bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi‐layer interleave‐division multiple access: theory and practice
Authors: Hoeher Peter A. , Schoeneich Hendrik , Fricke Justus Ch.
Published: January 2008

Direct‐sequence code‐division multiple access(DS‐CDMA) is often put on the same level with CDMA, ignoring the fact that many different CDMA techniques exist. A special CDMA technique which has recently become popular isinterleave‐division multiple access(IDMA). In this semi‐tutorial, focus is on a generalisation of IDMA referred to asinterleave‐division multiplexing(IDM)/IDMA ormulti‐layer IDMAfor short. Multi‐layer IDMA is a special form of superposition coding, and can be interpreted as ajoint modulation, channel coding and multiple access scheme. Motivated by information theoretical arguments and practical functionalities, a wide range of subjects (such as capacity bounds, power allocation, receiver analysis, quality of service aspects, multi‐layer ARQ and possible applications) are covered. This semi‐tutorial consists of three parts: in the first part, an introduction to IDMA (Section 1) and multi‐layer IDMA (Section 2) is given. In the second part, practical issues such as functionalities of multi‐layer IDMA (Section 3) and multi‐layer ARQ (Section4) are studied. In the third part, information theoretical bounds in conjunction with power allocation (Section 5) and a receiver analysis (Section 6) are provided, before conclusions are drawn in Section 7. Copyright © 2008 John Wiley & Sons, Ltd.
Estimation of predictive uncertainties in flood wave propagation in a river channel using adjoint sensitivity analysis
Authors: Elhanafy Hossam , Copeland Graham J. M. , Gejadze Igor Yu.
Published: January 2008

This paper applies adjoint sensitivity analysis to flash flood wave propagation in a river channel. A numerical model, based on the St‐Venant equations and the corresponding adjoint equations, determines the sensitivities of predicted water levels to uncertainties in key controls such as inflow hydrograph, channel topography, frictional resistance and infiltration rate. Sensitivities are calculated in terms of a measuring function that quantifies water levels greater than certain safe threshold levels along the channel. The adjoint model has been verified by means of an identical twin experiment. The method is applied to a simulated flash flood in a river channel. The sensitivities to key controls are evaluated and ranked and the effects of individual and combined uncertainties on the predicted flood impact are also quantified. Copyright © 2008 John Wiley & Sons, Ltd.
A Lagrangian vortex method for unbounded flows
Authors: Moussa C. , Carley M. J.
Published: January 2008

A technique is presented for velocity calculations on the highly distorted node distributions typical of those found in Lagrangian vortex methods. The method solves the partial differential equation for streamfunction directly on the nodes, via a sparse, symmetric system of equations that can be solved using standard iterative solvers. When implemented in a triangulated vortex method, the technique gives computation times which scale as N1.23, where N is the number of nodes. The computation scheme is derived for two‐dimensional problems and applied to the prediction of the evolution of perturbed multipolar vortices. Due to the numerical performance of the method, it has been possible to examine such evolution at higher and lower Reynolds numbers than have been considered in published numerical studies. Copyright © 2008 John Wiley & Sons, Ltd.
Gene expression analysis of BCR/ABL1‐dependent transcriptional response reveals enrichment for genes involved in negative feedback regulation
Authors: Håkansson Petra , Nilsson Björn , Andersson Anna , Lassen Carin , Gullberg Urban , Fioretos Thoas
Published: January 2008

Philadelphia (Ph) chromosome‐positive leukemia is characterized by the BCR/ABL1 fusion protein that affects a wide range of signal transduction pathways. The knowledge about its downstream target genes is, however, still quite limited. To identify novel BCR/ABL1‐regulated genes we used global gene expression profiling of several Ph‐positive and Ph‐negative cell lines treated with imatinib. Following imatinib treatment, the Ph‐positive cells showed decreased growth, viability, and reduced phosphorylation of BCR/ABL1 and STAT5. In total, 142 genes were identified as being dependent on BCR/ABL1‐mediated signaling, mainly including genes involved in signal transduction, e.g. the JAK/STAT, MAPK, TGFB, and insulin signaling pathways, and in regulation of metabolism. Interestingly, BCR/ABL1 was found to activate several genes involved in negative feedback regulation (CISH, SOCS2, SOCS3, PIM1, DUSP6, and TNFAIP3), which may act to indirectly suppress the tumor promoting effects exerted by BCR/ABL1. In addition, several genes identified as deregulated upon BCR/ABL1 expression could be assigned to the TGFB and NFkB signaling pathways, as well as to reflect the metabolic adjustments needed for rapidly growing cells. Apart from providing important pathogenetic insights into BCR/ABL1‐mediated leukemogenesis, the present study also provides a number of pathways/individual genes that may provide attractive targets for future development of targeted therapies. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045–2257/suppmat. © 2008 Wiley‐Liss, Inc.
The expression of BIRC5 is correlated with loss of specific chromosomal regions in breast carcinomas
Authors: Boidot Romain , Vegran Frédérique , Jacob Delphine , Chevrier Sandy , Gangneux Nicolas , Taboureau Johann , Oudin Claire , Rainville Vinciane , Mercier Liliane , Lizard‐Nacol Sarab
Published: January 2008

