bluuebunny/crossref_metadata_2025 huggingface dataset:
Supergene processes in galena-replacement mineralization from the Longstone Edge vein system, Derbyshire
Authors: Jeffrey C. A.
Published: December 2009

The occurrence of an unusual galena-rich replacement flat with a well developed supergene assemblage, from the South Pennine Orefield, has been investigated. The reason for a galena-rich flat at this location has not been ascertained but the form of the deposit demonstrates a combination of lithological and structural controls. The main factors in producing a sulphate-dominant supergene assemblage have been the presence of a quartz and fluorite replacement halo to prevent buffering of weakly acidic meteoric solutions, an absence of primary calcite mineralization and the downward, within-the-vein, as opposed to in-limestone, flow of meteoric water. The deposit has initially evolved more like a ‘silicate rock-hosted’ than a carbonate-hosted deposit. The coarse anglesite crystal size, and its isolation from the associated galena, indicates unusually high and prolonged mobility of lead due to the long term stability of the supergene system during the presence of the Namurian shale cover. The deposit reverted to a more typical cerussite stability field on removal of the shale cover as limestone-equilibrated fluids, rich in dissolved carbonate, entered the flat.
An assessment of copper mineralization from the Great Orme Mine, Llandudno, North Wales, as ore in the Bronze Age
Authors: Ixer R. A.
Published: December 2009

Spoil heap and
in situ
mineralization from the Great Orme Mines, North Wales, have been classified into six mineral associations. By applying mineralogical, mining and beneficiation criteria, their probable exploitation as copper ores in the Bronze Age have been assessed. Major veins and open voids within dolostones are infilled by saddle dolomite–chalcopyrite–pyrite–calcite–malachite. The tonnage, estimated copper grade of 10% and continuity of the veins, plus the coarse grain-size of the copper-bearing minerals, suggest that the veins were mined in the Bronze Age possibly accompanied by contributions from adjacent void-infilling mineralization. Two minor types of mineralization, namely ‘copper ddu ore’, a very fine-grained, friable, limonitic vein-infilling, and disseminated,
c.
1 cm diameter, azurite nodules in mudstones, may have been taken as a by-product of other mining operations. Neither the fine-grained, disseminated, Cu-, Pb-, Fe-, Co-, Ni-rich, polymetallic sulphides, which are only found in dolostones from the spoil, nor the single, copper-poor, but galena-rich assemblage found as a vein-infilling, can be considered to be Bronze Age copper ores. These last two associations belong to the Mississippi Valley-style lead–zinc mineralization of the North-east Wales Orefield that is older in age and differently sourced from the copper–dolomite association ores that produced Bronze Age copper metal. The recognition and sampling of ores, rather than mineralized specimens, from a mine site, have implications for geochemical or isotopic provenance studies that lie far beyond the Great Orme. This is because only run-of-the-mill ores should be treated as having any importance to archaeometallurgists.
Mineral assemblages formed in Oxford Clay fired under different time–temperature conditions with reference to brick manufacture
Authors: Dunham A. C. , McKnight A. S. , Warren I.
Published: December 2009

Time–temperature–transformation (TTT) diagrams have been determined for high-lime (10.2%) and moderate-lime (5.2%) bulk raw materials from the Peterborough Member of the Oxford Clay Formation of King’s Dyke [TL 525 297] and Orton [TL 517 293] brickworks. Study of the chemistry and mineralogy of the brickclays provides the starting point for 79 firing experiments on each raw material, at temperatures between 800 and 1100°C, and for firing times at maximum temperature from 15 minutes to 336 hours. Quantified X-ray diffraction of each fired briquette enables individual TTT diagrams to be constructed for each phase. Finally, a summary diagram shows the distribution of mineral phase assemblages in time–temperature space. The original mineralogy (quartz, illite, kaolinite, chlorite, calcite, aragonite, K-feldspar, albite, pyrite, gypsum, anatase and apatite) changes on heating to a mixture of calc-silicates (anorthite, melilite and pyroxene) with quartz, hematite, anhydrite and glass in commercial bricks and also wollastonite and cordierite when longer firing times and temperatures are used. The mineralogical changes can be followed in quantified equations using the actual compositions and quantities of the phases. The calc-silicates are produced by lime (from calcite) reacting with the clay minerals or their breakdown products such as metakaolinite. The glass has granitic affinities. The data provide a case for considering shorter commercial firing times.
Origin of some slope-foot debris accumulations in the Skiddaw upland, northern Lake District
Authors: Clark R. , Wilson P.
Published: December 2009

Descriptions and interpretations of two previously unrecorded slope-foot debris accumulations in the Skiddaw upland of the northern Lake District are presented. Debris ridges below Ling Thrang Crags in the River Caldew valley are considered to be part of a terminal moraine constructed by a Loch Lomond Stadial (LLS) (11-10 k
14
C years BP) glacier. Acceptance of a glacial origin increases the number of identified glaciers and area covered by LLS ice in this part of the Lake District. Immediately west of the glacier site there are periglacial boulder accumulations, regarded as contemporary with the glacier. A debris bench in Grainsgill valley is interpreted as a composite feature consisting of alluvial valley-fill sediments and debris supplied from the flanking hillside. Later, fluvial incision also helped to shape the bench. Construction of the bench followed removal of Dimlington Stadial ice (by 14.5-13.5 k
14
C years BP) and probably continued throughout the Windermere Interstadial (14-11 k
14
C years BP) and LLS. The bench is regarded as a paraglacial phenomenon. Similar composite forms have yet to be reported from elsewhere in the uplands of the British Isles, although the bench is unlikely to be unique.
The graptolitic age of the type Ashgill Series (Ordovician), Cumbria, UK
Authors: Rickards R. B.
Published: December 2009

