bluuebunny/crossref_metadata_2025 huggingface dataset:
A non‐existence result on Cameron–Liebler line classes
Authors: De Beule J. , Hallez A. , Storme L.
Published: June 2007

Cameron–Liebler line classes are sets of lines in PG(3, q) that contain a fixed number x of lines of every spread. Cameron and Liebler classified Cameron–Liebler line classes for x ∈ {0, 1, 2, q2 − 1, q2, q2 + 1} and conjectured that no others exist. This conjecture was disproven by Drudge for q = 3 [8] and his counterexample was generalized to a counterexample for any odd q by Bruen and Drudge [4]. A counterexample for q even was found by Govaerts and Penttila [9]. Non‐existence results on Cameron–Liebler line classes were found for different values of x. In this article, we improve the non‐existence results on Cameron–Liebler line classes of Govaerts and Storme [11], for q not a prime. We prove the non‐existence of Cameron–Liebler line classes for 3 ≤ x < q/2. © 2007 Wiley Periodicals, Inc. J Combin Designs 16: 342–349, 2008
Two new infinite families of extremal class‐uniformly resolvable designs
Authors: Dinitz J.H. , Ling Alan C.H.
Published: June 2007

In 1991, Lamken et al. [7] introduced the notion of class‐uniformly resolvable designs, CURDs. These are resolvable pairwise balanced designs PBD(v, K, λ) in which given any two resolution classes C and C', for each k ∈ K the number of blocks of size k in C is equal to the number of blocks of size k in C'. Danzinger and Stevens showed that if a CURD has v points, then v ≤ (3p3)2 and v ≤  (p2)2 where pi denotes the number of blocks of size i for i = 2, 3. They then constructed an infinite class of extremal CURDs with v = (3p3)2 when p3 is odd and an infinite class with v = (p2)2 when p2 ≡ 2 (mod 6). In this note, we construct two new infinite families of extremal CURDs, when v = (3p3)2 for all p3 ≥ 1 and when v = (p2)2 with p2 ≡ 0 (mod 3) except possibly when p2 = 12. © 2007 Wiley Periodicals, Inc. J Combin Designs 16: 213–220, 2008
Designed electromagnetic pulsed therapy: Clinical applications
Authors: Gordon Glen A.
Published: June 2007

First reduced to science by Maxwell in 1865, electromagnetic technology as therapy received little interest from basic scientists or clinicians until the 1980s. It now promises applications that include mitigation of inflammation (electrochemistry) and stimulation of classes of genes following onset of illness and injury (electrogenomics). The use of electromagnetism to stop inflammation and restore tissue seems a logical phenomenology, that is, stop the inflammation, then upregulate classes of restorative gene loci to initiate healing. Studies in the fields of MRI and NMR have aided the understanding of cell response to low energy EMF inputs via electromagnetically responsive elements. Understanding protein iterations, that is, how they process information to direct energy, we can maximize technology to aid restorative intervention, a promising step forward over current paradigms of therapy. J. Cell. Physiol. 212:579–582, 2007. © 2007 Wiley‐Liss, Inc.
Biological and Optical Properties of Fluorescent Nanoparticles Developed for Intravascular Imaging
Authors: Ravnic Dino J. , Zhang Yu‐Zhong , Turhan Aslihan , Tsuda Akira , Pratt Juan P. , Huss Harold T. , Mentzer Steven J.
Published: June 2007

Intravascular tracers in the blood circulation can provide a description of the flow field over time and space. To address the limitations of existing intravascular tracers, we have developed fluorescent nanoparticles capable of providing detailed information regarding the intravascular flow field. The nanoparticles were designed to maximize plasma half‐life as well as minimize interactions with other blood components. The bioavailability of the particles in the blood circulation required nanoscale size and low surface charge density. Intravital imaging of nanoparticles in the microcirculation demonstrated that the fluorescence intensity of the nanoparticles was a major determinant of both temporal and spatial resolution of the flow field. We conclude that nanoparticles prepared with these physical and optical properties can provide an accurate description of the localized intravascular flow field. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
A New Method for the Treatment of Sperm Samples for Ultrastructural Study Based on the Use of Animal Tissues as Biological Containers
Authors: Junquera Concepción , Colás Carmen , Martínez‐Ciriano Carmen , Serrano Pedro , Castiella Tomás , Cebrian‐Perez José Alvaro , Muiño‐Blanco Teresa
Published: June 2007

The study of the ultrastructure of spematozoa by means of transmission electron microscopy often presents with problems of interpretation according to the method employed, depending on whether samples are either centrifuged previously to the fixation or immersed in viscous gels. The major problems of interpretation are: changes in the location of vesicles originated during the maturation process and modifications in the adsorption of seminal plasma proteins to the sperm membrane surface. The aim of our study is to communicate an original new method for the treatment of spermatozoa for ultrastructural study. Our method is based on the use of animal tissues as biological containers, inside which the spermatic suspensions are included. We developed this method using fresh sperm samples taken from mature Rasa aragonesa rams. As biological container, we used 2.5‐cm long segments of the intestine of 1‐week‐old chickens (Gallus gallus) (diameter around 4 mm). To avoid any influence of digestive enzymes of the mucosa on the sperm surface, we put each intestine fragment inside out by means of microdissection forceps under bifocal optical microscope and cold light. One of the edges was tied with thin suture silk. The sperm suspension was injected in the optimal experimental condition and amount. Finally, the still open edge of the intestine segment was tied with silk in the same way as the other segment edge. By using this technique, we can perform a suitable morphological study at an ultrastructural level. In addition, the functional relationship of the ultrastructural components of the target cells is correctly preserved. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
The Use of Er:YAG Laser for Cavity Preparation: An SEM Evaluation
Authors: Freitas Patricia Moreira , Navarro Ricardo Scarparo , Barros Juliana Almeida , Eduardo Carlos De Paula
Published: June 2007

