bluuebunny/crossref_metadata_2025 huggingface dataset:
Geomorphology, hydrology, and aquatic vegetation drive seasonal hyporheic flow patterns across a gravel‐dominated floodplain
Authors: Jones Krista L. , Poole Geoffrey C. , Woessner William W. , Vitale Matt V. , Boer Brian R. , O'Daniel Scott J. , Thomas Steven A. , Geffen Brook A.
Published: November 2007

Across 1·7 km2 of the Umatilla River floodplain (Oregon, USA), we investigated the influences of an ephemeral tributary and perennial ‘spring channel’ (fed only by upwelling groundwater) on hyporheic hydrology. We derived maps of winter and summer water‐table elevations from data collected at 46 monitoring wells and 19 stage gauges and used resulting maps to infer groundwater flow direction. Groundwater flow direction varied seasonally across the floodplain and was influenced by main channel stage, flooding, the tributary creek, and the location and direction of hyporheic exchange in the spring channel. Hyporheic exchange in the spring channel was evaluated with a geochemical mixing model, which confirmed patterns of floodplain groundwater movement inferred from water‐table maps and showed that the spring channel was fed predominantly by hyporheic water from the floodplain aquifer (87% during winter, 80% during summer), with its remaining flow supplied by upslope groundwater from the adjacent catchment aquifer. Summertime growth of aquatic macrophytes in the spring channel also influenced patterns of hyporheic exchange and groundwater flow direction in the alluvial aquifer by increasing flow resistance in the spring channel, locally raising surface water stage and adjacent water‐table elevation, and thereby altering the slope of the water‐table in the hyporheic zone. The Umatilla River floodplain is larger than most sites where hyporheic hydrology has been investigated in detail. Yet, our results corroborate other research that has identified off‐channel geomorphic features as important drivers of hyporheic hydrology, including previously published modeling efforts from a similar river and field observations from smaller streams. Copyright © 2007 John Wiley & Sons, Ltd.
TOPCAT‐NP: a minimum information requirement model for simulation of flow and nutrient transport from agricultural systems
Authors: Quinn P. F. , Hewett C. J. M. , Dayawansa N. D. K.
Published: November 2007

Future catchment planning requires a good understanding of the impacts of land use and management, especially with regard to nutrient pollution. A range of readily usable tools, including models, can play a critical role in underpinning robust decision‐making. Modelling tools must articulate our process understanding, make links to a range of catchment characteristics and scales and have the capability to reflect future land‐use management changes. Hence, the model application can play an important part in giving confidence to policy makers that positive outcomes will arise from any proposed land‐use changes. Here, a minimum information requirement (MIR) modelling approach is presented that creates simple, parsimonious models based on more complex physically based models, which makes the model more appropriate to catchment‐scale applications. This paper shows three separate MIR models that represent flow, nitrate losses and phosphorus losses. These models are integrated into a single catchment model (TOPCAT‐NP), which has the advantage that certain model components (such as soil type and flow paths) are shared by all three MIR models. The integrated model can simulate a number of land‐use activities that relate to typical land‐use management practices. The modelling process also gives insight into the seasonal and event nature of nutrient losses exhibited at a range of catchment scales. Three case studies are presented to reflect the range of applicability of the model. The three studies show how different runoff and nutrient loss regimes in different soil/geological and global locations can be simulated using the same model. The first case study models intense agricultural land uses in Denmark (Gjern, 114 km2), the second is an intense agricultural area dominated by high superphosphate applications in Australia (Ellen Brook, 66 km2) and the third is a small research‐scale catchment in the UK (Bollington Hall, 2 km2). Copyright © 2007 John Wiley & Sons, Ltd.
Reactive oxygen species‐dependent destruction of MEK and Akt in Manumycin stimulated death of lymphoid tumor and myeloma cell lines
Authors: Sears Khandra T. , Daino Hanako , Carey Gregory B.
Published: November 2007

Manumycin‐A (Man‐A) is a farnesyltransferase inhibitor (FTI), which was originally identified as an effective tumoricide against several cancers, especially ones harboring constitutively active Ras. However, it is becoming apparent that Man‐A can stimulate tumor death independently of FTases. Antioxidant treatment blocked Man‐A‐stimulated DNA damage and reversed Man‐A‐inhibited tumor growth. However, the precise molecular details of how these reactive oxygen species (ROS) influence cell signaling modules are poorly understood. We examined how ROS may modulate death and survival pathways in a panel of tumor cells. Man‐A treatment resulted in a massive induction of superoxide anion (·O2−) only in Man‐A‐sensitive tumors. Within 1 hr, Man‐A caused the ROS‐dependent activation of caspases 9 and 3. In this time‐frame, the Ras‐Raf target, MEK, and the survival protein Akt were dephosphorylated in ROS‐dependent fashions and then cleaved in ROS and caspase‐dependent manners. Pretreatment with ROS scavengers blocked the adverse effects of Man‐A, including the processing of caspases and the cleavage of MEK and Akt. These events were noted before any losses in Ras activity or changes in its maturation could be detected. Finally, transfection with cDNAs encoding the antioxidant enzymes catalase, superoxide dismutase and thioredoxin reductase inhibited superoxide induction and apoptosis. Together, our data suggest that the elimination of tumors by Man‐A can be independent of the inhibiting of Ras. However, one universal feature observed is the generation of death‐triggering intracellular oxidants that appear to directly participate in the select targeting of growth and survival proteins that then either augment or ensure tumor cell death. © 2007 Wiley‐Liss, Inc.
Trends in childhood acute lymphoblastic leukemia in Western Australia, 1960–2006
Authors: Milne Elizabeth , Laurvick Crystal L , de Klerk Nicholas , Robertson Laila , Thompson Judith R. , Bower Carol
Published: November 2007

