cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Identifying and modeling patterns of tetrapod vertebrate mortality rates in the Gulf of Mexico oil spill
Creators: name: Antonio, F. J.
name: Mendes, R. S.
name: Thomaz, S. M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: The accidental oil spill in the Gulf of Mexico in 2010 has caused perceptible damage to marine and freshwater ecosystems. The large quantity of oil leaking at a constant rate and the long duration of the event caused an exponentially increasing mortality of vertebrates. Using data provided by NOAA and USFWS, we assessed the effects of this event on birds, sea turtles, and mammals. Mortality rates (measured as the number of carcasses recorded per day) were exponential for all three groups. Birds were the most affected group, as indicated by the steepest increase of mortality rates over time. For sea turtles and mammals, an exponential increase in mortality was observed after an initial delay. These exponential behaviors are consistent with a unified scenario for the mortality rate for tetrapod vertebrates. However, at least for mammals, pre-spill data seem to indicate that the growth in the mortality rate is not entirely a consequence of the spill.
description: 4 pages, 1 figure
Measurement of Doppler effects in cryogenic buffer-gas cell
Creators: name: Hiramoto, Ayami
name: Baba, Masaaki
name: Enomoto, Katsunari
name: Iwakuni, Kana
name: Kuma, Susumu
name: Takahashi, Yuiki
name: Tobaru, Reo
name: Miyamoto, Yuki
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Buffer-gas cooling is a universal cooling technique for molecules and used for various purposes. One of its applications is using molecules inside a buffer-gas cell for low-temperature spectroscopy. Although a high-intensity signal is expected in the cell, complex molecular dynamics is a drawback for precise spectroscopy. In this study, we performed high-resolution absorption spectroscopy of low-J transitions in the $\tilde{A}^2Π(0,0,0)-\tilde{X}^2Σ^+(0,0,0)$ band of calcium monohydroxide (CaOH). CaOH molecules were produced by laser ablation in a copper cell and cooled to $\sim$5\,K using helium buffer gas. We probed the Doppler effects in a buffer-gas cell by injecting counter-propagating lasers inside the cell. The time evolutions of the Doppler width and shift were simulated using a dedicated Monte Carlo simulation and compared with data.
description: 5 pages, 5 figures
Normal forms approach to diffusion near hyperbolic equilibria
Creators: name: Monter, Sergio Angel Almada
name: Bakhtin, Yuri
Publisher: name: arXiv
Year: 2010
Subjects: subject: Probability (math.PR)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 60H10, 60J60, 37J40

description: We consider the exit problem for small white noise perturbation of a smooth dynamical system on the plane in the neighborhood of a hyperbolic critical point. We show that if the distribution of the initial condition has a scaling limit then the exit distribution and exit time also have a joint scaling limit as the noise intensity goes to zero. The limiting law is computed explicitly. The result completes the theory of noisy heteroclinic networks in two dimensions. The analysis is based on normal forms theory.
description: 21 pages
PNRR: le nuove sfide per migliorare la qualità della regolazione
Creators: name: Rubechi, Massimo
Publisher: name: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche
Year: 2022

description: L’ambiziosa programmazione pluriennale prevista dal Piano Nazionale di Ripresa e Resilienza (PNRR) richiede non soltanto una rivoluzione della gestione processi decisionali, ma anche una rinnovata attenzione agli atti utilizzati per porli in essere, alla qualità e all’impatto di questi ultimi nell’ordinamento. Diviene così centrale il tema della qualità della normazione. Tema che il contributo analizza rispetto alle sue declinazioni all’interno dello stesso PNRR, prospettando anche come il cambio di paradigma richiesto per l’attuazione delle misure del PNRR potrebbe incidere sulla forma di governo.
description: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche, V. 72 N. 3-4 (2021): Il diritto della resilienza. Legge, società e politiche economiche nel PNRR
Tactical Voting in Plurality Elections
Creators: name: Araújo, Nuno A. M.
name: Andrade, José S.
name: Herrmann, Hans J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: How often will elections end in landslides? What is the probability for a head-to-head race? Analyzing ballot results from several large countries rather anomalous and yet unexplained distributions have been observed. We identify tactical voting as the driving ingredient for the anomalies and introduce a model to study its effect on plurality elections, characterized by the relative strength of the feedback from polls and the pairwise interaction between individuals in the society. With this model it becomes possible to explain the polarization of votes between two candidates, understand the small margin of victories frequently observed for different elections, and analyze the polls' impact in American, Canadian, and Brazilian ballots. Moreover, the model reproduces, quantitatively, the distribution of votes obtained in the Brazilian mayor elections with two, three, and four candidates.
description: 7 pages, 4 figures
Gauge/string duality applied to heavy ion collisions: Limitations, insights and prospects
Creators: name: Mateos, David
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Over the last decade a fruitful interplay has developed between analyses of strongly coupled non-abelian plasmas via the gauge/string duality and the phenomenology of the quark-gluon plasma created in heavy ion collisions. I review the reasons why the gauge/string duality is not a precision tool for QCD physics at present, with emphasis on conceptual issues. I then argue that, nevertheless, the duality can provide valuable insights at both the quantitive and the qualitative level. I illustrate this with a few examples, and conclude with a brief discussion of future prospects.
description: 8 pages. Plenary talk at "Quark Matter 2011", Annecy, France
sistema penale resiliente e «l’argine rotto al torrente delle opinioni». Profli ordinamentali
Creators: name: Marra, Gabriele
Publisher: name: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche
Year: 2022

