bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions between tidal turbine wakes: experimental study of a group of three-bladed rotors
Authors: Stallard T. , Collings R. , Feng T. , Whelan J.
Published: January 2013

It is well known that a wake will develop downstream of a tidal stream turbine owing to extraction of axial momentum across the rotor plane. To select a suitable layout for an array of horizontal axis tidal stream turbines, it is important to understand the extent and structure of the wakes of each turbine. Studies of wind turbines and isolated tidal stream turbines have shown that the velocity reduction in the wake of a single device is a function of the rotor operating state (specifically thrust), and that the rate of recovery of wake velocity is dependent on mixing between the wake and the surrounding flow. For an unbounded flow, the velocity of the surrounding flow is similar to that of the incident flow. However, the velocity of the surrounding flow will be increased by the presence of bounding surfaces formed by the bed and free surface, and by the wake of adjacent devices. This paper presents the results of an experimental study investigating the influence of such bounding surfaces on the structure of the wake of tidal stream turbines.
Energy potential of a tidal fence deployed near a coastal headland
Authors: Draper S. , Borthwick A. G. L. , Houlsby G. T.
Published: January 2013

Enhanced tidal streams close to coastal headlands appear to present ideal locations for the deployment of tidal energy devices. In this paper, the power potential of tidal streams near an idealized coastal headland with a sloping seabed is investigated using a near-field approximation to represent a tidal fence, i.e. a row of tidal devices, in a two-dimensional depth-averaged numerical model. Simulations indicate that the power extracted by the tidal fence is limited because the flow will bypass the fence, predominantly on the ocean side, as the thrust applied by the devices increases. For the dynamic conditions, fence placements and headland aspect ratios considered, the maximum power extracted at the fence is not related in any obvious way to the local undisturbed kinetic flux or the natural rate of energy dissipation due to bed friction (although both of these have been used in the past to predict the amount of power that may be extracted). The available power (equal to the extracted power net of vertical mixing losses in the immediate wake of devices) is optimized for devices with large area and small centre-to-centre spacing within the fence. The influence of energy extraction on the natural flow field is assessed relative to changes in the M2 component of elevation and velocity, and residual bed shear stress and tidal dispersion.
Evaluation of the durability of composite tidal turbine blades
Authors: Davies Peter , Germain Grégory , Gaurier Benoît , Boisseau Amélie , Perreux Dominique
Published: January 2013

The long-term reliability of tidal turbines is critical if these structures are to be cost effective. Optimized design requires a combination of material durability models and structural analyses. Composites are a natural choice for turbine blades, but there are few data available to predict material behaviour under coupled environmental and cycling loading. The present study addresses this problem, by introducing a multi-level framework for turbine blade qualification. At the material scale, static and cyclic tests have been performed, both in air and in sea water. The influence of ageing in sea water on fatigue performance is then quantified, and much lower fatigue lives are measured after ageing. At a higher level, flume tank tests have been performed on three-blade tidal turbines. Strain gauging of blades has provided data to compare with numerical models.
Blockage effects on the hydrodynamic performance of a marine cross-flow turbine
Authors: Consul Claudio A , Willden Richard H. J , McIntosh Simon C
Published: January 2013

This paper explores the influence of blockage and free-surface deformation on the hydrodynamic performance of a generic marine cross-flow turbine. Flows through a three-bladed turbine with solidity 0.125 are simulated at field-test blade Reynolds numbers,
O
(10
5
–10
6
), for three different cross-stream blockages: 12.5, 25 and 50 per cent. Two representations of the free-surface boundary are considered: rigid lid and deformable free surface. Increasing the blockage is observed to lead to substantial increases in the power coefficient; the highest power coefficient computed is 1.23. Only small differences are observed between the two free-surface representations, with the deforming free-surface turbine out-performing the rigid lid turbine by 6.7 per cent in power at the highest blockage considered. This difference is attributed to the increase in effective blockage owing to the deformation of the free surface. Hydrodynamic efficiency, the ratio of useful power generated to overall power removed from the flow, is found to increase with blockage, which is consistent with the presence of a higher flow velocity through the core of the turbine at higher blockage ratios. Froude number is found to have little effect on thrust and power coefficients, but significant influence on surface elevation drop across the turbine.
A large-eddy simulation study of wake propagation and power production in an array of tidal-current turbines
Authors: Churchfield Matthew J. , Li Ye , Moriarty Patrick J.
Published: January 2013

This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally periodic precursor simulation is performed to create turbulent flow data. Then those data are used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modelled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. We found that staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement. For example, using a larger precursor domain would better capture elongated turbulent structures, and including salinity and temperature equations would account for density stratification and its effect on turbulence. Additionally, the wall shear stress modelling could be improved, and more array configurations could be examined.
Marine current energy conversion: the dawn of a new era in electricity production
Authors: Bahaj AbuBakr S.
Published: January 2013