Increases in the incidence of childhood acute lymphoblastic leukemia (ALL) have been reported in some countries, while other reports from similar geographical regions have indicated stable rates. The reasons for the discrepancies have been debated in the literature, with the focus on whether the observed increases are “real” or an artifact resulting from improvements in diagnosis, case ascertainment and population coverage over time. We used population‐based data from Western Australia to investigate trends in the incidence of childhood ALL between 1960 and 2006. Age‐standardized incidence rates (ASRs) and rate ratios (indicating annual percent change) were estimated using Poisson regression. Between 1960 and 2006, the ASR was 3.7 per 100,000 person‐years, with an annual percent increase of 0.40% (95% CI: −0.20, 1.00). Between 1982 and 2006, the ASR was 3.8, with an annual percent increase of 0.80% (95% CI = −0.70 to 2.30). This increased to 1.42% (95% CI: −0.30, 3.0) when a sensitivity analysis was undertaken to assess the effect of excluding the final 2 years of data. Annual increases of 3.7% (95% CI: −0.50, 8.00) among children aged 5–14 years, and of 3.10% (95% CI: 0.50, 5.70) in girls, were observed for this latter period. These results were supported by national Australian incidence data available for 1982–2003. There may have been a small increase in the incidence of ALL since 1982 among girls and older children, but an overall increase appears unlikely. No impact of folate supplementation or fortification is apparent. © 2007 Wiley‐Liss, Inc.
Bayesian counterfactual analysis of the sources of the great moderation
Authors: Kim Chang‐Jin , Morley James , Piger Jeremy
Published: November 2007

We use counterfactual experiments to investigate the sources of the large volatility reduction in US real GDP growth in the 1980s. Contrary to an existing literature that conducts counterfactual experiments based on classical estimation and point estimates, we consider Bayesian analysis that provides a straightforward measure of estimation uncertainty for the counterfactual quantity of interest. Using Blanchard and Quah's (1989) structural VAR model of output growth and the unemployment rate, we find strong statistical support for the idea that a counterfactual change in the size of structural shocks alone, with no corresponding change in the propagation of these shocks, would have produced the same overall volatility reduction as what actually occurred. Looking deeper, we find evidence that a counterfactual change in the size of aggregate supply shocks alone would have generated a larger volatility reduction than a counterfactual change in the size of aggregate demand shocks alone. We show that these results are consistent with a standard monetary VAR, for which counterfactual analysis also suggests the importance of shocks in generating the volatility reduction, but with the counterfactual change in monetary shocks alone generating a small reduction in volatility. Copyright © 2007 John Wiley & Sons, Ltd.
In vitro evaluation of electrospun nanofiber scaffolds for vascular graft application
Authors: Lee Sang Jin , Yoo James J. , Lim Grace J. , Atala Anthony , Stitzel Joel
Published: November 2007

Blood vessels are diverse in size, mechanical and biochemical properties, cellular content, and ultrastructural organization depending on their location and specific function. Therefore, it is required to control the fabrication of vascular grafts for obtaining desirable characteristics of blood vessel substitutes. In this study we have fabricated various scaffolds using the electrospinning technique with blends of collagen, elastin, and several biodegradable polymers. Biocompatibility, dimensional stability in vitro and mechanical properties were evaluated. Materials were blended at a relative concentration by weight of 45% collagen, 15% elastin, and 40% synthetic polymer to mimic the ratio of collagen and elastin in native blood vessels. The fabricated scaffolds are composed of randomly oriented fibers with diameters ranging from 477 to 765 nm. The electrospun scaffolds are nontoxic, dimensionally stable in an in vitro culture environment, easily fabricated, and possess controlled mechanical properties that simulate the ultrastructure of native blood vessels. The present study suggests that the introduction of synthetic biodegradable polymers enabled tailoring of mechanical properties of vascular substitutes and improving compliance matching for vascular tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Callus formation and remodeling at titanium implants
Authors: Eriksson Cecilia , Ohlson Karin , Richter Katrin , Billerdahl Nicklas , Johansson Mattias , Nygren Håkan
Published: November 2007

