Готові списки джерел за темами / Complex spin systems

Добірка наукової літератури з теми "Complex spin systems"

Автор: Grafiati
Опубліковано: 6 вересня 2023

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Статті в журналах з теми "Complex spin systems"

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Mézard, Marc. "Spin glasses and optimization in complex systems." Europhysics News 53, no. 1 (2022): 15–17. http://dx.doi.org/10.1051/epn/2022105.

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Spin glasses are useless. Even the most imaginative physicists, submitted to grant pressure, could not find applications for these materials. Yet their study, triggered by pure intellectual interest, has created a formidable new branch of statistical physics distinguished this year by the Nobel prize attributed to Giorgio Parisi.
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2

Tareyeva, E. E., T. I. Schelkacheva, and N. M. Chtchelkatchev. "Spin-glass-type state in complex nonmagnetic systems." Theoretical and Mathematical Physics 160, no. 2 (August 2009): 1190–202. http://dx.doi.org/10.1007/s11232-009-0110-7.

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3

Andrianov, Timofey, and Anatoly Vedyayev. "Numerical simulation of spin transport in systems with complex geometry." EPJ Web of Conferences 185 (2018): 01021. http://dx.doi.org/10.1051/epjconf/201818501021.

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The spin diffusion and charge equations in Levy-Fert and Waintal models were numerically solved, using finite element method in complex non-collinear geometry with strongly inhomogeneous current flow. As an illustration, spin-dependent transport through a magnetic pillar and nonmagnetic spacer separating two magnetic layers was investigated. It is shown, that the structure with number of pillars gives a higher value of Giant Magnetoresistance (GMR) effect rather than a structure with one pillar of equivalent diameter. The inhomogeneity of spin currents, which has one of the strongest impacts on GMR effect value leads to the occurrence of spin-current vortices. Introduction of lT and lL lengths in Waintal model gives a better description of angular dependence of GMR effect rather than Levy-Fert model.
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4

Hammes-Schiffer, Sharon. "Quantum effects in complex systems: summarizing remarks." Faraday Discussions 221 (2020): 582–88. http://dx.doi.org/10.1039/c9fd00097f.

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Quantum mechanical phenomena such as coherence, spin dynamics, and tunneling have been observed in biological, electrochemical, polymeric, and many other condensed phase processes. This paper summarizes the diverse contributions to the Faraday Discussion on quantum effects in complex systems.
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5

Bora, Shuchi, H. C. Chandola, and B. S. Rajput. "Realizations of generators of complex angular momentum." Canadian Journal of Physics 68, no. 7-8 (July 1, 1990): 599–603. http://dx.doi.org/10.1139/p90-090.

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We use the generators of complex angular momentum in complex c3 space and derive the realizations of the homogeneous Lorentz group for nonzero real mass, zero mass, and imaginary mass systems. We use the appropriate little group for different systems to calculate the modifications in the spin contribution to angular momentum and the unphysical continuous spin representations are shown to be eliminated. We diagonalize the helicity operator in c3 space and obtain the generators of complex angular-momentum operators, which are shown to lead, in a general manner, to the standard helicity representations of the Poincare group for timelike and spacelike systems.
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6

Rüegge, Daniel, and Hanns Fischer. "Kinetic electron spin resonance spectroscopy of complex reaction systems." Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases 84, no. 10 (1988): 3187. http://dx.doi.org/10.1039/f19888403187.

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7

Borgs, C., J. T. Chayes, and J. Fröhlich. "Dobrushin states for classical spin systems with complex interactions." Journal of Statistical Physics 89, no. 5-6 (December 1997): 895–928. http://dx.doi.org/10.1007/bf02764213.

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8

Gibbon, J. D., and E. S. Titi. "Cluster formation in complex multi-scale systems." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 461, no. 2062 (August 12, 2005): 3089–97. http://dx.doi.org/10.1098/rspa.2005.1548.

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Based on the competition between members of a hierarchy of length scales in complex multi-scale systems, it is shown how clustering of active quantities into concentrated sets, like bubbles in a Swiss cheese, is a generic property that dominates the intermittent structure. The halo-like surfaces of these clusters have scaling exponents lower than that of their kernels, which can be as high as the domain dimension. Possible examples include spots in fluid turbulence and droplets in spin-glasses.
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9

Kapitan, Vitaliy Yu, Yuriy A. Shevchenko, Alexander V. Perzhu, and Egor V. Vasiliev. "Thermodynamic Properties of Heisenberg Spin Systems." Key Engineering Materials 806 (June 2019): 142–54. http://dx.doi.org/10.4028/www.scientific.net/kem.806.142.

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We present the simulation results of magnetic 2D and 3D structures with direct (for both of them) and Dzyaloshinskii-Moriya (DMI) (for 2D lattice) interactions in the frame of the Heisenberg model. We have adapted the multipath Metropolis algorithm for systems with complex types of exchange interactions and rough energy landscapes. We show the temperature behavior of magnetization, energy, and heat capacity, and reveal its critical temperatures and order parameter.
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IPATE, FLORENTIN, RALUCA LEFTICARU, and CRISTINA TUDOSE. "FORMAL VERIFICATION OF P SYSTEMS USING SPIN." International Journal of Foundations of Computer Science 22, no. 01 (January 2011): 133–42. http://dx.doi.org/10.1142/s0129054111007897.

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This paper presents an approach to P system verification using the Spin model checker. It proposes a P system implementation in PROMELA, the modeling language accepted by SPIN. It also provides the theoretical background for transforming the temporal logic properties expressed for the P system into properties of the executable implementation. Furthermore, a comparison between P systems verification using SPIN and NUSMV is realized. The results obtained show that the PROMELA implementation is more adequate, especially for verifying more complex models, such as P systems that model ecosystems.
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Дисертації з теми "Complex spin systems"

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Hoang, Danh tai. "Phase transition and Spin transport in Complex Systems : Frustrated spin systems, Molecular and Liquid Crystals." Thesis, Cergy-Pontoise, 2012. http://www.theses.fr/2012CERG0621/document.

