cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Distributed Trust and Reputation Framework for Mobile Ad Hoc Networks
Creators: name: Sen, Jaydip
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: In a multi-hop mobile ad hoc network (MANET), mobile nodes cooperate to form a network without using any infrastructure such as access points or base stations. The mobility of the nodes and the fundamentally limited capacity of the wireless medium, together with wireless transmission effects such as attenuation, multi-path propagation, and interference combine to create sig-nificant challenges for security in MANETs. Traditional cryptographic mecha-nisms such as authentication and encryption are not capable of handling some kinds of attacks such as packet dropping by malicious nodes in MANETs. This paper presents a mechanism for detecting malicious packet dropping attacks in MANETs. The mechanism is depends on a trust module on each node, which is based on the reputation value computed for that node by its neighbors. The reputation value of a node is computed based on its packet forwarding behavior in the network. The reputation information is gathered, stored and exchanged between the nodes, and computed under different scenario. The proposed pro-tocol has been simulated in a network simulator. The simulation results show the efficiency of its performance.
description: 10 pages, 7 figures, 1 table. Proceedings of the First International Workshop on Trust Management in Peer-to-Peer Systems (IWTMP2PS), pp. 538-547, July, 2010, Chennai, India
A quick and versatile protocol for the 3D visualization of transgene expression across the whole body of larval Drosophila
Creators: name: Kobler, Oliver
name: Weiglein, Aliće
name: Hartung, Kathrin
name: Chen, Yi-chun
name: Gerber, Bertram
name: Thomas, Ulrich
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Biochemistry
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Neuroscience
subject: Pharmacology
subject: Biotechnology
subject: Cancer

description: Larval Drosophila are used as a genetically accessible study case in many areas of biological research. Here we report a fast, robust and user-friendly procedure for the whole-body multi-fluorescence imaging of Drosophila larvae; the protocol has been optimized specifically for larvae by systematically tackling the pitfalls associated with clearing this small but cuticularized organism. Tests on various fluorescent proteins reveal that the recently introduced monomeric infrared fluorescent protein (mIFP) is particularly suitable for our approach. This approach comprises an effective, low-cost clearing protocol with minimal handling time and reduced toxicity in the reagents employed. It combines a success rate high enough to allow for small-scale screening approaches and a resolution sufficient for cellular-level analyses with light sheet and confocal microscopy. Given that publications and database documentations typically specify expression patterns of transgenic driver lines only within a given organ system of interest, the present procedure should be versatile enough to extend such documentation systematically to the whole body. As examples, the expression patterns of transgenic driver lines covering the majority of neurons, or subsets of chemosensory, central brain or motor neurons, are documented in the context of whole larval body volumes (using nsyb-Gal4, IR76b-Gal4, APL-Gal4 and mushroom body Kenyon cells, or OK371-Gal4, respectively). Notably, the presented protocol allows for triple-color fluorescence imaging with near-infrared, red and yellow fluorescent proteins.
The genetic architecture of larval aggregation behavior in Drosophila
Creators: name: McKinney, Ross M.
name: Valdez, Ryan
name: Ben-Shahar, Yehuda
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Neuroscience
subject: Evolutionary Biology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified

description: Many insect species exhibit basal social behaviors such as aggregation, which play important roles in their feeding and mating ecologies. However, the evolutionary, genetic, and physiological mechanisms that regulate insect aggregation remain unknown for most species. Here, we used natural populations of Drosophila melanogaster to identify the genetic architecture that drives larval aggregation feeding behavior. By using quantitative and reverse genetic approaches, we have identified a complex neurogenetic network that plays a role in regulating the decision of larvae to feed in either solitude or as a group. Results from single gene, RNAi-knockdown experiments show that several of the identified genes represent key nodes in the genetic network that determines the level of aggregation while feeding. Furthermore, we show that a single non-coding variant in the gene CG14205, a putative acyltransferase, is associated with both decreased mRNA expression and increased aggregate formation, which suggests that it has a specific role in inhibiting aggregation behavior. Our results identify, for the first time, the genetic components which interact to regulate naturally occurring levels of aggregation in D. melanogaster larvae.
Environmental influences on for-mediated oviposition decisions in Drosophila melanogaster
Creators: name: Vesterberg, Anders
name: Rizkalla, Rudy
name: Fitzpatrick, Mark J.