Titanium is biocompatible with bone tissue, and during the healing process bone makes intimate contact with the implant surface. Although much is known about the long‐term healing of implants, less is known about the callus formation at implants. In this study, the histology of bone healing was studied during the period between 4 and 14 days. Incisions were made in rat tibia. Some incisions were simply left to heal, while in others titanium discs were implanted. Smooth implants as well as implants with different porosities were used. After 4, 7, and 14 days of healing, the sites of bone incisions were retrieved, decalcified, sectioned, and stained. The aim was to compare normal fracture healing with implant healing and to see whether implant properties influenced the short‐term healing process. Similarities between fracture healing and implant healing were evident. In both cases, inflammation, soft and hard callus formation, and remodeling had taken place during the period investigated. Between 7 and 14 days substantial bone resorption occurred around the implants. While after 14 days the marrow was almost completely reconstituted during normal wound healing, at the implants a thin layer of bone remained in close contact with the surface. Results from bone–implant contact measurements indicate that the surface properties of the implants do not have a significant influence on the early bone formation, since there were no significant differences between the smooth surface and any of the porous surfaces. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Effect of 2‐methacryloyloxyethyl phosphorylcholine concentration on photo‐induced graft polymerization of polyethylene in reducing the wear of orthopaedic bearing surface
Authors: Kyomoto Masayuki , Moro Toru , Miyaji Fumiaki , Hashimoto Masami , Kawaguchi Hiroshi , Takatori Yoshio , Nakamura Kozo , Ishihara Kazuhiko
Published: November 2007

Photo‐induced graft polymerization of 2‐methacryloyloxyethyl phosphorylcholine (MPC) on cross‐linked polyethylene (CLPE) has been developed as a novel technology for reducing wear of orthopaedic bearings. In this study, the effect of MPC concentration on graft polymerization and the resultant properties of the grafted poly (MPC) layer have been investigated. The grafted poly (MPC) layer thickness increased with the MPC concentration in feed. The hip simulator wear test confirmed that CLPE‐g‐MPC cups exhibited minimal wear compared with untreated CLPE cups. Since MPC is a highly hydrophilic methacrylate, the water‐wettability of CLPE‐g‐MPC was greater than that of untreated CLPE due to the formation of a poly(MPC) nanometer‐scale layer. The CLPE‐g‐MPC orthopaedic bearing surface exhibited high lubricity, because of the present of the poly(MPC) layer even at a thickness of 10 nm. This layer is considered responsible for the improved wear resistance. Nanometer‐scale modification of CLPE with poly(MPC) is expected to significantly increase the durability of the orthopaedic bearings. Poly (MPC) layer thickness can be controlled by changing the MPC concentration in feed. In order to achieve nanometer‐scale modification of poly(MPC) in this manner, it is necessary to use a long photo‐irradiation time for the MPC graft polymerization system, which contains a high‐concentration monomer without its gelation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Double hydrophilic block copolymers PEO‐b‐PGA: Synthesis, application as potential drug carrier and drug release via pH‐sensitive linkage
Authors: Tang Xuezhi , Pan Cai‐Yuan
Published: November 2007

A new type of double hydrophilic block copolymer, poly(ethylene oxide) (PEO)‐block‐poly(glycerol monoacrylate) (PGA) have been synthesized via atom transfer radical polymerization of solketal acrylate (SA) using PEO‐Br as macro‐initiator, and subsequent hydrolysis of the acetal‐protecting group in 1N HCl solution in THF. The polymerization is of a “living” nature and the copolymers with controlled molecular weight and narrow polydispersity (Mw/Mn = 1.01–1.03) were obtained. The complete hydrolysis of the acetal‐protecting group was verified by IR and NMR spectroscopies. A hydrophobic fluorescent compound, 1‐pyrenecarboxaldehyde, was used as a model drug, which was covalently bound to the PEO‐b‐PGA block copolymer via a pH‐sensitive acetal linkage. The kinetics of the pyrene release was studied in THF/aqueous buffers at pH 5.0 (close to pH in endosomes) and 7.4 (pH of blood plasma) by fluorescent spectroscopy. The pyrene was released much faster at pH 5.0 than that at pH 7.4. The micelle behavior in solutions at pH 5.0 and 7.4 was studied by dynamic light scattering. All results show that this double hydrophilic PEO‐b‐PGA is a promising candidate for potential application as drug carrier for those carbonyl‐containing hydrophobic drugs. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Regulation of vascular smooth muscle cells on poly(ethylene terephthalate) film by O‐carboxymethylchitosan surface immobilization
Authors: Zhu Ai‐Ping , Zhao Feng , Fang Ning
Published: November 2007

Specifying the chemical environment of cells is a well‐established method of controlling cellular behaviors. In this study, poly(ethylene terephthalate) (PET) film was selected as a typical biomaterial to detect the effects of chemical modifications on material surface in controlling cell behaviors. Natural biopolymer chitosan and its biocompatible derivative, O‐carboxymethylchitosan (OCMCS) were surface immobilized on PET, respectively, via argon plasma followed by graft copolymerization with acrylic acid (AAc), which was exploited to covalently couple PET with chitosan (CS) and OCMCS molecules. Smooth muscle cells (SMCs) displayed a surface‐dependent cell spreading and cytoskeletal organization. The cells spread with a more pronounced elongated spindle shape, smaller cell area, and lower cell shape index (CSI) on OCMCS‐modified PET surface than on PET, or the PAA and chitosan‐immobilized PET surfaces after 24 h of culture. Cell‐culture viability after 5 days showed that all the modified materials possessed good cell proliferation. Our results suggest that cell adhesion, morphology, and growth can be mediated not only by varying the functional groups, electric charge, and wettability of PET surface but also by the specific biological recognition elicited from the biomaterials. These findings strongly support the concept that the microenvironment significantly influences cell behavior, highlighting the importance of environmental material biochemistry in cell‐based tissue engineering schemes. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Comparative study of nanohydroxyapatite microspheres for medical applications
Authors: Mateus Alis Yovana Pataquiva , Barrias Cristina C. , Ribeiro Cristina , Ferraz Maria P. , Monteiro Fernando J.
Published: November 2007

