bluuebunny/crossref_metadata_2025 huggingface dataset:
A randomised crossover placebo-controlled trial investigating the effect of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) on postchallenge plasma glucose and insulin levels in men and women
Authors: Paradis Marie-Eve , Couture Patrick , Lamarche Benoît
Published: December 2011

This study examined the impact of brown seaweed on post-load plasma glucose and insulin concentrations in men and women. Twenty-three participants (11 men, 12 women) aged 19–59 years were recruited in this double-blind, randomized, placebo-controlled crossover study. The test product consisted of a commercially available blend of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) with known inhibitory action on α-amylase and α-glucosidase activities (InSea2). Two 250 mg seaweed capsules and 2 placebo capsules were consumed on each occasion 30 min prior to the consumption of 50 g of carbohydrates from bread. Plasma glucose and insulin concentrations were measured over a period of 3 h postcarbohydrate ingestion at predetermined time points. Both treatments were separated by a 1-week washout period. Data were analysed using mixed models for repeated measures. Compared with placebo, consumption of seaweed was associated with a 12.1% reduction in the insulin incremental area under the curve (p = 0.04, adjusted for baseline) and a 7.9% increase in the Cederholm index of insulin sensitivity (p < 0.05). The single ingestion of 500 mg of brown seaweed had no significant effect on the glucose response (p = 0.24, adjusted for baseline). Glucose and insulin responses were similar between men and women. Consumption of the seaweed capsules was not associated with any adverse event. These data suggest that brown seaweed may alter the insulin homeostasis in response to carbohydrate ingestion.
Energy intake and appetite-related hormones following acute aerobic and resistance exercise
Authors: Balaguera-Cortes Liliana , Wallman Karen E. , Fairchild Timothy J. , Guelfi Kym J.
Published: December 2011

Previous research has shown that resistance and aerobic exercise have differing effects on perceived hunger and circulating levels of appetite-related hormones. However, the effect of resistance and aerobic exercise on actual energy intake has never been compared. This study investigated the effect of an acute bout of resistance exercise, compared with aerobic exercise, on subsequent energy intake and appetite-regulating hormones. Ten active men completed 3 trials in a counterbalanced design: 45 min of resistance exercise (RES; free and machine weights), aerobic exercise (AER; running), or a resting control trial (CON). Following exercise or CON, participants had access to a buffet-style array of breakfast foods and drinks to consume ad libitum. Plasma concentrations of a range of appetite-regulating hormones were measured throughout each trial. Despite significantly higher energy expenditure with AER compared with RES (p < 0.05), there was no difference in total energy intake from the postexercise meal between trials (p = 0.779). Pancreatic polypeptide was significantly higher prior to the meal after both RES and AER compared with CON. In contrast, active ghrelin was lower following RES compared with both CON and AER (p ≤ 0.05), while insulin was higher following RES compared with CON (p = 0.013). In summary, the differential response of appetite-regulating hormones to AER and RES does not appear to influence energy intake in the postexercise meal. However, given the greater energy expenditure associated with AER compared with RES, AER modes of exercise may be preferable for achieving short-term negative energy balance.
Tunneling beneath driven or jacked end-bearing piles in sand
Authors: Marshall Alec M. , Mair Robert J.
Published: December 2011

This paper presents centrifuge model test data that relate to the problem of tunneling beneath driven or jacked end-bearing piles in sand. The centrifuge model consisted of a tunnel and two piles and allowed for the acquisition of subsurface digital images throughout the tests. Soil and pile displacements were measured using particle image velocimetry and close-range photogrammetry techniques. The piles were jacked into the ground in-flight prior to tunnel volume loss to obtain ground stress profiles representative of conditions around driven or jacked piles. Patterns of displacements and calculated soil strains are presented to illustrate mechanisms of displacement and soil behavior. The measured soil and pile displacements are compared against greenfield test measurements. The results indicate that driving the piles significantly alters greenfield conditions and that greenfield displacements should not be used as an input for analytical tunnel–soil–pile interaction analyses for driven or jacked piles. Large pile displacements were observed to occur suddenly in the tests, illustrating the brittle nature of the soil in the areas affected by pile installation. A relationship between relative pile–tunnel location and the volume loss at which large pile displacements occurred is presented, which provides useful guidance to tunnel design engineers.
A new interparticle friction apparatus for granular materials
Authors: Cavarretta I. , Rocchi I. , Coop M.R.
Published: December 2011

A new apparatus is described that measures interparticle friction between sand-sized grains over relatively large displacements and also under immersion in a fluid. Its relatively simple design allows the key calibrations to be checked by statics. An analysis of the geometry of simple spherical particle contacts and the forces at those contacts revealed that there are strict constraints on the permissible stiffness of the interparticle friction apparatus to avoid stick–slip behaviour. Tests on ball bearings gave highly repeatable data, while others on glass ballotini revealed a significant effect of ambient humidity on the data obtained. The interparticle friction was found to increase with the roughness of the ballotini. Immersion in water increased the interparticle friction slightly for both the ballotini and quartz sand particles, while immersion in oil reduced the friction considerably for the quartz sand, especially at higher contact force levels.
LOGICAL CHARACTERIZATION OF RECOGNIZABLE SETS OF POLYNOMIALS OVER A FINITE FIELD
Authors: RIGO MICHEL , WAXWEILER LAURENT
Published: December 2011