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Dans la thèse, nous avons utilisé des simulations de Monte Carlo combinées avec différentes techniques efficaces tels que les méthodes d'histogramme pour étudier les transitions de phase et transport des spins dans différents systèmes. La première partie est consacrée à l'étude des transition de phase dans les systèmes de spins frustrés: (i) le modèle J_1-J_2 avec des spins Ising dans le régime antiferromagnétique complet, (ii) le modèle HCP avec des spins Ising et des spins $XY$ dans le régime antiferromagnétique complet. Les résultats obtenus montrent en effet une transition du premier ordre que l'on trouve plus tôt dans d'autres systèmes frustrés. La deuxième partie montre les état fondamental et transitions de phase dans les cristaux moléculaires et dans les liquides de dimères. Pour faire face à ces systèmes, nous avons utilisé le modèle de Potts en tenant compte de l'interaction dipolaire pour expliquer structures périoques en couches observées expérimentalement. Les résultats montrent des effets étonnants de cette interaction à longue portée. L'effet de l'interaction d'échange de surface a été pris en compte dans ce travail. Finalement, nous avons calculé la résistivité des spins itinérants. Nous nous sommes concentrés en particulier sur les effets des fluctuations de spin dans la région de transition de phase. Des résultats intéressants ont été obtenus montrant une forte corrélation entre les fluctuations de spin et le comportement de la résistivité
In this thesis, we have used Monte Carlo simulations combined with different efficient techniques such as histogram methods to study the phase transitions and spin transport in various systems. The first part is devoted to the investigation of phase transition in frustrated spin systems: (i) the J_1-J_2 model with Ising spin in the full antiferromagnetic regime, (ii) the HCP lattice with both Ising and XY spin in the full antiferromagnetic regime. The results obtained show indeed a first-order transition as found earlier in other frustrated systems. The second part shows the ground state and phase transitions in molecular crystals and in dimer liquids. To deal with these systems, we have used the Potts model taking into the account the dipolar interaction to explain long-period layered structures experimentally observed. The results show amazing effects of this long-range interaction. The effect of surface exchange interaction has been considered in this work. Finally, we describe the resistivity of itinerant spins. We focused in particular on the effects of spin fluctuations in the phase transition region. Interesting results have been obtained showing a strong correlation between spin fluctuations and the behavior of the resistivity
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2

Elbahrawy, Mohammed. "High field electron magnetic resonance in complex correlated spin systems." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-39380.

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In this thesis we used ESR to investigate magnetic properties of low D vandium and copper oxides in which small quantum spins are arranged in 1D chains and 2D layers. The thesis covers five different low dimensional spin systems. They turned out to be experimental reliazation of some of the most intersiting theoritical models in the field of quantum magnetism.
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3

Huang, Yang. "Analysis of NMR Spin-lattice Relaxation Dispersion on Complex Systems." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-110721.

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This thesis focus on the analysis of spin-lattice NMRD relaxation profilesmeasured in various complex systems such as proteins, zeolites and ionicliquids. Proton, deuterium and fluoride T1-NMRD relaxation profiles wereobtained from a fast-field cycling (FFC) instrument. It is found that alsopossible to obtain NMRD profiles from the molecular dynamics (MD)simulation trajectories. NMRD Profiles were analyzed by using differentrelaxation models, such as the Solomon-Bloembergen-Morgan (SBM) theoryand the Stochastic Liouville (SL) theory. Paper I described the hydration of protein PrxV obtained from a MDsimulation, and compared with the picture emerges from an analysis byusing a generally accepted relaxation model [appendix C]. The result showsthat the information from NMRD analysis is an averaged picture of watermolecules with similar relaxation times; and the MD simulations containsinformation of all types of interested water molecules with differentresidence times. In paper II NMRD profiles have been used to characterize the hydration ofthe oxygen-evolving complex in state S1 of photosystem II. NMRDexperiments were performed on both intact protein samples and Mndepletedsamples, and characteristic dispersion difference were foundbetween 0.03 MHz to 1 MHz; approximately. Both the SBM theory and theSL theory have been used to explain this dispersion difference, and it isfound that this is due to a paramagnetic enhancement of 1-2 water moleculesnearby ~10 Å from the spin center of the Mn4CaO5 cluster. The result showsthe reorientation of the molecular cluster is in μs time interval. Whencompare these two theories, the SL theory presented a better interpretationbecause parameters obtained from the SBM theory shows they didn’t fulfilthe presupposed perturbation criterion (the Kubo term). Paper III deals with the water dynamics in the restricted/confined spaces inthe zeolite samples (H-ZSM-5 and NH4-ZSM-5) and obtained by proton anddeuterium spin-lattice NMRD profiles. The results show that the spin-latticeNMRD can be used to characterize various zeolites. The temperature has aweak effect on the relaxation rate R1, but the change of different counter ionsmay change the hydration and the translational diffusion pores and givedifferent R1. Proton and fluoride NMRD profiles and MD simulations were both used tostudy the dynamics of BMIM[PF6] in paper IV. Results indicate the reorientation of the molecules are in the ns time regime, and the effectivecorrelation time obtained from 1H and 19F are the same. From the MDsimulation it is found the reorientation of [PF6]- ions is much faster (in ps)compare with BMIM+ ion which moves in the ns time range. With previous results, the FFC NMRD profiles are indeed very informativetools to study the molecular dynamics of complex systems. The MDsimulation can be used as a complementary method to obtain detailedinformation. By combine these two methods, it provide a more colorfulpicture in the study of protein hydration and liquid molecular dynamics.
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Lechner, Barbara Angelika Johanna. "Studying complex surface dynamical systems using helium-3 spin-echo spectroscopy." Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/269776.