description: Il lavoro intende approfondire alcune linee di riforma emergenti dal PNRR in materia penale. A partire dalla non scontata collocazione dell’impegno riformistico nel quadro di finalità di crescita economica, che alla riforma indicano scopi e necessità, verrà indagata, nella prospettiva fissata dal principio di efficienza, la correlazione tra il funzionamento del sistema penale (sostanziale e processuale) e alcuni aspetti dell’organizzazione giudiziaria.
description: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche, V. 72 N. 3-4 (2021): Il diritto della resilienza. Legge, società e politiche economiche nel PNRR
Additional file 4 of Effects of mouth breathing on facial skeletal development in children: a systematic review and meta-analysis
Creators: name: Zhao, Ziyi
name: Zheng, Leilei
name: Huang, Xiaoya
name: Li, Caiyu
name: Liu, Jing
name: Hu, Yun
Publisher: name: figshare
Year: 2021
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Inorganic Chemistry
subject: FOS: Chemical sciences

description: Additional file 4: Forest plot of mouth breathing caused by adenoid/tonsil hypertrophy.
Real-time quantum error correction beyond break-even
Creators: name: Sivak, V. V.
name: Eickbusch, A.
name: Royer, B.
name: Singh, S.
name: Tsioutsios, I.
name: Ganjam, S.
name: Miano, A.
name: Brock, B. L.
name: Ding, A. Z.
name: Frunzio, L.
name: Girvin, S. M.
name: Schoelkopf, R. J.
name: Devoret, M. H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The ambition of harnessing the quantum for computation is at odds with the fundamental phenomenon of decoherence. The purpose of quantum error correction (QEC) is to counteract the natural tendency of a complex system to decohere. This cooperative process, which requires participation of multiple quantum and classical components, creates a special type of dissipation that removes the entropy caused by the errors faster than the rate at which these errors corrupt the stored quantum information. Previous experimental attempts to engineer such a process faced an excessive generation of errors that overwhelmed the error-correcting capability of the process itself. Whether it is practically possible to utilize QEC for extending quantum coherence thus remains an open question. We answer it by demonstrating a fully stabilized and error-corrected logical qubit whose quantum coherence is significantly longer than that of all the imperfect quantum components involved in the QEC process, beating the best of them with a coherence gain of $G = 2.27 \pm 0.07$. We achieve this performance by combining innovations in several domains including the fabrication of superconducting quantum circuits and model-free reinforcement learning.
Localised HI 21-cm absorption towards a double-lobed z=0.24 radio galaxy
Creators: name: Curran, S. J.
name: Whiting, M. T.
name: Webb, J. K.
name: Athreya, R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the results of a mini-survey for associated HI 21-cm absorption at z < 0.42 with the Giant Metrewave Radio Telescope. Our targets are radio galaxies, selected on the basis that the 1216 Angstrom luminosities are below 10^23 W/Hz, above which there has never been a detection of 21-cm absorption. Of the three sources for which we obtained good data, two are unclassified active galactic nuclei (AGN) and one is type-2. Being a non-detection, the type-2 object is consistent with our previous result that 21-cm absorption in radio sources is not dictated by unified schemes of AGN. In the case of the detection, the absorption only occurs towards one of the two resolved radio lobes in PKS 1649-062. If the absorption is due to an another intervening galaxy, or cool HI gas in the intergalactic medium, covering only the south-west lobe, then, being at the same redshift, this is likely to be gravitationally bound to the optical object identified as PKS 1649-062. If the absorption is due to an inclined disk centred between the lobes, intervening the SW lobe while being located behind the NE lobe, by assuming that it covers the emission peak at 150 kpc from the nucleus, we estimate a dynamical mass of ~3 x 10^12 solar masses for the disk.
description: 5 pages accepted by MNRAS Letters
Excitonic beam steering in an active van der Waals metasurface
Creators: name: Li, Melissa
name: Hail, Claudio U.
name: Biswas, Souvik
name: Atwater, Harry A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Two-dimensional transition metal dichalcogenides (2D TMDCs) are promising candidates for ultra-thin active nanophotonic elements due to the strong tunable excitonic resonances that dominate their optical response. Here we demonstrate dynamic beam steering by an active van der Waals metasurface that leverages large complex refractive index tunability near excitonic resonances in monolayer molybdenum diselenide (MoSe2). Through varying the radiative and nonradiative rates of the excitons, we can dynamically control both the reflection amplitude and phase profiles, resulting in an excitonic phased array metasurface. Our experiments show reflected light steering to angles between -30° to 30° at three different resonant wavelengths corresponding to the A exciton, B exciton, and trion. This active van der Waals metasurface relies solely on the excitonic resonances of the monolayer MoSe2 material rather than geometric resonances of patterned nanostructures, suggesting the potential to harness the tunability of excitonic resonances for wavefront shaping in emerging photonic applications.
On the location of spectral edges in $\mathbb{Z}$-periodic media
Creators: name: Exner, Pavel
name: Kuchment, Peter
name: Winn, Brian
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: Spectral Theory (math.SP)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 35P99, 35Q99, 47F05, 58J50, 81Q10, 05C99

