bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic force control with hydraulic actuators using added compliance and displacement compensation
Authors: Sivaselvan Mettupalayam V. , Reinhorn Andrei M. , Shao Xiaoyun , Weinreber Scot 
Published: July 2008

AbstractA new approach to dynamic force control of mechanical systems, applicable in particular to frame structures, over frequency ranges spanning their resonant frequencies is presented. This approach is implemented using added compliance and displacement compensation. Hydraulic actuators are inherently velocity sources, that is, an electrical signal regulates their velocity response. Such systems are therefore by nature high‐impedance (mechanically stiff) systems. In contrast, for force control, a force source is required. Such a system logically would have to be a low‐impedance (mechanically compliant) system. This is achieved by intentionally introducing a flexible mechanism between the actuator and the structure to be excited. In addition, in order to obtain force control over frequencies spanning the structure's resonant frequency, a displacement compensation feedback loop is needed. The actuator itself operates in closed‐loop displacement control. The theoretical motivation, as well as the laboratory implementation of the above approach is discussed along with experimental results. Having achieved a means of dynamic force control, it can be applied to various experimental seismic simulation techniques such as the effective force method and the real‐time dynamic hybrid testing method. Copyright © 2008 John Wiley & Sons, Ltd.
Application of the lattice Boltzmann method to flow in aneurysm with ring‐shaped stent obstacles
Authors: Xu X. , Lee J. S. 
Published: July 2008

AbstractTo resolve the characteristics of a highly complex flow, a lattice Boltzmann method with an extrapolation boundary technique was used in aneurysms with and without transverse objects on the upper wall, and results were compared with the non‐stented aneurysm. The extrapolation boundary concept allows the use of Cartesian grids even when the boundaries do not conform to Cartesian coordinates. To ease the code development and facilitate the incorporation of new physics, a new scientific programming strategy based on object‐oriented concepts was developed. The reduced flow, smaller vorticity magnitude and wall shear stress, and smaller du/dy near the dome of the aneurysm were observed when the proposed stent obstacles were used. The height of the stent obstacles was more effective to reduce the vorticity near the dome of the aneurysm than the width of the stent. The rectangular stent with 20% height‐of‐vessel radius was observed to be optimal and decreased the magnitude of the vorticity by 21% near the dome of the aneurysm. Copyright © 2008 John Wiley & Sons, Ltd.
Combined haplotype relative risk (CHRR): a general and simple genetic association test that combines trios and unrelated case‐controls
Authors: Guo Chao‐Yu , Lunetta Kathryn L. , DeStefano, Anita L. , Cupples L. Adrienne 
Published: July 2008

AbstractIn some genetic association studies, samples contain both parental and unrelated controls. Under such scenarios, instead of analyzing only trios using family‐based association tests or only unrelated subjects using a case‐control study design, Nagelkerke et al. ([2004] Eur. J. Hum. Genet. 12:964–970) and Epstein et al. ([2005] Am. J. Hum. Genet. 76:592–608) proposed methods that implemented a likelihood ratio test to combine the two different types of data. In this article, we put forward a more powerful and simplified strategy to combine trios with unrelated subjects based on the haplotype relative risk (HRR) (Falk and Rubinstein [1987] Ann. Hum. Genet. 51:227–233). The HRR compares parental marker alleles transmitted to an affected offspring to those not transmitted as a test for association, a strategy that is similar to a case‐control study that compares allele frequencies in diseased cases to those of unrelated controls. We prove that affected offspring can be pooled with diseased cases and that parental controls can be treated as unrelated controls when the trios and unrelated subjects are randomly sampled from the same population. Therefore, unrelated subjects can be incorporated into the HRR intuitively and effortlessly. For trios without complete parental genotypes, we adopted the strategy proposed by (Guo et al. [2005a] BMC Genet. 6:S90; [2005b] Hum. Hered. 59: 125–135), which is more feasible than the one proposed by Weinberg ([1999] Am. J. Hum. Genet. 64:1186–1193). In addition, simulation results suggest that the combined haplotype relative risk is more powerful than Epstein et al.'s method regardless of the disease prevalence in a homogeneous population. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Obtaining the steady‐state drawdown solutions of constant‐head and constant‐flux tests
Authors: Wang Chih‐Tse , Yeh Hund‐Der 
Published: July 2008

