Understanding amorphous phase-change materials from the viewpoint of Maxwell rigidity

Phase-change materials (PCMs) are the subject of considerable interest because they have been recognized as potential active layers for next-generation non-volatile memory devices, known as Phase Change Random Access Memories (PRAMs). By analyzing First Principles Molecular Dynamics simulations we develop a new method for the enumeration of mechanical constraints in the amorphous phase and show that the phase diagram of the most popular system (Ge-Sb-Te) can be split into two compositional regions having a well-defined mechanical character: a Tellurium rich flexible phase, and a stressed rigid phase that encompasses the known PCMs. This sound atomic scale insight should open new avenues for the understanding of PCMs and other complex amorphous materials from the viewpoint of rigidity.Comment: 5 pages, 4 figures in EP

Cephalopod-omics: emerging fields and technologies in cephalopod biology

Few animal groups can claim the level of wonder that cephalopods instill in the minds of researchers and the general public. Much of cephalopod biology, however, remains unexplored: the largest invertebrate brain, difficult husbandry conditions, complex (meta-)genomes, among many other things, have hindered progress in addressing key questions. However, recent technological advancements in sequencing, imaging, and genetic manipulation have opened new avenues for exploring the biology of these extraordinary animals. The cephalopod molecular biology community is thus experiencing a large influx of researchers, emerging from different fields, accelerating the pace of research in this clade. In the first post-pandemic event at the Cephalopod International Advisory Council (CIAC) conference in April 2022, over 40 participants from all over the world met and discussed key challenges and perspectives for current cephalopod molecular biology and evolution. Our particular focus was on the fields of comparative and regulatory genomics, gene manipulation, single cell transcriptomics, metagenomics and microbial interactions. This article is a result of this joint effort, summarizing the latest insights from these emerging fields, their bottlenecks and potential solutions. The article highlights the interdisciplinary nature of the cephalopod -omics community and provides an emphasis on continuous consolidation of efforts and collaboration in this rapidly evolving field

Neuro-molecular characterization of fish cleaning interactions

Coral reef fish exhibit a large variety of behaviours crucial for fitness and survival. The cleaner wrasse Labroides dimidiatus displays cognitive abilities during interspecific interactions by providing services of ectoparasite cleaning, thus serving as a good example to understand the processes of complex social behaviour. However, little is known about the molecular underpinnings of cooperative behaviour between L. dimidiatus and a potential client fish (Acanthurus leucosternon). Therefore, we investigated the molecular mechanisms in three regions of the brain (Fore-, Mid-, and Hindbrain) during the interaction of these fishes. Here we show, using transcriptomics, that most of the transcriptional response in both species was regulated in the Hindbrain and Forebrain regions and that the interacting behaviour responses of L. dimidiatus involved immediate early gene alteration, dopaminergic and glutamatergic pathways, the expression of neurohormones (such as isotocin) and steroids (e.g. progesterone and estrogen). In contrast, in the client, fewer molecular alterations were found, mostly involving pituitary hormone responses. The particular pathways found suggested synaptic plasticity, learning and memory processes in the cleaner wrasse, while the client indicated stress relief

Neuromolecular responses in disrupted mutualistic cleaning interactions under future environmental conditions

