bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumor cell-derived PDGF-B potentiates mouse mesenchymal stem cells-pericytes transition and recruitment through an interaction with NRP-1
Authors: Dhar Kakali , Dhar Gopal , Majumder Monami , Haque Inamul , Mehta Smita , Van Veldhuizen Peter J , Banerjee Sushanta K , Banerjee Snigdha
Published: August 2010

Background

New blood vessel formation, or angiogenic switch, is an essential event in the development of solid tumors and their metastatic growth. Tumor blood vessel formation and remodeling is a complex and multi-step processes. The differentiation and recruitment of mural cells including vascular smooth muscle cells and pericytes are essential steps in tumor angiogenesis. However, the role of tumor cells in differentiation and recruitment of mural cells has not yet been fully elucidated. This study focuses on the role of human tumor cells in governing the differentiation of mouse mesenchymal stem cells (MSCs) to pericytes and their recruitment in the tumor angiogenesis process.

Results

We show that C3H/10T1/2 mouse embryonic mesenchymal stem cells, under the influence of different tumor cell-derived conditioned media, differentiate into mature pericytes. These differentiated pericytes, in turn, are recruited to bind with capillary-like networks formed by endothelial cells on the matrigel under in vitro conditions and recruited to bind with blood vessels on gel-foam under in vivo conditions. The degree of recruitment of pericytes into in vitro neo-angiogenesis is tumor cell phenotype specific. Interestingly, invasive cells recruit less pericytes as compared to non-invasive cells. We identified tumor cell-secreted platelet-derived growth factor-B (PDGF-B) as a crucial factor controlling the differentiation and recruitment processes through an interaction with neuropilin-1 (NRP-1) in mesenchymal stem cells.

Conclusion

These new insights into the roles of tumor cell-secreted PDGF-B-NRP-1 signaling in MSCs-fate determination may help to develop new antiangiogenic strategies to prevent the tumor growth and metastasis and result in more effective cancer therapies.
Spatiotemporal patterns of macrophage migration inhibitory factor (Mif) expression in the mouse placenta
Authors: Faria Miriam R , Hoshida Mara S , Ferro Eloisa AV , Ietta Francesca , Paulesu Luana , Bevilacqua Estela
Published: August 2010

Background

Macrophage migration inhibitory factor (MIF) has special pro-inflammatory roles, affecting the functions of macrophages and lymphocytes and counter-regulating the effects of glucocorticoids on the immune response. The conspicuous expression of MIF during human implantation and early embryonic development also suggests this factor acts in reproductive functions. The overall goal of this study was to evaluate Mif expression by trophoblast and embryo placental cells during mouse pregnancy.

Methods

Mif was immunolocalized at implantation sites on gestation days (gd) 7.5, 10.5, 13.5 and 17.5. Ectoplacental cones and fetal placentas dissected from the maternal tissues were used for Western blotting and qRT-PCR assays on the same gestation days.

Results

During the post-implantation period (gd7.5), trophoblast giant cells showed strong Mif reactivity. In later placentation phases (gds 10.5-17.5), Mif appeared to be concentrated in the junctional zone and trophoblast giant cells. Mif protein expression increased significantly from gd7.5 to 10.5 (p = 0.005) and from gd7.5 to 13.5 (p = 0.03), remaining at high concentration as gestation proceeded. Higher mRNA expression was found on gd10.5 and was significantly different from gd13.5 (p = 0.048) and 17.5 (p = 0.009).

Conclusions

The up-regulation of Mif on gd10.5 coincides with the stage in which the placenta assumes its three-layered organization (giant cells, spongiotrophoblast and labyrinth zones), fetal blood circulation begins and population of uNK cells reaches high proportions at the maternal counter part of the placenta, suggesting that Mif may play a role in either the placentation or in the adaptation of the differentiated placenta to the uterus or still in gestational immunomodulatory responses. Moreover, it reinforces the possibility of specific activities for Mif at the maternal fetal interface.
The Endogenous Actions of Hypothalamic Peptides on Brown Adipose Tissue Thermogenesis in the Rat
Authors: Verty Aaron N. A. , Allen Andrew M. , Oldfield Brian J.
Published: August 2010

Although the neuronal pathways within the hypothalamus critical in controlling feeding and energy expenditure and projecting to brown adipose tissue (BAT) have been identified and their peptidergic content characterized, endogenous action of such peptides in the control of BAT activity has not been elucidated. Here male Sprague Dawley rats received infusions of either melanin-concentrating hormone antagonist (SNAP-7941) (1 μg/μl · h), orexin A receptor antagonist (SB-334867-A; 1 μg/μl · h), combined SB-334867-A (1 μg/μl · h), and SNAP-7941 (1 μg/μl · h), or melanocortin-3/4 receptor antagonist (SHU9119) (1 μg/μl · h) via an indwelling cannula in the lateral ventricle attached to sc implanted osmotic minipump. BAT temperature, physical activity, body weight, food intake, and changes in uncoupling protein (UCP)-1 were measured. SB-334867-A and SNAP-7941 significantly increased BAT temperature and UCP1 expression and reduced food intake and body weight. Combined infusion of SB-334867-A and SNAP-7941 produced a pronounced response that was greater than the addition of the individual effects in all parameters measured. SHU9119 significantly decreased BAT temperature and UCP1 expression and increased feeding and body weight. In a second series of experiments, the effect of SB-334867-A and SNAP-7941 alone or combination on the expression of the Fos protein was determined. SB-334867-A and SNAP-7941 increased Fos expression in key hypothalamic and brainstem feeding-related regions. In combination, these antagonists produced a greater than additive elevation of Fos expression in most of the regions evaluated. These findings support a role for endogenous orexigenic and anorexigenic hypothalamic peptides acting in concert to create a thermogenic tone via BAT activity.
An Inositol 1,4,5-Triphosphate (IP3)-IP3 Receptor Pathway Is Required for Insulin-Stimulated Glucose Transporter 4 Translocation and Glucose Uptake in Cardiomyocytes
Authors: Contreras-Ferrat A. E. , Toro B. , Bravo R. , Parra V. , Vásquez C. , Ibarra C. , Mears D. , Chiong M. , Jaimovich E. , Klip A. , Lavandero S.
Published: August 2010

