bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetic Isotope Effects in Asymmetric Reactions
Authors: Giagou Thomas , Meyer Matthew P.
Published: July 2010

Kinetic isotope effects are exquisitely sensitive probes of transition structure. As such, kinetic isotope effects offer a uniquely useful probe for the symmetry‐breaking process that is inherent to stereoselective reactions. In this Concept article, we explore the role of steric and electronic effects in stereocontrol, and we relate these concepts to recent studies carried out in our laboratory. We also explore the way in which kinetic isotope effects serve as useful points of contact with computational models of transition structures. Finally, we discuss future opportunities for kinetic isotope effects to play a role in asymmetric catalyst development.
Model Studies in Heterogeneous Catalysis
Authors: Freund H.‐J.
Published: July 2010

I review a concept that models heterogeneous catalysis based on a surface‐science approach. It is shown that models catching part of the complexity of the real system, which is connected with the finite size of active components and the flexibility of the arrangement of atoms in the active component, play an important part in determining the activity and selectivity of the system. I have chosen several examples from our own laboratory to elaborate the details and will put those into perspective with respect to the literature. I will show that Pd nanoparticles in hydrogenation incorporate hydrogen, which turns out to be crucial for the actual hydrogenation step. Another example correlates the structure of vanadia monolayer catalysts with its reactivity in methanol oxidation. With a third example we address the question of charge on Au nanoparticles when anchored to an oxide surface, a problem heavily discussed in the literature. Further examples refer to ultrathin oxide film catalysts in which the oxide metal interface controls either the charge state of Au particles grown on the film, and, in a last example, the oxide film itself exhibits remarkable CO‐oxidation activity, which can be traced to a reactive intermediate structure of the ultrathin film.
On a TiNiSi‐Type Superstructure: Synthesis, Crystal and Electronic Structures of CaAgGe and Its Mn‐Substituted Derivative
Authors: Ponou Siméon
Published: July 2010

The compound CaAgGe and its Mn‐substituted derivative CaMn0.07Ag0.93Ge were synthesized by reaction of the element mixtures at high temperature. Their structures were refined from single‐crystal X‐ray diffraction data. CaAgGe crystallizes in the isomorphic (i3) superstructure of the TiNiSi type (CaCuGe type). The LMTO band structure calculations predicted the CaAgGe phase to be metallic. In addition, it appeared that the valence electron concentration is critical for the atomic ordering and the resulting superstructure. Thus, CaAgGe is one electron short per asymmetric unit, but a drastic narrowing of the electron shortage is achieved through the more complex atomic ordering in the supercell, relative to the simple TiNiSi type subcell. This results in the formation of {Ge2} dumbbells in the supercell, which ascribe greater electronic flexibility to the structure. Despite the fact that CaAgGe is not a Zintl phase in the strict definition as valence balanced intrinsic semiconductor, its structural aspects and transport properties can still be understood within the Zintl concept. The formal Zintl phase Ca3MnAg2Ge3 could be predicted from the theoretical calculations, but no significant phase width was observed experimentally in the substituted derivative Ca3Mn0.21Ag2.79Ge3.
Diffusion tensor imaging and white matter lesions at the subacute stage in mild traumatic brain injury with persistent neurobehavioral impairment
Authors: Messé Arnaud , Caplain Sophie , Paradot Gaëlle , Garrigue Delphine , Mineo Jean‐François , Soto Ares Gustavo , Ducreux Denis , Vignaud Frédéric , Rozec Gaëlle , Desal Hubert , Pélégrini‐Issac Mélanie , Montreuil Michèle , Benali Habib , Lehéricy Stéphane
Published: July 2010

Mild traumatic brain injury (mTBI) can induce long‐term behavioral and cognitive disorders. Although the exact origin of these mTBI‐related disorders is not known, they may be the consequence of diffuse axonal injury (DAI). Here, we investigated whether MRI at the subacute stage can detect lesions that are associated with poor functional outcome in mTBI by using anatomical images (T1) and diffusion tensor imaging (DTI). Twenty‐three patients with mTBI were investigated and compared with 23 healthy volunteers. All patients underwent an MRI investigation and clinical tests between 7 and 28 days (D15) and between 3 and 4 months (M3) after injury. Patients were divided in two groups of poor outcome (PO) and good outcome (GO), based on their complaints at M3. Groupwise differences in gray matter partial volume between PO patients, GO patients and controls were analyzed using Voxel‐Based Morphometry (VBM) from T1 data at D15. Differences in microstructural architecture were investigated using Tract‐Based Spatial Statistics (TBSS) and the diffusion images obtained from DTI data at D15. Permutation‐based non‐parametric testing was used to assess cluster significance at p < 0.05, corrected for multiple comparisons. Twelve GO patients and 11 PO patients were identified on the basis of their complaints. In PO patients, gray matter partial volume was significantly lower in several cortical and subcortical regions compared with controls, but did not differ from that of GO patients. No difference in diffusion variables was found between GO and controls. PO patients showed significantly higher mean diffusivity values than both controls and GO patients in the corpus callosum, the right anterior thalamic radiations and the superior longitudinal fasciculus, the inferior longitudinal fasciculus and the fronto‐occipital fasciculus bilaterally. In conclusion, PO patients differed from GO patients by the presence of diffusion changes in long association white matter fiber tracts but not by gray matter partial volume. These results suggest that DTI at the subacute stage may be a predictive marker of poor outcome in mTBI. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Estimating lifetime or episode‐of‐illness costs under censoring
Authors: Basu Anirban , Manning Willard G.
Published: July 2010

