bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mouse Model for Influenza
Authors: Matsuoka Yumiko , Lamirande Elaine W. , Subbarao Kanta
Published: May 2009

A major challenge in influenza research is the selection of an appropriate animal model that accurately reflects the disease and protective immune response to influenza infection in humans. Ferrets are exquisitely susceptible to infection with human influenza viruses and are widely believed to be the ideal small animal model for influenza research. Mice have also been used for influenza vaccine research for decades. Although human influenza viruses generally cause disease in mice only if they are first adapted to the species, the ready availability of mice, their relatively low cost, and the variety of genetic backgrounds and targeted defects, and the immunologic reagents available make the mouse an attractive and heavily utilized animal model for studies of influenza. Although they are not discussed in detail in this unit, hamsters, guinea pigs, cotton rats (Sigmodon), and rats (Rattus) have also been used for influenza research. Curr. Protoc. Microbiol. 13:15G.3.1‐15G.3.30. © 2009 by John Wiley & Sons, Inc.
Effects of mixing on electrical properties of carbon nanofiber and polymer composites
Authors: Lee Sungho , Jeon Young‐Pyo
Published: May 2009

We examined electrical properties of composites of carbon nanofibers (CNFs)/linear low‐density polyethylene (LLDPE) in the range of mixing time. An addition of CNFs into LLDPE led to a decrease of electrical resistivity, and the large amounts of CNFs were required to reach the electrical percolation threshold for the longer mixing time. For the research of these phenomena, we examined the effects of mixing time on the size (length) and spatial distributions of CNFs in the composites. SEM micrographs revealed the size reduction of CNFs in a series of mixing times, although the spatial dispersion of CNFs became more uniform at longer mixing time. To describe the reduction of CNFs theoretically, we hypothesize the size distribution of CNFs obeys a governing population balance kinetics based on an irreversible dissolution process. For the process, we proposed a size dependent breakage rate coefficient proportional to the size of CNFs. The model prediction for the time evolution of size distribution of CNFs has been validated with the experimental measurement showing good agreement. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
On the asymptotic non‐null distributions of the LR criterion in a general manova
Authors: Fujikoshi Yasunori
Published: May 2009

In this paper we give a unified derivation of asymptotic expansions of the non‐null distributions of the likelihood ratio (= LR) criterion in a general MANOVA, when the matrix Ω of noncentrality parameters is 0(1) and Ω = 0(N), respectively, where N means the sample size. The asymptotic formulas are obtained by expanding the characteristic function expressed in terms of the hypergeometric function 2F2 of matrix argument.
Low‐temperature operation of thin film solid oxide fuel cells prepared by RF magnetron sputtering
Authors: Nagata Akiyoshi , Nishimoto Akifumi
Published: May 2009

Thin film solid oxygen fuel cells (SOFC) with yttria‐stabilized zirconia (YSZ) electrolyte films 3 to 12 μm thick, grown by RF magnetron sputtering on porous Ni‐YSZ cermet substrates for use as fuel electrodes, were studied to determine their power generation properties at lower operating temperatures in the vicinity of 700 °C. Single SOFCs with a YSZ electrolyte film thickness of 3 μm could be effectively operated at 800 °C and had a V–I performance measure of 700 mV–300 mA/cm2. The open circuit voltage (OCV) of the cells was nearly the same as the theoretical value. However, the OCV drop became larger as the thickness of the YSZ film was decreased, because grain boundaries and pores occurred in the film due to the surface roughness of the substrate. The voltage drop of the cells was due mainly to resistance loss in the YSZ film, and the dominance of this factor increased as the operating temperature decreased. The film conductivity at an operating temperature of 800 °C was two orders of magnitude smaller than the theoretical conductivity of the bulk electrolyte. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(6): 50–57, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10047
A ferroelectric electron emitter having a vacuum gap
Authors: Ohwada Iwao , Sugiyama Tomohiko , Nanataki Tsutomu
Published: May 2009

A novel electron emitter utilizing the characteristics of ferroelectric ceramic materials has been developed. The electron‐emitting portion of the electron emitter has a unique micro‐structure which has the vacuum gap between an upper electrode and the surface of a ferroelectric layer. We confirmed electron emission by a three‐step process which consists of electron charge (the first step), charge retention (the second step), and electron emission (the third step). The ferroelectric hysteresis in the process indicates unique characteristics as follows. At the first step, remnant polarization of the same level as the completely adhered electrode structure is obtained in spite of a vacuum gap because the electron charge develops from the upper electrode to the surface of the ferroelectric layer under the vacuum gap in synchronism with the polarization reversal of the ferroelectric layer. On the other hand, at the third step, the electric field in the vacuum gap advances electron emission while the development of the polarization reversal inhibits the return of the electron charge along the surface of the ferroelectric layer. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(6): 21–30, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10083
A combined molecular modeling study on gelatinases and their potent inhibitors
Authors: Xi Lili , Du Juan , Li Shuyan , Li Jiazhong , Liu Huanxiang , Yao Xiaojun
Published: May 2009

