bluuebunny/crossref_metadata_2025 huggingface dataset:
DNA‐Templated Synthesis of Cationic Poly(3,4‐ethylenedioxythiophene) Derivative for Supercapacitor Electrodes
Authors: Tang Hongwei , Chen Lili , Xing Chengfen , Guo Yu‐Guo , Wang Shu
Published: September 2010

A new cationic poly(3,4‐ethylenedioxythiophene)–DNA composite (P(EDOT‐N)‐DNA) has been prepared by in situ chemical oxidative polymerization of EDOT‐N monomer in the presence of salmon DNA as template. Scanning electron microscopy shows that the P(EDOT‐N)–DNA composite forms a porous pattern with a high surface area that is favorable for ion diffusion throughout the materials, which leads to improved capacitive activity. The P(EDOT‐N)–DNA composite exhibits superior capacitance behavior as well as good charge–discharge reversibility. The P(EDOT‐N)–DNA composite shows low cytotoxicity to living cells even at a concentration of 300 mg · L−1. The good biocompatibility of P(EDOT‐N)–DNA imparts good potential as an environmentally friendly electrode material for energy storage devices, even in a biological environment owing to the combination of DNA with conjugated polymers.

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Enhanced ionic conductivity in PEO/PMMA glassy miscible blends: Role of nano‐confinement of minority component chains
Authors: Jeddi Kazem , Qazvini Nader Taheri , Jafari Seyed Hassan , Khonakdar Hossein Ali
Published: September 2010

AC impedance spectroscopy was used to investigate the ionic conductivity of solution cast poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA) blends doped with lithium perchlorate. At low PEO contents (below overlap weight fraction w*), ionic conductivities are almost low. This could be due to nearly distant PEO chains in blend, which means ion transportation cannot be performed adequately. However, at weight fractions well above w*, a significant increase in ionic conductivity was observed. This enhanced ionic conductivity mimics the PEO segmental relaxation in rigid PMMA matrix, which can be attributed to the accelerated motions of confined PEO chains in PMMA matrix. At PEO content higher than 20 wt % the conductivity measured at room temperature drops due to crystallization of PEO. However by increasing temperature to temperatures well above the melting point of PEO, a sudden increase of conductivity was observed which was attributed to phase transition from crystalline to amorphous state. The results indicate that some PEO/PMMA blends with well enough PEO content, which are structurally solid, can be considered as an interesting candidate for usage as solid‐state electrolytes in Lithium batteries. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2065–2071, 2010
Application of imaging mass spectrometry for the analysis of Oryza sativa rice
Authors: Zaima Nobuhiro , Goto‐Inoue Naoko , Hayasaka Takahiro , Setou Mitsutoshi
Published: September 2010

Rice is one of the most important food crops in the world and new varieties have been bred for specific purposes, such as the development of drought‐resistance, or the enrichment of functional food factors. The localization and composition of metabolites in such new varieties must be investigated because all artificial interventions are expected to change the metabolites of rice. Imaging mass spectrometry using matrix‐assisted laser desorption/ionization (MALDI‐IMS) is a suitable tool for investigating the localization and composition of metabolites; however, suitable methodologies for the MALDI‐IMS analysis of rice have not yet been established. In this study, we optimized the methods for analyzing rice grains by MALDI‐IMS using adhesive film and found the characteristic distribution of metabolites in rice. Lysophosphatidylcholine (LPC) was localized in the endosperm. Phosphatidylcholine (PC), γ‐oryzanol and phytic acid were localized in the bran (germ and seed coat), and α‐tocopherol was distributed in the germ (especially in the scutellum). In addition, MALDI‐IMS revealed the LPC and PC composition of the rice samples. The LPC composition, LPC (1‐acyl 16:0), LPC (1‐acyl 18:2), LPC (1‐acyl 18:1) and LPC (1‐acyl 18:0), was 59.4 ± 4.5%, 19.6 ± 2.5%, 14.2 ± 4.5% and 6.8 ± 1.4%. The PC composition, PC (diacyl 16:0/18:2), PC (diacyl 16:0/18:1), PC (diacyl 18:1/18:3), PC (diacyl 18:1/18:2) and PC (diacyl 18:1/18:2), was 19.6 ± 1.0%, 21.0 ± 1.0%, 15.0 ± 1.4%, 26.7 ± 0.7% and 17.8 ± 1.9%. This approach can be applied to the assessment of metabolites not only in rice, but also in other foods for which the preparation of sections is a challenging task. Copyright © 2010 John Wiley & Sons, Ltd.
Methamphetamine induces striatal neurokinin‐1 receptor endocytosis primarily in somatostatin/NPY/NOS interneurons and the role of dopamine receptors in mice
Authors: Wang Jing , Angulo Jesus A.
Published: September 2010