The Rawtheyan Stage of the type Ashgill Series, in Westerdale, Cumbria, is shown to be of
linearis
Biozone age, largely on the basis of extensive new graptolite collections. This is the only reliable graptolite dating of the type Ashgill, although it is possible that the underlying Cautleyan Stage is also of
linearis
Biozone age. There is no direct evidence for the
complanatus, anceps, extraordinarius
and
persculptus
biozones, although these could equate roughly with the top of Ingham’s (1966) zone 7 and his zone 8, the latter embracing the Ashgill (Shales) Formation. A total of 26 graptolite taxa have been identified in the type Ashgill Series, from 26 localities, many of them new.
Dicellograptus praeanceps
sp. nov. is described.
Late Devensian glaciation, ice-dammed lake and river diversion, Stiffkey, north Norfolk, England
Authors: Brand D. , Booth S. J. , Rose J.
Published: December 2009

A sequence of disturbed and undisturbed samples from a borehole drilled at Warham, near Stiffkey in north Norfolk, is described and sub-divided into three lithofacies on the basis of sedimentary structures, particle size distribution, calcium carbonate content, selected heavy mineral composition and indicator lithologies. These properties are used to determine the environment of deposition and establish correlation with glaciogenic deposits elsewhere. The basal sands and gravels (Lithofacies A) overlie the Chalk bedrock and are interpreted as having formed by a braided River Stiffkey that flowed northward through the site in pre-Late Devensian periglacial conditions. Lithofacies B consists of >8 m of laminated sands, silts and clays that were formed in a proglacial lake created by the obstruction of the River Stiffkey when the Late Devensian (Dimlington Stadial) glaciation reached the north Norfolk coast. These sediments are covered by gravelly sands (Lithofacies C), which were deposited as an ice-marginal river deposit as part of the Late Devensian end moraine-ridge complex. Finally, the lake drained and the sediments were dissected as the diverted River Stiffkey adopted a new course to the north-east and the lower, incised section of the present Stiffkey valley was formed.
A well-preserved early Namurian ammonoid fauna with
Cravenoceras leion
Bisat 1930 from Backdale Mine, Hassop, Derbyshire, England
Authors: Korn D. , Tilsley J. W.
Published: December 2009

The
Cravenoceras leion
Marine Band at Backdale Mine has yielded a stratigraphically important ammonoid fauna consisting of the species
Cravenoceras leion
Bisat 1930,
Edmooroceras medusa
(Yates 1961) and
Girtyoceras
sp.
C. leion,
in particular, is represented by well preserved material, allowing the description of the entire ontogeny. It is demonstrated that the conch geometry of this species undergoes major transformations, and that the suture line is characteristic of the genus
Cravenoceras.
Based on the ontogenetic development of the suture line, a clear separation can be made from the Rhenish species
Emstites schaelkensis
(Brüning 1923).
Ichthyosaurs and plesiosaurs from the Lower Spilsby Sandstone Member (Upper Jurassic), north Lincolnshire
Authors: Forrest R. , Oliver N.
Published: December 2009

The Lower Spilsby Sandstone Member (Upper Jurassic, Portlandian) of the Spilsby Sandstone Formation, north Lincolnshire, has yielded an assemblage of small marine reptiles, including an ichthyosaur and several plesiosaur taxa. All the specimens are from a small area of a quarry near Nettleton, possibly from beds deposited in a small lagoon cut off from the open sea. The fauna is characterized by the small size of the individual animals, and by morphological characteristics that are closer to those of Lower Cretaceous Wealden taxa than to the better known Upper Jurassic fauna that is typically found in deeper water environments.
Reference sections of faunal bands in the Lower Coal Measures Formation at Elland, west Yorkshire, UK
Authors: Wilson A. A. , Chisholm J. I.
Published: December 2009

Three former quarries and a working quarry near Elland, west Yorkshire, have recently provided detailed sections in the lowest part of the Coal Measures Group. Exposure extends from about 24 m above the Subcrenatum Marine Band to the lower beds of the Elland Flags. There are eight marine bands, four of which are new records for the Elland area. Numerous non-marine bivalve beds (‘mussel bands’) are also present in the succession, including one below the Hard Bed Coal that is new to the area. The composition of each faunal band is listed, together with a summary of earlier findings by other authors.
Structure and sequence of the Ingleton Group, basement to the central Pennines of northern England
Authors: Soper N. J. , Dunning F. W.
Published: December 2009

The Ingleton Group is a sequence of steeply dipping turbiditic greywackes that crops out in two of the Craven inliers at the southern margin of the Askrigg Block, at Ingleton and in Ribblesdale. The structure has previously been interpreted as a series of concertina-like isoclinal folds, much more intense than the deformation recorded in Late Ordovician–Silurian strata of the overlying Windermere Supergroup. For this reason, the Ingleton Group was long regarded as late Precambrian in age. In 1982 the British Geological Survey (then Institute of Geological Sciences) assigned it to the early Ordovician on the basis of an acritarch assemblage recovered from a single borehole sample.

