bluuebunny/crossref_metadata_2025 huggingface dataset:
Equi‐replicated balanced block designs generated by a balanced matrix
Authors: Brzeskwiniewicz H.
Published: May 2007

In this paper it is shown that if N= \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop \sum \limits_{i = 1}^{S_h} $\end{document} cihNih, where cih are some non‐negative integer numbers and Nih are such incidence matrices that Ah = \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop \sum \limits_{i = 1}^{S_h} $\end{document} i Nih is a balanced matrix defined by SHAH (1959), for h = 1, 2,…, p, then a block design with an incidence matrix Ñ = [N, N,…,N] is an equi‐replicated balanced block design. Here the balance of a block design is defined in terms of the matrix M0 introduced by CALIŃSKI (1971).
Measurement of the Relation of Two Characteristics
Authors: Hellmich K.
Published: May 2007

The four‐field table measure K (appearing as K1, K2), which is only a coefficient‐measure, can, by means of a useful transformation, be transformed into a real measure k by means of a graduated scale. The measure k can be compared with other k‐values and, futhermore, reveals directly, by how many per cent the one characteristic can be looked upon as being determined by the other characteristic of the two characteristics under review.
Fluctuations in the Size of Isolated Single‐Species Populations and Natural Selection
Authors: Frisman E. Ya. , Shapiro A. P.
Published: May 2007

This paper discusses the basic types of dynamical behavior of populations obtained in discrete models, such as monotonous dynamics, stable limited cycles, and chaotic variations. All these modes are shown to have possibly arisen in the evolution of limited populations under the effect of density‐independent selection. This effect together with that of density‐dependent non‐selective factors has been termed F‐selection, which is characterized by independence of relative fitnesses from population density, whereas populations may be ecologically limited; in other words, absolute fitnesses prove to be a function of population size. The characteristic of F‐selection is to be not sensitive to changes in population size but to lead to fluctuations, that create conditions for achieving density‐dependent selection.
Lecture‐free biochemistry
Authors: Minderhout Vicky , Loertscher Jennifer
Published: May 2007

Biochemistry courses at Seattle University have been taught exclusively using process oriented guided inquiry learning (POGIL) without any traditional lecture component since 1997. In these courses, students participate in a structured learning environment, which includes a preparatory assignment, an in‐class activity, and a follow‐up skill exercise. Instructor‐designed learning activities provide the content of the course while the cooperative learning structure provides the content‐free procedures that promote development of critical process skills needed for learning. This format enables students to initially explore a topic independently, work together in groups to construct and refine knowledge, and eventually develop deep understanding of the essential concepts. These stages of exploration and concept development form the foundation for application to high level biochemical problems. At the end of this course, most students report feeling confident in their knowledge of biochemistry and report substantial gains in independence, critical thinking, and respect for others.
A case‐based approach increases student learning outcomes and comprehension of cellular respiration concepts
Authors: Rybarczyk Brian J. , Baines Antonio T. , McVey Mitch , Thompson Joseph T. , Wilkins Heather
Published: May 2007

This study investigated student learning outcomes using a case‐based approach focused on cellular respiration. Students who used the case study, relative to students who did not use the case study, exhibited a significantly greater learning gain, and demonstrated use of higher‐order thinking skills. Preliminary data indicate that after engaging with the case study, students were more likely to answer a question addressing misconceptions about cellular respiration correctly when compared with students who did not use the case study. More rigorous testing is needed to fully elucidate whether case‐based learning can effectively clarify student misconceptions related to biological processes.
The eyes have it
Authors: White Harold B.
Published: May 2007

Molecular evolution provides an interesting context in which to use problem‐based learning because it integrates a variety of topics in biology, biochemistry, and molecular biology. This three‐stage problem for advanced students deals with the structure, multiple functions, and properties of lactate dehydrogenase isozymes, and the related evolutionary trade offs of gene sharing versus gene duplication among their corresponding genes. It has directive elements that require students to find and read classic articles, review thermodynamic principles, and apply their understanding to a mythical world wherein dinosaurs continued to evolve. The science fiction writing assignment that brings closure to the problem transformed the problem with respect to student interest and engagement.
Using restriction mapping to teach basic skills in the molecular biology lab
Authors: Walsh Lauren , Shaker Elizabeth , De Stasio Elizabeth A.
Published: May 2007

Digestion of DNA with restriction enzymes, calculation of volumes and concentrations of reagents for reactions, and the separation of DNA fragments by agarose gel electrophoresis are common molecular biology techniques that are best taught through repetition. The following open‐ended, investigative laboratory exercise in plasmid restriction mapping allows students to gain technical expertise while simultaneously exploring the utility of gel electrophoresis and restriction mapping. Because of its interpretive nature, this project also provides data suitable for a written report, and can thus be used to reinforce lessons on figure presentation and science writing skills.
Accumulation of monoterpenoid indole alkaloids in periwinkle seedlings (Catharanthus roseus) as a model for the study of plant–environment interactions
Authors: Lourdes Miranda‐Ham María de , Islas‐Flores Ignacio , Vázquez‐Flota and Felipe
Published: May 2007

