RRS James Cook Cruise JC191 19 January - 1 March 2020 Hydrographic sections from the Florida Straits to the Canaries Current across 24ºN in the Atlantic Ocean

A hydrographic section across the North Atlantic Ocean at a nominal latitude of 24°N was occupied by the RRS James Cook (cruise identifier: JC191) from 19 January to 1 March, 2020. The ship departed from Port Everglades, USA, completing a total of 135 CTD stations over the Florida Straits, the western basin, Mid-Atlantic Ridge, eastern basin and eastern boundary up to Morocco, before ending the cruise in Santa Cruz de Tenerife, Spain. The main objectives of the JC191 research expedition was to collect/measure physical-, chemical-, and biological-ocean data with the purpose of estimating heat, freshwater and carbon budgets on low frequency time scales. All CTD stations had measurements from a CTD rosette equipped with temperature, conductivity, pressure, oxygen sensors, in addition to water captured from 24 niskin bottles fired at varying intervals throughout the full depth water column. The water from the niskin bottles was analysed for dissolved oxygen, carbon (DIC/TA), nutrients, and conductivity. Water for methane (CH4), C14, C13, and pigments (filtered) was collected for onshore analysis. The CTD rosette was also equipped with 2 RBR loggers measuring conductivity, temperature and pressure (up to 6,000m), and a lowered Acoustic Doppler Current Profiler (LADCP) making full depth velocity measurements. The 135 CTD stations include 2 carbon blank stations, and 2 bulk water stations for incubations. In addition to the CTD stations, the RRS James Cook has an underway system, which includes an intake for surface water to be pumped into the water bottle annex and the deck lab; two vessel mounted ADCPs (VMADCPs). A thermosalinograph and a fluorometer, installed in the water bottle annex, continually recorded conductivity, temperature and fluorescence. Water from the CTD was collected to calibrate the ship’s underway TSG. The VMADCPs, 75Hz and 150HZ, mounted on the drop keel record ocean velocities in roughly the top 300- and 600-m, respectively. Surface carbon and methane measurements were also recorded from the underway systems, and surface meteorological variables were monitored via the meteorological sampling system and the pumped water underway system. Finally bathymetric data were recorded an EA640 echosounder and a Kongsberg EM122 multibeam, both of which are mounted on the ship’s hull. Last, 5 Deep Apex Argo floats measuring conductivity, temperature, pressure and oxygen (except for one float not equipped with an optode) were deployed in the western basin. Many of the science party also engaged in extensive outreach via blogs and social media, heightening visibility of the science teams activities to the oceanographic community and the general public. This report summarises the data collected and analysed, and the methodology used for the acquisition and processing of the data onboard the James Cook during the JC191 research expedition

Bottom-Up versus Top-Down Induction of Sleep by Zolpidem Acting on Histaminergic and Neocortex Neurons

Zolpidem, a GABAA receptor-positive modulator, is the gold-standard drug for treating insomnia. Zolpidem prolongs IPSCs to decrease sleep latency and increase sleep time, effects that depend on α2 and/or α3 subunit-containing receptors. Compared with natural NREM sleep, zolpidem also decreases the EEG power, an effect that depends on α1 subunit-containing receptors, and which may make zolpidem-induced sleep less optimal. In this paper, we investigate whether zolpidem needs to potentiate only particular GABAergic pathways to induce sleep without reducing EEG power. Mice with a knock-in F77I mutation in the GABAA receptor γ2 subunit gene are zolpidem-insensitive. Using these mice, GABAA receptors in the frontal motor neocortex and hypothalamic (tuberomammillary nucleus) histaminergic-neurons of γ2I77 mice were made selectively sensitive to zolpidem by genetically swapping the γ2I77 subunits with γ2F77 subunits. When histamine neurons were made selectively zolpidem-sensitive, systemic administration of zolpidem shortened sleep latency and increased sleep time. But in contrast to the effect of zolpidem on wild-type mice, the power in the EEG spectra of NREM sleep was not decreased, suggesting that these EEG power-reducing effects of zolpidem do not depend on reduced histamine release. Selective potentiation of GABAA receptors in the frontal cortex by systemic zolpidem administration also reduced sleep latency, but less so than for histamine neurons. These results could help with the design of new sedatives that induce a more natural sleep

Economic removal of chlorophenol from wastewater using multi-stage spiral-wound reverse osmosis process: simulation and optimisation

