bluuebunny/crossref_metadata_2025 huggingface dataset:
New mutation of the Na channel in the severe form of potassium‐aggravated myotonia
Authors: Kubota Tomoya , Kinoshita Masanobu , Sasaki Ryogen , Aoike Futoshi , Takahashi Masanori P. , Sakoda Saburo , Hirose Kazuhiko
Published: April 2009

Myotonia manifests in several hereditary diseases, including hyperkalemic periodic paralysis (HyperPP), paramyotonia congenita (PMC), and potassium‐aggravated myotonia (PAM). These are allelic disorders originating from missense mutations in the gene that codes the skeletal muscle sodium channel, Nav1.4. Moreover, a severe form of PAM has been designated as myotonia permanens. A new mutation of Nav1.4, Q1633E, was identified in a Japanese family presenting with the PAM phenotype. The proband suffered from cyanotic attacks during infancy. The mutated amino acid residue is located on the EF‐hand calcium‐binding motif in the intracellular C‐terminus. A functional analysis of the mutant channel using the voltage‐clamp method revealed disruption of fast inactivation, a slower rate of current decay, and a depolarized shift in the voltage dependence of availability. This study has identified a new mutation of PAM with a severe phenotype and emphasizes the importance of the C‐terminus for fast inactivation of the sodium channel. Muscle Nerve 39: 666–673, 2009
A novel and simple method for genotyping the mdx mouse using high‐resolution melt polymerase chain reaction
Authors: Trebbin Andrea L. , Hoey Andrew J.
Published: April 2009

The mdx mouse mutation arises from a C‐to‐T point mutation, which terminates the translation of dystrophin and results in the loss of a functional dystrophin protein. mdx mice are used widely in studies of the role of dystrophin and of potential treatments for Duchenne muscular dystrophy, thus accurate genotyping is essential. Current methods require labor‐intensive efforts and can often lead to misconstrued results. This study describes a simple and highly reliable, sensitive, and user‐friendly, high‐resolution melt (HRM) assay that is able to utilize DNA obtained from a variety of sources in order to genotype the known sequence variant of the mdx mouse. Muscle Nerve 39: 603–608, 2009
Age‐related fatigue resistance in the knee extensor muscles is specific to contraction mode
Authors: Callahan Damien M. , Foulis Stephen A. , Kent‐Braun Jane A.
Published: April 2009

The question of whether skeletal muscle fatigue is preserved or enhanced in older adults is a point of controversy. Disparate findings may be attributed to differences in subject population and study protocols, including contraction mode. The purpose of this study was to test the hypotheses that healthy older (65–80 years of age, 8 males and 8 females) adults who were matched to young adults (21–35 years of age; 8 males and 8 females) with similar physical activity levels would: (1) fatigue less during isometric knee extensor (KE) contractions, but (2) would show similar fatigue during dynamic KE contractions performed at 120° s−1. Fatigue was induced with 4 minutes of intermittent, isometric, or dynamic maximal voluntary contractions, performed on separate days. Electrically stimulated contractions were used to evaluate central activation during both fatigue protocols. Older subjects maintained a higher percentage of baseline maximum voluntary contraction (MVC) torque than young subjects during isometric contractions (mean ± SE: 71 ± 3% and 57 ± 3%, respectively, P < 0.01). In contrast, there was no difference between age groups in torque maintenance during dynamic contractions (43 ± 3% and 44 ± 3%, respectively, P = 0.86). For both groups, changes in electrically stimulated and voluntary contractions followed similar trends, suggesting that central activation did not play a role in the age‐related differences in fatigue. Fatigue during the isometric protocol was associated with fatigue during the dynamic protocol in the young group only (r = 0.62, P = 0.01), suggesting that distinct mechanisms influence fatigue during isometric and dynamic contractions in older adults. Muscle Nerve 39: 692–702, 2009
Measurement of platelet‐derived microparticle levels using an enzyme‐linked immunosorbent assay in polymyositis and dermatomyositis patients
Authors: Shirafuji Toshihiko , Hamaguchi Hirotoshi , Higuchi Masatsugu , Kanda Fumio
Published: April 2009

Platelet‐derived microparticle (PDMP) levels were measured using an enzyme‐linked immunosorbent assay (ELISA) to elucidate the role of platelet activation in patients with polymyositis or dermatomyositis (PM/DM). PDMP levels in active PM/DM patients (median 13.3 U/ml, interquartile range 9.9–20.7 U/ml, n = 16) and those in patients undergoing treatment (12.1 U/ml, 7.4–16.7 U/ml, n = 12) were significantly higher than in controls (6.5 U/ml, 5.0–8.4 U/ml, n = 26, vs. active, P = 0.0001; vs. treatment, P = 0.004). In a paired sampling study, PDMP decreased significantly after glucocorticoid treatment (P = 0.04). PDMP in the active PM/DM patients correlated significantly with serum C‐reactive protein levels (rs = 0.67, P = 0.01). These results suggest that platelets may play an important role in the inflammatory process, and that PDMP level could be a useful marker of inflammatory activity in PM/DM patients. Muscle Nerve 39: 586–590, 2009
Evidence for intermuscle difference in postactivation potentiation in the human triceps surae: A mechanomyographic study
Authors: Miyamoto Naokazu , Fukunaga Tetsuo , Kawakami Yasuo
Published: April 2009

