bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth Inhibitory Concentrations of Androgens Up-Regulate Insulin-Like Growth Factor Binding Protein-3 Expression via an Androgen Response Element in LNCaP Human Prostate Cancer Cells
Authors: Peng Lihong , Malloy Peter J. , Wang Jining , Feldman David
Published: July 2006

IGF binding protein-3 (IGFBP-3), the most abundant circulating IGF binding protein, inhibits cell growth and induces apoptosis by both IGF-I-dependent and -independent pathways. The ability of IGFBP-3 to inhibit tumor growth has been demonstrated in many cancers including prostate cancer (PCa). High concentrations of androgens, which inhibit the growth of the LNCaP human PCa cell line, have been shown to have both positive and negative effects on IGFBP-3 expression by different laboratories. To further explore the relationship between IGFBP-3 and androgens, we examined IGFBP-3 expression in LNCaP cells. We demonstrate that IGFBP-3 expression can be induced by 10 nm of the synthetic androgen R1881 or dihydrotestosterone. Transactivation assays show that the 6-kb IGFBP-3 promoter sequence directly responds to androgen treatment. In silico analysis identified a putative androgen response element (ARE) at −2879/−2865 in the IGFBP-3 promoter. A single point mutation in this ARE disrupted transactivation by R1881. Combining the data obtained from EMSA, chromatin immunoprecipitation and mutational analysis, we conclude that a novel functional ARE is present in the IGFBP-3 promoter that directly mediates androgen induction of IGFBP-3 expression. Furthermore, we found that the combination of androgens and calcitriol significantly potentiated the IGFBP-3 promoter activity, suggesting that enhanced induction of the expression of the endogenous IGFBP-3 gene may contribute to the greater inhibition of LNCaP cell growth by combined calcitriol and androgens. Because androgens are well known to stimulate PCa growth and androgen deprivation therapy causes PCa to regress, the stimulation by androgens of this antiproliferative and proapoptotic protein is paradoxical and raises interesting questions about the role of androgen-stimulated IGFBP-3 in PCa.
Estrogen Up-Regulates Mismatch Repair Activity in Normal and Malignant Endometrial Glandular Cells
Authors: Miyamoto Tsutomu , Shiozawa Tanri , Kashima Hiroyasu , Feng Yu-Zhen , Suzuki Akihisa , Kurai Miyuki , Nikaido Toshio , Konishi Ikuo
Published: July 2006

Impaired mismatch repair (MMR) is reportedly crucial in the early stages of endometrial carcinogenesis. Although estrogen exposure is considered an important risk factor for endometrial carcinoma, the relationship between estrogen and MMR activity remains undetermined. The present study was undertaken to elucidate the effect of estrogen on MMR activity in normal and malignant endometrial cells. The expression of MMR proteins, hMLH1 and hMSH2, and its correlation with estrogen was examined using immunohistochemical and immunofluorescent techniques. The effect of estradiol (E2) on the expression of hMLH1/hMSH2 protein/mRNA and in vitro MMR activity using two types of heteroduplex (G/T mismatches, 2-base insertion-deletion loops) was examined in cultured normal endometrial glandular cells and estrogen receptor-positive endometrial carcinoma Ishikawa cells. Immunohistochemical expression of hMLH1 and hMSH2 in normal endometrial glands was positively correlated with the serum E2 levels. The expression of hMLH1/hMSH2 protein and mRNA was increased in normal endometrial glandular and Ishikawa cells by E2 treatment. In vitro MMR activity was up-regulated by E2 in both types of cell and heteroduplex. Immunofluorescent analysis demonstrated that E2 enhanced proliferation and hMLH1/hMSH2 expression in both cells; however, proliferating cells without hMLH1/hMSH2 expressions implying high-risk cells were more frequently observed under low E2 concentrations. Collectively, the E2-induced up-regulation of MMR activity in endometrial cells suggests that high estrogen levels act as an intrinsic defense against endometrial carcinogenesis, whereas the imbalance between cell growth and MMR under low E2 environment as seen at postmenopause is vulnerable to carcinogenesis.
Inhibition of Growth Hormone Receptor Gene Expression by Saturated Fatty Acids: Role of Krüppel-Like Zinc Finger Factor, ZBP-89
Authors: Thimmarayappa Jamuna , Sun Jinhong , Schultz Laura E. , Dejkhamron Prapai , Lu Chunxia , Giallongo Agata , Merchant Juanita L. , Menon Ram K.
Published: July 2006

