bluuebunny/crossref_metadata_2025 huggingface dataset:
VIII.—The Priory of St. Leonard of Stanley, Co. Gloucester, in the light of recent discoveries documentary and structural
Authors: Swynnerton C.
Published: November 2011

Stanley, Co. Glos., is a village on the western slope of a spur of the Cotswolds one and a half miles north of Stonehouse. The village and parish are commonly called Leonard Stanley or Stanley St. Leonards to distinguish them from the next parish of King's Stanley as well as from the Wiltshire Stanley where there was also a conventual house. Occasionally it appears as Stanley Monachorum. But generally it was simply Stanley, and Stanley without qualification is the name which local lips often assign to it even at the present day.

Stanley St. Leonards can boast of two most interesting churches. The older church, now degraded to farm-yard purposes, was the ancient preconquest rectory church, but it is small, a chapel in fact, and therefore, following medieval usage, we shall distinguish it from the greater monastic and present parish church by naming it as the chapel of St. Leonard.
IV.—Excavations at Caerwent, Monmouthshire, on the Site of the Romano-British City of Venta Silurum, in 1901
Authors: Ashby Thomas , Hudd Alfred E. , Martin A. T.
Published: November 2011

The work for the year 1901 began on 10th June, and was continued till 22nd October. It consisted in the excavation of the west wing of House No. 2, the rest of which had been uncovered in 1900, and of the whole of House No. 7. House No. 8, which was partly excavated in 1901, has been completed (with Block A) during June and July of the present year, 1902. Excavations were also carried on in the field adjoining the north gate, now the property of Lord Tredegar, F.S.A., the cost of which was entirely defrayed by him. As, however, these excavations are by no means complete, and many problems which they present still await solution, it has been thought better to postpone all detailed report of this portion of the work until next year.
XI.—The London Charterhouse and its old water supply
Authors: Hope W. H. St. John
Published: November 2011

It is written in the fifth volume of the Minute Books of the Society that on Thursday, 1st May, 1746:

Mr. Birch brought an old draft in a Parchment Roll done in the year 1511 of all the Stone-Wells then at Clerkenwell. This Mr. Vertue was desired to take home and give some account to the Society the next meeting: the Roll is the property of Francis Godolphin, Esq.
I.—A Second Silver Treasure from Cyprus
Authors: Dalton Ormonde M.
Published: November 2011

In the early summer of 1902 a large and important discovery of Byzantine silver plate and gold jewellery was made at Karavás, a village close to the ancient Lapithos, about six miles west of Kyrenia on the north coast of Cyprus. The spot was not far from the monastery of Acheiropoietos, close to which another find of silver of a similar period had been made a few years previously, the objects being acquired by the British Museum and described inArchaeologia.
VII.—Excavations at Caerwent, Monmouthshire, on the Site of the Romano-British City of Venta Silurum, in the year 1905
Authors: Ashby T.
Published: November 2011

The South Gate could not be excavated in 1904 at the time when Houses Nos. X-XIII were laid bare, owing to the existence of a fine walnut tree which it was then impossible to remove. Permission to cut down the tree was, however, kindly given by the trustees of the late Mr. John Lysaght, in 1905, and the uncovering of the South Gate was therefore the first piece of work undertaken in that year.
IX.—Excavations on the site of the Roman city at Silchester, Hants, in 1905
Authors: Hope W. H. St. John
Published: November 2011

I Have the honour of laying before you to-night, on behalf of my colleagues, the sixteenth detailed report of the Executive Committee of the Silchester Excavation Fund, that for the year 1905.

The excavations last year extended over the six months from 19th May to 18th November, and were carried out under the direction and supervision of our colleague Mr. Mill Stephenson, to whom we have again to express our grateful thanks for his ungrudging and freely given help.
VI.—Excavations on the site of the Roman city at Silchester, Hants, in 1907
Authors: Hope W. H. St. John
Published: November 2011

I have the honour of submitting to the Society, on behalf of my colleagues of the Executive Committee of the Silchester Excavation Fund, the report of our investigations during the six months from the 17th May to 27th November of last year (1907), being the eighteenth successive season of our exploration of the site.

In pursuance of the plan foreshadowed in last year's report, our investigations for 1907 were resumed in the grass field which occupies a considerable area near the middle of the Roman site.
V.—Irish Bronze Pins of the Christian Period
Authors: Armstrong E. C. R.
Published: November 2011

A classification of the numerous bronze pins found in Ireland is to be desired. Wilde, who figured over thirty specimens of various kinds, made no separation between Bronze and Early Iron Age pins and those of the Christian period. Coffey devoted some pages to pins, reproducing a number of Wilde's illustrations; he did not, however, attempt any classification, merely stating that, with the exception of the ‘hand-type’ and other pins of that class showing decoration earlier than the interlaced style, the approximate date of the majority might be taken as the tenth to the eleventh century.
XI.—On the Pottery from the Waste Heap of the Roman Potters' Kilns discovered at Sandford, near Littlemore, Oxon., in 1879
Authors: May Thomas
Published: November 2011

