bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil salinity dynamics in irrigated fields and its effects on paddy‐based rotation systems in southern Kazakhstan
Authors: Sugimori Y. , Funakawa S. , Pachikin K. M. , Ishida N. , Kosaki T.
Published: December 2007

Agricultural production in southern Kazakhstan has experienced significant economic difficulty since the 1980s, accelerating agronomic problems including the salinization of irrigated fields. A thorough understanding of the up‐to‐date situation of soil salinization and its effects on cropping systems is necessary in order to establish sustainable agricultural systems with avoiding land degradation for the region. This study examined the relationships between soil salinity, crop yield and affecting factors including local terrain for two farms. Both farms are characterised by a gentle slope, flat area and localised depressions. Most of the paddy fields showed wash‐out of salts during the irrigation period except in waterlogged fields situated in depressions. Rice yield was adversely affected by the remaining soil salinity, deep ponding water and insufficient drainage capacity in the lower part of the irrigation system. Salt accumulation in the upland fields appeared to increase with cropping years, and was associated with groundwater depth that became shallower at the lower parts of the irrigation systems, adversely affecting the crop growth in most fields. Since the cropping patterns had recently changed in the region, each pattern was compared against the recommendation of this study. Most patterns were concluded to be potentially effective for preventing soil salinization if conducted under an optimum economic and social system. Copyright © 2007 John Wiley & Sons, Ltd.
Safety and efficacy of N-acetylcysteine in children with non-acetaminophen-induced acute liver failure
Authors: Kortsalioudaki Christine , Taylor Rachel M. , Cheeseman Paul , Bansal Sanjay , Mieli-Vergani Giorgina , Dhawan Anil
Published: December 2007

Acute liver failure (ALF) carries a high mortality in children. N-acetylcysteine (NAC), an antioxidant agent that replenishes mitochondrial and cytosolic glutathione stores, has been used in the treatment of late acetaminophen-induced ALF and non-acetaminophen-induced ALF. In our unit, NAC was introduced as additional treatment for non-acetaminophen-induced ALF in 1995. The aim of this study was to evaluate the safety and efficacy of NAC in children with ALF not caused by acetaminophen poisoning. A retrospective review of medical records of 170 children presenting with nonacetaminophen-induced ALF between 1989 and 2004 was undertaken. ALF was defined as either international normalized ratio of prothrombin time (INR) > 2 and abnormal liver function or INR >1.5 with encephalopathy and abnormal liver function. Children were divided into the following groups: Group 1 (1989-1994), standard care (n = 59; 34 [58%] male; median age 2.03 yr, range 0.003-15.8 yr); and Group 2 (1995-2004), standard care and NAC administration (n = 111; 57 [51%] male; median age 3.51 yr, range 0.005-17.4 yr). NAC was administered as a continuous infusion (100 mg/kg/24 hours) until INR < 1.4, death, or liver transplantation (LT). The median duration of NAC administration in Group 2 was 5 (range, 1-77) days. Complications were noted in 8 (10.8%) children: rash in 3, arrhythmia in 3, and dizziness and peripheral edema in 1. One child had an allergic reaction (bronchospasm) and NAC was stopped. A total of 41 (71%) children in Group 1 vs. 85 (77%) in Group 2 required admission to intensive care, P = not significant (ns). The length of intensive care stay was 6 (range, 1-58) days in Group 1 vs. 5 (range, 1-68) days in Group 2, P = ns and length of hospital stay was 25 (range, 1-264) days vs. 19 (range, 1-201) days, P = 0.05. The 10-yr actuarial survival was 50% in Group 1 compared to 75% in Group 2, P = 0.009. Survival with native liver occurred in 13 (22%) in Group 1 vs. 48 (43%) in Group 2, P = 0.005; 15 (25%) in Group 1 died without transplant vs. 21 (19%) in Group 2, P = ns; and LT was performed in 32 (54%) vs. 42 (38%), P = ns. Death after transplantation occurred in 15 (39%) in Group 1 vs. 8 (16%) in Group 2, P = 0.02. In conclusion, NAC is safe in non-acetaminophen-induced ALF. In this retrospective study NAC was associated with a shorter length of hospital stay, higher incidence of native liver recovery without transplantation, and better survival after transplantation. Liver Transpl, 2007. © 2007 AASLD.
Greater travel time to a liver transplant center does not adversely affect clinical outcomes
Authors: Firozvi Amir A. , Lee Christine H. , Hayashi Paul H.
Published: December 2007

