bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of dietary level of methionine on growth performance and immune response in Japanese quails (Coturnix coturnix japonica)
Authors: Parvin Rana , Mandal Asit B , Singh Satyendra M , Thakur Rakesh
Published: December 2009

BACKGROUND: Methionine (Met) being the first limiting amino acid in maize/soybean‐based quail diets, its supplementation provides scope for improvement of protein quality and reduction of dietary protein concentration. The question remains to what extent it can be incorporated in the diet of genetically improved quails. Therefore the effect of dietary Met level was assessed on growth performance and immune response in growing Japanese quails (n = 400) divided equally into 20 groups. Five dietary treatments (∼230 g kg−1 crude protein and 12.14 MJ kg−1 metabolisable energy) were formulated with 3.5, 4.5, 5.0, 5.5 and 6.0 g kg−1 Met respectively, and each was offered to four groups of birds from 0 to 35 days of age.

RESULTS: Live weight at day 35 increased (P < 0.0001) up to 5.0 g kg−1 dietary Met level but did not improve further at higher Met levels (5.5 and 6.0 g kg−1). Improved (P < 0.039) feed conversion ratio was achieved at 5.5 g kg−1 Met level, which was statistically similar to that at 5.0 g kg−1 Met level during 0–14 days of age. Cellular (phytohaemagglutinin from Phaseolus vulgaris) immune response increased (P < 0.0001) with increasing dietary Met concentration, whereas humoral (sheep red blood cells) immune response did not differ.

CONCLUSION: The optimal requirement of Met was 5.0 g kg−1 for growth and 5.5 g kg−1 for maximum cellular immune response. Copyright © 2009 Society of Chemical Industry
Characterization of human papillomavirus type 11‐specific immune responses in a preclinical model
Authors: Peng Shiwen , Best Simon R. , Hung Chien‐Fu , Loyo Myriam , Lyford‐Pike Sofia , Flint Paul W. , Tunkel David E. , Saunders John R. , Wu T. C. , Pai Sara I.
Published: December 2009

Objectives/Hypothesis:

Human papillomavirus (HPV) types 6 and 11 are associated with recurrent respiratory papillomatosis (RRP). Although a prophylactic vaccine has been developed that protects against HPV infection, a therapeutic vaccine is still needed for those patients infected with and/or suffering from persistent disease. Therefore, we developed a novel, therapeutic DNA vaccine targeting HPV‐11 and characterized the in vivo immunologic responses generated against HPV‐11 E6 and E7 after DNA vaccination in a preclinical model.

Methods:

We generated a DNA vaccine that encodes the HPV‐11 E6 and E7 genes in a pcDNA3 backbone plasmid. We then vaccinated C57BL/6 mice with the pcDNA3‐HPV11‐E6E7 DNA plasmid. Splenocytes were harvested from these vaccinated animals and were incubated with overlapping peptides spanning either the HPV‐11 E6 or E7 protein. The frequency of interferon‐γ–releasing CD8+ T cell responses was then analyzed by flow cytometry.

Results:

Vaccinated mice with the HPV11‐E6E7 DNA generated strong CD8+ T cell responses against the E6aa44‐51 peptide. We determined that the epitope is presented by the MHC class I H2‐Kb molecule. No significant E7 peptide‐specific T cell responses were observed.

Conclusions:

We developed a novel DNA vaccine that targets the E6 gene of HPV‐11. Characterization of the immunologic responses elicited by this DNA vaccine reveals that the E6aa44‐51 peptide contains the most immunogenic region for the HPV‐11 viral type. Knowledge of this specific T cell epitope and generation of a RRP preclinical model will allow for the development and evaluation of novel vaccine strategies targeting the RRP patient population. Laryngoscope, 2010
Learning mode: Adapting and innovating is crucial for teams
Authors: Lindoerfer Dennis
Published: December 2009

Teams in the modern organizational world are awash in change and confronted by continually shifting opportunities and threats. Those that do not learn and adapt are bound to fail. There are four general practices teams can engage in to ensure they are learning as they work: establishing a climate for learning, continually assessing team members' work together, working with a team coach, and managing knowledge effectively. The team leader plays a central role in all of these efforts.
Transcriptome analysis in benefit–risk assessment of micronutrients and bioactive food components
Authors: Keijer Jaap , van Helden Yvonne G. J. , Bunschoten Annelies , van Schothorst Evert M.
Published: December 2009

The establishment of functional effects due to variation in concentrations of micronutrients in our diet is difficult since they are often not immediately recognized as being healthy or unhealthy. Indeed, effects induced by micronutrients are hard to identify and therefore the establishment of the recommended daily intake, the optimal intake and the upper limit pose a challenge. For bioactive food components this is even more complicated. Whole‐genome transcriptome analysis is highly suitable to obtain unbiased information on potential affected biological processes on a whole‐genome level. Here, we will describe and discuss several aspects of transcriptome analysis in benefit–risk assessment, including effect size, sensitivity and statistical power, that have to be taken into account to faithfully identify functional effects of micronutrients and bioactive food components.
Theoretical and experimental evaluation of continuous arterial spin labeling techniques
Authors: Pohmann Rolf , Budde Juliane , Auerbach Edward J. , Adriany Gregor , Uğurbil Kâmil
Published: December 2009