Marine currents can carry large amounts of energy, largely driven by the tides, which are a consequence of the gravitational effects of the planetary motion of the Earth, the Moon and the Sun. Augmented flow velocities can be found where the underwater topography (bathymetry) in straits between islands and the mainland or in shallows around headlands plays a major role in enhancing the flow velocities, resulting in appreciable kinetic energy. At some of these sites where practical flows are more than 1 m s
−1
, marine current energy conversion is considered to be economically viable. This study describes the salient issues related to the exploitation of marine currents for electricity production, resource assessment, the conversion technologies and the status of leading projects in the field. This study also summarizes important issues related to site development and some of the approaches currently being undertaken to inform device and array development. This study concludes that, given the highlighted commitments to establish favourable regulatory and incentive regimes as well as the aspiration for energy independence and combating climate change, the progress to multi-megawatt arrays will be much faster than that achieved for wind energy development.
1-Hydroxy-1H-benzo[d][1,2,6]oxazaborinin-4(3H)-one
Authors: Sarina Evan A. , Olmstead Marilyn M. , Nguyen Dung N. , Groziak Michael P.
Published: January 2013

The structure of the title compound, C7H6BNO3, a new boron heterocycle, prepared by the condensation of (2-ethoxycarbonylphenyl)boronic acid and hydroxylamine, reveals the specific mode of intramolecular condensation between a phenylboronic acid and anorthohydroxamic acid substituent. The crystal structure shows that dehydration occurs to form a planar oxazaborinine ring possessing both phenol-like B—O—H and lactam functional groups. In the extended structure, intermolecular hydrogen bonding generates a 14-membered ring. To our knowledge, this is the first crystal structure determination involving a six-membered ring that exhibits consecutive B—OH, O, NH, and C=O functional groups.
Ca10(CrVO4)6(CrVIO4), a disordered mixed-valence chromium compound exhibiting inversion twinning
Authors: Gyepesová Dalma , Langer Vratislav
Published: January 2013

The structure analysis of so-called 9CaO·4CrO3·Cr2O3proved it to be the title compound, decacalcium hexakis[chromate(V)] chromate(VI), with the simultaneous presence of unusual chromium oxidation states. The structure determination was carried out on a crystal that had inversion twinning. The CrVIO4tetrahedron is situated on a threefold axis and is disordered over two possible orientations that share three O atoms, while the CrVO4tetrahedra are in general positions and are ordered. The charge is balanced by Ca2+cations, one of which is located on a threefold axis. The Ca2+ions are coordinated by six, seven or eight O atoms. The compound is a significant phase in the CaO–CrOxsystem and its formation reduces the refractoriness of calcium-rich compositions in an oxidizing atmosphere.
Aripiprazole salts. III. Bis(aripiprazolium) oxalate–oxalic acid (1/1)
Authors: Freire Eleonora , Polla Griselda , Baggio Ricardo
Published: January 2013

The asymmetric unit of the title salt [systematic name: bis(4-(2,3-dichlorophenyl)-1-{4-[(2-oxo-1,2,3,4-tetrahydroquinolin-7-yl)oxy]butyl}piperazin-1-ium) oxalate–oxalic acid (1/1)], 2C23H28Cl2N3O2+·C2O42−·C2H2O4, consists of one protonated aripiprazole unit (HArip+), half an oxalate dianion and half an oxalic acid molecule, the latter two lying on inversion centres. The conformation of the HArip+cation differs from that in other reported salts and resembles more the conformation of neutral Arip units in reported polymorphs and solvates. The intermolecular interaction linking HArip+cations is also similar to those in reported Arip compounds crystallizing in the space groupP\overline{1}, with head-to-head N—H...O hydrogen bonds generating centrosymmetric dimers, which are further organized into planar ribbons parallel to (01\overline{2}). The oxalate anions and oxalic acid molecules form hydrogen-bonded chains running along [010], which `pierce' the planar ribbons, interacting with them through a number of stronger N—H...O and weaker C—H...O hydrogen bonds, forming a three-dimensional network.
1-Tosyl-4-[2-(trifluoromethyl)benzyl]piperazine
Authors: Sreenivasa S. , Anitha H. C. , ManojKumar K. E. , Tonannavar J. , Jayashree Yenagi , Suchetan P. A. , Palakshamurthy B. S.
Published: January 2013

In the crystal structure of the title compound, C19H21F3N2O2S, the piperazine ring adopts a chair conformation. The dihedral angles between the mean plane of the piperazine ring and the tosyl and trifluoromethylphenyl rings are 74.52 (3) and 68.30 (2)°, respectively. The sulfonamide N atom deviates from the plane defined by the three attached atoms by 0.327 (1) Å. The crystal structure is stabilized by weak C—H...π interactions.
3-Chloro-4-fluoroanilinium picrate
Authors: Sarojini Balladka K. , Narayana Badiadka , Yathirajan Hemmige S. , Gerber Thomas , van Brecht Benjamin , Betz Richard
Published: January 2013

In the title picrate salt of a dihalogenated aniline derivative, C6H6ClF+·C6H2N3O7−, the intracyclic C—C—C angles in the picrate anion cover a broad range [111.95 (12)–125.38 (13)°], while those in the aromatic cation span a much narrower range [118.25 (14)–122.33 (13)°]. In the crystal, classical N—H...O hydrogen bonds, as well as C—H...O contacts, connect the ions into layers parallel to (001).
3-(3,4-Dimethoxybenzyl)chroman-4-one
Authors: Shalini S. , Girija C. R. , Simon Lalitha , Srinivasan K. K. , Venkatesha T. V. , Jotani M. M.
Published: January 2013