Zinc‐dependent matrix metalloproteinase (MMP) family is considered to be an attractive target because of its important role in many physiological and pathological processes. In the present work, a molecular modeling study combining protein‐, ligand‐ and complex‐based computational methods was performed to analyze a new series of β‐N‐biaryl ether sulfonamide hydroxamates as potent inhibitors of gelatinase A (MMP‐2) and gelatinase B (MMP‐9). Firstly, the similarities and differences between the binding sites of MMP‐2 and MMP‐9 were analyzed through sequence alignment and structural superimposition. Secondly, in order to extract structural features influencing the activities of these inhibitors, quantitative structure‐activity relationship (QSAR) models using genetic algorithm‐multiple linear regression (GA‐MLR), comparative molecular field (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were developed. The proposed QSAR models could give good predictive ability for the studied inhibitors. Thirdly, docking study was employed to further explore the binding mode between the ligand and protein. The results from all the above analyses could provide the information about the similarities and differences of the binding mode between the MMP‐2, MMP‐9 and their potent inhibitors. The obtained results can provide very useful information for the design of new potential inhibitors. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010
Emotional competence and work performance: The mediating effect of proactivity and the moderating effect of job autonomy
Authors: Kim Tae‐Yeol , Cable Daniel M. , Kim Sang‐Pyo , Wang Jie
Published: May 2009

This paper proposes and tests a model where emotional competence influences work performance through employees' proactive behaviors toward their supervisors. Results from 196 supervisor‐employee pairs supported that emotional competence was positively associated with proactive behaviors, and proactive behaviors were positively associated with both task effectiveness and social integration. In addition, proactive behaviors significantly mediated the relationships between emotional competence and work performance, although this was mostly true of followers who had a higher degree of autonomy in their work. Copyright © 2009 John Wiley & Sons, Ltd.
Conifer pollen abundance provides a proxy for summer temperature: evidence from the latitudinal forest limit in Finland
Authors: Huusko Antti , Hicks Sheila
Published: May 2009

A 23‐year record of pollen deposition (pollen accumulation rates: PARs) indicates that pollen production of the two most common northern boreal conifers – pine and spruce – varies dramatically from year to year and that high and low pollen years show consistency over the whole of northern Lapland. Testing for a calibration between the annual PARs of these two trees and a whole range of meteorological parameters reveals that the highest correlation is between pollen quantity and summer temperature centred around July of the year before pollen emission. Critical mean July temperature limits for the flowering of Pinus and Picea are 12°C and 13°C, respectively. This strong and region‐wide relationship suggests that fossil Pinus and Picea PARs could be used as a proxy for summer temperature. Results are illustrated as maps showing the relationship between forest limits and July temperature and between PARs and the correlation coefficient with July temperature. It is noticeable, however, that although the climate signal is strong at the forest limit of the taxon in question, it is often weaker in the centre of its ecological range. This has implications when interpreting fossil pollen records. Temperature calibrations will vary spatially as the position of the forest limit changes. Copyright © 2009 John Wiley & Sons, Ltd.
Rapid response of parkinsonian tremor to STN‐DBS changes: Direct modulation of oscillatory basal ganglia activity?
Authors: Blahak Christian , Bäzner Hansjörg , Capelle Hans‐Holger , Wöhrle Johannes C. , Weigel Ralf , Hennerici Michael G. , Krauss Joachim K.
Published: May 2009

Although deep brain stimulation (DBS) of the subthalamic nucleus (STN) has proved to be effective for tremor and other cardinal symptoms in Parkinson's disease (PD), the precise mechanisms of action of DBS are still unclear. We analyzed the time course of resting tremor amplitude and frequency during discontinuation and subsequent reinitiation of STN‐DBS in nine PD patients, using a computerized three‐dimensional motion analysis combined with surface electromyography. Following discontinuation of STN‐DBS, resting tremor amplitude rapidly increased, reaching maximum amplitude after 2 min (mean ± 95%CI: 34.3 ± 13.8 mm; P < 0.01), subsequently stabilizing at a medium level. Reinitiation of stimulation after 30 min resulted in rapid, nearly complete suppression of tremor activity within 1 min (1.4 ± 1.3 mm; P < 0.01) and, furthermore, increased tremor frequency within a few seconds in seven of nine patients. These findings support the hypothesis that STN‐DBS acts by direct interference with the neurotransmission of basal ganglia networks involved in tremor. © 2009 Movement Disorder Society
Adapting the Sniffin' Sticks to diagnose Parkinson's disease in Sri Lanka
Authors: Silveira‐Moriyama Laura , Sirisena Dharshana , Gamage Pasan , Gamage Ranjanie , de Silva Rohan , Lees Andrew J.
Published: May 2009

Tests of odor identification might help differentiate Parkinson's disease (PD) from other causes of tremor, but they are culture and language specific and are not currently available for the population of Sri Lanka. We created a Sinhala adaptation of the 16‐item identification test from Sniffin' Sticks (SS‐16) and applied it to 89 nondemented Sri Lankan PD patients and 100 controls. Twelve of the SS‐16 items were correctly identified by at least 50% of the control subjects and were included in a battery, which we called as Colombo SS‐12. We used the diagnosis (PD or control) as outcome variable for a logistic regression using age, gender, smoking status and the SS‐12 as covariates, and found only the last two were significant covariates. The Colombo SS‐12 specificity was 93.0% with a sensitivity of 91.0%, indicating it could be a helpful tool in the diagnosis of PD in Sri Lanka. © 2009 Movement Disorder Society
Dysfunction of the subthalamic nucleus induces behavioral and movement disorders in monkeys
Authors: Karachi Carine , Grabli David , Baup Nicolas , Mounayar Stéphanie , Tandé Dominique , François Chantal , Hirsch Etienne C.
Published: May 2009

