bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of the X chromosome in mammalian extra embryonic development
Authors: Hemberger M.
Published: August 2003

Accumulating evidence points to the importance of the X chromosome for trophoblast development. In rodents, the extraembryonic cell lineage differs from somatic tissues in that X chromosome inactivation is imprinted, preferentially silencing the paternal X chromosome. As a consequence, trophoblast development is extremely susceptible to deviations from normal X inactivation and is impaired in situations of increased and reduced X-linked gene dosage. Mouse mutants have also shown that maintenance of X chromosome silencing in extraembryonic tissues requires a special set of heterochro- matin proteins. Moreover, the X chromosome has been implicated in causing several malformations of the placenta. The observed importance of the X chromosome for placental development can be explained by the presence of many trophoblast-expressed genes, especially in the proximal and central regions. Given that the placenta represents a postzygotic barrier to reproduction, evolutionary constraints may be responsible for the presence of placental genes on the X chromosome that are often co-expressed in brain and testis.
The role of Zic3 in vertebrate development
Authors: Herman G.E. , El-Hodiri H.M.
Published: August 2003

Zic3 is a C2H2 zinc finger transcription factor that is involved in early patterning of the vertebrate embryo. Human patients with mutations in the X-linked ZIC3 gene have a complex developmental phenotype that includes laterality defects, congenital heart disease, and lumbosacral and anal anomalies, including neural tube defects. Similar phenotypes are found in the bent tail (Bn) mouse, a spontaneous mutation that is associated with a submicroscopic deletion of the Zic3 locus, as well as in a Zic3 null allele generated through homologous recombination. These findings suggest that Zic3 plays important roles during development in establishing a proper left-right axis and in midline neural patterning. This review will summarize our current understanding of the role of Zic3 in patterning of the vertebrate embryo, based on studies in model organisms such as Xenopus and the mouse. In addition, a comparison of Zic3 with other vertebrate Zic family members will be provided.
X chromosomes of American marsupials contain minimal amounts of euchromatin
Authors: Schmid M. , Feichtinger W. , Steinlein C. , Haaf T. , Visbal García R. , Fernández Badillo A.
Published: August 2003

The karyotypes of four South American didelphid marsupials, representing diploid numbers of 2n = 14 and 18, have been analyzed by a variety of banding techniques. The 2n = 14 karyotypes display a high degree of homoeology, but there also exist distinct similarities between the 2n = 14 and 2n = 18 karyotypes. The interspecific differences found are due to centric fissions, pericentric inversions, and variations in the amount and composition of the constitutive heterochromatin. Contrary to the evolutionary conservation of the banding patterns in all autosomal arms, there are multiple differences in the number and chromosomal location of the nucleolus organ- izer regions. In species with X-linked nucleolus organizers, the 18S + 28S ribosomal RNA genes escape inactivation in female cells. Measurements on the X chromosomes of Marmosa fuscata and Micoureus demerarae unexpectedly reveal the lowest quantities of euchromatin so far determined in the X chromosomes of mammals: 1.5% and 1.8%, respectively, of their haploid female genomes. This is significantly less than the amount of euchromatin in the basic X chromosomes of other marsupials (3%) or eutherians (5%).
Choosing Haplotype-Tagging SNPS Based on Unphased Genotype Data Using a Preliminary Sample of Unrelated Subjects with an Example from the Multiethnic Cohort Study
Authors: Stram Daniel O. , Haiman Christopher A. , Hirschhorn Joel N. , Altshuler David , Kolonel Laurence N. , Henderson Brian E. , Pike Malcolm C.
Published: August 2003

We describe an approach for picking haplotype-tagging single nucleotide polymorphisms (htSNPs) that is presently being taken in two large nested case-control studies within a multiethnic cohort (MEC), which are engaged in a search for associations between risk of prostate and breast cancer and common genetic variations in candidate genes. Based on a preliminary sample of 70 control subjects chosen at random from each of the 5 ethnic groups in the MEC we estimate haplotype frequencies using a variant of the Excoffier-Slatkin E-M algorithm after genotyping a high density of SNPs selected every 3–5 kb in and surrounding a candidate gene. In order to evaluate the performance of a candidate set of htSNPS (which will be genotyped in the much larger case-control sample) we treat the haplotype frequencies estimate above as known, and carry out a formal calculation of the uncertainty of the number of copies of common haplotypes carried by an individual, summarizing this calculation as a coefficient of determination, R2h. A candidate set of htSNPS of a given size is chosen so as to maximize the minimum value of R2h over the common haplotypes, h.
Cardiovascular Protective Effects of Synthetic Isoflavone Derivatives in Apolipoprotein E-Deficient Mice
Authors: Jiang Fan , Jones Gregory T. , Husband Alan J. , Dusting Gregory J.
Published: August 2003