Expression of BIRC5 (survivin), a member of the inhibitor of apoptosis protein (IAP) family, is elevated in fetal tissues and in various human cancers. Mechanisms up‐regulating BIRC5 in cancer are poorly understood. Here, we show that overexpression of BIRC5 induces a high proliferation level in MCF‐7 breast tumor cells. In a population of 191 breast carcinomas, BIRC5 expression is not affected by BIRC5 promoter polymorphism at −31, or BIRC5 gene copy number. However, a significant correlation was found between expression of demethylase (dMTase) and expression of BIRC5. In addition, among 13 chromosomal regions tested for allelic loss [loss of heterozygosity (LOH)], two regions close to D3S1478 and D6S264 were related to BIRC5 expression. In tumors with LOH at D3S1478 and/or D6S264, BIRC5 expression was significantly increased. These regions have been suggested to harbor tumor suppressor genes and/or common fragile sites that may play a role in increasing genetic instability. These results suggest that genes located near D3S1478 and D6S264 might work by inhibiting, directly or indirectly, BIRC5 expression and thus their loss leads to its up‐regulation. In addition, BIRC5 expression may induce breast tumor proliferation by promoting genetic instability. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045‐2257/suppmat. © 2008 Wiley‐Liss, Inc.
Identification of metastasis-related microRNAs in hepatocellular carcinoma
Authors: Budhu Anuradha , Jia Hu-Liang , Forgues Marshonna , Liu Chang-Gong , Goldstein David , Lam Amy , Zanetti Krista A. , Ye Qing-Hai , Qin Lun-Xiu , Croce Carlo M. , Tang Zhao-You , Wang Xin Wei
Published: January 2008

MicroRNAs (miRNAs) have been used as cancer-related biomarkers. Hepatocellular carcinoma (HCC) is an aggressive cancer with a dismal outcome largely due to metastasis and postsurgical recurrence. We investigated whether the expression of certain miRNAs are associated with HCC metastasis. We examined the miRNA expression profiles of 482 cancerous and noncancerous specimens from radical resection of 241 patients with HCC. Using a supervised algorithm and a clinically well-defined cohort of 131 cases, we built a unique 20-miRNA metastasis signature that could significantly predict (

P

< 0.001) primary HCC tissues with venous metastases from metastasis-free solitary tumors with 10-fold cross-validation. However, significant miRNAs could not be identified from the corresponding noncancerous hepatic tissues. A survival risk prediction analysis revealed that a majority of the metastasis-related miRNAs were associated with survival. Furthermore, the 20-miRNA tumor signature was validated in 110 additional cases as a significant independent predictor of survival (

P

= 0.009) and was significantly associated with both survival and relapse in 89 cases of early stage HCC (

P

= 0.022 and 0.002, respectively). These 20 miRNAs may provide a simple profiling method to assist in identifying patients with HCC who are likely to develop metastases/recurrence. In addition, functional analysis of these miRNAs may enhance our biological understanding of HCC metastasis.
Genipin‐induced changes in collagen gels: Correlation of mechanical properties to fluorescence
Authors: Sundararaghavan Harini G. , Monteiro Gary A. , Lapin Norman A. , Chabal Yves J. , Miksan Jennifer R. , Shreiber David I.
Published: January 2008

Controlled crosslinking of collagen gels has important applications in cell and tissue mechanics as well as tissue engineering. Genipin is a natural plant extract that has been shown to crosslink biological tissues and to produce color and fluorescence changes upon crosslinking. We have characterized the effects of genipin concentration and incubation duration on the mechanical and fluorigenic properties of type I collagen gels. Gels were exposed to genipin (0, 1, 5, or 10 mM) for a defined duration (2, 4, 6, or 12 h). Mechanical properties were characterized using parallel plate rheometry, while fluorigenic properties were examined with a spectrofluorimetric plate reader and with a standard, inverted epifluorescent microscope. Additionally, Fourier transform infrared spectroscopy was used to characterize and track the crosslinking reaction in real‐time. Genipin produced significant concentration‐ and incubation‐dependent increases in the storage modulus, loss modulus, and fluorescence intensity. Storage modulus was strongly correlated to fluorescence exponentially. Minimal cytotoxicity was observed for exposure of L929 fibroblasts cultured within collagen gels to 1 mM genipin for 24 h, but significant cell death occurred for 5 and 10 mM genipin. We conclude that genipin can be used to stiffen collagen gels in a relatively short time frame, that low concentrations of genipin can be used to crosslink cell‐populated collagen gels to affect cell behavior that is influenced by the mechanical properties of the tissue scaffold, and that the degree of crosslinking can be reliably assayed optically via simple fluorescence measurements. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Microtopography of titanium suppresses osteoblastic differentiation but enhances chondroblastic differentiation of rat femoral periosteum‐derived cells
Authors: Kubo Katsutoshi , Att Wael , Yamada Masahiro , Ohmi Kuzuhiro , Tsukimura Naoki , Suzuki Takeo , Maeda Hatsuhiko , Ogawa Takahiro
Published: January 2008

