bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone Morphometry Strongly Predicts Cortical Bone Stiffness and Strength, but Not Toughness, in Inbred Mouse Models of High and Low Bone Mass
Authors: Voide Romain , van Lenthe G Harry , Müller Ralph 
Published: March 2008

Abstract
Inbred strains of mice make useful models to study bone properties. Our aim was to compare bone competence and cortical morphometric parameters of two inbred strains to better determine the role of bone structure and geometry in the process of bone failure. Morphometric analysis was performed on 20 murine femora with a low bone mass (C57BL/6J; B6) and 20 murine femora with a high bone mass (C3H/HeJ; C3H) using desktop μCT. The bones were tested under three-point bending to measure their mechanical properties. Results showed that the C3H strain is a more reproducible model regarding bone morphometric and mechanical phenotypes than the B6 strain. Bone strength, stiffness, yield force, yield displacement, and toughness, as well as morphometric traits, were all significantly different between the two strains, whereas postyield displacement was not. It was found that bone volume, cortical thickness, and cross-sectional area predicted almost 80% (p &lt; 0.05) of bone stiffness, strength, and yield force. Nevertheless, cortical bone postyield properties such as bone toughness could not be explained by morphometry, but postyield whitening was observed in that phase. In conclusion, we found that morphometric parameters are strong predictors of preyield but not postyield properties. The lack of morphometric influence on bone competence in the postyield phase in combination with the observed postyield whitening confirmed the important contribution of ultrastructure and microdamage in the process of overall bone failure behavior, especially in the postyield phase.
A methodological framework supporting trans-boundary water agreements: the case of the Nestos/Mesta river basin
Authors: Eleftheriadou Eleni , Mylopoulos Yannis 
Published: March 2008

Management of trans-boundary river basins is a major issue that has attracted great attention in recent years. The European Water Framework Directive (WFD) recommends management at a river basin level, overlooking any national or administrative borders. This new managerial approach impels water managers to disregard the trans-boundary nature of the water resources while considering an integrated river basin where only geographical boundaries exist.
The new challenge for scientists and water managers is the establishment of water agreements between countries sharing water resources. These agreements should aim at the settlement of tensions and conflicts while providing the essential framework for cooperation and consensus building. Apparently, the content of these agreements should comply with international law and the relevant international conventions especially, as noted by the WFD, the UNECE Convention on the Protection and Use of Trans-boundary Watercourses and International Lakes (known as the Helsinki Rules), approved by the European Council in 1995.
This paper examines the efficiency of water agreements and their precedent negotiations using the best known international examples while focusing on the Greek–Bulgarian agreement for the waters of the Nestos/Mesta River and its compliance with the WFD and the Helsinki Rules. As shown, the two countries have failed to implement a joint effort to put it into action; hence a methodological framework is proposed including certain strategic steps that can guide the two countries to a more effective and applicable water agreement taking into account the peculiarities of this trans-boundary area.
Autonomy of (Vocational) Schools as an Answer to Structural Changes
Authors: Spöttl Georg 
Published: March 2008

In Europe a very intensive discussion is in full swing as to whether vocational schools should in future be guided and monitored by the state or whether they should be freed from state dependency. Within the framework of a number of pilot projects in German-speaking countries, vocational school centres are currently testing their autonomy. This article sketches out the discussion on a way forward. Adopting a learner-centred perspective showed that formal education and training provide only a small part of what is learned at work. Most of the learning described by the interviewees was non-formal, neither clearly specified nor planned. It arose naturally out of the demands and challenges of work, solving problems, improving quality and/or productivity, or coping with change – and out of social interactions in the workplace. The outcome of such ‘learning from experience’ was the development of knowledge, skills and understanding, although this was difficult to explain to others. Effective learning was, however, dependent on confidence, motivation and capability – prerequisites for employees’ self-management of much of their learning. (Michael Eraut et al, 1998, p. 10ff).
Nonlinear wave interactions in patterned Silica and AlGaAs waveguides
Authors: Linzon Yoav , Malomed Boris , Zaezjev Michael , Morandotti Roberto , Volatier Maite , Aimez Vincent , Ares Richard , Bar-Ad Shimshon 
Published: March 2008