description: Periodic $2$nd order ordinary differential operators on $\R$ are known to have the edges of their spectra to occur only at the spectra of periodic and antiperiodic boundary value problems. The multi-dimensional analog of this property is false, as was shown in a 2007 paper by some of the authors of this article. However, one sometimes encounters the claims that in the case of a single periodicity (i.e., with respect to the lattice $\mathbb{Z}$), the $1D$ property still holds, and spectral edges occur at the periodic and anti-periodic spectra only. In this work we show that even in the simplest case of quantum graphs this is not true. It is shown that this is true if the graph consists of a $1D$ chain of finite graphs connected by single edges, while if the connections are formed by at least two edges, the spectral edges can already occur away from the periodic and anti-periodic spectra.
description: 9 pages, 5 figures
A Preconcentrating Lab-on-a-Chip Device Targeted Towards Nanopore Sensors
Creators: name: Kean, Kaitlyn
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2020
Subjects: Nanopore
Microfluidics
Lab-on-a-chip
Preconcentration

description: Continuous progress in the nanotechnology field has allowed for the emergence of powerful, nanopore-based detection technology. Solid-state nanopores were developed for next-generation sequencing and single-molecule detection. They are advantageous over their biological counterpart because they offer robustness, stability, tunable pore size and the ability to be integrated within a microfluidic device. With all of these attractive attributes, solid-state nanopores are a top contender for point-of-care diagnostic technologies. However, hindering their performance is an inability to distinguish between small molecules, pore-clogging, and the detection rate's dependence on sample concentration. The concentration-dependent detection rate becomes particularly evident at low sample concentrations (<1 nM), sometimes taking hours for the nanopore to sense a single molecule because of diffusion. The inability to distinguish between small molecules can be addressed using DNA nanostructures; however, pore-clogging and variable detection rates hinder its potential in a clinical setting. This thesis proposes a microfluidic device design and methodology that seeks to mitigate pore-clogging and improve the detection rate for dilute samples. DNA coated microbeads will create a bead column within the microfluidic device and confine the target molecules to an extremely small (20 nL) volume. The sample can be washed, ridding the contaminants, and eluted on-chip, so the sample is purified and concentrated, affording a more reliable sensing performance. First, a magnetic microbead DNA assay was optimized off-chip, and the capture and release efficiencies were monitored using a Biotek™ Epoch™ 2 spectrophotometer (Chapter 2). Next, a novel microfluidic device design was optimized and validated to ensure precise sample manipulation (Chapter 3). Finally, the microbead assay was incorporated into the microfluidic device for sample concentration (Chapter 4). Fluorescence microscopy results suggest successful DNA elution from the microbeads within the microfluidic device, allowing for a 28.5 X concentration increase. This platform shows promise for sample preconcentration by reducing the starting DNA sample volume of 25 µL to 20 nL, which could improve the speed of solid-state nanopore sensing.
Bi-chromatic driver enabled control of high harmonic generation in atomic targets
Creators: name: Rajpoot, Rambabu
name: Holkundkar, Amol R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We investigated the high-order harmonic generation by interacting time-delayed, linearly polarized bi-chromatic laser pulses with the atomic target. The frequency ratio of secondary to primary fields ($ω_2/ω_1$), along with the relative carrier-envelope-phase (CEP) and respective time-delay between the two pulses, are very instrumental in controlling the ionization of the electron and so the quantum dynamics in continuum. We observed an optimum CEP ($ϕ$) and time delay ($t_d$) for a given bi-chromatic frequency ratio, giving maximum cutoff energy. We studied the effect of CEP and time delay for fixed frequency ratio and observed that the harmonic cutoff could be controlled in an experimentally feasible way. Moreover, the harmonic yield in the energy range 140 eV $-$ 240 eV is also calculated, and it is observed that the harmonic yield scales as $\propto -\sqrtϕ$. The attosecond pulses for different CEP is also calculated by superposing the harmonics in the same energy range, and $\sim 200$ as pulses are observed with peak intensity decreasing with CEP, following the variation of respective harmonic yield with CEP.
description: 7 pages, 7 figures
Computing First-Passage Times with the Functional Renormalisation Group
Creators: name: Rigopoulos, Gerasimos
name: Wilkins, Ashley
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We use Functional Renormalisation Group (FRG) techniques to analyse the behaviour of a spectator field, $σ$, during inflation that obeys an overdamped Langevin equation. We briefly review how a derivative expansion of the FRG can be used to obtain Effective Equations of Motion (EEOM) for the one- and two-point function and derive the EEOM for the three-point function. We show how to compute quantities like the amplitude of the power spectrum and the spectral tilt from the FRG. We do this explicitly for a potential with multiple barriers and show that in general many different potentials will give identical predictions for the spectral tilt suggesting that observations are agnostic to localised features in the potential. Finally we use the EEOM to compute first-passage time (FPT) quantities for the spectator field. The EEOM for the one- and two-point function are enough to accurately predict the average time taken $\left\langle \mathcal{N}\right\rangle$ to travel between two field values with a barrier in between and the variation in that time $δ\mathcal{N}^2$. It can also accurately resolve the full PDF for time taken $ρ(\mathcal{N})$, predicting the correct exponential tail. This suggests that an extension of this analysis to the inflaton can correctly capture the exponential tail that is expected in models producing Primordial Black Holes.
description: 24 pages, 8 figures, 2 tables, 1 Appendix. V2 includes some minor changes to the text to match the upcoming publication in JCAP
Coincidence sets in quasilinear elliptic problems of monostable type
Creators: name: Takeuchi, Shingo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35J92 (Primary), 35R35 (Secondary)

