bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the amount of valgus correction for medial compartment knee osteoarthritis on clinical outcome, knee kinetics and muscle co‐contraction after opening wedge high tibial osteotomy
Authors: Briem Kristin , Ramsey Dan K. , Newcomb William , Rudolph Katherine S. , Snyder‐Mackler Lynn
Published: December 2006

The goal of opening wedge high tibial osteotomy (HTO) is to reduce excessive loading on the medial compartment of the knee by correcting varus deformity, thereby reducing pain and improving function. Although surgical outcome is reportedly poor in cases of under‐ or overcorrection, the recommended alignment varies. The aim of this study was to investigate the effect of the degree of frontal plane knee alignment following open wedge HTO surgery on muscle co‐contraction, joint moments, and self‐reported functional outcome. Sixteen patients with medial compartment osteoarthritis (OA), who were scheduled for an opening wedge osteotomy, were recruited for participation in the study. Data were collected using an optoeletric motion analysis system and varus and valgus angulations of the knee were measured, using standing, long cassette, radiographs of the lower extremities. Results showed that physical function improved significantly overall (p < 0.001). However, those subjects whose knee alignment was further away from the group's postoperative mean tended to improve less in their Knee Outcome Survey‐Activities of Daily Living Scale (KOS‐ADLS) scores than those closer to the mean (p = 0.07). They also had higher medial and lateral co‐contractions and higher adduction moments one year after surgery (p ≤ 0.009 and p = 0.048, respectively) and were more likely to show a change towards increased medial muscle co‐contraction following surgery, when compared to presurgical values. This outcome may contribute to accelerated degeneration of the knee for this group of people. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
A colorimetric study of oenin copigmented by procyanidins
Authors: Berké Bénédicte , de Freitas Victor
Published: December 2006

A colorimetric method was used to analyse the influence of procyanidin structure on colour changes of malvidin 3‐O‐glucoside (oenin) solution resulting from copigmentation. The study was performed in hydroalcoholic citrate/phosphate buffer solution (120 g L−1) at pH 3.6 and ionic strength 0.2 mol L−1. Chromatic L*, a* and b* coordinates (CIELAB, D65/10° illuminant/observer condition) obtained from spectral curves recorded between 360 and 830 nm allowed the calculation of lightness L*, chroma C* and hue angle hab. In general, addition of copigment induced colour enhancement (loss of lightness and increased chroma). The prevailing parameters affecting colour changes were lightness and chroma for monomers and lightness and hue for procyanidins B5 and B8 (C4–C6 dimers). A small blueing effect was observed only for catechin monomer‐copigmented solutions. For procyanidin copigments, as the structural complexity of the copigment increased, the hue angle moved to yellower values. The ester gallate of dimer B2 produced the strongest modification of colour attributes of oenin solution. Copyright © 2006 Society of Chemical Industry
Effects of plastic film mulching cultivation under non‐flooded condition on rice quality
Authors: Lu Xinghua , Wu Lianghuan , Pang Linjiang , Li Yongshan , Wu Jianguo , Shi Chunhai , Zhang Fusuo
Published: December 2006

Plastic film mulching cultivation under non‐flooded condition (PFMC), a new high‐efficiency and water‐saving cultivation technique, has been adopted and developed in many regions of china since the 1980s. Field experiments were conducted to evaluate the effects of PFMC on rice quality in three agro‐ecosystems (plain, basin and mountainous area) in 2001. The experiment consisted of three treatments, which were conventional flooded cultivation (CFC), PFMC and non‐mulching cultivation (NMC) under non‐flooded condition in a randomized complete block design with three replications. Compared with CFC, PFMC increased head‐milled rice recovery (with the exception of plain area), rice transparency and alkali spreading value, but slightly decreased gel consistency and obviously decreased chalky grain rate. Compared with NMC, those quality traits under PFMC were changeable at different sites. There were no significant differences for brown rice rate (except hilly area), milling rice quality and amylose content across treatments. In addition, nutritional quality under PFMC was notably improved in comparison with CFC and NMC. With few exceptions, the protein content, total amino acid content, individual amino acid content and Lys content of rice decreased in the order of PFMC > NMC > CFC. In general, rice quality is affected by each agro‐ecosystem and cultivation system to different degrees. PFMC had more influence on rice quality in hilly region than plain and basin regions. Copyright © 2006 Society of Chemical Industry
A coupled system for electrical circuits. Numerical simulations
Authors: Selva Soto Monica
Published: December 2006

We are interested in the numerical simulation of electrical circuits modelled by a coupled system of differential algebraic equations and partial differential equations. The partial differential equations describe the semiconductor devices in the circuit. When solving this problem numerically we discretize in space the partial differential equations in the system and solve the resulting differential algebraic equation. In this paper a brief description of the model is given and some of its properties are presented. Some numerical simulations are also shown. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solar cell efficiency tables (version 29)
Authors: Green Martin A. , Emery Keith , King David L. , Hishikawa Yoshihiro , Warta Wilhelm
Published: December 2006

Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since June 2006 are reviewed. Copyright © 2006 John Wiley & Sons, Ltd.
Rheology of isothermally crystallized poly(butylene terephthalate) nanocomposites with clay loadings under the percolation threshold
Authors: Wu Defeng , Zhou Chixing , Zhang Ming
Published: December 2006

