bluuebunny/crossref_metadata_2025 huggingface dataset:
The Obesity-AssociatedFTOGene Encodes a 2-Oxoglutarate-Dependent Nucleic Acid Demethylase
Authors: Gerken Thomas , Girard Christophe A. , Tung Yi-Chun Loraine , Webby Celia J. , Saudek Vladimir , Hewitson Kirsty S. , Yeo Giles S. H. , McDonough Michael A. , Cunliffe Sharon , McNeill Luke A. , Galvanovskis Juris , Rorsman Patrik , Robins Peter , Prieur Xavier , Coll Anthony P. , Ma Marcella , Jovanovic Zorica , Farooqi I. Sadaf , Sedgwick Barbara , Barroso Inês , Lindahl Tomas , Ponting Chris P. , Ashcroft Frances M. , O'Rahilly Stephen , Schofield Christopher J.
Published: November 2007

Variants in theFTO(fat mass and obesity associated) gene are associated with increased body mass index in humans. Here, we show by bioinformatics analysis that FTO shares sequence motifs with Fe(II)- and 2-oxoglutarate–dependent oxygenases. We find that recombinant murine Fto catalyzes the Fe(II)- and 2OG-dependent demethylation of 3-methylthymine in single-stranded DNA, with concomitant production of succinate, formaldehyde, and carbon dioxide. Consistent with a potential role in nucleic acid demethylation, Fto localizes to the nucleus in transfected cells. Studies of wild-type mice indicate thatFtomessenger RNA (mRNA) is most abundant in the brain, particularly in hypothalamic nuclei governing energy balance, and thatFtomRNA levels in the arcuate nucleus are regulated by feeding and fasting. Studies can now be directed toward determining the physiologically relevant FTO substrate and how nucleic acid methylation status is linked to increased fat mass.
c-Jun NH2-Terminal Kinase 2 Inhibits Gamma Interferon Production duringAnaplasma phagocytophilumInfection
Authors: Pedra Joao H. F. , Mattner Jochen , Tao Jian , Kerfoot Steven M. , Davis Roger J. , Flavell Richard A. , Askenase Philip W. , Yin Zhinan , Fikrig Erol
Published: November 2007

Gamma interferon (IFN-γ) plays a critical role in the early eradication ofAnaplasma phagocytophilum. However, the mechanisms that regulate IFN-γ production upon infection remain poorly understood. Here we show that c-Jun NH2-terminal kinase 2 (JNK2) inhibits IFN-γ production duringA. phagocytophiluminfection.jnk2-null mice were more refractory to infection withA. phagocytophilumand produced increased levels of IFN-γ after challenge with the pathogen. The resistance ofjnk2-null mice toA. phagocytophiluminfection was due to elevated levels of IFN-γ secreted by conventional and natural killer (NK) T cells. The administration of α-galactosylceramide, a strong NK T-cell agonist, increased IFN-γ release and protected mice fromA. phagocytophilum, further demonstrating the inhibitory effect of JNK2 on IFN-γ production. Collectively, these findings provide strong evidence that JNK2 is an important regulatory protein for IFN-γ secretion upon challenge withA. phagocytophilum.
Effects of CXCL10 on Dendritic Cell and CD4+T-Cell Functions duringLeishmania amazonensisInfection
Authors: Vasquez René E. , Xin Lijun , Soong Lynn
Published: November 2007

Leishmania amazonensiscan cause progressive disease in most inbred strains of mice. We have previously reported that treatment with CXCL10 activates macrophage (MΦ) effector function(s) in parasite killing and significantly delays lesion development in susceptible C57BL/6 mice via enhanced gamma interferon (IFN-γ) and interleukin 12 (IL-12) secretion; however, the mechanism underlying this enhanced immunity againstL. amazonensisinfection remains largely unresolved. In this study, we utilized stationary promastigotes to infect bone marrow-derived dendritic cells (DCs) of C57BL/6 mice and assessed the activation of DC subsets and the capacity of these DC subsets to prime CD4+T cells in vitro. We found that CXCL10 induced IL-12 p40 production but reduced IL-10 production in uninfected DCs. YetL. amazonensis-infected DCs produced elevated levels of IL-10 despite CXCL10 treatment. Elimination of endogenous IL-10 led to increased IL-12 p40 production in DCs as well as increased proliferation and IFN-γ production by in vitro-primed CD4+T cells. In addition, CXCL10-treated CD4+T cells became more responsive to IL-12 via increased expression of the IL-12 receptor β2chain and produced elevated levels of IFN-γ. This report indicates the utility of CXCL10 in generating a Th1-favored, proinflammatory response, which is a prerequisite for controllingLeishmaniainfection.
Reductive Dimerization of 2- and 6-Iodopurines: Side Reaction in Pd-Catalyzed Cross-Coupling of Iodopurines
Authors: Tobrman Tomáš , Dvořák Dalimil
Published: November 2007