This study concerns the preparation, physical, and in vitro characterization of two different types of hydroxyapatite (HA) microspheres, which are intended to be used as drug‐delivery systems and bone‐regeneration matrices. Hydroxyapatite nanoparticles (HA‐1 and HA‐2) were prepared using the chemical precipitation synthesis with H3PO4, Ca(OH)2, and a surfactant, SDS (sodium dodecyl sulfate), as starting reagents. The HA powders were dispersed in a sodium alginate solution, and spherical particles were obtained by droplet extrusion coupled with ionotropic gelation in the presence of Ca2+. These were subsequently sintered to produce HA‐1 and HA‐2 microspheres with a uniform size and interconnected microporosity. Both powders and microspheres were characterized using FTIR and X‐ray diffraction. Moreover, SEM and mercury intrusion porosimetry were used to analyze the microspheres, and TEM was used to analyze the powders. Results showed that pure HA and mixtures of HA/β‐TCP in the nanometer range and needlelike shape were obtained for HA‐1 and HA‐2 powders, respectively. Neutral Red, scanning electron microscopy and confocal microscopy were used to evaluate the behavior of osteoblastic‐like MG‐63 cells cultured on HA microspheres surfaces for 7 days. Results showed that good adhesion and proliferation of osteoblasts on the HA microspheres surface. Cells built bridges between adjacent microspheres, forming microspheres‐cells clusters in both types of materials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Preparation of water‐insoluble albumin film possessing nonadherent surface for cells and ligand binding ability
Authors: Yamazoe Hironori , Tanabe Toshizumi
Published: November 2007

Serum albumin is the most abundant protein in blood plasma. Albumin has the ability to bind to a wide variety of compounds including drugs, and cells as well as proteins do not attach to an albumin‐coated surface. These properties of albumin are attractive for biomaterials utilized in biomedical fields. In the present study, we aimed to prepare a water‐insoluble albumin film possessing suitable flexibility and native albumin characteristics, such as drug binding ability and resistance to cell adhesion. To confer the film with both water insolubility and flexibility without losing albumin characteristics, we searched a suitable condition for the cross‐linking of albumin. As a result, we found that a film having aimed properties could be obtained by conducting the cross‐linking reaction at room temperature for 24 h using 215 mM ethylene glycol diglycidyl ether. Mouse fibroblast L929 cells did not adhere on thus obtained film in a similar manner to a native albumin‐coated surface. In addition, the film could bind 2‐(4′‐hydroxyphenylazo)‐benzoic acid, a representative albumin binding dye, and gradually release it in a pH‐dependent manner. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Novel biochemical pathways of endoglin in vascular cell physiology
Authors: Bernabeu Carmelo , Conley Barbara A. , Vary Calvin P.H.
Published: November 2007

The broad role of the transforming growth factor beta (TGFβ) signaling pathway in vascular development, homeostasis, and repair is well appreciated. Endoglin is emerging as a novel, complex, and poorly understood regulatory component of the TGFβ receptor complex, whose importance is underscored by its recognition as the site of mutations causing hereditary hemorrhagic telangiectasia (HHT) [McAllister et al., 1994]. Extensive analyses of endoglin function in normal developmental mouse models [Bourdeau et al., 1999; Li et al., 1999; Arthur et al., 2000] and in HHT animal models [Bourdeau et al., 2000; Torsney et al., 2003] exemplify the importance of understanding endoglin's biochemical functions. However, novel mechanisms underlying the regulation of these pathways continue to emerge. These mechanisms include modification of TGFβ receptor signaling at the ligand and receptor activation level, direct effects of endoglin on cell adhesion and migration, and emerging roles for endoglin in the determination of stem cell fate and tissue patterning. The purpose of this review is to highlight the cellular and molecular studies that underscore the central role of endoglin in vascular development and disease. J. Cell. Biochem. 102: 1375–1388, 2007. © 2007 Wiley‐Liss, Inc.
Program‐like aging and mitochondria: Instead of random damage by free radicals
Authors: Blagosklonny Mikhail V.
Published: November 2007

As recently suggested, the target of rapamycin (TOR) pathway, rather than molecular damage by free radicals, drives aging and diseases of aging. But may mitochondria nevertheless contribute to aging? Here, I discuss aimless program‐like aging (versus altruistic program), conflict between the cell and mitochondria, cell murder (versus cell suicide) and the role of mitochondria in aging. In particular, life‐long selection among mitochondria may yield “selfish” (malignant) mitochondria resistant to autophagy. And TOR may create an intra‐cellular environment that is permissive for such selfish mitochondria. In theory, pharmacologic inhibitors of the TOR pathway may reverse accumulation of defective mitochondria, while also inhibiting the aging process. J. Cell. Biochem. 102: 1389–1399, 2007. © 2007 Wiley‐Liss, Inc.
NCAM‐induced intracellular signaling revisited
Authors: Ditlevsen Dorte Kornerup , Povlsen Gro Klitgaard , Berezin Vladimir , Bock Elisabeth
Published: November 2007