High‐frequency stimulation of the subthalamic nucleus (STN) in parkinsonian patients is reported to induce psychiatric effects. The likely explanation for these effects is the partitioning of the STN into sensorimotor, associative, and limbic anatomo‐functional territories. Thus, a specific neuronal dysfunction of the STN sensorimotor territory could lead to abnormal movements, whereas a dysfunction of the associative or limbic territory could lead to behavioral disturbances. To test this hypothesis, neuronal dysfunction of the STN was induced by microinjections of the GABA agonist muscimol, or antagonist bicucculline, in various parts of the nucleus in three monkeys. Stereotyped behaviors (licking and biting fingers) and/or violent hyperactivity were obtained with bicuculline injected into the anteromedial, associative, and limbic territories, whereas injections of muscimol induced no major effects. Abnormal limb movements (contralateral ballism) were obtained after muscimol or bicuculline injections into the posterolateral, sensorimotor territory. Control injections localized around the STN induced other effects (mainly torticollis), which underlines the specificity of STN injection effects. Our study supports the hypothesis that the anteromedial part of the STN is involved in behavioral control. © 2009 Movement Disorder Society
The syndromal validity and nosological position of apathy in Parkinson's disease
Authors: Starkstein Sergio E. , Merello Marcelo , Jorge Ricardo , Brockman Simone , Bruce David , Power Brian
Published: May 2009

Although apathy is among the most frequent behavioral changes in Parkinson's disease (PD), its diagnosis is still problematic, and the overlap with depression and dementia poorly studied. Aim of the study was validate specific criteria to diagnose apathy in PD, and to examine its association with subsyndromes of depression and dementia. A series of 164 patients with PD, 44 patients with “primary” depression and no PD, 23 patients with Alzheimer's disease, and 26 age‐comparable healthy controls underwent a comprehensive psychiatric assessment that included a structured psychiatric interview and the Apathy Scale. A set of seven diagnostic criteria showed high sensitivity and specificity for clinically diagnosed apathy. Fifty‐two of the 164 patients with PD (32%) met diagnostic criteria for apathy. Eighty‐three percent of patients with apathy had comorbid depression and 56% had dementia. Only 5 of the 40 PD patients (13%) with neither depression nor dementia had apathy. We validated a set of standardized criteria for the diagnosis of apathy in PD. About one third of a series of patients attending a Movement Disorders Clinic showed apathy. Both depression and dementia were the most frequent comorbid conditions of apathy in PD. © 2009 Movement Disorder Society
A decade of functional brain imaging applied to bladder control
Authors: Fowler Clare J. , Griffiths Derek J.
Published: May 2009

Over the last 10 years functional brain imaging has emerged as the most powerful technique for studying human brain function. Although the literature is now vast, including studies of every imaginable aspect of cortical function, the number of studies that have been carried out examining brain control of bladder function is relatively limited. Nevertheless those that have been reported have transformed our thinking. This article reviews that development in the context of emerging ideas of interoception and a working model of brain activity during bladder filling and emptying is proposed. Some studies have also been carried out using functional imaging methods to examine pathophysiological bladder conditions or the effect of treatments and these are reviewed and future work anticipated. Neurourol. Urodynam. 29: 49–55, 2010. © 2009 Wiley‐Liss, Inc.
Comparative velocity investigations in cerebral arteries and aneurysms: 3D phase‐contrast MR angiography, laser Doppler velocimetry and computational fluid dynamics
Authors: Hollnagel Dorothea I. , Summers Paul E. , Poulikakos Dimos , Kollias Spyros S.
Published: May 2009

In western populations, cerebral aneurysms develop in approximately 4% of humans and they involve the risk of rupture. Blood flow patterns are of interest for understanding the pathogenesis of the lesions and may eventually contribute to deciding on the most efficient treatment procedure for a specific patient. Velocity mapping with phase‐contrast magnetic resonance angiography (PC‐MRA) is a non‐invasive method for performing in vivo measurements on blood velocity. Several hemodynamic properties can either be derived directly from these measurements or a flow field with all its parameters can be simulated on the basis of the measurements. For both approaches, the accuracy of the PC‐MRA data and subsequent modeling must be validated. Therefore, a realistic transient flow field in a well‐defined patient‐specific silicone phantom was investigated. Velocity investigations with PC‐MRA in a 3 Tesla MR scanner, laser Doppler velocimetry (LDV) and computational fluid dynamics (CFD) were performed in the same model under equal flow conditions and compared to each other. The results showed that PC‐MRA was qualitatively similar to LDV and CFD, but showed notable quantitative differences, while LDV and CFD agreed well. The accuracy of velocity quantification by PC‐MRA was best in straight artery regions with the measurement plane being perpendicular to the primary flow direction. The accuracy decreased in regions with disturbed flow and in cases where the measurement plane was not perpendicular to the primary flow. Due to these findings, it is appropriate to use PC‐MRA as the inlet and outlet conditions for numerical simulations to calculate velocities and shear stresses in disturbed regions like aneurysms, rather than derive these values directly from the full PC‐MRA measured velocity field. Copyright © 2009 John Wiley & Sons, Ltd.
Comparison between 20G and 22G needle for second trimester amniocentesis in terms of technical aspects and short‐term complications
Authors: Athanasiadis Apostolos P. , Pantazis Konstantinos , Goulis Dimitrios G. , Chatzigeorgiou Konstantinos , Vaitsi Violeta , Assimakopoulos Efstratios , Tzevelekis Filippos , Tsalikis Tryfon , Bontis John N.
Published: May 2009

Objective

To compare short‐term complications of amniocentesis using 20G versus 22G needle.