In the presence of a Pd catalyst and a base, 6- and 2-iodopurine derivatives undergo reductive C-C dimerization with the formation of the corresponding 6,6'- or 2,2'-dimers. The best results of the dimerization were obtained in the presence of i-Pr2NEt as a base in DMF. Phosphine-free catalysts as well as catalysts containing phosphines can be used. In the presence of catalytic systems containing PPh3 the dimerization does not proceed. This dimerization may become an important side reaction in the Stille or the Suzuki-Miyaura reactions of iodopurines.
EVOLUTIONARY OPTIMIZATION OF SEQUENCE KERNELS FOR DETECTION OF BACTERIAL GENE STARTS
Authors: MERSCH BRITTA , GLASMACHERS TOBIAS , MEINICKE PETER , IGEL CHRISTIAN
Published: November 2007

Oligo kernels for biological sequence classification have a high discriminative power. A new parameterization for the K-mer oligo kernel is presented, where all oligomers of length K are weighted individually. The task specific choice of these parameters increases the classification performance and reveals information about discriminative features. For adapting the multiple kernel parameters based on cross-validation the covariance matrix adaptation evolution strategy is proposed. It is applied to optimize the trimer oligo kernels for the detection of bacterial gene starts. The resulting kernels lead to higher classification rates, and the adapted parameters reveal the importance of particular triplets for classification, for example of those occurring in the Shine-Dalgarno Sequence.
HIGH ENERGY SIGNATURES OF POST ADIABATIC SUPERNOVA REMNANTS
Authors: TELEZHINSKY IGOR , HNATYK BOHDAN
Published: November 2007

Between the well-known adiabatic and radiative stages of the Supernova remnant (SNR) evolution there is, in fact, a transition stage with a duration comparable to the duration of adiabatic one. Physical existence of the transition stage is motivated by cooling of some part of the downstream hot gas with formation of a thin cold shell that is joined to a shell of swept up interstellar medium (ISM). We give an approximate analytical method for full hydrodynamical description of the transition stage. On its base we investigate the evolution of X-ray and γ-ray radiation during this stage. It is shown that formation of a dense shell during the transition stage is accompanied by the decrease of X-ray luminosity because of hot gas cooling and increase of gamma-ray flux according to the increase of target proton density and CR energy in the newly born shell. The role of nonuniformity of ISM and its influence on the high energy fluxes from the SNRs is also discussed.
YANG–MILLS THERMODYNAMICS AT LOW TEMPERATURE
Authors: HOFMANN RALF
Published: November 2007

For the confining phase of SU(2) Yang–Mills thermodynamics, we show that the asymptotic series representing the pressure is Borel summable for negative (unphysical) values of a suitably defined coupling constant. The inverse Borel transform is meromorphic except for a branch cut along the positive-real axis. The physical pressure is precisely nil at vanishing and acquires a small imaginary admixture at small temperature, the latter indicating violations of thermal equilibrium (turbulences).
HOLOGRAPHIC INTERACTING DARK ENERGY IN THE BRANEWORLD COSMOLOGY
Authors: KIM KYOUNG YEE , LEE HYUNG WON , MYUNG YUN SOO
Published: November 2007

We investigate a model of brane cosmology to find a unified description of the radiation-matter-dark energy universe. It is of the interacting holographic dark energy with a bulk-holographic matter χ. This is a five-dimensional cold dark matter, which plays a role of radiation on the brane. Using the effective equations of state [Formula: see text] instead of the native equations of state ωΛ, we show that this model cannot accommodate any transition from the dark energy with [Formula: see text] to the phantom regime [Formula: see text]. Furthermore, the case of interaction between four-dimensional cold dark matter and five-dimensional cold dark matter is considered for completeness. Here we find that the redshift of matter-radiation equality z eq is the same order as [Formula: see text]. Finally, we obtain a general decay rate Γ which is suitable for describing all interactions.
QUANTUM CHEMICAL STUDY OF POLYAROMATIC HYDROCARBONS IN HIGH MULTIPLICITY STATES
Authors: KHAVRYUCHENKO VOLODYMYR D. , TARASENKO YURIJ A. , STRELKO VOLODYMYR V. , KHAVRYUCHENKO OLEKSIY V. , LISNYAK VLADYSLAV V.
Published: November 2007

A study of polyaromatic hydrocarbons by semiempirical PM3 and ab initio methods in MINI and STO 6G-31 bases has been performed for compounds with different numbers of rings. The optimized space and electronic structures have been derived. The multiplicity states effect on the energetic stability of the polyaromatic hydrocarbons is examined. It is shown that the high multiplicity states become more energetically preferable with the growth of the PAH size.
MEASURING SPIN HALL CONDUCTANCE AND RASHBA SPIN–ORBIT INTERACTION VIA ELECTRICAL MEASUREMENT IN Y SHAPE CONDUCTOR
Authors: PAREEK T. P.
Published: November 2007