This study compared the postactivation potentiation of the medial gastrocnemius (MG) and soleus muscles by using mechanomyography (MMG). Twitch responses were evoked by stimulating the posterior tibial nerve with supramaximal intensity before and after a 10‐s maximal voluntary plantar flexion, and potentiation of each muscle was evaluated by peak‐to‐peak amplitude of the MMG signal. The MG showed greater potentiation than the soleus, reflecting the reported fiber type composition of these muscles. This result points to the possibility that one can delineate contrasting responses of synergist muscles to postactivation potentiation by this method. Muscle Nerve 39: 703–706, 2009
Interface‐tailored and nanoengineered polymeric materials for (opto)electronic devices
Authors: Ma Hong , Liu Michelle S , Jen Alex K‐Y
Published: April 2009

For plastic (opto)electronic devices such as light‐emitting diodes (LEDs), photovoltaic (PV) cells and field‐effect transistors (FETs), the processes of charge (hole/electron) injection, charge transport, charge recombination (exciton formation), charge separation (exciton diffusion and dissociation) and charge collection are critical to enhance their performance. Most of these processes are relevant to nanoscale and interfacial phenomena. In this review, we highlight the state‐of‐the‐art developments of interface‐tailored and nanoengineered polymeric materials to optimize the performance of (opto)electronic devices. These include (1) interfacial engineering of anode and cathode for polymer LEDs; (2) nanoengineered (C60 and inorganic semiconductor nanoparticles) π‐conjugated polymeric materials for PV cells; and (3) polymer and monolayer dielectrics/interfaces for FETs and light‐emitting and nano‐FETs. Copyright © 2009 Society of Chemical Industry
Plasma Process. Polym. 4/2009
Authors: Stöhr Uwe , Dohse Antje , Hoppe Paul , Thomas Michael , Kadel Klaus , Klages Claus‐Peter , Reinecke Holger
Published: April 2009

Cover: Using a newly developed plasma stamp, flat surfaces can be plasma‐coated and activated selectively at atmospheric pressure. The cover shows the scheme of the stamp and two stamps in action, illustrating that nearly every treatment area shape is possible. Further details can be found in the article by U. Stöhr,* A. Dohse, P. Hoppe, M. Thomas, K. Kadel, C.‐P. Klages, and H. Reinecke on page 228.
Quantum rotor description of the bosonic superfluid–Mott insulator transition in optical lattices
Authors: Polak T. P. , Kopéc T. K.
Published: April 2009

The physics of the Bose–Hubbard (BH) model is the subject of intensive studies in recent years, since it has been realized that BH Hamiltonian can be applied to systems of cold atoms confined in periodic optical lattice potential, where the effects on interactions are strongly enhanced. Our aim is to extend the widely used mean‐field treatment of the superfluid–Mott insulator (SF–MI) transition in the BH model. Our method also improves the strong‐coupling expansion that works well only for sufficiently large insulating gap. The key point of the approach is to consider the representation of strongly interacting bosons as particles with attached U(1) gauge group flux tubes, which constitutes the quantum rotor description. The effective action formalism allows us to cast the problem in terms of the phaseonly action and obtain an analytical formulas for critical lines. Finally, we calculate the zero‐temperature SF–MI phase diagrams for three‐dimensional BH model and compare our results with the outcome of numerical Monte Carlo simulations. We found a very good agreement for the quantitative results regarding the details of the lobe in the phase diagrams showing the quantum transition from superfluid to the Mott insulating phase (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entanglement of flux qubits through a joint detection of photons
Authors: Kurpas Marcin , Zipper Elżbieta
Published: April 2009

We study the entanglement creation between two flux qubits interacting with electromagnetic field modes. No direct interaction between the qubits exists. Entanglement is reached using the entanglement swapping method by an interference measurement performed on photons. We discuss the influence of off‐resonance and multi‐photon initial states on the qubit–qubit entanglement. The presented scheme is able to drive an initially separable state of two qubits into an highly entangled state suitable for quantum information processing (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multielectron irreducible representations of the magnetic translation group
Authors: Wal Andrzej
Published: April 2009

The symmetry of a 2D Bloch electron in the magnetic field is described by the magnetic translation groups (MTG). Their irreducible representations (IR), parameterized by numbers k1, k2 and s = 1, classify the states of an electron. This classification is performed by using the symmetry adapted bases, i.e. the bases of irreducible representations generated with the help of projection operator technique.

The multielectron system will be described by appropriate tensor products of these “one electron” IRs. From the other hand the same description should be obtained by consideration of irreducible representations of MTG with the parameter s identified as the number of electrons in the Landau level. These methods of classification of states are discussed for finite dimensional planar rectangular lattices (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On quantum entanglement and quantum communication
Authors: Żukowski Marek
Published: April 2009

This article presents a talk given at 23rd International Conference on Theoretical Physics (Ustroń, 2008). A new version of Bell's theorem is presented, with inequalities based on four assumptions: realism, locality and “free will” and “principle of rotational symmetry of physical laws”. The new Bell‐type inequalities are derived using a simple geometrical intuition. The assumptions behind Bell's theorem are discussed. A critique of overinterpretations of violations of Bell inequalities is given. Further on, a new criterion for entanglement is presented, based on simple geometrical ideas. This leads to a new class of entanglement identifiers, which is richer than entanglement witnesses. Finally a link between Bell's theorem and communication complexity problems will be shown. It covers also realizations, which do not involve entanglement (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum entanglement of space domains occupied by interacting electrons
Authors: Ramsak A. , Mravlje J. , Rejec T.
Published: April 2009