The expression and function of the GH receptor is critical for the actions of pituitary GH in the intact animal. The role of systemic factors in the reduced expression of the GH receptor and consequent GH insensitivity in pathological states such as sepsis, malnutrition, and poorly controlled diabetes mellitus is unclear. In the current study, we demonstrate that saturated (palmitic and myristic; 50 μm) fatty acids (FA) inhibit activity of the promoter of the major (L2) transcript of the GH receptor gene; unsaturated (oleic and linoleic) FA (200 μm) do not alter activity of the promoter. Comparable effects with palmitic acid and the nonmetabolizable analog bromo-palmitic acid, and failure of triacsin C to abrogate palmitic acids effects on GH receptor expression indicate that this effect is due to direct action(s) of FA. Palmitic acid, but not the unsaturated FA linoleic acid, decreased steady-state levels of endogenous L2 mRNA and GHR protein in 3T3-L1 preadipocytes. The effect of FA was localized to two cis elements located approximately 600 bp apart on the L2 promoter. EMSA and chromatin immunoprecipitation assays established that both these cis elements bind the Krüppel-type zinc finger transcription factor, ZBP-89. Ectopic expression of ZBP-89 amplified the inhibitory effect of FA on L2 promoter activity and on steady-state levels of endogenous L2 mRNA in 3T3-L1 preadipocytes. Mutational analyses of the two ZBP-89 binding sites revealed that both the sites are essential for palmitic acid’s inhibitory effect on the L2 promoter and for the enhancing effect of ZBP-89 on palmitic acid-induced inhibition of the L2 promoter. Our results establish a molecular basis for FA-induced inhibition of GH receptor gene expression in the pathogenesis of acquired GH insensitivity in pathological states such as poorly controlled diabetes mellitus and small for gestational age.
Predictive Traffic Regulation for Metro Loop Lines Based on Quadratic Programming
Authors: Fernandez A , Cucala A P , Vitoriano B , de Cuadra F
Published: July 2006

This article proposes a predictive traffic regulation model for metro loop lines on the basis of the optimization of a cost function along a time horizon. The regulation strategies typically compensate timetable and headway deviations modifying the train run times. The existing optimization methods are based on simplified traffic models with analytical solutions or based on more realistic models (usually non-linear) that have real-time computational limitations. A quadratic programming model is proposed here, suitable to include in an efficient way the main operation constraints: minimum interval, limits in the control actions, and the typical operation criterion of preventing the actuation of signalling systems between platforms. Efficiency is measured by the computing time required to solve long-term predictive models with standard optimization tools. Long-term prediction improves regulation performance and stability and simplifies the tuning of regulation parameters according to the operation requirements. The use of standard optimization tools improves the implementation of the proposed regulator and its maintainability. Although the proposed method is valid for both timetable and headway operation, the analysis in the article is focused on headway operation. In this case, it is possible to observe the offered commercial speed and to adjust the quality criteria that will measure the performance of the headway operation.
Evaluation of Maintenance Schedules on Railway Traction Power Systems
Authors: Ho T K , Chi Y L , Ferreira L , Leung K K , Siu L K
Published: July 2006

In electrified railways, the traction power systems carry power to trains and their reliability is vital to the quality of train services. There are many components in the traction power system, from interface with utility distribution network to contacts with trains, and they are physically located along the rail line. Subject to usage, environment, and ageing, conditions of components deteriorate with time. Regular maintenance has to be carried out to restore their conditions and prevent them from failure. However, the decisions on the suitable length of maintenance intervals often lead railway operators to the dilemma of minimizing both risk of failure and operation cost. On the basis of a stochastic lifetime model, this article presents a generic software evaluation tool that enables the operators to manage risk of failure and cost quantitatively in order to match their preferred levels of service quality. The lifetime model includes the effects of condition restoration because of maintenance of regular intervals and ageing acceleration because of electrical stress from traffic demands. Examples of simulation results are given to illustrate the applicability of this lifetime model.
Assessing the Economic Life of Rail Using a Stochastic Analysis of Failures
Authors: Zhao J , Chan A H C , Roberts C , Stirling A B
Published: July 2006

In this article, a model is developed to evaluate the economic life of rail using a stochastic analysis of rail failures. The occurrence of rail defects and failures is analysed and issues related to rail maintenance are addressed. The hazard rate of alumino-thermic weld failures is predicted for continuously welded rail, where the expected number of welds is increasing in tonnage as a result of replacement. Imperfect inspections are modelled for predicting the expected number of failures by employing a filtered non-homogeneous Poisson process. The impact of maintenance on failure occurrence and whole life-cycle cost (LCC) is analysed and integrated within the model. The application and capability of the proposed model and sensitivity of parameters are illustrated through the use of a practical example. It is shown that an optimal economic life of rail can always be found, as the repair cost and the risk cost of accident are increasing with tonnage that passed through it. In addition, the inspection frequency has a significant impact on rail LCC. The results also suggest that the proposed model is also valid for optimizing the interval between rail inspections.
A Systemic Analysis of the Paddington Railway Accident
Authors: Santos-Reyes J , Beard A N
Published: July 2006

The Paddington railway collision may be regarded as the most serious railway accident on Britain's railway system. The accident occurred on 5 October 1999. Thirty-one people were killed and many more were injured. An immediate and ‘direct’ cause of the collision was the fact that a train that belonged to Thames Trains had passed a signal at red and collided with a First Great Western High Speed Train at Ladbroke Grove Junction, near Paddington, London. Following this and several other accidents that have occurred since privatization of the railways (1994), there has been a large amount of public debate about safety management on the British railways. This article presents the results of a preliminary systemic analysis of the accident. The approach has been to compare the features of the Paddington railway accident with the characteristics of a railway systemic safety management system model, which has been constructed employing the concepts of systems. A number of discrepancies have come to light. Further analysis would be expected to reveal more. It is hoped that this systemic analysis will help to identify ‘learning points’, which are relevant for preventing accidents on the railways.
Three-Dimensional Non-Newtonian Lubricants Flows in Sector-Shaped, Tilting-Pads Thrust Bearings
Authors: Bouyahia F , Hajjam M , Khlifi M El , Souchet D
Published: July 2006

