bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical Surface Shear Rate Evaluation in Models of the Renal Artery
Authors: El Masry O. A. , Feuerstein I. A.
Published: June 2009

Electrochemical measurements of surface shear rate were done in two renal artery models with 45 and 90-deg take-off angles to determine the extent to which the parent tube flow rate, flow division and branch shape influence flow at sites for atherogenesis. The dependence of surface shear rate on each of these independent variables was nonlinear; mathematical relationships which could predict surface shear rate at other flow rates, flow divison ratios or vessel shapes did not emerge. The results of this work along with reports of others, which demonstrate great variability in location and extent of atherosclerotic lesions, support the conclusion that pathological studies and flow studies should be done simultaneously if the role of flow in atherogenesis is to be elucidated.
An Analytical Technique for Modeling Knee Joint Stiffness—Part I: Ligamentous Forces
Authors: Grood E. S. , Hefzy M. S.
Published: June 2009

The purpose of this study is to present an analytical technique to evaluate the nonlinear, coupled stiffness characteristics of the human knee joint. In the present work, a model of the knee is developed which permits the contribution of the ligaments to the nonlinear, coupled stiffness characteristics of the knee to be determined from their nonlinear load-elongation properties, the geometric location of their insertion sites, and the relative position of the femur with respect to the tibia. Calculations with the model are compared to those obtained using Crowninshield, et al. [1] model and experimental data.
In-Vitro of Measurement of Static Pressure Distribution in Synovial Joints—Part I: Tibial Surface of the Knee
Authors: Ahmed A. M. , Burke D. L.
Published: June 2009

In this first part of a two-part paper, the results of measurement of static pressure distribution on the tibial surface of the knee are presented. Results with intact menisci have been obtained from 18 specimens. Eight of these specimens were the subject of further measurements following medial meniscectomy. The study has been carried out at various flexion angles of the knee with the joint subjected to a compressive force, with or without an initial passive relative displacement between the joint members. The results indicate that a significant fraction of the joint compressive load is transmitted through the menisci and that total meniscectomy causes a drastic alteration in the pressure distribution on the tibial surface. Clinical implications of these results, in terms of post-meniscectomy degenerative changes and mechanism of meniscal lesions, have been discussed.
Predictions of the Existence, Frequency, and Amplitude of Physiological Tremor in Normal Man Based on Measured Frequency-Response Characteristics
Authors: Zahalak G. I. , Cannon S. C.
Published: June 2009

Mathematical models for 1) musculoskeletal dynamics, and 2) reflex feedback, based on the results of the authors’ frequeny-response measurements on normal adult male human subjects, are combined to produce a model for physiological tremor in such subjects. An analysis of this model shows that the system will be unstable to small disturbances (that is, tremor will occur) under certain conditions of external loading. Further, when the system is unstable, nonlinearities in the model produce responses in the form of limit cycles, and both the frequency and amplitude of the resulting tremor can be calculated. For constant loads applied through a constant compliance, the model predicts the onset of tremor at low loads, a maximum intensity of tremor at loads corresponding to 30–50 percent of maximum voluntary effort, and a decrease in the tremor amplitude at still higher loads.
The Impedance of Curved Artery Models
Authors: Kang S. G. , Tarbell J. M.
Published: June 2009

The impedance (pressure drop/flow rate) of four curved artery models has been determined experimentally for steady and periodic flows simulating conditions in the aortic arch. Steady flow results indicate that very short entry lengths are required for flow development in curved artery models, and impedance is elevated above straight tube values by a factor of 3–4 for mean flow conditions in the aortic arch. Results for periodic flow with a nonzero mean show a significant elevation of mean flow impedance relative to values for steady flow at the mean flow rate—a factor of 2–3 for aortic arch flow conditions. The impedance of the first harmonic of periodic flows follows straight tube theory at high values of the unsteadiness parameter in agreement with available theory for curved tubes. The implications of the impedance measurements for wall shear stress in the aortic arch are discussed.
A Three-Dimensional Model of the Human Cervical Spine for Impact Simulation
Authors: Williams J. L. , Belytschko T. B.
Published: June 2009

A three-dimensional analytical model of the cervical spine is described. The cervical vertebrae and the head are modeled as rigid bodies which are interconnected by deformable elements representing the intervertebral disks, facet joints, ligaments and muscles. A special pentahedral continuum element for representing the articular facets is described which effectively maintains stability of the cervical spine in both lateral and frontal plane accelerations, which is very difficult with multispring models of the facets. A simplified representation is used for the spine and body below the level of T1. The neck musculature is modeled by over 100 muscle elements representing 22 major muscle groups in the neck. The model has been validated for frontal and sideways impact accelerations by simulating published experimental data. Results are also presented to show the effects of the stretch reflex response on the dynamics of the head and neck under moderate acceleration.
Oxygen Diffusion in Blood: A Translational Model of Shear-Induced Augmentation
Authors: Diller T. E. , Mikic B. B.
Published: June 2009

Possible models of shear-induced augmentation of oxygen transfer in laminar blood flow are discussed and evaluated in the light of recently published experimental results [1]. A new transfer augmentation model is presented which evaluates the effect of microscopic translational motions of the red blood cells back and forth across the flow streamlines. The results of this model appear to be consistent with the experimentally measured diffusion augmentation.
Analysis of the Water Permeability of Human Granulocytes at Subzero Temperatures in the Presence of Extracellular Ice
Authors: Schwartz G. J. , Diller K. R.
Published: June 2009