This article describes the structural evolution of clay in poly(butylene terephthalate) nanocomposites (PCNs) with clay loadings lower than the percolation threshold during the isothermal crystallization process. The study of the structure and rheological properties has revealed that the intercalation and detachment levels of clay are enhanced in samples crystallized at a high temperature (210 °C), in contrast to those of the original PCN, and this results in the formation of a rheological percolation network. However, for PCNs crystallized at a low temperature (190 °C), the further structural evolution of the tactoids is very small. All the experimental results indicate that the morphologies of clay can further evolve during the crystallization process, but the evolution level is strongly dependent on the crystallization temperature. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 229–238, 2007
Nornicotine inhibition of dopamine transporter function in striatum via nicotinic receptor activation
Authors: Middleton Lisa S. , Crooks Peter A. , Wedlund Peter J. , Cass Wayne A. , Dwoskin Linda P.
Published: December 2006

Nornicotine, a tobacco alkaloid andN‐demethylated nicotine metabolite, releases DA from superfused rat striatal slices in a mecamylamine‐sensitive manner, indicating nicotinic receptor (nAChR) modulation of this response. The current study determined the effect of nornicotine on rat striatal dopamine transporter (DAT) function using in vivo voltammetry. In a dose‐related and mecamylamine‐sensitive manner, nornicotine (0.35–12.0 mg/kg, s.c.) decreased DA clearance, suggesting that nornicotine inhibits striatal DAT function via a nAChR–mediated mechanism. Furthermore, the nAChRs mediating the nornicotine‐induced inhibition of DAT function appear to be different from those activated by nicotine which increases DA clearance. Understanding the actions of nornicotine in brain may have significance for emerging therapeutics and for the management of nicotine dependence. Synapse 61:157–165, 2007. © 2006 Wiley‐Liss, Inc.
Instantaneous self-fulfilling of long-term prophecies on the probabilistic distribution of financial asset values
Authors: Lions P.-L. , Lasry J.-M.
Published: December 2006

Our goal here is to present various examples of situations where a “large” investor (i.e. an investor whose “size” challenges the liquidity or the depth of the market) sees his long-term guesses on some important financial parameters instantaneously confirmed by the market dynamics as a consequence of his trading strategy, itself based upon his guesses. These examples are worked out in the context of a model (i.e. a quantitative framework) which attempts to provide a rigorous basis for the qualitative intuitions of many practitioners. Our results may be viewed as some kind of reverse Black–Scholes paradigm where modifications of option prices affect today's real volatility.
Questionnaire ratings of attention-deficit/hyperactivity disorder (ADHD) in adults are associated with spatial working memory
Authors: Dowson Jonathan H. , Blackwell Andrew D. , Turner Danielle C. , Harvey Elizabeth , Malhotra Tina , Robbins Trevor W. , Sahakian Barbara J.
Published: December 2006

Objective

Data related to brain function may have the potential to improve the reliability and validity of assessments for the aetiologically and clinically heterogeneous syndrome of attention-deficit/hyperactivity disorder (ADHD). This study investigated associations between questionnaire assessments of behavioural features of adults with ADHD and an aspect of neurocognitive performance which has been reported to be impaired in adults with ADHD.

Methods

Fifty-nine adult patients with a DSM-IV diagnosis of ADHD, and their informants, completed questionnaires related to aspects of severity of ADHD. Associations were examined between questionnaire ratings and performance on a computer-administered task of spatial working memory (SWM).

Results

Correlations between ratings of ADHD and SWM indicated moderate but significant correlations for patients' ratings, but not for informants' ratings. Also, patients who reported a past history of ‘self-harm’ (N = 33) had a significantly worse mean performance on both measures of SWM (p = 0.004, 0.003).

Conclusions

The results indicate that aspects of impulsivity, i.e. self-ratings of ‘emotive’ behaviour (involving rapid response to stimuli and marked reactivity of mood) and of past ‘self-harm’, show relatively strong associations with SWM performance in adults selected on the basis of an ADHD diagnosis. A profile of neurocognitive performances may have a role in the assessment of ADHD.
Familial aggregation of depression, but no familial aggregation of individual depressive symptoms
Authors: Heun Reinhard , Hein Sandra
Published: December 2006

Background

Familial aggregation of major depression might indicate a genetic liability for the disorder. The complete disorder or, alternatively, only some individual symptoms might be inherited. Under the latter condition, an increased frequency of inherited symptoms might consecutively increase the likelihood to reach the threshold for depression in relatives and, thus, might cause the familial aggregation of depression. Up to now, no study investigated the possibility of a relationship between individual depressive symptoms and the familial aggregation of depression.

Methods

The familial aggregation of early-onset depression (age-at-onset < 60 years, EOD) but less so of late-onset depression (LOD) has been shown in this sample. To assess the hypothesis of an inheritance of individual depressive symptoms as a possible cause of the familial aggregation of depression, frequencies of symptoms were compared in relatives of depressed patients and of controls using forward logistic regression analyses.

Results

Some individual depressive symptoms showed clustering in relatives of patients with depression, but the pattern of inheritance was inconsistent, i.e. the clustering of symptoms was different between non-depressed and depressed relatives of patients with EOD and LOD, respectively. No intra-familial clustering of specific depressive symptoms within families of depressed subjects could be observed.