Alkaloids are part of the chemical arsenal designed to protect plants against an adverse environment. Therefore, their synthesis and accumulation are frequently induced in response to certain environmental conditions and are mediated by chemical signals, which are formed as the first responses to the external stimulus. A set of experiments using Catharanthus roseus seedlings is presented to illustrate this interaction. Using the well characterized induction of monoterpenoid indole alkaloid synthesis in response to methyl jasmonate, one chemical mediator; simple and reproducible experiments are proposed to demonstrate this type of plant–environment interaction to plant physiology or biochemistry B.Sc. students. After exposure to the inducer, seedlings are analyzed for alkaloid accumulation and for the increase of tryptophan decarboxylase (TDC) enzyme activity by means of thin layer chromatography, followed by UV spectrophotometry. Alkaloids should increase as a result of the exposure to the inducer, as well as TDC activity, which plays a critical role in channeling carbon skeletons from primary to secondary metabolism in this plant.
Exploring the feasibility of proactive reputations
Authors: Swamynathan Gayatri , Zhao Ben Y. , Almeroth Kevin C.
Published: May 2007

Reputation mechanisms help peers in a peer‐to‐peer system avoid unreliable or malicious peers. In application‐level networks, however, short peer lifetimes mean reputations are often generated from a small number of past transactions. These reputation values are less ‘reliable’, and more vulnerable to bad‐mouthing or collusion attacks. We address this issue by introducing proactive reputations, a first‐hand history of transactions initiated to augment incomplete or short‐term reputation values. We present several mechanisms to generate proactive reputations, along with a statistical similarity metric to measure their effectiveness. Copyright © 2007 John Wiley & Sons, Ltd.
TRIBLER: a social‐based peer‐to‐peer system
Authors: Pouwelse J. A. , Garbacki P. , Wang J. , Bakker A. , Yang J. , Iosup A. , Epema D. H. J. , Reinders M. , van Steen M. R. , Sips H. J.
Published: May 2007

Most current peer‐to‐peer (P2P) file‐sharing systems treat their users as anonymous, unrelated entities, and completely disregard any social relationships between them. However, social phenomena such as friendship and the existence of communities of users with similar tastes or interests may well be exploited in such systems in order to increase their usability and performance. In this paper we present a novel social‐based P2P file‐sharing paradigm that exploits social phenomena by maintaining social networks and using these in content discovery, content recommendation, and downloading. Based on this paradigm's main concepts such as taste buddies and friends, we have designed and implemented the TRIBLER P2P file‐sharing system as a set of extensions to BitTorrent. We present and discuss the design of TRIBLER, and we show evidence that TRIBLER enables fast content discovery and recommendation at a low additional overhead, and a significant improvement in download performance. Copyright © 2007 John Wiley & Sons, Ltd.
Spatiotemporal expression of smooth muscle markers in developing zebrafish gut
Authors: Georgijevic Sonja , Subramanian Yazhini , Rollins Evvi‐Lynn , Starovic‐Subota Olivera , Tang Archie C.Y. , Childs Sarah J.
Published: May 2007

Smooth muscle is important for the contractility and elasticity of visceral organs. The zebrafish is an excellent model for understanding embryonic development, yet due to a lack of appropriate markers, visceral smooth muscle development remains poorly characterized. Here, we develop markers and trace the development of gut and swim bladder smooth muscle in embryonic and juvenile fish. The first smooth muscle marker we detect in the vicinity of the gut is the myoblast marker nonmuscle myosin heavy chain‐b at 50 hours postfertilization (hpf), followed by the early smooth muscle markers SM22α‐b, and α‐smooth muscle actin at 56 and 60 hpf, respectively. Markers of more differentiated smooth muscle, smoothelin‐b and cpi‐17, appear by 3 days postfertilization (dpf). Tropomyosin, a relatively late marker, is first expressed at 4 dpf. We find that smooth muscle marker expression in the swim bladder follows the same sequence of marker expression as the gut, but markers have a temporal delay reflecting the later formation of swim bladder smooth muscle. Developmental Dynamics 236:1623–1632, 2007. © 2007 Wiley‐Liss, Inc.
Xenopus cDNA microarray identification of genes with endodermal organ expression
Authors: Changkyun Park Edmond , Hayata Tadayoshi , Cho Ken W.Y. , Han Jin‐Kwan
Published: May 2007

The endoderm is classically defined as the innermost layer of three Metazoan germ layers. During organogenesis, the endoderm gives rise to the digestive and respiratory tracts as well as associated organs such as the liver, pancreas, and lung. At present, however, how the endoderm forms the variety of cell types of digestive and respiratory tracts as well as the budding organs is not well understood. In order to investigate the molecular basis and mechanism of organogenesis and to identify the endodermal organ‐related marker genes, we carried out microarray analysis using Xenopus cDNA chips. To achieve this goal, we isolated the Xenopus gut endoderm from three different stages of Xenopus organogenesis, and separated each stage of gut endoderm into anterior and posterior regions. Competitive hybridization of cDNA between the anterior and posterior endoderm regions, to screen genes that specifically expressed in the major organs, revealed 915 candidates. We then selected 104 clones for in situ hybridization analysis. Here, we report the identification and expression patterns of the 104 Xenopus endodermal genes, which would serve as useful markers for studying endodermal organ development. Developmental Dynamics 236:1633–1649, 2007. © 2007 Wiley‐Liss, Inc.
Self‐efficacy as a moderator of negative and positive self‐fulfilling prophecy effects: mothers' beliefs and children's alcohol use
Authors: Willard Jennifer , Madon Stephanie , Guyll Max , Spoth Richard , Jussim Lee
Published: May 2007