Many analyses of healthcare costs involve use of data with varying periods of observation and right censoring of cases before death or at the end of the episode of illness. The prominence of observations with no expenditure for some short periods of observation and the extreme skewness typical of these data raise concerns about the robustness of estimators based on inverse probability weighting (IPW) with the survival from censoring probabilities. These estimators also cannot distinguish between the effects of covariates on survival and intensity of utilization, which jointly determine costs. In this paper, we propose a new estimator that extends the class of two‐part models to deal with random right censoring and for continuous death and censoring times. Our model also addresses issues about the time to death in these analyses and separates the survival effects from the intensity effects. Using simulations, we compare our proposed estimator to the inverse probability estimator, which shows bias when censoring is large and covariates affect survival. We find our estimator to be unbiased and also more efficient for these designs. We apply our method and compare it with the IPW method using data from the Medicare–SEER files on prostate cancer. Copyright © 2010 John Wiley & Sons, Ltd.
Multiple roles of cytochrome c oxidase in mammalian cells under action of red and IR‐A radiation
Authors: Karu Tiina I.
Published: July 2010

This article reviews the current knowledge in photobiology and photomedicine about the influence of monochromatic, quasimonochromatic, and bread‐band radiation of red‐to‐near infrared (IR‐A) part on solar spectrum upon mammalian cells and human skin. The role of cytochrome c oxidase as the photoacceptor and photosignal transducer is underlined and its photosensitivity at certain circumstances is discussed. The role of ATP as a critical signaling molecule is discussed. © 2010 IUBMB IUBMB Life, 62(8): 607–610, 2010.
The glycemic response is a personal attribute
Authors: Whelan William J. , Hollar Danielle , Agatston Arthur , Dodson Hannah J. , Tahal Dimitri S.
Published: July 2010

The Glycemic Index (GI) is a measure of the extent of the change in blood glucose content (glycemic response) following consumption of digestible carbohydrate, relative to a standard such as glucose. We have explored whether the reported GIs of foods are a sufficient guide to a person wishing to avoid large glycemic responses and thereby avoid hyperglycemia. For this purpose, volunteers carried out multiple tests of four foods, following overnight fasting, measuring the glycemic response over 2 H. The areas under the blood glucose/time curves (AUCs) were compared. Each food tester displayed individual, characteristic glycemic responses to each food, unrelated to any other tester's response. Wide variations (up to 5‐fold) were seen between the average AUCs for the same test by different testers. The absolute magnitudes of the glycemic responses are important for individuals trying to control blood sugar and/or body weight, but using published GI lists as a guide to control the glycemic response is not fully informative. This is because in calculating the GI, individual glycemic responses to glucose are normalized to 100. GI values are, therefore, relative and are not necessarily a reliable guide to the person's actual individual AUC when consuming a food. Without knowledge of the person's characteristic blood glucose responses, reliance only on the GI may be misleading. © 2010 IUBMB IUBMB Life, 62(8): 637–641, 2010.
The impact of fire on redistribution of soil organic matter on a mediterranean hillslope under maquia vegetation type
Authors: Novara A. , Gristina L. , Bodì M.B. , Cerdà A.
Published: July 2010

Soil organic matter (SOM) changes affect the CO2 atmospheric levels and is a key factor on soil fertility and soil erodibility. Fire affects ecosystems and the soil properties due to heating and post‐fire soil erosion and degradation processes. In order to understand fire effects on soil organic carbon (SOC) balance research was undertaken on a fire‐prone ecosystem: the Mediterranean maquia. The spatial distribution of SOC was measured in a Burnt site 6 months after a wildfire and in a Control site. Samples were collected at two different depths (0–3 and 3–10 cm) and SOC was determined. The results show that 41·8 per cent of the SOC stock was lost. This is due to the removal of the burnt material by surface wash. No significant differences in SOC content were found for the subsurface samples between burnt and control plots. Those results show that ashes and charcoal are transported by runoff downslope and are subsequently deposited in the valley bottom and this is the key process that contributes the burial of SOC after a forest fire. SOC redistribution by water erosion is accelerated after forest fires and contribute to the degradation of soils located at the upper part of the hillslopes but causes the enrichment with SOM of the soils located at the valley bottom. Buried SOC in the bottoms valley terraces will contribute to the sequestration of carbon for longer. Conservation of abandoned terraces is a key policy to avoid land degradation and climate change. Copyright © 2010 John Wiley & Sons Ltd.
Who was the man who discovered the “Lewy bodies”?
Authors: Rodrigues e Silva Antonio M. , Geldsetzer Felix , Holdorff Bernd , Kielhorn Friedrich W. , Balzer‐Geldsetzer Monika , Oertel Wolfgang H. , Hurtig Howard , Dodel Richard
Published: July 2010