Conclusions

Due to the inconsistencies in the clustering of individual symptoms in non-depressed and depressed relatives and the lack of intra-familial clustering, the familial aggregation of depression is unlikely to be caused by the aggregation of individual depressive symptoms. An inheritance of the vulnerability for complete depressive disorders influenced by environmental factors is more likely.
Overnight urinary cortisol release in women with borderline personality disorder depends on comorbid PTSD and depressive psychopathology
Authors: Wingenfeld Katja , Driessen Martin , Adam Bettina , Hill Andreas
Published: December 2006

Free cortisol was investigated in BPD patients and healthy controls. A positive association was found between cortisol and depression scores, while the number of PTSD symptoms was negatively correlated with cortisol release. These findings suggest that alterations in cortisol release in BPD are strongly associated with the severity of psychopathology.
Evaluation of multiple management objectives for Northeast Atlantic flatfish stocks: sustainability vs. stability of yield
Authors: Kell L.T. , Pastoors M.A. , Scott R.D. , Smith M.T. , Van Beek F.A. , O'Brien C.M. , Pilling G.M.
Published: December 2006

This paper describes a simulation study that evaluated the ICES scientific advisory process used to recommend total allowable catches (TACs) for flatfish stocks. Particular emphasis is given to examining the effects on stock biomass, yield and stability of constraining interannual variation in TACs. A “management strategy evaluation” approach is used where an operating model is used to represent the underlying reality, and pseudo data are generated for use within a management procedure. The management procedure comprises a stock assessment that uses data to estimate parameters of interest and a decision rule to derive TAC recommendations for the following year. Bounds on TAC of between 20% and 40% have little effect on yields or stability, while a 10% bound on TAC can affect the ability to achieve management targets and result in low-frequency cycling in the stock. In the short term, performance is highly dependent on current stock status but bounds have less effect if the stock is close to equilibrium for a target fishing mortality (F). In addition, it was shown that current ICES biomass and fishing mortality reference points are not always consistent, and several are clearly inappropriate. Importantly, including realistic sources and levels of uncertainty can result in far from optimal management outcomes based on the current procedures. Results also conflicted with expert opinion, in suggesting that management based on a fixed F regime could result in relatively stable yields despite fluctuations in year-class strength and that the management feedback process itself is implicated in causing fluctuations in the system due to significant time-lags in this process. We therefore emphasize that providing more precise population estimates or developing harvest control rules alone will not necessarily help in achieving management objectives, rather management procedures that are robust to uncertainty and tuned to meet management objectives need to be developed. Operating models in these simulations were constrained to be based on existing ICES methods and perceptions of stock dynamics, but we recommend that, in future, operating models that represent the best available understanding of the actual system dynamics be used to evaluate models and rules considered for application.
The expression and binding of kainate receptors is modified in different brain regions by glutamate neurotoxicity during postnatal rat development
Authors: Beas‐Zárate C. , Ureña‐Guerrero M.E. , Flores‐Soto M. , Armendariz‐Borunda J. , Ortuño‐Sahagún D.
Published: December 2006

Kainic acid receptor (KA‐R) subunits are differentially expressed during brain development, and they modulate both neural growth and survival. High concentrations of glutamate in the brain can induce neuronal injury through these receptors, altering normal development. However, it is unclear whether KAR subunit expression itself is also modified by neonatal exposure to high glutamate. To analyze this, monosodium glutamate (4 mg/g of body weight) was subcutaneously administered on postnatal days 1, 3, 5 and 7, and the expression of GluR5, GluR6, KA1 and KA2, as well as [3H]‐kainic acid (KA‐R) binding, was evaluated on postnatal days 14, 21, 30 and 60 in different regions of rat brain. As a result, high levels of GluR5 expression associated with strong [3H]‐kainic acid binding were observed on postnatal days 30 and 60 in the cerebral cortex of rats exposed to glutamate. Similarly, the changes induced by glutamate administration in the expression of the KA1 and KA2 subunits were paralleled by those of [3H]‐kainic acid binding in the striatum at postnatal days 21 and 30. In contrast, while KAR subunits were over expressed in the hippocampus, no changes were observed in [3H]‐kainic acid binding in adult rats that had been exposed to glutamate. Therefore, glutamate modifies both the expression of kainic acid receptor subunits and kainic acid binding in a determined spatial and temporal manner, which may be indicative of a regional susceptibility to glutamate neurotoxicity.
Customer expectations in online auction environments: An exploratory study of customer feedback and risk
Authors: Finch Byron J.
Published: December 2006

The importance of understanding the needs of the customer is a widely‐accepted pre‐requisite to providing quality products and services. For product purchases through traditional channels, customers are known to have expectations for the product they are buying as well as for the services associated with its purchase. Online transactions, in which the buyer has no prior knowledge of the seller, are becoming increasingly common and are fraught with risks not present in traditional channels. Feedback about sellers in these risky markets contains a mix of product‐related and service‐related comments. This exploratory study identifies preliminary relationships between customers’ emphases on product or service dimensions of quality in their feedback and the risks to which the customer is exposed.
Rhinoclemmysnema n. g. and three new species of nematodes of the family Atractidae (Cosmocercoidea), with notes on the helminth fauna of Rhinoclemmys pulcherrima (Testudines: Bataguridae) in Costa Rica
Authors: Gibbons L.M. , Platt T.R.
Published: December 2006