Despite the clinical fact that endosseous titanium implants directly contacts periosteum, the behavior and response of the periosteum‐derived cells to surface topography of titanium have rarely been studied. This study examines the effect of titanium surface microtopography on osteoblastic and possibly‐modulated chondroblastic phenotypes of femoral periosteum‐derived cells. Rat femoral periosteum‐derived cells were cultured on either relatively smooth, machined titanium surface or acid‐etched, micro‐roughened titanium surface. The osteoblastic gene expressions, including collagen I, osteopontin and osteocalcin, were downregulated on the acid‐etched surface, compared with the machined surface. Alkaline phosphatase and mineralization activities on the acid‐etched surface were ∼20% of those on the machined surface. Instead, chondroblastic specific genes, including collagen II and IX, and sox 9, were exclusively expressed or highly upregulated on the acid‐etched surface. Alcian blue stain revealed an extensive deposition of glycosaminoglycan on the acid‐etched surface. The cultured matrix on the acid‐etched surface lacked the submicron globular structures that were extensively seen on the machined surface, and contained a remarkably increased percentage of sulfur relative to calcium compared with the culture on the machined surface. These results indicated that titanium microroughness suppresses the osteoblastic phenotype and induces or at least considerably enhances the chondroblastic phenotype of the periosteal cells, suggesting the unique role of titanium surface topography in regulating the periosteal cell differentiation. The suppressive effect of titanium microroughness on the periosteal cells toward the osteoblastic linage was contrasted to the known promotive effect on the bone marrow‐derived osteoblasts. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
The anti‐apoptosis protein, survivin, mediates gastric epithelial cell cytoprotection against ethanol‐induced injury via activation of the p34cdc2 cyclin‐dependent kinase
Authors: Jones Michael K. , Padilla Oscar R. , Webb Nicole A. , Norng Manith
Published: January 2008

The anti‐apoptosis protein, survivin, promotes cell survival and mitosis. Recent studies have demonstrated that survivin is expressed in normal gastric mucosa. Using an in vitro model, we examined whether survivin plays a role in the cytoprotection produced in gastric mucosa by mild irritant ethanol (ETOH) against subsequent exposure to concentrated ETOH. Pre‐treatment of rat gastric epithelial cells with 1% ETOH reduced cell death, in response to subsequent incubation with 5% ETOH, by 94% (P < 0.005). This pre‐treatment also resulted in increased total and phosphorylated survivin protein levels by 180% (P < 0.0001) and 540% (P < 0.0002), respectively, which required the p34cdc2 cell cycle‐dependent kinase. The cytoprotective effect was abrogated upon siRNA knockdown of survivin protein levels. Further, overexpression of exogenous survivin resulted in significant cytoprotection by 62% (P < 0.02) in the absence of any pre‐treatment. We further examined the in vivo relevance of these findings. In fasted rats, administration of 20% ETOH, which we found to be 93% (P < 0.0001) cytoprotective against 50% ETOH challenge, resulted in increased total and phosphorylated survivin protein levels by 234% (P < 0.001) and 214% (P < 0.02), respectively. Administration of 20% ETOH resulted in increased gastric p34cdc2 activity by 146% (P < 0.01). Inhibition of p34cdc2 by the potent inhibitor, roscovitine, abolished the increased survivin levels in response to pre‐administration of 20% ETOH and reduced the cytoprotection against 50% ETOH challenge by 59% (P < 0.01). These results indicate that survivin is a key mediator of cytoprotection against ETOH‐induced gastric injury, acting at the epithelial cell level, by a mechanism that is dependent, in part, on p34cdc2. J. Cell. Physiol. 215: 750–764, 2008. © 2008 Wiley‐Liss, Inc.
Investigating a clonal human periodontal ligament progenitor/stem cell line in vitro and in vivo
Authors: Fujii Shinsuke , Maeda Hidefumi , Wada Naohisa , Tomokiyo Atsushi , Saito Masahiro , Akamine Akifumi
Published: January 2008

The lifespan of the tooth is influenced by the periodontal ligament (PDL), a specialized connective tissue that connects the cementum with the tooth socket bone. Generation of a cell line from PDL progenitor/stem cells would allow development of tissue engineering‐based regenerative PDL therapy. However, little is known about the characteristics of PDL progenitor/stem cells because PDL tissue consists of a heterogeneous cell population and there are no pure PDL cell lines. Recently, we succeeded in immortalizing primary human PDL fibroblasts (HPLFs) by transfecting them with SV40 T‐antigen and hTERT (Cell Tissue Res 2006; 324: 117–125). In this study, we isolated three clonal cell lines from these immortalized cells (lines 1–4, 1–11, and 1–24) that express RUNX‐2, Col I, ALP, OPN, OCN, RANKL, OPG, scleraxis, periostin, Col XII, and α‐SMA mRNA. Immunocytochemical analysis demonstrated that CD146 was expressed in cell lines 1–4 and 1–11 and that STRO‐1 was expressed in lines 1–11 and 1–24. Lines 1–4 and 1–11 differentiated into osteoblastic cells and adipocytes when cultured in lineage‐specific differentiation media. Four weeks after transplanting cell line 1–11 into immunodeficient mice with β‐tricalcium phosphate (β‐TCP), the transplant produced cementum/bone‐like tissues around the β‐TCP. Eight weeks after transplantation, the 1–11 cell transplant formed PDL‐like structures on the surface of the β‐TCP. These data suggest that cell line 1–11 was derived from a progenitor/stem cell present in the PDL and should be very useful for studying the biology and regeneration of human periodontium. J. Cell. Physiol. 215: 743–749, 2008. © 2008 Wiley‐Liss, Inc.
Ets‐1 triggers and orchestrates the malignant phenotype of mammary cancer cells within their matrix environment
Authors: Furlan Alessandro , Vercamer Chantal , Desbiens Xavier , Pourtier Albin
Published: January 2008