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Neuroscience
subject: Biotechnology
subject: Evolutionary Biology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: Developmental Biology
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: Deciding whether or not to lay an egg on a given substrate is an important task undertaken by females of many arthropods. It involves perceiving the environment (e.g. quality of the substrate, temperature, and humidity), formulating a decision, and then conducting the appropriate behaviours to oviposit. This oviposition site selection (OSS) provides a useful system for studying simple decision-making. OSS in fruit flies, Drosophila melanogaster, is influenced by both genetic and environmental variation. Naturally occurring allelic variation in the foraging gene (for) is known to affect OSS. Given a choice of high- and low-nutrient oviposition substrates, groups of rovers (forR) are known to lay significantly more of their eggs on low-nutrient sites than sitters (fors) and sitter mutants (fors2). Here we ask three questions: (1) Is the role of for in OSS affected by the availability of alternate oviposition sites? (2) Is the role of for in OSS sensitive to the density of ovipositing females? and (3) Does the gustatory sensation of yeast play a role in for-mediated variation in OSS? We find a role of choice and female density in rover/sitter differences in OSS, as well as a role of for in response to glycerol, an indicator of yeast. The role of for in OSS decision-making is complex and multi-faceted and should prove fertile ground for further research into the factors affecting decision-making behaviours.
Multi-Dimensional Simulations of Pair-Instability Supernovae
Creators: name: Chen, Ke-Jung
name: Heger, Alexander
name: Almgren, Ann
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We present preliminary results from multidimensional numerical studies of pair instability supernova (PSN), studying the fluid instabilities that occur in multiple spatial dimensions. We use the new radiation-hydrodynamics code, CASTRO, and introduce a new mapping procedure that defines the initial conditions for the multidimensional runs in such a way that conservation of physical quantities is guaranteed at any level of resolution.
description: Accepted for publication in Computer Physics Communications. 3 pages. 2 figs
Sex-Specific Neuromuscular and Kinematic Analysis of Unanticipated Single-leg Landings In Young Athletes
Creators: name: Romanchuk, Nicholas
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2019
Subjects: Unanticipated
Drop-Jumps
Kinematics
Electromyography
ACL

description: Despite the higher incidence of anterior cruciate ligament injuries in pediatric female populations, limited research has investigated sex-differences in youth biomechanics. Furthermore, research involving jump mechanics typically requires participant to follow a set protocol, such as sticking the landing. To reduce variability and improve reliability, trails where participants fail to meet the required protocol are discarded; however, significant clinical findings may be elucidated from these trials. The purpose of this thesis was to provide a complete biomechanical analysis of unanticipated single-leg drop-jump landings in youth athletes. Thirty-two healthy youth athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Trials where participants shifted foot position or touched the ground with the contralateral leg were categorized as failed. Drop-jump landings were time-normalized using landmarks within the drop-jump task. Statistical parametric mapping (SPM) determined time-varying sex-differences in muscle onset time, co-activation, kinematics and kinetics. Wilcoxon signed-rank tests and paired sample t-tests compared lower-limb kinematics, centre-of-mass excursion and muscle activation amplitudes during the successful and failed landings. A logistic regression model was also fit to predict the likelihood of a successful landing. SPM identified significantly greater trunk flexion angle in males during the deceleration, flight, and landing phase of the drop-jump. Greater quadriceps-gastrocnemius co-activation was identified during the flight phase in female participants and independent sample t-test identified longer muscle onset time in the vastus lateralis of male participants. When comparing failed and successful landings greater hip abduction and less external rotation angles were observed during the successful trials. In addition, greater preparatory muscle activation was observed in the rectus femoris and semitendinosus during the flight phase of the failed landings. A logistic regression model, which included eight kinematic and neuromuscular variables, offered a training classification accuracy of 70% and a leave-one-out cross-validation accuracy of 65%. In conclusion, females land in a more erect posture and may be less effective at dissipating landing forces. In addition, greater co-activation and shorter pre-activations of the lower limb musculature may indicate a less effective muscle activation strategy in females. Furthermore, hip kinematics and the surrounding musculature play an important role in controlling successful and failed unanticipated landings. The variables included in the logistic regression model indicate which key factors are linked to landing a jump successfully. Training modalities aimed at improving landing mechanics should therefore focus on modifying these variables.
Generation and characterization of fruitless P1 promoter mutant in Drosophila melanogaster
Creators: name: Neville, Megan C.
name: Eastwood, Alexander
name: Allen, Aaron M.
name: de Haan, Ammerins
name: Nojima, Tetsuya
name: Goodwin, Stephen F.