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The aim of the present thesis is to extend the range of application of the helium-3 spin-echo (HeSE) technique to complex surface dynamical systems. A twofold approach is presented: the development of improved experimental equipment and the investigation of a series of prototypical aromatic adsorbate systems. Chapter 1 discusses the motivation for this work and compares HeSE with other techniques probing surface motion. Subsequently, an introduction to the HeSE method is given in Chapter 2, explaining the theoretical background and describing the main components of the Cambridge spectrometer as well as the principle data aquisition and interpretation methods. Chapters 3 and 4 describe the development and testing of two new pieces of equipment. MiniScat, a compact helium atom scattering apparatus, has been designed as a sample preparation facility to enable structural studies and increase the experimental throughput. A new supersonic helium beam source improves the resolution of the HeSE spectrometer by a factor of 5.5 and extends accessible timescales into the nanometre range. The dynamics of cyclopentadienyl (Cp) on Cu(111) are presented in Chapter 5. The ionically bound Cp is remarkably mobile, moving in single jumps between adjacent hollow sites over an energy barrier of 41 ± 1 meV. The data exhibit multicomponent lineshapes that allow the determination of the energy difference between fcc and hcp sites of 12.3±0.3 meV in a Bayesian method probing the probability space of all data combined. Molecular dynamics (MD) simulations provide a friction coecient of 2.5 ± 0.5 ps1. Chapter 6 shows that a physisorbed pyrrole hops between bridge sites on Cu(111). Strong lateral interactions alter the lineshapes from a predicted double exponential towards an apparent single exponential decay. First principles density functional theory calculations by Sacchi and Jenkins reveal that a large contribution to the experimentally determined apparent activation energy of 53 ± 4 meV arises from a site-dependence in the zero point energies, primarily of the vibrational C–H and N–H out-of-plane bending and ring torsion modes which are not directly involved in the di↵usion process. The surface dynamics of thiophene/Cu(111) are investigated in Chapter 7. Thiophene adsorbs on top sites and forms a covalent S–Cu bond. Two competing activated processes manifest themselves in a kink in the Arrhenius plot: jump di↵usion between adjacent top sites over a barrier of 59 ± 4 meV and rotation around the S–Cu anchor point over a barrier of 22±2 meV. In addition, vertical motion relative to the surface is observed. MD simulations of the di↵usive motion reveal an exceptionally high friction of 5 ± 2 ps1.
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Abdulhameed, Abbas Abdulazeez. "Combining SysML and SystemC to Simulate and Verify Complex Systems." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2045/document.

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De nombreux systèmes hétérogènes sont complexes et critiques. Ces systèmes intègrent du logiciel et des composants matériels avec des interactions fortes entre ces composants. Dans ce contexte, il est devenu absolument nécessaire de développer des méthodologies et des techniques pour spéciier et valider ces systèmes.Dans l'ingénierie des systèmes, les exigences sont l'expression des besoins qu'un produit spécifique ou un service doit réaliser. Elles sont définies formellement à de nombreuses occasions dans l'ingénierie des systèmes complexes. Dans ce type de système, deux catégories d'exigence sont présentes : les exigences non-fonctionnelles telles que la performance et la fiabilité, les exigences fonctionnelles telles que la vivacité. Pour valider ces exigences, un environnement permettant de simuler et vérifier ces propriétés est essentiel.Dans notre travail, nous proposons une méthodologie basée sur SysML et combinée avec SystemC et Promela/SPIN pour spéciier et valider des systèmes complexes. Cette approche est basée sur l'ingénierie dirigée par les modèles pour premièrement traduire des modèles SysML en SystemC afin de réaliser des simulations et deuxièmement traduire des diagrammes d'état SysML en Promela/SPINain de vérifier des propriétés temporelles extraites des exigences. Cette approche est expérimentée sur une étude de cas pour démontrer sa faisabilité
Heterogeneous Systems are complex and become very critical. These systems integrate software andhardware components with intensive interaction between them. In this context, there is a strongnecessity to develop methodologies and techniques to specify and validate these systems.In engineering, the requirements are the expression of needs on what a particular product or a serviceshould be or to make. They are used most of the time in a formal sense in the systems engineering.In this kind of systems, several types of requirements are present: non-functional requirements suchas the performance and the reliability and functional requirements such as the liveliness. To validatethese requirements of a system, an environment to simulate and to check the properties is essential.In our work, we propose a methodology based on SysML combined with SystemC and Promela/SPINto specify and validate complex systems. This approach is based on Model Driven Engineeringtechniques to irstly translate SysML models to systemC with the aim of simulation and to mapSysML behavioral diagrams to Promela/SPIN in order to verify temporal properties extracted fromthe requirements. The approach is experimented on case studies to demonstrate its feasibility
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MACETTI, GIOVANNI. "TOPOLOGICAL DESCRIPTORS ENABLING NOVEL DISSECTIONS OF ELECTRON POSITION AND SPIN PROPERTIES IN COMPLEX MOLECULAR SYSTEMS." Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/615357.

