cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Do-calculus enables estimation of causal effects in partially observed biomolecular pathways
Creators: name: Mohammad-Taheri, Sara
name: Zucker, Jeremy
name: Hoyt, Charles Tapley
name: Sachs, Karen
name: Tewari, Vartika
name: Ness, Robert
name: Vitek, and Olga
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Estimating causal queries, such as changes in protein abundance in response to a perturbation, is a fundamental task in the analysis of biomolecular pathways. The estimation requires experimental measurements on the pathway components. However, in practice many pathway components are left unobserved (latent) because they are either unknown, or difficult to measure. Latent variable models (LVMs) are well-suited for such estimation. Unfortunately, LVM-based estimation of causal queries can be inaccurate when parameters of the latent variables are not uniquely identified, or when the number of latent variables is misspecified. This has limited the use of LVMs for causal inference in biomolecular pathways. In this manuscript, we propose a general and practical approach for LVM-based estimation of causal queries. We prove that, despite the challenges above, LVM-based estimators of causal queries are accurate if the queries are identifiable according to Pearl's do-calculus, and describe an algorithm for its estimation. We illustrate the breadth and the practical utility of this approach for estimating causal queries in four synthetic and two experimental case studies, where structures of biomolecular pathways challenge the existing methods for causal query estimation. The code and the data documenting all the case studies are available at \url{https://github.com/srtaheri/LVMwithDoCalculus}
description: https://academic.oup.com/bioinformatics/article/38/Supplement_1/i350/6617530
Interface learning in fluid dynamics: statistical inference of closures within micro-macro coupling models
Creators: name: Pawar, Suraj
name: Ahmed, Shady E.
name: San, Omer
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Many complex multiphysics systems in fluid dynamics involve using solvers with varied levels of approximations in different regions of the computational domain to resolve multiple spatiotemporal scales present in the flow. The accuracy of the solution is governed by how the information is exchanged between these solvers at the interface and several methods have been devised for such coupling problems. In this article, we construct a data-driven model by spatially coupling a microscale lattice Boltzmann method (LBM) solver and macroscale finite difference method (FDM) solver for reaction-diffusion systems. The coupling between the micro-macro solvers has one to many mapping at the interface leading to the interface closure problem, and we propose a statistical inference method based on neural networks to learn this closure relation. The performance of the proposed framework in a bifidelity setting partitioned between the FDM and LBM domain shows its promise for complex systems where analytical relations between micro-macro solvers are not available.
Production structure and derived demand for factor inputs in smallholder dairying in Kenya
Creators: name: Kavoi, Mutuku Muendo
name: Hoag, Dana L.
name: Pritchett, James G.
name: Kavoi, Mutuku Muendo
name: Hoag, Dana L.
name: Pritchett, James G.
Publisher: name: Unknown
Year: 2009
Subjects: subject: Livestock Production/Industries
subject: production structure
subject: translog cost function
subject: marginal zones
subject: elasticities
subject: scale economies

description: This study examined the production structure of smallholder dairy farms in Kenya’s marginal zones, using duality theory in production and costs. The restricted translog cost function was used to derive a system of six input share equations, which were estimated simultaneously with the cost equation by the iterative Zellner procedure. The Morishima elasticities of inputs and the price elasticities of factor demands were computed, and economies of scale were determined. The results indicated that the production structure is a fairly well integrated system of activities, despite scale diseconomies. The Morishima elasticities indicated that factor inputs are substitutable. For example, as prices of formal feeds remain relatively high, informal feeds may be substituted for expensive formal feeds. Policy makers can use these findings to suggest ways of rationalizing feed quality and markets. This would enhance extension and research on balancing protein needs with the current use of roughage on the farms.
Een kort Bispe Krønike over Stavanger og Christiansands, Aggershuus, Bergen og Tronhjems Stifter fra Reformationen indtil vore Tider 1741 : endvidere Series episcoporum under Katholicismen i Hammars, Opsloes og Stavangers Bispedømmer
Creators: name: (:Unas)
Publisher: name: Unknown
Year: 0

description: (Kun lesesalsbruk) (Kopi)
On invariants of a set of elements of a semisimple Lie algebra
Creators: name: Losev, Ivan V.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Representation Theory (math.RT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 17B20, 14R20 (Primary), 14L30 (Secondary)