This paper reports a resurvey based on the ample wayup evidence provided by turbidite bedforms. The greywackes are disposed in a large isoclinal fold pair, the previously recognized Skirwith Syncline in the Ingleton Inlier and the Horton Anticline mapped in Ribblesdale. Some 3 km of strata are exposed on the common limb, and assigned to five lithofacies. A start has been made on lithostratigraphical subdivision, three formations being recognized in the uppermost part of the succession.

Isoclinal folding of the Ingleton Group predates the Acadian (Devonian) deformation of the overlying Silurian strata; the Acadian cleavage is superimposed obliquely across the isoclines and faces down on their inverted limbs. The group records a prelate Ordovician history comprising the deposition of penecontemporaneous continental volcanic arc detritus in a substantial turbidite basin, intrusion of mafic dykes, major folding and low-grade metamorphism, followed by deep erosion.

Uncertainty about the depositional age of the Ingleton Group presents problems as to its affinities. Lithofacies and provenance characteristics match late Neoproterozoic Avalonian interarc basin deposits in the English Midlands and Welsh Borderland, but not the apparently contemporaneous Ordovician Skiddaw and Manx groups. Confirmation of an early Ordovician age would suggest that the deformation history of the Ingleton Group matches that of the Monian Supergroup of Anglesey. The problem is discussed in the context of Ordovician terrane assembly.
Stratigraphical revision of the Windermere Supergroup (Late Ordovician–Silurian in the southern Howgill Fells, NW England
Authors: Rickards R. B. , Woodcock N. H.
Published: December 2009

Lithostratigraphical and biostratigraphical revisions are reported within the classic Windermere Supergroup succession of the southern Howgill Fells of Cumbria, and a review is provided of the depositional environment of this Late Ordovician and Silurian foreland basin sequence. In particular, a number of key marker beds are described and better located, both geographically and stratigraphically. These markers include: (a) a unit of conglomerate and sandstone, probably syn-glacial, in the upper (Ashgill) part of the Dent Group; (b) the basal, carbonate, Spengill Member (uppermost Ashgill) of the Stockdale Group; (c) the ‘Green Streak’ oxic mudstone higher in the Skelgill Formation (Llandovery) of the same group; (d) the ‘Red Beds’ – newly defined as the Hebblethwaite Member – in the Browgill Formation of the Stockdale Group; and (e) the oxic Coldwell Formation within the predominantly anoxic Tranearth Group (Wenlock). The thick, turbiditic Coniston Group is divided using thin-bedded units rich in anoxic hemipelagic mudstone, and its biostratigraphical zonation and transition into the Bannisdale Formation is better defined. The graptolite
Saetograptus soperi
sp. nov. is described, and shown to characterize a new biozone below the
leintwardinensis
Biozone. The revised division of the Coniston Group allows a new correlation of the group across NW England, defining turbidite system architectures that imply control of sedimentation by syndepositional faults.
Foraminifera, calcareous algae and rugose corals in Brigantian (late Viséan) limestones in NE Ireland
Authors: Cózar P , Somerville H. E. A. , Somerville I. D.
Published: December 2009

Upper Viséan rocks in the Kingscourt, Armagh and Cookstown areas of NE Ireland are dated using foraminifera, calcareous algae and rugose corals, and new positions are proposed for the Asbian/Brigantian and early/late Brigantian boundaries. Of particular interest are assemblages of foraminifera and calcareous algae from the Poulmore Scarp section (Kingscourt), which is now recognized as the only section in Ireland to be composed of platform carbonates of latest Brigantian age. This late Brigantian section is correlated with the interval from the Three Yard Limestone to the Great Limestone in northern England.
An unusual crinoid-coral association from the Lower Carboniferous of Clitheroe, Lancashire
Authors: Donovan S. K. , Lewis D. N. , Kabrna P.
Published: December 2009

A well-preserved calyx of the monobathrid camerate crinoid
Amphoracrinus gilbertsoni
(Phillips) from the Lower Carboniferous (Chadian, Viséan) of Salthill Quarry, Clitheroe, Lancashire, is preserved in close association with a solitary rugose coral. Evidence for the coral being an epizoozoan on the crinoid includes its perpendicular orientation to the calyx, its position at the base of a free arm (B ray) in the AB interray, breakage of the crinoid plates around the coral (calyx ligamentation had not rotted post-mortem), and a growth deformity in the AB interray. The position of the coral indicates that, in life, it was elevated above the sea floor and directed into the prevalent water current by the crinoid. Its position, adjacent to a free arm and growth deformity of the AB interray suggest it was also a parasite on the adoral groove of the crinoid arm.
Late Triassic (Rhaetian) palynomorphs from near York, North Yorkshire, UK
Authors: Warrington G.
Published: December 2009

A borehole near Strensall has yielded an assemblage of terrestrial and marine palynomorphs of Late Triassic (Rhaetian) age. The borehole includes beds of the Westbury Formation (Penarth Group), and being less than 10 km NNE of York, is the closest proving of that unit to the city.
A review of joints (cleats) in British Carboniferous coals: indicators of palaeostress orientation
Authors: Rippon J. H. , Ellison R. A. , Gayer R. A.
Published: December 2009