The neural cell adhesion molecule (NCAM) plays a crucial role in neuronal development, synaptic plasticity, and regeneration. NCAM works as “smart glue” that not only mediates cell–cell adhesion but also induces activation of a complex network of intracellular signaling cascades on homophilic or heterophilic binding. Stimulation of NCAM by homophilic interactions induces neuronal differentiation through activation of a number of signaling molecules, including the fibroblast growth factor receptor, non–receptor kinases Fyn and focal adhesion kinase, growth‐associated protein‐43, the mitogen‐activated protein kinase pathway, intracellular Ca2+, and protein kinases A, C, and G. This review presents and discusses the current knowledge in the area of NCAM signaling with a focus on the events involved in NCAM‐mediated neurite outgrowth. © 2007 Wiley‐Liss, Inc.
β‐Catenin and actin reorganization in HGF/SF response of ST14A cells
Authors: Soldati C. , Biagioni S. , Poiana G. , Augusti‐Tocco G.
Published: November 2007

Hepatocyte growth factor/scatter factor (HGF/SF) is a pleiotropic factor that activates proliferation, differentiation, and migration of various cell types. Its action is mediated by c‐Met, a receptor endowed with tyrosine kinase activity that activates complex signaling cascades and mediates diverse cell responses. Although HGF action was first demonstrated in epithelial cells, expression of HGF and c‐Met receptor has also been described in developing and adult mammalian brain. In the developing central nervous system, areas of HGF and c‐Met expression are coincident with the migratory pathway of precursor cells. In the present article we report that the interaction between c‐Met and HGF/SF in striatal progenitor ST14A cells triggers a signaling cascade that induces modification of cell morphology, with decreased cell–cell interactions and increased cell motility; in particular, we analyzed the reorganization of the actin cytoskeleton and the delocalization of β‐catenin and N‐cadherin. The testing of other neurotrophic factors (NGF, BDNF, NT3, and CNTF) showed that the observed modifications were peculiar to HGF. We show that phosphoinositide 3‐kinase inhibitor treatment, which blocks cell scattering induced by HGF/SF, does not abolish actin and β‐catenin redistribution. The effects of HGF/SF on primary spinal cord cell cultures were also investigated, and HGF/SF was found to have a possible motogenic effect on these cells. The data reported suggest that HGF could play a role in the early steps of neurogenesis as a motogenic factor. © 2007 Wiley‐Liss, Inc.
Modulatory effects of somatosensory electrical stimulation on neural activity of the dorsal cochlear nucleus of hamsters
Authors: Zhang Jinsheng , Guan Zhenlong
Published: November 2007

The effects of somatosensory electrical stimulation on the dorsal cochlear nucleus (DCN) activity of control and tone‐exposed hamsters were investigated. One to three weeks after sound exposure and control treatment, multiunit activity was recorded at the surface of the left DCN before, during, and after electrical stimulation of the basal part of the left pinna. The results demonstrated that sound exposure induced hyperactivity in the DCN. In response to electrical stimulation, neural activity in the DCN of both control and exposed animals manifested four response types: S‐S, suppression occurring during and after stimulation; E‐S, excitation occurring during stimulation and suppression after; S‐E, suppression occurring during stimulation and excitation after; and E‐E, excitation occurring during and after stimulation. The results showed that there was a higher incidence of suppressive (up to 70%) than of excitatory responses during and after stimulation in both groups. In addition, there was a significantly higher degree of suppression after, rather than during stimulation. At high levels of electrical current, the degree of the induced suppression was generally higher during and after stimulation in exposed animals than in controls. The similarity of our results to those of previous clinical studies further supports the view that DCN hyperactivity is a direct neural correlate of tinnitus and that somatosensory electrical stimulation can be used to modulate DCN hyperactivity. Optimization of stimulation strategy through activating only certain neural pathways and applying appropriate stimulation parameters may allow somatosensory electrical stimulation to be used as an effective tool for tinnitus suppression. © 2007 Wiley‐Liss, Inc.
Myocardial 123metaiodobenzylguanidine uptake in genetic Parkinson's disease
Authors: Quattrone Aldo , Bagnato Antonio , Annesi Grazia , Novellino Fabiana , Morgante Letterio , Savettieri Giovanni , Zappia Mario , Tarantino Patrizia , Candiano Innocenza Claudia Cirò , Annesi Ferdinanda , Civitelli Donatella , Rocca Francesca Emanuela , D'Amelio Marco , Nicoletti Giuseppe , Morelli Maurizio , Petrone Alfredo , Loizzo Piercostanzo , Condino Francesca
Published: November 2007

Myocardial 123Metaiodobenzylguanidine (MIBG) enables the assessment of postganglionic sympathetic cardiac innervation. MIBG uptake is decreased in nearly all patients with Parkinson's disease (PD). Our objective was to evaluate MIBG uptake in patients with genetic PD. We investigated MIBG uptake in 14 patients with PD associated with mutations in different genes (Parkin, DJ‐1, PINK1, and leucine‐rich repeat kinase 2 ‐LRRK2), in 15 patients with idiopathic PD, and 10 control subjects. The myocardial MIGB uptake was preserved in 3 of the 4 Parkin‐associated Parkinsonisms, in 1 of the 2 patients with DJ‐1 mutations, in 1 of the 2 brothers with PINK1 mutations, in 3 of the 6 unrelated patients with Gly2019Ser mutation in the LRRK2 gene, whereas it was impaired in all patients with idiopathic PD. MIBG was preserved in all control subjects. Our study shows that myocardial MIGB uptake was normal in 8 of 14 patients with genetic PD, suggesting that cardiac sympathetic denervation occurs less frequently in genetic PD than in idiopathic PD. Our findings also demonstrate that MIGB uptake has a heterogeneous pattern in genetic PD, because it was differently impaired in patients with different mutations in the same gene or with the same gene mutation. © 2007 Movement Disorder Society
User Behavior during the Book Selection Process
Authors: Wacholder Nina , Liu Lu , Liu Ying‐Hsang
Published: November 2007