Intracellular calcium levels ([Ca2+]i) and glucose uptake are central to cardiomyocyte physiology, yet connections between them have not been studied. We investigated whether insulin regulates [Ca2+]i in cultured cardiomyocytes, the participating mechanisms, and their influence on glucose uptake via SLC2 family of facilitative glucose transporter 4 (GLUT4).

Primary neonatal rat cardiomyocytes were preloaded with the Ca2+ fluorescent dye fluo3-acetoxymethyl ester compound (AM) and visualized by confocal microscopy. Ca2+ transport pathways were selectively targeted by chemical and molecular inhibition. Glucose uptake was assessed using [3H]2-deoxyglucose, and surface GLUT4 levels were quantified in nonpermeabilized cardiomyocytes transfected with GLUT4-myc-enhanced green fluorescent protein.

Insulin elicited a fast, two-component, transient increase in [Ca2+]i. Nifedipine and ryanodine prevented only the first component. The second one was reduced by inositol-1,4,5-trisphosphate (IP3)-receptor-selective inhibitors (xestospongin C, 2 amino-ethoxydiphenylborate), by type 2 IP3 receptor knockdown via small interfering RNA or by transfected Gβγ peptidic inhibitor βARKct. Insulin-stimulated glucose uptake was prevented by bis(2-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid-AM, 2-amino-ethoxydiphenylborate, and βARK-ct but not by nifedipine or ryanodine. Similarly, insulin-dependent exofacial exposure of GLUT4-myc-enhanced green fluorescent protein was inhibited by bis(2-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid-AM and xestospongin C but not by nifedipine. Phosphatidylinositol 3-kinase and Akt were also required for the second phase of Ca2+ release and GLUT4 translocation. Transfected dominant-negative phosphatidylinositol 3-kinase γ inhibited the latter.

In conclusion, in primary neonatal cardiomyocytes, insulin induces an important component of Ca2+ release via IP3 receptor. This component signals to glucose uptake via GLUT4, revealing a so-far unrealized contribution of IP3-sensitive Ca2+ stores to insulin action. This pathway may influence cardiac metabolism in conditions yet to be explored in adult myocardium.
Dual Targeting of Tumor and Endothelial Cells by Gonadotropin-Releasing Hormone Agonists to Reduce Melanoma Angiogenesis
Authors: Moretti Roberta M. , Mai Stefania , Montagnani Marelli Marina , Bani Maria R. , Ghilardi Carmen , Giavazzi Raffaella , Taylor Deanne M. , Martini Paolo G. V. , Limonta Patrizia
Published: August 2010

We showed previously that GnRH receptors are expressed in melanoma cells; their activation reduces cell growth and metastatic behavior. Here, we investigated whether GnRH agonists might affect the expression of genes involved in melanoma progression. By genome-wide transcriptomic and real-time PCR analysis, we first observed that GnRH agonists decrease the expression of the pro-angiogenic factor vascular endothelial growth factor (VEGF) (all isoforms) in BLM melanoma cells. Then, we demonstrated that GnRH agonists specifically decrease the expression of the VEGF165 isoform as well as its secretion from BLM cells. These data suggested that activation of GnRH receptors might reduce the pro-angiogenic behavior of melanoma cells. To verify this hypothesis, we treated BLM cells with a GnRH agonist; the conditioned medium from these cells was tested to assess its capability to stimulate human umbilical vein endothelial cell (HUVEC) motility. The migration of HUVECs towards the conditioned medium of GnRH agonist-treated BLM cells was significantly lower than the migration of HUVECs toward the conditioned medium of untreated cells. Thus, GnRH agonists reduce the pro-angiogenic behavior of melanoma cells through a decreased production of bioactive VEGF. We then found that GnRH receptors are also expressed on HUVECs and that GnRH agonists reduce their ability to proliferate and to form capillary-like tubes when stimulated by VEGF. These findings suggest that GnRH agonists exert an anti-angiogenic activity indirectly by decreasing VEGF secretion from tumor cells and directly by counteracting the pro-angiogenic activity of the growth factor. These data might lead to the development of novel targeted approaches for melanoma.
Production of Proinflammatory Cytokines and Chemokines During Neuroinflammation: Novel Roles for Estrogen Receptors α and β
Authors: Brown Candice M. , Mulcahey Tara A. , Filipek Nicole C. , Wise Phyllis M.
Published: August 2010