Joints in coals, arranged (sub) normal to bed boundaries, are commonly termed cleats. Cleat azimuths in Carboniferous coals are reviewed, and are interpreted as reflecting Variscan stress fields across different tectonic settings. Immediately proximal to the Variscan Front (South Wales, Kent), varied cleat azimuths provide evidence of stress deflection and block rotation, whereas north of the Wales-Brabant High (central and northern England), a consistent regional north-westerly maximum horizontal stress is indicated by regionally parallel cleat orientations in most coalfield areas. In the more distal Midland Valley of Scotland, varied cleat azimuths suggest that local structural developments had a significant effect on the stress field. Throughout Britain, major fault zones separate differing cleat sets, suggesting deep crustal compartmentalization during Carboniferous times. In all areas, most main fault movements post-dated the majority of cleats.
An investigation of some sediment-filled fractures within redbed sandstones of the UK
Authors: Hough E. , Pearce J. M. , Kemp S. J. , Williams G. M.
Published: December 2009

Permo-Triassic sandstones form the most important aquifer in northern England. These sandstones are susceptible to contamination from a legacy of industrial development, associated with the expansion of urban areas that include Liverpool, Manchester, Birmingham, Nottingham and Teesside. The permeability of the sandstone is derived from the intergranular pore spaces and fractures. However, unconsolidated sediment found within fractures can have a profound effect on fluid flow, depending on whether it is clay or sand. Sediment-filled fractures are not well described in the literature; consequently there are few observations or measurements of the hydraulic properties of these features that would enable an assessment to be made of their hydro-geological significance, and it is unclear how they should be included in solute transport models. A field survey was undertaken to test whether sediment-filled fractures are a common feature within redbed sandstone terrains. Exposures from most of the main UK Permo-Triassic sedimentary basins, and some from the Devonian Old Red Sandstone in south Wales, were examined. The field survey, which included surface and underground tunnel exposures, enabled the investigation of both unweathered and weathered examples of sediment-filled fractures. Detailed mineralogical and petrographical analysis of fracture fills and host rock indicate that, in some cases, fills are historic, and that there is a component to some fills that indicates a glacial origin. Where the fill is unconsolidated, sediment may be flushed from fractures; this may explain why some water wells abstracting from the Permo-Triassic sandstones of the UK pump large quantities of sand throughout their active life, and this may be a contributory factor to the observation that transmissivity around abstraction wells in sandstone can increase with time. It is likely that, in certain circumstances, sediment-filled fractures may locally alter fluid migration paths through sandstones, which has important implications for the transport of both dissolved contaminants and hydrocarbons.
Reconstructions of the Late Devensian (Dimlington Stadial) British-Irish Ice Sheet: the role of the upper Tees drumlin field, north Pennines, England
Authors: Mitchell W. A.
Published: December 2009

It has long been known that the upland areas of the Pennines, northern England, were a local ice source during the Late Devensian (Dimlington Stadial) glaciation of Britain. However, there has been little detailed work on their significance for ice sheet reconstructions. The presence of drumlins at high elevations within the northern Pennines is reported from the upper reaches of the Tees valley and Harwood Beck. Geomorphological mapping has identified 134 drumlins occurring up to an elevation of 662 m OD in association with superimposed drumlins and drift tails. These landforms, particularly the presence of superimposed forms, enable the reconstruction of two ice flow events associated with a local ice centre that formed during the Late Devensian glaciation in northern England. The earlier flow event was directed straight down the upper Tees valley from a limited source area on the high ground to the east of Cross Fell. The later event indicates a flow direction more transverse to the valley, from a more extensive source area that had migrated and expanded westwards across the high plateau of Cross Fell and southwards towards Dufton Fell. The presence of drumlins at this high altitude indicates sufficient ice thickness to allow basal deformation and suggests that drumlin upper elevation defines a thermal regime above which the plateau ice field was cold based and frozen to the bed. This requires the area to be completely covered by ice. This study demonstrates the importance of these upland areas in detailed reconstructions of a multi-domed, British-Irish Ice Sheet (BIIS).
Late Holocene debris cone development and vegetation and land-use history in the Pasture Beck valley, Lake District, NW England
Authors: Clark R. , Parker A. G. , Anderson D. E. , Wilson P.
Published: December 2009

Investigations of a sedimentary sequence exposed in the distal margin of a small debris cone in the valley of Pasture Beck, eastern Lake District, have yielded detailed information concerning the time and nature of cone aggradation phases and the local vegetation and land-use history. Radiocarbon dates from two buried peat beds indicate that the cone surface was generally stable from the late 8
th
to the early 13
th
centuries AD (1165–736 cal. BP). An interlude of colluvial gravel deposition interrupted peat accumulation and was probably the result of a single short-lived event. Gravel-dominated beds represent deposition of reworked rockfall debris and glacial drift by cohesionless debris flows, whereas finer-grain beds are probably the result of sheet-flows derived by washout of fines from debris-flow deposits. The stratigraphic evidence indicates that the minerogenic sediments accumulated in quick succession. Pollen and charcoal data from peat samples reveal intensification of land-use before burial of the peats by minerogenic sediments. It is proposed that landscape instability was associated first with Norse-Irish settlement and woodland clearance, and later, probably, to the expansion of upland pastures and more intensive grazing in the 13
th
century AD. When the Pasture Beck data is considered along with information from elsewhere in the British Isles, it is apparent that not all patterns of Late Holocene landscape change in upland areas can be ascribed to a single cause.
The glacial stratigraphy of lowland southern and eastern Britain: temperate-stage deposits at Morston and Kirmington
Authors: Gale S. J. , Hoare P. G.
Published: December 2009

