, Jr., Ronald J.
name: Gibb, Erika L.
name: Shinnaka, Yoshiharu
name: Roth, Nathan X.
name: DiSanti, Michael A.
name: McKay, Adam
Publisher: name: American University
Year: 2023

description: High-resolution infrared spectra of Jupiter-family comet 45P/Honda-Mrkos-Pajdušáková were obtained with NIRSPEC at the W. M. Keck Observatory on two post-perihelion dates (UT 2017 February 13 and 19), when the comet was at heliocentric distances of 1.01 and 1.10 AU, respectively. On UT February 13, H2O was measured simultaneously with six trace parent molecules: CH3OH, C2H6, HCN, NH3, C2H2, and H2CO. On UT February 19, CH4 and CO were also targeted in addition to the species measured on UT February 13. Abundances of CO, CH4, and C2H2 relative to H2O are consistent with values obtained from IRTF/iSHELL observations of 45P in early January 2017 just after perihelion when the heliocentric distance was 0.55–0.56 AU. Differences are seen in H2CO/H2O, C2H6/H2O, CH3OH/H2O, and HCN/H2O in February compared to January. Additionally, NH3 abundances appear highly variable during the February measurements, suggesting possible fluctuations of a factor of ten; however, there is significant uncertainty in quantifying NH3 owing to the marginal detections of only one or two lines on each of the two dates. Combining all infrared spectroscopic observations of 45P in January and February 2017, a post-perihelion relationship of Q(H2O) = (2.81 ± 0.25) × 1027 [Rh (−3.83±0.18)] molecules s−1 is derived. However, all measurements suggest significant variability in H2O production on timescales of hours and days. Compared to other comets, volatile abundances relative to H2O in 45P are as follows: CO (depleted relative to all measured comets), CH3OH (enriched/all comets), CH4 and C2H6 (typical/all comets, enriched/Jupiter-family comets), C2H2 (depleted/all comets, typical/Jupiter-family comets), H2CO (January: typical, February depleted/all comets), HCN (January: severely depleted, February: typical/Jupiter-family comets). The small geocentric distances of the comet in February 2017 provide high spatial resolution in the coma of 45P (~12 and 19 km/pixel on February 13 and 19, respectively). Overall, the spatial distributions of volatiles and dust suggest a relatively symmetric and uniform coma during the UT February 13 and 19 observations, with small spatial differences noted between some volatile species. Measured C2H2 and HCN abundances are consistent with HCN as the primary parent of CN and C2H2 as a significant but not primary parent for C2, based on C2 and CN production rate measurements from the 2017 and previous apparitions. Extracted spectra show an increase in the dust-to-gas ratio in 45P from February 13 to 19 in agreement with contemporaneous narrowband optical measurements.
Adiabatic ground state preparation in an expanding lattice
Creators: name: Olund, Christopher T.
name: Block, Maxwell
name: Gazit, Snir
name: McGreevy, John
name: Yao, Norman Y.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We implement and characterize a numerical algorithm inspired by the $s$-source framework [Phys. Rev.~B 93, 045127 (2016)] for building a quantum many-body ground state wavefunction on a lattice of size $2L$ by applying adiabatic evolution to the corresponding ground state at size $L$, along with $L$ interleaved ancillae. The procedure can in principle be iterated to repeatedly double the size of the system. We implement the algorithm for several one dimensional spin model Hamiltonians, and find that the construction works particularly well when the gap is large and, interestingly, at scale invariant critical points. We explain this feature as a natural consequence of the lattice expansion procedure. This behavior holds for both the integrable transverse-field Ising model and non-integrable variations. We also develop an analytic perturbative understanding of the errors deep in either phase of the transverse field Ising model, and suggest how the circuit could be modified to parametrically reduce errors. In addition to sharpening our perspective on entanglement renormalization in 1D, the algorithm could also potentially be used to build states experimentally, enabling the realization of certain long-range correlated states with low depth quantum circuits.
description: 14 pages, 6 figures
Fluctuation Formula in the Nose-Hoover thermostated Lorentz gas
Creators: name: Dolowschiak, M.
name: Kovacs, Z.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: In this paper we examine numerically the Gallavotti-Cohen fluctuation formula for phase-space contraction rate and entropy production rate fluctuations in the Nosé-Hoover thermostated periodic Lorentz gas. Our results indicate that while the phase-space contraction rate fluctuations violate the fluctuation formula near equilibrium states, the entropy production rate fluctuations obey this formula near and far from equilibrium states as well.
description: 4 pages, 8 figures
Postkarten sind in! - Wollishofer Blog
Creators: name: Brändli, Sebastian
Publisher: name: Zentralbibliothek Zürich
Year: 2021
Subjects: subject: 760 Grafik, Druckgrafik, Drucke
subject: Zürich-Wollishofen
subject: Postkarte