Neuroinflammation is a common feature of many neurological disorders, and it is often accompanied by the release of proinflammatory cytokines and chemokines. Estradiol-17β (E2) exhibits antiinflammatory properties, including the suppression of proinflammatory cytokines, in the central nervous system. However, the mechanisms employed by E2 and the role(s) of estrogen receptors (ERs) ERα and ERβ are unclear. To investigate these mechanisms, we employed an in vivo lipopolysaccharide (LPS) model of systemic inflammation in ovariectomized (OVX) and OVX and E2-treated (OVX+E2) mice. Brain levels of proinflammatory cytokines (IL-1β, IL-6, and IL-12p40) and chemokines (CCL2/MCP-1, CCL3/MIP-1α, CCL5/RANTES, and CXCL1/KC) were quantified in mice at 0 (sham), 3, 6, 12, and 24 h after infection using multiplex protein analysis. E2 treatment inhibited LPS-induced increases in all cytokines. In contrast, E2 treatment only suppressed CCL/RANTES chemokine concentrations. To determine whether ERα and ERβ regulate brain cytokine and chemokine levels, parallel experiments were conducted using ERα knockout and ERβ knockout mice. Our results revealed that both ERα and ERβ regulated proinflammatory cytokine and chemokine production through E2-dependent and E2-independent mechanisms. To assess whether breakdown of the blood-brain barrier is an additional target of E2 against LPS-induced neuroinflammation, we measured Evan’s blue extravasation and identified distinct roles for ERα and ERβ. Taken together, these studies identify a dramatic cytokine- and chemokine-mediated neuroinflammatory response that is regulated through ERα- and ERβ-mediated ligand-dependent and ligand-independent mechanisms.
Contribution of a Membrane Estrogen Receptor to the Estrogenic Regulation of Body Temperature and Energy Homeostasis
Authors: Roepke Troy A. , Bosch Martha A. , Rick Elizabeth A. , Lee Benjamin , Wagner Edward J. , Seidlova-Wuttke Dana , Wuttke Wolfgang , Scanlan Thomas S. , Rønnekleiv Oline K. , Kelly Martin J.
Published: August 2010

The hypothalamus is a key region of the central nervous system involved in the control of homeostasis, including energy and core body temperature (Tc). 17β-Estradiol (E2) regulates Tc, in part, via actions in the basal hypothalamus and preoptic area. E2 primarily controls hypothalamic functions via the nuclear steroid receptors, estrogen receptor α/β. However, we have previously described an E2-responsive, Gq-coupled membrane receptor that reduces the postsynaptic inhibitory γ-aminobutyric acid-ergic tone and attenuates postovariectomy body weight gain in female guinea pigs through the administration of a selective Gq-mER ligand, STX. To determine the role of Gq-mER in regulating Tc, energy and bone homeostasis, ovariectomized female guinea pigs, implanted ip with temperature probes, were treated with STX or E2 for 7–8 wk. Tc was recorded for 4 wk, whereas food intake and body weight were monitored daily. Bone density and fat accumulation were determined postmortem. Both E2 and STX significantly reduced Tc in the females compared with controls. STX, similar to E2, reduced food intake and fat accumulation and increased tibial bone density. Therefore, a Gq-mER-coupled signaling pathway appears to be involved in maintaining homeostatic functions and may constitute a novel therapeutic target for treatment of hypoestrogenic symptoms.
Oxidative Stress Stimulates Apoptosis and Activates NF-κB in Osteoblastic Cells via a PKCβ/p66shc Signaling Cascade: Counter Regulation by Estrogens or Androgens
Authors: Almeida Maria , Han Li , Ambrogini Elena , Bartell Shoshana M. , Manolagas Stavros C.
Published: August 2010

Aging or acute loss of estrogens or androgens increases the levels of reactive oxygen species, activates nuclear factor-κB (NF-κB), and promotes the phosphorylation of p66shc, a redox enzyme that amplifies mitochondrial reactive oxygen species generation and stimulates apoptosis. We report that in mesenchymal progenitor and osteoblastic cell models, H2O2 activated a protein kinase C (PKC)β/p66shc/NF-κB signaling cascade and that p66shc was an essential mediator of the stimulating effects of H2O2 on the apoptosis of osteoblastic cells as well as their ability to activate NF-κB. 17β-Estradiol (E2) or the nonaromatizable androgen dihydrotestosterone abrogated the effects of H2O2 on p66shc and NF-κB activation by attenuating the phosphorylation of the redox-sensitive cytoplasmic kinase PKCβ. Additionally, both E2 and dihydrotestosterone prevented H2O2-induced apoptosis by a mechanism that involved attenuation of p66shc resulting from decreased phosphorylation of PKCβ. Consistent with a kinase-mediated mechanism of sex steroid action, the effects of E2 were reproduced by a polymeric form of estradiol that is not capable of stimulating the nuclear-initiated actions of ERα. These results demonstrate that p66shc is an essential mediator of the effects of oxidative stress on osteoblastic cell apoptosis, NF-κB activation, and cytokine production. The ability of either estrogen or androgen to attenuate the effects of oxidative stress on osteoblastic cell apoptosis, NF-κB activation, and cytokine production results from their common property to suppress PKCβ-induced p66shc phosphorylation via a mechanism that does not require stimulation of the nuclear-initiated actions of sex steroids.
Historical Reflections on Dawn: An Interview with Gita Sen
Authors: Tambe Ashwini , Trotz Alissa
Published: August 2010