The ring of integers and the ring of polynomials over a finite field share a lot of properties. Using a bounded number of polynomial coefficients, any polynomial can be decomposed as a linear combination of powers of a non-constant polynomial P playing the role of the base of the numeration. Having in mind the theorem of Cobham from 1969 about recognizable sets of integers, it is natural to study P-recognizable sets of polynomials. Based on the results obtained in the Ph.D. thesis of the second author, we study the logical characterization of such sets and related properties like decidability of the corresponding first-order theory.
EFFECT OF NITROGEN VARIATION ON THE SYNTHESIS OF VERTICALLY ALIGNED BAMBOO-SHAPED C–N NANOTUBES USING SUNFLOWER OIL
Authors: KUMAR RAJESH , YADAV RAM MANOHAR , AWASTHI KALPANA , TIWARI R. S. , SRIVASTAVA O. N.
Published: December 2011

To examine the role of NH3 on bundles of aligned bamboo-shaped carbon–nitrogen (C–N) nanotube were synthesized the pyrolysis of ferrocene (Fe(C5H5)2) and sunflower oil mixtures with NH3 being the source of nitrogen. The concentration of NH3 was varying in volume (vol). Optimized temperature and concentration of ferrocene were 825°C and 10 mg/ml, respectively. With the increase of nitrogen concentration the bundles are breaking in nearly equal parts. With nitrogen doping, the nanotubes have a bamboo-like structure and reveal degraded crystallinity of graphitic sheets. Nitrogen plays key role in generating equal compartments inside the carbon nanotube. The nanotubes were characterized by scanning electron microscopy and transmission electron microscopy that reveal the vertically aligned and hollow structural features of the nanotubes. FTIR shows the incorporation of N atom inside carbon framework and Raman spectrum indicates the enhancement of the defects inside C–N nanotube due to the N atom in C–N nanotube.
ZnO-NANOCRYSTALS IN STRONG CONFINEMENT REGIMES: INSIGHT ON RELAXATION DYNAMICS OF DEFECT STATES RESPONSIBLE FOR THE VISIBLE LUMINESCENCE
Authors: LAYEK ARUNASISH , CHOWDHURY ARINDAM
Published: December 2011

The broad visible photoluminescence (PL) observed in ZnO nanocrystals (NCs) is widely attributed to multiple low lying surface-defects. We have performed steady state and time-resolved PL measurements on size-selected ZnO NCs in the strong confinement regimes. Our results show that radiative relaxation rates and coupling between excitons and surface defect states vary dramatically for sizes between 2 nm and 3 nm. Energy dependent PL lifetimes reveal that relaxation dynamics of these defect states in the blue- and red-edge of the emission are very different from each other.
STRUCTURAL AND ELECTRICAL PROPERTIES OF RF MAGNETRON SPUTTERED TANTALUM OXIDE FILMS
Authors: CHANDRA S. V. JAGADEESH , PARK D. S. , UTHANNA S. , CHOI CHEL-JONG , REDDY A. GURUVA
Published: December 2011

RF magnetron sputtering technique was employed for deposition of tantalum oxide films on p-type silicon substrates by sputtering of pure tantalum oxide target in the presence of oxygen and argon gases at a temperature of 303 K. X-ray photoelectron spectroscopic and X-ray diffraction studies indicated that the films annealed at 773 K were stoichiometric and polycrystalline respectively. The accumulation capacitance for the devices in a structure of Al/Ta2O5/p-Si has been decreased noticeably lower values for the devices annealed at high temperatures. Improved current–voltage characteristics were observed for all annealed devices with Poole–Frenkel conduction mechanism.
pH-DEPENDENT SYNTHESIS OF STABILIZED GOLD NANOPARTICLES USING ASCORBIC ACID
Authors: TYAGI HIMANSHU , KUSHWAHA AJAY , KUMAR ANSHUMAN , ASLAM M.
Published: December 2011

The stabilization of gold nanoparticles solution synthesized using ascorbic acid at room temperature is examined in detail. It is found that gold nanoparticles (AuNPs) synthesized using ascorbic acid have a narrow size distribution (31 ± 5, 36 ± 6, and 40 ± 5 nm) and can be readily stabilized just by adjusting the initial pH conditions of the reaction solutions. Whilst the initial pH strongly affects the stability of particles, it has no effect on the size of stabilized particles. The particles are nearly spherical having size distribution effectively in the range of 30 nm to 40 nm. Through time dependent UV-Vis spectra studies we also hypothesize the pH dependent stabilization mechanism wherein a layer of adsorbed ionic complex over AuNPs slows down the aggregation of AuNPs . The information obtained in this study can be used to design in-situ controlled nanoparticle synthesis system especially within the biological cells. Moreover, the method is green and biologically acceptable as well.
Chapter 10 Modelling the Snowball Earth
Authors: Goddéris Yves , Le Hir Guillaume , Donnadieu Yannick
Published: December 2011

