bluuebunny/crossref_metadata_2025 huggingface dataset:
ERCC5/XPG, ERCC1, and BRCA1 gene status and clinical benefit of trabectedin in patients with soft tissue sarcoma
Authors: Italiano Antoine , Laurand Armelle , Laroche Audrey , Casali Paolo , Sanfilippo Roberta , Le Cesne Axel , Judson Ian , Blay Jean‐Yves , Ray‐Coquard Isabelle , Bui Binh , Coindre Jean‐Michel , Nieto Antonio , Tercero Juan‐Carlos , Jimeno Jose , Robert Jacques , Pourquier Philippe
Published: February 2011

BACKGROUND:

The objective of this study was to determine whether specific single nucleotide polymorphisms (SNPs) from nucleotide excision repair (NER) and homologous recombination (HR) DNA repair pathways are associated with sensitivity to trabectedin in patients with soft tissue sarcoma (STS).

METHODS:

The authors analyzed excision repair cross‐complementation group 5/xeroderma pigmentosum group G (ERCC5/XPG) (NER), excision repair cross‐complementation group 1 (ERCC1) (NER), and breast cancer 1 (BRCA1) (HR) SNPs and messenger RNA expression levels in tumor specimens from 113 patients with advanced STS who were enrolled in previously published phase 2 trials or in a compassionate‐use program. The 6‐month progression‐free rate (PFR), progression‐free survival (PFS), and overall survival (OS) were analyzed according to ERCC5, ERCC1, and BRCA1 status using log‐rank tests.

RESULTS:

High expression of the common allele (aspartic acid at codon 1104) of ERCC5, high expression of ERCC1, and BRCA1 haplotype were associated significantly with improved PFR, PFS, and OS. The ERCC1 thymine‐to‐cytosine (T→C) SNP at codon 19007 and BRCA1 expression were not associated with outcome. On univariate analysis, tumor histology, favorable NER status (high expression of common ERCC5 and/or high ERCC1 expression status), and favorable BRCA1 haplotype (at least 1 triple‐adenine plus guanine [AAAG] allele) were the sole variables associated significantly with PFS and OS.

CONCLUSIONS:

In the current study, ERCC5, ERCC1, and BRCA1 status represented a potential DNA repair signature that could be used for the prediction of clinical response to trabectedin in patients with STS. Cancer 2011. © 2011 American Cancer Society.
Trends in the use of implantable accelerated partial breast irradiation therapy for early stage breast cancer in the United States
Authors: Abbott Andrea M. , Habermann Elizabeth B. , Tuttle Todd M.
Published: February 2011

BACKGROUND:

In 2002, the US Food and Drug Administration approved an implantable balloon catheter that delivers accelerated partial breast irradiation (APBI) after breast‐conserving surgery (BCS). The objective of the current study was to determine the use of implantable APBI (IAPBI) in the United States and factors associated with IAPBI use.

METHODS:

By using the Surveillance, Epidemiology, and End Results database, the authors conducted a retrospective analysis of patients who received whole‐breast radiotherapy (WBRT) or IAPBI after BCS for ductal carcinoma in situ, AJCC stage I, or stage II breast cancer from 2000 to 2007. WBRT and IAPBI rates were determined across time and demographic and tumor factors using chi‐square tests and Cochran‐Armitage tests for trend for the unadjusted analyses.

RESULTS:

A total of 127,257 patients who met inclusion criteria were identified. Over the study period, the proportion of patients receiving IAPBI increased by 1600% (from 0.4% in 2000 to 6.8% in 2007; P <.001). This trend remained significant when using logistic regression (odds ratio, 20.3; 95% confidence interval, 15.5‐26.6). The increase in IAPBI use was statistically significant across all stage and age categories >40 years (P <.001). The use of IAPBI was most notable in older women (ages 70‐79 years), with a >2100% increase in use noted during the study period (0.4% in 2000 vs 9.0% in 2007; P <.001). The authors also found significant variation in IAPBI use by region.

CONCLUSIONS:

IAPBI use has markedly increased since 2000, particularly in the elderly population. The rapid and widespread adoption of IAPBI is concerning, because large multicenter randomized controlled trials have not yet demonstrated the long‐term effectiveness of IAPBI compared with WBRT. Cancer 2011. © 2011 American Cancer Society.
Progression‐free survival as a surrogate marker of overall survival
Authors: Escudier Bernard
Published: February 2011

The use of progression‐free survival as a surrogate marker of efficacy in cancer treatment has been the subject of much discussion in recent years. However, it should not be considered a surrogate marker for overall survival.
TTF‐1 and Napsin A double stain
Authors: Fatima Nazneen , Cohen Cynthia , Lawson Diane , Siddiqui Momin T.
Published: February 2011

BACKGROUND:

Immunohistochemistry (IHC) for thyroid transcription factor‐1 (TTF‐1) is used to confirm the diagnosis of lung adenocarcinoma. Napsin A also has shown positivity in lung adenocarcinoma. A combined double stain for TTF‐1 and napsin A has been proposed to achieve higher sensitivity and specificity. In this study, the authors evaluated the utility of this double stain in the diagnosis of lung adenocarcinoma in cell blocks of fine‐needle aspirates (FNA).

METHODS:

The authors used a cohort comprising 35 FNA cell blocks of lung adenocarcinoma and 24 FNA cell blocks of lung squamous cell carcinoma (SqCCA). IHC was performed; expressions of TTF‐1 as brown nuclear stain and of napsin A as red cytoplasmic stain were identified.