We study user behavior during the stage of the book selection process when people study the content of a book to decide whether it will be useful for their intended purpose. 24 undergraduates participated in a balanced study in which they were given a topic‐book pair and asked to decide whether the book was useful for the topic; half of the book‐topic pairs were presented to participants in print and half electronically. We report on the impact of the medium on the book selection process and the outcome. This research contributes to our understanding of factors that influence the book selection process and has implications for the design of electronic books.
Analyzing organizational schemes of information resources in library websites by user education approaches
Authors: Kim Soojung
Published: November 2007

This paper examines the organizational schemes of information resources provided in 38 academic business libraries or collections from 50 top‐ranking business schools. A wide variety of schemes, ranging from a simple alphabetical list by database titles to research guides in which resources are inseparably embedded where relevant, were found to illustrate current practices in presenting information resources in the web‐based environment. In addition, the paper develops a typology by which the schemes are classified and assessed by resource integration dimension, resource/user orientation dimension, and user‐education approach dimension. This typology will assist in assessing existing schemes from the perspectives of both search and instruction as well as in developing new schemes.
Examining applications of motivational theories to the IT field
Authors: Parker Katie , Zhang Ping
Published: November 2007

Humans increasingly interact with information technology (IT) in order to attain both individual and organizational goals. As a result, studies applying motivational theories to the IT field gain importance in the research literature. Emerging from several different scholarly disciplines, motivational theories seek to explain why individuals do what they do (Reeve, 2005). This paper surveys applications of motivational theories to the IT field using citation analysis of each theory's seminal work. First, the authors identify three approaches that have been used by researchers applying motivational theories to the IT field. Second, the authors examine these applications using an IT lifecycle framework. Last, the authors propose possible directions for future research in this area.
Exploring multiple browser session behavior
Authors: MacKay Bonnie , Watters Carolyn
Published: November 2007

With the growth of information on the Web, users can perform more complex information seeking tasks. Users may finish tasks during one single session using their web browser, while other tasks may require the user to complete the task over many sessions.
Towards Quality Culture in the Digital Environ: Management and Optimization of Services in Research Libraries of India
Authors: Sherikar Amruth , Jange Suresh
Published: November 2007

National Assessment and Accreditation Council (NAAC) has been established in India for ensuring quality and excellence in higher education and has developed a set of objective indicators for the library, as it is the fulcrum of support for the community of academic and research pursuits. This resulted a general consensus for rising demands of evaluation and accountability of academic and research libraries to develop performance evaluation and measure service quality and thereby build quality culture. Advancements in Information and Communication technology, transforming the world into the global village, contributed significant scope for development of electronic information resources and Internet resources in the Library for continuous quality improvement. Library and information centers needs to map the information needs of the customers; well‐defined quality policy and Quality Circle and translating into quality information services, by making use of various Information Technology based information retrieval tools. The quality gurus especially Parasuraman, Barry, and Zeithaml have developed the SERVQUAL to measure the quality dimension in the academic and research environ to measure the perceptions of service quality.

In view of the emerging challenges for building quality culture in the techno‐environ, a total of 1200 questionnaires were distributed to the user community in Indian research libraries to go deeper into the realm of Quality Assessment and Use Techniques with a sincere effort to assess the performance of academic and research libraries in rendering their quality services to the users both from Librarians and users perceptions. Further, attempts were made to develop an instrument of acceptance of Internet technology known as Technology Acceptance Model (TAM) among faculty and Research scholars in India using the original constructs i.e. Perceived and Perceived Ease of Use. In this paper, efforts were also made to examine the relationship between the variables Use of Internet (UOI) and Level of Satisfaction (LOS), that resulted in coming out with a mathematical – regression model in which the results of Regression analysis shows that, the four variables age, teaching and research experience and level of satisfaction put together explains 39 per cent of variance in variable Use of Internet (UOI).