Abstract
We study nonlinear interactions between discrete optical solitons that propagate in different regimes of diffraction, and the nonlinear scattering of dispersive waves by local optical potentials. It is well known in optics that when linear coherent waves meet, they interfere without interactions. Linear waves also scatter through local optical structures not exchanging any power with the guided modes of these structures. As a focusing Kerr nonlinearity is present, such linearly-inhibited phenomena can exist. Our studies are performed in silica and AlGaAs nonlinear waveguides, excited by ultra-short pulses in the near infrared.
Modes of Engagement in Foreign Language Writing: An Activity Theoretical Perspective
Authors: Haneda Mari 
Published: March 2008

Abstract:This article makes the case for using activity theory to explore the learning and teaching of writing in a foreign language. I illustrate my argument by bringing this theory to bear on a re-examination of the different modes of engagement in writing by university-level students of Japanese as a foreign language that I identified in an earlier study. The first half of the article develops a perspective on writing as a social activity/practice, building on an interdisciplinary body of work and focusing particularly on activity theory. The different modes in which students engaged in writing in my earlier study are then interpreted from this perspective. I examine these modes both synchronically and diachronically in order to explore the students’ underlying values and attitudes with respect to learning the target language, suggesting that an activity-theoretical perspective can be a useful heuristic for the systematic detection of problems in writing that foreign language learners may encounter, so that instruction can be tailored to their needs.
The More Knowledgeable Peer, Target Language Use, and Group Participation
Authors: Huong Le Pham Hoai 
Published: March 2008

Abstract:Vygotsky proposed the concept of the zone of proximal development (ZPD) but did not elaborate the concept of ‘peer,’ leaving open the question of how capable a peer should be and how practice or outcome might differ according to a peer's level of capability. These issues were investigated in a sociocultural study of first-year Vietnamese university students learning English. The students were examined in two group settings, ‘unassisted’ and ‘assisted,’ the first consisting of five students from the same class and the second of four from the same class and a more knowledgeable student from a higher class. The senior student made a marked difference to the organization of the assisted group's processes: she helped the other students start their discussions, explained new English words, and increased the use of English in this group setting. The results suggest that the teaching manner of the senior student contributed substantially to the group work in the current study.
Changes in the field‐layer of Wytham Woods ‐ assessment of the impacts of a range of environmental factors controlling change
Authors: Corney P.M. , Kirby K.J. , Le Duc M.G. , Smart S.M. , McAllister H.A. , Marrs R.H. 
Published: March 2008

AbstractQuestion:What are the impacts of factors controlling patterns of change in woodland field‐layer vegetation, through time?Location:Wytham Woods, Oxford, UK (51°4i'N, 1°19'W).Methods:Species occurrence was monitored in 163 permanent plots three times between 1973 and 2002 and related to management compartment and history. The dataset was analysed using a combination of ordination methods, univariate and multivariate analysis of variance and HOF modelling.Results:The two key findings of this paper are: (1) that the species composition of ancient woodlands (often cited as a conservation goal), may be moving along an‘undesirable’trajectory, from a conservation viewpoint; and (2) that the impact of a synergistic effect of changing canopy dynamics, nitrogen deposition and a rising deer population has resulted in an increase in grass species, at the expense of woodland herbs. These findings have significant implications for the practical conservation of similar habitats across Europe.Conclusions:The analytical methodology presented here allowed detailed assessment of the potential roles of a range of environmental factors controlling change. The methodology may be applicable to other long‐term studies of vegetation, and is particularly appropriate for identification of cross‐site drivers, such as pollutant load and climate change.
Continuous Aspect‐Ratio Tuning and Fine Shape Control of Monodisperse α‐Fe2O3 Nanocrystals by a Programmed Microwave–Hydrothermal Method
Authors: Hu Xianluo , Yu Jimmy C. 
Published: March 2008