RESULTS:

Twenty‐six of 35 (74%) lung adenocarcinomas were positive for double staining with TTF‐1/napsin A. Of 35 lung adenocarcinomas, only 2 (5%) were positive for TTF‐1 alone and 3 (8%) were positive for napsin A alone. For the double stain TTF‐1/napsin A, 3 of 24 (12%) lung SqCCAs were positive for both. Six of 24 (25%) cases were positive for TTF‐1 alone, and none were positive for napsin A alone. For lung adenocarcinoma, TTF‐1/napsin A has a sensitivity of 74%, specificity of 87%, accuracy of 79%, and a positive predictive value of 89%.

CONCLUSIONS:

The double IHC stain, TTF‐1/napsin A, for the identification of pulmonary adenocarcinoma in FNA cell block materials was diagnostically useful. The use of napsin A alone demonstrated a greater degree of accuracy and appeared diagnostically useful as a single IHC stain. Cancer (Cancer Cytopathol) 2011. © 2011 American Cancer Society.
Action functional and quasi‐potential for the burgers equation in a bounded interval
Authors: Bertini Lorenzo , De Sole Alberto , Gabrielli Davide , Jona‐Lasinio Giovanni , Landim Claudio
Published: February 2011

Consider the viscous Burgers equation ut + f(u)x = εuxx on the interval [0,1] with the inhomogeneous Dirichlet boundary conditions u(t,0) = ρ0, u(t,1) = ρ1. The flux f is the function f(u) = u(1 − u), ε > 0 is the viscosity, and the boundary data satisfy 0 < ρ0 < ρ1 < 1. We examine the quasi‐potential corresponding to an action functional arising from nonequilibrium statistical mechanical models associated with the above equation. We provide a static variational formula for the quasi‐potential and characterize the optimal paths for the dynamical problem. In contrast with previous cases, for small enough viscosity, the variational problem defining the quasi‐potential admits more than one minimizer. This phenomenon is interpreted as a nonequilibrium phase transition and corresponds to points where the superdifferential of the quasi‐potential is not a singleton. © 2011 Wiley Periodicals, Inc.
Sweeping preconditioner for the Helmholtz equation: Hierarchical matrix representation
Authors: Engquist Björn , Ying Lexing
Published: February 2011

The paper introduces the sweeping preconditioner, which is highly efficient for iterative solutions of the variable‐coefficient Helmholtz equation including very‐high‐frequency problems. The first central idea of this novel approach is to construct an approximate factorization of the discretized Helmholtz equation by sweeping the domain layer by layer, starting from an absorbing layer or boundary condition. Given this specific order of factorization, the second central idea is to represent the intermediate matrices in the hierarchical matrix framework. In two dimensions, both the construction and the application of the preconditioners are of linear complexity. The generalized minimal residual method (GMRES) solver with the resulting preconditioner converges in an amazingly small number of iterations, which is essentially independent of the number of unknowns. This approach is also extended to the three‐dimensional case with some success. Numerical results are provided in both two and three dimensions to demonstrate the efficiency of this new approach. © 2011 Wiley Periodicals, Inc.
“Zero” temperature stochastic 3D ising model and dimer covering fluctuations: A first step towards interface mean curvature motion
Authors: Caputo Pietro , Martinelli Fabio , Simenhaus François , Toninelli Fabio Lucio
Published: February 2011

We consider the Glauber dynamics for the Ising model with “+” boundary conditions, at zero temperature or at a temperature that goes to zero with the system size (hence the quotation marks in the title). In dimensiond= 3 we prove that an initial domain of linear sizeLof “−” spins disappears within a time τ+, which is at mostL2(logL)cand at leastL2/(clogL) for somec> 0. The proof of the upper bound proceeds via comparison with an auxiliary dynamics which mimics the motion by mean curvature that is expected to describe, on large time scales, the evolution of the interface between “+” and “−” domains. The analysis of the auxiliary dynamics requires recent results on the fluctuations of the height function associated to dimmer coverings of the infinite honeycomb lattice. Our result, apart from the spurious logarithmic factors, is the first rigorous confirmation of the Lifshitz law τ+≃ const ×L2, conjectured on heuristic grounds [8, 13]. In dimensiond= 2, τ+can be shown to be of orderL2without logarithmic corrections: the upper bound was proven in [6], and here we provide the lower bound. Ford= 2, we also prove that the spectral gap of the generator behaves like${ c \over L}$forLlarge, as conjectured in [2]. © 2011 Wiley Periodicals, Inc.
A survey on software checkpointing and mobility techniques in distributed systems
Authors: Marzouk Soumaya , Jmaiel Mohamed
Published: February 2011

This paper has two purposes. First, it shows that existing solutions employing checkpointing and mobility in distributed applications, fix, at design time, the types and the techniques of checkpointing and mobility to be employed at runtime. Second, it provides policies allowing the dynamic selection of checkpointing and mobility techniques according to the execution environment. For that, this paper presents checkpointing and mobility techniques to evaluate them in order to identify their advantages and their shortcomings, and then determine the appropriate execution conditions in which a specific mobility technique becomes beneficial. This investigation will allow in assisting adaptation plans' generation and promoting future research in the area of self‐adaptivity of distributed applications. Copyright © 2011 John Wiley & Sons, Ltd.
Performance analysis of dual switched diversity over correlated Weibull fading channels with co‐channel interference
Authors: Cvetkovic Aleksandra M. , Djordjevic Goran T. , Stefanovic Mihajlo C.
Published: February 2011