The plasma membrane water permeability of human granulocytes in the presence of extracellular ice was determined experimentally on a cryomicroscope. Transient volumes of individual cells were measured at constant subzero temperatures subsequent to ice nucleation. Permeability values were deduced by adjustment of multiple parameters in a model to obtain an optimal fit to the data. The permeability was determined to be a function of both temperature and intracellular solute osmolality, with a reference value at 0°C of 0.407 μm/atm·min and temperature and solute coefficients of 218kJ/mol and 1.09 Osm/kg.
Abnormalities in the Membrane Material Properties of Hereditary Spherocytes
Authors: Waugh R. E. , La Celle P. L.
Published: June 2009

Mechanical measurements of intrinsic membrane material properties are used to characterize the defect in hereditary spherocyte membrane at a continuum level. The value of the surface elastic shear modulus is two-thirds as large as normal values, and the value of the yield shear resultant is one-third as large as normal values. The viscosity of the surface above the elastic-plastic transition appears normal. Under similar geometric conditions, the force required to fragment a hereditary spherocyte is about one-third as large as the force required to fragment a normal cell.
Estimation of Tissue Blood Perfusion Rate from Diffusible Indicator Measurements: A Sensitivity Analysis
Authors: Shitzer A. , Eberhart R. C. , Eisenfeld J.
Published: June 2009

Recording the washout of indicator (for example, heat, radio-labeled dissolved gas, etc.) transiently introduced into tissue allows the estimation of tissue blood perfusion rate. Analysis of the washout data requires a material balance which appropriately accounts for all transport mechanisms and sources and sinks of the given indicator. From that balance one may perform a sensitivity analysis which specifies the susceptibility of the perfusion estimate to experimental errors in any of the pertinent parameters and variables. The sensitivity analysis is based on the normalized partial derivatives of tissue indicator concentration with respect to the experimental variables. The results indicate that the estimation of the tissue blood perfusion rate is highly sensitive to errors in the concentration of the diffusible indicator which dominate, by two orders of magnitude or more, the errors attributed to other parameters. For typical experimental conditions, the errors in the perfusion estimate due to the various parameters are shown to vary considerably, according to the sensor position and time of measurement. Based on this type of analysis, one may specify optimal temporal and spatial domains for the parameter estimation in order to minimize error propagation. The optimal time domains are shown to differ from those used in typical indicator washout analyses for estimating tissue perfusion rate.
The slipping slipper sign: a marker of severe peripheral diabetic neuropathy and foot sepsis
Authors: Teelucksingh S , Ramdass M J , Charran A , Mungalsingh C , Seemungal T , Naraynsingh V
Published: June 2009

Background

Peripheral neuropathy is a major contributor to diabetic foot complications including ulceration, sepsis and limb loss. The aim of this study was to document the frequency of this previously undocumented clinical marker of peripheral neuropathy, the “slipping slipper sign” (SSS), characterised by unrecognised loss of slippers from one’s feet while walking, and to compare it with traditional clinical tests for peripheral neuropathy.

Objective

To evaluate the relationship between a positive SSS and diabetic peripheral neuropathy.

Subjects and methods

The study included 105 diabetic outpatients without active foot problems, 40 diabetic inpatients with active foot sepsis, and 69 other patients with neither diabetes nor active foot sepsis as negative controls. Demographic data, clinical neuropathy scores and the presence or absence of the SSS were obtained.

Results

No control subjects had a positive SSS. In contrast, 64 of 145 diabetic patients had severe neuropathy of whom 53 had a positive SSS (83% sensitivity) and 74 of 81 without severe neuropathy had a negative SSS (91% specificity). Diabetic patients with concurrent foot sepsis had a higher frequency of severe neuropathy (70%) and positive SSS (65%) compared with those without (36% and 35%, respectively, p<0.001). Multivariate analysis showed that a positive SSS was strongly related to severity of neuropathy independent of duration of diabetes.

Conclusion

The SSS reflects severe peripheral neuropathy and is particularly prevalent among those with active foot disease. Patients who have experienced the SSS should be encouraged to seek attention and preventive action taken.
THE HYBRID FUNCTION PROJECTIVE SYNCHRONIZATION OF CHAOTIC SYSTEMS
Authors: YU YONG-GUANG , LI HAN-XIONG , YU JUN-ZHI
Published: June 2009

This paper mainly investigated a hybrid function projective synchronization of two different chaotic systems. Based on the Lyapunov stability theory, an adaptive controller for the synchronization of two different chaotic systems is designed. This technique is applied to achieve the synchronization between Lorenz and Rössler chaotic systems, and the synchronization of hyperchaotic Rössler and Chen systems. The numerical simulation results illustrate the effectiveness and feasibility of the proposed scheme.
ENTANGLEMENT AND INFORMATION TRANSFER PROTOCOL BETWEEN TWO QUBITS
Authors: METWALLY NASSER
Published: June 2009

Based on the general unitary operations of two-qubit system, we investigate the dynamics of information swapping between two qubits. We briefly describe the general behavior of entanglement entropy and the purity taking into account two classes of initially states, either product state or entangled state. Using the phenomenon of information swapping, we suggest a theoretical protocol to transform the coded information from sender to the receiver.
TIME-RELAXED 1-FAULT TOLERANT BROADCAST NETWORKS
Authors: RIEKSTS BRIAN Q. , VENTURA JOSE A.
Published: June 2009