description: Let $G$ be a complex reductive algebraic group, $g$ its Lie algebra and $h$ a reductive subalgebra of $g$, $n$ a positive integer. Consider the diagonal actions $G:g^n, N_G(h):h^n$. We study a relation between the algebra $C[h^n]^{N_G(h)}$ and its subalgebra consisting of restrictions to $h^n$ of elements of $C[g^n]^G$.
description: 11 pages
A Black-Hole Feedback Valve in Massive Galaxies
Creators: name: Voit, G. M.
name: Bryan, G. L.
name: Prasad, D.
name: Frisbie, R.
name: Li, Y.
name: Donahue, M.
name: O'Shea, B. W.
name: Sun, M.
name: Werner, N.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Star formation in the universe's most massive galaxies proceeds furiously early in time but then nearly ceases. Plenty of hot gas remains available but does not cool and condense into star-forming clouds. Active galactic nuclei (AGN) release enough energy to inhibit cooling of the hot gas, but energetic arguments alone do not explain why quenching of star formation is most effective in high-mass galaxies. In fact, optical observations show that quenching is more closely related to a galaxy's central stellar velocity dispersion ($σ_v$) than to any other characteristic. Here, we show that high $σ_v$ is critical to quenching because a deep central potential well maximizes the efficacy of AGN feedback. In order to remain quenched, a galaxy must continually sweep out the gas ejected from its aging stars. Supernova heating can accomplish this task as long as the AGN sufficiently reduces the gas pressure of the surrounding circumgalactic medium (CGM). We find that CGM pressure acts as the control knob on a valve that regulates AGN feedback and suggest that feedback power self-adjusts so that it suffices to lift the CGM out of the galaxy's potential well. Supernova heating then drives a galactic outflow that remains homogeneous if $σ_v \gtrsim 240 \, {\rm km \, s^{-1}}$. AGN feedback can effectively quench galaxies with a comparable velocity dispersion, but feedback in galaxies with a much lower velocity dispersion tends to result in convective circulation and accumulation of multiphase gas within the galaxy.
description: 29 pages, 8 figures, published in ApJ
Reconstructing the electron in a fractionalized quantum fluid
Creators: name: Jain, Jainendra K.
name: Peterson, Michael R.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The low energy physics of the fractional Hall liquid is described in terms quasiparticles that are qualitatively distinct from electrons. We show, however, that a long-lived electron-like quasiparticle also exists in the excitation spectrum: the state obtained by the application of an electron creation operator to a fractional quantum Hall ground state has a non-zero overlap with a complex, high energy bound state containing an odd number of composite-fermion quasiparticles. The electron annihilation operator similarly couples to a bound complex of composite-fermion holes. We predict that these bound states can be observed through a conductance resonance in experiments involving a tunneling of an external electron into the fractional quantum Hall liquid. A comment is made on the origin of the breakdown of the Fermi liquid paradigm in the fractional hall liquid.
description: 5 pages, 2 figures
Monovalent counterion distributions at highly charged water interfaces: Proton-transfer and Poisson-Boltzmann theory
Creators: name: Bu, Wei
name: Vaknin, David
name: Travesset, Alex
Publisher: name: arXiv
Year: 2005
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Surface sensitive synchrotron-X-ray scattering studies reveal the distributions of monovalent ions next to highly charged interfaces. A lipid phosphate (dihexadecyl hydrogen-phosphate) was spread as a monolayer at the air-water interface, containing CsI at various concentrations. Using anomalous reflectivity off and at the $L_3$ Cs$^+$ resonance, we provide, for the first time, spatial counterion distributions (Cs$^+$) next to the negatively charged interface over a wide range of ionic concentrations. We argue that at low salt concentrations and for pure water the enhanced concentration of hydroniums H$_3$O$^+$ at the interface leads to proton-transfer back to the phosphate group by a high contact-potential, whereas high salt concentrations lower the contact-potential resulting in proton-release and increased surface charge-density. The experimental ionic distributions are in excellent agreement with a renormalized-surface-charge Poisson-Boltzmann theory without fitting parameters or additional assumptions.
TAʻLIM TIZIMIGA INNOVATSOIN YONDOSHUVLARNI JORIY QILISHDA RAHBARGA QOʻYILGAN TALABLAR
Creators: name: Temirov, A.A.
Publisher: name: Zenodo
Year: 2025

description: Mazkur maqolada maktabgacha taʼlim tashkiloti rahbarining maktabgacha ta’lim tashkilotini innovatsion yondashuvlarni qo’llagan holda boshqarishda rahbarga qo’yiladigan talablar, fazilatlar va vazifalar hamda boshqaruvning oʻziga xos xususiyatlari  yoritilgan.
Fresh Meat and Traceability Labelling: Who Cares?
Creators: name: Stranieri, Stefanella
name: Banterle, Alessandro
name: Stranieri, Stefanella
name: Banterle, Alessandro
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agribusiness
subject: Agricultural and Food Policy
subject: Farm Management
subject: Food Consumption/Nutrition/Food Safety
subject: Food Security and Poverty
subject: Industrial Organization
subject: traceability
subject: meat
subject: consumer preferences
subject: logit analysis