Dietary flavonoids are thought to protect against cardiovascular disease. We have studied the effects of bioactive isoflavone metabolites on hyperlipidemia, endothelial dysfunction and the development of atherosclerotic lesions in apolipoprotein E-deficient (apoE⁰) mice fed a Western high-fat diet. Supplementation with dihydrodaidzein (DiD), dehydroequol (DeE) (both 25 mg kg–1· day–1) and their combination (D/D; 12.5 mg kg–1·day–1 for each) for 24 weeks reduced plasma high-density lipoprotein (HDL) and non-HDL cholesterol. D/D also reduced the triglyceride level. In the abdominal aorta of apoE⁰ mice, these compounds significantly increased endothelial nitric oxide (NO)-mediated vasorelaxations induced by acetylcholine, but had a minor effect on relaxations induced by the NO donor S-nitroso-N-acetylpenicillamine. Isoflavone treatment for 24 weeks had no effect on the total area of atherosclerotic plaques in the whole aorta, but DeE reduced the plaque thickness in the aortic arch by 29%, although this did not reach statistical significance. The endothelial dysfunction in apoE⁰ mice is associated with hyperlipidemia and increased vascular oxidative stress measured as increased superoxide production. Both isoflavones have superoxide-scavenging activities in vitro. We suggest that chronic supplementation with bioactive isoflavone metabolites may protect endothelial NO function in apoE⁰ mice, through both lipid-lowering and antioxidant actions.
Integrins: Sensors of Extracellular Matrix and Modulators of Cell Function
Authors: Pozzi Ambra , Zent Roy
Published: August 2003

Integrins are a large family of transmembrane receptors for extracellular matrix (ECM) molecules. They play a critical role in organ morphogenesis, physiology and pathology, as they can modulate and control different cell functions, including adhesion, shape, polarity, growth, differentiation and motility. Integrins interact with ECM components via their extracellular domains, while their cytoplasmic domains play a pivotal role in mediating integrin-dependent cellular functions. The integrin cytoplasmic tails interact with the cytoskeleton, signaling molecules and other cellular proteins, resulting in regulation of many biological functions. In this review, we will mainly describe the role of integrins in regulating cell motility and discuss some new paradigms in integrin biology that may impact upon nephrology with respect to renal development and renal functions during both physiological and pathological events.
Podocyte Changes after Induction of Acute Albuminuria in Mice by Anti-Aminopeptidase A mAb
Authors: Dijkman Henry B.P.M. , Gerlofs-Nijland Miriam E. , van der Laak Jeroen A.W.M. , Wetzels Jack F.M. , Groenen Patricia J.T.A. , Assmann Karel J.M.
Published: August 2003

Administration of a specific combination of anti-aminopeptidase A (APA) mAb (ASD-37/41) in mice induces an acute albuminuria which is independent of angiotensin II, a well-known substrate of APA. In the present experiments, we examined whether binding of the mAb initiated changes in the podocytic expression of cytoskeleton (-associated), adhesion and slit-diaphragm proteins in relation to the time course of albuminuria. In addition, we measured ultrastructurally the extent of foot process retraction (the number of foot processes per µm GBM) and the width of the slit pore between the podocytes by morphometric methods. An injection of the mAb combination ASD-37/41 induced a massive but transient albuminuria that started at 6 h, and peaked at 8 h, after which it declined. However, even at day 7 after injection of the mAbs some albuminuria was present. Injection of the combination ASD-3/41 or saline did not induce an albuminuria. Notably, we observed changes in the staining of CD2AP and podocin, two slit-pore-associated proteins that coincided with the start of the albuminuria. Nephrin staining was reduced and podocytic actin staining became more granular only at a time albuminuria was declining (24 h). The number of foot processes per µm GBM was already decreased at 4 h with a further reduction thereafter. The width of the slit pore was unchanged at the time of peak albuminuria and gradually decreased thereafter. At day 7, podocytic foot process effacement was even more prominent although albuminuria was only slightly abnormal. Expression of CD2AP was still granular. We observed however a change toward normal in the expression of podocin. Injection of saline or ASD-3/41 had no effect on the expression of podocytic proteins, the number of foot processes or width of the slit pore. Our data show that the onset of albuminuria in the anti-APA model is related to alterations in CD2AP and podocin, proteins that are important for maintaining slit-diaphragm structure and podocytic function. Extended studies at day 7 demonstrated uncoupling of albuminuria, podocytic foot process effacement and CD2AP staining. Changes in podocin more closely paralleled changes in albuminuria.
Co-Registration of Function and Anatomy in Frameless Stereotaxy by Contour Fitting
Authors: Kober Helmut , Nimsky Christopher , Vieth Jürgen , Fahlbusch Rudolf , Ganslandt Oliver
Published: August 2003

We investigated a co-registration algorithm using a contour-fitting procedure to integrate functional data from magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) for frameless stereotaxy. In fMRI the shape of the head was reconstructed from anatomical images, in MEG it was scanned using an electromagnetic sensor position indicator. Functional information was transferred to the 3D-MR image set used for frameless stereotaxy by fitting the digitized (MEG) and reconstructed head shape (fMRI) to the 3D-MR images. The mean residual error of the contour fit was 2.3 mm for the MEG and 1.3 mm for the fMRI registration. According to computer simulations, the achievable transformation error is 0.75 and 0.5 mm, respectively. This method enables independent recording of functional and anatomical measurements with a co-registration accuracy better than 2 mm.
Effect of Chronic Heart Rate Reduction with Ivabradine on Carotid and Aortic Structure and Function in Normotensive and Hypertensive Rats
Authors: Albaladejo P. , Carusi A. , Apartian A. , Lacolley P. , Safar M.E. , Bénétos A.
Published: August 2003