This paper studies the performance of switch and stay combining (SSC) diversity in the presence of co‐channel interference over correlated Weibull fading channels. SSC diversity based on signal‐to‐interference ratio (SIR) is a low‐complexity and a very efficient technique that reduces fading and co‐channel interference influence. New closed‐form expressions for the probability density function and cumulative distribution function of the output SIR's are derived. These formulas are used in a detailed analysis of the average output SIR and outage probability. The influence of fading severity and correlation coefficient on the optimum switching threshold and system performance is investigated. Monte Carlo simulations are performed to verify obtained theoretical results and determine average bit error rate in detecting binary phase‐shift keying (BPSK), differential BPSK and quadrature amplitude modulation signals. Copyright © 2011 John Wiley & Sons, Ltd.
A hidden mutual authentication protocol for low‐cost RFID tags
Authors: Li Jung‐Shian , Liu Kun‐Hsuan
Published: February 2011

Radio‐frequency identification (RFID) technology enables the identification and tracking of objects by means of the wireless signals emitted by a tag attached to the objects of interest. Without adequate protection, however, malicious attackers can easily eavesdrop, scan or forge the information within the tag, thereby threatening the integrity of the system. Previous research has shown that the basic security requirements of RFID systems, i.e. identity authentication, information privacy and location privacy, can be satisfied using conventional cryptographic components. However, such components are expensive, and therefore conflict with the general requirement for low‐cost tag designs. Accordingly, this paper presents a low‐cost challenge‐response security protocol designated as the hidden mutual authentication protocol (HMAP) to accomplish both a mutual authentication capability between the tag and the reader and information privacy. The results show that HMAP provides an efficient means of concealing the authentication messages exchanged between the tag and the reader and is robust toward replay attacks. In addition, it is shown that HMAP is easily extended to provide complete location privacy by utilizing a hash function to generate different tag identifiers in each authentication session. Copyright © 2011 John Wiley & Sons, Ltd.
Contributions of dysglycaemia, obesity, and insulin resistance to impaired endothelium‐dependent vasodilation in humans
Authors: Han K. A. , Patel Y. , Lteif A. A. , Chisholm R. , Mather Kieren J.
Published: February 2011

Background

Individual effects of hyperglycaemia and obesity to impair vascular health are recognized. However, the relative contributions of dysglycaemia versus other obesity‐related traits to vascular dysfunction have not been systematically evaluated.

Methods

We undertook a cross‐sectional evaluation of factors contributing to vascular function in 271 consecutive subjects, categorized as non‐obese normal glucose tolerant (n = 115), non‐obese dysglycaemic (n = 32), obese normal glucose tolerant (n = 57), obese dysglycaemic (n = 38), or type 2 diabetic (n = 29). Vascular function was measured invasively as leg blood flow responses to methacholine chloride, an endothelium‐dependent vasodilator. Categorical and continuous analyses were carried out to assess the contributions of hyperglycaemia to vascular dysfunction.

Results

Even among normoglycaemic subjects, obese subjects had impaired vascular function compared to non‐obese subjects (p = 0.004). Vascular function was also impaired in non‐obese dysglycaemic subjects (p = 0.04 versus non‐obese normoglycaemic subjects), to a level comparable to normoglycaemic obese subjects. Within obese subject groups, gradations of dysglycaemia including the presence of diabetes were not associated with further worsening of these vascular responses beyond the effect of obesity alone (p = not significant comparing all obese groups, p < 0.001 versus lean normoglycaemic subjects). After univariate and multivariable modelling analyses we found that effects of glycaemia were less powerful than effects of insulin resistance and obesity on vascular dysfunction.

Conclusions

Dysglycaemia contributes to impaired vascular function in non‐obese subjects, but obesity and insulin resistance are more important determinants of vascular function in obese and diabetic subjects. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of insulin and oral anti‐diabetic agents on glucose metabolism, vascular dysfunction and skeletal muscle inflammation in type 2 diabetic subjects
Authors: Joya‐Galeana J. , Fernandez M. , Cervera A. , Reyna S. , Ghosh S. , Triplitt C. , Musi N. , DeFronzo R. A. , Cersosimo E.
Published: February 2011

Background

To test potential differences between the actions of anti‐diabetic medications, we examined the effects of oral hypoglycaemic agents versus glargine–apidra insulin therapy in T2DM.

Methods

T2DM subjects were randomized to either oral hypoglycaemic agents (pioglitazone, metformin and glipizide, n = 9) or insulin therapy (n = 12) for 6 months. Carotid intimal media thickness, vascular reactivity (flow‐mediated vasodilatation; percent change in brachial artery basal diameter post‐ischaemia) and sublingual nitrate were measured with ultrasonography. Euglycemic hyperinsulinemic (80 mU/m2) clamp with [3]‐3H‐glucose and muscle biopsies were performed.