Methods

A total of 200 women referred for mid‐trimester amniocentesis were randomized to a 20G (Group I, n = 100) or 22G amniocentesis needle (Group II, n = 100). The primary outcome was intrauterine bleeding at needle insertion. The operator reported technical aspects and patient's reactions immediately after the procedure. Women's perception of discomfort 30 min after the procedure and complications after 2 weeks were recorded.

Results

Intrauterine bleeding at needle insertion was similar between groups (4/100 vs 8/100). When only transplacental taps were analyzed, bleeding was significantly lower in Group I (4/20 vs 8/14, p = 0.035). Fluid retrieval was faster in Group I (9.6 vs 26.8 sec, p < 0.001). In all, 65% of women in Group I versus 30% in Group II reported discomfort during the procedure, although discomfort 30 min after the procedure and complications within 2 weeks after the procedure were similar in the two groups.

Conclusion

Amniocentesis with 20G needle is associated with lower risk of intrauterine bleeding in case of transplacental needle insertion and allows for faster fluid retrieval, as compared with 22G needle. Nevertheless, 20G needle is associated with more immediate discomfort during the procedure. Copyright © 2009 John Wiley & Sons, Ltd.
Availability-Impact Analysis of Project Management Trends: Perspectives from Allied Disciplines
Authors: Kwak Young Hoon , Anbari Frank T.
Published: May 2009

The goal of this research was to analyze current and future trends of the allied management disciplines that influence project management. We asked academicians and practitioners about the availability of knowledge and the potential impact of allied disciplines on project management. We were able to assess where the allied disciplines currently stand in terms of availability and impact as well as make predictions about the future. The thoughts and visions collected from this research provide valuable insights for identifying trends in the allied disciplines and their impact on the future of project management, as well as opportunities, challenges, and obstacles.
Measuring Performance of Knowledge-Intensive Workgroups through Social Networks
Authors: Chung Kon Shing Kenneth , Hossain Liaquat
Published: May 2009

In this article, we examine the effect of social network position, structure, and ties on the performance of knowledge-intensive workers in dispersed occupational communities. Using structural holes and strength-of-tie theory, we develop a theoretical framework and a valid and reliable survey instrument. Second, we apply network and structural holes measures for understanding its association with performance. Empirical results suggest that degree centrality in a knowledge workers’ professional network positively influences performance use, whereas a highly constrained professional network is detrimental to performance. The findings show that social network structure and position are important factors to consider for individual performance.
Effect of humidity and temperature on nano/microtribolgical properties of perfluorinated carboxylic acid and hydrogenated carboxylic acid self‐assembled monolayers deposited on aluminum‐coated silicon substrate
Authors: Mo Yufei , Bai Mingwu
Published: May 2009

Two series of perfluorinated carboxylic acid (FC) and hydrogenated carboxylic acid (HC) self‐assembled monolayer (SAM) films were prepared on aluminum surfaces separately by chemical vapor deposition. The formation, structure and morphology of these films were characterized by measuring contact angle with ellipsometric method, x‐ray photoelectron spectrometry, and atomic force microscopy, respectively. FC and HC SAMs with long chains formed more densely packed films than those with short chains did. The comparative micro/nanoscale friction and adhesive properties of FC and HC SAMs, with various chain lengths on aluminum‐coated silicon substrate, were investigated. The influence of environmental conditions, such as relative humidity (RH) and temperature, on the friction and adhesion behavior was studied. Micro/nanotribological properties of the films were greatly influenced by their backbones and terminal groups. FC SAMs with long chain exhibited adhesion‐resistance, friction reduction, and environmental independence. Copyright © 2009 John Wiley & Sons, Ltd.
Efficient Adipocyte and Osteoblast Differentiation from Mouse Induced Pluripotent Stem Cells by Adenoviral Transduction
Authors: Tashiro Katsuhisa , Inamura Mitsuru , Kawabata Kenji , Sakurai Fuminori , Yamanishi Koichi , Hayakawa Takao , Mizuguchi Hiroyuki
Published: May 2009

Induced pluripotent stem (iPS) cells, which are generated from somatic cells by transducing four genes, are expected to have broad application to regenerative medicine. Although establishment of an efficient gene transfer system for iPS cells is considered to be essential for differentiating them into functional cells, the detailed transduction characteristics of iPS cells have not been examined. Previously, by using an adenovirus (Ad) vector containing the elongation factor-1α (EF-1α) and the cytomegalovirus enhancer/β-actin (CA) promoters, we developed an efficient transduction system for mouse embryonic stem (ES) cells and their aggregate form, embryoid bodies (EBs). In this study, we applied our transduction system to mouse iPS cells and investigated whether efficient differentiation could be achieved by Ad vector-mediated transduction of a functional gene. As in the case of ES cells, the Ad vector containing EF-1α and the CA promoter could efficiently transduce transgenes into mouse iPS cells. At 3,000 vector particles/cell, 80%–90% of iPS cells expressed transgenes by treatment with an Ad vector containing the CA promoter, without a decrease in pluripotency or viability. We also found that the CA promoter had potent transduction ability in iPS cell-derived EBs. Moreover, exogenous expression of a PPARγ gene or a Runx2 gene into mouse iPS cells by an optimized Ad vector enhanced adipocyte or osteoblast differentiation, respectively. These results suggest that Ad vector-mediated transient transduction is sufficient to increase cellular differentiation and that our transduction methods would be useful for therapeutic applications based on iPS cells.