Background: A reduction of heart rate (HR) by surgical means or pharmacological agents affects the progression and/or regression of atherosclerotic lesions. Nevertheless, the effect of bradycardia per se on large artery structure and function has never been investigated in rat models of hypertension. Methods: Four groups of Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) were treated for 28 days either by placebo or by the selective HR-reducing agent ivabradine (8.4 mg/kg/day), a novel compound devoid of inotropic or vasodilating effects and without direct action on the autonomic nervous system. At the end of the follow-up period, intra-arterial blood pressure, carotid pulsatile arterial hemodynamics (echo tracking techniques) and the medial cross-sectional area (MCSA) of the aorta and the carotid artery were determined. Results: In conscious animals, chronic administration of ivabradine significantly reduced HR by 26–30% with no change in tail systolic blood pressure. In anesthetized animals, the decrease in HR and the subsequent increase in the diastolic period were responsible for a decrease in diastolic blood pressure. At the site of the large arteries, ivabradine produced a decrease in the MCSA of the thoracic but not of the abdominal aorta, as well as an increase in pulsatile change of the carotid diameter without change in the isobaric distensibility and MCSA. The changes in pulsatile diameter were significantly larger in WKY rats than in SHRs. Conclusion: In normotensive and mainly in SHRs, selective chronic HR reduction by ivabradine is associated with alterations in large arteries involving an aortic antihypertrophic effect.
In vitro Study of Starling’s Hypothesis in a Cultured Monolayer of Bovine Aortic Endothelial Cells
Authors: Pang Zhengyu , Tarbell John M.
Published: August 2003

Starling’s hypothesis that fluid movement across the microvascular wall is determined by the transmural differences in hydrostatic and osmotic pressures was tested using an in vitro model comprised of bovine aortic endothelial cells grown on a porous support. In all experiments, a 1% bovine serum albumin (BSA) solution was maintained in the abluminal reservoir and the luminal reservoir contained either a 1 or a 5.5% BSA solution. The global osmotic pressure difference across the endothelial layers was thus either 0 or 20.3 cm H2O. When the luminal concentration of BSA was changed from 1 to 5.5% at a hydrostatic pressure differential of 5, 10 or 20 cm H2O, no reverse flow (in the reabsorption direction) was observed even though the hydrostatic pressure differential was far below the global osmotic pressure differential. In another case, the hydrostatic pressure differential was dropped quickly from 20 to 5 cm H2O, while a constant osmotic pressure differential was maintained by 5.5% BSA in the luminal reservoir. A strong transient reabsorption flow was observed over a 30-second period which diminished to undetectable levels within 2.5 min; then a sustained steady-state filtration flow was observed after 20 min. These in vitro experiments support other studies in capillaries showing transient reabsorption that decays to steady-state filtration at longer times.
Induction of Angiogenesis in Omentum with Vascular Endothelial Growth Factor: Influence on the Viability of Encapsulated Rat Pancreatic Islets during Transplantation
Authors: Sigrist S. , Mechine-Neuville A. , Mandes K. , Calenda V. , Legeay G. , Bellocq J.-P. , Pinget M. , Kessler L.
Published: August 2003

Transplantation of pancreatic islets is proposed as a treatment for type 1 diabetes, but insufficient blood supply can cause the loss of viable grafted islets. In the present study, we investigated the influence of vascular endothelial growth factor (VEGF) on the angiogenesis of omentum during encapsulated islet allotransplantation and consequently on islet survival. Fifty rat islets, cultured for 24 h, were encapsulated in the presence or absence of human VEGF and implanted in the peritoneal cavity of rats (n = 6). After 7, 14 and 28 days of implantation, encapsulation devices with surrounding omentum were removed. Histological analysis of this tissue was performed. Cellular adhesion at the membrane surface was characterized by a phagocytosis test. The morphological aspect of the islets was analyzed and their functionality was evaluated by measuring insulin secretion. At each step of the study, there was a two-fold increase in the number of vessels in the presence of VEGF. In addition, VEGF increased the vessel diameter and the surface area of the angiogenic pedicle. Moreover, the presence of VEGF significantly decreased the distance between the devices and vessels (16.2 ± 5.6 vs. 51.6 ± 10.1 µm, p < 0.001). Membrane surface analysis showed a decrease in macrophage adhesion in the presence of VEGF. Furthermore, islet structure and functionality was preserved in the presence of VEGF. Stimulation of angiogenesis of omentum induced by VEGF is associated with preservation of islet viability. Local delivery of VEGF proved to be a relevant approach to ameliorate the outcome of islet transplantation.
Intravenous Nitroglycerin in the Management of Retained Placenta
Authors: Chedraui Peter A. , Insuasti Daniel F.
Published: August 2003

Thirty patients in the third stage of delivery complicated by retained placenta were prospectively managed with intravenous nitroglycerin. We studied the effect of nitroglycerin on the hemodynamics and characteristics of the procedure, and also analyzed labor and maternal and neonatal data. Intravenous nitroglycerin effectively aided the extraction of the retained placenta in all cases. The average procedure time was 5.3 ± 1.1 min, and the dose range was 50–200 µg. Systolic and diastolic blood pressure fell significantly from 111 ± 7.5 to 103 ± 6 mm Hg and from 74 ± 6.7 to 67 ± 6.6 mm Hg, respectively (p < 0.05). Although statistically significant, this was not evident clinically and there were no complications. Intravenous nitroglycerin at a dose of 200 µg or less is safe, effective and predictable in the management of retained placenta and could obviate the need of general anesthesia.
Preoperative Assessment of Myometrial Invasion and Cervical Involvement of Endometrial Cancer by Transvaginal Ultrasonography
Authors: Köse Gültekin , Aka Nurettin , Api Murat
Published: August 2003

