bluuebunny/crossref_metadata_2025 huggingface dataset:
Biodiesel Production from Soybean Oil Catalyzed by Li2CO3
Authors: Wang J. X. , Chen K. T. , Huang S. T. , Chen K. T. , Chen C. C.
Published: May 2012

In the present study, we synthesized biodiesel from soybean oil through a transesterification reaction catalyzed by lithium carbonate. Under the optimal reaction conditions of methanol/oil molar ratio 32:1, 12 % (wt/wt oil) catalyst amount, and a reaction temperature of 65 °C for 2 h, there was a 97.2 % conversion to biodiesel from soybean oil. The present study also evaluated the effects of methanol/oil ratio, catalyst amount, and reaction time on conversion. The catalytic activity of solid base catalysts was insensitive to exposure to air prior to use in the transesterification reaction. Results from ICP‐OES exhibited non‐significant leaching of the Li2CO3 active species into the reaction medium, and reusability of the catalyst was tested successfully in ten subsequent cycles. Free fatty acid in the feedstock for biodiesel production should not be higher than 0.12 % to afford a product that passes the EN biodiesel standard. Product quality, ester content, free glycerol, total glycerol, density, flash point, sulfur content, kinematic viscosity, copper corrosion, cetane number, iodine value, and acid value fulfilled ASTM and EN standards. Commercially available Li2CO3 is suitable for direct use in biodiesel production without further drying or thermal pretreatment, avoiding the usual solid catalyst need for activation at high temperature.
The Significance of Education for Mortality Compression in the United States
Authors: Brown Dustin C. , Hayward Mark D. , Montez Jennifer Karas , Hummer Robert A. , Chiu Chi-Tsun , Hidajat Mira M.
Published: May 2012

Recent studies of old-age mortality trends assess whether longevity improvements over time are linked to increasing compression of mortality at advanced ages. The historical backdrop of these studies is the long-term improvement in a population’s socioeconomic resources that fueled longevity gains. We extend this line of inquiry by examining whether socioeconomic differences in longevity within a population are accompanied by old-age mortality compression. Specifically, we document educational differences in longevity and mortality compression for older men and women in the United States. Drawing on the fundamental cause of disease framework, we hypothesize that both longevity and compression increase with higher levels of education and that women with the highest levels of education will exhibit the greatest degree of longevity and compression. Results based on the Health and Retirement Study and the National Health Interview Survey Linked Mortality File confirm a strong educational gradient in both longevity and mortality compression. We also find that mortality is more compressed within educational groups among women than men. The results suggest that educational attainment in the United States maximizes life chances by delaying the biological aging process.
BMP signaling in vascular diseases
Authors: Cai Jie , Pardali Evangelia , Sánchez-Duffhues Gonzalo , ten Dijke Peter
Published: May 2012

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor‐β (TGF‐β) family that signal via type I and type II serine/threonine kinase receptors and intracellular Smad transcription factors. BMPs are multifunctional regulators of development and tissue homeostasis and they were initially characterized as inducers of bone regeneration. Genetic studies in humans and mice showed that perturbations in BMP signaling lead to various diseases, such as skeletal diseases, vascular diseases and cancer. Mutations in BMP type II receptor and BMP type I receptor/activin receptor‐like kinase 1 have been linked to pulmonary arterial hypertension and hereditary hemorrhagic telangiectasia, respectively. BMPs have also been implicated in promoting vascular calcification and tumor angiogenesis. In this review we discuss the role of BMP signaling in vascular diseases and the value of BMP signaling as a vascular disease marker or a therapeutic target.
Conformational changes upon ligand binding in the essential class II fumarase Rv1098c from Mycobacterium tuberculosis
Authors: Mechaly Ariel E. , Haouz Ahmed , Miras Isabelle , Barilone Nathalie , Weber Patrick , Shepard William , Alzari Pedro M. , Bellinzoni Marco
Published: May 2012

Rv1098c and Rv1098c bind by X‐ray crystallography (View interaction)
The bromodomain interaction module
Authors: Filippakopoulos Panagis , Knapp Stefan
Published: May 2012

ε‐N‐acetylation of lysine residues (Kac) is one of the most abundant post‐translation modifications (PTMs) in the human proteome. In the nucleus, acetylation of histones has been linked to transcriptional activation of genes but the functional consequences of most acetylation events and proteins recruited to these sites remains largely unknown. Bromodomains (BRDs) are small helical interaction modules that specifically recognize acetylation sites in proteins. BRDs have recently emerged as interesting targets for the development of specific protein interaction inhibitors, enabling a novel exiting strategy for the development of new therapies. This review provides an overview over sequence requirements of BRDs, known substrates and the structural mechanisms of specific Kac recognition.
When policy makers consult professional groups in public policy formation: Transversal consultation in the Belgian Mental Health Sector
Authors: Thunus Sophie , Schoenaers Frederic
Published: May 2012

This contribution focuses on a policy consultation process: the “transversal consultation”. Launched in 2007 in the Belgian Mental Health Sector, this consultation had to capture the experience-based knowledge of service users and professionals involved in local projects aimed at experimenting working conditions in mental health care networks. This policy challenges the existing hospital-centred model of care, characterized by a medical approach and professional specialization, by promoting instead a pluridisciplinary approach in mental health care networks.

