bluuebunny/crossref_metadata_2025 huggingface dataset:
IS THE JONES POLYNOMIAL OF A KNOT REALLY A POLYNOMIAL?
Authors: GAROUFALIDIS STAVROS , LÊ THANG TQ
Published: November 2006

The Jones polynomial of a knot in 3-space is a Laurent polynomial in q, with integer coefficients. Many people have pondered why this is so, and what a proper generalization of the Jones polynomial for knots in other closed 3-manifolds is. Our paper centers around this question. After reviewing several existing definitions of the Jones polynomial, we argue that the Jones polynomial is really an analytic function, in the sense of Habiro. Using this, we extend the holonomicity properties of the colored Jones function of a knot in 3-space to the case of a knot in an integer homology sphere, and we formulate an analogue of the AJ Conjecture. Our main tools are various integrality properties of topological quantum field theory invariants of links in 3-manifolds, manifested in Habiro's work on the colored Jones function.
ON COLORED QUANDLE LONGITUDES AND ITS APPLICATIONS TO TANGLE EMBEDDINGS AND VIRTUAL KNOTS
Authors: NIEBRZYDOWSKI MACIEJ
Published: November 2006

Given a long knot diagram D and a finite quandle Q, we consider the set of all quandle colorings of D with a fixed color q of its initial arc. Using this set we define the family [Formula: see text] of quandle automorphisms which is a knot invariant. For every element x ∈ Q one can consider the formal sum [Formula: see text], taken over all [Formula: see text]. Such formal sums can be applied to a tangle embedding problem and recognizing non-classical virtual knots.
A WEIBULL LIMIT LAW FOR THE FAILURE TIME OF CONSECUTIVE-k-OUT-OF-m-FROM-n:F SYSTEM
Authors: GHORAF NAMIR , KSIR BRAHIM
Published: November 2006

A "consecutive-k-out-of-m-from-n:F system" consists of n linearly or cyclically ordered components. The system fails if and only if there exist m consecutive components among them at least k ones are failed. In this paper we consider such a system with identical components and we give under some conditions a good approximation for the unreliability of the system when the number of components becomes large. More precisely, the purpose of the present paper is to show that for any failure distribution of components the limit law of the system's unreliability is always of the Weibull class. Thus we generalize here the result given in the case when the failure distribution of components is of the Weibull. We give also some numerical examples.
Increased Rho activation and PKC-mediated smooth muscle contractility in the absence of caveolin-1
Authors: Shakirova Yulia , Bonnevier Johan , Albinsson Sebastian , Adner Mikael , Rippe Bengt , Broman Jonas , Arner Anders , Swärd Karl
Published: November 2006

Caveolae are omega-shaped membrane invaginations that are abundant in smooth muscle cells. Since many receptors and signaling proteins co-localize with caveolae, these have been proposed to integrate important signaling pathways. The aim of this study was to test whether RhoA/Rho-kinase and protein kinase C (PKC)-mediated Ca2+ sensitization depends on caveolae using caveolin (Cav)-1-deficient (KO) and wild-type (WT) mice. In WT smooth muscle, caveolae were detected and Cav-1, -2 and -3 proteins were expressed. Relative mRNA expression levels were ∼15:1:1 for Cav-1, -2, and -3, respectively. Caveolae were absent in KO and reduced levels of Cav-2 and Cav-3 proteins were seen. In intact ileum longitudinal muscle, no differences in the responses to 5-HT or the muscarinic agonist carbachol were found, whereas contraction elicited by endothelin-1 was reduced. Rho activation by GTPγS was increased in KO compared with WT as shown using a pull-down assay. Following α-toxin permeabilization, no difference in Ca2+ sensitivity or in Ca2+ sensitization was detected. In KO femoral arteries, phorbol 12,13-dibutyrate (PDBu)-induced and PKC-mediated contraction was increased. This was associated with increased α1-adrenergic contraction. Following inhibition of PKC, α1-adrenergic contraction was normalized. PDBu-induced Ca2+ sensitization was not increased in permeabilized femoral arteries. In conclusion, Rho activation, but not Ca2+ sensitization, depends on caveolae in the ileum. Moreover, PKC driven arterial contraction is increased in the absence of caveolin-1. This depends on an intact plasma membrane and is not associated with altered Ca2+ sensitivity.
Database for chicken full-length cDNAs
Authors: Wang Yong , Wang Zhenggang , Li Juan , Wang Yajun , Leung Frederick C. C.
Published: November 2006

The generation of full-length cDNA databases is essential for functional genomics studies as well as for correct annotation of species genomic sequences. Human and mouse full-length cDNA projects have provided the biomedical research community with a large amount of gene information. Recent completion of the chicken genome sequence draft now enables a similar full-length cDNA project to be initiated for this species. In this report, we introduce the development of a chicken full-length cDNA database, which will facilitate future research work in this biological system. In this project, chicken expressed sequence tags (ESTs) were aligned onto human and mouse full-length cDNAs (or open reading frames) on the basis of their similarity. More than 588,000 chicken ESTs were aligned to ∼170,000 full-length human and mouse templates obtained from the NEDO, RIKEN, and MGC databases. Many of these templates have known biological functions, and their orthologous chicken genes in the EMBL database are also provided in our database, which is available at http://bioinfo.hku.hk/chicken/ . We will continue to collect known chicken full-length cDNAs to update the database for public use. The cDNA alignment results presented herein and on our database will be useful for animal science and veterinary researchers wishing to clone and to confirm full-length chicken cDNAs of interest.
Improvement of Peripheral Endothelial Dysfunction by Protein Tyrosine Phosphatase Inhibitors in Heart Failure
Authors: Vercauteren Magali , Remy Elise , Devaux Corinne , Dautreaux Brigitte , Henry Jean-Paul , Bauer Fabrice , Mulder Paul , Hooft van Huijsduijnen Rob , Bombrun Agnès , Thuillez Christian , Richard Vincent
Published: November 2006