description: Ein Blog zu Geschichte und Quartierleben des Zürcher Stadtquartiers Wollishofen auf wollipedia.ch. Mit Texten von Sebastian Brändli (SB) und Ansichtskarten aus der Sammlung von Markus Zimmermann (MZ).
Supplementary Material from The relevance of gene flow with wild relatives in understanding the domestication process
Creators: name: Moreno-Letelier, Alejandra
name: Jonás .A. Aguirre-Liguori
name: Piñero, Daniel
name: Vázquez-Lobo, Alejandra
name: Eguiarte, Luis E.
Publisher: name: The Royal Society
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Evolutionary Biology
subject: Plant Biology

description: Supplementary figures S1-S5
On the large $D$ expansion of Hermitian multi-matrix models
Creators: name: Carrozza, Sylvain
name: Ferrari, Frank
name: Tanasa, Adrian
name: Valette, Guillaume
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We investigate the existence and properties of a double asymptotic expansion in $1/N^{2}$ and $1/\sqrt{D}$ in $\mathrm{U}(N)\times\mathrm{O}(D)$ invariant Hermitian multi-matrix models, where the $N\times N$ matrices transform in the vector representation of $\mathrm{O}(D)$. The crucial point is to prove the existence of an upper bound $η(h)$ on the maximum power $D^{1+η(h)}$ of $D$ that can appear for the contribution at a given order $N^{2-2h}$ in the large $N$ expansion. We conjecture that $η(h)=h$ in a large class of models. In the case of traceless Hermitian matrices with the quartic tetrahedral interaction, we are able to prove that $η(h)\leq 2h$; the sharper bound $η(h)=h$ is proven for a complex bipartite version of the model, with no need to impose a tracelessness condition. We also prove that $η(h)=h$ for the Hermitian model with the sextic wheel interaction, again with no need to impose a tracelessness condition.
description: 28 pages, 20 figures; v2: refs added, matches published version
Effects of Fluctuations on Propagating Fronts
Creators: name: Panja, Debabrata
Publisher: name: arXiv
Year: 2003
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Propagating fronts are seen in varieties of non-equilibrium pattern forming systems in Physics, Chemistry and Biology. In the last two decades, many researchers have contributed to the understanding of the underlying dynamics of the propagating fronts. Of these, the deterministic and mean-field dynamics of the fronts were mostly understood in late 1980s and 1990s. On the other hand, although the earliest work on the effect of fluctuations on propagating fronts dates back to early 1980s, the subject of fluctuating fronts did not reach its adolescence until the mid 1990s. From there onwards the last few years witnessed a surge in activities in the effect of fluctuations on propagating fronts. Scores of papers have been written on this subject since then, contributing to a significant maturity of our understanding, and only recently a full picture of fluctuating fronts has started to emerge. This review is an attempt to collect all the works on fluctuating (propagating) fronts in a coherent and cogent manner in proper perspective. It is based on the idea of making our knowledge in this field available to a broader audience, and it is also expected to help to collect bits and pieces of loose thread-ends together for possible further investigation.
description: Review article, minor changes, references updated, 114 pages, 37 figures, to appear in Physics Reports
Mukhanov-Sasaki equation in manifestly gauge-invariant linearized cosmological perturbation theory with dust reference fields
Creators: name: Giesel, Kristina
name: Herold, Laura
name: Li, Bao-Fei
name: Singh, Parampreet
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The aim of this article is to understand the role of dust reference fields, often also called clocks, on cosmological perturbations around a flat FLRW universe. We derive the Mukhanov-Sasaki (MS) equation for the Brown-Kuchar (BK) and Gaussian dust models, which both consider four dust fields as reference fields. The reduced phase space of Dirac observables, that is the gauge-invariant part of the theory, is constructed by means of an observable map applied to all elementary phase space variables of the coupled system, consisting of gravity, a massive scalar field and the dust degrees of freedom. The evolution of these observables is governed by a so called physical Hamiltonian which can be derived once the set of reference fields are chosen and differs for each model. First, the reduced phase space as well as the corresponding equations of motion are derived for full general relativity. Then from this, the gauge-invariant version of the equations of motion for the background are derived which contain a fingerprint of the dust reference fields. Afterwards we study linear cosmological perturbations around a FLRW metric using the scalar-vector-tensor decomposition and derive the equation of motion for the MS variable in this formalism for a chosen set of variables on the reduced phase space and expressed in terms of Dirac observables. The MS equation involves additional contributions that can be understood as back reactions from the dust reference fields. These additional dust contributions to the MS equation were absent if the dust energy and momentum density as well as their perturbations are vanishing. The nature of the correction terms suggest that BK and Gaussian dust reference fields contribute differently. Using numerical simulations we study the behavior of the dust contributions to the MS equation during inflation.
description: Revised version. Analysis and comparison of two dust models extended to investigate Mukhanov-Sasaki variable with now corrected contribution for Brown-Kuchar model. Figures added and updated. To appear in Phys. Rev. D
Formal report : an investigation into biodiesel production on UBC campus
Creators: name: Alemzadeh, Arian
name: Graebel, Derek
name: Lau, Brandon
Publisher: name: The University of British Columbia
Year: 2014

