bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional deficits resulting from laser‐induced damage in the rat retina
Authors: Ben‐Shlomo Gil , Belokopytov Mark , Rosner Mordechai , Dubinsky Galina , Belkin Michael , Epstein Yoram , Ofri Ron 
Published: July 2006

AbstractBackground and ObjectivesTo determine the threshold for electrophysiological detection of functional changes after laser photocoagulation in rats, and to correlate the functional damage with retinal morphology.Study Design/Materials and MethodsArgon‐laser lesions, covering a quarter or half of the retina, were produced in the right eyes of 25 rats. Eyes were evaluated by flash electroretinography (ERG) and histologically at 3, 21, and 60 days after lasering.ResultsLasering of half the retina, but not of a quarter, produced a significant decrease in signals at all time points. Some functional recovery was evident 60 days after injury, and was consistent with concurrent morphological healing.ConclusionsIn rats, lasering of half the retina, but not a quarter, leads to significant deficits in outer retinal functions over a 2‐month period. Thereafter some recovery occurs, presumably as a result of migration of photoreceptors from undamaged areas and their retinal remodeling. © 2006 Wiley‐Liss, Inc.
A rain water infiltration model with unilateral boundary condition: qualitative analysis and numerical simulations
Authors: Borsi I. , Farina A. , Primicerio M. 
Published: July 2006

AbstractWe present a rigorous mathematical treatment of a model describing rain water infiltration through the vadose zone in case of runoff of the excess water. The main feature of the mathematical problem emerging from the model lies on the boundary condition on the ground surface which is in the form of a unilateral constraint. Existence and uniqueness of a weak solution is proved under general assumptions. We present also the results of a numerical study comparing the proposed model with other models which approach in a different way the rain water infiltration problem. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis of the mRNA expression of the TGF‐Beta family in testicular cells and localization of the splice variant TGF‐β2B in testis
Authors: Konrad Lutz , Lüers Georg H. , Völck‐Badouin Elke , Keilani Marcel M. , Laible Leslie , Aumüller Gerhard , Hofmann Rainer 
Published: July 2006

AbstractThe transforming growth factors (TGF)‐β, TGF‐β1, TGF‐β2, and TGF‐β3, and their receptors [TβRI, TβRII, TβRIII (betaglycan)] elicit many functions in the testis, for example, they perturb the blood testis barrier (BTB). Although expression of the ligands and receptors have been investigated, the alternative splice variants are incompletely examined. We therefore have analyzed all ligands, the receptors, and the splice variants TβRIB, TβRIIB, and TGF‐β2B in testicular cells from rat and mouse. In mouse, the novel transcript variant TGF‐β2B was identified and was found in Leydig cells, spermatogonia, pachytene spermatocytes, and in the apical regions of the Sertoli cells in adult testis. Even though expression of the splice variant TβRIB could be shown in mouse and rat, we never found the isoform TβRIIB in the rat cell lines studied. Whereas in all testicular cells expression of all TGF‐β ligands could be shown, receptor mRNA expression was slightly more diverse. Furthermore, expression pattern of the splice variants was more heterogeneous, for example, TβRIB was not detectable in adult Sertoli cells, primary peritubular cells, and immortalized peritubular cells. The heterogeneous expression of the receptors and especially of the splice variants might provide possible clues for the different functions of the TGF‐β ligands in testicular cells. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Proliferative characteristics and chromosomal stability of bovine donor cells for nuclear transfer
Authors: Giraldo Angelica M. , Lynn John W. , Godke Robert A. , Bondioli Kenneth R. 
Published: July 2006