description: Within the framework of European food safety measures, Reg. 1760/2000 and 1825/2000 have introduced mandatory traceability and relevant labelling into the beef sector. The paper analyses whether information on meat labels can be considered a useful instrument for consumers, facilitating the verification of quality. The purpose of the paper is, first, to evaluate whether meat information is used during food purchase, and secondly, by focussing on specific meat information, to assess consumer interest in some mandatory and voluntary information cues and to identify the determinants affecting the use of such cues. Data were collected by a telephone questionnaire in a survey conducted in the Lombardy region of northern Italy. The sample consisted of 1,025 consumers. We estimated 4 models based on the literature, and for all the equations we used a binary logit model. The analysis revealed that most consumers tend to use the meat label and also most of the mandatory and voluntary information reported. With regard to mandatory meat labelling, the most important information was considered to be the country of animal origin, in accordance with other empirical studies. With regard to voluntary information, some, like the system of cattle breeding and cattle feeding, seems to be of interest to the Italian consumer. The empirical analysis suggests two different consumer types. The consumers who declare they use meat labels tend to be young people, of female gender, with a low income, and who use the media as their principal source of information. These consumers could have a lot of time available for food purchasing and probably the possibility of reading most of the information reported on the food label, even if they do not have the capacity to process all the information. On the other hand, those consumers who read specific labelled information tend to have a good level of food knowledge or education and weight problems. This second type of consumer probably does not have much time for food purchasing and they select only that information in which they are mostly interested. Moreover, the analysis reveals that consumers tend to read only information that is quickly understood, and that can help them to evaluate the quality of meat products.
Effect of isotope disorder on the Raman spectra of cubic boron arsenide
Creators: name: Rai, Akash
name: Li, Sheng
name: Wu, Hanlin
name: Lv, Bing
name: Cahill, David G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Boron arsenide (c-BAs) is at the forefront of research on ultrahigh thermal conductivity materials. We present a Raman scattering study of isotopically tailored cubic boron arsenide single crystals for 11 isotopic compositions spanning the range from nearly pure c-$^{10}$BAs to nearly pure c-$^{11}$BAs. Our results provide insights on the effects of strong mass disorder on optical phonons and the appearance of two-mode behavior in the Raman spectra of mixed crystals. Strong isotope disorder also relaxes the one-phonon Raman selection rules, resulting in disorder-activated Raman scattering by acoustic phonons.
description: 16 pages, 6 figures, "submitted to Physical Review Materials"
Milk Farmers' Risk Attitudes: Influence of the Dairy Processing Company
Creators: name: Belhenniche, Geoffroy
name: Duvaleix-Treguer, Sabine
name: Cordier, Jean
name: Belhenniche, Geoffroy
name: Duvaleix-Treguer, Sabine
name: Cordier, Jean
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agribusiness
subject: Agricultural and Food Policy
subject: Farm Management
subject: Food Consumption/Nutrition/Food Safety
subject: Food Security and Poverty
subject: Risk and Uncertainty
subject: Market Risk
subject: Farmers' risk perceptions
subject: Expected utility framework
subject: Risk preference elicitation
subject: Dairy Sector

description: European market deregulation is destabilizing the economic environment of French farmers leading to an increase in market risks. In the dairy sector, the 2003 CAP reform has lead to major changes (removal of export subsidies and increase in the European milk quota). The dairy supply chain is now coping with higher production and price risks. The dairy supply chain is thinking of new management tools in order to both maintain stability in dairy farm income and secure supply to industrial facilities. One solution may be to strengthen marketing contracts. In this perspective, the knowledge of dairy farmers' risk attitudes is necessary. The goal of this paper is to provide empirical insight into: dairy farmers‘ perceptions of risk and risk management, and the influence of the relationship between farmers and their dairy processing firm on these risk perceptions. Data originate from a sample of eighty livestock farmers in Normandy, one of the three biggest French milk production areas. The survey was carried out during a face-to-face interview in summer 2008. The questionnaire survey focuses on risk perception and strategies used to manage the risk, by asking the farmers to score risks sources and strategies on Likert-scales as in Bard and Barry (2000), and Meuwissen et al. (2001) and on the elicitation of dairy farmers‘ risk preferences using Pennings and Garcia‘s methodology (2001). As in previous studies (Gunjal and Legault, 1995; Meuwissen et al., 2001; Flaten et al., 2005; Fausti and Gillespie, 2006) we show existence of a diversified spectrum of risk preferences and rank risk sources. Institutional risk and price volatility of inputs and outputs are perceived as the main threat on farm income. However, our main contribution is to examine the influence of dairy processors on farmers‘ preferences and the study attempt to establish a link between the type of contractors (eg. private vs. cooperative) and farm managers‘ risk aversion.
ROSAT observations of the soft X-ray background and of the cluster soft excess emission in the Hercules supercluster
Creators: name: Bonamente, Max
name: Lieu, Richard
name: Kaastra, Jelle
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent observations with the XMM-Newton satellite confirmed the existence of the soft excess phenomenon in galaxy clusters, earlier discovered in several EUVE, ROSAT and BeppoSAX observations. Among the clusters for which XMM has reported detection of soft excess emission are MKW03s and A2052, two clusters in the Hercules concentration. The Hercules supercluster lies along the southern extension of the North Polar Spur, a region of bright soft X-ray emission clearly visible in ROSAT All-Sky Survey images. We analyze 11 pointed ROSAT PSPC observations toward 3 clusters in the Hercule concentration, MKW03s, A2052 and A2063, and 8 neighboring fields in order to investigate the soft X-ray emission in that region of the sky. We find that the soft X-ray emission varies by a factor of few on scales of few degrees, rendering the background subtraction a complex task. If the Noth Polar Spur emission is of local origin, we find that only A2052 and A2063 have evidence of cluster soft excess emission, and that the OVII emission lines detected in XMM observations of A2052 and MKW03s are not associated with the cluster. If part or all of the North Polar Spur soft X-ray enhancement is of extragalactic nature, the three clusters feature strong soft excess emission, and the OVII emission lines observed by XMM are genuinely associated with the clusters. We interpret the soft excess emission with the presence of warm gas, either intermixed with the hot intra-cluster medium or in filamentary structures located around the clusters, and estimate that the warm gas is approximately as massive as the hot intra-cluster medium.
description: 17 pages, published in A. & A
A Ferromagnetic Lieb-Mattis Theorem
Creators: name: Nachtergaele, Bruno
name: Starr, Shannon
Publisher: name: arXiv
Year: 2004
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences
subject: 82B10; 82D40