description: Biodiesel has been produced on campus since 2002 and has contributed to reductions in discarded waste vegetable oil and Plant Operations vehicle emissions to varying degrees. Current biodiesel production has been limited to 500L a year due to lack of funding, and use of UBC-produced biodiesel by Plant Operations has not been as high as in previous years. This report addresses the subject of biodiesel production and consumption on campus; specifically, it details the social, economic, and environmental benefits of the use of biodiesel as part of a triple bottom line analysis. The scope of this project and its recommendations are based on the University of British Columbia campus. The findings and recommendations proposed in this report are based on both primary and secondary research. Stakeholders such as UBC Plant Operations representative Adam McCluskey, Vancouver Biodiesel Co-op Vice President Lucas Closs, and Chemical and Biological Engineering professor Dr. Naoko Ellis were all consulted in the research process. Economic indicators and projections were found to be promising. With an available WVO feedstock requiring minimal transportation, and the projections of a positive NPV, it can be concluded that the project is economically viable. Biodiesel was found to produce lower emissions in virtually all categories, notably those that affect human health. Biodiesel was also deemed compatible with Plant Operations vehicles, and can lubricate and reduce the noise level of the engines. The operation would allow the university to capitalize on the social benefits realized by the Vancouver Biodiesel Co-op, including opportunities for research and outreach programs. The recommendation is to proceed with the campus biodiesel operation. Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”
Supplementary Tables from The relevance of gene flow with wild relatives in understanding the domestication process
Creators: name: Moreno-Letelier, Alejandra
name: Jonás .A. Aguirre-Liguori
name: Piñero, Daniel
name: Vázquez-Lobo, Alejandra
name: Eguiarte, Luis E.
Publisher: name: The Royal Society
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Evolutionary Biology
subject: Plant Biology

description: Maize and teosinte accession information
Post-perihelion volatile production and release from Jupiter-family comet 45P/Honda-Mrkos-Pajdušáková
Creators: name: Dello Russo, Neil
name: Kawakita, Hideyo
name: Bonev, Boncho
name: Vervack, Jr., Ronald J.
name: Gibb, Erika L.
name: Shinnaka, Yoshiharu
name: Roth, Nathan X.
name: DiSanti, Michael A.
name: McKay, Adam
Publisher: name: Icarus
Year: 2023
Subjects: classificationCode: 51
subject: Physical sciences
subject: FOS: Physical sciences

