363 research outputs found

    Loyauté et nationalité : problématique européenne

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    Parent-child bonding and attachment during pregnancy and early childhood following congenital heart disease diagnosis

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    Diagnosis and treatment of congenital heart disease (CHD) can present challenges to the developing parent-child relationship due to periods of infant hospitalisation and intensive medical care, parent-infant separations, child neurodevelopmental delay and feeding problems, and significant parent and child distress and trauma. Yet, the ways in which CHD may affect the parent-child relationship are not well-understood. We systematically reviewed the evidence on parental bonding, parent-child interaction, and child attachment following CHD diagnosis, according to a pre-registered protocol (CRD42019135687). Six electronic databases were searched for English-language studies comparing a cardiac sample (i.e., expectant parents or parents and their child aged 0-5 years with CHD) with a healthy comparison group on relational outcomes. Of 22 identified studies, most used parent-report measures (73%) and yielded mixed results for parental bonding and parent-child interaction quality. Observational results also varied, although most studies (4 of 6) found difficulties in parent-child interaction on one or more affective or behavioural domains (e.g., lower maternal sensitivity, lower infant responsiveness). Research on parental-fetal bonding, father-child relationships, and child attachment behaviour was lacking. Stronger evidence is needed to determine the nature, prevalence, and predictors of relational disruptions following CHD diagnosis, and to inform targeted screening, prevention, and early intervention programs for at-risk dyads

    Evidence for thermal-stress-induced rockfalls on Mars impact crater slopes

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    Here we study rocks falling from exposed outcrops of bedrock, which have left tracks on the slope over which they have bounced and/or rolled, in fresh impact craters (1–10 km in diameter) on Mars. The presence of these tracks shows that these rocks have fallen relatively recently because aeolian processes are known to infill topographic lows over time. Mapping of rockfall tracks indicate trends in frequency with orientation, which in turn depend on the latitudinal position of the crater. Craters in the equatorial belt (between 15°N and 15°S) exhibit higher frequencies of rockfall on their N-S oriented slopes compared to their E-W ones. Craters >15° N/S have notably higher frequencies on their equator-facing slopes as opposed to the other orientations. We computed solar radiation on the surface of crater slopes to compare insolation patterns and rockfall spatial distribution, and find statistically significant correlations between maximum diurnal insolation and rockfall frequency. Our results indicate that solar-induced thermal stress plays a more important role under relatively recent climate conditions in rock breakdown and preconditioning slopes for rockfalls than phase transitions of H2O or CO2, at mid and equatorial latitudes. Thermal stress should thus be considered as an important factor in promoting mass-wasting process on impact crater walls and other steep slopes on Mars

    Evidence for thermal fatigue on Mars from rockfall patterns on impact crater slopes

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    Individual block falls are one of the currently active surface processes on Mars. Similarly to Earth, clasts detach from upslope outcrops roll or bounce downslope, leaving a track on the substratum (Fig. 1). The trails show that the rockfalls are recent, as aeolian processes would infill topographic lows over time. Using rover-track erasure rates, these tracks are likely <100 ka. On Earth, slope instability is usually caused by phase changes of H2O [1]. However, solar-induced thermal stress could also play a key-role in rock breakdown leading to rockfalls [2]. Although liquid water is not stable at the surface of Mars today, sub-surface water ice is known to be present from mid- to high-latitudes [3]. Water ice and CO2 seasonal frost on shadowed pole-facing slopes may exist at latitudes down to 30° [4] or less [5]. On the other hand, insolation-related thermal stress has been used to explain fracture orientation patterns in martian boulders observed by the Mars Exploration Rovers [6] and other studies suggest that it could cause rock breakdown on airless bodies [7]. Therefore, both phase transitions and solar-induced thermal stress are plausible mechanisms for rock breakdown and preconditioning slopes for rockfalls on modern Mars. In this study we analyze distribution of rockfalls on impact crater walls to assess whether one of these mechanisms could be involved in local rock breakdown

    The Word Problem for Omega-Terms over the Trotter-Weil Hierarchy

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    For two given ω\omega-terms α\alpha and β\beta, the word problem for ω\omega-terms over a variety V\boldsymbol{\mathrm{V}} asks whether α=β\alpha=\beta in all monoids in V\boldsymbol{\mathrm{V}}. We show that the word problem for ω\omega-terms over each level of the Trotter-Weil Hierarchy is decidable. More precisely, for every fixed variety in the Trotter-Weil Hierarchy, our approach yields an algorithm in nondeterministic logarithmic space (NL). In addition, we provide deterministic polynomial time algorithms which are more efficient than straightforward translations of the NL-algorithms. As an application of our results, we show that separability by the so-called corners of the Trotter-Weil Hierarchy is witnessed by ω\omega-terms (this property is also known as ω\omega-reducibility). In particular, the separation problem for the corners of the Trotter-Weil Hierarchy is decidable

    Reasoning with the HERMIT: tool support for equational reasoning on GHC core programs