YesThe successful use of Reverse Osmosis (RO) process has increased significantly in water desalination, water treatment and food processing applications. In this work, the economic feasibility of a multi-stage RO process including both retentate and permeate reprocessing for the removal of chlorophenol from wastewater is explored using simulation and optimisation studies. Firstly, a mathematical model of the process is developed based on the solution diffusion model, which was validated using experimental chlorophenol removal from the literature, is combined with several appropriate cost functions to form a full model package. Secondly, for a better understanding of the interactions between the different parameters on the economic performance of the process, a detailed process simulation is carried out. Finally, a multi-objective optimisation framework based on Non-Linear Programming (NLP) problem is developed for minimising the product unit cost, the total annualised cost, the specific energy consumption together with optimising the feed pressure and feed flow rate for an acceptable level of chlorophenol rejection and total water recovery rate. The results clearly show that the removal of chlorophenol can reach 98.8% at a cost of approximately 0.21 $/m³

RRS James Cook Cruise JC159 28 February - 11 April 2018. Hydrographic sections from the Brazil to the Benguela Current across 24S in the Atlantic

A Hydrographic section was occupied at a nominal latitude of 24°S in the Atlantic Ocean during March and April 2018 on Cruise JC159 of RRS James Cook. The primary objective of this cruise was to measure ocean physical, chemical and biological parameters in order to establish regional budgets of heat, freshwater and carbon, and to infer decadal variability. In addition, 371 Niskin Bottles were sampled for microplastics, reflecting increasing awareness of plastics pollution in the oceans. A total of 121 CTD/LADCP stations were conducted, including one test station and two CFC bottle blank stations. In addition to temperature, salinity and oxygen profiles from the sensors on the CTD package, water samples from a 24 x 20 litre rosette were analysed for the following parameters at all stations: salinity; dissolved oxygen; inorganic nutrients; alkalinity and dissolved inorganic carbon; CFCs. Samples were collected for shore analysis for oxygen and carbon isotopes (del-18O, del13C and del-14C). Samples were collected and filtered for pigments (shore analysis) at 44 stations and for microplastics at 45 stations. 8 Argo floats were deployed, including two Bio-PROVOR floats and 2 Deep ARVORs. In addition, samples were collected from the ships’ underway system to calibrate and compliment the data continually collected by the TSG (thermosalinograph). Full depth velocity measurements were made at every station by LADCP (Lowered Acoustic Doppler Current Profiler) mounted on the frame of the rosette. Throughout the cruise, velocity data in the upper few hundred metres of the water column were collected by the ship’s VMADCP (Vessel Mounted Acoustic Doppler Current Profiler) transducers (75Hz and 150Hz) mounted on one of the two drop keels. Meteorological variables were monitored using the onboard surface water and meteorological sampling system (SURFMET). Bathymetric data were collected using the Kongsberg EM122 multibeam system and the EA640 echo sounder. This report describes the methods used to acquire and process the data on board the ship during cruise JC159

Self-assembled peptide habitats to model tumor metastasis

Metastatic tumours are complex ecosystems; a community of multiple cell types, including cancerous cells, fibroblasts, and immune cells that exist within a supportive and specific microenvironment. The interplay of these cells, together with tissue specific chemical, structural and temporal signals within a three-dimensional (3D) habitat, direct tumour cell behavior, a subtlety that can be easily lost in 2D tissue culture. Here, we investigate a significantly improved tool, consisting of a novel matrix of functionally programmed peptide sequences, self-assembled into a scaffold to enable the growth and the migration of multicellular lung tumour spheroids, as proof-of-concept. This 3D functional model aims to mimic the biological, chemical, and contextual cues of an in vivo tumor more closely than a typically used, unstructured hydrogel, allowing spatial and temporal activity modelling. This approach shows promise as a cancer model, enhancing current understandings of how tumours progress and spread over time within their microenvironment. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

A Poincar\'e-Birkhoff theorem for tight Reeb flows on S3S^3

We consider Reeb flows on the tight $3$-sphere admitting a pair of closed orbits forming a Hopf link. If the rotation numbers associated to the transverse linearized dynamics at these orbits fail to satisfy a certain resonance condition then there exist infinitely many periodic trajectories distinguished by their linking numbers with the components of the link. This result admits a natural comparison to the Poincar\'e-Birkhoff theorem on area-preserving annulus homeomorphisms. An analogous theorem holds on $SO(3)$ and applies to geodesic flows of Finsler metrics on $S^2$.Comment: 67 pages. To appear in Inventiones Mathematica