description: High-resolution infrared spectra of Jupiter-family comet 45P/Honda-Mrkos-Pajdušáková were obtained with NIRSPEC at the W. M. Keck Observatory on two post-perihelion dates (UT 2017 February 13 and 19), when the comet was at heliocentric distances of 1.01 and 1.10 AU, respectively. On UT February 13, H2O was measured simultaneously with six trace parent molecules: CH3OH, C2H6, HCN, NH3, C2H2, and H2CO. On UT February 19, CH4 and CO were also targeted in addition to the species measured on UT February 13. Abundances of CO, CH4, and C2H2 relative to H2O are consistent with values obtained from IRTF/iSHELL observations of 45P in early January 2017 just after perihelion when the heliocentric distance was 0.55–0.56 AU. Differences are seen in H2CO/H2O, C2H6/H2O, CH3OH/H2O, and HCN/H2O in February compared to January. Additionally, NH3 abundances appear highly variable during the February measurements, suggesting possible fluctuations of a factor of ten; however, there is significant uncertainty in quantifying NH3 owing to the marginal detections of only one or two lines on each of the two dates. Combining all infrared spectroscopic observations of 45P in January and February 2017, a post-perihelion relationship of Q(H2O) = (2.81 ± 0.25) × 1027 [Rh (−3.83±0.18)] molecules s−1 is derived. However, all measurements suggest significant variability in H2O production on timescales of hours and days. Compared to other comets, volatile abundances relative to H2O in 45P are as follows: CO (depleted relative to all measured comets), CH3OH (enriched/all comets), CH4 and C2H6 (typical/all comets, enriched/Jupiter-family comets), C2H2 (depleted/all comets, typical/Jupiter-family comets), H2CO (January: typical, February depleted/all comets), HCN (January: severely depleted, February: typical/Jupiter-family comets). The small geocentric distances of the comet in February 2017 provide high spatial resolution in the coma of 45P (~12 and 19 km/pixel on February 13 and 19, respectively). Overall, the spatial distributions of volatiles and dust suggest a relatively symmetric and uniform coma during the UT February 13 and 19 observations, with small spatial differences noted between some volatile species. Measured C2H2 and HCN abundances are consistent with HCN as the primary parent of CN and C2H2 as a significant but not primary parent for C2, based on C2 and CN production rate measurements from the 2017 and previous apparitions. Extracted spectra show an increase in the dust-to-gas ratio in 45P from February 13 to 19 in agreement with contemporaneous narrowband optical measurements.
The Pragmatic Turn in Explainable Artificial Intelligence (XAI)
Creators: name: Páez, Andrés
Publisher: name: arXiv
Year: 2020
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computers and Society (cs.CY)
subject: Human-Computer Interaction (cs.HC)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: In this paper I argue that the search for explainable models and interpretable decisions in AI must be reformulated in terms of the broader project of offering a pragmatic and naturalistic account of understanding in AI. Intuitively, the purpose of providing an explanation of a model or a decision is to make it understandable to its stakeholders. But without a previous grasp of what it means to say that an agent understands a model or a decision, the explanatory strategies will lack a well-defined goal. Aside from providing a clearer objective for XAI, focusing on understanding also allows us to relax the factivity condition on explanation, which is impossible to fulfill in many machine learning models, and to focus instead on the pragmatic conditions that determine the best fit between a model and the methods and devices deployed to understand it. After an examination of the different types of understanding discussed in the philosophical and psychological literature, I conclude that interpretative or approximation models not only provide the best way to achieve the objectual understanding of a machine learning model, but are also a necessary condition to achieve post-hoc interpretability. This conclusion is partly based on the shortcomings of the purely functionalist approach to post-hoc interpretability that seems to be predominant in most recent literature.
Analysis of the chargino and neutralino mass parameters at one-loop level
Creators: name: Oeller, W.
name: Eberl, H.
name: Majerotto, W.
name: Weber, C.
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the Minimal Supersymmetric Standard Model (MSSM) the masses of the neutralinos and charginos depend on the gaugino and higgsino mass parameters M, M' and $μ$. If supersymmetry is realized, the extraction of these parameters from future high energy experiments will be crucial to test the underlying theory. We present a consistent method how on-shell parameters can be properly defined at one-loop level and how they can be determined from precision measurements. In addition, we show how a GUT relation for the parameters M and M' can be tested at one-loop level. The numerical analysis is based on a complete one-loop calculation. The derived analytic formulae are given in the appendix.
description: 16 pages, 8 figures
BEYOND4.0 Policy Brief #5 Understanding Technological Revolutions
Creators: name: Perez Carlota
name: Tamsin, Murray Leach
Publisher: name: Zenodo
Year: 2021
Subjects: industry4.0 ditital transformation technological revolution

description: This Policy Brief focuses on the different ways in which technological revolutions have been studied and understood historically. While some attempts have been made to outline definitive historical periods with categorical empirical evidence, they have not produced tight conclusions. This Policy Brief is different. It summarises the study of economic cycles and the history of previous transformations and critically outlines the benefits and limitations of essentially conceptual frameworks. It proposes complementing Schwab's ‘4th Industrial Revolution’ approach with the neo-Schumpeterian scholarship, which highlights the crucial role that governments play in the successful deployment of new socio-technical systems. At the same time, it offers recommendations for policymakers on how to understand the past so that policy can be better designed to ensure that the new technologies deliver a socially and environmentally sustainable future.
Hybrid Deep Learning for Detecting Lung Diseases from X-ray Images
Creators: name: Bharati, Subrato
name: Podder, Prajoy
name: Mondal, M. Rubaiyat Hossain
Publisher: name: arXiv
Year: 2020
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Lung disease is common throughout the world. These include chronic obstructive pulmonary disease, pneumonia, asthma, tuberculosis, fibrosis, etc. Timely diagnosis of lung disease is essential. Many image processing and machine learning models have been developed for this purpose. Different forms of existing deep learning techniques including convolutional neural network (CNN), vanilla neural network, visual geometry group based neural network (VGG), and capsule network are applied for lung disease prediction.The basic CNN has poor performance for rotated, tilted, or other abnormal image orientation. Therefore, we propose a new hybrid deep learning framework by combining VGG, data augmentation and spatial transformer network (STN) with CNN. This new hybrid method is termed here as VGG Data STN with CNN (VDSNet). As implementation tools, Jupyter Notebook, Tensorflow, and Keras are used. The new model is applied to NIH chest X-ray image dataset collected from Kaggle repository. Full and sample versions of the dataset are considered. For both full and sample datasets, VDSNet outperforms existing methods in terms of a number of metrics including precision, recall, F0.5 score and validation accuracy. For the case of full dataset, VDSNet exhibits a validation accuracy of 73%, while vanilla gray, vanilla RGB, hybrid CNN and VGG, and modified capsule network have accuracy values of 67.8%, 69%, 69.5%, 60.5% and 63.8%, respectively. When sample dataset rather than full dataset is used, VDSNet requires much lower training time at the expense of a slightly lower validation accuracy. Hence, the proposed VDSNet framework will simplify the detection of lung disease for experts as well as for doctors.
description: 13 figures
Reaching optimally oriented molecular states by laser kicks
Creators: name: Sugny, D.
name: Keller, A.
name: Atabek, O.
name: Daems, D.
name: Dion, C. M.
name: Guérin, S.
name: Jauslin, H. R.
Publisher: name: arXiv
Year: 2003
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a strategy for post-pulse orientation aiming both at efficiency and maximal duration within a rotational period. We first identify the optimally oriented states which fulfill both requirements. We show that a sequence of half-cycle pulses of moderate intensity can be devised for reaching these target states.
description: 4 pages, 3 figures
RELATIONSHIP BETWEEN HUMAN AND NATURE.docx
Creators: name: Hammed AYANSOLA
Publisher: name: figshare
Year: 2020
Subjects: subject: 50206 Environmental Monitoring
subject: FOS: Earth and related environmental sciences

