cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Intraseasonal Variability in an Aquaplanet General Circulation Model
Creators: name: Maloney, Eric D.
name: Sobel, Adam H.
name: Hannah, Walter M.
Publisher: name: Columbia University
Year: 2010
Subjects: Ocean circulation--Models
Precipitation (Meteorology)
Heat flux
Atmospheric physics
Madden-Julian oscillation

description: An aquaplanet atmospheric general circulation model simulation with a robust intraseasonal oscillation is analyzed. The SST boundary condition resembles the observed December‐April average with continents omitted, although with the meridional SST gradient reduced to be one‐quarter of that observed poleward of 10° latitude. Slow, regular eastward propagation at 5 m s−1 in winds and precipitation with amplitude greater than that in the observed MJO is clearly identified in unfiltered fields. Local precipitation rate is a strongly non‐linear and increasing function of column precipitable water, as in observations. The model intraseasonal oscillation resembles a moisture mode that is destabilized by wind‐evaporation feedback, and that propagates eastward through advection of anomalous humidity by the sum of perturbation winds and mean westerly flow. A series of sensitivity experiments are conducted to test hypothesized mechanisms. A mechanism denial experiment in which intraseasonal latent heat flux variability is removed largely eliminates intraseasonal wind and precipitation variability. Reducing the lower‐troposphere westerly flow in the warm pool by reducing the zonal SST gradient slows eastward propagation, supporting the importance of horizontal advection by the low‐level wind to eastward propagation. A zonally symmetric SST basic state produces weak and unrealistic intraseasonal variability between 30 and 90 day timescales, indicating the importance of mean low‐level westerly winds and hence a realistic phase relationship between precipitation and surface flux anomalies for producing realistic tropical intraseasonal variability.
Synthesis of substituted hydantoins in low melting mixtures
Creators: name: Gore, Sangram
name: Chinthapally, Kiran
name: Baskaran, Sundarababu
name: König, Burkhard
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: Hydantoin
subject: 540 Chemie

description: A novel domino synthesis of 1,3,5-trisubstituted hydantoin derivatives has been developed in low melting l-(+)-tartaric acid-DMU melt mixtures. The functionalized hydantoins are obtained in good yields from β,γ-unsaturated ketoacids and urea under environmentally benign and simple reaction conditions.
Final report on alternative tape usage (D4.4)
Creators: name: Masey, Neil
name: Jones, Matthew
name: Lawrence, Bryan
Publisher: name: Zenodo
Year: 2019

description: Storage systems at data centres are becoming increasingly heterogeneous, with the proliferation of new storage technology, often coexisting with older, more established technology.  This can lead to a number of problems for the users of these data centres.  Firstly, there can be a number of user interfaces and different programs available to access the storage systems, leading to user confusion and requiring a large commitment to training.  Secondly, the time for writing or reading data from these storage systems may be very disparate between the different systems.  Thirdly, a system may block until a user operation is executed (synchronous) or it may execute the operation in the backend (asynchronous). This can cause inconsistencies leading to user errors, such as dropping a connection on an initiated synchronous transfer may lead to abort of the operation.

To counteract these problems, we have developed a multi-tiered storage library which provides a single API to users. Regardless of the available storage system and behaviour, it allows to move data, to query the data that is stored on those systems, and to retrieve the data.  These interactions are carried out using a single user interface, which is a command line tool to be used interactively, and a HTTP API to be used programmatically.  The command line tool essentially provides a wrapper for calls to the HTTP API.
description: ESiWACE has received funding from the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No 675191
Single‐layer axisymmetric model for a Hadley circulation with parameterized eddy momentum forcing
Creators: name: Sobel, Adam H.
name: Schneider, Tapio
Publisher: name: Columbia University
Year: 2009
Subjects: Atmospheric circulation--Models
Eddies
Eddy flux
Atmospheric models
Climatology

description: An axisymmetric single‐layer model is used to study interactions of the Hadley circulation with extratropical eddies. Eddy momentum fluxes are parameterized using a simple closure motivated by calculations with an idealized dry general circulation model (GCM). Calculations are performed in which the heating is parameterized as Newtonian relaxation of temperatures toward a prescribed radiative‐convective equilibrium (RCE) state. The latitude at which the maximum RCE temperature occurs is varied to represent seasonal variations. In the axisymmetric model, as in the GCM, qualitative changes in the zonal momentum budget occur as the RCE temperature maximum moves away from the equator past a threshold latitude. For RCE temperature maxima closer to the equator, eddy momentum fluxes play a dominant role in the zonal momentum budget, nonlinearity is weak, and the meridional circulation is a weak function of the degree of asymmetry about the equator. For RCE temperature maxima sufficiently far from the equator, the zonal momentum budget becomes more nonlinear, angular momentum is more nearly conserved, and the circulation is a stronger function of the degree of asymmetry about the equator. Since the axisymmetric model can capture this behavior while being much simpler than the GCM, it may be a useful step towards a more comprehensive theory of the zonal‐mean general circulation.
Finite element methods for director fields on flexible surfaces
Creators: name: Bartels, Sören
name: Dolzmann, Georg
name: Nochetto, Ricardo H.
name: Raisch, Alexander
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: Finite elements, surfaces, biomembranes, surfactants, director fields
subject: 510 Mathematik

