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Middle Pleistocene fluvial deposits of the Corbets Tey Formation at Purfleet, Essex, provide evidence of an un-named and previously poorly recognized interglacial, thought to corrrelate with Oxygen Isotope Stage (OIS) 9. Previous attributions of the sediments to the Ipswichian (Last Interglacial) Stage are refuted. New investigations have yielded rich molluscan, mammalian and ostracod assemblages that indicate fully temperate conditions and the distal influence of marine transgression. Pollen analyses suggest a previously unrecorded phase of interglacial vegetational development. Clast composition, geomorphological evidence and the occurrence of molluscs that favour large rivers all point to deposition by the Thames, rather than in a minor tributary, as suggested previously. Three separate Palaeolithic industries in stratigraphical superposition are recognized at Purfleet, these being Clactonian, Acheulean and Levallois. Purfleet is therefore a key locality in the understanding of the early human occupation and exploitation of southern Britain, as well as for the interpretation and correlation of the terrace sequence in the Thames Valley.

Although known from the nineteenth century, the terraces of the Medway have been far less frequently described in the literature than those of the Thames. In particular, the well known fossiliferous occurrences of such sites as Swanscombe, Purfleet and Aveley have no counterpart in the Medway, despite the two rivers forming part of the same basin. Here we describe molluscan and ostracod faunas of Middle Pleistocene age from Allhallows, Kent close to the modern confluence of the two rivers, which begin to allow correlation of the Medway terraces with the better known Thames succession.

The Hedgehog (Hh) receptor Patched-1 (PTCH1) opposes the activation of Gli transcription factors and induces cell death through a Gli-independent pathway. Here, we report that the C-terminal domain (CTD) of PTCH1 interacts with and is ubiquitylated on K1413 by the E3 ubiquitin-protein ligase Itchy homolog (Itch), a Nedd4 family member. Itch induces the ubiquitylation of K1413, the reduction of PTCH1 levels at the plasma membrane, and degradation, activating Gli transcriptional activity in the absence of Hh ligands. Silencing of Itch stabilizes PTCH1 and increases its level of retention at the plasma membrane. Itch is the preferential PTCH1 E3 ligase in the absence of Hh ligands, since of the other seven Nedd4 family members, only WW domain-containing protein 2 (WWP2) showed a minor redundant role. Like Itch depletion, mutation of the ubiquitylation site (K1314R) resulted in the accumulation of PTCH1 at the plasma membrane, prolongation of its half-life, and increased cell death by hyperactivation of caspase-9. Remarkably, Itch is the main determinant of PTCH1 stability under resting conditions but not in response to Sonic Hedgehog. In conclusion, our findings reveal that Itch is a key regulator of ligand-independent Gli activation and noncanonical Hh signaling by the governance of basal PTCH1 internalization and degradation.

River-channel and colluvial deposits, near Marsworth, Buckinghamshire, record a temperate-periglacial-temperate sequence during the late Middle Pleistocene. The deposits of a lower channel contain tufa clasts bearing leaf impressions that include Acer sp., and Sorbus aucuparia and containing temperate arboreal pollen attributed to ash-dominated woodland. The tufa probably formed at the mouth of a limestone spring before being redeposited in a small river whose deposits contain plant remains, Mollusca, Coleoptera, Ostracoda and vertebrate bones of temperate affinities. The sediments, sedimentary structures and limited biological remains above the Lower Channel deposits indicate that fluvial deposition preceded climatic cooling into periglacial conditions. Fluvial deposition recurred during a later temperate episode, as shown by the mammalian bone assemblage in stratigraphically higher channel deposits. The Upper Channel deposits are confidently attributed to Oxygen Isotope Sub-Stage 5e (Ipswichian) on the basis of their vertebrate remains. However, the age of the Lower Channel deposits is less clear. The mammalian and coleopteran remains in the Lower Channel strongly suggest correlation with Oxygen Isotope Stage 7 on the basis of their similarities to other sites whose stratigraphy is better known and the clear difference of the Lower Channel assemblage from well-established faunas of Ipswichian or any other age. By contrast, U–Th dating of the tufa clasts suggests an age post 160 ka BP, while Aile/Ile ratios on Mollusca point to an Ipswichian age and younger. Four ways of interpreting this age discrepancy are considered, the preferred one correlating the Lower Channel deposits with Oxygen Isotope Stage 7.

The fossils of non-marine Mollusca are among the most prominent in Pleistocene deposits. They were one of the first fossil groups to be noted in the literature, as early as the beginning of the 18th century. With the stabilisation of taxonomies in the 19th century numerous publications appeared with faunal lists of interglacial taxa, but few attempts were made to use the data for interpretation. Work from 1950 onwards, especially by Sparks and Kerney in Britain, Puissegur in France, and by Ložek in Central Europe, used a quantitative approach to sorting, counting and interpreting assemblages. Despite the adoption of this rigorous methodology to molluscan studies, interglacial faunas were used primarily to reconstruct past environments, and although faunal changes through the Pleistocene were recognised, it was thought that non-marine Mollusca were inherently badly fitted for use as tools for dating in the classic geological sense. Recent work, coupled with the re-evaluation of sites described in the literature, has allowed non-marine molluscan faunas to be used as biostratigraphic indicators. Biostratigraphic schemes evolved from this work are comparable with parallel investigations using Mammalia, Coleoptera and lithostratigraphy calibrated by a number of geochronometric methods, but may be at variance with pollen biostratigraphies.

Phosphoinositides play key regulatory roles in vesicular transport pathways in eukaryotic cells. Clathrin-mediated membrane trafficking has been shown to require phosphoinositides, but little is known about the enzyme(s) responsible for their formation. Here we report that clathrin functions as an adaptor for the class II PI 3-kinase C2alpha (PI3K-C2alpha), binding to its N-terminal region and stimulating its catalytic activity, especially toward phosphorylated inositide substrates. Further, we show that endogenous PI3K-C2alpha is localized in coated pits and that exogenous expression affects clathrin-mediated endocytosis and sorting in the trans-Golgi network. These findings provide a mechanistic basis for localized inositide generation at sites of clathrin-coated bud formation, which, with recruitment of inositide binding proteins and subsequent synaptojanin-mediated phosphoinositide hydrolysis, may regulate coated vesicle formation and uncoating.