Results

Fasting plasma glucose (∼257 to ∼124 mg/dL, oral hypoglycaemic agents and ∼256 to ∼142 mg/dL, IT) and HbA1c (∼10.3 to ∼6.4%, OHA and ∼10.7 to ∼7.1%, IT) improved comparably. Endogenous glucose production (∼2.1 to ∼1.7 mg/kg/min, oral hypoglycaemic agents and ∼2.3 to ∼2.0 mg/kg/min, insulin therapy) and endogenous glucose production suppression by insulin (∼0.4 to ∼0.3 mg/kg min, oral hypoglycaemic agents and ∼0.5 to ∼0.7 mg/kg min, insulin therapy) were different. Total glucose disposal × 100 increased in the oral hypoglycaemic agents group (∼5.2 to ∼8.1; p = 0.03), but not in insulin therapy (∼6.0 to ∼5.4 mg/kg/min/µU/mL × 100). OHA reduced CIMT (∼0.080 to ∼0.068 cm; p < 0.05), whereas insulin therapy did not (∼0.075 to ∼0.072 cm). After sublingual nitrate, brachial artery basal diameter increased in the OHA group (∼8.7 to ∼18.2%), but not in insulin therapy (∼11.2 to ∼15.0%; p < 0.02). Except for plasma adiponectin (∼7 to ∼15, oral hypoglycaemic agents versus ∼6 to ∼10, IT), changes in inflammatory markers in the circulation and in muscle (IκBα, super‐oxidase dismutase 2, monocyte‐chemo‐attractant protein 1, p‐ERK and JNK) were equivalent.

Conclusions

Oral hypoglycaemic agents and insulin therapy treated patients achieved adequate glycemic control and the effects on circulating and muscle inflammatory biomarkers were similar, but only oral hypoglycaemic agents improved insulin sensitivity, vascular function and carotid intimal media thickness. These findings in a small sample suggest that the use of oral hypoglycaemic agents provides additional benefits to patients with T2DM. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamic expression of two thrombospondins during axolotl limb regeneration
Authors: Whited Jessica L. , Lehoczky Jessica A. , Austin Christina A. , Tabin Clifford J.
Published: February 2011

The molecular processes underlying regeneration remain largely unknown. Several potential factors have been elucidated by focusing on the regenerative function of genes originally identified in a developmental context. A complementary approach is to consider the roles of factors involved in wound healing. Here we focus on the Thrombospondins, a family of secreted extracellular matrix proteins that have been implicated in skin wound healing in mammals. We show that a subset of Thrombospondins are expressed at distinct times and in particular cell types during axolotl limb regeneration. Our studies have revealed the axolotl orthologs of thrombospondin‐1 (tsp‐1) and thrombospondin‐4 (tsp‐4) are highly upregulated during limb regeneration in patterns both distinct and similar to larval limb development. Our data suggest that thrombospondins may be key regulators of limb regeneration in axolotl, while their activation appears to be relegated solely to wound healing in vertebrates that have lost the ability to regenerate limbs. Developmental Dynamics 240:1249–1258, 2011. © 2011 Wiley‐Liss, Inc.
Signal Processing in Electrochemistry
Authors: Jakubowska Małgorzata
Published: February 2011

This review presents and promotes preprocessing methods applied in electrochemistry prior to data exploration, calibration and classification. Smoothing by digital filtering, baseline correction, separation of overlapping signals, and also transformations to extract the relevant features of the curve are the algorithms of which the application, operation, and optimization of parameters are described. The presentation completes the description of the procedure enabling orthogonal correction of the signals. The theoretical consideration is demonstrated by examples of the practical application of the described algorithms in electrochemistry in recent years. Software packages useful in signal processing in electrochemistry are also listed. The paper underlines the point that particular methods show the different effects of signal processing and in the case of the improper selection of the algorithm or its parameters, undesirable distortions of the curves may be observed. Therefore a knowledge of signal processing methodology is necessary before its application.
Simultaneous Determination of Antimony and Lead in Gunshot Residue by Cathodic Adsorptive Stripping Voltammetric Methods
Authors: Erden Sevcan , Durmus Zehra , Kılıç Esma
Published: February 2011

Differential pulse cathodic adsorptive stripping (DPCAdSV) and square wave cathodic adsorptive stripping (SWCAdSV) voltammetric methods were developed for the determination of antimony and lead in gunshot residues. Linear working ranges for DPCAdSV and SWCAdSV methods were (2.0×10−9–5.0×10−7) M and (2.0×10−9–7.0×10−7) M for antimony and 2.0×10−9–3.0×10−7 M (both methods) for lead. The detection of antimony limits were found to be 1.3×10−9 M for DPCAdSV and 7.3×10−10 M for SWCAdSV while the corresponding values for lead were 3.0×10−9 M and 5.8×10−10 M. Antimony and lead contents obtained by these methods in gunshot residues are in good agreement with those obtained by graphite furnace atomic absorption spectrometric method within a confidence limit of 95%.
Enzyme Logic Gates Based on Enzyme‐Coated Carbon Nanotubes
Authors: Kim Kyung‐Woo , Kim Byung Chan , Lee Hye Jin , Kim Jungbae , Oh Min‐Kyu
Published: February 2011

Enzyme‐based Boolean logic gates were developed by using highly stable enzyme precipitate coatings (EPCs) on carbon nanotubes (CNTs). EPCs of three enzymes, glucose oxidase (GOx), horseradish peroxidase (HRP), and invertase (INV), were prepared in a three‐step process that consists of covalent enzyme attachment, enzyme precipitation, and enzyme crosslinking. The AND logic gate was formulated based on an ON output signal in response to the combined inputs of glucose and dye. The OR logic gate was based on the ON output signal of glucose oxidation in the presence of EPC‐GOx and EPC‐INV with one of the two inputs, either glucose or sucrose. The use of EPCs will provide an effective tool for the development of sensitive and repeatedly‐usable Boolean logic gates with a long lifetime, which can be employed in various biosignaling systems.
Electrochemical Detection with Platinum Decorated Carbon Nanomaterials
Authors: Tang Yifan , Kotchey Gregg P. , Vedala Harindra , Star Alexander
Published: February 2011

