Observations of sea ice and icebergs from satellite radar altimeters

Satellite radar altimeters can make useful contributions to the study of sea ice both by enhancing observations from other instruments and by providing a unique probe of ocean-ice interaction in the Marginal Ice Zone (MIZ). The problems, results and future potential of such observations are discussed

Fluid and heat flow in tubes of arbitrary cross-section

Imperial Users onl

Our Moment of Truth: The Social Contract Realized?

Much has changed in the two decades since I (JL) proposed that scientists should re-examine their obligations to society in order to serve society better. Today, more environmental scientists are actively sharing their science broadly, conducting use-inspired science (sensu Stokes) in addition to basic science, engaging with society, and crafting solutions to problems not just diagnosing them—all very welcome and exciting developments. For the most part, however, environmental scientists have taken on these extra duties because they believed it was the right thing to do and despite the considerable impediments that exist within academia. But make no mistake, the culture of academia continues to impede progress. As a result, although the above actions have had demonstrable effect, their collective impact falls far short of what is needed if society is to tackle effectively the disruption underway due to climate change, ocean acidification, biodiversity loss, pandemics, and more. Actions by individuals can take us only so far. To truly help society meet its grand challenges, environmental scientists must now make a quantum leap in engagement with society. It is time for strategic, collective action to change the culture of academia and create the enabling conditions for science to serve society better

Want to block earworms from conscious awareness? B(u)y gum!

Three experiments examine the role of articulatory motor planning in experiencing an involuntary musical recollection (an “earworm”). Experiment 1 shows that interfering with articulatory motor programming by chewing gum reduces both the number of voluntary and the number of involuntary—unwanted—musical thoughts. This is consistent with other findings that chewing gum interferes with voluntary processes such as recollections from verbal memory, the interpretation of ambiguous auditory images, and the scanning of familiar melodies, but is not predicted by theories of thought suppression, which assume that suppression is made more difficult by concurrent tasks or cognitive loads. Experiment 2 shows that chewing the gum affects the experience of “hearing” the music and cannot be ascribed to a general effect on thinking about a tune only in abstract terms. Experiment 3 confirms that the reduction of musical recollections by chewing gum is not the consequence of a general attentional or dual-task demand. The data support a link between articulatory motor programming and the appearance in consciousness of both voluntary and unwanted musical recollections

Tunable control of the hydrophilicity and wettability of conjugated polymers by a postpolymerization modification approach.

A facile method to prepare hydrophilic polymers by a postpolymerization nucleophillic aromatic substitution reaction of fluoride on an emissive conjugated polymer (CP) backbone is reported. Quantitative functionalization by a series of monofunctionalized ethylene glycol oligomers, from dimer to hexamer, as well as with high molecular weight polyethylene glycol is demonstrated. The length of the ethylene glycol sidechains is shown to have a direct impact on the surface wettability of the polymer, as well as its solubility in polar solvents. However, the energetics and band gap of the CPs remain essentially constant. This method therefore allows an easy way to modulate the wettability and solubility of CP materials for a diverse series of applications

Mechanism and function of Vav1 localisation in TCR signalling

The antigen-specific binding of T cells to antigen presenting cells results in recruitment of signalling proteins to microclusters at the cell-cell interface known as the immunological synapse (IS). The Vav1 guanine nucleotide exchange factor plays a critical role in T cell antigen receptor (TCR) signalling, leading to the activation of multiple pathways. We now show that it is recruited to microclusters and to the IS in primary CD4+ and CD8+ T cells. Furthermore, we show that this recruitment depends on the SH2 and C-terminal SH3 (SH3B) domains of Vav1, and on phosphotyrosines 112 and 128 of the SLP76 adaptor protein. Biophysical measurements show that Vav1 binds directly to these residues on SLP76 and that efficient binding depends on the SH2 and SH3B domains of Vav1. Finally, we show that the same two domains are critical for the phosphorylation of Vav1 and its signalling function in TCR-induced calcium flux. We propose that Vav1 is recruited to the IS by binding to SLP76 and that this interaction is critical for the transduction of signals leading to calcium flux