Huntingtin-interacting protein 1 related (Hip1R) is a novel component of clathrin-coated pits and vesicles and is a mammalian homologue of Sla2p, an actin-binding protein important for both actin organization and endocytosis in yeast. Here, we demonstrate that Hip1R binds via its putative central coiled-coil domain to clathrin, and provide evidence that Hip1R and clathrin are associated in vivo at sites of endocytosis. First, real-time analysis of Hip1R–YFP and DsRed–clathrin light chain (LC) in live cells revealed that these proteins show almost identical temporal and spatial regulation at the cell cortex. Second, at the ultrastructure level, immunogold labeling of ‘unroofed’ cells showed that Hip1R localizes to clathrin-coated pits. Third, overexpression of Hip1R affected the subcellular distribution of clathrin LC. Consistent with a functional role for Hip1R in endocytosis, we also demonstrated that it promotes clathrin cage assembly in vitro. Finally, we showed that Hip1R is a rod-shaped apparent dimer with globular heads at either end, and that it can assemble clathrin-coated vesicles and F-actin into higher order structures. In total, Hip1R's properties suggest an early endocytic function at the interface between clathrin, F-actin, and lipids.

SUMMARY Radiocarbon-dated Late Devensian and early Holocene pollen, molluscan and ostracod assemblages, from the sediments of an infilled kettle-hole lake near Wooler in north-eastern Northumberland, are described and discussed in both a local and a wider context. During the Lateglacial interstadial, open birch woodland developed for a short time after herbaceous vegetation had first dominated the surrounding landscape. Scrub was present for the remainder of the interstadial. Mollusca and Ostracoda immigrated into the lake during the pre-woodland phase of the interstadial, then disappeared, perhaps due to a climatic deterioration. A depauperate fauna returned in the latter part of the interstadial, when a less hostile aquatic environment may have existed. In the succeeding Loch Lomond Stadial, a periglacial climate led to tundra-like vegetation and to the extirpation once again of the lacustrine fauna. In the early Holocene, Betula- then Corylus -dominated woodland was preceded by scrub and heath. Mollusca and Ostracoda recolonized the water body at the start of the Holocene, with the former quickly developing a diverse fauna. Two episodes of increased lake level with an intervening fall are suggested by the faunal assemblages. The second rise in water level was accompanied by vegetation changes in its environs, which may have been linked to a wetter and cooler climate than that which preceded it, and which occurred between 8000 and 7000 BP.

SUMMARY A sequence of peat and calcareous organic mud from the floodplain of the River Ure near Ripon has yielded pollen, plant macrofossils, Mollusca, Coleoptera, and Ostracoda which allow the first recorded reconstruction of earliest Holocene valley-floor environments for this area. A conventional radiocarbon date on a bulk sample of peat yielded an age of 9710 ± 60 bp. The palaeontological evidence suggests that the sediments accumulated in a shallow, slow moving or stagnant water body, surrounded by marshy, damp, grassland, away from contemporary channel processes, probably of a single thread river system. The climate during deposition of the sediments was no warmer than the present, and possibly slightly colder.

This paper describes Pleistocene fluvial deposits of the River Great Ouse at Woolpack Farm, Fenstanton, Cambridgeshire, UK. These sediments consist of a basal gravel, fossiliferous fluviatile muds, sands and gravels later disturbed and formed into a diamicton, and overlying gravels. The regional climate inferred from palaeobotany, Mollusca, Coleoptera and vertebrates from the diamicton indicates temperate conditions. Coleopteran evidence suggests a mean July temperature of ca . 21°C, 4°C warmer than today in eastern England, and winter temperatures a little colder than at present. Molluscan assemblages indicate a slight brackish influence during deposition of the muds which form the diamicton. The gravel succession is represented by three members which have a broad distribution in the Great Ouse Valley, and which were laid down in a braided river under periglacial conditions. The occurrence of permafrost is indicated by the presence of ice wedge casts in the gravels. The pollen and macrofossil evidence from the diamicton suggests correlation with Ipswichian substage IpII ( Pinus – Quercetum mixtum – Corylus phase). The basal gravel is of pre-Ipswichian age. A Devensian age is proposed for the overlying gravels and their attendant periglacial phenomena.

A detailed multidisciplinary investigation of intertidal freshwater sediments exposed in the north of the Bay of Skaill, Mainland Orkney, Scotland, have revealed a complex sedimentary sequence. This provided evidence for dynamic coastal environmental changes in the area since the mid-Holocene. Freshwater ponds developed on glacial sediments ca. 6550 ± 80 yr BP (cal. bc 5590–5305). From ca. 6120 ± 70 yr BP (cal. bc 5040–4855), these were infilled by blown sand from the distal edge of a dune ridge located to the west. Thereafter, a series of sand-blow events alternating with periods of quiescence occurred until ca. 4410 ± 60 yr BP (cal. bc 3325–2900). Between ca. 5240 ± 160 and 4660 ± 80 yr BP (cal. bc 4370–3115), pollen and charcoal records show evidence of anthropogenic activities, associated with the nearby Neolithic settlement of Skara Brae. Agriculture was probably affected by recurrent sand movement and widespread deposition of calcium carbonate in the hinterland of the bay. Machair development between ca. 6100 and 5000 yr BP (cal. bc 5235–3540) corresponds to a mid-Holocene phase of dune formation recorded elsewhere in northwest Europe. The more recent and progressive formation of the bay has probably been related to increasing external forcing via storminess, long-term relative sea-level change and sediment starvation within this exposed environment. Copyright © 2000 John Wiley & Sons, Ltd.