description: We prove ferromagnetic ordering of energy levels for XXX Heisenberg chains of any spin and XXZ spin chains with all spins equal to 1/2. Ferromagnetic ordering means that the minimum energies in the invariant subspaces of fixed total spin are monotone decreasing as a function of the total spin. This result provides a ferromagnetic analogue of the well-known theorem by Lieb and Mattis about ordering of energy levels in antiferromagnetic and ferrimagnetic systems on bipartite graphs.
description: 4 pages, final version, some references added
Supplementary Figures and Tables from Contrasting evolutionary responses in two codistributed species of Galaxias (Pisces, Galaxiidae) in a river from the glaciated range in Southern Chile
Creators: name: P. F. Victoriano
name: C. P. Muñoz-Ramírez
name: C. B. Canales-Aguirre
name: A. Jara
name: I. Vera-Escalona
name: T. Burgos-Careaga
name: C. Muñoz-Mendoza
name: E. M. Habit
Publisher: name: The Royal Society
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Ecology

description: Life-history traits are among the most important factors affecting population abundance and genetic diversity of species. Here, we analysed the genetic patterns of two Galaxias species with different life-history traits to investigate how these biological differences impacted their evolution in the Valdivia River basin, Southern Chile. We analysed mitochondrial DNA (mtDNA) sequences from 225 individuals of Galaxias maculatus and 136 of G. platei to compare patterns of genetic diversity, structure and demographic growth across the basin. Galaxias maculatus presented higher genetic diversity and higher genetic structure than G. platei. Demographic analyses showed G. maculatus kept a higher population size over time, with a signal of demographic expansion in the last 250 kya. Whereas Galaxias platei, exhibited lower, but constant population size over time. Furthermore, haplotype networks revealed higher lineage diversity in G. maculatus with a tendency to occupy different areas of the basin. Coalescent simulations ruled out that genetic differences between species could be explained by stochastic processes (genetic drift), suggesting species-specific biological differences as responsible for the observed genetic differences. We discuss how differences in life-history traits and past glaciations interact to shape the evolutionary history of the two Galaxias species.
Spin effects in large rapidity neutral pion production at STAR
Creators: name: Ogawa, Akio
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: First measurements of large Feynman x (x_F) neutral pion production in polarized proton collisions at sqrt(s)=200 GeV were reported previously. Cross section measurements at =3.3 and 3.8$ and analyzing power (A_N) measurements at =3.8 were completed for 0.3 < x_F < 0.6. The cross section was found to be consistent with next-to-leading order perturbative QCD calculations. In that framework, the dominant subprocess is partonic collisions of valence quarks on low Bjorken-x gluons. The A_N was found to be large and positive and increasing with x_F, and consistent with phenomonological calculations based on the Collins effect, the Sivers effect and initial-state and final-state higher twist contributions. Subsequent data have been acquired with transverse polarized proton collisions at RHIC at sqrt(s)=200 GeV. The status of the analysis and preliminary results will be presented.
description: 4 pages, 2 figures, Submitted talk presented at the "16th International spin physics symposium" (SPIN2004) 10-16 Oct 2004, Trieste, Italy. To be published in proceedings
Excess of high-$z$ galaxies as a test for bumpy power spectrum of density perturbations
Creators: name: Tkachev, M. V.
name: Pilipenko, S. V.
name: Mikheeva, E. V.
name: Lukash, V. N.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Modified matter power spectra with approximately Gaussian bump on sub-Mpc scales can be a result of a complex inflation. We consider five spectra with different Gaussian amplitudes $A$ and locations $k_0$ and run N-body simulations in a cube $(5 Mpc/h)^3$ at $z>8$ to reveal the halo mass functions and their evolution with redshift. We have found that the Sheth-Tormen formula provides a good approximation to a such kind of halo mass functions. In the considered models the dark matter halo formation starts much more earlier than in $Λ$CDM, which in turn can result in an earlier star formation and a nuclear activity in galaxies and can be detected and tested by, e.g., JWST. At $z=0$ the halo mass functions are hardly distinguishable from the standard $Λ$CDM, therefore the models with the bumpy spectra can be identified in observations by their excess in number of bright sources at high redshift only.
description: 9 pages, 5 figures, submitted to MNRAS
An exact solution method for the enumeration of connected Feynman diagrams
Creators: name: Castro, Erick Ramon
name: Roditi, Itzhak
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We completely generalize previous results related to the counting of connected Feynman diagrams. We use a generating function approach, which encodes the Wick contraction combinatorics of the respective connected diagrams. Exact solutions are found for an arbitrary number of external legs, and a general algorithm is implemented for this calculus. From these solutions, we calculate many asymptotics expansion terms for a simple analytical tool (Taylor expansion theorem). Our approach offers new perspectives in the realm of Feynman diagrams enumeration (or zero-dimensional quantum field theory).
description: 17 pages, 1 figure
Co-moving frame radiative transfer in spherical media with arbitrary velocity fields
Creators: name: Baron, E.
name: Hauschildt, Peter H.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recently, with the advances in computational speed and availability there has been a growth in the number and resolution of fully 3-D hydrodynamical simulations. However, all of these simulations are purely hydrodynamical and there has been little attempt to include the effects of radiative transfer except in a purely phenomenological manner because the computational cost is too large even for modern supercomputers. While there has been an effort to develop 3-D Monte Carlo radiative transfer codes, most of these have been for static atmospheres or have employed the Sobolev approximation, which limits their applicability to studying purely geometric effects such as macroscopic mixing. Also the computational requirements of Monte Carlo methods are such that it is difficult to couple with 3-D hydrodynamics. Here, we present an algorithm for calculating 1-D spherical radiative transfer in the presence of non-monotonic velocity fields in the co-moving frame. Non-monotonic velocity flows will occur in convective, and Raleigh--Taylor unstable flows, in flows with multiple shocks, and in pulsationally unstable stars such as Mira and Cepheids. This is a first step to developing fully 3-D radiative transfer than can be coupled with hydrodynamics. We present the computational method and the results of some test calculations.
description: 17 pages, 9 figures, A&A, in press
Retomando o estruturalismo
Creators: name: Silva, Jose Maria Alves Da
name: Silva, Jose Maria Alves Da
Publisher: name: Unknown
Year: 2010
Subjects: subject: Political Economy
subject: Public Economics
subject: Strucuturalism
subject: macroeconomic theory
subject: “two sector” model
subject: Brazil