We propose a multi-terminal (non-magnetic) mesoscopic electrical transport measurement for measuring spin Hall effect and Rashba spin–orbit strength. Our methods use a three terminal mesoscopic device, in which one of the terminals acts as a voltage probe. We show that the charge conductance, spin Hall conductance and voltage measured at the non-magnetic voltage probe depends on the strength of the Rashba spin–orbit interaction.
SEARCHING FOR VIBRATING MODES OF ATOM CHAIN MODELS WITH EXTRA STRINGS BY VIRTUE OF THE INVARIANT EIGEN-OPERATOR METHOD
Authors: WU HAO , FAN HONG-YI
Published: November 2007

We show that the vibration modes of some atom chain models (including diatomic chain) with extra strings can be derived directly by using the newly-developed invariant eigen-operator method. Especially, the chain model which takes different second-neighbor interactions into account is solved.
ENTANGLEMENT IN A HARDCORE BOSON HUBBARD MODEL
Authors: HAO XIANG , ZHU SHIQUN
Published: November 2007

The entanglement in a Hubbard chain of hardcore bosons is investigated. The analytic expression of the global entanglement in the ground state is derived. The divergence of the derivative of the global entanglement shows the quantum criticality of the ground state. For the thermal equilibrium state, the bipartite and the multipartite entanglement are evaluated. The entanglement decreases to zero at a certain temperature. The thermal entanglement is rapidly decreasing with the increase of the number of sites in the lattice. The bipartite thermal entanglement approaches a constant value at a certain number of sites while the multipartite entanglement eventually vanishes.
Site investigations in coalfields—the problem of shallow mine workings
Authors: Taylor R. K.
Published: November 2007

AUTHOR'S REPLY:

I would like to thank Mr Short for his kind remarks and for the historical information relating to ‘bell-pits’ and the interesting troglodyte dwellings at Doncaster which had also been mentioned. The deepest ‘bell-pit’ workings which the writer has seen were in the well-known Tankersley Ironstone overlying the Flockton Thick seam (
Anthraconaia modiolaris
Zone) of the Yorkshire coalfield. Shafts just over 40 ft deep are relatively common and a figure of 70 ft has recently been quoted in the press. Although the measures above the Flockton Thick are reasonably competent it is unlikely from the point of view of stability that this latter figure refers to ‘bell-pits’ in the true sense.

Geophysical techniques in the initial exploratory phase of a site investigation programme may give useful information. Unfortunately present methods do not lend themselves to the detection of ‘room and pillar’ workings, which pose the most uncompromising problems. It seems logical, however, to extend the use of geophysical methods to include later phases of site investigations when more detailed information is required and very close traverses may be warranted. Attention should be drawn to the fact that in recent years instrumentation has made great advances in many fields employing geophysical methods. For some unknown reason this does not include the important field of land-based site investigations.

R. K. Taylor

Engineering Geology Laboratory, Department of Geology, University Science Laboratories, South Road, Durham.
The management of ground water resources in the Republic of Ireland
Authors: Williams Paul W.
Published: November 2007

T
he general state of hydrology
in Ireland has recently been reported on by the National Committee for the International Hydrological Decade. They pointed out that there are many deficiencies in our knowledge of surface and ground water resources and that the important problem of water supply management has been entirely neglected.

No organization has any kind of general hydrological responsibility in Ireland. With virtually no funds or statutory authority the enlightened IHD Committee appears condemned to frustration, being able to achieve little beyond recommendations. Its present role is at best advisory, and there are doubts as to how seriously its suggestions are taken. Surface water, precipitation and evaporation measurements are carried out by various State or Semi-State bodies, including the Office of Public Works, the Electricity Supply Board and the Meteorological Office. With the exception of meteorological data abundant raw data is available, but it is not in a convenient form for retrieval for public use. Nor is staff available to extract the information on file, an intolerable if understandable situation. No systematic observations have been made of ground water in Ireland and no one has been charged with the responsiblity of collecting and processing data, despite the recommendations of the IHD Committee that a Ground Water Division should be established within the Geological Survey. In fact, the Survey has for many years operated a valuable skeleton advisory service on ground water, receiving and distributing information on underground water supplies; but it has never been instructed to do so and
Engineering Group Regional Meeting 1970: Closing Statement
Authors: Knill John Lawrence
Published: November 2007

The Dublin meeting of the Engineering Group of the Geological Society was intended to be a state-of-the-art review of Engineering Geology in the British Isles. After the rapid development of the Group over several years it seemed an opportunity to look both backwards and forwards. There is little doubt that the Group had become successful with a programme of regular meetings and an established Journal. The Group activity might, however, be viewed as reflecting a backlog in the desire for professional expression and the Group should look to the future with care. Therefore, the Dublin meeting took place at a logical and convenient point in time, and it would provide in retrospect a record of thinking in a relaxed atmosphere.

W. R. Dearman, in his opening remarks, gave a definition of Engineering Geology linking the subject clearly to industrial applications of geology viewed in the broad sense. It could however be viewed in an alternative way in that much of the activity of engineering geologists was people-orientated and consequently related to environmental or social geology. This was very clearly illustrated by D. G. Price through his account of the influence of geology in urban development and G. P. Jones in his discussion of management in water use, re-use and waste disposal. In this latter field, the writer dissented from Jones in that hydrogeology formed, to his mind, part of the full spectrum of engineering geology and should not be regarded as a totally independent subject. Hydrogeology is as relevant to
Geological education for undergraduate civil engineers
Authors: Cawsey D. C. , Francis C. M. G.
Published: November 2007

I would like to offer the following comment, for publication.