Rhinoclemmysnema n. g. and three new species of atractid nematodes, namely, Atractis costaricaensis n. sp., Orientatractis asymmetrica n. sp. and Rhinoclemmysnema multilabiatum were recovered from the small and large intestine of Rhinoclemmys pulcherrima, the painted wood turtle in the Guanacaste Conservation Area, Costa Rica. The genera and three species are characterized by the features of the cephalic region and male tail. Neopolystoma fentoni (conjuctival sac) and Heronimus mollis (lungs) were also collected.
Helminth communities of Nectomys squamipes naturally infected by the exotic trematode Schistosoma mansoni in southeastern Brazil
Authors: Júnior A. Maldonado , Gentile R. , Fernandes-Moraes C.C. , D'Andrea P.S. , Lanfredi R.M. , Rey L.
Published: December 2006

The water rat Nectomys squamipes is endemic in Brazil and found naturally infected with Schistosoma mansoni. Helminth communities, their prevalences, intensity of infection and abundance in N. squamipes in an endemic area of schistosomiasis in the state of Rio de Janeiro, Brazil were studied. Four species of nematodes (Physaloptera bispiculata, Syphacia venteli, Hassalstrongylus epsilon and Litomosoides chagasfilhoi) were recovered in 85.3%, two trematodes (Schistosoma mansoni and Echinostoma paraensei) in 38.8% and one cestode species (Raillietina sp.) in 1.7% of rats examined. Rats were infected with up to five helminth species each, and these were highly aggregated in distribution. For H. epsilon and S. venteli, intensities and abundances were higher in adult male and subadult female hosts, respectively. Hassaltrongylus epsilon, P. bispiculata, S. venteli and S. mansoni were classified as dominant species, L. chagasfilhoi and E. paraensei as co-dominant and Raillietina sp. as subordinated. No significant correlation was found in the intensity of infecton between each pair of helminth species. Schistosoma mansoni was not related to any other helminth species according to their infection rates, althougth S. mansoni was well established in the natural helminth comunity of the water rat.
The effect of an indirect anthelmintic treatment on parasites and breeding success of free-living pheasants Phasianus colchicus
Authors: Draycott R.A.H. , Woodburn M.I.A. , Ling D.E. , Sage R.B.
Published: December 2006

In Great Britain free-living common pheasants Phasianus colchicus are often managed at high densities owing to their popularity as a quarry species. They are prone to infection by a range of parasite species including Heterakis gallinarum, Capillaria spp. and Syngamus trachea. In 1995 the efficacy of an indirect anthelmintic technique for controlling parasitic worm burdens of pheasants was determined in a pilot study on a shooting estate in the south of England. Between 2000 and 2003 a large-scale field experiment was conducted on nine estates in eastern England to determine the effect of the technique on parasite burden and pheasant breeding success. In the absence of anthelmintic treatment worm burdens increased rapidly through March and April, whereas birds given anthelmintic-treated grain had lower worm burdens during the same period. The breeding success of pheasants was significantly higher on plots provided with anthelmintic treatment, although no long-term increases in population densities were observed. The burdens of the most common parasite H. gallinarum were significantly lower in pheasants from treatment plots six weeks after the anthelmintic treatment had ceased, but spring treatment did not influence parasite burden in the following winter.
The ultrastructure of hypersymbionts on the monogenean Gyrodactylus salaris infecting Atlantic salmon Salmo salar
Authors: Bakke T.A. , Cable J. , Østbø M.
Published: December 2006

There is increasing pressure to develop alternative control strategies against the pathogen Gyrodactylus salaris, which has devastated wild Atlantic salmon Salmo salar in Norway. Hyperparasitism is one option for biological control and electron microscopy has revealed two ectosymbionts associated with G. salaris: unidentified rod-shaped bacteria, and the protist, Ichthyobodo necator. No endosymbionts were detected. The flagellate I. necator occurred only occasionally on fish suffering costiosis, whereas bacterial infections on the tegument of G. salaris were observed throughout the year, but at variable densities. Bacteria were seldom observed attached to fish epidermis, even when individuals of G. salaris on the same host were heavily infected. Wounds on salmon epidermis caused by the feeding activity of bacteria-infected G. salaris did not appear to be infected with bacteria. On heavily infected gyrodactylids, bacteria were most abundant anteriorly on the cephalic lobes, including the sensory structures, but no damaged tissue was detected by transmission electron microscopy in the region of bacterial adherence. Furthermore, transmission and survival of infected G. salaris on wild salmon did not appear to be influenced by the bacterial infection. The lack of structural damage and impact on G. salaris biology indicates that these bacteria are not a potential agent for control of gyrodactylosis. However, this may not be the case for all gyrodactylid–bacterial interactions and a review of bacterial infections of platyhelminths is presented.
Serodiagnostic potential of chemically synthesized glycosphingolipid antigens in an enzyme-linked immunosorbent assay for alveolar echinococcosis
Authors: Yamano K. , Hada N. , Yamamura T. , Takeda T. , Honma H. , Sawada Y.
Published: December 2006