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    A benefit of pure functional programming is that it encourages equational reasoning. However, the Haskell language has lacked direct tool support for such reasoning. Consequently, reasoning about Haskell programs is either performed manually, or in another language that does provide tool support (e.g. Agda or Coq). HERMIT is a Haskell-specific toolkit designed to support equational reasoning and user-guided program transformation, and to do so as part of the GHC compilation pipeline. This paper describes HERMIT’s recently developed support for equational reasoning, and presents two case studies of HERMIT usage: checking that type-class laws hold for specific instance declarations, and mechanising textbook equational reasoning

    Deficiency and Also Transgenic Overexpression of Timp-3 Both Lead to Compromised Bone Mass and Architecture In Vivo

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    Tissue inhibitor of metalloproteinases-3 (TIMP-3) regulates extracellular matrix via its inhibition of matrix metalloproteinases and membrane-bound sheddases. Timp-3 is expressed at multiple sites of extensive tissue remodelling. This extends to bone where its role, however, remains largely unresolved. In this study, we have used Micro-CT to assess bone mass and architecture, histological and histochemical evaluation to characterise the skeletal phenotype of Timp-3 KO mice and have complemented this by also examining similar indices in mice harbouring a Timp-3 transgene driven via a Col-2a-driven promoter to specifically target overexpression to chondrocytes. Our data show that Timp-3 deficiency compromises tibial bone mass and structure in both cortical and trabecular compartments, with corresponding increases in osteoclasts. Transgenic overexpression also generates defects in tibial structure predominantly in the cortical bone along the entire shaft without significant increases in osteoclasts. These alterations in cortical mass significantly compromise predicted tibial load-bearing resistance to torsion in both genotypes. Neither Timp-3 KO nor transgenic mouse growth plates are significantly affected. The impact of Timp-3 deficiency and of transgenic overexpression extends to produce modification in craniofacial bones of both endochondral and intramembranous origins. These data indicate that the levels of Timp-3 are crucial in the attainment of functionally-appropriate bone mass and architecture and that this arises from chondrogenic and osteogenic lineages

    Anatomy and origin of authochthonous late Pleistocene forced regression deposits, east Coromandel inner shelf, New Zealand: implications for the development and definition of the regressive systems tract

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    High-resolution seismic reflection data from the east Coromandel coast, New Zealand, provide details of the sequence stratigraphy beneath an autochthonous, wave dominated inner shelf margin during the late Quaternary (0-140 ka). Since c. 1 Ma, the shelf has experienced limited subsidence and fluvial sediment input, producing a depositional regime characterised by extensive reworking of coastal and shelf sediments during glacio-eustatic sea-level fluctuations. It appears that only one complete fifth-order (c. 100 000 yr) depositional sequence is preserved beneath the inner shelf, the late Pleistocene Waihi Sequence, suggesting any earlier Quaternary sequences were mainly cannibalised into successively younger sequences. The predominantly Holocene-age Whangamata Sequence is also evident in seismic data and modern coastal deposits, and represents an incomplete depositional sequence in its early stages of formation. A prominent aspect of the sequence stratigraphy off parts of the east Coromandel coast is the presence of forced regressive deposits (FRDs) within the regressive systems tract (RST) of the late Pleistocene Waihi Sequence. The FRDs are interpreted to represent regressive barrier-shoreface sands that were sourced from erosion and onshore reworking of underlying Pleistocene sediments during the period of slow falling sea level from isotope stages 5 to 2 (c. 112-18 ka). The RST is volumetrically the most significant depositional component of the Waihi Sequence; the regressive deposits form a 15-20 m thick, sharp-based, tabular seismic unit that downsteps and progrades continuously across the inner shelf. The sequence boundary for the Waihi Sequence is placed at the most prominent, regionally correlative, and chronostratigraphically significant surface, namely an erosional unconformity characterised in many areas by large incised valleys that was generated above the RST. This unconformity is interpreted as a surface of maximum subaerial erosion generated during the last glacial lowstand (c. 18 ka). Although the base of the RST is associated with a prominent regressive surface of erosion, this is not used as the sequence boundary as it is highly diachronous and difficult to identify and correlate where FRDs are not developed. The previous highstand deposits are limited to subaerial barrier deposits preserved behind several modern Holocene barriers along the coast, while the transgressive systems tract is preserved locally as incised-valley fill deposits beneath the regressive surface of erosion at the base of the RST. Many documented late Pleistocene RSTs have been actively sourced from fluvial systems feeding the shelf and building basinward-thickening, often stacked wedges of FRDs, for which the name allochthonous FRDs is suggested. The Waihi Sequence RST is unusual in that it appears to have been sourced predominantly from reworking of underlying shelf sediments, and thus represents an autochthonous FRD. Autochthonous FRDs are also present on the Forster-Tuncurry shelf in southeast Australia, and may be a common feature in other shelf settings with low subsidence and low sediment supply rates, provided shelf gradients are not too steep, and an underlying source of unconsolidated shelf sediments is available to source FRDs. The preservation potential of such autochthonous FRDs in ancient deposits is probably low given that they are likely to be cannibalised during subsequent sea-level falls
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