Impact of mesh resolution for MISMIP and MISMIP3d experiments using Elmer/Ice

International audienceThe dynamical contribution of marine ice sheets to sea level rise is largely controlled by grounding line (GL) dynamics. Two marine ice sheet model intercomparison exercises , namely MISMIP and MISMIP3d, have been proposed to the community to test and compare the ability of models to capture the GL dynamics. Both exercises are known to present a discontinuity of the friction at the GL, which is believed to increase the model sensitivity to mesh resolution. Here, using Elmer/Ice, the only Stokes model which completed both intercomparisons, the sensitivity to the mesh resolution is studied from an extended MISMIP experiment in which the friction continuously decreases over a transition distance and equals zero at the GL. Using this MISMIP-like setup, it is shown that the sensitivity to the mesh resolution is not improved for a vanishing friction at the GL. For the original MISMIP experiment, i.e. for a discontinuous friction at the GL, we further show that the results are moreover very sensitive to the way the friction is interpolated in the close vicinity of the GL. In the light of these new insights, and thanks to increased computing resources, new results for the MISMIP3d experiments obtained for higher resolutions than previously published are made available for future comparisons as the Supplement

Mentalizing subtypes in eating disorders: A latent profile analysis

Background: Mentalizing, the mental capacity to understand oneself and others in terms of mental states, has been found to be reduced in several mental disorders. Some studies have suggested that eating disorders (EDs) may also be associated with impairments in mentalizing. The aim of this work is to investigate the possible presence of mentalizing subtypes in a sample of patients with EDs. Method: A sample of patients with eating disorders (N = 157) completed a battery of measures assessing mentalization and related variables, including the Reflective Functioning Questionnaire (RFQ), the Difficulties in Emotion Regulation Strategies (DERS), the Interpersonal Reactivity Index (IRI). Clinicians rated patients in relation to imbalances in different dimensions of mentalization to prementalizing modes and attachment style by using the Mentalization Imbalances Scale, the Modes of Mentalization Scale (MMS), and the Adult Attachment Questionnaire. A latent profile analysis was conducted to test the possible presence of different subgroups. MANOVA was used to test the possible differences between the four mentalizing profiles in relation to emotion dysregulation (DERS), empathy (IRI), and adequate and impairments in mentalizing (MMS and RFQ). Results: The latent profile analysis suggested the presence of four different profiles in relation to impairments in the dimensions of mentalization: (1) affective/self/automatic imbalances, (2) external imbalance, (3) cognitive/self/automatic imbalances, and (4) cognitive/other/automatic imbalances. Patients belonging to profile 1 are characterized by the prevalence of affective mentalization that overwhelms the capacity to reflect on mental states with an imbalance on the self-dimension; profile 2 patients are excessively focused on the external cues of mentalization; profile 3 patients are characterized by an over-involvement on the cognitive and self-facets of mentalization, with an impairment in adopting the other mind perspective; and profile 4 patients have similar impairments compared to profile 3 patients but with an excessive focus on others and deficits in self-reflection. These profiles were heterogeneous in terms of EDs represented in each group and presented significant differences on various variables such as attachment style, emotion dysregulation, empathy, interpersonal reactivity, and reflective function. This study represents, so far, the first work that confirms the presence of different mentalizing patterns in ED patients. Conclusions: ED patients can be classified in relation to impairments in different dimensions of mentalization above and beyond ED diagnosis

Adaptive mesh refinement versus subgrid friction interpolation in simulations of Antarctic ice dynamics

Geophysical Research Letters

A Novel Strategy to Enhance Mesenchymal Stem Cell Migration Capacity and Promote Tissue Repair in an Injury Specific Fashion

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Generalization of the Luttinger Theorem for Fermionic Ladder Systems

We apply a generalized version of the Lieb-Schultz-Mattis Theorem to fermionic ladder systems to show the existence of a low-lying excited state (except for some special fillings). This can be regarded as a non-perturbative proof for the conservation under interaction of the sum of the Fermi wave vectors of the individual channels, corresponding to a generalized version of the Luttinger Theorem to fermionic ladder systems. We conclude by noticing that the Lieb-Schultz-Mattis Theorem is not applicable in this form to show the existence of low-lying excitations in the limit that the number of legs goes to infinity, e.g. in the limit of a 2D plane.Comment: RevTex, 4 pages with 4 eps figure

Chitin and Its Derivatives: Nanostructured Materials from Different Marine and Terrestrial Sources