Objective: The purpose of this study was to evaluate morphological changes in cavities prepared by the Er:YAG laser (2.94 μm) at different parameters of irradiation and by a diamond bur. Experimental design: Cavities were prepared on 27 human molars (n = 3): G1, 15 Hz/160 mJ enamel/6 Hz/200 mJ dentin; G2, 15 Hz/180 mJ enamel/6 Hz/200 mJ dentin; G3, 15 Hz/160 mJ enamel/6 Hz/250 mJ dentin; G4, 15 Hz/180 mJ enamel/6 Hz/250 mJ dentin; G5, 15 Hz/180 mJ enamel/10 Hz/180 mJ dentin; G6, 15 Hz/160 mJ enamel/10 Hz/180 mJ dentin; G7, 15 Hz/160 mJ enamel/10 Hz/160 mJ dentin; G8, 15 Hz/180 mJ enamel/10 Hz/160 mJ dentin; G9, diamond bur. For SEM analysis, samples were fixed (2.5% glutaraldheyde, 12 h, 4°C), dehydrated (25–100% ethanol), dried, and sputter‐coated with gold. Results: Despite the changes on energy and repetition‐rate settings, all laser‐treated samples showed no evidence of thermal damage or signs of burning and melting. Er:YAG laser ablated dental hard tissues showed exposed enamel prisms, dentin surface without smear layer, and opened dentinal tubules. Conclusion: Different Er:YAG laser parameters were effective for ablation of hard tissues, creating an irregular and microretentive morphological pattern without hard tissue damage. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Comparative Ultrastructural Analyses of Mouse, Rabbit, and Human Platelets and Fibrin Networks
Authors: Pretorius E. , Humphries P. , Ekpo O.E. , Smit E. , van der Merwe C.F.
Published: June 2007

Platelets and fibrin play an important role in the coagulation process, where they are involved in the maintenance of hemostasis. Fibrin dysfunction is associated with the development of vascular complications, while proneness to the formation of tight and rigid fibrin networks is independently associated with thrombotic disease. Here we investigate the ultrastructure of human, rabbit, and mouse platelets and fibrin networks, using the scanning electron microscope. Human and rabbit fibrin and platelets, with regards to morphology as well as size of major and minor fibers compare well with each other. However, mouse fibers are much thinner and form a flimsy branching network. Platelet aggregate morphology of all three species compare well with each other. We conclude that rabbit platelet and fibrin networks could be used successfully when studying the effect of pharmaceutical products in preclinical trials, when looking at the effects of these products on morphology and ultrastructure. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Comparative Morphology of Leaf Epidermis in Eight Populations of Atlas Pistachio (Pistacia atlantica Desf., Anacardiaceae)
Authors: Belhadj Safia , Derridj Arezki , Aigouy Thierry , Gers Charles , Gauquelin Thierry , Mevy Jean‐Philippe
Published: June 2007

A comparative analysis was undertaken to conduct a micromorphological study of Pistacia atlantica leaves by comparing different populations grown under different climatic conditions. Leaf epidermis of eight wild populations was investigated under scanning electron microscope. Micromorphological characteristics (epidermis ornament, stomata type, waxes as well as trichomes) of the adaxial and abaxial leaf surfaces were examined. The epidermis ornament varied among populations and leaf surface, the abaxial leaf surface is reticulate with a striate surface. Messaad site shows a smooth uneven surface. The adaxial leaf surface is smooth but several ornamentations can be seen. The leaflet is amphistomatic; the stomata appeared to be slightly sunken. A variety of stomatal types were recorded; actinocytic and anomocytic types are the most frequent. The indumentum consisted of glandular and nonglandular trichomes. Unicellular glandular trichomes are recorded for P. atlantica leaves in this study. Their density is higher in Oued safene site, located at the highest altitude in comparison with the other populations. The wax occurred in all the sites and its pattern varied according to the populations studied, particularly between Berriane and Messaad. The morphological variability exhibited by the eight populations of P. atlantica may be interpreted as relevant to the ecological plasticity and the physiological mechanisms involved are discussed in this report. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Novel Sample Preparation Method of Polymer Emulsion for SEM Observation
Authors: Xu Jing , Hou Zhaosheng , Li Tianduo
Published: June 2007

The aim of this study was to design a simple and reliable method for obtaining the detailed information about the average size, size distribution, and the surface morphology of particles with variation of the sample preparation of a polymer emulsion. In this work, the characteristic features of the particles of rosin size with high viscosity were first described by scanning electron microscopy (SEM). The morphologies of polymer emulsion of solid lipid nanoparticles and of the microspheres were observed. The advantage of the method is that not only the true size and shape of emulsion particles can be shown, but the problem of high‐viscosity emulsion that prevents there study with SEM is solved. Using this new method, the micromorphology and size distribution of the emulsion particles with different viscosities have been clearly observed. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Mucin Coatings Suppress Neutrophil Adhesion to a Polymeric Model Biomaterial
Authors: Sandberg Tomas , Carlsson Jan , Ott Marjam Karlsson
Published: June 2007

