bluuebunny/crossref_metadata_2025_split huggingface dataset:
On generalized Helmholtz type equations in concentric annular domains in ℝ3
Authors: Constales Denis , Grob Dennis , Kraußhar Rolf Sören 
Published: August 2009

AbstractIn this paper we consider inhomogeneous generalized Helmholtz type equations (Δ+λ2)u=f in the annulus of an arbitrary ball in ℝ3 with given boundary conditions, where we assume that λ is an arbitrary complex number. Applying the hypercomplex operator calculus, one can express the solutions in terms of quaternionic integral operators. The quantitative entities to be determined in order to calculate these integral operators in practice are the Cauchy kernel and the Bergman kernel for eigensolutions to the Dirac operator in ℝ3. In contrast to the Cauchy kernel, which is universal for all domains in ℝ3, the Bergman kernel depends on the domain. In this paper, we give an explicit formula for the Bergman kernel of the annulus of a ball in ℝ3 with arbitrary radii 0<R1<R2<+∞ in terms of explicit special functions. With the knowledge of the Bergman kernel, the appearing integral operators can be evaluated fully analytically and thus provide us with explicit formulas for the solutions. Copyright © 2009 John Wiley & Sons, Ltd.
Linearization of the Riemann problem for a triangular system of conservation laws and delta shock wave formation process
Authors: Mitrovic D. , Bojkovic V. , Danilov V. G. 
Published: August 2009

AbstractUsing the weak asymptotic method, we approximate a triangular system of conservation laws arising from the so‐called generalized pressureless gas dynamics by a diagonal linear system. Then, we apply the usual method of characteristics to find approximate solution to the original system. As a consequence, we shall see how the delta shock wave naturally arises along the characteristics.Also, we propose a procedure that could be applied to more general systems of conservation laws. Copyright © 2009 John Wiley & Sons, Ltd.
Stationary solutions to the Falk system on shape memory alloys
Authors: Suzuki Takashi , Tasaki Souhei 
Published: August 2009

AbstractWe study the Falk model system describing martensitic phase transitions in shape memory alloys. Its physically closed stationary state is formulated as a nonlinear eigenvalue problem with a non‐local term. Then, some results on existence, stability, and bifurcation of the solution are proven. In particular, we prove the existence of dynamically stable nontrivial stationary solutions. Copyright © 2009 John Wiley & Sons, Ltd.
Robust structural damage identification based on multi‐objective optimization
Authors: Jung Sungmoon , Ok Seung‐Yong , Song Junho 
Published: August 2009

AbstractInverse analysis for structural damage identification often involves an optimization process that minimizes the discrepancies between the computed responses and the measured responses. Conventional single‐objective optimization approach defines the objective function by combining multiple error terms into a single one, which leads to a weaker constraint in solving the identification problem. A multi‐objective approach is proposed, which minimizes multiple error terms simultaneously. Its non‐domination‐based convergence provides a stronger constraint that enables robust identification of damages with lower false‐negative detection rate. Another merit of the proposed approach is quantified confidence in damage detection through processing Pareto‐optimal solutions. Numerical examples that simulate static testing are provided to compare the proposed approach with conventional formulation based on single‐objective optimization. Copyright © 2009 John Wiley & Sons, Ltd.
Applicability of electrical resistivity tomography monitoring to coarse blocky and ice‐rich permafrost landforms
Authors: Hilbich C. , Marescot L. , Hauck C. , Loke M. H. , Mäusbacher R. 
Published: August 2009

AbstractThe inversion and interpretation of electrical resistivity tomography (ERT) data from coarse blocky and ice‐rich permafrost sites are challenging due to strong resistivity contrasts and high contact resistances. To assess temporal changes during ERT monitoring (ERTM), corresponding inversion artefacts have to be separated from true subsurface changes. Appraisal techniques serve to analyse an ERTM data set from a rockglacier, including synthetic modelling, the depth of investigation index technique and the so‐called resolution matrix approach. The application of these methods led step by step to the identification of unreliable model regions and thus to the improvement in interpretation of temporal resistivity changes. An important result is that resistivity values of model regions with strong resistivity contrasts and highly resistive features are generally of critical reliability, and resistivity changes within or below the ice core of a rockglacier should therefore not be interpreted as a permafrost signal. Conversely, long‐term degradation phenomena in terms of warming of massive ground ice at the permafrost table are detectable by ERTM. Copyright © 2009 John Wiley & Sons, Ltd.
Past permafrost on the Mid‐Atlantic Coastal Plain, eastern United States
Authors: French Hugh , Demitroff Mark , Newell Wayne L. 
Published: August 2009