In the title compound, C18H18O4, the six-membered chroman-4-one ring adopts an envelope conformation with the C atom bonded to the bridging CH2atom as the flap. The dihedral angle between the mean plane of the fused pyranone ring and the dimethoxy-substituted benzene ring is 89.72 (2)°. In the crystal, adjacent molecules are linkedviaC—H...π interactions.
rac-1-[6-Hydroxy-4-(4-methoxyphenyl)-3,6-dimethyl-4,5,6,7-tetrahydro-2H-indazol-5-yl]ethanone
Authors: Potekhin Konstantin A. , Askerov Rizvan K. , Hajiyeva Kushvar E. , Gadirova Narmina A. , Nazarov Shahkaram I.
Published: January 2013

The title compound, C18H22N2O3, represents a (4S,5R,6S)-stereoisomer, crystallizing as a racemate in a centrosymmetric space group. The six-membered aliphatic ring adopts a half-chair conformation, with the hydroxy- and acetyl-substituted C atoms deviating by 0.458 (2) and −0.366 (2) Å, respectively, from the plane defined by other four ring atoms. The pyrazole ring is essentially planar [r.m.s deviation = 0.004 (2) Å]. In the crystal, the molecules are linked into chains along thebaxis by N—H...N hydrogen bonds. The chains are linked by O—H...N hydrogen bonds into layers parallel to thebcplane.
Maternal effects and ecological divergence in aquatic plants: a case study in natural reciprocal hybrids between Potamogeton perfoliatus and P. wrightii
Authors: IIDA SATOKO , KADONO YASURO , KOSUGE KEIKO
Published: January 2013

When parental taxa are adapted to different habitats, hybrid genotypes are often highly heterogeneous, such that habitat or ecological factors influence hybrid fate and ecological performance. Trait expression in hybrids is not always intermediate between the parents, but may instead be either parental‐like or extreme (transgressive) depending on genetic control of the phenotypes. Maternal effects arising from interspecific interaction between cytoplasmic and nuclear genomes are widely recognized as playing a role in character expression of natural hybrids. Such interaction often leads to hybrid sterility or inviability. When hybrids are viable, however, cytonuclear interaction may contribute to hybrid persistence through its influence on trait expression. To date, maternal influence on hybrid performance has been examined primarily in experimentally produced hybrids, or in natural hybrids without identification of the cross direction owing to difficulty in obtaining species‐specific molecular markers. In aquatic plants, many hybrids persist by extensive clonal growth and are important components of aquatic communities. Many such hybrids are known in Potamogeton (pondweeds), the largest aquatic genus. Because Potamogeton species are ecologically highly diverse and maternal lineages are readily distinguished using molecular markers, natural hybrids of Potamogeton are well‐suited for studies of maternal effects, especially those affecting vegetative performance. As a case study, we have focused on maternal effects on drought tolerance and depth distribution in the natural hybrid P. × anguillanus derived from the closely related species P. perfoliatus and P. wrightii.
The ‘Hows’, not the ‘Whys’ or the ‘Wherefores’: The Role of Intra‐party Competition in the 2011 Breakthrough of the True Finns
Authors: Arter David
Published: January 2013

From minor party status, the True Finn Party (PS) claimed nearly one‐fifth of the vote and almost the same proportion of parliamentary seats at the April 2011 Finnish general election. It registered the largest gains made by any party in postwar Finnish history, thus writing – in the eyes of foreign journalists at least – yet another chapter in the surge of populist radical right parties across contemporary Europe. This article, however, is concerned more with how the substantial PS vote was mobilised than with how much was mobilised. The idea is not to identify the primary causes of the PS's national breakthrough, but to explore the internal dynamics of party's explosive growth and the process of translating a large prospective vote into ‘hard votes’ through the ballot boxes. The focus is on district‐level nomination strategies, the range of candidate types, the mechanics of vote optimisation and the distribution of the personal vote. With regard to the latter, the article seeks to measure and analyse the role of intra‐party competition in the anatomy of party transformation and to do so by the novel means of adapting the Laakso‐Taagepera index to measure the ‘effective number of co‐partisans’. Significantly, at the 2011 Eduskunta election the PS exhibited the highest level of intra‐party competition of any of the eight parliamentary parties.
Kidney biopsy in pregnancy: evidence for counselling? A systematic narrative review
Authors: Piccoli GB , Daidola G , Attini R , Parisi S , Fassio F , Naretto C , Deagostini MC , Castelluccia N , Ferraresi M , Roccatello D , Todros T
Published: January 2013

Background

Kidney diseases, which have a prevalence of 3% in women of childbearing age, are increasingly encountered in pregnancy. Glomerulonephritis may develop or flare up in pregnancy, and a differential diagnosis with pre‐eclampsia may be impossible on clinical grounds. Use of kidney biopsy is controversial, but a systematic review has not been carried out to date.

Objectives

To review the literature on kidney biopsy in pregnancy, with a focus on indications, risks and timing.

Search strategy

Medline, Embase, CHINAL and the Cochrane Library were searched in September 2012, with ‘pregnancy’ and ‘kidney biopsy’ used as MESH and free terms, for the period 1980–2012. Results were filtered for ‘human’ if this option was available.