AbstractThe solutions of constant‐head and constant‐flux tests are commonly used to predict the temporal or spatial drawdown distribution or to determine aquifer parameters. Theis and Thiem equations, for instance, are well‐known transient and steady‐state drawdown solutions, respectively, of the constant‐flux test. It is known that the Theis equation is not applicable to the case where the aquifer has a finite boundary or the pumping time tends to infinity. On the other hand, the Thiem equation does not apply to the case where the aquifer boundary is infinite. However, the issue of obtaining the Thiem equation from the transient drawdown solution has not previously been addressed. In this paper, the drawdown solutions for constant‐head and constant‐flux tests conducted in finite or infinite confined aquifers with or without consideration of the effect of the well radius are examined comprehensively. Mathematical verification and physical interpretation of the solutions to these two tests converging or not converging to the Thiem equation are presented. The result shows that there are some finite‐domain solutions for these two tests that can converge to the Thiem equation when the time becomes infinitely large. In addition, the time criteria to give a good approximation to the finite‐domain solution by the infinite‐domain solution and the Thiem equation are investigated and presented. Copyright © 2008 John Wiley & Sons, Ltd.
Mercury transport in response to storm events from a northern forest landscape
Authors: Bushey Joseph T. , Driscoll Charles T. , Mitchell Myron J. , Selvendiran Pranesh , Montesdeoca Mario R. 
Published: July 2008

AbstractConcentrations and fluxes of mercury (Hg) species in surface waters of forested watersheds are affected by hydrological events. The mechanisms of Hg transport during these events are poorly understood and yet may influence Hg bioavailability and exposure to aquatic biota. Three storm events with varying magnitude and intensity were investigated (June, September and November 2005) at a forested watershed in the Adirondack region of New York State, USA. Concentrations of Hg species increased during these events, both above and downstream of wetlands in the watershed. While Hg flux was higher from wetland drainage, the Hg flux from the upland site exhibited a greater relative increase to elevated runoff. Hg flux was controlled by discharge; however, Hg species concentrations were not well correlated with discharge, dissolved organic carbon (DOC), or total suspended solids (TSS) through the duration of events. A counter‐clockwise hysteresis response of DOC with increasing runoff contrasted with the clockwise response for total Hg, suggesting different contributions from source areas for these solutes. Correspondence with elevated total K and NO3− (α < 0·05) during the rising limb of the hydrograph suggests rapid delivery of throughfall Hg, potentially enhanced by hillslope hollows, to the stream channel. As the watershed saturated, stream Hg appears to be derived from the soil Hg pool. Results suggest that particulate Hg did not contribute substantially to total Hg flux during events (<25%). These results emphasize the role of watershed attributes and storm characteristics in Hg transport and bioavailability. Copyright © 2008 John Wiley & Sons, Ltd.
Field and regional scale evaluation of irrigation efficiency in paddy fields case study: Guilan, Iran
Authors: Parsinejad Masoud , Yazdani Mohammad Reza , Ebrahimian Hamed 
Published: July 2008

AbstractLimitations on available water have caused increased attention toward research on techniques to use water more efficiently. In this study, the actual water application efficiency of rice paddy fields for 13 different sites throughout the province of Guilan, Iran, was investigated. Based on field measurements of water inflow and outflow, deep percolation and calculation of evapotranspiration, water application efficiency was determined for cases where the outflow was considered as a loss, i.e. at field scale, and for cases where a percentage of the outflow was considered as recoverable water, i.e. regional scale. The results show that, at field scale, the application water efficiency for the western, central and eastern section of the Sefidrood Irrigation Network was 38, 41 and 34%, respectively. On the other hand, at regional scale, if 80% of the outflow were considered as recoverable water, the above values were found to be 52, 51 and 46%, respectively. More recent proposed definitions on water management, such as consumed fraction (CF) and recoverable fraction (RF = 1 − CF) are also evaluated. Calculation of CF and RF values indicate that water potentially available for reuse is about 60% for the entire network. Copyright © 2008 John Wiley & Sons, Ltd.
Insights into functional modulation of catalytic RNA activity
Authors: Vourekas Anastassios , Stamatopoulou Vassiliki , Toumpeki Chrisavgi , Tsitlaidou Marianthi , Drainas Denis 
Published: July 2008