We review most of the modelling studies performed to date to understand the initiation and melting of a Snowball Earth, as well as to describe the glacial environment during the glaciation itself. All the described scenarios explaining the onset of glaciation rely on a sufficient decrease in the concentrations of atmospheric greenhouse gases (GHGs), typically resulting from the equatorial palaeogeography of the late Proterozoic. It is still heavily debated whether or not the oceanic ice cover was thick during the glaciation itself. However, a consensus has arisen that the most climatically stable scenarios imply the existence of a globally frozen ocean, with a thick ice cover caused by the flowing of high-latitude sea-ice glaciers towards the equator. Depending on the characteristics of the ice, a thin ice layer may have persisted along the equator, but this numerical solution is rather fragile. During the snowball event itself, model results suggest the existence of wet-based continental glaciers. Some parts of the continents may have remained ice-free. From the modelling perspective, the most significant problem in the snowball hypothesis, particularly in its ‘hard snowball’ version (the most stable numerically), is the melting phase. With improved modelling, the CO
2
threshold required to melt the snowball is much higher than initially thought, significantly above 0.29 bar. Indeed, because of the very cold conditions prevailing at the surface of the Earth during the glacial event, the atmosphere becomes vertically isothermal, strongly limiting the efficiency of the greenhouse effect. This melting problem is further highlighted by geochemical modelling studies that show that weathering of the oceanic crust might be an active sink of CO
2
during the glacial event, limiting the rise in atmospheric CO
2
. The solution might be found by considering the input of dark dust from catastrophic volcanic eruptions that would efficiently decrease the albedo of the ice. Finally, modelling studies also explore the aftermath of the glaciation. The world might have been drier than initially anticipated, resulting in the persistence of the supergreenhouse effect for at least one million years after the melting phase.
Chapter 18 The Karoetjes Kop and Bloupoort formations, Gifberg Group, South Africa
Authors: Frimmel Hartwig E.
Published: December 2011

The Vredendal Outlier near the South African west coast lies in an intermediate position between the late Neoproterozoic Gariep Belt further north and the Cambrian Saldania Belt further south. It consists of a sedimentary succession of siliciclastic and carbonate rocks, unified as the Gifberg Group, which contains two diamictite-bearing units, the Karoetjes Kop Formation at the base and the Bloupoort Formation near the top of the group. The diamictite of the Karoetjes Kop Formation represents mainly debris flow deposits in a continental rift setting, with some contribution from retreating glaciers. In contrast, the younger diamticite in the Bloupoort Formation is glaciomarine, is associated with banded iron-formation, is underlain by stromatolitic reef carbonates and is overlain by carbonates. Most of the Gifberg Group is poorly exposed and poorly investigated. In the absence of radiometric age data, stratigraphic interpretation and correlation is based on lithological and chemostratigraphic evidence. The entire Gifberg Group is considered to be equivalent to the much better investigated Port Nolloth Group in the Gariep Belt (
sensu stricto
). Whereas the Karoetjes Kop Formation is correlated with the
c.
750 Ma Kaigas Formation of the Gariep Belt, the diamictite and associated banded iron-formation of the Bloupoort Formation are regarded as correlatives of the Numees Formation of the Gariep Belt. The entire Gifberg Group was subjected to transpressional deformation and accompanying low-grade metamorphism during continental collision between the Rio de la Plata and Kalahari plates at the end of the Neoproterozoic and again during the Cambrian accretionary orogeny along the southwestern margin of Gondwana, which led to the development of the Saldania Belt further south.
Chapter 34 The Hula Hula Diamictite and Katakturuk Dolomite, Arctic Alaska
Authors: Macdonald Francis A.
Published: December 2011

The Katakturuk Dolomite is a
c.
2-km-thick Neoproterozoic carbonate succession (units K1–K4) exposed in the NE Brooks Range of Alaska. These strata were deposited on a south-facing (present coordinates), rifted passive margin on the North Slope subterrane (NSST) of the Arctic Alaska-Chukotka Plate (AACP). The glaciogenic Hula Hula diamictite rests below the Katakturuk Dolomite and consists of 2–50 m of diamictite that interfingers with the underlying Mt. Copleston volcanic rocks. Unit K1 of the Katakturuk Dolomite begins with less than 10 m of dark grey, finely laminated limestone with ‘roll-up’ structures, and continues upwards with nearly 500 m of recrystallized, ooid-dominated grainstone. The Nularvik dolomite (unit K2 of the Kataktruk Dolomite) rests on unit K1 with a knife-sharp contact on a heavily silicified surface. The Nularvik dolomite is composed predominantly of laminated micro-peloids hosting tubestone stromatolites and giant wave ripples, followed by decametres of dolomatized, pseudomorphosed former aragonite crystal fans.

Carbon-isotope chemostratigraphy suggests that the Hula Hula diamictite is an early Cryogenian glacial deposit, and that, despite the absence of directly underlying glacial deposits, the Nularvik dolomite is a basal Ediacaran cap carbonate. These correlations are supported by the characteristic sedimentological features in both the carbonate capping the Hula Hula diamictite and the Nularvik dolomite. Detrital zircon and Palaeozoic fauna provenance studies support the inference that much of the AACP is exotic to Laurentia; however, the pre-Mississipian relationship between the NSST and the rest of the AACP remains uncertain. Previous palaeomagnetic surveys have been hampered by pervasive Late Cretaceous overprints. Additional geological mapping, sequence stratigraphy and geochronological data are needed to correlate Neoproterozoic and Palaeozoic units across the AACP, and constrain relationships between subterranes in the AACP.
Chapter 35 The Tatonduk inlier, Alaska–Yukon border
Authors: Macdonald Francis A. , Cohen Phoebe A.
Published: December 2011