description: Economic crisis has been activated keynesianism. The current trends of the brazilian economy make it advisable to reseat the structuralism in economic debate. This is the primary goal of this article. To do this, it discusses a “two sector” macroeconomic model whereby sought to show its relevance as a guide of thought for a series of relevant socio-economic issues, especially for third world countries. We have tried to show its consistency with certain empirical evidence and how it can be used in objective critics against economic strategies that have been proposed for Brazil.
Galactic dynamo and helicity losses through fountain flow
Creators: name: Shukurov, Anvar
name: Sokoloff, Dmitry
name: Subramanian, Kandaswamy
name: Brandenburg, Axel
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Nonlinear behaviour of galactic dynamos is studied, allowing for magnetic helicity removal by the galactic fountain flow. A suitable advection speed is estimated, and a one-dimensional mean-field dynamo model with dynamic alpha-effect is explored. It is shown that the galactic fountain flow is efficient in removing magnetic helicity from galactic discs. This alleviates the constraint on the galactic mean-field dynamo resulting from magnetic helicity conservation and thereby allows the mean magnetic field to saturate at a strength comparable to equipartition with the turbulent kinetic energy.
description: 4 pages, 2 figures, accepted by A&A Letters
Supplementary material from The evolution of paternal care: a role for microbes?
Creators: name: Gurevich, Yael
name: Lewin-Epstein, Ohad
name: Hadany, Lilach
Publisher: name: The Royal Society
Year: 2020
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 60102 Bioinformatics
subject: FOS: Computer and information sciences
subject: 60801 Animal Behaviour
subject: 10202 Biological Mathematics
subject: FOS: Mathematics

description: Paternal care, particularly in cases of uncertain paternity, carries significant costs. Extensive research, both theoretical and experimental, has explored the conditions in which paternal care behaviour would be favoured. Common explanations include an adjustment of care with uncertainty in paternity and limited accuracy in parentage assessment. Here, we propose a new explanation that microbes may play a role in the evolution of paternal care among their hosts. Using computational models, we demonstrate that microbes associated with increased paternal care could be favoured by natural selection. We find that microbe-induced paternal care could evolve under wider conditions than suggested by genetic models. Moreover, we show that microbe-induced paternal care is more likely to evolve when considering paternal care interactions that increase microbial transmission, such as feeding and grooming. Our results imply that factors affecting the composition of host microbiome may also alter paternal behaviour.This article is part of the theme issue ‘The role of the microbiome in host evolution’.
Frame Within a Frame: Using Architecture to Amplify Focus
Creators: name: Oliveira D., M. Jorge
Publisher: name: EmpowerVerse Media, Information & Communication Agency
Year: 2025
Subjects: photography
composition
frame within a frame