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Macroscopic and microscopic properties of molecular and solid-state systems are intimately related to the their electronic structure. The electron position and spin densities, which represent the probability distributions to find all or unpaired electrons in the space, contain information concerning several chemical-relevant properties, such as the chemical bonding and the magnetic behaviour. Understanding the fine atomic-level mechanism behind these properties is a key step to design chemical modifications to properly tune and develop materials or molecules with specific features. Topological descriptors can be used to extract information from these electron distributions. In this work, novel applications of the source function descriptor have been developed to gain further insights on the electron and spin density-related properties. These developments, together with other topological descriptors, were used to get further insights on relevant chemical systems. Firstly, the source function reconstruction was enlarged to a multi-dimensional grid of points with a particular focus on the two-dimensional maps. This analysis allows to see the ability of chosen subsets of atoms to reconstruct the density in the selected area within a cause-effect relationship and to rationalise the chemical or magnetic behaviours. The source function partial reconstructed maps depict if in a molecular region the atomic contributions are important, modest or negligible. Besides, they may also be useful for a proper selection of the reference points and for a full understanding of the source function percentages analysis. In fact, the choice of the reference point where to reconstruct the studied density is neither easy nor objective for non-standard situations, such as for the spin density. This novel application was applied to the study of the spin density on a couple of azido Cu complexes. The source function partial reconstructed maps allow to unravel the different role played by the paramagnetic centre Cu and the ligand atoms and to explain the spin transmission mechanism at a molecular level. Moreover, they enable to highlight the nature of the spin density differences between the two complexes and among adopted computational approaches. DFT functionals tend to over-delocalise the spin density towards the ligand atoms introducing a biased spin-polarization mechanism between the Cu and the ligand atoms. The same descriptor was then applied to the study of the hydrogen bonds in the DNA base pairs. The source function reveals the delocalised nature of these interactions, highlighting that distant groups and rings have non-negligible effects on the reconstruction of the electron density in the intermolecular region. Besides, the analysis demonstrates that the purine and pyrimidine bases equally contribute to the reconstruction of the electron density at the hydrogen bond critical points. The source function also reveals that subtle variations of the atomic source contributions occur when the pairs are ionized, revealing that sources and sinks effects redistribution plays an important role in the stabilization of the DNA base pairs. The source function was also used to develop a method to extract full population matrices purely based on the electron density distribution and then amenable to experimental determination. The peculiar features of this descriptor, in particular the cause-effect relationship, assign a profound chemical meaning to the matrix elements in contrast with other population analyses such as the Mulliken's one, where the matrix elements are associated to orbital overlaps. The latest breakthroughs on the development of this method are shown together with some numerical examples on very simple compounds. The full population matrices obtained using the source function descriptor are able to retrieve the major chemical features. A detailed analysis on the intermolecular interactions involved in the in vivo molecular recognition of the antimalarial drug chloroquine with the heme moiety has been carried out using a combined topological-energetic analysis. This work reveals that charged-assisted hydrogen bonds set up between the lateral chains of the chloroquine and the propionate group of the heme are the most important interactions in the drug:substrate recognition process.
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7

Calabrese, Pasquale. "Critical Behavior of Systems with Complex Symmetries." Doctoral thesis, Scuola Normale Superiore, 2005. http://hdl.handle.net/11384/85862.

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Del, Ferraro Gino. "Equilibrium and Dynamics on Complex Networkds." Doctoral thesis, KTH, Beräkningsvetenskap och beräkningsteknik (CST), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191991.

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Complex networks are an important class of models used to describe the behaviour of a very broad category of systems which appear in different fields of science ranging from physics, biology and statistics to computer science and other disciplines. This set of models includes spin systems on a graph, neural networks, decision networks, spreading disease, financial trade, social networks and all systems which can be represented as interacting agents on some sort of graph architecture. In this thesis, by using the theoretical framework of statistical mechanics, the equilibrium and the dynamical behaviour of such systems is studied. For the equilibrium case, after presenting the region graph free energy approximation, the Survey Propagation method, previously used to investi- gate the low temperature phase of complex systems on tree-like topologies, is extended to the case of loopy graph architectures. For time-dependent behaviour, both discrete-time and continuous-time dynamics are considered. It is shown how to extend the cavity method ap- proach from a tool used to study equilibrium properties of complex systems to the discrete-time dynamical scenario. A closure scheme of the dynamic message-passing equation based on a Markovian approximations is presented. This allows to estimate non-equilibrium marginals of spin models on a graph with reversible dynamics. As an alternative to this approach, an extension of region graph variational free energy approximations to the non-equilibrium case is also presented. Non-equilibrium functionals that, when minimized with constraints, lead to approximate equations for out-of-equilibrium marginals of general spin models are introduced and discussed. For the continuous-time dynamics a novel approach that extends the cav- ity method also to this case is discussed. The main result of this part is a Cavity Master Equation which, together with an approximate version of the Master Equation, constitutes a closure scheme to estimate non-equilibrium marginals of continuous-time spin models. The investigation of dynamics of spin systems is concluded by applying a quasi-equilibrium approach to a sim- ple case. A way to test self-consistently the assumptions of the method as well as its limits is discussed. In the final part of the thesis, analogies and differences between the graph- ical model approaches discussed in the manuscript and causal analysis in statistics are presented.

QC 20160904

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Mantovani, Rocco. "Modelling complex systems in the severely undersampled regime: a Bayesian model selection approach." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18019/.

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Анотація:
L'inferenza di modelli di spin è uno strumento diffuso nell'approccio statistico ai sistemi complessi. Tipicamente ci si limita a modelli con interazioni a uno e due corpi: per il principio di massima entropia, ciò equivale ad assumere che magnetizzazioni e correlazioni a coppie costituiscano le variabili rilevanti (statistiche sufficienti) del sistema. L'assunzione non è giustificabile nel caso generale sulla base di argomenti puramente statistici; il problema della selezione tra modelli con interazioni di ordine arbitrario è però alto-dimensionale. Esso può essere affrontato tramite una particolare euristica Bayesiana che permette di ottenere le variabili rilevanti direttamente dal campione; la selezione avviene nella classe delle misture, e i risultati vengono proiettati sulla rappresentazione di spin. Il risultato è l'ottenimento delle statistiche sufficienti senza alcuna assunzione a priori. Il numero di tali statistiche è modulato da quello di differenti frequenze empiriche nel campione; in regime di sottocampionamento, esso è molto minore della dimensione del modello completo. Ciò rende il problema di inferenza dei parametri tipicamente basso-dimensionale. Il principale scopo di questo lavoro è quello di investigare esplicitamente come l'informazione sia organizzata nella mappa tra misture e modelli di spin. La comprensione dettagliata di tale mappa suggerisce nuovi approcci per la regolarizzazione; inoltre i risultati gettano luce sulla natura delle statistiche sufficienti, che risultano essere funzioni degli stati solo tramite le frequenze empiriche di questi. Mostriamo come da un approccio integralmente Bayesiano emerga sotto opportune condizioni un termine regolarizzatore "L2"; verifichiamo numericamente se tali condizioni sono tipicamente soddisfatte. Presentiamo infine alcune osservazioni qualitative circa l'emersione di loop stuctures nella mappa da misture a spin; queste aprono scenari interessanti per la ricerca futura.
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Weber, Josef Andreas [Verfasser], Christoph Pascal [Akademischer Betreuer] [Gutachter] Hugenschmidt, Rudolf [Gutachter] Gross, and Claudia [Gutachter] Felser. "Spin-Polarized Positron Annihilation Spectroscopy : Investigation of Complex Metallic Systems / Josef Andreas Weber ; Gutachter: Rudolf Gross, Claudia Felser, Christoph Pascal Hugenschmidt ; Betreuer: Christoph Pascal Hugenschmidt." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/112881935X/34.