Following our recent study on the fractionation, characterization, and model adsorption of mucins derived from bovine salivary glands (BSM), porcine stomach scrapings (PGM), and human whole saliva (MG1), we here present a microscopic evaluation of the interactions between mucin‐coated substrates and human neutrophils. Our results show that surface‐coating with BSM, PGM, and MG1 can be effectively used to suppress the adhesion of neutrophils to a polymeric model biomaterial (Thermanox). Neutrophil morphologies found on Thermanox substrates coated with mucins resemble those observed for nonactivated neutrophils found in circulation. Notably, low neutrophil adhesion can be obtained at a significantly lower coating concentration (0.125 mg/mL) for the compositionally complex MG1 mucin than for the relatively pure BSM and PGM mucins (1 mg/mL). Furthermore, since coating at a low BSM and PGM concentration (0.25 mg/mL) results in higher cell counts and more spread cells than in the high‐concentration case, we suggest that dense mucin surface packing is critical for good coating performance. In conclusion, the present study demonstrates how mucins from three different sources, of different compositional and structural status, efficiently can be used to suppress neutrophil adhesion and activation. This finding makes them potent candidates for use as biomaterial coatings. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Incubation temperature modifies neonatal thermoregulation in the lizard Anolis carolinensis
Authors: Goodman Rachel M. , Walguarnery Justin W.
Published: June 2007

The thermal environment experienced during embryonic development can profoundly affect the phenotype, and potentially the fitness, of ectothermic animals. We examined the effect of incubation temperature on the thermal preferences of juveniles in the oviparous lizard, Anolis carolinensis. Temperature preference trials were conducted in a laboratory thermal gradient within 48 hr of hatching and after 22–27 days of maintenance in a common laboratory environment. Incubation temperature had a significant effect on the upper limit of the interquartile range (IQR) of temperatures selected by A. carolinensis within the first 2 days after hatching. Between the first and second trials, the IQR of selected temperatures decreased significantly and both the lower limit of the IQR and the median selected temperature increased significantly. This, along with a significant incubation temperature by time interaction in the upper limit of the IQR, resulted in a pattern of convergence in thermoregulation among treatment groups. The initial differences in selected temperatures, as well as the shift in selected temperatures between first and second trials, demonstrate plasticity in temperature selection. As a previous study failed to find environmentally induced plasticity in temperature selection in adult A. carolinensis, this study suggests that this type of plasticity is exclusive to the period of neonatal development. J. Exp. Zool. 307A:439–448, 2007. © 2007 Wiley‐Liss, Inc.
Developmental and genetic mechanisms for evolutionary diversification of serial repeats: eyespot size in Bicyclus anynana butterflies
Authors: Beldade Patrícia , French Vernon , Brakefield Paul Martin
Published: June 2007

Serially repeated pattern elements on butterfly wings offer the opportunity for integrating genetic, developmental, and functional aspects towards understanding morphological diversification and the evolution of individuality. We use captive populations of Bicyclus anynana butterflies, an emerging model in evolutionary developmental biology, to explore the genetic and developmental basis of compartmentalized changes in eyespot patterns. There is much variation for different aspects of eyespot morphology, and knowledge about the genetic pathways and developmental processes involved in eyespot formation. Also, despite the strong correlations across all eyespots in one butterfly, B. anynana shows great potential for independent changes in the size of individual eyespots. It is, however, unclear to what extent the genetic and developmental processes underlying eyespot formation change in a localized manner to enable such individualization. We use micromanipulations of developing wings to dissect the contribution of different components of eyespot development to quantitative differences in eyespot size on one wing surface. Reciprocal transplants of presumptive eyespot foci between artificial selection lines and controls suggest that while localized antagonistic changes in eyespot size rely mostly on localized changes in focal signal strength, concerted changes depend greatly on epidermal response sensitivities. This potentially reflects differences between the signal‐response components of eyespot formation in the degrees of compartmentalization and/or the temporal pattern of selection. We also report on the phenotypic analysis of a number of mutant stocks demonstrating how single alleles can affect different eyespots in concert or independently, and thus contribute to the individualization of serially repeated traits. J. Exp. Zool. (Mol. Dev. Evol.) 310B:191–201, 2008. © 2007 Wiley‐Liss, Inc.
Mesoderm in spiralians: the organizer and the 4d cell
Authors: Lambert J. David
Published: June 2007

The Spiralia is a clade of protostome invertebrate phyla that share a highly conserved mode of early development. Spiralian development is characterized by regularities in the arrangement of early cleavages, the fates of the cells that are produced by these divisions, and the development of the distinctive trochophore larva. Because of the strong conservation in early development, homologies can be identified between cells in divergent taxa. Some of the most striking examples of conservation in the spiralian embryo are in the cells that generate the mesoderm. The specification of the mesodermal precursors has been well characterized by embryological approaches, and recently the molecular mechanisms of mesoderm specification are starting to be elucidated. This review examines the development of mesoderm in spiralians in a comparative context, with particular focus on the relationship between the mesendodermal cell 4d and the embryonic organizer. J. Exp. Zool. (Mol. Dev. Evol.) 310B:15–23, 2008. © 2007 Wiley‐Liss, Inc.
Use of a grid‐based hydrological model and regional climate model outputs to assess changing flood risk
Authors: Bell V. A. , Kay A. L. , Jones R. G. , Moore R. J.
Published: June 2007