Continuous arterial spin labeling is known to be the most sensitive arterial spin labeling technique. To avoid magnetization transfer effects and to overcome hardware limitations, several sequences have been proposed that adiabatically label the inflowing blood. Four of these methods are examined with respect to their sensitivity both theoretically by Bloch equation simulations and experimentally. All sequences were optimized carefully by adjusting their measurement parameters based exclusively on the results of simulations. Perfusion measurements on the human brain obtained at 3 T result in excellent images from all techniques, while differences in sensitivity are similar to those expected from the simulations. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.
Hybrid ultrasound MRI for improved cardiac imaging and real‐time respiration control
Authors: Feinberg David A. , Giese Daniel , Bongers D. Andre , Ramanna Sudhir , Zaitsev Maxim , Markl Michael , Günther Matthias
Published: December 2009

A hybridized dual‐imaging system combining real‐time ultrasound imaging and MRI was utilized for cardiac imaging at 1.5 T and 3 T. The ultrasound scanner with a programmable software interface was connected via computer to the MRI scanner. Electronic noise was eliminated with electromagnetic shielding and grounding to the screen room. At 3 T, real‐time prospective motion compensation in dynamic cine cardiac imaging was implemented using B‐mode ultrasound imaging. The ultrasound technique avoided drawbacks such as signal saturation or steady‐state interruption of the MR navigator gating. At 1.5 T, a low‐latency real‐time feedback to balanced steady state free precision MR imaging was performed in three normal volunteers. Results showed active tracking of the heart during respiratory motion and improvement in time‐averaged cardiovascular images. Future studies can fully exploit the potential of the high‐frequency position information provided by the ultrasound system for more advanced applications in real‐time organ tracking. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.
Investigating afferent nerve activity from the lower urinary tract: Highlighting some basic research techniques and clinical evaluation methods
Authors: Wyndaele Jean Jacques
Published: December 2009

Aims

To give a review of some basic research recording and clinical evaluations of bladder afferent nerves and the sensory information related to them.

Methods

Literature survey.

Results

Direct investigation of the afferent nerve pathways of the lower urinary tract (LUT) can be done in animal studies where potentials can be recorded and measured directly in the dorsal roots after laminectomy. Differentiation between A delta and C fibers is possible when conduction speed is determined. In humans afferent innervation can be studied clinically with determination of the sensation on sensation‐related bladder diary, during cystometrical bladder filling, with local electrical stimulation. All need further study. Electrodiagnostic tests are further explored.

Conclusions

Both basic research and clinical evaluation of afferent nerves and sensory function in the LUT are possible. To find out how both relate to each other, and how this function can be evaluated, is the task to be done now. Neurourol. Urodynam. 29: 56–62, 2010. © 2009 Wiley‐Liss, Inc.
Incontinence in the frail elderly: Report from the 4th international consultation on incontinence
Authors: DuBeau Catherine E. , Kuchel George A. , Johnson II Theodore , Palmer Mary H. , Wagg Adrian
Published: December 2009

Aims

To summarize current knowledge on the etiology, assessment, and management of urinary incontinence (UI) in frail older persons. “Frail” here indicates a person with a clinical phenotype combining impaired physical activity, mobility, muscle strength, cognition, nutrition, and endurance, associated with being homebound or in care institutions and a high risk of intercurrent disease, disability, and death.

Methods

Revision of 3rd ICI report using systematic review covering years 2004–2008.

Results

We focus on the etiologic, management, and treatment implications of the key concept that UI in frail persons constitutes a syndromic model with multiple interacting risk factors, including age‐related physiologic changes, comorbidity, and the common pathways between them. We present new findings with evidence summaries based on all previous data, and an evidence‐based algorithm for evaluation and management of UI in frail elderly. We also present new evidence and summarize the data on etiology and management of nocturia and urinary retention in frail elderly.

Conclusions

Despite the overwhelming burden of UI among this population, there remains a continuing paucity of new clinical trials in frail elderly, limiting evidence for the effectiveness of the full range of UI therapy. Future research is needed on current UI treatments (especially models of care delivery, and pharmacologic and surgical therapies), novel management approaches, and the etiologic mechanisms and pathways of the syndromic model. Neurourol. Urodynam. 29: 165–178, 2010. © 2009 Wiley‐Liss, Inc.
Neurologic urinary incontinence
Authors: Wyndaele J.J. , Kovindha A. , Madersbacher H. , Radziszewski P. , Ruffion A. , Schurch B. , Castro D. , Igawa Y. , Sakakibara R. , Wein A.
Published: December 2009

Introduction

This manuscript summarizes the work of Committee 10 on neurologic bladder and bowel of the International Consultation on Incontinence in 2008–2009. As the data are very large the outcome is presented in different manuscripts. This manuscript deals with neurologic urinary incontinence.

Methods

Through in debt literature review all aspects of neurological urinary incontinence were studied for levels of evidence. Recommendations for diagnosis and treatment, and for future research were made.

Results

Pathophysiology was summarized for different levels of lesions. For epidemiology, specific diagnostics, conservative treatment and surgical treatment of neurologic urinary incontinence, levels of evidence and grades of recommendation were made following ICUD criteria.