Selection criteria

Biopsies during pregnancy and within 2 months after delivery. Case reports (fewer than five cases) and kidney grafts were excluded. Paper selection was performed in duplicate.

Data collection and analysis

Data were extracted in duplicate. The high heterogeneity in study design necessitated that the review be narrative, except for data on adverse events, which were analysed with regard to the timing of kidney biopsy.

Main results

Of 949 references, 39 were selected, providing data on 243 biopsies in pregnancy and 1236 after delivery (timing was unclear in 106 women). The main aims of the studies were to define morphology in pre‐eclampsia (23 studies), to carry out a risk–benefit analysis of kidney biopsy (11 studies), and to investigate pregnancy‐related acute kidney injury (five studies). Four cases of major bleeding complications occurred at 23–26 weeks of gestation. Relevant complications were observed in 7% of women during pregnancy and 1% after delivery (P = 0.001). Kidney biopsy performed for the diagnosis of glomerulonephritis or pre‐eclampsia led to therapeutic changes in 66% of cases.

Authors’ conclusions

The evidence on kidney biopsy in pregnancy is heterogeneous, but a significantly higher risk of complications (relative to postpartum biopsy) was found, with a possible peak at around 25 gestational weeks.
Label‐free quantification for discovering novel biomarkers in the diagnosis and assessment of disease activity in inflammatory bowel disease
Authors: Han Na‐Young , Choi Wooseok , Park Jong‐Moon , Kim Eun Hee , Lee Hookeun , Hahm Ki‐Baik
Published: January 2013

Objective

No distinctive biomarkers capable of discriminating between ulcerative colitis (UC) and Crohn's disease (CD) have yet been found. In this study, we aimed to discover these biomarkers by using advanced label‐free quantification technology for proteomes.

Methods

Biomarker protein expressions of colonic tissues of Korean IBD patients and controls were determined using label‐free quantification to compare the protein profiles of colonic mucosa in three individuals with normal colonic tissue, four patients with UC, three with CD and two with inflammatory polyps related to UC. A computational framework and tools for discovery‐based liquid chromatography‐tandem mass spectrometry proteomics was applied to draw the biomarkers.

Results

In total, 339 proteins were identified in normal sample group, 217 and 283 proteins in active and inactive UC, 345 and 366 proteins in active and inactive CD and 392 proteins in inflammatory polyps related to UC, respectively. The findings were reproducible. A Corra analysis led to the discovery of 27 potential biomarkers in UC, 37 biomarkers relevant to CD and 11 proteins commonly associated with IBD. Three novel proteins, PRG2, LCP1 and PSME1 were identified as biomarkers signifying active CD.

Conclusion

This is the first study to apply label‐free quantification for discovering biomarkers in patients with different types and stages of IBD, providing additional insights for revealing the molecular pathogenesis of IBD as well as protein biomarkers of IBD predicting responses to treatment.
A New Chinese Anurognathid Pterosaur and the Evolution of Pterosaurian Tail Lengths
Authors: Junchang LÜ , HONE David W.E.
Published: January 2013

A new anurognathid pterosaur specimen from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebie Province is described. The new specimen is referred to Dendrorhynchoides, based on the general morphology of the skeleton, but it represents a new species, named here as Dendrorhynchoides mutoudengensis sp. nov.. It is characterized by the presence of short, robust and straight teeth, and bearing wing metacarpal approximately 40% of the length of humerus. The new specimen provides further osteological information for anurognathid pterosaurs, especially the presence of a relatively elongate tail.
The Flight Dynamics of Tapejara, a Pterosaur From the Early Cretaceous of Brazil with a Large Cranial Crest
Authors: CHATTERJEE Sankar , TEMPLIN R. Jack
Published: January 2013

Tapejara wellnhoferi, a small azhdarchoid pterodactyloid from the Early Cretaceous Santana Formation of Brazil, provides critical information about the aerodynamic function of its spectacular head crest. The cranial crests in pterodactyloids were sexually dimorphic and are thought to have evolved in adult males in response to female mate choice. However, the location of cranial crests in front of the center of gravity would create instability in the yaw axis during flight and may seem like a handicap. Vertically aligned webbed feet probably suppressed the yawing rotations and instability from the crest. Here we show that the crest functioned as a front rudder to make agile turn and mediate flight control. A computer simulation model suggests that Tapejara had a large excess of muscle power available above the power required for continuous flapping flight. It could easily takeoff from a perch, ground, or water surface and land safely on the ground. It was an excellent glider with a gliding angle close to 4° and a cruising speed of 27 km/h. Tapejara could soar efficiently on the windward side of cliffs or circle on rising thermals over tropical waters for efficient long‐distance flight. Various control surfaces in the wings of Tapejara analogous to the slat, aileron, elevator, fin, rudder, and horizontal stabilizer of an aircraft made pterodactyloids versatile flyers.
Dragon Tails: Convergent Caudal Morphology in Winged Archosaurs
Authors: PERSONS W. Scott , CURRIE Philip J.
Published: January 2013