description: We introduce a nonlinear model for the evolution of biomembranes driven by the L2-gradient flow of a novel elasticity functional describing the interaction of a director field on a membrane with its curvature. In the linearized setting of a graph we present a practical finite element method (FEM), and prove a priori estimates. We derive the relaxation dynamics for the nonlinear model on closed surfaces and introduce a parametric FEM. We present numerical experiments for both linear and nonlinear models, which agree well with the expected behavior in simple situations and allow predictions beyond theory.
Surface Fluxes and Tropical Intraseasonal Variability: a Reassessment
Creators: name: Sobel, Adam H.
name: Maloney, Eric D.
name: Bellon, Gilles
name: Frierson, Dargan M. W.
Publisher: name: Columbia University
Year: 2010
Subjects: Heat flux
Precipitation variability
Atmospheric physics
Tropical meteorology

description: The authors argue that interactive feedbacks involving surface moist enthalpy fluxes, both turbulent and radiative, are important to the dynamics of tropical intraseasonal variability. Evidence in favor of this hypothesis includes the observed spatial distribution of intraseasonal variance in precipitation and outgoing longwave radiation, the observed relationship between intraseasonal latent heat flux and precipitation anomalies in regions where intraseasonal variability is strong, and sensitivity experiments performed with a small number of general circulation and idealized models. The authors argue that it would be useful to assess the importance of surface fluxes to intraseasonal variability in a larger number of comprehensive numerical models.
Algebraische Zahlentheorie
Creators: name: Howard, Benjamin V.
name: Kings, Guido
name: Sujatha, Ramdorai
name: Venjakob, Otmar
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 510 Mathematik

description: The workshop brought together researchers from Europe, Japan and the US, who reported on various recent developments in algebraic number theory and related fields. Dominant topics were Shimura varieties, automorphic forms and Iwasawa theory.
Modélisation et extraction de données pour un entrepôt objet
Creators: name: Ravat, Franck
name: Teste, Olivier
name: Gilles, Zurfluh
Publisher: name: arXiv
Year: 2010
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: This paper describes an object-oriented model for designing complex and time-variant data warehouse data. The main contribution is the warehouse class concept, which extends the class concept by temporal and archive filters as well as a mapping function. Filters allow the keeping of relevant data changes whereas the mapping function defines the warehouse class schema from a global data source schema. The approach take into account static properties as well as dynamic properties. The behaviour extraction is based on the use-matrix concept.
Dissipation effects in spin-Hall transport of electrons and holes
Creators: name: Schliemann, John
name: Loss, Daniel
Publisher: name: Universität Regensburg
Year: 2004
Subjects: subject: 530 Physik

description: We investigate the spin-Hall effect of both electrons and holes in semiconductors using the Kubo formula in the correct zero-frequency limit taking into account the finite momentum relaxation time of carriers in real semiconductors. This approach allows us to analyze the range of validity of recent theoretical findings. In particular, the spin-Hall conductivity vanishes for vanishing spin-orbit coupling if the correct zero-frequency limit is performed.
A molecular dynamics investigation of the dissolution of molecular solids
Creators: name: Anand, Abhinav
Publisher: name: University of British Columbia
Year: 2017

description: The dissolution of molecular solids is an important process, which has been studied for over a century. However, a lot of work is still needed for a detailed understanding of the molecular mechanism of dissolution, because of the complex nature of many molecular solids, and the large time scales required for simulation studies. In this thesis we study the dissolution of molecular solids, to examine if classical models (which assume that the rate is proportional to an active surface area) can be used to describe the dissolution profile of these solids. Urea and aspirin molecules are used as models, to study the dissolution process in water under sink conditions, because of their contrasting solubility in water. The dissolution rate in different water models was examined and it was found that they differ considerably. However, the overall mechanism for the dissolution process remains the same. Dissolution was found to be an activated process with the detachment of molecules from the crystal being the rate limiting step. Crystals with different shapes (cubic and cylindrical) were used to study the effect of shape on the dissolution process. The dissolution process for urea was found to occur in three steps, an initial rapid stage, where the molecules at the edges and corners go into the solution, a long intermediate stage with a nearly constant dissolution rate, and a final stage where the crystals lose their crystalline structure and dissolve completely. The fixed rate law stage was found to be described by a simple rate law derived from classical models. It was found that there is an additional step in the dissolution process for aspirin, occurring between the initial rapid stage and the fixed rate law stage, during which the crystal attains a solution annealed shape. The fixed rate law stage was again found to be described by a simple rate law. The results obtained are in agreement with an earlier dissolution study of NaCl crystals, thus it appears that the classical rate laws can be used to describe the dissolution of a variety of complex molecular and ionic crystals.
Λογοτεχνικές απεικονίσεις του θανάτου σε βιβλία για παιδιά προσχολικής και πρωτοσχολικής ηλικίας
Creators: name: Ελένη Ντόλατζα
Publisher: name: ΚΕΙΜΕΝΑ
Year: 2008

