cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Higher-order interference and single-system postulates characterizing quantum theory
Creators: name: Barnum, Howard
name: Mueller, Markus P.
name: Ududec, Cozmin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We present a new characterization of quantum theory in terms of simple physical principles that is different from previous ones in two important respects: first, it only refers to properties of single systems without any assumptions on the composition of many systems; and second, it is closer to experiment by having absence of higher-order interference as a postulate, which is currently the subject of experimental investigation. We give three postulates -- no higher-order interference, classical decomposability of states, and strong symmetry -- and prove that the only non-classical operational probabilistic theories satisfying them are real, complex, and quaternionic quantum theory, together with 3-level octonionic quantum theory and ball state spaces of arbitrary dimension. Then we show that adding observability of energy as a fourth postulate yields complex quantum theory as the unique solution, relating the emergence of the complex numbers to the possibility of Hamiltonian dynamics. We also show that there may be interesting non-quantum theories satisfying only the first two of our postulates, which would allow for higher-order interference in experiments while still respecting the contextuality analogue of the local orthogonality principle.
description: 21 + 6 pages, 1 figure. v4: published version (includes several minor corrections)
title: Unexpected demand and its impact on hospital cost : the case of Greece
Creators: name: Boutsioli, Zoe
Publisher: name: University of Kent
Year: 2022

description: Public hospitals in Greece are part of a National Health System of providing health care services. This system was established in 1983 and since then it has been the subject of various criticisms, evaluations and modernizations in order to improve its cost efficiency. I put an emphasis on the role of unexpected demand for hospital services and its impact on hospital costs in a sample of ten public hospitals during the period 2001-2005. The analysis of the cost efficiency problems of the Greek public hospitals has serious implications for the allocation of scarce public funding and is very significant for both policy makers and hospital administrators. The main hypothesis to be tested is that unexpected demand has a positive impact on hospital cost. The measures of unexpected demand are given by applying a univariate ARMA model. Also, a multivariate model tested, but the ARMA results are superior. The empirical findings indicate that the Greek hospitals respond to unexpected demand by holding reserve capacity. If the cost function does not include unexpected demand, then hospitals will appear to be cost inefficient. If holding reserve capacity is an efficient response to demand uncertainty, then reimbursement and regulatory policies should be adjusted to account for such hospital cost structures. A number of policy issues were raised. First, there is a need for better data and accurate information. Second, health planners should consider restructuring the hospital capacity in order to fully take advantage of the economies of scale. My evidence shows that Greece needs smaller hospitals and dais might generate important savings. Also, better management of unexpected demand at the central level would lead to cost savings. Last, the identification of the best performing hospitals can be used as examples by other hospitals in order to reduce short run and long run cost inefficiencies.
Chelyabinsk dieci anni dopo
Creators: Redazione Esa
Publisher: name: Media Inaf
Year: 2023

Il 15 febbraio 2013, poco dopo l’alba di una soleggiata giornata invernale, un asteroide di circa 20 metri e 13mila tonnellate entrò nell’atmosfera sopra i Monti Urali, in Russia, a una velocità di oltre 18 km/s. È il più grande asteroide che abbia colpito la Terra in oltre un secolo. Nessuno l’aveva visto avvicinarsi. Cosa è cambiato da allora, in termini di difesa planetaria?
9,11,12,13,13a,14-Hexahydrodibenzo(f,h)pyrrollo(1,2-b)isochinoline durch Diels-Alder-Reaktion
Creators: name: Dannhardt, G.
name: Wiegrebe, Wolfgang
Publisher: name: Universität Regensburg
Year: 1977
Subjects: subject: 540 Chemie

description: Bei der Diels-Alder-Reaktion von Phenanthrochinodimethan mit methylsubstituierten Pyrrolinen bilden sich 9,11,12,13,13a, 14-Hexahydro-dibenzo[f, h]pyrrolo[l,2-b]isochinolin-Derivate, deren NMR-Spektren im Bereich der aliphatischen Protonen beschrieben werden. 2-Cyano-5,5- dimethyl-Al-pyrrolin wurde synthetisiert; es reagiert nicht im o. a. Sinne. The Diels-Alder reaction of phenanthroquinodimethane with methylpyrrolines leads to 9,11, 12,13, 13a, 14-hexahydrodibenzo(/, /i]pyrrolo[l,2-&] isoquinoline derivatives. The chemical shifts of the aliphatic protons in the NMR-spectra are discussed. 2-Cyano-5,5-dimethyl^1-pyrroline was synthesized; it failed to give a Diels-Alder product.
title: Enslaved under the elements of the cosmos
Creators: name: Clark, Ernest P
Publisher: name: University of St Andrews
Year: 2018