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Physiology
subject: Biotechnology
subject: Evolutionary Biology
subject: Developmental Biology
subject: Cancer
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: 110309 Infectious Diseases
subject: Computational Biology

description: The identification of mutations in the gene fruitless (fru) paved the way for understanding the genetic basis of male sexual behavior in the vinegar fly Drosophila melanogaster. D. melanogaster males perform an elaborate courtship display to the female, ultimately leading to copulation. Mutations in fru have been shown to disrupt most aspects of the male's behavioral display, rendering males behaviorally sterile. The fru genomic locus encodes for multiple transcription factor isoforms from several promoters; only those under the regulation of the most distal P1 promoter are under the control of the sex determination hierarchy and play a role in male-specific behaviors. In this study, we used CRISPR/Cas9-based targeted genome editing of the fru gene, to remove the P1 promoter region. We have shown that removal of the P1 promoter leads to a dramatic decrease in male courtship displays towards females and male-specific sterility. We have expanded the analysis of fru P1-dependent behaviors, examining male's response to courtship song and general activity levels during12-hour light: dark cycles. Our novel allele expands the mutant repertoire available for future studies of fru P1-derived function in D. melanogaster. Our fruΔP1 mutant will be useful for future studies of fru P1-derived function, as it can be homozygosed without disrupting additional downstream promoter function and can be utilized in heterozygous combinations with other extant fru alleles.
Stellar population gradients from cosmological simulations: dependence on mass and environment in local galaxies
Creators: name: Tortora, C.
name: Romeo, A. D.
name: Napolitano, N. R.
name: Antonuccio-Delogu, V.
name: Meza, A.
name: Sommer-Larsen, J.
name: Capaccioli, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The age and metallicity gradients for a sample of group and cluster galaxies from N-body+hydrodynamical simulation are analyzed in terms of galaxy stellar mass. Dwarf galaxies show null age gradient with a tail of high and positive values for systems in groups and cluster outskirts. Massive systems have generally zero age gradients which turn to positive for the most massive ones. Metallicity gradients are distributed around zero in dwarf galaxies and become more negative with mass; massive galaxies have steeper negative metallicity gradients, but the trend flatten with mass. In particular, fossil groups are characterized by a tighter distribution of both age and metallicity gradients. We find a good agreement with both local observations and independent simulations. The results are also discussed in terms of the central age and metallicity, as well as the total colour, specific star formation and velocity dispersion.
description: 9 pages, 5 figures, accepted for publication on MNRAS
Foreseeing Neutrino spectra in Deep Core
Creators: name: Fargion, Daniele
name: D'Armiento, Daniele
name: Di Giacomo, Paola
name: Paggi, Paolo
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Atmospheric muon neutrino in Deep Core (whose rate and spectra might be soon available) should exhibit a suppression (due to tens GeV up-going muon neutrino converted into tau flavor) that must be imprinted in out-coming rate spectra. We estimate here our independent muon neutrino spectra based on SK and its projected record on Deep Core Channels. Our estimate (based on cosmic rays, muon records and tested Super-Kamiokande (SK) data) differs both in shape and in rate from other previous published spectra. The expected rate might exhibit a minimum near channel 6 of Deep Core strings and it should manifest strong signature for flavor mixing (mostly between channel 4--15)and a relevant anomaly for eventual CPT violation (MINOS like) written at channel 3--6,whose statistical weight (mainly at channel 5) might soon confirm or dismiss MINOS CPT claim. At the flux minimum around channel 6, (a flux suppressed respect the non oscillated case at least by an order of magnitude) the atmospheric neutrino paucity offers a better windows to a twenty GeV Neutrino Astronomy. Therefore by doubling the string array we may foresee a richer rate and a more complete (zenith and azimuth) atmospheric neutrino distribution and an exciting first twenty GeV Astronomy.
description: 8 pages, 8 figures
A Trust-Based Detection Algorithm of Selfish Packet Dropping Nodes in a Peer-to-Peer Wireless Mesh Network
Creators: name: Sen, Jaydip
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cryptography and Security (cs.CR)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Wireless mesh networks (WMNs) are evolving as a key technology for next-generation wireless networks showing raid progress and numerous applications. These networks have the potential to provide robust and high-throughput data delivery to wireless users. In a WMN, high speed routers equipped with advanced antennas, communicate with each other in a multi-hop fashion over wireless channels and form a broadband backhaul. However, the throughput of a WMN may be severely degraded due to presence of some selfish routers that avoid forwarding packets for other nodes even as they send their own traffic through the network. This paper presents an algorithm for detection of selfish nodes in a WMN that uses statistical theory of inference for reliable clustering of the nodes based on local observations. Simulation results show that the algorithm has a high detection rate and a low false positive rate.
description: 10 pages, 6 pages, 3 tables. Proceedings of the First Workshop on Trust Management in Peer-to-Peer Systems (IWTMP2PS), pp. 528- 537, July 2010, Chennai, India
Atmospheric optical-turbulence at Roque de los Muchachos Observatory: database and recalibration of the generalized-SCIDAR data
Creators: name: Garcia-Lorenzo, B.