description: This paper concerns the formation of a coincidence set for the positive solution of $p$-Laplacian elliptic problems of monostable type. It is proved that for any small parameter of diffusion term, the solution coincides with the stable zero-function $a(x)$ of reaction term in an open set if $a(x)$ is $p$-harmonic (but, not constant) and a zero of order less than 1. Inversely, it is also shown that the solution is less than $a(x)$ if $a(x)$ is a zero of order greater than or equal to 1. The proof rely on comparison theorems and an energy method for obtaining local comaprison functions.
description: 18 pages
Lineamenti e prospettive di riforma della giustizia tributaria
Creators: name: Mazza, Marilisa
Publisher: name: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche
Year: 2022

description: Il presente lavoro affronta uno dei temi fondamentali del PNRR in ambito tributario; il ripensamento dell’attuale sistema della giustizia tributaria ha ovvi importati effetti in termini dell’interesse pubblico, della tutela del contribuente dell’attrazione degli investimenti esteri. La riforma della giustizia tributaria immaginata nel PNRR ha un unico filo condutture che però attraversa le più fasi della relazione tra Amministrazione e contribuente e tiene in considerazione, oltre che alla modifica di aspetti procedurali per evitare e ridurre il contenzioso e migliorare i tempi del processo, anche aspetti inerenti le nuove tecnologie, il gap informativo e la mancanza di personale in organico. Insieme al PNRR viene esaminata anche la documentazione predisposta dalla Commissione interministeriale per la riforma della giustizia tributaria, che approfondisce nel concreto le misure da porre in essere nel rispetto degli obiettivi prefissati nel PNRR identificando modalità e tempistiche
description: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche, V. 72 N. 3-4 (2021): Il diritto della resilienza. Legge, società e politiche economiche nel PNRR
Muon $g-2$ in a 2HDM assisted by inert scalars: probing at the ILC
Creators: name: Chakrabarty, Nabarun
name: Chakraborty, Indrani
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A Two-Higgs doublet model (2HDM) can predict the observed muon $g-2$ for an appropriately light pseudoscalar that now faces tight constraints. However, It was shown in past that augmenting the 2HDM by an additional inert doublet can lead to an explanation to the muon $g-2$ anomaly for a much heavier pseudoscalar. In this study, we probe such a framework at the proposed International Linear Collider (ILC) using beam polarization for $\sqrt{s}$ = 1 TeV. Using multivariate techniques, we analyse the signals $e^+ e^- \rightarrow τ^+ τ^- +$ missing transverse energy and $e^+ e^- \rightarrow μ^+ μ^- + $ missing transverse energy in the lepton- and muon-specific versions of the framework respectively. Our analysis reveals that the $e^+ e^-$ machine operating at a 3000 fb$^{-1}$ luminosity predicts a 5$σ$ discovery of a pseudoscalar as heavy as 400 GeV. Comparing with the previous study, it is concluded that the ILC is a much more potent machine than the LHC in this regard.
description: 31 pages + references, 15 captioned figures, 13 tables
PNRR e giustizia civile
Creators: name: Giussani, Andrea
Publisher: name: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche
Year: 2022