description: When Paul writes ‘we too were enslaved under the elements of the world’, he means that the elements that compose the cosmos also compose and compromise the flesh and enslave human persons through their bodies (Gal 4.3). This thesis demonstrates that early Jews used the phrase στοιχεῖα τοῦ κόσμου to refer to the material elements – earth, water, air, and fire – and not to elemental spirits or elementary principles. Greek medical tradition understood the material elements to mediate the stimuli (παθήματα) and desires of the body which enslave the soul, and it prescribed a variety of regimens (including νόμος) as παιδαγωγοί to guide a person to wholeness. In his philosophy according to the cosmic elements, Philo promotes the law of Moses – including circumcision and the calendar – as the effective way to be ‘redeemed from slavery’ to the flesh, to attain righteousness, and to live in harmony with the cosmos. Paul’s epistle to the Galatians opposes this sort of ‘redemptive nomism’. Paul accepts that weak στοιχεῖα compose the weak σάρξ and that they mediate sinful stimuli and desires that lead to the actions of the flesh. However, he denies that the law can make people alive or righteous. Instead, Paul prescribes crucifixion with Christ and new life with the Spirit as the final cure for sin’s infection of the flesh made of weak στοιχεῖα. Through faith, Christ will be formed in believers as the Spirit guides them away from the desires of the flesh and produces his fruit in their lives.
The tame automorphism group of an affine quadric threefold acting on a square complex
Creators: name: Bisi, Cinzia
name: Furter, Jean-Philippe
name: Lamy, Stéphane
Publisher: name: arXiv
Year: 2013
Subjects: subject: Group Theory (math.GR)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We study the group Tame(SL$_2$) of tame automorphisms of a smooth affine 3-dimensional quadric, which we can view as the underlying variety of SL(2,$\mathbb{C}$). We construct a square complex on which the group admits a natural cocompact action, and we prove that the complex is CAT(0) and hyperbolic. We propose two applications of this construction: We show that any finite subgroup in Tame(SL$_2$) is linearizable, and that Tame(SL$_2$) satisfies the Tits alternative.
description: Minor correction at the end of 6.2.1, and perfect figures!
Synthese und Hofmann-Abbau des 1-(Diphenyl-hydroxymethyl)-2,2-dimethyl-6,7-dimethoxy-1,2,3,4-tetrahydroisochinolinium-Ions
Creators: name: Wiegrebe, Wolfgang
name: Rohrbach-Munz, B.
name: Awe, W.
name: Kirk, O.
Publisher: name: Universität Regensburg
Year: 1975
Subjects: subject: 540 Chemie

description: Summary. The synthesis of the N-quaternary aminoalcohol 6 is described. Analogous to the aminoalcohols 1 and 2, 6 on treatment w i t h alkali undergoes fission of the substituent at C(l) as a carbonyl compound, with formation of a N, N-dimethyl-l,2,3,4-tetrahydroisoquinolinium ion, which is further degraded to the corresponding o-vinyl-benzylamine {Scheme 7). - As a by-product of a Bischler-Napieralski ring closure, we observed chlorination of an aromatic ring (yielding 19).
The Holographic Dual of AdS3 x S3 x S3 x S1
Creators: name: Tong, David
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct the two dimensional N=(0,4) gauge theory that lives on the world volume of D1-branes and intersecting D5-branes. We conjecture that this theory flows in the infra-red to a fixed point with large N=(4,4) superconformal symmetry. The central charge of the conformal field theory is shown to coincide with the holographic dual of string theory compactified on AdS3 x S3 x S3 x S1.
description: 23 pages. 1 Figure. v2 and v3: coupling corrected, typo fixed, references added. v4: version to appear in JHEP. v5: corrected number of chiral fermions at the intersection
Con Eht, dritti al cuore d’un quasar
Creators: Giuseppe Fiasconaro
Publisher: name: Media Inaf
Year: 2023

Gli scienziati dell’Event Horizon Telescope hanno osservato Nrao 530, un quasar che alberga al centro un buco nero supermassiccio con una massa stimata tra i trecento milioni e i due miliardi di masse solari, ottenendo un’istantanea della sua regione centrale che svela dettagli inediti della sorgente. Con il commento di Rocco Lico (Iaa-Csic/Inaf), tra gli autori dello studio
Se un po’ d’oscillazione allenta la tensione
Creators: Marco Malaspina
Publisher: name: Media Inaf
Year: 2023

Introducendo un’oscillazione primordiale nei primi istanti dopo il big bang – ovvero durante l’inflazione – nel classico modello Lambda-Cdm, tre discordanze rispetto alle attuali osservazioni cosmologiche si risolverebbero, o quanto meno si attenuerebbero. Fra queste anche la cosiddetta “tensione” su H0, la costante di Hubble. Ne parliamo con uno degli autori dello studio in uscita su Physical Review Letters che propone il nuovo modello, Fabio Finelli dell’Inaf di Bologna
Sub-quadratic Decoding of One-point Hermitian Codes
Creators: name: Nielsen, Johan S. R.
name: Beelen, Peter
Publisher: name: arXiv
Year: 2014
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We present the first two sub-quadratic complexity decoding algorithms for one-point Hermitian codes. The first is based on a fast realisation of the Guruswami-Sudan algorithm by using state-of-the-art algorithms from computer algebra for polynomial-ring matrix minimisation. The second is a Power decoding algorithm: an extension of classical key equation decoding which gives a probabilistic decoding algorithm up to the Sudan radius. We show how the resulting key equations can be solved by the same methods from computer algebra, yielding similar asymptotic complexities.
description: New version includes simulation results, improves some complexity results, as well as a number of reviewer corrections. 20 pages
Stereospezifische Synthese zweier 9,11,12,12,13a,14- Hexahydro-dibenzo(f,h)pyrrolo(1,2-b)isochinoline
Creators: name: Faber, L.
name: Wiegrebe, Wolfgang
Publisher: name: Universität Regensburg
Year: 1976
Subjects: subject: 540 Chemie