Most Civil Engineering Departments provide for a service course to be given by a Geology Department early in the civil engineers training with a view to teaching the elements of geology and it is fitting that such a course should be given by a geology department who are best able to introduce their subject. This is geology for engineers, not engineering geology and forms a useful introduction to soil mechanics which should follow.

Applications such as site investigation, problems with dams, water, foundations etc. should be left until late in the course when they can be appreciated and should only be given by those staff members who have some real training or experience in these matters. One is often irked by an attitude sometimes shown by geologists that geology has something to offer civil engineering (which it has) but civil engineering has nothing to offer geology. Until geologists as a part of their training take some courses in soil mechanics, rock mechanics and fluid mechanics, which are available in civil engineering departments we will tend to have geologists who say ‘what do the engineers want?’

I would also deprecate an attitude which regards an engineering geologist as a ‘middle man’, rather engineering geology is a subject in its own right which should develop its own theory and expertise in the same way that soil mechanics has been developed.

In conclusion the paper is interesting as it shows an awareness of
The hydrogeological investigation of fissure flow by borehole logging techniques
Authors: Tate A. K. , Robertson A. S. , Gray D. A.
Published: November 2007

The variety and sophistication of the equipment which the authors have at their disposal are impressive, as are the data obtained and the conclusions reached.

It is opportune, however, to acquaint readers with an additional tool in the armoury of the hydrogeologist: radio active tracers.

In Rhodesia the majority of boreholes are sited in the crystalline rocks (granites, gneisses and the highly metamorphosed volcanics and sedimentary rocks of the Basement Complex) where the aquifer consists of fissured or decomposed rock.

The delineation of fissures and zones of flow and the estimation of natural through-flow is, at times, of considerable importance.
Radio active tracer in the form of Iodine 131 is emplaced in the borehole, at 3 or 4 points in the water column, by a simple injection device whereby the isotope ampoule is shattered by a messenger sent along the wire holding the tracer ampoule. Either compressed air or the drill bailer is used to mix the tracer uniformly throughout the water column. Subsequent monitoring with a nuclear detector at time intervals reveals the zones of flow. We have used both the pulse/velocity method and the Total Count Technique, (which is uniquely applicable to radio tracers) to quantify the flow into or out of the borehole at the particular zone. Further, a quantitative measure of through-flow in the borehole as an entity can be obtained.

The direction of flow can also be determined by use of a collimated detector which is rotated through 360° at the required horizon. The position
Engineering geology of the Gordon Dam, South West Tasmania
Authors: Andric M. , Roberts G. T. , Tarvydas R. K.
Published: November 2007

The Gordon Dam is a double curvature concrete arch structure 140 m high, forming part of a hydro-electric scheme. The dam is sited on folded and faulted Precambrian quartzite. Driving adits was favoured over diamond drilling in siting the dam and for detailed investigations to prove the stability of the foundations.

Considerable excavation on the left abutment was necessary to remove unfavourable rock and a continuous pre-split face of 122 m was produced.

The geological conditions found during excavation were better than anticipated thus raising the computed factor of safety.
Mudrocks of the Devonian
Authors: House M. R.
Published: November 2007

Introduction

Around the close of the Silurian, but with associated igneous and volcanic events lasting well into the Devonian, occurred the major phase of the Caledonian Orogeny. The main mountain belt resulting from this, stretched from the joined area of Spitsbergen, E Greenland and Norway SE for some 4000 km, the belt being up to 600 km in width. Detritus from the erosion of this belt produced the Old Red Sandstone deposits of Ireland, Wales and Scotland with extensions in the early Devonian into southern England. Later, south of the Bristol Channel to Thames Estuary line, elastics were laid down mostly under marine conditions with a transitional zone in N Devon.

Mudrocks in the Devonian thus occur in several distinct sedimentary regimes: in the north, terrestrial facies (Old Red Sandstone) formed as intermontaine basins and lacustrine areas in Scotland, and as alluvial and pedogenie facies of extensive coastal plains in southern Wales and, whilst usually thought to consist of coarse and red arenites, do, in fact, include in aggregate significant proportions of usually poorly-sorted, fine-grained rocks. The near-shore marine deposits (Rhenish facies) include mixed arenite/pelite/carbonate sequences in which the pelites may be thick. But it is in the offshore and basinal areas (Hercynian facies) that mud-grade sediments reach their finest development, seen especially in Cornwall, where successions of little else total several thousand metres. These are now in the form of indurated and cleaved argillites forming most of the ‘killas’ of southern Devon and Cornwall.