Conclusions

Though data are available that advice and guide in the management of urinary incontinence in neurologic patients, not many data have a high level of evidence or permit a high grade of recommendation. More and well‐structured research is needed. Neurourol. Urodynam. 29: 159–164, 2010. © 2009 Wiley‐Liss, Inc.
Lung adenocarcinoma cells floating in lymphatic vessels resist anoikis by expressing phosphorylated Src
Authors: Sakuma Yuji , Takeuchi Tomoyo , Nakamura Yoshiyasu , Yoshihara Mitsuyo , Matsukuma Shoichi , Nakayama Haruhiko , Ohgane Naoki , Yokose Tomoyuki , Kameda Yoichi , Tsuchiya Eiju , Miyagi Yohei
Published: December 2009

The ability to resist anoikis is critical for carcinoma cells to metastasize. Although several lung adenocarcinoma cell lines were shown to repress anoikis through the activation of Src, it remains unknown whether Src actually plays a crucial role in anoikis resistance in lung adenocarcinoma tissues. We examined 20 human lung adenocarcinoma tissues with lymphatic permeation and nine cell lines to investigate whether intralymphatic floating carcinoma cells in the tissues, used as an in vivo model of anoikis resistance, actually suppressed anoikis and whether cell lines in suspension culture, an in vitro model of anoikis resistance, survived through Src activation. We observed that the intralymphatic carcinoma cells aggregated tightly to form nests expressing E‐cadherin and phosphorylated Src (p‐Src). The apoptotic indices of these cells were comparable to those of extracellular matrix adhesive cells in all tissues, indicating that the intralymphatic cells actually evaded anoikis. Next, we found that the nine cell lines in suspension aggregated loosely (five cell lines) or tightly (four cell lines), and all cells resisted anoikis. Upon detachment, four cell lines (LC‐KJ, HCC827, H1650, and H1975) formed compact spheroids that expressed E‐cadherin and p‐Src. The spheroids were similar to intralymphatic tumour nests and were thus considered to be a suitable model of the nests. The spheroids of the four cell lines underwent apoptosis after treatment with the Src/Abl/Kit inhibitor PP1 or Src/Abl inhibitor bosutinib. On the other hand, the Abl/Kit inhibitor imatinib did not affect cell growth or apoptosis in the four types of spheroids. These results indicate that Src, but not Abl or Kit, plays an essential role in the development of anoikis resistance in lung adenocarcinomas. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Synthesis of thermal‐stable and photo‐crosslinkable polyfluorenes for the applications of polymer light‐emitting diodes
Authors: Wang Pei‐Hsuan , Ho Ming‐Shou , Yang Sheng‐Hsiung , Chen Kuei‐Bai , Hsu Chain‐Shu
Published: December 2009

Three polyfluorene derivatives which have oxetane‐containing phenyl group at C‐9 position were synthesized via the palladium‐catalyzed Suzuki‐coupling reaction. The synthesized polymers PFB, PFG, and PFR emit blue, green, and red light, respectively. A double‐layer device with the configuration of ITO/PEDOT/polymer/Ca/Al using PFB as the active layer showed a threshold voltage of 5 V, a maximum brightness of 2030 cd/m2, and a maximum current efficiency of 0.35 cd/A. Using PFG as the active layer, the device exhibited a threshold voltage of 6 V, a maximum brightness of 6447 cd/m2, and a maximum current efficiency of 1.27 cd/A. Using PFR as the active layer, the device showed a threshold voltage of 4 V, a maximum brightness of 2135 cd/m2, and a maximum current efficiency of 0.16 cd/A. Better electroluminescent performance was also found based on different design of device structures. Due to photo‐crosslinking property of oxetane groups, the UV‐exposed thin films are insoluble in common organic solvents. A device comprised of blue, green, and red‐emissive pixels was successfully fabricated by spin‐coating and photo‐lithographic processes. In addition, a white light‐emitting device with CIE coordinate of (0.34, 0.33) was achieved by blending PFR into a host material PFB as the active layer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 516–524, 2010
From polymeric particles to multifunctional nanocapsules for biomedical applications using the miniemulsion process
Authors: Landfester Katharina , Musyanovych Anna , Mailänder Volker
Published: December 2009

The miniemulsions process represents a versatile tool for the formation of polymeric nanoparticles consisting of different kinds of polymer as obtained by a variety of polymerization types ranging from radical, anionic, cationic, enzymatic polymerization to polyaddition, and polycondensation. The process perfectly allows the encapsulation of hydrophilic and hydrophobic liquids and solids in polymeric shells, molecularly dissolved dyes or other components. In combination with a specific functionalization of the nanoparticles' or nanocapsules' surfaces and the possibility to release substances in a defined way from the interior, complex nanoparticles or nanocapsules are obtained, which are ideally suited for application in biomedical application as marker and targeted drug‐delivery system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 493–515, 2010
Nanostructure and mechanical properties studied during dynamical straining of microfibrillar reinforced HDPE/PA blends
Authors: Denchev Zlatan , Dencheva Nadya , Funari Sérgio S. , Motovilin Mladen , Schubert Tom , Stribeck Norbert
Published: December 2009