Palaeo-shore positions help to evidence long-term eustatic changes and assist in the understanding of tectonic movements at a regional scale. Raised beaches anomalies exist in the Channel region and may result from deformations induced by neotectonic or by glacio-isostasy. The aim of this paper is to re-analyse, within their geodynamic context in the Channel and Dover Strait regions, the stratigraphy and the datings of palaeo-shores of Middle and Upper Pleistocene ages. This sector of Europe is characterised by strong geological contrasts and is controlled by two main geological boundaries: in the north, the Variscan Overthrust (corresponding approximately to the position of the Dover Strait) and, in the south, the Northern Branch of the Southern Brittany shearing zone. These two boundaries border a domain which seems to behave rather homogeneously on a large scale under the control of plate tectonics. Today, shorelines are subsiding north and south of this ‘Channel’ region. Episodic uplift largely controlled the open or closed status of the Dover Strait, especially after the Messinian and Early Quaternary, by reactivating Variscan structures. After 400 ka, global cooling allowed supplementary deformations in the area to be induced by glacio-isostatic rebound and clustered seismic activity during the phase of ice sheet building. Evidence of eight different transgressions dated by ESR from Oxygen Isotopic Stage (OIS) 13 to the end of OIS 5 shows the complexity of the sea-level records in a region unstable for isostatic and neotectonic reasons. Due to glacio-isostatic depression, transgressions are possible in late glacial times as well as during full interglacials. Most platforms were initially cut, during the Late Miocene, and seem to have been re-trimmed several times, especially by shore ice rafting since OIS 9. Regionally, the sea apparently rose to about the same level in O.I. Stages 11, 9 and 7. Glacio-isostatic and glacio-eustatic relative displacements of the sea level together with background tectonic movements have modified coastal positions and have temporarily altered the intensity of tidal currents. The oldest shoreline deposits are preserved only in subsiding areas, controlled by the deep crustal pattern. Neotectonics related to Variscan structure reactivation still dominates glacio-isostatic deformation and basin subsidence. The OIS 7 positive anomaly seems related to a regional relaxation event.

Pollen, plant macrofossil, molluscan and coleopteran data from organic muds below the low terrace of the River Welland at Deeping St James, Lincolnshire indicate deposition in the mixed oak forest phase of a Late Pleistocene interglacial. Coleopteran and molluscan data suggest summer temperatures up to 4°C warmer than at present in eastern England, and plant macrofossil material suggests a climate more continental than that of Britain in the Holocene. No direct analogue of this biota, however, exists currently in Europe. Biostratigraphical indications from the pollen coleoptera and Mollusca suggest an age in the Ipswichian Interglacial. Thermoluminescence dates between 120 ka and 75 ka and amino-acid ratios with a mean of 0.11 show that deposition of the sediments took place during Oxygen Isotope Stage 5. This accurate dating of a partial Ipswichian succession allows discussion of the ages of a number of other interglacial sites in eastern England of assumed Ipswichian age. Copyright © 1999 John Wiley & Sons, Ltd.

This paper re-examines the age of the Fulbeck Sand and Gravel and the chronology of the Trent Terraces following amino acid dating of a molluscan fauna found within a basin at Bassingham Fen, incised c . 3 m below the Fulbeck deposit. Two species were dated and yielded different ratios, Lymnaea peregra 0.074 ± 0.002 (2), and Valvata piscinalis 0.131 ± 0.002 (2). It is argued that the V. piscinalis are derived and that the L. peregra indicate the true age of the deposit. Currently available amino acid geochronologies suggest that the shells of L. peregra were deposited between sub-stage 5a and 4 of the early Devensian ( c. 85–64 ka BP ). Correlation with sub-stage 5a would suggest correlation with the Odderade Interstadial of continental Europe and with the only other known 5a site in England, at Cassington in the Upper Thames. Incision into the temperate sub-stage 5e deposits may perhaps have been associated with adjustment of base levels to the cold climate conditions of the early Devensian and suggests unimpeded drainage through the area to the North Sea. More problematic, is the interpretation of the V. piscinalis ratios; with assignment to either warm sub-stage 5e ( c. 125–115 ka BP ) or cold sub-stage 5d ( c . 115–105 ka BP ) using a younger amino acid geochronology, or using an older geochronology, to cold stage 6 ( c . 128–195 ka BP ). The implications of the V. piscinalis ratios for the chronology of the Trent terraces is discussed.

The clathrin-associated AP-2 adaptor protein is a major polyphosphoinositide-binding protein in mammalian cells. A high affinity binding site has previously been localized to the NH2-terminal region of the AP-2 α subunit (Gaidarov et al. 1996. J. Biol. Chem. 271:20922–20929). Here we used deletion and site- directed mutagenesis to determine that α residues 21–80 comprise a discrete folding and inositide-binding domain. Further, positively charged residues located within this region are involved in binding, with a lysine triad at positions 55–57 particularly critical. Mutant peptides and protein in which these residues were changed to glutamine retained wild-type structural and functional characteristics by several criteria including circular dichroism spectra, resistance to limited proteolysis, and clathrin binding activity. When expressed in intact cells, mutated α subunit showed defective localization to clathrin-coated pits; at high expression levels, the appearance of endogenous AP-2 in coated pits was also blocked consistent with a dominant-negative phenotype. These results, together with recent work indicating that phosphoinositides are also critical to ligand-dependent recruitment of arrestin-receptor complexes to coated pits (Gaidarov et al. 1999. EMBO (Eur. Mol. Biol. Organ.) J. 18:871–881), suggest that phosphoinositides play a critical and general role in adaptor incorporation into plasma membrane clathrin-coated pits.

For much of the Middle and all of the Upper Pleistocene the Upper Thames valley has remained outside the limit of ice advance. The main agents of landform evolution have been the River Thames and its tributaries, which have cut down episodically and in so doing have abandoned a series of river terraces. This study reports the findings of an investigation into exposures in the deposits underlying the Floodplain Terrace at Cassington, near Oxford, England. The sequence exposed reveals a stratigraphy of basal, predominantly fine-grained, lithofacies overlain by coarser gravel lithofacies. The fluvial architecture of these deposits indicates a major change in fluvial style from a low-energy (meandering) to a high energy (braided) channel system. The flora and fauna from the lower fine-grained lithofacies display a marked change from temperate at the base, to colder conditions towards the top, indicating a close association between deteriorating climate and changing fluvial depositional style. Amino acid and luminescence geochronology from the basal fine-grained lithofacies suggest correlation with Oxygen isotope Stage 5 and hence it is argued that the major environmental change recorded at the site relates to the Oxygen-Isotope Stage 5-4 transition. Deposition of much of the overlying gravel sequence probably occurred during Oxygen isotope Stage 4, suggesting that the latter half of the Devensian may be less significant, in terms of fluvial landscape evolution in the Upper Thames valley, than was believed previously. (C) 1998 John Wiley & Sons, Ltd.