description: Summary. The stereospecific synthesis of (13aS)-( + )-2,3,6- and 3,4,6- trimethoxy-9,11,12,13,13a, 14-hexahydrodibenzo[/, A]pyrrolo[l, 2-&]isoquinoline is described. The 2,3,6-trimethoxy-compound proved to be the optical antipode of (— )-antofine, isolated from Cynanchum vincetoxicum L. Pers.
Charles and William Mayo
Creators: name: Cassidy, Gerald, 1869-1934
Publisher: name: Galter Health Science Library & Learning Center
Year: 2016

description: Oil on canvas portrait of Charles H. Mayo and William J. Mayo by artist Gerald Cassidy. B/w photo of framed portrait, measuring 221 cm H x 180 cm W x 8 cm D, housed in Feinberg School of Medicine, Northwestern University, Chicago, IL. Accompanying plaque, measuring 10.2 cm H x 15.2 cm W x 2.5 cm D, reads: Charles H. Mayo, MD., M.A., LL.D., Sc.D. Class of 1888, Northwestern University Medical School (standing) William J. Mayo, M.D., M.A., Sc.D., LL.D 1928, Sc.D., Northwestern University).
description: Portrait was commissioned by the Mayo brothers in 1925 and presented to Northwestern University in 1929. The portrait was formally dedicated in 1930 and was displayed in the Archibald Church Library at Northwestern University Medical School, now Galter Health Sciences Library. (source: article by Ron Sims, entitled, "Return of the Mayo Brothers' Portrait to Galter Library" in Library Notes #56, September 2009)
Gli occhi di Nustar sul Sole
Creators: Giuseppe Fiasconaro
Publisher: name: Media Inaf
Year: 2023

Il telescopio per raggi X della Nasa ha messo gli occhi sul Sole, catturando l'emissione X ad alta energia prodotta da alcuni nanobrillamenti, le eruzioni di materia e radiazioni che si pensa siano alla base del riscaldamento della corona solare, lo strato più esterno dell'atmosfera della nostra stella
Constraining chameleon models with cosmology
Creators: name: Lombriser, Lucas
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Chameleon fields may modify gravity on cluster scales while recovering general relativity locally. This article reviews signatures of chameleon modifications in the nonlinear cosmological structure, comparing different techniques to model them, summarising the current state of observational constraints, and concluding with an outlook on prospective constraints from future observations and applications of the analytic tools developed in the process to more general scalar-tensor theories. Particular focus is given to the Hu-Sawicki and designer models of f(R) gravity.
description: 24 pages, 5 figures, 1 table; invited review article; v2 matches published version
Fra Marte e il Cervino, la cometa verde Ztf
Creators: Valentina Guglielmo
Publisher: name: Media Inaf
Year: 2023

La Apod del giorno della Nasa è contesa fra Marte e il Cervino. Scattata dalla località di Zermatt dall’italiano Donato Lioce, l’immagine astronomica del giorno è una composizione che ha richiesto un’intera nottata per essere realizzata
The MSPSR$π$ catalogue: VLBA astrometry of 18 millisecond pulsars
Creators: name: Ding, H.
name: Deller, A. T.
name: Stappers, B. W.
name: Lazio, T. J. W.
name: Kaplan, D.
name: Chatterjee, S.
name: Brisken, W.
name: Cordes, J.
name: Freire, P. C. C.
name: Fonseca, E.
name: Stairs, I.
name: Guillemot, L.
name: Lyne, A.
name: Cognard, I.
name: Reardon, D. J.
name: Theureau, G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: With unparalleled rotational stability, millisecond pulsars (MSPs) serve as ideal laboratories for numerous astrophysical studies, many of which require precise knowledge of the distance and/or velocity of the MSP. Here, we present the astrometric results for 18 MSPs of the "MSPSR$π$" project focusing exclusively on astrometry of MSPs, which includes the re-analysis of 3 previously published sources. On top of a standardized data reduction protocol, more complex strategies (i.e., normal and inverse-referenced 1D interpolation) were employed where possible to further improve astrometric precision. We derived astrometric parameters using sterne, a new Bayesian astrometry inference package that allows the incorporation of prior information based on pulsar timing where applicable. We measured significant ($>3\,σ$) parallax-based distances for 15 MSPs, including $0.81\pm0.02\,$kpc for PSR J1518+4904 -- the most significant model-independent distance ever measured for a double neutron star system. For each MSP with a well-constrained distance, we estimated its transverse space velocity and radial acceleration. Among the estimated radial accelerations, the updated ones of PSR J1012+5307 and PSR J1738+0333 impose new constraints on dipole gravitational radiation and the time derivative of Newton's gravitational constant. Additionally, significant angular broadening was detected for PSR J1643-1224, which offers an independent check of the postulated association between the HII region Sh 2-27 and the main scattering screen of PSR J1643-1224. Finally, the upper limit of the death line of $γ$-ray-emitting pulsars is refined with the new radial acceleration of the hitherto least energetic $γ$-ray pulsar PSR J1730-2304.
description: 23 pages, 6 figures, 10 tables, published in MNRAS
Breve storia dell’asteroide 2023 CX1
Creators: Albino Carbognani
Publisher: name: Media Inaf
Year: 2023