Spin‐entanglement of two electrons occupying two spatial regions – domains – is expressed in a compact form in terms of spin‐spin correlation functions. The power of the formalism is demonstrated on several examples ranging fromgeneration of entanglement by scattering of two electrons to the entanglement of a pair of qubits represented by a double quantum dot coupled to leads. In the latter case the collapse of entanglement due to the Kondo effect is analyzed (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generating experimental designs involving control and noise variables using genetic algorithms
Authors: Rodriguez Myrta , Montgomery Douglas C. , Borror Connie M.
Published: April 2009

Efficient estimation of response variables in a process is an important problem that requires experimental designs appropriated for each specific situation. When we have a system involving control and noise variables, we are often interested in the simultaneous optimization of the prediction variance of the mean (PVM) and the prediction variance of the slope (PVS). The goal of this simultaneous optimization is to construct designs that will result in the efficient estimation of important parameters. We construct new computer‐generated designs using a desirability function by transforming PVM and PVS into one desirability value that can be optimized using a genetic algorithm. Fraction of design space (FDS) plots are used to evaluate the new designs and six cases are discussed to illustrate the procedure. Copyright © 2009 John Wiley & Sons, Ltd.
HyBAR: hybrid bone‐attached robot for joint arthroplasty
Authors: Song S. , Mor A. , Jaramaz B.
Published: April 2009

Background

A number of small bone‐attached surgical robots have been introduced to overcome some disadvantages of large stand‐alone surgical robots. In orthopaedics, increasing demand on minimally invasive joint replacement surgery has also been encouraging small surgical robot developments. Among various technical aspects of such an approach, optimal miniaturization that maintains structural strength for high speed bone removal was investigated.

Methods

By observing advantages and disadvantages from serial and parallel robot structures, a new hybrid kinematic configuration was designed for a bone‐attached robot to perform precision bone removal for cutting the femoral implant cavity during patellofemoral joint arthroplasty surgery. A series of experimental tests were conducted in order to evaluate the performance of the new robot, especially with respect to accuracy of bone preparation.

Results

A miniaturized and rigidly‐structured robot prototype was developed for minimally invasive bone‐attached robotic surgery. A new minimally invasive modular clamping system was also introduced to enhance the robotic procedure. Foam and pig bone experimental results demonstrated a successful implementation of the new robot that eliminated a number of major design problems of a previous prototype.

Conclusions

For small bone‐attached surgical robots that utilize high speed orthopaedic tools, structural rigidity and clamping mechanism are major design issues. The new kinematic configuration using hinged prismatic joints enabled an effective miniaturization with good structural rigidity. Although minor problems still exist at the prototype stage, the new development would be a significant step towards the practical use of such a robot. Copyright © 2009 John Wiley & Sons, Ltd.
MicroRNA 92b Controls the G1/S Checkpoint Gene p57 in Human Embryonic Stem Cells
Authors: Sengupta Srikumar , Nie Jeff , Wagner Ryan J. , Yang Chuhu , Stewart Ron , Thomson James A.
Published: April 2009

Human embryonic stem (ES) cells exhibit a shorter G1 cell cycle phase than most somatic cells. Here, we examine the role of an abundant, human ES cell-enriched microRNA, miR-92b, in cell cycle distribution. Inhibition of miR-92b in human ES cells results in a greater number of cells in the G1 phase and a lower number in the S phase. Conversely, overexpression of miR-92b in differentiated cells results in a decreased number of cells in G1 phase and an increased number in S-phase. p57, a gene whose product inhibits G1 to S-phase progression, is one of the predicted targets of miR-92b. Inhibition of miR-92b in human ES cells increases p57 protein levels, and miR-92b overexpression in differentiated cells decreases p57 protein levels. Furthermore, miR-92b inhibits a luciferase reporter construct that includes part of the 3′ untranslated region of the p57 gene containing the predicted target of the miR-92b seed sequence. Thus, we show that the miRNA miR-92b directly downregulates protein levels of the G1/S checkpoint gene p57.

Disclosure of potential conflicts of interest is found at the end of this article.
Upregulation of RAGE at the blood‐brain barrier in streptozotocin‐induced diabetic mice
Authors: Liu Li Ping , Hong Hao , Liao Jian Ming , Wang Tong Sheng , Wu Jing , Chen Si Si , Li Yong Qi , Long Yan , Xia Yuan Zheng
Published: April 2009

Deposition of amyloid‐β peptide (Aβ) in the brain of diabetes is poorly understood. The receptor for advanced glycation end products (RAGE) at the blood‐brain barrier (BBB) is critical for regulation of Aβ homeostasis in the brain. In this studies, we used streptozotocin‐induced diabetic mice to observe the expression of RAGE at the BBB by Western blot and immunocytochemical analysis, and the in vivo blood‐to‐brain influx transport of 125I‐Aβ1–40 using the permeability surface area product (PS) and brain capillary uptake. In the diabetic mice with hyperglycemia (>16.0 mmol/L) at 6 weeks, RAGE expression at the BBB was significantly upregulated, no significant changes of RAGE levels were found at 1 and 3 weeks after diabetes induction. The data of PS and brain capillary uptake for Aβ showed significant RAGE‐dependent transport of Aβ across the BBB and substantial RAGE‐dependent brain capillary uptake at 6 weeks after diabetes induction. We conclude that the upregulation of RAGE at the BBB contributes to cerebral Aβ deposition in the diabetes. Synapse 63:636–642, 2009. © 2009 Wiley‐Liss, Inc.
Phenotypic characterization of mice heterozygous for a null mutation of glutamate carboxypeptidase II
Authors: Han Liqun , Picker Jonathan D. , Schaevitz Laura R. , Tsai Guochuan , Feng Jiamin , Jiang Zhichun , Chu Hillary C. , Basu Alo C. , Berger‐Sweeney Joanne , Coyle Joseph T.
Published: April 2009