In this contribution, a case of this transversal consultation process is analysed by relying on a theoretical framework drawn from the Sociology of Organizations and the Sociology of Public Action. The analysis emphasizes the strategic use that is made of the consultation process, and stresses the gap observed between its formal objective and its perceived outcome: more than producing experience-based knowledge about mental health care networks, the transversal consultation challenged power relations sustaining the current organization of the mental health system. It shortly discusses, as a conclusion, the outcome of the initiative.
De facto states and democracy: The case of Nagorno-Karabakh
Authors: Kolstø Pål , Blakkisrud Helge
Published: May 2012

De facto states are often dismissed as ‘failing states’. However, in Freedom House rankings of political rights and civil liberties, they sometimes perform better than their parent states – as has been the case with Nagorno-Karabakh. This article examines the development of democracy in Nagorno-Karabakh against a checklist of factors assumed to be relevant: cultural homogeneity, size, existential threats, role of the diaspora, and the consequences of continued non-recognition. Drawing on fieldwork and interviews with central actors, the authors conclude that, contrary to what might be expected, non-recognition has played a main role in the democratization process.
Post-Soviet de facto states in search of internal and external legitimacy. Introduction.
Authors: von Steinsdorff Silvia , Fruhstorfer Anna
Published: May 2012

The four state-like entities on the territory of the former Soviet Union that emerged about twenty years ago have successfully defended their precarious independence until today. However, we still know very little about the internal political developments in these de facto states, because so far most research has focused on the regional and international dimensions of the now “frozen” secessionist conflicts which brought them into being. The authors of this issue argue that it is high time to have a closer look at the developments inside these de facto states for several reasons. First, in order to understand whether there is mutual dependence between internal political structures and processes and the chances of international recognition. Second, the post-Soviet de facto states are model cases for internal transformation or even democratization efforts as a strategy of internal and/or external legitimacy building. Finally, the issue proves that the reluctance of academia to analyze the political systems of these entities for fear of legitimizing regimes that do not deserve it is not reasonable: the post-Soviet de facto states are fully grown states for all but international recognition – they are not supposed to disappear because we refuse to admit this fact.
Interaction with substrate sensitises caspase‐3 to inactivation by hydrogen peroxide
Authors: Hampton Mark B , Stamenkovic Ivan , Winterbourn Christine C
Published: May 2012

Caspases have an active site cysteine whose oxidation blocks catalytic activity. Caspase activity, measured in lysates of apoptotic cells, was inhibited by H2O2 with an IC50 of 7 μM. Recombinant caspase‐3 was directly inhibited by H2O2, with an estimated second‐order rate constant of 750 M−1 s−1. These values were determined when H2O2 was added while the caspases were cleaving a peptide substrate. There was a 40‐fold decrease in sensitivity to inactivation if the substrate was absent at the time of H2O2 addition. These results rationalise conflicting reports of the sensitivity of caspase‐3 to H2O2, and identify a novel mechanism for sensitising a thiol enzyme to oxidative inactivation.
Electrical and spectral property of cold arc plasma at atmospheric pressure
Authors: ZHONG-CAI YUAN , JIA-MING SHI , ZONG-SHENG CHEN , BO XU
Published: May 2012

An atmospheric pressure plasma jet is generated with a cold arc discharge in ambient air. The current-voltage characteristics and optical emission spectra of plasma discharges are investigated. The molecular nitrogen (N2), hydroxyl radical (OH), and oxygen atom (O) are observed and analyzed. Based on the best fit of the simulated spectra of N2 (C3∏u+ − B3∏g+) band and OH (A2∑+ − X2∏) band transition and the experimentally recorded spectra, the rotational temperature and the vibrational temperature of atmospheric pressure cold arc plasma jet (APCAPJ) are estimated.
Multi-disciplinarity, user engagement and the design of special programmes of ageing research in the United Kingdom
Authors: LANSLEY PETER
Published: May 2012

Since 1997 ageing research in the United Kingdom (UK) has been promoted through a series of research council special programmes with an emphasis on multi-disciplinary, collaborative, user-focused research. There has been notable progress and substantial setbacks, especially a major lull in activity, and strong disciplinary biases in later programmes. Skills, expertise and influence on policy and practice, developed through early programmes, have been lost. Two philosophies of programme management have emerged: a top-down approach to the development of priorities and activities, largely reflecting a linear model of research, development and diffusion; and, a bottom-up approach strongly influenced by the priorities of users including older people, which has emphasised the role of problem-solving and social interaction between researchers and users. A comparison of these two philosophies highlights factors which contribute to successful programme implementation and valuable outcomes for society at large. These emphasise: involvement of all potential users; encouragement of champions; supporting researchers at all stages in their careers; transparency in communicating intent, progress and achievements; varied and robust knowledge transfer; and, above all else, understanding the challenges faced by individuals as they grow older. Future programmes would be assured of making significant contributions to supporting older people and an ageing society if those commissioning the programmes recognised the importance of these factors and accepted the consequent challenges for the organisation of the programmes.
Editorial: Aesthetics, Politics and the Public Sphere
Authors: ASTON ELAINE
Published: May 2012

