ITER LHe Plants Parallel Operation

AbstractThe ITER Cryogenic System includes three identical liquid helium (LHe) plants, with a total average cooling capacity equivalent to 75kW at 4.5K.The LHe plants provide the 4.5 K cooling power to the magnets and cryopumps. They are designed to operate in parallel and to handle heavy load variations.In this proceedingwe will describe the presentstatusof the ITER LHe plants with emphasis on i) the project schedule, ii) the plantscharacteristics/layout and iii) the basic principles and control strategies for a stable operation of the three LHe plants in parallel

Field Observations of Wave-induced Headland Rips

Mouragues, A.; Bonneton, P.; Castelle, B.; Marieu, V.; Barrett, A.; Bonneton, N.; Detand, G.; Martins, K.; McCarroll, J.; Morichon, D.; Poate, T.; Rodriguez Padilla, I.; Scott, T., and Sous, D., 2020. Field observations of wave-induced headland rips. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 578-582. Coconut Creek (Florida), ISSN 0749-0208. Most of rip-current field experiments have focused on persistent rips along rip-channeled sandy beaches or transient rips along reasonably alongshore-uniform surf-zone morphology, while experiments on rip flowing against structures are scarce. In October 2018, a 3-week field experiment was performed at Anglet beach, SW France, aiming at examining the dynamics of high-energy rip currents in complex settings. The beach is barred with prominent inherited geology, characterized by the presence of a 500-m headland and a natural submerged reef. A large array of in-situ instruments was deployed to capture the temporal and spatial variability of rip flow circulations, including ADCPs, surf-zone drifters and video monitoring. The latter allowed to identify a wide range of rip-flow patterns. Among these patterns, a high-intensity rip current flowing against the headland was a dominant feature for obliquely incident waves. Such a boundary rip current was driven by the deflection of the longshore current against the headland, peaking at 0.7 m/s (5-min time- and depth-averaged) 800-m offshore in 12-m depth for a moderate storm event with 4-m obliquely incident waves. Very-low-frequency (O(1h) and O(30min)) fluctuations of this rip current were observed around low tide. Measurements of the vertical structure of the rip reveal that the deflection rip was more vertically-sheared as the water depth increases, with higher velocities near the surface, which is typical of a theoretical rip head structure

The nuclear receptors of Biomphalaria glabrata and Lottia gigantea: Implications for developing new model organisms

© 2015 Kaur et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNuclear receptors (NRs) are transcription regulators involved in an array of diverse physiological functions including key roles in endocrine and metabolic function. The aim of this study was to identify nuclear receptors in the fully sequenced genome of the gastropod snail, Biomphalaria glabrata, intermediate host for Schistosoma mansoni and compare these to known vertebrate NRs, with a view to assessing the snail's potential as a invertebrate model organism for endocrine function, both as a prospective new test organism and to elucidate the fundamental genetic and mechanistic causes of disease. For comparative purposes, the genome of a second gastropod, the owl limpet, Lottia gigantea was also investigated for nuclear receptors. Thirty-nine and thirty-three putative NRs were identified from the B. glabrata and L. gigantea genomes respectively, based on the presence of a conserved DNA-binding domain and/or ligand-binding domain. Nuclear receptor transcript expression was confirmed and sequences were subjected to a comparative phylogenetic analysis, which demonstrated that these molluscs have representatives of all the major NR subfamilies (1-6). Many of the identified NRs are conserved between vertebrates and invertebrates, however differences exist, most notably, the absence of receptors of Group 3C, which includes some of the vertebrate endocrine hormone targets. The mollusc genomes also contain NR homologues that are present in insects and nematodes but not in vertebrates, such as Group 1J (HR48/DAF12/HR96). The identification of many shared receptors between humans and molluscs indicates the potential for molluscs as model organisms; however the absence of several steroid hormone receptors indicates snail endocrine systems are fundamentally different.The National Centre for the Replacement, Refinement and Reduction of Animals in Research, Grant Ref:G0900802 to CSJ, LRN, SJ & EJR [www.nc3rs.org.uk]