Oriented polymer blends whose major component is high‐density polyethylene (HDPE) are strained until failure. Two‐dimensional (2D) small‐angle X‐ray scattering (SAXS) patterns monitor the nanostructure evolution, which is related to the macroscopic mechanical evolution. Data evaluation methods for high‐precision determination of macroscopic and nanoscopic parameters are presented. The hardest materials exhibit a very inhomogeneous nanodomain structure. During straining, their domains appear to be wedged and inhibit transverse contraction on the nanometer scale. Further components of the blends are polyamide 6 (PA6) or polyamide 12 (PA12) (20–30%) and Yparex® 8102 (YP) as compatibilizer (0–10%). Some HDPE/PA6 blends are additionally loaded with commercial nanoclays (Nanomer® or Cloisite®), the respective amounts being 7.5% and 5% with respect to PA. Blending of HDPE with PA12 causes no synergistic effect. In the absence of nanoclay, PA6 and HDPE form a heterogeneous nanostructure with high macroscopic Young's modulus. After addition of YP a rather homogeneous scaffold structure is observed in which some of the PA6 microfibrils and HDPE crystallites appear to be rigidly connected, but the modulus has decreased. Both kinds of nanoclay induce a transition in the HDPE/PA6 blends from a structure without transverse correlation among the microfibrils into a macrolattice with 3D correlations among the HDPE domains from neighboring microfibrils. In the range of extensions between 0.7 and 3.5%, the scattering entities with 3D correlation show transverse elongation instead of transverse contraction. The process is interpreted as overcoming a correlation barrier executed by the crystallites in an evasion‐upon‐approaching mechanism. During continued straining, the 3D correlation is reduced or completely removed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 237–250, 2010
Melt crystallization and morphology of poly(ε‐caprolactone)‐poly(ethylene glycol) diblock copolymers with different compositions and molecular weights
Authors: Xu Ying , Zhang Yan , Fan Zhongyong , Li Suming
Published: December 2009

Ring opening polymerization of ε‐caprolactone was realized in the presence of monomethoxy poly(ethylene glycol) with Mn = 1000 and 2000, using Zn(La)2 as catalyst. The resulting PCL‐PEG diblock copolymers with CL/EO repeat unit molar ratios from 0.2 to 3.0 were characterized by using DSC, WAXD, SEC, and 1H NMR. The crystal phase of PCL blocks exist in all polymers, and the crystallization ability of PCL blocks increases with CL/EO ratio. PEG blocks are able to crystallize for copolymers with CL/EO below 1.0 only. Melt crystallization results were analyzed with Avrami equation. The Averami exponent n is around 3.0 in most cases, in agreement with heterogeneous nucleation with three dimensional growth. The morphology of the crystals was observed by using POM. Rod‐like crystals were found to grow in 1, 3 or 2, 4 quadrants for samples with low molecular weights. In the case of a copolymer with Mn,PEG = 2000 and Mn,PCL = 800, PEG blocks could crystallize and grow on PCL crystals after PCL finished to form rod‐like crystals, leading to formation of poorly or well structured spherulites. The spherulite growth rate (G) was determined at different crystallization temperatures (Tc) ranging from 9 to 49 °C. All the copolymers present a steady G decrease with increasing crystallization temperature due to lower undercooling. On the other hand, increase of CL/EO ratio leads to increase of G in the same Tc range. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 286–293, 2010
Passive infrared thermographic imaging for mobile robot object identification
Authors: Fehlman William L. , Hinders Mark K.
Published: December 2009

The usefulness of thermal infrared imaging as a mobile robot sensing modality is explored, and a set of thermal–physical features used to characterize passive thermal objects in outdoor environments is described. Objects that extend laterally beyond the thermal camera's field of view, such as brick walls, hedges, picket fences, and wood walls, as well as compact objects that are laterally within the thermal camera's field of view, such as metal poles and tree trunks, are considered. Classification of passive thermal objects is a subtle process because they are not a source for their own emission of thermal energy. A detailed analysis is included of the acquisition and preprocessing of thermal images, as well as the generation and selection of thermal–physical features from these objects within thermal images. Classification performance using these features is discussed, as a precursor to the design of a physics‐based model to automatically classify these objects. Published 2009 Wiley Periodicals, Inc.*

This article is a US Government work and, as such, is in the public domain of the United States of America.
Attractor networks
Authors: Rolls Edmund T.
Published: December 2009

An attractor network is a network of neurons with excitatory interconnections that can settle into a stable pattern of firing. This article shows how attractor networks in the cerebral cortex are important for long‐term memory, short‐term memory, attention, and decision making. The article then shows how the random firing of neurons can influence the stability of these networks by introducing stochastic noise, and how these effects are involved in probabilistic decision making, and implicated in some disorders of cortical function such as poor short‐term memory and attention, schizophrenia, and obsessive‐compulsive disorder. Copyright © 2009 John Wiley & Sons, Ltd.

This article is categorized under:

Computer Science > Neural Networks
Animal learning
Authors: Castro Leyre , Wasserman Edward A.
Published: December 2009

Pavlov and Thorndike pioneered the experimental study of animal learning and provided psychologists with powerful tools to unveil its underlying mechanisms. Today's research developments and theoretical analyses owe much to the pioneering work of these early investigators. Nevertheless, in the evolution of our knowledge about animal learning, some initial conceptions have been challenged and revised. We first review the original experimental procedures and findings of Pavlov and Thorndike. Next, we discuss critical research and consequent controversies which have greatly shaped animal learning theory. For example, although contiguity seemed to be the only condition that is necessary for learning, we now know that it is not sufficient; the conditioned stimulus (CS) also has to provide information about the occurrence of the unconditioned stimulus (US). Also, animals appear to learn different things about the same stimuli when circumstances vary. For instance, when faced with situations in which the meaning of a CS changes, as in the case of acquisition and later extinction, animals seem to preserve the original knowledge (CS‐US) in addition to learning about the new conditions (CS‐noUS). Finally, we discuss how parallels among Pavlovian conditioning, operant conditioning, and human causal judgment suggest that causal knowledge may lie at the root of both human and animal learning. All of these empirical findings and theoretical developments prove that animal learning is more complex and intricate than was once imagined. Copyright © 2009 John Wiley & Sons, Ltd.