In the serodiagnosis of alveolar echinococcosis, the detection of specific reactions against not only protein but also carbohydrate antigen is useful and both antigens supplement each other. Though recombinant protein antigens have recently advanced, the preparation of carbohydrate antigen still depends on extraction from crude antigens. In the latter case, it is not conventional to obtain carbohydrate antigen as a single component for examination and research. Therefore, chemically synthesized carbohydrate antigens were prepared for serodiagnosis by the enzyme-linked immunosorbent assay (ELISA). Four antigens with the structure of glycosphingolipids from Echinococcus multilocularis were examined and one antigen, Galβ1-6(Fucα1-3)Galβ1-6Galβ1-ceramide, was found to show significant serodiagnostic potential in differentiating alveolar from cystic echinococcosis.
Evaluation of broad-spectrum anthelmintic activity in a novel assay against Haemonchus contortus, Trichostrongylus colubriformis and T. sigmodontis in the gerbil Meriones unguiculatus
Authors: Ostlind D.A. , Cifelli S. , Mickle W.G. , Smith S.K. , Ewanciw D.V. , Rafalko B. , Felcetto T. , Misura A.
Published: December 2006

The gerbil Meriones unguiculatus, infected with three species of nematodes, each located in a separate part of the gastrointestinal tract, provided a reliable laboratory assay for the evaluation of broad-spectrum anthelmintic activity. Gerbils harbouring 6-day-old infections of Haemonchus contortus, Trichostrongylus colubriformis and T. sigmodontis were given selected broad-spectrum anthelmintics by gavage. Three benzimidazoles, thiabendazole, oxfendazole and albendazole, a tetrahydropyrimidine, morantel, an imidazothiazole, levamisole hydrochloride, a macrocyclic lactone, ivermectin and an experimental natural product, paraherquamide, were active against all three nematodes at various dosages. Trichostrongylus colubriformis was most sensitive to levamisole hydrochloride, morantel, thiabendazole and paraherquamide whereas ivermectin, oxfendazole and albendazole were more effective against H. contortus. All compounds were active against the caecal nematode T. sigmodontis although it was less sensitive than T. colubriformis. Haemonchus contortus was more sensitive than T. sigmodontis to all anthelmintics tested except thiabendazole.
ASSESSING THE ROLE OF AUTONOMOUS TEACHERS’ TRADE UNIONS IN ANGLOPHONE CAMEROON, 1959–1972
Authors: KONINGS PIET
Published: December 2006

In the literature on African trade unions during decolonization and in the immediate post-independence period, two schools of thought can be distinguished: one is pessimistic about the unions' economic and political roles, and the other is optimistic. This study attempts to assess the role of autonomous teachers' trade unions in Anglophone Cameroon during the period 1959–72. The emergence, development and dissolution of these unions appears to have closely followed the region's political and educational reforms. It is argued that two main issues formed a constant source of conflict between the government and these unions, namely the preservation of trade union autonomy, and union demands for a substantial improvement in members' conditions of service.
RAW YOUTH, SCHOOL-LEAVERS AND THE EMERGENCE OF STRUCTURAL UNEMPLOYMENT IN LATE-COLONIAL URBAN TANGANYIKA
Authors: BURTON ANDREW
Published: December 2006

This article examines the historical origins of one of urban Africa’s most visible contemporary problems, using Tanzania as a case study. The middle decades of the twentieth century are identified as a time when a pivotal shift occurred as labour scarcity gave way to over-supply, resulting in the emergence of enduring ‘structural’ unemployment. This was influenced by a combination of phenomena arising from the deepening impact of colonialism: including demographic growth leading to an increasingly youthful population, commoditisation and heightened African expectations influenced by socio-cultural and ideological factors. These were compounded by a shift in late-colonial labour policy towards stabilisation, which had the unintended effect of stymieing job creation. The latter part of the article describes the panicked response of the incoming African regime, faced with what they initially interpreted as a potentially insurrectionary class of urban unemployed. Closing remarks speculate on whether, in the longue durée, one may interpret unemployment in a more positive light as part of an ongoing wider historical transformation.
Legal Information Retrieval Study – Lexis Professional and Westlaw UK
Authors: Mason Dean
Published: December 2006

This article by Dean Mason looks at the retrieval effectiveness of the online legal research tools Lexis Professional and Westlaw UK and is the result of research carried out for his Masters Degree in Information Science.
CILIP Qualifications and You
Authors: Chapman Margaret
Published: December 2006

Paper given by Margaret Chapman at the 37th BIALL Annual Study Conference in Brighton, June 2006, outlining the new routes to qualified professional status including Certification; Chartership; Revalidation and Fellowship.
Wintertime sea surface temperature fronts in the Taiwan Strait
Authors: Chang Yi , Shimada Teruhisa , Lee Ming‐An , Lu Hsueh‐Jung , Sakaida Futoki , Kawamura Hiroshi
Published: December 2006

We present wintertime variations and distributions of sea surface temperature (SST) fronts in the Taiwan Strait by applying an entropy‐based edge detection method to 10‐year (1996–2005) satellite SST images with grid size of 0.01°. From climatological monthly mean maps of SST gradient magnitude in winter, we identify four significant SST fronts in the Taiwan Strait. The Mainland China Coastal Front is a long frontal band along the 50‐m isobath near the Chinese coast. The sharp Peng‐Chang Front appears along the Peng‐Hu Channel and extends northward around the Chang‐Yuen Ridge. The Taiwan Bank Front evolves in early winter. As the winter progresses, the front becomes broad and moves toward the Chinese coast, connecting to the Mainland China Coastal Front. The Kuroshio Front extends northeastward from the northeastern tip of Taiwan with a semicircle‐shape curving along the 100‐m isobath.
Pinusolide and 15‐methoxypinusolidic acid attenuate the neurotoxic effect of staurosporine in primary cultures of rat cortical cells
Authors: Koo K A , Lee M K , Kim S H , Jeong E J , Kim S Y , Oh T H , Kim Y C
Published: December 2006