This research examined two issues relevant to self‐fulfilling prophecies. First, it examined whether children's risk for alcohol use, as indicated by their self‐efficacy to refuse alcohol from peers, moderated their susceptibility to negative and positive self‐fulfilling prophecy effects created by their mothers. Second, it explored behavioral mediators that could be involved in the self‐fulfilling process between mothers and children. Longitudinal data from 540 mother–child dyads indicated that (1) low self‐efficacy children were more susceptible to their mothers' positive than negative self‐fulfilling effects, whereas high self‐efficacy children's susceptibility did not vary, (2) mothers' global parenting and children's perception of their friends' alcohol use partially mediated mothers' self‐fulfilling effects, and (3) these mediators contributed to low self‐efficacy children's greater susceptibility to positive self‐fulfilling prophecy effects. The power of self‐fulfilling prophecies, their link to social problems, and the potential for mothers' favorable beliefs to have a protective influence on adolescent alcohol use are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Measurement uncertainty analysis for calorimetry apparatuses
Authors: Zhao Lei , Dembsey Nicholas A.
Published: May 2007

The absence of a standardized uncertainty analysis methodology for fire calorimetry apparatuses makes significant comparison of test results between fire laboratories difficult. From a testing (pass/fail) perspective, the lack of a common means to estimate the uncertainty is problematic. From a material development viewpoint, the ability to differentiate versions of material systems is uncertain which potentially results in economic penalties for the developer. Probability and statistics methodologies recommended by International Organization for Standardization and National Institute of Standards and Technology were applied to begin developing a standardized measurement uncertainty method for fire calorimetry apparatuses. The method was applied to each component instrument (intrinsic and calibration uncertainty only) and each related physics quantity measured indirectly. Results were reported at the 95% confidence level. The results were compared with various reference cases as well as those from a Monte Carlo Simulation technique modelling the experiments. The consistency verified our measurement uncertainty method. The results for heat release rate and average heat of combustion provide the user of Cone Calorimeter data with the
ability to estimate potential experimental error inherent in the operation of the Cone. This information can be used to make informed decisions related to the matters cited above. Copyright © 2007 John Wiley & Sons, Ltd.
Vorticity–strain residual‐based turbulence modelling of the Taylor–Green vortex
Authors: Bensow R. E. , Larson M. G. , Vesterlund P.
Published: May 2007

This paper describes turbulence properties for a residual‐based turbulence model using fine‐scale approximations of strain and vorticity, emanating from a split of the non‐linear term in the Navier–Stokes equations. We will discuss the modelling of the fine‐scale terms and their impact in the light of simulation results of turbulent transition of the Taylor–Green vortex. Copyright © 2007 John Wiley & Sons, Ltd.
An explicit formulation for the evolution of nonlinear surface waves interacting with a submerged body
Authors: Kent Christopher P. , Choi Wooyoung
Published: May 2007

An explicit formulation to study nonlinear waves interacting with a submerged body in an ideal fluid of infinite depth is presented. The formulation allows one to decompose the nonlinear wave–body interaction problem into body and free‐surface problems. After the decomposition, the body problem satisfies a modified body boundary condition in an unbounded fluid domain, while the free‐surface problem satisfies modified nonlinear free‐surface boundary conditions. It is then shown that the nonlinear free‐surface problem can be further reduced to a closed system of two nonlinear evolution equations expanded in infinite series for the free‐surface elevation and the velocity potential at the free surface. For numerical experiments, the body problem is solved using a distribution of singularities along the body surface and the system of evolution equations, truncated at third order in wave steepness, is then solved using a pseudo‐spectral method based on the fast Fourier transform. A circular cylinder translating steadily near the free surface is considered and it is found that our numerical solutions show excellent agreement with the fully nonlinear solution using a boundary integral method. We further validate our solutions for a submerged circular cylinder oscillating vertically or fixed under incoming nonlinear waves with other analytical and numerical results. Copyright © 2007 John Wiley & Sons, Ltd.
Numerical aspects of improvement of the unsteady pipe flow equations
Authors: Szymkiewicz Romuald , Mitosek Marek
Published: May 2007

The paper presents an analysis of some recently proposed improvements of the water hammer equations, which concern the friction term in the momentum equation. A comparison of the experimental data and numerical results shows that the required damping and smoothing of the pressure wave cannot be obtained by modification of the friction factor only.

In order to evaluate the significance of the introduced improvements into the momentum equation, the accuracy of the numerical solution has been analysed using the modified equation approach. The analysis shows why the physical dissipation process observed in the water hammer phenomenon cannot be reproduced with the commonly used source term in Darcy–Weisbach form, representing friction force in the momentum equation. Therefore, regardless of the proposed form of the friction factor for unsteady flow, the model of water hammer improved in such a way keeps its hyperbolic character. Consequently, it cannot ensure the expected effects of damping and smoothing of the calculation head oscillations. Copyright © 2007 John Wiley & Sons, Ltd.
A stabilized mixed finite element method for Darcy–Stokes flow
Authors: Masud Arif
Published: May 2007

This paper presents a new stabilized finite element method for the Darcy–Stokes equations also known as the Brinkman model of lubrication theory. These equations also govern the flow of incompressible viscous fluids through permeable media. The proposed method arises from a decomposition of the velocity field into coarse/resolved scales and fine/unresolved scales. Modelling of the unresolved scales corrects the lack of stability of the standard Galerkin formulation for the Darcy–Stokes equations. A significant feature of the present method is that the structure of the stabilization tensor τ appears naturally via the solution of the fine‐scale problem. The issue of arbitrary combinations of pressure–velocity interpolation functions is addressed, and equal‐order combinations of C° interpolations are shown to be stable and convergent. Copyright © 2007 John Wiley & Sons, Ltd.
A 3D adaptive mesh moving scheme
Authors: Kanchi Harish , Masud Arif
Published: May 2007