The aim of the study was to assess the depth of myometrial invasion and cervical involvement by endometrial cancer using preoperative 6.5-MHz, high-frequency transvaginal ultrasonography as compared with postoperative assessment using histopathological examination. The study included 47 patients with histologically proven cancers of the endometrium. All patients underwent transvaginal sonography before surgery. The depth of myometrial invasion was classified as none, inner half of the uterine wall, and outer half of the uterine wall. Cervical spread is recorded as positive or negative. Of 36 (76.6%) patients with proven myometrial invasion, 33 cases (91.66%) were revealed by sonography. Histologically proven cervical invasion that correlated with sonography was shown in 3 patients (75%). In 7 patients (14.9%) ultrasonography could not correctly predict the depth of myometrial invasion. The depth of invasion was underestimated in 4 (8.5%) cases and overestimated in 3 (6.4%) cases. Preoperative assessment of invasion of the uterine wall and cervical spread by transvaginal ultrasonography had an accuracy of 85 and 97.8% if correlated with the definitive histopathological examination. The role of transvaginal ultrasonography in preoperative assessment of the depth of myometrial invasion and cervical involvement in patients with endometrial cancer needs to be studied further before making reliable conclusions.
The chemokine SDF1/CXCL12 and its receptor CXCR4 regulate mouse germ cell migration and survival
Authors: Molyneaux Kathleen A. , Zinszner Hélène , Kunwar Prabhat S. , Schaible Kyle , Stebler Jürg , Sunshine Mary Jean , O'Brien William , Raz Erez , Littman Dan , Wylie Chris , Lehmann Ruth
Published: August 2003

In mouse embryos, germ cells arise during gastrulation and migrate to the early gonad. First, they emerge from the primitive streak into the region of the endoderm that forms the hindgut. Later in development, a second phase of migration takes place in which they migrate out of the gut to the genital ridges. There, they co-assemble with somatic cells to form the gonad. In vitro studies in the mouse, and genetic studies in other organisms, suggest that at least part of this process is in response to secreted signals from other tissues. Recent genetic evidence in zebrafish has shown that the interaction between stromal cell-derived factor 1 (SDF1) and its G-protein-coupled receptor CXCR4, already known to control many types of normal and pathological cell migrations, is also required for the normal migration of primordial germ cells. We show that in the mouse, germ cell migration and survival requires the SDF1/CXCR4 interaction. First, migrating germ cells express CXCR4, whilst the body wall mesenchyme and genital ridges express the ligand SDF1. Second,the addition of exogenous SDF1 to living embryo cultures causes aberrant germ cell migration from the gut. Third, germ cells in embryos carrying targeted mutations in CXCR4 do not colonize the gonad normally. However, at earlier stages in the hindgut, germ cells are unaffected in CXCR4-/-embryos. Germ cell counts at different stages suggest that SDF1/CXCR4 interaction also mediates germ cell survival. These results show that the SDF1/CXCR4 interaction is specifically required for the colonization of the gonads by primordial germ cells, but not for earlier stages in germ cell migration. This demonstrates a high degree of evolutionary conservation of part of the mechanism, but also an area of evolutionary divergence.
A functional overlap of plasminogen and MMPs regulates vascularization during placental development
Authors: Solberg Helene , Rinkenberger Julie , Danø Keld , Werb Zena , Lund Leif R.
Published: August 2003

Both plasminogen activators and matrix metalloproteinases (MMPs) have been implicated in a variety of developmental processes in the mouse during embryo implantation and placentation. We show here that pharmacological treatment of plasminogen-deficient mice with the broad spectrum MMP inhibitor galardin leads to a high rate of embryonic lethality. Implantation sites from plasminogen-deficient galardin-treated mice at 7.5 days post coitus (dpc)showed delay in both decidualization and invasion of maternal vessels into the decidua. At 8.5 dpc, half of the embryos were runted and still at the developmental stage of a 7.5 dpc embryo. Most embryos that escaped these initial defects eventually died, probably from defective vascularization and development of the labyrinth layer of the placenta, although a direct role on embryo development cannot be ruled out. These results demonstrate that the combination of MMPs and plasminogen is essential for the proper development of the placenta. Plasminogen deficiency alone and galardin treatment alone had much less effect and there was a pronounced synergism on both placental vascularization and embryonic lethality, indicating a functional overlap between plasminogen and MMPs.
Interaction of Par-6 and Crumbs complexes is essential for photoreceptor morphogenesis inDrosophila
Authors: Nam Sang-Chul , Choi Kwang-Wook
Published: August 2003