Chitin is a very abundant polysaccharide that can be obtained from well-known marine sources (crustaceans), but also from terrestrial sources (mushrooms and insects). In the case where animal sources are considered, the material can be obtained by much abundant food or feeding waste. The extraction methodologies were not developed with similar technical readiness levels considering the different sources and the further conversion to chitin nanofibrils and chitosan is also under study, enabling the production of products differentiated for their macromolecular structures and morphology.Chitin nanofibrils from sea food sources were used in sanitary, cosmetic and packaging applications, where their anti-microbial properties and good biocompatibility were very useful. Chitin from mushrooms and sea food was used as starting material in possible coatings for cellulosic and bioplastic substrates. Currently chitin from insects (Hermetia Illucens) is also under study as well as the methodologies for extracting derivatives from it. Infrared analysis is an interesting technique to compare chitins, chitin nanofibrils and chitosan from different sources as well as electron microscopy for studying their morphology. The derivatives of chitin, such as chitosan and chitin nanofibrils, show anti-microbial properties. Hence, their use in several applications, ranging from packaging to sanitary and cosmetics, can conjugate high performance novel products with a reduced environmental concern. The comparison between chitin derivatives from different sources is very useful to address the biopolymers to specific applications, including the agricultural sector. While more and more applications for chitin derivatives will be developed, differences between them should be clarified and correlated to the sources, the methodologies of their production and their physical-chemical properties

Human and Viral microRNA Expression in Acute and Chronic HIV Infections

Human and viral microRNAs (miRNAs) are involved in the regulation of gene transcription, and the establishment of their profiles in acute (AHI) and chronic (CHI) HIV infections may shed light on the pathogenetic events related to different phases of HIV disease. Next-generation sequencing (NGS) of miRNA libraries was performed, and the reads were used to analyze miRNA differential expression in the plasma with AHI and CHI. Functional analysis was then undertaken to investigate the biological processes characterizing the two phases of HIV infection. Except for hsa-miR-122-5p, which was found in 3.39% AHI vs. 0.18% CHI, the most represented human miRNAs were similarly represented in AHI and CHI. However, when considering the overall detected miRNAs in AHI and CHI, 15 displayed differential expression (FDR p < 0.05). Functional analysis identified 163 target mRNAs involved in promoting angiogenesis activation in AHI versus CHI through the action of hsa-miR10b-5p, hsa-miR1290, hsa-miR1-3p, and hsa-miR296-5p. The viral miRNAs detected, all belonging to herpesviruses, accounted for only 0.014% of total reads. The present data suggest that AHI patients exhibit strong innate immune activation through the upregulation of hsa-miR-122-5p and early activation of angiogenesis. More specific investigations are needed to study the role of viral miRNAs in HIV pathogenesis

Genotypic HIV-1 tropism determination might help to identify people with exhausted treatment options and advanced disease

Objectives: To evaluate HIV-1 tropism in 1382 combined antiretroviral therapy (cART)-experienced patients failing therapy to characterize those with exhausted therapeutic options. Methods: HIV-1 genotypic tropism was inferred through Geno2Pheno by estimating the false-positive-rate (FPR) values. Cumulative resistance and drug activity were evaluated by Stanford algorithm. Results: Overall, median (IQR) CD4 count (cells/mm3) nadir and at last genotypic resistance test (GRT) available were 98 (33-211) and 312 (155-517), respectively. Considering HIV-1 tropism, 30.5% had X4/dual-mixed strains (FPR ≤5%: 22.2%; FPR 5%-10%: 8.3%). By stratifying according to tropism, by decreasing FPR, a significant decrease of CD4 nadir and at last GRT was observed. The proportion of individuals with CD4 count <200 cells/mm3, who were perinatally infected and with a long treatment history significantly increased as FPR levels decreased. Regarding resistance, 933 (67.5%) individuals accumulated at least one class resistance, with 52.7%, 48.2%, 23.5% and 13.2% of individuals showing resistance to NRTIs, NNRTIs, PIs and INIs; while 23.2%, 27.2%, 14.3% and 2.8% harboured resistance to 1, 2, 3 and 4 classes, respectively. Individuals with FPR ≤5% showed a significantly higher level of resistance to PIs, NRTIs and INIs compared with others. The proportion of individuals harbouring strains susceptible to ≤2 active drugs was only about 2%; nonetheless, this proportion doubled (4.6%) in patients infected with FPR ≤5%. Conclusions: Our findings showed that a small proportion of cART failing individuals have limited therapeutic options. However, tropism determination might help to identify people who have accumulated a high level of resistance and have a greater risk of advanced disease