The authors developed a numerical study to predict the influence of non-Newtonian character of incompressible lubricants on the operation of hydrodynamic thrust bearings. The chosen rheological models are the Power law (pseudo-plastic behaviour), the Bingham, and the Herschel-Bulkley (viscoplastic behaviour). The mathematical model is based on the solution of a generalized Reynolds equation established using the concept of Generalized Newtonian Fluids. The temperature effect is taken into account through the resolution of energy equation in the film and Laplace's equation in the pad. The evolution of pressure and temperature fields, according to the characteristics of non-Newtonian lubricants, is analysed. Load capacity, friction torque, and power loss are also calculated as interesting parameters from an industrial point of view.
Comparison of Two Types of Deflection Functions for Analysing the Responses of the Rail and the Bridge under Static or Moving Vehicles
Authors: Lou P
Published: July 2006

The interaction model consisting of a train, a two-layer railway track, and a railway bridge is presented for an analysis of the responses of the rail and the bridge, and two types of deflection functions are compared. One type is the shape functions of a beam element described by the cubic Hermitian interpolation functions in the finite-element method (FEM), and the other is the deflection of a beam described by the superimposing modes in the modal analysis method (MAM). In the present model, each vehicle is modelled as a two-wheel mass-spring-damping system with four degrees of freedom (DOFs); the track is modelled as a discrete supported undamped uniform Bernoulli-Euler beam with hinged-hinged ends representing rails, discrete lumped masses representing sleepers, and discrete massless springs and dashpots representing the characteristics of pads and ballasts; and the bridge deck is modelled as a simply supported uniform Bernoulli-Euler beam. Two different equations of motion for the present model with two types of deflection functions for the rail and the bridge deck are derived from the energy principle. These equations can be easily degenerated into the equations of either a train-track or train-bridge interaction system. Numerical results show that the difference between the two types of deflection functions to analyse the responses of the bridge is very small; and FEM can, yet MAM cannot, give an acceptable result if the bending moment of the rail is taken into account.
Fatty Acid Analysis of Archaeological Pottery Vessels Excavated in Tell Mastuma, Syria
Authors: Shimoyama Akira , Kisu Naoko , Harada Kaoru , Wakita Shigeo , Tsuneki Akira , Iwasaki Takuya
Published: July 2006

Fatty acids extracted from archaeological pottery vessels (B.C. 900—720 y) excavated at Tell Mastuma, Syria, are characteristic of individual vessels. The molecular-distribution patterns of n-fatty acids of these vessels are different from those of the underfloor soil and a human hand, indicating that the fatty acids recovered are proper to the samples. The lamps show a predominance of hexadecanoic and octadecanoic acids with a near absence of other acids in the patterns, suggesting that olive oil was used in the lamps. On the other hand, large pottery jars show a clear presence of nonanoic acid in their patterns. The acid presence is also strikingly noted in carbonized olive, suggesting that olive and/or a chemically olive-related material was stored in the jars. The relative concentration of cis-9-octadecenoic acid to octadecanoic acid decreases drastically from modern olive pulp to carbonized olive, and further in the jars and lamps. Apparently, a degradation of the acid had occurred intensely during burial in the soil. A comparison of the molecular-distribution patterns of the jars and lamps to the carbonized olive and olive pulp allows one to conclude that olive and its oil were commonly utilized at the tell.
Tris(pentafluorophenyl)boron as an Efficient, Air Stable, and Water Tolerant Lewis Acid Catalyst
Authors: Ishihara Kazuaki , Hanaki Naoyuki , Funahashi Miyuki , Miyata Mayumi , Yamamoto Hisashi
Published: July 2006

Tris(pentafluorophenyl)boron is an efficient, air stable, and water tolerant Lewis acid catalyst for the aldol-type and Michael reactions of silyl enol ethers with carbonyl compounds or other electrophiles (trimethyl orthoformate, dimethyl acetal, and chloromethyl methyl ether), the allylation reaction of allylsilanes with aldehydes, and the Diels–Alder reaction of dienes with α,β-unsaturated aldehydes. A solution of formaldehyde in water is applicable as an electrophile. Also, the aldol-type reaction of ketene silyl acetals with aromatic or aliphatic imines is successfully carried out using the same catalyst.
An Investigation into the Current Peri-Operative Nutritional Management of Oesophageal Carcinoma Patients in Major Carcinoma Centres in England
Authors: Murphy PM , Modi P , Rahamim J , Wheatley T , Lewis SJ
Published: July 2006

INTRODUCTION

Patients with oesophageal carcinoma are at high risk of malnutrition. The aim of this study was to assess current practice for the nutritional management of patients following surgery for oesophageal carcinoma.

PATIENTS AND METHODS

A postal questionnaire was sent to 82 dietetic departments of those hospitals in England identified as major centres for upper gastrointestinal surgery.