description: Le prossime riforme della giustizia civile italiana mirano ad accelerare le definizione dei giudizi e ridurre l'arretrato. Fra le principali innovazioni rientrano: l'anticipazione delle preclusioni rispetto alla prima udienza; ulteriori incentivi alla risoluzione alternativa delle controversie; la generalizzazione della tutela anticipatoria non cautelare; la definibilità dell'appello in sede di inibitoria; la prosecuzione oltre la pandemia delle prassi di riduzione dell'oralità delle udienze
description: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche, V. 72 N. 3-4 (2021): Il diritto della resilienza. Legge, società e politiche economiche nel PNRR
Phases of the infinite U Hubbard model
Creators: name: Liu, Li
name: Yao, Hong
name: Berg, Erez
name: Kivelson, Steven A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We apply the density matrix renormalization group (DMRG) to study the phase diagram of the infinite U Hubbard model on 2-, 4-, and 6-leg ladders. Where the results are largely insensitive to the ladder width, we consider the results representative of the 2D square lattice model. We find a fully polarized ferromagnetic Fermi liquid phase when n, the density of electrons per site, is in the range 1>n>n_F ~ 4/5. For n=3/4 we find an unexpected commensurate insulating "checkerboard" phase with coexisting bond density order with 4 sites per unit cell and block spin antiferromagnetic order with 8 sites per unit cell. For 3/4 > n, the wider ladders have unpolarized groundstates, which is suggestive that the same is true in 2D.
cammino delle riforme della pubblica amministrazione nella svolta pragmatica del PNRR
Creators: name: Giannelli, Nicola
Publisher: name: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche
Year: 2022

description: La riforma della pubblica amministrazione è un obiettivo finale del PNRR nella misura in cui un guadagno di efficienza della macchina amministrativa è necessario all'incremento di produttività dell'economia italiana che è lo scopo principale del piano. Essa è però anche uno obiettivo strumentale perché la realizzazione degli obiettivi finali richiede un incremento dell'efficacia amministrativa pubblica. Tenendo conto dei risultati sempre parziali delle riforme strutturali della pubblica amministrazione iniziate negli anni '90, il Governo ha scelto di non continuare su quella strada, ma di concentrarsi sulla semplificazione di specifiche procedure, sull'accorciamento delle scadenze decisionali, sul supporto di staff e competenze agli enti locali nella implementazione, su una nuova gestione del personale pubblico, e su una governance che permette al Governo di sostituire gli uffici pubblici di ogni livello quando rallentano la procedura esecutiva. Tutto questo è incluso in una cornice complessiva di digitalizzazione che dovrebbe fornire i canali per l'efficientamento. Il rischio di questa strategia è che il forte orientamento alla capacità di spesa spinga a trascurare la qualità della spesa, cosa che invece sarà cruciale quando le risorse pubbliche torneranno ad essere scarse.
description: Studi Urbinati, A - Scienze giuridiche, politiche ed economiche, V. 72 N. 3-4 (2021): Il diritto della resilienza. Legge, società e politiche economiche nel PNRR
Regularity of solutions to the Muskat equation
Creators: name: Shi, Jia
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper, we show that if a solution to the Muskat problem in the case of different densities and the same viscosity is sufficiently smooth, then it must be analytic except at the points where a turnover of the fluids happens.
title: Examining Melt Pond Dynamics and Light Availability in the Arctic Ocean via High Resolution Satellite Imagery
Creators: name: Abbott, Austin Wesley
Publisher: name: Old Dominion University Libraries
Year: 2021

description: As the Arctic experiences consequences of climate change, a shift from thicker, multi-year ice to thinner, first-year ice has been observed. First-year ice is prone to extensive pools of meltwater (“melt ponds”) forming on its surface, which enhance light transmission to the ocean. Changes in the timing and distribution of melt pond formation and associated increases in under-ice light availability are the primary drivers for seasonal progression of water column primary production and warming. Observations of melt pond development and distribution require meter scale resolution and have traditionally been limited to airborne images. However, recent advances in high spatial resolution satellites now allow for observations of individual melt ponds from space.

Images of pack ice in the Chukchi Sea during 2018 obtained from WorldView satellite systems showed minimal melt pond coverage in June, with a rapid increase in late June, leading to saturated and flooded ice floes by mid-July. Cumulative hours above freezing (air temperature) was a stronger predictor for pond development than daily average values of temperature and irradiance and was well represented by a logistic growth curve.

Size distributions (normalized to total pond area) of melt pond area was dominated by small (≤10 m2) ponds at the onset of ponding, shifting towards medium sized ponds (mode of 100 to 1,000 m2) as surface melt progressed. Late in the summer when ice flows were saturated with ponds, the distribution was skewed towards a handful of very large ponds nearing 1,000,000 m2, connected by channels which created a myriad of complex shapes.