In a 1-fault tolerant minimal broadcast network, a node of a network, called the originator, has a message which is to be transmitted to all other nodes of the network in minimum time regardless of the failure of a single communication line. In some instances, it is advantageous to use time-relaxed broadcast networks that require slightly more than the minimum transmission time, but have sparser edge sets. This paper presents a general compounding algorithm to construct sparse, time-relaxed, 1-fault tolerant broadcast networks. In the algorithm, copies of a broadcast network without faults are interconnected with additional edges according to the structure of a 1-fault tolerant broadcast network with two special properties. Both the 1-fault tolerant broadcast network and the broadcast network without faults may be time-relaxed. Computational results show that the algorithm yields sparser networks by allowing additional time units.
COHERENT STATE OF THE EFFECTIVE MASS HARMONIC OSCILLATOR
Authors: BISWAS ATREYEE , ROY BARNANA
Published: June 2009

We construct coherent state of the effective mass harmonic oscillator and examine some of its properties. In particular closed form expressions of coherent states for different choices of the mass function are obtained and it is shown that such states are not in general x - p uncertainty states. We also compute the associated Wigner functions.
RF RAT-RACE COUPLERS WITH U-TYPE DGS MICROSTRIP ELECTROMAGNETIC BAND GAP ELEMENT
Authors: ZHANG FEI
Published: June 2009

In this letter, an investigation of a novel compact rat-race hybrid coupler incorporating a U-type defected ground structure (UDGS) is presented. Served by this microstrip electromagnetic band gap element (MEBE) technology, the size of the coupler is reduced due to its slow-wave effect and its band-stop effect enables strong high-order harmonics rejection. In the meantime, the measured performance of the proposed coupler is comparable to that of a conventional microstrip hybrid coupler. This miniaturization and harmonic suppression technology has great potential application in MICs and MMICs to reduce circuit size, lower material cost and improve the overall performance of wireless communication systems.
THE MAXIMUM ENTROPY PRINCIPLE: A GENERALIZED CONSTRAINT-BASED ENTROPY
Authors: CHAKRABARTI C. G. , CHAKRABARTY I. , GHOSH KOYEL
Published: June 2009

We have derived a new generalized constraint-based entropy on the basis of the maximum entropy principle. The new entropy which is very similar to, but different from Havrda and Charvat entropy and Tsallis entropy, reduces to the form of Shannon entropy in a limiting case. The characteristics properties of this new entropy have been pointed out.
K-MEANS CLUSTERING FOR PROBLEMS WITH PERIODIC ATTRIBUTES
Authors: VEJMELKA M. , MUSILEK P. , PALUŠ M. , PELIKÁN E.
Published: June 2009

The K-means algorithm is very popular in the machine learning community due to its inherent simplicity. However, in its basic form, it is not suitable for use in problems which contain periodic attributes, such as oscillator phase, hour of day or directional heading. A commonly used technique of trigonometrically encoding periodic input attributes to artificially generate the required topology introduces a systematic error. In this paper, a metric which induces a conceptually correct topology for periodic attributes is embedded into the K-means algorithm. This requires solving a non-convex minimization problem in the maximization step. Results of numerical experiments comparing the proposed algorithm to K-means with trigonometric encoding on synthetically generated data are reported. The advantage of using the proposed K-means algorithm is also shown on a real example using gas load data to build simple predictive models.
FINITISTIC DIMENSIONS OF TRIVIALLY TWISTED EXTENSIONS OF MONOMIAL ALGEBRAS
Authors: SHI HONGBO
Published: June 2009

We use the algorithms Bottomup and Topdown to study the finitistic dimensions of a class of extension algebras: the trivially twisted extensions of monomial algebras. A hybrid algorithm for determination of the finitistic dimension of the aforementioned extension is presented, and in particular, conditions for construction of such extensions that have relatively larger finitistic dimension are investigated.
MODIFIED BRANEWORLD COSMOLOGIES IN THE PRESENCE OF STRINGY CORRECTIONS COUPLED TO A CANONICAL SCALAR FIELD
Authors: EL-NABULSI R. A.
Published: June 2009

The purpose of this paper is to study braneworld cosmologies in the presence of stringy corrections coupled to a canonical scalar field. Two independent models are explored which in their own right provide cosmologies exhibiting the present cosmic acceleration of the universe. The evolution of the cosmological scale factor is studied in four and ten-dimensional space–times. The four-dimensional model is preformed in the context of the nonminimal Maxwell–Gauss–Bonnet gravity while the ten-dimensional model is constructed from the implications of Kaluza–Klein cosmology together with the Gauss–Bonnet Lagrangian in the action with matter fields nonminimally coupled to gravity. Both the low energy and high energy limits are discussed for the two models and many interesting features are described in some detail.
INDEPENDENT ANALYSIS OF THE ORBITS OF PIONEER 10 AND 11
Authors: TOTH VIKTOR T.
Published: June 2009