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. Disturbed glutamate signaling resulting in hypofunction of N‐methyl‐D‐aspartate receptors (NMDAR) has been implicated in the pathophysiology of schizophrenia. Glutamate Carboxypeptidase II (GCP II) hydrolyzes N‐acetyl‐alpha L‐aspartyl‐L‐glutamate (NAAG) into glutamate and N‐acetyl‐aspartate. NAAG is a neuropeptide that is an NMDAR antagonist as well as an agonist for the metabotropic glutamate receptor‐3 (mGluR3), which inhibits glutamate release. The aggregate effect of NAAG is thus to attenuate NMDAR activation. To manipulate the expression of GCP II, LoxP sites were inserted flanking exons 1 and 2, which were excised by crossing with a Cre‐expressing mouse. The mice heterozygous for this deletion showed a 50% reduction in the expression level of protein and functional activity of GCP II in brain samples. Heterozygous mutant crosses did not yield any homozygous null animals at birth or as embryos (N > 200 live births and fetuses). These data are consistent with the previous report that GCP II homozygous mutant mice generated by removing exons 9 and 10 of GCP II gene were embryonically lethal and confirm our hypothesis that GCP II plays an essential role early in embryonic development. Heterozygous mice, however, developed normally to adulthood and exhibited increased locomotor activity, reduced social interaction, and a subtle cognitive deficit in working memory. Synapse 63:625–635, 2009. © 2009 Wiley‐Liss, Inc.
Sex Differences in the Effects of Neighborhood Socioeconomic Disadvantage and Social Organization on Rural Adolescents' Aggression Trajectories
Authors: Karriker-Jaffe Katherine J. , Foshee Vangie A. , Ennett Susan T. , Suchindran Chirayath
Published: April 2009

We determined whether effects of neighborhood socioeconomic disadvantage on trajectories of aggression were moderated or mediated by neighborhood social organization and examined sex differences in neighborhood effects for rural adolescents. We used five waves of survey data collected over 2.5 years linked with neighborhood data from interviews with parents and the US Census. The sample (N= 5,118) was 50.1% female, 52.0% white and 38.3% African–American; average age at baseline was 13.1 years. Multilevel growth curve models for both girls and boys showed no significant interactions between neighborhood socioeconomic disadvantage and indicators of social organization. Neither sample showed evidence of mediated effects. In main effects models, neighborhood disadvantage was associated with the average aggression trajectory for girls. For boys, the effects of neighborhood socioeconomic disadvantage and social disorganization appeared to be confounded with each other. Neighborhood disadvantage is detrimental for rural girls regardless of the level of social organization.
Fracture of the Medial Tubercle of the Posterior Process of the Talus: Magnetic Resonance Imaging Appearance with Clinical Follow-Up
Authors: O'Loughlin Padhraig , Sofka Carolyn M. , Kennedy John G.
Published: April 2009

Fractures of the medial tubercle of the posterior process of the talus are rare injuries. They are often misdiagnosed, resulting in increased morbidity and symptoms of chronic ankle pain and instability. When undetected, these fractures may become displaced, with potential additional injuries such as to the flexor hallucis longus tendon which may become interposed between the fracture fragments. We report a case of a clinically unsuspected fracture of the medial tubercle of the posterior process of the talus seen on magnetic resonance imaging, treated conservatively, with interval satisfactory healing of the fracture at 6 weeks follow-up.
The coiled coil‐helix‐coiled coil‐helix proteins may be redox proteins
Authors: Banci Lucia , Bertini Ivano , Ciofi-Baffoni Simone , Tokatlidis Kostas
Published: April 2009

A number of nuclear encoded proteins are imported in to the intermembrane space of mitochondria where they adopt a coiled coil‐helix‐coiled coil‐helix (CHCH) fold. Two disulfide bonds formed by twin CX3C or CX9C motifs stabilize this fold. Some of these proteins are also characterized at their N‐termini by the presence of two additional cysteine residues which can perform oxidoreductase or metallochaperone functions or both. This fold represents the most ‘minimal’ oxidoreductase domain described so far.
Current trends in high throughput proteomics in cyanobacteria
Authors: Ow Saw Yen , Wright Phillip C.
Published: April 2009

Advancements in genome sequencing and high throughput proteomics of cyanobacterial strains led to 13 published reports, from a small number of laboratories. These successful studies focused on Synechocystis, Nostoc and Anabaena strains, prochlorococcus, and halotolerant Euhalothece. The implications of emerging quantitative aspects developed and applied in these large‐scale studies are assessed in the wake of advanced cyanobacterial research. Furthermore, contributions from traditional and early high throughput analysis of cyanobacterial proteomics are compared and summarised. Finally, opinions are provided to link both the trends and the future challenges. This review aims to push the synergy between proteomics and cyanobacterial research to improve both the technical and biological significance.
The three domains of the mitochondrial outer membrane protein Mim1 have discrete functions in assembly of the TOM complex
Authors: Lueder Franziska , Lithgow Trevor
Published: April 2009