The paper concludes based on research findings, valuable suggestions to develop a National Information Policy for quality control as a mandatory to provide due importance in establishing Library and Information Centers as Centers of Learning and research. Of necessity, the strategies must be situation specific, but some possible strategies for libraries to use are identified for planned organizational change to quality improvement.
Single‐fiber electromyography of masseter muscle in myasthenia gravis
Authors: Khuraibet Adnan J. , Rousseff Rossen T. , Behbehani Raed , Al‐Shubaili Asmahan F.K. , Khan Riyadh A.
Published: November 2007

Jitter after axonal microstimulation in the masseter muscle was studied in 30 consecutive patients (12 women) with myasthenia gravis (MG). Patients' mean age was 42.3 (12–75), median disease duration was 3 months (1–72), and onset was ocular (15 cases), oculobulbar (7), bulbar (6), or generalized (2). There were 23 newly‐diagnosed patients. Nine cases developed purely ocular MG and 21 cases developed generalized MG. In the latter group, five subjects had a rapidly progressive course and 16 subjects had stable or well‐controlled disease (MGFA grade 2–3). Six patients did not have circulating anti–acetylcholine receptor antibodies. Masseter single‐fiber electromyography (SFEMG) was abnormal in 6 of 9 ocular MG patients and in all generalized cases (overall sensitivity 27 of 30 cases or 90%; confidence interval 79.3%–100.0% at P = 0.95). Masseter should be considered for SFEMG in diagnosis of MG, especially in cases with bulbar onset. Muscle Nerve, 2007
A new fictitious time for the dynamic relaxation (DXDR) method
Authors: Kadkhodayan M. , Alamatian J. , Turvey G. J.
Published: November 2007

This paper addresses the development of the DXDR method by introducing a modified fictitious time (MFT) increment. The MFT is determined by minimizing the residual force after each iteration. The rank of the convergence rate shows the advantage of the new method. The results obtained from plate and truss analyses demonstrate the potential of the new method. It is shown that, compared with a unit fictitious time, the MFT is more efficient, especially during the initial iterations. Moreover, MFT does not impose any additional constraints on the DXDR method. Copyright © 2007 John Wiley & Sons, Ltd.
New‐immigrant women in urban Canada: insights into occupation and sociocultural context
Authors: Martins Vanessa , Reid Denise
Published: November 2007

Recent statistics have shown that women from South Asia comprise one of the largest sub‐groups of immigrants to enter Canada. The majority of this population has settled in the city of Toronto. As immigrants adapt to new physical, social, political, and economic environments in a new country, they are also subject to changes in occupational roles and expectations. Little research has been conducted with new immigrant women from South Asia from an occupational adjustment perspective in Canada. This qualitative study sought to understand the adjustment experiences of immigrant women from South Asia regarding the influence of a Canadian urban environment on their occupations. Twelve recently immigrated women from South Asia to Canada were interviewed about their experiences of living in the city of Toronto with respect to their adjustment to a new environment and engagement in new daily occupations. Using a modified grounded theory approach to analysis, results from the study revealed many challenges these women face and the major factors that aid in the adjustment process. A framework for understanding occupational adjustment in new immigrants is discussed with implications for occupational therapy theory and practice. Copyright © 2007 John Wiley & Sons, Ltd.
Seeing white: a critical exploration of occupational therapy with Indigenous Australian people
Authors: Nelson Alison
Published: November 2007

This paper aims to critique current occupational therapy practice and theory using Indigenous Australian people as a case example. Critical race theory will be used to help question the privileged position of an occupational therapist from a dominant Westernized culture. In‐depth interviews were conducted with 15 (eight female and seven male) Indigenous Australian young people about their perspectives of health and physical activity. In addition, the Kawa model was used as an alternative data‐collection tool and detailed field notes and researcher reflections were used as data sources. Preliminary analysis of data is used to illustrate the ways in which critical race theory can inform occupational therapy practitioners and researchers about the ways Indigenous Australian young people view their health. Methodological dilemmas are also discussed. The paper is based on preliminary findings and further analysis needs to continue. Cross‐cultural research is inherently complex but can offer those from the dominant culture valuable insights into their taken‐for‐granted assumptions. Further use of critical race theory may prove useful as the occupational therapy profession continues to evolve its understanding of cultural safety. Copyright © 2007 John Wiley & Sons, Ltd.
Monte Carlo simulation of ferroelectric composites
Authors: Jiang S.L. , Liu D. , Tong J.Y. , Jin X.M.
Published: November 2007

On the basis of 0–3/1–3 mix‐connectivity model of composites, a new computer model was introduced to simulate the changing of small ceramic particle size of composites. Monte Carlo algorithm was applied to calculate the effects of particle size on dielectric constant, piezoelectric coefficient, pyroelectric coefficient, and other electrical parameters. Compared with other models, this new model was proved to be more reasonable. POLYM. COMPOS., 28:739–742, 2007. © 2007 Society of Plastics Engineers
Poetry: a reflective practice tool for nurses and midwives
Authors: Foureur Maralyn , Bush Rachel , Duke Jan , Walton Cate
Published: November 2007

This article describes the practice of a ‘poet‐in‐residence’ in a tertiary hospital in New Zealand, a country with a unique bicultural foundation. During her residency, the poet worked with hospital staff to gain insight into how nurses and midwives contribute to health outcomes. As well as creating 12 poems which make the work of nurses and midwives more visible, the poet provided poetry readings in two clinical areas and conducted a reflective practice exercise using the co‐creation of poetry, with a group of newly graduated nurses. This residency demonstrated the importance of connecting the world of science and technology with the world of lived experience and how poetry can help nurses and midwives to express the complexity of human care practice. Copyright © 2007 John Wiley & Sons, Ltd.
Step to it: a toolkit for evidence‐based practice
Authors: Ryton Bev , Grant Vicky , Little Alison , Gilsenan Irene
Published: November 2007