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Книги з теми "Complex spin systems"

1

Newman, Charles M. (Charles Michael), 1946-, ed. Primers in complex systems. Princeton: Princeton University Press, 2013.

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2

Steven, Tomsovic, ed. Tunneling in complex systems. Singapore: World Scientific, 1998.

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3

Lechner, Barbara A. J. Studying Complex Surface Dynamical Systems Using Helium-3 Spin-Echo Spectroscopy. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-01180-6.

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4

NATO Advanced Research Workshop on Relaxation in Complex Systems and Related Topics (1989 Turin, Italy). Relaxation in complex systems and related topics. New York: Plenum Press, 1990.

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International, Conference on Complex Systems: Fractals Spin Glasses and Neural Networks (1991 Trieste Italy). Complex systems: Fractals, spin glasses and neural networks : proceedings of the International Conference on Complex Systems: Fractals, Spin Glasses and Neural Networks I.C.T.P., Trieste, Italy, 2-6 July 1991. Amsterdam: North-Holland, 1992.

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6

Suwa, Hidemaro. Geometrically Constructed Markov Chain Monte Carlo Study of Quantum Spin-phonon Complex Systems. Tokyo: Springer Japan, 2014. http://dx.doi.org/10.1007/978-4-431-54517-0.

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7

M, Rubí J., and Pérez-Vicente Conrado 1962-, eds. Complex behaviour of glassy systems: Proceedings of the XIV Sitges conference, Sitges, Barcelona, Spain, 10-14 June 1996. Berlin: Springer, 1997.

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8

Yukawa International Symposium (2nd 1988 Kyoto, Japan). Cooperative dynamics in complex physical systems: Proceedings of the Second Yukawa International Symposium, Kyoto, Japan, August 24-27, 1988. Berlin: Springer-Verlag, 1989.

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9

Zoltán, Gingl, Society of Photo-optical Instrumentation Engineers., and Sociedad Española de Optica, eds. Noise in complex systems and stochastic dynamics II: 26-28 May, 2004, Maspalomas, Gran Canaria, Spain. Bellingham, Wash: SPIE, 2004.

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10

S, Wio Horacio, Rodríguez M. A, and Pesquera L, eds. Complex systems: New trends and expectations : selected and refereed papers from the Workshop on Complex Systems, Santander, Spain, 5-9 June 2006. Les Ulis, France: EDP Sciences, 2007.

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Більше джерел

Частини книг з теми "Complex spin systems"

1

In, Visarath, and Antonio Palacios. "Spin Torque Nano Oscillators." In Understanding Complex Systems, 317–37. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-55545-3_9.

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2

Maesato, Mitsuhiko. "Recent Topics on Organic Spin Liquid Candidates." In Creative Complex Systems, 231–45. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-4457-3_15.

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3

Subash, B., V. K. Chandrasekar, and M. Lakshmanan. "Nonlinear Dynamics of an Array of Nano Spin Transfer Oscillators." In Understanding Complex Systems, 25–38. Cham: Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-02925-2_3.

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4

Sturgis-Jensen, Brian, Antonio Palacios, Patrick Longhini, and Visarath In. "Bifurcation Analysis of Spin-Torque Nano Oscillators Parallel Array Configuration." In Understanding Complex Systems, 300–309. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-10892-2_31.

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5

Turtle, J., A. Palacios, V. In, and P. Longhini. "The Dynamics of Coupled Spin-Torque Nano Oscillators: An Initial Exploration." In Understanding Complex Systems, 285–91. Cham: Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-02925-2_25.

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6

Yoshimura, Kazuyoshi. "Itinerant-Electron Magnetism and Spin Fluctuations—Aspects of Theories and Experiments." In Creative Complex Systems, 189–213. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-4457-3_13.

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7

Lundgren, Leif. "Experiments on Spin Glass Dynamics." In Relaxation in Complex Systems and Related Topics, 3–10. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4899-2136-9_1.

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8

Suwa, Hidemaro. "Multi-Chain Spin-Peierls Systems." In Geometrically Constructed Markov Chain Monte Carlo Study of Quantum Spin-phonon Complex Systems, 107–17. Tokyo: Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54517-0_6.

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9

Stein, Daniel L. "Spin Glasses: Still Complex after All These Years?" In Decoherence and Entropy in Complex Systems, 349–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-40968-7_25.

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10

Kinzel, W. "Spin Glasses as Model Systems for Neural Networks." In Complex Systems — Operational Approaches in Neurobiology, Physics, and Computers, 107–15. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-70795-7_7.

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Тези доповідей конференцій з теми "Complex spin systems"

1

Mayer, P. "Exact Non-Equilibrium Fluctuation Dissipation Relations for Multi-Spin Observables in the Glauber-Ising Spin Chain." In SLOW DYNAMICS IN COMPLEX SYSTEMS: 3rd International Symposium on Slow Dynamics in Complex Systems. AIP, 2004. http://dx.doi.org/10.1063/1.1764270.

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2

Garrahan, Juan P. "Glassy dynamics of a two-dimensional non-disordered spin model." In Disordered and complex systems. AIP, 2001. http://dx.doi.org/10.1063/1.1358159.