Methamphetamine (METH) is a psychostimulant that induces long‐term deficits of dopamine terminal markers and apoptotic cell death in the striatum. Our laboratory demonstrated that pharmacological blockade of the neurokinin‐1 receptor attenuated the METH‐induced damage to the striatal dopamine terminals and the apoptotic cell death of some striatal neurons. Here, we used histological methods to assess the effect of METH on neurokinin‐1 receptor trafficking in the striatum as an indirect index of signaling by the neuropeptide substance P (natural ligand for this receptor). Male mice received a single injection of METH (30 mg/kg, i.p.) and were sacrificed 30 min later. Immunohistofluorescence confocal microscopy confirmed that the neurokinin‐1 receptor is located on cholinergic and somatostatin interneurons of the striatum. METH induced the trafficking of the neurokinin‐1 receptor from the membrane into cytoplasmic endosomes primarily in the somatostatin/NPY/NOS interneurons, and this phenomenon was attenuated by antagonists of the dopamine D1 (SCH‐23390), D2 (raclopride), or neurokinin‐1 (WIN‐51,708) receptors. These data demonstrate that METH induces the trafficking of the striatal neurokinin‐1 receptors principally in the somatostatin/NPY/NOS interneurons and that this phenomenon is dependent on the activity of dopamine D1 and D2 receptors. Synapse, 2011. © 2010 Wiley‐Liss, Inc.
Phenylketonuria as a model for protein misfolding diseases and for the development of next generation orphan drugs for patients with inborn errors of metabolism
Authors: Muntau Ania C. , Gersting Søren W.
Published: September 2010

The lecture dedicated to Professor Horst Bickel describes the advances, successes, and opportunities concerning the understanding of the biochemical and molecular basis of phenylketonuria and the innovative treatment strategies introduced for these patients during the last 60 years. These concepts were transferred to other inborn errors of metabolism and led to significant reduction in morbidity and to an improvement in quality of life. Important milestones were the successful development of a low‐phenylalanine diet for phenylketonuria patients, the recognition of tetrahydrobiopterin as an option to treat these individuals pharmacologically, and finally market approval of this drug. The work related to the discovery of a pharmacological treatment led metabolic researchers and pediatricians to new insights into the molecular processes linked to mutations in the phenylalanine hydroxylase gene at the cellular and structural level. Again, phenylketonuria became a prototype disorder for a previously underestimated but now rapidly expanding group of diseases: protein misfolding disorders with loss of function. Due to potential general biological mechanisms underlying these disorders, the door may soon open to a systematic development of a new class of pharmaceutical products. These pharmacological chaperones are likely to correct misfolding of proteins involved in numerous genetic and nongenetic diseases.
Which variables are associated with pain intensity and treatment response in advanced cancer patients?— Implications for a future classification system for cancer pain
Authors: Knudsenl Anne Kari , Brunellil Cinzia , Kaasal Stein , Apolonel Giovanni , Corlil Oscar , Montanaril Mauro , Fainsingerl Robin , Aassl Nina , Fayersl Peter , Caracenil Augusto , Klepstadl Pål ,   On behalf of the European Palliative Care Research Collaborative (EPCRC) and the European Pharmacogenetic Study (EPOS)
Published: September 2010

Background: This study is part of a research program to reach consensus on an international cancer pain classification system. A confirmative and explorative approach was applied to investigate which of the variables identified in the literature, by experts and patients that are associated with pain.

Methods: Data from an international, multicentre, cross‐sectional study of cancer patients treated with opioids were investigated. Dependent variables were: average pain, worst pain, and pain relief (11‐point Numerical Rating Scales). Forty‐six independent variables were chosen based upon previous studies. Bivariate analyses identified independent variables associated with at least one of the dependent ones; 21 were included in multivariate linear regression analyses.

Results: Two thousand two hundred and seventy‐eight patients were investigated; 52% males, mean age 62 years, mean Karnofsky Performance Status 59%, mean daily opioid oral equivalent dose 341 mg. Fifty‐eight percent had breakthrough pain. Mean pain scores were: average pain 3.5, worst pain 5.3 and pain relief 74%. Variables most strongly associated with these three dependent variables were: breakthrough pain, psychological distress, sleep, and opioid dose.

Conclusions: Breakthrough pain and psychological distress were confirmed as key variables of a future classification system. Candidate variables were: sleep, opioid dose, pain mechanism, use of non‐opioids, pain localisation, cancer diagnosis, location of metastases, and addiction.
Comparison of the TVT SECUR System “hammock” and “U” tape positions for management of stress urinary incontinence
Authors: Liapis Angelos , Bakas Panagiotis , Creatsas Georgios
Published: September 2010

Objective

To assess the efficacy and complications associated with use of the TVT SECUR System device with placement of the tape in either a “hammock” or “U” position for management of stress urinary incontinence (SUI).

Methods

A prospective study of patients with SUI allocated into one of two groups: “hammock” or “U” tape placement. Preoperative urodynamic results were compared with results at the 6‐month and 1‐year follow up. Outcome measures were objective cough test assessment and subjective patient responses to a questionnaire at follow up.

Results

Of 82 patients included in the study, 43 comprised the “hammock” group and 39 comprised the “U” group. The objective cure rate at 1‐year follow up was 62.8% (n = 27) in the “hammock” group and 71.8% (n = 28) in the “U” group. At 1‐year follow up, the subjective cure, improvement, and failure rates for the “hammock” group were 60.5%, 13.9%, and 25.7% respectively, and 69.2%, 12.8%, and 17.9% respectively, for the “U” group.