In 1912, Fritz Heinrich Lewy described neuronal inclusions in the brain of patients who had suffered from Paralysis agitans (i.e., Parkinson's disease). Later, these findings became the so‐called “Lewy bodies.” However, little is known about the man who made this discovery. Our aim was to investigate Lewy's private and professional life and to gather information for a detailed biography. We contacted over 100 archives, libraries, and museums in Germany, Poland, Switzerland, United Kingdom, and United States. Over 300 documents, publications, and photos were collected. Lewy was born in Berlin, Germany in 1885 and lived there until 1933. After his dismissal on racial grounds by the Nazis, Lewy emigrated to England in 1933 and to the United States of America in 1934, where he lived and worked until his death in 1950. This article gives a summary of Lewy's life and briefly presents his contribution to German and American neurology. © 2010 Movement Disorder Society
Altered pattern of motor cortical activation–inhibition during voluntary movements in Tourette syndrome
Authors: Franzkowiak Stephanie , Pollok Bettina , Biermann‐Ruben Katja , Südmeyer Martin , Paszek Jennifer , Jonas Melanie , Thomalla Götz , Bäumer Tobias , Orth Michael , Münchau Alexander , Schnitzler Alfons
Published: July 2010

In patients with Gilles de la Tourette syndrome (GTS) alterations of motor cortex (M1) excitability at rest have been evidenced. In contrast, there has so far been little research into changes of motor cortical reactivity during the time course of voluntary movements in GTS patients. The present study investigates neuromagnetic event‐related desynchronization (ERD) and event‐related synchronization (ERS) of bilateral M1 in 11 GTS patients and 11 healthy control subjects. ERD represents motor cortical activation, whereas ERS most likely indicates its inhibition. Subjects performed a self‐paced finger movement task while magnetoencephalography was used to record neuromagnetic activity. In GTS patients, ERD at beta frequency was significantly increased in the contralateral hemisphere before and during movements, whereas ERS following movement termination was increased in M1 ipsilateral. Ipsilateral ERS was inversely correlated with tic severity as determined by the Yale Global Tic Severity Rating Scale. The data of the present study support the hypothesis that during voluntary movements, motor cortical reactivity is pathologically altered in GTS patients. The observed pattern of increased activation (ERD) prior to and during movement execution followed by increased inhibition (ERS) after movement termination at beta frequency suggests abnormally increased motor cortical activation, possibly driving stronger inhibition. The stronger this inhibition is, the better symptoms appear to be controlled. © 2010 Movement Disorder Society
Juvenile levodopa‐responsive Parkinsonism with early orobuccolingual dyskinesias and cognitive impairment
Authors: Espay Alberto J. , Paviour Dominic C. , O'Sullivan John D. , Schmidt Robert E. , Revilla Fredy J. , Metman Leo Verhagen
Published: July 2010

A 13‐year old girl presented with slowly progressive rest tremor of the hands, bradykinesia, and rigidity. The symptoms improved with dopaminergic medications, but severe drug‐induced dyskinesias developed early. She subsequently developed cognitive slowing and difficulty initiating saccadic eye movements. She went on to have deep brain stimulation surgery. Experts discuss the syndromal diagnosis and predict the underlying pathology. The pathological diagnosis is given and clinical learning points are considered. © 2010 Movement Disorder Society
The “imprisoned illness:” Motor tic disorder in Rainer Maria Rilke'sNotebooks of Malte Laurids Brigge
Authors: Cavanna Andrea Eugenio , Pattumelli Maria Grazia , Quarto Tiziana , Ali Fizzah , Rickards Hugh
Published: July 2010

Rainer Maria Rilke's novelThe Notebooks of Malte Laurids Briggecontains a reference of interest for the catalog of literary portrayals oftiqueurs. In this article, we report his description of a Parisian character displaying multiple motor tic symptoms, along with a brief commentary. © 2010 Movement Disorder Society
Neuroanatomical correlates of apathy in Parkinson's disease: A magnetic resonance imaging study using voxel‐based morphometry
Authors: Reijnders Jennifer S.A.M. , Scholtissen Bart , Weber Wim E.J. , Aalten Pauline , Verhey Frans R.J. , Leentjens Albert F.G.
Published: July 2010

Apathy is generally defined as a disorder of motivation and is considered one of the most common neuropsychiatric disturbances in Parkinson's disease (PD). Only few studies addressed the neuroanatomical correlates of apathy in PD. The aim of this article was to determine the structural correlates of apathy in PD patients. Fifty‐five PD patients underwent a neuropsychiatric and neuropsychological examination, and a 3 T magnetic resonance imaging scan was acquired. A voxel‐based multiple regression analysis was used to calculate correlation between gray matter density and severity measures of apathy. Apathy correlates with decreased cognitive functioning and more depressive symptoms but not with more severe motor symptoms. High apathy scores were correlated with low gray matter density values in a number of cortical brain areas: the bilateral precentral gyrus (BA 4, 6), the bilateral inferior parietal gyrus (BA 40), the bilateral inferior frontal gyrus (BA 44, 47), the bilateral insula (BA 13), the right (posterior) cingulate gyrus (BA 24, 30, 31), and the right precuneus (BA 31). Apathy in PD correlates with reduced gray matter density in a number of brain regions. The involvement of the cingulate gyrus and inferior frontal gyrus is in line with the results of earlier studies addressing apathy in patients with Alzheimer's disease or depressive disorder. Further studies addressing the pathogenesis of apathy are needed. © 2010 Movement Disorder Society.
On meteorological droughts in tropical Pacific Islands: time‐series analysis of observed rainfall using Fiji as a case study
Authors: Deo Ravinesh C.
Published: July 2010