AbstractFew studies have characterized donor cell lines in terms of proliferative capacity and chromosomal stability. Abnormal phosphorylation patterns of the histones during metaphase could lead to abnormal chromosome segregation and extensive chromosome loss during mitosis. Suboptimal culture conditions may lead to abnormal histone H3 phosphorylation patterns, ultimately inducing missegregation and loss of chromosomes. The objective of the present study was to determine proliferative characteristics, chromosomal stability, and level of histone phosphorylation in cell lines established by explants and enzymatic dissociation. Proliferative characteristics, percentage of aneuploid cells, and relative levels of phosphorylated histone H3 (ser10) were determined at different population doublings (PD) by cell counting, karyotyping, and flow cytometry, respectively. The level of aneuploidies was high and remained elevated throughout the study independent of the technique used to establish the primary culture. Some cell lines had up to 50% of aneuploid cells during early passages. Multinucleated cells and abnormal spindle configurations were observed after prolonged time in culture (60 and 41%, respectively). An increase in the relative level of phosphorylated histone occurred after extended time in culture (55.7 during early passages vs. 102.6 at late passages). These data demonstrate the importance of determining chromosome content and the selection of healthy cell lines to decrease the percentage of aneuploid reconstructed embryos and increase the efficiency of nuclear transfer (NT). Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
New insights towards understanding the mechanisms of sperm protection by egg yolk and milk
Authors: Bergeron Annick , Manjunath Puttaswamy 
Published: July 2006

AbstractMammalian sperm preservation in extenders containing egg yolk (EY) and/or milk has been used for over half a century. However, the mechanism by which EY or milk protects sperm during storage remains elusive. Studies conducted over the past two decades in our laboratory have revealed that a family of lipid‐binding proteins (BSP proteins) present in bull seminal plasma is detrimental to sperm preservation since these proteins induce cholesterol and phospholipid removal from the sperm membrane. Interestingly, these detrimental factors of seminal plasma interact with the low‐density lipoproteins (LDL) present in EY. This interaction minimizes lipid removal from the sperm membrane, which positively influences sperm storage in liquid or frozen states. Based on several lines of evidence, we suggest that the sequestration of BSP proteins by LDL (BSP proteins: lipoprotein interaction) is the major mechanism of sperm protection by EY. Skimmed milk, which is devoid of lipoproteins, also protects sperm during storage. Several studies indicate that the active components involved in sperm protection by milk are casein micelles. Thus, it appears that the mechanism by which milk protects sperm involves a BSP protein: casein micelle interaction. In view of these new insights, novel strategies have been suggested to improve the efficiency of semen preservation. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Water diffusion heterogeneity index in the human brain is insensitive to the orientation of applied magnetic field gradients
Authors: Bennett Kevin M. , Hyde James S. , Schmainda Kathleen M. 
Published: July 2006

AbstractThe α diffusion‐weighted imaging (DWI) method was developed to study heterogeneous water diffusion in the human brain using magnetic resonance imaging (MRI). An advantage of this model is that it does not require an assumption about the shape of the intravoxel distribution of apparent diffusion rates, and it has a calculable relationship to this distribution. The α‐DWI technique is useful for detecting microstructural tissue changes associated with brain tumor invasion, and may be useful for directing therapy to invading tumor cells. In previous work, α‐DWI was performed with magnetic field gradients applied along a single direction in order to avoid artificially introducing a source of heterogeneity to the decay. However, it is known that restricted diffusion is anisotropic in the brain, and the α‐DWI method must take this into account to be complete. In this work the relationship between the applied magnetic field gradients and the fitted stretched‐exponential model parameters was studied in the human brain. It was found the distributed diffusion coefficient (DDC) varies with the direction of applied gradients, while the heterogeneity index α is relatively direction‐insensitive. It is proposed that in clinical use, maps of α can be created using diffusion‐weighting gradients applied in a single direction that reflect the tissue heterogeneity. Magn Reson Med, 2006. Published 2006 Wiley‐Liss, Inc.
Comparing services: a survey of leading issues in the sectoral literatures
Authors: Moran Dominique 
Published: July 2006

AbstractThis article locates the following sector articles in a review of recent research into government interventions in the non‐state provision (NSP) of education, health, water and sanitation. Non‐state providers (NSPs) are defined here to include all those existing outside the public sector, whether they operate for profit or for philanthropic purposes. Operators may be communities, NGOs, faith‐based organisations (FBOs), private companies, small‐scale informal providers or individual practitioners. The article prefaces this Symposium by discussing the extent of previous research and identifying gaps in the literature with regard to key issues regarding NSP. It deals with state intervention and the state/non‐state relationship in service provision, considering the main aspects of this relationship that are covered in the sector articles: policy dialogue and government capacity to regulate and facilitate, and to contract NSPs. Copyright © 2006 John Wiley & Sons, Ltd.
Collaborating in education for all? Experiences of government support for non‐state provision of basic education in South Asia and Sub‐Saharan Africa
Authors: Rose Pauline 
Published: July 2006