In an interview, Gita Sen, a founding member of DAWN (Development Alternatives with Women for a New Era), reflects on the network's two and a half decades of experience connecting scholars, policy advocates, and activists in Africa, Latin America, the Caribbean, Asia, and the Pacific. Focusing on DAWN's praxis over three phases of the network's life, Sen comments on DAWN's continuing relationship to a variety of states and the United Nations. She describes DAWN members' Marxist-feminist critique of the structural location of the state, their opposition to liberal feminism and neoliberal state policies, and also their effort to create public policies sensitive to feminist concerns. Sen emphasizes the necessity of being attentive to interlinkages and tensions among the host of issues that the network confronts, such as trade policy and sexual and reproductive health rights.
Introduction: Gender and Empire
Authors: Mojab Shahrzad
Published: August 2010

The articles in this collection, covering the diverse regions of Afghanistan, Egypt, and Palestine, engage in questions concerning gender and human rights discourses, anticolonial and anti-imperialist resistance, and religious and political fundamentalisms. They also discuss “colonial feminism” and “imperialist feminism” in the context of current wars and occupation in the Middle East, examine the mutually reinforcing yet conflicting relationships between regressive forces in the West and the Middle East, and consider the place of gender analysis in the debate on “empire” and “imperialism.” The articles in this special section, as well as the literature cited in this introduction, warn us that, in spite of the proliferation of nongovernmental organizations (NGOs), the conditions of women's lives are deteriorating and levels and forms of exploitation are on the rise. Women, whether under war and occupation in Iraq, Palestine, or Afghanistan or in the marketplace of NGOs, continue to suffer from the rule of capital in its imperialist expansion. The amount of critical literature on the role of women's NGOs is limited and needs to be expanded, to delve deeper into questions of how women's NGOs fit into the continuation of the production of capital and labor and the furthering of imperialism.
Between the Elusive and the Illusionary: Donors' Empowerment Agendas in the Middle East in Perspective
Authors: Tadros Mariz
Published: August 2010

This article examines the notion of empowerment as it has been conceptualized, operationalized, and applied through various programs and projects by some donors funding women- and gender-related projects in the Middle East between 1998 and 2008. The main argument put forward is that many projects claiming empowerment as their objective showed a support for the concept that is stripped of its original political underpinnings. The article argues that this depoliticization of empowerment aid is not coincidental but is the outcome of a series of policy concerns shaping the donor agenda. These concerns include placating authoritarian regimes, promoting economic liberalization, and finding progovernment institutions capable of absorbing (and channeling) large amounts of aid in short periods of time. The outcome is a re-reinforcement of the status quo domestically, while giving the international audience the facade of progressive, gender-sensitive regimes.
Sacred Cows and Secular History: Cow Protection Debates in Colonial North India
Authors: Adcock C. S.
Published: August 2010

Proponents of cow protection in colonial north India around the turn of the twentieth century made abundant use of “economic” arguments for a legislative ban on cow slaughter. Drawing on recent critical reflections on secular history, this essay explores what it might mean to take these economic arguments seriously.
Wnt signaling promotes oral but suppresses aboral structures in Hydractinia metamorphosis and regeneration
Authors: Duffy David J. , Plickert Günter , Kuenzel Timo , Tilmann Wido , Frank Uri
Published: August 2010

We studied the role of Wnt signaling in axis formation during metamorphosis and regeneration in the cnidarian Hydractinia. Activation of Wnt downstream events during metamorphosis resulted in a complete oralization of the animals and repression of aboral structures (i.e. stolons). The expression of Wnt3, Tcf and Brachyury was upregulated and became ubiquitous. Rescue experiments using Tcf RNAi resulted in normal metamorphosis and quantitatively normal Wnt3 and Brachyury expression. Isolated, decapitated polyps regenerated only heads but no stolons. Activation of Wnt downstream targets in regenerating animals resulted in oralization of the polyps. Knocking down Tcf or Wnt3 by RNAi inhibited head regeneration and resulted in complex phenotypes that included ectopic aboral structures. Multiple heads then grew when the RNAi effect had dissipated. Our results provide functional evidence that Wnt promotes head formation but represses the formation of stolons, whereas downregulation of Wnt promotes stolons and represses head formation.
BMPs and FGFs target Notch signalling via jagged 2 to regulate tooth morphogenesis and cytodifferentiation
Authors: Mitsiadis Thimios A. , Graf Daniel , Luder Hansueli , Gridley Thomas , Bluteau Gilles
Published: August 2010