Fluvial gravels exposed beneath the surface of the low terrace of the River Ivel have been investigated in a quarry south of Sandy, Bedfordshire. Sedimentological investigations suggest that deposition occurred as bars and sheets in a braided river regime. Fossiliferous silt lenses occur within the gravel and their contents indicate deposition under slow moving or still water conditions in abandoned small channels. The palaeontological data from plant macrofossil remains, Mollusca and Coleoptera present a consistent picture of a harsh climate similar to that of the tundra areas of arctic Russia at the present day. Mutual Climatic Range (MCR) estimates based on Coleoptera indicate a mean temperature of the warmest month between +8°C and +11°C, and a mean temperature of the coldest month between -10°C and -28°C. Radiocarbon ages of 34 055+330-310 (Q-2936) and 29 250+460-420 (Q-2935) yrs BP suggest dates for the lower part of the gravelly sequence, in the Middle Devensian, at the end of the Upton Warren Interstadial Complex.

The albumin excretion rate following an oral glucose load was measured, using a sensitive radio-immunoassay method, in three groups drawn from the population of Bedford. The three groups – normal,borderline diabetic and diabetic – were classified by the level of the blood sugar 2 hours after the 50 -g glucose load. The degree of albumin excretion was positively correlated with the 2-hour blood sugar level, suggesting that hyperglycaemia may cause renal functional abnormality, which may be present at or before the time of diagnosis. In the diabetic group, only, the degree of albumin excretion was also positively correlated with the height of the blood pressure.

We recently demonstrated that nonvisual arrestins interact via a C-terminal binding domain with clathrin and function as adaptor proteins to promote β2-adrenergic receptor (β2AR) internalization. Here, we investigated the potential utility of a mini-gene expressing the clathrin-binding domain of β-arrestin (β-arrestin (319–418)) to function as a dominant-negative with respect to β2AR internalization and compared its properties with those of β-arrestin and β-arrestin-V53D, a previously reported dominant-negative mutant.In vitro studies demonstrated that β-arrestin-V53D bound better to clathrin than β-arrestin but was significantly impaired in its interaction with phosphorylated G protein-coupled receptors. In contrast, whereas β-arrestin (319–418) also bound well to clathrin it completely lacked receptor binding activity. When coexpressed with the β2AR in HEK293 cells, β-arrestin (319–418) effectively inhibited agonist-promoted receptor internalization, whereas β-arrestin-V53D was only modestly effective. However, both constructs significantly inhibited the stimulation of β2AR internalization by β-arrestin in COS-1 cells. Interestingly, immunofluorescence microscopy analysis reveals that both β-arrestin (319–418) and β-arrestin-V53D are constitutively localized in clathrin-coated pits in COS-1 cells. These results indicate the potential usefulness of β-arrestin (319–418) to effectively block arrestin-clathrin interaction in cells and suggest that this construct may prove useful in further defining the mechanisms involved in G protein-coupled receptor trafficking.

Preface 145Introduction 156Morley vs. Montagu 169

We have recently demonstrated that the nonvisual arrestins, β-arrestin and arrestin3, interact with high affinity and stoichiometrically with clathrin, and we postulated that this interaction mediates internalization of G protein-coupled receptors (Goodman, O. B., Jr., Krupnick, J. G., Santini, F., Gurevich, V. V., Penn, R. B., Gagnon, A. W., Keen, J. H., and Benovic, J. L. (1996)Nature 383, 447–450). In this study, we localized the clathrin binding domain of arrestin3 using a variety of approaches. Truncation mutagenesis demonstrated that the COOH-terminal half of arrestin3 is required for clathrin interaction. Assessment of the clathrin binding properties of various glutathione S-transferase-arrestin3 fusion proteins indicated that the predominant clathrin binding domain is contained within residues 367–385. Alanine scanning mutagenesis further localized this domain to residues 371–379, and site-directed mutagenesis demonstrated the critical importance of both hydrophobic (Leu-373, Ile-374, and Phe-376) and acidic (Glu-375 and Glu-377) residues in the arrestin3/clathrin interaction. These results are complementary to the observation that hydrophobic and basic residues in clathrin are critical for its interaction with nonvisual arrestins (Goodman, O. B., Jr., Krupnick, J. G., Gurevich, V. V., Benovic, J. L., and Keen, J. H. (1997)J. Biol. Chem. 272, 15017–15022). Lastly, an arrestin3 mutant in which Leu-373, Ile-374, and Phe-376 were mutated to Ala was significantly defective in its ability to promote β2-adrenergic receptor internalization in COS-1 cells when compared with wild-type arrestin3. Taken together, these results implicate a discrete region of arrestin3 in high affinity binding to clathrin, an interaction critical for agonist-promoted internalization of the β2-adrenergic receptor.

Previously we demonstrated that nonvisual arrestins exhibit a high affinity interaction with clathrin, consistent with an adaptor function in the internalization of G protein-coupled receptors (Goodman, O. B., Jr., Krupnick, J. G., Santini, F., Gurevich, V. V., Penn, R. B., Gagnon, A. W., Keen, J. H., and Benovic, J. L. (1996) Nature 383, 447–450). In this report we show that a short sequence of highly conserved residues within the globular clathrin terminal domain is responsible for arrestin binding. Limited proteolysis of clathrin cages results in the release of terminal domains and concomitant abrogation of arrestin binding. The nonvisual arrestins, β-arrestin and arrestin3, but not visual arrestin, bind specifically to a glutathioneS-transferase-clathrin terminal domain fusion protein. Deletion analysis and alanine scanning mutagenesis localize the binding site to residues 89–100 of the clathrin heavy chain and indicate that residues 1–100 can function as an independent arrestin binding domain. Site-directed mutagenesis identifies an invariant glutamine (Glu-89) and two highly conserved lysines (Lys-96 and Lys-98) as residues critical for arrestin binding, complementing hydrophobic and acidic residues in arrestin3 which have been implicated in clathrin binding (Krupnick, J. G., Goodman, O. B., Jr., Keen, J. H., and Benovic, J. L. (1997) J. Biol. Chem. 272, 15011–15016). Despite exhibiting high affinity clathrin binding, arrestins do not induce coat assembly. The terminal domain is oriented toward the plasma membrane in coated pits, and its binding of both arrestins and AP-2 suggests that this domain is the anchor responsible for adaptor-receptor recruitment to the coated pit.