Background—

Chronic heart failure (CHF) induces endothelial dysfunction characterized by a decrease in nitric oxide (NO) production in response to flow (flow-mediated dilatation [FMD]). Because activation of endothelial NO synthase (eNOS) by flow requires tyrosine phosphorylation, we tested whether endothelial dysfunction could be corrected by increasing phosphotyrosine levels using protein tyrosine phosphatase (PTP) inhibitors and especially inhibitors of PTP1B.

Methods and Results—

CHF was induced by coronary ligation in mice, and FMD was assessed in isolated and cannulated mesenteric artery segments (2 mm in length and <300 μm in diameter). CHF almost abolished FMD but only moderately affected the response to acetylcholine. In mice with CHF, the PTP1B inhibitors AS279, AS098, and AS713 restored FMD to levels similar to those of normal mice. This restoration was reduced by inhibitors of eNOS and phosphatidylinositol-3 kinase. Polymerase chain reaction and Western blot showed that arteries express PTP1B, and this expression was not affected by CHF. Immunolocalization revealed the presence of PTP1B in the endothelium and the adventitia. Flow induced a transient eNOS phosphorylation that was absent in CHF. PTP1B inhibition stimulated early eNOS phosphorylation and increased phosphorylation of Akt.

Conclusions—

Our results demonstrate for the first time that PTP1B inhibitors may be potent treatments for endothelial dysfunction.
Direct Evidence for a Crucial Role of the Arterial Wall in Control of Atherosclerosis Susceptibility
Authors: Pei Hong , Wang Yinong , Miyoshi Toru , Zhang Zhimin , Matsumoto Alan H. , Helm Gregory A. , Tellides George , Shi Weibin
Published: November 2006

Background—

Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) exhibit marked differences in atherosclerosis susceptibility. We sought to determine whether the difference in atherosclerosis susceptibility resides at the level of arterial walls.

Methods and Results—

Thoracic aortic segments from 8-week-old female B6 and C3H apolipoprotein E–deficient mice were transplanted into the infrarenal aorta of 10-week-old female F1 mice. After transplantation, recipients were maintained on a chow diet for 16 weeks. The donor aortic segments of B6 mice developed significantly larger atherosclerotic lesions than those of C3H (44 983±11 702 versus 5600±4885 μm
2
per section;
P
=0.011). Expression of vascular cell adhesion molecule (VCAM)-1 by endothelial cells was examined both in vitro and in vivo. B6 mice expressed significantly more VCAM-1 than their C3H counterparts. Sequence analysis of VCAM-1 cDNA revealed a nucleotide difference in the coding region that resulted in substitution of an amino acid in the protein product.

Conclusions—

These data provide direct proof that factors operating in the vessel wall, particularly endothelial cells, can serve as atherosclerosis modifiers and suggest a possibility for the contribution of VCAM-1 to atherosclerosis susceptibility.
Medical Research on Patients with Dementia – the Role of Advance Directives in European Legal Instruments
Authors: Lötjönen Salla
Published: November 2006

Current international legal instruments recognise the use of advance directives to carry on the will of the dementing research participant beyond the boundaries of her present legal capacity. Advance directives are gaining greater recognition in patient care than in medical research, where their legal status is still somewhat unclear. In particular, the three major international documents on medical research – the Council of Europe Convention on Biomedicine and Human Rights (ETS 164), its Additional Protocol on Biomedical Research (ETS 195), and Directive 2001/20/EC on Clinical Trials on Medicinal Products – give conflicting messages on the legal status of advance directives in medical research. This article examines the provisions in these documents and their national applications in Finland and the United Kingdom.
Preparation of Highly Stable Oligo(ethylene glycol) Derivatives-Functionalized Gold Nanoparticles and Their Application in LSPR-Based Detection of PSA/ACT Complex
Authors: Cao Cuong , Sim Sang Jun
Published: November 2006

A sandwich immunoassay for PSA/ACT complex detection based on gold nanoparticle aggregation using two probes was developed. The functionalized colloidal gold nanoparticles (AuNPs) showed highly stable not only in the presence of high ionic strength but also in a wide pH range. The functionalized
AuNPs were tagged with PSA/ACT complex monoclonal antibody and goat PSA polyclonal antibody and served as the probes to induce aggregation of the colloidal particles. As a result, PSA/ACT complex was detected at concentrations as low as 1 ng/ml. This is the first time that a new aggregation
sandwich-immunoassay technique using two gold probes has been used, and the results are generally applicable to other LSPR-based immunoassays.
Electron–Phonon Interaction Model and Prediction of Thermal Energy Transport in SOI Transistor
Authors: Jin Jae Sik , Lee Joon Sik
Published: November 2006