The Notch signalling pathway is an evolutionarily conserved intercellular signalling mechanism that is essential for cell fate specification and proper embryonic development. We have analysed the expression, regulation and function of the jagged 2 (Jag2) gene, which encodes a ligand for the Notch family of receptors, in developing mouse teeth. Jag2 is expressed in epithelial cells that give rise to the enamel-producing ameloblasts from the earliest stages of tooth development. Tissue recombination experiments showed that its expression in epithelium is regulated by mesenchyme-derived signals. In dental explants cultured in vitro, the local application of fibroblast growth factors upregulated Jag2 expression, whereas bone morphogenetic proteins provoked the opposite effect. Mice homozygous for a deletion in the Notch-interaction domain of Jag2 presented a variety of severe dental abnormalities. In molars, the crown morphology was misshapen, with additional cusps being formed. This was due to alterations in the enamel knot, an epithelial signalling structure involved in molar crown morphogenesis, in which Bmp4 expression and apoptosis were altered. In incisors, cytodifferentiation and enamel matrix deposition were inhibited. The expression of Tbx1 in ameloblast progenitors, which is a hallmark for ameloblast differentiation and enamel formation, was dramatically reduced in Jag2−/− teeth. Together, these results demonstrate that Notch signalling mediated by Jag2 is indispensable for normal tooth development.
Supercritical Hydrothermal Synthesis of Carboxylic Acid-surface-functionalized TiO2 Nanocrystals: pH Sensitive Dispersion and Hybridization with Organic Compounds
Authors: Arita Toshihiko , Moriya Ken-ichi , Minami Kimitaka , Naka Takashi , Adschiri Tadafumi
Published: August 2010

Surface-functionalized TiO2 (anatase) nanocrystals (NCs) (avg. d = 6.7 ± 1.6 nm) were synthesized by a supercritical hydrothermal method. A phosphonic acid derivative was used as surface modifier of TiO2 NCs. It was verified that the phosphonic acids were bound to the surface of TiO2 with very strong binding energy. The TiO2 NCs also exhibited extraordinarily high chemical stability. Such a strong binding between the phosphonic acid modifier and TiO2 had not been obtained by any other methods. The TiO2 NC showed sharp pH sensitive dispersion. Because of the functional as well as stable surface modifier layer, further manipulations on the surface using chemical reagents could be possible.
Selective Methanation of CO in Reformate Gas over Ni/TiO2 Catalyst
Authors: Urasaki Kohei , Tanpo Yuta , Takahiro Tomoki , Christopher Jayaraj , Kikuchi Ryuji , Kojima Toshinori , Satokawa Shigeo
Published: August 2010

Selective methanation of CO was performed over Ni/TiO2. CO in reformate gas was completely removed at 150–300 °C. The CH4 concentration in the outlet gas could be maintained below 1% in the entire temperature region because Ni/TiO2 suppressed the CO2 methanation reaction. It can be considered that the formation of CO by the reverse water-gas-shift reaction is blocked by the application of TiO2 to the support of Ni catalyst and that it results in the high CO/CO2 selectivity of Ni/TiO2.
Geochemical Characteristics of Natural Gas in the Yinggehai-Qiongdongnan Basin, South China Sea
Authors: Liao Fengrong , Wu Xiaoqi , Huang Shipeng
Published: August 2010

Geochemical characteristics of natural gas in the Yinggehai-Qiongdongnan Basin were studied and analyzed based on gas component properties and carbon isotopic characteristics which were tested and collected of more than 100 samples. The gas in the Yinggehai-Qiongdongnan Basin was generally alkane gas, and all the area showed dry gas characteristics except Yanan Depression and its periphery area. The gas in the Basin is mainly high mature -over mature coal formed gas except Songnan and eastern of the second fault belt. There are three genetic types of the natural gas in the Yinggehai-Qiongdongnan Basin, such as microbial gas, coal-formed gas and the mixture of them. The coal-formed gas is the main genetic type.
Geochemical Characteristics of Carboniferous-Permian Coal-Formed Gas in Bohai Bay Basin
Authors: Huang Shipeng , Liao Fengrong , Wu Xiaoqi
Published: August 2010

Coal-formed gas reservoirs have been found in several depressions in Bohai Bay Basin. The gas was mainly generated by the Carboniferous-Permian coal measures, which are good source rocks. The exploration of coal-formed gas has a broad prospect. The main reservoirs of the coal-formed gas are Ordovician, Carboniferous-Permian, and Paleogene stratum. Coal-formed gas in the Bohai Bay Basin is chiefly composed of hydrocarbon gases. The percentage content of carbon dioxide is more than that of the nitrogen gas. The stable carbon isotope values of the hydrocarbon gases of different depressions and different reservoirs usually reversed. The reversed values of gas samples account for 52.1% of all the samples. Reversion values of the carbon isotope are mainly because of the mixing of gases from same source rocks but with different maturity. Among the three main reservoirs, coal-formed gas preserved in Paleogene stratum has the heaviest carbon isotope, the second is the gas in Carboniferous-Permian stratum, and the Ordovician gas possesses the lightest carbon isotope. Based on the analysis of the characteristics of carbon isotope of hydrocarbon gases in well Qishen-1 and the distribution of the Carboniferous-Permian coal measures, the gas of the well is derived from the high-matured Carboniferous-Permian coal measures.
Wavelet Denoising of Well Logs and its Geological Performance
Authors: Yu Jifeng , Guo Kai , Yuan Xuexu , Fu Wenzhao , Xun Zhifeng
Published: August 2010