Analysis of historical droughts was undertaken by converting observed monthly rainfall over the period 1949–2008 to the Standardized Precipitation Index (SPI). The modified Mann–Kendall test applied on monthly rainfall showed statistically significant downward trends at significance level α = 0.01. The Sen's Slope, estimated from the time‐series, revealed statistically significant decreases in annual rainfall ranging from ∼13 to 47 mm year−1. Based on the SPI, drought duration and severity was non‐uniform across stations over the 60 year period. The strongest impacted stations were located in western and northern Fiji where rainfall deficiency for the period 1969–1988 led to a dramatic increase in moderate and severe droughts. The return periods of annual rainfall were much longer at these stations relative to those in outer‐lying islands. While rainfall increased over the period 1989–2008, the actual amounts did not exceed 1949–1968 totals, confirming a net shift towards drier conditions since the 1950s. This study has demonstrated that SPI can be a useful tool for diagnosis and monitoring meteorological droughts in tropical Pacific islands. Copyright © 2010 Royal Meteorological Society
Quantitative risk assessment case study for organic acid processes
Authors: Garland R. Wayne
Published: July 2010

Acetic acid is not a chemical covered by the OSHA PSM regulation, as its flash point is above the 100 F threshold for flammables; however, it is by no means a nonhazardous chemical. Eastman Chemical Company has a large number of processes containing acetic acid and related organic acids, and as a corporation, we wanted to assure that risk for these processes was at a tolerable level. To facilitate these risk assessments, flash point data was generated and a qualitative risk analysis was performed for a large number of process vessels. Selected quantitative risk assessment studies were then performed using fault tree/event tree methodology, comparing the assessed level of risk to generally accepted government and industry benchmarks as well as risk levels for some common activities. The highest contributors to risk were identified, analyzed with respect to current protective measures, and mitigated through the application of practical modifications, which reduced their risk to a tolerable level. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2010
Genetic lineage tracing, a powerful tool to investigate the embryonic organogenesis and adult organ maintenance of the pancreas
Authors: Kawaguchi Yoshiya , Takaori Kyoichi , Uemoto Shinji
Published: July 2010

Revealing the mechanism of adult organ maintenance and regeneration after injury is fundamental to our understanding of the pathogenesis of diseases. Considering the results of pulse and chase experiments using inducible insulin‐Cre or Elastase‐Cre, and more recently HNF1b‐Cre, adult pancreatic cells (beta, acinar, and duct cells) seem to be maintained by the self‐duplication of the existing cells, while there is still a dispute about whether adult beta‐cells are supplied from the duct cells. Here we describe the advantages and pitfalls of Cre‐mediated genetic lineage tracing experiments in the analysis of embryonic organogenesis and adult organ maintenance of the pancreas. This experimental technique enables us to visualize the specific cells and their progeny in vivo, and the combination of lineage tracing and other experimental procedures provides us with more detailed information on the mechanism of organogenesis and adult organ homeostasis.
Purified Canola Lutein Selectively Inhibits Specific Isoforms of Mammalian DNA Polymerases and Reduces Inflammatory Response
Authors: Horie Sho , Okuda Chiaki , Yamashita Takatoshi , Watanabe Kenichi , Kuramochi Kouji , Hosokawa Masashi , Takeuchi Toshifumi , Kakuda Makiko , Miyashita Kazuo , Sugawara Fumio , Yoshida Hiromi , Mizushina Yoshiyuki
Published: July 2010

In the screening of DNA polymerase (pol) inhibitor, we isolated lutein, a carotenoid, from the crude (unrefined) pressed oil of canola (low erucic acid rapeseed, Brassica napus L.). Commercially prepared carotenoids such as lutein (1), zeaxanthin (2), β‐cryptoxanthin (3), astaxanthin (4), canthaxanthin (5), β‐carotene (6), lycopene (7), capsanthin (8), fucoxanthin (9) and fucoxanthinol (10), were investigated for the inhibitory activities of pols. Compounds 1, 2 and 8 exhibited strong inhibition of the activities of mammalian pols β and λ, which are DNA repair‐ and/or recombination‐related pols. On the other hand, all carotenoids tested had no influence on the activity of a mammalian pol α, which is a DNA replicative pol. Lutein (1) was the strongest pol inhibitor of mammalian pols β and λ in the prepared ten carotenoids tested, but did not influence of the activities of mammalian pols α, γ, δ and ε. The tendency for pols β and λ inhibition by these carotenoids showed a positive correlation with the suppression of TPA (12‐O‐tetradecanoylphorbol‐13‐acetate)‐induced inflammation. These results suggest that cold pressed unrefined canola/rapeseed oil, or other oils with high levels of lutein and other carotenoids, may be useful for their anti‐inflammatory properties.
Age and growth of franciscana dolphins, Pontoporia blainvillei (Cetacea: Pontoporiidae) incidentally caught off southern Brazil and northern Argentina
Authors: Botta Silvina , Secchi Eduardo R. , Muelbert Mônica M.C. , Danilewicz Daniel , Negri Maria Fernanda , Cappozzo Humberto Luis , Hohn Aleta A.
Published: July 2010

Age and length data of 291 franciscana dolphins (Pontoporia blainvillei) incidentally captured on the coast of Rio Grande do Sul State (RS), southern Brazil, were used to fit growth curves using Gompertz and Von Bertalanffy growth models. A small sample of franciscanas (N = 35) from Buenos Aires Province (BA), Argentina, were used to see if there are apparent growth differences between the populations. Male and female franciscana samples from both areas were primarily (78–85%) <4 years of age. The Von Bertalanffy growth model with a data set that excluded animals <1 year of age provided the best fit to data. Based on this model, dolphins from the RS population reached asymptotic length at 136.0 cm and 158.4 cm, for males and females, respectively. No remarkable differences were observed in the growth trajectories of males and females between the RS and BA populations.
Defining favourable reference values for bird populations in Italy: setting long-term conservation targets for priority species
Authors: BRAMBILLA MATTIA , GUSTIN MARCO , CELADA CLAUDIO
Published: July 2010