A grid‐based flow routing and runoff‐production model, configured to employ regional climate model (RCM) precipitation estimates as input, is used to assess the effects of climate change on river flows in catchments across the UK. This model, the Grid‐to‐Grid model or G2G, has previously been calibrated and assessed with respect to observed river flows under current climate conditions. Here, the G2G distributed model together with a lumped catchment model, the parameter‐generalized PDM, are applied to simulate river flow and derive flood frequency curves. Two sets of RCM precipitation time‐series, on a 25‐km grid and at hourly intervals, are used: (1) Current (1961–1990) and (2) Future (2071–2100). The effect of one extreme rainfall event in the current precipitation series is to raise the estimated peak flows for some catchments for high return periods under present day rainfall conditions. The future flow series does not contain a comparable flow peak. This significantly affects comparison of the flood frequency curves derived from the flow simulations obtained using the current and future precipitation estimates. Such variability in the results and the dependence on one or two extreme rainfall events emphasizes the need to examine more than one set of current/future precipitation scenarios for flood impact studies. In the absence of a formal ensemble of climate predictions, a resampling method is used to investigate the robustness of the modelled changes in flood frequency. Changes in flood frequency at higher return periods are, not surprisingly, found to be generally less robust than at lower return periods. This is particularly the case for catchments in the south and east of England, which were especially affected by the extreme rainfall event in the current precipitation series. Copyright © 2007 Royal Meteorological Society
Contact areas of the tibiotalar joint
Authors: Windisch Gunther , Odehnal Boris , Reimann Reinhold , Anderhuber Friedrich , Stachel Hellmuth
Published: June 2007

The contact areas between the articular surfaces of the talus and tibia are essential for understanding the mobility of the ankle joint. The purpose of our study was to reveal the contact area among the superior articular surface of the trochlea tali (target surface T) and the inferior articular surface of the tibia (query surface Q) under non–weight‐bearing conditions in plantar flexion and dorsiflexion. Twenty cadaveric foot specimens were dissected and scanned by a three‐dimensional (3D) laser scanner to obtain data point sets. These point sets were triangulated and a registration procedure performed to avoid any intersection of the two joint surfaces. For all points of the query surface Q, the closest distance to T was measured. In 11 of the 20 ankle joints, the contact area was larger in plantar flexion, in 5 it was nearly of equal size, and in 4 the two surfaces were found in a better congruence in dorsiflexion. The two articular surfaces can be in point or line contact and cause different motions while T is gliding on Q, so the original geometry of ligaments must be carefully reconstructed after injury or during total ankle replacement. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1481–1487, 2007
Repair of porcine articular cartilage defect with a biphasic osteochondral composite
Authors: Jiang Ching‐Chuan , Chiang Hongsen , Liao Chun‐Jen , Lin Yu‐Ju , Kuo Tzong‐Fu , Shieh Chang‐Shun , Huang Yi‐You , Tuan Rocky S.
Published: June 2007

Autologous chondrocyte implantation (ACI) has been recently used to treat cartilage defects. Partly because of the success of mosaicplasty, a procedure that involves the implantation of native osteochondral plugs, it is of potential significance to consider the application of ACI in the form of biphasic osteochondral composites. To test the clinical applicability of such composite construct, we repaired osteochondral defect with ACI at low cell‐seeding density on a biphasic scaffold, and combined graft harvest and implantation in a single surgery. We fabricated a biphasic cylindrical porous plug of DL‐poly‐lactide‐co‐glycolide, with its lower body impregnated with β‐tricalcium phosphate as the osseous phase. Osteochondral defects were surgically created at the weight‐bearing surface of femoral condyles of Lee‐Sung mini‐pigs. Autologous chondrocytes isolated from the cartilage were seeded into the upper, chondral phase of the plug, which was inserted by press‐fitting to fill the defect. Defects treated with cell‐free plugs served as control. Outcome of repair was examined 6 months after surgery. In the osseous phase, the biomaterial retained in the center and cancellous bone formed in the periphery, integrating well with native subchondral bone with extensive remodeling, as depicted on X‐ray roentgenography by higher radiolucency. In the chondral phase, collagen type II immunohistochemistry and Safranin O histological staining showed hyaline cartilage regeneration in the experimental group, whereas only fibrous tissue formed in the control group. On the International Cartilage Repair Society Scale, the experimental group had higher mean scores in surface, matrix, cell distribution, and cell viability than control, but was comparable with the control group in subchondral bone and mineralization. Tensile stress–relaxation behavior determined by uni‐axial indentation test revealed similar creep property between the surface of the experimental specimen and native cartilage, but not the control specimen. Implanted autologous chondrocytes could survive and could yield hyaline‐like cartilage in vivo in the biphasic biomaterial construct. Pre‐seeding of osteogenic cells did not appear to be necessary to regenerate subchondral bone. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1277–1290, 2007
A kinetic study of the reactions of (+)‐catechin with aldehydes derived from toasted oak
Authors: Nonier Marie‐Françoise , Vivas Nicolas , Vivas de Gaulejac Nathalie , Pianet Isabelle , Fouquet Eric
Published: June 2007

