Frost jacking of joint blocks above Cwm Idwal, in North Wales

The in situ development of ground ice is a major mechanism in rock breakdown. Where well-jointed rock has been streamlined through glacial abrasion, subsequent growth of subsurface intrusive ice may lead to the uplift of individual blocks and disruption of the ice erosional landform. This jacking' mechanism is likely to be a progressive process. Following climatic change and allied ground ice decay, the degree of subsequent settlement will be controlled by the degree to which individual blocks become wedged against their neighbours. Possibly the first example to be identified in Britain is described here. It dates from a severe phase of periglaciation occurring between the Last Glacial Maximum and the Flandrian Interglacial (c. 22-11.6 ka BP). Where identified in currently temperate regions, frost-jacked blocks may be interpreted as evidence for palaeopermafrost.

Frost jacking of joint blocks above Cwm Idwal, in North Wales

The in situ development of ground ice is a major mechanism in rock breakdown. Where well-jointed rock has been streamlined through glacial abrasion, subsequent growth of subsurface intrusive ice may lead to the uplift of individual blocks and disruption of the ice erosional landform. This jacking' mechanism is likely to be a progressive process. Following climatic change and allied ground ice decay, the degree of subsequent settlement will be controlled by the degree to which individual blocks become wedged against their neighbours. Possibly the first example to be identified in Britain is described here. It dates from a severe phase of periglaciation occurring between the Last Glacial Maximum and the Flandrian Interglacial (c. 22-11.6 ka BP). Where identified in currently temperate regions, frost-jacked blocks may be interpreted as evidence for palaeopermafrost.

Formation of triple helical nanofibers using self-assembling chiral benzene-1,3,5-tricarboxamides and reversal of the nanostructure's handedness using mirror image building blocks

Intertwining triple helical nanofibers with an overall handedness have been formed from self-assembling chiral benzene-1,3,5-tricarboxamides 1, 2 and 3, whereas the achiralbenzene-1,3,5-tricarboxamide 4 upon self-association gives rise to straight nanofibers without any twist and transmission electron microscopy images of chiral compounds clearly demonstrate that the handedness of the triple helical nanofibers can be reversed by using the enantiomeric benzene-1,3,5-tricarboxamide building blocks.

Construction of Helical Nanofibers from Self-Assembling Pseudopeptide Building Blocks: Modulating the Handedness and Breaking the Helicity

Helical nanofibers are successfully constructed from suitable self-assembling pseudopeptide-based molecular building blocks. The handedness of these nanofibers can be reversed by using mirror-imaged pseudopeptide-based building blocks. Straight nanofibers are also constructed by modulating the molecular and supramolecular structures by the proper choice of the stereochemical nature of the molecular scaffolds. This study demonstrates that molecular structure and chirality are not the only determining factors for tuning the morphology and chirality of nanostructures; the nature of the supramolecular structures formed from the corresponding molecular scaffolds also plays a key role in dictating the shape and chirality of nanostructures. Helical nanofibers are suitable templates for fabricating dipeptide-capped gold nanoparticles, indicating a possible use of these nanofibers in the construction of arrays of gold nanoparticles.

Melt structure and its transformation by sequential crystallization of the two blocks within poly(L-lactide)-block-poly(epsilon-caprolactone) double crystalline diblock copolymers

Sequential crystallization of poly(L-lactide) (PLLA) followed by poly(epsilon-caprolactone) (PCL) in double crystalline PLLA-b-PCL diblock copolymers is studied by differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS). Three samples with different compositions are studied. The sample with the shortest PLLA block (32 wt.-% PLLA) crystallizes from a homogeneous melt, the other two (with 44 and 60% PLLA) from microphase separated structures. The microphase structure of the melt is changed as PLLA crystallizes at 122 degrees C (a temperature at which the PCL block is molten) forming spherulites regardless of composition, even with 32% PLLA. SAXS indicates that a lamellar structure with a different periodicity than that obtained in the melt forms (for melt segregated samples). Where PCL is the majority block, PCL crystallization at 42 degrees C following PLLA crystallization leads to rearrangement of the lamellar structure, as observed by SAXS, possibly due to local melting at the interphases between domains. POM results showed that PCL crystallizes within previously formed PLLA spherulites. WAXS data indicate that the PLLA unit cell is modified by crystallization of PCL, at least for the two majority PCL samples. The PCL minority sample did not crystallize at 42 degrees C (well below the PCL homopolymer crystallization temperature), pointing to the influence of pre-crystallization of PLLA on PCL crystallization, although it did crystallize at lower temperature. Crystallization kinetics were examined by DSC and WAXS, with good agreement in general. The crystallization rate of PLLA decreased with increase in PCL content in the copolymers. The crystallization rate of PCL decreased with increasing PLLA content. The Avrami exponents were in general depressed for both components in the block copolymers compared to the parent homopolymers. Polarized optical micrographs during isothermal crystalli zation of (a) homo-PLLA, (b) homo-PCL, (c) and (d) block copolymer after 30 min at 122 degrees C and after 15 min at 42 degrees C.

