Alluvial terrace development and changing landscape connectivity in the Great Karoo, South Africa. Insights from the Wilgerbosch Riyer catchment, Sneeuberg

Dendritic channel networks in the Wilgerbosch River catchment draining the south side of the Sneeuberg, South Africa, are deeply incised exposing terrace fills of varying thickness and extent. Channel long sections exhibit ‘stepped’ profiles where resistant rock strata cross valley floors but are now partially or completely breached. Using a combination of aerial image analysis, geomorphological mapping, sedimentological investigations (field logging, grain size, and magnetic susceptibility analyses), and geochronology (OSL, 14C), this study demonstrates the patterns and controls on erosion and sedimentation and, to a lesser extent, the age structure of fills in two low-order tributaries (Africanders Kloof and Wilgerbosch Kloof) and several reaches of the higher-order Wilgerbosch River. A conceptual model of terrace development in relation to changing conditions of connectivity is presented. Valley headwaters are dominated by discontinuous palaeochannel and floodout sediments; whilst in second- to fourth-order tributaries, four sedimentologically and stratigraphically distinct terrace fills that exceed the scale and complexity of deposits on the northward side of the Sneeuberg were identified and analysed. The early part of this regional terrace succession highlights the importance of interactions between periglacial and fluvial activity on cut, fill, and pedogenesis around the time of the deglacial period. Terrace development is shown to have been a complex response to reconnection of the channel network with upland colluvial stores resulting in the valleys becoming choked with sediment. This caused a rise in groundwater and formation of extensive calcretised rootmats on valley floors and slopes acting to ‘blanket’ terraces 1 and 2. The thickness and longevity of this blanket is shown to restrict depth of incision in subsequent phases (T3, T4). The deposits in these headwater valleys have, until now, been overlooked as a source of palaeoenvironmental information. This study is the first to demonstrate the role and importance of changing connectivity in 'cut and fill' phases that predate the late eighteenth century European incursion in the Sneeuberg

Bringing the outside world into the mathematics classroom - New approaches to the use of video in the classroom

Many countries are exploring different approaches to create a more relevant mathematics curriculum through the use of real world examples in the classroom. In this paper we will share some of the classroom video resources that have been developed since the last ICTMT: the series World of Maths (Teachers TV 2008) and i-Maths (British Broadcasting Corporation 2008). This also complements the UK’s “STEM” (Science, Technology, Engineering and Mathematics) agenda (Her Majesty's Treasury 2004) which aims to promote STEM subjects to the populus and increase student uptake in STEM related careers and courses

Phospho1 deficiency transiently modifies bone architecture yet produces consistent modification in osteocyte differentiation and vascular porosity with ageing

PHOSPHO1 is one of principal proteins involved in initiating bone matrix mineralisation. Recent studies have found that Phospho1 KO mice (Phospho1-R74X) display multiple skeletal abnormalities with spontaneous fractures, bowed long bones, osteomalacia and scoliosis. These analyses have however been limited to young mice and it remains unclear whether the role of PHOSPHO1 is conserved in the mature murine skeleton where bone turnover is limited. In this study, we have used ex-vivo computerised tomography to examine the effect of Phospho1 deletion on tibial bone architecture in mice at a range of ages (5, 7, 16 and 34 weeks of age) to establish whether its role is conserved during skeletal growth and maturation. Matrix mineralisation has also been reported to influence terminal osteoblast differentiation into osteocytes and we have also explored whether hypomineralised bones in Phospho1 KO mice exhibit modified osteocyte lacunar and vascular porosity. Our data reveal that Phospho1 deficiency generates age-related defects in trabecular architecture and compromised cortical microarchitecture with greater porosity accompanied by marked alterations in osteocyte shape, significant increases in osteocytic lacuna and vessel number. Our in vitro studies examining the behaviour of osteoblast derived from Phospho1 KO and wild-type mice reveal reduced levels of matrix mineralisation and modified osteocytogenic programming in cells deficient in PHOSPHO1. Together our data suggest that deficiency in PHOSPHO1 exerts modifications in bone architecture that are transient and depend upon age, yet produces consistent modification in lacunar and vascular porosity. It is possible that the inhibitory role of PHOSPHO1 on osteocyte differentiation leads to these age-related changes in bone architecture. It is also intriguing to note that this apparent acceleration in osteocyte differentiation evident in the hypomineralised bones of Phospho1 KO mice suggests an uncoupling of the interplay between osteocytogenesis and biomineralisation. Further studies are required to dissect the molecular processes underlying the regulatory influences exerted by PHOSPHO1 on the skeleton with ageing