Organic sediment from Frog Hall Pit, near Coventry, has produced pollen, plant macrofossil, insect, ostracod and molluscan data indicative of the early part of a temperate episode in the Middle Pleistocene. The regional stratigraphy and clast lithological characteristics of the gravels underlying the temperate deposits show that the whole sequence at the site post-dates the major glaciation (the Wolstonian sensu Mitchell et al., 1973) of the Midlands. Amino-acid D/L ratios from molluscan shells give mean values of 0.24, which is consistent with an age in Oxygen Isotope Stage 9 and comparable with those from the Hoxnian Interglacial of East Anglia. This age-estimate for the Frog Hall organic deposit places a minimum age on the Wolstonian Glaciation of the Midlands in Oxygen Isotope Stage 10, and therefore close in time to the Anglian (Oxygen Isotope Stage 12) Cold Stage. © 1997 John Wiley & Sons, Ltd.

New data from the complex Lower Thames locality at Purfleet, Essex, reinforce the correlation of interglacial deposits there with Marine Isotope Stage (MIS) 9, the second of four post-Anglian (MIS 12) interglacials recorded in the river-terrace sequence east of London. Arising from various developer-funded archaeologically driven projects, and primarily the construction of ‘High Speed 1’ (HS1: formerly the Channel Tunnel Rail Link), the new evidence includes additions to palaeontological knowledge of this interglacial, notably from ostracods and vertebrates, results from isotopic analyses of shell and concretionary carbonates, and the first application of numerical dating techniques at Purfleet. These analyses, combined with palaeotemperature estimates from the Mutual Ostracod Temperate Range method, confirm that deposition of the fossiliferous deposits coincided with interglacial conditions, with similar-to- or warmer-than-present summer temperatures and colder winters, providing a suggestion of greater continentality. OSL and amino-acid racemisation support correlation of the interglacial with MIS 9, whereas the climatic and sedimentological evidence points to correlation with the earliest and warmest substage (MIS 9e). There is also evidence that a greater part of the Purfleet sequence might date from the interglacial, although whether these also represent MIS 9e or later parts of the complex stage cannot be determined. The additional archaeological material is consistent with previous interpretations of a tripartite stratigraphical sequence of lithic traditions: basal Clactonian, above which is Acheulian (handaxe manufacture), followed by one of the earliest British appearances of Levallois technique. However, given the revised interpretation of the climatic affinity of the upper parts of the sequence, Levallois technique might have been used at Purfleet before the end of MIS 9.

The ability of a system to regulate its responsiveness in the presence of a continuous stimulus, often termed desensitization, has been extensively characterized for the beta2-adrenergic receptor (beta2AR). beta2AR signalling is rapidly attenuated through receptor phosphorylation and subsequent binding of the protein beta-arrestin. Ultimately the receptor undergoes internalization, and although the molecular mechanism is unclear, receptor phosphorylation and beta-arrestin binding have been implicated in this processs. Here we report that beta-arrestin and arrestin-3, but not visual arrestin, promote beta2AR internalization and bind with high affinity directly and stoichiometrically to clathrin, the major structural protein of coated pits. Moreover, beta-arrestin/arrestin chimaeras that are defective in either beta2AR or clathrin binding show a reduced ability to promote beta2AR endocytosis. Immunofluorescence microscopy of intact cells indicates an agonist-dependent colocalization of the beta2AR and beta-arrestin with clathrin. These results show that beta-arrestin functions as an adaptor in the receptor-mediated endocytosis pathway, and suggest a general mechanism for regulating the trafficking of G-protein-coupled receptors.

The fundamental mechanisms by which receptors once targeted for endocytosis are found in coated pits is an important yet unresolved question. Specifically, are activated receptors simply trapped on encountering preexisting coated pits, subsequently being rapidly internalized? Or do the receptors themselves, by active recruitment, gather soluble coat and cytosolic components and initiate the rapid assembly of new coated pits that then mediate their internalization? To explore this question, we studied the relationship between activation of IgE-bound high affinity Fc receptors (FCepsilonRI) and coated pit formation. Because these receptors are rapidly internalized via clathrin-coated pits only when cross-linked by the binding of multivalent antigens, we were able to separate activation from internalization by using an immobilized antigen. The FCepsilonRIs, initially uniformly distributed over the cell surface. relocalized and aggregated on the antigen-exposed membrane. The process was specific for the antigen, and temperature- and time-dependent. This stimulation initiated a cascade of cellular responses typical of FCepsilonRI signaling including membrane ruffling, cytoskeletal rearrangements, and, in the presence of Ca2+, exocytosis. Despite these responses, no change in coated pit disposition or in the distribution of clathrin and assembly protein AP2 was detected, as monitored by immunoblotting and by quantitative (vertical sectioning) confocal microscopy analysis of immunofluorescently stained cells. Specifically, there was no decrease in the density of clathrin-coated pits in regions of the cell membrane not in contact with the antigen, and there was no apparent increase in clathrin-coated pits in proximity to stimulated FCepsilonRI receptors as would have been expected if the receptors were inducing formation of new pits by active recruitment. These results indicate that de novo formation of clathrin-coated pits is not a prerequisite for rapid internalization or a direct response to stimulation of FCepsilonRI receptors. Therefore, increases in coated pits reported to occur in response to activation of some signaling receptors must be consequences of the signal transduction processes, rather than strictly serving the purpose of the internalization of the receptors.