The effect of patient travel time to a transplant center on outcomes is unknown. We compared outcomes between patients living >3 hours (Group A) vs. ≤3 (Group B) hours drive away. Adult, nonacute liver failure patients entering transplant evaluation from February 27, 2002 to January 31, 2005 were analyzed. Of 166 patients, 126 (75.5%) were listed and 66 (39.5%) received transplantation. Outcomes of interest were >90 days to list, listing, survival while listed, transplantation, and posttransplantation survival. Covariates included Model for End-Stage Liver Disease (MELD) score, hepatocellular carcinoma (HCC), alcoholic liver disease, insurance type, and psychosocial score. There were 38 (23%) patients in Group A and 128 (77%) in Group B. Median MELD scores were 14.5 (range, 6–36) for Group A and 14.0 (range, 7–32) for Group B (p = 0.20). Groups were similar for age, gender, diagnosis, psychosocial score, insurance, and HCC variables. Group A was not independently associated with >90 days to list (odds ratio, 0.98; 95% confidence interval [CI], 0.4–2.4). Kaplan-Meier cumulative probabilities for listing, transplantation, and 1-yr posttransplantation survival were similar (A vs. B: 0.77 vs. 0.83, 0.70 vs. 0.69, and 0.85 vs. 0.86, respectively; all p values >0.05). Being in Group A remained insignificant in terms of probability of listing, transplantation, and posttransplantation survival by Cox proportional hazard modeling. Survival on the list was significantly better for Group A (A: 1.0, B: 0.55; p = 0.02). Fewer patients at high MELD score in Group A and referral biases may explain this difference. In conclusion, after entering evaluation, patients living >3 hours away from a transplant center have comparable outcomes to those living closer. Liver Transpl 14:18–24, 2008. © 2007 AASLD.
Liver transplantation for argininosuccinic aciduria: Clinical, biochemical, and metabolic outcome
Authors: Newnham Tanya , Hardikar Winita , Allen Katrina , Wellard Mark R. , Hamilton Charles , Angus Peter , Jones Robert , Boneh Avihu
Published: December 2007

We report successful liver transplantation in a young adult with argininosuccinic aciduria but without cirrhosis. Plasma amino acid profile normalized and brain magnetic resonance spectroscopy indicated improved metabolism after transplantation. The general well-being of the patient and his quality of life improved. We suggest that orthotopic liver transplantation should be considered for patients with argininosuccinic aciduria even in the absence of cirrhosis, with the aim of correcting (at least in part) central nervous system metabolism, thereby preventing further neurological deterioration. Liver Transpl 14:41–45, 2008. © 2007 AASLD.
Tacrolimus and cyclosporin doses and blood levels in hepatitis C and alcoholic liver disease patients after liver transplantation
Authors: Oo Ye H. , Dudley Tracey , Nightingale Peter , Haydon Geoffrey , Mutimer David
Published: December 2007

Hepatitis C virus (HCV)-induced cirrhosis is the most common indication for liver transplantation (LT). However, graft reinfection is nearly universal. The choice of immunosuppression, including the calcineurin inhibitor (CNI), may have some effect on severity of recurrence and graft survival. In addition, HCV recurrence may have some impact on metabolism of immunosuppressive drugs. In this retrospective study, we examined the dose and blood levels of tacrolimus (TAC) and cyclosporin A (CYA) in HCV patients consecutively undergoing transplantation (TAC, n = 44; CYA, n = 60) and surviving 12 months post-LT. In addition, we examined the CNI dose and blood levels in an age- and gender-matched comparison group of patients who were transplanted for alcoholic liver disease (ALD) (TAC, n = 44; CYA, n = 47). During the 12-month period of observation, TAC levels were significantly higher for HCV than for ALD patients (P = 0.002). The dose of TAC decreased over time for both HCV and ALD patients (P < 0.001), but the reduction was greater for HCV patients (P = 0.03). CYA dose decreased over time for both groups (P < 0.001) but a greater reduction was observed for the HCV group (P = 0.007). For both HCV and ALD patients, CYA levels decreased over time (P < 0.001) but there was no significant difference between HCV and ALD patients. Thus, to maintain comparable blood levels, a greater reduction of dose was required for HCV than for ALD patients. In conclusion, our observations demonstrate a likely effect of HCV infection on CNI metabolism, an effect that is not clearly due to graft damage. Physicians need to be alert to this interaction and to the need to respond quickly to changes in CNI levels that may be associated with HCV infection and with HCV clearance during antiviral therapy. Liver Transpl 14:81–97, 2008. © 2007 AASLD.
Regularization in model updating
Authors: Titurus B. , Friswell M. I.
Published: December 2007

This paper presents the theory of sensitivity‐based model updating with a special focus on the properties of the solution that result from the combination of optimization of the response prediction with a priori information about the uncertain parameters. Model updating, together with the additional regularization criterion, is an optimization with two objective functions, and must be linearized to obtain the solution. Structured solutions are obtained, based on the generalized singular value decomposition (GSVD), and specific features of the parameter and response paths as the regularization parameter varies are explored. The four different types of spaces that arise in the solution are discussed together with the characteristics of the regularized solution families. These concepts are demonstrated on a simulated discrete example and on an experimental case study. Copyright © 2007 John Wiley & Sons, Ltd.
Stabilization of bi‐linear mixed finite elements for tetrahedra with enhanced interpolation using volume and area bubble functions
Authors: Mahnken Rolf , Caylak Ismail
Published: December 2007

In order to overcome the oscillatory effects of the mixed bi‐linear Galerkin formulation for tetrahedral elements, a stabilization approach is presented. To this end the mixed method of incompatible modes and the mixed method of enhanced strains are reformulated, thus giving both the interpretation of a mixed finite element method with stabilization terms. For non‐linear problems, these are non‐linearly dependent on the current deformation state and therefore are replaced by linearly dependent stabilization terms. The approach becomes most attractive for the numerical implementation, since the use of quantities related to the previous Newton iteration step, typically arising for mixed‐enhanced elements, is completely avoided. The stabilization matrices for the mixed method of incompatible modes and the mixed method of enhanced strains are obtained with volume and area bubble functions. Various numerical examples are presented, which illustrate successfully the stabilization effect for bi‐linear tetrahedral elements. Copyright © 2007 John Wiley & Sons, Ltd.
U.S. nonprofit organizations' demand for temporary foreign professionals
Authors: Tschirhart Mary , Wise Lois Recascino
Published: December 2007