RESULTS

Of the 66 (80%) responses received, 22 (33%) centres routinely perform pre-operative nutritional screening/assessment on oesophageal carcinoma patients. Centres with dietetic support dedicated to these patients are more likely to perform a pre-operative nutritional assessment (n = 17; 55%) than those without (n = 5; 14%; P < 0.001; χ2 = 12.17). Pre-operative nutritional support is routinely provided in only 11 (17%) centres with the majority of centres (n = 50; 75%), providing it if patients are considered malnourished only. A total of 47 (70%) centres routinely provide postoperative nutritional support with jejunal feeding being the most commonly chosen route. Dedicated dietetic support is provided at 31 (47%) centres. Those centres with a dedicated dietitian are more likely to provide early postoperative nutritional support (n = 27; 87%) than those without (n = 20; 57%; P = 0.007; χ2 = 7.195) and more likely to review patients routinely following discharge from hospital (n = 25 [81%] with a dietitian versus n = 17 [49%] without; P = 0.007; χ2 = 7.2).

CONCLUSIONS

The nutritional management of patients following surgery for upper gastrointestinal carcinoma is not uniform with practice varying considerably between centres. Those centres with a dedicated dietitian are more likely to assess patients’ nutritional status and provide nutritional support.
Can a Urinary Tract Symptom Score Predict the Development of Postoperative Urinary Retention in Patients Undergoing Lower Limb Arthroplasty Under Spinal Anaesthesia? A Prospective Study
Authors: Sarasin SM , Walton MJ , Singh HP , Clark DI
Published: July 2006

INTRODUCTION

There is no general consensus amongst orthopaedic surgeons on how best to manage the urinary tract and its complications after lower limb arthroplasty. This prospective audit investigates whether postoperative urinary retention can be predicted pre-operatively using the validated International Prostate Symptom Severity score (IPSS).

PATIENTS AND METHODS

A total of 182 patients undergoing lower limb arthroplasty under spinal anaesthetic were given the IPSS questionnaire to complete pre-operatively and an audit into numbers catheterised postoperatively was performed.

RESULTS

Overall, 69% of males and 39% of females required catheterisation. Following logistic regression analysis there was 0.85 predicted probability that males over 70 years would require catheterisation. The IPSS score was not useful in predicting retention in either sex at any age.

CONCLUSIONS

We propose that all males over 70 years undergoing this type of surgery should be catheterised pre-operatively and all other patients should be catheterised postoperatively with close monitoring of bladder volumes to prevent established urinary retention.
Nurse-Led Management of Carpal Tunnel Syndrome: An Audit of Outcomes and Impact on Waiting Times
Authors: Newey Martyn , Clarke Malcolm , Green Tim , Kershaw Christopher , Pathak Pankaj
Published: July 2006

INTRODUCTION

This article describes the outcome of a nurse-led service developed to manage patients referred with a presumptive diagnosis of carpal tunnel syndrome.

PATIENTS AND METHODS

We developed a rapid-access service in response to unacceptable waiting times for patients with carpal tunnel syndrome. The service was developed around the role of a nurse practitioner providing a single practitioner pathway from first clinic appointment, through surgery to discharge.

RESULTS

Waiting times improved considerably whilst the standard and quality of care was maintained.

CONCLUSIONS

There is a role for nurses to perform certain surgical procedures within a well-defined environment.
Quality of Surgical Instruments
Authors: Brophy T , Srodon PD , Briggs C , Barry P , Steatham J , Birch MJ
Published: July 2006

INTRODUCTION

Many surgeons will have encountered the scissors that would not cut, and the artery clip that comes off in a deep difficult location, but it would be reasonable to assume that new instruments should be of assured quality. This study reports the surprising findings of a local quality control exercise for new instruments supplied to a single trust.

MATERIALS AND METHODS

Between January 2004 and June 2004, all batches of new surgical instruments ordered by the Central Sterile Supplies Department of St Bartholomew's and the Royal London Hospitals were assessed by three clinical engineers, with reference to British Standards (BS) requirements.

RESULTS

Of 4800 instruments examined, 15% had potential problems. These included 116 with machining burrs and debris in the teeth of the tissue-holding regions, 71 defects of ratcheted instruments, 34 scissors with deficient cutting action, and 35 tissue forceps protruding guide pins. In addition, 254 instruments did not have a visible manufacturer's mark.

CONCLUSIONS

This study demonstrates the value of local quality control for surgical instruments. This is of importance in an increasingly hazard-conscious environment, where there are concerns over instrument sterilisation, surgical glove puncture and the potential for transmission of blood-borne and prion diseases.
Informing Research in Primary Dental Care: Setting Priorities
Authors: Palmer Nikolaus , Batchelor Paul
Published: July 2006

This paper suggests that priorities for research in primary dental care should follow the examples set in other areas of primary healthcare. It reviews the history of research in primary dental care, since 1990, and goes on to explain how the Delphi exercise, initiated by the Faculty of General Dental Practice (UK), has identified five priority areas for research in primary dental care. These areas are:

