On classification of finite commutative chain rings

<abstract><p>Let $ R $ be a finite commutative chain ring with invariants $ p, n, r, k, m. $ It is known that $ R $ is an extension over a Galois ring $ GR(p^n, r) $ by an Eisenstein polynomial of some degree $ k $. If $ p\nmid k, $ the enumeration of such rings is known. However, when $ p\mid k $, relatively little is known about the classification of these rings. The main purpose of this article is to investigate the classification of all finite commutative chain rings with given invariants $ p, n, r, k, m $ up to isomorphism when $ p\mid k. $ Based on the notion of j-diagram initiated by Ayoub, the number of isomorphism classes of finite (complete) chain rings with $ (p-1)\nmid k $ is determined. In addition, we study the case $ (p-1)\mid k, $ and show that the classification is strongly dependent on Eisenstein polynomials not only on $ p, n, r, k, m. $ In this case, we classify finite (incomplete) chain rings under some conditions concerning the Eisenstein polynomials. These results yield immediate corollaries for p-adic fields, coding theory and geometry.</p></abstract>

A simulation chain for reflectometry and non-linear MHD: type-I ELM case

A complete chain from a non-linear MHD plasma model simulation through full-wave code simulations implementing synthetic conventional reflectometry is established. For this purpose, the two-dimensional full-wave code REFMUL is employed together with MHD descriptions obtained from the JOREK code. First results of the integrated modeling are presented here where a type-I ELM crash, leading to a fast collapse of the H-mode pedestal, was taken as case-study. The REFMUL simulations were customized to implement synthetic reflectometry in conventional set-up using fixed frequency probing with O-mode waves. Posing challenging conditions for reflectometry, the type-I ELM crash reveals some of the merits and caveats of the diagnostic technique. This work also opens up the possibility to extend modeling to other MHD or ELM studies and provide support to experimental observations with reflectometry.

Whole animal modelling reveals neuronal mechanisms of decision-making and reproduces unpredictable swimming in frog tadpoles

Animal behaviour is based on interaction between nervous, musculoskeletal and environmental systems. How does an animal process sensory stimuli, use it to decide whether and how to respond, and initiate the locomotor behaviour? We build the whole body computer models of a simple vertebrate with a complete chain of neural circuits and body units for sensory information processing, decision-making, generation of spiking activities, muscle innervation, body flexion, body-water interaction, and movement. Our Central Nervous System (CNS) model generates biologically-realistic spiking and reveals that sensory memory populations on two hindbrain sides compete for swimming initiation and first body flexion. Biomechanical 3-dimensional "Virtual Tadpole" (VT) model is constructed to evaluate if motor outputs of CNS model can produce swimming-like movements in a volume of "water". We find that whole animal modelling generates reliable and realistic swimming. The combination of CNS and VT models opens a new perspective for experiments with immobilised tadpoles.

Quantification of the Direct Solar Impact on Some Components of the Hydro-Climatic System

This study addresses the causal links between external factors and the main hydro-climatic variables by using a chain of methods to unravel the complexity of the direct sun–climate link. There is a gap in the literature on the description of a complete chain in addressing the structures of direct causal links of solar activity on terrestrial variables. This is why the present study uses the extensive facilities of the application of information theory in view of recent advances in different fields. Additionally, by other methods (e.g., neural networks) we first tested the existent non-linear links of solar–terrestrial influences on the hydro-climate system. The results related to the solar impact on terrestrial phenomena are promising, which is discriminant in the space-time domain. The implications prove robust for determining the causal measure of climate variables under direct solar impact, which makes it easier to consider solar activity in climate models by appropriate parametrizations. This study found that hydro-climatic variables are sensitive to solar impact only for certain frequencies (periods) and have a coherence with the Solar Flux only for some lags of the Solar Flux (in advance).

Quantification of the Direct Solar Impact on Some Components of the Hydroclimatic System

This study addresses the causal links between external factors and the main hydro-climatic variables. There is a gap in the literature on the description of a complete chain in addressing the structures of direct causal links of solar activity on the terrestrial variables. This is why, the present study uses the extensive facilities of the application of information theory in view of recent advances in different fields. Also, by other methods (e.g. neural networks) first are tested the existence non-linear links of solar-terrestrial influences on hydro-climate system. The results are promising related to the solar impact on terrestrial phenomena which is discriminant in space-time domain. The implications prove robust for determining the causal measure of climate variables under direct solar impact which makes it easier to consider solar activity in climate models, by appropriate parametrizations. This study found that hydro-climatic variables are sensitive to solar impact only for certain frequencies (periods) and these have a coherence with the Solar-Flux only for some lags of the Solar-Flux (in advance).