The reactions between (+)‐catechin and representative oak wood furanic (furfuraldehyde, 5‐hydroxymethylfurfuraldehyde and 5‐methylfurfuraldehyde) and phenolic (vanillin and syringaldehyde) aldehydes in a wine‐like model solution were studied and the corresponding condensation kinetics at pH 3.0 and 3.5 were compared. A comparative study on the reactivity of these two representative families of aldehydes towards (+)‐catechin showed a large difference between them. When incubated separately with (+)‐catechin at both pH values, the reactions were faster with furanic aldehydes than with phenolic aldehydes. In mixtures containing (+)‐catechin and individual aldehydes, new compounds were identified by high‐performance liquid chromatography (HPLC)/UV–visible detection, some of which were characterised by liquid chromatography/electrospray ionisation mass spectrometry (LC/ESI‐MS). The increase in solution absorbance with time was closely linked to these new products. Copyright © 2007 Society of Chemical Industry
Local recurrence and local control of non‐metastatic osteosarcoma of the extremities: A 27‐year experience in a single institution
Authors: Bacci Gaetano , Forni Cristiana , Longhi Alessandra , Ferrari Stefano , Mercuri Mario , Bertoni Franco , Serra Massimo , Briccoli Antonio , Balladelli Alba , Picci Piero
Published: June 2007

Background

Indications and contraindications for limb salvage versus amputation for local treatment of osteosarcoma of the extremity are still controversial.

Patients and Methods

Patients (1,126) with non‐metastatic osteosarcoma of the extremity, treated in a single institution between 1972 and 1999 with different protocols of adjuvant and neoadjuvant chemotherapy were evaluated to establish factors that could influence local recurrence (LR) and outcome.

Results

The 5‐year event‐free survival and overall survival were 55% and 66%. At a follow‐up ranging between 5.5 and 32.5 years (mean18.6 years) of the 1,126 evaluated patients, 607 (54%) remained continuously disease‐free and 519 relapsed. LR developed in 61 patients (5.4%) after a median time of 2.3 years (0.2–17). For this group of patients the 5‐year post‐relapse event‐free survival and overall survival from the last relapse were, respectively, 11.4% and 16.4%. At the multivariate analyses only surgical margins and histologic response to preoperative treatment resulted to be independent prognostic factors for LR.

Conclusion

Considering the risk of LR after surgery with inadequate surgical margins and poor prognosis of LR in osteosarcoma, limb salvage procedures should be performed only when adequate margins surgical margins can be achieved. In case of inadequate margins, an immediate amputation should be considered. J. Surg. Oncol. 2007;96:118–123. © 2007 Wiley‐Liss, Inc.
Eigenvalue distribution of Mercer‐like kernels
Authors: Buescu Jorge , Paixão A. C.
Published: June 2007

We study eigenvalues of positive definite kernels of L2 integral operators on arbitrary intervals. Assuming integrability and uniform continuity of the kernel on the diagonal, we show that the eigenvalue distribution is totally determined by the smoothness of the kernel together with its decay rate at infinity along the diagonal. Moreover, the rate of decay of eigenvalues depends on both these quantities in a symmetrical way. Our main result treats all possible orders of differentiability and all possible rates of decay of the kernel; the known optimal results for eigenvalue distribution of positive definite kernels in compact intervals are particular cases. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
About explicit factorization of some classes of non‐rational matrix functions
Authors: Conceição Ana C. , Kravchenko Viktor G.
Published: June 2007

We construct an algorithm that allows us to determine an effective canonical factorization of some non‐rational matrix‐valued functions. For those matrix‐valued functions whose entries can be represented through a innerouter factorization (when the outer function is rational) it is shown that its explicit factorization can be obtained through the solutions of two non‐homogeneous equations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stokes resolvent systems in an infinite cylinder
Authors: Farwig Reinhard , Ri Myong‐Hwan
Published: June 2007

In an infinite cylinder Ω = Σ × ℝ, where Σ ⊂ ℝn –1, n ≥ 3, is a bounded domain of C1,1 class, we study the unique solvability of Stokes resolvent systems in Lq (ℝ; L2(Σ)) for 1 < q < ∞ and in vector‐valued homogeneous Besov spaces (ℝ; Lr (Σ)) for 1 ≤ p, q ≤ ∞, s ∈ ℝ, 1 < r < ∞. By a partial Fourier transform along the axis of the cylinder Ω the given system is reduced to a parametrized system on Σ, for which parameter independent estimates are proved. For further applications we obtain even parameter independent estimates in Lr (Σ), 1 < r < ∞, in the non‐solenoidal case prescribing an arbitrary divergence g = div u. Then operator‐valued multiplier theorems are used for the final estimates of the Stokes resolvent systems in Ω. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Applications of operator equalities to singular integral operators and to Riemann boundary value problems
Authors: Karelin Aleksandr
Published: June 2007

In the first part of this article (Section 2), we consider a Riemann boundary value problem with shift and piecewise constant coefficients. In the second part (Section 3), we consider a matrix characteristic singular integral operators with piecewise constant coefficients of a special structure. Simplicity of the shift and the coefficients under consideration permits us to obtain conditions under which the Riemann boundary value problem admits an unique solution and to study the invertibility of the matrix characteristic singular integral operators. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asymptotics of block Toeplitz determinants generated by factorable matrix functions with equal partial indices
Authors: Karlovich Alexei Yu.
Published: June 2007