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3

Affouard, F. "Molecular Dynamics simulations and Neutron Spin Echo experiments of difluorotetrachloroethane glassy crystal." In SLOW DYNAMICS IN COMPLEX SYSTEMS: 3rd International Symposium on Slow Dynamics in Complex Systems. AIP, 2004. http://dx.doi.org/10.1063/1.1764245.

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4

Sawada, Isao. "Ground-State Memories Survive Strenuous Thermal Fluctuations: Dynamics of Dimerized Spin Chains." In SLOW DYNAMICS IN COMPLEX SYSTEMS: 3rd International Symposium on Slow Dynamics in Complex Systems. AIP, 2004. http://dx.doi.org/10.1063/1.1764269.

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5

Nishimori, Hidetoshi. "Absence of replica symmetry breaking in a region of the phase diagram of the Ising spin glass." In Disordered and complex systems. AIP, 2001. http://dx.doi.org/10.1063/1.1358165.

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6

Sasaki, M. "Effects of temperature chaos on rejuvenation and memory in Migdal-Kadanoff spin glasses." In SLOW DYNAMICS IN COMPLEX SYSTEMS: 3rd International Symposium on Slow Dynamics in Complex Systems. AIP, 2004. http://dx.doi.org/10.1063/1.1764190.

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7

Schneider, Johannes J. "Searching for Backbones — An Efficient Parallel Algorithm for Finding Groundstates in Spin Glass Models." In SLOW DYNAMICS IN COMPLEX SYSTEMS: 3rd International Symposium on Slow Dynamics in Complex Systems. AIP, 2004. http://dx.doi.org/10.1063/1.1764191.

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8

Takeda, T. "Neutron Spin Echo Study on Slow Dynamics of Lipid Bilayers in the DPPC/D2O/CaCl2 System." In SLOW DYNAMICS IN COMPLEX SYSTEMS: 3rd International Symposium on Slow Dynamics in Complex Systems. AIP, 2004. http://dx.doi.org/10.1063/1.1764082.

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9

Okada, M., and T. Toyoda. "Exact relations for the spin correlation functions." In The 8th tohwa university international symposium on slow dynamics in complex systems. AIP, 1999. http://dx.doi.org/10.1063/1.58573.

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10

Meyer, Jan Christian, and Anne Cathrine Elster. "Latency Impact on Spin-Lock Algorithms for Modern Shared Memory Multiprocessors." In 2008 International Conference on Complex, Intelligent and Software Intensive Systems. IEEE, 2008. http://dx.doi.org/10.1109/cisis.2008.132.

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Звіти організацій з теми "Complex spin systems"

1

Decroux, Agnes, Kassem Kalo, and Keith Swinden. PR-393-205100-R01 IRIS X-Ray CT Qualification for Flexible Pipe Inspection (Phase 1). Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2021. http://dx.doi.org/10.55274/r0012068.

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Анотація:
There are several techniques available to inspect single wall carbon steel pipelines including; Magnetic flux leakage (MFL), ultrasonic testing (UT), Electro-Magnetic Acoustic Transducer (EMAT), Phased Array, guide wave testing (GWT), etc. However, for more complex structures such as flexible pipelines the technology available to inspect them is far more limited. PRCI commissioned a program (SPIM 2-1) under the Subsea TC (2017-2020) to evaluate all known and suspected technologies that could be used to provide a detailed subsea inspection of a flexible riser. PRCI produced four samples of flexible pipe containing pre-manufactured cracks and corrosion defects which were located in; the outer armour layer, inner armour layer, pressure vault and carcass. The samples were used for blind testing of all identified inspection technologies. On conclusion of the SPIM 2-1 program, HR-XCT was identified as the technology showing the most promise and a follow-on program (SPIM 2-2) was commissioned to further explore the capabilities. This report will show the way in which high resolution image clarity and image manipulation was extracted from the HR-XCT system when used on the PRCI flexible pipe samples. The XCT results from SPIM 2-2 will be presented to show the initial setup of the experiment and 2D and 3D high resolution sectioned images from the testing. These images clearly identify and characterize 100% of the pre-manufactured defects introduced into the samples in all layers.
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2

Kahima, Samuel, Solomon Rukundo, and Victor Phillip Makmot. Tax Certainty? The Private Rulings Regime in Uganda in Comparative Perspective. Institute of Development Studies, January 2021. http://dx.doi.org/10.19088/ictd.2021.001.

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Анотація:
Taxpayers sometimes engage in complex transactions with uncertain tax treatment, such as mergers, acquisitions, demergers and spin-offs. With the rise of global value chains and proliferation of multinational corporations, these transactions increasingly involve transnational financial arrangements and cross-border dealings, making tax treatment even more uncertain. If improperly structured, such transactions could have costly tax consequences. One approach to dealing with this uncertainty is to create a private rulings regime, whereby a taxpayer applies for a private ruling by submitting a statement detailing the transaction (proposed or completed) to the tax authority. The tax authority interprets and applies the tax laws to the requesting taxpayer’s specific set of facts in a written private ruling. The private ruling offers taxpayers certainty as to how the tax authority views the transaction, and the tax treatment the taxpayer can expect based on the specific facts presented. Private rulings are a common feature of many tax systems around the world, and their main goal is to promote tax certainty and increase investor confidence in the tax system. This is especially important in a developing country like Uganda, whose tax laws are often amended and may not anticipate emerging transnational tax issues. Private rulings in Uganda may be applied for in writing prior to or after engaging in the transaction. The Tax Procedures Code Act (TPCA), which provides for private rulings, requires applicants to make a full and true disclosure of the transaction before a private ruling may be issued. This paper evaluates the Ugandan private rulings regime, offering a comparative perspective by highlighting similarities and contrasts between the Ugandan regime and that of other jurisdictions, including the United States, Australia, South Africa and Kenya. The Ugandan private rulings regime has a number of strengths. It is not just an administrative measure as in some jurisdictions, but is based on statute. Rulings are issued from a central office – instead of different district offices, which may result in conflicting rulings. Rather than an elaborate appeals process, the private ruling is only binding on the URA and not on the taxpayer, so a dissatisfied taxpayer can simply ignore the ruling. The URA team that handles private rulings has diverse professional backgrounds, which allows for a better understanding of applications. There are, however, a number of limitations of the Ugandan private rulings system. The procedure of revocation of a private ruling is uncertain. Private rulings are not published, which makes them a form of ‘secret law’. There is no fee for private rulings, which contributes to a delay in the process of issuing one. There is understaffing in the unit that handles private rulings. Finally, there remains a very high risk of bias against the taxpayer because the unit is answerable to a Commissioner whose chief mandate is collection of revenue. A reform of the private rulings regime is therefore necessary, and this would include clarifying the circumstances under which revocation may occur, introducing an application fee, increasing the staffing of the unit responsible, and placing the unit under a Commissioner who does not have a collection mandate. While the private rulings regime in Uganda has shortcomings, it remains an essential tool in supporting investor confidence in the tax regime.
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3