Disclosure of potential conflicts of interest is found at the end of this article.
Noninvasive Bioluminescent Imaging Demonstrates Long-Term Multilineage Engraftment of Ex Vivo-Expanded CD34-Selected Umbilical Cord Blood Cells
Authors: Steiner David , Gelovani Juri , Savoldo Barbara , Robinson Simon N. , Decker William K. , Brouard Nathalie , Najjar Amer , Xing Dongxia , Yang Hong , Li Sufang , Marini Frank , Zweidler-McKay Patrick A. , Bollard Catherine M. , Shpall Elizabeth J. , Dotti Gianpietro , Simmons Paul J.
Published: May 2009

The use of umbilical cord blood (UCB) grafts for hematopoietic stem cell transplantation (HSCT) is a promising technique that permits a degree of human leukocyte antigen mismatch between the graft and the host without the concomitant higher rate of graft-versus-host disease that would be observed between an adult marrow graft and a mismatched host. A disadvantage to the use of UCB for HSCT is that immune reconstitution may be significantly delayed because of the low stem cell dose available in the graft. Ex vivo expansion of UCB CD34 cells would provide a greater number of stem cells; however, there are persistent concerns that ex vivo-expanded CD34 cells may lose pluripotency and the ability to contribute meaningfully to long-term engraftment. To address this issue, we transduced CD34-selected UCB cells with a lentiviral construct expressing luciferase, and determined homing and engraftment patterns in vivo by noninvasive bioluminescent imaging in sublethally irradiated NOD/SCID/IL-2Rγ−/− (NSG) mice. Graft contribution to multilineage commitment was also confirmed by analysis of primary and secondary transplants by flow cytometry and immunohistochemistry. Our results demonstrate that, other than a mild delay at the onset of engraftment, there were no significant differences in lineage repopulation or in long-term or secondary engraftment between culture-expanded and unexpanded UCB CD34-selected cells. The results suggest that multipotent stem cells can be expanded ex vivo and can contribute meaningfully to long-term hematopoietic engraftment.

Disclosure of potential conflicts of interest is found at the end of this article.
Regulation of endothelial cell functions by basement membrane‐ and arachidonic acid‐derived products
Authors: Pozzi Ambra , Zent Roy
Published: May 2009

Angiogenesis, the formation of new blood vessels from preexisting vasculature, is required for normal physiological as well as pathological events. The angiogenic process requires endothelial cells to proliferate, migrate, and undergo tubulogenesis. These multistep processes necessitate secretion of pro‐angiogenic growth factors, activation of specific intracellular signaling, and interaction of endothelial cells with basement membrane (BM) extracellular matrix components. The generation and release of angiogenic molecules are highly regulated and are influenced by numerous factors, including BM‐derived fragments, proteolytic enzymes, as well as metabolites of arachidonic acid (AA). The interactions between these key modulators of angiogenesis is extremely complex, as AA metabolites can regulate the synthesis of soluble angiogenic factors, BM components, as well as enzymes capable of cleaving BM components, which result in the generation of pro‐ and/or anti‐angiogenic products. Furthermore, some BM‐derived fragments can alter the expression of AA‐converting enzymes and consequently the synthesis of angiogenic factors. In this review we describe the relationship between BM components and AA metabolites with respect to the regulation of endothelial cell functions in health and disease. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Models of Systems Properties and Processes > Cellular Models

Developmental Biology > Developmental Processes in Health and Disease

Laboratory Methods and Technologies > Macromolecular Interactions, Methods

Biological Mechanisms > Regulatory Biology
Effect of Ionic Head Group on Admicelle Formation by Polymerizable Surfactants
Authors: Asnachinda Emma , Khaodhiar Sutha , Sabatini David A.
Published: April 2009

One of the problems of using surfactant‐modified adsorbents in a surfactant‐based adsorption process is loss of surfactant because of desorption. Recently, polymerizable surfactants have been used to minimize surfactant losses by polymerization of the surfactant admicellar structure to help secure it to the solid oxide surface. In this study, adsorption of polymerizable cationic gemini surfactant was used to form polymerized bilayers on silica. UV light was used to irradiate and initiate the polymerization process. Surfactant adsorption and desorption were evaluated to compare the efficiency of polymerized and non‐polymerized surfactants using gemini and conventional surfactants, respectively. Results demonstrate that the increased stability of the polymerized surfactant‐modified surface can reduce the desorption of surfactant from the surface, thereby improving operating characteristics of the surfactant‐modified media (e.g., maintaining adsolubilization potential, dispersion stability, etc.).
Profiling of Phytosterols, Tocopherols and Tocotrienols in Selected Seed Oils from Botswana by GC–MS and HPLC
Authors: Mitei Y. C. , Ngila J. C. , Yeboah S. O. , Wessjohann L. , Schmidt J.
Published: April 2009