Acquisition of invasive characteristics is a hallmark of breast carcinoma progression. During this phenomenon, Ets‐1 transcription factor overexpression is induced and associated with breast cancer invasiveness, and poor prognosis. We hypothesized that Ets‐1 transcription factor could be the orchestrator of a genetic program inducing the expression of genes necessary for cell motility, as postulated by the tumor microenvironment invasion model. We aimed at elucidating the role of Ets‐1 in the molecular control of mammary cancer cell invasion and aggressiveness within their matrix environment. To that purpose, mouse mammary tumor MMT epithelial cells were engineered to stably overexpress Ets‐1, or the dominant negative Ets‐1 DNA Binding domain. The biological function of Ets‐1 was assessed in three‐dimensional extracellular matrix systems recreating a microenvironmental architecture resembling in vivo geometric constraints. Ets‐1 overexpression provided MMT cells with a motile and invasive phenotype, leading to cell scattering, and impairing multicellular organization in matrix‐mimicking gels. We evidenced that Ets‐1 promoted HGF/SF activation, and the expression of its receptor, c‐Met. Ets‐1 also orchestrated switches in integrin expression pattern, towards a pro‐migratory and malignant phenotype. Moreover, Ets‐1 concomitantly triggered matrix metalloproteinases (MMP) expression and activation, thus contributing to cell scattering. Functional relevance of these observations was confirmed with blocking antibodies or MMP inhibitors. Our data highlight a critical role for Ets‐1 in the orchestration of a network of molecular and phenotypic events, converging to enhance malignant features and invasion by mammary cancer cells of their environment. Ets‐1 overexpression hence appears as a probable key step for breast cancer progression. J. Cell. Physiol. 215: 782–793, 2008. © 2008 Wiley‐Liss, Inc.
The x cystine/glutamate antiporter: A potential target for therapy of cancer and other diseases
Authors: Lo Maisie , Wang Yu‐Zhuo , Gout Peter W.
Published: January 2008

The x cystine/glutamate antiporter is a major plasma membrane transporter for the cellular uptake of cystine in exchange for intracellular glutamate. Its main functions in the body are mediation of cellular cystine uptake for synthesis of glutathione essential for cellular protection from oxidative stress and maintenance of a cystine:cysteine redox balance in the extracellular compartment. In the past decade it has become evident that the x transporter plays an important role in various aspects of cancer, including: (i) growth and progression of cancers that have a critical growth requirement for extracellular cystine/cysteine, (ii) glutathione‐based drug resistance, (iii) excitotoxicity due to excessive release of glutamate, and (iv) uptake of herpesvirus 8, a causative agent of Kaposi's sarcoma. The x transporter also plays a role in certain CNS and eye diseases. This review focuses on the expression and function of the x transporter in cells and tissues with particular emphasis on its role in disease pathogenesis. The potential use of x inhibitors (e.g., sulfasalazine) for arresting tumor growth and/or sensitizing cancers is discussed. J. Cell. Physiol. 215: 593–602, 2008. © 2008 Wiley‐Liss, Inc.
On a conjecture about edge irregular total labelings
Authors: Brandt Stephan , Miškuf Jozef , Rautenbach Dieter
Published: January 2008

As our main result, we prove that for every multigraph G = (V, E) which has no loops and is of order n, size m, and maximum degree $\Delta < {{{10}}^{-{{3}}}{{m}}\over \sqrt{{{8}}{{n}}}}$ there is a mapping ${{f}}:{{V}}\cup {{E}}\to \big\{{{1}},{{2}},\ldots,\big\lceil{{{m}}+{{2}}\over {{3}}}\big\rceil\big\}$ such that ${{f}}({{u}})+{{f}}({{uv}})+{{f}}({{v}})\not={{f}}({{u}}')+{{f}}({{u}}'{{v}}')+{{f}}({{v}}')$ for every ${{uv}},{{u}}'{{v}}'\in {{E}}$ with ${{uv}}\not={{u}}'{{v}}'$. Functions with this property were recently introduced and studied by Bača et al. and were called edge irregular total labelings. Our result confirms a recent conjecture of Ivančo and Jendrol′ about such labelings for dense graphs, for graphs where the maximum and minimum degree are not too different in terms of the order, and also for large graphs of bounded maximum degree. © 2008 Wiley Periodicals, Inc. J Graph Theory 57: 333–343, 2008
On conjectures of Frankl and El‐Zahar
Authors: Llano Bernardo , Montellano‐Ballesteros Juan José , Rivera‐Campo Eduardo , Strausz Ricardo
Published: January 2008

An induced subgraph ${\cal S}$ of a graph ${\cal G}$ is called a derived subgraph of ${\cal G}$ if ${\cal S}$ contains no isolated vertices. An edge e of ${\cal S}$ is said to be residual if e occurs in more than half of the derived subgraphs of ${\cal S}$. In this article, we prove that every simple graph with at least one edge contains a non‐residual edge. This was conjectured by El‐Zahar in 1997. © 2008 Wiley Periodicals, Inc. J Graph Theory 57: 344–352, 2008
Turán's theorem and k‐connected graphs
Authors: Bougard Nicolas , Joret Gwenaël
Published: January 2008

The minimum size of a k‐connected graph with given order and stability number is investigated. If no connectivity is required, the answer is given by Turán's Theorem. For connected graphs, the problem has been solved recently independently by Christophe et al., and by Gitler and Valencia. In this article, we give a short proof of their result and determine the extremal graphs. We settle the case of 2‐connected graphs, characterize the corresponding extremal graphs, and also extend a result of Brouwer related to Turán's Theorem. © 2008 Wiley Periodicals, Inc. J Graph Theory 58: 1–13, 2008
Ore‐type degree conditions for a graph to be H‐linked
Authors: Kostochka Alexandr V. , Yu Gexin
Published: January 2008