Here we performed amperometric detection of hydrogen peroxide (H2O2) using single‐walled carbon nanotubes (SWNTs), chemically converted graphene (CCG), and sulfonated CCG (CCG‐S) decorated with Pt nanoparticles (NPs). Although all three systems demonstrated similar detection limits for H2O2, compared to the other two nanomaterials, Pt‐SWNTs provided a higher sensitivity with only half of the Pt amount. This result was consistent with cyclic voltammetry, electrochemical impedance spectroscopy, and field‐effect transistor measurements. We attribute the higher sensitivity of Pt‐SWNTs to both the surface roughness of the electrode and the intimate contact between Pt NPs and one‐dimensional nanostructures (SWNTs) versus two‐dimensional nanostructures (graphene).
Pesticide and toxicity reduction using an integrated vegetated treatment system
Authors: Anderson Brian , Phillips Bryn , Hunt John , Largay Bryan , Shihadeh Rami , Tjeerdema Ronald
Published: February 2011

The California, USA, central coast is one of the most productive agricultural areas in the world, and numerous stakeholders are working there to implement conservation practices to reduce contaminated runoff. Practices include vegetated treatment systems (VTS) designed to promote contaminant reduction and breakdown. The current study evaluated the effectiveness of a vegetated drainage ditch incorporating a sedimentation basin, a vegetated section, and a Landguard organophosphate-A (OP-A) enzyme dosing system. The VTS was constructed on a working farm and was designed to remove organophosphate and pyrethroid pesticides, the primary pesticides causing toxicity in Salinas Valley watersheds. The present study was conducted during five separate irrigation events on tailwater runoff containing mixtures of pesticides and suspended sediments. Water samples were collected at four stations within the system, and these were subjected to chemical analyses and tested for toxicity to Ceriodaphnia dubia. All inflow samples were highly toxic to C. dubia, and this was largely because of diazinon. Treatment of diazinon-contaminated runoff was only partially effective using aquatic vegetation. All diazinon remaining after vegetated treatment was effectively removed after treatment with the Landguard OP-A enzyme. Chemical analysis of the VTS water samples showed that pyrethroid and organochlorine pesticide concentrations in water were greatly reduced in the sedimentation section of the ditch, and these pesticides were further reduced in the vegetated section of the ditch. The overall conclusion from these analyses is that the VTS was effective at reducing the more hydrophobic organochlorine and pyrethroid pesticides from water. The water-soluble pesticide diazinon was not sufficiently removed during the VTS residence times observed in this study; however, residual diazinon was effectively removed using Landguard OP-A. Environ. Toxicol. Chem. 2011; 30:1036–1043. © 2011 SETAC
Proteomics in aquatic amphipods: Can it be used to determine mechanisms of toxicity and interspecies responses after exposure to atrazine?
Authors: Ralston-Hooper Kimberly J , Sanchez Brian C , Adamec Jiri , Sepúlveda María S
Published: February 2011

Proteomics has gained popularity in the field of ecotoxicology as a holistic tool for unraveling novel mechanisms of toxicity and elucidating subtle effects of contaminant exposure. The holoarctic amphipod Diporeia spp. is declining at precipitous rates in the Great Lakes, and we are evaluating the use of the well-studied amphipod model Hyalella azteca as a surrogate for Diporeia spp. This article presents proteomics data from both amphipod species exposed to atrazine (ATZ) and one of its metabolites, desethylatrazine (DEA; 3 and 30 µg/L for 21 and 42 d). We used a proteomics approach to determine whether these two species of amphipods responded similarly to the same chemicals and to understand better the mechanisms of toxicity of ATZ and DEA in aquatic invertebrates. We observed disruption in energy production and mitochondrial function as well as hormesis in exposed organisms. In addition, we identified a two proteins (GAPDH and HSP 90 kDa) that have been linked to hormonal disruptions, suggesting potential endocrine disruption. Finally, we found that H. azteca and Diporeia spp. responded with similar proteomic profiles after ATZ and DEA exposure, suggesting that H. azteca may be used as a surrogate model organism for Diporeia spp. Environ. Toxicol. Chem. 2011; 30:1197–1203. © 2011 SETAC
Bacterial gene profiling assay applied as an alternative method for mode of action classification: Pilot study using chlorinated anilines
Authors: Dom Nathalie , Nobels Ingrid , Knapen Dries , Blust Ronny
Published: February 2011