Aesthetics. Politics. The Public Sphere. These emerge as connective headlines in this edition of TRI. Taken as a whole, the articles provoke key critical questions about the choice of aesthetics in relation to the potentiality of theatre's transformative capacities, and also about how the possibilities (and limitations) of the transformational power that theatre is commonly deemed to be capable of are conditioned by the kind of role theatre and performance have or are permitted to have in the public sphere.
I want to be the Palestinian Romeo!Arna's Childrenand the Romance with Theatre
Authors: FISEK EMINE
Published: May 2012

This article focuses onArna's Children, a 2004 documentary about the children's activities and theatre group founded in 1989 by Israeli activist Arna Mer Khamis in the Jenin Refugee Camp of the occupied West Bank. While the documentary provides an in-depth look at how theatrical practices can prove restorative in the face of destruction, my discussion suggests that its portrayal of the aesthetic medium also interrogates the limits of the relationship between theatrical practice and emancipatory ideals.
De-monopolizing the Public Sphere: Politics and Theatre in Nineteenth-Century Germany
Authors: WAGNER MEIKE
Published: May 2012

This article focuses on an incident of censorship and police intervention at the Königstädtische Theater in Berlin in 1828, occasioned by a performance of Gotthilf August von Maltitz'sThe Old Student(Der alte Student). Identifying how the playwright and his actors sought to represent political topics onstage allows me to explore how theatre functioned as a potential player in an incipient public sphere. In turn this reveals how the desire to represent political topics onstage and to become a performative player in the public sphere was already under way in the 1820s, well before the revolutionary turbulence of 1848.
Dossier: History, Memory, Event: A Working Archive
Authors: ANAN NOBUKO , DUTT BISHNUPRIYA , REINELT JANELLE , SAHAI SHRINKHLA
Published: May 2012

This dossier documents a research collaboration between members of the School of Art and Aesthetics at Jawaharlal Nehru University in Delhi, India, and members of the School of Theatre, Performance and Cultural Policy Studies at the University of Warwick, in Coventry, United Kingdom, between 2008 and 2010. This collaboration was dedicated to a cross-cultural inquiry into methods and topics of performance research that might serve to produce a robust international dialogue capable of approaching performance through multinational lines of inquiry. Participants chose a common topic (History, Memory, Event, and the Politics of Performance 1970–1990), and composed an archive of materials drawn from six nations which was analysed and interrogated by the group. The dossier offers examples from the archive and an account of the way the group processed these artefacts.
Strangling blondes: nineteenth-century femininity and Korngold's Die tote Stadt
Authors: Winters Ben
Published: May 2012

Responses to Korngold's 1920 opera Die tote Stadt have long been filtered through the lens of his later Hollywood career. To do so, however, not only risks misunderstanding the relationship between these two different spheres of the composer's output, but also ignores the opera's complex positioning within the gender discourses of early twentieth-century Vienna. This article offers a corrective to the clichéd view of Korngold the ‘pre-filmic’ opera composer by arguing that, in its treatment of the characters Marie and Marietta, Die tote Stadt draws on a tradition of ‘strangling blonde’ imagery from the nineteenth century in order to critique the gender theories of Otto Weininger (1880–1903), which were still current in the 1920s. As such, in its concern with the nature of femininity, Die tote Stadt also draws our attention to the modern woman who had just entered the composer's life, Luise (Luzi) von Sonnenthal.
Caroline Carvalho and nineteenth-century coloratura
Authors: Parr Sean M.
Published: May 2012

This essay explores how the soprano Caroline Carvalho (néeMarie Félix-Miolan, 1827–95) perpetuated and extended the art of coloratura singing in the mid-nineteenth century. Creator of roles in sixteen operas, including five by Gounod, Carvalho achieved ‘superdiva’ status (Rutherford) by cultivating her voice – her ‘mécanisme prodigieux’ – to handle coloratura on a scale that explicitly invoked and rivalled the instrumental virtuosity of Paganini. In premièring the title role of Victor Massé'sLa Reine Topaze(1856), the soprano sang a variations aria based on the Carnival of Venice folk song and took one of the violinist's variations as a springboard to her own dazzling pyrotechnics. By allying her voice with the musical inventiveness of Paganini, who had achieved deific renown and artistic authority, Carvalho thereby acquired enough authority to catalyse a new genre, thevalse-ariette. The popularity of a little-known aria that Gounod arranged for Carvalho, ‘Ah! Valse légère’ (based on the waltz chorus, ‘Ainsi que la brise légère’, from Act II ofFaust, 1859), spurred a vogue for vertiginous waltz ariettes. Carvalho's association with this genre suggests even greater creative agency and indicates a shift in coloratura's signification from instrumentality to dance and the expressive body.
Nanoprobe Fourier-Transform Photoabsorption Spectroscopy Using a Supercontinuum Light Source
Authors: Ishibe Kiyoshiro , Nakada Satoru , Mera Yutaka , Maeda Koji
Published: May 2012