Well logs play a very important role in exploration and even exploitation of energy resources, but they usually contain kinds of noises which affect the results of the geological interpretation of them. It is common knowledge that wavelet transform does better than Fourier transform in noise removal and suppression of such non-stationary signals as logging signals. However, there are variable choices of the parameters such as the wavelet basis (mother wavelet function), the thresholding rule and the decomposition level etc. in denoising with the wavelet transform. In this paper, the wavelet denoising theory and steps are briefly introduced first, and then lots of numerical experiments on real well logs were done by the authors with different combination of the parameters and the denoising effect analyzed by comparison of the differences between the pre-denoising and post-denoising signals with difference value calculation and frequency spectral analysis. The experiment results show that the wavelet basis ‘sym8’, the soft threshold rule ‘heursure’ and 5-level decomposition are outstanding in the wavelet denoising of well logging data. Furthermore, we took the AC (acoustic logs) well logging data of a certain borehole in Jiyang Depression, Shandong province of North China, for a case study to check the combination of the parameters settled above. It is found that the denoised acoustic logging signal outperforms the original one in revealing the geological information of gas bearing layers. So, we believe that the wavelet transform can do an excellent job in the denoising of well logs on condition that the related parameters are set properly. Also, the authors assume that it would be of bright prospect to extract and reveal some more geological information such as stratigraphic sequences, sedimentary facies and reservoir properties etc. with reasonable denoising process of different kinds of logging data at certain scales.
A Novel Method to Calculate the Dynamic Reliability of Space Structures Subjected to Multi-Dimensional Multi-Support Excitations
Authors: Chun-Guang Liu , Hui-Jun Li
Published: August 2010

Extensively researches have been carried out on seismic analysis of space structures subjected to multi-dimensional multi-support excitations. However, the research on dynamic reliability of stochastic response is just little. Extreme value distribution (EVD) of dynamic response of stochastic space structures is so necessary to dynamic reliability. Nevertheless, there is no effective approach to obtain EVD as yet. Hence the recently formulated probability density evolution method (PDEM) is adopted to obtain the EVD and subsequently evaluate dynamic reliability of space structure subjected to multi-dimensional multi-support excitations. PDEM can effectively gain the EVD and calculate the dynamic reliability of stochastic structures. To demonstrate the accuracy and efficiency of the PDEM in space structures, a single-layer spherical reticulated dome is extensively researched and the EVD and dynamic reliability is observed and analyzed, respectively. In the present paper five apparent wave velocities and four displacement thresholds in vertical direction are taken into consideration. Compared with the results evaluated by conventional simulation method, the PDEM is of accuracy, efficiency and versatility in space structures.
The Thermodynamic Relationship between Surface Temperature and Water Vapor Concentration in the Troposphere
Authors: Gilbert William C.
Published: August 2010

The theoretical and empirical thermodynamics discussed in this paper explain the physics behind the observed reduction in relative humidity in the upper troposphere as surface temperature and surface humidity increase. This contradicts the physics embedded in current GCM models commonly used by the climate science community. The key to the physics discussed in this paper is the understanding of the relationship between water vapor condensation and the resulting PV work energy distribution under the influence of a gravitational field. New analyses of empirical, observational radiosonde data are presented which show the relationship between thermal energy and PV work energy resulting from this water vapor condensation process.
Applied Element Method Analysis of Porous GFRP Barrier Subjected to Blast
Authors: Asprone D. , Nanni A. , Salem H. , Tagel-Din H.
Published: August 2010

Numerical analysis of highly dynamic phenomena represents a critical field of study and application for structural engineering as it addresses extreme loading conditions on buildings and the civil infrastructure. In fact, large deformations and material characteristics of elements and structures different from those exhibited under static loading conditions are important phenomena to be accounted for in numerical analysis. The present paper describes the results of detailed numerical analyses simulating blast tests conducted on a porous (i.e. discontinuous) glass fiber reinforced polymer (GFRP) barrier aimed at the conception, validation and deployment of a protection system for airport infrastructures against malicious disruptions. The numerical analyses herein presented were conducted employing the applied element method (AEM). This method adopts a discrete crack approach that allows auto cracking, separation and collision of different elements in a dynamic scheme, where fully nonlinear path-dependant constitutive material models are adopted. A comparison with experimental results is presented and the prediction capabilities of the software are demonstrated.
Buckling Strength of Tie-Struts and Application to Frame Girders
Authors: Chen Shaofan
Published: August 2010

Tie–struts are members subject partly to axial compression and partly to axial tension within the two end supports and appear in the chords of lattice girders of rigid frames. There are three types of tie-strut with different patterns of force distribution. The bearing capacity of these members has to be determined by stability calculation. Although the current Chinese code of cold-formed thin-wall steel structures GB50018 provides a formula for calculating tie-strut chords, it can only be used for the stability check of one of the three types. In this study, analytical equations of elastic critical load are firstly derived, based on those of struts subject to compression varying by step and then parametric analyses were carried out and practical formulas for member effective length are obtained through curve fitting for each of the three types. The recommended formulas have good accuracy and can be used in design work. The second part of this study covers the application of tie-strut buckling calculation to solid-web frame girders. Similar to strut analogy in beam buckling, a tie-strut analogy is developed for frame plate girders and this approach is especially useful for examining buckling induced by lower flange compression when the upper flange is restrained against lateral translation.
Substructuring Technique for Damage Detection Using Statistical Multi-Stage Artificial Neural Network
Authors: Bakhary Norhisham , Hao Hong , Deeks Andrew J.
Published: August 2010