AbstractA rapid and economical route based on an efficient microwave–hydrothermal process has been developed to synthesize monodisperse α‐Fe2O3 nanocrystals with continuous aspect‐ratio tuning and fine shape control, which takes advantage of microwave irradiation and hydrothermal effects. This method easily programs the experimental conditions (e.g., temperature and time) and significantly shortens the synthesis time to minutes. It allows the creation of numerous recipes for optimizing and scaling up production. The effects of experimental conditions including reaction temperature and reactant concentration on the morphology of α‐Fe2O3 have been investigated systematically. Results reveal that the initial molar ratio of Fe3+ to PO plays a crucial role in the final morphology of the α‐Fe2O3 products. Several morphologies, which include ellipsoids/spindles with aspect ratios that range from 1.1 to 6.3, nanosheets, nanorings, and spheres can be obtained. The as‐formed α‐Fe2O3 exhibits shape‐dependent infrared optical properties. The growth process of colloidal α‐Fe2O3 crystals in the presence of phosphate ions is discussed. The products have been characterized by using X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and infrared spectroscopy. This work presents an efficient and cost‐effective approach that is potentially competitive for scaling‐up industrial production. The as‐formed α‐Fe2O3 crystals with controllable morphologies not only provide flexible building blocks for advanced functional devices, but are also ideal candidates for studying their nanoarchitecture‐dependent performance in optical, catalytic, and magnetic applications.
Self‐assembled Cationic Peptide Nanoparticles Capable of Inducing Efficient Gene Expression In Vitro
Authors: Wiradharma Nikken , Khan Majad , Tong Yen Wah , Wang Shu , Yang Yi‐Yan 
Published: March 2008

AbstractIn this study, cationic and amphiphilic oligopeptides, (A)12(H)5(K)10 (AK27) and (A)12(H)5(K)15 (AK32), were designed and tested as a nonviral gene vector. The oligopeptides had critical micelle concentrations (CMC) of 0.9 and 1.1 mg mL−1 respectively, indicating that they were able to self‐assemble into core–shell nanoparticles at concentrations above the CMC value, which was confirmed by electron microscopy. The nanoparticles were cubic and had an effective diameter of 700–900 nm, as well as a zeta potential of 18 to 20 mV. The formation of nanoparticles increased the local concentration of cationic charge in the solution, leading to improved DNA binding ability and better protection from enzymatic degradation compared to the control peptide (H)5(K)10 (HK15) without a hydrophobic block. The smallest effective diameters of AK27–DNA and AK32–DNA complexes were 442 and 332 nm, respectively, and the highest zeta potentials were 7.8 and 18.2 mV, respectively. In comparison, HK15 formed much larger DNA complexes with a nearly neutral zeta potential. Cytotoxicity tests showed that HEK293, HepG2, and 4T1 cell lines had viabilities of more than 80% after incubation with AK27 and AK32 peptides, which was much higher than that obtained from polyethyleneimine (PEI) incubation. Furthermore, an increased length of lysine block, and the presence of the hydrophobic block did not show any significant increase in cytotoxicity. More importantly, AK27 and AK32–DNA complexes induced much higher luciferase expression efficiency than KH15 in all three cell lines tested. AK32 with a longer lysine block led to more efficient gene expression than AK27. In addition, the gene‐expression levels mediated by AK32 nanoparticles were comparable to those provided by PEI, especially in HepG2 and 4T1 cell lines. These cationic nanoparticles made from biodegradable and biocompatible peptides may provide a promising carrier for gene delivery.
A Facile Strategy for Preparation of Fluorescent SWNT Complexes with High Quantum Yields Based on Ion Exchange
Authors: Fu Chuanlong , Meng Lingjie , Lu Qinghua , Fei Zhaofu , Dyson Paul J. 
Published: March 2008

AbstractThe fluorescent imidazolium salt (1,3‐bis(9‐anthracenylmethyl)imidazolium chloride, [bamim]Cl) has been grafted onto the surfaces of single‐walled carbon nanotubes (SWNTs) using an ion exchange strategy based on metathesis of the K+ ion in CO2K derivatized SWNTs with [bamim]+. The resulting SWNT‐[bamim] complex has been characterized with high‐resolution transmission electron microscopy (HR‐TEM), X‐ray photoelectron spectroscopy (XPS), elemental mapping, and elemental linear profiles analysis. A blue light emission can be observed at 392, 414 and 438 nm for SWNT‐[bamim] upon being excited at 254 nm. The quantum yield (QY) of the SWNT‐[bamim] complex (0.40) is much higher than that of SWNT/[bamim]Cl (0.02), used as a control, and prepared using a π‐π stacking method, indicating that ion exchange is a far more effective strategy for retaining a high QY. Additionally, UV‐Vis‐NIR and Raman spectroscopy show that the SWNT‐[bamim] complex can maintain the one‐dimensional electronic states of SWNTs. Other imidazolium salts have also been successfully grafted onto SWNTs via the same strategy, indicating that the ion exchange process can serve as a universal strategy for the functionalization of SWNTs.
Evaluation of juvenile stature and body mass prediction
Authors: Sciulli Paul W. , Blatt Samantha H. 
Published: March 2008