Independently developed orbit determination software is employed to analyze the orbits of Pioneer 10 and 11 using Doppler data. The analysis takes into account the gravitational fields of the Sun and planets using the latest JPL ephemerides, accurate station locations, signal propagation delays (e.g. the Shapiro delay, atmospheric effects), the spacecraft's spin, and maneuvers. New to this analysis is the ability to utilize telemetry data for spin, maneuvers, and other on-board systematic effects. Using data that were analyzed in prior JPL studies,1,2 the anomalous acceleration of the two spacecraft is confirmed. We are also able to put limits on any secondary acceleration (i.e. jerk) terms. The tools that were developed will be used in the upcoming analysis of recently recovered Pioneer 10 and 11 Doppler data files.
SCENARIOS OF COSMIC STRING WITH A VARIABLE COSMOLOGICAL CONSTANT
Authors: RAY SAIBAL , RAHAMAN FAROOK , MUKHOPADHYAY UTPAL
Published: June 2009

Exact solutions to the Einstein field equations with cosmic string and a space-varying cosmological constant, viz. Λ = Λ(r), in the energy–momentum tensors are presented. Three cases have been studied: the variable cosmological constant (1) has power law dependence, (2) is proportional to the string fluid density, and (3) is purely a constant. Some cases of interesting physical consequences have been found where (i) the variable cosmological constant can be represented by a power law of the type Λ = 3r-2, (ii) the variable cosmological constant and the cosmic string density are interdependent according to the relation Λ = -8πρs, and (iii) the cosmic string density can be scaled by a power law of the type ρs= r-2. It is also shown that several known solutions can be recovered from the general form of the solutions obtained here.
QUADRATIC FORMULAS FOR GENERALIZED QUATERNIONS
Authors: ABRATE MARCO
Published: June 2009

In this paper we derive explicit formulas for computing the roots of a quadratic polynomial with coefficients in a generalized quaternion algebra over any field 𝔽 with characteristic not 2. We also give some example of applications for the derived formulas, solving equations in the algebra of Hamilton's quaternions ℍ, in the ring M2(ℝ) of 2 × 2 square matrices over ℝ and in quaternion algebras over finite fields.
CONFIGURATION OF NILPOTENT GROUPS AND ISOMORPHISM
Authors: ABDOLLAHI A. , REJALI A. , YOUSOFZADEH A.
Published: June 2009

The concept of configuration was first introduced by Rosenblatt and Willis to give a condition for amenability of groups. We show that if G1 and G2 have the same configuration sets and H1 is a normal subgroup of G1 with abelian quotient, then there is a normal subgroup H2 of G2 such that [Formula: see text]. Also configuration of FC-groups and isomorphism is studied.
NOTES ON FINITE SIMPLE GROUPS WHOSE ORDERS HAVE THREE OR FOUR PRIME DIVISORS
Authors: ZHANG LIANGCAI , CHEN GUIYUN , CHEN SHUNMIN , LIU XUEFENG
Published: June 2009

Based on the prime graph of a finite group, its order can be divided into a product of some co-prime positive integers. These integers are called order components of this group. If there exist exactly k nonisomorphic finite groups with the same set of order components of a given finite group, we say that it is a k-recognizable group by its order component(s). In the present paper, we obtain that all finite simple Kn-groups (n = 3, 4) except U4(2) and A10can be uniquely determined by their order components. Moreover, U4(2) is 2-recognizable and A10is k-recognizable, where k denotes the number of all nonisomorphic classes of groups with the same order as A10. As a consequence of this result we can obtain some interesting corollaries.
LOOP RINGS SATISFYING IDENTITIES OF BOL–MOUFANG TYPE
Authors: DART BRADLEY C. , GOODAIRE EDGAR G.
Published: June 2009

The existence of loop rings that are not associative but which satisfy the Moufang or Bol identities is well known. Here we complete work started 25 years ago by establishing the existence of loop rings that satisfy any identity of "Bol–Moufang" type (without being associative). As it turns out, with one exception, loop rings satisfying an identity of Bol–Moufang type all satisfy a Moufang or Bol identity. We also highlight some similarities and differences in the consequences of several Bol–Moufang identities as they apply to loops and rings.
AUTO GENERATION OF THE CENTER OF GRAVITY OF TUBULAR STRUCTURES DURING CRUSH DEFORMATION
Authors: AFSHAR REZA , ALI AIDY , SAHARI B. B.
Published: June 2009

Displacement of the center of gravity (COG) of tubular structures with various polygonal cross-sections is numerically investigated under an axial crush using the program code of ANSYS/LS-DYNA. A subroutine is developed using this code to calculate the COG of the deformed shape, during and after the crush. The effect of wall thickness on displacement of the COG is also investigated. Displacement of the COG decreases as the number of edges increases; it is a reasonable symmetric-deformed shape for the number of edges beyond eight. An even number of edges leads to a more symmetric displacement of the COG. The effect of the number of polygonal edges on symmetric deformation of the COG becomes more prominent as the initial wall thickness decreases. The higher number of edges stabilizes the deformed shape and the value of the mass moment of inertia of the deformed shape about the y axis (Iyy). The value of the mass moment of inertia about the x–z axes (Ixz) in comparison with Iyy can be neglected in the case of dealing with an axial crush along the y direction.
ON A GENERALISED TRAPEZOIDAL RULE FOR FUNCTIONS OF BOUNDED VARIATION
Authors: Cerone P. , Dragomir S. S. , McAndrew A.
Published: June 2009

A generalised trapezoidal rule is considered. Error estimates for functions of bounded variation are given. Applications for some particular cases of interest are provided as well.
MATRIX UNITS FOR THE GROUP ALGEBRA kGf = k((ℤ2 × ℤ2) ≀ Sf)
Authors: Sivakumar B.
Published: June 2009