Glaciogenic deposits of the Rapitan and Hay Creek Groups are exposed in the Tatonduk inlier of east-central Alaska and the western Yukon. The Rapitan Group ranges in thickness from
c.
50 to 700 m with Fe-formation common in the upper 10 m. In the most distal settings, the Rapitan Group is separated from the diamictite of the Hay Creek Group by over 100 m of sandstone and siltstone; however, the Hay Creek Group contains large erosive surfaces and cannibalizing breccia, and rarely preserves strata between the two glaciogenic deposits. The diamictite of the Hay Creek Group is capped by a white- to buff-coloured dolostone with pseudo-teepee structures, bed-parallel, isopachous sheet-crack cements, and a depleted C-isotope signature. Late Neoproterozoic glacial deposits in the Tatonduk inlier were formerly assigned to the Tindir Group. To simplify the nomenclature in the northwestern Canadian Cordillera, the Tindir Group was abandoned and replaced with nomenclature consistent with that of the Windermere Supergroup in the Mackenzie Mountains. The mixed lithology and anchizone-grade metamorphism distinguish the Rapitan and Hay Creek Groups in the Tatonduk inlier as attractive future targets for integrated micropalaeontology, geochemistry, palaeomagnetism and geochronology.
Chapter 37 The record of Neoproterozoic glaciations in the Windermere Supergroup, southern Canadian Cordillera
Authors: Smith Mark D. , Arnaud Emmanuelle , Arnott R.W.C. , Ross Gerald M.
Published: December 2011

The Neoproterozoic Windermere Supergroup (WSG) is exposed over an area of 35 000 km
2
in the southern Canadian Cordillera, and consists primarily of deep-marine meta-sedimentary rocks interpreted to have been deposited during rifting and subsequent post-rift thermal relaxation. The main exposures of the WSG occur within thrust panels and structural culminations of the eastern Cordilleran orogen. Within the thick stratigraphic succession (
c.
9 km) are three units of glaciogenic affinity: Toby, Vreeland and Old Fort Point (OFP) formations. The Toby Formation (Fm.) is composed of up to 2500 m of diamictite, interbedded with conglomerate, sandstone, mudstone, carbonate and mafic volcanic rocks. The Vreeland Formation ranges from 350 m to 2000 m in thickness and consists of diamictite, interbedded with mudstone, sandstone and conglomerate. The OFP ranges from 60 to 450 m in thickness and consists of a distinctive threefold stratigraphic package of basal siltstone grading upward into limestone–siltstone rhythmite, organic-rich mudstone and an overlying heterolithic unit of diamictite, breccia, conglomerate, sandstone, siltstone to mudstone and limestone. A locally prominent unconformity marks the base of the OFP upper member. Both the Toby and Vreeland formations represent remobilized glacially derived marine sediments deposited by sediment-gravity flows. Deposition of the Toby Fm. was fault-controlled during an active tectonic phase (rifting), whereas the Vreeland Fm. accumulated during the subsequent quiescent phase (post-rift) with limited structural control. The OFP is interpreted to be a regionally extensive deep-marine post-glacial marker temporally associated with the glaciogenic Vreeland Fm. Although direct geochronological ages for WSG units in southwestern Canada are generally absent, high-precision radiometric ages of underlying and overlying igneous events constrain the relative maximum and minimum timing of deposition from
c.
740–728 Ma to
c.
569 Ma. At the base of the WSG succession, the Toby Fm. may be as young as
c.
685 Ma based on ages obtained from potential stratigraphic correlatives in the USA. There is no direct age constraint for the deposition of the Vreeland Fm.; its minimum timing is based on its stratigraphic relationship with the post-glacial OFP. The middle member of the OFP was precisely dated at 607.8±4.7 Ma using the Re–Os method, placing it in the Ediacaran Period. Published geochemical and stable isotopic data are similarly limited for all three units with only some δ
34
S
py
values available from one section of the OFP. Recent work has focused on detailed sedimentological and stratigraphic studies of the Toby and OFP formations with future efforts being directed towards integrated geochemical and isotopic research. Additional geochronological constraints are needed to refine palaeogeographical models and strengthen regional correlations with other North American Cordilleran glaciogenic units.
Chapter 41 Glaciogenic and related strata of the Neoproterozoic Kingston Peak Formation in the Panamint Range, Death Valley region, California
Authors: Petterson Ryan , Prave Anthony R. , Wernicke Brian P.
Published: December 2011

Glaciogenic deposits in the Death Valley region occur within the Neoproterozoic Kingston Peak Formation (Fm.). In the Panamint Range, immediately west of Death Valley, the formation is as much as 1000 m thick and is continuously exposed for nearly 100 km along the strike of the range. Although the strata are variably metamorphosed and locally exhibit pronounced ductile strain, original sedimentary textures are well preserved in many places. Diamictite occurs in two distinct intervals, a lower one comprising the Limekiln Spring and Surprise members, and an upper one, the Wildrose Sub-member of the South Park Member. Lonestones, bullet-shaped and striated clasts, and rare dropstones within these members, along with the impressive lateral continuity of diamictic units, support a glacial origin. Both diamictic intervals are succeeded by well-defined carbonates, the oldest is the Sourdough Member of the Kingston Peak Fm. and the younger one is the Sentinel Peak Member of the overlying Noonday Dolomite. The stratigraphic succession between the Sourdough Member and the Wildrose Sub-member (i.e. the Middle Park, Mountain Girl and Thorndike sub-members of the South Park Member) is
c.
300 m thick and includes lithologies recording deposition in braided fluvial to platform carbonate settings. Lithostratigraphic and chemostratigraphic profiles of δ
13
C for the Sourdough (–3‰ to +2‰, increasing upward) and Sentinel Peak (–3‰ ±1‰) members suggest correlation with, respectively, the older Cryogenian (commonly referred to as ‘Sturtian’ in previous literature) and younger Cryogenian (commonly referred to as ‘Marinoan’ in previous literature) cap-carbonate sequences recognized worldwide. Potentially economic uranium deposits (secondary brannerite) occur in graphitic schist of the Limekiln Spring Member and sub-economic uranium and thorium (hosted by detrital monazite) occur within quartz-pebble conglomerate in the South Park Member. The Kingston Peak Fm. strata in the Panamint Range contain no fossils, radiometric age control or primary magnetizations.
Chapter 44 The Chiquerío Formation, southern Peru
Authors: Chew David , Kirkland Christopher
Published: December 2011