Whitecloud, Simone, Holly VerMeulen, Franz Lichtner, Nadia Podpora, Timothy Cooke, Christopher Williams, Michael Musty, Irene MacAllister, and Jason Dorvee. Understanding plant volatiles for environmental awareness : chemical composition in response to natural light cycles and wounding. Engineer Research and Development Center (U.S.), November 2022. http://dx.doi.org/10.21079/11681/45961.

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Plants emit a bouquet of volatile organic compounds (VOCs) in response to both biotic and abiotic stresses and, simultaneously, eavesdrop on emit-ted signals to activate direct and indirect defenses. By gaining even a slight insight into the semantics of interplant communications, a unique aware-ness of the operational environment may be obtainable (e.g., knowledge of a disturbance within). In this effort, we used five species of plants, Arabidopsis thaliana, Panicum virgatum, Festuca rubra, Tradescantia zebrina, and Achillea millefolium, to produce and query VOCs emitted in response to mechanical wounding and light cycles. These plants provide a basis for further investigation in this communication system as they span model organisms, common house plants, and Arctic plants. The VOC com-position was complex; our parameter filtering often enabled us to reduce the noise to fewer than 50 compounds emitted over minutes to hours in a day. We were able to detect and measure the plant response through two analytical methods. This report documents the methods used, the data collected, and the analyses performed on the VOCs to determine if they can be used to increase environmental awareness of the battlespace.
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4

Lewis, Dustin. Three Pathways to Secure Greater Respect for International Law concerning War Algorithms. Harvard Law School Program on International Law and Armed Conflict, 2020. http://dx.doi.org/10.54813/wwxn5790.

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Анотація:
Existing and emerging applications of artificial intelligence in armed conflicts and other systems reliant upon war algorithms and data span diverse areas. Natural persons may increasingly depend upon these technologies in decisions and activities related to killing combatants, destroying enemy installations, detaining adversaries, protecting civilians, undertaking missions at sea, conferring legal advice, and configuring logistics. In intergovernmental debates on autonomous weapons, a normative impasse appears to have emerged. Some countries assert that existing law suffices, while several others call for new rules. Meanwhile, the vast majority of efforts by States to address relevant systems focus by and large on weapons, means, and methods of warfare. Partly as a result, the broad spectrum of other far-reaching applications is rarely brought into view. One normatively grounded way to help identify and address relevant issues is to elaborate pathways that States, international organizations, non-state parties to armed conflict, and others may pursue to help secure greater respect for international law. In this commentary, I elaborate on three such pathways: forming and publicly expressing positions on key legal issues, taking measures relative to their own conduct, and taking steps relative to the behavior of others. None of these pathways is sufficient in itself, and there are no doubt many others that ought to be pursued. But each of the identified tracks is arguably necessary to ensure that international law is — or becomes — fit for purpose. By forming and publicly expressing positions on relevant legal issues, international actors may help clarify existing legal parameters, pinpoint salient enduring and emerging issues, and detect areas of convergence and divergence. Elaborating legal views may also help foster greater trust among current and potential adversaries. To be sure, in recent years, States have already fashioned hundreds of statements on autonomous weapons. Yet positions on other application areas are much more difficult to find. Further, forming and publicly expressing views on legal issues that span thematic and functional areas arguably may help States and others overcome the current normative stalemate on autonomous weapons. Doing so may also help identify — and allocate due attention and resources to — additional salient thematic and functional areas. Therefore, I raise a handful of cross-domain issues for consideration. These issues touch on things like exercising human agency, reposing legally mandated evaluative decisions in natural persons, and committing to engage only in scrutable conduct. International actors may also take measures relative to their own conduct. To help illustrate this pathway, I outline several such existing measures. In doing so, I invite readers to inventory and peruse these types of steps in order to assess whether the nature or character of increasingly complex socio-technical systems reliant upon war algorithms and data may warrant revitalized commitments or adjustments to existing measures — or, perhaps, development of new ones. I outline things like enacting legislation necessary to prosecute alleged perpetrators of grave breaches, making legal advisers available to the armed forces, and taking steps to prevent abuses of the emblem. Finally, international actors may take measures relative to the conduct of others. To help illustrate this pathway, I outline some of the existing steps that other States, international organizations, and non-state parties may take to help secure respect for the law by those undertaking the conduct. These measures may include things like addressing matters of legal compliance by exerting diplomatic pressure, resorting to penal sanctions to repress violations, conditioning or refusing arms transfers, and monitoring the fate of transferred detainees. Concerning military partnerships in particular, I highlight steps such as conditioning joint operations on a partner’s compliance with the law, planning operations jointly in order to prevent violations, and opting out of specific operations if there is an expectation that the operations would violate applicable law. Some themes and commitments cut across these three pathways. Arguably, respect for the law turns in no small part on whether natural persons can and will foresee, understand, administer, and trace the components, behaviors, and effects of relevant systems. It may be advisable, moreover, to institute ongoing cross-disciplinary education and training as well as the provision of sufficient technical facilities for all relevant actors, from commanders to legal advisers to prosecutors to judges. Further, it may be prudent to establish ongoing monitoring of others’ technical capabilities. Finally, it may be warranted for relevant international actors to pledge to engage, and to call upon others to engage, only in armed-conflict-related conduct that is sufficiently attributable, discernable, and scrutable.
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5

Hulata, Gideon, Thomas D. Kocher, and Micha Ron. Elucidating the molecular pathway of sex determination in cultured Tilapias and use of genetic markers for creating monosex populations. United States Department of Agriculture, January 2007. http://dx.doi.org/10.32747/2007.7695855.bard.