Conclusion

The efficacy of the TVT SECUR System was lower (< 72%) than the cure rates reported for other TVT procedures; further studies are required.
Clinical comparison of primary versus secondary epilepsy in 125 cats
Authors: Pákozdy Ákos , Leschnik Michael , Sarchahi Ali Asghar , Tichy Alexander G. , Thalhammer Johann G.
Published: September 2010

In the present study 125 cats with recurrent seizures were analysed. The main goal was to investigate the aetiology and compare primary epilepsy (PE) with secondary epilepsy (SE) regarding signalment, history, ictal pattern, clinical and neurological findings. Seizure aetiology was classified as PE in 47 (38%) and SE in 78 (62%) cats. SE was caused mainly by intracranial neoplasia (16), hippocampal necrosis (14), toxicosis (eight), and encephalitis (seven). A significant difference between PE and SE was found in: age, body weight, duration of seizure, occurrence of status epilepticus and neurological deficits. Status epilepticus, altered interictal neurological status and seizure onset over the age of 7 years indicated SE more frequently than PE. If the seizures occurred during resting conditions and rapid running occurred the aetiology was more likely to be PE than SE.
Pharmacokinetics and first-pass metabolism of astaxanthin in rats
Authors: Choi Hye Duck , Kang Hee Eun , Yang Si Hyung , Lee Myung Gull , Shin Wan Gyoon
Published: September 2010

Astaxanthin is a carotenoid with antioxidant, anti-cancer and anti-inflammatory properties. The pharmacokinetics of astaxanthin after its intravenous (5, 10, and 20 mg/kg) and oral (100 and 200 mg/kg) administration and its first-pass extraction ratios after its intravenous, intraportal or intragastric (20 mg/kg) administration were evaluated in rats. The pharmacokinetic parameters of astaxanthin were dose dependent after its intravenous administration, due to the saturable hepatic metabolism of astaxanthin, but dose independent after oral administration. The gastrointestinal absorption of astaxanthin followed the flip-flop model. The hepatic and gastrointestinal first-pass extraction ratios of astaxanthin were approximately 0·490 and 0·901, respectively. Astaxanthin was metabolised primarily by hepatic cytochromeP-450 1A1/2 in rats. Astaxanthin was unstable up to 4 h incubation in four rat gastric juices and up to 24 h incubation in various buffer solutions having a pH of 1–13. The tissue/plasma ratios of astaxanthin at 8 and 24 h after its oral administration (100 mg/kg) were greater than unity for all tissues studied, except in the heart, at 8 h, indicating that the rat tissues studied had high affinity for astaxanthin.
Provenance of detrital zircons from the late Neoproterozoic to Ordovician sandstones of South China: implications for its continental affinity
Authors: WU LONG , JIA DONG , LI HAIBIN , DENG FEI , LI YIQUAN
Published: September 2010

The U–Pb geochronology of 687 detrital zircons from the voluminous Upper Neoproterozoic–Ordovician succession in the Wuyishan Fold Belt of South China reveals a common dominant c. 1200–950 Ma group, indicative of an outboard provenance terrane with a Grenville-age province to the southeast during the late Neoproterozoic–Early Palaeozoic. Compared with coeval samples from the Gondwanan and eastern Laurentian margins, our data show a scarcity of distinctive Gondwanan provenances (c. 650–500 Ma) and reveal some Laurentian signatures. These results argue against the peri-Gondwanan setting for South China during the late Neoproterozoic–Ordovician, instead implying a Laurentian affinity.
Slavery and cultural creativity in the Banda Islands
Authors: Winn Phillip
Published: September 2010

In his influential edited volume Slavery, bondage and dependency in Southeast Asia, Anthony Reid suggests that long-term slave-based systems of production were absent from agriculture in Southeast Asia, and had an ambiguous presence at best in other areas of economic activity. The argument he presents suggests that indigenous slavery in the region merged into a ‘kind of serfdom or household membership’, a situation that continued after the arrival of Europeans whose slave-holding practices were profoundly shaped by the local traditions they encountered: ‘slavery in the European colonies owed more to the Southeast Asian environment than to European legal ideas’. Reid's analysis is insightful and his conclusions persuasive. But he also notes a single exception to this general picture: ‘the Dutch perkenier system for producing nutmeg in Banda with hundreds of slave labourers on large estates’. The nutmeg estates of the Banda Islands, in eastern Indonesia, provide a rare unequivocal example of a slave mode of production in Southeast Asia, and its sole instance in an agricultural context. The islands have a similar status within established accounts of slavery in Asia more generally. While some degree of geographic and historical variation is usually acknowledged, European slavery practices in Asia are regarded as distinct from colonial slavery in the New World, where European systems were imported wholesale. Against this conclusion, the perkenier system in the Banda Islands has been described as a form of exploitation ‘unheard of in Asia’, one that represented a ‘Caribbean cuckoo in an Asian nest’. In other words, Dutch nutmeg cultivation in the Bandas constituted a New World style system of slavery operating in an Asian context.
The ‘informal Portuguese empire’ and the Topasses in the Solor archipelago and Timor in the seventeenth and eighteenth centuries
Authors: Andaya Leonard Y.
Published: September 2010

This study of Timor and the surrounding islands between the sixteenth and eighteenth centuries provides evidence that, after the demise of the Portuguese Estado da India, an ‘informal’ or ‘shadow’ empire persisted but in uniquely localised ways. It describes the emergence of the ‘black Portuguese’ community known in Timor and the Solor archipelago as the Topasses. Their singular identity was based on the melding of indigenous and Portuguese blood and cultural forms. Their ability to access the sources of spiritual authority in both the Catholic and the Timorese domains assured their survival and that of the Portuguese in Timor until well into the twentieth century.
Testimony, trauma and performance: Some examples from Southeast Asian theatre
Authors: Waterson Roxana
Published: September 2010