An electron–phonon interaction model is proposed and applied to thermal transport in semiconductors at micro/nanoscales. The high electron energy induced by the electric field in a transistor is transferred to the phonon system through electron–phonon interaction in the
high field region of the transistor. Due to this fact, a hot spot occurs, which is much smaller than the phonon mean free path in the Si-layer. The full phonon dispersion model based on the Boltzmann transport equation (BTE) with the relaxation time approximation is applied for the interactions
among different phonon branches and different phonon frequencies. The Joule heating by the electron–phonon scattering is modeled through the intervalley and intravalley processes for silicon by introducing average electron energy. The simulation results are compared with those obtained
by the full phonon dispersion model which treats the electron–phonon scattering as a volumetric heat source. The comparison shows that the peak temperature in the hot spot region is considerably higher and more localized than the previous results. The thermal characteristics of each
phonon mode are useful to explain the above phenomena. The optical mode phonons of negligible group velocity obtain the highest energy density from electrons, and resides in the hot spot region without any contribution to heat transport, which results in a higher temperature in that region.
Since the acoustic phonons with low group velocity show the higher energy density after electron–phonon scattering, they induce more localized heating near the hot spot region. The ballistic features are strongly observed when phonon–phonon scattering rates are lower than 4 ×
1010 s−1.
Characterization of Nanoporous Silicon Layer to Reduce the Optical Losses of Crystalline Silicon Solar Cells
Authors: Lee Soohong , Lee Eunjoo
Published: November 2006

Reduction of optical losses in crystalline silicon solar cells by surface modification is one of the most important issues of silicon photovoltaics. Porous Si layers on the front surface of textured Si substrates have been investigated with the aim of improving the optical losses of
the solar cells, because an anti-reflection coating and a surface passivation can be obtained simultaneously in one process. We have demonstrated the feasibility of a very efficient porous Si AR layer, prepared by a simple, cost effective, electrochemical etching method. Silicon p-type CZ
(100) oriented wafers were textured by anisotropic etching in sodium carbonate solution. Then, the porous Si layers were formed by electrochemical etching in HF solutions. After that, the properties of porous Si in terms of morphology, structure and reflectance are summarized. The structure
of porous Si layers was investigated using SEM. The formation of a nanoporous Si layer on the textured silicon wafer result in a reflectance lower than 5% in the wavelength region from 500 to 900 nm. Such a surface modification allows improving the Si solar cell characteristics. An efficiency
of 13.4% is achieved on a monocrystalline silicon solar cell using the electrochemical technique.
Evaluation for Protein Binding Affinity of Maghemite and Magnetite Nanoparticles
Authors: Kang Se Chan , Jo Yong Jun , Bak Jong Phil , Kim Ki-Chul , Kim Young-Sung
Published: November 2006

We investigated the protein binding affinity of magnetite (Fe3O4) and maghemite (γ-Fe2O3) nanoparticles with against non-characterized protein from human lung cancer A549 cell line on sodium dodecyl sulfate polyacrylamide gel
electrophoresis (SDS-PAGE). The binding ability of maghemite was 400 ng/mg. According to the SDS-PAGE results, the protein binding affinity of maghemite nanoparticles is stronger than magnetite nanoparticles. These data suggest that a protein can be detected with maghemite nanoparticles.
Right to sight
Authors: Starling Samantha , Willis Adrienne , Dracup Maeve , Burton Mark , Pratt Catherine
Published: November 2006

The existing uptake of eye care services by 146 learning disabled adults was investigated using a telephone questionnaire. It was found that 39 percent were receiving less eye care than the general population; those living either with families or independently were significantly less likely to have had an examination than people living with paid support staff; 30 percent of those previously examined had been diagnosed with eye problems; and 43 percent of those previously prescribed glasses were reported as unable to tolerate them. Eye examinations were offered to all participants and were found to be possible for all who attended.The implications for service provision and development are discussed.
Preparation of vermiculites for HRTEM
Authors: Marcks CH. , Wachsmuth H. , Reichenbach H. Graf V.
Published: November 2006

A technique for preparing vermiculites for examination by high-resolution transmission electron microscopy (HRTEM) has been developed. A TEM-stable expanded phase can be obtained by intercalating n-alkylammonium ions between the silicate layers of a parent biotite. The vermiculite particles were embedded in Spurr resin and centrifuged to improve orientation. Ultra-thin specimens were prepared using an ultramicrotome, the quality and thickness of the sections being monitored by TEM. Lattice images of biotite, Ba-vermiculite and octylammonium-vermiculite, the latter showing a perpendicular arrangement of the alkyl chains relative to the silicate layers, were obtained with a resolution ∼2 Å. The reliability of these images was confirmed by computer simulation.
Kaolinization of the Kimolos Island volcanics, Cyclades, Greece
Authors: Tsolis-Katagas P. , Mavronichi M.
Published: November 2006