In cutting drains for the Oxford sewage distribution on Mynchery Farm, Sandford, Oxon.. near the Thames, in 1879, four potters' kilns and other Roman remains were discovered, and systematic exploration of the site was then undertaken by the late George Rolleston, F.R.S., Linacre Professor of Physiology, assisted in the work by our Fellow Mr. Heneage Cocks, who studied anatomy under Professor Rolleston, and by the sewage engineers Messrs. Cobbold Brothers. Unfortunately the Professor died before fully working out the results of the exploration, and only a brief summary appears in the appendix to his Scientific Papers and Addresses (1884), ii, 937.
XXII.—On the Music in the Painted Glass of the Windows in the Beauchamp Chapel at Warwick
Authors: Hardy Charles Frederic
Published: November 2011

The history of the foundation and building of the Beauchamp Chapel at Warwick is contained (or rather was contained) in certain documents which were formerly amongst the municipal archives, but which (as I have been informed by the town clerk) are supposed to have perished in the great fire of Warwick in 1694. Fortunately full extracts from these documents are given in Dugdale's Antiquities of Warwickshire. Hence we learn that the chapel, which almost immediately adjoins the south side of the chancel of St. Mary's church, was founded and dedicated in honour of Our Lady in pursuance of the will of Richard Beauchamp, Earl of Warwick, who died in 1439. The earl was a man of almost European fame in his day, of great and varied achievement, and of vast wealth. His daughter Anne, who ultimately became the heiress of his only son, was the wife of Richard Neville, who also became Earl of Warwick and is well known in English history as the King-maker.
IV.—A Bronze Head of Athena at Burleigh Court, Gloucestershire
Authors: Forster Edward Seymour
Published: November 2011

By kind permission of the owner, my friend Mr. Edward F. Elton of Burleigh Court near Stroud, I am able to call attention to an unpublished antique bronze head in his collection (pi. ix).

Nothing is known of its history before it came into his hands, but it has obviously been at one time buried in the ground, and particles of earth are ingrained in the patina over a portion of the surface. It has evidently been roughly broken off from the body, the edge in front being jagged, while behind it is flush with the bottom of the helmet. The scale is two-thirds of life size. The head is hollow-cast and shows considerable variations of thickness, some parts being so thin that they have worn through; in particular about half the surface at the top of the crest has perished. The head should probably be pitched more forward than the position in which it is now mounted.
V.—The High Terrace of the Thames: Report on Excavations made on behalf of the British Museum and H.M. Geological Survey in 1913
Authors: Smith Reginald A. , Dewey Henry
Published: November 2011

The joint investigation of the deposits belonging to the 100-ft. terrace of the river Thames was continued last year under the same auspices as in 1912 at certain spots in the neighbourhood of Greenhithe and Crayford, respectively east andwest of Dartford, Kent. Special facilities were again afforded by the Trustees ofthe British Museum and the Director of the Geological Survey; but the fund drawn on for this work is under the control of Sir Hercules Read, who in his dual capacity as President of the Society and Keeper of the British and Medieval Departmentof the British Museum is anxious to sustain the effort that is being made to bring archaeology into touch with geology, and is at the same time gratified to enlist the sympathies of unofficial workers by having the report presented to the Society.
V.—A Roll of Household Accounts of Sir Hamon le Strange of Hunstanton, Norfolk, 1347–8
Authors: le Strange Hamon
Published: November 2011

About eighty-four years ago the late Daniel Gurney, F.S.A., published in Archaeologia (xxv, 411–569) some extracts from the Household Accounts of the le Stranges of Hunstanton during the reigns of Henry VIII and his children. The Muniment Room at Hunstanton Hall, from which they were taken, contains a series of Rolls of similar accounts of the reign of Edward III. In the belief that the publication of some of these will be useful for purposes of comparison of prices, and as throwing some light on the manner of life of a knightly family in the middle of the fourteenth century, I have selected one of them for description in the present paper.
IV.—The Hauberk of Chain Mail, and its Conventional Representations
Authors: Waller J.G.
Published: November 2011

The subject I now bring before you is by no means a new one; so it is not my intention to go too much over ground already occupied. But the numerous conventional forms by which chain mail has been represented have led to many errors of interpretation, and especially in the articles by Sir Samuel Meyrick in Archaeologia, which are still quoted as authorities, so that I have long felt it was required for that accuracy which is now looked for in all antiquarian studies, that the subject should be revived and discussed. I have had the matter before me for half a century, so cannot therefore be accused of too much hurry in inflicting upon you that which might be thought unnecessary. I should have hesitated in my early days to oppose myself to so high an authority as Meyrick, whose learning and research had done so much to place the history of armour on a firmer basis than it ever had been before, but it was not until I had studied monumental effigies, brasses, and medieval manuscripts that I felt there was considerable doubt as to many of his conclusions. Yet it must here be noted that he himself frequently expresses the same doubts. I think it due to him to mention this, especially as having been personally acquainted with him and enjoyed his hospitality, when I am now about to assail his arguments in the articles referred to, even to removing the terms given from the history of armour.
III.—Wall Paintings in the Infirmary Chapel, Canterbury Cathedral
Authors: Caröe W. D.
Published: November 2011