The phytosterol, tocopherol, and tocotrienol profiles for mkukubuyo, Sterculia africana, manketti, Ricinodendron rautanenni, mokolwane, Hyphaene petersiana, morama, Tylosema esculentum, and moretologa‐kgomo, Ximenia caffra, seed oils from Botswana have been determined. Normal‐phase HPLC analysis of the unsaponifiable matter showed that among the selected oils, the most abundant tocopherol and tocotrienol were γ‐tocopherol (2232.99 μg/g) and γ‐tocotrienol (246.19 μg/g), detected in manketti and mkukubuyo, respectively. Mokolwane oil, however, contained the largest total tocotrienol (258.47 μg/g). Total tocol contents found in manketti, mokolwane, mkukubuyo, morama, and moretologa‐kgomo oils were 2238.60, 262.40, 246.20, 199.10, and 128.0 μg/g, respectively. GC–MS determination of the relative percentage composition of phytosterols showed 4‐desmethylsterols as the most abundant phytosterols in the oils, by occurring up to 90% in moretologa‐kgomo, mkukubuyo, and manketti seed oils, with β‐sitosterol being the most abundant. Mokolwane seed oil contained the largest percentage composition of 4,4‐dimethylsterols (45.93%). Besides 4‐desmethylsterols (75%), morama oil also contained significant amounts of 4,4‐dimethylsterols and 4‐monomethylsterols (15.72% total). GC–MS determination of the absolute amounts of 4‐desmethylsterols, after SPE fractionation of the unsaponifiable matter, confirmed that β‐sitosterol was the most abundant phytosterol in the test seed oils, with manketti seed oil being the richest source (1326.74 μg/g). The analysis showed total 4‐desmethylsterols content as 1617.41, 1291.88, 861.47, 149.15, and 109.11 μg/g for manketti, mokolwane, mkukubuyo, morama, and moretologa‐kgomo seed oils, respectively.
Co‐crystals of Beeswax and Various Vegetable Waxes with Sterols Studied by X‐ray Diffraction and Differential Scanning Calorimetry
Authors: Mellema Michel
Published: April 2009

In this study, mixtures of purified wax and sterols were melted and subsequently cooled. Using X‐ray diffraction of the mixed, solid phase, it was shown that for up to 30–40 wt% sterols no measurable re‐crystallisation of sterols occurred, i.e. the sterols became dissolved at a molecular level. Probably a form of amorphous co‐crystals of sterols and wax is formed if the molecular ratio does not exceed 1:1. Differential scanning calorimetry (DSC) suggests that a minor amount of pure sterols could already be present at lower sterol levels. This may be because of the higher temperature at which the microstructure is probed when using DSC—melting of the wax might lead to crystallisation of the sterols. For application in foods, the structure as probed by X‐rays at ambient temperatures is more relevant. When sunflower wax and rice bran wax are used, prevention of sterol crystallisation is even more pronounced, probably because the melting temperatures of these waxes are closer to the melting temperature of sterol crystals. Replacing the beeswax with a saturated fat (heRP70), sunflower oil, or jojoba wax (a liquid wax) substantially increases the amount of crystalline sterols. The difference between the various waxes and fats was qualitatively the same for X‐ray diffraction and DSC. Stanols can be incorporated in the same manner and up to similar concentrations. Another insoluble nutritional compound, ursolic acid, has a greater tendency to crystallise in wax. This is probably because the melting temperature of ursolic acid is much higher than that of wax.
Partitioning of Carboxylic Acid between Oil and Water Phases. Experimental, Correlation, and Prediction
Authors: Campanella Alejandrina , Mandagarán Beatriz A. , Campanella Enrique A.
Published: April 2009

Partition coefficients for the carboxylic acids (A) acetic and formic acids between oil and water were measured, correlated, and predicted. The experiments were conducted by equilibrating the systems, soybean oil (SO)–H2O–A and fatty acid methyl ester (FAME)–H2O–A, at 40 °C employing different compositions. The partition coefficients were correlated using the UNIQUAC model and, also, predicted by calculating the activity coefficients of the carboxylic acid in the two phases using a group contribution method, the UNIFAC equation. Agreement of experimental partition coefficients values with those estimated by UNIFAC are fair. Other experimental data from literature were also correlated and are discussed.
Origin of Albite Porphyroblasts in Rocks of the Ben More—Am-Binnein Area, Western Perthshire, Scotland
Authors: Jones K. A.
Published: May 2009

The eastern limit of a narrow belt of rocks, running from Co. Antrim through Cowal and into Perthshire, containing abundant albite porphyroblasts, has been mapped in detail. Albite is shown to have recrystallized as large porphyroblasts (up to 23 mm. in diameter in some cases) after the last main phase of deformation affecting these rocks. It is concluded that a large scale, late stage, regional metasomatism in the metamorphic history of the rocks of this area was the causal mechanism of the growth of albite porphyroblasts.
Ignimbrite flows from Rajula, Saurashtra, India
Authors: Krishnamacharlu T.
Published: May 2009