Primary kaolins, related to Pliocene-Pleistocene volcanic rocks of acid to intermediate composition from the southern part of Kimolos island contain kaolinite and quartz ± cristobalite. Smectite is rarely present whereas alunite is common and more prevalent than baryte or gypsum. The kaolinites show structural disorder (Hinckley indices ranging from 0·6 to 1·1) and contain faults along the c*-axis. The elements Nb, Th, Ce and Sr, La, V constitute two groups with a strong intercorrelation and the kaolins are enriched in these elements compared to the parent rocks. K, Rb, Y and Ba are positively correlated with feldspar content and decrease with the intensity of kaolinization. The mineral assemblages suggest a zonal pattern which is thought to be related to different types of hydrothermal alteration. Starting from the triple point of the alunite-K-feldspar-K-mica-quartz association encountered in Kimolos, a tentative path is presented showing the approximate ranges in concentrations of K2SO4 and H2SO4 required for the formation of the various mineral assemblages.
Palaeogeographic Significance of Clay Mineral Distributions in the Inferior Oolite Group (Mid Jurassic) of Southern England
Authors: Jones L. E. , Sellwood B. W.
Published: November 2006

Five areally distinct mineral assemblages are recognized in the Inferior Oolite of S. England. In each area, vertical (stratigraphic) variations are insignificant. The five assemblages comprise varying proportions of illite, illite-smectite, kaolinite, chlorite and kaolinite-smectite, the mixed-layer clays being largely poorly crystalline and randomly interstratified. A predominantly detrital rather than authigenic origin is suggested for most of the clays. Shallow-water platform carbonates contain kaolinite with illite and illite-smectite. Kaolinite decreases in abundance away from former mid-Jurassic land areas, the deeper shelf and more basinal facies being dominated by illite and/or illite-smectite. Possible volcanic contributions to clay suites are suggested but cannot yet be fully evaluated. The palaeogeographic usefulness of clay mineral suites is confirmed, even in carbonate-dominated systems.
Vermiculite gelation: structural and textural evolution
Authors: Rausell-Colom J. A. , Saez-Auñón J. , Pons C. H.
Published: November 2006

Millimetre-sized flakes of a homogeneous, high layer charge vermiculite from S. Olalla (Spain) saturated with l'ornithine cations were made to swell in l'ornithine hydrochloride solutions of various concentrations, and the gel-like structures formed were subjected to uniaxial loads up to 150 g/cm2. Small-angle X-ray diffraction measurements from the swollen flakes show well-modulated intensity patterns from which the equilibrium interlayer distances were obtained for the various swelling conditions. The interlayer spacings can be adequately expressed as normal-logarithmic distribution functions of probability density. The gel texture is described in terms of the average number of elementary layers, all in parallel orientation, constituting independent coherent domains within the swollen flake. Changes in structure and in texture taking place as the gel volume increases, or as water is expelled from the interlayer volume under mechanical compression, are followed by the variation of the corresponding parameters of order.
Identification of thermal anomalies using clay mineral composition
Authors: Mathieu Y. , Velde B.
Published: November 2006

Analysis of the smectite content of mixed-layer illite/smectite minerals in 4 wells in the Paris Basin indicates that the sediments have not experienced the same thermal history throughout their burial history. Reconstruction of the total burial depths and thermal maxima for the sediments in the different levels of the wells indicates that the present-day depth-temperature relations reflect the existence of the same continuous sequence of diagenetic change in 2 of the wells. An empirical relation giving smectite content as a function of maximum paleotemperature was derived. A strong break in the clay mineral compositions in the upper levels of 2 wells at a third site indicated an anomaly in the diagenesis process. This break in the sequence of clay diagenetic transformation can be traced to major subvertical faults which cross-cut the wells. These anomalies are attributed to the faults which are assumed to have acted as thermal drains towards the surface, locally increasing the temperature of the sediments for a major portion of the burial history when the faults were active. Closure of the fault system coincides with the return to a normal pattern in clay diagenesis for sediments in the upper portions of the wells. It is concluded that clays may be used to trace thermal histories of sediments in a sedimentary basin.
Some crystallochemical and petrographic criteria for determining source rocks and sedimentary processes. The example of Neogene deposits of the Alpujarran Corridor (Betic Cordillera, SE Spain)
Authors: Nieto F. , Ortega-Huertas M. , Velilla N.
Published: November 2006

The aim of this study was to determine the influence of the various source areas on the Neogene sediments of the Alpujarran Corridor, to ascertain the type and intensity of the sedimentary processes involved, and to establish some generally applicable criteria. At the bottom of the sections the detrital pebbles are derived from the highest nappes of the Alpujárride Complex, whereas those at the top are from the deepest unit of the Nevado-Filábride Complex (the Veleta nappe); between these the entire range of materials from the lower-Alpujárride Complex and the upper-Navado-Filábride Unit (the Mulhacén nappe) is represented. Comparison of the micas and chlorites in the pebbles with those in the conglomerate matrix reveals the effect of the sedimentary processes on every aspect of the crystallochemistry. The d001 of the chlorites and the b0 of the micas are scarcely affected and can be used to determine the source area. The crystallinity, the Fe content of the chlorites and the basal spacing and angular difference (Δ2θ M-P) of the white micas, on the other hand, are all modified, especially in the clay fraction, according to the degree and nature of the alteration of the sediments, and consequently can be used as a guide to the extent of this process.
Short-Chain alkylammonium montmorillonites and alcohols: gas adsorption and immersional wetting
Authors: Malberg R. , Dékány I. , Lagaly G.
Published: November 2006