description: Since the creation of the earth, nature has shaped human life in various ways, such as food, clothing, and shelter. On the other hand, man has lived from the agrarian period with the aid of his intellect and invention through the industrial age to this technological progress we are seeing in the world today. Undoubtedly, a long-lasting relationship has established, resulting in the natural selection of man and his environment. Over the years, however, history has shown that the relationship is loop-sided and unsustainable, implying that man's existence on earth disrupts the natural ecosystem. It is, therefore, important that we consider the intricacy of the relationship between man and nature.
Extended Results and Methods and Supporting Figures and Tables from Craniofacial development illuminates the evolution of nightbirds (Strisores)
Creators: name: Navalón, Guillermo
name: Nebreda, Sergio M.
name: Bright, Jen A.
name: Fabbri, Matteo
name: Benson, Roger B. J.
name: Bhullar, Bhart-Anjan
name: Marugán-Lobón, Jesús
name: Rayfield, Emily J.
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 60114 Systems Biology
subject: 40308 Palaeontology (incl. Palynology)
subject: FOS: Earth and related environmental sciences

description: Information important to understand the results and discussion derived from them
Bas Jan Ader : The Romantic Hero and Conceptual Art
Creators: name: Wilson, Lillian
name: Langa, Helen
Publisher: name: American University (Washington, D.C.)
Year: 2023
Subjects: classificationCode: 3601
subject: Art history, theory and criticism

description: Research paper submitted to American University in partial fulfillment of the Degree of Master of Arts; approved as non-thesis option
Directed-loop Monte Carlo simulations of vertex models
Creators: name: Syljuasen, Olav F.
name: Zvonarev, M. B.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We show how the directed-loop Monte Carlo algorithm can be applied to study vertex models. The algorithm is employed to calculate the arrow polarization in the six-vertex model with the domain wall boundary conditions (DWBC). The model exhibits spatially separated ordered and ``disordered'' regions. We show how the boundary between these regions depends on parameters of the model. We give some predictions on the behavior of the polarization in the thermodynamic limit and discuss the relation to the Arctic Circle theorem.
description: Extended version with autocorrelations and more figures. Added 2 references
Comment on "Continuous quantum measurement: inelastic tunneling and lack of current oscillations"
Creators: name: Averin, Dmitri V.
name: Korotkov, Alexander N.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: This is a comment on recent paper by T.M. Stace and S.D. Barrett, PRL 92, 136802 (2004). We show that the main result of the paper, absence of the spectral peak for continuous weak measurement of coherent oscillations in a qubit, is incorrect.
description: 2 pages, no figures
Antimicrobial Activities, phytochemical composition and thin layer chromatography profile of Gossypium hirsutum and Abelmoschus esculentus leaves extracts
Creators: name: Attama, Chika
name: Lawrence, Luka
name: Segun, Olanipekun Gabriel
Publisher: name: Journal of Natural Products Discovery
Year: 2024

description: Background: This study evaluates the antimicrobial activities, phytochemical composition, and thin layer chromatography (TLC) profile of ethanolic and aqueous leaf extracts of Gossypium hirsutum L. and Abelmoschus esculentus (L.) Moench.

Aims: The objective is to investigate the phytochemical constituents and assess the antimicrobial efficacy of these plant extracts against various pathogenic microorganisms.

Methods: Leaves were collected, identified, air-dried, and powdered. Ethanolic and aqueous extracts were prepared and subjected to TLC analysis using silica gel plates and a mobile phase of ethanol, methanol, and ethyl acetate (5:3:2). Phytochemical screening was conducted using standard protocols. Antimicrobial activity was evaluated using the agar well diffusion method against pathogens including Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Proteus, Streptococcus pneumoniae and Candida spp.

Results: TLC analysis revealed seven compounds in G. hirsutum and six in Abelmoschus esculentus with distinct Rf values. Phytochemical screening identified phenols/tannins, saponins, flavonoids, reducing sugars, terpenoids, and anthraquinones in G. hirsutum, while A. esculentus contained all tested phytochemicals except phytosterol and essential oil. The antimicrobial assay indicated that ethanolic extracts of both plants exhibited significant antibacterial activity, with G. hirsutum showing higher efficacy. Ethanolic extracts of G. hirsutum inhibited S. aureus and S. typhi effectively, while aqueous extracts showed limited activity. Extracts of A. esculentus leaves inhibited all tested organisms except Proteus, with ethanol extracts also ineffective against S. pneumoniae.