In the tails of dromaeosaurid dinosaurs and rhamphorhynchid pterosaurs, elongate osteological rods extend anteriorly from the chevrons and the prezygapophyses. These caudal rods are positioned in parallel and are stacked dorsoventrally. The fully articulated and three‐dimensionally preserved caudal series of some dromaeosaurid specimens show that individually these caudal rods were flexible, not rigid as previously thought. However, examination of the arrangement of the caudal rods in cross‐section indicates that the combined effect of multiple caudal rods did provide substantial rigidity in the dorsoventral, but not in the lateral, plane. The results of digital muscle reconstructions confirm that dromaeosaurids and rhamphorhynchids also shared greatly reduced caudofemoral muscles in the anterior tail region. The striking similarities between the tails of dromaeosaurids and rhamphorhynchids suggest that both evolved under similar behavioral and biomechanical pressures. Combined with recent discoveries of primitive deinonychosaurs that phylogenetically bracket the evolution of dromaeosaurid caudal rods between two arboreal gliding/flying forms, these results are evidence that the unique caudal morphologies of dromaeosaurids and rhamphorhynchids were both adaptations for an aerial lifestyle.
Radiolarians from the Pohang Basin, Southeast Korea and Paleoceanographic Implications
Authors: BAK Young‐Suk , LEE Jong‐Deock , YUN Hyesu , OH Jinyong , LEE Seong‐Joo
Published: January 2013

We identified a total of 101 species and two subspecies of radiolarians belonging to 56 genera from 95 samples collected from the Hagjeon and Duho Formations in the Pohang Basin of the southeastern Korean Peninsula. On the basis of the biostratigraphic range of Cyrtocapsella cornuta and Theocorys redondoensis, the depositional period of the upper Hagjeon and lowest Duho Formations was determined to be early to late Middle Miocene. The occurrence of deep‐dwelling radiolarians indicates that the paleobathymetry seems to become gradually progressing toward an upper bathyal environment in the middle part of the Hagjeon Formation. However, we prefer to accept another interpretation for the occurrence of deep‐sea indicators in the Hagjeon and the lowest part of the Duho Formations, and consider the presence of a region of upwelling cold water that might have simulated a deep‐water environment in relatively shallow water. This interpretation is based on the present upwelling of a cold‐water mass off the southeast coast of Korea, the occurrence of upwelling microfossils from the Pohang Basin, and the effect of the closing of the Korea Strait approximately 15 Ma. We also considered that the uppermost part of the studied section represents a shallow‐water environment.
Calcareous Nannoplankton Biostratigraphy of the Bartin Province, Western Black Sea, Turkey
Authors: OZER Caner Kaya , TOKER Vedia
Published: January 2013

Calcareous nannoplankton biostratigraphy has been performed on five sedimentary sections through the marine Akveren Formation from the Bartin region of northern Turkey, on the southern Black Sea coast. This new biostratigraphy provides an age for the formation of the Early Campanian (nannofossil zone UC15aTP) to Early Selandian (nannofossil zone NP5), and highlights the presence of the Campanian/Maastrichtian, Cretaceous/Tertiary (K/T), and Danian/Selandian boundaries in this intermediate palaeolatitude location.Micula muruswas identified below the K/T boundary, butMicula prinsiiandNephrolithus frequenswere not, which implies that the K/T boundary interval is not complete in the study area. These dates are in agreement with previous micropaleontological studies.
40Ar‐39Ar Geochronology and Tectonic Implications of the Blueschist from Northwestern Qiangtang, Northern Tibet, Western China
Authors: Xianchun TANG , Kaijun ZHANG
Published: January 2013

Blueschist exposed in the northwestern Qiangtang terrane, northern Tibet, western China (∼84°30′ E, 34°24′ N), provides new constraints on the tectonic evolution of Qiangtang as well as northern Tibet. The blueschist represented by lawsonite‐ and glaucophane‐bearing assemblages equilibrated at 375–400 °C and ∼11 kbar. 40Ar‐39Ar analysis on mineral separate from one blueschist sample yielded a well‐defined plateau age of ∼242 Ma. Geochemical studies show the blueschist is metamorphosed within‐plate basalts. The high pressure‐low temperature blueschist indicates a Triassic event of lithosphere subduction, and clearly represents an extension of the central Qiangtang metamorphic belt, and defines an in situ suture between eastern and western Qiangtang.
Zircon U‐Pb Age and Geochemistry of the Ore‐hosting Ultramafic Complex of Zhou'an PGE‐Cu‐Ni Deposit, Henan Province, Central China
Authors: Haiqing YAN , Ruiying DING , Zhongli TANG , Yalei WANG , Shuang LIU , Jiahong MA , Yanqiang HU , Kena CHEN
Published: January 2013

The Zhou'an PGE‐Cu‐Ni deposit was recently discovered in the Qinling orogenic belt bound by the Yangtze and the North China Cratons. It is a blind deposit thoroughly covered by the Cenozoic alluvial sediments in the Nanyang Basin. As the first large PGE‐Cu‐Ni deposit discovered in the Qinling‐Dabie‐Sulu orogenic belt, its geological and geochemical characteristic, isotope age, genesis and tectonic setting are of wide concern in both scientific studies and ore exploration. In this contribution, we report the results obtained from a pioneering study. The Zhou'an ultramafic complex is ferruginous, with m/f = 4.79–5.08, and shows the nature of tholeiite series. It is rich in light rare earth elements, Rb, Th, U, La, Sm, Zr and Hf, and poor in heavy rare earth elements, Nd and Ta, suggesting an intraplate setting. It has high 87Sr/86Sr and low 143Nd/144Nd ratios. The ratios of Zr/Nb, La/Nb, Ba/Nb, Rb/Nb, Th/Nb, Th/La and Ba/La, suggest the magma originated from lithosphere mantle. The Fo values of olivine and Pd/Ir‐Ni/Cu diagram suggest primary magma was High Mg basalt. The laser ablation inductively coupled plasma atomic emission spectroscopy zircon U‐Pb age is 641.5 ± 3.7 Ma.
Fault Systems and their Control of Deep Gas Accumulations in Xujiaweizi Area
Authors: Yonghe SUN , Lin KANG , Haifeng BAI , Xiaofei FU , Ming HU
Published: January 2013