AbstractRNA molecules play critical roles in cell biology, and novel findings continuously broaden their functional repertoires. Apart from their well‐documented participation in protein synthesis, it is now apparent that several noncoding RNAs (i.e., micro‐RNAs and riboswitches) also participate in the regulation of gene expression. The discovery of catalytic RNAs had profound implications on our views concerning the evolution of life on our planet at a molecular level. A characteristic attribute of RNA, probably traced back to its ancestral origin, is the ability to interact with and be modulated by several ions and molecules of different sizes. The inhibition of ribosome activity by antibiotics has been extensively used as a therapeutical approach, while activation and substrate‐specificity alteration have the potential to enhance the versatility of ribozyme‐based tools in translational research. In this review, we will describe some representative examples of such modulators to illustrate the potential of catalytic RNAs as tools and targets in research and clinical approaches. © 2008 IUBMB IUBMB Life, 60(10): 669–683, 2008.
DNA damage in workers occupationally exposed to pesticide mixtures
Authors: Simoniello M. F. , Kleinsorge E. C. , Scagnetti J. A. , Grigolato R. A. , Poletta G. L. , Carballo M. A. 
Published: July 2008

AbstractPesticides are used in agriculture to protect crops but represent at the same time a potential risk to farmers and environment. The aim of this work is the evaluation of 54 subjects occupationally exposed to pesticides and 30 subjects as a control group using the quantification of DNA damage level by means of the alkaline Comet assay and the evaluation of repair processes. Damage index Comet assay (DICA) and damage index repair assay (DIRA) were studied in 27 pesticide applicator workers, 27 non‐pesticide applicators and controls. Our results show that both exposed groups revealed significant increase in DICA when compared with controls (P < 0.0001), as well as in DIRA (P < 0.0001). However, the spraying group exhibited a marginally significant difference in DICA (P = 0.05) when years of exposure are considered and a significant difference (P < 0.05) when the personal protective equipment used by individuals was taken as a comparison factor. The influence of confounding factors on the genotoxic effects of occupational exposure to pesticides was investigated and no significant differences were observed considering age, gender, smoking and alcohol consumption in relation to DICA and DIRA. Since DNA damage is an important step in events leading from carcinogen exposure to cancer disease, our study highlights the potential health risk associated with agrochemical exposure in developing countries with vast cultivated areas, such as Argentina. Copyright © 2008 John Wiley & Sons, Ltd.
In vitro evaluation of the chemoprotective action mechanisms of leontopodic acid against aflatoxin B1 and deoxynivalenol‐induced cell damage
Authors: Costa Stefano , Schwaiger Stefan , Cervellati Rinaldo , Stuppner Hermann , Speroni Ester , Guerra Maria Clelia 
Published: July 2008

AbstractSeveral in vitro studies showed that free radical scavengers possess chemopreventive properties against mycotoxin‐induced cell damage which are at least partially associated with the induction of phase II detoxifying enzymes and antioxidant enzymes like glutathione S‐transferase (GST) and glutathione peroxidase (GPx). The aim of this project was to study the chemopreventive effects of leontopodic acid (LA), a potent natural occurring free radical scavenger isolated from the aerial parts of Leontopodium alpinum. Different mycotoxins were evaluated in two different cell lines on the basis of their specific toxicity: aflatoxin B1 (AFB1) on HepG2 cells and deoxynivalenol (DON) on U937 cells. Cell viability and reactive oxygen species concentration were determined, and the effects of pre‐treatment with LA on these parameters were investigated together with the GST and GPx activity as well as the concentration of reduced glutathione. The results show that LA protects U937 cells from DON‐induced cell damage but not HepG2 cells from AFB1. Moreover LA is able to enhance GPx activity in U937, but not GST activity in HepG2. We hypothesize that the increase in detoxifying enzymes is probably the main mechanism of antioxidant mediated chemoprevention. Copyright © 2008 John Wiley & Sons, Ltd.
Annexin II/Annexin II receptor axis regulates adhesion, migration, homing, and growth of prostate cancer
Authors: Shiozawa Yusuke , Havens Aaron M. , Jung Younghun , Ziegler Anne M. , Pedersen Elisabeth A. , Wang Jingcheng , Wang Jianhua , Lu Ganwei , Roodman G. David , Loberg Robert D. , Pienta Kenneth J. , Taichman Russell S. 
Published: July 2008