The paper records the occurrence of ignimbrite flows at Rajula, Amreli district of Saurashtra. Three different flows of ignimbrite representing a single genetic unit have been recognized. They consist of devitrified glass shards, pumice, salic and mafic minerals and unevenly distributed basic fragments. The shards and pumice are elongated along the flow direction of the rock giving eutaxitic foliation, while the basic fragments are drawn out in the direction of flow. The low content of soda in these ignimbrites is probably due to its loss during the hydration and devitrification of the glass.
The Ammonite Siphuncle
Authors: Trueman A. E.
Published: May 2009

It is well known that the chambers of Cephalopod shells are connected by an organ called the siphuncle, which passes through the septa by the septal necks. Many investigators who have studied these shells have made careful observations on the siphuncle, hoping thereby to throw light on its functions. Such workers as Branco, Blake, Zittel, and Owen, among many others, have written on this problem, while more recently an elaborate study of the structure and constitution of the siphuncle has been made by Grandjean, who gives a detailed account of the organs associated with it. Among the many points established by Grandjean's work, not the least interesting is the fact that the siphuncular tube of Ammonites and Belemnites is composed of calcium phosphate, and not, as had previously been stated, of calcium carbonate. But in spite of Grandjean's careful examination of the less obvious characters of the siphuncle, it appears that certain facts, much more easily observed, have hitherto been overlooked.
The Physiography of South-West Cornwall, the Distribution of Chalk Flints, and the Origin of the Gravels of Crousa Common
Authors: Hendriks E. M. Lind
Published: May 2009

A consideration of some unexplained physical features of both Devon and Cornwall does not hitherto appear to have been regarded as a line of approach towards various problems of Devono-Cornish geology still awaiting solution. Although the attempt is not yet by any means advanced, the results so far obtained appear of sufficient interest to communicate.
Laterite
Authors: Scrivenor J. B.
Published: May 2009

In the first place let us deal with the origin of the word. It was first used in 1807 by F. Buchanan in A Journey from Madras through Mysore, Canara, and Malabar. In dealing with the iron-ore seen during his journey he wrote:—“In all the hills of the country the ore is found forming beds, veins, or detached masses in the stratum of indurated clay, that is to be afterwards described, and of which the greater part of the hills of Malabar consists. … What I have called indurated clay … is one of the most valuable materials for building. It is diffused in immense masses, without any appearance of stratification, and is placed over the granite which forms the basis of Malayala. It is full of cavities and pores, and contains a very large quantity of iron in the form of red and yellow ochres. In the mass, while excluded from the air, it is so soft, that any iron instrument readily cuts it, and is dug up in square masses with a pickaxe, and immediately cut into the shape wanted with a trowel, or large knife. It very soon after becomes as hard as a brick, and resists the air and water much better than any bricks I have seen in India. … As it is usually cut into the form of bricks for building, in several of the native dialects it is called the brick stone. … The most proper English name would be Laterite, from Lateritis, the appellation that may be given to it in science.”
V.—On the Occurrence of a Mineral Allied to Enstatite in the Ancient Lavas of Eycott Hill, Cumberland
Authors: Bonney T. G.
Published: May 2009

This interesting series of ancient volcanic rocks is described by the late Mr. Clifton Ward in a paper on the Microscopic Structure of Ancient and Modern Volcanic Rocks, read before the Geological Society, in a Memoir of the Geological Survey on the Lake District, and, in greater detail, in a communication to the Royal Microscopical Society. All these are illustrated by figures (in no case very good) and some chemical analyses are given in the last-named paper. I went to the hill in the autumn of 1874 and collected a few specimens, but my visit was cut short by heavy rain. A few weeks since Mr. J. Postlethwaite of Keswick, to whose kindness I have been more than once indebted for additions to my collection, forwarded to me three specimens from Eycott Hill, thinking that I might not have any rocks therefrom, and called my attention to the peculiar reddish tint of the felspar in one of them, which, as he remarked, “resembled the colour of a garnet.” These were varieties of the well-known porphyritic lava of Eycott Hill, which is described by Mr. Ward as the second lava bed in ascending order, and as being above 100 feet thick. This specimen was obtained from a boulder on the hill. On examining it and comparing it with my own (at which I had not looked for some years), I was struck with the appearance of the ground-mass, which seemed to me unusually compact and more like that of an augite-andesite, than of a dolerite or diabase, as the rock is named by Mr. Ward. I had a slide prepared by Mr. Cuttell from Mr. Postlethwaite's specimen, in which I first discovered the mineral which is described in this note, and have since had some more cut from my own specimens from Eycott and others subsequently sent by him, and (for comparison) from the lavas of Falcon Crag near Derwentwater.
Basal Cambrian reworked phosphates from Spitsbergen (Norway) and their implications
Authors: Kidder D. L. , Swett K.
Published: May 2009

Several phosphatic zones are associated with the oldest remains of shelly fossils on the arctic island of Spitsbergen. The phosphate occurs as reworked nodules and layers associated with a disconformity. A gap in the acritarch biostratigraphic record supports a hiatus associated with the phosphatic zone. Palaeogeographic positions for Svalbard, both (1) as a single unit, and (2) as three isolated parts prior to Caledonian tectonism are consistent with conditions favourable to at least minimal amounts of upwelling. However, upwelling may not have been a prerequisite for development of these phosphate deposits. These phosphates were deposited in a nearshore shelf environmnt which contrasts with the outer shelf setting of many modern and recent phosphate deposits.