We prove asymptotic formulas for block Toeplitz matrices with symbols admitting right and left Wiener–Hopf factorizations such that all partial indices are equal to some integer number. We consider symbols and Wiener–Hopf factorizations in Wiener algebras with weights satisfying natural submultiplicativity, monotonicity, and regularity conditions. Our results complement known formulas for Hölder continuous symbols due to Böttcher and Silbermann. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pseudodifferential operators with compound non‐regular symbols
Authors: Karlovich Yu. I.
Published: June 2007

Let V (ℝ) denote the Banach algebra of absolutely continuous functions of bounded total variation on ℝ. We study an algebra 𝔅 of pseudodifferential operators of zero order with compound slowly oscillating V (ℝ)‐valued symbols (x, y) ↦ a (x, y, ·) that satisfy a Lipschitz condition with respect to the spatial variables x, y ∈ ℝ. Sufficient conditions for the boundedness and compactness of pseudodifferential operators with compound symbols on the Lebesgue spaces Lp (ℝ), for p = 2 and 1 < p < ∞, are obtained. A Fredholm criterion and an index formula for pseudodifferential operators A ∈ 𝔅 are presented. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Factorization of singular integral operators with a Carleman shift via factorization of matrix functions: the anticommutative case
Authors: Kravchenko V. G. , Lebre A. B. , Rodríguez J. S.
Published: June 2007

This paper deals with what we call modified singular integral operators. When dealing with (pure) singular integral operators on the unit circle with coefficients belonging to a decomposing algebra of continuous functions it is known that a factorization of the symbol induces a factorization of the original operator, which is a representation of the operator as a product of three singular integral operators where the outer operators in that representation are invertible.

The main purpose of this paper is to obtain a similar operator factorization for the case of singular integral operators with a backward shift and to extract from there some consequences for their Fredholm characteristics. At the end of the paper it is shown that the operator factorization is also possible for other classes of singular integral operators, namely those including either a conjugation operator or a composition of a conjugation with a forward shift operator. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On some characterizations of Besov spaces of generalized smoothness
Authors: Moura Susana D.
Published: June 2007

We present characterizations of the Besov spaces of generalized smoothness$ B^{\sigma,N}_{p,q} $(ℝn) via approximation and by means of differences. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A one‐parameter calculus for symmetric domains
Authors: Arazy Jonathan , Upmeier Harald
Published: June 2007

We introduce a parameter dependent operator calculus on hermitian symmetric domains, interpolating the Toeplitz and Weyl calculus, and establish its basic properties including the Berezin transform for rank 1 domains. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulated annealing applied to the optimal plastic design of circular steel plates
Authors: Laplume D. , Lamblin D.
Published: June 2007

This article describes an application of the simulated annealing (SA) algorithm to a structural problem, consisting in finding a minimum‐weight circular plate of the imposed limit load.

For technological reasons, the considered plates are divided into rings of constant thickness. The boundaries of these rings may vary, so the thickness and size of each ring are the design variables to be considered. Although SA is mostly applied to handle combinatorial optimization problems, the present study shows that it can also be efficient in the field of mechanical engineering.

Some particular aspects of the study are thoroughly described. For instance, technological constraints have to be considered: lower and upper bounds are imposed on the thickness of each ring, and a lower bound is imposed on the ring width. These constraints are not taken into account by means of a classical penalty method, but by a set of dedicated
procedures.

The particular constraint of the imposed limit load is treated by solving the inverse problem at each iteration: the limit load of the current solution is computed and the geometry of the plate is adapted to fit the assigned value.

After discussion about points of attention, general conclusions are drawn from the performances of SA in its present implementation. The obtained results show that the algorithm exhibits satisfactory levels of reliability and efficiency. Copyright © 2007 John Wiley & Sons, Ltd.
Coupled lattice Boltzmann method and discrete element modelling of particle transport in turbulent fluid flows: Computational issues
Authors: Feng Y. T. , Han K. , Owen D. R. J.
Published: June 2007

This paper presents essential numerical procedures in the context of the coupled lattice Boltzmann (LB) and discrete element (DE) solution strategy for the simulation of particle transport in turbulent fluid flows. Key computational issues involved are (1) the standard LB formulation for the solution of incompressible fluid flows, (2) the incorporation of large eddy simulation (LES)‐based turbulence models in the LB equations for turbulent flows, (3) the computation of hydrodynamic interaction forces of the fluid and moving particles; and (4) the DE modelling of the interaction between solid particles. A complete list is provided for the conversion of relevant physical variables to lattice units to facilitate the understanding and implementation of the coupled methodology. Additional contributions made in this work include the
application of the Smagorinsky turbulence model to moving particles and the proposal of a subcycling time integration scheme for the DE modelling to ensure an overall stable solution. A particle transport problem comprising 70 large particles and high Reynolds number (around 56 000) is provided to demonstrate the capability of the presented coupling strategy. Copyright © 2007 John Wiley & Sons, Ltd.
Zur Geschichte der Therapie der Epilepsie. Eine der ältesten bekannten Krankheiten
Authors: Tajerbashi Bardia , Friedrich Christoph
Published: June 2007