Professor Willis's plan in his Architectural History of the Monastery of Christ Church lays down very clearly the form of the Capella Infirmorum and its relation t o the Domus Infirmorum and surrounding buildings. The chapel was of late Norman construction, and consisted of a short nave and aisles of four bays, with a square-ended chancel. The nave has a characteristic Norman clearstory, and was separated from the chancel by a chancel arch, but the main features of the nave exist in situ for any one to examine, and need not detain us. The chancel was lighted by two Norman windows on each side, which were shafted, had late Norman, almost Transitional, carved capitals and a rich zigzagged archivolt. In the east wall were three windows of similar detail. The normal thickness of the chancel walls is ft. 2 in. They were unbuttressed, and the whole was ceiled with a plain barrel vault, covering a span of 26 ft, somewhat wide for so small a building.
XII.—An Anglo-Saxon Cemetery at Bidford-on-Avon, Warwickshire: Second Report on the Excavations
Authors: Humphreys John , Ryland J.W. , Wellstood F.C. , Barnard E.A.B. , Barnett T.G.
Published: November 2011

The further examination of the site in the meadow at Bidford-on-Avon, belonging to the Bidford Co-operative Society, and the adjoining garden, the property of the Stratford-on-Avon Brewery Company, was carefully carried out during the summer of 1923. The survey plan (pl. LIX) made by Mr. Wellstood shows the direction of the trenches, and the position of each interment.
IV. Flint Arrow-heads in Britain
Authors: Smith Reginald A.
Published: November 2011

By examining those arrow-heads which are known to have been found in strict association with typical objects and by ignoring those from the material of barrows or from the surface of ploughed fields, it should be possible to classify the series and to establish the successive changes in an article of common use during the later Stone and Bronze Ages of Britain. Only brief references to continental work on the subject will be necessary to enable comparisons to be made, to trace possible lines of communication, and to reach some measure of agreement as to chronology.
IX—Excavations at Chun Castle, in Penwith, Cornwall
Authors: Leeds E. Thurlow
Published: November 2011

Chun, Ch'un, Chyoon, or Chywoon, as it is variously spelt, is the most remarkable of all the Cornish hill-castles. It is tempting to derive the name from the castle itself (Chy-oon, house on the moor), and, if that is legitimate, in Borlase's day, when the inner walls still stood 15 ft. high and more, the name was very apt. The ‘oon’ portion of the name is still present in the adjacent Woon Gumpus Common. Like Trencrom in Lelant, however, the castle probably took its name from the farm on which it stands.
XII.—The Great Astrolabe and other Scientific Instruments of Humphrey Cole
Authors: Gunther R.T.
Published: November 2011

The recent discovery of the finest known example of an English Astrolabe of the largest size, signed by the Elizabethan maker, Humphrey Cole of London, has afforded an opportunity of gathering together some notes on all instruments now known to have been made by him, and of setting forth the chief biographical details of his life. The result shows that he must be regarded as the leading English scientific instrument maker of his century.
Analyticity of solutions to a multidimensional moving boundary problem modelling tumour growth
Authors: Zhou Fujun , Wu Junde
Published: November 2011

We consider the regularity of solutions to a multidimensional moving boundary problem modelling the growth of non-necrotic solid tumours. The model equations include two elliptic equations describing the concentration of a nutrient and the distribution of the internal pressure within the tumour, respectively, and a first-order partial differential equation governing the evolution of the moving boundary on which surface tension effects counteract the internal pressure. On account of the moving boundary and surface tension effects, this problem is a nonlinear problem involving non-local terms. By employing the functional analytic method and the theory of maximal regularity, we prove that the moving boundary is real analytic in temporal and spatial variables, even if the given initial data admit less regularity.
Right pulmonary artery to left atrial fistula: a description of two cases, emphasising a diagnostic approach
Authors: Diaz Gabriel , Marquez Alicia , Gentile Javier
Published: November 2011

Right pulmonary artery to left atrial fistula is a rare pathology characterised by a right to left shunt. Another important aspect of this pathology is the difficulty encountered in making a diagnosis, which is why the diagnosis is frequently delayed into adulthood. A description of two cases is used to emphasise the importance of the different modes of echocardiography as a diagnostic tool in diagnosis, as well as the two different clinical forms that it adopts: a group of patients suffering cardiac failure and cyanosis without apparent cause generally in neonates and a second group of mostly older patients with dyspnoea and cyanosis without apparent cause. Symptoms thus differ depending on the time of presentation and are related to the size of the fistula.
Oceanic controls on the mass balance of Wilkins Ice Shelf, Antarctica
Authors: Padman Laurie , Costa Daniel P. , Dinniman Michael S. , Fricker Helen A. , Goebel Michael E. , Huckstadt Luis A. , Humbert Angelika , Joughin Ian , Lenaerts Jan T. M. , Ligtenberg Stefan R. M. , Scambos Ted , van den Broeke Michiel R.
Published: November 2011

Several Antarctic Peninsula (AP) ice shelves have lost significant fractions of their volume over the past decades, coincident with rapid regional climate change. Wilkins Ice Shelf (WIS), on the western side of the AP, is the most recent, experiencing a sequence of large calving events in 2008 and 2009. We analyze the mass balance for WIS for the period 1992−2008 and find that the averaged rate of ice‐shelf thinning was ∼0.8 m a−1, driven by a mean basal melt rate of 〈wb〉 = 1.3 ± 0.4 m a−1. Interannual variability was large, associated with changes in both surface mass accumulation and 〈wb〉. Basal melt rate declined significantly around 2000 from 1.8 ± 0.4 m a−1for 1992–2000 to ∼0.75 ± 0.55 m a−1for 2001–2008; the latter value corresponding to approximately steady‐state ice‐shelf mass. Observations of ocean temperatureTobtained during 2007–2009 by instrumented seals reveal a cold, deep halo of Winter Water (WW;T≈ −1.6°C) surrounding WIS. The base of the WW in the halo is ∼170 m, approximately the mean ice draft for WIS. We hypothesize that the transition in 〈wb〉 in 2000 was caused by a small perturbation (∼10–20 m) in the relative depths of the ice base and the bottom of the WW layer in the halo. We conclude that basal melting of thin ice shelves like WIS is very sensitive to upper‐ocean and coastal processes that act on shorter time and space scales than those affecting basal melting of thicker West Antarctic ice shelves such as George VI and Pine Island Glacier.
Coastal sea level rise in southern Europe and the nonclimate contribution of vertical land motion
Authors: Wöppelmann G. , Marcos M.
Published: November 2011