The recent suggestion that no warm-stage deposits have yet been found separating glacial sediments in lowland southern and eastern Britain is shown to be incorrect. At Morston, on the coast of north Norfolk, an ancient beach succession with a temperate pollen assemblage rests upon till closely comparable with the Marly Drift, usually considered to be of Anglian age, and is overlain by Late Devensian Hunstanton Till. At Kirmington, in NE Lincolnshire, estuarine silts containing a thin peat bed with a limited temperate pollen spectrum separate tills assigned to the Anglian and Late Devensian stages.
A marine reptile fauna from the Early Jurassic Saltford Shale (Blue Lias Formation) of central England
Authors: Smith A. S. , Radley J. D.
Published: December 2009

A previously undocumented marine reptile fauna comprising well-preserved ichthyosaur and plesiosaur remains is described from the Early Jurassic Saltford Shale Member within the Blue Lias Formation of central England. Two ichthyosaur genera are recognized, namely
Leptonectes
and
Ichthyosaurus,
as well as generically indeterminate remains of plesiosaurs. The specimens include partly-articulated skeletons, reflecting preservation in dysaerobic argillaceous sediment in a dominantly low-energy setting on the English East Midlands Shelf.
Ostracods, ancient and modern: a review of John Neale’s scientific contribution
Authors: Lord A. R. , Horne D. J.
Published: December 2009

During a professional career of 42 years, John Neale published 106 scientific papers and book chapters, and edited 5 books, mainly concerning the bivalved crustacean group Ostracoda. Although dominantly taxonomic in nature, this body of work encompasses an extraordinary range of material, both living and fossil, from late Jurassic to modern in age, from a range of marine and non-marine environments, and demonstrates a pioneering combination of palaeontological and zoological methods.
Regional evolution of a fluviodeltaic cyclic succession in the Marsdenian (late Namurian Stage, Pennsylvanian) of the Central Pennine Basin, UK
Authors: Waters C. N. , Chisholm J. I. , Benfield A. C. , O’Beirne A. M.
Published: December 2009

Basin-wide analysis of sedimentary facies, isopachytes and palaeocurrents for two late Marsdenian (Pennsylvanian) sedimentary cycles within part of the Millstone Grit Group, has led to a new sequence-stratigraphic interpretation of the relationships between its constituent sandstone units (currently named the Huddersfleld White Rock, Chatsworth Grit, Brooksbottoms Grit, Holcombe Brook Grit, Brown Edge Flags and Redmires Flags). The
Bilinguites superbilinguis
(R
2c
1) and
Verneulites sigma
(R
2c
2) marine bands are related to fourth-order marine highstands, and show faunal variations that possibly reflect fifth-order sea-level fluctuations. The lower R
2c
1 cycle consists entirely of relatively deep water (basin floor) mudstone. The overlying R
2c
2 cycle shows an upward regressive passage from similar mudstone through pro-delta and delta-slope deposits to mouthbar and channel sandstones. The latter comprises an ‘eastern inflow’ of northerly provenance, the distribution of which was not influenced by the underlying basement configuration, and a ‘southern inflow’ sourced from the Wales-Brabant High. Falling sea-levels resulted in progressive narrowing of the fluvial pathway within the ‘main sandstone body’ of the ‘eastern inflow’, with a concomitant increase in flow velocities and grainsize. At lowstand, this culminated in the Chatsworth palaeovalley, 25 km wide, the basal surface of which can be correlated into the interfluve areas as a leached palaeosol. ‘Higher sandstone bodies’, where developed, are of two kinds: an earlier set present outside the palaeovalley was formed during regression, and a later set within the palaeovalley was formed as sea level rose. As part of this transgressive systems tract, a
Lingula
band developed across the flooded Chatsworth palaeovalley and its interfluve margin. The transgression culminated in the highstand of the
Cancelloceras cancellatum
(
G
1a
1) Marine Band.
The holotype of the trigonotarbid arachnid
Maiocercus orbicularis
Gill, 1911, a junior synonym of
M. celticus
(Pocock, 1902)
Authors: Craven D. J. , Dunlop J. A.
Published: December 2009

The recently rediscovered holotype of the fossil arachnid
Maiocercus orbicularis
Gill, 1911 (Arachnida: Trigonotarbida), from the Upper Carboniferous (Pennsylvanian, Westphalian A) of Westhoughton near Bolton, is described and figured from its repository in the Bolton Museum. Its status as a junior synonym of
Maiocercus celticus
(Pocock, 1902) is confirmed.
Lateglacial vegetation change in East Yorkshire: a radiocarbon dated pollen sequence from Routh Quarry, Beverley
Authors: Gearey B. R.
Published: December 2009

Pollen and radiocarbon analyses of Lateglacial Interstadial deposits from Routh Quarry, East Yorkshire, indicate the growth of open, herb-rich grassland vegetation during the early part of the Interstadial. The subsequent expansion of birch and juniper scrubland appears to have been accompanied by a brief period of landscape stability prior to a contraction in both taxa, probably as a result of a climatic cooling. A series of fluctuations in the representation of birch during the later part of the Interstadial may likewise be related to periods of climatic cooling identified in other proxy records from Britain and Europe. Successional processes at the site resulted in the growth of a brown moss fen, which in turn led to changes in the representation of certain pollen taxa, possibly connected to taphonomic factors resulting from changes in pollen source area as much as actual vegetation change. The transition to the Loch Lomond Stadial is not clearly resolved palynologically, but appears to have led to the destabilization of local soils and the deposition of a clay-silt layer over the fen deposits.
The cladid crinoid
Gissocrinus
Angelin from Wenlock Edge, Shropshire (Silurian)
Authors: Donovan S. K. , Lewis D. N. , Veltkamp C. J.
Published: December 2009