Polar narcotic structural analogues (e.g., chlorinated anilines with a differing degree of chlorosubstitution, such as aniline, 4-chloroaniline, 3,5-dichloroaniline, and 2,3,4-trichloroaniline) are assumed to induce their toxic effects via the same predominant mode of action (MOA; membrane damage) at equitoxic exposure concentrations. In this study, a bacterial gene profiling assay consisting of 14 general stress genes was used to test this hypothesis for these four compounds. Although we found a consistent induction of membrane damage, the response cascade and the extent of the response differed among the different chemical treatments. The higher chlorosubstituted anilines also triggered significantly more genes involved in other general stress MOA classes (oxidative stress and protein perturbation). These findings illustrate that, along with the commonly used physicochemistry-based MOA categorization methods, alternative tests such as the bacterial gene profiling assay can yield valuable biological information on the MOA of a certain chemical or group of chemicals that is crucial in high-quality environmental risk assessment. In a second phase, the experimental gene profiling data sets of the chlorinated anilines were analyzed and weighed against existing data on other polar and non polar narcotic compounds to obtain a broader comparison in which the predefined chemical MOAs (narcosis and polar narcosis) were contrasted with the biological MOAs (gene expression profiles). Although additional optimization of the assay is needed, our results show that the bacterial gene profiling assay opens new perspectives for biology-based chemical grouping, thereby further enabling targeted MOA-based risk assessment. Environ. Toxicol. Chem. 2011; 30:1059–1068. © 2011 SETAC
Dissolution and Migration of Platinum in PEMFCs Investigated for Start/Stop Cycling and High Potential Degradation
Authors: Ettingshausen F. , Kleemann J. , Marcu A. , Toth G. , Fuess H. , Roth C.
Published: February 2011

Dissolution and migration of platinum due to start/stop degradation and increased cathode potentials were studied for commercial membrane electrode assemblies (MEA). The chosen conditions closely mimic real situations in automotive operation. In start/stop tests, we observed a strongly enhanced platinum dissolution due to the dynamic interplay of repeated cell start‐up and consecutive normal fuel cell operation, which is related to platinum oxidation (start‐up) and reduction (normal operation) cycles. Consequently, the performed test protocols distinguish between dynamic and static load profiles. Electrochemical investigations before and after degradation monitor the loss in cell performance. Since electron microscopy offers the unique possibility to unravel and distinguish degradation due to carbon corrosion and agglomeration or platinum dissolution, a focus was set on this method. For the start/stop MEA pronounced platinum dissolution accompanied by the formation of large platinum precipitations in the membrane was found. Carbon corrosion was also observed, but did not lead to a significantly reduced porosity and loss in platinum dispersion. In contrast, the MEA which was exposed to high constant potentials exhibited severe damage to the 3D cathode structure due to carbon corrosion. However, no pronounced platinum dissolution was observed and only few Pt precipitations were found in the membrane itself.
Raman Spectroscopic Mapping of the Carbon and PTFE Distribution in Gas Diffusion Layers
Authors: Mendoza A. J. , Hickner M. A. , Morgan J. , Rutter K. , Legzdins C.
Published: February 2011

Raman microspectroscopy was used to gather spatially resolved chemical information on the carbon and poly(tetrafluoroethylene) (PTFE) distribution of fuel cell gas diffusion layers (GDL). GDLs with varying PTFE content were imaged over areas of 1,000 μm × 1,000 μm and it was found that the distribution of concentrated PTFE regions on the surface of the GDLs and morphology of the carbon fibre paper was readily observed. Spectroscopic measurements with point‐by‐point resolutions varying between 10 and 500 μm were performed on samples having 1.8–44 wt.% PTFE before and after the PTFE was sintered. The average PTFE signal detected on the surface of the GDLs increased monotonically for both unsintered and sintered GDLs with increasing bulk PTFE loading. The unsintered GDLs had higher PTFE signals on their surface compared to sintered GDLs and showed more concentrated PTFE regions in the mapping experiments.
A Two‐dimensional Network Study on Oxygen Transport in Porous Gas Diffusion Layer
Authors: Wu R. , Liao Q. , Zhu X. , Wang H. , Ding Y.‐d. , Li J. , Ye D.‐d.
Published: February 2011

Oxygen transport in the porous gas diffusion layer (GDL), which is generally characterised by the oxygen effective diffusivity, is of great importance for the performance of proton exchange membrane fuel cells (PEMFCs). The determination of the oxygen effective diffusivity is challenging due to the complex structure of the porous GDL samples. In the present study, a two‐dimensional network consisting of arms and nodes is adopted to illustrate how oxygen effective diffusivity is affected by the GDL structure under the condition with/without water invasion. Water permeation in the network is simulated using the invasion percolation algorithm and oxygen transport in the arms is described by Fick's law. The simulation results reveal that oxygen effective diffusivity under dry condition decreases with increase in the network heterogeneity. With water permeation, the oxygen effective diffusivity goes to zero even though water saturation is rather less than unity. The critical water saturation, above which the oxygen effective diffusivity becomes zero, is found to decrease with increasing heterogeneity. To enhance oxygen transport, four different modified networks are introduced in the present study. It is found that the network with large arms in oxygen transport direction has the best oxygen and water transport properties.
Microscale Modeling of an Anode‐Supported Planar Solid Oxide Fuel Cell
Authors: Chinda P. , Wechsatol W. , Chanchaona S. , Brault P.
Published: February 2011

A microscale model of a solid oxide fuel cell (SOFC) involving the mass transfer together with the electrochemical reaction, the transportation of electrons and ions through the respective spherical shaped electron conducting and ion conducting particles inside the electrodes was mathematically developed. Couples of useful parameters were introduced in order to represent the characteristics of the cell. The predicted cell performance was showed according to various operating and design conditions. The effects of microscale electrode geometry on the cell performance were also taken into account. Parametric study according to the volumetric fraction of ionic and electronic conducting particles was conducted in order to examine the effects of operating conditions on the cell overpotentials. The study results substantiate the fact that SOFC overpotential could be effectively decreased by increasing the operating temperature as well as operating pressure. This present study reveals the working mechanisms of SOFC at the microscale level, while demonstrating the use of microscale relations to enhance the SOFC performance. The accuracy of the presented model was validated by comparing with already existing experimental results from the available literatures.
Prevalence and risk factors for depression in older people in Xi′an China: a community‐based study
Authors: Yunming Li , Changsheng Chen , Haibo Tu , Wenjun Cao , Shanhong Fan , Yan Ma , Yongyong Xu , Qianzhen Hua
Published: February 2011

Objective

To estimate the prevalence of depressive symptoms and to determine the impact of socio‐demographic variables, chronic diseases and health‐related events on depression in a community sample of older adults in Xi′an, Shaanxi Province.