A primary production model driven by under-ice light intensity estimated from our classified images revealed that initial small increases in melt pond fraction have a large impact on potential under-ice chlorophyll growth and carbon uptake, eventually trending towards a saturating upper limit as ponds continued to spread. Results shown here offer novel insights into melt pond growth and distribution, along with estimates of how ponding impacts primary production. These conclusions showcase physical, observable consequences of an Arctic Ocean dominated by thin, first-year ice, and can be employed to advise future efforts in Arctic modeling.
Properties of the gauge invariant quark Green's function in two-dimensional QCD
Creators: name: Sazdjian, H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Using an exact integrodifferential equation we study the properties of the gauge invariant quark Green's function, defined with a path-ordered gluon field phase factor along a straight line, in two-dimensional QCD in the large-N_c limit. The Green's function is found to be infrared finite with singularities represented by an infinite number of threshold type branch points with a power equal to -3/2, starting at positive mass squared values. The solution is analytically determined.
description: 3 pages, 2 figures. Talk given at the Conference QCD 10, 28 June - 2 July 2010, Montpellier, France
Hollow Hydrogel Cocoons for the Encapsulation of Therapeutic Cells Using a Microfluidic Platform
Creators: name: Soucy, Nicholas
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2020
Subjects: Microfluidics
Encapsulation
Flow-Focusing
Therapeutic
Hydrogel
Microfabrication

description: Microencapsulation of stem cells in hydrogel for use in therapeutic applications has been shown to improve cell retention at the site of injuries due to their mechanical and immunoprotective properties. These microscale droplets (cocoons) can be produced at high throughputs within microfluidic channels. Currently, the ability for cells to egress hydrogel cocoons is under investigation. This egress can correlate with therapeutic efficacy, and so promoting or inhibiting the egress of cells can be a vital component of viable treatments. Previously, a second hydrogel layer was shown to reduce egress, but issues involving cell proliferation were unchanged. We propose a microfluidic process to encapsulate cells in two layers of thermoresponsive hydrogels, in which the inner core melts at physiological temperatures to form hollow cocoons that allow cells free motion inside the immunoprotective shell. We hypothesize that the open volume would increase cell viability and proliferation, without increasing cell egress due to the uninterrupted hydrogel shell. In this project the encapsulation of NIH 3T3 cells in hollow agarose cocoons was achieved. 3T3 cells were first encapsulated in thermoreversible gelatin which were then re-encapsulated in agarose through the use of a flow-focusing microfluidic channel with on-chip mixing of two inlet flows to produce hollow cocoons. The production of these cocoons showed the potential of high throughput, monodisperse samples with future investment. Preliminary investigation in the behavior of the encapsulated cells showed that the cells maintain high viability over the course of 48 hours. There are early indications that the hollow nature of correctly formed cocoons can limit cell egress, and may allow for proliferation in the cocoon.
Dusty plasma in active galactic nuclei
Creators: name: Czerny, Bożena
name: Zajaček, Michal
name: Naddaf, Mohammad-Hassan
name: Sniegowska, Marzena
name: Panda, Swayamtrupta
name: Różanska, Agata
name: Adhikari, Tek P.
name: Pandey, Ashwani
name: Jaiswal, Vikram Kumar
name: Karas, Vladimír
name: Borkar, Abhijeet
name: Martínez-Aldama, Mary Loli
name: Prince, Raj
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Since many years we know that dust in the form of the dusty-molecular torus is responsible for the obscuration in active galactic nuclei (AGN) at large viewing angles and thus for the classification of AGN. Recently, we gained some observational and theoretical insight into geometry of the region and the role of the dust in the dynamics of the outflow and failed winds. We will briefly touch on all these aspects, including our dust-based model (FRADO - Failed Radiatively Accelerated Dusty Outflow) of the formation of the Balmer lines in AGN.
description: Partially based on talk at 31st Symposium on the Physics of Ionized Gases in Belgrade, accepted for European Physical Journal D Topical Issue: "Physics of Ionized Gases and Spectroscopy of Isolated Complex Systems: Fundamentals and Applications"
Structural and functional imaging of tauopathies
Creators: name: Smith-Forrester, Jenna Rae
Publisher: name: University of British Columbia
Year: 2015