This paper presents an adaptive mesh moving technique for three‐dimensional (3D) fluid flow problems that involve moving fluid boundaries and fluid–solid interfaces. Such mesh moving techniques are an essential ingredient of fluid–structure interaction methods that typically employ arbitrary Lagrangian–Eulerian (ALE) frameworks. In the ALE frame, the velocity field representing motion of the underlying continuum is integrated in the fluid flow equations. In the discretized setting, the velocity field of the underlying continuum gives rise to the mesh displacement field that needs to be solved for in addition to the flow equations and the structural equations. Emphasis in the present work is on the motion and deformation of 3D grids that are composed of linear tetrahedral and hexahedral elements in structured and unstructured configurations. The proposed method can easily be extended to higher‐order elements in 3D. A variety of moving mesh problems from different fields of engineering are presented that show the range of applicability of the proposed method and the class of problems that can be addressed with it. Copyright © 2007 John Wiley & Sons, Ltd.
The adjoint weighted equation for steady advection in a compressible fluid
Authors: Oberai Assad A. , Barbone Paul E. , Harari Isaac
Published: May 2007

An alternative variational framework suitable for pure advection is obtained by discarding the Galerkin part of stabilized methods. The resulting scheme is similar to the least‐squares approach, but with the adjoint operator in the weighting slot. This formulation is not restricted to solenoidal (i.e. divergence free) velocities. Initial numerical results for such problems show that the method is promising. Copyright © 2007 John Wiley & Sons, Ltd.
Characterizing hydrodynamics on boreal landscapes using archived synthetic aperture radar imagery
Authors: Sass G. Z. , Creed I. F.
Published: May 2007

Characterizing the spatial and temporal variation in surface hydrological dynamics of large boreal landscapes is vital, since these patterns define the occurrence of key areas of land‐to‐lake and land‐to‐atmosphere hydrological and biogeochemical linkages that are critical in the movement of matter and energy at local to global scales. However, monitoring surface hydrological dynamics over large geographic extents and over long periods of time is a challenge for hydrologists, as traditional point measurements are not practical. In this study we used European Remote Sensing satellite radar imagery to monitor the variation in surface hydrological patterns over a 12‐year period and to assess the change in the organization of saturated and inundated areas of the landscape. Using the regional Utikuma River drainage basin (2900 km2) as the test area, the analyses of patterns of wetlands indicated that, during dry climatic conditions, wetland sizes were small and disconnected from each other and receiving bodies of water. As climatic conditions changed from dry to mesic, wetland numbers increased but were still disconnected. Very wet climatic conditions were required before the disconnected wetlands coalesced and connected to lakes. During these wet conditions, the response of the lake level at Utikuma Lake was observed to be much higher than under drier conditions. Analyses of individual wetland maps and integrated wetland probability maps have the potential to inform future biogeochemical and ecological investigations and forest management on the Boreal Plain. Copyright © 2007 John Wiley & Sons, Ltd.
Loss of α6 integrins in keratinocytes leads to an increase in TGFβ and AP1 signaling and in expression of differentiation genes
Authors: Rodius Sophie , Indra Gitali , Thibault Christelle , Pfister Véronique , Georges‐Labouesse Elisabeth
Published: May 2007

Mice lacking the α6 integrin chain die at birth with severe skin blistering. To further study the function of α6 integrin in skin, we generated conditionally immortalized cell lines from the epidermis of wild‐type and α6 deficient mouse embryos. Mutant cells presented a decreased adhesion on laminin 5, the major component of the basement membrane in the skin, and on laminins 10/11 and 2. A DNA array analysis revealed alterations in the expression of extracellular matrix (ECM) components including laminin 5, cytoskeletal elements, but also membrane receptors like the hemidesmosomal components integrin β4 and collagen XVII, or growth factors and signaling molecules of the TGFβ, EGF, and Wnt pathways. Finally, an increase of several epidermal differentiation markers was observed in cells and tissue at the protein level. Further examination of the mutant tissue revealed alterations in the filaggrin signal. These differences may be linked to an upregulation of the TGFβ and the Jun/Fos pathways in mutant keratinocytes. These results are in favor of a role for integrin α6β4 in the maintenance of basal keratinocyte properties and epidermal homeostasis. J. Cell. Physiol. 212: 439–449, 2007. © 2007 Wiley‐Liss, Inc.
GADD45A is a mediator of CD437 induced apoptosis in ovarian carcinoma cells
Authors: Jiang Tianying , Soprano Dianne Robert , Soprano Kenneth J.
Published: May 2007