The areas of outcrop of
Laboratory investigation of mudrocks
Authors: Taylor R. K. , Spears D. A.
Published: November 2007

The problems associated with mudrocks are largely controlled by their lithology and degree of compaction, their susceptibility to water (volume change), the high frequency of discontinuities and their anisotropic character. It is in ground engineering where difficulties are most frequently encountered and for this reason the laboratory investigation is directed towards these issues. Mudrocks are distinguished for these purposes as argillaceous sediments containing more than 500y weight of clastic grains of less than 60 ώm in size. They can range from
very strong
indurated Palaeozoic mudstones to
stiff
over-consolidated clays of the Jurassic, Cretaceous and Eocene sequences.

Because the spectrum of types is so wide, the laboratory investigation is considered as a testing programme which is itself determined by known mudrock behaviour. In this way the rationale behind the test modules is developed under the following sectional titles: I. index tests and classification; II. bearing capacity and settlement; II. physical effects of water; IV. mineral changes and porewater chemistry; V. stability of slopes; VI. mine and tunnel considerations.

Attention is drawn to specific references (and standards) in which details of advocated laboratory tests and methods may be found.
C. D. W
arren
writes
Authors: Warren C. D.
Published: November 2007

The author is to be congratulated on a most interesting paper, but with regard to the use of the computerized data bank of borehole records for the Jubilee Line investigation it should be emphasized that the data bank was not programmed to include such detail as the presence of hard limestone bands, flint beds and minor lithological variations along the route. This detail was added from existing borehole information.

Furthermore, since the computer was not programmed to include a break and known throw across faulted areas, faults were represented by steep monoclinal gradients between definitive boreholes. For example, Fig. 1, which is based on approximately 2500 boreholes covering the London area, shows the Raynes Park and Greenwich faults south of the Thames river as monoclinal flexures superimposed on the general geology.

Some of the differences between the real and predicted geologies for the Jubilee Line can be explained by lack of previous borehole data along certain sections of the route and this was taken into account in the siting of the investigation boreholes.
On the engineering properties of salina soil
Authors: Stipho A. S.
Published: November 2007

Subsoil in desert regions is a product of temperature changes, wind and rainfall. Soil in a subtropical climate, such as that of Saudi Arabia, would be the best representative example for the study of soil condition in arid and extremely arid regions. A high temperature climate increases evaporation and reduces moisture in the soil, resulting in development of salt-bearing soil. Depending upon some geological, climatic considerations salt content in Saudi Arabia soil is invariably high. Understanding and anticipating the nature of changes in such considerations and the associated geotechnical problems in these regions is very important for practising engineers in the area. This is particularly important during the design and construction stage, in order to evaluate and solve unforeseen problems. The foundation problems which arise due to various concentrations of sodium or calcium chlorides in desert soils are pinpointed and discussed. The influence of the salt on the laboratory-observed properties of desert soil is investigated.
Field techniques using borehole packers in hydrogeological investigations
Authors: Brassington F. C. , Walthall S.
Published: November 2007

As part of a hydrogeological investigation in a Permo-Triassic Sandstone aquifer in northwest England, various methods of field permeability testing have been developed and evaluated. These techniques involve the use of borehole packers to isolate specific test sections and permeability measurements made by either injection or pumping tests. Field results have been compared with both laboratory permeability measurements and conventional pumping tests. The test procedures were found to have a significant effect on the results obtained. Packers have also been employed to examine the vertical distribution of piezometric heads within an aquifer, both in pumping and non-pumping conditions, and to obtain groundwater samples from selected horizons. Some of the test results are presented to illustrate the value of packer techniques in hydrogeological investigations.
Discussion on ‘The stabilization of some arid zone soils with cement and lime’ by G. Akpokodje
Authors: Clarke J. D. , McMahon P. H.
Published: November 2007

Whilst investigating the use of cement stabilized minestone (discard from coal mining operations) as a structural element in a highway pavement, a number of soaking tests were conducted using a similar procedure to that described by the author. The results were broadly similar to those shown in his table 4 with soaked strengths (calculated as percentages of normally cured strengths), shown below in Table 1.

Observations made during these tests have provided an opportunity to re-appraise the philosophy of the experimental procedure.

The mechanism for strength changes described by the author is widely accepted and the comments relating to salt content are particularly useful, but the test procedure is not sufficiently investigative and merely reflects conventional wisdom with respect to water adsorption by clay soils and volume changes imposed by sulphate-cement reactions.

Water absorption by clay minerals is a function of mineral type and of previous stress history. Those clays which have been subject to diagenetic changes imposed by high overburden pressures react quite differently from geologically ‘young’ clays with respect to swelling characteristics as an inspection of e-σ′ curves will show. The strength reduction mechanism for soaked specimens of cement stabilized materials containing clay shale is probably related to the generation of excess pore water pressures caused by a combination of the applied load and the free water held in the voids of the material. Measurements of mass increase after 7 days soaking confirm water uptake but these are not balanced by contributory volume changes.