Complete fossil crinoids are well known from the Much Wenlock Limestone Formation (Silurian, Wenlock, Homerian), but are only common in the Dudley area of the West Midlands. Elsewhere, Wenlock crinoids are preserved as disarticulated ossicles. For example, only about six nominal crinoids are known from the type area of the Much Wenlock Limestone Formation on Wenlock Edge. Herein, we document abundant remains of the cladid crinoid
Gissocrinus
spp. from near Much Wenlock, Shropshire, based on common brachial and rare radial ossicles. Brachials are mainly thin and quadrate with a U-shaped adoral groove. There are six nominal species of
Gissorcrinus
in the Wenlock of the British Isles; probability suggests that this sample contains elements of more than one species.
p38 MAPK links oxidative stress to autophagy-related gene expression in cachectic muscle wasting
Authors: McClung J. M. , Judge A. R. , Powers S. K. , Yan Z.
Published: December 2009

Oxidative stress is a primary trigger of cachectic muscle wasting, but the signaling pathway(s) that links it to the muscle wasting processes remains to be defined. Here, we report that activation of p38 mitogen-activated protein kinase (MAPK) (phosphorylation) and increased oxidative stress ( trans-4-hydroxy-2-nonenal protein modification) in skeletal muscle occur as early as 8 h after lipopolysaccharide (1 mg/kg) and 24 h after dexamethasone (25 mg/kg) injection (intraperitoneal) in mice, concurrent with upregulation of autophagy-related genes, Atg6, Atg7, and Atg12. Treating cultured C2C12 myotubes with oxidant hydrogen peroxide (4 h) resulted in increased p38 phosphorylation and reduced FoxO3 phosphorylation along with induced Atg7 mRNA expression without activation of NF-κ B or FoxO3a transcriptional activities. Furthermore, inhibition of p38α/β by SB202190 blocked hydrogen peroxide-induced atrophy with diminished upregulation of Atg7 and atrogenes [muscle atrophy F-box protein ( MAFbx/Atrogin-1) , muscle ring finger protein 1 ( MuRF-1), and Nedd4]. These findings provide direct evidence for p38α/β MAPK in mediating oxidative stress-induced autophagy-related genes, suggesting that p38α/β MAPK regulates both the ubiquitin-proteasome and the autophagy-lysosome systems in muscle wasting.
Hexosamine biosynthesis pathway flux promotes endoplasmic reticulum stress, lipid accumulation, and inflammatory gene expression in hepatic cells
Authors: Sage Andrew T , Walter Lisa A , Shi Yuanyuan , Khan Mohammad I. , Kaneto Hideaki , Capretta Alfredo , Werstuck Geoff H.
Published: December 2009

There is increasing evidence that endoplasmic reticulum (ER) stress contributes to the development of atherosclerosis in diabetes mellitus. The purpose of this study was to determine the effects of increased hexosamine biosynthesis pathway (HBP) flux on ER stress levels and the complications of ER stress associated with diabetes and atherosclerosis in hepatic cells. Glutamine:fructose-6-phosphate amidotransferase (GFAT), the rate-limiting enzyme of the HBP, was overexpressed in HepG2 cells by use of an adenoviral expression system. The ER stress response and downstream effects, including activation of lipid and inflammatory pathways, were determined using real-time PCR, immunoblot analysis, and cell staining techniques. GFAT overexpression resulted in increased expression of ER stress markers, including Grp78, Grp94, calreticulin, and GADD153, relative to cells infected with an empty adenoviral vector. In addition, GFAT overexpression promoted lipid, but not cholesterol, accumulation in hepatic cells as well as inflammatory pathway activation. Treatment with 6-diazo-5-oxo-norleucine, a GFAT antagonist, blocked the effects of GFAT overexpression. Consistent with our in vitro data, hyperglycemic mice presented with elevated markers of hepatic ER stress, glucosamine and lipid accumulation. Together, these data suggest that HBP flux-induced ER stress plays a role in the development of hepatic steatosis and atherosclerosis under conditions of hyperglycemia.
High basal cell surface levels of fish GLUT4 are related to reduced sensitivity of insulin-induced translocation toward GGA and AS160 inhibition in adipocytes
Authors: Capilla Encarnación , Díaz Mònica , Hou June Chunqiu , Planas Josep V. , Pessin Jeffrey E.
Published: December 2009

Glucose entry into cells is mediated by a family of facilitative transporter proteins (GLUTs). In mammals, GLUT4 is expressed in insulin-sensitive tissues and is responsible for the postprandial uptake of glucose. In fish, GLUT4 also mediates insulin-regulated glucose entry into cells but differs from mammalian GLUT4 in its affinity for glucose and in protein motifs known to be important for the traffic of GLUT4. In this study, we have characterized the intracellular and plasma membrane (PM) traffic of two orthologs of GLUT4 in fish, trout (btGLUT4) and salmon (okGLUT4), that do not share the amino terminal FQQI targeting motif of mammalian GLUT4. btGLUT4 (FQHL) and, to a lesser extent, okGLUT4 (FQQL) showed higher basal PM levels, faster traffic to the PM after biosynthesis, and earlier acquisition of insulin responsiveness than rat GLUT4. Furthermore, btGLUT4 showed a similar profile of internalization than rat GLUT4. Expression of the dominant-interfering AS160-4P mutant caused a significant decrease in the insulin-induced PM levels of okGLUT4 and rat GLUT4 and, to a lesser extent, of btGLUT4, suggesting that btGLUT4 has reduced retention into the IRC. Contrary to rat GLUT4 and okGLUT4, the presence of btGLUT4 at the PM under insulin-stimulated conditions was not affected by coexpression of a dominant-interfering GGA mutant. These data suggest that fish GLUT4 follow a different trafficking pathway to the PM compared with rat GLUT4 that seems to be relatively independent of GGA. These results indicate that the regulated trafficking characteristics of GLUT4 have been modified during evolution from fish to mammals.
Effects of sildenafil on maternal hemodynamics and fetal growth in normal rat pregnancy
Authors: Sasser Jennifer M. , Baylis Chris
Published: December 2009