This paper is a reflection on a number of theatre performances held in Singapore, each of which probed problematic or traumatic historical events occurring either in Singapore itself or in other parts of Southeast Asia. These avant-garde performances were inspired by or built around actual testimonies of individuals in ways which, for this author, suggest a striking fluidity in the boundaries between testimony and performance, one that raises difficult questions about performance ethics and the processes by which collective memories are shaped. The plays also made use of visual media: one had been recorded on video while others incorporated photographic and video materials into the actual performance. At the time I witnessed these plays, I had already become interested in the way that, over the course of the twentieth century, documentary films had come to play an increasingly important role in the recording of testimony concerning traumatic events. Testimony on film, I have argued, functions simultaneously as evidential trace, and as performative event. Films of testimony develop their own trajectories as they enter into the realms of public remembering. They preserve and extend the record of personal experiences, thereby adding them to the pool of collective memory about an event. Theatrical performances, too, develop their own trajectories through repetition, as Marvin Carlson's statement (cited above) suggests. But what exactly might be different when testimony is performed as drama before a live audience? What are the purposes of such performances, and what might be their possible effects upon both participants and audiences? Is the trace left by a live theatre performance inevitably more ephemeral than those captured on film, or might it be in some respects even more powerful? These are some of the questions I raise – without necessarily being able to present definitive answers – in what follows. I conclude by arguing that in the Singapore context, because censorship laws place very specific constraints on the making of documentary films with openly political content, in recent years theatre has been able to offer a slightly greater space than film as a medium for critical reflection. How theatre directors and actors have tried to use this space is a subject correspondingly deserving of our close attention.
Die markinischen Summarien—ein literarischer und theologischer Schlüssel zu Mark 1–6
Authors: Becker Eve-Marie
Published: September 2010

On the basis of a concise definition of the literary form of a summary/Summarium/sommaire that has to be distinguished from epitome (e.g. Mk 1.14f.; 8.31) or ‘Geschichtsabriss’ (cf. Acts), this contribution analyzes the literary and theological function of all three summaries that can be found in Mark 1–6 (1.32–34; 3.7–12; 6.54–56). By these summaries the author of the Markan Gospel not only provides a macro-textual structure for his narrative, but also gives a theological interpretation and a narrative emplotment of Jesus' Galilean ministry, and thus carries forward essential parts of the Gospel story.
Spatial evolution of a q-Gaussian laser beam in relativistic plasma
Authors: Sharma A. , Kourakis I.
Published: September 2010

In a recent experimental study, the beam intensity profile of the Vulcan petawatt laser beam was measured; it was found that only 20% of the energy was contained within the full width at half maximum of 6.9 μm and 50% within 16 μm, suggesting a long-tailed non-Gaussian transverse beam profile. A q-Gaussian distribution function was suggested therein to reproduce this behavior. The spatial beam profile dynamics of a q-Gaussian laser beam propagating in relativistic plasma is investigated in this article. A non-paraxial theory is employed, taking into account nonlinearity via the relativistic decrease of the plasma frequency. We have studied analytically and numerically the dynamics of a relativistically guided beam and its dependence on the q-parameter. Numerical simulation results are shown to trace the dependence of the focusing length on the q-Gaussian profile.
A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0·5 could be a suitable global boundary value
Authors: Browning Lucy M. , Hsieh Shiun Dong , Ashwell Margaret
Published: September 2010

This systematic review collated seventy-eight studies exploring waist-to-height ratio (WHtR) and waist circumference (WC) or BMI as predictors of diabetes and CVD, published in English between 1950 and 2008. Twenty-two prospective analyses showed that WHtR and WC were significant predictors of these cardiometabolic outcomes more often than BMI, with similar OR, sometimes being significant predictors after adjustment for BMI. Observations from cross-sectional analyses, forty-four in adults, thirteen in children, supported these predictions. Receiver operator characteristic (ROC) analysis revealed mean area under ROC (AUROC) values of 0·704, 0·693 and 0·671 for WHtR, WC and BMI, respectively. Mean boundary values for WHtR, covering all cardiometabolic outcomes, from studies in fourteen different countries and including Caucasian, Asian and Central American subjects, were 0·50 for men and 0·50 for women. WHtR and WC are therefore similar predictors of diabetes and CVD, both being stronger than, and independent of, BMI. To make firmer statistical comparison, a meta-analysis is required. The AUROC analyses indicate that WHtR may be a more useful global clinical screening tool than WC, with a weighted mean boundary value of 0·5, supporting the simple public health message ‘keep your waist circumference to less than half your height’.
Migration of low‐frequency tremors revealed from multiple‐array analyses in western Shikoku, Japan
Authors: Ueno Tomotake , Maeda Takuto , Obara Kazushige , Asano Youichi , Takeda Tetsuya
Published: September 2010