For the mixing moisture
Clay minerals in engineering geology
Authors: Privett K. D.
Published: November 2007

Mr D. N. Holt, Chairman of the Engineering Group, welcomed the large audience to the Meeting, designed to promote the interchange of ideas between Clay Mineralogists, Engineering Geologists and Geotechnical Engineers. Nine papers were presented and discussed:

Engineering geology of clay minerals: swelling, shrinking and mudrock breakdown
by Dr R. K. Taylor of University of Durham who introduced the theme of the Meeting.

Argillaceous sediments make up about 60% of the geological column, clay minerals accounting for about two-thirds of the constituents of over-consolidated clays and mudrocks. In North America, expansive clays are regarded as the principal hazard, whilst in southeast England shrinkage of heavy clays is the main geotechnical problem. Expansive clays are rarer in the older rocks, and in the UK there are virtually none below the Silurian. After summarizing the structure of clay minerals Dr Taylor discussed problems caused by expanding seat earths and roof seams in coal mines. Formation waters are generally saline, creating Na-montmorillonite which is more expansive than the Ca variety, exacerbating the problems. Swelling is divided into mechanical or physicochemical in origin; a mechanical origin is more common in soil mechanics problems, clay minerals may not be involved. Samples recovered from depth with high K
Q
values may swell in a total stress oedometer because of high suctions generated by stress release on sampling. In long-term excavations mechanical and physicochemical swelling can take place. The swelling process of clays is a function of absorbed water; there is strongly bonded water near the surface of
The cliff face under the Clifton suspension bridge, Avon Gorge, Bristol
Authors: Hawkins A. B.
Published: November 2007

For many years, blocks of rock have occasionally fallen from the slope of the Avon Gorge on to the A4 road (the Portway), which runs along the eastern side of the Gorge. Indeed, there is no reason to believe this was not a hazard long before Brunei designed the impressive suspension bridge over the river.

The photograph opposite shows the general area at the eastern side of the Gorge the bridge tower being almost directly at the top of a sub-vertical rock cliff face, about 75 m high. The photograph also shows a number of fractures, aligned almost parallel to the rock face. It does not show the partially dissolved fracture, about 300 mm wide, which can be seen from the Portway in the cliff immediately behind the eastern tower.

In the late 1970s, the owners of the cliff face and the highway authority both became increasingly conscious of the danger of falling blocks and instigated a study to determine most effective and economically viable course of action. Although it was considered that bolting and meshing could provide a solution, it was felt that long-term security and environmental requirements would best be served by the construction of a canopy.

Figure 1
shows the fractured nature of the rock when it was inspected after the face had been cleaned of all vegetation. The sub-parallel tectonic-stress induced fractures are clear, as is the broken state of the limestone beds.

Figures 2
and
3
show the detailed state of the rock when inspected.
Laboratory measurement of the thermo-hydro-mechanical properties of rock
Authors: Elliott G. M. , Brown E. T.
Published: November 2007

The need to exploit further a number of potentially important energy resources has necessitated a better understanding of the behaviour of rock at elevated temperatures. This paper describes a testing facility capable of testing medium sized cylindrical rock specimens under confining pressures to 140 MPa, pore pressures to 105 MPa, axial loads to 2.67 MN and sample temperatures to 400°C. Descriptions are given of the procedures and techniques used in the test facility to carry out triaxial compression tests, permeability and thermal conductivity tests, and measurements of the coefficient of linear thermal expansion. Data for a granite and a sandstone are given and discussed briefly in order to illustrate the wide-ranging capability of the test facility to meet many of the perceived needs for research into the thermo-hydro-mechanical behaviour of rock.

In addition to these basic types of test, an example is given of the use of the test facility to simulate in situ conditions in order to observe the response of the rock to engineering procedures.
Analytical photogrammetry: a method for monitoring slope instability
Authors: Chandler J. H. , Moore R.
Published: November 2007

Developments in analytical photogrammetry provide the engineering geologist and geomorphologist with a quantitative technique capable of monitoring slope instability from ground or oblique aerial photographs. This paper outlines ‘analytical’ photogrammetry and its applications to the study of slope instability. Procedures and developments in data processing are described that enable both a morphogenetic analysis of slope form and the derivation of displacement vectors for monitoring unstable slopes. The methods are illustrated by research work carried out by the authors in Nepal and southern England.
The influence of macropores on debris flow initiation
Authors: McDonnell J. J.
Published: November 2007

Soil structure affects the movement of water in hillslope soils and therefore exerts a strong influence on slope stability. A debris flow is analysed within the confines of an instrumented catchment on the South Island, New Zealand, in order to examine the influence of soil macropores on slope stability. Tensiometric and slope throughflow data for nearby slope areas show that vertical cracks conduct rainfall at rates well in excess of the mineral soil matrix conductivity. The presence of a well connected pipe system at the soil-bedrock interface distributes this water quickly downslope. Under exceptionally high rainfall intensities, however, this crack-pipe system may induce slope instability by increasing the rate of infiltration over lateral pipeflow rates. This results in a build-up of pore pressure at the soilI–rock interface and subsequent slope failure.
Extent of permafrost in southern Britain in relation to geothermal flux
Authors: Hutchinson J. N. , Thomas-Betts A.
Published: November 2007