AbstractWhile basic education is commonly seen as primarily a state responsibility, non‐state providers (NSPs) can play an important role in expanding access to children underserved by public provision. Experience from five countries indicates that collaboration between governments and NSPs is closest when different forms of engagement interact (for example, facilitation or contracting of education services necessitating regulation which can lead to greater involvement in policy dialogue). However, more intense forms of engagement can result in tension, mistrust and even antagonism, particularly where dominant but ineffective centralised ministries of education attempt to maintain control over the sector, even where they are unable to support their own provision effectively. In such contexts, collusion between NSPs through umbrella associations is apparent, often with the aim of challenging restrictive government practices. However, evidence suggests that these associations tend to favour more established NSPs serving élite populations. There is a need both to recognise the complexities of collaboration amongst a diverse group of NSPs, as well as between them and governments, to support the achievement of education for all. Copyright © 2006 John Wiley & Sons, Ltd.
Determining the phase behavior of nanoparticle‐filled binary blends
Authors: He Gang , Ginzburg Valeriy V. , Balazs Anna C. 
Published: July 2006

AbstractNanoparticle additives provide a means of imparting the desired electrical, optical, or mechanical properties to a polymeric matrix. The difficulty faced in creating these composites is determining the optimal conditions for forming a thermodynamically stable mixture, where the particles will not phase separate from the matrix material. This challenge is even more daunting when the polymeric matrix is itself a multicomponent mixture, as is often the case in advanced materials. Ideally, the nanoparticles would not only contribute the needed physical properties, but also stabilize the mixture so that the entire system forms a single‐phase system. In this study, we use a free energy expression for a binary blend that contains nanoparticles and take the interaction parameters between the different species to be independent variables. Thus, the particles can have distinct enthalpic interactions with each of the polymeric components. Using this expression, we determine the conditions under which the mixture forms a stable, single‐phase material. In particular, we isolate how variations in the system's parameters (e.g., polymer composition, particle volume fraction, particle size, interaction energies) affect the phase diagrams. The findings provide guidelines for creating effective formulations and can allow researchers to understand how choices made in the nature of the components affect the overall macroscopic properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2389–2403, 2006
Conformation of comb‐like liquid crystal polymers in isotropic solution probed by small‐angle neutron scattering
Authors: Zhao Yiqiang , Jamieson Alex M. , Olson Brian G. , Yao Ning , Dong Shaosheng , Nazarenko Sergei , Hu Xuesong , Lal Jyotsana 
Published: July 2006

AbstractThe conformational characteristics of a comb‐like side‐chain liquid crystal polysiloxane (SCLCP), dissolved in deuterated chloroform, were evaluated by small‐angle neutron scattering (SANS) measurements over a wide q range. SANS studies were carried out on specimens with constant backbone length (DP = 198) and variable spacer length (n = 3, 5, and 11), and with constant spacer length (n = 5) and variable DP (45, 72, 127, and 198). The form factor P(q) at high q was analyzed using the wormlike chain model with finite cross‐sectional thickness (Rc) and taking into account the molecular weight polydispersity. The analysis generated values of persistence length in the range lp = 28–32 Å, considerably larger than that of the unsubstituted polysiloxane chain (lp = 5.8 Å), with contour lengths per monomer comparable to the fully‐extended polysiloxane backbone (lm = 2.9 Å). This indicates a relatively rigid SCLCP chain due to the influence of the densely attached mesogenic groups. The SCLCP with n = 11 is more flexible (lp = 28 Å) than those with n = 3 and n = 5 (lp = 32 Å). The cross‐sectional thickness increases with spacer length, Rc ∼ n0.21±0.02 (3 ≤ n ≤ 11), and the contour length per monomer decreases with increasing spacer length, lm ∼ n−0.35±0.01. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2412–2424, 2006
Interactions of water with OH groups in poly(ethylene‐co‐vinyl alcohol)
Authors: Iwamoto Reikichi , Matsuda Toshihiko , Amiya Shigetoshi , Yamamoto Tomoyuki 
Published: July 2006