This article is categorized under:

Cognitive Biology > Evolutionary Roots of Cognition

Psychology > Comparative Psychology
Dipeptide Tyr‐Leu (YL) exhibits anxiolytic‐like activity after oral administration via activating serotonin 5‐HT1A, dopamine D1and GABAAreceptors in mice
Authors: Kanegawa Norimasa , Suzuki Chihiro , Ohinata Kousaku
Published: December 2009

We found that Tyr‐Leu (YL) dose‐dependently exhibits potent anxiolytic‐like activity (0.1–1 mg/kg, i.p.) comparable to diazepam in the elevated plus‐maze test in mice. YL was orally active (0.3–3 mg/kg). A retro‐sequence peptide or a mixture of Tyr and Leu was inactive. The anxiolytic‐like activity of YL was inhibited by antagonists for serotonin 5‐HT1A, dopamine D1and GABAAreceptors; however, YL had no affinity for them. We also determined the order of their activation is 5‐HT1A, D1and GABAAreceptors using selective agonists and antagonists. Taken together, YL may exhibit anxiolytic‐like activity via activation of 5‐HT1A, D1and GABAAreceptors.
Curcumin inhibits hepatitis C virus replication via suppressing the Akt‐SREBP‐1 pathway
Authors: Kim KyeongJin , Kim Kook Hwan , Kim Hye Young , Cho Hyun Kook , Sakamoto Naoya , Cheong JaeHun
Published: December 2009

A polyphenolic compound from the curry spice turmeric, curcumin, is known to show anti‐viral activity against the influenza virus, adenovirus, coxsackievirus, and the human immunodeficiency virus. However, it remains to be determined whether curcumin can inhibit the replication of hepatitis C virus (HCV). In this study, we showed that curcumin decreases HCV gene expression via suppression of the Akt‐SREBP‐1 activation, not by NF‐κB pathway. The combination of curcumin and IFNα exerted profound inhibitory effects on HCV replication. Collectively, our results indicate that curcumin can suppress HCV replication in vitro and may be potentially useful as novel anti‐HCV reagents.
Dynamics of Alfvén waves in partially ionized astrophysical plasmas
Authors: SHAIKH DASTGEER
Published: December 2009

We develop a two dimensional, self-consistent, compressible fluid model to study evolution of Alfvenic modes in partially ionized astrophysical and space plasmas. The partially ionized plasma consists mainly of electrons, ions and significant neutral atoms. The nonlinear interactions amongst these species take place predominantly through direct collision or charge exchange processes. Our model uniquely describe the interaction processes between two distinctly evolving fluids. In our model, the electrons and ions are described by a single-fluid compressible magnetohydrodynamic (MHD) model and are coupled self-consistently to the neutral fluid via compressible hydrodynamic equations. Both plasma and neutral fluids are treated with different energy equations that adequately enable us to monitor non-adiabatic and thermal energy exchange processes between these two distinct fluids. Based on our self-consistent model, we find that the propagation speed of Alfvenic modes in space and astrophysical plasma is slowed down because these waves are damped predominantly due to direct collisions with the neutral atoms. Consequently, energy transfer takes place between plasma and neutral fluids. We describe the mode coupling processes that lead to the energy transfer between the plasma and neutral and corresponding spectral features.
The effects of task type in Synchronous Computer-Mediated Communication
Authors: Yilmaz Yucel , Granena Gisela
Published: December 2009

This study examines the potential of learner-learner interaction through Synchronous Computer-Mediated Communication (SCMC) to focus learners’ attention on form. Focus on form is operationalized through Language-Related Episodes (LREs), instances where learners turn their attention to formal aspects of language by questioning the accuracy of their own or each other’s language use. The study also compares two task types, jigsaw and dictogloss, with respect to the number and characteristics of LREs. Ten adult intermediate ESL learners from an intensive English language program in the US worked together in dyads to carry out one jigsaw and one dictogloss task in an SCMC environment. Tasks were controlled for content and were presented in two alternative orders. The dictogloss in this study generated more LREs than the jigsaw. LREs were also qualitatively different across task types. Jigsaw LREs were implicit and did not result in incorrectly solved outcomes, whereas dictogloss LREs were explicit and resulted in correctly solved, incorrectly solved, and unresolved outcomes.
EFL students’ vocabulary learning in NS-NNS e-mail interactions: Do they learn new words by imitation?
Authors: Sasaki Akihiko , Takeuchi Osamu
Published: December 2009