Short-chain alkylammonium derivatives of montmorillonite (< 8 or 10 C atoms in the alkyl chain) adsorb alcohols in the micropores between the alkylammonium ions. The external surface area and the micropore volume are derived from comparison plots of ethanol and butanol adsorption isotherms. The micropore volume varies between ∼0 (decylammonium derivative) and 100µl/g (methylammonium derivative); the external surface area determined by ethanol and butanol gas adsorption is about 50 m2/g, and is almost independent of the alkyl chain length. In contact with the alcohols, the alkylammonium ions in the interlayer space remain in h1 or h2 arrangement (monolayers or bilayers of flat-lying alkylammonium ions); on the external surface they move into an upward position. The heat of immersion decreases strongly with increasing alkyl chain length to a minimum for decylammonium ions, the variation being very similar for ethanol, butanol, hexanol, octanol and decanol. Immersion in ethanol increases the external surface area at the expense of the internal surface area. In butanol and longer alcohols this area remains unchanged. The increase of the external surface is related mainly to changes in the less ordered regions around the core of the crystals which consists of coherent silicate layers. The heat of wetting is ∼ 110 mJ/m2 (external and internal surfaces). The integral enthalpy of adsorption of butanol, 40–50 kJ/mol, is independent of the alkyl chain length (nc ≤ 8).
Routine identification of aluminium hydroxide polymorphs with the laser Raman microprobe
Authors: Rodgers K. A.
Published: November 2006

The laser Raman microprobe spectrum of gibbsite displays four intense v (OH)- stretching bands at ~3365, 3435, 3525 and 3618 cm-1, bayerite shows three near 3425, 3545 and 3564 cm-1, nordstrandite has three near 3492, 3566 and 3623 cm-1, and doyleite one broad band centred at -3545 cm-1 with sometimes a prominent shoulder near 3615 cm-1. The four polymorphs also possess distinctly different Raman signatures of medium to strong bands in the region 100–1200 cm-1. These differences provide a non-destructive routine determinative procedure by direct microsampling of untreated crystals, fragments, and microcrystalline powders. Sample preparation is minimal. Excessive noise and non-quenchable fluorescence are the principle limitations of the technique.
Pillaring of synthetic hectorite by mixed [Al13-xFex] Pillars
Authors: Bergaya F. , Hassoun N. , Barrault J. , Gatineau L.
Published: November 2006

The pillaring of a Laponite by alumina pillars, iron pillars and mixed Al-Fe pillars was obtained by a simple in situ method starting from AlCl3 and/or FeCl3 solutions with different molar ratio Fe/(Fe + Al), and from NaOH solution added simultaneously to the clay suspension. The Al13 pillars were evidenced by XRD and NMR spectra. The density and the charge of these pillars were calculated from the chemical analysis. The Fe pillars (in samples with Fe content >26%) are larger than Al13 pillars and slowly reducible by hydrogen temperature programmed reduction (H2TPR), but we do not have any information on their structure. There is also an excess of non-pillar Fe retained by the pillared clays probably as oxyhydroxides. The isomorphic substitution in the mixed (Al-Fe)13 pillars (in samples with an Fe content >26%) was evidenced by H2TPR results compared to the chemical analyses and by the interpretation of the 27A1 peaks in the NMR spectra.
Pretreatment of Fithian illite for oxygen isotope analysis
Authors: Hogg A. J. C. , Pearson M. J. , Fallick A. E.
Published: November 2006

Oxygen isotope analysis of clay minerals presents several practical difficulties. These include their very fine grain size, the presence of both hydroxyl and non-hydroxyl oxygen, adsorbed water and, where clays from oil reservoirs are concerned, the possibility of hydrocarbon contamination. To develop routines which would minimize these problems while leaving the isotope systematics of the clay undisturbed, a series of oxygen isotope analyses were made under different running conditions of the API Standard Illite–the Fithian illite.
Influence of Geological Material in the Composition of Surface Waters of Galicia (Nw Spain). Genesis of Clay Minerals
Authors: Calvo De Anta R. , Macias F.
Published: November 2006

The composition of fluvial waters can be used to predict the processes of formation and evolution of secondary minerals in Galician soils. These processes are similar in areas with different rocks, from acid to basic, the only exception being strongly serpentinized materials. In general, the nature of the rock has less influence than the characteristics of the alteration system, which is always open, acid and freely draining. Mineral neoformation is always of the monosialitic type, having different degrees of evolution. The incipient phases tend to form gibbsite as a more stable mineral, and halloysite, allophanes and imogolite as metastable forms. With time, a crystalline kaolinite would be the only stable species. These results agree with the mineralogy and the andic or ferralic properties of the soils.
Interstrat-An Expert System to Help Identify Interstratified Clay Minerals from Powder XRD Data: I. Description of the Program
Authors: Garvie L. A. J.
Published: November 2006

The INTERSTRAT program has been specifically designed to aid the geologist in the identification of the phyllosilicates from powder XRD data. The program achieves this by comparing the experimental00ld-spacings with a knowledge base of diffraction parameters; a set of likely solutions is then displayed. The method employed by INTERSTRAT is analogous to that used by the clay mineralogist whereby the clays are initially identified down to the group level from the d(OOl) data alone. This procedure also utilises thed-spacings collected from clays that have been subjected to standard clay mineral treatments, i.e. glycolation and heating to 300~ and 500~ One of the most important features of INTERSTRAT is its knowledge base of d-spacings for the interstratified clay minerals in which calculatedd(00l)spacings for an individual mixed-layer clay are recorded with respect to its Reichweite, the state under which the d-spacings were collected and the percentage of the mixed-layer components.
Size and Thickness Measurement of Polydisperse Clay Samples
Authors: Jennings B. R.
Published: November 2006