The irreducible representations of the group Gf := (ℤ2 × ℤ2) ≀ Sf are indexed by 4-partitions of f, i.e., by the set {[α]3[β]2[γ]1[δ]0|α ⊢ u3, β ⊢ u2, γ ⊢ u1, δ ⊢ u0, u0 + u1 + u2 + u3 = f}. This set is in 1 - 1 correspondence with partitions of 4f whose 4-core is empty. In this paper we construct the inequivalent irreducible representations of Gf. We also compute a complete set of seminormal matrix units for the group algebra kGf.
GROWTH OF MODULES OVER GENERIC GOLOD-SHAFAREVICH-ALGEBRAS
Authors: Smoktunowicz Agata
Published: June 2009

Let K be a field of infinite transcendence degree and let A be a finitely generated K-algebra. Suppose that the number of homogeneous generic relations in A of degrees smaller than n grows exponentially with n. Then all infinitely-dimensional finitely generated A-modules have exponential growth. In particular there are Golod-Shafarevich algebras all of whose finitely generated modules either have exponential growth or are finite-dimensional.
HARMONIC ANALYSIS OF THE LEBEDEV-STIELTJES INTEGRALS
Authors: YAKUBOVICH SEMYON B.
Published: June 2009

We expand the Bochner technique on the following Lebedev-Stieltjes integrals [Formula: see text] which are related to the Kontorovich-Lebedev transformation. Mapping and inversion properties are investigated. The Fourier type series with respect to an uncountable orthonormal system of the modified Bessel functions are considered in the Bohr type pre-Hilbert space. The Bessel inequality and Parseval equality are proved.
Geochronological evolution of HP metamorphic rocks of the Adula nappe, Central Alps, in pre-Alpine and Alpine subduction cycles
Authors: Liati Anthi , Gebauer Dieter , Fanning C.Mark
Published: June 2009

SHRIMP dating of zircon from eclogites, their country rock gneisses and quartz veins from the northern and middle Adula nappe, Central Alps, accompanied by cathodoluminescence imaging and REE geochemistry of these dated zircon crystals revealed that the Adula nappe has been affected by two pre-Alpine high-pressure (HP) metamorphic events (northern:
c
. 330–340 Ma; middle:
c
. 370 Ma). In the northern Adula nappe, loss of radiogenic Pb of the
c
. 330–340 Ma zircon domains in combination with previous geochronological data argue for an overprinting Alpine HP event. In the middle Adula nappe, metamorphic zircon domains record in addition a 33–32 Ma event, interpreted to reflect HT metamorphism, already identified in the southern part of the nappe, where such SHRIMP ages have been related to HT (Lepontine) metamorphism. The Alpine HP event indicated by previous SHRIMP data in the southern Adula nappe at
c
. 35 Ma is not recorded in the zircons of the rocks dated herein. The absence in this dataset is probably because either no HP (
c
. 35 Ma) zircon domains were formed or such domains were completely reset during the 33–32 Ma HT event. Protolith ages of orthogneisses and eclogites are 470–457 Ma and 595–587 Ma, respectively, and maximum sedimentation ages of paragneisses 500–460 Ma. The lack of Hercynian protolith zircon ages implies pre-Hercynian formation for the precursors of the dated HP rocks. Our data suggest that the Adula nappe contains various Hercynian basement slivers that underwent subduction to HP conditions at
c
. 330–340 Ma and
c
. 370 Ma prior to the Alpine orogeny, similar to many other parts of the Hercynian basement in Central and Southern Europe.

Supplementary material:

U, Pb and Th SHRIMP data and REE and trace element analyses are availaible at
http://www.geolsoc.org.uk/SUP18367
.
On the occurrence and boron isotopic composition of tourmaline in (ultra)high-pressure metamorphic rocks
Authors: Marschall Horst R. , Korsakov Andrey V. , Luvizotto George L. , Nasdala Lutz , Ludwig Thomas
Published: June 2009

The extensive
P–T
stability and the high chemical variability of tourmaline (Tur) together with its common occurrence in metasediments proves its high potential for petrological and (isotope) geochemical studies on fluid–rock interaction in subduction- and collision-related rocks. This paper reviews the occurrence, major element chemistry and boron isotopic composition of Tur in high- and ultrahigh-pressure metamorphic (UHPM) rocks. In addition, it presents a new discovery of coesite-bearing Tur (schorl) from the Erzgebirge (Germany), as well as Tur (dravite) related to the retrograde history of coesite- and diamond-bearing rocks from the Erzgebirge and the Kokchetav Massif (Kazakhstan). The scarce data on worldwide occurrences of (U)HPM Tur reveal a high occupation of the crystallographic X-site (dominated by Na) and the possible presence of excess B, with little further distinctiveness in its major element composition when compared with Tur from medium-grade rocks. High K
2
O contents in Tur are probably not related to UHP growth or equilibration. The B isotopic composition of (U)HPM Tur ranges in δ
11
B from −16 to +1‰, with many samples in or below the range of continental crust. In contrast, Tur formed during retrograde fluid influx typically shows high δ
11
B values (up to +28‰), suggesting heavy-B fluids infiltrating the exhuming (U)HPM units. Coesite inclusions in Tur, characterized by Raman spectroscopy, are regarded as the best indicator for its UHP stability.