The present study investigated Japanese students’ EFL vocabulary development through e-mail interactions with a native English speaker (NS), with primary focus on students’ imitation of new words. According to sociocultural theory, learners can internalize new linguistic knowledge by imitating an expert’s expressions to create his/her own utterances. This study, therefore, specifically examined whether (1) students could imitate the new vocabulary items provided by the NS tutor, and (2) they could retain these items at the end of the project. An examination of the e-mail log showed that students did imitate and use some of the lexis provided by the NS. The results of the post-test also revealed that some of the imitated words were subsequently retained. However, there were some words that had been learned without imitation. The questionnaire survey and the students’ interview comments indicated that students memorized a considerable number of new words provided by the NS by repeatedly reading them in e-mail text, as well as in other learning contexts, such as regular classes and independent study, through noticing, retrieving, and generating the meaning/form of each word (Nation, 2001). The study concluded that vocabulary learning via e-mail takes place not only by a single process such as imitation, but also by a combination of various processes functioning in an integrated manner.
Tight Bounds for Blind Search on the Integers and the Reals
Authors: DIETZFELBINGER MARTIN , ROWE JONATHAN E. , WEGENER INGO , WOELFEL PHILIPP
Published: December 2009

We analyse a simple random process in which a token is moved in the interval A = {0, . . ., n}. Fix a probability distribution μ over D = {1, . . ., n}. Initially, the token is placed in a random position in A. In round t, a random step sized is chosen according to μ. If the token is in position x ≥ d, then it is moved to position x − d. Otherwise it stays put. Let TX be the number of rounds until the token reaches position 0. We show tight bounds for the expectation Eμ(TX) of TX for varying distributions μ. More precisely, we show that $\min_\mu\{\E_\mu(T_X)\}=\Theta\bigl((\log n)^2\bigr)$. The same bounds are proved for the analogous continuous process, where step sizes and token positions are real values in [0, n + 1), and one measures the time until the token has reached a point in [0, 1). For the proofs, a novel potential function argument is introduced. The research is motivated by the problem of approximating the minimum of a continuous function over [0, 1] with a ‘blind’ optimization strategy.
THE TRANSITIONAL DYNAMICS OF FISCAL POLICY IN SMALL OPEN ECONOMIES
Authors: Heijdra Ben J. , Ligthart Jenny E.
Published: December 2009

We study the dynamic macroeconomic effects of fiscal shocks under lump-sum tax financing. To this end, we develop an intertemporal macroeconomic model for a small open economy, featuring monopolistic competition in the intermediate goods market, endogenous (intertemporal) labor supply, and finitely lived households. Fiscal shocks are shown to yield endogenously determined (dampened) cycles for a realistic calibration of the model. Impulse response functions of fiscal policy shocks in the finite-horizon model differ substantially from those resulting from an infinitely lived representative agent model. This can be explained by the presence of Ethier-productivity effects, which increase the size of long-run output multipliers to a greater extent in the infinite-horizon model.
A Special Safeguard Mechanism for Agricultural Imports: what experience with other GATT/WTO safeguards tells us about what might work
Authors: FINGER J. MICHAEL
Published: December 2009

The success of existing GATT/WTO safeguard or flexibility provisions to sustain long-run liberalization stems from their procedural criteria (e.g., transparent and participatory decisions to impose new import restrictions) overcoming their suspect economic criteria (e.g., injury). The proposed SSM includes no procedural and minimal notification requirements. It would expand by arithmetic formulas the bounds within which a Member might unilaterally impose new import restrictions. Simulations indicate that the formulas provide a poor guide for policy – they would (a) allow an import restriction more often in situations when it is not beneficial than when it is, and (b) in situations in which an import restriction would help, they more often ban it than allow it. If procedural requirements are out – i.e., developing Members insist on a ‘usable’ safeguard – then the simple rule ‘bound rates may be exceeded for a maximum of [x] tariff lines at any one time’ is better economics than the proposed price and volume triggers. (No economic criteria are better than bad economic criteria.) Each Member would have the flexibility to change its lists of Special Products and Sensitive Products, there being a limit on the numbers of products on the lists at any one time.
ADHS im Erwachsenenalter
Authors: Petermann Franz
Published: December 2009

Die Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) im Erwachsenenalter gewinnt sowohl in der Forschung als auch in der klinischen Praxis immer mehr an Bedeutung. Auch wenn mittlerweile zahlreiche Studien die Bedeutung der ADHS als Lebensspannenerkrankung hervorheben, liegen bislang vergleichsweise wenige Studien vor, die sich explizit mit der Diagnostik und Therapie beschäftigen. Angesichts der hohen Prävalenz der adulten ADHS ist mehr Forschung jedoch dringend erforderlich. Nur so können diagnostische und therapeutische Strategien weiterentwickelt werden. Im vorliegenden Themenschwerpunkt werden die neuesten Befunde zur adulten ADHS vorgestellt und diskutiert.
Zur klinischen Aussagekraft des Screenings psychischer Störungen für Jugendliche (SPS-J)
Authors: Hampel Petra , Rosemann Anna , Schneider Andrea , Karpinski Norbert , Petermann Franz
Published: December 2009