The Chiquerío Formation (Fm.) is a thick glaciogenic succession deposited unconformably on gneisses of the Arequipa massif in southern Peru. It has undergone greenschist facies metamorphism during Early Palaeozoic orogenesis. The Chiquerío Fm. consists of nearly 400 m of diamictite, sandstone, mudstone and carbonate, with a thin (11 m) cap dolostone at the top of the formation. It is overlain by the San Juan Fm., a 2-km-thick carbonate succession. The thick glacially influenced succession was deposited in deep marine conditions and consists mainly of massive diamictites (representing either ice-rafted debris or submarine debris flows) interbedded with turbiditic sandstones. Where internal lamination is present (e.g. bedding in the turbiditic packages), abundant dropstones can be recognized. There is no evidence of shallow marine reworking of the succession. No absolute age constraints on the depositional timing of the Chiquerío Fm. exist, because no volcanic tuffs have yet been identified. U–Pb dating of detrital zircons (U–Th–Pb SIMS) from the Chiquerío Fm. and the overlying San Juan Fm. suggest it is autochthonous with respect to Amazonia, as the detrital zircon age spectra suggest derivation from the Amazonian craton. Detrital grains as young as
c.
700 Ma have been documented in the post-glacial San Juan Fm. The sparse (chemo)stratigraphic data available for the Chiquerío Fm. exhibit patterns similar to those observed generally in Neoproterozoic post-glacial carbonate sequences. Palaeogeographic models for the deposition of the Chiquerío Fm. are critically dependent on the timing of the docking of the basement of the Arequipa massif with the South American craton (Amazonia). Presently there are no palaeomagnetic constraints. More research on the chronological and palaeogeographical constraints of this succession is required.

Supplementary material:
Data are available at
http://www.geolsoc.org.uk/SUP18479
.
Chapter 5 Chemical sediments associated with Neoproterozoic glaciation: iron formation, cap carbonate, barite and phosphorite
Authors: Hoffman Paul F. , Macdonald Francis A. , Halverson Galen P.
Published: December 2011

Orthochemical sediments associated with Neoproterozoic glaciation have prominence beyond their volumetric proportions because of the insights they provide on the nature of glaciation and the records they hold of the environment in which they were precipitated. Synglacial Fe formations are mineralogically simple (haematite jaspilite), and their trace element spectra resemble modern seawater, with a weaker hydrothermal signature than Archaean–Palaeoproterozoic Fe formations. Lithofacies associations implicate subglacial meltwater plumes as the agents of Fe(II) oxidation, and temporal oscillations in the plume flux as the cause of alternating Fe- and Mn-oxide deposits. Most if not all Neoproterozoic examples belong to the older Cryogenian (Sturtian) glaciation. Older and younger Cryogenian (Marinoan) cap carbonates are distinct. Only the younger have well-developed transgressive cap dolostones, which were laid down during the rise in global mean sea level resulting from ice-sheet meltdown. Marinoan cap dolostones have a suite of unusual sedimentary structures, indicating abnormal palaeoenvironmental conditions during their deposition. Assuming the meltdown of ice-sheets was rapid, cap dolostones were deposited from surface waters dominated by buoyant glacial meltwater, within and beneath which microbial activity probably catalysed dolomite nucleation. Former aragonite seafloor cement (crystal fans) found in deeper water limestone above Marinoan cap dolostones indicates carbonate oversaturation at depth, implying extreme concentrations of dissolved inorganic carbon. Barite is associated with a number of Marinoan cap dolostones, either as digitate seafloor cement associated with Fe-dolomite at the top of the cap dolostone, or as early diagenetic void-filling cement associated with tepee or tepee-like breccias. Seafloor barite marks a redoxcline in the water column across which euxinic Ba-rich waters upwelled, causing simultaneous barite titration and Fe(III) reduction. Phosphatic stromatolites, shrub-like structures and coated grains are associated with a glacioisostatically induced exposure surface on a cap dolostone in the NE of the West African craton, but this appears to be a singular occurrence of phosphorite formed during a Neoproterozoic deglaciation.
Chapter 55 Glacial sediments and associated strata of the Polarisbreen Group, northeastern Svalbard
Authors: Halverson Galen P.
Published: December 2011

Northeastern Svalbard hosts exceptionally well-preserved Neoproterozoic sediments. The glaciogenic Petrovbreen Member and Wilsonbreen Formation (Fm.) of the Polarisbreen Group crop out in a narrow, Caledonian-aged fold-and-thrust belt spanning from Olav V Land on Spitsbergen in the south to western Nordaustlandet in the north. The older Petrovbreen Member is thin (0–52 m) and patchily preserved, comprising mainly poorly stratified, dolomite-matrix diamictite likely deposited in a marine setting. The basal contact of the Petrovbreen Member erosionally truncates the upper Russøya Member, which preserves a large (12‰) negative C-isotope anomaly. The Petrovbreen Member is overlain by 200 m of dark, monotonous shales of the MacDonaldryggen Member, followed by cherty dolomite grainstone and microbiolamintes of the Slangen Member. The upper Slangen Member is an exposure surface in the southern part of the belt, but in northern Spitsbergen and on Nordaustlandet is transitional into sands of the northward-thickening Bråvika Member. The Wilsonbreen Fm. is typically 100–150 m thick and consists mostly of massively to poorly stratified diamictite, with subordinate sand beds, conglomerate lenses, and carbonates deposited in a terrestrial environment. It is overlain by the colourful Dracoisen Fm., which records, at its base, a typical post-glacial negative δ
13
C anomaly. There are no direct radiometric age constraints or reliable palaeomagnetic data from the Polarisbreen Group, but it is widely accepted that northeastern Svalbard was contiguous with East Greenland during the Neoproterozoic.
Chapter 59 Neoproterozoic glaciation of South Norway: from continental interior to rift and pericratonic basins in western Baltica
Authors: Nystuen Johan P. , Lamminen Jarkko T.
Published: December 2011