The assembly of mitochondrial outer membrane proteins is an essential process, mediated by the SAM complex and a set of additional protein modules. We show that one of these, Mim1, is anchored in the outer membrane with its N‐terminus exposed to the cytosol and its C‐terminus in the mitochondrial intermembrane space. Using an in vitro assay to measure the multi‐step pathway for assembly of Tom40 into the TOM complex, we find that an “early reaction” mediated by the SAM complex is regulated by the N‐terminal domain of Mim1. In addition, a “late reaction” catalysed by the Sam37 subunit of the SAM complex is also influenced by Mim1. Thus, Mim1 participates at multiple stages in the assembly of the TOM complex.
Full sequencing of TP53 identifies identical mutations within in situ and invasive components in breast cancer suggesting clonal evolution
Authors: Zhou Wenjing , Muggerud Aslaug A. , Vu Phuong , Due Eldri U. , Sørlie Therese , Børresen-Dale Anne-Lise , Wärnberg Fredrik , Langerød Anita
Published: April 2009

In breast cancer, previous studies have suggested that somatic TP53 mutations are likely to be an early event. However, there are controversies regarding the cellular origin and linear course of breast cancer. The purpose of this study was to investigate tumor evolution in breast cancer by analyzing TP53 mutation status in tumors from various stages of the disease. The entire coding sequence of TP53 was sequenced in a cohort of pure ductal carcinoma in situ (DCIS), pure invasive cancer (≤15mm) and mixed lesions (i.e. invasive cancer with an in situ component). Of 118 tumor samples, 19 were found to harbor a TP53 mutation; 5 (15.6%) of the pure DCIS, 4 (10.5%) of the pure invasive cancers and 10 (20.8%) of the mixed lesions. In the mixed lesions, both the invasive and the DCIS components showed the same mutation in all 5 cases where the two components were successfully microdissected. Presence of the same mutation in both DCIS and invasive components from the same tumor indicates same cellular origin. The role of mutant TP53 in the progression of breast cancer is less clear and may vary between subtypes.
Geometrical method to determine the reciprocal screws and applications to parallel manipulators
Authors: Zhao Jianguo , Li Bing , Yang Xiaojun , Yu Hongjian
Published: April 2009

Screw theory has demonstrated its wide applications in robot kinematics and statics. We aim to propose an intuitive geometrical approach to obtain the reciprocal screws for a given screw system. Compared with the traditional Plücker coordinate method, the new approach is free from algebraic manipulation and can be used to obtain the reciprocal screws just by inspecting the structure of manipulator. The approach is based on three observations that describe the geometrical relation for zero pitch screw and infinite pitch screw. Based on the observations, the reciprocal screw systems of several common kinematic elements are analyzed, including usual kinematic pairs and chains. We also demonstrate usefulness of the geometrical approach by a variety of applications in mobility analysis, Jacobian formulation, and singularity analysis for parallel manipulator. This new approach can facilitate the parallel manipulator design process and provide sufficient insights for existing manipulators.
Was/werevariation: A perspective from London
Authors: Cheshire Jenny , Fox Sue
Published: April 2009

This article presents a systematic analysis of morphosyntactic variation in London English, investigatingwas/werevariation in the speech of adolescents and elderly speakers in a multicultural inner London area and a less diverse outer London area. In outer London, dialect leveling to a mixedwas/weren'tsystem is well underway, as in many other areas of the U.K. Negativeweren'tis frequent and a grammaticalized invariantweren't ittag is developing. In inner London, variation in adolescent speech is strongly influenced by ethnicity, resulting in a lower overall frequency ofwasleveling and, in negative contexts, a mixed pattern of leveling to bothwasn'tandweren't. The patterns of variation of Anglo “heritage” inner London adolescents differ both from elderly speakers in the same area and from their peers in outer London. Our analysis confirms the need for socially realistic models of language change that take account of the social diversity of large multicultural urban cities.
The varying influence of social and linguistic factors on language stability and change: The case of Eskilstuna
Authors: Sundgren Eva
Published: April 2009

Continuity and Change in Present-Day Swedish: Eskilstuna Revisited is a large-scale study of language change in real time. In this article, the focus is on the results of a trend study and the analysis of how extralinguistic and linguistic factors influence how language varies and changes.

The empirical material consists of informal conversationlike interviews, in which seven morphological and morphophonological variables have been analyzed in terms of the traditional extralinguistic factors of social group, gender, and age, as well as in terms of social networks. These morpho(phono)logical variables are sociolinguistically marked and have been hypothesized to show a process of more or less rapid change from regional dialect toward spoken standard. The rate of change at the level of the community has been slow, however. Comparisons between the influence of extralinguistic and linguistic factors indicate that social forces are more influential than linguistic ones.
The Postcolonial Paradox: Becoming Less than Whole(s) Producing Parts that Exclude Other Parts
Authors: Duggan Joseph F.
Published: April 2009

The purpose of this article is to address coexistent Anglican faith identities that have flourished in contexts after the colonial period. Thus far these identities have been treated as differences in viewpoints. Metaphysically speaking member differences are included as ‘parts’ of the one ‘whole’ Body of Christ. Without a postcolonial metaphysical and theological critique that decolonizes the Body of Christ, as the Church, then parts repeatedly seek, to redefine, restore or reform the ‘whole’ to maintain the whole’s coherence and empowering the former part. Ignoring the metaphysical aspect of ecclesial identity postpones the emergence of a postcolonial Anglican Communion where multiple faith identities can coexist.
Erfassung der Lebensqualität von Vorschulkindern mit dem Kiddy-KINDLR
Authors: Harstick-Koll Sylvia , Kuschel Annett , Bertram Heike , Naumann Sebastian , Hahlweg Kurt , Hautmann Christopher , Döpfner Manfred
Published: April 2009