Background and purpose:

Apoptosis is a fundamental process required for neuronal development but also occurs in most of the common neurodegenerative disorders. In an attempt to obtain an anti‐apoptotic neuroprotective compound from natural products, we isolated the diterpenoids, pinusolide and 15‐MPA, from B. orientalis and investigated their neuroprotective activity against staurosporine (STS) ‐induced neuronal apoptosis. In addition, we determined the anti‐apoptotic mechanism of these compounds in rat cortical cells.

Experimental approach:

Primary cultures of rat cortical cells injured by STS were used as an in vitro assay system. Cells were pretreated with pinusolide or 15‐MPA before exposure to STS. Anti‐apoptotic activities were evaluated by the measurement of cytoplasmic condensation and nuclear fragmentation. The levels of cellular peroxide, malondialdehyde (MDA) and [Ca2+]i, as well as the activities of superoxide dismutase (SOD) and caspase‐3/7, were measured.

Key results:

Pinusolide and 15‐MPA, at a concentration of 5.0 ìM, reduced the condensed nuclei and rise in [Ca2+]i that accompanies apoptosis induced by 100 nM STS. Pinusolide and 15‐MPA also protected the cellular activity of SOD, an antioxidative enzyme reduced by STS insult. Furthermore, the overproduction of reactive oxygen species and lipid peroxidation induced by STS was significantly reduced in pinusolide and 15‐MPA treated cells. In addition, pinusolide and 15‐MPA inhibited STS‐induced caspase‐3/7 activation.

Conclusions and Implications:

These results show that pinusolide and 15‐MPA protect neuronal cells from STS‐induced apoptosis, probably by preventing the increase in [Ca2+]i and cellular oxidation caused by STS, and indicate that they could be used to treat neurodegenerative diseases.

British Journal of Pharmacology (2007) 150, 65–71. doi:10.1038/sj.bjp.0706944
Modeling carbon nanostructures with the self-consistent charge density-functional tight-binding method: Vibrational spectra and electronic structure of C28, C60, and C70
Authors: Witek Henryk A. , Irle Stephan , Zheng Guishan , de Jong Wibe A. , Morokuma Keiji
Published: December 2006

The self-consistent charge density-functional tight-binding (SCC-DFTB) method is employed for studying various molecular properties of small fullerenes: C28, C60, and C70. The computed bond distances, vibrational infrared and Raman spectra, vibrational densities of states, and electronic densities of states are compared with experiment (where available) and density-functional theory (DFT) calculations using various basis sets. The presented DFT benchmark calculations using the correlation-consistent polarized valence triple zeta basis set are at present the most extensive calculations on harmonic frequencies of these species. Possible limitations of the SCC-DFTB method for the prediction of molecular vibrational and optical properties are discussed. The presented results suggest that SCC-DFTB is a computationally feasible and reliable method for predicting vibrational and electronic properties of such carbon nanostructures comparable in accuracy with small to medium size basis set DFT calculations at the computational cost of standard semiempirical methods.
Kinetics of the photostructural changes in a-Se films
Authors: Reznik A. , Lui B. J. M. , Rowlands J. A. , Baranovskii S. D. , Rubel O. , Lyubin V. , Klebanov M. , Kasap S. O. , Ohkawa Y. , Matsubara T. , Miyakawa K. , Kubota M. , Tanioka K. , Kawai T.
Published: December 2006

The kinetics of the photodarkening effect has been studied experimentally for amorphous selenium (a-Se) layers at room temperature and at an elevated temperature (35°C) close to the glass transition. By switching an intense pumping light on and off with a period of 100s, we have studied the kinetics of both the buildup of photodarkening and its relaxation (recovery). It was found that at 35°C, only a reversible component of photodarkening has been observed. This result has been interpreted within the framework of a phenomenological model assuming that photodarkening is caused by light-induced transitions of structural units from their ground states into metastable states. Our estimate for the energy barrier EB between these states obtained for the photodarkening process (EB∼0.8eV) coincides with that obtained from the analysis of the relaxation process. At room temperature, an irreversible component of photodarkening has been observed along with the reversible one. The energy barrier responsible for the relaxation of the reversible component at room temperature appears the same as at 35°C. This suggests that the energy barrier identified represents a fundamental feature of the photoinduced structural metastability in amorphous selenium.
Stabilization of the fan instability: Electron flux relaxation
Authors: Krafft C. , Volokitin A.
Published: December 2006