In this study, we extend the advanced approach of combining tide gauge and satellite altimetry data with supplemental equations from adjacent tide gauge records of at least 30 years of common data to investigate the relative importance of the nonclimate contribution of vertical land movement to the observed rates of sea level change along the coasts of southern Europe. The sensitivity tests proved that the advanced approach is robust and accurate at the submillimeter per year level of around 0.4 mm yr−1in estimating rates of vertical land movements. It enabled identifying stations displaying large rates of vertical land movements that must be taken into account when predicting future sea level rise and appraising the exposure to its impacts on populations and assets. The average rate of coastal climate‐related sea level rise in the Mediterranean Sea was consequently revisited to be of 1.7 mm yr−1 over the past century, whereas the Atlantic northern Iberian coast revealed a significant high rate of sea level rise in excess of 3.4 mm yr−1 for the past 70 years. Future work should consider applying this powerful approach to other geographic contexts as a useful source of supplementary data for geodynamic studies.
Georadar‐derived estimates of firn density in the percolation zone, western Greenland ice sheet
Authors: Brown Joel , Bradford John , Harper Joel , Pfeffer W. Tad , Humphrey Neil , Mosley‐Thompson Ellen
Published: November 2011

Greater understanding of variations in firn densification is needed to distinguish between dynamic and melt‐driven elevation changes on the Greenland ice sheet. This is especially true in Greenland's percolation zone, where firn density profiles are poorly documented because few ice cores are extracted in regions with surface melt. We used georadar to investigate firn density variations with depth along a ∼70 km transect through a portion of the accumulation area in western Greenland that partially melts. We estimated electromagnetic wave velocity by inverting reflection traveltimes picked from common midpoint gathers. We followed a procedure designed to find the simplest velocity versus depth model that describes the data within estimated uncertainty. On the basis of the velocities, we estimated 13 depth‐density profiles of the upper 80 m using a petrophysical model based on the complex refractive index method equation. At the highest elevation site, our density profile is consistent with nearby core data acquired in the same year. Our profiles at the six highest elevation sites match an empirically based densification model for dry firn, indicating relatively minor amounts of water infiltration and densification by melt and refreeze in this higher region of the percolation zone. At the four lowest elevation sites our profiles reach ice densities at substantially shallower depths, implying considerable meltwater infiltration and ice layer development in this lower region of the percolation zone. The separation between these two regions is 8 km and spans 60 m of elevation, which suggests that the balance between dry‐firn and melt‐induced densification processes is sensitive to minor changes in melt.
Pan‐Arctic simulation of coupled nutrient‐sulfur cycling due to sea ice biology: Preliminary results
Authors: Elliott S. , Deal C. , Humphries G. , Hunke E. , Jeffery N. , Jin M. , Levasseur M. , Stefels J.
Published: November 2011

A dynamic model is constructed for interactive silicon, nitrogen, sulfur processing in and below Arctic sea ice, by ecosystems residing in the lower few centimeters of the distributed pack. A biogeochemically active bottom layer supporting sources/sinks for the pennate diatoms is appended to thickness categories of a global sea ice code. Nutrients transfer from the ocean mixed layer to drive algal growth, while sulfur metabolites are reinjected from the ice interface. Freeze, flux, flush and melt processes are linked to multielement geocycling for the entire high‐latitude regime. Major element kinetics are optimized initially to reproduce chlorophyll observations, which extend across the seasons. Principal influences on biomass are solute exchange velocity at the solid interface, optical averaging in active ice and cell retention against ablation. The sulfur mechanism encompasses open water features such as accumulation of particulate dimethyl sulfoniopropionate, grazing and other disruptive releases, plus bacterial/enzymatic conversion to volatile dimethyl sulfide. For baseline settings, the mixed layer trace gas distribution matches sparging measurements where they are available. However, concentrations rise to well over 10 nM in remote, unsampled locations. Peak contributions are supported by ice grazing, mortality and fractional melting. The model bottom layer adds substantially to a ring maximum of reduced sulfur chemistry that may be dominant across the marginal Arctic environment. Sensitivity tests on this scenario include variation of cell sulfur composition and remineralization, routings/chemical time scales, and the physical dimension of water layers. An alternate possibility that peripheral additions are small cannot be excluded from the outcomes. It is concluded that seagoing dimethyl sulfide data are far too sparse at the present time to distinguish sulfur‐ice production levels.
Kollidon VA64, a Membrane-Resealing Agent, Reduces Histopathology and Improves Functional Outcome after Controlled Cortical Impact in Mice
Authors: Mbye Lamin H , Keles Eyup , Tao Luyang , Zhang Jimmy , Chung Joonyong , Larvie Mykol , Koppula Rajani , Lo Eng H , Whalen Michael J
Published: November 2011