AbstractWe studied interactions of water with OH groups in poly(ethylene‐co‐vinyl alcohol) (EVOH) of the ethylene (Et) compositions of 33, 49, 75, and 89% (mol) using near‐infrared spectroscopy. OH groups are mostly self‐associated and only partly isolated in EVOH matrix, and the fraction of the isolated OH increases with the increase in Et composition. Interactions of water in EVOH were analyzed on the basis of the difference spectrum between the spectrum in a hydrated state and that in the dehydrated state of a sample. The water contained in an EVOH sample with a higher Et content shows a more distinct sharp combination band at about 5285 cm−1 in addition to the main broad band at about 5150 cm−1. The former was assigned to the water that is one‐to‐one hydrogen‐bonded to an isolated OH in the manner as OH::OH2 from the effect of the hydration on the near‐infrared and infrared bands of the isolated OH. The latter was assigned to the water that is multiply hydrogen‐bonded to surrounding associated OH groups and that does not cluster. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2425–2437, 2006
Effects of Al2O3 nanometer particles addition on the fluctuation conductivity in (Bi,Pb)‐2223 superconductors
Authors: Ben Azzouz F. , Annabi M. , Zouaoui M. , Ben Salem M. 
Published: July 2006

AbstractNanometer Al2O3 particles were added to (Bi,Pb)2Sr2Ca2Cu3Ox (Bi,Pb)‐2223 precursor powders during the final sintering cycle of a multi‐step preparation process. The temperature dependence of the resistance in 0 and 0.2% Al2O3‐added (Bi,Pb)2Sr2Ca2Cu3Ox samples was measured. Data about the dimensionality of the fluctuation is obtained by analyzing the fluctuation conductivity Δσ as a function of ε = ln (T/TC) on the basis of the Aslamazov–Larkin theory. Within the mean field region, we first observe a regime dominated by 2D Gaussian fluctuation. With decreasing temperature a crossover occurs at a temperature TG and the obtained regime was described by critical fluctuations. The Ginzburg number and fluctuation amplitude, increase with addition of nanometer Al2O3 particles. Correlation between fluctuation amplitude and JC has been discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum fluctuation and tunneling of a superconducting nano‐grain
Authors: Afzali R. 
Published: July 2006

AbstractQuantum fluctuation and tunneling of a superconducting nano‐grain placed in magnetic field are analytically considered in frequency space. Tunneling fluctuation of a superconducting grain to superposition of superconducting and paramagnetic states are investigated. By using Fourier transformation, instanton equations are solved. Then, by supposing smallness of deviation of order parameter with respect to BCS energy gap, matrix Green function of system and self‐consistent equation of order parameter in frequency space, at first approximation, for both d ‐wave and s ‐wave case, is obtained. Based on analytic form of order parameter of system at Fermi sphere, quantum phase transition of a s‐wave superconducting grain is shown. For d‐wave case, investigating of tunneling process at first approximation is subtle and needs further attention. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of Ce substitution in RuGd2–xCexSr2Cu2O10–δ (Ru‐1222)
Authors: Hadipour H. , Sabri D. , Mirzadeh M. , Akhavan M. 
Published: July 2006

AbstractWe have studied the electrical and magnetic properties of RuGd2–xCexSr2Cu2O10–δ (Ru‐1222) with content of Ce = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, prepared by the standard solid‐state reaction technique. To determine how the magnetic and superconducting properties of this layered cuprate system can be affected by Ce substitution, the resistivity and magnetoresistivity have been measured at various temperatures. Resistivity curves reveal the presence of four regions for various contents of x. In high temperatures, system is paramagnetic. Magnetic transition from paramagnetic state to antiferromagnetic state occurs at 140 K for x = 0, which varies very slowly with increasing Ce substitution for Gd. In lower temperatures, second magnetic transition from antiferromagnetic to ferromagnetic is observed, which shifts from 60 K to 120 K with increasing x from 0.0 to 0.5. This variation may be caused by different ionic radii of Ce and Gd in this material which affects the Ru‐Ru interaction. Finally, the insulator‐superconductor transition take place at Tc, which shifts to higher temperature with appropriate variation of Gd/Ce. Superconductivity in the CuO2 planes and weak ferromagnetism in Ru sublattice coexist and two states are practically decoupled. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New world of Gossamer superconductivity
Authors: Maki Kazumi , Haas Stephan , Parker David , Won Hyekyung , Dora Balazs , Virosztek Attila 
Published: July 2006