A study of faults and their control of deep gas accumulations has been made on the basis of dividing fault systems in the Xujiaweizi area. The study indicates two sets of fault systems are developed vertically in the Xujiaweizi area, including a lower fault system and an upper fault system. Formed in the period of the Huoshiling Formation to Yingcheng Formation, the lower fault system consists of five fault systems including Xuxi strike‐slip extensional fault system, NE‐trending extensional fault system, near‐EW‐trending regulating fault system, Xuzhong strike‐slip fault system and Xudong strike‐slip fault system. Formed in the period of Qingshankou Formation to Yaojia Formation, the upper fault system was affected mainly by the boundary conditions of the lower fault system, and thus plenty of multi‐directionally distributed dense fault zones were formed in the T2 reflection horizon. The Xuxi fault controlled the formation and distribution of Shahezi coal‐measure source rocks, and Xuzhong and Xudong faults controlled the formation and distribution of volcanic reservoirs of Y1 Member and Y3 Member, respectively. In the forming period of the upper fault system, the Xuzhong fault was of successive strong activities and directly connected gas source rock reservoirs and volcanic reservoirs, so it is a strongly‐charged direct gas source fault. The volcanic reservoir development zones of good physical properties that may be found near the Xuzhong fault are the favorable target zones for the next exploration of deep gas accumulations in Xujiaweizi area.
Disease outcomes and nodal recurrence in patients with papillary thyroid cancer and lateral neck nodal metastases
Authors: O'Neill Christine J. , Coorough Nicholas , Lee James C. , Clements Joshua , Delbridge Leigh W. , Sippel Rebecca , Sywak Mark S. , Chen Herb , Sidhu Stan B.
Published: January 2013

Background

The prognostic influence of lateral neck nodal metastases present at the time of diagnosis of papillary thyroid cancer (PTC) remains controversial. This study aims to document disease outcomes and nodal recurrence rates in such patients.

Methods

Patients with PTC and lateral neck nodal metastases who underwent concurrent total thyroidectomy, central and lateral compartment neck dissection between 2000 and 2010 were identified from the prospectively maintained surgical databases of The University of Sydney and University of Wisconsin Endocrine Surgical Units. Disease outcomes and nodal recurrence rates were compared at 12 months post‐operatively and in longer‐term follow‐up.

Results

During this 11‐year period, 121 patients were identified. Mean age was 45 years; 58% were female and 98% underwent post‐operative radioactive iodine ablation. At a median follow‐up of 31 months (range 12–140), there were no disease‐specific deaths and disease‐free survival (defined by stimulated serum thyroglobulin (Tg) < 2.0 μg/L, negative clinical and radiological examination) was 66%. Of the 50 patients with persistently elevated Tg measured 12 months post‐operatively, 15 developed clinical lateral neck nodal recurrence. All have undergone re‐operative surgery. Elevated stimulated Tg at 12 months post‐operatively and a nodal ratio of >30% were significantly associated with an increased risk of lateral neck nodal recurrence.

Conclusion

With total thyroidectomy, formal compartmental neck dissection and radioactive iodine treatment, disease‐free survival can be achieved in the majority of patients with PTC and synchronous lateral neck nodal metastases. A persistently elevated Tg post‐operatively and a high ratio of metastatic nodes identify patients at increased risk of locoregional recurrence.
Day‐case laparoscopic ventral rectopexy: an achievable reality
Authors: Powar M. P. , Ogilvie J. W. , Stevenson A. R. L.
Published: January 2013

Aim

Laparoscopic ventral rectopexy (LVR) is a non‐resectional technique for selected patients with full‐thickness rectal prolapse and obstructed defaecation syndrome. Despite its challenges, LVR can be performed with relatively minimal patient trauma thus creating the potential for same‐day discharge. Our aim was to assess the safety of day‐case LVR and identify factors associated with same‐day discharge.

Method

Data were prospectively collected on all patients (n = 120) from June 2008 to October 2011. Variables included demographics, perioperative details and postoperative course. Primary outcome was length of stay and secondary outcome was symptom improvement at the latest outpatient follow‐up. Patients discharged the same day after LVR were compared with those who stayed overnight or longer.

Results

Indications included rectocele and internal prolapse (47%), full‐thickness rectal prolapse (44%) and other (9%). Mean operative time was 97 min, same‐day discharge occurred with 23% (n = 27) and 67% (n = 80) were discharged on postoperative day 1. In terms of complications, 89% had none, 8% minor and 3% major, including one 24‐h readmission for pain. Logistic regression identified younger age (P = 0.054) and private insurance status (P < 0.001) as being significantly associated with same‐day discharge. Although surgical indication (P < 0.001), no prior hysterectomy (P = 0.012) and use of biological mesh (P = 0.012) had significant association they were probably confounded by age.