AbstractOne of the most life‐threatening complications of prostate cancer is skeletal metastasis. In order to develop treatment for metastasis, it is important to understand its molecular mechanisms. Our work in this field has drawn parallels between hematopoietic stem cell and prostate cancer homing to the marrow. Our recent work demonstrated that annexin II expressed by osteoblasts and endothelial cells plays a critical role in niche selection. In this study, we demonstrate that annexin II and its receptor play a crucial role in establishing metastasis of prostate cancer. Prostate cancer cell lines migrate toward annexin II and the adhesion of prostate cancer to osteoblasts and endothelial cells was inhibited by annexin II. By blocking annexin II or its receptor in animal models, short‐term and long‐term localization of prostate cancers are limited. Annexin II may also facilitate the growth of prostate cancer in vitro and in vivo by the MAPK pathway. These data strongly suggest that annexin II and its receptor axis plays a central role in prostate cancer metastasis, and that prostate cancer utilize the hematopoietic stem cell homing mechanisms to gain access to the niche. J. Cell. Biochem. 105: 370–380, 2008. © 2008 Wiley‐Liss, Inc.
Regulation of Wnt/β‐catenin pathway by cPLA2α and PPARδ
Authors: Han Chang , Lim Kyu , Xu Lihong , Li Guiying , Wu Tong 
Published: July 2008

AbstractCytosolic phospholipase A2α (cPLA2α) is a rate‐limiting key enzyme that releases arachidonic acid (AA) from membrane phospholipid for the production of biologically active lipid mediators including prostaglandins, leukotrienes and platelet‐activating factor. cPLA2α is translocated to nuclear envelope in response to intracellular calcium increase and the enzyme is also present inside the cell nucleus; however, the biological function of cPLA2α in the nucleus remains unknown. Here we show a novel role of cPLA2α for activation of peroxisome proliferator‐activated receptor‐δ (PPARδ) and β‐catenin in the nuclei. Overexpression of cPLA2α in human cholangiocarcinoma cells induced the binding of PPARδ to β‐catenin and increased their association with the TCF/LEF response element. These effects are inhibited by the cPLA2α siRNA and inhibitors as well as by siRNA knockdown of PPARδ. Overexpression of PPARδ or treatment with the selective PPARδ ligand, GW501516, also increased β‐catenin binding to TCF/LEF response element and increased its reporter activity. Addition of AA and GW501516 to nuclear extracts induced a comparable degree of β‐catenin binding to TCF/LEF response element. Furthermore, cPLA2α protein is present in the PPARδ and β‐catenin binding complex. Thus the close proximity between cPLA2α and PPARδ provides a unique advantage for their efficient functional coupling in the nucleus, where AA produced by cPLA2α becomes immediately available for PPARδ binding and subsequent β‐catenin activation. These results depict a novel interaction linking cPLA2α, PPARδ and Wnt/β‐catenin signaling pathways and provide insight for further understanding the roles of these key molecules in human cells and diseases. J. Cell. Biochem. 105: 534–545, 2008. © 2008 Wiley‐Liss, Inc.
Relationship between the methylation status of dietary flavonoids and their growth‐inhibitory and apoptosis‐inducing activities in human cancer cells
Authors: Landis‐Piwowar Kristin R. , Milacic Vesna , Dou Q. Ping 
Published: July 2008

AbstractFlavonoids are polyphenolic compounds widely distributed in the plant kingdom. Compelling research indicates that flavonoids have important roles in cancer chemoprevention and chemotherapy possibly due to biological activities that include action through anti‐inflammation, free radical scavenging, modulation of survival/proliferation pathways, and inhibition of the ubiquitin–proteasome pathway. Plant polyphenols including the green tea polyphenol (‐)‐epigallocatechin gallate or (‐)‐EGCG, and the flavonoids apigenin, luteolin, quercetin, and chrysin have been shown to inhibit proteasome activity and induce apoptosis in human leukemia cells. However, biotransformation reactions to the reactive hydroxyl groups on polyphenols could reduce their biological activities. Although methylated polyphenols have been suggested to be metabolically more stable than unmethylated polyphenols, the practical use of methylated polyphenols as cancer preventative agents warrants further investigation. In the current study, methylated and unmethylated flavonoids were studied for their proteasome‐inhibitory and apoptosis‐inducing abilities in human leukemia HL60 cells. Methylated flavonoids displayed sustained bioavailability and inhibited cellular proliferation by arresting cells in the G1 phase. However, they did not act as proteasome inhibitors in either an in vitro system or an in silico model and only weakly induced apoptosis. In contrast, unmethylated flavonoids exhibited inhibition of the proteasomal activity in intact HL60 cells, accumulating proteasome target proteins and inducing caspase activation and poly(ADP‐ribose) polymerase cleavage. We conclude that methylated flavonoids lack potent cytotoxicity against human leukemia cells and most likely have limited ability as chemopreventive agents. J. Cell. Biochem. 105: 514–523, 2008. © 2008 Wiley‐Liss, Inc.
Expression of Runx2 transcription factor in non‐skeletal tissues, sperm and brain
Authors: Jeong Jae‐Hwan , Jin Jung‐Sook , Kim Hyun‐Nam , Kang Sang‐Min , Liu Julie C. , Lengner Christopher J. , Otto Florian , Mundlos Stefan , Stein Janet L. , van Wijnen Andre J. , Lian Jane B. , Stein Gary S. , Choi Je‐Yong 
Published: July 2008