Supplementary material:

Analytical methods, tourmaline compositions and boron isotope values are available at
http://www.geolsoc.org.uk/SUP18354
.
Isotope domain mapping of
87
Sr/
86
Sr biosphere variation on the Isle of Skye, Scotland
Authors: Evans J.A. , Montgomery J. , Wildman G.
Published: June 2009

The potential of
87
Sr/
86
Sr isotope composition for tracking and determining the origin of material, whether it is humans, animals, water or wine can be fully realized only if high-quality reference datasets are available against which to compare the unknowns. This is currently not the case. Despite the rapid increase in
87
Sr/
86
Sr-based provenance studies of biosphere materials there are no well-documented maps available. Most researchers resort to generating reference maps from a variety of geological datasets plus the analysis of sparse ’environmental' samples. A major reason for this lack of reference material is the investment needed to undertake systematic sampling and analysis over large areas. A further problem is associated with the choice of proxy material, as organisms differ in their habitat and exploitation of resources. In this paper various approaches to isotope biosphere sampling are considered, some of the problems are assessed, the precision required for the study of human populations is discussed, and a first attempt is made to condense all of the available information into an ’isotope package' map. The work is based on a study undertaken on the Isle of Skye, in the Inner Hebrides, and reduces the complexity of geological and isotope data into five main
87
Sr/
86
Sr packages: Package 1 (northern area) = 0.705–0.7092; Package 2 (NE coast) = 0.7082–0.7102; Package 3 (granitic rocks) = 0.716–0.720; Package 4 (metamorphic rocks) = 0.7092–0.7188; Package 5 (seawater) = 0.7092 ± 0.005% (2σ). The approach of trying to constrain the isotope composition of certain areas and/or lithologies offers the possibility of extrapolating to other similar areas without having to sample at the original density.
Petrogenesis of Sr-rich adakitic rocks at volcanic arcs: insights from global variations of eruptive style with plate convergence rates and surface heat flux
Authors: Zellmer Georg F.
Published: June 2009

Using global correlations of effusive eruption style with convergence rates and surface heat flux at volcanic arcs, this study identifies several arcs with excess surface heat flux, related to the presence of unusually hot and H
2
O-poor magmas. Geophysical evidence suggests that these melts are linked to discontinuities in the subducting slab, which would facilitate upwelling of hot sub-slab asthenospheric mantle. It is demonstrated that excess heat flux arcs are sites where Sr-rich adakitic compositions are generated, and that the arc proportion erupting Sr-rich adakitic magmas is directly proportional to the degree of observed heat flux excess. A model is presented in which the formation of Sr-rich adakitic compositions, which require garnet as a residual phase, is facilitated at excess heat flux arcs as a result of a decrease in H
2
O content through contributions from sub-slab asthenospheric mantle, leading to an expansion of the garnet stability field. Future geochemical, geophysical and experimental work required to test this model is addressed.
The Tiger Gabbro from northern Victoria Land, Antarctica: the roots of an island arc within the early Palaeozoic margin of Gondwana
Authors: Bracciali Laura , Di Vincenzo Gianfranco , Rocchi Sergio , Ghezzo Claudio
Published: June 2009

The Tiger Gabbro layered intrusion is one of the few mafic intrusive bodies found along the ancient Antarctic Gondwana margin. Major and trace element data and Sr–Nd isotope compositions for gabbronorites indicate an island arc signature for the Tiger Gabbro parental magma. This is the first evidence for an island arc from plutonic rocks in northern Victoria Land. The interpretation of the Tiger Gabbro as the roots of an Early Cambrian island arc (535 ± 21 Ma, Sm–Nd age), integrated with geochemical and geochronological data from the literature, matches the occurrence of the Glasgow volcanic rocks in the southern Bowers terrane, which possibly represents its effusive counterpart. A scenario for the early Palaeozoic Antarctic Gondwana margin is hence proposed in which the Tiger volcanic arc developed on the Robertson Bay microplate in response to subduction of the palaeo-Pacific plate. The Tiger arc igneous activity was coeval to the Wilson continental arc (represented by the Granite Harbour intrusive rocks), with the two subduction zones merging southwards into one. The migration of the Wilson arc towards the forearc region in turn generated the Middle Cambrian Bowers arc.

Supplementary material:

Major element, trace element, mineral and
40
Ar–
39
Ar data are available at
http://www.geolsoc.org.uk/SUP18351
.
The role of water in the evolution of the continental crust
Authors: Yardley Bruce W.D.
Published: June 2009

Aqueous fluids have a profound influence on the evolution of the crust, both as agents of chemical mass transfer and mineral reactions, and through modifying its rheology. This paper is particularly concerned with the composition and role of fluids through the crustal cycle of burial, metamorphism and uplift. Information now comes from both conventional geological studies and from geophysics, which has documented both the presence of fluid in active areas of the crust, and also its migration in response to faulting. This contrasts with the overall slow rate of some fluid processes: for example, devolatilization reactions are endothermic and limited by the rate of heat supply. There is no clear distinction between diagenetic and metamorphic fluids, and extensive equilibration with host rocks means that few chemical or isotopic characteristics survive to provide tracers for deep fluid origins. After the metamorphic peak, remaining pore fluid is consumed in hydration reactions resulting in strong, dry rock. Subsequently, infiltration may reintroduce fluids but these normally survive only briefly until consumed by hydration reactions. Metamorphic rocks are strongly overpressured during prograde metamorphism and therefore have a low permeability. Considerable doubt is therefore cast on some claims of widespread and pervasive large fluid fluxes accompanying metamorphism.
Cenozoic unroofing history of the Ladakh Batholith, western Himalaya, constrained by thermochronology and numerical modelling
Authors: Kirstein L.A. , Foeken J.P.T. , van der Beek P. , Stuart F.M. , Phillips R.J.
Published: June 2009