A scheme of photoabsorption spectroscopy based on scanning tunneling microscopy (STM) has been developed by using a supercontinuum light as the wideband light source of a Fourier transform interferometer for spectroscopic measurements. The performance was demonstrated for a sample of GaAs. The proof-of-concept test showed that the use of the supercontinuum light instead of halogen lamps greatly enhances the signal-to-noise ratio due to the high brilliance of the supercontinuum light emitted from a small core of the photonic crystal fiber that enables tight focusing of the spectroscopy light onto the sample beneath the STM tip.
Serotonin2C ligands exhibiting full negative and positive intrinsic activity elicit purposeless oral movements in rats: distinct effects of agonists and inverse agonists in a rat model of Parkinson's disease
Authors: Navailles Sylvia , Lagière Mélanie , Roumegous Audrey , Polito Marina , Boujema Méric B. , Cador Martine , Dunlop John , Chesselet Marie-Françoise , Millan Mark J. , De Deurwaerdère Philippe
Published: May 2012

This study examined in naive or hemiparkinsonian rats the effect of various serotonin 2C (5-HT2C) receptor ligands differing in their intrinsic activity at 5-HT2C receptors on purposeless oral movements, a motor response integrated in the basal ganglia. Intraperitoneal administration of a non-selective [meta-chlorophenylpiperazine (m-CPP) 0.1–3 mg/kg], preferential [S-2-(6-chloro-5-fluoroindol-1-yl)-1-methylethylamine, Ro60-0175, 0.1–3 mg/kg] or selective [(7bR,10aR)-1,2,3,4,8,9,10,10a-octahydro-7bH-cyclopenta-[b][1,4]diazepino[6,7,1hi]indole, WAY163909, 0.3–10 mg/kg] 5-HT2C agonists enhanced oral bouts in naive rats. The 5-HT2C inverse agonists SB206553 [1–20 mg/kg; 5-methyl-1-(3-pyridylcarbamoyl)-1,2,3,5-tetrahydropyrrolo[2,3-f]indole] and S32006 [1–20 mg/kg; N-pyridin-3-yl-1,2-dihydro-3H-benzo[e]indole-3-carboxamide], but not the 5-HT2C antagonist SB243213 [1–10 mg/kg; 5-methyl-1-[[2-[(2-methyl-3-pyridyl)oxy]-5-pyridyl]carbamoyl]-6-trifluoromethylindoline], likewise dose-dependently enhanced oral movements. The effects induced by preferential 5-HT2C agonists and inverse agonists, but not by the cholinomimetic drug pilocarpine (5 mg/kg), were abolished by SB243213 underpinning its specificity. S32006-induced oral bouts was unaffected by the 5,7-dihydroxytryptamine lesions of 5-HT neurons. Nigrostriatal dopaminergic lesions potentiated oral effects induced by the agonists Ro60-0175 (3 mg/kg) and WAY163909 (1 mg/kg), but not by the inverse agonist SB206553 (10 mg/kg). The effect of Ro60-0175 in dopamine-lesioned rats was suppressed by SB243213. These data show that 5-HT2C agonists and full inverse agonists (but not neutral antagonists) perturb oral activity in rodents, paralleling studies of common antidepressant, anxiolytic and antipsychotic properties. The differential sensitivity of their actions to depletion of dopamine suggests recruitment of different contrasting neural mechanisms in the basal ganglia.
Resolving Low-Contrast Microstructure Using Transmitted and Reflected Circular Oblique Lighting (COL)
Authors: Clarke Ted
Published: May 2012

A little-known illumination method for light microscopy goes by several names, the most prominent being “circular oblique lighting” (COL) and “hollow-cone illumination”. Matthews notes that hollow-cone or annular bright field illumination can give contrast and resolution superior to that obtainable with narrow-pencil illumination and under favorable conditions comparable to that obtained with phase optics. He demonstrates this with photomicrographs of the same unstained epithelial cell from the mouth mounted in saliva, imaged with a 0.65 numerical aperture (NA) 40× objective. Matthews also notes that the dot pattern of Pleurosigmaangulatum can be resolved with a 0.50 NA objective using circular oblique lighting. Leitz previously marketed the Heine illuminator for transmitted annular (hollow cone) illumination. The NA of the Heine condenser's annular illumination can be adjusted to match the phase annuli in phase contrast objectives. The NA can be increased to provide dark field illumination or circular oblique illumination in bright field. The instructions for the Heine condenser call for the annular illumination just falling within the NA of the objective, what Paul James calls COL and Frithjof A. S. Sterrenberg calls extreme annular illumination, “bright field with very rich contrast.” H. J. Dethloff published a more recent article describing the need for the increased contrast of hollow cone bright field to help resolve the striae of pores in the diatom Amplipleurapellucida. This diatom has been the traditional test of the resolution limit of the light microscope; it is considered a low-contrast subject because the visibility of pores in the transparent amorphous silica frustules is determined by the refractive index difference between the mountant and the frustules. The low contrast makes this a challenging, perhaps even unsuitable, test object for resolution. Resolution tests of modern objectives are done with high-contrast but costly patterns of chrome on glass obtained by electron lithography.
Memory Storage with a Few Atoms
Authors: Carmichael Stephen W.
Published: May 2012