Artificial Neural networks (ANN) have been proven in many studies to be able to efficiently detect damage from vibration measurements. Their capability to recognize patterns and to handle non-linear and non-unique problems provides an advantage over traditional mathematical methods in correlating the vibration data to damage location and severity. However, one shortcoming of ANN is they require enormous computational effort and sometimes prohibitive time and computer memory for training a reliable ANN model, especially when structures with many degrees of freedom are involved. Therefore, in most cases, rather large elements are used in the structure model to reduce the degrees of freedom. This results in the structural vibration properties not being sensitive to small damage in a large element. As a result, direct application of ANN to detecting damage in a large civil engineering structures is not feasible. In this study, a multi-stage ANN incorporating a probability method is proposed to tackle this problem. Through this method, a structure is divided into several substructures, and each substructure is assessed independently. In each subsequent stage, only the damaged substructures are analyzed, and eventually the location and severity of small structural damage can be detected. This approach greatly reduces the computational time and the required computer memory. Moreover, a probabilistic method is also used to include the uncertainties in vibration frequencies and mode shapes in damage detection analysis. It is found that this method reduces the uncertainty effect in frequencies due to duplication error in the multi-stage ANN model and reduces the uncertainty effect in mode shapes due to the damage in other substructures. The developed approach is applied to detect damage in numerically simulated and laboratory tested concrete slab. The results demonstrate that the proposed method can detect small damage with a higher level of confidence, and the undamaged elements are less likely to be falsely detected.
Solving the Lilley Equation with Quadrupole and Dipole Sources
Authors: Tester Brian J. , Morfey Christopher L.
Published: August 2010

The literature contains various methods for solving the Lilley equation with different types of quadrupole and dipole sources to represent the mixing noise radiated into the far-field by isothermal and heated jets. These include two basic numerical solution methods, the ‘direct’ and the ‘adjoint’, and a number of asymptotic, analytic solutions. The direct and adjoint equations are reviewed and it is shown that their solutions are not only related through the adjoint property: the radial ODE for the adjoint displacement Green's function is the same as that governing the direct displacement Green's function because this particular Green's function obeys classical reciprocity with respect to its radial dependence. Further, by comparing the two numerical solution methods within the context of the parallel flow assumption of the Lilley equation, it is shown that the numerical effort for the two methods is equivalent. The numerical solutions are compared with analytic low frequency ‘thin shear layer’ solutions and WKB solutions, both outside and inside the cone of silence. It is concluded that the former should be used with caution at all angles, while the WKB has some limitations inside the cone of silence. Although numerical solutions can be obtained with little computational effort and are the preferred route for jet mixing noise predictions, the analytic solutions still offer important physical insights as well as verification of numeric results.
Modelling of Sound Generation by Turbulent Reacting Flows
Authors: Bailly Christophe , Bogey Christophe , Candel Sébastien
Published: August 2010

The two components of combustion noise, namely the direct noise induced by heat release fluctuations in the flow and the indirect noise caused by acceleration of entropy perturbations through mean flow gradients resulting in acoustic radiation, are examined by considering different types of inhomogeneous wave equations deduced from the balance equations of fluid dynamics. This is accomplished by adapting acoustic analogies initially derived by Lighthill (1952), Phillips (1960) and Lilley (1972) for non-reactive flows to the reacting case. This reformulation is based on a standard set of assumptions borrowed from combustion. It is shown that a consistent formulation of a wave operator and its associated source terms is required.
Effects of Geometric Details on Slat Noise Generation and Propagation
Authors: Khorrami Mehdi R. , Lockard David P.
Published: August 2010

The relevance of geometric details to the generation and propagation of noise from leading-edge slats is considered. Typically, such details are omitted in computational simulations and model-scale experiments thereby creating ambiguities in comparisons with acoustic results from flight tests. The current study uses two-dimensional, computational simulations in conjunction with a Ffowcs Williams-Hawkings (FW-H) solver to investigate the effects of previously neglected slat “bulb” and “blade” seals on the local flow field and the associated acoustic radiation. The computations show that the presence of the “blade” seal at the cusp in the simulated geometry significantly changes the slat cove flow dynamics, reduces the amplitudes of the radiated sound, and to a lesser extent, alters the directivity beneath the airfoil. Furthermore, the computations suggest that a modest extension of the baseline “blade” seal further enhances the suppression of slat noise. As a side issue, the utility and equivalence of FW-H methodology for calculating far-field noise as opposed to a more direct approach is examined and demonstrated.
Reliability Measure Model for Assistive Care Loop Framework Using Wireless Sensor Networks
Authors: Balasubramanian Venki , Hoang Doan B.
Published: August 2010

Body area wireless sensor networks (BAWSNs) are time‐critical systems that rely on the collective data of a group of sensor nodes. Reliable data received at the sink is based on the collective data provided by all the source sensor nodes and not on individual data. Unlike conventional reliability, the definition of retransmission is inapplicable in a BAWSN and would only lead to an elapsed data arrival that is not acceptable for time‐critical application. Time‐driven applications require high data reliability to maintain detection and responses. Hence, the transmission reliability for the BAWSN should be based on the critical time. In this paper, we develop a theoretical model to measure a BAWSN′s transmission reliability, based on the critical time. The proposed model is evaluated through simulation and then compared with the experimental results conducted in our existing Active Care Loop Framework (ACLF). We further show the effect of the sink buffer in transmission reliability after a detailed study of various other co‐existing parameters.
Parameters for Modeling a High-Rise Steel Building Frame Subject to Fire
Authors: Quiel Spencer , Garlock Maria
Published: August 2010