The Ladakh Batholith is part of the Transhimalayan Plutonic Belt, which crops out north of the Indus Suture Zone. We propose that the exhumation history of the Ladakh Batholith is linked to the tectonic, magmatic and erosion history of the Karakoram terrane and SW Tibet. We present new multiple low-temperature thermochronometry data (zircon (U–Th)/He, apatite fission-track and apatite (U–Th)/He) to gain insight into the cooling history of the Ladakh Batholith and recognize key periods in the evolution of the region. From the Indus Valley northwards the ages decrease across the batholith for all three thermochronometers applied. A model is proposed in which magmatism in the Ladakh Batholith ceased in the Late Eocene and initial denudation was driven by topographic uplift caused by collision. Southward tilting of the batholith occurred in the Late Palaeogene. This tilting resulted in an asymmetric topography with increasing elevation to the north. Strong erosion occurred in this northern region whereas the southern margin was affected by northwards thrusting of the Indus Molasse. For the first time, clear temporal and spatial variations in exhumation rate are identified in this region, highlighting why sampling strategy is critical in documenting exhumation changes in active tectonic settings.

Supplementary material:

Sample co-ordinates from the Ladakh Batholith, sample preparation and fission-track age measurements of apatite grains and grain size dimensions are available at
http://www.geolsoc.org.uk/SUP18350
.
Facies analysis and sea-level change at the Guadalupian–Lopingian Global Stratotype (Laibin, South China), and its bearing on the end-Guadalupian mass extinction
Authors: Wignall P.B. , Védrine S. , Bond D.P.G. , Wang W. , Lai X.-L. , Ali J.R. , Jiang H.-S.
Published: June 2009

The Guadalupian–Lopingian boundary stratotype at Penglaitan, and the nearby Tieqiao section, near Laibin, South China, record a series of major environmental changes within the Jiangnan Basin during a Mid-Permian biotic crisis. The sequence-stratigraphic, petrographic and palaeontological record of these sections has been studied and the associated strontium isotopic fluctuations have been assayed. Mass extinction of fusulinid foraminifers is most clearly associated in time with onset of volcanism and a relative sea-level fall that led to the establishment of mid-ramp conditions (Laibin Limestone) in settings that were previously dominated by radiolarian mudstones. The regression also coincides with a low point of
87
Sr/
86
Sr ratios. The lowstand deposits contain mafic scoriaceous grains that record pyroclastic volcanism probably centred in the Emeishan flood basalt province 800 km to the west of Laibin. Thus, unusually violent eruptions associated with flood basalts in this province may have contributed to the environmental stresses responsible for the extinction event. Subsequent environmental changes included transgression, spread of dysoxic waters, indicated by populations of small pyrite framboids, and a major negative C-isotope excursion. All these phenomena have been previously related to the end-Guadalupian extinction but they in fact post-date the crisis because a post-extinction fauna of foraminifers is encountered at this time.
Palaeoseismology of the Vilariça Segment of the Manteigas-Bragança Fault in northeastern Portugal
Authors: Rockwell Thomas , Fonseca João , Madden Chris , Dawson Tim , Owen Lewis A. , Vilanova Susana , Figueiredo Paula
Published: June 2009

The Manteigas-Bragança fault is a major, 250-km-long, NNE-striking, sinistral strike-slip structure in northern Portugal. This fault has no historical seismicity for large earthquakes, although it may have generated moderate (M5+) earthquakes in 1751 and 1858. Evidence of continued left horizontal displacement is shown by the presence of Cenozoic pull-apart basins as well as late Quaternary stream deflections. To investigate its recent slip history, a number of trenches were excavated at three sites along the Vilariça segment, north and south of the Douro River. At one site at Vale Meão winery, the occurrence of at least two and probably three events in the past 14.5 ka was determined, suggesting an average return period of about 5–7 ka. All three events appear to have occurred as a cluster in the interval between 14.5 and 11 ka, or shortly thereafter, suggesting a return period of less than 2 ka between events within the cluster. In the same area, a small offset rill suggests 2–2.5 m of slip in the most recent event and about 6.1 m after incision below ac. 16 ka alluvial fill event along the Douro River. At another site along the Vilariça River alluvial plain, NE of the Vale Meão site, several trenches were excavated in late Pleistocene and Holocene alluvium, and exposed the fault displacing channel deposits dated to between 18 and 23 ka. In a succession of closely spaced parallel cuts and trenches, the channel riser was traced into and across the fault to resolvec. 6.5 m of displacement after 18 ka andc. 9 m of slip afterc. 23 ka. These observations yield a slip rate of 0.3–0.5 mm/a, which is consistent with earlier estimates. Combining the information on timing at Vale Meão winery and displacement at Vilariça argues for earthquakes in the M7+ range, with coseismic displacements of 2–3 m. This demonstrates that there are potential seismic sources in Portugal that are not associated with the 1755 Lisbon earthquake or the Tagus Valley, and, although rare, large events on the Vilariça fault could be quite destructive for the region. This work provides an analogue for the study of active faulting in intracontinental settings and supports the view that earthquakes within intracontinental settings tend to cluster in time. In addition, this study highlights the usefulness and application of multiple field, remote sensing and geochronological techniques for seismic hazard mitigation.
Palaeoearthquake surface rupture in a transition zone from strike-slip to oblique-normal slip and its implications to seismic hazard, North Island Fault System, New Zealand
Authors: Mouslopoulou Vasiliki , Nicol Andrew , Little Timothy A. , Begg John G.
Published: June 2009