Loss of plasma membrane integrity is a feature of acute cellular injury/death in vitro and in vivo. Plasmalemma-resealing agents are protective in acute central nervous system injury models, but their ability to reseal cell membranes in vivo has not been reported. Using a mouse controlled cortical impact (CCI) model, we found that propidium iodide-positive (PI+) cells pulse labeled at 6, 24, or 48 hours maintained a degenerative phenotype and disappeared from the injured brain by 7 days, suggesting that plasmalemma permeability is a biomarker of fatal cellular injury after CCI. Intravenous or intracerebroventricular administration of Kollidon VA64, poloxamer P188, or polyethylene glycol 8000 resealed injured cell membranes in vivo ( P<0.05 versus vehicle or poloxamer P407). Kollidon VA64 (1 mmol/L, 500 μL) administered intravenously to mice 1 hour after CCI significantly reduced acute cellular degeneration, chronic brain tissue damage, brain edema, blood—brain barrier damage, and postinjury motor deficits (all P<0.05 versus vehicle). However, VA64 did not rescue pulse-labeled PI+ cells from eventual demise. We conclude that PI permeability within 48 hours of CCI is a biomarker of eventual cell death/loss. Kollidon VA64 reduces secondary damage after CCI by mechanisms other than or in addition to resealing permeable cells.
NADPH oxidase is involved in H2O2‐induced differentiation of human promyelocytic leukaemia HL‐60 cells
Authors: Lin Changjun , Wang Huan
Published: November 2011

The expression and activity of NADPH oxidase increase when HL‐60 cells are induced into terminally differentiated cells. However, the function of NADPH oxidase in differentiation is not well elucidated. With 150–500 μM H2O2 inducing differentiation of HL‐60 cells, we measured phagocytosis of latex beads and investigated cell electrophoresis. Two inhibitors of NADPH oxidase, DPI (diphenyleneiodonium) and APO (apocynin), blocked the differentiation potential of cells induced by 200 μM H2O2. However, H2O2 stimulated the generation of intracellular superoxide (O2•−), which decreased in the presence of the two inhibitors. DPI also inhibited H2O2‐induced ERK (extracellular‐signal‐regulated kinase) activation, as detected by Western blotting. Furthermore, PD98059, the inhibitor of the ERK pathway, inhibited the differentiation of HL‐60 cells induced by H2O2. This shows that H2O2 can activate NADPH oxidase, leading to O2•− production, followed by ERK activation and ultimately resulting in the differentiation of HL‐60 cells. The data indicate that NADPH oxidase is an important cell signal regulating cell differentiation.
Influence of the interface on growth rates in AlN/GaN short period superlattices via metal organic vapor phase epitaxy
Authors: Rodak L. E. , Korakakis D.
Published: November 2011

AlN/GaN short period superlattices are well suited for a number of applications including, but not limited to, digital alloys, intersubband devices, and emitters. In this work, AlN/GaN superlattices with periodicities ranging from 10 to 20 Å have been grown via metal organic vapor phase epitaxy in order to investigate the influence of the interface on the binary alloy growth rates. The GaN growth rate at the interface was observed to decrease with increasing GaN thickness while the AlN growth rate remained constant. This has been attributed to a decrease in the decomposition rate of GaN at the hetero-interface as seen in other III-V hetero-structures.
Three-dimensional real-time imaging of bi-phasic flow through porous media
Authors: Sharma Prerna , Aswathi P. , Sane Anit , Ghosh Shankar , Bhattacharya S.
Published: November 2011

We present a scanning laser-sheet video imaging technique to image bi-phasic flow in three-dimensional porous media in real time with pore-scale spatial resolution, i.e., 35 μm and 500 μm for directions parallel and perpendicular to the flow, respectively. The technique is illustrated for the case of viscous fingering. Using suitable image processing protocols, both the morphology and the movement of the two-fluid interface, were quantitatively estimated. Furthermore, a macroscopic parameter such as the displacement efficiency obtained from a microscopic (pore-scale) analysis demonstrates the versatility and usefulness of the method.
Observing metamaterial induced transparency in individual Fano resonators with broken symmetry
Authors: Singh Ranjan , Al-Naib Ibraheem A. I. , Yang Yuping , Roy Chowdhury Dibakar , Cao Wei , Rockstuhl Carsten , Ozaki Tsuneyuki , Morandotti Roberto , Zhang Weili
Published: November 2011

Metamaterial induced transparency is demonstrated using individual split ring resonators with two gaps on opposite side. For the symmetric structure, only a low quality dipolar resonance is witnessed at a normal incidence excited with electric field along the resonator gaps. Displacement of one gap from the centre breaks the symmetry and a higher order mode, inaccessible in the symmetric structure, is excited. Coherent interaction among the modes in the split ring resonator forms an extremely sharp narrowband transparency window centred directly at the dipole resonance. Such metamaterial could facilitate coherent manipulation of terahertz signals for delay, storage, and nonlinear applications.
Dielectric model of point charge defects in insulating paraelectric perovskites
Authors: Buniatian V. , Martirosyan N. , Vorobiev A. , Gevorgian S.
Published: November 2011