Multiple‐array observation above a belt‐like tremor zone was conducted to investigate the detailed location and migration of tremor activity in western Shikoku, Japan. In March 2007, an episodic tremor and slip event occurred, and highly coherent waveforms were recorded at three arrays. Multiple signal classification analysis for the data from each array enabled measuring precise arrival directions. The majority of tremor signals suggested relatively low slowness. The arrival directions of tremor signals were used to locate tremor sources by the grid search method. Tracking the tremor activity showed that the tremor migrated within several hours in the northeast‐southwest direction over a distance of 12–15 km, and its migration velocity was 1–2.5 km h−1. This migration velocity is more rapid than the mean velocity of 0.5 km h−1 over the whole tremor episode lasting several days. Such a short‐timescale migration may represent fluctuation of slip acceleration during the slow slip event. Whenever a tremor migrates southwestward, very low frequency earthquakes occur in the vicinity of the tremor migration terminus. This indicates that the tremor migration is related to the occurrence of very low frequency earthquakes and slow slip events.
Surface reflectivity from the Ozone Monitoring Instrument using the Moderate Resolution Imaging Spectroradiometer to eliminate clouds: Effects of snow on ultraviolet and visible trace gas retrievals
Authors: O'Byrne G. , Martin R. V. , van Donkelaar A. , Joiner J. , Celarier E. A.
Published: September 2010

Satellite retrievals of tropospheric composition from measurements of solar backscatter require accurate information about surface reflectivity. We use clear‐sky data from the Ozone Monitoring Instrument (OMI) to determine global surface reflectivity under both snow‐covered and snow‐free conditions at 354 nm. Clear‐sky scenes are determined using cloud and aerosol data from the Moderate Resolution Imaging Spectroradiometer/Aqua satellite instrument that flies 12 min ahead of OMI/Aura. The result is a database of OMI‐observed Lambertian equivalent reflectivity (LER) that does not rely on statistical methods to eliminate cloud and aerosol contamination. We apply this database to evaluate previous climatologies of surface reflectivity. Except for regions of seasonal snow cover, agreement is best with a climatology from OMI, which selects the surface reflectivity from a histogram of observed LER (mean difference, 0.0002; standard deviation, 0.011). Three other climatologies of surface reflectivity from Total Ozone Mapping Spectrometer, Global Ozone Monitoring Experiment, and OMI, based on minimum observed LER, are less consistent with our cloud‐ and aerosol‐filtered data set (mean difference, −0.008, 0.012, and −0.002; standard deviation, 0.022, 0.026, and 0.033). Snow increases the sensitivity of solar backscatter measurements at ultraviolet and visible wavelengths to trace gases in the lower troposphere. However, all four existing LER climatologies poorly represent seasonal snow. Surface reflectivity over snow‐covered lands depends strongly on the vegetation type covering the surface. The monthly variation of snow‐covered reflectivity varies by less than 0.1 in fall and winter. Applying our snow‐covered surface reflectivity database to OMI NO2 retrievals could change the retrieved NO2 column by 20%–50% over large regions with seasonal snow cover.
Evaluation of Moderate Resolution Imaging Spectroradiometer land surface visible and shortwave albedo products at FLUXNET sites
Authors: Wang Kaicun , Liang Shunlin , Schaaf Crystal L. , Strahler Alan H.
Published: September 2010

We evaluated the accuracy of Moderate Resolution Imaging Spectroradiometer (MODIS) Collections 4 and 5 shortwave and visible albedo products at 18 FLUXNET sites globally from 2000 to 2007. While the shortwave product has been evaluated at a number of field sites, this represents the first attempt to assess the visible product. The surface visible albedo product relies more on quality of the atmospheric correction because atmospheric molecular scattering and aerosol absorption and scattering have larger impact on visible radiation than that on infrared radiation. The results show that in general the MODIS Collection 4 visible albedo product has an overall negative bias of −0.015, with a standard deviation (SD) error of 0.014 and a correlation coefficient of 0.88. The numbers are −0.010, 0.015, and 0.87 for Collection 5 visible albedo products. MODIS Collection 4 shortwave albedo product has an overall negative bias of −0.009, with a SD error of 0.023 and a correlation coefficient of 0.82. The numbers are −0.008, 0.023, and 0.80 for Collection 5 shortwave albedo products. A comparison of the site−averaged albedos shows that Collection 4 visible (shortwave) albedo has a SD of 0.009 (0.017) and a correlation coefficient of 0.94 (0.90), similar to the Collection 5 SD of 0.008 (0.017) and the correlation coefficient of 0.95 (0.89).
Seasonal variations of atmospheric CO2, δ13C, and δ18O at a cool temperate deciduous forest in Japan: Influence of Asian monsoon
Authors: Murayama S. , Takamura C. , Yamamoto S. , Saigusa N. , Morimoto S. , Kondo H. , Nakazawa T. , Aoki S. , Usami T. , Kondo M.
Published: September 2010