Apicobasal cell polarity is crucial for morphogenesis of photoreceptor rhabdomeres and adherens junctions (AJs) in the Drosophila eye. Crumbs (Crb) is specifically localized to the apical membrane of photoreceptors, providing a positional cue for the organization of rhabdomeres and AJs. We show that the Crb complex consisting of Crb, Stardust (Sdt) and Discs-lost (Dlt) colocalizes with another protein complex containing Par-6 and atypical protein kinase C (aPKC) in the rhabdomere stalk of photoreceptors. Loss of each component of the Crb complex causes age-dependent mislocalization of Par-6 complex proteins, and ectopic expression of Crb intracellular domain is sufficient to recruit the Par-6 complex. We also show that the absence of Par-6 complex proteins results in severe mislocalization and loss of Crb complex. We further demonstrate that Dlt directly binds to Par-6, providing a molecular basis for the mutual dependence of the two complexes. These results suggest that the interaction of Crb and Par-6 complexes is required for the organization and maintenance of apical membranes and AJs of photoreceptors.
Quantification of central metabolic fluxes in the facultative methylotroph methylobacterium extorquens AM1 using 13C‐label tracing and mass spectrometry
Authors: Van Dien Stephen J. , Strovas Tim , Lidstrom Mary E.
Published: August 2003

The metabolic fluxes of central carbon metabolism were measured in chemostat‐grown cultures of Methylobacterium extorquens AM1 with methanol as the sole organic carbon and energy source and growth‐limiting substrate. Label tracing experiments were carried out using 70% 13C‐methanol in the feed, and the steady‐state mass isotopomer distributions of amino acids derived from total cell protein were measured by gas chromatography coupled to mass spectrometry. Fluxes were calculated from the isotopomer distribution data using an isotopomer balance model and evolutionary error minimization algorithm. The combination of labeled methanol with unlabeled CO2, which enters central metabolism in two different reactions, provided the discriminatory power necessary to allow quantification of the unknown fluxes within a reasonably small confidence interval. In wild‐type M. extorquens AM1, no measurable flux was detected through pyruvate dehydrogenase or malic enzyme, and very little flux through α‐ketoglutarate dehydrogenase (1.4% of total carbon). In contrast, the α‐ketoglutarate dehydrogenase flux was 25.5% of total carbon in the regulatory mutant strain phaR, while the pyruvate dehydrogenase and malic enzyme fluxes remained insignificant. The success of this technique with growth on C1 compounds suggests that it can be applied to help characterize the effects of other regulatory mutations, and serve as a diagnostic tool in the metabolic engineering of methylotrophic bacteria. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 45–55, 2003.
Environmental compensation in planning: a review of five different countries with major emphasis on the German system
Authors: Rundcrantz Kristina , Skärbäck Erik
Published: August 2003

The use of different measures to compensate the environment when human development projects take place has been frequently discussed in both Europe and the USA. This paper reviews the use of environmental compensation in Germany, the USA, the Netherlands, the UK and Sweden. In Germany compensation methods have been used since the 1970s. In the USA there are requirements for mitigation and compensation measures for wetland losses. In the Netherlands, the compensation measures are focused on certain protected areas. In the UK there are few legal instruments that formally require environmental compensation. In Sweden the new environmental legislation has made it possible to legally demand environmental compensation measures to gain permits for exploitations. However, these new Swedish requirements have only been available since 1999 and the use of compensation measures needs to be developed. In this article we argue that the German environmental compensation practice is most developed and is worth further study in order to develop the use of environmental compensation methods in the Swedish planning system. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Top‐down and data‐based mechanistic modelling of rainfall–flow dynamics at the catchment scale
Authors: Young Peter
Published: August 2003

The data‐based mechanistic (DBM) approach to modelling has developed as a stochastic, ‘top‐down’ response to the problems associated with the deterministic, ‘bottom‐up’ approach. As such, it can be compared with the deterministic, top‐down modelling methods that have been attracting attention recently in the hydrological literature. Using catchment‐scale rainfall–flow modelling as an example, this paper compares the inductive DBM approach with its hypothetico‐deductive, deterministic alternative and shows how they can be used to identify and estimate low‐order, nonlinear models of the rainfall–flow dynamics in the River Hodder catchment of northwest England based on a limited set of rainfall–flow data. Copyright © 2003 John Wiley & Sons, Ltd.
Data‐supported robust parameterisations in land surface–atmosphere flux predictions: towards a top‐down approach
Authors: Schulz Karsten , Beven Keith
Published: August 2003

The current tendency in ‘physically based’ soil–vegetation–atmosphere transfer (SVAT) schemes is to use increasingly complex process descriptions to predict evaporative fluxes at both patch and landscape scales. This approach does not take proper account of the heterogeneities that are evident in any landscape. A top‐down approach to sub‐grid‐scale land surface parameterization would suggest that the current complexity may not be supported by the calibration data available. By comparing three SVAT schemes of differing complexity within the generalized likelihood uncertainty estimation framework, we demonstrate the utility of simpler rather than more complex models when calibrated against flux data from various intensive field campaigns. A more robust calibration is achieved for a simple evaporative fraction approach allowing the feasible parameter ranges to be more strongly conditioned by the available data. It is argued that a top‐down (dominant mode) predictive model based on a database of such robustly estimated parameter values would result in no greater uncertainty at the scales of application than trying to form parameter sets for complex models from a variety of sources. Copyright © 2003 John Wiley & Sons, Ltd.
17O NMR data of phenoxyethyl derivatives
Authors: Jios Jorge L. , Duddeck Helmut , Romanelli Gustavo P. , Autino Juan Carlos
Published: August 2003