This paper examines the level of detail and complexity that one needs to incorporate in a computational finite element (FE) model to predict the thermal and structural response of steel high-rise building frames to fire. Comparisons are made between these models in terms of accuracy and efficiency. Performance related to three parameters was examined: (1) the representation of the structural system as a 3-D full frame model versus a 2-D plane-frame model, both of which include the steel frame and the floor slab; (2) the representation of the slab in the 2-D plane frame model; and (3) the effects of modeling the temperature profile of each steel member cross-section as non-uniform (i.e. allowing a thermal gradient to develop) versus uniform. Results indicate that the 2-D plane frame model can be reasonably used in some cases to predict the performance of the perimeter column and floor beams framing into them in a fire-exposed high-rise moment-resisting frame (MRF) with a significant savings in analysis run time. The slab has little influence on the structural analysis of a 2-D plane frame; however, the slab influences the thermal profile through the depth of the beams, and these temperature changes will produce a non-negligible change when calculating the behavior of the frame and should be accounted for. Results also indicate that models whose members have uniform temperature can be used to obtain reasonable estimates of the interaction between connected beams and columns. However, thermal gradients produce significant changes in the deflection mechanics and plastic P-M limit state behavior exhibited by non-uniformly heated beam-columns that experience a severe decrease in capacity; therefore, it is recommended that thermal gradients be included in models that are used to predict deflections or plastic limit state behavior.
Damage Assessment of Reinforced Concrete Structural Elements Subjected to Blast Load
Authors: Huang X. , Ma G.W. , Li J.C.
Published: August 2010

An analytical approach of damage assessment for reinforced concrete structural elements subjected to blast loads is proposed. The nonlinear deformational behavior of the reinforced concrete structural element is considered and the pressure-impulse diagrams with respect to combined bending and shear failure are derived. The theoretical derivation is divided into elastic and post-elastic stages. A single degree of freedom system is adopted in the elastic stage to calculate the structural response due to shear and/or bending failure, respectively. The final displacement, velocity, and acceleration of the elastic stage are used as the initial conditions of the subsequent stages. In the post-elastic stages, the structural element is assumed to behave as a multi-linear model, and the softening property of the reinforced concrete is taken into account. The present method can be applied to various reinforced concrete structures with different elastic and post-elastic behaviors. The results are compared to show the effect of the different behavior of reinforced concrete.
Acceptable Risk Criteria for Infrastructure Protection
Authors: Stewart Mark G.
Published: August 2010

This paper reviews risk-based approaches to assessing the risk acceptability and cost-effectiveness of protective measures for infrastructure. The paper describes three risk acceptance criteria based on fatality risks, failure probabilities and net benefit assessment. These criteria can be applied to any item of infrastructure such as buildings, bridges, dams, offshore platforms, etc. and also applies to any man-made or natural hazard such as earthquakes, cyclones, terrorism, floods and so on. The decision support framework accompanying these risk acceptance criteria considers hazard and threat probabilities, value of human life, physical and indirect damages, risk reduction and protective measure costs. This has specific utility for the safety and economical design and assessment of new and existing protective structures against shock and impact loading. Risk assessments are conducted for a bridge over an inland waterway where the hazard is ship impact and a building subject to terrorist attack. The illustrative examples showed under what combination of risk reduction, and fatality and damage costs the fatality and failure risks would be acceptable, and when protective measures would be cost-effective.
A Unified Approach to Box-Mengerian Hypergraphs
Authors: Chen Xujin , Chen Zhibin , Zang Wenan
Published: August 2010

A hypergraph is called box-Mengerian if the linear system Ax ≥ 1, x ≥ 0 is box-totally dual integral (box-TDI), where A is the edge-vertex incidence matrix of the hypergraph. Because it is NP-hard in general to recognize box-Mengerian hypergraphs, a basic theme in combinatorial optimization is to identify such objects associated with various problems. In this paper, we show that the so-called equitably subpartitionable (ESP) property, first introduced by Ding and Zang (Ding, G., W. Zang. 2002. Packing cycles in graphs. J. Combin. Theory Ser. B 86 381–407) in their characterization of all graphs with the min-max relation on packing and covering cycles, turns out to be even sufficient for box-Mengerian hypergraphs. We also establish several new classes of box-Mengerian hypergraphs based on ESP property. This approach is of transparent combinatorial nature and is hence fairly easy to work with.
Does Diversity Climate Lead to Customer Satisfaction? It Depends on the Service Climate and Business Unit Demography
Authors: McKay Patrick F. , Avery Derek R. , Liao Hui , Morris Mark A.
Published: August 2010

Extending insights from Cox's interactional model of cultural diversity [Cox, T. H., Jr. 1994. Cultural Diversity in Organizations: Theory, Research and Practice. Berett-Koehler, San Francisco], we examine the influence of diversity climate on customer satisfaction, a key business-unit outcome. In addition, we explore service climate and minority and female representations as boundary conditions of the diversity climate–customer satisfaction relationship. Utilizing longitudinal data from 59,592 employees and 1.2 million customers of 769 store units of a large U.S. national retail organization, the results reveal that, as hypothesized, diversity climate is positively and significantly related to customer satisfaction measured a year later. Moreover, the diversity climate–customer satisfaction relationship is most strongly positive in predominately minority, highly pro-service store units, whereas female representation exhibits null moderating effects. These findings have important research and practical implications.