We have investigated thrombin-stimulated morphological changes and the activation of phosphoinositide 3-kinase (PI 3-K), as manifested by the accumulation of PtdIns(3,4)P2 and PtdIns(3,4,5)P3 (labelled with 32P or myo-[3H]inositol), in CHRF-288 cells, a leukaemic cell line derived from a platelet progenitor cell. We report that these cells, when exposed to thrombin or SFLLRN (the peptide Ser-Phe-Leu-Leu-Arg-Asn, a thrombin-receptor ligand) rapidly change shape, forming membrane 'blebs', detectable by differential interference contrast or confocal microscopy, as well as labelled 3-phosphorylated phosphoinositides. The 'blebs' are distinguishable from 'ruffles' or lamellae, since they do not contain phalloidin-detectable actin. Studies with permeabilized cells indicate that PI 3-K is activated synergistically by thrombin+guanosine 5'[gamma-thio]triphosphate. Two forms of PI 3-K, i.e. PI 3-K(gamma) and p85/PI 3-K, regulated by G beta gamma subunits of heterotrimeric G-protein and the small G-protein Rho, respectively, are present in these cells, as is true for platelets. Wortmannin, a known potent and specific inhibitor of PI 3-K activities, inhibits thrombin-stiumlated accumulation of 3-phosphorylated phosphoinositides in a dose-dependent manner (IC50 approximately 10nM), without affecting phospholipase C activation. Pretreatment of CHRF-288 cells with either wortmannin (100 nM) or an unrelated synthetic PI 3-K inhibitor, LY294002 (50 microM), abolishes thrombin-receptor-stimulated blebbing. These results suggest that thrombin-stimulated accumulation of 3-phosphorylated phosphoinositide(s) is required for the shape-change response in CHRF-288 cells.

At Stoke Goldington in the valley of the Great Ouse in Buckinghamshire a river terrace at a height of about 7 m above the floodplain is underlain by fluvial sediments representing climatic fluctuations in the late Middle Pleistocene. Near the base of the succession, at a level only 1 m above the modern floodplain, a fossil assemblage, including pollen, plant macrofossils, molluscs, insects and ostracods, provides evidence for the local development of herb-rich grassland under temperate climatic conditions. The fossil record, amino-acid racemisation ratios and uranium disequilibrium dating all suggest deposition of this material during Oxygen Isotope Stage 7. The deposits containing the temperate assemblage are immediately overlain by typical cold-climate gravels of the Great Ouse. These have been subjected to a later cut-and-fill episode, with the fill accumulating in cool climatic conditions. The cut-and-fill episode was succeeded by aggradation, forming the overlying terrace surface. Amino-acid racemisation ratios indicate that the fill was emplaced, and the terrace surface created, during or after Oxygen Isotope Stage 5. © 1996 John Wiley & Sons, Ltd.

Pollen, molluscan data, and sediment analyses, are presented from Enfield Lock, Middlesex, UK. The pollen data, from organic muds, show similarities with Pre-boreal and Boreal pollen spectra at other sites in the Thames basin; an overlying non-polleniferous marl yielded a diverse molluscan fauna. Radiocarbon dates on organic sediments at the site confirm the pollen records are from the early Holocene, but the shelly marl is less easily dated; there are affinities with molluscan records of the early to mid Holocene from sites elsewhere in southeast England. The biological and sedimentological data chronicle the changing depositional environments of the floodplain of the River Lea during four millennia of the early to mid Holocene. Charcoal records imply that fire was, at times, a significant influence on early Holocene vegetation, but a lack of local human artefacts contrasts with evidence for Mesolithic sites elsewhere, and has implications for the interpretation of early Holocene pollen assemblages from charcoal-rich sediments.

Aminostratigraphies of Quaternary non-marine deposits in Europe have been previously based on the racemization of a single amino acid in aragonitic shells from land and freshwater molluscs. The value of analysing multiple amino acids from the opercula of the freshwater gastropod Bithynia, which are composed of calcite, has been demonstrated. The protocol used for the isolation of intra-crystalline proteins from shells has been applied to these calcitic opercula, which have been shown to more closely approximate a closed system for indigenous protein residues. Original amino acids are even preserved in bithyniid opercula from the Eocene, showing persistence of indigenous organics for over 30 million years. Geochronological data from opercula are superior to those from shells in two respects: first, in showing less natural variability, and second, in the far better preservation of the intra-crystalline proteins, possibly resulting from the greater stability of calcite. These features allow greater temporal resolution and an extension of the dating range beyond the early Middle Pleistocene. Here we provide full details of the analyses for 480 samples from 100 horizons (75 sites), ranging from Late Pliocene to modern. These show that the dating technique is applicable to the entire Quaternary. Data are provided from all the stratotypes from British stages to have yielded opercula, which are shown to be clearly separable using this revised method. Further checks on the data are provided by reference to other type-sites for different stages (including some not formally defined). Additional tests are provided by sites with independent geochronology, or which can be associated with a terrace stratigraphy or biostratigraphy. This new aminostratigraphy for the non-marine Quaternary deposits of southern Britain provides a framework for understanding the regional geological and archaeological record. Comparison with reference to sites yielding independent geochronology, in combination with other lines of evidence, allows tentative correlation with the marine oxygen isotope record., Highlights ► A stratigraphy using the intra-crystalline protein from the calcitic opercula of Bithynia is presented. ► Focused on Britain, but also using samples from a few continental sites, the coverage has been extended back to ∼3 Ma. ► This aminostratigraphy is consistent with independent geochronology, terrace stratigraphy and biostratigraphy. ► The aminostratigraphic framework has been linked to the marine oxygen isotope stratigraphy.

Pleistocene deposits containing the disarticulated skeleton of a mammoth, and associated faunal and floral remains, were discovered in July 1990 at Upper Strensham, Worcestershire. The environmental evidence from the fauna and flora together with limited geological evidence, indicates that the deposits accumulated within a low energy fluvial environment with a surrounding marsh and restricted tree cover on, or close to, the floodplain. The patchy occurrence of trees in a species-rich grassland is discussed, and the climatic significance of the fauna and flora is considered. The Strensham site lies within the valley of the River Avon, which is known to contain at least five altitudinally distinct river terraces. The deposits at Strensham lie beneath a terraced surface that cannot be accommodated within the existing framework of terrace development in the valley, and evidence IS presented which may suggest that these deposits form a previously unrecognised fluvial unit, the Strensham Member of the Avon Valley Formation. Amino-acid age estimates from shells taken from the fossiliferous sediments of the Strensham Member suggest a correlation with Oxygen Isotope Stage 7. This correlation suggests that the temperate deposits at this site should be correlated with the temperate phase recorded at Marsworth, Buckinghamshire and Stoke Goldington in the vafley of the Great Ouse. Journal of Quaternary Science

Pleistocene temperate-climate deposits at Folkestone Battery, Kent are described and attributed to a small stream draining from the nearby Chalk escarpment. Their contained molluscan fauna is indicative of conditions similar to those at the present in southeast England. The occurrence of a mammal fauna with Hippopotamus amphibius (Linne) and of D : L amino-acid ratios from molluscan shell with a mean of 0.124 combine to suggest an age in the Last Interglacial (Oxygen Isotope Substage 5e).