description: Στο παρόν άρθρο σχολιάζεται το θέμα του θανάτου σε ενδεικτικά βιβλία παιδικής λογοτεχνίας και ειδικότερα αυτά που απευθύνονται σε μικρές ηλικίες παιδιών. Η προσέγγιση που ακολουθείται επιδιώκει να δείξει ποιες ψυχολογικές αντιδράσεις που συνδέονται με τις διαδιακασίες ή φάσεις πένθους φαίνεται να αποτυπώνονται λογοτεχνικά στο σώμα των βιβλίων που συμπεριλάβαμε. Μας ενδιαφέρει να εστιάσουμε στις διαδικασίες αυτές για να δούμε πώς μεταμορφώνονται σε λόγο λογοτεχνικό που ταυτόχρονα όμως ασκεί και λειτουργίες ανακουφιστικές, κατευναστικές, κοινωνικοποιητικές ή και πληροφοριακές στο μικρό παιδί γύρω από το γεγονός του θανάτου.
description: ΚΕΙΜΕΝΑ, Issue 7 (March 2008)
High-resolution alternating-field technique to determine the magnetocaloric effect of metals down to very low temperatures
Creators: name: Tokiwa, Yoshi
name: Gegenwart, Philipp
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The magnetocaloric effect or "magnetic Grüneisen ratio" $Γ_H=T^{-1}(dT/dH)_S$ quantifies the cooling or heating of a material when an applied magnetic field is changed under adiabatic conditions. Recently this property has attracted considerable interest in the field of quantum criticality. Here we report the development of a low-frequency alternating field technique which allows to perform continuous temperature scans of $Γ_H(T)$ on small single crystals with very high precision and down to very low temperatures. Measurements on doped YbRh$_2$Si$_2$ show that $Γ_H(T)$ can be determined with this technique in a faster and much more accurate way than by calculation from magnetization and specific heat measurements.
On Projections in the Noncommutative 2-Torus Algebra
Creators: name: Eckstein, Michał
Publisher: name: arXiv
Year: 2011
Subjects: subject: K-Theory and Homology (math.KT)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L80 (Primary) 19A13, 19K14, 46L87 (Secondary)

description: We investigate a set of functional equations defining a projection in the noncommutative 2-torus algebra $A_θ$. The exact solutions of these provide various generalisations of the Powers-Rieffel projection. By identifying the corresponding $K_0(A_θ)$ classes we get an insight into the structure of projections in $A_θ$.
Spin-Hall transport of heavy holes in III-V semiconductor quantum wells
Creators: name: Schliemann, John
name: Loss, Daniel
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We investigate spin transport of heavy holes in III-V semiconductor quantum wells in the presence of spin-orbit coupling of the Rashba type due to structure-inversion asymmetry. Similarly to the case of electrons, the longitudinal spin conductivity vanishes, whereas the off-diagonal elements of the spin-conductivity tensor are finite giving rise to an intrinsic spin-Hall effect. For a clean system we find a closed expression for the spin-Hall conductivity depending on the length scale of the Rashba coupling and the hole density. In this limit the spin-Hall conductivity is enhanced compared to its value for electron systems, and it vanishes with increasing strength of the impurity scattering. As an aside, we also derive explicit expressions for the Fermi momenta and the densities of holes in the different dispersion branches as a function of the spin-orbit coupling parameter and the total hole density. These results are of relevance for the interpretation of possible Shubnikov–de Haas measurements detecting the Rashba spin splitting.
Contemporary Seriality: A Roundtable
Creators: name: Grossman, Lev
name: Marcus, Sharon
name: Scott, A. O.
name: Snyder, Julie
Publisher: name: Columbia University
Year: 2019
Subjects: Television series
Serialized fiction
Film series
Podcasts
Criticism
Film criticism

description: A panel discussion about seriality in film, television, literature, and podcasting.
title: КОМПЛЕКСНАЯ СИСТЕМА ПРИМЕНЕНИЯ КОРМОВОЙ ДОБАВКИ  ПРИ МИКОТОКСИКОЗАХ У ЛАКТИРУЮЩИХ КОРОВ
Creators: name: Мирошниченко, Петр Васильевич
name: Лазарев, Сергей Эдуардович
name: Еганян Е, катерина Сергеевна
name: Панфилкина, Елена Викторовна
Publisher: name: ФГБНУ КНЦЗВ
Year: 2021

description: Распространение микроскопических грибов и поражение ими кормового сырья на любом этапе их производства делает практически невозможным полное предотвращения контаминации микотоксинами, поэтому проблема обезвреживания микотоксинов неизбежна. Для решения этой задачи необходимо применение комплексных кормовых добавок, обеспечивающих защиту функций систем органов и элиминацию микотоксинов из организма продуктивных коров.
Flavor and CP Invariant Composite Higgs Models
Creators: name: Redi, Michele
name: Weiler, Andreas
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The flavor protection in composite Higgs models with partial compositeness is known to be insufficient. We explore the possibility to alleviate the tension with CP odd observables by assuming that flavor or CP are symmetries of the composite sector, broken by the coupling to Standard Model fields. One realization is that the composite sector has a flavor symmetry SU(3) or SU(3)_U x SU(3)_D which allows us to realize Minimal Flavor Violation. We show how to avoid the previously problematic tension between a flavor symmetric composite sector and electro-weak precision tests. Some of the light quarks are substantially or even fully composite with striking signals at the LHC. We discuss the constraints from recent dijet mass measurements and give an outlook on the discovery potential. We also present a different protection mechanism where we separate the generation of flavor hierarchies and the origin of CP violation. This can eliminate or safely reduce unwanted CP violating effects, realizing effectively "Minimal CP Violation" and is compatible with a dynamical generation of flavor at low scales.
description: 36 pages; v2 appendix and references added; v3 version to be published in JHEP; v4 discussion on dipoles improved
The Mechanics of Gross Moist Stability
Creators: name: Raymond, David J.
name: Sessions, Sharon L.
name: Sobel, Adam H.
name: Fuchs, Željka
Publisher: name: Columbia University
Year: 2009
Subjects: Atmospheric temperature--Mathematical models
Heat--Convection
Moisture
Meteorology

