Freshwater displacement effect on the Weddell Gyre carbon budget

This work was funded by NSF's Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) Project under NSF awards PLR-1425989 and OPP-1936222. G.A.M was additionally supported under UKRI Grant MR/W013835/1. M.R.M. also acknowledges support from NASA grant 80NSSC20K1076 and NSF grants OCE-1924388 and OPP-2149501.The Weddell Gyre mediates carbon exchange between the abyssal ocean and atmosphere, which is critical to global climate. This region also features large and highly variable freshwater fluxes due to seasonal sea ice, net precipitation, and glacial melt; however, the impact of these freshwater fluxes on the regional carbon cycle has not been fully appreciated. Using a novel budget analysis of dissolved inorganic carbon (DIC) mass in the Biogeochemical Southern Ocean State Estimate, we highlight two freshwater-driven transports. Where freshwater with minimal DIC enters the ocean, it displaces DIC-rich seawater outwards, driving a lateral transport of 75 ± 5 Tg DIC/year. Additionally, sea ice export requires a compensating import of seawater, which carries 48 ± 11 Tg DIC/year into the gyre. Though often overlooked, these freshwater displacement effects are of leading order in the Weddell Gyre carbon budget in the state estimate and in regrouped box-inversion estimates, with implications for evaluating basin-scale carbon transport.Publisher PDFPeer reviewe

Extending the Functionality of Behavioural Change-Point Analysis with k-Means Clustering: A Case Study with the Little Penguin (Eudyptula minor)

We present a simple framework for classifying mutually exclusive behavioural states within the geospatial lifelines of animals. This method involves use of three sequentially applied statistical procedures: (1) behavioural change point analysis to partition movement trajectories into discrete bouts of same-state behaviours, based on abrupt changes in the spatiotemporal autocorrelation structure of movement parameters; (2) hierarchical multivariate cluster analysis to determine the number of different behavioural states; and (3) k-means clustering to classify inferred bouts of same-state location observations into behavioural modes. We demonstrate application of the method by analysing synthetic trajectories of known ‘artificial behaviours’ comprised of different correlated random walks, as well as real foraging trajectories of little penguins (Eudyptula minor) obtained by global-positioning-system telemetry. Our results show that the modelling procedure correctly classified 92.5% of all individual location observations in the synthetic trajectories, demonstrating reasonable ability to successfully discriminate behavioural modes. Most individual little penguins were found to exhibit three unique behavioural states (resting, commuting/active searching, arearestricted foraging), with variation in the timing and locations of observations apparently related to ambient light, bathymetry, and proximity to coastlines and river mouths. Addition of k-means clustering extends the utility of behavioural change point analysis, by providing a simple means through which the behaviours inferred for the location observations comprising individual movement trajectories can be objectively classified

Psip1/Ledgf p75 restrains<i>Hox</i>gene expression by recruiting both trithorax and polycomb group proteins

Trithorax and polycomb group proteins are generally thought to antagonize one another. The trithorax familymember MLL (myeloid/lymphoid or mixedlineage leukemia) is presumed to activate Hox expression, counteracting polycomb-mediated repression. PC4 and SF2 interacting protein 1 (PSIP1)/p75, also known as LEDGF, whose PWWP domain binds to H3K36me3, interacts with MLL and tethers MLL fusion proteins toHOXA9 in leukaemias. Here we show, unexpectedly, that Psip1/p75 regulates homeotic genes by recruiting not only MLL complexes, but also the polycomb group protein Bmi1. In Psip1-/- cells binding of Mll1/2, Bmi1 and the co-repressor Ctbp1 at Hox loci are all abrogated and Hoxa and Hoxd mRNA expression increased. Our data not only reveal a potential mechanism of action for Psip1 in the regulation of Hox genes but also suggest an unexpected interplay between proteins usually considered as transcriptional activators and repressors. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research

A prediction model for colon cancer surveillance data

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112258/1/sim6500-sup-0001-Supplementary1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112258/2/sim6500.pd

Structural and mechanistic mapping of a unique fumarate reductase

The 1.8 Å resolution crystal structure of the tetraheme flavocytochrome c3, Fcc3, provides the first mechanistic insight into respiratory fumarate reductases or succinate dehydrogenases. The multi-redox center, three-domain protein shows a 40 Å long ‘molecular wire’ allowing rapid conduction of electrons through a new type of cytochrome domain onto the active site flavin, driving the reduction of fumarate to succinate. In this structure a malate-like molecule is trapped in the enzyme active site. The interactions between this molecule and the enzyme suggest a clear mechanism for fumarate reduction in which the substrate is polarized and twisted, facilitating hydride transfer from the reduced flavin and subsequent proton transfer. The enzyme active site in the oxidized form is completely buried at the interface between the flavin-binding and the clamp domains. Movement of the cytochrome and clamp domains is postulated to allow release of the product

Pharmacokinetic and pharmacodynamic modelling after subcutaneous, intravenous and buccal administration of a high-concentration formulation of buprenorphine in conscious cats

The aim of this study was to describe the joint pharmacokinetic-pharmacodynamic model and evaluate thermal antinociception of a high-concentration formulation of buprenorphine (Simbadol™) in cats

In vivo imaging of hepatic neutrophil migration in severe alcoholic hepatitis with 111In-radiolabelled leucocytes.