AbstractThis investigation evaluates the performance of juvenile stature (from tibia and radius lengths) and body mass (from breadth of the femoral distal metaphysis) prediction equations based on the Denver Growth Study sample (Ruff C. 2007. Am J Phys Anthropol 133 698–716). The sample used here for evaluation is an independent sample of juveniles brought to the Franklin County (Ohio) Coroner in 1990–1991. The Ohio sample differs somewhat from the Denver reference sample: it includes ∼25% African‐Americans (rather than all European‐Americans), a significant number of right limb bones were measured (rather than all left side), it includes a wider range of economic statuses and it includes individuals who died from disease and trauma. As such the composition and measures of the Ohio sample correspond more generally to that seen in skeletal samples so that the accuracy of the estimates from the present sample should approach those found in practical applications of these methods. Results indicate that both juvenile body mass and stature are estimated relatively accurately. Accuracy of body mass estimates for 1‐13‐year‐old juveniles is similar for African‐American and European‐American males and females. The least accurate estimates are for individuals in the 8–13 years age class (excluding individuals with body mass indices greater than the age specific 95th percentile): n = 9, ± 2.9 kg, 95% confidence interval 1.4–4.4 kg. Accuracy of stature estimates for 1‐17‐year‐old juveniles is comparable for the tibia and radius and, as with body mass estimates, are similar for African‐American and European‐American males and females. For combined age, sex, and ancestry groups average accuracies are in the ±3.5 to ±6.5 cm range. Some limitations of the methods are discussed. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Cell‐specific alterations of glutamate receptor expression in tuberous sclerosis complex cortical tubers
Authors: Talos Delia M. , Kwiatkowski David J. , Cordero Kathia , Black Peter M. , Jensen Frances E. 
Published: March 2008

AbstractObjectiveGenetic loss ofTSC1/TSC2function in tuberous sclerosis complex (TSC) results in overactivation of the mammalian target of rapamycin complex 1 pathway, leading to cellular dysplasia. We hypothesized that the dysplastic cells in TSC tubers are heterogeneous, including separable classes on a neuronal‐glial spectrum, and that these dysplastic cells express glutamate receptor (GluR) patterns consistent with increased cortical network excitability.MethodsSurgically resected human cortical tubers and nondysplastic epileptic cortical samples were analyzed by double‐label immunocytochemistry for coexpression of neuronal and glial markers, the TSC1/TSC2 pathway downstream molecule phospho‐S6 (pS6) and GluR subunits, and compared with control cortical tissue. Western blotting was used to quantify changes in GluR subunit expression in tubers versus controls.ResultsWe demonstrate that cortical tubers contain a broad spectrum of cell types including disoriented pyramidal cells, dysplastic neurons, giant neuroglial cells, dysplastic astroglia, and reactive astrocytes. Dysplastic neurons, giant cells, and dysplastic astroglia express high levels of pS6 and demonstrate altered GluR subunit composition, resembling those of normal immature neurons and glia. In contrast, nondysplastic neurons in TSC and non‐TSC epileptic lesions express lower pS6 levels and display changes in GluR subunit expression that are distinct from the patterns seen in tuber dysplastic cells.InterpretationThis work significantly expands the spectrum of abnormal cells recognized in tubers beyond the classic tuber giant cell and demonstrates cell‐specific abnormalities in GluR expression that may contribute to seizure pathogenesis in TSC. Furthermore, these results suggest that subunit‐specific antagonists may be of potential use in the treatment of epilepsy in TSC. Ann Neurol 2008
Combinatorial Transition‐Metal Catalysis: Mixing Monodentate Ligands to Control Enantio‐, Diastereo‐, and Regioselectivity
Authors: Reetz Manfred T. 
Published: March 2008