Tris-N-alkylpyridinium-functionalised cyclotriguaiacylene hosts as axles in branched [4]pseudorotaxane formation

A series of [4]pseudorotaxanes composed of three-way axle threads based on the cyclotriguaiacylene family of crown-shaped cavitands and three threaded macrocyclic components has been achieved. These exploit the strong affinity for electron-poor alkyl-pyridinium units to reside within the electron-rich cavity of macrocycles, in this case dimethoxypillar[5]arene (DMP). The branched [4]pseudorotaxane= assemblies {(DMP)3∙L}3+,where L = N-alkylated derivatives of the host molecule (±)-tris-(isonicotinoyl)cyclotriguaiacylene, were characterised by NMR spectroscopy and mass spectrometry, and an energy-minimised structure of {(DMP)3∙(tris-(N-propyl-isonicotinoyl)cyclotriguaiacylene)}3+ was calculated. Crystal structures of N-ethyl-isonicotinoyl)cyclotriguaiacylene hexafluorophosphate and N-propyl-isonicotinoyl)cyclotriguaiacylene hexafluorophosphate each show ‘hand-shake’ self-inclusion motifs occurring between the individual cavitands

Homochiral self-sorted and emissive IrIII metallo-cryptophanes

We thank the EPSRC (DTG award 1238852, EP/K039202/1, EP/M02105X/1, EP/J001325/1), Leverhulme Trust (RPG-2014-148), University of St Andrews, and the MEXT/JSPS Grants in Aid for Scientific Research (JP25102005 and JP25102001) for funding; Simon Barrett for assistance with NMR; Martin Huscroft for assistance with HPLC, and Stephen Boyer for elemental analysis measurements.The racemic ligands (±)-tris(isonicotinoyl)-cyclotriguaiacylene (L1), or (±)-tris(4-pyridyl-methyl)-cyclotriguaiacylene (L2) assemblewith racemic (Λ, Δ)- [Ir(ppy)2(MeCN)2]+, in which ppy = 2-phenylpyridinato to form [{Ir(ppy)2}3(L)2]3+ metallo-cryptophane cages. The crystal structure of [{Ir(ppy)2}3(L1)2]∙3BF4 has MM-ΛΛΛ nd PP-ΔΔΔ isomers, and homochiral self-sorting occurs in solution, a processaccelerated by a chiral guest. Self-recognition between L1 and L2 within cagesdoes not occur, and cages show very slow ligand-exchange. Both cages are phosphorescent,with [{Ir(ppy)2}3(L2)2]3+ havingenhanced and blue-shifted emission when compared with [{Ir(ppy)2}3(L1)2]3+ .PostprintPeer reviewe

You’ll never walk alone: supportive social relations in a football and mental health project

Football can bring people together in acts of solidarity and togetherness. This spirit is most evocatively illustrated in the world renowned football anthem You’ll Never Walk Alone (YNWA). In this paper we argue that this spirit can be effectively harnessed in nursing and mental health care. We draw on data from qualitative interviews undertaken as part of evaluating a football and mental health project to explore the nature of supportive social relations therein. We use some of the lyrics from YNWA as metaphor to frame our thematic analysis. We are especially interested in the interactions between the group facilitators and group members, but also address aspects of peer support within the groups. A contrast is drawn between the flexible interpersonal boundaries and self-disclosure evident in the football initiative and the reported more distant relations with practitioners in mainstream mental health services. Findings suggest scope for utilising more collective, solidarity enhancing initiatives and attention to alliances and boundaries to maximise engagement and therapeutic benefits within routine practice

Follistatin-like 3 (FSTL3) mediated silencing of transforming growth factor (TGF ) signaling is essential for testicular aging and regulating testis size

Follistatin-like 3 (FSTL3) is a glycoprotein that binds and inhibits the action of TGFβ ligands such as activin. The roles played by FSTL3 and activin signaling in organ development and homeostasis are not fully understood. The authors show mice deficient in FSTL3 develop markedly enlarged testes that are also delayed in their age-related regression. These FSTL3 knockout mice exhibit increased Sertoli cell numbers, allowing for increased spermatogenesis but otherwise showing normal testicular function. The data show that FSTL3 deletion leads to increased AKT signaling and SIRT1 expression in the testis. This demonstrates a cross-talk between TGFβ ligand and AKT signaling and leads to a potential mechanism for increased cellular survival and antiaging. The findings identify crucial roles for FSTL3 in limiting testis organ size and promoting age-related testicular regression