16 pages, 5 figures, supplementary information https://doi.org/10.1186/s12915-023-01761-5.-- Availability of data and materials: The data that support the findings of this study containing the raw sequencing files and de novo transcriptome assemblies (Labroides dimidiatus and Acanthurus leucosternon) are openly available under the NCBI BioProject PRJNA726349 [47] and TSA accession number GJED00000000Background: Mutualistic interactions, which constitute some of the most advantageous interactions among fish species, are highly vulnerable to environmental changes. A key mutualistic interaction is the cleaning service rendered by the cleaner wrasse, Labroides dimidiatus, which involves intricate processes of social behaviour to remove ectoparasites from client fish and can be altered in near-future environmental conditions. Here, we evaluated the neuromolecular mechanisms behind the behavioural disruption of cleaning interactions in response to future environments. We subjected cleaner wrasses and surgeonfish (Acanthurus leucosternon, serving as clients) to elevated temperature (warming, 32 °C), increased levels of CO2 (high CO2, 1000 ppm), and a combined condition of elevated CO2 and temperature (warming and high CO2, 32 °C, and 1000 ppm) for 28 days. Results: Each of these conditions resulted in behavioural disruptions concerning the motivation to interact and the quality of interaction (high CO2 − 80.7%, warming − 92.6%, warming and high CO2 − 79.5%, p < 0.001). Using transcriptomics of the fore-, mid-, and hindbrain, we discovered that most transcriptional reprogramming in both species under warming conditions occurred primarily in the hind- and forebrain. The associated functions under warming were linked to stress, heat shock proteins, hypoxia, and behaviour. In contrast, elevated CO2 exposure affected a range of functions associated with GABA, behaviour, visual perception, thyroid hormones and circadian rhythm. Interestingly, in the combined warming and high CO2 condition, we did not observe any expression changes of behaviour. However, we did find signs of endoplasmic reticulum stress and apoptosis, suggesting not only an additive effect of the environmental conditions but also a trade-off between physiological performance and behaviour in the cleaner wrasse. Conclusions: We show that impending environmental shifts can affect the behaviour and molecular processes that sustain mutualistic interactions between L. dimidiatus and its clients, which could have a cascading effect on their adaptation potential and possibly cause large-scale impacts on coral reef ecosystemsThis work was supported by the Hong Kong Research Grant Committee Early Career Scheme fund 27107919 (CS) and FCT—Fundação para a Ciência e Tecnologia, I.P., within the project grant PTDC/BIA-BMA/0080/2021—ChangingMoods, the scientific employment stimulus program 2021.01030. CEECIND, the strategic project UIDB/04292/2020 granted to MARE, project LA/P/0069/2020 granted to the Associate Laboratory ARNET, and the PhD scholarship UI/BD/151019/2021 awarded to EOWith the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

Establishment of a murine graft-versus-myeloma model using allogeneic stem cell transplantation

Background: Multiple myeloma (MM) is a malignant plasma cell disorder with poor long-term survival and high recurrence rates. Despite evidence of graft-versus-myeloma (GvM) effects, the use of allogeneic hematopoietic stem cell transplantation (allo-SCT) has remained controversial in MM. In the current study, we investigated the anti-myeloma effects of allo-SCT from B10.D2 mice into MHC-matched myeloma-bearing Balb/cJ mice (previously injected with the MOPC315.BM myeloma cell line), based on a chronic graft-versus-host disease (GvHD) murine model. Methods and results: Balb/cJ mice were injected intravenously with luciferase-transfected MOPC315.BM cells, and received 30 days later an allogeneic (B10.D2 donor) or autologous (Balb/cJ donor) transplantation by intravenous administration of bone marrow cells and splenocytes. We observed a graft-versus-myeloma effect in 94% of the allogeneic transplanted mice, as luciferase signal completely disappeared after transplantation, whereas all the autologous transplanted mice showed myeloma evolution. Lower serum paraprotein levels and myeloma infiltration in bone marrow and spleen in the allogeneic setting confirmed the observed GvM effect, while allogeneic mice also displayed chronic GvHD symptoms. In vivo and in vitro data suggest the involvement of effector memory CD4 and CD8 T cells in the GvM effect. The essential role of CD8 T cells was demonstrated in vivo where CD8 T-cell depletion of the graft resulted in reduced GvM effects. Finally, TCR V spectratyping analysis identified V families within CD4 and CD8 T cells which were associated with both GvM effects and GVHD, whereas other V families within CD4 T cells were associated exclusively with either GvM or GvHD responses. Conclusions: We successfully established an immunocompetent murine model of graft-versus-myeloma. This is the first immunocompetent murine model which is based on a MM model closely resembling human MM disease (bone marrow tropism, ...) and using allo-SCT after the disease establishment, as a curative treatmen