Conclusion: The study demonstrates that ethanolic extracts of G. hirsutum and A. esculentus possess antimicrobial properties. These findings support the potential use of these plant extracts in developing natural antimicrobial agents.
description: Journal of Natural Products Discovery, Vol. 3 No. 2 (2024): Journal of Natural Products Discovery - Issue on ‘Natural products from eukaryotic and prokaryotic cells’
Zero density heavy quark SU(2) gauge theory and the Stefan-Boltzmann limit
Creators: name: Langfeld, Kurt
name: Lages, Norbert
name: Reinhardt, Hugo
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: SU(2) lattice gauge theory is investigated where the traces of the Wilson lines at any lattice point and along each direction is constrained to zero. Hence, each of the lattice configurations possesses a vanishing density of heavy (anti-) quarks. The results are compared with those of pure SU(2) gauge theory which can be interpreted as the grand canonical realization of the heavy quark theory where only the ensemble average of the heavy quark density vanishes. The static quark anti-quark potential of the constrained theory is obtained from (spatially smeared) Wilson loops at zero temperature. We find that the potential coincides with that of pure SU(2) gauge theory (without constraints). Hence, the familiar "running" of the lattice spacing with beta is recovered.
description: presented at Lattice2005(Nonzero temperature and density), Dublin, July 25-30, 2005, 6 pages, 4 figures, to appear in Proceedings of Science
Predictive power of transverse-momentum-dependent distributions
Creators: name: Grewal, Manvir
name: Kang, Zhong-Bo
name: Qiu, Jian-Wei
name: Signori, Andrea
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate the predictive power of transverse-momentum-dependent (TMD) distributions as a function of the light-cone momentum fraction $x$ and the hard scale $Q$ defined by the process. We apply the saddle point approximation to the unpolarized quark and gluon transverse momentum distributions and evaluate the position of the saddle point as a function of the kinematics. We determine quantitatively that the predictive power for an unpolarized transverse momentum distribution is maximal in the large-$Q$ and small-$x$ region. For cross sections the predictive power of the TMD factorization formalism is generally enhanced by considering the convolution of two distributions, and we explicitly consider the case of $Z$ and $H^0$ boson production. In the kinematic regions where the predictive power is not maximal, the distributions are sensitive to the non-perturbative hadron structure. Thus, these regions are critical for investigating hadron tomography in a three-dimensional momentum space.
description: 25 pages - published version
Supplementary Dataset 2. from Craniofacial development illuminates the evolution of nightbirds (Strisores)
Creators: name: Navalón, Guillermo
name: Nebreda, Sergio M.
name: Bright, Jen A.
name: Fabbri, Matteo
name: Benson, Roger B. J.
name: Bhullar, Bhart-Anjan
name: Marugán-Lobón, Jesús
name: Rayfield, Emily J.
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 60114 Systems Biology
subject: 40308 Palaeontology (incl. Palynology)
subject: FOS: Earth and related environmental sciences

description: A) List of CT-scanned specimens and scanner settings. C) Incubation, fledgling periods and feather morphology variation along postnatal growth in selected taxa. *At the end of the fledgling period birds generally attain their adult plumage. All the ontogenetic information is sourced from Del Hoyo et al., [2].
Sustainability project : investigating a replacement for disposable chopsticks
Creators: name: Anderson, James
name: Gong, Apple
name: Zhi, Li
Publisher: name: The University of British Columbia
Year: 2014

description: Forests are overexploited for many purposes (food, medicine, shelter, and commercial use). Every year, 25 million trees a year are cut down in China or around 100 acres every 24 hours. Deforestation has led to environmental crises such as soil erosion, flooding, landslides, foot shortages, carbon dioxide abundance, and the extinction of species. One of the main contributors to this deforestation is the mass production of disposable wooden chopsticks. An astonishing 57 billion pairs of these chopsticks are produced annually in China alone, the equivalent of about 3.8 million trees. People are using these chopsticks because they are the least expensive option, and they are not recycling them because it costs more to do so than it does to throw them away. UBC has committed to their vision of sustainability. As a consequence of the new Student Union Building being developed at UBC, there has arisen an opportunity to install a vending machine filled with sustainable products to help UBC students strive towards this vision. Reusable chopsticks are such a product, and it is with this in mind that a triple-bottom line analysis was conducted to determine the expectation and viability of such an endeavor. Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”
RESEARCH NOTE: THE OPPORTUNITY COST OF WATER FOR ENVIRONMENTAL USE DURING WATER SHORTAGES WITH REFERENCE TO THE VAAL RIVER SYSTEM
Creators: name: Viljoen, M. F.
name: Viljoen, M. F.
Publisher: name: Unknown
Year: 1994
Subjects: Environmental Economics and Policy
Resource /Energy Economics and Policy