description: The gross moist stability relates the net lateral outflow of moist entropy or moist static energy from an atmospheric convective region to some measure of the strength of the convection in that region. If the gross moist stability can be predicted as a function of the local environmental conditions, then it becomes the key element in understanding how convection is controlled by the large‐scale flow. This paper provides a guide to the various ways in which the gross moist stability is defined and the subtleties of its calculation from observations and models. Various theories for the determination of the gross moist stability are presented and its roles in current conceptual models for the tropical atmospheric circulation are analyzed. The possible effect of negative gross moist stability on the development and dynamics of tropical disturbances is currently of great interest.
Disorder-induced noncollinear ferromagnetism in models for (III,Mn)V semiconductors
Creators: name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2003
Subjects: subject: 530 Physik

description: We study the ground-state properties of kinetic-exchange models for (III,Mn)V semiconductors with randomly distributed Mn ions. Our method is embedded in a path integral spin-wave-type formalism leading to an effective action for Mn spins only with full Matsubara frequency dependence. The zero-frequency contribution to this action is equivalent to static perturbation theory and characterizes the stability of a given spin configuration, while the component linear in frequency can be interpreted as the joint Berry phase of the Mn and carrier system. For simple parabolic-band carriers the collinear ferromagnetic state with all Mn spins in parallel is always stationary but generically unstable. This instability can be characterized in terms of inverse participation ratios and is due to long-ranged nonlocal spin fluctuations. We also present results for the ground-state magnetization as a function of an external field. For carrier dispersions involving anisotropy induced by spin-orbit coupling the collinear state is not even stationary and therefore also not the ground state. This interplay between the anisotropy in the carrier system and the disorder in the Mn positions reflects recent findings by Zarand and Janko [Phys. Rev. Lett. 89, 047201 (2002)] obtained within the RKKY approximation. The stationarity of the collinear state (with the magnetization pointing in one of the cubic symmetry directions) is restored in the continuum or virtual crystal approximation where disorder is neglected.
Analyse multigraduelle OLAP
Creators: name: Hubert, Gilles
name: Teste, Olivier
Publisher: name: arXiv
Year: 2010
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: Decisional systems are based on multidimensional databases improving OLAP analyses. The paper describes a new OLAP operator named "BLEND" to perform multigradual analyses. The operation transforms multidimensional structures during querying in order to analyse measures according to various granularity levels, which are reorganised into a single parameter. We study valid combinations of the operation in the context of strict hierarchies. First experimentations implement the operation in an R-OLAP framework showing the slight cost of this operation.
Un contre-exemple à la réciproque du critère de Forni pour la positivité des exposants de Lyapunov du cocycle de Kontsevich-Zorich
Creators: name: Delecroix, Vincent
name: Matheus, Carlos
Publisher: name: arXiv
Year: 2011
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We introduce two square-tiled surfaces, one with $8$ squares inside $Ω\mathcal{M}_3(2,2)$, and the other with $9$ squares inside $Ω\mathcal{M}_4(3,3)$, respectively. In these examples, the dimensions of the isotropic subspaces (in absolute homology) generated by the waist curves of the maximal cylinders in any fixed rational direction are $2$ and $3$ respectively. Hence, a geometrical criterion of G. Forni for the non-uniform hyperbolicity of Kontsevich-Zorich (KZ) cocycle can not be applied to these examples. Nevertheless, we prove that there are no vanishing exponents and the spectrum is simple for these two square-tiled surfaces. In particular, the non-vanishing of exponents of KZ cocycle for a regular measure doesn't imply that the support of this measure contains a completely periodic surface whose waist curves of maximal cylinders generates a Lagrangian subspace in its absolute homology.
description: 7 pages, 3 figures. Abstracts in French and English. Main text in French. Final version based on the referee report. To appear in Mathematical Research Letters
The experience of unemployment in primary wage earners
Creators: name: Edwards, David
Publisher: name: University of British Columbia
Year: 2017