Self-organisation in the assembly of gels from mixtures of different dendritic peptide building blocks

This paper investigates dendritic peptides capable of assembling into nanostructured gels, and explores the effect on self-assembly of mixing different molecular building blocks. Thermal measurements, small angle Xray scattering (SAXS) and circular dichroism (CD) spectroscopy are used to probe these materials on macroscopic, nanoscopic and molecular length scales. The results from these investigations demonstrate that in this case, systems with different "size" and "chirality" factors can self-organise, whilst systems with different "shape" factors cannot. The "size" and "chirality" factors are directly connected with the molecular information programmed into the dendritic peptides, whilst the shape factor depends on the group linking these peptides together-this is consistent with molecular recognition hydrogen bond pathways between the peptidic building blocks controlling the ability of these systems to self-recognise. These results demonstrate that mixtures of relatively complex peptides, with only subtle differences on the molecular scale, can self-organise into nanoscale structures, an important step in the spontaneous assembly of ordered systems from complex mixtures.

Genistein blocks homocysteine-induced alterations in the proteome of human endothelial cells

Dietary isoflavones from soy are suggested to protect endothelial cells from damaging effects of endothelial stressors and thereby to prevent atherosclerosis. In search of the molecular targets of isoflavone action, we analyzed the effects of the major soy isoflavone, genistein, on changes in protein expression levels induced by the endothelial stressor homocysteine (Hcy) in EA.hy 926 endothelial cells. Proteins from cells exposed for 24 h to 25 mu M Hcy alone or in combination with 2.5 mu M genistein were separated by two-dimensional gel electrophoresis and those with altered spot intensities were identified by peptide mass fingerprinting, Genistein reversed Hcy-induced changes of proteins involved in metabolism, detoxification, and gene regulation: and some of those effects can be linked functionally to the antiatherosclerotic properties of the soy isoflavone. Alterations of steady-state levels of cytoskeletal proteins by genistein suggested an effect oil apoptosis. As a matter of fact genistein caused inhibition of Hcy-mediated apoptotic cell death as indicated by inhibition of DNA fragmentation and chromatin condensation. In conclusion, proteome analysis allows the rapid identification of cellular target proteins of genistein action in endothelial cells exposed to the endothelial stressor Hcy and therefore enables the identification of molecular pathways of its antiatherosclerotic action

The cannabinoid CB1 receptor antagonist SR141716 blocks the orexigenic effects of intrahypothalamic ghrelin

The paraventricular nucleus (PVN) of the hypothalamus plays a key role in the control of appetite and energy balance. Both ghrelin and cannabinoid receptor agonists increase food intake when administered into this nucleus: this study investigated possible interactions between the two systems in relation to eating. The orexigenic effect of ghrelin (100 pmol) when infused in to the PVN was reversed by a small, systemic dose of the CB1 cannabinoid receptor antagonist SR141716 (1 mg kg(-1)). This is the first demonstration of a functional relationship between brain ghrelin and endocannabinoid systems, and, although it needs to be further investigated, the effect of ghrelin on food intake when injected into the PVN seems to be mediated by stimulation of cannabinoid release.

Adobe Garamond Premier Pro Greek

In 2003, through a conference presentation in Vancouver and a series of exchanges with Lemon, Leonidas convinced Adobe to substantially extend the coverage of the Greek script in forthcoming Adobe typefaces. The revised brief for Garamond was extended to include, for the first time in a digital typeface, extensive polytonic support, full archaic characters, and small capitals with optional polytonic diacritics; these features should be implemented with respect for the Greek language’s complex rules for case conversion, allowing full dictionary support regardless of the features applied. This project was the first where these issues were addressed, both from a documentation and a development point of view. Leonidas’ responsibilities lay with researching historical and current conventions, developing specifications for the appearance and behaviour of the typefaces, editing glyph outlines, and testing of development versions.

Adobe Devanagari typeface

Typeface design: collaborative work commissioned by Adobe Inc. Published but unreleased. The Adobe Devanagari typefaces were commissioned from Tiro Typeworks and collaboratively designed by Tim Holloway, Fiona Ross and John Hudson, beginning in 2005. The types were officially released in 2009. The design brief was to produce a typeface for modern business communications in Hindi and other languages, to be legible both in print and on screen. Adobe Devanagari was designed to be highly readable in a range of situations including quite small sizes in spreadsheets and in continuous text setting, as well as at display sizes, where the full character of the typeface reveals itself. The construction of the letters is based on traditional penmanship but possesses less stroke contrast than many Devanagari types, in order to maintain strong, legible forms at smaller sizes. To achieve a dynamic, fluid style the design features a rounded treatment of distinguishing terminals and stroke reversals, open counters that also aid legibility at smaller sizes, and delicately flaring strokes. Together, these details reveal an original hand and provide a contemporary approach that is clean, clear and comfortable to read whether in short or long passages of text. This new approach to a traditional script is intended to counter the dominance of rigid, staccato-like effects of straight verticals and horizontals in earlier types and many existing fonts. OpenType Layout features in the fonts provide both automated and discretionary access to an extensive glyph set, enabling sophisticated typography. Many conjuncts preferred in classical literary texts and particularly in some North Indian languages are included; these literary conjuncts may be substituted by specially designed alternative linear forms and fitted half forms. The length of the ikars—ि and ी—varies automatically according to adjacent letter or conjunct width. Regional variants of characters and numerals (e.g. Marathi forms) are included as alternates. Careful attention has been given to the placements of all vowel signs and modifiers. The fonts include both proportional and tabular numerals in Indian and European styles. Extensive kerning covers several thousand possible combinations of half forms and full forms to anticipate arbitrary conjuncts in foreign loan words. _____