This article examines the demand by nonprofits in the United States for foreign professionals to fill a variety of specialized and managerial positions on a temporary basis. Our study contributes to understanding the demand side of the trend toward a more contingent workforce. We test predictors of nonprofit employers' pursuit of foreign labor for professional expertise and show an association between strategy to insource foreign labor and organizational resource level, mission, occupational need, and wage offer. Our findings suggest that government visa policies and practices affect labor pools for nonprofit organizations. Given that our study reveals varied interest by nonprofits in pursuing temporary foreign professionals, we end with a brief review and discussion of how the use of temporary and foreign professionals may influence the dynamics of nonprofit organizations and suggest additional research questions.
The relational determinants of nonprofit Web site fundraising effectiveness: An exploratory study
Authors: Sargeant Adrian , West Douglas C. , Jay Elaine
Published: December 2007

In this article, we develop a framework for assessing the relational content of nonprofit Internet sites. We operationalize this as a series of eight relational constructs applicable to the context of Web site design and operation and explore the relationship between the presence of these dimensions and the fundraising performance of nonprofit Web sites. We conclude that accessibility, accountability, education, interaction, and empowerment are significantly correlated with the number of new donors a site is able to attract, and that accessibility, accountability, and education are also highly correlated with the total value of online donations offered.
An expanded theory of pluralistic interactions in voluntary nonprofit organizations
Authors: Weisinger Judith Y. , Salipante Paul F.
Published: December 2007

Demographic trends suggest a more culturally diverse society, yet research focusing specifically on the management of this diversity in nonprofit organizations is at a nascent stage. Furthermore, traditional ways of conceptualizing cultural diversity in U.S. society are becoming outmoded. Thus, nonprofit managers and leaders can benefit from new ways of thinking about and managing diversity.

In this article, we extend our proposed representationinteraction model of diversity in voluntaristic nonprofits (Weisinger and Salipante, 2005) by more closely examining the interaction prong of our model in order to provide a more grounded understanding of this new approach to increasing pluralism. The expanded model that we discuss here is founded on interaction processes: in‐group identity and recategorization. This study enables us to transform our grounded theory into a theory of practices that leaders of voluntaristic organizations can directly apply. We present findings from a field study of a national nonprofit organization and discuss implications for practice and research.
Collaborations with faith‐based social service coalitions
Authors: Ebaugh Helen Rose , Chafetz Janet S. , Pipes Paula F.
Published: December 2007

Based on the first national survey of faith‐based social service coalitions in the United States, this article presents data on the degree to which these nonprofit organizations collaborate with other specific organizational types, as well as the range and intensity of these collaborations. In general, faith‐based coalitions tend to collaborate most frequently with other faith‐based agencies, a pattern especially characteristic of the more religiously expressive ones. However, collaboration with non‐faith‐based organizations is also quite common. Based on seven organizational characteristics, we are able to predict which faith‐based coalitions are most likely to collaborate with different types of organizations: coalitions that have more explicitly religious policies and practices with reference to clients and staffs are less likely to participate in intense collaborations with some types of secular organizations, and consistently less likely to do so with all types of governmental agencies.
Contributions of unrestricted funds: The donor organization–public relationship and alumni attitudes and behaviors
Authors: Wright Marshal H. , Bocarnea Mihai C.
Published: December 2007

This exploratory pilot study examined alumni attitudes and behaviors toward making contributions in a nonprofit higher education organizational setting. The theoretical base of the study was that nonprofit higher education organizations operate in competitive marketing environments within a resource dependence open systems framework. In an effort to better understand alumni donor attitudes and behaviors in this context, this research explored the predictive relationship between the donor organization–public relationship (OPR) and alumni donor attitudes toward willingness to contribute unrestricted funds and donor behaviors concerning size of gifts made, frequency per year of contributions, and frequency of years of contributions using Huang's (2001) organization–public relationship assessment. Results indicate that donor OPR significantly predicts alumni donor attitudes toward willingness to contribute unrestricted funds. The results do not support that donor OPR significantly predicts size of gifts made, frequency per year of contributions, and frequency of years of contributions.
Innovation, accountability, and independence at three private foundations funding higher education civic engagement, 1995 to 2005
Authors: Ostrander Susan A.
Published: December 2007

This case study looks at changes in private foundation funding for higher education civic engagement from 1995 to 2005. The focus is three large, established foundations that were U.S. national leaders in supporting this activity during these years: Carnegie, Pew, and Kellogg. Data sources include (1) in‐depth conversations with four strategically placed foundation insiders and six nationally recognized campus leaders and (2) scans of Web sites of the three foundations that document the change in funding priorities over time, plus Web sites of the main campus initiatives supported and national campus civic engagement organizations such as Campus Compact. Research findings con‐ firm and specify other studies that suggest that foundations shift their funding priorities according to their perceived role as innovators, pressures to be accountable and show clear results, and their independence as private organizations. The article concludes by raising questions about private foundations generally in relation to issues of innovativeness, accountability, and independence.
Olfactory and gustatory sensory changes to tobacco smoke in pregnant smokers
Authors: Pletsch Pamela K. , Pollak Kathryn I. , Peterson Bercedis L. , Park Jeongok , Oncken Cheryl A. , Swamy Geeta K. , Lyna Pauline
Published: December 2007