AbstractSince the discovery of the high‐T c cuprate superconductor La2–x BaCuO4 in 1986 by Bednorz and Müller, controversy regarding the nature or origin of this remarkable superconductivity has continued. However, d‐wave superconductivity in the hole‐doped cuprates, arising due to the anti‐paramagnon exchange, was established around 1994. More recently we have shown that the mean field theory, like the BCS theory of superconductivity and Landau's Fermi liquid theory are adequate to describe the cuprates. The keys for this development are the facts that a) the pseudogap phase is d‐wave density wave (dDW) and that the high‐T c cuprate superconductivity is gossamer (i.e. it exists in the presence of dDW). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of Pr at R and Ba sites on the electronic structure of RBa2Cu3O7
Authors: Ghanbarian V. , Mohammadizadeh M. R. 
Published: July 2006

AbstractBased on the full potential linearized augmented plane wave method within LSDA and LSDA+U approximations the electronic band structures of YBa2Cu3O7 (Y123), PrBa2Cu3O7 (Pr123) and Pr(BaPr)Cu3O7 (PrBa) systems were calculated. Qualitative similarity between the band structures of Y123 and Pr123 systems shows that Pr123 must have similar electronic behaviors to Y123; both should be metal and become superconductor. The PrBa mis‐substitution reduces metallic (superconducting) character of perfect Pr123 samples and can be responsible for suppression of metallic and superconducting characters of Pr123 samples. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Superconductivity in an ultra‐small radius SWCNT
Authors: Mohammadizadeh M. R. 
Published: July 2006

AbstractElectronic and structural properties of an ultra‐small radius single walled carbon nanotube (SWCNT) were studied using density functional linear augmented plane wave (LAPW) method. Different electronic properties of a (4,0) zigzag SWCNT show this ultra‐small radius nanotube could not be extracted from the simple folding of a graphene. The calculated value for diameter of the tube is 3.364 Å, in good agreement with experimental results. Density of states and band structure results show the metallic character of (4,0) nanotube. A large van Hove peak near the Fermi energy due to large curvature is a good evidence for charge carriers to show superconductivity in a (4,0) nanotube. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Treatment of severe osteoporosis with alendronate in a patient with lysinuric protein intolerance
Authors: Gömez L. , García‐Cazorla A. , Gutiérrez A. , Artuch R. , Varea V. , Martín J. , Pinillos S. , Vilaseca M. A. 
Published: July 2006

SummaryLysinuric protein intolerance is an inborn error of cationic amino acid transport of which osteoporosis is a major feature. Treatment with oral bisphosphonates improves bone mineral density even in severe osteoporosis.
Density‐dependent egg mortality in early stages of gall induction by the fruit gall midge Asphondylia aucubae Yukawa and Ohsaki
Authors: Imai Kensuke , Ohsaki Naota 
Published: July 2006

AbstractDensity‐dependent mortality has been considered a symptom of intraspecific competition. We examined the occurrence of such mortality in the early stages of gall induction by the gall midge Asphondylia aucubae Yukawa et Ohsaki (Diptera: Cecidomyiidae). Female midges deposit eggs into young fruit of the dioecious shrub Aucuba japonica Thunberg to induce gall formation. Each host fruit received 0–67 eggs (mean 18.5 eggs) from multiple females, whereas established galls each contained one to ten larvae. Midges suffered intense mortality (65–90%) at the egg stage. Egg mortality occurred even in fruit in which no larvae had hatched, suggesting that this mortality cannot be wholly attributed to larval interference. Egg mortality was affected by fruit size, i.e., resource capacity. Midges distributed more eggs in larger fruit. Egg mortality increased as the per‐fruit density increased relative to fruit size. In contrast, the mortality of hatchlings was density‐independent. Our results suggest that A. aucubae intensely compete for gall‐induction substrates, which are spatiotemporally rare resources.