This paper presents some relevant simulation results on the interaction between electrostatic waves and suprathermal electron fluxes at anomalous cyclotron and Landau resonances. In particular, the case of a dense and continuous wave spectrum is studied. It is shown that, after the waves excited by the fan instability at anomalous cyclotron resonances have reached a first saturation stage due to particle trapping, the process of “dynamical resonance merging” takes place, which leads to a strong amplification of the waves’ amplitudes. The Landau resonances do not play an essential role in the total energy exchange between the particles and the waves, as they mainly help to smooth the peaks rising during the evolution of the electron parallel velocity distribution and contribute to damping. Moreover, the paper shows that at the asymptotic stage of the interaction, when the waves’ amplitudes are saturated and the electron flux is relaxed, some physical features clearly do not fit the predictions of the well-known quasilinear theory. The careful examination of a huge number of trajectories of particles moving in the effective field of the wave packet allows to state that most of the particles involved in the resonant interactions are trapped by several waves simultaneously. In this so-called “multitrapping” process, the particles perform complex oscillatory motions which are far from what is expected from the quasilinear theory, where the diffusive behavior of the particles in the velocity space results from small successive random steps.
Enhancement of the activation energy due to coupling effects in CdxZn1−xTe∕ZnTe double quantum dots
Authors: Kim T. W. , Lee H. S. , Park H. L.
Published: December 2006

Temperature-dependent photoluminescence measurements show that the activation energy of Cd0.6Zn0.4Te∕ZnTe double quantum dots (QDs) increases with decreasing ZnTe separation layer. At a separation-layer thickness of 6nm, this behavior can be attributed to enhancement in the tunneling probability of carriers from the smaller Cd0.6Zn0.4Te 1.5-monolayer (ML) QDs to the larger 3.0-ML QDs due to the coupling effect between the upper and the lower Cd0.6Zn0.4Te QDs. The present results indicate that the activation energy in Cd0.6Zn0.4Te∕ZnTe double QDs is significantly affected by the ZnTe separation layer.
Surface acoustic wave two-dimensional transport and location of microdroplets using echo signal
Authors: Renaudin Alan , Tabourier Pierre , Camart Jean-Christophe , Druon Christian
Published: December 2006

Digitalized microfluidics is dealing with microdroplet actuation and location. We propose the implementation of a surface acoustic wave (SAW) echo method so as to move and to locate a microdroplet from a single interdigital transducer (IDT). A prototype working at 20MHz demonstrates the ability of this method to achieve the goal with submillimeter accuracy quite sufficient for aimed biologic applications. The tested platform fitted with one IDT built on a LiNbO3 substrate allows the tracking of water droplets actuated by SAW running free or squeezed under a cover for biological treatments in a lab on chip.
Plasma manipulation techniques for positron storage in a multicell trap
Authors: Danielson J. R. , Weber T. R. , Surko C. M.
Published: December 2006

New plasma manipulation techniques are described that are central to the development of a multicell Penning trap designed to increase positron storage by orders of magnitude (e.g., to particle numbers N⩾1012). The experiments are done using test electron plasmas. A technique is described to move plasmas across the confining magnetic field and to deposit them at specific radial and azimuthal positions. Techniques to fill and operate two in-line plasma cells simultaneously, and the use of 1kV confinement potentials are demonstrated. These experiments establish the capabilities to create, confine, and manipulate plasmas with the parameters required for a multicell trap; namely, particle numbers >1010 in a single cell with plasma temperature ⩽0.2eV for plasma lengths ∼10cm and radii ⩽0.2cm. The updated design of a multicell positron trap for 1012 particles is described.
Bounds on the attractor dimension for low-Rm wall-bound magnetohydrodynamic turbulence
Authors: Pothérat Alban , Alboussière Thierry
Published: December 2006

Steady low-Rm magnetohydrodynamic (MHD) turbulence is investigated here through estimates of upper bounds for attractor dimension. A flow between two parallel walls with an imposed perpendicular magnetic field is considered. The flow is defined by its maximum velocity and the intensity of the magnetic field. Given the corresponding Reynolds and Hartmann numbers, one can rigorously derive an upper bound for the dimension of the attractor and find out which modes must be chosen to achieve this bound. The properties of these modes yield quantities that we compare to known heuristic estimates for the size of the smallest turbulent vortices and the degree of anisotropy of the turbulence. Our upper bound derivation is based on known bounds of the nonlinear inertial term, while low-Rm Lorentz forces—being linear—can be relatively easily dealt with. The simple configuration considered in this paper allows us to identify some boundaries separating different sets of modes in the space of nondimensional parameters, which are reminiscent of three important previously identified transitions observed in the real flow. The first boundary separates classical hydrodynamic sets of modes from MHD sets where anisotropy takes the form of a “Joule cone.” In the second, one can define the boundary separating three-dimensional (3D) MHD sets from quasi-two-dimensional (2D) MHD sets, when all “Orr-Sommerfeld modes” disappear and only “Squire modes” are left. The third separates sets where all the modes exhibit the same boundary layer thickness or so, and sets where many different “boundary layer modes” coexists in the set. The nondimensional relations defining these boundaries are then compared to the heuristics known for the transition between isotropic and anisotropic MHD turbulence, 3D and quasi-2D MHD turbulence, and that between a turbulent and a laminar Hartmann layer. In addition to this 3D approach, we also determine upper bounds for the dimension of forced turbulent flows modeled using a 2D MHD equation, which should become physically relevant in the quasi-2D MHD regime. The advantage of this 2D approach is that, while upper bounds are quite loose in three dimensions, optimal upper bounds exist for the 2D nonlinear term. This allows us to derive realistic attractor dimensions for quasi-2D MHD flows.
Sacrificial Al0.8Ga0.2As etching for microstructures in integrated optoelectronic devices
Authors: Guan Baolu , Guo Xia , Liang Ting , Gu Xiaoling , Deng Jun , Guo Jing , Yang Hao , Lin Qiaoming , Shen Guangdi
Published: December 2006