Neoproterozoic glacial deposits of South Norway comprise the Moelv and Koppang formations. The former occurs on Baltican crystalline basement in autochthonous position at the Caledonian erosional nappe front, on basement windows and basement thrust sheets in the Caledonian nappe region, and in thick sedimentary successions in the allochthonous Hedmark and Valdres rift basins. The Koppang Formation (Fm.) occurs on top of platform carbonates in the allochthonous pericratonic Engerdalen Basin. The glacial deposits are dominated by diamictite interpreted as basal till from warm-based grounded ice, whereas stratified successions of diamictite beds, sandstone and laminated siltstone with outsized stones represent local ice-margin deposits and/or subglacially infilled water bodies, and the final glaciomarine stage. Palinspastic reconstruction of Caledonian nappe complexes carrying the glacial formations indicates that the glacial deposits were deposited over a wide area by a large western Baltoscandian ice sheet, probably during the Gaskiers (
c.
580 Ma) glacial event (or events), but the age of the glaciation in South Norway needs to be better constrained.
Chapter 60 Evidence for late Neoproterozoic glaciation in the central Scandinavian Caledonides
Authors: Kumpulainen Risto A. , Greiling Reinhard O.
Published: December 2011

The Långmarkberg Formation (Fm). rests on either the Neoproterozoic rift-related Risbäck Group or Palaeoproterozoic basement in central Scandinavia. It is always succeeded in stratigraphy by the marine Gärdsjön Fm. The Långmarkberg Fm. is a thin, generally less than 50-m-thick, discontinuous, but persistent unit, primarily in the Lower Allochthon; subordinately also in the Autochthon, and Middle Allochthon of the central Scandinavian Caledonides. The formation is composed of a lower diamictite and an upper laminated, lonestone-bearing mudstone.

Criteria supporting the glaciogenic origin of the formation are (i) a large regional extension of the formation (>5000 km
2
) and (ii) its fixed position in the regional stratigraphy, (iii) the ‘tillite-like’ appearance of the lower part of the formation, (iv) the lonestone-bearing mudstone in the upper part, (v) the presence of striated clasts and (vi) striated pavement. It is interpreted as having formed during one single glacial–deglacial cycle.

Information on chemostratigraphy and realistic geochronology from this region is missing. The Långmarkberg Fm. has commonly been correlated with the Moelv Fm. in southern Norway and the Mortensnes Fm. in northernmost Norway. The Lower Allochthon in this region also contains an older, potentially glacially influenced diamictite unit at the base of the Risbäck Group, which is also briefly discussed.
Chapter 61 The Neoproterozoic glaciogenic Lillfjället Formation, southern Swedish Caledonides
Authors: Kumpulainen Risto A.
Published: December 2011

The Tossåsfjället Group, which crops out in the Middle Allochthon of the Scandinavian Caledonides, contains the glaciogenic Lillfjället Fm. Evidence that supports the interpretation of the Lillfjället formations as glacially related include the presence of diamictite beds, the presence of lonestones, although few, in laminated units, one possible faceted clast, involution-like deformation structures, and the presence of sandstone wedges cutting 2.5–3 m down into two different diamictite beds. Similar to the other glaciogenic formations in southern and central Scandinavia (Moelv and Långmarkberg formations), the Lillfjället Fm. rests on a unit of peritidal, sabkha-type dolomite of the Storån Fm. Poor exposure contributes to the uncertainty about the thickness of the formation. In this account, the Lillfjället Fm. stratigraphy has been divided into three subunits: (i) a lower diamictite-dominated unit, (ii) a middle unit composed of distinctly laminated grey sandy mudstone and (iii) an upper diamictite-dominated unit. There is no information available from the Tossåsfjället Group concerning palaeolatitudes and chemostratigraphy. Poor isotopic evidence (
40
Ar/
39
Ar) from the Ottfjället Dolerites, which cut the Tossåsfjället Group, indicates that the succession is older than
c.
665 Ma, so a reliable correlation with global glaciation events is not yet possible.
Chapter 8 Biostratigraphy and stratigraphic subdivision of Cryogenian successions of Australia in a global context
Authors: Grey Kathleen , Hill Andrew C. , Calver Clive
Published: December 2011

Cryogenian correlation in Australia is based on an extensive data set from the Centralian Superbasin and Adelaide Rift Complex and integrates biostratigraphy and isotope chemostratigraphy to provide a three-dimensional interpretation based on outcrop and drill holes. Studies are ongoing, but newer data are consistent with the distributions discussed here. From the chemostratigraphic and biostratigraphic viewpoint, the first appearance of the acritarch
Cerebrosphaera buickii
, coupled with a large negative isotope excursion at
c.
800 Ma, supported by the first appearance of the stromatolite
Baicalia burra
, seems to have potential for boundary placement. It is widely recognized across Australia and seems to have potential globally.
Estradiol attenuates high glucose-induced endothelial nitrotyrosine: role for neuronal nitric oxide synthase
Authors: Chakrabarti Subhadeep , Cheung Christopher C. , Davidge Sandra T.
Published: December 2011