The North Island Fault System (NIFS) is the longest and highest slip-rate active strike-slip fault system within the Hikurangi subduction margin in New Zealand, accommodating up to 10 mm/a of the margin-parallel plate motion. Displacement of landforms over the last
c.
30 ka indicates a gradual northward change from right-lateral strike-slip to oblique-normal slip along the northern NIFS and within 60 km of its intersection with the active Taupo Rift. This change is expressed by a
c.
60° increase in the pitch of the slip vectors. We use fault data from 20 trenches and displacements along active traces to explore whether changes in late Quaternary fault kinematics principally arise due to earthquake rupture arrest and/or variations in slip vector pitch during individual earthquakes that span the kinematic transition zone. Results show that earthquake rupture arrest occurs along the strike of the NIFS, with at least 60–80% of all events during the last 10–13 ka terminating across the zone of late Quaternary (
c.
30 ka) transition from strike-slip to oblique-normal slip. The strike of the faults across the kinematic transition is unchanged, and we suggest that rupture was arrested there due to a 20–30° northward shallowing of fault-dip across this zone. Rupture arrest limits earthquake lengths and magnitudes which, when combined with recurrence intervals from trenching, locally decreases the seismic hazard in the region of the faults. Simple kinematic earthquake slip models, which simulate the addition of slip vectors during individual earthquakes, suggest that rupture arrest was accompanied by a northward steepening of slip vectors during individual earthquakes. Changes in coseismic slip vectors may arise due to the northward decrease in fault dip and associated steepening of the principal compressive stress axis (σ
1
) which, in turn, is due to fault interactions between the NIFS and the adjacent active Taupo Rift.
Advances and limitations of the Environmental Seismic Intensity scale (ESI 2007) regarding near-field and far-field effects from recent earthquakes in Greece: implications for the seismic hazard assessment
Authors: Papanikolaou I. D. , Papanikolaou D. I. , Lekkas E. L.
Published: June 2009

The new Environmental Seismic Intensity scale (ESI 2007), introduced by INQUA, incorporates the advances and achievements of palaeoseismology and earthquake geology and evaluates earthquake size and epicentre solely from the earthquake environmental effects (EEE). This scale is tested and compared with traditional existing scales for the 1981 Alkyonides earthquake sequence in the Corinth Gulf (Ms=6.7, Ms=6.4, Ms=6.3), the 1993 Pyrgos event (Ms=5.5) and the 2006 Kythira event (Mw=6.7). These earthquakes were of different magnitudes, focal mechanisms and focal depths and produced well-documented environmental effects. The ESI 2007 intensity values and the isoseismal pattern for the 1993 Pyrgos and the 2006 Kythira events are similar to those resulting from the traditional scales, demonstrating that for moderate intensity levels (VII and VIII) the ESI 2007 and the traditional scales comply well. In contrast, the 1981 Alkyonides earthquake sequence shows that there is an inconsistency between the ESI 2007 and the traditional scales both in the epicentral area, where higher ESI 2007 intensity values have been assigned, and for the far‐field effects. The ESI 2007 scale offers higher objectivity in the process of assessing macroseismic intensities, particularly in the epicentral area, than traditional intensity scales that are influenced by human parameters. The ESI 2007 scale follows the same criteria–environmental effects for all events and can compare not only events from different settings, but also contemporary and future earthquakes with historical events. A reappraisal of historical earthquakes so as to constrain the ESI 2007 scale may prove beneficial for seismic hazard assessment by reducing the uncertainty implied in the attenuation laws, which constitute one of the most important seismic hazard parameters.
Application of INQUA Environmental Seismic Intensity Scale to recent earthquakes in Japan and Taiwan
Authors: Ota Yoko , Azuma Takashi , Lin Yu-nong Nina
Published: June 2009

The INQUA Environmental Seismic intensity scale (ESI 2007 scale) is a new seismic intensity scale proposed by the Subcommission on Palaeoseismology, INQUA, based on seismically induced ground effects. This intensity scale is expected to be useful for evaluation of detailed areal distribution of seismic intensity and also for the evaluation of intensity of palaeoearthquakes. We selected four great earthquakes to map ESI 2007 scale distribution: the 1995 Kobe; the 2004 Chuetsu, Japan; the 1935 Hsinchu-Taichung; and the 1999 Chichi, Taiwan. Proposed ESI 2007 scale maps from these areas are the mesh maps with a grid of about 1 km
2
, showing more detailed intensity patterns than those previously provided by the Japan Meteorological Agency and the Central Weather Bureau for the four areas. Different responses of ground effects to the earthquakes, depending on local differences of geological materials near the surface and morphological condition of each site, are more clearly expressed by the ESI 2007 scale map, because of the large number of observed sites by the evaluation of ESI 2007 scale. Calibration exercise also reveals, however, that the classification of ESI 2007 scale needs some improvement.