Die Epilepsie gehört zu den ältesten Krankheiten und ist für nahezu alle alten Kulturen belegt. In der Therapie spielten lange Zeit magisch‐mystische Methoden eine bevorzugte Rolle. Erst im Corpus Hippocraticum verlor sie allmählich den Mythos einer “heiligen Krankheit”, und als Ursprungsort galt von nun an das Gehirn. Im Mittelalter nahm jedoch der Exorzismus neben Mitteln aus der Dreckapotheke noch eine bevorzugte Stellung ein. In der Frühen Neuzeit verwendete man pflanzliche Drogen und seit dem 18. Jahrhundert bevorzugt Radix Valerianae. Seit der Mitte des 19. Jahrhunderts fanden chemische Stoffe Eingang in die Therapie, zunächst Bromide und ab 1912 Phenobarbital (Luminal®). 1931 folgte das N‐Methyl‐Luminal und 1943 Phenytoin. Seit Mitte des 20. Jahrhunderts werden Oxazolidin‐Derivate vornehmlich bei Petit‐Mal‐Attacken eingesetzt. Besondere Bedeutung erlangte das 1954 eingeführte Primidon. Als noch wirksamer erwiesen sich die 1951 synthetisierten Phenylsuccinimide. Die bereits 1881 synthetisierte Valproinsäure fand aufgrund des Nachweises antikonvulsiver Eigenschaften 1963 durch H. Meunier als Antiepileptikum Verwendung. Auf der Suche nach neuen Neuroleptika synthetisierten Walter Schindler (1912–1971) und Hans Blattner (geb. 1921), ausgehend vom Chlorpromazin, 1957 Carbamazepin, das fünf Jahre später als Antiepileptikum in die Therapie eingeführt wurde. Schließlich finden auch die 1961 von Leo Henryk Sternbach (1908–2005) entwickelten Benzodiazepine, besonders das 1963 eingeführte Diazepam, in der Akutbehandlung von Epileptikern Anwendung.
Die Kosten der Epilepsie in Deutschland. Gesundheitsökonomische Evaluation einer chronischen Krankheit
Authors: Dodel Richard , Rosenow Felix , Hamer Hajo Martinus
Published: June 2007

Obgleich Epilepsien eine der häufigsten chronisch neurologischen Erkrankungen darstellen und deswegen einen hohen Resourcenverbrauch im Gesundheitswesen erwarten lassen, stehen für das deutsche Gesundheitswesen, wie für viele andere neurologische Erkrankungen, nur wenige gesundheitsökonomische Evaluationen zur Verfügung. Jährlichen Gesamtkosten der Therapie sind anhand der vorhandenen Datenlage auf ca. R 10.000 zu schätzen, wobei indirekte Kosten überwiegen. Frühberentung gefolgt von Medikamentenkosten spielen die größte Rolle. Allerdings sind die Kosten für die Behandlung eines Epilepsie‐Patienten um ein Vielfaches geringer als diejenigen, die für andere chronische nervenärztliche Krankheiten, wie M. Parkinson (ca. R 20.000/a) oder M. Alzheimer (ca. R 35.000/a) anfallen. Für eine rationale Entscheidung zur Resourcenallokation sind detaillierte gesundheitsökonomische Evaluationen der eingesetzten alten und (in der Regel besser verträglichen) neueren Medikamente und der nicht‐medikamentösen Therapieformen dringend notwendig.
Neue Antiepileptika in der Entwicklung. Substanzen mit neuen Wirkmechanismen
Authors: Dannhardt Gerd , Kiefer Werner
Published: June 2007

Unbestritten ist, dass sich durch den Einsatz von Antiepileptika der 2. Generation die Situation für Epilepsiepatienten entscheidend verbessert hat. Dennoch bleibt ein Patientenklientel, bei dem keine ausreichende Anfallskontrolle erreicht wird, das therapierefraktär ist oder im Verlauf der Behandlung wird. Weiterentwicklungen von AEDs aus der 2. Generation (“follow‐up compounds”) bzw. Wirkstoffe mit neuen Strukturen und Wirkmechanismen könnten zukünftig diese Lücke füllen.
Klinische Studie mit Inhibitor der HIV‐Integrase
Authors: Winckler Thomas
Published: June 2007

“Raltegravir ist [...] momentan die wohl spannendste neue Substanz in der HIV‐Therapie überhaupt.”
No Entry
Authors: Schuwald Anita , Taupitz Thomas , Köper Katharina , Herdling Mirco , Dingermann Theo , Zündorf Ilse
Published: June 2007

Am 26. April 2007 hat das Antiviral Drugs Advisory Commitee der FDA einstimmig die Empfehlung ausgesprochen, Maraviroc (Celsentri™) für die Therapie von vorbehandelten HIV‐Patienten mit CCR5‐tropen Viren zuzulassen. Die endgültige Entscheidung über die Zulassung wird in den USA im Juli erwartet, in Europa einige Monate später.
Protein kinase C inhibition in diabetic retinopathy and microvascular disease
Authors: Walton C , Ryder REJ , Girach A
Published: June 2007

Protein kinase C (PKC) activation by hyperglycaemia may play an important role in the evolution of diabetic retinopathy and other microvascular complications. The PKC‐β inhibitor ruboxistaurin belongs to a new class of drugs and has been studied in several clinical trials in microvascular disease, the outcomes of which are described in this review. Ruboxistaurin exhibits promise as the first oral treatment shown to reduce visual loss and the need for laser treatment for macular oedema in patients with moderate to severe non‐proliferative diabetic retinopathy. Copyright © 2007 John Wiley & Sons.
Hypogonadism in men with type 2 diabetes
Authors: Jones TH
Published: June 2007