Taking into account the non-proportional loading effect on high cycle fatigue life predictions obtained by invariant-based approaches

Industrial structures are often subjected to multiaxial fatigue loadings. If the multiple stress signals are not synced the loading is said to be non-proportional. Most of the multiaxial fatigue criteria give highly inaccurate lifetime predictions when used in the case of such loadings. The scalar equivalent stress defined by the criteria does not take into account the non-proportional nature of the multiaxial loading and leads to non-conservative predictions. Moreover a multiaxial fatigue criterion can only be applied on a stress cycle which has no clear definition when multiple unsynced signals are to be considered. This study addresses these issues by proposing a correction of an invariant based multiaxial fatigue criterion through the definition of a non-proportional degree indicator. A definition of multiaxial cycle is also given based on the Wang-Brown method. Finally a complete chain of invariant based lifetime prediction for non-proportional multiaxial fatigue is validated.

A Bistable Mechanism Mediated by Integrins Controls Mechanotaxis of Leukocytes

The recruitment of leukocytes from blood vessels to inflamed zones is guided by biochemical and mechanical stimuli, with mechanisms only partially deciphered. We studied here the guidance by flow of primary human effector T lymphocytes crawling on substrates coated with ligands of integrins LFA-1 (αLβ2) and VLA-4 (α4β1), and showed that cells segregated in two populations of opposite orientation for combined adhesion. Sharp decisions of orientation were shown to rely on a bistable mechanism between LFA-1-mediated upstream and VLA-4-dominant downstream phenotypes. At the molecular level, bistability results from a differential front-rear polarization of both integrins affinity, combined with an inhibiting crosstalk of LFA-1 toward VLA-4. At the cellular level, directivity with or against the flow is mechanically mediated by the passive orientation of detached uropod or lamellipod by flow. This complete chain of logical events provides a unique mechanistic picture of a guiding mechanism, from stimuli to cell orientation.SignificanceCellular guidance is crucial to many biological functions, but the precise mechanisms remain unclear. We have analyzed here an original phenotype of flow-guided cells mimicking leukocytes crawling into the blood vessels and showed that thecontrolling parameterof cells decision to migrate upstream or downstream was therelative numberof two specific adhesion molecules, the integrins LFA-1 and VLA-4. The spatial polarisation of integrins affinity and an intermutually feedback of their activation create a bistable system where cells adhere either by their tip or their tail and orient respectively downstream or upstream. This mechanism therefore proposes a complete chain of event from stimuli to cell orientation and differs strongly from the chemotaxis paradigm because stimuli trigger no signaling.

SUSD3D Computer Code as Part of the XSUN-2017 Windows Interface Environment for Deterministic Radiation Transport and Cross-Section Sensitivity-Uncertainty Analysis

A Windows interface XSUN-2017 facilitating the deterministic radiation transport and cross-section sensitivity-uncertainty (S/U) calculation is presented. The package was developed to assist the users in the preparation of input cards, rapid modification, and execution of the complete chain of codes including TRANSX, PARTISN, and SUSD3D, all available from the OECD/NEA Data Bank and RSICC. The objective of this work was to make the input and output handling for these codes as user-friendly as possible, passing information among codes internally. XSUN-2017 allows a user-friendly viewing of results obtained from the PARTISN and SUSD3D programs. The first version of the Windows interface XSUN-2013 was developed in 2013 and submitted to OECD/NEA Data Bank Computer Code Collection and RSICC in early 2014. An updated version, XSUN-2017, will be released in 2017. The package includes also the new version of the SUSD3D code. The XSUN-2017 and SUSD3D code systems and recent improvements and updates are described. Examples of the use and validation are presented, including the S/U intercomparison exercise using the SNEAK-7 benchmarks involving the XSUN-2017 code system comparison with the codes such as TSUNAMI, SERPENT, and MCNP6, and the S/U analysis of the keff and βeff parameters for the MYRRHA accelerator driven system (ADS).