Models of smoking behavior change include addiction, social, and behavioral concepts. The purpose of this study was to explore the prevalence of two biologic factors, olfactory and gustatory responses to tobacco smoke, as potentially powerful contributors to smoking behavior change among pregnant women. Data were obtained from 209 pregnant smokers. The majority of women reported olfactory (62%) and gustatory (53%) aversions to tobacco. Aversions first appeared during the first trimester of pregnancy. Women who experienced olfactory aversions were more likely also to experience gustatory aversions. Olfactory aversions were associated with women smoking less. Aversions to tobacco smoke are common among pregnant smokers, are associated with women smoking less, and could help explain pregnant women's smoking patterns. © 2007 Wiley Periodicals, Inc. Res Nurs Health 31:31–41, 2008
The highway code of T cell trafficking
Authors: Marelli‐Berg FM , Cannella L , Dazzi F , Mirenda V
Published: December 2007

Coordinated migratory events are required for the development of effective and regulated immunity. Naïve T lymphocytes are programmed to recirculate predominantly in secondary lymphoid tissue by non‐specific stimuli. In contrast, primed T cells must identify specific sites of antigen location in non‐lymphoid tissue to exert targeted effector responses. Following priming, T cells acquire the ability to establish molecular interactions mediated by tissue‐selective integrins and chemokine receptors (homing receptors) that allow their access to specific organs, such as the skin and the gut. Recent studies have shown that an additional level of specificity is provided by the induction of specific T cell migration into the tissue following recognition of antigen displayed by the endothelium. In addition, co‐stimulatory signals (such as those induced by CD28 and CTLA‐4 molecules) have been shown not only to regulate T cell activation and differentiation, but also to orchestrate the anatomy of the ensuing T cell response. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
TNF‐mediated inflammatory disease
Authors: Bradley JR
Published: December 2007

TNF was originally described as a circulating factor that can cause necrosis of tumours, but has since been identified as a key regulator of the inflammatory response. This review describes the known signalling pathways and cell biological effects of TNF, and our understanding of the role of TNF in human disease. TNF interacts with two different receptors, designated TNFR1 and TNFR2, which are differentially expressed on cells and tissues and initiate both distinct and overlapping signal transduction pathways. These diverse signalling cascades lead to a range of cellular responses, which include cell death, survival, differentiation, proliferation and migration. Vascular endothelial cells respond to TNF by undergoing a number of pro‐inflammatory changes, which increase leukocyte adhesion, transendothelial migration and vascular leak and promote thrombosis. The central role of TNF in inflammation has been demonstrated by the ability of agents that block the action of TNF to treat a range of inflammatory conditions, including rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease and psoriasis. The increased incidence of infection in patients receiving anti‐TNF treatment has highlighted the physiological role of TNF in infectious diseases. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Optimizing maximum equivalent strain on solder balls in flip‐chip packages
Authors: Wu G.H. , Ju S.H. , Hsu T.C. , Lai H.Y. , Hwang W.M.
Published: December 2007

Flip‐chip packaging provides a high‐performance low‐cost approach for development of electronic packages. A three‐dimensional (3D) viscoelastic‐plastic finite element analysis using the commercial software ANSYS has been performed to study the thermo‐mechanical behavior in flip‐chips assemblies, i.e., the four components: chip, solder ball, underfill, and substrate. The viscoelastic behavior of underfill is modeled by a Maxwell constitutive equation, while the viscoplastic behavior of solder balls is modeled by an Anand model. Both chip and substrate are assumed to elastic materials modeled by Hooke's law. As in standard industry practice, temperature cycling from 125 to −40°C is used. Thermo‐mechanical behavior of solder balls is presented, and the effects of underfill material properties are investigated. Further, Taguchi methods are used to optimize flip‐chip package performance. The design goal is to minimize the maximum equivalent strain on the solder balls. The eight flip‐chip assembly factors chip‐thickness/substrate‐thickness ratio, underfill modulus (Gi), underfill relaxation time (λi), solder height‐to‐diameter ratio, chip coefficient of thermal expansion (CTE), underfill CTE, solder CTE, and substrate CTE are chosen for optimization. POLYM. COMPOS., 2008. © 2007 Society of Plastics Engineers
Synthesis and studies of the physical properties of polyaniline and polyurethane‐modified epoxy composites
Authors: Chiou Wen‐Chin , Han Jin‐Lin , Lee Sung‐Nung
Published: December 2007