Construction of supramolecular helices and breaking the helicity by forming supramolecular β-sheet structures using suitable self-assembling pseudopeptide building blocks

Bis-valine derivatives or malonamide (Guha,S.; Drew, M.G.B. Small 2008, 4, 1993-2005) and a bis-valine derivative of 1,1-cyclopropone dicarboxamide were used as building blocks for the construction of supramolecular helical structures. The six-membered intramolecular hydrogen-bonded scaffold is formed, and this acts as a unique supramolecular synthon for the construction of a pseudopeptide-based supramolecular helical structure. However, in absence of this intramolecular hydrogen bond. intermolecular hydrogen bonds are formed among the peptide strands. This leads to a supramolecular beta-sheet structure. Proper selection of the supramolecular synthon (six-membered intramolecular hydrogenbonded scaffold) promotes supramolecular helix formation, and a deviation from this molecular structure dictates the disruption of supramolecular helicity. In this study, six crystal structures have been used to demonstrate that a change in the central angle and/or the central core structure of dicarboxamides can be used to design either a supramolecular helix or a beta-sheet.

Fibrils and nanotubes assembled from a modified amyloid-β peptide fragment differ in the packing of the same β-sheet building blocks

The peptide AAKLVFF assembles into fibrils in water and nanotubes in methanol. Solid-state NMR data are consistent with fibrils constructed from β-sheet bilayers and nanotubes bounded by a wall of offset β-sheet monolayers. Remarkably distinct morphologies are thus traced to subtle differences in the arrangement of the same fundamental building blocks.

Brill Greek, Adobe Arno Pro, Adobe Text/Brevier Greek typefaces

Typeface design: a series of collaborative projects commissioned by Adobe, Inc. and Brill to develop extensive polytonic Greek typefaces. The two Adobe typefaces can be seen as extension of previous research for the Garamond Premier Pro family (2005), and concludes a research theme started in 1998 with work for Adobe’s Minion Pro Greek. These typefaces together define the state of the art for text-intensive Greek typesetting for wide character set texts (from classical texts, to poetry, to essays, to prose). They serve both as exemplar for other developers, and as vehicles for developing the potential of Greek text typography, for example with the parallel inclusion of monotonic and polytonic characters, detailed localised punctuation options, fluid handling of case-conversion issues, and innovative options such as accented small caps (originally requested by bibliographers, and subsequently rolled out to a general user base). The Brill typeface (for the established academic publisher) has an exceptionally wide character set to cover several academic disciplines, and is intended to differentiate sufficiently from its partner Latin typeface, while maintaining a clear texture in both offset and low-resolution print-on-demand reproduction. This work involved substantial amounts of testing and modifying the design, especially of diacritics, to maintain clarity the readability of unfamiliar words. All together these typefaces form a study in how Greek typesetting meets contemporary typographic requirements, while resonating with historically accurate styles, where these are present. Significant research in printing archives helped to identify appropriate styles, as well as originate variants that are coherent stylistically, even when historical equivalents were absent.

Adobe Bickham Script Greek typeface

Design support for typeface design: collaborative work commissioned by Adobe, Inc. Published 2011. The original Bickham typeface was based on the hands of the 18th century writing master George Bickham. The ornate script represented the apogee of the art of formal writing with a steel nib, and defined the visual style for decorated, formal documents. In 2010 Adobe revised and extended the typeface, with the express purpose of making it a showcase for OpenType technology, demonstrating the visual importance of using different glyph forms in different contexts, employing contextual substitution rules. Although Bickham had published a single example of a Greek style, it was a standalone exercise, never intended to match the Latin. The key challenge was to identify historical records for appropriate Greek writing, preferably by writers familiar with the language, adapt them for digital typography and the particularities of contextual substitution, in a manner that would not make the Greek a ‘second-class citizen’. Research involved uncovering and analysing appropriate contemporary and later writing examples to identify both the range of writing styles of the period, and the manner of joining letters in written Greek with both pointed pens and broad nibs. This work was essential to make up for the comparative lack of relevant material by Bickham, as well as investigating the possible range of stylistic variants that were approved for the final typeface, which attempted to emulate a written texture through complex substitutions. This aspect of the work is highly original for implementing a substantial number of contextual alternates and ligatures. These were reviewed in the context of use, bringing together an analysis of occurring letter combinations and patterns, and the design of stylistic alternates to imitate natural handwriting.