It has been suggested that the phosphodiesterase-5 (PDE5) inhibitor sildenafil may be useful in the treatment of hypertension during pregnancy. However, we have reported a selective increase in renal inner medullary PDE5 that participates in the sodium retention of pregnancy. Therefore, the purpose of this study was to determine whether oral sildenafil treatment impairs maternal plasma volume expansion and/or fetal growth during rat pregnancy. Rats received sildenafil (10 mg·kg−1·day−1, 50 mg·kg−1·day−1, or 90 mg·kg−1·day−1) or vehicle on days 4–20 of pregnancy. On days 14–19, rats were housed in metabolic cages for collection of urine and measurement of food and water intake. Terminal hemodynamic and fetal measurements were taken on day 20. None of the sildenafil doses lowered blood pressure, and although all doses increased plasma cGMP concentrations, only the highest dose increased aortic and inner medullary cGMP content. Sildenafil had no effect on maternal weight gain; however, the highest dose decreased both plasma volume and renal sodium retention. The pup number and size were similar among the groups. Therefore, these studies suggest that low doses of systemic sildenafil may be safe during pregnancy in the rat, but higher doses may interfere with the physiological sodium retention and volume expansion of pregnancy. The effects of systemic sildenafil on blood pressure and sodium retention during hypertension in human pregnancy remain to be examined.
MyD88 plays a key role in LPS-induced Stat3 activation in the hypothalamus
Authors: Yamawaki Yosuke , Kimura Hitomi , Hosoi Toru , Ozawa Koichiro
Published: December 2009

Infection causes the production of proinflammatory cytokines, which act on the central nervous system (CNS) and can result in fever, sleep disorders, depression-like behavior, and even anorexia, although precisely how cytokines regulate the functions of the CNS remain unclear. In the present study, we investigated the regulatory-molecular mechanisms by which cytokines affect hypothalamic function in a state of infection. The intraperitoneal administration of lipopolysaccharide (LPS), a ligand of Toll-like receptor 4 (TLR4), time-dependently (2–24 h) increased signal transducer and activator of transcription 3 (STAT3) phosphorylation in the hypothalamus and liver, which corresponded with anorexia observed within 24 h. Interestingly, the pattern of phosphorylation in response to LPS differed between the hypothalamus and liver. In the hypothalamus, LPS increased STAT3 phosphorylation from 2 h, with a peak at 4 h and a decline thereafter, whereas, in the liver, the peak activation of STAT3 persisted from 2 to 8 h. The time course of the LPS-induced expression of suppressor of cytokine signaling 3 (SOCS3), a STAT3-induced negative regulator of the Janus kinase-STAT pathway, was similar to that of STAT3 phosphorylation. Using mice deficient in myeloid differentiation primary-response protein 88 (MyD88), an adapter protein of TLR4, we found that LPS-induced STAT3 phosphorylation and SOCS3 expression in the hypothalamus and liver were predominantly mediated through MyD88. Moreover, we observed that MyD88-deficient mice were resistant to LPS-induced anorexia. Taken together, our findings reveal a novel mechanism, i.e., MyD88 plays a key role in mediating STAT3 phosphorylation and anorexia in the CNS in a state of infection and inflammation.
Translational medicine: the antihypertensive effect of renal denervation
Authors: DiBona Gerald F. , Esler Murray
Published: December 2009

Translational medicine is concerned with the translation of research discoveries into clinical applications for the prevention, diagnosis, and treatment of human diseases. Here we briefly review the research concerning the role of the renal sympathetic nerves (efferent and afferent) in the control of renal function, with particular reference to hypertension. The accumulated evidence is compelling for a primary role of the renal innervation in the pathogenesis of hypertension. These research discoveries led to the development of a catheter-based procedure for renal denervation in human subjects. A proof-of-principle study in patients with hypertension resistant to conventional therapy has demonstrated that the procedure is safe and produces renal denervation with sustained lowering of arterial pressure.
Single photon emission-computed tomography (SPECT) for functional investigation of the proximal tubule in conscious mice
Authors: Jouret François , Walrand Stéphan , Parreira Kleber S. , Courtoy Pierre J. , Pauwels Stanislas , Devuyst Olivier , Jamar François
Published: December 2009