description: Repetitive head trauma is a known cause of tau protein accumulation and the leading cause of chronic traumatic encephalopathy (CTE). Currently, no robust method for in vivo detection of CTE exists and definitive diagnosis can only be made post-mortem. This thesis aimed to address two gaps in the literature surrounding head injury and tau accumulation. First, we sought to evaluate the effects of concussion on adolescent brain structure using mathematical modeling applied to diffusion tensor imaging (DTI). In our study, 12 adolescent athletes completed DTI in the sub-acute phase of recovery from concussion. The primary outcome measures included Complex Network Analysis metrics related to efficiency, nodal clustering, and fibre tract length. These measures were applied to diffusivity output (FA, MD, and number of tracts) in subnetworks of vulnerability, with specific focus on the Default Mode Network (DMN). Here we found microstructural changes in the DMN of concussed athletes with increased clustering and shorter path lengths, indicating increased local efficiency. A corresponding decrease in global efficiency and alterations in core hubs may underlie the clinical profile, suggesting concussion results in large-scale network disconnection. Longitudinal studies with network analysis may serve as a marker of collective injury and provide early detection of pathological structural organization. Second, we established the baseline measures of a novel positron emission tomography (PET) radioligand, ¹¹C-PBB3, which is specific for hyperphosphorylated tau protein. We collected data on healthy, elderly individuals (n = 8), and tested the tracer in a probable (n = 1) and severe (n = 1) case of Progressive Supranuclear Palsy (PSP), a known tauopathy. We found that tracer circulated in the venous sinuses in our healthy controls with little to no deposition in brain tissue. We also present preliminary findings of tracer accumulation in the basal ganglia and thalamus in the PSP cases. These results suggest ¹¹C-PBB3 is a viable tracer for use in other tauopathies, including CTE. Longitudinal studies with combined DTI and PET are necessary to elucidate the potentially synergistic interactions between damage to white matter tracts, tau accumulation, inflammation, and the initiation of processes leading to CTE and other tauopathies.
Equation of state for strange quark matter: Linking the Nambu--Jona-Lasinio model to perturbative QCD
Creators: name: Pinto, Marcus Benghi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Neutron star constraints and {\it ab initio} pQCD evaluations require the EoS representing cold quark matter to be stiff at intermediate baryonic densities and soft at high-$n_B$. Here, I suggest that the three flavor NJL model with a density dependent repulsive coupling, $G_V(μ)$, can generate an EoS which interpolates between these two regimes. Such an interpolation requires repulsion to start decreasing with the chemical potential just after chiral transition takes place. The conjecture behind this mechanism is that repulsion should be necessary only as long as the quark condensates, which dress the effective masses, have non-vanishing values. This assumption guarantees that an initially hard EoS suffers a conspicuous change of slope at ${\cal E} \simeq 0.7 \,{\rm GeV fm^{-3}}$ converging to the pQCD results at higher energy densities. Then, the speed of sound naturally reaches a non-conformal maximum at $n_B = 3.23 \, n_0 = 0.52 \, {\rm fm}^{-3}$ while the trace anomaly remains positive for all densities, in agreement with recent investigations. These non-trivial results {\it cannot} be simultaneously obtained when $G_V$ vanishes or has a fixed value. Therefore, the simple model proposed here is able to link the (non-perturbative) region of intermediate densities to the region where pQCD becomes reliable.
description: Matches version published in Phys. Rev. C 107, 045807 (2023)
Direct vs. indirect optical recombination in Ge films grown on Si substrates
Creators: name: Grzybowski, G.
name: Roucka, R.
name: Mathews, J.
name: Beeler, R. T
name: Kouvetakis, J.
name: Menéndez, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The optical emission spectra from Ge films on Si are markedly different from their bulk Ge counterparts. Whereas bulk Ge emission is dominated by the material's indirect gap, the photoluminescence signal from Ge films is mainly associated with its direct band gap. Using a new class of Ge-on-Si films grown by a recently introduced CVD approach, we study the direct and indirect photoluminescence from intrinsic and doped samples and we conclude that the origin of the discrepancy is the lack of self-absorption in thin Ge films combined with a deviation from quasi-equilibrium conditions in the conduction band. The latter is confirmed by a simple model suggesting that the deviation from quasi-equilibrium is caused by the much shorter recombination lifetime in the films relative to bulk Ge.
Long time averaged reflection force and homogenization of oscillating Neumann boundary conditions
Creators: name: Arisawa, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: This paper concerns with two issues. The first issue is the existence and the uniqueness of the ergodic type number $d$ which appears in the oblique boundary condition. The second issue is the application of the number for the study of homogenizations of oscillating Neumann boundary conditions.
Superposition as a logical glue
Creators: name: Asperti, Andrea
name: Tassi, Enrico
Publisher: name: arXiv
Year: 2011
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: The typical mathematical language systematically exploits notational and logical abuses whose resolution requires not just the knowledge of domain specific notation and conventions, but not trivial skills in the given mathematical discipline. A large part of this background knowledge is expressed in form of equalities and isomorphisms, allowing mathematicians to freely move between different incarnations of the same entity without even mentioning the transformation. Providing ITP-systems with similar capabilities seems to be a major way to improve their intelligence, and to ease the communication between the user and the machine. The present paper discusses our experience of integration of a superposition calculus within the Matita interactive prover, providing in particular a very flexible, "smart" application tactic, and a simple, innovative approach to automation.
description: In Proceedings TYPES 2009, arXiv:1103.3111
Non-Arrhenius relaxation of the Heisenberg model with dipolar and anisotropic interactions
Creators: name: Díaz-Méndez, Rogelio
name: Mulet, Roberto
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The dynamical properties of a 2D Heisenberg model with dipolar interactions and perpendicular anisotropy are studied using Monte Carlo simulations in two different ordered regions of the equilibrium phase diagram. We find a temperature defining a dynamical transition below which the relaxation suddenly slows down and the system aparts from the typical Arrhenius relaxation to a Vogel-Fulcher-Tamann law. This anomalous behavior is observed in the scaling of the magnetic relaxation and may eventually lead to a freezing of the system. Through the analysis of the domain structures we explain this behavior in terms of the domains dynamics. Moreover, we calculate the energy barriers distribution obtained from the data of the magnetic viscosity. Its shape supports our comprehension of both, the Vogel-Fulcher-Tamann dynamical slowing down and the freezing mechanism.
The approach to vortex reconnection
Creators: name: Tebbs, Richard
name: Youd, Anthony J.
name: Barenghi, Carlo F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We present numerical solutions of the Gross--Pitaevskii equation corresponding to reconnecting vortex lines. We determine the separation of vortices as a function of time during the approach to reconnection, and study the formation of pyramidal vortex structures. Results are compared with analytical work and numerical studies based on the vortex filament method.
description: 11 pages, 9 figures
Dynamic Model Specialization for Efficient Inference, Training and Supervision
Creators: name: Mullapudi, Ravi Teja
Publisher: name: Carnegie Mellon University
Year: 2022
Subjects: subject: 80104 Computer Vision
subject: FOS: Computer and information sciences