description: Optimal utilisation of water means inter alia that it must be allocated to the different uses/users in such a way that the welfare of the community will be enhanced maximally. Necessary information for pursuing optimal allocation is knowledge about the value of water in different uses. An indirect method, the opportunity cost/alternative value method, is applied to assess the value of water for environmental use during a period of water scarcity.
Direct measurement of the size and shape of the present-day stellar wind of Eta Carinae
Creators: name: van Boekel, R.
name: Kervella, P.
name: Schoeller, M.
name: Herbst, T.
name: Brandner, W.
name: Waters, L. B. F. M.
name: Hillier, D. J.
name: Paresce, F.
name: Lenzen, R.
name: Lagrange, A. -M.
Publisher: name: arXiv
Year: 2003
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present new high angular resolution observations at near-IR wavelengths of the core of the Luminous Blue Variable Eta Carinae, using NAOS-CONICA at the VLT and VINCI at the VLT Interferometer (VLTI). The latter observations provide spatial information on a scale of 5 milli-arcsec or ~11 AU at the distance of Eta Carinae. The present-day stellar wind of Eta Carinae is resolved on a scale of several stellar radii. Assuming spherical symmetry, we find a mass loss rate of 1.6x10^{-3} M_sun/yr and a wind clumping factor of 0.26. The VLTI data taken at a baseline of 24 meter show that the object is elongated with a de-projected axis ratio of approximately 1.5; the major axis is aligned with that of the large bi-polar nebula that was ejected in the 19th century. The most likely explanation for this observation is a counter-intuitive model in which stellar rotation near the critical velocity causes enhanced mass loss along the rotation axis. This results from the large temperature difference between pole and equator in rapidly rotating stars. Eta Carinae must rotate in excess of 90 per cent of its critical velocity to account for the observed shape. The large outburst may have been shaped in a similar way. Our observations provide strong support for the existence of a theoretically predicted rotational instability, known as the Omega limit.
description: 5 pages, 3 figures, accepted for publication in A&A letters
New class of hybrid metric-Palatini scalar-tensor theories of gravity
Creators: name: Borowiec, Andrzej
name: Kozak, Aleksander
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A class of scalar-tensor theories (STT) including a non-metricity that unifies metric, Palatini and hybrid metric-Palatini gravitational actions with non-minimal interaction is proposed and investigated from the point of view of their consistency with generalized conformal transformations. It is shown that every such theory can be represented on-shell by a purely metric STT possessing the same solutions for a metric and a scalar field. A set of generalized invariants is also proposed. This extends the formalism previously introduced in \cite{kozak2019}. We then apply the formalism to Starobinsky model, write down the Friedmann equations for three possible cases: metric, Palatini and hybrid metric-Palatini, and compare some inflationary observables.
description: 34 pages in LaTeX, comments and references added, final version published in JCAP
Theoretical model of the phi meson photoproduction amplitudes
Creators: name: Lesniak, L.
name: Szczepaniak, A. P.
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: P-wave amplitudes for elastic K+ K- photoproduction on hydrogen near the phi(1020) resonance have been derived in an analytical form and a partial wave decomposition of the amplitudes has been performed. We discuss the high energy limit of the resulting amplitudes and compare two types of pomeron coupling to nucleons.
description: 13 pages, Latex, to appear in Acta Physica Polonica B
A_4 Symmetry and Neutrinos with Very Different Masses
Creators: name: Ma, Ernest
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The A_4 model of leptons was proposed originally for nearly degenerate neutrino masses. With minimal modification, it is shown to accommodate as well the cases of normal hierarchy and inverted hierarchy. In all cases, this new model predicts sin^2 2 theta_{atm} = 1 and tan^2 theta_{sol} = 0.5 for U_{e3} = 0. It also predicts their deviations from 1 and 0.5 respectively for U_{e3} not equal to zero.
description: 12 pages, no figure
Systematic model reduction captures the dynamics of extrinsic noise in biochemical subnetworks
Creators: name: Bravi, Barbara
name: Rubin, Katy J.
name: Sollich, Peter
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Molecular Networks (q-bio.MN)
subject: FOS: Biological sciences