Given a fixed multigraph H with V(H) = {h1,…, hm}, we say that a graph G is H‐linked if for every choice of m vertices v1, …, vm in G, there exists a subdivision of H in G such that for every i, vi is the branch vertex representing hi. This generalizes the notion of k‐linked graphs (as well as some other notions). For a family ${\cal H}$ of graphs, a graph G is ${\cal H}$‐linked if G is H‐linked for every $H\in {\cal H}$. In this article, we estimate the minimum integer r = r(n, k, d) such that each n‐vertex graph with $\sigma_{2}(G)\ge {r}$ is ${\cal H}$‐linked, where ${\cal H}$ is the family of simple graphs with k edges and minimum degree at least $d \ge 2$. © 2008 Wiley Periodicals, Inc. J Graph Theory 58: 14–26, 2008
Cartilage repair with osteochondral autografts in sheep: Effect of biophysical stimulation with pulsed electromagnetic fields
Authors: Benazzo Franco , Cadossi Matteo , Cavani Francesco , Fini Milena , Giavaresi Gianluca , Setti Stefania , Cadossi Ruggero , Giardino Roberto
Published: January 2008

The effect of pulsed electromagnetic fields (PEMFs) on the integration of osteochondral autografts was evaluated in sheep. After osteochondral grafts were performed, the animals were treated with PEMFs for 6 h/day or sham‐treated. Six animals were sacrificed at 1 month. Fourteen animals were treated for 2 months and sacrificed at 6 months. At 1 month, the osteogenic activity at the transplant–host subchondral bone interface was increased in PEMF‐treated animals compared to controls. Articular cartilage was healthy in controls and stimulated animals. At 6 months, complete resorption was observed in four control grafts only. Cyst‐like resorption areas were more frequent within the graft of sham‐treated animals versus PEMF‐treated. The average volume of the cysts was not significantly different between the two groups; nevertheless, analysis of the variance of the volumes demonstrated a significant difference. The histological score showed no significant differences between controls and stimulated animals, but the percentage of surface covered by fibrous tissue was higher in the control group than in the stimulated one. Interleukin‐1 and tumor necrosis factor‐α concentration in the synovial fluid was significantly lower, and transforming growth factor‐β1 was significantly higher, in PEMF‐treated animals compared to controls. One month after osteochondral graft implantation, we observed larger bone formation in PEMF‐treated grafts which favors early graft stabilization. In the long term, PEMF exposure limited the bone resorption in subchondral bone; furthermore, the cytokine profile in the synovial fluid was indicative of a more favorable articular environment for the graft. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:631–642, 2008
Effect of vertebroplasty filler materials on viability and gene expression of human nucleus pulposus cells
Authors: Lazáry Áron , Speer Gábor , Varga Péter Pál , Balla Bernadett , Bácsi Krisztián , Kósa János P. , Nagy Zsolt , Takács István , Lakatos Péter
Published: January 2008

Consequences of intradiscal cement leakage—often occurring after vertebral cement augmentation for the treatment of vertebral compression fractures—are still unknown. In this study, we have investigated the influences of vertebroplasty filler materials (polymethylmethacrylate‐, calcium phosphate‐ and calcium sulfate‐based bone cement) on isolated nucleus pulposus cells. Cell viability of cultured human nucleus pulposus cells were measured after treatment with vertebroplasty filler materials. Gene expression profile of selected genes was determined with quantitative real‐time PCR. The widely used polymethylmethacrylate and calcium phosphate cement significantly decreased cell number in a dose‐ and time‐dependent manner while calcium sulfate cement affected cell viability less. Expression of genes involved in matrix metabolism of nucleus pulposus—aggrecan, collagens, small proteoglycans—as well as important transcription factors have also significantly changed due to treatment (e.g., 2.5‐fold decrease in aggrecan expression was determined in cultures due to polymethylmethacrylate treatment). Our results suggest that vertebroplasty filler materials—depending on the type of applied material—can accelerate the degeneration of nucleus pulposus cells resulting in a less flexible disc in case of intradiscal cement leakage. This process may increase the risk of a subsequent new vertebral fracture, the main complication of vertebral augmentation. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:601–607, 2008
Regulation of embryonic endochondral ossification by Smurf2
Authors: Wu Qiuqian , Wang Meina , Zuscik Michael J. , Chen Di , O'Keefe Regis J. , Rosier Randy N.
Published: January 2008

Smurf2 is an E3 ubiquitin ligase that targets TGF‐β receptor activated Smad2 and Smad3 for the proteasome in primary articular chondrocytes, thus stimulating their hypertrophic differentiation. Comparatively, how Smurf2 functions in growth plate chondrocytes in a developing long bone is an open question. In this study, we measured the mRNA levels of endogenous Smurf2 and type X collagen in chick growth plate at different embryonic stages to monitor the correlation between the level of Smurf2 expression and chondrocyte maturational stage. We found that high levels of Smurf2 were associated with the differentiative and proliferative stages, while Smurf2 levels were thereafter decreased as the chondrocytes matured toward hypertrophy. In addition, we injected Smurf2‐RCAS into chick wing buds at HH stage 20–23 and examined how the ectopic overexpression of Smurf2 in condensing chondrogenic mesenchyme affects the subsequent process of chondrocyte maturation and ossification during embryonic development. Histological analysis showed that overexpression of Smurf2 in a developing wing bud accelerated chondrocyte maturation and endochondral ossification, which may result from a decrease in TGF‐β signaling in the infected chondrocytes with Smurf2‐RCAS. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:704–712, 2008
One intra‐articular injection of hyaluronan prevents cell death and improves cell metabolism in a model of injured articular cartilage in the rabbit
Authors: Jansen Edwin J.P. , Emans Pieter J. , Douw Conny M. , Guldemond Nick A. , Van Rhijn Lodewijk W. , Bulstra Sjoerd K. , Kuijer Roel
Published: January 2008