Molecular Evolution of Ultraspiracle Protein (USP/RXR) in Insects

Ultraspiracle protein/retinoid X receptor (USP/RXR) is a nuclear receptor and transcription factor which is an essential component of a heterodimeric receptor complex with the ecdysone receptor (EcR). In insects this complex binds ecdysteroids and plays an important role in the regulation of growth, development, metamorphosis and reproduction. In some holometabolous insects, including Lepidoptera and Diptera, USP/RXR is thought to have experienced several important shifts in function. These include the acquisition of novel ligand-binding properties and an expanded dimerization interface with EcR. In light of these recent hypotheses, we implemented codon-based likelihood methods to investigate if the proposed shifts in function are reflected in changes in site-specific evolutionary rates across functional and structural motifs in insect USP/RXR sequences, and if there is any evidence for positive selection at functionally important sites. Our results reveal evidence of positive selection acting on sites within the loop connecting helices H1 and H3, the ligand-binding pocket, and the dimer interface in the holometabolous lineage leading to the Lepidoptera/Diptera/Trichoptera. Similar analyses conducted using EcR sequences did not indicate positive selection. However, analyses allowing for variation across sites demonstrated elevated non-synonymous/synonymous rate ratios (dN/dS), suggesting relaxed constraint, within the dimerization interface of both USP/RXR and EcR as well as within the coactivator binding groove and helix H12 of USP/RXR. Since the above methods are based on the assumption that dS is constant among sites, we also used more recent models which relax this assumption and obtained results consistent with traditional random-sites models. Overall our findings support the evolution of novel function in USP/RXR of more derived holometabolous insects, and are consistent with shifts in structure and function which may have increased USP/RXR reliance on EcR for cofactor recruitment. Moreover, these findings raise important questions regarding hypotheses which suggest the independent activation of USP/RXR by its own ligand

STK35L1 Associates with Nuclear Actin and Regulates Cell Cycle and Migration of Endothelial Cells

BACKGROUND: Migration and proliferation of vascular endothelial cells are essential for repair of injured endothelium and angiogenesis. Cyclins, cyclin-dependent kinases (CDKs), and cyclin-dependent kinase inhibitors play an important role in vascular tissue injury and wound healing. Previous studies suggest a link between the cell cycle and cell migration: cells present in the G(1) phase have the highest potential to migrate. The molecular mechanism linking these two processes is not understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we explored the function of STK35L1, a novel Ser/Thr kinase, localized in the nucleus and nucleolus of endothelial cells. Molecular biological analysis identified a bipartite nuclear localization signal, and nucleolar localization sequences in the N-terminal part of STK35L1. Nuclear actin was identified as a novel binding partner of STK35L1. A class III PDZ binding domains motif was identified in STK35L1 that mediated its interaction with actin. Depletion of STK35L1 by siRNA lead to an accelerated G(1) to S phase transition after serum-stimulation of endothelial cells indicating an inhibitory role of the kinase in G(1) to S phase progression. Cell cycle specific genes array analysis revealed that one gene was prominently downregulated (8.8 fold) in STK35L1 silenced cells: CDKN2A alpha transcript, which codes for p16(INK4a) leading to G(1) arrest by inhibition of CDK4/6. Moreover in endothelial cells seeded on Matrigel, STK35L1 expression was rapidly upregulated, and silencing of STK35L1 drastically inhibited endothelial sprouting that is required for angiogenesis. Furthermore, STK35L1 depletion profoundly impaired endothelial cell migration in two wound healing assays. CONCLUSION/SIGNIFICANCE: The results indicate that by regulating CDKN2A and inhibiting G1- to S-phase transition STK35L1 may act as a central kinase linking the cell cycle and migration of endothelial cells. The interaction of STK35L1 with nuclear actin might be critical in the regulation of these fundamental endothelial functions

9-Genes Reinforce the Phylogeny of Holometabola and Yield Alternate Views on the Phylogenetic Placement of Strepsiptera