Introduction

The scarcity of relic permafrost features in southwest England, except on the high ground of Dartmoor, was noted by Williams (1965, 1969). Following
Manley (1951, 1953)

he concluded that this was due primarily to a moderation of the Pleistocene climate by invasions of milder Atlantic air. Subsequent work through the CLIMAP project (
McIntyre et al 1976
), however, suggests that at 18000 years BP, the North Atlantic polar front was at about the latitude of Portugal. Comparison of Williams' map of the areal extent of permafrost in southern Britain with the detailed heat flow map of the UK (
Wheildon & Rollin 1986
) indicates that regions where evidence of former permafrost is largely absent tend to coincide with areas of high heat flow.
The technical note discusses possible relationships between heat flow and permafrost phenomena in southern England as it is clearly important that engineers making site assessments are aware of the likely causes and extent of the disturbance associated with former frozen ground.

Extent and depth of former permafrost in southern Britain Figure la is a reproduction of
Williams' (1969)
map which was based on the deeper periglacial features, particularly ice-wedge casts. It shows that there are far fewer permafrost features in the southwest than in most of Britain. Since then more ice-wedge casts have been found in southwest England, but it is nevertheless generally accepted that in this area the frequency and depth of these is significantly less than
Gas migration studies at a disused mine to detect possible rock fracture patterns and the extent of underground workings
Authors: Sibley R. D.
Published: November 2007

Bushdown Mine in southwest England was operational in the late 18th to early 19th Centuries for the extraction of tin. Natural concentrations of five soil gas components were investigated across the probable position of an adit. The gas variations detected are attributed to the presence of the adit and the near-surface enhanced fracturing thought to be associated with it. A tracer gas was released underground near the collapsed end of another adit at shallow depth. A programme of monitoring at a series of locations on the surface indicated the emergence of the gas a few hours after its release. The increase of tracer gas at the surface and the time lapse between gas release and measurement of the maximum increase is attributed to increased permeabilities along preferential gas migration pathways leading from the adit.
Comparison of interpretations of a major landslide at an earthfill dam site in Papua New Guinea
Authors: Fookes P. G. , Dale S. G.
Published: November 2007

An earthfill tailings retention embankment across the Ok Ma valley in a remote tropical rainforest area of western Papua New Guinea was abandoned during construction in early 1984 because of a very large landslide that occurred in the eastern abutment of the dam. Ensuing litigation between the mine owners and their insurers brought together highly qualified and experienced geotechnical experts. The experts developed their own views on the form, nature and mechanism of the landslide which occurred in limestone colluvium and Miocene mudstone bedrock.

After preliminary studies and site investigations, work for the mining company on the tailings dam was carried out as a design-and-construct package by a major consortium. Sub-sequent design investigations used most of the available techniques, including aerial photograph interpretation, seismic traverses, pitting, drilling and in situ and laboratory testing, all carried out by experienced specialist companies. Although concern was expressed on various aspects of temporary and permanent slope stability, the large size of the landslide came as an unforeseen event.

This paper presents the authors' interpretation of six different models proposed for the landslide by various authorities who worked on the case. This has been done to illustrate the difficulties in attempting a precise interpretation of a large landslide and as a commentary on the state of the art on the subject.
Clay linings to landfill sites
Authors: Murray E. J. , Rix D. W. , Humphrey R. D.
Published: November 2007

Seepage of leachate or the migration of noxious gases from landfill sites can pollute the ground and groundwater to a considerable distance from the source of the problem. Current trends and legislation dictate that future practice at waste disposal sites will be to provide a lining capable of eliminating or minimizing the migration of contaminants. Geotechnical considerations in the design and construction of low-permeability clay linings are addressed and laboratory test results for a range of clay types are presented in support of the arguments. The use of the moisture condition value (MCV) test in the selection of acceptable materials and the control of earthworks operations is discussed. A permeability requirement of no greater than 10-9 m/s for the clay lining dictates the upper limit to the acceptable MCV range while the shear strength dictates the lower limit.
Bedding karst and multilayered groundwater flows in karstic block mountains in the northeast of Mount Xishan, Taiyuan, China
Authors: Zhang Dachang
Published: November 2007

The hydrogeology of the northeastern part of Mt Xishan has historically been interpreted in terms of a simple unconfined aquifer model. The groundwater required is characterized by (1) karst terrain, (2) multilayered unconfined groundwater flow developed in block mountains involving rapid hanging discharges and (3) deep confined groundwater with a carbon 14 age of 1000–2800 years and low tritium content. The flows are partly towards the southern part of Mt Xishan, partly east towards the porous aquifers of the Nitun Basin and partly discharging through the Lancun Spring system.