Two series of toughened, semiconductive polyaniline (PANI)/polyurethane (PU)‐epoxy (PANI/PU‐EPOXY) nano‐composites were prepared using a conductive polymer, PANI, and PU prepolymer‐modified‐diglycidyl ether of bisphenol A (DGEBA) epoxy. First, the PU prepolymer‐modified epoxy oligomer was synthesized by a stoichiometric reaction between the terminal isocyanate groups of the PU prepolymer and the pendent hydroxyl groups of the epoxide. PU prepolymers were made either of polyester (polybutylene adipate, PBA) or polyether (polypropylene glycol, PPG) segments. The composites were characterized by thermal, morphological, mechanical, and electrical studies. Impact strength was enhanced 100% in PU (PPG 2000)‐modified composites; whereas, only ca. 30–50% increases in impact strength were observed for the other modified composites. In addition, the thermal stability of this composite proved superior to that of neat epoxy resin, regardless of a PU content at 27.5 wt%. Scanning electron microscopy (SEM) morphology study showed that the spherical PU (PPG 2000) particles (ca. 0.2–0.5 μm) dispersed within the matrix accounts for these extraordinary properties. The conductivity of the composite increased to ca. 10−9–10−3 S cm−1 upon addition of PANI when tested in the frequency range 1 kHz–13 MHz. This study demonstrated a useful way to simultaneously improve the toughness and conductivity of the epoxy composite, thus rendering it suitable for electromagnetic interference and various charge dissipation applications. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Investigations on the morphology and melt crystallization of poly(L‐lactide)‐poly(ethylene glycol) diblock copolymers
Authors: Wu Tong , He Yong , Fan Zhongyong , Wei Jia , Li Suming
Published: December 2007

Ring opening polymerization of L‐lactide was realized in the presence of monomethoxy poly(ethylene glycol), using zinc lactate as catalyst. The resulting PLLA‐PEG diblock copolymers were characterized by using 1H‐NMR, SEC, WAXD, and DSC. All the copolymers were semicrystalline, one or two melting peaks being detected depending on the composition. Equilibrium melting temperature (Tm0) of PLLA blocks was determined for three copolymers with different EO/LA molar ratios. Tm0 decreased with decreasing PLLA block length. A copolymer with equivalent PLLA and PEG block lengths was selected for melt crystallization studies and the resulting data were analyzed with Avrami equation. The obtained Avrami exponent is equal to 2.6 ± 0.2 in the crystallization temperature range from 80 to 100°C. In addition, the spherulite growth rate of PLLA‐PEG was analyzed by using Lauritzen‐Hoffmann theory in comparison with PLLA homopolymers. The nucleation constant was found to be 2.39 × 105 K2 and the free energy of folding equal to 53.8 erg/cm2 in the range of 70–94°C, both higher than those of PLLA homopolymers, while the spherulite growth rate of the diblock copolymer was lower. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Cracking formation on the surface of extruded photodegraded polypropylene plates
Authors: Fechine G.J.M. , Demarquette N.R.
Published: December 2007

The cracking formation during the photodegradation of polypropylene (PP) plates (1 mm thickness), with (PPOx) and without pro‐oxidant (PP), has been investigated. The plates were produced by extrusion in an industrial production line and were exposed to ultraviolet radiation in the laboratory for periods of up to 480 hr. The samples were investigated by infrared spectroscopy—FTIR, optical light microscopy, differential scanning calorimetry (DSC) and X‐ray diffraction (XRD). The results showed that the extension of photodegradation process is more intense for PPOx than for PP samples. For both samples, cracks were formed at the surface perpendicularly to the flow‐lines. However the cracks frequency was different for both samples and sides of sample. The crack frequency was correlated with chain orientation, A110; it was shown that lower degrees of orientation resulted in lower crack frequency. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Mechanical, thermal, and morphological behavior of the polyamide 6/acrylonitrile–butadiene–styrene blends irradiated with gamma rays
Authors: Hassan Medhat M.
Published: December 2007

Polymeric materials with improved properties can be obtained through polymer blends. As a polymer mixture is generally immiscible and incompatible, it is necessary to use compatibilizers to improve the interfacial adhesion. Polyamide 6 (PA‐6) is an attractive polymer to engineering applications; however, it reveals processing instability and relatively low‐notched impact strength. This behavior can be modified by blending with acrylonitrile–butadiene–styrene (ABS) copolymer. In this study, blends of PA‐6 with ABS were prepared using gamma irradiation, and the effects of ABS and ionizing radiation on the properties of PA‐6/ABS blends were investigated by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) techniques. The data showed that the presence of ABS (30 wt%) in the blend decreased the tensile strength and elongation at break with respect to pure PA‐6. The decrease in the mechanical property was observed at doses 30 and 50 kGy. ABS showed strong effect on the crystallization of PA‐6 in the PA‐6/ABS binary blends. All irradiated blends are thermally more stable than those non‐irradiated. Chemical changes can be clearly seen in FTIR spectra through two bands assigned for NH and OH groups. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Electrospinning and alignment of polyaniline‐based nanowires and nanotubes
Authors: Attout A. , Yunus S. , Bertrand P.
Published: December 2007

Polyaniline (PANi) nanowires and nanotubes are processed by electrospinning. Nanowires are electrospinned using PANi/PEO and PANi/PMMA polymer blends. The morphology and composition of these nanofibers are determined by scanning electron microscopy (SEM) and Nano‐Secondary Ion Mass Spectrometry (Nano‐SIMS). The conductive polymer seems more homogeneously distributed for the PANi/PEO than for the PANi/PMMA blend nanowires, which exhibit a phase separation. On the other hand, pure PANi nanotubes are prepared using PMMA nanowires as a template. The synthesis is followed by X‐ray photoelectron spectroscopy (XPS), SEM and Nano‐SIMS. Moreover, a simple method based on electrostatic steering allows us to align these fibers on a substrate. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Predicting deflagration to detonation transition in hydrogen explosions
Authors: Middha Prankul , Hansen Olav R.
Published: December 2007