Some point defects (i.e., oxygen vacancies) create deep trapping levels in the bandgap of the paraelectric phase ferroelectric crystals. Under applied DC field the traps release electrons via the Poole-Frenkel mechanism and become charged. The electric field of a point charge polarizes the crystal locally reducing its permittivity. In this paper a simple theory is proposed for calculating the DC field dependent apparent (measureable) permittivity of a paraelectric crystal with point charge defects. It is shown that the apparent permittivity of a paraelectric crystal may be sufficiently lower as compared with the defectless crystal. This reduction is in addition to the possible reduction of the apparent permittivity associated with the interfacial “dead” layers and strain.
Effects of surface tension and axis stress on piezoelectric behaviors of ferroelectric nanowires
Authors: Chen Y. Q. , En Y. F. , Huang Y. , Kong X. D. , Zheng X. J. , Lu Y. D.
Published: November 2011

The effects of surface tension and axis stress on piezoelectric behaviors of ferroelectric nanowires with radius polarization were investigated by the time-dependent Ginzburg-Landau theory. When surface tension increases, both of coercive field and remnant strain decrease. The larger the surface tension is, the more they decrease. The axis compressive stress enhances the coercive field and remnant strain, while the axis tensile stress has contrary effect. The reason for the stress-modulated piezoelectricity is that radius polarization is forced by axis compressive stress but restrained by surface tension and axis tensile stress. The research is useful for ferroelectric nanostructures in strain engineering.
Single walled carbon nano-tube, ferroelectric liquid crystal composites: Excellent diffractive tool
Authors: Srivastava A. K. , Pozhidaev E. P. , Chigrinov V. G. , Manohar R.
Published: November 2011

We present a switchable grating based on chiral single walled carbon nano-tube (SWCNT) doped ferroelectric liquid crystals (FLCs). The presence of SWCNTs improves the diffraction profile of the pure FLC. The diffraction efficiency, i.e., the ratio of intensities of first order and zero order maxima is more than 100% for the higher concentration of SWCNTs in pure FLC. This phenomenon has been explained by the decrease in ferroelectric domain periodicity, due to the doping of SWCNTs in pure FLC, and optical activity of the chiral SWCNTs. These gratings with very high diffraction efficiency may find application in many devices.
Magnetism of ultrathin Fe films on MgO(001)
Authors: Yang Seolun , Park H.-K. , Kim J.-S. , Kim J.-Y. , Park B.-G.
Published: November 2011

We grow ultrathin (<2-monolayer (ML)) Fe films on MgO(001) at 80 K, limiting oxide formation to the very early stages of Fe growth, and then investigate in situ the magnetism of the films using x-ray magnetic circular dichroism (XMCD). The 0.2-ML-thick Fe film exhibits superparamagnetism, disproving the existence of a magnetically dead layer. For all the films, the spin moments per Fe atom are far less than that of bulk Fe, while anomalously large orbital moments are observed. Those are attributed, respectively, to both the oxidation Fe film at the interface and the existence of some Fe nanoclusters in fcc phase and to the high population of low coordinated atoms, such as Fe at the edges of the nanoclusters.
Reversible Oregonator model revisited: Thermodynamic validity
Authors: Dutt Arun K.
Published: November 2011

We have investigated the features of thermodynamic equilibrium state of the reversible Oregonator (RO) model with close system approximation for a plausible stoichiometry, in which there is no overall change in the concentrations of the intermediates. For Field-Försterling (ff) parameters, this model with close system approximation attains the state of thermodynamic equilibrium at equilibrium concentration of its final product in the order of 104 mol l-1, which is obviously unrealistic in a laboratory experiment. From numerical experiment, we report that if the equilibrium constant of the fifth step (K5) is assigned a value less than 1.0 (which is opposite to that proposed by Field), the RO model under open system approximation could execute oscillations, as well as under close system approximation could evolve to a thermodynamic equilibrium state with reasonably low and realistic equilibrium concentration of its final product for the overall reaction considered here. To accommodate the findings of this numerical work for the RO kinetic steps with K5 <1, we have found it necessary to revise the 2-variable diffusion-reaction model of Tyson.
The cardiopulmonary haemodynamic transition at birth is not different between male and female preterm lambs
Authors: Polglase Graeme R. , Hooper Stuart B. , Kluckow Martin , Gill Andrew W. , Harding Richard , Moss Timothy J. M.
Published: November 2011

Males born preterm are at greater risk of illness and death than females, principally due to respiratory disease. Much of the excess morbidity occurs within the first few hours of life. Therefore, the aim of the present study was to investigate whether or not differences in the cardiopulmonary transition soon after birth underlie the increased morbidity in males after preterm birth. Nine female and thirteen male lambs (128 ± 2 days gestation) underwent surgery immediately before delivery for implantation of a pulmonary arterial flow-probe and catheters into the main pulmonary artery and a carotid artery. After birth lambs were ventilated for 30 min (tidal volume 7 mL kg–1) while anaesthetised. Arterial pressures and flows were recorded in real time and left-ventricular output measured using Doppler echocardiography. Before birth, fetal cardiopulmonary haemodynamics, arterial blood gases, pH, glucose and lactate did not differ between sexes. Similarly, in the neonatal period there were no significant differences in arterial blood gas status, ventilation parameters, respiratory indices or cardiopulmonary haemodynamics between the sexes. Our data show that the cardiopulmonary transition at birth in ventilated, anaesthetised preterm lambs is not influenced by sex. Thus, the neonatal ‘male disadvantage’ is not explained by an impaired cardiovascular transition at birth.
The oviducal protein, heat-shock 70-kDa protein 8, improves the long-term survival of ram spermatozoa during storage at 17°C in a commercial extender
Authors: Lloyd R. E. , Fazeli A. , Watson P. F. , Holt W. V.
Published: November 2011