Measurement of clay particle size invariably presents data in the form of equivalent spherical diameters. For asymmetric particles the equivalent spherical diameter varies with the method of measurement. Based upon an understanding of the theoretical concepts involved, a method has been proposed whereby comparison of data on a given sample from two different techniques can reveal information about the minor dimension of the particle. Theoretical expressions are given for the equivalent spherical diameter of cylindrically symmetric rods and discs from which it is shown that some of the existing measurement methods are more dependent upon size than the degree of non-sphericity whilst for others the reverse is true. It is shown how for rods and discs one can obtain information on both an average axial ratio and the distribution of this parameter for heterogeneous samples. Illustrated data are given for three kaolin samples. Far from showing inconsistency between the variable spherical diameters yielded by different instruments, the data produce compatible size and thickness parameters which match those observed in supplementary, unreported electron microscope experiments. A method of measuring particle major and minor parameter distributions is indicated.
Textural and Isotopic Variations in Diagenetic Kaolinite from the Magnus Oilfield Sandstones
Authors: Macaulay C. I. , Fallick A. E. , Haszeldine R. S.
Published: November 2006

In Upper Jurassic sandstones of the Magnus Sandstone Member from the Magnus Oilfield in the North Sea, diagenetic kaolinite morphology and isotopic composition vary away from the Late Cimmerian unconformity. Near the unconformity, coarse-grained (15-30 μm) vermiform kaolinite morphology is most common, whereas downdip, 3 km away, fine-grained (∼10 μm) blocky morphology is prevalent. Kaolinite abundances increase downdip, away from the unconformity, and kaolinite near the unconformity has low δ18O (12·5-14·9%o smow) compared to that downdip (15·9−17·5%o). This reflects replacement of marine depositional pore-waters by meteoric water near the erosion surface. However, isotopic temperature estimates suggest that the majority of kaolinite formed at elevated burial temperatures of ~80°C, and not during subaerial exposure of the sandstone. The δD of kaolinite close to the unconformity is also lower than that downdip. Kaolinite morphology and isotopic composition record meteoric water ingress during Late Cimmerian subaerial erosion and retention of meteoric-derived water in the crest of the Magnus structure during burial diagenesis. Kaolinite formation during subaerial exposure is not of significance to the sandstone reservoir quality.
Deletion of the V2 vasopressin receptor gene in two Chinese patients with nephrogenic diabetes insipidus
Authors: Dong Yan , Sheng Haihui , Chen Xueru , Yin Jun , Su Qing
Published: November 2006

Background

Congenital nephrogenic diabetes insipidus (NDI) is a rare X-linked inherited disorder characterized by the excretion of large volumes of diluted urine and caused by mutations in arginine vasopressin receptor 2 (AVPR2) gene. To investigate the mutation of AVPR2 gene in a Chinese family with congenital NDI, we screened AVPR2 gene in two NDI patients and eight family members by PCR amplification and direct sequencing.

Results

Five specific fragments, covering entire coding sequence and their flanking intronic sequences of AVPR2 gene, were not observed in both patients, while those fragments were all detected in the control subjects. Several different fragments around the AVPR2 locus were amplified step by step. It was revealed that a genomic fragment of 5,995-bp, which contained the entire AVPR2 gene and the last exon (exon 22) of the C1 gene, was deleted and a 3-bp (GAG) was inserted. Examination of the other family members showed that the mothers and the grandmother were carriers for this deletion.

Conclusion

Our findings suggest that the two patients in a Chinese family suffering from congenital NDI had a 5,995-bp deletion and 3-bp (GAG) insertion at Xq28. The deletion contained the entire AVPR2 gene and exon 22 of the C1 gene.
Molecular patterns of sex determination in the animal kingdom: a comparative study of the biology of reproduction
Authors: Manolakou Panagiota , Lavranos Giagkos , Angelopoulou Roxani
Published: November 2006

Determining sexual fate is an integral part of reproduction, used as a means to enrich the genome. A variety of such regulatory mechanisms have been described so far and some of the more extensively studied ones are being discussed.

For the insect order of Hymenoptera, the choice lies between uniparental haploid males and biparental diploid females, originating from unfertilized and fertilized eggs accordingly. This mechanism is also known as single-locus complementary sex determination (slCSD). On the other hand, for Dipterans and Drosophila melanogaster, sex is determined by the ratio of X chromosomes to autosomes and the sex switching gene, sxl. Another model organism whose sex depends on the X:A ratio, Caenorhabditis elegans, has furthermore to provide for the brief period of spermatogenesis in hermaphrodites (XX) without the benefit of the "male" genes of the sex determination pathway.

Many reptiles have no discernible sex determining genes. Their sexual fate is determined by the temperature of the environment during the thermosensitive period (TSP) of incubation, which regulates aromatase activity. Variable patterns of sex determination apply in fish and amphibians. In birds, while sex chromosomes do exist, females are the heterogametic (ZW) and males the homogametic sex (ZZ). However, we have yet to decipher which of the two (Z or W) is responsible for the choice between males and females.