description: In photography, composition can transform a simple snapshot into a compelling narrative, and one of the most powerful techniques is the use of a "frame within a frame". By incorporating architectural elements into our composition, we can guide the viewer’s eye, create layers of meaning, and amplify focus on our subject. This article explores the interplay between architecture and photography, examining how visual cues from buildings, windows, archways, and other structures enhance depth and storytelling.
High-statistics pedestrian dynamics on stairways and their probabilistic fundamental diagrams
Creators: name: Pouw, Caspar A. S.
name: Corbetta, Alessandro
name: Gabbana, Alessandro
name: van der Laan, Chiel
name: Toschi, Federico
Publisher: name: arXiv
Year: 2023
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Staircases play an essential role in crowd dynamics, allowing pedestrians to flow across large multi-level public facilities such as transportation hubs, and office buildings. Achieving a robust understanding of pedestrian behavior in these facilities is a key societal necessity. What makes this an outstanding scientific challenge is the extreme randomness intrinsic to pedestrian behavior. Any quantitative understanding necessarily needs to be probabilistic, including average dynamics and fluctuations. In this work, we analyze data from an unprecedentedly high statistics year-long pedestrian tracking campaign, in which we anonymously collected millions of trajectories across a staircase within Eindhoven train station (NL). Made possible thanks to a state-of-the-art, faster than real-time, computer vision approach hinged on 3D depth imaging, and YOLOv7-based depth localization. We consider both free-stream conditions, i.e. pedestrians walking in undisturbed, and trafficked conditions, uni/bidirectional flows. We report the position vs density, considering the crowd as a 'compressible' physical medium. We show how pedestrians willingly opt to occupy fewer space than available, accepting a certain degree of compressibility. This is a non-trivial physical feature of pedestrian dynamics and we introduce a novel way to quantify this effect. As density increases, pedestrians strive to keep a minimum distance d = 0.6 m from the person in front of them. Finally, we establish first-of-kind fully resolved probabilistic fundamental diagrams, where we model the pedestrian walking velocity as a mixture of a slow and fast-paced component. Notably, averages and modes of velocity distribution turn out to be substantially different. Our results, including probabilistic parametrizations based on few variables, are key towards improved facility design and realistic simulation of pedestrians on staircases.
System Approach for Evaluating Locally Grown Produce Issues
Creators: name: Berruto, Remigio
name: Busato, Patrizia
name: Berruto, Remigio
name: Busato, Patrizia
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agribusiness
subject: Agricultural and Food Policy
subject: Farm Management
subject: Food Consumption/Nutrition/Food Safety
subject: System approach
subject: locally grown
subject: supply–chain
subject: fruits and vegetables
subject: logistics
subject: simulation

description: The potential advantages of locally grown produce are mainly related to the coexistence of production and consumption in the same area. These advantages are: reduced transportation, freshness, better taste, easy traceability, transparency, food safety, environmental sustainability and community development. Despite these positive aspects, the money spent for locally grown produce represents only a small percentage of the total money spent for fresh produce purchases. On the other hand, interest is growing for furnishing produce to local produce schools, hospitals and public institutions. The supply chains of locally grown produce are classified into direct marketing distributions (farmers’ markets, CSAs, roadside stands, on-farm stores) and indirect marketing distributions (restaurants, foodservices, supermarkets). Each supply chain is characterized by different factors, including the expectations of customers which, coincidentally, drive logistics and postharvest handling activities. The supply chains and the logistics of locally grown produce are described, with the analysis of potential benefits and barriers to expansion, using the system approach technique.
The effect of curvature on the eigenexcitations of magnetic skyrmions
Creators: name: Korniienko, Anastasiia
name: Kákay, Attila
name: Sheka, Denis D.
name: Kravchuk, Volodymyr P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Spectrum of spin eigenmodes localized on a ferromagnetic skyrmion pinned by a geometrical defect (bump) of magnetic films is studied theoretically. By means of direct numerical solution of the corresponding eigenvalue problem and finite element micromagnetic simulations we demonstrate, that the curvature can induce localized modes with higher azimuthal and radial quantum numbers, which are absent for planar skyrmions (for the same parameters). The eigenfrequencies of all modes, except the breathing and gyromodes decreases with increasing curvature. Due to the translational symmetry break, the zero translational mode of the skyrmion gains a finite frequency and forms the gyromode, which describes the uniform rotation of skyrmions around the equilibrium position. In order to treat the gyromotion analytically we developed a Thiele-like collective variable approach. We show that Néel skyrmions in curvilinear films experience a driving force originating from the gradient of the mean curvature. The gyrofrequency of the pinned skyrmion is proportional to the second derivative of the mean curvature at the point of equilibrium.
description: 11 pages, 4 figures
Squamish revealed
Creators: name: Sadler, Heather B. W.
Publisher: name: University of British Columbia
Year: 2009