The purpose of this study was to determine the effect of one intra‐articular injection of hyaluronan on chondrocyte death and metabolism in injured cartilage. Twenty‐three 6‐month‐old rabbits received partial‐thickness articular cartilage defects created on each medial femoral condyle. In order to examine the effect on articular cartilage surrounding iatrogenic cartilage lesions, which can occur during arthroscopic procedures, Study 1 was performed: in 14 rabbits both knees were immediately rinsed with 0.9% NaCl. Experimental knees were treated with hyaluronan. Six rabbits were sacrificed at 2 days; eight rabbits 3 months postoperatively. Histomorphometric analysis was used for studying cell death in cartilage next to the defect. In order to examine the effect on longer lasting lesions, more reflecting the clinical situation, Study 2 was performed: after 6 months knee joints of nine rabbits were (i) irrigated with 0.9% NaCl, (ii) treated with hyaluronan after irrigation with 0.9% NaCl, or (iii) sham‐treated. After 7 days patellas were used to study the chondrocyte metabolism by measuring the [35S]sulfate incorporation. Study 1: Two days postoperatively, in hyaluronan‐treated cartilage the percentage of dead cells was 6.7%, which was significantly lower compared to 16.2% in saline‐treated cartilage. After 3 months the percentages of dead cells in both groups were statistically similar. Study 2: Hyaluronan treatment resulted in significantly higher [35S]sulfate incorporation compared to knees irrigated with 0.9% NaCl. These results suggest a potential role for hyaluronan in preventing cell death following articular cartilage injury. One injection of hyaluronan improved cartilage metabolism in knees with 6‐month‐old cartilage defects. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:624–630, 2008
Artificial biological ligament: Its making, testing, and experimental study on animals
Authors: Wang Kun , Zhu Lei , Cai Daozhang , Zeng Chun , Lu Huading , Xu Guofeng , Guo Xiaoming , Lin Siming , Cheng Shunqiao
Published: January 2008

By applying a novel biochemical technique using porcine tendon as the raw material with its antigen minimized, we developed an artificial biological ligament (ABL). We examined and tested its structure, mechanical properties, and biocompatibility and explored the feasibility of reconstructing the anterior cruciate ligament (ACL) with ABL. By means of treating porcine tendon with epoxy crosslinking fixation, diversified antigen minimization process, mechanic enhancement modification, and surface activating process, we fabricated the ABL samples. We then analyzed its in vivo and in vitro performances, respectively, with animal (goat) implantation, histological examination, scanning electron microscope, cells culture, and mechanical tests before and after animal implants. The appearance of ABL was similar to that of normal human ligament. Histological examination showed that the ABL was composed of collagen fibers with no cells. Electron microscope examination revealed that the ABL was composed of hair‐appearing and fiber‐like objects running uniformly in a certain direction and closely parallel‐arranged. Three weeks after xenogenic marrow matrix cells were cultured on the surface of the ABL, it was noted that cells adhered and the matrix secreted by the cells precipitated around the cells. There were no cells found inside the ABL. The average diameter of ABL was 5 mm and the mechanical test at a speed of 100 mm/min showed that its average tensile limit was 927.19 N; the tension‐resistant strength was 47.22 N/mm. Those measurements were close to the corresponding parameters of the normal goat ACL. Twelve weeks after ABL replacement of the goat ACL, synovial membrane covering with the ingrowths of small blood vessels was seen on the surface of the implant. Fifty weeks after the replacement, the ABL material was partially replaced by regenerated host ligament‐like tissue. Around the ABL material fibers in the bone tunnel close to the joint surface the direct connection mode, ligament‐fibro cartilage‐calcified cartilage‐bone, was seen. As we used the unique biochemical technique and minimized the xenogenic protein immunogenicity of the porcine tendon, ABL showed acceptable biomechanical properties and superior biocompatibility. As a substitute for ligament in the reconstruction of the ACL, ABL has a promising prospect in clinical applications. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Applications of statistical condition estimation to the solution of linear systems
Authors: Laub A. J. , Xia J.
Published: January 2008

This paper discusses some applications of statistical condition estimation (SCE) to the problem of solving linear systems. Specifically, triangular and bidiagonal matrices are studied in some detail as typical of structured matrices. Such a structure, when properly respected, leads to condition estimates that are much less conservative compared with traditional non‐statistical methods of condition estimation. Some examples of linear systems and Sylvester equations are presented. Vandermonde and Cauchy matrices are also studied as representative of linear systems with large condition numbers that can nonetheless be solved accurately. SCE reflects this. Moreover, SCE when applied to solving very large linear systems by iterative solvers, including conjugate gradient and multigrid methods, performs equally well and various examples are given to illustrate the performance. SCE for solving large linear systems with direct methods, such as methods for semi‐separable structures, are also investigated. In all cases, the advantages of using SCE are manifold: ease of use, efficiency, and reliability. Copyright © 2008 John Wiley & Sons, Ltd.
Gene flow from glyphosate‐resistant crops
Authors: Mallory‐Smith Carol , Zapiola Maria
Published: January 2008