The ease with which evidence‐based practice can be applied will have a significant impact on whether it is effectively utilised by health care professionals. This article describes how members of the Evidence‐Based Council within Sheffield Teaching Hospitals NHS Foundation Trust resolved this issue by developing a user‐friendly toolkit and workbook which systematically introduces the key elements that need to be considered and applied in order to enhance evidence‐based practice at ward level. Copyright © 2007 John Wiley & Sons, Ltd.
Triboelectrostatic separation of covering plastics in chopped waste electric wire
Authors: Park Chul‐Hyun , Jeon Ho‐Seok , Cho Bong‐Gyoo , Park Jai‐Koo
Published: November 2007

To develop a triboelectrostatic separation technique for covering plastics in waste electric wire, process variables such as charger material, relative humidity, air velocity, electrode potential, and splitter position have been studied. Polypropylene was found to be the most effective material for a tribo‐charger in the separation of cross‐linked polyethylene (XLPE) and polyvinyl chloride (PVC). The charge density of XLPE and PVC was increased with deceasing relative humidity and increasing air velocity in the tribo‐charger. The charge density of a 1:1 mixture of XLPE and PVC was determined to be higher than that of individual XLPE and PVC. A dominant charging mechanism in the tribo‐charger with a 1:1 mixture of XLPE and PVC seems to be the charging of a combination of particle‐particle and particle‐charger surface. However, in case of individual plastics, the charging of particle‐particle occurred. Over 98.05% PVC recovery with 99.50% grade was successfully obtained under the conditions of a splitter position of +2 cm from the center, 25 kV electrode potential and over 13 nC/g PVC charge density for the optimum triboelectrostatic separation. POLYM. ENG. SCI., 47:1975–1982, 2007. © 2007 Society of Plastics Engineers
Miscibility and crystallization kinetics of poly(trimethylene terephthalate)/amorphous poly(ethylene terephthalate) blends
Authors: Chiu Hsiu‐Jung
Published: November 2007

The miscibility and crystallization kinetics of the blends of poly(trimethylene terephthalate) (PTT) and amorphous poly(ethylene terephthalate) (aPET) have been investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). It was found that PTT/aPET blends were miscible in the melt. Thus, the single glass transition temperature (Tg) of the blends within the whole composition range and the retardation of crystallization kinetics of PTT in blends suggested that PTT and aPET were totally miscible. The nucleation density of PTT spherulites, the spherulitic growth, and overall crystallization rates were depressed upon blending with aPET. The depression in nucleation density of PTT spherulites could be attributed to the equilibrium melting point depression, while the depression in the spherulitic growth and overall crystallization rates could be mainly attributed to the reduction of PTT chain mobility and dilution of PTT upon mixing with aPET. The underlying nucleation mechanism and growth geometry of PTT crystals were not affected by blending, from the results of Avrami analysis. POLYM. ENG. SCI., 47:2005–2011, 2007. © 2007 Society of Plastics Engineers
Phase structure and morphology of wollastonite‐reinforced polypropylene composites modified with SEBS and SEBS‐g‐MA elastomers
Authors: Švab Iztok , Musil Vojko , Jurkin Tanja , Šmit Ivan
Published: November 2007

Supermolecular structure of isotactic polypropylene/wollastonite/styrenic rubber block copolymers composites were studied as a function of elastomeric poly‐ (styrene‐b‐ethylene‐co‐butylene‐b‐styrene) triblock copolymer (SEBS) and the SEBS grafted with maleic anhydride (SEBS‐g‐MA) content (from 0 to 20 vol%) by optical, scanning, and transmission electron microscopy, wide‐angle X‐ray diffraction and differential scanning calorimetry. Wollastonite particles disturbed the spherulitization of polypropylene matrix. Both elastomers affected the crystallization of polypropylene matrix mainly by solidification effect. Although SEBS‐g‐MA encapsulated wollastonite particles more expressive than SEBS forming thus core‐shell morphology in higher extent, scanning electron micrographs indicated more constrained wollastonite particles in fractured surfaces of composites with SEBS elastomer. Moreover, SEBS‐g‐MA disorientated wollastonite particles and affected reorientation of the polypropylene crystallites stronger than SEBS elastomer. POLYM. ENG. SCI., 47:2145–2154, 2007. © 2007 Society of Plastics Engineers
Effects of surface roughness on microinjection molding
Authors: Zhang H.L. , Ong N.S. , Lam Y.C.
Published: November 2007

Injection molding is one of the most common processes for cost‐effective mass production of microplastic parts. When the dimensions of the part, and thus the cavity of the mold, are small, microscale factors which are normally neglected in the analysis of conventional injection molding may play an important role. This investigation addresses the effects of mold surface roughness on the injection of polymer melt, which is a non‐Newtonian fluid, during the filling stage of microinjection molding. The surface roughness effect on the volume of the mold cavity is discussed. A simple, but effective model, to describe the conductivity and the specific heat of the surface roughness is proposed. Subsequently, by employing the finite volume method and the level set method, a numerical procedure incorporating the proposed surface roughness model to describe the flow behavior of the polymer melt in the cavity is implemented. Finally, simulation on the melt flow injected into a microdisk cavity is performed using the proposed model and the results are found to be in good agreement with experiment. POLYM. ENG. SCI., 47:2012–2019, 2007. © 2007 Society of Plastics Engineers