AbstractSand‐wedge casts, soil wedges and other non‐diastrophic, post‐depositional sedimentary structures suggest that Late‐Pleistocene permafrost and deep seasonal frost on the Mid‐Atlantic Coastal Plain extended at least as far south as southern Delaware, the Eastern Shore and southern Maryland. Heterogeneous cold‐climate slope deposits mantle lower valley‐side slopes in central Maryland. A widespread pre‐existing fragipan is congruent with the inferred palaeo‐permafrost table. The high bulk density of the fragipan was probably enhanced by either thaw consolidation when icy permafrost degraded at the active layer‐permafrost interface or by liquefaction and compaction when deep seasonal frost thawed. Copyright © 2009 John Wiley & Sons, Ltd.
Genesis of active sand‐filled polygons in lower and central Beacon Valley, Antarctica
Authors: Bockheim James G. , Kurz Mark D. , Soule S. Adam , Burke Andrea 
Published: August 2009

AbstractNonsorted polygons with sand‐filled wedges were investigated in Beacon Valley, Antarctica (77.82°S, 160.67°E) using field observations coupled with 2‐m resolution aerial photography. A gasoline‐powered concrete breaker was employed to expose the sediments of four polygon centres and six wedges from geomorphic surfaces containing tills of two different ages. The excavated polygons ranged from 9 to 16 m in diameter; the sand‐filled wedges ranged from 0.2 to 2.5 m in width. The top of ice‐bonded permafrost ranged from 12 to 62 cm in depth in the polygon centres and from 64 to >90 cm in wedges. One active thermal‐contraction fissure generally was apparent at the surface, but excavations revealed numerous inactive fissures. The wedges contain sand laminations averaging 3 mm in width when viewed in cross‐section. Although most of the polygons were of the sand‐wedge type, some contained ice veins up to 1 cm in width and could be classed as composite wedges. Three stages of polygon development were observed, including well‐developed polygons on Taylor II surfaces (ca. 117 ka), moderately developed polygons on Taylor III surfaces (ca. 200 ka) and poorly expressed polygons on Taylor IVa and older (ca. >1.1 Ma) surfaces. This retrogressive development may be due to sublimation of ice‐bonded permafrost following thermal cracking. With the drop in ice content, the thermal coefficient of expansion of the permafrost may be lowered, which would result in a reduction in tensile stresses. Copyright © 2009 John Wiley & Sons, Ltd.
Tissue is alive: New technologies are needed to address the problems of protein biomarker pre‐analytical variability
Authors: Espina Virginia , Mueller Claudius , Edmiston Kirsten , Sciro Manuela , Petricoin Emanuel F. , Liotta Lance A. 
Published: August 2009

AbstractInstability of tissue protein biomarkers is a critical issue for molecular profiling. Pre‐analytical variables during tissue procurement, such as time delays during which the tissue remains stored at room temperature, can cause significant variability and bias in downstream molecular analysis. Living tissue, ex vivo, goes through a defined stage of reactive changes that begin with oxidative, hypoxic and metabolic stress, and culminate in apoptosis. Depending on the delay time ex vivo, and reactive stage, protein biomarkers, such as signal pathway phosphoproteins will be elevated or suppressed in a manner which does not represent the biomarker levels at the time of excision. Proteomic data documenting reactive tissue protein changes post collection indicate the need to recognize and address tissue stability, preservation of post‐translational modifications, and preservation of morphologic features for molecular analysis. Based on the analysis of phosphoproteins, one of the most labile tissue protein biomarkers, we set forth tissue procurement guidelines for clinical research. We propose technical solutions for (i) assessing the state of protein analyte preservation and specimen quality via identification of a panel of natural proteins (surrogate stability markers), and (ii) using multi‐purpose fixative solution designed to stabilize, preserve and maintain proteins, nucleic acids, and tissue architecture.
Proteomic approaches for investigation of therapy resistance in cancer
Authors: Lage Hermann 
Published: August 2009