description: We consider the general problem of describing the dynamics of subnetworks of larger biochemical reaction networks, e.g. protein interaction networks involving complex formation and dissociation reactions. We propose the use of model reduction strategies to understand the 'extrinsic' sources of stochasticity arising from the rest of the network. Our approaches are based on subnetwork dynamical equations derived by projection methods and by path integrals. The results provide a principled derivation of the different components of the extrinsic noise that is observed experimentally in cellular biochemical reactions, over and above the intrinsic noise from the stochasticity of biochemical events in the subnetwork. We explore several intermediate approximations to assess systematically the relative importance of different extrinsic noise components, including initial transients, long-time plateaus, temporal correlations, multiplicative noise terms and nonlinear noise propagation. The best approximations achieve excellent accuracy in quantitative tests on a simple protein network and on the epidermal growth factor receptor signalling network.
description: 24 pages, 10 figures
Artificial chemistry experiments with chemlambda, lambda calculus, interaction combinators
Creators: name: Buliga, Marius
Publisher: name: figshare
Year: 2020
Subjects: subject: 80102 Artificial Life
subject: FOS: Computer and information sciences
subject: Computation Theory and Mathematics
subject: 80203 Computational Logic and Formal Languages
subject: Computer Software
subject: Distributed Computing
subject: 80204 Mathematical Software
subject: 80306 Open Software

description: These are introductory notes to the pages of artificial chemistry experiments with chemlambda, lambda calculus or interaction combinators, available from the entry page chemlambda.github.io at this https URL .

The experiments are bundled into pages, all of them based on a library of programs, on a database which contains hundreds of graphs and on a database of about 150 pages of text comments and a collection of more than 200 animations, most of them which can be re-done live, via the programs. There are links to public repositories of other contributors to these experiments, with versions of these programs in python, haskell, awk or javascript.
A COMPARISON OF THE PERCEPTIONS OF FARM WORKERS ON PERSONNEL MANAGEMENT EFFICIENCY IN NINE FARM BUSINESS TYPES IN THE RSA
'n Vergelyking van plaaswerkers se persepsies oor personeelbestuurs-doeltreffendheid in nege boerderyondernenungtipes in die RSA
Creators: name: Oosthuizen, L. K.
name: Oosthuizen, L. K.
Publisher: name: Unknown
Year: 1994
Subjects: Farm Management
Labor and Human Capital

description: The aim is, firstly, to establish the degree of discrepancy in the work experience and work preferences of the farm workers as regards leadership, motivation, communication, human relations, control and work performance in nine types of farm businesses over a wide area in the RSA. Second, the applicability and feasibility of the personnel management audit (PMA) in various types of businesses were evaluated. Nine PMAs were conducted with 239 farm workers in the Transvaal, Natal and the Orange Free State over the past five years. In general the workers are subject to consultative personnel management systems, but they prefer participative systems, which means that greater personnel management efficiency can be obtained in practice if the staff can attain more participation as regards leadership, motivation, communication, human relations, staff control and work performance. With the required adjustments, the PMA can be implemented in any farm business and applicable results can be obtained.
FARMER CHARACTERISTICS, RISK SOURCES AND MANAGERIAL RESPONSES TO RISK IN VEGETABLE FARMING: EVIDENCE FROM LARGE- AND SMALL-SCALE COMMERCIAL VEGETABLE FARMERS IN KWAZULU-NATAL
Eiensklippe van boere, risikobronne en bestuursoptrede ten opligte van risiko van groenteboerdery met spesifieke verwysmg na greet- en kleinskaalse kommersiele groenteboere m KwaZulu-Natal
Creators: name: Bullock, W. I.
name: Ortmann, G. F.
name: Levin, J. B.
name: Bullock, W. I.
name: Ortmann, G. F.
name: Levin, J. B.
Publisher: name: Unknown
Year: 1994
Subjects: Crop Production/Industries
Farm Management
Risk and Uncertainty

description: Vegetable farmers in KwaZulu-Natal were surveyed on their sources and managerial responses to risk. Most respondents considered themselves more willing to take nsks relative to other farmers. Respondents viewed price, climate and yield variability as the most important sources of risk in vegetable production. Results show that government policies add to the level of uncertainty faced-by vegetable farmers. However, large and small vegetable farmers differed in their perceptions of risk. Small farmers perceived changes in credit availability and changes in Input costs to be more important risk sources than large farmers, while the latter were more concerned with changing interest rates. Irrigation, timely access to machinery, being a low cost producer, and diversification were considered by both .large and small farmers as the most significant managerial responses to risk. Factor analysis of risk sources and managerial responses to risk suggest there are more dimensions to risk than are commonly included in economic analyses.
Establishing Diversity, Equity, and Inclusion Priorities for Occupational Therapy Research
Creators: name: Washington, Selena E.
name: Banks, Tyra M.
name: Román-Oyola, Rosa
name: Hoyt, Catherine R.
name: Johnson, Khalilah R.
name: Hamed, Razan
Publisher: name: AOTA Press
Year: 2024

description:
In this State of the Science column, we examine evidence that aligns common applications of diversity, equity, and inclusion (DEI) and occupational therapy research and suggest areas of focus to advance a culturally affirming and antiracist science of occupation. More specifically, we describe why DEI is important to the study of occupation, identify DEI gaps in the occupational therapy knowledge base, suggest DEI priorities for occupational therapy research and their implications for practice, and recommend practical strategies for occupational therapy scholars to apply in more immediate efforts to address DEI in their research endeavors.