Poor fertility rates are often observed when fresh ram semen stored in conventional extenders is used for cervical artificial insemination (AI). Heat-shock 70-kDa protein 8 (HSPA8), found within the oviduct, prolongs boar, ram and bull sperm survival at body temperatures in vitro. Here, we aimed to determine whether supplementing extenders (INRA-96 and RSD-1) with HSPA8 (4 µg mL–1) would improve their performance in maintaining freshly collected ram sperm viability and sperm nuclear DNA integrity during storage over 48 h at 17°C. Sperm function was assessed at 1, 6, 24 and 48 h and this experiment was repeated using 25 × 106 and 800 × 106 spermatozoa mL–1. INRA96 supplemented with HSPA8 maintained sperm viability significantly better than INRA96 alone at both sperm concentrations. However, sperm nuclear DNA fragmentation (DF) increased significantly during storage using the higher sperm concentration, irrespective of the extender and the protein treatment used. Increasing levels of sperm nuclear DF over time could explain why poor fertility rates are often observed following cervical AI using stored ram semen. However, further research is required to ascertain whether supplementing the commercially available INRA96 extender with HSPA8 will improve fertility rates following cervical AI using stored ram semen.
Phenotypic Variation Within a Clonal Lineage of Phytophthora infestans Infecting both Tomato and Potato in Nicaragua
Authors: Blandón-Díaz J. U. , Widmark A.-K. , Hannukkala A. , Andersson B. , Högberg N. , Yuen J. E.
Published: November 2011

Late blight caused by Phytophthora infestans (Mont.) de Bary is a constraint to both potato and tomato crops in Nicaragua. The hypothesis that the Nicaraguan population of P. infestans is genotypically and phenotypically diverse and potentially subdivided based on host association was tested. A collection of isolates was analyzed using genotypic markers (microsatellites and mitochondrial DNA haplotype) and phenotypic markers (mating type, virulence, and fungicide sensitivity). The genotypic analysis revealed no polymorphism in 121 of 132 isolates of P. infestans tested. Only the Ia haplotype and the A2 mating type were detected. Most of the tested isolates were resistant to metalaxyl. The virulence testing showed variation among isolates of P. infestans. No evidence was found of population differentiation among potato and tomato isolates of P. infestans based on the genotypic and phenotypic analysis. We conclude that the Nicaraguan population of P. infestans consists of a single clonal lineage (NI-1) which belongs to the A2 mating type and the Ia mitochondrial DNA haplotype. Moreover, based on the markers used, this population of P. infestans does not resemble the population in countries from which potato seed is imported to Nicaragua or the population in neighboring countries. The data presented here indicate that the NI-1 clonal lineage is the primary pathogen on both potato and tomato, and its success on both host species is unique in a South American context.
Heart Rate Variability in Complex Regional Pain Syndrome during Rest and Mental and Orthostatic Stress
Authors: Terkelsen Astrid J. , Mølgaard Henning , Hansen John , Finnerup Nanna B. , Krøner Karsten , Jensen Troels S.
Published: November 2011

Background

Complex regional pain syndrome (CRPS) is a pain condition with regional sensory and autonomic abnormalities in the affected limb. The authors studied systemic autonomic and hemodynamic function in CRPS patients during rest, and during orthostatic and mental arithmetic stress.

Methods

Twenty patients with CRPS and 20 age-, sex-, and body mass index-matched control subjects participated. Mean values of heart rate variability, baroreceptor sensitivity, blood pressure, stroke volume, cardiac output, and total peripheral resistance were estimated during supine rest and 60° tilt-table testing. On a separate day, heart rate variability was also measured during mental arithmetic stress testing induced by a paced auditory serial addition task.

Results

Heart rate was increased and heart rate variability reduced in patients with CRPS patients compared with control subjects during rest and mental and orthostatic stress, whereas baroreceptor sensitivity was unaffected. When tilted from supine to upright position, patients with CRPS were not able to preserve cardiac output in comparison with control subjects, and they exhibited an exaggerated increase in the total peripheral resistance. The hemodynamic changes correlated to pain duration but not to pain intensity.