AbstractResistance to anticancer therapy is a major obstacle for successful management of patients in oncology. Although in the past, various biological mechanisms involved in therapy resistance, in particular multidrug resistance, have been identified, cancer patients did not really benefit. The mechanisms include the enhanced activity of drug extrusion pumps, modulation of cellular death pathways, alteration and repair of target molecules and various other mechanisms. Together they build a complex network mediating an individual therapy‐resistant phenotype. The improved description of this multifactorial network should be useful for prediction of treatment response and would allow to design an individual‐tailored therapy regiment. Proteome analyzing technologies appear as powerful tools for identifying new factors and protein expression profiles associated with anticancer therapy resistance. In the last years, the application of proteomic techniques identified multiple new factors or protein expression signatures in drug‐resistant cell models and cancerous tissues. However, the functional role and the clinical impact of these findings are not yet clarified. So far, none of the proteomic data were useful for the development of improved diagnostic tests, for prediction of individual therapy response or for development of updated chemosensitizers. Here, the previous therapy resistance‐related proteome data and future perspectives will be discussed.
Proteomics reveals acute pro‐inflammatory and protective responses in rat Kupffer cells and hepatocytes after chemical initiation of liver cancer and after LPS and IL‐6
Authors: Lorenz Olga , Parzefall Wolfram , Kainzbauer Eveline , Wimmer Helge , Grasl‐Kraupp Bettina , Gerner Christopher , Schulte‐Hermann Rolf 
Published: August 2009

AbstractInflammation is a key event in the development of liver cancer. We studied early inflammatory responses of Kupffer cells (KCs) and hepatocyte (HC) after cancer initiation. The chemical carcinogen N‐nitrosomorpholine (NNM) was used in a rat model. We applied a comprehensive analytical strategy including metabolic labeling, 2‐D PAGE, LC‐MS/MS‐based spot identification and shotgun proteomics and thus determined the rates of synthesis of individual proteins, compared whole tissue with isolated constituent cells and performed in vivo to in vitro comparisons of NNM effects. NNM increased synthesis of overall and 138 individual proteins identified in HC and/or KC, indicating reprogramming of metabolism favoring protection, repair and replacement of cell constituents in HC and KC. Secretome analysis by 2‐D PAGE and shotgun proteomics of HC revealed the induction of acute phase proteins, in case of KC of proteases, cytokines and chemokines, indicating inflammatory effects. All responses were induced rapidly, independently of signals from other cells, and closely mimicked the pro‐inflammatory and protective effects of inflammation modulators LPS in KC and IL‐6 in HC. In conclusion, the carcinogen NNM exerts pro‐inflammatory effects in the liver, partially by direct activation of KC. The acute inflammation and its protective component will enhance formation, survival and proliferation of initiated cells and may therefore act synergistically with the genotoxic action of the carcinogen.
PTPIP51 mRNA and protein expression in tissue microarrays and promoter methylation of benign prostate hyperplasia and prostate carcinoma
Authors: Koch Philipp , Petri Meike , Paradowska Agnieszka , Stenzinger Albrecht , Sturm Klaus , Steger Klaus , Wimmer Monika 
Published: August 2009

AbstractBACKGROUNDProtein tyrosine phosphatase interacting protein 51 (PTPIP51) shows a tissue‐specific expression pattern and is associated with cellular differentiation and apoptosis in several mammalian tissues. Overexpression of the full‐length protein enhances apoptosis. It is also expressed in various carcinomas. In this study the expression of PTPIP51 and its in vitro interaction partners was investigated in human benign prostate hyperplasia (BPH) and in prostate carcinoma (PCa).METHODSTissue microarrays of human BPH and PCa were analyzed by immunohistochemistry. For polymerase chain reaction (PCR), cryo samples of BPH and PCa were used. Bisulfite DNA treatment, followed by sequencing of PCR products was performed in order to analyze CpGs methylation within the promoter region of the PTPIP51 gene.RESULTSPTPIP51 mRNA and protein expression was detected in prostatic epithelia of BPH and in tumor cells of PCa, respectively, and within smooth muscle cells of the stromal compartment. A stronger expression was present in nerve fibers, particularly in PCa, in immune cells and in smooth muscle and endothelial cells of vessels of BPH and PCa. On mRNA levels, a slightly elevated expression of PTPIP51 was observed in the PCa group as tested by real‐time quantitative PCR analyses. Methylation experiments revealed that at least 70% of methylated CpGs in the CpG island of the PTPIP51 gene promoter region were identified in BPH samples. In contrast, a loss of methylation has been found in the PCa group.CONCLUSIONThe promoter methylation status of PTPIP51 seems to influence the expression of PTPIP51, which was seen as elevated in the PCa. Prostate 69: 1751–1762, 2009. © 2009 Wiley‐Liss, Inc.
The relationship of neuroendocrine carcinomas to anti‐tumor therapies in TRAMP mice
Authors: Tang Yao , Wang Linbo , Goloubeva Olga , Khan Mohammad Afnan , Lee DongIk , Hussain Arif 
Published: August 2009