Methods

Cross sectional, multistage community survey. A semi‐structured questionnaire including socio‐demographic characteristics, physical health, chronic diseases and health‐related events was administered to 1587 older adults from eight communities. Depression was assessed using the 30‐item Geriatric Depression Scale (GDS) with a threshold of <11/11+. Analysis was conducted using SPSS16.0 Complex Samples Logistic analysis procedure.

Results

The prevalence of depression was 27.0% (95% CI 24.7–29.2%). In a univariate analysis, the following variables were significantly associated with depression: female gender, low max income, coronary heart disease, suffering 3 or above chronic diseases and functional impairments, 4 adverse life events (financial problems, death of closely related person, unpleasantness experience and horrifying experience) and suffering 1 or above adverse life events. After adjustment for age and gender, odds ratios for depression were significantly higher for coronary heart disease, suffering 3 or above chronic diseases and functional impairments, adverse life event (financial problems, unpleasantness experience) and suffering 3 or above adverse life events.

Conclusions

According to GDS estimates, 27.0% Chinese urban older adult had depression symptoms. In designing prevention programs, detection and management of older patients with depression should be a high priority in developing countries. Copyright © 2011 John Wiley & Sons, Ltd.
Spatial variability and temporal stability of throughfall in a eucalyptus plantation in the hilly lowlands of southeastern Brazil
Authors: Mululo Sato Anderson , de Souza Avelar André , Coelho Netto Ana Luiza
Published: February 2011

Throughfall has been widely studied in forests but there is a scarcity of studies that focus on the spatial variability and temporal stability of throughfall in eucalyptus plantations. We examined throughfall in a daily basis in a 2·5‐year eucalyptus plantation in southeastern Brazil using three sample arrangements: (1) close to tree trunks (CT) and in the central point between trunks (BT), (2) four‐radial layout centred in tree trunk and (3) eight‐radial layout. Throughfall was spatially non‐uniform and varied according to the spatial monitoring arrangement: accumulated throughfall/precipitation ratio of 146% (CT) and 85% (BT) in arrangement 1, mean throughfall of 88% in arrangement 2, 84% (hilltop) and 85% (side slope) in arrangement 3. The highest throughfall values, spatial variability and persistence of dry and wet conditions were found close to eucalyptus trunks. Often accumulated throughfall close to trunks exceeded rainfall, especially for long‐duration rainfall > 5 mm. The ‘funnel effect’ was consistently observed in all three arrangements and we speculate that the high throughfall concentration and temporal stability are related to canopy structures of eucalyptus. Copyright © 2011 John Wiley & Sons, Ltd.
Heat release from rooftops during rainstorms in the Minneapolis/St. Paul Metropolitan Area, USA
Authors: Janke Benjamin D. , Mohseni Omid , Herb William R. , Stefan Heinz G.
Published: February 2011

In the modeling of urban storm water runoff temperatures, the contribution of rooftops to the heating of rainfall runoff is usually neglected or not mentioned in the literature. In this paper we examine the accuracy of this assumption (a) by analyzing temperature data that we recorded on a residential rooftop, a commercial rooftop, and a concrete driveway, and (b) by simulating temperature profiles within rooftops and pavements, and estimating heat transfer amounts from these surfaces to rainfall runoff (‘heat export’). Analysis of both wet‐ and dry‐weather temperature data recorded in the Minneapolis/St. Paul metropolitan area (north‐central USA) over periods of several months leads to the conclusion that (a) a concrete driveway has a far greater capacity for heat storage and release than a shingled residential rooftop, and (b) an insulated commercial rooftop is able to store and release more heat than the residential rooftop. Unexpectedly, the rainfall events with the highest dew point (rainfall) and surface temperatures often occurred during late night or early morning hours, and not during daylight hours. The analysis of three rainfall events showed that the heat export from the commercial rooftop was roughly three times that of the residential rooftop, but only 30%–90% of the heat export from a concrete driveway. Maximum (potential) heat export was significantly higher for the driveway than for either rooftop. In conclusion, the results of the data analysis and heat export simulations support the assumption that residential rooftops contribute very little heating to runoff from rainfall, while commercial rooftops may have a thermal impact on rainfall runoff because of their greater thermal storage capacity. Commercial rooftops, in addition to asphalt and concrete pavements, should be considered when estimating water temperature of rainfall runoff from urbanized areas and the associated impact on the thermal regime of streams and fish habitat. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative evaluation of different hydrological modelling approaches in a partly glacierized Swiss watershed
Authors: Magnusson Jan , Farinotti Daniel , Jonas Tobias , Bavay Mathias
Published: February 2011

Mountain water resources management often requires hydrological models that need to handle both snow and ice melt. In this study, we compared two different model types for a partly glacierized watershed in central Switzerland: (1) an energy‐balance model primarily designed for snow simulations; and (2) a temperature‐index model developed for glacier simulations. The models were forced with data extrapolated from long‐term measurement records to mimic the typical input data situation for climate change assessments. By using different methods to distribute precipitation, we also assessed how various snow cover patterns influenced the modelled runoff.