1. Research into the application of evidence-based dentistry into practice.

2. The effects of different systems of remuneration on treatment patterns in practice.

3. The oral health assessment on determining recall intervals and its effect on oral health.

4. Factors that influence and affect dentists’ treatment modalities.

5. The evaluation of the cost benefits of whole team training.
Faculty of General Dental Practice (UK) Diplomates Day 2006
Authors: Franklin Christopher , Grieveson Brian , Jenner Anthony , Ward Nicholas , Brunton Paul , Chan Eugene , Howard Paul , Leung David , Eaton Kenneth A.
Published: July 2006

On Saturday, 25th February 2006, the Faculty of General Dental Practice (UK) hosted its annual ceremony of presentation of Diplomates. A total of 90 individuals received Diplomas in a packed Edward Lumley Hall at The Royal College of Surgeons of England.
An Audit of the Quality and Content of Periodontal Referrals and the Effect of Implementing Referral Criteria
Authors: Kourkouta Styliani , Darbar Ulpee R
Published: July 2006

Aims

This audit aimed to assess the effect of implementing referral criteria on the quality and content of referral letters sent by general dental practitioners (GDPs) to the periodontal department of a teaching hospital.

Methods

Retrospective data were collected from a total of 450 referrals made in: (i) 1997, prior to any changes; (ii) 2000/2001, after referral guidelines were implemented; and (iii) 2004/2005, after referral criteria were redefined and circulated via Primary Care Trusts. A standardised data-collection form was used to record the information that was provided in the referral letters. This information was also compared to the findings at initial hospital consultations.

Results

There was a small improvement in the administrative details provided in the referral communications in 2000/2001 and 2004/2005. Medical history was often incomplete and was mentioned in 31–34% of referral letters. Use of the Basic Periodontal Examination (BPE) score increased from 17% (1997) to 57% (2004/2005). The information on clinical details otherwise increased in 2000/2001 with a tendency to decrease in 2004/2005. There was little agreement between the clinical details in the referral communications and the findings at consultation in the periodontal department.

Conclusions

Following implementation of referral criteria, there was an increase in the clinical details provided in referral letters. However, the validity of the information provided by the GDPs was often questionable. The number of referrals that provided medical history details remained unchanged. Use of a pro forma was not associated with an improvement in the quality of referrals in this audit.
Entwurfsmethode für den verallgemeinerten virtuellen Aktor zur Rekonfiguration von Regelkreisen (Design Approach to the Generalised Virtual Actuator for Control Reconfiguration)
Authors: Lunze Jan , Richter Jan H.
Published: July 2006

Dieser Beitrag stellt eine neue Methode zur Rekonfiguration linearer Regelungen nach Aktorfehlern vor. Er beschreibt eine Erweiterung des verallgemeinerten virtuellen Aktors zur bestmöglichen statischen Ausnutzung gegebener Redundanzen bei maximaler Nutzung seines schnelleren statischen Anteils. Dazu wird der Begriff der statischen E/A-Rekonfigurierbarkeit unter Verwendung der Markov-Parameter eingeführt. Die Vorgehensweise wird anhand eines Beispiels gezeigt.
Fritz H. Laves – 100 years young
Authors: Parthé Erwin
Published: July 2006

This year Fritz Laves, professor for crystallography and petrography and head of the Mineralogical Department at the University and the Eidgenössische Technische Hochschule in Zurich from 1954 to 1976, an accomplished leading scientist and outstanding pioneer in crystal chemistry, would be 100 years old.
Fritz H. Laves – an ideal for generations
Authors: Fischer Werner
Published: July 2006

Fritz Laves' 100th birthday is an excellent reason to recollect his merits for the German and the international crystallography in general. This, however, would be a task too difficult for me though I consider myself a scientific grandson of him. Laves' crystallographic oeuvre (cf. Hellner, 1980) is almost too comprehensive to be valued by a single person of my generation. Accordingly, I will confine myself mainly on our common field of interest, i.e. on Mathematical Crystallography.
Gustav E. R. Schulze's pioneering work on Laves phases
Authors: Paufler Peter
Published: July 2006

There are several reasons to recollect the merits of Gustav Ernst Robert Schulze on the occasion of Fritz Laves' anniversary. Firstly, he had been a good friend of Laves and shared his interest in intermetallic compounds. Secondly, his work on Laves phases, though containing important early results, is less well known for some reasons. Thirdly, Schulze was the founder of a very efficient research centre on intermetallics in Dresden which is still active today. Finally, he introduced Metal Physics at the TU Dresden as a broad subject of bringing together structure and properties of the metallic state from a more fundamental point of view. Later on, this had a clustering effect for the development of materials research institutes in Dresden.
Atomic ordering in the Laves phases L1 V(Co1–xSix)2 (x = 0.43 and 0.56)
Authors: Conrad Matthias , Pohling Christoph , Webert Holger , Harbrecht Bernd
Published: July 2006

The synthesis, phase relations, and crystal structures of two truly ternary, partially ordered Laves phases occurring in the V—Co—Si system are reported. The phases termed L1 V(Co1–xSix)2 are found in two distinct phase fields next to TiMnSi-type VCoSi. This so-called E-phase emerges in the centre of the miscibility gap which separates the Co- and Si-rich Laves phase fields. Both fields accommodate several structurally distinct L-phases. The L1-phases V(Co1–xSix)2 (x = 0.43 and 0.56) crystallise in √3a × √3a superstructures of the hexagonal MgZn2 structure type. A rigorous symmetry-based analysis reveals that, at the given compositions, this type of superstructure affords sufficient structural degrees of freedom for ordering of Co and Si atoms on 4 different sites in a manner that enables tuning of hetero-atomic Co—Si interactions to an optimum.
Microscopic structures of Laves phases and structurally related compounds: a transmission electron microscopy study
Authors: Yokosawa Tadahiro , Söderberg Karin , Boström Magnus , Grüner Daniel , Kreiner Guido , Terasaki Osamu
Published: July 2006