name: Fuensalida, J. J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: We present the largest database so far of atmospheric optical-turbulence profiles (197035 individual CN2(h)) for an astronomical site, the Roque de los Muchachos Observatory (La Palma, Spain). This C2 (h) database was obtained through generalized-SCIDAR observations at the 1 meter Jacobus Kapteyn telescope from Febrary 2004 to August 2009, obtaining useful data for 211 nights. The overestimation of the turbulence strength induced during the generalized SCIDAR data processing has been analyzed for the different observational configurations. All the individual C2 (h) have been recalibrated to compensate the introduced errors during data treatment following (Avila & Cuevas 2009). Comparing results from profiles before and after the recalibration, we analyze its impact on the calculation of relevant parameters for adaptive optics.
description: 8 pages, 3 figures, MNRAS accepted
title: Assessing occupational exposure to radiation in nuclear medicine laboratories in Newfoundland and Labrador's hospitals
Creators: name: Almanea, Fawaz
Publisher: name: Memorial University of Newfoundland
Year: 2020

description: Among the health care workers, nuclear medicine staff are the highest in terms of exposure to ionizing radiation [1][2]. In response to this and as a compliance with the international and national standards, clinical sites have developed detailed procedures to minimize and monitor the occupational exposure. Our study aims to assess the feasibility of using available radiation dose data in the clinical settings in NL for research purposes, and to assess the occupational radiation dose to nuclear medicine staff in Newfoundland and Labrador’s hospitals for the period of 2007 to 2018. Furthermore, our goal is to investigate the general trend of these doses and the effect of technology change on occupational radiation dose. Our study found that the average annual whole body and extremities doses were well below the 50 mSv for whole body dose limit and the 500 mSv for extremities limit which are set by the Canadian Nuclear Safety Commission (CNSC). The average annual whole-body doses in the Health Science’s Centre and St. Clare’s Hospital were below the worldwide average annual dose of 1.9 mSv that was reported by The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)[3]. Overall data showed that 78% of the high value measurements were readings for experienced participants and 22% of the high value readings were for new staff or less experienced participants. Technology changes, such as installing a new imaging machine in HSC shows an impact on the occupational radiation dose trend. Our currently available data is not enough to detect the correlation between the dose variations and (i) the number of procedures, (ii) number of staff, or (iii) type of radiopharmaceuticals. This is establishing the need to enhance the quality of the occupational radiation dose records.
Heavily Obscured AGN in High Redshift Luminous Infrared Galaxies
Creators: name: Treister, Ezequiel
name: Urry, C. Megan
name: Schawinski, Kevin
name: Cardamone, Carolin N.
name: Sanders, David
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We take advantage of the rich multi-wavelength data available in the Chandra Deep Field South (CDF-S), including the 4 Msec Chandra observations (the deepest X-ray data to date), in order to search for heavily-obscured low-luminosity AGN among infrared-luminous galaxies. In particular, we obtained a stacked rest-frame X-ray spectrum for samples of galaxies binned in terms of their IR luminosity or stellar mass. We detect a significant signal at E~1 to 8 keV, which we interpret as originating from a combination of emission associated with star-formation processes at low energies combined with a heavily-obscured AGN at E>5 keV. We further find that the relative strength of this AGN signal decays with decreasing IR luminosity, indicating a higher AGN fraction for more luminous IR sources. Together, these results strongly suggest the presence of a large number of obscured AGN in IR-luminous galaxies. Using samples binned in terms of stellar mass in the host galaxy, we find a significant excess at E=6-7 keV for sources with M>10^{11} Msun, consistent with a large obscured AGN population in high mass galaxies. In contrast, no strong evidence of AGN activity was found for less-massive galaxies. The integrated intensity at high energies indicates that a significant fraction of the total black hole growth, ~22%, occurs in heavily-obscured systems that are not individually detected in even the deepest X-ray observations. There are also indications that the number of low-luminosity, heavily-obscured AGN does not evolve significantly with redshift, in contrast to the strong evolution seen in higher luminosity sources.
description: 5 pages, 3 figures in emulateapj format. Accepted by Astrophysical Journal Letters
New stability results for Einstein scalar gravity
Creators: name: Faulkner, Thomas
name: Horowitz, Gary T.
name: Roberts, Matthew M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider asymptotically anti de Sitter gravity coupled to a scalar field with mass slightly above the Breitenlohner-Freedman bound. This theory admits a large class of consistent boundary conditions characterized by an arbitrary function $W$. An important open question is to determine which $W$ admit stable ground states. It has previously been shown that the total energy is bounded from below if $W$ is bounded from below and the bulk scalar potential $V(ϕ)$ admits a suitable superpotential. We extend this result and show that the energy remains bounded even in some cases where $W$ can become arbitrarily negative. As one application, this leads to the possibility that in gauge/gravity duality, one can add a double trace operator with negative coefficient to the dual field theory and still have a stable vacuum.
