Rapid water transport by long-lasting modon eddy pairs in the southern midlatitude oceans

Water in the ocean is generally carried with the mean flow, mixed by eddies, or transported westward by coherent eddies at speeds close to the long baroclinic Rossby wave speed. Modons (dipole eddy pairs) are a theoretically predicted exception to this behaviour, which can carry water to the east or west at speeds much larger than the Rossby wave speed, leading to unusual transports of heat, nutrients and carbon. We provide the first observational evidence of such rapidly moving modons propagating over large distances. These modons are found in the midlatitude oceans around Australia, with one also seen in the South Atlantic west of the Agulhas region. They can travel at more than ten times the Rossby wave speed of 1–2 cm s^−1, and typically persist for about six months carrying their unusual water mass properties with them, before splitting into individual vortices which can persist for many months longer

Body Temperature of the Loggerhead Sea Turtle Caretta Caretta and the Leatherback Sea Turtle Dermochelys Coriacea During Nesting

Body temperatures of loggerhead and leatherback turtles recorded during nesting excursions were found to be greater than sea temperatures. Leatherback turtles exhibited greater temperature differentials (5,3 - 6,25°C) than loggerhead turtles (1,9 - 3,22°C).The possibility that leatherback turtles may have a preferred temperature range (30 - 32°C) as is the case in terrestrial chelonians is discussed. Recordings of exhaled air temperatures suggest that leather-back turtles may employ a countercurrent heat exchange system in the nares in order to conserve body heat

Systems Scenarios: A tool for facilitating the socio-technical design of work systems

The socio-technical systems approach to design is well documented. Recognising the benefits of this approach, organisations are increasingly trying to work with systems, rather than their component parts. However, few tools attempt to analyse the complexity inherent in such systems, in ways that generate useful, practical outputs. In this paper, we outline the ‘System Scenarios Tool’ (SST), which is a novel, applied methodology that can be used by designers, end-users, consultants or researchers to help design or re-design work systems. The paper introduces the SST using examples of its application, and describes the potential benefits of its use, before reflecting on its limitations. Finally, we discuss potential opportunities for the tool, and describe sets of circumstances in which it might be used

A strategy for integrating essential three-dimensional microphysiological systems of human organs for realistic anticancer drug screening

Cancer is one of the leading causes of morbidity and mortality around the world. Despite some success, traditional anticancer drugs developed to reduce tumor growth face important limitations primarily due to undesirable bone marrow and cardiovascular toxicity. Many drugs fail in clinical development after showing promise in preclinical trials, suggesting that the available in vitro and animal models are poor predictors of drug efficacy and toxicity in humans. Thus, novel models that more accurately mimic the biology of human organs are necessary for high-throughput drug screening. Three-dimensional (3D) microphysiological systems can utilize induced pluripotent stem cell technology, tissue engineering, and microfabrication techniques to develop tissue models of human tumors, cardiac muscle, and bone marrow on the order of 1 mm3 in size. A functional network of human capillaries and microvessels to overcome diffusion limitations in nutrient delivery and waste removal can also nourish the 3D microphysiological tissues. Importantly, the 3D microphysiological tissues are grown on optically clear platforms that offer non-invasive and non-destructive image acquisition with subcellular resolution in real time. Such systems offer a new paradigm for high-throughput drug screening and will significantly improve the efficiency of identifying new drugs for cancer treatment that minimize cardiac and bone marrow toxicity

A hydrostatic pressure-driven passive micropump enhanced with siphon-based autofill function.

Autonomous and self-powered micropumps are in critical demand for versatile cell- and tissue-based applications as well as for low-cost point-of-care testing (POCT) in microfluidics fields. The hydrostatic pressure-driven passive micropumps are simple and widely used, but they cannot maintain steady and continuous flow for long periods of time. Here, we propose a hydrostatic pressure-driven passive micropump enhanced with siphon-based autofill function, which can realize the autonomous and continuous perfusion with well-controlled steady flow over an extended time without electric power consumption. The characterization results reveal that both the cycle number in one refilling loop and the siphon diameter will affect the refilling time. Furthermore, this micropump also enables multiplexed medium delivery under either the same or different flow conditions with high flexibility. The system was validated using an in vitro vasculogenesis model over the course of several days. Most importantly, the device can consistently provide steady medium perfusion for up to 5 days at a predefined hydrostatic pressure drop without the need for supplemental medium changes. We believe that this hydrostatic pressure-driven passive micropump will become a critical module for a broad range of sophisticated microfluidic operations and applications

Weighing the ocean with bottom-pressure sensors: robustness of the ocean mass annual cycle estimate

Abstract. We use ocean bottom pressure measurements from 17 tropical sites to determine the annual cycle of ocean mass. We show that such a calculation is robust, and use three methods to estimate errors in the mass determination. Our final best estimate, using data from the best sites and two ocean models, is that the annual cycle has an amplitude of 0.85 mbar (equivalent to 8.4 mm of sea level, or 3100 Gt of water), with a 95% chance of lying within the range 0.61–1.17 mbar. The time of the peak in ocean mass is 10 October, with 95% chance of occuring between 21 September and 25 October. The simultaneous fitting of annual ocean mass also improves the fitting of bottom pressure instrument drift. </jats:p