description: The vast majority of current urban design is occurring on a massive scale without respect given to the social, cultural or physical surroundings. The resulting spaces are neither unique, nor differentiated; they are non-descript and homogenous. While the downtown of Squamish, British Columbia has maintained its unique spirit and appeal, a result of the spectacular natural setting, the social character and the industrial heritage, it is struggling to exist in behind the veneer of the Sea to Sky Highway. As Squamish is facing major new development opportunities, potential exists to re-orient development to revitalize the downtown area. In creating an urban design vision for Squamish, the social, cultural and natural characteristics were considered. Three principles that embody these characteristics - enliven the downtown, maximize on the natural surroundings, and maintain the industrial character - were adhered to. The resulting design vision proposes interventions ranging from population densification, an alternate entrance into the downtown, an open space framework, and street re-configuration. Each of these interventions contributes to the overall goal of creating a unique, differentiated and vibrant downtown core.
The possibility of the secondary object in GW190814 as a neutron star
Creators: name: Huang, Kaixuan
name: Hu, Jinniu
name: Zhang, Ying
name: Shen, Hong
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A compact object was observed with a mass $2.50-2.67~M_\odot$ by LIGO Scientific and Virgo collaborations (LVC) in GW190814, which provides a great challenge to the investigations into the supranuclear matter. To study this object, properties of neutron star are systematically calculated within the latest density-dependent relativistic mean-field (DDRMF) parameterizations, which are determined by the ground state properties of spherical nuclei. The maximum masses of neutron star calculated by DD-MEX and DD-LZ1 sets can be around $2.55~M_\odot$ with quite stiff equations of state generated by their strong repulsive contributions from vector potentials at high densities. Their maximum speeds of sound $c_s/c$ are smaller than $\sqrt{0.8}$ at the center of neutron star and the dimensionless tidal deformabilities at $1.4~M_\odot$ are less than $800$. Furthermore, the radii of $1.4 ~M_\odot$ also satisfy the constraint from the observation of mass-radius simultaneous measurements (NICER). Therefore, we conclude that one cannot exclude the possibility of the secondary object in GW190814 as a neutron star composed of hadron matter from DDRMF models.
description: 13 pages, 8 figures, 3 tables
Suplemental Methods, Suplemental Results, Supplementary Figures from Evolution of drug-resistant and virulent small colonies in phenotypically diverse populations of the human fungal pathogen Candida glabrata
Creators: name: Duxbury, Sarah J. N.
name: Bates, Steven
name: Beardmore, Robert E.
name: Gudelj, Ivana
Publisher: name: The Royal Society
Year: 2020
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Ecology

description: Antimicrobial resistance frequently carries a fitness cost to a pathogen, measured as a reduction in growth rate compared to the sensitive wild type, in the absence of antibiotics. Existing empirical evidence points to the following relationship between cost of resistance and virulence. If a resistant pathogen suffers a fitness cost in terms of reduced growth rate it commonly has lower virulence compared to the sensitive wild type. If this cost is absent so is the reduction in virulence. Here we show, using experimental evolution of drug resistance in the fungal human pathogen Candida glabrata, that reduced growth rate of resistant strains need not result in reduced virulence. Phenotypically heterogeneous populations were evolved in parallel containing highly resistant sub-population small colony variants (SCVs) alongside sensitive sub-populations. Despite their low growth rate in the absence of an antifungal drug, the SCVs did not suffer a marked alteration in virulence compared with the wild-type ancestral strain, or their co-isolated sensitive strains. This contrasts with classical theory that assumes growth rate to positively correlate with virulence. Our work thus highlights the complexity of the relationship between resistance, basic life-history traits and virulence.
Inclusive, prompt and non-prompt $\rm{J}/ψ$ identification in proton-proton collisions at the Large Hadron Collider using machine learning
Creators: name: Prasad, Suraj
name: Mallick, Neelkamal
name: Sahoo, Raghunath
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Studies related to $\rm{J}/ψ$ meson, a bound state of charm and anti-charm quarks ($c\bar{c}$), in heavy-ion collisions, provide genuine testing grounds for the theory of strong interaction, quantum chromodynamics (QCD). To better understand the underlying production mechanism, cold nuclear matter effects, and influence from the quark-gluon plasma, baseline measurements are also performed in proton-proton ($pp$) and proton-nucleus ($p$--A) collisions. The inclusive $\rm{J}/ψ$ measurement has contributions from both prompt and non-prompt productions. The prompt $\rm{J}/ψ$ is produced directly from the hadronic interactions or via feed-down from directly produced higher charmonium states, whereas non-prompt $\rm{J}/ψ$ comes from the decay of beauty hadrons. In experiments, $\rm{J}/ψ$ is reconstructed through its electromagnetic decays to lepton pairs, in either $e^{+}+e^{-}$ or $μ^{+}+μ^{-}$ decay channels. In this work, for the first time, machine learning techniques are implemented to separate the prompt and non-prompt dimuon pairs from the background to obtain a better identification of the $\rm{J}/ψ$ signal for different production modes. The study has been performed in $pp$ collisions at $\sqrt{s} = 7$ and 13 TeV simulated using PYTHIA8. Machine learning models such as XGBoost and LightGBM are explored. The models could achieve up to 99\% prediction accuracy. The transverse momentum ($p_{\rm T}$) and rapidity ($y$) differential measurements of inclusive, prompt, and non-prompt $\rm{J}/ψ$, its multiplicity dependence, and the $p_{\rm T}$ dependence of fraction of non-prompt $\rm{J}/ψ$ ($f_{\rm B}$) are shown. These results are compared to experimental findings wherever possible.
description: Same as the published version in Phys. Rev. D
What Was Written vs. Who Read It: News Media Profiling Using Text Analysis and Social Media Context
Creators: name: Baly, Ramy
name: Karadzhov, Georgi
name: An, Jisun
name: Kwak, Haewoon
name: Dinkov, Yoan
name: Ali, Ahmed
name: Glass, James
name: Nakov, Preslav
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computation and Language (cs.CL)
subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences
subject: I.2.7
subject: 68T50