Zusammenfassung. Die Erfassung der kindlichen Lebensqualität in epidemiologischen Studien und als Erfolgskriterium von Behandlungsmaßnahmen gewinnt zunehmend an Bedeutung. Für Vorschulkinder steht mit dem Kiddy-KINDLR das einzige deutschsprachige Instrument zur Verfügung, das die subjektive Lebensqualität in dieser Altersgruppe krankheitsübergreifend erfasst. Nach einem kurzen Überblick über deutschsprachige krankheitsübergreifende Instrumente zur Erfassung der kindlichen Lebensqualität wird der Kiddy-KINDLR psychometrisch und bezüglich der Eignung im Vorschulalter geprüft. Es werden verschiedene Determinanten kindlicher Lebensqualität hinsichtlich ihres Einflusses untersucht. Im Rahmen zweier Studien zur universellen und indizierten Prävention psychischer Auffälligkeiten bei Kindergartenkindern wurde der Kiddy-KINDLR bei N = 414 Kindern eingesetzt. Die internen Konsistenzen liegen je nach Alter und Geschlecht zwischen .66 und .70. Es finden sich Zusammenhänge zwischen kindlicher Lebensqualität und verschiedenen Einschätzungen der Mütter bezüglich Erziehungsverhalten, Lebenszufriedenheit, Partnerschaftsqualität und kindlichen Verhaltensauffälligkeiten. Mit dem Kiddy-KINDLR lassen sich Gruppenunterschiede hinsichtlich soziodemographischer Variablen abbilden und das Instrument unterscheidet zwischen einer universellen und indizierten Stichprobe. Die Eignung des Instruments für die Anwendung in der Forschung und Praxis scheint gegeben, Einschränkungen werden diskutiert.
Grazing effects on belowground C and N stocks along a network of cattle exclosures in temperate and subtropical grasslands of South America
Authors: Piñeiro Gervasio , Paruelo José M. , Jobbágy Esteban G. , Jackson Robert B. , Oesterheld Martin
Published: April 2009

We evaluated the effects of grazing on C and N belowground pools by comparing 15 grazing‐exclosure pairs across the Río de la Plata grasslands of Uruguay and Argentina. We measured C and N pools of belowground biomass, particulate organic matter (POM), and the mineral associated organic matter (MAOM) in the top meter of the soil. Grazing exclusion in the Río de la Plata grasslands promoted (1) decreased belowground biomass stocks across all sites, (2) increased soil organic carbon (SOC) and soil organic nitrogen (SON) stocks in upland soils, and (3) decreased stocks in shallow and lowland soils. In all cases, SOC and SON variations were largely derived by changes in MAOM stocks that maintained their C:N ratios unchanged. In contrast, stocks of the labile POM fractions changed little, but C:N ratios of these fractions decreased after grazing removal. We hypothesize that changes in soil organic matter (SOM) contents between grazed and ungrazed stands result from the balance between changes in belowground N allocation patterns (root N retention hypothesis) and the ability of the soil to retain the extra N available after the exclusion of herbivores and the cessation of volatilization and leaching from urine and dung patches (N loss hypothesis). On the basis of our results we suggest that the relative importance of these two cooccurring mechanisms will shape grazing effects on SOM stocks, depending on soil properties, including texture, pH and soil depth, and vegetation type, particularly allocation patterns and C:N ratios of different plant species.
Irradiance in polluted cumulus fields: Measured and modeled cloud‐aerosol effects
Authors: Schmidt K. S. , Feingold G. , Pilewskie P. , Jiang H. , Coddington O. , Wendisch M.
Published: April 2009

We present a new strategy to validate modeled spectral irradiance of shallow cumulus cloud fields in a polluted background with airborne measurements. The concept is based on a spectral distinction of effects associated with heterogeneous clouds, aerosol particles, and surface albedo. We use measurements from the Gulf of Mexico Atmospheric Composition and Climate Study, conducted in the urban‐industrial Houston area. Modeled irradiance fields were obtained from extensive three‐dimensional radiative transfer calculations applied to the output of large eddy simulations. We show that the measurements below clouds or cloud gaps can only be reproduced by the calculations when including the aerosol radiative effects. The technique enables the derivation of measurement‐based spectral forcing and absorption of the cloud‐aerosol system which will help substantiate model calculations. At 400 nm wavelength, the inclusion of aerosol increases forcing of the cloud‐aerosol system by 8%, and absorption by 20%.
Magnetic properties of micrometeorites
Authors: Suavet C. , Gattacceca J. , Rochette P. , Perchiazzi N. , Folco L. , Duprat J. , Harvey R. P.
Published: April 2009