Well posedness of an isothermal diffusive model for binary mixtures of incompressible fluids
Creators: name: Berti, A.
name: Berti, V.
name: Grandi, D.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 35Q35, 76T05

description: We consider a model describing the behavior of a mixture of two incompressible fluids with the same density in isothermal conditions. The model consists of three balance equations: continuity equation, Navier-Stokes equation for the mean velocity of the mixture, and diffusion equation (Cahn-Hilliard equation). We assume that the chemical potential depends upon the velocity of the mixture in such a way that an increase of the velocity improves the miscibility of the mixture. We examine the thermodynamic consistence of the model which leads to the introduction of an additional constitutive force in the motion equation. Then, we prove existence and uniqueness of the solution of the resulting differential problem.
Origins of the extragalactic background at 1mm from a combined analysis of the AzTEC and MAMBO data in GOODS-N
Creators: name: Penner, Kyle
name: Pope, Alexandra
name: Chapin, Edward L.
name: Greve, Thomas R.
name: Bertoldi, Frank
name: Brodwin, Mark
name: Chary, Ranga-Ram
name: Conselice, Christopher J.
name: Coppin, Kristen
name: Giavalisco, Mauro
name: Hughes, David H.
name: Ivison, Rob J.
name: Perera, Thushara
name: Scott, Douglas
name: Scott, Kimberly
name: Wilson, Grant
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a study of the cosmic infrared background, which is a measure of the dust obscured activity in all galaxies in the Universe. We venture to isolate the galaxies responsible for the background at 1mm; with spectroscopic and photometric redshifts we constrain the redshift distribution of these galaxies. We create a deep 1.16mm map (sigma ~ 0.5mJy) by combining the AzTEC 1.1mm and MAMBO 1.2mm datasets in GOODS-N. This combined map contains 41 secure detections, 13 of which are new. By averaging the 1.16mm flux densities of individually undetected galaxies with 24um flux densities > 25uJy, we resolve 31--45 per cent of the 1.16mm background. Repeating our analysis on the SCUBA 850um map, we resolve a higher percentage (40--64 per cent) of the 850um background. A majority of the background resolved (attributed to individual galaxies) at both wavelengths comes from galaxies at z > 1.3. If the ratio of the resolved submillimeter to millimeter background is applied to a reasonable scenario for the origins of the unresolved submillimeter background, 60--88 per cent of the total 1.16mm background comes from galaxies at z > 1.3.
description: 12 pages, 10 figures. Accepted by MNRAS. The combined map is publicly available at http://www.astro.umass.edu/~pope/goodsn_mm/
Engagement for all? A study of international undergraduates at the University of British Columbia
Creators: name: Suderman, Michelle Ellen Szabo
Publisher: name: University of British Columbia
Year: 2015

description: American student engagement literature has identified a set of student behaviours and institutional practices shown to lead to student satisfaction, academic success, and retention to graduation among post-secondary students. However, the relevance of these behaviours and the standardized instrument used to measure them may have limited applicability for non-U.S. students. Building on existing quantitative analysis, through focus groups, this study considered how international and Canadian undergraduate students perceived the National Survey of Student Engagement (NSSE) and select behaviours identified in the student engagement literature. This study found that international students misinterpreted key terms such as faculty members and had subtle but important differences in their perceptions of student behaviours and institutional practices compared to the perceptions of Canadian students.
Interacting Holographic dark energy in chameleon tachyon cosmology
Creators: name: Farajollahi, H.
name: Ravanpak, A.
name: Fadakar, G. Farpour
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We propose in this paper an interacting holographic dark energy (IHDE) model in chameleon--tachyon cosmology by interaction between the components of the dark sectors. In the formalism, the interaction term emerges from the scalar field coupling matter lagrangian in the model rather than being inserted into the formalism as an external source for the interaction. The correspondence between the tachyon field and the holographic dark energy (HDE) densities allows to reconstruct the tachyon scalar field and its potential in a flat FRW universe. The model can show the accelerated expansion of the universe and satisfies the observational data.
description: 12 pages, 12 figures; will be published in Astrophys. Space Sci
Yang-Mills instantons and dyons on homogeneous G_2-manifolds
Creators: name: Bauer, Irina
name: Ivanova, Tatiana A.
name: Lechtenfeld, Olaf
name: Lubbe, Felix
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider Lie G-valued Yang-Mills fields on the space R x G/H, where G/H is a compact nearly K"ahler six-dimensional homogeneous space, and the manifold R x G/H carries a G_2-structure. After imposing a general G-invariance condition, Yang-Mills theory with torsion on R x G/H is reduced to Newtonian mechanics of a particle moving in R^6, R^4 or R^2 under the influence of an inverted double-well-type potential for the cases G/H = SU(3)/U(1)xU(1), Sp(2)/Sp(1)xU(1) or G_2/SU(3), respectively. We analyze all critical points and present analytical and numerical kink- and bounce-type solutions, which yield G-invariant instanton configurations on those cosets. Periodic solutions on S^1 x G/H and dyons on iR x G/H are also given.