Hyperglycemia in diabetes causes increased oxidative stress in the vascular endothelium with generation of free radicals such as superoxide. Peroxynitrite, a highly reactive species generated from superoxide and nitric oxide (NO), induces proinflammatory tyrosine nitration of intracellular proteins under such conditions. The female sex hormone estrogen appears to exert protective effects on the nondiabetic endothelium. However, several studies show reduced vascular protection in women with diabetes, suggesting alterations in estrogen signaling under high glucose. In this study, we examined the endothelial effects of estrogen under increasing glucose levels, focusing on nitrotyrosine and peroxynitrite. Human umbilical vein endothelial cells were incubated with normal (5.5 mM) or high (15.5 or 30.5 mM) glucose before addition of estradiol (E2, 1 or 10 nM). Selective NO synthase (NOS) inhibitors were used to determine the role of specific NOS isoforms. Addition of E2 significantly reduced high glucose-induced increase in peroxynitrite and consequently, nitrotyrosine. The superoxide levels were unchanged, suggesting effects on NO generation. Inhibition of neuronal NOS (nNOS) reduced high glucose-induced nitrotyrosine, demonstrating a critical role for this enzyme. E2 increased nNOS activity under normal glucose while decreasing it under high glucose as determined by its phosphorylation status. These data show that nNOS contributes to endothelial peroxynitrite and subsequent nitrotyrosine generation under high glucose, which can be attenuated by E2 through nNOS inhibition. The altered regulation of nNOS by E2 under high glucose is a potential therapeutic target in women with diabetes.
Effects of KCNQ channel modulators on the M-type potassium current in primate retinal pigment epithelium
Authors: Pattnaik Bikash R. , Hughes Bret A.
Published: December 2011

Recently, we demonstrated the expression of KCNQ1, KCNQ4, and KCNQ5 transcripts in monkey retinal pigment epithelium (RPE) and showed that the M-type current in RPE cells is blocked by the specific KCNQ channel blocker XE991. Using patch-clamp electrophysiology, we investigated the pharmacological sensitivity of the M-type current in isolated monkey RPE cells to elucidate the subunit composition of the channel. Most RPE cells exhibited an M-type current with a voltage for half-maximal activation of approximately −35 mV. The M-type current activation followed a double-exponential time course and was essentially complete within 1 s. The M-type current was inhibited by micromolar concentrations of the nonselective KCNQ channel blockers linopirdine and XE991 but was relatively insensitive to block by 10 μM chromanol 293B or 135 mM tetraethylammonium (TEA), two KCNQ1 channel blockers. The M-type current was activated by 1) 10 μM retigabine, an opener of all KCNQ channels except KCNQ1, 2) 10 μM zinc pyrithione, which augments all KCNQ channels except KCNQ3, and 3) 50 μM N-ethylmaleimide, which activates KCNQ2, KCNQ4, and KCNQ5, but not KCNQ1 or KCNQ3, channels. Application of cAMP, which activates KCNQ1 and KCNQ4 channels, had no significant effect on the M-type current. Finally, diclofenac, which activates KCNQ2/3 and KCNQ4 channels but inhibits KCNQ5 channels, inhibited the M-type current in the majority of RPE cells but activated it in others. The results indicate that the M-type current in monkey RPE is likely mediated by channels encoded by KCNQ4 and KCNQ5 subunits.
Catestatin, a chromogranin A-derived peptide, is sympathoinhibitory and attenuates sympathetic barosensitivity and the chemoreflex in rat CVLM
Authors: Gaede Andrea H. , Pilowsky Paul M.
Published: December 2011

Hypertension is a major cause of morbidity. The neuropeptide catestatin [human chromogranin A-(352–372)] is a peptide product of the vesicular protein chromogranin A. Studies in the periphery and in vitro studies show that catestatin blocks nicotine-stimulated catecholamine release and interacts with β-adrenoceptors and histamine receptors. Catestatin immunoreactivity is present in the rostral ventrolateral medulla (RVLM), a key site for blood pressure control in the brain stem. Recently, we reported that microinjection of catestatin into the RVLM is sympathoexcitatory and increases barosensitivity. Here, we report the effects of microinjection of catestatin (1 mM, 50 nl) into the caudal ventrolateral medulla (CVLM) in urethane-anesthetized, bilaterally vagotomized, artificially ventilated Sprague-Dawley rats ( n = 8). We recorded resting arterial pressure, splanchnic sympathetic nerve activity, phrenic nerve activity, heart rate, and measured cardiovascular homeostatic reflexes. Homeostatic reflexes were evaluated by measuring cardiovascular responses to carotid baroreceptor and peripheral chemoreceptor activation. Catestatin decreased basal levels of arterial pressure (−23 ± 4 mmHg), sympathetic nerve activity (-26.6 ± 5.7%), heart rate (−19 ± 5 bpm), and phrenic nerve amplitude (−16.8 ± 3.3%). Catestatin caused a 15% decrease in phrenic inspiratory period (Ti) and a 16% increase in phrenic expiratory period (Te) but had no net effect on the phrenic interburst interval (Ttot). Catestatin decreased sympathetic barosensitivity by 63.6% and attenuated the peripheral chemoreflex (sympathetic nerve response to brief hypoxia; range decreased 39.9%; slope decreased 30.1%). The results suggest that catestatin plays an important role in central cardiorespiratory control.
Dramatic increase of nitrite levels in hearts of anoxia-exposed crucian carp supporting a role in cardioprotection
Authors: Sandvik Guro K. , Nilsson Göran E. , Jensen Frank B.
Published: December 2011