17O NMR data for 52 phenoxyethyl derivation have been measured and assigned. Copyright © 2003 John Wiley & Sons, Ltd.
NOESY, HOESY, T1 and solid‐state NMR studies on [RuH(η6‐toluene)(Binap)](CF3SO3): a molecule with a strongly distorted piano‐stool structure
Authors: Geldbach Tilmann J. , Rüegger Heinz , Pregosin Paul S.
Published: August 2003

Detailed solution‐NMR studies on the distorted ruthenium hydride complex [RuH(η6‐toluene)(Binap)](CF3SO3) (2) are reported. NOE‐spectroscopy, together with low‐temperature 1H and 31P NMR data, reveals restricted rotation around a P—C bond for a specific axial P—phenyl ring with the activation energy determined via simulation. From 19F, 1H HOESY data, the approach of the triflate anion relative to the hydride ligand is established. Comparison of the quadrupole coupling constant CQF from both solution‐ and solid‐state MAS‐NMR on the deuteride [RuD(η6‐benzene)(Binap)](CF3SO3) (1‐D) provide information on the nature of the Ru—H bond. Copyright © 2003 John Wiley & Sons, Ltd.
Non‐degradative dissolution and acetylation of ball‐milled plant cell walls: high‐resolution solution‐state NMR
Authors: Lu Fachuang , Ralph John
Published: August 2003

Two solvent systems for fully dissolving, and optionally derivatizing, finely ground plant cell wall material at room temperature are described: dimethylsulfoxide (DMSO) and tetrabutylammonium fluoride (TBAF) or N‐methylimidazole (NMI). In situ acetylation produces acetylated cell walls (Ac‐CWs) that are fully soluble in chloroform. Lignin structures tested remain fully intact. The dispersion of 13C–1H correlations afforded by two‐dimensional (2D) nuclear magnetic resonance (NMR) experiments reveals the major lignin units, allowing the whole lignin fraction to be analyzed by high‐resolution solution‐state NMR methods for the first time. Non‐degradative cell wall dissolution offers the potential to analyze polysaccharide components, and improve current cell wall analytical methods by using standard homogeneous solution‐state chemistry.
The plant cyclin‐dependent kinase inhibitor ICK1 has distinct functional domains for in vivo kinase inhibition, protein instability and nuclear localization
Authors: Zhou Yongming , Li Genyi , Brandizzi Federica , Fowke Larry C. , Wang Hong
Published: August 2003

Interactor/inhibitor 1 of Cdc2 kinase (ICK1) from Arabidopsis thaliana is the first plant cyclin‐dependent kinase (CDK) inhibitor, and overexpression of ICK1 inhibits CDK activity, cell division and plant growth in transgenic plants. In this study, ICK1 and deletion mutants were expressed either alone or as green fluorescent protein (GFP) fusion proteins in transgenic Arabidopsis plants. Deletion of the C‐terminal 15 or 29 amino acids greatly reduced or completely abolished the effects of ICK1 on the transgenic plants, and recombinant proteins lacking the C‐terminal residues lost the ability to bind to CDK complex and the kinase inhibition activity, demonstrating the role of the conserved C‐terminal domain in in vivo kinase inhibition. In contrast, the mutant ICK1ΔN108 with the N‐terminal 108 residues deleted had much stronger effects on plants than the full‐length ICK1. Analyses demonstrated that this effect was not because of an enhanced ability of ICK1ΔN108 protein to inhibit CDK activity, but a result of a much higher level of ICK1ΔN108 protein in the plants, indicating that the N‐terminal domain contains a sequence or element increasing protein instability in vivo. Furthermore, GFP‐ICK1 protein was restricted to the nuclei in roots of transgenic plants, even with the C‐terminal or the N‐terminal domain deleted, suggesting that a sequence in the central domain of ICK1 is responsible for nuclear localization. These results provide mechanistic understanding about the function and regulation of this cell cycle regulator in plants.
Growth in sulfidic mineral environments: metal resistance mechanisms in acidophilic micro-organisms
Authors: Dopson Mark , Baker-Austin Craig , Koppineedi P. Ram , Bond Philip L.
Published: August 2003

Acidophilic micro-organisms inhabit some of the most metal-rich environments known, including both natural and man-made ecosystems, and as such are ideal model systems for study of microbial metal resistance. Although metal resistance systems have been studied in neutrophilic micro-organisms, it is only in recent years that attention has been placed on metal resistance in acidophiles. The five metal resistance mechanisms identified in neutrophiles are also present in acidophiles, in some cases utilizing homologous proteins, but in many cases the degree of resistance is greater in acidophiles. This review summarizes the knowledge of acidophile metal resistance and presents preliminary in silico studies on a few known metal resistance systems in the sequenced acidophile genomes.
Effect of EDTA on Salmonella enterica serovar Typhimurium involves a component not assignable to lipopolysaccharide release
Authors: Alakomi H.-L. , Saarela M. , Helander I. M.
Published: August 2003

The effect of EDTA on Salmonella enterica serovar Typhimurium was studied in different growth phases with cells grown with or without Ca2+ and Mg2+ supplementation. EDTA affected the outer membrane much more strongly in the early exponential phase than in the mid- or late exponential phase, as indicated by uptake of 1-N-phenylnaphthylamine (a nonpolar hydrophobic probe, M
r 219), and detergent (SDS) susceptibility. This effect was, however, not paralleled by LPS release (determined by measuring LPS-specific fatty acids or 14C-labelled LPS in cell-free supernatants, per a standardized cell density), which remained unchanged as a function of the growth curve. The conclusion from these results is that in the early exponential phase the effect of EDTA in S. enterica involves a component that is independent of LPS release.
The influence of satisfaction, trust and switching barriers on customer retention in a continuous purchasing setting
Authors: Ranaweera Chatura , Prabhu Jaideep
Published: August 2003