description: 1+26 pages, 14 figures, 6 miniplots
Music and movement : the influence of tempo on the mirror neuron system in children
Creators: name: Evanchu Hilderman, Courtney
Publisher: name: University of British Columbia
Year: 2015

description: BACKGROUND: The mirror neuron system (MNS) is a neurological network associated with action-perception coupling, and is influenced by previous experiences. Visual, auditory, multi-modal, congruent and incongruent stimuli have been shown to modulate the response of the MNS throughout the various stages of human development. The musical attribute of tempo may exert a specific influence on action perception but this has not been studied in children. PURPOSE: The overarching purpose of this research is to explore the neurological interactions of music and action. This study asks the question, “How does the tempo of regular pulse influence perception of action in children?” METHODS: This research reflected on music and the MNS within the framework of dynamic systems theory (DST). A literature review examined the research relevant to the study question. Finally, a pilot study compared the responses in the MNS of 10 children during exposure to stimuli with tempi of 40 beats per minute (BPM) and 173BPM by examining the relative power of the mu rhythm frequency band (8-13Hz) in the sensorimotor cortex. RESULTS: Previous research suggests tempo significantly influences executed movements, cortical excitability, perception of emotion in music, and perception of synchrony in audio-visual stimuli. The pilot study identified significant mu suppression in the left sensorimotor cortex during visual conditions only, whereas the right sensorimotor cortex demonstrated significant mu suppression during auditory, visual and multi-modal conditions. In the left hemisphere, visual stimuli showed significantly greater mu suppression than auditory stimuli. In the right hemisphere, visual stimuli with a tempo of 173BPM showed significantly greater mu suppression than auditory stimuli with a tempo of 40BPM. The covariates of age, musical experience and dance experience were identified to have significant interactions with conditions. CONCLUSIONS: This pilot study provided the first evidence that visual stimuli result in stronger mu suppression compared to auditory stimuli in typically developing children, similar to that found in adults. Increased tempo was associated with stronger action-perception coupling for uni-modal stimuli. This study lacked statistical power to demonstrate differences between multi-modal stimuli exhibiting equivalent or differing tempi; further research with larger samples is needed to explore these influences.
Supplementary Materials from Reputation and punishment sustain cooperation in the optional public goods game
Creators: name: Podder, Shirsendu
name: Righi, Simone
name: Pancotto, Francesca
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 60801 Animal Behaviour

description: Additional analyses accompanying the findings in the paper.
Convergence and Next Generation Networks
Creators: name: Sen, Jaydip
name: Sayyad, Munir
name: Hooli, Basavaraj
Publisher: name: arXiv
Year: 2010
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: The communications sector is undergoing significant changes, with the emergence of a number of platforms available to provide a different range of services. Some of these platforms are complementary to each other, while others are competitive, or can provide a valid substitute for some of the services provided. Up till now, the most important communications platform in most of the developing countries has been the public switched telecommunication network (PSTN) which provides access to all households and buildings. This universality in providing access has also meant that the network has generally been designated as one for universal service.This chapter focuses on the area where the most significant changes are taking place in the communication sector. The objective of this chapter is neither to give an overview of all communication platforms, nor is it aimed to assess the relative extent to which different platforms complement or compete with each other. The central theme of this chapter is to examine the developments in what is commonly refereed to as next generation access networks and next generation core networks and their role in convergence.
description: 67 pages, 11 figures, 4 tables. Bootk Chapter published in the book "Future trends and Challenegs for ICT Standardization", pp. 107 - 192
Gravity triggered neutrino condensates
Creators: name: Barenboim, Gabriela
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In this work we use the Schwinger-Dyson equations to study the possibility that an enhanced gravitational attraction triggers the formation of a right handed neutrino condensate, inducing dynamical symmetry breaking and generating a Majorana mass for the right handed neutrino at a scale appropriate for the see-saw mechanism. The composite field formed by the condensate phase could drive an early epoch of inflation. We find that to the lowest order, the theory does not allow dynamical symmetry breaking. Nevertheless, thanks to the large number of matter fields in the model, the suppression by additional powers in G of higher order terms can be compensated, boosting them up to their lowest order counterparts. This way chiral symmetry can be broken dynamically and the infrared mass generated turns out to be in the expected range for a successful see-saw scenario.