Although molluscan faunas are the most widespread fossil remains in the Chinese loess. there have been very few attempts to use their potential for climatic reconstruction, or to develop cIimato-stratigraphic schemes. This paper reports assemblages of Mollusca from three sites in the North and South Central parts of the Loess Plateau, and evaluates the uses of molluscan faunas as climatic proxies in the S 1 palaeosol, the Malan Loess and S o palaeosol. The molluscan sequence is compared with the record obtained from pedological and magnetic techniques. The current study shows that major peaks in magnetic susceptibility, thought to be due to pedogenesis under warm, humid conditions, can be matched by levels of high molluscan abundance. The occurrence of a sharp molluscan peak within the Malan Loess, otherwise only indicated by a slight increase in magnetic susceptibility, is held to be due to the existence of a short-lived humid episode and demonstrates the sensitivity of Mollusca as indicators of relatively low magnitude climatic shifts not well indicated by other lines of evidence.

Why do no Arthurian figures appear in Dante's circle of Mars in his Paradise, where he encountered the spirits of renowned Christian warriors. Dante knew the stories of Arthur and his knights: were they left out of paradise because he doubted whether their fighting was holy, or because he doubted the purity of their living? Or was it because Arthur's story could find no place in his scheme of providential history?

Late Weichselian and early Holocene partly carbonate-rich sediments from a small lacustrine deposit in Skane, southern Sweden, were analysed for stable carbon and oxygen isotopes and mollusc assemblages. The data from these analyses reveal a pronounced climatic warming at c. 12,400 BP, accompanied by a general change from continental to maritime conditions. Two significant climatic oscillations were identified, dated ate. 12,200-12,000 BP ande. 11,000-10,200 BP. The climatic cooling of the latter, corresponding to the Younger Dryas stadial, may have been initiated well before 11,000 BP. A climatic oscillation of minor amplitude may have occurred around 11,500 BP. Distinct variations in delta(13)C of bulk organic material and shell carbonate are discussed in terms of climatically-induced changes in lake-water chemistry. The general assumption of a positive correlation between delta(18)O of limnic carbonates and mean annual air temperature is questioned. A climatic warming may be associated with a depletion of (18)O in limnic carbonates. Comparisons of palaeoclimatic information from the stable isotope data with that provided by molluscs allow the identification of aspects of climatic and environmental change such as water temperature, water depth, and aquatic vegetation density. Changes in the mollusc assemblage reflect changes in the limnic environment and facilitates the interpretation of stable isotope data. (Less)

The British Quaternary, spanning roughly the past 2.6 million years, is unmatched for the biodiversity and abundance of its fossil localities and its record of climatic contrasts. However, with all but the most recent deposits beyond radiocarbon range, and with no readily datable volcanic rocks, it has been difficult to get accurate dates for many British Pleistocene deposits. Penkman et al. have developed new analytical methods based on the intra-crystalline proteins of stable biominerals (in the 'opercula' shell closure of the freshwater gastropod Bithynia), common in Quaternary deposits. They obtain confident assignments for various strata to global marine isotope stages, securely placing Britain's rich record of faunal and archaeological change into a broader context. Marine and ice-core records show that the Earth has experienced a succession of glacials and interglacials during the Quaternary (last ∼2.6 million years), although it is often difficult to correlate fragmentary terrestrial records with specific cycles. Aminostratigraphy is a method potentially able to link terrestrial sequences to the marine isotope stages (MIS) of the deep-sea record1,2. We have used new methods of extraction and analysis of amino acids, preserved within the calcitic opercula of the freshwater gastropod Bithynia, to provide the most comprehensive data set for the British Pleistocene based on a single dating technique. A total of 470 opercula from 74 sites spanning the entire Quaternary are ranked in order of relative age based on the extent of protein degradation, using aspartic acid/asparagine (Asx), glutamic acid/glutamine (Glx), serine (Ser), alanine (Ala) and valine (Val). This new aminostratigraphy is consistent with the stratigraphical relationships of stratotypes, sites with independent geochronology, biostratigraphy and terrace stratigraphy3,4,5,6. The method corroborates the existence of four interglacial stages between the Anglian (MIS 12) and the Holocene in the terrestrial succession. It establishes human occupation of Britain in most interglacial stages after MIS 15, but supports the notion of human absence during the Last Interglacial (MIS 5e)7. Suspicions that the treeless ‘optimum of the Upton Warren interstadial’ at Isleworth pre-dates MIS 3 are confirmed. This new aminostratigraphy provides a robust framework against which climatic, biostratigraphical and archaeological models can be tested.

Objective— To compare the effects of placebo and GLA on the course of mild diabetic neuropathy over 1 yr. Research Design and Methods— We entered 111 patients with mild diabetic neuropathy from seven centers into a randomized, double-blind, placebo-controlled parallel study of GLA at a dose of 480 mg/day. MNCV, SNAP, CMAP, hot and cold thresholds, sensation, tendon reflexes, and muscle strength were assessed by standard tests in upper and lower limbs. Results— For all 16 parameters, the change over 1 yr in response to GLA was more favorable than the change with placebo, and for 13 parameters, the difference was statistically significant. Sex, age, and type of diabetes did not influence the result, but treatment was more effective in relatively well-controlled than in poorly-controlled diabetic patients. Conclusions— GLA had a beneficial effect on the course of diabetic neuropathy.

A complex of channels underlying the Baginton-Lillington Gravel (Baginton Formation) at Waverley Wood Quarry, Warwickshire is described. Fossil pollen and plant macrofossils, Coleoptera, Ostracoda, Mollusca and Mammalia are described from the channel-fill deposits. Consideration of all the evidence allows the identification of four separate stages of channel fill which largely occurred under a cool temperate climate. At the top of Channel 2 evidence for a cold, continental climatic episode can be recognised, suggesting that the whole complex was deposited under a fluctuating climate at the end of a temperate stage. At two levels in the channels human artefacts were recovered confirming the presence of Palaeolithic people in Warwickshire during the deposition of the sediments. Amino-acid geochronology suggests an age within the ‘Cromerian Complex’ Stage for the channels. The small vertebrate and molluscan faunas indicate that the deposits are no older than the latter part of the ‘Cromerian Complex’ Stage of East Anglia. The regional stratigraphic significance of the Waverley Wood succession is outlined.