Adopts a holistic approach that examines the combined effects of satisfaction, trust and switching barriers on customer retention in a continuous purchasing setting. Argues that such an approach helps uncover hitherto neglected effects on retention and, in the process, unveils more cost effective ways of retaining customers. Drawing on this framework develops several hypotheses regarding the main and interaction effects of customer satisfaction, trust and switching barriers on retention. Tests these hypotheses on data from a large‐scale mail survey of fixed line telephone users in the UK, finding that both customer satisfaction and trust have strong positive effects on customer retention. Contrary to some assertions in the literature, however, finds that the effect of trust on retention is weaker than that of satisfaction. Nevertheless, the interaction between trust and satisfaction also has a significant effect on retention, indicating that building both customer satisfaction and trust is a superior strategy to a focus on satisfaction alone. Qualitative evidence from the survey offers further support for this finding. Even a “satisfying” service recovery process might be inadequate to prevent loss of trust, with significant implications for future consumer behaviour. Finally, the results show that switching barriers have both a significant positive effect on customer retention as well as a moderating effect on the relationship between satisfaction and retention. While service providers may be able to retain even dissatisfied customers who perceive high switching barriers, argues that ideally, firms should aim at a combined strategy that makes switching barriers act as a complement to satisfaction.
State‐based management
Authors: Rossiter Margaret
Published: August 2003

State‐based management (SBM) is a specific form of the game‐play methodology (GPM) – an approach to the application of constraints in humanity activity systems. The theory that supports GPM was developed using a team sports model and promotes a coordination of workers’ efforts, without limiting their individual abilities to be creative in support of corporate goals. This paper reports on research undertaken to prove the applicability of GPM to a business environment. The case studies focused on over‐the‐counter (OTC) banking services. The use of game‐play tactics (SBM) in the banking chamber was highly successful. It provided a mechanism for designing constraints that addressed issues of the incomplete and inaccurate system state knowledge usually held by the tellers. Further, the process promoted the development of a team ethos, and this change in attitudes had positive repercussions on the overall working environment
Comovements in UK regional property markets: a multivariate cointegration analysis
Authors: Worthington Andrew C. , Higgs Helen
Published: August 2003

This paper examines the short and long‐term comovements among UK regional property markets over the period 1976‐2001. The markets examined are London, Outer South East, East Anglia, South West, East Midlands, West Midlands, Yorkshire and Humberside, North and North West. Multivariate cointegration procedures, Granger non‐causality tests, level VAR and generalised variance decomposition analyses based on error‐correction and vector autoregressive models are conducted to analyse relationships among these markets. The results indicate that there is a stationary, long‐term relationship and a number of long‐term causal linkages between the various UK property markets. In terms of the percentage of variance explained, other regional markets are generally more important than innovations in a given region, though this is not the case for the Outer South East. The Outer South East market is segmented from the other regional markets, though also extremely influential in explaining forecast variance in these markets. The overall suggestion is that opportunities exist for portfolio diversification in the UK regional property market, and the Outer South East market should be seen as containing valuable information for forecasting performance in the regional markets.
Real estate appraisal: a review of valuation methods
Authors: Pagourtzi Elli , Assimakopoulos Vassilis , Hatzichristos Thomas , French Nick
Published: August 2003

The valuation of real estate is a central tenet for all businesses. Land and property are factors of production and, as with any other asset, the value of the land flows from the use to which it is put, and that in turn is dependent upon the demand (and supply) for the product that is produced. Valuation, in its simplest form, is the determination of the amount for which the property will transact on a particular date. However, there is a wide range of purposes for which valuations are required. These range from valuations for purchase and sale, transfer, tax assessment, expropriation, inheritance or estate settlement, investment and financing. The objective of the paper is to provide a brief overview of the methods used in real estate valuation. Valuation methods can be grouped as traditional and advanced. The traditional methods are regression models, comparable, cost, income, profit and contractor’s method. The advanced methods are ANNs, hedonic pricing method, spatial analysis methods, fuzzy logic and ARIMA models.
Labor‐Environmental Relations: An Analysis of the Relationship between Labor Unions and Environmentalists
Authors: Obach Brian K.
Published: August 2003

Objective. I seek to assess the quality of relations between labor unions and environmental organizations and to identify economic, political, and organizational factors that influence those relations. Methods. A survey of state labor leaders was conducted in order to determine the quality of relations between unions and environmental organizations around the United States. Ordinary least squares regression is used to identify associations between state level economic and political indicators and the quality of labor‐environmental relations. Results. Relations between labor unions and environmentalists are generally positive. Except for the timber industry, there is no evidence of hostility between environmentalists and unions in industries that may be threatened with job loss due to environmental measures. Republican control of state government and labor‐industry cooperation are associated with poor labor‐environmental relations. Conclusions. Popular beliefs about entrenched “jobs versus the environment” conflict are largely unfounded. Instances of conflict between unions and environmental advocates are rare and largely isolated in certain employment sectors. Although unions and environmentalists share certain interests, Republican political control reduces cooperation between these two constituencies. Unions can be seen as situated between employers and environmentalists in regard to environmental issues. Cooperation with employers results in poorer relations between unions and environmentalists.
Few and Far Between? An Environmental Equity Analysis of the Geographic Distribution of Hazardous Waste Generation
Authors: Atlas Mark
Published: August 2003