Conclusion

The increased heart rate and decreased heart rate variability in CRPS suggest a general autonomic imbalance, which is an independent predictor for increased mortality and sudden death. The inability of the patients to protect their cardiac output during orthostatic stress was aggravated with the chronicity of the disease.
The cellular mechanisms of memory are modified by experience
Authors: Wiltgen Brian J. , Wood Alynda N. , Levy Brynne
Published: November 2011

The N-methyl-D-aspartate receptor (NMDAR) is thought to be essential for synaptic plasticity and learning. However, recent work indicates that the role of this receptor depends on the prior history of the research subject. For example, animals trained on a hippocampus-dependent learning task are subsequently able to acquire new information in the absence of NMDAR activation. The current experiments were designed to identify the types of experiences that lead to NMDAR-independent learning. Using contextual fear conditioning in mice, we find that NMDAR-independent learning is only observed when (1) animals are trained on the same behavioral task and (2) initial learning is successfully encoded into long-term memory.
The Psb27 Assembly Factor Binds to the CP43 Complex of Photosystem II in the Cyanobacterium Synechocystis sp. PCC 6803
Authors: Komenda Josef , Knoppová Jana , Kopečná Jana , Sobotka Roman , Halada Petr , Yu Jianfeng , Nickelsen Joerg , Boehm Marko , Nixon Peter J.
Published: November 2011

We have investigated the location of the Psb27 protein and its role in photosystem (PS) II biogenesis in the cyanobacterium Synechocystis sp. PCC 6803. Native gel electrophoresis revealed that Psb27 was present mainly in monomeric PSII core complexes but also in smaller amounts in dimeric PSII core complexes, in large PSII supercomplexes, and in the unassembled protein fraction. We conclude from analysis of assembly mutants and isolated histidine-tagged PSII subcomplexes that Psb27 associates with the “unassembled” CP43 complex, as well as with larger complexes containing CP43, possibly in the vicinity of the large lumenal loop connecting transmembrane helices 5 and 6 of CP43. A functional role for Psb27 in the biogenesis of CP43 is supported by the decreased accumulation and enhanced fragmentation of unassembled CP43 after inactivation of the psb27 gene in a mutant lacking CP47. Unexpectedly, in strains unable to assemble PSII, a small amount of Psb27 comigrated with monomeric and trimeric PSI complexes upon native gel electrophoresis, and Psb27 could be copurified with histidine-tagged PSI isolated from the wild type. Yeast two-hybrid assays suggested an interaction of Psb27 with the PsaB protein of PSI. Pull-down experiments also supported an interaction between CP43 and PSI. Deletion of psb27 did not have drastic effects on PSII assembly and repair but did compromise short-term acclimation to high light. The tentative interaction of Psb27 and CP43 with PSI raises the possibility that PSI might play a previously unrecognized role in the biogenesis/repair of PSII.
The Role of CAX1 and CAX3 in Elemental Distribution and Abundance in Arabidopsis Seed
Authors: Punshon Tracy , Hirschi Kendal , Yang Jian , Lanzirotti Antonio , Lai Barry , Guerinot Mary Lou
Published: November 2011

The ability to alter nutrient partitioning within plants cells is poorly understood. In Arabidopsis (Arabidopsis thaliana), a family of endomembrane cation exchangers (CAXs) transports Ca2+ and other cations. However, experiments have not focused on how the distribution and partitioning of calcium (Ca) and other elements within seeds are altered by perturbed CAX activity. Here, we investigate Ca distribution and abundance in Arabidopsis seed from cax1 and cax3 loss-of-function lines and lines expressing deregulated CAX1 using synchrotron x-ray fluorescence microscopy. We conducted 7- to 10-μm resolution in vivo x-ray microtomography on dry mature seed and 0.2-μm resolution x-ray microscopy on embryos from lines overexpressing deregulated CAX1 (35S-sCAX1) and cax1cax3 double mutants only. Tomograms showed an increased concentration of Ca in both the seed coat and the embryo in cax1, cax3, and cax1cax3 lines compared with the wild type. High-resolution elemental images of the mutants showed that perturbed CAX activity altered Ca partitioning within cells, reducing Ca partitioning into organelles and/or increasing Ca in the cytosol and abolishing tissue-level Ca gradients. In comparison with traditional volume-averaged metal analysis, which confirmed subtle changes in seed elemental composition, the collection of spatially resolved data at varying resolutions provides insight into the impact of altered CAX activity on seed metal distribution and indicates a cell type-specific function of CAX1 and CAX3 in partitioning Ca into organelles. This work highlights a powerful technology for inferring transport function and quantifying nutrient changes.
Measuring flow experience in an immersive virtual environment for collaborative learning
Authors: van Schaik P. , Martin S. , Vallance M.
Published: November 2011

In contexts other than immersive virtual environments, theoretical and empirical work has identified flow experience as a major factor in learning and human–computer interaction. Flow is defined as a ‘holistic sensation that people feel when they act with total involvement’. We applied the concept of flow to modeling the experience of collaborative learning in an immersive virtual environment. The aims were, first, to psychometrically evaluate a measurement model of flow and, second, to test a structural model of flow. Pairs of small teams engaged in collaborative problem‐solving tasks while communicating by way of an immersive virtual environment. Flow was measured after each session, using Guo and Poole's inventory for measuring flow in human–computer interaction. In relation to the first aim, partial‐least‐squares analysis demonstrated strong evidence for the measurement model. In relation to the second aim, the structural model was supported: the effect of learning‐task characteristics on flow experience was mediated by its precursors, with extraneous variables held constant. It is reasoned that the experiment and resultant analysis of this work contributes to the development of measurement models and structural models of flow in immersive virtual environments.
Cryo‐EM—the first thirty years
Authors: DUBOCHET J.
Published: November 2011

Thirty years ago, in December 1981, The Journal of Microscopy published a very short paper entitled ‘Vitrification of pure water for electron microscopy’. It turned out to be important for the development of cryo‐electron microscopy and it contributed to reverse, from foe to friend, the status of water in electron microscopists’ minds. This change has brought obvious gains. The future will tell how many more are still to come.