Setting favourable reference values (FRV) for conservation targets may help in assessing the conservation status of species and habitats. FRVs should be expressed through population size or demographic parameters that are likely to ensure the long-term persistence of a species across its range. We developed a conceptual framework for defining FRVs for Italian birds included in Annex I of the European Union’s Wild Birds Directive 79/409/CEE. The approach was based on demographic trends, current population size and the minimum viable population concept. We subdivided bird species according to abundance at the national scale, spatial distribution in discrete isolated populations and/or biogeographic categories. FRVs based on population viability analysis (PVA) were provided for populations of less than 2,500 pairs. For species with more than 2,500 pairs and a wide, more or less continuous range, the FRV was expressed in terms of breeding density at different spatial scales for non-colonial species. Out of the 88 species considered, we were able to formulate FRVs based on PVA for 47 populations belonging to 21 species, and breeding density for 15 further species; lack of adequate data prevented us from defining FRVs for the remaining species. Further work should focus on the translation of FRV density values into population size and on the definition of reference values for range and habitat.
Omic data from evolved E. coli are consistent with computed optimal growth from genome‐scale models
Authors: Lewis Nathan E , Hixson Kim K , Conrad Tom M , Lerman Joshua A , Charusanti Pep , Polpitiya Ashoka D , Adkins Joshua N , Schramm Gunnar , Purvine Samuel O , Lopez‐Ferrer Daniel , Weitz Karl K , Eils Roland , König Rainer , Smith Richard D , Palsson Bernhard Ø
Published: July 2010

After hundreds of generations of adaptive evolution at exponential growth, Escherichia coli grows as predicted using flux balance analysis (FBA) on genome‐scale metabolic models (GEMs). However, it is not known whether the predicted pathway usage in FBA solutions is consistent with gene and protein expression in the wild‐type and evolved strains. Here, we report that >98% of active reactions from FBA optimal growth solutions are supported by transcriptomic and proteomic data. Moreover, when E. coli adapts to growth rate selective pressure, the evolved strains upregulate genes within the optimal growth predictions, and downregulate genes outside of the optimal growth solutions. In addition, bottlenecks from dosage limitations of computationally predicted essential genes are overcome in the evolved strains. We also identify regulatory processes that may contribute to the development of the optimal growth phenotype in the evolved strains, such as the downregulation of known regulons and stringent response suppression. Thus, differential gene and protein expression from wild‐type and adaptively evolved strains supports observed growth phenotype changes, and is consistent with GEM‐computed optimal growth states.
A diffusion‐based neurite length‐sensing mechanism involved in neuronal symmetry breaking
Authors: Toriyama Michinori , Sakumura Yuichi , Shimada Tadayuki , Ishii Shin , Inagaki Naoyuki
Published: July 2010

Although there has been significant progress in understanding the molecular signals that change cell morphology, mechanisms that cells use to monitor their size and length to regulate their morphology remain elusive. Previous studies suggest that polarizing cultured hippocampal neurons can sense neurite length, identify the longest neurite, and induce its subsequent outgrowth for axonogenesis. We observed that shootin1, a key regulator of axon outgrowth and neuronal polarization, accumulates in neurite tips in a neurite length‐dependent manner; here, the property of cell length is translated into shootin1 signals. Quantitative live cell imaging combined with modeling analyses revealed that intraneuritic anterograde transport and retrograde diffusion of shootin1 account for its neurite length‐dependent accumulation. Our quantitative model further explains that the length‐dependent shootin1 accumulation, together with shootin1‐dependent neurite outgrowth, constitutes a positive feedback loop that amplifies stochastic fluctuations of shootin1 signals, thereby generating an asymmetric signal for axon specification and neuronal symmetry breaking.
Hard x-ray photoemission spectroscopic investigation of palladium catalysts immobilized on a GaAs(001) surface
Authors: Shimoda M. , Konishi T. , Tateishi K. , Toujyou T. , Tsukamoto S. , Nishiwaki N. , Arisawa M. , Hoshiya N. , Shuto S. , Isomura N. , Yokota H. , Furukawa Y. , Iizuka K. , Ogiwara T. , Isozaki Y. , Yamashita Y. , Yoshikawa H. , Ueda S. , Kobayashi K.
Published: July 2010

We present studies on the structure and chemical states of a catalyst developed by immobilizing palladium on S-terminated GaAs(001). Hard x-ray photoelectron spectroscopy (HX-PES) of core-level and valence band photoemission consistently indicates that the organopalladium molecules are reduced on the surface yielding Pd nanoparticles with a metallic nature. This finding is supported by high-resolution observations using scanning electron microscopy and backscattered electron image. HX-PES results also reveal that a portion of S atoms forming the S-termination is oxidized during the formation of Pd nanoparticles.
Communication: High-frequency acoustic excitations and boson peak in glasses: A study of their temperature dependence
Authors: Ruta B. , Baldi G. , Giordano V. M. , Orsingher L. , Rols S. , Scarponi F. , Monaco G.
Published: July 2010