Nelle prime ore del mattino del 13 febbraio 2023, un piccolo asteroide di circa un metro di diametro è caduto in atmosfera frammentandosi nel canale della Manica davanti alle coste della Normandia. Casi come questi sono sempre più frequenti e, anche se non costituiscono un pericolo per la Terra, sono delle avventure che meritano di essere raccontate
Simplified Dark Matter Models for the Galactic Center Gamma-Ray Excess
Creators: name: Berlin, Asher
name: Hooper, Dan
name: McDermott, Samuel D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Motivated by the gamma-ray excess observed from the region surrounding the Galactic Center, we explore particle dark matter models that could potentially account for the spectrum and normalization of this signal. Taking a model-independent approach, we consider an exhaustive list of tree-level diagrams for dark matter annihilation, and determine which could account for the observed gamma-ray emission while simultaneously predicting a thermal relic abundance equal to the measured cosmological dark matter density. We identify a wide variety of models that can meet these criteria without conflicting with existing constraints from direct detection experiments or the Large Hadron Collider (LHC). The prospects for detection in near future dark matter experiments and/or the upcoming 14 TeV LHC appear quite promising.
description: 36 pages (20 are appendices); v4: some minor corrections in formulas in appendices, conclusions unchanged
Our History
Creators: name: Physicians And Surgeons Hospital
Publisher: name: Unknown
Year: 1978
Subjects: Coffey, Robert Calvin, 1869-1933
Physicians
Surgeons
Hospitals, General
Surgical Procedures, Operative
Oregon--Portland

description: This booklet briefly covers the over 70-year history of the Physicians and Surgeons Hospital, from its beginning as a private institution to a nonprofit hospital and healthcare system, noting the great advancements in medicine during this timeframe. The culture of hospitals in general shifted as well, which before then had primarily reserved care in these facilities to the poor, with doctors treating wealthier patients in their own homes. The hospital was purchased in the 1940s by physicians and surgeons themselves–which was a rarity–and it became a community-driven hospital, contributing to the expansion of services and innovations of care, including supporting industrial workers and being one of the first institutions whose team performed open heart surgery. Additionally, there was an alliance between two other hospitals, going on to create the Health Network of America in 1982.
The real and apparent convergence of N-body simulations of the dark matter structures: is the Navarro-Frenk-White profile real?
Creators: name: Baushev, Anton N.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We consider the reasons why a cuspy NFW-like profile persistently occurs in N-body simulations, in contradiction to some astronomical observations. The routine method of testing the convergence of N-body simulations (in particular, the negligibility of two-body scattering effect) is to find the conditions under which the shape of the formed structures is insensitive to numerical parameters. The results obtained with this approach suggest a surprisingly minor role of the particle collisions: the central density profile remains untouched and close to NFW, even if the simulation time significantly exceeds the collisional relaxation time $τ_r$. We analyze the test body distribution in the halo center with help of the Fokker-Planck equation. It turns out that the Fokker-Planck diffusion transforms any reasonable initial distribution into NFW-like profile $ρ\propto r^{-1}$ in a time shorter than $τ_r$. On the contrary, profile $ρ\propto r^{-1}$ should survive much longer, being a sort of attractor: the Fokker-Planck diffusion is self-compensated in this case. Thus the test body scattering may create a stable NFW-like pseudosolution that can be mixed up with the real convergence. This fact might help to eliminate the well-known 'cusp vs. core' problem.
description: 7 pages, 1 figure
Substrate texture affects female cricket walking response to male calling song
Creators: name: Hedwig, Berthold
name: Sarmiento-Ponce, Edith
name: Sutcliffe, Michael
Publisher: name: Apollo - University of Cambridge Repository
Year: 2018
Subjects: ground-living insects, insect walking, tarsal claws, biomechanics, depth profile, contact force measurements

description: Field crickets are extensively used as a model organism to study female phonotactic walking behaviour, i.e. their attraction to the male calling song. Laboratory-based phonotaxis experiments generally rely on arena or trackball-based settings; however, no attention has been paid to the effect of substrate texture on the response. Here, we tested phonotaxis in female Gryllus bimaculatus, walking on trackballs machined from methyl-methacrylate foam with different cell sizes. Surface height variations of the trackballs, due to the cellular composition of the material, were measured with profilometry and characterized as smooth, medium or rough, with roughness amplitudes of 7.3, 16 and 180 µm. Female phonotaxis was best on a rough and medium trackball surface, a smooth surface resulted in a significant lower phonotactic response. Claws of the cricket foot were crucial for effective walking. Females insert their claws into the surface pores to allow mechanical interlocking with the substrate texture and a high degree of attachment, which cannot be established on smooth surfaces. These findings provide insight to the biomechanical basis of insect walking and may inform behavioural studies that the surface texture on which walking insects are tested is crucial for the resulting behavioural response.
description: This study is supported by a Mexican CONACyT Cambridge Trust Scholarship to E.J.S.P., Newnham College, the Royal Entomological Society, the Philosophical Society and the Department of Zoology. The equipment used was funded by a BBSRC grant to B.H.
Topological Bloch Bands in Graphene Superlattices
Creators: name: Song, Justin C. W.
name: Samutpraphoot, Polnop
name: Levitov, Leonid S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We outline an approach to endow a plain vanilla material with topological properties by creating topological bands in stacks of manifestly nontopological atomically thin materials. The approach is illustrated with a model system comprised of graphene stacked atop hexagonal-boron-nitride. In this case, the Berry curvature of the electron Bloch bands is highly sensitive to the stacking configuration. As a result, electron topology can be controlled by crystal axes alignment, granting a practical route to designer topological materials. Berry curvature manifests itself in transport via the valley Hall effect and long-range chargeless valley currents. The non-local electrical response mediated by such currents provides diagnostics for band topology.
Coordinate-space singularities of massless gauge theories
Creators: name: Erdoğan, Ozan
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The structure of singularities in perturbative massless gauge theories is investigated in coordinate space. The pinch singularities in coordinate-space integrals occur at configurations of vertices which have a direct interpretation in terms of physical scattering of particles in real space-time in the same way as for the loop momenta in the case of momentum-space singularities. In the analysis of vertex functions in coordinate space, the well-known factorization into hard, soft, and jet functions is found. By power-counting arguments, it is found that coordinate-space integrals of vertex functions have logarithmic divergences at worst.
description: 42 pages, 6 figures. v2: Figure 6 corrected, matches published version
Introduction: Translators and Translations of Early Modern Science
Creators: name: Fransen, Sietske
Publisher: name: Apollo - University of Cambridge Repository
Year: 2017