AbstractThis review focuses on a new approach to combinatorial homogeneous transition‐metal catalysis which goes beyond the traditional parallel preparation of modular ligands. It is based on the use of mixtures of monodentate ligands La and Lb, which upon exposure to a transition metal (M) form not only the two homocombinations [MLaLa] and [MLbLb], but also the heterocombination [MLaLb]. If the latter is more reactive and selective than the homocombinations, an improved catalyst system is formed without the need to synthesize new ligands. Thus, the control of enantio,‐ diastereo‐, and regioselectivity is possible.
Influence of ozone on chemical reactions during the stabilization of polyacrylonitrile as a carbon fiber precursor
Authors: Hou Yongping , Sun Tongqing , Wang Haojing , Wu Dong 
Published: March 2008

AbstractChemical shrinkage was used for the in situ measurement of the progressing chemical stabilization reactions and the influence of ozone during the stabilization of polyacrylonitrile. A method for evaluating the activation energy through the sensitivity temperature is presented. The calculated results show that the activation energies were 161.57 kJ/mol in air and 181.23 kJ/mol in ozone‐enriched air. Therefore, the chemical reactions were postponed during stabilization in ozone‐enriched air. Ozone seemed to act in three ways: first, ozone promoted the formation of the serious skin–core structure. Second, ozone accelerated the chemical reactions and shortened the stabilization time at lower heating rates. Third, ozone postponed the chemical reactions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Moisture absorption behavior of epoxies and their S2 glass composites
Authors: Chatterjee Amit , Gillespie John W. 
Published: March 2008

AbstractThe influence of moisture exposure on the behavior of three toughened epoxy–amine systems (scrimp resins SC11, SC15, and SC79, Applied Poleramic, Inc., Benicia, CA) was investigated. Neat resin samples were conditioned by immersion in distilled water at 71°C and in an environmental chamber at 85% relative humidity and 87.8°C until saturation. The equilibrium weight gain ranged from 1.8 to 3.8% for the resins. The long‐chain, low‐crosslink‐density epoxy system (SC11) absorbed the highest amount of water and was saturated first, and it was followed by the medium‐crosslink‐density (SC15) and high‐crosslink‐density materials (SC79). The moisture diffusivity decreased with the increasing crosslink density of the resins. The percentage reduction of the glass‐transition temperature (Tg) at equilibrium moisture absorption was highest for the low‐crosslink molecule. The percentage reductions for the medium‐crosslink and higher crosslink systems were comparable. A net weight loss after drying was observed for the SC11 and SC79 resin systems. Fourier transform infrared analysis confirmed the segment breakage and leaching of molecules from the epoxy–amine network. The effects of moisture cycling on Tg were dependent on the epoxy–amine morphology. During the drying stage, Tg increased to a value higher than that of the unaged dry systems. The S2 glass composite samples were conditioned under identical conditions for the resin system. Composite systems absorbed less moisture than the neat resins as expected. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
HPLC‐fluorescence assay for acyclovir in children
Authors: Zeng L. , Nath C. E. , Shaw P. J. , Earl J. W. , McLachlan A. J. 
Published: March 2008

AbstractA simple, accurate, reliable and sensitive HPLC method was developed and validated for quantitating acyclovir in human plasma. Sample (100 µL) preparation involved addition of guanosine (internal standard) and protein precipitation with 7% perchloric acid and centrifugation. Supernatant (20 µL) was injected onto a C18 HPLC column with a mobile phase of 0.05 m sodium phosphate buffer–acetonitrile (pH 2.35, 992:8, v/v) with 25 µL of 0.4 m tetrabutylammonium hydroxide titrant and fluorescence detection (excitation, 260 nm; emission, 375 nm). Analyte recovery was 101% and the assay response was linear over the acyclovir concentration range of 0.1–20 mg/L. Intra‐ and inter‐day accuracy and precision were less than 7%. The limit of detection and limit of quantitation were 0.033 and 0.1 mg/L, respectively. In five paediatric oncology patients administered intravenous acyclovir, concentrations ranged from 0.24 to 43.65 mg/L. This method can be used to measure acyclovir concentrations in paediatric patients. Copyright © 2008 John Wiley & Sons, Ltd.