We present microstructural investigations of Laves phases AB2 and structurally related compounds using transmission electron microscopy. Convergent-beam electron diffration in combination with selected-area diffraction has been used to determine uniquely the space group symmetry of the respective phases from very small illuminated regions. In addition stacking faults, domain boundaries, and intergrowth have been studied by HREM images. By electron beam irradiation intermetallic phases have been transformed in-situ into phases of different compositions. Polar intermetallic phases in the systems Ca—Al—Zn, Ba—Al and Ba—Al—Zn, as well as transition metal based Nb-Co phases have been chosen for this case study. In the Ca—Al—Zn system, the C15- and C36-type crystals did not show orderliness but a randomly mixed occupation of the B-net by Al and Zn atoms. Starting from C36, a C15 phase of constant Ca and lower Zn content as well as a new C36 phase with higher Ca content could be synthesized by means of electron beam irradiation. In the case of CaAlZn no ordering of Al and Zn were observed, i.e., Al and Zn randomly mixed occupy the Cu-site in the CeCu2 structure type. By electron beam irradiation of CaAlZn, a novel hexagonal phase with a hitherto unknown crystal structure is formed. The crystal structures of Ba21Al40 and Ba14Al22+xZn5–x are derived from Laves-type structures by omitting and modifying some of the triangular and Kagom, layers. In the case of Ba21Al40, intergrowth of motifs from the crystal structures of Ba3Al5 and Ba4Al5 were observed, whereas for Ba14Al22+xZn5–x the bulk phase displays a domain structure. Adjacent domains are misoriented by ∼120°, the specific angle resulting from the pseudo-trigonal symmetry of the Ba-net. Therefore, only the (Al,Zn)-net is disordered. No superstructure formation were detected for the three polytypes C36, C15 and C14 in the Nb—Co system. However, TEM images of C36-Nb1–xCo2+x reveal a high stacking fault density with intergrowth of stacks of C36 and C15 sequence. When the C15 phase is rich in Nb, stacking faults seem to be more important than for Co-rich C15 phases, whereas stacking faults have seldom been observed for the Co-rich C14 phase.
Crystal growth and magnetic properties of rare earth borosilicides
Authors: Mori Takao
Published: July 2006

B12 icosahedra cluster-containing rare earth borosilicides REB44Si2 (RE = Tb, Dy, Ho, Er, Tm, Yb) were grown by the floating zone method and their physical properties were investigated. REB44Si2 compounds are isostructural to REB50 and they are unique among the newly discovered boron-rich phases in that it is possible to grow large crystals with dimensions exceeding 10 mm. The rare earth atoms form a coupled chain structure like a ladder along the c-axis which is also the axis along which there is a B12 icosahedral chain. Magnetic properties, resistivity, and specific heat of the compounds were investigated. The conductivity follows the 3D variable range hopping mechanism and it was determined that localization lengths ξ are extremely short, actually close to the distances of the atoms themselves. Magnetic transitions above 4 K are indicated for all the compounds except for TmB44Si2 and it is found that specific heat measurement is the expedient probe of such compounds in which the low temperature susceptibility is influenced by external conditions such as crystal growth rate. Despite dimer-like features to the magnetic transition a spin gap is not observed. The magnetic coupling in these systems is indicated to be different from the conventional mechanisms in f-electron systems of dipole-dipole coupling or RKKY interaction.
Structure refinements of iron borides Fe2B and FeB
Authors: Kapfenberger Christine , Albert Barbara , Pöttgen Rainer , Huppertz Hubert
Published: July 2006

Crystals of the iron borides FeB and Fe2B were obtained from two different high temperature synthesis routes, viz. in combined copper/gallium flux and under high pressure conditions. Their crystal structures were investigated at room and low temperatures. Structure models from the literature were confirmed. The position of the boron atoms was unambiguously determined. FeB (Pnma, no. 62) contains zig-zag chains of boron atoms in which the boron atoms are coordinated by seven iron atoms in the form of a mono-capped trigonal prism. Fe2B (I4/mcm, no. 140) contains single boron atoms in a square antiprismatic iron atom coordination.
Filling the CoSn host-cell: the HfFe6Ge6-type and the related structures
Authors: Venturini Gerard
Published: July 2006

The crystallographic properties of the CoSn-based MT6X6 compounds (M = alkaline-, alkaline earth-, transition metals, lanthanides and actinides, T = transition metal, X = element of the main group) are reported. The filling scheme and the features of the diffraction patterns are detailed and illustrated by the new LuFe6Ge6–xGax series. The members of the hexagonal, orthorhombic and monoclinic series are presented. The crystal chemistry and the structural evolutions as a function of the size of the components and of the valence electron concentration are reported.
Synthesis and characterization of Na2Ba4Ga2Sb6 and Li13Ba8GaSb12
Authors: Todorov Iliya , Sevov Slavi C.
Published: July 2006