description: Recent supervised learning approaches focus on designing and building models that generalize to a wide range of scenarios. The key ingredients for building these general models are large scale datasets that capture a diverse set of scenarios and computational resources to train large models. This large scale supervised learning approach has well known scalability challenges namely: 1) accurate general models are computationally expensive for training and inference 2) collecting and labeling large datasets requires extensive human effort and 3) datasets need to be repeatedly curated due to shifts in the target distribution. In this thesis, we argue that in many cases creating a set of highly specialized models that span the domain of interest can reduce model inference, training, and supervision costs, compared to creating a single monolithic model that generalizes across the entire domain. Specifically, we exploit temporal specialization for building efficient video segmentation models. We show that continuously specializing a compact model to the content in a video stream enables accurate and efficient inference. We leverage specialization to visually similar categories for building efficient image classification architectures. Weshow that by specializing model features to discriminate between visually similar categories, one can improve inference efficiency by only computing the subsetof features necessary for classifying a specific image. We exploit specialization to individual categories for reducing human labeling effort in building models for rare categories. We show that models specialized for binary classification ofindividual rare categories reduce human e?ort in mining large unlabeled data collections for relevant examples. More broadly, we demonstrate that by dynamically specializing to a moment in time, to an input scene, or to a specificobject category, it is possible to train accurate models quickly, reduce inference costs, and significantly reduce the amount of supervision required for training.
Overlapping-gate architecture for silicon Hall bar MOSFET devices in the low electron density regime
Creators: name: van Beveren, Laurens H. Willems
name: Tan, Kuan Y.
name: Lai, Nai-Shyan
name: Dzurak, Andrew S.
name: Hamilton, Alex R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report the fabrication and study of Hall bar MOSFET devices in which an overlapping-gate architecture allows four-terminal measurements of low-density 2D electron systems, while maintaining a high density at the ohmic contacts. Comparison with devices made using a standard single gate show that measurements can be performed at much lower densities and higher channel resistances, despite a reduced peak mobility. We also observe a voltage threshold shift which we attribute to negative oxide charge, injected during electron-beam lithography processing.
description: 4 pages, 4 figures, submitted for Applied Physics Letters
Interpretation of the line spectrum of classical symbiotic stars in the scenario for their prototype Z And
Creators: name: Tomov, N. A.
name: Bisikalo, D. V.
name: Tomova, M. T.
name: Kilpio, E. Yu.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Results of the study of the symbiotic binary Z And during its recent active phase 2000 -- 2010 when it experienced a series of six optical outbursts are presented. High-resolution spectra obtained during the first and fourth outburst, which was the strongest one, have been analyzed. These data are compared with results of theoretical computations. The comparison provides information about the behaviour of the system during the entire active phase rather than during an individual outburst. In particular it was found fundamental difference between the first outburst, which opened the active phase, and the recurrent outbursts - namely, the presence of bipolar collimated optical outflow during some of the recurrent outbursts. A scenario that can explain all the spectroscopic phenomena observed during this active phase as well as previous active phases of Z And is proposed. The possibility to use this scenario for explanation of the line spectrum of other classical symbiotic stars during their active phases is motivated.
description: 10 pages, 10 figures; to be published in AIP Conf. Proc., School and Workshop on SPACE PLASMA PHYSICS, Kiten, Bulgaria; corrected typos