description: This study investigated, through a phenomenological mode of inquiry, the experience of unemployment amongst primary wage earners who have experienced non-performance related, involuntary job loss. This study also sought to determine if the experience of unemployment had changed over the preceding thirty years by comparing its findings from figurative illustrations to those of Borgen and Amundson (1987). The association between unemployment and negative mental health, coupled with changes in cultural and work-related attitudes and the absence of studies similar to Borgen and Amundson (1987), provided the rationale for this study. Participants were six adult men and women who had lost their jobs through no fault of their own. Individual interviews, followed-up by post-analysis member checks, were conducted with each participant. Six main themes, and 12 subthemes, emerged from data analysis. The main themes were: (1) anticipation of and immediate response to job loss; (2) positive emotional responses to job loss; (3) negative emotional responses to job loss; (4) job search and financial challenges; (5) support; and (6) emergent optimism and problem solving. Three trends were found to the figurative illustrations, with elements that were both similar to and different from those in Borgen and Amundson (1987). Of note, all of the participants’ initial responses to job loss differed from the 1987 comparison group. This was attributable to participants either being accustomed to job loss, or to having initial post-employment plans in place. This study contributes to the understanding of the experience of unemployment, and provides suggestions for those in the helping profession who work with those who are currently, or at risk of becoming, unemployed. Implications for future research are also discussed.
Arbeitsgemeinschaft: Quantum Ergodicity
Creators: name: Bunke, Ulrich
name: Nonnenmacher, Stephane
name: Schubert, Roman
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 510 Mathematik

description: Quantum Ergodicity aims at understanding the eigenstates of quantum mechanical systems admitting chaotic classical limiting dynamics. A paradigmatic system is the Laplace-Beltrami operator on a compact manifold of negative sectional curvature: its classical limit is the geodesic flow on the manifold, which is of Anosov type. Although no explicit expression is available for the eigenstates, one may use various tools from semiclassical analysis in order to gather some partial information on their structure. The central result (Quantum Ergodicity Theorem) states that almost all eigenstates are equidistributed over the energy shell, in the semiclassical limit, provided the classical system is ergodic. The lectures review the background techniques of semiclassical analysis and ergodic theory, give several versions of the QE theorem, and present several extensions of the result, which apply to specific systems, for instance chaotic systems enjoying arithmetic symmetries.
Intercomparison of methods of coupling between convection and large‐scale circulation: 2. Comparison over nonuniform surface conditions
Creators: name: Daleu, Chimene L.
name: Plant, Robert S.
name: Woolnough, Steve J.
name: Sessions, Sharon L.
name: Herman, Michael J.
name: Sobel, Adam H.
name: Wang, Shuguang
name: Kim, Daehyun
name: Cheng, A.
name: Bellon, Gilles
name: Peyrillé, Philippe
name: Ferry, Frédéric
name: Siebesma, Pier
name: Van Ulft, Lambertus H.
Publisher: name: Columbia University
Year: 2016
Subjects: Convection (Meteorology)
Atmospheric circulation--Mathematical models
Meteorology
Precipitation (Meteorology)
Clouds

description: As part of an international intercomparison project, the weak temperature gradient (WTG) and damped gravity wave (DGW) methods are used to parameterize large‐scale dynamics in a set of cloud‐resolving models (CRMs) and single column models (SCMs). The WTG or DGW method is implemented using a configuration that couples a model to a reference state defined with profiles obtained from the same model in radiative‐convective equilibrium. We investigated the sensitivity of each model to changes in SST, given a fixed reference state. We performed a systematic comparison of the WTG and DGW methods in different models, and a systematic comparison of the behavior of those models using the WTG method and the DGW method. The sensitivity to the SST depends on both the large‐scale parameterization method and the choice of the cloud model. In general, SCMs display a wider range of behaviors than CRMs. All CRMs using either the WTG or DGW method show an increase of precipitation with SST, while SCMs show sensitivities which are not always monotonic. CRMs using either the WTG or DGW method show a similar relationship between mean precipitation rate and column‐relative humidity, while SCMs exhibit a much wider range of behaviors. DGW simulations produce large‐scale velocity profiles which are smoother and less top‐heavy compared to those produced by the WTG simulations. These large‐scale parameterization methods provide a useful tool to identify the impact of parameterization differences on model behavior in the presence of two‐way feedback between convection and the large‐scale circulation.
The tropical rain belts with an annual cycle and a continent model intercomparison project: TRACMIP
Creators: name: Voigt, Aiko
name: Biasutti, Michela
name: Scheff, Jacob S.
name: Bader, Jürgen
name: Bordoni, Simona
name: Codron, Francis
name: Dixon, Ross D.
name: Jonas, Jeffrey A.
name: Kang, Sarah M.
name: Klingaman, Nicholas P.
name: Leung, Ruby
name: Lu, Jian
name: Mapes, Brian
name: Maroon, Elizabeth A.
name: McDermid, Sonali
name: Park, Jong‐Yeon
name: Roehrig, Romain
name: Rose, Brian E. J.
name: Russell, Gary L.
name: Seo, Jeongbin
name: Toniazzo, Thomas
name: Wei, Ho‐Hsuan
name: Yoshimori, Masakazu
name: Vargas Zeppetello, Lucas R.
Publisher: name: Columbia University
Year: 2016
Subjects: Rain and rainfall--Analysis
Rain and rainfall--Simulation methods
Atmospheric models
Climatic changes
Climatology
Meteorology