The energy‐balance model provided accurate discharge estimations during periods dominated by snow melt, but dropped in performance during the glacier ablation season. The glacier melt rates were sensitive to the modelled snow cover patterns and to the parameterization of turbulent heat fluxes. In contrast, the temperature‐index model poorly reproduced snow melt runoff, but provided accurate discharge estimations during the periods dominated by glacier ablation, almost independently of the method used to distribute precipitation. Apparently, the calibration of this model compensated for the inaccurate precipitation input with biased parameters.

Our results show that accurate estimates of snow cover patterns are needed either to correctly constrain the melt parameters of the temperature‐index model or to ensure appropriate glacier surface albedos required by the energy‐balance model. Thus, particularly when only distant meteorological stations are available, carefully selected input data and efficient extrapolation methods of meteorological variables improve the reliability of runoff simulations in high alpine watersheds. Copyright © 2011 John Wiley & Sons, Ltd.
Comparative analysis of rating curve and ADP estimates of instantaneous water discharge through estuaries in two contrasting Brazilian rivers
Authors: da Silva Dias Francisco José , Lacerda Luiz Drude , Marins Rozane Valente , de Paula Francisco Carlos Fernandes
Published: February 2011

This work quantifies, using ADP and rating curve techniques, the instantaneous outflows at estuarine interfaces: higher to middle estuary and middle to lower estuary, in two medium‐sized watersheds (72 000 and 66 000 km2 of area, respectively), the Jaguaribe and Contas Rivers located in the northeastern (semi‐arid) and eastern (tropical humid) Brazilian coasts, respectively. Results from ADP showed that the net water balances show the Contas River as a net water exporter, whereas the Jaguaribe River Estuary is a net water importer. At the Jaguaribe Estuary, water retention during flood tide contributes to 58% of the total volume transferred during the ebb tide from the middle to lower estuary. However, 42% of the total water volume (452 m3 s−1) that entered during flood tide is retained in the middle estuary. In the Contas River, 90% of the total water is retained during the flood tide contributing to the volume transported in the ebb tide from the middle to the lower estuary. Outflows obtained with the rating curve method for the Contas and Jaguaribe Rivers were uniform through time due to river flow normalization by dams in both basins. Estimated outflows with this method are about 65% (Contas) and 95% (Jaguaribe) lower compared to outflows obtained with ADP. This suggests that the outflows obtained with the rating curve method underestimate the net water balance in both systems, particularly in the Jaguaribe River under a semi‐arid climate. This underestimation is somewhat decreased due to wetter conditions in the Contas River basin. Copyright © 2011 John Wiley & Sons, Ltd.
Improvement of snowpack simulations in a regional climate model
Authors: Jin Jiming , Miller Norman L.
Published: February 2011

To improve simulations of regional‐scale snow processes and related cold‐season hydroclimate, the Community Land Model version 3 (CLM3), developed by the National Center for Atmospheric Research (NCAR), was coupled with the Pennsylvania State University/NCAR fifth‐generation Mesoscale Model (MM5). CLM3 physically describes the mass and heat transfer within the snowpack using five snow layers that include liquid water and solid ice. The coupled MM5–CLM3 model performance was evaluated for the snowmelt season in the Columbia River Basin in the Pacific Northwestern United States using gridded temperature and precipitation observations, along with station observations. The results from MM5–CLM3 show a significant improvement in the SWE simulation, which has been underestimated in the original version of MM5 coupled with the Noah land‐surface model. One important cause for the underestimated SWE in Noah is its unrealistic land‐surface structure configuration where vegetation, snow and the topsoil layer are blended when snow is present. This study demonstrates the importance of the sheltering effects of the forest canopy on snow surface energy budgets, which is included in CLM3. Such effects are further seen in the simulations of surface air temperature and precipitation in regional weather and climate models such as MM5. In addition, the snow‐season surface albedo overestimated by MM5–Noah is now more accurately predicted by MM5–CLM3 using a more realistic albedo algorithm that intensifies the solar radiation absorption on the land surface, reducing the strong near‐surface cold bias in MM5–Noah. The cold bias is further alleviated due to a slower snowmelt rate in MM5–CLM3 during the early snowmelt stage, which is closer to observations than the comparable components of MM5–Noah. In addition, the over‐predicted precipitation in the Pacific Northwest as shown in MM5–Noah is significantly decreased in MM5–CLM3 due to the lower evaporation resulting from the longer snow duration. Copyright © 2011 John Wiley & Sons, Ltd.
Measurements of rill and gully erosion in Sicily
Authors: Di Stefano Costanza , Ferro Vito
Published: February 2011

This article reports the results of a field investigation aimed to characterize the morphology of both rills monitored at Sparacia experimental area and two ephemeral gullies (EGs) located in the Tremamargi basin, Sicily, Italy. At first, the available literature data together with the measurements carried out in this investigation were used to show that the EG length is a key parameter for the estimation of the eroded volume. Then, the comparison among the pairs length and volume corresponding to measured rills, EGs and gullies showed that the exponent of the power relationship is independent of the channelized erosion type (rill, EG and gully), while a different scale factor has to be used for each erosion process. Finally, a single relationship applicable to all channelized erosion processes was deduced applying the dimensional analysis and the self‐similarity theory. Copyright © 2011 John Wiley & Sons, Ltd.