Recent studies demonstrate a high prevalence of hypogonadism in men with metabolic syndrome and type 2 diabetes. Men with low testosterone levels have a higher mortality rate. Diagnosis and treatment with testosterone replacement can lead to improvement in well‐being and quality of life. Early studies of testosterone replacement therapy have shown a benefit on glycaemic control, insulin resistance, visceral adiposity and cholesterol. Low testosterone levels are associated with the presence and the degree of atherosclerosis in carotid, coronary and aortic vessels. Furthermore, testosterone replacement therapy in testosterone deficient men with erectile dysfunction converts over half of PDE5 inhibitor non‐responders to responders. This review presents the up‐to‐date evidence in relation to testosterone, and discusses the importance of criteria to make a diagnosis of hypogonadism in diabetic men. Copyright © 2007 John Wiley & Sons.
Synthesis and characterization of novel polystyrene‐block‐polyurethane‐block‐polystyrene tri‐block copolymers through atom transfer radical polymerization
Authors: Verma Hemant , Tharanikkarasu Kannan
Published: June 2007

Background: Radical polymerization is used widely to polymerize more than 70% of vinyl monomers in industry, but the control over molecular weight and end group of the resulting polymers is always a challenging task with this method. To prepare polymers with desired molecular weight and end groups, many controlled radical polymerization (CRP) ideas have been proposed over the last decade. Atom transfer radical polymerization (ATRP) is one of the successful CRP techniques. Using ATRP, there is no report on the synthesis of polystyrene‐block‐polyurethane‐block‐polystyrene (PSt‐b‐PU‐b‐PSt) tri‐block copolymers. Hence this paper describes the method of synthesizing these tri‐block copolymers. To accomplish this, first telechelic bromo‐terminated polyurethane was synthesized and used further to synthesize PSt‐b‐PU‐b‐PSt tri‐block copolymers using CuBr as a catalyst and N,N,N,N″,N″‐pentamethyldiethylenetriamine as a complexing agent. Results: The ‘living’ nature of the initiating system was confirmed by linear increase of number‐average molecular weight and conversion with time. A semi‐logarithmic kinetics plot shows that the concentration of propagating radical is steady. The results from nuclear magnetic resonance spectroscopy, gel permeation chromatography and differential scanning calorimetry show that the novel PSt‐b‐PU‐b‐PSt tri‐block copolymers were formed through the ATRP mechanism. Conclusion: For the first time, PSt‐b‐PU‐b‐PSt tri‐block copolymers were synthesized through ATRP. The advantage of this method is that the controlled incorporation of polystyrene block in polyurethane can be achieved by simply changing the polymerization time. Copyright © 2007 Society of Chemical Industry
Acceptability of common screening methods used to detect distress and related mood disorders—preferences of cancer specialists and non‐specialists
Authors: Mitchell Alex J. , Kaar Stephen , Coggan Chris , Herdman Joanne
Published: June 2007

A new questionnaire of clinicians' attitudes and practices in relation to screening for mood disorder was distributed to 300 cancer professionals (specialists and non‐specialists) working across the UK. From 226 (75.3%) health professionals working in cancer care who responded, approximately two‐thirds always or regularly attempted to detect mood disorder during consultations but a substantial minority relied on patients spontaneously mentioning an emotional issue. The highest rate of routine questioning was performed by clinicians working in palliative medicine (76.3%) as well as nurse specialists working in all areas (72%). Despite these relatively high rates of enquiry, 10% or less of all specialists used a validated questionnaire, most preferring to rely on their own clinical skills or recalling the two simple questions of the short Patient Health Questionnaire (PHQ2). Staff suggested that ideal screening practice was to use one, two or three simple questions or a short validated questionnaire but not to refer to a specialist for a diagnosis. The main barrier to successful screening was lack of time but insufficient training and low confidence were also influential. Once distress was detected, 90% of nurses but only 40% of doctors were prepared to give distressed patients as much time as they needed. Predictors of clinicians' willingness to use more advanced screening methods were length of follow‐up appointments and time clinicians were prepared to spend detecting distress. We suggest that future field studies of screening tools should also measure the issue of acceptability. Copyright © 2007 John Wiley & Sons, Ltd.
Impact of maternal breast cancer on the peer interactions of children at school
Authors: Vannatta Kathryn , Grollman Jamie A. , Noll Robert B. , Gerhardt Cynthia A.
Published: June 2007

Relatively little research has investigated the impact of parental cancer on developmental outcomes for school‐aged children beyond the home. The current study was designed to examine the impact of maternal breast cancer on the social behavior, peer acceptance, and friendships of children and adolescents at school. It was hypothesized that children of women with breast cancer would have fewer friends and be viewed by peers, teachers, and themselves as more socially isolated than comparison classmates. A sample of 60 school‐aged children (age 8–16) of women with breast cancer, 58 teachers, and 1138 classmates provided data in classroom settings. Comparisons were made between children in the maternal cancer sample and 60 classmates matched for gender, race, and age. No overall group differences were found on indicators of peer acceptance or friendships at school. Although marked behavioral similarities were found between groups, analyses indicated that sons, but not daughters, of mothers with breast cancer were seen by teachers and peers as more socially sensitive and isolated than comparison peers. Further research is warranted to confirm findings that sons of mothers with breast cancer may experience social isolation and to examine the stability and consequences of this behavioral pattern. Copyright © 2007 John Wiley & Sons, Ltd.