The title compounds were synthesized from the elements by heating the corresponding stoichiometric mixtures at high temperature. Their structures were determined from single-crystal X-ray diffraction. Na2Ba4Ga2Sb6 (Pnma, Z = 8, a = 12.3468(10) Å, b = 10.6621(10) Å, c = 13.8344(10) Å) contains chains of ∞[Ga2Sb6]10–. The repeating unit is made of an edge-sharing Ga-centered tetrahedron GaSb2(μ-Sb)2 and another Ga-centered tetrahedron but with additional antimony that is exo-bonded to one of the corners forming Sb–Sb dumbells, i.e. GaSb(Sb–Sb)(μ-Sb)2. The unit connects to neighboring units via sharing two corners of the tetrahedra, i.e. [Ga2Sb5Sb2/2]. Li13Ba8GaSb12 (C2/m, Z = 2, a = 18.0650(10) Å, b = 4.9407(10) Å, c = 13.0123(10) Å, β = 126.728(10)°) contains three different types of anions: single-atom anions of Sb3–, dumbells of Sb4–, and isolated Ga-centered tetrahedra of GaSb4
9–. The two compounds are electronically balanced, and this is confirmed by four-probe conductivity and magnetic measurements. Their very narrow band gaps, 0.014 and 0.049 eV for Na2Ba4Ga2Sb6 and Li13Ba8GaSb12, respectively, make them potential thermoelectric materials.
A novel series of sphere packings with arbitrarily low density
Authors: Dorozinski Tadeusz E. , Fischer Werner
Published: July 2006

The search for a least dense packing of spheres makes sense only under suitable restrictions because otherwise sphere packings of arbitrarily low density may be constructed. As has been shown before, the condition that all spheres have to be equal as well in their size as in their number of contacts is not such an effective restriction. A sharper condition is the demand that all spheres must have congruent patterns of contacts, i.e. that they must coincide in their first neighbourhood. The example presented here proves that also this restriction is not sufficient to avoid sphere packings with densities approaching zero.
Post-Roman History of River Systems in Western Cyprus
Authors: Deckers Kathleen
Published: July 2006

The presence of Medieval and more recent fluvial deposits in the eastern Mediterranean has important implications for archaeological field survey and for understanding settlement patterns. They may help to explain, for example, why valley floors and terraces are devoid of any sites older than a few centuries. An extensive presence of Medieval and more recent fluvial deposits has been uncovered in western Cyprus as well as in other parts of the Mediterranean. Possible causes are investigated by correlating ‘synchronous’ variables in the landscape that might have had some impact on the fluvial system. Fluvial deposits tentatively dated to the Byzantine period could be a result of the drier conditions. Some deposits, however, suggest anthropogenic influence as well. The widespread river deposition on Cyprus during the Frankish Period was probably caused by wetter conditions, which increased the frequency of overbank flooding. Moreover, increased agricultural production and mining and smelting activities might have triggered erosion and subsequent deposition in the river valleys as indicated at some localities. Fluvial deposition during the Ottoman Period may be correlated with typical ‘Little Ice Age’ climatic conditions
Acquiring authority through the acquisition of genre: Latinas, intertextuality and violence
Authors: Trinch Shonna
Published: July 2006

This article examines how laypersons acquire legal language. The site of this study is the protective order interview, where victim-survivors of domestic abuse seek legal assistance. Using thirteen protective order application interviews, in which victim-survivors had applied for orders at least once before, the analysis tests the hypothesis that women who had been through the application process would learn what constitutes relevant evidence. I borrow from theories of Second Language Acquisition that explain that when learning a foreign language, learners speak neither the target language nor their first language, but an interlanguage. Analogously, laypersons who have had iterative interaction with the legal system develop an intergenre that is neither pure story nor report. Findings are discussed as a type of 'crossing', because the intergenre raises issues of authenticity for an adversarial system that demands consistency and allows for legal decisions to turn on constructions of credibility.
The significance of the Serial Copy Management System (SCMS) in the forensic analysis of digital audio recordings
Authors: Cooper Alan J.
Published: July 2006

In a forensic authenticity examination of an audio recording, being able to prove a recording is an original or some form of copy is of paramount importance. The consumer digital audio interface defined by the IEC60958-3 standard supports the Serial Copy Management System (SCMS) protocol. The significance of SCMS in the determination of original or copied status of digital recordings produced on 'SCMS-compliant' records forms the subject of this article.
Digital audio recording analysis: the Electric Network Frequency (ENF) Criterion
Authors: Grigoras Catalin
Published: July 2006

This article reports on the Electronic Network Frequency Criterion as a means of assessing the integrity of digital audio evidence. A brief description is given of phenomena that determine ENF varaiations. In most situations,to reach a non-authenticity option, the visual inspection of spectrograms and comparison with an ENF database are enough. A more detailed investigation, in the time domaine, requires short time windows measurements and analyses. The stability of the ENF over geographical distances has been established by comparison of synchronized recordings made at different locations on the same network. A real case is presented, in which the ENF Criterios was used to investigate an audio file created with a secret surveillance system. By applying the ENF Criterion in forensic audio analysis, one can determine whether and where a digital recording has been edited, establish whether it was made at the time claimed, and identify the time and date of the registering operation.
Aural and automatic forensic speaker recognition in mismatched conditions
Authors: Alexander Anil , Dessimoz Damien , Botti Filippo , Drygajlo Andrzej
Published: July 2006