In mammals, sex determination is based on the presence of two identical (XX) or distinct (XY) gonosomes. This is believed to be the result of a lengthy evolutionary process, emerging from a common ancestral autosomal pair. Indeed, X and Y present different levels of homology in various mammals, supporting the argument of a gradual structural differentiation starting around the SRY region. The latter initiates a gene cascade that results in the formation of a male. Regulation of sex steroid production is also a major result of these genetic interactions. Similar observations have been described not only in mammals, but also in other vertebrates, emphasizing the need for further study of both normal hormonal regulators of sexual phenotype and patterns of epigenetic/environmental disruption.
DADOS-Prospective: an open source application for Web-based prospective data collection
Authors: Nguyen Lam , Shah Anand , Harker Matthew , Martins Henrique , McCready Mariana , Menezes Andreia , Jacobs Danny O , Pietrobon Ricardo
Published: November 2006

Background

Randomized, prospective trials involving multi-institutional collaboration have become a central part of clinical and translational research. However, data management and coordination of multi-center studies is a complex process that involves developing systems for data collection and quality control, tracking data queries and resolutions, as well as developing communication procedures. We describe DADOS-Prospective, an open-source Web-based application for collecting and managing prospective data on human subjects for clinical and translational trials. DADOS-Prospective not only permits users to create new clinical research forms (CRF) and supports electronic signatures, but also offers the advantage of containing, in a single environment, raw research data in downloadable spreadsheet format, source documentation and regulatory files stored in PDF format, and audit trails.

Results

Feedback from formal and field usability tests was used to guide the design and development of DADOS-Prospective. To date, DADOS-Prospective has been implemented in five prospective clinical studies at our institution. Four of these studies are still in the CRF creation phase and one study has been entirely launched.

Conclusion

DADOS-Prospective has significant advantages over existing Web-based data collecting programs. At our institution, it has been demonstrated to be an efficient tool for prospective clinical studies.
MLN51and GM-CSF involvement in the proliferation of fibroblast-like synoviocytes in the pathogenesis of rheumatoid arthritis
Authors: Jang Jinah , Lim Dae-Seog , Choi Young-Eun , Jeong Yong , Yoo Seung-Ah , Kim Wan-Uk , Bae Yong-Soo
Published: November 2006

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease of unclear etiology. This study was conducted to identify critical factors involved in the synovial hyperplasia in RA pathology. We applied cDNA microarray analysis to profile the gene expressions of RA fibroblast-like synoviocytes (FLSs) from patients with RA. We found that the MLN51 (metastatic lymph node 51) gene, identified in breast cancer, is remarkably upregulated in the hyperactive RA FLSs. However, growth-retarded RA FLSs passaged in vitro expressed small quantities of MLN51. MLN51 expression was significantly enhanced in the FLSs when the growth-retarded FLSs were treated with granulocyte – macrophage colony-stimulating factor (GM-CSF) or synovial fluid (SF). Anti-GM-CSF neutralizing antibody blocked the MLN51 expression even though the FLSs were cultured in the presence of SF. In contrast, GM-CSF in SFs existed at a significant level in the patients with RA (n = 6), in comparison with the other inflammatory cytokines, IL-1β and TNF-α. Most RA FLSs at passage 10 or more recovered from their growth retardation when cultured in the presence of SF. The SF-mediated growth recovery was markedly impaired by anti-GM-CSF antibody. Growth-retarded RA FLSs recovered their proliferative capacity after treatment with GM-CSF in a dose-dependent manner. However, MLN51 knock-down by siRNA completely blocked the GM-CSF/SF-mediated proliferation of RA FLSs. Taken together, our results imply that MLN51, induced by GM-CSF, is important in the proliferation of RA FLSs in the pathogenesis of RA.
Estimation of layer thickness and velocity changes using 4D prestack seismic data
Authors: Røste Thomas , Stovas Alexey , Landrø Martin
Published: November 2006

In some hydrocarbon reservoirs, severe compaction of the reservoir rocks is observed. This compaction is caused by production and is often associated with stretching and arching of the overburden rocks. Time-lapse seismic data can be used to monitor these processes. Since compaction and stretching cause changes in layer thickness as well as seismic velocities, it is crucial to develop methods to distinguish between the two effects.

We introduce a new method based on detailed analysis of time-lapse prestack seismic data. The equations are derived assuming that the entire model consists of only one single layer with no vertical velocity variations. The method incorporates lateral variations in (relative) velocity changes by utilizing zero-offset and offset-dependent time shifts. To test the method, we design a 2D synthetic model that undergoes severe reservoir compaction as well as stretching of the overburden rocks. Finally, we utilize the method to analyze a real 2D prestack time-lapse seismic line from the Valhall field, acquired in 1992 and 2002. For a horizon at a depth of around [Formula: see text], which is near the top reservoir horizon, a subsidence of [Formula: see text] and a velocity decrease of [Formula: see text] for the sequence from the sea surface to the top reservoir horizon are estimated. By assuming that the base of the reservoir remains constant in depth, a reservoir compaction of 3.6% (corresponding to a subsidence of the top reservoir horizon of [Formula: see text]) and a corresponding reservoir velocity increase of 6.7% (corresponding to a velocity increase of [Formula: see text]) are estimated.
Low-frequency seismic properties of thermally cracked and argon-saturated granite
Authors: Lu Cao , Jackson Ian
Published: November 2006