description: This paper introduces the Tropical Rain belts with an Annual cycle and a Continent Model Intercomparison Project (TRACMIP). TRACMIP studies the dynamics of tropical rain belts and their response to past and future radiative forcings through simulations with 13 comprehensive and one simplified atmosphere models coupled to a slab ocean and driven by seasonally varying insolation. Five idealized experiments, two with an aquaplanet setup and three with a setup with an idealized tropical continent, fill the space between prescribed‐SST aquaplanet simulations and realistic simulations provided by CMIP5/6. The simulations reproduce key features of present‐day climate and expected future climate change, including an annual‐mean intertropical convergence zone (ITCZ) that is located north of the equator and Hadley cells and eddy‐driven jets that are similar to present‐day climate. Quadrupling CO2 leads to a northward ITCZ shift and preferential warming in Northern high latitudes. The simulations show interesting CO2‐induced changes in the seasonal excursion of the ITCZ and indicate a possible state dependence of climate sensitivity. The inclusion of an idealized continent modulates both the control climate and the response to increased CO2; for example, it reduces the northward ITCZ shift associated with warming and, in some models, climate sensitivity. In response to eccentricity‐driven seasonal insolation changes, seasonal changes in oceanic rainfall are best characterized as a meridional dipole, while seasonal continental rainfall changes tend to be symmetric about the equator. This survey illustrates TRACMIP's potential to engender a deeper understanding of global and regional climate and to address questions on past and future climate change.
Stratified Spaces: Joining Analysis, Topology and Geometry
Creators: name: Banagl, Markus
name: Bunke, Ulrich
name: Weinberger, Shmuel
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 510 Mathematik

description: For manifolds, topological properties such as Poincaré duality and invariants such as the signature and characteristic classes, results and techniques from complex algebraic geometry such as the Hirzebruch-Riemann-Roch theorem, and results from global analysis such as the Atiyah-Singer index theorem, worked hand in hand in the past to weave a tight web of knowledge. Individually, many of the above results are in the meantime available for singular stratified spaces as well. The 2011 Oberwolfach workshop “Stratified Spaces: Joining Analysis, Topology and Geometry” discussed these with the specific aim of cross-fertilization in the three contributing fields.
Superconductivity, superfluidity and zero-point oscillations
Creators: name: Vasiliev, B. V.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Currently it is thought that in order to explain the phenomenon of superconductivity is necessary to understand the mechanism of formation of electron pairs. However, the paired electrons cannot form a superconducting condensate. They perform disorderly zero-point oscillations and there are no attractive forces in their ensemble. To create a unified ensemble of particles, the pairs must order their zero-point fluctuations so that an attraction between the particles appears. For this reason, the ordering of zero-point oscillations in the electron gas is the cause of superconductivity and the parameters characterizing this order determine the properties of superconductors. The model of condensation of zero-point oscillations creates the possibility to obtain estimates for the critical parameters of elementary superconductors, which are also in the satisfactory agreement with measured data. On the another hand, the phenomenon of superfluidity in He-4 and He-3 can be similarly explained due to the ordering of zero-point fluctuations. Thus it is established that the both related phenomena are based on the same physical mechanism.
description: arXiv admin note: substantial text overlap with arXiv:1008.2691, arXiv:1005.0280, arXiv:1101.1229, arXiv:1101.0330
Coupling with ocean mixed layer leads to intraseasonal variability in tropical deep convection: Evidence from cloud‐resolving simulations
Creators: name: Anber, Usama Mostafa
name: Wang, Shuguang
name: Sobel, Adam H.
Publisher: name: Columbia University
Year: 2017
Subjects: Clouds--Models
Atmospheric models
Meteorology
Vertical wind shear
Ocean-atmosphere interaction

description: The effect of coupling a slab ocean mixed layer to atmospheric convection is examined in cloud‐resolving model (CRM) simulations in vertically sheared and unsheared environments without Coriolis force, with the large‐scale circulation parameterized using the Weak Temperature Gradient (WTG) approximation. Surface fluxes of heat and moisture as well as radiative fluxes are fully interactive, and the vertical profile of domain‐averaged horizontal wind is strongly relaxed toward specified profiles with vertical shear that varies from one simulation to the next. Vertical wind shear is found to play a critical role in the simulated behavior. There exists a threshold value of the shear strength above which the coupled system develops regular oscillations between deep convection and dry nonprecipitating states, similar to those found earlier in a much more idealized model which did not consider wind shear. The threshold value of the vertical shear found here varies with the depth of the ocean mixed layer. The time scale of the spontaneously generated oscillations also varies with mixed layer depth, from 10 days with a 1 m deep mixed layer to 50 days with a 10 m deep mixed layer. The results suggest the importance of the interplay between convection organized by vertical wind shear, radiative feedbacks, large‐scale dynamics, and ocean mixed layer heat storage in real intraseasonal oscillations.
Quantum computing in optical microtraps based on the motional states of neutral atoms
Creators: name: Eckert, K.
name: Mompart, J.
name: Yi, X. X.
name: Schliemann, John
name: Bruss, D.
name: Birkl, G.
name: Lewenstein, M.
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: 530 Physik