High-density magnetic memory is typically fabricated from ferromagnetic materials. As the density is increased and the memory elements are more densely packed, the magnetic fields of neighboring elements interfere with each other. If materials without magnetic fields, referred to as antiferromagnetic, could be manipulated to store data, such limitations theoretically could be overcome. In a breakthrough study, Sebastian Loth, Susanne Baumann, Christopher Lutz, Don Eigler, and Andreas Heinrich used a low-temperature scanning tunneling microscope (STM) to assemble a device with just 12 antiferromagnetic atoms that could be manipulated to one of two states, demonstrating the ability to store data. Until now, about one million atoms have been required to store a digital 0 or 1 in the most advanced magnetic storage systems.
Organic Materials and Organic/Inorganic Heterostructures in Atom Probe Tomography
Authors: Joester Derk , Hillier Andrew , Zhang Yi , Prosa Ty J.
Published: May 2012

Nano-scale organic/inorganic interfaces are key to a wide range of materials. In many biominerals, for instance bone or teeth, outstanding fracture toughness and wear resistance can be attributed to buried organic/inorganic interfaces. Organic/inorganic interfaces at very small length scales are becoming increasingly important also in nano and electronic materials. For example, functionalized inorganic nanomaterials have great potential in biomedicine or sensing applications. Thin organic films are used to increase the conductivity of LiFePO4 electrodes in lithium ion batteries, and solid electrode interphases (SEI) form by uncontrolled electrolyte decomposition. Organics play a key role in dye-sensitized solar cells, organic photovoltaics, and nano-dielectrics for organic field-effect transistors. The interface between oxide semiconductors and polymer substrates is critical in emergent applications, for example, flexible displays.
Calendar
Authors: Webster Paul
Published: May 2012

Following is a list of microscopy related meetings and courses. The editors would greatly appreciate input to this list via the electronic submission form under “events/other microscopy events” at the MSA webpage: www.microscopy.org. We will gladly add hypertext links to the notice on the web and insert a listing of the meeting in the next issue.
Long‐term change of the Pacific North Equatorial Current bifurcation in SODA
Authors: Chen Zhaohui , Wu Lixin
Published: May 2012

The long‐term change of the North Equatorial Current (NEC) bifurcation in the Pacific Ocean is assessed based on the recently developed Simple Ocean Data Assimilation (SODA, version 2.2.4). It is found that the NEC bifurcation latitude (NBL) has shifted southward over the past 60 years, although it displayed a slight northward migration from 1970 to 1992. This southward shift of the bifurcation latitude is associated with changes in the wind stress curl over the tropical Pacific Ocean between 10°N and 20°N, leading to the strengthening of the Kuroshio at its origin. The conclusion is further supported by simulations of Intergovernmental Panel on Climate Change models. It is demonstrated that the long‐term change of the seasonal south–north migration of the bifurcation is modulated by the southward shift of the mean position. Over the past 6 decades, the phase speed of first‐mode baroclinic Rossby waves (CR) at the latitude of the bifurcation increases from 13 cm s−1 in 1950 to 18 cm s−1 in 2005, and the corresponding seasonal amplitude increases (decreases) before (after) the mid‐1980s. Using a linear vorticity model, it is found that the long‐term modulation of the NBL seasonal migration amplitude is associated with the increase of CR in responses to the southward shift of the mean NBL. It is expected that the seasonal amplitude will decrease moderately in the following decades if the ocean continues warming.
Influence of a large fluvial island, streambed, and stream bank on surface water‐groundwater fluxes and water table dynamics
Authors: Shope Christopher L. , Constantz James E. , Cooper Clay A. , Reeves Donald M. , Pohll Greg , McKay W. Alan
Published: May 2012

Substantial research on how hydraulic and geomorphologic factors control hyporheic exchange has resulted in reasonable process understanding; however, the role of fluvial islands on the transient nature of spatial flux patterns remains elusive. We used detailed field observations of the Truckee River, Nevada from 2003 to 2009 to quantify fluid flux between the river and a fluvial island, the streambed, and the adjacent stream bank. We constructed a 3‐D numerical flow and heat transport model to further quantify the complex flow paths. Our study expands on previous research typically confined to less comprehensive scales and dimensions, and highlights the transient multidimensionality of the flow field. In fact, 1‐D vertical streambed flux estimates indicated that the channel bar tail displayed the highest upward flux throughout the summer; however, 3‐D model results indicated that the horizontal contribution was two orders of magnitude higher than the vertical contribution. The channel bar net flux is typically 1.5 orders of magnitude greater than the adjacent stream banks and an order of magnitude less than net streambed fluxes, indicating significant differences in river‐aquifer interactions between each of the geomorphic units. Modeling simulations further indicated that the channel bar induces 6 times more fluid flux than an identical location without a fluvial island, consistent with flux estimates from a nearby river restoration location. Moreover, event‐based and seasonal transient antecedent moisture and near‐stream storage conditions contribute to multidimensional river‐groundwater interactions. These results suggest that fluvial islands are a key driver and significant component of river‐groundwater interactions and hyporheic flow.
Peptidylarginine deiminase modulates the physiological roles of enolase via citrullination: links between altered multifunction of enolase and neurodegenerative diseases
Authors: Jang Byungki , Jeon Yong-Chul , Choi Jin-Kyu , Park Mira , Kim Jae-Il , Ishigami Akihito , Maruyama Naoki , Carp Richard I. , Kim Yong-Sun , Choi Eun-Kyoung
Published: May 2012