The study's aim was to image severe alcoholic hepatitis (SAH) using 111In-labelled leucocytes with two objectives in mind: firstly for non-invasive diagnosis and secondly to provide a platform for experimental therapies aiming to inhibit intrahepatic neutrophil migration. 111In-leucocyte scintigraphy was performed 30 min and 24 h post-injection in 19 patients with SAH, 14 abstinent patients with alcohol-related cirrhosis and 11 normal controls. Eleven with SAH and seven with cirrhosis also had 99mTc-nanocolloid scintigraphy. Change in hepatic 111In radioactivity was expressed as decay-corrected 24 h:30 min count ratio and, in SAH, compared with histological grading of steatohepatitis and expression of granulocyte marker, CD15. Hepatic microautoradiography on biopsy specimens obtained 24 h post-injection of 111In-leucocytes was performed in one patient. Median 24 h:30 min hepatic 111In activity ratio was higher in SAH (2.5 (interquartile range (IQR): 1.7-4.0) compared with cirrhotics and normal controls (1.0 (0.8-1.1) and 0.8 (0.7-0.9) respectively, P<0.0001). In SAH, it correlated with CD15 expression (r = 0.62, P=0.023) and was higher in marked compared with mild/moderate steatohepatitis (4.0 (3.0-4.6) compared with 1.8 (1.5-2.6), P=0.006). Hepatic-to-splenic 99mTc count rate ratio was reduced in SAH (0.5 (0.4-1.4)) compared with cirrhotics (2.3( 0.6-3.0)) and three historic normal controls (4.2 (3.8-5.0); P=0.003), consistent with impaired hepatic reticuloendothelial function. Scintigraphic findings in SAH included prominent lung radioactivity at 30 min, likely the result of neutrophil primimg. Microautoradiography demonstrated cell-associated 111In in areas of parenchymal neutrophil infiltration. In conclusion, 111In-leucocyte scintigraphy can non-invasively diagnose SAH and could provide a platform for evaluation of novel treatments aiming to inhibit intrahepatic neutrophil migration.The study was funded by a project grant from Brighton and Sussex Medical Schoo

Increasing navigation speed at endoluminal CT colonography reduces colonic visualization and polyp identification

Purpose: To investigate the effect of increasing navigation speed on the visual search and decision making during polyp identification for computed tomography (CT) colonography. Materials and Methods: Institutional review board permission was obtained to use deidentified CT colonography data for this prospective reader study. After obtaining informed consent from the readers, 12 CT colonography fly-through examinations that depicted eight polyps were presented at four different fixed navigation speeds to 23 radiologists. Speeds ranged from 1 cm/sec to 4.5 cm/sec. Gaze position was tracked by using an infrared eye tracker, and readers indicated that they saw a polyp by clicking a mouse. Patterns of searching and decision making by speed were investigated graphically and by multilevel modeling. Results: Readers identified polyps correctly in 56 of 77 (72.7%) of viewings at the slowest speed but in only 137 of 225 (60.9%) of viewings at the fastest speed (P = .004). They also identified fewer false-positive features at faster speeds (42 of 115; 36.5%) of videos at slowest speed, 89 of 345 (25.8%) at fastest, P = .02). Gaze location was highly concentrated toward the central quarter of the screen area at faster speeds (mean gaze points at slowest speed vs fastest speed, 86% vs 97%, respectively). Conclusion: Faster navigation speed at endoluminal CT colonography led to progressive restriction of visual search patterns. Greater speed also reduced both true-positive and false-positive colorectal polyp identification

A poly(urethane)-encapsulated benzo[2,3-d:6,7-d']diimidazole organic down-converter for green hybrid LEDs

The development of organic down-converting materials continues to attract attention in hybrid LED technology by obviating the need for non-sustainable rare-earth elements. In this work, a benzodiimidazole-based system (TPA-BDI) has been employed as a down-converting layer in a hybrid organic-inorganic LED device. A commercially available poly(urethane)-based resin is used as the encapsulating material, providing a dilute layer of TPA-BDI that is deposited on top of the GaN-based LED. Crucially, the solution-state emissive performance is generally maintained when encapsulated at low concentrations within this resin. A maximum luminous efficacy of 87 lm W -1 was demonstrated using a 1.0 mg ml -1 concentration of TPA-BDI in the resin. The suitability of using organic down-converters to produce green light from hybrid devices was demonstrated by the excellent repeatability of the device characteristics across a series of encapsulated LEDs

Overlap between flesh-footed shearwater <i>Puffinus</i> <i>carneipes</i> foraging areas and commercial fisheries in New Zealand waters

On page 250, the text erroneously states (in reference to flesh-footed shearwaters): 'A world population of ca. 740000 pairs was estimated by Lavers (2015) following recent Australian surveys.' The correct value is 74000 pairs