Die deutschsprachige Version des Reynolds Adolescent Adjustment Screening Inventory (RAASI) von Reynolds (2001) , das Screening psychischer Störungen im Jugendalter (SPS-J), hat sich in ersten Studien als reliabel und valide erwiesen. In zwei Studien mit Jugendlichen der 6. bis 9. Klasse wurden erneut die Reliabilität und Validität ermittelt: Die Konstruktvalidität wurde an N = 496 Jugendlichen überprüft. Die kriterienbezogene Validität wurde an 52 Jugendlichen mit psychischen Störungen (internalisierende: n = 20, externalisierende: n = 18, kombinierte psychische Störungen: n = 14) untersucht. In beiden Studien konnten die zufriedenstellenden bis guten internen Konsistenzen sowie die faktorielle und korrelative Validität bestätigt werden. Mädchen wiesen generell eine höhere Ängstlichkeit/Depressivität auf. Jugendliche der 8./9. Klasse wiesen höhere psychische Auffälligkeiten auf als Jugendliche der 6./7. Klasse. Insbesondere die Mädchen der 8./9. Klasse erwiesen sich als Risikogruppe. Die klinischen Gruppen mit internalisierenden, externalisierenden und kombinierten psychischen Störungen unterschieden sich erwartungsgemäß von geschlechts-, alters- und klassenparallelisierten nicht-klinischen Gruppen. Demnach konnte die gute Reliabilität und Konstruktvalidität des SPS-J erneut bestätigt werden. Außerdem fanden sich weitere Hinweise für dessen kriterienbezogene Validität.
Terrestrial gamma ray flash production by lightning current pulses
Authors: Carlson B. E. , Lehtinen N. G. , Inan U. S.
Published: December 2009

Terrestrial gamma ray flashes (TGFs) are brief bursts of gamma rays observed by satellites, typically in coincidence with detectable lightning. We incorporate TGF observations and the key physics behind current TGF production theories with lightning physics to produce constraints on TGF production mechanisms. The combined constraints naturally suggest a mechanism for TGF production by current pulses in lightning leader channels. The mechanism involves local field enhancements due to charge redistribution in current pulses and draws seed energetic particles from cold runaway in breakdown processes. The mechanism can reproduce the observed TGF time scale including multipulse TGFs, is in agreement with existing production altitude estimates, and may help explain TGF spectra by naturally producing unbeamed emissions.
A case study of the radiative forcing of persistent contrails evolving into contrail‐induced cirrus
Authors: Haywood James M. , Allan Richard P. , Bornemann Jorge , Forster Piers M. , Francis Peter N. , Milton Sean , Rädel Gaby , Rap Alexandru , Shine Keith P. , Thorpe Robert
Published: December 2009

The radiative forcing due to a distinct pattern of persistent contrails that form into contrail‐induced cirrus near and over the UK is investigated in detail for a single case study during March 2009. The development of the contrail‐induced cirrus is tracked using a number of high‐resolution polar orbiting and lower‐resolution geostationary satellite instruments and is found to persist for a period of around 18 h, and at its peak, it covers over 50,000 km2. The shortwave (SW) and longwave (LW) radiative forcing of the contrail‐induced cirrus is estimated using a combination of geostationary satellite instruments, numerical weather prediction models, and surface observation sites. As expected, the net radiative effect is a relatively small residual of the much stronger but opposing SW and LW effects, locally totaling around 10 W m−2 during daylight hours and 30 W m−2 during nighttime. A simple estimate indicates that this single localized event may have generated a global‐mean radiative forcing of around 7% of recent estimates of the persistent contrail radiative forcing due to the entire global aircraft fleet on a diurnally averaged basis. A single aircraft operating in conditions favorable for persistent contrail formation appears to exert a contrail‐induced radiative forcing some 5000 times greater (in W m−2 km−1) than recent estimates of the average persistent contrail radiative forcing from the entire civil aviation fleet. This study emphasizes the need to establish whether similar events are common or highly unusual for a confident assessment of the total climate effect of aviation to be made.
Numerical evaluation of a set of analytical infiltration equations
Authors: Lassabatere L. , Angulo‐Jaramillo R. , Soria‐Ugalde J. M. , Šimůnek J. , Haverkamp R.
Published: December 2009

In this paper, a set of analytical infiltration equations that are commonly used to evaluate one‐ and three‐dimensional water infiltration from a surface disc source is studied. Both the quasi‐exact analytical formulation and the related approximations for short and long times are assessed. The analytical properties of the quasi‐exact formulation are evaluated using a proposed scaling procedure in order to define the validity domains of related approximations. Both quasi‐exact and approximate analytical equations are then studied with respect to their ability to reproduce numerically generated cumulative infiltrations from a 10 cm radius disc source for four soils (sand, loam, silt, and silty clay) at several initial saturations. The quasi‐exact formulation is suitable for sand, loam, and silt when their soil‐dependent and saturation‐independent shape parameters, γ and β, are properly chosen (between 0.75 and 1 and 0.3 and 1.7, respectively). Approximations derived for the same shape parameters can also be used, provided that their use is restricted to proposed validity intervals. However, none of these equations applies for silty clay, since its hydraulic properties do not fulfill the conditions required for the use of the quasi‐exact formulation.
Palladium in cubic silicon carbide: Stability and kinetics
Authors: Roma Guido
Published: December 2009

Several technological applications of silicon carbide are concerned with the introduction of palladium impurities. Be it intentional or not, this may lead to the formation of silicides. Not only this process is not well understood, but the basic properties of palladium impurities in silicon carbide, such as solubility or diffusion mechanisms, are far from being known. Here the stability and kinetics of isolated Pd impurities in cubic silicon carbide are studied by first principles calculations in the framework of density functional theory. The preferential insertion sites, as well as the main migration mechanisms, are analyzed and presented here, together with the results for solution and migration energies. The early stages of nucleation are discussed based on the properties of isolated impurities and the smallest clusters.
Magnetic anisotropy in vertically aligned diluted magnetic Mn:Ge semiconductor nanowires
Authors: Kim Ungkil , Park Tae-Eon , Kim Ilsoo , Seong Han-Kyu , Kim Myeong-Ha , Chang Joonyeon , Park Jae-Gwan , Choi Heon-Jin
Published: December 2009