description: 16 pages, 10 figures
Asymptotic of grazing collisions and particle approximation for the Kac equation without cutoff
Creators: name: Fournier, Nicolas
name: Godinho, David
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The subject of this article is the Kac equation without cutoff. We first show that in the asymptotic of grazing collisions, the Kac equation can be approximated by a Fokker-Planck equation. The convergence is uniform in time and we give an explicit rate of convergence. Next, we replace the small collisions by a small diffusion term in order to approximate the solution of the Kac equation and study the resulting error. We finally build a system of stochastic particles undergoing collisions and diffusion, that we can easily simulate, which approximates the solution of the Kac equation without cutoff. We give some estimates on the rate of convergence.
description: 37 pages, 6 figures
On the Asymptotic Stability of De-Sitter Spacetime: a non-linear perturbative approach
Creators: name: Mena, Filipe C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We derive evolution and constraint equations for second order perturbations of flat dust homogeneous and isotropic solutions to the Einstein field equations using all scalar, vector and tensor perturbation modes. We show that the perturbations decay asymptotically in time and that the solutions converge to the De-Sitter solution. By induction, this result is valid for perturbations of arbitrary order. This is in agreement with the cosmic no-hair conjecture of Gibbons and Hawking.
description: 11 pages, 2 figures
Spin-flip inelastic electron tunneling spectroscopy in atomic chains
Creators: name: Hurley, Aaron
name: Baadji, Nadjib
name: Sanvito, Stefano
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a theoretical study of the spin transport properties of mono-atomic magnetic chains with a focus on the spectroscopical features of the I-V curve associated to spin-flip processes. Our calculations are based on the s-d model for magnetism with the electron transport treated at the level of the non-equilibrium Green's function formalism. Inelastic spin-flip scattering processes are introduced perturbatively via the first Born approximation and an expression for the associated self-energy is derived. The computational method is then applied to describe the I-V characteristics and its derivatives of one dimensional chains of Mn atoms and the results are then compared to available experimental data. We find a qualitative and quantitative agreement between the calculated and the experimental conductance spectra. Significantly we are able to describe the relative intensities of the spin excitation features in the I-V curve, by means of a careful analysis of the spin transition selection rules associated to the atomic chains.
56Ni Production in Double Degenerate White Dwarf Collisions
Creators: name: Raskin, Cody
name: Scannapieco, Evan
name: Rockefeller, Gabriel
name: Fryer, Chris
name: Diehl, Steven
name: Timmes, F. X.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present a comprehensive study of white dwarf collisions as an avenue for creating type Ia supernovae. Using a smooth particle hydrodynamics code with a 13-isotope, α-chain nuclear network, we examine the resulting 56Ni yield as a function of total mass, mass ratio, and impact parameter. We show that several combinations of white dwarf masses and impact parameters are able to produce sufficient quantities of 56Ni to be observable at cosmological distances. We find the 56Ni production in double-degenerate white dwarf collisions ranges from sub-luminous to the super-luminous, depending on the parameters of the collision. For all mass pairs, collisions with small impact parameters have the highest likelihood of detonating, but 56Ni production is insensitive to this parameter in high-mass combinations, which significantly increases their likelihood of detection. We also find that the 56Ni dependence on total mass and mass ratio is not linear, with larger mass primaries producing disproportionately more 56Ni than their lower mass secondary counterparts, and symmetric pairs of masses producing more 56Ni than asymmetric pairs.
description: 21 pages, 21 figures; ApJ in press
Pseudo-Bosons from Landau Levels
Creators: name: Bagarello, Fabio
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We construct examples of pseudo-bosons in two dimensions arising from the Hamiltonian for the Landau levels. We also prove a no-go result showing that non-linear combinations of bosonic creation and annihilation operators cannot give rise to pseudo-bosons.