Objective. This article examines whether the generation of hazardous waste is concentrated in communities that are disproportionately minority or low income. Whereas much environmental equity research has focused on commercial facilities managing hazardous waste, facilities that generate and manage their own wastes—which account for over 98 percent of hazardous waste volume—have been ignored. Methods. The demographic characteristics were determined of people in geographic concentric rings around hazardous waste generators accounting for most of the country's 1997 hazardous waste volume. Results. My analyses indicate no tendency for disproportionately minority communities to be near these facilities. In fact, relatively few people are near where most hazardous waste is generated. Although a few of these facilities have large numbers of minority people around them, most are in areas with higher than average white populations. There was, however, a tendency for low‐income communities to be near these facilities. Conclusions. To the extent that there are potential risks from the presence of hazardous waste at facilities, most of this risk is in relatively unpopulated areas. The presence of hazardous waste is not concentrated in areas that are disproportionately minority or low income.
“In My Opinion . . .”: Justices’ Opinion Writing in the U.S. Supreme Court, 1946–1997
Authors: Brenner Saul , Heberlig Eric S.
Published: August 2003

Objectives. We develop hypotheses to explain the opinion writing by justices on the U.S. Supreme Court from 1946–1997. Methods. We use data from the U.S. Supreme Court Database, Phases I and II, to examine the proportion of cases in which a justice writes an opinion each term as well as the differences between writing majority, dissenting, and concurring opinions. OLS regression with robust standard errors is the estimation procedure. Results. We find that a justice's position as Chief Justice, professional and education background, reputation ranking, and tenure on the Court can explain a justice's opinion writing. At the same time, we discover that particular variables have different affects on writing majority, dissenting, or concurring opinions. Conclusions. This study demonstrates the importance of both structural and personal background variables in explaining judicial behavior. It also shows the importance of analyzing different kinds of judicial opinions when explaining the justices’ opinion writing.
Race, Gender, and Educational Advantage in the Inner City
Authors: LaVeist Thomas A. , McDonald Katrina Bell
Published: August 2003

Objective. In this study we examine race differences in the effect of childhood in an urban inner–city community on educational attainment in adulthood. Methods. We examine a cohort of African American and white individuals born in the late 1950s and early 1960s in the same hospital. Our analysis examines a set of individual, family, and community characteristics for the respondents at three time points in their life course, birth, childhood, and adulthood. Results. We find that black men and women are substantially more likely than their white counterparts to graduate from high school, and that black women are more likely than white men, black men, and white women to graduate from high school and college. Conclusions. We conclude that social policy to eradicate urban disadvantage must not shift its focus to the plight of poor whites to the neglect of African Americans. Rather, we urge that inner–city white children be “drawn out of the shadows” of social research and that the uniqueness of race, class, and gender intersections realized in the inner city be brought to bear.
Epidemiological Survey of
Babesia
Species in Japan Performed with Specimens from Ticks Collected from Dogs and Detection of New
Babesia
DNA Closely Related to
Babesia odocoilei
and
Babesia divergens
DNA
Authors: Inokuma Hisashi , Yoshizaki Yukako , Shimada Yojiro , Sakata Yoshimi , Okuda Masaru , Onishi Takafumi
Published: August 2003

Detection and analysis of
Babesia
species from ticks recovered from dogs in Japan were attempted by PCR and nucleotide sequence analysis based on the 18S rRNA gene, respectively. A total of 1,136 ticks were examined for
Babesia
DNA by 18S rRNA-based PCR and nucleotide sequencing. Partial sequences of
Babesia canis vogeli
DNA were detected from six ticks in Aomori, Nara, Hiroshima, Oita, and Okinawa Prefectures; and
Babesia gibsoni
Asia-1 DNA was also detected in four ticks in Osaka, Hiroshima, Miyazaki, and Okinawa Prefectures. Unique sequences of 1,678 bp were also obtained from
Ixodes ovatus
ticks in Akita and Fukui Prefectures. The sequences were similar to those of
Babesia odocoilei
(97.7%) and
Babesia divergens
(97.6%). This is the first report of the detection of DNA belonging to this group in Japan.
Single-Nucleotide-Polymorphism Mapping of the
Pseudomonas aeruginosa
Type III Secretion Toxins for Development of a Diagnostic Multiplex PCR System
Authors: Ajayi Temitayo , Allmond Leonard R. , Sawa Teiji , Wiener-Kronish Jeanine P.
Published: August 2003

We mapped the coding single nucleotide polymorphisms in four toxin genes—
exoS
,
exoT
,
exoU
, and
exoY
—of the
Pseudomonas aeruginosa
type III secretion system among several clinical isolates. We then used this information to design a multiplex PCR assay based on the simultaneous amplification of fragments of these genes. Eight strains of known genotype were used to test our multiplex PCR method, which showed 100% sensitivity and specificity in this small sample size. This assay appears to be promising for the rapid and accurate genotyping of the presence of these genes in clinical strains of
P. aeruginosa
.