Background: The extraordinary morphology, reproductive and developmental biology, and behavioral ecology of twisted wing parasites (order Strepsiptera) have puzzled biologists for centuries. Even today, the phylogenetic position of these enigmatic “insects from outer space” [1] remains uncertain and contentious. Recent authors have argued for the placement of Strepsiptera within or as a close relative of beetles (order Coleoptera), as sister group of flies (order Diptera), or even outside of Holometabola.Methodology/Principal Findings Here, we combine data from several recent studies with new data (for a total of 9 nuclear genes and ∼13 kb of aligned data for 34 taxa), to help clarify the phylogenetic placement of Strepsiptera. Our results unequivocally support the monophyly of Neuropteroidea ( = Neuropterida + Coleoptera) + Strepsiptera, but recover Strepsiptera either derived from within polyphagan beetles (order Coleoptera), or in a position sister to Neuropterida. All other supra-ordinal- and ordinal-level relationships recovered with strong nodal support were consistent with most other recent studies. Conclusions/Significance: These results, coupled with the recent proposed placement of Strepsiptera sister to Coleoptera, suggest that while the phylogenetic neighborhood of Strepsiptera has been identified, unequivocal placement to a specific branch within Neuropteroidea will require additional study.Organismic and Evolutionary Biolog

Mysid crustaceans as standard models for the screening and testing of endocrine-disrupting chemicals

Author Posting. © Springer, 2007. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Ecotoxicology 16 (2007): 205-219, doi:10.1007/s10646-006-0122-0.Investigative efforts into the potential endocrine-disrupting effects of chemicals have mainly concentrated on vertebrates, with significantly less attention paid to understanding potential endocrine disruption in the invertebrates. Given that invertebrates account for at least 95% of all known animal species and are critical to ecosystem structure and function, it remains essential to close this gap in knowledge and research. The lack of progress regarding endocrine disruption in invertebrates is still largely due to: (1) our ignorance of mode-of-action, physiological control, and hormone structure and function in invertebrates; (2) lack of a standardized invertebrate assay; (3) the irrelevance to most invertebrates of the proposed activity-based biological indicators for endocrine disruptor exposure (androgen, estrogen and thyroid); (4) limited field studies. Past and ongoing research efforts using the standard invertebrate toxicity test model, the mysid shrimp, have aimed at addressing some of these issues. The present review serves as an update to a previous publication on the use of mysid shrimp for the evaluation of endocrine disruptors (Verslycke et al., 2004a). It summarizes recent investigative efforts that have significantly advanced our understanding of invertebrate-specific endocrine toxicity, population modeling, field studies, and transgeneration standard test development using the mysid model.Supported by a Fellowship of the Belgian American Educational Foundation

Pre-Bilaterian Origins of the Hox Cluster and the Hox Code: Evidence from the Sea Anemone, Nematostella vectensis

BACKGROUND: Hox genes were critical to many morphological innovations of bilaterian animals. However, early Hox evolution remains obscure. Phylogenetic, developmental, and genomic analyses on the cnidarian sea anemone Nematostella vectensis challenge recent claims that the Hox code is a bilaterian invention and that no “true” Hox genes exist in the phylum Cnidaria. METHODOLOGY/PRINCIPAL FINDINGS: Phylogenetic analyses of 18 Hox-related genes from Nematostella identify putative Hox1, Hox2, and Hox9+ genes. Statistical comparisons among competing hypotheses bolster these findings, including an explicit consideration of the gene losses implied by alternate topologies. In situ hybridization studies of 20 Hox-related genes reveal that multiple Hox genes are expressed in distinct regions along the primary body axis, supporting the existence of a pre-bilaterian Hox code. Additionally, several Hox genes are expressed in nested domains along the secondary body axis, suggesting a role in “dorsoventral” patterning. CONCLUSIONS/SIGNIFICANCE: A cluster of anterior and posterior Hox genes, as well as ParaHox cluster of genes evolved prior to the cnidarian-bilaterian split. There is evidence to suggest that these clusters were formed from a series of tandem gene duplication events and played a role in patterning both the primary and secondary body axes in a bilaterally symmetrical common ancestor. Cnidarians and bilaterians shared a common ancestor some 570 to 700 million years ago, and as such, are derived from a common body plan. Our work reveals several conserved genetic components that are found in both of these diverse lineages. This finding is consistent with the hypothesis that a set of developmental rules established in the common ancestor of cnidarians and bilaterians is still at work today