Gene flow from transgenic glyphosate‐resistant crops can result in the adventitious presence of the transgene, which may negatively impact markets. Gene flow can also produce glyphosate‐resistant plants that may interfere with weed management systems. The objective of this article is to review the gene flow literature as it pertains to glyphosate‐resistant crops. Gene flow is a natural phenomenon not unique to transgenic crops and can occur via pollen, seed and, in some cases, vegetative propagules. Gene flow via pollen can occur in all crops, even those that are considered to be self‐pollinated, because all have low levels of outcrossing. Gene flow via seed or vegetative propagules occurs when they are moved naturally or by humans during crop production and commercialization. There are many factors that influence gene flow; therefore, it is difficult to prevent or predict. Gene flow via pollen and seed from glyphosate‐resistant canola and creeping bentgrass fields has been documented. The adventitious presence of the transgene responsible for glyphosate resistance has been found in commercial seed lots of canola, corn and soybeans. In general, the glyphosate‐resistant trait is not considered to provide an ecological advantage. However, regulators should consider the examples of gene flow from glyphosate‐resistant crops when formulating rules for the release of crops with traits that could negatively impact the environment or human health. Copyright © 2008 Society of Chemical Industry
Cleaning of albumin‐contaminated Ti and Cr surfaces: an XPS and QCM study
Authors: Payet Vincent , Brunner Susanne , Galtayries Anouk , Frateur Isabelle , Marcus Philippe
Published: January 2008

The cleaning of protein‐contaminated metallic surfaces is a major challenge for non‐disposable devices used for biomedical applications and in the food industry. The objective of this work is to estimate the cleaning efficiency of sodium dodecyl sulfate (SDS) buffered at pH 7.4, as a function of temperature, for an immersion time of 15 h. Bovine serum albumin (BSA) is pre‐adsorbed on pure Ti‐ and Cr‐deposited quartz crystals. BSA adsorption and removal were investigated by X‐ray photoelectron spectroscopy (XPS) and quartz crystal microbalance (QCM). Before cleaning, the amount of adsorbed BSA corresponds to one monolayer, and the oxide thickness is about 5 nm for the Cr quartz (Cr3+ in oxide and hydroxide). For Ti quartz, the metal is not detected (10 nm or more of Ti4+ in TiO2). The C 1s and N 1s peaks indicate that the cleaning with SDS is achieved at 37 °C for Ti. For Cr, there are no significant changes from 37 to 60 °C. At 80 °C, the surface is partially cleaned (70% efficiency); at 90 °C, the surface cleaning with SDS is achieved (90% efficiency). The oxide layer of the chromium sample has not changed in composition and thickness.

QCM measurements were performed at 37 °C. Switches between BSA and SDS solutions indicate that for Ti, SDS induces partial BSA removal (40% efficiency) after ∼20 min, while for Cr it seems that SDS adsorbs reversibly on the BSA layer, without any cleaning effect. Thus, QCM results are in agreement with XPS data obtained at the same temperature. Copyright © 2008 John Wiley & Sons, Ltd.
The volume‐sensitive chloride channel inhibitors prevent both contractile dysfunction and apoptosis induced by doxorubicin through PI3kinase, Akt and Erk 1/2
Authors: de Tassigny Alexandra d'Anglemont , Berdeaux Alain , Souktani Rachid , Henry Patrick , Ghaleh Bijan
Published: January 2008

Contractile dysfunction and cardiomyopathies secondary to apoptotic cell death are limiting factors for treating cancer with doxorubicin. Inhibition of volume‐sensitive chloride currents (ICl,vol) has been reported to blunt doxorubicin‐induced apoptosis in cardiomyocytes. To investigate cellular contractility during acute induction of apoptosis by doxorubicin and to determine whether ICl,vol inhibitors are able to prevent the subsequent contractile dysfunction, electrically paced ventricular myocytes freshly isolated from adult rabbits were acutely exposed to doxorubicin in the presence and absence of ICl,vol inhibitors IAA‐94 or DIDS. Doxorubicin induced increases in both annexin V labelling and caspase‐3 activity and decreases in cell volume. Alteration in cardiac contractility was observed after doxorubicin exposure. Both IAA‐94 and DIDS abolished the doxorubicin‐induced decreases in peak shortening and cell volume as well as the increases in caspase‐3 activity and annexin V labelling. These protective effects of ICl,vol inhibitors were abolished by previous inhibition of PI3kinase, Akt and Erk 1/2. Thus, ICl,vol inhibitors prevent doxorubicin‐induced apoptosis and subsequent contractile dysfunction through PI3kinase/Akt and Erk 1/2. Inhibition of ICl,vol may represent a new pharmacological strategy for developing cytoprotective drugs against apoptotic cell death and contractile dysfunction.
Strategies to Maintain Sample Integrity Using a Liquid-Filled Automated Liquid-Handling System with Fixed Pipetting Tips
Authors: Ouyang Zheng , Federer Susi , Porter Gregory , Kaufmann Christoph , Jemal Mohammed
Published: January 2008

There are several advantages to using liquid-filled automated liquid-handling systems equipped with reusable fixed tips for sample handling of bioanalytical assays. However, liquid-handling parameters that have not been optimized can lead to sample dilution by the system liquid of the automated liquid handler causing possible inaccuracy of sample delivery. In this investigation, liquid-handling parameters involving sample delivery, such as aspiration speed, dispense speed, partition volume, excess volume, and air gaps, were closely examined to understand their roles in the accurate delivery of the sample. Consequently, two strategies for optimization of the parameters are presented that achieve accurate sample delivery while maintaining sample integrity.
‘Gentlemen, the Cheese Is All Gone!’ British POWs, the ‘Great Escape’ and the Anglo-German Agreement for Compensation to Victims of Nazism
Authors: SCHRAFSTETTER SUSANNA
Published: January 2008