The citrullination of enolase by PAD (peptidylarginine deiminase) has emerged as an important post-translational modification in human disorders; however, the physiological function of citrullination remains unknown. In the present study, we report that citrullination diversely regulates the biological functions of ENO1 (α-enolase) and NSE (neuron-specific enolase). We developed three mouse IgG1 monoclonal antibodies with specificity to the following: (i) citrullination of Arg9 of ENO1 [ENO1Cit9; anti-CE1 (citrullinated enolase 1) antibody]; (ii) citrullination of Arg9 in ENO1 and NSE (ENO1Cit9/NSECit9; anti-CE1/2 antibody); and (iii) citrullination of Arg429 of NSE (NSECit429; anti-CE2 antibody). Regardless of the total protein expression level, the levels of ENO1Cit9 and NSECit429 were elevated, and their immunoreactivities were also increased in cortical neuronal cells or around blood vessels in the frontal cortex of patients with sporadic Creutzfeldt-Jakob disease and Alzheimer's disease compared with controls. In a time- and dose-dependent manner, PAD negatively regulated enolase activity via citrullination, and enolase in diseased patients was more inactive than in controls. Interestingly, the citrullination of enolase effectively promoted its proteolytic degradation by Ca2+-dependent calpain-1, and leupeptin (calpain inhibitor I) abrogated this degradation. Surprisingly, using an affinity assay, the citrullination of enolase enhanced its plasminogen-binding affinity, which was blocked by the lysine analogue ϵ-aminocaproic acid. These findings suggest that PAD-mediated citrullination regulates the diverse physiological activities of enolase and that CE may be a candidate diagnostic/prognostic factor for degenerative diseases.
Kinesin motors and primary cilia
Authors: Verhey Kristen J. , Dishinger John , Kee Hooi Lynn
Published: May 2012

Cilia and flagella play important roles in human health by contributing to cellular motility as well as sensing and responding to environmental cues. Defects in ciliary assembly and/or function can lead to a range of human diseases, collectively known as the ciliopathies, including polycystic kidney, liver and pancreatic diseases, sterility, obesity, situs inversus, hydrocephalus and retinal degeneration. A basic understanding of how cilia form and function is essential for deciphering ciliopathies and generating therapeutic treatments. The cilium is a unique compartment that contains a distinct complement of protein and lipid. However, the molecular mechanisms by which soluble and membrane protein components are targeted to and trafficked into the cilium are not well understood. Cilia are generated and maintained by IFT (intraflagellar transport) in which IFT cargoes are transported along axonemal microtubules by kinesin and dynein motors. A variety of genetic, biochemical and cell biological approaches has established the heterotrimeric kinesin-2 motor as the ‘core’ IFT motor, whereas other members of the kinesin-2, kinesin-3 and kinesin-4 families function as ‘accessory’ motors for the transport of specific cargoes in diverse cell types. Motors of the kinesin-9 and kinesin-13 families play a non-IFT role in regulating ciliary beating or axonemal length, respectively. Entry of kinesin motors and their cargoes into the ciliary compartment requires components of the nuclear import machinery, specifically importin-β2 (transportin-1) and Ran-GTP (Ran bound to GTP), suggesting that similar mechanisms may regulate entry into the nuclear and ciliary compartments.
Bidirectional intracellular transport: utility and mechanism
Authors: Jolly Amber L. , Gelfand Vladimir I.
Published: May 2012

Bidirectional transport of intracellular cargo along microtubule tracks is the subject of intense debate in the motility field. In the present review, we provide an overview of the models describing the possible mechanisms driving intracellular saltatory transport, taking into account current experimental results that may at first seem contradictory. We examine the phenomenon of saltatory motion, in an attempt to interpret the mechanistic debate in terms of the utility of saltatory motion.
Coiled coils and SAH domains in cytoskeletal molecular motors
Authors: Peckham Michelle
Published: May 2012

Cytoskeletal motors include myosins, kinesins and dyneins. Myosins move along tracks of actin filaments, whereas kinesins and dyneins move along microtubules. Many of these motors are involved in trafficking cargo in cells. However, myosins are mostly monomeric, whereas kinesins are mostly dimeric, owing to the presence of a coiled coil. Some myosins (myosins 6, 7 and 10) contain an SAH (single α-helical) domain, which was originally thought to be a coiled coil. These myosins are now known to be monomers, not dimers. The differences between SAH domains and coiled coils are described and the potential roles of SAH domains in molecular motors are discussed.
Cellular functions of class IX myosins in epithelia and immune cells
Authors: Bähler Martin , Elfrink Kerstin , Hanley Peter J. , Thelen Sabine , Xu Yan
Published: May 2012