Geochemistry of the Lower Cambrian phosphates of Spitsbergen varies with the mode of phosphate occurrence. Concretionary phosphate clasts are chemically zoned such that their centres are enriched in P2O5 and CaO and are depleted in A12O3, SiO2, and K2O. Laminated and thinly bedded phosphate shows no chemical zonation within clasts. Phosphate cements are the most pure with respect to calcium phosphate.

This thin phosphatic zone of Svalbard is minor when compared with thicker and richer Lower Cambrian phosphate deposits, particularly those in the Soviet Union, Southeast Asia, and Australia. Coupled with the near absence of phosphate in some extensive Proterozoic to Lower Palaeozoic successions (e.g. western North America), this emphasizes the fact that widespread Lower Cambrian phosphate deposition was unevenly distributed. Althouth the Upper Proterozoic and Lower Cambrian are characterized by enhanced phosphogenesis, palaeogeographic position was also apparently critical to deposition of phosphatic sediments.
Explosive volcanism on Santorini, Greece
Authors: Druitt T. H. , Mellors R. A. , Pyle D. M. , Sparks R. S. J.
Published: May 2009

Abstrct

Santorini volcanic field has had 12 major (1–10 km3or more of magma), and numerous minor, explosive eruptions over the last ~ 200 ka. Deposits from these eruptions (Thera Pyroclastic Formation) are well exposed in caldera-wall successions up to 200 m thick. Each of the major eruptions began with a pumice-fall phase, and most culminated with emplacement of pyroclastic flows. Pyroclastic flows of at least six eruptions deposited proximal lag deposits exposed widely in the caldera wall. The lag deposits include coarse-grained lithic breccias (andesitic to rhyodacitic eruptions) and spatter agglomerates (andesitic eruptions only). Facies associations between lithic breccia, spatter agglomerate, and ignimbrite from the same eruption can be very complex. For some eruptions, lag deposits provide the only evidence for pyroclastic flows, because most of the ignimbrite is buried on the lower flanks of Santorini or under the sea. At least eight eruptions tapped compositionally heterogeneous magma chambers, producing deposits with a range of zoning patterns and compositional gaps. Three eruptions display a silicic–silicic + mafic–silicic zoning not previously reported. Four eruptions vented large volumes of dacitic or rhyodacitic pumice, and may account for 90% or more of all silicic magma discharged from Santorini. The Thera Pyroclastic Formation and coeval lavas record two major mafic-to-silicic cycles of Santorini volcanism. Each cycle commenced with explosive eruptions of andesite or dacite, accompanied by construction of composite shields and stratocones, and culminated in a pair of major dacitic or rhyodacitic eruptions. Sequences of scoria and ash deposits occur between most of the twelve major members and record repeated stratocone or shield construction following a large explosive eruption.

Volcanism at Santorini has focussed on a deep NE–SW basement fracture, which has acted as a pathway for magma ascent. At least four major explosive eruptions began at a vent complex on this fracture. Composite volcanoes constructed north of the fracture were dissected by at least three caldera-collapse events associated with the pyroclastic eruptions. Southern Santorini consists of pryoclastic ejecta draped over a pre-volcanic island and a ridge of early- to mid-Pleistocene volcanics. The southern half of the present-day caldera basin is a long-lived, essentially non-volcanic, depression, defined by topographic highs to the south and east, but deepened by subsidence associated with the main northern caldera complex, and is probably not a separate caldera.
Acritarch dating of latest Tremadoc – earliest Arenig (early Ordovician) sediments in the Carmarthen district, south Wales
Authors: Molyneux S. G. , Dorning K. J.
Published: May 2009

An acritarch assemblage from beds beneath the Ogof Hên Formation near Carmarthen (the ‘Login beds’) resembles assemblages from the Watch Hill Grits and underlying sediments of latest Tremadoc or earliest Arenig age in the Skiddaw Group of the English Lake District. We conclude that the Login acritarch assemblage is younger than at least some part of the late Tremadoc Angelina sedgwickii Biozone, but older than the early Arenig Didymograptus deflexus Biozone. Its occurrence may therefore coincide with that of the graptolite Tetragraptus approximatus. This is of particular significance in any attempt to define an internationally correlatable base for the Arenig Series in Britain.
The margin of a Middle Pleistocene ice advance at Tottenhill, Norfolk, England
Authors: Gibbard P. L. , West R. G. , Andrew R. , Pettit M.
Published: May 2009

Exposures at Tottenhill quarry, west Norfolk, are described. Detailed sediment logs, lateral sediment distribution and facies relationships are presented, together with palaeocurrent measurements and pebble counts. It is concluded that the sequence represents a delta-like subaquatic fan accumulation that was deposited by glacier meltwater at the eastern margin of the present Fenland. The ice must have entered the area from the west to northwest. An arctic leaf flora is associated with still water pool sediments within the fan sequence. Pollen assemblages appear to be largely derived by reworking from underlying in situ temperate stage sediments which are correlated with the Hoxnian Stage.

The age of the deposits is discussed and it is concluded that the glaciation concerned must date from the early part of the Wolstonian Stage on the basis of the previously established stratigraphical sequence in the area.