Because of the development in computational resources, Computational Fluid Dynamics (CFD) has assumed increasing importance in recent years as a tool for predicting the consequences of accidents in petrochemical and process industries. CFD has also been used more and more for explosion predictions for input to risk assessments and design load specifications. The CFD software FLACS has been developed and experimentally validated continuously for more than 25 years. As a result, it is established as a tool for simulating hydrocarbon gas deflagrations with reasonable precision and is widely used in petrochemical industry and elsewhere. In recent years the focus on predicting hydrogen explosions has increased, and with the latest release the validation status for hydrogen deflagrations is considered good.

However, in many of these scenarios, especially involving reactive gases such as hydrogen, deflagration to detonation transition (DDT) may be a significant threat. In previous work, FLACS was extended to identify whether DDT is likely in a given scenario and indicate the regions where it might occur. The likelihood of DDT has been expressed in terms of spatial pressure gradients across the flame front. This parameter is able to visualize when the flame front captures the pressure front, which is the case in situations when fast deflagrations transition to detonation. Reasonable agreement was obtained with experimental observations in terms of explosion pressures, transition times, and flame speeds. The DDT model has now been extended to develop a more meaningful criterion for estimating the likelihood of DDT by comparison of the geometric dimensions with the detonation cell size. This article discusses the new models to predict DDT, and compare predictions with relevant experiments. © 2007 American Institute of Chemical Engineers Process Saf Prog 2008
Fate of glyphosate in soil and the possibility of leaching to ground and surface waters: a review
Authors: Borggaard Ole K , Gimsing Anne Louise
Published: December 2007

The very wide use of glyphosate to control weeds in agricultural, silvicultural and urban areas throughout the world requires that special attention be paid to its possible transport from terrestrial to aquatic environments. The aim of this review is to present and discuss the state of knowledge on sorption, degradation and leachability of glyphosate in soils. Difficulties of drawing clear and unambiguous conclusions because of strong soil dependency and limited conclusive investigations are pointed out. Nevertheless, the risk of ground and surface water pollution by glyphosate seems limited because of sorption onto variable‐charge soil minerals, e.g. aluminium and iron oxides, and because of microbial degradation. Although sorption and degradation are affected by many factors that might be expected to affect glyphosate mobility in soils, glyphosate leaching seems mainly determined by soil structure and rainfall. Limited leaching has been observed in non‐structured sandy soils, while subsurface leaching to drainage systems was observed in a structured soil with preferential flow in macropores, but only when high rainfall followed glyphosate application. Glyphosate in drainage water runs into surface waters but not necessarily to groundwater because it may be sorbed and degraded in deeper soil layers before reaching the groundwater. Although the transport of glyphosate from land to water environments seems very limited, knowledge about subsurface leaching and surface runoff of glyphosate as well as the importance of this transport as related to ground and surface water quality is scarce. Copyright © 2007 Society of Chemical Industry
Extract of Ginkgo biloba induces glutamate cysteine ligase catalytic subunit (GCLC)
Authors: Liu Xiao‐Ping , Goldring Christopher E. P. , Wang Hai‐Yi , Copple Ian M. , Kitteringham Neil R. , Park B. Kevin , Wei Wei
Published: December 2007

The extract of Ginkgo biloba (EGb), containing 24% flavone glycosides and 6% terpenoids, is widely used to treat early‐stage Alzheimer's disease, vascular dementia, peripheral claudication and vascular tinnitus. Its marked antioxidant activity has recently been demonstrated in both cell lines and animals. Glutathione (GSH) plays an important role in the antioxidant system by conjugating to xenobiotics to facilitate their export from cells. Glutamate cysteine ligase (GCL) is the rate‐limiting enzyme for GSH synthesis and its catalytic subunit (GCLC) determines this de novo synthesis. Thus, induction of GCLC is a strategy to enhance the antioxidant capability in cells. The present study aimed to investigate the induction effect of EGb on GCLC in HepG2 and Hep1c1c7 cell lines. Real‐time PCR, Western blot and enzyme activity assay were used to detect induction and it was found that GCLC was induced by EGb in these two cell lines. It is suggested that the antioxidant activity of EGb is (or is partly) through the induction of GCLC. Copyright © 2007 John Wiley & Sons, Ltd.
Inhibitory effect of Ginkgo Biloba extract on hyperhomocysteinemia‐induced intimal thickening in rabbit abdominal aorta after balloon injury
Authors: Liu Fenye , Zhang Jidong , Yu Shudong , Wang Rong , Wang Bo , Lai Liping , Yin Huiqiu , Liu Guilin
Published: December 2007