In 1964 the West German government agreed to provide £1 million in financial compensation to British victims of National Socialism. The distribution of the money, organised by the British foreign office, turned into a major public scandal, as a number of British POWs, among them survivors of the ‘great escape’, had their claims rejected. By examining the refusal of several British POWs to accept their exclusion from the scheme, the article addresses the interplay of political pressure and public opinion that led to a parliamentary inquiry into what became known as ‘the Sachsenhausen affair’ in 1967. Given that provisions of the agreement with West Germany had precluded indemnification to mistreated POWs, the distribution of the money almost inevitably led to bitterness and discontent. From this perspective, the article explores the impact of the Great Escape on British memory of the war, the public reception of the film The Great Escape (1963), and the way in which public memory influenced the debate on compensation.
The Global Development Race and the Samaritan's Dilemma: Development Aid Discourse in Danish Agriculture, 1960–1970
Authors: SVENDSEN GUNNAR LIND HAASE , SVENDSEN GERT TINGGAARD
Published: January 2008

Why has ‘development aid’ been donated by so-called developed to under-developed populations since the Second World War? Using discourse analysis, this article provides partial answers to this riddle. First, we suggest that donor motives may be rooted in an ideology of ‘being good’, which, paradoxically, motivates recipients to be helpless – that is, a Samaritan's dilemma. Second, drawing on journal articles published in 1960–70, we test this theory by tracing a global development discourse and ‘goodness ideology’ in a Western country such as Denmark – a process that was strongly influenced by the agricultural co-operative movement, which sought to export the ‘Danish co-operative model’.
Umstellen von Spitälern auf außerordentliche Lagen
Authors: Leutenegger Adrian
Published: January 2008

Eine außerordentliche Patientenbelastung erfordert außerordentliche spitalinterne Maßnahmen zur Leistungssteigerung. Eine vorbereitete Alarmorganisation, einfache Führungsstrukturen mit klarer Kompetenzregelung, betriebsorganisatorische Maßnahmen zur Patientenaufnahme, Triage und Behandlung sowie Kommunikationsmittel zur Information und Führung nach innen und nach außen sind die wesentlichen Punkte, die in einem Katastrophendispositiv vorbereitet sein müssen. Ein solches, den realistischen Möglichkeiten des betreffenden Spitals und der Bedrohungslage angepasstes Dispositiv muss regelmäßig überprüft werden und alle Mitarbeiter sind ebenso regelmäßig zu schulen. Dieser Beitrag gibt Richtlinien und Hinweise zur Planung eines solchen Katastrophendispositivs.
Making Choices: The Development of an Assessment Procedure
Authors: Oppenheimer Louis , John-Roberts Eveline , Taal Margot
Published: January 2008

1 The present manuscript is based on the MA thesis of the second author. We would like to express our gratitude to two anonymous reviewers for the comments on an earlier draft of this paper. The purpose of this study was to develop an instrument for the assessment of children's understanding of processes involved in the formulation of goals, making choices, and the role of own responsibility in making choices (i. e., planning components). In the first study, a list of concepts consisting of 54 items was presented to 83 children (mean ages 10.9 and 13.9 years). Principal component analyses resulted in a list - called “Cost and Profit Concepts List” - consisting of 22 items with a three-factor structure. The factors referred to children's understanding of processes involved in making choices between goals and alternative strategies to attaining goals and their own responsibility in making choices. In the second study, the instrument was presented to 174 children divided into three age groups (mean ages 8.7, 10.8, and 13.7 years). An identical factor structure for the 22 items was found. Internal consistency reached .68. Significant age differences were present for each factorial dimension. Girls evidenced an earlier understanding than boys of the role of their own responsibility in making choices. These findings indicate that the “Cost and Profit Concepts List” is an adequate assessment instrument for children's understanding of components of planning and discriminates sufficiently between age groups.
Selection principle for various modes of spatially nonuniform electrochemical oscillations
Authors: Fukushima Satoshi , Nakanishi Shuji , Nakato Yoshihiro , Ogawa Toshiyuki
Published: January 2008

The pattern selection principle for various modes of spatially nonuniform oscillation was investigated by taking a current oscillation of negative differential resistance type, appearing in H2O2 reduction on platinum (Pt) ring electrodes, as a model system. In experiments, various modes of spatiotemporal oscillation, such as a spatially uniform oscillation, standing wave oscillation, and rotating wave oscillation, appeared depending on the applied potential and the distance between the Pt-ring electrode and the reference electrode. A simple mathematical model for the spatiotemporal patterns at the electrode surface was proposed. Numerical calculations and nonlinear bifurcation analysis based on the proposed model reproduced all the essential features of the experimental results and clarified the pattern selection principle.
Low-Energy Lone Electron Exhibits Relativistic Hysteresis
Authors: Schwarzschild Bertram
Published: January 2008

There was to have been a birthday party last September in Gerald Gabrielse's lab at the University of Washington. But, sadly, the young honoree met an untimely end just two months shy of its first birthday. Having inadvertently been allowed a bit too much axial excitation, it collided with the cap electrode of the Penning trap that had been its home for more than ten months, and vanished.
Grenoble, It Seems, Will Get European Synchrotron Facility
Authors: Schwarzschild Bertram
Published: January 2008

The storm of controversy surrounding the site selection for the European Synchrotron Radiation Facility has tended to obscure the prodigious scientific and technological import of this proposed new x-ray source. The ESRF, a 776-meter-circumference storage ring for 5- or 6-GeV electrons, would be the first synchrotron radiation ring designed explicitly for undulator and wiggler sources of hard-x-ray beams. Most high-energy synchrotron light sources, having begun life as electronpositron storage rings for high-energy physics, are not optimized for synchrotron radiation, and they have little room for inserting undulators and wigglers.