AbstractBACKGROUNDNeuroendocrine differentiation and neuroendocrine carcinoma (NEC) have been linked to androgen deprivation in prostate cancers. No previous study has directly connected neuroendocrine phenotypes to chemotherapy. The pathogenesis of prostatic NEC has not yet been determined.METHODSUsing the transgenic adenocarcinoma of mouse prostate (TRAMP) model, we studied tumor progression after hormone ablation (castration) and/or chemotherapy (docetaxel), and analyzed the incidence of NEC as a function of the anti‐tumor therapies. Non‐treated mice were used as controls. Protein expressions in tumor tissues were analyzed by Western blots and immunohistochemistry.RESULTSAlthough all animals developed prostate cancer, no NEC was found in control mice. However, over 30% of the mice that received an anti‐tumor therapy developed NEC. A similar incidence of NEC was found in the castration‐only and docetaxel‐only treatment groups, while a higher incidence was observed in the combined treatment (castration and docetaxel) group. The NEC‐bearing mice had smaller tumors in their prostates and lived longer than mice with adenocarcinoma (ADC‐only). However, NEC tumors had a higher proliferative index and greater potential for metastasis and drug‐resistance, as evidenced by significantly higher expression levels of PCNA, S100A4, and Pgp, but lower levels of E‐cadherin. SV40 T‐antigen was highly expressed in both NEC and ADC tumors.CONCLUSIONSStress induced by anti‐cancer treatments may play a role in NEC development. Although NEC and ADC differ in their expressions of many proteins, a high level of SV40 T‐antigen in both tumor types suggest a common progenitor. Prostate 69: 1763–1773, 2009. © 2009 Wiley‐Liss, Inc.
Preliminary studies on noncovalent hyperbranched polymers based on PNA and DNA building blocks
Authors: Moccia Maria , Musumeci Domenica , Roviello Giovanni N. , Fusco Sabato , Valente Margherita , Bucci Enrico M. , Sapio Roberto , Pedone Carlo , Netti Paolo A. 
Published: August 2009

AbstractIn this work, we report thermodynamic, kinetic, and microrheological studies relative to the formation of PNA‐ and PNA/DNA‐based noncovalent polymeric systems, useful tools for biotechnological and bioengineering applications. We realized two kinds of systems: a PNA‐based system formed by a self‐assembling PNA tridendron, and a PNA/DNA hybrid system formed by a PNA tridendron and a DNA linker. The formation of a three‐dimensional polymeric network, by means of specific Watson–Crick base pairing, was investigated by a detailed UV and CD spectroscopic study. Preliminary microrheology experiments were performed on both systems to evaluate their viscoelastic properties which resulted in agreement with the formation of soluble hyperbranched polymers that could be useful for drug/gene delivery, as well as for encapsulating organic pollutants of different shapes and sizes in environmental applications. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Membrane association and selectivity of the antimicrobial peptide NK‐2: a molecular dynamics simulation study
Authors: Pimthon Jutarat , Willumeit Regine , Lendlein Andreas , Hofmann Dieter 
Published: August 2009