Ovarian cancer is one of the leading causes of cancer death in women. A number of studies have suggested that synthetic retinoids may play an important role as an ovarian cancer chemotherapeutic agent. The synthetic retinoid CD 437 induces apoptosis in ovarian tumor cells by a mechanism that is not completely understood. In this study we demonstrate that CD437 treatment leads to an increase in GADD45A and GADD45B mRNA expression in CA‐OV3 cells but not in CA‐CD437R cells, a cell line which is resistant to CD437. This induction is specific to CD437 since no change in expression of either GADD45A or GADD45B was observed with either all‐trans‐RA or 4‐HPR treatment. Western blot analysis demonstrated that the induction of GADD45A mRNA in the CA‐OV3 cell line by CD437 was accompanied by an increase in GADD45A protein. Upregulation of GADD45A by CD437 is regulated at least in part at the post‐transcriptional level. In contrast, CD437 regulates GADD45B expression by different mechanisms. The importance of GADD45A induction in mediating apoptosis was demonstrated in CA‐OV3 cells overexpressing GADD45A antisense RNA (GADD45A‐AS cells). Our results suggest that induction of GADD45A expression might play a role in mediating the apoptotic response of ovarian cancer cells to the synthetic retinoid CD437. J. Cell. Physiol. 212:771–779, 2007. © 2007 Wiley‐Liss, Inc.
Sperm surface arylsulfatase A can disperse the cumulus matrix of cumulus oocyte complexes
Authors: Wu Alexander , Anupriwan Araya , Iamsaard Sitthichai , Chakrabandhu Krittalak , Santos Daniela Costa , Rupar Tony , Tsang Benjamin K. , Carmona Euridice , Tanphaichitr Nongnuj
Published: May 2007

Cumulus cell layers of expanded cumulus oocyte complexes (COCs) are interlinked with networks of hyaluronic acid, chondroitin sulfate B proteoglycans and link proteins, and they can be dispersed by sperm surface hyaluronidases. In this report, we showed that arylsulfatase A (AS‐A), existing on the sperm head surface, also had this dispersion action. Purified AS‐A free of protease, hyaluronidase and chondroitinase activities could disperse the cumulus matrix of expanded COCs. However, this COC dispersion action was not associated with AS‐A desulfation activity, assayed by using p‐nitrocatecholsulfate (artificial substrate). COCs incubated for 1 h with sperm pretreated with anti‐AS‐A IgG in the presence of apigenin (a hyaluronidase inhibitor) did not exhibit matrix dispersion, whereas several cumulus layers were already dispersed in COCs incubated with sperm pretreated with preimmune IgG. Furthermore, sperm from AS‐A null mice showed a significant delay in COC dispersion, compared with wild‐type sperm. Within 1 h of sperm‐COC co‐incubation, the size of COCs incubated with AS‐A null sperm was 65% of the original dimension, whereas that of COCs inseminated with wild‐type sperm was only 17%. A further delay in COC dispersion by AS‐A(−/−) mouse sperm was observed when apigenin was present in the co‐incubation. We also showed for the first time that AS‐A had a specific affinity for chondroitin sulfate B, a component of cumulus matrix proteoglycan networks; this might provide a mechanism of cumulus matrix destabilization induced by sperm surface AS‐A. J. Cell. Physiol. 213: 201–211, 2007. © 2007 Wiley‐Liss, Inc.
Inhibition of HIV‐1 multiplication by a modified U7 snRNA inducing Tat and Rev exon skipping
Authors: Asparuhova Maria B. , Marti Gabriela , Liu Songkai , Serhan Fatima , Trono Didier , Schümperli Daniel
Published: May 2007

The HIV‐1 regulatory proteins Tat and Rev are encoded by multiply spliced mRNAs that differ by the use of alternative 3' splice sites at the beginning of the internal exon. If these internal exons are skipped, the expression of these genes, and hence HIV‐1 multiplication, should be inhibited. We have previously developed a strategy, based on antisense derivatives of U7 small nuclear RNA, that allows us to induce the skipping of an internal exon in virtually any gene. Here, we have successfully applied this approach to induce a partial skipping of the Tat, Rev (and Nef) internal exons. Three functional U7 constructs were subcloned into a lentiviral vector. Two of them strongly reduced the efficiency of lentiviral particle production compared to vectors carrying either no U7 insert or unrelated U7 cassettes. This defect could be partly or fully compensated by coexpressing Rev from an unspliced mRNA in the producing cell line. Upon stable transduction into CEM‐SS or CEM T‐lymphocytes, the most efficient of these constructs inhibits HIV‐1 multiplication. Although the inhibition is not complete, it is more efficient in combination with another mechanism inhibiting HIV multiplication. Therefore, this new approach targeting HIV‐1 regulatory genes at the level of pre‐mRNA splicing, in combination with other antiviral strategies, may be a useful new tool in the fight against HIV/AIDS. Copyright © 2007 John Wiley & Sons, Ltd.
In vivo expression of human ATP:cob(I)alamin adenosyltransferase (ATR) using recombinant adeno‐associated virus (rAAV) serotypes 2 and 8
Authors: Erger Kirsten E. , Conlon Thomas J. , Leal Nicole A. , Zori Robert , Bobik Thomas A. , Flotte Terence R.
Published: May 2007

Background

Methylmalonic aciduria (MMA) is an autosomal recessive disease with symptoms that include ketoacidosis, lethargy, recurrent vomiting, dehydration, respiratory distress, muscular hypotonia and death due to methylmalonic acid levels that are up to 1000‐fold greater than normal. CblB MMA, a subset of the mutations leading to MMA, is caused by a deficiency in the enzyme cob(I)alamin adenosyltransferase (ATR). No animal model currently exists for this disease. ATR functions within the mitochondria matrix in the final conversion of cobalamin into coenzyme B12, adenosylcobalamin (AdoCbl). AdoCbl is a required coenzyme for the mitochondrial enzyme methylmalonyl‐CoA mutase (MCM).

Methods

The human ATR cDNA was cloned into a recombinant adeno‐associated virus (rAAV) vector and packaged into AAV 2 or 8 capsids and delivered by portal vein injection to C57/Bl6 mice at a dose of 1 × 1010 and 1 × 1011 particles. Eight weeks post‐injection RNA, genomic DNA and protein were then extracted and analyzed.