Noninvasive analysis of renal function in conscious mice is necessary to optimize the use of mouse models. In this study, we evaluated whether single photon emission-computed tomography (SPECT) using specific radionuclear tracers can be used to analyze changes in renal proximal tubule functions. The tracers included 99mTC- dimercaptosuccinic acid (99mTc-DMSA), which is used for cortex imaging; 99mTc-mercaptoacetyltriglycine (99mTc-MAG3), used for dynamic renography; and 123I-β2-microglobulin, which monitors receptor-mediated endocytosis. 99mTc-DMSA SPECT imaging was shown to delineate the functional renal cortex with a ∼1-mm spatial resolution and accumulated in the cortex reaching a plateau 5 h after injection. The cortical uptake of 99mTc-DMSA was abolished in Clcn5 knockout mice, a model of proximal tubule dysfunction. Dynamic renography with 99mTc-MAG3 in conscious mice demonstrated rapid extraction from blood, renal accumulation, and subsequent tubular secretion. Anesthesia induced a significant delay in the 99mTc-MAG3 clearance. The tubular reabsorption of 123I-β2-microglobulin was strongly impaired in the Clcn5 knockout mice, with defective tubular processing and loss of the native tracer in urine, reflecting proximal tubule dysfunction. Longitudinal studies in a model of cisplatin-induced acute tubular injury revealed a correlation between tubular recovery and 123I-β2-microglobulin uptake. These data show that SPECT imaging with well-validated radiotracers allows in vivo investigations of specific proximal tubule functions in conscious mice.
Conditionally immortalized human podocyte cell lines established from urine
Authors: Sakairi Toru , Abe Yoshifusa , Kajiyama Hiroshi , Bartlett Linda D. , Howard Lilian V. , Jat Parmijit S. , Kopp Jeffrey B.
Published: December 2009

Evidence suggests that loss of podocytes into urine contributes to development of glomerular diseases; shed podocytes are frequently viable and proliferate in culture conditions. To determine the phenotypic characteristics of viable urinary cells derived from human subjects, we established long-term urinary cell culture from two patients with focal segmental glomerulosclerosis and two healthy volunteers, via transformation with the thermosensitive SV40 large T antigen (U19tsA58) together with human telomerase (hTERT). Characterization of arbitrarily selected two clonal cell lines from each human subject was carried out. mRNA expression for the podocyte markers synaptopodin, nestin, and CD2AP were detected in all eight clones. Podocin mRNA was absent from all eight clones. The expression of nephrin, Wilms' tumor 1 (WT1), and podocalyxin mRNA varied among the clones, which may be due to transformation and/or cloning. These results suggest that podocyte cell lines can be established consistently from human urine. The generation of podocyte cell lines from urine of patients and healthy volunteers is novel and will help to advance studies of podocyte cell biology. Further improvements in the approaches to cell transformation and/or cell culture techniques are needed to allow cultured podocytes to fully reproduce in vivo characteristics.
Effect of the Stimulation of Sensory Inputs on the Firing of Neurons of the Trigeminal Main Sensory Nucleus in the Rat
Authors: Bernier A. P. , Arsenault I. , Lund J. P. , Kolta A.
Published: December 2009

Mastication can be triggered by repetitive stimulation of the cortex or of sensory inputs, but is patterned by a brain stem central pattern generator (CPG). This CPG may include the dorsal part of the principal trigeminal sensory nucleus (NVsnpr), where neurons burst repetitively when the extracellular concentration of Ca2+ ([Ca2+]e) drops. We examined the effects of repetitive stimulation of sensory afferents of the trigeminal tract on activity of NVsnpr neurons recorded extracellularly in vitro under physiologic [Ca2+]e (1.6 mM). Spontaneously active cells had either a tonic ( n = 145) or a bursting ( n = 46) firing pattern. Afferent stimulation altered burst duration and/or burst frequency in bursting cells and firing frequency in most tonic cells. In 28% of the latter, the firing pattern switched to rhythmic bursting. This effect could be mimicked by local application of N-methyl-d-aspartate and blocked by APV but not DNQX. Detailed analysis showed that rhythm indices (RIs) of 35 tonic neurons that were negative (nonrhythmic) before stimulation became significantly rhythmic (RI ≥ 0.01) after stimulation. Mean and median bursting frequency of these units were 8.32 ± 0.72 (SE) Hz and 6.25 Hz (range, 2.5–17.5 Hz). In seven instances, two units were recorded simultaneously, and cross-correlation analysis showed that firing of six pairs was rhythmic and synchronized after stimulation. Optimal stimulation parameters for eliciting rhythmic bursting consisted in 500-ms trains of pulses delivered at 40–60 Hz. Together, our results show that repetitive stimulation of sensory afferents in vitro can elicit masticatory-like rhythmic bursting in NVsnpr neurons at physiological [Ca2+]e.
Genomic analysis distinguishes phases of early development of the mouse atrio-ventricular canal
Authors: Vrljicak Pavle , Chang Alex C. Y. , Morozova Olena , Wederell Elizabeth D. , Niessen Kyle , Marra Marco A. , Karsan Aly , Hoodless Pamela A.
Published: December 2009

Valve formation during embryonic heart development involves a complex interplay of regional specification, cell transformations, and remodeling events. While many studies have addressed the role of specific genes during this process, a global understanding of the genetic basis for the regional specification and development of the heart valves is incomplete. We have undertaken genome-wide transcriptional profiling of the developing heart valves in the mouse. Four Serial Analysis of Gene Expression libraries were generated and analyzed from the mouse atrio-ventricular canal (AVC) at embryonic days 9.5–12.5, covering the stages from initiation of endothelial to mesenchymal transition (EMT) through to the beginning of endocardial cushion remodeling. We identified 14 distinct temporal patterns of gene expression during AVC development. These were associated with specific functions and signaling pathway members. We defined the temporal distribution of mesenchyme genes during the EMT process and of specific Notch and transforming growth factor-β targets. This work provides the first comprehensive temporal dataset during the formation of heart valves. These results identify molecular signatures that distinguish different phases of early heart valve formation allowing gene expression and function to be further investigated.