description: In the introduction to the German translation of Jan Baptista van Helmont’s (1579–1644) originally Latin Ortus medicinae [The Rise of Medicine], the translator Christian Knorr von Rosenroth (1636–1689) explains that his chief aim was to make the text understandable to the reader. To accomplish that level of comprehensibility he had to make some choices:
Il “Bardo” di Google toppa all’esordio su Jwst
Creators: Rossella Spiga
Publisher: name: Media Inaf
Year: 2023

Lo strumento di intelligenza artificiale Bard di Google si tradisce al debutto sul test di astrofisica. L’inciampo è avvenuto sulla prima foto di un pianeta extrasolare scattata da James Webb, presentata erroneamente come la prima immagine diretta di un esopianeta in assoluto. Immediata la reazione dei mercati: le quotazioni del colosso di Mountain View hanno perso circa 100 miliardi di dollari in un giorno
Bagliori autunnali sugli anelli di Saturno
Creators: Marco Malaspina
Publisher: name: Media Inaf
Year: 2023

Nelle ultime immagini di Saturno acquisite dal telescopio spaziale Hubble della Nasa si intravedono i primi segni dell’inizio della cosiddetta “spoke season”, la stagione della comparsa di enigmatiche chiazze sugli anelli in concomitanza con l’equinozio del pianeta. La causa del fenomeno, così come la sua variabilità stagionale, non è ancora stata del tutto compresa
A. hexahedron element formulation with a new multi-resolution analysis
Creators: name: Xia, Yi Ming
name: Chen, Shao Lin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: A multi-resolution hexahedron element and method is presented with a new multi-resolution analysis (MRA) framework. The MRA framework is formulated out of a mutually nesting displacement subspace sequence, whose basis functions are constructed of scaling and shifting on the element domain of a basic node shape function. The basic node shape function is constructed from extending to other seven quadrants around a specific node of a node isoparametric shape function. The MRA endows the proposed element with the resolution level (RL) to adjust the element node number, thus modulating structural analysis accuracy accordingly. As a result, the traditional 8-node hexahedron element and method is a mono-resolution one and also a special case of the proposed element and method. The accuracy of a structural analysis is actually determined by the RL, not by the mesh. The simplicity and clarity of shape function construction with the Kronecker delta property and the rational MRA enable the proposed element method to be more rational, easier and efficient in its implementation than the conventional mono-resolution solid element method or other MRA methods. The multi-resolution hexahedron element is more adapted to dealing with the accurate computation of structural problems.
description: 15pages, 10 figures. arXiv admin note: substantial text overlap with arXiv:1404.1165
Robust and computationally feasible community detection in the presence of arbitrary outlier nodes
Creators: name: Cai, T. Tony
name: Li, Xiaodong
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistics Theory (math.ST)
subject: Information Theory (cs.IT)
subject: Optimization and Control (math.OC)
subject: Machine Learning (stat.ML)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: Community detection, which aims to cluster $N$ nodes in a given graph into $r$ distinct groups based on the observed undirected edges, is an important problem in network data analysis. In this paper, the popular stochastic block model (SBM) is extended to the generalized stochastic block model (GSBM) that allows for adversarial outlier nodes, which are connected with the other nodes in the graph in an arbitrary way. Under this model, we introduce a procedure using convex optimization followed by $k$-means algorithm with $k=r$. Both theoretical and numerical properties of the method are analyzed. A theoretical guarantee is given for the procedure to accurately detect the communities with small misclassification rate under the setting where the number of clusters can grow with $N$. This theoretical result admits to the best-known result in the literature of computationally feasible community detection in SBM without outliers. Numerical results show that our method is both computationally fast and robust to different kinds of outliers, while some popular computationally fast community detection algorithms, such as spectral clustering applied to adjacency matrices or graph Laplacians, may fail to retrieve the major clusters due to a small portion of outliers. We apply a slight modification of our method to a political blogs data set, showing that our method is competent in practice and comparable to existing computationally feasible methods in the literature. To the best of the authors' knowledge, our result is the first in the literature in terms of clustering communities with fast growing numbers under the GSBM where a portion of arbitrary outlier nodes exist.
description: Published at http://dx.doi.org/10.1214/14-AOS1290 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Microbial mutualism at a distance: the role of geometry in diffusive exchanges
Creators: name: Peaudecerf, Francois
name: Bunbury, Frederick
name: Bhardwaj, V
name: Bees, Martin A
name: Smith, Alison Gail
name: Goldstein, Raymond Ethan
name: Croze, Ottavio Alfred
Publisher: name: Apollo - University of Cambridge Repository
Year: 2018