description: We investigate quantum computation with neutral atoms in optical microtraps where the qubit is implemented in the motional states of the atoms, i.e., in the two lowest vibrational states of each trap. The quantum gate operation is performed by adiabatically approaching two traps and allowing tunneling and cold collisions to take place. We demonstrate the capability of this scheme to realize a square root of swap gate, and address the problem of double occupation and excitation to other unwanted states. We expand the two-particle wave function in an orthonormal basis and analyze quantum correlations throughout the whole gate process. Fidelity of the gate operation is evaluated as a function of the degree of adiabaticity in moving the traps. Simulations are based on rubidium atoms in state-of-the-art optical microtraps with quantum gate realizations in the few tens of milliseconds duration range.
Entanglement in SU(2)-invariant quantum systems: The positive partial transpose criterion and others
Creators: name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We study entanglement in mixed bipartite quantum states which are invariant under simultaneous SU(2) transformations in both subsystems. Previous results on the behavior of such states under partial transposition are substantially extended. The spectrum of the partial transpose of a given SU(2)-invariant density matrix ρ is entirely determined by the diagonal elements of ρ in a basis of tensor-product states of both spins with respect to a common quantization axis. We construct a set of operators which act as entanglement witnesses on SU(2)-invariant states. A sufficient criterion for ρ having a negative partial transpose is derived in terms of a simple spin correlator. The same condition is a necessary criterion for the partial transpose to have the maximum number of negative eigenvalues. Moreover, we derive a series of sum rules which uniquely determine the eigenvalues of the partial transpose in terms of a system of linear equations. Finally we compare our findings with other entanglement criteria including the reduction criterion, the majorization criterion, and the recently proposed local uncertainty relations.
Contraintes pour modèle et langage multidimensionnels
Creators: name: Ghozzi, Faiza
name: Ravat, Franck
name: Teste, Olivier
name: Zurfluh, Gilles
Publisher: name: arXiv
Year: 2010
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: This paper defines a constraint-based model dedicated to multidimensional databases. The model we define represents data through a constellation of facts (subjects of analyse) associated to dimensions (axis of analyse), which are possibly shared. Each dimension is organised according to several hierarchies (views of analyse) integrating several levels of data granularity. In order to insure data consistency, we introduce 5 semantic constraints (exclusion, inclusion, partition, simultaneity, totality) which can be intra-dimension or inter-dimensions; the intra-dimension constraints allow the expression of constraints between hierarchies within a same dimension whereas the inter-dimensions constraints focus on hierarchies of distinct dimensions. We also study repercussions of these constraints on multidimensional manipulations and we provide extensions of the multidimensional operators.
title: "Statua di togato con testa di Ermarco non pertinente", arte romana, inv. s.n. (ITA/EN)
title: Scheda catalogo digitale Borghese
titleType: AlternativeTitle
Creators: name: Clementi, Jessica
name: Galleria Borghese
Publisher: name: Galleria Borghese
Year: 2025

description: Pubblicazione delle schede delle opere conservate nel museo ed estratte dal catalogo digitale di Galleria Borghese, nelle due versioni esistenti online, in italiano e inglese.

Collegamento al catalogo digitale:

ITA: https://www.collezionegalleriaborghese.it/

EN: https://www.collezionegalleriaborghese.it/en
Holonomy reductions of Cartan geometries and curved orbit decompositions
Creators: name: Cap, Andreas
name: Gover, A. Rod
name: Hammerl, Matthias
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C29, 53B15, 53A30, 53A20, 58D19, 58J70

description: We develop a holonomy reduction procedure for general Cartan geometries. We show that, given a reduction of holonomy, the underlying manifold naturally decomposes into a disjoint union of initial submanifolds. Each such submanifold corresponds to an orbit of the holonomy group on the modelling homogeneous space and carries a canonical induced Cartan geometry. The result can therefore be understood as a `curved orbit decomposition'. The theory is then applied to the study of several invariant overdetermined differential equations in projective, conformal and CR-geometry. This makes use of an equivalent description of solutions to these equations as parallel sections of a tractor bundle. In projective geometry we study a third order differential equation that governs the existence of a compatible Einstein metric. In CR-geometry we discuss an invariant equation that governs the existence of a compatible Kähler-Einstein metric.
description: v2: major revision; 30 pages v3: final version to appear in Duke Math. J
Shot noise and spin-orbit coherent control of entangled and spin-polarized electrons
Creators: name: Egues, J. Carlos
name: Burkard, Guido
name: Saraga, D. S.
name: Schliemann, John
name: Loss, Daniel
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We have carried out a thorough study of current and noise for spin-polarized and spin-entangled electrons in a beamsplitter geometry, including a local spin-orbit interaction �Rashba and Dresselhaus� in one of the incoming arms. We have considered incoming leads with one or two channels, as well as backscattering effects. The channels can be coupled via the SO interaction for incoming energies near the band crossing. We have found that the spin-orbit interaction is a useful mechanism to coherently rotate spin states. Such rotation can be used to modulate noise signals, thus providing unique signatures of spin polarization and spin entanglement. For spin-polarized electrons, noise measurements can give a direct measure of the degree of polarization along different directions. For electron pairs, the coupling between the channels can play an important role. For pairs with incoming energies near the band crossing injected into one of the channels, we find an additional modulation due to the coherent transfer of electrons between the two channels. In this case, noise measurement allows us to distinguish all the different triplets states defined along the y direction, in addition to the singlet. Furthermore, for equal strengths the combined effect of the Rashba and Dresselhaus interactions can partially cancel out. In this case, the spin and orbital degrees of freedom are separable, the interband coupling essentially disappears, and the propagation of spin states is robust against scattering off nonmagnetic impurities. We have also considered the influence of backscattering in the beam-splitter with a single channel. The main effect is an additional contribution related to the partition noise due to the tunnel barrier describing the backscattering. This reduces the visibility of the oscillations in the shot noise as the SO rotation angle SO is varied. It also reduces the maximal noise value found for perfect antibunching of singlets. We have generalized earlier results for the shot noise of entangled electrons by allowing the injection of wave packets, i.e., coherent superpositions of discrete momentum eigenstates �plane waves�. We have found a general analytical formula for the two-particle interference visibility �h�2 in terms of all three relevant energy scales �, �, and �. Our new result contains and generalizes both the discrete single-level case and the continuum case. Finally, we have developed a simple heuristic picture for the noise based on number operators in the different leads and the relevant transmission and reflection probability amplitudes in the beamsplitter. Within this picture we can more intuitively rederive some of the formulas for the noise— previously derived within the rigorous scattering formalism �Sec. III�—in the presence of spin-orbit interaction and backscattering in the incoming leads.
title: МЕХАНИЗМ РАЗВИТИЯ НАИБОЛЕЕ ЗНАЧИМЫХ МИКОТОКСИКОЗОВ КРУПНОГО РОГАТОГО СКОТА
Creators: name: Мирошниченко, Петр Васильевич
name: Лазарев, Сергей Эдуардович
name: Панфилкина, Елена Викторовна
Publisher: name: ФГБНУ КНЦЗВ
Year: 2021