Atmospheric CO2 concentration and its isotopes have been measured at the Takayama site in central Japan since 1994, together with δ18O in precipitation since 2002, to examine their temporal variations in a cool‐temperate deciduous forest environment strongly influenced by the Asian monsoon. The CO2 concentration and δ13C at the observational site show prominent seasonal variations accompanied by a secular trend, suggesting that the average seasonal cycle is caused mainly by a seasonal‐dependent CO2 exchange with C3 plants. However, the variation in summer is found to be related to CO2 exchange with a significantly heavier δ13C signal compared to the other seasons, indicating some influence at the Takayama site of atmospheric transport of CO2 impacted by exchange with C4 plants from upstream regions. Compared with CO2 and δ13C, δ18O measurements in atmospheric CO2 are scattered, showing no clear seasonal variation. From late spring to early fall, significant year‐to‐year differences in the variation of δ18O are observed, with low and high values associated with rainy and sunny summer conditions, respectively. Comparisons with data from other northern midlatitude sites suggest that the rapid decrease of δ18O seen at Takayama in the early summer of a rainy summer year is characteristic of the Asian monsoon region. On the other hand, the characteristic increase in δ18O observed from winter to spring is likely caused by long‐range transport of air with enriched δ18O.
Comparison of parameter sensitivities between a laboratory and field‐scale model of uranium transport in a dual domain, distributed rate reactive system
Authors: Greskowiak J. , Prommer H. , Liu C. , Post V. E. A. , Ma R. , Zheng C. , Zachara J. M.
Published: September 2010

A laboratory‐derived conceptual and numerical model for U(VI) transport at the Hanford 300A site, Washington, USA, was applied to a range of field‐scale scenarios of different geochemical complexity to identify the importance of individual processes in controlling the fate of U(VI), as well as to elucidate the characteristic differences between well‐defined laboratory and the more complex field‐scale conditions. Therefore, a rigorous sensitivity analysis was carried out for the various simulation scenarios. The underlying conceptual and numerical model, originally developed from column experiment data, includes distributed rate surface complexation kinetics of U(VI), aqueous speciation, and physical nonequilibrium transport processes. The field scenarios accounted additionally for highly transient groundwater flow and variable geochemical conditions driven by frequent water level changes of the nearby Columbia River. The results of the sensitivity analysis showed not only similarities but also important differences in parameter sensitivities between the laboratory and field‐scale models. It was found that the actual degree of sorption disequilibrium, actual concentration of sorbed U(VI), and the sorption extent (i.e., theoretical concentration of sorbed U(VI) at equilibrium) are the major controls for the magnitude of the calculated parameter sensitivities. These internal model variables depended mainly on (1) the groundwater flow conditions, i.e., the relatively long phases of limited groundwater movement in the field scale (intercepted by short peak flow events) and the long sustained flow phases in the column experiment (intercepted by relatively short stop flow events), and (2) the sampling location in the field‐scale model, i.e., plume fringe versus plume center.
Differences in solar wind cross‐helicity and residual energy during the last two solar minima
Authors: Perri S. , Balogh A.
Published: September 2010

The minimum of solar cycle 23 exhibited anomalous characteristics with respect to its predecessors. Other than the differences in the standard indicators of activity, such as sunspots, polar magnetic fields were also found to be different. These differences had a range of effects in the solar wind. In this work we study the Alfvénicity and the residual energy of magnetic field fluctuations in two intervals from the solar minima in cycles 22 and 23 using Ulysses data. We find that the differences between the minima are mainly related to the greater prominence of convected structures in the broader equatorial region in cycle 23. Thus the total power in the fluctuations was lower in cycle 23, mainly due to a reduction in Alfvénic fluctuations. We also show that the relationship between the normalized residual energy and cross helicity is scale dependent.
Reconstruction and flux‐balance analysis of the Plasmodium falciparum metabolic network
Authors: Plata Germán , Hsiao Tzu‐Lin , Olszewski Kellen L , Llinás Manuel , Vitkup Dennis
Published: September 2010

Genome‐scale metabolic reconstructions can serve as important tools for hypothesis generation and high‐throughput data integration. Here, we present a metabolic network reconstruction and flux‐balance analysis (FBA) of Plasmodium falciparum, the primary agent of malaria. The compartmentalized metabolic network accounts for 1001 reactions and 616 metabolites. Enzyme–gene associations were established for 366 genes and 75% of all enzymatic reactions. Compared with other microbes, the P. falciparum metabolic network contains a relatively high number of essential genes, suggesting little redundancy of the parasite metabolism. The model was able to reproduce phenotypes of experimental gene knockout and drug inhibition assays with up to 90% accuracy. Moreover, using constraints based on gene‐expression data, the model was able to predict the direction of concentration changes for external metabolites with 70% accuracy. Using FBA of the reconstructed network, we identified 40 enzymatic drug targets (i.e. in silico essential genes), with no or very low sequence identity to human proteins. To demonstrate that the model can be used to make clinically relevant predictions, we experimentally tested one of the identified drug targets, nicotinate mononucleotide adenylyltransferase, using a recently discovered small‐molecule inhibitor.
Ectodomain shedding of the Notch ligand Jagged1 is mediated by ADAM17, but is not a lipid-raft-associated event
Authors: Parr-Sturgess Catherine A. , Rushton David J. , Parkin Edward T.
Published: September 2010