Mammals contain two class IX myosins, Myo9a and Myo9b. They are actin-based motorized signalling molecules that negatively regulate RhoA signalling. Myo9a has been implicated in the regulation of epithelial cell morphology and differentiation, whereas Myo9b has been shown to play an important role in the regulation of macrophage shape and motility.
Microtubule-based motor-mediated mRNA localization in Drosophila oocytes and embryos
Authors: Gaspar Imre
Published: May 2012

RNA localization coupled to translational repression is a general mechanism for creating structural and functional asymmetry within the cell. While there are many possible ways to target an mRNA to its destination, a large fraction of the studied transcripts undertake active transport mediated by cytoskeletal elements (microtubules and actin filaments) and associated mechanoenzymes. Among the best-studied model systems of RNA localization are the oocyte and the early embryo of Drosophila melanogaster, for which many well-characterized tools have been developed to study this cell biological phenomenon in a dynamic, developing system in its in vivo context. In the present paper, we review the current evidence and models explaining the different modes of RNA localization that depend on active transport within cells.
Analysis of radicals and radical reaction products in cell signalling and biomolecular damage: the long hard road to gold-standard measures
Authors: Winyard Paul G. , Spickett Corinne M. , Griffiths Helen R.
Published: May 2012

The field of free radical biology and medicine continues to move at a tremendous pace, with a constant flow of ground-breaking discoveries. The following collection of papers in this issue of Biochemical Society Transactions highlights several key areas of topical interest, including the crucial role of validated measurements of radicals and reactive oxygen species in underpinning nearly all research in the field, the important advances being made as a result of the overlap of free radical research with the reinvigorated field of lipidomics (driven in part by innovations in MS-based analysis), the acceleration of new insights into the role of oxidative protein modifications (particularly to cysteine residues) in modulating cell signalling, and the effects of free radicals on the functions of mitochondria, extracellular matrix and the immune system. In the present article, we provide a brief overview of these research areas, but, throughout this discussion, it must be remembered that it is the availability of reliable analytical methodologies that will be a key factor in facilitating continuing developments in this exciting research area.
Lipidomics of polyunsaturated-fatty-acid-derived oxygenated metabolites
Authors: Massey Karen A. , Nicolaou Anna
Published: May 2012

Nutritionally important PUFAs (polyunsaturated fatty acids) mediate some of their bioactivities through formation of oxygenated metabolites. These bioactive lipids are formed by COX (cyclo-oxygenase), LOX (lipoxygenase) and cytochrome-P450-catalysed reactions, as well as non-enzymatic lipid peroxidation. These reactions produce numerous species, some of which can be formed through more than one pathway. MS-based lipidomics offers the selectivity and sensitivity required for qualitative and quantitative analysis of multiple lipid species, in a variety of biological systems, and can facilitate the study of these mediators.
Spectroscopic analysis of protein Fe–NO complexes
Authors: Bellota-Antón César , Munnoch John , Robb Kirsty , Adamczyk Katrin , Candelaresi Marco , Parker Anthony W. , Dixon Ray , Hutchings Matthew I. , Hunt Neil T. , Tucker Nicholas P.
Published: May 2012

The toxic free radical NO (nitric oxide) has diverse biological roles in eukaryotes and bacteria, being involved in signalling, vasodilation, blood clotting and immunity, and as an intermediate in microbial denitrification. The predominant biological mechanism of detecting NO is through the formation of iron nitrosyl complexes, although this is a deleterious process for other iron-containing enzymes. We have previously applied techniques such as UV–visible and EPR spectroscopy to the analysis of protein Fe–NO complex formation in order to study how NO controls the activity of the bacterial transcriptional regulators NorR and NsrR. These studies have analysed NO-dependent biological activity both in vitro and in vivo using diverse biochemical, molecular and spectroscopic methods. Recently, we have applied ultrafast 2D-IR (two-dimensional IR) spectroscopy to the analysis of NO–protein interactions using Mb (myoglobin) and Cc (cytochrome c) as model haem proteins. The ultrafast fluctuations of Cc and Mb show marked differences, indicating altered flexibility of the haem pockets. We have extended this analysis to bacterial catalase enzymes that are known to play a role in the nitrosative stress response by detoxifying peroxynitrite. The first 2D-IR analysis of haem nitrosylation and perspectives for the future are discussed.
Measurement of exercise-induced oxidative stress in lymphocytes
Authors: Turner James E. , Bosch Jos A. , Aldred Sarah
Published: May 2012

Vigorous exercise is associated with oxidative stress, a state that involves modifications to bodily molecules due to release of pro-oxidant species. Assessment of such modifications provides non-specific measures of oxidative stress in human tissues and blood, including circulating lymphocytes. Lymphocytes are a very heterogeneous group of white blood cells, consisting of subtypes that have different functions in immunity. Importantly, exercise drastically changes the lymphocyte composition in blood by increasing the numbers of some subsets, while leaving other cells unaffected. This fact may imply that observed changes in oxidative stress markers are confounded by changes in lymphocyte composition. For example, lymphocyte subsets may differ in exposure to oxidative stress because of subset differences in cell division and the acquisition of cytotoxic effector functions. The aim of the present review is to raise awareness of interpretational issues related to the assessment of oxidative stress in lymphocytes with exercise and to address the relevance of lymphocyte subset phenotyping in these contexts.
Mitochondrial (‘mild’) uncoupling and ROS production: physiologically relevant or not?
Authors: Shabalina Irina G. , Nedergaard Jan
Published: May 2012