Conclusion

In selected patients with rectal prolapse or obstructed defaecation, same‐day discharge after LVR is feasible and safe. Our analysis identified quicker discharge in the private system with younger patients. Nevertheless, in unselected patients 90% were discharged by the first operative day.
Decrease of postprandial endothelial dysfunction by spice mix added to high‐fat hamburger meat in men with Type 2 diabetes mellitus
Authors: Li Z. , Henning S. M. , Zhang Y. , Rahnama N. , Zerlin A. , Thames G. , Tseng C. H. , Heber D.
Published: January 2013

Aims

Consumption of a high‐fat diet has been demonstrated to promote endothelial dysfunction, possibly through an increase in lipid peroxidation and decrease in serum nitric oxide. The present study was designed to investigate whether consumption of a hamburger cooked with a polyphenol‐rich spice mixture will reduce postprandial lipid oxidation and endothelial dysfunction in men with Type 2 diabetes.

Methods

Twenty‐two subjects consumed burgers cooked with salt only (control burger) or with salt and spice mix (spice burger) in randomized order. The postprandial concentration of urinary malondialdehyde and nitrate/nitrite as well as the peripheral arterial tonometry score were determined.

Results

Eighteen subjects completed the study. Postprandial serum glucose, insulin and triglyceride concentrations were similar in all subjects after control burger or spice burger consumption. Urine malondialdehyde excretion in mmol/g creatinine was reduced by 31% (P < 0.001) after consuming the spice burger compared with the control burger. Two hours after consumption of the burgers, the peripheral arterial tonometry score was significantly different between control burger consumption (−9.7 ± 21.5%) and spice burger consumption (+18.0 ± 42.4%) (P = 0.025). Mean urinary nitrate/nitrite concentrations in urine collected during the 6 h after consumption of the control burger was 9.09 ± 5.7 mmol/g creatinine, but 12.37 ± 7.00 mmol/g creatinine after the spice burger (P = 0.053).

Conclusion

Adding a spice mix to hamburger meat prior to cooking resulted in a reduction in urinary malondialdehyde, an increase in urinary nitrate/nitrite and improvement of postprandial endothelial dysfunction in men with Type 2 diabetes. Therefore, cooking a hamburger with a polyphenol‐rich spice mixture may lead to potential cardiovascular benefits in patients with Type 2 diabetes mellitus.
Tissue Doppler–Derived Contractile Reserve Is a Simple and Strong Predictor of Cardiopulmonary Exercise Performance across a Range of Cardiac Diseases
Authors: McIntosh Robert A. , Silberbauer John , Veasey Rick A. , Raju Prashanth , Baumann Oliver , Kelly Sarah , Beale Louisa , Brickley Gary , Sulke Neil , Lloyd Guy W.
Published: January 2013

Background

Resting echocardiographic measures of cardiac function such as left ventricular ejection fraction correlate poorly with exercise capacity. Assessment during exercise using measures less dependent on hemodynamic loading conditions, such as tissue Doppler imaging (TDI), may more accurately characterize the relationship between cardiac function and exercise capacity.

Methods and Results

One hundred one subjects with various cardiac diagnoses underwent exercise stress echocardiography with simultaneous cardiopulmonary gas exchange analysis. Standard two‐dimensional, Doppler and spectral TDI parameters were assessed at both rest and peak exercise. Across all subjects the strongest relationship with peak oxygen uptake (pVO2) was with peak left ventricular systolic tissue velocity (S′) during exercise (r = 0.84, P < 0.001). The strength of the relationship was greater than that observed with any other common echocardiographic measure of systolic or diastolic cardiac function.

Conclusion

There is a very strong relationship between measurements of S′ during exercise and exercise capacity. The previously observed poor correlation with standard measures of systolic and diastolic cardiac function may be explained both by the load dependence of parameters such as ejection fraction and by reliance on resting as opposed to exercise assessment.
Long‐term fish assemblages respond to habitat and niche breadth in the West Fork White River, Indiana
Authors: Jacquemin Stephen J. , Doll Jason C.
Published: January 2013

Identification of patterns in community structure is a central theme in freshwater ecology. Our objectives were to identify temporal patterns in fish assemblages from 1980 to 2010 in the West Fork White River in east‐central Indiana using the Malthusian growth model and determine whether changes in the population growth rate parameter were related to Grinnellian niche breadth. We studied local‐scale fish assemblages in a Midwestern United States river at 16 sites for a period of 30 years. We used a hierarchical model to estimate population abundance parameters of the Malthusian growth model. Niche breadth was incorporated as a model parameter to explain variation in the population growth rate. Parameters of the model were fit using Bayesian inference. We identified notable changes in the fish assemblages; however, the patterns for temporal trends in individual species abundances were not conserved across sites. Decreasing trends were observed in longear sunfish, striped shiner, white sucker, central stoneroller, common carp and creek chub while bluegill and mimic shiner increased in abundance. Longear sunfish was the only species that exhibited the same trend in abundance for all sites. Niche breadth was inversely related to the population growth rate at sites adjacent to low‐head dam impoundments. We suggest that the presence of multiple impoundments has resulted in a fragmented series of fish assemblages.
Evidence for self‐association of the alternative sigma factor σ54
Authors: Sabbatini Massimo , Vezzoli Alessandro , Milani Mario , Bertoni Giovanni
Published: January 2013