The results of a combined experimental study of the high-frequency acoustic dynamics and of the vibrational density of states (VDOS) as a function of temperature in a glass of sorbitol are reported here. The excess in the VDOS at ∼4.5 meV over the Debye, elastic continuum prediction (boson peak) is found to be clearly related to anomalies observed in the acoustic dispersion curve in the mesoscopic wavenumber range of few nm−1. The quasiharmonic temperature dependence of the acoustic dispersion curves offers a natural explanation for the observed scaling of the boson peak with the elastic medium properties.
Fabrication of multilayer Laue lenses by a combination of pulsed laser deposition and focused ion beam
Authors: Liese Tobias , Radisch Volker , Krebs Hans-Ulrich
Published: July 2010

X-ray diffractive techniques using Fresnel zone plate lenses of various forms are of great technical interest because of their ability to form images at very high spatial resolution, but the zone plates are unfortunately very hard to produce by lithography. Alternatively, multilayer Laue lenses (MLLs) and multilayer zone plates are used due to the higher and easily adjustable aspect ratio necessary for different wavelengths. In this paper, the fabrication of a MLL by a combination of pulsed laser deposition and focused ion beam machining is described. All steps of the production of a Ti/ZrO2 microlens test structure with focal length of 220 μm (for a wavelength of 2.88 nm in the “water window” regime) are explained in detail. It is shown that this combination of two powerful techniques is very effective for the fabrication of MLL. All steps can be done in a very precise and controlled way without introducing damage to the grown multilayer structures.
Simple nonlinearity evaluation and modeling of low-noise amplifiers with application to radio astronomy receivers
Authors: Casas F. J. , Pascual J. P. , de la Fuente M. L. , Artal E. , Portilla J.
Published: July 2010

This paper describes a comparative nonlinear analysis of low-noise amplifiers (LNAs) under different stimuli for use in astronomical applications. Wide-band Gaussian-noise input signals, together with the high values of gain required, make that figures of merit, such as the 1 dB compression (1 dBc) point of amplifiers, become crucial in the design process of radiometric receivers in order to guarantee the linearity in their nominal operation. The typical method to obtain the 1 dBc point is by using single-tone excitation signals to get the nonlinear amplitude to amplitude (AM-AM) characteristic but, as will be shown in the paper, in radiometers, the nature of the wide-band Gaussian-noise excitation signals makes the amplifiers present higher nonlinearity than when using single tone excitation signals. Therefore, in order to analyze the suitability of the LNA’s nominal operation, the 1 dBc point has to be obtained, but using realistic excitation signals. In this work, an analytical study of compression effects in amplifiers due to excitation signals composed of several tones is reported. Moreover, LNA nonlinear characteristics, as AM-AM, total distortion, and power to distortion ratio, have been obtained by simulation and measurement with wide-band Gaussian-noise excitation signals. This kind of signal can be considered as a limit case of a multitone signal, when the number of tones is very high. The work is illustrated by means of the extraction of realistic nonlinear characteristics, through simulation and measurement, of a 31 GHz back-end module LNA used in the radiometer of the QUIJOTE (Q U I JOint TEnerife) CMB experiment.
Electro-optic switching element for dielectric-loaded surface plasmon polariton waveguides
Authors: Krasavin A. V. , Zayats A. V.
Published: July 2010

We present three-dimensional numerical modeling of an active electronically controlled switching element for fully-functional plasmonic circuits based on dielectric-loaded surface plasmon polariton waveguides. It has been demonstrated that the transmission of the guided mode through a highly wavelength-selective waveguide ring resonator (WRR) can be efficiently controlled with very small refractive index changes of the order of 10−3, achievable through the electro-optic effect in nonlinear materials. Furthermore, we have introduced a figure of merit for such active plasmonic elements and optimized the active WRR performance in terms of its sensitivity and size. These results shows the potential to create high performance 600 nm radius plasmonic WRR switches.
Spatially resolved characterization of InGaAs/GaAs quantum dot structures by scanning spreading resistance microscopy
Authors: Hakkarainen T. , Douhéret O. , Anand S. , Fu L. , Tan H. H. , Jagadish C.
Published: July 2010

Cross-sectional scanning spreading resistance microscopy (SSRM) is used to investigate stacked InGaAs/GaAs quantum dot (QD) structures with different doping schemes. Spatially resolved imaging of the QDs by SSRM is demonstrated. The SSRM contrast obtained for the QD layers is found to depend on doping in the structure. In the undoped structures both QD-layers and QDs within the layers could be resolved, while in the doped structures the QD layers appear more or less uniformly broadened. The origin of the SSRM contrast in the QD layer in the different samples is discussed and correlated with doping schemes.
Improved photoelectrochemical responses of Si and Ti codoped α-Fe2O3 photoanode films
Authors: Zhang Minglong , Luo Wenjun , Li Zhaosheng , Yu Tao , Zou Zhigang
Published: July 2010

We studied photoelectrochemical performance of the undoped, Si-doped, Ti-doped, and codoped α-Fe2O3 film prepared by ultrasonic spray pyrolysis. Since the ions radius of Si4+<Fe3+<Ti4+, Si and Ti codoping can balance the ion radius difference between Fe3+ and Si4+ (or Ti4+) and increase the donor concentration. Their donor concentrations, calculated from slopes of the Mott–Schottky plots, are 9.10×1018 cm−3, 1.89×1020 cm−3, 2.04×1020 cm−3, and 7.06×1020 cm−3, respectively. Incident photon to current efficiency of the codoped film is 34% at 365 nm and 0.6 V versus Ag/AgCl, much higher than 10%, 20%, and 22% for the undoped, Si-doped, and Ti-doped film, respectively.
Synchrotron radiation circular dichroism spectroscopy-defined structure of the C-terminal domain of NaChBac and its role in channel assembly
Authors: Powl Andrew M. , O’Reilly Andrias O. , Miles Andrew J. , Wallace B. A.
Published: July 2010