Results

Using primer pairs specific to the cytomegalovirus (CMV) enhancer/chicken β‐actin (CBAT) promoter within the rAAV vectors, genome copy numbers were found to be 0.03, 2.03 and 0.10 per cell in liver for the rAAV8 low dose, rAAV8 high dose and rAAV2 high dose, respectively. Western blotting performed on mitochondrial protein extracts demonstrated protein levels were comparable to control levels in the rAAV8 low dose and rAAV2 high dose animals and 3‐ to 5‐fold higher than control levels were observed in high dose animals. Immunostaining demonstrated enhanced transduction efficiency of hepatocytes to over 40% in the rAAV8 high dose animals, compared to 9% and 5% transduction in rAAV2 high dose and rAAV8 low dose animals, respectively.

Conclusions

These data demonstrate the feasibility of efficient ATR gene transfer to the liver as a prelude to future gene therapy experiments. Copyright © 2007 John Wiley & Sons, Ltd.
Switching on transgene expression by correcting aberrant splicing using multi‐targeting steric‐blocking oligonucleotides
Authors: Resina Sarah , Kole Ryszard , Travo Adrian , Lebleu Bernard , Thierry Alain R.
Published: May 2007

Background

Mutations leading to aberrant splicing are found as a cause of numerous pathologies. Splice‐switching oligonucleotides (SSOs), which modify aberrant expression patterns of alternatively spliced mRNAs, are a novel means of potentially controlling such diseases.

Methods

We used an experimental model in which a mutated β‐globin intron, carrying an aberrant splice site at nucleotide 705, interrupts the coding region of the luciferase reporter gene inserted in HeLa pLuc/705 cells. We have optimized delivery of splice correcting, steric‐blocking 2′‐O‐methyl SSOs targeting the 705 mutated region (2′‐O‐Me SSO705) with DLS (DLS: delivery liposomal system) lipoplexes.

Results

Optimal luciferase activity for DLS/2′‐O‐Me SSO705 was achieved at 100 nM and was detectable at concentrations as low as 10 nM in serum‐containing culture medium, confirming the potential of DLS lipoplex‐mediated nuclear SSO delivery as observed in cellular uptake studies. We confirmed by cytofluorometry and epifluorescence microscopy the high potential of the DLS lipoplex for cellular and nuclear oligonucleotide uptake. The DLS lipoplex was then used to directly compare the intracellular efficacy of various SSO chemistries and sequences in correction of aberrant splicing. 2′‐O‐Methoxyethyl‐oligodeoxyribonucleoside phosphorothioates had a greater activity than 2′‐O‐methyl phosphodiester or 2′‐O‐methyl‐phosphorothioate oligoribonucleotides. Targeting the splicing enhancer 623 region upstream was as efficient as targeting the 705 splice site, and, remarkably, simultaneous targeting of both sites was more efficient than treatment of the cells either with 2′‐O‐Me SSO705 or 2′‐O‐Me SSO623 alone.

Conclusions

We demonstrated that SSOs can switch on luciferase activity in HeLa cells previously transfected with the pLuc/705 plasmid via the same DLS vector and provides a novel approach to modulate the expression of a transgene. Copyright © 2007 John Wiley & Sons, Ltd.
Human osteocalcin: a strong promoter for nitric oxide synthase gene therapy, with specificity for hormone refractory prostate cancer
Authors: McCarthy Helen O. , Coulter Jonathan A. , Worthington Jenny , Robson Tracy , Hirst David G.
Published: May 2007

Background

Gene therapy has been identified as a promising treatment strategy for hormone refractory prostate cancer (HRPC). We report, for the first time, the use of the human osteocalcin (hOC) promoter to control inducible nitric oxide synthase (iNOS) transgene expression in HRPC.

Methods

Human prostate carcinoma cells (PC3, DU145, LNCaP), colon cancer cells (HT29) and human microvascular endothelial cells (HMEC‐1) were transfected in vitro with constitutively driven CMV/iNOS or hOC/iNOS plasmid DNA by cationic lipid vector. End points of these experiments were Western blotting, NO· generation using the Greiss test to measure accumulated nitrite, and clonogenic assay.

Results

Transfection of the hOC/iNOS plasmid increased iNOS protein and total nitrite levels in PC3 and DU145 cells, but not LNCaP or HT29. Transfection with CMV/iNOS or hOC/iNOS resulted in no additional cytotoxicity in androgen‐dependent LNCaP cells or in the non‐prostate cell lines. However, transfection with either construct resulted in a greatly reduced cell survival (to 10–20%) in the androgen‐independent PC3 and DU145 cell lines.

Conclusions

Utilising the tumour‐type specific properties of the hOC promoter in tandem with the iNOS gene, we have demonstrated target cell specificity, and transgene activation, in the androgen‐independent prostate cancer cell lines (PC3 and DU145), an effect absent in normal and androgen‐dependent cells. Furthermore, the levels of NO· generated are comparable with those seen generated with constitutively (CMV)‐driven iNOS. The data obtained from this study provide a basis for future development of hOC/iNOS gene therapy. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of cDNA and genomic forms of tyrosine hydroxylase gene therapy of the brain with Trojan horse liposomes
Authors: Xia Chun‐Fang , Chu Chun , Li Jianyi , Wang Yuntao , Zhang Yun , Boado Ruben J. , Pardridge William M.
Published: May 2007

Background

The present study examines whether chromosomal derived forms of therapeutic genes can be delivered to brain following intravenous administration. The brain expression of a rat tyrosine hydroxylase (TH) cDNA is compared to the brain expression of a plasmid DNA encoding the 18 kb rat TH gene.