AbstractIn an effort to better understand the initial mechanism of selectivity and membrane association of the synthetic antimicrobial peptide NK‐2, we have applied molecular dynamics simulation techniques to elucidate the interaction of the peptide with the membrane interfaces. A homogeneous dipalmitoylphosphatidylglycerol (DPPG) and a homogeneous dipalmitoylphosphatidylethanolamine (DPPE) bilayers were taken as model systems for the cytoplasmic bacterial and human erythrocyte membranes, respectively. The results of our simulations on DPPG and DPPE model membranes in the gel phase show that the binding of the peptide, which is considerably stronger for the negatively charged DPPG lipid bilayer than for the zwitterionic DPPE, is mostly governed by electrostatic interactions between negatively charged residues in the membrane and positively charged residues in the peptide. In addition, a characteristic distribution of positively charged residues along the helix facilitates a peptide orientation parallel to the membrane interface. Once the peptides reside close to the membrane surface of DPPG with the more hydrophobic side chains embedded into the membrane interface, the peptide initially disturbs the respective bilayer integrity by a decrease of the order parameter of lipid acyl chain close to the head group region, and by a slightly decrease in bilayer thickness. We found that the peptide retains a high content of helical structure on the zwitterionic membrane‐water interface, while the loss of α‐helicity is observed within a peptide adsorbed onto negatively charged lipid membranes. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Design of a bioactive cell‐penetrating peptide: when a transduction domain does more than transduce
Authors: Ward Brian , Seal Brandon L. , Brophy Colleen M. , Panitch Alyssa 
Published: August 2009

AbstractThe discovery of cell‐penetrating peptides (CPPs) has facilitated delivery of peptides into cells to affect cellular behavior. Previously, we were successful at developing a phosphopeptide mimetic of the small heat shock‐like protein HSP20 . Building on this success we developed a cell‐permeant peptide inhibitor of mitogen‐activated protein kinase‐activated protein kinase 2 (MK2). It is well documented that inhibition of MK2 may be beneficial for a myriad of human diseases including those involving inflammation and fibrosis. During the optimization of the activity and specificity of the MK2 inhibitor (MK2i) we closely examined the effect of cell‐penetrating peptide identity. Surprisingly, the identity of the CPP dictated kinase specificity and functional activity to an extent that rivaled that of the therapeutic peptide. The results reported herein have wide implications for delivering therapeutics with CPPs and indicate that judicious choice of CPP is crucial to the ultimate therapeutic success. Published in 2009 by John Wiley & Sons, Ltd.
Highly textured zinc oxide films by room temperature ion beam assisted deposition
Authors: Köhl D. , Luysberg M. , Wuttig M. 
Published: August 2009

AbstractA new ion beam assisted sputter deposition technique has been developed which facilitates room temperature fabrication of thin ZnO films with exceptional structural order. The well‐defined texture of these films is comparable to films deposited at elevated temperatures of typically 200–300 °C in standard sputter processes. Structural investigations reveal that the applied Xe+ ion bombardment mainly affects the nucleation of ZnO crystallites. The high structural order of the nucleation layer is maintained in subsequent stages of film growth. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact of soil moisture on the development of a Sahelian mesoscale convective system: a case‐study from the AMMA Special Observing Period
Authors: Taylor Christopher M. , Harris Phil P. , Parker Douglas J. 
Published: August 2009

AbstractInteractions between the land and atmosphere play an important role in the precipitation of the Sahel. The African Monsoon Multidisciplinary Analysis Special Observing Period provided observations with which to illuminate potential feedback mechanisms. This case‐study highlights a major storm which developed over northern Mali in an area where a research aircraft was surveying the atmospheric response to soil moisture features. Soil moisture variability is characterized using satellite land‐surface temperature data whilst cloud images illustrate the evolution of the storm and its relationship to the surface.Measurements in the planetary boundary layer (PBL) indicate mesoscale variations in pre‐storm humidity and temperature consistent with high evaporation from wet soils. The storm developed above a dry surface within a wetter region with cells first appearing along a wet–dry soil boundary. This suggests that the storm was triggered in association with low‐level convergence driven by the soil moisture pattern. A gravity wave propagating away from a remote mature storm also appears to have played an important role in the initiation, though only in the region of the soil moisture contrast did deep convection become established. Once organised into a Mesoscale Convective System, convection developed over wet areas as well as dry, and indeed at this stage, convection became more intense over wetter soils. This behaviour is consistent with the large gradients in PBL humidity. The study illustrates the complexity of soil moisture–convection feedback loops and highlights the mechanisms which may operate at different stages of a storm's life cycle. Copyright © 2009 Royal Meteorological Society