Extramembranous domains play important roles in the structure and function of membrane proteins, contributing to protein stability, forming association domains, and binding ancillary subunits and ligands. However, these domains are generally flexible, making them difficult or unsuitable targets for obtaining high-resolution X-ray and NMR structural information. In this study we show that the highly sensitive method of synchrotron radiation circular dichroism (SRCD) spectroscopy can be used as a powerful tool to investigate the structure of the extramembranous C-terminal domain (CTD) of the prokaryotic voltage-gated sodium channel (Na
V
) from
Bacillus halodurans
, NaChBac. Sequence analyses predict its CTD will consist of an unordered region followed by an α-helix, which has a propensity to form a multimeric coiled-coil motif, and which could form an association domain in the homotetrameric NaChBac channel. By creating a number of shortened constructs we have shown experimentally that the CTD does indeed contain a stretch of ∼20 α-helical residues preceded by a nonhelical region adjacent to the final transmembrane segment and that the efficiency of assembly of channels in the membrane progressively decreases as the CTD residues are removed. Analyses of the CTDs of 32 putative prokaryotic Na
V
sequences suggest that a CTD helical bundle is a structural feature conserved throughout the bacterial sodium channel family.
Nucleotide‐binding domain of phosphoglycerate kinase 1 reduces tumor growth by suppressing COX‐2 expression
Authors: Ho Ming‐Yi , Tang Shye‐Jye , Ng Wailap V. , Yang Winnie , Leu Shr‐Jeng J. , Lin Ying‐Chun , Feng Chi‐Kuang , Sung Jung‐Sung , Sun Kuang‐Hui
Published: July 2010

Phosphoglycerate kinase 1 (PGK‐1) is a multifunctional protein that is involved in the glycolytic pathway and the generation of the angiogenesis inhibitor angiostatin. In a previous study, we showed that the overexpression of full‐length PGK‐1 in Lewis lung carcinoma (LLC‐1) can reduce tumor growth in vivo by downregulation of COX‐2 expression. Phosphoglycerate kinase 1 has two functional domains: a catalytic domain (CD); and a nucleotide‐binding domain (NBD). To identify the functional domain of PGK‐1 responsible for its antitumor effects, we evaluated the tumorigenicity of LLC‐1 cells overexpressing full‐length PGK‐1 (LLC‐1/PGK), CD (LLC‐1/CD), and NBD (LLC‐1/NBD). Although no difference in tumor cell growth was observed in vitro, the tumor invasiveness was reduced in the LLC‐1/PGK, LLC‐1/CD, and LLC‐1/NBD cells compared to parental LLC‐1 cells in vivo. In addition, in vivo tumor growth retardation by LLC‐1/CD and LLC‐1/NBD cells was observed, similar to that by LLC‐1/PGK cells. However, the reduced stability of COX‐2 mRNA and downregulation of the COX‐2 protein and its metabolite, prostaglandin E2, was only found in LLC‐1/PGK and LLC‐1/NBD cells. Low levels of COX‐2 were also observed in the tumor mass formed by the modified cells when injected into mice. The results indicate that COX‐2 suppression by PGK‐1 is independent of its catalytic activity. COX‐2 targeting by PGK‐1 can be attributed to its NBD and is probably a result of the destabilization of COX‐2 gene transcripts brought about by the mRNA‐binding property of PGK‐1. (Cancer Sci 2010; 101: 2411–2416)
Delayed drug hypersensitivity: models of T‐cell stimulation
Authors: Adam Jacqueline , Pichler Werner J. , Yerly Daniel
Published: July 2010

Drug‐induced hypersensitivity reactions can cause a variety of serious diseases by involving drug‐specific T‐cells. Many of these reactions have been explained by the hapten concept, which postulates that small chemical compounds need to bind covalently to proteins to be recognized by the immune system. Due to their chemical reactivity, haptens stimulate the innate immunity by binding covalently to endogenous proteins and form so called hapten‐carrier complexes, which are antigenic and induce T‐cell responses. In recent years, a new concept has been developed since drug‐induced hypersensitivity reactions were also observed with chemically unreactive drugs. This concept implies direct and reversible interactions of the drug between T‐cell receptors (TCR) and major histocompatability complex (MHC) molecules. Therefore it was termed pharmacological interactions with immune receptors (p‐i concept). Early observations on drug reacting T‐cell clones (TCC) let believe that drugs bind first to the T‐cell receptor since HLA molecules could be exchanged without affecting the drug reactivity. However, MHC molecules were always required for full activation of TCC. According to its strong HLA‐B*5701 association, recent data on abacavir suggest that a drug could first bind to the peptide binding groove of the MHC molecule. The thereby modified HLA molecule can then be recognized by specific T‐cells. Consequently, two types of reactions based on the p‐i mechanism may occur: on the one hand, drugs might preferentially bind directly to the TCR, whereas in defined cases with strong HLA association, drugs might bind directly to the MHC molecule.
Exploring the link between impulsivity and peer relations in 5‐ and 6‐year‐old children
Authors: Gomes L. , Livesey D.
Published: July 2010

Background  In recent years there has been an increased interest in the behavioural correlates of poor peer relations in childhood. It is now apparent that early poor peer relations are associated with negative future outcomes. The present study investigated whether behaviours that reflect impulsivity or require response inhibition are uniquely linked to children's peer relations.