Methods

TH gene expression is measured in cell culture and in vivo in brain in experimental Parkinson's disease (PD). A total of four eukaryotic expression plasmids encoding rat TH were engineered wherein the size of the TH expression cassette ranged from 1.5 kb, in the case of the cDNA form of the gene, to 17.5 kb, in the case of the largest size genomic construct. The TH expression plasmids were delivered to either cultured cells or to rat brain in vivo with Trojan horse liposomes (THLs), which target the non‐viral plasmid DNA to cells via cell membrane receptors.

Results

The pattern of TH gene expression in cell culture and in vivo was similar: the cDNA form of the TH gene was fast‐acting with short duration of action, and the genomic form of the TH gene was slow‐acting with longer duration of action. The most sustained replacement of striatal TH enzyme activity in experimental PD was produced by combination gene therapy where both the cDNA and the genomic forms of the TH gene were administered simultaneously.

Conclusions

Eukaryotic expression plasmids encoding genomic forms of therapeutic genes, as large as 18 kb, can be successfully incorporated in THLs and delivered to brain following intravenous administration. Copyright © 2007 John Wiley & Sons, Ltd.
The application of electrospray ionization coupled to ultrahigh resolution mass spectrometry for the molecular characterization of natural organic matter
Authors: Sleighter Rachel L. , Hatcher Patrick G.
Published: May 2007

Mass spectrometry has recently played a key role in the understanding of natural organic matter (NOM) by providing molecular‐level details about its composition. NOM, a complex assemblage of organic molecules present in natural waters and soils/sediments, has the ability to bind and transport anthropogenic materials. An improved understanding of its composition is crucial in order to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles. In the past, low‐resolution (>3000) mass analyzers have offered some insights into the structure of NOM, but emerging ultrahigh resolution (>200 000) techniques such as electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR‐MS) have significantly advanced our knowledge of NOM chemistry. Here, a review of the recent literature on the advancements of NOM characterization and the applications of mass spectrometry to this central task is presented. Various methods for the analysis and display of the extremely complex mass spectra, such as the van Krevelen diagram and Kendrick mass defect analysis, are discussed. We also review tandem mass spectrometry techniques employed to gain structural information about NOM components. Finally, we show how ESI‐FT‐ICR‐MS has been applied to examine specific issues that are important to the NOM scientific community, such as NOM reactivity, transport and fate, degradation, and existence of components, which are indicators of NOM origin. In general, ultrahigh resolution provided by FT‐ICR‐MS is essential for the complete separation of the thousands of peaks present in the complex NOM mixture and will clearly lead to additional future advancements in the areas of aquatic, soil, and analytical chemistry. Copyright © 2007 John Wiley & Sons, Ltd.
Gastrojejunostomy versus stent placement in patients with malignant gastric outlet obstruction: a comparison in 95 patients
Authors: Jeurnink S.M. , Steyerberg E.W. , Hof G. van 'T , van Eijck C.H.J. , Kuipers E.J. , Siersema P.D.
Published: May 2007

Aim

Gastrojejunostomy (GJJ) and duodenal stent placement are the most commonly used palliative treatment modalities for gastric outlet obstruction (GOO). In this retrospective study, we compared GJJ and stent placement with regard to medical effects.

Methods

Medical records of 95 patients who had undergone palliative treatment between 1994 and 2006 in a Dutch university hospital, were reviewed. Study outcomes were improvement of food intake, complications, persistent and recurrent symptoms, re‐interventions, hospital stay, and survival.

Results

Fifty‐three patients were referred for duodenal stent placement and 42 patients underwent GJJ. There were no differences in technical and clinical success and the incidence of minor and early major complications and survival. Food intake improved more rapidly after stent placement than GJJ (P = 0.01). The time to late major complications, recurrent obstructive symptoms and re‐intervention was significantly shorter after stent placement than GJJ (P = 0.004, 0.002, and 0.004, respectively). Hospital stay was also shorter after stent placement than GJJ (P < 0.001).

Conclusion

These findings suggest that stent placement is associated with better short‐term outcomes and GJJ with better long‐term outcomes. A large randomized controlled trial is however needed to systematically compare stent placement with GJJ with regard to medical effects, quality of life and costs. J. Surg. Oncol. 2007;96:389–396. © 2007 Wiley‐Liss, Inc.
Uniqueness Theorems for the Frankl‐Morawetz Problem in R2 for a Class of Nonlinear Equations of Mixed Type
Authors: Aziz A. K. , Schneider M.
Published: May 2007

We consider the question of uniqueness for the solutions of the boundary value problem
urn:x-wiley:0025584X:mana19861250115:equation:mana19861250115-math-0001 where sgn K(y) = sgn y and Γ0 and Γ1 are parts of the boundary of a bounded simply connected region G in R2. G is bounded for y > 0 by a piecewise smooth curve Γ0 which intersects the line y = 0 at A (– 1, 0) and B(0, 0). For y < 0 G is bounded by a piecewise smooth curve Γ1 through A, which meets the characteristic of (1) issued from B at point C, and by the curve Γ2 which consists of the portion CB of the characteristic through B.

