Stacking Interactions Drive Selective Self-Assembly and Self-Sorting of Pyrene-Based M(II)4L6 Architectures.

Subcomponent self-assembly of two isomeric bis(3-aminophenyl)pyrenes, 2-formylpyridine and the metal ions Fe(II), Co(II), and Zn(II) led to the formation of two previously unidentified structure types: a C2-symmetric M(II)4L6 assembly with meridionally coordinated metal centers, and a C3-symmetric self-included M(II)4L6 assembly with facially coordinated metal centers. In both structures the meta linkages within the ligands facilitate π-stacking between the pyrene panels of the ligands. A C2h-symmetric M(II)2L2 box was also obtained, which was observed to selectively bind electron-deficient aromatic guests between two parallel pyrene subunits. Similar donor-acceptor interactions drove the selective self-assembly of a singular M(II)4L4L'2 architecture incorporating both a pyrene-containing diamine and an electron-deficient NDI-based diamine. This heteroleptic architecture was shown to be thermodynamically favored over the corresponding homoleptic M(II)4L6 and M(II)4L'6 complexes, which were nonetheless stable in each others' absence. By contrast, an isomeric pyrene-based diamine was observed to undergo narcissistic self-sorting in the presence of the NDI-based diamine.This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC). D.A.R. acknowledges the Gates Cambridge Trust for Ph.D. funding (Gates Cambridge Scholarship). We thank the EPSRC Mass Spectrometry Service at Swansea for carrying out the high resolution mass spectrometry and Diamond Light Source (UK) for synchrotron beamtime on I19 (MT8464). We also thank the NMR service team at the Department of Chemistry, University of Cambridge for performing some NMR experiments.This is the final version of the article. It first appeared from the American Chemical Society via http://dx.doi.org/10.1021/jacs.5b0992

A new, long-term daily satellite-based rainfall dataset for operational monitoring in Africa

Rainfall information is essential for many applications in developing countries, and yet, continually updated information at fine temporal and spatial scales is lacking. In Africa, rainfall monitoring is particularly important given the close relationship between climate and livelihoods. To address this information gap, this paper describes two versions (v2.0 and v3.0) of the TAMSAT daily rainfall dataset based on high-resolution thermal-infrared observations, available from 1983 to the present. The datasets are based on the disaggregation of 10-day (v2.0) and 5-day (v3.0) total TAMSAT rainfall estimates to a daily time-step using daily cold cloud duration. This approach provides temporally consistent historic and near-real time daily rainfall information for all of Africa. The estimates have been evaluated using ground-based observations from five countries with contrasting rainfall climates (Mozambique, Niger, Nigeria, Uganda, and Zambia) and compared to other satellite-based rainfall estimates. The results indicate that both versions of the TAMSAT daily estimates reliably detects rainy days, but have less skill in capturing rainfall amount—results that are comparable to the other datasets

Cognitive Information Processing

Contains research objectives and reports on five research projects.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 36-039-AMC-03200(E)National Science Foundation (Grant GK-835)National Institutes of Health (Grant 2 P01 MH-04737-06)National Aeronautics and Space Administration (Grant NsG 496

‘Re-reading Raphael Samuel: Politics, Personality and Performance’

For British historian Raphael Samuel, history and politics were inextricable. Best known as the founder of the history workshop movement, the controversial historian took his stance on the democratisation of history-making, becoming an outspoken advocate for public history. Despite making a significant contribution to contemporary historiography, he remains a neglected, even disparaged, figure. This paper contends that the most significant aspect of Samuel’s historical work was not one or other theory of history or argument about the past but his entire way of being an historian. Samuel embodied as much as expressed his ideas, consciously using his personality as a powerful political tool. It is further argued that conventional approaches to intellectual history, focusing on textual outputs, do not fully recognise the significance of performative modes of thinking. Theoretical approaches to performance as identity offer important insight here but can be too schematic in their view of applied and enacted thought. A biographical approach, by contrast, provides the intimate perspective necessary to fully appreciate the fluidity and complexity of such a personality. The paper first situates Samuel in the context of his earlier life, focusing on how and why he created such a public persona and how he adapted it in response to changing circumstances. It then considers the implications and effectiveness of this persona by assessing how it was perceived and narrated by others, acknowledging, in the process, why different groups engaged with and interpreted it differently

Strong armies, slow adaptation: civil-military relations and diffusion of military power

Why are some states more willing to adopt military innovations than others? Why, for example, were the great powers of Europe able to successfully reform their military practices to better adapt to and participate in the so-called military revolution of the sixteenth and seventeenth centuries while their most important extra-European competitor, the Ottoman Empire, failed to do so? This puzzle is best explained by two factors: civil-military relations and historical timing. In the Ottoman Empire, the emergence of an institutionally strong and internally cohesive army during the early stages of state formation—in the late fourteenth century—equipped the military with substantial bargaining powers. In contrast, the great powers of Europe drew heavily on private providers of military power during the military revolution and developed similar armies only by the second half of the seventeenth century, limiting the bargaining leverage of European militaries over their rulers. In essence, the Ottoman standing army was able to block reform efforts that it believed challenged its parochial interests. Absent a similar institutional challenge, European rulers initiated military reforms and motivated officers and military entrepreneurs to participate in the ongoing military revolution

From mood to movement: English nationalism, the European Union and taking back control

This article considers whether the 2016 EU referendum can be perceived as an English nationalist movement. Specifically, attention is given to examining how memories of the former British Empire were nostalgically enveloped in anxieties regarding England’s location within the devolved UK state. The comments and work of Enoch Powell and George Orwell are used to help explore the link between nostalgia and anxiety in accounts of English nationalism. Despite their opposing political orientations, when considered together, it is argued that both men provide a unique cross-political perspective on Englishness, empire and nostalgia. By way of exploring these themes in relation to the EU referendum, Aughey’s assertion that English nationalism can be perceived as both a ‘mood’ and ‘movement’ is used to highlight how a sense of English anxiety regarding its lack of national sovereignty (mood), as well as a desire to reclaim this sovereignty by renegotiating trade relations with the ‘Anglo-sphere’ (movement), were conjoined in the popular referendum slogan, ‘take back control’. In conclusion, it is argued that the contextualization of the referendum can be predicated upon an orientation to empire that steers away from glorifying pro-imperial images of England/Britain, towards a more positive and progressive appropriation of the EU referendum as a statement of national change and belonging

Modelling Hepatic Endoderm Development: Highly Efficient Differentiation of Human Embryonic Stem Cells to Functional Hepatic Endoderm Requires ActivinA and Wnt3a Signalling.

Human embryonic stem cells (hESCs) are a valuable source of pluripotential primary cells. However, their homogeneous cellular differentiation to specific cell types _in vitro_ has proven difficult thus far. Wnt signalling has been shown to play important roles in coordinating development and we demonstrate that Wnt3a is differentially expressed at critical stages of human liver development _in vivo_. The essential role of Wnt3a in hepatocyte differentiation from hESCs is paralleled by our _in vitro_ model, demonstrating the importance of a physiological approach to cellular differentiation. Our studies provide compelling evidence that Wnt3a signaling is important for coordinated hepato-cellular function _in vitro_ and _in vivo_. In addition, we demonstrate Wnt3a facilitates clonal plating of hESCs capable of hepatic endoderm differentiation. These studies represent an important step forward toward the use of hESC-derived hepatocytes in biomedical applications and has opened the door to high through-put metabolic analysis of human liver function