AbstractRunx2 is a master transcription factor for chondrocyte and osteoblast differentiation and bone formation. However expression of Runx2 (by RT‐PCR), has been reported in non‐skeletal tissues such as breast, T cells and testis. To better define Runx2 activity in non‐skeletal tissues, we examined transgenic (Tg) mice expressing LacZ gene under control of 3.0 kb (3 kb Tg) or 1.0 kb (1 kb Tg) of the Runx2 distal (P1) promoter, Runx2 LacZ knock‐in (Runx2+/LacZ) and Runx2/P1 LacZ knock‐in (Runx2/P1+/LacZ). In the Runx2 3 kb Tg mouse, β‐galactosidase (β‐gal) expression appeared in various non‐skeletal tissues including testis, skin, adrenal gland and brain. β‐gal expression from both 3 kb and 1 kb Tg, reflecting activity of the Runx2 promoter, was readily detectable in seminiferous tubules of the testis and the epididymis. At the single cell level, β‐gal was detected in spermatids and mature sperms not in sertoli or Leydig cells. We also detected a positive signal from the Runx2+/LacZ and Runx2/P1+/LacZ mice. Indeed, Runx2 expression was observed in isolated mature sperms, which was confirmed by RT‐PCR and Western blot analysis. Runx2, however, was not related to sex determination and sperm motility. Runx2 mediated β‐gal activity is also found robustly in the hippocampus and frontal lobe of the brain in Runx2+/LacZ. Collectively, these results indicate that Runx2 is expressed in several non‐skeletal tissues particularly sperms of testis and hippocampus of brain. It suggests that Runx2 may play an important role in male reproductive organ testis and brain. J. Cell. Physiol. 217: 511–517, 2008. © 2008 Wiley‐Liss, Inc.
Histological and ultrastructural investigation of early gonad development and sex differentiation in Adriatic sturgeon (Acipenser naccarii, Acipenseriformes, Chondrostei)
Authors: Grandi Gilberto , Chicca Milvia 
Published: July 2008

AbstractGonad development and sex differentiation from embryos to 594‐day‐old individuals were investigated in farmed Acipenser naccarii using light and transmission electron microscopy. The migrating primordial germ cells first appear along the dorsal wall of the body cavity in embryos 1.5 days before hatching. The gonadal ridge, containing a few primary primordial germ cells (PGC‐1) surrounded by enveloping cells, appears in 16‐day‐old larvae. At 60 days, the undifferentiated gonad is lamellar and PGC‐1 multiply, producing PGC‐2. In 105‐day‐old juveniles, a distinct germinal area with advanced PGC‐2 appears on the lateral side near the mesogonium and the first blood vessels are visible. At 180 days, putative ovaries with a notched gonadal epithelium and putative testes with a smooth one appear, together with adipose tissue on the distal side. In 210‐day‐old juveniles, active proliferation of germ cells begins in the putative ovaries, whereas putative testes still contain only a few germ cells. The onset of meiosis and reorganization of stromal tissue occurs in ovaries of 292‐day‐old individuals. Ovaries with developed lamellae enclosing early oocyte clusters and follicles with perinucleolar oocytes occur at 594 days. Meiotic stages are never found, even in anastomozing tubular testes of 594‐day‐old individuals. Steroid producing cells are detected in the undifferentiated gonad and in the differentiated ones of both sexes. Anatomical differentiation of the gonad precedes cytological differentiation and female differentiation largely precedes that of the male. Gonad development and differentiation are also associated with structural changes of connective tissue, viz. collagen‐rich areas are massive in developing testes and reduced in ovaries. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.