Using energy‐integral considerations, we give sufficient conditions for the uniqueness of solutions to boundary value problem (1).
On Almost Sure Behavior of Sums of Independent Banach Space Valued Random Variables
Authors: Mikosch T. , Norvaiša R.
Published: May 2007

Levy's strong law of large numbers is extended to the Banach space and Chover type laws of the iterated logarithm are proved for random variables which do not necessarilly belong to the domain of normal attraction of a stable law. Also characterizations of Banach spaces in which conditions on the summands imply the above strong laws are given.
Quantum Fields as Pointlike Localized Objects
Authors: Rehberg Joachim , Wollenberg Manfred
Published: May 2007

We show that Wightman fields are always well defined objects at each space‐time point in the meaning of sesquilinear forms. These sesquilinear forms “sandwiched” with e–cH (H is the energy operator) are closable operators. We use these results to extend some assertions of Fredenhagen and Hertel about the recovering of Wightman fields from a Haag‐Kastler theory of local observables.
On Some Inequalities for Poisson Networks
Authors: Mecke J.
Published: May 2007

A stationary Poisson hyperplane process in Rd induces a random network of (d‐2)‐flats, each of which is the intersection of two hyperplanes of the process. It is known that the intensity of the induced (d‐2)‐flat process divided by the square of the intensity of the original hyperplane process is maximal in the isotropic case. An integral‐geometric formula for elliptic spaces is presented, from which the mentioned extremum property and related inequalities for superpositions of stationary Poisson hyperplane processes are derived.
Spinoren in statischen Raum‐Zeiten
Authors: Illge Reinhard
Published: May 2007

In this paper, a spinor algebra and analysis adapted to static space‐times is presented. Suitable SU(2)‐bases are choosen in spinor space and it is shown, how these bases determine orthogonal systems in (three‐dimensional) space. Some theorems on the curvature spinors of static space‐times are proved by the help of the calculus of the connection spinors. The internal structure of the WEYL spinor as well as its connection with the RICCI tensor of the underlying (three‐dimensional) space are examined. The presented calculus allows the computation of the NEWMAN‐PENROSE spin coefficients and the canonical normal 1‐spinors of the WEYL spinor with a relatively small expense, which is demonstrated on a sequence of examples.
Lösungsverzweigung bei analytischen Gleichungen mit Fredholm‐Operator von Index Null
Authors: Heinz Günter
Published: May 2007

The bifurcation of a solution of the equationf(x, λ) = 0 at the point (x0, λ0) is investigated. In the case thatB: = –fx(x0, λ0) is a FREDHOLM operator by the method of LJAPUNOV/SCHMIDT the original equation is equivalent to a system consisting of a locally uniquely solvable equation and an equation in a finit dimensional subspace, the so‐called bifurcation equation. For analytical/recursion formulas are deduced to determine the locally unique solution. In the case of FREDHOLM operatorsBwith index zero practicable criteria are given for the applicability of a theorem of IZE being a generalization of a well known theorem of KRASNOSELSKIJ.
A Sheaf Property for Excessive Functions of Right Processes
Authors: Steffens J.
Published: May 2007

On a state space of a right process a facial topology depending upon some RAY compactification is introduced. With respect to this facial topology the right process is shown to exhibit a nice path behaviour. Furthermore, conditions are given which permit a local characterization of excessive functions with respect to the facial topology. This result gives a partial answer to an open question within the potential theory of H‐cones.
Totally Incomparable Banach Spaces and Three‐Space Banach Space Ideals
Authors: Alvarez Teresa , Gonzalez Manuel , Onieva Victor M.
Published: May 2007

In this paper we present four methods to generate three‐space BANACH space ideals. They are based on the concept of total incomparability of H. P. ROSENTHAL and on a dual concept, total coincomparability, which is here introduced. We use the assertion that the sum of two totally incomparable closed subspaces of a BANACH space is norm‐closed, which is shown by means of an easier and more natural proof than that of ROSENTHAL [10], and an analogous property about the total coincomparability. Several well‐known ideals are obtained with the above methods, and so they are three‐space ideals.
Polyhedron Theorems for Non‐Smooth Cell Complexes
Authors: Zähle M.
Published: May 2007

Results like EULER'S polyhedron theorem or relations for the EULER characteristic are extended to signed curvature measures of p‐dimensional topological polyhedra in Rd. The cells are assumed to be finite unions of compact manifolds with boundary and positive reach.

By means of generalized unit normal bundles and generalized principal curvatures provided with a certain set additive index function the global problems can be reduced to local variants.
The Extended Probability Generating Functional, with Application to Mixing Properties of Cluster Point Processes
Authors: Daley D. J. , Vere‐Jones D.
Published: May 2007

An extended probability generating functional (p. g. fl.)\documentclass{article}\pagestyle{empty}\begin{document}$ \bar{G}[h]\; = \;E\;\left({\exp \;\int\limits_x {\log } \;h(x)\; \times \;N(dx)} \right) $\end{document}is well‐defined for any point processNon the complete separable metric space χ over the space V̄0of measurable functionsh: χ → (0, 1) such that infxcHh(x) > 0. The distribution ofNis determined uniquely by the p.g.fl.G[h] ≡ Ḡ[h] over the smaller spaceV0of functionshε V̄0for which 1 —hhas bounded support. Continuity results for Ḡ[·] involving pointwise convergent sequences {hn}V0or V̄0or V̄ ≡ {measurableh: χ → [0, 1]} orV= {hε V̄: 1 —hhas bounded support} are reviewed, and used in furnishing a complete p. g. fl. proof of the mixing property of certain stationary cluster processes.