description: The exchange of diffusive metabolites is known to control the spatial patterns formed by microbial populations, as revealed by recent studies in the laboratory. However, the matrices used, such as agarose pads, lack the structured geometry of many natural microbial habitats, including in the soil or on the surfaces of plants or animals. Here we address the important question of how such geometry may control diffusive exchanges and microbial interaction. We model mathematically mutualistic interactions within a minimal unit of structure: two growing reservoirs linked by a diffusive channel through which metabolites are exchanged. The model is applied to study a synthetic mutualism, experimentally parametrized on a model algal-bacterial co-culture. Analytical and numerical solutions of the model predict conditions for the successful establishment of remote mutualisms, and how this depends, often counterintuitively, on diffusion geometry. We connect our findings to understanding complex behavior in synthetic and naturally occurring microbial communities.
description: Gates Cambridge Trust The Winton Foundation for the Physics of Sustainability The Royal Society The Schlumberger Chair Fund
Localised auxin peaks in concentration-based transport models of the shoot apical meristem
Creators: name: Draelants, Delphine
name: Avitabile, Daniele
name: Vanroose, Wim
Publisher: name: arXiv
Year: 2014
Subjects: subject: Dynamical Systems (math.DS)
subject: Pattern Formation and Solitons (nlin.PS)
subject: Tissues and Organs (q-bio.TO)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: We study the formation of auxin peaks in a generic class of concentration-based auxin transport models, posed on static plant tissues. Using standard asymptotic analysis we prove that, on bounded domains, auxin peaks are not formed via a Turing instability in the active transport parameter, but via simple corrections to the homogeneous steady state. When the active transport is small, the geometry of the tissue encodes the peaks' amplitude and location: peaks arise where cells have fewer neighbours, that is, at the boundary of the domain. We test our theory and perform numerical bifurcation analysis on two models which are known to generate auxin patterns for biologically plausible parameter values. In the same parameter regimes, we find that realistic tissues are capable of generating a multitude of stationary patterns, with a variable number of auxin peaks, that can be selected by different initial conditions or by quasi-static changes in the active transport parameter. The competition between active transport and production rate determines whether peaks remain localised or cover the entire domain. We relate the occurrence of localised patterns to a snaking bifurcation structure, which is known to arise in a wide variety of nonlinear media but has not yet been reported in plant models.
Developing English listening skills by using Audio-Lingual Method Techniques in Listening for Specific Purposes Course: Case Study, Ban Non-Wat Archaeological Site
Creators: name: Thananya Viriyapanyanont
Publisher: name: DR.KEN Institute of Academic Development and Promotion
Year: 2022
Subjects: Listening Skills
Audio-Lingual Method
Specific Purposes Course

description: International Journal of Sociologies and Anthropologies Science Reviews, 2, 6, 69-78
All’ombra della polvere lunare
Creators: Federico Di Giacomo
Publisher: name: Media Inaf
Year: 2023

Polvere “astronomica” come parasole per ridurre le radiazioni solari mitigando così gli effetti del  cambiamento climatico. È questo lo scenario descritto in uno studio appena pubblicato sulla rivista "Plos Climate" che descrive le diverse proprietà e le quantità delle particelle di polvere cosmica necessarie per ombreggiare adeguatamente la Terra e abbassare la temperatura del pianeta. Ma sarebbero “astronomici” anche i costi
Inflatonic baryogenesis with large tensor mode
Creators: name: Takeda, Naoyuki
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We consider the complex inflaton field with a CP asymmetric term for its potential. This CP asymmetric term produces the global charge of the inflaton after inflation. With the assignment of the baryon number to the inflaton, the baryon asymmetry of the universe is produced by inflaton's decay. In addition to this, the $U(1)$ breaking term modulates the curvature of the inflaton radial direction depending on its phase, which affects the tensor to scalar ratio. In this paper, we have studied the relation between the baryon asymmetry and the tensor to scalar ratio, then verified that the future CMB observation could test this baryogenesis scenario with large tensor mode.
description: 11 pages, 3 figures
Anello di detriti attorno al pianeta nano Quaoar
Creators: Ufficio stampa Inaf
Publisher: name: Media Inaf
Year: 2023