description: Predicting the political bias and the factuality of reporting of entire news outlets are critical elements of media profiling, which is an understudied but an increasingly important research direction. The present level of proliferation of fake, biased, and propagandistic content online, has made it impossible to fact-check every single suspicious claim, either manually or automatically. Alternatively, we can profile entire news outlets and look for those that are likely to publish fake or biased content. This approach makes it possible to detect likely "fake news" the moment they are published, by simply checking the reliability of their source. From a practical perspective, political bias and factuality of reporting have a linguistic aspect but also a social context. Here, we study the impact of both, namely (i) what was written (i.e., what was published by the target medium, and how it describes itself on Twitter) vs. (ii) who read it (i.e., analyzing the readers of the target medium on Facebook, Twitter, and YouTube). We further study (iii) what was written about the target medium on Wikipedia. The evaluation results show that what was written matters most, and that putting all information sources together yields huge improvements over the current state-of-the-art.
description: Factuality of reporting, fact-checking, political ideology, media bias, disinformation, propaganda, social media, news media
Table S3: Avian visual system diffraction from Symbiotic magnetic sensing: raising evidence and beyond
Creators: name: Eviatar Natan
name: Fitak, Robert Rodgers
name: Werber, Yuval
name: Vortman, Yoni
Publisher: name: The Royal Society
Year: 2020
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Ecology
subject: 60801 Animal Behaviour

description: The identity of a magnetic sensor in animals remains enigmatic. Although the use of the geomagnetic field for orientation and navigation in animals across a broad taxonomic range has been well established over the past five decades, the identity of the magnetic-sensing organ and its structure and/or apparatus within such animals remains elusive—‘a sense without a receptor’. Recently, we proposed that symbiotic magnetotactic bacteria (MTB) may serve as the underlying mechanism behind a magnetic sense in animals—‘the symbiotic magnetic-sensing hypothesis'. Since we first presented this hypothesis, both criticism and support have been raised accordingly. Here we address the primary criticisms and discuss the plausibility of such a symbiosis, supported by preliminary findings demonstrating the ubiquity of MTB DNA in general, and specifically in animal samples. We also refer to new supporting findings, and discuss host adaptations that could be driven by such a symbiosis. Finally, we suggest the future research directions required to confirm or refute the possibility of symbiotic magnetic-sensing.This article is part of the theme issue ‘The role of the microbiome in host evolution’.
Soil management for vegetable growing in the Philippine uplands: A bio-economic analysis
Creators: name: Akhter, Sanzida
name: Menz, Kenneth M.
name: Akhter, Sanzida
name: Menz, Kenneth M.
Publisher: name: Unknown
Year: 2010
Subjects: Agribusiness

description: Abstract Soil nutrient loss due to soil erosion and removal in harvest with traditional farming methods where farmers do not use any fertilisers threatens the sustainability of vegetable productions in the Philippine uplands. Consequently, poor farmers are losing incomes due to declining yields. The situation is reaching crisis point. A bio-economic analysis is used in this research to investigate the economic returns in terms of gross and net annual income over time for upland farmers from adopting alternative soil management options. Cost benefit analysis is used to compare the net returns to farmers from potential management options. A bio-physical model, SCUAF, is used to simulate the long-run tomato yields and associated soil erosion, over a seven-year period, for different soil management options which are both income enhancing and soil nutrient preserving. Data obtained through experiments and surveys of upland farmers in Claveria in the Philippines island of Mindanao, are used to derive yearly production budget for tomato farming on one hectare of land. The analyses reveal that significantly higher economic returns are achievable a combination of organic and inorganic fertiliser additions. This combination seems to be most attractive since it leads to benefits in both yield increase and reduced soil erosion over time. Therefore, concentrating further research on the use of fertiliser combinations, especially at lower rates where marginal returns are highest seems to be an appropriate focus, and one which is most likely to be adopted by farmers.