Most micrometeorites are strongly magnetic: the signal of a single micrometeorite may exceed the signal of a weakly magnetized standard sediment sample. Micrometeorites contain abundant magnetite, mostly produced by high‐temperature oxidation during atmospheric entry. In this study, we carried out measurements on 520 micrometeorites (505 melted cosmic spherules, 6 partially melted scoriaceous micrometeorites, and 9 unmelted micrometeorites). The natural remanent magnetization and the saturation isothermal remanent magnetization have been measured, followed by alternating field or thermal stepwise demagnetization. The natural remanent magnetization is in the range of 0.4–300 A/m for cosmic spherules; it is a stable thermal remanent magnetization acquired by quenching in the Earth's magnetic field. The range is 3.8–16 A/m for scoriaceous micrometeorites and 78–525 A/m for unmelted micrometeorites, which may have preserved a preatmospheric magnetization. The magnetic susceptibility is in the range of 0.005–2.9 SI for cosmic spherules and is in the range of 0.06–0.12 SI for scoriaceous and unmelted micrometeorites. Temperature‐dependent susceptibility analyses and thermal demagnetization indicate that magnetite is cation substituted in cosmic spherules. Different populations of magnetite grains may have different degrees of cation substitution within a single micrometeorite. Anisotropy of magnetic susceptibility measurements indicates that micrometeorites are strongly anisotropic (anisotropy degree >15%) and that most have oblate fabrics consistent with the parallel habit of magnetite in barred olivine cosmic spherules.
Role of adsorption and swelling on the dynamics of gas injection in coal
Authors: Pini R. , Ottiger S. , Burlini L. , Storti G. , Mazzotti M.
Published: April 2009

An experimental technique is presented to perform gas injection experiments on coal cores confined by an external hydrostatic pressure, which makes use of the so‐called transient step method. The experiments are intended to improve the knowledge on the different mechanisms acting during CO2 storage in coal seams, in particular, those related to permeability. Helium, nitrogen, and carbon dioxide have been injected at pressure ranging from 10 to 80 bars and at confining pressures varying between 60 and 140 bars. The experiments with helium have been used to study the mechanical compliance of the coal core, whereas those with the adsorbing N2 and CO2 to study the effects of adsorption and swelling on the flow dynamics. The obtained experimental transient steps were successfully described using a mathematical model, consisting of mass balances accounting for gas flow and adsorption, and mechanical constitutive equations for the description of porosity and permeability changes during injection. A semiempirical relationship between permeability and operating pressures is validated, and the corresponding parameters have been evaluated. Results showed increase in permeability with decreasing effective pressure on the sample and, when an adsorbing gas was injected, a reduction in permeability caused by swelling, with CO2 having a stronger effect compared to N2.
ARGONAUTE 1 homeostasis invokes the coordinate action of the microRNA and siRNA pathways
Authors: Mallory Allison C , Vaucheret Hervé
Published: April 2009

ARGONAUTE 1 (AGO1) slices endogenous messenger RNAs (mRNAs) during both microRNA (miRNA)‐ and short interfering RNA (siRNA)‐guided post‐transcriptional silencing. We have previously reported that AGO1 homeostasis is maintained through the repressive action of miR168 on AGO1 mRNA and the stabilizing effect of AGO1 protein on miR168, but siRNA‐mediated AGO1 regulation has not been reported. Here, we show that AGO1‐derived siRNAs trigger RNA DEPENDENT RNA POLYMERASE 6 (RDR6)‐, SUPPRESSOR OF GENE SILENCING 3 (SGS3)‐ and SILENCING DEFECTIVE 5 (SDE5)‐dependent AGO1 silencing, which also requires DICER‐LIKE 2 (DCL2) and DCL4. By varying the efficacy of miR168‐guided AGO1 mRNA cleavage, we show that siRNA‐mediated AGO1 silencing depends on correct miRNA targeting, pointing to coordinated regulatory actions of the miRNA and siRNA pathways during the maintenance of AGO1 homeostasis. Finally, our results reveal that dcl2, dcl3 and dcl4 mutations similarly affect post‐transcriptional gene silencing (PTGS) mediated by a sense transgene and PTGS mediated by inverted repeats, validating the branched pathway model proposed previously.
Hysteresis loop collapse for linear response in magnetic-tunnel-junction sensors
Authors: Pong Philip W. T. , Schrag B. , Shapiro A. J. , McMichael R. D. , Egelhoff W. F.
Published: April 2009

In our Al2O3 magnetic-tunnel junction (MTJ) samples that have a Neel coupling equal to or larger than their easy-axis coercivities, we found that the hysteresis loop totally collapses into a near-linear response upon rotating the easy axis of the sample off the applied field axis. A very high magnetic field sensitivity of 138%/mT (13.8%/Oe), which is among the highest reported so far, with near-linear response, was exhibited by Al2O3 MTJs using this loop collapsing technique. This phenomenon can be explained by the switching astroid curve. In order to make this technique applicable in an actual sensor, we devised a two-step procedure whereby both easy-axis and hard-axis fields are used to accomplish the same loop collapsing effect as rotation. These result is one of the best combinations of saturation field and tunneling magnetoresistance ever achieved for MTJs, in addition to the linear nonhysteretic response at zero field that is so important for magnetic sensors.
One- and two-photon absorption of highly conjugated multiporphyrin systems in the two-photon Soret transition region
Authors: Fisher Jonathan A. N. , Susumu Kimihiro , Therien Michael J. , Yodh Arjun G.
Published: April 2009