During the last decade, the possibility that ‘mild’ uncoupling could be protective against oxidative damage by diminishing ROS (reactive oxygen species) production has attracted much interest. In the present paper, we briefly examine the evidence for this possibility. It is only ROS production from succinate under reverse electron-flow conditions that is sensitive to membrane potential fluctuations, and so only this type of ROS production could be affected; however, the conditions under which succinate-supported ROS production is observed include succinate concentrations that are supraphysiological. Any decrease in membrane potential, even ‘mild uncoupling’, must necessarily lead to large increases in respiration, i.e. it must be markedly thermogenic. Mitochondria within cells are normally ATP-producing and thus already have a diminished membrane potential, and treatment of cells, organs or animals with small amounts of artificial uncoupler does not seem to have beneficial effects that are explainable via reduced ROS production. Although it has been suggested that members of the uncoupling protein family (UCP1, UCP2 and UCP3) may mediate a mild uncoupling, present evidence does not unequivocally support such an effect, e.g. the absence of the truly uncoupling protein UCP1 is not associated with increased oxidative damage. Thus present evidence does not support mild uncoupling as a physiologically relevant alleviator of oxidative damage.
Biochemical contacts and collaborations between China and the U.K. since 1911
Authors: Dodson Guy G.
Published: May 2012

Scientific contact lies at the heart of research and that between China and the U.K. is an important example of how it can come about. In 1911, when the Biochemical Society began, U.K. science was developing fast with profound discoveries in physics (the Rutherford atomic model) and biochemistry (the discovery of vitamins). In China, however, there was great social and political instability and a revolution. Since then, the turbulence of two world wars and a variety of deep global political tensions meant that the contacts between China and U.K. did not reflect the prodigious growth of biochemistry. There was, however, one particular and remarkable contact, that made by Joseph Needham, an outstanding biochemist. He visited China between 1943 and 1946, contacting many Chinese universities that were severely dislocated by war. Showing remarkable diplomatic abilities, Needham managed to arrange delivery of research and teaching equipment. His activities helped the universities to carry out their functions under near-impossible conditions and reminded them that they had friends abroad. Most remarkably, Joseph Needham developed an extraordinary grasp of Chinese culture, science and history and he opened the West to the extent and importance of Chinese science. Formal scientific and intellectual contacts between the scientific academic bodies in China and U.K., notably the Chinese Academy of Science and the Royal Society, resumed after British recognition of the Chinese Communist government in 1950. The delegations included outstanding scientists in biochemistry and related disciplines. Research activities, such as that concerning influenza, were soon established, whereas institutions, such as the Royal Society and the Wellcome Trust, acted a little later to support research. The outcomes have been long-term collaborations in such areas as insulin structure and function. There are now numerous joint activities in biochemistry and biomedicine supported by the MRC (Medical Research Council), BBSRC (Biotechnology and Biological Sciences Research Council), NERC (Natural Environment Research Council), EPSRC (Engineering and Physical Sciences Research Council) and UKRC (UK Research Councils). The present contacts and the associated research are very considerable and growing. It is clear that biochemistry in both countries has much to offer each other, and there is every reason to believe that these contacts will continue to expand in the future.
Insulin research in China and the U.K.
Authors: Zhang Youshang
Published: May 2012

Insulin has been extensively studied since it was discovered by Banting and Best in 1921. Early in 1934, Dorothy Crowfoot and John Desmond Bernal obtained the first X-ray diffraction photograph of an enzyme protein: pepsin. In 1935, they took another photograph of a protein hormone: insulin. The chemical structure of protein was unknown until the amino acid sequence of bovine insulin was solved by Fred Sanger and colleagues in 1955. In 1958, the chemical synthesis of bovine insulin started in China through a nationwide collaboration of three institutions: the Institute of Biochemistry in Shanghai, the Institute of Organic Chemistry in Shanghai and Beijing University. The total synthesis of bovine insulin in crystalline form was accomplished in 1965. The success of the synthesis of the first protein in vitro greatly encouraged young researchers in China. Not long afterwards, the project of structural analysis of insulin crystal was carried out in China through the collaboration of the Institute of Biophysics, the Institute of Physics and Beijing University, and succeeded in 1971. In Dorothy Hodgkin's laboratory in Oxford, X-ray diffraction studies of insulin crystals were resumed after about 30 years, and the structure of rhombohedral insulin crystal was solved in 1969. Through insulin research, the Institute of Biophysics in Beijing and the Institute of Biochemistry in Shanghai established scientific collaboration and personal friendship with Dorothy Hodgkin's laboratory in Oxford, and later Guy Dodson's laboratory in York and Tom Blundell's laboratory in London. In 1975, Dorothy Hodgkin wrote a short note, ‘Chinese work on insulin’ in Nature, anticipating closer scientific exchange between the East and the West. In 1982, a bilateral meeting between the Biochemical Societies in the U.K. and China was held in Oxford. Now, the second bilateral meeting held in Shanghai will further promote the collaboration between our two countries.