L’anello che circonda il corpo transnettuniano si trova oltre il limite di Roche il che è particolarmente interessante: questo limite determina la distanza oltre la quale qualsiasi oggetto celeste in avvicinamento al pianeta verrebbe fatto a pezzi. Lo studio su Nature
Kink-antikink collisions for twin models
Creators: name: Gomes, A. R.
name: Menezes, R.
name: Nobrega, K. Z.
name: Simas, F. C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this work we consider kink-antikink collisions for some classes of $(1,1)$-dimensional nonlinear models. We are particularly interested to investigate in which aspect the presence of a general kinetic content in the Lagrangian could be revealed in a collision process. We consider a particular class of models known as twin theories, where different models lead to same solutions for the equations of motion and same energy density profile. The theories can be distinguished in the level of linear stability of defect structure. We study a class of k-defect theories depending on a parameter $M$ which is the twin theory of the usual $ϕ^4$ theory with standard dynamics. For $M\to\infty$ both models are characterized by the same potential. In the regime $1/M^2<<1$, we obtain analytically the spectrum of excitations around the kink solution. It is shown that with the increasing on the parameter $1/M^2$: i) the gap between the zero-mode and the first-excited mode increases and ii) the tendency of one-bounce collision between kink-antikink increases. We numerically investigate kink-antikink scattering, looking for the influence of the parameter changing for the thickness and number of two-bounce windows, and confronting the results with our analytical findings.
description: 20 pages, 17 figures. Includes more numerical results and matches version published in Phys. Rev. D
Nana bianca solitaria sulla bilancia di Einstein
Creators: Valentina Guglielmo
Publisher: name: Media Inaf
Year: 2023

Si chiama microlensing gravitazionale ed è un effetto della relatività generale. Un effetto infinitesimale se riferito a stelle lontane e diverse dal Sole, ma già impiegato ben due volte per misurare la massa di una nana bianca. Oggi, per la prima volta, per misurare una nana bianca isolata. Tutti i dettagli su Mnras
Ferromagnetic SrRuO3 thin-film deposition on a spin-triplet superconductor Sr2RuO4 with highly conducting interface
Creators: name: Anwar, M. S.
name: Shin, Yeong Jae
name: Lee, Seung Ran
name: Kang, Sung Jin
name: Sugimoto, Yuske
name: Yonezawa, Shingo
name: Noh, Tae Won
name: Maeno, Yoshiteru
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Ferromagnetic SrRuO3 thin films are deposited on the ab-surface of single crystals of the spin-triplet superconductor Sr2RuO4 as substrates using pulsed laser deposition. The films are under a severe in-plane compressive strain. Nevertheless, the films exhibit ferromagnetic order with the easy axis along the c-direction below the Curie temperature of 158 K. The electrical transport reveals that the SrRuO3/Sr2RuO4 interface is highly conducting, in contrast with the interface between other normal-metals and the ab-surface of Sr2RuO4. Our results will stimulate the investigations on proximity effects between a ferromagnet and a spin-triplet superconductor.
Alla scoperta della galassia invisibile
Creators: Redazione Sissa
Publisher: name: Media Inaf
Year: 2023

Un oggetto misterioso e lontanissimo che si nasconde anche alle strumentazioni più avanzate in un universo vecchio “appena” due miliardi di anni dopo il Big Bang. Le sue caratteristiche sono ora descritte da un’equipe della Sissa in uno studio appena pubblicato su The Astrophysical Journal
Reactivity of water vapor in an atmospheric argon flowing post-discharge plasma torch
Creators: name: DUFOUR, Thierry
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 510602
subject: Plasma physics; fusion plasmas; electrical discharges

description: The reactivity of water vapor introduced in the flowing post-discharge of an RF atmospheric plasma torch is investigated through electrical characterization, optical emission spectroscopy and mass spectrometry measurements. Due to the technical features of the plasma torch, the post-discharge can be considered as divided into two regions: an inner region (inside the plasma torch device) where the water vapor is injected and an outer region which directly interacts with the ambient air. The main reactions induced by the injection of water vapor are identified as well as those indicative of the influence of the ambient air. Plausible pathways allowing the production of H, OH, O radicals and H2O2 are discussed as well as reactions potentially responsible for inhomogeneities and for a low DC current measured in the flowing post-discharge.
Template-Assisted Hydrothermal Growth of Aligned Zinc Oxide Nanowires for Piezoelectric Energy Harvesting Applications.
Creators: name: Ou, Canlin
name: Sanchez-Jimenez, PE
name: Datta, Anuja
name: Boughey, Chess
name: Whiter, RA
name: Sahonta, Lata
name: Kar-Narayan, Sohini
Publisher: name: Apollo - University of Cambridge Repository
Year: 2016
Subjects: ZnO nanowires
energy harvesting
hydrothermal synthesis
nanogenerators
piezoelectric effect

description: A flexible and robust piezoelectric nanogenerator (NG) based on a polymer-ceramic nanocomposite structure has been successfully fabricated via a cost-effective and scalable template-assisted hydrothermal synthesis method. Vertically aligned arrays of dense and uniform zinc oxide (ZnO) nanowires (NWs) with high aspect ratio (diameter ∼250 nm, length ∼12 μm) were grown within nanoporous polycarbonate (PC) templates. The energy conversion efficiency was found to be ∼4.2%, which is comparable to previously reported values for ZnO NWs. The resulting NG is found to have excellent fatigue performance, being relatively immune to detrimental environmental factors and mechanical failure, as the constituent ZnO NWs remain embedded and protected inside the polymer matrix.
description: The authors thank Yeonsik Choi for discussions and experimental support. S.K.-N., C.O., and A.D. are grateful for financial support from the European Research Council through an ERC Starting Grant (Grant no. ERC-2014-STG-639526, NANOGEN). F.L.B. and R.A.W. thank the EPSRC Cambridge NanoDTC, EP/G037221/1, for studentship funding. P.S.J. acknowledges the support of TEP-1900 and Talentia Postdoc Program, cofunded by the European Union’s Seventh Framework Program, Marie Skłodowska-Curie actions (COFUND Grant Agreement 267226) and the Ministry of Economy, Innovation, Science and Employment of the Junta de Andalucía. S-L.S acknowledges support through the EPSRC grant EP/M010589/1
The Osculating cone to special Brill-Noether Loci
Creators: name: Hoff, Michael
name: Mayer, Ulrike
Publisher: name: arXiv
Year: 2014
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14D10 (Primary), 14H51 (Secondary)