Notch signalling is an evolutionarily conserved pathway involved in cell-fate specification. The initiating event in this pathway is the binding of a Notch receptor to a DSL (Delta/Serrate/Lag-2) ligand on neighbouring cells triggering the proteolytic cleavage of Notch within its extracellular juxtamembrane region; a process known as proteolytic ‘shedding’ and catalysed by members of the ADAM (a disintegrin and metalloproteinase) family of enzymes. Jagged1 is a Notch-binding DSL ligand which is also shed by an ADAM-like activity raising the possibility of bi-directional cell–cell Notch signalling. In the present study we have unequivocally identified the sheddase responsible for shedding Jagged1 as ADAM17, the activity of which has previously been shown to be localized within specialized microdomains of the cell membrane known as ‘lipid rafts’. However, we have shown that replacing the transmembrane and cytosolic regions of Jagged1 with a GPI (glycosylphosphatidylinositol) anchor, thereby targeting the protein to lipid rafts, did not enhance its shedding. Furthermore, the Jagged1 holoprotein, its ADAM-cleaved C-terminal fragment and ADAM17 were not enriched in raft preparations devoid of contaminating non-raft proteins. We have also demonstrated that wild-type Jagged1 and a truncated polypeptide-anchored variant lacking the cytosolic domain were subject to similar constitutive and phorbol ester-regulated shedding. Collectively these data demonstrate that Jagged1 is shed by ADAM17 in a lipid-raft-independent manner, and that the cytosolic domain of the former protein is not a pre-requisite for either constitutive or regulated shedding.
MicroRNA-7 targets IGF1R (insulin-like growth factor 1 receptor) in tongue squamous cell carcinoma cells
Authors: Jiang Lu , Liu Xiqiang , Chen Zujian , Jin Yi , Heidbreder Caroline E. , Kolokythas Antonia , Wang Anxun , Dai Yang , Zhou Xiaofeng
Published: September 2010

miR-7 (microRNA-7) has been characterized as a tumour suppressor in several human cancers. It targets a number of proto-oncogenes that contribute to cell proliferation and survival. However, the mechanism(s) by which miR-7 suppresses tumorigenesis in TSCC (tongue squamous cell carcinoma) is unknown. The present bioinformatics analysis revealed that IGF1R (insulin-like growth factor 1 receptor) mRNA is a potential target for miR-7. Ectopic transfection of miR-7 led to a significant reduction in IGF1R at both the mRNA and protein levels in TSCC cells. Knockdown of miR-7 in TSCC cells enhanced IGF1R expression. Direct targeting of miR-7 to three candidate binding sequences located in the 3′-untranslated region of IGF1R mRNA was confirmed using luciferase-reporter-gene assays. The miR-7mediated down-regulation of IGF1R expression attenuated the IGF1 (insulin-like growth factor 1)-induced activation of Akt (protein kinase B) in TSCC cell lines, which in turn resulted in a reduction in cell proliferation and cell-cycle arrest, and an enhanced apoptotic rate. Taken together, the present results demonstrated that miR-7 regulates the IGF1R/Akt signalling pathway by post-transcriptional regulation of IGF1R. Our results indicate that miR-7 plays an important role in TSCC and may serve as a novel therapeutic target for TSCC patients.
The Friedreich's ataxia protein frataxin modulates DNA base excision repair in prokaryotes and mammals
Authors: Thierbach René , Drewes Gunnar , Fusser Markus , Voigt Anja , Kuhlow Doreen , Blume Urte , Schulz Tim J. , Reiche Carina , Glatt Hansruedi , Epe Bernd , Steinberg Pablo , Ristow Michael
Published: September 2010

DNA-repair mechanisms enable cells to maintain their genetic information by protecting it from mutations that may cause malignant growth. Recent evidence suggests that specific DNA-repair enzymes contain ISCs (iron–sulfur clusters). The nuclearencoded protein frataxin is essential for the mitochondrial biosynthesis of ISCs. Frataxin deficiency causes a neurodegenerative disorder named Friedreich's ataxia in humans. Various types of cancer occurring at young age are associated with this disease, and hence with frataxin deficiency. Mice carrying a hepatocyte-specific disruption of the frataxin gene develop multiple liver tumours for unresolved reasons. In the present study, we show that frataxin deficiency in murine liver is associated with increased basal levels of oxidative DNA base damage. Accordingly, eukaryotic V79 fibroblasts overexpressing human frataxin show decreased basal levels of these modifications, while prokaryotic Salmonella enterica serotype Typhimurium TA104 strains transformed with human frataxin show decreased mutation rates. The repair rates of oxidative DNA base modifications in V79 cells overexpressing frataxin were significantly higher than in control cells. Lastly, cleavage activity related to the ISC-independent repair enzyme 8-oxoguanine glycosylase was found to be unaltered by frataxin overexpression. These findings indicate that frataxin modulates DNA-repair mechanisms probably due to its impact on ISC-dependent repair proteins, linking mitochondrial dysfunction to DNA repair and tumour initiation.
Spatial epigenetics: linking nuclear structure and function in higher eukaryotes
Authors: Jackson Dean A.
Published: September 2010

Eukaryotic cells are defined by the genetic information that is stored in their DNA. To function, this genetic information must be decoded. In doing this, the information encoded in DNA is copied first into RNA, during RNA transcription. Primary RNA transcripts are generated within transcription factories, where they are also processed into mature mRNAs, which then pass to the cytoplasm. In the cytoplasm these mRNAs can finally be translated into protein in order to express the genetic information as a functional product. With only rare exceptions, the cells of an individual multicellular eukaryote contain identical genetic information. However, as different genes must be expressed in different cell types to define the structure and function of individual tissues, it is clear that mechanisms must have evolved to regulate gene expression. In higher eukaryotes, mechanisms that regulate the interaction of DNA with the sites where nuclear functions are performed provide one such layer of regulation. In this chapter, I evaluate how a detailed understanding of nuclear structure and chromatin dynamics are beginning to reveal how spatial mechanisms link chromatin structure and function. As these mechanisms operate to modulate the genetic information in DNA, the regulation of chromatin function by nuclear architecture defines the concept of ‘spatial epigenetics’.
Epigenetic markers and their cross-talk
Authors: Winter Stefan , Fischle Wolfgang
Published: September 2010