Torsional forced-oscillation techniques have been used to measure the shear modulus and strain-energy dissipation on cylindrical specimens of a fine-grained granite, Delegate aplite. The specimens were subjected to thermal cycling and associated microcracking under varying conditions of confining pressure [Formula: see text] and argon pore-fluid pressure [Formula: see text] within the low-frequency saturated isobaric regime. Complementary transient-flow studies of in-situ permeability and volumetric measurements of connected crack porosity allowed the modulus measurements to be interpreted in terms of the density and interconnectivity of the thermally generated cracks. The modulus measurements indicate that newly generated thermal cracks are closed by a differential pressure, [Formula: see text], which ranges from [Formula: see text] for temperatures of [Formula: see text]. This suggests crack aspect ratios on the order of [Formula: see text]. The covariation of in-situ permeability [Formula: see text] and thermal crack density [Formula: see text] that we infer from the modulus deficit is consistent with percolation theory. There is a well-defined threshold at [Formula: see text], beyond which [Formula: see text] increases markedly as [Formula: see text], with [Formula: see text]. At lower crack densities, it is difficult to measure the sensitivity of shear modulus to variations of confining and pore pressures because pore-pressure equilibrium is approached so sluggishly. At temperatures beyond the percolation threshold, the modulus variation is a function of the effective pressure, [Formula: see text], with the value of [Formula: see text] increasing toward one with increasing crack connectivity.
Exploration for unconformity-type uranium deposits with audiomagnetotelluric data: A case study from the McArthur River mine, Saskatchewan, Canada
Authors: Tuncer Volkan , Unsworth Martyn J. , Siripunvaraporn Weerachai , Craven James A.
Published: November 2006

Unconformity-type deposits supply a significant amount of the world’s uranium and consist of uranium that is generally codeposited with graphite in a fault zone. The low resistivity of the graphite produces a significant contrast in electrical resistivity, which can be located with electromagnetic (EM) methods. The Athabasca Basin in Western Canada hosts significant uranium deposits, and exploration in deeper parts of the basin has required the application of new EM methods. This paper presents an evaluation of the audiomagnetotelluric (AMT) exploration method at the McArthur River mine in the Athabasca Basin. AMT data were collected at 132 stations on a grid, and two-dimensional (2D) and three-dimensional (3D) inversions were used to generate resistivity models. These models showed two major results: (1) a significant conductor coincident with a major basement fault (P2) and the uranium deposits (this conductor begins at the unconformity at a depth of [Formula: see text] and extends to a depth of at least three km) and (2) a resistive halo which might be caused by the silicification associated with mineralization. However, synthetic inversions showed that this halo could be an artifact of smoothing function in the inversion scheme. The 2D inversions were validated by synthetic inversions, comparison with the 3D inversion models, and correlation with well-log information. 3D AMT forward modeling showed that strong 3D effects are not present in the AMT impedance data. Induction vectors showed more evidence of complexity, but the inclusion of these data in the inversion improved subsurface resolution.
Catecholamine‐Secreting Metastatic Carcinoid as Differential Diagnosis in Pheochromocytoma
Authors: WHITMAN HENDRICKS H. , FISHMAN ELLIOT K. , ÖBERG KJELL , WILDMAN JOSEPH M. , LONG ANDREA L.
Published: November 2006

Abstract:  Catecholamine‐secreting metastatic carcinoid should be considered in differential diagnosis of malignant pheochromocytoma. Paroxysmal functioning or hormonally silent gastroenteropancreatic neuroendocrine tumors (GEP NETs) require repeat biochemical measurements and sensitive anatomic and functional imaging studies overlapping those for malignant pheochromocytoma. This report presents clinical, laboratory, and radiologic findings in a patient presenting with heart rate variability; vasoactive headaches reactive to ethanol, tyramine and tryptophan; labile blood pressure; diaphoresis; diarrhea; abdominal pain; unexplained pancreatitis; joint pain; and paroxysmal flushing with pallor. GI studies (including endoscopic ultrasound) and multiple imaging modalities (including 2D CT, MRI with gadolinium, [18]FDG PET/CT, [123I]MIBG, and SRS [111In]Octreotide [OctreoScan]) were not diagnostic. 24‐h BP, Holter and 30‐day cardiac event monitors plus urinary biochemical studies consistently suggested catecholamine‐synthesizing NET. NIH plasma metanephrines studies and [6]‐[18F]Fluorodopamine PET ruled out malignant pheochromocytoma (pheo). Repeated studies showed persistently abnormal GEP NET biomarkers and urinary catecholamines. Capsule endoscopy revealed suspicious submucosal lesions throughout the small intestine. Dual‐phase 64‐slice multidetector computed tomography (MDCT) with 3D volumetric reconstruction of the abdomen and pelvis revealed multiple diffuse liver metastases and three extrahepatic lesions consistent with metastatic carcinoid. In combination, intensive biochemical testing repeated over time, dual‐phase 64‐slice MDCT with 3D image reconstruction and volume‐rendering (VR) technique, and advanced radionuclide imaging are required to detect NETs' sporadic or paroxysmal functioning, rule out extra‐adrenal pheochromocytoma, and localize and characterize metastatic carcinoid. If pheochromocytoma is ruled out, yet symptoms and biochemical markers for catecholamine excess are present, then carcinoid and other amine‐precursor‐uptake decarboxylation (APUD) tumors must remain in the differential diagnosis.