In this article, we compare aural and automatic speaker recognition in the context of forensic analyses, using a Bayesian framework for the interpretation of evidence.We use perceptual tests performed by non-experts and compare their performance with that of an automatic speaker recognition system. These experiments are performed with 90 phonetically untrained subjects. Several forensic cases were simulated, using the Polyphone IPSC-02 database, varying in linguistic content and technical conditions of recording. We estimate the strength of evidence for both humans and the baseline automatic system, calculating likelihood ratios using perceptual scores for humans and log-likelihood scores for the automatic system. A methodology analogous to the Bayesian interpretation in forensic automatic speaker recognition is applied to the perceptual scores given by humans in order to estimate the strength of evidence. The degradation of the accuracy of human recognition in mismatched recording conditions is contrasted with that of the automatic system under similar recording conditions. The conditions considered are fixed telephone, cellular telephone and noisy speech in forensically realistic conditions. The perceptual cues that the human subjects use to perceive differences in voices are studied, along with their importance in different recording conditions. We observe that while automatic speaker recognition shows higher accuracy in matched conditions of training and testing, its performance degrades significantly in mismatched conditions. Aural recognition accuracy is also observed to degrade from matched conditions to mismatched conditions and in mismatched conditions, the baseline automatic systems showed comparable or slightly degraded performance compared to the aural recognition systems. The baseline automatic system with adaptation to noisy conditions showed comparable or better performance than aural recognition. The higher level perceptual cues used by human listeners in order to recognise speakers are discussed. We also discuss the possibility of increasing the accuracy of automatic systems using the perceptual cues that remain robust to mismatched recording conditions.
Finding conversational facts: a role for linguistics in court
Authors: Siegel Muffy E.A.
Published: July 2006

Expert witnesses in semantics are controversial, since juries are the ultimate authorities on meaning. However, this article presents evidence that a semantics expert witness may be able to facilitate the accurate interpretation of linguistic evidence by helping jurors tap their own natural, intuitive judgements about what sentences in evidence would actually have meant in the context in which they were produced. Through controlled studies, I show that almost all speakers choose interpretations predicted by Grice’s conversational maxims if they are allowed to hear evidence from conversations in real conversations. In contrast, most speakers endorse a different interpretation, one predicted by logical semantic rules that coincide with their ideas of how language ought to work, when the same linguistic evidence is presented for careful examination. Instruction in linguistics reduces this difference significantly, but does not erase it. For jurors to interpret linguistic material from conversations accurately, then, they need both the relevant linguistic principles and the results of empirical studies of subjects who heard the material from the case at hand in the conversational medium in which it occurred.
Erosional effects on runout of fast landslides, debris flows and avalanches: a numerical investigation
Authors: Chen H. , Crosta G. B. , Lee C. F.
Published: July 2006

The mechanism of mass changes in debris transportation process is an important topic in the study of fast landslides, debris flows and avalanches. Basal erosion is recognised as a dynamic interaction between the original moving material and the entrained basal topsoil shearing along their non-slip contact surface. In this paper we propose a new concept of yield rate and establish the erosional relationship to bridge these two systems. A pertinent mathematical model and numerical implementation are formulated. Parametric numerical experiments are conducted to compare the erosional effects. The simulated results are consistent with available experimental and field observations. The influence of the involvement of the erosive material on runout behaviour and the global mobility of the moving material are elucidated. The proposed method is then employed to analyse a recent debris flow event in northern Italy. The excellent match to the field data gives it a plausible potential application to the analysis of this type of gravity-driven flow with significant erosion. Defined in a dimensionless form, the proposed yield rate can be estimated conveniently in general geotechnical practices.
Failure of a breakwater founded on a thick normally consolidated clay layer
Authors: Chung S. G. , Kim S. K. , Kang Y. J. , Im J. C. , Nagendra Prasad K.
Published: July 2006

Two breakwaters, 890 m and 670 m long were constructed on 55 m and 35 m thick normally consolidated clay layers in Busan, Korea. The design incorporated 12 m and 17 m deep trenches excavated in the clay and backfilled with sand. The two were similar in type and size, and their construction started simultaneously at adjacent sites. The east breakwater was successfully completed, but the west breakwater failed during the final stage of its construction. Vertical and horizontal displacements and pore pressure had been measured at a section for each breakwater throughout the construction process. Using the results obtained from the instrumentation, the behaviours of the two breakwaters are compared. The original breakwater design is re-evaluated with design parameters obtained from an additional investigation prior to the construction. It is revealed that the safety factor for arc sliding did not provide enough safety, even when the drainage effect due to consolidation was taken into account. Possible methods tracing its stability during construction are also discussed with currently available methods. A numerical analysis is performed to compare the monitored results and to evaluate the different behaviours of the breakwaters. Finally, possible causes of the failure of the breakwater are presented.