Ice-rich (periglacial) vs icy (glacial) depressions in the Argyre region, Mars: a proposed cold-climate dichotomy of landforms

On Mars, so-called “scalloped depressions” are widely observed in Utopia Planitia (UP) and Malea Planum (MP). Typically, they are rimless, metres- to decametres-deep, incised sharply, tiered inwardly, polygonised and sometimes pitted. The depressions seemingly incise terrain that is icy and possibly thermokarstic, i.e. produced by the thermal destabilisation of the icy terrain. Agewise, the depressions are thought to be relatively youthful, originating in the Late Amazonian Epoch.Here, we report the presence of similar depressions in the Argyre region (AR) (30–60° S; 290–355° E). More importantly, we separate and differentiate these landforms into two groups: (ice-rich) periglacial depressions (Type-1); and, (icy) glacial depressions (Type-2a-c). This differentiation is presented to the Mars community for the first time.Based on a suite of morphological and geological characteristics synonymous with ice-complexes in the Lena Peninsula (eastern Russia) and the Tuktoyaktuk Coastlands (Northwest Territories, Canada), we propose that the Type-1 depressions are ice-rich periglacial basins that have undergone volatile depletion largely by sublimation and as the result of thermal destabilisation. In keeping with the terms and associated definitions derived of terrestrial periglacial-geomorphology, ice-rich refers to permanently frozen-ground in which ice lenses or segregation ice (collectively referenced as excess ice) have formed.We suggest that the depressions are the product of a multi-step, cold-climate geochronology:(1) Atmospheric precipitation and surface accumulation of an icy mantle during recent high obliquities.(2) Regional or local triple-point conditions and thaw/evaporation of the mantle, either by exogenic forcing, i.e. obliquity-driven rises of aerial and sub-aerial temperatures, or endogenic forcing, i.e. along Argyre impact-related basement structures.(3) Meltwater migration into the regolith, at least to the full depth of the depressions.(4) Freeze-thaw cycling and the formation of excess ice.(5) Sublimation of the excess ice and depression formation as high obliquity dissipates and near-surface ice becomes unstable.The Type-2 depressions exhibit characteristics suggestive of (supra-glacial) dead-ice basins and snow/ice suncups observed in high-alpine landscapes on Earth, e.g. the Swiss Alps and the Himalayas. Like the Type-1 depressions, the Type-2 depressions could be the work of sublimation; however, the latter differ from the former in that they seem to develop within a glacial-like icy mantle that blankets the surface rather than within an ice-rich and periglacially-revised regolith at/near the surface.Interestingly, the Type-2 depressions overlie the Type-1 depressions at some locations. If the periglacial/glacial morphological and stratigraphical dichotomy of depressions is valid, then this points to recent glaciation at some locations within the AR being precursed by at least one episode of periglaciation. This also suggests that periglaciation has a deeper history in the region than has been thought hitherto. Moreover, if the hypothesised differences amongst the Argyre-based depressions are mirrored in Utopia Planitia and Malea Planum, then perhaps this periglacial-glacial dichotomy and its associated geochronology are as relevant to understanding late period landscape-evolution in these two regions as it is in the AR

Quel développement durable pour le delta du Danube ? Enquête à Pardina

International audienceRecenser et prendre en compte les spécificités locales, identifier collectivement les enjeux,emboîter les différentes échelles d'action, tels sont les principaux défis pour répondre auxenjeux du développement durable concernant le delta du Danube, en général, et la communede Pardina, en particulier. Le delta présente un intérêt environnemental, économique etsocial évident. Il présente une forte biodiversité, sa richesse biologique s'expliquant parl'importance des zones humides et la diversité des habitats d’oiseaux. Le statut actuel dudelta comme réserve de la Biosphère devrait permettre la reconstitution progressive de cesrichesses malmenées par les politiques passées centrées sur l'accroissement de la productivitédes biens agricoles. Mais le contexte économique actuel met la population locale en difficulté.Cette dernière est confrontée à l’isolement, au retard en matière de modernisation ou detransformation des infrastructures existantes, à un chômage en hausse et à un vieillissementgénéralisé. L’un des objectifs en termes de développement durable pour cette zone consisteà définir une stratégie globale capable de concilier respect de la biodiversité, prospéritééconomique et vie décente

Honest elementary degrees and degrees of relative provability without the cupping property

An element a of a lattice cups to an element b>ab>a if there is a c<bc<b such that a∪c=ba∪c=b. An element of a lattice has the cupping property if it cups to every element above it. We prove that there are non-zero honest elementary degrees that do not have the cupping property, which answers a question of Kristiansen, Schlage-Puchta, and Weiermann. In fact, we show that if b is a sufficiently large honest elementary degree, then b has the anti-cupping property, which means that there is an a with 0<Ea<Eb0<Ea<Eb that does not cup to b. For comparison, we also modify a result of Cai to show, in several versions of the degrees of relative provability that are closely related to the honest elementary degrees, that in fact all non-zero degrees have the anti-cupping property, not just sufficiently large degrees

Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

OPPORTUNITIES FOR DRIVING CONTINUOUS IMPROVEMENT THROUGH TQM, LEAN AND SIX SIGMA WITHIN BUSINESS PROCESS MANAGEMENT

ABSTRAC

More than voters: parliamentary debates about emigrants in a new democracy

There is much research about how migrants engage with politics in their home countries and about how state institutions facilitate this involvement. Yet, we know little about how members of Parliament refer to, and debate, issues related to communities of emigrants. The ways in which legislators give voice to and represent the de-territorialized demos has broad implications for the functioning of contemporary democracies. This article analyzes the ways in which the Romanian parliamentarians refer to emigrants. We focus on the parliamentary speeches from the plenary sessions in the Chamber of Deputies in the two most recent terms in office (2012–2016 and 2016–2020). The study includes 239 parliamentary speeches and uses thematic analysis. Our results identify an ambivalent attitude toward emigrants that transcends political divides. The Romanian legislators express concerns related to the representation of emigrants and their needs and see them as a valuable pool of economic and electoral support

Speaking out against the discrimination of Romanians abroad: an analysis of parliamentary speeches in the home country

Discrimination against minority ethnic groups has often been analyzed through the lenses of institutional action, antiminority rhetoric, and media framing in the countries of residence. However, we know little about how ethnic discrimination is approached in the home countries of these minorities. To address this gap in the literature, our article seeks to explain how Romanian parliamentarians address discrimination against coethnics abroad. We use inductive thematic analysis conducted on all of the parliamentary speeches about the discrimination of coethnics abroad in the Chamber of Deputies between 2008 and 2020. Our results indicate a relatively high degree of descriptive representation and an extensive concern about discrimination of coethnics abroad from parliamentarians across the political spectrum. The speeches about discrimination differ in content relative to the coethnic community of reference

A thermodynamic model for the precipitation of nanostructured copper oxalates

A thermodynamic model is developed for the precipitation of copper oxalate from aqueous solutions of copper nitrate and sodium oxalate in a small well-mixed batch reactor. This model is then used to explain the discrepancy between experimental pH evolution and the predicted evolution for the precipitation of copper oxalate as the only solid phase. The experimental behaviour is simulated by taking into account the possible precipitation of small quantities of copper hydroxyl carbonates from adventitious CO2. Experiments with controlled CO2 partial pressures illustrate the power of these types of simulations in helping elucidate precipitation reactions. The thermodynamic model can help simulate the kinetics of precipitation by linking precipitation yield with real time pH measurements