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The objectives of this project were to: 1) Identify genetic markers linked to sex-determining genes in various experimental and commercial stocks of O. niloticusand O. aureus, as well as red tilapias; 2) Develop additional markers tightly linked to these sex determiners, and develop practical, non-destructive genetic tests for identifying genotypic sex in young tilapia; A third aim, to map sex modifier loci, was removed during budget negotiations at the start of the project. Background to the topic. A major obstacle to profitable farming of tilapia is the tendency of females to reproduce at a small size during the production cycle, diverting feed and other resources to a large population of small, unmarketable fish. Several approaches for producing all-male fingerlings have been tried, including interspecific hybridization, hormonal masculinization, and the use of YY-supermale broodstock. Each method has disadvantages that could be overcome with a better understanding of the genetic basis of sex determination in tilapia. The lack of sex-linked markers has been a major impediment in research and development of efficient monosex populations for tilapia culture. Major conclusions, solutions, achievements. We identified DNA markers linked to sex determining genes in six closely related species of tilapiine fishes. The mode of sex determination differed among species. In Oreochromis karongaeand Tilapia mariaethe sex-determining locus is on linkage group (LG) 3 and the female is heterogametic (WZ-ZZ system). In O. niloticusand T. zilliithe sex-determining locus is on LG1 and the male is heterogametic (XX-XY system). We have nearly identified the series of BAC clones that completely span the region. A more complex pattern was observed in O. aureus and O. mossambicus, in which markers on both LG1 and LG3 were associated with sex. We found evidence for sex-linked lethal effects on LG1, as well as interactions between loci in the two linkage groups. Comparison of genetic and physical maps demonstrated a broad region of recombination suppression harboring the sex-determining locus on LG3. We also mapped 29 genes that are considered putative regulators of sex determination. Amhand Dmrta2 mapped to separate QTL for sex determination on LG23. The other 27 genes mapped to various linkage groups, but none of them mapped to QTL for sex determination, so they were excluded as candidates for sex determination in these tilapia species. Implications, both scientific and agricultural. Phylogenetic analysis suggests that at least two transitions in the mode of sex determination have occurred in the evolution of tilapia species. This variation makes tilapias an excellent model system for studying the evolution of sex chromosomes in vertebrates. The genetic markers we have identified on LG1 in O. niloticusaccurately diagnose the phenotypic sex and are being used to develop monosex populations of tilapia, and eliminate the tedious steps of progeny testing to verify the genetic sex of broodstock animals.
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6

Taucher, Jan, and Markus Schartau. Report on parameterizing seasonal response patterns in primary- and net community production to ocean alkalinization. OceanNETs, November 2021. http://dx.doi.org/10.3289/oceannets_d5.2.

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We applied a 1-D plankton ecosystem-biogeochemical model to assess the impacts of ocean alkalinity enhancement (OAE) on seasonal changes in biogeochemistry and plankton dynamics. Depending on deployment scenarios, OAE should theoretically have variable effects on pH and seawater pCO2, which might in turn affect (a) plankton growth conditions and (b) the efficiency of carbon dioxide removal (CDR) via OAE. Thus, a major focus of our work is how different magnitudes and temporal frequencies of OAE might affect seasonal response patterns of net primary productivity (NPP), ecosystem functioning and biogeochemical cycling. With our study we aimed at identifying a parameterization of how magnitude and frequency of OAE affect net growth rates, so that these effects could be employed for Earth System Modell applications. So far we learned that a meaningful response parameterization has to resolve positive and negative anomalies that covary with temporal shifts. As to the intricacy of the response patterns, the derivation of such parameterization is work in progress. However, our study readily provides valuable insights to how OAE can alter plankton dynamics and biogeochemistry. Our modelling study first focuses at a local site where time series data are available (European Station for Time series in the Ocean Canary Islands ESTOC), including measurements of pH, concentrations of total alkalinity, dissolved inorganic carbon (DIC), chlorophyll-a and dissolved inorganic nitrogen (DIN). These observational data were made available by Andres Cianca (personal communication, PLOCAN, Spain), Melchor Gonzalez and Magdalena Santana Casiano (personal communication, Universidad de Las Palmas de Gran Canaria). The choice of this location was underpinned by the fact that the first OAE mesocosm experiment was conducted on the Canary Island Gran Canaria, which will facilitate synthesizing our modelling approach with experimental findings. For our simulations at the ESTOC site in the Subtropical North Atlantic we found distinct, non-linear responses of NPP to different temporal modes of alkalinity deployment. In particular, phytoplankton bloom patterns displayed pronounced temporal phase shifts and changes in their amplitude. Notably, our simulations suggest that OAE can have a slightly stimulating effect on NPP, which is however variable, depending on the magnitude of OAE and the temporal mode of alkalinity addition. Furthermore, we find that increasing alkalinity perturbations can lead to a shift in phytoplankton community composition (towards coccolithophores), which even persists after OAE has stopped. In terms of CDR, we found that a decrease in efficiency with increasing magnitude of alkalinity addition, as well as substantial differences related to the timing of addition. Altogether, our results suggest that annual OAE during the right season (i.e. physical and biological conditions), could be a reasonable compromise in terms of logistical feasibility, efficiency of CDR and side-effects on marine biota. With respect to transferability to global models, the complex, non-linear responses of biological processes to OAE identified in our simulations do not allow for simple parameterizations that can easily adapted. Dedicated future work is required to transfer the observed responses at small spatiotemporal scales to the coarser resolution of global models.
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