The lateral wet-etching kinetics of an Al0.8Ga0.2As sacrificial layer, a typical configuration for optoelectronic devices, has been investigated in detail. Expanding the one-dimensional Si and AlAs oxidation modes to the Al0.8Ga0.2As sacrificial layer etching process, compact analytical formulas were obtained for the time evolution of the etch front and for the etch rate. Through both experiment and theoretical calculations, the lateral etching process parameters, A, B, and B∕A, have been obtained for the different temperatures and etchant volume ratios. The etch rate is found to remain almost constant for a large range of etch length. However, when the etch temperature increases, a rapid increase in this rate is predicted. Activation energies for the process parameters, EA∼0.1eV and EB∼0.5eV, have also been obtained for the etchant volume ratio of 3:1 and the sacrificial layer thickness is 800nm.
Photoemission study of tris(8-hydroxyquinoline) aluminum/aluminum oxide/tris(8-hydroxyquinoline) aluminum interface
Authors: Ding Huanjun , Zorba Serkan , Gao Yongli , Ma Liping , Yang Yang
Published: December 2006

The evolution of the interface electronic structure of a sandwich structure involving aluminum oxide and tris(8-hydroxyquinoline) aluminum (Alq), i.e., (Alq∕AlOx∕Alq), has been investigated with photoemission spectroscopy. Strong chemical reactions have been observed due to aluminum deposition onto the Alq substrate. The subsequent oxygen exposure releases some of the Alq molecules from the interaction with aluminum. Finally, the deposition of the top Alq layer leads to an asymmetry in the electronic energy level alignment with respect to the AlOx interlayer.
Surface phase transitions in one-dimensional channels arranged in a triangular cross-sectional structure: Theory and Monte Carlo simulations
Authors: Pasinetti P. M. , Romá F. , Riccardo J. L. , Ramirez-Pastor A. J.
Published: December 2006

Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas of interacting monomers adsorbed on one-dimensional channels arranged in a triangular cross-sectional structure. Two kinds of lateral interaction energies have been considered: (1) wL, interaction energy between nearest-neighbor particles adsorbed along a single channel and (2) wT, interaction energy between particles adsorbed across nearest-neighbor channels. We focus on the case of repulsive transverse interactions (wT>0), where a rich variety of structural orderings are observed in the adlayer, depending on the value of the parameters kBT∕wT (being kB the Boltzmann constant) and wL∕wT. For wL∕wT=0, successive planes are uncorrelated, the system is equivalent to the triangular lattice, and the well-known (3×3) [(3×3)*] ordered phase is found at low temperatures and a coverage, θ, of 1∕3 [2∕3]. In the more general case (wL∕wT≠0), a competition between interactions along a single channel and a transverse coupling between sites in neighboring channels leads to a three-dimensional adsorbed layer. Consequently, the (3×3) and (3×3)* structures “propagate” along the channels and new ordered phases appear in the adlayer. Each ordered phase is separated from the disordered state by a continuous order-disorder phase transition occurring at a critical temperature, Tc, which presents an interesting dependence with wL∕wT. The Monte Carlo technique was combined with the recently reported free energy minimization criterion approach (FEMCA) [F. Romá et al., Phys. Rev. B 68, 205407 (2003)] to predict the critical temperatures of the order-disorder transformation. The excellent qualitative agreement between simulated data and FEMCA results allows us to interpret the physical meaning of the mechanisms underlying the observed transitions.
Coherent spin oscillations in bulk GaAs at room temperature
Authors: Hohage P. E. , Bacher G. , Reuter D. , Wieck A. D.
Published: December 2006

Time-resolved Kerr rotation in Voigt geometry is used to study the coherent evolution of spin states in moderately doped n-GaAs crystals with picosecond excitation. Due to the small spectral width of the exciting laser pulses, selective excitation of different electronic states is feasible, which allows one to extract both the dependence of the g factor and the spin dephasing time on energy. The authors are able to observe coherent spin oscillations in bulk n-GaAs at room temperature and deduce a g factor of g=−0.316±0.004 at 300K and a magnetic field dependent room temperature spin dephasing time of, e.g., T2*=110ps at B=1.2T.
Nonlinear properties of thin ferroelectric film-based capacitors at elevated microwave power
Authors: Soldatenkov Oleg , Samoilova Tatyana , Ivanov Andrey , Kozyrev Andrey , Ginley David , Kaydanova Tatyana
Published: December 2006

A key interest in high power high frequency microwave devices is their performance at high power levels. The authors discuss two mechanisms determining the capacitance variations of a thin ferroelectric film-based nonlinear capacitor under elevated microwave power levels analytically and experimentally studied over wide frequency range. The mechanisms are the dielectric nonlinearity under the microwave electric field and ferroelectric film heating due to microwave energy dissipation. It is shown that for thin ferroelectric film parallel plate capacitive structures up to millimeter-wave frequency range, the electric field effect is the dominant mechanism in the capacitance variations, and for limitations on power handling.