Ginkgo biloba extract (GBE) has been widely used to treat cardiovascular and cerebrovascular disorders. Hyperhomocysteinemia (Hhcy) is associated with the risk of atherosclerosis and restenosis after angioplasty. The objective of this study was to investigate whether GBE could attenuate the Hhcy‐induced intimal thickening after balloon injury in rabbit abdominal aorta. It was observed in this study that GBE could decrease the neointima area (NA) and the ratio of the neointima area to the media area (NA/MA), down‐regulate the mRNA expression of matrix metalloproteinase‐9 (MMP‐9) and up‐regulate the protein expression of p21 WAF1/CIP1 (p21). It suggests that GBE can reverse the Hhcy‐induced neointima formation in rabbits following balloon injury, and the suppressive effect of GBE on the migration and proliferation of vascular smooth muscle cells (VSMCs) may contribute to its actions. Copyright © 2007 John Wiley & Sons, Ltd.
Process modeling by process owners: A decentralized approach
Authors: Turetken Oktay , Demirors Onur
Published: December 2007

Majority of current methods for process modeling utilize a centralized approach in which a group of experts work with the agents to understand, model, and improve the organization's processes. This article proposes a novel approach for process modeling that is based on the idea that modeling organizations' processes can be performed by process owners—individuals actually performing the processes. Instead of having a centralized and devoted group of people, process performers are held responsible for the model and improve their own processes concurrently and in a decentralized manner. The article also summarizes the lessons learned by the application of the method in two organizations. Copyright © 2008 John Wiley & Sons, Ltd.
New Technologies for the Surgical Curriculum
Authors: Aggarwal Rajesh , Leong Julian , Leff Daniel , Warren Oliver , Yang Guang‐Zhong , Darzi Ara
Published: December 2007

The aim of a surgical residency program is to produce competent professionals displaying the cognitive, technical, and personal skills required to meet the needs of society. Current changes to the delivery of healthcare necessitate the development of new models of training. These can be supported with the development of new technologies to train and assess surgical practitioners. This article describes recent developments within Imperial College London with regard to eye tracking, noninvasive brain imaging, and an innovative mentoring scheme for the new surgical curriculum. The concept of eye tracking is described, together with surgical application for this technique in terms of dexterity analysis during minimally invasive procedures. We have also begun to understand spatial localization within the brain cortex during surgical knot‐tying tasks. The aim is to develop a map of the cortex with regard to surgical novices and experienced surgeons and then to develop the hypothesis that a translational process of cortical plasticity occurs during training. Finally, the article is intended to describe a training scheme that goes beyond dexterity, and moves toward the development of a successful surgeon through surgical mentoring. It is hoped that some of these tools will enhance the training of future surgeons in order to continue to provide a high‐quality service to our patients.
Elevated microsomal prostaglandin‐E synthase‐1 in Alzheimer's disease
Authors: Chaudhry Uzma A. , Zhuang Hean , Crain Barbara J. , Doré Sylvain
Published: December 2007

Background

The proinflammatory prostaglandin E2 (PGE2) fluctuates over time in the cerebrospinal fluid of patients with Alzheimer's disease (AD), but the cerebral distribution and expression patterns of microsomal prostaglandin‐E synthase (mPGES)–1 have not been compared with those of normal human brains.

Methods

Middle frontal gyrus tissue from AD and age‐matched control brains was analyzed by Western blot, immunofluorescence, and immunohistochemistry with mPGES‐1–specific antibodies.

Results

Western blotting revealed that mPGES‐1 expression was significantly elevated in AD tissue. Furthermore, immunofluorescence of mPGES‐1 was observed in neurons, microglia, and endothelial cells of control and AD tissue. Although mPGES‐1 was consistently present in astrocytes of control tissue, it was present in only some astrocytes of AD tissue. Immunohistochemical staining suggested that mPGES‐1 was elevated in pyramidal neurons of AD tissue when compared with controls.

Conclusions

The results suggest that mPGES‐1 is normally expressed constitutively in human neurons, microglia, astrocytes, and endothelial cells but is up‐regulated in AD.
A three‐dimensional microstructure‐based photon‐tracking model of radiative transfer in snow
Authors: Kaempfer T. U. , Hopkins M. A. , Perovich D. K.
Published: December 2007

Solar radiation is a key component of the energy budget of snow‐covered landscapes. Even a thin snow cover reflects most of the incident sunlight and transmits little. An understanding of the interaction of solar radiation with snow is essential to the study of the snow thermodynamics, chemistry, hydrology, ecology, and remote sensing. To investigate this interaction, a microstructure‐based photon‐tracking algorithm is presented. The three‐dimensional snow microstructure is provided either by a discrete element model defined by shape, size, and spatial arrangement of individual ice grains or by an X‐ray microtomography image of a snowpack. The model uses refraction, Fresnel reflection, and absorption laws, and the only optical input parameters are the complex index of refraction and absorption coefficient. The model follows individual photons through the microstructure, a porous network of ice and air, applying the fundamental optics laws at the ice‐air interfaces and within the ice. By firing tens of thousands of photons a detailed examination of the spectral radiance and irradiance above, below, and within the snowpack is possible. The model was compared to results from a discrete ordinates model, and its sensitivity to the microstructural representation was studied. It was applied to investigate changes in reflected, absorbed, and transmitted light as a function of wavelength, snow depth, grain size, and snow density, used to predict the amount and direction of scattering within the snowpack, and used to explore the interaction of a collimated beam with snow.
Global distribution of CT2 at altitudes 30–50 km from space‐borne observations of stellar scintillation
Authors: Gurvich A. S. , Sofieva V. F. , Dalaudier F.
Published: December 2007