Semiconductors doped with magnetic ion, the so-called diluted magnetic semiconductors, are promising candidates for spintronics. Herein, we report on magnetic anisotropy in Mn:Ge diluted magnetic semiconductor nanowires. We grew single crystal Mn:Ge nanowires vertically on a Ge substrate and found the anisotropy in ratios of orbital to spin magnetic moments in the angle-dependent x-ray magnetic circular dichroism measurements. Our further characterization indicates that this anisotropy comes from the unique characteristics of nanowires, i.e., very high aspect ratio in their shape and tensile stress along the longitudinal direction, which confine the spins along the longitudinal direction and make an easy axis in that direction.
Derivatives of spin dynamics simulations
Authors: Kuprov Ilya , Rodgers Christopher T.
Published: December 2009

We report analytical equations for the derivatives of spin dynamics simulations with respect to pulse sequence and spin system parameters. The methods described are significantly faster, more accurate, and more reliable than the finite difference approximations typically employed. The resulting derivatives may be used in fitting, optimization, performance evaluation, and stability analysis of spin dynamics simulations and experiments.
A growth diagram for plasma-assisted molecular beam epitaxy of GaN nanocolumns on Si(111)
Authors: Fernández-Garrido S. , Grandal J. , Calleja E. , Sánchez-García M. A. , López-Romero D.
Published: December 2009

The morphology of GaN samples grown by plasma-assisted molecular beam epitaxy on Si(111) was systematically studied as a function of impinging Ga/N flux ratio and growth temperature (730–850 °C). Two different growth regimes were identified: compact and nanocolumnar. A growth diagram was established as a function of growth parameters, exhibiting the transition between growth regimes, and showing under which growth conditions GaN cannot be grown due to thermal decomposition and Ga desorption. Present results indicate that adatoms diffusion length and the actual Ga/N ratio on the growing surface are key factors to achieve nanocolumnar growth.
A new photoelectrochemical test cell and its use for a combined two-electrode and three-electrode approach to cell testing
Authors: Esposito Daniel V. , Goue Ouloide Y. , Dobson Kevin D. , McCandless Brian E. , Chen Jingguang G. , Birkmire Robert W.
Published: December 2009

This paper describes the design, assembly, and operation of a photoelectrochemical (PEC) test cell that is relatively easy to construct and well suited for testing photoelectrode/counterelectrode combinations in a reproducible manner. The design of the cell permits measurements to be made in both two-electrode and three-electrode arrangements. The benefits of conducting both two-electrode and three-electrode measurements are illustrated using data obtained from the new test cell for a PEC system based on a polysulfide electrolyte, CdSe0.8Te0.2 photoanode, and tungsten monocarbide counterelectrode. It is shown that linear sweep voltammograms measured in three-electrode mode can be used to describe current transients recorded in a two-electrode cell modified by the addition of a reference electrode.
Diameter-dependent conductance of InAs nanowires
Authors: Scheffler Marc , Nadj-Perge Stevan , Kouwenhoven Leo P. , Borgström Magnus T. , Bakkers Erik P. A. M.
Published: December 2009

Electrical conductance through InAs nanowires is relevant for electronic applications as well as for fundamental quantum experiments. Here, we employ nominally undoped, slightly tapered InAs nanowires to study the diameter dependence of their conductance. By contacting multiple sections of each wire, we can study the diameter dependence within individual wires without the need to compare different nanowire batches. At room temperature, we find a diameter-independent conductivity for diameters larger than 40 nm, indicative of three-dimensional diffusive transport. For smaller diameters, the resistance increases considerably, in coincidence with a strong suppression of the mobility. From an analysis of the effective charge carrier density, we find indications for a surface accumulation layer.
Electron transport through asymmetric ferroelectric tunnel junctions: Current-voltage characteristics
Authors: Zimbovskaya Natalya A.
Published: December 2009

We have carried out calculations of current-voltage characteristics for the electron tunnel current through a junction with a thin insulating ferroelectric barrier assuming that interface transmissions for the left and right interfaces noticeably differ due to dissimilarity of the interfaces. Obtained conductance versus voltage and current versus voltage curves exhibit well distinguishable asymmetric hysteresis. We show that the asymmetry in the hysteretic effects could originate from the asymmetric bias voltage profile inside the junction. In particular, we analyze the hysteresis asymmetries occurring when the bias voltage distribution is low sensitive to the spontaneous polarization reversal.
Improved fiber optic device for in situ determination of electrolyte stratification in lead-acid batteries
Authors: Gajdátsy G. , Benedek F. , Kokavecz J. , Szabó G. , Kornis J.
Published: December 2009

A three-channel, highly sensitive, fiber optic device is presented to measure acid concentration in lead-acid batteries during their operation. The refractive index and thereby the concentration of sulfuric acid is measured by a bent, silica glass fiber tip, stripped off its cladding. Sensor heads of the device are small enough to be inserted at different positions in the cell of an ordinary, flooded lead-acid battery. Measuring the concentration of the electrolyte at different depths of the battery cell, acid stratification can be accurately determined. During the test of the instrument, about 0.3 Hz temporal and 0.05 wt % concentration resolutions were achieved while the temperature drift was found to be −0.25 wt %/°C.