description: In this paper, we describe the osculating cone to Brill-Noether loci $W^{0}_{d}(C)$ at smooth isolated points of $W^{1}_{d}(C)$ for a smooth canonically embedded curve $C$ of even genus $g=2(d-1)$. In particular, we show that the canonical curve $C$ is a component of the osculating cone. The proof is based on techniques introduced by George Kempf in 1986.
description: 18 pages, v3: to appear in Collectanea Mathematica
Lavorare all’Esa come Young graduate trainee
Creators: Valentina Guglielmo
Publisher: name: Media Inaf
Year: 2023

È aperto il bando 2023 del programma Young graduate trainee (Ygt) dell’Agenzia spaziale europea, che offre più di cento posizioni per giovani laureandi o laureati, in una delle sedi dell’Esa fra Olanda, Francia e Germania. Le possibilità sono diverse: ce n’è per astrofisici, ingegneri di ogni tipo e anche comunicatori. Ne parliamo con chi Ygt lo è stato, l’ingegnere aerospaziale Antonio Gabriele, oggi all’Esa come System engineering and operations manager
Nested Term Graphs (Work In Progress)
Creators: name: Grabmayer, Clemens
name: van Oostrom, Vincent
Publisher: name: arXiv
Year: 2014
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We report on work in progress on 'nested term graphs' for formalizing higher-order terms (e.g. finite or infinite lambda-terms), including those expressing recursion (e.g. terms in the lambda-calculus with letrec). The idea is to represent the nested scope structure of a higher-order term by a nested structure of term graphs. Based on a signature that is partitioned into atomic and nested function symbols, we define nested term graphs both in a functional representation, as tree-like recursive graph specifications that associate nested symbols with usual term graphs, and in a structural representation, as enriched term graph structures. These definitions induce corresponding notions of bisimulation between nested term graphs. Our main result states that nested term graphs can be implemented faithfully by first-order term graphs. keywords: higher-order term graphs, context-free grammars, cyclic lambda-terms, higher-order rewrite systems
description: In Proceedings TERMGRAPH 2014, arXiv:1505.06818
Self-Dual Chiral Boson: Augmented Superfield Approach
Creators: name: Shukla, D.
name: Bhanja, T.
name: Malik, R. P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We exploit the standard tools and techniques of the augmented version of Bonora-Tonin (BT) superfield formalism to derive the off-shell nilpotent and absolutely anticommuting (anti-)BRST and (anti-)co-BRST symmetry transformations for the Becchi-Rouet-Stora-Tyutin (BRST) invariant Lagrangian density of a self-dual bosonic system. In the derivation of the full set of the above transformations, we invoke the (dual-)horizontality conditions, (anti-)BRST and (anti-)co-BRST invariant restrictions on the superfields that are defined on the (2, 2)-dimensional supermanifold. The latter is parameterized by the bosonic variable x^μ\,(μ= 0,\, 1) and a pair of Grassmanian variables θand \barθ(with θ^2 = \barθ^2 = 0 and θ\barθ+ \barθθ= 0). The dynamics of this system is such that, instead of the full (2, 2) dimensional superspace coordinates (x^μ, θ, \barθ), we require only the specific (1, 2)-dimensional super-subspace variables (t, θ, \barθ) for its description. This is a novel observation in the context of superfield approach to BRST formalism. The application of the dual-horizontality condition, in the derivation of a set of proper (anti-)co-BRST symmetries, is also one of the new ingredients of our present endeavor where we have exploited the augmented version of superfield formalism which is geometrically very intuitive.
description: LaTeX file, 27 pages, minor modifications, Journal reference is given
Asteroide da duecento metri per Webb
Creators: Giuseppe Fiasconaro
Publisher: name: Media Inaf
Year: 2023

Si trova a oltre cento milioni di km di distanza ed è grande come il Colosseo: sono i connotati del primo asteroide scoperto da Jwst. È il più piccolo oggetto celeste osservato fino ad oggi dal telescopio placcato oro. Ma le regole dell'Unione astronomica internazionale non consentiranno di definirlo come “ufficialmente scoperto” da Jwst, spiega a Media Inaf uno degli autori dello studio, Marco Micheli, dell’Esa
Stelle d’altre galassie, 13 miliardi d’anni fa
Creators: Marco Malaspina
Publisher: name: Media Inaf
Year: 2023

Grazie a uno specchio eccezionale – quello del telescopio spaziale James Webb – e a una lente naturale altrettanto straordinaria – l’ammasso di galassie Smacs 0723, un team d’astronomi dell’Università di Stoccolma è riuscito a distinguere addensamenti di stelle in formazione in galassie risalenti a quando l’universo aveva appena 680 milioni di anni