description: Proceedings of the Workshop "Supersymmetric Quantum Mechanics and Spectral Design", Benasque, 2010
Anaerobic corrosion of carbon steel in compacted bentonite exposed to natural opalinus clay porewater: bentonite alternation study
Creators: name: Morelová, Nikoleta
name: Schild, Dieter
name: Heberling, Frank
name: Finck, Nicolas
name: Dardenne, Kathy
name: Metz, Volker
name: Geckeis, Horst
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2021
Subjects: Bentonite
Corrosion
Steel
XAS

description: Carbon steel is a potential canister material for the disposal of high-level radioactive waste in deep geological repositories in clays and clay rocks. Bentonite is considered as a potential backfill material for those multi-barrier systems. To predict the long-term performance and for safety assessment the knowledge of canister corrosion behavior is important. The formed corrosion products and mineralogically altered bentonite at the canister/bentonite interface can potentially provide an additional barrier against radionuclide migration. In-situ corrosion experiments were performed at the Mt. Terri underground research laboratory. Coupons of carbon steel were embedded in Volclay MX-80 bentonite with controlled densities, installed in a borehole under simulated repository and anaerobic conditions and exposed to natural Opalinus Clay porewater for a period up to 5.5 years. The bentonite layer at the canister/bentonite interface was characterized by complementary microscopic and spectroscopic techniques (XPS, SEM-EDX, XRD) under anoxic conditions. The interface revealed reddish-brown staining up to 2 mm depth into the bentonite in the zone adjacent to the steel. The SEM-EDX analyses of the interface (embedded crosscut with steel removed) showed calcium and iron enrichment in the bentonite adjacent to the metal. µXRF analysis performed on the bentonite at the interface showed calcium enriched rim up to 100 µm into the bentonite, while µXANES analysis revealed formation of iron silicate compounds in the reacted reddish-brown zone. The steel coupon was removed prior embedding. A line scan from the edge towards bulk bentonite did not indicate any systematic gradient in the Fe2+ / Fe3+ ratio. The formation of mixed Fe2+/3+ silicate compounds appears to be heterogeneous. This work contributes to an increased understanding of steel corrosion mechanisms in clay, which can improve the robustness of canister lifetime predictions. We acknowledge the German Federal Ministry of Education and Research (BMBF) and the Helmholtz association for the financial support. We thank the Mont Terri IC-A Partners and Swisstopo for providing the samples. We acknowledge the provision of the beamtime at the KIT Light Source, KARA, Germany.
Investigation and evaluation of contamination in dredged reclaimed land in China
Creators: name: Wang, Jianxiu
name: Wu, Linbo
name: Deng, Yansheng
name: Song, Dongsheng
name: Liu, Wuji
name: Hu, Mingzhi
name: Liu, Xiaotian
name: Zhou, Jie
Publisher: name: Taylor & Francis
Year: 2017
Subjects: subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Science Policy

description: Large-scale reclamation projects have been developing rapidly in China’s coastal lands since 2000. In this study, the scale and pollutant contents of reclaimed lands were collected from published data and field surveys. Over 80% of the gross area was formed using hydraulic reclaimed technology. The pollution index, geoaccumulation index, and Nemerow integrated pollution index (NIPI) of 13 pollutant types were calculated based on the collected data. The potential pollution within major newly reclaimed lands was evaluated with valid pollutant data from sediments of the neighboring water. All reclaimed lands larger than 30 km2 were slightly to seriously polluted with Cu, Pb, Zn, Cd, Cr, Hg, As, and Ni according to NIPI. The reclaimed fields in Hengsha Island, Binhai Tower, and Lingang New City of Shanghai were selected as verification sites for the pollution evaluations. The Cu, Pb, Zn, Cd, Cr, As, and Ni concentrations in dredged soils determined through inductively coupled plasma mass spectrometry showed a generally good soil quality within the typical reclaimed fields. Principal component and hierarchical clustering analyses indicated that the relatively high As content in the reclaimed soils was due to the internal pollutants of dredging fills and originated from anthropogenic sources.
Nonlocality-induced front interaction enhancement
Creators: name: Gelens, Lendert
name: Gomila, Damia
name: Van der Sande, Guy
name: Matias, Manuel A.
name: Colet, Pere
Publisher: name: arXiv
Year: 2011
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We demonstrate that nonlocal coupling strongly influences the dynamics of fronts connecting two equivalent states. In two prototype models we observe a large amplification in the interaction strength between two opposite fronts increasing front velocities several orders of magnitude. By analyzing the spatial dynamics we prove that way beyond quantitative effects, nonlocal terms can also change the overall qualitative picture by inducing oscillations in the front profile. This leads to a mechanism for the formation of localized structures not present for local interactions. Finally, nonlocal coupling can induce a steep broadening of localized structures, eventually annihilating them.
description: 4 pages, 6 figures
RECENT REFORM IN LAWS AND POLICIES RELATING TO PRISON CONDITIONS FOR WOMEN IN THE UNITED KINGDOM AND THE UNITED STATES: A COMPARISON
Creators: name: Suphat Phoophanichjaroenkul
Publisher: name: National Research Council of Thailand
Year: 2021
Subjects: Prison Conditions
Female Offender
FIRST STEP Act
Bangkok Rules

description: SOCIAL SCIENCE ASIA : Official Journal of National Research Council of Thailand in conjunction with Journal of Thai Justice System, 7, 3, 1-19
Errare humanum est, sed etiam perseverare
Creators: name: Salvador, Silvano
Publisher: name: Knowledge Commons
Year: 2025
Subjects: subject: Cartography

description: Nel 2024 è stato pubblicato per i tipi della Padova University Press un volume intitolato "Le fonti nella fonte. L'Italia fisica nella descrizione della Tabula Peutingeriana", che raccoglie alcuni contributi di Guido Rosada apparsi negli ultimi anni sulle caratteristiche della Tabula Peutingeriana dal punto di vista della geografia fisica...