Sigma factor σ54 has a distinct modus operandi for mediating the activation of bacterial RNA polymerase (RNAP) at promoter recognition motifs 12 and 24 bp upstream from transcription start sites. σ54 was thought to act as monomer in all transcription steps. However, we provide evidence that σ54 of Pseudomonas putida interacts stably with itself. The interface between monomers involves contacts in σ54 regions I and III, sequences that play key roles in the transcription activation of σ54–RNAP holoenzyme. These roles include interactions with activator proteins and the −12 and −24 motifs. In particular, we detected inter‐monomer contacts between region I, and between region I and the C–terminal portion of region III. Our results suggest a new auto‐antagonistic regulatory state of σ54.

Structured digital abstract

σ54 and σ54 bind by molecular sieving (View Interaction: 1, 2)

σ54 and σ54 bind by blue native page (View interaction)

P. aeruginosa σ54 physically interacts with P. aeruginosa σ54 by two hybrid (View interaction)

σ54 physically interacts with σ54 by two hybrid (View Interaction: 1, 2, 3)

p53 physically interacts with SV40T by two hybrid (View interaction)
Descriptors of natural thermal regimes in streams and their responsiveness to change in the Pacific Northwest of North America
Authors: ARISMENDI IVAN , JOHNSON SHERRI L. , DUNHAM JASON B. , HAGGERTY ROY
Published: January 2013

1. Temperature is a major driver of ecological processes in stream ecosystems, yet the dynamics of thermal regimes remain poorly described. Most work has focused on relatively simple descriptors that fail to capture the full range of conditions that characterise thermal regimes of streams across seasons or throughout the year.

2. To more completely describe thermal regimes, we developed several descriptors of magnitude, variability, frequency, duration and timing of thermal events throughout a year. We evaluated how these descriptors change over time using long‐term (1979–2009), continuous temperature data from five relatively undisturbed cold‐water streams in western Oregon, U.S.A. In addition to trends for each descriptor, we evaluated similarities among them, as well as patterns of spatial coherence, and temporal synchrony.

3. Using different groups of descriptors, we were able to more fully capture distinct aspects of the full range of variability in thermal regimes across space and time. A subset of descriptors showed both higher coherence and synchrony and, thus, an appropriate level of responsiveness to examine evidence of regional climatic influences on thermal regimes. Most notably, daily minimum values during winter–spring were the most responsive descriptors to potential climatic influences.

4. Overall, thermal regimes in streams we studied showed high frequency and low variability of cold temperatures during the cold‐water period in winter and spring, and high frequency and high variability of warm temperatures during the warm‐water period in summer and autumn. The cold and warm periods differed in the distribution of events with a higher frequency and longer duration of warm events in summer than cold events in winter. The cold period exhibited lower variability in the duration of events, but showed more variability in timing.

5. In conclusion, our results highlight the importance of a year‐round perspective in identifying the most responsive characteristics or descriptors of thermal regimes in streams. The descriptors we provide herein can be applied across hydro‐ecological regions to evaluate spatial and temporal patterns in thermal regimes. Evaluation of coherence and synchrony of different components of thermal regimes can facilitate identification of impacts of regional climate variability or local human or natural influences.
Strategies for the conservation and management of isolated salmonid populations: lessons from Japanese streams
Authors: TSUBOI JUN‐ICHI , IWATA TOMOYA , MORITA KENTARO , ENDOU SHINSUKE , OOHAMA HIDEKI , KAJI KOUICHI
Published: January 2013

1. Endangered native populations of stream salmonids in Japan face three major threats: (i) negative interactions with introduced hatchery‐reared fish, (ii) fragmentation of habitat by impassable dams and (iii) recreational angling.

2. To prevent imminent extinction of many local populations, we evaluated these threats and possible conservation actions for red‐spotted masu salmon (Oncorhynchus masou ishikawae) and white‐spotted charr (Salvelinus leucomaenis japonicus) in the Fuji River system in central Japan.

3. Red‐spotted masu salmon and white‐spotted charr occupied only 0.73 and 2.4% of suitable thermal habitats, respectively, with masu salmon typically occupying habitats closer to human population centres.

4. Population viability analysis resulted in a 100‐year probability of extinction of 78.1% for masu salmon and 48.1% for charr. However, extinction risk of both species was predicted to be <5% if the carrying capacity increased from 141 to 303 for masu salmon and from 94 to 125 for charr, by allowing fish passage at the lower end of the habitat, and if annual adult survival rate increased by 0.04. Adult survival rate was the principal factor associated with population persistence.

5. To conserve isolated populations of stream‐dwelling salmonids, we recommend (i) assessing the distribution of remnant native and non‐native fish populations, (ii) that fishing regulations are modified to improve adult survival and population persistence and (iii) that fragmented reaches be reconnected to adjacent habitat, for example by removing or modifying artificial barriers to increase the carrying capacity of the isolated populations. Reconnection of fragmented reaches should, however, be avoided if it results in non‐native fish invading isolated populations.