Locally isotropic turbulence in the stratosphere consists of isolated sporadic patches with random values of temperature structure characteristic CT2. Stellar scintillations measured aboard GOMOS/ENVISAT through the Earth atmosphere provided the first global distribution of the effective characteristic CT,eff2 averaged along sounding ray. For zonal mean, the largest values are achieved in winter polar regions. This observed intense turbulence is probably related to the polar night jet. Relatively weak turbulence is observed at low latitudes. Turbulence intensity map is shown for altitude 42 km in the latitude band ±35°, where the maxima follow the sub‐solar latitude, with enhancements located mainly over continents. Turbulence enhancements are not related with orography. Despite a noticeable correlation with typical regions of deep convection, the overall distribution of CT,eff2 displays a more complicated structure. Analyzed data suggest that the main turbulence sources, at altitudes ∼40 km, are instabilities of stratospheric circulation and gravity wave breaking.
A strict test in climate modeling with spectrally resolved radiances: GCM simulation versus AIRS observations
Authors: Huang Yi , Ramaswamy V. , Huang Xianglei , Fu Qiang , Bardeen Charles
Published: December 2007

The spectrally resolved infrared radiances observed by AIRS provide a strict and insightful test for general circulation models (GCMs). We compare the clear‐ and total‐ sky spectra simulated from the Geophysical Fluid Dynamics Laboratory GCM using a high resolution radiation code with the AIRS observations. After ensuring consistency in the sampling of the observed and simulated spectra and a proper representation of clouds in the radiance simulation, the observed and simulated global‐mean radiances are shown to agree to within 2 K in the window region. Radiance discrepancies in the water vapor v2 (1300–1650 cm−1) and carbon dioxide v2 (650–720 cm−1) bands are consistent with the model biases in atmospheric temperature and water vapor. The existence of radiance biases of opposite signs in different spectral regions suggests that a seemingly good agreement of the model's broadband longwave flux with observations may be due to a fortuitous cancellation of spectral errors. Moreover, an examination of the diurnal difference spectrum indicates pronounced biases in the model‐simulated diurnal hydrologic cycle over the tropical oceans, a feature seen to occur in other GCMs as well.
Digital terrain mapping of the underside of sea ice from a small AUV
Authors: Wadhams P. , Doble M. J.
Published: December 2007

In April 2007 the first three‐dimensional digital terrain mapping of the underside of sea ice to be done from an ice‐launched autonomous underwater vehicle (AUV) was carried out at an ice camp in the Beaufort Sea using the Gavia vehicle, which could be launched and recovered through 3 × 1 m holes. Gavia was equipped with a GeoSwath 500 kHz interferometric sonar system, which yielded swaths of typical width 80 m. The imagery showed the morphological distinctions between first‐year (FY) and multi‐year (MY) ice undersides, the contrast between the shapes of FY and MY ridges, and the appearance of refrozen leads. Ice drafts were validated by drilling, and it was found that ridge slope statistics and local probability density functions (PDFs) of draft could be derived with high precision. The special opportunities offered by access to 3‐D mapping are pointed out.
Multi‐static, common volume radar observations of meteors at Jicamarca
Authors: Malhotra Akshay , Mathews John D. , Urbina Julio
Published: December 2007

Multi‐static, common volume radar (MSCVR) observations have long been considered necessary for meteor observations, especially for the study of Range Spread Trail Echoes (RSTE). We present preliminary results ‐ in the form of a case study ‐ from the first MSCVR observations that were carried out at the Jicamarca Radar Observatory (JRO) in June 2007. A second antenna array, of similar sensitivity to a single JRO receive module, was constructed and operated at Carapongo, approximately 5 kilometers geomagnetically south of JRO. The JRO main array was used for transmission. Receiving was done using sub‐arrays at JRO and with the array at Carapongo. The results provide new insights not only into the aspect sensitivity of RSTEs but also into the physical structure of the plasma giving rise to these echoes. These observations also establish a firmer basis for the modeling of the plasma processes that cause meteor trails to become field‐aligned.
Foam effect on the sea surface emissivity in the 8–14 μm region
Authors: Niclòs Raquel , Caselles Vicente , Valor Enric , Coll César
Published: December 2007

The effect of foam on the sea surface emission has been studied in the microwave region, but its effect on thermal infrared emissivity and temperature has not been sufficiently analyzed in the literature. This paper presents thermal infrared measurements of foam‐covered seawaters carried out under controlled conditions using a multichannel radiometer working in the 8–14 μm region. The experimental data show a negligible foam effect at low observation angles but a significant increase of emissivity with foam at angles above 45°. Differences between foam and foam‐free emissivities are about +0.04 for observation angles of 65°, depending slightly on the radiometric spectral band. The effect of foam is to reduce the angular variation of seawater emissivity. The foam and foam‐free emissivity differences yield to differences up to 2.5 K in terms of sea surface temperature (SST), even larger than 1.2 K when the SST is retrieved from satellite using a split window technique. The correction of the foam effect on emissivity could be performed using an estimate of the fraction of sea covered by foam. This correction could improve the SST retrieval, mainly for measurements at large observation angles.