This interview with Alexander and Helen Astin addressed their major multi-campus, seven-year study on college students' development of spirituality, focusing on equanimity, one of 10 domains they studied and one for which there was little research available at the time of the study. The Astins also discussed the importance of collegial dialogue to unearth important leads in research, the purpose of their research, the origins of the construct of equanimity and its relationship with other variables, surprising and strong findings, and applications of the spirituality research on campuses.

The International Insulin Foundation (IIF) has developed and validated a needs-assessment instrument called the Rapid Assessment Protocol for Insulin Access (RAPIA) which has been used in seven countries in four continents to analyse the constraints to delivering effective continuing care for people with diabetes. One major contributor to the difficulties in availability of insulin is a failure to use the least costly sources and types of insulin and other effective drugs for diabetes. The purchase of insulins can consume as much as 10% of government expenditure on drugs, this being highly sensitive to the selection of newer analogue insulins as first-choice options, which cost between three and 13 times more than biosynthetic human insulin. Insulin cartridges for use with injection pens further add to costs. Similar considerations apply to most of the newer treatments for people with type 2 diabetes, which may cost up to 40 times more than metformin and sulfonylureas, still considered first-line drugs by European and US guidelines. Both biosynthetic human insulin and the first-line oral hypoglycaemic drugs are available from generic manufacturers. With the present price differentials, there is thus a growing need for countries involved in tendering for sourcing insulin to be provided with the guarantees of Good Manufacturing Practice, quality and bioequivalence, which would come from a WHO Pre-Qualification Scheme as currently exists for a variety of drugs for chronic diseases, both communicable and non-communicable. The IIF has developed a position statement on the provision and choice of diabetes treatments in resource-limited settings which should be applicable wherever consideration of resources is a component of therapeutic decision making.

Responding to media attention on a study of Teach for America (TFA) alumni, this essay summarizes key findings of alumni studies of TFA and AmeriCorps regarding evidence of sustained civic behavior in relationship to young adults’ search for meaning and purpose. Consideration is given to different definitions of civic engagement and what is “enough” civic engagement. It closes with questions regarding the role of reflection and spiritual development in discerning vocational calling and sustaining civic engagement.

The most recent column of “New Scholars and Scholarship” focused on a scholarly exchange that emerged at a recent Symposium on Assessing Students’ Civic Outcomes hosted by the Indiana University–Purdue University Indianapolis (IUPUI) Center for Service and Learning. The event was cosponsored by the National Service Learning Clearinghouse and the American Association of State Colleges and Universities’ (AASCU) American Democracy Project. Symposium participants were asked to present and analyze studies of recent studies of civic engagement in hopes of possible collaboration. This issue’s column follows through on the challenge presented by the Symposium. It compares several survey projects’ choices of measures of civic dialogue, seeking to understand the purpose of the survey, what is being measuring, examples of survey questions, strong predictors or correlations.

The ability to rapidly and specifically regulate protein activity combined with in vivo functional assays and/or imaging can provide unique insight into underlying molecular processes. Here we describe the application of chemically induced dimerization of FKBP to create nearly instantaneous high-affinity bivalent ligands capable of sequestering cellular targets from their endogenous partners. We demonstrate the specificity and efficacy of these inducible, dimeric “traps” for the dynein light chains LC8 (Dynll1) and TcTex1 (Dynlt1). Both light chains can simultaneously bind at adjacent sites of dynein intermediate chain at the base of the dynein motor complex, yet their specific function with respect to the dynein motor or other interacting proteins has been difficult to dissect. Using these traps in cultured mammalian cells, we observed that induction of dimerization of either the LC8 or TcTex1 trap rapidly disrupted early endosomal and lysosomal organization. Dimerization of either trap also disrupted Golgi organization, but at a substantially slower rate. Using either trap, the time course for disruption of each organelle was similar, suggesting a common regulatory mechanism. However, despite the essential role of dynein in cell division, neither trap had a discernable effect on mitotic progression. Taken together, these studies suggest that LC occupancy of the dynein motor complex directly affects some, but not all, dynein-mediated processes. Although the described traps offer a method for rapid inhibition of dynein function, the design principle can be extended to other molecular complexes for in vivo studies.

Interglacial deposits on the south side of Peterborough have yielded a diverse flora and fauna which lived in an estuarine environment that was affected by marine transgression and regression. Fossils described from six sequences indicate that the deposits accumulated under fully temperate conditions. The Woodston Beds have a diversity of fossils (pollen, plant macrofossils, molluscs, ostracods, insects and mammals) which allows their palaeoecological relationships to be examined, and compared with those of other sites of similar age. The environmental reconstructions based on the individual taxa, although emphasising differing facets of the habitat, are in broad agreement. Some slight discrepancies arise from the assumption that the organisms are characteristic of the sedimentary environment in which they are found. In fact many of the fossils have been transported to the site of deposition from nearby habitats. Evidence of a closed canopy forest with associated land environments, is provided by the plant remains and the land molluscs, and to a lesser extent by the insects and the mammals. A large, slow- flowing river, with adjacent marsh and meadow areas is also suggested by the taxa of molluscs, ostracods and insects present. Molluscs and ostracods show clearly the presence of marine influences between 11 and 14 m Ordnance Datum . The climate under which the Woodston Beds were deposited was slightly warmer than the present. An age in the Hoxnian Interglacial of the Middle Pleistocene is proposed.

To clarify the function of the receptor binding protein for inositol hexakisphosphate (IP6), we obtained a partial amino acid sequence from the purified protein and a partial nucleotide sequence from a cDNA clone of the gene. The sequences are essentially identical to those of the alpha-subunit of the clathrin assembly protein AP-2. The IP6 receptor protein analyzed by SDS-PAGE contains a series of subunits which are the same as those of AP-2. Antibodies to AP-2 react with the IP6 receptor protein in immunoblot analysis.