Nitrite (NO2−) functions as an important nitric oxide (NO) donor under hypoxic conditions. Both nitrite and NO have been found to protect the mammalian heart and other tissues against ischemia (anoxia)-reoxygenation injury by interacting with mitochondrial electron transport complexes and limiting the generation of reactive oxygen species upon reoxygenation. The crucian carp naturally survives extended periods without oxygen in an active state, which has made it a model for studying how evolution has solved the problems of anoxic survival. We investigated the role of nitrite and NO in the anoxia tolerance of this fish by measuring NO metabolites in normoxic, anoxic, and reoxygenated crucian carp. We also cloned and sequenced crucian carp NO synthase variants and quantified their mRNA levels in several tissues in normoxia and anoxia. Despite falling levels of blood plasma nitrite, the crucian carp showed massive increases in nitrite, S-nitrosothiols (SNO), and iron-nitrosyl (FeNO) compounds in anoxic heart tissue. NO2−levels were maintained in anoxic brain, liver, and gill tissues, whereas SNO and FeNO increased in a tissue-specific manner. Reoxygenation reestablished normoxic values. We conclude that NO2−is shifted into the tissues where it acts as NO donor during anoxia, inducing cytoprotection under anoxia/reoxygenation. This can be especially important in the crucian carp heart, which maintains output in anoxia. NO2−is currently tested as a therapeutic drug against reperfusion damage of ischemic hearts, and the present study provides evolutionary precedent for such an approach.
Mechanisms underlying rule learning-induced enhancement of excitatory and inhibitory synaptic transmission
Authors: Saar Drorit , Reuveni Iris , Barkai Edi
Published: December 2011

Training rats to perform rapidly and efficiently in an olfactory discrimination task results in robust enhancement of excitatory and inhibitory synaptic connectivity in the rat piriform cortex, which is maintained for days after training. To explore the mechanisms by which such synaptic enhancement occurs, we recorded spontaneous miniature excitatory and inhibitory synaptic events in identified piriform cortex neurons from odor-trained, pseudo-trained, and naive rats. We show that olfactory discrimination learning induces profound enhancement in the averaged amplitude of AMPA receptor-mediated miniature synaptic events in piriform cortex pyramidal neurons. Such physiological modifications are apparent at least 4 days after learning completion and outlast learning-induced modifications in the number of spines on these neurons. Also, the averaged amplitude of GABAA receptor-mediated miniature inhibitory synaptic events was significantly enhanced following odor discrimination training. For both excitatory and inhibitory transmission, an increase in miniature postsynaptic current amplitude was evident in most of the recorded neurons; however, some neurons showed an exceptionally great increase in the amplitude of miniature events. For both excitatory and inhibitory transmission, the frequency of spontaneous synaptic events was not modified after learning. These results suggest that olfactory discrimination learning-induced enhancement of synaptic transmission in cortical neurons is mediated by postsynaptic modulation of AMPA receptor-dependent currents and balanced by long-lasting modulation of postsynaptic GABAA receptor-mediated currents.
Attentional control of sensory tuning in human visual perception
Authors: Paltoglou Aspasia E. , Neri Peter
Published: December 2011

Attention is known to affect the response properties of sensory neurons in visual cortex. These effects have been traditionally classified into two categories: 1) changes in the gain (overall amplitude) of the response; and 2) changes in the tuning (selectivity) of the response. We performed an extensive series of behavioral measurements using psychophysical reverse correlation to understand whether/how these neuronal changes are reflected at the level of our perceptual experience. This question has been addressed before, but by different laboratories using different attentional manipulations and stimuli/tasks that are not directly comparable, making it difficult to extract a comprehensive and coherent picture from existing literature. Our results demonstrate that the effect of attention on response gain (not necessarily associated with tuning change) is relatively aspecific: it occurred across all the conditions we tested, including attention directed to a feature orthogonal to the primary feature for the assigned task. Sensory tuning, however, was affected primarily by feature-based attention and only to a limited extent by spatially directed attention, in line with existing evidence from the electrophysiological and behavioral literature.
Asymptotic Behavior of the Navier‐Stokes Equations with Nonzero Far‐Field Velocity
Authors: Roh Jaiok
Published: December 2011

Concerning the nonstationary Navier‐Stokes flow with a nonzero constant velocity at infinity, the temporal stability has been studied by Heywood (1970, 1972) and Masuda (1975) in L2 space and by Shibata (1999) and Enomoto‐Shibata (2005) in Lp spaces for p ≥ 3. However, their results did not include enough information to find the spatial decay. So, Bae‐Roh (2010) improved Enomoto‐Shibata′s results in some sense and estimated the spatial decay even though their results are limited. In this paper, we will prove temporal decay with a weighted function by using Lr − Lp decay estimates obtained by Roh (2011). Bae‐Roh (2010) proved the temporal rate becomes slower by (1 + σ)/2 if a weighted function is |x|σ for 0 < σ < 1/2. In this paper, we prove that the temporal decay becomes slower by σ, where 0 < σ < 3/2 if a weighted function is |x|σ. For the proof, we deduce an integral representation of the solution and then establish the temporal decay estimates of weighted Lp‐norm of solutions. This method was first initiated by He and Xin (2000) and developed by Bae and Jin (2006, 2007, 2008).