description: Рассмотрен проведенный мониторинг исследований и установлено, что наиболее выраженное влияние в патогенезе микотоксикозов крупного рогатого скота вызывают микотоксины афлатоксин В1 и зеараленон. Особенно восприимчивы высокопродуктивные коровы и молодняк. Афлатоксикоз и зеароленонтоксикоз являются причиной раннего выбытия продуктивных коров в связи с патологией печени, снижением продуктивности и нарушением воспроизводства. Ущерб от этих основных представителей токсикантов наиболее значимый на сегодняшний день в молочном животноводстве.
Is the five-flow conjecture almost false?
Creators: name: Jacobsen, Jesper L.
name: Salas, Jesus
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The number of nowhere zero Z_Q flows on a graph G can be shown to be a polynomial in Q, defining the flow polynomial Φ_G(Q). According to Tutte's five-flow conjecture, Φ_G(5) > 0 for any bridgeless G.A conjecture by Welsh that Φ_G(Q) has no real roots for Q \in (4,\infty) was recently disproved by Haggard, Pearce and Royle. These authors conjectured the absence of roots for Q \in [5,\infty). We study the real roots of Φ_G(Q) for a family of non-planar cubic graphs known as generalised Petersen graphs G(m,k). We show that the modified conjecture on real flow roots is also false, by exhibiting infinitely many real flow roots Q>5 within the class G(nk,k). In particular, we compute explicitly the flow polynomial of G(119,7), showing that it has real roots at Q\approx 5.0000197675 and Q\approx 5.1653424423. We moreover prove that the graph families G(6n,6) and G(7n,7) possess real flow roots that accumulate at Q=5 as n\to\infty (in the latter case from above and below); and that Q_c(7)\approx 5.2352605291 is an accumulation point of real zeros of the flow polynomials for G(7n,7) as n\to\infty.
description: 44 pages (LaTeX2e). Includes tex file, three sty files, and a mathematica script polyG119_7.m. Many improvements from version 3, in particular Sections 3 and 4 have been mostly re-writen, and Sections 7 and 8 have been eliminated. (This material can now be found in arXiv:1303.5210.) Final version published in J. Combin. Theory B
Analyzing Walksat on random formulas
Creators: name: Coja-Oghlan, Amin
name: Frieze, Alan
Publisher: name: arXiv
Year: 2011
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 68R01

description: Let F be a uniformly distributed random k-SAT formula with n variables and m clauses. We prove that the Walksat algorithm from Papadimitriou (FOCS 1991)/Schoning (FOCS 1999) finds a satisfying assignment of F in polynomial time w.h.p. if m/n0. This is an improvement by a factor of $Θ(k)$ over the best previous analysis of Walksat from Coja-Oghlan, Feige, Frieze, Krivelevich, Vilenchik (SODA 2009).
Spin susceptibilities, spin densities, and their connection to spin currents
Creators: name: Erlingsson, Sigurdur I.
name: Schliemann, John
name: Loss, Daniel
Publisher: name: Universität Regensburg
Year: 2005
Subjects: subject: 530 Physik

description: We calculate the frequency-dependent spin susceptibilities for a two-dimensional electron gas with both Rashba and Dresselhaus spin-orbit interactions. The resonances of the susceptibilities depend on the relative values of the Rashba and Dresselhaus spin-orbit constants, which could be manipulated by gate voltages. We derive exact continuity equations, with source terms, for the spin density and use those to connect the spin current to the spin density. In the free electron model the susceptibilities play a central role in the spin dynamics since both the spin density and the spin current are proportional to them.