The spatial structure of karst aquifers in block mountains is elucidated by an understanding of stratigraphic, structural, lithological, climatic and karst geomorphological evolution. The actual complex hydrogeological conditions in the Mt Xishan area considered are demonstrated by a comprehensive model proposed by the author. Such a model may also be applied in other karstic block mountains.
Recharge of the Lower Greensand aquifer at Slough, England
Authors: Egerton R. H. L.
Published: November 2007

The Lower Greensand beneath Slough has provided a constant and reliable supply of high quality water to local industry since 1909. The source of this water has always been uncertain and it is thought that it is either derived from storage or recharged from the outcrops. An alternative explanation is presented that assumes downward leakage from the Chalk through the Upper Greensand and Gault, together with recharge occurring under the Chilterns to the north of Slough. The clay minerals in the Gault have removed the calcium ions, thus softening the water. The mineral glauconite in the Lower Greensand and other factors may also affect the hydrochemistry. The structure of the strata beneath Slough is such that there is a corridor of more transmissive Lower Greensand abutting the London Platform. This has enabled flow to occur from north to south since the Pleistocene so that the saline connate groundwater has been largely flushed out and replaced by water of high quality.
Aggregate properties and resources of granitic rocks for use in concrete in Hong Kong
Authors: Irfan T. Y.
Published: November 2007

Granitic rocks are the major source of crushed fine and coarse aggregates for use in concrete in Hang Kong. The existing quarries are situated in a variety of granite types. Although some quarries produce coarse aggregates with better properties, most are considered unsuitable for special purposes.

Laboratory testing of the various granite types present in the Territory indicates that fine-grained granites have superior mechanical and physical properties in comparison with other granite types and hence are potentially suitable for many special concrete purposes.
A revision of the graphical method for assessing the excavatability of rock
Authors: Pettifer G. S. , Fookes P. G.
Published: November 2007

A ‘size-strength’ graph, subdivided for various methods of excavation, was published by Franklin, Broch & Walton in 1971. Although this graph allows excavatability to be assessed rapidly, the subdivisions have become outdated as more powerful, more efficient equipment has become available. A complete revision of the graphical method, based on more than 100 case studies, is proposed. Particular emphasis is placed on rock masses which can be broken up solely by mechanical means such as ripping. Procedures are recommended for obtaining geotechnical data, and the importance of interpreting field observations in their geomorphological context is discussed. Consideration is also given to the effects of block shape and orientation on ripper performance, and adjustments to the input data are suggested. The revised graph is intended for all types of project but especially for road construction, where plant mobility and flexibility are important.
A technique for defining non-linear shear strength envelopes, and their incorporation in a slope stability method of analysis
Authors: Perry J.
Published: November 2007

The peak shear strength envelope of soils, rock fills, highly weathered rock and jointed rock can exhibit significant curvature over a range of stresses. In the past a power curve relation has been used to represent this non-linear envelope. An accurate and rigorous method is given which calculates the ‘best fit’ power curve relation to test data in the form of Mohr circles. The mathematical function for the power curve then represents the shear strength equation. In order to test and study the method, it is applied to shear strength results, from tests on six overconsolidated clays. The failure envelopes for the clays are significantly curved and a power curve relation provides a good estimate of the failure envelopes. Comparisons with linear failure envelopes clearly show that, over the same stress range, the power curve relation is the more realistic approximation of shear strength.

A slope stability method of analysis is given which uses the power curve relation for the shear strength of materials. It can be used for slopes in, or constructed of, soils, rock fills or highly weathered rock where a non-linear failure envelope is representative of shear strength. The method is based on Janbu's Rigorous Method of Slices and is for use in analysing failures with a failure surface of arbitrary shape.
Geotechnical background to problems of conservation of the medieval centre of Tricarico, southern Italy
Authors: Bromhead E. N. , Coppola L. , Rendell H. M.
Published: November 2007

In common with many other hilltop settlements throughout central and southern Italy, Tricarico is subject to a range of geotechnical and geological hazards which arise largely from the tectonic setting of the area in which it is situated. Hazards include both earthquakes and landslides. The former are experienced throughout the town, but the latter are a problem mainly in locations along the edges of the calcarenite ridge on which the town is built, where the calcarenite and the underlying overconsolidated Pliocene clays are involved. The town possesses an almost perfectly preserved medieval centre, dating from the 10th century. Conservation of this architectural heritage poses a series of problems arising from economic and political pressures, as well as from population changes in this part of Italy, and conservation issues arising out of damage experienced in the November 1980 earthquake are still unresolved, not least because of uncertainty about geological conditions in the worst affected areas of the town. Conservation measures also need to take into account the current instability experienced in the peripheral areas of the historic centre, and the probable future development of these areas. The paper describes a series of investigations into the geotechnical hazards which threaten the town, and which have a bearing on the deliberations of the community in seeking a proper response to the challenges of conservation in such an active area. Among these investigations are surface surveys, and subsurface investigations into the geological structure of the town. From the data it has been possible to draw inferences as to the measures necessary to control slope movements in the worst affected areas. In addition, the effect of the geological structure on the physical response of the town to recent and past seismic events is considered. Proposals for remedial measures to improve slope stability, and strategies to improve the general resistance of the town to seismic damage, are reviewed.