Post-translational modifications of histone proteins in conjunction with DNA methylation represent important events in the regulation of local and global genome functions. Advances in the study of these chromatin modifications established temporal and spatial co-localization of several distinct ‘marks’ on the same histone and/or the same nucleosome. Such complex modification patterns suggest the possibility of combinatorial effects. This idea was originally proposed to establish a code of histone modifications that regulates the interpretation of the genetic code of DNA. Indeed, interdependency of different modifications is now well documented in the literature. Our current understanding is that the function of a given histone modification is influenced by neighbouring or additional modifications. Such context sensitivity of the readout of a modification provides more flexible translation than would be possible if distinct modifications function as isolated units. The mechanistic principles for modification cross-talk can originate in the modulation of the activity of histone-modifying enzymes or may be due to selective recognition of these marks via modification of specific binding proteins. In the present chapter, we discuss fundamental biochemical principles of modification cross-talk and reflect on the interplay of chromatin marks in cellular signalling, cell-cycle progression and cell-fate determination.
Epigenetic dynamics across the cell cycle
Authors: Kheir Tony Bou , Lund Anders H.
Published: September 2010

Progression of the mammalian cell cycle depends on correct timing and co-ordination of a series of events, which are managed by the cellular transcriptional machinery and epigenetic mechanisms governing genome accessibility. Epigenetic chromatin modifications are dynamic across the cell cycle, and are shown to influence and be influenced by cell-cycle progression. Chromatin modifiers regulate cell-cycle progression locally by controlling the expression of individual genes and globally by controlling chromatin condensation and chromosome segregation. The cell cycle, on the other hand, ensures a correct inheritance of epigenetic chromatin modifications to daughter cells. In this chapter, we summarize the current knowledge on the dynamics of epigenetic chromatin modifications during progression of the cell cycle.
Epigenetic regulation of cell life and death decisions and deregulation in cancer
Authors: Hajji Nabil , Joseph Bertrand
Published: September 2010

For every cell, there is a time to live and a time to die. It is apparent that cell life and death decisions are taken by individual cells based on their interpretation of physiological or non-physiological stimuli, or their own self-assessment of internal damage or changes in their environment. Apoptosis or programmed cell death is a key regulator of physiological growth control and regulation of tissue homoeostasis. One of the most important advances in cancer research in recent years is the recognition that cell death, mostly by apoptosis, is crucially involved in the regulation of tumour formation and also critically determines treatment response. The initiation and progression of cancer, traditionally seen as a genetic disease, is now realized to involve epigenetic abnormalities along with genetic alterations. The study of epigenetic mechanisms in cancer, such as DNA methylation, histone modifications and microRNA expression, has revealed a plethora of events that contribute to the neoplastic phenotype through stable changes in the expression of genes critical to cell death pathways. A better understanding of the epigenetic molecular events that regulate apoptosis, together with the reversible nature of epigenetic aberrations, should contribute to the emergence of the promising field of epigenetic therapy.
Dynamics of telomeric chromatin at the crossroads of aging and cancer
Authors: Ye Jing , Wu Yunlin , Gilson Eric
Published: September 2010

Telomeres are nucleoprotein structures that protect the ends of human chromosomes through the formation of a ‘cap’, thus preventing exonucleolytic degradation, inter- and intra-chromosomal fusion, and subsequent chromosomal instability. During aging, telomere shortening correlates with tissue dysfunction and loss of renewal capacity. In human cancer, telomere dysfunction is involved in early chromosome instability, long-term cellular proliferation, and possibly other processes related to cell survival and microenvironment. Telomeres constitute an attractive target for the development of novel small-molecule anti-cancer drugs. In particular, individual protein components of the core telomere higher-order chromatin structure (known as the telosome or ‘shelterin’ complex) are promising candidate targets for cancer therapy.
Epigenetic regulation of genes in learning and memory
Authors: Roth Tania L. , Roth Eric D. , Sweatt J. David
Published: September 2010

Rapid advances in the field of epigenetics are revealing a new way to understand how we can form and store strong memories of significant events in our lives. Epigenetic modifications of chromatin, namely the post-translational modifications of nuclear proteins and covalent modification of DNA that regulate gene activity in the CNS (central nervous system), continue to be recognized for their pivotal role in synaptic plasticity and memory formation. At the same time, studies are correlating aberrant epigenetic regulation of gene activity with cognitive dysfunction prevalent in CNS disorders and disease. Epigenetic research, then, offers not only a novel approach to understanding the molecular transcriptional mechanisms underlying experience-induced changes in neural function and behaviour, but potential therapeutic treatments aimed at alleviating cognitive dysfunction. In this chapter, we discuss data regarding epigenetic marking of genes in adult learning and memory formation and impairment thereof, as well as data showcasing the promise for manipulating the epigenome in restoring memory capacity.