This study presents a detailed investigation of near-infrared one- and two-photon absorption (TPA) in a series of highly conjugated (porphinato)zinc(II) compounds. The chromophores interrogated include meso-to-meso ethyne-bridged (porphinato)zinc(II) oligomers (PZnn species), (porphinato)zinc(II)-spacer-(porphinato)zinc(II) (PZn-Sp-PZn) complexes, PZnn structures featuring terminal electron-releasing and -withdrawing substituents, related conjugated arrays in which electron-rich and -poor PZn units alternate, and benchmark PZn monomers. Broadband TPA cross-section measurements were performed ratiometrically using fluorescein as a reference. Superficially, the measurements indicate very large TPA cross-sections (up to ∼104GM; 1GM=1×10−50cm4sphoton−1) in the two-photon Soret (or B-band) resonance region. However, a more careful analysis of fluorescence as a function of incident photon flux suggests that significant one-photon absorption is present in the same spectral region for all compounds in the series. TPA cross-sections are extracted for the first time for some of these compounds using a model that includes both one-photon absorption and TPA contributions. Resultant TPA cross-sections are ∼10GM. The findings suggest that large TPA cross-sections reported in the Soret resonance region of similar compounds might contain significant contributions from one-photon absorption processes.
Femtosecond micromachining of internal voids in high explosive crystals for studies of hot spot initiation
Authors: McGrane S. D. , Grieco A. , Ramos K. J. , Hooks D. E. , Moore D. S.
Published: April 2009

Femtosecond micromachining was used to produce controlled patterns of internal voids in high explosive single crystals of 1,3-dinitrato-2,2-bis(nitratomethyl) propane (PETN), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The micromachined voids were characterized with optical microscopy and confocal Raman microscopy. Optical microscopy established that the voids generated near the threshold energy were localized to submicrometer diameters. Increasing the micromachining energy above threshold led to microcracking along preferred crystalline planes. Consolidation of hundreds to thousands of individual voids allowed creation of defined two- and three-dimensional structures. Production of three-dimensional consolidated structures led to extended crystal damage or residual strain over tens to hundreds of micrometers. Confocal Raman microscopy established that the defects generated were voids, with no chemical products observable and with diminished crystal spectral intensity. The results of this work suggest that large controlled arrays of internal voids can be produced in explosive crystals, with the exception that continuous three-dimensional defect structures are possible only if the extended damage is acceptable. These methods and materials are expected to be valuable for controlled studies of hot spot initiation in shocked explosives.
Structural and magnetic properties of magnetron sputtered Co70Fe30 films on GaAs(110)
Authors: Hindmarch A. T. , Suszka A. K. , MacKenzie M. , Chapman J. N. , Henini M. , Taylor D. , Hickey B. J. , Marrows C. H.
Published: April 2009

The surface morphology, crystal structure, and in-plane magnetic anisotropy of sputter deposited Co70Fe30 films on GaAs(110) epilayer substrates have been investigated. The surface morphology of thin Co70Fe30 films appears to closely follow that of the underlying GaAs(110) substrate. The study of the crystal structure by x-ray diffraction shows that no crystallographic orientation other than Co70Fe30(110) is present in our films, although we cannot unambiguously deconvolute characteristic reflections of Co70Fe30(110) from those of GaAs(110) due to the very small lattice mismatch. High-resolution transmission electron microscopy shows that the crystal structure of the Co70Fe30 film is coherently matched to the GaAs(110) substrate. The magnetic anisotropies in both 35 and 1100 Å thick films are consistent with those of similar epitaxial films, and demonstrate that a strong bcc (110) texture is propagated throughout the entire film thickness. The cubic and uniaxial anisotropy constants extracted by fitting with the Stoner–Wohlfarth model are consistent with those of molecular beam epitaxy grown bcc CoxFe(100−x)/GaAs(110). This work shows that sputter deposition may be used to produce structurally coherent bcc-Co70Fe30/GaAs(110) contacts suitable for spin-injection applications.
High frequency and noise model of gate-all-around metal-oxide-semiconductor field-effect transistors
Authors: Nae B. , Lazaro A. , Iniguez B.
Published: April 2009

The surrounding gate (SGT) metal-oxide-semiconductor field-effect transistor is one of the most promising candidates for the downscaling of complementary metal-oxide-semiconductor technology toward the sub-50-nm channel length range since the SGT architecture allows excellent control of the channel charge in the silicon film, thus reducing short channel effects. However, at these dimensions, quantum effects must be considered in order to develop accurate compact models useful for circuit simulations. In this paper we study the influence of quantum effects on dc, radio frequency (rf), and microwave noise for nanoscale SGT transistors including nonstationary effects. We present an analytical charge model for adjusting the charge control computed from the self-consistent solution of the two-dimensional Schrödinger and Poisson equations. rf and noise performances are calculated using the active transmission line method. We compared, on the one hand, classical and quantum charge control models and, on the other, drift-diffusion and hydrodynamic transport models.
Highly phosphorus-doped crystalline Si layers grown by pulse-magnetron sputter deposition
Authors: Fenske Frank , Gorka Benjamin
Published: April 2009

The electrical properties of highly phosphorus-doped crystalline silicon films deposited by pulse-magnetron sputtering were studied. The films were grown, 450 nm thick, on Si(100) and Si(111) wafers at low substrate temperatures Ts of 450–550 °C and post-treated by rapid thermal annealing (RTA) and plasma hydrogenation (PH). In the case of films grown on Si(100), at all values of Ts postgrowth treatment by RTA resulted in an increase in the dopant activation up to 100% and of the Hall mobility to about bulklike values of 50 cm2 V−1 s−1. This result suggests high structural quality of the films on Si(100). The Si(111) films, which are typically more defective, exhibit a completely different behavior with a strong dependence of the electrical dopant activation and the Hall mobility on Ts. By post-treatment a maximum P donor activation level of 22% could be obtained. The variation in the post-treatment procedure (RTA+PH and PH+RTA) for the films deposited at high Ts showed that PH results only in minor changes in the film properties. The different influence of RTA and PH is discussed in terms of the different defect structure of the films. These investigations reveal that high Ts and after-treatment by RTA are the main preconditions for optimal electrical film properties.