Methods  Five‐ and 6‐year‐old children's impulsivity was assessed using the teacher‐rated impulsivity scale (TRIS), while the stop signal task and a modified version of Manly et al.'s opposite worlds task were employed as measures of response inhibition. In addition, peer relations measures were obtained for each child by asking their peers to indicate on a peer rating scale how much they would like to play with them.

Results  It was found that children's scores on the TRIS correlated significantly with peer relations measures (sociometric preference, peer acceptance and peer rejection) after controlling for gender, age and intelligence. Children rated by their teachers to be more impulsive had poorer peer relations. While there was a significant correlation between TRIS and stop‐signal task performance, little relationship was found between either of the response inhibition measures and children's peer relations.

Conclusions  The findings indicate that impulsivity is associated with children's poor relations with their peers and that this association is dependent upon the measure of impulsivity used. Whereas the more subjective teacher‐ratings of impulsiveness did correlate with peer relations, the more objective behavioural measures of response inhibition, (thought to directly measure impulsivity), did not. The difference between these measures needs further investigation. While the data are correlational and causal direction can only be speculated, a practical implication of the finding of an association between impulsivity and peer acceptance is that adoption of strategies to minimize impulsive behaviour may improve the poor peer relations of children.
MBSJ MCC Young Scientist Award 2009 REVIEW: Selective autophagy regulates various cellular functions
Authors: Komatsu Masaaki , Ichimura Yoshinobu
Published: July 2010

Autophagy is a self‐eating system conserved among eukaryotes, in which cellular components including organelles are entrapped into a double membrane structure called the autophagosome and then degraded by lysosomal hydrolases. In addition to its role in supplying amino acids in response to nutrient starvation, autophagy is involved in quality control to maintain cell health. Thus, inactivation of autophagy causes the formation of cytoplasmic protein inclusions, which comprise misfolded proteins and the accumulation of many degenerated organelles, resulting in liver injury, diabetes, myopathy and neurodegeneration. Furthermore, although autophagy has been considered nonselective, increasing evidence points to the selectivity of autophagy in sorting vacuolar enzymes and removal of aggregate‐prone proteins and unwanted organelles. Such selectivity allows diverse cellular regulation, similar to the ubiquitin proteasome pathway. In this review, we discuss the physiological roles of selective autophagy and their molecular mechanisms.
The Effects of Damaged Kernel Caused by Combine Harvester Settings on Milled Rice Free Fatty Acid Levels
Authors: Feliz D.J. , Proctor A. , Monsoor M. A. , Eason R.L.
Published: July 2010

Milled rice surface oil and free fatty acid (FFA) contents determine rice acceptability to the brewing industry. Both could subsequently contribute to beer off‐flavors and thus compromise milled rice brewing quality. Controlling milled rice FFA by harvesting practices could be important in maintaining brewing quality as some rough rice is damaged by hull removal and/or bran disruption during harvesting. To determine the effect of harvester speed on kernel damage, the long‐grain rice variety Cocodrie was harvested at 3 different combine harvester settings and the percent of damaged kernel (w/w) was measured. Combine harvester cylinder speed had a significant effect on rough rice kernel damage. The percentages of damaged kernels for 550, 850, and 1000 rpm cylinder speeds were 1.2%, 4.0%, and 9.0%, respectively. The FFA level of milled rice with varying amount of damaged kernels was investigated over 6 mo of storage. The faster harvester cylinder speeds resulted with time in significantly greater FFA levels in “as‐harvested” rice. The FFA content of 1000 rpm as‐harvested rice almost reached the 0.1% (w/w) level. The greater the amount of damaged kernel, the greater was the milled rice FFA level, and it was significantly greater than milled rice with no damaged kernels during accelerated storage. The as‐harvested rice with 1000 rpm had the highest FFA level, followed by 850 and 500 rpm.
Intra‐regional Tax Competition and Economic Geography
Authors: Hühnerbein Ossip , Seidel Tobias
Published: July 2010

In this paper, we extend a solvable version of the core–periphery agglomeration model to four countries located in two regions to show that governments in the agglomerated region may not be able to levy a tax premium on mobile capital if there is intra‐regional tax competition. This hypothesis challenges standard results in the literature and delegates clarification to empirical research. With respect to welfare, we find that intra‐regional tax competition is detrimental from a welfare perspective and that tax harmonisation unambiguously makes both countries in the core region better off.
Insulin Is Released from Rat Brain Neuronal Cells in Culture
Authors: Clarke Derrel W. , Mudd Laura , Boyd Frederick T. , Fields Michael , Raizada Mohan K.
Published: July 2010

Abstract: Depolarization of neuronal cells in primary culture from the rat brain by potassium ions in the presence of calcium or by veratridine caused a greater than threefold stimulation of release of immunoreactive insulin. HPLC of the released insulin immunoreactivity from the neuronal cultures comigrated with the two rat insulins. The depolarization‐induced release of insulin was inhibited by cycloheximide and was specific for neuronal cultures since potassium ions failed to cause the release in comparably prepared astrocytic glial cells from the rat brain. Prelabelling of neuronal cultures with [3H]leucine followed by depolarization resulted in the release of radioactivity that immunoprecipitated with insulin antibody. The release of [3H]insulin was biphasic. These observations suggest that neuronal cells from the brain have the capacity to synthesize insulin that could be released under depolarization conditions.