Antarctic Circumpolar Transport and the Southern Mode: a model investigation of interannual to decadal time scales

Abstract. It is well-established that, at periods shorter than a year, variations in Antarctic Circumpolar Transport are reflected in a barotropic mode, known as the Southern Mode, in which sea level and bottom pressure varies coherently around Antarctica. Here, we use two multidecadal ocean model runs to investigate the behaviour of the Southern Mode at time scales on which density changes become important, leading to a baroclinic component to the adjustment. We find that the concept of a Southern Mode in bottom pressure remains valid, and remains a direct measure of the circumpolar transport, with changes at the northern boundary playing only a small role even on decadal time scales. However, at periods longer than about 5 yr, density changes start to play a role, leading to a surface intensification of the vertical profile of the transport. We also find that barotropic currents on the continental slope account for a significant fraction of the variability, and produce surface intensification in the meridional-integral flow. The role of density variations results in a sea level signal which, although reflecting transport changes at all time scales, has a ratio of sea level to transport which becomes larger at longer time scales. This means that any long-term transport monitoring strategy based on present measurement systems must involve multiplying the observed quantity by a factor which depends on frequency. </jats:p

Gravitational waves from merging compact binaries

Largely motivated by the development of highly sensitive gravitational-wave detectors, our understanding of merging compact binaries and the gravitational waves they generate has improved dramatically in recent years. Breakthroughs in numerical relativity now allow us to model the coalescence of two black holes with no approximations or simplifications. There has also been outstanding progress in our analytical understanding of binaries. We review these developments, examining merging binaries using black hole perturbation theory, post-Newtonian expansions, and direct numerical integration of the field equations. We summarize these approaches and what they have taught us about gravitational waves from compact binaries. We place these results in the context of gravitational-wave generating systems, analyzing the impact gravitational wave emission has on their sources, as well as what we can learn about them from direct gravitational-wave measurements.Comment: 90 pages, 12 figures. Invited review to appear in Annual Reviews of Astronomy and Astrophysics. Further minor tweaks in response to reader feedbac

Adolescents’ responses to the promotion and flavouring of e-cigarettes

Objectives The purpose of the study is to examine adolescents’ awareness of e-cigarette marketing and investigate the impact of e-cigarette flavour descriptors on perceptions of product harm and user image. Methods Data come from the 2014 Youth Tobacco Policy Survey, a cross-sectional in-home survey conducted with 11–16 year olds across the UK (n = 1205). Adolescents’ awareness of e-cigarette promotion, brands, and flavours was assessed. Perceptions of product harm, and likely user of four examples of e-cigarette flavours was also examined. Results Some participants had tried e-cigarettes (12 %) but regular use was low (2 %) and confined to adolescents who had also smoked tobacco. Most were aware of at least one promotional channel (82 %) and that e-cigarettes came in different flavours (69 %). Brand awareness was low. E-cigarettes were perceived as harmful (M = 3.54, SD = 1.19) but this was moderated by product flavours. Fruit and sweet flavours were perceived as more likely to be tried by young never smokers than adult smokers trying to quit (p < 0.001). Conclusions There is a need to monitor the impact of future market and regulatory change on youth uptake and perceptions of e-cigarettes

Effect of a multicomponent intervention on antihypertensive medication intensification in rural South Asia: post-hoc analysis of a cluster RCT

BACKGROUND: Inadequate treatment of hypertension is a widespread problem, especially in South Asian countries where cardiovascular disease mortality rates are high. We aimed to explore the effect of a multicomponent intervention (MCI) on antihypertensive medication intensification among rural South Asians with hypertension. METHODS: A post-hoc analysis of a two-year cluster-randomized controlled trial including 2645 hypertensives aged≥ 40 years from 30 rural communities, 10 each, in Bangladesh, Pakistan, and Sri Lanka. Independent assessors collected information on participants' self-reports and physical inspection of medications. The main outcomes were the changes from baseline to 24 months in the following: 1) the therapeutic intensity score (TIS) for all (and class specific) antihypertensive medications; 2) the number of antihypertensive medications in all trial participants. RESULTS: At 24 months, the mean increase in the TIS score of all antihypertensive medications was 0.11 in the MCI group and 0.03 in the control group, with a between-group difference in the increase of 0.08 (95% CI (0.03, 0.12); P=0.002). In MCI compared to controls, a greater increase in the TIS of renin angiotensin-aldosterone system blockers (0.05; 95% CI (0.02, 0.07); P<0.001) and calcium channel blockers (0.03; 95% CI (0.00, 0.05);p=0.031) , and in the number of antihypertensive medications (0.11, 95% CI (0.02, 0.19);P=0.016) was observed. CONCLUSIONS: In rural communities in Bangladesh, Pakistan, and Sri Lanka, MCI led to a greater increase in antihypertensive medication intensification compared to the usual care among adults with hypertension. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02657746